From: J. R. Okajima <hooanon05@yahoo.co.jp>
Date: Tue Apr 15 12:26:44 2014 +0900
Subject: aufs3.x-rcN mmap patch
Origin: http://sourceforge.net/p/aufs/aufs3-standalone/ci/8803c2d8d64effad56733f141431af5a2491b19f/tree/
Bug-Debian: http://bugs.debian.org/541828

Patch headers added by debian/patches/features/all/aufs3/gen-patch

aufs3.x-rcN mmap patch

diff --git a/fs/buffer.c b/fs/buffer.c
index 9ddb9fc..1059a0b 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -2448,7 +2448,7 @@ int block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
 	 * Update file times before taking page lock. We may end up failing the
 	 * fault so this update may be superfluous but who really cares...
 	 */
-	file_update_time(vma->vm_file);
+	vma_file_update_time(vma);
 
 	ret = __block_page_mkwrite(vma, vmf, get_block);
 	sb_end_pagefault(sb);
diff --git a/fs/proc/nommu.c b/fs/proc/nommu.c
index d4a3574..e44a744 100644
--- a/fs/proc/nommu.c
+++ b/fs/proc/nommu.c
@@ -45,7 +45,9 @@ 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 442177b..2fd6081d 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -265,7 +265,9 @@ show_map_vma(struct seq_file *m, struct vm_area_struct *vma, int is_pid)
 	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;
@@ -1408,6 +1410,7 @@ static int show_numa_map(struct seq_file *m, void *v, int is_pid)
 	seq_printf(m, "%08lx %s", vma->vm_start, buffer);
 
 	if (file) {
+		file = vma_pr_or_file(vma);
 		seq_printf(m, " file=");
 		seq_path(m, &file->f_path, "\n\t= ");
 	} else if (vma->vm_start <= mm->brk && vma->vm_end >= mm->start_brk) {
diff --git a/fs/proc/task_nommu.c b/fs/proc/task_nommu.c
index 678455d..ad0ce45 100644
--- a/fs/proc/task_nommu.c
+++ b/fs/proc/task_nommu.c
@@ -141,7 +141,9 @@ 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(file);
+		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 bf9811e..3c727c8 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -18,6 +18,9 @@
 #include <linux/pfn.h>
 #include <linux/bit_spinlock.h>
 #include <linux/shrinker.h>
+#include <linux/dcache.h>
+#include <linux/file.h>
+#include <linux/fs.h>
 
 struct mempolicy;
 struct anon_vma;
@@ -1171,6 +1174,87 @@ static inline int fixup_user_fault(struct task_struct *tsk,
 }
 #endif
 
+/*
+ * Mainly for aufs which mmap(2) diffrent file and wants to print different path
+ * in /proc/PID/maps.
+ */
+/* #define AUFS_DEBUG_MMAP */
+static inline void aufs_trace(struct file *f, struct file *pr,
+			      const char func[], int line, const char func2[])
+{
+#ifdef AUFS_DEBUG_MMAP
+	if (pr)
+		pr_info("%s:%d: %s, %p\n", func, line, func2,
+			f ? (char *)f->f_dentry->d_name.name : "(null)");
+#endif
+}
+
+static inline 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;
+	aufs_trace(f, pr, func, line, __func__);
+	return (f && pr) ? pr : f;
+}
+
+static inline void vmr_do_fput(struct vm_region *region,
+			       const char func[], int line)
+{
+	struct file *f = region->vm_file, *pr = region->vm_prfile;
+	aufs_trace(f, pr, func, line, __func__);
+	fput(f);
+	if (f && pr)
+		fput(pr);
+}
+
+static inline 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;
+	aufs_trace(f, pr, func, line, __func__);
+	file_update_time(f);
+	if (f && pr)
+		file_update_time(pr);
+}
+
+static inline 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;
+	aufs_trace(f, pr, func, line, __func__);
+	return (f && pr) ? pr : f;
+}
+
+static inline 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;
+	aufs_trace(f, pr, func, line, __func__);
+	get_file(f);
+	if (f && pr)
+		get_file(pr);
+}
+
+static inline void vma_do_fput(struct vm_area_struct *vma,
+			       const char func[], int line)
+{
+	struct file *f = vma->vm_file, *pr = vma->vm_prfile;
+	aufs_trace(f, pr, func, line, __func__);
+	fput(f);
+	if (f && pr)
+		fput(pr);
+}
+
+#define vmr_pr_or_file(region)		vmr_do_pr_or_file(region, __func__, \
+							  __LINE__)
+#define vmr_fput(region)		vmr_do_fput(region, __func__, __LINE__)
+#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__)
+
 extern int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write);
 extern int access_remote_vm(struct mm_struct *mm, unsigned long addr,
 		void *buf, int len, int write);
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 8967e20..a57b589 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -232,6 +232,7 @@ 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
@@ -300,6 +301,7 @@ struct vm_area_struct {
 	unsigned long vm_pgoff;		/* Offset (within vm_file) in PAGE_SIZE
 					   units, *not* PAGE_CACHE_SIZE */
 	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) */
 
