linux.git/fs/fuse/control.c, branch v5.4

convenience helper: get_tree_single()

2019-07-05T02:01:58+00:00

counterpart of mount_single(); switch fusectl to it

Signed-off-by: Al Viro

fuse: Convert fusectl to use the new mount API

2019-04-24T15:05:07+00:00

Convert the fusectl filesystem to the new internal mount API as the old
one will be obsoleted and removed.  This allows greater flexibility in
communication of mount parameters between userspace, the VFS and the
filesystem.

See Documentation/filesystems/mount_api.txt for more information.

Signed-off-by: David Howells 
Signed-off-by: Miklos Szeredi

fuse: clean up aborted

2019-02-13T12:15:14+00:00

The only caller that needs fc->aborted set is fuse_conn_abort_write().
Setting fc->aborted is now racy (fuse_abort_conn() may already be in
progress or finished) but there's no reason to care.

Signed-off-by: Miklos Szeredi

fuse: introduce fc->bg_lock

2018-09-28T14:43:22+00:00

To reduce contention of fc->lock, this patch introduces bg_lock for
protection of fields related to background queue. These are:
max_background, congestion_threshold, num_background, active_background,
bg_queue and blocked.

This allows next patch to make async reads not requiring fc->lock, so async
reads and writes will have better performance executed in parallel.

Signed-off-by: Kirill Tkhai 
Signed-off-by: Miklos Szeredi

fuse: add locking to max_background and congestion_threshold changes

2018-09-28T14:43:22+00:00

Functions sequences like request_end()->flush_bg_queue() require that
max_background and congestion_threshold are constant during their
execution. Otherwise, checks like

	if (fc->num_background == fc->max_background)

made in different time may behave not like expected.

Signed-off-by: Kirill Tkhai 
Signed-off-by: Miklos Szeredi

fuse: use READ_ONCE on congestion_threshold and max_background

2018-09-28T14:43:22+00:00

Since they are of unsigned int type, it's allowed to read them
unlocked during reporting to userspace. Let's underline this fact
with READ_ONCE() macroses.

Signed-off-by: Kirill Tkhai 
Signed-off-by: Miklos Szeredi

fuse: fix control dir setup and teardown

2018-05-31T10:26:10+00:00

syzbot is reporting NULL pointer dereference at fuse_ctl_remove_conn() [1].
Since fc->ctl_ndents is incremented by fuse_ctl_add_conn() when new_inode()
failed, fuse_ctl_remove_conn() reaches an inode-less dentry and tries to
clear d_inode(dentry)->i_private field.

Fix by only adding the dentry to the array after being fully set up.

When tearing down the control directory, do d_invalidate() on it to get rid
of any mounts that might have been added.

[1] https://syzkaller.appspot.com/bug?id=f396d863067238959c91c0b7cfc10b163638cac6
Reported-by: syzbot 
Fixes: bafa96541b25 ("[PATCH] fuse: add control filesystem")
Cc:  # v2.6.18
Signed-off-by: Miklos Szeredi

fuse: return -ECONNABORTED on /dev/fuse read after abort

2018-03-20T16:11:44+00:00

Currently the userspace has no way of knowing whether the fuse
connection ended because of umount or abort via sysfs. It makes it hard
for filesystems to free the mountpoint after abort without worrying
about removing some new mount.

The patch fixes it by returning different errors when userspace reads
from /dev/fuse (-ENODEV for umount and -ECONNABORTED for abort).

Add a new capability flag FUSE_ABORT_ERROR. If set and the connection is
gone because of sysfs abort, reading from the device will return
-ECONNABORTED.

Signed-off-by: Szymon Lukasz 
Signed-off-by: Miklos Szeredi

fs: constify tree_descr arrays passed to simple_fill_super()

2017-04-27T03:54:06+00:00

simple_fill_super() is passed an array of tree_descr structures which
describe the files to create in the filesystem's root directory.  Since
these arrays are never modified intentionally, they should be 'const' so
that they are placed in .rodata and benefit from memory protection.
This patch updates the function signature and all users, and also
constifies tree_descr.name.

Signed-off-by: Eric Biggers 
Signed-off-by: Al Viro

fs: Replace CURRENT_TIME with current_time() for inode timestamps

2016-09-28T01:06:21+00:00

CURRENT_TIME macro is not appropriate for filesystems as it
doesn't use the right granularity for filesystem timestamps.
Use current_time() instead.

CURRENT_TIME is also not y2038 safe.

This is also in preparation for the patch that transitions
vfs timestamps to use 64 bit time and hence make them
y2038 safe. As part of the effort current_time() will be
extended to do range checks. Hence, it is necessary for all
file system timestamps to use current_time(). Also,
current_time() will be transitioned along with vfs to be
y2038 safe.

Note that whenever a single call to current_time() is used
to change timestamps in different inodes, it is because they
share the same time granularity.

Signed-off-by: Deepa Dinamani 
Reviewed-by: Arnd Bergmann 
Acked-by: Felipe Balbi 
Acked-by: Steven Whitehouse 
Acked-by: Ryusuke Konishi 
Acked-by: David Sterba 
Signed-off-by: Al Viro