diff options
Diffstat (limited to 'fs/coda/psdev.c')
| -rw-r--r-- | fs/coda/psdev.c | 462 |
1 files changed, 462 insertions, 0 deletions
diff --git a/fs/coda/psdev.c b/fs/coda/psdev.c new file mode 100644 index 000000000000..ef001a9313e6 --- /dev/null +++ b/fs/coda/psdev.c @@ -0,0 +1,462 @@ +/* + * An implementation of a loadable kernel mode driver providing + * multiple kernel/user space bidirectional communications links. + * + * Author: Alan Cox <alan@redhat.com> + * + * 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/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/devfs_fs_kernel.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/smp_lock.h> +#include <linux/device.h> +#include <asm/io.h> +#include <asm/system.h> +#include <asm/poll.h> +#include <asm/uaccess.h> + +#include <linux/coda.h> +#include <linux/coda_linux.h> +#include <linux/coda_fs_i.h> +#include <linux/coda_psdev.h> +#include <linux/coda_proc.h> + +#define upc_free(r) kfree(r) + +/* + * Coda stuff + */ +extern struct file_system_type coda_fs_type; + +/* 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_simple *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); + if (!list_empty(&vcp->vc_pending)) + mask |= POLLIN | POLLRDNORM; + + return mask; +} + +static int coda_psdev_ioctl(struct inode * inode, 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)) { + struct super_block *sb = NULL; + union outputArgs *dcbuf; + int size = sizeof(*dcbuf); + + sb = vcp->vc_sb; + if ( !sb ) { + count = nbytes; + goto out; + } + + if ( nbytes < sizeof(struct coda_out_hdr) ) { + printk("coda_downcall opc %d uniq %d, not enough!\n", + hdr.opcode, hdr.unique); + count = nbytes; + goto out; + } + if ( nbytes > size ) { + printk("Coda: 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 ? */ + lock_kernel(); + error = coda_downcall(hdr.opcode, dcbuf, sb); + unlock_kernel(); + + CODA_FREE(dcbuf, nbytes); + if (error) { + printk("psdev_write: coda_downcall error: %d\n", error); + retval = error; + goto out; + } + count = nbytes; + goto out; + } + + /* Look for the message on the processing queue. */ + lock_kernel(); + 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; + } + } + unlock_kernel(); + + if (!req) { + printk("psdev_write: msg (%d, %d) not found\n", + hdr.opcode, hdr.unique); + retval = -ESRCH; + goto out; + } + + /* move data into response buffer. */ + if (req->uc_outSize < nbytes) { + printk("psdev_write: too much cnt: %d, cnt: %ld, opc: %d, uniq: %d.\n", + 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 |= REQ_ABORT; + wake_up(&req->uc_sleep); + retval = -EFAULT; + goto out; + } + + /* adjust outsize. is this useful ?? */ + req->uc_outSize = nbytes; + req->uc_flags |= 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; + 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; + + lock_kernel(); + + 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; + } + schedule(); + } + + 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) { + printk ("psdev_read: Venus read %ld bytes of %d in message\n", + (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 & REQ_ASYNC)) { + req->uc_flags |= REQ_READ; + list_add(&(req->uc_chain), vcp->vc_processing.prev); + goto out; + } + + CODA_FREE(req->uc_data, sizeof(struct coda_in_hdr)); + upc_free(req); +out: + unlock_kernel(); + return (count ? count : retval); +} + +static int coda_psdev_open(struct inode * inode, struct file * file) +{ + struct venus_comm *vcp; + int idx; + + lock_kernel(); + idx = iminor(inode); + if(idx >= MAX_CODADEVS) { + unlock_kernel(); + return -ENODEV; + } + + vcp = &coda_comms[idx]; + if(vcp->vc_inuse) { + unlock_kernel(); + return -EBUSY; + } + + if (!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; + + unlock_kernel(); + return 0; +} + + +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; + + lock_kernel(); + if ( !vcp->vc_inuse ) { + unlock_kernel(); + printk("psdev_release: Not open.\n"); + return -1; + } + + if (--vcp->vc_inuse) { + unlock_kernel(); + return 0; + } + + /* Wakeup clients so they can return. */ + list_for_each_entry_safe(req, tmp, &vcp->vc_pending, uc_chain) { + /* Async requests need to be freed here */ + if (req->uc_flags & REQ_ASYNC) { + CODA_FREE(req->uc_data, sizeof(struct coda_in_hdr)); + upc_free(req); + continue; + } + req->uc_flags |= REQ_ABORT; + wake_up(&req->uc_sleep); + } + + list_for_each_entry(req, &vcp->vc_processing, uc_chain) { + req->uc_flags |= REQ_ABORT; + wake_up(&req->uc_sleep); + } + + unlock_kernel(); + return 0; +} + + +static struct file_operations coda_psdev_fops = { + .owner = THIS_MODULE, + .read = coda_psdev_read, + .write = coda_psdev_write, + .poll = coda_psdev_poll, + .ioctl = coda_psdev_ioctl, + .open = coda_psdev_open, + .release = coda_psdev_release, +}; + +static int init_coda_psdev(void) +{ + int i, err = 0; + if (register_chrdev(CODA_PSDEV_MAJOR, "coda", &coda_psdev_fops)) { + printk(KERN_ERR "coda_psdev: unable to get major %d\n", + CODA_PSDEV_MAJOR); + return -EIO; + } + coda_psdev_class = class_simple_create(THIS_MODULE, "coda"); + if (IS_ERR(coda_psdev_class)) { + err = PTR_ERR(coda_psdev_class); + goto out_chrdev; + } + devfs_mk_dir ("coda"); + for (i = 0; i < MAX_CODADEVS; i++) { + class_simple_device_add(coda_psdev_class, MKDEV(CODA_PSDEV_MAJOR,i), + NULL, "cfs%d", i); + err = devfs_mk_cdev(MKDEV(CODA_PSDEV_MAJOR, i), + S_IFCHR|S_IRUSR|S_IWUSR, "coda/%d", i); + if (err) + goto out_class; + } + coda_sysctl_init(); + goto out; + +out_class: + for (i = 0; i < MAX_CODADEVS; i++) + class_simple_device_remove(MKDEV(CODA_PSDEV_MAJOR, i)); + class_simple_destroy(coda_psdev_class); +out_chrdev: + unregister_chrdev(CODA_PSDEV_MAJOR, "coda"); +out: + return err; +} + + +MODULE_AUTHOR("Peter J. Braam <braam@cs.cmu.edu>"); +MODULE_LICENSE("GPL"); + +extern int coda_init_inodecache(void); +extern void coda_destroy_inodecache(void); +static int __init init_coda(void) +{ + int status; + int i; + printk(KERN_INFO "Coda Kernel/Venus communications, " +#ifdef CONFIG_CODA_FS_OLD_API + "v5.3.20" +#else + "v6.0.0" +#endif + ", coda@cs.cmu.edu\n"); + + status = coda_init_inodecache(); + if (status) + goto out2; + status = init_coda_psdev(); + if ( status ) { + printk("Problem (%d) in init_coda_psdev\n", status); + goto out1; + } + + status = register_filesystem(&coda_fs_type); + if (status) { + printk("coda: failed to register filesystem!\n"); + goto out; + } + return 0; +out: + for (i = 0; i < MAX_CODADEVS; i++) { + class_simple_device_remove(MKDEV(CODA_PSDEV_MAJOR, i)); + devfs_remove("coda/%d", i); + } + class_simple_destroy(coda_psdev_class); + devfs_remove("coda"); + 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 ) { + printk("coda: failed to unregister filesystem\n"); + } + for (i = 0; i < MAX_CODADEVS; i++) { + class_simple_device_remove(MKDEV(CODA_PSDEV_MAJOR, i)); + devfs_remove("coda/%d", i); + } + class_simple_destroy(coda_psdev_class); + devfs_remove("coda"); + unregister_chrdev(CODA_PSDEV_MAJOR, "coda"); + coda_sysctl_clean(); + coda_destroy_inodecache(); +} + +module_init(init_coda); +module_exit(exit_coda); + |