From 9e1c873a9e5034244a58940ebd32c7ba0f6b9e01 Mon Sep 17 00:00:00 2001
From: Volker Lendecke <vl@samba.org>
Date: Mon, 9 Jul 2012 11:10:30 +0200
Subject: s3: Convert aio_fork to pread/pwrite_send/recv

Signed-off-by: Jeremy Allison <jra@samba.org>
---
 source3/modules/vfs_aio_fork.c | 497 +++++++++++++++--------------------------
 1 file changed, 174 insertions(+), 323 deletions(-)

(limited to 'source3')

diff --git a/source3/modules/vfs_aio_fork.c b/source3/modules/vfs_aio_fork.c
index 21a7f1df42..76153e38bc 100644
--- a/source3/modules/vfs_aio_fork.c
+++ b/source3/modules/vfs_aio_fork.c
@@ -24,7 +24,8 @@
 #include "system/shmem.h"
 #include "smbd/smbd.h"
 #include "smbd/globals.h"
-#include <aio.h>
+#include "lib/async_req/async_sock.h"
+#include "lib/util/tevent_unix.h"
 
 #ifndef MAP_FILE
 #define MAP_FILE 0
@@ -94,17 +95,11 @@ struct aio_child_list;
 struct aio_child {
 	struct aio_child *prev, *next;
 	struct aio_child_list *list;
-	SMB_STRUCT_AIOCB *aiocb;
 	pid_t pid;
 	int sockfd;
-	struct fd_event *sock_event;
-	struct rw_ret retval;
-	struct mmap_area *map;	/* ==NULL means write request */
+	struct mmap_area *map;
 	bool dont_delete;	/* Marked as in use since last cleanup */
-	bool cancelled;
-	bool read_cmd;
-	bool called_from_suspend;
-	bool completion_done;
+	bool busy;
 };
 
 struct aio_child_list {
@@ -241,7 +236,7 @@ static void aio_child_cleanup(struct event_context *event_ctx,
 	for (child = list->children; child != NULL; child = next) {
 		next = child->next;
 
-		if (child->aiocb != NULL) {
+		if (child->busy) {
 			DEBUG(10, ("child %d currently active\n",
 				   (int)child->pid));
 			continue;
@@ -395,62 +390,11 @@ static void aio_child_loop(int sockfd, struct mmap_area *map)
 	}
 }
 
-static void handle_aio_completion(struct event_context *event_ctx,
-				  struct fd_event *event, uint16 flags,
-				  void *p)
-{
-	struct aio_extra *aio_ex = NULL;
-	struct aio_child *child = (struct aio_child *)p;
-	NTSTATUS status;
-
-	DEBUG(10, ("handle_aio_completion called with flags=%d\n", flags));
-
-	if ((flags & EVENT_FD_READ) == 0) {
-		return;
-	}
-
-	status = read_data(child->sockfd, (char *)&child->retval,
-			   sizeof(child->retval));
-
-	if (!NT_STATUS_IS_OK(status)) {
-		DEBUG(1, ("aio child %d died: %s\n", (int)child->pid,
-			  nt_errstr(status)));
-		child->retval.size = -1;
-		child->retval.ret_errno = EIO;
-	}
-
-	if (child->aiocb == NULL) {
-		DEBUG(1, ("Inactive child died\n"));
-		TALLOC_FREE(child);
-		return;
-	}
-
-	if (child->cancelled) {
-		child->aiocb = NULL;
-		child->cancelled = false;
-		return;
-	}
-
-	if (child->read_cmd && (child->retval.size > 0)) {
-		SMB_ASSERT(child->retval.size <= child->aiocb->aio_nbytes);
-		memcpy((void *)child->aiocb->aio_buf, (void *)child->map->ptr,
-		       child->retval.size);
-	}
-
-	if (child->called_from_suspend) {
-		child->completion_done = true;
-		return;
-	}
-	aio_ex = (struct aio_extra *)child->aiocb->aio_sigevent.sigev_value.sival_ptr;
-	smbd_aio_complete_aio_ex(aio_ex);
-	TALLOC_FREE(aio_ex);
-}
-
 static int aio_child_destructor(struct aio_child *child)
 {
 	char c=0;
 
-	SMB_ASSERT((child->aiocb == NULL) || child->cancelled);
+	SMB_ASSERT(!child->busy);
 
