The btrfs_abort_transaction() is called at the location where we want to
report the abort. It must be a macro so we get the correct line and
stack trace. This inlines the necessary code and the rest is pushed to
__btrfs_abort_transaction().
There's a possibility to reduce the inlined code if we move the message
to the helper function as well, without loss of information. The
difference is only that the WARN will not print it inside the stack
report but after:
--[ cut here ]--
WARNING: fs/btrfs/transaction.c:2045 at btrfs_commit_transaction+0xa21/0xd30 [btrfs], CPU#11: bonnie++/3377975
...
--[ end trace ] --
BTRFS error (device dm-0 state A): Transaction aborted (error -28)
While previously there would be one more line like:
--[ cut here ]--
BTRFS: Transaction aborted (error -28)
WARNING: fs/btrfs/transaction.c:2045 at btrfs_commit_transaction+0xa21/0xd30 [btrfs], CPU#11: bonnie++/3377975
...
--[ end trace ] --
This removes about 20KiB of btrfs.ko on a release config.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Before btrfs switched to the new mount API in 2023, we were setting
SB_NOSEC in btrfs_mount_root(). This flag tells the VFS that the
filesystem may have files which don't have security xattrs, enabling it
to do some optimizations.
Unfortunately this was missed in the transition, meaning that IS_NOSEC
will always return false for a btrfs inode. This means that
btrfs_direct_write() calls will always get the inode lock exclusively,
meaning that DIO writes to the same file will be serialized.
On my machine, this one-line change results in a ~59% improvement in DIO
throughput:
Before patch:
test: (g=0): rw=randwrite, bs=(R) 4096B-4096B, (W) 4096B-4096B, (T) 4096B-4096B, ioengine=io_uring, iodepth=64
...
fio-3.39
Starting 32 processes
test: Laying out IO file (1 file / 1024MiB)
Jobs: 32 (f=32): [w(32)][100.0%][w=764MiB/s][w=195k IOPS][eta 00m:00s]
test: (groupid=0, jobs=32): err= 0: pid=586: Wed Apr 22 13:03:04 2026
write: IOPS=202k, BW=787MiB/s (826MB/s)(46.1GiB/60012msec); 0 zone resets
bw ( KiB/s): min=498714, max=1199892, per=100.00%, avg=806659.03, stdev=4229.94, samples=3808
iops : min=124677, max=299971, avg=201661.82, stdev=1057.49, samples=3808
cpu : usr=0.32%, sys=1.27%, ctx=8329204, majf=0, minf=1163
IO depths : 1=0.0%, 2=0.0%, 4=0.0%, 8=0.0%, 16=0.0%, 32=0.0%, >=64=100.0%
submit : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
complete : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.1%, >=64=0.0%
issued rwts: total=0,12094328,0,0 short=0,0,0,0 dropped=0,0,0,0
latency : target=0, window=0, percentile=100.00%, depth=64
Run status group 0 (all jobs):
WRITE: bw=787MiB/s (826MB/s), 787MiB/s-787MiB/s (826MB/s-826MB/s), io=46.1GiB (49.5GB), run=60012-60012msec
After patch:
test: (g=0): rw=randwrite, bs=(R) 4096B-4096B, (W) 4096B-4096B, (T) 4096B-4096B, ioengine=io_uring, iodepth=64
...
fio-3.39
Starting 32 processes
test: Laying out IO file (1 file / 1024MiB)
Jobs: 32 (f=32): [w(32)][100.0%][w=1255MiB/s][w=321k IOPS][eta 00m:00s]
test: (groupid=0, jobs=32): err= 0: pid=572: Wed Apr 22 13:13:46 2026
write: IOPS=320k, BW=1250MiB/s (1311MB/s)(73.3GiB/60003msec); 0 zone resets
bw ( MiB/s): min= 619, max= 2289, per=100.00%, avg=1251.28, stdev= 9.64, samples=3808
iops : min=158538, max=586025, avg=320320.80, stdev=2468.97, samples=3808
cpu : usr=0.35%, sys=11.50%, ctx=1584847, majf=0, minf=1160
IO depths : 1=0.0%, 2=0.0%, 4=0.0%, 8=0.0%, 16=0.0%, 32=0.0%, >=64=100.0%
submit : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
complete : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.1%, >=64=0.0%
issued rwts: total=0,19203309,0,0 short=0,0,0,0 dropped=0,0,0,0
latency : target=0, window=0, percentile=100.00%, depth=64
Run status group 0 (all jobs):
WRITE: bw=1250MiB/s (1311MB/s), 1250MiB/s-1250MiB/s (1311MB/s-1311MB/s), io=73.3GiB (78.7GB), run=60003-60003msec
The script to reproduce that:
#!/bin/bash
mkfs.btrfs -f /dev/nvme0n1
mount /dev/nvme0n1 /mnt/test
mkdir /mnt/test/nocow
chattr +C /mnt/test/nocow
fio /root/test.fio
# cat /root/test.fio
[global]
rw=randwrite
ioengine=io_uring
iodepth=64
size=1g
direct=1
startdelay=20
force_async=4
ramp_time=5
runtime=60
group_reporting=1
numjobs=32
time_based
disk_util=0
clat_percentiles=0
disable_lat=1
disable_clat=1
disable_slat=1
filename=/mnt/test/nocow/fiofile
[test]
name=test
bs=4k
stonewall
This was on a VM with 8 cores and 8GB of RAM, with a real NVMe exposed
through PCI passthrough. The figures for XFS and ext4 in comparison are
both about ~3GB/s.
