Mercurial > hg > Members > anatofuz > CbC_xv6
annotate src/sysfile.cbc @ 91:b5ddf6fb0a6d
use CbCFile instead of File struct Interface
| author | anatofuz <anatofuz@cr.ie.u-ryukyu.ac.jp> |
|---|---|
| date | Fri, 18 Oct 2019 20:39:36 +0900 |
| parents | f38d8d39d617 |
| children | bc5bcfd2f6d6 |
| rev | line source |
|---|---|
| 0 | 1 // |
| 2 // File-system system calls. | |
| 3 // Mostly argument checking, since we don't trust | |
| 4 // user code, and calls into file.c and fs.c. | |
| 5 // | |
| 6 | |
| 7 #include "types.h" | |
| 8 #include "defs.h" | |
| 9 #include "param.h" | |
| 10 #include "stat.h" | |
| 11 #include "mmu.h" | |
| 12 #include "proc.h" | |
| 13 #include "fs.h" | |
| 14 #include "file.h" | |
| 15 #include "fcntl.h" | |
| 16 | |
|
91
b5ddf6fb0a6d
use CbCFile instead of File struct Interface
anatofuz <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
88
diff
changeset
|
17 #interface "CbCFile.h" |
|
b5ddf6fb0a6d
use CbCFile instead of File struct Interface
anatofuz <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
88
diff
changeset
|
18 |
| 52 | 19 #define __ncode __code |
| 20 | |
| 0 | 21 // Fetch the nth word-sized system call argument as a file descriptor |
| 22 // and return both the descriptor and the corresponding struct file. | |
| 23 static int argfd(int n, int *pfd, struct file **pf) | |
| 24 { | |
| 25 int fd; | |
| 26 struct file *f; | |
| 27 | |
| 28 if(argint(n, &fd) < 0) { | |
| 29 return -1; | |
| 30 } | |
| 31 | |
| 32 if(fd < 0 || fd >= NOFILE || (f=proc->ofile[fd]) == 0) { | |
| 33 return -1; | |
| 34 } | |
| 35 | |
| 36 if(pfd) { | |
| 37 *pfd = fd; | |
| 38 } | |
| 39 | |
| 40 if(pf) { | |
| 41 *pf = f; | |
| 42 } | |
| 43 | |
| 44 return 0; | |
| 45 } | |
| 46 | |
| 47 // Allocate a file descriptor for the given file. | |
| 48 // Takes over file reference from caller on success. | |
| 49 static int fdalloc(struct file *f) | |
| 50 { | |
| 51 int fd; | |
| 52 | |
| 53 for(fd = 0; fd < NOFILE; fd++){ | |
| 54 if(proc->ofile[fd] == 0){ | |
| 55 proc->ofile[fd] = f; | |
| 56 return fd; | |
| 57 } | |
| 58 } | |
| 59 | |
| 60 return -1; | |
| 61 } | |
| 62 | |
| 63 int sys_dup(void) | |
| 64 { | |
| 65 struct file *f; | |
| 66 int fd; | |
| 67 | |
| 68 if(argfd(0, 0, &f) < 0) { | |
| 69 return -1; | |
| 70 } | |
| 71 | |
| 72 if((fd=fdalloc(f)) < 0) { | |
| 73 return -1; | |
| 74 } | |
| 75 | |
| 76 filedup(f); | |
| 77 | |
| 78 return fd; | |
| 79 } | |
| 80 | |
| 52 | 81 __ncode cbc_read(__code (*next)(int ret)){ |
| 24 | 82 struct file *f; |
| 83 int n; | |
| 84 char *p; | |
| 85 | |
| 86 if(argfd(0, 0, &f) < 0 || argint(2, &n) < 0 || argptr(1, &p, n) < 0) { | |
| 87 goto next(-1); | |
| 88 } | |
| 89 goto cbc_fileread(f, p, n, next); | |
| 90 } | |
| 91 | |
|
91
b5ddf6fb0a6d
use CbCFile instead of File struct Interface
anatofuz <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
88
diff
changeset
|
