Commit Graph

68 Commits

Author SHA1 Message Date
Linus Torvalds ecd7db2047 v6.6-vfs.tmpfs
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Merge tag 'v6.6-vfs.tmpfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull libfs and tmpfs updates from Christian Brauner:
 "This cycle saw a lot of work for tmpfs that required changes to the
  vfs layer. Andrew, Hugh, and I decided to take tmpfs through vfs this
  cycle. Things will go back to mm next cycle.

  Features
  ========

   - By far the biggest work is the quota support for tmpfs. New tmpfs
     quota infrastructure is added to support it and a new QFMT_SHMEM
     uapi option is exposed.

     This offers user and group quotas to tmpfs (project quotas will be
     added later). Similar to other filesystems tmpfs quota are not
     supported within user namespaces yet.

   - Add support for user xattrs. While tmpfs already supports security
     xattrs (security.*) and POSIX ACLs for a long time it lacked
     support for user xattrs (user.*). With this pull request tmpfs will
     be able to support a limited number of user xattrs.

     This is accompanied by a fix (see below) to limit persistent simple
     xattr allocations.

   - Add support for stable directory offsets. Currently tmpfs relies on
     the libfs provided cursor-based mechanism for readdir. This causes
     issues when a tmpfs filesystem is exported via NFS.

     NFS clients do not open directories. Instead, each server-side
     readdir operation opens the directory, reads it, and then closes
     it. Since the cursor state for that directory is associated with
     the opened file it is discarded after each readdir operation. Such
     directory offsets are not just cached by NFS clients but also
     various userspace libraries based on these clients.

     As it stands there is no way to invalidate the caches when
     directory offsets have changed and the whole application depends on
     unchanging directory offsets.

     At LSFMM we discussed how to solve this problem and decided to
     support stable directory offsets. libfs now allows filesystems like
     tmpfs to use an xarrary to map a directory offset to a dentry. This
     mechanism is currently only used by tmpfs but can be supported by
     others as well.

  Fixes
  =====

   - Change persistent simple xattrs allocations in libfs from
     GFP_KERNEL to GPF_KERNEL_ACCOUNT so they're subject to memory
     cgroup limits. Since this is a change to libfs it affects both
     tmpfs and kernfs.

   - Correctly verify {g,u}id mount options.

     A new filesystem context is created via fsopen() which records the
     namespace that becomes the owning namespace of the superblock when
     fsconfig(FSCONFIG_CMD_CREATE) is called for filesystems that are
     mountable in namespaces. However, fsconfig() calls can occur in a
     namespace different from the namespace where fsopen() has been
     called.

     Currently, when fsconfig() is called to set {g,u}id mount options
     the requested {g,u}id is mapped into a k{g,u}id according to the
     namespace where fsconfig() was called from. The resulting k{g,u}id
     is not guaranteed to be resolvable in the namespace of the
     filesystem (the one that fsopen() was called in).

     This means it's possible for an unprivileged user to create files
     owned by any group in a tmpfs mount since it's possible to set the
     setid bits on the tmpfs directory.

     The contract for {g,u}id mount options and {g,u}id values in
     general set from userspace has always been that they are translated
     according to the caller's idmapping. In so far, tmpfs has been
     doing the correct thing. But since tmpfs is mountable in
     unprivileged contexts it is also necessary to verify that the
     resulting {k,g}uid is representable in the namespace of the
     superblock to avoid such bugs.

     The new mount api's cross-namespace delegation abilities are
     already widely used. Having talked to a bunch of userspace this is
     the most faithful solution with minimal regression risks"

* tag 'v6.6-vfs.tmpfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  tmpfs,xattr: GFP_KERNEL_ACCOUNT for simple xattrs
  mm: invalidation check mapping before folio_contains
  tmpfs: trivial support for direct IO
  tmpfs,xattr: enable limited user extended attributes
  tmpfs: track free_ispace instead of free_inodes
  xattr: simple_xattr_set() return old_xattr to be freed
  tmpfs: verify {g,u}id mount options correctly
  shmem: move spinlock into shmem_recalc_inode() to fix quota support
  libfs: Remove parent dentry locking in offset_iterate_dir()
  libfs: Add a lock class for the offset map's xa_lock
  shmem: stable directory offsets
  shmem: Refactor shmem_symlink()
  libfs: Add directory operations for stable offsets
  shmem: fix quota lock nesting in huge hole handling
  shmem: Add default quota limit mount options
  shmem: quota support
  shmem: prepare shmem quota infrastructure
  quota: Check presence of quota operation structures instead of ->quota_read and ->quota_write callbacks
  shmem: make shmem_get_inode() return ERR_PTR instead of NULL
  shmem: make shmem_inode_acct_block() return error
2023-08-28 09:55:25 -07:00
Hugh Dickins 5de75970c9 xattr: simple_xattr_set() return old_xattr to be freed
tmpfs wants to support limited user extended attributes, but kernfs
(or cgroupfs, the only kernfs with KERNFS_ROOT_SUPPORT_USER_XATTR)
already supports user extended attributes through simple xattrs: but
limited by a policy (128KiB per inode) too liberal to be used on tmpfs.

To allow a different limiting policy for tmpfs, without affecting the
policy for kernfs, change simple_xattr_set() to return the replaced or
removed xattr (if any), leaving the caller to update their accounting
then free the xattr (by simple_xattr_free(), renamed from the static
free_simple_xattr()).

Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Message-Id: <158c6585-2aa7-d4aa-90ff-f7c3f8fe407c@google.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-09 09:15:51 +02:00
Jeff Layton 0d72b92883 fs: pass the request_mask to generic_fillattr
generic_fillattr just fills in the entire stat struct indiscriminately
today, copying data from the inode. There is at least one attribute
(STATX_CHANGE_COOKIE) that can have side effects when it is reported,
and we're looking at adding more with the addition of multigrain
timestamps.

Add a request_mask argument to generic_fillattr and have most callers
just pass in the value that is passed to getattr. Have other callers
(e.g. ksmbd) just pass in STATX_BASIC_STATS. Also move the setting of
STATX_CHANGE_COOKIE into generic_fillattr.

Acked-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Reviewed-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: "Paulo Alcantara (SUSE)" <pc@manguebit.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Message-Id: <20230807-mgctime-v7-2-d1dec143a704@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-09 08:56:36 +02:00
Jeff Layton f7f438589f kernfs: convert to ctime accessor functions
In later patches, we're going to change how the inode's ctime field is
used. Switch to using accessor functions instead of raw accesses of
inode->i_ctime.

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Message-Id: <20230705190309.579783-54-jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-07-24 10:30:01 +02:00
Imran Khan 9caf696142 kernfs: Introduce separate rwsem to protect inode attributes.
Right now a global per-fs rwsem (kernfs_rwsem) synchronizes multiple
kernfs operations. On a large system with few hundred CPUs and few
hundred applications simultaneoulsy trying to access sysfs, this
results in multiple sys_open(s) contending on kernfs_rwsem via
kernfs_iop_permission and kernfs_dop_revalidate.

