SPDX-License-Identifier: GPL-2.0
aufs5.x-rcN base patch

diff --git a/MAINTAINERS b/MAINTAINERS
index d92f85ca831d3..339cc62f77736 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2983,6 +2983,19 @@ 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
+S:	Supported
+W:	http://aufs.sourceforge.net
+T:	git://github.com/sfjro/aufs4-linux.git
+F:	Documentation/ABI/testing/debugfs-aufs
+F:	Documentation/ABI/testing/sysfs-aufs
+F:	Documentation/filesystems/aufs/
+F:	fs/aufs/
+F:	include/uapi/linux/aufs_type.h
+
 AUXILIARY DISPLAY DRIVERS
 M:	Miguel Ojeda <ojeda@kernel.org>
 S:	Maintained
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index a370cde3ddd49..01ca256575fb2 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -761,6 +761,24 @@ 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 7d24ff7eb2068..3caa7ab4b84f1 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1318,7 +1318,7 @@ 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 dfc72f15be7fc..d8a12eb63961d 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -33,7 +33,7 @@
 
 #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;
@@ -64,6 +64,8 @@ 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 a047ab306f9a8..ba1df0895b69f 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -1772,7 +1772,7 @@ 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)
 {
 	if (inode->i_op->update_time)
 		return inode->i_op->update_time(inode, time, flags);
diff --git a/fs/namespace.c b/fs/namespace.c
index 56bb5a5fdc0d0..540679d7e0434 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -807,6 +807,12 @@ 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/splice.c b/fs/splice.c
index 5dbce4dcc1a7d..3e6ba363b7775 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -759,8 +759,8 @@ static int warn_unsupported(struct file *file, const char *op)
 /*
  * 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)
 {
 	if (unlikely(!out->f_op->splice_write))
 		return warn_unsupported(out, "write");
@@ -770,9 +770,9 @@ 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)
 {
 	unsigned int p_space;
 	int ret;
diff --git a/fs/sync.c b/fs/sync.c
index 1373a610dc784..b7b5a0a0df6ff 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 ec8f3ddf4a6aa..4fa4b24535fde 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1332,6 +1332,7 @@ 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);
@@ -1909,6 +1910,7 @@ 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);
@@ -2428,6 +2430,7 @@ 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;
@@ -2668,6 +2671,7 @@ static inline bool sb_is_blkdev_sb(struct super_block *sb)
 }
 
 void emergency_thaw_all(void);
+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 7b7ebf2e28ec5..20c46305e057e 100644
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -248,6 +248,8 @@ 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.
  *
diff --git a/include/linux/mnt_namespace.h b/include/linux/mnt_namespace.h
index 8f882f5881e87..6b9808f098435 100644
--- a/include/linux/mnt_namespace.h
+++ b/include/linux/mnt_namespace.h
@@ -7,12 +7,15 @@ struct mnt_namespace;
 struct fs_struct;
 struct user_namespace;
 struct ns_common;
+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 struct ns_common *from_mnt_ns(struct mnt_namespace *);
 
+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 a55179fd60fc3..8e21c53cf8831 100644
--- a/include/linux/splice.h
+++ b/include/linux/splice.h
@@ -93,4 +93,10 @@ 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 c6d0c1dc62532..0f557138af3e9 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -188,7 +188,7 @@ static
 struct lock_class lock_classes[MAX_LOCKDEP_KEYS];
 static DECLARE_BITMAP(lock_classes_in_use, 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)
 {
 	unsigned int class_idx = hlock->class_idx;
 
@@ -209,6 +209,7 @@ static inline struct lock_class *hlock_class(struct held_lock *hlock)
 	 */
 	return lock_classes + class_idx;
 }
+#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);