commit 2d8e5168d4 upstream.
Block group creation is done in two phases, which results in a slightly
unintuitive property: a block group can be allocated/deallocated from
after btrfs_make_block_group() adds it to the space_info with
btrfs_add_bg_to_space_info(), but before creation is completely completed
in btrfs_create_pending_block_groups(). As a result, it is possible for a
block group to go unused and have 'btrfs_mark_bg_unused' called on it
concurrently with 'btrfs_create_pending_block_groups'. This causes a
number of issues, which were fixed with the block group flag
'BLOCK_GROUP_FLAG_NEW'.
However, this fix is not quite complete. Since it does not use the
unused_bg_lock, it is possible for the following race to occur:
btrfs_create_pending_block_groups btrfs_mark_bg_unused
if list_empty // false
list_del_init
clear_bit
else if (test_bit) // true
list_move_tail
And we get into the exact same broken ref count and invalid new_bgs
state for transaction cleanup that BLOCK_GROUP_FLAG_NEW was designed to
prevent.
The broken refcount aspect will result in a warning like:
[1272.943527] refcount_t: underflow; use-after-free.
[1272.943967] WARNING: CPU: 1 PID: 61 at lib/refcount.c:28 refcount_warn_saturate+0xba/0x110
[1272.944731] Modules linked in: btrfs virtio_net xor zstd_compress raid6_pq null_blk [last unloaded: btrfs]
[1272.945550] CPU: 1 UID: 0 PID: 61 Comm: kworker/u32:1 Kdump: loaded Tainted: G W 6.14.0-rc5+ #108
[1272.946368] Tainted: [W]=WARN
[1272.946585] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014
[1272.947273] Workqueue: btrfs_discard btrfs_discard_workfn [btrfs]
[1272.947788] RIP: 0010:refcount_warn_saturate+0xba/0x110
[1272.949532] RSP: 0018:ffffbf1200247df0 EFLAGS: 00010282
[1272.949901] RAX: 0000000000000000 RBX: ffffa14b00e3f800 RCX: 0000000000000000
[1272.950437] RDX: 0000000000000000 RSI: ffffbf1200247c78 RDI: 00000000ffffdfff
[1272.950986] RBP: ffffa14b00dc2860 R08: 00000000ffffdfff R09: ffffffff90526268
[1272.951512] R10: ffffffff904762c0 R11: 0000000063666572 R12: ffffa14b00dc28c0
[1272.952024] R13: 0000000000000000 R14: ffffa14b00dc2868 R15: 000001285dcd12c0
[1272.952850] FS: 0000000000000000(0000) GS:ffffa14d33c40000(0000) knlGS:0000000000000000
[1272.953458] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[1272.953931] CR2: 00007f838cbda000 CR3: 000000010104e000 CR4: 00000000000006f0
[1272.954474] Call Trace:
[1272.954655] <TASK>
[1272.954812] ? refcount_warn_saturate+0xba/0x110
[1272.955173] ? __warn.cold+0x93/0xd7
[1272.955487] ? refcount_warn_saturate+0xba/0x110
[1272.955816] ? report_bug+0xe7/0x120
[1272.956103] ? handle_bug+0x53/0x90
[1272.956424] ? exc_invalid_op+0x13/0x60
[1272.956700] ? asm_exc_invalid_op+0x16/0x20
[1272.957011] ? refcount_warn_saturate+0xba/0x110
[1272.957399] btrfs_discard_cancel_work.cold+0x26/0x2b [btrfs]
[1272.957853] btrfs_put_block_group.cold+0x5d/0x8e [btrfs]
[1272.958289] btrfs_discard_workfn+0x194/0x380 [btrfs]
[1272.958729] process_one_work+0x130/0x290
[1272.959026] worker_thread+0x2ea/0x420
[1272.959335] ? __pfx_worker_thread+0x10/0x10
[1272.959644] kthread+0xd7/0x1c0
[1272.959872] ? __pfx_kthread+0x10/0x10
[1272.960172] ret_from_fork+0x30/0x50
[1272.960474] ? __pfx_kthread+0x10/0x10
[1272.960745] ret_from_fork_asm+0x1a/0x30
[1272.961035] </TASK>
[1272.961238] ---[ end trace 0000000000000000 ]---
Though we have seen them in the async discard workfn as well. It is
most likely to happen after a relocation finishes which cancels discard,
tears down the block group, etc.
Fix this fully by taking the lock around the list_del_init + clear_bit
so that the two are done atomically.
Fixes: 0657b20c5a ("btrfs: fix use-after-free of new block group that became unused")
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Alva Lan <alvalan9@foxmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 1961d20f6f ]
When building the free space tree with the block group tree feature
enabled, we can hit an assertion failure like this:
BTRFS info (device loop0 state M): rebuilding free space tree
assertion failed: ret == 0, in fs/btrfs/free-space-tree.c:1102
------------[ cut here ]------------
kernel BUG at fs/btrfs/free-space-tree.c:1102!
Internal error: Oops - BUG: 00000000f2000800 [#1] SMP
Modules linked in:
CPU: 1 UID: 0 PID: 6592 Comm: syz-executor322 Not tainted 6.15.0-rc7-syzkaller-gd7fa1af5b33e #0 PREEMPT
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : populate_free_space_tree+0x514/0x518 fs/btrfs/free-space-tree.c:1102
lr : populate_free_space_tree+0x514/0x518 fs/btrfs/free-space-tree.c:1102
sp : ffff8000a4ce7600
x29: ffff8000a4ce76e0 x28: ffff0000c9bc6000 x27: ffff0000ddfff3d8
x26: ffff0000ddfff378 x25: dfff800000000000 x24: 0000000000000001
x23: ffff8000a4ce7660 x22: ffff70001499cecc x21: ffff0000e1d8c160
x20: ffff0000e1cb7800 x19: ffff0000e1d8c0b0 x18: 00000000ffffffff
x17: ffff800092f39000 x16: ffff80008ad27e48 x15: ffff700011e740c0
x14: 1ffff00011e740c0 x13: 0000000000000004 x12: ffffffffffffffff
x11: ffff700011e740c0 x10: 0000000000ff0100 x9 : 94ef24f55d2dbc00
x8 : 94ef24f55d2dbc00 x7 : 0000000000000001 x6 : 0000000000000001
x5 : ffff8000a4ce6f98 x4 : ffff80008f415ba0 x3 : ffff800080548ef0
x2 : 0000000000000000 x1 : 0000000100000000 x0 : 000000000000003e
Call trace:
populate_free_space_tree+0x514/0x518 fs/btrfs/free-space-tree.c:1102 (P)
btrfs_rebuild_free_space_tree+0x14c/0x54c fs/btrfs/free-space-tree.c:1337
btrfs_start_pre_rw_mount+0xa78/0xe10 fs/btrfs/disk-io.c:3074
btrfs_remount_rw fs/btrfs/super.c:1319 [inline]
btrfs_reconfigure+0x828/0x2418 fs/btrfs/super.c:1543
reconfigure_super+0x1d4/0x6f0 fs/super.c:1083
do_remount fs/namespace.c:3365 [inline]
path_mount+0xb34/0xde0 fs/namespace.c:4200
do_mount fs/namespace.c:4221 [inline]
__do_sys_mount fs/namespace.c:4432 [inline]
__se_sys_mount fs/namespace.c:4409 [inline]
__arm64_sys_mount+0x3e8/0x468 fs/namespace.c:4409
__invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
el0_svc+0x58/0x17c arch/arm64/kernel/entry-common.c:767
el0t_64_sync_handler+0x78/0x108 arch/arm64/kernel/entry-common.c:786
el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600
Code: f0047182 91178042 528089c3 9771d47b (d4210000)
---[ end trace 0000000000000000 ]---
This happens because we are processing an empty block group, which has
no extents allocated from it, there are no items for this block group,
including the block group item since block group items are stored in a
dedicated tree when using the block group tree feature. It also means
this is the block group with the highest start offset, so there are no
higher keys in the extent root, hence btrfs_search_slot_for_read()
returns 1 (no higher key found).
Fix this by asserting 'ret' is 0 only if the block group tree feature
is not enabled, in which case we should find a block group item for
the block group since it's stored in the extent root and block group
item keys are greater than extent item keys (the value for
BTRFS_BLOCK_GROUP_ITEM_KEY is 192 and for BTRFS_EXTENT_ITEM_KEY and
BTRFS_METADATA_ITEM_KEY the values are 168 and 169 respectively).
In case 'ret' is 1, we just need to add a record to the free space
tree which spans the whole block group, and we can achieve this by
making 'ret == 0' as the while loop's condition.
Reported-by: syzbot+36fae25c35159a763a2a@syzkaller.appspotmail.com
Link: https://lore.kernel.org/linux-btrfs/6841dca8.a00a0220.d4325.0020.GAE@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 17a85f5204 ]
If we're doing a mmap write against a folio that has i_size somewhere in
the middle and we have multiple sectors in the folio, we may have to
release excess space previously reserved, for the range going from the
rounded up (to sector size) i_size to the folio's end offset. We are
calculating the right amount to release and passing it to
btrfs_delalloc_release_space(), but we are passing the wrong start offset
of that range - we're passing the folio's start offset instead of the
end offset, plus 1, of the range for which we keep the reservation. This
may result in releasing more space then we should and eventually trigger
an underflow of the data space_info's bytes_may_use counter.
