Commit 15858fa5 authored by Guoqing Jiang's avatar Guoqing Jiang Committed by NeilBrown
Browse files

md-cluster: Defer MD reloading to mddev->thread 



Reloading of superblock must be performed under reconfig_mutex. However,
this cannot be done with md_reload_sb because it would deadlock with
the message DLM lock. So, we defer it in md_check_recovery() which is
executed by mddev->thread.

This introduces a new flag, MD_RELOAD_SB, which if set, will reload the
superblock. And good_device_nr is also added to 'struct mddev' which is
used to get the num of the good device within cluster raid.

Signed-off-by: default avatarGoldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: default avatarGuoqing Jiang <gqjiang@suse.com>
Signed-off-by: default avatarNeilBrown <neilb@suse.com>
parent d323ef0f

drivers/md/md-cluster.c

+3 −1
Original line number Diff line number Diff line
@@ -432,8 +432,10 @@ static void process_add_new_disk(struct mddev *mddev, struct cluster_msg *cmsg) 
static void process_metadata_update(struct mddev *mddev, struct cluster_msg *msg)

{

	struct md_cluster_info *cinfo = mddev->cluster_info;

	md_reload_sb(mddev, le32_to_cpu(msg->raid_slot));

	mddev->good_device_nr = le32_to_cpu(msg->raid_slot);

	set_bit(MD_RELOAD_SB, &mddev->flags);

	dlm_lock_sync(cinfo->no_new_dev_lockres, DLM_LOCK_CR);

	md_wakeup_thread(mddev->thread);

}



static void process_remove_disk(struct mddev *mddev, struct cluster_msg *msg)

drivers/md/md.c

+4 −0
Original line number Diff line number Diff line
@@ -8286,6 +8286,7 @@ void md_check_recovery(struct mddev *mddev) 
		(mddev->flags & MD_UPDATE_SB_FLAGS & ~ (1<<MD_CHANGE_PENDING)) ||

		test_bit(MD_RECOVERY_NEEDED, &mddev->recovery) ||

		test_bit(MD_RECOVERY_DONE, &mddev->recovery) ||

		test_bit(MD_RELOAD_SB, &mddev->flags) ||

		(mddev->external == 0 && mddev->safemode == 1) ||

		(mddev->safemode == 2 && ! atomic_read(&mddev->writes_pending)

		 && !mddev->in_sync && mddev->recovery_cp == MaxSector)
@@ -8334,6 +8335,9 @@ void md_check_recovery(struct mddev *mddev) 
						rdev->raid_disk < 0)

					md_kick_rdev_from_array(rdev);

			}



			if (test_and_clear_bit(MD_RELOAD_SB, &mddev->flags))

				md_reload_sb(mddev, mddev->good_device_nr);

		}



		if (!mddev->external) {

drivers/md/md.h

+4 −0
Original line number Diff line number Diff line
@@ -235,6 +235,9 @@ struct mddev { 
				 */

#define MD_JOURNAL_CLEAN 5	/* A raid with journal is already clean */

#define MD_HAS_JOURNAL	6	/* The raid array has journal feature set */

#define MD_RELOAD_SB	7	/* Reload the superblock because another node

				 * updated it.

				 */



	int				suspended;

	atomic_t			active_io;
@@ -465,6 +468,7 @@ struct mddev { 
	struct work_struct event_work;	/* used by dm to report failure event */

	void (*sync_super)(struct mddev *mddev, struct md_rdev *rdev);

	struct md_cluster_info		*cluster_info;

	unsigned int			good_device_nr;	/* good device num within cluster raid */

};



static inline int __must_check mddev_lock(struct mddev *mddev)

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