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kernel-ark/fs/coda/psdev.c
Linus Torvalds a9a08845e9 vfs: do bulk POLL* -> EPOLL* replacement 
This is the mindless scripted replacement of kernel use of POLL*
variables as described by Al, done by this script:

    for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do
        L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'`
        for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done
    done

with de-mangling cleanups yet to come.

NOTE! On almost all architectures, the EPOLL* constants have the same
values as the POLL* constants do.  But they keyword here is "almost".
For various bad reasons they aren't the same, and epoll() doesn't
actually work quite correctly in some cases due to this on Sparc et al.

The next patch from Al will sort out the final differences, and we
should be all done.

Scripted-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-11 14:34:03 -08:00

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/*
* 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/signal.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 <linux/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 __poll_t coda_psdev_poll(struct file *file, poll_table * wait)
{
struct venus_comm *vcp = (struct venus_comm *) file->private_data;
__poll_t mask = EPOLLOUT | EPOLLWRNORM;
poll_wait(file, &vcp->vc_waitq, wait);
mutex_lock(&vcp->vc_mutex);
if (!list_empty(&vcp->vc_pending))
mask |= EPOLLIN | EPOLLRDNORM;
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);
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