Commit 4bca7e80 authored by Jan Kara's avatar Jan Kara
Browse files

init: Initialize noop_backing_dev_info early 



noop_backing_dev_info is used by superblocks of various
pseudofilesystems such as kdevtmpfs. After commit 10e14073
("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: 10e14073 ("writeback: Fix inode->i_io_list not be protected by inode->i_lock error")
Reported-and-tested-by: default avatarSuzuki K Poulose <suzuki.poulose@arm.com>
Reported-and-tested-by: default avatarAlexandru Elisei <alexandru.elisei@arm.com>
Reported-and-tested-by: default avatarGuenter Roeck <linux@roeck-us.net>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarJan Kara <jack@suse.cz>
parent 27cfa258

drivers/base/init.c

+2 −0
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ 
#include <linux/init.h>

#include <linux/memory.h>

#include <linux/of.h>

#include <linux/backing-dev.h>



#include "base.h"
@@ -20,6 +21,7 @@ 
void __init driver_init(void)

{

	/* These are the core pieces */

	bdi_init(&noop_backing_dev_info);

	devtmpfs_init();

	devices_init();

	buses_init();

include/linux/backing-dev.h

+2 −0
Original line number Diff line number Diff line
@@ -119,6 +119,8 @@ int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ratio); 


extern struct backing_dev_info noop_backing_dev_info;



int bdi_init(struct backing_dev_info *bdi);



/**

 * writeback_in_progress - determine whether there is writeback in progress

 * @wb: bdi_writeback of interest

mm/backing-dev.c

+2 −9
Original line number Diff line number Diff line
@@ -231,20 +231,13 @@ static __init int bdi_class_init(void) 
}

postcore_initcall(bdi_class_init);



static int bdi_init(struct backing_dev_info *bdi);



static int __init default_bdi_init(void)

{

	int err;



	bdi_wq = alloc_workqueue("writeback", WQ_MEM_RECLAIM | WQ_UNBOUND |

				 WQ_SYSFS, 0);

	if (!bdi_wq)

		return -ENOMEM;



	err = bdi_init(&noop_backing_dev_info);



	return err;

	return 0;

}

subsys_initcall(default_bdi_init);
@@ -781,7 +774,7 @@ static void cgwb_remove_from_bdi_list(struct bdi_writeback *wb) 


#endif	/* CONFIG_CGROUP_WRITEBACK */



static int bdi_init(struct backing_dev_info *bdi)

int bdi_init(struct backing_dev_info *bdi)

{

	int ret;