diff --git a/block/bio.c b/block/bio.c index 3d4a072375ef..471d7382c7d1 100644 --- a/block/bio.c +++ b/block/bio.c @@ -748,6 +748,7 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page } } + bio->bi_iter.bi_size += len; goto done; } @@ -763,20 +764,6 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page if (bio->bi_vcnt >= bio->bi_max_vecs) return 0; - /* - * we might lose a segment or two here, but rather that than - * make this too complex. - */ - - while (bio->bi_phys_segments >= queue_max_segments(q)) { - - if (retried_segments) - return 0; - - retried_segments = 1; - blk_recount_segments(q, bio); - } - /* * setup the new entry, we might clear it again later if we * cannot add the page @@ -785,6 +772,23 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page bvec->bv_page = page; bvec->bv_len = len; bvec->bv_offset = offset; + bio->bi_vcnt++; + bio->bi_phys_segments++; + bio->bi_iter.bi_size += len; + + /* + * Perform a recount if the number of segments is greater + * than queue_max_segments(q). + */ + + while (bio->bi_phys_segments > queue_max_segments(q)) { + + if (retried_segments) + goto failed; + + retried_segments = 1; + blk_recount_segments(q, bio); + } /* * if queue has other restrictions (eg varying max sector size @@ -795,7 +799,7 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page struct bvec_merge_data bvm = { .bi_bdev = bio->bi_bdev, .bi_sector = bio->bi_iter.bi_sector, - .bi_size = bio->bi_iter.bi_size, + .bi_size = bio->bi_iter.bi_size - len, .bi_rw = bio->bi_rw, }; @@ -803,23 +807,25 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page * merge_bvec_fn() returns number of bytes it can accept * at this offset */ - if (q->merge_bvec_fn(q, &bvm, bvec) < bvec->bv_len) { - bvec->bv_page = NULL; - bvec->bv_len = 0; - bvec->bv_offset = 0; - return 0; - } + if (q->merge_bvec_fn(q, &bvm, bvec) < bvec->bv_len) + goto failed; } /* If we may be able to merge these biovecs, force a recount */ - if (bio->bi_vcnt && (BIOVEC_PHYS_MERGEABLE(bvec-1, bvec))) + if (bio->bi_vcnt > 1 && (BIOVEC_PHYS_MERGEABLE(bvec-1, bvec))) bio->bi_flags &= ~(1 << BIO_SEG_VALID); - bio->bi_vcnt++; - bio->bi_phys_segments++; done: - bio->bi_iter.bi_size += len; return len; + + failed: + bvec->bv_page = NULL; + bvec->bv_len = 0; + bvec->bv_offset = 0; + bio->bi_vcnt--; + bio->bi_iter.bi_size -= len; + blk_recount_segments(q, bio); + return 0; } /**