Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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@redhat.com> |
| 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/slab.h> |
| 26 | #include <linux/ioport.h> |
| 27 | #include <linux/fcntl.h> |
| 28 | #include <linux/delay.h> |
| 29 | #include <linux/skbuff.h> |
| 30 | #include <linux/proc_fs.h> |
| 31 | #include <linux/devfs_fs_kernel.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 | #include <linux/coda_proc.h> |
| 50 | |
| 51 | #define upc_free(r) kfree(r) |
| 52 | |
| 53 | /* |
| 54 | * Coda stuff |
| 55 | */ |
| 56 | extern struct file_system_type coda_fs_type; |
| 57 | |
| 58 | /* statistics */ |
| 59 | int coda_hard; /* allows signals during upcalls */ |
| 60 | unsigned long coda_timeout = 30; /* .. secs, then signals will dequeue */ |
| 61 | |
| 62 | |
| 63 | struct venus_comm coda_comms[MAX_CODADEVS]; |
gregkh@suse.de | 1db560a | 2005-03-23 10:02:26 -0800 | [diff] [blame] | 64 | static struct class *coda_psdev_class; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 65 | |
| 66 | /* |
| 67 | * Device operations |
| 68 | */ |
| 69 | |
| 70 | static unsigned int coda_psdev_poll(struct file *file, poll_table * wait) |
| 71 | { |
| 72 | struct venus_comm *vcp = (struct venus_comm *) file->private_data; |
| 73 | unsigned int mask = POLLOUT | POLLWRNORM; |
| 74 | |
| 75 | poll_wait(file, &vcp->vc_waitq, wait); |
| 76 | if (!list_empty(&vcp->vc_pending)) |
| 77 | mask |= POLLIN | POLLRDNORM; |
| 78 | |
| 79 | return mask; |
| 80 | } |
| 81 | |
| 82 | static int coda_psdev_ioctl(struct inode * inode, struct file * filp, |
| 83 | unsigned int cmd, unsigned long arg) |
| 84 | { |
| 85 | unsigned int data; |
| 86 | |
| 87 | switch(cmd) { |
| 88 | case CIOC_KERNEL_VERSION: |
| 89 | data = CODA_KERNEL_VERSION; |
| 90 | return put_user(data, (int __user *) arg); |
| 91 | default: |
| 92 | return -ENOTTY; |
| 93 | } |
| 94 | |
| 95 | return 0; |
| 96 | } |
| 97 | |
| 98 | /* |
| 99 | * Receive a message written by Venus to the psdev |
| 100 | */ |
| 101 | |
| 102 | static ssize_t coda_psdev_write(struct file *file, const char __user *buf, |
| 103 | size_t nbytes, loff_t *off) |
| 104 | { |
| 105 | struct venus_comm *vcp = (struct venus_comm *) file->private_data; |
| 106 | struct upc_req *req = NULL; |
| 107 | struct upc_req *tmp; |
| 108 | struct list_head *lh; |
| 109 | struct coda_in_hdr hdr; |
| 110 | ssize_t retval = 0, count = 0; |
| 111 | int error; |
| 112 | |
| 113 | /* Peek at the opcode, uniquefier */ |
| 114 | if (copy_from_user(&hdr, buf, 2 * sizeof(u_long))) |
| 115 | return -EFAULT; |
| 116 | |
| 117 | if (DOWNCALL(hdr.opcode)) { |
| 118 | struct super_block *sb = NULL; |
| 119 | union outputArgs *dcbuf; |
| 120 | int size = sizeof(*dcbuf); |
| 121 | |
| 122 | sb = vcp->vc_sb; |
| 123 | if ( !sb ) { |
