tentatively merged into cifs-2.6.git for-next pending testing and any
additional review

On Tue, Jun 18, 2024 at 3:56 AM Barry Song <21cnbao@gmail.com> wrote:

> From: Barry Song <v-songbaohua@oppo.com>
>
> Since commit 2282679fb20b ("mm: submit multipage write for SWP_FS_OPS
> swap-space"), we can plug multiple pages then unplug them all together.
> That means iov_iter_count(iter) could be way bigger than PAGE_SIZE, it
> actually equals the size of iov_iter_npages(iter, INT_MAX).
>
> Note this issue has nothing to do with large folios as we don't support
> THP_SWPOUT to non-block devices.
>
> Fixes: 2282679fb20b ("mm: submit multipage write for SWP_FS_OPS
> swap-space")
> Reported-by: Christoph Hellwig <hch@lst.de>
> Closes:
> https://lore.kernel.org/linux-mm/20240614100329.1203579-1-hch@lst.de/
> Cc: NeilBrown <neilb@suse.de>
> Cc: Anna Schumaker <anna@kernel.org>
> Cc: Steve French <sfrench@samba.org>
> Cc: Trond Myklebust <trondmy@kernel.org>
> Cc: Chuanhua Han <hanchuanhua@oppo.com>
> Cc: Ryan Roberts <ryan.roberts@arm.com>
> Cc: Chris Li <chrisl@kernel.org>
> Cc: "Huang, Ying" <ying.huang@intel.com>
> Cc: Jeff Layton <jlayton@kernel.org>
> Cc: Paulo Alcantara <pc@manguebit.com>
> Cc: Ronnie Sahlberg <ronniesahlberg@gmail.com>
> Cc: Shyam Prasad N <sprasad@microsoft.com>
> Cc: Tom Talpey <tom@talpey.com>
> Cc: Bharath SM <bharathsm@microsoft.com>
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Barry Song <v-songbaohua@oppo.com>
> ---
>  -v2:
>  * drop the assertion instead of fixing the assertion.
>    per the comments of Willy, Christoph in nfs thread.
>
>  fs/smb/client/file.c | 2 --
>  1 file changed, 2 deletions(-)
>
> diff --git a/fs/smb/client/file.c b/fs/smb/client/file.c
> index 9d5c2440abfc..1e269e0bc75b 100644
> --- a/fs/smb/client/file.c
> +++ b/fs/smb/client/file.c
> @@ -3200,8 +3200,6 @@ static int cifs_swap_rw(struct kiocb *iocb, struct
> iov_iter *iter)
>  {
>         ssize_t ret;
>
> -       WARN_ON_ONCE(iov_iter_count(iter) != PAGE_SIZE);
> -
>         if (iov_iter_rw(iter) == READ)
>                 ret = netfs_unbuffered_read_iter_locked(iocb, iter);
>         else
> --
> 2.34.1
>
>
>

-- 
Thanks,

Steve