aufs5: kbuild

1/5 [
Author: Bruce Ashfield
Email: bruce.ashfield@gmail.com
Subject: aufs5: kbuild
Date: Thu, 23 Sep 2021 11:06:29 -0400

Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>
]

2/5 [
Author: Bruce Ashfield
Email: bruce.ashfield@gmail.com
Subject: aufs5: base
Date: Thu, 23 Sep 2021 11:07:01 -0400

Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>
]

3/5 [
Author: Bruce Ashfield
Email: bruce.ashfield@gmail.com
Subject: aufs5: mmap
Date: Thu, 23 Sep 2021 11:08:04 -0400

Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>
]

4/5 [
Author: Bruce Ashfield
Email: bruce.ashfield@gmail.com
Subject: aufs5: standalone
Date: Thu, 23 Sep 2021 11:08:37 -0400

Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>
]

5/5 [
Author: Bruce Ashfield
Email: bruce.ashfield@gmail.com
Subject: aufs5: core
Date: Thu, 23 Sep 2021 11:09:25 -0400

Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>
]
Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>

features/aufs/aufs5-base.patch

+From 8ab816dc7b5180bee31b187e07125410c46a7ba2 Mon Sep 17 00:00:00 2001
+From: Bruce Ashfield <bruce.ashfield@gmail.com>
+Date: Thu, 23 Sep 2021 11:07:01 -0400
+Subject: [PATCH 2/5] aufs5: base
+
+Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>
+---
+ MAINTAINERS                   | 13 +++++++++++++
+ drivers/block/loop.c          | 18 ++++++++++++++++++
+ fs/dcache.c                   |  2 +-
+ fs/fcntl.c                    |  4 +++-
+ fs/inode.c                    |  2 +-
+ fs/namespace.c                |  6 ++++++
+ fs/splice.c                   | 10 +++++-----
+ fs/sync.c                     |  2 +-
+ include/linux/fs.h            |  4 ++++
+ include/linux/lockdep.h       |  2 ++
+ include/linux/mnt_namespace.h |  3 +++
+ include/linux/splice.h        |  6 ++++++
+ kernel/locking/lockdep.c      |  3 ++-
+ 13 files changed, 65 insertions(+), 10 deletions(-)
+
+diff --git a/MAINTAINERS b/MAINTAINERS
+index ca6d6fde85cf..236b1d712761 100644
+--- a/MAINTAINERS
++++ b/MAINTAINERS
+@@ -3117,6 +3117,19 @@ F:	include/uapi/linux/audit.h
+ F:	kernel/audit*
+ F:	lib/*audit.c
+ 
++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 7bf4686af774..a62b132cbd55 100644
+--- a/drivers/block/loop.c
++++ b/drivers/block/loop.c
+@@ -811,6 +811,24 @@ 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 cf871a81f4fd..bc5095b734f5 100644
+--- a/fs/dcache.c
++++ b/fs/dcache.c
+@@ -1320,7 +1320,7 @@ 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 9c6c6a3e2de5..02382fa9bd34 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 37710ca863b5..a30af3bd5ae1 100644
+--- a/fs/inode.c
++++ b/fs/inode.c
+@@ -1780,7 +1780,7 @@ 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 659a8f39c61a..128367073782 100644
+--- a/fs/namespace.c
++++ b/fs/namespace.c
+@@ -808,6 +808,12 @@ 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 5dbce4dcc1a7..3e6ba363b777 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 1373a610dc78..b7b5a0a0df6f 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 e7a633353fd2..376ddf1965aa 100644
+--- a/include/linux/fs.h
++++ b/include/linux/fs.h
+@@ -1381,6 +1381,7 @@ 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);
+@@ -2092,6 +2093,7 @@ 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);
+@@ -2613,6 +2615,7 @@ 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;
+@@ -2776,6 +2779,7 @@ 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 9fe165beb0f9..e47f7e15eeaf 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 8f882f5881e8..6b9808f09843 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 a55179fd60fc..8e21c53cf883 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 bf1c00c881e4..e0aaf34974df 100644
+--- a/kernel/locking/lockdep.c
++++ b/kernel/locking/lockdep.c
+@@ -189,7 +189,7 @@ 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;
+ 
+@@ -210,6 +210,7 @@ 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);
+-- 
+2.19.1
+

