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authorChristoph Hellwig <hch@lst.de>2015-04-30 10:10:36 -0400
committerMike Snitzer <snitzer@redhat.com>2015-04-30 10:25:21 -0400
commit3e6180f0c82b3790a9ec6d13d67aae359bf1ce84 (patch)
treec4abf15202b194c0762f97af185e4b40387413ac
parentb787f68c36d49bb1d9236f403813641efa74a031 (diff)
downloadlinux-3e6180f0c82b3790a9ec6d13d67aae359bf1ce84.tar.bz2
dm: only initialize the request_queue once
Commit bfebd1cdb4 ("dm: add full blk-mq support to request-based DM") didn't properly account for the need to short-circuit re-initializing DM's blk-mq request_queue if it was already initialized. Otherwise, reloading a blk-mq request-based DM table (either manually or via multipathd) resulted in errors, see: https://www.redhat.com/archives/dm-devel/2015-April/msg00132.html Fix is to only initialize the request_queue on the initial table load (when the mapped_device type is assigned). This is better than having dm_init_request_based_blk_mq_queue() return early if the queue was already initialized because it elevates the constraint to a more meaningful location in DM core. As such the pre-existing early return in dm_init_request_based_queue() can now be removed. Fixes: bfebd1cdb4 ("dm: add full blk-mq support to request-based DM") Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
-rw-r--r--drivers/md/dm-ioctl.c17
-rw-r--r--drivers/md/dm.c3
2 files changed, 9 insertions, 11 deletions
diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
index c8a18e4ee9dc..720ceeb7fa9b 100644
--- a/drivers/md/dm-ioctl.c
+++ b/drivers/md/dm-ioctl.c
@@ -1298,21 +1298,22 @@ static int table_load(struct dm_ioctl *param, size_t param_size)
goto err_unlock_md_type;
}
- if (dm_get_md_type(md) == DM_TYPE_NONE)
+ if (dm_get_md_type(md) == DM_TYPE_NONE) {
/* Initial table load: acquire type of table. */
dm_set_md_type(md, dm_table_get_type(t));
- else if (dm_get_md_type(md) != dm_table_get_type(t)) {
+
+ /* setup md->queue to reflect md's type (may block) */
+ r = dm_setup_md_queue(md);
+ if (r) {
+ DMWARN("unable to set up device queue for new table.");
+ goto err_unlock_md_type;
+ }
+ } else if (dm_get_md_type(md) != dm_table_get_type(t)) {
DMWARN("can't change device type after initial table load.");
r = -EINVAL;
goto err_unlock_md_type;
}
- /* setup md->queue to reflect md's type (may block) */
- r = dm_setup_md_queue(md);
- if (r) {
- DMWARN("unable to set up device queue for new table.");
- goto err_unlock_md_type;
- }
dm_unlock_md_type(md);
/* stage inactive table */
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index f8c7ca3e8947..923496ba72a0 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -2662,9 +2662,6 @@ static int dm_init_request_based_queue(struct mapped_device *md)
{
struct request_queue *q = NULL;
- if (md->queue->elevator)
- return 0;
-
/* Fully initialize the queue */
q = blk_init_allocated_queue(md->queue, dm_request_fn, NULL);
if (!q)