[PATCH 23/30] block: kill legacy parts of timeout handling

Jens Axboe
2018-10-31T17:59:15Z

The only user of legacy timing now is BSG, which is invoked
from the mq timeout handler. Kill the legacy code, and rename
the q->rq_timed_out_fn to q->bsg_job_timeout_fn.

Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
block/blk-core.c | 1 -
block/blk-settings.c | 7 ---
block/blk-timeout.c | 99 +++---------------------------------------
block/blk.h | 1 -
block/bsg-lib.c | 6 +--
include/linux/blkdev.h | 4 +-
6 files changed, 11 insertions(+), 107 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index bffc80052948..fcdb631f0a7a 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -653,7 +653,6 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id,
laptop_mode_timer_fn, 0);
timer_setup(&q->timeout, blk_rq_timed_out_timer, 0);
INIT_WORK(&q->timeout_work, NULL);
- INIT_LIST_HEAD(&q->timeout_list);
INIT_LIST_HEAD(&q->icq_list);
#ifdef CONFIG_BLK_CGROUP
INIT_LIST_HEAD(&q->blkg_list);
diff --git a/block/blk-settings.c b/block/blk-settings.c
index f284e1600e29..1895f499bbe5 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -32,13 +32,6 @@ void blk_queue_rq_timeout(struct request_queue *q, unsigned int timeout)
}
EXPORT_SYMBOL_GPL(blk_queue_rq_timeout);

-void blk_queue_rq_timed_out(struct request_queue *q, rq_timed_out_fn *fn)
-{
- WARN_ON_ONCE(q->mq_ops);
- q->rq_timed_out_fn = fn;
-}
-EXPORT_SYMBOL_GPL(blk_queue_rq_timed_out);
-
/**
* blk_set_default_limits - reset limits to default values
* @lim: the queue_limits structure to reset
diff --git a/block/blk-timeout.c b/block/blk-timeout.c
index f2cfd56e1606..6428d458072a 100644
--- a/block/blk-timeout.c
+++ b/block/blk-timeout.c
@@ -78,70 +78,6 @@ void blk_delete_timer(struct request *req)
list_del_init(&req->timeout_list);
}

-static void blk_rq_timed_out(struct request *req)
-{
- struct request_queue *q = req->q;
- enum blk_eh_timer_return ret = BLK_EH_RESET_TIMER;
-
- if (q->rq_timed_out_fn)
- ret = q->rq_timed_out_fn(req);
- switch (ret) {
- case BLK_EH_RESET_TIMER:
- blk_add_timer(req);
- blk_clear_rq_complete(req);
- break;
- case BLK_EH_DONE:
- /*
- * LLD handles this for now but in the future
- * we can send a request msg to abort the command
- * and we can move more of the generic scsi eh code to
- * the blk layer.
- */
- break;
- default:
- printk(KERN_ERR "block: bad eh return: %d\n", ret);
- break;
- }
-}
-
-static void blk_rq_check_expired(struct request *rq, unsigned long *next_timeout,
- unsigned int *next_set)
-{
- const unsigned long deadline = blk_rq_deadline(rq);
-
- if (time_after_eq(jiffies, deadline)) {
- list_del_init(&rq->timeout_list);
-
- /*
- * Check if we raced with end io completion
- */
- if (!blk_mark_rq_complete(rq))
- blk_rq_timed_out(rq);
- } else if (!*next_set || time_after(*next_timeout, deadline)) {
- *next_timeout = deadline;
- *next_set = 1;
- }
-}
-
-void blk_timeout_work(struct work_struct *work)
-{
- struct request_queue *q =
- container_of(work, struct request_queue, timeout_work);
- unsigned long flags, next = 0;
- struct request *rq, *tmp;
- int next_set = 0;
-
- spin_lock_irqsave(q->queue_lock, flags);
-
- list_for_each_entry_safe(rq, tmp, &q->timeout_list, timeout_list)
- blk_rq_check_expired(rq, &next, &next_set);
-
- if (next_set)
- mod_timer(&q->timeout, round_jiffies_up(next));
-
- spin_unlock_irqrestore(q->queue_lock, flags);
-}
-
/**
* blk_abort_request -- Request request recovery for the specified command
* @req: pointer to the request of interest
@@ -153,20 +89,13 @@ void blk_timeout_work(struct work_struct *work)
*/
void blk_abort_request(struct request *req)
{
- if (req->q->mq_ops) {
- /*
- * All we need to ensure is that timeout scan takes place
- * immediately and that scan sees the new timeout value.
- * No need for fancy synchronizations.
- */
- blk_rq_set_deadline(req, jiffies);
- kblockd_schedule_work(&req->q->timeout_work);
- } else {
- if (blk_mark_rq_complete(req))
- return;
- blk_delete_timer(req);
- blk_rq_timed_out(req);
- }
+ /*
+ * All we need to ensure is that timeout scan takes place
+ * immediately and that scan sees the new timeout value.
+ * No need for fancy synchronizations.
+ */
+ blk_rq_set_deadline(req, jiffies);
+ kblockd_schedule_work(&req->q->timeout_work);
}
EXPORT_SYMBOL_GPL(blk_abort_request);