features/aufs/aufs5-kbuild.patch

+From e754a14d7e0df416fce85899ca37bbe11b2c1299 Mon Sep 17 00:00:00 2001
+From: Bruce Ashfield <bruce.ashfield@gmail.com>
+Date: Thu, 23 Sep 2021 11:06:29 -0400
+Subject: [PATCH 1/5] aufs5: kbuild
+
+Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>
+---
+ fs/Kconfig  | 1 +
+ fs/Makefile | 1 +
+ 2 files changed, 2 insertions(+)
+
+diff --git a/fs/Kconfig b/fs/Kconfig
+index 9837d341665c..42180a2de558 100644
+--- a/fs/Kconfig
++++ b/fs/Kconfig
+@@ -313,6 +313,7 @@ source "fs/sysv/Kconfig"
+ source "fs/ufs/Kconfig"
+ source "fs/erofs/Kconfig"
+ source "fs/vboxsf/Kconfig"
++source "fs/aufs/Kconfig"
+ 
+ endif # MISC_FILESYSTEMS
+ 
+diff --git a/fs/Makefile b/fs/Makefile
+index 10d100874723..5af561c65737 100644
+--- a/fs/Makefile
++++ b/fs/Makefile
+@@ -139,3 +139,4 @@ obj-$(CONFIG_EROFS_FS)		+= erofs/
+ obj-$(CONFIG_VBOXSF_FS)		+= vboxsf/
+ obj-$(CONFIG_ZONEFS_FS)		+= zonefs/
+ obj-$(CONFIG_YAFFS_FS)		+= yaffs2/
++obj-$(CONFIG_AUFS_FS)           += aufs/
+-- 
+2.19.1
+

