dm thin: disable discards for thin-pool if no_discard_passdown

Also rename disable_passdown_if_not_supported to
disable_discard_passdown_if_not_supported.

And fold passdown_enabled() into only caller.

Signed-off-by: Mike Snitzer <snitzer@kernel.org>

diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c
index ebcfd84..5b0c2f0 100644 (file)
--- a/drivers/md/dm-thin.c
+++ b/drivers/md/dm-thin.c
@@ -2528,16 +2528,11 @@ static void noflush_work(struct thin_c *tc, void (*fn)(struct work_struct *))
 
 /*----------------------------------------------------------------*/
 
-static bool passdown_enabled(struct pool_c *pt)
-{
-       return pt->adjusted_pf.discard_passdown;
-}
-
 static void set_discard_callbacks(struct pool *pool)
 {
        struct pool_c *pt = pool->ti->private;
 
-       if (passdown_enabled(pt)) {
+       if (pt->adjusted_pf.discard_passdown) {
                pool->process_discard_cell = process_discard_cell_passdown;
                pool->process_prepared_discard = process_prepared_discard_passdown_pt1;
                pool->process_prepared_discard_pt2 = process_prepared_discard_passdown_pt2;
@@ -2846,7 +2841,7 @@ static bool is_factor(sector_t block_size, uint32_t n)
  * If discard_passdown was enabled verify that the data device
  * supports discards.  Disable discard_passdown if not.
  */
-static void disable_passdown_if_not_supported(struct pool_c *pt)
+static void disable_discard_passdown_if_not_supported(struct pool_c *pt)
 {
        struct pool *pool = pt->pool;
        struct block_device *data_bdev = pt->data_dev->bdev;
@@ -4100,7 +4095,9 @@ static void pool_io_hints(struct dm_target *ti, struct queue_limits *limits)
         */
 
        if (pt->adjusted_pf.discard_enabled) {
-               disable_passdown_if_not_supported(pt);
+               disable_discard_passdown_if_not_supported(pt);
+               if (!pt->adjusted_pf.discard_passdown)
+                       limits->max_discard_sectors = 0;
                /*
                 * The pool uses the same discard limits as the underlying data
                 * device.  DM core has already set this up.