For example on a system with 384 cores, if I run 200 instances of an
application which is mostly executing the following loop:

  for (int loop = 0; loop <100 ; loop++)
  {
    for (int port_num = 1; port_num < 2; port_num++)
    {
      for (int gid_index = 0; gid_index < 254; gid_index++ )
      {
        char ret_buf[64], ret_buf_lo[64];
        char gid_file_path[1024];

        int      ret_len;
        int      ret_fd;
        ssize_t  ret_rd;

        ub4  i, saved_errno;

        memset(ret_buf, 0, sizeof(ret_buf));
        memset(gid_file_path, 0, sizeof(gid_file_path));

        ret_len = snprintf(gid_file_path, sizeof(gid_file_path),
                           "/sys/class/infiniband/%s/ports/%d/gids/%d",
                           dev_name,
                           port_num,
                           gid_index);

        ret_fd = open(gid_file_path, O_RDONLY | O_CLOEXEC);
        if (ret_fd < 0)
        {
          printf("Failed to open %s\n", gid_file_path);
          continue;
        }

        /* Read the GID */
        ret_rd = read(ret_fd, ret_buf, 40);

        if (ret_rd == -1)
        {
          printf("Failed to read from file %s, errno: %u\n",
                 gid_file_path, saved_errno);

          continue;
        }

        close(ret_fd);
      }
    }

I see contention around kernfs_rwsem as follows:

path_openat
|
|----link_path_walk.part.0.constprop.0
|      |
|      |--49.92%--inode_permission
|      |          |
|      |           --48.69%--kernfs_iop_permission
|      |                     |
|      |                     |--18.16%--down_read
|      |                     |
|      |                     |--15.38%--up_read
|      |                     |
|      |                      --14.58%--_raw_spin_lock
|      |                                |
|      |                                 -----
|      |
|      |--29.08%--walk_component
|      |          |
|      |           --29.02%--lookup_fast
|      |                     |
|      |                     |--24.26%--kernfs_dop_revalidate
|      |                     |          |
|      |                     |          |--14.97%--down_read
|      |                     |          |
|      |                     |           --9.01%--up_read
|      |                     |
|      |                      --4.74%--__d_lookup
|      |                                |
|      |                                 --4.64%--_raw_spin_lock
|      |                                           |
|      |                                            ----

Having a separate per-fs rwsem to protect kernfs inode attributes,
will avoid the above mentioned contention and result in better
performance as can bee seen below:

path_openat
|
|----link_path_walk.part.0.constprop.0
|     |
|     |
|     |--27.06%--inode_permission
|     |          |
|     |           --25.84%--kernfs_iop_permission
|     |                     |
|     |                     |--9.29%--up_read
|     |                     |
|     |                     |--8.19%--down_read
|     |                     |
|     |                      --7.89%--_raw_spin_lock
|     |                                |
|     |                                 ----
|     |
|     |--22.42%--walk_component
|     |          |
|     |           --22.36%--lookup_fast
|     |                     |
|     |                     |--16.07%--__d_lookup
|     |                     |          |
|     |                     |           --16.01%--_raw_spin_lock
|     |                     |                     |
|     |                     |                      ----
|     |                     |
|     |                      --6.28%--kernfs_dop_revalidate
|     |                                |
|     |                                |--3.76%--down_read
|     |                                |
|     |                                 --2.26%--up_read

As can be seen from the above data the overhead due to both
kerfs_iop_permission and kernfs_dop_revalidate have gone down and
this also reduces overall run time of the earlier mentioned loop.

Signed-off-by: Imran Khan <imran.f.khan@oracle.com>
Link: https://lore.kernel.org/r/20230309110932.2889010-2-imran.f.khan@oracle.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-29 12:23:45 +02:00
Christian Brauner 39f60c1cce
fs: port xattr to mnt_idmap
Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b ("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 <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-19 09:24:28 +01:00
Christian Brauner 4609e1f18e
fs: port ->permission() to pass mnt_idmap
Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b ("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 <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-19 09:24:28 +01:00
Christian Brauner b74d24f7a7
fs: port ->getattr() to pass mnt_idmap
Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b ("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 <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-19 09:24:25 +01:00
Christian Brauner c1632a0f11
fs: port ->setattr() to pass mnt_idmap
Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b ("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 <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-19 09:24:02 +01:00
Randy Dunlap 24b3e3dd9c kernfs: fix all kernel-doc warnings and multiple typos
Fix kernel-doc warnings. Many of these are about a function's
return value, so use the kernel-doc Return: format to fix those

Use % prefix on numeric constant values.

dir.c: fix typos/spellos
file.c fix typo: s/taret/target/

Fix all of these kernel-doc warnings:

dir.c:305: warning: missing initial short description on line:
 *      kernfs_name_hash

dir.c:137: warning: No description found for return value of 'kernfs_path_from_node_locked'
dir.c:196: warning: No description found for return value of 'kernfs_name'
dir.c:224: warning: No description found for return value of 'kernfs_path_from_node'
dir.c:292: warning: No description found for return value of 'kernfs_get_parent'
dir.c:312: warning: No description found for return value of 'kernfs_name_hash'
dir.c:404: warning: No description found for return value of 'kernfs_unlink_sibling'
dir.c:588: warning: No description found for return value of 'kernfs_node_from_dentry'
dir.c:806: warning: No description found for return value of 'kernfs_find_ns'
dir.c:879: warning: No description found for return value of 'kernfs_find_and_get_ns'
dir.c:904: warning: No description found for return value of 'kernfs_walk_and_get_ns'
dir.c:927: warning: No description found for return value of 'kernfs_create_root'
dir.c:996: warning: No description found for return value of 'kernfs_root_to_node'
dir.c:1016: warning: No description found for return value of 'kernfs_create_dir_ns'
dir.c:1048: warning: No description found for return value of 'kernfs_create_empty_dir'
dir.c:1306: warning: No description found for return value of 'kernfs_next_descendant_post'
dir.c:1568: warning: No description found for return value of 'kernfs_remove_self'
dir.c:1630: warning: No description found for return value of 'kernfs_remove_by_name_ns'
dir.c:1667: warning: No description found for return value of 'kernfs_rename_ns'

file.c:66: warning: No description found for return value of 'of_on'
file.c:88: warning: No description found for return value of 'kernfs_deref_open_node_locked'
file.c:1036: warning: No description found for return value of '__kernfs_create_file'

inode.c💯 warning: No description found for return value of 'kernfs_setattr'

mount.c:160: warning: No description found for return value of 'kernfs_root_from_sb'
mount.c:198: warning: No description found for return value of 'kernfs_node_dentry'
mount.c:302: warning: No description found for return value of 'kernfs_super_ns'
mount.c:318: warning: No description found for return value of 'kernfs_get_tree'

symlink.c:28: warning: No description found for return value of 'kernfs_create_link'

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Tejun Heo <tj@kernel.org>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20221112031456.22980-1-rdunlap@infradead.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-23 19:28:26 +01:00
Ian Kent aa1d058d48 kernfs: dont take i_lock on inode attr read
The kernfs write lock is held when the kernfs node inode attributes
are updated. Therefore, when either kernfs_iop_getattr() or
kernfs_iop_permission() are called the kernfs node inode attributes
won't change.

Consequently concurrent kernfs_refresh_inode() calls always copy the
same values from the kernfs node.

So there's no need to take the inode i_lock to get consistent values
for generic_fillattr() and generic_permission(), the kernfs read lock
is sufficient.

Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Ian Kent <raven@themaw.net>
Link: https://lore.kernel.org/r/166606036215.13363.1288735296954908554.stgit@donald.themaw.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-20 13:54:26 +02:00
Minchan Kim 393c371408 kernfs: switch global kernfs_rwsem lock to per-fs lock
The kernfs implementation has big lock granularity(kernfs_rwsem) so
every kernfs-based(e.g., sysfs, cgroup) fs are able to compete the
lock. It makes trouble for some cases to wait the global lock
for a long time even though they are totally independent contexts
each other.

A general example is process A goes under direct reclaim with holding
the lock when it accessed the file in sysfs and process B is waiting
the lock with exclusive mode and then process C is waiting the lock
until process B could finish the job after it gets the lock from
process A.

This patch switches the global kernfs_rwsem to per-fs lock, which
put the rwsem into kernfs_root.

