Except for pktdvd, the only places setting congested bits are file
systems that allocate their own backing_dev_info structures. And
pktdvd is a deprecated driver that isn't useful in stack setup
either. So remove the dead congested_fn stacking infrastructure.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Song Liu <song@kernel.org>
Acked-by: David Sterba <dsterba@suse.com>
[axboe: fixup unused variables in bcache/request.c]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Merge tag 'for-5.8-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
- regression fix of a leak in global block reserve accounting
- fix a (hard to hit) race of readahead vs releasepage that could lead
to crash
- convert all remaining uses of comment fall through annotations to the
pseudo keyword
- fix crash when mounting a fuzzed image with -o recovery
* tag 'for-5.8-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: reset tree root pointer after error in init_tree_roots
btrfs: fix reclaim_size counter leak after stealing from global reserve
btrfs: fix fatal extent_buffer readahead vs releasepage race
btrfs: convert comments to fallthrough annotations
[BUG]
The following small test script can trigger ASSERT() at unmount time:
mkfs.btrfs -f $dev
mount $dev $mnt
mount -o remount,discard=async $mnt
umount $mnt
The call trace:
assertion failed: atomic_read(&block_group->count) == 1, in fs/btrfs/block-group.c:3431
------------[ cut here ]------------
kernel BUG at fs/btrfs/ctree.h:3204!
invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
CPU: 4 PID: 10389 Comm: umount Tainted: G O 5.8.0-rc3-custom+ #68
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
Call Trace:
btrfs_free_block_groups.cold+0x22/0x55 [btrfs]
close_ctree+0x2cb/0x323 [btrfs]
btrfs_put_super+0x15/0x17 [btrfs]
generic_shutdown_super+0x72/0x110
kill_anon_super+0x18/0x30
btrfs_kill_super+0x17/0x30 [btrfs]
deactivate_locked_super+0x3b/0xa0
deactivate_super+0x40/0x50
cleanup_mnt+0x135/0x190
__cleanup_mnt+0x12/0x20
task_work_run+0x64/0xb0
__prepare_exit_to_usermode+0x1bc/0x1c0
__syscall_return_slowpath+0x47/0x230
do_syscall_64+0x64/0xb0
entry_SYSCALL_64_after_hwframe+0x44/0xa9
The code:
ASSERT(atomic_read(&block_group->count) == 1);
btrfs_put_block_group(block_group);
[CAUSE]
Obviously it's some btrfs_get_block_group() call doesn't get its put
call.
The offending btrfs_get_block_group() happens here:
void btrfs_mark_bg_unused(struct btrfs_block_group *bg)
{
if (list_empty(&bg->bg_list)) {
btrfs_get_block_group(bg);
list_add_tail(&bg->bg_list, &fs_info->unused_bgs);
}
}
So every call sites removing the block group from unused_bgs list should
reduce the ref count of that block group.
However for async discard, it didn't follow the call convention:
void btrfs_discard_punt_unused_bgs_list(struct btrfs_fs_info *fs_info)
{
list_for_each_entry_safe(block_group, next, &fs_info->unused_bgs,
bg_list) {
list_del_init(&block_group->bg_list);
btrfs_discard_queue_work(&fs_info->discard_ctl, block_group);
}
}
And in btrfs_discard_queue_work(), it doesn't call
btrfs_put_block_group() either.
[FIX]
Fix the problem by reducing the reference count when we grab the block
group from unused_bgs list.
Reported-by: Marcos Paulo de Souza <mpdesouza@suse.com>
Fixes: 6e80d4f8c4 ("btrfs: handle empty block_group removal for async discard")
CC: stable@vger.kernel.org # 5.6+
Tested-by: Marcos Paulo de Souza <mpdesouza@suse.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Eric reported an issue where mounting -o recovery with a fuzzed fs
resulted in a kernel panic. This is because we tried to free the tree
node, except it was an error from the read. Fix this by properly
resetting the tree_root->node == NULL in this case. The panic was the
following
BTRFS warning (device loop0): failed to read tree root
BUG: kernel NULL pointer dereference, address: 000000000000001f
RIP: 0010:free_extent_buffer+0xe/0x90 [btrfs]
Call Trace:
free_root_extent_buffers.part.0+0x11/0x30 [btrfs]
free_root_pointers+0x1a/0xa2 [btrfs]
open_ctree+0x1776/0x18a5 [btrfs]
btrfs_mount_root.cold+0x13/0xfa [btrfs]
? selinux_fs_context_parse_param+0x37/0x80
legacy_get_tree+0x27/0x40
vfs_get_tree+0x25/0xb0
fc_mount+0xe/0x30
vfs_kern_mount.part.0+0x71/0x90
btrfs_mount+0x147/0x3e0 [btrfs]
? cred_has_capability+0x7c/0x120
? legacy_get_tree+0x27/0x40
legacy_get_tree+0x27/0x40
vfs_get_tree+0x25/0xb0
do_mount+0x735/0xa40
__x64_sys_mount+0x8e/0xd0
do_syscall_64+0x4d/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Nik says: this is problematic only if we fail on the last iteration of
the loop as this results in init_tree_roots returning err value with
tree_root->node = -ERR. Subsequently the caller does: fail_tree_roots
which calls free_root_pointers on the bogus value.
Reported-by: Eric Sandeen <sandeen@redhat.com>
Fixes: b8522a1e5f ("btrfs: Factor out tree roots initialization during mount")
CC: stable@vger.kernel.org # 5.5+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add details how the pointer gets dereferenced ]
Signed-off-by: David Sterba <dsterba@suse.com>
Under somewhat convoluted conditions, it is possible to attempt to
release an extent_buffer that is under io, which triggers a BUG_ON in
btrfs_release_extent_buffer_pages.
This relies on a few different factors. First, extent_buffer reads done
as readahead for searching use WAIT_NONE, so they free the local extent
buffer reference while the io is outstanding. However, they should still
be protected by TREE_REF. However, if the system is doing signficant
reclaim, and simultaneously heavily accessing the extent_buffers, it is
possible for releasepage to race with two concurrent readahead attempts
in a way that leaves TREE_REF unset when the readahead extent buffer is
released.
Essentially, if two tasks race to allocate a new extent_buffer, but the
winner who attempts the first io is rebuffed by a page being locked
(likely by the reclaim itself) then the loser will still go ahead with
issuing the readahead. The loser's call to find_extent_buffer must also
race with the reclaim task reading the extent_buffer's refcount as 1 in
a way that allows the reclaim to re-clear the TREE_REF checked by
find_extent_buffer.
The following represents an example execution demonstrating the race:
CPU0 CPU1 CPU2
reada_for_search reada_for_search
readahead_tree_block readahead_tree_block
find_create_tree_block find_create_tree_block
alloc_extent_buffer alloc_extent_buffer
find_extent_buffer // not found
allocates eb
lock pages
associate pages to eb
insert eb into radix tree
set TREE_REF, refs == 2
unlock pages
read_extent_buffer_pages // WAIT_NONE
not uptodate (brand new eb)
lock_page
if !trylock_page
goto unlock_exit // not an error
free_extent_buffer
release_extent_buffer
atomic_dec_and_test refs to 1
find_extent_buffer // found
try_release_extent_buffer
take refs_lock
reads refs == 1; no io
atomic_inc_not_zero refs to 2
mark_buffer_accessed
check_buffer_tree_ref
// not STALE, won't take refs_lock
refs == 2; TREE_REF set // no action
read_extent_buffer_pages // WAIT_NONE
clear TREE_REF
release_extent_buffer
atomic_dec_and_test refs to 1
unlock_page
still not uptodate (CPU1 read failed on trylock_page)
locks pages
set io_pages > 0
submit io
return
free_extent_buffer
release_extent_buffer
dec refs to 0
delete from radix tree
btrfs_release_extent_buffer_pages
BUG_ON(io_pages > 0)!!!
We observe this at a very low rate in production and were also able to
reproduce it in a test environment by introducing some spurious delays
and by introducing probabilistic trylock_page failures.
To fix it, we apply check_tree_ref at a point where it could not
possibly be unset by a competing task: after io_pages has been
incremented. All the codepaths that clear TREE_REF check for io, so they
would not be able to clear it after this point until the io is done.
Stack trace, for reference:
[1417839.424739] ------------[ cut here ]------------
[1417839.435328] kernel BUG at fs/btrfs/extent_io.c:4841!
[1417839.447024] invalid opcode: 0000 [#1] SMP
[1417839.502972] RIP: 0010:btrfs_release_extent_buffer_pages+0x20/0x1f0
[1417839.517008] Code: ed e9 ...
[1417839.558895] RSP: 0018:ffffc90020bcf798 EFLAGS: 00010202
[1417839.570816] RAX: 0000000000000002 RBX: ffff888102d6def0 RCX: 0000000000000028
[1417839.586962] RDX: 0000000000000002 RSI: ffff8887f0296482 RDI: ffff888102d6def0
[1417839.603108] RBP: ffff88885664a000 R08: 0000000000000046 R09: 0000000000000238
[1417839.619255] R10: 0000000000000028 R11: ffff88885664af68 R12: 0000000000000000
[1417839.635402] R13: 0000000000000000 R14: ffff88875f573ad0 R15: ffff888797aafd90
[1417839.651549] FS: 00007f5a844fa700(0000) GS:ffff88885f680000(0000) knlGS:0000000000000000
[1417839.669810] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[1417839.682887] CR2: 00007f7884541fe0 CR3: 000000049f609002 CR4: 00000000003606e0
[1417839.699037] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[1417839.715187] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[1417839.731320] Call Trace:
[1417839.737103] release_extent_buffer+0x39/0x90
[1417839.746913] read_block_for_search.isra.38+0x2a3/0x370
[1417839.758645] btrfs_search_slot+0x260/0x9b0
[1417839.768054] btrfs_lookup_file_extent+0x4a/0x70
[1417839.778427] btrfs_get_extent+0x15f/0x830
[1417839.787665] ? submit_extent_page+0xc4/0x1c0
[1417839.797474] ? __do_readpage+0x299/0x7a0
[1417839.806515] __do_readpage+0x33b/0x7a0
[1417839.815171] ? btrfs_releasepage+0x70/0x70
[1417839.824597] extent_readpages+0x28f/0x400
[1417839.833836] read_pages+0x6a/0x1c0
[1417839.841729] ? startup_64+0x2/0x30
[1417839.849624] __do_page_cache_readahead+0x13c/0x1a0
[1417839.860590] filemap_fault+0x6c7/0x990
[1417839.869252] ? xas_load+0x8/0x80
[1417839.876756] ? xas_find+0x150/0x190
[1417839.884839] ? filemap_map_pages+0x295/0x3b0
[1417839.894652] __do_fault+0x32/0x110
[1417839.902540] __handle_mm_fault+0xacd/0x1000
[1417839.912156] handle_mm_fault+0xaa/0x1c0
[1417839.921004] __do_page_fault+0x242/0x4b0
[1417839.930044] ? page_fault+0x8/0x30
[1417839.937933] page_fault+0x1e/0x30
[1417839.945631] RIP: 0033:0x33c4bae
[1417839.952927] Code: Bad RIP value.
[1417839.960411] RSP: 002b:00007f5a844f7350 EFLAGS: 00010206
[1417839.972331] RAX: 000000000000006e RBX: 1614b3ff6a50398a RCX: 0000000000000000
[1417839.988477] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002
[1417840.004626] RBP: 00007f5a844f7420 R08: 000000000000006e R09: 00007f5a94aeccb8
[1417840.020784] R10: 00007f5a844f7350 R11: 0000000000000000 R12: 00007f5a94aecc79
[1417840.036932] R13: 00007f5a94aecc78 R14: 00007f5a94aecc90 R15: 00007f5a94aecc40
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
Convert fall through comments to the pseudo-keyword which is now the
preferred way.
Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The header file linux/uio.h includes crypto/hash.h which pulls in
most of the Crypto API. Since linux/uio.h is used throughout the
kernel this means that every tiny bit of change to the Crypto API
causes the entire kernel to get rebuilt.
This patch fixes this by moving it into lib/iov_iter.c instead
where it is actually used.
This patch also fixes the ifdef to use CRYPTO_HASH instead of just
CRYPTO which does not guarantee the existence of ahash.
Unfortunately a number of drivers were relying on linux/uio.h to
provide access to linux/slab.h. This patch adds inclusions of
linux/slab.h as detected by build failures.
Also skbuff.h was relying on this to provide a declaration for
ahash_request. This patch adds a forward declaration instead.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Merge tag 'for-5.8-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
"A number of fixes, located in two areas, one performance fix and one
fixup for better integration with another patchset.
- bug fixes in nowait aio:
- fix snapshot creation hang after nowait-aio was used
- fix failure to write to prealloc extent past EOF
- don't block when extent range is locked
- block group fixes:
- relocation failure when scrub runs in parallel
- refcount fix when removing fails
- fix race between removal and creation
- space accounting fixes
- reinstante fast path check for log tree at unlink time, fixes
performance drop up to 30% in REAIM
- kzfree/kfree fixup to ease treewide patchset renaming kzfree"
* tag 'for-5.8-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: use kfree() in btrfs_ioctl_get_subvol_info()
btrfs: fix RWF_NOWAIT writes blocking on extent locks and waiting for IO
btrfs: fix RWF_NOWAIT write not failling when we need to cow
btrfs: fix failure of RWF_NOWAIT write into prealloc extent beyond eof
btrfs: fix hang on snapshot creation after RWF_NOWAIT write
btrfs: check if a log root exists before locking the log_mutex on unlink
btrfs: fix bytes_may_use underflow when running balance and scrub in parallel
btrfs: fix data block group relocation failure due to concurrent scrub
btrfs: fix race between block group removal and block group creation
btrfs: fix a block group ref counter leak after failure to remove block group
In btrfs_ioctl_get_subvol_info(), there is a classic case where kzalloc()
was incorrectly paired with kzfree(). According to David Sterba, there
isn't any sensitive information in the subvol_info that needs to be
cleared before freeing. So kzfree() isn't really needed, use kfree()
instead.
Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
A RWF_NOWAIT write is not supposed to wait on filesystem locks that can be
held for a long time or for ongoing IO to complete.
However when calling check_can_nocow(), if the inode has prealloc extents
or has the NOCOW flag set, we can block on extent (file range) locks
through the call to btrfs_lock_and_flush_ordered_range(). Such lock can
take a significant amount of time to be available. For example, a fiemap
task may be running, and iterating through the entire file range checking
all extents and doing backref walking to determine if they are shared,
or a readpage operation may be in progress.
Also at btrfs_lock_and_flush_ordered_range(), called by check_can_nocow(),
after locking the file range we wait for any existing ordered extent that
is in progress to complete. Another operation that can take a significant
amount of time and defeat the purpose of RWF_NOWAIT.
So fix this by trying to lock the file range and if it's currently locked
return -EAGAIN to user space. If we are able to lock the file range without
waiting and there is an ordered extent in the range, return -EAGAIN as
well, instead of waiting for it to complete. Finally, don't bother trying
to lock the snapshot lock of the root when attempting a RWF_NOWAIT write,
as that is only important for buffered writes.
Fixes: edf064e7c6 ("btrfs: nowait aio support")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
If we attempt to do a RWF_NOWAIT write against a file range for which we
can only do NOCOW for a part of it, due to the existence of holes or
shared extents for example, we proceed with the write as if it were
possible to NOCOW the whole range.
Example:
$ mkfs.btrfs -f /dev/sdb
$ mount /dev/sdb /mnt
$ touch /mnt/sdj/bar
$ chattr +C /mnt/sdj/bar
$ xfs_io -d -c "pwrite -S 0xab -b 256K 0 256K" /mnt/bar
wrote 262144/262144 bytes at offset 0
256 KiB, 1 ops; 0.0003 sec (694.444 MiB/sec and 2777.7778 ops/sec)
$ xfs_io -c "fpunch 64K 64K" /mnt/bar
$ sync
$ xfs_io -d -c "pwrite -N -V 1 -b 128K -S 0xfe 0 128K" /mnt/bar
wrote 131072/131072 bytes at offset 0
128 KiB, 1 ops; 0.0007 sec (160.051 MiB/sec and 1280.4097 ops/sec)
This last write should fail with -EAGAIN since the file range from 64K to
128K is a hole. On xfs it fails, as expected, but on ext4 it currently
succeeds because apparently it is expensive to check if there are extents
allocated for the whole range, but I'll check with the ext4 people.
Fix the issue by checking if check_can_nocow() returns a number of
NOCOW'able bytes smaller then the requested number of bytes, and if it
does return -EAGAIN.
Fixes: edf064e7c6 ("btrfs: nowait aio support")
CC: stable@vger.kernel.org # 4.14+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
If we attempt to write to prealloc extent located after eof using a
RWF_NOWAIT write, we always fail with -EAGAIN.
We do actually check if we have an allocated extent for the write at
the start of btrfs_file_write_iter() through a call to check_can_nocow(),
but later when we go into the actual direct IO write path we simply
return -EAGAIN if the write starts at or beyond EOF.
Trivial to reproduce:
$ mkfs.btrfs -f /dev/sdb
$ mount /dev/sdb /mnt
$ touch /mnt/foo
$ chattr +C /mnt/foo
$ xfs_io -d -c "pwrite -S 0xab 0 64K" /mnt/foo
wrote 65536/65536 bytes at offset 0
64 KiB, 16 ops; 0.0004 sec (135.575 MiB/sec and 34707.1584 ops/sec)
$ xfs_io -c "falloc -k 64K 1M" /mnt/foo
$ xfs_io -d -c "pwrite -N -V 1 -S 0xfe -b 64K 64K 64K" /mnt/foo
pwrite: Resource temporarily unavailable
On xfs and ext4 the write succeeds, as expected.
Fix this by removing the wrong check at btrfs_direct_IO().
Fixes: edf064e7c6 ("btrfs: nowait aio support")
CC: stable@vger.kernel.org # 4.14+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
If we do a successful RWF_NOWAIT write we end up locking the snapshot lock
of the inode, through a call to check_can_nocow(), but we never unlock it.
This means the next attempt to create a snapshot on the subvolume will
hang forever.
Trivial reproducer:
$ mkfs.btrfs -f /dev/sdb
$ mount /dev/sdb /mnt
$ touch /mnt/foobar
$ chattr +C /mnt/foobar
$ xfs_io -d -c "pwrite -S 0xab 0 64K" /mnt/foobar
$ xfs_io -d -c "pwrite -N -V 1 -S 0xfe 0 64K" /mnt/foobar
$ btrfs subvolume snapshot -r /mnt /mnt/snap
--> hangs
Fix this by unlocking the snapshot lock if check_can_nocow() returned
success.
Fixes: edf064e7c6 ("btrfs: nowait aio support")
CC: stable@vger.kernel.org # 4.14+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This brings back an optimization that commit e678934cbe ("btrfs:
Remove unnecessary check from join_running_log_trans") removed, but in
a different form. So it's almost equivalent to a revert.
That commit removed an optimization where we avoid locking a root's
log_mutex when there is no log tree created in the current transaction.
The affected code path is triggered through unlink operations.
That commit was based on the assumption that the optimization was not
necessary because we used to have the following checks when the patch
was authored:
int btrfs_del_dir_entries_in_log(...)
{
(...)
if (dir->logged_trans < trans->transid)
return 0;
ret = join_running_log_trans(root);
(...)
}
int btrfs_del_inode_ref_in_log(...)
{
(...)
if (inode->logged_trans < trans->transid)
return 0;
ret = join_running_log_trans(root);
(...)
}
However before that patch was merged, another patch was merged first which
replaced those checks because they were buggy.
That other patch corresponds to commit 803f0f64d1 ("Btrfs: fix fsync
not persisting dentry deletions due to inode evictions"). The assumption
that if the logged_trans field of an inode had a smaller value then the
current transaction's generation (transid) meant that the inode was not
logged in the current transaction was only correct if the inode was not
evicted and reloaded in the current transaction. So the corresponding bug
fix changed those checks and replaced them with the following helper
function:
static bool inode_logged(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode)
{
if (inode->logged_trans == trans->transid)
return true;
if (inode->last_trans == trans->transid &&
test_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags) &&
!test_bit(BTRFS_FS_LOG_RECOVERING, &trans->fs_info->flags))
return true;
return false;
}
So if we have a subvolume without a log tree in the current transaction
(because we had no fsyncs), every time we unlink an inode we can end up
trying to lock the log_mutex of the root through join_running_log_trans()
twice, once for the inode being unlinked (by btrfs_del_inode_ref_in_log())
and once for the parent directory (with btrfs_del_dir_entries_in_log()).
This means if we have several unlink operations happening in parallel for
inodes in the same subvolume, and the those inodes and/or their parent
inode were changed in the current transaction, we end up having a lot of
contention on the log_mutex.
The test robots from intel reported a -30.7% performance regression for
a REAIM test after commit e678934cbe ("btrfs: Remove unnecessary check
from join_running_log_trans").
So just bring back the optimization to join_running_log_trans() where we
check first if a log root exists before trying to lock the log_mutex. This
is done by checking for a bit that is set on the root when a log tree is
created and removed when a log tree is freed (at transaction commit time).
Commit e678934cbe ("btrfs: Remove unnecessary check from
join_running_log_trans") was merged in the 5.4 merge window while commit
803f0f64d1 ("Btrfs: fix fsync not persisting dentry deletions due to
inode evictions") was merged in the 5.3 merge window. But the first
commit was actually authored before the second commit (May 23 2019 vs
June 19 2019).
Reported-by: kernel test robot <rong.a.chen@intel.com>
Link: https://lore.kernel.org/lkml/20200611090233.GL12456@shao2-debian/
Fixes: e678934cbe ("btrfs: Remove unnecessary check from join_running_log_trans")
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When balance and scrub are running in parallel it is possible to end up
with an underflow of the bytes_may_use counter of the data space_info
object, which triggers a warning like the following:
[134243.793196] BTRFS info (device sdc): relocating block group 1104150528 flags data
[134243.806891] ------------[ cut here ]------------
[134243.807561] WARNING: CPU: 1 PID: 26884 at fs/btrfs/space-info.h:125 btrfs_add_reserved_bytes+0x1da/0x280 [btrfs]
[134243.808819] Modules linked in: btrfs blake2b_generic xor (...)
[134243.815779] CPU: 1 PID: 26884 Comm: kworker/u8:8 Tainted: G W 5.6.0-rc7-btrfs-next-58 #5
[134243.816944] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
[134243.818389] Workqueue: writeback wb_workfn (flush-btrfs-108483)
[134243.819186] RIP: 0010:btrfs_add_reserved_bytes+0x1da/0x280 [btrfs]
[134243.819963] Code: 0b f2 85 (...)
