fs/9p: Move writeback fid to v9fs_inode

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
diff --git a/fs/9p/v9fs.h b/fs/9p/v9fs.h
index ce59d15..71cab8e 100644
--- a/fs/9p/v9fs.h
+++ b/fs/9p/v9fs.h
@@ -122,6 +122,7 @@
 	struct fscache_cookie *fscache;
 	struct p9_qid *fscache_key;
 #endif
+	struct p9_fid *writeback_fid;
 	struct inode vfs_inode;
 };
 
diff --git a/fs/9p/vfs_addr.c b/fs/9p/vfs_addr.c
index 566684c..ee45552 100644
--- a/fs/9p/vfs_addr.c
+++ b/fs/9p/vfs_addr.c
@@ -163,8 +163,10 @@
 	int retval, len;
 	loff_t offset, size;
 	mm_segment_t old_fs;
+	struct v9fs_inode *v9inode;
 	struct inode *inode = page->mapping->host;
 
+	v9inode = V9FS_I(inode);
 	size = i_size_read(inode);
 	if (page->index == size >> PAGE_CACHE_SHIFT)
 		len = size & ~PAGE_CACHE_MASK;
@@ -178,11 +180,11 @@
 
 	old_fs = get_fs();
 	set_fs(get_ds());
-	/* We should have i_private always set */
-	BUG_ON(!inode->i_private);
+	/* We should have writeback_fid always set */
+	BUG_ON(!v9inode->writeback_fid);
 
 	retval = v9fs_file_write_internal(inode,
-					  (struct p9_fid *)inode->i_private,
+					  v9inode->writeback_fid,
 					  (__force const char __user *)buffer,
 					  len, &offset, 0);
 	if (retval > 0)
@@ -274,23 +276,25 @@
 {
 	int retval = 0;
 	struct page *page;
+	struct v9fs_inode *v9inode;
 	pgoff_t index = pos >> PAGE_CACHE_SHIFT;
 	struct inode *inode = mapping->host;
 
+	v9inode = V9FS_I(inode);
 start:
 	page = grab_cache_page_write_begin(mapping, index, flags);
 	if (!page) {
 		retval = -ENOMEM;
 		goto out;
 	}
-	BUG_ON(!inode->i_private);
+	BUG_ON(!v9inode->writeback_fid);
 	if (PageUptodate(page))
 		goto out;
 
 	if (len == PAGE_CACHE_SIZE)
 		goto out;
 
-	retval = v9fs_fid_readpage(inode->i_private, page);
+	retval = v9fs_fid_readpage(v9inode->writeback_fid, page);
 	page_cache_release(page);
 	if (!retval)
 		goto start;
diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
index f7b571d..98c4307 100644
--- a/fs/9p/vfs_file.c
+++ b/fs/9p/vfs_file.c
@@ -56,11 +56,13 @@
 int v9fs_file_open(struct inode *inode, struct file *file)
 {
 	int err;
+	struct v9fs_inode *v9inode;
 	struct v9fs_session_info *v9ses;
 	struct p9_fid *fid;
 	int omode;
 
 	P9_DPRINTK(P9_DEBUG_VFS, "inode: %p file: %p\n", inode, file);
+	v9inode = V9FS_I(inode);
 	v9ses = v9fs_inode2v9ses(inode);
 	if (v9fs_proto_dotl(v9ses))
 		omode = file->f_flags;
@@ -88,9 +90,9 @@
 	}
 
 	file->private_data = fid;
-	if (v9ses->cache && !inode->i_private) {
+	if (v9ses->cache && !v9inode->writeback_fid) {
 		/*
-		 * clone a fid and add it to inode->i_private
+		 * clone a fid and add it to writeback_fid
 		 * we do it during open time instead of
 		 * page dirty time via write_begin/page_mkwrite
 		 * because we want write after unlink usecase
@@ -101,7 +103,7 @@
 			err = PTR_ERR(fid);
 			goto out_error;
 		}
-		inode->i_private = (void *) fid;
+		v9inode->writeback_fid = (void *) fid;
 	}
 #ifdef CONFIG_9P_FSCACHE
 	if (v9ses->cache)
@@ -550,6 +552,7 @@
 static int
 v9fs_vm_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
+	struct v9fs_inode *v9inode;
 	struct page *page = vmf->page;
 	struct file *filp = vma->vm_file;
 	struct inode *inode = filp->f_path.dentry->d_inode;
@@ -558,9 +561,10 @@
 	P9_DPRINTK(P9_DEBUG_VFS, "page %p fid %lx\n",
 		   page, (unsigned long)filp->private_data);
 
