md: Fix handling of raid5 array which is being reshaped to fewer devices.
When a raid5 (or raid6) array is being reshaped to have fewer devices,
conf->raid_disks is the latter and hence smaller number of devices.
However sometimes we want to use a number which is the total number of
currently required devices - the larger of the 'old' and 'new' sizes.
Before we implemented reducing the number of devices, this was always
'new' i.e. ->raid_disks.
Now we need max(raid_disks, previous_raid_disks) in those places.
This particularly affects assembling an array that was shutdown while
in the middle of a reshape to fewer devices.
md.c needs a similar fix when interpreting the md metadata.
Signed-off-by: NeilBrown <neilb@suse.de>
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index d4ce51b..c4366c9 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -1238,22 +1238,22 @@
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) + (conf->raid_disks-1)*sizeof(struct r5dev));
+ memset(sh, 0, sizeof(*sh) + (disks-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, conf->raid_disks)) {
- shrink_buffers(sh, conf->raid_disks);
+ if (grow_buffers(sh, disks)) {
+ shrink_buffers(sh, disks);
kmem_cache_free(conf->slab_cache, sh);
return 0;
}
- sh->disks = conf->raid_disks;
/* we just created an active stripe so... */
atomic_set(&sh->count, 1);
atomic_inc(&conf->active_stripes);
@@ -1265,7 +1265,7 @@
static int grow_stripes(raid5_conf_t *conf, int num)
{
struct kmem_cache *sc;
- int devs = conf->raid_disks;
+ int devs = max(conf->raid_disks, conf->previous_raid_disks);
sprintf(conf->cache_name[0],
"raid%d-%s", conf->level, mdname(conf->mddev));
@@ -3540,9 +3540,10 @@
{
raid5_conf_t *conf = mddev->private;
int i;
+ int devs = max(conf->raid_disks, conf->previous_raid_disks);
rcu_read_lock();
- for (i = 0; i < conf->raid_disks; i++) {
+ for (i = 0; i < devs; i++) {
mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev);
if (rdev && !test_bit(Faulty, &rdev->flags) && atomic_read(&rdev->nr_pending)) {
struct request_queue *r_queue = bdev_get_queue(rdev->bdev);
@@ -4562,13 +4563,9 @@
if (!sectors)
sectors = mddev->dev_sectors;
- if (!raid_disks) {
+ if (!raid_disks)
/* size is defined by the smallest of previous and new size */
- if (conf->raid_disks < conf->previous_raid_disks)
- raid_disks = conf->raid_disks;
- else
- raid_disks = conf->previous_raid_disks;
- }
+ raid_disks = min(conf->raid_disks, conf->previous_raid_disks);
sectors &= ~((sector_t)mddev->chunk_sectors - 1);
sectors &= ~((sector_t)mddev->new_chunk_sectors - 1);
@@ -4669,7 +4666,7 @@
}
per_cpu_ptr(conf->percpu, cpu)->spare_page = spare_page;
}
- scribble = kmalloc(scribble_len(conf->raid_disks), GFP_KERNEL);
+ scribble = kmalloc(conf->scribble_len, GFP_KERNEL);
if (!scribble) {
err = -ENOMEM;
break;
@@ -4690,7 +4687,7 @@
static raid5_conf_t *setup_conf(mddev_t *mddev)
{
raid5_conf_t *conf;
- int raid_disk, memory;
+ int raid_disk, memory, max_disks;
mdk_rdev_t *rdev;
struct disk_info *disk;
@@ -4740,13 +4737,14 @@
conf->bypass_threshold = BYPASS_THRESHOLD;
conf->raid_disks = mddev->raid_disks;
- conf->scribble_len = scribble_len(conf->raid_disks);
if (mddev->reshape_position == MaxSector)
conf->previous_raid_disks = mddev->raid_disks;
else
conf->previous_raid_disks = mddev->raid_disks - mddev->delta_disks;
+ max_disks = max(conf->raid_disks, conf->previous_raid_disks);
+ conf->scribble_len = scribble_len(max_disks);
- conf->disks = kzalloc(conf->raid_disks * sizeof(struct disk_info),
+ conf->disks = kzalloc(max_disks * sizeof(struct disk_info),
GFP_KERNEL);
if (!conf->disks)
goto abort;
@@ -4764,7 +4762,7 @@
list_for_each_entry(rdev, &mddev->disks, same_set) {
raid_disk = rdev->raid_disk;
- if (raid_disk >= conf->raid_disks
+ if (raid_disk >= max_disks
|| raid_disk < 0)
continue;
disk = conf->disks + raid_disk;
@@ -4796,7 +4794,7 @@
}
memory = conf->max_nr_stripes * (sizeof(struct stripe_head) +
- conf->raid_disks * ((sizeof(struct bio) + PAGE_SIZE))) / 1024;
+ max_disks * ((sizeof(struct bio) + PAGE_SIZE))) / 1024;
if (grow_stripes(conf, conf->max_nr_stripes)) {
printk(KERN_ERR
"raid5: couldn't allocate %dkB for buffers\n", memory);
@@ -4921,7 +4919,8 @@
test_bit(In_sync, &rdev->flags))
working_disks++;
- mddev->degraded = conf->raid_disks - working_disks;
+ mddev->degraded = (max(conf->raid_disks, conf->previous_raid_disks)
+ - working_disks);
if (mddev->degraded > conf->max_degraded) {
printk(KERN_ERR "raid5: not enough operational devices for %s"