diff --git a/drivers/md/md.c b/drivers/md/md.c
index 46b3a044eadf41166a60cab6f10153fd1e75f09f..cb20d0b0555adee7c12d5e643a65d142f7f054e0 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2087,6 +2087,7 @@ static void sync_sbs(mddev_t * mddev, int nospares)
/* First make sure individual recovery_offsets are correct */
list_for_each_entry(rdev, &mddev->disks, same_set) {
if (rdev->raid_disk >= 0 &&
+ mddev->delta_disks >= 0 &&
!test_bit(In_sync, &rdev->flags) &&
mddev->curr_resync_completed > rdev->recovery_offset)
rdev->recovery_offset = mddev->curr_resync_completed;
@@ -3001,6 +3002,9 @@ level_store(mddev_t *mddev, const char *buf, size_t len)
return -EINVAL;
}
+ list_for_each_entry(rdev, &mddev->disks, same_set)
+ rdev->new_raid_disk = rdev->raid_disk;
+
/* ->takeover must set new_* and/or delta_disks
* if it succeeds, and may set them when it fails.
*/
@@ -3051,13 +3055,35 @@ level_store(mddev_t *mddev, const char *buf, size_t len)
mddev->safemode = 0;
}
- module_put(mddev->pers->owner);
- /* Invalidate devices that are now superfluous */
- list_for_each_entry(rdev, &mddev->disks, same_set)
- if (rdev->raid_disk >= mddev->raid_disks) {
- rdev->raid_disk = -1;
+ list_for_each_entry(rdev, &mddev->disks, same_set) {
+ char nm[20];
+ if (rdev->raid_disk < 0)
+ continue;
+ if (rdev->new_raid_disk > mddev->raid_disks)
+ rdev->new_raid_disk = -1;
+ if (rdev->new_raid_disk == rdev->raid_disk)
+ continue;
+ sprintf(nm, "rd%d", rdev->raid_disk);
+ sysfs_remove_link(&mddev->kobj, nm);
+ }
+ list_for_each_entry(rdev, &mddev->disks, same_set) {
+ if (rdev->raid_disk < 0)
+ continue;
+ if (rdev->new_raid_disk == rdev->raid_disk)
+ continue;
+ rdev->raid_disk = rdev->new_raid_disk;
+ if (rdev->raid_disk < 0)
clear_bit(In_sync, &rdev->flags);
+ else {
+ char nm[20];
+ sprintf(nm, "rd%d", rdev->raid_disk);
+ if(sysfs_create_link(&mddev->kobj, &rdev->kobj, nm))
+ printk("md: cannot register %s for %s after level change\n",
+ nm, mdname(mddev));
}
+ }
+
+ module_put(mddev->pers->owner);
mddev->pers = pers;
mddev->private = priv;
strlcpy(mddev->clevel, pers->name, sizeof(mddev->clevel));
@@ -5895,6 +5921,7 @@ static int md_open(struct block_device *bdev, fmode_t mode)
atomic_inc(&mddev->openers);
mutex_unlock(&mddev->open_mutex);
+ check_disk_size_change(mddev->gendisk, bdev);
out:
return err;
}
@@ -6846,6 +6873,7 @@ void md_do_sync(mddev_t *mddev)
rcu_read_lock();
list_for_each_entry_rcu(rdev, &mddev->disks, same_set)
if (rdev->raid_disk >= 0 &&
+ mddev->delta_disks >= 0 &&
!test_bit(Faulty, &rdev->flags) &&
!test_bit(In_sync, &rdev->flags) &&
rdev->recovery_offset < mddev->curr_resync)
diff --git a/drivers/md/md.h b/drivers/md/md.h
index 7ab5ea155452c5b745041e05c155df0ded2dd2c4..10597bfec0001c6ec3d732cab348ba459ee89a1a 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -78,6 +78,9 @@ struct mdk_rdev_s
int desc_nr; /* descriptor index in the superblock */
int raid_disk; /* role of device in array */
+ int new_raid_disk; /* role that the device will have in
+ * the array after a level-change completes.
