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commit 58bfe2ccec5f9f137b41dd38f335290dcc13cd5c upstream.
A user reported some issues with smaller file systems that get very
full. While investigating this issue I noticed that df wasn't showing
100% full, despite having 0 chunk space and having < 1MiB of available
metadata space.
This turns out to be an overflow issue, we're doing:
total_available_metadata_space - SZ_4M < global_block_rsv_size
to determine if there's not enough space to make metadata allocations,
which overflows if total_available_metadata_space is < 4M. Fix this by
checking to see if our available space is greater than the 4M threshold.
This makes df properly report 100% usage on the file system.
CC: stable@vger.kernel.org # 4.14+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 91bfe3104b8db0310f76f2dcb6aacef24c889366 ]
If we fail to add a delayed dir index item because there's already another
item with the same index number, we print an error message (and then BUG).
However that message isn't very helpful to debug anything because we don't
know what's the index number and what are the values of index counters in
the inode and its delayed inode (index_cnt fields of struct btrfs_inode
and struct btrfs_delayed_node).
So update the error message to include the index number and counters.
We actually had a recent case where this issue was hit by a syzbot report
(see the link below).
Link: https://lore.kernel.org/linux-btrfs/00000000000036e1290603e097e0@google.com/
Reviewed-by: Qu Wenruo <wqu@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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 74ee79142c0a344d4eae2eb7012ebc4e82254109 ]
Commit f98b6215d7d1 ("btrfs: extent_io: do extra check for extent buffer
read write functions") changed how we handle invalid extent buffer range
for read_extent_buffer().
Previously if the range is invalid we just set the destination to zero,
but after the patch we do nothing and error out.
This can lead to smatch static checker errors like:
fs/btrfs/print-tree.c:186 print_uuid_item() error: uninitialized symbol 'subvol_id'.
fs/btrfs/tests/extent-io-tests.c:338 check_eb_bitmap() error: uninitialized symbol 'has'.
fs/btrfs/tests/extent-io-tests.c:353 check_eb_bitmap() error: uninitialized symbol 'has'.
fs/btrfs/uuid-tree.c:203 btrfs_uuid_tree_remove() error: uninitialized symbol 'read_subid'.
fs/btrfs/uuid-tree.c:353 btrfs_uuid_tree_iterate() error: uninitialized symbol 'subid_le'.
fs/btrfs/uuid-tree.c:72 btrfs_uuid_tree_lookup() error: uninitialized symbol 'data'.
fs/btrfs/volumes.c:7415 btrfs_dev_stats_value() error: uninitialized symbol 'val'.
Fix those warnings by reverting back to the old memset() behavior.
By this we keep the static checker happy and would still make a lot of
noise when such invalid ranges are passed in.
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Fixes: f98b6215d7d1 ("btrfs: extent_io: do extra check for extent buffer read write functions")
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit ee34a82e890a7babb5585daf1a6dd7d4d1cf142a upstream.
During the ino lookup ioctl we can end up calling btrfs_iget() to get an
inode reference while we are holding on a root's btree. If btrfs_iget()
needs to lookup the inode from the root's btree, because it's not
currently loaded in memory, then it will need to lock another or the
same path in the same root btree. This may result in a deadlock and
trigger the following lockdep splat:
WARNING: possible circular locking dependency detected
6.5.0-rc7-syzkaller-00004-gf7757129e3de #0 Not tainted
------------------------------------------------------
syz-executor277/5012 is trying to acquire lock:
ffff88802df41710 (btrfs-tree-01){++++}-{3:3}, at: __btrfs_tree_read_lock+0x2f/0x220 fs/btrfs/locking.c:136
but task is already holding lock:
ffff88802df418e8 (btrfs-tree-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x2f/0x220 fs/btrfs/locking.c:136
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (btrfs-tree-00){++++}-{3:3}:
down_read_nested+0x49/0x2f0 kernel/locking/rwsem.c:1645
__btrfs_tree_read_lock+0x2f/0x220 fs/btrfs/locking.c:136
btrfs_search_slot+0x13a4/0x2f80 fs/btrfs/ctree.c:2302
btrfs_init_root_free_objectid+0x148/0x320 fs/btrfs/disk-io.c:4955
btrfs_init_fs_root fs/btrfs/disk-io.c:1128 [inline]
btrfs_get_root_ref+0x5ae/0xae0 fs/btrfs/disk-io.c:1338
btrfs_get_fs_root fs/btrfs/disk-io.c:1390 [inline]
open_ctree+0x29c8/0x3030 fs/btrfs/disk-io.c:3494
btrfs_fill_super+0x1c7/0x2f0 fs/btrfs/super.c:1154
btrfs_mount_root+0x7e0/0x910 fs/btrfs/super.c:1519
legacy_get_tree+0xef/0x190 fs/fs_context.c:611
vfs_get_tree+0x8c/0x270 fs/super.c:1519
fc_mount fs/namespace.c:1112 [inline]
vfs_kern_mount+0xbc/0x150 fs/namespace.c:1142
btrfs_mount+0x39f/0xb50 fs/btrfs/super.c:1579
legacy_get_tree+0xef/0x190 fs/fs_context.c:611
vfs_get_tree+0x8c/0x270 fs/super.c:1519
do_new_mount+0x28f/0xae0 fs/namespace.c:3335
do_mount fs/namespace.c:3675 [inline]
__do_sys_mount fs/namespace.c:3884 [inline]
__se_sys_mount+0x2d9/0x3c0 fs/namespace.c:3861
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
-> #0 (btrfs-tree-01){++++}-{3:3}:
check_prev_add kernel/locking/lockdep.c:3142 [inline]
check_prevs_add kernel/locking/lockdep.c:3261 [inline]
validate_chain kernel/locking/lockdep.c:3876 [inline]
__lock_acquire+0x39ff/0x7f70 kernel/locking/lockdep.c:5144
lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5761
down_read_nested+0x49/0x2f0 kernel/locking/rwsem.c:1645
__btrfs_tree_read_lock+0x2f/0x220 fs/btrfs/locking.c:136
btrfs_tree_read_lock fs/btrfs/locking.c:142 [inline]
btrfs_read_lock_root_node+0x292/0x3c0 fs/btrfs/locking.c:281
btrfs_search_slot_get_root fs/btrfs/ctree.c:1832 [inline]
btrfs_search_slot+0x4ff/0x2f80 fs/btrfs/ctree.c:2154
btrfs_lookup_inode+0xdc/0x480 fs/btrfs/inode-item.c:412
btrfs_read_locked_inode fs/btrfs/inode.c:3892 [inline]
btrfs_iget_path+0x2d9/0x1520 fs/btrfs/inode.c:5716
btrfs_search_path_in_tree_user fs/btrfs/ioctl.c:1961 [inline]
btrfs_ioctl_ino_lookup_user+0x77a/0xf50 fs/btrfs/ioctl.c:2105
btrfs_ioctl+0xb0b/0xd40 fs/btrfs/ioctl.c:4683
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl+0xf8/0x170 fs/ioctl.c:856
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
rlock(btrfs-tree-00);
lock(btrfs-tree-01);
lock(btrfs-tree-00);
rlock(btrfs-tree-01);
*** DEADLOCK ***
1 lock held by syz-executor277/5012:
#0: ffff88802df418e8 (btrfs-tree-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x2f/0x220 fs/btrfs/locking.c:136
stack backtrace:
CPU: 1 PID: 5012 Comm: syz-executor277 Not tainted 6.5.0-rc7-syzkaller-00004-gf7757129e3de #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106
check_noncircular+0x375/0x4a0 kernel/locking/lockdep.c:2195
check_prev_add kernel/locking/lockdep.c:3142 [inline]
check_prevs_add kernel/locking/lockdep.c:3261 [inline]
validate_chain kernel/locking/lockdep.c:3876 [inline]
__lock_acquire+0x39ff/0x7f70 kernel/locking/lockdep.c:5144
lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5761
down_read_nested+0x49/0x2f0 kernel/locking/rwsem.c:1645
__btrfs_tree_read_lock+0x2f/0x220 fs/btrfs/locking.c:136
btrfs_tree_read_lock fs/btrfs/locking.c:142 [inline]
btrfs_read_lock_root_node+0x292/0x3c0 fs/btrfs/locking.c:281
btrfs_search_slot_get_root fs/btrfs/ctree.c:1832 [inline]
btrfs_search_slot+0x4ff/0x2f80 fs/btrfs/ctree.c:2154
btrfs_lookup_inode+0xdc/0x480 fs/btrfs/inode-item.c:412
btrfs_read_locked_inode fs/btrfs/inode.c:3892 [inline]
btrfs_iget_path+0x2d9/0x1520 fs/btrfs/inode.c:5716
btrfs_search_path_in_tree_user fs/btrfs/ioctl.c:1961 [inline]
btrfs_ioctl_ino_lookup_user+0x77a/0xf50 fs/btrfs/ioctl.c:2105
btrfs_ioctl+0xb0b/0xd40 fs/btrfs/ioctl.c:4683
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl+0xf8/0x170 fs/ioctl.c:856
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f0bec94ea39
Fix this simply by releasing the path before calling btrfs_iget() as at
point we don't need the path anymore.
