[PATCH 23/23] block: remove the errors field from struct request

Christoph Hellwig
2017-04-20T14:03:16Z

Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
---
block/blk-core.c | 14 +-------------
block/blk-exec.c | 3 +--
block/blk-mq.c | 10 +++-------
block/blk-timeout.c | 1 -
include/linux/blkdev.h | 2 --
include/trace/events/block.h | 17 +++++++----------
kernel/trace/blktrace.c | 26 ++++++++++++--------------
7 files changed, 24 insertions(+), 49 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index 25aea293ee98..a49b0830aaaf 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1635,7 +1635,6 @@ void blk_init_request_from_bio(struct request *req, struct bio *bio)
if (bio->bi_opf & REQ_RAHEAD)
req->cmd_flags |= REQ_FAILFAST_MASK;

- req->errors = 0;
req->__sector = bio->bi_iter.bi_sector;
if (ioprio_valid(bio_prio(bio)))
req->ioprio = bio_prio(bio);
@@ -2573,22 +2572,11 @@ bool blk_update_request(struct request *req, int error, unsigned int nr_bytes)
{
int total_bytes;

- trace_block_rq_complete(req->q, req, nr_bytes);
+ trace_block_rq_complete(req, error, nr_bytes);

if (!req->bio)
return false;

- /*
- * For fs requests, rq is just carrier of independent bio's
- * and each partial completion should be handled separately.
- * Reset per-request error on each partial completion.
- *
- * TODO: tj: This is too subtle. It would be better to let
- * low level drivers do what they see fit.
- */
- if (!blk_rq_is_passthrough(req))
- req->errors = 0;
-
if (error && !blk_rq_is_passthrough(req) &&
!(req->rq_flags & RQF_QUIET)) {
char *error_type;
diff --git a/block/blk-exec.c b/block/blk-exec.c
index afa383248c7c..a9451e3b8587 100644
--- a/block/blk-exec.c
+++ b/block/blk-exec.c
@@ -69,8 +69,7 @@ void blk_execute_rq_nowait(struct request_queue *q, struct gendisk *bd_disk,

if (unlikely(blk_queue_dying(q))) {
rq->rq_flags |= RQF_QUIET;
- rq->errors = -ENXIO;
- __blk_end_request_all(rq, rq->errors);
+ __blk_end_request_all(rq, -ENXIO);
spin_unlock_irq(q->queue_lock);
return;
}
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 3a21948c867a..f2f6c59c5b05 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -213,7 +213,6 @@ void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx,
#endif
rq->special = NULL;
/* tag was already set */
- rq->errors = 0;
rq->extra_len = 0;

INIT_LIST_HEAD(&rq->timeout_list);
@@ -624,8 +623,7 @@ void blk_mq_abort_requeue_list(struct request_queue *q)

rq = list_first_entry(&rq_list, struct request, queuelist);
list_del_init(&rq->queuelist);
- rq->errors = -EIO;
- blk_mq_end_request(rq, rq->errors);
+ blk_mq_end_request(rq, -EIO);
}
}
EXPORT_SYMBOL(blk_mq_abort_requeue_list);
@@ -1032,8 +1030,7 @@ bool blk_mq_dispatch_rq_list(struct request_queue *q, struct list_head *list)
pr_err("blk-mq: bad return on queue: %d\n", ret);
case BLK_MQ_RQ_QUEUE_ERROR:
errors++;
- rq->errors = -EIO;
- blk_mq_end_request(rq, rq->errors);
+ blk_mq_end_request(rq, -EIO);
break;
}

@@ -1484,8 +1481,7 @@ static void __blk_mq_try_issue_directly(struct request *rq, blk_qc_t *cookie,

if (ret == BLK_MQ_RQ_QUEUE_ERROR) {
*cookie = BLK_QC_T_NONE;
- rq->errors = -EIO;
- blk_mq_end_request(rq, rq->errors);
+ blk_mq_end_request(rq, -EIO);
return;
}

diff --git a/block/blk-timeout.c b/block/blk-timeout.c
index a30441a200c0..cbff183f3d9f 100644
--- a/block/blk-timeout.c
+++ b/block/blk-timeout.c
@@ -89,7 +89,6 @@ static void blk_rq_timed_out(struct request *req)
ret = q->rq_timed_out_fn(req);
switch (ret) {
case BLK_EH_HANDLED:
- /* Can we use req->errors here? */
__blk_complete_request(req);
break;
case BLK_EH_RESET_TIMER:
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index a3dcee624de3..6c4ab0d4a160 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -220,8 +220,6 @@ struct request {

void *special; /* opaque pointer available for LLD use */

- int errors;
-
unsigned int extra_len; /* length of alignment and padding */

unsigned long deadline;
diff --git a/include/trace/events/block.h b/include/trace/events/block.h
index 99ed69fad041..d0dbe60d8a6d 100644
--- a/include/trace/events/block.h
+++ b/include/trace/events/block.h
@@ -80,7 +80,6 @@ TRACE_EVENT(block_rq_requeue,
__field( dev_t, dev )
__field( sector_t, sector )
__field( unsigned int, nr_sector )
- __field( int, errors )
__array( char, rwbs, RWBS_LEN )
__dynamic_array( char, cmd, 1 )
),
@@ -89,7 +88,6 @@ TRACE_EVENT(block_rq_requeue,
__entry->dev = rq->rq_disk ? disk_devt(rq->rq_disk) : 0;
__entry->sector = blk_rq_trace_sector(rq);
__entry->nr_sector = blk_rq_trace_nr_sectors(rq);
- __entry->errors = rq->errors;

blk_fill_rwbs(__entry->rwbs, rq->cmd_flags, blk_rq_bytes(rq));
__get_str(cmd)[0] = '\0';
@@ -99,13 +97,13 @@ TRACE_EVENT(block_rq_requeue,
MAJOR(__entry->dev), MINOR(__entry->dev),
__entry->rwbs, __get_str(cmd),
(unsigned long long)__entry->sector,
- __entry->nr_sector, __entry->errors)
+ __entry->nr_sector, 0)
);

