[PATCH 3.4 09/12] md/raid10: fix two bugs in handling of known-bad-blocks.

From: Greg Kroah-Hartman
Date: Sat Jan 25 2014 - 22:05:57 EST


3.4-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: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
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


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/