btrfs-progs: fix error checking in load_device_info

load_device_info queries the FS_INFO ioctl and this may fail with EPERM
on older kernels. The check did not verify the ioctl return value and
incorrectly returned EPERM if it was previously stored in errno.

This fixes 'btrfs fi usage' that will print the overall summary for all
users (provided that the FS_INFO ioctl is already unprivileged).

Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
David Sterba 2015-10-02 17:44:21 +02:00
parent 1491d246c4
commit 49ac9aa1e8
1 changed files with 4 additions and 5 deletions

View File

@ -504,7 +504,7 @@ 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, e;
int ret, i, ndevs;
struct btrfs_ioctl_fs_info_args fi_args;
struct btrfs_ioctl_dev_info_args dev_info;
struct device_info *info;
@ -513,12 +513,11 @@ 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);
e = errno;
if (e == EPERM)
return -e;
if (ret < 0) {
if (errno == EPERM)
return -errno;
fprintf(stderr, "ERROR: cannot get filesystem info - %s\n",
strerror(e));
strerror(errno));
return 1;
}