--- /dev/null
+/*
+ * An implementation of a loadable kernel mode driver providing
+ * multiple kernel/user space bidirectional communications links.
+ *
+ * Author: Alan Cox <alan@lxorguk.ukuu.org.uk>
+ *
+ * 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.
+ *
+ * Adapted to become the Linux 2.0 Coda pseudo device
+ * Peter Braam <braam@maths.ox.ac.uk>
+ * Michael Callahan <mjc@emmy.smith.edu>
+ *
+ * Changes for Linux 2.1
+ * Copyright (c) 1997 Carnegie-Mellon University
+ */
+
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/major.h>
+#include <linux/time.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/ioport.h>
+#include <linux/fcntl.h>
+#include <linux/delay.h>
+#include <linux/skbuff.h>
+#include <linux/proc_fs.h>
+#include <linux/vmalloc.h>
+#include <linux/fs.h>
+#include <linux/file.h>
+#include <linux/poll.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/mutex.h>
+#include <linux/device.h>
+#include <linux/pid_namespace.h>
+#include <asm/io.h>
+#include <asm/poll.h>
+#include <linux/uaccess.h>
+
+#include <linux/coda.h>
+#include <linux/coda_psdev.h>
+
+#include "coda_linux.h"
+
+#include "coda_int.h"
+
+/* statistics */
+int coda_hard; /* allows signals during upcalls */
+unsigned long coda_timeout = 30; /* .. secs, then signals will dequeue */
+
+
+struct venus_comm coda_comms[MAX_CODADEVS];
+static struct class *coda_psdev_class;
+
+/*
+ * Device operations
+ */
+
+static unsigned int coda_psdev_poll(struct file *file, poll_table * wait)
+{
+ struct venus_comm *vcp = (struct venus_comm *) file->private_data;
+ unsigned int mask = POLLOUT | POLLWRNORM;
+
+ poll_wait(file, &vcp->vc_waitq, wait);
+ mutex_lock(&vcp->vc_mutex);
+ if (!list_empty(&vcp->vc_pending))
+ mask |= POLLIN | POLLRDNORM;
+ mutex_unlock(&vcp->vc_mutex);
+
+ return mask;
+}
+
+static long coda_psdev_ioctl(struct file * filp, unsigned int cmd, unsigned long arg)
+{
+ unsigned int data;
+
+ switch(cmd) {
+ case CIOC_KERNEL_VERSION:
+ data = CODA_KERNEL_VERSION;
+ return put_user(data, (int __user *) arg);
+ default:
+ return -ENOTTY;
+ }
+
+ return 0;
+}
+
+/*
+ * Receive a message written by Venus to the psdev
+ */
+
+static ssize_t coda_psdev_write(struct file *file, const char __user *buf,
+ size_t nbytes, loff_t *off)
+{
+ struct venus_comm *vcp = (struct venus_comm *) file->private_data;
+ struct upc_req *req = NULL;
+ struct upc_req *tmp;
+ struct list_head *lh;
+ struct coda_in_hdr hdr;
+ ssize_t retval = 0, count = 0;
+ int error;
+
+ /* Peek at the opcode, uniquefier */
+ if (copy_from_user(&hdr, buf, 2 * sizeof(u_long)))
+ return -EFAULT;
+
+ if (DOWNCALL(hdr.opcode)) {
+ union outputArgs *dcbuf;
+ int size = sizeof(*dcbuf);
+
+ if ( nbytes < sizeof(struct coda_out_hdr) ) {
+ pr_warn("coda_downcall opc %d uniq %d, not enough!\n",
+ hdr.opcode, hdr.unique);
+ count = nbytes;
+ goto out;
+ }
+ if ( nbytes > size ) {
+ pr_warn("downcall opc %d, uniq %d, too much!",
+ hdr.opcode, hdr.unique);
+ nbytes = size;
+ }
+ CODA_ALLOC(dcbuf, union outputArgs *, nbytes);
+ if (copy_from_user(dcbuf, buf, nbytes)) {
+ CODA_FREE(dcbuf, nbytes);
+ retval = -EFAULT;
+ goto out;
+ }
+
+ /* what downcall errors does Venus handle ? */
+ error = coda_downcall(vcp, hdr.opcode, dcbuf);
+
+ CODA_FREE(dcbuf, nbytes);
+ if (error) {
+ pr_warn("%s: coda_downcall error: %d\n",
+ __func__, error);
+ retval = error;
+ goto out;
+ }
+ count = nbytes;
+ goto out;
+ }
+
