linux.git/fs/fuse/dev.c, branch v6.16

fuse: support large folios for stores

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

Add support for folios larger than one page size for stores.
Also change variable naming from "this_num" to "nr_bytes".

Signed-off-by: Joanne Koong 
Reviewed-by: Josef Bacik 
Reviewed-by: Jeff Layton 
Signed-off-by: Miklos Szeredi

fuse: support large folios for retrieves

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

Add support for folios larger than one page size for retrieves.

Signed-off-by: Joanne Koong 
Reviewed-by: Josef Bacik 
Reviewed-by: Jeff Layton 
Reviewed-by: Bernd Schubert 
Signed-off-by: Miklos Szeredi

fuse: support copying large folios

2025-05-29T10:30:30+00:00

Currently, all folios associated with fuse are one page size. As part of
the work to enable large folios, this commit adds support for copying
to/from folios larger than one page size.

Signed-off-by: Joanne Koong 
Reviewed-by: Jeff Layton 
Reviewed-by: Bernd Schubert 
Signed-off-by: Miklos Szeredi

fs: fuse: add dev id to /dev/fuse fdinfo

2025-05-15T07:43:19+00:00

This commit add fuse connection device id to
fdinfo of opened /dev/fuse files.

Related discussions can be found at links below.

Link: https://lore.kernel.org/all/CAJfpegvEYUgEbpATpQx8NqVR33Mv-VK96C+gbTag1CEUeBqvnA@mail.gmail.com/
Signed-off-by: Chen Linxuan 
Signed-off-by: Miklos Szeredi

fuse: optimize over-io-uring request expiration check

2025-04-15T11:43:38+00:00

Currently, when checking whether a request has timed out, we check
fpq processing, but fuse-over-io-uring has one fpq per core and 256
entries in the processing table. For systems where there are a
large number of cores, this may be too much overhead.

Instead of checking the fpq processing list, check ent_w_req_queue
and ent_in_userspace.

Signed-off-by: Joanne Koong 
Reviewed-by: Bernd Schubert 
Signed-off-by: Miklos Szeredi

fuse: use boolean bit-fields in struct fuse_copy_state

2025-04-15T10:59:17+00:00

Refactor struct fuse_copy_state to use boolean bit-fields to improve
clarity/readability and be consistent with other fuse structs that use
bit-fields for boolean state (eg fuse_fs_context, fuse_args).

No functional changes.

Signed-off-by: Joanne Koong 
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

Merge tag 'fuse-update-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse

2025-04-02T23:36:59+00:00

Pull fuse updates from Miklos Szeredi:

 - Allow connection to server to time out (Joanne Koong)

 - If server doesn't support creating a hard link, return EPERM rather
   than ENOSYS (Matt Johnston)

 - Allow file names longer than 1024 chars (Bernd Schubert)

 - Fix a possible race if request on io_uring queue is interrupted
   (Bernd Schubert)

 - Misc fixes and cleanups

* tag 'fuse-update-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: remove unneeded atomic set in uring creation
  fuse: fix uring race condition for null dereference of fc
  fuse: Increase FUSE_NAME_MAX to PATH_MAX
  fuse: Allocate only namelen buf memory in fuse_notify_
  fuse: add default_request_timeout and max_request_timeout sysctls
  fuse: add kernel-enforced timeout option for requests
  fuse: optmize missing FUSE_LINK support
  fuse: Return EPERM rather than ENOSYS from link()
  fuse: removed unused function fuse_uring_create() from header
  fuse: {io-uring} Fix a possible req cancellation race

fuse: Increase FUSE_NAME_MAX to PATH_MAX

2025-03-31T12:59:27+00:00

Our file system has a translation capability for S3-to-posix.
The current value of 1kiB is enough to cover S3 keys, but
does not allow encoding of %xx escape characters.
The limit is increased to (PATH_MAX - 1), as we need
3 x 1024 and that is close to PATH_MAX (4kB) already.
-1 is used as the terminating null is not included in the
length calculation.

Testing large file names was hard with libfuse/example file systems,
so I created a new memfs that does not have a 255 file name length
limitation.
https://github.com/libfuse/libfuse/pull/1077

The connection is initialized with FUSE_NAME_LOW_MAX, which
is set to the previous value of FUSE_NAME_MAX of 1024. With
FUSE_MIN_READ_BUFFER of 8192 that is enough for two file names
+ fuse headers.
When FUSE_INIT reply sets max_pages to a value > 1 we know
that fuse daemon supports request buffers of at least 2 pages
(+ header) and can therefore hold 2 x PATH_MAX file names - operations
like rename or link that need two file names are no issue then.

Signed-off-by: Bernd Schubert 
Signed-off-by: Miklos Szeredi

fuse: Allocate only namelen buf memory in fuse_notify_

2025-03-31T12:59:27+00:00

fuse_notify_inval_entry and fuse_notify_delete were using fixed allocations
of FUSE_NAME_MAX to hold the file name. Often that large buffers are not
needed as file names might be smaller, so this uses the actual file name
size to do the allocation.

Signed-off-by: Bernd Schubert 
Reviewed-by: Jingbo Xu 
Signed-off-by: Miklos Szeredi