diff options
Diffstat (limited to 'block/bio.c')
| -rw-r--r-- | block/bio.c | 212 |
1 files changed, 78 insertions, 134 deletions
diff --git a/block/bio.c b/block/bio.c index d6e5ba3399f0..515b5434fe2d 100644 --- a/block/bio.c +++ b/block/bio.c @@ -269,7 +269,6 @@ static void bio_free(struct bio *bio) void bio_init(struct bio *bio) { memset(bio, 0, sizeof(*bio)); - bio->bi_flags = 1 << BIO_UPTODATE; atomic_set(&bio->__bi_remaining, 1); atomic_set(&bio->__bi_cnt, 1); } @@ -292,14 +291,17 @@ void bio_reset(struct bio *bio) __bio_free(bio); memset(bio, 0, BIO_RESET_BYTES); - bio->bi_flags = flags | (1 << BIO_UPTODATE); + bio->bi_flags = flags; atomic_set(&bio->__bi_remaining, 1); } EXPORT_SYMBOL(bio_reset); -static void bio_chain_endio(struct bio *bio, int error) +static void bio_chain_endio(struct bio *bio) { - bio_endio(bio->bi_private, error); + struct bio *parent = bio->bi_private; + + parent->bi_error = bio->bi_error; + bio_endio(parent); bio_put(bio); } @@ -309,7 +311,7 @@ static void bio_chain_endio(struct bio *bio, int error) */ static inline void bio_inc_remaining(struct bio *bio) { - bio->bi_flags |= (1 << BIO_CHAIN); + bio_set_flag(bio, BIO_CHAIN); smp_mb__before_atomic(); atomic_inc(&bio->__bi_remaining); } @@ -493,7 +495,7 @@ struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set *bs) if (unlikely(!bvl)) goto err_free; - bio->bi_flags |= 1 << BIO_OWNS_VEC; + bio_set_flag(bio, BIO_OWNS_VEC); } else if (nr_iovecs) { bvl = bio->bi_inline_vecs; } @@ -578,7 +580,7 @@ void __bio_clone_fast(struct bio *bio, struct bio *bio_src) * so we don't set nor calculate new physical/hw segment counts here */ bio->bi_bdev = bio_src->bi_bdev; - bio->bi_flags |= 1 << BIO_CLONED; + bio_set_flag(bio, BIO_CLONED); bio->bi_rw = bio_src->bi_rw; bio->bi_iter = bio_src->bi_iter; bio->bi_io_vec = bio_src->bi_io_vec; @@ -692,31 +694,22 @@ integrity_clone: EXPORT_SYMBOL(bio_clone_bioset); /** - * bio_get_nr_vecs - return approx number of vecs - * @bdev: I/O target + * bio_add_pc_page - attempt to add page to bio + * @q: the target queue + * @bio: destination bio + * @page: page to add + * @len: vec entry length + * @offset: vec entry offset * - * Return the approximate number of pages we can send to this target. - * There's no guarantee that you will be able to fit this number of pages - * into a bio, it does not account for dynamic restrictions that vary - * on 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 up to 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_get_nr_vecs(struct block_device *bdev) -{ - struct request_queue *q = bdev_get_queue(bdev); - int nr_pages; - - nr_pages = min_t(unsigned, - queue_max_segments(q), - queue_max_sectors(q) / (PAGE_SIZE >> 9) + 1); - - return min_t(unsigned, nr_pages, BIO_MAX_PAGES); - -} -EXPORT_SYMBOL(bio_get_nr_vecs); - -static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page - *page, unsigned int len, unsigned int offset, - unsigned int max_sectors) +int bio_add_pc_page(struct request_queue *q, struct bio *bio, struct page + *page, unsigned int len, unsigned int offset) { int retried_segments = 0; struct bio_vec *bvec; @@ -727,7 +720,7 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page if (unlikely(bio_flagged(bio, BIO_CLONED))) return 0; - if (((bio->bi_iter.bi_size + len) >> 9) > max_sectors) + if (((bio->bi_iter.bi_size + len) >> 9) > queue_max_hw_sectors(q)) return 0; /* @@ -740,28 +733,7 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page if (page == prev->bv_page && offset == prev->bv_offset + prev->bv_len) { - unsigned