[kdbus] Import iov_iter_init & iov_iter_kvec from Linux 4.0

These 2 functions are used by kdbus/pool.c and backporting patches that
adds desired functions (with dependencies) would introduce too many
changes for 3.10.

Change-Id: Ic617cc53c98eb18c15110605d577c1ed672c0153
Signed-off-by: Maciej Wereski <m.wereski@partner.samsung.com>

9 files changed, 3374 insertions, 1 deletions

diff --git a/Makefile b/Makefile
index 02a2eb4dc98..bf344cf3e9d 100644
--- a/Makefile
+++ b/Makefile
@@ -523,6 +523,7 @@ drivers-y	:= drivers/ sound/ firmware/
 net-y		:= net/
 libs-y		:= lib/
 core-y		:= usr/
+compat-y	:= compat/
 endif # KBUILD_EXTMOD
 
 ifeq ($(dot-config),1)
@@ -738,15 +739,18 @@ ifeq ($(KBUILD_EXTMOD),)
 core-y		+= kernel/ mm/ fs/ ipc/ security/ crypto/ block/
 
 vmlinux-dirs	:= $(patsubst %/,%,$(filter %/, $(init-y) $(init-m) \
+		     $(compat-y) $(compat-m) \
 		     $(core-y) $(core-m) $(drivers-y) $(drivers-m) \
 		     $(net-y) $(net-m) $(libs-y) $(libs-m)))
 
 vmlinux-alldirs	:= $(sort $(vmlinux-dirs) $(patsubst %/,%,$(filter %/, \
 		     $(init-n) $(init-) \
+		     $(compat-n) $(compat-) \
 		     $(core-n) $(core-) $(drivers-n) $(drivers-) \
 		     $(net-n)  $(net-)  $(libs-n)    $(libs-))))
 
 init-y		:= $(patsubst %/, %/built-in.o, $(init-y))
+compat-y	:= $(patsubst %/, %/built-in.o, $(compat-y))
 core-y		:= $(patsubst %/, %/built-in.o, $(core-y))
 drivers-y	:= $(patsubst %/, %/built-in.o, $(drivers-y))
 net-y		:= $(patsubst %/, %/built-in.o, $(net-y))
@@ -756,7 +760,7 @@ libs-y		:= $(libs-y1) $(libs-y2)
 
 # Externally visible symbols (used by link-vmlinux.sh)
 export KBUILD_VMLINUX_INIT := $(head-y) $(init-y)
-export KBUILD_VMLINUX_MAIN := $(core-y) $(libs-y) $(drivers-y) $(net-y)
+export KBUILD_VMLINUX_MAIN := $(compat-y) $(core-y) $(libs-y) $(drivers-y) $(net-y)
 export KBUILD_LDS          := arch/$(SRCARCH)/kernel/vmlinux.lds
 export LDFLAGS_vmlinux
 # used by scripts/pacmage/Makefile
diff --git a/compat/Makefile b/compat/Makefile
new file mode 100644
index 00000000000..35a2017a7d4
--- /dev/null
+++ b/compat/Makefile
@@ -0,0 +1,4 @@
+ifdef CONFIG_KDBUS
+override LINUXINCLUDE := $(patsubst -Iinclude, -Icompat/include -Iinclude , $(LINUXINCLUDE))
+obj-y += lib/
+endif
diff --git a/compat/include/linux/fs.h b/compat/include/linux/fs.h
new file mode 100644
index 00000000000..52cc4492cb3
--- /dev/null
+++ b/compat/include/linux/fs.h
@@ -0,0 +1,2921 @@
+#ifndef _LINUX_FS_H
+#define _LINUX_FS_H
+
+
+#include <linux/linkage.h>
+#include <linux/wait.h>
+#include <linux/kdev_t.h>
+#include <linux/dcache.h>
+#include <linux/path.h>
+#include <linux/stat.h>
+#include <linux/cache.h>
+#include <linux/list.h>
+#include <linux/list_lru.h>
+#include <linux/llist.h>
+#include <linux/radix-tree.h>
+#include <linux/rbtree.h>
+#include <linux/init.h>
+#include <linux/pid.h>
+#include <linux/bug.h>
+#include <linux/mutex.h>
+#include <linux/rwsem.h>
+#include <linux/capability.h>
+#include <linux/semaphore.h>
+#include <linux/fiemap.h>
+#include <linux/rculist_bl.h>
+#include <linux/atomic.h>
+#include <linux/shrinker.h>
+#include <linux/migrate_mode.h>
+#include <linux/uidgid.h>
+#include <linux/lockdep.h>
+#include <linux/percpu-rwsem.h>
+#include <linux/blk_types.h>
+
+#include <asm/byteorder.h>
+#include <uapi/linux/fs.h>
+
+struct backing_dev_info;
+struct export_operations;
+struct hd_geometry;
+struct iovec;
+struct nameidata;
+struct kiocb;
+struct kobject;
+struct pipe_inode_info;
+struct poll_table_struct;
+struct kstatfs;
+struct vm_area_struct;
+struct vfsmount;
+struct cred;
+struct swap_info_struct;
+struct seq_file;
+struct workqueue_struct;
+struct iov_iter;
+struct vm_fault;
+
+extern void __init inode_init(void);
+extern void __init inode_init_early(void);
+extern void __init files_init(unsigned long);
+
+extern struct files_stat_struct files_stat;
+extern unsigned long get_max_files(void);
+extern int sysctl_nr_open;
+extern struct inodes_stat_t inodes_stat;
+extern int leases_enable, lease_break_time;
+extern int sysctl_protected_symlinks;
+extern int sysctl_protected_hardlinks;
+
+struct buffer_head;
+typedef int (get_block_t)(struct inode *inode, sector_t iblock,
+			struct buffer_head *bh_result, int create);
+typedef void (dio_iodone_t)(struct kiocb *iocb, loff_t offset,
+			ssize_t bytes, void *private);
+
+#define MAY_EXEC		0x00000001
+#define MAY_WRITE		0x00000002
+#define MAY_READ		0x00000004
+#define MAY_APPEND		0x00000008
+#define MAY_ACCESS		0x00000010
+#define MAY_OPEN		0x00000020
+#define MAY_CHDIR		0x00000040
+/* called from RCU mode, don't block */
+#define MAY_NOT_BLOCK		0x00000080
+
+/*
+ * flags in file.f_mode.  Note that FMODE_READ and FMODE_WRITE must correspond
+ * to O_WRONLY and O_RDWR via the strange trick in __dentry_open()
+ */
+
+/* file is open for reading */
+#define FMODE_READ		((__force fmode_t)0x1)
+/* file is open for writing */
+#define FMODE_WRITE		((__force fmode_t)0x2)
+/* file is seekable */
+#define FMODE_LSEEK		((__force fmode_t)0x4)
+/* file can be accessed using pread */
+#define FMODE_PREAD		((__force fmode_t)0x8)
+/* file can be accessed using pwrite */
+#define FMODE_PWRITE		((__force fmode_t)0x10)
+/* File is opened for execution with sys_execve / sys_uselib */
+#define FMODE_EXEC		((__force fmode_t)0x20)
+/* File is opened with O_NDELAY (only set for block devices) */
+#define FMODE_NDELAY		((__force fmode_t)0x40)
+/* File is opened with O_EXCL (only set for block devices) */
+#define FMODE_EXCL		((__force fmode_t)0x80)
+/* File is opened using open(.., 3, ..) and is writeable only for ioctls
+   (specialy hack for floppy.c) */
+#define FMODE_WRITE_IOCTL	((__force fmode_t)0x100)
+/* 32bit hashes as llseek() offset (for directories) */
+#define FMODE_32BITHASH         ((__force fmode_t)0x200)
+/* 64bit hashes as llseek() offset (for directories) */
+#define FMODE_64BITHASH         ((__force fmode_t)0x400)
+
+/*
+ * Don't update ctime and mtime.
+ *
+ * Currently a special hack for the XFS open_by_handle ioctl, but we'll
+ * hopefully graduate it to a proper O_CMTIME flag supported by open(2) soon.
+ */
+#define FMODE_NOCMTIME		((__force fmode_t)0x800)
+
+/* Expect random access pattern */
+#define FMODE_RANDOM		((__force fmode_t)0x1000)
+
+/* File is huge (eg. /dev/kmem): treat loff_t as unsigned */
+#define FMODE_UNSIGNED_OFFSET	((__force fmode_t)0x2000)
+
+/* File is opened with O_PATH; almost nothing can be done with it */
+#define FMODE_PATH		((__force fmode_t)0x4000)
+
+/* File needs atomic accesses to f_pos */
+#define FMODE_ATOMIC_POS	((__force fmode_t)0x8000)
+/* Write access to underlying fs */
+#define FMODE_WRITER		((__force fmode_t)0x10000)
+/* Has read method(s) */
+#define FMODE_CAN_READ          ((__force fmode_t)0x20000)
+/* Has write method(s) */
+#define FMODE_CAN_WRITE         ((__force fmode_t)0x40000)
+
+/* File was opened by fanotify and shouldn't generate fanotify events */
+#define FMODE_NONOTIFY		((__force fmode_t)0x4000000)
+
+/*
+ * Flag for rw_copy_check_uvector and compat_rw_copy_check_uvector
+ * that indicates that they should check the contents of the iovec are
+ * valid, but not check the memory that the iovec elements
+ * points too.
+ */
+#define CHECK_IOVEC_ONLY -1
+
+/*
+ * The below are the various read and write types that we support. Some of
+ * them include behavioral modifiers that send information down to the
+ * block layer and IO scheduler. Terminology:
+ *
+ *	The block layer uses device plugging to defer IO a little bit, in
+ *	the hope that we will see more IO very shortly. This increases
+ *	coalescing of adjacent IO and thus reduces the number of IOs we
+ *	have to send to the device. It also allows for better queuing,
+ *	if the IO isn't mergeable. If the caller is going to be waiting
+ *	for the IO, then he must ensure that the device is unplugged so
+ *	that the IO is dispatched to the driver.
+ *
+ *	All IO is handled async in Linux. This is fine for background
+ *	writes, but for reads or writes that someone waits for completion
+ *	on, we want to notify the block layer and IO scheduler so that they
+ *	know about it. That allows them to make better scheduling
+ *	decisions. So when the below references 'sync' and 'async', it
+ *	is referencing this priority hint.
+ *
+ * With that in mind, the available types are:
+ *
+ * READ			A normal read operation. Device will be plugged.
+ * READ_SYNC		A synchronous read. Device is not plugged, caller can
+ *			immediately wait on this read without caring about
+ *			unplugging.
+ * READA		Used for read-ahead operations. Lower priority, and the
+ *			block layer could (in theory) choose to ignore this
+ *			request if it runs into resource problems.
+ * WRITE		A normal async write. Device will be plugged.
+ * WRITE_SYNC		Synchronous write. Identical to WRITE, but passes down
+ *			the hint that someone will be waiting on this IO
+ *			shortly. The write equivalent of READ_SYNC.
+ * WRITE_ODIRECT	Special case write for O_DIRECT only.
+ * WRITE_FLUSH		Like WRITE_SYNC but with preceding cache flush.
+ * WRITE_FUA		Like WRITE_SYNC but data is guaranteed to be on
+ *			non-volatile media on completion.
+ * WRITE_FLUSH_FUA	Combination of WRITE_FLUSH and FUA. The IO is preceded
+ *			by a cache flush and data is guaranteed to be on
+ *			non-volatile media on completion.
+ *
+ */
+#define RW_MASK			REQ_WRITE
+#define RWA_MASK		REQ_RAHEAD
+
+#define READ			0
+#define WRITE			RW_MASK
+#define READA			RWA_MASK
+
+#define READ_SYNC		(READ | REQ_SYNC)
+#define WRITE_SYNC		(WRITE | REQ_SYNC | REQ_NOIDLE)
+#define WRITE_ODIRECT		(WRITE | REQ_SYNC)
+#define WRITE_FLUSH		(WRITE | REQ_SYNC | REQ_NOIDLE | REQ_FLUSH)
+#define WRITE_FUA		(WRITE | REQ_SYNC | REQ_NOIDLE | REQ_FUA)
+#define WRITE_FLUSH_FUA		(WRITE | REQ_SYNC | REQ_NOIDLE | REQ_FLUSH | REQ_FUA)
+
+/*
+ * Attribute flags.  These should be or-ed together to figure out what
+ * has been changed!
+ */
+#define ATTR_MODE	(1 << 0)
+#define ATTR_UID	(1 << 1)
+#define ATTR_GID	(1 << 2)
+#define ATTR_SIZE	(1 << 3)
+#define ATTR_ATIME	(1 << 4)
+#define ATTR_MTIME	(1 << 5)
+#define ATTR_CTIME	(1 << 6)
+#define ATTR_ATIME_SET	(1 << 7)
+#define ATTR_MTIME_SET	(1 << 8)
+#define ATTR_FORCE	(1 << 9) /* Not a change, but a change it */
+#define ATTR_ATTR_FLAG	(1 << 10)
+#define ATTR_KILL_SUID	(1 << 11)
+#define ATTR_KILL_SGID	(1 << 12)
+#define ATTR_FILE	(1 << 13)
+#define ATTR_KILL_PRIV	(1 << 14)
+#define ATTR_OPEN	(1 << 15) /* Truncating from open(O_TRUNC) */
+#define ATTR_TIMES_SET	(1 << 16)
+
+/*
+ * Whiteout is represented by a char device.  The following constants define the
+ * mode and device number to use.
+ */
+#define WHITEOUT_MODE 0
+#define WHITEOUT_DEV 0
+
+/*
+ * This is the Inode Attributes structure, used for notify_change().  It
+ * uses the above definitions as flags, to know which values have changed.
+ * Also, in this manner, a Filesystem can look at only the values it cares
+ * about.  Basically, these are the attributes that the VFS layer can
+ * request to change from the FS layer.
+ *
+ * Derek Atkins <warlord@MIT.EDU> 94-10-20
+ */
+struct iattr {
+	unsigned int	ia_valid;
+	umode_t		ia_mode;
+	kuid_t		ia_uid;
+	kgid_t		ia_gid;
+	loff_t		ia_size;
+	struct timespec	ia_atime;
+	struct timespec	ia_mtime;
+	struct timespec	ia_ctime;
+
+	/*
+	 * Not an attribute, but an auxiliary info for filesystems wanting to
+	 * implement an ftruncate() like method.  NOTE: filesystem should
+	 * check for (ia_valid & ATTR_FILE), and not for (ia_file != NULL).
+	 */
+	struct file	*ia_file;
+};
+
+/*
+ * Includes for diskquotas.
+ */
+#include <linux/quota.h>
+
+/*
+ * Maximum number of layers of fs stack.  Needs to be limited to
+ * prevent kernel stack overflow
+ */
+#define FILESYSTEM_MAX_STACK_DEPTH 2
+
+/** 
+ * enum positive_aop_returns - aop return codes with specific semantics
+ *
+ * @AOP_WRITEPAGE_ACTIVATE: Informs the caller that page writeback has
+ * 			    completed, that the page is still locked, and
+ * 			    should be considered active.  The VM uses this hint
+ * 			    to return the page to the active list -- it won't
+ * 			    be a candidate for writeback again in the near
+ * 			    future.  Other callers must be careful to unlock
+ * 			    the page if they get this return.  Returned by
+ * 			    writepage(); 
+ *
+ * @AOP_TRUNCATED_PAGE: The AOP method that was handed a locked page has
+ *  			unlocked it and the page might have been truncated.
+ *  			The caller should back up to acquiring a new page and
+ *  			trying again.  The aop will be taking reasonable
+ *  			precautions not to livelock.  If the caller held a page
+ *  			reference, it should drop it before retrying.  Returned
+ *  			by readpage().
+ *
+ * address_space_operation functions return these large constants to indicate
+ * special semantics to the caller.  These are much larger than the bytes in a
+ * page to allow for functions that return the number of bytes operated on in a
+ * given page.
+ */
+
+enum positive_aop_returns {
+	AOP_WRITEPAGE_ACTIVATE	= 0x80000,
+	AOP_TRUNCATED_PAGE	= 0x80001,
+};
+
+#define AOP_FLAG_UNINTERRUPTIBLE	0x0001 /* will not do a short write */
+#define AOP_FLAG_CONT_EXPAND		0x0002 /* called from cont_expand */
+#define AOP_FLAG_NOFS			0x0004 /* used by filesystem to direct
+						* helper code (eg buffer layer)
+						* to clear GFP_FS from alloc */
+
+/*
+ * oh the beauties of C type declarations.
+ */
+struct page;
+struct address_space;
+struct writeback_control;
+
+/*
+ * "descriptor" for what we're up to with a read.
+ * This allows us to use the same read code yet
+ * have multiple different users of the data that
+ * we read from a file.
+ *
+ * The simplest case just copies the data to user
+ * mode.
