locks: prevent deletion of locked entries

To keep consistency inside transactions started by locking an entry or
an inode, this change delays the removal of entries that are currently
locked by one or more clients. Once all locks are released, the removal
is processed.

It has also been improved the detection of stale inodes in the locking
code of EC.

Fixes: #990
Change-Id: Ic8ba23d9480f80c7f74e7a310bf8a15922320fd5
Signed-off-by: Xavi Hernandez <xhernandez@redhat.com>

1 files changed, 8 insertions, 11 deletions

diff --git a/xlators/features/locks/src/entrylk.c b/xlators/features/locks/src/entrylk.c
index 0911659b43..d5babcc325 100644
--- a/xlators/features/locks/src/entrylk.c
+++ b/xlators/features/locks/src/entrylk.c
@@ -204,9 +204,9 @@ out:
     return revoke_lock;
 }
 
-static gf_boolean_t
-__entrylk_needs_contention_notify(xlator_t *this, pl_entry_lock_t *lock,
-                                  struct timespec *now)
+void
+entrylk_contention_notify_check(xlator_t *this, pl_entry_lock_t *lock,
+                                struct timespec *now, struct list_head *contend)
 {
     posix_locks_private_t *priv;
     int64_t elapsed;
@@ -216,7 +216,7 @@ __entrylk_needs_contention_notify(xlator_t *this, pl_entry_lock_t *lock,
     /* If this lock is in a list, it means that we are about to send a
      * notification for it, so no need to do anything else. */
     if (!list_empty(&lock->contend)) {
-        return _gf_false;
+        return;
     }
 
     elapsed = now->tv_sec;
@@ -225,7 +225,7 @@ __entrylk_needs_contention_notify(xlator_t *this, pl_entry_lock_t *lock,
         elapsed--;
     }
     if (elapsed < priv->notify_contention_delay) {
-        return _gf_false;
+        return;
     }
 
     /* All contention notifications will be sent outside of the locked
@@ -238,7 +238,7 @@ __entrylk_needs_contention_notify(xlator_t *this, pl_entry_lock_t *lock,
 
     lock->contention_time = *now;
 
-    return _gf_true;
+    list_add_tail(&lock->contend, contend);
 }
 
 void
@@ -332,9 +332,7 @@ __entrylk_grantable(xlator_t *this, pl_dom_list_t *dom, pl_entry_lock_t *lock,
                     break;
                 }
             }
-            if (__entrylk_needs_contention_notify(this, tmp, now)) {
-                list_add_tail(&tmp->contend, contend);
-            }
+            entrylk_contention_notify_check(this, tmp, now, contend);
         }
     }
 
@@ -697,10 +695,9 @@ __grant_blocked_entry_locks(xlator_t *this, pl_inode_t *pl_inode,
         bl_ret = __lock_entrylk(bl->this, pl_inode, bl, 0, dom, now, contend);
 
         if (bl_ret == 0) {
-            list_add(&bl->blocked_locks, granted);
+            list_add_tail(&bl->blocked_locks, granted);
         }
     }
-    return;
 }
 
 /* Grants locks if possible which are blocked on a lock */