[PATCH V14 06/24] mmc: block: Simplify cleaning up the queue

Adrian Hunter
2017-11-21T13:42:32Z

Use blk_cleanup_queue() to shutdown the queue when the driver is removed,
and instead get an extra reference to the queue to prevent the queue being
freed before the final mmc_blk_put().

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
drivers/mmc/core/block.c | 17 ++++++++++++-----
drivers/mmc/core/queue.c | 2 ++
2 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
index ccfa98af1dd3..e44f6d90aeb4 100644
--- a/drivers/mmc/core/block.c
+++ b/drivers/mmc/core/block.c
@@ -189,7 +189,7 @@ static void mmc_blk_put(struct mmc_blk_data *md)
md->usage--;
if (md->usage == 0) {
int devidx = mmc_get_devidx(md->disk);
- blk_cleanup_queue(md->queue.queue);
+ blk_put_queue(md->queue.queue);
ida_simple_remove(&mmc_blk_ida, devidx);
put_disk(md->disk);
kfree(md);
@@ -2156,6 +2156,17 @@ static struct mmc_blk_data *mmc_blk_alloc_req(struct mmc_card *card,

md->queue.blkdata = md;

+ /*
+ * Keep an extra reference to the queue so that we can shutdown the
+ * queue (i.e. call blk_cleanup_queue()) while there are still
+ * references to the 'md'. The corresponding blk_put_queue() is in
+ * mmc_blk_put().
+ */
+ if (!blk_get_queue(md->queue.queue)) {
+ mmc_cleanup_queue(&md->queue);
+ goto err_putdisk;
+ }
+
md->disk->major = MMC_BLOCK_MAJOR;
md->disk->first_minor = devidx * perdev_minors;
md->disk->fops = &mmc_bdops;
@@ -2471,10 +2482,6 @@ static void mmc_blk_remove_req(struct mmc_blk_data *md)
* from being accepted.
*/
card = md->queue.card;
- spin_lock_irq(md->queue.queue->queue_lock);
- queue_flag_set(QUEUE_FLAG_BYPASS, md->queue.queue);
- spin_unlock_irq(md->queue.queue->queue_lock);
- blk_set_queue_dying(md->queue.queue);
mmc_cleanup_queue(&md->queue);
if (md->disk->flags & GENHD_FL_UP) {
device_remove_file(disk_to_dev(md->disk), &md->force_ro);
diff --git a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c
index 26f8da30ebe5..ae6d9da68735 100644
--- a/drivers/mmc/core/queue.c
+++ b/drivers/mmc/core/queue.c
@@ -268,6 +268,8 @@ void mmc_cleanup_queue(struct mmc_queue *mq)
blk_start_queue(q);
spin_unlock_irqrestore(q->queue_lock, flags);

+ blk_cleanup_queue(q);
+
mq->card = NULL;
}

--
1.9.1