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author | Boaz Harrosh <bharrosh@panasas.com> | 2009-05-17 17:57:15 +0200 |
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committer | Jens Axboe <jens.axboe@oracle.com> | 2009-05-19 12:14:56 +0200 |
commit | 79eb63e9e5875b84341a3a05f8e6ae9cdb4bb6f6 (patch) | |
tree | bdadc2037c1d0f24c6c73b71ae82fdd7b907e610 | |
parent | libosd: Use new blk_rq_map_kern (diff) | |
download | linux-79eb63e9e5875b84341a3a05f8e6ae9cdb4bb6f6.tar.xz linux-79eb63e9e5875b84341a3a05f8e6ae9cdb4bb6f6.zip |
block: Add blk_make_request(), takes bio, returns a request
New block API:
given a struct bio allocates a new request. This is the parallel of
generic_make_request for BLOCK_PC commands users.
The passed bio may be a chained-bio. The bio is bounced if needed
inside the call to this member.
This is in the effort of un-exporting blk_rq_append_bio().
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
CC: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
-rw-r--r-- | block/blk-core.c | 45 | ||||
-rw-r--r-- | include/linux/blkdev.h | 2 |
2 files changed, 47 insertions, 0 deletions
diff --git a/block/blk-core.c b/block/blk-core.c index e3f7e6a3a095..bec1d69952d0 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -891,6 +891,51 @@ struct request *blk_get_request(struct request_queue *q, int rw, gfp_t gfp_mask) EXPORT_SYMBOL(blk_get_request); /** + * blk_make_request - given a bio, allocate a corresponding struct request. + * + * @bio: The bio describing the memory mappings that will be submitted for IO. + * It may be a chained-bio properly constructed by block/bio layer. + * + * blk_make_request is the parallel of generic_make_request for BLOCK_PC + * type commands. Where the struct request needs to be farther initialized by + * the caller. It is passed a &struct bio, which describes the memory info of + * the I/O transfer. + * + * The caller of blk_make_request must make sure that bi_io_vec + * are set to describe the memory buffers. That bio_data_dir() will return + * the needed direction of the request. (And all bio's in the passed bio-chain + * are properly set accordingly) + * + * If called under none-sleepable conditions, mapped bio buffers must not + * need bouncing, by calling the appropriate masked or flagged allocator, + * suitable for the target device. Otherwise the call to blk_queue_bounce will + * BUG. + */ +struct request *blk_make_request(struct request_queue *q, struct bio *bio, + gfp_t gfp_mask) +{ + struct request *rq = blk_get_request(q, bio_data_dir(bio), gfp_mask); + + if (unlikely(!rq)) + return ERR_PTR(-ENOMEM); + + for_each_bio(bio) { + struct bio *bounce_bio = bio; + int ret; + + blk_queue_bounce(q, &bounce_bio); + ret = blk_rq_append_bio(q, rq, bounce_bio); + if (unlikely(ret)) { + blk_put_request(rq); + return ERR_PTR(ret); + } + } + + return rq; +} +EXPORT_SYMBOL(blk_make_request); + +/** * blk_requeue_request - put a request back on queue * @q: request queue where request should be inserted * @rq: request to be inserted diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index f9d60a78c08a..88a83e112c95 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -740,6 +740,8 @@ extern void blk_rq_init(struct request_queue *q, struct request *rq); extern void blk_put_request(struct request *); extern void __blk_put_request(struct request_queue *, struct request *); extern struct request *blk_get_request(struct request_queue *, int, gfp_t); +extern struct request *blk_make_request(struct request_queue *, struct bio *, + gfp_t); extern void blk_insert_request(struct request_queue *, struct request *, int, void *); extern void blk_requeue_request(struct request_queue *, struct request *); extern int blk_rq_check_limits(struct request_queue *q, struct request *rq); |