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

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.

Cc: stable@vger.kernel.org (v3.1+)
Fixes: 856e08e23762dfb92ffc68fd0a8d228f9e152160
Reported-by: Damian Nowak <spam@nowaker.net>
URL: https://bugzilla.kernel.org/show_bug.cgi?id=68181
Signed-off-by: NeilBrown <neilb@suse.de>

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index c504e8389e69e3ab9ad717b9f83d0c19c2008d68..65285211568ff69d72dd6ef18bd97cad735ab6ea 100644 (file)
--- 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;
                        spin_lock_irq(&conf->device_lock);
@@ -1327,7 +1327,7 @@ 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