dm-table: fix checking for rq stackable devices

Due to the semantics of iterate_devices(), the current code allows a
request-based dm table as long as it includes one request-stackable
device. It is supposed to only allow tables where there are no
non-request-stackable devices.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Reviewed-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>

diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 24a857ff6d0b1dac8687bc10cc948d3c0fd36c7a..79ba4bacd0f9a964338a3b1955fcb94506b56bbc 100644 (file)
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -899,17 +899,17 @@ static bool dm_table_supports_dax(struct dm_table *t,
        return true;
 }
 
-static int device_is_rq_stackable(struct dm_target *ti, struct dm_dev *dev,
-                                 sector_t start, sector_t len, void *data)
+static int device_is_not_rq_stackable(struct dm_target *ti, struct dm_dev *dev,
+                                     sector_t start, sector_t len, void *data)
 {
        struct block_device *bdev = dev->bdev;
        struct request_queue *q = bdev_get_queue(bdev);
 
        /* request-based cannot stack on partitions! */
        if (bdev_is_partition(bdev))
-               return false;
+               return true;
 
-       return queue_is_mq(q);
+       return !queue_is_mq(q);
 }
 
 static int dm_table_determine_type(struct dm_table *t)
@@ -1005,7 +1005,7 @@ verify_rq_based:
 
        /* Non-request-stackable devices can't be used for request-based dm */
        if (!ti->type->iterate_devices ||
-           !ti->type->iterate_devices(ti, device_is_rq_stackable, NULL)) {
+           ti->type->iterate_devices(ti, device_is_not_rq_stackable, NULL)) {
                DMERR("table load rejected: including non-request-stackable devices");
                return -EINVAL;
        }