So fix this by passing the start offset as 'end + 1' instead of
'page_start' to btrfs_delalloc_release_space().
Fixes: d0b7da88f6 ("Btrfs: btrfs_page_mkwrite: Reserve space in sectorsized units")
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 49990d8fa2 ]
This changes the assumption that the folio is always page sized.
(Although the ASSERT() for folio order is still kept as-is).
Just replace the PAGE_SIZE with folio_size().
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Stable-dep-of: 17a85f5204 ("btrfs: fix wrong start offset for delalloc space release during mmap write")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 157501b046 ]
We are setting the parent directory's last_unlink_trans directly which
may result in a concurrent task starting to log the directory not see the
update and therefore can log the directory after we removed a child
directory which had a snapshot within instead of falling back to a
transaction commit. Replaying such a log tree would result in a mount
failure since we can't currently delete snapshots (and subvolumes) during
log replay. This is the type of failure described in commit 1ec9a1ae1e
("Btrfs: fix unreplayable log after snapshot delete + parent dir fsync").
Fix this by using btrfs_record_snapshot_destroy() which updates the
last_unlink_trans field while holding the inode's log_mutex lock.
Fixes: 44f714dae5 ("Btrfs: improve performance on fsync against new inode after rename/unlink")
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit c466e33e72 ]
In case the removed directory had a snapshot that was deleted, we are
propagating its inode's last_unlink_trans to the parent directory after
we removed the entry from the parent directory. This leaves a small race
window where someone can log the parent directory after we removed the
entry and before we updated last_unlink_trans, and as a result if we ever
try to replay such a log tree, we will fail since we will attempt to
remove a snapshot during log replay, which is currently not possible and
results in the log replay (and mount) to fail. This is the type of failure
described in commit 1ec9a1ae1e ("Btrfs: fix unreplayable log after
snapshot delete + parent dir fsync").
So fix this by propagating the last_unlink_trans to the parent directory
before we remove the entry from it.
Fixes: 44f714dae5 ("Btrfs: improve performance on fsync against new inode after rename/unlink")
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit bf5bcf9a6f ]
Instead of recording that a new subvolume was created in a directory after
we add the entry do the directory, record it before adding the entry. This
is to avoid races where after creating the entry and before recording the
new subvolume in the directory (the call to btrfs_record_new_subvolume()),
another task logs the directory, so we end up with a log tree where we
logged a directory that has an entry pointing to a root that was not yet
committed, resulting in an invalid entry if the log is persisted and
replayed later due to a power failure or crash.
Also state this requirement in the function comment for
btrfs_record_new_subvolume(), similar to what we do for the
btrfs_record_unlink_dir() and btrfs_record_snapshot_destroy().
Fixes: 45c4102f0d ("btrfs: avoid transaction commit on any fsync after subvolume creation")
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 5f61b96159 ]
When replaying log trees we use read_one_inode() to get an inode, which is
just a wrapper around btrfs_iget_logging(), which in turn is a wrapper for
btrfs_iget(). But read_one_inode() always returns NULL for any error
that btrfs_iget_logging() / btrfs_iget() may return and this is a problem
because:
1) In many callers of read_one_inode() we convert the NULL into -EIO,
which is not accurate since btrfs_iget() may return -ENOMEM and -ENOENT
for example, besides -EIO and other errors. So during log replay we
may end up reporting a false -EIO, which is confusing since we may
not have had any IO error at all;
2) When replaying directory deletes, at replay_dir_deletes(), we assume
the NULL returned from read_one_inode() means that the inode doesn't
exist and then proceed as if no error had happened. This is wrong
because unless btrfs_iget() returned ERR_PTR(-ENOENT), we had an
actual error and the target inode may exist in the target subvolume
root - this may later result in the log replay code failing at a
later stage (if we are "lucky") or succeed but leaving some
inconsistency in the filesystem.
So fix this by not ignoring errors from btrfs_iget_logging() and as
a consequence remove the read_one_inode() wrapper and just use
btrfs_iget_logging() directly. Also since btrfs_iget_logging() is
supposed to be called only against subvolume roots, just like
read_one_inode() which had a comment about it, add an assertion to
btrfs_iget_logging() to check that the target root corresponds to a
subvolume root.
Fixes: 5d4f98a28c ("Btrfs: Mixed back reference (FORWARD ROLLING FORMAT CHANGE)")
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 2dcf838cf5 ]
In a few places where we call read_one_inode(), if we get a NULL pointer
we end up jumping into an error path, or fallthrough in case of
__add_inode_ref(), where we then do something like this:
iput(&inode->vfs_inode);
which results in an invalid inode pointer that triggers an invalid memory
access, resulting in a crash.
Fix this by making sure we don't do such dereferences.
Fixes: b4c50cbb01 ("btrfs: return a btrfs_inode from read_one_inode()")
CC: stable@vger.kernel.org # 6.15+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Stable-dep-of: 5f61b96159 ("btrfs: fix inode lookup error handling during log replay")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit b4c50cbb01 ]
All callers of read_one_inode() are mostly interested in the btrfs_inode
structure rather than the VFS inode, so make read_one_inode() return
the btrfs_inode instead, avoiding lots of BTRFS_I() calls.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Stable-dep-of: 5f61b96159 ("btrfs: fix inode lookup error handling during log replay")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit a488d8ac2c ]
All callers of btrfs_iget_logging() are interested in the btrfs_inode
structure rather than the VFS inode, so make btrfs_iget_logging() return
the btrfs_inode instead, avoiding lots of BTRFS_I() calls.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Stable-dep-of: 5f61b96159 ("btrfs: fix inode lookup error handling during log replay")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 54a7081ed1 ]
At __inode_add_ref() when processing extrefs, if we jump into the next
label we have an undefined value of victim_name.len, since we haven't
initialized it before we did the goto. This results in an invalid memory
access in the next iteration of the loop since victim_name.len was not
initialized to the length of the name of the current extref.
Fix this by initializing victim_name.len with the current extref's name
length.
Fixes: e43eec81c5 ("btrfs: use struct qstr instead of name and namelen pairs")
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 6561a40cec ]
During log replay, at __add_inode_ref(), when we are searching for inode
ref keys we totally ignore if btrfs_search_slot() returns an error. This
may make a log replay succeed when there was an actual error and leave
some metadata inconsistency in a subvolume tree. Fix this by checking if
an error was returned from btrfs_search_slot() and if so, return it to
the caller.
Fixes: e02119d5a7 ("Btrfs: Add a write ahead tree log to optimize synchronous operations")
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 59f37036bb ]
At btrfs_scan_root() we are accessing the inode's root (and fs_info) in a
call to btrfs_fs_closing() after we have scheduled the inode for a delayed
iput, and that can result in a use-after-free on the inode in case the
cleaner kthread does the iput before we dereference the inode in the call
to btrfs_fs_closing().
Fix this by using the fs_info stored already in a local variable instead
of doing inode->root->fs_info.
Fixes: 1020443840 ("btrfs: make the extent map shrinker run asynchronously as a work queue job")
CC: stable@vger.kernel.org # 6.13+
Tested-by: Ivan Shapovalov <intelfx@intelfx.name>
Link: https://lore.kernel.org/linux-btrfs/0414d690ac5680d0d77dfc930606cdc36e42e12f.camel@intelfx.name/
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 5a4041f2c4 ]
Running generic/751 on the for-next branch often results in a hang like
below. They are both stack by locking an extent. This suggests someone
forget to unlock an extent.
INFO: task kworker/u128:1:12 blocked for more than 323 seconds.
Not tainted 6.13.0-BTRFS-ZNS+ #503
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u128:1 state:D stack:0 pid:12 tgid:12 ppid:2 flags:0x00004000
Workqueue: btrfs-fixup btrfs_work_helper [btrfs]
Call Trace:
<TASK>
__schedule+0x534/0xdd0
schedule+0x39/0x140
__lock_extent+0x31b/0x380 [btrfs]
? __pfx_autoremove_wake_function+0x10/0x10
btrfs_writepage_fixup_worker+0xf1/0x3a0 [btrfs]
btrfs_work_helper+0xff/0x480 [btrfs]
? lock_release+0x178/0x2c0
process_one_work+0x1ee/0x570
? srso_return_thunk+0x5/0x5f
worker_thread+0x1d1/0x3b0
? __pfx_worker_thread+0x10/0x10
kthread+0x10b/0x230
? __pfx_kthread+0x10/0x10
ret_from_fork+0x30/0x50
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1a/0x30
</TASK>
INFO: task kworker/u134:0:184 blocked for more than 323 seconds.
