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sys/fs/msdosfs/msdosfs_vfsops.c
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1 /* $FreeBSD: releng/8.4/sys/fs/msdosfs/msdosfs_vfsops.c 247686 2013-03-03 07:27:15Z kib $ */ 2 /* $NetBSD: msdosfs_vfsops.c,v 1.51 1997/11/17 15:36:58 ws 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/conf.h> 55 #include <sys/fcntl.h> 56 #include <sys/iconv.h> 57 #include <sys/kernel.h> 58 #include <sys/lock.h> 59 #include <sys/malloc.h> 60 #include <sys/mount.h> 61 #include <sys/mutex.h> 62 #include <sys/namei.h> 63 #include <sys/priv.h> 64 #include <sys/proc.h> 65 #include <sys/stat.h> 66 #include <sys/vnode.h> 67 68 #include <geom/geom.h> 69 #include <geom/geom_vfs.h> 70 71 #include <fs/msdosfs/bootsect.h> 72 #include <fs/msdosfs/bpb.h> 73 #include <fs/msdosfs/direntry.h> 74 #include <fs/msdosfs/denode.h> 75 #include <fs/msdosfs/fat.h> 76 #include <fs/msdosfs/msdosfsmount.h> 77 78 static const char msdosfs_lock_msg[] = "fatlk"; 79 80 /* Mount options that we support. */ 81 static const char *msdosfs_opts[] = { 82 "async", "noatime", "noclusterr", "noclusterw", 83 "export", "force", "from", "sync", 84 "cs_dos", "cs_local", "cs_win", "dirmask", 85 "gid", "kiconv", "large", "longname", 86 "longnames", "mask", "shortname", "shortnames", 87 "uid", "win95", "nowin95", 88 NULL 89 }; 90 91 #if 1 /*def PC98*/ 92 /* 93 * XXX - The boot signature formatted by NEC PC-98 DOS looks like a 94 * garbage or a random value :-{ 95 * If you want to use that broken-signatured media, define the 96 * following symbol even though PC/AT. 97 * (ex. mount PC-98 DOS formatted FD on PC/AT) 98 */ 99 #define MSDOSFS_NOCHECKSIG 100 #endif 101 102 MALLOC_DEFINE(M_MSDOSFSMNT, "msdosfs_mount", "MSDOSFS mount structure"); 103 static MALLOC_DEFINE(M_MSDOSFSFAT, "msdosfs_fat", "MSDOSFS file allocation table"); 104 105 struct iconv_functions *msdosfs_iconv; 106 107 static int update_mp(struct mount *mp, struct thread *td); 108 static int mountmsdosfs(struct vnode *devvp, struct mount *mp); 109 static vfs_fhtovp_t msdosfs_fhtovp; 110 static vfs_mount_t msdosfs_mount; 111 static vfs_root_t msdosfs_root; 112 static vfs_statfs_t msdosfs_statfs; 113 static vfs_sync_t msdosfs_sync; 114 static vfs_unmount_t msdosfs_unmount; 115 116 /* Maximum length of a character set name (arbitrary). */ 117 #define MAXCSLEN 64 118 119 static int 120 update_mp(struct mount *mp, struct thread *td) 121 { 122 struct msdosfsmount *pmp = VFSTOMSDOSFS(mp); 123 void *dos, *win, *local; 124 int error, v; 125 126 if (!vfs_getopt(mp->mnt_optnew, "kiconv", NULL, NULL)) { 127 if (msdosfs_iconv != NULL) { 128 error = vfs_getopt(mp->mnt_optnew, 129 "cs_win", &win, NULL); 130 if (!error) 131 error = vfs_getopt(mp->mnt_optnew, 132 "cs_local", &local, NULL); 133 if (!error) 134 error = vfs_getopt(mp->mnt_optnew, 135 "cs_dos", &dos, NULL); 136 if (!error) { 137 msdosfs_iconv->open(win, local, &pmp->pm_u2w); 138 