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Patch "lift the "already marked killed" case into shrink_dentry_list()" has been added to the 3.14-stable tree

PATCH [email protected] 1 participant 1 message Mar 1, 2016

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

lift the "already marked killed" case into 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:
lift-the-already-marked-killed-case-into-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.

Quoted 1 line

From 64fd72e0a44bdd62c5ca277cb24d0d02b2d8e9dc Mon Sep 17 00:00:00 2001

From: Al Viro <[email protected]>
Date: Wed, 28 May 2014 09:48:44 -0400
Subject: lift the "already marked killed" case into shrink_dentry_list()

From: Al Viro <[email protected]>

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.

---
 fs/dcache.c |   15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)
fs/dcache.c +9 -6
@@ -453,12 +453,6 @@ dentry_kill(struct dentry *dentry, int u
 	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 li
 			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.

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