Not tainted 6.13.0-BTRFS-ZNS+ #503
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u134:0 state:D stack:0 pid:184 tgid:184 ppid:2 flags:0x00004000
Workqueue: writeback wb_workfn (flush-btrfs-4)
Call Trace:
<TASK>
__schedule+0x534/0xdd0
schedule+0x39/0x140
__lock_extent+0x31b/0x380 [btrfs]
? __pfx_autoremove_wake_function+0x10/0x10
find_lock_delalloc_range+0xdb/0x260 [btrfs]
writepage_delalloc+0x12f/0x500 [btrfs]
? srso_return_thunk+0x5/0x5f
extent_write_cache_pages+0x232/0x840 [btrfs]
btrfs_writepages+0x72/0x130 [btrfs]
do_writepages+0xe7/0x260
? srso_return_thunk+0x5/0x5f
? lock_acquire+0xd2/0x300
? srso_return_thunk+0x5/0x5f
? find_held_lock+0x2b/0x80
? wbc_attach_and_unlock_inode.part.0+0x102/0x250
? wbc_attach_and_unlock_inode.part.0+0x102/0x250
__writeback_single_inode+0x5c/0x4b0
writeback_sb_inodes+0x22d/0x550
__writeback_inodes_wb+0x4c/0xe0
wb_writeback+0x2f6/0x3f0
wb_workfn+0x32a/0x510
process_one_work+0x1ee/0x570
? srso_return_thunk+0x5/0x5f
worker_thread+0x1d1/0x3b0
? __pfx_worker_thread+0x10/0x10
kthread+0x10b/0x230
? __pfx_kthread+0x10/0x10
ret_from_fork+0x30/0x50
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1a/0x30
</TASK>
This happens because we have another success path for the zoned mode. When
there is no active zone available, btrfs_reserve_extent() returns
-EAGAIN. In this case, we have two reactions.
(1) If the given range is never allocated, we can only wait for someone
to finish a zone, so wait on BTRFS_FS_NEED_ZONE_FINISH bit and retry
afterward.
(2) Or, if some allocations are already done, we must bail out and let
the caller to send IOs for the allocation. This is because these IOs
may be necessary to finish a zone.
The commit 06f3642847 ("btrfs: do proper folio cleanup when
cow_file_range() failed") moved the unlock code from the inside of the
loop to the outside. So, previously, the allocated extents are unlocked
just after the allocation and so before returning from the function.
However, they are no longer unlocked on the case (2) above. That caused
the hang issue.
Fix the issue by modifying the 'end' to the end of the allocated
range. Then, we can exit the loop and the same unlock code can properly
handle the case.
Reported-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Tested-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Fixes: 06f3642847 ("btrfs: do proper folio cleanup when cow_file_range() failed")
CC: stable@vger.kernel.org
Reviewed-by: Qu Wenruo <wqu@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>
[ Upstream commit 15b3b3254d ]
The extent map shrinker now runs in the system unbound workqueue and no
longer in kswapd context so it can directly do an iput() on inodes even
if that blocks or needs to acquire any lock (we aren't holding any locks
when requesting the delayed iput from the shrinker). So we don't need to
add a delayed iput, wake up the cleaner and delegate the iput() to the
cleaner, which also adds extra contention on the spinlock that protects
the delayed iputs list.
Reported-by: Ivan Shapovalov <intelfx@intelfx.name>
Tested-by: Ivan Shapovalov <intelfx@intelfx.name>
Link: https://lore.kernel.org/linux-btrfs/0414d690ac5680d0d77dfc930606cdc36e42e12f.camel@intelfx.name/
CC: stable@vger.kernel.org # 6.12+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 1020443840 ]
Currently the extent map shrinker is run synchronously for kswapd tasks
that end up calling the fs shrinker (fs/super.c:super_cache_scan()).
This has some disadvantages and for some heavy workloads with memory
pressure it can cause some delays and stalls that make a machine
unresponsive for some periods. This happens because:
1) We can have several kswapd tasks on machines with multiple NUMA zones,
and running the extent map shrinker concurrently can cause high
contention on some spin locks, namely the spin locks that protect
the radix tree that tracks roots, the per root xarray that tracks
open inodes and the list of delayed iputs. This not only delays the
shrinker but also causes high CPU consumption and makes the task
running the shrinker monopolize a core, resulting in the symptoms
of an unresponsive system. This was noted in previous commits such as
commit ae1e766f62 ("btrfs: only run the extent map shrinker from
kswapd tasks");
2) The extent map shrinker's iteration over inodes can often be slow, even
after changing the data structure that tracks open inodes for a root
from a red black tree (up to kernel 6.10) to an xarray (kernel 6.10+).
The transition to the xarray while it made things a bit faster, it's
still somewhat slow - for example in a test scenario with 10000 inodes
that have no extent maps loaded, the extent map shrinker took between
5ms to 8ms, using a release, non-debug kernel. Iterating over the
extent maps of an inode can also be slow if have an inode with many
thousands of extent maps, since we use a red black tree to track and
search extent maps. So having the extent map shrinker run synchronously
adds extra delay for other things a kswapd task does.
So make the extent map shrinker run asynchronously as a job for the
system unbounded workqueue, just like what we do for data and metadata
space reclaim jobs.
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: Sasha Levin <sashal@kernel.org>
[ Upstream commit c6c9c4d564 ]
If there are inodes that don't have any loaded extent maps, we end up
grabbing a reference on them and later adding a delayed iput, which wakes
up the cleaner and makes it do unnecessary work. This is common when for
example the inodes were open only to run stat(2) or all their extent maps
were already released through the folio release callback
(btrfs_release_folio()) or released by a previous run of the shrinker, or
directories which never have extent maps.
Reported-by: Ivan Shapovalov <intelfx@intelfx.name>
Tested-by: Ivan Shapovalov <intelfx@intelfx.name>
Link: https://lore.kernel.org/linux-btrfs/0414d690ac5680d0d77dfc930606cdc36e42e12f.camel@intelfx.name/
CC: stable@vger.kernel.org # 6.13+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 06f3642847 ]
[BUG]
When testing with COW fixup marked as BUG_ON() (this is involved with the
new pin_user_pages*() change, which should not result new out-of-band
dirty pages), I hit a crash triggered by the BUG_ON() from hitting COW
fixup path.
This BUG_ON() happens just after a failed btrfs_run_delalloc_range():
BTRFS error (device dm-2): failed to run delalloc range, root 348 ino 405 folio 65536 submit_bitmap 6-15 start 90112 len 106496: -28
------------[ cut here ]------------
kernel BUG at fs/btrfs/extent_io.c:1444!
Internal error: Oops - BUG: 00000000f2000800 [#1] SMP
CPU: 0 UID: 0 PID: 434621 Comm: kworker/u24:8 Tainted: G OE 6.12.0-rc7-custom+ #86
Hardware name: QEMU KVM Virtual Machine, BIOS unknown 2/2/2022
Workqueue: events_unbound btrfs_async_reclaim_data_space [btrfs]
pc : extent_writepage_io+0x2d4/0x308 [btrfs]
lr : extent_writepage_io+0x2d4/0x308 [btrfs]
Call trace:
extent_writepage_io+0x2d4/0x308 [btrfs]
extent_writepage+0x218/0x330 [btrfs]
extent_write_cache_pages+0x1d4/0x4b0 [btrfs]
btrfs_writepages+0x94/0x150 [btrfs]
do_writepages+0x74/0x190
filemap_fdatawrite_wbc+0x88/0xc8
start_delalloc_inodes+0x180/0x3b0 [btrfs]
btrfs_start_delalloc_roots+0x174/0x280 [btrfs]
shrink_delalloc+0x114/0x280 [btrfs]
flush_space+0x250/0x2f8 [btrfs]
btrfs_async_reclaim_data_space+0x180/0x228 [btrfs]
process_one_work+0x164/0x408
worker_thread+0x25c/0x388
kthread+0x100/0x118
ret_from_fork+0x10/0x20
Code: aa1403e1 9402f3ef aa1403e0 9402f36f (d4210000)
---[ end trace 0000000000000000 ]---
[CAUSE]
That failure is mostly from cow_file_range(), where we can hit -ENOSPC.
Although the -ENOSPC is already a bug related to our space reservation
code, let's just focus on the error handling.
For example, we have the following dirty range [0, 64K) of an inode,
with 4K sector size and 4K page size:
0 16K 32K 48K 64K
|///////////////////////////////////////|
|#######################################|
Where |///| means page are still dirty, and |###| means the extent io
tree has EXTENT_DELALLOC flag.
- Enter extent_writepage() for page 0
- Enter btrfs_run_delalloc_range() for range [0, 64K)
- Enter cow_file_range() for range [0, 64K)
- Function btrfs_reserve_extent() only reserved one 16K extent
So we created extent map and ordered extent for range [0, 16K)
0 16K 32K 48K 64K
|////////|//////////////////////////////|
|<- OE ->|##############################|
And range [0, 16K) has its delalloc flag cleared.
But since we haven't yet submit any bio, involved 4 pages are still
dirty.
- Function btrfs_reserve_extent() returns with -ENOSPC
Now we have to run error cleanup, which will clear all
EXTENT_DELALLOC* flags and clear the dirty flags for the remaining
ranges:
0 16K 32K 48K 64K
|////////| |
| | |
Note that range [0, 16K) still has its pages dirty.
- Some time later, writeback is triggered again for the range [0, 16K)
since the page range still has dirty flags.
- btrfs_run_delalloc_range() will do nothing because there is no
EXTENT_DELALLOC flag.
- extent_writepage_io() finds page 0 has no ordered flag
Which falls into the COW fixup path, triggering the BUG_ON().
Unfortunately this error handling bug dates back to the introduction of
btrfs. Thankfully with the abuse of COW fixup, at least it won't crash
the kernel.
