Add initial AIO/LIO kernel thread support files. This is preliminary, and

further features will be added.

1 files changed, 264 insertions, 0 deletions

diff --git a/sys/kern/vfs_aio.c b/sys/kern/vfs_aio.c
new file mode 100644
index 000000000000..282eee492f4a
--- /dev/null
+++ b/sys/kern/vfs_aio.c
@@ -0,0 +1,264 @@
+
+/*
+ * Copyright (c) 1997 John S. Dyson.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. John S. Dyson's name may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * DISCLAIMER:  This code isn't warranted to do anything useful.  Anything
+ * bad that happens because of using this software isn't the responsibility
+ * of the author.  This software is distributed AS-IS.
+ *
+ * $Id$
+ */
+
+/*
+ * This file contains support for the POSIX.4 AIO facility.
+ *
+ * The initial version provides only the (bogus) synchronous semantics
+ * but will support async in the future.  Note that a bit
+ * in a private field allows the user mode subroutine to adapt
+ * the kernel operations to true POSIX.4 for future compatibility.
+ *
+ * This code is used to support true POSIX.4 AIO/LIO with the help
+ * of a user mode subroutine package.  Note that eventually more support
+ * will be pushed into the kernel.
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/sysent.h>
+#include <sys/sysproto.h>
+#include <sys/namei.h>
+#include <sys/filedesc.h>
+#include <sys/kernel.h>
+#include <sys/fcntl.h>
+#include <sys/file.h>
+#include <sys/stat.h>
+#include <sys/unistd.h>
+#include <sys/vnode.h>
+#include <sys/mount.h>
+#include <sys/proc.h>
+#include <sys/uio.h>
+#include <sys/malloc.h>
+#include <sys/dirent.h>
+#include <sys/signalvar.h>
+
+#include <vm/vm.h>
+#include <vm/vm_param.h>
+#include <vm/vm_object.h>
+#include <vm/vm_extern.h>
+#include <sys/sysctl.h>
+#include <sys/aio.h>
+
+
+/*
+ * aio_cancel at the kernel level is a NOOP right now.  It
+ * might be possible to support it partially in user mode, or
+ * in kernel mode later on.
+ */
+int
+aio_cancel(struct proc *p, struct aio_cancel_args *uap, int *retval) {
+	return AIO_NOTCANCELLED;
+}
+
+
+/*
+ * aio_error is implemented in the kernel level for compatibility
+ * purposes only.  For a user mode async implementation, it would be
+ * best to do it in a userland subroutine.
+ */
+int
+aio_error(struct proc *p, struct aio_error_args *uap, int *retval) {
+	int activeflag, errorcode;
+	struct aiocb iocb;
+	int error;
+
+	/*
+	 * Get control block
+	 */
+	if (error = copyin((caddr_t) uap->aiocbp, (caddr_t) &iocb, sizeof iocb))
+		return error;
+	if (iocb._aiocb_private.active == -1)
+		return EFAULT;
+
+	if (iocb._aiocb_private.active != AIO_PMODE_ACTIVE) {
+		retval[0] = EINVAL;
+		return(0);
+	}
+
+	retval[0] = iocb._aiocb_private.error;
+	return(0);
+}
+
+int
+aio_read(struct proc *p, struct aio_read_args *uap, int *retval) {
+	struct filedesc *fdp;
+	struct file *fp;
+	struct uio auio;
+	struct iovec aiov;
+	unsigned int fd;
+	int cnt;
+	struct aiocb iocb;
+	int error;
+
+
+	/*
+	 * Get control block
+	 */
+	if (error = copyin((caddr_t) uap->aiocbp, (caddr_t) &iocb, sizeof iocb))
+		return error;
+
+	/*