Suggested-by: Tejun Heo <tj@kernel.org>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Minchan Kim <minchan@kernel.org>
Link: https://lore.kernel.org/r/20211118230008.2679780-1-minchan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-24 13:55:16 +01:00
Ian Kent 47b5c64d0a kernfs: use i_lock to protect concurrent inode updates
The inode operations .permission() and .getattr() use the kernfs node
write lock but all that's needed is the read lock to protect against
partial updates of these kernfs node fields which are all done under
the write lock.

And .permission() is called frequently during path walks and can cause
quite a bit of contention between kernfs node operations and path
walks when the number of concurrent walks is high.

To change kernfs_iop_getattr() and kernfs_iop_permission() to take
the rw sem read lock instead of the write lock an additional lock is
needed to protect against multiple processes concurrently updating
the inode attributes and link count in kernfs_refresh_inode().

The inode i_lock seems like the sensible thing to use to protect these
inode attribute updates so use it in kernfs_refresh_inode().

The last hunk in the patch, applied to kernfs_fill_super(), is possibly
not needed but taking the lock was present originally. I prefer to
continue to take it to protect against a partial update of the source
kernfs fields during the call to kernfs_refresh_inode() made by
kernfs_get_inode().

Reviewed-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Ian Kent <raven@themaw.net>
Link: https://lore.kernel.org/r/162642771474.63632.16295959115893904470.stgit@web.messagingengine.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-27 09:29:15 +02:00
Ian Kent 7ba0273b2f kernfs: switch kernfs to use an rwsem
The kernfs global lock restricts the ability to perform kernfs node
lookup operations in parallel during path walks.

Change the kernfs mutex to an rwsem so that, when opportunity arises,
node searches can be done in parallel with path walk lookups.

Reviewed-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Ian Kent <raven@themaw.net>
Link: https://lore.kernel.org/r/162642770946.63632.2218304587223241374.stgit@web.messagingengine.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-27 09:29:15 +02:00
Christoph Hellwig c1e3dbe981 fs: move ramfs_aops to libfs
Move the ramfs aops to libfs and reuse them for kernfs and configfs.
Thosw two did not wire up ->set_page_dirty before and now get
__set_page_dirty_no_writeback, which is the right one for no-writeback
address_space usage.

Drop the now unused exports of the libfs helpers only used for ramfs-style
pagecache usage.

Link: https://lkml.kernel.org/r/20210614061512.3966143-3-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:48 -07:00
Christian Brauner 549c729771
fs: make helpers idmap mount aware
Extend some inode methods with an additional user namespace argument. A
filesystem that is aware of idmapped mounts will receive the user
namespace the mount has been marked with. This can be used for
additional permission checking and also to enable filesystems to
translate between uids and gids if they need to. We have implemented all
relevant helpers in earlier patches.

As requested we simply extend the exisiting inode method instead of
introducing new ones. This is a little more code churn but it's mostly
mechanical and doesnt't leave us with additional inode methods.

Link: https://lore.kernel.org/r/20210121131959.646623-25-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-01-24 14:27:20 +01:00
Christian Brauner 0d56a4518d
stat: handle idmapped mounts
The generic_fillattr() helper fills in the basic attributes associated
with an inode. Enable it to handle idmapped mounts. If the inode is
accessed through an idmapped mount map it into the mount's user
namespace before we store the uid and gid. If the initial user namespace
is passed nothing changes so non-idmapped mounts will see identical
behavior as before.

Link: https://lore.kernel.org/r/20210121131959.646623-12-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-01-24 14:27:17 +01:00
Christian Brauner e65ce2a50c
acl: handle idmapped mounts
The posix acl permission checking helpers determine whether a caller is
privileged over an inode according to the acls associated with the
inode. Add helpers that make it possible to handle acls on idmapped
mounts.

The vfs and the filesystems targeted by this first iteration make use of
posix_acl_fix_xattr_from_user() and posix_acl_fix_xattr_to_user() to
translate basic posix access and default permissions such as the
ACL_USER and ACL_GROUP type according to the initial user namespace (or
the superblock's user namespace) to and from the caller's current user
namespace. Adapt these two helpers to handle idmapped mounts whereby we
either map from or into the mount's user namespace depending on in which
direction we're translating.
Similarly, cap_convert_nscap() is used by the vfs to translate user
namespace and non-user namespace aware filesystem capabilities from the
superblock's user namespace to the caller's user namespace. Enable it to
handle idmapped mounts by accounting for the mount's user namespace.

In addition the fileystems targeted in the first iteration of this patch
series make use of the posix_acl_chmod() and, posix_acl_update_mode()
helpers. Both helpers perform permission checks on the target inode. Let
them handle idmapped mounts. These two helpers are called when posix
acls are set by the respective filesystems to handle this case we extend
the ->set() method to take an additional user namespace argument to pass
the mount's user namespace down.

Link: https://lore.kernel.org/r/20210121131959.646623-9-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-01-24 14:27:17 +01:00
Christian Brauner 2f221d6f7b
attr: handle idmapped mounts
When file attributes are changed most filesystems rely on the
setattr_prepare(), setattr_copy(), and notify_change() helpers for
initialization and permission checking. Let them handle idmapped mounts.
If the inode is accessed through an idmapped mount map it into the
mount's user namespace. Afterwards the checks are identical to
non-idmapped mounts. If the initial user namespace is passed nothing
changes so non-idmapped mounts will see identical behavior as before.

Helpers that perform checks on the ia_uid and ia_gid fields in struct
iattr assume that ia_uid and ia_gid are intended values and have already
been mapped correctly at the userspace-kernelspace boundary as we
already do today. If the initial user namespace is passed nothing
changes so non-idmapped mounts will see identical behavior as before.

Link: https://lore.kernel.org/r/20210121131959.646623-8-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-01-24 14:27:16 +01:00
Christian Brauner 47291baa8d
namei: make permission helpers idmapped mount aware
The two helpers inode_permission() and generic_permission() are used by
the vfs to perform basic permission checking by verifying that the
caller is privileged over an inode. In order to handle idmapped mounts
we extend the two helpers with an additional user namespace argument.
On idmapped mounts the two helpers will make sure to map the inode
according to the mount's user namespace and then peform identical
permission checks to inode_permission() and generic_permission(). If the
initial user namespace is passed nothing changes so non-idmapped mounts
will see identical behavior as before.

Link: https://lore.kernel.org/r/20210121131959.646623-6-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-01-24 14:27:16 +01:00
Daniel Xu 0c47383ba3 kernfs: Add option to enable user xattrs
User extended attributes are useful as metadata storage for kernfs
consumers like cgroups. Especially in the case of cgroups, it is useful
to have a central metadata store that multiple processes/services can
use to coordinate actions.

A concrete example is for userspace out of memory killers. We want to
let delegated cgroup subtree owners (running as non-root) to be able to
say "please avoid killing this cgroup". This is especially important for
desktop linux as delegated subtrees owners are less likely to run as
root.

This patch introduces a new flag, KERNFS_ROOT_SUPPORT_USER_XATTR, that
lets kernfs consumers enable user xattr support. An initial limit of 128
entries or 128KB -- whichever is hit first -- is placed per cgroup
because xattrs come from kernel memory and we don't want to let
unprivileged users accidentally eat up too much kernel memory.

Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Acked-by: Chris Down <chris@chrisdown.name>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2020-03-16 15:53:47 -04:00
Daniel Xu a46a22955b kernfs: Add removed_size out param for simple_xattr_set
This helps set up size accounting in the next commit. Without this out
param, it's difficult to find out the removed xattr size without taking
a lock for longer and walking the xattr linked list twice.

Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Acked-by: Chris Down <chris@chrisdown.name>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2020-03-16 15:53:47 -04:00
Al Viro f0f3588f7a kernfs: don't bother with timestamp truncation
kernfs users are not going to have limited
range or granularity anyway.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-12-08 19:10:57 -05:00
Tejun Heo 67c0496e87 kernfs: convert kernfs_node->id from union kernfs_node_id to u64
kernfs_node->id is currently a union kernfs_node_id which represents
either a 32bit (ino, gen) pair or u64 value.  I can't see much value
in the usage of the union - all that's needed is a 64bit ID which the
current code is already limited to.  Using a union makes the code
unnecessarily complicated and prevents using 64bit ino without adding
practical benefits.

This patch drops union kernfs_node_id and makes kernfs_node->id a u64.
ino is stored in the lower 32bits and gen upper.  Accessors -
kernfs[_id]_ino() and kernfs[_id]_gen() - are added to retrieve the
ino and gen.  This simplifies ID handling less cumbersome and will
allow using 64bit inos on supported archs.

This patch doesn't make any functional changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Alexei Starovoitov <ast@kernel.org>
2019-11-12 08:18:03 -08:00
Deepa Dinamani 3818c1907a timestamp_truncate: Replace users of timespec64_trunc
Update the inode timestamp updates to use timestamp_truncate()
instead of timespec64_trunc().

The change was mostly generated by the following coccinelle
script.

virtual context
virtual patch

@r1 depends on patch forall@
struct inode *inode;
identifier i_xtime =~ "^i_[acm]time$";
expression e;
@@

inode->i_xtime =
- timespec64_trunc(
+ timestamp_truncate(
...,
- e);
+ inode);

Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Jeff Layton <jlayton@kernel.org>
Cc: adrian.hunter@intel.com
Cc: dedekind1@gmail.com
Cc: gregkh@linuxfoundation.org
Cc: hch@lst.de
Cc: jaegeuk@kernel.org
Cc: jlbec@evilplan.org
Cc: richard@nod.at
Cc: tj@kernel.org
Cc: yuchao0@huawei.com
Cc: linux-f2fs-devel@lists.sourceforge.net
Cc: linux-ntfs-dev@lists.sourceforge.net
Cc: linux-mtd@lists.infradead.org
2019-08-30 07:27:17 -07:00
Thomas Gleixner 55716d2643 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428
Based on 1 normalized pattern(s):

  this file is released under the gplv2

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 68 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Armijn Hemel <armijn@tjaldur.nl>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531190114.292346262@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-05 17:37:16 +02:00
Ondrej Mosnacek 1537ad15c9 kernfs: fix xattr name handling in LSM helpers
The implementation of kernfs_security_xattr_*() helpers reuses the
kernfs_node_xattr_*() functions, which take the suffix of the xattr name
and extract full xattr name from it using xattr_full_name(). However,
this function relies on the fact that the suffix passed to xattr
handlers from VFS is always constructed from the full name by just
incerementing the pointer. This doesn't necessarily hold for the callers
of kernfs_security_xattr_*(), so their usage will easily lead to
out-of-bounds access.

Fix this by moving the xattr name reconstruction to the VFS xattr
handlers and replacing the kernfs_security_xattr_*() helpers with more
general kernfs_xattr_*() helpers that take full xattr name and allow
accessing all kernfs node's xattrs.

Reported-by: kernel test robot <rong.a.chen@intel.com>
Fixes: b230d5aba2 ("LSM: add new hook for kernfs node initialization")
Fixes: ec882da5cd ("selinux: implement the kernfs_init_security hook")
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-04-04 09:00:27 -04:00
Ondrej Mosnacek b230d5aba2 LSM: add new hook for kernfs node initialization
This patch introduces a new security hook that is intended for
initializing the security data for newly created kernfs nodes, which
provide a way of storing a non-default security context, but need to
operate independently from mounts (and therefore may not have an
associated inode at the moment of creation).

The main motivation is to allow kernfs nodes to inherit the context of
the parent under SELinux, similar to the behavior of
security_inode_init_security(). Other LSMs may implement their own logic
for handling the creation of new nodes.

This patch also adds helper functions to <linux/kernfs.h> for
getting/setting security xattrs of a kernfs node so that LSMs hooks are
able to do their job. Other important attributes should be accessible
direcly in the kernfs_node fields (in case there is need for more, then
new helpers should be added to kernfs.h along with the patch that needs
them).

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: more manual merge fixes]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-03-20 22:01:02 -04:00
Ondrej Mosnacek 0ac6075a32 kernfs: use simple_xattrs for security attributes
Replace the special handling of security xattrs with simple_xattrs, as
is already done for the trusted xattrs. This simplifies the code and
allows LSMs to use more than just a single xattr to do their business.

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: manual merge fixes]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-03-20 21:54:33 -04:00
Ondrej Mosnacek d0c9c153b4 kernfs: do not alloc iattrs in kernfs_xattr_get
This is a read-only operation, so we can simply return -ENODATA if
kn->iattr is NULL.

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: minor merge fixes]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-03-20 21:47:36 -04:00
Ondrej Mosnacek 0589521962 kernfs: clean up struct kernfs_iattrs
Right now, kernfs_iattrs embeds the whole struct iattr, even though it
doesn't really use half of its fields... This both leads to wasting
space and makes the code look awkward. Let's just list the few fields
we need directly in struct kernfs_iattrs.

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: merged a number of chunks manually due to fuzz]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-03-20 21:42:14 -04:00
Ayush Mittal 26e28d68b1 kernfs: Allocating memory for kernfs_iattrs with kmem_cache.
Creating a new cache for kernfs_iattrs.
Currently, memory is allocated with kzalloc() which
always gives aligned memory. On ARM, this is 64 byte aligned.
To avoid the wastage of memory in aligning the size requested,
a new cache for kernfs_iattrs is created.

Size of struct kernfs_iattrs is 80 Bytes.
On ARM, it will come in kmalloc-128 slab.
and it will come in kmalloc-192 slab if debug info is enabled.
Extra bytes taken 48 bytes.

Total number of objects created : 4096
Total saving = 48*4096 = 192 KB

After creating new slab(When debug info is enabled) :
sh-3.2# cat /proc/slabinfo
...
kernfs_iattrs_cache   4069   4096    128   32    1 : tunables    0    0    0 : slabdata    128    128      0
...

All testing has been done on ARM target.

Signed-off-by: Ayush Mittal <ayush.m@samsung.com>
Signed-off-by: Vaneet Narang <v.narang@samsung.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08 12:57:32 +01:00
Dmitry Torokhov 488dee96bb kernfs: allow creating kernfs objects with arbitrary uid/gid
This change allows creating kernfs files and directories with arbitrary
uid/gid instead of always using GLOBAL_ROOT_UID/GID by extending
kernfs_create_dir_ns() and kernfs_create_file_ns() with uid/gid arguments.
The "simple" kernfs_create_file() and kernfs_create_dir() are left alone
and always create objects belonging to the global root.

When creating symlinks ownership (uid/gid) is taken from the target kernfs
object.

Co-Developed-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-20 23:44:35 -07:00
Deepa Dinamani 95582b0083 vfs: change inode times to use struct timespec64
struct timespec is not y2038 safe. Transition vfs to use
y2038 safe struct timespec64 instead.

The change was made with the help of the following cocinelle
script. This catches about 80% of the changes.
All the header file and logic changes are included in the
first 5 rules. The rest are trivial substitutions.
I avoid changing any of the function signatures or any other
filesystem specific data structures to keep the patch simple
for review.

