LU-2101 clio: cl_sync_io_wait() need a barrier

[fs/lustre-release.git] / lustre / obdclass / cl_io.c

diff --git a/lustre/obdclass/cl_io.c b/lustre/obdclass/cl_io.c
index 5bae736..ecfe76e 100644 (file)
--- a/lustre/obdclass/cl_io.c
+++ b/lustre/obdclass/cl_io.c
@@ -27,7 +27,7 @@
  * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
  * Use is subject to license terms.
  *
- * Copyright (c) 2011, 2012, Whamcloud, Inc.
+ * Copyright (c) 2011, 2012, Intel Corporation.
  */
 /*
  * This file is part of Lustre, http://www.lustre.org/
@@ -44,9 +44,6 @@
 #include <obd_support.h>
 #include <lustre_fid.h>
 #include <libcfs/list.h>
-/* lu_time_global_{init,fini}() */
-#include <lu_time.h>
-
 #include <cl_object.h>
 #include "cl_internal.h"
 
@@ -1106,9 +1103,9 @@ void cl_page_list_add(struct cl_page_list *plist, struct cl_page *page)
         LASSERT(page->cp_owner != NULL);
         LINVRNT(plist->pl_owner == cfs_current());
 
-        cfs_lockdep_off();
-        cfs_mutex_lock(&page->cp_mutex);
-        cfs_lockdep_on();
+       lockdep_off();
+       mutex_lock(&page->cp_mutex);
+       lockdep_on();
         LASSERT(cfs_list_empty(&page->cp_batch));
         cfs_list_add_tail(&page->cp_batch, &plist->pl_pages);
         ++plist->pl_nr;
@@ -1129,9 +1126,9 @@ void cl_page_list_del(const struct lu_env *env,
 
         ENTRY;
         cfs_list_del_init(&page->cp_batch);
-        cfs_lockdep_off();
-        cfs_mutex_unlock(&page->cp_mutex);
-        cfs_lockdep_on();
+       lockdep_off();
+       mutex_unlock(&page->cp_mutex);
+       lockdep_on();
         --plist->pl_nr;
         lu_ref_del_at(&page->cp_reference, page->cp_queue_ref, "queue", plist);
         cl_page_put(env, page);
@@ -1196,9 +1193,9 @@ void cl_page_list_disown(const struct lu_env *env,
                 LASSERT(plist->pl_nr > 0);
 
                 cfs_list_del_init(&page->cp_batch);
-                cfs_lockdep_off();
-                cfs_mutex_unlock(&page->cp_mutex);
-                cfs_lockdep_on();
+               lockdep_off();
+               mutex_unlock(&page->cp_mutex);
+               lockdep_on();
                 --plist->pl_nr;
                 /*
                  * cl_page_disown0 rather than usual cl_page_disown() is used,
@@ -1686,11 +1683,12 @@ EXPORT_SYMBOL(cl_req_attr_set);
  */
 void cl_sync_io_init(struct cl_sync_io *anchor, int nrpages)
 {
-        ENTRY;
-        cfs_waitq_init(&anchor->csi_waitq);
-        cfs_atomic_set(&anchor->csi_sync_nr, nrpages);
-        anchor->csi_sync_rc  = 0;
-        EXIT;
+       ENTRY;
+       cfs_waitq_init(&anchor->csi_waitq);
+       cfs_atomic_set(&anchor->csi_sync_nr, nrpages);
+       cfs_atomic_set(&anchor->csi_barrier, nrpages > 0);
+       anchor->csi_sync_rc = 0;
+       EXIT;
 }
 EXPORT_SYMBOL(cl_sync_io_init);
 
@@ -1728,8 +1726,16 @@ int cl_sync_io_wait(const struct lu_env *env, struct cl_io *io,
         }
         LASSERT(cfs_atomic_read(&anchor->csi_sync_nr) == 0);
         cl_page_list_assume(env, io, queue);
-        POISON(anchor, 0x5a, sizeof *anchor);
-        RETURN(rc);
+
+       /* wait until cl_sync_io_note() has done wakeup */
+       while (unlikely(cfs_atomic_read(&anchor->csi_barrier) != 0)) {
+#ifdef __KERNEL__
+               cpu_relax();
+#endif
+       }
+
+       POISON(anchor, 0x5a, sizeof *anchor);
+       RETURN(rc);
 }
 EXPORT_SYMBOL(cl_sync_io_wait);
 
@@ -1747,8 +1753,11 @@ void cl_sync_io_note(struct cl_sync_io *anchor, int ioret)
          * IO.
          */
         LASSERT(cfs_atomic_read(&anchor->csi_sync_nr) > 0);
-        if (cfs_atomic_dec_and_test(&anchor->csi_sync_nr))
-                cfs_waitq_broadcast(&anchor->csi_waitq);
-        EXIT;
+       if (cfs_atomic_dec_and_test(&anchor->csi_sync_nr)) {
+               cfs_waitq_broadcast(&anchor->csi_waitq);
+               /* it's safe to nuke or reuse anchor now */
+               cfs_atomic_set(&anchor->csi_barrier, 0);
+       }
+       EXIT;
 }
 EXPORT_SYMBOL(cl_sync_io_note);