kernel/linux.git/fs/btrfs/compression.h, branch v6.18.22

btrfs: remove btrfs_bio::fs_info by extracting it from btrfs_bio::inode

2026-02-26T22:58:58+00:00

[ Upstream commit 81cea6cd7041ebd42281e0517f856d88527d3326 ] Currently there is only one caller which doesn't populate btrfs_bio::inode, and that's scrub. The idea is scrub doesn't want any automatic csum verification nor read-repair, as everything will be handled by scrub itself. However that behavior is really no different than metadata inode, thus we can reuse btree_inode as btrfs_bio::inode for scrub. The only exception is in btrfs_submit_chunk() where if a bbio is from scrub or data reloc inode, we set rst_search_commit_root to true. This means we still need a way to distinguish scrub from metadata, but that can be done by a new flag inside btrfs_bio. Now btrfs_bio::inode is a mandatory parameter, we can extract fs_info from that inode thus can remove btrfs_bio::fs_info to save 8 bytes from btrfs_bio structure. Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba Stable-dep-of: b39b26e017c7 ("btrfs: zoned: don't zone append to conventional zone") Signed-off-by: Sasha Levin

btrfs: headers cleanup to remove unnecessary local includes

2026-02-26T22:58:58+00:00

[ Upstream commit c5667f9c8eb90293dfa4e52c65eb89fe39f5652d ] [BUG] When I tried to remove btrfs_bio::fs_info and use btrfs_bio::inode to grab the fs_info, the header "btrfs_inode.h" is needed to access the full btrfs_inode structure. Then btrfs will fail to compile. [CAUSE] There is a recursive including chain: "bio.h" -> "btrfs_inode.h" -> "extent_map.h" -> "compression.h" -> "bio.h" That recursive including is causing problems for btrfs. [ENHANCEMENT] To reduce the risk of recursive including: - Remove unnecessary local includes from btrfs headers Either the included header is pulled in by other headers, or is completely unnecessary. - Remove btrfs local includes if the header only requires a pointer In that case let the implementing C file to pull the required header. This is especially important for headers like "btrfs_inode.h" which pulls in a lot of other btrfs headers, thus it's a mine field of recursive including. - Remove unnecessary temporary structure definition Either if we have included the header defining the structure, or completely unused. Now including "btrfs_inode.h" inside "bio.h" is completely fine, although "btrfs_inode.h" still includes "extent_map.h", but that header only includes "fs.h", no more chain back to "bio.h". Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba Stable-dep-of: b39b26e017c7 ("btrfs: zoned: don't zone append to conventional zone") Signed-off-by: Sasha Levin

btrfs: prepare compression folio alloc/free for bs > ps cases

2025-09-23T06:49:24+00:00

This includes the following preparation for bs > ps cases: - Always alloc/free the folio directly if bs > ps This adds a new @fs_info parameter for btrfs_alloc_compr_folio(), thus affecting all compression algorithms. For btrfs_free_compr_folio() it needs no parameter for now, as we can use the folio size to skip the caching part. For now the change is just to passing a @fs_info into the function, all the folio size assumption is still based on page size. - Properly zero the last folio in compress_file_range() Since the compressed folios can be larger than a page, we need to properly zero the whole folio. - Use correct folio size for btrfs_add_compressed_bio_folios() Instead of page size, use the correct folio size. - Use correct folio size/shift for btrfs_compress_filemap_get_folio() As we are not only using simple page sized folios anymore. - Use correct folio size for btrfs_decompress() There is an ASSERT() making sure the decompressed range is no larger than a page, which will be triggered for bs > ps cases. - Skip readahead for compressed pages Similar to subpage cases. - Make btrfs_alloc_folio_array() to accept a new @order parameter - Add a helper to calculate the minimal folio size All those changes should not affect the existing bs <= ps handling. Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: rename btrfs_compress_op to btrfs_compress_levels

2025-09-23T06:49:16+00:00

Since all workspace managers are per-fs, there is no need nor no way to store them inside btrfs_compress_op::wsm anymore. With that said, we can do the following modifications: - Remove zstd_workspace_mananger::ops Zstd always grab the global btrfs_compress_op[]. - Remove btrfs_compress_op::wsm member - Rename btrfs_compress_op to btrfs_compress_levels This should make it more clear that btrfs_compress_levels structures are only to indicate the levels of each compress algorithm. Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: cleanup the per-module compression workspace managers

2025-09-23T06:49:16+00:00

Since all workspaces are handled by the per-fs workspace managers, we can safely remove the old per-module managers. Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: add workspace manager initialization for zstd

2025-09-23T06:49:15+00:00

This involves: - Add zstd_alloc_workspace_manager() and zstd_free_workspace_manager() Those two functions will accept an fs_info pointer, and alloc/free fs_info->compr_wsm[BTRFS_COMPRESS_ZSTD] pointer. - Add btrfs_alloc_compress_wsm() and btrfs_free_compress_wsm() Those are helpers allocating the workspace managers for all algorithms. For now only zstd is supported, and the timing is a little unusual, the btrfs_alloc_compress_wsm() should only be called after the sectorsize being initialized. Meanwhile btrfs_free_fs_info_compress() is called in btrfs_free_fs_info(). - Move the definition of btrfs_compression_type to "fs.h" The reason is that "compression.h" has already included "fs.h", thus we can not just include "compression.h" to get the definition of BTRFS_NR_COMPRESS_TYPES to define fs_info::compr_wsm[]. For now the per-fs zstd workspace manager won't really have any effect, and all compression is still going through the global workspace manager. Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: add an fs_info parameter for compression workspace manager

2025-09-23T06:49:15+00:00

[BACKGROUND] Currently btrfs shares workspaces and their managers for all filesystems, this is mostly fine as all those workspaces are using page size based buffers, and btrfs only support block size (bs) <= page size (ps). This means even if bs < ps, we at most waste some buffer space in the workspace, but everything will still work fine. The problem here is that is limiting our support for bs > ps cases. As now a workspace now may need larger buffer to handle bs > ps cases, but since the pool has no way to distinguish different workspaces, a regular workspace (which is still using buffer size based on ps) can be passed to a btrfs whose bs > ps. In that case the buffer is not large enough, and will cause various problems. [ENHANCEMENT] To prepare for the per-fs workspace migration, add an fs_info parameter to all workspace related functions. For now this new fs_info parameter is not yet utilized. Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: pass btrfs_inode pointer directly into btrfs_compress_folios()

2025-09-22T08:54:31+00:00

For the 3 supported compression algorithms, two of them (zstd and zlib) are already grabbing the btrfs inode for error messages. It's more common to pass btrfs_inode and grab the address space from it. Reviewed-by: Anand Jain Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: reject invalid compression level

2025-09-18T11:18:49+00:00

Inspired by recent changes to compression level parsing in 6db1df415d73fc ("btrfs: accept and ignore compression level for lzo") it turns out that we do not do any extra validation for compression level input string, thus allowing things like "compress=lzo:invalid" to be accepted without warnings. Although we accept levels that are beyond the supported algorithm ranges, accepting completely invalid level specification is not correct. Fix the too loose checks for compression level, by doing proper error handling of kstrtoint(), so that we will reject not only too large values (beyond int range) but also completely wrong levels like "lzo:invalid". 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