Commit Graph

156 Commits

Author SHA1 Message Date
Josef Bacik
64708539cd btrfs: use btrfs_inode_lock/btrfs_inode_unlock inode lock helpers
A few places we intermix btrfs_inode_lock with a inode_unlock, and some
places we just use inode_lock/inode_unlock instead of btrfs_inode_lock.

None of these places are using this incorrectly, but as we adjust some
of these callers it would be nice to keep everything consistent, so
convert everybody to use btrfs_inode_lock/btrfs_inode_unlock.

Reviewed-by: Filipe Manana <fdmanana@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>
2021-04-19 17:25:15 +02:00
Nikolay Borisov
98686ffc71 btrfs: simplify code flow in btrfs_delayed_inode_reserve_metadata
btrfs_block_rsv_add can return only ENOSPC since it's called with
NO_FLUSH modifier. This so simplify the logic in
btrfs_delayed_inode_reserve_metadata to exploit this invariant.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add assert and comment ]
Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19 17:25:15 +02:00
Nikolay Borisov
8e3c9d3cf8 btrfs: remove btrfs_inode parameter from btrfs_delayed_inode_reserve_metadata
It's only used for tracepoint to obtain the inode number, but we already
have the ino from btrfs_delayed_node::inode_id.

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>
2021-04-19 17:25:14 +02:00
Nikolay Borisov
4d14c5cde5 btrfs: don't flush from btrfs_delayed_inode_reserve_metadata
Calling btrfs_qgroup_reserve_meta_prealloc from
btrfs_delayed_inode_reserve_metadata can result in flushing delalloc
while holding a transaction and delayed node locks. This is deadlock
prone. In the past multiple commits:

 * ae5e070eac ("btrfs: qgroup: don't try to wait flushing if we're
already holding a transaction")

 * 6f23277a49 ("btrfs: qgroup: don't commit transaction when we already
 hold the handle")

Tried to solve various aspects of this but this was always a
whack-a-mole game. Unfortunately those 2 fixes don't solve a deadlock
scenario involving btrfs_delayed_node::mutex. Namely, one thread
can call btrfs_dirty_inode as a result of reading a file and modifying
its atime:

  PID: 6963   TASK: ffff8c7f3f94c000  CPU: 2   COMMAND: "test"
  #0  __schedule at ffffffffa529e07d
  #1  schedule at ffffffffa529e4ff
  #2  schedule_timeout at ffffffffa52a1bdd
  #3  wait_for_completion at ffffffffa529eeea             <-- sleeps with delayed node mutex held
  #4  start_delalloc_inodes at ffffffffc0380db5
  #5  btrfs_start_delalloc_snapshot at ffffffffc0393836
  #6  try_flush_qgroup at ffffffffc03f04b2
  #7  __btrfs_qgroup_reserve_meta at ffffffffc03f5bb6     <-- tries to reserve space and starts delalloc inodes.
  #8  btrfs_delayed_update_inode at ffffffffc03e31aa      <-- acquires delayed node mutex
  #9  btrfs_update_inode at ffffffffc0385ba8
 #10  btrfs_dirty_inode at ffffffffc038627b               <-- TRANSACTIION OPENED
 #11  touch_atime at ffffffffa4cf0000
 #12  generic_file_read_iter at ffffffffa4c1f123
 #13  new_sync_read at ffffffffa4ccdc8a
 #14  vfs_read at ffffffffa4cd0849
 #15  ksys_read at ffffffffa4cd0bd1
 #16  do_syscall_64 at ffffffffa4a052eb
 #17  entry_SYSCALL_64_after_hwframe at ffffffffa540008c

This will cause an asynchronous work to flush the delalloc inodes to
happen which can try to acquire the same delayed_node mutex:

  PID: 455    TASK: ffff8c8085fa4000  CPU: 5   COMMAND: "kworker/u16:30"
  #0  __schedule at ffffffffa529e07d
  #1  schedule at ffffffffa529e4ff
  #2  schedule_preempt_disabled at ffffffffa529e80a
  #3  __mutex_lock at ffffffffa529fdcb                    <-- goes to sleep, never wakes up.
  #4  btrfs_delayed_update_inode at ffffffffc03e3143      <-- tries to acquire the mutex
  #5  btrfs_update_inode at ffffffffc0385ba8              <-- this is the same inode that pid 6963 is holding
  #6  cow_file_range_inline.constprop.78 at ffffffffc0386be7
  #7  cow_file_range at ffffffffc03879c1
  #8  btrfs_run_delalloc_range at ffffffffc038894c
  #9  writepage_delalloc at ffffffffc03a3c8f
 #10  __extent_writepage at ffffffffc03a4c01
 #11  extent_write_cache_pages at ffffffffc03a500b
 #12  extent_writepages at ffffffffc03a6de2
 #13  do_writepages at ffffffffa4c277eb
 #14  __filemap_fdatawrite_range at ffffffffa4c1e5bb
 #15  btrfs_run_delalloc_work at ffffffffc0380987         <-- starts running delayed nodes
 #16  normal_work_helper at ffffffffc03b706c
 #17  process_one_work at ffffffffa4aba4e4
 #18  worker_thread at ffffffffa4aba6fd
 #19  kthread at ffffffffa4ac0a3d
 #20  ret_from_fork at ffffffffa54001ff

To fully address those cases the complete fix is to never issue any
flushing while holding the transaction or the delayed node lock. This
patch achieves it by calling qgroup_reserve_meta directly which will
either succeed without flushing or will fail and return -EDQUOT. In the
latter case that return value is going to be propagated to
btrfs_dirty_inode which will fallback to start a new transaction. That's
fine as the majority of time we expect the inode will have
BTRFS_DELAYED_NODE_INODE_DIRTY flag set which will result in directly
copying the in-memory state.

