md-cluster: Fix adding of new disk with new reload code
Adding the disk worked incorrectly with the new reload code. Fix it:
- No operation should be performed on rdev marked as Candidate
- After a metadata update operation, kick disk if role is 0xfffe
else clear Candidate bit and continue with the regular change check.
- Saving the mode of the lock resource to check if token lock is already
locked, because it can be called twice while adding a disk. However,
unlock_comm() must be called only once.
- add_new_disk() is called by the node initiating the --add operation.
If it needs to be canceled, call add_new_disk_cancel(). The operation
is completed by md_update_sb() which will write and unlock the
communication.
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
diff --git a/drivers/md/md-cluster.c b/drivers/md/md-cluster.c
index e1ce9c9..28494e9 100644
--- a/drivers/md/md-cluster.c
+++ b/drivers/md/md-cluster.c
@@ -28,6 +28,7 @@
struct completion completion; /* completion for synchronized locking */
void (*bast)(void *arg, int mode); /* blocking AST function pointer*/
struct mddev *mddev; /* pointing back to mddev. */
+ int mode;
};
struct suspend_info {
@@ -107,6 +108,8 @@
if (ret)
return ret;
wait_for_completion(&res->completion);
+ if (res->lksb.sb_status == 0)
+ res->mode = mode;
return res->lksb.sb_status;
}
@@ -128,6 +131,7 @@
init_completion(&res->completion);
res->ls = cinfo->lockspace;
res->mddev = mddev;
+ res->mode = DLM_LOCK_IV;
namelen = strlen(name);
res->name = kzalloc(namelen + 1, GFP_KERNEL);
if (!res->name) {
@@ -536,11 +540,17 @@
/* lock_comm()
* Takes the lock on the TOKEN lock resource so no other
* node can communicate while the operation is underway.
+ * If called again, and the TOKEN lock is alread in EX mode
+ * return success. However, care must be taken that unlock_comm()
+ * is called only once.
*/
static int lock_comm(struct md_cluster_info *cinfo)
{
int error;
+ if (cinfo->token_lockres->mode == DLM_LOCK_EX)
+ return 0;
+
error = dlm_lock_sync(cinfo->token_lockres, DLM_LOCK_EX);
if (error)
pr_err("md-cluster(%s:%d): failed to get EX on TOKEN (%d)\n",
@@ -550,6 +560,7 @@
static void unlock_comm(struct md_cluster_info *cinfo)
{
+ WARN_ON(cinfo->token_lockres->mode != DLM_LOCK_EX);
dlm_unlock_sync(cinfo->token_lockres);
}
@@ -862,11 +873,10 @@
return ret;
}
-static int metadata_update_cancel(struct mddev *mddev)
+static void metadata_update_cancel(struct mddev *mddev)
{
struct md_cluster_info *cinfo = mddev->cluster_info;
-
- return dlm_unlock_sync(cinfo->token_lockres);
+ unlock_comm(cinfo);
}
static int resync_start(struct mddev *mddev)
@@ -925,7 +935,11 @@
return ret;
}
-static int add_new_disk_start(struct mddev *mddev, struct md_rdev *rdev)
+/* add_new_disk() - initiates a disk add
+ * However, if this fails before writing md_update_sb(),
+ * add_new_disk_cancel() must be called to release token lock
+ */
+static int add_new_disk(struct mddev *mddev, struct md_rdev *rdev)
{
struct md_cluster_info *cinfo = mddev->cluster_info;
struct cluster_msg cmsg;
@@ -947,16 +961,17 @@
/* Some node does not "see" the device */
if (ret == -EAGAIN)
ret = -ENOENT;
+ if (ret)
+ unlock_comm(cinfo);
else
dlm_lock_sync(cinfo->no_new_dev_lockres, DLM_LOCK_CR);
return ret;
}
-static int add_new_disk_finish(struct mddev *mddev)
+static void add_new_disk_cancel(struct mddev *mddev)
{
- /* Write sb and inform others */
- md_update_sb(mddev, 1);
- return metadata_update_finish(mddev);
+ struct md_cluster_info *cinfo = mddev->cluster_info;
+ unlock_comm(cinfo);
}
static int new_disk_ack(struct mddev *mddev, bool ack)
@@ -1023,8 +1038,8 @@
.metadata_update_finish = metadata_update_finish,
.metadata_update_cancel = metadata_update_cancel,
.area_resyncing = area_resyncing,
- .add_new_disk_start = add_new_disk_start,
- .add_new_disk_finish = add_new_disk_finish,
+ .add_new_disk = add_new_disk,
+ .add_new_disk_cancel = add_new_disk_cancel,
.new_disk_ack = new_disk_ack,
.remove_disk = remove_disk,
.gather_bitmaps = gather_bitmaps,