btrfs-progs: qgroup: use btrfs_open_dir for btrfs qgroup command

We can use btrfs_open_dir() to check whether target dir is
in btrfs's mount point before open, instead of checking it in
kernel space of ioctl, and return fuzzy error message.

Before patch:
  # ./btrfs qgroup create 1/5  /mnt/tmp1
  ERROR: unable to create quota group: Inappropriate ioctl for device
  #
  # ./btrfs qgroup assign 1/5 2/5 /mnt/tmp1
  ERROR: unable to assign quota group: Inappropriate ioctl for device
  #
  # ./btrfs qgroup show /mnt/tmp1
  ERROR: can't perform the search - Inappropriate ioctl for device
  ERROR: can't list qgroups: Inappropriate ioctl for device
  #
  # ./btrfs qgroup limit 1G 1/5  /mnt/tmp1
  ERROR: unable to limit requested quota group: Inappropriate ioctl for device

After patch:
  # ./btrfs qgroup create 1/5 /mnt/tmp1
  ERROR: not a btrfs filesystem: /mnt/tmp1
  # ./btrfs qgroup assign 1/5 2/5 /mnt/tmp1
  ERROR: not a btrfs filesystem: /mnt/tmp1
  # ./btrfs qgroup show /mnt/tmp1
  ERROR: not a btrfs filesystem: /mnt/tmp1
  # ./btrfs qgroup limit 1G 1/5 /mnt/tmp1
  ERROR: not a btrfs filesystem: /mnt/tmp1

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/cmds-qgroup.c b/cmds-qgroup.c
index 48c1733..0ad99f4 100644 (file)
--- a/cmds-qgroup.c
+++ b/cmds-qgroup.c
@@ -79,11 +79,9 @@ static int qgroup_assign(int assign, int argc, char **argv)
                fprintf(stderr, "ERROR: bad relation requested '%s'\n", path);
                return 1;
        }
-       fd = open_file_or_dir(path, &dirstream);
-       if (fd < 0) {
-               fprintf(stderr, "ERROR: can't access '%s'\n", path);
+       fd = btrfs_open_dir(path, &dirstream, 1);
+       if (fd < 0)
                return 1;
-       }
 
        ret = ioctl(fd, BTRFS_IOC_QGROUP_ASSIGN, &args);
        e = errno;
@@ -137,11 +135,9 @@ static int qgroup_create(int create, int argc, char **argv)
        args.create = create;
        args.qgroupid = parse_qgroupid(argv[1]);
 
-       fd = open_file_or_dir(path, &dirstream);
-       if (fd < 0) {
-               fprintf(stderr, "ERROR: can't access '%s'\n", path);
+       fd = btrfs_open_dir(path, &dirstream, 1);
+       if (fd < 0)
                return 1;
-       }
 
        ret = ioctl(fd, BTRFS_IOC_QGROUP_CREATE, &args);
        e = errno;
@@ -351,11 +347,9 @@ static int cmd_qgroup_show(int argc, char **argv)
                usage(cmd_qgroup_show_usage);
 
        path = argv[optind];
-       fd = open_file_or_dir(path, &dirstream);
-       if (fd < 0) {
-               fprintf(stderr, "ERROR: can't access '%s'\n", path);
+       fd = btrfs_open_dir(path, &dirstream, 1);
+       if (fd < 0)
                return 1;
-       }
 
        if (filter_flag) {
                qgroupid = btrfs_get_path_rootid(fd);
@@ -460,11 +454,9 @@ static int cmd_qgroup_limit(int argc, char **argv)
        } else
                usage(cmd_qgroup_limit_usage);
 
-       fd = open_file_or_dir(path, &dirstream);
-       if (fd < 0) {
-               fprintf(stderr, "ERROR: can't access '%s'\n", path);
+       fd = btrfs_open_dir(path, &dirstream, 1);
+       if (fd < 0)
                return 1;
-       }
 
        ret = ioctl(fd, BTRFS_IOC_QGROUP_LIMIT, &args);
        e = errno;