DM RAID: Record and handle missing devices
Missing dm-raid devices should be recorded in the superblock
When specifying the devices that compose a DM RAID array, it is possible to denote
failed or missing devices with '-'s. When this occurs, we must record this in the
superblock. We do this by checking if the array position's data device is missing
and then forcing MD to record the superblock by setting 'MD_CHANGE_DEVS' in
'raid_resume'. If we do not cause the superblock to be rewritten by the resume
function, it is possible for a stale superblock to be written by an out-going
in-active table (during 'raid_dtr').
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c
index ea2d90c..f1797c4 100644
--- a/drivers/md/dm-raid.c
+++ b/drivers/md/dm-raid.c
@@ -614,16 +614,18 @@
static void super_sync(struct mddev *mddev, struct md_rdev *rdev)
{
- struct md_rdev *r;
+ int i;
uint64_t failed_devices;
struct dm_raid_superblock *sb;
+ struct raid_set *rs = container_of(mddev, struct raid_set, md);
sb = page_address(rdev->sb_page);
failed_devices = le64_to_cpu(sb->failed_devices);
- rdev_for_each(r, mddev)
- if ((r->raid_disk >= 0) && test_bit(Faulty, &r->flags))
- failed_devices |= (1ULL << r->raid_disk);
+ for (i = 0; i < mddev->raid_disks; i++)
+ if (!rs->dev[i].data_dev ||
+ test_bit(Faulty, &(rs->dev[i].rdev.flags)))
+ failed_devices |= (1ULL << i);
memset(sb, 0, sizeof(*sb));
@@ -1249,6 +1251,7 @@
{
struct raid_set *rs = ti->private;
+ set_bit(MD_CHANGE_DEVS, &rs->md.flags);
if (!rs->bitmap_loaded) {
bitmap_load(&rs->md);
rs->bitmap_loaded = 1;