On 01/05/2011 04:29 PM, Trond Myklebust wrote:
> On Wed, 2011-01-05 at 10:14 -0500, Trond Myklebust wrote:
>> OK. So,the new behaviour in 2.6.37 is that we're writing to a series of
>> pages via the usual kmap_atomic()/kunmap_atomic() and kmap()/kunmap()
>> interfaces, but we can end up reading them via a virtual address range
>> that gets set up via vm_map_ram() (that range gets set up before the
>> write occurs).
>>
>> Do we perhaps need an invalidate_kernel_vmap_range() before we can read
>> the data on ARM in this kind of scenario?
>
> IOW: Does something like the following patch fix the problem?
>
> -------------------------------------------------------------------------------
> From: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx>
> NFS: Ensure we clean the TLB cache in nfs_readdir_xdr_to_array
>
> After calling nfs_readdir_xdr_filler(), we need a call to
> invalidate_kernel_vmap_range() before we can proceed to read
> the data back through the virtual address range.
>
> Signed-off-by: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx>
> ---
> diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
> index 996dd89..4640470 100644
> --- a/fs/nfs/dir.c
> +++ b/fs/nfs/dir.c
> @@ -587,6 +587,9 @@ int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page,
> if (status < 0)
> break;
> pglen = status;
> +
> + invalidate_kernel_vmap_range(pages_ptr, pglen);
> +
> status = nfs_readdir_page_filler(desc, &entry, pages_ptr, page, pglen);
> if (status < 0) {
> if (status == -ENOSPC)
\o/ - Works for me (at91, armv5)
Tested-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
This is a candidate for stable (Cc'd).
Regards,
Marc
--
Pengutronix e.K. | Marc Kleine-Budde |
Industrial Linux Solutions | Phone: +49-231-2826-924 |
Vertretung West/Dortmund | Fax: +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de |
Attachment:
signature.asc
Description: OpenPGP digital signature
