diff options
Diffstat (limited to 'fs/bio.c')
| -rw-r--r-- | fs/bio.c | 38 |
1 files changed, 30 insertions, 8 deletions
@@ -313,7 +313,8 @@ int bio_get_nr_vecs(struct block_device *bdev) } static int __bio_add_page(request_queue_t *q, struct bio *bio, struct page - *page, unsigned int len, unsigned int offset) + *page, unsigned int len, unsigned int offset, + unsigned short max_sectors) { int retried_segments = 0; struct bio_vec *bvec; @@ -327,7 +328,7 @@ static int __bio_add_page(request_queue_t *q, struct bio *bio, struct page if (bio->bi_vcnt >= bio->bi_max_vecs) return 0; - if (((bio->bi_size + len) >> 9) > q->max_sectors) + if (((bio->bi_size + len) >> 9) > max_sectors) return 0; /* @@ -386,6 +387,25 @@ static int __bio_add_page(request_queue_t *q, struct bio *bio, struct page } /** + * bio_add_pc_page - attempt to add page to bio + * @bio: destination bio + * @page: page to add + * @len: vec entry length + * @offset: vec entry offset + * + * Attempt to add a page to the bio_vec maplist. This can fail for a + * number of reasons, such as the bio being full or target block + * device limitations. The target block device must allow bio's + * smaller than PAGE_SIZE, so it is always possible to add a single + * page to an empty bio. This should only be used by REQ_PC bios. + */ +int bio_add_pc_page(request_queue_t *q, struct bio *bio, struct page *page, + unsigned int len, unsigned int offset) +{ + return __bio_add_page(q, bio, page, len, offset, q->max_hw_sectors); +} + +/** * bio_add_page - attempt to add page to bio * @bio: destination bio * @page: page to add @@ -401,8 +421,8 @@ static int __bio_add_page(request_queue_t *q, struct bio *bio, struct page int bio_add_page(struct bio *bio, struct page *page, unsigned int len, unsigned int offset) { - return __bio_add_page(bdev_get_queue(bio->bi_bdev), bio, page, - len, offset); + struct request_queue *q = bdev_get_queue(bio->bi_bdev); + return __bio_add_page(q, bio, page, len, offset, q->max_sectors); } struct bio_map_data { @@ -514,7 +534,7 @@ struct bio *bio_copy_user(request_queue_t *q, unsigned long uaddr, break; } - if (__bio_add_page(q, bio, page, bytes, 0) < bytes) { + if (bio_add_pc_page(q, bio, page, bytes, 0) < bytes) { ret = -EINVAL; break; } @@ -628,7 +648,8 @@ static struct bio *__bio_map_user_iov(request_queue_t *q, /* * sorry... */ - if (__bio_add_page(q, bio, pages[j], bytes, offset) < bytes) + if (bio_add_pc_page(q, bio, pages[j], bytes, offset) < + bytes) break; len -= bytes; @@ -801,8 +822,8 @@ static struct bio *__bio_map_kern(request_queue_t *q, void *data, if (bytes > len) bytes = len; - if (__bio_add_page(q, bio, virt_to_page(data), bytes, - offset) < bytes) + if (bio_add_pc_page(q, bio, virt_to_page(data), bytes, + offset) < bytes) break; data += bytes; @@ -1228,6 +1249,7 @@ EXPORT_SYMBOL(bio_clone); EXPORT_SYMBOL(bio_phys_segments); EXPORT_SYMBOL(bio_hw_segments); EXPORT_SYMBOL(bio_add_page); +EXPORT_SYMBOL(bio_add_pc_page); EXPORT_SYMBOL(bio_get_nr_vecs); EXPORT_SYMBOL(bio_map_user); EXPORT_SYMBOL(bio_unmap_user); |