+ /* Look for the message on the processing queue. */
+ mutex_lock(&vcp->vc_mutex);
+ list_for_each(lh, &vcp->vc_processing) {
+ tmp = list_entry(lh, struct upc_req , uc_chain);
+ if (tmp->uc_unique == hdr.unique) {
+ req = tmp;
+ list_del(&req->uc_chain);
+ break;
+ }
+ }
+ mutex_unlock(&vcp->vc_mutex);
+
+ if (!req) {
+ pr_warn("%s: msg (%d, %d) not found\n",
+ __func__, hdr.opcode, hdr.unique);
+ retval = -ESRCH;
+ goto out;
+ }
+
+ /* move data into response buffer. */
+ if (req->uc_outSize < nbytes) {
+ pr_warn("%s: too much cnt: %d, cnt: %ld, opc: %d, uniq: %d.\n",
+ __func__, req->uc_outSize, (long)nbytes,
+ hdr.opcode, hdr.unique);
+ nbytes = req->uc_outSize; /* don't have more space! */
+ }
+ if (copy_from_user(req->uc_data, buf, nbytes)) {
+ req->uc_flags |= CODA_REQ_ABORT;
+ wake_up(&req->uc_sleep);
+ retval = -EFAULT;
+ goto out;
+ }
+
+ /* adjust outsize. is this useful ?? */
+ req->uc_outSize = nbytes;
+ req->uc_flags |= CODA_REQ_WRITE;
+ count = nbytes;
+
+ /* Convert filedescriptor into a file handle */
+ if (req->uc_opcode == CODA_OPEN_BY_FD) {
+ struct coda_open_by_fd_out *outp =
+ (struct coda_open_by_fd_out *)req->uc_data;
+ if (!outp->oh.result)
+ outp->fh = fget(outp->fd);
+ }
+
+ wake_up(&req->uc_sleep);
+out:
+ return(count ? count : retval);
+}
+
+/*
+ * Read a message from the kernel to Venus
+ */
+
+static ssize_t coda_psdev_read(struct file * file, char __user * buf,
+ size_t nbytes, loff_t *off)
+{
+ DECLARE_WAITQUEUE(wait, current);
+ struct venus_comm *vcp = (struct venus_comm *) file->private_data;
+ struct upc_req *req;
+ ssize_t retval = 0, count = 0;
+
+ if (nbytes == 0)
+ return 0;
+
+ mutex_lock(&vcp->vc_mutex);
+
+ add_wait_queue(&vcp->vc_waitq, &wait);
+ set_current_state(TASK_INTERRUPTIBLE);
+
+ while (list_empty(&vcp->vc_pending)) {
+ if (file->f_flags & O_NONBLOCK) {
+ retval = -EAGAIN;
+ break;
+ }
+ if (signal_pending(current)) {
+ retval = -ERESTARTSYS;
+ break;
+ }
+ mutex_unlock(&vcp->vc_mutex);
+ schedule();
+ mutex_lock(&vcp->vc_mutex);
+ }
+
+ set_current_state(TASK_RUNNING);
+ remove_wait_queue(&vcp->vc_waitq, &wait);
+
+ if (retval)
+ goto out;
+
+ req = list_entry(vcp->vc_pending.next, struct upc_req,uc_chain);
+ list_del(&req->uc_chain);
+
+ /* Move the input args into userspace */
+ count = req->uc_inSize;
+ if (nbytes < req->uc_inSize) {
+ pr_warn("%s: Venus read %ld bytes of %d in message\n",
+ __func__, (long)nbytes, req->uc_inSize);
+ count = nbytes;
+ }
+
+ if (copy_to_user(buf, req->uc_data, count))
+ retval = -EFAULT;
+
+ /* If request was not a signal, enqueue and don't free */
+ if (!(req->uc_flags & CODA_REQ_ASYNC)) {
+ req->uc_flags |= CODA_REQ_READ;
+ list_add_tail(&(req->uc_chain), &vcp->vc_processing);
+ goto out;
+ }
+
+ CODA_FREE(req->uc_data, sizeof(struct coda_in_hdr));
+ kfree(req);
+out:
+ mutex_unlock(&vcp->vc_mutex);
+ return (count ? count : retval);
+}
+
+static int coda_psdev_open(struct inode * inode, struct file * file)
+{
+ struct venus_comm *vcp;
+ int idx, err;
+
+ if (task_active_pid_ns(current) != &init_pid_ns)
+ return -EINVAL;
+
+ if (current_user_ns() != &init_user_ns)
+ return -EINVAL;
+
+ idx = iminor(inode);
+ if (idx < 0 || idx >= MAX_CODADEVS)
+ return -ENODEV;
+
+ err = -EBUSY;
+ vcp = &coda_comms[idx];
+ mutex_lock(&vcp->vc_mutex);
+
+ if (!vcp->vc_inuse) {
+ vcp->vc_inuse++;
+
+ INIT_LIST_HEAD(&vcp->vc_pending);
+ INIT_LIST_HEAD(&vcp->vc_processing);
+ init_waitqueue_head(&vcp->vc_waitq);
