Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/fs/msdosfs/msdosfs_denode.c
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1 /* $FreeBSD$ */ 2 /* $NetBSD: msdosfs_denode.c,v 1.28 1998/02/10 14:10:00 mrg Exp $ */ 3 4 /*- 5 * Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank. 6 * Copyright (C) 1994, 1995, 1997 TooLs GmbH. 7 * All rights reserved. 8 * Original code by Paul Popelka (paulp@uts.amdahl.com) (see below). 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by TooLs GmbH. 21 * 4. The name of TooLs GmbH may not be used to endorse or promote products 22 * derived from this software without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR 25 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 26 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 27 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 28 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 29 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 30 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 31 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 32 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 33 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 34 */ 35 /*- 36 * Written by Paul Popelka (paulp@uts.amdahl.com) 37 * 38 * You can do anything you want with this software, just don't say you wrote 39 * it, and don't remove this notice. 40 * 41 * This software is provided "as is". 42 * 43 * The author supplies this software to be publicly redistributed on the 44 * understanding that the author is not responsible for the correct 45 * functioning of this software in any circumstances and is not liable for 46 * any damages caused by this software. 47 * 48 * October 1992 49 */ 50 51 #include <sys/param.h> 52 #include <sys/systm.h> 53 #include <sys/buf.h> 54 #include <sys/clock.h> 55 #include <sys/kernel.h> 56 #include <sys/malloc.h> 57 #include <sys/mount.h> 58 #include <sys/vnode.h> 59 60 #include <vm/vm.h> 61 #include <vm/vm_extern.h> 62 63 #include <fs/msdosfs/bpb.h> 64 #include <fs/msdosfs/direntry.h> 65 #include <fs/msdosfs/denode.h> 66 #include <fs/msdosfs/fat.h> 67 #include <fs/msdosfs/msdosfsmount.h> 68 69 static MALLOC_DEFINE(M_MSDOSFSNODE, "msdosfs_node", "MSDOSFS vnode private part"); 70 71 static int 72 de_vncmpf(struct vnode *vp, void *arg) 73 { 74 struct denode *de; 75 uint64_t *a; 76 77 a = arg; 78 de = VTODE(vp); 79 return (de->de_inode != *a); 80 } 81 82 /* 83 * If deget() succeeds it returns with the gotten denode locked(). 84 * 85 * pmp - address of msdosfsmount structure of the filesystem containing 86 * the denode of interest. The address of 87 * the msdosfsmount structure are used. 88 * dirclust - which cluster bp contains, if dirclust is 0 (root directory) 89 * diroffset is relative to the beginning of the root directory, 90 * otherwise it is cluster relative. 91 * diroffset - offset past begin of cluster of denode we want 92 * depp - returns the address of the gotten denode. 93 */ 94 int 95 deget(pmp, dirclust, diroffset, depp) 96 struct msdosfsmount *pmp; /* so we know the maj/min number */ 97 u_long dirclust; /* cluster this dir entry came from */ 98 u_long diroffset; /* index of entry within the cluster */ 99 struct denode **depp; /* returns the addr of the gotten denode */ 100 { 101 int error; 102 uint64_t inode; 103 struct mount *mntp = pmp->pm_mountp; 104 struct direntry *direntptr; 105 struct denode *ldep; 106 struct vnode *nvp, *xvp; 107 struct buf *bp; 108 struct thread *td; 109 110 #ifdef MSDOSFS_DEBUG 111 printf("deget(pmp %p, dirclust %lu, diroffset %lx, depp %p)\n", 112 pmp, dirclust, diroffset, depp); 113 #endif 114 115 /* 116 * On FAT32 filesystems, root is a (more or less) normal 117 * directory 118 */ 119 if (FAT32(pmp) && dirclust == MSDOSFSROOT) 120 dirclust = pmp->pm_rootdirblk; 121 122 /* 123 * See if the denode is in the denode cache. Use the location of 124 * the directory entry to compute the hash value. For subdir use 125 * address of "." entry. For root dir (if not FAT32) use cluster 126 * MSDOSFSROOT, offset MSDOSFSROOT_OFS 127 * 128 * NOTE: The check for de_refcnt > 0 below insures the denode being 129 * examined does not represent an unlinked but still open file. 130 * These files are not to be accessible even when the directory 131 * entry that represented the file happens to be reused while the 132 * deleted file is still open. 133 */ 134 inode = (uint64_t)pmp->pm_bpcluster * dirclust + diroffset; 135 136 error = vfs_hash_get(mntp, inode, LK_EXCLUSIVE, curthread, &nvp, 137 de_vncmpf, &inode); 138 if (error) 139 return (error); 140 if (nvp != NULL) { 141 *depp = VTODE(nvp); 142 KASSERT((*depp)->de_dirclust == dirclust, ("wrong dirclust")); 143 KASSERT((*depp)->de_diroffset == diroffset, ("wrong diroffset")); 144 return (0); 145 } 146 147 /* 148 * Do the MALLOC before the getnewvnode since doing so afterward 149 * might cause a bogus v_data pointer to get dereferenced 150 * elsewhere if MALLOC should block. 151 */ 152 MALLOC(ldep, struct denode *, sizeof(struct denode), M_MSDOSFSNODE, M_WAITOK); 153 154 /* 155 * Directory entry was not in cache, have to create a vnode and 156 * copy it from the passed disk buffer. 157 */ 158 /* getnewvnode() does a VREF() on the vnode */ 159 error = getnewvnode("msdosfs", mntp, &msdosfs_vnodeops, &nvp); 160 if (error) { 161 *depp = NULL; 162 FREE(ldep, M_MSDOSFSNODE); 163 return error; 164 } 165 bzero((caddr_t)ldep, sizeof *ldep); 166 nvp->v_data = ldep; 167 ldep->de_vnode = nvp; 168 ldep->de_flag = 0; 169 ldep->de_dirclust = dirclust; 170 ldep->de_diroffset = diroffset; 171 ldep->de_inode = inode; 172 fc_purge(ldep, 0); /* init the fat cache for this denode */ 173 174 td = curthread; 175 lockmgr(nvp->v_vnlock, LK_EXCLUSIVE, NULL, td); 176 error = insmntque(nvp, mntp); 177 if (error != 0) { 178 FREE(ldep, M_MSDOSFSNODE); 179 *depp = NULL; 180 return (error); 181 } 182 error = vfs_hash_insert(nvp, inode, LK_EXCLUSIVE, td, &xvp, 183 de_vncmpf, &inode); 184 if (error) { 185 *depp = NULL; 186 return (error); 187 } 188 if (xvp != NULL) { 189 /* XXX: Not sure this is right */ 190 nvp = xvp; 191 ldep->de_vnode = nvp; 192 } 193 194 ldep->de_pmp = pmp; 195 ldep->de_refcnt = 1; 196 /* 197 * Copy the directory entry into the denode area of the vnode. 198 */ 199 if ((dirclust == MSDOSFSROOT 200 || (FAT32(pmp) && dirclust == pmp->pm_rootdirblk)) 201 && diroffset == MSDOSFSROOT_OFS) { 202 /* 203 * Directory entry for the root directory. There isn't one, 204 * so we manufacture one. We should probably rummage 205 * through the root directory and find a label entry (if it 206 * exists), and then use the time and date from that entry 207 * as the time and date for the root denode. 208 */ 209 nvp->v_vflag |= VV_ROOT; /* should be further down XXX */ 210 211 ldep->de_Attributes = ATTR_DIRECTORY; 212 ldep->de_LowerCase = 0; 213 if (FAT32(pmp)) 214 ldep->de_StartCluster = pmp->pm_rootdirblk; 215 /* de_FileSize will be filled in further down */ 216 else { 217 ldep->de_StartCluster = MSDOSFSROOT; 218 ldep->de_FileSize = pmp->pm_rootdirsize * DEV_BSIZE; 219 } 220 /* 221 * fill in time and date so that fattime2timespec() doesn't 222 * spit up when called from msdosfs_getattr() with root 223 * denode 224 */ 225 ldep->de_CHun = 0; 226 ldep->de_CTime = 0x0000; /* 00:00:00 */ 227 ldep->de_CDate = (0 << DD_YEAR_SHIFT) | (1 << DD_MONTH_SHIFT) 228 | (1 << DD_DAY_SHIFT); 229 /* Jan 1, 1980 */ 230 ldep->de_ADate = ldep->de_CDate; 231 ldep->de_MTime = ldep->de_CTime; 232 ldep->de_MDate = ldep->de_CDate; 233 /* leave the other fields as garbage */ 234 } else { 235 error = readep(pmp, dirclust, diroffset, &bp, &direntptr); 236 if (error) { 237 /* 238 * The denode does not contain anything useful, so 239 * it would be wrong to leave it on its hash chain. 