Re: [PATCH linux-2.6-block:master 02/10] blk: separate out bio init part from __make_request

Tejun Heo
2005-07-26T15:49:27Z

02_blk_implement-init_request_from_bio.patch

Separate out bio initialization part from __make_request. It
will be used by the following blk_ordered_reimpl.

Signed-off-by: Tejun Heo <htejun@gmail.com>

ll_rw_blk.c | 59 ++++++++++++++++++++++++++++++++---------------------------
1 files changed, 32 insertions(+), 27 deletions(-)

Index: blk-fixes/drivers/block/ll_rw_blk.c
===================================================================
--- blk-fixes.orig/drivers/block/ll_rw_blk.c 2005-07-27 00:44:50.000000000 +0900
+++ blk-fixes/drivers/block/ll_rw_blk.c 2005-07-27 00:44:50.000000000 +0900
@@ -36,6 +36,8 @@

static void blk_unplug_work(void *data);
static void blk_unplug_timeout(unsigned long data);
+static void init_request_from_bio(struct request *req, struct bio *bio);
+static int __make_request(request_queue_t *q, struct bio *bio);

/*
* For the allocated request tables
@@ -1655,8 +1657,6 @@ static int blk_init_free_list(request_qu
return 0;
}

-static int __make_request(request_queue_t *, struct bio *);
-
request_queue_t *blk_alloc_queue(int gfp_mask)
{
request_queue_t *q = kmem_cache_alloc(requestq_cachep, gfp_mask);
@@ -2555,6 +2555,35 @@ void blk_attempt_remerge(request_queue_t

EXPORT_SYMBOL(blk_attempt_remerge);

+static void init_request_from_bio(struct request *req, struct bio *bio)
+{
+ req->flags |= REQ_CMD;
+
+ /*
+ * inherit FAILFAST from bio (for read-ahead, and explicit FAILFAST)
+ */
+ if (bio_rw_ahead(bio) || bio_failfast(bio))
+ req->flags |= REQ_FAILFAST;
+
+ /*
+ * REQ_BARRIER implies no merging, but lets make it explicit
+ */
+ if (unlikely(bio_barrier(bio)))
+ req->flags |= (REQ_HARDBARRIER | REQ_NOMERGE);
+
+ req->errors = 0;
+ req->hard_sector = req->sector = bio->bi_sector;
+ req->hard_nr_sectors = req->nr_sectors = bio_sectors(bio);
+ req->current_nr_sectors = req->hard_cur_sectors = bio_cur_sectors(bio);
+ req->nr_phys_segments = bio_phys_segments(req->q, bio);
+ req->nr_hw_segments = bio_hw_segments(req->q, bio);
+ req->buffer = bio_data(bio); /* see ->buffer comment above */
+ req->waiting = NULL;
+ req->bio = req->biotail = bio;
+ req->rq_disk = bio->bi_bdev->bd_disk;
+ req->start_time = jiffies;
+}
+
/*
* Non-locking blk_attempt_remerge variant.
*/
@@ -2678,31 +2707,7 @@ get_rq:
goto again;
}

- req->flags |= REQ_CMD;
-
- /*
- * inherit FAILFAST from bio (for read-ahead, and explicit FAILFAST)
- */
- if (bio_rw_ahead(bio) || bio_failfast(bio))
- req->flags |= REQ_FAILFAST;
-
- /*
- * REQ_BARRIER implies no merging, but lets make it explicit
- */
- if (barrier)
- req->flags |= (REQ_HARDBARRIER | REQ_NOMERGE);
-
- req->errors = 0;
- req->hard_sector = req->sector = sector;
- req->hard_nr_sectors = req->nr_sectors = nr_sectors;
- req->current_nr_sectors = req->hard_cur_sectors = cur_nr_sectors;
- req->nr_phys_segments = bio_phys_segments(q, bio);
- req->nr_hw_segments = bio_hw_segments(q, bio);
- req->buffer = bio_data(bio); /* see ->buffer comment above */
- req->waiting = NULL;
- req->bio = req->biotail = bio;
- req->rq_disk = bio->bi_bdev->bd_disk;
- req->start_time = jiffies;
+ init_request_from_bio(req, bio);

add_request(q, req);