a first pass at Linux kernel oplocks support

(This used to be commit 3253085d9883a181c04b9c9ecf7d0ccdfbcee88d)

1 files changed, 205 insertions, 0 deletions

diff --git a/source3/smbd/oplock_linux.c b/source3/smbd/oplock_linux.c
new file mode 100644
index 0000000000..d8496ca9ca
--- /dev/null
+++ b/source3/smbd/oplock_linux.c
@@ -0,0 +1,205 @@
+#define OLD_NTDOMAIN 1
+#if HAVE_KERNEL_OPLOCKS_LINUX
+
+/* 
+   Unix SMB/Netbios implementation.
+   Version 3.0
+   kernel oplock processing for Linux
+   Copyright (C) Andrew Tridgell 2000
+   
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+   
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+   
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#include "includes.h"
+
+extern int DEBUGLEVEL;
+
+static unsigned signals_received;
+static unsigned signals_processed;
+static int fd_pending; /* the fd of the current pending SIGIO */
+
+/****************************************************************************
+handle a SIGIO, incrementing the signals_received and blocking SIGIO
+****************************************************************************/
+static void sigio_handler(int signal, siginfo_t *info, void *unused)
+{
+	fd_pending = info->si_fd;
+	signals_received++;
+	BlockSignals(True, SIGIO);
+}
+
+/****************************************************************************
+ * Deal with the Linux kernel <--> smbd
+ * oplock break protocol.
+****************************************************************************/
+static BOOL linux_oplock_receive_message(fd_set *fds, char *buffer, int buffer_len)
+{
+	SMB_DEV_T dev;
+	SMB_INO_T inode;
+	SMB_STRUCT_STAT sbuf;
+	BOOL ret;
+
+	if (signals_received == signals_processed) return False;
+
+	if (sys_fstat(fd_pending,&sbuf) == -1) {
+		DEBUG(0,("Invalid file descriptor %d in kernel oplock break!\n", fd_pending));
+		ret = False;
+		goto out;
+	}
+
+	dev = sbuf.st_dev;
+	inode = sbuf.st_ino;
+     
+	DEBUG(5,("receive_local_message: kernel oplock break request received for \
+dev = %x, inode = %.0f\n", (unsigned int)dev, (double)inode ));
+     
+	/*
+	 * Create a kernel oplock break message.
+	 */
+     
+	/* Setup the message header */
+	SIVAL(buffer,OPBRK_CMD_LEN_OFFSET,KERNEL_OPLOCK_BREAK_MSG_LEN);
+	SSVAL(buffer,OPBRK_CMD_PORT_OFFSET,0);
+     
+	buffer += OPBRK_CMD_HEADER_LEN;
+     
+	SSVAL(buffer,OPBRK_MESSAGE_CMD_OFFSET,KERNEL_OPLOCK_BREAK_CMD);
+     
+	memcpy(buffer + KERNEL_OPLOCK_BREAK_DEV_OFFSET, (char *)&dev, sizeof(dev));
+	memcpy(buffer + KERNEL_OPLOCK_BREAK_INODE_OFFSET, (char *)&inode, sizeof(inode));	
+
+ out:
+	/* now we can receive more signals */
+	fd_pending = -1;
+	signals_processed++;
+	BlockSignals(False, SIGIO);
+     
+	return True;
+}
+
+
+/****************************************************************************
+ Attempt to set an kernel oplock on a file.
+****************************************************************************/
+static BOOL linux_set_kernel_oplock(files_struct *fsp, int oplock_type)
+{
+	if (fcntl(fsp->fd, F_SETLEASE, F_WRLCK) == -1) {
+		DEBUG(5,("set_file_oplock: Refused oplock on file %s, fd = %d, dev = %x, \
+inode = %.0f.\n",
+			 fsp->fsp_name, fsp->fd, (unsigned int)fsp->dev, (double)fsp->inode));
+		return False;
+	}
+	
+	DEBUG(10,("set_file_oplock: got kernel oplock on file %s, dev = %x, inode = %.0f\n",
+		  fsp->fsp_name, (unsigned int)fsp->dev, (double)fsp->inode));
+
+	return True;
+}
+
+
+/****************************************************************************
+ Release a kernel oplock on a file.
+****************************************************************************/
+static void linux_release_kernel_oplock(files_struct *fsp)
+{
+	if (DEBUGLVL(10)) {
+		/*
+		 * Check and print out the current kernel
+		 * oplock state of this file.
+		 */
+		int state = fcntl(fsp->fd, F_GETLEASE, 0);
+		dbgtext("release_kernel_oplock: file %s, dev = %x, inode = %.0f has kernel \
+oplock state of %x.\n", fsp->fsp_name, (unsigned int)fsp->dev,
+                        (double)fsp->inode, state );
+	}
+
+	/*
+	 * Remove the kernel oplock on this file.
+	 */
+	if (fcntl(fsp->fd, F_SETLEASE, F_UNLCK) == -1) {
+		if (DEBUGLVL(0)) {
+			dbgtext("release_kernel_oplock: Error when removing kernel oplock on file " );
+			dbgtext("%s, dev = %x, inode = %.0f. Error was %s\n",
+				fsp->fsp_name, (unsigned int)fsp->dev, 
+				(double)fsp->inode, strerror(errno) );
+		}
+	}
+}
+
+
+/****************************************************************************
+parse a kernel oplock message
+****************************************************************************/
+static BOOL linux_kernel_oplock_parse(char *msg_start, int msg_len, SMB_INO_T *inode, SMB_DEV_T *dev)
+{
+	/* Ensure that the msg length is correct. */
+	if (msg_len != KERNEL_OPLOCK_BREAK_MSG_LEN) {
+		DEBUG(0,("process_local_message: incorrect length for KERNEL_OPLOCK_BREAK_CMD (was %d, \
+should be %d).\n", msg_len, KERNEL_OPLOCK_BREAK_MSG_LEN));
+		return False;
+	}
+
+        memcpy((char *)inode, msg_start+KERNEL_OPLOCK_BREAK_INODE_OFFSET, sizeof(*inode));
+        memcpy((char *)dev, msg_start+KERNEL_OPLOCK_BREAK_DEV_OFFSET, sizeof(*dev));
+
+        DEBUG(5,("process_local_message: kernel oplock break request for \
+file dev = %x, inode = %.0f\n", (unsigned int)dev, (double)inode));
+
+	return True;
+}
+
+
+/****************************************************************************
+see if a oplock message is waiting
+****************************************************************************/
+static BOOL linux_oplock_msg_waiting(fd_set *fds)
+{
+	return signals_processed != signals_received;
+}
+
+
+/****************************************************************************
+setup kernel oplocks
+****************************************************************************/
+struct kernel_oplocks *linux_init_kernel_oplocks(void) 
+{
+	static struct kernel_oplocks koplocks;
+        struct sigaction act;
+
+        act.sa_handler = NULL;
+        act.sa_sigaction = sigio_handler;
+        act.sa_flags = SA_SIGINFO;
+        if (sigaction(SIGIO, &act, NULL) != 0) {
+		DEBUG(0,("Failed to setup SIGIO handler\n"));
+		return NULL;
+        }
+
+	koplocks.receive_message = linux_oplock_receive_message;
+	koplocks.set_oplock = linux_set_kernel_oplock;
+	koplocks.release_oplock = linux_release_kernel_oplock;
+	koplocks.parse_message = linux_kernel_oplock_parse;
+	koplocks.msg_waiting = linux_oplock_msg_waiting;
+	koplocks.notification_fd = -1;
+
+	return &koplocks;
+}
+
+
+
+#else
+ void oplock_linux_dummy(void) {}
+#endif /* HAVE_KERNEL_OPLOCKS_LINUX */
+
+#undef OLD_NTDOMAIN