ceph: avoid accessing freeing inode in ceph_check_delayed_caps()

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

1 files changed, 9 insertions, 2 deletions

diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index f5552455223f..7007ae2a5ad2 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -3809,6 +3809,7 @@ bad:
  */
 void ceph_check_delayed_caps(struct ceph_mds_client *mdsc)
 {
+        struct inode *inode;
         struct ceph_inode_info *ci;
         int flags = CHECK_CAPS_NODELAY;
 
@@ -3824,9 +3825,15 @@ void ceph_check_delayed_caps(struct ceph_mds_client *mdsc)
                     time_before(jiffies, ci->i_hold_caps_max))
                         break;
                 list_del_init(&ci->i_cap_delay_list);
+
+                inode = igrab(&ci->vfs_inode);
                 spin_unlock(&mdsc->cap_delay_lock);
-                dout("check_delayed_caps on %p\n", &ci->vfs_inode);
-                ceph_check_caps(ci, flags, NULL);
+
+                if (inode) {
+                        dout("check_delayed_caps on %p\n", inode);
+                        ceph_check_caps(ci, flags, NULL);
+                        iput(inode);
+                }
         }
         spin_unlock(&mdsc->cap_delay_lock);
 }