Fixes: ad21f15b0f ("btrfs: switch to the new mount API")
Signed-off-by: Mark Harmstone <mark@harmstone.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This feature was introduced in v6.17 under experimental, and we had
several small bugs related to or exposed by that:
e9e3b22ddf ("btrfs: fix beyond-EOF write handling")
18de34daa7 ("btrfs: truncate ordered extent when skipping writeback past i_size")
Otherwise, the feature has been frequently tested by btrfs developers.
The latest fix only arrived in v6.19. After three releases, I think it's
time to move this feature out of experimental.
And since we're here, also remove the comment about the bitmap size
limit, which is no longer relevant in the context. It will soon be
outdated for the incoming huge folio support.
Reviewed-by: Neal Gompa <neal@gompa.dev>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The function add_ra_bio_folios() has been utilizing folio interfaces
since c808c1dcb1 ("btrfs: convert add_ra_bio_pages() to use only
folios"), but we are still referring to "pages" inside the function name
and all comments.
Furthermore, such folio/page mixing can even be confusing, e.g. the
variable @page_end is very confusing as we're not really referring to
the end of the page, but the end of the folio, especially when we
already have large folio support.
Enhance that function by:
- Rename "page" to "folio" to avoid confusion
- Skip to the folio end if there is already a folio in the page cache
The existing skip is:
cur += folio_size(folio);
This is incorrect if @cur is not folio size aligned, and can be
common with large folio support.
Thankfully this is not going to cause any real bugs, but at most will
skip some blocks that can be added to readahead.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[BACKGROUND]
When bs < ps support was initially introduced, the compressed data
readahead was disabled as at that time the target page size was 64K.
This means a compressed data extent can span at most 3 64K pages (the
head and tail parts are not aligned to 64K), meaning the benefit is
pretty minimal.
[UNEXPECTED WORKING SITUATION]
But with the already merged large folio support, we're already enabling
readahead with subpage routine unintentionally, e.g.:
0 4K 8K 12K 16K
| Folio 0 | Folio 8K |
|<----- Compressed data ------->|
We have 2 8K sized folios, all backed by a single compressed data.
In that case add_ra_bio_pages() will continue to add folio 8K into the
read bio, as the condition to skip is only (bs < ps), not taking the
newer large folio support into consideration at all.
So for folio 8K, it is added to the read bio, but without subpage lock
bitmap populated.
Then at end_bbio_data_read(), folio 0 has proper locked bitmap set, but
folio 8K does not.
This inconsistency is handled by the extra safety net at
btrfs_subpage_end_and_test_lock() where if a folio has no @nr_locked, it
will just be unlocked without touching the locked bitmap.
[ENHANCEMENT]
Make add_ra_bio_pages() support bs < ps and large folio cases, by
removing the check and calling btrfs_folio_set_lock() unconditionally.
This won't make any difference on 4K page sized systems with large
folios, as the readahead is already working, although unexpectedly.
But this will enable true compressed data readahead for bs < ps cases
properly.
Please note that such readahead will only work if the compressed extent is
crossing folio boundaries, which is also the existing limitation.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Commit 0b2600f81c ("treewide: change inode->i_ino from unsigned long
to u64") sets the inode number type to u64 unconditionally, so we can
use it directly as there's no difference on 32bit and 64bit platform. We
used to have a copy of the number in our btrfs_inode.
The size of btrfs_inode on 32bit platform is about 688 bytes (after the
change).
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently btrfs_writepages() just accumulates as large bio as possible
(within writeback_control constraints) and then submits it. This can
however lead to significant latency in writeback IO submission (I have
observed tens of milliseconds) because the submitted bio easily has over
hundred of megabytes. Consequently this leads to IO pipeline stalls and
reduced throughput.
At the same time beyond certain size submitting so large bio provides
diminishing returns because the bio is split by the block layer
immediately anyway. So compute (estimate of) bio size beyond which we
are unlikely to improve performance and just submit the bio for
writeback once we accumulate that much to keep the IO pipeline busy.
This improves writeback throughput for sequential writes by about 15% on
the test machine I was using.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Jan Kara <jack@suse.cz>
[ Fix the handling of missing device to avoid NULL pointer dereference. ]
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Originally 2K block size support was introduced to test subpage (block
size < page size) on x86_64 where the page size is exactly the original
minimal block size.
However that 2K block size support has some problems:
- No 2K nodesize support
This is critical, as there is still no way to exercise the subpage
metadata routine.