[134243.822271] RSP: 0018:ffffa4160aae7510 EFLAGS: 00010287
[134243.822929] RAX: 000000000000c000 RBX: ffff96159a8c1000 RCX: 0000000000000000
[134243.823816] RDX: 0000000000008000 RSI: 0000000000000000 RDI: ffff96158067a810
[134243.824742] RBP: ffff96158067a800 R08: 0000000000000001 R09: 0000000000000000
[134243.825636] R10: ffff961501432a40 R11: 0000000000000000 R12: 000000000000c000
[134243.826532] R13: 0000000000000001 R14: ffffffffffff4000 R15: ffff96158067a810
[134243.827432] FS: 0000000000000000(0000) GS:ffff9615baa00000(0000) knlGS:0000000000000000
[134243.828451] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[134243.829184] CR2: 000055bd7e414000 CR3: 00000001077be004 CR4: 00000000003606e0
[134243.830083] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[134243.830975] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[134243.831867] Call Trace:
[134243.832211] find_free_extent+0x4a0/0x16c0 [btrfs]
[134243.832846] btrfs_reserve_extent+0x91/0x180 [btrfs]
[134243.833487] cow_file_range+0x12d/0x490 [btrfs]
[134243.834080] fallback_to_cow+0x82/0x1b0 [btrfs]
[134243.834689] ? release_extent_buffer+0x121/0x170 [btrfs]
[134243.835370] run_delalloc_nocow+0x33f/0xa30 [btrfs]
[134243.836032] btrfs_run_delalloc_range+0x1ea/0x6d0 [btrfs]
[134243.836725] ? find_lock_delalloc_range+0x221/0x250 [btrfs]
[134243.837450] writepage_delalloc+0xe8/0x150 [btrfs]
[134243.838059] __extent_writepage+0xe8/0x4c0 [btrfs]
[134243.838674] extent_write_cache_pages+0x237/0x530 [btrfs]
[134243.839364] extent_writepages+0x44/0xa0 [btrfs]
[134243.839946] do_writepages+0x23/0x80
[134243.840401] __writeback_single_inode+0x59/0x700
[134243.841006] writeback_sb_inodes+0x267/0x5f0
[134243.841548] __writeback_inodes_wb+0x87/0xe0
[134243.842091] wb_writeback+0x382/0x590
[134243.842574] ? wb_workfn+0x4a2/0x6c0
[134243.843030] wb_workfn+0x4a2/0x6c0
[134243.843468] process_one_work+0x26d/0x6a0
[134243.843978] worker_thread+0x4f/0x3e0
[134243.844452] ? process_one_work+0x6a0/0x6a0
[134243.844981] kthread+0x103/0x140
[134243.845400] ? kthread_create_worker_on_cpu+0x70/0x70
[134243.846030] ret_from_fork+0x3a/0x50
[134243.846494] irq event stamp: 0
[134243.846892] hardirqs last enabled at (0): [<0000000000000000>] 0x0
[134243.847682] hardirqs last disabled at (0): [<ffffffffb2abdedf>] copy_process+0x74f/0x2020
[134243.848687] softirqs last enabled at (0): [<ffffffffb2abdedf>] copy_process+0x74f/0x2020
[134243.849913] softirqs last disabled at (0): [<0000000000000000>] 0x0
[134243.850698] ---[ end trace bd7c03622e0b0a96 ]---
[134243.851335] ------------[ cut here ]------------
When relocating a data block group, for each extent allocated in the
block group we preallocate another extent with the same size for the
data relocation inode (we do it at prealloc_file_extent_cluster()).
We reserve space by calling btrfs_check_data_free_space(), which ends
up incrementing the data space_info's bytes_may_use counter, and
then call btrfs_prealloc_file_range() to allocate the extent, which
always decrements the bytes_may_use counter by the same amount.
The expectation is that writeback of the data relocation inode always
follows a NOCOW path, by writing into the preallocated extents. However,
when starting writeback we might end up falling back into the COW path,
because the block group that contains the preallocated extent was turned
into RO mode by a scrub running in parallel. The COW path then calls the
extent allocator which ends up calling btrfs_add_reserved_bytes(), and
this function decrements the bytes_may_use counter of the data space_info
object by an amount corresponding to the size of the allocated extent,
despite we haven't previously incremented it. When the counter currently
has a value smaller then the allocated extent we reset the counter to 0
and emit a warning, otherwise we just decrement it and slowly mess up
with this counter which is crucial for space reservation, the end result
can be granting reserved space to tasks when there isn't really enough
free space, and having the tasks fail later in critical places where
error handling consists of a transaction abort or hitting a BUG_ON().
Fix this by making sure that if we fallback to the COW path for a data
relocation inode, we increment the bytes_may_use counter of the data
space_info object. The COW path will then decrement it at
btrfs_add_reserved_bytes() on success or through its error handling part
by a call to extent_clear_unlock_delalloc() (which ends up calling
btrfs_clear_delalloc_extent() that does the decrement operation) in case
of an error.
Test case btrfs/061 from fstests could sporadically trigger this.
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When running relocation of a data block group while scrub is running in
parallel, it is possible that the relocation will fail and abort the
current transaction with an -EINVAL error:
[134243.988595] BTRFS info (device sdc): found 14 extents, stage: move data extents
[134243.999871] ------------[ cut here ]------------
[134244.000741] BTRFS: Transaction aborted (error -22)
[134244.001692] WARNING: CPU: 0 PID: 26954 at fs/btrfs/ctree.c:1071 __btrfs_cow_block+0x6a7/0x790 [btrfs]
[134244.003380] Modules linked in: btrfs blake2b_generic xor raid6_pq (...)
[134244.012577] CPU: 0 PID: 26954 Comm: btrfs Tainted: G W 5.6.0-rc7-btrfs-next-58 #5
[134244.014162] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
[134244.016184] RIP: 0010:__btrfs_cow_block+0x6a7/0x790 [btrfs]
[134244.017151] Code: 48 c7 c7 (...)
[134244.020549] RSP: 0018:ffffa41607863888 EFLAGS: 00010286
[134244.021515] RAX: 0000000000000000 RBX: ffff9614bdfe09c8 RCX: 0000000000000000
[134244.022822] RDX: 0000000000000001 RSI: ffffffffb3d63980 RDI: 0000000000000001
[134244.024124] RBP: ffff961589e8c000 R08: 0000000000000000 R09: 0000000000000001
[134244.025424] R10: ffffffffc0ae5955 R11: 0000000000000000 R12: ffff9614bd530d08
[134244.026725] R13: ffff9614ced41b88 R14: ffff9614bdfe2a48 R15: 0000000000000000
[134244.028024] FS: 00007f29b63c08c0(0000) GS:ffff9615ba600000(0000) knlGS:0000000000000000
[134244.029491] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[134244.030560] CR2: 00007f4eb339b000 CR3: 0000000130d6e006 CR4: 00000000003606f0
[134244.031997] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[134244.033153] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[134244.034484] Call Trace:
[134244.034984] btrfs_cow_block+0x12b/0x2b0 [btrfs]
[134244.035859] do_relocation+0x30b/0x790 [btrfs]
[134244.036681] ? do_raw_spin_unlock+0x49/0xc0
[134244.037460] ? _raw_spin_unlock+0x29/0x40
[134244.038235] relocate_tree_blocks+0x37b/0x730 [btrfs]
[134244.039245] relocate_block_group+0x388/0x770 [btrfs]
[134244.040228] btrfs_relocate_block_group+0x161/0x2e0 [btrfs]
[134244.041323] btrfs_relocate_chunk+0x36/0x110 [btrfs]
[134244.041345] btrfs_balance+0xc06/0x1860 [btrfs]
[134244.043382] ? btrfs_ioctl_balance+0x27c/0x310 [btrfs]
[134244.045586] btrfs_ioctl_balance+0x1ed/0x310 [btrfs]
[134244.045611] btrfs_ioctl+0x1880/0x3760 [btrfs]
[134244.049043] ? do_raw_spin_unlock+0x49/0xc0
[134244.049838] ? _raw_spin_unlock+0x29/0x40
[134244.050587] ? __handle_mm_fault+0x11b3/0x14b0
[134244.051417] ? ksys_ioctl+0x92/0xb0
[134244.052070] ksys_ioctl+0x92/0xb0
[134244.052701] ? trace_hardirqs_off_thunk+0x1a/0x1c
[134244.053511] __x64_sys_ioctl+0x16/0x20
[134244.054206] do_syscall_64+0x5c/0x280
[134244.054891] entry_SYSCALL_64_after_hwframe+0x49/0xbe
[134244.055819] RIP: 0033:0x7f29b51c9dd7
[134244.056491] Code: 00 00 00 (...)
[134244.059767] RSP: 002b:00007ffcccc1dd08 EFLAGS: 00000202 ORIG_RAX: 0000000000000010
[134244.061168] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f29b51c9dd7
[134244.062474] RDX: 00007ffcccc1dda0 RSI: 00000000c4009420 RDI: 0000000000000003
[134244.063771] RBP: 0000000000000003 R08: 00005565cea4b000 R09: 0000000000000000
[134244.065032] R10: 0000000000000541 R11: 0000000000000202 R12: 00007ffcccc2060a
[134244.066327] R13: 00007ffcccc1dda0 R14: 0000000000000002 R15: 00007ffcccc1dec0
[134244.067626] irq event stamp: 0
[134244.068202] hardirqs last enabled at (0): [<0000000000000000>] 0x0
[134244.069351] hardirqs last disabled at (0): [<ffffffffb2abdedf>] copy_process+0x74f/0x2020
[134244.070909] softirqs last enabled at (0): [<ffffffffb2abdedf>] copy_process+0x74f/0x2020
[134244.072392] softirqs last disabled at (0): [<0000000000000000>] 0x0
[134244.073432] ---[ end trace bd7c03622e0b0a99 ]---
The -EINVAL error comes from the following chain of function calls:
__btrfs_cow_block() <-- aborts the transaction
btrfs_reloc_cow_block()
replace_file_extents()
get_new_location() <-- returns -EINVAL
When relocating a data block group, for each allocated extent of the block
group, we preallocate another extent (at prealloc_file_extent_cluster()),
associated with the data relocation inode, and then dirty all its pages.
These preallocated extents have, and must have, the same size that extents
from the data block group being relocated have.
Later before we start the relocation stage that updates pointers (bytenr
field of file extent items) to point to the the new extents, we trigger
writeback for the data relocation inode. The expectation is that writeback
will write the pages to the previously preallocated extents, that it
follows the NOCOW path. That is generally the case, however, if a scrub
is running it may have turned the block group that contains those extents
into RO mode, in which case writeback falls back to the COW path.
However in the COW path instead of allocating exactly one extent with the
expected size, the allocator may end up allocating several smaller extents
due to free space fragmentation - because we tell it at cow_file_range()
that the minimum allocation size can match the filesystem's sector size.
This later breaks the relocation's expectation that an extent associated
to a file extent item in the data relocation inode has the same size as
the respective extent pointed by a file extent item in another tree - in
this case the extent to which the relocation inode poins to is smaller,
causing relocation.c:get_new_location() to return -EINVAL.
For example, if we are relocating a data block group X that has a logical
address of X and the block group has an extent allocated at the logical
address X + 128KiB with a size of 64KiB:
1) At prealloc_file_extent_cluster() we allocate an extent for the data
relocation inode with a size of 64KiB and associate it to the file
offset 128KiB (X + 128KiB - X) of the data relocation inode. This
preallocated extent was allocated at block group Z;
2) A scrub running in parallel turns block group Z into RO mode and
starts scrubing its extents;
3) Relocation triggers writeback for the data relocation inode;
4) When running delalloc (btrfs_run_delalloc_range()), we try first the
NOCOW path because the data relocation inode has BTRFS_INODE_PREALLOC
set in its flags. However, because block group Z is in RO mode, the
NOCOW path (run_delalloc_nocow()) falls back into the COW path, by
calling cow_file_range();
5) At cow_file_range(), in the first iteration of the while loop we call
btrfs_reserve_extent() to allocate a 64KiB extent and pass it a minimum
allocation size of 4KiB (fs_info->sectorsize). Due to free space
fragmentation, btrfs_reserve_extent() ends up allocating two extents
of 32KiB each, each one on a different iteration of that while loop;
6) Writeback of the data relocation inode completes;
7) Relocation proceeds and ends up at relocation.c:replace_file_extents(),
with a leaf which has a file extent item that points to the data extent
from block group X, that has a logical address (bytenr) of X + 128KiB
and a size of 64KiB. Then it calls get_new_location(), which does a
lookup in the data relocation tree for a file extent item starting at
offset 128KiB (X + 128KiB - X) and belonging to the data relocation
inode. It finds a corresponding file extent item, however that item
points to an extent that has a size of 32KiB, which doesn't match the
expected size of 64KiB, resuling in -EINVAL being returned from this
function and propagated up to __btrfs_cow_block(), which aborts the
current transaction.
To fix this make sure that at cow_file_range() when we call the allocator
we pass it a minimum allocation size corresponding the desired extent size
if the inode belongs to the data relocation tree, otherwise pass it the
filesystem's sector size as the minimum allocation size.
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There is a race between block group removal and block group creation
when the removal is completed by a task running fitrim or scrub. When
this happens we end up failing the block group creation with an error
-EEXIST since we attempt to insert a duplicate block group item key
in the extent tree. That results in a transaction abort.
The race happens like this:
1) Task A is doing a fitrim, and at btrfs_trim_block_group() it freezes
block group X with btrfs_freeze_block_group() (until very recently
that was named btrfs_get_block_group_trimming());
2) Task B starts removing block group X, either because it's now unused
or due to relocation for example. So at btrfs_remove_block_group(),
while holding the chunk mutex and the block group's lock, it sets
the 'removed' flag of the block group and it sets the local variable
'remove_em' to false, because the block group is currently frozen
(its 'frozen' counter is > 0, until very recently this counter was
named 'trimming');
3) Task B unlocks the block group and the chunk mutex;
4) Task A is done trimming the block group and unfreezes the block group
by calling btrfs_unfreeze_block_group() (until very recently this was
named btrfs_put_block_group_trimming()). In this function we lock the
block group and set the local variable 'cleanup' to true because we
were able to decrement the block group's 'frozen' counter down to 0 and
the flag 'removed' is set in the block group.
Since 'cleanup' is set to true, it locks the chunk mutex and removes
the extent mapping representing the block group from the mapping tree;
5) Task C allocates a new block group Y and it picks up the logical address
that block group X had as the logical address for Y, because X was the
block group with the highest logical address and now the second block
group with the highest logical address, the last in the fs mapping tree,
ends at an offset corresponding to block group X's logical address (this
logical address selection is done at volumes.c:find_next_chunk()).
At this point the new block group Y does not have yet its item added
to the extent tree (nor the corresponding device extent items and
chunk item in the device and chunk trees). The new group Y is added to
the list of pending block groups in the transaction handle;
6) Before task B proceeds to removing the block group item for block
group X from the extent tree, which has a key matching:
(X logical offset, BTRFS_BLOCK_GROUP_ITEM_KEY, length)
task C while ending its transaction handle calls
btrfs_create_pending_block_groups(), which finds block group Y and
tries to insert the block group item for Y into the exten tree, which
fails with -EEXIST since logical offset is the same that X had and
task B hasn't yet deleted the key from the extent tree.
This failure results in a transaction abort, producing a stack like
the following:
------------[ cut here ]------------
BTRFS: Transaction aborted (error -17)
WARNING: CPU: 2 PID: 19736 at fs/btrfs/block-group.c:2074 btrfs_create_pending_block_groups+0x1eb/0x260 [btrfs]
Modules linked in: btrfs blake2b_generic xor raid6_pq (...)
CPU: 2 PID: 19736 Comm: fsstress Tainted: G W 5.6.0-rc7-btrfs-next-58 #5
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
RIP: 0010:btrfs_create_pending_block_groups+0x1eb/0x260 [btrfs]
Code: ff ff ff 48 8b 55 50 f0 48 (...)
RSP: 0018:ffffa4160a1c7d58 EFLAGS: 00010286
RAX: 0000000000000000 RBX: ffff961581909d98 RCX: 0000000000000000
RDX: 0000000000000001 RSI: ffffffffb3d63990 RDI: 0000000000000001
RBP: ffff9614f3356a58 R08: 0000000000000000 R09: 0000000000000001
R10: ffff9615b65b0040 R11: 0000000000000000 R12: ffff961581909c10
R13: ffff9615b0c32000 R14: ffff9614f3356ab0 R15: ffff9614be779000
FS: 00007f2ce2841e80(0000) GS:ffff9615bae00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555f18780000 CR3: 0000000131d34005 CR4: 00000000003606e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
btrfs_start_dirty_block_groups+0x398/0x4e0 [btrfs]
btrfs_commit_transaction+0xd0/0xc50 [btrfs]
? btrfs_attach_transaction_barrier+0x1e/0x50 [btrfs]
? __ia32_sys_fdatasync+0x20/0x20
iterate_supers+0xdb/0x180
ksys_sync+0x60/0xb0
__ia32_sys_sync+0xa/0x10
do_syscall_64+0x5c/0x280
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f2ce1d4d5b7
Code: 83 c4 08 48 3d 01 (...)
RSP: 002b:00007ffd8b558c58 EFLAGS: 00000202 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 000000000000002c RCX: 00007f2ce1d4d5b7
RDX: 00000000ffffffff RSI: 00000000186ba07b RDI: 000000000000002c
RBP: 0000555f17b9e520 R08: 0000000000000012 R09: 000000000000ce00
R10: 0000000000000078 R11: 0000000000000202 R12: 0000000000000032
R13: 0000000051eb851f R14: 00007ffd8b558cd0 R15: 0000555f1798ec20
irq event stamp: 0
hardirqs last enabled at (0): [<0000000000000000>] 0x0
hardirqs last disabled at (0): [<ffffffffb2abdedf>] copy_process+0x74f/0x2020
softirqs last enabled at (0): [<ffffffffb2abdedf>] copy_process+0x74f/0x2020
softirqs last disabled at (0): [<0000000000000000>] 0x0
---[ end trace bd7c03622e0b0a9c ]---
Fix this simply by making btrfs_remove_block_group() remove the block
group's item from the extent tree before it flags the block group as
removed. Also make the free space deletion from the free space tree
before flagging the block group as removed, to avoid a similar race
with adding and removing free space entries for the free space tree.
Fixes: 04216820fe ("Btrfs: fix race between fs trimming and block group remove/allocation")
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When removing a block group, if we fail to delete the block group's item
from the extent tree, we jump to the 'out' label and end up decrementing
the block group's reference count once only (by 1), resulting in a counter
leak because the block group at that point was already removed from the
block group cache rbtree - so we have to decrement the reference count
twice, once for the rbtree and once for our lookup at the start of the
function.
There is a second bug where if removing the free space tree entries (the
call to remove_block_group_free_space()) fails we end up jumping to the
'out_put_group' label but end up decrementing the reference count only
once, when we should have done it twice, since we have already removed
the block group from the block group cache rbtree. This happens because
the reference count decrement for the rbtree reference happens after
attempting to remove the free space tree entries, which is far away from
the place where we remove the block group from the rbtree.
To make things less error prone, decrement the reference count for the
rbtree immediately after removing the block group from it. This also
eleminates the need for two different exit labels on error, renaming
'out_put_label' to just 'out' and removing the old 'out'.
Fixes: f6033c5e33 ("btrfs: fix block group leak when removing fails")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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Merge tag 'for-5.8-part2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs updates from David Sterba:
"This reverts the direct io port to iomap infrastructure of btrfs
merged in the first pull request. We found problems in invalidate page
that don't seem to be fixable as regressions or without changing iomap
code that would not affect other filesystems.
There are four reverts in total, but three of them are followup
cleanups needed to revert a43a67a2d7 cleanly. The result is the
buffer head based implementation of direct io.
Reverts are not great, but under current circumstances I don't see
better options"
* tag 'for-5.8-part2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
Revert "btrfs: switch to iomap_dio_rw() for dio"
Revert "fs: remove dio_end_io()"
Revert "btrfs: remove BTRFS_INODE_READDIO_NEED_LOCK"
Revert "btrfs: split btrfs_direct_IO to read and write part"
This reverts commit a43a67a2d7.
This patch reverts the main part of switching direct io implementation
to iomap infrastructure. There's a problem in invalidate page that
couldn't be solved as regression in this development cycle.
The problem occurs when buffered and direct io are mixed, and the ranges
overlap. Although this is not recommended, filesystems implement
measures or fallbacks to make it somehow work. In this case, fallback to
buffered IO would be an option for btrfs (this already happens when
direct io is done on compressed data), but the change would be needed in
the iomap code, bringing new semantics to other filesystems.
Another problem arises when again the buffered and direct ios are mixed,
invalidation fails, then -EIO is set on the mapping and fsync will fail,
though there's no real error.
There have been discussions how to fix that, but revert seems to be the
least intrusive option.
Link: https://lore.kernel.org/linux-btrfs/20200528192103.xm45qoxqmkw7i5yl@fiona/
Signed-off-by: David Sterba <dsterba@suse.com>
This reverts commit 5f008163a5.
The patch is a simplification after direct IO port to iomap
infrastructure, which gets reverted.
Signed-off-by: David Sterba <dsterba@suse.com>
This reverts commit d8f3e73587.
The patch is a cleanup of direct IO port to iomap infrastructure,
which gets reverted.
Signed-off-by: David Sterba <dsterba@suse.com>
* Fix performance problems found in dioread_nolock now that it is the
default, caused by transaction leaks.
* Clean up fiemap handling in ext4
* Clean up and refactor multiple block allocator (mballoc) code
* Fix a problem with mballoc with a smaller file systems running out
of blocks because they couldn't properly use blocks that had been
reserved by inode preallocation.
* Fixed a race in ext4_sync_parent() versus rename()
* Simplify the error handling in the extent manipulation code
* Make sure all metadata I/O errors are felected to ext4_ext_dirty()'s and
ext4_make_inode_dirty()'s callers.
* Avoid passing an error pointer to brelse in ext4_xattr_set()
* Fix race which could result to freeing an inode on the dirty last
in data=journal mode.
* Fix refcount handling if ext4_iget() fails
* Fix a crash in generic/019 caused by a corrupted extent node
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Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Pull ext4 updates from Ted Ts'o:
"A lot of bug fixes and cleanups for ext4, including:
- Fix performance problems found in dioread_nolock now that it is the
default, caused by transaction leaks.
- Clean up fiemap handling in ext4
- Clean up and refactor multiple block allocator (mballoc) code
- Fix a problem with mballoc with a smaller file systems running out
of blocks because they couldn't properly use blocks that had been
reserved by inode preallocation.
- Fixed a race in ext4_sync_parent() versus rename()
- Simplify the error handling in the extent manipulation code
- Make sure all metadata I/O errors are felected to
ext4_ext_dirty()'s and ext4_make_inode_dirty()'s callers.
- Avoid passing an error pointer to brelse in ext4_xattr_set()
- Fix race which could result to freeing an inode on the dirty last
in data=journal mode.
- Fix refcount handling if ext4_iget() fails
- Fix a crash in generic/019 caused by a corrupted extent node"
* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (58 commits)
ext4: avoid unnecessary transaction starts during writeback
ext4: don't block for O_DIRECT if IOCB_NOWAIT is set
ext4: remove the access_ok() check in ext4_ioctl_get_es_cache
fs: remove the access_ok() check in ioctl_fiemap
fs: handle FIEMAP_FLAG_SYNC in fiemap_prep
fs: move fiemap range validation into the file systems instances
iomap: fix the iomap_fiemap prototype
fs: move the fiemap definitions out of fs.h
fs: mark __generic_block_fiemap static
ext4: remove the call to fiemap_check_flags in ext4_fiemap
ext4: split _ext4_fiemap
ext4: fix fiemap size checks for bitmap files
ext4: fix EXT4_MAX_LOGICAL_BLOCK macro
add comment for ext4_dir_entry_2 file_type member
jbd2: avoid leaking transaction credits when unreserving handle
ext4: drop ext4_journal_free_reserved()
ext4: mballoc: use lock for checking free blocks while retrying
ext4: mballoc: refactor ext4_mb_good_group()
ext4: mballoc: introduce pcpu seqcnt for freeing PA to improve ENOSPC handling
ext4: mballoc: refactor ext4_mb_discard_preallocations()
...