 #ifndef CONFIG_MMU
diff --git a/kernel/fork.c b/kernel/fork.c
index 54a8d26..dcf08b6 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -416,7 +416,7 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
 			struct inode *inode = file_inode(file);
 			struct address_space *mapping = file->f_mapping;
 
-			get_file(file);
+			vma_get_file(tmp);
 			if (tmp->vm_flags & VM_DENYWRITE)
 				atomic_dec(&inode->i_writecount);
 			mutex_lock(&mapping->i_mmap_mutex);
diff --git a/mm/filemap.c b/mm/filemap.c
index a82fbe4..f7e38b6 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2082,7 +2082,7 @@ int filemap_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
 	int ret = VM_FAULT_LOCKED;
 
 	sb_start_pagefault(inode->i_sb);
-	file_update_time(vma->vm_file);
+	vma_file_update_time(vma);
 	lock_page(page);
 	if (page->mapping != inode->i_mapping) {
 		unlock_page(page);
diff --git a/mm/fremap.c b/mm/fremap.c
index 34feba6..d857364 100644
--- a/mm/fremap.c
+++ b/mm/fremap.c
@@ -227,7 +227,9 @@ get_write_lock:
 			/* mmap_region may free vma; grab the info now */
 			vm_flags = vma->vm_flags;
 
+			vma_get_file(vma);
 			addr = mmap_region(file, start, size, vm_flags, pgoff);
+			vma_fput(vma);
 			fput(file);
 			if (IS_ERR_VALUE(addr)) {
 				err = addr;
diff --git a/mm/madvise.c b/mm/madvise.c
index 539eeb9..5e700b1 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -327,12 +327,12 @@ static long madvise_remove(struct vm_area_struct *vma,
 	 * vma's reference to the file) can go away as soon as we drop
 	 * mmap_sem.
 	 */
-	get_file(f);
+	vma_get_file(vma);
 	up_read(&current->mm->mmap_sem);
 	error = do_fallocate(f,
 				FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
 				offset, end - start);
-	fput(f);
+	vma_fput(vma);
 	down_read(&current->mm->mmap_sem);
 	return error;
 }
diff --git a/mm/memory.c b/mm/memory.c
index d0f0bef..1293484 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2785,7 +2785,7 @@ reuse:
 			set_page_dirty_balance(dirty_page);
 			/* file_update_time outside page_lock */
 			if (vma->vm_file)
-				file_update_time(vma->vm_file);
+				vma_file_update_time(vma);
 		}
 		put_page(dirty_page);
 		if (page_mkwrite) {
diff --git a/mm/mmap.c b/mm/mmap.c
index b1202cf..40dd067 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -250,7 +250,7 @@ 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));
 	kmem_cache_free(vm_area_cachep, vma);
 	return next;
@@ -861,7 +861,7 @@ again:			remove_next = 1 + (end > next->vm_end);
 	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);
@@ -1641,8 +1641,8 @@ out:
 unmap_and_free_vma:
 	if (vm_flags & VM_DENYWRITE)
 		allow_write_access(file);
+	vma_fput(vma);
 	vma->vm_file = NULL;
-	fput(file);
 
 	/* Undo any partial mapping done by a device driver. */
 	unmap_region(mm, vma, prev, vma->vm_start, vma->vm_end);
@@ -2432,7 +2432,7 @@ static 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);
@@ -2451,7 +2451,7 @@ static 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));
@@ -2840,7 +2840,7 @@ 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/msync.c b/mm/msync.c
index 632df45..02d770e 100644
--- a/mm/msync.c
+++ b/mm/msync.c
@@ -80,10 +80,10 @@ SYSCALL_DEFINE3(msync, unsigned long, start, size_t, len, int, flags)
 		start = vma->vm_end;
 		if ((flags & MS_SYNC) && file &&
 				(vma->vm_flags & VM_SHARED)) {
-			get_file(file);
+			vma_get_file(vma);
 			up_read(&mm->mmap_sem);
 			error = vfs_fsync(file, 0);
-			fput(file);
+			vma_fput(vma);
 			if (error || start >= end)
 				goto out;
 			down_read(&mm->mmap_sem);
diff --git a/mm/nommu.c b/mm/nommu.c
index 85f8d66..9f471fa 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -655,7 +655,7 @@ 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 */
@@ -820,7 +820,7 @@ 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);
 	kmem_cache_free(vm_area_cachep, vma);
 }
@@ -1382,7 +1382,7 @@ unsigned long do_mmap_pgoff(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;
@@ -1458,10 +1458,10 @@ error_just_free:
 	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);
 	kmem_cache_free(vm_area_cachep, vma);
 	kleave(" = %d", ret);
 	return ret;
