diff options
Diffstat (limited to 'block/blk-map.c')
-rw-r--r-- | block/blk-map.c | 177 |
1 files changed, 66 insertions, 111 deletions
diff --git a/block/blk-map.c b/block/blk-map.c index 6e804892d5ec..21630dccac62 100644 --- a/block/blk-map.c +++ b/block/blk-map.c @@ -12,7 +12,8 @@ #include "blk.h" struct bio_map_data { - int is_our_pages; + bool is_our_pages : 1; + bool is_null_mapped : 1; struct iov_iter iter; struct iovec iov[]; }; @@ -108,7 +109,7 @@ static int bio_uncopy_user(struct bio *bio) struct bio_map_data *bmd = bio->bi_private; int ret = 0; - if (!bio_flagged(bio, BIO_NULL_MAPPED)) { + if (!bmd->is_null_mapped) { /* * if we're in a workqueue, the request is orphaned, so * don't copy into a random user address space, just free @@ -126,24 +127,12 @@ static int bio_uncopy_user(struct bio *bio) return ret; } -/** - * bio_copy_user_iov - copy user data to bio - * @q: destination block queue - * @map_data: pointer to the rq_map_data holding pages (if necessary) - * @iter: iovec iterator - * @gfp_mask: memory allocation flags - * - * Prepares and returns a bio for indirect user io, bouncing data - * to/from kernel pages as necessary. Must be paired with - * call bio_uncopy_user() on io completion. - */ -static struct bio *bio_copy_user_iov(struct request_queue *q, - struct rq_map_data *map_data, struct iov_iter *iter, - gfp_t gfp_mask) +static int bio_copy_user_iov(struct request *rq, struct rq_map_data *map_data, + struct iov_iter *iter, gfp_t gfp_mask) { struct bio_map_data *bmd; struct page *page; - struct bio *bio; + struct bio *bio, *bounce_bio; int i = 0, ret; int nr_pages; unsigned int len = iter->count; @@ -151,14 +140,15 @@ static struct bio *bio_copy_user_iov(struct request_queue *q, bmd = bio_alloc_map_data(iter, gfp_mask); if (!bmd) - return ERR_PTR(-ENOMEM); + return -ENOMEM; /* * We need to do a deep copy of the iov_iter including the iovecs. * The caller provided iov might point to an on-stack or otherwise * shortlived one. */ - bmd->is_our_pages = map_data ? 0 : 1; + bmd->is_our_pages = !map_data; + bmd->is_null_mapped = (map_data && map_data->null_mapped); nr_pages = DIV_ROUND_UP(offset + len, PAGE_SIZE); if (nr_pages > BIO_MAX_PAGES) @@ -168,8 +158,7 @@ static struct bio *bio_copy_user_iov(struct request_queue *q, bio = bio_kmalloc(gfp_mask, nr_pages); if (!bio) goto out_bmd; - - ret = 0; + bio->bi_opf |= req_op(rq); if (map_data) { nr_pages = 1 << map_data->page_order; @@ -186,7 +175,7 @@ static struct bio *bio_copy_user_iov(struct request_queue *q, if (map_data) { if (i == map_data->nr_entries * nr_pages) { ret = -ENOMEM; - break; + goto cleanup; } page = map_data->pages[i / nr_pages]; @@ -194,14 +183,14 @@ static struct bio *bio_copy_user_iov(struct request_queue *q, i++; } else { - page = alloc_page(q->bounce_gfp | gfp_mask); + page = alloc_page(rq->q->bounce_gfp | gfp_mask); if (!page) { ret = -ENOMEM; - break; + goto cleanup; } } - if (bio_add_pc_page(q, bio, page, bytes, offset) < bytes) { + if (bio_add_pc_page(rq->q, bio, page, bytes, offset) < bytes) { if (!map_data) __free_page(page); break; @@ -211,9 +200,6 @@ static struct bio *bio_copy_user_iov(struct request_queue *q, offset = 0; } - if (ret) - goto cleanup; - if (map_data) map_data->offset += bio->bi_iter.bi_size; @@ -233,41 +219,42 @@ static struct bio *bio_copy_user_iov(struct request_queue *q, } bio->bi_private = bmd; - if (map_data && map_data->null_mapped) - bio_set_flag(bio, BIO_NULL_MAPPED); - return bio; + + bounce_bio = bio; + ret = blk_rq_append_bio(rq, &bounce_bio); + if (ret) + goto cleanup; + + /* + * 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(bounce_bio); + return 0; cleanup: if (!map_data) bio_free_pages(bio); bio_put(bio); out_bmd: kfree(bmd); - return ERR_PTR(ret); + return ret; } -/** - * bio_map_user_iov - map user iovec into bio - * @q: the struct request_queue for the bio - * @iter: iovec iterator - * @gfp_mask: memory allocation flags - * - * Map the user space address into a bio