By moving FIEMAP_FLAG_SYNC handling to fiemap_prep we ensure it is
handled once instead of duplicated, but can still be done under fs locks,
like xfs/iomap intended with its duplicate handling. Also make sure the
error value of filemap_write_and_wait is propagated to user space.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Link: https://lore.kernel.org/r/20200523073016.2944131-8-hch@lst.de
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Replace fiemap_check_flags with a fiemap_prep helper that also takes the
inode and mapped range, and performs the sanity check and truncation
previously done in fiemap_check_range. This way the validation is inside
the file system itself and thus properly works for the stacked overlayfs
case as well.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Link: https://lore.kernel.org/r/20200523073016.2944131-7-hch@lst.de
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
No need to pull the fiemap definitions into almost every file in the
kernel build.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Link: https://lore.kernel.org/r/20200523073016.2944131-5-hch@lst.de
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
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Merge tag 'for-5.8-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs updates from David Sterba:
"Highlights:
- speedup dead root detection during orphan cleanup, eg. when there
are many deleted subvolumes waiting to be cleaned, the trees are
now looked up in radix tree instead of a O(N^2) search
- snapshot creation with inherited qgroup will mark the qgroup
inconsistent, requires a rescan
- send will emit file capabilities after chown, this produces a
stream that does not need postprocessing to set the capabilities
again
- direct io ported to iomap infrastructure, cleaned up and simplified
code, notably removing last use of struct buffer_head in btrfs code
Core changes:
- factor out backreference iteration, to be used by ordinary
backreferences and relocation code
- improved global block reserve utilization
* better logic to serialize requests
* increased maximum available for unlink
* improved handling on large pages (64K)
- direct io cleanups and fixes
* simplify layering, where cloned bios were unnecessarily created
for some cases
* error handling fixes (submit, endio)
* remove repair worker thread, used to avoid deadlocks during
repair
- refactored block group reading code, preparatory work for new type
of block group storage that should improve mount time on large
filesystems
Cleanups:
- cleaned up (and slightly sped up) set/get helpers for metadata data
structure members
- root bit REF_COWS got renamed to SHAREABLE to reflect the that the
blocks of the tree get shared either among subvolumes or with the
relocation trees
Fixes:
- when subvolume deletion fails due to ENOSPC, the filesystem is not
turned read-only
- device scan deals with devices from other filesystems that changed
ownership due to overwrite (mkfs)
- fix a race between scrub and block group removal/allocation
- fix long standing bug of a runaway balance operation, printing the
same line to the syslog, caused by a stale status bit on a reloc
tree that prevented progress
- fix corrupt log due to concurrent fsync of inodes with shared
extents
- fix space underflow for NODATACOW and buffered writes when it for
some reason needs to fallback to COW mode"
* tag 'for-5.8-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (133 commits)
btrfs: fix space_info bytes_may_use underflow during space cache writeout
btrfs: fix space_info bytes_may_use underflow after nocow buffered write
btrfs: fix wrong file range cleanup after an error filling dealloc range
btrfs: remove redundant local variable in read_block_for_search
btrfs: open code key_search
btrfs: split btrfs_direct_IO to read and write part
btrfs: remove BTRFS_INODE_READDIO_NEED_LOCK
fs: remove dio_end_io()
btrfs: switch to iomap_dio_rw() for dio
iomap: remove lockdep_assert_held()
iomap: add a filesystem hook for direct I/O bio submission
fs: export generic_file_buffered_read()
btrfs: turn space cache writeout failure messages into debug messages
btrfs: include error on messages about failure to write space/inode caches
btrfs: remove useless 'fail_unlock' label from btrfs_csum_file_blocks()
btrfs: do not ignore error from btrfs_next_leaf() when inserting checksums
btrfs: make checksum item extension more efficient
btrfs: fix corrupt log due to concurrent fsync of inodes with shared extents
btrfs: unexport btrfs_compress_set_level()
btrfs: simplify iget helpers
...
Merge updates from Andrew Morton:
"A few little subsystems and a start of a lot of MM patches.
Subsystems affected by this patch series: squashfs, ocfs2, parisc,
vfs. With mm subsystems: slab-generic, slub, debug, pagecache, gup,
swap, memcg, pagemap, memory-failure, vmalloc, kasan"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (128 commits)
kasan: move kasan_report() into report.c
mm/mm_init.c: report kasan-tag information stored in page->flags
ubsan: entirely disable alignment checks under UBSAN_TRAP
kasan: fix clang compilation warning due to stack protector
x86/mm: remove vmalloc faulting
mm: remove vmalloc_sync_(un)mappings()
x86/mm/32: implement arch_sync_kernel_mappings()
x86/mm/64: implement arch_sync_kernel_mappings()
mm/ioremap: track which page-table levels were modified
mm/vmalloc: track which page-table levels were modified
mm: add functions to track page directory modifications
s390: use __vmalloc_node in stack_alloc
powerpc: use __vmalloc_node in alloc_vm_stack
arm64: use __vmalloc_node in arch_alloc_vmap_stack
mm: remove vmalloc_user_node_flags
mm: switch the test_vmalloc module to use __vmalloc_node
mm: remove __vmalloc_node_flags_caller
mm: remove both instances of __vmalloc_node_flags
mm: remove the prot argument to __vmalloc_node
mm: remove the pgprot argument to __vmalloc
...
Since the new pair function is introduced, we can call them to clean the
code in btrfs.
Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: David Sterba <dsterba@suse.com>
Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Link: http://lkml.kernel.org/r/20200517214718.468-4-guoqing.jiang@cloud.ionos.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Implement the new readahead method in btrfs using the new
readahead_page_batch() function.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Cc: Chao Yu <yuchao0@huawei.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Gao Xiang <gaoxiang25@huawei.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Miklos Szeredi <mszeredi@redhat.com>
Link: http://lkml.kernel.org/r/20200414150233.24495-18-willy@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull uaccess/access_ok updates from Al Viro:
"Removals of trivially pointless access_ok() calls.
Note: the fiemap stuff was removed from the series, since they are
duplicates with part of ext4 series carried in Ted's tree"
* 'uaccess.access_ok' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
vmci_host: get rid of pointless access_ok()
hfi1: get rid of pointless access_ok()
usb: get rid of pointless access_ok() calls
lpfc_debugfs: get rid of pointless access_ok()
efi_test: get rid of pointless access_ok()
drm_read(): get rid of pointless access_ok()
via-pmu: don't bother with access_ok()
drivers/crypto/ccp/sev-dev.c: get rid of pointless access_ok()
omapfb: get rid of pointless access_ok() calls
amifb: get rid of pointless access_ok() calls
drivers/fpga/dfl-afu-dma-region.c: get rid of pointless access_ok()
drivers/fpga/dfl-fme-pr.c: get rid of pointless access_ok()
cm4000_cs.c cmm_ioctl(): get rid of pointless access_ok()
nvram: drop useless access_ok()
n_hdlc_tty_read(): remove pointless access_ok()
tomoyo_write_control(): get rid of pointless access_ok()
btrfs_ioctl_send(): don't bother with access_ok()
fat_dir_ioctl(): hadn't needed that access_ok() for more than a decade...
dlmfs_file_write(): get rid of pointless access_ok()
We always preallocate a data extent for writing a free space cache, which
causes writeback to always try the nocow path first, since the free space
inode has the prealloc bit set in its flags.
However if the block group that contains the data extent for the space
cache has been turned to RO mode due to a running scrub or balance for
example, we have to fallback to the cow path. In that case once a new data
extent is allocated we end up calling btrfs_add_reserved_bytes(), which
decrements the counter named bytes_may_use from the data space_info object
with the expection that this counter was previously incremented with the
same amount (the size of the data extent).
However when we started writeout of the space cache at cache_save_setup(),
we incremented the value of the bytes_may_use counter through a call to
btrfs_check_data_free_space() and then decremented it through a call to
btrfs_prealloc_file_range_trans() immediately after. So when starting the
writeback if we fallback to cow mode we have to increment the counter
bytes_may_use of the data space_info again to compensate for the extent
allocation done by the cow path.
When this issue happens we are incorrectly decrementing the bytes_may_use
counter and when its current value is smaller then the amount we try to
subtract we end up with the following warning:
------------[ cut here ]------------
WARNING: CPU: 3 PID: 657 at fs/btrfs/space-info.h:115 btrfs_add_reserved_bytes+0x3d6/0x4e0 [btrfs]
Modules linked in: btrfs blake2b_generic xor raid6_pq libcrc32c (...)
CPU: 3 PID: 657 Comm: kworker/u8:7 Tainted: G W 5.6.0-rc7-btrfs-next-58 #5
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
Workqueue: writeback wb_workfn (flush-btrfs-1591)
RIP: 0010:btrfs_add_reserved_bytes+0x3d6/0x4e0 [btrfs]
Code: ff ff 48 (...)
RSP: 0000:ffffa41608f13660 EFLAGS: 00010287
RAX: 0000000000001000 RBX: ffff9615b93ae400 RCX: 0000000000000000
RDX: 0000000000000002 RSI: 0000000000000000 RDI: ffff9615b96ab410
RBP: fffffffffffee000 R08: 0000000000000001 R09: 0000000000000000
R10: ffff961585e62a40 R11: 0000000000000000 R12: ffff9615b96ab400
R13: ffff9615a1a2a000 R14: 0000000000012000 R15: ffff9615b93ae400
FS: 0000000000000000(0000) GS:ffff9615bb200000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055cbbc2ae178 CR3: 0000000115794006 CR4: 00000000003606e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
find_free_extent+0x4a0/0x16c0 [btrfs]
btrfs_reserve_extent+0x91/0x180 [btrfs]
cow_file_range+0x12d/0x490 [btrfs]
btrfs_run_delalloc_range+0x9f/0x6d0 [btrfs]
? find_lock_delalloc_range+0x221/0x250 [btrfs]
writepage_delalloc+0xe8/0x150 [btrfs]
__extent_writepage+0xe8/0x4c0 [btrfs]
extent_write_cache_pages+0x237/0x530 [btrfs]
extent_writepages+0x44/0xa0 [btrfs]
do_writepages+0x23/0x80
__writeback_single_inode+0x59/0x700
writeback_sb_inodes+0x267/0x5f0
__writeback_inodes_wb+0x87/0xe0
wb_writeback+0x382/0x590
? wb_workfn+0x4a2/0x6c0
wb_workfn+0x4a2/0x6c0
process_one_work+0x26d/0x6a0
worker_thread+0x4f/0x3e0
? process_one_work+0x6a0/0x6a0
kthread+0x103/0x140
? kthread_create_worker_on_cpu+0x70/0x70
ret_from_fork+0x3a/0x50
irq event stamp: 0
hardirqs last enabled at (0): [<0000000000000000>] 0x0
hardirqs last disabled at (0): [<ffffffffb2abdedf>] copy_process+0x74f/0x2020
softirqs last enabled at (0): [<ffffffffb2abdedf>] copy_process+0x74f/0x2020
softirqs last disabled at (0): [<0000000000000000>] 0x0
---[ end trace bd7c03622e0b0a52 ]---
------------[ cut here ]------------
So fix this by incrementing the bytes_may_use counter of the data
space_info when we fallback to the cow path. If the cow path is successful
the counter is decremented after extent allocation (by
btrfs_add_reserved_bytes()), if it fails it ends up being decremented as
well when clearing the delalloc range (extent_clear_unlock_delalloc()).
This could be triggered sporadically by the test case btrfs/061 from
fstests.
Fixes: 82d5902d9c ("Btrfs: Support reading/writing on disk free ino cache")
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When doing a buffered write we always try to reserve data space for it,
even when the file has the NOCOW bit set or the write falls into a file
range covered by a prealloc extent. This is done both because it is
expensive to check if we can do a nocow write (checking if an extent is
shared through reflinks or if there's a hole in the range for example),
and because when writeback starts we might actually need to fallback to
COW mode (for example the block group containing the target extents was
turned into RO mode due to a scrub or balance).
When we are unable to reserve data space we check if we can do a nocow
write, and if we can, we proceed with dirtying the pages and setting up
the range for delalloc. In this case the bytes_may_use counter of the
data space_info object is not incremented, unlike in the case where we
are able to reserve data space (done through btrfs_check_data_free_space()
which calls btrfs_alloc_data_chunk_ondemand()).
Later when running delalloc we attempt to start writeback in nocow mode
but we might revert back to cow mode, for example because in the meanwhile
a block group was turned into RO mode by a scrub or relocation. The cow
path after successfully allocating an extent ends up calling
btrfs_add_reserved_bytes(), which expects the bytes_may_use counter of
the data space_info object to have been incremented before - but we did
not do it when the buffered write started, since there was not enough
available data space. So btrfs_add_reserved_bytes() ends up decrementing
the bytes_may_use counter anyway, and when the counter's current value
is smaller then the size of the allocated extent we get a stack trace
like the following:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 20138 at fs/btrfs/space-info.h:115 btrfs_add_reserved_bytes+0x3d6/0x4e0 [btrfs]
Modules linked in: btrfs blake2b_generic xor raid6_pq libcrc32c (...)
CPU: 0 PID: 20138 Comm: kworker/u8:15 Not tainted 5.6.0-rc7-btrfs-next-58 #5
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
Workqueue: writeback wb_workfn (flush-btrfs-1754)
RIP: 0010:btrfs_add_reserved_bytes+0x3d6/0x4e0 [btrfs]
Code: ff ff 48 (...)
RSP: 0018:ffffbda18a4b3568 EFLAGS: 00010287
RAX: 0000000000000000 RBX: ffff9ca076f5d800 RCX: 0000000000000000
RDX: 0000000000000002 RSI: 0000000000000000 RDI: ffff9ca068470410
RBP: fffffffffffff000 R08: 0000000000000001 R09: 0000000000000000
R10: ffff9ca079d58040 R11: 0000000000000000 R12: ffff9ca068470400
R13: ffff9ca0408b2000 R14: 0000000000001000 R15: ffff9ca076f5d800
FS: 0000000000000000(0000) GS:ffff9ca07a600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005605dbfe7048 CR3: 0000000138570006 CR4: 00000000003606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
find_free_extent+0x4a0/0x16c0 [btrfs]
btrfs_reserve_extent+0x91/0x180 [btrfs]
cow_file_range+0x12d/0x490 [btrfs]
run_delalloc_nocow+0x341/0xa40 [btrfs]
btrfs_run_delalloc_range+0x1ea/0x6d0 [btrfs]
? find_lock_delalloc_range+0x221/0x250 [btrfs]
writepage_delalloc+0xe8/0x150 [btrfs]
__extent_writepage+0xe8/0x4c0 [btrfs]
extent_write_cache_pages+0x237/0x530 [btrfs]
? btrfs_wq_submit_bio+0x9f/0xc0 [btrfs]
extent_writepages+0x44/0xa0 [btrfs]
do_writepages+0x23/0x80
__writeback_single_inode+0x59/0x700
writeback_sb_inodes+0x267/0x5f0
__writeback_inodes_wb+0x87/0xe0
wb_writeback+0x382/0x590
? wb_workfn+0x4a2/0x6c0
wb_workfn+0x4a2/0x6c0
process_one_work+0x26d/0x6a0
worker_thread+0x4f/0x3e0
? process_one_work+0x6a0/0x6a0
kthread+0x103/0x140
? kthread_create_worker_on_cpu+0x70/0x70
ret_from_fork+0x3a/0x50
irq event stamp: 0
hardirqs last enabled at (0): [<0000000000000000>] 0x0
hardirqs last disabled at (0): [<ffffffff94ebdedf>] copy_process+0x74f/0x2020
softirqs last enabled at (0): [<ffffffff94ebdedf>] copy_process+0x74f/0x2020
softirqs last disabled at (0): [<0000000000000000>] 0x0
---[ end trace f9f6ef8ec4cd8ec9 ]---
So to fix this, when falling back into cow mode check if space was not
reserved, by testing for the bit EXTENT_NORESERVE in the respective file
range, and if not, increment the bytes_may_use counter for the data
space_info object. Also clear the EXTENT_NORESERVE bit from the range, so
that if the cow path fails it decrements the bytes_may_use counter when
clearing the delalloc range (through the btrfs_clear_delalloc_extent()
callback).
Fixes: 7ee9e4405f ("Btrfs: check if we can nocow if we don't have data space")
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
If an error happens while running dellaloc in COW mode for a range, we can
end up calling extent_clear_unlock_delalloc() for a range that goes beyond
our range's end offset by 1 byte, which affects 1 extra page. This results
in clearing bits and doing page operations (such as a page unlock) outside
our target range.
Fix that by calling extent_clear_unlock_delalloc() with an inclusive end
offset, instead of an exclusive end offset, at cow_file_range().
Fixes: a315e68f6e ("Btrfs: fix invalid attempt to free reserved space on failure to cow range")
CC: stable@vger.kernel.org # 4.14+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The local 'b' variable is only used to directly read values from passed
extent buffer. So eliminate it and directly use the input parameter.
Furthermore this shrinks the size of the following functions:
./scripts/bloat-o-meter ctree.orig fs/btrfs/ctree.o
add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-73 (-73)
Function old new delta
read_block_for_search.isra 876 871 -5
push_node_left 1112 1044 -68
Total: Before=50348, After=50275, chg -0.14%
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This function wraps the optimisation implemented by d7396f0735
("Btrfs: optimize key searches in btrfs_search_slot") however this
optimisation is really used in only one place - btrfs_search_slot.
Just open code the optimisation and also add a comment explaining how it
works since it's not clear just by looking at the code - the key point
here is it depends on an internal invariant that BTRFS' btree provides,
namely intermediate pointers always contain the key at slot0 at the
child node. So in the case of exact match we can safely assume that the
given key will always be in slot 0 on lower levels.
Furthermore this results in a reduction of btrfs_search_slot's size:
./scripts/bloat-o-meter ctree.orig fs/btrfs/ctree.o
add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-75 (-75)
Function old new delta
btrfs_search_slot 2783 2708 -75
Total: Before=50423, After=50348, chg -0.15%
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The read and write versions don't have anything in common except for the
call to iomap_dio_rw. So split this function, and merge each half into
its only caller.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Since we now perform direct reads using i_rwsem, we can remove this
inode flag used to co-ordinate unlocked reads.
The truncate call takes i_rwsem. This means it is correctly synchronized
with concurrent direct reads.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <jth@kernel.org>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Switch from __blockdev_direct_IO() to iomap_dio_rw().
Rename btrfs_get_blocks_direct() to btrfs_dio_iomap_begin() and use it
as iomap_begin() for iomap direct I/O functions. This function
allocates and locks all the blocks required for the I/O.
btrfs_submit_direct() is used as the submit_io() hook for direct I/O
ops.
Since we need direct I/O reads to go through iomap_dio_rw(), we change
file_operations.read_iter() to a btrfs_file_read_iter() which calls
btrfs_direct_IO() for direct reads and falls back to
generic_file_buffered_read() for incomplete reads and buffered reads.
We don't need address_space.direct_IO() anymore so set it to noop.
Similarly, we don't need flags used in __blockdev_direct_IO(). iomap is
capable of direct I/O reads from a hole, so we don't need to return
-ENOENT.
BTRFS direct I/O is now done under i_rwsem, shared in case of reads and
exclusive in case of writes. This guards against simultaneous truncates.
Use iomap->iomap_end() to check for failed or incomplete direct I/O:
- for writes, call __endio_write_update_ordered()
- for reads, unlock extents
btrfs_dio_data is now hooked in iomap->private and not
current->journal_info. It carries the reservation variable and the
amount of data submitted, so we can calculate the amount of data to call
__endio_write_update_ordered in case of an error.
This patch removes last use of struct buffer_head from btrfs.
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Since commit 1afb648e94 ("btrfs: use standard debug config option to
enable free-space-cache debug prints"), we started to log error messages
that were never logged before since there was no DEBUG macro defined
anywhere. This started to make test case btrfs/187 to fail very often,
as it greps for any btrfs error messages in dmesg/syslog and fails if
any is found:
(...)
btrfs/186 1s ... 2s
btrfs/187 - output mismatch (see .../results//btrfs/187.out.bad)
\--- tests/btrfs/187.out 2019-05-17 12:48:32.537340749 +0100
\+++ /home/fdmanana/git/hub/xfstests/results//btrfs/187.out.bad ...
\@@ -1,3 +1,8 @@
QA output created by 187
Create a readonly snapshot of 'SCRATCH_MNT' in 'SCRATCH_MNT/snap1'
Create a readonly snapshot of 'SCRATCH_MNT' in 'SCRATCH_MNT/snap2'
+[268364.139958] BTRFS error (device sdc): failed to write free space cache for block group 30408704
+[268380.156503] BTRFS error (device sdc): failed to write free space cache for block group 30408704
+[268380.161703] BTRFS error (device sdc): failed to write free space cache for block group 30408704
+[268380.253180] BTRFS error (device sdc): failed to write free space cache for block group 30408704
...
(Run 'diff -u /home/fdmanana/git/hub/xfstests/tests/btrfs/187.out ...
btrfs/188 4s ... 2s
(...)
The space cache write failures happen due to ENOSPC when attempting to
update the free space cache items in the root tree. This happens because
when starting or joining a transaction we don't know how many block
groups we will end up changing (due to extent allocation or release) and
therefore never reserve space for updating free space cache items.
More often than not, the free space cache writeout succeeds since the
metadata space info is not yet full nor very close to being full, but
when it is, the space cache writeout fails with ENOSPC.
Occasional failures to write space caches are not considered critical
since they can be rebuilt when mounting the filesystem or the next
attempt to write a free space cache in the next transaction commit might
succeed, so we used to hide those error messages with a preprocessor
check for the existence of the DEBUG macro that was never enabled
anywhere.
A few other generic test cases also trigger the error messages due to
ENOSPC failure when writing free space caches as well, however they don't
fail since they don't grep dmesg/syslog for any btrfs specific error
messages.
So change the messages from 'error' level to 'debug' level, as it doesn't
make much sense to have error messages triggered only if the debug macro
is enabled plus, more importantly, the error is not serious nor highly
unexpected.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently the error messages logged when we fail to write a free space
cache or an inode cache are not very useful as they don't mention what
was the error. So include the error number in the messages.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The label 'fail_unlock' is pointless, all it does is to jump to the label
'out', so just remove it.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We are currently treating any non-zero return value from btrfs_next_leaf()
the same way, by going to the code that inserts a new checksum item in the
tree. However if btrfs_next_leaf() returns an error (a value < 0), we
should just stop and return the error, and not behave as if nothing has
happened, since in that case we do not have a way to know if there is a
next leaf or we are currently at the last leaf already.
So fix that by returning the error from btrfs_next_leaf().
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When we want to add checksums into the checksums tree, or a log tree, we
try whenever possible to extend existing checksum items, as this helps
reduce amount of metadata space used, since adding a new item uses extra
metadata space for a btrfs_item structure (25 bytes).
However we have two inefficiencies in the current approach:
1) After finding a checksum item that covers a range with an end offset
that matches the start offset of the checksum range we want to insert,
we release the search path populated by btrfs_lookup_csum() and then
do another COW search on tree with the goal of getting additional
space for at least one checksum. Doing this path release and then
searching again is a waste of time because very often the leaf already
has enough free space for at least one more checksum;
2) After the COW search that guarantees we get free space in the leaf for
at least one more checksum, we end up not doing the extension of the
previous checksum item, and fallback to insertion of a new checksum
item, if the leaf doesn't have an amount of free space larger then the
space required for 2 checksums plus one btrfs_item structure - this is
pointless for two reasons:
a) We want to extend an existing item, so we don't need to account for
a btrfs_item structure (25 bytes);
b) We made the COW search with an insertion size for 1 single checksum,
so if the leaf ends up with a free space amount smaller then 2
checksums plus the size of a btrfs_item structure, we give up on the
extension of the existing item and jump to the 'insert' label, where
we end up releasing the path and then doing yet another search to
insert a new checksum item for a single checksum.
