Currently when mapping bio to limit bio to a single stripe length, we split bio by adding page to bio one by one, but later we don't modify the vector of bio at all, thus we can use bio_clone_fast to use the original bio vector directly.
Signed-off-by: Liu Bo <bo.li....@oracle.com> --- fs/btrfs/extent_io.c | 15 +++++++ fs/btrfs/extent_io.h | 1 + fs/btrfs/inode.c | 122 +++++++++++++++++++-------------------------------- 3 files changed, 62 insertions(+), 76 deletions(-) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 0d4aea4..1b7156c 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -2726,6 +2726,21 @@ struct bio *btrfs_io_bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs) return bio; } +struct bio *btrfs_bio_clone_partial(struct bio *orig, gfp_t gfp_mask, int offset, int size) +{ + struct bio *bio; + + bio = bio_clone_fast(orig, gfp_mask, btrfs_bioset); + if (bio) { + struct btrfs_io_bio *btrfs_bio = btrfs_io_bio(bio); + btrfs_bio->csum = NULL; + btrfs_bio->csum_allocated = NULL; + btrfs_bio->end_io = NULL; + + bio_trim(bio, (offset >> 9), (size >> 9)); + } + return bio; +} static int __must_check submit_one_bio(struct bio *bio, int mirror_num, unsigned long bio_flags) diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h index 3e4fad4..3b2bc88 100644 --- a/fs/btrfs/extent_io.h +++ b/fs/btrfs/extent_io.h @@ -460,6 +460,7 @@ btrfs_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs, gfp_t gfp_flags); struct bio *btrfs_io_bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs); struct bio *btrfs_bio_clone(struct bio *bio, gfp_t gfp_mask); +struct bio *btrfs_bio_clone_partial(struct bio *orig, gfp_t gfp_mask, int offset, int size); struct btrfs_fs_info; struct btrfs_inode; diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index a18510b..6215720 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -8230,16 +8230,6 @@ static void btrfs_end_dio_bio(struct bio *bio) bio_put(bio); } -static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev, - u64 first_sector, gfp_t gfp_flags) -{ - struct bio *bio; - bio = btrfs_bio_alloc(bdev, first_sector, BIO_MAX_PAGES, gfp_flags); - if (bio) - bio_associate_current(bio); - return bio; -} - static inline int btrfs_lookup_and_bind_dio_csum(struct inode *inode, struct btrfs_dio_private *dip, struct bio *bio, @@ -8329,24 +8319,22 @@ static int btrfs_submit_direct_hook(struct btrfs_dio_private *dip, struct btrfs_root *root = BTRFS_I(inode)->root; struct bio *bio; struct bio *orig_bio = dip->orig_bio; - struct bio_vec *bvec; u64 start_sector = orig_bio->bi_iter.bi_sector; u64 file_offset = dip->logical_offset; - u64 submit_len = 0; u64 map_length; - u32 blocksize = fs_info->sectorsize; int async_submit = 0; - int nr_sectors; + int submit_len; + int clone_offset = 0; + int clone_len; int ret; - int i, j; - map_length = orig_bio->bi_iter.bi_size; + submit_len = map_length = orig_bio->bi_iter.bi_size; ret = btrfs_map_block(fs_info, btrfs_op(orig_bio), start_sector << 9, &map_length, NULL, 0); if (ret) return -EIO; - if (map_length >= orig_bio->bi_iter.bi_size) { + if (map_length >= submit_len) { bio = orig_bio; dip->flags |= BTRFS_DIO_ORIG_BIO_SUBMITTED; goto submit; @@ -8358,70 +8346,52 @@ static int btrfs_submit_direct_hook(struct btrfs_dio_private *dip, else async_submit = 1; - bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS); - if (!bio) - return -ENOMEM; - - bio->bi_opf = orig_bio->bi_opf; - bio->bi_private = dip; - bio->bi_end_io = btrfs_end_dio_bio; - btrfs_io_bio(bio)->logical = file_offset; + /* bio split */ atomic_inc(&dip->pending_bios); + while (submit_len > 0) { + /* map_length < submit_len, it's a int */ + clone_len = min(submit_len, (int)map_length); + bio = btrfs_bio_clone_partial(orig_bio, GFP_NOFS, clone_offset, clone_len); + if (!bio) + goto out_err; + /* the above clone call also clone blkcg of orig_bio */ + + bio->bi_private = dip; + bio->bi_end_io = btrfs_end_dio_bio; + btrfs_io_bio(bio)->logical = file_offset; + + ASSERT(submit_len >= clone_len); + submit_len -= clone_len; + if (submit_len == 0) + break; - bio_for_each_segment_all(bvec, orig_bio, j) { - nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec->bv_len); - i = 0; -next_block: - if (unlikely(map_length < submit_len + blocksize || - bio_add_page(bio, bvec->bv_page, blocksize, - bvec->bv_offset + (i * blocksize)) < blocksize)) { - /* - * inc the count before we submit the bio so - * we know the end IO handler won't happen before - * we inc the count. Otherwise, the dip might get freed - * before we're done setting it up - */ - atomic_inc(&dip->pending_bios); - ret = __btrfs_submit_dio_bio(bio, inode, - file_offset, skip_sum, - async_submit); - if (ret) { - bio_put(bio); - atomic_dec(&dip->pending_bios); - goto out_err; - } - - start_sector += submit_len >> 9; - file_offset += submit_len; - - submit_len = 0; + /* + * increase the count before we submit the bio so we know the + * end IO handler won't happen before we increase the + * count. Otherwise, the dip might get freed before we're done + * setting it up. + */ + atomic_inc(&dip->pending_bios); - bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, - start_sector, GFP_NOFS); - if (!bio) - goto out_err; - bio->bi_opf = orig_bio->bi_opf; - bio->bi_private = dip; - bio->bi_end_io = btrfs_end_dio_bio; - btrfs_io_bio(bio)->logical = file_offset; + ret = __btrfs_submit_dio_bio(bio, inode, + file_offset, skip_sum, + async_submit); + if (ret) { + bio_put(bio); + atomic_dec(&dip->pending_bios); + goto out_err; + } - map_length = orig_bio->bi_iter.bi_size; - ret = btrfs_map_block(fs_info, btrfs_op(orig_bio), - start_sector << 9, - &map_length, NULL, 0); - if (ret) { - bio_put(bio); - goto out_err; - } + clone_offset += clone_len; + start_sector += clone_len >> 9; + file_offset += clone_len; - goto next_block; - } else { - submit_len += blocksize; - if (--nr_sectors) { - i++; - goto next_block; - } - } + map_length = submit_len; + ret = btrfs_map_block(fs_info, btrfs_op(orig_bio), + (start_sector << 9), + &map_length, NULL, 0); + if (ret) + goto out_err; } submit: -- 2.5.5 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html