+	v9inode = V9FS_I(inode);
 	/* make sure the cache has finished storing the page */
 	v9fs_fscache_wait_on_page_write(inode, page);
-	BUG_ON(!inode->i_private);
+	BUG_ON(!v9inode->writeback_fid);
 	lock_page(page);
 	if (page->mapping != inode->i_mapping)
 		goto out_unlock;
diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index 411c70a..fdc086d 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -219,6 +219,7 @@
 	v9inode->fscache_key = NULL;
 	spin_lock_init(&v9inode->fscache_lock);
 #endif
+	v9inode->writeback_fid = NULL;
 	return &v9inode->vfs_inode;
 }
 
@@ -414,6 +415,8 @@
  */
 void v9fs_evict_inode(struct inode *inode)
 {
+	struct v9fs_inode *v9inode = V9FS_I(inode);
+
 	truncate_inode_pages(inode->i_mapping, 0);
 	end_writeback(inode);
 	filemap_fdatawrite(inode->i_mapping);
@@ -421,10 +424,10 @@
 #ifdef CONFIG_9P_FSCACHE
 	v9fs_cache_inode_put_cookie(inode);
 #endif
-	/* clunk the fid stashed in inode->i_private */
-	if (inode->i_private) {
-		p9_client_clunk((struct p9_fid *)inode->i_private);
-		inode->i_private = NULL;
+	/* clunk the fid stashed in writeback_fid */
+	if (v9inode->writeback_fid) {
+		p9_client_clunk(v9inode->writeback_fid);
+		v9inode->writeback_fid = NULL;
 	}
 }
 
@@ -607,9 +610,10 @@
 	int err;
 	u32 perm;
 	int flags;
+	struct file *filp;
+	struct v9fs_inode *v9inode;
 	struct v9fs_session_info *v9ses;
 	struct p9_fid *fid, *inode_fid;
-	struct file *filp;
 
 	err = 0;
 	fid = NULL;
@@ -631,9 +635,10 @@
 
 	/* if we are opening a file, assign the open fid to the file */
 	if (nd && nd->flags & LOOKUP_OPEN) {
-		if (v9ses->cache && !dentry->d_inode->i_private) {
+		v9inode = V9FS_I(dentry->d_inode);
+		if (v9ses->cache && !v9inode->writeback_fid) {
 			/*
-			 * clone a fid and add it to inode->i_private
+			 * clone a fid and add it to writeback_fid
 			 * we do it during open time instead of
 			 * page dirty time via write_begin/page_mkwrite
 			 * because we want write after unlink usecase
@@ -644,7 +649,7 @@
 				err = PTR_ERR(inode_fid);
 				goto error;
 			}
-			dentry->d_inode->i_private = (void *) inode_fid;
+			v9inode->writeback_fid = (void *) inode_fid;
 		}
 		filp = lookup_instantiate_filp(nd, dentry, generic_file_open);
 		if (IS_ERR(filp)) {
diff --git a/fs/9p/vfs_inode_dotl.c b/fs/9p/vfs_inode_dotl.c
index 21523f2..9845941 100644
--- a/fs/9p/vfs_inode_dotl.c
+++ b/fs/9p/vfs_inode_dotl.c
@@ -159,16 +159,17 @@
 		struct nameidata *nd)
 {
 	int err = 0;
-	char *name = NULL;
 	gid_t gid;
 	int flags;
 	mode_t mode;
-	struct v9fs_session_info *v9ses;
-	struct p9_fid *fid = NULL;
-	struct p9_fid *dfid, *ofid, *inode_fid;
+	char *name = NULL;
 	struct file *filp;
 	struct p9_qid qid;
 	struct inode *inode;
+	struct p9_fid *fid = NULL;
+	struct v9fs_inode *v9inode;
+	struct p9_fid *dfid, *ofid, *inode_fid;
+	struct v9fs_session_info *v9ses;
 	struct posix_acl *pacl = NULL, *dacl = NULL;
 
 	v9ses = v9fs_inode2v9ses(dir);
@@ -241,9 +242,11 @@
 
 	/* Now set the ACL based on the default value */
 	v9fs_set_create_acl(dentry, dacl, pacl);
-	if (v9ses->cache && !inode->i_private) {
+
+	v9inode = V9FS_I(inode);
+	if (v9ses->cache && !v9inode->writeback_fid) {
 		/*
-		 * clone a fid and add it to inode->i_private
+		 * clone a fid and add it to writeback_fid
 		 * we do it during open time instead of
 		 * page dirty time via write_begin/page_mkwrite
 		 * because we want write after unlink usecase
@@ -254,7 +257,7 @@
 			err = PTR_ERR(inode_fid);
 			goto error;
 		}
-		inode->i_private = (void *) inode_fid;
+		v9inode->writeback_fid = (void *) inode_fid;
 	}
 	/* Since we are opening a file, assign the open fid to the file */
 	filp = lookup_instantiate_filp(nd, dentry, generic_file_open);