Merge tag 'dm-3.4-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm

Pull a dm fix from Alasdair G Kergon:
 "A fix to the thin provisioning userspace interface."

* tag 'dm-3.4-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm:
  dm thin: fix table output when pool target disables discard passdown internally

1 files changed, 17 insertions, 15 deletions

diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c
index 2fd87b544a93..eb3d138ff55a 100644
--- a/drivers/md/dm-thin.c
+++ b/drivers/md/dm-thin.c
@@ -1632,6 +1632,21 @@ static int bind_control_target(struct pool *pool, struct dm_target *ti)
         pool->low_water_blocks = pt->low_water_blocks;
         pool->pf = pt->pf;
 
+        /*
+         * If discard_passdown was enabled verify that the data device
+         * supports discards.  Disable discard_passdown if not; otherwise
+         * -EOPNOTSUPP will be returned.
+         */
+        if (pt->pf.discard_passdown) {
+                struct request_queue *q = bdev_get_queue(pt->data_dev->bdev);
+                if (!q || !blk_queue_discard(q)) {
+                        char buf[BDEVNAME_SIZE];
+                        DMWARN("Discard unsupported by data device (%s): Disabling discard passdown.",
+                               bdevname(pt->data_dev->bdev, buf));
+                        pool->pf.discard_passdown = 0;
+                }
+        }
+
         return 0;
 }
 
@@ -1988,19 +2003,6 @@ static int pool_ctr(struct dm_target *ti, unsigned argc, char **argv)
                 goto out_flags_changed;
         }
 
-        /*
-         * If discard_passdown was enabled verify that the data device
-         * supports discards.  Disable discard_passdown if not; otherwise
-         * -EOPNOTSUPP will be returned.
-         */
-        if (pf.discard_passdown) {
-                struct request_queue *q = bdev_get_queue(data_dev->bdev);
-                if (!q || !blk_queue_discard(q)) {
-                        DMWARN("Discard unsupported by data device: Disabling discard passdown.");
-                        pf.discard_passdown = 0;
-                }
-        }
-
         pt->pool = pool;
         pt->ti = ti;
         pt->metadata_dev = metadata_dev;
@@ -2385,7 +2387,7 @@ static int pool_status(struct dm_target *ti, status_type_t type,
                        (unsigned long long)pt->low_water_blocks);
 
                 count = !pool->pf.zero_new_blocks + !pool->pf.discard_enabled +
-                        !pool->pf.discard_passdown;
+                        !pt->pf.discard_passdown;
                 DMEMIT("%u ", count);
 
                 if (!pool->pf.zero_new_blocks)
@@ -2394,7 +2396,7 @@ static int pool_status(struct dm_target *ti, status_type_t type,
                 if (!pool->pf.discard_enabled)
                         DMEMIT("ignore_discard ");
 
-                if (!pool->pf.discard_passdown)
+                if (!pt->pf.discard_passdown)
                         DMEMIT("no_discard_passdown ");
 
                 break;