1 /*- 2 * Copyright (c) 1992, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software donated to Berkeley by 6 * Jan-Simon Pendry. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 4. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * @(#)fdesc_vnops.c 8.9 (Berkeley) 1/21/94 33 * 34 * $FreeBSD$ 35 */ 36 37 /* 38 * /dev/fd Filesystem 39 */ 40 41 #include <sys/param.h> 42 #include <sys/systm.h> 43 #include <sys/conf.h> 44 #include <sys/dirent.h> 45 #include <sys/filedesc.h> 46 #include <sys/kernel.h> /* boottime */ 47 #include <sys/lock.h> 48 #include <sys/mutex.h> 49 #include <sys/malloc.h> 50 #include <sys/file.h> /* Must come after sys/malloc.h */ 51 #include <sys/mount.h> 52 #include <sys/namei.h> 53 #include <sys/proc.h> 54 #include <sys/stat.h> 55 #include <sys/vnode.h> 56 57 #include <fs/fdescfs/fdesc.h> 58 59 #define FDL_WANT 0x01 60 #define FDL_LOCKED 0x02 61 static int fdcache_lock; 62 63 #define NFDCACHE 4 64 #define FD_NHASH(ix) \ 65 (&fdhashtbl[(ix) & fdhash]) 66 static LIST_HEAD(fdhashhead, fdescnode) *fdhashtbl; 67 static u_long fdhash; 68 69 static vop_getattr_t fdesc_getattr; 70 static vop_inactive_t fdesc_inactive; 71 static vop_lookup_t fdesc_lookup; 72 static vop_open_t fdesc_open; 73 static vop_readdir_t fdesc_readdir; 74 static vop_reclaim_t fdesc_reclaim; 75 static vop_setattr_t fdesc_setattr; 76 77 static struct vop_vector fdesc_vnodeops = { 78 .vop_default = &default_vnodeops, 79 80 .vop_access = VOP_NULL, 81 .vop_getattr = fdesc_getattr, 82 .vop_inactive = fdesc_inactive, 83 .vop_lookup = fdesc_lookup, 84 .vop_open = fdesc_open, 85 .vop_pathconf = vop_stdpathconf, 86 .vop_readdir = fdesc_readdir, 87 .vop_reclaim = fdesc_reclaim, 88 .vop_setattr = fdesc_setattr, 89 }; 90 91 /* 92 * Initialise cache headers 93 */ 94 int 95 fdesc_init(vfsp) 96 struct vfsconf *vfsp; 97 { 98 99 fdhashtbl = hashinit(NFDCACHE, M_CACHE, &fdhash); 100 return (0); 101 } 102 103 int 104 fdesc_allocvp(ftype, ix, mp, vpp, td) 105 fdntype ftype; 106 int ix; 107 struct mount *mp; 108 struct vnode **vpp; 109 struct thread *td; 110 { 111 struct fdhashhead *fc; 112 struct fdescnode *fd; 113 int error = 0; 114 115 fc = FD_NHASH(ix); 116 loop: 117 LIST_FOREACH(fd, fc, fd_hash) { 118 if (fd->fd_ix == ix && fd->fd_vnode->v_mount == mp) { 119 if (vget(fd->fd_vnode, 0, td)) 120 goto loop; 121 *vpp = fd->fd_vnode; 122 return (error); 123 } 124 } 125 126 /* 127 * otherwise lock the array while we call getnewvnode 128 * since that can block. 129 */ 130 if (fdcache_lock & FDL_LOCKED) { 131 fdcache_lock |= FDL_WANT; 132 (void) tsleep( &fdcache_lock, PINOD, "fdalvp", 0); 133 goto loop; 134 } 135 fdcache_lock |= FDL_LOCKED; 136 137 /* 138 * Do the MALLOC before the getnewvnode since doing so afterward 139 * might cause a bogus v_data pointer to get dereferenced 140 * elsewhere if MALLOC should block. 