+ */
+typedef struct {
+	size_t written;
+	size_t count;
+	union {
+		char __user *buf;
+		void *data;
+	} arg;
+	int error;
+} read_descriptor_t;
+
+typedef int (*read_actor_t)(read_descriptor_t *, struct page *,
+		unsigned long, unsigned long);
+
+struct address_space_operations {
+	int (*writepage)(struct page *page, struct writeback_control *wbc);
+	int (*readpage)(struct file *, struct page *);
+
+	/* Write back some dirty pages from this mapping. */
+	int (*writepages)(struct address_space *, struct writeback_control *);
+
+	/* Set a page dirty.  Return true if this dirtied it */
+	int (*set_page_dirty)(struct page *page);
+
+	int (*readpages)(struct file *filp, struct address_space *mapping,
+			struct list_head *pages, unsigned nr_pages);
+
+	int (*write_begin)(struct file *, struct address_space *mapping,
+				loff_t pos, unsigned len, unsigned flags,
+				struct page **pagep, void **fsdata);
+	int (*write_end)(struct file *, struct address_space *mapping,
+				loff_t pos, unsigned len, unsigned copied,
+				struct page *page, void *fsdata);
+
+	/* Unfortunately this kludge is needed for FIBMAP. Don't use it */
+	sector_t (*bmap)(struct address_space *, sector_t);
+	void (*invalidatepage) (struct page *, unsigned int, unsigned int);
+	int (*releasepage) (struct page *, gfp_t);
+	void (*freepage)(struct page *);
+	ssize_t (*direct_IO)(int, struct kiocb *, struct iov_iter *iter, loff_t offset);
+	/*
+	 * migrate the contents of a page to the specified target. If
+	 * migrate_mode is MIGRATE_ASYNC, it must not block.
+	 */
+	int (*migratepage) (struct address_space *,
+			struct page *, struct page *, enum migrate_mode);
+	int (*launder_page) (struct page *);
+	int (*is_partially_uptodate) (struct page *, unsigned long,
+					unsigned long);
+	void (*is_dirty_writeback) (struct page *, bool *, bool *);
+	int (*error_remove_page)(struct address_space *, struct page *);
+
+	/* swapfile support */
+	int (*swap_activate)(struct swap_info_struct *sis, struct file *file,
+				sector_t *span);
+	void (*swap_deactivate)(struct file *file);
+};
+
+extern const struct address_space_operations empty_aops;
+
+/*
+ * pagecache_write_begin/pagecache_write_end must be used by general code
+ * to write into the pagecache.
+ */
+int pagecache_write_begin(struct file *, struct address_space *mapping,
+				loff_t pos, unsigned len, unsigned flags,
+				struct page **pagep, void **fsdata);
+
+int pagecache_write_end(struct file *, struct address_space *mapping,
+				loff_t pos, unsigned len, unsigned copied,
+				struct page *page, void *fsdata);
+
+struct address_space {
+	struct inode		*host;		/* owner: inode, block_device */
+	struct radix_tree_root	page_tree;	/* radix tree of all pages */
+	spinlock_t		tree_lock;	/* and lock protecting it */
+	atomic_t		i_mmap_writable;/* count VM_SHARED mappings */
+	struct rb_root		i_mmap;		/* tree of private and shared mappings */
+	struct rw_semaphore	i_mmap_rwsem;	/* protect tree, count, list */
+	/* Protected by tree_lock together with the radix tree */
+	unsigned long		nrpages;	/* number of total pages */
+	unsigned long		nrshadows;	/* number of shadow entries */
+	pgoff_t			writeback_index;/* writeback starts here */
+	const struct address_space_operations *a_ops;	/* methods */
+	unsigned long		flags;		/* error bits/gfp mask */
+	spinlock_t		private_lock;	/* for use by the address_space */
+	struct list_head	private_list;	/* ditto */
+	void			*private_data;	/* ditto */
+} __attribute__((aligned(sizeof(long))));
+	/*
+	 * On most architectures that alignment is already the case; but
+	 * must be enforced here for CRIS, to let the least significant bit
+	 * of struct page's "mapping" pointer be used for PAGE_MAPPING_ANON.
+	 */
+struct request_queue;
+
+struct block_device {
+	dev_t			bd_dev;  /* not a kdev_t - it's a search key */
+	int			bd_openers;
+	struct inode *		bd_inode;	/* will die */
+	struct super_block *	bd_super;
+	struct mutex		bd_mutex;	/* open/close mutex */
+	struct list_head	bd_inodes;
+	void *			bd_claiming;
+	void *			bd_holder;
+	int			bd_holders;
+	bool			bd_write_holder;
+#ifdef CONFIG_SYSFS
+	struct list_head	bd_holder_disks;
+#endif
+	struct block_device *	bd_contains;
+	unsigned		bd_block_size;
+	struct hd_struct *	bd_part;
+	/* number of times partitions within this device have been opened. */
+	unsigned		bd_part_count;
+	int			bd_invalidated;
+	struct gendisk *	bd_disk;
+	struct request_queue *  bd_queue;
+	struct list_head	bd_list;
+	/*
+	 * Private data.  You must have bd_claim'ed the block_device
+	 * to use this.  NOTE:  bd_claim allows an owner to claim
+	 * the same device multiple times, the owner must take special
+	 * care to not mess up bd_private for that case.
+	 */
+	unsigned long		bd_private;
+
+	/* The counter of freeze processes */
+	int			bd_fsfreeze_count;
+	/* Mutex for freeze */
+	struct mutex		bd_fsfreeze_mutex;
+};
+
+/*
+ * Radix-tree tags, for tagging dirty and writeback pages within the pagecache
+ * radix trees
+ */
+#define PAGECACHE_TAG_DIRTY	0
+#define PAGECACHE_TAG_WRITEBACK	1
+#define PAGECACHE_TAG_TOWRITE	2
+
+int mapping_tagged(struct address_space *mapping, int tag);
+
+static inline void i_mmap_lock_write(struct address_space *mapping)
+{
+	down_write(&mapping->i_mmap_rwsem);
+}
+
+static inline void i_mmap_unlock_write(struct address_space *mapping)
+{
+	up_write(&mapping->i_mmap_rwsem);
+}
+
+static inline void i_mmap_lock_read(struct address_space *mapping)
+{
+	down_read(&mapping->i_mmap_rwsem);
+}
+
+static inline void i_mmap_unlock_read(struct address_space *mapping)
+{
+	up_read(&mapping->i_mmap_rwsem);
+}
+
+/*
+ * Might pages of this file be mapped into userspace?
+ */
+static inline int mapping_mapped(struct address_space *mapping)
+{
+	return	!RB_EMPTY_ROOT(&mapping->i_mmap);
+}
+
+/*
+ * Might pages of this file have been modified in userspace?
+ * Note that i_mmap_writable counts all VM_SHARED vmas: do_mmap_pgoff
+ * marks vma as VM_SHARED if it is shared, and the file was opened for
+ * writing i.e. vma may be mprotected writable even if now readonly.
+ *
+ * If i_mmap_writable is negative, no new writable mappings are allowed. You
+ * can only deny writable mappings, if none exists right now.
+ */
+static inline int mapping_writably_mapped(struct address_space *mapping)
+{
+	return atomic_read(&mapping->i_mmap_writable) > 0;
+}
+
+static inline int mapping_map_writable(struct address_space *mapping)
+{
+	return atomic_inc_unless_negative(&mapping->i_mmap_writable) ?
+		0 : -EPERM;
+}
+
+static inline void mapping_unmap_writable(struct address_space *mapping)
+{
+	atomic_dec(&mapping->i_mmap_writable);
+}
+
+static inline int mapping_deny_writable(struct address_space *mapping)
+{
+	return atomic_dec_unless_positive(&mapping->i_mmap_writable) ?
+		0 : -EBUSY;
+}
+
+static inline void mapping_allow_writable(struct address_space *mapping)
+{
+	atomic_inc(&mapping->i_mmap_writable);
+}
+
+/*
+ * Use sequence counter to get consistent i_size on 32-bit processors.
+ */
+#if BITS_PER_LONG==32 && defined(CONFIG_SMP)
+#include <linux/seqlock.h>
+#define __NEED_I_SIZE_ORDERED
+#define i_size_ordered_init(inode) seqcount_init(&inode->i_size_seqcount)
+#else
+#define i_size_ordered_init(inode) do { } while (0)
+#endif
+
+struct posix_acl;
+#define ACL_NOT_CACHED ((void *)(-1))
+
+#define IOP_FASTPERM	0x0001
+#define IOP_LOOKUP	0x0002
+#define IOP_NOFOLLOW	0x0004
+
+/*
+ * Keep mostly read-only and often accessed (especially for
+ * the RCU path lookup and 'stat' data) fields at the beginning
+ * of the 'struct inode'
+ */
+struct inode {
+	umode_t			i_mode;
+	unsigned short		i_opflags;
+	kuid_t			i_uid;
+	kgid_t			i_gid;
+	unsigned int		i_flags;
+
+#ifdef CONFIG_FS_POSIX_ACL
+	struct posix_acl	*i_acl;
+	struct posix_acl	*i_default_acl;
+#endif
+
+	const struct inode_operations	*i_op;
+	struct super_block	*i_sb;
+	struct address_space	*i_mapping;
+
+#ifdef CONFIG_SECURITY
+	void			*i_security;
+#endif
+
+	/* Stat data, not accessed from path walking */
+	unsigned long		i_ino;
+	/*
+	 * Filesystems may only read i_nlink directly.  They shall use the
+	 * following functions for modification:
+	 *
+	 *    (set|clear|inc|drop)_nlink
+	 *    inode_(inc|dec)_link_count
+	 */
+	union {
+		const unsigned int i_nlink;
+		unsigned int __i_nlink;
+	};
+	dev_t			i_rdev;
+	loff_t			i_size;
+	struct timespec		i_atime;
+	struct timespec		i_mtime;
+	struct timespec		i_ctime;
+	spinlock_t		i_lock;	/* i_blocks, i_bytes, maybe i_size */
+	unsigned short          i_bytes;
+	unsigned int		i_blkbits;
+	blkcnt_t		i_blocks;
+
+#ifdef __NEED_I_SIZE_ORDERED
+	seqcount_t		i_size_seqcount;
+#endif
+
+	/* Misc */
+	unsigned long		i_state;
+	struct mutex		i_mutex;
+
+	unsigned long		dirtied_when;	/* jiffies of first dirtying */
+	unsigned long		dirtied_time_when;
+
+	struct hlist_node	i_hash;
+	struct list_head	i_wb_list;	/* backing dev IO list */
+	struct list_head	i_lru;		/* inode LRU list */
+	struct list_head	i_sb_list;
+	union {
+		struct hlist_head	i_dentry;
+		struct rcu_head		i_rcu;
+	};
+	u64			i_version;
+	atomic_t		i_count;
+	atomic_t		i_dio_count;
+	atomic_t		i_writecount;
+#ifdef CONFIG_IMA
+	atomic_t		i_readcount; /* struct files open RO */
+#endif
+	const struct file_operations	*i_fop;	/* former ->i_op->default_file_ops */
+	struct file_lock_context	*i_flctx;
+	struct address_space	i_data;
+	struct list_head	i_devices;
+	union {
+		struct pipe_inode_info	*i_pipe;
+		struct block_device	*i_bdev;
+		struct cdev		*i_cdev;
+	};
+
+	__u32			i_generation;
+
+#ifdef CONFIG_FSNOTIFY
+	__u32			i_fsnotify_mask; /* all events this inode cares about */
+	struct hlist_head	i_fsnotify_marks;
+#endif
+
+	void			*i_private; /* fs or device private pointer */
+};
+
+static inline int inode_unhashed(struct inode *inode)
+{
+	return hlist_unhashed(&inode->i_hash);
+}
+
+/*
+ * inode->i_mutex nesting subclasses for the lock validator:
+ *
+ * 0: the object of the current VFS operation
+ * 1: parent
+ * 2: child/target
+ * 3: xattr
+ * 4: second non-directory
+ * 5: second parent (when locking independent directories in rename)
+ *
+ * I_MUTEX_NONDIR2 is for certain operations (such as rename) which lock two
+ * non-directories at once.
+ *
+ * The locking order between these classes is
+ * parent[2] -> child -> grandchild -> normal -> xattr -> second non-directory
+ */
+enum inode_i_mutex_lock_class
+{
+	I_MUTEX_NORMAL,
+	I_MUTEX_PARENT,
+	I_MUTEX_CHILD,
+	I_MUTEX_XATTR,
+	I_MUTEX_NONDIR2,
+	I_MUTEX_PARENT2,
+};
+
+void lock_two_nondirectories(struct inode *, struct inode*);
+void unlock_two_nondirectories(struct inode *, struct inode*);
+
+/*
+ * NOTE: in a 32bit arch with a preemptable kernel and
+ * an UP compile the i_size_read/write must be atomic
+ * with respect to the local cpu (unlike with preempt disabled),
+ * but they don't need to be atomic with respect to other cpus like in
+ * true SMP (so they need either to either locally disable irq around
+ * the read or for example on x86 they can be still implemented as a
+ * cmpxchg8b without the need of the lock prefix). For SMP compiles
+ * and 64bit archs it makes no difference if preempt is enabled or not.
+ */
+static inline loff_t i_size_read(const struct inode *inode)
+{
+#if BITS_PER_LONG==32 && defined(CONFIG_SMP)
+	loff_t i_size;
+	unsigned int seq;
+
+	do {
+		seq = read_seqcount_begin(&inode->i_size_seqcount);
+		i_size = inode->i_size;
+	} while (read_seqcount_retry(&inode->i_size_seqcount, seq));
+	return i_size;
+#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT)
+	loff_t i_size;
+
+	preempt_disable();
+	i_size = inode->i_size;
+	preempt_enable();
+	return i_size;
+#else
+	return inode->i_size;
+#endif
+}
+
+/*
+ * NOTE: unlike i_size_read(), i_size_write() does need locking around it
+ * (normally i_mutex), otherwise on 32bit/SMP an update of i_size_seqcount
+ * can be lost, resulting in subsequent i_size_read() calls spinning forever.
+ */
+static inline void i_size_write(struct inode *inode, loff_t i_size)
+{
+#if BITS_PER_LONG==32 && defined(CONFIG_SMP)
+	preempt_disable();
+	write_seqcount_begin(&inode->i_size_seqcount);
+	inode->i_size = i_size;
+	write_seqcount_end(&inode->i_size_seqcount);
+	preempt_enable();
+#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT)
+	preempt_disable();
+	inode->i_size = i_size;
+	preempt_enable();
+#else
+	inode->i_size = i_size;
+#endif
+}
+
+/* Helper functions so that in most cases filesystems will
+ * not need to deal directly with kuid_t and kgid_t and can
+ * instead deal with the raw numeric values that are stored
+ * in the filesystem.
+ */
+static inline uid_t i_uid_read(const struct inode *inode)
+{
+	return from_kuid(&init_user_ns, inode->i_uid);
+}
+
+static inline gid_t i_gid_read(const struct inode *inode)
+{
+	return from_kgid(&init_user_ns, inode->i_gid);
+}
+
+static inline void i_uid_write(struct inode *inode, uid_t uid)
+{
+	inode->i_uid = make_kuid(&init_user_ns, uid);
+}
+
+static inline void i_gid_write(struct inode *inode, gid_t gid)
+{
+	inode->i_gid = make_kgid(&init_user_ns, gid);
+}
+
+static inline unsigned iminor(const struct inode *inode)
+{
+	return MINOR(inode->i_rdev);
+}
+
+static inline unsigned imajor(const struct inode *inode)
+{
+	return MAJOR(inode->i_rdev);
+}
+
+extern struct block_device *I_BDEV(struct inode *inode);
+
+struct fown_struct {
+	rwlock_t lock;          /* protects pid, uid, euid fields */
+	struct pid *pid;	/* pid or -pgrp where SIGIO should be sent */
+	enum pid_type pid_type;	/* Kind of process group SIGIO should be sent to */
+	kuid_t uid, euid;	/* uid/euid of process setting the owner */
+	int signum;		/* posix.1b rt signal to be delivered on IO */
+};
+
+/*
+ * Track a single file's readahead state
+ */
+struct file_ra_state {
+	pgoff_t start;			/* where readahead started */
+	unsigned int size;		/* # of readahead pages */
+	unsigned int async_size;	/* do asynchronous readahead when
+					   there are only # of pages ahead */
+
+	unsigned int ra_pages;		/* Maximum readahead window */
+	unsigned int mmap_miss;		/* Cache miss stat for mmap accesses */
+	loff_t prev_pos;		/* Cache last read() position */
+};
+
+/*
+ * Check if @index falls in the readahead windows.
+ */
+static inline int ra_has_index(struct file_ra_state *ra, pgoff_t index)
+{
+	return (index >= ra->start &&
+		index <  ra->start + ra->size);
+}
+
+struct file {
+	union {
+		struct llist_node	fu_llist;
+		struct rcu_head 	fu_rcuhead;
+	} f_u;
+	struct path		f_path;
+	struct inode		*f_inode;	/* cached value */
+	const struct file_operations	*f_op;
+
+	/*
+	 * Protects f_ep_links, f_flags.
+	 * Must not be taken from IRQ context.
