Something went wrong. Try again.
Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Something went wrong. Try again.
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439// SPDX-License-Identifier: GPL-2.0-or-later/* * An implementation of a loadable kernel mode driver providing * multiple kernel/user space bidirectional communications links. * * Author: Alan Cox <alan@lxorguk.ukuu.org.uk> * * 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/uaccess.h>
#include <linux/coda.h>#include "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;
/* make sure there is enough to copy out the (opcode, unique) values */ if (nbytes < (2 * sizeof(u_int32_t))) return -EINVAL;
/* Peek at the opcode, uniquefier */ if (copy_from_user(&hdr, buf, 2 * sizeof(u_int32_t))) 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; }
dcbuf = vmemdup_user(buf, nbytes); if (IS_ERR(dcbuf)) { retval = PTR_ERR(dcbuf); goto out; }
/* what downcall errors does Venus handle ? */ error = coda_downcall(vcp, hdr.opcode, dcbuf, nbytes);
kvfree(dcbuf); 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); if (!outp->fh) return -EBADF; } }
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; }
kvfree(req->uc_data); 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) { kvfree(req->uc_data); 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 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("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("7.2");
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);