Reported-by: syzbot+bf66ad948981797d2f1d@syzkaller.appspotmail.com
Link: https://lore.kernel.org/linux-btrfs/00000000000045fa140603c4a969@google.com/
Fixes: 23d0b79dfaed ("btrfs: Add unprivileged version of ino_lookup ioctl")
CC: stable@vger.kernel.org # 4.19+
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 6bfe3959b0e7a526f5c64747801a8613f002f05a ]
The function btrfs_validate_super() should verify the metadata_uuid in
the provided superblock argument. Because, all its callers expect it to
do that.
Such as in the following stacks:
write_all_supers()
sb = fs_info->super_for_commit;
btrfs_validate_write_super(.., sb)
btrfs_validate_super(.., sb, ..)
scrub_one_super()
btrfs_validate_super(.., sb, ..)
And
check_dev_super()
btrfs_validate_super(.., sb, ..)
However, it currently verifies the fs_info::super_copy::metadata_uuid
instead. Fix this using the correct metadata_uuid in the superblock
argument.
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Tested-by: Guilherme G. Piccoli <gpiccoli@igalia.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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 4844c3664a72d36cc79752cb651c78860b14c240 ]
In some cases, we need to read the FSID from the superblock when the
metadata_uuid is not set, and otherwise, read the metadata_uuid. So,
add a helper.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Tested-by: Guilherme G. Piccoli <gpiccoli@igalia.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>
Stable-dep-of: 6bfe3959b0e7 ("btrfs: compare the correct fsid/metadata_uuid in btrfs_validate_super")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit c2e79e865b87c2920a3cd39de69c35f2bc758a51 ]
This is defined in volumes.c, move the prototype into volumes.h.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Stable-dep-of: 6bfe3959b0e7 ("btrfs: compare the correct fsid/metadata_uuid in btrfs_validate_super")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 7f72f50547b7af4ddf985b07fc56600a4deba281 ]
[BUG]
Syzbot reported several warning triggered inside
lookup_inline_extent_backref().
[CAUSE]
As usual, the reproducer doesn't reliably trigger locally here, but at
least we know the WARN_ON() is triggered when an inline backref can not
be found, and it can only be triggered when @insert is true. (I.e.
inserting a new inline backref, which means the backref should already
exist)
[ENHANCEMENT]
After the WARN_ON(), dump all the parameters and the extent tree
leaf to help debug.
Link: https://syzkaller.appspot.com/bug?extid=d6f9ff86c1d804ba2bc6
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit d167aa76dc0683828588c25767da07fb549e4f48 upstream.
The function btrfs_validate_super() should verify the fsid in the provided
superblock argument. Because, all its callers expect it to do that.
Such as in the following stack:
write_all_supers()
sb = fs_info->super_for_commit;
btrfs_validate_write_super(.., sb)
btrfs_validate_super(.., sb, ..)
scrub_one_super()
btrfs_validate_super(.., sb, ..)
And
check_dev_super()
btrfs_validate_super(.., sb, ..)
However, it currently verifies the fs_info::super_copy::fsid instead,
which is not correct. Fix this using the correct fsid in the superblock
argument.
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Tested-by: Guilherme G. Piccoli <gpiccoli@igalia.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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4490e803e1fe9fab8db5025e44e23b55df54078b upstream.
When joining a transaction with TRANS_JOIN_NOSTART, if we don't find a
running transaction we end up creating one. This goes against the purpose
of TRANS_JOIN_NOSTART which is to join a running transaction if its state
is at or below the state TRANS_STATE_COMMIT_START, otherwise return an
-ENOENT error and don't start a new transaction. So fix this to not create
a new transaction if there's no running transaction at or below that
state.
CC: stable@vger.kernel.org # 4.14+
Fixes: a6d155d2e363 ("Btrfs: fix deadlock between fiemap and transaction commits")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e28b02118b94e42be3355458a2406c6861e2dd32 upstream.
If we do a write whose bio suffers an error, we will never reclaim the
qgroup reserved space for it. We allocate the space in the write_iter
codepath, then release the reservation as we allocate the ordered
extent, but we only create a delayed ref if the ordered extent finishes.
If it has an error, we simply leak the rsv. This is apparent in running
any error injecting (dmerror) fstests like btrfs/146 or btrfs/160. Such
tests fail due to dmesg on umount complaining about the leaked qgroup
data space.
When we clean up other aspects of space on failed ordered_extents, also
free the qgroup rsv.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
CC: stable@vger.kernel.org # 5.10+
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 29eefa6d0d07e185f7bfe9576f91e6dba98189c2 upstream.
Pausing and canceling balance can race to interrupt balance lead to BUG_ON
panic in btrfs_cancel_balance. The BUG_ON condition in btrfs_cancel_balance
does not take this race scenario into account.
However, the race condition has no other side effects. We can fix that.
Reproducing it with panic trace like this:
kernel BUG at fs/btrfs/volumes.c:4618!
RIP: 0010:btrfs_cancel_balance+0x5cf/0x6a0
Call Trace:
<TASK>
? do_nanosleep+0x60/0x120
? hrtimer_nanosleep+0xb7/0x1a0
? sched_core_clone_cookie+0x70/0x70
btrfs_ioctl_balance_ctl+0x55/0x70
btrfs_ioctl+0xa46/0xd20
__x64_sys_ioctl+0x7d/0xa0
do_syscall_64+0x38/0x80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Race scenario as follows:
> mutex_unlock(&fs_info->balance_mutex);
> --------------------
> .......issue pause and cancel req in another thread
> --------------------
> ret = __btrfs_balance(fs_info);
>
> mutex_lock(&fs_info->balance_mutex);
> if (ret == -ECANCELED && atomic_read(&fs_info->balance_pause_req)) {
> btrfs_info(fs_info, "balance: paused");
> btrfs_exclop_balance(fs_info, BTRFS_EXCLOP_BALANCE_PAUSED);
> }
CC: stable@vger.kernel.org # 4.19+
Signed-off-by: xiaoshoukui <xiaoshoukui@ruijie.com.cn>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit a9f189716cf15913c453299d72f69c51a9b0f86b ]
An unused block group is easy to remove to free up space and should be
reclaimed fast. Such block group can often already be a target of the
reclaim process. As we check list_empty(&bg->bg_list), we keep it in the
reclaim list. That block group is never reclaimed until the file system
is filled e.g. up to 75%.
