f2fs: fix iget/iput of dir during recovery

It is possible that iput is skipped after iget during the recovery.

In recover_dentry(),
 dir = f2fs_iget();
 ...
 if (de && inode->i_ino == le32_to_cpu(de->ino))
	goto out;

In this case, this dir is not able to be added in dirty_dir_inode_list.
The actual linking is done only when set_page_dirty() is called.

So let's add this newly got inode into the list explicitly, and put it at the
end of the recovery routine.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index 6f56e57..9a77509 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -450,13 +450,30 @@
 	return -EINVAL;
 }
 
-void set_dirty_dir_page(struct inode *inode, struct page *page)
+static int __add_dirty_inode(struct inode *inode, struct dir_inode_entry *new)
 {
 	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 	struct list_head *head = &sbi->dir_inode_list;
-	struct dir_inode_entry *new;
 	struct list_head *this;
 
+	list_for_each(this, head) {
+		struct dir_inode_entry *entry;
+		entry = list_entry(this, struct dir_inode_entry, list);
+		if (entry->inode == inode)
+			return -EEXIST;
+	}
+	list_add_tail(&new->list, head);
+#ifdef CONFIG_F2FS_STAT_FS
+	sbi->n_dirty_dirs++;
+#endif
+	return 0;
+}
+
+void set_dirty_dir_page(struct inode *inode, struct page *page)
+{
+	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
+	struct dir_inode_entry *new;
+
 	if (!S_ISDIR(inode->i_mode))
 		return;
 retry:
@@ -469,25 +486,31 @@
 	INIT_LIST_HEAD(&new->list);
 
 	spin_lock(&sbi->dir_inode_lock);
-	list_for_each(this, head) {
-		struct dir_inode_entry *entry;
-		entry = list_entry(this, struct dir_inode_entry, list);
-		if (entry->inode == inode) {
-			kmem_cache_free(inode_entry_slab, new);
-			goto out;
-		}
-	}
-	list_add_tail(&new->list, head);
-#ifdef CONFIG_F2FS_STAT_FS
-	sbi->n_dirty_dirs++;
-#endif
+	if (__add_dirty_inode(inode, new))
+		kmem_cache_free(inode_entry_slab, new);
 
-	BUG_ON(!S_ISDIR(inode->i_mode));
-out:
 	inc_page_count(sbi, F2FS_DIRTY_DENTS);
 	inode_inc_dirty_dents(inode);
 	SetPagePrivate(page);
+	spin_unlock(&sbi->dir_inode_lock);
+}
 
+void add_dirty_dir_inode(struct inode *inode)
+{
+	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
+	struct dir_inode_entry *new;
+retry:
+	new = kmem_cache_alloc(inode_entry_slab, GFP_NOFS);
+	if (!new) {
+		cond_resched();
+		goto retry;
+	}
+	new->inode = inode;
+	INIT_LIST_HEAD(&new->list);
+
+	spin_lock(&sbi->dir_inode_lock);
+	if (__add_dirty_inode(inode, new))
+		kmem_cache_free(inode_entry_slab, new);
 	spin_unlock(&sbi->dir_inode_lock);
 }