msdosfs_iconv->open(local, win, &pmp->pm_w2u); 139 msdosfs_iconv->open(dos, local, &pmp->pm_u2d); 140 msdosfs_iconv->open(local, dos, &pmp->pm_d2u); 141 } 142 if (error != 0) 143 return (error); 144 } else { 145 pmp->pm_w2u = NULL; 146 pmp->pm_u2w = NULL; 147 pmp->pm_d2u = NULL; 148 pmp->pm_u2d = NULL; 149 } 150 } 151 152 if (1 == vfs_scanopt(mp->mnt_optnew, "gid", "%d", &v)) 153 pmp->pm_gid = v; 154 if (1 == vfs_scanopt(mp->mnt_optnew, "uid", "%d", &v)) 155 pmp->pm_uid = v; 156 if (1 == vfs_scanopt(mp->mnt_optnew, "mask", "%d", &v)) 157 pmp->pm_mask = v & ALLPERMS; 158 if (1 == vfs_scanopt(mp->mnt_optnew, "dirmask", "%d", &v)) 159 pmp->pm_dirmask = v & ALLPERMS; 160 vfs_flagopt(mp->mnt_optnew, "shortname", 161 &pmp->pm_flags, MSDOSFSMNT_SHORTNAME); 162 vfs_flagopt(mp->mnt_optnew, "shortnames", 163 &pmp->pm_flags, MSDOSFSMNT_SHORTNAME); 164 vfs_flagopt(mp->mnt_optnew, "longname", 165 &pmp->pm_flags, MSDOSFSMNT_LONGNAME); 166 vfs_flagopt(mp->mnt_optnew, "longnames", 167 &pmp->pm_flags, MSDOSFSMNT_LONGNAME); 168 vfs_flagopt(mp->mnt_optnew, "kiconv", 169 &pmp->pm_flags, MSDOSFSMNT_KICONV); 170 171 if (vfs_getopt(mp->mnt_optnew, "nowin95", NULL, NULL) == 0) 172 pmp->pm_flags |= MSDOSFSMNT_NOWIN95; 173 else 174 pmp->pm_flags &= ~MSDOSFSMNT_NOWIN95; 175 176 if (pmp->pm_flags & MSDOSFSMNT_NOWIN95) 177 pmp->pm_flags |= MSDOSFSMNT_SHORTNAME; 178 else if (!(pmp->pm_flags & 179 (MSDOSFSMNT_SHORTNAME | MSDOSFSMNT_LONGNAME))) { 180 struct vnode *rootvp; 181 182 /* 183 * Try to divine whether to support Win'95 long filenames 184 */ 185 if (FAT32(pmp)) 186 pmp->pm_flags |= MSDOSFSMNT_LONGNAME; 187 else { 188 if ((error = 189 msdosfs_root(mp, LK_EXCLUSIVE, &rootvp)) != 0) 190 return error; 191 pmp->pm_flags |= findwin95(VTODE(rootvp)) ? 192 MSDOSFSMNT_LONGNAME : MSDOSFSMNT_SHORTNAME; 193 vput(rootvp); 194 } 195 } 196 return 0; 197 } 198 199 static int 200 msdosfs_cmount(struct mntarg *ma, void *data, int flags) 201 { 202 struct msdosfs_args args; 203 struct export_args exp; 204 int error; 205 206 if (data == NULL) 207 return (EINVAL); 208 error = copyin(data, &args, sizeof args); 209 if (error) 210 return (error); 211 vfs_oexport_conv(&args.export, &exp); 212 213 ma = mount_argsu(ma, "from", args.fspec, MAXPATHLEN); 214 ma = mount_arg(ma, "export", &exp, sizeof(exp)); 215 ma = mount_argf(ma, "uid", "%d", args.uid); 216 ma = mount_argf(ma, "gid", "%d", args.gid); 217 ma = mount_argf(ma, "mask", "%d", args.mask); 218 ma = mount_argf(ma, "dirmask", "%d", args.dirmask); 219 220 ma = mount_argb(ma, args.flags & MSDOSFSMNT_SHORTNAME, "noshortname"); 221 ma = mount_argb(ma, args.flags & MSDOSFSMNT_LONGNAME, "nolongname"); 222 ma = mount_argb(ma, !(args.flags & MSDOSFSMNT_NOWIN95), "nowin95"); 223 ma = mount_argb(ma, args.flags & MSDOSFSMNT_KICONV, "nokiconv"); 224 225 ma = mount_argsu(ma, "cs_win", args.cs_win, MAXCSLEN); 226 ma = mount_argsu(ma, "cs_dos", args.cs_dos, MAXCSLEN); 227 ma = mount_argsu(ma, "cs_local", args.cs_local, MAXCSLEN); 228 229 error = kernel_mount(ma, flags); 230 231 return (error); 232 } 233 234 /* 235 * mp - path - addr in user space of mount point (ie /usr or whatever) 236 * data - addr in user space of mount params including the name of the block 237 * special file to treat as a filesystem. 