Re: [PATCH V2] btrfs-progs: Add ioctl to read compressed size of a file

[Goffredo Baroncelli <kreijack@inwind.it>]

Hi David

On Tuesday, 20 December, 2011 18:49:58 David Sterba wrote:
> Signed-off-by: David Sterba <dsterba@suse.cz>
> ---
> V1-V2:
> * match current kernel side and print uncompressed length as well
> * now it's easy to print the compression ratio for the given range
> 
>  btrfs.c      |    9 ++++++-
>  btrfs_cmds.c |   68
> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ btrfs_cmds.h |  
>  1 +
>  ioctl.h      |   13 +++++++++++

Please, update the man page too

>  4 files changed, 90 insertions(+), 1 deletions(-)
> 
> diff --git a/btrfs.c b/btrfs.c
> index 1def354..dbb7224 100644
> --- a/btrfs.c
> +++ b/btrfs.c
> @@ -128,7 +128,14 @@ static struct Command commands[] = {
>  	  "filesystem label", "<device> [<newlabel>]\n"
>  	  "With one argument, get the label of filesystem on <device>.\n"
>  	  "If <newlabel> is passed, set the filesystem label to <newlabel>.\n"
> -	  "The filesystem must be unmounted.\n"
> +	  "The filesystem must be unmounted."
> +	},
> +	{ do_compr_size, -1,
> +	  "filesystem csize", "[-s start] [-e end] file\n"
> +		  "Read ordinary and compressed size of extents in the range
> [start,end)\n" +		  "-s start  range start inclusive, accepts K/M/G
> modifiers\n"
> +		  "-e end    range end exclusive, accepts K/M/G modifiers\n",
> +	  NULL
>  	},
>  	{ do_scrub_start, -1,
>  	  "scrub start", "[-Bdqr] <path>|<device>\n"
> diff --git a/btrfs_cmds.c b/btrfs_cmds.c
> index b59e9cb..1074ade 100644
> --- a/btrfs_cmds.c
> +++ b/btrfs_cmds.c
> @@ -1305,3 +1305,71 @@ out:
>  	free(inodes);
>  	return ret;
>  }
> +
> +int do_compr_size(int argc, char **argv)
> +{
> +	int ret;
> +	int fd;
> +	struct btrfs_ioctl_compr_size_args args;
> +
> +	args.start = 0;
> +	args.end = (u64)-1;
> +	optind = 1;
> +	while (1) {
> +		int c = getopt(argc, argv, "s:e:r");
> +		if (c < 0)
> +			break;
> +		switch (c) {
> +		case 's':
> +			args.start = parse_size(optarg);
> +			break;
> +		case 'e':
> +			args.end = parse_size(optarg);
> +			break;
> +		default:
> +			fprintf(stderr, "ERROR: Invalid arguments for csize\n");
> +			return 1;
> +		}
> +	}
> +
> +	if (args.start > args.end) {
> +		fprintf(stderr, "ERROR: Invalid range for csize\n");
> +		return 1;
> +	}
> +
> +	if (argc - optind == 0) {
> +		fprintf(stderr, "ERROR: Invalid arguments for csize\n");
> +		return 1;
> +	}
> +	argc -= optind;
> +
> +	fd = open_file_or_dir(argv[optind]);
> +	if (fd < 0) {
> +		fprintf(stderr, "ERROR: can't access '%s'\n", argv[optind]);
> +		return 1;
> +	}
> +
> +	ret = ioctl(fd, BTRFS_IOC_COMPR_SIZE, &args);
> +	if (ret < 0) {
> +		fprintf(stderr, "ERROR: ioctl returned %d, errno %d %s\n",
> +				ret, errno, strerror(errno));
> +		return errno;
> +	}
> +
> +	printf("File name: %s\n", argv[optind]);
> +	if (args.end == (u64)-1)
> +		printf("File range:        %llu-EOF\n",
> +				(unsigned long long)args.start);
> +	else
> +		printf("File range:        %llu-%llu\n",
> +				(unsigned long long)args.start,
> +				(unsigned long long)args.end);
> +
> +	printf("Compressed size:   %llu\n",
> +			(unsigned long long)(args.compressed_size << 9));
> +	printf("Uncompressed size: %llu\n",
> +			(unsigned long long)(args.size << 9));
> +	printf("Ratio:             %3.2f%%\n",
> +			100.0 * args.compressed_size / args.size);
> +	return 0;
> +}
> diff --git a/btrfs_cmds.h b/btrfs_cmds.h
> index 81182b1..d171214 100644
> --- a/btrfs_cmds.h
> +++ b/btrfs_cmds.h
> @@ -42,3 +42,4 @@ int open_file_or_dir(const char *fname);
>  int do_ino_to_path(int nargs, char **argv);
>  int do_logical_to_ino(int nargs, char **argv);
>  char *path_for_root(int fd, u64 root);
> +int do_compr_size(int argc, char **argv);
> diff --git a/ioctl.h b/ioctl.h
> index 1ae7537..5b5208a 100644
> --- a/ioctl.h
> +++ b/ioctl.h
> @@ -224,6 +224,17 @@ struct btrfs_ioctl_logical_ino_args {
>  	__u64				inodes;
>  };
> 
> +struct btrfs_ioctl_compr_size_args {
> +	/* Range start, inclusive */
> +	__u64   start;                          /* in */
> +	/* Range end, exclusive */
> +	__u64   end;                            /* in */
> +	__u64   size;                           /* out */
> +	__u64   compressed_size;                /* out */
> +	__u64   reserved[2];
> +};
> +
> +
>  /* BTRFS_IOC_SNAP_CREATE is no longer used by the btrfs command */
>  #define BTRFS_IOC_SNAP_CREATE _IOW(BTRFS_IOCTL_MAGIC, 1, \
>  				   struct btrfs_ioctl_vol_args)
> @@ -277,5 +288,7 @@ struct btrfs_ioctl_logical_ino_args {
>  					struct btrfs_ioctl_ino_path_args)
>  #define BTRFS_IOC_LOGICAL_INO _IOWR(BTRFS_IOCTL_MAGIC, 36, \
>  					struct btrfs_ioctl_ino_path_args)
> +#define BTRFS_IOC_COMPR_SIZE _IOR(BTRFS_IOCTL_MAGIC, 51, \
> +		                struct btrfs_ioctl_compr_size_args)
> 
>  #endif
-- 
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