Re: [f2fs-dev] [PATCH v2] tools: Introduce f2fslabel

[Chao Yu <chao@kernel.org>]

On 2021/5/12 17:08, Dongwoo Lee wrote:
> Although many other filesystems provide a tool for changing volume
> label, e.g. e2label for ext filesystem, but f2fs has no way to change
> volume label except set it while formatting with mkfs.f2fs.
> 
> This introduces f2fslabel, simple tool for changing label of f2fs
> volume.
> 
> Signed-off-by: Dongwoo Lee <dwoo08.lee@samsung.com>
> ---
> 
> Changes in v2:
> - Integrated into fsck/main.c instead of individual tool
> 
>   fsck/Makefile.am  |  1 +
>   fsck/main.c       | 79 +++++++++++++++++++++++++++++++++++++++++++++++
>   include/f2fs_fs.h |  2 ++
>   man/Makefile.am   |  2 +-
>   man/f2fslabel.8   | 33 ++++++++++++++++++++
>   5 files changed, 116 insertions(+), 1 deletion(-)
>   create mode 100644 man/f2fslabel.8
> 
> diff --git a/fsck/Makefile.am b/fsck/Makefile.am
> index e7d599c..e31d416 100644
> --- a/fsck/Makefile.am
> +++ b/fsck/Makefile.am
> @@ -18,3 +18,4 @@ install-data-hook:
>   	ln -sf fsck.f2fs $(DESTDIR)/$(sbindir)/defrag.f2fs
>   	ln -sf fsck.f2fs $(DESTDIR)/$(sbindir)/resize.f2fs
>   	ln -sf fsck.f2fs $(DESTDIR)/$(sbindir)/sload.f2fs
> +	ln -sf fsck.f2fs $(DESTDIR)/$(sbindir)/f2fslabel
> diff --git a/fsck/main.c b/fsck/main.c
> index 64efa87..6a9668a 100644
> --- a/fsck/main.c
> +++ b/fsck/main.c
> @@ -155,6 +155,14 @@ void sload_usage()
>   	exit(1);
>   }
>   
> +void label_usage()
> +{
> +	MSG(0, "\nUsage: f2fslabel [options] device [volume-label]\n");
> +	MSG(0, "[options]:\n");
> +	MSG(0, "  -V print the version number and exit\n");
> +	exit(1);
> +}
> +
>   static int is_digits(char *optarg)
>   {
>   	unsigned int i;
> @@ -177,6 +185,8 @@ static void error_out(char *prog)
>   		resize_usage();
>   	else if (!strcmp("sload.f2fs", prog))
>   		sload_usage();
> +	else if (!strcmp("f2fslabel", prog))
> +		label_usage();
>   	else
>   		MSG(0, "\nWrong program.\n");
>   }
> @@ -722,6 +732,39 @@ void f2fs_parse_options(int argc, char *argv[])
>   			}
>   		}
>   #endif /* WITH_SLOAD */
> +	} else if (!strcmp("f2fslabel", prog)) {
> +#ifdef WITH_LABEL
> +		const char *option_string = "V";
> +
> +		c.func = LABEL;
> +		while ((option = getopt(argc, argv, option_string)) != EOF) {
> +			switch (option) {
> +			case 'V':
> +				show_version(prog);
> +				exit(0);
> +			default:
> +				err = EUNKNOWN_OPT;
> +				break;
> +			}
> +			if (err != NOERROR)
> +				break;
> +		}
> +
> +		if (argc > (optind + 2)) { /* unknown argument(s) is(are) passed */
> +			optind += 2;
> +			err = EUNKNOWN_ARG;
> +		} else if (argc == (optind + 2)) { /* change label */
> +			c.vol_label = strdup(argv[optind + 1]);
> +			argc--;
> +		} else { /* print label */
> +			/*
> +			 * Since vol_label was initialized as "", in order to
> +			 * distinguish between clear label and print, set
> +			 * vol_label as NULL for print case
> +			 */
> +			c.vol_label = NULL;
> +		}
> +#endif /* WITH_LABEL */
>   	}
>   
>   	if (err == NOERROR) {
> @@ -971,6 +1014,36 @@ static int do_sload(struct f2fs_sb_info *sbi)
>   }
>   #endif
>   
> +#ifdef WITH_LABEL
> +static int do_label(struct f2fs_sb_info *sbi)
> +{
> +	struct f2fs_super_block *sb = F2FS_RAW_SUPER(sbi);
> +
> +	if (!c.vol_label) {
> +		char label[MAX_VOLUME_NAME];
> +
> +		utf16_to_utf8(label, sb->volume_name,
> +			      MAX_VOLUME_NAME, MAX_VOLUME_NAME);
> +		MSG(0, "Info: volume label = %s\n", label);
> +		return 0;
> +	}
> +
> +	if (strlen(c.vol_label) > MAX_VOLUME_NAME) {
> +		ERR_MSG("Label should not exceed %d characters\n", MAX_VOLUME_NAME);
> +		return -1;
> +	}
> +
> +	utf8_to_utf16(sb->volume_name, (const char *)c.vol_label,
> +		      MAX_VOLUME_NAME, strlen(c.vol_label));
> +
> +	update_superblock(sb, SB_MASK_ALL);
> +
> +	MSG(0, "Info: volume label is changed to %s\n", c.vol_label);

