kernel/linux.git/fs/fuse/readdir.c, branch v6.19.11

fuse: increase readdir buffer size

2025-05-29T10:31:24+00:00

Increase the buffer size to the count requested by userspace. This improves performance. Signed-off-by: Miklos Szeredi Signed-off-by: Bernd Schubert

fuse: don't allow signals to interrupt getdents copying

2025-05-29T10:31:23+00:00

When getting the directory contents, the entries are first fetched to a kernel buffer, then they are copied to userspace with dir_emit(). This second phase is non-blocking as long as the userspace buffer is not paged out, making it interruptible makes zero sense. Overload d_type as flags, since it only uses 4 bits from 32. Reviewed-by: Bernd Schubert Signed-off-by: Miklos Szeredi

fuse: add more control over cache invalidation behaviour

2025-04-15T10:56:40+00:00

Currently userspace is able to notify the kernel to invalidate the cache for an inode. This means that, if all the inodes in a filesystem need to be invalidated, then userspace needs to iterate through all of them and do this kernel notification separately. This patch adds the concept of 'epoch': each fuse connection will have the current epoch initialized and every new dentry will have it's d_time set to the current epoch value. A new operation will then allow userspace to increment the epoch value. Every time a dentry is d_revalidate()'ed, it's epoch is compared with the current connection epoch and invalidated if it's value is different. Signed-off-by: Luis Henriques Tested-by: Laura Promberger Signed-off-by: Miklos Szeredi

fuse: check attributes staleness on fuse_iget()

2024-11-18T11:24:13+00:00

Function fuse_direntplus_link() might call fuse_iget() to initialize a new fuse_inode and change its attributes. If fi->attr_version is always initialized with 0, even if the attributes returned by the FUSE_READDIR request is staled, as the new fi->attr_version is 0, fuse_change_attributes will still set the staled attributes to inode. This wrong behaviour may cause file size inconsistency even when there is no changes from server-side. To reproduce the issue, consider the following 2 programs (A and B) are running concurrently, A B ---------------------------------- -------------------------------- { /fusemnt/dir/f is a file path in a fuse mount, the size of f is 0. } readdir(/fusemnt/dir) start //Daemon set size 0 to f direntry fallocate(f, 1024) stat(f) // B see size 1024 echo 2 > /proc/sys/vm/drop_caches readdir(/fusemnt/dir) reply to kernel Kernel set 0 to the I_NEW inode stat(f) // B see size 0 In the above case, only program B is modifying the file size, however, B observes file size changing between the 2 'readonly' stat() calls. To fix this issue, we should make sure readdirplus still follows the rule of attr_version staleness checking even if the fi->attr_version is lost due to inode eviction. To identify this situation, the new fc->evict_ctr is used to record whether the eviction of inodes occurs during the readdirplus request processing. If it does, the result of readdirplus may be inaccurate; otherwise, the result of readdirplus can be trusted. Although this may still lead to incorrect invalidation, considering the relatively low frequency of evict occurrences, it should be acceptable. Link: https://lore.kernel.org/lkml/20230711043405.66256-2-zhangjiachen.jaycee@bytedance.com/ Link: https://lore.kernel.org/lkml/20241114070905.48901-1-zhangtianci.1997@bytedance.com/ Reported-by: Jiachen Zhang Suggested-by: Miklos Szeredi Signed-off-by: Zhang Tianci Signed-off-by: Miklos Szeredi

fuse: remove pages for requests and exclusively use folios

2024-11-05T13:08:35+00:00

All fuse requests use folios instead of pages for transferring data. Remove pages from the requests and exclusively use folios. No functional changes. [SzM: rename back folio_descs -> descs, etc.] Signed-off-by: Joanne Koong Reviewed-by: Josef Bacik Signed-off-by: Miklos Szeredi

fuse: convert readdir to use folios

2024-11-05T10:14:32+00:00

Convert readdir requests to use a folio instead of a page. No functional changes. Signed-off-by: Joanne Koong Reviewed-by: Josef Bacik Signed-off-by: Miklos Szeredi

fuse: get rid of ff->readdir.lock

2024-03-06T15:20:58+00:00

The same protection is provided by file->f_pos_lock. Note, this relies on the fact that file->f_mode has FMODE_ATOMIC_POS. This flag is cleared by stream_open(), which would prevent locking of f_pos_lock. Prior to commit 7de64d521bf9 ("fuse: break up fuse_open_common()") FOPEN_STREAM on a directory would cause stream_open() to be called. After this commit this is not done anymore, so f_pos_lock will always be locked. Signed-off-by: Miklos Szeredi

fuse: convert to new timestamp accessors

2023-10-18T12:08:21+00:00

Convert to using the new inode timestamp accessor functions. Signed-off-by: Jeff Layton Link: https://lore.kernel.org/r/20231004185347.80880-37-jlayton@kernel.org Signed-off-by: Christian Brauner

fuse: cache btime

2023-08-21T10:14:59+00:00

Not all inode attributes are supported by all filesystems, but for the basic stats (which are returned by stat(2) and friends) all of them will have some value, even if that doesn't reflect a real attribute of the file. Btime is different, in that filesystems are free to report or not report a value in statx. If the value is available, then STATX_BTIME bit is set in stx_mask. When caching the value of btime, remember the availability of the attribute as well as the value (if available). This is done by using the FUSE_I_BTIME bit in fuse_inode->state to indicate availability, while using fuse_inode->inval_mask & STATX_BTIME to indicate the state of the cache itself (i.e. set if cache is invalid, and cleared if cache is valid). Signed-off-by: Miklos Szeredi

fuse: add ATTR_TIMEOUT macro

2023-08-16T10:39:41+00:00

Next patch will introduce yet another type attribute reply. Add a macro that can handle attribute timeouts for all of the structs. Signed-off-by: Miklos Szeredi