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>

diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index 99ec5b4..4d83ced 100644 (file)
--- 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;
 }