--- /dev/null
+/*
+ * Simulate the Posix AIO using mmap/fork
+ *
+ * Copyright (C) Volker Lendecke 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 2 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"
+
+struct mmap_area {
+ size_t size;
+ volatile void *ptr;
+};
+
+static int mmap_area_destructor(struct mmap_area *area)
+{
+ munmap((void *)area->ptr, area->size);
+ return 0;
+}
+
+static struct mmap_area *mmap_area_init(TALLOC_CTX *mem_ctx, size_t size)
+{
+ struct mmap_area *result;
+ int fd;
+
+ result = talloc(mem_ctx, struct mmap_area);
+ if (result == NULL) {
+ DEBUG(0, ("talloc failed\n"));
+ goto fail;
+ }
+
+ fd = open("/dev/zero", O_RDWR);
+ if (fd == -1) {
+ DEBUG(3, ("open(\"/dev/zero\") failed: %s\n",
+ strerror(errno)));
+ goto fail;
+ }
+
+ result->ptr = mmap(NULL, size, PROT_READ|PROT_WRITE,
+ MAP_SHARED|MAP_FILE, fd, 0);
+ if (result->ptr == MAP_FAILED) {
+ DEBUG(1, ("mmap failed: %s\n", strerror(errno)));
+ goto fail;
+ }
+
+ result->size = size;
+ talloc_set_destructor(result, mmap_area_destructor);
+
+ return result;
+
+fail:
+ TALLOC_FREE(result);
+ return NULL;
+}
+
+struct rw_cmd {
+ size_t n;
+ SMB_OFF_T offset;
+ bool read_cmd;
+};
+
+struct rw_ret {
+ ssize_t size;
+ int ret_errno;
+};
+
+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 */
+ bool dont_delete; /* Marked as in use since last cleanup */
+ bool cancelled;
+ bool read_cmd;
+};
+
+struct aio_child_list {
+ struct aio_child *children;
+ struct timed_event *cleanup_event;
+};
+
+static void free_aio_children(void **p)
+{
+ TALLOC_FREE(*p);
+}
+
+static ssize_t read_fd(int fd, void *ptr, size_t nbytes, int *recvfd)
+{
+ struct msghdr msg;
+ struct iovec iov[1];
+ ssize_t n;
+#ifndef HAVE_MSGHDR_MSG_CONTROL
+ int newfd;
+#endif
+
+#ifdef HAVE_MSGHDR_MSG_CONTROL
+ union {
+ struct cmsghdr cm;
+ char control[CMSG_SPACE(sizeof(int))];
+ } control_un;
+ struct cmsghdr *cmptr;
+
+ msg.msg_control = control_un.control;
+ msg.msg_controllen = sizeof(control_un.control);
+#else
+#if HAVE_MSGHDR_MSG_ACCTRIGHTS
+ msg.msg_accrights = (caddr_t) &newfd;
+ msg.msg_accrightslen = sizeof(int);
+#else
+#error Can not pass file descriptors
+#endif
+#endif
+
+ msg.msg_name = NULL;
+ msg.msg_namelen = 0;
+
+ iov[0].iov_base = ptr;
+ iov[0].iov_len = nbytes;
+ msg.msg_iov = iov;
+ msg.msg_iovlen = 1;
+
+ if ( (n = recvmsg(fd, &msg, 0)) <= 0) {
+ return(n);
+ }
+
+#ifdef HAVE_MSGHDR_MSG_CONTROL
+ if ((cmptr = CMSG_FIRSTHDR(&msg)) != NULL
+ && cmptr->cmsg_len == CMSG_LEN(sizeof(int))) {
+ if (cmptr->cmsg_level != SOL_SOCKET) {
+ DEBUG(10, ("control level != SOL_SOCKET"));
+ errno = EINVAL;
+ return -1;
+ }
+ if (cmptr->cmsg_type != SCM_RIGHTS) {
+ DEBUG(10, ("control type != SCM_RIGHTS"));
+ errno = EINVAL;
+ return -1;
+ }
