From c186b128cda5a246da25f474e4689cb2bfacfcac Mon Sep 17 00:00:00 2001 From: Goldwyn Rodrigues Date: Wed, 30 Sep 2015 13:20:35 -0500 Subject: [PATCH] md-cluster: Perform resync/recovery under a DLM lock Resync or recovery must be performed by only one node at a time. A DLM lock resource, resync_lockres provides the mutual exclusion so that only one node performs the recovery/resync at a time. If a node is unable to get the resync_lockres, because recovery is being performed by another node, it set MD_RECOVER_NEEDED so as to schedule recovery in the future. Remove the debug message in resync_info_update() used during development. Signed-off-by: Goldwyn Rodrigues --- drivers/md/md-cluster.c | 29 ++++++++++++++++++++++++++--- drivers/md/md-cluster.h | 2 ++ drivers/md/md.c | 29 +++++++++++++++++++++++++---- drivers/md/raid1.c | 2 -- 4 files changed, 53 insertions(+), 9 deletions(-) diff --git a/drivers/md/md-cluster.c b/drivers/md/md-cluster.c index 2eb3a50..e1ce9c9 100644 --- a/drivers/md/md-cluster.c +++ b/drivers/md/md-cluster.c @@ -55,6 +55,7 @@ struct md_cluster_info { struct completion completion; struct mutex sb_mutex; struct dlm_lock_resource *bitmap_lockres; + struct dlm_lock_resource *resync_lockres; struct list_head suspend_list; spinlock_t suspend_lock; struct md_thread *recovery_thread; @@ -384,6 +385,8 @@ static void process_suspend_info(struct mddev *mddev, if (!hi) { remove_suspend_info(mddev, slot); + set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); + md_wakeup_thread(mddev->thread); return; } s = kzalloc(sizeof(struct suspend_info), GFP_KERNEL); @@ -758,6 +761,10 @@ static int join(struct mddev *mddev, int nodes) goto err; } + cinfo->resync_lockres = lockres_init(mddev, "resync", NULL, 0); + if (!cinfo->resync_lockres) + goto err; + ret = gather_all_resync_info(mddev, nodes); if (ret) goto err; @@ -768,6 +775,7 @@ err: lockres_free(cinfo->token_lockres); lockres_free(cinfo->ack_lockres); lockres_free(cinfo->no_new_dev_lockres); + lockres_free(cinfo->resync_lockres); lockres_free(cinfo->bitmap_lockres); if (cinfo->lockspace) dlm_release_lockspace(cinfo->lockspace, 2); @@ -861,6 +869,13 @@ static int metadata_update_cancel(struct mddev *mddev) return dlm_unlock_sync(cinfo->token_lockres); } +static int resync_start(struct mddev *mddev) +{ + struct md_cluster_info *cinfo = mddev->cluster_info; + cinfo->resync_lockres->flags |= DLM_LKF_NOQUEUE; + return dlm_lock_sync(cinfo->resync_lockres, DLM_LOCK_EX); +} + static int resync_info_update(struct mddev *mddev, sector_t lo, sector_t hi) { struct md_cluster_info *cinfo = mddev->cluster_info; @@ -870,16 +885,22 @@ static int resync_info_update(struct mddev *mddev, sector_t lo, sector_t hi) add_resync_info(mddev, cinfo->bitmap_lockres, lo, hi); /* Re-acquire the lock to refresh LVB */ dlm_lock_sync(cinfo->bitmap_lockres, DLM_LOCK_PW); - pr_info("%s:%d lo: %llu hi: %llu\n", __func__, __LINE__, - (unsigned long long)lo, - (unsigned long long)hi); cmsg.type = cpu_to_le32(RESYNCING); cmsg.slot = cpu_to_le32(slot); cmsg.low = cpu_to_le64(lo); cmsg.high = cpu_to_le64(hi); + return sendmsg(cinfo, &cmsg); } +static int resync_finish(struct mddev *mddev) +{ + struct md_cluster_info *cinfo = mddev->cluster_info; + cinfo->resync_lockres->flags &= ~DLM_LKF_NOQUEUE; + dlm_unlock_sync(cinfo->resync_lockres); + return resync_info_update(mddev, 0, 0); +} + static int area_resyncing(struct mddev *mddev, int direction, sector_t lo, sector_t hi) { @@ -995,6 +1016,8 @@ static