Fix these inefficiencies by doing the following:
- For case 1), before releasing the path just check if the leaf already
has enough space for at least 1 more checksum, and if it does, jump
directly to the item extension code, with releasing our current path,
which was already COWed by btrfs_lookup_csum();
- For case 2), fix the logic so that for item extension we require only
that the leaf has enough free space for 1 checksum, and not a minimum
of 2 checksums plus space for a btrfs_item structure.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When we have extents shared amongst different inodes in the same subvolume,
if we fsync them in parallel we can end up with checksum items in the log
tree that represent ranges which overlap.
For example, consider we have inodes A and B, both sharing an extent that
covers the logical range from X to X + 64KiB:
1) Task A starts an fsync on inode A;
2) Task B starts an fsync on inode B;
3) Task A calls btrfs_csum_file_blocks(), and the first search in the
log tree, through btrfs_lookup_csum(), returns -EFBIG because it
finds an existing checksum item that covers the range from X - 64KiB
to X;
4) Task A checks that the checksum item has not reached the maximum
possible size (MAX_CSUM_ITEMS) and then releases the search path
before it does another path search for insertion (through a direct
call to btrfs_search_slot());
5) As soon as task A releases the path and before it does the search
for insertion, task B calls btrfs_csum_file_blocks() and gets -EFBIG
too, because there is an existing checksum item that has an end
offset that matches the start offset (X) of the checksum range we want
to log;
6) Task B releases the path;
7) Task A does the path search for insertion (through btrfs_search_slot())
and then verifies that the checksum item that ends at offset X still
exists and extends its size to insert the checksums for the range from
X to X + 64KiB;
8) Task A releases the path and returns from btrfs_csum_file_blocks(),
having inserted the checksums into an existing checksum item that got
its size extended. At this point we have one checksum item in the log
tree that covers the logical range from X - 64KiB to X + 64KiB;
9) Task B now does a search for insertion using btrfs_search_slot() too,
but it finds that the previous checksum item no longer ends at the
offset X, it now ends at an of offset X + 64KiB, so it leaves that item
untouched.
Then it releases the path and calls btrfs_insert_empty_item()
that inserts a checksum item with a key offset corresponding to X and
a size for inserting a single checksum (4 bytes in case of crc32c).
Subsequent iterations end up extending this new checksum item so that
it contains the checksums for the range from X to X + 64KiB.
So after task B returns from btrfs_csum_file_blocks() we end up with
two checksum items in the log tree that have overlapping ranges, one
for the range from X - 64KiB to X + 64KiB, and another for the range
from X to X + 64KiB.
Having checksum items that represent ranges which overlap, regardless of
being in the log tree or in the chekcsums tree, can lead to problems where
checksums for a file range end up not being found. This type of problem
has happened a few times in the past and the following commits fixed them
and explain in detail why having checksum items with overlapping ranges is
problematic:
27b9a8122f "Btrfs: fix csum tree corruption, duplicate and outdated checksums"
b84b8390d6 "Btrfs: fix file read corruption after extent cloning and fsync"
40e046acbd "Btrfs: fix missing data checksums after replaying a log tree"
Since this specific instance of the problem can only happen when logging
inodes, because it is the only case where concurrent attempts to insert
checksums for the same range can happen, fix the issue by using an extent
io tree as a range lock to serialize checksum insertion during inode
logging.
This issue could often be reproduced by the test case generic/457 from
fstests. When it happens it produces the following trace:
BTRFS critical (device dm-0): corrupt leaf: root=18446744073709551610 block=30625792 slot=42, csum end range (15020032) goes beyond the start range (15015936) of the next csum item
BTRFS info (device dm-0): leaf 30625792 gen 7 total ptrs 49 free space 2402 owner 18446744073709551610
BTRFS info (device dm-0): refs 1 lock (w:0 r:0 bw:0 br:0 sw:0 sr:0) lock_owner 0 current 15884
item 0 key (18446744073709551606 128 13979648) itemoff 3991 itemsize 4
item 1 key (18446744073709551606 128 13983744) itemoff 3987 itemsize 4
item 2 key (18446744073709551606 128 13987840) itemoff 3983 itemsize 4
item 3 key (18446744073709551606 128 13991936) itemoff 3979 itemsize 4
item 4 key (18446744073709551606 128 13996032) itemoff 3975 itemsize 4
item 5 key (18446744073709551606 128 14000128) itemoff 3971 itemsize 4
(...)
BTRFS error (device dm-0): block=30625792 write time tree block corruption detected
------------[ cut here ]------------
WARNING: CPU: 1 PID: 15884 at fs/btrfs/disk-io.c:539 btree_csum_one_bio+0x268/0x2d0 [btrfs]
Modules linked in: btrfs dm_thin_pool ...
CPU: 1 PID: 15884 Comm: fsx Tainted: G W 5.6.0-rc7-btrfs-next-58 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
RIP: 0010:btree_csum_one_bio+0x268/0x2d0 [btrfs]
Code: c7 c7 ...
RSP: 0018:ffffbb0109e6f8e0 EFLAGS: 00010296
RAX: 0000000000000000 RBX: ffffe1c0847b6080 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffffaa963988 RDI: 0000000000000001
RBP: ffff956a4f4d2000 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000526 R11: 0000000000000000 R12: ffff956a5cd28bb0
R13: 0000000000000000 R14: ffff956a649c9388 R15: 000000011ed82000
FS: 00007fb419959e80(0000) GS:ffff956a7aa00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000fe6d54 CR3: 0000000138696005 CR4: 00000000003606e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
btree_submit_bio_hook+0x67/0xc0 [btrfs]
submit_one_bio+0x31/0x50 [btrfs]
btree_write_cache_pages+0x2db/0x4b0 [btrfs]
? __filemap_fdatawrite_range+0xb1/0x110
do_writepages+0x23/0x80
__filemap_fdatawrite_range+0xd2/0x110
btrfs_write_marked_extents+0x15e/0x180 [btrfs]
btrfs_sync_log+0x206/0x10a0 [btrfs]
? kmem_cache_free+0x315/0x3b0
? btrfs_log_inode+0x1e8/0xf90 [btrfs]
? __mutex_unlock_slowpath+0x45/0x2a0
? lockref_put_or_lock+0x9/0x30
? dput+0x2d/0x580
? dput+0xb5/0x580
? btrfs_sync_file+0x464/0x4d0 [btrfs]
btrfs_sync_file+0x464/0x4d0 [btrfs]
do_fsync+0x38/0x60
__x64_sys_fsync+0x10/0x20
do_syscall_64+0x5c/0x280
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7fb41953a6d0
Code: 48 3d ...
RSP: 002b:00007ffcc86bd218 EFLAGS: 00000246 ORIG_RAX: 000000000000004a
RAX: ffffffffffffffda RBX: 000000000000000d RCX: 00007fb41953a6d0
RDX: 0000000000000009 RSI: 0000000000040000 RDI: 0000000000000003
RBP: 0000000000040000 R08: 0000000000000001 R09: 0000000000000009
R10: 0000000000000064 R11: 0000000000000246 R12: 0000556cf4b2c060
R13: 0000000000000100 R14: 0000000000000000 R15: 0000556cf322b420
irq event stamp: 0
hardirqs last enabled at (0): [<0000000000000000>] 0x0
hardirqs last disabled at (0): [<ffffffffa96bdedf>] copy_process+0x74f/0x2020
softirqs last enabled at (0): [<ffffffffa96bdedf>] copy_process+0x74f/0x2020
softirqs last disabled at (0): [<0000000000000000>] 0x0
---[ end trace d543fc76f5ad7fd8 ]---
In that trace the tree checker detected the overlapping checksum items at
the time when we triggered writeback for the log tree when syncing the
log.
Another trace that can happen is due to BUG_ON() when deleting checksum
items while logging an inode:
BTRFS critical (device dm-0): slot 81 key (18446744073709551606 128 13635584) new key (18446744073709551606 128 13635584)
BTRFS info (device dm-0): leaf 30949376 gen 7 total ptrs 98 free space 8527 owner 18446744073709551610
BTRFS info (device dm-0): refs 4 lock (w:1 r:0 bw:0 br:0 sw:1 sr:0) lock_owner 13473 current 13473
item 0 key (257 1 0) itemoff 16123 itemsize 160
inode generation 7 size 262144 mode 100600
item 1 key (257 12 256) itemoff 16103 itemsize 20
item 2 key (257 108 0) itemoff 16050 itemsize 53
extent data disk bytenr 13631488 nr 4096
extent data offset 0 nr 131072 ram 131072
(...)
------------[ cut here ]------------
kernel BUG at fs/btrfs/ctree.c:3153!
invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI
CPU: 1 PID: 13473 Comm: fsx Not tainted 5.6.0-rc7-btrfs-next-58 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
RIP: 0010:btrfs_set_item_key_safe+0x1ea/0x270 [btrfs]
Code: 0f b6 ...
RSP: 0018:ffff95e3889179d0 EFLAGS: 00010282
RAX: 0000000000000000 RBX: 0000000000000051 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffffb7763988 RDI: 0000000000000001
RBP: fffffffffffffff6 R08: 0000000000000000 R09: 0000000000000001
R10: 00000000000009ef R11: 0000000000000000 R12: ffff8912a8ba5a08
R13: ffff95e388917a06 R14: ffff89138dcf68c8 R15: ffff95e388917ace
FS: 00007fe587084e80(0000) GS:ffff8913baa00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe587091000 CR3: 0000000126dac005 CR4: 00000000003606e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
btrfs_del_csums+0x2f4/0x540 [btrfs]
copy_items+0x4b5/0x560 [btrfs]
btrfs_log_inode+0x910/0xf90 [btrfs]
btrfs_log_inode_parent+0x2a0/0xe40 [btrfs]
? dget_parent+0x5/0x370
btrfs_log_dentry_safe+0x4a/0x70 [btrfs]
btrfs_sync_file+0x42b/0x4d0 [btrfs]
__x64_sys_msync+0x199/0x200
do_syscall_64+0x5c/0x280
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7fe586c65760
Code: 00 f7 ...
RSP: 002b:00007ffe250f98b8 EFLAGS: 00000246 ORIG_RAX: 000000000000001a
RAX: ffffffffffffffda RBX: 00000000000040e1 RCX: 00007fe586c65760
RDX: 0000000000000004 RSI: 0000000000006b51 RDI: 00007fe58708b000
RBP: 0000000000006a70 R08: 0000000000000003 R09: 00007fe58700cb61
R10: 0000000000000100 R11: 0000000000000246 R12: 00000000000000e1
R13: 00007fe58708b000 R14: 0000000000006b51 R15: 0000558de021a420
Modules linked in: dm_log_writes ...
---[ end trace c92a7f447a8515f5 ]---
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
btrfs_compress_set_level() can be static function in the file
compression.c.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The inode lookup starting at btrfs_iget takes the full location key,
while only the objectid is used to match the inode, because the lookup
happens inside the given root thus the inode number is unique.
The entire location key is properly set up in btrfs_init_locked_inode.
Simplify the helpers and pass only inode number, renaming it to 'ino'
instead of 'objectid'. This allows to remove temporary variables key,
saving some stack space.
Signed-off-by: David Sterba <dsterba@suse.com>
The main function to lookup a root by its id btrfs_get_fs_root takes the
whole key, while only using the objectid. The value of offset is preset
to (u64)-1 but not actually used until btrfs_find_root that does the
actual search.
Switch btrfs_get_fs_root to use only objectid and remove all local
variables that existed just for the lookup. The actual key for search is
set up in btrfs_get_fs_root, reusing another key variable.
Signed-off-by: David Sterba <dsterba@suse.com>
[BUG]
There are several reported runaway balance, that balance is flooding the
log with "found X extents" where the X never changes.
[CAUSE]
Commit d2311e6985 ("btrfs: relocation: Delay reloc tree deletion after
merge_reloc_roots") introduced BTRFS_ROOT_DEAD_RELOC_TREE bit to
indicate that one subvolume has finished its tree blocks swap with its
reloc tree.
However if balance is canceled or hits ENOSPC halfway, we didn't clear
the BTRFS_ROOT_DEAD_RELOC_TREE bit, leaving that bit hanging forever
until unmount.
Any subvolume root with that bit, would cause backref cache to skip this
tree block, as it has finished its tree block swap. This would cause
all tree blocks of that root be ignored by balance, leading to runaway
balance.
[FIX]
Fix the problem by also clearing the BTRFS_ROOT_DEAD_RELOC_TREE bit for
the original subvolume of orphan reloc root.
Add an umount check for the stale bit still set.
Fixes: d2311e6985 ("btrfs: relocation: Delay reloc tree deletion after merge_reloc_roots")
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When creating a snapshot, ordered extents need to be flushed and this
can take a long time.
In create_snapshot there are two locks held when this happens:
1. Destination directory inode lock
2. Global subvolume semaphore
This will unnecessarily block other operations like subvolume destroy,
create, or setflag until the snapshot is created.
We can fix that by moving the flush outside the locked section as this
does not depend on the aforementioned locks. The code factors out the
snapshot related work from create_snapshot to btrfs_mksnapshot.
__btrfs_ioctl_snap_create
btrfs_mksubvol
create_subvol
btrfs_mksnapshot
<flush>
btrfs_mksubvol
create_snapshot
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Robbie Ko <robbieko@synology.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
SHAREABLE flag is set for subvolumes because users can create snapshot
for subvolumes, thus sharing tree blocks of them.
But data reloc tree is not exposed to user space, as it's only an
internal tree for data relocation, thus it doesn't need the full path
replacement handling at all.
This patch will make data reloc tree a non-shareable tree, and add
btrfs_fs_info::data_reloc_root for data reloc tree, so relocation code
can grab it from fs_info directly.
This would slightly improve tree relocation, as now data reloc tree
can go through regular COW routine to get relocated, without bothering
the complex tree reloc tree routine.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There are a lot of root owner checks in btrfs_truncate_inode_items()
like:
if (test_bit(BTRFS_ROOT_SHAREABLE, &root->state) ||
root == fs_info->tree_root)
But considering that, only these trees can have INODE_ITEMs:
- tree root (for v1 space cache)
- subvolume trees
- tree reloc trees
- data reloc tree
- log trees
And since subvolume/tree reloc/data reloc trees all have SHAREABLE bit,
and we're checking tree root manually, so above check is just excluding
log trees.
This patch will replace two of such checks to a simpler one:
if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
This would merge btrfs_drop_extent_cache() and lock_extent_bits() call
into the same if branch.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The name BTRFS_ROOT_REF_COWS is not very clear about the meaning.
In fact, that bit can only be set to those trees:
- Subvolume roots
- Data reloc root
- Reloc roots for above roots
All other trees won't get this bit set. So just by the result, it is
obvious that, roots with this bit set can have tree blocks shared with
other trees. Either shared by snapshots, or by reloc roots (an special
snapshot created by relocation).
This patch will rename BTRFS_ROOT_REF_COWS to BTRFS_ROOT_SHAREABLE to
make it easier to understand, and update all comment mentioning
"reference counted" to follow the rename.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Commit dccdb07bc9 ("btrfs: kill btrfs_fs_info::volume_mutex") removed
the last use of the volume_mutex, forgetting to update the comment.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The fallback path calls helper write_extent_buffer to do write of the
data spanning two extent buffer pages. As the size is known, we can do
the write directly in two steps. This removes one function call and
compiler can optimize memcpy as the sizes are known at compile time. The
cached token address is set to the second page.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The helper write_extent_buffer is called to do write of the data
spanning two extent buffer pages. As the size is known, we can do the
write directly in two steps. This removes one function call and
compiler can optimize memcpy as the sizes are known at compile time.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The fallback path calls helper read_extent_buffer to do read of the data
spanning two extent buffer pages. As the size is known, we can do the
read directly in two steps. This removes one function call and compiler
can optimize memcpy as the sizes are known at compile time. The cached
token address is set to the second page.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The helper read_extent_buffer is called to do read of the data spanning
two extent buffer pages. As the size is known, we can do the read
directly in two steps. This removes one function call and compiler can
optimize memcpy as the sizes are known at compile time.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Helpers that iterate over extent buffer pages set up several variables,
one of them is finding out offset of the extent buffer start within a
page. Right now we have extent buffers aligned to page sizes so this is
effectively storing zero. This makes the code harder the follow and can
be simplified.
The same change is done in all the helpers:
* remove: size_t start_offset = offset_in_page(eb->start);
* simplify code using start_offset
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There are many helpers around extent buffers, found in extent_io.h and
ctree.h. Most of them can be converted to take constified eb as there
are no changes to the extent buffer structure itself but rather the
pages.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
All uses of map_private_extent_buffer have been replaced by more
effective way. The set/get helpers have their own bounds checker.
The function name was confusing since the non-private helper was removed
in a65917156e ("Btrfs: stop using highmem for extent_buffers") many
years ago.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The bin search jumps over the extent buffer item keys, comparing
directly the bytes if the key is in one page, or storing it in a
temporary buffer in case it spans two pages.
The mapping start and length are obtained from map_private_extent_buffer,
which is heavy weight compared to what we need. We know the key size and
can find out the eb page in a simple way. For keys spanning two pages
the fallback read_extent_buffer is used.
The temporary variables are reduced and moved to the scope of use.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The set/get token helpers either use the cached address in the token or
unconditionally call map_private_extent_buffer to get the address of
page containing the requested offset plus the mapping start and length.
Depending on the return value, the fast path uses unaligned put to write
data within a page, or fall back to write_extent_buffer that can handle
writes spanning more pages.
This is all wasteful. We know the number of bytes to write, 1/2/4/8 and
can find out the page. Then simply check if it's contained or the
fallback is needed. The token address is updated to the page, or the on
the next index, expecting that the next write will use that.
This saves one function call to map_private_extent_buffer and several
unnecessary temporary variables.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The helpers unconditionally call map_private_extent_buffer to get the
address of page containing the requested offset plus the mapping start
and length. Depending on the return value, the fast path uses unaligned
put to write data within a page, or fall back to write_extent_buffer
that can handle writes spanning more pages.
This is all wasteful. We know the number of bytes to write, 1/2/4/8 and
can find out the page. Then simply check if it's contained or the
fallback is needed.
This saves one function call to map_private_extent_buffer and several
unnecessary temporary variables.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The set/get token helpers either use the cached address in the token or
unconditionally call map_private_extent_buffer to get the address of
page containing the requested offset plus the mapping start and length.
Depending on the return value, the fast path uses unaligned read to get
data within a page, or fall back to read_extent_buffer that can handle
reads spanning more pages.
This is all wasteful. We know the number of bytes to read, 1/2/4/8 and
can find out the page. Then simply check if it's contained or the
fallback is needed. The token address is updated to the page, or the on
the next index, expecting that the next read will use that.
This saves one function call to map_private_extent_buffer and several
unnecessary temporary variables.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The helpers unconditionally call map_private_extent_buffer to get the
address of page containing the requested offset plus the mapping start
and length. Depending on the return value, the fast path uses unaligned
read to get data within a page, or fall back to read_extent_buffer that
can handle reads spanning more pages.
This is all wasteful. We know the number of bytes to read, 1/2/4/8 and
can find out the page. Then simply check if it's contained or the
fallback is needed.
This saves one function call to map_private_extent_buffer and several
unnecessary temporary variables.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The bounds checking is now done in map_private_extent_buffer but that
will be removed in following patches and some sanity checks should still
be done.
There are two separate checks to see the kind of out of bounds access:
partial (start offset is in the buffer) or complete (both start and end
are out).
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
All the set/get helpers first check if the token contains a cached
address. After first use the address is always valid, but the extra
check is done for each call.
The token initialization can optimistically set it to the first extent
buffer page, that we know always exists. Then the condition in all
btrfs_token_*/btrfs_set_token_* can be simplified by removing the
address check from the condition, but for development the assertion
still makes sure it's valid.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The token is supposed to cache the last page used by the set/get
helpers. In leaf_space_used the first and last items are accessed, it's
not likely they'd be on the same page so there's some overhead caused
updating the token address but not using it.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The set/get token is supposed to cache the last page that was accessed
so it speeds up subsequential access to the eb. It does not make sense
to use that for just one change, which is the case of inode size in
overwrite_item.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Now that all set/get helpers use the eb from the token, we don't need to
pass it to many btrfs_token_*/btrfs_set_token_* helpers, saving some
stack space.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The token stores a copy of the extent buffer pointer but does not make
any use of it besides sanity checks. We can use it and drop the eb
parameter from several functions, this patch only switches the use
inside the set/get helpers.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
disk-io.h is included more than once in block-group.c, remove it.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: David Sterba <dsterba@suse.com>
The name of this function contains the word "cache", which is left from
the times where btrfs_block_group was called btrfs_block_group_cache.
Now this "cache" doesn't match anything, and we have better namings for
functions like read/insert/remove_block_group_item().
Rename it to update_block_group_item().
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently the block group item insert is pretty straight forward, fill
the block group item structure and insert it into extent tree.
However the incoming skinny block group feature is going to change this,
so this patch will refactor insertion into a new function,
insert_block_group_item(), to make the incoming feature easier to add.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When deleting a block group item, it's pretty straight forward, just
delete the item pointed by the key. However it will not be that
straight-forward for incoming skinny block group item.
So refactor the block group item deletion into a new function,
remove_block_group_item(), also to make the already lengthy
btrfs_remove_block_group() a little shorter.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Structure btrfs_block_group has the following members which are
currently read from on-disk block group item and key:
- length - from item key
- used
- flags - from block group item
However for incoming skinny block group tree, we are going to read those
members from different sources.
This patch will refactor such read by:
- Don't initialize btrfs_block_group::length at allocation
Caller should initialize them manually.
Also to avoid possible (well, only two callers) missing
initialization, add extra ASSERT() in btrfs_add_block_group_cache().
- Refactor length/used/flags initialization into one function
The new function, fill_one_block_group() will handle the
initialization of such members.
- Use btrfs_block_group::length to replace key::offset
Since skinny block group item would have a different meaning for its
key offset.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Regular block group items in extent tree are scattered inside the huge
tree, thus forward readahead makes no sense.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Whenever a chown is executed, all capabilities of the file being touched
are lost. When doing incremental send with a file with capabilities,
there is a situation where the capability can be lost on the receiving
side. The sequence of actions bellow shows the problem:
$ mount /dev/sda fs1
$ mount /dev/sdb fs2
$ touch fs1/foo.bar
$ setcap cap_sys_nice+ep fs1/foo.bar
$ btrfs subvolume snapshot -r fs1 fs1/snap_init
$ btrfs send fs1/snap_init | btrfs receive fs2
$ chgrp adm fs1/foo.bar
$ setcap cap_sys_nice+ep fs1/foo.bar
$ btrfs subvolume snapshot -r fs1 fs1/snap_complete
$ btrfs subvolume snapshot -r fs1 fs1/snap_incremental
$ btrfs send fs1/snap_complete | btrfs receive fs2
$ btrfs send -p fs1/snap_init fs1/snap_incremental | btrfs receive fs2
At this point, only a chown was emitted by "btrfs send" since only the
group was changed. This makes the cap_sys_nice capability to be dropped
from fs2/snap_incremental/foo.bar
To fix that, only emit capabilities after chown is emitted. The current
code first checks for xattrs that are new/changed, emits them, and later
emit the chown. Now, __process_new_xattr skips capabilities, letting
only finish_inode_if_needed to emit them, if they exist, for the inode
being processed.
This behavior was being worked around in "btrfs receive" side by caching
the capability and only applying it after chown. Now, xattrs are only
emmited _after_ chown, making that workaround not needed anymore.
