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md/raid5: use bad-block log to improve handling of uncorrectable read errors. 

If we get an uncorrectable read error - record a bad block rather than
failing the device.
And if these errors (which may be due to known bad blocks) cause
recovery to be impossible, record a bad block on the recovering
devices, or abort the recovery.

As we might abort a recovery without failing a device we need to teach
RAID5 about recovery_disabled handling.

Signed-off-by: NeilBrown <neilb@suse.de>
This commit is contained in:
NeilBrown 2011-07-28 11:39:22 +10:00
parent 31c176ecdf
commit 7f0da59bdc
2 changed files with 53 additions and 8 deletions
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59
drivers/md/raid5.c
View File

@ -2232,9 +2232,18 @@ handle_failed_stripe(raid5_conf_t *conf, struct stripe_head *sh,
rcu_read_lock();
rdev = rcu_dereference(conf->disks[i].rdev);
if (rdev && test_bit(In_sync, &rdev->flags))
/* multiple read failures in one stripe */
md_error(conf->mddev, rdev);
atomic_inc(&rdev->nr_pending);
else
rdev = NULL;
rcu_read_unlock();
if (rdev) {
if (!rdev_set_badblocks(
rdev,
sh->sector,
STRIPE_SECTORS, 0))
md_error(conf->mddev, rdev);
rdev_dec_pending(rdev, conf->mddev);
}
}
spin_lock_irq(&conf->device_lock);
/* fail all writes first */
@ -2313,6 +2322,41 @@ handle_failed_stripe(raid5_conf_t *conf, struct stripe_head *sh,
md_wakeup_thread(conf->mddev->thread);
}
static void
handle_failed_sync(raid5_conf_t *conf, struct stripe_head *sh,
struct stripe_head_state *s)
{
int abort = 0;
int i;
md_done_sync(conf->mddev, STRIPE_SECTORS, 0);
clear_bit(STRIPE_SYNCING, &sh->state);
s->syncing = 0;
/* There is nothing more to do for sync/check/repair.
* For recover we need to record a bad block on all
* non-sync devices, or abort the recovery
*/
if (!test_bit(MD_RECOVERY_RECOVER, &conf->mddev->recovery))
return;
/* During recovery devices cannot be removed, so locking and
* refcounting of rdevs is not needed
*/
for (i = 0; i < conf->raid_disks; i++) {
mdk_rdev_t *rdev = conf->disks[i].rdev;
if (!rdev
|| test_bit(Faulty, &rdev->flags)
|| test_bit(In_sync, &rdev->flags))
continue;
if (!rdev_set_badblocks(rdev, sh->sector,
STRIPE_SECTORS, 0))
abort = 1;
}
if (abort) {
conf->recovery_disabled = conf->mddev->recovery_disabled;
set_bit(MD_RECOVERY_INTR, &conf->mddev->recovery);
}
}
/* fetch_block - checks the given member device to see if its data needs
* to be read or computed to satisfy a request.
*
@ -3067,11 +3111,8 @@ static void handle_stripe(struct stripe_head *sh)
*/
if (s.failed > conf->max_degraded && s.to_read+s.to_write+s.written)
handle_failed_stripe(conf, sh, &s, disks, &s.return_bi);
if (s.failed > conf->max_degraded && s.syncing) {
md_done_sync(conf->mddev, STRIPE_SECTORS, 0);
clear_bit(STRIPE_SYNCING, &sh->state);
s.syncing = 0;
}
if (s.failed > conf->max_degraded && s.syncing)
handle_failed_sync(conf, sh, &s);
/*
* might be able to return some write requests if the parity blocks
@ -4976,6 +5017,7 @@ static int raid5_remove_disk(mddev_t *mddev, int number)
* isn't possible.
*/
if (!test_bit(Faulty, &rdev->flags) &&
mddev->recovery_disabled != conf->recovery_disabled &&
!has_failed(conf) &&
number < conf->raid_disks) {
err = -EBUSY;
@ -5004,6 +5046,9 @@ static int raid5_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
int first = 0;
int last = conf->raid_disks - 1;
if (mddev->recovery_disabled == conf->recovery_disabled)
return -EBUSY;
if (has_failed(conf))
/* no point adding a device */
return -EINVAL;

2
drivers/md/raid5.h
View File

@ -399,7 +399,7 @@ struct raid5_private_data {
* (fresh device added).
* Cleared when a sync completes.
*/
int recovery_disabled;
/* per cpu variables */
struct raid5_percpu {
struct page *spare_page; /* Used when checking P/Q in raid6 */