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CIFS: Fix read after write for files with read caching

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commit 6dfbd84684700cb58b34e8602c01c12f3d2595c8 upstream.

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>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Pavel Shilovsky 2019-03-04 17:48:01 -08:00 committed by Greg Kroah-Hartman
parent dc8e8ad962
commit 43eaa6cc17
1 changed files with 7 additions and 5 deletions
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12
fs/cifs/file.c
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@ -2871,14 +2871,16 @@ 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;
}