[PATCH] btrfs-progs: ctree.h: Sync the comment for btrfs_file_extent_item

[PATCH] btrfs-progs: ctree.h: Sync the comment for btrfs_file_extent_item

[Qu Wenruo]

The comment about data checksum on disk_bytes is completely wrong.

Sync it with fixed kernel comment to avoid confusion.

Signed-off-by: Qu Wenruo <wqu@suse.com>
---
 ctree.h | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/ctree.h b/ctree.h
index 3e50d086..9459adf1 100644
--- a/ctree.h
+++ b/ctree.h
@@ -916,13 +916,16 @@ struct btrfs_file_extent_item {
 	u8 type;
 
 	/*
-	 * disk space consumed by the extent, checksum blocks are included
-	 * in these numbers
+	 * disk space consumed by the data extent
+	 * Data checksum is stored in csum tree, thus no bytenr/length takes
+	 * csum into consideration.
+	 *
+	 * At this offset in the structure, the inline extent data starts.
 	 */
 	__le64 disk_bytenr;
 	__le64 disk_num_bytes;
 	/*
-	 * the logical offset in file blocks (no csums)
+	 * the logical offset in file blocks
 	 * this extent record is for.  This allows a file extent to point
 	 * into the middle of an existing extent on disk, sharing it
 	 * between two snapshots (useful if some bytes in the middle of the
@@ -930,7 +933,8 @@ struct btrfs_file_extent_item {
 	 */
 	__le64 offset;
 	/*
-	 * the logical number of file blocks (no csums included)
+	 * the logical number of file blocks. This always reflects the size
+	 * uncompressed and without encoding.
 	 */
 	__le64 num_bytes;
 
-- 
2.24.1

Re: [PATCH] btrfs-progs: ctree.h: Sync the comment for btrfs_file_extent_item

[Su Yue]

On 2019/12/17 2:52 PM, Qu Wenruo wrote:
> The comment about data checksum on disk_bytes is completely wrong.
>
> Sync it with fixed kernel comment to avoid confusion.
>
> Signed-off-by: Qu Wenruo <wqu@suse.com>

LGTM.

Reviewed-by: Su Yue <Damenly_Su@gmx.com>

> ---
>   ctree.h | 12 ++++++++----
>   1 file changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/ctree.h b/ctree.h
> index 3e50d086..9459adf1 100644
> --- a/ctree.h
> +++ b/ctree.h
> @@ -916,13 +916,16 @@ struct btrfs_file_extent_item {
>   	u8 type;
>
>   	/*
> -	 * disk space consumed by the extent, checksum blocks are included
> -	 * in these numbers
> +	 * disk space consumed by the data extent
> +	 * Data checksum is stored in csum tree, thus no bytenr/length takes
> +	 * csum into consideration.
> +	 *
> +	 * At this offset in the structure, the inline extent data starts.
>   	 */
>   	__le64 disk_bytenr;
>   	__le64 disk_num_bytes;
>   	/*
> -	 * the logical offset in file blocks (no csums)
> +	 * the logical offset in file blocks
>   	 * this extent record is for.  This allows a file extent to point
>   	 * into the middle of an existing extent on disk, sharing it
>   	 * between two snapshots (useful if some bytes in the middle of the
> @@ -930,7 +933,8 @@ struct btrfs_file_extent_item {
>   	 */
>   	__le64 offset;
>   	/*
> -	 * the logical number of file blocks (no csums included)
> +	 * the logical number of file blocks. This always reflects the size
> +	 * uncompressed and without encoding.
>   	 */
>   	__le64 num_bytes;
>
>

Re: [PATCH] btrfs-progs: ctree.h: Sync the comment for btrfs_file_extent_item

[David Sterba]

On Tue, Dec 17, 2019 at 02:52:40PM +0800, Qu Wenruo wrote:
> The comment about data checksum on disk_bytes is completely wrong.
> 
> Sync it with fixed kernel comment to avoid confusion.
> 
> Signed-off-by: Qu Wenruo <wqu@suse.com>

Applied, thanks.