Link: https://github.com/kdave/btrfs-progs/issues/202
CC: stable@vger.kernel.org # 4.4+
Suggested-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When scrubbing a stripe, whenever we find an extent we lookup for its
checksums in the checksum tree. However we do it even for metadata extents
which don't have checksum items stored in the checksum tree, that is
only for data extents.
So make the lookup for checksums only if we are processing with a data
extent.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The helpers btrfs_freeze_block_group() and btrfs_unfreeze_block_group()
used to be named btrfs_get_block_group_trimming() and
btrfs_put_block_group_trimming() respectively.
At the time they were added to free-space-cache.c, by commit e33e17ee10
("btrfs: add missing discards when unpinning extents with -o discard")
because all the trimming related functions were in free-space-cache.c.
Now that the helpers were renamed and are used in scrub context as well,
move them to block-group.c, a much more logical location for them.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Back in 2014, commit 04216820fe ("Btrfs: fix race between fs trimming
and block group remove/allocation"), I added the 'trimming' member to the
block group structure. Its purpose was to prevent races between trimming
and block group deletion/allocation by pinning the block group in a way
that prevents its logical address and device extents from being reused
while trimming is in progress for a block group, so that if another task
deletes the block group and then another task allocates a new block group
that gets the same logical address and device extents while the trimming
task is still in progress.
After the previous fix for scrub (patch "btrfs: fix a race between scrub
and block group removal/allocation"), scrub now also has the same needs that
trimming has, so the member name 'trimming' no longer makes sense.
Since there is already a 'pinned' member in the block group that refers
to space reservations (pinned bytes), rename the member to 'frozen',
add a comment on top of it to describe its general purpose and rename
the helpers to increment and decrement the counter as well, to match
the new member name.
The next patch in the series will move the helpers into a more suitable
file (from free-space-cache.c to block-group.c).
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When scrub is verifying the extents of a block group for a device, it is
possible that the corresponding block group gets removed and its logical
address and device extents get used for a new block group allocation.
When this happens scrub incorrectly reports that errors were detected
and, if the the new block group has a different profile then the old one,
deleted block group, we can crash due to a null pointer dereference.
Possibly other unexpected and weird consequences can happen as well.
Consider the following sequence of actions that leads to the null pointer
dereference crash when scrub is running in parallel with balance:
1) Balance sets block group X to read-only mode and starts relocating it.
Block group X is a metadata block group, has a raid1 profile (two
device extents, each one in a different device) and a logical address
of 19424870400;
2) Scrub is running and finds device extent E, which belongs to block
group X. It enters scrub_stripe() to find all extents allocated to
block group X, the search is done using the extent tree;
3) Balance finishes relocating block group X and removes block group X;
4) Balance starts relocating another block group and when trying to
commit the current transaction as part of the preparation step
(prepare_to_relocate()), it blocks because scrub is running;
5) The scrub task finds the metadata extent at the logical address
19425001472 and marks the pages of the extent to be read by a bio
(struct scrub_bio). The extent item's flags, which have the bit
BTRFS_EXTENT_FLAG_TREE_BLOCK set, are added to each page (struct
scrub_page). It is these flags in the scrub pages that tells the
bio's end io function (scrub_bio_end_io_worker) which type of extent
it is dealing with. At this point we end up with 4 pages in a bio
which is ready for submission (the metadata extent has a size of
16Kb, so that gives 4 pages on x86);
6) At the next iteration of scrub_stripe(), scrub checks that there is a
pause request from the relocation task trying to commit a transaction,
therefore it submits the pending bio and pauses, waiting for the
transaction commit to complete before resuming;
7) The relocation task commits the transaction. The device extent E, that
was used by our block group X, is now available for allocation, since
the commit root for the device tree was swapped by the transaction
commit;
8) Another task doing a direct IO write allocates a new data block group Y
which ends using device extent E. This new block group Y also ends up
getting the same logical address that block group X had: 19424870400.
This happens because block group X was the block group with the highest
logical address and, when allocating Y, find_next_chunk() returns the
end offset of the current last block group to be used as the logical
address for the new block group, which is
18351128576 + 1073741824 = 19424870400
So our new block group Y has the same logical address and device extent
that block group X had. However Y is a data block group, while X was
a metadata one, and Y has a raid0 profile, while X had a raid1 profile;
9) After allocating block group Y, the direct IO submits a bio to write
to device extent E;
10) The read bio submitted by scrub reads the 4 pages (16Kb) from device
extent E, which now correspond to the data written by the task that
did a direct IO write. Then at the end io function associated with
the bio, scrub_bio_end_io_worker(), we call scrub_block_complete()
which calls scrub_checksum(). This later function checks the flags
of the first page, and sees that the bit BTRFS_EXTENT_FLAG_TREE_BLOCK
is set in the flags, so it assumes it has a metadata extent and
then calls scrub_checksum_tree_block(). That functions returns an
error, since interpreting data as a metadata extent causes the
checksum verification to fail.
So this makes scrub_checksum() call scrub_handle_errored_block(),
which determines 'failed_mirror_index' to be 1, since the device
extent E was allocated as the second mirror of block group X.
It allocates BTRFS_MAX_MIRRORS scrub_block structures as an array at
'sblocks_for_recheck', and all the memory is initialized to zeroes by
kcalloc().
After that it calls scrub_setup_recheck_block(), which is responsible
for filling each of those structures. However, when that function
calls btrfs_map_sblock() against the logical address of the metadata
extent, 19425001472, it gets a struct btrfs_bio ('bbio') that matches
the current block group Y. However block group Y has a raid0 profile
and not a raid1 profile like X had, so the following call returns 1:
scrub_nr_raid_mirrors(bbio)
And as a result scrub_setup_recheck_block() only initializes the
first (index 0) scrub_block structure in 'sblocks_for_recheck'.
Then scrub_recheck_block() is called by scrub_handle_errored_block()
with the second (index 1) scrub_block structure as the argument,
because 'failed_mirror_index' was previously set to 1.
This scrub_block was not initialized by scrub_setup_recheck_block(),
so it has zero pages, its 'page_count' member is 0 and its 'pagev'
page array has all members pointing to NULL.
Finally when scrub_recheck_block() calls scrub_recheck_block_checksum()
we have a NULL pointer dereference when accessing the flags of the first
page, as pavev[0] is NULL:
static void scrub_recheck_block_checksum(struct scrub_block *sblock)
{
(...)
if (sblock->pagev[0]->flags & BTRFS_EXTENT_FLAG_DATA)
scrub_checksum_data(sblock);
(...)
}
Producing a stack trace like the following:
[542998.008985] BUG: kernel NULL pointer dereference, address: 0000000000000028
[542998.010238] #PF: supervisor read access in kernel mode
[542998.010878] #PF: error_code(0x0000) - not-present page
[542998.011516] PGD 0 P4D 0
[542998.011929] Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI
[542998.012786] CPU: 3 PID: 4846 Comm: kworker/u8:1 Tainted: G B W 5.6.0-rc7-btrfs-next-58 #1
[542998.014524] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
[542998.016065] Workqueue: btrfs-scrub btrfs_work_helper [btrfs]
[542998.017255] RIP: 0010:scrub_recheck_block_checksum+0xf/0x20 [btrfs]
[542998.018474] Code: 4c 89 e6 ...
[542998.021419] RSP: 0018:ffffa7af0375fbd8 EFLAGS: 00010202
[542998.022120] RAX: 0000000000000000 RBX: ffff9792e674d120 RCX: 0000000000000000
[542998.023178] RDX: 0000000000000001 RSI: ffff9792e674d120 RDI: ffff9792e674d120
[542998.024465] RBP: 0000000000000000 R08: 0000000000000067 R09: 0000000000000001
[542998.025462] R10: ffffa7af0375fa50 R11: 0000000000000000 R12: ffff9791f61fe800
[542998.026357] R13: ffff9792e674d120 R14: 0000000000000001 R15: ffffffffc0e3dfc0
[542998.027237] FS: 0000000000000000(0000) GS:ffff9792fb200000(0000) knlGS:0000000000000000
[542998.028327] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[542998.029261] CR2: 0000000000000028 CR3: 00000000b3b18003 CR4: 00000000003606e0
[542998.030301] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[542998.031316] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[542998.032380] Call Trace:
[542998.032752] scrub_recheck_block+0x162/0x400 [btrfs]
[542998.033500] ? __alloc_pages_nodemask+0x31e/0x460
[542998.034228] scrub_handle_errored_block+0x6f8/0x1920 [btrfs]
[542998.035170] scrub_bio_end_io_worker+0x100/0x520 [btrfs]
[542998.035991] btrfs_work_helper+0xaa/0x720 [btrfs]
[542998.036735] process_one_work+0x26d/0x6a0
[542998.037275] worker_thread+0x4f/0x3e0
[542998.037740] ? process_one_work+0x6a0/0x6a0
[542998.038378] kthread+0x103/0x140
[542998.038789] ? kthread_create_worker_on_cpu+0x70/0x70
[542998.039419] ret_from_fork+0x3a/0x50
[542998.039875] Modules linked in: dm_snapshot dm_thin_pool ...
[542998.047288] CR2: 0000000000000028
[542998.047724] ---[ end trace bde186e176c7f96a ]---
This issue has been around for a long time, possibly since scrub exists.
The last time I ran into it was over 2 years ago. After recently fixing
fstests to pass the "--full-balance" command line option to btrfs-progs
when doing balance, several tests started to more heavily exercise balance
with fsstress, scrub and other operations in parallel, and therefore
started to hit this issue again (with btrfs/061 for example).
Fix this by having scrub increment the 'trimming' counter of the block
group, which pins the block group in such a way that it guarantees neither
its logical address nor device extents can be reused by future block group
allocations until we decrement the 'trimming' counter. Also make sure that
on each iteration of scrub_stripe() we stop scrubbing the block group if
it was removed already.
A later patch in the series will rename the block group's 'trimming'
counter and its helpers to a more generic name, since now it is not used
exclusively for pinning while trimming anymore.
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The extent references v0 have been superseded long time go, there are
some unused declarations of access helpers. We can safely remove them
now. The struct btrfs_extent_ref_v0 is not used anywhere, but struct
btrfs_extent_item_v0 is still part of a backward compatibility check in
relocation.c and thus not removed.
Signed-off-by: David Sterba <dsterba@suse.com>
There's no callers in-tree anymore since
commit d24ee97b96 ("btrfs: use new helpers to set uuids in eb")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[BUG]
For the following operation, qgroup is guaranteed to be screwed up due
to snapshot adding to a new qgroup:
# mkfs.btrfs -f $dev
# mount $dev $mnt
# btrfs qgroup en $mnt
# btrfs subv create $mnt/src
# xfs_io -f -c "pwrite 0 1m" $mnt/src/file
# sync
# btrfs qgroup create 1/0 $mnt/src
# btrfs subv snapshot -i 1/0 $mnt/src $mnt/snapshot
# btrfs qgroup show -prce $mnt/src
qgroupid rfer excl max_rfer max_excl parent child
-------- ---- ---- -------- -------- ------ -----
0/5 16.00KiB 16.00KiB none none --- ---
0/257 1.02MiB 16.00KiB none none --- ---
0/258 1.02MiB 16.00KiB none none 1/0 ---
1/0 0.00B 0.00B none none --- 0/258
^^^^^^^^^^^^^^^^^^^^
[CAUSE]
The problem is in btrfs_qgroup_inherit(), we don't have good enough
check to determine if the new relation would break the existing
accounting.
Unlike btrfs_add_qgroup_relation(), which has proper check to determine
if we can do quick update without a rescan, in btrfs_qgroup_inherit() we
can even assign a snapshot to multiple qgroups.
[FIX]
Fix it by manually marking qgroup inconsistent for snapshot inheritance.
For subvolume creation, since all its extents are exclusively owned, we
don't need to rescan.
In theory, we should call relation check like quick_update_accounting()
when doing qgroup inheritance and inform user about qgroup accounting
inconsistency.
But we don't have good mechanism to relay that back to the user in the
snapshot creation context, thus we can only silently mark the qgroup
inconsistent.
Anyway, user shouldn't use qgroup inheritance during snapshot creation,
and should add qgroup relationship after snapshot creation by 'btrfs
qgroup assign', which has a much better UI to inform user about qgroup
inconsistent and kick in rescan automatically.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When mounting, we handle deleted subvolume and orphan items. First,
find add orphan roots, then add them to fs_root radix tree. Second, in
tree-root, process each orphan item, skip if it is dead root.
The original algorithm is based on the list of dead_roots, one by one to
visit and check whether the objectid is consistent, the time complexity
is O (n ^ 2). When processing 50000 deleted subvols, it takes about
120s.
Because btrfs_find_orphan_roots has already ran before us, and added
deleted subvol to fs_roots radix tree.
The fs root will only be removed from the fs_roots radix tree after the
cleaner process is started, and the cleaner will only start execution
after the mount is complete.
btrfs_orphan_cleanup can be called during the whole filesystem mount
lifetime, but only "tree root" will be used in this section of code, and
only mount time will be brought into tree root.
So we can quickly check whether the orphan item is dead root through the
fs_roots radix tree.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Robbie Ko <robbieko@synology.com>
Signed-off-by: David Sterba <dsterba@suse.com>
I've grepped logs for 'errno=.*unknown' and found -95, -117 and -122,
now added to the table. The wording is adjusted so it makes sense in
context of filesystem.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When an old device has new fsid through 'btrfs device add -f <dev>' our
fs_devices list has an alien device in one of the fs_devices lists.
By having an alien device in fs_devices, we have two issues so far
1. missing device does not not show as missing in the userland
2. degraded mount will fail
Both issues are caused by the fact that there's an alien device in the
fs_devices list. (Alien means that it does not belong to the filesystem,
identified by fsid, or does not contain btrfs filesystem at all, eg. due
to overwrite).
A device can be scanned/added through the control device ioctls
SCAN_DEV, DEVICES_READY or by ADD_DEV.
And device coming through the control device is checked against the all
other devices in the lists, but this was not the case for ADD_DEV.
This patch fixes both issues above by removing the alien device.
CC: stable@vger.kernel.org # 5.4+
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
btrfs_free_extra_devids() updates fs_devices::latest_bdev to point to
the bdev with greatest device::generation number. For a typical-missing
device the generation number is zero so fs_devices::latest_bdev will
never point to it.
But if the missing device is due to alienation [1], then
device::generation is not zero and if it is greater or equal to the rest
of device generations in the list, then fs_devices::latest_bdev ends up
pointing to the missing device and reports the error like [2].
[1] We maintain devices of a fsid (as in fs_device::fsid) in the
fs_devices::devices list, a device is considered as an alien device
if its fsid does not match with the fs_device::fsid
Consider a working filesystem with raid1:
$ mkfs.btrfs -f -d raid1 -m raid1 /dev/sda /dev/sdb
$ mount /dev/sda /mnt-raid1
$ umount /mnt-raid1
While mnt-raid1 was unmounted the user force-adds one of its devices to
another btrfs filesystem:
$ mkfs.btrfs -f /dev/sdc
$ mount /dev/sdc /mnt-single
$ btrfs dev add -f /dev/sda /mnt-single
Now the original mnt-raid1 fails to mount in degraded mode, because
fs_devices::latest_bdev is pointing to the alien device.
$ mount -o degraded /dev/sdb /mnt-raid1
[2]
mount: wrong fs type, bad option, bad superblock on /dev/sdb,
missing codepage or helper program, or other error
In some cases useful info is found in syslog - try
dmesg | tail or so.
kernel: BTRFS warning (device sdb): devid 1 uuid 072a0192-675b-4d5a-8640-a5cf2b2c704d is missing
kernel: BTRFS error (device sdb): failed to read devices
kernel: BTRFS error (device sdb): open_ctree failed
Fix the root cause by checking if the device is not missing before it
can be considered for the fs_devices::latest_bdev.
CC: stable@vger.kernel.org # 4.19+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Use crypto_shash_digest() instead of crypto_shash_init() +
crypto_shash_update() + crypto_shash_final(). This is more efficient.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There is no need of goto out in open_fs_devices() as there is nothing
special done there.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
At btrfs_log_prealloc_extents() we are checking if copy_items() returns a
value greater than 0. That used to happen in the past to signal the caller
that the path given to it was released and reused for other searches, but
as of commit 0e56315ca1 ("Btrfs: fix missing hole after hole punching
and fsync when using NO_HOLES"), the copy_items() function does not have
that behaviour anymore and always returns 0 or a negative value. So just
remove that check at btrfs_log_prealloc_extents(), which the previously
mentioned commit forgot to remove.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently, direct I/O has its own versions of bio_readpage_error() and
btrfs_check_repairable() (dio_read_error() and
btrfs_check_dio_repairable(), respectively). The main difference is that
the direct I/O version doesn't do read validation. The rework of direct
I/O repair makes it possible to do validation, so we can get rid of
btrfs_check_dio_repairable() and combine bio_readpage_error() and
dio_read_error() into a new helper, btrfs_submit_read_repair().
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This was originally added in commit 8b110e393c ("Btrfs: implement
repair function when direct read fails") to avoid a deadlock. In that
commit, the direct I/O read endio executes on the endio_workers
workqueue, submits a repair bio, and waits for it to complete. The
repair bio endio must execute on a different workqueue, otherwise it
could block on the endio_workers workqueue becoming available, which
won't happen because the original endio is blocked on the repair bio.
As of the previous commit, the original endio doesn't wait for the
repair bio, so this separate workqueue is unnecessary.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Direct I/O read repair was originally implemented in commit 8b110e393c
("Btrfs: implement repair function when direct read fails"). This
implementation is unnecessarily complicated. There is major code
duplication between __btrfs_subio_endio_read() (checks checksums and
handles I/O errors for files with checksums),
__btrfs_correct_data_nocsum() (handles I/O errors for files without
checksums), btrfs_retry_endio() (checks checksums and handles I/O errors
for retries of files with checksums), and btrfs_retry_endio_nocsum()
(handles I/O errors for retries of files without checksum). If it sounds
like these should be one function, that's because they should.
Additionally, these functions are very hard to follow due to their
excessive use of goto.
This commit replaces the original implementation. After the previous
commit getting rid of orig_bio, we can reuse the same endio callback for
repair I/O and the original I/O, we just need to track the file offset
and original iterator in the repair bio. We can also unify the handling
of files with and without checksums and simplify the control flow. We
also no longer have to wait for each repair I/O to complete one by one.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In the worst case, there are _4_ layers of bios in the Btrfs direct I/O
path:
1. The bio created by the generic direct I/O code (dio_bio).
2. A clone of dio_bio we create in btrfs_submit_direct() to represent
the entire direct I/O range (orig_bio).
3. A partial clone of orig_bio limited to the size of a RAID stripe that
we create in btrfs_submit_direct_hook().
4. Clones of each of those split bios for each RAID stripe that we
create in btrfs_map_bio().
As of the previous commit, the second layer (orig_bio) is no longer
needed for anything: we can split dio_bio instead, and complete dio_bio
directly when all of the cloned bios complete. This lets us clean up a
bunch of cruft, including dip->subio_endio and dip->errors (we can use
dio_bio->bi_status instead). It also enables the next big cleanup of
direct I/O read repair.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The next commit will get rid of btrfs_dio_private->orig_bio. The only
thing we really need it for is containing all of the checksums, but we
can easily put the checksum array in btrfs_dio_private and have the
submitted bios reference the array. We can also look the checksums up
while we're setting up instead of the current awkward logic that looks
them up for orig_bio when the first split bio is submitted.
(Interestingly, btrfs_dio_private did contain the
checksums before commit 23ea8e5a07 ("Btrfs: load checksum data once
when submitting a direct read io"), but it didn't look them up up
front.)
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This is really a reference count now, so convert it to refcount_t and
rename it to refs.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We haven't used this since commit 9be3395bcd ("Btrfs: use a btrfs
bioset instead of abusing bio internals").
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Since its introduction in commit 2fe6303e7c ("Btrfs: split
bio_readpage_error into several functions"), btrfs_check_repairable()
has only been used from extent_io.c where it is defined.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
__readpage_endio_check() is also used from the direct I/O read code, so
give it a more descriptive name.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Fix a couple of issues in the btrfs_lookup_bio_sums documentation:
* The bio doesn't need to be a btrfs_io_bio if dst was provided. Move
the declaration in the code to make that clear, too.
* dst must be large enough to hold nblocks * csum_size, not just
csum_size.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The purpose of the validation step is to distinguish between good and
bad sectors in a failed multi-sector read. If a multi-sector read
succeeded but some of those sectors had checksum errors, we don't need
to validate anything; we know the sectors with bad checksums need to be
repaired.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Read repair does two things: it finds a good copy of data to return to
the reader, and it corrects the bad copy on disk. If a read of multiple
sectors has an I/O error, repair does an extra "validation" step that
issues a separate read for each sector. This allows us to find the exact
failing sectors and only rewrite those.
This heuristic is implemented in
bio_readpage_error()/btrfs_check_repairable() as:
failed_bio_pages = failed_bio->bi_iter.bi_size >> PAGE_SHIFT;
if (failed_bio_pages > 1)
do validation
However, at this point, bi_iter may have already been advanced. This
means that we'll skip the validation step and rewrite the entire failed
read.
Fix it by getting the actual size from the biovec (which we can do
because this is only called for non-cloned bios, although that will
change in a later commit).
Fixes: 8a2ee44a37 ("btrfs: look at bi_size for repair decisions")
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In btrfs_submit_direct(), if we fail to allocate the btrfs_dio_private,
we complete the ordered extent range. However, we don't mark that the
range doesn't need to be cleaned up from btrfs_direct_IO() until later.
Therefore, if we fail to allocate the btrfs_dio_private, we complete the
ordered extent range twice. We could fix this by updating
unsubmitted_oe_range earlier, but it's cleaner to reorganize the code so
that creating the btrfs_dio_private and submitting the bios are
separate, and once the btrfs_dio_private is created, cleanup always
happens through the btrfs_dio_private.
The logic around unsubmitted_oe_range_end and unsubmitted_oe_range_start
is really subtle. We have the following:
1. btrfs_direct_IO sets those two to the same value.
2. When we call __blockdev_direct_IO unless
btrfs_get_blocks_direct->btrfs_get_blocks_direct_write is called to
modify unsubmitted_oe_range_start so that start < end. Cleanup
won't happen.
3. We come into btrfs_submit_direct - if it dip allocation fails we'd
return with oe_range_end now modified so cleanup will happen.
4. If we manage to allocate the dip we reset the unsubmitted range
members to be equal so that cleanup happens from
btrfs_endio_direct_write.
This 4-step logic is not really obvious, especially given it's scattered
across 3 functions.
Fixes: f28a492878 ("Btrfs: fix leaking of ordered extents after direct IO write error")
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
[ add range start/end logic explanation from Nikolay ]
Signed-off-by: David Sterba <dsterba@suse.com>
In btrfs_submit_direct_hook(), if a direct I/O write doesn't span a RAID
stripe or chunk, we submit orig_bio without cloning it. In this case, we
don't increment pending_bios. Then, if btrfs_submit_dio_bio() fails, we
decrement pending_bios to -1, and we never complete orig_bio. Fix it by
initializing pending_bios to 1 instead of incrementing later.
Fixing this exposes another bug: we put orig_bio prematurely and then
put it again from end_io. Fix it by not putting orig_bio.
After this change, pending_bios is really more of a reference count, but
I'll leave that cleanup separate to keep the fix small.