+ *recvfd = *((int *) CMSG_DATA(cmptr));
+ } else {
+ *recvfd = -1; /* descriptor was not passed */
+ }
+#else
+ if (msg.msg_accrightslen == sizeof(int)) {
+ *recvfd = newfd;
+ }
+ else {
+ *recvfd = -1; /* descriptor was not passed */
+ }
+#endif
+
+ return(n);
+}
+
+static ssize_t write_fd(int fd, void *ptr, size_t nbytes, int sendfd)
+{
+ struct msghdr msg;
+ struct iovec iov[1];
+
+#ifdef HAVE_MSGHDR_MSG_CONTROL
+ union {
+ struct cmsghdr cm;
+ char control[CMSG_SPACE(sizeof(int))];
+ } control_un;
+ struct cmsghdr *cmptr;
+
+ ZERO_STRUCT(msg);
+ ZERO_STRUCT(control_un);
+
+ msg.msg_control = control_un.control;
+ msg.msg_controllen = sizeof(control_un.control);
+
+ cmptr = CMSG_FIRSTHDR(&msg);
+ cmptr->cmsg_len = CMSG_LEN(sizeof(int));
+ cmptr->cmsg_level = SOL_SOCKET;
+ cmptr->cmsg_type = SCM_RIGHTS;
+ *((int *) CMSG_DATA(cmptr)) = sendfd;
+#else
+ ZERO_STRUCT(msg);
+ msg.msg_accrights = (caddr_t) &sendfd;
+ msg.msg_accrightslen = sizeof(int);
+#endif
+
+ msg.msg_name = NULL;
+ msg.msg_namelen = 0;
+
+ ZERO_STRUCT(iov);
+ iov[0].iov_base = ptr;
+ iov[0].iov_len = nbytes;
+ msg.msg_iov = iov;
+ msg.msg_iovlen = 1;
+
+ return (sendmsg(fd, &msg, 0));
+}
+
+static void aio_child_cleanup(struct event_context *event_ctx,
+ struct timed_event *te,
+ const struct timeval *now,
+ void *private_data)
+{
+ struct aio_child_list *list = talloc_get_type_abort(
+ private_data, struct aio_child_list);
+ struct aio_child *child, *next;
+
+ TALLOC_FREE(list->cleanup_event);
+
+ for (child = list->children; child != NULL; child = next) {
+ next = child->next;
+
+ if (child->aiocb != NULL) {
+ DEBUG(10, ("child %d currently active\n",
+ (int)child->pid));
+ continue;
+ }
+
+ if (child->dont_delete) {
+ DEBUG(10, ("Child %d was active since last cleanup\n",
+ (int)child->pid));
+ child->dont_delete = false;
+ continue;
+ }
+
+ DEBUG(10, ("Child %d idle for more than 30 seconds, "
+ "deleting\n", (int)child->pid));
+
+ TALLOC_FREE(child);
+ }
+
+ if (list->children != NULL) {
+ /*
+ * Re-schedule the next cleanup round
+ */
+ list->cleanup_event = event_add_timed(smbd_event_context(), list,
+ timeval_add(now, 30, 0),
+ "aio_child_cleanup",
+ aio_child_cleanup, list);
+
+ }
+}
+
+static struct aio_child_list *init_aio_children(struct vfs_handle_struct *handle)
+{
+ struct aio_child_list *data = NULL;
+
+ if (SMB_VFS_HANDLE_TEST_DATA(handle)) {
+ SMB_VFS_HANDLE_GET_DATA(handle, data, struct aio_child_list,
+ return NULL);
+ }
+
+ if (data == NULL) {
+ data = TALLOC_ZERO_P(NULL, struct aio_child_list);
+ if (data == NULL) {
+ return NULL;
+ }
+ }
+
+ /*
+ * Regardless of whether the child_list had been around or not, make
+ * sure that we have a cleanup timed event. This timed event will
+ * delete itself when it finds that no children are around anymore.
