From 3ace8d52ee4afac46e4d718612efa09591bd7506 Mon Sep 17 00:00:00 2001 From: Zhao Heming Date: Thu, 19 Nov 2020 19:41:33 +0800 Subject: [PATCH] md/cluster: block reshape with remote resync job commit a8da01f79c89755fad55ed0ea96e8d2103242a72 upstream. Reshape request should be blocked with ongoing resync job. In cluster env, a node can start resync job even if the resync cmd isn't executed on it, e.g., user executes "mdadm --grow" on node A, sometimes node B will start resync job. However, current update_raid_disks() only check local recovery status, which is incomplete. As a result, we see user will execute "mdadm --grow" successfully on local, while the remote node deny to do reshape job when it doing resync job. The inconsistent handling cause array enter unexpected status. If user doesn't observe this issue and continue executing mdadm cmd, the array doesn't work at last. Fix this issue by blocking reshape request. When node executes "--grow" and detects ongoing resync, it should stop and report error to user. The following script reproduces the issue with ~100% probability. (two nodes share 3 iSCSI luns: sdg/sdh/sdi. Each lun size is 1GB) ``` # on node1, node2 is the remote node. ssh root@node2 "mdadm -S --scan" mdadm -S --scan for i in {g,h,i};do dd if=/dev/zero of=/dev/sd$i oflag=direct bs=1M \ count=20; done mdadm -C /dev/md0 -b clustered -e 1.2 -n 2 -l mirror /dev/sdg /dev/sdh ssh root@node2 "mdadm -A /dev/md0 /dev/sdg /dev/sdh" sleep 5 mdadm --manage --add /dev/md0 /dev/sdi mdadm --wait /dev/md0 mdadm --grow --raid-devices=3 /dev/md0 mdadm /dev/md0 --fail /dev/sdg mdadm /dev/md0 --remove /dev/sdg mdadm --grow --raid-devices=2 /dev/md0 ``` Cc: stable@vger.kernel.org Signed-off-by: Zhao Heming Signed-off-by: Song Liu Signed-off-by: Greg Kroah-Hartman --- drivers/md/md.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index 4136bd8142894..55f9ddf6f44f4 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -7278,6 +7278,7 @@ static int update_raid_disks(struct mddev *mddev, int raid_disks) return -EINVAL; if (mddev->sync_thread || test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) || + test_bit(MD_RESYNCING_REMOTE, &mddev->recovery) || mddev->reshape_position != MaxSector) return -EBUSY; @@ -9645,8 +9646,11 @@ static void check_sb_changes(struct mddev *mddev, struct md_rdev *rdev) } } - if (mddev->raid_disks != le32_to_cpu(sb->raid_disks)) - update_raid_disks(mddev, le32_to_cpu(sb->raid_disks)); + if (mddev->raid_disks != le32_to_cpu(sb->raid_disks)) { + ret = update_raid_disks(mddev, le32_to_cpu(sb->raid_disks)); + if (ret) + pr_warn("md: updating array disks failed. %d\n", ret); + } /* * Since mddev->delta_disks has already updated in update_raid_disks,