Unix SMB/CIFS implementation.
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 3 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, see <http://www.gnu.org/licenses/>.
*/
#define DBGC_CLASS DBGC_LOCKING
#include "includes.h"
+#include "system/filesys.h"
+#include "smbd/smbd.h"
+#include "smbd/globals.h"
#if HAVE_KERNEL_OPLOCKS_LINUX
-/* these can be removed when they are in glibc headers */
-struct cap_user_header {
- uint32 version;
- int pid;
-} header;
-struct cap_user_data {
- uint32 effective;
- uint32 permitted;
- uint32 inheritable;
-} data;
-
-extern int capget(struct cap_user_header * hdrp,
- struct cap_user_data * datap);
-extern int capset(struct cap_user_header * hdrp,
- const struct cap_user_data * datap);
-
-static SIG_ATOMIC_T signals_received;
-#define FD_PENDING_SIZE 100
-static SIG_ATOMIC_T fd_pending_array[FD_PENDING_SIZE];
-
#ifndef F_SETLEASE
#define F_SETLEASE 1024
#endif
#define F_SETSIG 10
#endif
-/****************************************************************************
- Handle a LEASE signal, incrementing the signals_received and blocking the signal.
-****************************************************************************/
-
-static void signal_handler(int sig, siginfo_t *info, void *unused)
-{
- if (signals_received < FD_PENDING_SIZE - 1) {
- fd_pending_array[signals_received] = (SIG_ATOMIC_T)info->si_fd;
- signals_received++;
- } /* Else signal is lost. */
- sys_select_signal(RT_SIGNAL_LEASE);
-}
-
-/****************************************************************************
- Try to gain a linux capability.
-****************************************************************************/
-
-static void set_capability(unsigned capability)
-{
-#ifndef _LINUX_CAPABILITY_VERSION
-#define _LINUX_CAPABILITY_VERSION 0x19980330
-#endif
- header.version = _LINUX_CAPABILITY_VERSION;
- header.pid = 0;
-
- if (capget(&header, &data) == -1) {
- DEBUG(3,("Unable to get kernel capabilities (%s)\n",
- strerror(errno)));
- return;
- }
-
- if (0 == (data.effective & (1<<capability))) {
- data.effective |= (1<<capability);
-
- if (capset(&header, &data) == -1) {
- DEBUG(3,("Unable to set %d capability (%s)\n",
- capability, strerror(errno)));
- }
- }
-}
-
/*
* public function to get linux lease capability. Needed by some VFS modules (eg. gpfs.c)
*/
void linux_set_lease_capability(void)
{
- set_capability(CAP_LEASE);
+ set_effective_capability(LEASE_CAPABILITY);
}
/*
int linux_setlease(int fd, int leasetype)
{
int ret;
+ int saved_errno;
+
+ /*
+ * Ensure the lease owner is root to allow
+ * correct delivery of lease-break signals.
+ */
+
+ become_root();
+ /* First set the signal handler. */
+ if (linux_set_lease_sighandler(fd) == -1) {
+ saved_errno = errno;
+ ret = -1;
+ goto out;
+ }
ret = fcntl(fd, F_SETLEASE, leasetype);
- if (ret == -1 && errno == EACCES) {
- set_capability(CAP_LEASE);
- ret = fcntl(fd, F_SETLEASE, leasetype);
+ if (ret == -1) {
+ saved_errno = errno;
}
+ out:
+
+ unbecome_root();
+
+ if (ret == -1) {
+ errno = saved_errno;
+ }
return ret;
}
* oplock break protocol.
****************************************************************************/
-static files_struct *linux_oplock_receive_message(fd_set *fds)
+static void linux_oplock_signal_handler(struct tevent_context *ev_ctx,
+ struct tevent_signal *se,
+ int signum, int count,
+ void *_info, void *private_data)
{
- int fd;
+ struct kernel_oplocks *ctx =
+ talloc_get_type_abort(private_data,
+ struct kernel_oplocks);
+ struct smbd_server_connection *sconn =
+ talloc_get_type_abort(ctx->private_data,
+ struct smbd_server_connection);
+ siginfo_t *info = (siginfo_t *)_info;
+ int fd = info->si_fd;
files_struct *fsp;
- BlockSignals(True, RT_SIGNAL_LEASE);
- fd = fd_pending_array[0];
- fsp = file_find_fd(fd);
- fd_pending_array[0] = (SIG_ATOMIC_T)-1;
- if (signals_received > 1)
- memmove(CONST_DISCARD(void *, &fd_pending_array[0]),
- CONST_DISCARD(void *, &fd_pending_array[1]),
- sizeof(SIG_ATOMIC_T)*(signals_received-1));
- signals_received--;
- /* now we can receive more signals */
- BlockSignals(False, RT_SIGNAL_LEASE);
-
- return fsp;
+ fsp = file_find_fd(sconn, fd);
+ if (fsp == NULL) {
+ DEBUG(0,("linux_oplock_signal_handler: failed to find fsp for file fd=%d (file was closed ?)\n", fd ));
+ return;
+ }
+ break_kernel_oplock(sconn->msg_ctx, fsp);
}
/****************************************************************************
Attempt to set an kernel oplock on a file.
