Change writeback path to create just one io_end structure for the
extent to which we submit IO and share it among bios writing that
extent. This prevents needless splitting and joining of unwritten
extents when they cannot be submitted as a single bio.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Dmitry Monakhov <dmonakhov@openvz.org>
Reviewed-by: Zheng Liu <wenqing.lz@taobao.com>
Currently in ENOSPC condition when writing into unwritten space, or
punching a hole, we might need to split the extent and grow extent tree.
However since we can not allocate any new metadata blocks we'll have to
zero out unwritten part of extent or punched out part of extent, or in
the worst case return ENOSPC even though use actually does not allocate
any space.
Also in delalloc path we do reserve metadata and data blocks for the
time we're going to write out, however metadata block reservation is
very tricky especially since we expect that logical connectivity implies
physical connectivity, however that might not be the case and hence we
might end up allocating more metadata blocks than previously reserved.
So in future, metadata reservation checks should be removed since we can
not assure that we do not under reserve.
And this is where reserved space comes into the picture. When mounting
the file system we slice off a little bit of the file system space (2%
or 4096 clusters, whichever is smaller) which can be then used for the
cases mentioned above to prevent costly zeroout, or unexpected ENOSPC.
The number of reserved clusters can be set via sysfs, however it can
never be bigger than number of free clusters in the file system.
Note that this patch fixes the failure of xfstest 274 as expected.
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Values stored in s_freeclusters_counter and s_dirtyclusters_counter
are both in cluster units. Remove the cluster to block conversion
applied to s_freeclusters_counter causing an inflated estimate of
free space because s_dirtyclusters_counter is not similarly
converted. Rename free_blocks and dirty_blocks to better reflect
the units these variables contain to avoid future confusion. This
fix corrects ENOSPC failures for xfstests 127 and 231 on bigalloc
file systems.
Signed-off-by: Eric Whitney <enwlinux@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Add a new ioctl, EXT4_IOC_SWAP_BOOT which swaps i_blocks and
associated attributes (like i_blocks, i_size, i_flags, ...) from the
specified inode with inode EXT4_BOOT_LOADER_INO (#5). This is
typically used to store a boot loader in a secure part of the
filesystem, where it can't be changed by a normal user by accident.
The data blocks of the previous boot loader will be associated with
the given inode.
This usercode program is a simple example of the usage:
int main(int argc, char *argv[])
{
int fd;
int err;
if ( argc != 2 ) {
printf("usage: ext4-swap-boot-inode FILE-TO-SWAP\n");
exit(1);
}
fd = open(argv[1], O_WRONLY);
if ( fd < 0 ) {
perror("open");
exit(1);
}
err = ioctl(fd, EXT4_IOC_SWAP_BOOT);
if ( err < 0 ) {
perror("ioctl");
exit(1);
}
close(fd);
exit(0);
}
[ Modified by Theodore Ts'o to fix a number of bugs in the original code.]
Signed-off-by: Dr. Tilmann Bubeck <t.bubeck@reinform.de>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
In the case where an inode has a very stale transaction id (tid) in
i_datasync_tid or i_sync_tid, it's possible that after a very large
(2**31) number of transactions, that the tid number space might wrap,
causing tid_geq()'s calculations to fail.
Commit deeeaf13 "jbd2: fix fsync() tid wraparound bug", later modified
by commit e7b04ac0 "jbd2: don't wake kjournald unnecessarily",
attempted to fix this problem, but it only avoided kjournald spinning
forever by fixing the logic in jbd2_log_start_commit().
Unfortunately, in the codepaths in fs/ext4/fsync.c and fs/ext4/inode.c
that might call jbd2_log_start_commit() with a stale tid, those
functions will subsequently call jbd2_log_wait_commit() with the same
stale tid, and then wait for a very long time. To fix this, we
replace the calls to jbd2_log_start_commit() and
jbd2_log_wait_commit() with a call to a new function,
jbd2_complete_transaction(), which will correctly handle stale tid's.
