| Message ID | 1551750481-17919-1-git-send-email-pshilov@microsoft.com |
|---|---|
| State | New |
| Headers | show |
| Series | CIFS: Fix read after write for files with read caching | expand |
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com> On Tue, Mar 5, 2019 at 11:48 AM Pavel Shilovsky <piastryyy@gmail.com> 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@vger.kernel.org> > Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com> > --- > 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 >
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; }
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@vger.kernel.org> Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com> --- fs/cifs/file.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-)