add mounted-checking for btrfs-vol

Adding a mounted device is dangerous because it will destroy the filesystem
on that mounted device. So we add mounted-checking for btrfs-vol.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>

diff --git a/btrfs-vol.c b/btrfs-vol.c
index 8069778..4ed799d 100644 (file)
--- a/btrfs-vol.c
+++ b/btrfs-vol.c
@@ -108,10 +108,24 @@ int main(int ac, char **av)
        if (device && strcmp(device, "missing") == 0 &&
            cmd == BTRFS_IOC_RM_DEV) {
                fprintf(stderr, "removing missing devices from %s\n", mnt);
-       } else if (device) {
+       } else if (cmd != BTRFS_IOC_BALANCE) {
+               if (cmd == BTRFS_IOC_ADD_DEV) {
+                       ret = check_mounted(device);
+                       if (ret < 0) {
+                               fprintf(stderr,
+                                       "error checking %s mount status\n",
+                                       device);
+                               exit(1);
+                       }
+                       if (ret == 1) {
+                               fprintf(stderr, "%s is mounted\n", device);
+                               exit(1);
+                       }
+               }
                devfd = open(device, O_RDWR);
-               if (!devfd) {
+               if (devfd < 0) {
                        fprintf(stderr, "Unable to open device %s\n", device);
+                       exit(1);
                }
                ret = fstat(devfd, &st);
                if (ret) {