Fixes: c53e965360 ("btrfs: qgroup: try to flush qgroup space when we get -EDQUOT")
CC: stable@vger.kernel.org # 5.10+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2021-03-02 17:17:09 +01:00
Nikolay Borisov
0f9c03d824 btrfs: free correct amount of space in btrfs_delayed_inode_reserve_metadata
Following commit f218ea6c47 ("btrfs: delayed-inode: Remove wrong
qgroup meta reservation calls") this function now reserves num_bytes,
rather than the fixed amount of nodesize. As such this requires the
same amount to be freed in case of failure. Fix this by adjusting
the amount we are freeing.

Fixes: f218ea6c47 ("btrfs: delayed-inode: Remove wrong qgroup meta reservation calls")
CC: stable@vger.kernel.org # 4.19+
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>
2021-03-02 16:56:04 +01:00
Abaci Team
a4559e6f6f btrfs: simplify condition in __btrfs_run_delayed_items
Fix the following coccicheck warnings:

./fs/btrfs/delayed-inode.c:1157:39-41: WARNING !A || A && B is
equivalent to !A || B.

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Suggested-by: Jiapeng Zhong <oswb@linux.alibaba.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Abaci Team <abaci-bugfix@linux.alibaba.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2021-02-08 22:58:59 +01:00
Nikolay Borisov
f3fbcaef59 btrfs: make btrfs_delayed_update_inode take btrfs_inode
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>
2020-12-08 15:54:10 +01:00
Josef Bacik
b9729ce014 btrfs: locking: rip out path->leave_spinning
We no longer distinguish between blocking and spinning, so rip out all
this code.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-12-08 15:54:02 +01:00
Josef Bacik
ac5887c8e0 btrfs: locking: remove all the blocking helpers
Now that we're using a rw_semaphore we no longer need to indicate if a
lock is blocking or not, nor do we need to flip the entire path from
blocking to spinning.  Remove these helpers and all the places they are
called.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-12-08 15:54:01 +01:00
Nikolay Borisov
fc0d82e103 btrfs: sink total_data parameter in setup_items_for_insert
That parameter can easily be derived based on the "data_size" and "nr"
parameters exploit this fact to simply the function's signature. No
functional changes.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
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>
2020-10-07 12:13:18 +02:00
Nikolay Borisov
3dc9dc8969 btrfs: eliminate total_size parameter from setup_items_for_insert
The value of this argument can be derived from the total_data as it's
simply the value of the data size + size of btrfs_items being touched.
Move the parameter calculation inside the function. This results in a
simpler interface and also a minor size reduction:

./scripts/bloat-o-meter ctree.original fs/btrfs/ctree.o
add/remove: 0/0 grow/shrink: 0/3 up/down: 0/-34 (-34)
Function                                     old     new   delta
btrfs_duplicate_item                         260     259      -1
setup_items_for_insert                      1200    1190     -10
btrfs_insert_empty_items                     177     154     -23

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
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>
2020-10-07 12:13:18 +02:00
Qu Wenruo
b4c5d8fdff btrfs: qgroup: fix wrong qgroup metadata reserve for delayed inode
For delayed inode facility, qgroup metadata is reserved for it, and
later freed.

However we're freeing more bytes than we reserved.
In btrfs_delayed_inode_reserve_metadata():

	num_bytes = btrfs_calc_metadata_size(fs_info, 1);
	...
		ret = btrfs_qgroup_reserve_meta_prealloc(root,
				fs_info->nodesize, true);
		...
		if (!ret) {
			node->bytes_reserved = num_bytes;

But in btrfs_delayed_inode_release_metadata():

	if (qgroup_free)
		btrfs_qgroup_free_meta_prealloc(node->root,
				node->bytes_reserved);
	else
		btrfs_qgroup_convert_reserved_meta(node->root,
				node->bytes_reserved);

This means, we're always releasing more qgroup metadata rsv than we have
reserved.

This won't trigger selftest warning, as btrfs qgroup metadata rsv has
extra protection against cases like quota enabled half-way.

But we still need to fix this problem any way.

This patch will use the same num_bytes for qgroup metadata rsv so we
could handle it correctly.

Fixes: f218ea6c47 ("btrfs: delayed-inode: Remove wrong qgroup meta reservation calls")
CC: stable@vger.kernel.org # 4.19+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-10-07 12:12:13 +02:00
Josef Bacik
351cbf6e44 btrfs: use nofs allocations for running delayed items
Zygo reported the following lockdep splat while testing the balance
patches

======================================================
WARNING: possible circular locking dependency detected
5.6.0-c6f0579d496a+ #53 Not tainted
------------------------------------------------------
kswapd0/1133 is trying to acquire lock:
ffff888092f622c0 (&delayed_node->mutex){+.+.}, at: __btrfs_release_delayed_node+0x7c/0x5b0

but task is already holding lock:
ffffffff8fc5f860 (fs_reclaim){+.+.}, at: __fs_reclaim_acquire+0x5/0x30