92 struct CbCFile* initial_cbc_file(struct Context* cbc_context) { |
|
b5ddf6fb0a6d
use CbCFile instead of File struct Interface
anatofuz <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
88
diff
changeset
|
93 struct CbCFile* cbc_file = new CbCFile(); |
|
b5ddf6fb0a6d
use CbCFile instead of File struct Interface
anatofuz <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
88
diff
changeset
|
94 cbc_file->read = C_cbc_fileread; |
|
b5ddf6fb0a6d
use CbCFile instead of File struct Interface
anatofuz <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
88
diff
changeset
|
95 return cbc_file; |
|
b5ddf6fb0a6d
use CbCFile instead of File struct Interface
anatofuz <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
88
diff
changeset
|
96 } |
|
b5ddf6fb0a6d
use CbCFile instead of File struct Interface
anatofuz <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
88
diff
changeset
|
97 |
|
b5ddf6fb0a6d
use CbCFile instead of File struct Interface
anatofuz <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
88
diff
changeset
|
98 __code file_read(struct file *f, char *p, int n, __code next(...)){ |
| 88 | 99 goto cbc_fileread(f, p, n, next); |
| 100 } | |
| 101 | |
|
91
b5ddf6fb0a6d
use CbCFile instead of File struct Interface
anatofuz <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
88
diff
changeset
|
102 __code file_read_stub(struct Context* cbc_context, __code next(...)){ |
|
b5ddf6fb0a6d
use CbCFile instead of File struct Interface
anatofuz <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
88
diff
changeset
|
103 struct CbCFile* cbc_file = initial_cbc_file(cbc_context); |
| 88 | 104 struct file *f; |
| 105 int n; | |
| 106 char *p; | |
| 107 if(argfd(0, 0, &f) < 0 || argint(2, &n) < 0 || argptr(1, &p, n) < 0) { | |
| 108 goto next(-1); | |
| 109 } | |
|
91
b5ddf6fb0a6d
use CbCFile instead of File struct Interface
anatofuz <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
88
diff
changeset
|
110 goto file_read(cbc_context,f, p, n, next); |
| 88 | 111 } |
| 112 | |
| 0 | 113 int sys_read(void) |
| 114 { | |
| 115 struct file *f; | |
| 116 int n; | |
| 117 char *p; | |
| 118 | |
| 119 if(argfd(0, 0, &f) < 0 || argint(2, &n) < 0 || argptr(1, &p, n) < 0) { | |
| 120 return -1; | |
| 121 } | |
| 122 | |
| 123 return fileread(f, p, n); | |
| 124 } | |
| 125 | |
| 126 int sys_write(void) | |
| 127 { | |
| 128 struct file *f; | |
| 129 int n; | |
| 130 char *p; | |
| 131 | |
| 132 if(argfd(0, 0, &f) < 0 || argint(2, &n) < 0 || argptr(1, &p, n) < 0) { | |
| 133 return -1; | |
| 134 } | |
| 135 | |
| 136 return filewrite(f, p, n); | |
| 137 } | |
| 138 | |
| 139 int sys_close(void) | |
| 140 { | |
| 141 int fd; | |
| 142 struct file *f; | |
| 143 | |
| 144 if(argfd(0, &fd, &f) < 0) { | |
| 145 return -1; | |
| 146 } | |
| 147 | |
| 148 proc->ofile[fd] = 0; | |
| 149 fileclose(f); | |
| 150 | |
| 151 return 0; | |
| 152 } | |
| 153 | |
| 154 int sys_fstat(void) | |