+	 */
+	spinlock_t		f_lock;
+	atomic_long_t		f_count;
+	unsigned int 		f_flags;
+	fmode_t			f_mode;
+	struct mutex		f_pos_lock;
+	loff_t			f_pos;
+	struct fown_struct	f_owner;
+	const struct cred	*f_cred;
+	struct file_ra_state	f_ra;
+
+	u64			f_version;
+#ifdef CONFIG_SECURITY
+	void			*f_security;
+#endif
+	/* needed for tty driver, and maybe others */
+	void			*private_data;
+
+#ifdef CONFIG_EPOLL
+	/* Used by fs/eventpoll.c to link all the hooks to this file */
+	struct list_head	f_ep_links;
+	struct list_head	f_tfile_llink;
+#endif /* #ifdef CONFIG_EPOLL */
+	struct address_space	*f_mapping;
+} __attribute__((aligned(4)));	/* lest something weird decides that 2 is OK */
+
+struct file_handle {
+	__u32 handle_bytes;
+	int handle_type;
+	/* file identifier */
+	unsigned char f_handle[0];
+};
+
+static inline struct file *get_file(struct file *f)
+{
+	atomic_long_inc(&f->f_count);
+	return f;
+}
+#define fput_atomic(x)	atomic_long_add_unless(&(x)->f_count, -1, 1)
+#define file_count(x)	atomic_long_read(&(x)->f_count)
+
+#define	MAX_NON_LFS	((1UL<<31) - 1)
+
+/* Page cache limit. The filesystems should put that into their s_maxbytes 
+   limits, otherwise bad things can happen in VM. */ 
+#if BITS_PER_LONG==32
+#define MAX_LFS_FILESIZE	(((loff_t)PAGE_CACHE_SIZE << (BITS_PER_LONG-1))-1) 
+#elif BITS_PER_LONG==64
+#define MAX_LFS_FILESIZE 	((loff_t)0x7fffffffffffffffLL)
+#endif
+
+#define FL_POSIX	1
+#define FL_FLOCK	2
+#define FL_DELEG	4	/* NFSv4 delegation */
+#define FL_ACCESS	8	/* not trying to lock, just looking */
+#define FL_EXISTS	16	/* when unlocking, test for existence */
+#define FL_LEASE	32	/* lease held on this file */
+#define FL_CLOSE	64	/* unlock on close */
+#define FL_SLEEP	128	/* A blocking lock */
+#define FL_DOWNGRADE_PENDING	256 /* Lease is being downgraded */
+#define FL_UNLOCK_PENDING	512 /* Lease is being broken */
+#define FL_OFDLCK	1024	/* lock is "owned" by struct file */
+#define FL_LAYOUT	2048	/* outstanding pNFS layout */
+
+/*
+ * Special return value from posix_lock_file() and vfs_lock_file() for
+ * asynchronous locking.
+ */
+#define FILE_LOCK_DEFERRED 1
+
+/* legacy typedef, should eventually be removed */
+typedef void *fl_owner_t;
+
+struct file_lock;
+
+struct file_lock_operations {
+	void (*fl_copy_lock)(struct file_lock *, struct file_lock *);
+	void (*fl_release_private)(struct file_lock *);
+};
+
+struct lock_manager_operations {
+	int (*lm_compare_owner)(struct file_lock *, struct file_lock *);
+	unsigned long (*lm_owner_key)(struct file_lock *);
+	void (*lm_get_owner)(struct file_lock *, struct file_lock *);
+	void (*lm_put_owner)(struct file_lock *);
+	void (*lm_notify)(struct file_lock *);	/* unblock callback */
+	int (*lm_grant)(struct file_lock *, int);
+	bool (*lm_break)(struct file_lock *);
+	int (*lm_change)(struct file_lock *, int, struct list_head *);
+	void (*lm_setup)(struct file_lock *, void **);
+};
+
+struct lock_manager {
+	struct list_head list;
+};
+
+struct net;
+void locks_start_grace(struct net *, struct lock_manager *);
+void locks_end_grace(struct lock_manager *);
+int locks_in_grace(struct net *);
+
+/* that will die - we need it for nfs_lock_info */
+#include <linux/nfs_fs_i.h>
+
+/*
+ * struct file_lock represents a generic "file lock". It's used to represent
+ * POSIX byte range locks, BSD (flock) locks, and leases. It's important to
+ * note that the same struct is used to represent both a request for a lock and
+ * the lock itself, but the same object is never used for both.
+ *
+ * FIXME: should we create a separate "struct lock_request" to help distinguish
+ * these two uses?
+ *
+ * The varous i_flctx lists are ordered by:
+ *
+ * 1) lock owner
+ * 2) lock range start
+ * 3) lock range end
+ *
+ * Obviously, the last two criteria only matter for POSIX locks.
+ */
+struct file_lock {
+	struct file_lock *fl_next;	/* singly linked list for this inode  */
+	struct list_head fl_list;	/* link into file_lock_context */
+	struct hlist_node fl_link;	/* node in global lists */
+	struct list_head fl_block;	/* circular list of blocked processes */
+	fl_owner_t fl_owner;
+	unsigned int fl_flags;
+	unsigned char fl_type;
+	unsigned int fl_pid;
+	int fl_link_cpu;		/* what cpu's list is this on? */
+	struct pid *fl_nspid;
+	wait_queue_head_t fl_wait;
+	struct file *fl_file;
+	loff_t fl_start;
+	loff_t fl_end;
+
+	struct fasync_struct *	fl_fasync; /* for lease break notifications */
+	/* for lease breaks: */
+	unsigned long fl_break_time;
+	unsigned long fl_downgrade_time;
+
+	const struct file_lock_operations *fl_ops;	/* Callbacks for filesystems */
+	const struct lock_manager_operations *fl_lmops;	/* Callbacks for lockmanagers */
+	union {
+		struct nfs_lock_info	nfs_fl;
+		struct nfs4_lock_info	nfs4_fl;
+		struct {
+			struct list_head link;	/* link in AFS vnode's pending_locks list */
+			int state;		/* state of grant or error if -ve */
+		} afs;
+	} fl_u;
+};
+
+struct file_lock_context {
+	spinlock_t		flc_lock;
+	struct list_head	flc_flock;
+	struct list_head	flc_posix;
+	struct list_head	flc_lease;
+};
+
+/* The following constant reflects the upper bound of the file/locking space */
+#ifndef OFFSET_MAX
+#define INT_LIMIT(x)	(~((x)1 << (sizeof(x)*8 - 1)))
+#define OFFSET_MAX	INT_LIMIT(loff_t)
+#define OFFT_OFFSET_MAX	INT_LIMIT(off_t)
+#endif
+
+#include <linux/fcntl.h>
+
+extern void send_sigio(struct fown_struct *fown, int fd, int band);
+
+#ifdef CONFIG_FILE_LOCKING
+extern int fcntl_getlk(struct file *, unsigned int, struct flock __user *);
+extern int fcntl_setlk(unsigned int, struct file *, unsigned int,
+			struct flock __user *);
+
+#if BITS_PER_LONG == 32
+extern int fcntl_getlk64(struct file *, unsigned int, struct flock64 __user *);
+extern int fcntl_setlk64(unsigned int, struct file *, unsigned int,
+			struct flock64 __user *);
+#endif
+
+extern int fcntl_setlease(unsigned int fd, struct file *filp, long arg);
+extern int fcntl_getlease(struct file *filp);
+
+/* fs/locks.c */
+void locks_free_lock_context(struct file_lock_context *ctx);
+void locks_free_lock(struct file_lock *fl);
+extern void locks_init_lock(struct file_lock *);
+extern struct file_lock * locks_alloc_lock(void);
+extern void locks_copy_lock(struct file_lock *, struct file_lock *);
+extern void locks_copy_conflock(struct file_lock *, struct file_lock *);
+extern void locks_remove_posix(struct file *, fl_owner_t);
+extern void locks_remove_file(struct file *);
+extern void locks_release_private(struct file_lock *);
+extern void posix_test_lock(struct file *, struct file_lock *);
+extern int posix_lock_file(struct file *, struct file_lock *, struct file_lock *);
+extern int posix_lock_file_wait(struct file *, struct file_lock *);
+extern int posix_unblock_lock(struct file_lock *);
+extern int vfs_test_lock(struct file *, struct file_lock *);
+extern int vfs_lock_file(struct file *, unsigned int, struct file_lock *, struct file_lock *);
+extern int vfs_cancel_lock(struct file *filp, struct file_lock *fl);
+extern int flock_lock_file_wait(struct file *filp, struct file_lock *fl);
+extern int __break_lease(struct inode *inode, unsigned int flags, unsigned int type);
+extern void lease_get_mtime(struct inode *, struct timespec *time);
+extern int generic_setlease(struct file *, long, struct file_lock **, void **priv);
+extern int vfs_setlease(struct file *, long, struct file_lock **, void **);
+extern int lease_modify(struct file_lock *, int, struct list_head *);
+#else /* !CONFIG_FILE_LOCKING */
+static inline int fcntl_getlk(struct file *file, unsigned int cmd,
+			      struct flock __user *user)
+{
+	return -EINVAL;
+}
+
+static inline int fcntl_setlk(unsigned int fd, struct file *file,
+			      unsigned int cmd, struct flock __user *user)
+{
+	return -EACCES;
+}
+
+#if BITS_PER_LONG == 32
+static inline int fcntl_getlk64(struct file *file, unsigned int cmd,
+				struct flock64 __user *user)
+{
+	return -EINVAL;
+}
+
+static inline int fcntl_setlk64(unsigned int fd, struct file *file,
+				unsigned int cmd, struct flock64 __user *user)
+{
+	return -EACCES;
+}
+#endif
+static inline int fcntl_setlease(unsigned int fd, struct file *filp, long arg)
+{
+	return -EINVAL;
+}
+
+static inline int fcntl_getlease(struct file *filp)
+{
+	return F_UNLCK;
+}
+
+static inline void
+locks_free_lock_context(struct file_lock_context *ctx)
+{
+}
+
+static inline void locks_init_lock(struct file_lock *fl)
+{
+	return;
+}
+
+static inline void locks_copy_conflock(struct file_lock *new, struct file_lock *fl)
+{
+	return;
+}
+
+static inline void locks_copy_lock(struct file_lock *new, struct file_lock *fl)
+{
+	return;
+}
+
+static inline void locks_remove_posix(struct file *filp, fl_owner_t owner)
+{
+	return;
+}
+
+static inline void locks_remove_file(struct file *filp)
+{
+	return;
+}
+
+static inline void posix_test_lock(struct file *filp, struct file_lock *fl)
+{
+	return;
+}
+
+static inline int posix_lock_file(struct file *filp, struct file_lock *fl,
+				  struct file_lock *conflock)
+{
+	return -ENOLCK;
+}
+
+static inline int posix_lock_file_wait(struct file *filp, struct file_lock *fl)
+{
+	return -ENOLCK;
+}
+
+static inline int posix_unblock_lock(struct file_lock *waiter)
+{
+	return -ENOENT;
+}
+
+static inline int vfs_test_lock(struct file *filp, struct file_lock *fl)
+{
+	return 0;
+}
+
+static inline int vfs_lock_file(struct file *filp, unsigned int cmd,
+				struct file_lock *fl, struct file_lock *conf)
+{
+	return -ENOLCK;
+}
+
+static inline int vfs_cancel_lock(struct file *filp, struct file_lock *fl)
+{
+	return 0;
+}
+
+static inline int flock_lock_file_wait(struct file *filp,
+				       struct file_lock *request)
+{
+	return -ENOLCK;
+}
+
+static inline int __break_lease(struct inode *inode, unsigned int mode, unsigned int type)
+{
+	return 0;
+}
+
+static inline void lease_get_mtime(struct inode *inode, struct timespec *time)
+{
+	return;
+}
+
+static inline int generic_setlease(struct file *filp, long arg,
+				    struct file_lock **flp, void **priv)
+{
+	return -EINVAL;
+}
+
+static inline int vfs_setlease(struct file *filp, long arg,
+			       struct file_lock **lease, void **priv)
+{
+	return -EINVAL;
+}
+
+static inline int lease_modify(struct file_lock *fl, int arg,
+			       struct list_head *dispose)
+{
+	return -EINVAL;
+}
+#endif /* !CONFIG_FILE_LOCKING */
+
+
+struct fasync_struct {
+	spinlock_t		fa_lock;
+	int			magic;
+	int			fa_fd;
+	struct fasync_struct	*fa_next; /* singly linked list */
+	struct file		*fa_file;
+	struct rcu_head		fa_rcu;
+};
+
+#define FASYNC_MAGIC 0x4601
+
+/* SMP safe fasync helpers: */
+extern int fasync_helper(int, struct file *, int, struct fasync_struct **);
+extern struct fasync_struct *fasync_insert_entry(int, struct file *, struct fasync_struct **, struct fasync_struct *);
+extern int fasync_remove_entry(struct file *, struct fasync_struct **);
+extern struct fasync_struct *fasync_alloc(void);
+extern void fasync_free(struct fasync_struct *);
+
+/* can be called from interrupts */
+extern void kill_fasync(struct fasync_struct **, int, int);
+
+extern void __f_setown(struct file *filp, struct pid *, enum pid_type, int force);
+extern void f_setown(struct file *filp, unsigned long arg, int force);
+extern void f_delown(struct file *filp);
+extern pid_t f_getown(struct file *filp);
+extern int send_sigurg(struct fown_struct *fown);
+
+struct mm_struct;
+
+/*
+ *	Umount options
+ */
+
+#define MNT_FORCE	0x00000001	/* Attempt to forcibily umount */
+#define MNT_DETACH	0x00000002	/* Just detach from the tree */
+#define MNT_EXPIRE	0x00000004	/* Mark for expiry */
+#define UMOUNT_NOFOLLOW	0x00000008	/* Don't follow symlink on umount */
+#define UMOUNT_UNUSED	0x80000000	/* Flag guaranteed to be unused */
+
+
+/* Possible states of 'frozen' field */
+enum {
+	SB_UNFROZEN = 0,		/* FS is unfrozen */
+	SB_FREEZE_WRITE	= 1,		/* Writes, dir ops, ioctls frozen */
+	SB_FREEZE_PAGEFAULT = 2,	/* Page faults stopped as well */
+	SB_FREEZE_FS = 3,		/* For internal FS use (e.g. to stop
+					 * internal threads if needed) */
+	SB_FREEZE_COMPLETE = 4,		/* ->freeze_fs finished successfully */
+};
+
+#define SB_FREEZE_LEVELS (SB_FREEZE_COMPLETE - 1)
+
+struct sb_writers {
+	/* Counters for counting writers at each level */
+	struct percpu_counter	counter[SB_FREEZE_LEVELS];
+	wait_queue_head_t	wait;		/* queue for waiting for
+						   writers / faults to finish */
+	int			frozen;		/* Is sb frozen? */
+	wait_queue_head_t	wait_unfrozen;	/* queue for waiting for
+						   sb to be thawed */
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+	struct lockdep_map	lock_map[SB_FREEZE_LEVELS];
+#endif
+};
+
+struct super_block {
+	struct list_head	s_list;		/* Keep this first */
+	dev_t			s_dev;		/* search index; _not_ kdev_t */
+	unsigned char		s_blocksize_bits;
+	unsigned long		s_blocksize;
+	loff_t			s_maxbytes;	/* Max file size */
+	struct file_system_type	*s_type;
+	const struct super_operations	*s_op;
+	const struct dquot_operations	*dq_op;
+	const struct quotactl_ops	*s_qcop;
+	const struct export_operations *s_export_op;
+	unsigned long		s_flags;
+	unsigned long		s_magic;
+	struct dentry		*s_root;
+	struct rw_semaphore	s_umount;
+	int			s_count;
+	atomic_t		s_active;
+#ifdef CONFIG_SECURITY
+	void                    *s_security;
+#endif
+	const struct xattr_handler **s_xattr;
+
+	struct list_head	s_inodes;	/* all inodes */
+	struct hlist_bl_head	s_anon;		/* anonymous dentries for (nfs) exporting */
+	struct list_head	s_mounts;	/* list of mounts; _not_ for fs use */
+	struct block_device	*s_bdev;
+	struct backing_dev_info *s_bdi;
+	struct mtd_info		*s_mtd;
+	struct hlist_node	s_instances;
+	unsigned int		s_quota_types;	/* Bitmask of supported quota types */
+	struct quota_info	s_dquot;	/* Diskquota specific options */
+
+	struct sb_writers	s_writers;
+
+	char s_id[32];				/* Informational name */
+	u8 s_uuid[16];				/* UUID */
+
+	void 			*s_fs_info;	/* Filesystem private info */
+	unsigned int		s_max_links;
+	fmode_t			s_mode;
+
+	/* Granularity of c/m/atime in ns.
+	   Cannot be worse than a second */
+	u32		   s_time_gran;
+
+	/*
+	 * The next field is for VFS *only*. No filesystems have any business
+	 * even looking at it. You had been warned.
+	 */
+	struct mutex s_vfs_rename_mutex;	/* Kludge */
+
+	/*
+	 * Filesystem subtype.  If non-empty the filesystem type field
+	 * in /proc/mounts will be "type.subtype"
+	 */
+	char *s_subtype;
+
+	/*
+	 * Saved mount options for lazy filesystems using
+	 * generic_show_options()
+	 */
+	char __rcu *s_options;
+	const struct dentry_operations *s_d_op; /* default d_op for dentries */
+
+	/*
+	 * Saved pool identifier for cleancache (-1 means none)
+	 */
+	int cleancache_poolid;
+
+	struct shrinker s_shrink;	/* per-sb shrinker handle */
+
+	/* Number of inodes with nlink == 0 but still referenced */
+	atomic_long_t s_remove_count;
+
+	/* Being remounted read-only */
+	int s_readonly_remount;
+
+	/* AIO completions deferred from interrupt context */
+	struct workqueue_struct *s_dio_done_wq;
+	struct hlist_head s_pins;
+
+	/*
+	 * Keep the lru lists last in the structure so they always sit on their
+	 * own individual cachelines.
