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 int coda_psdev_ioctl(struct inode * inode, struct file * filp, 77 unsigned int cmd, unsigned long arg) 78 { 79 unsigned int data; 80 81 switch(cmd) { 82 case CIOC_KERNEL_VERSION: 83 data = CODA_KERNEL_VERSION; 84 return put_user(data, (int __user *) arg); 85 default: 86 return -ENOTTY; 87 } 88 89 return 0; 90 } 91 92 /* 93 * Receive a message written by Venus to the psdev 94 */ 95 96 static ssize_t coda_psdev_write(struct file *file, const char __user *buf, 97 size_t nbytes, loff_t *off) 98 { 99 struct venus_comm *vcp = (struct venus_comm *) file->private_data; 100 struct upc_req *req = NULL; 101 struct upc_req *tmp; 102 struct list_head *lh; 103 struct coda_in_hdr hdr; 104 ssize_t retval = 0, count = 0; 105 int error; 106 107 /* Peek at the opcode, uniquefier */ 108 if (copy_from_user(&hdr, buf, 2 * sizeof(u_long))) 109 return -EFAULT; 110 111 if (DOWNCALL(hdr.opcode)) { 112 struct super_block *sb = NULL; 113 union outputArgs *dcbuf; 114 int size = sizeof(*dcbuf); 115 116 sb = vcp->vc_sb; 117 if ( !sb ) { 118 count = nbytes; 119 goto out; 120 } 121 122 if ( nbytes < sizeof(struct coda_out_hdr) ) { 123 printk("coda_downcall opc %d uniq %d, not enough!\n", 124 hdr.opcode, hdr.unique); 125 count = nbytes; 126 goto out; 127 } 128 if ( nbytes > size ) { 129 printk("Coda: downcall opc %d, uniq %d, too much!", 130 hdr.opcode, hdr.unique); 131 nbytes = size; 132 } 133 CODA_ALLOC(dcbuf, union outputArgs *, nbytes); 134 if (copy_from_user(dcbuf, buf, nbytes)) { 135 CODA_FREE(dcbuf, nbytes); 136 retval = -EFAULT; 137 goto out; 138 } 139 140 /* what downcall errors does Venus handle ? */ 141 lock_kernel(); 142 error = coda_downcall(hdr.opcode, dcbuf, sb); 143 unlock_kernel(); 144 145 CODA_FREE(dcbuf, nbytes); 146 if (error) { 147 printk("psdev_write: coda_downcall error: %d\n", error); 148 retval = error; 149 goto out; 150 } 151 count = nbytes; 152 goto out; 153 } 154 155 /* Look for the message on the processing queue. */ 156 lock_kernel(); 157 list_for_each(lh, &vcp->vc_processing) { 158 tmp = list_entry(lh, struct upc_req , uc_chain); 159 if (tmp->uc_unique == hdr.unique) { 160 req = tmp; 161 list_del(&req->uc_chain); 162 break; 163 } 164 } 165 unlock_kernel(); 166 167 if (!req) { 168 printk("psdev_write: msg (%d, %d) not found\n", 169 hdr.opcode, hdr.unique); 170 retval = -ESRCH; 171 goto out; 172 } 173 174 /* move data into response buffer. */ 175 if (req->uc_outSize < nbytes) { 176 printk("psdev_write: too much cnt: %d, cnt: %ld, opc: %d, uniq: %d.