238 */ 239 static int 240 msdosfs_mount(struct mount *mp) 241 { 242 struct vnode *devvp; /* vnode for blk device to mount */ 243 struct thread *td; 244 /* msdosfs specific mount control block */ 245 struct msdosfsmount *pmp = NULL; 246 struct nameidata ndp; 247 int error, flags; 248 accmode_t accmode; 249 char *from; 250 251 td = curthread; 252 if (vfs_filteropt(mp->mnt_optnew, msdosfs_opts)) 253 return (EINVAL); 254 255 /* 256 * If updating, check whether changing from read-only to 257 * read/write; if there is no device name, that's all we do. 258 */ 259 if (mp->mnt_flag & MNT_UPDATE) { 260 pmp = VFSTOMSDOSFS(mp); 261 if (vfs_flagopt(mp->mnt_optnew, "export", NULL, 0)) { 262 /* 263 * Forbid export requests if filesystem has 264 * MSDOSFS_LARGEFS flag set. 265 */ 266 if ((pmp->pm_flags & MSDOSFS_LARGEFS) != 0) { 267 vfs_mount_error(mp, 268 "MSDOSFS_LARGEFS flag set, cannot export"); 269 return (EOPNOTSUPP); 270 } 271 } 272 if (!(pmp->pm_flags & MSDOSFSMNT_RONLY) && 273 vfs_flagopt(mp->mnt_optnew, "ro", NULL, 0)) { 274 error = VFS_SYNC(mp, MNT_WAIT); 275 if (error) 276 return (error); 277 flags = WRITECLOSE; 278 if (mp->mnt_flag & MNT_FORCE) 279 flags |= FORCECLOSE; 280 error = vflush(mp, 0, flags, td); 281 if (error) 282 return (error); 283 284 /* 285 * Now the volume is clean. Mark it so while the 286 * device is still rw. 287 */ 288 error = markvoldirty(pmp, 0); 289 if (error) { 290 (void)markvoldirty(pmp, 1); 291 return (error); 292 } 293 294 /* Downgrade the device from rw to ro. */ 295 DROP_GIANT(); 296 g_topology_lock(); 297 error = g_access(pmp->pm_cp, 0, -1, 0); 298 g_topology_unlock(); 299 PICKUP_GIANT(); 300 if (error) { 301 (void)markvoldirty(pmp, 1); 302 return (error); 303 } 304 305 /* 306 * Backing out after an error was painful in the 307 * above. Now we are committed to succeeding. 308 */ 309 pmp->pm_fmod = 0; 310 pmp->pm_flags |= MSDOSFSMNT_RONLY; 311 MNT_ILOCK(mp); 312 mp->mnt_flag |= MNT_RDONLY; 313 MNT_IUNLOCK(mp); 314 } else if ((pmp->pm_flags & MSDOSFSMNT_RONLY) && 315 !vfs_flagopt(mp->mnt_optnew, "ro", NULL, 0)) { 316 /* 317 * If upgrade to read-write by non-root, then verify 318 * that user has necessary permissions on the device. 319 */ 320 devvp = pmp->pm_devvp; 321 vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY); 322 error = VOP_ACCESS(devvp, VREAD | VWRITE, 323 td->td_ucred, td); 324 if (error) 325 error = priv_check(td, PRIV_VFS_MOUNT_PERM); 326 if (error) { 327 VOP_UNLOCK(devvp, 0); 328 return (error); 329 } 330 VOP_UNLOCK(devvp, 0); 331 DROP_GIANT(); 332 g_topology_lock(); 333 error = g_access(pmp->pm_cp, 0, 1, 0); 334 g_topology_unlock(); 335 PICKUP_GIANT(); 336 if (error) 337 return (error); 338 339 pmp->pm_fmod = 1; 340 pmp->pm_flags &= ~MSDOSFSMNT_RONLY; 341 MNT_ILOCK(mp); 342 mp->mnt_flag &= ~MNT_RDONLY; 343 MNT_IUNLOCK(mp); 344 345 /* Now that the volume is modifiable, mark it dirty. */ 346 error = markvoldirty(pmp, 1); 347 if (error) 348 return (error); 349 } 350 } 351 /* 352 * Not an update, or updating the name: look up the name 353 * and verify that it refers to a sensible disk device. 