kernel/linux.git/include/uapi/linux/btrfs.h, branch v6.19.11

btrfs: implement shutdown ioctl

2025-11-24T20:56:17+00:00

The shutdown ioctl should follow the XFS one, which use magic number 'X', and ioctl number 125, with a uint32 as flags. For now btrfs don't distinguish DEFAULT and LOGFLUSH flags (just like f2fs), both will freeze the fs first (implies committing the current transaction), setting the SHUTDOWN flag and finally thaw the fs. For NOLOGFLUSH flag, the freeze/thaw part is skipped thus the current transaction is aborted. The new shutdown ioctl is hidden behind experimental features for more testing. Reviewed-by: Johannes Thumshirn Reviewed-by: Anand Jain Tested-by: Anand Jain Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: defrag: add flag to force no-compression

2025-07-21T23:13:03+00:00

Currently the defrag ioctl cannot rewrite the extents without compression. Add a new flag for that, as setting compression to 0 (or "no compression") means to do no changes to compression so take what is the current default, like mount options or properties. The defrag setting overrides mount or properties. The compression BTRFS_DEFRAG_DONT_COMPRESS is only used for in-memory operations and does not need to have a fixed value. Mount with zstd:9, copy test file from /usr/bin/ (about 260KB): $ mount -o compress=zstd:9 /dev/vda /mnt $ filefrag -vsb testfile filefrag: -b needs a blocksize option, assuming 1024-byte blocks. Filesystem type is: 9123683e File size of testfile is 297704 (292 blocks of 1024 bytes) ext: logical_offset: physical_offset: length: expected: flags: 0: 0.. 127: 13312.. 13439: 128: encoded 1: 128.. 255: 13364.. 13491: 128: 13440: encoded 2: 256.. 291: 13424.. 13459: 36: 13492: last,encoded,eof testfile: 3 extents found $ compsize testfile Processed 1 file, 3 regular extents (3 refs), 0 inline, 1 fragments. Type Perc Disk Usage Uncompressed Referenced TOTAL 42% 124K 292K 292K zstd 42% 124K 292K 292K Defrag to uncompressed: $ btrfs fi defrag --nocomp testfile $ filefrag -vsb testfile filefrag: -b needs a blocksize option, assuming 1024-byte blocks. Filesystem type is: 9123683e File size of testfile is 297704 (292 blocks of 1024 bytes) ext: logical_offset: physical_offset: length: expected: flags: 0: 0.. 291: 291840.. 292131: 292: last,eof testfile: 1 extent found $ compsize testfile Processed 1 file, 1 regular extents (1 refs), 0 inline, 1 fragments. Type Perc Disk Usage Uncompressed Referenced TOTAL 100% 292K 292K 292K none 100% 292K 292K 292K Compress again with LZO: $ btrfs fi defrag -clzo testfile $ filefrag -vsb testfile filefrag: -b needs a blocksize option, assuming 1024-byte blocks. Filesystem type is: 9123683e File size of testfile is 297704 (292 blocks of 1024 bytes) ext: logical_offset: physical_offset: length: expected: flags: 0: 0.. 127: 13312.. 13439: 128: encoded 1: 128.. 255: 13392.. 13519: 128: 13440: encoded 2: 256.. 291: 13480.. 13515: 36: 13520: last,encoded,eof testfile: 3 extents found $ compsize testfile Processed 1 file, 3 regular extents (3 refs), 0 inline, 1 fragments. Type Perc Disk Usage Uncompressed Referenced TOTAL 64% 188K 292K 292K lzo 64% 188K 292K 292K Signed-off-by: David Sterba

btrfs: defrag: extend ioctl to accept compression levels

2025-03-18T19:35:50+00:00

The zstd and zlib compression types support setting compression levels. Enhance the defrag interface to specify the levels as well. For zstd the negative (realtime) levels are also accepted. Reviewed-by: Qu Wenruo Signed-off-by: Daniel Vacek Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: add new ioctl to wait for cleaned subvolumes

2024-11-11T13:34:22+00:00

Add a new unprivileged ioctl that will let the command 'btrfs subvolume sync' work without the (privileged) SEARCH_TREE ioctl. There are several modes of operation, where the most common ones are to wait on a specific subvolume or all currently queued for cleaning. This is utilized e.g. in backup applications that delete subvolumes and wait until they're cleaned to check for remaining space. The other modes are for flexibility, e.g. for monitoring or checkpoints in the queue of deleted subvolumes, again without the need to use SEARCH_TREE. Notes: - waiting is interruptible, the timeout is set to 1 second and is not configurable - repeated calls to the ioctl see a different state, so this is inherently racy when using e.g. the count or peek next/last Use cases: - a subvolume A was deleted, wait for cleaning (WAIT_FOR_ONE) - a bunch of subvolumes were deleted, wait for all (WAIT_FOR_QUEUED or PEEK_LAST + WAIT_FOR_ONE) - count how many are queued (not blocking), for monitoring purposes - report progress (PEEK_NEXT), may miss some if cleaning is quick - own waiting in user space (PEEK_LAST until it's 0) Signed-off-by: David Sterba

