Merge branch 'akpm' (patches from Andrew)

Merge updates from Andrew Morton:
 "142 patches:

   - DAX updates

   - various misc bits

   - OCFS2 updates

   - most of MM"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (142 commits)
  mm/z3fold.c: limit first_num to the actual range of possible buddy indexes
  mm: fix <linux/pagemap.h> stray kernel-doc notation
  zram: remove obsolete sysfs attrs
  mm/memblock.c: remove unnecessary log and clean up
  oom-reaper: use madvise_dontneed() logic to decide if unmap the VMA
  mm: drop unused argument of zap_page_range()
  mm: drop zap_details::check_swap_entries
  mm: drop zap_details::ignore_dirty
  mm, page_alloc: warn_alloc nodemask is NULL when cpusets are disabled
  mm: help __GFP_NOFAIL allocations which do not trigger OOM killer
  mm, oom: do not enforce OOM killer for __GFP_NOFAIL automatically
  mm: consolidate GFP_NOFAIL checks in the allocator slowpath
  lib/show_mem.c: teach show_mem to work with the given nodemask
  arch, mm: remove arch specific show_mem
  mm, page_alloc: warn_alloc print nodemask
  mm, page_alloc: do not report all nodes in show_mem
  Revert "mm: bail out in shrink_inactive_list()"
  mm, vmscan: consider eligible zones in get_scan_count
  mm, vmscan: cleanup lru size claculations
  mm, vmscan: do not count freed pages as PGDEACTIVATE
  ...

2 files changed, 67 insertions, 10 deletions

diff --git a/include/uapi/asm-generic/ioctl.h b/include/uapi/asm-generic/ioctl.h
index 7e7c11b52143..749b32fe5623 100644
--- a/include/uapi/asm-generic/ioctl.h
+++ b/include/uapi/asm-generic/ioctl.h
@@ -48,6 +48,9 @@
 /*
  * Direction bits, which any architecture can choose to override
  * before including this file.
+ *
+ * NOTE: _IOC_WRITE means userland is writing and kernel is
+ * reading. _IOC_READ means userland is reading and kernel is writing.
  */
 
 #ifndef _IOC_NONE
@@ -72,7 +75,12 @@
 #define _IOC_TYPECHECK(t) (sizeof(t))
 #endif
 
-/* used to create numbers */
+/*
+ * Used to create numbers.
+ *
+ * NOTE: _IOW means userland is writing and kernel is reading. _IOR
+ * means userland is reading and kernel is writing.
+ */
 #define _IO(type,nr)		_IOC(_IOC_NONE,(type),(nr),0)
 #define _IOR(type,nr,size)	_IOC(_IOC_READ,(type),(nr),(_IOC_TYPECHECK(size)))
 #define _IOW(type,nr,size)	_IOC(_IOC_WRITE,(type),(nr),(_IOC_TYPECHECK(size)))
diff --git a/include/uapi/linux/userfaultfd.h b/include/uapi/linux/userfaultfd.h
index 9057d7af3ae1..9ac4b68c54d1 100644
--- a/include/uapi/linux/userfaultfd.h
+++ b/include/uapi/linux/userfaultfd.h
@@ -11,13 +11,18 @@
 
 #include <linux/types.h>
 
-#define UFFD_API ((__u64)0xAA)
 /*
- * After implementing the respective features it will become:
- * #define UFFD_API_FEATURES (UFFD_FEATURE_PAGEFAULT_FLAG_WP | \
- *			      UFFD_FEATURE_EVENT_FORK)
+ * If the UFFDIO_API is upgraded someday, the UFFDIO_UNREGISTER and
+ * UFFDIO_WAKE ioctls should be defined as _IOW and not as _IOR.  In
+ * userfaultfd.h we assumed the kernel was reading (instead _IOC_READ
+ * means the userland is reading).
  */
-#define UFFD_API_FEATURES (0)
+#define UFFD_API ((__u64)0xAA)
+#define UFFD_API_FEATURES (UFFD_FEATURE_EVENT_FORK |		\
+			   UFFD_FEATURE_EVENT_REMAP |		\
+			   UFFD_FEATURE_EVENT_MADVDONTNEED |	\
+			   UFFD_FEATURE_MISSING_HUGETLBFS |	\
+			   UFFD_FEATURE_MISSING_SHMEM)
 #define UFFD_API_IOCTLS				\
 	((__u64)1 << _UFFDIO_REGISTER |		\
 	 (__u64)1 << _UFFDIO_UNREGISTER |	\
@@ -26,6 +31,9 @@
 	((__u64)1 << _UFFDIO_WAKE |		\
 	 (__u64)1 << _UFFDIO_COPY |		\
 	 (__u64)1 << _UFFDIO_ZEROPAGE)
+#define UFFD_API_RANGE_IOCTLS_BASIC		\
+	((__u64)1 << _UFFDIO_WAKE |		\
+	 (__u64)1 << _UFFDIO_COPY)
 
