sysfs: use check_submounts_and_drop()

Do have_submounts(), shrink_dcache_parent() and d_drop() atomically.

check_submounts_and_drop() can deal with negative dentries and
non-directories as well.

Non-directories can also be mounted on.  And just like directories we don't
want these to disappear with invalidation.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 8 insertions, 12 deletions

diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index 99ec5b40e977..4d83cedb9fcb 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -297,7 +297,6 @@ static int sysfs_dentry_delete(const struct dentry *dentry)
 static int sysfs_dentry_revalidate(struct dentry *dentry, unsigned int flags)
 {
         struct sysfs_dirent *sd;
-        int is_dir;
         int type;
 
         if (flags & LOOKUP_RCU)
@@ -341,18 +340,15 @@ out_bad:
          * is performed at its new name the dentry will be readded
          * to the dcache hashes.
          */
-        is_dir = (sysfs_type(sd) == SYSFS_DIR);
         mutex_unlock(&sysfs_mutex);
-        if (is_dir) {
-                /* If we have submounts we must allow the vfs caches
-                 * to lie about the state of the filesystem to prevent
-                 * leaks and other nasty things.
-                 */
-                if (have_submounts(dentry))
-                        goto out_valid;
-                shrink_dcache_parent(dentry);
-        }
-        d_drop(dentry);
+
+        /* If we have submounts we must allow the vfs caches
+         * to lie about the state of the filesystem to prevent
+         * leaks and other nasty things.
+         */
+        if (check_submounts_and_drop(dentry) != 0)
+                goto out_valid;
+
         return 0;
 }