libceph: check for invalid mapping
If we encounter an invalid (e.g., zeroed) mapping, return an error
and avoid a divide by zero.
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
diff --git a/net/ceph/osdmap.c b/net/ceph/osdmap.c
index 3124b71..5433fb0 100644
--- a/net/ceph/osdmap.c
+++ b/net/ceph/osdmap.c
@@ -984,7 +984,7 @@
* for now, we write only a single su, until we can
* pass a stride back to the caller.
*/
-void ceph_calc_file_object_mapping(struct ceph_file_layout *layout,
+int ceph_calc_file_object_mapping(struct ceph_file_layout *layout,
u64 off, u64 *plen,
u64 *ono,
u64 *oxoff, u64 *oxlen)
@@ -998,11 +998,17 @@
dout("mapping %llu~%llu osize %u fl_su %u\n", off, *plen,
osize, su);
+ if (su == 0 || sc == 0)
+ goto invalid;
su_per_object = osize / su;
+ if (su_per_object == 0)
+ goto invalid;
dout("osize %u / su %u = su_per_object %u\n", osize, su,
su_per_object);
- BUG_ON((su & ~PAGE_MASK) != 0);
+ if ((su & ~PAGE_MASK) != 0)
+ goto invalid;
+
/* bl = *off / su; */
t = off;
do_div(t, su);
@@ -1030,6 +1036,14 @@
*plen = *oxlen;
dout(" obj extent %llu~%llu\n", *oxoff, *oxlen);
+ return 0;
+
+invalid:
+ dout(" invalid layout\n");
+ *ono = 0;
+ *oxoff = 0;
+ *oxlen = 0;
+ return -EINVAL;
}
EXPORT_SYMBOL(ceph_calc_file_object_mapping);