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (fs_reclaim){+.+.}:
       fs_reclaim_acquire.part.91+0x29/0x30
       fs_reclaim_acquire+0x19/0x20
       kmem_cache_alloc_trace+0x32/0x740
       add_block_entry+0x45/0x260
       btrfs_ref_tree_mod+0x6e2/0x8b0
       btrfs_alloc_tree_block+0x789/0x880
       alloc_tree_block_no_bg_flush+0xc6/0xf0
       __btrfs_cow_block+0x270/0x940
       btrfs_cow_block+0x1ba/0x3a0
       btrfs_search_slot+0x999/0x1030
       btrfs_insert_empty_items+0x81/0xe0
       btrfs_insert_delayed_items+0x128/0x7d0
       __btrfs_run_delayed_items+0xf4/0x2a0
       btrfs_run_delayed_items+0x13/0x20
       btrfs_commit_transaction+0x5cc/0x1390
       insert_balance_item.isra.39+0x6b2/0x6e0
       btrfs_balance+0x72d/0x18d0
       btrfs_ioctl_balance+0x3de/0x4c0
       btrfs_ioctl+0x30ab/0x44a0
       ksys_ioctl+0xa1/0xe0
       __x64_sys_ioctl+0x43/0x50
       do_syscall_64+0x77/0x2c0
       entry_SYSCALL_64_after_hwframe+0x49/0xbe

-> #0 (&delayed_node->mutex){+.+.}:
       __lock_acquire+0x197e/0x2550
       lock_acquire+0x103/0x220
       __mutex_lock+0x13d/0xce0
       mutex_lock_nested+0x1b/0x20
       __btrfs_release_delayed_node+0x7c/0x5b0
       btrfs_remove_delayed_node+0x49/0x50
       btrfs_evict_inode+0x6fc/0x900
       evict+0x19a/0x2c0
       dispose_list+0xa0/0xe0
       prune_icache_sb+0xbd/0xf0
       super_cache_scan+0x1b5/0x250
       do_shrink_slab+0x1f6/0x530
       shrink_slab+0x32e/0x410
       shrink_node+0x2a5/0xba0
       balance_pgdat+0x4bd/0x8a0
       kswapd+0x35a/0x800
       kthread+0x1e9/0x210
       ret_from_fork+0x3a/0x50

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(fs_reclaim);
                               lock(&delayed_node->mutex);
                               lock(fs_reclaim);
  lock(&delayed_node->mutex);

 *** DEADLOCK ***

3 locks held by kswapd0/1133:
 #0: ffffffff8fc5f860 (fs_reclaim){+.+.}, at: __fs_reclaim_acquire+0x5/0x30
 #1: ffffffff8fc380d8 (shrinker_rwsem){++++}, at: shrink_slab+0x1e8/0x410
 #2: ffff8881e0e6c0e8 (&type->s_umount_key#42){++++}, at: trylock_super+0x1b/0x70

stack backtrace:
CPU: 2 PID: 1133 Comm: kswapd0 Not tainted 5.6.0-c6f0579d496a+ #53
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
Call Trace:
 dump_stack+0xc1/0x11a
 print_circular_bug.isra.38.cold.57+0x145/0x14a
 check_noncircular+0x2a9/0x2f0
 ? print_circular_bug.isra.38+0x130/0x130
 ? stack_trace_consume_entry+0x90/0x90
 ? save_trace+0x3cc/0x420
 __lock_acquire+0x197e/0x2550
 ? btrfs_inode_clear_file_extent_range+0x9b/0xb0
 ? register_lock_class+0x960/0x960
 lock_acquire+0x103/0x220
 ? __btrfs_release_delayed_node+0x7c/0x5b0
 __mutex_lock+0x13d/0xce0
 ? __btrfs_release_delayed_node+0x7c/0x5b0
 ? __asan_loadN+0xf/0x20
 ? pvclock_clocksource_read+0xeb/0x190
 ? __btrfs_release_delayed_node+0x7c/0x5b0
 ? mutex_lock_io_nested+0xc20/0xc20
 ? __kasan_check_read+0x11/0x20
 ? check_chain_key+0x1e6/0x2e0
 mutex_lock_nested+0x1b/0x20
 ? mutex_lock_nested+0x1b/0x20
 __btrfs_release_delayed_node+0x7c/0x5b0
 btrfs_remove_delayed_node+0x49/0x50
 btrfs_evict_inode+0x6fc/0x900
 ? btrfs_setattr+0x840/0x840
 ? do_raw_spin_unlock+0xa8/0x140
 evict+0x19a/0x2c0
 dispose_list+0xa0/0xe0
 prune_icache_sb+0xbd/0xf0
 ? invalidate_inodes+0x310/0x310
 super_cache_scan+0x1b5/0x250
 do_shrink_slab+0x1f6/0x530
 shrink_slab+0x32e/0x410
 ? do_shrink_slab+0x530/0x530
 ? do_shrink_slab+0x530/0x530
 ? __kasan_check_read+0x11/0x20
 ? mem_cgroup_protected+0x13d/0x260
 shrink_node+0x2a5/0xba0
 balance_pgdat+0x4bd/0x8a0
 ? mem_cgroup_shrink_node+0x490/0x490
 ? _raw_spin_unlock_irq+0x27/0x40
 ? finish_task_switch+0xce/0x390
 ? rcu_read_lock_bh_held+0xb0/0xb0
 kswapd+0x35a/0x800
 ? _raw_spin_unlock_irqrestore+0x4c/0x60
 ? balance_pgdat+0x8a0/0x8a0
 ? finish_wait+0x110/0x110
 ? __kasan_check_read+0x11/0x20
 ? __kthread_parkme+0xc6/0xe0
 ? balance_pgdat+0x8a0/0x8a0
 kthread+0x1e9/0x210
 ? kthread_create_worker_on_cpu+0xc0/0xc0
 ret_from_fork+0x3a/0x50

This is because we hold that delayed node's mutex while doing tree
operations.  Fix this by just wrapping the searches in nofs.

CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-25 16:26:00 +01:00
Nikolay Borisov
63f018be57 btrfs: Remove __ prefix from btrfs_block_rsv_release
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>
2020-03-23 17:01:55 +01:00
David Sterba
bf31f87f71 btrfs: add wrapper for transaction abort predicate
The status of aborted transaction can change between calls and it needs
to be accessed by READ_ONCE. Add a helper that also wraps the unlikely
hint.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:34 +01:00
Josef Bacik
9ddc959e80 btrfs: use the file extent tree infrastructure
We want to use this everywhere we modify the file extent items
permanently.  These include:

  1) Inserting new file extents for writes and prealloc extents.
  2) Truncating inode items.
  3) btrfs_cont_expand().
  4) Insert inline extents.
  5) Insert new extents from log replay.
  6) Insert a new extent for clone, as it could be past i_size.
  7) Hole punching

For hole punching in particular it might seem it's not necessary because
anybody extending would use btrfs_cont_expand, however there is a corner
that still can give us trouble.  Start with an empty file and

fallocate KEEP_SIZE 1M-2M

We now have a 0 length file, and a hole file extent from 0-1M, and a
prealloc extent from 1M-2M.  Now

punch 1M-1.5M

Because this is past i_size we have

[HOLE EXTENT][ NOTHING ][PREALLOC]
[0        1M][1M   1.5M][1.5M  2M]

with an i_size of 0.  Now if we pwrite 0-1.5M we'll increas our i_size
to 1.5M, but our disk_i_size is still 0 until the ordered extent
completes.

However if we now immediately truncate 2M on the file we'll just call
btrfs_cont_expand(inode, 1.5M, 2M), since our old i_size is 1.5M.  If we
commit the transaction here and crash we'll expose the gap.

To fix this we need to clear the file extent mapping for the range that
we punched but didn't insert a corresponding file extent for.  This will
mean the truncate will only get an disk_i_size set to 1M if we crash
before the finish ordered io happens.

I've written an xfstest to reproduce the problem and validate this fix.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:24 +01:00
Josef Bacik
baf320b9d5 btrfs: use refcount_inc_not_zero in kill_all_nodes
We hit the following warning while running down a different problem

[ 6197.175850] ------------[ cut here ]------------
[ 6197.185082] refcount_t: underflow; use-after-free.
[ 6197.194704] WARNING: CPU: 47 PID: 966 at lib/refcount.c:190 refcount_sub_and_test_checked+0x53/0x60
[ 6197.521792] Call Trace:
[ 6197.526687]  __btrfs_release_delayed_node+0x76/0x1c0
[ 6197.536615]  btrfs_kill_all_delayed_nodes+0xec/0x130
[ 6197.546532]  ? __btrfs_btree_balance_dirty+0x60/0x60
[ 6197.556482]  btrfs_clean_one_deleted_snapshot+0x71/0xd0
[ 6197.566910]  cleaner_kthread+0xfa/0x120
[ 6197.574573]  kthread+0x111/0x130
[ 6197.581022]  ? kthread_create_on_node+0x60/0x60
[ 6197.590086]  ret_from_fork+0x1f/0x30
[ 6197.597228] ---[ end trace 424bb7ae00509f56 ]---

This is because the free side drops the ref without the lock, and then
takes the lock if our refcount is 0.  So you can have nodes on the tree
that have a refcount of 0.  Fix this by zero'ing out that element in our
temporary array so we don't try to kill it again.

CC: stable@vger.kernel.org # 4.14+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add comment ]
Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-18 12:46:51 +01:00
David Sterba
1f95ec012c btrfs: move btrfs_unlock_up_safe to other locking functions
The function belongs to the family of locking functions, so move it
there. The 'noinline' keyword is dropped as it's now an exported
function that does not need it.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-18 12:46:49 +01:00
Omar Sandoval
a0cac0ec96 btrfs: get rid of unique workqueue helper functions
Commit 9e0af23764 ("Btrfs: fix task hang under heavy compressed
write") worked around the issue that a recycled work item could get a
false dependency on the original work item due to how the workqueue code
guarantees non-reentrancy. It did so by giving different work functions
to different types of work.

However, the fixes in the previous few patches are more complete, as
they prevent a work item from being recycled at all (except for a tiny
window that the kernel workqueue code handles for us). This obsoletes
the previous fix, so we don't need the unique helpers for correctness.
The only other reason to keep them would be so they show up in stack
traces, but they always seem to be optimized to a tail call, so they
don't show up anyways. So, let's just get rid of the extra indirection.

While we're here, rename normal_work_helper() to the more informative
btrfs_work_helper().