- Very easy to test subpage data path now
With the currently experimental large folio support, it's very easy to
test the subpage data folio path already, as when a folio larger than
4K is encountered on x86_64, we will need all the subpage folio states
and bitmaps.
So there is no need to use 2K block size just to verify subpage data
path even on x86_64.
And with the incoming huge folio (2M on x86_64) support, the 2K block
size will easily double the bitmap size, considering the burden to
maintain and the limited extra coverage, I believe it's time to remove
it for the incoming huge folio support.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The function always returns true or false but the its return type is
defined as int, which makes no sense. Change it to bool.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.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>
If statement branches that lead to a DEBUG_WARN() are unexpected to happen
and in most places we surround their expressions with the unlikely tag,
however a few places are missing. Add the unlikely tag to those missing
places to make it explicit to a reader that it's not expected and to hint
the compiler to generate better code.
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>
The 'disk_cache_state' and 'cached' fields are defined with an int type
but all the values we assigned to them come from the enums
btrfs_disk_cache_state and btrfs_caching_type. So change the type in the
btrfs_block_group structure from int to these enums - in practice an enum
is an int, so this is more for readability and clarity.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Sun YangKai <sunk67188@gmail.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There's no need to calculate again the size for the temporary block
reserve in btrfs_replace_file_extents() - we have already calculated it
and stored it in the 'min_size' variable.
So use the variable to make it more clear and also make the variable const
since it's not supposed to change during the whole function.
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>
[BUG]
Running btrfs balance can trigger a null-ptr-deref before relocating a
data chunk when metadata corruption leaves a chunk in the chunk tree
without a corresponding block group in the in-memory cache:
KASAN: null-ptr-deref in range [0x0000000000000088-0x000000000000008f]
RIP: 0010:btrfs_may_alloc_data_chunk+0x40/0x1c0 fs/btrfs/volumes.c:3601
Call Trace:
__btrfs_balance fs/btrfs/volumes.c:4217 [inline]
btrfs_balance+0x2516/0x42b0 fs/btrfs/volumes.c:4604
btrfs_ioctl_balance fs/btrfs/ioctl.c:3577 [inline]
btrfs_ioctl+0x25cf/0x5b90 fs/btrfs/ioctl.c:5313
...
[CAUSE]
__btrfs_balance() iterates the on-disk chunk tree and passes the chunk
logical bytenr to btrfs_may_alloc_data_chunk() before relocating a data
chunk. That helper then queries the in-memory block group cache:
cache = btrfs_lookup_block_group(fs_info, chunk_offset);
chunk_type = cache->flags; /* cache may be NULL */
A corrupt image can contain a chunk item whose matching block group
item is missing, so no block group is ever inserted into the cache. In
that case btrfs_lookup_block_group() returns NULL.
The code only guards this with ASSERT(cache), which becomes a no-op when
CONFIG_BTRFS_ASSERT is disabled. The subsequent dereference of
cache->flags therefore crashes the kernel.
[FIX]
Add a NULL check after btrfs_lookup_block_group() in
btrfs_may_alloc_data_chunk() and print and error message for clarity.
Signed-off-by: ZhengYuan Huang <gality369@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[BUG]
Running btrfs balance with a usage range filter (-dusage=min..max) can
trigger a null-ptr-deref when metadata corruption causes a chunk to have
no corresponding block group in the in-memory cache:
KASAN: null-ptr-deref in range [0x0000000000000070-0x0000000000000077]
RIP: 0010:chunk_usage_range_filter fs/btrfs/volumes.c:3845 [inline]
RIP: 0010:should_balance_chunk fs/btrfs/volumes.c:4031 [inline]
RIP: 0010:__btrfs_balance fs/btrfs/volumes.c:4182 [inline]
RIP: 0010:btrfs_balance+0x249e/0x4320 fs/btrfs/volumes.c:4618
...
Call Trace:
btrfs_ioctl_balance fs/btrfs/ioctl.c:3577 [inline]
btrfs_ioctl+0x25cf/0x5b90 fs/btrfs/ioctl.c:5313
vfs_ioctl fs/ioctl.c:51 [inline]
...
The bug is reproducible on recent development branch.
[CAUSE]
Two separate data structures are involved:
1. The on-disk chunk tree, which records every chunk (logical address
space region) and is iterated by __btrfs_balance().
2. The in-memory block group cache (fs_info->block_group_cache_tree),
which is built at mount time by btrfs_read_block_groups() and holds
a struct btrfs_block_group for each chunk. This cache is what the
usage range filter queries.
On a well-formed filesystem, these two are kept in 1:1 correspondence.
However, btrfs_read_block_groups() builds the cache from block group
items in the extent tree, not directly from the chunk tree. A corrupted
image can therefore contain a chunk item in the chunk tree whose
corresponding block group item is absent from the extent tree; that
chunk's block group is then never inserted into the in-memory cache.
When balance iterates the chunk tree and reaches such an orphaned chunk,
should_balance_chunk() calls chunk_usage_range_filter(), which queries
the block group cache:
cache = btrfs_lookup_block_group(fs_info, chunk_offset);
chunk_used = cache->used; /* cache may be NULL */
btrfs_lookup_block_group() returns NULL silently when no cached entry
covers chunk_offset. chunk_usage_range_filter() does not check the return
value, so the immediately following dereference of cache->used triggers
the crash.