/**
* block_rq_complete - block IO operation completed by device driver
- * @q: queue containing the block operation request
* @rq: block operations request
+ * @error: status code
* @nr_bytes: number of completed bytes
*
* The block_rq_complete tracepoint event indicates that some portion
@@ -116,16 +114,15 @@ TRACE_EVENT(block_rq_requeue,
*/
TRACE_EVENT(block_rq_complete,

- TP_PROTO(struct request_queue *q, struct request *rq,
- unsigned int nr_bytes),
+ TP_PROTO(struct request *rq, int error, unsigned int nr_bytes),

- TP_ARGS(q, rq, nr_bytes),
+ TP_ARGS(rq, error, nr_bytes),

TP_STRUCT__entry(
__field( dev_t, dev )
__field( sector_t, sector )
__field( unsigned int, nr_sector )
- __field( int, errors )
+ __field( int, error )
__array( char, rwbs, RWBS_LEN )
__dynamic_array( char, cmd, 1 )
),
@@ -134,7 +131,7 @@ TRACE_EVENT(block_rq_complete,
__entry->dev = rq->rq_disk ? disk_devt(rq->rq_disk) : 0;
__entry->sector = blk_rq_pos(rq);
__entry->nr_sector = nr_bytes >> 9;
- __entry->errors = rq->errors;
+ __entry->error = error;

blk_fill_rwbs(__entry->rwbs, rq->cmd_flags, nr_bytes);
__get_str(cmd)[0] = '\0';
@@ -144,7 +141,7 @@ TRACE_EVENT(block_rq_complete,
MAJOR(__entry->dev), MINOR(__entry->dev),
__entry->rwbs, __get_str(cmd),
(unsigned long long)__entry->sector,
- __entry->nr_sector, __entry->errors)
+ __entry->nr_sector, __entry->error)
);

DECLARE_EVENT_CLASS(block_rq,
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 9f3624dadb09..bd8ae8d5ae9c 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -690,8 +690,8 @@ void blk_trace_shutdown(struct request_queue *q)

/**
* blk_add_trace_rq - Add a trace for a request oriented action
- * @q: queue the io is for
* @rq: the source request
+ * @error: return status to log
* @nr_bytes: number of completed bytes
* @what: the action
*
@@ -699,10 +699,10 @@ void blk_trace_shutdown(struct request_queue *q)
* Records an action against a request. Will log the bio offset + size.
*
**/
-static void blk_add_trace_rq(struct request_queue *q, struct request *rq,
+static void blk_add_trace_rq(struct request *rq, int error,
unsigned int nr_bytes, u32 what)
{
- struct blk_trace *bt = q->blk_trace;
+ struct blk_trace *bt = rq->q->blk_trace;

if (likely(!bt))
return;
@@ -713,34 +713,32 @@ static void blk_add_trace_rq(struct request_queue *q, struct request *rq,
what |= BLK_TC_ACT(BLK_TC_FS);

__blk_add_trace(bt, blk_rq_trace_sector(rq), nr_bytes, req_op(rq),
- rq->cmd_flags, what, rq->errors, 0, NULL);
+ rq->cmd_flags, what, error, 0, NULL);
}

static void blk_add_trace_rq_insert(void *ignore,
struct request_queue *q, struct request *rq)
{
- blk_add_trace_rq(q, rq, blk_rq_bytes(rq), BLK_TA_INSERT);
+ blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_INSERT);
}

static void blk_add_trace_rq_issue(void *ignore,
struct request_queue *q, struct request *rq)
{
- blk_add_trace_rq(q, rq, blk_rq_bytes(rq), BLK_TA_ISSUE);
+ blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_ISSUE);
}

static void blk_add_trace_rq_requeue(void *ignore,
struct request_queue *q,
struct request *rq)
{
- blk_add_trace_rq(q, rq, blk_rq_bytes(rq), BLK_TA_REQUEUE);
+ blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_REQUEUE);
}

-static void blk_add_trace_rq_complete(void *ignore,
- struct request_queue *q,
- struct request *rq,
- unsigned int nr_bytes)
+static void blk_add_trace_rq_complete(void *ignore, struct request *rq,
+ int error, unsigned int nr_bytes)
{
- blk_add_trace_rq(q, rq, nr_bytes, BLK_TA_COMPLETE);
+ blk_add_trace_rq(rq, error, nr_bytes, BLK_TA_COMPLETE);
}

/**
@@ -935,7 +933,7 @@ static void blk_add_trace_rq_remap(void *ignore,
r.sector_from = cpu_to_be64(from);

__blk_add_trace(bt, blk_rq_pos(rq), blk_rq_bytes(rq),
- rq_data_dir(rq), 0, BLK_TA_REMAP, !!rq->errors,
+ rq_data_dir(rq), 0, BLK_TA_REMAP, 0,
sizeof(r), &r);
}

@@ -960,7 +958,7 @@ void blk_add_driver_data(struct request_queue *q,
return;

__blk_add_trace(bt, blk_rq_trace_sector(rq), blk_rq_bytes(rq), 0, 0,
- BLK_TA_DRV_DATA, rq->errors, len, data);
+ BLK_TA_DRV_DATA, 0, len, data);
}
EXPORT_SYMBOL_GPL(blk_add_driver_data);

--
2.11.0