btrfs: qgroup: validate btrfs_qgroup_inherit parameter

2024-03-05T16:13:24+00:00

[BUG] Currently btrfs can create subvolume with an invalid qgroup inherit without triggering any error: # mkfs.btrfs -O quota -f $dev # mount $dev $mnt # btrfs subvolume create -i 2/0 $mnt/subv1 # btrfs qgroup show -prce --sync $mnt Qgroupid Referenced Exclusive Path -------- ---------- --------- ---- 0/5 16.00KiB 16.00KiB 0/256 16.00KiB 16.00KiB subv1 [CAUSE] We only do a very basic size check for btrfs_qgroup_inherit structure, but never really verify if the values are correct. Thus in btrfs_qgroup_inherit() function, we have to skip non-existing qgroups, and never return any error. [FIX] Fix the behavior and introduce extra checks: - Introduce early check for btrfs_qgroup_inherit structure Not only the size, but also all the qgroup ids would be verified. And the timing is very early, so we can return error early. This early check is very important for snapshot creation, as snapshot is delayed to transaction commit. - Drop support for btrfs_qgroup_inherit::num_ref_copies and num_excl_copies Those two members are used to specify to copy refr/excl numbers from other qgroups. This would definitely mark qgroup inconsistent, and btrfs-progs has dropped the support for them for a long time. It's time to drop the support for kernel. - Verify the supported btrfs_qgroup_inherit::flags Just in case we want to add extra flags for btrfs_qgroup_inherit. Now above subvolume creation would fail with -ENOENT other than silently ignore the non-existing qgroup. CC: stable@vger.kernel.org # 6.7+ Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: defrag: reject unknown flags of btrfs_ioctl_defrag_range_args

2024-01-12T01:04:19+00:00

Add extra sanity check for btrfs_ioctl_defrag_range_args::flags. This is not really to enhance fuzzing tests, but as a preparation for future expansion on btrfs_ioctl_defrag_range_args. In the future we're going to add new members, allowing more fine tuning for btrfs defrag. Without the -ENONOTSUPP error, there would be no way to detect if the kernel supports those new defrag features. CC: stable@vger.kernel.org # 4.14+ Reviewed-by: Filipe Manana Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: qgroup: add new quota mode for simple quotas

2023-10-12T14:44:10+00:00

Add a new quota mode called "simple quotas". It can be enabled by the existing quota enable ioctl via a new command, and sets an incompat bit, as the implementation of simple quotas will make backwards incompatible changes to the disk format of the extent tree. Signed-off-by: Boris Burkov Signed-off-by: David Sterba

btrfs: read raid stripe tree from disk

2023-10-12T14:44:09+00:00

If we find the raid-stripe-tree on mount, read it from disk. This is a backward incompatible feature. The rescue=ignorebadroots mount option will skip this tree. Signed-off-by: Johannes Thumshirn Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: scrub: reject unsupported scrub flags

2023-04-17T17:52:19+00:00

Since the introduction of scrub interface, the only flag that we support is BTRFS_SCRUB_READONLY. Thus there is no sanity checks, if there are some undefined flags passed in, we just ignore them. This is problematic if we want to introduce new scrub flags, as we have no way to determine if such flags are supported. Address the problem by introducing a check for the flags, and if unsupported flags are set, return -EOPNOTSUPP to inform the user space. This check should be backported for all supported kernels before any new scrub flags are introduced. CC: stable@vger.kernel.org # 4.14+ Reviewed-by: Anand Jain Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: ioctl: return device fsid from DEV_INFO ioctl

2023-03-06T18:28:19+00:00

Currently user space utilizes dev info ioctl to grab the info of a certain devid, this includes its device uuid. But the returned info is not enough to determine if a device is a seed. Commit a26d60dedf9a ("btrfs: sysfs: add devinfo/fsid to retrieve actual fsid from the device") exports the same value in sysfs so this is for parity with ioctl. Add a new member, fsid, into btrfs_ioctl_dev_info_args, and populate the member with fsid value. This should not cause any compatibility problem, following the combinations: - Old user space, old kernel - Old user space, new kernel User space tool won't even check the new member. - New user space, old kernel The kernel won't touch the new member, and user space tool should zero out its argument, thus the new member is all zero. User space tool can then know the kernel doesn't support this fsid reporting, and falls back to whatever they can. - New user space, new kernel Go as planned. Would find the fsid member is no longer zero, and trust its value. Reviewed-by: Anand Jain Signed-off-by: Qu Wenruo Signed-off-by: David Sterba