1/*
2   Unix SMB/CIFS implementation.
3   IRIX kernel oplock processing
4   Copyright (C) Andrew Tridgell 1992-1998
5
6   This program is free software; you can redistribute it and/or modify
7   it under the terms of the GNU General Public License as published by
8   the Free Software Foundation; either version 2 of the License, or
9   (at your option) any later version.
10
11   This program is distributed in the hope that it will be useful,
12   but WITHOUT ANY WARRANTY; without even the implied warranty of
13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14   GNU General Public License for more details.
15
16   You should have received a copy of the GNU General Public License
17   along with this program; if not, write to the Free Software
18   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19*/
20
21#define DBGC_CLASS DBGC_LOCKING
22#include "includes.h"
23
24#if HAVE_KERNEL_OPLOCKS_IRIX
25
26static int oplock_pipe_write = -1;
27static int oplock_pipe_read = -1;
28
29/****************************************************************************
30 Test to see if IRIX kernel oplocks work.
31****************************************************************************/
32
33static BOOL irix_oplocks_available(void)
34{
35	int fd;
36	int pfd[2];
37	pstring tmpname;
38
39	set_effective_capability(KERNEL_OPLOCK_CAPABILITY);
40
41	slprintf(tmpname,sizeof(tmpname)-1, "%s/koplock.%d", lp_lockdir(),
42		 (int)sys_getpid());
43
44	if(pipe(pfd) != 0) {
45		DEBUG(0,("check_kernel_oplocks: Unable to create pipe. Error "
46			 "was %s\n",
47			 strerror(errno) ));
48		return False;
49	}
50
51	if((fd = sys_open(tmpname, O_RDWR|O_CREAT|O_EXCL|O_TRUNC, 0600)) < 0) {
52		DEBUG(0,("check_kernel_oplocks: Unable to open temp test file "
53			 "%s. Error was %s\n",
54			 tmpname, strerror(errno) ));
55		unlink( tmpname );
56		close(pfd[0]);
57		close(pfd[1]);
58		return False;
59	}
60
61	unlink(tmpname);
62
63	if(sys_fcntl_long(fd, F_OPLKREG, pfd[1]) == -1) {
64		DEBUG(0,("check_kernel_oplocks: Kernel oplocks are not "
65			 "available on this machine. Disabling kernel oplock "
66			 "support.\n" ));
67		close(pfd[0]);
68		close(pfd[1]);
69		close(fd);
70		return False;
71	}
72
73	if(sys_fcntl_long(fd, F_OPLKACK, OP_REVOKE) < 0 ) {
74		DEBUG(0,("check_kernel_oplocks: Error when removing kernel "
75			 "oplock. Error was %s. Disabling kernel oplock "
76			 "support.\n", strerror(errno) ));
77		close(pfd[0]);
78		close(pfd[1]);
79		close(fd);
80		return False;
81	}
82
83	close(pfd[0]);
84	close(pfd[1]);
85	close(fd);
86
87	return True;
88}
89
90/****************************************************************************
91 * Deal with the IRIX kernel <--> smbd
92 * oplock break protocol.
93****************************************************************************/
94
95static files_struct *irix_oplock_receive_message(fd_set *fds)
96{
97	extern int smb_read_error;
98	oplock_stat_t os;
99	char dummy;
100	files_struct *fsp;
101
102	/* Ensure we only get one call per select fd set. */
103	FD_CLR(oplock_pipe_read, fds);
104
105	/*
106	 * Read one byte of zero to clear the
107	 * kernel break notify message.
108	 */
109
110	if(read(oplock_pipe_read, &dummy, 1) != 1) {
111		DEBUG(0,("irix_oplock_receive_message: read of kernel "
112			 "notification failed. Error was %s.\n",
113			 strerror(errno) ));
114		smb_read_error = READ_ERROR;
115		return NULL;
116	}
117
118	/*
119	 * Do a query to get the
120	 * device and inode of the file that has the break
121	 * request outstanding.
122	 */
123
124	if(sys_fcntl_ptr(oplock_pipe_read, F_OPLKSTAT, &os) < 0) {
125		DEBUG(0,("irix_oplock_receive_message: fcntl of kernel "
126			 "notification failed. Error was %s.\n",
127			 strerror(errno) ));
128		if(errno == EAGAIN) {
129			/*
130			 * Duplicate kernel break message - ignore.
131			 */
132			return NULL;
133		}
134		smb_read_error = READ_ERROR;
135		return NULL;
136	}
137
138	/*
139	 * We only have device and inode info here - we have to guess that this
140	 * is the first fsp open with this dev,ino pair.
