Merge branch 'linus' into core/rcu

Conflicts:
	fs/fs-writeback.c

Merge reason: Resolve the conflict

Note, i picked the version from Linus's tree, which effectively reverts
the fs-writeback.c bits of:

  b97181f: fs: remove all rcu head initializations, except on_stack initializations

As the upstream changes to this file changed this code heavily and the
first attempt to resolve the conflict resulted in a non-booting kernel.
It's safer to re-try this portion of the commit cleanly.

Signed-off-by: Ingo Molnar <mingo@elte.hu>

8 files changed, 59 insertions, 23 deletions

diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h
index aee5f6ce166e..9ae2889096b6 100644
--- a/include/linux/backing-dev.h
+++ b/include/linux/backing-dev.h
@@ -105,8 +105,8 @@ int bdi_register(struct backing_dev_info *bdi, struct device *parent,
 int bdi_register_dev(struct backing_dev_info *bdi, dev_t dev);
 void bdi_unregister(struct backing_dev_info *bdi);
 int bdi_setup_and_register(struct backing_dev_info *, char *, unsigned int);
-void bdi_start_writeback(struct backing_dev_info *bdi, struct super_block *sb,
-                                long nr_pages);
+void bdi_start_writeback(struct backing_dev_info *bdi, long nr_pages);
+void bdi_start_background_writeback(struct backing_dev_info *bdi);
 int bdi_writeback_task(struct bdi_writeback *wb);
 int bdi_has_dirty_io(struct backing_dev_info *bdi);
 void bdi_arm_supers_timer(void);
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 0c621604baa1..e3d00fdb858d 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -525,13 +525,21 @@ static inline struct cgroup_subsys_state *cgroup_subsys_state(
         return cgrp->subsys[subsys_id];
 }
 
-static inline struct cgroup_subsys_state *task_subsys_state(
-        struct task_struct *task, int subsys_id)
+/*
+ * function to get the cgroup_subsys_state which allows for extra
+ * rcu_dereference_check() conditions, such as locks used during the
+ * cgroup_subsys::attach() methods.
+ */
+#define task_subsys_state_check(task, subsys_id, __c)                   \
+        rcu_dereference_check(task->cgroups->subsys[subsys_id],         \
+                              rcu_read_lock_held() ||                   \
+                              lockdep_is_held(&task->alloc_lock) ||     \
+                              cgroup_lock_is_held() || (__c))
+
+static inline struct cgroup_subsys_state *
+task_subsys_state(struct task_struct *task, int subsys_id)
 {
-        return rcu_dereference_check(task->cgroups->subsys[subsys_id],
-                                     rcu_read_lock_held() ||
-                                     lockdep_is_held(&task->alloc_lock) ||
-                                     cgroup_lock_is_held());
+        return task_subsys_state_check(task, subsys_id, false);
 }
 
 static inline struct cgroup* task_cgroup(struct task_struct *task,
diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
index 73dcf804bc94..0da5b187f124 100644
--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -58,8 +58,12 @@
  * naked functions because then mcount is called without stack and frame pointer
  * being set up and there is no chance to restore the lr register to the value
  * before mcount was called.
+ *
+ * The asm() bodies of naked functions often depend on standard calling conventions,
+ * therefore they must be noinline and noclone.  GCC 4.[56] currently fail to enforce
+ * this, so we must do so ourselves.  See GCC PR44290.
  */
-#define __naked                         __attribute__((naked)) notrace
+#define __naked                         __attribute__((naked)) noinline __noclone notrace
 
 #define __noreturn                      __attribute__((noreturn))
 
@@ -85,3 +89,7 @@
 #define _gcc_header(x) __gcc_header(linux/compiler-gcc##x.h)
 #define gcc_header(x) _gcc_header(x)
 #include gcc_header(__GNUC__)
+
+#if !defined(__noclone)
+#define __noclone       /* not needed */
+#endif
diff --git a/include/linux/compiler-gcc4.h b/include/linux/compiler-gcc4.h
index 94dea3ffbfa1..fcfa5b9a4317 100644
--- a/include/linux/compiler-gcc4.h
+++ b/include/linux/compiler-gcc4.h
@@ -48,6 +48,10 @@
  * unreleased.  Really, we need to have autoconf for the kernel.
  */
 #define unreachable() __builtin_unreachable()
+
+/* Mark a function definition as prohibited from being cloned. */
+#define __noclone       __attribute__((__noclone__))
+
 #endif
 
