From: Mike Snitzer Implement the .iterate_devices for the origin and snapshot targets. dm-snapshot's lack of .iterate_devices resulted in the inability to properly establish queue_limits for both targets. With 4K sector drives: an unfortunate side-effect of not establishing proper limits in either targets' DM device was that IO to the devices would fail even though both had been created without error. Commit af4874e03ed82f050d5872d8c39ce64bf16b5c38 ("dm target:s introduce iterate devices fn") in 2.6.31-rc1 should have implemented .iterate_devices for dm-snap.c's origin and snapshot targets. Signed-off-by: Mike Snitzer Signed-off-by: Andrew Morton Signed-off-by: Alasdair G Kergon --- drivers/md/dm-snap.c | 23 +++++++++++++++++++++-- 1 file changed, 21 insertions(+), 2 deletions(-) Index: linux-2.6.31-rc8/drivers/md/dm-snap.c =================================================================== --- linux-2.6.31-rc8.orig/drivers/md/dm-snap.c +++ linux-2.6.31-rc8/drivers/md/dm-snap.c @@ -1176,6 +1176,15 @@ static int snapshot_status(struct dm_tar return 0; } +static int snapshot_iterate_devices(struct dm_target *ti, + iterate_devices_callout_fn fn, void *data) +{ + struct dm_snapshot *snap = ti->private; + + return fn(ti, snap->origin, 0, ti->len, data); +} + + /*----------------------------------------------------------------- * Origin methods *---------------------------------------------------------------*/ @@ -1410,20 +1419,29 @@ static int origin_status(struct dm_targe return 0; } +static int origin_iterate_devices(struct dm_target *ti, + iterate_devices_callout_fn fn, void *data) +{ + struct dm_dev *dev = ti->private; + + return fn(ti, dev, 0, ti->len, data); +} + static struct target_type origin_target = { .name = "snapshot-origin", - .version = {1, 6, 0}, + .version = {1, 7, 0}, .module = THIS_MODULE, .ctr = origin_ctr, .dtr = origin_dtr, .map = origin_map, .resume = origin_resume, .status = origin_status, + .iterate_devices = origin_iterate_devices, }; static struct target_type snapshot_target = { .name = "snapshot", - .version = {1, 6, 0}, + .version = {1, 7, 0}, .module = THIS_MODULE, .ctr = snapshot_ctr, .dtr = snapshot_dtr, @@ -1431,6 +1449,7 @@ static struct target_type snapshot_targe .end_io = snapshot_end_io, .resume = snapshot_resume, .status = snapshot_status, + .iterate_devices = snapshot_iterate_devices, }; static int __init dm_snapshot_init(void)