features/aufs/aufs5-mmap.patch

+From bd9c14a496e3f9f106f4c3475e31c3748c33d639 Mon Sep 17 00:00:00 2001
+From: Bruce Ashfield <bruce.ashfield@gmail.com>
+Date: Thu, 23 Sep 2021 11:08:04 -0400
+Subject: [PATCH 3/5] aufs5: mmap
+
+Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>
+---
+ fs/proc/base.c           |  2 +-
+ fs/proc/nommu.c          |  5 ++-
+ fs/proc/task_mmu.c       |  7 +++-
+ fs/proc/task_nommu.c     |  5 ++-
+ include/linux/mm.h       | 22 ++++++++++
+ include/linux/mm_types.h |  2 +
+ kernel/fork.c            |  2 +-
+ mm/Makefile              |  2 +-
+ mm/filemap.c             |  2 +-
+ mm/mmap.c                | 33 +++++++++++----
+ mm/nommu.c               | 10 ++---
+ mm/prfile.c              | 86 ++++++++++++++++++++++++++++++++++++++++
+ 12 files changed, 157 insertions(+), 21 deletions(-)
+ create mode 100644 mm/prfile.c
+
+diff --git a/fs/proc/base.c b/fs/proc/base.c
+index 533d5836eb9a..f5de60c5327f 100644
+--- a/fs/proc/base.c
++++ b/fs/proc/base.c
+@@ -2186,7 +2186,7 @@ static int map_files_get_link(struct dentry *dentry, struct path *path)
+ 	rc = -ENOENT;
+ 	vma = find_exact_vma(mm, vm_start, vm_end);
+ 	if (vma && vma->vm_file) {
+-		*path = vma->vm_file->f_path;
++		*path = vma_pr_or_file(vma)->f_path;
+ 		path_get(path);
+ 		rc = 0;
+ 	}
+diff --git a/fs/proc/nommu.c b/fs/proc/nommu.c
+index 13452b32e2bd..38acccfef9d4 100644
+--- a/fs/proc/nommu.c
++++ b/fs/proc/nommu.c
+@@ -40,7 +40,10 @@ static int nommu_region_show(struct seq_file *m, struct vm_region *region)
+ 	file = region->vm_file;
+ 
+ 	if (file) {
+-		struct inode *inode = file_inode(region->vm_file);
++		struct inode *inode;
++
++		file = vmr_pr_or_file(region);
++		inode = file_inode(file);
+ 		dev = inode->i_sb->s_dev;
+ 		ino = inode->i_ino;
+ 	}
+diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
+index cf25be3e0321..70af1c25ffa2 100644
+--- a/fs/proc/task_mmu.c
++++ b/fs/proc/task_mmu.c
+@@ -280,7 +280,10 @@ show_map_vma(struct seq_file *m, struct vm_area_struct *vma)
+ 	const char *name = NULL;
+ 
+ 	if (file) {
+-		struct inode *inode = file_inode(vma->vm_file);
++		struct inode *inode;
++
++		file = vma_pr_or_file(vma);
++		inode = file_inode(file);
+ 		dev = inode->i_sb->s_dev;
+ 		ino = inode->i_ino;
+ 		pgoff = ((loff_t)vma->vm_pgoff) << PAGE_SHIFT;
+@@ -1865,7 +1868,7 @@ static int show_numa_map(struct seq_file *m, void *v)
+ 	struct proc_maps_private *proc_priv = &numa_priv->proc_maps;
+ 	struct vm_area_struct *vma = v;
+ 	struct numa_maps *md = &numa_priv->md;
+-	struct file *file = vma->vm_file;
++	struct file *file = vma_pr_or_file(vma);
+ 	struct mm_struct *mm = vma->vm_mm;
+ 	struct mempolicy *pol;
+ 	char buffer[64];
+diff --git a/fs/proc/task_nommu.c b/fs/proc/task_nommu.c
+index a6d21fc0033c..02c2de31196e 100644
+--- a/fs/proc/task_nommu.c
++++ b/fs/proc/task_nommu.c
+@@ -155,7 +155,10 @@ static int nommu_vma_show(struct seq_file *m, struct vm_area_struct *vma)
+ 	file = vma->vm_file;
+ 
+ 	if (file) {
+-		struct inode *inode = file_inode(vma->vm_file);
++		struct inode *inode;
++
++		file = vma_pr_or_file(vma);
++		inode = file_inode(file);
+ 		dev = inode->i_sb->s_dev;
+ 		ino = inode->i_ino;
+ 		pgoff = (loff_t)vma->vm_pgoff << PAGE_SHIFT;
+diff --git a/include/linux/mm.h b/include/linux/mm.h
+index 73a52aba448f..5dd42acf0707 100644
+--- a/include/linux/mm.h
++++ b/include/linux/mm.h
+@@ -1806,6 +1806,28 @@ static inline void unmap_shared_mapping_range(struct address_space *mapping,