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-18 12:46:48 +01:00
David Sterba
602cbe91fb btrfs: move cond_wake_up functions out of ctree
The file ctree.h serves as a header for everything and has become quite
bloated. Split some helpers that are generic and create a new file that
should be the catch-all for code that's not btrfs-specific.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09 14:59:15 +02:00
Josef Bacik
bcacf5f3f9 btrfs: only reserve metadata_size for inodes
Historically we reserved worst case for every btree operation, and
generally speaking we want to do that in cases where it could be the
worst case.  However for updating inodes we know the inode items are
already in the tree, so it will only be an update operation and never an
insert operation.  This allows us to always reserve only the
metadata_size amount for inode updates rather than the
insert_metadata_size amount.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09 14:59:13 +02:00
Josef Bacik
2bd36e7b4f btrfs: rename the btrfs_calc_*_metadata_size helpers
btrfs_calc_trunc_metadata_size differs from trans_metadata_size in that
it doesn't take into account any splitting at the levels, because
truncate will never split nodes.  However truncate _and_ changing will
never split nodes, so rename btrfs_calc_trunc_metadata_size to
btrfs_calc_metadata_size.  Also btrfs_calc_trans_metadata_size is purely
for inserting items, so rename this to btrfs_calc_insert_metadata_size.
Making these clearer will help when I start using them differently in
upcoming patches.

Reviewed-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>
2019-09-09 14:59:13 +02:00
Qu Wenruo
933c22a751 btrfs: delayed-inode: Kill the BUG_ON() in btrfs_delete_delayed_dir_index()
There is one report of fuzzed image which leads to BUG_ON() in
btrfs_delete_delayed_dir_index().

Although that fuzzed image can already be addressed by enhanced
extent-tree error handler, it's still better to hunt down more BUG_ON().

This patch will hunt down two BUG_ON()s in
btrfs_delete_delayed_dir_index():
- One for error from btrfs_delayed_item_reserve_metadata()
  Instead of BUG_ON(), we output an error message and free the item.
  And return the error.
  All callers of this function handles the error by aborting current
  trasaction.

- One for possible EEXIST from __btrfs_add_delayed_deletion_item()
  That function can return -EEXIST.
  We already have a good enough error message for that, only need to
  clean up the reserved metadata space and allocated item.

To help above cleanup, also modifiy __btrfs_remove_delayed_item() called
in btrfs_release_delayed_item(), to skip unassociated item.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=203253
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09 14:59:01 +02:00
David Sterba
e902baac65 btrfs: get fs_info from eb in btrfs_leaf_free_space
We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:30 +02:00
Phillip Potter
7d157c3d48 btrfs: use common file type conversion
Deduplicate the btrfs file type conversion implementation - file systems
that use the same file types as defined by POSIX do not need to define
their own versions and can use the common helper functions decared in
fs_types.h and implemented in fs_types.c

Common implementation can be found via commit:
bbe7449e25 "fs: common implementation of file type"

Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Phillip Potter <phil@philpotter.co.uk>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:29 +02:00
Liu Bo
5239834016 Btrfs: kill btrfs_clear_path_blocking
Btrfs's btree locking has two modes, spinning mode and blocking mode,
while searching btree, locking is always acquired in spinning mode and
then converted to blocking mode if necessary, and in some hot paths we may
switch the locking back to spinning mode by btrfs_clear_path_blocking().

When acquiring locks, both of reader and writer need to wait for blocking
readers and writers to complete before doing read_lock()/write_lock().

The problem is that btrfs_clear_path_blocking() needs to switch nodes
in the path to blocking mode at first (by btrfs_set_path_blocking) to
make lockdep happy before doing its actual clearing blocking job.

When switching to blocking mode from spinning mode, it consists of

step 1) bumping up blocking readers counter and
step 2) read_unlock()/write_unlock(),

this has caused serious ping-pong effect if there're a great amount of
concurrent readers/writers, as waiters will be woken up and go to
sleep immediately.

1) Killing this kind of ping-pong results in a big improvement in my 1600k
files creation script,

MNT=/mnt/btrfs
mkfs.btrfs -f /dev/sdf
mount /dev/def $MNT
time fsmark  -D  10000  -S0  -n  100000  -s  0  -L  1 -l /tmp/fs_log.txt \
        -d  $MNT/0  -d  $MNT/1 \
        -d  $MNT/2  -d  $MNT/3 \
        -d  $MNT/4  -d  $MNT/5 \
        -d  $MNT/6  -d  $MNT/7 \
        -d  $MNT/8  -d  $MNT/9 \
        -d  $MNT/10  -d  $MNT/11 \
        -d  $MNT/12  -d  $MNT/13 \
        -d  $MNT/14  -d  $MNT/15

w/o patch:
real    2m27.307s
user    0m12.839s
sys     13m42.831s

w/ patch:
real    1m2.273s
user    0m15.802s
sys     8m16.495s

1.1) latency histogram from funclatency[1]

Overall with the patch, there're ~50% less write lock acquisition and
the 95% max latency that write lock takes also reduces to ~100ms from
>500ms.