 #endif
diff --git a/include/linux/drbd.h b/include/linux/drbd.h
index 30da4ae48972..b8d2516668aa 100644
--- a/include/linux/drbd.h
+++ b/include/linux/drbd.h
@@ -53,7 +53,7 @@
 
 
 extern const char *drbd_buildtag(void);
-#define REL_VERSION "8.3.8rc2"
+#define REL_VERSION "8.3.8"
 #define API_VERSION 88
 #define PRO_VERSION_MIN 86
 #define PRO_VERSION_MAX 94
diff --git a/include/linux/list.h b/include/linux/list.h
index 8392884a2977..5d57a3a1fa1b 100644
--- a/include/linux/list.h
+++ b/include/linux/list.h
@@ -544,6 +544,21 @@ static inline void list_splice_tail_init(struct list_head *list,
              &pos->member != (head);                                    \
              pos = n, n = list_entry(n->member.prev, typeof(*n), member))
 
+/**
+ * list_safe_reset_next - reset a stale list_for_each_entry_safe loop
+ * @pos:        the loop cursor used in the list_for_each_entry_safe loop
+ * @n:          temporary storage used in list_for_each_entry_safe
+ * @member:     the name of the list_struct within the struct.
+ *
+ * list_safe_reset_next is not safe to use in general if the list may be
+ * modified concurrently (eg. the lock is dropped in the loop body). An
+ * exception to this is if the cursor element (pos) is pinned in the list,
+ * and list_safe_reset_next is called after re-taking the lock and before
+ * completing the current iteration of the loop body.
+ */
+#define list_safe_reset_next(pos, n, member)                            \
+        n = list_entry(pos->member.next, typeof(*pos), member)
+
 /*
  * Double linked lists with a single pointer list head.
  * Mostly useful for hash tables where the two pointer list head is
diff --git a/include/linux/suspend.h b/include/linux/suspend.h
index 5e781d824e6d..bc7d6bb4cd8e 100644
--- a/include/linux/suspend.h
+++ b/include/linux/suspend.h
@@ -256,22 +256,22 @@ static inline int hibernate(void) { return -ENOSYS; }
 static inline bool system_entering_hibernation(void) { return false; }
 #endif /* CONFIG_HIBERNATION */
 
-#ifdef CONFIG_HIBERNATION_NVS
-extern int hibernate_nvs_register(unsigned long start, unsigned long size);
-extern int hibernate_nvs_alloc(void);
-extern void hibernate_nvs_free(void);
-extern void hibernate_nvs_save(void);
-extern void hibernate_nvs_restore(void);
-#else /* CONFIG_HIBERNATION_NVS */
-static inline int hibernate_nvs_register(unsigned long a, unsigned long b)
+#ifdef CONFIG_SUSPEND_NVS
+extern int suspend_nvs_register(unsigned long start, unsigned long size);
+extern int suspend_nvs_alloc(void);
+extern void suspend_nvs_free(void);
+extern void suspend_nvs_save(void);
+extern void suspend_nvs_restore(void);
+#else /* CONFIG_SUSPEND_NVS */
+static inline int suspend_nvs_register(unsigned long a, unsigned long b)
 {
         return 0;
 }
-static inline int hibernate_nvs_alloc(void) { return 0; }
-static inline void hibernate_nvs_free(void) {}
-static inline void hibernate_nvs_save(void) {}
-static inline void hibernate_nvs_restore(void) {}
-#endif /* CONFIG_HIBERNATION_NVS */
+static inline int suspend_nvs_alloc(void) { return 0; }
+static inline void suspend_nvs_free(void) {}
+static inline void suspend_nvs_save(void) {}
+static inline void suspend_nvs_restore(void) {}
+#endif /* CONFIG_SUSPEND_NVS */
 
 #ifdef CONFIG_PM_SLEEP
 void save_processor_state(void);
diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
index 9a59d1f98cd4..103d1b61aacb 100644
--- a/include/linux/tracepoint.h
+++ b/include/linux/tracepoint.h
@@ -14,6 +14,7 @@
  * See the file COPYING for more details.
  */
 
+#include <linux/errno.h>
 #include <linux/types.h>
 #include <linux/rcupdate.h>