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authorGuoqing Jiang <gqjiang@suse.com>2017-03-01 16:42:40 +0800
committerShaohua Li <shli@fb.com>2017-03-16 16:55:50 -0700
commit818da59f97d6764edb91fa9d1f63d333d54eb999 (patch)
treec63c89cc1e0293d75685f3639c41a381acf7be13 /drivers/md/md-cluster.c
parentb98938d16a108d0201d54b8db1337dac71aebfdd (diff)
downloadlinux-818da59f97d6764edb91fa9d1f63d333d54eb999.tar.bz2
md-cluster: add the support for resize
To update size for cluster raid, we need to make sure all nodes can perform the change successfully. However, it is possible that some of them can't do it due to failure (bitmap_resize could fail). So we need to consider the issue before we set the capacity unconditionally, and we use below steps to perform sanity check. 1. A change the size, then broadcast METADATA_UPDATED msg. 2. B and C receive METADATA_UPDATED change the size excepts call set_capacity, sync_size is not update if the change failed. Also call bitmap_update_sb to sync sb to disk. 3. A checks other node's sync_size, if sync_size has been updated in all nodes, then send CHANGE_CAPACITY msg otherwise send msg to revert previous change. 4. B and C call set_capacity if receive CHANGE_CAPACITY msg, otherwise pers->resize will be called to restore the old value. Reviewed-by: NeilBrown <neilb@suse.com> Signed-off-by: Guoqing Jiang <gqjiang@suse.com> Signed-off-by: Shaohua Li <shli@fb.com>
Diffstat (limited to 'drivers/md/md-cluster.c')
-rw-r--r--drivers/md/md-cluster.c76
1 files changed, 76 insertions, 0 deletions
diff --git a/drivers/md/md-cluster.c b/drivers/md/md-cluster.c
index 92c3c51ede4d..b21ef58819f6 100644
--- a/drivers/md/md-cluster.c
+++ b/drivers/md/md-cluster.c
@@ -1151,6 +1151,81 @@ int cluster_check_sync_size(struct mddev *mddev)
return (my_sync_size == sync_size) ? 0 : -1;
}
+/*
+ * Update the size for cluster raid is a little more complex, we perform it
+ * by the steps:
+ * 1. hold token lock and update superblock in initiator node.
+ * 2. send METADATA_UPDATED msg to other nodes.
+ * 3. The initiator node continues to check each bitmap's sync_size, if all
+ * bitmaps have the same value of sync_size, then we can set capacity and
+ * let other nodes to perform it. If one node can't update sync_size
+ * accordingly, we need to revert to previous value.
+ */
+static void update_size(struct mddev *mddev, sector_t old_dev_sectors)
+{
+ struct md_cluster_info *cinfo = mddev->cluster_info;
+ struct cluster_msg cmsg;
+ struct md_rdev *rdev;
+ int ret = 0;
+ int raid_slot = -1;
+
+ md_update_sb(mddev, 1);
+ lock_comm(cinfo, 1);
+
+ memset(&cmsg, 0, sizeof(cmsg));
+ cmsg.type = cpu_to_le32(METADATA_UPDATED);
+ rdev_for_each(rdev, mddev)
+ if (rdev->raid_disk >= 0 && !test_bit(Faulty, &rdev->flags)) {
+ raid_slot = rdev->desc_nr;
+ break;
+ }
+ if (raid_slot >= 0) {
+ cmsg.raid_slot = cpu_to_le32(raid_slot);
+ /*
+ * We can only change capiticy after all the nodes can do it,
+ * so need to wait after other nodes already received the msg
+ * and handled the change
+ */
+ ret = __sendmsg(cinfo, &cmsg);
+ if (ret) {
+ pr_err("%s:%d: failed to send METADATA_UPDATED msg\n",
+ __func__, __LINE__);
+ unlock_comm(cinfo);
+ return;
+ }
+ } else {
+ pr_err("md-cluster: No good device id found to send\n");
+ unlock_comm(cinfo);
+ return;
+ }
+
+ /*
+ * check the sync_size from other node's bitmap, if sync_size
+ * have already updated in other nodes as expected, send an
+ * empty metadata msg to permit the change of capacity
+ */
+ if (cluster_check_sync_size(mddev) == 0) {
+ memset(&cmsg, 0, sizeof(cmsg));
+ cmsg.type = cpu_to_le32(CHANGE_CAPACITY);
+ ret = __sendmsg(cinfo, &cmsg);
+ if (ret)
+ pr_err("%s:%d: failed to send CHANGE_CAPACITY msg\n",
+ __func__, __LINE__);
+ set_capacity(mddev->gendisk, mddev->array_sectors);
+ revalidate_disk(mddev->gendisk);
+ } else {
+ /* revert to previous sectors */
+ ret = mddev->pers->resize(mddev, old_dev_sectors);
+ if (!ret)
+ revalidate_disk(mddev->gendisk);
+ ret = __sendmsg(cinfo, &cmsg);
+ if (ret)
+ pr_err("%s:%d: failed to send METADATA_UPDATED msg\n",
+ __func__, __LINE__);
+ }
+ unlock_comm(cinfo);
+}
+
static int resync_start(struct mddev *mddev)
{
struct md_cluster_info *cinfo = mddev->cluster_info;
@@ -1396,6 +1471,7 @@ static struct md_cluster_operations cluster_ops = {
.gather_bitmaps = gather_bitmaps,
.lock_all_bitmaps = lock_all_bitmaps,
.unlock_all_bitmaps = unlock_all_bitmaps,
+ .update_size = update_size,
};
static int __init cluster_init(void)