--------------------------------------------
w/o patch:
--------------------------------------------
Function = btrfs_tree_lock
     msecs               : count     distribution
         0 -> 1          : 2385222  |****************************************|
         2 -> 3          : 37147    |                                        |
         4 -> 7          : 20452    |                                        |
         8 -> 15         : 13131    |                                        |
        16 -> 31         : 3877     |                                        |
        32 -> 63         : 3900     |                                        |
        64 -> 127        : 2612     |                                        |
       128 -> 255        : 974      |                                        |
       256 -> 511        : 165      |                                        |
       512 -> 1023       : 13       |                                        |

Function = btrfs_tree_read_lock
     msecs               : count     distribution
         0 -> 1          : 6743860  |****************************************|
         2 -> 3          : 2146     |                                        |
         4 -> 7          : 190      |                                        |
         8 -> 15         : 38       |                                        |
        16 -> 31         : 4        |                                        |

--------------------------------------------
w/ patch:
--------------------------------------------
Function = btrfs_tree_lock
     msecs               : count     distribution
         0 -> 1          : 1318454  |****************************************|
         2 -> 3          : 6800     |                                        |
         4 -> 7          : 3664     |                                        |
         8 -> 15         : 2145     |                                        |
        16 -> 31         : 809      |                                        |
        32 -> 63         : 219      |                                        |
        64 -> 127        : 10       |                                        |

Function = btrfs_tree_read_lock
     msecs               : count     distribution
         0 -> 1          : 6854317  |****************************************|
         2 -> 3          : 2383     |                                        |
         4 -> 7          : 601      |                                        |
         8 -> 15         : 92       |                                        |

2) dbench also proves the improvement,
dbench -t 120 -D /mnt/btrfs 16

w/o patch:
Throughput 158.363 MB/sec

w/ patch:
Throughput 449.52 MB/sec

3) xfstests didn't show any additional failures.

One thing to note is that callers may set path->leave_spinning to have
all nodes in the path stay in spinning mode, which means callers are
ready to not sleep before releasing the path, but it won't cause
problems if they don't want to sleep in blocking mode.

[1]: https://github.com/iovisor/bcc/blob/master/tools/funclatency.py

Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15 17:23:38 +02:00
Liu Bo
03a1d4c891 Btrfs: delayed-inode: use rb_first_cached for ins_root and del_root
rb_first_cached() trades an extra pointer "leftmost" for doing the same job as
rb_first() but in O(1).

Functions manipulating delayed_item need to get the first entry, this converts
it to use rb_first_cached().

For more details about the optimization see patch "Btrfs: delayed-refs:
use rb_first_cached for href_root".

Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15 17:23:33 +02:00
Misono Tomohiro
4fd786e6c3 btrfs: Remove 'objectid' member from struct btrfs_root
There are two members in struct btrfs_root which indicate root's
objectid: objectid and root_key.objectid.

They are both set to the same value in __setup_root():

  static void __setup_root(struct btrfs_root *root,
                           struct btrfs_fs_info *fs_info,
                           u64 objectid)
  {
    ...
    root->objectid = objectid;
    ...
    root->root_key.objectid = objecitd;
    ...
  }

and not changed to other value after initialization.

grep in btrfs directory shows both are used in many places:
  $ grep -rI "root->root_key.objectid" | wc -l
  133
  $ grep -rI "root->objectid" | wc -l
  55
 (4.17, inc. some noise)

It is confusing to have two similar variable names and it seems
that there is no rule about which should be used in a certain case.

Since ->root_key itself is needed for tree reloc tree, let's remove
'objecitd' member and unify code to use ->root_key.objectid in all places.

Signed-off-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15 17:23:25 +02:00
Lu Fengqi
3a58417486 btrfs: switch update_size to bool in btrfs_block_rsv_migrate and btrfs_rsv_add_bytes
Using true and false here is closer to the expected semantic than using
0 and 1.  No functional change.

Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15 17:23:25 +02:00
Lu Fengqi
9add29457a btrfs: Remove fs_info from btrfs_delete_delayed_dir_index
It can be referenced from the passed transaction handle.

Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06 13:13:00 +02:00
Lu Fengqi
4465c8b422 btrfs: Remove fs_info from btrfs_insert_delayed_dir_index
It can be referenced from the passed transaction handle.

Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06 13:13:00 +02:00
David Sterba
3ffbd68c48 btrfs: simplify pointer chasing of local fs_info variables
Functions that get btrfs inode can simply reach the fs_info by
dereferencing the root and this looks a bit more straightforward
compared to the btrfs_sb(...) indirection.

If the transaction handle is available and not NULL it's used instead.

Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06 13:12:43 +02:00
David Sterba
093258e6eb btrfs: replace waitqueue_actvie with cond_wake_up
Use the wrappers and reduce the amount of low-level details about the
waitqueue management.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28 18:23:09 +02:00
Qu Wenruo
f218ea6c47 btrfs: delayed-inode: Remove wrong qgroup meta reservation calls
Commit 4f5427ccce ("btrfs: delayed-inode: Use new qgroup meta rsv for
delayed inode and item") merged into mainline was not latest version
submitted to the mail list in Dec 2017.

Which lacks the following fixes:

1) Remove btrfs_qgroup_convert_reserved_meta() call in
   btrfs_delayed_item_release_metadata()
2) Remove btrfs_qgroup_reserve_meta_prealloc() call in
   btrfs_delayed_inode_reserve_metadata()

Those fixes will resolve unexpected EDQUOT problems.

Fixes: 4f5427ccce ("btrfs: delayed-inode: Use new qgroup meta rsv for delayed inode and item")
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-04-18 16:46:55 +02:00
David Sterba
c1d7c514f7 btrfs: replace GPL boilerplate by SPDX -- sources
Remove GPL boilerplate text (long, short, one-line) and keep the rest,
ie. personal, company or original source copyright statements. Add the
SPDX header.

