linux-toradex.git/fs/exportfs, branch v6.9-rc4

fs: Create a generic is_dot_dotdot() utility

2024-01-23T15:58:56+00:00

De-duplicate the same functionality in several places by hoisting
the is_dot_dotdot() utility function into linux/fs.h.

Suggested-by: Amir Goldstein 
Reviewed-by: Jeff Layton 
Reviewed-by: Amir Goldstein 
Acked-by: Christian Brauner 
Signed-off-by: Chuck Lever

exportfs: fix the fallback implementation of the get_name export operation

2024-01-23T15:58:44+00:00

The fallback implementation for the get_name export operation uses
readdir() to try to match the inode number to a filename. That filename
is then used together with lookup_one() to produce a dentry.
A problem arises when we match the '.' or '..' entries, since that
causes lookup_one() to fail. This has sometimes been seen to occur for
filesystems that violate POSIX requirements around uniqueness of inode
numbers, something that is common for snapshot directories.

This patch just ensures that we skip '.' and '..' rather than allowing a
match.

Signed-off-by: Trond Myklebust 
Reviewed-by: Jeff Layton 
Acked-by: Amir Goldstein 
Link: https://lore.kernel.org/linux-nfs/CAOQ4uxiOZobN76OKB-VBNXWeFKVwLW_eK5QtthGyYzWU9mjb7Q@mail.gmail.com/
Acked-by: Christian Brauner 
Signed-off-by: Chuck Lever

fs: fix build error with CONFIG_EXPORTFS=m or not defined

2023-10-28T14:16:19+00:00

Many of the filesystems that call the generic exportfs helpers do not
select the EXPORTFS config.

Move generic_encode_ino32_fh() to libfs.c, same as generic_fh_to_*()
to avoid having to fix all those config dependencies.

Reported-by: kernel test robot 
Closes: https://lore.kernel.org/oe-kbuild-all/202310262151.renqMvme-lkp@intel.com/
Fixes: dfaf653dc415 ("exportfs: make ->encode_fh() a mandatory method for NFS export")
Suggested-by: Arnd Bergmann 
Signed-off-by: Amir Goldstein 
Link: https://lore.kernel.org/r/20231026204540.143217-1-amir73il@gmail.com
Tested-by: Arnd Bergmann 
Signed-off-by: Christian Brauner

exportfs: support encoding non-decodeable file handles by default

2023-10-28T14:16:18+00:00

AT_HANDLE_FID was added as an API for name_to_handle_at() that request
the encoding of a file id, which is not intended to be decoded.

This file id is used by fanotify to describe objects in events.

So far, overlayfs is the only filesystem that supports encoding
non-decodeable file ids, by providing export_operations with an
->encode_fh() method and without a ->decode_fh() method.

Add support for encoding non-decodeable file ids to all the filesystems
that do not provide export_operations, by encoding a file id of type
FILEID_INO64_GEN from { i_ino, i_generation }.

A filesystem may that does not support NFS export, can opt-out of
encoding non-decodeable file ids for fanotify by defining an empty
export_operations struct (i.e. with a NULL ->encode_fh() method).

This allows the use of fanotify events with file ids on filesystems
like 9p which do not support NFS export to bring fanotify in feature
parity with inotify on those filesystems.

Note that fanotify also requires that the filesystems report a non-null
fsid.  Currently, many simple filesystems that have support for inotify
(e.g. debugfs, tracefs, sysfs) report a null fsid, so can still not be
used with fanotify in file id reporting mode.

Reviewed-by: Jan Kara 
Reviewed-by: Jeff Layton 
Signed-off-by: Amir Goldstein 
Link: https://lore.kernel.org/r/20231023180801.2953446-5-amir73il@gmail.com
Signed-off-by: Christian Brauner

exportfs: make ->encode_fh() a mandatory method for NFS export

2023-10-28T14:15:15+00:00

Rename the default helper for encoding FILEID_INO32_GEN* file handles to
generic_encode_ino32_fh() and convert the filesystems that used the
default implementation to use the generic helper explicitly.

After this change, exportfs_encode_inode_fh() no longer has a default
implementation to encode FILEID_INO32_GEN* file handles.

This is a step towards allowing filesystems to encode non-decodeable
file handles for fanotify without having to implement any
export_operations.

Reviewed-by: Jan Kara 
Reviewed-by: Jeff Layton 
Acked-by: Chuck Lever 
Signed-off-by: Amir Goldstein 
Link: https://lore.kernel.org/r/20231023180801.2953446-3-amir73il@gmail.com
Acked-by: Dave Kleikamp 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Christian Brauner

exportfs: add helpers to check if filesystem can encode/decode file handles

2023-10-24T15:57:45+00:00

The logic of whether filesystem can encode/decode file handles is open
coded in many places.

In preparation to changing the logic, move the open coded logic into
inline helpers.

Reviewed-by: Jan Kara 
Reviewed-by: Jeff Layton 
Signed-off-by: Amir Goldstein 
Link: https://lore.kernel.org/r/20231023180801.2953446-2-amir73il@gmail.com
Signed-off-by: Christian Brauner

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>