[FIX]
Add a NULL check after btrfs_lookup_block_group() in
chunk_usage_range_filter(). When the lookup fails, emit a btrfs_err()
message identifying the affected bytenr and return -EUCLEAN to indicate
filesystem corruption.
Since chunk_usage_range_filter() now has an error path, change its
return type from bool to error pointer, return 0 if the chunk matches
the usage range, and 1 if it should be filtered out.
Signed-off-by: ZhengYuan Huang <gality369@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[BUG]
Running btrfs balance with a usage filter (-dusage=N) can trigger a
null-ptr-deref when metadata corruption causes a chunk to have no
corresponding block group in the in-memory cache:
KASAN: null-ptr-deref in range [0x0000000000000070-0x0000000000000077]
RIP: 0010:chunk_usage_filter fs/btrfs/volumes.c:3874 [inline]
RIP: 0010:should_balance_chunk fs/btrfs/volumes.c:4018 [inline]
RIP: 0010:__btrfs_balance fs/btrfs/volumes.c:4172 [inline]
RIP: 0010:btrfs_balance+0x2024/0x42b0 fs/btrfs/volumes.c:4604
...
Call Trace:
btrfs_ioctl_balance fs/btrfs/ioctl.c:3577 [inline]
btrfs_ioctl+0x25cf/0x5b90 fs/btrfs/ioctl.c:5313
vfs_ioctl fs/ioctl.c:51 [inline]
...
The bug is reproducible on current development branch.
[CAUSE]
Two separate data structures are involved:
1. The on-disk chunk tree, which records every chunk (logical address
space region) and is iterated by __btrfs_balance().
2. The in-memory block group cache (fs_info->block_group_cache_tree),
which is built at mount time by btrfs_read_block_groups() and holds
a struct btrfs_block_group for each chunk. This cache is what the
usage filter queries.
On a well-formed filesystem, these two are kept in 1:1 correspondence.
However, btrfs_read_block_groups() builds the cache from block group
items in the extent tree, not directly from the chunk tree. A corrupted
image can therefore contain a chunk item in the chunk tree whose
corresponding block group item is absent from the extent tree; that
chunk's block group is then never inserted into the in-memory cache.
When balance iterates the chunk tree and reaches such an orphaned chunk,
should_balance_chunk() calls chunk_usage_filter(), which queries the block
group cache:
cache = btrfs_lookup_block_group(fs_info, chunk_offset);
chunk_used = cache->used; /* cache may be NULL */
btrfs_lookup_block_group() returns NULL silently when no cached entry
covers chunk_offset. chunk_usage_filter() does not check the return value,
so the immediately following dereference of cache->used triggers the crash.
[FIX]
Add a NULL check after btrfs_lookup_block_group() in chunk_usage_filter().
When the lookup fails, emit a btrfs_err() message identifying the
affected bytenr and return -EUCLEAN to indicate filesystem corruption.
Since chunk_usage_filter() now has an error path, change its return type
from bool to error pointer and 0 if the chunk passes the usage filter,
and 1 if it should be skipped.
Update should_balance_chunk() accordingly to propagate negative errors
from the usage filter.
Signed-off-by: ZhengYuan Huang <gality369@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Add a new unprivileged BTRFS_IOC_GET_CSUMS ioctl, which can be used to
query the on-disk csums for a file range.
The ioctl is deliberately per-file rather than exposing raw csum tree
lookups, to avoid leaking information to users about files they may not
have access to.
This is done by userspace passing a struct btrfs_ioctl_get_csums_args to
the kernel, which details the offset and length we're interested in, and
a buffer for the kernel to write its results into. The kernel writes a
struct btrfs_ioctl_get_csums_entry into the buffer, followed by the
csums if available. The maximum size of the user buffer is capped to
16MiB.
If the extent is an uncompressed, non-NODATASUM extent, the kernel sets
the entry type to BTRFS_GET_CSUMS_HAS_CSUMS and follows it with the
csums. If it is sparse, preallocated, or beyond the EOF, it sets the
type to BTRFS_GET_CSUMS_ZEROED - this is so userspace knows it can use
the precomputed hash of the zero sector. Otherwise, it sets the type to
BTRFS_GET_CSUMS_NODATASUM, BTRFS_GET_CSUMS_COMPRESSED,
BTRFS_GET_CSUM_ENCRYPTED, or BTRFS_GET_CSUM_INLINE.
For example, a file with a [0, 4K) hole and [4K, 12K) data extent would
produce the following output buffer:
| [0, 4K) ZEROED | [4K, 12K) HAS_CSUMS | csum data |
We do store the csums of compressed extents, but we deliberately don't
return them here: they're calculated over the compressed data, not the
uncompressed data that's returned to userspace. Similarly for encrypted
data, once encryption is supported, in which the csums will be on the
ciphertext.
