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>
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index 53ea625..e2d9dd8 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -374,6 +374,7 @@
__u16 netfid;
struct tcon_link *tlink;
struct cifsTconInfo *tcon;
+ struct cifs_io_parms io_parms;
char buf[24];
unsigned int bytes_read;
char *pbuf;
@@ -405,9 +406,13 @@
if (rc == 0) {
int buf_type = CIFS_NO_BUFFER;
/* Read header */
- rc = CIFSSMBRead(xid, tcon, netfid,
- 24 /* length */, 0 /* offset */,
- &bytes_read, &pbuf, &buf_type);
+ io_parms.netfid = netfid;
+ io_parms.pid = current->tgid;
+ io_parms.tcon = tcon;
+ io_parms.offset = 0;
+ io_parms.length = 24;
+ rc = CIFSSMBRead(xid, &io_parms, &bytes_read, &pbuf,
+ &buf_type);
if ((rc == 0) && (bytes_read >= 8)) {
if (memcmp("IntxBLK", pbuf, 8) == 0) {
cFYI(1, "Block device");