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>

1 files changed, 6 insertions, 2 deletions

diff --git a/fs/ceph/ioctl.c b/fs/ceph/ioctl.c
index 1396ceb4679..36549a46e31 100644
--- 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);