Instead, we can move unused block group to the unused list and delete it
fast.
Fixes: 18bb8bbf13c1 ("btrfs: zoned: automatically reclaim zones")
CC: stable@vger.kernel.org # 5.15+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 92fb94b69c6accf1e49fff699640fa0ce03dc910 upstream.
We set cache_block_group_error if btrfs_cache_block_group() returns an
error, this is because we could end up not finding space to allocate and
mistakenly return -ENOSPC, and which could then abort the transaction
with the incorrect errno, and in the case of ENOSPC result in a
WARN_ON() that will trip up tests like generic/475.
However there's the case where multiple threads can be racing, one
thread gets the proper error, and the other thread doesn't actually call
btrfs_cache_block_group(), it instead sees ->cached ==
BTRFS_CACHE_ERROR. Again the result is the same, we fail to allocate
our space and return -ENOSPC. Instead we need to set
cache_block_group_error to -EIO in this case to make sure that if we do
not make our allocation we get the appropriate error returned back to
the caller.
CC: stable@vger.kernel.org # 4.14+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6ebcd021c92b8e4b904552e4d87283032100796d upstream.
[BUG]
Syzbot reported a crash that an ASSERT() got triggered inside
prepare_to_merge().
That ASSERT() makes sure the reloc tree is properly pointed back by its
subvolume tree.
[CAUSE]
After more debugging output, it turns out we had an invalid reloc tree:
BTRFS error (device loop1): reloc tree mismatch, root 8 has no reloc root, expect reloc root key (-8, 132, 8) gen 17
Note the above root key is (TREE_RELOC_OBJECTID, ROOT_ITEM,
QUOTA_TREE_OBJECTID), meaning it's a reloc tree for quota tree.
But reloc trees can only exist for subvolumes, as for non-subvolume
trees, we just COW the involved tree block, no need to create a reloc
tree since those tree blocks won't be shared with other trees.
Only subvolumes tree can share tree blocks with other trees (thus they
have BTRFS_ROOT_SHAREABLE flag).
Thus this new debug output proves my previous assumption that corrupted
on-disk data can trigger that ASSERT().
[FIX]
Besides the dedicated fix and the graceful exit, also let tree-checker to
check such root keys, to make sure reloc trees can only exist for subvolumes.
CC: stable@vger.kernel.org # 5.15+
Reported-by: syzbot+ae97a827ae1c3336bbb4@syzkaller.appspotmail.com
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 05d7ce504545f7874529701664c90814ca645c5d upstream.
[BUG]
Syzbot reported a crash that an ASSERT() got triggered inside
prepare_to_merge().
[CAUSE]
The root cause of the triggered ASSERT() is we can have a race between
quota tree creation and relocation.
This leads us to create a duplicated quota tree in the
btrfs_read_fs_root() path, and since it's treated as fs tree, it would
have ROOT_SHAREABLE flag, causing us to create a reloc tree for it.
The bug itself is fixed by a dedicated patch for it, but this already
taught us the ASSERT() is not something straightforward for
developers.
[ENHANCEMENT]
Instead of using an ASSERT(), let's handle it gracefully and output
extra info about the mismatch reloc roots to help debug.
Also with the above ASSERT() removed, we can trigger ASSERT(0)s inside
merge_reloc_roots() later.
Also replace those ASSERT(0)s with WARN_ON()s.
CC: stable@vger.kernel.org # 5.15+
Reported-by: syzbot+ae97a827ae1c3336bbb4@syzkaller.appspotmail.com
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit effa24f689ce0948f68c754991a445a8d697d3a8 upstream.
extent_write_cache_pages stops writing pages as soon as nr_to_write hits
zero. That is the right thing for opportunistic writeback, but incorrect
for data integrity writeback, which needs to ensure that no dirty pages
are left in the range. Thus only stop the writeback for WB_SYNC_NONE
if nr_to_write hits 0.
This is a port of write_cache_pages changes in commit 05fe478dd04e
("mm: write_cache_pages integrity fix").
Note that I've only trigger the problem with other changes to the btrfs
writeback code, but this condition seems worthwhile fixing anyway.
CC: stable@vger.kernel.org # 4.14+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
[ updated comment ]
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b28ff3a7d7e97456fd86b68d24caa32e1cfa7064 upstream.
btrfs_attach_transaction_barrier() is used to get a handle pointing to the
current running transaction if the transaction has not started its commit
yet (its state is < TRANS_STATE_COMMIT_START). If the transaction commit
has started, then we wait for the transaction to commit and finish before
returning - however we completely ignore if the transaction was aborted
due to some error during its commit, we simply return ERR_PT(-ENOENT),
which makes the caller assume everything is fine and no errors happened.
This could make an fsync return success (0) to user space when in fact we
had a transaction abort and the target inode changes were therefore not
persisted.
Fix this by checking for the return value from btrfs_wait_for_commit(),
and if it returned an error, return it back to the caller.
Fixes: d4edf39bd5db ("Btrfs: fix uncompleted transaction")
CC: stable@vger.kernel.org # 4.19+
Reviewed-by: Qu Wenruo <wqu@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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit bf7ecbe9875061bf3fce1883e3b26b77f847d1e8 upstream.
At btrfs_wait_for_commit() we wait for a transaction to finish and then
always return 0 (success) without checking if it was aborted, in which
case the transaction didn't happen due to some critical error. Fix this
by checking if the transaction was aborted.
Fixes: 462045928bda ("Btrfs: add START_SYNC, WAIT_SYNC ioctls")
CC: stable@vger.kernel.org # 4.19+
Reviewed-by: Qu Wenruo <wqu@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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 8a4a0b2a3eaf75ca8854f856ef29690c12b2f531 ]
If we disable quotas while we have a relocation of a metadata block group
that has extents belonging to the quota root, we can cause the relocation
to fail with -ENOENT. This is because relocation builds backref nodes for
extents of the quota root and later needs to walk the backrefs and access
the quota root - however if in between a task disables quotas, it results
in deleting the quota root from the root tree (with btrfs_del_root(),
called from btrfs_quota_disable().
