kernel/linux.git/fs/btrfs/compression.c, 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: 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: fix typos in comments and strings

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

Annual typo fixing pass. Strangely codespell found only about 30% of what is in this patch, the rest was done manually using text spellchecker with a custom dictionary of acceptable terms. Reviewed-by: Neal Gompa 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: migrate to use per-fs workspace manager

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

There are several interfaces involved for each algorithm: - alloc workspace All algorithms allocate a workspace without the need for workspace manager. So no change needs to be done. - get workspace This involves checking the workspace manager to find a free one, and if not, allocate a new one. For none and lzo, they share the same generic btrfs_get_workspace() helper, only needs to update that function to use the per-fs manager. For zlib it uses a wrapper around btrfs_get_workspace(), so no special work needed. For zstd, update zstd_find_workspace() and zstd_get_workspace() to utilize the per-fs manager. - put workspace For none/zlib/lzo they share the same btrfs_put_workspace(), update that function to use the per-fs manager. For zstd, it's zstd_put_workspace(), the same update. - zstd specific timer This is the timer to reclaim workspace, change it to grab the per-fs workspace manager instead. Now all workspace are managed by the per-fs manager. Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: add generic workspace manager initialization

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

This involves: - Add (alloc|free)_workspace_manager helpers. These are the helper to alloc/free workspace_manager structure. The allocator will allocate a workspace_manager structure, initialize it, and pre-allocate one workspace for it. The freer will do the cleanup and set the manager pointer to NULL. - Call alloc_workspace_manager() inside btrfs_alloc_compress_wsm() - Call alloc_workspace_manager() inside btrfs_free_compress_wsm() For none, zlib and lzo compression algorithms. For now the generic per-fs workspace managers 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 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