Linux: Tidy up freezer code

Linux now provides try_to_freeze(), which can be used to replace
all of our refrigerator code. This has been in the tree for a long
time, and actually predates many of the changes we've been modifying
our code to work with. So, use try_to_freeze wherever we can, and keep
a simpler compatibility function for kernels which are too old to have
it.

Change-Id: Iec50f83382f46d2b17b43da815a75755ea916bc6
Reviewed-on: http://gerrit.openafs.org/1845
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: Derrick Brashear <shadow@dementia.org>

diff --git a/acinclude.m4 b/acinclude.m4
index 59aa9ab..6535a91 100644 (file)
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -868,7 +868,6 @@ case $AFS_SYSNAME in *_linux* | *_umlinux*)
                 LINUX_SCHED_STRUCT_TASK_STRUCT_HAS_SIGNAL_RLIM
                 LINUX_SCHED_STRUCT_TASK_STRUCT_HAS_EXIT_STATE
                 LINUX_SCHED_STRUCT_TASK_STRUCT_HAS_TGID
-                LINUX_SCHED_STRUCT_TASK_STRUCT_HAS_TODO
                 LINUX_SCHED_STRUCT_TASK_STRUCT_HAS_THREAD_INFO
                 LINUX_EXPORTS_TASKLIST_LOCK
                 LINUX_GET_SB_HAS_STRUCT_VFSMOUNT
@@ -876,6 +875,7 @@ case $AFS_SYSNAME in *_linux* | *_umlinux*)
                 AC_CHECK_LINUX_HEADER([freezer.h])
                 LINUX_HAVE_SVC_ADDR_IN
                 LINUX_REFRIGERATOR
+                LINUX_HAVE_TRY_TO_FREEZE
                 LINUX_LINUX_KEYRING_SUPPORT
                 LINUX_KEY_ALLOC_NEEDS_STRUCT_TASK
                 LINUX_KEY_ALLOC_NEEDS_CRED

diff --git a/src/afs/LINUX/osi_compat.h b/src/afs/LINUX/osi_compat.h
index efdd13b..53d486f 100644 (file)
--- a/src/afs/LINUX/osi_compat.h
+++ b/src/afs/LINUX/osi_compat.h
@@ -9,6 +9,10 @@
 #ifndef AFS_LINUX_OSI_COMPAT_H
 #define AFS_LINUX_OSI_COMPAT_H
 
+#if defined(HAVE_LINUX_FREEZER_H)
+# include <linux/freezer.h>
+#endif
+
 #ifndef DO_SYNC_READ
 static inline int
 do_sync_read(struct file *fp, char *buf, size_t count, loff_t *offp) {
@@ -267,6 +271,24 @@ kernel_getsockopt(struct socket *sockp, int level, int name, char *val,
 
     return ret;
 }
+#endif
 
+#ifdef HAVE_TRY_TO_FREEZE
+static inline void
+afs_try_to_freeze() {
+# ifdef LINUX_REFRIGERATOR_TAKES_PF_FREEZE
+    try_to_freeze(PF_FREEZE);
+# else
+    try_to_freeze();
+# endif
+}
+#else
+static inline void
+afs_try_to_freeze() {
+# ifdef CONFIG_PM
+    if (current->flags & PF_FREEZE) {
+       refrigerator(PF_FREEZE);
+# endif
+}
 #endif
 

diff --git a/src/afs/LINUX/osi_sleep.c b/src/afs/LINUX/osi_sleep.c
index 45464d7..992f47a 100644 (file)
--- a/src/afs/LINUX/osi_sleep.c
+++ b/src/afs/LINUX/osi_sleep.c
@@ -14,9 +14,7 @@
 #include "afs/sysincludes.h"   /* Standard vendor system headers */
 #include "afsincludes.h"       /* Afs-based standard headers */
 #include "afs/afs_stats.h"     /* afs statistics */
-#if defined(HAVE_LINUX_FREEZER_H)
-#include <linux/freezer.h>
-#endif
+#include "osi_compat.h"
 
 static char waitV, dummyV;
 
@@ -183,28 +181,8 @@ afs_osi_SleepSig(void *event)
        AFS_ASSERT_GLOCK();
        AFS_GUNLOCK();
        schedule();
-#ifdef CONFIG_PM
-       if (
-#ifdef PF_FREEZE
-           current->flags & PF_FREEZE
-#else
-#if defined(STRUCT_TASK_STRUCT_HAS_TODO)
-           !current->todo
-#else
-#if defined(STRUCT_TASK_STRUCT_HAS_THREAD_INFO)
-            test_ti_thread_flag(current->thread_info, TIF_FREEZE)
-#else
-            test_ti_thread_flag(task_thread_info(current), TIF_FREEZE)
-#endif
-#endif
-#endif
-           )
-#ifdef LINUX_REFRIGERATOR_TAKES_PF_FREEZE
-           refrigerator(PF_FREEZE);
-#else
-           refrigerator();
-#endif
-#endif
+       try_to_freeze();
+
        AFS_GLOCK();
        if (signal_pending(current)) {
            retval = EINTR;
@@ -278,33 +256,12 @@ afs_osi_TimedSleep(void *event, afs_int32 ams, int aintok)
      * from artifically increasing. */
     AFS_GUNLOCK();
 
