From: Chengguang Xu <cgxu519@icloud.com>
Date: Fri, 23 Feb 2018 09:09:38 +0000 (+0800)
Subject: ceph: adding protection for showing cap reservation info
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=b884014a91a49ed0e7198d276b28887cc48363bd;p=openwrt%2Fstaging%2Fblogic.git

ceph: adding protection for showing cap reservation info

Adding spinlock protection during getting cap reservation
ralated fields so that the numbers match below BUG_ON condition
in the code.

BUG_ON(mdsc->caps_total_count != mdsc->caps_use_count +
				 mdsc->caps_reserve_count +
				 mdsc->caps_avail_count);

Signed-off-by: Chengguang Xu <cgxu519@icloud.com>
Reviewed-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
---

diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index 0e5bd3e3344e..1d02648788e3 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -341,6 +341,8 @@ void ceph_reservation_status(struct ceph_fs_client *fsc,
 {
 	struct ceph_mds_client *mdsc = fsc->mdsc;
 
+	spin_lock(&mdsc->caps_list_lock);
+
 	if (total)
 		*total = mdsc->caps_total_count;
 	if (avail)
@@ -351,6 +353,8 @@ void ceph_reservation_status(struct ceph_fs_client *fsc,
 		*reserved = mdsc->caps_reserve_count;
 	if (min)
 		*min = mdsc->caps_min_count;
+
+	spin_unlock(&mdsc->caps_list_lock);
 }
 
 /*