 	DEBUG(10, ("aio_child_destructor: removing child %d on fd %d\n",
 			child->pid, child->sockfd));
@@ -531,16 +475,6 @@ static int create_aio_child(struct smbd_server_connection *sconn,
 	result->sockfd = fdpair[0];
 	close(fdpair[1]);
 
-	result->sock_event = event_add_fd(server_event_context(), result,
-					  result->sockfd, EVENT_FD_READ,
-					  handle_aio_completion,
-					  result);
-	if (result->sock_event == NULL) {
-		ret = ENOMEM;
-		DEBUG(0, ("event_add_fd failed\n"));
-		goto fail;
-	}
-
 	result->list = children;
 	DLIST_ADD(children->children, result);
 
@@ -570,8 +504,7 @@ static int get_idle_child(struct vfs_handle_struct *handle,
 	}
 
 	for (child = children->children; child != NULL; child = child->next) {
-		if (child->aiocb == NULL) {
-			/* idle */
+		if (!child->busy) {
 			break;
 		}
 	}
@@ -591,314 +524,234 @@ static int get_idle_child(struct vfs_handle_struct *handle,
 	}
 
 	child->dont_delete = true;
+	child->busy = true;
 
 	*pchild = child;
 	return 0;
 }
 
-static int aio_fork_read(struct vfs_handle_struct *handle,
-			 struct files_struct *fsp, SMB_STRUCT_AIOCB *aiocb)
-{
+struct aio_fork_pread_state {
 	struct aio_child *child;
-	struct rw_cmd cmd;
 	ssize_t ret;
 	int err;
+};
 
-	if (aiocb->aio_nbytes > 128*1024) {
-		/* TODO: support variable buffers */
-		errno = EINVAL;
-		return -1;
-	}
-
-	err = get_idle_child(handle, &child);
-	if (err != 0) {
-		DEBUG(10, ("Could not get an idle child: %s\n",
-			   strerror(err)));
-		errno = err;
-		return -1;
-	}
-
-	child->read_cmd = true;
-	child->aiocb = aiocb;
-	child->retval.ret_errno = EINPROGRESS;
-
-	ZERO_STRUCT(cmd);
-	cmd.n = aiocb->aio_nbytes;
-	cmd.offset = aiocb->aio_offset;
-	cmd.read_cmd = child->read_cmd;
-
-	DEBUG(10, ("sending fd %d to child %d\n", fsp->fh->fd,
-		   (int)child->pid));
-
-	ret = write_fd(child->sockfd, &cmd, sizeof(cmd), fsp->fh->fd);
-	if (ret == -1) {
-		DEBUG(10, ("write_fd failed: %s\n", strerror(errno)));
-		return -1;
-	}
-
-	return 0;
-}
+static void aio_fork_pread_done(struct tevent_req *subreq);
 
-static int aio_fork_write(struct vfs_handle_struct *handle,
-			  struct files_struct *fsp, SMB_STRUCT_AIOCB *aiocb)
+static struct tevent_req *aio_fork_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 aio_child *child;
+	struct tevent_req *req, *subreq;
+	struct aio_fork_pread_state *state;
 	struct rw_cmd cmd;
-	ssize_t ret;
+	ssize_t written;
 	int err;
 
-	if (aiocb->aio_nbytes > 128*1024) {
+	req = tevent_req_create(mem_ctx, &state, struct aio_fork_pread_state);
+	if (req == NULL) {
+		return NULL;
+	}
+
+	if (n > 128*1024) {
 		/* TODO: support variable buffers */
-		errno = EINVAL;
-		return -1;
+		tevent_req_error(req, EINVAL);
+		return tevent_req_post(req, ev);
 	}
 
-	err = get_idle_child(handle, &child);
+	err = get_idle_child(handle, &state->child);
 	if (err != 0) {
-		DEBUG(10, ("Could not get an idle child: %s\n",
-			   strerror(err)));
-		errno = err;
-		return -1;
+		tevent_req_error(req, err);
+		return tevent_req_post(req, ev);
 	}
 
