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authorNeil Brown <neilb@cse.unsw.edu.au>2004-06-04 20:56:50 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2004-06-04 20:56:50 -0700
commitf6a0ebcab2093d6bad49949df0ab055eb47cc07c (patch)
tree9a653ab8a30a61ce735f46fabf113209907d40d9
parentf23b262d654bdf04a8d18b7f1d909930cc5695d6 (diff)
[PATCH] md: support reshaping raid1 arrays - adding or removing drives.
This allows the number of "raid_disks" in a raid1 to be changed. This requires allocating a new pool of "r1bio" structures which a different number of bios, suspending IO, and swapping the new pool in place of the old. (and a few other related changes). Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--drivers/md/md.c31
-rw-r--r--drivers/md/raid1.c163
-rw-r--r--include/linux/raid/md_k.h1
-rw-r--r--include/linux/raid/raid1.h16
4 files changed, 172 insertions, 39 deletions
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 456ed6b17cd8..77cd6e9f3acd 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2388,18 +2388,23 @@ static int set_array_info(mddev_t * mddev, mdu_array_info_t *info)
static int update_array_info(mddev_t *mddev, mdu_array_info_t *info)
{
int rv = 0;
+ int cnt = 0;
if (mddev->major_version != info->major_version ||
mddev->minor_version != info->minor_version ||
/* mddev->patch_version != info->patch_version || */
mddev->ctime != info->ctime ||
mddev->level != info->level ||
- mddev->raid_disks != info->raid_disks ||
mddev->layout != info->layout ||
!mddev->persistent != info->not_persistent||
mddev->chunk_size != info->chunk_size )
return -EINVAL;
- /* that leaves only size */
+ /* Check there is only one change */
+ if (mddev->size != info->size) cnt++;
+ if (mddev->raid_disks != info->raid_disks) cnt++;
+ if (cnt == 0) return 0;
+ if (cnt > 1) return -EINVAL;
+
if (mddev->size != info->size) {
mdk_rdev_t * rdev;
struct list_head *tmp;
@@ -2443,6 +2448,28 @@ static int update_array_info(mddev_t *mddev, mdu_array_info_t *info)
}
}
}
+ if (mddev->raid_disks != info->raid_disks) {
+ /* change the number of raid disks */
+ if (mddev->pers->reshape == NULL)
+ return -EINVAL;
+ if (info->raid_disks <= 0 ||
+ info->raid_disks >= mddev->max_disks)
+ return -EINVAL;
+ if (mddev->sync_thread)
+ return -EBUSY;
+ rv = mddev->pers->reshape(mddev, info->raid_disks);
+ if (!rv) {
+ struct block_device *bdev;
+
+ bdev = bdget_disk(mddev->gendisk, 0);
+ if (bdev) {
+ down(&bdev->bd_inode->i_sem);
+ i_size_write(bdev->bd_inode, mddev->array_size << 10);
+ up(&bdev->bd_inode->i_sem);
+ bdput(bdev);
+ }
+ }
+ }
md_update_sb(mddev);
return rv;
}
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 185c8dbc8d33..1b80c5b68f54 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -42,16 +42,17 @@ static void unplug_slaves(mddev_t *mddev);
static void * r1bio_pool_alloc(int gfp_flags, void *data)
{
- mddev_t *mddev = data;
+ struct pool_info *pi = data;
r1bio_t *r1_bio;
/* allocate a r1bio with room for raid_disks entries in the bios array */
- r1_bio = kmalloc(sizeof(r1bio_t) + sizeof(struct bio*)*mddev->raid_disks,
+ r1_bio = kmalloc(sizeof(r1bio_t) + sizeof(struct bio*)*pi->raid_disks,
gfp_flags);
if (r1_bio)
- memset(r1_bio, 0, sizeof(*r1_bio) + sizeof(struct bio*)*mddev->raid_disks);
+ memset(r1_bio, 0, sizeof(*r1_bio) +
+ sizeof(struct bio*) * pi->raid_disks);
else
- unplug_slaves(mddev);
+ unplug_slaves(pi->mddev);
return r1_bio;
}
@@ -69,22 +70,22 @@ static void r1bio_pool_free(void *r1_bio, void *data)
static void * r1buf_pool_alloc(int gfp_flags, void *data)
{
- conf_t *conf = data;
+ struct pool_info *pi = data;
struct page *page;
r1bio_t *r1_bio;
struct bio *bio;
int i, j;
- r1_bio = r1bio_pool_alloc(gfp_flags, conf->mddev);
+ r1_bio = r1bio_pool_alloc(gfp_flags, pi);
if (!r1_bio) {
- unplug_slaves(conf->mddev);
+ unplug_slaves(pi->mddev);
return NULL;
}
/*
* Allocate bios : 1 for reading, n-1 for writing
*/
- for (j = conf->raid_disks ; j-- ; ) {
+ for (j = pi->raid_disks ; j-- ; ) {
bio = bio_alloc(gfp_flags, RESYNC_PAGES);
if (!bio)
