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author | Jiri Kosina <jkosina@suse.cz> | 2010-08-04 15:14:38 +0200 |
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committer | Jiri Kosina <jkosina@suse.cz> | 2010-08-04 15:14:38 +0200 |
commit | d790d4d583aeaed9fc6f8a9f4d9f8ce6b1c15c7f (patch) | |
tree | 854ab394486288d40fa8179cbfaf66e8bdc44b0f /drivers/md/raid5.c | |
parent | 73b2c7165b76b20eb1290e7efebc33cfd21db1ca (diff) | |
parent | 3a09b1be53d23df780a0cd0e4087a05e2ca4a00c (diff) | |
download | op-kernel-dev-d790d4d583aeaed9fc6f8a9f4d9f8ce6b1c15c7f.zip op-kernel-dev-d790d4d583aeaed9fc6f8a9f4d9f8ce6b1c15c7f.tar.gz |
Merge branch 'master' into for-next
Diffstat (limited to 'drivers/md/raid5.c')
-rw-r--r-- | drivers/md/raid5.c | 150 |
1 files changed, 122 insertions, 28 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index d2c0f94..96c6902 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -277,12 +277,13 @@ out: return sh; } -static void shrink_buffers(struct stripe_head *sh, int num) +static void shrink_buffers(struct stripe_head *sh) { struct page *p; int i; + int num = sh->raid_conf->pool_size; - for (i=0; i<num ; i++) { + for (i = 0; i < num ; i++) { p = sh->dev[i].page; if (!p) continue; @@ -291,11 +292,12 @@ static void shrink_buffers(struct stripe_head *sh, int num) } } -static int grow_buffers(struct stripe_head *sh, int num) +static int grow_buffers(struct stripe_head *sh) { int i; + int num = sh->raid_conf->pool_size; - for (i=0; i<num; i++) { + for (i = 0; i < num; i++) { struct page *page; if (!(page = alloc_page(GFP_KERNEL))) { @@ -364,6 +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); @@ -1240,19 +1309,18 @@ static void raid_run_ops(struct stripe_head *sh, unsigned long ops_request) static int grow_one_stripe(raid5_conf_t *conf) { struct stripe_head *sh; - int disks = max(conf->raid_disks, conf->previous_raid_disks); sh = kmem_cache_alloc(conf->slab_cache, GFP_KERNEL); if (!sh) return 0; - memset(sh, 0, sizeof(*sh) + (disks-1)*sizeof(struct r5dev)); + memset(sh, 0, sizeof(*sh) + (conf->pool_size-1)*sizeof(struct r5dev)); sh->raid_conf = conf; spin_lock_init(&sh->lock); #ifdef CONFIG_MULTICORE_RAID456 init_waitqueue_head(&sh->ops.wait_for_ops); #endif - if (grow_buffers(sh, disks)) { - shrink_buffers(sh, disks); + if (grow_buffers(sh)) { + shrink_buffers(sh); kmem_cache_free(conf->slab_cache, sh); return 0; } @@ -1468,7 +1536,7 @@ static int drop_one_stripe(raid5_conf_t *conf) if (!sh) return 0; BUG_ON(atomic_read(&sh->count)); - shrink_buffers(sh, conf->pool_size); + shrink_buffers(sh); kmem_cache_free(conf->slab_cache, sh); atomic_dec(&conf->active_stripes); return 1; @@ -2963,7 +3031,6 @@ static void handle_stripe5(struct stripe_head *sh) mdk_rdev_t *rdev; dev = &sh->dev[i]; - clear_bit(R5_Insync, &dev->flags); pr_debug("check %d: state 0x%lx toread %p read %p write %p " "written %p\n", i, dev->flags, dev->toread, dev->read, @@ -3000,17 +3067,27 @@ static void handle_stripe5(struct stripe_head *sh) blocked_rdev = rdev; atomic_inc(&rdev->nr_pending); } - if (!rdev || !test_bit(In_sync, &rdev->flags)) { + clear_bit(R5_Insync, &dev->flags); + if (!rdev) + /* Not in-sync */; + else if (test_bit(In_sync, &rdev->flags)) + set_bit(R5_Insync, &dev->flags); + else { + /* could be in-sync depending on recovery/reshape status */ + if (sh->sector + STRIPE_SECTORS <= rdev->recovery_offset) + set_bit(R5_Insync, &dev->flags); + } + if (!test_bit(R5_Insync, &dev->flags)) { /* The ReadError flag will just be confusing now */ clear_bit(R5_ReadError, &dev->flags); clear_bit(R5_ReWrite, &dev->flags); } - if (!rdev || !test_bit(In_sync, &rdev->flags) - || test_bit(R5_ReadError, &dev->flags)) { + if (test_bit(R5_ReadError, &dev->flags)) + clear_bit(R5_Insync, &dev->flags); + if (!test_bit(R5_Insync, &dev->flags)) { s.failed++; s.failed_num = i; - } else - set_bit(R5_Insync, &dev->flags); + } } rcu_read_unlock(); @@ -3244,7 +3321,6 @@ static void handle_stripe6(struct stripe_head *sh) for (i=disks; i--; ) { mdk_rdev_t *rdev; dev = &sh->dev[i]; - clear_bit(R5_Insync, &dev->flags); pr_debug("check %d: state 0x%lx read %p write %p written %p\n", i, dev->flags, dev->toread, dev->towrite, dev->written); @@ -3282,18 +3358,28 @@ static void handle_stripe6(struct stripe_head *sh) blocked_rdev = rdev; atomic_inc(&rdev->nr_pending); } - if (!rdev || !test_bit(In_sync, &rdev->flags)) { + clear_bit(R5_Insync, &dev->flags); + if (!rdev) + /* Not in-sync */; + else if (test_bit(In_sync, &rdev->flags)) + set_bit(R5_Insync, &dev->flags); + else { + /* in sync if before recovery_offset */ + if (sh->sector + STRIPE_SECTORS <= rdev->recovery_offset) + set_bit(R5_Insync, &dev->flags); + } + if (!test_bit(R5_Insync, &dev->flags)) { /* The ReadError flag will just be confusing now */ clear_bit(R5_ReadError, &dev->flags); clear_bit(R5_ReWrite, &dev->flags); } - if (!rdev || !test_bit(In_sync, &rdev->flags) - || test_bit(R5_ReadError, &dev->flags)) { + if (test_bit(R5_ReadError, &dev->flags)) + clear_bit(R5_Insync, &dev->flags); + if (!test_bit(R5_Insync, &dev->flags)) { if (s.failed < 2) r6s.failed_num[s.failed] = i; s.failed++; - } else - set_bit(R5_Insync, &dev->flags); + } } rcu_read_unlock(); @@ -4971,8 +5057,10 @@ static int run(mddev_t *mddev) list_for_each_entry(rdev, &mddev->disks, same_set) { if (rdev->raid_disk < 0) continue; - if (test_bit(In_sync, &rdev->flags)) + if (test_bit(In_sync, &rdev->flags)) { working_disks++; + continue; + } /* This disc is not fully in-sync. However if it * just stored parity (beyond the recovery_offset), * when we don't need to be concerned about the @@ -5005,7 +5093,7 @@ 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); @@ -5207,6 +5295,7 @@ static int raid5_spare_active(mddev_t *mddev) for (i = 0; i < conf->raid_disks; i++) { tmp = conf->disks + i; if (tmp->rdev + && tmp->rdev->recovery_offset == MaxSector && !test_bit(Faulty, &tmp->rdev->flags) && !test_and_set_bit(In_sync, &tmp->rdev->flags)) { unsigned long flags; @@ -5242,7 +5331,7 @@ 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; @@ -5270,7 +5359,7 @@ 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; @@ -5362,7 +5451,7 @@ 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 @@ -5437,8 +5526,13 @@ static int raid5_start_reshape(mddev_t *mddev) /* Add some new drives, as many as will fit. * We know there are enough to make the newly sized array work. + * Don't add devices if we are reducing the number of + * devices in the array. This is because it is not possible + * to correctly record the "partially reconstructed" state of + * such devices during the reshape and confusion could result. */ - list_for_each_entry(rdev, &mddev->disks, same_set) + if (mddev->delta_disks >= 0) + list_for_each_entry(rdev, &mddev->disks, same_set) if (rdev->raid_disk < 0 && !test_bit(Faulty, &rdev->flags)) { if (raid5_add_disk(mddev, rdev) == 0) { @@ -5460,7 +5554,7 @@ static int raid5_start_reshape(mddev_t *mddev) } /* When a reshape changes the number of devices, ->degraded - * is measured against the large of the pre and post number of + * is measured against the larger of the pre and post number of * devices.*/ if (mddev->delta_disks > 0) { spin_lock_irqsave(&conf->device_lock, flags); |