141 */ 142 MALLOC(fd, struct fdescnode *, sizeof(struct fdescnode), M_TEMP, M_WAITOK); 143 144 error = getnewvnode("fdesc", mp, &fdesc_vnodeops, vpp); 145 if (error) { 146 FREE(fd, M_TEMP); 147 goto out; 148 } 149 (*vpp)->v_data = fd; 150 fd->fd_vnode = *vpp; 151 fd->fd_type = ftype; 152 fd->fd_fd = -1; 153 fd->fd_ix = ix; 154 /* XXX: vnode should be locked here */ 155 error = insmntque(*vpp, mp); /* XXX: Too early for mpsafe fs */ 156 if (error != 0) { 157 free(fd, M_TEMP); 158 *vpp = NULLVP; 159 goto out; 160 } 161 LIST_INSERT_HEAD(fc, fd, fd_hash); 162 163 out: 164 fdcache_lock &= ~FDL_LOCKED; 165 166 if (fdcache_lock & FDL_WANT) { 167 fdcache_lock &= ~FDL_WANT; 168 wakeup( &fdcache_lock); 169 } 170 171 return (error); 172 } 173 174 /* 175 * vp is the current namei directory 176 * ndp is the name to locate in that directory... 177 */ 178 static int 179 fdesc_lookup(ap) 180 struct vop_lookup_args /* { 181 struct vnode * a_dvp; 182 struct vnode ** a_vpp; 183 struct componentname * a_cnp; 184 } */ *ap; 185 { 186 struct vnode **vpp = ap->a_vpp; 187 struct vnode *dvp = ap->a_dvp; 188 struct componentname *cnp = ap->a_cnp; 189 char *pname = cnp->cn_nameptr; 190 struct thread *td = cnp->cn_thread; 191 struct file *fp; 192 int nlen = cnp->cn_namelen; 193 u_int fd; 194 int error; 195 struct vnode *fvp; 196 197 if ((cnp->cn_flags & ISLASTCN) && 198 (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME)) { 199 error = EROFS; 200 goto bad; 201 } 202 203 if (cnp->cn_namelen == 1 && *pname == '.') { 204 *vpp = dvp; 205 VREF(dvp); 206 return (0); 207 } 208 209 if (VTOFDESC(dvp)->fd_type != Froot) { 210 error = ENOTDIR; 211 goto bad; 212 } 213 214 fd = 0; 215 /* the only time a leading 0 is acceptable is if it's "0" */ 216 if (*pname == '0' && nlen != 1) { 217 error = ENOENT; 218 goto bad; 219 } 220 while (nlen--) { 221 if (*pname < '0' || *pname > '9') { 222 error = ENOENT; 223 goto bad; 224 } 225 fd = 10 * fd + *pname++ - '0'; 226 } 227 228 if ((error = fget(td, fd, &fp)) != 0) 229 goto bad; 230 231 error = fdesc_allocvp(Fdesc, FD_DESC+fd, dvp->v_mount, &fvp, td); 232 fdrop(fp, td); 233 if (error) 234 goto bad; 235 VTOFDESC(fvp)->fd_fd = fd; 236 if (fvp != dvp) 237 vn_lock(fvp, LK_EXCLUSIVE | LK_RETRY); 238 *vpp = fvp; 239 return (0); 240 241 bad: 242 *vpp = NULL; 243 return (error); 244 } 245 246 static int 247 fdesc_open(ap) 248 struct vop_open_args /* { 249 struct vnode *a_vp; 250 int a_mode; 251 struct ucred *a_cred; 252 struct thread *a_td; 253 } */ *ap; 254 { 255 struct vnode *vp = ap->a_vp; 256 257 if (VTOFDESC(vp)->fd_type == Froot) 258 return (0); 259 260 /* 261 * XXX Kludge: set td->td_proc->p_dupfd to contain the value of the the file 262 * descriptor being sought for duplication. The error return ensures 263 * that the vnode for this device will be released by vn_open. Open 264 * will detect this special error and take the actions in dupfdopen. 265 * Other callers of vn_open or VOP_OPEN will simply report the 266 * error. 