goto out_free_bio;
@@ -111,16 +112,16 @@ out_free_pages:
for ( ; i > 0 ; i--)
__free_page(bio->bi_io_vec[i-1].bv_page);
out_free_bio:
- while ( ++j < conf->raid_disks )
+ while ( ++j < pi->raid_disks )
bio_put(r1_bio->bios[j]);
- r1bio_pool_free(r1_bio, conf->mddev);
+ r1bio_pool_free(r1_bio, data);
return NULL;
}
static void r1buf_pool_free(void *__r1_bio, void *data)
{
+ struct pool_info *pi = data;
int i;
- conf_t *conf = data;
r1bio_t *r1bio = __r1_bio;
struct bio *bio = r1bio->bios[0];
@@ -128,10 +129,10 @@ static void r1buf_pool_free(void *__r1_bio, void *data)
__free_page(bio->bi_io_vec[i].bv_page);
bio->bi_io_vec[i].bv_page = NULL;
}
- for (i=0 ; i < conf->raid_disks; i++)
+ for (i=0 ; i < pi->raid_disks; i++)
bio_put(r1bio->bios[i]);
- r1bio_pool_free(r1bio, conf->mddev);
+ r1bio_pool_free(r1bio, data);
}
static void put_all_bios(conf_t *conf, r1bio_t *r1_bio)
@@ -510,7 +511,7 @@ static int make_request(request_queue_t *q, struct bio * bio)
mirror_info_t *mirror;
r1bio_t *r1_bio;
struct bio *read_bio;
- int i, disks = conf->raid_disks;
+ int i, disks;
/*
* Register the new request and wait if the reconstruction
@@ -570,6 +571,7 @@ static int make_request(request_queue_t *q, struct bio * bio)
* inc refcount on their rdev. Record them by setting
* bios[x] to bio
*/
+ disks = conf->raid_disks;
spin_lock_irq(&conf->device_lock);
for (i = 0; i < disks; i++) {
if (conf->mirrors[i].rdev &&
@@ -953,7 +955,8 @@ static int init_resync(conf_t *conf)
buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
if (conf->r1buf_pool)
BUG();
- conf->r1buf_pool = mempool_create(buffs, r1buf_pool_alloc, r1buf_pool_free, conf);
+ conf->r1buf_pool = mempool_create(buffs, r1buf_pool_alloc, r1buf_pool_free,
+ conf->poolinfo);
if (!conf->r1buf_pool)
return -ENOMEM;
conf->next_resync = 0;
@@ -1136,28 +1139,28 @@ static int run(mddev_t *mddev)
*/
conf = kmalloc(sizeof(conf_t), GFP_KERNEL);
mddev->private = conf;
- if (!conf) {
- printk(KERN_ERR "raid1: couldn't allocate memory for %s\n",
- mdname(mddev));
- goto out;
- }
+ if (!conf)
+ goto out_no_mem;
+
memset(conf, 0, sizeof(*conf));
conf->mirrors = kmalloc(sizeof(struct mirror_info)*mddev->raid_disks,
GFP_KERNEL);
- if (!conf->mirrors) {
- printk(KERN_ERR "raid1: couldn't allocate memory for %s\n",
- mdname(mddev));
- goto out_free_conf;
- }
+ if (!conf->mirrors)
+ goto out_no_mem;
+
memset(conf->mirrors, 0, sizeof(struct mirror_info)*mddev->raid_disks);
+ conf->poolinfo = kmalloc(sizeof(*conf->poolinfo), GFP_KERNEL);
+ if (!conf->poolinfo)
+ goto out_no_mem;
+ conf->poolinfo->mddev = mddev;
+ conf->poolinfo->raid_disks = mddev->raid_disks;
conf->r1bio_pool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
- r1bio_pool_free, mddev);
- if (!conf->r1bio_pool) {
- printk(KERN_ERR "raid1: couldn't allocate memory for %s\n",
- mdname(mddev));
- goto out_free_conf;
- }
+ r1bio_pool_free,
+ conf->poolinfo);
+ if (!conf->r1bio_pool)
+ goto out_no_mem;
+
mddev->queue->unplug_fn = raid1_unplug;
@@ -1243,13 +1246,21 @@ static int run(mddev_t *mddev)
return 0;
+out_no_mem:
+ printk(KERN_ERR "raid1: couldn't allocate memory for %s\n",
+ mdname(mddev));
+
out_free_conf:
- if (conf->r1bio_pool)
- mempool_destroy(conf->r1bio_pool);
- if (conf->mirrors)
- kfree(conf->mirrors);
- kfree(conf);
- mddev->private = NULL;
+ if (conf) {
+ if (conf->r1bio_pool)
+ mempool_destroy(conf->r1bio_pool);
+ if (conf->mirrors)
+ kfree(conf->mirrors);
+ if (conf->poolinfo)
+ kfree(conf->poolinfo);
+ kfree(conf);
+ mddev->private = NULL;
+ }
out:
return -EIO;
}
@@ -1264,6 +1275,8 @@ static int stop(mddev_t *mddev)
mempool_destroy(conf->r1bio_pool);
if (conf->mirrors)
kfree(conf->mirrors);
+ if (conf->poolinfo)
+ kfree(conf->poolinfo);
kfree(conf);
mddev->private = NULL;
return 0;
@@ -1289,6 +1302,81 @@ static int raid1_resize(mddev_t *mddev, sector_t sectors)
return 0;
}
+static int raid1_reshape(mddev_t *mddev, int raid_disks)
+{
+ /* We need to:
+ * 1/ resize the r1bio_pool
+ * 2/ resize conf->mirrors
+ *
+ * We allocate a new r1bio_pool if we can.