+ */
int saved_raid_disk; /* role that device used to have in the
* array and could again if we did a partial
* resync from the bitmap
diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index e70f004c99e8b2bf146de202079f763022a048c2..563abed5a2cb73b68cc86d4230b8e1ab0a510b61 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -173,9 +173,11 @@ static int create_strip_zones(mddev_t *mddev, raid0_conf_t **private_conf)
list_for_each_entry(rdev1, &mddev->disks, same_set) {
int j = rdev1->raid_disk;
- if (mddev->level == 10)
+ if (mddev->level == 10) {
/* taking over a raid10-n2 array */
j /= 2;
+ rdev1->new_raid_disk = j;
+ }
if (j < 0 || j >= mddev->raid_disks) {
printk(KERN_ERR "md/raid0:%s: bad disk number %d - "
@@ -361,12 +363,6 @@ static int raid0_run(mddev_t *mddev)
mddev->private = conf;
}
conf = mddev->private;
- if (conf->scale_raid_disks) {
- int i;
- for (i=0; i < conf->strip_zone[0].nb_dev; i++)
- conf->devlist[i]->raid_disk /= conf->scale_raid_disks;
- /* FIXME update sysfs rd links */
- }
/* calculate array device size */
md_set_array_sectors(mddev, raid0_size(mddev, 0, 0));
@@ -573,7 +569,7 @@ static void raid0_status(struct seq_file *seq, mddev_t *mddev)
return;
}
-static void *raid0_takeover_raid5(mddev_t *mddev)
+static void *raid0_takeover_raid45(mddev_t *mddev)
{
mdk_rdev_t *rdev;
raid0_conf_t *priv_conf;
@@ -596,6 +592,7 @@ static void *raid0_takeover_raid5(mddev_t *mddev)
/* Set new parameters */
mddev->new_level = 0;
+ mddev->new_layout = 0;
mddev->new_chunk_sectors = mddev->chunk_sectors;
mddev->raid_disks--;
mddev->delta_disks = -1;
@@ -635,6 +632,7 @@ static void *raid0_takeover_raid10(mddev_t *mddev)
/* Set new parameters */
mddev->new_level = 0;
+ mddev->new_layout = 0;
mddev->new_chunk_sectors = mddev->chunk_sectors;
mddev->delta_disks = - mddev->raid_disks / 2;
mddev->raid_disks += mddev->delta_disks;
@@ -643,19 +641,22 @@ static void *raid0_takeover_raid10(mddev_t *mddev)
mddev->recovery_cp = MaxSector;
create_strip_zones(mddev, &priv_conf);
- priv_conf->scale_raid_disks = 2;
return priv_conf;
}
static void *raid0_takeover(mddev_t *mddev)
{
/* raid0 can take over:
+ * raid4 - if all data disks are active.
* raid5 - providing it is Raid4 layout and one disk is faulty
* raid10 - assuming we have all necessary active disks
*/
+ if (mddev->level == 4)
+ return raid0_takeover_raid45(mddev);
+
if (mddev->level == 5) {
if (mddev->layout == ALGORITHM_PARITY_N)
- return raid0_takeover_raid5(mddev);
+ return raid0_takeover_raid45(mddev);
printk(KERN_ERR "md/raid0:%s: Raid can only takeover Raid5 with layout: %d\n",
mdname(mddev), ALGORITHM_PARITY_N);
diff --git a/drivers/md/raid0.h b/drivers/md/raid0.h
index d724e664ca4dace9fa27fee815d84d6b7e40d946..91f8e876ee64516949ddad76b374bc657fd1879c 100644
--- a/drivers/md/raid0.h
+++ b/drivers/md/raid0.h
@@ -13,9 +13,6 @@ struct raid0_private_data
struct strip_zone *strip_zone;
mdk_rdev_t **devlist; /* lists of rdevs, pointed to by strip_zone->dev */
int nr_strip_zones;
- int scale_raid_disks; /* divide rdev->raid_disks by this in run()
- * to handle conversion from raid10
- */
};
typedef struct raid0_private_data raid0_conf_t;
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 03724992cdf20ea8ed46aaf2aee29ef845f29c54..42e64e4e5e2503fb4b81c12ac6706932f4397ba4 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -1482,14 +1482,14 @@ static void fix_read_error(conf_t *conf, mddev_t *mddev, r10bio_t *r10_bio)
int sectors = r10_bio->sectors;
mdk_rdev_t*rdev;
int max_read_errors = atomic_read(&mddev->max_corr_read_errors);
+ int d = r10_bio->devs[r10_bio->read_slot].devnum;
rcu_read_lock();
- {
- int d = r10_bio->devs[r10_bio->read_slot].devnum;
+ rdev = rcu_dereference(conf->mirrors[d].rdev);
+ if (rdev) { /* If rdev is not NULL */
char b[BDEVNAME_SIZE];
int cur_read_error_count = 0;
- rdev = rcu_dereference(conf->mirrors[d].rdev);
