From 77b72fa828132a35c8b2e08d3fb07eea80b11895 Mon Sep 17 00:00:00 2001 From: allenpeng Date: Fri, 12 Jun 2020 17:00:39 +0800 Subject: [PATCH 086/108] mdadm/Grow: prevent md's fd from being occupied during delayed time If we start reshaping on md which shares sub-devices with another resyncing md, it may be forced to wait for others to complete. mdadm occupies the md's fd during this time, which causes the md can not be stopped and the filesystem can not be mounted on the md. We can close md's fd earlier to solve this problem. Reproducible Steps: 1. create two partitions on sda, sdb, sdc, sdd 2. create raid1 with sda1, sdb1 mdadm -C /dev/md1 --assume-clean -l1 -n2 /dev/sda1 /dev/sdb1 3. create raid5 with sda2, sdb2, sdc2 mdadm -C /dev/md2 --assume-clean -l5 -n3 /dev/sda2 /dev/sdb2 /dev/sdc2 4. start resync at md1 echo repair > /sys/block/md1/md/sync_action 5. reshape raid5 to raid6 mdadm -a /dev/md2 /dev/sdd2 mdadm --grow /dev/md2 -n4 -l6 --backup-file=/root/md2-backup Now mdadm is occupying the fd of md2, causing md2 unable to be stopped 6.Try to stop md2, an error message shows mdadm -S /dev/md2 mdadm: Cannot get exclusive access to /dev/md3:Perhaps a running process, mounted filesystem or active volume group? Reviewed-by: Alex Wu Reviewed-by: BingJing Chang Reviewed-by: Danny Shih Signed-off-by: ChangSyun Peng Signed-off-by: Jes Sorensen --- Grow.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/Grow.c b/Grow.c index 764374f..57db7d4 100644 --- a/Grow.c +++ b/Grow.c @@ -3517,6 +3517,7 @@ started: return 0; } + close(fd); /* Now we just need to kick off the reshape and watch, while * handling backups of the data... * This is all done by a forked background process. @@ -3569,7 +3570,6 @@ started: mdstat_wait(30 - (delayed-1) * 25); } while (delayed); mdstat_close(); - close(fd); if (check_env("MDADM_GROW_VERIFY")) fd = open(devname, O_RDONLY | O_DIRECT); else -- 2.7.5