This can be sporadically triggered by test case btrfs/255 from fstests:
$ ./check btrfs/255
FSTYP -- btrfs
PLATFORM -- Linux/x86_64 debian0 6.4.0-rc6-btrfs-next-134+ #1 SMP PREEMPT_DYNAMIC Thu Jun 15 11:59:28 WEST 2023
MKFS_OPTIONS -- /dev/sdc
MOUNT_OPTIONS -- /dev/sdc /home/fdmanana/btrfs-tests/scratch_1
btrfs/255 6s ... _check_dmesg: something found in dmesg (see /home/fdmanana/git/hub/xfstests/results//btrfs/255.dmesg)
- output mismatch (see /home/fdmanana/git/hub/xfstests/results//btrfs/255.out.bad)
# --- tests/btrfs/255.out 2023-03-02 21:47:53.876609426 +0000
# +++ /home/fdmanana/git/hub/xfstests/results//btrfs/255.out.bad 2023-06-16 10:20:39.267563212 +0100
# @@ -1,2 +1,4 @@
# QA output created by 255
# +ERROR: error during balancing '/home/fdmanana/btrfs-tests/scratch_1': No such file or directory
# +There may be more info in syslog - try dmesg | tail
# Silence is golden
# ...
(Run 'diff -u /home/fdmanana/git/hub/xfstests/tests/btrfs/255.out /home/fdmanana/git/hub/xfstests/results//btrfs/255.out.bad' to see the entire diff)
Ran: btrfs/255
Failures: btrfs/255
Failed 1 of 1 tests
To fix this make the quota disable operation take the cleaner mutex, as
relocation of a block group also takes this mutex. This is also what we
do when deleting a subvolume/snapshot, we take the cleaner mutex in the
cleaner kthread (at cleaner_kthread()) and then we call btrfs_del_root()
at btrfs_drop_snapshot() while under the protection of the cleaner mutex.
Fixes: bed92eae26cc ("Btrfs: qgroup implementation and prototypes")
CC: stable@vger.kernel.org # 5.4+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit f1a07c2b4e2c473ec322b8b9ece071b8c88a3512 upstream.
At exclude_super_stripes(), if we happen to find a block group that has
super blocks mapped to it and we are on a zoned filesystem, we error out
as this is not supposed to happen, indicating either a bug or maybe some
memory corruption for example. However we are exiting the function without
freeing the memory allocated for the logical address of the super blocks.
Fix this by freeing the logical address.
Fixes: 12659251ca5d ("btrfs: implement log-structured superblock for ZONED mode")
CC: stable@vger.kernel.org # 5.10+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 40b0a749388517de244643c09bdbb98f7dcb6ef1 upstream.
At __btrfs_cow_block(), instead of doing a BUG_ON() in case we fail to
record a tree mod log root insertion operation, do a transaction abort
instead. There's really no need for the BUG_ON(), we can properly
release all resources in this context and turn the filesystem to RO mode
and in an error state instead.
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Qu Wenruo <wqu@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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ede600e497b1461d06d22a7d17703d9096868bc3 upstream.
At split_node(), if we fail to log the tree mod log copy operation, we
return without unlocking the split extent buffer we just allocated and
without decrementing the reference we own on it. Fix this by unlocking
it and decrementing the ref count before returning.
Fixes: 5de865eebb83 ("Btrfs: fix tree mod logging")
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Qu Wenruo <wqu@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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7e27180994383b7c741ad87749db01e4989a02ba upstream.
The reclaim process can temporarily fail. For example, if the space is
getting tight, it fails to make the block group read-only. If there are no
further writes on that block group, the block group will never get back to
the reclaim list, and the BG never gets reclaimed. In a certain workload,
we can leave many such block groups never reclaimed.
So, let's get it back to the list and give it a chance to be reclaimed.
Fixes: 18bb8bbf13c1 ("btrfs: zoned: automatically reclaim zones")
CC: stable@vger.kernel.org # 5.15+
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 93463ff7b54626f8276c0bd3d3f968fbf8d5d380 upstream.
When a filesystem is read-only, we cannot reclaim a block group as it
cannot rewrite the data. Just bail out in that case.
Note that it can drop block groups in this case. As we did
sb_start_write(), read-only filesystem means we got a fatal error and
forced read-only. There is no chance to reclaim them again.
Fixes: 18bb8bbf13c1 ("btrfs: zoned: automatically reclaim zones")
CC: stable@vger.kernel.org # 5.15+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3ed01616bad6c7e3de196676b542ae3df8058592 upstream.
The reclaiming process only starts after the filesystem volumes are
allocated to a certain level (75% by default). Thus, the list of
reclaiming target block groups can build up so huge at the time the
reclaim process kicks in. On a test run, there were over 1000 BGs in the
reclaim list.
As the reclaim involves rewriting the data, it takes really long time to
reclaim the BGs. While the reclaim is running, btrfs_delete_unused_bgs()
won't proceed because the reclaim side is holding
fs_info->reclaim_bgs_lock. As a result, we will have a large number of
unused BGs kept in the unused list. On my test run, I got 1057 unused BGs.
Since deleting a block group is relatively easy and fast work, we can call
btrfs_delete_unused_bgs() while it reclaims BGs, to avoid building up
unused BGs.
Fixes: 18bb8bbf13c1 ("btrfs: zoned: automatically reclaim zones")
CC: stable@vger.kernel.org # 5.15+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 160fe8f6fdb13da6111677be6263e5d65e875987 upstream.
Callers of `btrfs_reduce_alloc_profile` expect it to return exactly
one allocation profile flag, and failing to do so may ultimately
result in a WARN_ON and remount-ro when allocating new blocks, like
the below transaction abort on 6.1.
`btrfs_reduce_alloc_profile` has two ways of determining the profile,
first it checks if a conversion balance is currently running and
uses the profile we're converting to. If no balance is currently
running, it returns the max-redundancy profile which at least one
block in the selected block group has.
This works by simply checking each known allocation profile bit in
redundancy order. However, `btrfs_reduce_alloc_profile` has not been
updated as new flags have been added - first with the `DUP` profile
and later with the RAID1C34 profiles.
Because of the way it checks, if we have blocks with different
profiles and at least one is known, that profile will be selected.
However, if none are known we may return a flag set with multiple
allocation profiles set.
This is currently only possible when a balance from one of the three
unhandled profiles to another of the unhandled profiles is canceled
after allocating at least one block using the new profile.
In that case, a transaction abort like the below will occur and the
filesystem will need to be mounted with -o skip_balance to get it
mounted rw again (but the balance cannot be resumed without a
similar abort).
