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LU-10841 ldlm: ASSERTION(lock->l_granted_mode!=lock->l_req_mode)
[fs/lustre-release.git] / lustre / ldlm / ldlm_plain.c
index 14a76b6..aa074f5 100644 (file)
  *
  * You should have received a copy of the GNU General Public License
  * version 2 along with this program; If not, see
- * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
- *
- * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
- * CA 95054 USA or visit www.sun.com if you need additional information or
- * have any questions.
+ * http://www.gnu.org/licenses/gpl-2.0.html
  *
  * GPL HEADER END
  */
@@ -27,7 +23,7 @@
  * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
  * Use is subject to license terms.
  *
- * Copyright (c) 2011, Intel Corporation.
+ * Copyright (c) 2011, 2017, Intel Corporation.
  */
 /*
  * This file is part of Lustre, http://www.lustre.org/
 
 #define DEBUG_SUBSYSTEM S_LDLM
 
-#ifdef __KERNEL__
 #include <lustre_dlm.h>
 #include <obd_support.h>
 #include <lustre_lib.h>
-#else
-#include <liblustre.h>
-#endif
 
 #include "ldlm_internal.h"
 
@@ -76,15 +68,15 @@ static inline int
 ldlm_plain_compat_queue(struct list_head *queue, struct ldlm_lock *req,
                        struct list_head *work_list)
 {
-       ldlm_mode_t req_mode = req->l_req_mode;
-       struct ldlm_lock *lock;
-       struct list_head *tmp;
+       enum ldlm_mode req_mode = req->l_req_mode;
+       struct ldlm_lock *lock, *next_lock;
        int compat = 1;
        ENTRY;
 
        lockmode_verify(req_mode);
 
-       list_for_each_entry(lock, queue, l_res_link) {
+       list_for_each_entry_safe(lock, next_lock, queue, l_res_link) {
+
                /* We stop walking the queue if we hit ourselves so we don't
                 * take conflicting locks enqueued after us into account,
                 * or we'd wait forever. */
@@ -92,8 +84,10 @@ ldlm_plain_compat_queue(struct list_head *queue, struct ldlm_lock *req,
                        RETURN(compat);
 
                /* Advance loop cursor to last lock of mode group. */
-               tmp = &list_entry(lock->l_sl_mode.prev, struct ldlm_lock,
-                                 l_sl_mode)->l_res_link;
+               next_lock = list_entry(list_entry(lock->l_sl_mode.prev,
+                                                 struct ldlm_lock,
+                                                 l_sl_mode)->l_res_link.next,
+                                      struct ldlm_lock, l_res_link);
 
                if (lockmode_compat(lock->l_req_mode, req_mode))
                         continue;
@@ -129,29 +123,22 @@ ldlm_plain_compat_queue(struct list_head *queue, struct ldlm_lock *req,
  * This function looks for any conflicts for \a lock in the granted or
  * waiting queues. The lock is granted if no conflicts are found in
  * either queue.
- *
- * If \a first_enq is 0 (ie, called from ldlm_reprocess_queue):
- *   - blocking ASTs have already been sent
- *
- * If \a first_enq is 1 (ie, called from ldlm_lock_enqueue):
- *   - blocking ASTs have not been sent yet, so list of conflicting locks
- *     would be collected and ASTs sent.
  */
 int ldlm_process_plain_lock(struct ldlm_lock *lock, __u64 *flags,
-                           int first_enq, ldlm_error_t *err,
-                           struct list_head *work_list)
+                           enum ldlm_process_intention intention,
+                           enum ldlm_error *err, struct list_head *work_list)
 {
        struct ldlm_resource *res = lock->l_resource;
-       struct list_head rpc_list;
+       struct list_head *grant_work = intention == LDLM_PROCESS_ENQUEUE ?
+                                                       NULL : work_list;
        int rc;
        ENTRY;
 
        LASSERT(lock->l_granted_mode != lock->l_req_mode);
        check_res_locked(res);
-       LASSERT(list_empty(&res->lr_converting));
-       INIT_LIST_HEAD(&rpc_list);
+       *err = ELDLM_OK;
 
-        if (!first_enq) {
+       if (intention == LDLM_PROCESS_RESCAN) {
                 LASSERT(work_list != NULL);
                 rc = ldlm_plain_compat_queue(&res->lr_granted, lock, NULL);
                 if (!rc)
@@ -161,46 +148,30 @@ int ldlm_process_plain_lock(struct ldlm_lock *lock, __u64 *flags,
                         RETURN(LDLM_ITER_STOP);
 
                 ldlm_resource_unlink_lock(lock);
-                ldlm_grant_lock(lock, work_list);
+               ldlm_grant_lock(lock, grant_work);
                 RETURN(LDLM_ITER_CONTINUE);
         }
 
- restart:
-        rc = ldlm_plain_compat_queue(&res->lr_granted, lock, &rpc_list);
-        rc += ldlm_plain_compat_queue(&res->lr_waiting, lock, &rpc_list);
-
-        if (rc != 2) {
-                /* If either of the compat_queue()s returned 0, then we
-                 * have ASTs to send and must go onto the waiting list.
-                 *
-                 * bug 2322: we used to unlink and re-add here, which was a
-                 * terrible folly -- if we goto restart, we could get
-                 * re-ordered!  Causes deadlock, because ASTs aren't sent! */
-               if (list_empty(&lock->l_res_link))
-                        ldlm_resource_add_lock(res, &res->lr_waiting, lock);
-                unlock_res(res);
-                rc = ldlm_run_ast_work(ldlm_res_to_ns(res), &rpc_list,
-                                       LDLM_WORK_BL_AST);
-                lock_res(res);
-               if (rc == -ERESTART)
-                       GOTO(restart, rc);
-                *flags |= LDLM_FL_BLOCK_GRANTED;
-        } else {
-                ldlm_resource_unlink_lock(lock);
-                ldlm_grant_lock(lock, NULL);
-        }
-        RETURN(0);
+       rc = ldlm_plain_compat_queue(&res->lr_granted, lock, work_list);
+       rc += ldlm_plain_compat_queue(&res->lr_waiting, lock, work_list);
+
+       if (rc == 2) {
+               ldlm_resource_unlink_lock(lock);
+               ldlm_grant_lock(lock, grant_work);
+       }
+
+       RETURN(LDLM_ITER_CONTINUE);
 }
 #endif /* HAVE_SERVER_SUPPORT */
 
-void ldlm_plain_policy_wire_to_local(const ldlm_wire_policy_data_t *wpolicy,
-                                     ldlm_policy_data_t *lpolicy)
+void ldlm_plain_policy_wire_to_local(const union ldlm_wire_policy_data *wpolicy,
+                                    union ldlm_policy_data *lpolicy)
 {
-        /* No policy for plain locks */
+       /* No policy for plain locks */
 }
 
-void ldlm_plain_policy_local_to_wire(const ldlm_policy_data_t *lpolicy,
-                                     ldlm_wire_policy_data_t *wpolicy)
+void ldlm_plain_policy_local_to_wire(const union ldlm_policy_data *lpolicy,
+                                    union ldlm_wire_policy_data *wpolicy)
 {
-        /* No policy for plain locks */
+       /* No policy for plain locks */
 }