+ 	unmap_mapping_range(mapping, holebegin, holelen, 0);
+ }
+ 
++extern void vma_do_file_update_time(struct vm_area_struct *, const char[], int);
++extern struct file *vma_do_pr_or_file(struct vm_area_struct *, const char[],
++				      int);
++extern void vma_do_get_file(struct vm_area_struct *, const char[], int);
++extern void vma_do_fput(struct vm_area_struct *, const char[], int);
++
++#define vma_file_update_time(vma)	vma_do_file_update_time(vma, __func__, \
++								__LINE__)
++#define vma_pr_or_file(vma)		vma_do_pr_or_file(vma, __func__, \
++							  __LINE__)
++#define vma_get_file(vma)		vma_do_get_file(vma, __func__, __LINE__)
++#define vma_fput(vma)			vma_do_fput(vma, __func__, __LINE__)
++
++#ifndef CONFIG_MMU
++extern struct file *vmr_do_pr_or_file(struct vm_region *, const char[], int);
++extern void vmr_do_fput(struct vm_region *, const char[], int);
++
++#define vmr_pr_or_file(region)		vmr_do_pr_or_file(region, __func__, \
++							  __LINE__)
++#define vmr_fput(region)		vmr_do_fput(region, __func__, __LINE__)
++#endif /* !CONFIG_MMU */
++
+ extern int access_process_vm(struct task_struct *tsk, unsigned long addr,
+ 		void *buf, int len, unsigned int gup_flags);
+ extern int access_remote_vm(struct mm_struct *mm, unsigned long addr,
+diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
+index 7f8ee09c711f..3a9a798a4ae1 100644
+--- a/include/linux/mm_types.h
++++ b/include/linux/mm_types.h
+@@ -294,6 +294,7 @@ struct vm_region {
+ 	unsigned long	vm_top;		/* region allocated to here */
+ 	unsigned long	vm_pgoff;	/* the offset in vm_file corresponding to vm_start */
+ 	struct file	*vm_file;	/* the backing file or NULL */
++	struct file	*vm_prfile;	/* the virtual backing file or NULL */
+ 
+ 	int		vm_usage;	/* region usage count (access under nommu_region_sem) */
+ 	bool		vm_icache_flushed : 1; /* true if the icache has been flushed for
+@@ -373,6 +374,7 @@ struct vm_area_struct {
+ 	unsigned long vm_pgoff;		/* Offset (within vm_file) in PAGE_SIZE
+ 					   units */
+ 	struct file * vm_file;		/* File we map to (can be NULL). */
++	struct file *vm_prfile;		/* shadow of vm_file */
+ 	void * vm_private_data;		/* was vm_pte (shared mem) */
+ 
+ #ifdef CONFIG_SWAP
+diff --git a/kernel/fork.c b/kernel/fork.c
+index 38681ad44c76..95de8e984319 100644
+--- a/kernel/fork.c
++++ b/kernel/fork.c
+@@ -573,7 +573,7 @@ static __latent_entropy int dup_mmap(struct mm_struct *mm,
+ 		if (file) {
+ 			struct address_space *mapping = file->f_mapping;
+ 
+-			get_file(file);
++			vma_get_file(tmp);
+ 			i_mmap_lock_write(mapping);
+ 			if (tmp->vm_flags & VM_SHARED)
+ 				mapping_allow_writable(mapping);
+diff --git a/mm/Makefile b/mm/Makefile
+index fc60a40ce954..c715b0138237 100644
+--- a/mm/Makefile
++++ b/mm/Makefile
+@@ -52,7 +52,7 @@ obj-y			:= filemap.o mempool.o oom_kill.o fadvise.o \
+ 			   mm_init.o percpu.o slab_common.o \
+ 			   compaction.o vmacache.o \
+ 			   interval_tree.o list_lru.o workingset.o \
+-			   debug.o gup.o mmap_lock.o $(mmu-y)
++			   prfile.o debug.o gup.o mmap_lock.o $(mmu-y)
+ 
+ # Give 'page_alloc' its own module-parameter namespace
+ page-alloc-y := page_alloc.o
+diff --git a/mm/filemap.c b/mm/filemap.c
+index dae481293b5d..52bf3bf87b75 100644
+--- a/mm/filemap.c
++++ b/mm/filemap.c
+@@ -3350,7 +3350,7 @@ vm_fault_t filemap_page_mkwrite(struct vm_fault *vmf)
+ 	vm_fault_t ret = VM_FAULT_LOCKED;
+ 
