--- /dev/null
+/*
+ * Simulate pread_send/recv and pwrite_send/recv using posix aio
+ *
+ * Copyright (C) Volker Lendecke 2012
+ *
+ * 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, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "includes.h"
+#include "system/filesys.h"
+#include "system/shmem.h"
+#include "smbd/smbd.h"
+#include "smbd/globals.h"
+#include "lib/util/tevent_unix.h"
+#include <aio.h>
+
+/* The signal we'll use to signify aio done. */
+#ifndef RT_SIGNAL_AIO
+#define RT_SIGNAL_AIO (SIGRTMIN+3)
+#endif
+
+#ifndef HAVE_STRUCT_SIGEVENT_SIGEV_VALUE_SIVAL_PTR
+#ifdef HAVE_STRUCT_SIGEVENT_SIGEV_VALUE_SIGVAL_PTR
+#define sival_int sigval_int
+#define sival_ptr sigval_ptr
+#endif
+#endif
+
+static struct tevent_signal *aio_signal_event = NULL;
+
+struct aio_posix_state {
+ struct aiocb acb;
+ ssize_t ret;
+ int err;
+};
+
+static int aio_posix_state_destructor(struct aio_posix_state *s)
+{
+ int ret;
+
+ /*
+ * We could do better here. This destructor is run when a
+ * request is prematurely cancelled. We wait for the aio to
+ * complete, so that we do not have to maintain aiocb structs
+ * beyond the life of an aio_posix_state. Possible, but not
+ * sure the effort is worth it right now.
+ */
+
+ do {
+ const struct aiocb *a = &s->acb;
+ ret = aio_suspend(&a, 1, NULL);
+ } while ((ret == -1) && (errno == EINTR));
+
+ return 0;
+}
+
+static struct tevent_req *aio_posix_pread_send(
+ struct vfs_handle_struct *handle,
+ TALLOC_CTX *mem_ctx, struct tevent_context *ev,
+ struct files_struct *fsp, void *data, size_t n, off_t offset)
+{
+ struct tevent_req *req;
+ struct aio_posix_state *state;
+ struct aiocb *a;
+ int ret;
+
+ req = tevent_req_create(mem_ctx, &state, struct aio_posix_state);
+ if (req == NULL) {
+ return NULL;
+ }
+
+ a = &state->acb;
+
+ a->aio_fildes = fsp->fh->fd;
+ a->aio_buf = data;
+ a->aio_nbytes = n;
+ a->aio_offset = offset;
+ a->aio_sigevent.sigev_notify = SIGEV_SIGNAL;
+ a->aio_sigevent.sigev_signo = RT_SIGNAL_AIO;
+ a->aio_sigevent.sigev_value.sival_ptr = req;
+
+ ret = aio_read(a);
+ if (ret == 0) {
+ talloc_set_destructor(state, aio_posix_state_destructor);
+ return req;
+ }
+
+ if (errno == EAGAIN) {
+ /*
+ * aio overloaded, do the sync fallback
+ */
+ state->ret = sys_pread(fsp->fh->fd, data, n, offset);
+ if (state->ret == -1) {
+ state->err = errno;
+ }
+ tevent_req_done(req);
+ return tevent_req_post(req, ev);
+ }
+
+ tevent_req_error(req, errno);
+ return tevent_req_post(req, ev);
+}
+
+static struct tevent_req *aio_posix_pwrite_send(
+ struct vfs_handle_struct *handle,
+ TALLOC_CTX *mem_ctx, struct tevent_context *ev,
+ struct files_struct *fsp, const void *data, size_t n, off_t offset)
+{
+ struct tevent_req *req;
+ struct aio_posix_state *state;
+ struct aiocb *a;
+ int ret;
+
+ req = tevent_req_create(mem_ctx, &state, struct aio_posix_state);
