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author | NeilBrown <neilb@suse.de> | 2011-12-23 10:17:50 +1100 |
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committer | NeilBrown <neilb@suse.de> | 2011-12-23 10:17:50 +1100 |
commit | 908f4fbd265733310c17ecc906299846b5dac44a (patch) | |
tree | 71e364c57887213431143e6fd1296e8433cc6293 | |
parent | 2e61ebbcc45438899235d7a39f17291cb24e746c (diff) | |
download | linux-3.10-908f4fbd265733310c17ecc906299846b5dac44a.tar.gz linux-3.10-908f4fbd265733310c17ecc906299846b5dac44a.tar.bz2 linux-3.10-908f4fbd265733310c17ecc906299846b5dac44a.zip |
md/raid5: be more thorough in calculating 'degraded' value.
When an array is being reshaped to change the number of devices,
the two halves can be differently degraded. e.g. one could be
missing a device and the other not.
So we need to be more careful about calculating the 'degraded'
attribute.
Instead of just inc/dec at appropriate times, perform a full
re-calculation examining both possible cases. This doesn't happen
often so it not a big cost, and we already have most of the code to
do it.
Signed-off-by: NeilBrown <neilb@suse.de>
-rw-r--r-- | drivers/md/raid5.c | 63 |
1 files changed, 33 insertions, 30 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 858fdbb7eb0..a68c49250ed 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -370,12 +370,10 @@ static struct stripe_head *__find_stripe(struct r5conf *conf, sector_t sector, * 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(struct r5conf *conf) +static int calc_degraded(struct r5conf *conf) { - int degraded; + int degraded, degraded2; int i; - if (conf->mddev->reshape_position == MaxSector) - return conf->mddev->degraded > conf->max_degraded; rcu_read_lock(); degraded = 0; @@ -399,14 +397,14 @@ static int has_failed(struct r5conf *conf) degraded++; } rcu_read_unlock(); - if (degraded > conf->max_degraded) - return 1; + if (conf->raid_disks == conf->previous_raid_disks) + return degraded; rcu_read_lock(); - degraded = 0; + degraded2 = 0; for (i = 0; i < conf->raid_disks; i++) { struct md_rdev *rdev = rcu_dereference(conf->disks[i].rdev); if (!rdev || test_bit(Faulty, &rdev->flags)) - degraded++; + degraded2++; else if (test_bit(In_sync, &rdev->flags)) ; else @@ -416,9 +414,22 @@ static int has_failed(struct r5conf *conf) * almost certainly hasn't. */ if (conf->raid_disks <= conf->previous_raid_disks) - degraded++; + degraded2++; } rcu_read_unlock(); + if (degraded2 > degraded) + return degraded2; + return degraded; +} + +static int has_failed(struct r5conf *conf) +{ + int degraded; + + if (conf->mddev->reshape_position == MaxSector) + return conf->mddev->degraded > conf->max_degraded; + + degraded = calc_degraded(conf); if (degraded > conf->max_degraded) return 1; return 0; @@ -1724,18 +1735,15 @@ static void error(struct mddev *mddev, struct md_rdev *rdev) { char b[BDEVNAME_SIZE]; struct r5conf *conf = mddev->private; + unsigned long flags; pr_debug("raid456: error called\n"); - if (test_and_clear_bit(In_sync, &rdev->flags)) { - unsigned long flags; - spin_lock_irqsave(&conf->device_lock, flags); - mddev->degraded++; - spin_unlock_irqrestore(&conf->device_lock, flags); - /* - * if recovery was running, make sure it aborts. - */ - set_bit(MD_RECOVERY_INTR, &mddev->recovery); - } + spin_lock_irqsave(&conf->device_lock, flags); + clear_bit(In_sync, &rdev->flags); + mddev->degraded = calc_degraded(conf); + spin_unlock_irqrestore(&conf->device_lock, flags); + set_bit(MD_RECOVERY_INTR, &mddev->recovery); + set_bit(Blocked, &rdev->flags); set_bit(Faulty, &rdev->flags); set_bit(MD_CHANGE_DEVS, &mddev->flags); @@ -4852,8 +4860,7 @@ static int run(struct mddev *mddev) dirty_parity_disks++; } - mddev->degraded = (max(conf->raid_disks, conf->previous_raid_disks) - - working_disks); + mddev->degraded = calc_degraded(conf); if (has_failed(conf)) { printk(KERN_ERR "md/raid:%s: not enough operational devices" @@ -5025,7 +5032,7 @@ static int raid5_spare_active(struct mddev *mddev) } } spin_lock_irqsave(&conf->device_lock, flags); - mddev->degraded -= count; + mddev->degraded = calc_degraded(conf); spin_unlock_irqrestore(&conf->device_lock, flags); print_raid5_conf(conf); return count; @@ -5286,8 +5293,7 @@ static int raid5_start_reshape(struct mddev *mddev) * pre and post number of devices. */ spin_lock_irqsave(&conf->device_lock, flags); - mddev->degraded += (conf->raid_disks - conf->previous_raid_disks) - - added_devices; + mddev->degraded = calc_degraded(conf); spin_unlock_irqrestore(&conf->device_lock, flags); } mddev->raid_disks = conf->raid_disks; @@ -5356,12 +5362,9 @@ static void raid5_finish_reshape(struct mddev *mddev) revalidate_disk(mddev->gendisk); } else { int d; - mddev->degraded = conf->raid_disks; - for (d = 0; d < conf->raid_disks ; d++) - if (conf->disks[d].rdev && - test_bit(In_sync, - &conf->disks[d].rdev->flags)) - mddev->degraded--; + spin_lock_irq(&conf->device_lock); + mddev->degraded = calc_degraded(conf); + spin_unlock_irq(&conf->device_lock); for (d = conf->raid_disks ; d < conf->raid_disks - mddev->delta_disks; d++) { |