[PATCH] Cleanup blk_rq_map_* interfaces
Change the blk_rq_map_user() and blk_rq_map_kern() interface to require
a previously allocated request to be passed in. This is both more efficient
for multiple iterations of mapping data to the same request, and it is also
a much nicer API.
Signed-off-by: Jens Axboe <axboe@suse.de>
diff --git a/drivers/block/ll_rw_blk.c b/drivers/block/ll_rw_blk.c
index 1471aca..42c4f36 100644
--- a/drivers/block/ll_rw_blk.c
+++ b/drivers/block/ll_rw_blk.c
@@ -2107,21 +2107,19 @@
* original bio must be passed back in to blk_rq_unmap_user() for proper
* unmapping.
*/
-struct request *blk_rq_map_user(request_queue_t *q, int rw, void __user *ubuf,
- unsigned int len)
+int blk_rq_map_user(request_queue_t *q, struct request *rq, void __user *ubuf,
+ unsigned int len)
{
unsigned long uaddr;
- struct request *rq;
struct bio *bio;
+ int reading;
if (len > (q->max_sectors << 9))
- return ERR_PTR(-EINVAL);
- if ((!len && ubuf) || (len && !ubuf))
- return ERR_PTR(-EINVAL);
+ return -EINVAL;
+ if (!len || !ubuf)
+ return -EINVAL;
- rq = blk_get_request(q, rw, __GFP_WAIT);
- if (!rq)
- return ERR_PTR(-ENOMEM);
+ reading = rq_data_dir(rq) == READ;
/*
* if alignment requirement is satisfied, map in user pages for
@@ -2129,9 +2127,9 @@
*/
uaddr = (unsigned long) ubuf;
if (!(uaddr & queue_dma_alignment(q)) && !(len & queue_dma_alignment(q)))
- bio = bio_map_user(q, NULL, uaddr, len, rw == READ);
+ bio = bio_map_user(q, NULL, uaddr, len, reading);
else
- bio = bio_copy_user(q, uaddr, len, rw == READ);
+ bio = bio_copy_user(q, uaddr, len, reading);
if (!IS_ERR(bio)) {
rq->bio = rq->biotail = bio;
@@ -2139,14 +2137,13 @@
rq->buffer = rq->data = NULL;
rq->data_len = len;
- return rq;
+ return 0;
}
/*
* bio is the err-ptr
*/
- blk_put_request(rq);
- return (struct request *) bio;
+ return PTR_ERR(bio);
}
EXPORT_SYMBOL(blk_rq_map_user);
@@ -2160,7 +2157,7 @@
* Description:
* Unmap a request previously mapped by blk_rq_map_user().
*/
-int blk_rq_unmap_user(struct request *rq, struct bio *bio, unsigned int ulen)
+int blk_rq_unmap_user(struct bio *bio, unsigned int ulen)
{
int ret = 0;
@@ -2171,8 +2168,7 @@
ret = bio_uncopy_user(bio);
}
- blk_put_request(rq);
- return ret;
+ return 0;
}
EXPORT_SYMBOL(blk_rq_unmap_user);
@@ -2184,39 +2180,29 @@
* @kbuf: the kernel buffer
* @len: length of user data
*/
-struct request *blk_rq_map_kern(request_queue_t *q, int rw, void *kbuf,
- unsigned int len, unsigned int gfp_mask)
+int blk_rq_map_kern(request_queue_t *q, struct request *rq, void *kbuf,
+ unsigned int len, unsigned int gfp_mask)
{
- struct request *rq;
struct bio *bio;
if (len > (q->max_sectors << 9))
- return ERR_PTR(-EINVAL);
- if ((!len && kbuf) || (len && !kbuf))
- return ERR_PTR(-EINVAL);
-
- rq = blk_get_request(q, rw, gfp_mask);
- if (!rq)
- return ERR_PTR(-ENOMEM);
+ return -EINVAL;
+ if (!len || !kbuf)
+ return -EINVAL;
bio = bio_map_kern(q, kbuf, len, gfp_mask);
- if (!IS_ERR(bio)) {
- if (rw)
- bio->bi_rw |= (1 << BIO_RW);
+ if (IS_ERR(bio))
+ return PTR_ERR(bio);
- rq->bio = rq->biotail = bio;
- blk_rq_bio_prep(q, rq, bio);
+ if (rq_data_dir(rq) == WRITE)
+ bio->bi_rw |= (1 << BIO_RW);
- rq->buffer = rq->data = NULL;
- rq->data_len = len;
- return rq;
- }
+ rq->bio = rq->biotail = bio;
+ blk_rq_bio_prep(q, rq, bio);
- /*
- * bio is the err-ptr
- */
- blk_put_request(rq);
- return (struct request *) bio;
+ rq->buffer = rq->data = NULL;
+ rq->data_len = len;
+ return 0;
}
EXPORT_SYMBOL(blk_rq_map_kern);