aufs3.8 proc_map patch

diff --git a/fs/buffer.c b/fs/buffer.c
index 7a75c3e..b9c3f3c 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -2380,6 +2380,8 @@ int block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
 	 * fault so this update may be superfluous but who really cares...
 	 */
 	file_update_time(vma->vm_file);
+	if (vma->vm_prfile)
+		file_update_time(vma->vm_prfile);
 
 	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 b1822dd..8b29ab7 100644
--- a/fs/proc/nommu.c
+++ b/fs/proc/nommu.c
@@ -46,6 +46,10 @@ static int nommu_region_show(struct seq_file *m, struct vm_region *region)
 
 	if (file) {
 		struct inode *inode = region->vm_file->f_path.dentry->d_inode;
+		if (region->vm_prfile) {
+			file = region->vm_prfile;
+			inode = file->f_path.dentry->d_inode;
+		}
 		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 ca5ce7f..45db66f 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -272,6 +272,10 @@ show_map_vma(struct seq_file *m, struct vm_area_struct *vma, int is_pid)
 
 	if (file) {
 		struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
+		if (vma->vm_prfile) {
+			file = vma->vm_prfile;
+			inode = file->f_path.dentry->d_inode;
+		}
 		dev = inode->i_sb->s_dev;
 		ino = inode->i_ino;
 		pgoff = ((loff_t)vma->vm_pgoff) << PAGE_SHIFT;
@@ -1285,6 +1289,8 @@ static int show_numa_map(struct seq_file *m, void *v, int is_pid)
 
 	if (file) {
 		seq_printf(m, " file=");
+		if (vma->vm_prfile)
+			file = vma->vm_prfile;
 		seq_path(m, &file->f_path, "\n\t= ");
 	} else if (vma->vm_start <= mm->brk && vma->vm_end >= mm->start_brk) {
 		seq_printf(m, " heap");
diff --git a/fs/proc/task_nommu.c b/fs/proc/task_nommu.c
index 1ccfa53..c39acb5 100644
--- a/fs/proc/task_nommu.c
+++ b/fs/proc/task_nommu.c
@@ -150,6 +150,10 @@ static int nommu_vma_show(struct seq_file *m, struct vm_area_struct *vma,
 
 	if (file) {
 		struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
+		if (vma->vm_prfile) {
+			file = vma->vm_prfile;
+			inode = file->f_path.dentry->d_inode;
+		}
 		dev = inode->i_sb->s_dev;
 		ino = inode->i_ino;
 		pgoff = (loff_t)vma->vm_pgoff << PAGE_SHIFT;
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index f8f5162..25ce88d 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -212,6 +212,7 @@ 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
@@ -280,6 +281,7 @@ 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 c535f33..76da22a 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -417,6 +417,8 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
 			struct address_space *mapping = file->f_mapping;
 
 			get_file(file);
+			if (tmp->vm_prfile)
+				get_file(tmp->vm_prfile);
 			if (tmp->vm_flags & VM_DENYWRITE)
 				atomic_dec(&inode->i_writecount);
 			mutex_lock(&mapping->i_mmap_mutex);
diff --git a/mm/memory.c b/mm/memory.c
index bb1369f..105c729 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3373,6 +3373,8 @@ static int __do_fault(struct mm_struct *mm, struct vm_area_struct *vma,
 		/* file_update_time outside page_lock */
 		if (vma->vm_file && !page_mkwrite)
 			file_update_time(vma->vm_file);
+		if (vma->vm_prfile && !page_mkwrite)
+			file_update_time(vma->vm_prfile);
 	} else {
 		unlock_page(vmf.page);
 		if (anon)
diff --git a/mm/mmap.c b/mm/mmap.c
index d1e4124..1ecbb55 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -242,6 +242,8 @@ static struct vm_area_struct *remove_vma(struct vm_area_struct *vma)
 		vma->vm_ops->close(vma);
 	if (vma->vm_file)
 		fput(vma->vm_file);
+	if (vma->vm_prfile)
+		fput(vma->vm_prfile);
 	mpol_put(vma_policy(vma));
 	kmem_cache_free(vm_area_cachep, vma);
 	return next;
@@ -816,6 +818,8 @@ again:			remove_next = 1 + (end > next->vm_end);
 		if (file) {
 			uprobe_munmap(next, next->vm_start, next->vm_end);
 			fput(file);
+			if (vma->vm_prfile)
+				fput(vma->vm_prfile);
 		}
 		if (next->anon_vma)
 			anon_vma_merge(vma, next);
@@ -2344,6 +2348,8 @@ static int __split_vma(struct mm_struct * mm, struct vm_area_struct * vma,
 
 	if (new->vm_file)
 		get_file(new->vm_file);
+	if (new->vm_prfile)
+		get_file(new->vm_prfile);
 
 	if (new->vm_ops && new->vm_ops->open)
 		new->vm_ops->open(new);
@@ -2363,6 +2369,8 @@ static int __split_vma(struct mm_struct * mm, struct vm_area_struct * vma,
 		new->vm_ops->close(new);
 	if (new->vm_file)
 		fput(new->vm_file);
+	if (new->vm_prfile)
+		fput(new->vm_prfile);
 	unlink_anon_vmas(new);
  out_free_mpol:
 	mpol_put(pol);
@@ -2760,6 +2768,8 @@ struct vm_area_struct *copy_vma(struct vm_area_struct **vmap,
 				goto out_free_mempol;
 			if (new_vma->vm_file)
 				get_file(new_vma->vm_file);
+			if (new_vma->vm_prfile)
+				get_file(new_vma->vm_prfile);
 			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 79c3cac..85da8dc 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -648,6 +648,8 @@ static void __put_nommu_region(struct vm_region *region)
 
 		if (region->vm_file)
 			fput(region->vm_file);
+		if (region->vm_prfile)
+			fput(region->vm_prfile);
 
 		/* IO memory and memory shared directly out of the pagecache
 		 * from ramfs/tmpfs mustn't be released here */
@@ -806,6 +808,8 @@ static void delete_vma(struct mm_struct *mm, struct vm_area_struct *vma)
 		vma->vm_ops->close(vma);
 	if (vma->vm_file)
 		fput(vma->vm_file);
+	if (vma->vm_prfile)
+		fput(vma->vm_prfile);
 	put_nommu_region(vma->vm_region);
 	kmem_cache_free(vm_area_cachep, vma);
 }
@@ -1369,6 +1373,8 @@ unsigned long do_mmap_pgoff(struct file *file,
 				}
 			}
 			fput(region->vm_file);
+			if (region->vm_prfile)
+				fput(region->vm_prfile);
 			kmem_cache_free(vm_region_jar, region);
 			region = pregion;
 			result = start;
@@ -1445,9 +1451,13 @@ error_just_free:
 error:
 	if (region->vm_file)
 		fput(region->vm_file);
+	if (region->vm_prfile)
+		fput(region->vm_prfile);
 	kmem_cache_free(vm_region_jar, region);
 	if (vma->vm_file)
 		fput(vma->vm_file);
+	if (vma->vm_prfile)
+		fput(vma->vm_prfile);
 	kmem_cache_free(vm_area_cachep, vma);
 	kleave(" = %d", ret);
 	return ret;
