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path: root/drivers/md/raid5.c
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Diffstat (limited to 'drivers/md/raid5.c')
-rw-r--r--drivers/md/raid5.c150
1 files changed, 122 insertions, 28 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index d2c0f94fa37d..96c690279fc6 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);
generated by cgit v1.2.3 (git 2.0.4) at 2024-11-06 16:14:03 +0000