SPDX-License-Identifier: GPL-2.0
aufs5.2 base patch

diff --git a/MAINTAINERS b/MAINTAINERS
index 677ef41cb012..c2a7491ddc68 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2769,6 +2769,19 @@ F:	include/linux/audit.h
 F:	include/uapi/linux/audit.h
 F:	kernel/audit*
 
+AUFS (advanced multi layered unification filesystem) FILESYSTEM
+M:	"J. R. Okajima" <hooanon05g@gmail.com>
+L:	aufs-users@lists.sourceforge.net (members only)
+L:	linux-unionfs@vger.kernel.org
+W:	http://aufs.sourceforge.net
+T:	git://github.com/sfjro/aufs4-linux.git
+S:	Supported
+F:	Documentation/filesystems/aufs/
+F:	Documentation/ABI/testing/debugfs-aufs
+F:	Documentation/ABI/testing/sysfs-aufs
+F:	fs/aufs/
+F:	include/uapi/linux/aufs_type.h
+
 AUXILIARY DISPLAY DRIVERS
 M:	Miguel Ojeda Sandonis <miguel.ojeda.sandonis@gmail.com>
 S:	Maintained
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index f11b7dc16e9d..1b723737592b 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -746,6 +746,24 @@ static int loop_change_fd(struct loop_device *lo, struct block_device *bdev,
 	return error;
 }
 
+/*
+ * for AUFS
+ * no get/put for file.
+ */
+struct file *loop_backing_file(struct super_block *sb)
+{
+	struct file *ret;
+	struct loop_device *l;
+
+	ret = NULL;
+	if (MAJOR(sb->s_dev) == LOOP_MAJOR) {
+		l = sb->s_bdev->bd_disk->private_data;
+		ret = l->lo_backing_file;
+	}
+	return ret;
+}
+EXPORT_SYMBOL_GPL(loop_backing_file);
+
 /* loop sysfs attributes */
 
 static ssize_t loop_attr_show(struct device *dev, char *page,
diff --git a/fs/dcache.c b/fs/dcache.c
index c435398f2c81..a688a042d022 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1247,7 +1247,7 @@ enum d_walk_ret {
  *
  * The @enter() callbacks are called with d_lock held.
  */
-static void d_walk(struct dentry *parent, void *data,
+void d_walk(struct dentry *parent, void *data,
 		   enum d_walk_ret (*enter)(void *, struct dentry *))
 {
 	struct dentry *this_parent;
diff --git a/fs/fcntl.c b/fs/fcntl.c
index 3d40771e8e7c..d62303c5472a 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -32,7 +32,7 @@
 
 #define SETFL_MASK (O_APPEND | O_NONBLOCK | O_NDELAY | O_DIRECT | O_NOATIME)
 
-static int setfl(int fd, struct file * filp, unsigned long arg)
+int setfl(int fd, struct file * filp, unsigned long arg)
 {
 	struct inode * inode = file_inode(filp);
 	int error = 0;
@@ -63,6 +63,8 @@ static int setfl(int fd, struct file * filp, unsigned long arg)
 
 	if (filp->f_op->check_flags)
 		error = filp->f_op->check_flags(arg);
+	if (!error && filp->f_op->setfl)
+		error = filp->f_op->setfl(filp, arg);
 	if (error)
 		return error;
 
diff --git a/fs/inode.c b/fs/inode.c
index 2bf21e2c90fc..9b908c37971f 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -1670,7 +1670,7 @@ EXPORT_SYMBOL(generic_update_time);
  * This does the actual work of updating an inodes time or version.  Must have
  * had called mnt_want_write() before calling this.
  */
-static int update_time(struct inode *inode, struct timespec64 *time, int flags)
+int update_time(struct inode *inode, struct timespec64 *time, int flags)
 {
 	int (*update_time)(struct inode *, struct timespec64 *, int);
 
diff --git a/fs/namespace.c b/fs/namespace.c
index 6fbc9126367a..101dda59f39c 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -770,6 +770,12 @@ static inline int check_mnt(struct mount *mnt)
 	return mnt->mnt_ns == current->nsproxy->mnt_ns;
 }
 
