[PATCH 6/6] mmc: stop abusing the request queue_lock pointer

Christoph Hellwig
2018-11-16T08:10:27Z

Replace the lock in mmc_blk_data that is only used through a pointer
in struct mmc_queue and to protect fields in that structure with
an actual lock in struct mmc_queue.

Suggested-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
drivers/mmc/core/block.c | 24 +++++++++++-------------
drivers/mmc/core/queue.c | 31 +++++++++++++++----------------
drivers/mmc/core/queue.h | 4 ++--
3 files changed, 28 insertions(+), 31 deletions(-)

diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
index 70ec465beb69..2c329a3e3fdb 100644
--- a/drivers/mmc/core/block.c
+++ b/drivers/mmc/core/block.c
@@ -100,7 +100,6 @@ static DEFINE_IDA(mmc_rpmb_ida);
* There is one mmc_blk_data per slot.
*/
struct mmc_blk_data {
- spinlock_t lock;
struct device *parent;
struct gendisk *disk;
struct mmc_queue queue;
@@ -1483,7 +1482,7 @@ static void mmc_blk_cqe_complete_rq(struct mmc_queue *mq, struct request *req)
blk_mq_end_request(req, BLK_STS_OK);
}

- spin_lock_irqsave(mq->lock, flags);
+ spin_lock_irqsave(&mq->lock, flags);

mq->in_flight[mmc_issue_type(mq, req)] -= 1;

@@ -1491,7 +1490,7 @@ static void mmc_blk_cqe_complete_rq(struct mmc_queue *mq, struct request *req)

mmc_cqe_check_busy(mq);

- spin_unlock_irqrestore(mq->lock, flags);
+ spin_unlock_irqrestore(&mq->lock, flags);

if (!mq->cqe_busy)
blk_mq_run_hw_queues(q, true);
@@ -1991,13 +1990,13 @@ static void mmc_blk_mq_dec_in_flight(struct mmc_queue *mq, struct request *req)
unsigned long flags;
bool put_card;

- spin_lock_irqsave(mq->lock, flags);
+ spin_lock_irqsave(&mq->lock, flags);

mq->in_flight[mmc_issue_type(mq, req)] -= 1;

put_card = (mmc_tot_in_flight(mq) == 0);

- spin_unlock_irqrestore(mq->lock, flags);
+ spin_unlock_irqrestore(&mq->lock, flags);

if (put_card)
mmc_put_card(mq->card, &mq->ctx);
@@ -2093,11 +2092,11 @@ static void mmc_blk_mq_req_done(struct mmc_request *mrq)
* request does not need to wait (although it does need to
* complete complete_req first).
*/
- spin_lock_irqsave(mq->lock, flags);
+ spin_lock_irqsave(&mq->lock, flags);
mq->complete_req = req;
mq->rw_wait = false;
waiting = mq->waiting;
- spin_unlock_irqrestore(mq->lock, flags);
+ spin_unlock_irqrestore(&mq->lock, flags);

/*
* If 'waiting' then the waiting task will complete this
@@ -2116,10 +2115,10 @@ static void mmc_blk_mq_req_done(struct mmc_request *mrq)
/* Take the recovery path for errors or urgent background operations */
if (mmc_blk_rq_error(&mqrq->brq) ||
mmc_blk_urgent_bkops_needed(mq, mqrq)) {
- spin_lock_irqsave(mq->lock, flags);
+ spin_lock_irqsave(&mq->lock, flags);
mq->recovery_needed = true;
mq->recovery_req = req;
- spin_unlock_irqrestore(mq->lock, flags);
+ spin_unlock_irqrestore(&mq->lock, flags);
wake_up(&mq->wait);
schedule_work(&mq->recovery_work);
return;
@@ -2142,7 +2141,7 @@ static bool mmc_blk_rw_wait_cond(struct mmc_queue *mq, int *err)
* Wait while there is another request in progress, but not if recovery
* is needed. Also indicate whether there is a request waiting to start.
*/
- spin_lock_irqsave(mq->lock, flags);
+ spin_lock_irqsave(&mq->lock, flags);
if (mq->recovery_needed) {
*err = -EBUSY;
done = true;
@@ -2150,7 +2149,7 @@ static bool mmc_blk_rw_wait_cond(struct mmc_queue *mq, int *err)
done = !mq->rw_wait;
}
mq->waiting = !done;
- spin_unlock_irqrestore(mq->lock, flags);
+ spin_unlock_irqrestore(&mq->lock, flags);

return done;
}
@@ -2327,12 +2326,11 @@ static struct mmc_blk_data *mmc_blk_alloc_req(struct mmc_card *card,
goto err_kfree;
}

- spin_lock_init(&md->lock);
INIT_LIST_HEAD(&md->part);
INIT_LIST_HEAD(&md->rpmbs);
md->usage = 1;

- ret = mmc_init_queue(&md->queue, card, &md->lock);
+ ret = mmc_init_queue(&md->queue, card);
if (ret)
goto err_putdisk;

diff --git a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c
index 4485cf12218c..35cc138b096d 100644
--- a/drivers/mmc/core/queue.c
+++ b/drivers/mmc/core/queue.c
@@ -89,9 +89,9 @@ void mmc_cqe_recovery_notifier(struct mmc_request *mrq)
struct mmc_queue *mq = q->queuedata;
unsigned long flags;