Fixes: e65e153554 ("btrfs: fix panic caused by direct IO")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
At clean_pinned_extents(), whether we end up returning success or failure,
we pretty much have to do the same things:
1) unlock unused_bg_unpin_mutex
2) decrement reference count on the previous transaction
We also call btrfs_dec_block_group_ro() in case of failure, but that is
better done in its caller, btrfs_delete_unused_bgs(), since its the
caller that calls inc_block_group_ro(), so it should be responsible for
the decrement operation, as it is in case any of the other functions it
calls fail.
So move the call to btrfs_dec_block_group_ro() from clean_pinned_extents()
into btrfs_delete_unused_bgs() and unify the error and success return
paths for clean_pinned_extents(), reducing duplicated code and making it
simpler.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
All callers pass the eb::level so we can get read it directly inside the
btrfs_bin_search and key_search.
This is inspired by the work of Marek in U-boot.
CC: Marek Behun <marek.behun@nic.cz>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Instead of returning both the page and the super block structure, make
btrfs_read_disk_super just return a pointer to struct btrfs_disk_super.
As a result the function signature is simplified. Also,
read_cache_page_gfp can never return NULL so check its return value only
for IS_ERR.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The function always works on a local copy of the reloc root list, which
cannot be modified outside of it so using list_for_each_entry is fine.
Additionally the macro handles empty lists so drop list_empty checks of
callers. No semantic changes.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Deleting a subvolume on a full filesystem leads to ENOSPC followed by a
forced read-only. This is not a transaction abort and the filesystem is
otherwise ok, so the error should be just propagated to the callers.
This is caused by unnecessary call to btrfs_handle_fs_error for all
errors, except EAGAIN. This does not make sense as the standard
transaction abort mechanism is in btrfs_drop_snapshot so all relevant
failures are handled.
Originally in commit cb1b69f450 ("Btrfs: forced readonly when
btrfs_drop_snapshot() fails") there was no return value at all, so the
btrfs_std_error made some sense but once the error handling and
propagation has been implemented we don't need it anymore.
Signed-off-by: David Sterba <dsterba@suse.com>
The reclaim_size counter of a space_info object is unsigned. So its value
can never be negative, it's pointless to have an assertion that checks
its value is >= 0, therefore remove it.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Remove the duplicate definition of 'inode_item_err' in the file
tree-checker.c that got there by accident in c23c77b097 ("btrfs:
tree-checker: Refactor inode key check into seperate function").
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Zheng Wei <wei.zheng@vivo.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Nikolay noticed a bunch of test failures with my global rsv steal
patches. At first he thought they were introduced by them, but they've
been failing for a while with 64k nodes.
The problem is with 64k nodes we have a global reserve that calculates
out to 13MiB on a freshly made file system, which only has 8MiB of
metadata space. Because of changes I previously made we no longer
account for the global reserve in the overcommit logic, which means we
correctly allow overcommit to happen even though we are already
overcommitted.
However in some corner cases, for example btrfs/170, we will allocate
the entire file system up with data chunks before we have enough space
pressure to allocate a metadata chunk. Then once the fs is full we
ENOSPC out because we cannot overcommit and the global reserve is taking
up all of the available space.
The most ideal way to deal with this is to change our space reservation
stuff to take into account the height of the tree's that we're
modifying, so that our global reserve calculation does not end up so
obscenely large.
However that is a huge undertaking. Instead fix this by forcing a chunk
allocation if the global reserve is larger than the total metadata
space. This gives us essentially the same behavior that happened
before, we get a chunk allocated and these tests can pass.
This is meant to be a stop-gap measure until we can tackle the "tree
height only" project.
Fixes: 0096420adb ("btrfs: do not account global reserve in can_overcommit")
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Tested-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
With normal tickets we could have a large reservation at the front of
the list that is unable to be satisfied, but a smaller ticket later on
that can be satisfied. The way we handle this is to run
btrfs_try_granting_tickets() in maybe_fail_all_tickets().
However no such protection exists for priority tickets. Fix this by
handling it in handle_reserve_ticket(). If we've returned after
attempting to flush space in a priority related way, we'll still be on
the priority list and need to be removed.
We rely on the flushing to free up space and wake the ticket, but if
there is not enough space to reclaim _but_ there's enough space in the
space_info to handle subsequent reservations then we would have gotten
an ENOSPC erroneously.
Address this by catching where we are still on the list, meaning we were
a priority ticket, and removing ourselves and then running
btrfs_try_granting_tickets(). This will handle this particular corner
case.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Tested-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In debugging a generic/320 failure on ppc64, Nikolay noticed that
sometimes we'd ENOSPC out with plenty of space to reclaim if we had
committed the transaction. He further discovered that this was because
there was a priority ticket that was small enough to fit in the free
space currently in the space_info.
Consider the following scenario. There is no more space to reclaim in
the fs without committing the transaction. Assume there's 1MiB of space
free in the space info, but there are pending normal tickets with 2MiB
reservations.
Now a priority ticket comes in with a .5MiB reservation. Because we
have normal tickets pending we add ourselves to the priority list,
despite the fact that we could satisfy this reservation.
The flushing machinery now gets to the point where it wants to commit
the transaction, but because there's a .5MiB ticket on the priority list
and we have 1MiB of free space we assume the ticket will be granted
soon, so we bail without committing the transaction.
Meanwhile the priority flushing does not commit the transaction, and
eventually fails with an ENOSPC. Then all other tickets are failed with
ENOSPC because we were never able to actually commit the transaction.
The fix for this is we should have simply granted the priority flusher
his reservation, because there was space to make the reservation.
Priority flushers by definition take priority, so they are allowed to
make their reservations before any previous normal tickets. By not
adding this priority ticket to the list the normal flushing mechanisms
will then commit the transaction and everything will continue normally.
We still need to serialize ourselves with other priority tickets, so if
there are any tickets on the priority list then we need to add ourselves
to that list in order to maintain the serialization between priority
tickets.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Tested-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
On ppc64le with 64k page size (respectively 64k block size) generic/320
was failing and debug output showed we were getting a premature ENOSPC
with a bunch of space in btrfs_fs_info::trans_block_rsv.
This meant there were still open transaction handles holding space, yet
the flusher didn't commit the transaction because it deemed the freed
space won't be enough to satisfy the current reserve ticket. Fix this
by accounting for space in trans_block_rsv when deciding whether the
current transaction should be committed or not.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Tested-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We previously had a limit of stealing 50% of the global reserve for
unlink. This was from a time when the global reserve was used for the
delayed refs as well. However now those reservations are kept separate,
so the global reserve can be depleted much more to allow us to make
progress for space restoring operations like unlink. Change the minimum
amount of space required to be left in the global reserve to 10%.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Tested-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
For unlink transactions and block group removal
btrfs_start_transaction_fallback_global_rsv will first try to start an
ordinary transaction and if it fails it will fall back to reserving the
required amount by stealing from the global reserve. This is problematic
because of all the same reasons we had with previous iterations of the
ENOSPC handling, thundering herd. We get a bunch of failures all at
once, everybody tries to allocate from the global reserve, some win and
some lose, we get an ENSOPC.
Fix this behavior by introducing BTRFS_RESERVE_FLUSH_ALL_STEAL. It's
used to mark unlink reservation. To fix this we need to integrate this
logic into the normal ENOSPC infrastructure. We still go through all of
the normal flushing work, and at the moment we begin to fail all the
tickets we try to satisfy any tickets that are allowed to steal by
stealing from the global reserve. If this works we start the flushing
system over again just like we would with a normal ticket satisfaction.
This serializes our global reserve stealing, so we don't have the
thundering herd problem.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Tested-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
For relocation tree detection, relocation backref cache uses
btrfs_should_ignore_reloc_root() which uses relocation-specific checks
like checking the DEAD_RELOC_ROOT bit.
However for general purpose backref cache, we can rely on that check, as
it's possible that relocation is also running.
For generic purposed backref cache, we detect reloc root by
SHARED_BLOCK_REF item. Only reloc root node has its parent bytenr
pointing back to itself.
And in that case, backref cache will mark the reloc root node useless,
dropping any child orphan nodes.
So only call btrfs_should_ignore_reloc_root() if the backref cache is
for relocation.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The error cleanup will be extracted as a new function,
btrfs_backref_error_cleanup(), and moved to backref.c and exported for
later usage.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This the the 2nd major part of generic backref cache. Move it to
backref.c so we can reuse it.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This function is the major part of backref cache build process, move it
to backref.c so we can reuse it later.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The backref code is going to be moved to backref.c, and read_fs_root()
is just a simple wrapper, open-code it to prepare to the incoming code
move.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This function is mostly single purpose to relocation backref cache, but
since we're moving the main part of backref cache to backref.c, we need
to export such function.
And to avoid confusion, rename the function to
btrfs_should_ignore_reloc_root() make the name a little more clear.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Also change the parameter, since all callers can easily grab an fs_info,
there is no need for all the pointer chasing.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Since we're releasing all existing nodes/edges, other than cleanup the
mess after error, "release" is a more proper naming here.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Also add comment explaining the cleanup progress, to differ it from
btrfs_backref_drop_node().
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
With extra comment for drop_backref_node() as it has some similarity
with remove_backref_node(), thus we need extra comment explaining the
difference.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Structure tree_entry provides a very simple rb_tree which only uses
bytenr as search index.
That tree_entry is used in 3 structures: backref_node, mapping_node and
tree_block.
Since we're going to make backref_node independnt from relocation, it's
a good time to extract the tree_entry into rb_simple_node, and export it
into misc.h.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
These 3 structures are the main part of btrfs backref cache, move them
to backref.h to build the basis for later reuse.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Those three structures are the main elements of backref cache. Add the
"btrfs_" prefix for later export.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This patch will also add some comment for the cleanup.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
After handle_one_tree_backref(), all newly added (not cached) edges and
nodes have the following features:
- Only backref_edge::list[LOWER] is linked.
This means, we can only iterate from botton to top, not the other
direction.
- Newly added nodes are not added to cache rb_tree yet
So to finish the backref cache, we still need to finish the links and
add all nodes into backref cache rb_tree.
This patch will refactor the existing code into finish_upper_links(),
add more comments of each branch, and why we need to do all the work.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
build_backref_tree() uses "goto again;" to implement a breadth-first
search to build backref cache.
This patch will extract most of its work into a wrapper,
handle_one_tree_block(), and use a do {} while() loop to implement the
same thing.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Bytenr and level are essential parameters for backref_node, thus it
makes sense to initialize them at allocation time.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Since backref_edge is used to connect upper and lower backref nodes, and
needs to access both nodes, some code can look pretty nasty:
list_add_tail(&edge->list[LOWER], &cur->upper);
The above code will link @cur to the LOWER side of the edge, while both
"LOWER" and "upper" words show up. This can sometimes be very confusing
for reader to grasp.
This patch introduces a new wrapper, link_backref_edge(), to handle the
linking behavior. Which also has extra ASSERT() to ensure caller won't
pass wrong nodes.
Also, this updates the comment of related lists of backref_node and
backref_edge, to make it more clear that each list points to what.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The processing of indirect tree backref (TREE_BLOCK_REF) is the most
complex work.
We need to grab the fs root, do a tree search to locate all its parent
nodes, link all needed edges, and put all uncached edges to pending edge
list.
This is definitely worth a helper function.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
For BTRFS_SHARED_BLOCK_REF_KEY, its processing is straightforward, as we
now the parent node bytenr directly.
If the parent is already cached, or a root, call it a day.
If the parent is not cached, add it pending list.
This patch will just refactor this part into its own function,
handle_direct_tree_backref() and add some comment explaining the
@ref_key parameter.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
find_reloc_root() searches reloc_control::reloc_root_tree to find the
reloc root. This behavior is only useful for relocation backref cache.
For the incoming more generic purpose backref cache, we don't care
about who owns the reloc root, but only care if it's a reloc root.
So this patch makes the following modifications to make the reloc root
search more specific to relocation backref:
- Add backref_node::is_reloc_root
This will be an extra indicator for generic purposed backref cache.
User doesn't need to read root key from backref_node::root to
determine if it's a reloc root.
Also for reloc tree root, it's useless and will be queued to useless
list.
- Add backref_cache::is_reloc
This will allow backref cache code to do different behavior for
generic purpose backref cache and relocation backref cache.
- Pass fs_info to find_reloc_root()
- Export find_reloc_root()
So backref.c can utilize this function.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Add this member so that we can grab fs_info without the help from
reloc_control.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
These two new members will act the same as the existing local lists,
@useless and @list in build_backref_tree().
Currently build_backref_tree() is only executed serially, thus moving
such local list into backref_cache is still safe.
Also since we're here, use list_first_entry() to replace a lot of
list_entry() calls after !list_empty().
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
These two functions are weirdly named, mark_block_processed() in fact
just marks a range dirty unconditionally, while __mark_block_processed()
does extra check before doing the marking.
This patch will open code old mark_block_processed, and rename
__mark_block_processed() to remove the "__" prefix.
Since we're here, also kill the forward declaration, which could also
kill in_block_group() with in_range() macro.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In the core function of relocation, build_backref_tree, it needs to
iterate all backref items of one tree block.
Use btrfs_backref_iter infrastructure to do the loop and make the code
more readable.
The backref items look would be much more easier to read:
ret = btrfs_backref_iter_start(iter, cur->bytenr);
for (; ret == 0; ret = btrfs_backref_iter_next(iter)) {
/* The really important work */
}
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This function will go to the next inline/keyed backref for
btrfs_backref_iter infrastructure.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Due to the complex nature of btrfs extent tree, when we want to iterate
all backrefs of one extent, this involves quite a lot of work, like
searching the EXTENT_ITEM/METADATA_ITEM, iteration through inline and keyed
backrefs.
Normally this would result in a complex code, something like:
btrfs_search_slot()
/* Ensure we are at EXTENT_ITEM/METADATA_ITEM */
while (1) { /* Loop for extent tree items */
while (ptr < end) { /* Loop for inlined items */
/* Real work here */
}
next:
ret = btrfs_next_item()
/* Ensure we're still at keyed item for specified bytenr */
}
The idea of btrfs_backref_iter is to avoid such complex and hard to
read code structure, but something like the following:
iter = btrfs_backref_iter_alloc();
ret = btrfs_backref_iter_start(iter, bytenr);
if (ret < 0)
goto out;
for (; ; ret = btrfs_backref_iter_next(iter)) {
/* Real work here */
}
out:
btrfs_backref_iter_free(iter);
This patch is just the skeleton + btrfs_backref_iter_start() code.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Sparse reports a warning at btrfs_tree_lock()
warning: context imbalance in btrfs_tree_lock() - wrong count at exit
The root cause is the missing annotation at btrfs_tree_lock()
Add the missing __acquires(&eb->lock) annotation
Signed-off-by: Jules Irenge <jbi.octave@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Sparse reports a warning at btrfs_lock_cluster()
warning: context imbalance in btrfs_lock_cluster()
- wrong count
The root cause is the missing annotation at btrfs_lock_cluster()
Add the missing __acquires(&cluster->refill_lock) annotation.
Signed-off-by: Jules Irenge <jbi.octave@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Some older compilers like gcc-4.8 warn about mismatched curly braces in
a initializer:
fs/btrfs/backref.c: In function 'is_shared_data_backref':
fs/btrfs/backref.c:394:9: error: missing braces around
initializer [-Werror=missing-braces]
struct prelim_ref target = {0};
^
fs/btrfs/backref.c:394:9: error: (near initialization for
'target.rbnode') [-Werror=missing-braces]
Use the GNU empty initializer extension to avoid this.
Fixes: ed58f2e66e ("btrfs: backref, don't add refs from shared block when resolving normal backref")
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[BUG]
One run of btrfs/063 triggered the following lockdep warning:
============================================
WARNING: possible recursive locking detected
5.6.0-rc7-custom+ #48 Not tainted
--------------------------------------------
kworker/u24:0/7 is trying to acquire lock:
ffff88817d3a46e0 (sb_internal#2){.+.+}, at: start_transaction+0x66c/0x890 [btrfs]
but task is already holding lock:
ffff88817d3a46e0 (sb_internal#2){.+.+}, at: start_transaction+0x66c/0x890 [btrfs]
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(sb_internal#2);
lock(sb_internal#2);
*** DEADLOCK ***
May be due to missing lock nesting notation
4 locks held by kworker/u24:0/7:
#0: ffff88817b495948 ((wq_completion)btrfs-endio-write){+.+.}, at: process_one_work+0x557/0xb80
#1: ffff888189ea7db8 ((work_completion)(&work->normal_work)){+.+.}, at: process_one_work+0x557/0xb80
#2: ffff88817d3a46e0 (sb_internal#2){.+.+}, at: start_transaction+0x66c/0x890 [btrfs]
#3: ffff888174ca4da8 (&fs_info->reloc_mutex){+.+.}, at: btrfs_record_root_in_trans+0x83/0xd0 [btrfs]
stack backtrace:
CPU: 0 PID: 7 Comm: kworker/u24:0 Not tainted 5.6.0-rc7-custom+ #48
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
Workqueue: btrfs-endio-write btrfs_work_helper [btrfs]
Call Trace:
dump_stack+0xc2/0x11a
__lock_acquire.cold+0xce/0x214
lock_acquire+0xe6/0x210
__sb_start_write+0x14e/0x290
start_transaction+0x66c/0x890 [btrfs]
btrfs_join_transaction+0x1d/0x20 [btrfs]
find_free_extent+0x1504/0x1a50 [btrfs]
btrfs_reserve_extent+0xd5/0x1f0 [btrfs]
btrfs_alloc_tree_block+0x1ac/0x570 [btrfs]
btrfs_copy_root+0x213/0x580 [btrfs]
create_reloc_root+0x3bd/0x470 [btrfs]
btrfs_init_reloc_root+0x2d2/0x310 [btrfs]
record_root_in_trans+0x191/0x1d0 [btrfs]
btrfs_record_root_in_trans+0x90/0xd0 [btrfs]
start_transaction+0x16e/0x890 [btrfs]
btrfs_join_transaction+0x1d/0x20 [btrfs]
btrfs_finish_ordered_io+0x55d/0xcd0 [btrfs]
finish_ordered_fn+0x15/0x20 [btrfs]
btrfs_work_helper+0x116/0x9a0 [btrfs]
process_one_work+0x632/0xb80
worker_thread+0x80/0x690
kthread+0x1a3/0x1f0
ret_from_fork+0x27/0x50
It's pretty hard to reproduce, only one hit so far.
[CAUSE]
This is because we're calling btrfs_join_transaction() without re-using
the current running one:
btrfs_finish_ordered_io()
|- btrfs_join_transaction() <<< Call #1
|- btrfs_record_root_in_trans()
|- btrfs_reserve_extent()
|- btrfs_join_transaction() <<< Call #2
Normally such btrfs_join_transaction() call should re-use the existing
one, without trying to re-start a transaction.
But the problem is, in btrfs_join_transaction() call #1, we call
btrfs_record_root_in_trans() before initializing current::journal_info.
And in btrfs_join_transaction() call #2, we're relying on
current::journal_info to avoid such deadlock.
[FIX]
Call btrfs_record_root_in_trans() after we have initialized
current::journal_info.
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When we have an inode with a prealloc extent that starts at an offset
lower than the i_size and there is another prealloc extent that starts at
an offset beyond i_size, we can end up losing part of the first prealloc
extent (the part that starts at i_size) and have an implicit hole if we
fsync the file and then have a power failure.
Consider the following example with comments explaining how and why it
happens.
$ mkfs.btrfs -f /dev/sdb
$ mount /dev/sdb /mnt
# Create our test file with 2 consecutive prealloc extents, each with a
# size of 128Kb, and covering the range from 0 to 256Kb, with a file
# size of 0.
$ xfs_io -f -c "falloc -k 0 128K" /mnt/foo
$ xfs_io -c "falloc -k 128K 128K" /mnt/foo
# Fsync the file to record both extents in the log tree.
$ xfs_io -c "fsync" /mnt/foo
# Now do a redudant extent allocation for the range from 0 to 64Kb.
# This will merely increase the file size from 0 to 64Kb. Instead we
# could also do a truncate to set the file size to 64Kb.
$ xfs_io -c "falloc 0 64K" /mnt/foo
# Fsync the file, so we update the inode item in the log tree with the
# new file size (64Kb). This also ends up setting the number of bytes
# for the first prealloc extent to 64Kb. This is done by the truncation
# at btrfs_log_prealloc_extents().
# This means that if a power failure happens after this, a write into
# the file range 64Kb to 128Kb will not use the prealloc extent and
# will result in allocation of a new extent.
$ xfs_io -c "fsync" /mnt/foo
# Now set the file size to 256K with a truncate and then fsync the file.
# Since no changes happened to the extents, the fsync only updates the
# i_size in the inode item at the log tree. This results in an implicit
# hole for the file range from 64Kb to 128Kb, something which fsck will
# complain when not using the NO_HOLES feature if we replay the log
# after a power failure.
$ xfs_io -c "truncate 256K" -c "fsync" /mnt/foo
So instead of always truncating the log to the inode's current i_size at
btrfs_log_prealloc_extents(), check first if there's a prealloc extent
that starts at an offset lower than the i_size and with a length that
crosses the i_size - if there is one, just make sure we truncate to a
size that corresponds to the end offset of that prealloc extent, so
that we don't lose the part of that extent that starts at i_size if a
power failure happens.
A test case for fstests follows soon.
Fixes: 31d11b83b9 ("Btrfs: fix duplicate extents after fsync of file with prealloc extents")
CC: stable@vger.kernel.org # 4.14+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
btrfs_recover_relocation() invokes btrfs_join_transaction(), which joins
a btrfs_trans_handle object into transactions and returns a reference of
it with increased refcount to "trans".
When btrfs_recover_relocation() returns, "trans" becomes invalid, so the
refcount should be decreased to keep refcount balanced.
The reference counting issue happens in one exception handling path of
btrfs_recover_relocation(). When read_fs_root() failed, the refcnt
increased by btrfs_join_transaction() is not decreased, causing a refcnt
leak.
Fix this issue by calling btrfs_end_transaction() on this error path
when read_fs_root() failed.
Fixes: 79787eaab4 ("btrfs: replace many BUG_ONs with proper error handling")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
btrfs_remove_block_group() invokes btrfs_lookup_block_group(), which
returns a local reference of the block group that contains the given
bytenr to "block_group" with increased refcount.
When btrfs_remove_block_group() returns, "block_group" becomes invalid,
so the refcount should be decreased to keep refcount balanced.
The reference counting issue happens in several exception handling paths
of btrfs_remove_block_group(). When those error scenarios occur such as
btrfs_alloc_path() returns NULL, the function forgets to decrease its
refcnt increased by btrfs_lookup_block_group() and will cause a refcnt
leak.
Fix this issue by jumping to "out_put_group" label and calling
btrfs_put_block_group() when those error scenarios occur.
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Dave reported a problem where we were panicing with generic/475 with
misc-5.7. This is because we were doing IO after we had stopped all of
the worker threads, because we do the log tree cleanup on roots at drop
time. Cleaning up the log tree will always need to do reads if we
happened to have evicted the blocks from memory.