As a bonus, jbd2_complete_transaction() will avoid locking
j_state_lock for writing unless a commit needs to be started. This
should have a small (but probably not measurable) improvement for
ext4's scalability.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reported-by: Ben Hutchings <ben@decadent.org.uk>
Reported-by: George Barnett <gbarnett@atlassian.com>
Cc: stable@vger.kernel.org
[ Added fixup from Lukáš Czerner which only checks the assertion when
the inode is not new and is not being freed. ]
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Move common code in ext4_ind_truncate() and ext4_ext_truncate() into
ext4_truncate(). This saves over 60 lines of code.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Move common code in ext4_ind_punch_hole() and ext4_ext_punch_hole()
into ext4_punch_hole(). This saves over 150 lines of code.
This also fixes a potential bug when the punch_hole() code is racing
against indirect-to-extents or extents-to-indirect migation. We are
currently using i_mutex to protect against changes to the inode flag;
specifically, the append-only, immutable, and extents inode flags. So
we need to take i_mutex before deciding whether to use the
extents-specific or indirect-specific punch_hole code.
Also, there was a missing call to ext4_inode_block_unlocked_dio() in
the indirect punch codepath. This was added in commit 02d262dffc
to block DIO readers racing against the punch operation in the
codepath for extent-mapped inodes, but it was missing for
indirect-block mapped inodes. One of the advantages of refactoring
the code is that it makes such oversights much less likely.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
After collapsing the handling of data ordered and data writeback
codepath, ext4_generic_write_end() has only one caller,
ext4_write_end(). So we fold it into ext4_write_end().
Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Lukas Czerner <lczerner@redhat.com>
The only difference between how we handle data=ordered and
data=writeback is a single call to ext4_jbd2_file_inode(). Eliminate
code duplication by factoring out redundant the code paths.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Lukas Czerner <lczerner@redhat.com>
relatively obscure cornercases or races that were found using
regression tests.
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Merge tag 'ext4_for_linue' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Pull ext4 fixes from Ted Ts'o:
"Fix a number of regression and other bugs in ext4, most of which were
relatively obscure cornercases or races that were found using
regression tests."
* tag 'ext4_for_linue' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (21 commits)
ext4: fix data=journal fast mount/umount hang
ext4: fix ext4_evict_inode() racing against workqueue processing code
ext4: fix memory leakage in mext_check_coverage
ext4: use s_extent_max_zeroout_kb value as number of kb
ext4: use atomic64_t for the per-flexbg free_clusters count
jbd2: fix use after free in jbd2_journal_dirty_metadata()
ext4: reserve metadata block for every delayed write
ext4: update reserved space after the 'correction'
ext4: do not use yield()
ext4: remove unused variable in ext4_free_blocks()
ext4: fix WARN_ON from ext4_releasepage()
ext4: fix the wrong number of the allocated blocks in ext4_split_extent()
ext4: update extent status tree after an extent is zeroed out
ext4: fix wrong m_len value after unwritten extent conversion
ext4: add self-testing infrastructure to do a sanity check
ext4: avoid a potential overflow in ext4_es_can_be_merged()
ext4: invalidate extent status tree during extent migration
ext4: remove unnecessary wait for extent conversion in ext4_fallocate()
ext4: add warning to ext4_convert_unwritten_extents_endio
ext4: disable merging of uninitialized extents
...
In data=journal mode, if we unmount the file system before a
transaction has a chance to complete, when the journal inode is being
evicted, we can end up calling into jbd2_log_wait_commit() for the
last transaction, after the journalling machinery has been shut down.
Arguably we should adjust ext4_should_journal_data() to return FALSE
for the journal inode, but the only place it matters is
ext4_evict_inode(), and so to save a bit of CPU time, and to make the
patch much more obviously correct by inspection(tm), we'll fix it by
explicitly not trying to waiting for a journal commit when we are
evicting the journal inode, since it's guaranteed to never succeed in
this case.
