[Cluster-devel] [GFS2 PATCH][v4] GFS2: Introduce new gfs2_log_header_v2

[Andrew Price]

On 04/01/18 16:51, Bob Peterson wrote:
<snip>
> diff --git a/include/uapi/linux/gfs2_ondisk.h b/include/uapi/linux/gfs2_ondisk.h
> index 09f0920f07e9..7eb73c32272f 100644
> --- a/include/uapi/linux/gfs2_ondisk.h
> +++ b/include/uapi/linux/gfs2_ondisk.h
> @@ -403,7 +403,15 @@ struct gfs2_ea_header {
>    * Log header structure
>    */
>   
> -#define GFS2_LOG_HEAD_UNMOUNT	0x00000001	/* log is clean */
> +#define GFS2_LOG_HEAD_UNMOUNT		0x00000001 /* log is clean */
> +#define GFS2_LOG_HEAD_FLUSH_NORMAL	0x00000002 /* normal log flush */
> +#define GFS2_LOG_HEAD_FLUSH_SYNC	0x00000004 /* Sync log flush */
> +#define GFS2_LOG_HEAD_FLUSH_SHUTDOWN	0x00000008 /* Shutdown log flush */
> +#define GFS2_LOG_HEAD_FLUSH_FREEZE	0x00000010 /* Freeze flush */
> +#define GFS2_LOG_HEAD_RECOVERY		0x00000020 /* Journal recovery */
> +#define GFS2_LOG_HEAD_USERSPACE		0x80000000 /* Written by gfs2-utils */
> +
> +#define LH_V1_SIZE (offsetofend(struct gfs2_log_header, lh_hash))
>   
>   struct gfs2_log_header {
>   	struct gfs2_meta_header lh_header;
> @@ -413,6 +421,21 @@ struct gfs2_log_header {
>   	__be32 lh_tail;		/* Block number of log tail */
>   	__be32 lh_blkno;
>   	__be32 lh_hash;
> +
> +	/* Version 2 additional fields start here */
> +	__be32 lh_crc;		/* crc32 of whole block with this field 0 */
> +	__be32 lh_nsec;		/* Nano second time stamp */
> +	__be64 lh_sec;		/* Second based time stamp */
> +	__be64 lh_addr;		/* Block addr of this log header (absolute) */
> +	__be64 lh_jinode;	/* Journal inode number */
> +	__be64 lh_statfs_addr;	/* Local statfs inode number */
> +	__be64 lh_quota_addr;	/* Local quota change inode number */
> +
> +	/* Statfs local changes (i.e. diff from global statfs) */
> +	__be64 lh_local_total;
> +	__be64 lh_local_free;
> +	__be64 lh_local_dinodes;
> +	__be32 lh_log_origin;	/* The origin of this log header */
>   };
>   
>   /*
> 

Thinking about tools like fsck.gfs2, which will be built with the new 
header but could be looking at older structures on-disk, how would it 
know whether to treat the log header as a v1 or v2?

Andy