+/* for aufs, CONFIG_AUFS_BR_FUSE */
+int is_current_mnt_ns(struct vfsmount *mnt)
+{
+	return check_mnt(real_mount(mnt));
+}
+
 /*
  * vfsmount lock must be held for write
  */
diff --git a/fs/read_write.c b/fs/read_write.c
index c543d965e288..35ab54e0a994 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -498,6 +498,28 @@ static ssize_t __vfs_write(struct file *file, const char __user *p,
 		return -EINVAL;
 }
 
+vfs_readf_t vfs_readf(struct file *file)
+{
+	const struct file_operations *fop = file->f_op;
+
+	if (fop->read)
+		return fop->read;
+	if (fop->read_iter)
+		return new_sync_read;
+	return ERR_PTR(-ENOSYS);
+}
+
+vfs_writef_t vfs_writef(struct file *file)
+{
+	const struct file_operations *fop = file->f_op;
+
+	if (fop->write)
+		return fop->write;
+	if (fop->write_iter)
+		return new_sync_write;
+	return ERR_PTR(-ENOSYS);
+}
+
 ssize_t __kernel_write(struct file *file, const void *buf, size_t count, loff_t *pos)
 {
 	mm_segment_t old_fs;
diff --git a/fs/splice.c b/fs/splice.c
index 14cb602d9a2f..58d2692c5f30 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -834,8 +834,8 @@ EXPORT_SYMBOL(generic_splice_sendpage);
 /*
  * Attempt to initiate a splice from pipe to file.
  */
-static long do_splice_from(struct pipe_inode_info *pipe, struct file *out,
-			   loff_t *ppos, size_t len, unsigned int flags)
+long do_splice_from(struct pipe_inode_info *pipe, struct file *out,
+		    loff_t *ppos, size_t len, unsigned int flags)
 {
 	ssize_t (*splice_write)(struct pipe_inode_info *, struct file *,
 				loff_t *, size_t, unsigned int);
@@ -851,9 +851,9 @@ static long do_splice_from(struct pipe_inode_info *pipe, struct file *out,
 /*
  * Attempt to initiate a splice from a file to a pipe.
  */
-static long do_splice_to(struct file *in, loff_t *ppos,
-			 struct pipe_inode_info *pipe, size_t len,
-			 unsigned int flags)
+long do_splice_to(struct file *in, loff_t *ppos,
+		  struct pipe_inode_info *pipe, size_t len,
+		  unsigned int flags)
 {
 	ssize_t (*splice_read)(struct file *, loff_t *,
 			       struct pipe_inode_info *, size_t, unsigned int);
diff --git a/fs/sync.c b/fs/sync.c
index 4d1ff010bc5a..457f4e4a5cc1 100644
--- a/fs/sync.c
+++ b/fs/sync.c
@@ -28,7 +28,7 @@
  * wait == 1 case since in that case write_inode() functions do
  * sync_dirty_buffer() and thus effectively write one block at a time.
  */
-static int __sync_filesystem(struct super_block *sb, int wait)
+int __sync_filesystem(struct super_block *sb, int wait)
 {
 	if (wait)
 		sync_inodes_sb(sb);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index f7fdfe93e25d..28593b894e7b 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1333,6 +1333,7 @@ extern void fasync_free(struct fasync_struct *);
 /* can be called from interrupts */
 extern void kill_fasync(struct fasync_struct **, int, int);
 
+extern int setfl(int fd, struct file * filp, unsigned long arg);
 extern void __f_setown(struct file *filp, struct pid *, enum pid_type, int force);
 extern int f_setown(struct file *filp, unsigned long arg, int force);
 extern void f_delown(struct file *filp);
@@ -1812,6 +1813,7 @@ struct file_operations {
 	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 (*setfl)(struct file *, unsigned long);
 	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);
@@ -1882,6 +1884,12 @@ ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector,
 			      struct iovec *fast_pointer,
 			      struct iovec **ret_pointer);
 
