* [PATCH] CIFS: Fix read after write for files with read caching
@ 2019-03-05 1:48 Pavel Shilovsky
2019-03-05 2:37 ` ronnie sahlberg
0 siblings, 1 reply; 3+ messages in thread
From: Pavel Shilovsky @ 2019-03-05 1:48 UTC (permalink / raw)
To: linux-cifs; +Cc: smfrench
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
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] CIFS: Fix read after write for files with read caching
2019-03-05 1:48 [PATCH] CIFS: Fix read after write for files with read caching Pavel Shilovsky
@ 2019-03-05 2:37 ` ronnie sahlberg
0 siblings, 0 replies; 3+ messages in thread
From: ronnie sahlberg @ 2019-03-05 2:37 UTC (permalink / raw)
To: Pavel Shilovsky; +Cc: linux-cifs, Steve French
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
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* [PATCH] CIFS: Fix read after write for files with read caching
2019-03-05 23:51 [PATCH 0/3] more reconnect fixes Pavel Shilovsky
@ 2019-03-05 23:51 ` Pavel Shilovsky
0 siblings, 0 replies; 3+ messages in thread
From: Pavel Shilovsky @ 2019-03-05 23:51 UTC (permalink / raw)
To: linux-cifs, smfrench
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
^ permalink raw reply related [flat|nested] 3+ messages in thread
end of thread, other threads:[~2019-03-05 23:52 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-03-05 1:48 [PATCH] CIFS: Fix read after write for files with read caching Pavel Shilovsky
2019-03-05 2:37 ` ronnie sahlberg
2019-03-05 23:51 [PATCH 0/3] more reconnect fixes Pavel Shilovsky
2019-03-05 23:51 ` [PATCH] CIFS: Fix read after write for files with read caching Pavel Shilovsky
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).