1 /* 2 * An implementation of a loadable kernel mode driver providing 3 * multiple kernel/user space bidirectional communications links. 4 * 5 * Author: Alan Cox <alan@lxorguk.ukuu.org.uk> 6 * 7 * This program is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU General Public License 9 * as published by the Free Software Foundation; either version 10 * 2 of the License, or (at your option) any later version. 11 * 12 * Adapted to become the Linux 2.0 Coda pseudo device 13 * Peter Braam <braam@maths.ox.ac.uk> 14 * Michael Callahan <mjc@emmy.smith.edu> 15 * 16 * Changes for Linux 2.1 17 * Copyright (c) 1997 Carnegie-Mellon University 18 */ 19 20 #include <linux/module.h> 21 #include <linux/errno.h> 22 #include <linux/kernel.h> 23 #include <linux/major.h> 24 #include <linux/time.h> 25 #include <linux/sched.h> 26 #include <linux/slab.h> 27 #include <linux/ioport.h> 28 #include <linux/fcntl.h> 29 #include <linux/delay.h> 30 #include <linux/skbuff.h> 31 #include <linux/proc_fs.h> 32 #include <linux/vmalloc.h> 33 #include <linux/fs.h> 34 #include <linux/file.h> 35 #include <linux/poll.h> 36 #include <linux/init.h> 37 #include <linux/list.h> 38 #include <linux/smp_lock.h> 39 #include <linux/device.h> 40 #include <asm/io.h> 41 #include <asm/system.h> 42 #include <asm/poll.h> 43 #include <asm/uaccess.h> 44 45 #include <linux/coda.h> 46 #include <linux/coda_linux.h> 47 #include <linux/coda_fs_i.h> 48 #include <linux/coda_psdev.h> 49 50 #include "coda_int.h" 51 52 /* statistics */ 53 int coda_hard; /* allows signals during upcalls */ 54 unsigned long coda_timeout = 30; /* .. secs, then signals will dequeue */ 55 56 57 struct venus_comm coda_comms[MAX_CODADEVS]; 58 static struct class *coda_psdev_class; 59 60 /* 61 * Device operations 62 */ 63 64 static unsigned int coda_psdev_poll(struct file *file, poll_table * wait) 65 { 66 struct venus_comm *vcp = (struct venus_comm *) file->private_data; 67 unsigned int mask = POLLOUT | POLLWRNORM; 68 69 poll_wait(file, &vcp->vc_waitq, wait); 70 if (!list_empty(&vcp->vc_pending)) 71 mask |= POLLIN | POLLRDNORM; 72 73 return mask; 74 } 75 76 static long coda_psdev_ioctl(struct file * filp, unsigned int cmd, unsigned long arg) 77 { 78 unsigned int data; 79 80 switch(cmd) { 81 case CIOC_KERNEL_VERSION: 82 data = CODA_KERNEL_VERSION; 83 return put_user(data, (int __user *) arg); 84 default: 85 return -ENOTTY; 86 } 87 88 return 0; 89 } 90 91 /* 92 * Receive a message written by Venus to the psdev 93 */ 94 95 static ssize_t coda_psdev_write(struct file *file, const char __user *buf, 96 size_t nbytes, loff_t *off) 97 { 98 struct venus_comm *vcp = (struct venus_comm *) file->private_data; 99 struct upc_req *req = NULL; 100 struct upc_req *tmp; 101 struct list_head *lh; 102 struct coda_in_hdr hdr; 103 ssize_t retval = 0, count = 0; 104 int error; 105 106 /* Peek at the opcode, uniquefier */ 107 if (copy_from_user(&hdr, buf, 2 * sizeof(u_long))) 108 return -EFAULT; 109 110 if (DOWNCALL(hdr.opcode)) { 111 struct super_block *sb = NULL; 112 union outputArgs *dcbuf; 113 int size = sizeof(*dcbuf); 114 115 sb = vcp->vc_sb; 116 if ( !sb ) { 117 count = nbytes; 118 goto out; 119 } 120 121 if ( nbytes < sizeof(struct coda_out_hdr) ) { 122 printk("coda_downcall opc %d uniq %d, not enough!