btrfs-progs: fix error returns in get_df()

get_df returns -ERRNO, or maybe (+)errno, or even 0 in
the case where we inexplicably got 0 total_spaces from
the BTRFS_IOC_SPACE_INFO.

Consistently return a negative error number, and return
-ENOENT rather than 0 for total_spaces == 0, so that the
caller will know that **sargs_ret hasn't been set up.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

1 files changed, 4 insertions, 3 deletions

diff --git a/cmds-filesystem.c b/cmds-filesystem.c
index eb9b5e4f..e920b8a3 100644
--- a/cmds-filesystem.c
+++ b/cmds-filesystem.c
@@ -106,11 +106,12 @@ static int get_df(int fd, struct btrfs_ioctl_space_args **sargs_ret)
 		fprintf(stderr, "ERROR: couldn't get space info - %s\n",
 			strerror(e));
 		free(sargs);
-		return ret;
+		return -e;
 	}
+	/* This really should never happen */
 	if (!sargs->total_spaces) {
 		free(sargs);
-		return 0;
+		return -ENOENT;
 	}
 	count = sargs->total_spaces;
 	free(sargs);
@@ -128,7 +129,7 @@ static int get_df(int fd, struct btrfs_ioctl_space_args **sargs_ret)
 		fprintf(stderr, "ERROR: get space info count %llu - %s\n",
 				count, strerror(e));
 		free(sargs);
-		return ret;
+		return -e;
 	}
 	*sargs_ret = sargs;
 	return 0;