[FIX]
Instead of immediately unlocking the extent and folios, we keep the extent
and folios locked until either erroring out or the whole delalloc range
finished.
When the whole delalloc range finished without error, we just unlock the
whole range with PAGE_SET_ORDERED (and PAGE_UNLOCK for !keep_locked
cases), with EXTENT_DELALLOC and EXTENT_LOCKED cleared.
And the involved folios will be properly submitted, with their dirty
flags cleared during submission.
For the error path, it will be a little more complex:
- The range with ordered extent allocated (range (1))
We only clear the EXTENT_DELALLOC and EXTENT_LOCKED, as the remaining
flags are cleaned up by
btrfs_mark_ordered_io_finished()->btrfs_finish_one_ordered().
For folios we finish the IO (clear dirty, start writeback and
immediately finish the writeback) and unlock the folios.
- The range with reserved extent but no ordered extent (range(2))
- The range we never touched (range(3))
For both range (2) and range(3) the behavior is not changed.
Now even if cow_file_range() failed halfway with some successfully
reserved extents/ordered extents, we will keep all folios clean, so
there will be no future writeback triggered on them.
CC: stable@vger.kernel.org
Reviewed-by: Boris Burkov <boris@bur.io>
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 ae4477f937 upstream.
Each superblock contains a copy of the device item for that device. In a
transaction which drops a chunk but doesn't create any new ones, we were
correctly updating the device item in the chunk tree but not copying
over the new bytes_used value to the superblock.
This can be seen by doing the following:
# dd if=/dev/zero of=test bs=4096 count=2621440
# mkfs.btrfs test
# mount test /root/temp
# cd /root/temp
# for i in {00..10}; do dd if=/dev/zero of=$i bs=4096 count=32768; done
# sync
# rm *
# sync
# btrfs balance start -dusage=0 .
# sync
# cd
# umount /root/temp
# btrfs check test
For btrfs-check to detect this, you will also need my patch at
https://github.com/kdave/btrfs-progs/pull/991.
Change btrfs_remove_dev_extents() so that it adds the devices to the
fs_info->post_commit_list if they're not there already. This causes
btrfs_commit_device_sizes() to be called, which updates the bytes_used
value in the superblock.
Fixes: bbbf7243d6 ("btrfs: combine device update operations during transaction commit")
CC: stable@vger.kernel.org # 5.10+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Mark Harmstone <maharmstone@fb.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 3ca864de85 upstream.
We have a race between a rename and directory inode logging that if it
happens and we crash/power fail before the rename completes, the next time
the filesystem is mounted, the log replay code will end up deleting the
file that was being renamed.
This is best explained following a step by step analysis of an interleaving
of steps that lead into this situation.
Consider the initial conditions:
1) We are at transaction N;
2) We have directories A and B created in a past transaction (< N);
3) We have inode X corresponding to a file that has 2 hardlinks, one in
directory A and the other in directory B, so we'll name them as
"A/foo_link1" and "B/foo_link2". Both hard links were persisted in a
past transaction (< N);
4) We have inode Y corresponding to a file that as a single hard link and
is located in directory A, we'll name it as "A/bar". This file was also
persisted in a past transaction (< N).
The steps leading to a file loss are the following and for all of them we
are under transaction N:
1) Link "A/foo_link1" is removed, so inode's X last_unlink_trans field
is updated to N, through btrfs_unlink() -> btrfs_record_unlink_dir();
2) Task A starts a rename for inode Y, with the goal of renaming from
"A/bar" to "A/baz", so we enter btrfs_rename();
3) Task A inserts the new BTRFS_INODE_REF_KEY for inode Y by calling
btrfs_insert_inode_ref();
4) Because the rename happens in the same directory, we don't set the
last_unlink_trans field of directoty A's inode to the current
transaction id, that is, we don't cal btrfs_record_unlink_dir();
5) Task A then removes the entries from directory A (BTRFS_DIR_ITEM_KEY
and BTRFS_DIR_INDEX_KEY items) when calling __btrfs_unlink_inode()
(actually the dir index item is added as a delayed item, but the
effect is the same);
6) Now before task A adds the new entry "A/baz" to directory A by
calling btrfs_add_link(), another task, task B is logging inode X;
7) Task B starts a fsync of inode X and after logging inode X, at
btrfs_log_inode_parent() it calls btrfs_log_all_parents(), since
inode X has a last_unlink_trans value of N, set at in step 1;
8) At btrfs_log_all_parents() we search for all parent directories of
inode X using the commit root, so we find directories A and B and log
them. Bu when logging direct A, we don't have a dir index item for
inode Y anymore, neither the old name "A/bar" nor for the new name
"A/baz" since the rename has deleted the old name but has not yet
inserted the new name - task A hasn't called yet btrfs_add_link() to
do that.
Note that logging directory A doesn't fallback to a transaction
commit because its last_unlink_trans has a lower value than the
current transaction's id (see step 4);
9) Task B finishes logging directories A and B and gets back to
btrfs_sync_file() where it calls btrfs_sync_log() to persist the log
tree;
10) Task B successfully persisted the log tree, btrfs_sync_log() completed
with success, and a power failure happened.
We have a log tree without any directory entry for inode Y, so the
log replay code deletes the entry for inode Y, name "A/bar", from the
subvolume tree since it doesn't exist in the log tree and the log
tree is authorative for its index (we logged a BTRFS_DIR_LOG_INDEX_KEY
item that covers the index range for the dentry that corresponds to
"A/bar").
Since there's no other hard link for inode Y and the log replay code
deletes the name "A/bar", the file is lost.
The issue wouldn't happen if task B synced the log only after task A
called btrfs_log_new_name(), which would update the log with the new name
for inode Y ("A/bar").
Fix this by pinning the log root during renames before removing the old
directory entry, and unpinning after btrfs_log_new_name() is called.
Fixes: 259c4b96d7 ("btrfs: stop doing unnecessary log updates during a rename")
CC: stable@vger.kernel.org # 5.18+
Reviewed-by: Boris Burkov <boris@bur.io>
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>
[ Upstream commit 1f2889f559 ]
If we fail to allocate an ordered extent for a COW write we end up leaking
a qgroup data reservation since we called btrfs_qgroup_release_data() but
we didn't call btrfs_qgroup_free_refroot() (which would happen when
running the respective data delayed ref created by ordered extent
completion or when finishing the ordered extent in case an error happened).
So make sure we call btrfs_qgroup_free_refroot() if we fail to allocate an
ordered extent for a COW write.
Fixes: 7dbeaad0af ("btrfs: change timing for qgroup reserved space for ordered extents to fix reserved space leak")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 05a6ec865d ]
The unsigned type is a recommended practice (CWE-190, CWE-194) for bit
shifts to avoid problems with potential unwanted sign extensions.
Although there are no such cases in btrfs codebase, follow the
recommendation.
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
Stable-dep-of: 1f2889f559 ("btrfs: fix qgroup reservation leak on failure to allocate ordered extent")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 10326fdcb3 ]
Currently we're doing all the ordered extent and extent map generation
inside a while() loop of run_delalloc_nocow(). This makes it pretty
hard to read, nor doing proper error handling.
So move that part of code into a helper, nocow_one_range().
This should not change anything, but there is a tiny timing change where
btrfs_dec_nocow_writers() is only called after nocow_one_range() helper
exits.
This timing change is small, and makes error handling easier, thus
should be fine.
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Stable-dep-of: 1f2889f559 ("btrfs: fix qgroup reservation leak on failure to allocate ordered extent")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 547e836661 ]
[BUG]
There is syzbot based reproducer that can crash the kernel, with the
following call trace: (With some debug output added)
DEBUG: rescue=ibadroots parsed
BTRFS: device fsid 14d642db-7b15-43e4-81e6-4b8fac6a25f8 devid 1 transid 8 /dev/loop0 (7:0) scanned by repro (1010)
BTRFS info (device loop0): first mount of filesystem 14d642db-7b15-43e4-81e6-4b8fac6a25f8
BTRFS info (device loop0): using blake2b (blake2b-256-generic) checksum algorithm
BTRFS info (device loop0): using free-space-tree
BTRFS warning (device loop0): checksum verify failed on logical 5312512 mirror 1 wanted 0xb043382657aede36608fd3386d6b001692ff406164733d94e2d9a180412c6003 found 0x810ceb2bacb7f0f9eb2bf3b2b15c02af867cb35ad450898169f3b1f0bd818651 level 0
DEBUG: read tree root path failed for tree csum, ret=-5
BTRFS warning (device loop0): checksum verify failed on logical 5328896 mirror 1 wanted 0x51be4e8b303da58e6340226815b70e3a93592dac3f30dd510c7517454de8567a found 0x51be4e8b303da58e634022a315b70e3a93592dac3f30dd510c7517454de8567a level 0
BTRFS warning (device loop0): checksum verify failed on logical 5292032 mirror 1 wanted 0x1924ccd683be9efc2fa98582ef58760e3848e9043db8649ee382681e220cdee4 found 0x0cb6184f6e8799d9f8cb335dccd1d1832da1071d12290dab3b85b587ecacca6e level 0
process 'repro' launched './file2' with NULL argv: empty string added
DEBUG: no csum root, idatacsums=0 ibadroots=134217728
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000041: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000208-0x000000000000020f]
CPU: 5 UID: 0 PID: 1010 Comm: repro Tainted: G OE 6.15.0-custom+ #249 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS unknown 02/02/2022
RIP: 0010:btrfs_lookup_csum+0x93/0x3d0 [btrfs]
Call Trace:
<TASK>
btrfs_lookup_bio_sums+0x47a/0xdf0 [btrfs]
btrfs_submit_bbio+0x43e/0x1a80 [btrfs]
submit_one_bio+0xde/0x160 [btrfs]
btrfs_readahead+0x498/0x6a0 [btrfs]
read_pages+0x1c3/0xb20
page_cache_ra_order+0x4b5/0xc20
filemap_get_pages+0x2d3/0x19e0
filemap_read+0x314/0xde0
__kernel_read+0x35b/0x900
bprm_execve+0x62e/0x1140
do_execveat_common.isra.0+0x3fc/0x520
__x64_sys_execveat+0xdc/0x130
do_syscall_64+0x54/0x1d0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
---[ end trace 0000000000000000 ]---
[CAUSE]
Firstly the fs has a corrupted csum tree root, thus to mount the fs we
have to go "ro,rescue=ibadroots" mount option.
