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>

2 files changed, 4 insertions, 4 deletions

diff --git a/include/linux/ceph/osd_client.h b/include/linux/ceph/osd_client.h
index cedfb1a8434a..d9b880e977e6 100644
--- a/include/linux/ceph/osd_client.h
+++ b/include/linux/ceph/osd_client.h
@@ -207,7 +207,7 @@ extern void ceph_osdc_handle_reply(struct ceph_osd_client *osdc,
 extern void ceph_osdc_handle_map(struct ceph_osd_client *osdc,
                                  struct ceph_msg *msg);
 
-extern void ceph_calc_raw_layout(struct ceph_osd_client *osdc,
+extern int ceph_calc_raw_layout(struct ceph_osd_client *osdc,
                         struct ceph_file_layout *layout,
                         u64 snapid,
                         u64 off, u64 *plen, u64 *bno,
diff --git a/include/linux/ceph/osdmap.h b/include/linux/ceph/osdmap.h
index 311ef8d6aa9e..e88a620b9f8a 100644
--- a/include/linux/ceph/osdmap.h
+++ b/include/linux/ceph/osdmap.h
@@ -109,9 +109,9 @@ extern struct ceph_osdmap *osdmap_apply_incremental(void **p, void *end,
 extern void ceph_osdmap_destroy(struct ceph_osdmap *map);
 
 /* calculate mapping of a file extent to an object */
-extern void ceph_calc_file_object_mapping(struct ceph_file_layout *layout,
-                                          u64 off, u64 *plen,
-                                          u64 *bno, u64 *oxoff, u64 *oxlen);
+extern int ceph_calc_file_object_mapping(struct ceph_file_layout *layout,
+                                         u64 off, u64 *plen,
+                                         u64 *bno, u64 *oxoff, u64 *oxlen);
 
 /* calculate mapping of object to a placement group */
 extern int ceph_calc_object_layout(struct ceph_object_layout *ol,