From a6795a585929d94ca3e931bc8518f8deb8bbe627 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 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 --- fs/namespace.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/fs/namespace.c b/fs/namespace.c index c16921dba157..9be2e938d36f 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -441,10 +441,10 @@ int mnt_want_write_file(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; } EXPORT_SYMBOL_GPL(mnt_want_write_file); @@ -486,7 +486,8 @@ void __mnt_drop_write_file(struct file *file) void mnt_drop_write_file(struct file *file) { - mnt_drop_write(file->f_path.mnt); + __mnt_drop_write_file(file); + sb_end_write(file_inode(file)->i_sb); } EXPORT_SYMBOL(mnt_drop_write_file);