+ if (req == NULL) {
+ return NULL;
+ }
+
+ a = &state->acb;
+
+ a->aio_fildes = fsp->fh->fd;
+ a->aio_buf = discard_const(data);
+ a->aio_nbytes = n;
+ a->aio_offset = offset;
+ a->aio_sigevent.sigev_notify = SIGEV_SIGNAL;
+ a->aio_sigevent.sigev_signo = RT_SIGNAL_AIO;
+ a->aio_sigevent.sigev_value.sival_ptr = req;
+
+ ret = aio_write(a);
+ if (ret == 0) {
+ talloc_set_destructor(state, aio_posix_state_destructor);
+ return req;
+ }
+
+ if (errno == EAGAIN) {
+ /*
+ * aio overloaded, do the sync fallback
+ */
+ state->ret = sys_pwrite(fsp->fh->fd, data, n, offset);
+ if (state->ret == -1) {
+ state->err = errno;
+ }
+ tevent_req_done(req);
+ return tevent_req_post(req, ev);
+ }
+
+ tevent_req_error(req, errno);
+ return tevent_req_post(req, ev);
+}
+
+static void aio_posix_signal_handler(struct tevent_context *ev,
+ struct tevent_signal *se,
+ int signum, int count,
+ void *_info, void *private_data)
+{
+ siginfo_t *info;
+ struct tevent_req *req;
+ struct aio_posix_state *state;
+ int err;
+
+ info = (siginfo_t *)_info;
+ req = talloc_get_type_abort(info->si_value.sival_ptr,
+ struct tevent_req);
+ state = tevent_req_data(req, struct aio_posix_state);
+
+ err = aio_error(&state->acb);
+ if (err == EINPROGRESS) {
+ DEBUG(10, ("aio_posix_signal_handler: operation req %p "
+ "still in progress\n", req));
+ return;
+ }
+ if (err == ECANCELED) {
+ DEBUG(10, ("aio_posix_signal_handler: operation req %p "
+ "canceled\n", req));
+ return;
+ }
+
+ /*
+ * No need to suspend for this in the destructor anymore
+ */
+ talloc_set_destructor(state, NULL);
+
+ state->ret = aio_return(&state->acb);
+ state->err = err;
+ tevent_req_done(req);
+}
+
+static ssize_t aio_posix_recv(struct tevent_req *req, int *err)
+{
+ struct aio_posix_state *state = tevent_req_data(
+ req, struct aio_posix_state);
+
+ if (tevent_req_is_unix_error(req, err)) {
+ return -1;
+ }
+ *err = state->err;
+ return state->ret;
+}
+
+static int aio_posix_connect(vfs_handle_struct *handle, const char *service,
+ const char *user)
+{
+ if (aio_signal_event == NULL) {
+ struct tevent_context *ev = handle->conn->sconn->ev_ctx;
+
+ aio_signal_event = tevent_add_signal(
+ ev, ev, RT_SIGNAL_AIO, SA_SIGINFO,
+ aio_posix_signal_handler, NULL);
+
+ if (aio_signal_event == NULL) {
+ DEBUG(1, ("tevent_add_signal failed\n"));
+ return -1;
+ }
+ }
+ return SMB_VFS_NEXT_CONNECT(handle, service, user);
+}
+
+static struct vfs_fn_pointers vfs_aio_posix_fns = {
+ .connect_fn = aio_posix_connect,
+ .pread_send_fn = aio_posix_pread_send,
+ .pread_recv_fn = aio_posix_recv,
+ .pwrite_send_fn = aio_posix_pwrite_send,
+ .pwrite_recv_fn = aio_posix_recv,
+};
+
+NTSTATUS vfs_aio_posix_init(void);
+NTSTATUS vfs_aio_posix_init(void)
+{
+ return smb_register_vfs(SMB_VFS_INTERFACE_VERSION,
+ "aio_posix", &vfs_aio_posix_fns);
+}
git.samba.org / rusty / samba.git / commitdiff