| 155 { | |
| 156 struct file *f; | |
| 157 struct stat *st; | |
| 158 | |
| 159 if(argfd(0, 0, &f) < 0 || argptr(1, (void*)&st, sizeof(*st)) < 0) { | |
| 160 return -1; | |
| 161 } | |
| 162 | |
| 163 return filestat(f, st); | |
| 164 } | |
| 165 | |
| 166 // Create the path new as a link to the same inode as old. | |
| 167 int sys_link(void) | |
| 168 { | |
| 169 char name[DIRSIZ], *new, *old; | |
| 170 struct inode *dp, *ip; | |
| 171 | |
| 172 if(argstr(0, &old) < 0 || argstr(1, &new) < 0) { | |
| 173 return -1; | |
| 174 } | |
| 175 | |
| 176 if((ip = namei(old)) == 0) { | |
| 177 return -1; | |
| 178 } | |
| 179 | |
| 180 begin_trans(); | |
| 181 | |
| 182 ilock(ip); | |
| 183 | |
| 184 if(ip->type == T_DIR){ | |
| 185 iunlockput(ip); | |
| 186 commit_trans(); | |
| 187 return -1; | |
| 188 } | |
| 189 | |
| 190 ip->nlink++; | |
| 191 iupdate(ip); | |
| 192 iunlock(ip); | |
| 193 | |
| 194 if((dp = nameiparent(new, name)) == 0) { | |
| 195 goto bad; | |
| 196 } | |
| 197 | |
| 198 ilock(dp); | |
| 199 | |
| 200 if(dp->dev != ip->dev || dirlink(dp, name, ip->inum) < 0){ | |
| 201 iunlockput(dp); | |
| 202 goto bad; | |
| 203 } | |
| 204 | |
| 205 iunlockput(dp); | |
| 206 iput(ip); | |
| 207 | |
| 208 commit_trans(); | |
| 209 | |
| 210 return 0; | |
| 211 | |
| 212 bad: | |
| 213 ilock(ip); | |
| 214 ip->nlink--; | |
| 215 iupdate(ip); | |
| 216 iunlockput(ip); | |
| 217 commit_trans(); | |
| 218 return -1; | |
| 219 } | |
| 220 | |
| 221 // Is the directory dp empty except for "." and ".." ? | |
| 222 static int isdirempty(struct inode *dp) | |
| 223 { | |
| 224 int off; | |
| 225 struct dirent de; | |
| 226 | |
| 227 for(off=2*sizeof(de); off<dp->size; off+=sizeof(de)){ | |
| 228 if(readi(dp, (char*)&de, off, sizeof(de)) != sizeof(de)) { | |
| 229 panic("isdirempty: readi"); | |
| 230 } | |
| 231 | |
| 232 if(de.inum != 0) { | |
| 233 return 0; | |
| 234 } | |
| 235 } | |
| 236 return 1; | |
| 237 } | |
| 238 | |
| 239 //PAGEBREAK! | |
| 240 int sys_unlink(void) | |
| 241 { | |
| 242 struct inode *ip, *dp; | |
| 243 struct dirent de; | |
| 244 char name[DIRSIZ], *path; | |
| 245 uint off; | |
| 246 | |
| 247 if(argstr(0, &path) < 0) { | |
| 248 return -1; | |
| 249 } | |
| 250 | |
| 251 if((dp = nameiparent(path, name)) == 0) { | |
| 252 return -1; | |
| 253 } | |
| 254 | |
| 255 begin_trans(); | |
| 256 | |
| 257 ilock(dp); | |
| 258 | |
| 259 // Cannot unlink "." or "..". | |
| 260 if(namecmp(name, ".") == 0 || namecmp(name, "..") == 0) { | |
| 261 goto bad; | |
| 262 } | |
| 263 | |
| 264 if((ip = dirlookup(dp, name, &off)) == 0) { | |
| 265 goto bad; | |
| 266 } | |
| 267 | |
| 268 ilock(ip); | |
| 269 | |
| 270 if(ip->nlink < 1) { | |
| 271 panic("unlink: nlink < 1"); | |
| 272 } | |
| 273 | |
| 274 if(ip->type == T_DIR && !isdirempty(ip)){ | |
| 275 iunlockput(ip); | |
| 276 goto bad; | |
| 277 } | |
| 278 | |
| 279 memset(&de, 0, sizeof(de)); | |
