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LU-122 Revert the patch on bug 21122 and come up with a new fix
[fs/lustre-release.git] / lustre / obdclass / cl_lock.c
index 6535e3a..de487f6 100644 (file)
@@ -26,7 +26,7 @@
  * GPL HEADER END
  */
 /*
- * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
+ * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
  * Use is subject to license terms.
  */
 /*
@@ -77,9 +77,7 @@ static struct lu_kmem_descr cl_lock_caches[] = {
 static int cl_lock_invariant_trusted(const struct lu_env *env,
                                      const struct cl_lock *lock)
 {
-        return
-                cl_is_lock(lock) &&
-                ergo(lock->cll_state == CLS_FREEING, lock->cll_holds == 0) &&
+        return  ergo(lock->cll_state == CLS_FREEING, lock->cll_holds == 0) &&
                 cfs_atomic_read(&lock->cll_ref) >= lock->cll_holds &&
                 lock->cll_holds >= lock->cll_users &&
                 lock->cll_holds >= 0 &&
@@ -132,8 +130,8 @@ static void cl_lock_trace0(int level, const struct lu_env *env,
                            const char *func, const int line)
 {
         struct cl_object_header *h = cl_object_header(lock->cll_descr.cld_obj);
-        CDEBUG(level, "%s: %p@(%i %p %i %d %d %d %d %lx)"
-                      "(%p/%d/%i) at %s():%d\n",
+        CDEBUG(level, "%s: %p@(%d %p %d %d %d %d %d %lx)"
+                      "(%p/%d/%d) at %s():%d\n",
                prefix, lock, cfs_atomic_read(&lock->cll_ref),
                lock->cll_guarder, lock->cll_depth,
                lock->cll_state, lock->cll_error, lock->cll_holds,
@@ -261,7 +259,6 @@ static void cl_lock_free(const struct lu_env *env, struct cl_lock *lock)
 {
         struct cl_object *obj = lock->cll_descr.cld_obj;
 
-        LASSERT(cl_is_lock(lock));
         LINVRNT(!cl_lock_is_mutexed(lock));
 
         ENTRY;
@@ -352,7 +349,6 @@ void cl_lock_get_trust(struct cl_lock *lock)
 {
         struct cl_site *site = cl_object_site(lock->cll_descr.cld_obj);
 
-        LASSERT(cl_is_lock(lock));
         CDEBUG(D_TRACE, "acquiring trusted reference: %d %p %lu\n",
                cfs_atomic_read(&lock->cll_ref), lock, RETIP);
         if (cfs_atomic_inc_return(&lock->cll_ref) == 1)
@@ -513,13 +509,12 @@ static struct cl_lock *cl_lock_lookup(const struct lu_env *env,
         cfs_list_for_each_entry(lock, &head->coh_locks, cll_linkage) {
                 int matched;
 
-                LASSERT(cl_is_lock(lock));
                 matched = cl_lock_ext_match(&lock->cll_descr, need) &&
                           lock->cll_state < CLS_FREEING &&
                           lock->cll_error == 0 &&
                           !(lock->cll_flags & CLF_CANCELLED) &&
                           cl_lock_fits_into(env, lock, need, io);
-                CDEBUG(D_DLMTRACE, "has: "DDESCR"(%i) need: "DDESCR": %d\n",
+                CDEBUG(D_DLMTRACE, "has: "DDESCR"(%d) need: "DDESCR": %d\n",
                        PDESCR(&lock->cll_descr), lock->cll_state, PDESCR(need),
                        matched);
                 if (matched) {
@@ -1225,6 +1220,51 @@ int cl_enqueue_try(const struct lu_env *env, struct cl_lock *lock,
 }
 EXPORT_SYMBOL(cl_enqueue_try);
 