+	 * We support sync only for now.
+	 */
+	if ((iocb._aiocb_private.privatemodes & AIO_PMODE_SYNC) == 0)
+		return ENOSYS;
+
+	/*
+	 * Get the fd info for process
+	 */
+	fdp = p->p_fd;
+
+	/*
+	 * Range check file descriptor
+	 */
+	fd = iocb.aio_fildes;
+	if (fd >= fdp->fd_nfiles)
+		return EBADF;
+	fp = fdp->fd_ofiles[fd];
+	if ((fp == NULL) || ((fp->f_flag & FREAD) == 0))
+		return EBADF;
+	if (((int) iocb.aio_offset) == -1)
+		return EINVAL;
+
+	aiov.iov_base = iocb.aio_buf;
+	aiov.iov_len = iocb.aio_nbytes;
+	auio.uio_iov = &aiov;
+	auio.uio_iovcnt = 1;
+	auio.uio_offset = iocb.aio_offset;
+
+	auio.uio_resid = iocb.aio_nbytes;
+	if (auio.uio_resid < 0)
+		return (EINVAL);
+
+	auio.uio_rw = UIO_READ;
+	auio.uio_segflg = UIO_USERSPACE;
+	auio.uio_procp = p;
+
+	cnt = iocb.aio_nbytes;
+	error = (*fp->f_ops->fo_read)(fp, &auio, fp->f_cred);
+	if (error &&
+		(auio.uio_resid != cnt) &&
+		(error == ERESTART || error == EINTR || error == EWOULDBLOCK))
+			error = 0;
+	cnt -= auio.uio_resid;
+	*retval = cnt;
+	return error;
+}
+
+
+/*
+ * Return and suspend aren't supported (yet).
+ */
+int
+aio_return(struct proc *p, struct aio_return_args *uap, int *retval) {
+	return (0);
+}
+
+int
+aio_suspend(struct proc *p, struct aio_suspend_args *uap, int *retval) {
+	return (0);
+}
+
+int
+aio_write(struct proc *p, struct aio_write_args *uap, int *retval) {
+	struct filedesc *fdp;
+	struct file *fp;
+	struct uio auio;
+	struct iovec aiov;
+	unsigned int fd;
+	int cnt;
+	struct aiocb iocb;
+	int error;
+
+	if (error = copyin((caddr_t) uap->aiocbp, (caddr_t) &iocb, sizeof iocb))
+		return error;
+
+	/*
+	 * We support sync only for now.
+	 */
+	if ((iocb._aiocb_private.privatemodes & AIO_PMODE_SYNC) == 0)
+		return ENOSYS;
+
+	/*
+	 * Get the fd info for process
+	 */
+	fdp = p->p_fd;
+
+	/*
+	 * Range check file descriptor
+	 */
+	fd = iocb.aio_fildes;
+	if (fd >= fdp->fd_nfiles)
+		return EBADF;
+	fp = fdp->fd_ofiles[fd];
+	if ((fp == NULL) || ((fp->f_flag & FWRITE) == 0))
+		return EBADF;
+	if (((int) iocb.aio_offset) == -1)
+		return EINVAL;
+
+	aiov.iov_base = iocb.aio_buf;
+	aiov.iov_len = iocb.aio_nbytes;
+	auio.uio_iov = &aiov;
+	auio.uio_iovcnt = 1;
+	auio.uio_offset = iocb.aio_offset;
+
+	auio.uio_resid = iocb.aio_nbytes;
+	if (auio.uio_resid < 0)
+		return (EINVAL);
+
+	auio.uio_rw = UIO_WRITE;
+	auio.uio_segflg = UIO_USERSPACE;
+	auio.uio_procp = p;
+
+	cnt = iocb.aio_nbytes;
+	error = (*fp->f_ops->fo_write)(fp, &auio, fp->f_cred);
+	if (error) {
+		if (auio.uio_resid != cnt) {
+			if (error == ERESTART || error == EINTR || error == EWOULDBLOCK)
+				error = 0;
+			if (error == EPIPE)
+				psignal(p, SIGPIPE);
+		}
+	}
+	cnt -= auio.uio_resid;
+	*retval = cnt;
+	return error;
+}
+
+int
+lio_listio(struct proc *p, struct lio_listio_args *uap, int *retval) {
+	struct filedesc *fdp;
+	struct file *fp;
+	struct uio auio;
+	struct iovec aiov;
+	unsigned int fd;
+	int cnt;
+	unsigned int iocblen, iocbcnt;
+	struct aiocb *iocb;
+	int error;
+	int i;
+
+	if (uap->mode == LIO_NOWAIT)
+		return ENOSYS;
+	iocbcnt = uap->nent;
+	if (iocbcnt > AIO_LISTIO_MAX)
+		return EINVAL;
+	return ENOSYS;
+}