@@ -194,13 +123,6 @@ void blk_add_timer(struct request *req)
struct request_queue *q = req->q;
unsigned long expiry;

- if (!q->mq_ops)
- lockdep_assert_held(q->queue_lock);
-
- /* blk-mq has its own handler, so we don't need ->rq_timed_out_fn */
- if (!q->mq_ops && !q->rq_timed_out_fn)
- return;
-
BUG_ON(!list_empty(&req->timeout_list));

/*
@@ -213,13 +135,6 @@ void blk_add_timer(struct request *req)
req->rq_flags &= ~RQF_TIMED_OUT;
blk_rq_set_deadline(req, jiffies + req->timeout);

- /*
- * Only the non-mq case needs to add the request to a protected list.
- * For the mq case we simply scan the tag map.
- */
- if (!q->mq_ops)
- list_add_tail(&req->timeout_list, &req->q->timeout_list);
-
/*
* If the timer isn't already pending or this timeout is earlier
* than an existing one, modify the timer. Round up to next nearest
diff --git a/block/blk.h b/block/blk.h
index e2604ae7ddfa..4ae6cacb4548 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -224,7 +224,6 @@ static inline bool bio_integrity_endio(struct bio *bio)
}
#endif /* CONFIG_BLK_DEV_INTEGRITY */

-void blk_timeout_work(struct work_struct *work);
unsigned long blk_rq_timeout(unsigned long timeout);
void blk_add_timer(struct request *req);
void blk_delete_timer(struct request *);
diff --git a/block/bsg-lib.c b/block/bsg-lib.c
index faf20f4500c9..f38c7bc272c0 100644
--- a/block/bsg-lib.c
+++ b/block/bsg-lib.c
@@ -307,8 +307,8 @@ static enum blk_eh_timer_return bsg_timeout(struct request *rq, bool reserved)
enum blk_eh_timer_return ret = BLK_EH_DONE;
struct request_queue *q = rq->q;

- if (q->rq_timed_out_fn)
- ret = q->rq_timed_out_fn(rq);
+ if (q->bsg_job_timeout_fn)
+ ret = q->bsg_job_timeout_fn(rq);

return ret;
}
@@ -357,9 +357,9 @@ struct request_queue *bsg_setup_queue(struct device *dev, const char *name,

q->queuedata = dev;
q->bsg_job_fn = job_fn;
+ q->bsg_job_timeout_fn = timeout;
blk_queue_flag_set(QUEUE_FLAG_BIDI, q);
blk_queue_rq_timeout(q, BLK_DEFAULT_SG_TIMEOUT);
- q->rq_timed_out_fn = timeout;

ret = bsg_register_queue(q, dev, name, &bsg_transport_ops);
if (ret) {
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index c502a7f40e84..0364fc53f5c8 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -441,7 +441,6 @@ struct request_queue {
make_request_fn *make_request_fn;
poll_q_fn *poll_fn;
softirq_done_fn *softirq_done_fn;
- rq_timed_out_fn *rq_timed_out_fn;
dma_drain_needed_fn *dma_drain_needed;
/* Called just after a request is allocated */
init_rq_fn *init_rq_fn;
@@ -541,7 +540,6 @@ struct request_queue {

struct timer_list timeout;
struct work_struct timeout_work;
- struct list_head timeout_list;

struct list_head icq_list;
#ifdef CONFIG_BLK_CGROUP
@@ -601,6 +599,7 @@ struct request_queue {

#if defined(CONFIG_BLK_DEV_BSG)
bsg_job_fn *bsg_job_fn;
+ rq_timed_out_fn *bsg_job_timeout_fn;
struct bsg_class_device bsg_dev;
#endif

@@ -1156,7 +1155,6 @@ extern void blk_queue_virt_boundary(struct request_queue *, unsigned long);
extern void blk_queue_dma_alignment(struct request_queue *, int);
extern void blk_queue_update_dma_alignment(struct request_queue *, int);
extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
-extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
extern void blk_queue_flush_queueable(struct request_queue *q, bool queueable);
extern void blk_queue_write_cache(struct request_queue *q, bool enabled, bool fua);
--
2.17.1