This can be easily replicated via:
mount -t ext4 -o data=journal /dev/vdb /vdb ; umount /vdb
------------[ cut here ]------------
WARNING: at /usr/projects/linux/ext4/fs/jbd2/journal.c:542 __jbd2_log_start_commit+0xba/0xcd()
Hardware name: Bochs
JBD2: bad log_start_commit: 3005630206 3005630206 0 0
Modules linked in:
Pid: 2909, comm: umount Not tainted 3.8.0-rc3 #1020
Call Trace:
[<c015c0ef>] warn_slowpath_common+0x68/0x7d
[<c02b7e7d>] ? __jbd2_log_start_commit+0xba/0xcd
[<c015c177>] warn_slowpath_fmt+0x2b/0x2f
[<c02b7e7d>] __jbd2_log_start_commit+0xba/0xcd
[<c02b8075>] jbd2_log_start_commit+0x24/0x34
[<c0279ed5>] ext4_evict_inode+0x71/0x2e3
[<c021f0ec>] evict+0x94/0x135
[<c021f9aa>] iput+0x10a/0x110
[<c02b7836>] jbd2_journal_destroy+0x190/0x1ce
[<c0175284>] ? bit_waitqueue+0x50/0x50
[<c028d23f>] ext4_put_super+0x52/0x294
[<c020efe3>] generic_shutdown_super+0x48/0xb4
[<c020f071>] kill_block_super+0x22/0x60
[<c020f3e0>] deactivate_locked_super+0x22/0x49
[<c020f5d6>] deactivate_super+0x30/0x33
[<c0222795>] mntput_no_expire+0x107/0x10c
[<c02233a7>] sys_umount+0x2cf/0x2e0
[<c02233ca>] sys_oldumount+0x12/0x14
[<c08096b8>] syscall_call+0x7/0xb
---[ end trace 6a954cc790501c1f ]---
jbd2_log_wait_commit: error: j_commit_request=-1289337090, tid=0
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: stable@vger.kernel.org
Commit 84c17543ab (ext4: move work from io_end to inode) triggered a
regression when running xfstest #270 when the file system is mounted
with dioread_nolock.
The problem is that after ext4_evict_inode() calls ext4_ioend_wait(),
this guarantees that last io_end structure has been freed, but it does
not guarantee that the workqueue structure, which was moved into the
inode by commit 84c17543ab, is actually finished. Once
ext4_flush_completed_IO() calls ext4_free_io_end() on CPU #1, this
will allow ext4_ioend_wait() to return on CPU #2, at which point the
evict_inode() codepath can race against the workqueue code on CPU #1
accessing EXT4_I(inode)->i_unwritten_work to find the next item of
work to do.
Fix this by calling cancel_work_sync() in ext4_ioend_wait(), which
will be renamed ext4_ioend_shutdown(), since it is only used by
ext4_evict_inode(). Also, move the call to ext4_ioend_shutdown()
until after truncate_inode_pages() and filemap_write_and_wait() are
called, to make sure all dirty pages have been written back and
flushed from the page cache first.
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<c01dda6a>] cwq_activate_delayed_work+0x3b/0x7e
*pdpt = 0000000030bc3001 *pde = 0000000000000000
Oops: 0000 [#1] SMP DEBUG_PAGEALLOC
Modules linked in:
Pid: 6, comm: kworker/u:0 Not tainted 3.8.0-rc3-00013-g84c1754-dirty #91 Bochs Bochs
EIP: 0060:[<c01dda6a>] EFLAGS: 00010046 CPU: 0
EIP is at cwq_activate_delayed_work+0x3b/0x7e
EAX: 00000000 EBX: 00000000 ECX: f505fe54 EDX: 00000000
ESI: ed5b697c EDI: 00000006 EBP: f64b7e8c ESP: f64b7e84
DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068
CR0: 8005003b CR2: 00000000 CR3: 30bc2000 CR4: 000006f0
DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
DR6: ffff0ff0 DR7: 00000400
Process kworker/u:0 (pid: 6, ti=f64b6000 task=f64b4160 task.ti=f64b6000)
Stack:
f505fe00 00000006 f64b7e9c c01de3d7 f6435540 00000003 f64b7efc c01def1d
f6435540 00000002 00000000 0000008a c16d0808 c040a10b c16d07d8 c16d08b0
f505fe00 c16d0780 00000000 00000000 ee153df4 c1ce4a30 c17d0e30 00000000
Call Trace:
[<c01de3d7>] cwq_dec_nr_in_flight+0x71/0xfb
[<c01def1d>] process_one_work+0x5d8/0x637
[<c040a10b>] ? ext4_end_bio+0x300/0x300
[<c01e3105>] worker_thread+0x249/0x3ef
[<c01ea317>] kthread+0xd8/0xeb
[<c01e2ebc>] ? manage_workers+0x4bb/0x4bb
[<c023a370>] ? trace_hardirqs_on+0x27/0x37
[<c0f1b4b7>] ret_from_kernel_thread+0x1b/0x28
[<c01ea23f>] ? __init_kthread_worker+0x71/0x71
Code: 01 83 15 ac ff 6c c1 00 31 db 89 c6 8b 00 a8 04 74 12 89 c3 30 db 83 05 b0 ff 6c c1 01 83 15 b4 ff 6c c1 00 89 f0 e8 42 ff ff ff <8b> 13 89 f0 83 05 b8 ff 6c c1
6c c1 00 31 c9 83
EIP: [<c01dda6a>] cwq_activate_delayed_work+0x3b/0x7e SS:ESP 0068:f64b7e84
CR2: 0000000000000000
---[ end trace a1923229da53d8a4 ]---
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Jan Kara <jack@suse.cz>
Currently we only reserve space (data+metadata) in delayed allocation if
we're allocating from new cluster (which is always in non-bigalloc file
system) which is ok for data blocks, because we reserve the whole cluster.