+ 	sb_start_pagefault(mapping->host->i_sb);
+-	file_update_time(vmf->vma->vm_file);
++	vma_file_update_time(vmf->vma);
+ 	lock_page(page);
+ 	if (page->mapping != mapping) {
+ 		unlock_page(page);
+diff --git a/mm/mmap.c b/mm/mmap.c
+index 88dcc5c25225..6c276614ca96 100644
+--- a/mm/mmap.c
++++ b/mm/mmap.c
+@@ -183,7 +183,7 @@ static struct vm_area_struct *remove_vma(struct vm_area_struct *vma)
+ 	if (vma->vm_ops && vma->vm_ops->close)
+ 		vma->vm_ops->close(vma);
+ 	if (vma->vm_file)
+-		fput(vma->vm_file);
++		vma_fput(vma);
+ 	mpol_put(vma_policy(vma));
+ 	vm_area_free(vma);
+ 	return next;
+@@ -952,7 +952,7 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start,
+ 	if (remove_next) {
+ 		if (file) {
+ 			uprobe_munmap(next, next->vm_start, next->vm_end);
+-			fput(file);
++			vma_fput(vma);
+ 		}
+ 		if (next->anon_vma)
+ 			anon_vma_merge(vma, next);
+@@ -1873,7 +1873,7 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
+ 	return addr;
+ 
+ unmap_and_free_vma:
+-	fput(vma->vm_file);
++	vma_fput(vma);
+ 	vma->vm_file = NULL;
+ 
+ 	/* Undo any partial mapping done by a device driver. */
+@@ -2731,7 +2731,7 @@ int __split_vma(struct mm_struct *mm, struct vm_area_struct *vma,
+ 		goto out_free_mpol;
+ 
+ 	if (new->vm_file)
+-		get_file(new->vm_file);
++		vma_get_file(new);
+ 
+ 	if (new->vm_ops && new->vm_ops->open)
+ 		new->vm_ops->open(new);
+@@ -2750,7 +2750,7 @@ int __split_vma(struct mm_struct *mm, struct vm_area_struct *vma,
+ 	if (new->vm_ops && new->vm_ops->close)
+ 		new->vm_ops->close(new);
+ 	if (new->vm_file)
+-		fput(new->vm_file);
++		vma_fput(new);
+ 	unlink_anon_vmas(new);
+  out_free_mpol:
+ 	mpol_put(vma_policy(new));
+@@ -2945,7 +2945,7 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
+ 	struct vm_area_struct *vma;
+ 	unsigned long populate = 0;
+ 	unsigned long ret = -EINVAL;
+-	struct file *file;
++	struct file *file, *prfile;
+ 
+ 	pr_warn_once("%s (%d) uses deprecated remap_file_pages() syscall. See Documentation/vm/remap_file_pages.rst.\n",
+ 		     current->comm, current->pid);
+@@ -3001,10 +3001,27 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
+ 	if (vma->vm_flags & VM_LOCKED)
+ 		flags |= MAP_LOCKED;
+ 
+-	file = get_file(vma->vm_file);
++	vma_get_file(vma);
++	file = vma->vm_file;
++	prfile = vma->vm_prfile;
+ 	ret = do_mmap(vma->vm_file, start, size,
+ 			prot, flags, pgoff, &populate, NULL);
++	if (!IS_ERR_VALUE(ret) && file && prfile) {
++		struct vm_area_struct *new_vma;
++
++		new_vma = find_vma(mm, ret);
++		if (!new_vma->vm_prfile)
++			new_vma->vm_prfile = prfile;
++		if (new_vma != vma)
++			get_file(prfile);
++	}
++	/*
++	 * two fput()s instead of vma_fput(vma),
++	 * coz vma may not be available anymore.
++	 */
+ 	fput(file);
++	if (prfile)
++		fput(prfile);
+ out:
+ 	mmap_write_unlock(mm);
+ 	if (populate)
+@@ -3285,7 +3302,7 @@ struct vm_area_struct *copy_vma(struct vm_area_struct **vmap,
+ 		if (anon_vma_clone(new_vma, vma))
+ 			goto out_free_mempol;
+ 		if (new_vma->vm_file)
+-			get_file(new_vma->vm_file);
++			vma_get_file(new_vma);
+ 		if (new_vma->vm_ops && new_vma->vm_ops->open)
+ 			new_vma->vm_ops->open(new_vma);
+ 		vma_link(mm, new_vma, prev, rb_link, rb_parent);
+diff --git a/mm/nommu.c b/mm/nommu.c
+index 02d2427b8f9e..a7419302ab4e 100644
+--- a/mm/nommu.c
++++ b/mm/nommu.c
+@@ -523,7 +523,7 @@ static void __put_nommu_region(struct vm_region *region)
+ 		up_write(&nommu_region_sem);
+ 
+ 		if (region->vm_file)
+-			fput(region->vm_file);