240 * Arrange for vput() to just forget about it. 241 */ 242 ldep->de_Name[0] = SLOT_DELETED; 243 244 vput(nvp); 245 *depp = NULL; 246 return (error); 247 } 248 DE_INTERNALIZE(ldep, direntptr); 249 brelse(bp); 250 } 251 252 /* 253 * Fill in a few fields of the vnode and finish filling in the 254 * denode. Then return the address of the found denode. 255 */ 256 if (ldep->de_Attributes & ATTR_DIRECTORY) { 257 /* 258 * Since DOS directory entries that describe directories 259 * have 0 in the filesize field, we take this opportunity 260 * to find out the length of the directory and plug it into 261 * the denode structure. 262 */ 263 u_long size; 264 265 /* 266 * XXX it sometimes happens that the "." entry has cluster 267 * number 0 when it shouldn't. Use the actual cluster number 268 * instead of what is written in directory entry. 269 */ 270 if (diroffset == 0 && ldep->de_StartCluster != dirclust) { 271 printf("deget(): \".\" entry at clust %lu != %lu\n", 272 dirclust, ldep->de_StartCluster); 273 ldep->de_StartCluster = dirclust; 274 } 275 276 nvp->v_type = VDIR; 277 if (ldep->de_StartCluster != MSDOSFSROOT) { 278 error = pcbmap(ldep, 0xffff, 0, &size, 0); 279 if (error == E2BIG) { 280 ldep->de_FileSize = de_cn2off(pmp, size); 281 error = 0; 282 } else 283 printf("deget(): pcbmap returned %d\n", error); 284 } 285 } else 286 nvp->v_type = VREG; 287 ldep->de_modrev = init_va_filerev(); 288 *depp = ldep; 289 return (0); 290 } 291 292 int 293 deupdat(dep, waitfor) 294 struct denode *dep; 295 int waitfor; 296 { 297 int error; 298 struct buf *bp; 299 struct direntry *dirp; 300 struct timespec ts; 301 302 if (DETOV(dep)->v_mount->mnt_flag & MNT_RDONLY) 303 return (0); 304 getnanotime(&ts); 305 DETIMES(dep, &ts, &ts, &ts); 306 if ((dep->de_flag & DE_MODIFIED) == 0) 307 return (0); 308 dep->de_flag &= ~DE_MODIFIED; 309 if (dep->de_Attributes & ATTR_DIRECTORY) 310 return (0); 311 if (dep->de_refcnt <= 0) 312 return (0); 313 error = readde(dep, &bp, &dirp); 314 if (error) 315 return (error); 316 DE_EXTERNALIZE(dirp, dep); 317 if (waitfor) 318 return (bwrite(bp)); 319 else { 320 bdwrite(bp); 321 return (0); 322 } 323 } 324 325 /* 326 * Truncate the file described by dep to the length specified by length. 327 */ 328 int 329 detrunc(dep, length, flags, cred, td) 330 struct denode *dep; 331 u_long length; 332 int flags; 333 struct ucred *cred; 334 struct thread *td; 335 { 336 int error; 337 int allerror; 338 u_long eofentry; 339 u_long chaintofree; 340 daddr_t bn; 341 int boff; 342 int isadir = dep->de_Attributes & ATTR_DIRECTORY; 343 struct buf *bp; 344 struct msdosfsmount *pmp = dep->de_pmp; 345 346 #ifdef MSDOSFS_DEBUG 347 printf("detrunc(): file %s, length %lu, flags %x\n", dep->de_Name, length, flags); 348 #endif 349 350 /* 351 * Disallow attempts to truncate the root directory since it is of 352 * fixed size. That's just the way dos filesystems are. We use 353 * the VROOT bit in the vnode because checking for the directory 354 * bit and a startcluster of 0 in the denode is not adequate to 355 * recognize the root directory at this point in a file or 356 * directory's life. 357 */ 358 if ((DETOV(dep)->v_vflag & VV_ROOT) && !FAT32(pmp)) { 359 printf("detrunc(): can't truncate root directory, clust %ld, offset %ld\n", 360 dep->de_dirclust, dep->de_diroffset); 361 return (EINVAL); 362 } 363 364 if (dep->de_FileSize < length) { 365 vnode_pager_setsize(DETOV(dep), length); 366 return deextend(dep, length, cred); 367 } 368 369 /* 370 * If the desired length is 0 then remember the starting cluster of 371 * the file and set the StartCluster field in the directory entry 372 * to 0. If the desired length is not zero, then get the number of 373 * the last cluster in the shortened file. Then get the number of 374 * the first cluster in the part of the file that is to be freed. 