f2fs: avoid trying to get invalid block address

In f2fs_new_inode(), if we fail to get a new inode, we go iput(), followed by
f2fs_evict_inode(). If the inode is not marked as bad, it'll try to call
f2fs_remove_inode_page() which tries to read the inode block given node id.
But, there's no block address allocated yet, which gives a chance to access
a wrong block address, if the block device has some garbage data in NAT table.

We need to make sure NAT table should have zero data for all the unallocated
node ids, but also would be better to take this unnecessary path as well.
Let's mark the faild inode as bad.

Fixes: 0abd675e97 ("f2fs: support plain user/group quota")
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/namei.c

@@ -341,6 +341,7 @@ fail_drop:
 	trace_f2fs_new_inode(inode, err);
 	dquot_drop(inode);
 	inode->i_flags |= S_NOQUOTA;
+	make_bad_inode(inode);
 	if (nid_free)
 		set_inode_flag(inode, FI_FREE_NID);
 	clear_nlink(inode);