141	 */
142
143	if ((fsp = file_find_di_first((SMB_DEV_T)os.os_dev,
144				      (SMB_INO_T)os.os_ino)) == NULL) {
145		DEBUG(0,("irix_oplock_receive_message: unable to find open "
146			 "file with dev = %x, inode = %.0f\n",
147			 (unsigned int)os.os_dev, (double)os.os_ino ));
148		return NULL;
149	}
150
151	DEBUG(5,("irix_oplock_receive_message: kernel oplock break request "
152		 "received for dev = %x, inode = %.0f\n, file_id = %ul",
153		 (unsigned int)fsp->dev, (double)fsp->inode,
154		 fsp->fh->file_id ));
155
156	return fsp;
157}
158
159/****************************************************************************
160 Attempt to set an kernel oplock on a file.
161****************************************************************************/
162
163static BOOL irix_set_kernel_oplock(files_struct *fsp, int oplock_type)
164{
165	if (sys_fcntl_long(fsp->fh->fd, F_OPLKREG, oplock_pipe_write) == -1) {
166		if(errno != EAGAIN) {
167			DEBUG(0,("irix_set_kernel_oplock: Unable to get "
168				 "kernel oplock on file %s, dev = %x, inode "
169				 "= %.0f, file_id = %ul. Error was %s\n",
170				 fsp->fsp_name, (unsigned int)fsp->dev,
171				 (double)fsp->inode, fsp->fh->file_id,
172				 strerror(errno) ));
173		} else {
174			DEBUG(5,("irix_set_kernel_oplock: Refused oplock on "
175				 "file %s, fd = %d, dev = %x, inode = %.0f, "
176				 "file_id = %ul. Another process had the file "
177				 "open.\n",
178				 fsp->fsp_name, fsp->fh->fd,
179				 (unsigned int)fsp->dev, (double)fsp->inode,
180				 fsp->fh->file_id ));
181		}
182		return False;
183	}
184
185	DEBUG(10,("irix_set_kernel_oplock: got kernel oplock on file %s, dev "
186		  "= %x, inode = %.0f, file_id = %ul\n",
187		  fsp->fsp_name, (unsigned int)fsp->dev, (double)fsp->inode,
188		  fsp->fh->file_id));
189
190	return True;
191}
192
193/****************************************************************************
194 Release a kernel oplock on a file.
195****************************************************************************/
196
197static void irix_release_kernel_oplock(files_struct *fsp)
198{
199	if (DEBUGLVL(10)) {
200		/*
201		 * Check and print out the current kernel
202		 * oplock state of this file.
203		 */
204		int state = sys_fcntl_long(fsp->fh->fd, F_OPLKACK, -1);
205		dbgtext("irix_release_kernel_oplock: file %s, dev = %x, "
206			"inode = %.0f file_id = %ul, has kernel oplock state "
207			"of %x.\n", fsp->fsp_name, (unsigned int)fsp->dev,
208                        (double)fsp->inode, fsp->fh->file_id, state );
209	}
210
211	/*
212	 * Remove the kernel oplock on this file.
213	 */
214	if(sys_fcntl_long(fsp->fh->fd, F_OPLKACK, OP_REVOKE) < 0) {
215		if( DEBUGLVL( 0 )) {
216			dbgtext("irix_release_kernel_oplock: Error when "
217				"removing kernel oplock on file " );
218			dbgtext("%s, dev = %x, inode = %.0f, file_id = %ul. "
219				"Error was %s\n",
220				fsp->fsp_name, (unsigned int)fsp->dev,
221				(double)fsp->inode, fsp->fh->file_id,
222				strerror(errno) );
223		}
224	}
225}
226
227/****************************************************************************
228 See if there is a message waiting in this fd set.
229 Note that fds MAY BE NULL ! If so we must do our own select.
230****************************************************************************/
231
232static BOOL irix_oplock_msg_waiting(fd_set *fds)
233{
234	int selrtn;
235	fd_set myfds;
236	struct timeval to;
237
238	if (oplock_pipe_read == -1)
239		return False;
240
241	if (fds) {
242		return FD_ISSET(oplock_pipe_read, fds);
243	}
244
245	/* Do a zero-time select. We just need to find out if there
246	 * are any outstanding messages. We use sys_select_intr as
247	 * we need to ignore any signals. */
248
249	FD_ZERO(&myfds);
250	FD_SET(oplock_pipe_read, &myfds);
251
252	to = timeval_set(0, 0);
253	selrtn = sys_select_intr(oplock_pipe_read+1,&myfds,NULL,NULL,&to);
254	return (selrtn == 1) ? True : False;
255}
256
257/****************************************************************************
258 Setup kernel oplocks.
259****************************************************************************/
260
261struct kernel_oplocks *irix_init_kernel_oplocks(void)
262{
263	int pfd[2];
264	static struct kernel_oplocks koplocks;
265
266	if (!irix_oplocks_available())
267		return NULL;
268
269	if(pipe(pfd) != 0) {
270		DEBUG(0,("setup_kernel_oplock_pipe: Unable to create pipe. "
271			 "Error was %s\n", strerror(errno) ));
272		return False;
273	}
274
275	oplock_pipe_read = pfd[0];
276	oplock_pipe_write = pfd[1];
277
278	koplocks.receive_message = irix_oplock_receive_message;
279	koplocks.set_oplock = irix_set_kernel_oplock;
280	koplocks.release_oplock = irix_release_kernel_oplock;
281	koplocks.msg_waiting = irix_oplock_msg_waiting;
282	koplocks.notification_fd = oplock_pipe_read;
283
284	return &koplocks;
285}
286#else
287 void oplock_irix_dummy(void);
288 void oplock_irix_dummy(void) {}
289#endif /* HAVE_KERNEL_OPLOCKS_IRIX */
290