+/**
+ * Cancel the conflicting lock found during previous enqueue.
+ *
+ * \retval 0 conflicting lock has been canceled.
+ * \retval -ve error code.
+ */
+int cl_lock_enqueue_wait(const struct lu_env *env,
+                         struct cl_lock *lock,
+                         int keep_mutex)
+{
+        struct cl_lock  *conflict;
+        int              rc = 0;
+        ENTRY;
+
+        LASSERT(cl_lock_is_mutexed(lock));
+        LASSERT(lock->cll_state == CLS_QUEUING);
+        LASSERT(lock->cll_conflict != NULL);
+
+        conflict = lock->cll_conflict;
+        lock->cll_conflict = NULL;
+
+        cl_lock_mutex_put(env, lock);
+        LASSERT(cl_lock_nr_mutexed(env) == 0);
+
+        cl_lock_mutex_get(env, conflict);
+        cl_lock_cancel(env, conflict);
+        cl_lock_delete(env, conflict);
+
+        while (conflict->cll_state != CLS_FREEING) {
+                rc = cl_lock_state_wait(env, conflict);
+                if (rc != 0)
+                        break;
+        }
+        cl_lock_mutex_put(env, conflict);
+        lu_ref_del(&conflict->cll_reference, "cancel-wait", lock);
+        cl_lock_put(env, conflict);
+
+        if (keep_mutex)
+                cl_lock_mutex_get(env, lock);
+
+        LASSERT(rc <= 0);
+        RETURN(rc);
+}
+EXPORT_SYMBOL(cl_lock_enqueue_wait);
+
 static int cl_enqueue_locked(const struct lu_env *env, struct cl_lock *lock,
                              struct cl_io *io, __u32 enqflags)
 {
@@ -1240,7 +1280,10 @@ static int cl_enqueue_locked(const struct lu_env *env, struct cl_lock *lock,
         do {
                 result = cl_enqueue_try(env, lock, io, enqflags);
                 if (result == CLO_WAIT) {
-                        result = cl_lock_state_wait(env, lock);
+                        if (lock->cll_conflict != NULL)
+                                result = cl_lock_enqueue_wait(env, lock, 1);
+                        else
+                                result = cl_lock_state_wait(env, lock);
                         if (result == 0)
                                 continue;
                 }
@@ -1464,7 +1507,6 @@ int cl_wait(const struct lu_env *env, struct cl_lock *lock)
         LASSERTF(lock->cll_state == CLS_ENQUEUED || lock->cll_state == CLS_HELD,
                  "Wrong state %d \n", lock->cll_state);
         LASSERT(lock->cll_holds > 0);
-        cl_lock_trace(D_DLMTRACE, env, "wait lock", lock);
 
         do {
                 result = cl_wait_try(env, lock);
@@ -1480,6 +1522,7 @@ int cl_wait(const struct lu_env *env, struct cl_lock *lock)
                 cl_lock_error(env, lock, result);
                 cl_lock_lockdep_release(env, lock);
         }
+        cl_lock_trace(D_DLMTRACE, env, "wait lock", lock);
         cl_lock_mutex_put(env, lock);
         LASSERT(ergo(result == 0, lock->cll_state == CLS_HELD));
         RETURN(result);
@@ -1872,7 +1915,7 @@ void cl_lock_page_list_fixup(const struct lu_env *env,
                         page->cp_index < temp->cp_index));
 
                 found = cl_lock_at_page(env, lock->cll_descr.cld_obj,
-                                        page, lock, 0, 0);
+                                        page, lock, 1, 0);
                 if (found == NULL)
                         continue;
 
@@ -2021,20 +2064,6 @@ void cl_locks_prune(const struct lu_env *env, struct cl_object *obj, int cancel)
 }
 EXPORT_SYMBOL(cl_locks_prune);
 
-/**
- * Returns true if \a addr is an address of an allocated cl_lock. Used in
- * assertions. This check is optimistically imprecise, i.e., it occasionally
- * returns true for the incorrect addresses, but if it returns false, then the
- * address is guaranteed to be incorrect. (Should be named cl_lockp().)
- *
- * \see cl_is_page()
- */
-int cl_is_lock(const void *addr)
-{
-        return cfs_mem_is_in_cache(addr, cl_lock_kmem);
-}
-EXPORT_SYMBOL(cl_is_lock);
-
 static struct cl_lock *cl_lock_hold_mutex(const struct lu_env *env,
                                           const struct cl_io *io,
                                           const struct cl_lock_descr *need,
@@ -2093,14 +2122,10 @@ struct cl_lock *cl_lock_request(const struct lu_env *env, struct cl_io *io,
                                 const char *scope, const void *source)
 {
         struct cl_lock       *lock;
-        const struct lu_fid  *fid;
         int                   rc;
-        int                   iter;
         __u32                 enqflags = need->cld_enq_flags;
 
         ENTRY;
-        fid = lu_object_fid(&io->ci_obj->co_lu);
-        iter = 0;
         do {
                 lock = cl_lock_hold_mutex(env, io, need, scope, source);
                 if (!IS_ERR(lock)) {
@@ -2122,7 +2147,6 @@ struct cl_lock *cl_lock_request(const struct lu_env *env, struct cl_io *io,
                         lock = ERR_PTR(rc);
                 } else
                         rc = PTR_ERR(lock);
-                iter++;
         } while (rc == 0);
         RETURN(lock);
 }