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LU-2446 build: Update Whamcloud copyright messages for Intel
[fs/lustre-release.git] / libcfs / libcfs / linux / linux-prim.c
index 9019b3f..d8a9117 100644 (file)
@@ -1,6 +1,4 @@
-/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
- * vim:expandtab:shiftwidth=8:tabstop=8:
- *
+/*
  * GPL HEADER START
  *
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  * 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.
+ *
+ * Copyright (c) 2011, 2012, Intel Corporation.
  */
 /*
  * This file is part of Lustre, http://www.lustre.org/
  */
 
 #define DEBUG_SUBSYSTEM S_LNET
-#ifndef AUTOCONF_INCLUDED
-#include <linux/config.h>
-#endif
 #include <linux/module.h>
 #include <linux/kernel.h>
+#include <linux/fs_struct.h>
 #include <linux/sched.h>
 
 #include <libcfs/libcfs.h>
@@ -72,14 +70,49 @@ cfs_waitq_add(cfs_waitq_t *waitq, cfs_waitlink_t *link)
 }
 EXPORT_SYMBOL(cfs_waitq_add);
 
+#ifndef HAVE___ADD_WAIT_QUEUE_EXCLUSIVE
+
+static inline void __add_wait_queue_exclusive(wait_queue_head_t *q,
+                                              wait_queue_t *wait)
+{
+        wait->flags |= WQ_FLAG_EXCLUSIVE;
+        __add_wait_queue(q, wait);
+}
+
+#endif /* HAVE___ADD_WAIT_QUEUE_EXCLUSIVE */
+
 void
 cfs_waitq_add_exclusive(cfs_waitq_t *waitq,
-                             cfs_waitlink_t *link)
+                        cfs_waitlink_t *link)
 {
         add_wait_queue_exclusive(LINUX_WAITQ_HEAD(waitq), LINUX_WAITQ(link));
 }
 EXPORT_SYMBOL(cfs_waitq_add_exclusive);
 
+/**
+ * wait_queue_t of Linux (version < 2.6.34) is a FIFO list for exclusively
+ * waiting threads, which is not always desirable because all threads will
+ * be waken up again and again, even user only needs a few of them to be
+ * active most time. This is not good for performance because cache can
+ * be polluted by different threads.
+ *
+ * LIFO list can resolve this problem because we always wakeup the most
+ * recent active thread by default.
+ *
+ * NB: please don't call non-exclusive & exclusive wait on the same
+ * waitq if cfs_waitq_add_exclusive_head is used.
+ */
+void
+cfs_waitq_add_exclusive_head(cfs_waitq_t *waitq, cfs_waitlink_t *link)
+{
+       unsigned long flags;
+
+       spin_lock_irqsave(&LINUX_WAITQ_HEAD(waitq)->lock, flags);
+       __add_wait_queue_exclusive(LINUX_WAITQ_HEAD(waitq), LINUX_WAITQ(link));
+       spin_unlock_irqrestore(&LINUX_WAITQ_HEAD(waitq)->lock, flags);
+}
+EXPORT_SYMBOL(cfs_waitq_add_exclusive_head);
+
 void
 cfs_waitq_del(cfs_waitq_t *waitq, cfs_waitlink_t *link)
 {
@@ -123,18 +156,26 @@ cfs_waitq_wait(cfs_waitlink_t *link, cfs_task_state_t state)
 EXPORT_SYMBOL(cfs_waitq_wait);
 
 int64_t
-cfs_waitq_timedwait(cfs_waitlink_t *link, cfs_task_state_t state, int64_t timeout)
+cfs_waitq_timedwait(cfs_waitlink_t *link, cfs_task_state_t state,
+                    int64_t timeout)
 {
         return schedule_timeout(timeout);
 }
 EXPORT_SYMBOL(cfs_waitq_timedwait);
 
 void
-cfs_schedule_timeout(cfs_task_state_t state, int64_t timeout)
+cfs_schedule_timeout_and_set_state(cfs_task_state_t state, int64_t timeout)
 {
         set_current_state(state);
         schedule_timeout(timeout);
 }
+EXPORT_SYMBOL(cfs_schedule_timeout_and_set_state);
+
+void
+cfs_schedule_timeout(int64_t timeout)
+{
+        schedule_timeout(timeout);
+}
 EXPORT_SYMBOL(cfs_schedule_timeout);
 
 void
@@ -212,7 +253,7 @@ EXPORT_SYMBOL(cfs_timer_deadline);
 void cfs_enter_debugger(void)
 {
 #if defined(CONFIG_KGDB)
-        BREAKPOINT();
+//        BREAKPOINT();
 #elif defined(__arch_um__)
         asm("int $3");
 #else
@@ -223,48 +264,32 @@ void cfs_enter_debugger(void)
 void cfs_daemonize(char *str) {
         unsigned long flags;
 