-	child->read_cmd = false;
-	child->aiocb = aiocb;
-	child->retval.ret_errno = EINPROGRESS;
-
-	memcpy((void *)child->map->ptr, (void *)aiocb->aio_buf,
-	       aiocb->aio_nbytes);
-
 	ZERO_STRUCT(cmd);
-	cmd.n = aiocb->aio_nbytes;
-	cmd.offset = aiocb->aio_offset;
-	cmd.read_cmd = child->read_cmd;
+	cmd.n = n;
+	cmd.offset = offset;
+	cmd.read_cmd = true;
 
 	DEBUG(10, ("sending fd %d to child %d\n", fsp->fh->fd,
-		   (int)child->pid));
+		   (int)state->child->pid));
 
-	ret = write_fd(child->sockfd, &cmd, sizeof(cmd), fsp->fh->fd);
-	if (ret == -1) {
-		DEBUG(10, ("write_fd failed: %s\n", strerror(errno)));
-		return -1;
+	/*
+	 * Not making this async. We're writing into an empty unix
+	 * domain socket. This should never block.
+	 */
+	written = write_fd(state->child->sockfd, &cmd, sizeof(cmd),
+			   fsp->fh->fd);
+	if (written == -1) {
+		err = errno;
+
+		TALLOC_FREE(state->child);
+
+		DEBUG(10, ("write_fd failed: %s\n", strerror(err)));
+		tevent_req_error(req, err);
+		return tevent_req_post(req, ev);
 	}
 
-	return 0;
+	subreq = read_packet_send(state, ev, state->child->sockfd,
+				  sizeof(struct rw_ret), NULL, NULL);
+	if (tevent_req_nomem(subreq, req)) {
+		TALLOC_FREE(state->child); /* we sent sth down */
+		return tevent_req_post(req, ev);
+	}
+	tevent_req_set_callback(subreq, aio_fork_pread_done, req);
+	return req;
 }
 
-static struct aio_child *aio_fork_find_child(struct vfs_handle_struct *handle,
-					     SMB_STRUCT_AIOCB *aiocb)
+static void aio_fork_pread_done(struct tevent_req *subreq)
 {
-	struct aio_child_list *children;
-	struct aio_child *child;
+	struct tevent_req *req = tevent_req_callback_data(
+		subreq, struct tevent_req);
+	struct aio_fork_pread_state *state = tevent_req_data(
+		req, struct aio_fork_pread_state);
+	ssize_t nread;
+	uint8_t *buf;
+	int err;
+	struct rw_ret *retbuf;
 
-	children = init_aio_children(handle);
-	if (children == NULL) {
-		return NULL;
+	nread = read_packet_recv(subreq, talloc_tos(), &buf, &err);
+	TALLOC_FREE(subreq);
+	if (nread == -1) {
+		TALLOC_FREE(state->child);
+		tevent_req_error(req, err);
+		return;
 	}
 
-	for (child = children->children; child != NULL; child = child->next) {
-		if (child->aiocb == aiocb) {
-			return child;
-		}
-	}
+	state->child->busy = false;
 
-	return NULL;
+	retbuf = (struct rw_ret *)buf;
+	state->ret = retbuf->size;
+	state->err = retbuf->ret_errno;
+	tevent_req_done(req);
 }
 
-static ssize_t aio_fork_return_fn(struct vfs_handle_struct *handle,
-				  struct files_struct *fsp,
-				  SMB_STRUCT_AIOCB *aiocb)
+static ssize_t aio_fork_pread_recv(struct tevent_req *req, int *err)
 {
-	struct aio_child *child = aio_fork_find_child(handle, aiocb);
+	struct aio_fork_pread_state *state = tevent_req_data(
+		req, struct aio_fork_pread_state);
 
-	if (child == NULL) {
-		errno = EINVAL;
-		DEBUG(0, ("returning EINVAL\n"));
+	if (tevent_req_is_unix_error(req, err)) {
 		return -1;
 	}
-
-	child->aiocb = NULL;
-
-	if (child->cancelled) {
-		errno = ECANCELED;
-		return -1;
+	if (state->ret == -1) {
+		*err = state->err;
 	}
+	return state->ret;
+}
 
-	if (child->retval.size == -1) {
-		errno = child->retval.ret_errno;
-	}
+struct aio_fork_pwrite_state {
+	struct aio_child *child;
+	ssize_t ret;
+	int err;
+};
 
-	return child->retval.size;
-}
+static void aio_fork_pwrite_done(struct tevent_req *subreq);
 
