[Ocfs2-tools-devel] [PATCH 3/3] debugfs.ocfs2: Add the -t and -T options to the "stat" command.

[Sunil Mushran]

Why not just -T. Any advantage of having a specific option for
the default.

On 06/07/2010 02:48 PM, Joel Becker wrote:
> The "stat" command walks the extents or chains of an inode to print
> details about its metadata.  This can be expensive when there are a lot
> of extents or chains and the user merely wants information from the
> inode itself.  The -t and -T options select and deselect traversal of
> the this metadata respectively.  The -t option remains the default.
>
> Signed-off-by: Joel Becker<joel.becker at oracle.com>
> ---
>   debugfs.ocfs2/commands.c         |   55 +++++++++++++++++++++++++++----------
>   debugfs.ocfs2/debugfs.ocfs2.8.in |    8 ++++-
>   2 files changed, 46 insertions(+), 17 deletions(-)
>
> diff --git a/debugfs.ocfs2/commands.c b/debugfs.ocfs2/commands.c
> index e546dc2..1f60049 100644
> --- a/debugfs.ocfs2/commands.c
> +++ b/debugfs.ocfs2/commands.c
> @@ -874,7 +874,7 @@ static void do_help (char **args)
>   	printf ("refcount [-e]<filespec>\t\t\tDump the refcount tree "
>   		"for the specified inode or refcount block\n");
>   	printf ("slotmap\t\t\t\t\tShow slot map\n");
> -	printf ("stat<filespec>\t\t\t\tShow inode\n");
> +	printf ("stat [-t|-T]<filespec>\t\t\t\tShow inode\n");
>   	printf ("stats [-h]\t\t\t\tShow superblock\n");
>   	printf ("xattr [-v]<filespec>\t\t\tShow Extended Attributes\n");
>   }
> @@ -1041,9 +1041,28 @@ static void do_stat (char **args)
>   	char *buf = NULL;
>   	FILE *out;
>   	errcode_t ret = 0;
> +	const char *stat_usage = "usage: stat [-t|-T]<filespec>";
> +	int index = 1, traverse = 1;
>
> -	if (process_inode_args(args,&blkno))
> +	if (!args[index]) {
> +		fprintf(stderr, "%s\n", stat_usage);
> +		return ;
> +	}
> +
> +	if (!strncmp(args[index], "-t", 2)) {
> +		traverse = 1;
> +		index++;
> +	} else if (!strncmp(args[index], "-T", 2)) {
> +		traverse = 0;
> +		index++;
> +	}
> +
> +	ret = string_to_inode(gbls.fs, gbls.root_blkno, gbls.cwd_blkno,
> +			      args[index],&blkno);
> +	if (ret) {
> +		com_err(args[0], ret, "'%s'", args[index]);
>   		return ;
> +	}
>
>   	buf = gbls.blockbuf;
>   	ret = ocfs2_read_inode(gbls.fs, blkno, buf);
> @@ -1057,20 +1076,26 @@ static void do_stat (char **args)
>   	out = open_pager(gbls.interactive);
>   	dump_inode(out, inode);
>
> -	if ((inode->i_flags&  OCFS2_LOCAL_ALLOC_FL))
> -		dump_local_alloc(out,&(inode->id2.i_lab));
> -	else if ((inode->i_flags&  OCFS2_CHAIN_FL))
> -		ret = traverse_chains(gbls.fs,&(inode->id2.i_chain), out);
> -	else if (S_ISLNK(inode->i_mode)&&  !inode->i_clusters)
> -		dump_fast_symlink(out, (char *)inode->id2.i_symlink);
> -	else if (inode->i_flags&  OCFS2_DEALLOC_FL)
> -		dump_truncate_log(out,&(inode->id2.i_dealloc));
> -	else if (!(inode->i_dyn_features&  OCFS2_INLINE_DATA_FL))
> -		ret = traverse_extents(gbls.fs,&(inode->id2.i_list), out);
> +	if (traverse) {
> +		if ((inode->i_flags&  OCFS2_LOCAL_ALLOC_FL))
> +			dump_local_alloc(out,&(inode->id2.i_lab));
> +		else if ((inode->i_flags&  OCFS2_CHAIN_FL))
> +			ret = traverse_chains(gbls.fs,
> +					&(inode->id2.i_chain), out);
> +		else if (S_ISLNK(inode->i_mode)&&  !inode->i_clusters)
> +			dump_fast_symlink(out,
> +					  (char *)inode->id2.i_symlink);
> +		else if (inode->i_flags&  OCFS2_DEALLOC_FL)
> +			dump_truncate_log(out,&(inode->id2.i_dealloc));
> +		else if (!(inode->i_dyn_features&  OCFS2_INLINE_DATA_FL))
> +			ret = traverse_extents(gbls.fs,
> +					&(inode->id2.i_list), out);
>
> -	if (ret)
> -		com_err(args[0], ret, "while traversing inode at block "
> -			"%"PRIu64, blkno);
> +		if (ret)
> +			com_err(args[0], ret,
> +				"while traversing inode at block "
> +				"%"PRIu64, blkno);
> +	}
>
>   	close_pager(out);
>
> diff --git a/debugfs.ocfs2/debugfs.ocfs2.8.in b/debugfs.ocfs2/debugfs.ocfs2.8.in
> index c4b9cdd..978741c 100644
> --- a/debugfs.ocfs2/debugfs.ocfs2.8.in
> +++ b/debugfs.ocfs2/debugfs.ocfs2.8.in
> @@ -235,8 +235,12 @@ Display the refcount block, and optionally its tree, of the specified inode.
>   Display the contents of the \fIslotmap\fR system file.
>
>   .TP
> -\fIstat filespec\fR
> -Display the contents of the inode structure for the \fIfilespec\fR.
> +\fIstat [\-t|\-T] filespec\fR
> +Display the contents of the inode structure for the \fIfilespec\fR.  The
> +\fI-t\fR ("traverse") option selects traversal of the inode's metadata.
> +The extent tree, chain list, or other extra metadata will be dumped.  This
> +is the default.  The \fI-T\fR option turns off traversal to reduce the I/O
> +required when basic inode information is needed.
>
>   .TP
>   \fIstats [\-h] [\-s backup\-number]\fR
>