Normally with that mount option, a bad csum tree root should set
BTRFS_FS_STATE_NO_DATA_CSUMS flag, so that any future data read will
ignore csum search.
But in this particular case, we have the following call trace that
caused NULL csum root, but not setting BTRFS_FS_STATE_NO_DATA_CSUMS:
load_global_roots_objectid():
ret = btrfs_search_slot();
/* Succeeded */
btrfs_item_key_to_cpu()
found = true;
/* We found the root item for csum tree. */
root = read_tree_root_path();
if (IS_ERR(root)) {
if (!btrfs_test_opt(fs_info, IGNOREBADROOTS))
/*
* Since we have rescue=ibadroots mount option,
* @ret is still 0.
*/
break;
if (!found || ret) {
/* @found is true, @ret is 0, error handling for csum
* tree is skipped.
*/
}
This means we completely skipped to set BTRFS_FS_STATE_NO_DATA_CSUMS if
the csum tree is corrupted, which results unexpected later csum lookup.
[FIX]
If read_tree_root_path() failed, always populate @ret to the error
number.
As at the end of the function, we need @ret to determine if we need to
do the extra error handling for csum tree.
Fixes: abed4aaae4 ("btrfs: track the csum, extent, and free space trees in a rb tree")
Reported-by: Zhiyu Zhang <zhiyuzhang999@gmail.com>
Reported-by: Longxing Li <coregee2000@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 41d69d4d78 ]
If split_state() returned an error we call extent_io_tree_panic() which
will trigger a BUG() call. However if CONFIG_BUG is disabled, which is an
uncommon and exotic scenario, then we fallthrough and hit a use after free
when calling set_state_bits() since the extent state record which the
local variable 'prealloc' points to was freed by split_state().
So jump to the label 'out' after calling extent_io_tree_panic() and set
the 'prealloc' pointer to NULL since split_state() has already freed it
when it hit an error.
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 3bf179e36d ]
If insert_state() state failed it returns an error pointer and we call
extent_io_tree_panic() which will trigger a BUG() call. However if
CONFIG_BUG is disabled, which is an uncommon and exotic scenario, then
we fallthrough and call cache_state() which will dereference the error
pointer, resulting in an invalid memory access.
So jump to the 'out' label after calling extent_io_tree_panic(), it also
makes the code more clear besides dealing with the exotic scenario where
CONFIG_BUG is disabled.
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 d3914d6030 ]
If when truncating a block we fail to reserve data space and then we
proceed anyway because we can do a NOCOW write, if we later get an error
when trying to get the folio from the inode's mapping, we end up releasing
data space that we haven't reserved, screwing up the bytes_may_use counter
from the data space_info, eventually resulting in an underflow when all
other reservations done by other tasks are released, if any, or right away
if there are no other reservations at the moment.
This is because when we get an error when trying to grab the block's folio
we call btrfs_delalloc_release_space(), which releases metadata (which we
have reserved) and data (which we haven't reserved).
Fix this by calling btrfs_delalloc_release_space() only if we did reserve
data space, that is, if we aren't falling back to NOCOW, meaning the local
variable @only_release_metadata has a false value, otherwise release only
metadata by calling btrfs_delalloc_release_metadata().
Fixes: 6d4572a9d7 ("btrfs: allow btrfs_truncate_block() to fallback to nocow for data space reservation")
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit f2c19541e4 ]
When the bytenr doesn't match for a metadata tree block, we will report
it as an csum error, which is incorrect and should be reported as a
metadata error instead.
Fixes: a3ddbaebc7 ("btrfs: scrub: introduce a helper to verify one metadata block")
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>
[ Upstream commit ec1f3a207c ]
[BUG]
Since the migration to the new scrub_stripe interface, scrub no longer
updates the device stats when hitting an error, no matter if it's a read
or checksum mismatch error. E.g:
BTRFS info (device dm-2): scrub: started on devid 1
BTRFS error (device dm-2): unable to fixup (regular) error at logical 13631488 on dev /dev/mapper/test-scratch1 physical 13631488
BTRFS warning (device dm-2): checksum error at logical 13631488 on dev /dev/mapper/test-scratch1, physical 13631488, root 5, inode 257, offset 0, length 4096, links 1 (path: file)
BTRFS error (device dm-2): unable to fixup (regular) error at logical 13631488 on dev /dev/mapper/test-scratch1 physical 13631488
BTRFS warning (device dm-2): checksum error at logical 13631488 on dev /dev/mapper/test-scratch1, physical 13631488, root 5, inode 257, offset 0, length 4096, links 1 (path: file)
BTRFS info (device dm-2): scrub: finished on devid 1 with status: 0
Note there is no line showing the device stats error update.
[CAUSE]
In the migration to the new scrub_stripe interface, we no longer call
btrfs_dev_stat_inc_and_print().
[FIX]
- Introduce a new bitmap for metadata generation errors
* A new bitmap
@meta_gen_error_bitmap is introduced to record which blocks have
metadata generation mismatch errors.
* A new counter for that bitmap
@init_nr_meta_gen_errors, is also introduced to store the number of
generation mismatch errors that are found during the initial read.
This is for the error reporting at scrub_stripe_report_errors().
* New dedicated error message for unrepaired generation mismatches
* Update @meta_gen_error_bitmap if a transid mismatch is hit
- Add btrfs_dev_stat_inc_and_print() calls to the following call sites
* scrub_stripe_report_errors()
* scrub_write_endio()
This is only for the write errors.
This means there is a minor behavior change:
- The timing of device stats error message
Since we concentrate the error messages at
scrub_stripe_report_errors(), the device stats error messages will all
show up in one go, after the detailed scrub error messages:
BTRFS error (device dm-2): unable to fixup (regular) error at logical 13631488 on dev /dev/mapper/test-scratch1 physical 13631488
BTRFS warning (device dm-2): checksum error at logical 13631488 on dev /dev/mapper/test-scratch1, physical 13631488, root 5, inode 257, offset 0, length 4096, links 1 (path: file)
BTRFS error (device dm-2): unable to fixup (regular) error at logical 13631488 on dev /dev/mapper/test-scratch1 physical 13631488
BTRFS warning (device dm-2): checksum error at logical 13631488 on dev /dev/mapper/test-scratch1, physical 13631488, root 5, inode 257, offset 0, length 4096, links 1 (path: file)
BTRFS error (device dm-2): bdev /dev/mapper/test-scratch1 errs: wr 0, rd 0, flush 0, corrupt 1, gen 0
BTRFS error (device dm-2): bdev /dev/mapper/test-scratch1 errs: wr 0, rd 0, flush 0, corrupt 2, gen 0
Fixes: e02ee89baa ("btrfs: scrub: switch scrub_simple_mirror() to scrub_stripe infrastructure")
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: Sasha Levin <sashal@kernel.org>
[ Upstream commit f95d186255 ]
[BUG]
When trying read-only scrub on a btrfs with rescue=idatacsums mount
option, it will crash with the following call trace:
BUG: kernel NULL pointer dereference, address: 0000000000000208
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
CPU: 1 UID: 0 PID: 835 Comm: btrfs Tainted: G O 6.15.0-rc3-custom+ #236 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS unknown 02/02/2022
RIP: 0010:btrfs_lookup_csums_bitmap+0x49/0x480 [btrfs]
Call Trace:
<TASK>
scrub_find_fill_first_stripe+0x35b/0x3d0 [btrfs]
scrub_simple_mirror+0x175/0x290 [btrfs]
scrub_stripe+0x5f7/0x6f0 [btrfs]
scrub_chunk+0x9a/0x150 [btrfs]
scrub_enumerate_chunks+0x333/0x660 [btrfs]
btrfs_scrub_dev+0x23e/0x600 [btrfs]
btrfs_ioctl+0x1dcf/0x2f80 [btrfs]
__x64_sys_ioctl+0x97/0xc0
do_syscall_64+0x4f/0x120
entry_SYSCALL_64_after_hwframe+0x76/0x7e
[CAUSE]
Mount option "rescue=idatacsums" will completely skip loading the csum
tree, so that any data read will not find any data csum thus we will
ignore data checksum verification.