+typedef ssize_t (*vfs_readf_t)(struct file *, char __user *, size_t, loff_t *);
+typedef ssize_t (*vfs_writef_t)(struct file *, const char __user *, size_t,
+				loff_t *);
+vfs_readf_t vfs_readf(struct file *file);
+vfs_writef_t vfs_writef(struct file *file);
+
 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 *);
@@ -2315,6 +2323,7 @@ extern int current_umask(void);
 extern void ihold(struct inode * inode);
 extern void iput(struct inode *);
 extern int generic_update_time(struct inode *, struct timespec64 *, int);
+extern int update_time(struct inode *, struct timespec64 *, int);
 
 /* /sys/fs */
 extern struct kobject *fs_kobj;
@@ -2603,6 +2612,7 @@ static inline bool sb_is_blkdev_sb(struct super_block *sb)
 	return false;
 }
 #endif
+extern int __sync_filesystem(struct super_block *, int);
 extern int sync_filesystem(struct super_block *);
 extern const struct file_operations def_blk_fops;
 extern const struct file_operations def_chr_fops;
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index 6e2377e6c1d6..5a945d18a72a 100644
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -325,6 +325,8 @@ static inline int lockdep_match_key(struct lockdep_map *lock,
 	return lock->key == key;
 }
 
+struct lock_class *lockdep_hlock_class(struct held_lock *hlock);
+
 /*
  * Acquire a lock.
  *
@@ -463,6 +465,7 @@ struct lockdep_map { };
 
 #define lockdep_depth(tsk)	(0)
 
+#define lockdep_is_held(lock)			(1)
 #define lockdep_is_held_type(l, r)		(1)
 
 #define lockdep_assert_held(l)			do { (void)(l); } while (0)
diff --git a/include/linux/mnt_namespace.h b/include/linux/mnt_namespace.h
index 35942084cd40..24f5fd1a789d 100644
--- a/include/linux/mnt_namespace.h
+++ b/include/linux/mnt_namespace.h
@@ -6,11 +6,14 @@
 struct mnt_namespace;
 struct fs_struct;
 struct user_namespace;
+struct vfsmount;
 
 extern struct mnt_namespace *copy_mnt_ns(unsigned long, struct mnt_namespace *,
 		struct user_namespace *, struct fs_struct *);
 extern void put_mnt_ns(struct mnt_namespace *ns);
 
+extern int is_current_mnt_ns(struct vfsmount *mnt);
+
 extern const struct file_operations proc_mounts_operations;
 extern const struct file_operations proc_mountinfo_operations;
 extern const struct file_operations proc_mountstats_operations;
diff --git a/include/linux/splice.h b/include/linux/splice.h
index 74b4911ac16d..19789fbea567 100644
--- a/include/linux/splice.h
+++ b/include/linux/splice.h
@@ -87,4 +87,10 @@ extern void splice_shrink_spd(struct splice_pipe_desc *);
 
 extern const struct pipe_buf_operations page_cache_pipe_buf_ops;
 extern const struct pipe_buf_operations default_pipe_buf_ops;
+
+extern long do_splice_from(struct pipe_inode_info *pipe, struct file *out,
+			   loff_t *ppos, size_t len, unsigned int flags);
+extern long do_splice_to(struct file *in, loff_t *ppos,
+			 struct pipe_inode_info *pipe, size_t len,
+			 unsigned int flags);
 #endif
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index c47788fa85f9..3c35a1059890 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -152,7 +152,7 @@ static
 #endif
 struct lock_class lock_classes[MAX_LOCKDEP_KEYS];
 
-static inline struct lock_class *hlock_class(struct held_lock *hlock)
+inline struct lock_class *lockdep_hlock_class(struct held_lock *hlock)
 {
 	if (!hlock->class_idx) {
 		/*
@@ -163,6 +163,7 @@ static inline struct lock_class *hlock_class(struct held_lock *hlock)
 	}
 	return lock_classes + hlock->class_idx - 1;
 }
+#define hlock_class(hlock) lockdep_hlock_class(hlock)
 
 #ifdef CONFIG_LOCK_STAT
 static DEFINE_PER_CPU(struct lock_class_stats[MAX_LOCKDEP_KEYS], cpu_lock_stats);