However we have to reserve metadata for every delayed block we're going
to write because every block could potentially require metedata block
when we need to grow the extent tree.
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Using yield() is strongly discouraged (see sched/core.c) especially
since we can just use cond_resched().
Replace all use of yield() with cond_resched().
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
ext4_releasepage() warns when it is passed a page with PageChecked set.
However this can correctly happen when invalidate_inode_pages2_range()
invalidates pages - and we should fail the release in that case. Since
the page was dirty anyway, it won't be discarded and no harm has
happened but it's good to be safe. Also remove bogus page_has_buffers()
check - we are guaranteed page has buffers in this function.
Reported-by: Zheng Liu <gnehzuil.liu@gmail.com>
Tested-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Jan Kara <jack@suse.cz>
When we try to split an extent, this extent could be zeroed out and mark
as initialized. But we don't know this in ext4_map_blocks because it
only returns a length of allocated extent. Meanwhile we will mark this
extent as uninitialized because we only check m_flags.
This commit update extent status tree when we try to split an unwritten
extent. We don't need to worry about the status of this extent because
we always mark it as initialized.
Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Dmitry Monakhov <dmonakhov@openvz.org>
This commit adds a self-testing infrastructure like extent tree does to
do a sanity check for extent status tree. After status tree is as a
extent cache, we'd better to make sure that it caches right result.
After applied this commit, we will get a lot of messages when we run
xfstests as below.
...
kernel: ES len assertation failed for inode: 230 retval 1 != map->m_len
3 in ext4_map_blocks (allocation)
...
kernel: ES cache assertation failed for inode: 230 es_cached ex
[974/2/4781/20] != found ex [974/1/4781/1000]
...
kernel: ES insert assertation failed for inode: 635 ex_status
[0/45/21388/w] != es_status [44/1/21432/u]
...
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Pull vfs pile (part one) from Al Viro:
"Assorted stuff - cleaning namei.c up a bit, fixing ->d_name/->d_parent
locking violations, etc.
The most visible changes here are death of FS_REVAL_DOT (replaced with
"has ->d_weak_revalidate()") and a new helper getting from struct file
to inode. Some bits of preparation to xattr method interface changes.
Misc patches by various people sent this cycle *and* ocfs2 fixes from
several cycles ago that should've been upstream right then.
PS: the next vfs pile will be xattr stuff."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (46 commits)
saner proc_get_inode() calling conventions
proc: avoid extra pde_put() in proc_fill_super()
fs: change return values from -EACCES to -EPERM
fs/exec.c: make bprm_mm_init() static
ocfs2/dlm: use GFP_ATOMIC inside a spin_lock
ocfs2: fix possible use-after-free with AIO
ocfs2: Fix oops in ocfs2_fast_symlink_readpage() code path
get_empty_filp()/alloc_file() leave both ->f_pos and ->f_version zero
target: writev() on single-element vector is pointless
export kernel_write(), convert open-coded instances
fs: encode_fh: return FILEID_INVALID if invalid fid_type
kill f_vfsmnt
vfs: kill FS_REVAL_DOT by adding a d_weak_revalidate dentry op
nfsd: handle vfs_getattr errors in acl protocol
switch vfs_getattr() to struct path
default SET_PERSONALITY() in linux/elf.h
ceph: prepopulate inodes only when request is aborted
d_hash_and_lookup(): export, switch open-coded instances
9p: switch v9fs_set_create_acl() to inode+fid, do it before d_instantiate()
9p: split dropping the acls from v9fs_set_create_acl()
...
the "punch hole" functionality for inodes that are not using extent
maps.
