btrfs-progs: fix improper output msg for btrfs-fi-usage

Even if run as root:
	# su
	# btrfs file usage <path> <== path exits outside the mnt point
We get the output:
	WARNING: ..., run as root
	WARNING: ..., run as root
	ERROR:...

It is because in load_chunk_info, the errno of ioctl is not judged
but rather the ret value of ioctl is judged. And the ret value of
ioctl is -1 which happens to match -EPERM exactly.
So the outer warning is printed.

Just judge the errno of ioctl and prevent the ret value of load_chunk_info
to be -1 in other error conditions.

For load_device_info, the problem and fix is the same.
After the fix, the 'run as root' WARNINGs will not show up in this condition.

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

diff --git a/cmds-fi-disk_usage.c b/cmds-fi-disk_usage.c
index 6caa282..d95024f 100644 (file)
--- a/cmds-fi-disk_usage.c
+++ b/cmds-fi-disk_usage.c
@@ -156,14 +156,14 @@ static 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)
-                       return ret;
+               if (e == EPERM)
+                       return -e;
 
                if (ret < 0) {
                        fprintf(stderr,
                                "ERROR: can't perform the search - %s\n",
                                strerror(e));
-                       return ret;
+                       return 1;
                }
                /* the ioctl returns the number of item it found in nr_items */
 
@@ -182,7 +182,7 @@ static int load_chunk_info(int fd, struct chunk_info **info_ptr, int *info_count
                        ret = add_info_to_list(info_ptr, info_count, item);
                        if (ret) {
                                *info_ptr = 0;
-                               return ret;
+                               return 1;
                        }
 
                        off += sh->len;
@@ -442,7 +442,7 @@ static int cmp_device_info(const void *a, const void *b)
 static int load_device_info(int fd, struct device_info **device_info_ptr,
                           int *device_info_count)
 {
-       int ret, i, ndevs;
+       int ret, i, ndevs, e;
        struct btrfs_ioctl_fs_info_args fi_args;
        struct btrfs_ioctl_dev_info_args dev_info;
        struct device_info *info;
@@ -451,17 +451,19 @@ static 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)
-               return ret;
+       e = errno;
+       if (e == EPERM)
+               return -e;
        if (ret < 0) {
-               fprintf(stderr, "ERROR: cannot get filesystem info\n");
-               return ret;
+               fprintf(stderr, "ERROR: cannot get filesystem info - %s\n",
+                               strerror(e));
+               return 1;
        }
 
        info = calloc(fi_args.num_devices, sizeof(struct device_info));
        if (!info) {
                fprintf(stderr, "ERROR: not enough memory\n");
-               return ret;
+               return 1;
        }
 
        for (i = 0, ndevs = 0 ; i <= fi_args.max_id ; i++) {