kernel/git/stable/linux.git/fs/btrfs/free-space-cache.h, branch master

btrfs: remove op field from struct btrfs_free_space_ctl

2026-06-08T13:53:29+00:00

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 Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: reduce size of struct btrfs_free_space_ctl

2026-06-08T13:53:29+00:00

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 Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: remove unit field from struct btrfs_free_space_ctl

2026-06-08T13:53:29+00:00

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 Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: remove start field from struct btrfs_free_space_ctl

2026-06-08T13:53:29+00:00

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 Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: handle discarding fully-remapped block groups

2026-02-03T06:54:36+00:00

Discard normally works by iterating over the free-space entries of a block group. This doesn't work for fully-remapped block groups, as we removed their free-space entries when we started relocation. For sync discard, call btrfs_discard_extent() when we commit the transaction in which the last identity remap was removed. For async discard, add a new function btrfs_trim_fully_remapped_block_group() to be called by the discard worker, which iterates over the block group's range using the normal async discard rules. Once we reach the end, remove the chunk's stripes and device extents to get back its free space. Reviewed-by: Boris Burkov Signed-off-by: Mark Harmstone Signed-off-by: David Sterba

btrfs: add cancellation points to trim loops

2024-10-07T21:21:56+00:00

There are reports that system cannot suspend due to running trim because the task responsible for trimming the device isn't able to finish in time, especially since we have a free extent discarding phase, which can trim a lot of unallocated space. There are no limits on the trim size (unlike the block group part). Since trime isn't a critical call it can be interrupted at any time, in such cases we stop the trim, report the amount of discarded bytes and return an error. Link: https://bugzilla.kernel.org/show_bug.cgi?id=219180 Link: https://bugzilla.suse.com/show_bug.cgi?id=1229737 CC: stable@vger.kernel.org # 5.15+ Signed-off-by: Luca Stefani Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: add forward declarations and headers, part 2

2024-03-04T15:24:49+00:00

Do a cleanup in more headers: - add forward declarations for types referenced by pointers - add includes when types need them This fixes potential compilation problems if the headers are reordered or the missing includes are not provided indirectly. Signed-off-by: David Sterba

btrfs: mark __btrfs_add_free_space static

2024-03-04T15:24:48+00:00

__btrfs_add_free_space is only used in free-space-cache.c, so mark it static. Reviewed-by: Johannes Thumshirn Signed-off-by: Lijuan Li Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: move btrfs_check_trunc_cache_free_space into block-rsv.c

2023-06-19T11:59:24+00:00

This is completely related to block rsv's, move it out of the free space cache code and into block-rsv.c. Reviewed-by: Johannes Thumshirn Signed-off-by: Josef Bacik Signed-off-by: David Sterba

btrfs: convert discard stat defs to enum

2022-12-05T17:00:45+00:00

Do away with the defines and use an enum as it's cleaner. Suggested-by: Johannes Thumshirn Reviewed-by: Johannes Thumshirn Signed-off-by: Josef Bacik Reviewed-by: David Sterba Signed-off-by: David Sterba