Reviewed and applied spl-00-rm-gpl-symbol-notifier_chain.patch

from Ricardo which removes a dependency on the GPL-only symbol
needed for a panic time notifier.  This funcationality was never
used and this improves our portability.



git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@159 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c

3 files changed, 35 insertions, 103 deletions

diff --git a/autoconf/spl-build.m4 b/autoconf/spl-build.m4
index e13c5b875..61d11e8ff 100644
--- a/autoconf/spl-build.m4
+++ b/autoconf/spl-build.m4
@@ -230,10 +230,10 @@ dnl # SPL_LINUX_TRY_COMPILE like AC_TRY_COMPILE
 dnl #
 AC_DEFUN([SPL_LINUX_TRY_COMPILE],
 	[SPL_LINUX_COMPILE_IFELSE(
-        [AC_LANG_SOURCE([SPL_LANG_PROGRAM([[$1]], [[$2]])])],
-        [modules],
-        [test -s build/conftest.o],
-        [$3], [$4])
+	[AC_LANG_SOURCE([SPL_LANG_PROGRAM([[$1]], [[$2]])])],
+	[modules],
+	[test -s build/conftest.o],
+	[$3], [$4])
 ])
 
 dnl #
@@ -296,7 +296,7 @@ dnl #
 AC_DEFUN([SPL_CHECK_HEADER],
 	[AC_MSG_CHECKING([whether header $1 exists])
 	SPL_LINUX_TRY_COMPILE([
-        	#include <$1>
+		#include <$1>
 	],[
 		return 0;
 	],[
@@ -316,36 +316,15 @@ dnl #
 AC_DEFUN([SPL_AC_TYPE_UINTPTR_T],
 	[AC_MSG_CHECKING([whether kernel defines uintptr_t])
 	SPL_LINUX_TRY_COMPILE([
-	        #include <linux/types.h>
+		#include <linux/types.h>
 	],[
-	        uintptr_t *ptr;
+		uintptr_t *ptr;
 	],[
-	        AC_MSG_RESULT([yes])
-	        AC_DEFINE(HAVE_UINTPTR_T, 1,
+		AC_MSG_RESULT([yes])
+		AC_DEFINE(HAVE_UINTPTR_T, 1,
 		          [kernel defines uintptr_t])
 	],[
-	        AC_MSG_RESULT([no])
-	])
-])
-
-dnl #
-dnl # 2.6.19 API change,
-dnl # panic_notifier_list use atomic_notifier operations
-dnl #
-
-AC_DEFUN([SPL_AC_ATOMIC_PANIC_NOTIFIER],
-	[AC_MSG_CHECKING([whether panic_notifier_list is atomic])
-	SPL_LINUX_TRY_COMPILE([
-	        #include <linux/notifier.h>
-	        #include <linux/kernel.h>
-	],[
-	        struct atomic_notifier_head panic_notifier_list;
-	],[
-	        AC_MSG_RESULT(yes)
-	        AC_DEFINE(HAVE_ATOMIC_PANIC_NOTIFIER, 1,
-	                [panic_notifier_list is atomic])
-	],[
-	        AC_MSG_RESULT(no)
+		AC_MSG_RESULT([no])
 	])
 ])
 
@@ -356,17 +335,16 @@ dnl #
 AC_DEFUN([SPL_AC_3ARGS_INIT_WORK],
 	[AC_MSG_CHECKING([whether INIT_WORK wants 3 args])
 	SPL_LINUX_TRY_COMPILE([
-	        #include <linux/workqueue.h>
+		#include <linux/workqueue.h>
 	],[
-	        struct work_struct work;
-
-	        INIT_WORK(&work, NULL, NULL);
+		struct work_struct work;
+		INIT_WORK(&work, NULL, NULL);
 	],[
-	        AC_MSG_RESULT(yes)
-	        AC_DEFINE(HAVE_3ARGS_INIT_WORK, 1,
-	                  [INIT_WORK wants 3 args])
+		AC_MSG_RESULT(yes)
+		AC_DEFINE(HAVE_3ARGS_INIT_WORK, 1,
+		          [INIT_WORK wants 3 args])
 	],[
-	        AC_MSG_RESULT(no)
+		AC_MSG_RESULT(no)
 	])
 ])
 
@@ -377,15 +355,15 @@ dnl #
 AC_DEFUN([SPL_AC_2ARGS_REGISTER_SYSCTL],
 	[AC_MSG_CHECKING([whether register_sysctl_table() wants 2 args])
 	SPL_LINUX_TRY_COMPILE([
-	        #include <linux/sysctl.h>
+		#include <linux/sysctl.h>
 	],[
-	        return register_sysctl_table(NULL,0);
+		return register_sysctl_table(NULL,0);
 	],[
-        AC_MSG_RESULT(yes)
-	        AC_DEFINE(HAVE_2ARGS_REGISTER_SYSCTL, 1,
-        	          [register_sysctl_table() wants 2 args])
+		AC_MSG_RESULT(yes)
+		AC_DEFINE(HAVE_2ARGS_REGISTER_SYSCTL, 1,
+		          [register_sysctl_table() wants 2 args])
 	],[
-	        AC_MSG_RESULT(no)
+		AC_MSG_RESULT(no)
 	])
 ])
 