Normally call sites utilizing csum tree will check the fs state flag
NO_DATA_CSUMS bit, but unfortunately scrub does not check that bit at all.
This results in scrub to call btrfs_search_slot() on a NULL pointer
and triggered above crash.
[FIX]
Check both extent and csum tree root before doing any tree search.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d6fe0c69b3 ]
num_extent_folios() unconditionally calls folio_order() on
eb->folios[0]. If that is NULL this will be a segfault. It is reasonable
for it to return 0 as the number of folios in the eb when the first
entry is NULL, so do that instead.
Reviewed-by: Qu Wenruo <wqu@suse.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: Sasha Levin <sashal@kernel.org>
[ Upstream commit 6f9a8ab796 ]
In preparation for making the kmalloc() family of allocators type aware,
we need to make sure that the returned type from the allocation matches
the type of the variable being assigned. (Before, the allocator would
always return "void *", which can be implicitly cast to any pointer type.)
The assigned type is "struct folio **" but the returned type will be
"struct page **". These are the same allocation size (pointer size), but
the types don't match. Adjust the allocation type to match the assignment.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Kees Cook <kees@kernel.org>
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 a77749b3e2 ]
When attempting to build a too long path we are currently returning
-ENOMEM, which is very odd and misleading. So update fs_path_ensure_buf()
to return -ENAMETOOLONG instead. Also, while at it, move the WARN_ON()
into the if statement's expression, as it makes it clear what is being
tested and also has the effect of adding 'unlikely' to the statement,
which allows the compiler to generate better code as this condition is
never expected to happen.
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 1283b8c125 ]
At btrfs_reclaim_bgs_work(), we are grabbing a block group's zone unusable
bytes while not under the protection of the block group's spinlock, so
this can trigger race reports from KCSAN (or similar tools) since that
field is typically updated while holding the lock, such as at
__btrfs_add_free_space_zoned() for example.
Fix this by grabbing the zone unusable bytes while we are still in the
critical section holding the block group's spinlock, which is right above
where we are currently grabbing it.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.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 cda76788f8 ]
At close_ctree() after we have ran delayed iputs either explicitly through
calling btrfs_run_delayed_iputs() or later during the call to
btrfs_commit_super() or btrfs_error_commit_super(), we assert that the
delayed iputs list is empty.
We have (another) race where this assertion might fail because we have
queued an async write into the fs_info->workers workqueue. Here's how it
happens:
1) We are submitting a data bio for an inode that is not the data
relocation inode, so we call btrfs_wq_submit_bio();
2) btrfs_wq_submit_bio() submits a work for the fs_info->workers queue
that will run run_one_async_done();
3) We enter close_ctree(), flush several work queues except
fs_info->workers, explicitly run delayed iputs with a call to
btrfs_run_delayed_iputs() and then again shortly after by calling
btrfs_commit_super() or btrfs_error_commit_super(), which also run
delayed iputs;
4) run_one_async_done() is executed in the work queue, and because there
was an IO error (bio->bi_status is not 0) it calls btrfs_bio_end_io(),
which drops the final reference on the associated ordered extent by
calling btrfs_put_ordered_extent() - and that adds a delayed iput for
the inode;
5) At close_ctree() we find that after stopping the cleaner and
transaction kthreads the delayed iputs list is not empty, failing the
following assertion:
ASSERT(list_empty(&fs_info->delayed_iputs));
Fix this by flushing the fs_info->workers workqueue before running delayed
iputs at close_ctree().
David reported this when running generic/648, which exercises IO error
paths by using the DM error table.
Reported-by: David Sterba <dsterba@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit df94a342ef ]
[BUG]
Even after all the error fixes related the
"ASSERT(list_empty(&fs_info->delayed_iputs));" in close_ctree(), I can
still hit it reliably with my experimental 2K block size.
[CAUSE]
In my case, all the error is triggered after the fs is already in error
status.
I find the following call trace to be the cause of race:
Main thread | endio_write_workers
---------------------------------------------+---------------------------
close_ctree() |
|- btrfs_error_commit_super() |
| |- btrfs_cleanup_transaction() |
| | |- btrfs_destroy_all_ordered_extents() |
| | |- btrfs_wait_ordered_roots() |
| |- btrfs_run_delayed_iputs() |
| | btrfs_finish_ordered_io()
| | |- btrfs_put_ordered_extent()
| | |- btrfs_add_delayed_iput()
|- ASSERT(list_empty(delayed_iputs)) |
!!! Triggered !!!
The root cause is that, btrfs_wait_ordered_roots() only wait for
ordered extents to finish their IOs, not to wait for them to finish and
removed.
[FIX]
Since btrfs_error_commit_super() will flush and wait for all ordered
extents, it should be executed early, before we start flushing the
workqueues.
And since btrfs_error_commit_super() now runs early, there is no need to
run btrfs_run_delayed_iputs() inside it, so just remove the
btrfs_run_delayed_iputs() call from btrfs_error_commit_super().
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: Sasha Levin <sashal@kernel.org>
[ Upstream commit 7ef3cbf17d ]
The inline function btrfs_is_testing() is hardcoded to return 0 if
CONFIG_BTRFS_FS_RUN_SANITY_TESTS is not set. Currently we're relying on
the compiler optimizing out the call to alloc_test_extent_buffer() in
btrfs_find_create_tree_block(), as it's not been defined (it's behind an
#ifdef).
Add a stub version of alloc_test_extent_buffer() to avoid linker errors
on non-standard optimization levels. This problem was seen on GCC 14
with -O0 and is helps to see symbols that would be otherwise optimized
out.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Mark Harmstone <maharmstone@fb.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 895c6721d3 ]
Currently, the async discard machinery owns a ref to the block_group
when the block_group is queued on a discard list. However, to handle
races with discard cancellation and the discard workfn, we have a
specific logic to detect that the block_group is *currently* running in
the workfn, to protect the workfn's usage amidst cancellation.
As far as I can tell, this doesn't have any overt bugs (though
finish_discard_pass() and remove_from_discard_list() racing can have a
surprising outcome for the caller of remove_from_discard_list() in that
it is again added at the end).
But it is needlessly complicated to rely on locking and the nullity of
discard_ctl->block_group. Simplify this significantly by just taking a
refcount while we are in the workfn and unconditionally drop it in both
the remove and workfn paths, regardless of if they race.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 4ce2affc6e upstream.
The Btrfs documentation states that if the commit value is greater than
300 a warning should be issued. The warning was accidentally lost in the
new mount API update.
Fixes: 6941823cc8 ("btrfs: remove old mount API code")
CC: stable@vger.kernel.org # 6.12+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Kyoji Ogasawara <sawara04.o@gmail.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 a0fd1c6098 upstream.
If btrfs_reserve_extent() fails while submitting an async_extent for a
compressed write, then we fail to call free_async_extent_pages() on the
async_extent and leak its folios. A likely cause for such a failure
would be btrfs_reserve_extent() failing to find a large enough
contiguous free extent for the compressed extent.
I was able to reproduce this by:
1. mount with compress-force=zstd:3
2. fallocating most of a filesystem to a big file
3. fragmenting the remaining free space
4. trying to copy in a file which zstd would generate large compressed
extents for (vmlinux worked well for this)
Step 4. hits the memory leak and can be repeated ad nauseam to
eventually exhaust the system memory.
Fix this by detecting the case where we fallback to uncompressed
submission for a compressed async_extent and ensuring that we call
free_async_extent_pages().
Fixes: 131a821a24 ("btrfs: fallback if compressed IO fails for ENOSPC")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Co-developed-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 54db6d1bdd upstream.
If the discard worker is running and there's currently only one block
group, that block group is a data block group, it's in the unused block
groups discard list and is being used (it got an extent allocated from it
after becoming unused), the worker can end up in an infinite loop if a
transaction abort happens or the async discard is disabled (during remount
or unmount for example).
This happens like this:
1) Task A, the discard worker, is at peek_discard_list() and
find_next_block_group() returns block group X;
2) Block group X is in the unused block groups discard list (its discard
index is BTRFS_DISCARD_INDEX_UNUSED) since at some point in the past
it become an unused block group and was added to that list, but then
later it got an extent allocated from it, so its ->used counter is not
zero anymore;
3) The current transaction is aborted by task B and we end up at
__btrfs_handle_fs_error() in the transaction abort path, where we call
btrfs_discard_stop(), which clears BTRFS_FS_DISCARD_RUNNING from
fs_info, and then at __btrfs_handle_fs_error() we set the fs to RO mode
(setting SB_RDONLY in the super block's s_flags field);
4) Task A calls __add_to_discard_list() with the goal of moving the block
group from the unused block groups discard list into another discard
list, but at __add_to_discard_list() we end up doing nothing because
btrfs_run_discard_work() returns false, since the super block has
SB_RDONLY set in its flags and BTRFS_FS_DISCARD_RUNNING is not set
anymore in fs_info->flags. So block group X remains in the unused block
groups discard list;
5) Task A then does a goto into the 'again' label, calls
find_next_block_group() again we gets block group X again. Then it
repeats the previous steps over and over since there are not other
block groups in the discard lists and block group X is never moved
out of the unused block groups discard list since
btrfs_run_discard_work() keeps returning false and therefore
__add_to_discard_list() doesn't move block group X out of that discard
list.
