On Thu, Apr 24 2008, FUJITA Tomonori wrote: > On Thu, 24 Apr 2008 13:31:21 +0900 > FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx> wrote: > > > On Wed, 23 Apr 2008 17:50:42 +0300 > > Boaz Harrosh <bharrosh@xxxxxxxxxxx> wrote: > > > > > > > > The support for large commands was dropped from the for-2.6.26 branch > > > and will probably not get accepted into next kernel. > > > > > > I have tried to take all comments from Jens and Bart. and incorporate > > > it into a new patchset. This is basically Tomo's patchset but with > > > proposed changes. > > > > Have you seen the patchset to remove request on the stack? > > > > http://marc.info/?l=linux-ide&m=120882410712466&w=2 > > > > > > > They are based on current linux-block/master. They will probably conflict with > > > latest patch sent by Tomo for the blk_get_request(). Once those patches > > > get accepted at some git tree, (Where will that be?), I will rebase these > > > on top of them. Please CC me of any progress. > > > > > > [PATCH 1/5] block: no need to initialize rq->cmd > > > This is 2 of Tomo's patches squashed together as they are > > > small and do the same. Tomo is this OK? > > > > > > [PATCH 2/5] block: replace sizeof(rq->cmd) with BLK_MAX_CDB > > > Tomos patch rebased to here > > > > > > [PATCH 3/5] block: Export rq_init, rename to blk_init_rq > > > [PATCH 4/5] block: Use new blk_init_rq > > > These patches are basically what Jens and Bart has suggested, that with > > > a small code change to blk-core.c we can memset at rq_init() and only set > > > none zero members. We can also export that initializer and use it all over > > > the ide tree where ever requests don't come from a request queue. (OK also > > > at scsi_error.c) > > > > +void blk_init_rq(struct request_queue *q, struct request *rq, int cmd_flags) > > > > Hmm, would it be better to modify the block layer to let rq_init just > > memset() the request structure? > > I think, if we move rq_init to blk_alloc_request from get_request, > rq_init can just memset() the structure. > > Then we can export rq_init and rq_init works for everyone. Wont work, see the io scheduler set_request() functions. > > > diff --git a/block/blk-barrier.c b/block/blk-barrier.c > index 55c5f1f..722140a 100644 > --- a/block/blk-barrier.c > +++ b/block/blk-barrier.c > @@ -143,10 +143,8 @@ static void queue_flush(struct request_queue *q, unsigned which) > end_io = post_flush_end_io; > } > > - rq->cmd_flags = REQ_HARDBARRIER; > rq_init(q, rq); > - rq->elevator_private = NULL; > - rq->elevator_private2 = NULL; > + rq->cmd_flags = REQ_HARDBARRIER; > rq->rq_disk = q->bar_rq.rq_disk; > rq->end_io = end_io; > q->prepare_flush_fn(q, rq); > @@ -167,14 +165,11 @@ static inline struct request *start_ordered(struct request_queue *q, > blkdev_dequeue_request(rq); > q->orig_bar_rq = rq; > rq = &q->bar_rq; > - rq->cmd_flags = 0; > rq_init(q, rq); > if (bio_data_dir(q->orig_bar_rq->bio) == WRITE) > rq->cmd_flags |= REQ_RW; > if (q->ordered & QUEUE_ORDERED_FUA) > rq->cmd_flags |= REQ_FUA; > - rq->elevator_private = NULL; > - rq->elevator_private2 = NULL; > init_request_from_bio(rq, q->orig_bar_rq->bio); > rq->end_io = bar_end_io; > > diff --git a/block/blk-core.c b/block/blk-core.c > index 2a438a9..e447799 100644 > --- a/block/blk-core.c > +++ b/block/blk-core.c > @@ -107,40 +107,18 @@ struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev) > } > EXPORT_SYMBOL(blk_get_backing_dev_info); > > -/* > - * We can't just memset() the structure, since the allocation path > - * already stored some information in the request. > - */ > void rq_init(struct request_queue *q, struct request *rq) > { > + memset(rq, 0, sizeof(*rq)); > + > INIT_LIST_HEAD(&rq->queuelist); > INIT_LIST_HEAD(&rq->donelist); > rq->q = q; > rq->sector = rq->hard_sector = (sector_t) -1; > - rq->nr_sectors = rq->hard_nr_sectors = 0; > - rq->current_nr_sectors = rq->hard_cur_sectors = 0; > - rq->bio = rq->biotail = NULL; > INIT_HLIST_NODE(&rq->hash); > RB_CLEAR_NODE(&rq->rb_node); > - rq->rq_disk = NULL; > - rq->nr_phys_segments = 0; > - rq->nr_hw_segments = 0; > - rq->ioprio = 0; > - rq->special = NULL; > - rq->buffer = NULL; > rq->tag = -1; > - rq->errors = 0; > rq->ref_count = 1; > - rq->cmd_len = 0; > - memset(rq->cmd, 0, sizeof(rq->cmd)); > - rq->data_len = 0; > - rq->extra_len = 0; > - rq->sense_len = 0; > - rq->data = NULL; > - rq->sense = NULL; > - rq->end_io = NULL; > - rq->end_io_data = NULL; > - rq->next_rq = NULL; > } > > static void req_bio_endio(struct request *rq, struct bio *bio, > @@ -607,6 +585,8 @@ blk_alloc_request(struct request_queue *q, int rw, int priv, gfp_t gfp_mask) > if (!rq) > return NULL; > > + rq_init(q, rq); > + > /* > * first three bits are identical in rq->cmd_flags and bio->bi_rw, > * see bio.h and blkdev.h > @@ -789,8 +769,6 @@ rq_starved: > if (ioc_batching(q, ioc)) > ioc->nr_batch_requests--; > > - rq_init(q, rq); > - > blk_add_trace_generic(q, bio, rw, BLK_TA_GETRQ); > out: > return rq; -- Jens Axboe -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
