CIFS: Add rwpidforward mount option

Add rwpidforward mount option that switches on a mode when we forward
pid of a process who opened a file to any read and write operation.

This can prevent applications like WINE from failing on read or write
operation on a previously locked file region from the same netfd from
another process if we use mandatory brlock style.

It is actual for WINE because during a run of WINE program two processes
work on the same netfd - share the same file struct between several VFS
fds:
1) WINE-server does open and lock;
2) WINE-application does read and write.

Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <sfrench@us.ibm.com>

1 files changed, 2 insertions, 3 deletions

diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index e41f6071cdd2..17063455918f 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -345,9 +345,8 @@ extern int CIFSSMBClose(const int xid, struct cifsTconInfo *tcon,
 extern int CIFSSMBFlush(const int xid, struct cifsTconInfo *tcon,
                         const int smb_file_id);
 
-extern int CIFSSMBRead(const int xid, struct cifsTconInfo *tcon,
-                        const int netfid, unsigned int count,
-                        const __u64 lseek, unsigned int *nbytes, char **buf,
+extern int CIFSSMBRead(const int xid, struct cifs_io_parms *io_parms,
+                        unsigned int *nbytes, char **buf,
                         int *return_buf_type);
 extern int CIFSSMBWrite(const int xid, struct cifs_io_parms *io_parms,
                         unsigned int *nbytes, const char *buf,