Because of this simply add a helper to btrfs_cleanup_transaction() that
will go through and drop all of the log roots. This gets run before we
do the close_ctree() work, and thus we are allowed to do any reads that
we would need. I ran this through many iterations of generic/475 with
constrained memory and I did not see the issue.
general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b6b6b: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI
CPU: 2 PID: 12359 Comm: umount Tainted: G W 5.6.0-rc7-btrfs-next-58 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
RIP: 0010:btrfs_queue_work+0x33/0x1c0 [btrfs]
RSP: 0018:ffff9cfb015937d8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8eb5e339ed80 RCX: 0000000000000000
RDX: 0000000000000001 RSI: ffff8eb5eb33b770 RDI: ffff8eb5e37a0460
RBP: ffff8eb5eb33b770 R08: 000000000000020c R09: ffffffff9fc09ac0
R10: 0000000000000007 R11: 0000000000000000 R12: 6b6b6b6b6b6b6b6b
R13: ffff9cfb00229040 R14: 0000000000000008 R15: ffff8eb5d3868000
FS: 00007f167ea022c0(0000) GS:ffff8eb5fae00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f167e5e0cb1 CR3: 0000000138c18004 CR4: 00000000003606e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
btrfs_end_bio+0x81/0x130 [btrfs]
__split_and_process_bio+0xaf/0x4e0 [dm_mod]
? percpu_counter_add_batch+0xa3/0x120
dm_process_bio+0x98/0x290 [dm_mod]
? generic_make_request+0xfb/0x410
dm_make_request+0x4d/0x120 [dm_mod]
? generic_make_request+0xfb/0x410
generic_make_request+0x12a/0x410
? submit_bio+0x38/0x160
submit_bio+0x38/0x160
? percpu_counter_add_batch+0xa3/0x120
btrfs_map_bio+0x289/0x570 [btrfs]
? kmem_cache_alloc+0x24d/0x300
btree_submit_bio_hook+0x79/0xc0 [btrfs]
submit_one_bio+0x31/0x50 [btrfs]
read_extent_buffer_pages+0x2fe/0x450 [btrfs]
btree_read_extent_buffer_pages+0x7e/0x170 [btrfs]
walk_down_log_tree+0x343/0x690 [btrfs]
? walk_log_tree+0x3d/0x380 [btrfs]
walk_log_tree+0xf7/0x380 [btrfs]
? plist_requeue+0xf0/0xf0
? delete_node+0x4b/0x230
free_log_tree+0x4c/0x130 [btrfs]
? wait_log_commit+0x140/0x140 [btrfs]
btrfs_free_log+0x17/0x30 [btrfs]
btrfs_drop_and_free_fs_root+0xb0/0xd0 [btrfs]
btrfs_free_fs_roots+0x10c/0x190 [btrfs]
? do_raw_spin_unlock+0x49/0xc0
? _raw_spin_unlock+0x29/0x40
? release_extent_buffer+0x121/0x170 [btrfs]
close_ctree+0x289/0x2e6 [btrfs]
generic_shutdown_super+0x6c/0x110
kill_anon_super+0xe/0x30
btrfs_kill_super+0x12/0x20 [btrfs]
deactivate_locked_super+0x3a/0x70
Reported-by: David Sterba <dsterba@suse.com>
Fixes: 8c38938c7b ("btrfs: move the root freeing stuff into btrfs_put_root")
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When cleaning pinned extents right before deleting an unused block group,
we check if there's still a previous transaction running and if so we
increment its reference count before using it for cleaning pinned ranges
in its pinned extents iotree. However we ended up never decrementing the
reference count after using the transaction, resulting in a memory leak.
Fix it by decrementing the reference count.
Fixes: fe119a6eeb ("btrfs: switch to per-transaction pinned extents")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This patch corrects the SPDX License Identifier style in header file
related to Btrfs File System support. For C header files
Documentation/process/license-rules.rst mandates C-like comments
(opposed to C source files where C++ style should be used).
Changes made by using a script provided by Joe Perches here:
https://lkml.org/lkml/2019/2/7/46.
Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Nishad Kamdar <nishadkamdar@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
I made a mistake with my previous fix, I assumed that we didn't need to
mess with the reloc roots once we were out of the part of relocation where
we are actually moving the extents.
The subtle thing that I missed is that btrfs_init_reloc_root() also
updates the last_trans for the reloc root when we do
btrfs_record_root_in_trans() for the corresponding fs_root. I've added a
comment to make sure future me doesn't make this mistake again.
This showed up as a WARN_ON() in btrfs_copy_root() because our
last_trans didn't == the current transid. This could happen if we
snapshotted a fs root with a reloc root after we set
rc->create_reloc_tree = 0, but before we actually merge the reloc root.
Worth mentioning that the regression produced the following warning
when running snapshot creation and balance in parallel:
BTRFS info (device sdc): relocating block group 30408704 flags metadata|dup
------------[ cut here ]------------
WARNING: CPU: 0 PID: 12823 at fs/btrfs/ctree.c:191 btrfs_copy_root+0x26f/0x430 [btrfs]
CPU: 0 PID: 12823 Comm: btrfs Tainted: G W 5.6.0-rc7-btrfs-next-58 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
RIP: 0010:btrfs_copy_root+0x26f/0x430 [btrfs]
RSP: 0018:ffffb96e044279b8 EFLAGS: 00010202
RAX: 0000000000000009 RBX: ffff9da70bf61000 RCX: ffffb96e04427a48
RDX: ffff9da733a770c8 RSI: ffff9da70bf61000 RDI: ffff9da694163818
RBP: ffff9da733a770c8 R08: fffffffffffffff8 R09: 0000000000000002
R10: ffffb96e044279a0 R11: 0000000000000000 R12: ffff9da694163818
R13: fffffffffffffff8 R14: ffff9da6d2512000 R15: ffff9da714cdac00
FS: 00007fdeacf328c0(0000) GS:ffff9da735e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055a2a5b8a118 CR3: 00000001eed78002 CR4: 00000000003606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
? create_reloc_root+0x49/0x2b0 [btrfs]
? kmem_cache_alloc_trace+0xe5/0x200
create_reloc_root+0x8b/0x2b0 [btrfs]
btrfs_reloc_post_snapshot+0x96/0x5b0 [btrfs]
create_pending_snapshot+0x610/0x1010 [btrfs]
create_pending_snapshots+0xa8/0xd0 [btrfs]
btrfs_commit_transaction+0x4c7/0xc50 [btrfs]
? btrfs_mksubvol+0x3cd/0x560 [btrfs]
btrfs_mksubvol+0x455/0x560 [btrfs]
__btrfs_ioctl_snap_create+0x15f/0x190 [btrfs]
btrfs_ioctl_snap_create_v2+0xa4/0xf0 [btrfs]
? mem_cgroup_commit_charge+0x6e/0x540
btrfs_ioctl+0x12d8/0x3760 [btrfs]
? do_raw_spin_unlock+0x49/0xc0
? _raw_spin_unlock+0x29/0x40
? __handle_mm_fault+0x11b3/0x14b0
? ksys_ioctl+0x92/0xb0
ksys_ioctl+0x92/0xb0
? trace_hardirqs_off_thunk+0x1a/0x1c
__x64_sys_ioctl+0x16/0x20
do_syscall_64+0x5c/0x280
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7fdeabd3bdd7
Fixes: 2abc726ab4 ("btrfs: do not init a reloc root if we aren't relocating")
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Whenever we add a ticket to a space_info object we increment the object's
reclaim_size counter witht the ticket's bytes, and we decrement it with
the corresponding amount only when we are able to grant the requested
space to the ticket. When we are not able to grant the space to a ticket,
or when the ticket is removed due to a signal (e.g. an application has
received sigterm from the terminal) we never decrement the counter with
the corresponding bytes from the ticket. This leak can result in the
space reclaim code to later do much more work than necessary. So fix it
by decrementing the counter when those two cases happen as well.
Fixes: db161806dc ("btrfs: account ticket size at add/delete time")
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This is a revert of commit 0a8068a3dd ("btrfs: make ranged full
fsyncs more efficient"), with updated comment in btrfs_sync_file.
Commit 0a8068a3dd ("btrfs: make ranged full fsyncs more efficient")
made full fsyncs operate on the given range only as it assumed it was safe
when using the NO_HOLES feature, since the hole detection was simplified
some time ago and no longer was a source for races with ordered extent
completion of adjacent file ranges.
However it's still not safe to have a full fsync only operate on the given
range, because extent maps for new extents might not be present in memory
due to inode eviction or extent cloning. Consider the following example:
1) We are currently at transaction N;
2) We write to the file range [0, 1MiB);
3) Writeback finishes for the whole range and ordered extents complete,
while we are still at transaction N;
4) The inode is evicted;
5) We open the file for writing, causing the inode to be loaded to
memory again, which sets the 'full sync' bit on its flags. At this
point the inode's list of modified extent maps is empty (figuring
out which extents were created in the current transaction and were
not yet logged by an fsync is expensive, that's why we set the
'full sync' bit when loading an inode);
6) We write to the file range [512KiB, 768KiB);
7) We do a ranged fsync (such as msync()) for file range [512KiB, 768KiB).
This correctly flushes this range and logs its extent into the log
tree. When the writeback started an extent map for range [512KiB, 768KiB)
was added to the inode's list of modified extents, and when the fsync()
finishes logging it removes that extent map from the list of modified
extent maps. This fsync also clears the 'full sync' bit;
8) We do a regular fsync() (full ranged). This fsync() ends up doing
nothing because the inode's list of modified extents is empty and
no other changes happened since the previous ranged fsync(), so
it just returns success (0) and we end up never logging extents for
the file ranges [0, 512KiB) and [768KiB, 1MiB).
Another scenario where this can happen is if we replace steps 2 to 4 with
cloning from another file into our test file, as that sets the 'full sync'
bit in our inode's flags and does not populate its list of modified extent
maps.
This was causing test case generic/457 to fail sporadically when using the
NO_HOLES feature, as it exercised this later case where the inode has the
'full sync' bit set and has no extent maps in memory to represent the new
extents due to extent cloning.
Fix this by reverting commit 0a8068a3dd ("btrfs: make ranged full fsyncs
more efficient") since there is no easy way to work around it.
Fixes: 0a8068a3dd ("btrfs: make ranged full fsyncs more efficient")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When not using the NO_HOLES feature we were not marking the destination's
file range as written after cloning an inline extent into it. This can
lead to a data loss if the current destination file size is smaller than
the source file's size.
Example:
$ mkfs.btrfs -f -O ^no-holes /dev/sdc
$ mount /mnt/sdc /mnt
$ echo "hello world" > /mnt/foo
$ cp --reflink=always /mnt/foo /mnt/bar
$ rm -f /mnt/foo
$ umount /mnt
$ mount /mnt/sdc /mnt
$ cat /mnt/bar
$
$ stat -c %s /mnt/bar
0
# -> the file is empty, since we deleted foo, the data lost is forever
Fix that by calling btrfs_inode_set_file_extent_range() after cloning an
inline extent.
A test case for fstests will follow soon.
Link: https://lore.kernel.org/linux-btrfs/20200404193846.GA432065@latitude/
Reported-by: Johannes Hirte <johannes.hirte@datenkhaos.de>
Fixes: 9ddc959e80 ("btrfs: use the file extent tree infrastructure")
Tested-by: Johannes Hirte <johannes.hirte@datenkhaos.de>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Previously we would set the reloc root's last snapshot to transid - 1.
However there was a problem with doing this, and we changed it to
setting the last snapshot to the generation of the commit node of the fs
root.
This however broke should_ignore_root(). The assumption is that if we
are in a generation newer than when the reloc root was created, then we
would find the reloc root through normal backref lookups, and thus can
ignore any fs roots we find with an old enough reloc root.
Now that the last snapshot could be considerably further in the past
than before, we'd end up incorrectly ignoring an fs root. Thus we'd
find no nodes for the bytenr we were searching for, and we'd fail to
relocate anything. We'd loop through the relocate code again and see
that there were still used space in that block group, attempt to
relocate those bytenr's again, fail in the same way, and just loop like
this forever. This is tricky in that we have to not modify the fs root
at all during this time, so we need to have a block group that has data
in this fs root that is not shared by any other root, which is why this
has been difficult to reproduce.
Fixes: 054570a1dc ("Btrfs: fix relocation incorrectly dropping data references")
CC: stable@vger.kernel.org # 4.9+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Ordered ops are started twice in sync file, once outside of inode mutex
and once inside, taking the dio semaphore. There was one error path
missing the semaphore unlock.
Fixes: aab15e8ec2 ("Btrfs: fix rare chances for data loss when doing a fast fsync")
CC: stable@vger.kernel.org # 4.19+
Signed-off-by: Robbie Ko <robbieko@synology.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
[ add changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
snprintf() is a hard-to-use function, and it's especially difficult to
use it properly for concatenating substrings in a buffer with a limited
size. Since snprintf() returns the would-be-output size, not the actual
size, the subsequent use of snprintf() may point to the incorrect
position easily. Also, returning the value from snprintf() directly to
sysfs show function would pass a bogus value that is higher than the
actually truncated string.
That said, although the current code doesn't actually overflow the
buffer with PAGE_SIZE, it's a usage that shouldn't be done. Or it's
worse; this gives a wrong confidence as if it were doing safe
operations.
This patch replaces such snprintf() calls with a safer version,
scnprintf(). It returns the actual output size, hence it's more
intuitive and the code does what's expected.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Zygo reported a deadlock where a task was stuck in the inode logical
resolve code. The deadlock looks like this
Task 1
btrfs_ioctl_logical_to_ino
->iterate_inodes_from_logical
->iterate_extent_inodes
->path->search_commit_root isn't set, so a transaction is started
->resolve_indirect_ref for a root that's being deleted
->search for our key, attempt to lock a node, DEADLOCK
Task 2
btrfs_drop_snapshot
->walk down to a leaf, lock it, walk up, lock node
->end transaction
->start transaction
-> wait_cur_trans
Task 3
btrfs_commit_transaction
->wait_event(cur_trans->write_wait, num_writers == 1) DEADLOCK
We are holding a transaction open in btrfs_ioctl_logical_to_ino while we
try to resolve our references. btrfs_drop_snapshot() holds onto its
locks while it stops and starts transaction handles, because it assumes
nobody is going to touch the root now. Commit just does what commit
does, waiting for the writers to finish, blocking any new trans handles
from starting.
Fix this by making the backref code not try to resolve backrefs of roots
that are currently being deleted. This will keep us from walking into a
snapshot that's currently being deleted.
This problem was harder to hit before because we rarely broke out of the
snapshot delete halfway through, but with my delayed ref throttling code
it happened much more often. However we've always been able to do this,
so it's not a new problem.
Fixes: 8da6d5815c ("Btrfs: added btrfs_find_all_roots()")
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We always search the commit root of the extent tree for looking up back
references, however we track the reloc roots based on their current
bytenr.
This is wrong, if we commit the transaction between relocating tree
blocks we could end up in this code in build_backref_tree
if (key.objectid == key.offset) {
/*
* Only root blocks of reloc trees use backref
* pointing to itself.
*/
root = find_reloc_root(rc, cur->bytenr);
ASSERT(root);
cur->root = root;
break;
}
find_reloc_root() is looking based on the bytenr we had in the commit
root, but if we've COWed this reloc root we will not find that bytenr,
and we will trip over the ASSERT(root).
Fix this by using the commit_root->start bytenr for indexing the commit
root. Then we change the __update_reloc_root() caller to be used when
we switch the commit root for the reloc root during commit.
This fixes the panic I was seeing when we started throttling relocation
for delayed refs.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There are two bugs here, but fixing them independently would just result
in pain if you happened to bisect between the two patches.
First is how we handle the -EAGAIN from relocate_tree_block(). We don't
set error, unless we happen to be the first node, which makes no sense,
I have no idea what the code was trying to accomplish here.
We in fact _do_ want err set here so that we know we need to restart in
relocate_block_group(). Also we need finish_pending_nodes() to not
actually call link_to_upper(), because we didn't actually relocate the
block.
And then if we do get -EAGAIN we do not want to set our backref cache
last_trans to the one before ours. This would force us to update our
backref cache if we didn't cross transaction ids, which would mean we'd
have some nodes updated to their new_bytenr, but still able to find
their old bytenr because we're searching the same commit root as the
last time we went through relocate_tree_blocks.
Fixing these two things keeps us from panicing when we start breaking
out of relocate_tree_blocks() either for delayed ref flushing or enospc.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Since we're not only checking for metadata reservations but also if we
need to throttle our delayed ref generation, reorder
reserve_metadata_space() above the select_one_root() call in
relocate_tree_block().
The reason we want this is because select_reloc_root() will mess with
the backref cache, and if we're going to bail we want to be able to
cleanly remove this node from the backref cache and come back along to
regenerate it. Move it up so this is the first thing we do to make
restarting cleaner.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Here we are just searching down to the bytenr we're building the backref
tree for, and all of it's paths to the roots. These bytenrs are not
guaranteed to be anywhere near each other, so readahead just generates
extra latency.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Readahead will generate a lot of extra reads for adjacent nodes, but
when running delayed refs we have no idea if the next ref is going to be
adjacent or not, so this potentially just generates a lot of extra IO.
To make matters worse each ref is truly just looking for one item, it
doesn't generally search forward, so we simply don't need it here.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
With BTRFS_SUBVOL_CREATE_ASYNC support remove it's no longer required to
pass the async_transid parameter so remove it and any code using it.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
btrfs_ioctl_snap_create_transid no longer takes a transid argument, so
remove it and rename the function to __btrfs_ioctl_snap_create to
reflect it's an internal, worker function.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This functionality was deprecated in kernel 5.4. Since no one has
complained of the impending removal it's time we did so.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add comment ]
Signed-off-by: David Sterba <dsterba@suse.com>
Now that we have proper root ref counting everywhere we can kill the
subvol_srcu.
* removal of fs_info::subvol_srcu reduces size of fs_info by 1176 bytes
* the refcount_t used for the references checks for accidental 0->1
in cases where the root lifetime would not be properly protected
* there's a leak detector for roots to catch unfreed roots at umount
time
* SRCU served us well over the years but is was not a proper
synchronization mechanism for some cases
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
The radix root is primarily protected by the fs_roots_radix_lock, so use
that to lookup and get a ref on all of our fs roots in
btrfs_cleanup_fs_roots. The tree reference is taken in the protected
section as before.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Now that all the users of roots take references for them we can drop the
extra root ref we've been taking. Before we had roots at 2 refs for the
life of the file system, one for the radix tree, and one simply for
existing. Now that we have proper ref accounting in all places that use
roots we can drop this extra ref simply for existing as we no longer
need it.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
At the point we add a root to the dead roots list we have no open inodes
for that root, so we need to hold a ref on that root to keep it from
disappearing.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
If we make sure all the inodes have refs on their root we don't have to
worry about the root disappearing while we have open inodes.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There are a few different ways to free roots, either you allocated them
yourself and you just do
free_extent_buffer(root->node);
free_extent_buffer(root->commit_node);
btrfs_put_root(root);
Which is the pattern for log roots. Or for snapshots/subvolumes that
are being dropped you simply call btrfs_free_fs_root() which does all
the cleanup for you.
Unify this all into btrfs_put_root(), so that we don't free up things
associated with the root until the last reference is dropped. This
makes the root freeing code much more significant.
The only caveat is at close_ctree() time we have to free the extent
buffers for all of our main roots (extent_root, chunk_root, etc) because
we have to drop the btree_inode and we'll run into issues if we hold
onto those nodes until ->kill_sb() time. This will be addressed in the
future when we kill the btree_inode.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We are going to make root life be controlled soley by refcounting, and
inodes will be one of the things that hold a ref on the root. This
means we need to handle dropping the ino_cache_inode outside of the root
freeing logic, so move it into btrfs_drop_and_free_fs_root() so it is
cleaned up properly on unmount.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
I'm going to make the entire destruction of btrfs_root's controlled by
their refcount, so it will be helpful to notice if we're leaking their
eb's on umount.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This was pretty subtle, we default to reloc roots having 0 root refs, so
if we crash in the middle of the relocation they can just be deleted.
If we successfully complete the relocation operations we'll set our root
refs to 1 in prepare_to_merge() and then go on to merge_reloc_roots().
At prepare_to_merge() time if any of the reloc roots have a 0 reference
still, we will remove that reloc root from our reloc root rb tree, and
then clean it up later.
However this only happens if we successfully start a transaction. If
we've aborted previously we will skip this step completely, and only
have reloc roots with a reference count of 0, but were never properly
removed from the reloc control's rb tree.
This isn't a problem per-se, our references are held by the list the
reloc roots are on, and by the original root the reloc root belongs to.
If we end up in this situation all the reloc roots will be added to the
dirty_reloc_list, and then properly dropped at that point. The reloc
control will be free'd and the rb tree is no longer used.
There were two options when fixing this, one was to remove the BUG_ON(),
the other was to make prepare_to_merge() handle the case where we
couldn't start a trans handle.
IMO this is the cleaner solution. I started with handling the error in
prepare_to_merge(), but it turned out super ugly. And in the end this
BUG_ON() simply doesn't matter, the cleanup was happening properly, we
were just panicing because this BUG_ON() only matters in the success
case. So I've opted to just remove it and add a comment where it was.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We previously were relying on root->reloc_root to be cleaned up by the
drop snapshot, or the error handling. However if btrfs_drop_snapshot()
failed it wouldn't drop the ref for the root. Also we sort of depend on
the right thing to happen with moving reloc roots between lists and the
fs root they belong to, which makes it hard to figure out who owns the
reference.
Fix this by explicitly holding a reference on the reloc root for
roo->reloc_root. This means that we hold two references on reloc roots,
one for whichever reloc_roots list it's attached to, and the
root->reloc_root we're on.
This makes it easier to reason out who owns a reference on the root, and
when it needs to be dropped.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The DEAD_RELOC_TREE flag is in place in order to avoid a use after free
in init_reloc_root, tracking the presence of reloc_root. However adding
the explicit tree references in previous patches makes the use after
free impossible because at this point we no longer have a reloc_control
set on the fs_info and thus cannot enter the function.
So move this to be coupled with clearing the root->reloc_root so we're
consistent with all other operations of the reloc root.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
If we have an error while processing the reloc roots we could leak roots
that were added to rc->reloc_roots before we hit the error. We could
have also not removed the reloc tree mapping from our rb_tree, so clean
up any remaining nodes in the reloc root rb_tree.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ use rbtree_postorder_for_each_entry_safe ]
Signed-off-by: David Sterba <dsterba@suse.com>
We previously were checking if the root had a dead root before accessing
root->reloc_root in order to avoid a use-after-free type bug. However
this scenario happens after we've unset the reloc control, so we would
have been saved if we'd simply checked for fs_info->reloc_control. At
this point during relocation we no longer need to be creating new reloc
roots, so simply move this check above the reloc_root checks to avoid
any future races and confusion.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
If we do merge_reloc_roots() we could insert a few roots onto the dirty
subvol roots list, where we hold a ref on them. If we fail to start the
transaction we need to run clean_dirty_subvols() in order to cleanup the
refs.
CC: stable@vger.kernel.org # 5.4+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
If we fail to load an fs root, or fail to start a transaction we can
bail without unsetting the reloc control, which leads to problems later
when we free the reloc control but still have it attached to the file
system.
In the normal path we'll end up calling unset_reloc_control() twice, but
all it does is set fs_info->reloc_control = NULL, and we can only have
one balance at a time so it's not racey.
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
If we have an error while building the backref tree in relocation we'll
process all the pending edges and then free the node. However if we
integrated some edges into the cache we'll lose our link to those edges
by simply freeing this node, which means we'll leak memory and
references to any roots that we've found.
Instead we need to use remove_backref_node(), which walks through all of
the edges that are still linked to this node and free's them up and
drops any root references we may be holding.
CC: stable@vger.kernel.org # 4.9+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In relocation, we need to locate all parent tree leaves referring to one
data extent, thus we have a complex mechanism to iterate throught extent
tree and subvolume trees to locate the related leaves.
However this is already done in backref.c, we have
btrfs_find_all_leafs(), which can return a ulist containing all leaves
referring to that data extent.
Use btrfs_find_all_leafs() to replace find_data_references().
