From: Mike Snitzer <snitzer@redhat.com>
Date: Thu, 12 Aug 2010 03:14:12 +0000 (+0100)
Subject: dm: zero silently drop discards
X-Git-Tag: v2.6.36-rc1~51^2~7
X-Git-Url: http://bbs.cooldavid.org/git/?a=commitdiff_plain;h=f8facb61b5095488a4d78fa78116ef4f4b82bc4d;p=net-next-2.6.git

dm: zero silently drop discards

Have the zero target silently drop a discard rather than fail the
request with -EOPNOTSUPP.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
---

diff --git a/drivers/md/dm-zero.c b/drivers/md/dm-zero.c
index bbc97030c0c..cc2b3cb8194 100644
--- a/drivers/md/dm-zero.c
+++ b/drivers/md/dm-zero.c
@@ -22,6 +22,11 @@ static int zero_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 		return -EINVAL;
 	}
 
+	/*
+	 * Silently drop discards, avoiding -EOPNOTSUPP.
+	 */
+	ti->num_discard_requests = 1;
+
 	return 0;
 }