[770.648] ------------[ cut here ]------------
[770.648] BTRFS: Transaction aborted (error -22)
[770.648] WARNING: CPU: 43 PID: 1159593 at fs/btrfs/extent-tree.c:4122 find_free_extent+0x1d94/0x1e00 [btrfs]
[770.648] CPU: 43 PID: 1159593 Comm: btrfs Tainted: G W 6.1.0-0.deb11.7-powerpc64le #1 Debian 6.1.20-2~bpo11+1a~test
[770.648] Hardware name: T2P9D01 REV 1.00 POWER9 0x4e1202 opal:skiboot-bc106a0 PowerNV
[770.648] NIP: c00800000f6784fc LR: c00800000f6784f8 CTR: c000000000d746c0
[770.648] REGS: c000200089afe9a0 TRAP: 0700 Tainted: G W (6.1.0-0.deb11.7-powerpc64le Debian 6.1.20-2~bpo11+1a~test)
[770.648] MSR: 9000000002029033 <SF,HV,VEC,EE,ME,IR,DR,RI,LE> CR: 28848282 XER: 20040000
[770.648] CFAR: c000000000135110 IRQMASK: 0
GPR00: c00800000f6784f8 c000200089afec40 c00800000f7ea800 0000000000000026
GPR04: 00000001004820c2 c000200089afea00 c000200089afe9f8 0000000000000027
GPR08: c000200ffbfe7f98 c000000002127f90 ffffffffffffffd8 0000000026d6a6e8
GPR12: 0000000028848282 c000200fff7f3800 5deadbeef0000122 c00000002269d000
GPR16: c0002008c7797c40 c000200089afef17 0000000000000000 0000000000000000
GPR20: 0000000000000000 0000000000000001 c000200008bc5a98 0000000000000001
GPR24: 0000000000000000 c0000003c73088d0 c000200089afef17 c000000016d3a800
GPR28: c0000003c7308800 c00000002269d000 ffffffffffffffea 0000000000000001
[770.648] NIP [c00800000f6784fc] find_free_extent+0x1d94/0x1e00 [btrfs]
[770.648] LR [c00800000f6784f8] find_free_extent+0x1d90/0x1e00 [btrfs]
[770.648] Call Trace:
[770.648] [c000200089afec40] [c00800000f6784f8] find_free_extent+0x1d90/0x1e00 [btrfs] (unreliable)
[770.648] [c000200089afed30] [c00800000f681398] btrfs_reserve_extent+0x1a0/0x2f0 [btrfs]
[770.648] [c000200089afeea0] [c00800000f681bf0] btrfs_alloc_tree_block+0x108/0x670 [btrfs]
[770.648] [c000200089afeff0] [c00800000f66bd68] __btrfs_cow_block+0x170/0x850 [btrfs]
[770.648] [c000200089aff100] [c00800000f66c58c] btrfs_cow_block+0x144/0x288 [btrfs]
[770.648] [c000200089aff1b0] [c00800000f67113c] btrfs_search_slot+0x6b4/0xcb0 [btrfs]
[770.648] [c000200089aff2a0] [c00800000f679f60] lookup_inline_extent_backref+0x128/0x7c0 [btrfs]
[770.648] [c000200089aff3b0] [c00800000f67b338] lookup_extent_backref+0x70/0x190 [btrfs]
[770.648] [c000200089aff470] [c00800000f67b54c] __btrfs_free_extent+0xf4/0x1490 [btrfs]
[770.648] [c000200089aff5a0] [c00800000f67d770] __btrfs_run_delayed_refs+0x328/0x1530 [btrfs]
[770.648] [c000200089aff740] [c00800000f67ea2c] btrfs_run_delayed_refs+0xb4/0x3e0 [btrfs]
[770.648] [c000200089aff800] [c00800000f699aa4] btrfs_commit_transaction+0x8c/0x12b0 [btrfs]
[770.648] [c000200089aff8f0] [c00800000f6dc628] reset_balance_state+0x1c0/0x290 [btrfs]
[770.648] [c000200089aff9a0] [c00800000f6e2f7c] btrfs_balance+0x1164/0x1500 [btrfs]
[770.648] [c000200089affb40] [c00800000f6f8e4c] btrfs_ioctl+0x2b54/0x3100 [btrfs]
[770.648] [c000200089affc80] [c00000000053be14] sys_ioctl+0x794/0x1310
[770.648] [c000200089affd70] [c00000000002af98] system_call_exception+0x138/0x250
[770.648] [c000200089affe10] [c00000000000c654] system_call_common+0xf4/0x258
[770.648] --- interrupt: c00 at 0x7fff94126800
[770.648] NIP: 00007fff94126800 LR: 0000000107e0b594 CTR: 0000000000000000
[770.648] REGS: c000200089affe80 TRAP: 0c00 Tainted: G W (6.1.0-0.deb11.7-powerpc64le Debian 6.1.20-2~bpo11+1a~test)
[770.648] MSR: 900000000000d033 <SF,HV,EE,PR,ME,IR,DR,RI,LE> CR: 24002848 XER: 00000000
[770.648] IRQMASK: 0
GPR00: 0000000000000036 00007fffc9439da0 00007fff94217100 0000000000000003
GPR04: 00000000c4009420 00007fffc9439ee8 0000000000000000 0000000000000000
GPR08: 00000000803c7416 0000000000000000 0000000000000000 0000000000000000
GPR12: 0000000000000000 00007fff9467d120 0000000107e64c9c 0000000107e64d0a
GPR16: 0000000107e64d06 0000000107e64cf1 0000000107e64cc4 0000000107e64c73
GPR20: 0000000107e64c31 0000000107e64bf1 0000000107e64be7 0000000000000000
GPR24: 0000000000000000 00007fffc9439ee0 0000000000000003 0000000000000001
GPR28: 00007fffc943f713 0000000000000000 00007fffc9439ee8 0000000000000000
[770.648] NIP [00007fff94126800] 0x7fff94126800
[770.648] LR [0000000107e0b594] 0x107e0b594
[770.648] --- interrupt: c00
[770.648] Instruction dump:
[770.648] 3b00ffe4 e8898828 481175f5 60000000 4bfff4fc 3be00000 4bfff570 3d220000
[770.648] 7fc4f378 e8698830 4811cd95 e8410018 <0fe00000> f9c10060 f9e10068 fa010070
[770.648] ---[ end trace 0000000000000000 ]---
[770.648] BTRFS: error (device dm-2: state A) in find_free_extent_update_loop:4122: errno=-22 unknown
[770.648] BTRFS info (device dm-2: state EA): forced readonly
[770.648] BTRFS: error (device dm-2: state EA) in __btrfs_free_extent:3070: errno=-22 unknown
[770.648] BTRFS error (device dm-2: state EA): failed to run delayed ref for logical 17838685708288 num_bytes 24576 type 184 action 2 ref_mod 1: -22
[770.648] BTRFS: error (device dm-2: state EA) in btrfs_run_delayed_refs:2144: errno=-22 unknown
[770.648] BTRFS: error (device dm-2: state EA) in reset_balance_state:3599: errno=-22 unknown
Fixes: 47e6f7423b91 ("btrfs: add support for 3-copy replication (raid1c3)")
Fixes: 8d6fac0087e5 ("btrfs: add support for 4-copy replication (raid1c4)")
CC: stable@vger.kernel.org # 5.10+
Signed-off-by: Matt Corallo <blnxfsl@bluematt.me>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 39020d8abc7ec62c4de9b260e3d10d4a1c2478ce ]
At balance_level(), instead of doing a BUG_ON() in case we fail to record
tree mod log operations, do a transaction abort and return the error to
the callers. There's really no need for the BUG_ON() as we can release
all resources in this context, and we have to abort because other future
tree searches that use the tree mod log (btrfs_search_old_slot()) may get
inconsistent results if other operations modify the tree after that
failure and before the tree mod log based search.
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Qu Wenruo <wqu@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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 806570c0bb7b4847828c22c4934fcf2dc8fc572f ]
Since f8a53bb58ec7 ("btrfs: handle checksum generation in the storage
layer") the failures of btrfs_csum_one_bio() are handled via
bio_end_io().
This means, we can return BLK_STS_RESOURCE from btrfs_csum_one_bio() in
case the allocation of the ordered sums fails.
This also fixes a syzkaller report, where injecting a failure into the
kvzalloc() call results in a BUG_ON().
Reported-by: syzbot+d8941552e21eac774778@syzkaller.appspotmail.com
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 7561551e7ba870b9659083b95feb520fb2dacce3 ]
Currently we allow a block group not to be marked read-only for scrub.
But for RAID56 block groups if we require the block group to be
read-only, then we're allowed to use cached content from scrub stripe to
reduce unnecessary RAID56 reads.
So this patch would:
- Make btrfs_inc_block_group_ro() try harder
During my tests, for cases like btrfs/061 and btrfs/064, we can hit
ENOSPC from btrfs_inc_block_group_ro() calls during scrub.
The reason is if we only have one single data chunk, and trying to
scrub it, we won't have any space left for any newer data writes.
But this check should be done by the caller, especially for scrub
cases we only temporarily mark the chunk read-only.
