diff options
| -rw-r--r-- | drivers/md/raid5.c | 75 |
1 files changed, 71 insertions, 4 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index f972a94bbc32..d4b233c25f2e 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -366,6 +366,73 @@ static struct stripe_head *__find_stripe(raid5_conf_t *conf, sector_t sector, return NULL; } +/* + * Need to check if array has failed when deciding whether to: + * - start an array + * - remove non-faulty devices + * - add a spare + * - allow a reshape + * This determination is simple when no reshape is happening. + * However if there is a reshape, we need to carefully check + * both the before and after sections. + * This is because some failed devices may only affect one + * of the two sections, and some non-in_sync devices may + * be insync in the section most affected by failed devices. + */ +static int has_failed(raid5_conf_t *conf) +{ + int degraded; + int i; + if (conf->mddev->reshape_position == MaxSector) + return conf->mddev->degraded > conf->max_degraded; + + rcu_read_lock(); + degraded = 0; + for (i = 0; i < conf->previous_raid_disks; i++) { + mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev); + if (!rdev || test_bit(Faulty, &rdev->flags)) + degraded++; + else if (test_bit(In_sync, &rdev->flags)) + ; + else + /* not in-sync or faulty. + * If the reshape increases the number of devices, + * this is being recovered by the reshape, so + * this 'previous' section is not in_sync. + * If the number of devices is being reduced however, + * the device can only be part of the array if + * we are reverting a reshape, so this section will + * be in-sync. + */ + if (conf->raid_disks >= conf->previous_raid_disks) + degraded++; + } + rcu_read_unlock(); + if (degraded > conf->max_degraded) + return 1; + rcu_read_lock(); + degraded = 0; + for (i = 0; i < conf->raid_disks; i++) { + mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev); + if (!rdev || test_bit(Faulty, &rdev->flags)) + degraded++; + else if (test_bit(In_sync, &rdev->flags)) + ; + else + /* not in-sync or faulty. + * If reshape increases the number of devices, this + * section has already been recovered, else it + * almost certainly hasn't. + */ + if (conf->raid_disks <= conf->previous_raid_disks) + degraded++; + } + rcu_read_unlock(); + if (degraded > conf->max_degraded) + return 1; + return 0; +} + static void unplug_slaves(mddev_t *mddev); static void raid5_unplug_device(struct request_queue *q); @@ -5006,7 +5073,7 @@ static int run(mddev_t *mddev) mddev->degraded = (max(conf->raid_disks, conf->previous_raid_disks) - working_disks); - if (mddev->degraded > conf->max_degraded) { + if (has_failed(conf)) { printk(KERN_ERR "md/raid:%s: not enough operational devices" " (%d/%d failed)\n", mdname(mddev), mddev->degraded, conf->raid_disks); @@ -5244,7 +5311,7 @@ static int raid5_remove_disk(mddev_t *mddev, int number) * isn't possible. */ if (!test_bit(Faulty, &rdev->flags) && - mddev->degraded <= conf->max_degraded && + !has_failed(conf) && number < conf->raid_disks) { err = -EBUSY; goto abort; @@ -5272,7 +5339,7 @@ static int raid5_add_disk(mddev_t *mddev, mdk_rdev_t *rdev) int first = 0; int last = conf->raid_disks - 1; - if (mddev->degraded > conf->max_degraded) + if (has_failed(conf)) /* no point adding a device */ return -EINVAL; @@ -5364,7 +5431,7 @@ static int check_reshape(mddev_t *mddev) if (mddev->bitmap) /* Cannot grow a bitmap yet */ return -EBUSY; - if (mddev->degraded > conf->max_degraded) + if (has_failed(conf)) return -EINVAL; if (mddev->delta_disks < 0) { /* We might be able to shrink, but the devices must |