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@xxxxxxx>
### Diffstat output
./drivers/md/md.c | 1 +
./drivers/md/raid5.c | 25 +++++++++++++++++--------
./include/linux/raid/md_k.h | 3 +++
3 files changed, 21 insertions(+), 8 deletions(-)
diff ./drivers/md/md.c~current~ ./drivers/md/md.c
--- ./drivers/md/md.c~current~ 2005-10-14 12:16:38.000000000 +1000
+++ ./drivers/md/md.c 2005-10-14 12:16:55.000000000 +1000
@@ -1582,6 +1582,7 @@ static mdk_rdev_t *md_import_device(dev_
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) {
diff ./drivers/md/raid5.c~current~ ./drivers/md/raid5.c
--- ./drivers/md/raid5.c~current~ 2005-10-14 12:16:39.000000000 +1000
+++ ./drivers/md/raid5.c 2005-10-14 12:16:55.000000000 +1000
@@ -420,21 +420,29 @@ static int raid5_end_read_request(struct
clear_bit(R5_ReadError, &sh->dev[i].flags);
clear_bit(R5_ReWrite, &sh->dev[i].flags);
}
+ if (atomic_read(&conf->disks[i].rdev->read_errors))
+ atomic_set(&conf->disks[i].rdev->read_errors, 0);
} else {
+ int retry = 0;
clear_bit(R5_UPTODATE, &sh->dev[i].flags);
- if (conf->mddev->degraded) {
+ atomic_inc(&conf->disks[i].rdev->read_errors);
+ if (conf->mddev->degraded)
printk("R5: read error not correctable.\n");
- clear_bit(R5_ReadError, &sh->dev[i].flags);
- clear_bit(R5_ReWrite, &sh->dev[i].flags);
- md_error(conf->mddev, conf->disks[i].rdev);
- } else if (test_bit(R5_ReWrite, &sh->dev[i].flags)) {
+ else if (test_bit(R5_ReWrite, &sh->dev[i].flags))
/* Oh, no!!! */
printk("R5: read error NOT corrected!!\n");
+ else if (atomic_read(&conf->disks[i].rdev->read_errors)
+ > conf->max_nr_stripes)
+ printk("raid5: Too many read errors, failing device.\n");
+ else
+ retry = 1;
+ if (retry)
+ set_bit(R5_ReadError, &sh->dev[i].flags);
+ else {
clear_bit(R5_ReadError, &sh->dev[i].flags);
clear_bit(R5_ReWrite, &sh->dev[i].flags);
md_error(conf->mddev, conf->disks[i].rdev);
- } else
- set_bit(R5_ReadError, &sh->dev[i].flags);
+ }
}
rdev_dec_pending(conf->disks[i].rdev, conf->mddev);
#if 0
@@ -1328,7 +1336,8 @@ static void handle_stripe(struct stripe_
/* If the failed drive is just a ReadError, then we might need to progress
* the repair/check process
*/
- if (failed == 1 && test_bit(R5_ReadError, &sh->dev[failed_num].flags)
+ if (failed == 1 && ! conf->mddev->ro &&
+ test_bit(R5_ReadError, &sh->dev[failed_num].flags)
&& !test_bit(R5_LOCKED, &sh->dev[failed_num].flags)
&& test_bit(R5_UPTODATE, &sh->dev[failed_num].flags)
) {
diff ./include/linux/raid/md_k.h~current~ ./include/linux/raid/md_k.h
--- ./include/linux/raid/md_k.h~current~ 2005-10-14 12:16:39.000000000 +1000
+++ ./include/linux/raid/md_k.h 2005-10-14 12:16:55.000000000 +1000
@@ -134,6 +134,9 @@ struct mdk_rdev_s
* only maintained for arrays that
* support hot removal
*/
+ atomic_t read_errors; /* number of consecutive read errors that
+ * we have tried to ignore.
+ */
};
typedef struct mdk_personality_s mdk_personality_t;
-
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