Signed-off-by: David Sterba <dsterba@suse.com>
2018-04-12 16:29:51 +02:00
Qu Wenruo
4f5427ccce btrfs: delayed-inode: Use new qgroup meta rsv for delayed inode and item
Quite similar for delalloc, some modification to delayed-inode and
delayed-item reservation.  Also needs extra parameter for release case
to distinguish normal release and error release.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-31 02:01:03 +02:00
David Sterba
e67c718b5b btrfs: add more __cold annotations
The __cold functions are placed to a special section, as they're
expected to be called rarely. This could help i-cache prefetches or help
compiler to decide which branches are more/less likely to be taken
without any other annotations needed.

Though we can't add more __exit annotations, it's still possible to add
__cold (that's also added with __exit). That way the following function
categories are tagged:

- printf wrappers, error messages
- exit helpers

Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-26 15:09:39 +02:00
Nikolay Borisov
e5c304e651 btrfs: Don't pass fs_info to btrfs_run_delayed_items/_nr
We already pass the transaction which has a reference to the fs_info,
so use that. No functional changes.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-26 15:09:31 +02:00
Nikolay Borisov
b84acab38f btrfs: Don't pass fs_info to __btrfs_run_delayed_items
We already pass the transaction handle, which contains a refrence to
the fs_info so grab it from there. No functional changes.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-26 15:09:31 +02:00
Linus Torvalds
31466f3ed7 for-4.16-tag
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Merge tag 'for-4.16-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs updates from David Sterba:
 "Features or user visible changes:

   - fallocate: implement zero range mode

   - avoid losing data raid profile when deleting a device

   - tree item checker: more checks for directory items and xattrs

  Notable fixes:

   - raid56 recovery: don't use cached stripes, that could be
     potentially changed and a later RMW or recovery would lead to
     corruptions or failures

   - let raid56 try harder to rebuild damaged data, reading from all
     stripes if necessary

   - fix scrub to repair raid56 in a similar way as in the case above

  Other:

   - cleanups: device freeing, removed some call indirections, redundant
     bio_put/_get, unused parameters, refactorings and renames

   - RCU list traversal fixups

   - simplify mount callchain, remove recursing back when mounting a
     subvolume

   - plug for fsync, may improve bio merging on multiple devices

   - compression heurisic: replace heap sort with radix sort, gains some
     performance

   - add extent map selftests, buffered write vs dio"

* tag 'for-4.16-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (155 commits)
  btrfs: drop devid as device_list_add() arg
  btrfs: get device pointer from device_list_add()
  btrfs: set the total_devices in device_list_add()
  btrfs: move pr_info into device_list_add
  btrfs: make btrfs_free_stale_devices() to match the path
  btrfs: rename btrfs_free_stale_devices() arg to skip_dev
  btrfs: make btrfs_free_stale_devices() argument optional
  btrfs: make btrfs_free_stale_device() to iterate all stales
  btrfs: no need to check for btrfs_fs_devices::seeding
  btrfs: Use IS_ALIGNED in btrfs_truncate_block instead of opencoding it
  Btrfs: noinline merge_extent_mapping
  Btrfs: add WARN_ONCE to detect unexpected error from merge_extent_mapping
  Btrfs: extent map selftest: dio write vs dio read
  Btrfs: extent map selftest: buffered write vs dio read
  Btrfs: add extent map selftests
  Btrfs: move extent map specific code to extent_map.c
  Btrfs: add helper for em merge logic
  Btrfs: fix unexpected EEXIST from btrfs_get_extent
  Btrfs: fix incorrect block_len in merge_extent_mapping
  btrfs: Remove unused readahead spinlock
  ...
2018-01-29 14:04:23 -08:00
Linus Torvalds
a4b7fd7d34 inode->i_version rework for v4.16
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Merge tag 'iversion-v4.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux

Pull inode->i_version rework from Jeff Layton:
 "This pile of patches is a rework of the inode->i_version field. We
  have traditionally incremented that field on every inode data or
  metadata change. Typically this increment needs to be logged on disk
  even when nothing else has changed, which is rather expensive.

  It turns out though that none of the consumers of that field actually
  require this behavior. The only real requirement for all of them is
  that it be different iff the inode has changed since the last time the
  field was checked.

  Given that, we can optimize away most of the i_version increments and
  avoid dirtying inode metadata when the only change is to the i_version
  and no one is querying it. Queries of the i_version field are rather
  rare, so we can help write performance under many common workloads.

  This patch series converts existing accesses of the i_version field to
  a new API, and then converts all of the in-kernel filesystems to use
  it. The last patch in the series then converts the backend
  implementation to a scheme that optimizes away a large portion of the
  metadata updates when no one is looking at it.

  In my own testing this series significantly helps performance with
  small I/O sizes. I also got this email for Christmas this year from
  the kernel test robot (a 244% r/w bandwidth improvement with XFS over
  DAX, with 4k writes):

    https://lkml.org/lkml/2017/12/25/8

  A few of the earlier patches in this pile are also flowing to you via
  other trees (mm, integrity, and nfsd trees in particular)".