+	 */
+	struct list_lru		s_dentry_lru ____cacheline_aligned_in_smp;
+	struct list_lru		s_inode_lru ____cacheline_aligned_in_smp;
+	struct rcu_head		rcu;
+
+	/*
+	 * Indicates how deep in a filesystem stack this SB is
+	 */
+	int s_stack_depth;
+};
+
+extern struct timespec current_fs_time(struct super_block *sb);
+
+/*
+ * Snapshotting support.
+ */
+
+void __sb_end_write(struct super_block *sb, int level);
+int __sb_start_write(struct super_block *sb, int level, bool wait);
+
+/**
+ * sb_end_write - drop write access to a superblock
+ * @sb: the super we wrote to
+ *
+ * Decrement number of writers to the filesystem. Wake up possible waiters
+ * wanting to freeze the filesystem.
+ */
+static inline void sb_end_write(struct super_block *sb)
+{
+	__sb_end_write(sb, SB_FREEZE_WRITE);
+}
+
+/**
+ * sb_end_pagefault - drop write access to a superblock from a page fault
+ * @sb: the super we wrote to
+ *
+ * Decrement number of processes handling write page fault to the filesystem.
+ * Wake up possible waiters wanting to freeze the filesystem.
+ */
+static inline void sb_end_pagefault(struct super_block *sb)
+{
+	__sb_end_write(sb, SB_FREEZE_PAGEFAULT);
+}
+
+/**
+ * sb_end_intwrite - drop write access to a superblock for internal fs purposes
+ * @sb: the super we wrote to
+ *
+ * Decrement fs-internal number of writers to the filesystem.  Wake up possible
+ * waiters wanting to freeze the filesystem.
+ */
+static inline void sb_end_intwrite(struct super_block *sb)
+{
+	__sb_end_write(sb, SB_FREEZE_FS);
+}
+
+/**
+ * sb_start_write - get write access to a superblock
+ * @sb: the super we write to
+ *
+ * When a process wants to write data or metadata to a file system (i.e. dirty
+ * a page or an inode), it should embed the operation in a sb_start_write() -
+ * sb_end_write() pair to get exclusion against file system freezing. This
+ * function increments number of writers preventing freezing. If the file
+ * system is already frozen, the function waits until the file system is
+ * thawed.
+ *
+ * Since freeze protection behaves as a lock, users have to preserve
+ * ordering of freeze protection and other filesystem locks. Generally,
+ * freeze protection should be the outermost lock. In particular, we have:
+ *
+ * sb_start_write
+ *   -> i_mutex			(write path, truncate, directory ops, ...)
+ *   -> s_umount		(freeze_super, thaw_super)
+ */
+static inline void sb_start_write(struct super_block *sb)
+{
+	__sb_start_write(sb, SB_FREEZE_WRITE, true);
+}
+
+static inline int sb_start_write_trylock(struct super_block *sb)
+{
+	return __sb_start_write(sb, SB_FREEZE_WRITE, false);
+}
+
+/**
+ * sb_start_pagefault - get write access to a superblock from a page fault
+ * @sb: the super we write to
+ *
+ * When a process starts handling write page fault, it should embed the
+ * operation into sb_start_pagefault() - sb_end_pagefault() pair to get
+ * exclusion against file system freezing. This is needed since the page fault
+ * is going to dirty a page. This function increments number of running page
+ * faults preventing freezing. If the file system is already frozen, the
+ * function waits until the file system is thawed.
+ *
+ * Since page fault freeze protection behaves as a lock, users have to preserve
+ * ordering of freeze protection and other filesystem locks. It is advised to
+ * put sb_start_pagefault() close to mmap_sem in lock ordering. Page fault
+ * handling code implies lock dependency:
+ *
+ * mmap_sem
+ *   -> sb_start_pagefault
+ */
+static inline void sb_start_pagefault(struct super_block *sb)
+{
+	__sb_start_write(sb, SB_FREEZE_PAGEFAULT, true);
+}
+
+/*
+ * sb_start_intwrite - get write access to a superblock for internal fs purposes
+ * @sb: the super we write to
+ *
+ * This is the third level of protection against filesystem freezing. It is
+ * free for use by a filesystem. The only requirement is that it must rank
+ * below sb_start_pagefault.
+ *
+ * For example filesystem can call sb_start_intwrite() when starting a
+ * transaction which somewhat eases handling of freezing for internal sources
+ * of filesystem changes (internal fs threads, discarding preallocation on file
+ * close, etc.).
+ */
+static inline void sb_start_intwrite(struct super_block *sb)
+{
+	__sb_start_write(sb, SB_FREEZE_FS, true);
+}
+
+
+extern bool inode_owner_or_capable(const struct inode *inode);
+
+/*
+ * VFS helper functions..
+ */
+extern int vfs_create(struct inode *, struct dentry *, umode_t, bool);
+extern int vfs_mkdir(struct inode *, struct dentry *, umode_t);
+extern int vfs_mknod(struct inode *, struct dentry *, umode_t, dev_t);
+extern int vfs_symlink(struct inode *, struct dentry *, const char *);
+extern int vfs_link(struct dentry *, struct inode *, struct dentry *, struct inode **);
+extern int vfs_rmdir(struct inode *, struct dentry *);
+extern int vfs_unlink(struct inode *, struct dentry *, struct inode **);
+extern int vfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *, struct inode **, unsigned int);
+extern int vfs_whiteout(struct inode *, struct dentry *);
+
+/*
+ * VFS dentry helper functions.
+ */
+extern void dentry_unhash(struct dentry *dentry);
+
+/*
+ * VFS file helper functions.
+ */
+extern void inode_init_owner(struct inode *inode, const struct inode *dir,
+			umode_t mode);
+/*
+ * VFS FS_IOC_FIEMAP helper definitions.
+ */
+struct fiemap_extent_info {
+	unsigned int fi_flags;		/* Flags as passed from user */
+	unsigned int fi_extents_mapped;	/* Number of mapped extents */
+	unsigned int fi_extents_max;	/* Size of fiemap_extent array */
+	struct fiemap_extent __user *fi_extents_start; /* Start of
+							fiemap_extent array */
+};
+int fiemap_fill_next_extent(struct fiemap_extent_info *info, u64 logical,
+			    u64 phys, u64 len, u32 flags);
+int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags);
+
+/*
+ * File types
+ *
+ * NOTE! These match bits 12..15 of stat.st_mode
+ * (ie "(i_mode >> 12) & 15").
+ */
+#define DT_UNKNOWN	0
+#define DT_FIFO		1
+#define DT_CHR		2
+#define DT_DIR		4
+#define DT_BLK		6
+#define DT_REG		8
+#define DT_LNK		10
+#define DT_SOCK		12
+#define DT_WHT		14
+
+/*
+ * This is the "filldir" function type, used by readdir() to let
+ * the kernel specify what kind of dirent layout it wants to have.
+ * This allows the kernel to read directories into kernel space or
+ * to have different dirent layouts depending on the binary type.
+ */
+struct dir_context;
+typedef int (*filldir_t)(struct dir_context *, const char *, int, loff_t, u64,
+			 unsigned);
+
+struct dir_context {
+	const filldir_t actor;
+	loff_t pos;
+};
+
+struct block_device_operations;
+
+/* These macros are for out of kernel modules to test that
+ * the kernel supports the unlocked_ioctl and compat_ioctl
+ * fields in struct file_operations. */
+#define HAVE_COMPAT_IOCTL 1
+#define HAVE_UNLOCKED_IOCTL 1
+
+/*
+ * These flags let !MMU mmap() govern direct device mapping vs immediate
+ * copying more easily for MAP_PRIVATE, especially for ROM filesystems.
+ *
+ * NOMMU_MAP_COPY:	Copy can be mapped (MAP_PRIVATE)
+ * NOMMU_MAP_DIRECT:	Can be mapped directly (MAP_SHARED)
+ * NOMMU_MAP_READ:	Can be mapped for reading
+ * NOMMU_MAP_WRITE:	Can be mapped for writing
+ * NOMMU_MAP_EXEC:	Can be mapped for execution
+ */
+#define NOMMU_MAP_COPY		0x00000001
+#define NOMMU_MAP_DIRECT	0x00000008
+#define NOMMU_MAP_READ		VM_MAYREAD
+#define NOMMU_MAP_WRITE		VM_MAYWRITE
+#define NOMMU_MAP_EXEC		VM_MAYEXEC
+
+#define NOMMU_VMFLAGS \
+	(NOMMU_MAP_READ | NOMMU_MAP_WRITE | NOMMU_MAP_EXEC)
+
+
+struct iov_iter;
+
+struct file_operations {
+	struct module *owner;
+	loff_t (*llseek) (struct file *, loff_t, int);
+	ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
+	ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
+	ssize_t (*aio_read) (struct kiocb *, const struct iovec *, unsigned long, loff_t);
+	ssize_t (*aio_write) (struct kiocb *, const struct iovec *, unsigned long, loff_t);
+	ssize_t (*read_iter) (struct kiocb *, struct iov_iter *);
+	ssize_t (*write_iter) (struct kiocb *, struct iov_iter *);
+	int (*iterate) (struct file *, struct dir_context *);
+	unsigned int (*poll) (struct file *, struct poll_table_struct *);
+	long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
+	long (*compat_ioctl) (struct file *, unsigned int, unsigned long);
+	int (*mmap) (struct file *, struct vm_area_struct *);
+	int (*mremap)(struct file *, struct vm_area_struct *);
+	int (*open) (struct inode *, struct file *);
+	int (*flush) (struct file *, fl_owner_t id);
+	int (*release) (struct inode *, struct file *);
+	int (*fsync) (struct file *, loff_t, loff_t, int datasync);
+	int (*aio_fsync) (struct kiocb *, int datasync);
+	int (*fasync) (int, struct file *, int);
+	int (*lock) (struct file *, int, struct file_lock *);
+	ssize_t (*sendpage) (struct file *, struct page *, int, size_t, loff_t *, int);
+	unsigned long (*get_unmapped_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
+	int (*check_flags)(int);
+	int (*flock) (struct file *, int, struct file_lock *);
+	ssize_t (*splice_write)(struct pipe_inode_info *, struct file *, loff_t *, size_t, unsigned int);
+	ssize_t (*splice_read)(struct file *, loff_t *, struct pipe_inode_info *, size_t, unsigned int);
+	int (*setlease)(struct file *, long, struct file_lock **, void **);
+	long (*fallocate)(struct file *file, int mode, loff_t offset,
+			  loff_t len);
+	void (*show_fdinfo)(struct seq_file *m, struct file *f);
+#ifndef CONFIG_MMU
+	unsigned (*mmap_capabilities)(struct file *);
+#endif
+};
+
+struct inode_operations {
+	struct dentry * (*lookup) (struct inode *,struct dentry *, unsigned int);
+	void * (*follow_link) (struct dentry *, struct nameidata *);
+	int (*permission) (struct inode *, int);
+	struct posix_acl * (*get_acl)(struct inode *, int);
+
+	int (*readlink) (struct dentry *, char __user *,int);
+	void (*put_link) (struct dentry *, struct nameidata *, void *);
+
+	int (*create) (struct inode *,struct dentry *, umode_t, bool);
+	int (*link) (struct dentry *,struct inode *,struct dentry *);
+	int (*unlink) (struct inode *,struct dentry *);
+	int (*symlink) (struct inode *,struct dentry *,const char *);
+	int (*mkdir) (struct inode *,struct dentry *,umode_t);
+	int (*rmdir) (struct inode *,struct dentry *);
+	int (*mknod) (struct inode *,struct dentry *,umode_t,dev_t);
+	int (*rename) (struct inode *, struct dentry *,
+			struct inode *, struct dentry *);
+	int (*rename2) (struct inode *, struct dentry *,
+			struct inode *, struct dentry *, unsigned int);
+	int (*setattr) (struct dentry *, struct iattr *);
+	int (*getattr) (struct vfsmount *mnt, struct dentry *, struct kstat *);
+	int (*setxattr) (struct dentry *, const char *,const void *,size_t,int);
+	ssize_t (*getxattr) (struct dentry *, const char *, void *, size_t);
+	ssize_t (*listxattr) (struct dentry *, char *, size_t);
+	int (*removexattr) (struct dentry *, const char *);
+	int (*fiemap)(struct inode *, struct fiemap_extent_info *, u64 start,
+		      u64 len);
+	int (*update_time)(struct inode *, struct timespec *, int);
+	int (*atomic_open)(struct inode *, struct dentry *,
+			   struct file *, unsigned open_flag,
+			   umode_t create_mode, int *opened);
+	int (*tmpfile) (struct inode *, struct dentry *, umode_t);
+	int (*set_acl)(struct inode *, struct posix_acl *, int);
+
+	/* WARNING: probably going away soon, do not use! */
+	int (*dentry_open)(struct dentry *, struct file *, const struct cred *);
+} ____cacheline_aligned;
+
+ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector,
+			      unsigned long nr_segs, unsigned long fast_segs,
+			      struct iovec *fast_pointer,
+			      struct iovec **ret_pointer);
+
+extern ssize_t __vfs_read(struct file *, char __user *, size_t, loff_t *);
+extern ssize_t vfs_read(struct file *, char __user *, size_t, loff_t *);
+extern ssize_t vfs_write(struct file *, const char __user *, size_t, loff_t *);
+extern ssize_t vfs_readv(struct file *, const struct iovec __user *,
+		unsigned long, loff_t *);
+extern ssize_t vfs_writev(struct file *, const struct iovec __user *,
+		unsigned long, loff_t *);
+
+struct super_operations {
+   	struct inode *(*alloc_inode)(struct super_block *sb);
+	void (*destroy_inode)(struct inode *);
+
+   	void (*dirty_inode) (struct inode *, int flags);
+	int (*write_inode) (struct inode *, struct writeback_control *wbc);
+	int (*drop_inode) (struct inode *);
+	void (*evict_inode) (struct inode *);
+	void (*put_super) (struct super_block *);
+	int (*sync_fs)(struct super_block *sb, int wait);
+	int (*freeze_super) (struct super_block *);
+	int (*freeze_fs) (struct super_block *);
+	int (*thaw_super) (struct super_block *);
+	int (*unfreeze_fs) (struct super_block *);
+	int (*statfs) (struct dentry *, struct kstatfs *);
+	int (*remount_fs) (struct super_block *, int *, char *);
+	void (*umount_begin) (struct super_block *);
+
+	int (*show_options)(struct seq_file *, struct dentry *);
+	int (*show_devname)(struct seq_file *, struct dentry *);
+	int (*show_path)(struct seq_file *, struct dentry *);
+	int (*show_stats)(struct seq_file *, struct dentry *);
+#ifdef CONFIG_QUOTA
+	ssize_t (*quota_read)(struct super_block *, int, char *, size_t, loff_t);
+	ssize_t (*quota_write)(struct super_block *, int, const char *, size_t, loff_t);
+	struct dquot **(*get_dquots)(struct inode *);
+#endif
+	int (*bdev_try_to_free_page)(struct super_block*, struct page*, gfp_t);
+	long (*nr_cached_objects)(struct super_block *,
+				  struct shrink_control *);
+	long (*free_cached_objects)(struct super_block *,
+				    struct shrink_control *);
+};
+
+/*
+ * Inode flags - they have no relation to superblock flags now
+ */
+#define S_SYNC		1	/* Writes are synced at once */
+#define S_NOATIME	2	/* Do not update access times */
+#define S_APPEND	4	/* Append-only file */
+#define S_IMMUTABLE	8	/* Immutable file */
+#define S_DEAD		16	/* removed, but still open directory */
+#define S_NOQUOTA	32	/* Inode is not counted to quota */
+#define S_DIRSYNC	64	/* Directory modifications are synchronous */
+#define S_NOCMTIME	128	/* Do not update file c/mtime */
+#define S_SWAPFILE	256	/* Do not truncate: swapon got its bmaps */
+#define S_PRIVATE	512	/* Inode is fs-internal */
+#define S_IMA		1024	/* Inode has an associated IMA struct */
+#define S_AUTOMOUNT	2048	/* Automount/referral quasi-directory */
+#define S_NOSEC		4096	/* no suid or xattr security attributes */
+#ifdef CONFIG_FS_DAX
+#define S_DAX		8192	/* Direct Access, avoiding the page cache */
+#else
+#define S_DAX		0	/* Make all the DAX code disappear */
+#endif
+
+/*
+ * Note that nosuid etc flags are inode-specific: setting some file-system
+ * flags just means all the inodes inherit those flags by default. It might be
+ * possible to override it selectively if you really wanted to with some
+ * ioctl() that is not currently implemented.
+ *
+ * Exception: MS_RDONLY is always applied to the entire file system.