-    if (aintok) {
-       if (schedule_timeout(ticks))
+    if (schedule_timeout(ticks)) {
+       if (aintok)
            code = EINTR;
-    } else
-       schedule_timeout(ticks);
-#ifdef CONFIG_PM
-    if (
-#ifdef PF_FREEZE
-           current->flags & PF_FREEZE
-#else
-#if defined(STRUCT_TASK_STRUCT_HAS_TODO)
-           !current->todo
-#else
-#if defined(STRUCT_TASK_STRUCT_HAS_THREAD_INFO)
-            test_ti_thread_flag(current->thread_info, TIF_FREEZE)
-#else
-            test_ti_thread_flag(task_thread_info(current), TIF_FREEZE)
-#endif
-#endif
-#endif
-           )
-#ifdef LINUX_REFRIGERATOR_TAKES_PF_FREEZE
-       refrigerator(PF_FREEZE);
-#else
-       refrigerator();
-#endif
-#endif
+    }
+
+    try_to_freeze();
 
     AFS_GLOCK();
     remove_wait_queue(&evp->cond, &wait);

diff --git a/src/cf/linux-test4.m4 b/src/cf/linux-test4.m4
index cd1d643..a4d5b71 100644 (file)
--- a/src/cf/linux-test4.m4
+++ b/src/cf/linux-test4.m4
@@ -483,8 +483,10 @@ AC_DEFUN([LINUX_REFRIGERATOR], [
 [refrigerator(PF_FREEZE);],
       ac_cv_linux_func_refrigerator_takes_pf_freeze=yes,
       ac_cv_linux_func_refrigerator_takes_pf_freeze=no)])
-  AC_MSG_RESULT($ac_cv_linux_func_refrigerator_takes_pf_freeze)])
-
+  AC_MSG_RESULT($ac_cv_linux_func_refrigerator_takes_pf_freeze)
+  if test "x$ac_cv_linux_func_refrigerator_takes_pf_freeze" = "xyes"; then
+    AC_DEFINE([LINUX_REFRIGERATOR_TAKES_PF_FREEZE], 1, [define if your refrigerator takes PF_FREEZE])
+  fi])
 
 AC_DEFUN([LINUX_IOP_I_CREATE_TAKES_NAMEIDATA], [
   AC_MSG_CHECKING([whether inode_operations.create takes a nameidata])
@@ -711,17 +713,6 @@ AC_DEFUN([LINUX_HAVE_D_ALLOC_ANON], [
     AC_DEFINE([HAVE_LINUX_D_ALLOC_ANON], 1, [define if your kernel has d_alloc_anon()])
   fi])
 
-AC_DEFUN([LINUX_SCHED_STRUCT_TASK_STRUCT_HAS_TODO], [
-  AC_MSG_CHECKING([for todo in struct task_struct])
-  AC_CACHE_VAL([ac_cv_linux_sched_struct_task_struct_has_todo], [
-    AC_TRY_KBUILD(
-[#include <linux/sched.h>],
-[struct task_struct _tsk;
-printk("%d\n", _tsk.todo);],
-      ac_cv_linux_sched_struct_task_struct_has_todo=yes,
-      ac_cv_linux_sched_struct_task_struct_has_todo=no)])
-  AC_MSG_RESULT($ac_cv_linux_sched_struct_task_struct_has_todo)])
-
 AC_DEFUN([LINUX_INIT_WORK_HAS_DATA], [
   AC_MSG_CHECKING([whether INIT_WORK has a _data argument])
   AC_CACHE_VAL([ac_cv_linux_init_work_has_data], [
@@ -1220,5 +1211,25 @@ AC_DEFUN([LINUX_HAVE_KERNEL_SETSOCKOPT], [
   AC_MSG_RESULT($ac_cv_linux_have_kernel_setsockopt)
   if test "x$ac_cv_linux_have_kernel_setsockopt" = "xyes"; then
     AC_DEFINE([HAVE_KERNEL_SETSOCKOPT], 1, [define if your kernel has the kernel_setsockopt function])
+
+AC_DEFUN([LINUX_HAVE_TRY_TO_FREEZE], [
+  AC_MSG_CHECKING([for try_to_freeze])
+  AC_CACHE_VAL([ac_cv_linux_have_try_to_freeze], [
+    AC_TRY_KBUILD(
+[#include <linux/sched.h>
+#ifdef FREEZER_H_EXISTS
+#include <linux/freezer.h>
+#endif],
+[#ifdef LINUX_REFRIGERATOR_TAKES_PF_FREEZE
+   try_to_freeze(PF_FREEZE);
+#else
+   try_to_freeze();
+#endif
+],
+      ac_cv_linux_have_try_to_freeze=yes,
+      ac_cv_linux_have_try_to_freeze=no)])
+  AC_MSG_RESULT($ac_cv_linux_have_try_to_freeze)
+  if test "x$ac_cv_linux_have_try_to_freeze" = "xyes"; then
+    AC_DEFINE([HAVE_TRY_TO_FREEZE], 1, [define if your kernel has the try_to_freeze function])
   fi])