linux.git/fs/exportfs, branch v6.6.131

exportfs: remove kernel-doc warnings in exportfs

2023-08-29T21:45:22+00:00

Remove kernel-doc warning in exportfs:

fs/exportfs/expfs.c:395: warning: Function parameter or member 'parent'
not described in 'exportfs_encode_inode_fh'

Signed-off-by: Zhu Wang 
Signed-off-by: Chuck Lever

vfs: get rid of old '->iterate' directory operation

2023-08-06T13:08:35+00:00

All users now just use '->iterate_shared()', which only takes the
directory inode lock for reading.

Filesystems that never got convered to shared mode now instead use a
wrapper that drops the lock, re-takes it in write mode, calls the old
function, and then downgrades the lock back to read mode.

This way the VFS layer and other callers no longer need to care about
filesystems that never got converted to the modern era.

The filesystems that use the new wrapper are ceph, coda, exfat, jfs,
ntfs, ocfs2, overlayfs, and vboxsf.

Honestly, several of them look like they really could just iterate their
directories in shared mode and skip the wrapper entirely, but the point
of this change is to not change semantics or fix filesystems that
haven't been fixed in the last 7+ years, but to finally get rid of the
dual iterators.

Signed-off-by: Linus Torvalds 
Signed-off-by: Christian Brauner

exportfs: add explicit flag to request non-decodeable file handles

2023-05-22T16:08:37+00:00

So far, all callers of exportfs_encode_inode_fh(), except for fsnotify's
show_mark_fhandle(), check that filesystem can decode file handles, but
we would like to add more callers that do not require a file handle that
can be decoded.

Introduce a flag to explicitly request a file handle that may not to be
decoded later and a wrapper exportfs_encode_fid() that sets this flag
and convert show_mark_fhandle() to use the new wrapper.

This will be used to allow adding fanotify support to filesystems that
do not support NFS export.

Acked-by: Jeff Layton 
Acked-by: Chuck Lever 
Signed-off-by: Amir Goldstein 
Signed-off-by: Jan Kara 
Message-Id: <20230502124817.3070545-3-amir73il@gmail.com>

exportfs: change connectable argument to bit flags

2023-05-22T16:08:37+00:00

Convert the bool connectable arguemnt into a bit flags argument and
define the EXPORT_FS_CONNECTABLE flag as a requested property of the
file handle.

We are going to add a flag for requesting non-decodeable file handles.

Acked-by: Jeff Layton 
Acked-by: Chuck Lever 
Signed-off-by: Amir Goldstein 
Signed-off-by: Jan Kara 
Message-Id: <20230502124817.3070545-2-amir73il@gmail.com>

fs: port ->permission() to pass mnt_idmap

2023-01-19T08:24:28+00:00

Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Christian Brauner (Microsoft)

exportfs: use pr_debug for unreachable debug statements

2022-11-28T17:54:45+00:00

expfs.c has a bunch of dprintk statements which are unusable due to:
 #define dprintk(fmt, args...) do{}while(0)
Use pr_debug so that they can be enabled dynamically.
Also make some minor changes to the debug statements to fix some
incorrect types, and remove __func__ which can be handled by dynamic
debug separately.

Signed-off-by: David Disseldorp 
Reviewed-by: NeilBrown 
Signed-off-by: Chuck Lever

Change calling conventions for filldir_t

2022-08-17T21:25:04+00:00

filldir_t instances (directory iterators callbacks) used to return 0 for
"OK, keep going" or -E... for "stop".  Note that it's *NOT* how the
error values are reported - the rules for those are callback-dependent
and ->iterate{,_shared}() instances only care about zero vs. non-zero
(look at emit_dir() and friends).

So let's just return bool ("should we keep going?") - it's less confusing
that way.  The choice between "true means keep going" and "true means
stop" is bikesheddable; we have two groups of callbacks -
	do something for everything in directory, until we run into problem
and
	find an entry in directory and do something to it.

The former tended to use 0/-E... conventions - -E on failure.
The latter tended to use 0/1, 1 being "stop, we are done".
The callers treated anything non-zero as "stop", ignoring which
non-zero value did they get.

"true means stop" would be more natural for the second group; "true
means keep going" - for the first one.  I tried both variants and
the things like
	if allocation failed
		something = -ENOMEM;
		return true;
just looked unnatural and asking for trouble.

[folded suggestion from Matthew Wilcox ]
Acked-by: Christian Brauner (Microsoft) 
Signed-off-by: Al Viro

exportfs: support idmapped mounts

2022-04-28T14:31:10+00:00

Make the two locations where exportfs helpers check permission to lookup
a given inode idmapped mount aware by switching it to the lookup_one()
helper. This is a bugfix for the open_by_handle_at() system call which
doesn't take idmapped mounts into account currently. It's not tied to a
specific commit so we'll just Cc stable.

In addition this is required to support idmapped base layers in overlay.
The overlay filesystem uses exportfs to encode and decode file handles
for its index=on mount option and when nfs_export=on.

Cc: 
Cc: 
Tested-by: Giuseppe Scrivano 
Reviewed-by: Amir Goldstein 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Christian Brauner (Microsoft) 
Signed-off-by: Miklos Szeredi

exportfs: Add a function to return the raw output from fh_to_dentry()

2020-12-09T14:39:38+00:00

In order to allow nfsd to accept return values that are not
acceptable to overlayfs and others, add a new function.

Signed-off-by: Trond Myklebust 
Signed-off-by: Chuck Lever

exportfs_decode_fh(): negative pinned may become positive without the parent locked

2019-11-10T16:56:05+00:00

Signed-off-by: Al Viro