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/[email protected]
Signed-off-by: Ian Kent <[email protected]>
Cc: Al Viro <[email protected]>
Cc: Eric W. Biederman <[email protected]>
Cc: Omar Sandoval <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Al Viro <[email protected]>

0 files changed, 0 insertions, 0 deletions