When this happens we can get a soft lockup report like this:
[71.957] watchdog: BUG: soft lockup - CPU#0 stuck for 27s! [kworker/u4:3:97]
[71.957] Modules linked in: xfs af_packet rfkill (...)
[71.957] CPU: 0 UID: 0 PID: 97 Comm: kworker/u4:3 Tainted: G W 6.14.2-1-default #1 openSUSE Tumbleweed 968795ef2b1407352128b466fe887416c33af6fa
[71.957] Tainted: [W]=WARN
[71.957] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.2-3-gd478f380-rebuilt.opensuse.org 04/01/2014
[71.957] Workqueue: btrfs_discard btrfs_discard_workfn [btrfs]
[71.957] RIP: 0010:btrfs_discard_workfn+0xc4/0x400 [btrfs]
[71.957] Code: c1 01 48 83 (...)
[71.957] RSP: 0018:ffffafaec03efe08 EFLAGS: 00000246
[71.957] RAX: ffff897045500000 RBX: ffff8970413ed8d0 RCX: 0000000000000000
[71.957] RDX: 0000000000000001 RSI: ffff8970413ed8d0 RDI: 0000000a8f1272ad
[71.957] RBP: 0000000a9d61c60e R08: ffff897045500140 R09: 8080808080808080
[71.957] R10: ffff897040276800 R11: fefefefefefefeff R12: ffff8970413ed860
[71.957] R13: ffff897045500000 R14: ffff8970413ed868 R15: 0000000000000000
[71.957] FS: 0000000000000000(0000) GS:ffff89707bc00000(0000) knlGS:0000000000000000
[71.957] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[71.957] CR2: 00005605bcc8d2f0 CR3: 000000010376a001 CR4: 0000000000770ef0
[71.957] PKRU: 55555554
[71.957] Call Trace:
[71.957] <TASK>
[71.957] process_one_work+0x17e/0x330
[71.957] worker_thread+0x2ce/0x3f0
[71.957] ? __pfx_worker_thread+0x10/0x10
[71.957] kthread+0xef/0x220
[71.957] ? __pfx_kthread+0x10/0x10
[71.957] ret_from_fork+0x34/0x50
[71.957] ? __pfx_kthread+0x10/0x10
[71.957] ret_from_fork_asm+0x1a/0x30
[71.957] </TASK>
[71.957] Kernel panic - not syncing: softlockup: hung tasks
[71.987] CPU: 0 UID: 0 PID: 97 Comm: kworker/u4:3 Tainted: G W L 6.14.2-1-default #1 openSUSE Tumbleweed 968795ef2b1407352128b466fe887416c33af6fa
[71.989] Tainted: [W]=WARN, [L]=SOFTLOCKUP
[71.989] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.2-3-gd478f380-rebuilt.opensuse.org 04/01/2014
[71.991] Workqueue: btrfs_discard btrfs_discard_workfn [btrfs]
[71.992] Call Trace:
[71.993] <IRQ>
[71.994] dump_stack_lvl+0x5a/0x80
[71.994] panic+0x10b/0x2da
[71.995] watchdog_timer_fn.cold+0x9a/0xa1
[71.996] ? __pfx_watchdog_timer_fn+0x10/0x10
[71.997] __hrtimer_run_queues+0x132/0x2a0
[71.997] hrtimer_interrupt+0xff/0x230
[71.998] __sysvec_apic_timer_interrupt+0x55/0x100
[71.999] sysvec_apic_timer_interrupt+0x6c/0x90
[72.000] </IRQ>
[72.000] <TASK>
[72.001] asm_sysvec_apic_timer_interrupt+0x1a/0x20
[72.002] RIP: 0010:btrfs_discard_workfn+0xc4/0x400 [btrfs]
[72.002] Code: c1 01 48 83 (...)
[72.005] RSP: 0018:ffffafaec03efe08 EFLAGS: 00000246
[72.006] RAX: ffff897045500000 RBX: ffff8970413ed8d0 RCX: 0000000000000000
[72.006] RDX: 0000000000000001 RSI: ffff8970413ed8d0 RDI: 0000000a8f1272ad
[72.007] RBP: 0000000a9d61c60e R08: ffff897045500140 R09: 8080808080808080
[72.008] R10: ffff897040276800 R11: fefefefefefefeff R12: ffff8970413ed860
[72.009] R13: ffff897045500000 R14: ffff8970413ed868 R15: 0000000000000000
[72.010] ? btrfs_discard_workfn+0x51/0x400 [btrfs 23b01089228eb964071fb7ca156eee8cd3bf996f]
[72.011] process_one_work+0x17e/0x330
[72.012] worker_thread+0x2ce/0x3f0
[72.013] ? __pfx_worker_thread+0x10/0x10
[72.014] kthread+0xef/0x220
[72.014] ? __pfx_kthread+0x10/0x10
[72.015] ret_from_fork+0x34/0x50
[72.015] ? __pfx_kthread+0x10/0x10
[72.016] ret_from_fork_asm+0x1a/0x30
[72.017] </TASK>
[72.017] Kernel Offset: 0x15000000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
[72.019] Rebooting in 90 seconds..
So fix this by making sure we move a block group out of the unused block
groups discard list when calling __add_to_discard_list().
Fixes: 2bee7eb8bb ("btrfs: discard one region at a time in async discard")
Link: https://bugzilla.suse.com/show_bug.cgi?id=1242012
CC: stable@vger.kernel.org # 5.10+
Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Daniel Vacek <neelx@suse.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 8fb1dcbbcc upstream.
This reverts commit 7e06de7c83.
Commit 7e06de7c83 ("btrfs: canonicalize the device path before adding
it") tries to make btrfs to use "/dev/mapper/*" name first, then any
filename inside "/dev/" as the device path.
This is mostly fine when there is only the root namespace involved, but
when multiple namespace are involved, things can easily go wrong for the
d_path() usage.
As d_path() returns a file path that is namespace dependent, the
resulted string may not make any sense in another namespace.
Furthermore, the "/dev/" prefix checks itself is not reliable, one can
still make a valid initramfs without devtmpfs, and fill all needed
device nodes manually.
Overall the userspace has all its might to pass whatever device path for
mount, and we are not going to win the war trying to cover every corner
case.
So just revert that commit, and do no extra d_path() based file path
sanity check.
CC: stable@vger.kernel.org # 6.12+
Link: https://lore.kernel.org/linux-fsdevel/20250115185608.GA2223535@zen.localdomain/
Reviewed-by: Boris Burkov <boris@bur.io>
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 be3f1938d3 upstream.
In run_delalloc_nocow(), when the found btrfs_key's offset > cur_offset,
it indicates a gap between the current processing region and
the next file extent. The original code would directly jump to
the "must_cow" label, which increments the slot and forces a fallback
to COW. This behavior might skip an extent item and result in an
overestimated COW fallback range.
This patch modifies the logic so that when a gap is detected:
- If no COW range is already being recorded (cow_start is unset),
cow_start is set to cur_offset.
- cur_offset is then advanced to the beginning of the next extent.
- Instead of jumping to "must_cow", control flows directly to
"next_slot" so that the same extent item can be reexamined properly.
The change ensures that we accurately account for the extent gap and
avoid accidentally extending the range that needs to fallback to COW.
CC: stable@vger.kernel.org # 6.6+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Dave Chen <davechen@synology.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e08e49d986 upstream.
When running machines with 64k page size and a 16k nodesize we started
seeing tree log corruption in production. This turned out to be because
we were not writing out dirty blocks sometimes, so this in fact affects
all metadata writes.
When writing out a subpage EB we scan the subpage bitmap for a dirty
range. If the range isn't dirty we do
bit_start++;
to move onto the next bit. The problem is the bitmap is based on the
number of sectors that an EB has. So in this case, we have a 64k
pagesize, 16k nodesize, but a 4k sectorsize. This means our bitmap is 4
bits for every node. With a 64k page size we end up with 4 nodes per
page.
To make this easier this is how everything looks
[0 16k 32k 48k ] logical address
[0 4 8 12 ] radix tree offset
[ 64k page ] folio
[ 16k eb ][ 16k eb ][ 16k eb ][ 16k eb ] extent buffers
[ | | | | | | | | | | | | | | | | ] bitmap
Now we use all of our addressing based on fs_info->sectorsize_bits, so
as you can see the above our 16k eb->start turns into radix entry 4.
When we find a dirty range for our eb, we correctly do bit_start +=
sectors_per_node, because if we start at bit 0, the next bit for the
next eb is 4, to correspond to eb->start 16k.
However if our range is clean, we will do bit_start++, which will now
put us offset from our radix tree entries.
In our case, assume that the first time we check the bitmap the block is
not dirty, we increment bit_start so now it == 1, and then we loop
around and check again. This time it is dirty, and we go to find that
start using the following equation
start = folio_start + bit_start * fs_info->sectorsize;
so in the case above, eb->start 0 is now dirty, and we calculate start
as
0 + 1 * fs_info->sectorsize = 4096
4096 >> 12 = 1
Now we're looking up the radix tree for 1, and we won't find an eb.