267 */ 268 ap->a_td->td_dupfd = VTOFDESC(vp)->fd_fd; /* XXX */ 269 return (ENODEV); 270 } 271 272 static int 273 fdesc_getattr(ap) 274 struct vop_getattr_args /* { 275 struct vnode *a_vp; 276 struct vattr *a_vap; 277 struct ucred *a_cred; 278 struct thread *a_td; 279 } */ *ap; 280 { 281 struct vnode *vp = ap->a_vp; 282 struct vattr *vap = ap->a_vap; 283 struct file *fp; 284 struct stat stb; 285 u_int fd; 286 int error = 0; 287 288 switch (VTOFDESC(vp)->fd_type) { 289 case Froot: 290 VATTR_NULL(vap); 291 292 vap->va_mode = S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH; 293 vap->va_type = VDIR; 294 vap->va_nlink = 2; 295 vap->va_size = DEV_BSIZE; 296 vap->va_fileid = VTOFDESC(vp)->fd_ix; 297 vap->va_uid = 0; 298 vap->va_gid = 0; 299 vap->va_blocksize = DEV_BSIZE; 300 vap->va_atime.tv_sec = boottime.tv_sec; 301 vap->va_atime.tv_nsec = 0; 302 vap->va_mtime = vap->va_atime; 303 vap->va_ctime = vap->va_mtime; 304 vap->va_gen = 0; 305 vap->va_flags = 0; 306 vap->va_rdev = 0; 307 vap->va_bytes = 0; 308 break; 309 310 case Fdesc: 311 fd = VTOFDESC(vp)->fd_fd; 312 313 if ((error = fget(ap->a_td, fd, &fp)) != 0) 314 return (error); 315 316 bzero(&stb, sizeof(stb)); 317 error = fo_stat(fp, &stb, ap->a_td->td_ucred, ap->a_td); 318 fdrop(fp, ap->a_td); 319 if (error == 0) { 320 VATTR_NULL(vap); 321 vap->va_type = IFTOVT(stb.st_mode); 322 vap->va_mode = stb.st_mode; 323 #define FDRX (VREAD|VEXEC) 324 if (vap->va_type == VDIR) 325 vap->va_mode &= ~((FDRX)|(FDRX>>3)|(FDRX>>6)); 326 #undef FDRX 327 vap->va_nlink = 1; 328 vap->va_flags = 0; 329 vap->va_bytes = stb.st_blocks * stb.st_blksize; 330 vap->va_fileid = VTOFDESC(vp)->fd_ix; 331 vap->va_size = stb.st_size; 332 vap->va_blocksize = stb.st_blksize; 333 vap->va_rdev = stb.st_rdev; 334 335 /* 336 * If no time data is provided, use the current time. 337 */ 338 if (stb.st_atimespec.tv_sec == 0 && 339 stb.st_atimespec.tv_nsec == 0) 340 nanotime(&stb.st_atimespec); 341 342 if (stb.st_ctimespec.tv_sec == 0 && 343 stb.st_ctimespec.tv_nsec == 0) 344 nanotime(&stb.st_ctimespec); 345 346 if (stb.st_mtimespec.tv_sec == 0 && 347 stb.st_mtimespec.tv_nsec == 0) 348 nanotime(&stb.st_mtimespec); 349 350 vap->va_atime = stb.st_atimespec; 351 vap->va_mtime = stb.st_mtimespec; 352 vap->va_ctime = stb.st_ctimespec; 353 vap->va_uid = stb.st_uid; 354 vap->va_gid = stb.st_gid; 355 } 356 break; 357 358 default: 359 panic("fdesc_getattr"); 360 break; 361 } 362 363 if (error == 0) 364 vp->v_type = vap->va_type; 365 return (error); 366 } 367 368 static int 369 fdesc_setattr(ap) 370 struct vop_setattr_args /* { 371 struct vnode *a_vp; 372 struct vattr *a_vap; 373 struct ucred *a_cred; 374 struct thread *a_td; 375 } */ *ap; 376 { 377 struct vattr *vap = ap->a_vap; 378 struct vnode *vp; 379 struct mount *mp; 380 struct file *fp; 381 unsigned fd; 382 int error; 383 384 /* 385 * Can't mess with the root vnode 386 */ 387 if (VTOFDESC(ap->a_vp)->fd_type == Froot) 388 return (EACCES); 389 390 fd = VTOFDESC(ap->a_vp)->fd_fd; 391 392 /* 393 * Allow setattr where there is an underlying vnode. 394 */ 395 error = getvnode(ap->a_td->td_proc->p_fd, fd, &fp); 396 if (error) { 397 /* 398 * getvnode() returns EINVAL if the file descriptor is not 399 * backed by a vnode. Silently drop all changes except 400 * chflags(2) in this case. 401 */ 402 if (error == EINVAL) { 403 if (vap->va_flags != VNOVAL) 404 error = EOPNOTSUPP; 405 else 406 error = 0; 407 } 408 return (error); 409 } 410 vp = fp->f_vnode; 411 if ((error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) == 0) { 412 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 413 error = VOP_SETATTR(vp, ap->a_vap, ap->a_cred, ap->a_td); 414 VOP_UNLOCK(vp, 0); 415 vn_finished_write(mp); 416 } 417 fdrop(fp, ap->a_td); 418 return (error); 419 } 420 421 #define UIO_MX 16 422 423 static int 424 fdesc_readdir(ap) 425 struct vop_readdir_args /* { 426 struct vnode *a_vp; 427 struct uio *a_uio; 428 struct ucred *a_cred; 429 int *a_eofflag; 430 u_long *a_cookies; 431 int a_ncookies; 432 } */ *ap; 433 { 434 struct uio *uio = ap->a_uio; 435 struct filedesc *fdp; 436 struct dirent d; 437 struct dirent *dp = &d; 438 int error, i, off, fcnt; 439 440 /* 441 * We don't allow exporting fdesc mounts, and currently local 442 * requests do not need cookies. 443 */ 444 if (ap->a_ncookies) 445 panic("fdesc_readdir: not hungry"); 446 447 if (VTOFDESC(ap->a_vp)->fd_type != Froot) 448 panic("fdesc_readdir: not dir"); 449 450 off = (int)uio->uio_offset; 451 if (off != uio->uio_offset || off < 0 || (u_int)off % UIO_MX != 0 || 452 uio->uio_resid < UIO_MX) 453 return (EINVAL); 454 i = (u_int)off / UIO_MX; 455 fdp = uio->uio_td->td_proc->p_fd; 456 error = 0; 457 458 fcnt = i - 2; /* The first two nodes are `.' and `..' */ 459 460 FILEDESC_SLOCK(fdp); 461 while (i < fdp->fd_nfiles + 2 && uio->uio_resid >= UIO_MX) { 462 switch (i) { 463 case 0: /* `.' */ 464 case 1: /* `..' */ 465 bzero((caddr_t)dp, UIO_MX); 466 467 dp->d_fileno = i + FD_ROOT; 468 dp->d_namlen = i + 1; 469 dp->d_reclen = UIO_MX; 470 bcopy("..", dp->d_name, dp->d_namlen); 471 dp->d_name[i + 1] = '\0'; 472 dp->d_type = DT_DIR; 473 break; 474 default: 475 if (fdp->fd_ofiles[fcnt] == NULL) { 476 FILEDESC_SUNLOCK(fdp); 477 goto done; 478 } 479 480 bzero((caddr_t) dp, UIO_MX); 481 dp->d_namlen = sprintf(dp->d_name, "%d", fcnt); 482 dp->d_reclen = UIO_MX; 483 dp->d_type = DT_UNKNOWN; 484 dp->d_fileno = i + FD_DESC; 485 break; 486 } 487 /* 488 * And ship to userland 489 */ 490 FILEDESC_SUNLOCK(fdp); 491 error = uiomove(dp, UIO_MX, uio); 492 if (error) 493 goto done; 494 FILEDESC_SLOCK(fdp); 495 i++; 496 fcnt++; 497 } 498 FILEDESC_SUNLOCK(fdp); 499 500 done: 501 uio->uio_offset = i * UIO_MX; 502 return (error); 503 } 504 505 static int 506 fdesc_inactive(ap) 507 struct vop_inactive_args /* { 508 struct vnode *a_vp; 509 struct thread *a_td; 510 } */ *ap; 511 { 512 struct vnode *vp = ap->a_vp; 513 514 /* 515 * Clear out the v_type field to avoid 516 * nasty things happening in vgone(). 517 */ 518 vp->v_type = VNON; 519 return (0); 520 } 521 522 static int 523 fdesc_reclaim(ap) 524 struct vop_reclaim_args /* { 525 struct vnode *a_vp; 526 } */ *ap; 527 { 528 struct vnode *vp = ap->a_vp; 529 struct fdescnode *fd = VTOFDESC(vp); 530 531 LIST_REMOVE(fd, fd_hash); 532 FREE(vp->v_data, M_TEMP); 533 vp->v_data = 0; 534 535 return (0); 536 } 537