| 124 | count = nbytes; |
| 125 | goto out; |
| 126 | } |
| 127 | |
| 128 | if ( nbytes < sizeof(struct coda_out_hdr) ) { |
| 129 | printk("coda_downcall opc %d uniq %d, not enough!\n", |
| 130 | hdr.opcode, hdr.unique); |
| 131 | count = nbytes; |
| 132 | goto out; |
| 133 | } |
| 134 | if ( nbytes > size ) { |
| 135 | printk("Coda: downcall opc %d, uniq %d, too much!", |
| 136 | hdr.opcode, hdr.unique); |
| 137 | nbytes = size; |
| 138 | } |
| 139 | CODA_ALLOC(dcbuf, union outputArgs *, nbytes); |
| 140 | if (copy_from_user(dcbuf, buf, nbytes)) { |
| 141 | CODA_FREE(dcbuf, nbytes); |
| 142 | retval = -EFAULT; |
| 143 | goto out; |
| 144 | } |
| 145 | |
| 146 | /* what downcall errors does Venus handle ? */ |
| 147 | lock_kernel(); |
| 148 | error = coda_downcall(hdr.opcode, dcbuf, sb); |
| 149 | unlock_kernel(); |
| 150 | |
| 151 | CODA_FREE(dcbuf, nbytes); |
| 152 | if (error) { |
| 153 | printk("psdev_write: coda_downcall error: %d\n", error); |
| 154 | retval = error; |
| 155 | goto out; |
| 156 | } |
| 157 | count = nbytes; |
| 158 | goto out; |
| 159 | } |
| 160 | |
| 161 | /* Look for the message on the processing queue. */ |
| 162 | lock_kernel(); |
| 163 | list_for_each(lh, &vcp->vc_processing) { |
| 164 | tmp = list_entry(lh, struct upc_req , uc_chain); |
| 165 | if (tmp->uc_unique == hdr.unique) { |
| 166 | req = tmp; |
| 167 | list_del(&req->uc_chain); |
| 168 | break; |
| 169 | } |
| 170 | } |
| 171 | unlock_kernel(); |
| 172 | |
| 173 | if (!req) { |
| 174 | printk("psdev_write: msg (%d, %d) not found\n", |
| 175 | hdr.opcode, hdr.unique); |
| 176 | retval = -ESRCH; |
| 177 | goto out; |
| 178 | } |
| 179 | |
| 180 | /* move data into response buffer. */ |
| 181 | if (req->uc_outSize < nbytes) { |
| 182 | printk("psdev_write: too much cnt: %d, cnt: %ld, opc: %d, uniq: %d.\n", |
| 183 | req->uc_outSize, (long)nbytes, hdr.opcode, hdr.unique); |
| 184 | nbytes = req->uc_outSize; /* don't have more space! */ |
| 185 | } |
| 186 | if (copy_from_user(req->uc_data, buf, nbytes)) { |
| 187 | req->uc_flags |= REQ_ABORT; |
| 188 | wake_up(&req->uc_sleep); |
| 189 | retval = -EFAULT; |
| 190 | goto out; |
| 191 | } |
| 192 | |
| 193 | /* adjust outsize. is this useful ?? */ |
| 194 | req->uc_outSize = nbytes; |
| 195 | req->uc_flags |= REQ_WRITE; |
| 196 | count = nbytes; |
| 197 | |
| 198 | /* Convert filedescriptor into a file handle */ |
| 199 | if (req->uc_opcode == CODA_OPEN_BY_FD) { |
| 200 | struct coda_open_by_fd_out *outp = |
| 201 | (struct coda_open_by_fd_out *)req->uc_data; |
| 202 | outp->fh = fget(outp->fd); |
| 203 | } |
| 204 | |
| 205 | wake_up(&req->uc_sleep); |
| 206 | out: |
| 207 | return(count ? count : retval); |
| 208 | } |
| 209 | |
| 210 | /* |
| 211 | * Read a message from the kernel to Venus |
| 212 | */ |
| 213 | |
