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, LK_EXCLUSIVE | LK_CANRECURSE, 120 td)) 121 goto loop; 122 *vpp = fd->fd_vnode; 123 VOP_UNLOCK(*vpp, 0); 124 return (error); 125 } 126 } 127 128 /* 129 * otherwise lock the array while we call getnewvnode 130 * since that can block. 131 */ 132 if (fdcache_lock & FDL_LOCKED) { 133 fdcache_lock |= FDL_WANT; 134 (void) tsleep( &fdcache_lock, PINOD, "fdalvp", 0); 135 goto loop; 136 } 137 fdcache_lock |= FDL_LOCKED; 138 139 /* 140 * Do the MALLOC before the getnewvnode since doing so afterward 141 * might cause a bogus v_data pointer to get dereferenced 142 * elsewhere if MALLOC should block. 143 */ 144 MALLOC(fd, struct fdescnode *, sizeof(struct fdescnode), M_TEMP, M_WAITOK); 145 146 error = getnewvnode("fdescfs", mp, &fdesc_vnodeops, vpp); 147 if (error) { 148 FREE(fd, M_TEMP); 149 goto out; 150 } 151 (*vpp)->v_data = fd; 152 fd->fd_vnode = *vpp; 153 fd->fd_type = ftype; 154 fd->fd_fd = -1; 155 fd->fd_ix = ix; 156 /* XXX: vnode should be locked here */ 157 error = insmntque(*vpp, mp); /* XXX: Too early for mpsafe fs */ 158 if (error != 0) { 159 free(fd, M_TEMP); 160 *vpp = NULLVP; 161 goto out; 162 } 163 LIST_INSERT_HEAD(fc, fd, fd_hash); 164 165 out: 166 fdcache_lock &= ~FDL_LOCKED; 167 168 if (fdcache_lock & FDL_WANT) { 169 fdcache_lock &= ~FDL_WANT; 170 wakeup( &fdcache_lock); 171 } 172 173 return (error); 174 } 175 176 /* 177 * vp is the current namei directory 178 * ndp is the name to locate in that directory... 179 */ 180 static int 181 fdesc_lookup(ap) 182 struct vop_lookup_args /* { 183 struct vnode * a_dvp; 184 struct vnode ** a_vpp; 185 struct componentname * a_cnp; 186 } */ *ap; 187 { 188 struct vnode **vpp = ap->a_vpp; 189 struct vnode *dvp = ap->a_dvp; 190 struct componentname *cnp = ap->a_cnp; 191 char *pname = cnp->cn_nameptr; 192 struct thread *td = cnp->cn_thread; 193 struct file *fp; 194 int nlen = cnp->cn_namelen; 195 u_int fd; 196 int error; 197 struct vnode *fvp; 198 199 if ((cnp->cn_flags & ISLASTCN) && 200 (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME)) { 201 error = EROFS; 202 goto bad; 203 } 204 205 if (cnp->cn_namelen == 1 && *pname == '.') { 206 *vpp = dvp; 207 VREF(dvp); 208 return (0); 209 } 210 211 if (VTOFDESC(dvp)->fd_type != Froot) { 212 error = ENOTDIR; 213 goto bad; 214 } 215 216 fd = 0; 217 /* the only time a leading 0 is acceptable is if it's "0" */ 218 if (*pname == '0' && nlen != 1) { 219 error = ENOENT; 220 goto bad; 221 } 222 while (nlen--) { 223 if (*pname < '0' || *pname > '9') { 224 error = ENOENT; 225 goto bad; 226 } 227 fd = 10 * fd + *pname++ - '0'; 228 } 229 230 if ((error = fget(td, fd, &fp)) != 0) 231 goto bad; 232 233 error = fdesc_allocvp(Fdesc, FD_DESC+fd, dvp->v_mount, &fvp, td); 234 fdrop(fp, td); 235 if (error) 236 goto bad; 237 VTOFDESC(fvp)->fd_fd = fd; 238 if (fvp != dvp) 239 vn_lock(fvp, LK_EXCLUSIVE | LK_RETRY); 240 *vpp = fvp; 241 return (0); 242 243 bad: 244 *vpp = NULL; 245 return (error); 246 } 247 248 static int 249 fdesc_open(ap) 250 struct vop_open_args /* { 251 struct vnode *a_vp; 252 int a_mode; 253 struct ucred *a_cred; 254 struct thread *a_td; 255 } */ *ap; 256 { 257 struct vnode *vp = ap->a_vp; 258 259 if (VTOFDESC(vp)->fd_type == Froot) 260 return (0); 261 262 /* 263 * XXX Kludge: set td->td_proc->p_dupfd to contain the value of the the file 264 * descriptor being sought for duplication. The error return ensures 265 * that the vnode for this device will be released by vn_open. Open 266 * will detect this special error and take the actions in dupfdopen. 