Re: [PATCH 2/2] btrfs-progs: Add -p/--print-missing options for btrfs fi show

[Anand Jain <Anand.Jain@oracle.com>]

  Whats needed is more comprehensive btrfs fi show
  which shows the flags (including missing) per disk.
  And also show the FS/Raid status. Which I am working on.

  sorry -p feature would be covered by default in the
  coming revamp of btrfs fi show.

Thanks, Anand


On 02/07/2014 02:46 PM, Qu Wenruo wrote:
> Since a mounted btrfs filesystem contains all the devices info even a
> device is removed after mount(like btrfs/003 in xfstests),
> we can use the info to print the known missing device if possible.
>
> So -p/--print-missing options are added to print possible missing
> devices.
>
> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
> ---
>   cmds-filesystem.c | 26 ++++++++++++++++++++------
>   man/btrfs.8.in    |  4 +++-
>   2 files changed, 23 insertions(+), 7 deletions(-)
>
> diff --git a/cmds-filesystem.c b/cmds-filesystem.c
> index 4c9933d..77b142c 100644
> --- a/cmds-filesystem.c
> +++ b/cmds-filesystem.c
> @@ -360,7 +360,7 @@ static u64 calc_used_bytes(struct btrfs_ioctl_space_args *si)
>   static int print_one_fs(struct btrfs_ioctl_fs_info_args *fs_info,
>   		struct btrfs_ioctl_dev_info_args *dev_info,
>   		struct btrfs_ioctl_space_args *space_info,
> -		char *label, char *path)
> +		char *label, char *path, int print_missing)
>   {
>   	int i;
>   	int fd;
> @@ -392,7 +392,14 @@ static int print_one_fs(struct btrfs_ioctl_fs_info_args *fs_info,
>   		fd = open((char *)tmp_dev_info->path, O_RDONLY);
>   		if (fd < 0) {
>   			missing = 1;
> -			continue;
> +			if (print_missing)
> +				printf("\tdevid %4llu size %s used %s path %s (missing)\n",
> +				       tmp_dev_info->devid,
> +				       pretty_size(tmp_dev_info->total_bytes),
> +				       pretty_size(tmp_dev_info->bytes_used),
> +				       tmp_dev_info->path);
> +			else
> +				continue;
>   		}
>   		close(fd);
>   		printf("\tdevid %4llu size %s used %s path %s\n",
> @@ -440,7 +447,7 @@ static int check_arg_type(char *input)
>   	return BTRFS_ARG_UNKNOWN;
>   }
>
> -static int btrfs_scan_kernel(void *search)
> +static int btrfs_scan_kernel(void *search, int print_missing)
>   {
>   	int ret = 0, fd;
>   	FILE *f;
> @@ -477,7 +484,8 @@ static int btrfs_scan_kernel(void *search)
>   		fd = open(mnt->mnt_dir, O_RDONLY);
>   		if ((fd != -1) && !get_df(fd, &space_info_arg)) {
>   			print_one_fs(&fs_info_arg, dev_info_arg,
> -					space_info_arg, label, mnt->mnt_dir);
> +				     space_info_arg, label, mnt->mnt_dir,
> +				     print_missing);
>   			kfree(space_info_arg);
>   			memset(label, 0, sizeof(label));
>   		}
> @@ -500,6 +508,7 @@ static const char * const cmd_show_usage[] = {
>   	"Show the structure of a filesystem",
>   	"-d|--all-devices   show only disks under /dev containing btrfs filesystem",
>   	"-m|--mounted       show only mounted btrfs",
> +	"-p|--print-missing show known missing device if possible",
>   	"If no argument is given, structure of all present filesystems is shown.",
>   	NULL
>   };
> @@ -513,6 +522,7 @@ static int cmd_show(int argc, char **argv)
>   	int ret;
>   	int where = BTRFS_SCAN_LBLKID;
>   	int type = 0;
> +	int print_missing = 0;
>   	char mp[BTRFS_PATH_NAME_MAX + 1];
>   	char path[PATH_MAX];
>
> @@ -521,9 +531,10 @@ static int cmd_show(int argc, char **argv)
>   		static struct option long_options[] = {
>   			{ "all-devices", no_argument, NULL, 'd'},
>   			{ "mounted", no_argument, NULL, 'm'},
> +			{ "print-missing", no_argument, NULL, 'p'},
>   			{ NULL, no_argument, NULL, 0 },
>   		};
> -		int c = getopt_long(argc, argv, "dm", long_options,
> +		int c = getopt_long(argc, argv, "dmp", long_options,
>   					&long_index);
>   		if (c < 0)
>   			break;
> @@ -534,6 +545,9 @@ static int cmd_show(int argc, char **argv)
>   		case 'm':
>   			where = BTRFS_SCAN_MOUNTED;
>   			break;
> +		case 'p':
> +			print_missing = 1;
> +			break;
>   		default:
>   			usage(cmd_show_usage);
>   		}
> @@ -571,7 +585,7 @@ static int cmd_show(int argc, char **argv)
>   		goto devs_only;
>
>   	/* show mounted btrfs */
> -	ret = btrfs_scan_kernel(search);
> +	ret = btrfs_scan_kernel(search, print_missing);
>   	if (search && !ret)
>   		return 0;
>
> diff --git a/man/btrfs.8.in b/man/btrfs.8.in
> index 8fea115..db2e355 100644
> --- a/man/btrfs.8.in
> +++ b/man/btrfs.8.in
> @@ -25,7 +25,7 @@ btrfs \- control a btrfs filesystem
>   .PP
>   \fBbtrfs\fP \fBfilesystem df\fP\fI <path>\fP
>   .PP
> -\fBbtrfs\fP \fBfilesystem show\fP [\fI--mounted\fP|\fI--all-devices\fP|\fI<uuid>\fP]\fP
> +\fBbtrfs\fP \fBfilesystem show\fP [\fI--mounted\fP|\fI--all-devices\fP|\fI--print-missing\fP|\fI<uuid>\fP]\fP
>   .PP
>   \fBbtrfs\fP \fBfilesystem sync\fP\fI <path> \fP
>   .PP
> @@ -280,6 +280,8 @@ and unmounted.
>   If \fB--mounted\fP is passed, it would probe btrfs kernel to list mounted btrfs filesystem(s);
>   If \fB--all-devices\fP is passed, all the devices under /dev are scanned;
>   otherwise the devices list is extracted from the /proc/partitions file.
> +If \fB--print-missing\fP is passed, btrfs will try its best to print the missing device.
> +This option is only useful if the filesystem is already mounted since mounted filesystem may contain the device list.
>   .TP
>
>   \fBfilesystem sync\fR\fI <path> \fR
>