ceph: return EIO on invalid layout on GET_DATALOC ioctl

If the user calls GET_DATALOC on a file with an invalid (e.g.,
zeroed) layout, return EIO to userland.

Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>

diff --git a/fs/ceph/ioctl.c b/fs/ceph/ioctl.c
index 1396ceb..36549a4 100644 (file)
--- a/fs/ceph/ioctl.c
+++ b/fs/ceph/ioctl.c
@@ -187,14 +187,18 @@ static long ceph_ioctl_get_dataloc(struct file *file, void __user *arg)
        u64 tmp;
        struct ceph_object_layout ol;
        struct ceph_pg pgid;
+       int r;
 
        /* copy and validate */
        if (copy_from_user(&dl, arg, sizeof(dl)))
                return -EFAULT;
 
        down_read(&osdc->map_sem);
-       ceph_calc_file_object_mapping(&ci->i_layout, dl.file_offset, &len,
-                                     &dl.object_no, &dl.object_offset, &olen);
+       r = ceph_calc_file_object_mapping(&ci->i_layout, dl.file_offset, &len,
+                                         &dl.object_no, &dl.object_offset,
+                                         &olen);
+       if (r < 0)
+               return -EIO;
        dl.file_offset -= dl.object_offset;
        dl.object_size = ceph_file_layout_object_size(ci->i_layout);
        dl.block_size = ceph_file_layout_su(ci->i_layout);