btrfs-progs: check if we can't get info from ioctls due to permissions

The TREE_SEARCH ioctl is root-only, FS_INFO will be available for
non-root users with an updated kernel, let the user know.

Signed-off-by: David Sterba <dsterba@suse.cz>

diff --git a/cmds-fi-disk_usage.c b/cmds-fi-disk_usage.c
index f432fa5..8bc4f58 100644 (file)
--- a/cmds-fi-disk_usage.c
+++ b/cmds-fi-disk_usage.c
@@ -172,6 +172,12 @@ int load_chunk_info(int fd, struct chunk_info **info_ptr, int *info_count)
        while (1) {
                ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args);
                e = errno;
+               if (ret == -EPERM) {
+                       fprintf(stderr,
+                               "ERROR: can't read detailed chunk info from ioctl(TREE_SEARCH), run as root\n");
+                       return 0;
+               }
+
                if (ret < 0) {
                        fprintf(stderr,
                                "ERROR: can't perform the search - %s\n",
@@ -461,6 +467,10 @@ int load_device_info(int fd, struct device_info **device_info_ptr,
        *device_info_ptr = 0;
 
        ret = ioctl(fd, BTRFS_IOC_FS_INFO, &fi_args);
+       if (ret == -EPERM) {
+               fprintf(stderr, "ERROR: can't get filesystem info from ioctl(FS_INFO), run as root\n");
+               return -1;
+       }
        if (ret < 0) {
                fprintf(stderr, "ERROR: cannot get filesystem info\n");
                return -1;