kernel/linux.git/fs/smb/client/compress.c, branch linux-7.0.y

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

cifs: Do some preparation prior to organising the function declarations

2025-12-05T23:11:55+00:00

Make some preparatory cleanups prior to running a script to organise the function declarations within the fs/smb/client/ headers. These include: (1) Remove "inline" from the dummy cifs_proc_init/clean() functions as they are in a .c file. (2) Move should_compress()'s kdoc comment to the .c file and remove kdoc markers from the comments. (3) Rename CIFS_ALLOW_INSECURE_LEGACY in #endif comments to have CONFIG_ on the front to allow the script to recognise it. (4) Don't let comments have bare words at the left margin as that confused the simplistic function detection code in the script. (5) Adjust some argument lists so that when and if the cleanup script is run they don't end up over 100 chars. (6) Fix a few comments to have missing '*' added or the "*/" moved to their own lines so that checkpatch doesn't moan over the cleanup script patch. (7) Move struct cifs_calc_sig_ctx to cifsglob.h. (8) Remove some __KERNEL__ conditionals. Signed-off-by: David Howells Reviewed-by: Paulo Alcantara (Red Hat) cc: linux-cifs@vger.kernel.org Signed-off-by: Steve French

cifs: Add a tracepoint to log EIO errors

2025-12-05T23:11:43+00:00

Add a tracepoint to log EIO errors and give it the capacity to convey up to two integers of information. This is then wrapped with three functions: int smb_EIO(enum smb_eio_trace trace) int smb_EIO1(enum smb_eio_trace trace, unsigned long info) int smb_EIO2(enum smb_eio_trace trace, unsigned long info, unsigned long info2) depending on how many bits of info are desired to be logged with any particular trace. The functions all return -EIO and can be used in place of -EIO. The trace argument is an enum value that gets translated to a string when the trace is printed. This makes is easier to log EIO instances when the client is under high load than turning on a printk wrapper such as cifs_dbg(). Granted, EIO could have its own separate EIO printing since EIO shouldn't happen. Signed-off-by: David Howells Reviewed-by: Paulo Alcantara (Red Hat) cc: linux-cifs@vger.kernel.org cc: linux-fsdevel@vger.kernel.org Signed-off-by: Steve French

cifs: Fix collect_sample() to handle any iterator type

2025-08-12T04:20:07+00:00

collect_sample() is used to gather samples of the data in a Write op for analysis to try and determine if the compression algorithm is likely to achieve anything more quickly than actually running the compression algorithm. However, collect_sample() assumes that the data it is going to be sampling is stored in an ITER_XARRAY-type iterator (which it now should never be) and doesn't actually check that it is before accessing the underlying xarray directly. Fix this by replacing the code with a loop that just uses the standard iterator functions to sample every other 2KiB block, skipping the intervening ones. It's not quite the same as the previous algorithm as it doesn't necessarily align to the pages within an ordinary write from the pagecache. Note that the btrfs code from which this was derived samples the inode's pagecache directly rather than the iterator - but that doesn't necessarily work for network filesystems if O_DIRECT is in operation. Fixes: 94ae8c3fee94 ("smb: client: compress: LZ77 code improvements cleanup") Signed-off-by: David Howells Acked-by: Paulo Alcantara (Red Hat) cc: Enzo Matsumiya cc: Shyam Prasad N cc: Tom Talpey cc: linux-cifs@vger.kernel.org cc: linux-fsdevel@vger.kernel.org Signed-off-by: Steve French

smb/client: Fix logically dead code

2024-10-16T05:30:52+00:00

The if condition in collect_sample: can never be satisfied because of a logical contradiction. The indicated dead code may have performed some action; that action will never occur. Fixes: 94ae8c3fee94 ("smb: client: compress: LZ77 code improvements cleanup") Signed-off-by: Advait Dhamorikar Signed-off-by: Steve French

smb: client: fix compression heuristic functions

2024-09-17T01:10:39+00:00

Change is_compressible() return type to bool, use WARN_ON_ONCE(1) for internal errors and return false for those. Renames: check_repeated_data -> has_repeated_data check_ascii_bytes -> is_mostly_ascii (also refactor into a single loop) calc_shannon_entropy -> has_low_entropy Also wraps "wreq->Length" in le32_to_cpu() in should_compress() (caught by sparse). Signed-off-by: Enzo Matsumiya Suggested-by: Dan Carpenter Signed-off-by: Steve French

smb: client: compress: fix an "illegal accesses" issue

2024-09-15T15:42:45+00:00

Using uninitialized value "bkt" when calling "kfree" Fixes: 13b68d44990d ("smb: client: compress: LZ77 code improvements cleanup") Signed-off-by: Qianqiang Liu Reviewed-by: Dan Carpenter Signed-off-by: Steve French

smb: client: compress: fix a potential issue of freeing an invalid pointer

2024-09-15T15:42:45+00:00

The dst pointer may not be initialized when calling kvfree(dst) Fixes: 13b68d44990d9 ("smb: client: compress: LZ77 code improvements cleanup") Signed-off-by: Qianqiang Liu Signed-off-by: Steve French

smb: client: compress: LZ77 code improvements cleanup

2024-09-15T15:42:45+00:00

- Check data compressibility with some heuristics (copied from btrfs): - should_compress() final decision is is_compressible(data) - Cleanup compress/lz77.h leaving only lz77_compress() exposed: - Move parts to compress/lz77.c, while removing the rest of it because they were either unused, used only once, were implemented wrong (thanks to David Howells for the help) - Updated the compression parameters (still compatible with Windows implementation) trading off ~20% compression ratio for ~40% performance: - min match len: 3 -> 4 - max distance: 8KiB -> 1KiB - hash table type: u32 * -> u64 * Known bugs: This implementation currently works fine in general, but breaks with some payloads used during testing. Investigation ongoing, to be fixed in a next commit. Signed-off-by: Enzo Matsumiya Co-developed-by: David Howells Signed-off-by: David Howells Signed-off-by: Steve French