267 * Other callers of vn_open or VOP_OPEN will simply report the 268 * error. 269 */ 270 ap->a_td->td_dupfd = VTOFDESC(vp)->fd_fd; /* XXX */ 271 return (ENODEV); 272 } 273 274 static int 275 fdesc_getattr(ap) 276 struct vop_getattr_args /* { 277 struct vnode *a_vp; 278 struct vattr *a_vap; 279 struct ucred *a_cred; 280 struct thread *a_td; 281 } */ *ap; 282 { 283 struct vnode *vp = ap->a_vp; 284 struct vattr *vap = ap->a_vap; 285 struct file *fp; 286 struct stat stb; 287 u_int fd; 288 int error = 0; 289 290 switch (VTOFDESC(vp)->fd_type) { 291 case Froot: 292 VATTR_NULL(vap); 293 294 vap->va_mode = S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH; 295 vap->va_type = VDIR; 296 vap->va_nlink = 2; 297 vap->va_size = DEV_BSIZE; 298 vap->va_fileid = VTOFDESC(vp)->fd_ix; 299 vap->va_uid = 0; 300 vap->va_gid = 0; 301 vap->va_blocksize = DEV_BSIZE; 302 vap->va_atime.tv_sec = boottime.tv_sec; 303 vap->va_atime.tv_nsec = 0; 304 vap->va_mtime = vap->va_atime; 305 vap->va_ctime = vap->va_mtime; 306 vap->va_gen = 0; 307 vap->va_flags = 0; 308 vap->va_rdev = 0; 309 vap->va_bytes = 0; 310 break; 311 312 case Fdesc: 313 fd = VTOFDESC(vp)->fd_fd; 314 315 if ((error = fget(ap->a_td, fd, &fp)) != 0) 316 return (error); 317 318 bzero(&stb, sizeof(stb)); 319 error = fo_stat(fp, &stb, ap->a_td->td_ucred, ap->a_td); 320 fdrop(fp, ap->a_td); 321 if (error == 0) { 322 VATTR_NULL(vap); 323 vap->va_type = IFTOVT(stb.st_mode); 324 vap->va_mode = stb.st_mode; 325 #define FDRX (VREAD|VEXEC) 326 if (vap->va_type == VDIR) 327 vap->va_mode &= ~((FDRX)|(FDRX>>3)|(FDRX>>6)); 328 #undef FDRX 329 vap->va_nlink = 1; 330 vap->va_flags = 0; 331 vap->va_bytes = stb.st_blocks * stb.st_blksize; 332 vap->va_fileid = VTOFDESC(vp)->fd_ix; 333 vap->va_size = stb.st_size; 334 vap->va_blocksize = stb.st_blksize; 335 vap->va_rdev = stb.st_rdev; 336 337 /* 338 * If no time data is provided, use the current time. 339 */ 340 if (stb.st_atimespec.tv_sec == 0 && 341 stb.st_atimespec.tv_nsec == 0) 342 nanotime(&stb.st_atimespec); 343 344 if (stb.st_ctimespec.tv_sec == 0 && 345 stb.st_ctimespec.tv_nsec == 0) 346 nanotime(&stb.st_ctimespec); 347 348 if (stb.st_mtimespec.tv_sec == 0 && 349 stb.st_mtimespec.tv_nsec == 0) 350 nanotime(&stb.st_mtimespec); 351 352 vap->va_atime = stb.st_atimespec; 353 vap->va_mtime = stb.st_mtimespec; 354 vap->va_ctime = stb.st_ctimespec; 355 vap->va_uid = stb.st_uid; 356 vap->va_gid = stb.st_gid; 357 } 358 break; 359 360 default: 361 panic("fdesc_getattr"); 362 break; 363 } 364 365 if (error == 0) 366 vp->v_type = vap->va_type; 367 return (error); 368 } 369 370 static int 371 fdesc_setattr(ap) 372 struct vop_setattr_args /* { 373 struct vnode *a_vp; 374 struct vattr *a_vap; 375 struct ucred *a_cred; 376 struct thread *a_td; 377 } */ *ap; 378 { 379 struct vattr *vap = ap->a_vap; 380 struct vnode *vp; 381 struct mount *mp; 382 struct file *fp; 383 unsigned fd; 384 int error; 385 386 /* 387 * Can't mess with the root vnode 388 */ 389 if (VTOFDESC(ap->a_vp)->fd_type == Froot) 390 return (EACCES); 391 392 fd = VTOFDESC(ap->a_vp)->fd_fd; 393 394 /* 395 * Allow setattr where there is an underlying vnode. 