libceph: allow addrvecs with a single NONE/blank address

Normally, an unused OSD id/slot is represented by an empty addrvec.
However, it also appears to be possible to generate an osdmap where
an unused OSD id/slot has an addrvec with a single blank address of
type NONE.  Allow such addrvecs and make the end result be exactly
the same as for the empty addrvec case -- leave addr intact.

Cc: stable@vger.kernel.org # 5.11+
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>

diff --git a/net/ceph/decode.c b/net/ceph/decode.c
index b44f765..bc109a1 100644 (file)
--- a/net/ceph/decode.c
+++ b/net/ceph/decode.c
@@ -4,6 +4,7 @@
 #include <linux/inet.h>
 
 #include <linux/ceph/decode.h>
+#include <linux/ceph/messenger.h>  /* for ceph_pr_addr() */
 
 static int
 ceph_decode_entity_addr_versioned(void **p, void *end,
@@ -110,6 +111,7 @@ int ceph_decode_entity_addrvec(void **p, void *end, bool msgr2,
        }
 
        ceph_decode_32_safe(p, end, addr_cnt, e_inval);
+       dout("%s addr_cnt %d\n", __func__, addr_cnt);
 
        found = false;
        for (i = 0; i < addr_cnt; i++) {
@@ -117,6 +119,7 @@ int ceph_decode_entity_addrvec(void **p, void *end, bool msgr2,
                if (ret)
                        return ret;
 
+               dout("%s i %d addr %s\n", __func__, i, ceph_pr_addr(&tmp_addr));
                if (tmp_addr.type == my_type) {
                        if (found) {
                                pr_err("another match of type %d in addrvec\n",
@@ -128,13 +131,18 @@ int ceph_decode_entity_addrvec(void **p, void *end, bool msgr2,
                        found = true;
                }
        }
-       if (!found && addr_cnt != 0) {
-               pr_err("no match of type %d in addrvec\n",
-                      le32_to_cpu(my_type));
-               return -ENOENT;
-       }
 
-       return 0;
+       if (found)
+               return 0;
+
+       if (!addr_cnt)
+               return 0;  /* normal -- e.g. unused OSD id/slot */
+
+       if (addr_cnt == 1 && !memchr_inv(&tmp_addr, 0, sizeof(tmp_addr)))
+               return 0;  /* weird but effectively the same as !addr_cnt */
+
+       pr_err("no match of type %d in addrvec\n", le32_to_cpu(my_type));
+       return -ENOENT;
 
 e_inval:
        return -EINVAL;