From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Sasha Levin To: "stable@vger.kernel.org" , "linux-kernel@vger.kernel.org" CC: Miklos Szeredi , Sasha Levin Subject: [PATCH AUTOSEL 4.14 06/57] vfs: fix freeze protection in mnt_want_write_file() for overlayfs Date: Sat, 15 Sep 2018 01:32:31 +0000 Message-ID: <20180915013223.179909-6-alexander.levin@microsoft.com> References: <20180915013223.179909-1-alexander.levin@microsoft.com> In-Reply-To: <20180915013223.179909-1-alexander.levin@microsoft.com> Content-Language: en-US Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: From: Miklos Szeredi [ Upstream commit a6795a585929d94ca3e931bc8518f8deb8bbe627 ] The underlying real file used by overlayfs still contains the overlay path. This results in mnt_want_write_file() calls by the filesystem getting freeze protection on the wrong inode (the overlayfs one instead of the real one). Fix by using file_inode(file)->i_sb instead of file->f_path.mnt->mnt_sb. Reported-by: Amir Goldstein Signed-off-by: Miklos Szeredi Reviewed-by: Christoph Hellwig Signed-off-by: Sasha Levin --- fs/namespace.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/fs/namespace.c b/fs/namespace.c index 9dc146e7b5e0..3ee3ee5819bc 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -446,10 +446,10 @@ int mnt_want_write_file_path(struct file *file) { int ret; =20 - sb_start_write(file->f_path.mnt->mnt_sb); + sb_start_write(file_inode(file)->i_sb); ret =3D __mnt_want_write_file(file); if (ret) - sb_end_write(file->f_path.mnt->mnt_sb); + sb_end_write(file_inode(file)->i_sb); return ret; } =20 @@ -540,7 +540,8 @@ void __mnt_drop_write_file(struct file *file) =20 void mnt_drop_write_file_path(struct file *file) { - mnt_drop_write(file->f_path.mnt); + __mnt_drop_write_file(file); + sb_end_write(file_inode(file)->i_sb); } =20 void mnt_drop_write_file(struct file *file) --=20 2.17.1