+ * Then raise a device barrier and wait until all IO stops.
+ * Then resize conf->mirrors and swap in the new r1bio pool.
+ */
+ mempool_t *newpool, *oldpool;
+ struct pool_info *newpoolinfo;
+ mirror_info_t *newmirrors;
+ conf_t *conf = mddev_to_conf(mddev);
+
+ int d;
+
+ for (d= raid_disks; d < conf->raid_disks; d++)
+ if (conf->mirrors[d].rdev)
+ return -EBUSY;
+
+ newpoolinfo = kmalloc(sizeof(newpoolinfo), GFP_KERNEL);
+ if (!newpoolinfo)
+ return -ENOMEM;
+ newpoolinfo->mddev = mddev;
+ newpoolinfo->raid_disks = raid_disks;
+
+ newpool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
+ r1bio_pool_free, newpoolinfo);
+ if (!newpool) {
+ kfree(newpoolinfo);
+ return -ENOMEM;
+ }
+ newmirrors = kmalloc(sizeof(struct mirror_info) * raid_disks, GFP_KERNEL);
+ if (!newmirrors) {
+ kfree(newpoolinfo);
+ mempool_destroy(newpool);
+ return -ENOMEM;
+ }
+ memset(newmirrors, 0, sizeof(struct mirror_info)*raid_disks);
+
+ spin_lock_irq(&conf->resync_lock);
+ conf->barrier++;
+ wait_event_lock_irq(conf->wait_idle, !conf->nr_pending,
+ conf->resync_lock, unplug_slaves(mddev));
+ spin_unlock_irq(&conf->resync_lock);
+
+ /* ok, everything is stopped */
+ oldpool = conf->r1bio_pool;
+ conf->r1bio_pool = newpool;
+ for (d=0; d < raid_disks && d < conf->raid_disks; d++)
+ newmirrors[d] = conf->mirrors[d];
+ kfree(conf->mirrors);
+ conf->mirrors = newmirrors;
+ kfree(conf->poolinfo);
+ conf->poolinfo = newpoolinfo;
+
+ mddev->degraded += (raid_disks - conf->raid_disks);
+ conf->raid_disks = mddev->raid_disks = raid_disks;
+
+ spin_lock_irq(&conf->resync_lock);
+ conf->barrier--;
+ spin_unlock_irq(&conf->resync_lock);
+ wake_up(&conf->wait_resume);
+ wake_up(&conf->wait_idle);
+
+
+ set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
+ md_wakeup_thread(mddev->thread);
+
+ mempool_destroy(oldpool);
+ return 0;
+}
+
+
static mdk_personality_t raid1_personality =
{
.name = "raid1",
@@ -1303,6 +1391,7 @@ static mdk_personality_t raid1_personality =
.spare_active = raid1_spare_active,
.sync_request = sync_request,
.resize = raid1_resize,
+ .reshape = raid1_reshape,
};
static int __init raid_init(void)
diff --git a/include/linux/raid/md_k.h b/include/linux/raid/md_k.h
index 1af736b37d0b..faa400cf25e4 100644
--- a/include/linux/raid/md_k.h
+++ b/include/linux/raid/md_k.h
@@ -280,6 +280,7 @@ struct mdk_personality_s
int (*spare_active) (mddev_t *mddev);
int (*sync_request)(mddev_t *mddev, sector_t sector_nr, int go_faster);
int (*resize) (mddev_t *mddev, sector_t sectors);
+ int (*reshape) (mddev_t *mddev, int raid_disks);
};
diff --git a/include/linux/raid/raid1.h b/include/linux/raid/raid1.h
index 96abcad3a307..50965d9680b6 100644
--- a/include/linux/raid/raid1.h
+++ b/include/linux/raid/raid1.h
@@ -10,6 +10,20 @@ struct mirror_info {
sector_t head_position;
};
+/*
+ * memory pools need a pointer to the mddev, so they can force an unplug
+ * when memory is tight, and a count of the number of drives that the
+ * pool was allocated for, so they know how much to allocate and free.
+ * mddev->raid_disks cannot be used, as it can change while a pool is active
+ * These two datums are stored in a kmalloced struct.
+ */
+
+struct pool_info {
+ mddev_t *mddev;
+ int raid_disks;
+};
+
+
typedef struct r1bio_s r1bio_t;
struct r1_private_data_s {
@@ -31,6 +45,8 @@ struct r1_private_data_s {
wait_queue_head_t wait_idle;
wait_queue_head_t wait_resume;
+ struct pool_info *poolinfo;
+
mempool_t *r1bio_pool;
mempool_t *r1buf_pool;
};