f2fs: update inode page after creation

I found a bug when testing power-off-recovery as follows.

[Bug Scenario]
1. create a file
2. fsync the file
3. reboot w/o any sync
4. try to recover the file
 - found its fsync mark
 - found its dentry mark
   : try to recover its dentry
    - get its file name
    - get its parent inode number
     : here we got zero value

The reason why we get the wrong parent inode number is that we didn't
synchronize the inode page with its newly created inode information perfectly.

Especially, previous f2fs stores fi->i_pino and writes it to the cached
node page in a wrong order, which incurs the zero-valued i_pino during the
recovery.

So, this patch modifies the creation flow to fix the synchronization order of
inode page with its inode.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

1 files changed, 45 insertions, 40 deletions

diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c
index 7db6e58..fc1dacf 100644
--- a/fs/f2fs/dir.c
+++ b/fs/f2fs/dir.c
@@ -264,15 +264,10 @@ void f2fs_set_link(struct inode *dir, struct f2fs_dir_entry *de,
 	f2fs_put_page(page, 1);
 }
 
-void init_dent_inode(const struct qstr *name, struct page *ipage)
+static void init_dent_inode(const struct qstr *name, struct page *ipage)
 {
 	struct f2fs_node *rn;
 
-	if (IS_ERR(ipage))
-		return;
-
-	wait_on_page_writeback(ipage);
-
 	/* copy name info. to this inode page */
 	rn = (struct f2fs_node *)page_address(ipage);
 	rn->i.i_namelen = cpu_to_le32(name->len);
@@ -280,14 +275,15 @@ void init_dent_inode(const struct qstr *name, struct page *ipage)
 	set_page_dirty(ipage);
 }
 
-static int make_empty_dir(struct inode *inode, struct inode *parent)
+static int make_empty_dir(struct inode *inode,
+		struct inode *parent, struct page *page)
 {
 	struct page *dentry_page;
 	struct f2fs_dentry_block *dentry_blk;
 	struct f2fs_dir_entry *de;
 	void *kaddr;
 
-	dentry_page = get_new_data_page(inode, NULL, 0, true);
+	dentry_page = get_new_data_page(inode, page, 0, true);
 	if (IS_ERR(dentry_page))
 		return PTR_ERR(dentry_page);
 
@@ -317,42 +313,47 @@ static int make_empty_dir(struct inode *inode, struct inode *parent)
 	return 0;
 }
 
-static int init_inode_metadata(struct inode *inode,
+static struct page *init_inode_metadata(struct inode *inode,
 		struct inode *dir, const struct qstr *name)
 {
+	struct page *page;
+	int err;
+
 	if (is_inode_flag_set(F2FS_I(inode), FI_NEW_INODE)) {
-		int err;
-		err = new_inode_page(inode, name);
-		if (err)
-			return err;
+		page = new_inode_page(inode, name);
+		if (IS_ERR(page))
+			return page;
 
 		if (S_ISDIR(inode->i_mode)) {
-			err = make_empty_dir(inode, dir);
-			if (err) {
-				remove_inode_page(inode);
-				return err;
-			}
+			err = make_empty_dir(inode, dir, page);
+			if (err)
+				goto error;
 		}
 
 		err = f2fs_init_acl(inode, dir);
-		if (err) {
-			remove_inode_page(inode);
-			return err;
-		}
+		if (err)
+			goto error;
+
+		wait_on_page_writeback(page);
 	} else {
-		struct page *ipage;
-		ipage = get_node_page(F2FS_SB(dir->i_sb), inode->i_ino);
-		if (IS_ERR(ipage))
-			return PTR_ERR(ipage);
-		set_cold_node(inode, ipage);
-		init_dent_inode(name, ipage);
-		f2fs_put_page(ipage, 1);
+		page = get_node_page(F2FS_SB(dir->i_sb), inode->i_ino);
+		if (IS_ERR(page))
+			return page;
+
+		wait_on_page_writeback(page);
+		set_cold_node(inode, page);
 	}
-	if (is_inode_flag_set(F2FS_I(inode), FI_INC_LINK)) {
+
+	init_dent_inode(name, page);
+
+	if (is_inode_flag_set(F2FS_I(inode), FI_INC_LINK))
 		inc_nlink(inode);
-		update_inode_page(inode);
-	}
-	return 0;
+	return page;
+
+error:
+	f2fs_put_page(page, 1);
+	remove_inode_page(inode);
+	return ERR_PTR(err);
 }
 
 static void update_parent_metadata(struct inode *dir, struct inode *inode,
@@ -423,6 +424,7 @@ int __f2fs_add_link(struct inode *dir, const struct qstr *name, struct inode *in
 	struct page *dentry_page = NULL;
 	struct f2fs_dentry_block *dentry_blk = NULL;
 	int slots = GET_DENTRY_SLOTS(namelen);
+	struct page *page;
 	int err = 0;
 	int i;
 
@@ -465,12 +467,13 @@ start:
 	++level;
 	goto start;
 add_dentry:
-	err = init_inode_metadata(inode, dir, name);
-	if (err)
-		goto fail;
-
 	wait_on_page_writeback(dentry_page);
 
+	page = init_inode_metadata(inode, dir, name);
+	if (IS_ERR(page)) {
+		err = PTR_ERR(page);
+		goto fail;
+	}
 	de = &dentry_blk->dentry[bit_pos];
 	de->hash_code = dentry_hash;
 	de->name_len = cpu_to_le16(namelen);
@@ -481,10 +484,12 @@ add_dentry:
 		test_and_set_bit_le(bit_pos + i, &dentry_blk->dentry_bitmap);
 	set_page_dirty(dentry_page);
 
-	update_parent_metadata(dir, inode, current_depth);
-
-	/* update parent inode number before releasing dentry page */
+	/* we don't need to mark_inode_dirty now */
 	F2FS_I(inode)->i_pino = dir->i_ino;
+	update_inode(inode, page);
+	f2fs_put_page(page, 1);
+
+	update_parent_metadata(dir, inode, current_depth);
 fail:
 	kunmap(dentry_page);
 	f2fs_put_page(dentry_page, 1);