+ *
+ * Unfortunately, it is possible to change a filesystems flags with it mounted
+ * with files in use.  This means that all of the inodes will not have their
+ * i_flags updated.  Hence, i_flags no longer inherit the superblock mount
+ * flags, so these have to be checked separately. -- rmk@arm.uk.linux.org
+ */
+#define __IS_FLG(inode, flg)	((inode)->i_sb->s_flags & (flg))
+
+#define IS_RDONLY(inode)	((inode)->i_sb->s_flags & MS_RDONLY)
+#define IS_SYNC(inode)		(__IS_FLG(inode, MS_SYNCHRONOUS) || \
+					((inode)->i_flags & S_SYNC))
+#define IS_DIRSYNC(inode)	(__IS_FLG(inode, MS_SYNCHRONOUS|MS_DIRSYNC) || \
+					((inode)->i_flags & (S_SYNC|S_DIRSYNC)))
+#define IS_MANDLOCK(inode)	__IS_FLG(inode, MS_MANDLOCK)
+#define IS_NOATIME(inode)	__IS_FLG(inode, MS_RDONLY|MS_NOATIME)
+#define IS_I_VERSION(inode)	__IS_FLG(inode, MS_I_VERSION)
+
+#define IS_NOQUOTA(inode)	((inode)->i_flags & S_NOQUOTA)
+#define IS_APPEND(inode)	((inode)->i_flags & S_APPEND)
+#define IS_IMMUTABLE(inode)	((inode)->i_flags & S_IMMUTABLE)
+#define IS_POSIXACL(inode)	__IS_FLG(inode, MS_POSIXACL)
+
+#define IS_DEADDIR(inode)	((inode)->i_flags & S_DEAD)
+#define IS_NOCMTIME(inode)	((inode)->i_flags & S_NOCMTIME)
+#define IS_SWAPFILE(inode)	((inode)->i_flags & S_SWAPFILE)
+#define IS_PRIVATE(inode)	((inode)->i_flags & S_PRIVATE)
+#define IS_IMA(inode)		((inode)->i_flags & S_IMA)
+#define IS_AUTOMOUNT(inode)	((inode)->i_flags & S_AUTOMOUNT)
+#define IS_NOSEC(inode)		((inode)->i_flags & S_NOSEC)
+#define IS_DAX(inode)		((inode)->i_flags & S_DAX)
+
+#define IS_WHITEOUT(inode)	(S_ISCHR(inode->i_mode) && \
+				 (inode)->i_rdev == WHITEOUT_DEV)
+
+/*
+ * Inode state bits.  Protected by inode->i_lock
+ *
+ * Three bits determine the dirty state of the inode, I_DIRTY_SYNC,
+ * I_DIRTY_DATASYNC and I_DIRTY_PAGES.
+ *
+ * Four bits define the lifetime of an inode.  Initially, inodes are I_NEW,
+ * until that flag is cleared.  I_WILL_FREE, I_FREEING and I_CLEAR are set at
+ * various stages of removing an inode.
+ *
+ * Two bits are used for locking and completion notification, I_NEW and I_SYNC.
+ *
+ * I_DIRTY_SYNC		Inode is dirty, but doesn't have to be written on
+ *			fdatasync().  i_atime is the usual cause.
+ * I_DIRTY_DATASYNC	Data-related inode changes pending. We keep track of
+ *			these changes separately from I_DIRTY_SYNC so that we
+ *			don't have to write inode on fdatasync() when only
+ *			mtime has changed in it.
+ * I_DIRTY_PAGES	Inode has dirty pages.  Inode itself may be clean.
+ * I_NEW		Serves as both a mutex and completion notification.
+ *			New inodes set I_NEW.  If two processes both create
+ *			the same inode, one of them will release its inode and
+ *			wait for I_NEW to be released before returning.
+ *			Inodes in I_WILL_FREE, I_FREEING or I_CLEAR state can
+ *			also cause waiting on I_NEW, without I_NEW actually
+ *			being set.  find_inode() uses this to prevent returning
+ *			nearly-dead inodes.
+ * I_WILL_FREE		Must be set when calling write_inode_now() if i_count
+ *			is zero.  I_FREEING must be set when I_WILL_FREE is
+ *			cleared.
+ * I_FREEING		Set when inode is about to be freed but still has dirty
+ *			pages or buffers attached or the inode itself is still
+ *			dirty.
+ * I_CLEAR		Added by clear_inode().  In this state the inode is
+ *			clean and can be destroyed.  Inode keeps I_FREEING.
+ *
+ *			Inodes that are I_WILL_FREE, I_FREEING or I_CLEAR are
+ *			prohibited for many purposes.  iget() must wait for
+ *			the inode to be completely released, then create it
+ *			anew.  Other functions will just ignore such inodes,
+ *			if appropriate.  I_NEW is used for waiting.
+ *
+ * I_SYNC		Writeback of inode is running. The bit is set during
+ *			data writeback, and cleared with a wakeup on the bit
+ *			address once it is done. The bit is also used to pin
+ *			the inode in memory for flusher thread.
+ *
+ * I_REFERENCED		Marks the inode as recently references on the LRU list.
+ *
+ * I_DIO_WAKEUP		Never set.  Only used as a key for wait_on_bit().
+ *
+ * Q: What is the difference between I_WILL_FREE and I_FREEING?
+ */
+#define I_DIRTY_SYNC		(1 << 0)
+#define I_DIRTY_DATASYNC	(1 << 1)
+#define I_DIRTY_PAGES		(1 << 2)
+#define __I_NEW			3
+#define I_NEW			(1 << __I_NEW)
+#define I_WILL_FREE		(1 << 4)
+#define I_FREEING		(1 << 5)
+#define I_CLEAR			(1 << 6)
+#define __I_SYNC		7
+#define I_SYNC			(1 << __I_SYNC)
+#define I_REFERENCED		(1 << 8)
+#define __I_DIO_WAKEUP		9
+#define I_DIO_WAKEUP		(1 << I_DIO_WAKEUP)
+#define I_LINKABLE		(1 << 10)
+#define I_DIRTY_TIME		(1 << 11)
+#define __I_DIRTY_TIME_EXPIRED	12
+#define I_DIRTY_TIME_EXPIRED	(1 << __I_DIRTY_TIME_EXPIRED)
+
+#define I_DIRTY (I_DIRTY_SYNC | I_DIRTY_DATASYNC | I_DIRTY_PAGES)
+#define I_DIRTY_ALL (I_DIRTY | I_DIRTY_TIME)
+
+extern void __mark_inode_dirty(struct inode *, int);
+static inline void mark_inode_dirty(struct inode *inode)
+{
+	__mark_inode_dirty(inode, I_DIRTY);
+}
+
+static inline void mark_inode_dirty_sync(struct inode *inode)
+{
+	__mark_inode_dirty(inode, I_DIRTY_SYNC);
+}
+
+extern void inc_nlink(struct inode *inode);
+extern void drop_nlink(struct inode *inode);
+extern void clear_nlink(struct inode *inode);
+extern void set_nlink(struct inode *inode, unsigned int nlink);
+
+static inline void inode_inc_link_count(struct inode *inode)
+{
+	inc_nlink(inode);
+	mark_inode_dirty(inode);
+}
+
+static inline void inode_dec_link_count(struct inode *inode)
+{
+	drop_nlink(inode);
+	mark_inode_dirty(inode);
+}
+
+/**
+ * inode_inc_iversion - increments i_version
+ * @inode: inode that need to be updated
+ *
+ * Every time the inode is modified, the i_version field will be incremented.
+ * The filesystem has to be mounted with i_version flag
+ */
+
+static inline void inode_inc_iversion(struct inode *inode)
+{
+       spin_lock(&inode->i_lock);
+       inode->i_version++;
+       spin_unlock(&inode->i_lock);
+}
+
+enum file_time_flags {
+	S_ATIME = 1,
+	S_MTIME = 2,
+	S_CTIME = 4,
+	S_VERSION = 8,
+};
+
+extern void touch_atime(const struct path *);
+static inline void file_accessed(struct file *file)
+{
+	if (!(file->f_flags & O_NOATIME))
+		touch_atime(&file->f_path);
+}
+
+int sync_inode(struct inode *inode, struct writeback_control *wbc);
+int sync_inode_metadata(struct inode *inode, int wait);
+
+struct file_system_type {
+	const char *name;
+	int fs_flags;
+#define FS_REQUIRES_DEV		1 
+#define FS_BINARY_MOUNTDATA	2
+#define FS_HAS_SUBTYPE		4
+#define FS_USERNS_MOUNT		8	/* Can be mounted by userns root */
+#define FS_USERNS_DEV_MOUNT	16 /* A userns mount does not imply MNT_NODEV */
+#define FS_RENAME_DOES_D_MOVE	32768	/* FS will handle d_move() during rename() internally. */
+	struct dentry *(*mount) (struct file_system_type *, int,
+		       const char *, void *);
+	void (*kill_sb) (struct super_block *);
+	struct module *owner;
+	struct file_system_type * next;
+	struct hlist_head fs_supers;
+
+	struct lock_class_key s_lock_key;
+	struct lock_class_key s_umount_key;
+	struct lock_class_key s_vfs_rename_key;
+	struct lock_class_key s_writers_key[SB_FREEZE_LEVELS];
+
+	struct lock_class_key i_lock_key;
+	struct lock_class_key i_mutex_key;
+	struct lock_class_key i_mutex_dir_key;
+};
+
+#define MODULE_ALIAS_FS(NAME) MODULE_ALIAS("fs-" NAME)
+
+extern struct dentry *mount_ns(struct file_system_type *fs_type, int flags,
+	void *data, int (*fill_super)(struct super_block *, void *, int));
+extern struct dentry *mount_bdev(struct file_system_type *fs_type,
+	int flags, const char *dev_name, void *data,
+	int (*fill_super)(struct super_block *, void *, int));
+extern struct dentry *mount_single(struct file_system_type *fs_type,
+	int flags, void *data,
+	int (*fill_super)(struct super_block *, void *, int));
+extern struct dentry *mount_nodev(struct file_system_type *fs_type,
+	int flags, void *data,
+	int (*fill_super)(struct super_block *, void *, int));
+extern struct dentry *mount_subtree(struct vfsmount *mnt, const char *path);
+void generic_shutdown_super(struct super_block *sb);
+void kill_block_super(struct super_block *sb);
+void kill_anon_super(struct super_block *sb);
+void kill_litter_super(struct super_block *sb);
+void deactivate_super(struct super_block *sb);
+void deactivate_locked_super(struct super_block *sb);
+int set_anon_super(struct super_block *s, void *data);
+int get_anon_bdev(dev_t *);
+void free_anon_bdev(dev_t);
+struct super_block *sget(struct file_system_type *type,
+			int (*test)(struct super_block *,void *),
+			int (*set)(struct super_block *,void *),
+			int flags, void *data);
+extern struct dentry *mount_pseudo(struct file_system_type *, char *,
+	const struct super_operations *ops,
+	const struct dentry_operations *dops,
+	unsigned long);
+
+/* Alas, no aliases. Too much hassle with bringing module.h everywhere */
+#define fops_get(fops) \
+	(((fops) && try_module_get((fops)->owner) ? (fops) : NULL))
+#define fops_put(fops) \
+	do { if (fops) module_put((fops)->owner); } while(0)
+/*
+ * This one is to be used *ONLY* from ->open() instances.
+ * fops must be non-NULL, pinned down *and* module dependencies
+ * should be sufficient to pin the caller down as well.
+ */
+#define replace_fops(f, fops) \
+	do {	\
+		struct file *__file = (f); \
+		fops_put(__file->f_op); \
+		BUG_ON(!(__file->f_op = (fops))); \
+	} while(0)
+
+extern int register_filesystem(struct file_system_type *);
+extern int unregister_filesystem(struct file_system_type *);
+extern struct vfsmount *kern_mount_data(struct file_system_type *, void *data);
+#define kern_mount(type) kern_mount_data(type, NULL)
+extern void kern_unmount(struct vfsmount *mnt);
+extern int may_umount_tree(struct vfsmount *);
+extern int may_umount(struct vfsmount *);
+extern long do_mount(const char *, const char __user *,
+		     const char *, unsigned long, void *);
+extern struct vfsmount *collect_mounts(struct path *);
+extern void drop_collected_mounts(struct vfsmount *);
+extern int iterate_mounts(int (*)(struct vfsmount *, void *), void *,
+			  struct vfsmount *);
+extern int vfs_statfs(struct path *, struct kstatfs *);
+extern int user_statfs(const char __user *, struct kstatfs *);
+extern int fd_statfs(int, struct kstatfs *);
+extern int vfs_ustat(dev_t, struct kstatfs *);
+extern int freeze_super(struct super_block *super);
+extern int thaw_super(struct super_block *super);
+extern bool our_mnt(struct vfsmount *mnt);
+extern bool fs_fully_visible(struct file_system_type *);
+
+extern int current_umask(void);
+
+extern void ihold(struct inode * inode);
+extern void iput(struct inode *);
+extern int generic_update_time(struct inode *, struct timespec *, int);
+
+static inline struct inode *file_inode(const struct file *f)
+{
+	return f->f_inode;
+}
+
+/* /sys/fs */
+extern struct kobject *fs_kobj;
+
+#define MAX_RW_COUNT (INT_MAX & PAGE_CACHE_MASK)
+
+#define FLOCK_VERIFY_READ  1
+#define FLOCK_VERIFY_WRITE 2
+
+#ifdef CONFIG_FILE_LOCKING
+extern int locks_mandatory_locked(struct file *);
+extern int locks_mandatory_area(int, struct inode *, struct file *, loff_t, size_t);
+
+/*
+ * Candidates for mandatory locking have the setgid bit set
+ * but no group execute bit -  an otherwise meaningless combination.
+ */
+
+static inline int __mandatory_lock(struct inode *ino)
+{
+	return (ino->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID;
+}
+
+/*
+ * ... and these candidates should be on MS_MANDLOCK mounted fs,
+ * otherwise these will be advisory locks
+ */
+
+static inline int mandatory_lock(struct inode *ino)
+{
+	return IS_MANDLOCK(ino) && __mandatory_lock(ino);
+}
+
+static inline int locks_verify_locked(struct file *file)
+{
+	if (mandatory_lock(file_inode(file)))
+		return locks_mandatory_locked(file);
+	return 0;
+}
+
+static inline int locks_verify_truncate(struct inode *inode,
+				    struct file *filp,
+				    loff_t size)
+{
+	if (inode->i_flctx && mandatory_lock(inode))
+		return locks_mandatory_area(
+			FLOCK_VERIFY_WRITE, inode, filp,
+			size < inode->i_size ? size : inode->i_size,
+			(size < inode->i_size ? inode->i_size - size
+			 : size - inode->i_size)
+		);
+	return 0;
+}
+
+static inline int break_lease(struct inode *inode, unsigned int mode)
+{
+	/*
+	 * Since this check is lockless, we must ensure that any refcounts
+	 * taken are done before checking i_flctx->flc_lease. Otherwise, we
+	 * could end up racing with tasks trying to set a new lease on this
+	 * file.
+	 */
+	smp_mb();
+	if (inode->i_flctx && !list_empty_careful(&inode->i_flctx->flc_lease))
+		return __break_lease(inode, mode, FL_LEASE);
+	return 0;
+}
+
+static inline int break_deleg(struct inode *inode, unsigned int mode)
+{
+	/*
+	 * Since this check is lockless, we must ensure that any refcounts
+	 * taken are done before checking i_flctx->flc_lease. Otherwise, we
+	 * could end up racing with tasks trying to set a new lease on this
+	 * file.