+ vcp->vc_sb = NULL;
+ vcp->vc_seq = 0;
+
+ file->private_data = vcp;
+ err = 0;
+ }
+
+ mutex_unlock(&vcp->vc_mutex);
+ return err;
+}
+
+
+static int coda_psdev_release(struct inode * inode, struct file * file)
+{
+ struct venus_comm *vcp = (struct venus_comm *) file->private_data;
+ struct upc_req *req, *tmp;
+
+ if (!vcp || !vcp->vc_inuse ) {
+ pr_warn("%s: Not open.\n", __func__);
+ return -1;
+ }
+
+ mutex_lock(&vcp->vc_mutex);
+
+ /* Wakeup clients so they can return. */
+ list_for_each_entry_safe(req, tmp, &vcp->vc_pending, uc_chain) {
+ list_del(&req->uc_chain);
+
+ /* Async requests need to be freed here */
+ if (req->uc_flags & CODA_REQ_ASYNC) {
+ CODA_FREE(req->uc_data, sizeof(struct coda_in_hdr));
+ kfree(req);
+ continue;
+ }
+ req->uc_flags |= CODA_REQ_ABORT;
+ wake_up(&req->uc_sleep);
+ }
+
+ list_for_each_entry_safe(req, tmp, &vcp->vc_processing, uc_chain) {
+ list_del(&req->uc_chain);
+
+ req->uc_flags |= CODA_REQ_ABORT;
+ wake_up(&req->uc_sleep);
+ }
+
+ file->private_data = NULL;
+ vcp->vc_inuse--;
+ mutex_unlock(&vcp->vc_mutex);
+ return 0;
+}
+
+
+static const struct file_operations coda_psdev_fops = {
+ .owner = THIS_MODULE,
+ .read = coda_psdev_read,
+ .write = coda_psdev_write,
+ .poll = coda_psdev_poll,
+ .unlocked_ioctl = coda_psdev_ioctl,
+ .open = coda_psdev_open,
+ .release = coda_psdev_release,
+ .llseek = noop_llseek,
+};
+
+static int init_coda_psdev(void)
+{
+ int i, err = 0;
+ if (register_chrdev(CODA_PSDEV_MAJOR, "coda", &coda_psdev_fops)) {
+ pr_err("%s: unable to get major %d\n",
+ __func__, CODA_PSDEV_MAJOR);
+ return -EIO;
+ }
+ coda_psdev_class = class_create(THIS_MODULE, "coda");
+ if (IS_ERR(coda_psdev_class)) {
+ err = PTR_ERR(coda_psdev_class);
+ goto out_chrdev;
+ }
+ for (i = 0; i < MAX_CODADEVS; i++) {
+ mutex_init(&(&coda_comms[i])->vc_mutex);
+ device_create(coda_psdev_class, NULL,
+ MKDEV(CODA_PSDEV_MAJOR, i), NULL, "cfs%d", i);
+ }
+ coda_sysctl_init();
+ goto out;
+
+out_chrdev:
+ unregister_chrdev(CODA_PSDEV_MAJOR, "coda");
+out:
+ return err;
+}
+
+MODULE_AUTHOR("Jan Harkes, Peter J. Braam");
+MODULE_DESCRIPTION("Coda Distributed File System VFS interface");
+MODULE_ALIAS_CHARDEV_MAJOR(CODA_PSDEV_MAJOR);
+MODULE_LICENSE("GPL");
+MODULE_VERSION("6.6");
+
+static int __init init_coda(void)
+{
+ int status;
+ int i;
+
+ status = coda_init_inodecache();
+ if (status)
+ goto out2;
+ status = init_coda_psdev();
+ if ( status ) {
+ pr_warn("Problem (%d) in init_coda_psdev\n", status);
+ goto out1;
+ }
+
+ status = register_filesystem(&coda_fs_type);
+ if (status) {
+ pr_warn("failed to register filesystem!\n");
+ goto out;
+ }
+ return 0;
+out:
+ for (i = 0; i < MAX_CODADEVS; i++)
+ device_destroy(coda_psdev_class, MKDEV(CODA_PSDEV_MAJOR, i));
+ class_destroy(coda_psdev_class);
+ unregister_chrdev(CODA_PSDEV_MAJOR, "coda");
+ coda_sysctl_clean();
+out1:
+ coda_destroy_inodecache();
+out2:
+ return status;
+}
+
+static void __exit exit_coda(void)
+{
+ int err, i;
+
+ err = unregister_filesystem(&coda_fs_type);
+ if (err != 0)
+ pr_warn("failed to unregister filesystem\n");
+ for (i = 0; i < MAX_CODADEVS; i++)
+ device_destroy(coda_psdev_class, MKDEV(CODA_PSDEV_MAJOR, i));
+ class_destroy(coda_psdev_class);
+ unregister_chrdev(CODA_PSDEV_MAJOR, "coda");
+ coda_sysctl_clean();
+ coda_destroy_inodecache();
+}
+
+module_init(init_coda);
+module_exit(exit_coda);
+
Code Review / kvmfornfv.git / blobdiff