bdevname(rdev->bdev, b);
if (test_bit(Faulty, &rdev->flags)) {
@@ -1530,7 +1530,7 @@ static void fix_read_error(conf_t *conf, mddev_t *mddev, r10bio_t *r10_bio)
rcu_read_lock();
do {
- int d = r10_bio->devs[sl].devnum;
+ d = r10_bio->devs[sl].devnum;
rdev = rcu_dereference(conf->mirrors[d].rdev);
if (rdev &&
test_bit(In_sync, &rdev->flags)) {
@@ -1564,7 +1564,7 @@ static void fix_read_error(conf_t *conf, mddev_t *mddev, r10bio_t *r10_bio)
rcu_read_lock();
while (sl != r10_bio->read_slot) {
char b[BDEVNAME_SIZE];
- int d;
+
if (sl==0)
sl = conf->copies;
sl--;
@@ -1601,7 +1601,7 @@ static void fix_read_error(conf_t *conf, mddev_t *mddev, r10bio_t *r10_bio)
}
sl = start;
while (sl != r10_bio->read_slot) {
- int d;
+
if (sl==0)
sl = conf->copies;
sl--;
@@ -2161,22 +2161,22 @@ static conf_t *setup_conf(mddev_t *mddev)
sector_t stride, size;
int err = -EINVAL;
- if (mddev->chunk_sectors < (PAGE_SIZE >> 9) ||
- !is_power_of_2(mddev->chunk_sectors)) {
+ if (mddev->new_chunk_sectors < (PAGE_SIZE >> 9) ||
+ !is_power_of_2(mddev->new_chunk_sectors)) {
printk(KERN_ERR "md/raid10:%s: chunk size must be "
"at least PAGE_SIZE(%ld) and be a power of 2.\n",
mdname(mddev), PAGE_SIZE);
goto out;
}
- nc = mddev->layout & 255;
- fc = (mddev->layout >> 8) & 255;
- fo = mddev->layout & (1<<16);
+ nc = mddev->new_layout & 255;
+ fc = (mddev->new_layout >> 8) & 255;
+ fo = mddev->new_layout & (1<<16);
if ((nc*fc) <2 || (nc*fc) > mddev->raid_disks ||
- (mddev->layout >> 17)) {
+ (mddev->new_layout >> 17)) {
printk(KERN_ERR "md/raid10:%s: unsupported raid10 layout: 0x%8x\n",
- mdname(mddev), mddev->layout);
+ mdname(mddev), mddev->new_layout);
goto out;
}
@@ -2241,7 +2241,6 @@ static conf_t *setup_conf(mddev_t *mddev)
if (!conf->thread)
goto out;
- conf->scale_disks = 0;
conf->mddev = mddev;
return conf;
@@ -2300,11 +2299,6 @@ static int run(mddev_t *mddev)
if (disk_idx >= conf->raid_disks
|| disk_idx < 0)
continue;
- if (conf->scale_disks) {
- disk_idx *= conf->scale_disks;
- rdev->raid_disk = disk_idx;
- /* MOVE 'rd%d' link !! */
- }
disk = conf->mirrors + disk_idx;
disk->rdev = rdev;
@@ -2435,26 +2429,22 @@ static void *raid10_takeover_raid0(mddev_t *mddev)
return ERR_PTR(-EINVAL);
}
- /* Update slot numbers to obtain
- * degraded raid10 with missing mirrors
- */
- list_for_each_entry(rdev, &mddev->disks, same_set) {
- rdev->raid_disk *= 2;
- }
-
/* Set new parameters */
mddev->new_level = 10;
/* new layout: far_copies = 1, near_copies = 2 */
mddev->new_layout = (1<<8) + 2;
mddev->new_chunk_sectors = mddev->chunk_sectors;
mddev->delta_disks = mddev->raid_disks;
- mddev->degraded = mddev->raid_disks;
mddev->raid_disks *= 2;
/* make sure it will be not marked as dirty */
mddev->recovery_cp = MaxSector;
conf = setup_conf(mddev);
- conf->scale_disks = 2;
+ if (!IS_ERR(conf))
+ list_for_each_entry(rdev, &mddev->disks, same_set)
+ if (rdev->raid_disk >= 0)
+ rdev->new_raid_disk = rdev->raid_disk * 2;
+
return conf;
}
diff --git a/drivers/md/raid10.h b/drivers/md/raid10.h
index 3824a087e17c65efe0ee327772f7fa699fb41f22..2316ac2e8e218c6a97c96ebd35d99172e0bcb4fc 100644
--- a/drivers/md/raid10.h
+++ b/drivers/md/raid10.h
@@ -38,11 +38,6 @@ struct r10_private_data_s {
int chunk_shift; /* shift from chunks to sectors */
sector_t chunk_mask;
- int scale_disks; /* When starting array, multiply
- * each ->raid_disk by this.
- * Need for raid0->raid10 migration
- */
-
struct list_head retry_list;
/* queue pending writes and submit them on unplug */
struct bio_list pending_bio_list;
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index d2c0f94fa37d7a708b1c6854e7be3b1d3b60162f..96c690279fc6b58c7147c5860bf16417baa2149e 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -277,12 +277,13 @@ static struct stripe_head *get_free_stripe(raid5_conf_t *conf)
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);