linux-stable.git/fs/fuse/dir.c, branch v6.9

fuse: fix leaked ENOSYS error on first statx call

2024-04-15T08:12:44+00:00

FUSE attempts to detect server support for statx by trying it once and
setting no_statx=1 if it fails with ENOSYS, but consider the following
scenario:

- Userspace (e.g. sh) calls stat() on a file
  * succeeds
- Userspace (e.g. lsd) calls statx(BTIME) on the same file
  - request_mask = STATX_BASIC_STATS | STATX_BTIME
  - first pass: sync=true due to differing cache_mask
  - statx fails and returns ENOSYS
  - set no_statx and retry
  - retry sets mask = STATX_BASIC_STATS
  - now mask == cache_mask; sync=false (time_before: still valid)
  - so we take the "else if (stat)" path
  - "err" is still ENOSYS from the failed statx call

Fix this by zeroing "err" before retrying the failed call.

Fixes: d3045530bdd2 ("fuse: implement statx")
Cc: stable@vger.kernel.org # v6.6
Signed-off-by: Danny Lin 
Signed-off-by: Miklos Szeredi

fuse: fix typo for fuse_permission comment

2024-03-06T08:56:11+00:00

Found by chance while working on support for idmapped mounts in fuse.

Signed-off-by: Alexander Mikhalitsyn 
Signed-off-by: Miklos Szeredi

fuse: fix root lookup with nonzero generation

2024-03-05T12:40:42+00:00

The root inode has a fixed nodeid and generation (1, 0).

Prior to the commit 15db16837a35 ("fuse: fix illegal access to inode with
reused nodeid") generation number on lookup was ignored.  After this commit
lookup with the wrong generation number resulted in the inode being
unhashed.  This is correct for non-root inodes, but replacing the root
inode is wrong and results in weird behavior.

Fix by reverting to the old behavior if ignoring the generation for the
root inode, but issuing a warning in dmesg.

Reported-by: Antonio SJ Musumeci 
Closes: https://lore.kernel.org/all/CAOQ4uxhek5ytdN8Yz2tNEOg5ea4NkBb4nk0FGPjPk_9nz-VG3g@mail.gmail.com/
Fixes: 15db16837a35 ("fuse: fix illegal access to inode with reused nodeid")
Cc:  # v5.14
Signed-off-by: Miklos Szeredi

fuse: replace remaining make_bad_inode() with fuse_make_bad()

2024-03-05T12:40:42+00:00

fuse_do_statx() was added with the wrong helper.

Fixes: d3045530bdd2 ("fuse: implement statx")
Cc:  # v6.6
Signed-off-by: Miklos Szeredi

fuse: prepare for opening file in passthrough mode

2024-03-05T12:40:42+00:00

In preparation for opening file in passthrough mode, store the
fuse_open_out argument in ff->args to be passed into fuse_file_io_open()
with the optional backing_id member.

This will be used for setting up passthrough to backing file on open
reply with FOPEN_PASSTHROUGH flag and a valid backing_id.

Opening a file in passthrough mode may fail for several reasons, such as
missing capability, conflicting open flags or inode in caching mode.
Return EIO from fuse_file_io_open() in those cases.

The combination of FOPEN_PASSTHROUGH and FOPEN_DIRECT_IO is allowed -
it mean that read/write operations will go directly to the server,
but mmap will be done to the backing file.

Signed-off-by: Amir Goldstein 
Signed-off-by: Miklos Szeredi

fuse: prepare for failing open response

2024-02-23T16:36:32+00:00

In preparation for inode io modes, a server open response could fail due to
conflicting inode io modes.

Allow returning an error from fuse_finish_open() and handle the error in
the callers.

fuse_finish_open() is used as the callback of finish_open(), so that
FMODE_OPENED will not be set if fuse_finish_open() fails.

Signed-off-by: Amir Goldstein 
Signed-off-by: Miklos Szeredi

fuse: break up fuse_open_common()

2024-02-23T16:36:32+00:00

fuse_open_common() has a lot of code relevant only for regular files and
O_TRUNC in particular.

Copy the little bit of remaining code into fuse_dir_open() and stop using
this common helper for directory open.

Also split out fuse_dir_finish_open() from fuse_finish_open() before we add
inode io modes to fuse_finish_open().

Suggested-by: Miklos Szeredi 
Signed-off-by: Amir Goldstein 
Signed-off-by: Miklos Szeredi

fuse: allocate ff->release_args only if release is needed

2024-02-23T16:36:32+00:00

This removed the need to pass isdir argument to fuse_put_file().

Signed-off-by: Amir Goldstein 
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

Merge tag 'fuse-update-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse

2023-09-05T19:45:55+00:00

Pull fuse updates from Miklos Szeredi:

 - Revert non-waiting FLUSH due to a regression

 - Fix a lookup counter leak in readdirplus

 - Add an option to allow shared mmaps in no-cache mode

 - Add btime support and statx intrastructure to the protocol

 - Invalidate positive/negative dentry on failed create/delete

* tag 'fuse-update-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: conditionally fill kstat in fuse_do_statx()
  fuse: invalidate dentry on EEXIST creates or ENOENT deletes
  fuse: cache btime
  fuse: implement statx
  fuse: add ATTR_TIMEOUT macro
  fuse: add STATX request
  fuse: handle empty request_mask in statx
  fuse: write back dirty pages before direct write in direct_io_relax mode
  fuse: add a new fuse init flag to relax restrictions in no cache mode
  fuse: invalidate page cache pages before direct write
  fuse: nlookup missing decrement in fuse_direntplus_link
  Revert "fuse: in fuse_flush only wait if someone wants the return code"