diff options
| -rw-r--r-- | block/bio.c | 60 |
1 files changed, 31 insertions, 29 deletions
diff --git a/block/bio.c b/block/bio.c index 26853e072cd7..8d516d508ae3 100644 --- a/block/bio.c +++ b/block/bio.c @@ -665,6 +665,27 @@ static inline bool page_is_mergeable(const struct bio_vec *bv, return true; } +/* + * Check if the @page can be added to the current segment(@bv), and make + * sure to call it only if page_is_mergeable(@bv, @page) is true + */ +static bool can_add_page_to_seg(struct request_queue *q, + struct bio_vec *bv, struct page *page, unsigned len, + unsigned offset) +{ + unsigned long mask = queue_segment_boundary(q); + phys_addr_t addr1 = page_to_phys(bv->bv_page) + bv->bv_offset; + phys_addr_t addr2 = page_to_phys(page) + offset + len - 1; + + if ((addr1 | mask) != (addr2 | mask)) + return false; + + if (bv->bv_len + len > queue_max_segment_size(q)) + return false; + + return true; +} + /** * __bio_add_pc_page - attempt to add page to passthrough bio * @q: the target queue @@ -685,7 +706,6 @@ int __bio_add_pc_page(struct request_queue *q, struct bio *bio, struct page *page, unsigned int len, unsigned int offset, bool put_same_page) { - int retried_segments = 0; struct bio_vec *bvec; /* @@ -709,6 +729,7 @@ int __bio_add_pc_page(struct request_queue *q, struct bio *bio, offset == bvec->bv_offset + bvec->bv_len) { if (put_same_page) put_page(page); + bvec_merge: bvec->bv_len += len; bio->bi_iter.bi_size += len; goto done; @@ -720,11 +741,18 @@ int __bio_add_pc_page(struct request_queue *q, struct bio *bio, */ if (bvec_gap_to_prev(q, bvec, offset)) return 0; + + if (page_is_mergeable(bvec, page, len, offset, false) && + can_add_page_to_seg(q, bvec, page, len, offset)) + goto bvec_merge; } if (bio_full(bio)) return 0; + if (bio->bi_phys_segments >= queue_max_segments(q)) + return 0; + /* * setup the new entry, we might clear it again later if we * cannot add the page @@ -734,38 +762,12 @@ int __bio_add_pc_page(struct request_queue *q, struct bio *bio, 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 we may be able to merge these biovecs, force a recount */ - if (bio->bi_vcnt > 1 && biovec_phys_mergeable(q, bvec - 1, bvec)) - bio_clear_flag(bio, BIO_SEG_VALID); - done: + bio->bi_phys_segments = bio->bi_vcnt; + bio_set_flag(bio, BIO_SEG_VALID); 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; } EXPORT_SYMBOL(__bio_add_pc_page); |