The main use case for this is for speeding up mkfs.btrfs --rootdir. For
the case when the source FS is btrfs and using the same csum algorithm,
we can avoid having to recalculate the csums - in my synthetic
benchmarks (16GB file on a spinning-rust drive), this resulted in a ~11%
speed-up (218s to 196s).
When using the --reflink option added in btrfs-progs v6.16.1, we can forgo
reading the data entirely, resulting a ~2200% speed-up on the same test
(128s to 6s).
# mkdir rootdir
# dd if=/dev/urandom of=rootdir/file bs=4096 count=4194304
(without ioctl)
# echo 3 > /proc/sys/vm/drop_caches
# time mkfs.btrfs --rootdir rootdir testimg
...
real 3m37.965s
user 0m5.496s
sys 0m6.125s
# echo 3 > /proc/sys/vm/drop_caches
# time mkfs.btrfs --rootdir rootdir --reflink testimg
...
real 2m8.342s
user 0m5.472s
sys 0m1.667s
(with ioctl)
# echo 3 > /proc/sys/vm/drop_caches
# time mkfs.btrfs --rootdir rootdir testimg
...
real 3m15.865s
user 0m4.258s
sys 0m6.261s
# echo 3 > /proc/sys/vm/drop_caches
# time mkfs.btrfs --rootdir rootdir --reflink testimg
...
real 0m5.847s
user 0m2.899s
sys 0m0.097s
Another notable use case is for deduplication, where reading the
checksums may serve as a hint instead of reading the whole file data.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Mark Harmstone <mark@harmstone.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[WARNING]
When running test cases with injected errors or shutdown, e.g.
generic/388 or generic/475, there is a chance that the following kernel
warning is triggered:
BTRFS info (device dm-2): first mount of filesystem d8a19a28-3232-4809-b0df-38df83e71bff
BTRFS info (device dm-2): using crc32c checksum algorithm
BTRFS info (device dm-2): checking UUID tree
BTRFS info (device dm-2): turning on async discard
BTRFS info (device dm-2): enabling free space tree
BTRFS critical (device dm-2 state E): emergency shutdown
------------[ cut here ]------------
WARNING: extent_io.c:1742 at extent_writepage_io+0x437/0x520 [btrfs], CPU#2: kworker/u43:2/651591
CPU: 2 UID: 0 PID: 651591 Comm: kworker/u43:2 Tainted: G W OE 7.0.0-rc6-custom+ #365 PREEMPT(full) 5804053f02137e627472d94b5128cc9fcb110e88
RIP: 0010:extent_writepage_io+0x437/0x520 [btrfs]
Call Trace:
<TASK>
extent_write_cache_pages+0x2a5/0x820 [btrfs 70299925d0856939e93b17d480651713b3cbba58]
btrfs_writepages+0x74/0x130 [btrfs 70299925d0856939e93b17d480651713b3cbba58]
do_writepages+0xd0/0x160
__writeback_single_inode+0x42/0x340
writeback_sb_inodes+0x22d/0x580
wb_writeback+0xc6/0x360
wb_workfn+0xbd/0x470
process_one_work+0x198/0x3b0
worker_thread+0x1c8/0x330
kthread+0xee/0x120
ret_from_fork+0x2a6/0x330
ret_from_fork_asm+0x11/0x20
</TASK>
---[ end trace 0000000000000000 ]---
BTRFS error (device dm-2 state E): root 5 ino 259 folio 1323008 is marked dirty without notifying the fs
BTRFS error (device dm-2 state E): failed to submit blocks, root=5 inode=259 folio=1323008 submit_bitmap=0: -117
BTRFS info (device dm-2 state E): last unmount of filesystem d8a19a28-3232-4809-b0df-38df83e71bff
[CAUSE]
Inside btrfs we have the following pattern in several locations, for
example inside btrfs_dirty_folio():
btrfs_clear_extent_bit(&inode->io_tree, start_pos, end_of_last_block,
EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
cached);
ret = btrfs_set_extent_delalloc(inode, start_pos, end_of_last_block,
extra_bits, cached);
if (ret)
return ret;
However btrfs_set_extent_delalloc() can return IO errors other than -ENOMEM
through the following callchain:
btrfs_set_extent_delalloc()
\- btrfs_find_new_delalloc_bytes()
\- btrfs_get_extent()
\- btrfs_lookup_file_extent()
\- btrfs_search_slot()
When such IO error happened, the previous btrfs_clear_extent_bit() has
cleared the EXTENT_DELALLOC for the range, and we're expecting
btrfs_set_extent_delalloc() to re-set EXTENT_DELALLOC.
But since btrfs_set_extent_delalloc() failed before
btrfs_set_extent_bit(), EXTENT_DELALLOC flag is no longer present.
And if the folio range is dirty before entering
btrfs_set_extent_delalloc(), we got a dirty folio but no EXTENT_DELALLOC
flag now.