++			vmr_fput(region);
+ 
+ 		/* IO memory and memory shared directly out of the pagecache
+ 		 * from ramfs/tmpfs mustn't be released here */
+@@ -655,7 +655,7 @@ static void delete_vma(struct mm_struct *mm, struct vm_area_struct *vma)
+ 	if (vma->vm_ops && vma->vm_ops->close)
+ 		vma->vm_ops->close(vma);
+ 	if (vma->vm_file)
+-		fput(vma->vm_file);
++		vma_fput(vma);
+ 	put_nommu_region(vma->vm_region);
+ 	vm_area_free(vma);
+ }
+@@ -1175,7 +1175,7 @@ unsigned long do_mmap(struct file *file,
+ 					goto error_just_free;
+ 				}
+ 			}
+-			fput(region->vm_file);
++			vmr_fput(region);
+ 			kmem_cache_free(vm_region_jar, region);
+ 			region = pregion;
+ 			result = start;
+@@ -1252,10 +1252,10 @@ unsigned long do_mmap(struct file *file,
+ 	up_write(&nommu_region_sem);
+ error:
+ 	if (region->vm_file)
+-		fput(region->vm_file);
++		vmr_fput(region);
+ 	kmem_cache_free(vm_region_jar, region);
+ 	if (vma->vm_file)
+-		fput(vma->vm_file);
++		vma_fput(vma);
+ 	vm_area_free(vma);
+ 	return ret;
+ 
+diff --git a/mm/prfile.c b/mm/prfile.c
+new file mode 100644
+index 000000000000..511543ab1b41
+--- /dev/null
++++ b/mm/prfile.c
+@@ -0,0 +1,86 @@
++// SPDX-License-Identifier: GPL-2.0
++/*
++ * Mainly for aufs which mmap(2) different file and wants to print different
++ * path in /proc/PID/maps.
++ * Call these functions via macros defined in linux/mm.h.
++ *
++ * See Documentation/filesystems/aufs/design/06mmap.txt
++ *
++ * Copyright (c) 2014-2021 Junjro R. Okajima
++ * Copyright (c) 2014 Ian Campbell
++ */
++
++#include <linux/mm.h>
++#include <linux/file.h>
++#include <linux/fs.h>
++
++/* #define PRFILE_TRACE */
++static inline void prfile_trace(struct file *f, struct file *pr,
++			      const char func[], int line, const char func2[])
++{
++#ifdef PRFILE_TRACE
++	if (pr)
++		pr_info("%s:%d: %s, %pD2\n", func, line, func2, f);
++#endif
++}
++
++void vma_do_file_update_time(struct vm_area_struct *vma, const char func[],
++			     int line)
++{
++	struct file *f = vma->vm_file, *pr = vma->vm_prfile;
++
++	prfile_trace(f, pr, func, line, __func__);
++	file_update_time(f);
++	if (f && pr)
++		file_update_time(pr);
++}
++
++struct file *vma_do_pr_or_file(struct vm_area_struct *vma, const char func[],
++			       int line)
++{
++	struct file *f = vma->vm_file, *pr = vma->vm_prfile;
++
++	prfile_trace(f, pr, func, line, __func__);
++	return (f && pr) ? pr : f;
++}
++
++void vma_do_get_file(struct vm_area_struct *vma, const char func[], int line)
++{
++	struct file *f = vma->vm_file, *pr = vma->vm_prfile;
++
++	prfile_trace(f, pr, func, line, __func__);
++	get_file(f);
++	if (f && pr)
++		get_file(pr);
++}
++
++void vma_do_fput(struct vm_area_struct *vma, const char func[], int line)
++{
++	struct file *f = vma->vm_file, *pr = vma->vm_prfile;
++
++	prfile_trace(f, pr, func, line, __func__);
++	fput(f);
++	if (f && pr)
++		fput(pr);
++}
++
++#ifndef CONFIG_MMU
++struct file *vmr_do_pr_or_file(struct vm_region *region, const char func[],
++			       int line)
++{
++	struct file *f = region->vm_file, *pr = region->vm_prfile;
++
++	prfile_trace(f, pr, func, line, __func__);
++	return (f && pr) ? pr : f;
++}
++
++void vmr_do_fput(struct vm_region *region, const char func[], int line)
++{
++	struct file *f = region->vm_file, *pr = region->vm_prfile;
++
++	prfile_trace(f, pr, func, line, __func__);
++	fput(f);
++	if (f && pr)
++		fput(pr);
++}
++#endif /* !CONFIG_MMU */
+-- 
+2.19.1
+