375 * Then set the next cluster pointer in the last cluster of the 376 * file to CLUST_EOFE. 377 */ 378 if (length == 0) { 379 chaintofree = dep->de_StartCluster; 380 dep->de_StartCluster = 0; 381 eofentry = ~0; 382 } else { 383 error = pcbmap(dep, de_clcount(pmp, length) - 1, 0, 384 &eofentry, 0); 385 if (error) { 386 #ifdef MSDOSFS_DEBUG 387 printf("detrunc(): pcbmap fails %d\n", error); 388 #endif 389 return (error); 390 } 391 } 392 393 fc_purge(dep, de_clcount(pmp, length)); 394 395 /* 396 * If the new length is not a multiple of the cluster size then we 397 * must zero the tail end of the new last cluster in case it 398 * becomes part of the file again because of a seek. 399 */ 400 if ((boff = length & pmp->pm_crbomask) != 0) { 401 if (isadir) { 402 bn = cntobn(pmp, eofentry); 403 error = bread(pmp->pm_devvp, bn, pmp->pm_bpcluster, 404 NOCRED, &bp); 405 if (error) { 406 brelse(bp); 407 #ifdef MSDOSFS_DEBUG 408 printf("detrunc(): bread fails %d\n", error); 409 #endif 410 return (error); 411 } 412 bzero(bp->b_data + boff, pmp->pm_bpcluster - boff); 413 if (flags & IO_SYNC) 414 bwrite(bp); 415 else 416 bdwrite(bp); 417 } 418 } 419 420 /* 421 * Write out the updated directory entry. Even if the update fails 422 * we free the trailing clusters. 423 */ 424 dep->de_FileSize = length; 425 if (!isadir) 426 dep->de_flag |= DE_UPDATE | DE_MODIFIED; 427 allerror = vtruncbuf(DETOV(dep), cred, td, length, pmp->pm_bpcluster); 428 #ifdef MSDOSFS_DEBUG 429 if (allerror) 430 printf("detrunc(): vtruncbuf error %d\n", allerror); 431 #endif 432 error = deupdat(dep, 1); 433 if (error != 0 && allerror == 0) 434 allerror = error; 435 #ifdef MSDOSFS_DEBUG 436 printf("detrunc(): allerror %d, eofentry %lu\n", 437 allerror, eofentry); 438 #endif 439 440 /* 441 * If we need to break the cluster chain for the file then do it 442 * now. 443 */ 444 if (eofentry != ~0) { 445 error = fatentry(FAT_GET_AND_SET, pmp, eofentry, 446 &chaintofree, CLUST_EOFE); 447 if (error) { 448 #ifdef MSDOSFS_DEBUG 449 printf("detrunc(): fatentry errors %d\n", error); 450 #endif 451 return (error); 452 } 453 fc_setcache(dep, FC_LASTFC, de_cluster(pmp, length - 1), 454 eofentry); 455 } 456 457 /* 458 * Now free the clusters removed from the file because of the 459 * truncation. 460 */ 461 if (chaintofree != 0 && !MSDOSFSEOF(pmp, chaintofree)) 462 freeclusterchain(pmp, chaintofree); 463 464 return (allerror); 465 } 466 467 /* 468 * Extend the file described by dep to length specified by length. 469 */ 470 int 471 deextend(dep, length, cred) 472 struct denode *dep; 473 u_long length; 474 struct ucred *cred; 475 { 476 struct msdosfsmount *pmp = dep->de_pmp; 477 u_long count; 478 int error; 479 480 /* 481 * The root of a DOS filesystem cannot be extended. 482 */ 483 if ((DETOV(dep)->v_vflag & VV_ROOT) && !FAT32(pmp)) 484 return (EINVAL); 485 486 /* 487 * Directories cannot be extended. 488 */ 489 if (dep->de_Attributes & ATTR_DIRECTORY) 490 return (EISDIR); 491 492 if (length <= dep->de_FileSize) 493 panic("deextend: file too large"); 494 495 /* 496 * Compute the number of clusters to allocate. 