int prev_bv_len = prev->bv_len; prev->bv_len += len; - - if (q->merge_bvec_fn) { - struct bvec_merge_data bvm = { - /* prev_bvec is already charged in - bi_size, discharge it in order to - simulate merging updated prev_bvec - as new bvec. */ - .bi_bdev = bio->bi_bdev, - .bi_sector = bio->bi_iter.bi_sector, - .bi_size = bio->bi_iter.bi_size - - prev_bv_len, - .bi_rw = bio->bi_rw, - }; - - if (q->merge_bvec_fn(q, &bvm, prev) < prev->bv_len) { - prev->bv_len -= len; - return 0; - } - } - bio->bi_iter.bi_size += len; goto done; } @@ -770,8 +742,7 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page * If the queue doesn't support SG gaps and adding this * offset would create a gap, disallow it. */ - if (q->queue_flags & (1 << QUEUE_FLAG_SG_GAPS) && - bvec_gap_to_prev(prev, offset)) + if (bvec_gap_to_prev(q, prev, offset)) return 0; } @@ -804,30 +775,9 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page blk_recount_segments(q, bio); } - /* - * if queue has other restrictions (eg varying max sector size - * depending on offset), it can specify a merge_bvec_fn in the - * queue to get further control - */ - if (q->merge_bvec_fn) { - struct bvec_merge_data bvm = { - .bi_bdev = bio->bi_bdev, - .bi_sector = bio->bi_iter.bi_sector, - .bi_size = bio->bi_iter.bi_size - len, - .bi_rw = bio->bi_rw, - }; - - /* - * merge_bvec_fn() returns number of bytes it can accept - * at this offset - */ - 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 > 1 && (BIOVEC_PHYS_MERGEABLE(bvec-1, bvec))) - bio->bi_flags &= ~(1 << BIO_SEG_VALID); + bio_clear_flag(bio, BIO_SEG_VALID); done: return len; @@ -841,28 +791,6 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page blk_recount_segments(q, bio); return 0; } - -/** - * bio_add_pc_page - attempt to add page to bio - * @q: the target queue - * @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 up to 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(struct request_queue *q, struct bio *bio, struct page *page, - unsigned int len, unsigned int offset) -{ - return __bio_add_page(q, bio, page, len, offset, - queue_max_hw_sectors(q)); -} EXPORT_SYMBOL(bio_add_pc_page); /** @@ -872,22 +800,47 @@ EXPORT_SYMBOL(bio_add_pc_page); * @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 up to PAGE_SIZE, - * so it is always possible to add a single page to an empty bio. + * Attempt to add a page to the bio_vec maplist. This will only fail + * if either bio->bi_vcnt == bio->bi_max_vecs or it's a cloned bio. */ -int bio_add_page(struct bio *bio, struct page *page, unsigned int len, - unsigned int offset) +int bio_add_page(struct bio *bio, struct page *page, + unsigned int len, unsigned int offset) { - struct request_queue *q = bdev_get_queue(bio->bi_bdev); - unsigned int max_sectors; + struct bio_vec *bv; + + /* + * cloned bio must not modify vec list + */ + if (WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED))) + return 0; - max_sectors = blk_max_size_offset(q, bio->bi_iter.bi_sector); - if ((max_sectors < (len >> 9)) && !bio->bi_iter.bi_size) - max_sectors = len >> 9; + /* + * For filesystems with a blocksize smaller than the pagesize + * we will often be called with the same page as last time and + * a consecutive offset. Optimize this special case. + */ + if (bio->bi_vcnt > 0) { + bv = &bio->bi_io_vec[bio->bi_vcnt - 1]; - return __bio_add_page(q, bio, page, len, offset, max_sectors); + if (page == bv->bv_page && + offset == bv->bv_offset + bv->bv_len) { + bv->bv_len += len; + goto done; + } + } + + if (bio->bi_vcnt >= bio->bi_max_vecs) + return 