btrfs-progs: judge the return value of check_mounted more accurately

For btrfs-convert, btrfstune, btrfs rescue, they report "device busy"
when given a device that does not actually exist e.g.

	# btrfstune -x abcdefg (this device does not exist)
	$ ...device busy...

We deal with this case by add "ret < 0" error check when
judging the return value of check_mounted.

Signed-off-by: Gui Hecheng <guihc.fnst@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>

diff --git a/btrfs-convert.c b/btrfs-convert.c
index 1b66de7..a8b2c51 100644 (file)
--- a/btrfs-convert.c
+++ b/btrfs-convert.c
@@ -2729,7 +2729,12 @@ int main(int argc, char *argv[])
        }
 
        file = argv[optind];
-       if (check_mounted(file)) {
+       ret = check_mounted(file);
+       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", file);
                return 1;
        }

diff --git a/btrfstune.c b/btrfstune.c
index 855427f..2c26fe9 100644 (file)
--- a/btrfstune.c
+++ b/btrfstune.c
@@ -151,7 +151,12 @@ 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;
        }

diff --git a/cmds-rescue.c b/cmds-rescue.c
index e18eb98..f20a206 100644 (file)
--- a/cmds-rescue.c
+++ b/cmds-rescue.c
@@ -80,9 +80,13 @@ int cmd_chunk_recover(int argc, char *argv[])
        file = argv[optind];
 
        ret = check_mounted(file);
-       if (ret) {
+       if (ret < 0) {
+               fprintf(stderr, "Could not check mount status: %s\n",
+                       strerror(-ret));
+               return 1;
+       } else if (ret) {
                fprintf(stderr, "the device is busy\n");
-               return ret;
+               return 1;
        }
 
        ret = btrfs_recover_chunk_tree(file, verbose, yes);
@@ -133,7 +137,11 @@ int cmd_super_recover(int argc, char **argv)
 
        dname = argv[optind];
        ret = check_mounted(dname);
-       if (ret) {
+       if (ret < 0) {
+               fprintf(stderr, "Could not check mount status: %s\n",
+                       strerror(-ret));
+               return 1;
+       } else if (ret) {
                fprintf(stderr, "the device is busy\n");
                return 1;
        }