497 */ 498 count = de_clcount(pmp, length) - de_clcount(pmp, dep->de_FileSize); 499 if (count > 0) { 500 if (count > pmp->pm_freeclustercount) 501 return (ENOSPC); 502 error = extendfile(dep, count, NULL, NULL, DE_CLEAR); 503 if (error) { 504 /* truncate the added clusters away again */ 505 (void) detrunc(dep, dep->de_FileSize, 0, cred, NULL); 506 return (error); 507 } 508 } 509 dep->de_FileSize = length; 510 dep->de_flag |= DE_UPDATE | DE_MODIFIED; 511 return (deupdat(dep, 1)); 512 } 513 514 /* 515 * Move a denode to its correct hash queue after the file it represents has 516 * been moved to a new directory. 517 */ 518 void 519 reinsert(dep) 520 struct denode *dep; 521 { 522 struct vnode *vp; 523 524 /* 525 * Fix up the denode cache. If the denode is for a directory, 526 * there is nothing to do since the hash is based on the starting 527 * cluster of the directory file and that hasn't changed. If for a 528 * file the hash is based on the location of the directory entry, 529 * so we must remove it from the cache and re-enter it with the 530 * hash based on the new location of the directory entry. 531 */ 532 #if 0 533 if (dep->de_Attributes & ATTR_DIRECTORY) 534 return; 535 #endif 536 vp = DETOV(dep); 537 dep->de_inode = (uint64_t)dep->de_pmp->pm_bpcluster * dep->de_dirclust + 538 dep->de_diroffset; 539 vfs_hash_rehash(vp, dep->de_inode); 540 } 541 542 int 543 msdosfs_reclaim(ap) 544 struct vop_reclaim_args /* { 545 struct vnode *a_vp; 546 } */ *ap; 547 { 548 struct vnode *vp = ap->a_vp; 549 struct denode *dep = VTODE(vp); 550 551 #ifdef MSDOSFS_DEBUG 552 printf("msdosfs_reclaim(): dep %p, file %s, refcnt %ld\n", 553 dep, dep->de_Name, dep->de_refcnt); 554 #endif 555 556 if (prtactive && vrefcnt(vp) != 0) 557 vprint("msdosfs_reclaim(): pushing active", vp); 558 /* 559 * Destroy the vm object and flush associated pages. 560 */ 561 vnode_destroy_vobject(vp); 562 /* 563 * Remove the denode from its hash chain. 564 */ 565 vfs_hash_remove(vp); 566 /* 567 * Purge old data structures associated with the denode. 568 */ 569 #if 0 /* XXX */ 570 dep->de_flag = 0; 571 #endif 572 FREE(dep, M_MSDOSFSNODE); 573 vp->v_data = NULL; 574 575 return (0); 576 } 577 578 int 579 msdosfs_inactive(ap) 580 struct vop_inactive_args /* { 581 struct vnode *a_vp; 582 struct thread *a_td; 583 } */ *ap; 584 { 585 struct vnode *vp = ap->a_vp; 586 struct denode *dep = VTODE(vp); 587 struct thread *td = ap->a_td; 588 int error = 0; 589 590 #ifdef MSDOSFS_DEBUG 591 printf("msdosfs_inactive(): dep %p, de_Name[0] %x\n", dep, dep->de_Name[0]); 592 #endif 593 594 if (prtactive && vrefcnt(vp) != 0) 595 vprint("msdosfs_inactive(): pushing active", vp); 596 597 /* 598 * Ignore denodes related to stale file handles. 599 */ 600 if (dep->de_Name[0] == SLOT_DELETED) 601 goto out; 602 603 /* 604 * If the file has been deleted and it is on a read/write 605 * filesystem, then truncate the file, and mark the directory slot 606 * as empty. (This may not be necessary for the dos filesystem.) 607 */ 608 #ifdef MSDOSFS_DEBUG 609 printf("msdosfs_inactive(): dep %p, refcnt %ld, mntflag %x, MNT_RDONLY %x\n", 610 dep, dep->de_refcnt, vp->v_mount->mnt_flag, MNT_RDONLY); 611 #endif 612 if (dep->de_refcnt <= 0 && (vp->v_mount->mnt_flag & MNT_RDONLY) == 0) { 613 error = detrunc(dep, (u_long) 0, 0, NOCRED, td); 614 dep->de_flag |= DE_UPDATE; 615 dep->de_Name[0] = SLOT_DELETED; 616 } 617 deupdat(dep, 0); 618 619 out: 620 /* 621 * If we are done with the denode, reclaim it 622 * so that it can be reused immediately. 623 */ 624 #ifdef MSDOSFS_DEBUG 625 printf("msdosfs_inactive(): v_usecount %d, de_Name[0] %x\n", 626 vrefcnt(vp), dep->de_Name[0]); 627 #endif 628 if (dep->de_Name[0] == SLOT_DELETED) 629 vrecycle(vp, td); 630 return (error); 631 }
Cache object: 74e4bdc82840e29764eee35d1ab568d6
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