nfs: 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>
CC: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 4 insertions, 5 deletions

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index e474ca2b2bfe..7468735d299e 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -1135,14 +1135,13 @@ out_zap_parent:
         if (inode && S_ISDIR(inode->i_mode)) {
                 /* Purge readdir caches. */
                 nfs_zap_caches(inode);
-                /* If we have submounts, don't unhash ! */
-                if (have_submounts(dentry))
-                        goto out_valid;
                 if (dentry->d_flags & DCACHE_DISCONNECTED)
                         goto out_valid;
-                shrink_dcache_parent(dentry);
         }
-        d_drop(dentry);
+        /* If we have submounts, don't unhash ! */
+        if (check_submounts_and_drop(dentry) != 0)
+                goto out_valid;
+
         dput(parent);
         dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is invalid\n",
                         __func__, dentry->d_parent->d_name.name,