| 280 | |
| 281 if(writei(dp, (char*)&de, off, sizeof(de)) != sizeof(de)) { | |
| 282 panic("unlink: writei"); | |
| 283 } | |
| 284 | |
| 285 if(ip->type == T_DIR){ | |
| 286 dp->nlink--; | |
| 287 iupdate(dp); | |
| 288 } | |
| 289 | |
| 290 iunlockput(dp); | |
| 291 | |
| 292 ip->nlink--; | |
| 293 iupdate(ip); | |
| 294 iunlockput(ip); | |
| 295 | |
| 296 commit_trans(); | |
| 297 | |
| 298 return 0; | |
| 299 | |
| 300 bad: | |
| 301 iunlockput(dp); | |
| 302 commit_trans(); | |
| 303 return -1; | |
| 304 } | |
| 305 | |
| 306 static struct inode* create(char *path, short type, short major, short minor) | |
| 307 { | |
| 308 uint off; | |
| 309 struct inode *ip, *dp; | |
| 310 char name[DIRSIZ]; | |
| 311 | |
| 312 if((dp = nameiparent(path, name)) == 0) { | |
| 313 return 0; | |
| 314 } | |
| 315 | |
| 316 ilock(dp); | |
| 317 | |
| 318 if((ip = dirlookup(dp, name, &off)) != 0){ | |
| 319 iunlockput(dp); | |
| 320 ilock(ip); | |
| 321 | |
| 322 if(type == T_FILE && ip->type == T_FILE) { | |
| 323 return ip; | |
| 324 } | |
| 325 | |
| 326 iunlockput(ip); | |
| 327 | |
| 328 return 0; | |
| 329 } | |
| 330 | |
| 331 if((ip = ialloc(dp->dev, type)) == 0) { | |
| 332 panic("create: ialloc"); | |
| 333 } | |
| 334 | |
| 335 ilock(ip); | |
| 336 ip->major = major; | |
| 337 ip->minor = minor; | |
| 338 ip->nlink = 1; | |
| 339 iupdate(ip); | |
| 340 | |
| 341 if(type == T_DIR){ // Create . and .. entries. | |
| 342 | |
| 343 // No ip->nlink++ for ".": avoid cyclic ref count. | |
| 344 if(dirlink(ip, ".", ip->inum) < 0 || dirlink(ip, "..", dp->inum) < 0) { | |
| 345 panic("create dots"); | |
| 346 } | |
| 347 } | |
| 348 | |
| 349 if(dirlink(dp, name, ip->inum) < 0) { | |
| 350 panic("create: dirlink"); | |
| 351 } | |
| 352 | |
| 353 iunlockput(dp); | |
| 354 | |
| 355 return ip; | |
| 356 } | |
| 357 | |
| 358 int sys_open(void) | |
| 359 { | |
| 360 char *path; | |
| 361 int fd, omode; | |
| 362 struct file *f; | |
| 363 struct inode *ip; | |
| 364 | |
| 365 if(argstr(0, &path) < 0 || argint(1, &omode) < 0) { | |
| 366 return -1; | |
| 367 } | |
| 368 | |
| 369 if(omode & O_CREATE){ | |
| 370 begin_trans(); | |
| 371 ip = create(path, T_FILE, 0, 0); | |
| 372 commit_trans(); | |
| 373 | |
| 374 if(ip == 0) { | |
| 375 return -1; | |
| 376 } | |
| 377 | |
| 378 } else { | |
| 379 if((ip = namei(path)) == 0) { | |
| 380 return -1; | |
| 381 } | |
| 382 | |
| 383 ilock(ip); | |
| 384 | |
| 385 if(ip->type == T_DIR && omode != O_RDONLY){ | |
| 386 iunlockput(ip); | |
| 387 return -1; | |
| 388 } | |
| 389 } | |
| 390 | |
| 391 if((f = filealloc()) == 0 || (fd = fdalloc(f)) < 0){ | |
| 392 if(f) { | |
| 393 fileclose(f); | |
| 394 } | |
| 395 | |
| 396 iunlockput(ip); | |
| 397 return -1; | |
| 398 } | |
| 399 | |
| 400 iunlock(ip); | |
| 401 | |
| 402 f->type = FD_INODE; | |
| 403 f->ip = ip; | |
| 404 f->off = 0; | |
| 405 f->readable = !(omode & O_WRONLY); | |