 /*
  * Valid ioctl command number range with this API is from 0x00 to
@@ -72,6 +80,21 @@ struct uffd_msg {
 		} pagefault;
 
 		struct {
+			__u32	ufd;
+		} fork;
+
+		struct {
+			__u64	from;
+			__u64	to;
+			__u64	len;
+		} remap;
+
+		struct {
+			__u64	start;
+			__u64	end;
+		} madv_dn;
+
+		struct {
 			/* unused reserved fields */
 			__u64	reserved1;
 			__u64	reserved2;
@@ -84,9 +107,9 @@ struct uffd_msg {
  * Start at 0x12 and not at 0 to be more strict against bugs.
  */
 #define UFFD_EVENT_PAGEFAULT	0x12
-#if 0 /* not available yet */
 #define UFFD_EVENT_FORK		0x13
-#endif
+#define UFFD_EVENT_REMAP	0x14
+#define UFFD_EVENT_MADVDONTNEED	0x15
 
 /* flags for UFFD_EVENT_PAGEFAULT */
 #define UFFD_PAGEFAULT_FLAG_WRITE	(1<<0)	/* If this was a write fault */
@@ -104,11 +127,37 @@ struct uffdio_api {
 	 * Note: UFFD_EVENT_PAGEFAULT and UFFD_PAGEFAULT_FLAG_WRITE
 	 * are to be considered implicitly always enabled in all kernels as
 	 * long as the uffdio_api.api requested matches UFFD_API.
+	 *
+	 * UFFD_FEATURE_MISSING_HUGETLBFS means an UFFDIO_REGISTER
+	 * with UFFDIO_REGISTER_MODE_MISSING mode will succeed on
+	 * hugetlbfs virtual memory ranges. Adding or not adding
+	 * UFFD_FEATURE_MISSING_HUGETLBFS to uffdio_api.features has
+	 * no real functional effect after UFFDIO_API returns, but
+	 * it's only useful for an initial feature set probe at
+	 * UFFDIO_API time. There are two ways to use it:
+	 *
+	 * 1) by adding UFFD_FEATURE_MISSING_HUGETLBFS to the
+	 *    uffdio_api.features before calling UFFDIO_API, an error
+	 *    will be returned by UFFDIO_API on a kernel without
+	 *    hugetlbfs missing support
+	 *
+	 * 2) the UFFD_FEATURE_MISSING_HUGETLBFS can not be added in
+	 *    uffdio_api.features and instead it will be set by the
+	 *    kernel in the uffdio_api.features if the kernel supports
+	 *    it, so userland can later check if the feature flag is
+	 *    present in uffdio_api.features after UFFDIO_API
+	 *    succeeded.
+	 *
+	 * UFFD_FEATURE_MISSING_SHMEM works the same as
+	 * UFFD_FEATURE_MISSING_HUGETLBFS, but it applies to shmem
+	 * (i.e. tmpfs and other shmem based APIs).
 	 */
-#if 0 /* not available yet */
 #define UFFD_FEATURE_PAGEFAULT_FLAG_WP		(1<<0)
 #define UFFD_FEATURE_EVENT_FORK			(1<<1)
-#endif
+#define UFFD_FEATURE_EVENT_REMAP		(1<<2)
+#define UFFD_FEATURE_EVENT_MADVDONTNEED		(1<<3)
+#define UFFD_FEATURE_MISSING_HUGETLBFS		(1<<4)
+#define UFFD_FEATURE_MISSING_SHMEM		(1<<5)
 	__u64 features;
 
 	__u64 ioctls;