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

    dm thin: fix a race in thin_dtr

to the 3.17-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:
     dm-thin-fix-a-race-in-thin_dtr.patch
and it can be found in the queue-3.17 subdirectory.

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


>From 17181fb7a0c3a279196c0eeb2caba65a1519614b Mon Sep 17 00:00:00 2001
From: Mikulas Patocka <[email protected]>
Date: Wed, 5 Nov 2014 17:00:13 -0500
Subject: dm thin: fix a race in thin_dtr

From: Mikulas Patocka <[email protected]>

commit 17181fb7a0c3a279196c0eeb2caba65a1519614b upstream.

As long as struct thin_c is in the list, anyone can grab a reference of
it.  Consequently, we must wait for the reference count to drop to zero
*after* we remove the structure from the list, not before.

Signed-off-by: Mikulas Patocka <[email protected]>
Signed-off-by: Mike Snitzer <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

---
 drivers/md/dm-thin.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- a/drivers/md/dm-thin.c
+++ b/drivers/md/dm-thin.c
@@ -3266,14 +3266,14 @@ static void thin_dtr(struct dm_target *t
        struct thin_c *tc = ti->private;
        unsigned long flags;
 
-       thin_put(tc);
-       wait_for_completion(&tc->can_destroy);
-
        spin_lock_irqsave(&tc->pool->lock, flags);
        list_del_rcu(&tc->list);
        spin_unlock_irqrestore(&tc->pool->lock, flags);
        synchronize_rcu();
 
+       thin_put(tc);
+       wait_for_completion(&tc->can_destroy);
+
        mutex_lock(&dm_thin_pool_table.mutex);
 
        __pool_dec(tc->pool);


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

queue-3.17/dm-thin-fix-a-race-in-thin_dtr.patch
queue-3.17/dm-bufio-fix-memleak-when-using-a-dm_buffer-s-inline-bio.patch
queue-3.17/dcache-fix-kmemcheck-warning-in-switch_names.patch
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