| 406 f->writable = (omode & O_WRONLY) || (omode & O_RDWR); | |
| 407 | |
| 408 return fd; | |
| 409 } | |
| 410 | |
| 411 int sys_mkdir(void) | |
| 412 { | |
| 413 char *path; | |
| 414 struct inode *ip; | |
| 415 | |
| 416 begin_trans(); | |
| 417 | |
| 418 if(argstr(0, &path) < 0 || (ip = create(path, T_DIR, 0, 0)) == 0){ | |
| 419 commit_trans(); | |
| 420 return -1; | |
| 421 } | |
| 422 | |
| 423 iunlockput(ip); | |
| 424 commit_trans(); | |
| 425 | |
| 426 return 0; | |
| 427 } | |
| 428 | |
| 429 int sys_mknod(void) | |
| 430 { | |
| 431 struct inode *ip; | |
| 432 char *path; | |
| 433 int len; | |
| 434 int major, minor; | |
| 435 | |
| 436 begin_trans(); | |
| 437 | |
| 438 if((len=argstr(0, &path)) < 0 || | |
| 439 argint(1, &major) < 0 || argint(2, &minor) < 0 || | |
| 440 (ip = create(path, T_DEV, major, minor)) == 0){ | |
| 441 | |
| 442 commit_trans(); | |
| 443 return -1; | |
| 444 } | |
| 445 | |
| 446 iunlockput(ip); | |
| 447 commit_trans(); | |
| 448 | |
| 449 return 0; | |
| 450 } | |
| 451 | |
| 452 int sys_chdir(void) | |
| 453 { | |
| 454 char *path; | |
| 455 struct inode *ip; | |
| 456 | |
| 457 if(argstr(0, &path) < 0 || (ip = namei(path)) == 0) { | |
| 458 return -1; | |
| 459 } | |
| 460 | |
| 461 ilock(ip); | |
| 462 | |
| 463 if(ip->type != T_DIR){ | |
| 464 iunlockput(ip); | |
| 465 return -1; | |
| 466 } | |
| 467 | |
| 468 iunlock(ip); | |
| 469 | |
| 470 iput(proc->cwd); | |
| 471 proc->cwd = ip; | |
| 472 | |
| 473 return 0; | |
| 474 } | |
| 475 | |
| 476 int sys_exec(void) | |
| 477 { | |
| 478 char *path, *argv[MAXARG]; | |
| 479 int i; | |
| 480 uint uargv, uarg; | |
| 481 | |
| 482 if(argstr(0, &path) < 0 || argint(1, (int*)&uargv) < 0){ | |
| 483 return -1; | |
| 484 } | |
| 485 | |
| 486 memset(argv, 0, sizeof(argv)); | |
| 487 | |
| 488 for(i=0;; i++){ | |
| 489 if(i >= NELEM(argv)) { | |
| 490 return -1; | |
| 491 } | |
| 492 | |
| 493 if(fetchint(uargv+4*i, (int*)&uarg) < 0) { | |
| 494 return -1; | |
| 495 } | |
| 496 | |
| 497 if(uarg == 0){ | |
| 498 argv[i] = 0; | |
| 499 break; | |
| 500 } | |
| 501 | |
| 502 if(fetchstr(uarg, &argv[i]) < 0) { | |
| 503 return -1; | |
| 504 } | |
| 505 } | |
| 506 | |
| 507 return exec(path, argv); | |
| 508 } | |
| 509 | |
| 510 int sys_pipe(void) | |
| 511 { | |
| 512 int *fd; | |
| 513 struct file *rf, *wf; | |
| 514 int fd0, fd1; | |
| 515 | |
| 516 if(argptr(0, (void*)&fd, 2*sizeof(fd[0])) < 0) { | |
| 517 return -1; | |
| 518 } | |
| 519 | |
| 520 if(pipealloc(&rf, &wf) < 0) { | |
| 521 return -1; | |
| 522 } | |
| 523 | |
| 524 fd0 = -1; | |
| 525 | |
| 526 if((fd0 = fdalloc(rf)) < 0 || (fd1 = fdalloc(wf)) < 0){ | |
| 527 if(fd0 >= 0) { | |
| 528 proc->ofile[fd0] = 0; | |
| 529 } | |
| 530 | |
| 531 fileclose(rf); | |
| 532 fileclose(wf); | |
| 533 | |
| 534 return -1; | |
| 535 } | |
| 536 | |
| 537 fd[0] = fd0; | |
| 538 fd[1] = fd1; | |
| 539 | |
| 540 return 0; | |
| 541 } |