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

    md/raid10: fix two bugs in handling of known-bad-blocks.

to the 3.4-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:
     md-raid10-fix-two-bugs-in-handling-of-known-bad-blocks.patch
and it can be found in the queue-3.4 subdirectory.

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


>From b50c259e25d9260b9108dc0c2964c26e5ecbe1c1 Mon Sep 17 00:00:00 2001
From: NeilBrown <[email protected]>
Date: Tue, 14 Jan 2014 10:38:09 +1100
Subject: md/raid10: fix two bugs in handling of known-bad-blocks.

From: NeilBrown <[email protected]>

commit b50c259e25d9260b9108dc0c2964c26e5ecbe1c1 upstream.

If we discover a bad block when reading we split the request and
potentially read some of it from a different device.

The code path of this has two bugs in RAID10.
1/ we get a spin_lock with _irq, but unlock without _irq!!
2/ The calculation of 'sectors_handled' is wrong, as can be clearly
   seen by comparison with raid1.c

This leads to at least 2 warnings and a probable crash is a RAID10
ever had known bad blocks.

Fixes: 856e08e23762dfb92ffc68fd0a8d228f9e152160
Reported-by: Damian Nowak <[email protected]>
URL: https://bugzilla.kernel.org/show_bug.cgi?id=68181
Signed-off-by: NeilBrown <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

---
 drivers/md/raid10.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -1117,7 +1117,7 @@ read_again:
                        /* Could not read all from this device, so we will
                         * need another r10_bio.
                         */
-                       sectors_handled = (r10_bio->sectors + max_sectors
+                       sectors_handled = (r10_bio->sector + max_sectors
                                           - bio->bi_sector);
                        r10_bio->sectors = max_sectors;
                        spin_lock_irq(&conf->device_lock);
@@ -1125,7 +1125,7 @@ read_again:
                                bio->bi_phys_segments = 2;
                        else
                                bio->bi_phys_segments++;
-                       spin_unlock(&conf->device_lock);
+                       spin_unlock_irq(&conf->device_lock);
                        /* Cannot call generic_make_request directly
                         * as that will be queued in __generic_make_request
                         * and subsequent mempool_alloc might block


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

queue-3.4/md-raid10-fix-bug-when-raid10-recovery-fails-to-recover-a-block.patch
queue-3.4/md-raid5-fix-possible-confusion-when-multiple-write-errors-occur.patch
queue-3.4/md-raid10-fix-two-bugs-in-handling-of-known-bad-blocks.patch
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