struct md_cluster_operations cluster_ops = { .join = join, .leave = leave, .slot_number = slot_number, + .resync_start = resync_start, + .resync_finish = resync_finish, .resync_info_update = resync_info_update, .metadata_update_start = metadata_update_start, .metadata_update_finish = metadata_update_finish, diff --git a/drivers/md/md-cluster.h b/drivers/md/md-cluster.h index f5bdc0c..c941726 100644 --- a/drivers/md/md-cluster.h +++ b/drivers/md/md-cluster.h @@ -16,6 +16,8 @@ struct md_cluster_operations { int (*metadata_update_start)(struct mddev *mddev); int (*metadata_update_finish)(struct mddev *mddev); int (*metadata_update_cancel)(struct mddev *mddev); + int (*resync_start)(struct mddev *mddev); + int (*resync_finish)(struct mddev *mddev); int (*area_resyncing)(struct mddev *mddev, int direction, sector_t lo, sector_t hi); int (*add_new_disk_start)(struct mddev *mddev, struct md_rdev *rdev); int (*add_new_disk_finish)(struct mddev *mddev); diff --git a/drivers/md/md.c b/drivers/md/md.c index 5f09678..61e897de 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -7657,6 +7657,7 @@ void md_do_sync(struct md_thread *thread) struct md_rdev *rdev; char *desc, *action = NULL; struct blk_plug plug; + bool cluster_resync_finished = false; /* just incase thread restarts... */ if (test_bit(MD_RECOVERY_DONE, &mddev->recovery)) @@ -7959,7 +7960,11 @@ void md_do_sync(struct md_thread *thread) mddev->curr_resync_completed = mddev->curr_resync; sysfs_notify(&mddev->kobj, NULL, "sync_completed"); } - /* tell personality that we are finished */ + /* tell personality and other nodes that we are finished */ + if (mddev_is_clustered(mddev)) { + md_cluster_ops->resync_finish(mddev); + cluster_resync_finished = true; + } mddev->pers->sync_request(mddev, max_sectors, &skipped); if (!test_bit(MD_RECOVERY_CHECK, &mddev->recovery) && @@ -7997,6 +8002,11 @@ void md_do_sync(struct md_thread *thread) skip: set_bit(MD_CHANGE_DEVS, &mddev->flags); + if (mddev_is_clustered(mddev) && + test_bit(MD_RECOVERY_INTR, &mddev->recovery) && + !cluster_resync_finished) + md_cluster_ops->resync_finish(mddev); + spin_lock(&mddev->lock); if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery)) { /* We completed so min/max setting can be forgotten if used. */ @@ -8078,14 +8088,25 @@ no_add: static void md_start_sync(struct work_struct *ws) { struct mddev *mddev = container_of(ws, struct mddev, del_work); + int ret = 0; + + if (mddev_is_clustered(mddev)) { + ret = md_cluster_ops->resync_start(mddev); + if (ret) { + mddev->sync_thread = NULL; + goto out; + } + } mddev->sync_thread = md_register_thread(md_do_sync, mddev, "resync"); +out: if (!mddev->sync_thread) { - printk(KERN_ERR "%s: could not start resync" - " thread...\n", - mdname(mddev)); + if (!(mddev_is_clustered(mddev) && ret == -EAGAIN)) + printk(KERN_ERR "%s: could not start resync" + " thread...\n", + mdname(mddev)); /* leave the spares where they are, it shouldn't hurt */ clear_bit(MD_RECOVERY_SYNC, &mddev->recovery); clear_bit(MD_RECOVERY_RESHAPE, &mddev->recovery); diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index b54fefc..a2d813c 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -2503,8 +2503,6 @@ static sector_t sync_request(struct mddev *mddev, sector_t sector_nr, int *skipp if (mddev_is_clustered(mddev)) { conf->cluster_sync_low = 0; conf->cluster_sync_high = 0; - /* Send zeros to mark end of resync */ - md_cluster_ops->resync_info_update(mddev, 0, 0); } return 0; } -- 2.7.4