Messages in this thread | | | Date | Thu, 16 Jun 2022 09:10:23 +0100 | Subject | Re: [PATCH] init: Initialize noop_backing_dev_info early | From | Suzuki K Poulose <> |
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On 15/06/2022 22:48, Jan Kara wrote: > 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-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> > Signed-off-by: Jan Kara <jack@suse.cz>
Works for me too. Thanks for the proper fix
Tested-by: Suzuki K Poulose <suzuki.poulose@arm.com>
> --- > drivers/base/init.c | 2 ++ > include/linux/backing-dev.h | 2 ++ > mm/backing-dev.c | 11 ++--------- > 3 files changed, 6 insertions(+), 9 deletions(-) > > Since this bug prevents some machines from booting, I plan to push this patch > to Linus unless someone objects soon... Review is welcome :). > > diff --git a/drivers/base/init.c b/drivers/base/init.c > index d8d0fe687111..397eb9880cec 100644 > --- a/drivers/base/init.c > +++ b/drivers/base/init.c > @@ -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(); > diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h > index 2bd073fa6bb5..f0baef68f90f 100644 > --- a/include/linux/backing-dev.h > +++ b/include/linux/backing-dev.h > @@ -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; > > +extern int bdi_init(struct backing_dev_info *bdi); > + > /** > * writeback_in_progress - determine whether there is writeback in progress > * @wb: bdi_writeback of interest > diff --git a/mm/backing-dev.c b/mm/backing-dev.c > index ff60bd7d74e0..95550b8fa7fe 100644 > --- a/mm/backing-dev.c > +++ b/mm/backing-dev.c > @@ -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; >
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