lift the "already marked killed" case into shrink_dentry_list()

commit 64fd72e0a44bdd62c5ca277cb24d0d02b2d8e9dc upstream.

It can happen only when dentry_kill() is called with unlock_on_failure
equal to 0 - other callers had dentry pinned until the moment they've
got ->d_lock and DCACHE_DENTRY_KILLED is set only after lockref_mark_dead().

IOW, only one of three call sites of dentry_kill() might end up reaching
that code.  Just move it there.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/dcache.c b/fs/dcache.c
index 65ccdf0e2854b5b0366942930998cc199f43174a..cb40f06ce2067340d3423e514801038b945f3901 100644 (file)
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -453,12 +453,6 @@ dentry_kill(struct dentry *dentry, int unlock_on_failure)
        struct dentry *parent = NULL;
        bool can_free = true;
 
-       if (unlikely(dentry->d_flags & DCACHE_DENTRY_KILLED)) {
-               can_free = dentry->d_flags & DCACHE_MAY_FREE;
-               spin_unlock(&dentry->d_lock);
-               goto out;
-       }
-
        inode = dentry->d_inode;
        if (inode && !spin_trylock(&inode->i_lock)) {
 relock:
@@ -816,6 +810,15 @@ static void shrink_dentry_list(struct list_head *list)
                        continue;
                }
 
+
+               if (unlikely(dentry->d_flags & DCACHE_DENTRY_KILLED)) {
+                       bool can_free = dentry->d_flags & DCACHE_MAY_FREE;
+                       spin_unlock(&dentry->d_lock);
+                       if (can_free)
+                               dentry_free(dentry);
+                       continue;
+               }
+
                parent = dentry_kill(dentry, 0);
                /*
                 * If dentry_kill returns NULL, we have nothing more to do.