For target mode we could end up with the case where we get very large request from the initiator. The request could be so large that we cannot transfer all the data in one operation. For example the HBA's segment or max_sector limits might limit us to a 1 MB transfer. To send a 5 MB command then we need to transfer the command chunk by chunk. To do this, tgt core will map in as much data as possible into a bio, send this off, then when that transfer is completed we send off another request/bio. To be able to pack as much data into a bio as possible we need bio_map_user to support partially mapped bios. Following the comments from Jens on the original patch: http://marc.theaimsgroup.com/?l=linux-scsi&m=114012008928530&w=2 This patch will revoke changes by the original patch. Signed-off-by: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx> Signed-off-by: Mike Christie <michaelc@xxxxxxxxxxx> --- block/ll_rw_blk.c | 5 ++--- fs/bio.c | 11 ++++------- include/linux/bio.h | 5 ++--- 3 files changed, 8 insertions(+), 13 deletions(-) 4d84a7a7218de12ef1e3f58a0a5514a730994848 diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c index 13c40a0..03d9c82 100644 --- a/block/ll_rw_blk.c +++ b/block/ll_rw_blk.c @@ -2287,7 +2287,7 @@ int blk_rq_map_user(request_queue_t *q, */ uaddr = (unsigned long) ubuf; if (!(uaddr & queue_dma_alignment(q)) && !(len & queue_dma_alignment(q))) - bio = bio_map_user(q, NULL, uaddr, len, reading, 0); + bio = bio_map_user(q, NULL, uaddr, len, reading); else bio = bio_copy_user(q, uaddr, len, reading); @@ -2339,8 +2339,7 @@ int blk_rq_map_user_iov(request_queue_t /* we don't allow misaligned data like bio_map_user() does. If the * user is using sg, they're expected to know the alignment constraints * and respect them accordingly */ - bio = bio_map_user_iov(q, NULL, iov, iov_count, rq_data_dir(rq)== READ, - 0); + bio = bio_map_user_iov(q, NULL, iov, iov_count, rq_data_dir(rq)== READ); if (IS_ERR(bio)) return PTR_ERR(bio); diff --git a/fs/bio.c b/fs/bio.c index 3e940c9..d8259d9 100644 --- a/fs/bio.c +++ b/fs/bio.c @@ -718,21 +718,19 @@ static struct bio *__bio_map_user_iov(re * @uaddr: start of user address * @len: length in bytes * @write_to_vm: bool indicating writing to pages or not - * @support_partial: support partial mappings * * Map the user space address into a bio suitable for io to a block * device. Returns an error pointer in case of error. */ struct bio *bio_map_user(request_queue_t *q, struct block_device *bdev, - unsigned long uaddr, unsigned int len, int write_to_vm, - int support_partial) + unsigned long uaddr, unsigned int len, int write_to_vm) { struct sg_iovec iov; iov.iov_base = (void __user *)uaddr; iov.iov_len = len; - return bio_map_user_iov(q, bdev, &iov, 1, write_to_vm, support_partial); + return bio_map_user_iov(q, bdev, &iov, 1, write_to_vm); } /** @@ -742,14 +740,13 @@ struct bio *bio_map_user(request_queue_t * @iov: the iovec. * @iov_count: number of elements in the iovec * @write_to_vm: bool indicating writing to pages or not - * @support_partial: support partial mappings * * Map the user space address into a bio suitable for io to a block * device. Returns an error pointer in case of error. */ struct bio *bio_map_user_iov(request_queue_t *q, struct block_device *bdev, struct sg_iovec *iov, int iov_count, - int write_to_vm, int support_partial) + int write_to_vm) { struct bio *bio; int len = 0, i; @@ -770,7 +767,7 @@ struct bio *bio_map_user_iov(request_que for (i = 0; i < iov_count; i++) len += iov[i].iov_len; - if (bio->bi_size == len || support_partial) + if (bio->bi_size == len) return bio; /* diff --git a/include/linux/bio.h b/include/linux/bio.h index fc0906c..b60ffe3 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -295,13 +295,12 @@ extern int bio_add_page(struct bio *, st extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *, unsigned int, unsigned int); extern int bio_get_nr_vecs(struct block_device *); -extern int __bio_get_nr_vecs(struct request_queue *); extern struct bio *bio_map_user(struct request_queue *, struct block_device *, - unsigned long, unsigned int, int, int); + unsigned long, unsigned int, int); struct sg_iovec; extern struct bio *bio_map_user_iov(struct request_queue *, struct block_device *, - struct sg_iovec *, int, int, int); + struct sg_iovec *, int, int); extern void bio_unmap_user(struct bio *); extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int, gfp_t); -- 1.1.5 - : send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
