[PATCH 7/8] btrfs: refactor __btrfs_lookup_bio_sums to use bio_for_each_segment_all
From: Christoph Hellwig <hch@lst.de>
Date: 2016-11-25 08:37:53
Subsystem:
btrfs file system, filesystems (vfs and infrastructure), the rest · Maintainers:
Chris Mason, David Sterba, Alexander Viro, Christian Brauner, Linus Torvalds
Rework the loop a little bit to use the generic bio_for_each_segment_all helper for iterating over the bio. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Omar Sandoval <redacted> --- fs/btrfs/file-item.c | 32 +++++++++++--------------------- 1 file changed, 11 insertions(+), 21 deletions(-)
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index fa8aa53..6b8fda3 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c@@ -163,7 +163,7 @@ static int __btrfs_lookup_bio_sums(struct btrfs_root *root, struct inode *inode, struct bio *bio, u64 logical_offset, u32 *dst, int dio) { - struct bio_vec *bvec = bio->bi_io_vec; + struct bio_vec *bvec; struct btrfs_io_bio *btrfs_bio = btrfs_io_bio(bio); struct btrfs_csum_item *item = NULL; struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
@@ -176,8 +176,7 @@ static int __btrfs_lookup_bio_sums(struct btrfs_root *root, u64 page_bytes_left; u32 diff; int nblocks; - int bio_index = 0; - int count; + int count = 0, i; u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy); path = btrfs_alloc_path();
@@ -223,8 +222,11 @@ static int __btrfs_lookup_bio_sums(struct btrfs_root *root, if (dio) offset = logical_offset; - page_bytes_left = bvec->bv_len; - while (bio_index < bio->bi_vcnt) { + bio_for_each_segment_all(bvec, bio, i) { + page_bytes_left = bvec->bv_len; + if (count) + goto next; + if (!dio) offset = page_offset(bvec->bv_page) + bvec->bv_offset; count = btrfs_find_ordered_sum(inode, offset, disk_bytenr,
@@ -285,29 +287,17 @@ static int __btrfs_lookup_bio_sums(struct btrfs_root *root, found: csum += count * csum_size; nblocks -= count; - +next: while (count--) { disk_bytenr += root->sectorsize; offset += root->sectorsize; page_bytes_left -= root->sectorsize; - if (!page_bytes_left) { - bio_index++; - /* - * make sure we're still inside the - * bio before we update page_bytes_left - */ - if (bio_index >= bio->bi_vcnt) { - WARN_ON_ONCE(count); - goto done; - } - bvec++; - page_bytes_left = bvec->bv_len; - } - + if (!page_bytes_left) + break; /* move to next bio */ } } -done: + WARN_ON_ONCE(count); btrfs_free_path(path); return 0; }
--
2.1.4