features/aufs/aufs5-standalone.patch

+From b6b99d4a3e7564a1a5c37fe60dea1286b7a4742a Mon Sep 17 00:00:00 2001
+From: Bruce Ashfield <bruce.ashfield@gmail.com>
+Date: Thu, 23 Sep 2021 11:08:37 -0400
+Subject: [PATCH 4/5] aufs5: standalone
+
+Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>
+---
+ fs/dcache.c              | 2 ++
+ fs/exec.c                | 1 +
+ fs/fcntl.c               | 1 +
+ fs/file_table.c          | 2 ++
+ fs/inode.c               | 1 +
+ fs/namespace.c           | 3 +++
+ fs/notify/group.c        | 1 +
+ fs/open.c                | 1 +
+ fs/read_write.c          | 2 ++
+ fs/splice.c              | 2 ++
+ fs/sync.c                | 1 +
+ fs/xattr.c               | 1 +
+ kernel/locking/lockdep.c | 1 +
+ kernel/task_work.c       | 1 +
+ security/security.c      | 8 ++++++++
+ 15 files changed, 28 insertions(+)
+
+diff --git a/fs/dcache.c b/fs/dcache.c
+index bc5095b734f5..9508bd57a3bc 100644
+--- a/fs/dcache.c
++++ b/fs/dcache.c
+@@ -1425,6 +1425,7 @@ void d_walk(struct dentry *parent, void *data,
+ 	seq = 1;
+ 	goto again;
+ }
++EXPORT_SYMBOL_GPL(d_walk);
+ 
+ struct check_mount {
+ 	struct vfsmount *mnt;
+@@ -2970,6 +2971,7 @@ void d_exchange(struct dentry *dentry1, struct dentry *dentry2)
+ 
+ 	write_sequnlock(&rename_lock);
+ }
++EXPORT_SYMBOL_GPL(d_exchange);
+ 
+ /**
+  * d_ancestor - search for an ancestor
+diff --git a/fs/exec.c b/fs/exec.c
+index a098c133d8d7..7b6a249fd477 100644
+--- a/fs/exec.c
++++ b/fs/exec.c
+@@ -111,6 +111,7 @@ bool path_noexec(const struct path *path)
+ 	return (path->mnt->mnt_flags & MNT_NOEXEC) ||
+ 	       (path->mnt->mnt_sb->s_iflags & SB_I_NOEXEC);
+ }
++EXPORT_SYMBOL_GPL(path_noexec);
+ 
+ #ifdef CONFIG_USELIB
+ /*
+diff --git a/fs/fcntl.c b/fs/fcntl.c
+index 02382fa9bd34..3418c60b9014 100644
+--- a/fs/fcntl.c
++++ b/fs/fcntl.c
+@@ -86,6 +86,7 @@ int setfl(int fd, struct file *filp, unsigned long arg)
+  out:
+ 	return error;
+ }
++EXPORT_SYMBOL_GPL(setfl);
+ 
+ static void f_modown(struct file *filp, struct pid *pid, enum pid_type type,
+                      int force)
+diff --git a/fs/file_table.c b/fs/file_table.c
+index 45437f8e1003..786af52904fc 100644
+--- a/fs/file_table.c
++++ b/fs/file_table.c
+@@ -161,6 +161,7 @@ struct file *alloc_empty_file(int flags, const struct cred *cred)
+ 	}
+ 	return ERR_PTR(-ENFILE);
+ }
++EXPORT_SYMBOL_GPL(alloc_empty_file);
+ 
+ /*
+  * Variant of alloc_empty_file() that doesn't check and modify nr_files.
+@@ -375,6 +376,7 @@ void __fput_sync(struct file *file)
+ }
+ 
+ EXPORT_SYMBOL(fput);
++EXPORT_SYMBOL_GPL(__fput_sync);
+ 
+ void __init files_init(void)
+ {
+diff --git a/fs/inode.c b/fs/inode.c
+index a30af3bd5ae1..3b627be82eb8 100644
+--- a/fs/inode.c
++++ b/fs/inode.c
+@@ -1786,6 +1786,7 @@ int update_time(struct inode *inode, struct timespec64 *time, int flags)
+ 		return inode->i_op->update_time(inode, time, flags);
+ 	return generic_update_time(inode, time, flags);
+ }
++EXPORT_SYMBOL_GPL(update_time);
+ 
+ /**
+  *	atime_needs_update	-	update the access time
+diff --git a/fs/namespace.c b/fs/namespace.c
+index 128367073782..db9936562011 100644
+--- a/fs/namespace.c
++++ b/fs/namespace.c
+@@ -439,6 +439,7 @@ void __mnt_drop_write(struct vfsmount *mnt)
+ 	mnt_dec_writers(real_mount(mnt));
+ 	preempt_enable();
+ }
++EXPORT_SYMBOL_GPL(__mnt_drop_write);
+ 
+ /**
+  * mnt_drop_write - give up write access to a mount
+@@ -813,6 +814,7 @@ int is_current_mnt_ns(struct vfsmount *mnt)
+ {
+ 	return check_mnt(real_mount(mnt));
+ }
++EXPORT_SYMBOL_GPL(is_current_mnt_ns);
+ 
+ /*
+  * vfsmount lock must be held for write
+@@ -2011,6 +2013,7 @@ int iterate_mounts(int (*f)(struct vfsmount *, void *), void *arg,
+ 	}
+ 	return 0;
+ }
++EXPORT_SYMBOL_GPL(iterate_mounts);
+ 
+ static void lock_mnt_tree(struct mount *mnt)
+ {
+diff --git a/fs/notify/group.c b/fs/notify/group.c
+index fb89c351295d..460ad19c2570 100644
+--- a/fs/notify/group.c
++++ b/fs/notify/group.c
+@@ -100,6 +100,7 @@ void fsnotify_get_group(struct fsnotify_group *group)
+ {
+ 	refcount_inc(&group->refcnt);
+ }
++EXPORT_SYMBOL_GPL(fsnotify_get_group);
+ 
+ /*
+  * Drop a reference to a group.  Free it if it's through.
+diff --git a/fs/open.c b/fs/open.c
+index daa324606a41..0d8bb2f1922a 100644
+--- a/fs/open.c
++++ b/fs/open.c
+@@ -65,6 +65,7 @@ int do_truncate(struct user_namespace *mnt_userns, struct dentry *dentry,
+ 	inode_unlock(dentry->d_inode);
+ 	return ret;
+ }
++EXPORT_SYMBOL_GPL(do_truncate);
+ 
+ long vfs_truncate(const struct path *path, loff_t length)
+ {
+diff --git a/fs/read_write.c b/fs/read_write.c
+index af057c57bdc6..76017f8331fb 100644
+--- a/fs/read_write.c
++++ b/fs/read_write.c
+@@ -492,6 +492,7 @@ ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos)
+ 	inc_syscr(current);
+ 	return ret;
+ }
++EXPORT_SYMBOL_GPL(vfs_read);
+ 
+ static ssize_t new_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos)
+ {