****************************************************************************/
-static bool linux_set_kernel_oplock(files_struct *fsp, int oplock_type)
+static bool linux_set_kernel_oplock(struct kernel_oplocks *ctx,
+ files_struct *fsp, int oplock_type)
{
if ( SMB_VFS_LINUX_SETLEASE(fsp, F_WRLCK) == -1) {
DEBUG(3,("linux_set_kernel_oplock: Refused oplock on file %s, "
"fd = %d, file_id = %s. (%s)\n",
- fsp->fsp_name, fsp->fh->fd,
+ fsp_str_dbg(fsp), fsp->fh->fd,
file_id_string_tos(&fsp->file_id),
strerror(errno)));
return False;
DEBUG(3,("linux_set_kernel_oplock: got kernel oplock on file %s, "
"file_id = %s gen_id = %lu\n",
- fsp->fsp_name, file_id_string_tos(&fsp->file_id),
+ fsp_str_dbg(fsp), file_id_string_tos(&fsp->file_id),
fsp->fh->gen_id));
return True;
Release a kernel oplock on a file.
****************************************************************************/
-static void linux_release_kernel_oplock(files_struct *fsp)
+static void linux_release_kernel_oplock(struct kernel_oplocks *ctx,
+ files_struct *fsp, int oplock_type)
{
if (DEBUGLVL(10)) {
/*
int state = fcntl(fsp->fh->fd, F_GETLEASE, 0);
dbgtext("linux_release_kernel_oplock: file %s, file_id = %s "
"gen_id = %lu has kernel oplock state "
- "of %x.\n", fsp->fsp_name, file_id_string_tos(&fsp->file_id),
+ "of %x.\n", fsp_str_dbg(fsp),
+ file_id_string_tos(&fsp->file_id),
fsp->fh->gen_id, state );
}
dbgtext("linux_release_kernel_oplock: Error when "
"removing kernel oplock on file " );
dbgtext("%s, file_id = %s, gen_id = %lu. "
- "Error was %s\n", fsp->fsp_name,
+ "Error was %s\n", fsp_str_dbg(fsp),
file_id_string_tos(&fsp->file_id),
fsp->fh->gen_id, strerror(errno) );
}
}
}
-/****************************************************************************
- See if a oplock message is waiting.
-****************************************************************************/
-
-static bool linux_oplock_msg_waiting(fd_set *fds)
-{
- return signals_received != 0;
-}
-
/****************************************************************************
See if the kernel supports oplocks.
****************************************************************************/
Setup kernel oplocks.
****************************************************************************/
-struct kernel_oplocks *linux_init_kernel_oplocks(void)
+static const struct kernel_oplocks_ops linux_koplocks = {
+ .set_oplock = linux_set_kernel_oplock,
+ .release_oplock = linux_release_kernel_oplock,
+ .contend_level2_oplocks_begin = NULL,
+ .contend_level2_oplocks_end = NULL,
+};
+
+struct kernel_oplocks *linux_init_kernel_oplocks(struct smbd_server_connection *sconn)
{
- static struct kernel_oplocks koplocks;
- struct sigaction act;
+ struct kernel_oplocks *ctx;
+ struct tevent_signal *se;
if (!linux_oplocks_available()) {
DEBUG(3,("Linux kernel oplocks not available\n"));
return NULL;
}
- ZERO_STRUCT(act);
-
- act.sa_handler = NULL;
- act.sa_sigaction = signal_handler;
- act.sa_flags = SA_SIGINFO;
- sigemptyset( &act.sa_mask );
- if (sigaction(RT_SIGNAL_LEASE, &act, NULL) != 0) {
- DEBUG(0,("Failed to setup RT_SIGNAL_LEASE handler\n"));
+ ctx = talloc_zero(sconn, struct kernel_oplocks);
+ if (!ctx) {
+ DEBUG(0,("Linux Kernel oplocks talloc_Zero failed\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.msg_waiting = linux_oplock_msg_waiting;
- koplocks.notification_fd = -1;
-
- /* the signal can start off blocked due to a bug in bash */
- BlockSignals(False, RT_SIGNAL_LEASE);
+ ctx->ops = &linux_koplocks;
+ ctx->private_data = sconn;
+
+ se = tevent_add_signal(sconn->ev_ctx,
+ ctx,
+ RT_SIGNAL_LEASE, SA_SIGINFO,
+ linux_oplock_signal_handler,
+ ctx);
+ if (!se) {
+ DEBUG(0,("Failed to setup RT_SIGNAL_LEASE handler"));
+ TALLOC_FREE(ctx);
+ return NULL;
+ }
DEBUG(3,("Linux kernel oplocks enabled\n"));
- return &koplocks;
+ return ctx;
}
#else
void oplock_linux_dummy(void);
git.samba.org / sfrench / samba-autobuild / .git / blobdiff