* tag 'iversion-v4.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux: (22 commits)
  fs: handle inode->i_version more efficiently
  btrfs: only dirty the inode in btrfs_update_time if something was changed
  xfs: avoid setting XFS_ILOG_CORE if i_version doesn't need incrementing
  fs: only set S_VERSION when updating times if necessary
  IMA: switch IMA over to new i_version API
  xfs: convert to new i_version API
  ufs: use new i_version API
  ocfs2: convert to new i_version API
  nfsd: convert to new i_version API
  nfs: convert to new i_version API
  ext4: convert to new i_version API
  ext2: convert to new i_version API
  exofs: switch to new i_version API
  btrfs: convert to new i_version API
  afs: convert to new i_version API
  affs: convert to new i_version API
  fat: convert to new i_version API
  fs: don't take the i_lock in inode_inc_iversion
  fs: new API for handling inode->i_version
  ntfs: remove i_version handling
  ...
2018-01-29 13:33:53 -08:00
Jeff Layton
c7f88c4e78 btrfs: convert to new i_version API
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: David Sterba <dsterba@suse.com>
2018-01-29 06:42:20 -05:00
Josef Bacik
e4fd493c05 Btrfs: fix stale entries in readdir
In fixing the readdir+pagefault deadlock I accidentally introduced a
stale entry regression in readdir.  If we get close to full for the
temporary buffer, and then skip a few delayed deletions, and then try to
add another entry that won't fit, we will emit the entries we found and
retry.  Unfortunately we delete entries from our del_list as we find
them, assuming we won't need them.  However our pos will be with
whatever our last entry was, which could be before the delayed deletions
we skipped, so the next search will add the deleted entries back into
our readdir buffer.  So instead don't delete entries we find in our
del_list so we can make sure we always find our delayed deletions.  This
is a slight perf hit for readdir with lots of pending deletions, but
hopefully this isn't a common occurrence.  If it is we can revist this
and optimize it.

cc: stable@vger.kernel.org
Fixes: 23b5ec7494 ("btrfs: fix readdir deadlock with pagefault")
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-24 20:27:48 +01:00
Nikolay Borisov
8577787fac btrfs: Move checks from btrfs_wq_run_delayed_node to btrfs_balance_delayed_items
btrfs_balance_delayed_items is the sole caller of
btrfs_wq_run_delayed_node and already includes one of the checks whether
the delayed inodes should be run. On the other hand
btrfs_wq_run_delayed_node duplicates that check and performs an
additional one for wq congestion.

Let's remove the duplicate check and move the congestion one in
btrfs_balance_delayed_items, leaving btrfs_wq_run_delayed_node to only
care about setting up the wq run. No functional changes.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 16:08:11 +01:00
Nikolay Borisov
617c54a88e btrfs: Make btrfs_async_run_delayed_root use a loop rather than multiple labels
Currently btrfs_async_run_delayed_root's implementation uses 3 goto
labels to mimic the functionality of a simple do {} while loop. Refactor
the function to use a do {} while construct, making intention clear and
code easier to follow. No functional changes.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 16:08:11 +01:00
Chris Mason
ec35e48b28 btrfs: fix refcount_t usage when deleting btrfs_delayed_nodes
refcounts have a generic implementation and an asm optimized one.  The
generic version has extra debugging to make sure that once a refcount
goes to zero, refcount_inc won't increase it.

The btrfs delayed inode code wasn't expecting this, and we're tripping
over the warnings when the generic refcounts are used.  We ended up with
this race:

Process A                                         Process B
                                                  btrfs_get_delayed_node()
						  spin_lock(root->inode_lock)
						  radix_tree_lookup()
__btrfs_release_delayed_node()
refcount_dec_and_test(&delayed_node->refs)
our refcount is now zero
						  refcount_add(2) <---
						  warning here, refcount
                                                  unchanged

spin_lock(root->inode_lock)
radix_tree_delete()

With the generic refcounts, we actually warn again when process B above
tries to release his refcount because refcount_add() turned into a
no-op.

We saw this in production on older kernels without the asm optimized
refcounts.

The fix used here is to use refcount_inc_not_zero() to detect when the
object is in the middle of being freed and return NULL.  This is almost
always the right answer anyway, since we usually end up pitching the
delayed_node if it didn't have fresh data in it.

This also changes __btrfs_release_delayed_node() to remove the extra
check for zero refcounts before radix tree deletion.
btrfs_get_delayed_node() was the only path that was allowing refcounts
to go from zero to one.

Fixes: 6de5f18e7b ("btrfs: fix refcount_t usage when deleting btrfs_delayed_node")
CC: <stable@vger.kernel.org> # 4.12+
Signed-off-by: Chris Mason <clm@fb.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-02 18:00:14 +01:00
Josef Bacik
69fe2d75dd btrfs: make the delalloc block rsv per inode
The way we handle delalloc metadata reservations has gotten
progressively more complicated over the years.  There is so much cruft
and weirdness around keeping the reserved count and outstanding counters
consistent and handling the error cases that it's impossible to
understand.

Fix this by making the delalloc block rsv per-inode.  This way we can
calculate the actual size of the outstanding metadata reservations every
time we make a change, and then reserve the delta based on that amount.
This greatly simplifies the code everywhere, and makes the error
handling in btrfs_delalloc_reserve_metadata far less terrifying.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-01 20:45:35 +01:00
Josef Bacik
42e9cc46fb btrfs: increase ctx->pos for delayed dir index
Our dir_context->pos is supposed to hold the next position we're
supposed to look.  If we successfully insert a delayed dir index we
could end up with a duplicate entry because we don't increase ctx->pos
after doing the dir_emit.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-18 16:36:20 +02:00
Elena Reshetova
089e77e10d btrfs: convert btrfs_delayed_item.refs from atomic_t to refcount_t
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:23 +02:00
Elena Reshetova
6de5f18e7b btrfs: convert btrfs_delayed_node.refs from atomic_t to refcount_t
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:23 +02:00