| 214 | static ssize_t coda_psdev_read(struct file * file, char __user * buf, |
| 215 | size_t nbytes, loff_t *off) |
| 216 | { |
| 217 | DECLARE_WAITQUEUE(wait, current); |
| 218 | struct venus_comm *vcp = (struct venus_comm *) file->private_data; |
| 219 | struct upc_req *req; |
| 220 | ssize_t retval = 0, count = 0; |
| 221 | |
| 222 | if (nbytes == 0) |
| 223 | return 0; |
| 224 | |
| 225 | lock_kernel(); |
| 226 | |
| 227 | add_wait_queue(&vcp->vc_waitq, &wait); |
| 228 | set_current_state(TASK_INTERRUPTIBLE); |
| 229 | |
| 230 | while (list_empty(&vcp->vc_pending)) { |
| 231 | if (file->f_flags & O_NONBLOCK) { |
| 232 | retval = -EAGAIN; |
| 233 | break; |
| 234 | } |
| 235 | if (signal_pending(current)) { |
| 236 | retval = -ERESTARTSYS; |
| 237 | break; |
| 238 | } |
| 239 | schedule(); |
| 240 | } |
| 241 | |
| 242 | set_current_state(TASK_RUNNING); |
| 243 | remove_wait_queue(&vcp->vc_waitq, &wait); |
| 244 | |
| 245 | if (retval) |
| 246 | goto out; |
| 247 | |
| 248 | req = list_entry(vcp->vc_pending.next, struct upc_req,uc_chain); |
| 249 | list_del(&req->uc_chain); |
| 250 | |
| 251 | /* Move the input args into userspace */ |
| 252 | count = req->uc_inSize; |
| 253 | if (nbytes < req->uc_inSize) { |
| 254 | printk ("psdev_read: Venus read %ld bytes of %d in message\n", |
| 255 | (long)nbytes, req->uc_inSize); |
| 256 | count = nbytes; |
| 257 | } |
| 258 | |
| 259 | if (copy_to_user(buf, req->uc_data, count)) |
| 260 | retval = -EFAULT; |
| 261 | |
| 262 | /* If request was not a signal, enqueue and don't free */ |
| 263 | if (!(req->uc_flags & REQ_ASYNC)) { |
| 264 | req->uc_flags |= REQ_READ; |
| 265 | list_add(&(req->uc_chain), vcp->vc_processing.prev); |
| 266 | goto out; |
| 267 | } |
| 268 | |
| 269 | CODA_FREE(req->uc_data, sizeof(struct coda_in_hdr)); |
| 270 | upc_free(req); |
| 271 | out: |
| 272 | unlock_kernel(); |
| 273 | return (count ? count : retval); |
| 274 | } |
| 275 | |
| 276 | static int coda_psdev_open(struct inode * inode, struct file * file) |
| 277 | { |
| 278 | struct venus_comm *vcp; |
| 279 | int idx; |
| 280 | |
| 281 | lock_kernel(); |
| 282 | idx = iminor(inode); |
| 283 | if(idx >= MAX_CODADEVS) { |
| 284 | unlock_kernel(); |
| 285 | return -ENODEV; |
| 286 | } |
| 287 | |
| 288 | vcp = &coda_comms[idx]; |
| 289 | if(vcp->vc_inuse) { |
| 290 | unlock_kernel(); |
| 291 | return -EBUSY; |
| 292 | } |
| 293 | |
| 294 | if (!vcp->vc_inuse++) { |
| 295 | INIT_LIST_HEAD(&vcp->vc_pending); |
| 296 | INIT_LIST_HEAD(&vcp->vc_processing); |
| 297 | init_waitqueue_head(&vcp->vc_waitq); |
| 298 | vcp->vc_sb = NULL; |
| 299 | vcp->vc_seq = 0; |
| 300 | } |
| 301 | |
| 302 | file->private_data = vcp; |
| 303 | |
| 304 | unlock_kernel(); |
| 305 | return 0; |
| 306 | } |
| 307 | |
| 308 | |
| 309 | static int coda_psdev_release(struct inode * inode, struct file * file) |