The script can be a little shorter by combining different cases.
But, this version was sufficient for my usecase.

virtual patch

@ depends on patch @
identifier now;
@@
- struct timespec
+ struct timespec64
  current_time ( ... )
  {
- struct timespec now = current_kernel_time();
+ struct timespec64 now = current_kernel_time64();
  ...
- return timespec_trunc(
+ return timespec64_trunc(
  ... );
  }

@ depends on patch @
identifier xtime;
@@
 struct \( iattr \| inode \| kstat \) {
 ...
-       struct timespec xtime;
+       struct timespec64 xtime;
 ...
 }

@ depends on patch @
identifier t;
@@
 struct inode_operations {
 ...
int (*update_time) (...,
-       struct timespec t,
+       struct timespec64 t,
...);
 ...
 }

@ depends on patch @
identifier t;
identifier fn_update_time =~ "update_time$";
@@
 fn_update_time (...,
- struct timespec *t,
+ struct timespec64 *t,
 ...) { ... }

@ depends on patch @
identifier t;
@@
lease_get_mtime( ... ,
- struct timespec *t
+ struct timespec64 *t
  ) { ... }

@te depends on patch forall@
identifier ts;
local idexpression struct inode *inode_node;
identifier i_xtime =~ "^i_[acm]time$";
identifier ia_xtime =~ "^ia_[acm]time$";
identifier fn_update_time =~ "update_time$";
identifier fn;
expression e, E3;
local idexpression struct inode *node1;
local idexpression struct inode *node2;
local idexpression struct iattr *attr1;
local idexpression struct iattr *attr2;
local idexpression struct iattr attr;
identifier i_xtime1 =~ "^i_[acm]time$";
identifier i_xtime2 =~ "^i_[acm]time$";
identifier ia_xtime1 =~ "^ia_[acm]time$";
identifier ia_xtime2 =~ "^ia_[acm]time$";
@@
(
(
- struct timespec ts;
+ struct timespec64 ts;
|
- struct timespec ts = current_time(inode_node);
+ struct timespec64 ts = current_time(inode_node);
)

<+... when != ts
(
- timespec_equal(&inode_node->i_xtime, &ts)
+ timespec64_equal(&inode_node->i_xtime, &ts)
|
- timespec_equal(&ts, &inode_node->i_xtime)
+ timespec64_equal(&ts, &inode_node->i_xtime)
|
- timespec_compare(&inode_node->i_xtime, &ts)
+ timespec64_compare(&inode_node->i_xtime, &ts)
|
- timespec_compare(&ts, &inode_node->i_xtime)
+ timespec64_compare(&ts, &inode_node->i_xtime)
|
ts = current_time(e)
|
fn_update_time(..., &ts,...)
|
inode_node->i_xtime = ts
|
node1->i_xtime = ts
|
ts = inode_node->i_xtime
|
<+... attr1->ia_xtime ...+> = ts
|
ts = attr1->ia_xtime
|
ts.tv_sec
|
ts.tv_nsec
|
btrfs_set_stack_timespec_sec(..., ts.tv_sec)
|
btrfs_set_stack_timespec_nsec(..., ts.tv_nsec)
|
- ts = timespec64_to_timespec(
+ ts =
...
-)
|
- ts = ktime_to_timespec(
+ ts = ktime_to_timespec64(
...)
|
- ts = E3
+ ts = timespec_to_timespec64(E3)
|
- ktime_get_real_ts(&ts)
+ ktime_get_real_ts64(&ts)
|
fn(...,
- ts
+ timespec64_to_timespec(ts)
,...)
)
...+>
(
<... when != ts
- return ts;
+ return timespec64_to_timespec(ts);
...>
)
|
- timespec_equal(&node1->i_xtime1, &node2->i_xtime2)
+ timespec64_equal(&node1->i_xtime2, &node2->i_xtime2)
|
- timespec_equal(&node1->i_xtime1, &attr2->ia_xtime2)
+ timespec64_equal(&node1->i_xtime2, &attr2->ia_xtime2)
|
- timespec_compare(&node1->i_xtime1, &node2->i_xtime2)
+ timespec64_compare(&node1->i_xtime1, &node2->i_xtime2)
|
node1->i_xtime1 =
- timespec_trunc(attr1->ia_xtime1,
+ timespec64_trunc(attr1->ia_xtime1,
...)
|
- attr1->ia_xtime1 = timespec_trunc(attr2->ia_xtime2,
+ attr1->ia_xtime1 =  timespec64_trunc(attr2->ia_xtime2,
...)
|
- ktime_get_real_ts(&attr1->ia_xtime1)
+ ktime_get_real_ts64(&attr1->ia_xtime1)
|
- ktime_get_real_ts(&attr.ia_xtime1)
+ ktime_get_real_ts64(&attr.ia_xtime1)
)

@ depends on patch @
struct inode *node;
struct iattr *attr;
identifier fn;
identifier i_xtime =~ "^i_[acm]time$";
identifier ia_xtime =~ "^ia_[acm]time$";
expression e;
@@
(
- fn(node->i_xtime);
+ fn(timespec64_to_timespec(node->i_xtime));
|
 fn(...,
- node->i_xtime);
+ timespec64_to_timespec(node->i_xtime));
|
- e = fn(attr->ia_xtime);
+ e = fn(timespec64_to_timespec(attr->ia_xtime));
)

@ depends on patch forall @
struct inode *node;
struct iattr *attr;
identifier i_xtime =~ "^i_[acm]time$";
identifier ia_xtime =~ "^ia_[acm]time$";
identifier fn;
@@
{
+ struct timespec ts;
<+...
(
+ ts = timespec64_to_timespec(node->i_xtime);
fn (...,
- &node->i_xtime,
+ &ts,
...);
|
+ ts = timespec64_to_timespec(attr->ia_xtime);
fn (...,
- &attr->ia_xtime,
+ &ts,
...);
)
...+>
}

@ depends on patch forall @
struct inode *node;
struct iattr *attr;
struct kstat *stat;
identifier ia_xtime =~ "^ia_[acm]time$";
identifier i_xtime =~ "^i_[acm]time$";
identifier xtime =~ "^[acm]time$";
identifier fn, ret;
@@
{
+ struct timespec ts;
<+...
(
+ ts = timespec64_to_timespec(node->i_xtime);
ret = fn (...,
- &node->i_xtime,
+ &ts,
...);
|
+ ts = timespec64_to_timespec(node->i_xtime);
ret = fn (...,
- &node->i_xtime);
+ &ts);
|
+ ts = timespec64_to_timespec(attr->ia_xtime);
ret = fn (...,
- &attr->ia_xtime,
+ &ts,
...);
|
+ ts = timespec64_to_timespec(attr->ia_xtime);
ret = fn (...,
- &attr->ia_xtime);
+ &ts);
|
+ ts = timespec64_to_timespec(stat->xtime);
ret = fn (...,
- &stat->xtime);
+ &ts);
)
...+>
}