\n", 177 req->uc_outSize, (long)nbytes, hdr.opcode, hdr.unique); 178 nbytes = req->uc_outSize; /* don't have more space! */ 179 } 180 if (copy_from_user(req->uc_data, buf, nbytes)) { 181 req->uc_flags |= REQ_ABORT; 182 wake_up(&req->uc_sleep); 183 retval = -EFAULT; 184 goto out; 185 } 186 187 /* adjust outsize. is this useful ?? */ 188 req->uc_outSize = nbytes; 189 req->uc_flags |= REQ_WRITE; 190 count = nbytes; 191 192 /* Convert filedescriptor into a file handle */ 193 if (req->uc_opcode == CODA_OPEN_BY_FD) { 194 struct coda_open_by_fd_out *outp = 195 (struct coda_open_by_fd_out *)req->uc_data; 196 if (!outp->oh.result) 197 outp->fh = fget(outp->fd); 198 } 199 200 wake_up(&req->uc_sleep); 201 out: 202 return(count ? count : retval); 203 } 204 205 /* 206 * Read a message from the kernel to Venus 207 */ 208 209 static ssize_t coda_psdev_read(struct file * file, char __user * buf, 210 size_t nbytes, loff_t *off) 211 { 212 DECLARE_WAITQUEUE(wait, current); 213 struct venus_comm *vcp = (struct venus_comm *) file->private_data; 214 struct upc_req *req; 215 ssize_t retval = 0, count = 0; 216 217 if (nbytes == 0) 218 return 0; 219 220 lock_kernel(); 221 222 add_wait_queue(&vcp->vc_waitq, &wait); 223 set_current_state(TASK_INTERRUPTIBLE); 224 225 while (list_empty(&vcp->vc_pending)) { 226 if (file->f_flags & O_NONBLOCK) { 227 retval = -EAGAIN; 228 break; 229 } 230 if (signal_pending(current)) { 231 retval = -ERESTARTSYS; 232 break; 233 } 234 schedule(); 235 } 236 237 set_current_state(TASK_RUNNING); 238 remove_wait_queue(&vcp->vc_waitq, &wait); 239 240 if (retval) 241 goto out; 242 243 req = list_entry(vcp->vc_pending.next, struct upc_req,uc_chain); 244 list_del(&req->uc_chain); 245 246 /* Move the input args into userspace */ 247 count = req->uc_inSize; 248 if (nbytes < req->uc_inSize) { 249 printk ("psdev_read: Venus read %ld bytes of %d in message\n", 250 (long)nbytes, req->uc_inSize); 251 count = nbytes; 252 } 253 254 if (copy_to_user(buf, req->uc_data, count)) 255 retval = -EFAULT; 256 257 /* If request was not a signal, enqueue and don't free */ 258 if (!(req->uc_flags & REQ_ASYNC)) { 259 req->uc_flags |= REQ_READ; 260 list_add_tail(&(req->uc_chain), &vcp->vc_processing); 261 goto out; 262 } 263 264 CODA_FREE(req->uc_data, sizeof(struct coda_in_hdr)); 265 kfree(req); 266 out: 267 unlock_kernel(); 268 return (count ? count : retval); 269 } 270 271 static int coda_psdev_open(struct inode * inode, struct file * file) 272 { 273 struct venus_comm *vcp; 274 int idx, err; 275 276 idx = iminor(inode); 277 if (idx < 0 || idx >= MAX_CODADEVS) 278 return -ENODEV; 279 280 lock_kernel(); 281 282 err = -EBUSY; 283 vcp = &coda_comms[idx]; 284 if (!vcp->vc_inuse) { 285 vcp->vc_inuse++; 286 287 INIT_LIST_HEAD(&vcp->vc_pending); 288 INIT_LIST_HEAD(&vcp->vc_processing); 289 init_waitqueue_head(&vcp->vc_waitq); 290 vcp->vc_sb = NULL; 291 vcp->vc_seq = 0; 292 293 file->private_data = vcp; 294 err = 0; 295 } 296 297 unlock_kernel(); 298 return err; 299 } 300 301 302 static int coda_psdev_release(struct inode * inode, struct file * file) 303 { 304 struct venus_comm *vcp = (struct venus_comm *) file->private_data; 305 struct upc_req *req, *tmp; 306 307 if (!vcp || !vcp->vc_inuse ) { 308 printk("psdev_release: Not open.