Signed-off-by: Hubert Kario <kario@wit.edu.pl> --- cmds-device.c | 42 ++++++++++++++++++++++++++++++++++++++++++ man/btrfs.8.in | 7 +++++++ 2 files changed, 49 insertions(+) diff --git a/cmds-device.c b/cmds-device.c index db625a6..1edb091 100644 --- a/cmds-device.c +++ b/cmds-device.c @@ -246,11 +246,53 @@ static int cmd_scan_dev(int argc, char **argv) return 0; } +static const char * const cmd_zero_dev_usage[] = { + "btrfs device zero-superblock <device> [<device> ...]", + "Remove btrfs filesystem superblock from devices.", + "WARNING! This command will make filesystem residing on the devices", + "completely unmountable!", + NULL +}; + +static int cmd_zero_dev(int argc, char **argv) +{ + int fd; + char *file; + int arg_processed; + int ret = 0; + u64 device_len; + int mixed_mode_needed; + const int ZERO_END = 1; + + if( argc < 2 ) { + usage(cmd_zero_dev_usage); + } + + for(arg_processed = 1; arg_processed < argc; arg_processed++) { + file = argv[arg_processed]; + + fd = open(file, O_RDWR); + if (fd < 0) { + fprintf(stderr, "Unable to open %s\n", file); + ret |= 1; + continue; + } + + ret |= btrfs_prepare_device(fd, file, ZERO_END, &device_len, + &mixed_mode_needed); + + close(fd); + } + + return ret; +} + const struct cmd_group device_cmd_group = { device_cmd_group_usage, NULL, { { "add", cmd_add_dev, cmd_add_dev_usage, NULL, 0 }, { "delete", cmd_rm_dev, cmd_rm_dev_usage, NULL, 0 }, { "scan", cmd_scan_dev, cmd_scan_dev_usage, NULL, 0 }, + { "zero-superblock", cmd_zero_dev, cmd_zero_dev_usage, NULL, 0 }, { 0, 0, 0, 0, 0 } } }; diff --git a/man/btrfs.8.in b/man/btrfs.8.in index be478e0..a840f7e 100644 --- a/man/btrfs.8.in +++ b/man/btrfs.8.in @@ -39,6 +39,8 @@ btrfs \- control a btrfs filesystem .PP \fBbtrfs\fP \fBdevice delete\fP\fI <device> [<device>...] <path> \fP .PP +\fBbtrfs\fP \fBdevice zero-superblock\fP\fI <device> [<device>...] \fP +.PP \fBbtrfs\fP \fBscrub start\fP [-Bdqru] {\fI<path>\fP|\fI<device>\fP} .PP \fBbtrfs\fP \fBscrub cancel\fP {\fI<path>\fP|\fI<device>\fP} @@ -230,6 +232,11 @@ Finally, if \fB--all-devices\fP is passed, all the devices under /dev are scanned. .TP +\fBdevice zero-superblock\fR\fI <dev> [<dev>..]\fR +The space on the disk where btrfs metadata can reside is overwritten with +zeros. +.TP + \fBscrub start\fP [-Bdqru] {\fI<path>\fP|\fI<device>\fP} Start a scrub on all devices of the filesystem identified by \fI<path>\fR or on a single \fI<device>\fR. Without options, scrub is started as a background -- 1.7.10 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html