- spin_lock_irqsave(mq->lock, flags);
+ spin_lock_irqsave(&mq->lock, flags);
__mmc_cqe_recovery_notifier(mq);
- spin_unlock_irqrestore(mq->lock, flags);
+ spin_unlock_irqrestore(&mq->lock, flags);
}

static enum blk_eh_timer_return mmc_cqe_timed_out(struct request *req)
@@ -128,14 +128,14 @@ static enum blk_eh_timer_return mmc_mq_timed_out(struct request *req,
unsigned long flags;
int ret;

- spin_lock_irqsave(mq->lock, flags);
+ spin_lock_irqsave(&mq->lock, flags);

if (mq->recovery_needed || !mq->use_cqe)
ret = BLK_EH_RESET_TIMER;
else
ret = mmc_cqe_timed_out(req);

- spin_unlock_irqrestore(mq->lock, flags);
+ spin_unlock_irqrestore(&mq->lock, flags);

return ret;
}
@@ -157,9 +157,9 @@ static void mmc_mq_recovery_handler(struct work_struct *work)

mq->in_recovery = false;

- spin_lock_irq(mq->lock);
+ spin_lock_irq(&mq->lock);
mq->recovery_needed = false;
- spin_unlock_irq(mq->lock);
+ spin_unlock_irq(&mq->lock);

mmc_put_card(mq->card, &mq->ctx);

@@ -258,10 +258,10 @@ static blk_status_t mmc_mq_queue_rq(struct blk_mq_hw_ctx *hctx,

issue_type = mmc_issue_type(mq, req);

- spin_lock_irq(mq->lock);
+ spin_lock_irq(&mq->lock);

if (mq->recovery_needed || mq->busy) {
- spin_unlock_irq(mq->lock);
+ spin_unlock_irq(&mq->lock);
return BLK_STS_RESOURCE;
}

@@ -269,7 +269,7 @@ static blk_status_t mmc_mq_queue_rq(struct blk_mq_hw_ctx *hctx,
case MMC_ISSUE_DCMD:
if (mmc_cqe_dcmd_busy(mq)) {
mq->cqe_busy |= MMC_CQE_DCMD_BUSY;
- spin_unlock_irq(mq->lock);
+ spin_unlock_irq(&mq->lock);
return BLK_STS_RESOURCE;
}
break;
@@ -294,7 +294,7 @@ static blk_status_t mmc_mq_queue_rq(struct blk_mq_hw_ctx *hctx,
get_card = (mmc_tot_in_flight(mq) == 1);
cqe_retune_ok = (mmc_cqe_qcnt(mq) == 1);

- spin_unlock_irq(mq->lock);
+ spin_unlock_irq(&mq->lock);

if (!(req->rq_flags & RQF_DONTPREP)) {
req_to_mmc_queue_req(req)->retries = 0;
@@ -328,12 +328,12 @@ static blk_status_t mmc_mq_queue_rq(struct blk_mq_hw_ctx *hctx,
if (issued != MMC_REQ_STARTED) {
bool put_card = false;

- spin_lock_irq(mq->lock);
+ spin_lock_irq(&mq->lock);
mq->in_flight[issue_type] -= 1;
if (mmc_tot_in_flight(mq) == 0)
put_card = true;
mq->busy = false;
- spin_unlock_irq(mq->lock);
+ spin_unlock_irq(&mq->lock);
if (put_card)
mmc_put_card(card, &mq->ctx);
} else {
@@ -385,19 +385,18 @@ static void mmc_setup_queue(struct mmc_queue *mq, struct mmc_card *card)
* mmc_init_queue - initialise a queue structure.
* @mq: mmc queue
* @card: mmc card to attach this queue
- * @lock: queue lock
*
* Initialise a MMC card request queue.
*/
-int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,
- spinlock_t *lock)
+int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card)
{
struct mmc_host *host = card->host;
int ret;

mq->card = card;
- mq->lock = lock;
mq->use_cqe = host->cqe_enabled;
+
+ spin_lock_init(&mq->lock);

memset(&mq->tag_set, 0, sizeof(mq->tag_set));
mq->tag_set.ops = &mmc_mq_ops;
diff --git a/drivers/mmc/core/queue.h b/drivers/mmc/core/queue.h
index 5421f1542e71..fd11491ced9f 100644
--- a/drivers/mmc/core/queue.h
+++ b/drivers/mmc/core/queue.h
@@ -73,11 +73,11 @@ struct mmc_queue_req {

struct mmc_queue {
struct mmc_card *card;
- spinlock_t *lock;
struct mmc_ctx ctx;
struct blk_mq_tag_set tag_set;
struct mmc_blk_data *blkdata;
struct request_queue *queue;
+ spinlock_t lock;
int in_flight[MMC_ISSUE_MAX];
unsigned int cqe_busy;
#define MMC_CQE_DCMD_BUSY BIT(0)
@@ -96,7 +96,7 @@ struct mmc_queue {
struct work_struct complete_work;
};

-extern int mmc_init_queue(struct mmc_queue *, struct mmc_card *, spinlock_t *);
+extern int mmc_init_queue(struct mmc_queue *, struct mmc_card *);
extern void mmc_cleanup_queue(struct mmc_queue *);
extern void mmc_queue_suspend(struct mmc_queue *);
extern void mmc_queue_resume(struct mmc_queue *);
--
2.19.1