| Message ID | 20170619220801.12557-4-bart.vanassche@wdc.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 06/19/2017 04:07 PM, Bart Van Assche wrote: > From: Bart Van Assche <bart.vanassche@sandisk.com> > > Several block drivers need to initialize the driver-private request > data after having called blk_get_request() and before .prep_rq_fn() > is called, e.g. when submitting a REQ_OP_SCSI_* request. Avoid that > that initialization code has to be repeated after every > blk_get_request() call by adding new callback functions to struct > request_queue and to struct blk_mq_ops. > > Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> > Cc: Christoph Hellwig <hch@lst.de> > Cc: Hannes Reinecke <hare@suse.com> > Cc: Omar Sandoval <osandov@fb.com> > --- > block/blk-core.c | 17 +++++++++++++++-- > include/linux/blk-mq.h | 2 ++ > include/linux/blkdev.h | 4 ++++ > 3 files changed, 21 insertions(+), 2 deletions(-) > > diff --git a/block/blk-core.c b/block/blk-core.c > index 93edf22009fe..0c08cf3559c9 100644 > --- a/block/blk-core.c > +++ b/block/blk-core.c > @@ -1366,12 +1366,25 @@ 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) > - return blk_mq_alloc_request(q, op, > + req = blk_mq_alloc_request(q, op, > (gfp_mask & __GFP_DIRECT_RECLAIM) ? > 0 : BLK_MQ_REQ_NOWAIT); > else > - return blk_old_get_request(q, op, gfp_mask); > + req = blk_old_get_request(q, op, gfp_mask); > + > + if (IS_ERR(req)) > + goto out; > + > + if (q->mq_ops && q->mq_ops->initialize_rq_fn) > + q->mq_ops->initialize_rq_fn(req); > + else if (!q->mq_ops && q->initialize_rq_fn) > + q->initialize_rq_fn(req); Why not fold these into the previous mq_ops-or-not check? Or put them in blk_mq_alloc_request() and blk_old_get_request() instead?
On 06/20/2017 12:07 AM, Bart Van Assche wrote: > From: Bart Van Assche <bart.vanassche@sandisk.com> > > Several block drivers need to initialize the driver-private request > data after having called blk_get_request() and before .prep_rq_fn() > is called, e.g. when submitting a REQ_OP_SCSI_* request. Avoid that > that initialization code has to be repeated after every > blk_get_request() call by adding new callback functions to struct > request_queue and to struct blk_mq_ops. > > Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> > Cc: Christoph Hellwig <hch@lst.de> > Cc: Hannes Reinecke <hare@suse.com> > Cc: Omar Sandoval <osandov@fb.com> > --- > block/blk-core.c | 17 +++++++++++++++-- > include/linux/blk-mq.h | 2 ++ > include/linux/blkdev.h | 4 ++++ > 3 files changed, 21 insertions(+), 2 deletions(-) > Thanks for doing so. I had been missing this functionality for a long time; now I can finally go ahead and convert the dasd driver :-) Reviewed-by: Hannes Reinecke <hare@suse.com> Cheers, Hannes
diff --git a/block/blk-core.c b/block/blk-core.c index 93edf22009fe..0c08cf3559c9 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1366,12 +1366,25 @@ 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) - return blk_mq_alloc_request(q, op, + req = blk_mq_alloc_request(q, op, (gfp_mask & __GFP_DIRECT_RECLAIM) ? 0 : BLK_MQ_REQ_NOWAIT); else - return blk_old_get_request(q, op, gfp_mask); + req = blk_old_get_request(q, op, gfp_mask); + + if (IS_ERR(req)) + goto out; + + if (q->mq_ops && q->mq_ops->initialize_rq_fn) + q->mq_ops->initialize_rq_fn(req); + else if (!q->mq_ops && q->initialize_rq_fn) + q->initialize_rq_fn(req); + +out: + return req; } EXPORT_SYMBOL(blk_get_request); diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index 698015526ca7..23d32ff0b462 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -144,6 +144,8 @@ struct blk_mq_ops { init_request_fn *init_request; exit_request_fn *exit_request; reinit_request_fn *reinit_request; + /* Called from inside blk_get_request() */ + void (*initialize_rq_fn)(struct request *rq); map_queues_fn *map_queues; diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index c2844c27ef65..ff0ae83235ea 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -410,8 +410,12 @@ struct request_queue { rq_timed_out_fn *rq_timed_out_fn; dma_drain_needed_fn *dma_drain_needed; lld_busy_fn *lld_busy_fn; + /* Called just after a request is allocated */ init_rq_fn *init_rq_fn; + /* Called just before a request is freed */ exit_rq_fn *exit_rq_fn; + /* Called from inside blk_get_request() */ + void (*initialize_rq_fn)(struct request *rq); const struct blk_mq_ops *mq_ops;