diff options
| -rw-r--r-- | drivers/block/ll_rw_blk.c | 56 | ||||
| -rw-r--r-- | fs/bio.c | 66 | ||||
| -rw-r--r-- | include/linux/bio.h | 2 | ||||
| -rw-r--r-- | include/linux/blkdev.h | 2 |
4 files changed, 126 insertions, 0 deletions
diff --git a/drivers/block/ll_rw_blk.c b/drivers/block/ll_rw_blk.c index f20eba2..e30a3c9 100644 --- a/drivers/block/ll_rw_blk.c +++ b/drivers/block/ll_rw_blk.c @@ -281,6 +281,7 @@ static inline void rq_init(request_queue_t *q, struct request *rq) rq->special = NULL; rq->data_len = 0; rq->data = NULL; + rq->nr_phys_segments = 0; rq->sense = NULL; rq->end_io = NULL; rq->end_io_data = NULL; @@ -2176,6 +2177,61 @@ int blk_rq_unmap_user(struct request *rq, struct bio *bio, unsigned int ulen) EXPORT_SYMBOL(blk_rq_unmap_user); +static int blk_rq_map_kern_endio(struct bio *bio, unsigned int bytes_done, + int error) +{ + if (bio->bi_size) + return 1; + + bio_put(bio); + return 0; +} + +/** + * blk_rq_map_kern - map kernel data to a request, for REQ_BLOCK_PC usage + * @q: request queue where request should be inserted + * @rw: READ or WRITE data + * @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) +{ + 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); + + bio = bio_map_kern(q, kbuf, len, gfp_mask); + if (!IS_ERR(bio)) { + if (rw) + bio->bi_rw |= (1 << BIO_RW); + bio->bi_end_io = blk_rq_map_kern_endio; + + rq->bio = rq->biotail = bio; + blk_rq_bio_prep(q, rq, bio); + + rq->buffer = rq->data = NULL; + rq->data_len = len; + return rq; + } + + /* + * bio is the err-ptr + */ + blk_put_request(rq); + return (struct request *) bio; +} + +EXPORT_SYMBOL(blk_rq_map_kern); + /** * blk_execute_rq - insert a request into queue for execution * @q: queue to insert the request in @@ -701,6 +701,71 @@ void bio_unmap_user(struct bio *bio) bio_put(bio); } +static struct bio *__bio_map_kern(request_queue_t *q, void *data, + unsigned int len, unsigned int gfp_mask) +{ + unsigned long kaddr = (unsigned long)data; + unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; + unsigned long start = kaddr >> PAGE_SHIFT; + const int nr_pages = end - start; + int offset, i; + struct bio *bio; + + bio = bio_alloc(gfp_mask, nr_pages); + if (!bio) + return ERR_PTR(-ENOMEM); + + offset = offset_in_page(kaddr); + for (i = 0; i < nr_pages; i++) { + unsigned int bytes = PAGE_SIZE - offset; + + if (len <= 0) + break; + + if (bytes > len) + bytes = len; + + if (__bio_add_page(q, bio, virt_to_page(data), bytes, + offset) < bytes) + break; + + data += bytes; + len -= bytes; + offset = 0; + } + + return bio; +} + +/** + * bio_map_kern - map kernel address into bio + * @q: the request_queue_t for the bio + * @data: pointer to buffer to map + * @len: length in bytes + * @gfp_mask: allocation flags for bio allocation + * + * Map the kernel address into a bio suitable for io to a block + * device. Returns an error pointer in case of error. + */ +struct bio *bio_map_kern(request_queue_t *q, void *data, unsigned int len, + unsigned int gfp_mask) +{ + struct bio *bio; + + bio = __bio_map_kern(q, data, len, gfp_mask); + if (IS_ERR(bio)) + return bio; + + if (bio->bi_size == len) + return bio; + + /* + * Don't support partial mappings. + */ + bio_put(bio); + return ERR_PTR(-EINVAL); +} + /* * bio_set_pages_dirty() and bio_check_pages_dirty() are support functions * for performing direct-IO in BIOs. @@ -1088,6 +1153,7 @@ EXPORT_SYMBOL(bio_add_page); EXPORT_SYMBOL(bio_get_nr_vecs); EXPORT_SYMBOL(bio_map_user); EXPORT_SYMBOL(bio_unmap_user); +EXPORT_SYMBOL(bio_map_kern); EXPORT_SYMBOL(bio_pair_release); EXPORT_SYMBOL(bio_split); EXPORT_SYMBOL(bio_split_pool); diff --git a/include/linux/bio.h b/include/linux/bio.h index 0380227..1dd2bc2 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -282,6 +282,8 @@ extern int bio_get_nr_vecs(struct block_device *); extern struct bio *bio_map_user(struct request_queue *, struct block_device *, unsigned long, unsigned int, int); extern void bio_unmap_user(struct bio *); +extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int, + unsigned int); extern void bio_set_pages_dirty(struct bio *bio); extern void bio_check_pages_dirty(struct bio *bio); extern struct bio *bio_copy_user(struct request_queue *, unsigned long, unsigned int, int); diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 4a99b76..67339bc 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -560,6 +560,8 @@ extern void blk_run_queue(request_queue_t *); extern void blk_queue_activity_fn(request_queue_t *, activity_fn *, void *); extern struct request *blk_rq_map_user(request_queue_t *, int, void __user *, unsigned int); extern int blk_rq_unmap_user(struct request *, struct bio *, unsigned int); +extern struct request *blk_rq_map_kern(request_queue_t *, int, void *, + unsigned int, unsigned int); extern int blk_execute_rq(request_queue_t *, struct gendisk *, struct request *); static inline request_queue_t *bdev_get_queue(struct block_device *bdev) |