init: Initialize noop_backing_dev_info early
authorJan Kara <jack@suse.cz>
Wed, 15 Jun 2022 13:22:29 +0000 (15:22 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 22 Jun 2022 12:22:02 +0000 (14:22 +0200)
commitca67881dcef04c5b586a3b122307b183babd62dc
treeb1b871e968ada1d3d065dde221d261e505d4133d
parent04cdec41862642107f444db792c94e9bff1d9b4a
init: Initialize noop_backing_dev_info early

[ Upstream commit 4bca7e80b6455772b4bf3f536dcbc19aac424d6a ]

noop_backing_dev_info is used by superblocks of various
pseudofilesystems such as kdevtmpfs. After commit 10e14073107d
("writeback: Fix inode->i_io_list not be protected by inode->i_lock
error") this broke because __mark_inode_dirty() started to access more
fields from noop_backing_dev_info and this led to crashes inside
locked_inode_to_wb_and_lock_list() called from __mark_inode_dirty().
Fix the problem by initializing noop_backing_dev_info before the
filesystems get mounted.

Fixes: 10e14073107d ("writeback: Fix inode->i_io_list not be protected by inode->i_lock error")
Reported-and-tested-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reported-and-tested-by: Alexandru Elisei <alexandru.elisei@arm.com>
Reported-and-tested-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Sasha Levin <sashal@kernel.org>
drivers/base/init.c
include/linux/backing-dev.h
mm/backing-dev.c