Since .initialize_rq_fn() is called from inside blk_get_request() that function is only called for pass-through requests but not for filesystem requests. There is agreement in the SCSI community that the jiffies_at_alloc and retries members of struct scsi_cmnd should be initialized at request allocation time instead of when preparing a request. This will allow to preserve the value of these members when requeuing a request. Since the block layer does not yet allow block drivers to initialize filesystem requests without overriding request_queue.make_request_fn, move the .initialize_rq_fn() calls from blk_get_request() into blk_mq_rq_ctx_init() and blk_rq_init().
See also https://www.spinics.net/lists/linux-scsi/msg108934.html. Signed-off-by: Bart Van Assche <bart.vanass...@wdc.com> Cc: Christoph Hellwig <h...@lst.de> Cc: Martin K. Petersen <martin.peter...@oracle.com> Cc: Hannes Reinecke <h...@suse.com> --- block/blk-core.c | 20 +++++++------------- block/blk-mq.c | 4 ++++ 2 files changed, 11 insertions(+), 13 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index 78a46794053e..463aa0ee36ce 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -126,6 +126,9 @@ void blk_rq_init(struct request_queue *q, struct request *rq) rq->start_time = jiffies; set_start_time_ns(rq); rq->part = NULL; + + if (q && q->initialize_rq_fn) + q->initialize_rq_fn(rq); } EXPORT_SYMBOL(blk_rq_init); @@ -1420,21 +1423,12 @@ static struct request *blk_old_get_request(struct request_queue *q, struct request *blk_get_request(struct request_queue *q, unsigned int op, gfp_t gfp_mask) { - struct request *req; - - if (q->mq_ops) { - req = blk_mq_alloc_request(q, op, + if (q->mq_ops) + return blk_mq_alloc_request(q, op, (gfp_mask & __GFP_DIRECT_RECLAIM) ? 0 : BLK_MQ_REQ_NOWAIT); - if (!IS_ERR(req) && q->mq_ops->initialize_rq_fn) - q->mq_ops->initialize_rq_fn(req); - } else { - req = blk_old_get_request(q, op, gfp_mask); - if (!IS_ERR(req) && q->initialize_rq_fn) - q->initialize_rq_fn(req); - } - - return req; + else + return blk_old_get_request(q, op, gfp_mask); } EXPORT_SYMBOL(blk_get_request); diff --git a/block/blk-mq.c b/block/blk-mq.c index 21f2cff217ce..fdb33f8a2860 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -273,6 +273,7 @@ EXPORT_SYMBOL(blk_mq_can_queue); static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data, unsigned int tag, unsigned int op) { + struct request_queue *q = data->q; struct blk_mq_tags *tags = blk_mq_tags_from_data(data); struct request *rq = tags->static_rqs[tag]; @@ -325,6 +326,9 @@ static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data, rq->end_io_data = NULL; rq->next_rq = NULL; + if (q->mq_ops->initialize_rq_fn) + q->mq_ops->initialize_rq_fn(rq); + data->ctx->rq_dispatched[op_is_sync(op)]++; return rq; } -- 2.14.1
