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

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>

1 files changed, 9 insertions, 6 deletions

diff --git a/fs/dcache.c b/fs/dcache.c
index 42ae01eefc07..6888dde4d568 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -455,12 +455,6 @@ 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:
@@ -815,6 +809,15 @@ 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.