Re: [PATCH 1/2] dax: Check page->mapping isn't NULL

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Tue 27-11-18 13:16:33, Matthew Wilcox wrote:
> If we race with inode destroy, it's possible for page->mapping to be
> NULL before we even enter this routine, as well as after having slept
> waiting for the dax entry to become unlocked.
> 
> Fixes: c2a7d2a11552 ("filesystem-dax: Introduce dax_lock_mapping_entry()")
> Cc: stable@xxxxxxxxxxxxxxx
> Reported-by: Jan Kara <jack@xxxxxxx>
> Signed-off-by: Matthew Wilcox <willy@xxxxxxxxxxxxx>

Thanks for writing this fix. The patch looks good. You can add:

Reviewed-by: Jan Kara <jack@xxxxxxx>

								Honza

> ---
>  fs/dax.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/dax.c b/fs/dax.c
> index 9bcce89ea18e..e69fc231833b 100644
> --- a/fs/dax.c
> +++ b/fs/dax.c
> @@ -365,7 +365,7 @@ bool dax_lock_mapping_entry(struct page *page)
>  		struct address_space *mapping = READ_ONCE(page->mapping);
>  
>  		locked = false;
> -		if (!dax_mapping(mapping))
> +		if (!mapping || !dax_mapping(mapping))
>  			break;
>  
>  		/*
> -- 
> 2.19.1
> 
-- 
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR



[Index of Archives]     [Linux Kernel]     [Kernel Development Newbies]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Hiking]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux