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/cifssmb.c b/fs/cifs/cifssmb.c
index f39fa08..19fd815 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -1382,8 +1382,7 @@
}
int
-CIFSSMBRead(const int xid, struct cifsTconInfo *tcon, const int netfid,
- const unsigned int count, const __u64 lseek, unsigned int *nbytes,
+CIFSSMBRead(const int xid, struct cifs_io_parms *io_parms, unsigned int *nbytes,
char **buf, int *pbuf_type)
{
int rc = -EACCES;
@@ -1393,13 +1392,18 @@
int wct;
int resp_buf_type = 0;
struct kvec iov[1];
+ __u32 pid = io_parms->pid;
+ __u16 netfid = io_parms->netfid;
+ __u64 offset = io_parms->offset;
+ struct cifsTconInfo *tcon = io_parms->tcon;
+ unsigned int count = io_parms->length;
cFYI(1, "Reading %d bytes on fid %d", count, netfid);
if (tcon->ses->capabilities & CAP_LARGE_FILES)
wct = 12;
else {
wct = 10; /* old style read */
- if ((lseek >> 32) > 0) {
+ if ((offset >> 32) > 0) {
/* can not handle this big offset for old */
return -EIO;
}
@@ -1410,15 +1414,18 @@
if (rc)
return rc;
+ pSMB->hdr.Pid = cpu_to_le16((__u16)pid);
+ pSMB->hdr.PidHigh = cpu_to_le16((__u16)(pid >> 16));
+
/* tcon and ses pointer are checked in smb_init */
if (tcon->ses->server == NULL)
return -ECONNABORTED;
pSMB->AndXCommand = 0xFF; /* none */
pSMB->Fid = netfid;
- pSMB->OffsetLow = cpu_to_le32(lseek & 0xFFFFFFFF);
+ pSMB->OffsetLow = cpu_to_le32(offset & 0xFFFFFFFF);
if (wct == 12)
- pSMB->OffsetHigh = cpu_to_le32(lseek >> 32);
+ pSMB->OffsetHigh = cpu_to_le32(offset >> 32);
pSMB->Remaining = 0;
pSMB->MaxCount = cpu_to_le16(count & 0xFFFF);