354 */ 355 if (vfs_getopt(mp->mnt_optnew, "from", (void **)&from, NULL)) 356 return (EINVAL); 357 NDINIT(&ndp, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, from, td); 358 error = namei(&ndp); 359 if (error) 360 return (error); 361 devvp = ndp.ni_vp; 362 NDFREE(&ndp, NDF_ONLY_PNBUF); 363 364 if (!vn_isdisk(devvp, &error)) { 365 vput(devvp); 366 return (error); 367 } 368 /* 369 * If mount by non-root, then verify that user has necessary 370 * permissions on the device. 371 */ 372 accmode = VREAD; 373 if ((mp->mnt_flag & MNT_RDONLY) == 0) 374 accmode |= VWRITE; 375 error = VOP_ACCESS(devvp, accmode, td->td_ucred, td); 376 if (error) 377 error = priv_check(td, PRIV_VFS_MOUNT_PERM); 378 if (error) { 379 vput(devvp); 380 return (error); 381 } 382 if ((mp->mnt_flag & MNT_UPDATE) == 0) { 383 error = mountmsdosfs(devvp, mp); 384 #ifdef MSDOSFS_DEBUG /* only needed for the printf below */ 385 pmp = VFSTOMSDOSFS(mp); 386 #endif 387 } else { 388 vput(devvp); 389 if (devvp != pmp->pm_devvp) 390 return (EINVAL); /* XXX needs translation */ 391 } 392 if (error) { 393 vrele(devvp); 394 return (error); 395 } 396 397 error = update_mp(mp, td); 398 if (error) { 399 if ((mp->mnt_flag & MNT_UPDATE) == 0) 400 msdosfs_unmount(mp, MNT_FORCE); 401 return error; 402 } 403 404 vfs_mountedfrom(mp, from); 405 #ifdef MSDOSFS_DEBUG 406 printf("msdosfs_mount(): mp %p, pmp %p, inusemap %p\n", mp, pmp, pmp->pm_inusemap); 407 #endif 408 return (0); 409 } 410 411 static int 412 mountmsdosfs(struct vnode *devvp, struct mount *mp) 413 { 414 struct msdosfsmount *pmp; 415 struct buf *bp; 416 struct cdev *dev; 417 union bootsector *bsp; 418 struct byte_bpb33 *b33; 419 struct byte_bpb50 *b50; 420 struct byte_bpb710 *b710; 421 u_int8_t SecPerClust; 422 u_long clusters; 423 int ronly, error; 424 struct g_consumer *cp; 425 struct bufobj *bo; 426 427 bp = NULL; /* This and pmp both used in error_exit. */ 428 pmp = NULL; 429 ronly = (mp->mnt_flag & MNT_RDONLY) != 0; 430 431 dev = devvp->v_rdev; 432 dev_ref(dev); 433 DROP_GIANT(); 434 g_topology_lock(); 435 error = g_vfs_open(devvp, &cp, "msdosfs", ronly ? 