/** * 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 * @rq: request to map data to * @map_data: pointer to the rq_map_data holding pages (if necessary) * @iter: iovec iterator * @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_iov(struct request_queue *q, struct request *rq, struct rq_map_data *map_data, const struct iov_iter *iter, gfp_t gfp_mask) { bool copy = false; unsigned long align = q->dma_pad_mask | queue_dma_alignment(q); struct bio *bio = NULL; struct iov_iter i; int ret; if (map_data) copy = true; else if (iov_iter_alignment(iter) & align) copy = true; else if (queue_virt_boundary(q)) copy = queue_virt_boundary(q) & iov_iter_gap_alignment(iter); i = *iter; do { ret =__blk_rq_map_user_iov(rq, map_data, &i, gfp_mask, copy); if (ret) goto unmap_rq; if (!bio) bio = rq->bio; } while (iov_iter_count(&i)); 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 -EINVAL; }
/** * 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 * @rq: request to map data to * @map_data: pointer to the rq_map_data holding pages (if necessary) * @iov: pointer to the iovec * @iov_count: number of elements in the iovec * @len: I/O byte count * @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_iov(struct request_queue *q, struct request *rq, struct rq_map_data *map_data, struct sg_iovec *iov, int iov_count, unsigned int len, gfp_t gfp_mask) { struct bio *bio; int i, read = rq_data_dir(rq) == READ; int unaligned = 0; if (!iov || iov_count <= 0) return -EINVAL; for (i = 0; i < iov_count; i++) { unsigned long uaddr = (unsigned long)iov[i].iov_base; if (!iov[i].iov_len) return -EINVAL; /* * Keep going so we check length of all segments */ if (uaddr & queue_dma_alignment(q)) unaligned = 1; } if (unaligned || (q->dma_pad_mask & len) || map_data) bio = bio_copy_user_iov(q, map_data, iov, iov_count, read, gfp_mask); else bio = bio_map_user_iov(q, NULL, iov, iov_count, read, gfp_mask); if (IS_ERR(bio)) return PTR_ERR(bio); if (bio->bi_size != len) { /* * Grab an extra reference to this bio, as bio_unmap_user() * expects to be able to drop it twice as it happens on the * normal IO completion path */ bio_get(bio); bio_endio(bio, 0); __blk_rq_unmap_user(bio); return -EINVAL; } if (!bio_flagged(bio, BIO_USER_MAPPED)) rq->cmd_flags |= REQ_COPY_USER; blk_queue_bounce(q, &bio); bio_get(bio); blk_rq_bio_prep(q, rq, bio); rq->buffer = NULL; return 0; }
/** * blk_rq_map_user_iov - map user data to a request, for REQ_BLOCK_PC usage * @q: request queue where request should be inserted * @rq: request to map data to * @iov: pointer to the iovec * @iov_count: number of elements in the iovec * @len: I/O byte count * * Description: * Data will be mapped directly for zero copy io, if possible. Otherwise * a kernel bounce buffer is used. * * A matching blk_rq_unmap_user() must be issued at the end of io, 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_iov(struct request_queue *q, struct request *rq, struct sg_iovec *iov, int iov_count, unsigned int len) { struct bio *bio; int i, read = rq_data_dir(rq) == READ; int unaligned = 0; if (!iov || iov_count <= 0) return -EINVAL; for (i = 0; i < iov_count; i++) { unsigned long uaddr = (unsigned long)iov[i].iov_base; if (uaddr & queue_dma_alignment(q)) { unaligned = 1; break; } if (!iov[i].iov_len) return -EINVAL; } if (unaligned || (q->dma_pad_mask & len)) bio = bio_copy_user_iov(q, iov, iov_count, read); else bio = bio_map_user_iov(q, NULL, iov, iov_count, read); if (IS_ERR(bio)) return PTR_ERR(bio); if (bio->bi_size != len) { bio_endio(bio, 0); bio_unmap_user(bio); return -EINVAL; } if (!bio_flagged(bio, BIO_USER_MAPPED)) rq->cmd_flags |= REQ_COPY_USER; blk_queue_bounce(q, &bio); bio_get(bio); blk_rq_bio_prep(q, rq, bio); rq->buffer = rq->data = NULL; return 0; }
static int __blk_rq_map_user(struct request_queue *q, struct request *rq, void __user *ubuf, unsigned int len) { unsigned long uaddr; unsigned int alignment; 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; alignment = queue_dma_alignment(q) | q->dma_pad_mask; if (!(uaddr & alignment) && !(len & alignment)) bio = bio_map_user(q, NULL, uaddr, len, reading); else bio = bio_copy_user(q, uaddr, len, reading); if (IS_ERR(bio)) return PTR_ERR(bio); 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_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_kern - map kernel data to a request, for REQ_BLOCK_PC usage * @q: request queue where request should be inserted * @rq: request to fill * @kbuf: the kernel buffer * @len: length of user data * @gfp_mask: memory allocation flags * * Description: * Data will be mapped directly if possible. Otherwise a bounce * buffer is used. */ int blk_rq_map_kern(struct request_queue *q, struct request *rq, void *kbuf, unsigned int len, gfp_t gfp_mask) { unsigned long kaddr; unsigned int alignment; int reading = rq_data_dir(rq) == READ; int do_copy = 0; struct bio *bio; if (len > (q->max_hw_sectors << 9)) return -EINVAL; if (!len || !kbuf) return -EINVAL; kaddr = (unsigned long)kbuf; alignment = queue_dma_alignment(q) | q->dma_pad_mask; do_copy = ((kaddr & alignment) || (len & alignment) || object_is_on_stack(kbuf)); if (do_copy) bio = bio_copy_kern(q, kbuf, len, gfp_mask, reading); else bio = bio_map_kern(q, kbuf, len, gfp_mask); if (IS_ERR(bio)) return PTR_ERR(bio); if (rq_data_dir(rq) == WRITE) bio->bi_rw |= (1 << BIO_RW); if (do_copy) rq->cmd_flags |= REQ_COPY_USER; blk_rq_bio_prep(q, rq, bio); blk_queue_bounce(q, &rq->bio); rq->buffer = rq->data = NULL; return 0; }