Btrfs-progs: check, fix return value check of is_child_root()

[platform/upstream/btrfs-progs.git] / btrfstune.c

diff --git a/btrfstune.c b/btrfstune.c
index 855427f..050418a 100644 (file)
--- a/btrfstune.c
+++ b/btrfstune.c
@@ -56,6 +56,7 @@ static int update_seeding_flag(struct btrfs_root *root, int set_flag)
                        return 1;
                }
                super_flags &= ~BTRFS_SUPER_FLAG_SEEDING;
+               fprintf(stderr, "Warning: Seeding flag cleared.\n");
        }
 
        trans = btrfs_start_transaction(root, 1);
@@ -100,9 +101,10 @@ static int enable_skinny_metadata(struct btrfs_root *root)
 static void print_usage(void)
 {
        fprintf(stderr, "usage: btrfstune [options] device\n");
-       fprintf(stderr, "\t-S value\tenable/disable seeding\n");
+       fprintf(stderr, "\t-S value\tpositive value will enable seeding, zero to disable, negative is not allowed\n");
        fprintf(stderr, "\t-r \t\tenable extended inode refs\n");
-       fprintf(stderr, "\t-x enable skinny metadata extent refs\n");
+       fprintf(stderr, "\t-x \t\tenable skinny metadata extent refs\n");
+       fprintf(stderr, "\t-f \t\tforce to clear flags, make sure that you are aware of the dangers\n");
 }
 
 int main(int argc, char *argv[])
@@ -113,11 +115,12 @@ int main(int argc, char *argv[])
        int seeding_flag = 0;
        u64 seeding_value = 0;
        int skinny_flag = 0;
+       int force = 0;
        int ret;
 
        optind = 1;
        while(1) {
-               int c = getopt(argc, argv, "S:rx");
+               int c = getopt(argc, argv, "S:rxf");
                if (c < 0)
                        break;
                switch(c) {
@@ -131,15 +134,19 @@ int main(int argc, char *argv[])
                case 'x':
                        skinny_flag = 1;
                        break;
+               case 'f':
+                       force = 1;
+                       break;
                default:
                        print_usage();
                        return 1;
                }
        }
 
+       set_argv0(argv);
        argc = argc - optind;
        device = argv[optind];
-       if (argc != 1) {
+       if (check_argc_exact(argc, 1)) {
                print_usage();
                return 1;
        }
@@ -151,7 +158,12 @@ int main(int argc, char *argv[])
                return 1;
        }
 
-       if (check_mounted(device)) {
+       ret = check_mounted(device);
+       if (ret < 0) {
+               fprintf(stderr, "Could not check mount status: %s\n",
+                       strerror(-ret));
+               return 1;
+       } else if (ret) {
                fprintf(stderr, "%s is mounted\n", device);
                return 1;
        }
@@ -164,6 +176,15 @@ int main(int argc, char *argv[])
        }
 
        if (seeding_flag) {
+               if (!seeding_value && !force) {
+                       fprintf(stderr, "Warning: This is dangerous, clearing the seeding flag may cause the derived device not to be mountable!\n");
+                       ret = ask_user("We are going to clear the seeding flag, are you sure?");
+                       if (!ret) {
+                               fprintf(stderr, "Clear seeding flag canceled\n");
+                               return 1;
+                       }
+               }
+
                ret = update_seeding_flag(root, seeding_value);
                if (!ret)
                        success++;