suitable for io to a block - * device. Returns an error pointer in case of error. - */ -static struct bio *bio_map_user_iov(struct request_queue *q, - struct iov_iter *iter, gfp_t gfp_mask) +static int bio_map_user_iov(struct request *rq, struct iov_iter *iter, + gfp_t gfp_mask) { - unsigned int max_sectors = queue_max_hw_sectors(q); - int j; - struct bio *bio; + unsigned int max_sectors = queue_max_hw_sectors(rq->q); + struct bio *bio, *bounce_bio; int ret; + int j; if (!iov_iter_count(iter)) - return ERR_PTR(-EINVAL); + return -EINVAL; bio = bio_kmalloc(gfp_mask, iov_iter_npages(iter, BIO_MAX_PAGES)); if (!bio) - return ERR_PTR(-ENOMEM); + return -ENOMEM; + bio->bi_opf |= req_op(rq); while (iov_iter_count(iter)) { struct page **pages; @@ -283,7 +270,7 @@ static struct bio *bio_map_user_iov(struct request_queue *q, npages = DIV_ROUND_UP(offs + bytes, PAGE_SIZE); - if (unlikely(offs & queue_dma_alignment(q))) { + if (unlikely(offs & queue_dma_alignment(rq->q))) { ret = -EINVAL; j = 0; } else { @@ -295,7 +282,7 @@ static struct bio *bio_map_user_iov(struct request_queue *q, if (n > bytes) n = bytes; - if (!bio_add_hw_page(q, bio, page, n, offs, + if (!bio_add_hw_page(rq->q, bio, page, n, offs, max_sectors, &same_page)) { if (same_page) put_page(page); @@ -319,21 +306,31 @@ static struct bio *bio_map_user_iov(struct request_queue *q, break; } - bio_set_flag(bio, BIO_USER_MAPPED); - /* - * subtle -- if bio_map_user_iov() ended up bouncing a bio, - * it would normally disappear when its bi_end_io is run. - * however, we need it for the unmap, so grab an extra - * reference to it + * Subtle: if we end up needing to bounce a bio, it would normally + * disappear when its bi_end_io is run. However, we need the original + * bio for the unmap, so grab an extra reference to it */ bio_get(bio); - return bio; + bounce_bio = bio; + ret = blk_rq_append_bio(rq, &bounce_bio); + if (ret) + goto out_put_orig; + + /* + * 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(bounce_bio); + return 0; + + out_put_orig: + bio_put(bio); out_unmap: bio_release_pages(bio, false); bio_put(bio); - return ERR_PTR(ret); + return ret; } /** @@ -557,55 +554,6 @@ int blk_rq_append_bio(struct request *rq, struct bio **bio) } EXPORT_SYMBOL(blk_rq_append_bio); -static int __blk_rq_unmap_user(struct bio *bio) -{ - int ret = 0; - - if (bio) { - if (bio_flagged(bio, BIO_USER_MAPPED)) - bio_unmap_user(bio); - else - ret = bio_uncopy_user(bio); - } - - return ret; -} - -static int __blk_rq_map_user_iov(struct request *rq, - struct rq_map_data *map_data, struct iov_iter *iter, - gfp_t gfp_mask, bool copy) -{ - struct request_queue *q = rq->q; - struct bio *bio, *orig_bio; - int ret; - - if (copy) - bio = bio_copy_user_iov(q, map_data, iter, gfp_mask); - else - bio = bio_map_user_iov(q, iter, gfp_mask); - - if (IS_ERR(bio)) - return PTR_ERR(bio); - - bio->bi_opf &= ~REQ_OP_MASK; - bio->bi_opf |= req_op(rq); - - orig_bio = 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 - */ - ret = blk_rq_append_bio(rq, &bio); - if (ret) { - __blk_rq_unmap_user(orig_bio); - return ret; - } - bio_get(bio); - - return 0; -} - /** * blk_rq_map_user_iov - map user data to a request, for passthrough requests * @q: request queue where request should be inserted @@ -649,7 +597,10 @@ int blk_rq_map_user_iov(struct request_queue *q, struct request *rq, i = *iter; do { - ret =__blk_rq_map_user_iov(rq, map_data, &i, gfp_mask, copy); + if (copy) + ret = bio_copy_user_iov(rq, map_data, &i, gfp_mask); + else + ret = bio_map_user_iov(rq, &i, gfp_mask); if (ret) goto unmap_rq; if (!bio) @@ -700,9 +651,13 @@ int blk_rq_unmap_user(struct bio *bio) if (unlikely(bio_flagged(bio, BIO_BOUNCED))) mapped_bio = bio->bi_private; - ret2 = __blk_rq_unmap_user(mapped_bio); - if (ret2 && !ret) - ret = ret2; + if (bio->bi_private) { + ret2 = bio_uncopy_user(mapped_bio); + if (ret2 && !ret) + ret = ret2; + } else { + bio_unmap_user(mapped_bio); + } mapped_bio = bio; bio = bio->bi_next; |