[PATCH 5.4 111/168] dm: fix congested_fn for request-based device

Greg Kroah-Hartman
2020-03-10T13:27:36Z

From: Hou Tao <houtao1@huawei.com>

commit 974f51e8633f0f3f33e8f86bbb5ae66758aa63c7 upstream.

We neither assign congested_fn for requested-based blk-mq device nor
implement it correctly. So fix both.

Also, remove incorrect comment from dm_init_normal_md_queue and rename
it to dm_init_congested_fn.

Fixes: 4aa9c692e052 ("bdi: separate out congested state into a separate struct")
Cc: stable@vger.kernel.org
Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/md/dm.c | 21 ++++++++++-----------
1 file changed, 10 insertions(+), 11 deletions(-)

--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1809,7 +1809,8 @@ static int dm_any_congested(void *conges
* With request-based DM we only need to check the
* top-level queue for congestion.
*/
- r = md->queue->backing_dev_info->wb.state & bdi_bits;
+ struct backing_dev_info *bdi = md->queue->backing_dev_info;
+ r = bdi->wb.congested->state & bdi_bits;
} else {
map = dm_get_live_table_fast(md);
if (map)
@@ -1875,15 +1876,6 @@ static const struct dax_operations dm_da

static void dm_wq_work(struct work_struct *work);

-static void dm_init_normal_md_queue(struct mapped_device *md)
-{
- /*
- * Initialize aspects of queue that aren't relevant for blk-mq
- */
- md->queue->backing_dev_info->congested_data = md;
- md->queue->backing_dev_info->congested_fn = dm_any_congested;
-}
-
static void cleanup_mapped_device(struct mapped_device *md)
{
if (md->wq)
@@ -2270,6 +2262,12 @@ struct queue_limits *dm_get_queue_limits
}
EXPORT_SYMBOL_GPL(dm_get_queue_limits);

+static void dm_init_congested_fn(struct mapped_device *md)
+{
+ md->queue->backing_dev_info->congested_data = md;
+ md->queue->backing_dev_info->congested_fn = dm_any_congested;
+}
+
/*
* Setup the DM device's queue based on md's type
*/
@@ -2286,11 +2284,12 @@ int dm_setup_md_queue(struct mapped_devi
DMERR("Cannot initialize queue for request-based dm-mq mapped device");
return r;
}
+ dm_init_congested_fn(md);
break;
case DM_TYPE_BIO_BASED:
case DM_TYPE_DAX_BIO_BASED:
case DM_TYPE_NVME_BIO_BASED:
- dm_init_normal_md_queue(md);
+ dm_init_congested_fn(md);
break;
case DM_TYPE_NONE:
WARN_ON_ONCE(true);