The following test fails when the md_check_recovery() event triggered by the ro->rw transition causes remove_and_add_spares() to run while mdmon is attempting spare activation. Result is that the kernel races to set the slot immediately after sysfs_add_disk() writes new_dev. mdmon thinks the spare activation failed and declines to send the monitor a new acitve_array. We show degraded after the wait because the monitor cannot notify the metadata that all disks are in_sync. #!/bin/bash i=0 false while [ $? == 1 ] do i=$((i+1)) mdadm -Ss mdadm -CR /dev/md0 /dev/loop[0-2] -n 3 -e imsm mdadm -CR /dev/md1 /dev/loop[01] missing -n 3 -l 5 mdadm --wait /dev/md1 mdadm -E /dev/loop2 | grep -i degraded done echo "failed: $i" Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx> --- managemon.c | 5 ++++- 1 files changed, 4 insertions(+), 1 deletions(-) diff --git a/managemon.c b/managemon.c index 6662f67..d020f82 100644 --- a/managemon.c +++ b/managemon.c @@ -498,7 +498,10 @@ static void manage_member(struct mdstat_ent *mdstat, newa = duplicate_aa(a); if (!newa) goto out; - /* Cool, we can add a device or several. */ + /* prevent the kernel from activating the disk(s) before we + * finish adding them + */ + sysfs_set_str(&a->info, NULL, "sync_action", "frozen"); /* Add device to array and set offset/size/slot. * and open files for each newdev */ -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
