kernel/git/stable/linux.git/fs/erofs/fscache.c, branch master

erofs: remove fscache backend entirely

2026-06-22T03:00:06+00:00

EROFS over fscache was introduced to provide image lazy pulling functionality. After the feature landed, the fscache subsystem made netfs a new hard dependency, which is unexpected for a local filesystem and has an kernel-defined caching hierarchy which could be inflexible compared to the fanotify pre-content hooks. Therefore, this feature has been deprecated for almost two years. As EROFS file-backed mounts and fanotify pre-content hooks both upstream for a while and already providing equivalent functionality (erofs-utils has supported fanotify pre-content hooks), let's remove the fscache backend now. The main application of this feature is Nydus [1], and they plan to move to use fanotify pre-content hooks in the near future too. I hope this patch can be merged into Linux 7.2, which is also motivated by newly found implementation issues [2][3] that are not worth investigating given the deprecation and limited development resources. The associated fscache/cachefiles cleanup patch will follow separately through the vfs tree (netfs) later: it seems fine since the codebase is isolated by CONFIG_CACHEFILES_ONDEMAND. [1] https://github.com/dragonflyoss/nydus/blob/v2.1.0/docs/nydus-fscache.md [2] https://github.com/dragonflyoss/nydus/pull/1824 [3] https://lore.kernel.org/r/20260619135800.1594811-1-michael.bommarito@gmail.com Acked-by: Jingbo Xu Signed-off-by: Gao Xiang

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

erofs: using domain_id in the safer way

2026-01-23T12:02:09+00:00

Either the existing fscache usecase or the upcoming page cache sharing case, the `domain_id` should be protected as sensitive information, so we use the safer helpers to allocate, free and display domain_id. Signed-off-by: Hongbo Li Reviewed-by: Gao Xiang Signed-off-by: Gao Xiang

erofs: decouple `struct erofs_anon_fs_type`

2026-01-23T12:01:13+00:00

- Move the `struct erofs_anon_fs_type` to super.c and expose it in preparation for the upcoming page cache share feature; - Remove the `.owner` field, as they are all internal mounts and fully managed by EROFS. Retaining `.owner` would unnecessarily increment module reference counts, preventing the EROFS kernel module from being unloaded. Signed-off-by: Gao Xiang

erofs: get rid of raw bi_end_io() usage

2025-11-30T15:55:13+00:00

These BIOs are actually harmless in practice, as they are all pseudo BIOs and do not use advanced features like chaining. Using the BIO interface is a more friendly and unified approach for both bdev and and file-backed I/Os (compared to awkward bvec interfaces). Let's use bio_endio() instead. Reviewed-by: Christoph Hellwig Reviewed-by: Ming Lei Reviewed-by: Chao Yu Signed-off-by: Gao Xiang

erofs: implement metadata compression

2025-07-24T11:43:31+00:00

Thanks to the meta buffer infrastructure, metadata-compressed inodes are just read from the metabox inode instead of the blockdevice (or backing file) inode. The same is true for shared extended attributes. When metadata compression is enabled, inode numbers are divided from on-disk NIDs because of non-LTS 32-bit application compatibility. Co-developed-by: Gao Xiang Signed-off-by: Bo Liu (OpenAnolis) Acked-by: Chao Yu Signed-off-by: Gao Xiang Link: https://lore.kernel.org/r/20250722003229.2121752-1-hsiangkao@linux.alibaba.com

erofs: remove need_kmap in erofs_read_metabuf()

2025-07-24T11:42:05+00:00

- need_kmap is always true except for a ztailpacking case; thus, just open-code that one; - The upcoming metadata compression will add a new boolean, so simplify this first. Signed-off-by: Gao Xiang Reviewed-by: Chao Yu Link: https://lore.kernel.org/r/20250714090907.4095645-1-hsiangkao@linux.alibaba.com

netfs: Fix the request's work item to not require a ref

2025-05-21T12:35:20+00:00

When the netfs_io_request struct's work item is queued, it must be supplied with a ref to the work item struct to prevent it being deallocated whilst on the queue or whilst it is being processed. This is tricky to manage as we have to get a ref before we try and queue it and then we may find it's already queued and is thus already holding a ref - in which case we have to try and get rid of the ref again. The problem comes if we're in BH or IRQ context and need to drop the ref: if netfs_put_request() reduces the count to 0, we have to do the cleanup - but the cleanup may need to wait. Fix this by adding a new work item to the request, ->cleanup_work, and dispatching that when the refcount hits zero. That can then synchronously cancel any outstanding work on the main work item before doing the cleanup. Adding a new work item also deals with another problem upstream where it's sometimes changing the work func in the put function and requeuing it - which has occasionally in the past caused the cleanup to happen incorrectly. As a bonus, this allows us to get rid of the 'was_async' parameter from a bunch of functions. This indicated whether the put function might not be permitted to sleep. Fixes: 3d3c95046742 ("netfs: Provide readahead and readpage netfs helpers") Signed-off-by: David Howells Link: https://lore.kernel.org/20250519090707.2848510-4-dhowells@redhat.com cc: Paulo Alcantara cc: Marc Dionne cc: Steve French cc: linux-cifs@vger.kernel.org cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner

erofs: get rid of erofs_kmap_type

2025-03-16T17:21:24+00:00

Since EROFS_KMAP_ATOMIC is no longer valid, get rid of erofs_kmap_type too. Signed-off-by: Bo Liu Reviewed-by: Gao Xiang Reviewed-by: Chao Yu Link: https://lore.kernel.org/r/20250217093141.2659-1-liubo03@inspur.com Signed-off-by: Gao Xiang