-static int aio_fork_cancel(struct vfs_handle_struct *handle,
-			   struct files_struct *fsp,
-			   SMB_STRUCT_AIOCB *aiocb)
+static struct tevent_req *aio_fork_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 aio_child_list *children;
-	struct aio_child *child;
+	struct tevent_req *req, *subreq;
+	struct aio_fork_pwrite_state *state;
+	struct rw_cmd cmd;
+	ssize_t written;
+	int err;
 
-	children = init_aio_children(handle);
-	if (children == NULL) {
-		errno = EINVAL;
-		return -1;
+	req = tevent_req_create(mem_ctx, &state, struct aio_fork_pwrite_state);
+	if (req == NULL) {
+		return NULL;
 	}
 
-	for (child = children->children; child != NULL; child = child->next) {
-		if (child->aiocb == NULL) {
-			continue;
-		}
-		if (child->aiocb->aio_fildes != fsp->fh->fd) {
-			continue;
-		}
-		if ((aiocb != NULL) && (child->aiocb != aiocb)) {
-			continue;
-		}
-
-		/*
-		 * We let the child do its job, but we discard the result when
-		 * it's finished.
-		 */
+	if (n > 128*1024) {
+		/* TODO: support variable buffers */
+		tevent_req_error(req, EINVAL);
+		return tevent_req_post(req, ev);
+	}
 
-		child->cancelled = true;
+	err = get_idle_child(handle, &state->child);
+	if (err != 0) {
+		tevent_req_error(req, err);
+		return tevent_req_post(req, ev);
 	}
 
-	return AIO_CANCELED;
-}
+	ZERO_STRUCT(cmd);
+	cmd.n = n;
+	cmd.offset = offset;
+	cmd.read_cmd = false;
 
-static int aio_fork_error_fn(struct vfs_handle_struct *handle,
-			     struct files_struct *fsp,
-			     SMB_STRUCT_AIOCB *aiocb)
-{
-	struct aio_child *child = aio_fork_find_child(handle, aiocb);
+	DEBUG(10, ("sending fd %d to child %d\n", fsp->fh->fd,
+		   (int)state->child->pid));
 
-	if (child == NULL) {
-		errno = EINVAL;
-		return -1;
-	}
+	/*
+	 * Not making this async. We're writing into an empty unix
+	 * domain socket. This should never block.
+	 */
+	written = write_fd(state->child->sockfd, &cmd, sizeof(cmd),
+			   fsp->fh->fd);
+	if (written == -1) {
+		err = errno;
 
-	return child->retval.ret_errno;
-}
+		TALLOC_FREE(state->child);
 
-static void aio_fork_suspend_timed_out(struct tevent_context *event_ctx,
-					struct tevent_timer *te,
-					struct timeval now,
-					void *private_data)
-{
-	bool *timed_out = (bool *)private_data;
-	/* Remove this timed event handler. */
-	TALLOC_FREE(te);
-	*timed_out = true;
+		DEBUG(10, ("write_fd failed: %s\n", strerror(err)));
+		tevent_req_error(req, err);
+		return tevent_req_post(req, ev);
+	}
+
+	subreq = read_packet_send(state, ev, state->child->sockfd,
+				  sizeof(struct rw_ret), NULL, NULL);
+	if (tevent_req_nomem(subreq, req)) {
+		TALLOC_FREE(state->child); /* we sent sth down */
+		return tevent_req_post(req, ev);
+	}
+	tevent_req_set_callback(subreq, aio_fork_pwrite_done, req);
+	return req;
 }
 
-static int aio_fork_suspend(struct vfs_handle_struct *handle,
-			struct files_struct *fsp,
-			const SMB_STRUCT_AIOCB * const aiocb_array[],
-			int n,
-			const struct timespec *timeout)
+static void aio_fork_pwrite_done(struct tevent_req *subreq)
 {
-	struct aio_child_list *children = NULL;
-	TALLOC_CTX *frame = talloc_stackframe();
-	struct event_context *ev = NULL;
-	int i;
-	int ret = -1;
-	bool timed_out = false;
+	struct tevent_req *req = tevent_req_callback_data(
+		subreq, struct tevent_req);
+	struct aio_fork_pwrite_state *state = tevent_req_data(
+		req, struct aio_fork_pwrite_state);
+	ssize_t nread;
+	uint8_t *buf;
 	int err;
+	struct rw_ret *retbuf;
 