@ depends on patch @
struct inode *node;
struct inode *node2;
identifier i_xtime1 =~ "^i_[acm]time$";
identifier i_xtime2 =~ "^i_[acm]time$";
identifier i_xtime3 =~ "^i_[acm]time$";
struct iattr *attrp;
struct iattr *attrp2;
struct iattr attr ;
identifier ia_xtime1 =~ "^ia_[acm]time$";
identifier ia_xtime2 =~ "^ia_[acm]time$";
struct kstat *stat;
struct kstat stat1;
struct timespec64 ts;
identifier xtime =~ "^[acmb]time$";
expression e;
@@
(
( node->i_xtime2 \| attrp->ia_xtime2 \| attr.ia_xtime2 \) = node->i_xtime1  ;
|
 node->i_xtime2 = \( node2->i_xtime1 \| timespec64_trunc(...) \);
|
 node->i_xtime2 = node->i_xtime1 = node->i_xtime3 = \(ts \| current_time(...) \);
|
 node->i_xtime1 = node->i_xtime3 = \(ts \| current_time(...) \);
|
 stat->xtime = node2->i_xtime1;
|
 stat1.xtime = node2->i_xtime1;
|
( node->i_xtime2 \| attrp->ia_xtime2 \) = attrp->ia_xtime1  ;
|
( attrp->ia_xtime1 \| attr.ia_xtime1 \) = attrp2->ia_xtime2;
|
- e = node->i_xtime1;
+ e = timespec64_to_timespec( node->i_xtime1 );
|
- e = attrp->ia_xtime1;
+ e = timespec64_to_timespec( attrp->ia_xtime1 );
|
node->i_xtime1 = current_time(...);
|
 node->i_xtime2 = node->i_xtime1 = node->i_xtime3 =
- e;
+ timespec_to_timespec64(e);
|
 node->i_xtime1 = node->i_xtime3 =
- e;
+ timespec_to_timespec64(e);
|
- node->i_xtime1 = e;
+ node->i_xtime1 = timespec_to_timespec64(e);
)

Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Cc: <anton@tuxera.com>
Cc: <balbi@kernel.org>
Cc: <bfields@fieldses.org>
Cc: <darrick.wong@oracle.com>
Cc: <dhowells@redhat.com>
Cc: <dsterba@suse.com>
Cc: <dwmw2@infradead.org>
Cc: <hch@lst.de>
Cc: <hirofumi@mail.parknet.co.jp>
Cc: <hubcap@omnibond.com>
Cc: <jack@suse.com>
Cc: <jaegeuk@kernel.org>
Cc: <jaharkes@cs.cmu.edu>
Cc: <jslaby@suse.com>
Cc: <keescook@chromium.org>
Cc: <mark@fasheh.com>
Cc: <miklos@szeredi.hu>
Cc: <nico@linaro.org>
Cc: <reiserfs-devel@vger.kernel.org>
Cc: <richard@nod.at>
Cc: <sage@redhat.com>
Cc: <sfrench@samba.org>
Cc: <swhiteho@redhat.com>
Cc: <tj@kernel.org>
Cc: <trond.myklebust@primarydata.com>
Cc: <tytso@mit.edu>
Cc: <viro@zeniv.linux.org.uk>
2018-06-05 16:57:31 -07:00
Shaohua Li c53cd490b1 kernfs: introduce kernfs_node_id
inode number and generation can identify a kernfs node. We are going to
export the identification by exportfs operations, so put ino and
generation into a separate structure. It's convenient when later patches
use the identification.

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-07-29 09:00:03 -06:00
Shaohua Li 319ba91d35 kernfs: don't set dentry->d_fsdata
When working on adding exportfs operations in kernfs, I found it's hard
to initialize dentry->d_fsdata in the exportfs operations. Looks there
is no way to do it without race condition. Look at the kernfs code
closely, there is no point to set dentry->d_fsdata. inode->i_private
already points to kernfs_node, and we can get inode from a dentry. So
this patch just delete the d_fsdata usage.

Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-07-29 09:00:03 -06:00
Shaohua Li 4a3ef68aca kernfs: implement i_generation
Set i_generation for kernfs inode. This is required to implement
exportfs operations. The generation is 32-bit, so it's possible the
generation wraps up and we find stale files. To reduce the posssibility,
we don't reuse inode numer immediately. When the inode number allocation
wraps, we increase generation number. In this way generation/inode
number consist of a 64-bit number which is unlikely duplicated. This
does make the idr tree more sparse and waste some memory. Since idr
manages 32-bit keys, idr uses a 6-level radix tree, each level covers 6
bits of the key. In a 100k inode kernfs, the worst case will have around
300k radix tree node. Each node is 576bytes, so the tree will use about
~150M memory. Sounds not too bad, if this really is a problem, we should
find better data structure.

Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-07-29 09:00:03 -06:00
David Howells a528d35e8b statx: Add a system call to make enhanced file info available
Add a system call to make extended file information available, including
file creation and some attribute flags where available through the
underlying filesystem.

The getattr inode operation is altered to take two additional arguments: a
u32 request_mask and an unsigned int flags that indicate the
synchronisation mode.  This change is propagated to the vfs_getattr*()
function.

Functions like vfs_stat() are now inline wrappers around new functions
vfs_statx() and vfs_statx_fd() to reduce stack usage.

========
OVERVIEW
========

The idea was initially proposed as a set of xattrs that could be retrieved
with getxattr(), but the general preference proved to be for a new syscall
with an extended stat structure.

A number of requests were gathered for features to be included.  The
following have been included:

 (1) Make the fields a consistent size on all arches and make them large.

 (2) Spare space, request flags and information flags are provided for
     future expansion.

 (3) Better support for the y2038 problem [Arnd Bergmann] (tv_sec is an
     __s64).

 (4) Creation time: The SMB protocol carries the creation time, which could
     be exported by Samba, which will in turn help CIFS make use of
     FS-Cache as that can be used for coherency data (stx_btime).

     This is also specified in NFSv4 as a recommended attribute and could
     be exported by NFSD [Steve French].

 (5) Lightweight stat: Ask for just those details of interest, and allow a
     netfs (such as NFS) to approximate anything not of interest, possibly
     without going to the server [Trond Myklebust, Ulrich Drepper, Andreas
     Dilger] (AT_STATX_DONT_SYNC).

 (6) Heavyweight stat: Force a netfs to go to the server, even if it thinks
     its cached attributes are up to date [Trond Myklebust]
     (AT_STATX_FORCE_SYNC).

And the following have been left out for future extension:

 (7) Data version number: Could be used by userspace NFS servers [Aneesh
     Kumar].

     Can also be used to modify fill_post_wcc() in NFSD which retrieves
     i_version directly, but has just called vfs_getattr().  It could get
     it from the kstat struct if it used vfs_xgetattr() instead.

     (There's disagreement on the exact semantics of a single field, since
     not all filesystems do this the same way).

 (8) BSD stat compatibility: Including more fields from the BSD stat such
     as creation time (st_btime) and inode generation number (st_gen)
     [Jeremy Allison, Bernd Schubert].

 (9) Inode generation number: Useful for FUSE and userspace NFS servers
     [Bernd Schubert].

     (This was asked for but later deemed unnecessary with the
     open-by-handle capability available and caused disagreement as to
     whether it's a security hole or not).

(10) Extra coherency data may be useful in making backups [Andreas Dilger].

     (No particular data were offered, but things like last backup
     timestamp, the data version number and the DOS archive bit would come
     into this category).

(11) Allow the filesystem to indicate what it can/cannot provide: A
     filesystem can now say it doesn't support a standard stat feature if
     that isn't available, so if, for instance, inode numbers or UIDs don't
     exist or are fabricated locally...

     (This requires a separate system call - I have an fsinfo() call idea
     for this).

(12) Store a 16-byte volume ID in the superblock that can be returned in
     struct xstat [Steve French].

     (Deferred to fsinfo).

(13) Include granularity fields in the time data to indicate the
     granularity of each of the times (NFSv4 time_delta) [Steve French].

     (Deferred to fsinfo).

(14) FS_IOC_GETFLAGS value.  These could be translated to BSD's st_flags.
     Note that the Linux IOC flags are a mess and filesystems such as Ext4
     define flags that aren't in linux/fs.h, so translation in the kernel
     may be a necessity (or, possibly, we provide the filesystem type too).

     (Some attributes are made available in stx_attributes, but the general
     feeling was that the IOC flags were to ext[234]-specific and shouldn't
     be exposed through statx this way).

