diff options
| author | Ian Kent <ikent@redhat.com> | 2016-11-24 08:03:41 +1100 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2016-12-03 20:51:35 -0500 |
| commit | c6609c0a1c34fc097152b28b496236625673924f (patch) | |
| tree | 864cfb55fd8727e2a475ca44dd8d7df5a8488005 /fs/mount.h | |
| parent | fb5f51c7425ebc808d91329257cbc963e2421368 (diff) | |
vfs: add path_is_mountpoint() helper
d_mountpoint() can only be used reliably to establish if a dentry is
not mounted in any namespace. It isn't aware of the possibility there
may be multiple mounts using a given dentry that may be in a different
namespace.
Add helper functions, path_is_mountpoint(), that checks if a struct path
is a mountpoint for this case.
Link: http://lkml.kernel.org/r/20161011053358.27645.9729.stgit@pluto.themaw.net
Signed-off-by: Ian Kent <raven@themaw.net>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Omar Sandoval <osandov@osandov.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/mount.h')
| -rw-r--r-- | fs/mount.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/fs/mount.h b/fs/mount.h index d2e25d7b64b3..2c856fc47ae3 100644 --- a/fs/mount.h +++ b/fs/mount.h @@ -94,6 +94,12 @@ extern struct mount *__lookup_mnt_last(struct vfsmount *, struct dentry *); extern int __legitimize_mnt(struct vfsmount *, unsigned); extern bool legitimize_mnt(struct vfsmount *, unsigned); +static inline bool __path_is_mountpoint(const struct path *path) +{ + struct mount *m = __lookup_mnt(path->mnt, path->dentry); + return m && likely(!(m->mnt.mnt_flags & MNT_SYNC_UMOUNT)); +} + extern void __detach_mounts(struct dentry *dentry); static inline void detach_mounts(struct dentry *dentry) |