2 Unix SMB/CIFS implementation.
3 kernel oplock processing for Linux
4 Copyright (C) Andrew Tridgell 2000
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 3 of the License, or
9 (at your option) any later version.
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.
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>.
20 #define DBGC_CLASS DBGC_LOCKING
22 #include "system/filesys.h"
23 #include "smbd/smbd.h"
24 #include "smbd/globals.h"
26 #ifdef HAVE_KERNEL_OPLOCKS_LINUX
29 #define F_SETLEASE 1024
33 #define F_GETLEASE 1025
40 #ifndef RT_SIGNAL_LEASE
41 #define RT_SIGNAL_LEASE (SIGRTMIN+1)
49 * public function to get linux lease capability. Needed by some VFS modules (eg. gpfs.c)
51 void linux_set_lease_capability(void)
53 set_effective_capability(LEASE_CAPABILITY);
57 * Call to set the kernel lease signal handler
59 int linux_set_lease_sighandler(int fd)
61 if (fcntl(fd, F_SETSIG, RT_SIGNAL_LEASE) == -1) {
62 DEBUG(3,("Failed to set signal handler for kernel lease\n"));
69 /****************************************************************************
70 Call SETLEASE. If we get EACCES then we try setting up the right capability and
72 Use the SMB_VFS_LINUX_SETLEASE instead of this call directly.
73 ****************************************************************************/
75 int linux_setlease(int fd, int leasetype)
81 * Ensure the lease owner is root to allow
82 * correct delivery of lease-break signals.
87 /* First set the signal handler. */
88 if (linux_set_lease_sighandler(fd) == -1) {
93 ret = fcntl(fd, F_SETLEASE, leasetype);
108 /****************************************************************************
109 * Deal with the Linux kernel <--> smbd
110 * oplock break protocol.
111 ****************************************************************************/
113 static void linux_oplock_signal_handler(struct tevent_context *ev_ctx,
114 struct tevent_signal *se,
115 int signum, int count,
116 void *_info, void *private_data)
118 struct kernel_oplocks *ctx =
119 talloc_get_type_abort(private_data,
120 struct kernel_oplocks);
121 struct smbd_server_connection *sconn =
122 talloc_get_type_abort(ctx->private_data,
123 struct smbd_server_connection);
124 siginfo_t *info = (siginfo_t *)_info;
125 int fd = info->si_fd;
128 fsp = file_find_fd(sconn, fd);
130 DEBUG(0,("linux_oplock_signal_handler: failed to find fsp for file fd=%d (file was closed ?)\n", fd ));
133 break_kernel_oplock(sconn->msg_ctx, fsp);
136 /****************************************************************************
137 Attempt to set an kernel oplock on a file.
138 ****************************************************************************/
140 static bool linux_set_kernel_oplock(struct kernel_oplocks *ctx,
141 files_struct *fsp, int oplock_type)
143 struct file_id_buf idbuf;
145 if ( SMB_VFS_LINUX_SETLEASE(fsp, F_WRLCK) == -1) {
146 DBG_NOTICE("Refused oplock on file %s, "
147 "fd = %d, file_id = %s. (%s)\n",
150 file_id_str_buf(fsp->file_id, &idbuf),
155 DBG_NOTICE("got kernel oplock on file %s, "
156 "file_id = %s gen_id = %"PRIu64"\n",
158 file_id_str_buf(fsp->file_id, &idbuf),
164 /****************************************************************************
165 Release a kernel oplock on a file.
166 ****************************************************************************/
168 static void linux_release_kernel_oplock(struct kernel_oplocks *ctx,
169 files_struct *fsp, int oplock_type)
173 * Check and print out the current kernel
174 * oplock state of this file.
176 int state = fcntl(fsp->fh->fd, F_GETLEASE, 0);
177 dbgtext("linux_release_kernel_oplock: file %s, file_id = %s "
178 "gen_id = %"PRIu64" has kernel oplock state "
181 file_id_string_tos(&fsp->file_id),
187 * Remove the kernel oplock on this file.
189 if ( SMB_VFS_LINUX_SETLEASE(fsp, F_UNLCK) == -1) {
191 dbgtext("linux_release_kernel_oplock: Error when "
192 "removing kernel oplock on file " );
193 dbgtext("%s, file_id = %s, gen_id = %"PRIu64". "
196 file_id_string_tos(&fsp->file_id),
203 /****************************************************************************
204 See if the kernel supports oplocks.
205 ****************************************************************************/
207 static bool linux_oplocks_available(void)
210 fd = open("/dev/null", O_RDONLY);
212 return False; /* uggh! */
213 ret = fcntl(fd, F_GETLEASE, 0);
215 return ret == F_UNLCK;
218 /****************************************************************************
219 Setup kernel oplocks.
220 ****************************************************************************/
222 static const struct kernel_oplocks_ops linux_koplocks = {
223 .set_oplock = linux_set_kernel_oplock,
224 .release_oplock = linux_release_kernel_oplock,
227 struct kernel_oplocks *linux_init_kernel_oplocks(struct smbd_server_connection *sconn)
229 struct kernel_oplocks *ctx;
230 struct tevent_signal *se;
232 if (!linux_oplocks_available()) {
233 DEBUG(3,("Linux kernel oplocks not available\n"));
237 ctx = talloc_zero(sconn, struct kernel_oplocks);
239 DEBUG(0,("Linux Kernel oplocks talloc_Zero failed\n"));
243 ctx->ops = &linux_koplocks;
244 ctx->private_data = sconn;
246 se = tevent_add_signal(sconn->ev_ctx,
248 RT_SIGNAL_LEASE, SA_SIGINFO,
249 linux_oplock_signal_handler,
252 DEBUG(0,("Failed to setup RT_SIGNAL_LEASE handler"));
257 DEBUG(3,("Linux kernel oplocks enabled\n"));
262 void oplock_linux_dummy(void);
264 void oplock_linux_dummy(void) {}
265 #endif /* HAVE_KERNEL_OPLOCKS_LINUX */