\n", 123 hdr.opcode, hdr.unique); 124 count = nbytes; 125 goto out; 126 } 127 if ( nbytes > size ) { 128 printk("Coda: downcall opc %d, uniq %d, too much!", 129 hdr.opcode, hdr.unique); 130 nbytes = size; 131 } 132 CODA_ALLOC(dcbuf, union outputArgs *, nbytes); 133 if (copy_from_user(dcbuf, buf, nbytes)) { 134 CODA_FREE(dcbuf, nbytes); 135 retval = -EFAULT; 136 goto out; 137 } 138 139 /* what downcall errors does Venus handle ? */ 140 lock_kernel(); 141 error = coda_downcall(hdr.opcode, dcbuf, sb); 142 unlock_kernel(); 143 144 CODA_FREE(dcbuf, nbytes); 145 if (error) { 146 printk("psdev_write: coda_downcall error: %d\n", error); 147 retval = error; 148 goto out; 149 } 150 count = nbytes; 151 goto out; 152 } 153 154 /* Look for the message on the processing queue. */ 155 lock_kernel(); 156 list_for_each(lh, &vcp->vc_processing) { 157 tmp = list_entry(lh, struct upc_req , uc_chain); 158 if (tmp->uc_unique == hdr.unique) { 159 req = tmp; 160 list_del(&req->uc_chain); 161 break; 162 } 163 } 164 unlock_kernel(); 165 166 if (!req) { 167 printk("psdev_write: msg (%d, %d) not found\n", 168 hdr.opcode, hdr.unique); 169 retval = -ESRCH; 170 goto out; 171 } 172 173 /* move data into response buffer. */ 174 if (req->uc_outSize < nbytes) { 175 printk("psdev_write: too much cnt: %d, cnt: %ld, opc: %d, uniq: %d.\n", 176 req->uc_outSize, (long)nbytes, hdr.opcode, hdr.unique); 177 nbytes = req->uc_outSize; /* don't have more space! */ 178 } 179 if (copy_from_user(req->uc_data, buf, nbytes)) { 180 req->uc_flags |= REQ_ABORT; 181 wake_up(&req->uc_sleep); 182 retval = -EFAULT; 183 goto out; 184 } 185 186 /* adjust outsize. is this useful ?? */ 187 req->uc_outSize = nbytes; 188 req->uc_flags |= REQ_WRITE; 189 count = nbytes; 190 191 /* Convert filedescriptor into a file handle */ 192 if (req->uc_opcode == CODA_OPEN_BY_FD) { 193 struct coda_open_by_fd_out *outp = 194 (struct coda_open_by_fd_out *)req->uc_data; 195 if (!outp->oh.result) 196 outp->fh = fget(outp->fd); 197 } 198 199 wake_up(&req->uc_sleep); 200 out: 201 return(count ? count : retval); 202 } 203 204 /* 205 * Read a message from the kernel to Venus 206 */ 207 208 static ssize_t coda_psdev_read(struct file * file, char __user * buf, 209 size_t nbytes, loff_t *off) 210 { 211 DECLARE_WAITQUEUE(wait, current); 212 struct venus_comm *vcp = (struct venus_comm *) file->private_data; 213 struct upc_req *req; 214 ssize_t retval = 0, count = 0; 215 216 if (nbytes == 0) 217 return 0; 218 219 lock_kernel(); 220 221 add_wait_queue(&vcp->vc_waitq, &wait); 222 set_current_state(TASK_INTERRUPTIBLE); 223 224 while (list_empty(&vcp->vc_pending)) { 225 if (file->f_flags & O_NONBLOCK) { 226 retval = -EAGAIN; 227 break; 228 } 229 if (signal_pending(current)) { 230 retval = -ERESTARTSYS; 231 break; 232 } 233 schedule(); 234 } 235 236 set_current_state(TASK_RUNNING); 237 remove_wait_queue(&vcp->vc_waitq, &wait); 238 239 if (retval) 240 goto out; 241 242 req = list_entry(vcp->vc_pending.next, struct upc_req,uc_chain); 243 list_del(&req->uc_chain); 244 245 /* Move the input args into userspace */ 246 count = req->uc_inSize; 247 if (nbytes < req->uc_inSize) { 248 printk ("psdev_read: Venus read %ld bytes of %d in message\n", 249 (long)nbytes, req->uc_inSize); 250 count = nbytes; 251 } 252 253 if (copy_to_user(buf, req->uc_data, count)) 254 retval = -EFAULT; 255 256 /* If request was not a signal, enqueue and don't free */ 257 if (!(req->uc_flags & REQ_ASYNC)) { 258 req->uc_flags |= REQ_READ; 259 list_add_tail(&(req->uc_chain), &vcp->vc_processing); 260 goto out; 261 } 262 263 CODA_FREE(req->uc_data, sizeof(struct coda_in_hdr)); 264 kfree(req); 265 out: 266 unlock_kernel(); 267 return (count ? count : retval); 268 } 269 270 static int coda_psdev_open(struct inode * inode, struct file * file) 271 { 272 struct venus_comm *vcp; 273 int idx, err; 274 275 idx = iminor(inode); 276 if (idx < 0 || idx >= MAX_CODADEVS) 277 return -ENODEV; 278 279 lock_kernel(); 280 281 err = -EBUSY; 282 vcp = &coda_comms[idx]; 283 if (!vcp->vc_inuse) { 284 vcp->vc_inuse++; 285 286 INIT_LIST_HEAD(&vcp->vc_pending); 287 INIT_LIST_HEAD(&vcp->vc_processing); 288 init_waitqueue_head(&vcp->vc_waitq); 289 vcp->vc_sb = NULL; 290 vcp->vc_seq = 0; 291 292 file->private_data = vcp; 293 err = 0; 294 } 295 296 unlock_kernel(); 297 return err; 298 } 299 300 301 static int coda_psdev_release(struct inode * inode, struct file * file) 302 { 303 struct venus_comm *vcp = (struct venus_comm *) file->private_data; 304 struct upc_req *req, *tmp; 305 306 if (!vcp || !vcp->vc_inuse ) { 307 printk("psdev_release: Not open.