[3.13.y.z extended stable] Patch "genhd: fix leftover might_sleep() in blk_free_devt()" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    genhd: fix leftover might_sleep() in blk_free_devt()

to the linux-3.13.y-queue branch of the 3.13.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.13.y-queue

This patch is scheduled to be released in version 3.13.11.9.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.13.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 8d3ffbabe314097cf51398ad1801b91f88da9138 Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe at fb.com>
Date: Tue, 16 Sep 2014 13:38:51 -0600
Subject: genhd: fix leftover might_sleep() in blk_free_devt()

commit 46f341ffcfb5d8530f7d1e60f3be06cce6661b62 upstream.

Commit 2da78092 changed the locking from a mutex to a spinlock,
so we now longer sleep in this context. But there was a leftover
might_sleep() in there, which now triggers since we do the final
free from an RCU callback. Get rid of it.

Reported-by: Pontus Fuchs <pontus.fuchs at gmail.com>
Signed-off-by: Jens Axboe <axboe at fb.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 block/genhd.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/block/genhd.c b/block/genhd.c
index 09da5e4..e6723bd 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -445,8 +445,6 @@ int blk_alloc_devt(struct hd_struct *part, dev_t *devt)
  */
 void blk_free_devt(dev_t devt)
 {
-	might_sleep();
-
 	if (devt == MKDEV(0, 0))
 		return;

--
1.9.1