Re: [PATCH 1/3] Btrfs-progs: move path modification to filters

["Lukáš Czerner" <lczerner@redhat.com>]

On Tue, 11 Dec 2012, Lukas Czerner wrote:

> Date: Tue, 11 Dec 2012 15:24:58 +0100
> From: Lukas Czerner <lczerner@redhat.com>
> To: linux-btrfs@vger.kernel.org
> Cc: chris.mason@fusionio.com, cwillu@cwillu.com,
>     Lukas Czerner <lczerner@redhat.com>
> Subject: [PATCH 1/3] Btrfs-progs: move path modification to filters
> 
> Commit 8e8e019e910f20947fea7eff5da40753639d8870 introduces -a option
> which will list all subvolumes with distinguishing between relative and
> absolute by prepending absolute patch with "<FS_TREE>".
> 
> This commit moves the path modification to a filter code rather than
> doing so in path construction in resolve_root(). This gives us more
> flexibility in formatting path output.

ping

any comments on this ?

-Lukas

> 
> Signed-off-by: Lukas Czerner <lczerner@redhat.com>
> ---
>  btrfs-list.c     |   32 +++++++++++++++++++++++---------
>  btrfs-list.h     |    1 +
>  cmds-subvolume.c |   11 +++++++++--
>  man/btrfs.8.in   |    3 ++-
>  4 files changed, 35 insertions(+), 12 deletions(-)
> 
> diff --git a/btrfs-list.c b/btrfs-list.c
> index e5f0f96..77d99f8 100644
> --- a/btrfs-list.c
> +++ b/btrfs-list.c
> @@ -628,15 +628,6 @@ static int resolve_root(struct root_lookup *rl, struct root_info *ri,
>  		}
>  
>  		if (next == BTRFS_FS_TREE_OBJECTID) {
> -			char p[] = "<FS_TREE>";
> -			add_len = strlen(p);
> -			len = strlen(full_path);
> -			tmp = malloc(len + add_len + 2);
> -			memcpy(tmp + add_len + 1, full_path, len);
> -			tmp[add_len] = '/';
> -			memcpy(tmp, p, add_len);
> -			free(full_path);
> -			full_path = tmp;
>  			ri->top_id = next;
>  			break;
>  		}
> @@ -1176,6 +1167,28 @@ static int filter_topid_equal(struct root_info *ri, u64 data)
>  	return ri->top_id == data;
>  }
>  
> +static int filter_full_path(struct root_info *ri, u64 data)
> +{
> +	if (ri->full_path && ri->top_id != data) {
> +		char *tmp;
> +		char p[] = "<FS_TREE>";
> +		int add_len = strlen(p);
> +		int len = strlen(ri->full_path);
> +
> +		tmp = malloc(len + add_len + 2);
> +		if (!tmp) {
> +			fprintf(stderr, "memory allocation failed\n");
> +			exit(1);
> +		}
> +		memcpy(tmp + add_len + 1, ri->full_path, len);
> +		tmp[add_len] = '/';
> +		memcpy(tmp, p, add_len);
> +		free(ri->full_path);
> +		ri->full_path = tmp;
> +	}
> +	return 1;
> +}
> +
>  static btrfs_list_filter_func all_filter_funcs[] = {
>  	[BTRFS_LIST_FILTER_ROOTID]		= filter_by_rootid,
>  	[BTRFS_LIST_FILTER_SNAPSHOT_ONLY]	= filter_snapshot,
> @@ -1187,6 +1200,7 @@ static btrfs_list_filter_func all_filter_funcs[] = {
>  	[BTRFS_LIST_FILTER_CGEN_LESS]		= filter_cgen_less,
>  	[BTRFS_LIST_FILTER_CGEN_EQUAL]          = filter_cgen_equal,
>  	[BTRFS_LIST_FILTER_TOPID_EQUAL]		= filter_topid_equal,
> +	[BTRFS_LIST_FILTER_FULL_PATH]		= filter_full_path,
>  };
>  
>  struct btrfs_list_filter_set *btrfs_list_alloc_filter_set(void)
> diff --git a/btrfs-list.h b/btrfs-list.h
> index cde4b3c..f7fbea6 100644
> --- a/btrfs-list.h
> +++ b/btrfs-list.h
> @@ -71,6 +71,7 @@ enum btrfs_list_filter_enum {
>  	BTRFS_LIST_FILTER_CGEN_LESS,
>  	BTRFS_LIST_FILTER_CGEN_MORE,
>  	BTRFS_LIST_FILTER_TOPID_EQUAL,
> +	BTRFS_LIST_FILTER_FULL_PATH,
>  	BTRFS_LIST_FILTER_MAX,
>  };
>  
> diff --git a/cmds-subvolume.c b/cmds-subvolume.c
> index ac39f7b..37cb8cc 100644
> --- a/cmds-subvolume.c
> +++ b/cmds-subvolume.c
> @@ -277,7 +277,9 @@ static const char * const cmd_subvol_list_usage[] = {
>  	"List subvolumes (and snapshots)",
>  	"",
>  	"-p           print parent ID",
> -	"-a           print all the subvolumes in the filesystem.",
> +	"-a           print all the subvolumes in the filesystem and",
> +	"             distinguish absolute and relative path with respect",
> +	"             to the given <path>",
>  	"-u           print the uuid of subvolumes (and snapshots)",
>  	"-t           print the result as a table",
>  	"-s           list snapshots only in the filesystem",
> @@ -400,7 +402,12 @@ static int cmd_subvol_list(int argc, char **argv)
>  	}
>  
>  	top_id = btrfs_list_get_path_rootid(fd);
> -	if (!is_list_all)
> +
> +	if (is_list_all)
> +		btrfs_list_setup_filter(&filter_set,
> +					BTRFS_LIST_FILTER_FULL_PATH,
> +					top_id);
> +	else
>  		btrfs_list_setup_filter(&filter_set,
>  					BTRFS_LIST_FILTER_TOPID_EQUAL,
>  					top_id);
> diff --git a/man/btrfs.8.in b/man/btrfs.8.in
> index 9222580..d6d8e94 100644
> --- a/man/btrfs.8.in
> +++ b/man/btrfs.8.in
> @@ -124,7 +124,8 @@ and top level. The parent's ID may be used at mount time via the
>  
>  \fB-t\fP print the result as a table.
>  
> -\fB-a\fP print all the subvolumes in the filesystem.
> +\fB-a\fP print all the subvolumes in the filesystem and distinguish between
> +absolute and relative path with respect to the given <path>.
>  
>  \fB-r\fP only readonly subvolumes in the filesystem wille be listed.
>  
>