[PATCH 5/6] blk-mq: unshared timeout handler

From: Christoph Hellwig
Date: Sat Sep 13 2014 - 19:38:48 EST


Duplicate the (small) timeout handler in blk-mq so that we can pass
arguments more easily to the driver timeout handler. This enables
the next patch.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
block/blk-mq.c | 53 +++++++++++++++++++++++++++++++++++++----------------
block/blk-timeout.c | 8 ++------
block/blk.h | 2 --
3 files changed, 39 insertions(+), 24 deletions(-)

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 2d96b0d..c14d397 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -511,9 +511,15 @@ struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag)
}
EXPORT_SYMBOL(blk_mq_tag_to_rq);

-static enum blk_eh_timer_return blk_mq_rq_timed_out(struct request *rq)
+struct blk_mq_timeout_data {
+ unsigned long next;
+ unsigned int next_set;
+};
+
+static void blk_mq_rq_timed_out(struct request *req)
{
- struct request_queue *q = rq->q;
+ struct blk_mq_ops *ops = req->q->mq_ops;
+ enum blk_eh_timer_return ret = BLK_EH_RESET_TIMER;

/*
* We know that complete is set at this point. If STARTED isn't set
@@ -524,27 +530,43 @@ static enum blk_eh_timer_return blk_mq_rq_timed_out(struct request *rq)
* we both flags will get cleared. So check here again, and ignore
* a timeout event with a request that isn't active.
*/
- if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags))
- return BLK_EH_NOT_HANDLED;
-
- if (!q->mq_ops->timeout)
- return BLK_EH_RESET_TIMER;
+ if (!test_bit(REQ_ATOM_STARTED, &req->atomic_flags))
+ return;

- return q->mq_ops->timeout(rq);
+ if (ops->timeout)
+ ret = ops->timeout(req);
+
+ switch (ret) {
+ case BLK_EH_HANDLED:
+ __blk_mq_complete_request(req);
+ break;
+ case BLK_EH_RESET_TIMER:
+ blk_add_timer(req);
+ blk_clear_rq_complete(req);
+ break;
+ case BLK_EH_NOT_HANDLED:
+ break;
+ default:
+ printk(KERN_ERR "block: bad eh return: %d\n", ret);
+ break;
+ }
}

-struct blk_mq_timeout_data {
- unsigned long next;
- unsigned int next_set;
-};
-
static void blk_mq_check_expired(struct blk_mq_hw_ctx *hctx,
struct request *rq, void *priv, bool reserved)
{
struct blk_mq_timeout_data *data = priv;

- if (test_bit(REQ_ATOM_STARTED, &rq->atomic_flags))
- blk_rq_check_expired(rq, &data->next, &data->next_set);
+ if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags))
+ return;
+
+ if (time_after_eq(jiffies, rq->deadline)) {
+ if (!blk_mark_rq_complete(rq))
+ blk_mq_rq_timed_out(rq);
+ } else if (!data->next_set || time_after(data->next, rq->deadline)) {
+ data->next = rq->deadline;
+ data->next_set = 1;
+ }
}

static void blk_mq_rq_timer(unsigned long priv)
@@ -1770,7 +1792,6 @@ struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set)
else
blk_queue_make_request(q, blk_sq_make_request);

- blk_queue_rq_timed_out(q, blk_mq_rq_timed_out);
if (set->timeout)
blk_queue_rq_timeout(q, set->timeout);

diff --git a/block/blk-timeout.c b/block/blk-timeout.c
index 95a0959..4d44825 100644
--- a/block/blk-timeout.c
+++ b/block/blk-timeout.c
@@ -7,7 +7,6 @@
#include <linux/fault-inject.h>

#include "blk.h"
-#include "blk-mq.h"

#ifdef CONFIG_FAIL_IO_TIMEOUT

@@ -90,10 +89,7 @@ static void blk_rq_timed_out(struct request *req)
switch (ret) {
case BLK_EH_HANDLED:
/* Can we use req->errors here? */
- if (q->mq_ops)
- __blk_mq_complete_request(req);
- else
- __blk_complete_request(req);
+ __blk_complete_request(req);
break;
case BLK_EH_RESET_TIMER:
blk_add_timer(req);
@@ -113,7 +109,7 @@ static void blk_rq_timed_out(struct request *req)
}
}

-void blk_rq_check_expired(struct request *rq, unsigned long *next_timeout,
+static void blk_rq_check_expired(struct request *rq, unsigned long *next_timeout,
unsigned int *next_set)
{
if (time_after_eq(jiffies, rq->deadline)) {
diff --git a/block/blk.h b/block/blk.h
index 6748c4f..e515a28 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -38,8 +38,6 @@ bool __blk_end_bidi_request(struct request *rq, int error,
unsigned int nr_bytes, unsigned int bidi_bytes);

void blk_rq_timed_out_timer(unsigned long data);
-void blk_rq_check_expired(struct request *rq, unsigned long *next_timeout,
- unsigned int *next_set);
unsigned long blk_rq_timeout(unsigned long timeout);
void blk_add_timer(struct request *req);
void blk_delete_timer(struct request *);
--
1.9.1

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