-	children = init_aio_children(handle);
-	if (children == NULL) {
-		errno = EINVAL;
-		goto out;
-	}
-
-	/* This is a blocking call, and has to use a sub-event loop. */
-	ev = event_context_init(frame);
-	if (ev == NULL) {
-		errno = ENOMEM;
-		goto out;
-	}
-
-	if (timeout) {
-		struct timeval tv = convert_timespec_to_timeval(*timeout);
-		struct tevent_timer *te = tevent_add_timer(ev,
-						frame,
-						timeval_current_ofs(tv.tv_sec,
-								    tv.tv_usec),
-						aio_fork_suspend_timed_out,
-						&timed_out);
-		if (!te) {
-			errno = ENOMEM;
-			goto out;
-		}
+	nread = read_packet_recv(subreq, talloc_tos(), &buf, &err);
+	TALLOC_FREE(subreq);
+	if (nread == -1) {
+		TALLOC_FREE(state->child);
+		tevent_req_error(req, err);
+		return;
 	}
 
-	for (i = 0; i < n; i++) {
-		struct aio_child *child = NULL;
-		const SMB_STRUCT_AIOCB *aiocb = aiocb_array[i];
+	state->child->busy = false;
 
-		if (!aiocb) {
-			continue;
-		}
+	retbuf = (struct rw_ret *)buf;
+	state->ret = retbuf->size;
+	state->err = retbuf->ret_errno;
+	tevent_req_done(req);
+}
 
-		/*
-		 * We're going to cheat here. We know that smbd/aio.c
-		 * only calls this when it's waiting for every single
-		 * outstanding call to finish on a close, so just wait
-		 * individually for each IO to complete. We don't care
-		 * what order they finish - only that they all do. JRA.
-		 */
+static ssize_t aio_fork_pwrite_recv(struct tevent_req *req, int *err)
+{
+	struct aio_fork_pwrite_state *state = tevent_req_data(
+		req, struct aio_fork_pwrite_state);
 
-		for (child = children->children; child != NULL; child = child->next) {
-			struct tevent_fd *event;
-
-			if (child->aiocb == NULL) {
-				continue;
-			}
-			if (child->aiocb->aio_fildes != fsp->fh->fd) {
-				continue;
-			}
-			if (child->aiocb != aiocb) {
-				continue;
-			}
-
-			if (child->aiocb->aio_sigevent.sigev_value.sival_ptr == NULL) {
-				continue;
-			}
-
-			event = event_add_fd(ev,
-					     frame,
-					     child->sockfd,
-					     EVENT_FD_READ,
-					     handle_aio_completion,
-					     child);
-			if (event == NULL) {
-				errno = ENOMEM;
-				goto out;
-			}
-
-			child->called_from_suspend = true;
-
-			while (!child->completion_done) {
-				if (tevent_loop_once(ev) == -1) {
-					goto out;
-				}
-
-				if (timed_out) {
-					errno = EAGAIN;
-					goto out;
-				}
-			}
-		}
+	if (tevent_req_is_unix_error(req, err)) {
+		return -1;
 	}
-
-	ret = 0;
-
-  out:
-
-	err = errno;
-	TALLOC_FREE(frame);
-	errno = err;
-	return ret;
+	if (state->ret == -1) {
+		*err = state->err;
+	}
+	return state->ret;
 }
 
 static int aio_fork_connect(vfs_handle_struct *handle, const char *service,
@@ -920,12 +773,10 @@ static int aio_fork_connect(vfs_handle_struct *handle, const char *service,
 
 static struct vfs_fn_pointers vfs_aio_fork_fns = {
 	.connect_fn = aio_fork_connect,
-	.aio_read_fn = aio_fork_read,
-	.aio_write_fn = aio_fork_write,
-	.aio_return_fn = aio_fork_return_fn,
-	.aio_cancel_fn = aio_fork_cancel,
-	.aio_error_fn = aio_fork_error_fn,
-	.aio_suspend_fn = aio_fork_suspend,
+	.pread_send_fn = aio_fork_pread_send,
+	.pread_recv_fn = aio_fork_pread_recv,
+	.pwrite_send_fn = aio_fork_pwrite_send,
+	.pwrite_recv_fn = aio_fork_pwrite_recv,
 };
 
 NTSTATUS vfs_aio_fork_init(void);
-- 
cgit