afs: Clear AFS_VNODE_CB_PROMISED if we detect callback expiry

Fix afs_validate() to clear AFS_VNODE_CB_PROMISED on a vnode if we detect
any condition that causes the callback promise to be broken implicitly,
including server break (cb_s_break), volume break (cb_v_break) or callback
expiry.

Fixes: ae3b7361dc0e ("afs: Fix validation/callback interaction")
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>

1 files changed, 13 insertions, 1 deletions

diff --git a/fs/afs/inode.c b/fs/afs/inode.c
index ba35b4824408..37c5de793353 100644
--- a/fs/afs/inode.c
+++ b/fs/afs/inode.c
@@ -571,7 +571,7 @@ bool afs_check_validity(struct afs_vnode *vnode)
         struct afs_server *server;
         struct afs_volume *volume = vnode->volume;
         time64_t now = ktime_get_real_seconds();
-        bool valid;
+        bool valid, need_clear = false;
         unsigned int cb_break, cb_s_break, cb_v_break;
         int seq = 0;
 
@@ -589,10 +589,13 @@ bool afs_check_validity(struct afs_vnode *vnode)
                             vnode->cb_v_break != cb_v_break) {
                                 vnode->cb_s_break = cb_s_break;
                                 vnode->cb_v_break = cb_v_break;
+                                need_clear = true;
                                 valid = false;
                         } else if (test_bit(AFS_VNODE_ZAP_DATA, &vnode->flags)) {
+                                need_clear = true;
                                 valid = false;
                         } else if (vnode->cb_expires_at - 10 <= now) {
+                                need_clear = true;
                                 valid = false;
                         } else {
                                 valid = true;
@@ -607,6 +610,15 @@ bool afs_check_validity(struct afs_vnode *vnode)
         } while (need_seqretry(&vnode->cb_lock, seq));
 
         done_seqretry(&vnode->cb_lock, seq);
+
+        if (need_clear) {
+                write_seqlock(&vnode->cb_lock);
+                if (cb_break == vnode->cb_break)
+                        __afs_break_callback(vnode);
+                write_sequnlock(&vnode->cb_lock);
+                valid = false;
+        }
+
         return valid;
 }