-        lock_kernel();
-#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,5,63))
         daemonize(str);
-#else
-        daemonize();
-        exit_files(current);
-        reparent_to_init();
-        snprintf (current->comm, sizeof (current->comm), "%s", str);
-#endif
         SIGNAL_MASK_LOCK(current, flags);
         sigfillset(&current->blocked);
         RECALC_SIGPENDING;
         SIGNAL_MASK_UNLOCK(current, flags);
-        unlock_kernel();
 }
 
 int cfs_daemonize_ctxt(char *str) {
-        struct task_struct *tsk = current;
-        struct fs_struct *fs = NULL;
 
         cfs_daemonize(str);
+#ifndef HAVE_UNSHARE_FS_STRUCT
+        {
+        struct task_struct *tsk = current;
+        struct fs_struct *fs = NULL;
         fs = copy_fs_struct(tsk->fs);
         if (fs == NULL)
                 return -ENOMEM;
         exit_fs(tsk);
         tsk->fs = fs;
+        }
+#else
+        unshare_fs_struct();
+#endif
         return 0;
 }
 
-
-sigset_t
-cfs_get_blockedsigs(void)
-{
-        unsigned long          flags;
-        sigset_t        old;
-
-        SIGNAL_MASK_LOCK(current, flags);
-        old = current->blocked;
-        SIGNAL_MASK_UNLOCK(current, flags);
-        return old;
-}
-
 sigset_t
 cfs_block_allsigs(void)
 {
@@ -280,18 +305,32 @@ cfs_block_allsigs(void)
         return old;
 }
 
-sigset_t
-cfs_block_sigs(sigset_t bits)
+sigset_t cfs_block_sigs(unsigned long sigs)
 {
-        unsigned long  flags;
-        sigset_t        old;
+       unsigned long  flags;
+       sigset_t        old;
 
-        SIGNAL_MASK_LOCK(current, flags);
-        old = current->blocked;
-        current->blocked = bits;
-        RECALC_SIGPENDING;
-        SIGNAL_MASK_UNLOCK(current, flags);
-        return old;
+       SIGNAL_MASK_LOCK(current, flags);
+       old = current->blocked;
+       sigaddsetmask(&current->blocked, sigs);
+       RECALC_SIGPENDING;
+       SIGNAL_MASK_UNLOCK(current, flags);
+       return old;
+}
+
+/* Block all signals except for the @sigs */
+sigset_t cfs_block_sigsinv(unsigned long sigs)
+{
+       unsigned long flags;
+       sigset_t old;
+
+       SIGNAL_MASK_LOCK(current, flags);
+       old = current->blocked;
+       sigaddsetmask(&current->blocked, ~sigs);
+       RECALC_SIGPENDING;
+       SIGNAL_MASK_UNLOCK(current, flags);
+
+       return old;
 }
 
 void
@@ -335,11 +374,12 @@ libcfs_arch_cleanup(void)
 
 EXPORT_SYMBOL(libcfs_arch_init);
 EXPORT_SYMBOL(libcfs_arch_cleanup);
+EXPORT_SYMBOL(cfs_enter_debugger);
 EXPORT_SYMBOL(cfs_daemonize);
 EXPORT_SYMBOL(cfs_daemonize_ctxt);
 EXPORT_SYMBOL(cfs_block_allsigs);
 EXPORT_SYMBOL(cfs_block_sigs);
-EXPORT_SYMBOL(cfs_get_blockedsigs);
+EXPORT_SYMBOL(cfs_block_sigsinv);
 EXPORT_SYMBOL(cfs_restore_sigs);
 EXPORT_SYMBOL(cfs_signal_pending);
 EXPORT_SYMBOL(cfs_clear_sigpending);