Then we hit the folio writeback:
extent_writepage()
|- writepage_delalloc()
| No ordered extent is created, as there is no EXTENT_DELALLOC set
| for the folio range.
| This also means the folio has no ordered flag set.
|
|- extent_writepage_io()
\- if (unlikely(!folio_test_ordered(folio))
Now we hit the warning.
[FIX]
Introduce a new helper, btrfs_reset_extent_delalloc() to replace the
currently open-coded btrfs_clear_extent_bit() +
btrfs_set_extent_delalloc() combination.
Instead of calling btrfs_clear_extent_bit() first, update
EXTENT_DELALLOC_NEW first, as that part can fail due to metadata IO,
meanwhile btrfs_clear_extent_bit() and btrfs_set_extent_bit() won't
return any error but retry memory allocation until succeeded.
This allows us to fail early without clearing EXTENT_DELALLOC bit, so
even if that new btrfs_reset_extent_delalloc() failed before touching
EXTENT_DELALLOC, the existing dirty range will still have their old
EXTENT_DELALLOC flag present, thus avoid the warning.
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There is no need to pass the free space control structure as an argument
because we can grab it from the given block group.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We can get the free space control structure from the given block group,
so there is no need to pass it as an argument.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
It's not necessary since we can get the block group from the given
free space control structure.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The op field always points to the same use_bitmap function, the only
exception is during self tests where we make it temporarily point to a
different function. So just because of this op pointer field we are
increasing the structure size by 8 bytes.
Instead of storing a pointer to a use_bitmap function in struct
btrfs_free_space_ctl, move the pointer to struct btrfs_info, make
insert_into_bitmap() use that pointer if we are running the self tests
and initialize that pointer to the current, default use_bitmap function
(now exported for the tests as btrfs_use_bitmap). This way we reduce
the size of struct btrfs_free_space_ctl from 136 to 128 bytes and can
now fit 32 structures in a 4K page instead of 30. This also avoids the
cost of the indirection of a function pointer call when we are not
running the self tests.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We have a 4 bytes hole in the structure, reorder some fields so that we
eliminate the hole and reduce the structure size from 144 bytes down to
136 bytes. This way on a 4K page system, we can fit 30 structures per
page instead of 28.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The unit field always has a value matching the sector size, and since we
have a block group pointer in the structure, we can access the block group
and then its fs_info field to get to the sector size. So remove the field,
which will allow us later to shrink the structure size.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There's no need for the start field, we can take it from the block group.
This reduces the structure size from 152 bytes down to 144 bytes, so on
a 4K page system we can now fit 28 structures instead of 26.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We are currently allocating the free space control structures for block
groups using the generic slabs, and given that the size of the
btrfs_free_space_ctl structure is 152 bytes (on a release kernel), we end
up using the kmalloc-192 slab and therefore waste quite some memory since
on a 4K page system we can only fit 21 free space control structures per
page. These structures are allocated and delallocated every time we create
and remove block groups.
So use a kmem_cache for free space control structures, this way on a 4K
page system we can fit 26 structures instead of 21.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We are currently allocating block groups using the generic slabs, and
given that the size of btrfs_block_group structure is 672 bytes (on a
release kernel), we end up using the kmalloc-1024 slab and therefore
waste quite some memory since on a 4K page system we can only fit 4
block groups per page. The block groups are also allocated and
delallocated with some frequency, specially if we have auto reclaim
enabled.
So use a kmem_cache for block groups, this way on a 4K page system we
can fit 6 block groups per page instead of 4.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We have support for optional string to be printed in ASSERT() (added in
19468a623a ("btrfs: enhance ASSERT() to take optional format
string")), it's not yet everywhere it could be so add a few more files.
Try to finish what was left after 1c094e6cce ("btrfs: make a few
more ASSERTs verbose").
Signed-off-by: David Sterba <dsterba@suse.com>
Many ioctl handlers are suitable for the AUTO_KFREE conversions as the
data are temporary and short lived. The conversions are trivial or the
collateral changes are straightforward.
A kfree() preceding mnt_drop_write_file() is slightly more efficient but
in the reverse order (i.e. the automatic kfree) does not cause any
significant change as the write drop does only a few simple operations.
Note: __free() handles also error pointers, so this is safe for the
memdup_user() errors too.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There's one use of kmalloc_array() that can be transformed to
kmalloc_objs() in the same way as suggested in commit 69050f8d6d
("treewide: Replace kmalloc with kmalloc_obj for non-scalar types"),
swap the arguments and drop GFP flags. All the other cases of
kmalloc_array() do not use a simple type so this is the only one.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Do a few more (trivial) conversions that started in commit 69050f8d6d
("treewide: Replace kmalloc with kmalloc_obj for non-scalar types").
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There are only two possible types of the delayed ref action, this can be
verified at the beginning for the whole function and not just one block.
Replace the assertion with a debugging warning just in case.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
For a simple if + WARN_ON we should use the condition directly in the
macro.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The folio checked flag is only utilized by the COW fixup mechanism
inside btrfs.
Since the COW fixup is already removed from non-experimental builds,
there is no need to keep the checked subpage bitmap.