+ */
+
+ if (data->cleanup_event == NULL) {
+ data->cleanup_event = event_add_timed(smbd_event_context(), data,
+ timeval_current_ofs(30, 0),
+ "aio_child_cleanup",
+ aio_child_cleanup, data);
+ if (data->cleanup_event == NULL) {
+ TALLOC_FREE(data);
+ return NULL;
+ }
+ }
+
+ if (!SMB_VFS_HANDLE_TEST_DATA(handle)) {
+ SMB_VFS_HANDLE_SET_DATA(handle, data, free_aio_children,
+ struct aio_child_list, return False);
+ }
+
+ return data;
+}
+
+static void aio_child_loop(int sockfd, struct mmap_area *map)
+{
+ while (true) {
+ int fd = -1;
+ ssize_t ret;
+ struct rw_cmd cmd_struct;
+ struct rw_ret ret_struct;
+
+ ret = read_fd(sockfd, &cmd_struct, sizeof(cmd_struct), &fd);
+ if (ret != sizeof(cmd_struct)) {
+ DEBUG(10, ("read_fd returned %d: %s\n", (int)ret,
+ strerror(errno)));
+ exit(1);
+ }
+
+ DEBUG(10, ("aio_child_loop: %s %d bytes at %d from fd %d\n",
+ cmd_struct.read_cmd ? "read" : "write",
+ (int)cmd_struct.n, (int)cmd_struct.offset, fd));
+
+#ifdef ENABLE_BUILD_FARM_HACKS
+ {
+ /*
+ * In the build farm, we want erratic behaviour for
+ * async I/O times
+ */
+ uint8_t randval;
+ unsigned msecs;
+ /*
+ * use generate_random_buffer, we just forked from a
+ * common parent state
+ */
+ generate_random_buffer(&randval, sizeof(randval));
+ msecs = randval + 20;
+ DEBUG(10, ("delaying for %u msecs\n", msecs));
+ smb_msleep(msecs);
+ }
+#endif
+
+
+ ZERO_STRUCT(ret_struct);
+
+ if (cmd_struct.read_cmd) {
+ ret_struct.size = sys_pread(
+ fd, (void *)map->ptr, cmd_struct.n,
+ cmd_struct.offset);
+ }
+ else {
+ ret_struct.size = sys_pwrite(
+ fd, (void *)map->ptr, cmd_struct.n,
+ cmd_struct.offset);
+ }
+
+ DEBUG(10, ("aio_child_loop: syscall returned %d\n",
+ (int)ret_struct.size));
+
+ if (ret_struct.size == -1) {
+ ret_struct.ret_errno = errno;
+ }
+
+ ret = write_data(sockfd, (char *)&ret_struct,
+ sizeof(ret_struct));
+ if (ret != sizeof(ret_struct)) {
+ DEBUG(10, ("could not write ret_struct: %s\n",
+ strerror(errno)));
+ exit(2);
+ }
+
+ close(fd);
+ }
+}
+
+static void handle_aio_completion(struct event_context *event_ctx,
+ struct fd_event *event, uint16 flags,
+ void *p)
+{
+ struct aio_child *child = (struct aio_child *)p;
+ uint16 mid;
+
+ DEBUG(10, ("handle_aio_completion called with flags=%d\n", flags));
+
+ if ((flags & EVENT_FD_READ) == 0) {
+ return;
+ }
+
+ if (!NT_STATUS_IS_OK(read_data(child->sockfd,
+ (char *)&child->retval,
+ sizeof(child->retval)))) {
+ DEBUG(0, ("aio child %d died\n", (int)child->pid));
+ child->retval.size = -1;
+ child->retval.ret_errno = EIO;
+ }
+
+ 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);
+ }
+
+ mid = child->aiocb->aio_sigevent.sigev_value.sival_int;
+
+ DEBUG(10, ("mid %d finished\n", (int)mid));
+
+ aio_request_done(mid);
+ process_aio_queue();
+}
+
+static int aio_child_destructor(struct aio_child *child)
+{
+ SMB_ASSERT((child->aiocb == NULL) || child->cancelled);
+ close(child->sockfd);
