Patch "expand dentry_kill(dentry, 0) in shrink_dentry_list()" has been added to the 3.14-stable tree

This is a note to let you know that I've just added the patch titled

expand dentry_kill(dentry, 0) in shrink_dentry_list()

to the 3.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
expand-dentry_kill-dentry-0-in-shrink_dentry_list.patch
and it can be found in the queue-3.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Al Viro <[email protected]>
Date: Wed, 28 May 2014 13:59:13 -0400
Subject: expand dentry_kill(dentry, 0) in shrink_dentry_list()

From: Al Viro <[email protected]>

commit ff2fde9929feb2aef45377ce56b8b12df85dda69 upstream.

Result will be massaged to saner shape in the next commits. It is ugly, no questions - the point of that one is to be a provably equivalent transformation (and it might be worth splitting a bit more).

---
 fs/dcache.c |   30 +++++++++++++++++-------------
 1 file changed, 17 insertions(+), 13 deletions(-)

@@ -802,6 +802,7 @@ static void shrink_dentry_list(struct li
 	struct dentry *dentry, *parent;
 
 	while (!list_empty(list)) {
+		struct inode *inode;
 		dentry = list_entry(list->prev, struct dentry, d_lru);
 		spin_lock(&dentry->d_lock);
 		/*

@@ -829,23 +830,26 @@ static void shrink_dentry_list(struct li
 			continue;
 		}
 
-		parent = dentry_kill(dentry, 0);
-		/*
-		 * If dentry_kill returns NULL, we have nothing more to do.
-		 */
-		if (!parent)
-			continue;
-
-		if (unlikely(parent == dentry)) {
-			/*
-			 * trylocks have failed and d_lock has been held the
-			 * whole time, so it could not have been added to any
-			 * other lists. Just add it back to the shrink list.
-			 */
+		inode = dentry->d_inode;
+		if (inode && unlikely(!spin_trylock(&inode->i_lock))) {
 			d_shrink_add(dentry, list);
 			spin_unlock(&dentry->d_lock);
 			continue;
 		}
+
+		parent = NULL;
+		if (!IS_ROOT(dentry)) {
+			parent = dentry->d_parent;
+			if (unlikely(!spin_trylock(&parent->d_lock))) {
+				if (inode)
+					spin_unlock(&inode->i_lock);
+				d_shrink_add(dentry, list);
+				spin_unlock(&dentry->d_lock);
+				continue;
+			}
+		}
+
+		__dentry_kill(dentry);
 		/*
 		 * We need to prune ancestors too. This is necessary to prevent
 		 * quadratic behavior of shrink_dcache_parent(), but is also

Patches currently in stable-queue which might be from [email protected] are

queue-3.14/lock_parent-don-t-step-on-stale-d_parent-of-all-but-freed-one.patch queue-3.14/lift-the-already-marked-killed-case-into-shrink_dentry_list.patch queue-3.14/expand-dentry_kill-dentry-0-in-shrink_dentry_list.patch queue-3.14/bcache-fix-a-leak-in-bch_cached_dev_run.patch queue-3.14/dcache-add-missing-lockdep-annotation.patch queue-3.14/dealing-with-the-rest-of-shrink_dentry_list-livelock.patch queue-3.14/split-dentry_kill.patch queue-3.14/shrink_dentry_list-take-parent-s-d_lock-earlier.patch queue-3.14/dentry_kill-doesn-t-need-the-second-argument-now.patch