[PATCH 3.11 025/233] md/raid10: fix two bugs in handling of known-bad-blocks.

From: Luis Henriques
Date: Fri Feb 07 2014 - 08:21:02 EST -stable review patch. If anyone has any objections, please let me know.


From: NeilBrown <neilb@xxxxxxx>

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 <spam@xxxxxxxxxxx>
URL: https://bugzilla.kernel.org/show_bug.cgi?id=68181
Signed-off-by: NeilBrown <neilb@xxxxxxx>
Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
drivers/md/raid10.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 73dc8a3..cc9b777 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -1319,7 +1319,7 @@ 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;
@@ -1327,7 +1327,7 @@ read_again:
bio->bi_phys_segments = 2;
- 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

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