+ DLIST_REMOVE(child->list->children, child);
+ return 0;
+}
+
+static NTSTATUS create_aio_child(struct aio_child_list *children,
+ size_t map_size,
+ struct aio_child **presult)
+{
+ struct aio_child *result;
+ int fdpair[2];
+ NTSTATUS status;
+
+ fdpair[0] = fdpair[1] = -1;
+
+ result = TALLOC_ZERO_P(children, struct aio_child);
+ NT_STATUS_HAVE_NO_MEMORY(result);
+
+ if (socketpair(AF_UNIX, SOCK_STREAM, 0, fdpair) == -1) {
+ status = map_nt_error_from_unix(errno);
+ DEBUG(10, ("socketpair() failed: %s\n", strerror(errno)));
+ TALLOC_FREE(result);
+ goto fail;
+ }
+
+ DEBUG(10, ("fdpair = %d/%d\n", fdpair[0], fdpair[1]));
+
+ result->map = mmap_area_init(result, map_size);
+ if (result->map == NULL) {
+ status = map_nt_error_from_unix(errno);
+ DEBUG(0, ("Could not create mmap area\n"));
+ goto fail;
+ }
+
+ result->pid = sys_fork();
+ if (result->pid == -1) {
+ status = map_nt_error_from_unix(errno);
+ DEBUG(0, ("fork failed: %s\n", strerror(errno)));
+ goto fail;
+ }
+
+ if (result->pid == 0) {
+ close(fdpair[0]);
+ result->sockfd = fdpair[1];
+ aio_child_loop(result->sockfd, result->map);
+ }
+
+ DEBUG(10, ("Child %d created\n", result->pid));
+
+ result->sockfd = fdpair[0];
+ close(fdpair[1]);
+
+ result->sock_event = event_add_fd(smbd_event_context(), result,
+ result->sockfd, EVENT_FD_READ,
+ handle_aio_completion,
+ result);
+ if (result->sock_event == NULL) {
+ status = NT_STATUS_NO_MEMORY;
+ DEBUG(0, ("event_add_fd failed\n"));
+ goto fail;
+ }
+
+ result->list = children;
+ DLIST_ADD(children->children, result);
+
+ talloc_set_destructor(result, aio_child_destructor);
+
+ *presult = result;
+
+ return NT_STATUS_OK;
+
+ fail:
+ if (fdpair[0] != -1) close(fdpair[0]);
+ if (fdpair[1] != -1) close(fdpair[1]);
+ TALLOC_FREE(result);
+
+ return status;
+}
+
+static NTSTATUS get_idle_child(struct vfs_handle_struct *handle,
+ struct aio_child **pchild)
+{
+ struct aio_child_list *children;
+ struct aio_child *child;
+ NTSTATUS status;
+
+ children = init_aio_children(handle);
+ if (children == NULL) {
+ return NT_STATUS_NO_MEMORY;
+ }
+
+ for (child = children->children; child != NULL; child = child->next) {
+ if (child->aiocb == NULL) {
+ /* idle */
+ break;
+ }
+ }
+
+ if (child == NULL) {
+ DEBUG(10, ("no idle child found, creating new one\n"));
+
+ status = create_aio_child(children, 128*1024, &child);
+ if (!NT_STATUS_IS_OK(status)) {
+ DEBUG(10, ("create_aio_child failed: %s\n",
+ nt_errstr(status)));
+ return status;
+ }
+ }
+
+ child->dont_delete = true;
+
+ *pchild = child;
+ return NT_STATUS_OK;
+}
+
+static int aio_fork_read(struct vfs_handle_struct *handle,
+ struct files_struct *fsp, SMB_STRUCT_AIOCB *aiocb)
+{
+ struct aio_child *child;
+ struct rw_cmd cmd;
+ ssize_t ret;
+ NTSTATUS status;
+
+ if (aiocb->aio_nbytes > 128*1024) {
+ /* TODO: support variable buffers */
+ errno = EINVAL;
+ return -1;
+ }
+
