From 4f4374a9bd25b333971e6f2656b642d29e2efe7b Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Wed, 18 Jul 2018 15:44:43 +0200 Subject: [PATCH] vfs: fix freeze protection in mnt_want_write_file() for overlayfs [ 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 Signed-off-by: Greg Kroah-Hartman --- fs/namespace.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/fs/namespace.c b/fs/namespace.c index 9dc146e7..3ee3ee5 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -446,10 +446,10 @@ int mnt_want_write_file_path(struct file *file) { int ret; - sb_start_write(file->f_path.mnt->mnt_sb); + sb_start_write(file_inode(file)->i_sb); ret = __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; } @@ -540,7 +540,8 @@ void __mnt_drop_write_file(struct file *file) 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); } void mnt_drop_write_file(struct file *file) -- 2.7.4