\n"); 309 return -1; 310 } 311 312 lock_kernel(); 313 314 /* Wakeup clients so they can return. */ 315 list_for_each_entry_safe(req, tmp, &vcp->vc_pending, uc_chain) { 316 list_del(&req->uc_chain); 317 318 /* Async requests need to be freed here */ 319 if (req->uc_flags & REQ_ASYNC) { 320 CODA_FREE(req->uc_data, sizeof(struct coda_in_hdr)); 321 kfree(req); 322 continue; 323 } 324 req->uc_flags |= REQ_ABORT; 325 wake_up(&req->uc_sleep); 326 } 327 328 list_for_each_entry_safe(req, tmp, &vcp->vc_processing, uc_chain) { 329 list_del(&req->uc_chain); 330 331 req->uc_flags |= REQ_ABORT; 332 wake_up(&req->uc_sleep); 333 } 334 335 file->private_data = NULL; 336 vcp->vc_inuse--; 337 unlock_kernel(); 338 return 0; 339 } 340 341 342 static const struct file_operations coda_psdev_fops = { 343 .owner = THIS_MODULE, 344 .read = coda_psdev_read, 345 .write = coda_psdev_write, 346 .poll = coda_psdev_poll, 347 .ioctl = coda_psdev_ioctl, 348 .open = coda_psdev_open, 349 .release = coda_psdev_release, 350 }; 351 352 static int init_coda_psdev(void) 353 { 354 int i, err = 0; 355 if (register_chrdev(CODA_PSDEV_MAJOR, "coda", &coda_psdev_fops)) { 356 printk(KERN_ERR "coda_psdev: unable to get major %d\n", 357 CODA_PSDEV_MAJOR); 358 return -EIO; 359 } 360 coda_psdev_class = class_create(THIS_MODULE, "coda"); 361 if (IS_ERR(coda_psdev_class)) { 362 err = PTR_ERR(coda_psdev_class); 363 goto out_chrdev; 364 } 365 for (i = 0; i < MAX_CODADEVS; i++) 366 device_create(coda_psdev_class, NULL, 367 MKDEV(CODA_PSDEV_MAJOR, i), NULL, "cfs%d", i); 368 coda_sysctl_init(); 369 goto out; 370 371 out_chrdev: 372 unregister_chrdev(CODA_PSDEV_MAJOR, "coda"); 373 out: 374 return err; 375 } 376 377 MODULE_AUTHOR("Jan Harkes, Peter J. Braam"); 378 MODULE_DESCRIPTION("Coda Distributed File System VFS interface"); 379 MODULE_ALIAS_CHARDEV_MAJOR(CODA_PSDEV_MAJOR); 380 MODULE_LICENSE("GPL"); 381 MODULE_VERSION("6.6"); 382 383 static int __init init_coda(void) 384 { 385 int status; 386 int i; 387 388 status = coda_init_inodecache(); 389 if (status) 390 goto out2; 391 status = init_coda_psdev(); 392 if ( status ) { 393 printk("Problem (%d) in init_coda_psdev\n", status); 394 goto out1; 395 } 396 397 status = register_filesystem(&coda_fs_type); 398 if (status) { 399 printk("coda: failed to register filesystem!\n"); 400 goto out; 401 } 402 return 0; 403 out: 404 for (i = 0; i < MAX_CODADEVS; i++) 405 device_destroy(coda_psdev_class, MKDEV(CODA_PSDEV_MAJOR, i)); 406 class_destroy(coda_psdev_class); 407 unregister_chrdev(CODA_PSDEV_MAJOR, "coda"); 408 coda_sysctl_clean(); 409 out1: 410 coda_destroy_inodecache(); 411 out2: 412 return status; 413 } 414 415 static void __exit exit_coda(void) 416 { 417 int err, i; 418 419 err = unregister_filesystem(&coda_fs_type); 420 if ( err != 0 ) { 421 printk("coda: failed to unregister filesystem\n"); 422 } 423 for (i = 0; i < MAX_CODADEVS; i++) 424 device_destroy(coda_psdev_class, MKDEV(CODA_PSDEV_MAJOR, i)); 425 class_destroy(coda_psdev_class); 426 unregister_chrdev(CODA_PSDEV_MAJOR, "coda"); 427 coda_sysctl_clean(); 428 coda_destroy_inodecache(); 429 } 430 431 module_init(init_coda); 432 module_exit(exit_coda); 433 434