And newer data writes would always try to allocate a new data chunk
when needed.
- Return error for scrub if we failed to mark a RAID56 chunk read-only
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 5ad9b4719fc9bc4715c7e19875a962095b0577e7 upstream.
When compiling on a MIPS 64-bit machine we get these warnings:
In file included from ./arch/mips/include/asm/cacheflush.h:13,
from ./include/linux/cacheflush.h:5,
from ./include/linux/highmem.h:8,
from ./include/linux/bvec.h:10,
from ./include/linux/blk_types.h:10,
from ./include/linux/blkdev.h:9,
from fs/btrfs/disk-io.c:7:
fs/btrfs/disk-io.c: In function ‘csum_tree_block’:
fs/btrfs/disk-io.c💯34: error: array subscript 1 is above array bounds of ‘struct page *[1]’ [-Werror=array-bounds]
100 | kaddr = page_address(buf->pages[i]);
| ~~~~~~~~~~^~~
./include/linux/mm.h:2135:48: note: in definition of macro ‘page_address’
2135 | #define page_address(page) lowmem_page_address(page)
| ^~~~
cc1: all warnings being treated as errors
We can check if i overflows to solve the problem. However, this doesn't make
much sense, since i == 1 and num_pages == 1 doesn't execute the body of the loop.
In addition, i < num_pages can also ensure that buf->pages[i] will not cross
the boundary. Unfortunately, this doesn't help with the problem observed here:
gcc still complains.
To fix this add a compile-time condition for the extent buffer page
array size limit, which would eventually lead to eliminating the whole
for loop.
CC: stable@vger.kernel.org # 5.10+
Signed-off-by: pengfuyuan <pengfuyuan@kylinos.cn>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 9ae5afd02a03d4e22a17a9609b19400b77c36273 ]
If the sibling keys check fails before we move keys from one sibling
leaf to another, we are not aborting the transaction - we leave that to
some higher level caller of btrfs_search_slot() (or anything else that
uses it to insert items into a b+tree).
This means that the transaction abort will provide a stack trace that
omits the b+tree modification call chain. So change this to immediately
abort the transaction and therefore get a more useful stack trace that
shows us the call chain in the bt+tree modification code.
It's also important to immediately abort the transaction just in case
some higher level caller is not doing it, as this indicates a very
serious corruption and we should stop the possibility of doing further
damage.
Reviewed-by: Qu Wenruo <wqu@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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 597441b3436a43011f31ce71dc0a6c0bf5ce958a upstream.
Our CI system caught a lockdep splat:
======================================================
WARNING: possible circular locking dependency detected
6.3.0-rc7+ #1167 Not tainted
------------------------------------------------------
kswapd0/46 is trying to acquire lock:
ffff8c6543abd650 (sb_internal#2){++++}-{0:0}, at: btrfs_commit_inode_delayed_inode+0x5f/0x120
but task is already holding lock:
ffffffffabe61b40 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x4aa/0x7a0
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (fs_reclaim){+.+.}-{0:0}:
fs_reclaim_acquire+0xa5/0xe0
kmem_cache_alloc+0x31/0x2c0
alloc_extent_state+0x1d/0xd0
__clear_extent_bit+0x2e0/0x4f0
try_release_extent_mapping+0x216/0x280
btrfs_release_folio+0x2e/0x90
invalidate_inode_pages2_range+0x397/0x470
btrfs_cleanup_dirty_bgs+0x9e/0x210
btrfs_cleanup_one_transaction+0x22/0x760
btrfs_commit_transaction+0x3b7/0x13a0
create_subvol+0x59b/0x970
btrfs_mksubvol+0x435/0x4f0
__btrfs_ioctl_snap_create+0x11e/0x1b0
btrfs_ioctl_snap_create_v2+0xbf/0x140
btrfs_ioctl+0xa45/0x28f0
__x64_sys_ioctl+0x88/0xc0
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x72/0xdc
-> #0 (sb_internal#2){++++}-{0:0}:
__lock_acquire+0x1435/0x21a0
lock_acquire+0xc2/0x2b0
start_transaction+0x401/0x730
btrfs_commit_inode_delayed_inode+0x5f/0x120
btrfs_evict_inode+0x292/0x3d0
evict+0xcc/0x1d0
inode_lru_isolate+0x14d/0x1e0
__list_lru_walk_one+0xbe/0x1c0
list_lru_walk_one+0x58/0x80
prune_icache_sb+0x39/0x60
super_cache_scan+0x161/0x1f0
do_shrink_slab+0x163/0x340
shrink_slab+0x1d3/0x290
shrink_node+0x300/0x720
balance_pgdat+0x35c/0x7a0
kswapd+0x205/0x410
kthread+0xf0/0x120
ret_from_fork+0x29/0x50
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(fs_reclaim);
lock(sb_internal#2);
lock(fs_reclaim);
lock(sb_internal#2);
*** DEADLOCK ***
3 locks held by kswapd0/46:
#0: ffffffffabe61b40 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x4aa/0x7a0
#1: ffffffffabe50270 (shrinker_rwsem){++++}-{3:3}, at: shrink_slab+0x113/0x290
#2: ffff8c6543abd0e0 (&type->s_umount_key#44){++++}-{3:3}, at: super_cache_scan+0x38/0x1f0
stack backtrace:
CPU: 0 PID: 46 Comm: kswapd0 Not tainted 6.3.0-rc7+ #1167
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x58/0x90
check_noncircular+0xd6/0x100
? save_trace+0x3f/0x310
? add_lock_to_list+0x97/0x120
__lock_acquire+0x1435/0x21a0
lock_acquire+0xc2/0x2b0
? btrfs_commit_inode_delayed_inode+0x5f/0x120
start_transaction+0x401/0x730
? btrfs_commit_inode_delayed_inode+0x5f/0x120
btrfs_commit_inode_delayed_inode+0x5f/0x120
btrfs_evict_inode+0x292/0x3d0
? lock_release+0x134/0x270
? __pfx_wake_bit_function+0x10/0x10
evict+0xcc/0x1d0
inode_lru_isolate+0x14d/0x1e0
__list_lru_walk_one+0xbe/0x1c0
? __pfx_inode_lru_isolate+0x10/0x10
? __pfx_inode_lru_isolate+0x10/0x10
list_lru_walk_one+0x58/0x80
prune_icache_sb+0x39/0x60
super_cache_scan+0x161/0x1f0
do_shrink_slab+0x163/0x340
shrink_slab+0x1d3/0x290
shrink_node+0x300/0x720
balance_pgdat+0x35c/0x7a0
kswapd+0x205/0x410
? __pfx_autoremove_wake_function+0x10/0x10
? __pfx_kswapd+0x10/0x10
kthread+0xf0/0x120
? __pfx_kthread+0x10/0x10
ret_from_fork+0x29/0x50
</TASK>
This happens because when we abort the transaction in the transaction
commit path we call invalidate_inode_pages2_range on our block group
cache inodes (if we have space cache v1) and any delalloc inodes we may
have. The plain invalidate_inode_pages2_range() call passes through
GFP_KERNEL, which makes sense in most cases, but not here. Wrap these
two invalidate callees with memalloc_nofs_save/memalloc_nofs_restore to
make sure we don't end up with the fs reclaim dependency under the
transaction dependency.
CC: stable@vger.kernel.org # 4.14+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0004ff15ea26015a0a3a6182dca3b9d1df32e2b7 upstream.