\n"); 308 return -1; 309 } 310 311 lock_kernel(); 312 313 /* Wakeup clients so they can return. */ 314 list_for_each_entry_safe(req, tmp, &vcp->vc_pending, uc_chain) { 315 list_del(&req->uc_chain); 316 317 /* Async requests need to be freed here */ 318 if (req->uc_flags & REQ_ASYNC) { 319 CODA_FREE(req->uc_data, sizeof(struct coda_in_hdr)); 320 kfree(req); 321 continue; 322 } 323 req->uc_flags |= REQ_ABORT; 324 wake_up(&req->uc_sleep); 325 } 326 327 list_for_each_entry_safe(req, tmp, &vcp->vc_processing, uc_chain) { 328 list_del(&req->uc_chain); 329 330 req->uc_flags |= REQ_ABORT; 331 wake_up(&req->uc_sleep); 332 } 333 334 file->private_data = NULL; 335 vcp->vc_inuse--; 336 unlock_kernel(); 337 return 0; 338 } 339 340 341 static const struct file_operations coda_psdev_fops = { 342 .owner = THIS_MODULE, 343 .read = coda_psdev_read, 344 .write = coda_psdev_write, 345 .poll = coda_psdev_poll, 346 .unlocked_ioctl = coda_psdev_ioctl, 347 .open = coda_psdev_open, 348 .release = coda_psdev_release, 349 }; 350 351 static int init_coda_psdev(void) 352 { 353 int i, err = 0; 354 if (register_chrdev(CODA_PSDEV_MAJOR, "coda", &coda_psdev_fops)) { 355 printk(KERN_ERR "coda_psdev: unable to get major %d\n", 356 CODA_PSDEV_MAJOR); 357 return -EIO; 358 } 359 coda_psdev_class = class_create(THIS_MODULE, "coda"); 360 if (IS_ERR(coda_psdev_class)) { 361 err = PTR_ERR(coda_psdev_class); 362 goto out_chrdev; 363 } 364 for (i = 0; i < MAX_CODADEVS; i++) 365 device_create(coda_psdev_class, NULL, 366 MKDEV(CODA_PSDEV_MAJOR, i), NULL, "cfs%d", i); 367 coda_sysctl_init(); 368 goto out; 369 370 out_chrdev: 371 unregister_chrdev(CODA_PSDEV_MAJOR, "coda"); 372 out: 373 return err; 374 } 375 376 MODULE_AUTHOR("Jan Harkes, Peter J. Braam"); 377 MODULE_DESCRIPTION("Coda Distributed File System VFS interface"); 378 MODULE_ALIAS_CHARDEV_MAJOR(CODA_PSDEV_MAJOR); 379 MODULE_LICENSE("GPL"); 380 MODULE_VERSION("6.6"); 381 382 static int __init init_coda(void) 383 { 384 int status; 385 int i; 386 387 status = coda_init_inodecache(); 388 if (status) 389 goto out2; 390 status = init_coda_psdev(); 391 if ( status ) { 392 printk("Problem (%d) in init_coda_psdev\n", status); 393 goto out1; 394 } 395 396 status = register_filesystem(&coda_fs_type); 397 if (status) { 398 printk("coda: failed to register filesystem!\n"); 399 goto out; 400 } 401 return 0; 402 out: 403 for (i = 0; i < MAX_CODADEVS; i++) 404 device_destroy(coda_psdev_class, MKDEV(CODA_PSDEV_MAJOR, i)); 405 class_destroy(coda_psdev_class); 406 unregister_chrdev(CODA_PSDEV_MAJOR, "coda"); 407 coda_sysctl_clean(); 408 out1: 409 coda_destroy_inodecache(); 410 out2: 411 return status; 412 } 413 414 static void __exit exit_coda(void) 415 { 416 int err, i; 417 418 err = unregister_filesystem(&coda_fs_type); 419 if ( err != 0 ) { 420 printk("coda: failed to unregister filesystem\n"); 421 } 422 for (i = 0; i < MAX_CODADEVS; i++) 423 device_destroy(coda_psdev_class, MKDEV(CODA_PSDEV_MAJOR, i)); 424 class_destroy(coda_psdev_class); 425 unregister_chrdev(CODA_PSDEV_MAJOR, "coda"); 426 coda_sysctl_clean(); 427 coda_destroy_inodecache(); 428 } 429 430 module_init(init_coda); 431 module_exit(exit_coda); 432 433