[PATCH] md: improvements to raid5 handling of read errors

Two refinements to the 'attempt-overwrite-on-read-error' mechanism.
1/ If the array is read-only, don't attempt an over-write.
2/ If there are more than max_nr_stripes read errors on a device with
   no success, fail the drive.  This will make sure a dead
   drive will be eventually kicked even when we aren't trying
   to rewrite (which would normally kick a dead drive more quickly.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 3db5c3513072..3fb80397f8aa 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -1582,6 +1582,7 @@ static mdk_rdev_t *md_import_device(dev_t newdev, int super_format, int super_mi
         rdev->in_sync = 0;
         rdev->data_offset = 0;
         atomic_set(&rdev->nr_pending, 0);
+        atomic_set(&rdev->read_errors, 0);
 
         size = rdev->bdev->bd_inode->i_size >> BLOCK_SIZE_BITS;
         if (!size) {