When loading a free space cache from disk, at __load_free_space_cache(),
if we fail to insert a bitmap entry, we still increment the number of
total bitmaps in the btrfs_free_space_ctl structure, which is incorrect
since we failed to add the bitmap entry. On error we then empty the
cache by calling __btrfs_remove_free_space_cache(), which will result
in getting the total bitmaps counter set to 1.
A failure to load a free space cache is not critical, so if a failure
happens we just rebuild the cache by scanning the extent tree, which
happens at block-group.c:caching_thread(). Yet the failure will result
in having the total bitmaps of the btrfs_free_space_ctl always bigger
by 1 then the number of bitmap entries we have. So fix this by having
the total bitmaps counter be incremented only if we successfully added
the bitmap entry.
Fixes: a67509c30079 ("Btrfs: add a io_ctl struct and helpers for dealing with the space cache")
Reviewed-by: Anand Jain <anand.jain@oracle.com>
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c87f318e6f47696b4040b58f460d5c17ea0280e6 upstream.
Check nodesize to sectorsize in alignment check in print_extent_item.
The comment states that and this is correct, similar check is done
elsewhere in the functions.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Fixes: ea57788eb76d ("btrfs: require only sector size alignment for parent eb bytenr")
CC: stable@vger.kernel.org # 4.14+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Anastasia Belova <abelova@astralinux.ru>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c83b56d1dd87cf67492bb770c26d6f87aee70ed6 upstream.
btrfs_redirty_list_add zeroes the buffer data and sets the
EXTENT_BUFFER_NO_CHECK to make sure writeback is fine with a bogus
header. But it does that after already marking the buffer dirty, which
means that writeback could already be looking at the buffer.
Switch the order of operations around so that the buffer is only marked
dirty when we're ready to write it.
Fixes: d3575156f662 ("btrfs: zoned: redirty released extent buffers")
CC: stable@vger.kernel.org # 5.15+
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d246331b78cbef86237f9c22389205bc9b4e1cc1 upstream.
Boris noticed in his simple quotas testing that he was getting a leak
with Sweet Tea's change to subvol create that stopped doing a
transaction commit. This was just a side effect of that change.
In the delayed inode code we have an optimization that will free extra
reservations if we think we can pack a dir item into an already modified
leaf. Previously this wouldn't be triggered in the subvolume create
case because we'd commit the transaction, it was still possible but
much harder to trigger. It could actually be triggered if we did a
mkdir && subvol create with qgroups enabled.
This occurs because in btrfs_insert_delayed_dir_index(), which gets
called when we're adding the dir item, we do the following:
btrfs_block_rsv_release(fs_info, trans->block_rsv, bytes, NULL);
if we're able to skip reserving space.
The problem here is that trans->block_rsv points at the temporary block
rsv for the subvolume create, which has qgroup reservations in the block
rsv.
This is a problem because btrfs_block_rsv_release() will do the
following:
if (block_rsv->qgroup_rsv_reserved >= block_rsv->qgroup_rsv_size) {
qgroup_to_release = block_rsv->qgroup_rsv_reserved -
block_rsv->qgroup_rsv_size;
block_rsv->qgroup_rsv_reserved = block_rsv->qgroup_rsv_size;
}
The temporary block rsv just has ->qgroup_rsv_reserved set,
->qgroup_rsv_size == 0. The optimization in
btrfs_insert_delayed_dir_index() sets ->qgroup_rsv_reserved = 0. Then
later on when we call btrfs_subvolume_release_metadata() which has
btrfs_block_rsv_release(fs_info, rsv, (u64)-1, &qgroup_to_release);
btrfs_qgroup_convert_reserved_meta(root, qgroup_to_release);
qgroup_to_release is set to 0, and we do not convert the reserved
metadata space.
The problem here is that the block rsv code has been unconditionally
messing with ->qgroup_rsv_reserved, because the main place this is used
is delalloc, and any time we call btrfs_block_rsv_release() we do it
with qgroup_to_release set, and thus do the proper accounting.
The subvolume code is the only other code that uses the qgroup
reservation stuff, but it's intermingled with the above optimization,
and thus was getting its reservation freed out from underneath it and
thus leaking the reserved space.
The solution is to simply not mess with the qgroup reservations if we
don't have qgroup_to_release set. This works with the existing code as
anything that messes with the delalloc reservations always have
qgroup_to_release set. This fixes the leak that Boris was observing.
Reviewed-by: Qu Wenruo <wqu@suse.com>
CC: stable@vger.kernel.org # 5.4+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e7db9e5c6b9615b287d01f0231904fbc1fbde9c5 upstream.
We have observed a btrfs filesystem corruption on workloads using
no-holes and encoded writes via send stream v2. The symptom is that a
file appears to be truncated to the end of its last aligned extent, even
though the final unaligned extent and even the file extent and otherwise
correctly updated inode item have been written.
So if we were writing out a 1MiB+X file via 8 128K extents and one
extent of length X, i_size would be set to 1MiB, but the ninth extent,
nbyte, etc. would all appear correct otherwise.
The source of the race is a narrow (one line of code) window in which a
no-holes fs has read in an updated i_size, but has not yet set a shared
disk_i_size variable to write. Therefore, if two ordered extents run in
parallel (par for the course for receive workloads), the following
sequence can play out: (following "threads" a bit loosely, since there
are callbacks involved for endio but extra threads aren't needed to
cause the issue)
ENC-WR1 (second to last) ENC-WR2 (last)
------- -------
btrfs_do_encoded_write
set i_size = 1M
submit bio B1 ending at 1M
endio B1
btrfs_inode_safe_disk_i_size_write
local i_size = 1M
falls off a cliff for some reason
btrfs_do_encoded_write
set i_size = 1M+X
submit bio B2 ending at 1M+X
endio B2
btrfs_inode_safe_disk_i_size_write
local i_size = 1M+X
disk_i_size = 1M+X
disk_i_size = 1M
btrfs_delayed_update_inode
btrfs_delayed_update_inode
And the delayed inode ends up filled with nbytes=1M+X and isize=1M, and
writes respect i_size and present a corrupted file missing its last
extents.
Fix this by holding the inode lock in the no-holes case so that a thread
can't sneak in a write to disk_i_size that gets overwritten with an out
of date i_size.
Fixes: 41a2ee75aab0 ("btrfs: introduce per-inode file extent tree")
CC: stable@vger.kernel.org # 5.10+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 631003e2333c12cc1b52df06a707365b7363a159 upstream.
find_next_bit and find_next_zero_bit take @size as the second parameter and
@offset as the third parameter. They are specified opposite in
btrfs_ensure_empty_zones(). Thanks to the later loop, it never failed to
detect the empty zones. Fix them and (maybe) return the result a bit
faster.
Note: the naming is a bit confusing, size has two meanings here, bitmap
and our range size.
Fixes: 1cd6121f2a38 ("btrfs: zoned: implement zoned chunk allocator")
CC: stable@vger.kernel.org # 5.15+
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6f932d4ef007d6a4ae03badcb749fbb8f49196f6 upstream.
A call to btrfs_prev_leaf() may end up returning a path that points to the
same item (key) again. This happens if while btrfs_prev_leaf(), after we
release the path, a concurrent insertion happens, which moves items off
from a sibling into the front of the previous leaf, and an item with the
computed previous key does not exists.