@@ -415,18 +393,18 @@ dnl #
 AC_DEFUN([SPL_AC_PATH_IN_NAMEIDATA],
 	[AC_MSG_CHECKING([whether struct path used in struct nameidata])
 	SPL_LINUX_TRY_COMPILE([
-	        #include <linux/namei.h>
+		#include <linux/namei.h>
 	],[
-	        struct nameidata nd;
+		struct nameidata nd;
 
 		nd.path.mnt = NULL;
 		nd.path.dentry = NULL;
 	],[
-	        AC_MSG_RESULT(yes)
-	        AC_DEFINE(HAVE_PATH_IN_NAMEIDATA, 1,
-	                  [struct path used in struct nameidata])
+		AC_MSG_RESULT(yes)
+		AC_DEFINE(HAVE_PATH_IN_NAMEIDATA, 1,
+		          [struct path used in struct nameidata])
 	],[
-	        AC_MSG_RESULT(no)
+		AC_MSG_RESULT(no)
 	])
 ])
 
@@ -446,17 +424,17 @@ dnl #
 AC_DEFUN([SPL_AC_CTL_UNNUMBERED],
 	[AC_MSG_CHECKING([whether unnumbered sysctl support exists])
 	SPL_LINUX_TRY_COMPILE([
-	        #include <linux/sysctl.h>
+		#include <linux/sysctl.h>
 	],[
 		#ifndef CTL_UNNUMBERED
 		#error CTL_UNNUMBERED undefined
 		#endif
 	],[
-	        AC_MSG_RESULT(yes)
-	        AC_DEFINE(HAVE_CTL_UNNUMBERED, 1,
-	                  [unnumbered sysctl support exists])
+		AC_MSG_RESULT(yes)
+		AC_DEFINE(HAVE_CTL_UNNUMBERED, 1,
+		          [unnumbered sysctl support exists])
 	],[
-	        AC_MSG_RESULT(no)
+		AC_MSG_RESULT(no)
 	])
 ])
 
diff --git a/configure.ac b/configure.ac
index f32db79da..047ab89b1 100644
--- a/configure.ac
+++ b/configure.ac
@@ -44,7 +44,6 @@ SPL_AC_DEBUG_MUTEX
 SPL_AC_DEBUG_KSTAT
 SPL_AC_DEBUG_CALLB
 SPL_AC_TYPE_UINTPTR_T
-SPL_AC_ATOMIC_PANIC_NOTIFIER
 SPL_AC_3ARGS_INIT_WORK
 SPL_AC_2ARGS_REGISTER_SYSCTL
 SPL_AC_SET_SHRINKER
diff --git a/modules/spl/spl-debug.c b/modules/spl/spl-debug.c
index 99f61d74f..c6a0b52f4 100644
--- a/modules/spl/spl-debug.c
+++ b/modules/spl/spl-debug.c
@@ -40,7 +40,6 @@
 #include <linux/kthread.h>
 #include <linux/hardirq.h>
 #include <linux/interrupt.h>
-#include <linux/notifier.h>
 #include <sys/sysmacros.h>
 #include <sys/proc.h>
 #include <sys/debug.h>
@@ -108,7 +107,6 @@ char *trace_console_buffers[NR_CPUS][3];
 struct rw_semaphore trace_sem;
 atomic_t trace_tage_allocated = ATOMIC_INIT(0);
 
-static int panic_notifier(struct notifier_block *, unsigned long, void *);
 static int spl_debug_dump_all_pages(dumplog_priv_t *dp, char *);
 static void trace_fini(void);
 
@@ -120,12 +118,6 @@ static unsigned int pages_factor[TCD_TYPE_MAX] = {
        10   /* 10% pages for TCD_TYPE_IRQ */
 };
 
-static struct notifier_block spl_panic_notifier = {
-        notifier_call:   panic_notifier,
-        next:            NULL,
-        priority:        10000
-};
-
 const char *
 spl_debug_subsys2str(int subsys)
 {
@@ -1168,26 +1160,6 @@ spl_debug_mark_buffer(char *text)
 EXPORT_SYMBOL(spl_debug_mark_buffer);
 
 static int
-panic_notifier(struct notifier_block *self,
-                   unsigned long unused1, void *unused2)
-{
-        if (spl_panic_in_progress)
-                return 0;
-
-        spl_panic_in_progress = 1;
-        mb();
-
-        if (!in_interrupt()) {
-                while (current->lock_depth >= 0)
-                        unlock_kernel();
-
-                spl_debug_dumplog(DL_NOTHREAD | DL_SINGLE_CPU);
-        }
-
-        return 0;
-}
-
-static int
 trace_init(int max_pages)
 {
         struct trace_cpu_data *tcd;
@@ -1255,14 +1227,7 @@ debug_init(void)
         if (rc)
                 return rc;
 
-#ifdef HAVE_ATOMIC_PANIC_NOTIFIER
-        atomic_notifier_chain_register(&panic_notifier_list,
-                                       &spl_panic_notifier);
-#else
-        notifier_chain_register(&panic_notifier_list,
-                                &spl_panic_notifier);
-#endif
-	return rc;
+        return rc;
 }
 
 static void
@@ -1311,15 +1276,5 @@ trace_fini(void)
 void
 debug_fini(void)
 {
-#ifdef HAVE_ATOMIC_PANIC_NOTIFIER
-        atomic_notifier_chain_unregister(&panic_notifier_list,
-                                         &spl_panic_notifier);
-#else
-        notifier_chain_unregister(&panic_notifier_list,
-                                  &spl_panic_notifier);
-#endif
-
         trace_fini();
-
-	return;
 }