+	 */
+	smp_mb();
+	if (inode->i_flctx && !list_empty_careful(&inode->i_flctx->flc_lease))
+		return __break_lease(inode, mode, FL_DELEG);
+	return 0;
+}
+
+static inline int try_break_deleg(struct inode *inode, struct inode **delegated_inode)
+{
+	int ret;
+
+	ret = break_deleg(inode, O_WRONLY|O_NONBLOCK);
+	if (ret == -EWOULDBLOCK && delegated_inode) {
+		*delegated_inode = inode;
+		ihold(inode);
+	}
+	return ret;
+}
+
+static inline int break_deleg_wait(struct inode **delegated_inode)
+{
+	int ret;
+
+	ret = break_deleg(*delegated_inode, O_WRONLY);
+	iput(*delegated_inode);
+	*delegated_inode = NULL;
+	return ret;
+}
+
+static inline int break_layout(struct inode *inode, bool wait)
+{
+	smp_mb();
+	if (inode->i_flctx && !list_empty_careful(&inode->i_flctx->flc_lease))
+		return __break_lease(inode,
+				wait ? O_WRONLY : O_WRONLY | O_NONBLOCK,
+				FL_LAYOUT);
+	return 0;
+}
+
+#else /* !CONFIG_FILE_LOCKING */
+static inline int locks_mandatory_locked(struct file *file)
+{
+	return 0;
+}
+
+static inline int locks_mandatory_area(int rw, struct inode *inode,
+				       struct file *filp, loff_t offset,
+				       size_t count)
+{
+	return 0;
+}
+
+static inline int __mandatory_lock(struct inode *inode)
+{
+	return 0;
+}
+
+static inline int mandatory_lock(struct inode *inode)
+{
+	return 0;
+}
+
+static inline int locks_verify_locked(struct file *file)
+{
+	return 0;
+}
+
+static inline int locks_verify_truncate(struct inode *inode, struct file *filp,
+					size_t size)
+{
+	return 0;
+}
+
+static inline int break_lease(struct inode *inode, unsigned int mode)
+{
+	return 0;
+}
+
+static inline int break_deleg(struct inode *inode, unsigned int mode)
+{
+	return 0;
+}
+
+static inline int try_break_deleg(struct inode *inode, struct inode **delegated_inode)
+{
+	return 0;
+}
+
+static inline int break_deleg_wait(struct inode **delegated_inode)
+{
+	BUG();
+	return 0;
+}
+
+static inline int break_layout(struct inode *inode, bool wait)
+{
+	return 0;
+}
+
+#endif /* CONFIG_FILE_LOCKING */
+
+/* fs/open.c */
+struct audit_names;
+struct filename {
+	const char		*name;	/* pointer to actual string */
+	const __user char	*uptr;	/* original userland pointer */
+	struct audit_names	*aname;
+	int			refcnt;
+	bool			separate; /* should "name" be freed? */
+};
+
+extern long vfs_truncate(struct path *, loff_t);
+extern int do_truncate(struct dentry *, loff_t start, unsigned int time_attrs,
+		       struct file *filp);
+extern int vfs_fallocate(struct file *file, int mode, loff_t offset,
+			loff_t len);
+extern long do_sys_open(int dfd, const char __user *filename, int flags,
+			umode_t mode);
+extern struct file *file_open_name(struct filename *, int, umode_t);
+extern struct file *filp_open(const char *, int, umode_t);
+extern struct file *file_open_root(struct dentry *, struct vfsmount *,
+				   const char *, int);
+extern int vfs_open(const struct path *, struct file *, const struct cred *);
+extern struct file * dentry_open(const struct path *, int, const struct cred *);
+extern int filp_close(struct file *, fl_owner_t id);
+
+extern struct filename *getname_flags(const char __user *, int, int *);
+extern struct filename *getname(const char __user *);
+extern struct filename *getname_kernel(const char *);
+extern void putname(struct filename *name);
+
+enum {
+	FILE_CREATED = 1,
+	FILE_OPENED = 2
+};
+extern int finish_open(struct file *file, struct dentry *dentry,
+			int (*open)(struct inode *, struct file *),
+			int *opened);
+extern int finish_no_open(struct file *file, struct dentry *dentry);
+
+/* fs/ioctl.c */
+
+extern int ioctl_preallocate(struct file *filp, void __user *argp);
+
+/* fs/dcache.c */
+extern void __init vfs_caches_init_early(void);
+extern void __init vfs_caches_init(unsigned long);
+
+extern struct kmem_cache *names_cachep;
+
+#define __getname()		kmem_cache_alloc(names_cachep, GFP_KERNEL)
+#define __putname(name)		kmem_cache_free(names_cachep, (void *)(name))
+
+#ifdef CONFIG_BLOCK
+extern int register_blkdev(unsigned int, const char *);
+extern void unregister_blkdev(unsigned int, const char *);
+extern struct block_device *bdget(dev_t);
+extern struct block_device *bdgrab(struct block_device *bdev);
+extern void bd_set_size(struct block_device *, loff_t size);
+extern void bd_forget(struct inode *inode);
+extern void bdput(struct block_device *);
+extern void invalidate_bdev(struct block_device *);
+extern void iterate_bdevs(void (*)(struct block_device *, void *), void *);
+extern int sync_blockdev(struct block_device *bdev);
+extern void kill_bdev(struct block_device *);
+extern struct super_block *freeze_bdev(struct block_device *);
+extern void emergency_thaw_all(void);
+extern int thaw_bdev(struct block_device *bdev, struct super_block *sb);
+extern int fsync_bdev(struct block_device *);
+extern int sb_is_blkdev_sb(struct super_block *sb);
+#else
+static inline void bd_forget(struct inode *inode) {}
+static inline int sync_blockdev(struct block_device *bdev) { return 0; }
+static inline void kill_bdev(struct block_device *bdev) {}
+static inline void invalidate_bdev(struct block_device *bdev) {}
+
+static inline struct super_block *freeze_bdev(struct block_device *sb)
+{
+	return NULL;
+}
+
+static inline int thaw_bdev(struct block_device *bdev, struct super_block *sb)
+{
+	return 0;
+}
+
+static inline void iterate_bdevs(void (*f)(struct block_device *, void *), void *arg)
+{
+}
+
+static inline int sb_is_blkdev_sb(struct super_block *sb)
+{
+	return 0;
+}
+#endif
+extern int sync_filesystem(struct super_block *);
+extern const struct file_operations def_blk_fops;
+extern const struct file_operations def_chr_fops;
+#ifdef CONFIG_BLOCK
+extern int ioctl_by_bdev(struct block_device *, unsigned, unsigned long);
+extern int blkdev_ioctl(struct block_device *, fmode_t, unsigned, unsigned long);
+extern long compat_blkdev_ioctl(struct file *, unsigned, unsigned long);
+extern int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder);
+extern struct block_device *blkdev_get_by_path(const char *path, fmode_t mode,
+					       void *holder);
+extern struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode,
+					      void *holder);
+extern void blkdev_put(struct block_device *bdev, fmode_t mode);
+#ifdef CONFIG_SYSFS
+extern int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk);
+extern void bd_unlink_disk_holder(struct block_device *bdev,
+				  struct gendisk *disk);
+#else
+static inline int bd_link_disk_holder(struct block_device *bdev,
+				      struct gendisk *disk)
+{
+	return 0;
+}
+static inline void bd_unlink_disk_holder(struct block_device *bdev,
+					 struct gendisk *disk)
+{
+}
+#endif
+#endif
+
+/* fs/char_dev.c */
+#define CHRDEV_MAJOR_HASH_SIZE	255
+extern int alloc_chrdev_region(dev_t *, unsigned, unsigned, const char *);
+extern int register_chrdev_region(dev_t, unsigned, const char *);
+extern int __register_chrdev(unsigned int major, unsigned int baseminor,
+			     unsigned int count, const char *name,
+			     const struct file_operations *fops);
+extern void __unregister_chrdev(unsigned int major, unsigned int baseminor,
+				unsigned int count, const char *name);
+extern void unregister_chrdev_region(dev_t, unsigned);
+extern void chrdev_show(struct seq_file *,off_t);
+
+static inline int register_chrdev(unsigned int major, const char *name,
+				  const struct file_operations *fops)
+{
+	return __register_chrdev(major, 0, 256, name, fops);
+}
+
+static inline void unregister_chrdev(unsigned int major, const char *name)
+{
+	__unregister_chrdev(major, 0, 256, name);
+}
+
+/* fs/block_dev.c */
+#define BDEVNAME_SIZE	32	/* Largest string for a blockdev identifier */
+#define BDEVT_SIZE	10	/* Largest string for MAJ:MIN for blkdev */
+
+#ifdef CONFIG_BLOCK
+#define BLKDEV_MAJOR_HASH_SIZE	255
+extern const char *__bdevname(dev_t, char *buffer);
+extern const char *bdevname(struct block_device *bdev, char *buffer);
+extern struct block_device *lookup_bdev(const char *);
+extern void blkdev_show(struct seq_file *,off_t);
+
+#else
+#define BLKDEV_MAJOR_HASH_SIZE	0
+#endif
+
+extern void init_special_inode(struct inode *, umode_t, dev_t);
+
+/* Invalid inode operations -- fs/bad_inode.c */
+extern void make_bad_inode(struct inode *);
+extern int is_bad_inode(struct inode *);
+
+#ifdef CONFIG_BLOCK
+/*
+ * return READ, READA, or WRITE
+ */
+#define bio_rw(bio)		((bio)->bi_rw & (RW_MASK | RWA_MASK))
+
+/*
+ * return data direction, READ or WRITE
+ */
+#define bio_data_dir(bio)	((bio)->bi_rw & 1)
+
+extern void check_disk_size_change(struct gendisk *disk,
+				   struct block_device *bdev);
+extern int revalidate_disk(struct gendisk *);
+extern int check_disk_change(struct block_device *);
+extern int __invalidate_device(struct block_device *, bool);
+extern int invalidate_partition(struct gendisk *, int);
+#endif
+unsigned long invalidate_mapping_pages(struct address_space *mapping,
+					pgoff_t start, pgoff_t end);
+
+static inline void invalidate_remote_inode(struct inode *inode)
+{
+	if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
+	    S_ISLNK(inode->i_mode))
+		invalidate_mapping_pages(inode->i_mapping, 0, -1);
+}
+extern int invalidate_inode_pages2(struct address_space *mapping);
+extern int invalidate_inode_pages2_range(struct address_space *mapping,
+					 pgoff_t start, pgoff_t end);
+extern int write_inode_now(struct inode *, int);
+extern int filemap_fdatawrite(struct address_space *);
+extern int filemap_flush(struct address_space *);
+extern int filemap_fdatawait(struct address_space *);
+extern int filemap_fdatawait_range(struct address_space *, loff_t lstart,
+				   loff_t lend);
+extern int filemap_write_and_wait(struct address_space *mapping);
+extern int filemap_write_and_wait_range(struct address_space *mapping,
+				        loff_t lstart, loff_t lend);
+extern int __filemap_fdatawrite_range(struct address_space *mapping,
+				loff_t start, loff_t end, int sync_mode);
+extern int filemap_fdatawrite_range(struct address_space *mapping,
+				loff_t start, loff_t end);
+
+extern int vfs_fsync_range(struct file *file, loff_t start, loff_t end,
+			   int datasync);
+extern int vfs_fsync(struct file *file, int datasync);
+static inline int generic_write_sync(struct file *file, loff_t pos, loff_t count)
+{
+	if (!(file->f_flags & O_DSYNC) && !IS_SYNC(file->f_mapping->host))
+		return 0;
+	return vfs_fsync_range(file, pos, pos + count - 1,
+			       (file->f_flags & __O_SYNC) ? 0 : 1);
+}
+extern void emergency_sync(void);
+extern void emergency_remount(void);
+#ifdef CONFIG_BLOCK
+extern sector_t bmap(struct inode *, sector_t);
+#endif
+extern int notify_change(struct dentry *, struct iattr *, struct inode **);
+extern int inode_permission(struct inode *, int);
+extern int __inode_permission(struct inode *, int);
+extern int generic_permission(struct inode *, int);
+extern int __check_sticky(struct inode *dir, struct inode *inode);
+
+static inline bool execute_ok(struct inode *inode)
+{
+	return (inode->i_mode & S_IXUGO) || S_ISDIR(inode->i_mode);
+}
+
+static inline void file_start_write(struct file *file)
+{
+	if (!S_ISREG(file_inode(file)->i_mode))
+		return;
+	__sb_start_write(file_inode(file)->i_sb, SB_FREEZE_WRITE, true);
+}
+
+static inline bool file_start_write_trylock(struct file *file)
+{
+	if (!S_ISREG(file_inode(file)->i_mode))
+		return true;
+	return __sb_start_write(file_inode(file)->i_sb, SB_FREEZE_WRITE, false);
+}
+
+static inline void file_end_write(struct file *file)
+{
+	if (!S_ISREG(file_inode(file)->i_mode))
+		return;
+	__sb_end_write(file_inode(file)->i_sb, SB_FREEZE_WRITE);
+}
+
+/*
+ * get_write_access() gets write permission for a file.
+ * put_write_access() releases this write permission.
+ * This is used for regular files.
+ * We cannot support write (and maybe mmap read-write shared) accesses and
+ * MAP_DENYWRITE mmappings simultaneously. The i_writecount field of an inode
+ * can have the following values:
+ * 0: no writers, no VM_DENYWRITE mappings
+ * < 0: (-i_writecount) vm_area_structs with VM_DENYWRITE set exist
+ * > 0: (i_writecount) users are writing to the file.
+ *
+ * Normally we operate on that counter with atomic_{inc,dec} and it's safe
+ * except for the cases where we don't hold i_writecount yet. Then we need to
+ * use {get,deny}_write_access() - these functions check the sign and refuse
+ * to do the change if sign is wrong.
+ */
+static inline int get_write_access(struct inode *inode)
+{
+	return atomic_inc_unless_negative(&inode->i_writecount) ? 0 : -ETXTBSY;
+}
+static inline int deny_write_access(struct file *file)
+{
+	struct inode *inode = file_inode(file);
+	return atomic_dec_unless_positive(&inode->i_writecount) ? 0 : -ETXTBSY;
+}
+static inline void put_write_access(struct inode * inode)
+{
+	atomic_dec(&inode->i_writecount);
+}
+static inline void allow_write_access(struct file *file)
+{
+	if (file)
+		atomic_inc(&file_inode(file)->i_writecount);
+}
+static inline bool inode_is_open_for_write(const struct inode *inode)
+{
+	return atomic_read(&inode->i_writecount) > 0;
+}
+
+#ifdef CONFIG_IMA
+static inline void i_readcount_dec(struct inode *inode)
+{
+	BUG_ON(!atomic_read(&inode->i_readcount));
+	atomic_dec(&inode->i_readcount);
+}
+static inline void i_readcount_inc(struct inode *inode)
+{
+	atomic_inc(&inode->i_readcount);
+}
+#else
+static inline void i_readcount_dec(struct inode *inode)
+{
+	return;
+}
+static inline void i_readcount_inc(struct inode *inode)
+{
+	return;
+}
+#endif
+extern int do_pipe_flags(int *, int);
+
+extern int kernel_read(struct file *, loff_t, char *, unsigned long);
+extern ssize_t kernel_write(struct file *, const char *, size_t, loff_t);
+extern ssize_t __kernel_write(struct file *, const char *, size_t, loff_t *);
+extern struct file * open_exec(const char *);
+ 
+/* fs/dcache.c -- generic fs support functions */
+extern int is_subdir(struct dentry *, struct dentry *);
+extern int path_is_under(struct path *, struct path *);
+
+#include <linux/err.h>
+
+/* needed for stackable file system support */
+extern loff_t default_llseek(struct file *file, loff_t offset, int whence);
+
+extern loff_t vfs_llseek(struct file *file, loff_t offset, int whence);
+
+extern int inode_init_always(struct super_block *, struct inode *);
+extern void inode_init_once(struct inode *);
+extern void address_space_init_once(struct address_space *mapping);
+extern struct inode * igrab(struct inode *);
+extern ino_t iunique(struct super_block *, ino_t);
+extern int inode_needs_sync(struct inode *inode);
+extern int generic_delete_inode(struct inode *inode);
+static inline int generic_drop_inode(struct inode *inode)
+{
+	return !inode->i_nlink || inode_unhashed(inode);
+}
+
+extern struct inode *ilookup5_nowait(struct super_block *sb,
+		unsigned long hashval, int (*test)(struct inode *, void *),
+		void *data);
+extern struct inode *ilookup5(struct super_block *sb, unsigned long hashval,
+		int (*test)(struct inode *, void *), void *data);
+extern struct inode *ilookup(struct super_block *sb, unsigned long ino);
+
+extern struct inode * iget5_locked(struct super_block *, unsigned long, int (*test)(struct inode *, void *), int (*set)(struct inode *, void *), void *);
+extern struct inode * iget_locked(struct super_block *, unsigned long);
+extern struct inode *find_inode_nowait(struct super_block *,
+				       unsigned long,
+				       int (*match)(struct inode *,
+						    unsigned long, void *),
+				       void *data);
+extern int insert_inode_locked4(struct inode *, unsigned long, int (*test)(struct inode *, void *), void *);
+extern int insert_inode_locked(struct inode *);
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+extern void lockdep_annotate_inode_mutex_key(struct inode *inode);
+#else
+static inline void lockdep_annotate_inode_mutex_key(struct inode *inode) { };
+#endif
+extern void unlock_new_inode(struct inode *);
+extern unsigned int get_next_ino(void);
+
+extern void __iget(struct inode * inode);
+extern void iget_failed(struct inode *);
+extern void clear_inode(struct inode *);
+extern void __destroy_inode(struct inode *);
+extern struct inode *new_inode_pseudo(struct super_block *sb);
+extern struct inode *new_inode(struct super_block *sb);
+extern void free_inode_nonrcu(struct inode *inode);
+extern int should_remove_suid(struct dentry *);
+extern int file_remove_suid(struct file *);
+
+extern void __insert_inode_hash(struct inode *, unsigned long hashval);
