From 28c1b9fdf4562b52fe104384b16238c39c8a8d40 Mon Sep 17 00:00:00 2001 From: Goldwyn Rodrigues Date: Thu, 22 Oct 2015 16:01:25 +1100 Subject: [PATCH] md-cluster: Call update_raid_disks() if another node --grow's raid_disks To incorporate --grow feature executed on one node, other nodes need to acknowledge the change in number of disks. Call update_raid_disks() to update internal data structures. This leads to call check_reshape() -> md_allow_write() -> md_update_sb(), this results in a deadlock. This is done so it can safely allocate memory (which might trigger writeback which might write to raid1). This is not required for md with a bitmap. In the clustered case, we don't perform md_update_sb() in md_allow_write(), but in do_md_run(). Also we disable safemode for clustered mode. mddev->recovery_cp need not be set in check_sb_changes() because this is required only when a node reads another node's bitmap. mddev->recovery_cp (which is read from sb->resync_offset), is set only if mddev is in_sync. Since we disabled safemode, in_sync is set to zero. In a clustered environment, the MD may not be in sync because another node could be writing to it. So make sure that in_sync is not set in case of clustered node in __md_stop_writes(). Signed-off-by: Goldwyn Rodrigues Signed-off-by: NeilBrown --- drivers/md/md.c | 25 ++++++++++++++++++------- drivers/md/raid1.c | 8 +++++--- 2 files changed, 23 insertions(+), 10 deletions(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index a71b36f0acb0..44d034246723 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -2230,7 +2230,6 @@ static bool does_sb_need_changing(struct mddev *mddev) /* Check if any mddev parameters have changed */ if ((mddev->dev_sectors != le64_to_cpu(sb->size)) || (mddev->reshape_position != le64_to_cpu(sb->reshape_position)) || - (mddev->recovery_cp != le64_to_cpu(sb->resync_offset)) || (mddev->layout != le64_to_cpu(sb->layout)) || (mddev->raid_disks != le32_to_cpu(sb->raid_disks)) || (mddev->chunk_sectors != le32_to_cpu(sb->chunksize))) @@ -3314,6 +3313,11 @@ safe_delay_store(struct mddev *mddev, const char *cbuf, size_t len) { unsigned long msec; + if (mddev_is_clustered(mddev)) { + pr_info("md: Safemode is disabled for clustered mode\n"); + return -EINVAL; + } + if (strict_strtoul_scaled(cbuf, &msec, 3) < 0) return -EINVAL; if (msec == 0) @@ -5224,7 +5228,10 @@ int md_run(struct mddev *mddev) atomic_set(&mddev->max_corr_read_errors, MD_DEFAULT_MAX_CORRECTED_READ_ERRORS); mddev->safemode = 0; - mddev->safemode_delay = (200 * HZ)/1000 +1; /* 200 msec delay */ + if (mddev_is_clustered(mddev)) + mddev->safemode_delay = 0; + else + mddev->safemode_delay = (200 * HZ)/1000 +1; /* 200 msec delay */ mddev->in_sync = 1; smp_wmb(); spin_lock(&mddev->lock); @@ -5267,6 +5274,9 @@ static int do_md_run(struct mddev *mddev) goto out; } + if (mddev_is_clustered(mddev)) + md_allow_write(mddev); + md_wakeup_thread(mddev->thread); md_wakeup_thread(mddev->sync_thread); /* possibly kick off a reshape */ @@ -5363,9 +5373,11 @@ static void __md_stop_writes(struct mddev *mddev) md_super_wait(mddev); if (mddev->ro == 0 && - (!mddev->in_sync || (mddev->flags & MD_UPDATE_SB_FLAGS))) { + ((!mddev->in_sync && !mddev_is_clustered(mddev)) || + (mddev->flags & MD_UPDATE_SB_FLAGS))) { /* mark array as shutdown cleanly */ - mddev->in_sync = 1; + if (!mddev_is_clustered(mddev)) + mddev->in_sync = 1; md_update_sb(mddev, 1); } } @@ -9007,9 +9019,8 @@ static void check_sb_changes(struct mddev *mddev, struct md_rdev *rdev) } } - /* recovery_cp changed */ - if (le64_to_cpu(sb->resync_offset) != mddev->recovery_cp) - mddev->recovery_cp = le64_to_cpu(sb->resync_offset); + if (mddev->raid_disks != le32_to_cpu(sb->raid_disks)) + update_raid_disks(mddev, le32_to_cpu(sb->raid_disks)); /* Finally set the event to be up to date */ mddev->events = le64_to_cpu(sb->events); diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index ce2d797f8787..c1ad0b075807 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -3044,9 +3044,11 @@ static int raid1_reshape(struct mddev *mddev) return -EINVAL; } - err = md_allow_write(mddev); - if (err) - return err; + if (!mddev_is_clustered(mddev)) { + err = md_allow_write(mddev); + if (err) + return err; + } raid_disks = mddev->raid_disks + mddev->delta_disks; -- 2.34.1