On Fri, 25 Apr 2008 11:31:41 +0200 Jens Axboe <jens.axboe@xxxxxxxxxx> wrote: > On Fri, Apr 25 2008, FUJITA Tomonori wrote: > > On Fri, 25 Apr 2008 11:22:04 +0200 > > Jens Axboe <jens.axboe@xxxxxxxxxx> wrote: > > > > > On Fri, Apr 25 2008, FUJITA Tomonori wrote: > > > > On Thu, 24 Apr 2008 12:49:30 +0200 > > > > Jens Axboe <jens.axboe@xxxxxxxxxx> wrote: > > > > > > > > > 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. > > > > > > > > Sorry, can you be more specific? > > > > > > > > Only cfq uses set_request for now. cfq_set_request uses rq->cmd_flags > > > > and stores information at rq->elevator_private and > > > > rq->elevator_private2. > > > > > > > > The patch does memset() the request structure and sets up > > > > rq->cmd_flags, and then elv_set_request. Doesn't it work? > > > > > > Sorry, with the moved rq_init() it should work, didn't look closely > > > enough. > > > > No problem. > > > > So are you ok with the patch? If so, I'll re-send it with a proper > > description and the signed-off. > > Please do - I actually already merged it, but do resend with a full > description and signed-off etc. I just stole your description and added my signed-off. Will you merge the large command support for 2.6.26? Or only this clean-up patch? = From: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx> Subject: [PATCH] block: make rq_init() do a full memset() This requires moving rq_init() from get_request() to blk_alloc_request(). The upside is that we can now require an rq_init() from any path that wishes to hand the request to the block layer. rq_init() will be exported for the code that uses struct request without blk_get_request. This is a preparation for large command support, which needs to initialize struct request in a proper way (that is, just doing a memset() will not work). Signed-off-by: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx> Signed-off-by: Jens Axboe <jens.axboe@xxxxxxxxxx> --- block/blk-barrier.c | 7 +------ block/blk-core.c | 30 ++++-------------------------- 2 files changed, 5 insertions(+), 32 deletions(-) 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; -- 1.5.4.2 -- 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
