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/globals.h"
25 #if HAVE_KERNEL_OPLOCKS_LINUX
28 #define F_SETLEASE 1024
32 #define F_GETLEASE 1025
39 #ifndef RT_SIGNAL_LEASE
40 #define RT_SIGNAL_LEASE (SIGRTMIN+1)
48 * public function to get linux lease capability. Needed by some VFS modules (eg. gpfs.c)
50 void linux_set_lease_capability(void)
52 set_effective_capability(LEASE_CAPABILITY);
56 * Call to set the kernel lease signal handler
58 int linux_set_lease_sighandler(int fd)
60 if (fcntl(fd, F_SETSIG, RT_SIGNAL_LEASE) == -1) {
61 DEBUG(3,("Failed to set signal handler for kernel lease\n"));
68 /****************************************************************************
69 Call SETLEASE. If we get EACCES then we try setting up the right capability and
71 Use the SMB_VFS_LINUX_SETLEASE instead of this call directly.
72 ****************************************************************************/
74 int linux_setlease(int fd, int leasetype)
78 ret = fcntl(fd, F_SETLEASE, leasetype);
79 if (ret == -1 && errno == EACCES) {
80 set_effective_capability(LEASE_CAPABILITY);
81 ret = fcntl(fd, F_SETLEASE, leasetype);
87 /****************************************************************************
88 * Deal with the Linux kernel <--> smbd
89 * oplock break protocol.
90 ****************************************************************************/
92 static void linux_oplock_signal_handler(struct tevent_context *ev_ctx,
93 struct tevent_signal *se,
94 int signum, int count,
95 void *_info, void *private_data)
97 siginfo_t *info = (siginfo_t *)_info;
101 fsp = file_find_fd(smbd_server_conn, fd);
103 DEBUG(0,("linux_oplock_signal_handler: failed to find fsp for file fd=%d (file was closed ?)\n", fd ));
106 break_kernel_oplock(fsp->conn->sconn->msg_ctx, fsp);
109 /****************************************************************************
110 Attempt to set an kernel oplock on a file.
111 ****************************************************************************/
113 static bool linux_set_kernel_oplock(struct kernel_oplocks *ctx,
114 files_struct *fsp, int oplock_type)
116 if ( SMB_VFS_LINUX_SETLEASE(fsp, F_WRLCK) == -1) {
117 DEBUG(3,("linux_set_kernel_oplock: Refused oplock on file %s, "
118 "fd = %d, file_id = %s. (%s)\n",
119 fsp_str_dbg(fsp), fsp->fh->fd,
120 file_id_string_tos(&fsp->file_id),
125 DEBUG(3,("linux_set_kernel_oplock: got kernel oplock on file %s, "
126 "file_id = %s gen_id = %lu\n",
127 fsp_str_dbg(fsp), file_id_string_tos(&fsp->file_id),
133 /****************************************************************************
134 Release a kernel oplock on a file.
135 ****************************************************************************/
137 static void linux_release_kernel_oplock(struct kernel_oplocks *ctx,
138 files_struct *fsp, int oplock_type)
142 * Check and print out the current kernel
143 * oplock state of this file.
145 int state = fcntl(fsp->fh->fd, F_GETLEASE, 0);
146 dbgtext("linux_release_kernel_oplock: file %s, file_id = %s "
147 "gen_id = %lu has kernel oplock state "
148 "of %x.\n", fsp_str_dbg(fsp),
149 file_id_string_tos(&fsp->file_id),
150 fsp->fh->gen_id, state );
154 * Remove the kernel oplock on this file.
156 if ( SMB_VFS_LINUX_SETLEASE(fsp, F_UNLCK) == -1) {
158 dbgtext("linux_release_kernel_oplock: Error when "
159 "removing kernel oplock on file " );
160 dbgtext("%s, file_id = %s, gen_id = %lu. "
161 "Error was %s\n", fsp_str_dbg(fsp),
162 file_id_string_tos(&fsp->file_id),
163 fsp->fh->gen_id, strerror(errno) );
168 /****************************************************************************
169 See if the kernel supports oplocks.
170 ****************************************************************************/
172 static bool linux_oplocks_available(void)
175 fd = open("/dev/null", O_RDONLY);
177 return False; /* uggh! */
178 ret = fcntl(fd, F_GETLEASE, 0);
180 return ret == F_UNLCK;
183 /****************************************************************************
184 Setup kernel oplocks.
185 ****************************************************************************/
187 static const struct kernel_oplocks_ops linux_koplocks = {
188 .set_oplock = linux_set_kernel_oplock,
189 .release_oplock = linux_release_kernel_oplock,
190 .contend_level2_oplocks_begin = NULL,
191 .contend_level2_oplocks_end = NULL,
194 struct kernel_oplocks *linux_init_kernel_oplocks(TALLOC_CTX *mem_ctx)
196 struct kernel_oplocks *ctx;
197 struct tevent_signal *se;
199 if (!linux_oplocks_available()) {
200 DEBUG(3,("Linux kernel oplocks not available\n"));
204 ctx = talloc_zero(mem_ctx, struct kernel_oplocks);
206 DEBUG(0,("Linux Kernel oplocks talloc_Zero failed\n"));
210 ctx->ops = &linux_koplocks;
212 se = tevent_add_signal(smbd_event_context(),
214 RT_SIGNAL_LEASE, SA_SIGINFO,
215 linux_oplock_signal_handler,
218 DEBUG(0,("Failed to setup RT_SIGNAL_LEASE handler"));
223 ctx->private_data = se;
225 DEBUG(3,("Linux kernel oplocks enabled\n"));
230 void oplock_linux_dummy(void);
232 void oplock_linux_dummy(void) {}
233 #endif /* HAVE_KERNEL_OPLOCKS_LINUX */