| 310 | { |
| 311 | struct venus_comm *vcp = (struct venus_comm *) file->private_data; |
| 312 | struct upc_req *req, *tmp; |
| 313 | |
| 314 | lock_kernel(); |
| 315 | if ( !vcp->vc_inuse ) { |
| 316 | unlock_kernel(); |
| 317 | printk("psdev_release: Not open.\n"); |
| 318 | return -1; |
| 319 | } |
| 320 | |
| 321 | if (--vcp->vc_inuse) { |
| 322 | unlock_kernel(); |
| 323 | return 0; |
| 324 | } |
| 325 | |
| 326 | /* Wakeup clients so they can return. */ |
| 327 | list_for_each_entry_safe(req, tmp, &vcp->vc_pending, uc_chain) { |
| 328 | /* Async requests need to be freed here */ |
| 329 | if (req->uc_flags & REQ_ASYNC) { |
| 330 | CODA_FREE(req->uc_data, sizeof(struct coda_in_hdr)); |
| 331 | upc_free(req); |
| 332 | continue; |
| 333 | } |
| 334 | req->uc_flags |= REQ_ABORT; |
| 335 | wake_up(&req->uc_sleep); |
| 336 | } |
| 337 | |
| 338 | list_for_each_entry(req, &vcp->vc_processing, uc_chain) { |
| 339 | req->uc_flags |= REQ_ABORT; |
| 340 | wake_up(&req->uc_sleep); |
| 341 | } |
| 342 | |
| 343 | unlock_kernel(); |
| 344 | return 0; |
| 345 | } |
| 346 | |
| 347 | |
| 348 | static struct file_operations coda_psdev_fops = { |
| 349 | .owner = THIS_MODULE, |
| 350 | .read = coda_psdev_read, |
| 351 | .write = coda_psdev_write, |
| 352 | .poll = coda_psdev_poll, |
| 353 | .ioctl = coda_psdev_ioctl, |
| 354 | .open = coda_psdev_open, |
| 355 | .release = coda_psdev_release, |
| 356 | }; |
| 357 | |
| 358 | static int init_coda_psdev(void) |
| 359 | { |
| 360 | int i, err = 0; |
| 361 | if (register_chrdev(CODA_PSDEV_MAJOR, "coda", &coda_psdev_fops)) { |
| 362 | printk(KERN_ERR "coda_psdev: unable to get major %d\n", |
| 363 | CODA_PSDEV_MAJOR); |
| 364 | return -EIO; |
| 365 | } |
gregkh@suse.de | 1db560a | 2005-03-23 10:02:26 -0800 | [diff] [blame] | 366 | coda_psdev_class = class_create(THIS_MODULE, "coda"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 367 | if (IS_ERR(coda_psdev_class)) { |
| 368 | err = PTR_ERR(coda_psdev_class); |
| 369 | goto out_chrdev; |
| 370 | } |
| 371 | devfs_mk_dir ("coda"); |
| 372 | for (i = 0; i < MAX_CODADEVS; i++) { |
gregkh@suse.de | 1db560a | 2005-03-23 10:02:26 -0800 | [diff] [blame] | 373 | class_device_create(coda_psdev_class, MKDEV(CODA_PSDEV_MAJOR,i), |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 374 | NULL, "cfs%d", i); |
| 375 | err = devfs_mk_cdev(MKDEV(CODA_PSDEV_MAJOR, i), |
| 376 | S_IFCHR|S_IRUSR|S_IWUSR, "coda/%d", i); |
| 377 | if (err) |
| 378 | goto out_class; |
| 379 | } |
| 380 | coda_sysctl_init(); |
| 381 | goto out; |
| 382 | |
| 383 | out_class: |
| 384 | for (i = 0; i < MAX_CODADEVS; i++) |
gregkh@suse.de | 1db560a | 2005-03-23 10:02:26 -0800 | [diff] [blame] | 385 | class_device_destroy(coda_psdev_class, MKDEV(CODA_PSDEV_MAJOR, i)); |
