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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 | /* * An implementation of a loadable kernel mode driver providing * multiple kernel/user space bidirectional communications links. * * Author: Alan Cox <alan@cymru.net> * * 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/sched.h> #include <linux/lp.h> #include <linux/malloc.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/poll.h> #include <linux/init.h> #include <linux/list.h> #include <asm/io.h> #include <asm/segment.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_cache.h> #include <linux/coda_proc.h> /* * Coda stuff */ extern struct file_system_type coda_fs_type; extern int init_coda_fs(void); /* statistics */ int coda_hard = 0; /* allows signals during upcalls */ unsigned long coda_timeout = 30; /* .. secs, then signals will dequeue */ struct coda_sb_info coda_super_info; struct venus_comm coda_upc_comm; /* * Device operations */ static unsigned int coda_psdev_poll(struct file *file, poll_table * wait) { struct venus_comm *vcp = &coda_upc_comm; unsigned int mask = POLLOUT | POLLWRNORM; poll_wait(file, &(vcp->vc_waitq), wait); if (!list_empty(&vcp->vc_pending)) mask |= POLLIN | POLLRDNORM; return mask; } /* * Receive a message written by Venus to the psdev */ static ssize_t coda_psdev_write(struct file *file, const char *buf, size_t count, loff_t *off) { struct venus_comm *vcp = &coda_upc_comm; struct upc_req *req = NULL; struct upc_req *tmp; struct list_head *lh; struct coda_in_hdr hdr; int error; if ( !coda_upc_comm.vc_pid ) return -EIO; /* Peek at the opcode, uniquefier */ if (copy_from_user(&hdr, buf, 2 * sizeof(u_long))) return -EFAULT; CDEBUG(D_PSDEV, "(process,opc,uniq)=(%d,%ld,%ld), count %d\n", current->pid, hdr.opcode, hdr.unique, count); if (DOWNCALL(hdr.opcode)) { struct super_block *sb = NULL; union outputArgs *dcbuf; int size = sizeof(*dcbuf); sb = coda_super_info.sbi_sb; if ( !sb ) { printk("coda_psdev_write: downcall, no SB!\n"); return count; } CDEBUG(D_PSDEV, "handling downcall\n"); if ( count < sizeof(struct coda_out_hdr) ) { printk("coda_downcall opc %ld uniq %ld, not enough!\n", hdr.opcode, hdr.unique); return count; } CODA_ALLOC(dcbuf, union outputArgs *, size); if ( count > size ) { printk("Coda: downcall opc %ld, uniq %ld, too much!", hdr.opcode, hdr.unique); count = size; } if (copy_from_user(dcbuf, buf, count)) return -EFAULT; /* what downcall errors does Venus handle ? */ error = coda_downcall(hdr.opcode, dcbuf, sb); if ( error) { printk("psdev_write: coda_downcall error: %d\n", error); return 0; } CODA_FREE(dcbuf, size); return count; } /* Look for the message on the processing queue. */ lh = &vcp->vc_processing; while ( (lh = lh->next) != &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); CDEBUG(D_PSDEV,"Eureka: uniq %ld on queue!\n", hdr.unique); break; } } if (!req) { printk("psdev_write: msg (%ld, %ld) not found\n", hdr.opcode, hdr.unique); return(-ESRCH); } /* move data into response buffer. */ if (req->uc_outSize < count) { printk("psdev_write: too much cnt: %d, cnt: %d, opc: %ld, uniq: %ld.\n", req->uc_outSize, count, hdr.opcode, hdr.unique); count = req->uc_outSize; /* don't have more space! */ } if (copy_from_user(req->uc_data, buf, count)) return -EFAULT; /* adjust outsize. is this usefull ?? */ req->uc_outSize = count; req->uc_flags |= REQ_WRITE; CDEBUG(D_PSDEV, "Found! Count %d for (opc,uniq)=(%ld,%ld), upc_req at %x\n", count, hdr.opcode, hdr.unique, (int)&req); wake_up(&req->uc_sleep); return(count); } /* * Read a message from the kernel to Venus */ static ssize_t coda_psdev_read(struct file * file, char * buf, size_t count, loff_t *off) { struct venus_comm *vcp = &coda_upc_comm; struct upc_req *req; int result = count ; CDEBUG(D_PSDEV, "count %d\n", count); if (list_empty(&(vcp->vc_pending))) { return -1; } req = list_entry((vcp->vc_pending.next), struct upc_req, uc_chain); list_del(&(req->uc_chain)); /* Move the input args into userspace */ if (req->uc_inSize <= count) result = req->uc_inSize; if (count < req->uc_inSize) { printk ("psdev_read: Venus read %d bytes of %d in message\n", count, req->uc_inSize); } if ( copy_to_user(buf, req->uc_data, result)) return -EFAULT; /* If request was a signal, don't enqueue */ if (req->uc_opcode == CODA_SIGNAL) { CDEBUG(D_PSDEV, "vcread: signal msg (%d, %d)\n", req->uc_opcode, req->uc_unique); CODA_FREE(req->uc_data, sizeof(struct coda_in_hdr)); CODA_FREE(req, sizeof(struct upc_req)); return count; } req->uc_flags |= REQ_READ; list_add(&(req->uc_chain), vcp->vc_processing.prev); return result; } static int coda_psdev_open(struct inode * inode, struct file * file) { struct venus_comm *vcp = &coda_upc_comm; ENTRY; /* first opener: must be lento. Initialize & take its pid */ if ( file->f_flags == O_RDWR ) { if ( vcp->vc_pid ) { printk("Venus pid already set to %d!!\n", vcp->vc_pid); return -1; } if ( vcp->vc_inuse ) { printk("psdev_open: Cannot O_RDWR while open.\n"); return -1; } } vcp->vc_inuse++; MOD_INC_USE_COUNT; if ( file->f_flags == O_RDWR ) { vcp->vc_pid = current->pid; vcp->vc_seq = 0; INIT_LIST_HEAD(&vcp->vc_pending); INIT_LIST_HEAD(&vcp->vc_processing); } CDEBUG(D_PSDEV, "inuse: %d, vc_pid %d, caller %d\n", vcp->vc_inuse, vcp->vc_pid, current->pid); EXIT; return 0; } static int coda_psdev_release(struct inode * inode, struct file * file) { struct venus_comm *vcp = &coda_upc_comm; struct upc_req *req; struct list_head *lh, *next; ENTRY; if ( !vcp->vc_inuse ) { printk("psdev_release: Not open.\n"); return -1; } vcp->vc_inuse--; MOD_DEC_USE_COUNT; CDEBUG(D_PSDEV, "inuse: %d, vc_pid %d, caller %d\n", vcp->vc_inuse, vcp->vc_pid, current->pid); if ( vcp->vc_pid != current->pid ) { return 0; } vcp->vc_pid = 0; /* Wakeup clients so they can return. */ CDEBUG(D_PSDEV, "wake up pending clients\n"); lh = vcp->vc_pending.next; next = lh; while ( (lh = next) != &vcp->vc_pending) { next = lh->next; req = list_entry(lh, struct upc_req, 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)); CODA_FREE(req, (u_int)sizeof(struct upc_req)); continue; } wake_up(&req->uc_sleep); } lh = &vcp->vc_processing; CDEBUG(D_PSDEV, "wake up processing clients\n"); while ( (lh = lh->next) != &vcp->vc_processing) { req = list_entry(lh, struct upc_req, uc_chain); wake_up(&req->uc_sleep); } CDEBUG(D_PSDEV, "Done.\n"); EXIT; return 0; } static struct file_operations coda_psdev_fops = { NULL, /* llseek */ coda_psdev_read, /* read */ coda_psdev_write, /* write */ NULL, /* coda_psdev_readdir */ coda_psdev_poll, /* poll */ NULL, /* ioctl */ NULL, /* coda_psdev_mmap */ coda_psdev_open, /* open */ NULL, coda_psdev_release, /* release */ NULL, /* fsync */ NULL, /* fasync */ NULL, /* check_media_change */ NULL, /* revalidate */ NULL /* lock */ }; __initfunc(int init_coda(void)) { int status; printk(KERN_INFO "Coda Kernel/Venus communications, v4.6.0, braam@cs.cmu.edu\n"); status = init_coda_psdev(); if ( status ) { printk("Problem (%d) in init_coda_psdev\n", status); return status; } status = init_coda_fs(); if (status) { printk("coda: failed in init_coda_fs!\n"); } return status; } int init_coda_psdev(void) { if(register_chrdev(CODA_PSDEV_MAJOR,"coda_psdev", &coda_psdev_fops)) { printk(KERN_ERR "coda_psdev: unable to get major %d\n", CODA_PSDEV_MAJOR); return -EIO; } memset(&coda_upc_comm, 0, sizeof(coda_upc_comm)); memset(&coda_super_info, 0, sizeof(coda_super_info)); coda_sysctl_init(); return 0; } #ifdef MODULE MODULE_AUTHOR("Peter J. Braam <braam@cs.cmu.edu>"); int init_module(void) { int status; printk(KERN_INFO "Coda Kernel/Venus communications (module), v5.0-pre1, braam@cs.cmu.edu.\n"); status = init_coda_psdev(); if ( status ) { printk("Problem (%d) in init_coda_psdev\n", status); return status; } status = init_coda_fs(); if (status) { printk("coda: failed in init_coda_fs!\n"); } return status; } void cleanup_module(void) { int err; ENTRY; if ( (err = unregister_filesystem(&coda_fs_type)) != 0 ) { printk("coda: failed to unregister filesystem\n"); } unregister_chrdev(CODA_PSDEV_MAJOR,"coda_psdev"); coda_sysctl_clean(); } #endif |