+static inline void insert_inode_hash(struct inode *inode)
+{
+	__insert_inode_hash(inode, inode->i_ino);
+}
+
+extern void __remove_inode_hash(struct inode *);
+static inline void remove_inode_hash(struct inode *inode)
+{
+	if (!inode_unhashed(inode))
+		__remove_inode_hash(inode);
+}
+
+extern void inode_sb_list_add(struct inode *inode);
+
+#ifdef CONFIG_BLOCK
+extern void submit_bio(int, struct bio *);
+extern int bdev_read_only(struct block_device *);
+#endif
+extern int set_blocksize(struct block_device *, int);
+extern int sb_set_blocksize(struct super_block *, int);
+extern int sb_min_blocksize(struct super_block *, int);
+
+extern int generic_file_mmap(struct file *, struct vm_area_struct *);
+extern int generic_file_readonly_mmap(struct file *, struct vm_area_struct *);
+int generic_write_checks(struct file *file, loff_t *pos, size_t *count, int isblk);
+extern ssize_t generic_file_read_iter(struct kiocb *, struct iov_iter *);
+extern ssize_t __generic_file_write_iter(struct kiocb *, struct iov_iter *);
+extern ssize_t generic_file_write_iter(struct kiocb *, struct iov_iter *);
+extern ssize_t generic_file_direct_write(struct kiocb *, struct iov_iter *, loff_t);
+extern ssize_t generic_perform_write(struct file *, struct iov_iter *, loff_t);
+extern ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos);
+extern ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos);
+extern ssize_t new_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos);
+extern ssize_t new_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos);
+
+ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos);
+ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos);
+
+/* fs/block_dev.c */
+extern ssize_t blkdev_read_iter(struct kiocb *iocb, struct iov_iter *to);
+extern ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from);
+extern int blkdev_fsync(struct file *filp, loff_t start, loff_t end,
+			int datasync);
+extern void block_sync_page(struct page *page);
+
+/* fs/splice.c */
+extern ssize_t generic_file_splice_read(struct file *, loff_t *,
+		struct pipe_inode_info *, size_t, unsigned int);
+extern ssize_t default_file_splice_read(struct file *, loff_t *,
+		struct pipe_inode_info *, size_t, unsigned int);
+extern ssize_t iter_file_splice_write(struct pipe_inode_info *,
+		struct file *, loff_t *, size_t, unsigned int);
+extern ssize_t generic_splice_sendpage(struct pipe_inode_info *pipe,
+		struct file *out, loff_t *, size_t len, unsigned int flags);
+extern long do_splice_direct(struct file *in, loff_t *ppos, struct file *out,
+		loff_t *opos, size_t len, unsigned int flags);
+
+
+extern void
+file_ra_state_init(struct file_ra_state *ra, struct address_space *mapping);
+extern loff_t noop_llseek(struct file *file, loff_t offset, int whence);
+extern loff_t no_llseek(struct file *file, loff_t offset, int whence);
+extern loff_t vfs_setpos(struct file *file, loff_t offset, loff_t maxsize);
+extern loff_t generic_file_llseek(struct file *file, loff_t offset, int whence);
+extern loff_t generic_file_llseek_size(struct file *file, loff_t offset,
+		int whence, loff_t maxsize, loff_t eof);
+extern loff_t fixed_size_llseek(struct file *file, loff_t offset,
+		int whence, loff_t size);
+extern int generic_file_open(struct inode * inode, struct file * filp);
+extern int nonseekable_open(struct inode * inode, struct file * filp);
+
+ssize_t dax_do_io(int rw, struct kiocb *, struct inode *, struct iov_iter *,
+		loff_t, get_block_t, dio_iodone_t, int flags);
+int dax_clear_blocks(struct inode *, sector_t block, long size);
+int dax_zero_page_range(struct inode *, loff_t from, unsigned len, get_block_t);
+int dax_truncate_page(struct inode *, loff_t from, get_block_t);
+int dax_fault(struct vm_area_struct *, struct vm_fault *, get_block_t);
+#define dax_mkwrite(vma, vmf, gb)	dax_fault(vma, vmf, gb)
+
+#ifdef CONFIG_BLOCK
+typedef void (dio_submit_t)(int rw, struct bio *bio, struct inode *inode,
+			    loff_t file_offset);
+
+enum {
+	/* need locking between buffered and direct access */
+	DIO_LOCKING	= 0x01,
+
+	/* filesystem does not support filling holes */
+	DIO_SKIP_HOLES	= 0x02,
+
+	/* filesystem can handle aio writes beyond i_size */
+	DIO_ASYNC_EXTEND = 0x04,
+};
+
+void dio_end_io(struct bio *bio, int error);
+
+ssize_t __blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode,
+	struct block_device *bdev, struct iov_iter *iter, loff_t offset,
+	get_block_t get_block, dio_iodone_t end_io,
+	dio_submit_t submit_io,	int flags);
+
+static inline ssize_t blockdev_direct_IO(int rw, struct kiocb *iocb,
+		struct inode *inode, struct iov_iter *iter, loff_t offset,
+		get_block_t get_block)
+{
+	return __blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iter,
+				    offset, get_block, NULL, NULL,
+				    DIO_LOCKING | DIO_SKIP_HOLES);
+}
+#endif
+
+void inode_dio_wait(struct inode *inode);
+void inode_dio_done(struct inode *inode);
+
+extern void inode_set_flags(struct inode *inode, unsigned int flags,
+			    unsigned int mask);
+
+extern const struct file_operations generic_ro_fops;
+
+#define special_file(m) (S_ISCHR(m)||S_ISBLK(m)||S_ISFIFO(m)||S_ISSOCK(m))
+
+extern int readlink_copy(char __user *, int, const char *);
+extern int page_readlink(struct dentry *, char __user *, int);
+extern void *page_follow_link_light(struct dentry *, struct nameidata *);
+extern void page_put_link(struct dentry *, struct nameidata *, void *);
+extern int __page_symlink(struct inode *inode, const char *symname, int len,
+		int nofs);
+extern int page_symlink(struct inode *inode, const char *symname, int len);
+extern const struct inode_operations page_symlink_inode_operations;
+extern void kfree_put_link(struct dentry *, struct nameidata *, void *);
+extern int generic_readlink(struct dentry *, char __user *, int);
+extern void generic_fillattr(struct inode *, struct kstat *);
+int vfs_getattr_nosec(struct path *path, struct kstat *stat);
+extern int vfs_getattr(struct path *, struct kstat *);
+void __inode_add_bytes(struct inode *inode, loff_t bytes);
+void inode_add_bytes(struct inode *inode, loff_t bytes);
+void __inode_sub_bytes(struct inode *inode, loff_t bytes);
+void inode_sub_bytes(struct inode *inode, loff_t bytes);
+loff_t inode_get_bytes(struct inode *inode);
+void inode_set_bytes(struct inode *inode, loff_t bytes);
+
+extern int vfs_readdir(struct file *, filldir_t, void *);
+extern int iterate_dir(struct file *, struct dir_context *);
+
+extern int vfs_stat(const char __user *, struct kstat *);
+extern int vfs_lstat(const char __user *, struct kstat *);
+extern int vfs_fstat(unsigned int, struct kstat *);
+extern int vfs_fstatat(int , const char __user *, struct kstat *, int);
+
+extern int do_vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd,
+		    unsigned long arg);
+extern int __generic_block_fiemap(struct inode *inode,
+				  struct fiemap_extent_info *fieinfo,
+				  loff_t start, loff_t len,
+				  get_block_t *get_block);
+extern int generic_block_fiemap(struct inode *inode,
+				struct fiemap_extent_info *fieinfo, u64 start,
+				u64 len, get_block_t *get_block);
+
+extern void get_filesystem(struct file_system_type *fs);
+extern void put_filesystem(struct file_system_type *fs);
+extern struct file_system_type *get_fs_type(const char *name);
+extern struct super_block *get_super(struct block_device *);
+extern struct super_block *get_super_thawed(struct block_device *);
+extern struct super_block *get_active_super(struct block_device *bdev);
+extern void drop_super(struct super_block *sb);
+extern void iterate_supers(void (*)(struct super_block *, void *), void *);
+extern void iterate_supers_type(struct file_system_type *,
+			        void (*)(struct super_block *, void *), void *);
+
+extern int dcache_dir_open(struct inode *, struct file *);
+extern int dcache_dir_close(struct inode *, struct file *);
+extern loff_t dcache_dir_lseek(struct file *, loff_t, int);
+extern int dcache_readdir(struct file *, struct dir_context *);
+extern int simple_setattr(struct dentry *, struct iattr *);
+extern int simple_getattr(struct vfsmount *, struct dentry *, struct kstat *);
+extern int simple_statfs(struct dentry *, struct kstatfs *);
+extern int simple_open(struct inode *inode, struct file *file);
+extern int simple_link(struct dentry *, struct inode *, struct dentry *);
+extern int simple_unlink(struct inode *, struct dentry *);
+extern int simple_rmdir(struct inode *, struct dentry *);
+extern int simple_rename(struct inode *, struct dentry *, struct inode *, struct dentry *);
+extern int noop_fsync(struct file *, loff_t, loff_t, int);
+extern int simple_empty(struct dentry *);
+extern int simple_readpage(struct file *file, struct page *page);
+extern int simple_write_begin(struct file *file, struct address_space *mapping,
+			loff_t pos, unsigned len, unsigned flags,
+			struct page **pagep, void **fsdata);
+extern int simple_write_end(struct file *file, struct address_space *mapping,
+			loff_t pos, unsigned len, unsigned copied,
+			struct page *page, void *fsdata);
+extern int always_delete_dentry(const struct dentry *);
+extern struct inode *alloc_anon_inode(struct super_block *);
+extern int simple_nosetlease(struct file *, long, struct file_lock **, void **);
+extern const struct dentry_operations simple_dentry_operations;
+
+extern struct dentry *simple_lookup(struct inode *, struct dentry *, unsigned int flags);
+extern ssize_t generic_read_dir(struct file *, char __user *, size_t, loff_t *);
+extern const struct file_operations simple_dir_operations;
+extern const struct inode_operations simple_dir_inode_operations;
+struct tree_descr { char *name; const struct file_operations *ops; int mode; };
+struct dentry *d_alloc_name(struct dentry *, const char *);
+extern int simple_fill_super(struct super_block *, unsigned long, struct tree_descr *);
+extern int simple_pin_fs(struct file_system_type *, struct vfsmount **mount, int *count);
+extern void simple_release_fs(struct vfsmount **mount, int *count);
+
+extern ssize_t simple_read_from_buffer(void __user *to, size_t count,
+			loff_t *ppos, const void *from, size_t available);
+extern ssize_t simple_write_to_buffer(void *to, size_t available, loff_t *ppos,
+		const void __user *from, size_t count);
+
+extern int __generic_file_fsync(struct file *, loff_t, loff_t, int);
+extern int generic_file_fsync(struct file *, loff_t, loff_t, int);
+
+extern int generic_check_addressable(unsigned, u64);
+
+#ifdef CONFIG_MIGRATION
+extern int buffer_migrate_page(struct address_space *,
+				struct page *, struct page *,
+				enum migrate_mode);
+#else
+#define buffer_migrate_page NULL
+#endif
+
+extern int inode_change_ok(const struct inode *, struct iattr *);
+extern int inode_newsize_ok(const struct inode *, loff_t offset);
+extern void setattr_copy(struct inode *inode, const struct iattr *attr);
+
+extern int file_update_time(struct file *file);
+
+extern int generic_show_options(struct seq_file *m, struct dentry *root);
+extern void save_mount_options(struct super_block *sb, char *options);
+extern void replace_mount_options(struct super_block *sb, char *options);
+
+static inline bool io_is_direct(struct file *filp)
+{
+	return (filp->f_flags & O_DIRECT) || IS_DAX(file_inode(filp));
+}
+
+static inline ino_t parent_ino(struct dentry *dentry)
+{
+	ino_t res;
+
+	/*
+	 * Don't strictly need d_lock here? If the parent ino could change
+	 * then surely we'd have a deeper race in the caller?
+	 */
+	spin_lock(&dentry->d_lock);
+	res = dentry->d_parent->d_inode->i_ino;
+	spin_unlock(&dentry->d_lock);
+	return res;
+}
+
+/* Transaction based IO helpers */
+
+/*
+ * An argresp is stored in an allocated page and holds the
+ * size of the argument or response, along with its content
+ */
+struct simple_transaction_argresp {
+	ssize_t size;
+	char data[0];
+};
+
+#define SIMPLE_TRANSACTION_LIMIT (PAGE_SIZE - sizeof(struct simple_transaction_argresp))
+
+char *simple_transaction_get(struct file *file, const char __user *buf,
+				size_t size);
+ssize_t simple_transaction_read(struct file *file, char __user *buf,
+				size_t size, loff_t *pos);
+int simple_transaction_release(struct inode *inode, struct file *file);
+
+void simple_transaction_set(struct file *file, size_t n);
+
+/*
+ * simple attribute files
+ *
+ * These attributes behave similar to those in sysfs:
+ *
+ * Writing to an attribute immediately sets a value, an open file can be
+ * written to multiple times.
+ *
+ * Reading from an attribute creates a buffer from the value that might get
+ * read with multiple read calls. When the attribute has been read
+ * completely, no further read calls are possible until the file is opened
+ * again.
+ *
+ * All attributes contain a text representation of a numeric value
+ * that are accessed with the get() and set() functions.
+ */
+#define DEFINE_SIMPLE_ATTRIBUTE(__fops, __get, __set, __fmt)		\
+static int __fops ## _open(struct inode *inode, struct file *file)	\
+{									\
+	__simple_attr_check_format(__fmt, 0ull);			\
+	return simple_attr_open(inode, file, __get, __set, __fmt);	\
+}									\
+static const struct file_operations __fops = {				\
+	.owner	 = THIS_MODULE,						\
+	.open	 = __fops ## _open,					\
+	.release = simple_attr_release,					\
+	.read	 = simple_attr_read,					\
+	.write	 = simple_attr_write,					\
+	.llseek	 = generic_file_llseek,					\
+}
+
+static inline __printf(1, 2)
+void __simple_attr_check_format(const char *fmt, ...)
+{
+	/* don't do anything, just let the compiler check the arguments; */
+}
+
+int simple_attr_open(struct inode *inode, struct file *file,
+		     int (*get)(void *, u64 *), int (*set)(void *, u64),
+		     const char *fmt);
+int simple_attr_release(struct inode *inode, struct file *file);
+ssize_t simple_attr_read(struct file *file, char __user *buf,
+			 size_t len, loff_t *ppos);
+ssize_t simple_attr_write(struct file *file, const char __user *buf,
+			  size_t len, loff_t *ppos);
+
+struct ctl_table;
+int proc_nr_files(struct ctl_table *table, int write,
+		  void __user *buffer, size_t *lenp, loff_t *ppos);
+int proc_nr_dentry(struct ctl_table *table, int write,
+		  void __user *buffer, size_t *lenp, loff_t *ppos);
+int proc_nr_inodes(struct ctl_table *table, int write,
+		   void __user *buffer, size_t *lenp, loff_t *ppos);
+int __init get_filesystem_list(char *buf);
+
+#define __FMODE_EXEC		((__force int) FMODE_EXEC)
+#define __FMODE_NONOTIFY	((__force int) FMODE_NONOTIFY)
+
+#define ACC_MODE(x) ("\004\002\006\006"[(x)&O_ACCMODE])
+#define OPEN_FMODE(flag) ((__force fmode_t)(((flag + 1) & O_ACCMODE) | \
+					    (flag & __FMODE_NONOTIFY)))
+
+static inline int is_sxid(umode_t mode)
+{
+	return (mode & S_ISUID) || ((mode & S_ISGID) && (mode & S_IXGRP));
+}
+
+static inline int check_sticky(struct inode *dir, struct inode *inode)
+{
+	if (!(dir->i_mode & S_ISVTX))
+		return 0;
+
+	return __check_sticky(dir, inode);
+}
+
+static inline void inode_has_no_xattr(struct inode *inode)
+{
+	if (!is_sxid(inode->i_mode) && (inode->i_sb->s_flags & MS_NOSEC))
+		inode->i_flags |= S_NOSEC;
+}
+
+static inline bool is_root_inode(struct inode *inode)
+{
+	return inode == inode->i_sb->s_root->d_inode;
+}
+
+static inline bool dir_emit(struct dir_context *ctx,
+			    const char *name, int namelen,
+			    u64 ino, unsigned type)
+{
+	return ctx->actor(ctx, name, namelen, ctx->pos, ino, type) == 0;
+}
+static inline bool dir_emit_dot(struct file *file, struct dir_context *ctx)
+{
+	return ctx->actor(ctx, ".", 1, ctx->pos,
+			  file->f_path.dentry->d_inode->i_ino, DT_DIR) == 0;
+}
+static inline bool dir_emit_dotdot(struct file *file, struct dir_context *ctx)
+{
+	return ctx->actor(ctx, "..", 2, ctx->pos,
+			  parent_ino(file->f_path.dentry), DT_DIR) == 0;
+}
+static inline bool dir_emit_dots(struct file *file, struct dir_context *ctx)
+{
+	if (ctx->pos == 0) {
+		if (!dir_emit_dot(file, ctx))
+			return false;
+		ctx->pos = 1;
+	}
+	if (ctx->pos == 1) {
+		if (!dir_emit_dotdot(file, ctx))
+			return false;
+		ctx->pos = 2;
+	}
+	return true;
+}
+static inline bool dir_relax(struct inode *inode)
+{
+	mutex_unlock(&inode->i_mutex);
+	mutex_lock(&inode->i_mutex);
+	return !IS_DEADDIR(inode);
+}
+
+#endif /* _LINUX_FS_H */
diff --git a/compat/include/linux/list_lru.h b/compat/include/linux/list_lru.h
new file mode 100644
index 00000000000..2a6b9947aaa
--- /dev/null
+++ b/compat/include/linux/list_lru.h
@@ -0,0 +1,189 @@
+/*
+ * Copyright (c) 2013 Red Hat, Inc. and Parallels Inc. All rights reserved.