0; + + bv = &bio->bi_io_vec[bio->bi_vcnt]; + bv->bv_page = page; + bv->bv_len = len; + bv->bv_offset = offset; + + bio->bi_vcnt++; +done: + bio->bi_iter.bi_size += len; + return len; } EXPORT_SYMBOL(bio_add_page); @@ -896,11 +849,11 @@ struct submit_bio_ret { int error; }; -static void submit_bio_wait_endio(struct bio *bio, int error) +static void submit_bio_wait_endio(struct bio *bio) { struct submit_bio_ret *ret = bio->bi_private; - ret->error = error; + ret->error = bio->bi_error; complete(&ret->event); } @@ -1388,7 +1341,7 @@ struct bio *bio_map_user_iov(struct request_queue *q, if (iter->type & WRITE) bio->bi_rw |= REQ_WRITE; - bio->bi_flags |= (1 << BIO_USER_MAPPED); + bio_set_flag(bio, BIO_USER_MAPPED); /* * subtle -- if __bio_map_user() ended up bouncing a bio, @@ -1445,7 +1398,7 @@ void bio_unmap_user(struct bio *bio) } EXPORT_SYMBOL(bio_unmap_user); -static void bio_map_kern_endio(struct bio *bio, int err) +static void bio_map_kern_endio(struct bio *bio) { bio_put(bio); } @@ -1501,13 +1454,13 @@ struct bio *bio_map_kern(struct request_queue *q, void *data, unsigned int len, } EXPORT_SYMBOL(bio_map_kern); -static void bio_copy_kern_endio(struct bio *bio, int err) +static void bio_copy_kern_endio(struct bio *bio) { bio_free_pages(bio); bio_put(bio); } -static void bio_copy_kern_endio_read(struct bio *bio, int err) +static void bio_copy_kern_endio_read(struct bio *bio) { char *p = bio->bi_private; struct bio_vec *bvec; @@ -1518,7 +1471,7 @@ static void bio_copy_kern_endio_read(struct bio *bio, int err) p += bvec->bv_len; } - bio_copy_kern_endio(bio, err); + bio_copy_kern_endio(bio); } /** @@ -1768,7 +1721,7 @@ static inline bool bio_remaining_done(struct bio *bio) BUG_ON(atomic_read(&bio->__bi_remaining) <= 0); if (atomic_dec_and_test(&bio->__bi_remaining)) { - clear_bit(BIO_CHAIN, &bio->bi_flags); + bio_clear_flag(bio, BIO_CHAIN); return true; } @@ -1778,25 +1731,15 @@ static inline bool bio_remaining_done(struct bio *bio) /** * bio_endio - end I/O on a bio * @bio: bio - * @error: error, if any * * Description: - * bio_endio() will end I/O on the whole bio. bio_endio() is the - * preferred way to end I/O on a bio, it takes care of clearing - * BIO_UPTODATE on error. @error is 0 on success, and and one of the - * established -Exxxx (-EIO, for instance) error values in case - * something went wrong. No one should call bi_end_io() directly on a - * bio unless they own it and thus know that it has an end_io - * function. + * bio_endio() will end I/O on the whole bio. bio_endio() is the preferred + * way to end I/O on a bio. No one should call bi_end_io() directly on a + * bio unless they own it and thus know that it has an end_io function. **/ -void bio_endio(struct bio *bio, int error) +void bio_endio(struct bio *bio) { while (bio) { - if (error) - clear_bit(BIO_UPTODATE, &bio->bi_flags); - else if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) - error = -EIO; - if (unlikely(!bio_remaining_done(bio))) break; @@ -1810,11 +1753,12 @@ void bio_endio(struct bio *bio, int error) */ if (bio->bi_end_io == bio_chain_endio) { struct bio *parent = bio->bi_private; + parent->bi_error = bio->bi_error; bio_put(bio); bio = parent; } else { if (bio->bi_end_io) - bio->bi_end_io(bio, error); + bio->bi_end_io(bio); bio = NULL; } } @@ -1882,7 +1826,7 @@ void bio_trim(struct bio *bio, int offset, int size) if (offset == 0 && size == bio->bi_iter.bi_size) return; - clear_bit(BIO_SEG_VALID, &bio->bi_flags); + bio_clear_flag(bio, BIO_SEG_VALID); bio_advance(bio, offset << 9); |