Initial import

1 files changed, 437 insertions, 0 deletions

diff --git a/fs/coda/psdev.c b/fs/coda/psdev.c
new file mode 100644
index 000000000..822629126
--- /dev/null
+++ b/fs/coda/psdev.c
@@ -0,0 +1,437 @@
+/*
+ *      	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);
+