[PATCHv2] nilfs2: enlarge s_volume_name member in nilfs_super_block

[PATCHv2] nilfs2: enlarge s_volume_name member in nilfs_super_block

[Jiro SEKIBA]

Hi,

Here is the patch against linux-next tree.

Current s_volume_name has 16 bytes, which is too small as modern filesystem.

s_last_mounted resides just after s_volume_name and has 64 bytes.

s_last_mounted is historically came from ext2, but not used in nilfs2 at all.
Deleting s_last_mounted member and merging that space with s_volume_name
enlarge s_volume_name upto 80 bytes for volume label.

When user land tools see the old header for new disk, it will just ignore
additional bytes stored in s_last_mounted.  While, old disk format has only
16 bytes label, it doesn't affects in case seeing the new header for old disk.

Signed-off-by: Jiro SEKIBA <jir-hfpbi5WX9J54Eiagz67IpQ@public.gmane.org>
---
 include/linux/nilfs2_fs.h |    3 +--
 1 files changed, 1 insertions(+), 2 deletions(-)

diff --git a/include/linux/nilfs2_fs.h b/include/linux/nilfs2_fs.h
index 6505c00..8c2c611 100644
--- a/include/linux/nilfs2_fs.h
+++ b/include/linux/nilfs2_fs.h
@@ -207,8 +207,7 @@ struct nilfs_super_block {
 	__le16	s_segment_usage_size;	/* Size of a segment usage */
 
 	__u8	s_uuid[16];		/* 128-bit uuid for volume */
-	char	s_volume_name[16];	/* volume name */
-	char	s_last_mounted[64];	/* directory where last mounted */
+	char	s_volume_name[80];	/* volume name */
 
 	__le32  s_c_interval;           /* Commit interval of segment */
 	__le32  s_c_block_max;          /* Threshold of data amount for
-- 
1.5.6.5

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Re: [PATCHv2] nilfs2: enlarge s_volume_name member in nilfs_super_block

[Ryusuke Konishi]

Hi,
On Sun, 02 May 2010 23:29:04 +0900, Jiro SEKIBA <jir-hfpbi5WX9J54Eiagz67IpQ@public.gmane.org> wrote:
> Hi,
> 
> Here is the patch against linux-next tree.
> 
> Current s_volume_name has 16 bytes, which is too small as modern filesystem.
> 
> s_last_mounted resides just after s_volume_name and has 64 bytes.
> 
> s_last_mounted is historically came from ext2, but not used in nilfs2 at all.
> Deleting s_last_mounted member and merging that space with s_volume_name
> enlarge s_volume_name upto 80 bytes for volume label.
> 
> When user land tools see the old header for new disk, it will just ignore
> additional bytes stored in s_last_mounted.  While, old disk format has only
> 16 bytes label, it doesn't affects in case seeing the new header for old disk.
> 
> Signed-off-by: Jiro SEKIBA <jir-hfpbi5WX9J54Eiagz67IpQ@public.gmane.org>

Applied to the for-next branch.

Thank you!

Ryusuke Konishi

> ---
>  include/linux/nilfs2_fs.h |    3 +--
>  1 files changed, 1 insertions(+), 2 deletions(-)
> 
> diff --git a/include/linux/nilfs2_fs.h b/include/linux/nilfs2_fs.h
> index 6505c00..8c2c611 100644
> --- a/include/linux/nilfs2_fs.h
> +++ b/include/linux/nilfs2_fs.h
> @@ -207,8 +207,7 @@ struct nilfs_super_block {
>  	__le16	s_segment_usage_size;	/* Size of a segment usage */
>  
>  	__u8	s_uuid[16];		/* 128-bit uuid for volume */
> -	char	s_volume_name[16];	/* volume name */
> -	char	s_last_mounted[64];	/* directory where last mounted */
> +	char	s_volume_name[80];	/* volume name */
>  
>  	__le32  s_c_interval;           /* Commit interval of segment */
>  	__le32  s_c_block_max;          /* Threshold of data amount for
> -- 
> 1.5.6.5
> 
> --
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> the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
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