From: Xiubo Li <xiubli@redhat.com>
Date: Mon, 14 Nov 2022 10:11:39 +0000 (+0800)
Subject: mount: fix mount failure with old kernels
X-Git-Tag: v17.2.6~88^2
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=refs%2Fpull%2F49404%2Fhead;p=ceph.git

mount: fix mount failure with old kernels

If the 'cmi->cmi_opts' has only one option and there is no any
comma in it, when removing the 'mon_addr' it will fail. And will
pass the 'mon_addr' option to the old kernels.

Fixes: https://tracker.ceph.com/issues/58018
Signed-off-by: Xiubo Li <xiubli@redhat.com>
(cherry picked from commit 3180332ec48596794e2ff4fff305119c4ec2caf7)
---

diff --git a/src/mount/mount.ceph.c b/src/mount/mount.ceph.c
index 032c22e6c23f..ff1b12c474e5 100644
--- a/src/mount/mount.ceph.c
+++ b/src/mount/mount.ceph.c
@@ -164,7 +164,9 @@ static int remove_opt(struct ceph_mount_info *cmi, const char *key, char **value
 		memmove(key_start, value_end, len2);
 	} else {
                 /* last kv pair - swallow the comma */
-		--key_start;
+		if (*(key_start - 1) == ',') {
+			--key_start;
+		}
 		*key_start = '\0';
 	}