[CIFS] Do not block on FindNotify response

Signed-off-by: Steve French (sfrench@us.ibm.com)

fs/cifs/CHANGES

+Version 1.27
+------------
+Turn off DNOTIFY (directory change notification support) by default
+(unless built with the experimental flag) to fix hang with KDE
+file browser. Fix DNOTIFY flag mappings.  Fix hang (in wait_event
+waiting on an SMB response) in SendReceive when session dies but
+reconnects quickly from another task.
+
 Version 1.26
 ------------
 Add setfacl support to allow setting of ACLs remotely to Samba 3.10 and later

fs/cifs/cifsfs.h

@@ -90,5 +90,5 @@ extern int 	cifs_setxattr(struct dentry *, const char *, const void *,
 			 size_t, int);
 extern ssize_t	cifs_getxattr(struct dentry *, const char *, void *, size_t);
 extern ssize_t	cifs_listxattr(struct dentry *, char *, size_t);
-#define CIFS_VERSION   "1.26"
+#define CIFS_VERSION   "1.27"
 #endif				/* _CIFSFS_H */

fs/cifs/cifssmb.c

@@ -3772,7 +3772,7 @@ int CIFSSMBNotify(const int xid, struct cifsTconInfo *tcon,
 	pSMB->ByteCount = 0;
 
 	rc = SendReceive(xid, tcon->ses, (struct smb_hdr *) pSMB,
-			(struct smb_hdr *) pSMBr, &bytes_returned, 0);
+			(struct smb_hdr *) pSMBr, &bytes_returned, -1);
 	if (rc) {
 		cFYI(1, ("Error in Notify = %d", rc));
 	}

fs/cifs/misc.c

@@ -175,7 +175,7 @@ cifs_buf_release(void *buf_to_free)
 {
 
 	if (buf_to_free == NULL) {
-		cFYI(1, ("Null buffer passed to cifs_buf_release"));
+		/* cFYI(1, ("Null buffer passed to cifs_buf_release"));*/
 		return;
 	}
 	mempool_free(buf_to_free,cifs_req_poolp);
@@ -390,8 +390,29 @@ is_valid_oplock_break(struct smb_hdr *buf)
 	struct cifsTconInfo *tcon;
 	struct cifsFileInfo *netfile;
 
-	/* could add check for smb response flag 0x80 */
-	cFYI(1,("Checking for oplock break"));    
+	cFYI(1,("Checking for oplock break or dnotify response"));
+	if((pSMB->hdr.Command == SMB_COM_NT_TRANSACT) &&
+	   (pSMB->hdr.Flags & SMBFLG_RESPONSE)) {
+		struct smb_com_transaction_change_notify_rsp * pSMBr =
+			(struct smb_com_transaction_change_notify_rsp *)buf;
+		struct file_notify_information * pnotify;
+		__u32 data_offset = 0;
+		if(pSMBr->ByteCount > sizeof(struct file_notify_information)) {
+			data_offset = le32_to_cpu(pSMBr->DataOffset);
+
+			pnotify = (struct file_notify_information *)((char *)&pSMBr->hdr.Protocol
+				+ data_offset);
+			cFYI(1,("dnotify on %s with action: 0x%x",pnotify->FileName,
+				pnotify->Action));  /* BB removeme BB */
+	             /*   cifs_dump_mem("Received notify Data is: ",buf,sizeof(struct smb_hdr)+60); */
+			return TRUE;
+		}
+		if(pSMBr->hdr.Status.CifsError) {
+			cFYI(1,("notify err 0x%d",pSMBr->hdr.Status.CifsError));
+			return TRUE;
+		}
+		return FALSE;
+	}  
 	if(pSMB->hdr.Command != SMB_COM_LOCKING_ANDX)
 		return FALSE;
 	if(pSMB->hdr.Flags & SMBFLG_RESPONSE) {