(15) Mask of features available on file (eg: ACLs, seclabel) [Brad Boyer,
     Michael Kerrisk].

     (Deferred, probably to fsinfo.  Finding out if there's an ACL or
     seclabal might require extra filesystem operations).

(16) Femtosecond-resolution timestamps [Dave Chinner].

     (A __reserved field has been left in the statx_timestamp struct for
     this - if there proves to be a need).

(17) A set multiple attributes syscall to go with this.

===============
NEW SYSTEM CALL
===============

The new system call is:

	int ret = statx(int dfd,
			const char *filename,
			unsigned int flags,
			unsigned int mask,
			struct statx *buffer);

The dfd, filename and flags parameters indicate the file to query, in a
similar way to fstatat().  There is no equivalent of lstat() as that can be
emulated with statx() by passing AT_SYMLINK_NOFOLLOW in flags.  There is
also no equivalent of fstat() as that can be emulated by passing a NULL
filename to statx() with the fd of interest in dfd.

Whether or not statx() synchronises the attributes with the backing store
can be controlled by OR'ing a value into the flags argument (this typically
only affects network filesystems):

 (1) AT_STATX_SYNC_AS_STAT tells statx() to behave as stat() does in this
     respect.

 (2) AT_STATX_FORCE_SYNC will require a network filesystem to synchronise
     its attributes with the server - which might require data writeback to
     occur to get the timestamps correct.

 (3) AT_STATX_DONT_SYNC will suppress synchronisation with the server in a
     network filesystem.  The resulting values should be considered
     approximate.

mask is a bitmask indicating the fields in struct statx that are of
interest to the caller.  The user should set this to STATX_BASIC_STATS to
get the basic set returned by stat().  It should be noted that asking for
more information may entail extra I/O operations.

buffer points to the destination for the data.  This must be 256 bytes in
size.

======================
MAIN ATTRIBUTES RECORD
======================

The following structures are defined in which to return the main attribute
set:

	struct statx_timestamp {
		__s64	tv_sec;
		__s32	tv_nsec;
		__s32	__reserved;
	};

	struct statx {
		__u32	stx_mask;
		__u32	stx_blksize;
		__u64	stx_attributes;
		__u32	stx_nlink;
		__u32	stx_uid;
		__u32	stx_gid;
		__u16	stx_mode;
		__u16	__spare0[1];
		__u64	stx_ino;
		__u64	stx_size;
		__u64	stx_blocks;
		__u64	__spare1[1];
		struct statx_timestamp	stx_atime;
		struct statx_timestamp	stx_btime;
		struct statx_timestamp	stx_ctime;
		struct statx_timestamp	stx_mtime;
		__u32	stx_rdev_major;
		__u32	stx_rdev_minor;
		__u32	stx_dev_major;
		__u32	stx_dev_minor;
		__u64	__spare2[14];
	};

The defined bits in request_mask and stx_mask are:

	STATX_TYPE		Want/got stx_mode & S_IFMT
	STATX_MODE		Want/got stx_mode & ~S_IFMT
	STATX_NLINK		Want/got stx_nlink
	STATX_UID		Want/got stx_uid
	STATX_GID		Want/got stx_gid
	STATX_ATIME		Want/got stx_atime{,_ns}
	STATX_MTIME		Want/got stx_mtime{,_ns}
	STATX_CTIME		Want/got stx_ctime{,_ns}
	STATX_INO		Want/got stx_ino
	STATX_SIZE		Want/got stx_size
	STATX_BLOCKS		Want/got stx_blocks
	STATX_BASIC_STATS	[The stuff in the normal stat struct]
	STATX_BTIME		Want/got stx_btime{,_ns}
	STATX_ALL		[All currently available stuff]

stx_btime is the file creation time, stx_mask is a bitmask indicating the
data provided and __spares*[] are where as-yet undefined fields can be
placed.

Time fields are structures with separate seconds and nanoseconds fields
plus a reserved field in case we want to add even finer resolution.  Note
that times will be negative if before 1970; in such a case, the nanosecond
fields will also be negative if not zero.

The bits defined in the stx_attributes field convey information about a
file, how it is accessed, where it is and what it does.  The following
attributes map to FS_*_FL flags and are the same numerical value:

	STATX_ATTR_COMPRESSED		File is compressed by the fs
	STATX_ATTR_IMMUTABLE		File is marked immutable
	STATX_ATTR_APPEND		File is append-only
	STATX_ATTR_NODUMP		File is not to be dumped
	STATX_ATTR_ENCRYPTED		File requires key to decrypt in fs

Within the kernel, the supported flags are listed by:

	KSTAT_ATTR_FS_IOC_FLAGS

[Are any other IOC flags of sufficient general interest to be exposed
through this interface?]

New flags include:

	STATX_ATTR_AUTOMOUNT		Object is an automount trigger

These are for the use of GUI tools that might want to mark files specially,
depending on what they are.

Fields in struct statx come in a number of classes:

 (0) stx_dev_*, stx_blksize.

     These are local system information and are always available.

 (1) stx_mode, stx_nlinks, stx_uid, stx_gid, stx_[amc]time, stx_ino,
     stx_size, stx_blocks.

     These will be returned whether the caller asks for them or not.  The
     corresponding bits in stx_mask will be set to indicate whether they
     actually have valid values.

     If the caller didn't ask for them, then they may be approximated.  For
     example, NFS won't waste any time updating them from the server,
     unless as a byproduct of updating something requested.

     If the values don't actually exist for the underlying object (such as
     UID or GID on a DOS file), then the bit won't be set in the stx_mask,
     even if the caller asked for the value.  In such a case, the returned
     value will be a fabrication.

     Note that there are instances where the type might not be valid, for
     instance Windows reparse points.

 (2) stx_rdev_*.

     This will be set only if stx_mode indicates we're looking at a
     blockdev or a chardev, otherwise will be 0.

 (3) stx_btime.

     Similar to (1), except this will be set to 0 if it doesn't exist.

=======
TESTING
=======

The following test program can be used to test the statx system call:

	samples/statx/test-statx.c

Just compile and run, passing it paths to the files you want to examine.
The file is built automatically if CONFIG_SAMPLES is enabled.

Here's some example output.  Firstly, an NFS directory that crosses to
another FSID.  Note that the AUTOMOUNT attribute is set because transiting
this directory will cause d_automount to be invoked by the VFS.

	[root@andromeda ~]# /tmp/test-statx -A /warthog/data
	statx(/warthog/data) = 0
	results=7ff
	  Size: 4096            Blocks: 8          IO Block: 1048576  directory
	Device: 00:26           Inode: 1703937     Links: 125
	Access: (3777/drwxrwxrwx)  Uid:     0   Gid:  4041
	Access: 2016-11-24 09:02:12.219699527+0000
	Modify: 2016-11-17 10:44:36.225653653+0000
	Change: 2016-11-17 10:44:36.225653653+0000
	Attributes: 0000000000001000 (-------- -------- -------- -------- -------- -------- ---m---- --------)

Secondly, the result of automounting on that directory.

