From 936688d7eb0f39be96c5791be1a04994cc8d6aa0 Mon Sep 17 00:00:00 2001 From: Mike Snitzer <snitzer@redhat.com> Date: Tue, 2 Aug 2011 12:32:01 +0100 Subject: dm table: fix discard support Remove 'discards_supported' from the dm_table structure. The same information can be easily discovered from the table's target(s) in dm_table_supports_discards(). Before this fix dm_table_supports_discards() would skip checking the individual targets' 'discards_supported' flag if any one target in the table didn't set num_discard_requests > 0. Now the per-target 'discards_supported' flag is effective at insuring the final DM device advertises discard support. But, to be clear, targets that don't support discards (!num_discard_requests) will not receive discard requests. Also DMWARN if a target sets 'discards_supported' override but forgets to set 'num_discard_requests'. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> --- drivers/md/dm.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'drivers/md/dm.c') diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 41abc6dd481b..aeb0fa1ccfe4 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1179,7 +1179,8 @@ static int __clone_and_map_discard(struct clone_info *ci) /* * Even though the device advertised discard support, - * reconfiguration might have changed that since the + * that does not mean every target supports it, and + * reconfiguration might also have changed that since the * check was performed. */ if (!ti->num_discard_requests) -- cgit v1.2.2