396 */ 397 error = getvnode(ap->a_td->td_proc->p_fd, fd, &fp); 398 if (error) { 399 /* 400 * getvnode() returns EINVAL if the file descriptor is not 401 * backed by a vnode. Silently drop all changes except 402 * chflags(2) in this case. 403 */ 404 if (error == EINVAL) { 405 if (vap->va_flags != VNOVAL) 406 error = EOPNOTSUPP; 407 else 408 error = 0; 409 } 410 return (error); 411 } 412 vp = fp->f_vnode; 413 if ((error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) == 0) { 414 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 415 error = VOP_SETATTR(vp, ap->a_vap, ap->a_cred, ap->a_td); 416 VOP_UNLOCK(vp, 0); 417 vn_finished_write(mp); 418 } 419 fdrop(fp, ap->a_td); 420 return (error); 421 } 422 423 #define UIO_MX 16 424 425 static int 426 fdesc_readdir(ap) 427 struct vop_readdir_args /* { 428 struct vnode *a_vp; 429 struct uio *a_uio; 430 struct ucred *a_cred; 431 int *a_eofflag; 432 u_long *a_cookies; 433 int a_ncookies; 434 } */ *ap; 435 { 436 struct uio *uio = ap->a_uio; 437 struct filedesc *fdp; 438 struct dirent d; 439 struct dirent *dp = &d; 440 int error, i, off, fcnt; 441 442 /* 443 * We don't allow exporting fdesc mounts, and currently local 444 * requests do not need cookies. 445 */ 446 if (ap->a_ncookies) 447 panic("fdesc_readdir: not hungry"); 448 449 if (VTOFDESC(ap->a_vp)->fd_type != Froot) 450 panic("fdesc_readdir: not dir"); 451 452 off = (int)uio->uio_offset; 453 if (off != uio->uio_offset || off < 0 || (u_int)off % UIO_MX != 0 || 454 uio->uio_resid < UIO_MX) 455 return (EINVAL); 456 i = (u_int)off / UIO_MX; 457 fdp = uio->uio_td->td_proc->p_fd; 458 error = 0; 459 460 fcnt = i - 2; /* The first two nodes are `.' and `..' */ 461 462 FILEDESC_SLOCK(fdp); 463 while (i < fdp->fd_nfiles + 2 && uio->uio_resid >= UIO_MX) { 464 switch (i) { 465 case 0: /* `.' */ 466 case 1: /* `..' */ 467 bzero((caddr_t)dp, UIO_MX); 468 469 dp->d_fileno = i + FD_ROOT; 470 dp->d_namlen = i + 1; 471 dp->d_reclen = UIO_MX; 472 bcopy("..", dp->d_name, dp->d_namlen); 473 dp->d_name[i + 1] = '\0'; 474 dp->d_type = DT_DIR; 475 break; 476 default: 477 if (fdp->fd_ofiles[fcnt] == NULL) { 478 FILEDESC_SUNLOCK(fdp); 479 goto done; 480 } 481 482 bzero((caddr_t) dp, UIO_MX); 483 dp->d_namlen = sprintf(dp->d_name, "%d", fcnt); 484 dp->d_reclen = UIO_MX; 485 dp->d_type = DT_UNKNOWN; 486 dp->d_fileno = i + FD_DESC; 487 break; 488 } 489 /* 490 * And ship to userland 491 */ 492 FILEDESC_SUNLOCK(fdp); 493 error = uiomove(dp, UIO_MX, uio); 494 if (error) 495 goto done; 496 FILEDESC_SLOCK(fdp); 497 i++; 498 fcnt++; 499 } 500 FILEDESC_SUNLOCK(fdp); 501 502 done: 503 uio->uio_offset = i * UIO_MX; 504 return (error); 505 } 506 507 static int 508 fdesc_inactive(ap) 509 struct vop_inactive_args /* { 510 struct vnode *a_vp; 511 struct thread *a_td; 512 } */ *ap; 513 { 514 struct vnode *vp = ap->a_vp; 515 516 /* 517 * Clear out the v_type field to avoid 518 * nasty things happening in vgone(). 519 */ 520 vp->v_type = VNON; 521 return (0); 522 } 523 524 static int 525 fdesc_reclaim(ap) 526 struct vop_reclaim_args /* { 527 struct vnode *a_vp; 528 } */ *ap; 529 { 530 struct vnode *vp = ap->a_vp; 531 struct fdescnode *fd = VTOFDESC(vp); 532 533 LIST_REMOVE(fd, fd_hash); 534 FREE(vp->v_data, M_TEMP); 535 vp->v_data = 0; 536 537 return (0); 538 } 539