	[root@andromeda ~]# /tmp/test-statx /warthog/data
	statx(/warthog/data) = 0
	results=7ff
	  Size: 4096            Blocks: 8          IO Block: 1048576  directory
	Device: 00:27           Inode: 2           Links: 125
	Access: (3777/drwxrwxrwx)  Uid:     0   Gid:  4041
	Access: 2016-11-24 09:02:12.219699527+0000
	Modify: 2016-11-17 10:44:36.225653653+0000
	Change: 2016-11-17 10:44:36.225653653+0000

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-03-02 20:51:15 -05:00
Bart Van Assche b5a0623444 kernfs: Declare two local data structures static
This was spotted by the 'sparse' static checker.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-29 20:58:31 +01:00
Linus Torvalds 101105b171 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull more vfs updates from Al Viro:
 ">rename2() work from Miklos + current_time() from Deepa"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fs: Replace current_fs_time() with current_time()
  fs: Replace CURRENT_TIME_SEC with current_time() for inode timestamps
  fs: Replace CURRENT_TIME with current_time() for inode timestamps
  fs: proc: Delete inode time initializations in proc_alloc_inode()
  vfs: Add current_time() api
  vfs: add note about i_op->rename changes to porting
  fs: rename "rename2" i_op to "rename"
  vfs: remove unused i_op->rename
  fs: make remaining filesystems use .rename2
  libfs: support RENAME_NOREPLACE in simple_rename()
  fs: support RENAME_NOREPLACE for local filesystems
  ncpfs: fix unused variable warning
2016-10-10 20:16:43 -07:00
Linus Torvalds 97d2116708 Merge branch 'work.xattr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs xattr updates from Al Viro:
 "xattr stuff from Andreas

  This completes the switch to xattr_handler ->get()/->set() from
  ->getxattr/->setxattr/->removexattr"

* 'work.xattr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  vfs: Remove {get,set,remove}xattr inode operations
  xattr: Stop calling {get,set,remove}xattr inode operations
  vfs: Check for the IOP_XATTR flag in listxattr
  xattr: Add __vfs_{get,set,remove}xattr helpers
  libfs: Use IOP_XATTR flag for empty directory handling
  vfs: Use IOP_XATTR flag for bad-inode handling
  vfs: Add IOP_XATTR inode operations flag
  vfs: Move xattr_resolve_name to the front of fs/xattr.c
  ecryptfs: Switch to generic xattr handlers
  sockfs: Get rid of getxattr iop
  sockfs: getxattr: Fail with -EOPNOTSUPP for invalid attribute names
  kernfs: Switch to generic xattr handlers
  hfs: Switch to generic xattr handlers
  jffs2: Remove jffs2_{get,set,remove}xattr macros
  xattr: Remove unnecessary NULL attribute name check
2016-10-10 17:11:50 -07:00
Andreas Gruenbacher fd50ecaddf vfs: Remove {get,set,remove}xattr inode operations
These inode operations are no longer used; remove them.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-10-07 21:48:36 -04:00
Andreas Gruenbacher e72a1a8b3a kernfs: Switch to generic xattr handlers
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-10-06 22:17:38 -04:00
Deepa Dinamani c2050a454c fs: Replace current_fs_time() with current_time()
current_fs_time() uses struct super_block* as an argument.
As per Linus's suggestion, this is changed to take struct
inode* as a parameter instead. This is because the function
is primarily meant for vfs inode timestamps.
Also the function was renamed as per Arnd's suggestion.

Change all calls to current_fs_time() to use the new
current_time() function instead. current_fs_time() will be
deleted.

Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-09-27 21:06:22 -04:00
Jan Kara 31051c85b5 fs: Give dentry to inode_change_ok() instead of inode
inode_change_ok() will be resposible for clearing capabilities and IMA
extended attributes and as such will need dentry. Give it as an argument
to inode_change_ok() instead of an inode. Also rename inode_change_ok()
to setattr_prepare() to better relect that it does also some
modifications in addition to checks.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
2016-09-22 10:56:19 +02:00
Al Viro 3767e255b3 switch ->setxattr() to passing dentry and inode separately
smack ->d_instantiate() uses ->setxattr(), so to be able to call it before
we'd hashed the new dentry and attached it to inode, we need ->setxattr()
instances getting the inode as an explicit argument rather than obtaining
it from dentry.

Similar change for ->getxattr() had been done in commit ce23e64.  Unlike
->getxattr() (which is used by both selinux and smack instances of
->d_instantiate()) ->setxattr() is used only by smack one and unfortunately
it got missed back then.

Reported-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Tested-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-27 20:09:16 -04:00
Linus Torvalds 3aa2fc1667 driver core update for 4.7-rc1
Here's the "big" driver core update for 4.7-rc1.
 
 Mostly just debugfs changes, the long-known and messy races with removing
 debugfs files should be fixed thanks to the great work of Nicolai Stange.  We
 also have some isa updates in here (the x86 maintainers told me to take it
 through this tree), a new warning when we run out of dynamic char major
 numbers, and a few other assorted changes, details in the shortlog.
 
 All have been in linux-next for some time with no reported issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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 Version: GnuPG v2
 
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 =i+0H
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Merge tag 'driver-core-4.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here's the "big" driver core update for 4.7-rc1.

  Mostly just debugfs changes, the long-known and messy races with
  removing debugfs files should be fixed thanks to the great work of
  Nicolai Stange.  We also have some isa updates in here (the x86
  maintainers told me to take it through this tree), a new warning when
  we run out of dynamic char major numbers, and a few other assorted
  changes, details in the shortlog.

  All have been in linux-next for some time with no reported issues"

* tag 'driver-core-4.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (32 commits)
  Revert "base: dd: don't remove driver_data in -EPROBE_DEFER case"
  gpio: ws16c48: Utilize the ISA bus driver
  gpio: 104-idio-16: Utilize the ISA bus driver
  gpio: 104-idi-48: Utilize the ISA bus driver
  gpio: 104-dio-48e: Utilize the ISA bus driver
  watchdog: ebc-c384_wdt: Utilize the ISA bus driver
  iio: stx104: Utilize the module_isa_driver and max_num_isa_dev macros
  iio: stx104: Add X86 dependency to STX104 Kconfig option
  Documentation: Add ISA bus driver documentation
  isa: Implement the max_num_isa_dev macro
  isa: Implement the module_isa_driver macro
  pnp: pnpbios: Add explicit X86_32 dependency to PNPBIOS
  isa: Decouple X86_32 dependency from the ISA Kconfig option
  driver-core: use 'dev' argument in dev_dbg_ratelimited stub
  base: dd: don't remove driver_data in -EPROBE_DEFER case
  kernfs: Move faulting copy_user operations outside of the mutex
  devcoredump: add scatterlist support
  debugfs: unproxify files created through debugfs_create_u32_array()
  debugfs: unproxify files created through debugfs_create_blob()
  debugfs: unproxify files created through debugfs_create_bool()
  ...
2016-05-20 21:26:15 -07:00
Al Viro ce23e64013 ->getxattr(): pass dentry and inode as separate arguments
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-04-11 00:48:00 -04:00
Deepa Dinamani 3a3a5fece6 fs: kernfs: Replace CURRENT_TIME by current_fs_time()
This is in preparation for the series that transitions
filesystem timestamps to use 64 bit time and hence make
them y2038 safe.

CURRENT_TIME macro will be deleted before merging the
aforementioned series.

Use current_fs_time() instead of CURRENT_TIME for inode
timestamps.

struct kernfs_node is associated with a sysfs file/ directory.
Truncate the values to appropriate time granularity when
writing to inode timestamps of the files.

ktime_get_real_ts() is used to obtain times for
struct kernfs_iattrs. Since these times are later assigned to
inode times using timespec_truncate() for all filesystem based
operations, we can save the supers list traversal time here by
using ktime_get_real_ts() directly.

Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-29 10:11:44 -07:00
Andreas Gruenbacher 786534b92f tmpfs: listxattr should include POSIX ACL xattrs
When a file on tmpfs has an ACL or a Default ACL, listxattr should include the
corresponding xattr name.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: James Morris <james.l.morris@oracle.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: linux-mm@kvack.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-06 21:34:15 -05:00