In the bug fix category, we fixed some races in the AIO and fstrim
code, and some potential NULL pointer dereferences and memory leaks in
error handling code paths.
In the optimization category, we fixed a performance regression in the
jbd2 layer introduced by commit d9b0193 (introduced in v3.0) which
shows up in the AIM7 benchmark. We also further optimized jbd2 by
minimize the amount of time that transaction handles are held active.
This patch series also features some additional enhancement of the
extent status tree, which is now used to cache extent information in a
more efficient/compact form than what we use on-disk.
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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 Theodore Ts'o:
"The one new feature added in this patch series is the ability to use
the "punch hole" functionality for inodes that are not using extent
maps.
In the bug fix category, we fixed some races in the AIO and fstrim
code, and some potential NULL pointer dereferences and memory leaks in
error handling code paths.
In the optimization category, we fixed a performance regression in the
jbd2 layer introduced by commit d9b01934d5 ("jbd: fix fsync() tid
wraparound bug", introduced in v3.0) which shows up in the AIM7
benchmark. We also further optimized jbd2 by minimize the amount of
time that transaction handles are held active.
This patch series also features some additional enhancement of the
extent status tree, which is now used to cache extent information in a
more efficient/compact form than what we use on-disk."
* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (65 commits)
ext4: fix free clusters calculation in bigalloc filesystem
ext4: no need to remove extent if len is 0 in ext4_es_remove_extent()
ext4: fix xattr block allocation/release with bigalloc
ext4: reclaim extents from extent status tree
ext4: adjust some functions for reclaiming extents from extent status tree
ext4: remove single extent cache
ext4: lookup block mapping in extent status tree
ext4: track all extent status in extent status tree
ext4: let ext4_ext_map_blocks return EXT4_MAP_UNWRITTEN flag
ext4: rename and improbe ext4_es_find_extent()
ext4: add physical block and status member into extent status tree
ext4: refine extent status tree
ext4: use ERR_PTR() abstraction for ext4_append()
ext4: refactor code to read directory blocks into ext4_read_dirblock()
ext4: add debugging context for warning in ext4_da_update_reserve_space()
ext4: use KERN_WARNING for warning messages
jbd2: use module parameters instead of debugfs for jbd_debug
ext4: use module parameters instead of debugfs for mballoc_debug
ext4: start handle at the last possible moment when creating inodes
ext4: fix the number of credits needed for acl ops with inline data
...
Create a helper function to check if a backing device requires stable
page writes and, if so, performs the necessary wait. Then, make it so
that all points in the memory manager that handle making pages writable
use the helper function. This should provide stable page write support
to most filesystems, while eliminating unnecessary waiting for devices
that don't require the feature.
Before this patchset, all filesystems would block, regardless of whether
or not it was necessary. ext3 would wait, but still generate occasional
checksum errors. The network filesystems were left to do their own
thing, so they'd wait too.
After this patchset, all the disk filesystems except ext3 and btrfs will
wait only if the hardware requires it. ext3 (if necessary) snapshots
pages instead of blocking, and btrfs provides its own bdi so the mm will
never wait. Network filesystems haven't been touched, so either they
provide their own stable page guarantees or they don't block at all.
The blocking behavior is back to what it was before 3.0 if you don't
have a disk requiring stable page writes.
Here's the result of using dbench to test latency on ext2:
3.8.0-rc3:
Operation Count AvgLat MaxLat
----------------------------------------
WriteX 109347 0.028 59.817
ReadX 347180 0.004 3.391
Flush 15514 29.828 287.283
Throughput 57.429 MB/sec 4 clients 4 procs max_latency=287.290 ms
3.8.0-rc3 + patches:
WriteX 105556 0.029 4.273
ReadX 335004 0.005 4.112
Flush 14982 30.540 298.634
Throughput 55.4496 MB/sec 4 clients 4 procs max_latency=298.650 ms
As you can see, the maximum write latency drops considerably with this
patch enabled. The other filesystems (ext3/ext4/xfs/btrfs) behave
similarly, but see the cover letter for those results.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Artem Bityutskiy <dedekind1@gmail.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Ron Minnich <rminnich@sandia.gov>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
After tracking all extent status, we already have a extent cache in
memory. Every time we want to lookup a block mapping, we can first
try to lookup it in extent status tree to avoid a potential disk I/O.
