kernel/linux.git/fs/erofs, branch v7.0-rc7

erofs: fix .fadvise() for page cache sharing

2026-03-25T02:40:02+00:00

Currently, .fadvise() doesn't work well if page cache sharing is on since shared inodes belong to a pseudo fs generated with init_pseudo(), and sb->s_bdi is the default one &noop_backing_dev_info. Then, generic_fadvise() will just behave as a no-op if sb->s_bdi is &noop_backing_dev_info, but as the bdev fs (the bdev fs changes inode_to_bdi() instead), it's actually NOT a pure memfs. Let's generate a real bdi for erofs_ishare_mnt instead. Fixes: d86d7817c042 ("erofs: implement .fadvise for page cache share") Reviewed-by: Hongbo Li Signed-off-by: Gao Xiang

erofs: update the Kconfig description

2026-03-24T16:04:41+00:00

Refine the description to better highlight its features and use cases. In addition, add instructions for building it as a module and clarify the compression option. Reviewed-by: Chao Yu Signed-off-by: Gao Xiang

erofs: add GFP_NOIO in the bio completion if needed

2026-03-18T16:24:21+00:00

The bio completion path in the process context (e.g. dm-verity) will directly call into decompression rather than trigger another workqueue context for minimal scheduling latencies, which can then call vm_map_ram() with GFP_KERNEL. Due to insufficient memory, vm_map_ram() may generate memory swapping I/O, which can cause submit_bio_wait to deadlock in some scenarios. Trimmed down the call stack, as follows: f2fs_submit_read_io submit_bio //bio_list is initialized. mmc_blk_mq_recovery z_erofs_endio vm_map_ram __pte_alloc_kernel __alloc_pages_direct_reclaim shrink_folio_list __swap_writepage submit_bio_wait //bio_list is non-NULL, hang!!! Use memalloc_noio_{save,restore}() to wrap up this path. Reviewed-by: Gao Xiang Signed-off-by: Jiucheng Xu Reviewed-by: Chao Yu Signed-off-by: Gao Xiang

erofs: set fileio bio failed in short read case

2026-03-17T02:27:31+00:00

For file-backed mount, IO requests are handled by vfs_iocb_iter_read(). However, it can be interrupted by SIGKILL, returning the number of bytes actually copied. Unused folios in bio are unexpectedly marked as uptodate. vfs_read filemap_read filemap_get_pages filemap_readahead erofs_fileio_readahead erofs_fileio_rq_submit vfs_iocb_iter_read filemap_read filemap_get_pages <= detect signal erofs_fileio_ki_complete <= set all folios uptodate This patch addresses this by setting short read bio with an error directly. Fixes: bc804a8d7e86 ("erofs: handle end of filesystem properly for file-backed mounts") Reported-by: chenguanyou Signed-off-by: Yunlei He Signed-off-by: Sheng Yong Reviewed-by: Gao Xiang Reviewed-by: Chao Yu Signed-off-by: Gao Xiang

erofs: fix interlaced plain identification for encoded extents

2026-02-25T09:40:58+00:00

Only plain data whose start position and on-disk physical length are both aligned to the block size should be classified as interlaced plain extents. Otherwise, it must be treated as shifted plain extents. This issue was found by syzbot using a crafted compressed image containing plain extents with unaligned physical lengths, which can cause OOB read in z_erofs_transform_plain(). Reported-and-tested-by: syzbot+d988dc155e740d76a331@syzkaller.appspotmail.com Closes: https://lore.kernel.org/r/699d5714.050a0220.cdd3c.03e7.GAE@google.com Fixes: 1d191b4ca51d ("erofs: implement encoded extent metadata") Signed-off-by: Gao Xiang

erofs: remove more unnecessary #ifdefs

2026-02-24T10:36:52+00:00

Many #ifdefs can be replaced with IS_ENABLED() to improve code readability. No functional changes. Signed-off-by: Ferry Meng Reviewed-by: Gao Xiang Signed-off-by: Gao Xiang

erofs: allow sharing page cache with the same aops only

2026-02-23T10:04:18+00:00

Inode with identical data but different @aops cannot be mixed because the page cache is managed by different subsystems (e.g., @aops for compressed on-disk inodes cannot handle plain on-disk inodes). In this patch, we never allow inodes to share the page cache among plain, compressed, and fileio cases. When a shared inode is created, we initialize @aops that is the same as the initial real inode, and subsequent inodes cannot share the page cache if the inferred @aops differ from the corresponding shared inode. This is reasonable as a first step because, in typical use cases, if an inode is compressible, it will fall into compressed inodes across different filesystem images unless users use plain filesystems. However, in that cases, users will use plain filesystems all the time. Fixes: 5ef3208e3be5 ("erofs: introduce the page cache share feature") Signed-off-by: Hongbo Li Reviewed-by: Gao Xiang Signed-off-by: Gao Xiang

Convert remaining multi-line kmalloc_obj/flex GFP_KERNEL uses

2026-02-22T16:26:33+00:00

Conversion performed via this Coccinelle script: // SPDX-License-Identifier: GPL-2.0-only // Options: --include-headers-for-types --all-includes --include-headers --keep-comments virtual patch @gfp depends on patch && !(file in "tools") && !(file in "samples")@ identifier ALLOC = {kmalloc_obj,kmalloc_objs,kmalloc_flex, kzalloc_obj,kzalloc_objs,kzalloc_flex, kvmalloc_obj,kvmalloc_objs,kvmalloc_flex, kvzalloc_obj,kvzalloc_objs,kvzalloc_flex}; @@ ALLOC(... - , GFP_KERNEL ) $ make coccicheck MODE=patch COCCI=gfp.cocci Build and boot tested x86_64 with Fedora 42's GCC and Clang: Linux version 6.19.0+ (user@host) (gcc (GCC) 15.2.1 20260123 (Red Hat 15.2.1-7), GNU ld version 2.44-12.fc42) #1 SMP PREEMPT_DYNAMIC 1970-01-01 Linux version 6.19.0+ (user@host) (clang version 20.1.8 (Fedora 20.1.8-4.fc42), LLD 20.1.8) #1 SMP PREEMPT_DYNAMIC 1970-01-01 Signed-off-by: Kees Cook Signed-off-by: Linus Torvalds

Convert more 'alloc_obj' cases to default GFP_KERNEL arguments

2026-02-22T04:03:00+00:00

This converts some of the visually simpler cases that have been split over multiple lines. I only did the ones that are easy to verify the resulting diff by having just that final GFP_KERNEL argument on the next line. Somebody should probably do a proper coccinelle script for this, but for me the trivial script actually resulted in an assertion failure in the middle of the script. I probably had made it a bit _too_ trivial. So after fighting that far a while I decided to just do some of the syntactically simpler cases with variations of the previous 'sed' scripts. The more syntactically complex multi-line cases would mostly really want whitespace cleanup anyway. Signed-off-by: Linus Torvalds

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 '\