On Thu, Mar 21, 2013 at 07:56:44PM +0800, Anand Jain wrote:
> We should avoid using non multi-path (mp) path for mp disks
> As of now there is no good way (like api) to check that.
> A workaround way is to check if the O_EXCL open is unsuccessful.
> This is safe since otherwise the BTRFS_IOC_SCAN_DEV ioctl would
> fail if the disk-path can not be opened with the flag O_EXCL set.
Agreed. Alternatively we could try to parse the /sys entries.
> --- a/cmds-device.c
> +++ b/cmds-device.c
> @@ -185,7 +185,7 @@ static const char * const cmd_scan_dev_usage[] = {
>
> static int cmd_scan_dev(int argc, char **argv)
> {
> - int i, fd, e;
> + int i, fd, e, ret = 0;
> int checklist = 1;
> int devstart = 1;
>
> @@ -197,6 +197,21 @@ static int cmd_scan_dev(int argc, char **argv)
> devstart += 1;
> }
>
> + fd = open("/dev/btrfs-control", O_RDWR);
> + e = errno;
> + if (fd < 0) {
> + FILE *mfd = popen("lsmod | grep btrfs", "r");
Please transform this into C.
> + char buf[16];
> +
> + if (fread (buf, 1, sizeof (buf), mfd) > 0)
> + fprintf(stderr, "ERROR: failed to open "\
> + "/dev/btrfs-control - %s\n", strerror(e));
> + else
> + fprintf(stderr, "ERROR: btrfs kernel module "\
> + "is not loaded\n");
> + return 10;
We should not be using the old style of error codes in new code, other
paths in this functions return -1 .
> + }
thanks,
david
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