A new function called ext4_es_lookup_extent is defined to finish this
work. When we try to lookup a block mapping, we always call
ext4_map_blocks and/or ext4_da_map_blocks. So in these functions we
first try to lookup a block mapping in extent status tree.
A new flag EXT4_GET_BLOCKS_NO_PUT_HOLE is used in ext4_da_map_blocks
in order not to put a hole into extent status tree because this hole
will be converted to delayed extent in the tree immediately.
Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Jan kara <jack@suse.cz>
By recording the phycisal block and status, extent status tree is able
to track the status of every extents. When we call _map_blocks
functions to lookup an extent or create a new written/unwritten/delayed
extent, this extent will be inserted into extent status tree.
We don't load all extents from disk in alloc_inode() because it costs
too much memory, and if a file is opened and closed frequently it will
takes too much time to load all extent information. So currently when
we create/lookup an extent, this extent will be inserted into extent
status tree. Hence, the extent status tree may not comprehensively
contain all of the extents found in the file.
Here a condition we need to take care is that an extent might contains
unwritten and delayed status simultaneously because an extent is delayed
allocated and could be allocated by fallocate. At this time we need to
keep delayed status because later we need to update delayed reservation
space using it.
Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Jan kara <jack@suse.cz>
This commit lets ext4_ext_map_blocks return EXT4_MAP_UNWRITTEN flag
because in later commit ext4_map_blocks needs to use this flag to
determine the extent status.
Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
This commit adds two members in extent_status structure to let it record
physical block and extent status. Here es_pblk is used to record both
of them because physical block only has 48 bits. So extent status could
be stashed into it so that we can save some memory. Now written,
unwritten, delayed and hole are defined as status.
Due to new member is added into extent status tree, all interfaces need
to be adjusted.
Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Use ERR_PTR()/IS_ERR() abstraction instead of passing in a separate
pointer to an integer for the error code, as a code cleanup.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Print some additional debugging context to hopefully help to debug a
warning which is getting triggered by xfstests #74.
Also remove extraneous newlines from when printk's were converted to
ext4_warning() and ext4_msg().
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Some messages printed related to a WARN_ON(1) were printed using
KERN_NOTICE. Use KERN_WARNING or ext4_warning() instead so that
context related to the WARN_ON() is printed at the same printk warning
level (and log files, etc.)
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The grab_cache_page_write_begin() function can potentially sleep for a
long time, since it may need to do memory allocation which can block
if the system is under significant memory pressure, and because it may
be blocked on page writeback. If it does take a long time to grab the
page, it's better that we not hold an active jbd2 handle.
So grab a handle on the page first, and _then_ start the transaction
handle.
This commit fixes the following long transaction handle hold time:
postmark-2917 [000] .... 196.435786: jbd2_handle_stats: dev 254,32
tid 570 type 2 line_no 2541 interval 311 sync 0 requested_blocks 1
dirtied_blocks 0
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
So we can better understand what bits of ext4 are responsible for
long-running jbd2 handles, use jbd2__journal_start() so we can pass
context information for logging purposes.
The recommended way for finding the longer-running handles is:
T=/sys/kernel/debug/tracing
EVENT=$T/events/jbd2/jbd2_handle_stats
echo "interval > 5" > $EVENT/filter
echo 1 > $EVENT/enable
./run-my-fs-benchmark
cat $T/trace > /tmp/problem-handles
This will list handles that were active for longer than 20ms. Having
longer-running handles is bad, because a commit started at the wrong
time could stall for those 20+ milliseconds, which could delay an
fsync() or an O_SYNC operation. Here is an example line from the
trace file describing a handle which lived on for 311 jiffies, or over
1.2 seconds:
postmark-2917 [000] .... 196.435786: jbd2_handle_stats: dev 254,32
tid 570 type 2 line_no 2541 interval 311 sync 0 requested_blocks 1
dirtied_blocks 0
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Running AIO is pinning inode in memory using file reference. Once AIO
is completed using aio_complete(), file reference is put and inode can
be freed from memory. So we have to be sure that calling aio_complete()
is the last thing we do with the inode.