This will saves us some space for large folios, for example for a single
256K sized large folio on 4K page sized systems:
Old bitmap size = 6 * (256K / 4K / 8) = 48 bytes
New bitmap size = 5 * (256K / 4K / 8) = 40 bytes
This will be more obvious when we're going to support huge folios (order
= 9).
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[BACKGROUND]
Btrfs has a special mechanism called COW fixup, which detects dirty
pages without an ordered extent (folio ordered flag).
Normally a dirty folio must go through delayed allocation (delalloc)
before it can be submitted, and delalloc will create an ordered extent
for it and mark the range with ordered flag.
However in older kernels, there are bugs related to get_user_pages()
which can lead to some page marked dirty but without notifying the fs to
properly prepare them for writeback.
In that case without an ordered extent btrfs is unable to properly
submit such dirty folios, thus the COW fixup mechanism is introduced,
which do the extra space reservation so that they can be written back
properly.
[MODERN SOLUTIONS]
The MM layer has solved it properly now with the introduction of
pin_user_pages*(), so we're handling cases that are no longer valid.
So commit 7ca3e84980 ("btrfs: reject out-of-band dirty folios during
writeback") is introduced to change the behavior from going through
COW fixup to rejecting them directly for experimental builds.
So far it works fine, but when errors are injected into the IO path, we
have random failures triggering the new warnings.
It looks like we have error path that cleared the ordered flag but
leaves the folio dirty flag, which later triggers the warning.
[REMOVAL OF COW FIXUP]
Although I hope to fix all those known warnings cases, I just can not
figure out the root cause yet.
But on the other hand, if we remove the ordered and checked flags in the
future, and purely rely on the dirty flags and ordered extent search, we
can get a much cleaner handling.
Considering it's no longer hitting the COW fixup for normal IO paths, I
think it's finally the time to remove the COW fixup completely.
Furthermore, the function name "btrfs_writepage_cow_fixup()" is no
longer meaningful, and since it's pretty small, only a folio flag check
with error message, there is no need to put it as a dedicated helper,
just open code it inside extent_writepage_io().
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Commit 6e181cfe2409 ("btrfs: revalidate cached tree blocks on the
uptodate path") introduced the @check parameter for
btrfs_buffer_uptodate() to allow re-validation of a cached extent
buffer.
But there are still call sites that don't utilize this parameter, which
exposes them to possible corrupted tree blocks, e.g. an empty child leaf
of a parent node, which should be rejected by btrfs_verify_level_key()
but if @check is NULL such check will be skipped and cause problems.
Thankfully for a lot of cases there is already an existing @check
structure around and we can pass it directly to btrfs_buffer_uptodate().
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Pull x86 fixes from Ingo Molnar:
- Add more AMD Zen6 models (Pratik Vishwakarma)
- Avoid confusing bootup message by the Intel resctl enumeration
code when running on certain AMD systems (Tony Luck)
* tag 'x86-urgent-2026-06-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/resctrl: Only check Intel systems for SNC
x86/CPU/AMD: Add more Zen6 models
Pull timer fixes from Ingo Molnar:
- Fix the arch_inlined_clockevent_set_next_coupled() prototype in the
!CONFIG_GENERIC_CLOCKEVENTS_MIN_ADJUST case (Naveen Kumar Chaudhary)
- Fix an off-by-1 bug in the sys_settimeofday() usecs validation code
(Naveen Kumar Chaudhary)
- Mark vdso_k_*_data pointers as __ro_after_init (Thomas Weißschuh)
- Fix livelock race in tmigr_handle_remote_up() (Amit Matityahu)
* tag 'timers-urgent-2026-06-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
timers/migration: Fix livelock in tmigr_handle_remote_up()
vdso/datastore: Mark vdso_k_*_data pointers as __ro_after_init
time: Fix off-by-one in settimeofday() usec validation
clockevents: Fix duplicate type specifier in stub function parameter
Pull rseq fix from Ingo Molnar:
- Fix uninitialized stack variable in rseq_exit_user_update() (Qing
Wang)
* tag 'sched-urgent-2026-06-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
rseq: Fix using an uninitialized stack variable in rseq_exit_user_update()
Pull locking fixes from Ingo Molnar:
- Fix a NULL pointer dereference bug in the FUTEX_CMP_REQUEUE_PI
code (Ji'an Zhou)
- Fix a NULL pointer dereference bug in the rtmutex code (Davidlohr
Bueso)
* tag 'locking-urgent-2026-06-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
locking/rtmutex: Skip remove_waiter() when waiter is not enqueued
futex/requeue: Prevent NULL pointer dereference in remove_waiter() on self-deadlock
Pull regulator fix from Mark Brown:
"Arnd's randconfig testing turned up a missing selection of
CONFIG_IRQ_DOMAIN which was causing build breaks"
* tag 'regulator-fix-v7.1-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator:
regulator: mt6363: select CONFIG_IRQ_DOMAIN
Pull input fixes from Dmitry Torokhov:
- two quirks for atkbd to deal with laptops that can not handle
"deactivate" command on the keyboard PS/2 port
* tag 'input-for-v7.1-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
Input: atkbd - skip deactivate for HONOR BCC-N's internal keyboard
Input: atkbd - add DMI quirk for Lenovo Yoga Air 14 (83QK)
After commit 0652a3daa7 ("tracing: Fix CFI violation in probestub
being called by tprobes"), there are many build errors when building
ARCH=arm multi_v7_defconfig + CONFIG_CFI=y like:
In file included from drivers/base/devres.c:17:
In file included from drivers/base/trace.h:16:
In file included from include/linux/tracepoint.h:23:
include/linux/cfi.h:44:6: error: call to undeclared function 'get_kernel_nofault'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
44 | if (get_kernel_nofault(hash, func - cfi_get_offset()))
| ^
1 error generated.