There is a special handling for v1 space cache data extents, where we
need to delete the v1 space cache data extents, to avoid those data
extents to hang the data relocation.
In this patch, the special handling is done by re-iterating the root
tree leaf. Although it's a little less efficient than the old handling,
considering we can reuse a lot of code, it should be acceptable.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
While debugging I noticed I wasn't getting ref verify errors before
everything blew up. Turns out it's because we don't warn when we try to
add a normal ref via btrfs_inc_ref() if the block entry exists but has 0
references. This is incorrect, we should never be doing anything other
than adding a new extent once a block entry drops to 0 references.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Commit 0c713cbab6 ("Btrfs: fix race between ranged fsync and writeback
of adjacent ranges") fixed a bug where we could end up with file extent
items in a log tree that represent file ranges that overlap due to a race
between the hole detection of a ranged full fsync and writeback for a
different file range.
The problem was solved by forcing any ranged full fsync to become a
non-ranged full fsync - setting the range start to 0 and the end offset to
LLONG_MAX. This was a simple solution because the code that detected and
marked holes was very complex, it used to be done at copy_items() and
implied several searches on the fs/subvolume tree. The drawback of that
solution was that we started to flush delalloc for the entire file and
wait for all the ordered extents to complete for ranged full fsyncs
(including ordered extents covering ranges completely outside the given
range). Fortunatelly ranged full fsyncs are not the most common case
(hopefully for most workloads).
However a later fix for detecting and marking holes was made by commit
0e56315ca1 ("Btrfs: fix missing hole after hole punching and fsync
when using NO_HOLES") and it simplified a lot the detection of holes,
and now copy_items() no longer does it and we do it in a much more simple
way at btrfs_log_holes().
This makes it now possible to simply make the code that detects holes to
operate only on the initial range and no longer need to operate on the
whole file, while also avoiding the need to flush delalloc for the entire
file and wait for ordered extents that cover ranges that don't overlap the
given range.
Another special care is that we must skip file extent items that fall
entirely outside the fsync range when copying inode items from the
fs/subvolume tree into the log tree - this is to avoid races with ordered
extent completion for extents falling outside the fsync range, which could
cause us to end up with file extent items in the log tree that have
overlapping ranges - for example if the fsync range is [1Mb, 2Mb], when
we copy inode items we could copy an extent item for the range [0, 512K],
then release the search path and before moving to the next leaf, an
ordered extent for a range of [256Kb, 512Kb] completes - this would
cause us to copy the new extent item for range [256Kb, 512Kb] into the
log tree after we have copied one for the range [0, 512Kb] - the extents
overlap, resulting in a corruption.
So this change just does these steps:
1) When the NO_HOLES feature is enabled it leaves the initial range
intact - no longer sets it to [0, LLONG_MAX] when the full sync bit
is set in the inode. If NO_HOLES is not enabled, always set the range
to a full, just like before this change, to avoid missing file extent
items representing holes after replaying the log (for both full and
fast fsyncs);
2) Make the hole detection code to operate only on the fsync range;
3) Make the code that copies items from the fs/subvolume tree to skip
copying file extent items that cover a range completely outside the
range of the fsync.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The function btrfs_log_inode() is quite large and so is its loop which
iterates the inode items from the fs/subvolume tree and copies them into
a log tree. Because this is a large loop inside a very large function
and because an upcoming patch in this series needs to add some more logic
inside that loop, move the loop into a helper function to make it a bit
more manageable.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Getting the end offset for a file extent item requires a bit of code since
the extent can be either inline or regular/prealloc. There are some places
all over the code base that open code this logic and in another patch
later in this series it will be needed again. Therefore encapsulate this
logic in a helper function and use it.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When doing a fast fsync for a range that starts at an offset greater than
zero, we can end up with a log that when replayed causes the respective
inode miss a file extent item representing a hole if we are not using the
NO_HOLES feature. This is because for fast fsyncs we don't log any extents
that cover a range different from the one requested in the fsync.
Example scenario to trigger it:
$ mkfs.btrfs -O ^no-holes -f /dev/sdd
$ mount /dev/sdd /mnt
# Create a file with a single 256K and fsync it to clear to full sync
# bit in the inode - we want the msync below to trigger a fast fsync.
$ xfs_io -f -c "pwrite -S 0xab 0 256K" -c "fsync" /mnt/foo
# Force a transaction commit and wipe out the log tree.
$ sync
# Dirty 768K of data, increasing the file size to 1Mb, and flush only
# the range from 256K to 512K without updating the log tree
# (sync_file_range() does not trigger fsync, it only starts writeback
# and waits for it to finish).
$ xfs_io -c "pwrite -S 0xcd 256K 768K" /mnt/foo
$ xfs_io -c "sync_range -abw 256K 256K" /mnt/foo
# Now dirty the range from 768K to 1M again and sync that range.
$ xfs_io -c "mmap -w 768K 256K" \
-c "mwrite -S 0xef 768K 256K" \
-c "msync -s 768K 256K" \
-c "munmap" \
/mnt/foo
<power fail>
# Mount to replay the log.
$ mount /dev/sdd /mnt
$ umount /mnt
$ btrfs check /dev/sdd
Opening filesystem to check...
Checking filesystem on /dev/sdd
UUID: 482fb574-b288-478e-a190-a9c44a78fca6
[1/7] checking root items
[2/7] checking extents
[3/7] checking free space cache
[4/7] checking fs roots
root 5 inode 257 errors 100, file extent discount
Found file extent holes:
start: 262144, len: 524288
ERROR: errors found in fs roots
found 720896 bytes used, error(s) found
total csum bytes: 512
total tree bytes: 131072
total fs tree bytes: 32768
total extent tree bytes: 16384
btree space waste bytes: 123514
file data blocks allocated: 589824
referenced 589824
Fix this issue by setting the range to full (0 to LLONG_MAX) when the
NO_HOLES feature is not enabled. This results in extra work being done
but it gives the guarantee we don't end up with missing holes after
replaying the log.
CC: stable@vger.kernel.org # 4.19+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Instead of iterating all pending tickets on the normal/priority list to
sum their total size the cost can be amortized across ticket addition/
removal. This turns O(n) + O(m) (where n is the size of the normal list
and m of the priority list) into O(1). This will mostly have effect in
workloads that experience heavy flushing.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently btrfs doesn't provide a migratepage callback for data pages.
It means that fallback_migrate_page() is used to migrate btrfs pages.
fallback_migrate_page() cannot move dirty pages, instead it tries to
flush them (in sync mode) or just fails (in async mode).
In the sync mode pages which are scheduled to be processed by
btrfs_writepage_fixup_worker() can't be effectively flushed by the
migration code, because there is no established way to wait for the
completion of the delayed work.
It all leads to page migration failures.
To fix it the patch implements a btrs-specific migratepage callback,
which is similar to iomap_migrate_page() used by some other fs, except
it does take care of the PagePrivate2 flag which is used for data
ordering purposes.
Reviewed-by: Chris Mason <clm@fb.com>
Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
It's no longer used following 30d40577e3 ("btrfs: reloc: Also queue
orphan reloc tree for cleanup to avoid BUG_ON()"), so just remove it.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently the non-prefixed version is a simple wrapper used to hide
the 4th argument of the prefixed version. This doesn't bring much value
in practice and only makes the code harder to follow by adding another
level of indirection. Rectify this by removing the __ prefix and
have only one public function to release bytes from a block reservation.
No semantic changes.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When relocating data block groups with tons of small extents, or large
metadata block groups, there can be over 200,000 extents.
We will iterate all extents of such block group in relocate_block_group(),
where iteration itself can be kinda time-consuming.
So when user want to cancel the balance, the extent iteration loop can
be another target.
This patch will add the cancelling check in the extent iteration loop of
relocate_block_group() to make balance cancelling faster.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When relocating a data extents with large large data extents, we spend
most of our time in relocate_file_extent_cluster() at stage "moving data
extents":
1) | btrfs_relocate_block_group [btrfs]() {
1) | relocate_file_extent_cluster [btrfs]() {
1) $ 6586769 us | }
1) + 18.260 us | relocate_file_extent_cluster [btrfs]();
1) + 15.770 us | relocate_file_extent_cluster [btrfs]();
1) $ 8916340 us | }
1) | btrfs_relocate_block_group [btrfs]() {
1) | relocate_file_extent_cluster [btrfs]() {
1) $ 11611586 us | }
1) + 16.930 us | relocate_file_extent_cluster [btrfs]();
1) + 15.870 us | relocate_file_extent_cluster [btrfs]();
1) $ 14986130 us | }
To make data relocation cancelling quicker, add extra balance cancelling
check after each page read in relocate_file_extent_cluster().
Cleanup and error handling uses the same mechanism as if the whole
process finished
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Introduce a new error injection point, should_cancel_balance().
It's just a wrapper of atomic_read(&fs_info->balance_cancel_req), but
allows us to override the return value.
Currently there are only one locations using this function:
- btrfs_balance()
It checks cancel before each block group.
There are other locations checking fs_info->balance_cancel_req, but they
are not used as an indicator to exit, so there is no need to use the
wrapper.
But there will be more locations coming, and some locations can cause
kernel panic if not handled properly. So introduce this error injection
to provide better test interface.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There are a few cases where we don't allow cloning an inline extent into
the destination inode, returning -EOPNOTSUPP to user space. This was done
to prevent several types of file corruption and because it's not very
straightforward to deal with these cases, as they can't rely on simply
copying the inline extent between leaves. Such cases require copying the
inline extent's data into the respective page of the destination inode.
Not supporting these cases makes it harder and more cumbersome to write
applications/libraries that work on any filesystem with reflink support,
since all these cases for which btrfs fails with -EOPNOTSUPP work just
fine on xfs for example. These unsupported cases are also not documented
anywhere and explaining which exact cases fail require a bit of too
technical understanding of btrfs's internal (inline extents and when and
where can they exist in a file), so it's not really user friendly.
Also some test cases from fstests that use fsx, such as generic/522 for
example, can sporadically fail because they trigger one of these cases,
and fsx expects all operations to succeed.
This change adds supports for cloning all these cases by copying the
inline extent's data into the respective page of the destination inode.
With this change test case btrfs/112 from fstests fails because it
expects some clone operations to fail, so it will be updated. Also a
new test case that exercises all these previously unsupported cases
will be added to fstests.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We can not reflink parts of an inline extent, we must always reflink the
whole inline extent. We know that inline extents always start at file
offset 0 and that can never represent an amount of data larger then the
filesystem's sector size (both compressed and uncompressed). We also have
had the constraints that reflink operations must have a start offset that
is aligned to the sector size and an end offset that is also aligned or
it ends the inode's i_size, so there's no way for user space to be able
to do a reflink operation that will refer to only a part of an inline
extent.
Initially there was a bug in the inlining code that could allow compressed
inline extents that encoded more than 1 page, but that was fixed in 2008
by commit 70b99e6959 ("Btrfs: Compression corner fixes") since that
was problematic.
So remove all the extent cloning code that deals with the possibility
of cloning only partial inline extents.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The reflink code is quite large and has been living in ioctl.c since ever.
It has grown over the years after many bug fixes and improvements, and
since I'm planning on making some further improvements on it, it's time
to get it better organized by moving into its own file, reflink.c
(similar to what xfs does for example).
This change only moves the code out of ioctl.c into the new file, it
doesn't do any other change.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array
member[1][2], introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning in
case the flexible array does not occur last in the structure, which will
help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by this
change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero." [1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array
member[1][2], introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning in
case the flexible array does not occur last in the structure, which will
help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by this
change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero." [1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array
member[1][2], introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning in
case the flexible array does not occur last in the structure, which will
help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by this
change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero." [1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The space_info list is normally RCU protected and should be traversed
with rcu_read_lock held. There's a warning
[29.104756] WARNING: suspicious RCU usage
[29.105046] 5.6.0-rc4-next-20200305 #1 Not tainted
[29.105231] -----------------------------
[29.105401] fs/btrfs/block-group.c:2011 RCU-list traversed in non-reader section!!
pointing out that the locking is missing in btrfs_read_block_groups.
However this is not necessary as the list traversal happens at mount
time when there's no other thread potentially accessing the list.
To fix the warning and for consistency let's add the RCU lock/unlock,
the code won't be affected much as it's doing some lightweight
operations.
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
No need to add a level of indirection for hiding a simple 'if'. Open
code insert_extent_backref in its sole caller. No functional changes.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
relocate_tree_blocks calls get_tree_block_key for a block iff that block
has its ->key_ready equal false. Thus the BUG_ON in the latter function
cannot ever be triggered so remove it.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The validation follows the same steps for all three block group types,
the existing helper validate_convert_profile can be enhanced and do more
of the common things.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Now that csum_tree_block is not returning any errors, we can make
csum_tree_block return void and simplify callers.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Thw whole point of csum_tree_block is to iterate over all extent buffer
pages and pass it to checksumming functions. The bytes where checksum is
stored must be skipped, thus map_private_extent_buffer. This complicates
further offset calculations.
As the first page will be always present, checksum the relevant bytes
unconditionally and then do a simple iteration over the remaining pages.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There's an unnecessary indirection in the checksum definition table,
pointer and the string itself. The strings are short and the overall
size of one entry is now 24 bytes.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Having btrfs_alloc_chunk doesn't bring any value since it
encapsulates a lockdep assert and a call to find_next_chunk. Simply
rename the internal __btrfs_alloc_chunk function to the public one
and remove it's 2nd parameter as all callers always pass the return
value of find_next_chunk. Finally, migrate the call to
lockdep_assert_held so as to not lose the check.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
I noticed while running my snapshot torture test that we were getting a
lot of metadata chunks allocated with very little actually used.
Digging into this we would commit the transaction, still not have enough
space, and then force a chunk allocation.
I noticed that we were barely flushing any delalloc at all, despite the
fact that we had around 13gib of outstanding delalloc reservations. It
turns out this is because of our btrfs_calc_reclaim_metadata_size()
calculation. It _only_ takes into account the outstanding ticket sizes,
which isn't the whole story. In this particular workload we're slowly
filling up the disk, which means our overcommit space will suddenly
become a lot less, and our outstanding reservations will be well more
than what we can handle. However we are only flushing based on our
ticket size, which is much less than we need to actually reclaim.
So fix btrfs_calc_reclaim_metadata_size() to take into account the
overage in the case that we've gotten less available space suddenly.
This makes it so we attempt to reclaim a lot more delalloc space, which
allows us to make our reservations and we no longer are allocating a
bunch of needless metadata chunks.
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
During unmount we can have a job from the delayed inode items work queue
still running, that can lead to at least two bad things:
1) A crash, because the worker can try to create a transaction just
after the fs roots were freed;
2) A transaction leak, because the worker can create a transaction
before the fs roots are freed and just after we committed the last
transaction and after we stopped the transaction kthread.
A stack trace example of the crash:
[79011.691214] kernel BUG at lib/radix-tree.c:982!
[79011.692056] invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI
[79011.693180] CPU: 3 PID: 1394 Comm: kworker/u8:2 Tainted: G W 5.6.0-rc2-btrfs-next-54 #2
(...)
[79011.696789] Workqueue: btrfs-delayed-meta btrfs_work_helper [btrfs]
[79011.697904] RIP: 0010:radix_tree_tag_set+0xe7/0x170
(...)
[79011.702014] RSP: 0018:ffffb3c84a317ca0 EFLAGS: 00010293
[79011.702949] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
[79011.704202] RDX: ffffb3c84a317cb0 RSI: ffffb3c84a317ca8 RDI: ffff8db3931340a0
[79011.705463] RBP: 0000000000000005 R08: 0000000000000005 R09: ffffffff974629d0
[79011.706756] R10: ffffb3c84a317bc0 R11: 0000000000000001 R12: ffff8db393134000
[79011.708010] R13: ffff8db3931340a0 R14: ffff8db393134068 R15: 0000000000000001
[79011.709270] FS: 0000000000000000(0000) GS:ffff8db3b6a00000(0000) knlGS:0000000000000000
[79011.710699] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[79011.711710] CR2: 00007f22c2a0a000 CR3: 0000000232ad4005 CR4: 00000000003606e0
[79011.712958] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[79011.714205] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[79011.715448] Call Trace:
[79011.715925] record_root_in_trans+0x72/0xf0 [btrfs]
[79011.716819] btrfs_record_root_in_trans+0x4b/0x70 [btrfs]
[79011.717925] start_transaction+0xdd/0x5c0 [btrfs]
[79011.718829] btrfs_async_run_delayed_root+0x17e/0x2b0 [btrfs]
[79011.719915] btrfs_work_helper+0xaa/0x720 [btrfs]
[79011.720773] process_one_work+0x26d/0x6a0
[79011.721497] worker_thread+0x4f/0x3e0
[79011.722153] ? process_one_work+0x6a0/0x6a0
[79011.722901] kthread+0x103/0x140
[79011.723481] ? kthread_create_worker_on_cpu+0x70/0x70
[79011.724379] ret_from_fork+0x3a/0x50
(...)
The following diagram shows a sequence of steps that lead to the crash
during ummount of the filesystem:
CPU 1 CPU 2 CPU 3
btrfs_punch_hole()
btrfs_btree_balance_dirty()
btrfs_balance_delayed_items()
--> sees
fs_info->delayed_root->items
with value 200, which is greater
than
BTRFS_DELAYED_BACKGROUND (128)
and smaller than
BTRFS_DELAYED_WRITEBACK (512)
btrfs_wq_run_delayed_node()
--> queues a job for
fs_info->delayed_workers to run
btrfs_async_run_delayed_root()
btrfs_async_run_delayed_root()
--> job queued by CPU 1
--> starts picking and running
delayed nodes from the
prepare_list list
close_ctree()
btrfs_delete_unused_bgs()
btrfs_commit_super()
btrfs_join_transaction()
--> gets transaction N
btrfs_commit_transaction(N)
--> set transaction state
to TRANTS_STATE_COMMIT_START
btrfs_first_prepared_delayed_node()
--> picks delayed node X through
the prepared_list list
btrfs_run_delayed_items()
btrfs_first_delayed_node()
--> also picks delayed node X
but through the node_list
list
__btrfs_commit_inode_delayed_items()
--> runs all delayed items from
this node and drops the
node's item count to 0
through call to
btrfs_release_delayed_inode()
--> finishes running any remaining
delayed nodes
--> finishes transaction commit
--> stops cleaner and transaction threads
btrfs_free_fs_roots()
--> frees all roots and removes them
from the radix tree
fs_info->fs_roots_radix
btrfs_join_transaction()
start_transaction()
btrfs_record_root_in_trans()
record_root_in_trans()
radix_tree_tag_set()
--> crashes because
the root is not in
the radix tree
anymore
If the worker is able to call btrfs_join_transaction() before the unmount
task frees the fs roots, we end up leaking a transaction and all its
resources, since after the call to btrfs_commit_super() and stopping the
transaction kthread, we don't expect to have any transaction open anymore.
When this situation happens the worker has a delayed node that has no
more items to run, since the task calling btrfs_run_delayed_items(),
which is doing a transaction commit, picks the same node and runs all
its items first.
We can not wait for the worker to complete when running delayed items
through btrfs_run_delayed_items(), because we call that function in
several phases of a transaction commit, and that could cause a deadlock
because the worker calls btrfs_join_transaction() and the task doing the
transaction commit may have already set the transaction state to
TRANS_STATE_COMMIT_DOING.
Also it's not possible to get into a situation where only some of the
items of a delayed node are added to the fs/subvolume tree in the current
transaction and the remaining ones in the next transaction, because when
running the items of a delayed inode we lock its mutex, effectively
waiting for the worker if the worker is running the items of the delayed
node already.
Since this can only cause issues when unmounting a filesystem, fix it in
a simple way by waiting for any jobs on the delayed workers queue before
calling btrfs_commit_supper() at close_ctree(). This works because at this
point no one can call btrfs_btree_balance_dirty() or
btrfs_balance_delayed_items(), and if we end up waiting for any worker to
complete, btrfs_commit_super() will commit the transaction created by the
worker.
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This function finally factor out prepare_allocation() form
find_free_extent(). This function is called before the allocation loop
and a specific allocator function like prepare_allocation_clustered()
should initialize their private information and can set proper hint_byte
to indicate where to start the allocation with.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
LOOP_NO_EMPTY_SIZE is solely dedicated for clustered allocation. So, we
can skip this stage and give up the allocation.
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Factor out chunk_allocation_failed() from
find_free_extent_update_loop(). This function is called when it failed
to allocate a chunk. The function can modify "ffe_ctl->loop" and return
0 to continue with the next stage. Or, it can return -ENOSPC to give up
here.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Now that, we don't use last_ptr and use_cluster in the function. Drop
these arguments from it.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Factor out found_extent() from find_free_extent_update_loop(). This
function is called when a proper extent is found and before returning
from find_free_extent(). Hook functions like found_extent_clustered()
should save information for a next allocation.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Factor out release_block_group() from find_free_extent(). This function
is called when it gives up an allocation from a block group. Each
allocation policy should reset its information for an allocation in
the next block group.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Now that, find_free_extent_clustered() and find_free_extent_unclustered()
can access "last_ptr" from the "clustered" variable, we can drop it from
the arguments.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Factor out do_allocation() from find_free_extent(). This function do an
actual extent allocation in a given block group. The ffe_ctl->policy is
used to determine the actual allocator function to use.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Move "last_ptr" and "use_cluster" into struct find_free_extent_ctl, so
that hook functions for clustered allocator can use these variables.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit moves hint_byte into find_free_extent_ctl, so that we can
modify the hint_byte in the other functions. This will help us split
find_free_extent further. This commit also renames the function argument
"hint_byte" to "hint_byte_orig" to avoid misuse.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit introduces extent allocation policy for btrfs. This policy
controls how btrfs allocate an extents from block groups. There is no
functional change introduced with this commit.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently, we ignore a device whose available space is less than
"BTRFS_STRIPE_LEN * dev_stripes". This is a lower limit for current
allocation policy (to maximize the number of stripes). This commit
parameterizes dev_extent_min, so that other policies can set their own
lower limitat to ignore a device with insufficient space.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Factor out create_chunk() from __btrfs_alloc_chunk(). This function
finally creates a chunk. There is no functional changes.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Factor out decide_stripe_size() from __btrfs_alloc_chunk(). This
function calculates the actual stripe size to allocate.
decide_stripe_size() handles the common case to round down the 'ndevs'
to 'devs_increment' and check the upper and lower limitation of 'ndevs'.
decide_stripe_size_regular() decides the size of a stripe and the size
of a chunk. The policy is to maximize the number of stripes.
This commit has no functional changes.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Factor out gather_device_info() from __btrfs_alloc_chunk(). This
function iterates over devices list and gather information about
devices. This commit also introduces "max_avail" and
"dev_extent_min" to fold the same calculation to one variable.
This commit has no functional changes.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Factor out init_alloc_chunk_ctl() from __btrfs_alloc_chunk(). This
function initialises parameters of "struct alloc_chunk_ctl" for
allocation. init_alloc_chunk_ctl() handles a common part of the
initialisation to load the RAID parameters from btrfs_raid_array.
init_alloc_chunk_ctl_policy_regular() decides some parameters for its
allocation.
The last "else" case in the original code is moved to
__btrfs_alloc_chunk() to handle the error case in the common code.
Replace the BUG_ON with ASSERT() and error return at the same time.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Introduce "struct alloc_chunk_ctl" to wrap needed parameters for the
chunk allocation. This will be used to split __btrfs_alloc_chunk() into
smaller functions.
This commit folds a number of local variables in __btrfs_alloc_chunk()
into one "struct alloc_chunk_ctl ctl". There is no functional change.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
