Reviewed-by: Ronnie Sahlberg <lsahlber@xxxxxxxxxx>
On Tue, Mar 5, 2019 at 11:48 AM Pavel Shilovsky <piastryyy@xxxxxxxxx> wrote:
>
> When we have a READ lease for a file and have just issued a write
> operation to the server we need to purge the cache and set oplock/lease
> level to NONE to avoid reading stale data. Currently we do that
> only if a write operation succedeed thus not covering cases when
> a request was sent to the server but a negative error code was
> returned later for some other reasons (e.g. -EIOCBQUEUED or -EINTR).
> Fix this by turning off caching regardless of the error code being
> returned.
>
> The patches fixes generic tests 075 and 112 from the xfs-tests.
>
> Cc: <stable@xxxxxxxxxxxxxxx>
> Signed-off-by: Pavel Shilovsky <pshilov@xxxxxxxxxxxxx>
> ---
> fs/cifs/file.c | 12 +++++++-----
> 1 file changed, 7 insertions(+), 5 deletions(-)
>
> diff --git a/fs/cifs/file.c b/fs/cifs/file.c
> index 9b53f33..4c144c1 100644
> --- a/fs/cifs/file.c
> +++ b/fs/cifs/file.c
> @@ -3096,14 +3096,16 @@ cifs_strict_writev(struct kiocb *iocb, struct iov_iter *from)
> * these pages but not on the region from pos to ppos+len-1.
> */
> written = cifs_user_writev(iocb, from);
> - if (written > 0 && CIFS_CACHE_READ(cinode)) {
> + if (CIFS_CACHE_READ(cinode)) {
> /*
> - * Windows 7 server can delay breaking level2 oplock if a write
> - * request comes - break it on the client to prevent reading
> - * an old data.
> + * We have read level caching and we have just sent a write
> + * request to the server thus making data in the cache stale.
> + * Zap the cache and set oplock/lease level to NONE to avoid
> + * reading stale data from the cache. All subsequent read
> + * operations will read new data from the server.
> */
> cifs_zap_mapping(inode);
> - cifs_dbg(FYI, "Set no oplock for inode=%p after a write operation\n",
> + cifs_dbg(FYI, "Set Oplock/Lease to NONE for inode=%p after write\n",
> inode);
> cinode->oplock = 0;
> }
> --
> 2.7.4
>
