proc: Allow creating permanently empty directories that serve as mount points
Add a new function proc_create_mount_point that when used to creates a
directory that can not be added to.
Add a new function is_empty_pde to test if a function is a mount
point.
Update the code to use make_empty_dir_inode when reporting
a permanently empty directory to the vfs.
Update the code to not allow adding to permanently empty directories.
Update /proc/openprom and /proc/fs/nfsd to be permanently empty directories.
Cc: stable@vger.kernel.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
diff --git a/fs/proc/root.c b/fs/proc/root.c
index 64e1ab6..68feb0f 100644
--- a/fs/proc/root.c
+++ b/fs/proc/root.c
@@ -179,10 +179,10 @@
#endif
proc_mkdir("fs", NULL);
proc_mkdir("driver", NULL);
- proc_mkdir("fs/nfsd", NULL); /* somewhere for the nfsd filesystem to be mounted */
+ proc_create_mount_point("fs/nfsd"); /* somewhere for the nfsd filesystem to be mounted */
#if defined(CONFIG_SUN_OPENPROMFS) || defined(CONFIG_SUN_OPENPROMFS_MODULE)
/* just give it a mountpoint */
- proc_mkdir("openprom", NULL);
+ proc_create_mount_point("openprom");
#endif
proc_tty_init();
proc_mkdir("bus", NULL);
