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/*
Unix SMB/CIFS implementation.
Copyright (C) Stefan Metzmacher 2008
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/>.
*/
/*
lease (oplock) implementation using fcntl F_SETLEASE on linux
*/
#include "includes.h"
#include <tevent.h>
#include "system/filesys.h"
#include "ntvfs/sysdep/sys_lease.h"
#include "ntvfs/ntvfs.h"
#include "librpc/gen_ndr/ndr_opendb.h"
#include "../lib/util/dlinklist.h"
#include "cluster/cluster.h"
#define LINUX_LEASE_RT_SIGNAL (SIGRTMIN+1)
struct linux_lease_pending {
struct linux_lease_pending *prev, *next;
struct sys_lease_context *ctx;
struct opendb_entry e;
};
/* the global linked list of pending leases */
static struct linux_lease_pending *leases;
static void linux_lease_signal_handler(struct tevent_context *ev_ctx,
struct tevent_signal *se,
int signum, int count,
void *_info, void *private_data)
{
struct sys_lease_context *ctx = talloc_get_type(private_data,
struct sys_lease_context);
siginfo_t *info = (siginfo_t *)_info;
struct linux_lease_pending *c;
int got_fd = info->si_fd;
for (c = leases; c; c = c->next) {
int *fd = (int *)c->e.fd;
if (got_fd == *fd) {
break;
}
}
if (!c) {
return;
}
ctx->break_send(ctx->msg_ctx, &c->e, OPLOCK_BREAK_TO_NONE);
}
static int linux_lease_pending_destructor(struct linux_lease_pending *p)
{
int ret;
int *fd = (int *)p->e.fd;
DLIST_REMOVE(leases, p);
if (*fd == -1) {
return 0;
}
ret = fcntl(*fd, F_SETLEASE, F_UNLCK);
if (ret == -1) {
DEBUG(0,("%s: failed to remove oplock: %s\n",
__FUNCTION__, strerror(errno)));
}
return 0;
}
static NTSTATUS linux_lease_init(struct sys_lease_context *ctx)
{
struct tevent_signal *se;
se = tevent_add_signal(ctx->event_ctx, ctx,
LINUX_LEASE_RT_SIGNAL, SA_SIGINFO,
linux_lease_signal_handler, ctx);
NT_STATUS_HAVE_NO_MEMORY(se);
return NT_STATUS_OK;
}
static NTSTATUS linux_lease_setup(struct sys_lease_context *ctx,
struct opendb_entry *e)
{
int ret;
int *fd = (int *)e->fd;
struct linux_lease_pending *p;
if (e->oplock_level == OPLOCK_NONE) {
e->fd = NULL;
return NT_STATUS_OK;
} else if (e->oplock_level == OPLOCK_LEVEL_II) {
/*
* the linux kernel doesn't support level2 oplocks
* so fix up the granted oplock level
*/
e->oplock_level = OPLOCK_NONE;
e->allow_level_II_oplock = false;
e->fd = NULL;
return NT_STATUS_OK;
}
p = talloc(ctx, struct linux_lease_pending);
NT_STATUS_HAVE_NO_MEMORY(p);
p->ctx = ctx;
p->e = *e;
ret = fcntl(*fd, F_SETSIG, LINUX_LEASE_RT_SIGNAL);
if (ret == -1) {
talloc_free(p);
return map_nt_error_from_unix(errno);
}
ret = fcntl(*fd, F_SETLEASE, F_WRLCK);
if (ret == -1) {
talloc_free(p);
return map_nt_error_from_unix(errno);
}
DLIST_ADD(leases, p);
talloc_set_destructor(p, linux_lease_pending_destructor);
return NT_STATUS_OK;
}
static NTSTATUS linux_lease_remove(struct sys_lease_context *ctx,
struct opendb_entry *e);
static NTSTATUS linux_lease_update(struct sys_lease_context *ctx,
struct opendb_entry *e)
{
struct linux_lease_pending *c;
for (c = leases; c; c = c->next) {
if (c->e.fd == e->fd) {
break;
}
}
if (!c) {
return NT_STATUS_OBJECT_NAME_NOT_FOUND;
}
/*
* set the fd pointer to NULL so that the caller
* will not call the remove function as the oplock
* is already removed
*/
e->fd = NULL;
talloc_free(c);
return NT_STATUS_OK;
}
static NTSTATUS linux_lease_remove(struct sys_lease_context *ctx,
struct opendb_entry *e)
{
struct linux_lease_pending *c;
for (c = leases; c; c = c->next) {
if (c->e.fd == e->fd) {
break;
}
}
if (!c) {
return NT_STATUS_OBJECT_NAME_NOT_FOUND;
}
talloc_free(c);
return NT_STATUS_OK;
}
static struct sys_lease_ops linux_lease_ops = {
.name = "linux",
.init = linux_lease_init,
.setup = linux_lease_setup,
.update = linux_lease_update,
.remove = linux_lease_remove
};
/*
initialialise the linux lease module
*/
NTSTATUS sys_lease_linux_init(void)
{
/* register ourselves as a system lease module */
return sys_lease_register(&linux_lease_ops);
}
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