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 * Call to set the kernel lease signal handler
51 int linux_set_lease_sighandler(int fd)
53 if (fcntl(fd, F_SETSIG, RT_SIGNAL_LEASE) == -1) {
54 DEBUG(3,("Failed to set signal handler for kernel lease\n"));
61 /****************************************************************************
62 Call SETLEASE. If we get EACCES then we try setting up the right capability and
64 Use the SMB_VFS_LINUX_SETLEASE instead of this call directly.
65 ****************************************************************************/
67 int linux_setlease(int fd, int leasetype)
73 * Ensure the lease owner is root to allow
74 * correct delivery of lease-break signals.
79 /* First set the signal handler. */
80 if (linux_set_lease_sighandler(fd) == -1) {
85 ret = fcntl(fd, F_SETLEASE, leasetype);
100 /****************************************************************************
101 * Deal with the Linux kernel <--> smbd
102 * oplock break protocol.
103 ****************************************************************************/
105 static void linux_oplock_signal_handler(struct tevent_context *ev_ctx,
106 struct tevent_signal *se,
107 int signum, int count,
108 void *_info, void *private_data)
110 struct kernel_oplocks *ctx =
111 talloc_get_type_abort(private_data,
112 struct kernel_oplocks);
113 struct smbd_server_connection *sconn =
114 talloc_get_type_abort(ctx->private_data,
115 struct smbd_server_connection);
116 siginfo_t *info = (siginfo_t *)_info;
117 int fd = info->si_fd;
120 fsp = file_find_fd(sconn, fd);
122 DEBUG(0,("linux_oplock_signal_handler: failed to find fsp for file fd=%d (file was closed ?)\n", fd ));
125 break_kernel_oplock(sconn->msg_ctx, fsp);
128 /****************************************************************************
129 Attempt to set an kernel oplock on a file.
130 ****************************************************************************/
132 static bool linux_set_kernel_oplock(struct kernel_oplocks *ctx,
133 files_struct *fsp, int oplock_type)
135 struct file_id_buf idbuf;
137 if ( SMB_VFS_LINUX_SETLEASE(fsp, F_WRLCK) == -1) {
138 DBG_NOTICE("Refused oplock on file %s, "
139 "fd = %d, file_id = %s. (%s)\n",
142 file_id_str_buf(fsp->file_id, &idbuf),
147 DBG_NOTICE("got kernel oplock on file %s, "
148 "file_id = %s gen_id = %"PRIu64"\n",
150 file_id_str_buf(fsp->file_id, &idbuf),
156 /****************************************************************************
157 Release a kernel oplock on a file.
158 ****************************************************************************/
160 static void linux_release_kernel_oplock(struct kernel_oplocks *ctx,
161 files_struct *fsp, int oplock_type)
163 struct file_id_buf idbuf;
167 * Check and print out the current kernel
168 * oplock state of this file.
170 int state = fcntl(fsp->fh->fd, F_GETLEASE, 0);
171 dbgtext("linux_release_kernel_oplock: file %s, file_id = %s "
172 "gen_id = %"PRIu64" has kernel oplock state "
175 file_id_str_buf(fsp->file_id, &idbuf),
181 * Remove the kernel oplock on this file.
183 if ( SMB_VFS_LINUX_SETLEASE(fsp, F_UNLCK) == -1) {
185 dbgtext("linux_release_kernel_oplock: Error when "
186 "removing kernel oplock on file " );
187 dbgtext("%s, file_id = %s, gen_id = %"PRIu64". "
190 file_id_str_buf(fsp->file_id, &idbuf),
197 /****************************************************************************
198 See if the kernel supports oplocks.
199 ****************************************************************************/
201 static bool linux_oplocks_available(void)
204 fd = open("/dev/null", O_RDONLY);
206 return False; /* uggh! */
207 ret = fcntl(fd, F_GETLEASE, 0);
209 return ret == F_UNLCK;
212 /****************************************************************************
213 Setup kernel oplocks.
214 ****************************************************************************/
216 static const struct kernel_oplocks_ops linux_koplocks = {
217 .set_oplock = linux_set_kernel_oplock,
218 .release_oplock = linux_release_kernel_oplock,
221 struct kernel_oplocks *linux_init_kernel_oplocks(struct smbd_server_connection *sconn)
223 struct kernel_oplocks *ctx;
224 struct tevent_signal *se;
226 if (!linux_oplocks_available()) {
227 DEBUG(3,("Linux kernel oplocks not available\n"));
231 ctx = talloc_zero(sconn, struct kernel_oplocks);
233 DEBUG(0,("Linux Kernel oplocks talloc_Zero failed\n"));
237 ctx->ops = &linux_koplocks;
238 ctx->private_data = sconn;
240 se = tevent_add_signal(sconn->ev_ctx,
242 RT_SIGNAL_LEASE, SA_SIGINFO,
243 linux_oplock_signal_handler,
246 DEBUG(0,("Failed to setup RT_SIGNAL_LEASE handler"));
251 DEBUG(3,("Linux kernel oplocks enabled\n"));
256 void oplock_linux_dummy(void);
258 void oplock_linux_dummy(void) {}
259 #endif /* HAVE_KERNEL_OPLOCKS_LINUX */