get_kernel_nofault() is called in the generic version of
cfi_get_func_hash() but nothing ensures uaccess.h is always included for
a proper expansion and prototype. Include uaccess.h in cfi.h to clear
up the errors.
Cc: stable@vger.kernel.org
Fixes: 0652a3daa7 ("tracing: Fix CFI violation in probestub being called by tprobes")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull sound fixes from Takashi Iwai:
"It's getting calmer, but we still came up with a handful of small
fixes, including two core fixes. All look sane and safe.
Core:
- Fix wait queue list corruption in snd_pcm_drain() on linked streams
- Fix UMP event stack overread in seq dummy driver
USB-audio:
- Add quirk for AB13X USB Audio
- Fix the regression with sticky mixer volumes in 7.1-rc
ASoC:
- Fix 32-slot TDM breakage on Freescale SAI
- Varioud DMI quirks for AMD ACP"
* tag 'sound-7.1-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
ALSA: seq: dummy: fix UMP event stack overread
ALSA: usb-audio: Add iface reset and delay quirk for AB13X USB Audio
ALSA: PCM: Fix wait queue list corruption in snd_pcm_drain() on linked streams
ASoC: amd: acp70: add standalone RT721 SoundWire machine
ASoC: amd: yc: Add MSI Raider A18 HX A9WJG to quirk table
ASoC: fsl_sai: Fix 32 slots TDM broken by integer shift UB in xMR write
ASoC: amd: yc: Enable internal mic on MSI Bravo 17 C7VF
ASoC: amd: acp: Add DMI quirk for Lenovo Yoga Pro 7 15ASH11
ALSA: usb-audio: Set the value of potential sticky mixers to maximum
Pull Rust fixes from Miguel Ojeda:
"Toolchain and infrastructure:
- Fix 'rustc-option' (the Makefile one) when cross-compiling that
leads to build or boot failures in certain configs
- Work around a Rust compiler bug (already fixed for Rust 1.98.0)
thats lead to boot failures in certain configs due to missing
'uwtable' LLVM module flags
- Support a Rust compiler change (starting with Rust 1.98.0) in the
unstable target specification JSON files
- Forbid Rust + arm + KASAN configs, which do not build
'kernel' crate:
- Fix NOMMU build by adding a missing helper"
* tag 'rust-fixes-7.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux:
rust: x86: support Rust >= 1.98.0 target spec
rust: arm64: set uwtable llvm module flag for CONFIG_UNWIND_TABLES
rust: helpers: add is_vmalloc_addr wrapper for NOMMU builds
rust: kasan/kbuild: fix rustc-option when cross-compiling
ARM: Do not select HAVE_RUST when KASAN is enabled
Pull vfs fixes from Christian Brauner:
- Fix error handling in ovl_cache_get()
- Tighten access checks for exited tasks in pidfd_getfd()
- Fix selftests leak in __wait_for_test()
- Limit FUSE_NOTIFY_RETRIEVE to uptodate folios
- Reject fuse_notify() pagecache ops on directories
- Clear JOBCTL_PENDING_MASK for caller in zap_other_threads()
- Fix failure to unlock in nfsd4_create_file()
- Fix pointer arithmetic in qnx6 directory iteration
- Fix UAF due to unlocked ->mnt_ns read in may_decode_fh()
- Avoid potential null folio->mapping deref during iomap error
reporting
* tag 'vfs-7.1-rc7.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
iomap: avoid potential null folio->mapping deref during error reporting
fhandle: fix UAF due to unlocked ->mnt_ns read in may_decode_fh()
fs/qnx6: fix pointer arithmetic in directory iteration
VFS: fix possible failure to unlock in nfsd4_create_file()
signal: clear JOBCTL_PENDING_MASK for caller in zap_other_threads()
fuse: reject fuse_notify() pagecache ops on directories
fuse: limit FUSE_NOTIFY_RETRIEVE to uptodate folios
selftests: harness: fix pidfd leak in __wait_for_test
pidfd: refuse access to tasks that have started exiting harder
ovl: keep err zero after successful ovl_cache_get()
David Sterba
Mark Harmstone
Qu Wenruo
Jan Kara
Filipe Manana
Thorsten Blum
ZhengYuan Huang
Linus Torvalds
Nathan Chancellor
Cryolitia PukNgae