+ * Authors: David Chinner and Glauber Costa
+ *
+ * Generic LRU infrastructure
+ */
+#ifndef _LRU_LIST_H
+#define _LRU_LIST_H
+
+#include <linux/list.h>
+#include <linux/nodemask.h>
+#include <linux/shrinker.h>
+
+struct mem_cgroup;
+
+/* list_lru_walk_cb has to always return one of those */
+enum lru_status {
+	LRU_REMOVED,		/* item removed from list */
+	LRU_REMOVED_RETRY,	/* item removed, but lock has been
+				   dropped and reacquired */
+	LRU_ROTATE,		/* item referenced, give another pass */
+	LRU_SKIP,		/* item cannot be locked, skip */
+	LRU_RETRY,		/* item not freeable. May drop the lock
+				   internally, but has to return locked. */
+};
+
+struct list_lru_one {
+	struct list_head	list;
+	/* may become negative during memcg reparenting */
+	long			nr_items;
+};
+
+struct list_lru_memcg {
+	/* array of per cgroup lists, indexed by memcg_cache_id */
+	struct list_lru_one	*lru[0];
+};
+
+struct list_lru_node {
+	/* protects all lists on the node, including per cgroup */
+	spinlock_t		lock;
+	/* global list, used for the root cgroup in cgroup aware lrus */
+	struct list_lru_one	lru;
+#ifdef CONFIG_MEMCG_KMEM
+	/* for cgroup aware lrus points to per cgroup lists, otherwise NULL */
+	struct list_lru_memcg	*memcg_lrus;
+#endif
+} ____cacheline_aligned_in_smp;
+
+struct list_lru {
+	struct list_lru_node	*node;
+#ifdef CONFIG_MEMCG_KMEM
+	struct list_head	list;
+#endif
+};
+
+void list_lru_destroy(struct list_lru *lru);
+int __list_lru_init(struct list_lru *lru, bool memcg_aware,
+		    struct lock_class_key *key);
+
+#define list_lru_init(lru)		__list_lru_init((lru), false, NULL)
+#define list_lru_init_key(lru, key)	__list_lru_init((lru), false, (key))
+#define list_lru_init_memcg(lru)	__list_lru_init((lru), true, NULL)
+
+int memcg_update_all_list_lrus(int num_memcgs);
+void memcg_drain_all_list_lrus(int src_idx, int dst_idx);
+
+/**
+ * list_lru_add: add an element to the lru list's tail
+ * @list_lru: the lru pointer
+ * @item: the item to be added.
+ *
+ * If the element is already part of a list, this function returns doing
+ * nothing. Therefore the caller does not need to keep state about whether or
+ * not the element already belongs in the list and is allowed to lazy update
+ * it. Note however that this is valid for *a* list, not *this* list. If
+ * the caller organize itself in a way that elements can be in more than
+ * one type of list, it is up to the caller to fully remove the item from
+ * the previous list (with list_lru_del() for instance) before moving it
+ * to @list_lru
+ *
+ * Return value: true if the list was updated, false otherwise
+ */
+bool list_lru_add(struct list_lru *lru, struct list_head *item);
+
+/**
+ * list_lru_del: delete an element to the lru list
+ * @list_lru: the lru pointer
+ * @item: the item to be deleted.
+ *
+ * This function works analogously as list_lru_add in terms of list
+ * manipulation. The comments about an element already pertaining to
+ * a list are also valid for list_lru_del.
+ *
+ * Return value: true if the list was updated, false otherwise
+ */
+bool list_lru_del(struct list_lru *lru, struct list_head *item);
+
+/**
+ * list_lru_count_one: return the number of objects currently held by @lru
+ * @lru: the lru pointer.
+ * @nid: the node id to count from.
+ * @memcg: the cgroup to count from.
+ *
+ * Always return a non-negative number, 0 for empty lists. There is no
+ * guarantee that the list is not updated while the count is being computed.
+ * Callers that want such a guarantee need to provide an outer lock.
+ */
+unsigned long list_lru_count_one(struct list_lru *lru,
+				 int nid, struct mem_cgroup *memcg);
+unsigned long list_lru_count_node(struct list_lru *lru, int nid);
+
+static inline unsigned long list_lru_shrink_count(struct list_lru *lru,
+						  struct shrink_control *sc)
+{
+	return list_lru_count_one(lru, sc->nid, sc->memcg);
+}
+
+static inline unsigned long list_lru_count(struct list_lru *lru)
+{
+	long count = 0;
+	int nid;
+
+	for_each_node_state(nid, N_NORMAL_MEMORY)
+		count += list_lru_count_node(lru, nid);
+
+	return count;
+}
+
+void list_lru_isolate(struct list_lru_one *list, struct list_head *item);
+void list_lru_isolate_move(struct list_lru_one *list, struct list_head *item,
+			   struct list_head *head);
+
+typedef enum lru_status (*list_lru_walk_cb)(struct list_head *item,
+		struct list_lru_one *list, spinlock_t *lock, void *cb_arg);
+
+/**
+ * list_lru_walk_one: walk a list_lru, isolating and disposing freeable items.
+ * @lru: the lru pointer.
+ * @nid: the node id to scan from.
+ * @memcg: the cgroup to scan from.
+ * @isolate: callback function that is resposible for deciding what to do with
+ *  the item currently being scanned
+ * @cb_arg: opaque type that will be passed to @isolate
+ * @nr_to_walk: how many items to scan.
+ *
+ * This function will scan all elements in a particular list_lru, calling the
+ * @isolate callback for each of those items, along with the current list
+ * spinlock and a caller-provided opaque. The @isolate callback can choose to
+ * drop the lock internally, but *must* return with the lock held. The callback
+ * will return an enum lru_status telling the list_lru infrastructure what to
+ * do with the object being scanned.
+ *
+ * Please note that nr_to_walk does not mean how many objects will be freed,
+ * just how many objects will be scanned.
+ *
+ * Return value: the number of objects effectively removed from the LRU.
+ */
+unsigned long list_lru_walk_one(struct list_lru *lru,
+				int nid, struct mem_cgroup *memcg,
+				list_lru_walk_cb isolate, void *cb_arg,
+				unsigned long *nr_to_walk);
+unsigned long list_lru_walk_node(struct list_lru *lru, int nid,
+				 list_lru_walk_cb isolate, void *cb_arg,
+				 unsigned long *nr_to_walk);
+
+static inline unsigned long
+list_lru_shrink_walk(struct list_lru *lru, struct shrink_control *sc,
+		     list_lru_walk_cb isolate, void *cb_arg)
+{
+	return list_lru_walk_one(lru, sc->nid, sc->memcg, isolate, cb_arg,
+				 &sc->nr_to_scan);
+}
+
+static inline unsigned long
+list_lru_walk(struct list_lru *lru, list_lru_walk_cb isolate,
+	      void *cb_arg, unsigned long nr_to_walk)
+{
+	long isolated = 0;
+	int nid;
+
+	for_each_node_state(nid, N_NORMAL_MEMORY) {
+		isolated += list_lru_walk_node(lru, nid, isolate,
+					       cb_arg, &nr_to_walk);
+		if (nr_to_walk <= 0)
+			break;
+	}
+	return isolated;
+}
+#endif /* _LRU_LIST_H */
diff --git a/compat/include/linux/shrinker.h b/compat/include/linux/shrinker.h
new file mode 100644
index 00000000000..4fcacd915d4
--- /dev/null
+++ b/compat/include/linux/shrinker.h
@@ -0,0 +1,72 @@
+#ifndef _LINUX_SHRINKER_H
+#define _LINUX_SHRINKER_H
+
+/*
+ * This struct is used to pass information from page reclaim to the shrinkers.
+ * We consolidate the values for easier extention later.
+ *
+ * The 'gfpmask' refers to the allocation we are currently trying to
+ * fulfil.
+ */
+struct shrink_control {
+	gfp_t gfp_mask;
+
+	/*
+	 * How many objects scan_objects should scan and try to reclaim.
+	 * This is reset before every call, so it is safe for callees
+	 * to modify.
+	 */
+	unsigned long nr_to_scan;
+
+	/* current node being shrunk (for NUMA aware shrinkers) */
+	int nid;
+
+	/* current memcg being shrunk (for memcg aware shrinkers) */
+	struct mem_cgroup *memcg;
+};
+
+#define SHRINK_STOP (~0UL)
+/*
+ * A callback you can register to apply pressure to ageable caches.
+ *
+ * @count_objects should return the number of freeable items in the cache. If
+ * there are no objects to free or the number of freeable items cannot be
+ * determined, it should return 0. No deadlock checks should be done during the
+ * count callback - the shrinker relies on aggregating scan counts that couldn't
+ * be executed due to potential deadlocks to be run at a later call when the
+ * deadlock condition is no longer pending.
+ *
+ * @scan_objects will only be called if @count_objects returned a non-zero
+ * value for the number of freeable objects. The callout should scan the cache
+ * and attempt to free items from the cache. It should then return the number
+ * of objects freed during the scan, or SHRINK_STOP if progress cannot be made
+ * due to potential deadlocks. If SHRINK_STOP is returned, then no further
+ * attempts to call the @scan_objects will be made from the current reclaim
+ * context.
+ *
+ * @flags determine the shrinker abilities, like numa awareness
+ */
+struct shrinker {
+	unsigned long (*count_objects)(struct shrinker *,
+				       struct shrink_control *sc);
+	unsigned long (*scan_objects)(struct shrinker *,
+				      struct shrink_control *sc);
+
+	int seeks;	/* seeks to recreate an obj */
+	long batch;	/* reclaim batch size, 0 = default */
+	unsigned long flags;
+
+	/* These are for internal use */
+	struct list_head list;
+	/* objs pending delete, per node */
+	atomic_long_t *nr_deferred;
+};
+#define DEFAULT_SEEKS 2 /* A good number if you don't know better. */
+
+/* Flags */
+#define SHRINKER_NUMA_AWARE	(1 << 0)
+#define SHRINKER_MEMCG_AWARE	(1 << 1)
+
+extern int register_shrinker(struct shrinker *);
+extern void unregister_shrinker(struct shrinker *);
+#endif
diff --git a/compat/include/linux/uio.h b/compat/include/linux/uio.h
new file mode 100644
index 00000000000..71880299ed4
--- /dev/null
+++ b/compat/include/linux/uio.h
@@ -0,0 +1,142 @@
+/*
+ *	Berkeley style UIO structures	-	Alan Cox 1994.
+ *
+ *		This program is free software; you can redistribute it and/or
+ *		modify it under the terms of the GNU General Public License
+ *		as published by the Free Software Foundation; either version
+ *		2 of the License, or (at your option) any later version.
+ */
+#ifndef __LINUX_UIO_H
+#define __LINUX_UIO_H
+
+#include <linux/kernel.h>
+#include <uapi/linux/uio.h>
+
+struct page;
+
+struct kvec {
+	void *iov_base; /* and that should *never* hold a userland pointer */
+	size_t iov_len;
+};
+
+enum {
+	ITER_IOVEC = 0,
+	ITER_KVEC = 2,
+	ITER_BVEC = 4,
+};
+
+struct iov_iter {
+	int type;
+	size_t iov_offset;
+	size_t count;
+	union {
+		const struct iovec *iov;
+		const struct kvec *kvec;
+		const struct bio_vec *bvec;
+	};
+	unsigned long nr_segs;
+};
+
+/*
+ * Total number of bytes covered by an iovec.
+ *
+ * NOTE that it is not safe to use this function until all the iovec's
+ * segment lengths have been validated.  Because the individual lengths can
+ * overflow a size_t when added together.
+ */
+static inline size_t iov_length(const struct iovec *iov, unsigned long nr_segs)
+{
+	unsigned long seg;
+	size_t ret = 0;
+
+	for (seg = 0; seg < nr_segs; seg++)
+		ret += iov[seg].iov_len;
+	return ret;
+}
+
+static inline struct iovec iov_iter_iovec(const struct iov_iter *iter)
+{
+	return (struct iovec) {
+		.iov_base = iter->iov->iov_base + iter->iov_offset,
+		.iov_len = min(iter->count,
+			       iter->iov->iov_len - iter->iov_offset),
+	};
+}
+
+#define iov_for_each(iov, iter, start)				\
+	if (!((start).type & ITER_BVEC))			\
+	for (iter = (start);					\
+	     (iter).count &&					\
+	     ((iov = iov_iter_iovec(&(iter))), 1);		\
+	     iov_iter_advance(&(iter), (iov).iov_len))
+
+unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to);
+
+size_t iov_iter_copy_from_user_atomic(struct page *page,
+		struct iov_iter *i, unsigned long offset, size_t bytes);
+void iov_iter_advance(struct iov_iter *i, size_t bytes);
+int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes);
+size_t iov_iter_single_seg_count(const struct iov_iter *i);
+size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes,
+			 struct iov_iter *i);
+size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes,
+			 struct iov_iter *i);
+size_t copy_to_iter(void *addr, size_t bytes, struct iov_iter *i);
+size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i);
+size_t copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i);
+size_t iov_iter_zero(size_t bytes, struct iov_iter *);
+unsigned long iov_iter_alignment(const struct iov_iter *i);
+void iov_iter_init(struct iov_iter *i, int direction, const struct iovec *iov,
+			unsigned long nr_segs, size_t count);
+void iov_iter_kvec(struct iov_iter *i, int direction, const struct kvec *kvec,
+			unsigned long nr_segs, size_t count);
+void iov_iter_bvec(struct iov_iter *i, int direction, const struct bio_vec *bvec,
+			unsigned long nr_segs, size_t count);
+ssize_t iov_iter_get_pages(struct iov_iter *i, struct page **pages,
+			size_t maxsize, unsigned maxpages, size_t *start);
+ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, struct page ***pages,
+			size_t maxsize, size_t *start);
+int iov_iter_npages(const struct iov_iter *i, int maxpages);
+
+const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags);
+
+static inline size_t iov_iter_count(struct iov_iter *i)
+{
+	return i->count;
+}
+
+static inline bool iter_is_iovec(struct iov_iter *i)
+{
+	return !(i->type & (ITER_BVEC | ITER_KVEC));
+}
+
+/*
+ * Cap the iov_iter by given limit; note that the second argument is
+ * *not* the new size - it's upper limit for such.  Passing it a value
+ * greater than the amount of data in iov_iter is fine - it'll just do
+ * nothing in that case.
+ */
+static inline void iov_iter_truncate(struct iov_iter *i, u64 count)
+{
+	/*
+	 * count doesn't have to fit in size_t - comparison extends both
+	 * operands to u64 here and any value that would be truncated by
+	 * conversion in assignement is by definition greater than all
+	 * values of size_t, including old i->count.
+	 */
+	if (i->count > count)
+		i->count = count;
+}
+
+/*
+ * reexpand a previously truncated iterator; count must be no more than how much
+ * we had shrunk it.
+ */
+static inline void iov_iter_reexpand(struct iov_iter *i, size_t count)
+{
+	i->count = count;
+}
+size_t csum_and_copy_to_iter(void *addr, size_t bytes, __wsum *csum, struct iov_iter *i);
+size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, struct iov_iter *i);
+
+#endif
diff --git a/compat/lib/Makefile b/compat/lib/Makefile
new file mode 100644
index 00000000000..b7f32e73e60
--- /dev/null
+++ b/compat/lib/Makefile
@@ -0,0 +1 @@
+obj-y += iov_iter.o
diff --git a/compat/lib/iov_iter.c b/compat/lib/iov_iter.c
new file mode 100644
index 00000000000..c826359646e
--- /dev/null
+++ b/compat/lib/iov_iter.c
@@ -0,0 +1,38 @@
+#include <linux/export.h>
+#include <linux/uio.h>
+#include <linux/pagemap.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <net/checksum.h>
+
+void iov_iter_init(struct iov_iter *i, int direction,
+			const struct iovec *iov, unsigned long nr_segs,
+			size_t count)
+{
+	/* It will get better.  Eventually... */
+	if (segment_eq(get_fs(), KERNEL_DS)) {
+		direction |= ITER_KVEC;
+		i->type = direction;
+		i->kvec = (struct kvec *)iov;
+	} else {
+		i->type = direction;
+		i->iov = iov;
+	}
+	i->nr_segs = nr_segs;
+	i->iov_offset = 0;
+	i->count = count;
+}
+EXPORT_SYMBOL(iov_iter_init);
+
+void iov_iter_kvec(struct iov_iter *i, int direction,
+			const struct kvec *kvec, unsigned long nr_segs,
+			size_t count)
+{
+	BUG_ON(!(direction & ITER_KVEC));
+	i->type = direction;
+	i->kvec = kvec;
+	i->nr_segs = nr_segs;
+	i->iov_offset = 0;
+	i->count = count;
+}
+EXPORT_SYMBOL(iov_iter_kvec);
diff --git a/ipc/kdbus/Makefile b/ipc/kdbus/Makefile
index 7ee9271e144..8385c6849f8 100644
--- a/ipc/kdbus/Makefile
+++ b/ipc/kdbus/Makefile
@@ -1,3 +1,5 @@
+override LINUXINCLUDE := $(patsubst -Iinclude, -Icompat/include -Iinclude , $(LINUXINCLUDE))
+
 kdbus-y := \
 	bus.o \
 	connection.o \