Merge branch 'work.dcache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull vfs dcache updates from Al Viro:
 "Part of this is what the trylock loop elimination series has turned
  into, part making d_move() preserve the parent (and thus the path) of
  victim, plus some general cleanups"

* 'work.dcache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (22 commits)
  d_genocide: move export to definition
  fold dentry_lock_for_move() into its sole caller and clean it up
  make non-exchanging __d_move() copy ->d_parent rather than swap them
  oprofilefs: don't oops on allocation failure
  lustre: get rid of pointless casts to struct dentry *
  debugfs_lookup(): switch to lookup_one_len_unlocked()
  fold lookup_real() into __lookup_hash()
  take out orphan externs (empty_string/slash_string)
  split d_path() and friends into a separate file
  dcache.c: trim includes
  fs/dcache: Avoid a try_lock loop in shrink_dentry_list()
  get rid of trylock loop around dentry_kill()
  handle move to LRU in retain_dentry()
  dput(): consolidate the "do we need to retain it?" into an inlined helper
  split the slow part of lock_parent() off
  now lock_parent() can't run into killed dentry
  get rid of trylock loop in locking dentries on shrink list
  d_delete(): get rid of trylock loop
  fs/dcache: Move dentry_kill() below lock_parent()
  fs/dcache: Remove stale comment from dentry_kill()
  ...

1 files changed, 17 insertions, 24 deletions

diff --git a/fs/namei.c b/fs/namei.c
index 5c2b953c352d..a09419379f5d 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1474,43 +1474,36 @@ static struct dentry *lookup_dcache(const struct qstr *name,
 }
 
 /*
- * Call i_op->lookup on the dentry.  The dentry must be negative and
- * unhashed.
- *
- * dir->d_inode->i_mutex must be held
+ * Parent directory has inode locked exclusive.  This is one
+ * and only case when ->lookup() gets called on non in-lookup
+ * dentries - as the matter of fact, this only gets called
+ * when directory is guaranteed to have no in-lookup children
+ * at all.
  */
-static struct dentry *lookup_real(struct inode *dir, struct dentry *dentry,
-				  unsigned int flags)
-{
-	struct dentry *old;
-
-	/* Don't create child dentry for a dead directory. */
-	if (unlikely(IS_DEADDIR(dir))) {
-		dput(dentry);
-		return ERR_PTR(-ENOENT);
-	}
-
-	old = dir->i_op->lookup(dir, dentry, flags);
-	if (unlikely(old)) {
-		dput(dentry);
-		dentry = old;
-	}
-	return dentry;
-}
-
 static struct dentry *__lookup_hash(const struct qstr *name,
 		struct dentry *base, unsigned int flags)
 {
 	struct dentry *dentry = lookup_dcache(name, base, flags);
+	struct dentry *old;
+	struct inode *dir = base->d_inode;
 
 	if (dentry)
 		return dentry;
 
+	/* Don't create child dentry for a dead directory. */
+	if (unlikely(IS_DEADDIR(dir)))
+		return ERR_PTR(-ENOENT);
+
 	dentry = d_alloc(base, name);
 	if (unlikely(!dentry))
 		return ERR_PTR(-ENOMEM);
 
-	return lookup_real(base->d_inode, dentry, flags);
+	old = dir->i_op->lookup(dir, dentry, flags);
+	if (unlikely(old)) {
+		dput(dentry);
+		dentry = old;
+	}
+	return dentry;
 }
 
 static int lookup_fast(struct nameidata *nd,