[7/9] btrfs: refactor __btrfs_lookup_bio_sums to use bio_for_each_segment_all
diff mbox

Message ID 1479300736-9724-8-git-send-email-hch@lst.de
State Superseded
Headers show

Commit Message

Christoph Hellwig Nov. 16, 2016, 12:52 p.m. UTC
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>
---
 fs/btrfs/file-item.c | 31 +++++++++++--------------------
 1 file changed, 11 insertions(+), 20 deletions(-)

Comments

Omar Sandoval Nov. 18, 2016, 8:31 p.m. UTC | #1
On Wed, Nov 16, 2016 at 01:52:14PM +0100, Christoph Hellwig wrote:
> Rework the loop a little bit to use the generic bio_for_each_segment_all
> helper for iterating over the bio.

One minor nit. Besides that,

Reviewed-by: Omar Sandoval <osandov@fb.com>

> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  fs/btrfs/file-item.c | 31 +++++++++++--------------------
>  1 file changed, 11 insertions(+), 20 deletions(-)
> 
> diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
> index fa8aa53..54ccb91 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;
> @@ -177,7 +177,7 @@ static int __btrfs_lookup_bio_sums(struct btrfs_root *root,
>  	u32 diff;
>  	int nblocks;
>  	int bio_index = 0;
> -	int count;
> +	int count = 0;
>  	u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
>  
>  	path = btrfs_alloc_path();
> @@ -223,8 +223,11 @@ 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, bio_index) {

Can we just rename bio_index to i now?

> +		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 +288,17 @@ 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
> 
> --
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Patch
diff mbox

diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index fa8aa53..54ccb91 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;
@@ -177,7 +177,7 @@  static int __btrfs_lookup_bio_sums(struct btrfs_root *root,
 	u32 diff;
 	int nblocks;
 	int bio_index = 0;
-	int count;
+	int count = 0;
 	u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
 
 	path = btrfs_alloc_path();
@@ -223,8 +223,11 @@  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, bio_index) {
+		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 +288,17 @@  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;
 }