It needs to free c.vol_label here?

Thanks,

> +
> +	return 0;
> +}
> +#endif
> +
>   #if defined(__APPLE__)
>   static u64 get_boottime_ns()
>   {
> @@ -1084,6 +1157,12 @@ fsck_again:
>   		c.func = FSCK;
>   		c.fix_on = 1;
>   		goto fsck_again;
> +#endif
> +#ifdef WITH_LABEL
> +	case LABEL:
> +		if (do_label(sbi))
> +			goto out_err;
> +		break;
>   #endif
>   	default:
>   		ERR_MSG("Wrong program name\n");
> diff --git a/include/f2fs_fs.h b/include/f2fs_fs.h
> index cdcce2c..5d49ed1 100644
> --- a/include/f2fs_fs.h
> +++ b/include/f2fs_fs.h
> @@ -35,6 +35,7 @@
>   #define WITH_DEFRAG
>   #define WITH_RESIZE
>   #define WITH_SLOAD
> +#define WITH_LABEL
>   #endif
>   
>   #include <inttypes.h>
> @@ -343,6 +344,7 @@ enum f2fs_config_func {
>   	DEFRAG,
>   	RESIZE,
>   	SLOAD,
> +	LABEL,
>   };
>   
>   enum default_set {
> diff --git a/man/Makefile.am b/man/Makefile.am
> index 1d16c6f..9363b82 100644
> --- a/man/Makefile.am
> +++ b/man/Makefile.am
> @@ -1,3 +1,3 @@
>   ## Makefile.am
>   
> -dist_man_MANS = mkfs.f2fs.8 fsck.f2fs.8 dump.f2fs.8 defrag.f2fs.8 resize.f2fs.8 sload.f2fs.8 f2fs_io.8
> +dist_man_MANS = mkfs.f2fs.8 fsck.f2fs.8 dump.f2fs.8 defrag.f2fs.8 resize.f2fs.8 sload.f2fs.8 f2fs_io.8 f2fslabel.8
> diff --git a/man/f2fslabel.8 b/man/f2fslabel.8
> new file mode 100644
> index 0000000..848ed3b
> --- /dev/null
> +++ b/man/f2fslabel.8
> @@ -0,0 +1,33 @@
> +.\" Copyright (c) 2021 Samsung Electronics Co., Ltd.
> +.\"
> +.TH F2FSLABEL 8
> +.SH NAME
> +f2fslabel \- Change the label on an f2fs volume
> +.SH SYNOPSIS
> +.B f2fslabel
> +.I device
> +[
> +.I volume-label
> +]
> +.SH DESCRIPTION
> +.B f2fslabel
> +will display or change the volume label on the f2fs located on
> +.I device.
> +.PP
> +If the optional argument
> +.I volume-label
> +is present, then
> +.B f2fslabel
> +will set the volume label to be
> +.IR volume-label .
> +.PP
> +Otherwise,
> +.B f2fslabel
> +will simply show the current label.
> +.PP
> +.SH AUTHOR
> +.B f2fslabel
> +was written by Dongwoo Lee (dwoo08.lee@samsung.com).
> +.SH AVAILABILITY
> +.B f2fslabel
> +is available from git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs-tools.git.
> 


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