CC: stable@vger.kernel.org
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
So far ext4_writepage() skipped writing pages that had any delayed or
unwritten buffers attached. When blocksize < pagesize this breaks
data=ordered mode guarantees as we can have a page with one freshly
allocated buffer whose allocation is part of the committing
transaction and another buffer in the page which is delayed or
unwritten. So fix this problem by calling ext4_bio_writepage()
anyway. It will submit mapped buffers and leave others alone.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The argument b_size of mpage_add_bh_to_extent() was bogus since it was
always == blocksize (which we can easily derive from inode->i_blkbits).
Also second branch of condition:
if (nrblocks >= EXT4_MAX_TRANS_DATA) {
} else if ((nrblocks + (b_size >> mpd->inode->i_blkbits)) >
EXT4_MAX_TRANS_DATA) {
}
was never taken because (b_size >> mpd->inode->i_blkbits) == 1.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
ext4_writepage(), write_cache_pages_da(), and mpage_da_submit_io()
doesn't have to deal with the case when page doesn't have buffers. We
attach buffers to a page in ->write_begin() and ->page_mkwrite() which
covers all places where a page can become dirty.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
We don't support delayed allocation in data=journal mode. So checking for it in
mpage_da_submit_io() doesn't make really sence. If we ever decide to extend
delayed allocation support to data=journal mode, adding
__ext4_journalled_writepage() call will be the least of problems we have to
solve. Most likely we'd have to implement separate writepages call anyways
because we don't have transaction credits for writing more than a single page
so mapping of page buffers would have to be done differently.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Currently we sometimes used block_write_full_page() and sometimes
ext4_bio_write_page() for writeback (depending on mount options and call
path). Let's always use ext4_bio_write_page() to simplify things a bit.
Reviewed-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This patch add supports for indirect file support punching hole. It
is almost the same as ext4_ext_punch_hole. First, we invalidate all
pages between this hole, and then we try to deallocate all blocks of
this hole.
A recursive function is used to handle deallocation of blocks. In
this function, it iterates over the entries in inode's i_blocks or
indirect blocks, and try to free the block for each one of them.
After applying this patch, xfstest #255 will not pass w/o extent because
indirect-based file doesn't support unwritten extents.
Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This patch adds a tracepoint in ext4_punch_hole.
CC: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Because the function 'sb_getblk' seldomly fails to return NULL
value,it will be better to use 'unlikely' to optimize it.
Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The only reason for sb_getblk() failing is if it can't allocate the
buffer_head. So ENOMEM is more appropriate than EIO. In addition,
make sure that the file system is marked as being inconsistent if
sb_getblk() fails.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org
writeback_inodes_sb(_nr)_if_idle() is re-implemented by replacing down_read()
with down_read_trylock() because
- If ->s_umount is write locked, then the sb is not idle. That is
writeback_inodes_sb(_nr)_if_idle() needn't wait for the lock.
- writeback_inodes_sb(_nr)_if_idle() grabs s_umount lock when it want to start
writeback, it may bring us deadlock problem when doing umount. In order to
fix the problem, ext4 and btrfs implemented their own writeback functions
instead of writeback_inodes_sb(_nr)_if_idle(), but it introduced the redundant
code, it is better to implement a new writeback_inodes_sb(_nr)_if_idle().
The name of these two functions is cumbersome, so rename them to
try_to_writeback_inodes_sb(_nr).
This idea came from Christoph Hellwig.
Some code is from the patch of Kamal Mostafa.
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
We cannot wait for transaction commit in journal_unmap_buffer()
because we hold page lock which ranks below transaction start. We
solve the issue by bailing out of journal_unmap_buffer() and
jbd2_journal_invalidatepage() with -EBUSY. Caller is then responsible
for waiting for transaction commit to finish and try invalidation
again. Since the issue can happen only for page stradding i_size, it
is simple enough to manually call jbd2_journal_invalidatepage() for
such page from ext4_setattr(), check the return value and wait if
necessary.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
In data=journal mode we don't need delalloc or DIO handling in invalidatepage
and similarly in other modes we don't need the journal handling. So split
invalidatepage implementations.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
For delayed allocation mode, we write to inline data if the file
is small enough. And in case of we write to some offset larger
than the inline size, the 1st page is dirtied, so that
ext4_da_writepages can handle the conversion. When the 1st page
is initialized with blocks, the inline part is removed.
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