+ status = get_idle_child(handle, &child);
+ if (!NT_STATUS_IS_OK(status)) {
+ DEBUG(10, ("Could not get an idle child\n"));
+ 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 int aio_fork_write(struct vfs_handle_struct *handle,
+ struct files_struct *fsp, SMB_STRUCT_AIOCB *aiocb)
+{
+ struct aio_child *child;
+ struct rw_cmd cmd;
+ ssize_t ret;
+ NTSTATUS status;
+
+ if (aiocb->aio_nbytes > 128*1024) {
+ /* TODO: support variable buffers */
+ errno = EINVAL;
+ return -1;
+ }
+
+ status = get_idle_child(handle, &child);
+ if (!NT_STATUS_IS_OK(status)) {
+ DEBUG(10, ("Could not get an idle child\n"));
+ return -1;
+ }
+
+ 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;
+
+ 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 struct aio_child *aio_fork_find_child(struct vfs_handle_struct *handle,
+ SMB_STRUCT_AIOCB *aiocb)
+{
+ struct aio_child_list *children;
+ struct aio_child *child;
+
+ children = init_aio_children(handle);
+ if (children == NULL) {
+ return NULL;
+ }
+
+ for (child = children->children; child != NULL; child = child->next) {
+ if (child->aiocb == aiocb) {
+ return child;
+ }
+ }
+
+ return NULL;
+}
+
+static ssize_t aio_fork_return_fn(struct vfs_handle_struct *handle,
+ struct files_struct *fsp,
+ SMB_STRUCT_AIOCB *aiocb)
+{
+ struct aio_child *child = aio_fork_find_child(handle, aiocb);
+
+ if (child == NULL) {
+ errno = EINVAL;
+ DEBUG(0, ("returning EINVAL\n"));
+ return -1;
+ }
+
+ child->aiocb = NULL;
+
+ if (child->retval.size == -1) {
+ errno = child->retval.ret_errno;
+ }
+
+ return child->retval.size;
+}
+
+static int aio_fork_cancel(struct vfs_handle_struct *handle,
+ struct files_struct *fsp,
+ SMB_STRUCT_AIOCB *aiocb)
+{
+ struct aio_child_list *children;
+ struct aio_child *child;
+
+ children = init_aio_children(handle);
+ if (children == NULL) {
+ errno = EINVAL;
+ return -1;
+ }
+
+ 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.
+ */
+
+ child->cancelled = true;
+ }
+
+ return AIO_CANCELED;
+}
+
+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);
+
+ if (child == NULL) {
+ errno = EINVAL;
+ return -1;
+ }
+
+ return child->retval.ret_errno;
+}
+
+/* VFS operations structure */
+
+static vfs_op_tuple aio_fork_ops[] = {
+ {SMB_VFS_OP(aio_fork_read), SMB_VFS_OP_AIO_READ,
+ SMB_VFS_LAYER_TRANSPARENT},
+ {SMB_VFS_OP(aio_fork_write), SMB_VFS_OP_AIO_WRITE,
+ SMB_VFS_LAYER_TRANSPARENT},
+ {SMB_VFS_OP(aio_fork_return_fn), SMB_VFS_OP_AIO_RETURN,
+ SMB_VFS_LAYER_TRANSPARENT},
+ {SMB_VFS_OP(aio_fork_cancel), SMB_VFS_OP_AIO_CANCEL,
+ SMB_VFS_LAYER_TRANSPARENT},
+ {SMB_VFS_OP(aio_fork_error_fn), SMB_VFS_OP_AIO_ERROR,
+ SMB_VFS_LAYER_TRANSPARENT},
+ {SMB_VFS_OP(NULL), SMB_VFS_OP_NOOP,
+ SMB_VFS_LAYER_NOOP}
+};
+
+NTSTATUS vfs_aio_fork_init(void);
+NTSTATUS vfs_aio_fork_init(void)
+{
+ return smb_register_vfs(SMB_VFS_INTERFACE_VERSION,
+ "aio_fork", aio_fork_ops);
+}
git.samba.org / samba.git / commitdiff