| 386 | class_destroy(coda_psdev_class); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 387 | out_chrdev: |
| 388 | unregister_chrdev(CODA_PSDEV_MAJOR, "coda"); |
| 389 | out: |
| 390 | return err; |
| 391 | } |
| 392 | |
| 393 | |
| 394 | MODULE_AUTHOR("Peter J. Braam <braam@cs.cmu.edu>"); |
| 395 | MODULE_LICENSE("GPL"); |
| 396 | |
| 397 | extern int coda_init_inodecache(void); |
| 398 | extern void coda_destroy_inodecache(void); |
| 399 | static int __init init_coda(void) |
| 400 | { |
| 401 | int status; |
| 402 | int i; |
| 403 | printk(KERN_INFO "Coda Kernel/Venus communications, " |
| 404 | #ifdef CONFIG_CODA_FS_OLD_API |
| 405 | "v5.3.20" |
| 406 | #else |
| 407 | "v6.0.0" |
| 408 | #endif |
| 409 | ", coda@cs.cmu.edu\n"); |
| 410 | |
| 411 | status = coda_init_inodecache(); |
| 412 | if (status) |
| 413 | goto out2; |
| 414 | status = init_coda_psdev(); |
| 415 | if ( status ) { |
| 416 | printk("Problem (%d) in init_coda_psdev\n", status); |
| 417 | goto out1; |
| 418 | } |
| 419 | |
| 420 | status = register_filesystem(&coda_fs_type); |
| 421 | if (status) { |
| 422 | printk("coda: failed to register filesystem!\n"); |
| 423 | goto out; |
| 424 | } |
| 425 | return 0; |
| 426 | out: |
| 427 | for (i = 0; i < MAX_CODADEVS; i++) { |
gregkh@suse.de | 1db560a | 2005-03-23 10:02:26 -0800 | [diff] [blame] | 428 | class_device_destroy(coda_psdev_class, MKDEV(CODA_PSDEV_MAJOR, i)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 429 | devfs_remove("coda/%d", i); |
| 430 | } |
gregkh@suse.de | 1db560a | 2005-03-23 10:02:26 -0800 | [diff] [blame] | 431 | class_destroy(coda_psdev_class); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 432 | devfs_remove("coda"); |
| 433 | unregister_chrdev(CODA_PSDEV_MAJOR, "coda"); |
| 434 | coda_sysctl_clean(); |
| 435 | out1: |
| 436 | coda_destroy_inodecache(); |
| 437 | out2: |
| 438 | return status; |
| 439 | } |
| 440 | |
| 441 | static void __exit exit_coda(void) |
| 442 | { |
| 443 | int err, i; |
| 444 | |
| 445 | err = unregister_filesystem(&coda_fs_type); |
| 446 | if ( err != 0 ) { |
| 447 | printk("coda: failed to unregister filesystem\n"); |
| 448 | } |
| 449 | for (i = 0; i < MAX_CODADEVS; i++) { |
gregkh@suse.de | 1db560a | 2005-03-23 10:02:26 -0800 | [diff] [blame] | 450 | class_device_destroy(coda_psdev_class, MKDEV(CODA_PSDEV_MAJOR, i)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 451 | devfs_remove("coda/%d", i); |
| 452 | } |
gregkh@suse.de | 1db560a | 2005-03-23 10:02:26 -0800 | [diff] [blame] | 453 | class_destroy(coda_psdev_class); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 454 | devfs_remove("coda"); |
| 455 | unregister_chrdev(CODA_PSDEV_MAJOR, "coda"); |
| 456 | coda_sysctl_clean(); |
| 457 | coda_destroy_inodecache(); |
| 458 | } |
| 459 | |
| 460 | module_init(init_coda); |
| 461 | module_exit(exit_coda); |
| 462 | |