+@@ -602,6 +603,7 @@ ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_
+ 	file_end_write(file);
+ 	return ret;
+ }
++EXPORT_SYMBOL_GPL(vfs_write);
+ 
+ /* file_ppos returns &file->f_pos or NULL if file is stream */
+ static inline loff_t *file_ppos(struct file *file)
+diff --git a/fs/splice.c b/fs/splice.c
+index 3e6ba363b777..7c1be373eb7c 100644
+--- a/fs/splice.c
++++ b/fs/splice.c
+@@ -766,6 +766,7 @@ long do_splice_from(struct pipe_inode_info *pipe, struct file *out,
+ 		return warn_unsupported(out, "write");
+ 	return out->f_op->splice_write(pipe, out, ppos, len, flags);
+ }
++EXPORT_SYMBOL_GPL(do_splice_from);
+ 
+ /*
+  * Attempt to initiate a splice from a file to a pipe.
+@@ -795,6 +796,7 @@ long do_splice_to(struct file *in, loff_t *ppos,
+ 		return warn_unsupported(in, "read");
+ 	return in->f_op->splice_read(in, ppos, pipe, len, flags);
+ }
++EXPORT_SYMBOL_GPL(do_splice_to);
+ 
+ /**
+  * splice_direct_to_actor - splices data directly between two non-pipes
+diff --git a/fs/sync.c b/fs/sync.c
+index b7b5a0a0df6f..fa5c7fba7f1b 100644
+--- a/fs/sync.c
++++ b/fs/sync.c
+@@ -39,6 +39,7 @@ int __sync_filesystem(struct super_block *sb, int wait)
+ 		sb->s_op->sync_fs(sb, wait);
+ 	return __sync_blockdev(sb->s_bdev, wait);
+ }
++EXPORT_SYMBOL_GPL(__sync_filesystem);
+ 
+ /*
+  * Write out and wait upon all dirty data associated with this
+diff --git a/fs/xattr.c b/fs/xattr.c
+index 5c8c5175b385..ff7e9ff774b7 100644
+--- a/fs/xattr.c
++++ b/fs/xattr.c
+@@ -384,6 +384,7 @@ vfs_getxattr_alloc(struct user_namespace *mnt_userns, struct dentry *dentry,
+ 	*xattr_value = value;
+ 	return error;
+ }
++EXPORT_SYMBOL_GPL(vfs_getxattr_alloc);
+ 
+ ssize_t
+ __vfs_getxattr(struct dentry *dentry, struct inode *inode, const char *name,
+diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
+index e0aaf34974df..d7b737731d4e 100644
+--- a/kernel/locking/lockdep.c
++++ b/kernel/locking/lockdep.c
+@@ -210,6 +210,7 @@ inline struct lock_class *lockdep_hlock_class(struct held_lock *hlock)
+ 	 */
+ 	return lock_classes + class_idx;
+ }
++EXPORT_SYMBOL_GPL(lockdep_hlock_class);
+ #define hlock_class(hlock) lockdep_hlock_class(hlock)
+ 
+ #ifdef CONFIG_LOCK_STAT
+diff --git a/kernel/task_work.c b/kernel/task_work.c
+index 1698fbe6f0e1..081b05acadf8 100644
+--- a/kernel/task_work.c
++++ b/kernel/task_work.c
+@@ -167,3 +167,4 @@ void task_work_run(void)
+ 		} while (work);
+ 	}
+ }
++EXPORT_SYMBOL_GPL(task_work_run);
+diff --git a/security/security.c b/security/security.c
+index 9ffa9e9c5c55..83b533a3fb8e 100644
+--- a/security/security.c
++++ b/security/security.c
+@@ -1147,6 +1147,7 @@ int security_path_rmdir(const struct path *dir, struct dentry *dentry)
+ 		return 0;
+ 	return call_int_hook(path_rmdir, 0, dir, dentry);
+ }
++EXPORT_SYMBOL_GPL(security_path_rmdir);
+ 
+ int security_path_unlink(const struct path *dir, struct dentry *dentry)
+ {
+@@ -1163,6 +1164,7 @@ int security_path_symlink(const struct path *dir, struct dentry *dentry,
+ 		return 0;
+ 	return call_int_hook(path_symlink, 0, dir, dentry, old_name);
+ }
++EXPORT_SYMBOL_GPL(security_path_symlink);
+ 
+ int security_path_link(struct dentry *old_dentry, const struct path *new_dir,
+ 		       struct dentry *new_dentry)
+@@ -1171,6 +1173,7 @@ int security_path_link(struct dentry *old_dentry, const struct path *new_dir,
+ 		return 0;
+ 	return call_int_hook(path_link, 0, old_dentry, new_dir, new_dentry);
+ }
++EXPORT_SYMBOL_GPL(security_path_link);
+ 
+ int security_path_rename(const struct path *old_dir, struct dentry *old_dentry,
+ 			 const struct path *new_dir, struct dentry *new_dentry,
+@@ -1198,6 +1201,7 @@ int security_path_truncate(const struct path *path)
+ 		return 0;
+ 	return call_int_hook(path_truncate, 0, path);
+ }
++EXPORT_SYMBOL_GPL(security_path_truncate);
+ 
+ int security_path_chmod(const struct path *path, umode_t mode)
+ {
+@@ -1205,6 +1209,7 @@ int security_path_chmod(const struct path *path, umode_t mode)
+ 		return 0;
+ 	return call_int_hook(path_chmod, 0, path, mode);
+ }
++EXPORT_SYMBOL_GPL(security_path_chmod);
+ 
+ int security_path_chown(const struct path *path, kuid_t uid, kgid_t gid)
+ {
+@@ -1212,6 +1217,7 @@ int security_path_chown(const struct path *path, kuid_t uid, kgid_t gid)
+ 		return 0;
+ 	return call_int_hook(path_chown, 0, path, uid, gid);
+ }
++EXPORT_SYMBOL_GPL(security_path_chown);
+ 
+ int security_path_chroot(const struct path *path)
+ {
+@@ -1312,6 +1318,7 @@ int security_inode_permission(struct inode *inode, int mask)
+ 		return 0;
+ 	return call_int_hook(inode_permission, 0, inode, mask);
+ }
++EXPORT_SYMBOL_GPL(security_inode_permission);
+ 
+ int security_inode_setattr(struct dentry *dentry, struct iattr *attr)
+ {
+@@ -1509,6 +1516,7 @@ int security_file_permission(struct file *file, int mask)
+ 
+ 	return fsnotify_perm(file, mask);
+ }
++EXPORT_SYMBOL_GPL(security_file_permission);
+ 
+ int security_file_alloc(struct file *file)
+ {
+-- 
+2.19.1
+