For example, suppose we have the two following leaves:
Leaf A
-------------------------------------------------------------
| ... key (300 96 10) key (300 96 15) key (300 96 16) |
-------------------------------------------------------------
slot 20 slot 21 slot 22
Leaf B
-------------------------------------------------------------
| key (300 96 20) key (300 96 21) key (300 96 22) ... |
-------------------------------------------------------------
slot 0 slot 1 slot 2
If we call btrfs_prev_leaf(), from btrfs_previous_item() for example, with
a path pointing to leaf B and slot 0 and the following happens:
1) At btrfs_prev_leaf() we compute the previous key to search as:
(300 96 19), which is a key that does not exists in the tree;
2) Then we call btrfs_release_path() at btrfs_prev_leaf();
3) Some other task inserts a key at leaf A, that sorts before the key at
slot 20, for example it has an objectid of 299. In order to make room
for the new key, the key at slot 22 is moved to the front of leaf B.
This happens at push_leaf_right(), called from split_leaf().
After this leaf B now looks like:
--------------------------------------------------------------------------------
| key (300 96 16) key (300 96 20) key (300 96 21) key (300 96 22) ... |
--------------------------------------------------------------------------------
slot 0 slot 1 slot 2 slot 3
4) At btrfs_prev_leaf() we call btrfs_search_slot() for the computed
previous key: (300 96 19). Since the key does not exists,
btrfs_search_slot() returns 1 and with a path pointing to leaf B
and slot 1, the item with key (300 96 20);
5) This makes btrfs_prev_leaf() return a path that points to slot 1 of
leaf B, the same key as before it was called, since the key at slot 0
of leaf B (300 96 16) is less than the computed previous key, which is
(300 96 19);
6) As a consequence btrfs_previous_item() returns a path that points again
to the item with key (300 96 20).
For some users of btrfs_prev_leaf() or btrfs_previous_item() this may not
be functional a problem, despite not making sense to return a new path
pointing again to the same item/key. However for a caller such as
tree-log.c:log_dir_items(), this has a bad consequence, as it can result
in not logging some dir index deletions in case the directory is being
logged without holding the inode's VFS lock (logging triggered while
logging a child inode for example) - for the example scenario above, in
case the dir index keys 17, 18 and 19 were deleted in the current
transaction.
CC: stable@vger.kernel.org # 4.14+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 604e6681e114d05a2e384c4d1e8ef81918037ef5 upstream.
Since the introduction of scrub interface, the only flag that we support
is BTRFS_SCRUB_READONLY. Thus there is no sanity checks, if there are
some undefined flags passed in, we just ignore them.
This is problematic if we want to introduce new scrub flags, as we have
no way to determine if such flags are supported.
Address the problem by introducing a check for the flags, and if
unsupported flags are set, return -EOPNOTSUPP to inform the user space.
This check should be backported for all supported kernels before any new
scrub flags are introduced.
CC: stable@vger.kernel.org # 4.14+
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 68d99ab0e9221ef54506f827576c5a914680eeaf upstream.
The BTRFS_FS_CSUM_IMPL_FAST flag is currently set whenever a non-generic
crc32c is detected, which is the incorrect check if the file system uses
a different checksumming algorithm. Refactor the code to only check
this if crc32c is actually used. Note that in an ideal world the
information if an algorithm is hardware accelerated or not should be
provided by the crypto API instead, but that's left for another day.
CC: stable@vger.kernel.org # 5.4.x: c8a5f8ca9a9c: btrfs: print checksum type and implementation at mount time
CC: stable@vger.kernel.org # 5.4.x
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c8a5f8ca9a9c7d5c5bc31d54f47ea9d86f93ed69 upstream.
Per user request, print the checksum type and implementation at mount
time among the messages. The checksum is user configurable and the
actual crypto implementation is useful to see for performance reasons.
The same information is also available after mount in
/sys/fs/FSID/checksum file.
Example:
[25.323662] BTRFS info (device vdb): using sha256 (sha256-generic) checksum algorithm
Link: https://github.com/kdave/btrfs-progs/issues/483
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 50d281fc434cb8e2497f5e70a309ccca6b1a09f0 upstream.
This fixes mkfs/mount/check failures due to race with systemd-udevd
scan.
During the device scan initiated by systemd-udevd, other user space
EXCL operations such as mkfs, mount, or check may get blocked and result
in a "Device or resource busy" error. This is because the device
scan process opens the device with the EXCL flag in the kernel.
Two reports were received:
- btrfs/179 test case, where the fsck command failed with the -EBUSY
error
- LTP pwritev03 test case, where mkfs.vfs failed with
the -EBUSY error, when mkfs.vfs tried to overwrite old btrfs filesystem
on the device.
In both cases, fsck and mkfs (respectively) were racing with a
systemd-udevd device scan, and systemd-udevd won, resulting in the
-EBUSY error for fsck and mkfs.
Reproducing the problem has been difficult because there is a very
small window during which these userspace threads can race to
acquire the exclusive device open. Even on the system where the problem
was observed, the problem occurrences were anywhere between 10 to 400
iterations and chances of reproducing decreases with debug printk()s.
However, an exclusive device open is unnecessary for the scan process,
as there are no write operations on the device during scan. Furthermore,
during the mount process, the superblock is re-read in the below
function call chain:
btrfs_mount_root
btrfs_open_devices
open_fs_devices
btrfs_open_one_device
btrfs_get_bdev_and_sb
So, to fix this issue, removes the FMODE_EXCL flag from the scan
operation, and add a comment.
The case where mkfs may still write to the device and a scan is running,
the btrfs signature is not written at that time so scan will not
recognize such device.
Reported-by: Sherry Yang <sherry.yang@oracle.com>
Reported-by: kernel test robot <oliver.sang@intel.com>
Link: https://lore.kernel.org/oe-lkp/202303170839.fdf23068-oliver.sang@intel.com
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 95cd356ca23c3807b5f3503687161e216b1c520d upstream.
We have a report, that the info message for block-group reclaim is
crossing the 100% used mark.
This is happening as we were truncating the divisor for the division
(the block_group->length) to a 32bit value.
Fix this by using div64_u64() to not truncate the divisor.
In the worst case, it can lead to a div by zero error and should be
possible to trigger on 4 disks RAID0, and each device is large enough:
$ mkfs.btrfs -f /dev/test/scratch[1234] -m raid1 -d raid0
btrfs-progs v6.1
[...]
Filesystem size: 40.00GiB
Block group profiles:
Data: RAID0 4.00GiB <<<
Metadata: RAID1 256.00MiB
System: RAID1 8.00MiB
Reported-by: Forza <forza@tnonline.net>
Link: https://lore.kernel.org/linux-btrfs/e99483.c11a58d.1863591ca52@tnonline.net/
Fixes: 5f93e776c673 ("btrfs: zoned: print unusable percentage when reclaiming block groups")
CC: stable@vger.kernel.org # 5.15+
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add Qu's note ]
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 2b5463fcbdfb24e898916bcae2b1359042d26963 upstream.
Async discard does not acquire the block group reference count while it
holds a reference on the discard list. This is generally OK, as the
paths which destroy block groups tend to try to synchronize on
cancelling async discard work. However, relying on cancelling work
requires careful analysis to be sure it is safe from races with
unpinning scheduling more work.
While I am unable to find a race with unpinning in the current code for
either the unused bgs or relocation paths, I believe we have one in an
older version of auto relocation in a Meta internal build. This suggests
that this is in fact an error prone model, and could be fragile to
future changes to these bg deletion paths.
To make this ownership more clear, add a refcount for async discard. If
work is queued for a block group, its refcount should be incremented,
and when work is completed or canceled, it should be decremented.
CC: stable@vger.kernel.org # 5.15+
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>