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author | Christoph Hellwig <hch@lst.de> | 2015-01-18 16:16:29 +0100 |
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committer | Jens Axboe <axboe@fb.com> | 2015-02-05 09:30:37 -0700 |
commit | ddad8dd0a162fde61646a627a3017c258601dc8a (patch) | |
tree | 62a0c931c0efb7cd86457e1908ceb1655997c595 /block/blk-map.c | |
parent | 42d2683a2704ef4bbbb07fd0b9486ab312dd8c56 (diff) | |
download | linux-stable-ddad8dd0a162fde61646a627a3017c258601dc8a.tar.gz linux-stable-ddad8dd0a162fde61646a627a3017c258601dc8a.tar.bz2 linux-stable-ddad8dd0a162fde61646a627a3017c258601dc8a.zip |
block: use blk_rq_map_user_iov to implement blk_rq_map_user
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'block/blk-map.c')
-rw-r--r-- | block/blk-map.c | 137 |
1 files changed, 13 insertions, 124 deletions
diff --git a/block/blk-map.c b/block/blk-map.c index f890d4345b0c..152a5fe5d85e 100644 --- a/block/blk-map.c +++ b/block/blk-map.c @@ -39,130 +39,6 @@ static int __blk_rq_unmap_user(struct bio *bio) return ret; } -static int __blk_rq_map_user(struct request_queue *q, struct request *rq, - struct rq_map_data *map_data, void __user *ubuf, - unsigned int len, gfp_t gfp_mask) -{ - unsigned long uaddr; - struct bio *bio, *orig_bio; - int reading, ret; - - reading = rq_data_dir(rq) == READ; - - /* - * if alignment requirement is satisfied, map in user pages for - * direct dma. else, set up kernel bounce buffers - */ - uaddr = (unsigned long) ubuf; - if (blk_rq_aligned(q, uaddr, len) && !map_data) - bio = bio_map_user(q, NULL, uaddr, len, reading, gfp_mask); - else - bio = bio_copy_user(q, map_data, uaddr, len, reading, gfp_mask); - - if (IS_ERR(bio)) - return PTR_ERR(bio); - - if (map_data && map_data->null_mapped) - bio->bi_flags |= (1 << BIO_NULL_MAPPED); - - orig_bio = bio; - blk_queue_bounce(q, &bio); - - /* - * We link the bounce buffer in and could have to traverse it - * later so we have to get a ref to prevent it from being freed - */ - bio_get(bio); - - ret = blk_rq_append_bio(q, rq, bio); - if (!ret) - return bio->bi_iter.bi_size; - - /* if it was boucned we must call the end io function */ - bio_endio(bio, 0); - __blk_rq_unmap_user(orig_bio); - bio_put(bio); - return ret; -} - -/** - * blk_rq_map_user - map user data to a request, for REQ_TYPE_BLOCK_PC usage - * @q: request queue where request should be inserted - * @rq: request structure to fill - * @map_data: pointer to the rq_map_data holding pages (if necessary) - * @ubuf: the user buffer - * @len: length of user data - * @gfp_mask: memory allocation flags - * - * Description: - * Data will be mapped directly for zero copy I/O, if possible. Otherwise - * a kernel bounce buffer is used. - * - * A matching blk_rq_unmap_user() must be issued at the end of I/O, while - * still in process context. - * - * Note: The mapped bio may need to be bounced through blk_queue_bounce() - * before being submitted to the device, as pages mapped may be out of - * reach. It's the callers responsibility to make sure this happens. The - * original bio must be passed back in to blk_rq_unmap_user() for proper - * unmapping. - */ -int blk_rq_map_user(struct request_queue *q, struct request *rq, - struct rq_map_data *map_data, void __user *ubuf, - unsigned long len, gfp_t gfp_mask) -{ - unsigned long bytes_read = 0; - struct bio *bio = NULL; - int ret; - - if (len > (queue_max_hw_sectors(q) << 9)) - return -EINVAL; - if (!len) - return -EINVAL; - - if (!ubuf && (!map_data || !map_data->null_mapped)) - return -EINVAL; - - while (bytes_read != len) { - unsigned long map_len, end, start; - - map_len = min_t(unsigned long, len - bytes_read, BIO_MAX_SIZE); - end = ((unsigned long)ubuf + map_len + PAGE_SIZE - 1) - >> PAGE_SHIFT; - start = (unsigned long)ubuf >> PAGE_SHIFT; - - /* - * A bad offset could cause us to require BIO_MAX_PAGES + 1 - * pages. If this happens we just lower the requested - * mapping len by a page so that we can fit - */ - if (end - start > BIO_MAX_PAGES) - map_len -= PAGE_SIZE; - - ret = __blk_rq_map_user(q, rq, map_data, ubuf, map_len, - gfp_mask); - if (ret < 0) - goto unmap_rq; - if (!bio) - bio = rq->bio; - bytes_read += ret; - ubuf += ret; - - if (map_data) - map_data->offset += ret; - } - - if (!bio_flagged(bio, BIO_USER_MAPPED)) - rq->cmd_flags |= REQ_COPY_USER; - - return 0; -unmap_rq: - blk_rq_unmap_user(bio); - rq->bio = NULL; - return ret; -} -EXPORT_SYMBOL(blk_rq_map_user); - /** * blk_rq_map_user_iov - map user data to a request, for REQ_TYPE_BLOCK_PC usage * @q: request queue where request should be inserted @@ -241,6 +117,19 @@ int blk_rq_map_user_iov(struct request_queue *q, struct request *rq, } EXPORT_SYMBOL(blk_rq_map_user_iov); +int blk_rq_map_user(struct request_queue *q, struct request *rq, + struct rq_map_data *map_data, void __user *ubuf, + unsigned long len, gfp_t gfp_mask) +{ + struct sg_iovec iov; + + iov.iov_base = (void __user *)ubuf; + iov.iov_len = len; + + return blk_rq_map_user_iov(q, rq, map_data, &iov, 1, len, gfp_mask); +} +EXPORT_SYMBOL(blk_rq_map_user); + /** * blk_rq_unmap_user - unmap a request with user data * @bio: start of bio list |