What's worse is now we're using bit_start == 1, so we do bit_start +=
sectors_per_node, which is now 5. If that eb is dirty we will run into
the same thing, we will look at an offset that is not populated in the
radix tree, and now we're skipping the writeout of dirty extent buffers.
The best fix for this is to not use sectorsize_bits to address nodes,
but that's a larger change. Since this is a fs corruption problem fix
it simply by always using sectors_per_node to increment the start bit.
Fixes: c4aec299fa ("btrfs: introduce submit_eb_subpage() to submit a subpage metadata page")
CC: stable@vger.kernel.org # 5.15+
Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
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>
[ Upstream commit b0c26f4799 ]
There was a bug report about a NULL pointer dereference in
__btrfs_add_free_space_zoned() that ultimately happens because a
conversion from the default metadata profile DUP to a RAID1 profile on two
disks.
The stack trace has the following signature:
BTRFS error (device sdc): zoned: write pointer offset mismatch of zones in raid1 profile
BUG: kernel NULL pointer dereference, address: 0000000000000058
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI
RIP: 0010:__btrfs_add_free_space_zoned.isra.0+0x61/0x1a0
RSP: 0018:ffffa236b6f3f6d0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff96c8132f3400 RCX: 0000000000000001
RDX: 0000000010000000 RSI: 0000000000000000 RDI: ffff96c8132f3410
RBP: 0000000010000000 R08: 0000000000000003 R09: 0000000000000000
R10: 0000000000000000 R11: 00000000ffffffff R12: 0000000000000000
R13: ffff96c758f65a40 R14: 0000000000000001 R15: 000011aac0000000
FS: 00007fdab1cb2900(0000) GS:ffff96e60ca00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000058 CR3: 00000001a05ae000 CR4: 0000000000350ef0
Call Trace:
<TASK>
? __die_body.cold+0x19/0x27
? page_fault_oops+0x15c/0x2f0
? exc_page_fault+0x7e/0x180
? asm_exc_page_fault+0x26/0x30
? __btrfs_add_free_space_zoned.isra.0+0x61/0x1a0
btrfs_add_free_space_async_trimmed+0x34/0x40
btrfs_add_new_free_space+0x107/0x120
btrfs_make_block_group+0x104/0x2b0
btrfs_create_chunk+0x977/0xf20
btrfs_chunk_alloc+0x174/0x510
? srso_return_thunk+0x5/0x5f
btrfs_inc_block_group_ro+0x1b1/0x230
btrfs_relocate_block_group+0x9e/0x410
btrfs_relocate_chunk+0x3f/0x130
btrfs_balance+0x8ac/0x12b0
? srso_return_thunk+0x5/0x5f
? srso_return_thunk+0x5/0x5f
? __kmalloc_cache_noprof+0x14c/0x3e0
btrfs_ioctl+0x2686/0x2a80
? srso_return_thunk+0x5/0x5f
? ioctl_has_perm.constprop.0.isra.0+0xd2/0x120
__x64_sys_ioctl+0x97/0xc0
do_syscall_64+0x82/0x160
? srso_return_thunk+0x5/0x5f
? __memcg_slab_free_hook+0x11a/0x170
? srso_return_thunk+0x5/0x5f
? kmem_cache_free+0x3f0/0x450
? srso_return_thunk+0x5/0x5f
? srso_return_thunk+0x5/0x5f
? syscall_exit_to_user_mode+0x10/0x210
? srso_return_thunk+0x5/0x5f
? do_syscall_64+0x8e/0x160
? sysfs_emit+0xaf/0xc0
? srso_return_thunk+0x5/0x5f
? srso_return_thunk+0x5/0x5f
? seq_read_iter+0x207/0x460
? srso_return_thunk+0x5/0x5f
? vfs_read+0x29c/0x370
? srso_return_thunk+0x5/0x5f
? srso_return_thunk+0x5/0x5f
? syscall_exit_to_user_mode+0x10/0x210
? srso_return_thunk+0x5/0x5f
? do_syscall_64+0x8e/0x160
? srso_return_thunk+0x5/0x5f
? exc_page_fault+0x7e/0x180
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7fdab1e0ca6d
RSP: 002b:00007ffeb2b60c80 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007fdab1e0ca6d
RDX: 00007ffeb2b60d80 RSI: 00000000c4009420 RDI: 0000000000000003
RBP: 00007ffeb2b60cd0 R08: 0000000000000000 R09: 0000000000000013
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffeb2b6343b R14: 00007ffeb2b60d80 R15: 0000000000000001
</TASK>
CR2: 0000000000000058
---[ end trace 0000000000000000 ]---
The 1st line is the most interesting here:
BTRFS error (device sdc): zoned: write pointer offset mismatch of zones in raid1 profile
When a RAID1 block-group is created and a write pointer mismatch between
the disks in the RAID set is detected, btrfs sets the alloc_offset to the
length of the block group marking it as full. Afterwards the code expects
that a balance operation will evacuate the data in this block-group and
repair the problems.
But before this is possible, the new space of this block-group will be
accounted in the free space cache. But in __btrfs_add_free_space_zoned()
it is being checked if it is a initial creation of a block group and if
not a reclaim decision will be made. But the decision if a block-group's
free space accounting is done for an initial creation depends on if the
size of the added free space is the whole length of the block-group and
the allocation offset is 0.
But as btrfs_load_block_group_zone_info() sets the allocation offset to
the zone capacity (i.e. marking the block-group as full) this initial
decision is not met, and the space_info pointer in the 'struct
btrfs_block_group' has not yet been assigned.
Fail creation of the block group and rely on manual user intervention to
re-balance the filesystem.
Afterwards the filesystem can be unmounted, mounted in degraded mode and
the missing device can be removed after a full balance of the filesystem.
Reported-by: 西木野羰基 <yanqiyu01@gmail.com>
Link: https://lore.kernel.org/linux-btrfs/CAB_b4sBhDe3tscz=duVyhc9hNE+gu=B8CrgLO152uMyanR8BEA@mail.gmail.com/
Fixes: b1934cd606 ("btrfs: zoned: handle broken write pointer on zones")
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit bc2dbc4983 ]
[BUG]
When running btrfs/004 with 4K fs block size and 64K page size,
sometimes fsstress workload can take 100% CPU for a while, but not long
enough to trigger a 120s hang warning.
[CAUSE]
When such 100% CPU usage happens, btrfs_punch_hole_lock_range() is
always in the call trace.
One example when this problem happens, the function
btrfs_punch_hole_lock_range() got the following parameters:
lock_start = 4096, lockend = 20469
Then we calculate @page_lockstart by rounding up lock_start to page
boundary, which is 64K (page size is 64K).
For @page_lockend, we round down the value towards page boundary, which
result 0. Then since we need to pass an inclusive end to
filemap_range_has_page(), we subtract 1 from the rounded down value,
resulting in (u64)-1.
In the above case, the range is inside the same page, and we do not even
need to call filemap_range_has_page(), not to mention to call it with
(u64)-1 at the end.
This behavior will cause btrfs_punch_hole_lock_range() to busy loop
waiting for irrelevant range to have its pages dropped.
[FIX]
Calculate @page_lockend by just rounding down @lockend, without
decreasing the value by one. So @page_lockend will no longer overflow.
Then exit early if @page_lockend is no larger than @page_lockstart.
As it means either the range is inside the same page, or the two pages
are adjacent already.
Finally only decrease @page_lockend when calling filemap_range_has_page().
Fixes: 0528476b6a ("btrfs: fix the filemap_range_has_page() call in btrfs_punch_hole_lock_range()")
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: Sasha Levin <sashal@kernel.org>
commit dc08c58696 upstream.
Currently, displaying the btrfs subvol mount option doesn't escape ','.
This makes parsing /proc/self/mounts and /proc/self/mountinfo
ambiguous for subvolume names that contain commas. The text after the
comma could be mistaken for another option (think "subvol=foo,ro", where
ro is actually part of the subvolumes name).
Replace the manual escape characters list with a call to
seq_show_option(). Thanks to Calvin Walton for suggesting this approach.
Fixes: c8d3fe028f ("Btrfs: show subvol= and subvolid= in /proc/mounts")
CC: stable@vger.kernel.org # 5.4+
Suggested-by: Calvin Walton <calvin.walton@kepstin.ca>
Signed-off-by: Johannes Kimmel <kernel@bareminimum.eu>
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 35fec1089e upstream.
If do_zone_finish() is called with a filesystem that has missing devices
(e.g. a RAID file system mounted in degraded mode) it is accessing the
btrfs_device::zone_info pointer, which will not be set if the device
in question is missing.
Check if the device is present (by checking if it has a valid block device
pointer associated) and if not, skip zone finishing for it.
Fixes: 4dcbb8ab31 ("btrfs: zoned: make zone finishing multi stripe capable")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>
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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 2bbc4a45e5 upstream.
If btrfs_zone_activate() is called with a filesystem that has missing
devices (e.g. a RAID file system mounted in degraded mode) it is accessing
the btrfs_device::zone_info pointer, which will not be set if the device in
question is missing.
Check if the device is present (by checking if it has a valid block
device pointer associated) and if not, skip zone activation for it.
Fixes: f9a912a3c4 ("btrfs: zoned: make zone activation multi stripe capable")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>
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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