0 : 1); 436 g_topology_unlock(); 437 PICKUP_GIANT(); 438 VOP_UNLOCK(devvp, 0); 439 if (error) 440 goto error_exit; 441 442 bo = &devvp->v_bufobj; 443 444 /* 445 * Read the boot sector of the filesystem, and then check the 446 * boot signature. If not a dos boot sector then error out. 447 * 448 * NOTE: 8192 is a magic size that works for ffs. 449 */ 450 error = bread(devvp, 0, 8192, NOCRED, &bp); 451 if (error) 452 goto error_exit; 453 bp->b_flags |= B_AGE; 454 bsp = (union bootsector *)bp->b_data; 455 b33 = (struct byte_bpb33 *)bsp->bs33.bsBPB; 456 b50 = (struct byte_bpb50 *)bsp->bs50.bsBPB; 457 b710 = (struct byte_bpb710 *)bsp->bs710.bsBPB; 458 459 #ifndef MSDOSFS_NOCHECKSIG 460 if (bsp->bs50.bsBootSectSig0 != BOOTSIG0 461 || bsp->bs50.bsBootSectSig1 != BOOTSIG1) { 462 error = EINVAL; 463 goto error_exit; 464 } 465 #endif 466 467 pmp = malloc(sizeof *pmp, M_MSDOSFSMNT, M_WAITOK | M_ZERO); 468 pmp->pm_mountp = mp; 469 pmp->pm_cp = cp; 470 pmp->pm_bo = bo; 471 472 lockinit(&pmp->pm_fatlock, 0, msdosfs_lock_msg, 0, 0); 473 474 /* 475 * Initialize ownerships and permissions, since nothing else will 476 * initialize them iff we are mounting root. 477 */ 478 pmp->pm_uid = UID_ROOT; 479 pmp->pm_gid = GID_WHEEL; 480 pmp->pm_mask = pmp->pm_dirmask = S_IXUSR | S_IXGRP | S_IXOTH | 481 S_IRUSR | S_IRGRP | S_IROTH | S_IWUSR; 482 483 /* 484 * Experimental support for large MS-DOS filesystems. 485 * WARNING: This uses at least 32 bytes of kernel memory (which is not 486 * reclaimed until the FS is unmounted) for each file on disk to map 487 * between the 32-bit inode numbers used by VFS and the 64-bit 488 * pseudo-inode numbers used internally by msdosfs. This is only 489 * safe to use in certain controlled situations (e.g. read-only FS 490 * with less than 1 million files). 491 * Since the mappings do not persist across unmounts (or reboots), these 492 * filesystems are not suitable for exporting through NFS, or any other 493 * application that requires fixed inode numbers. 494 */ 495 vfs_flagopt(mp->mnt_optnew, "large", &pmp->pm_flags, MSDOSFS_LARGEFS); 496 497 /* 498 * Compute several useful quantities from the bpb in the 499 * bootsector. Copy in the dos 5 variant of the bpb then fix up 500 * the fields that are different between dos 5 and dos 3.3. 501 */ 502 SecPerClust = b50->bpbSecPerClust; 503 pmp->pm_BytesPerSec = getushort(b50->bpbBytesPerSec); 504 if (pmp->pm_BytesPerSec < DEV_BSIZE) { 505 error = EINVAL; 506 goto error_exit; 507 } 508 pmp->pm_ResSectors = getushort(b50->bpbResSectors); 509 pmp->pm_FATs = b50->bpbFATs; 510 pmp->pm_RootDirEnts = getushort(b50->bpbRootDirEnts); 511 pmp->pm_Sectors = getushort(b50->bpbSectors); 512 pmp->pm_FATsecs = getushort(b50->bpbFATsecs); 513 pmp->pm_SecPerTrack = getushort(b50->bpbSecPerTrack); 514 pmp->pm_Heads = getushort(b50->bpbHeads); 515 pmp->pm_Media = b50->bpbMedia; 516 517 /* calculate the ratio of sector size to DEV_BSIZE */ 518 pmp->pm_BlkPerSec = pmp->pm_BytesPerSec / DEV_BSIZE; 519 520 /* 521 * We don't check pm_Heads nor pm_SecPerTrack, because 522 * these may not be set for EFI file systems. We don't 523 * use these anyway, so we're unaffected if they are 524 * invalid. 525 */ 526 if (!pmp->pm_BytesPerSec || !SecPerClust) { 527 error = EINVAL; 528 goto error_exit; 529 } 530 531 if (pmp->pm_Sectors == 0) { 532 pmp->pm_HiddenSects = getulong(b50->bpbHiddenSecs); 533 pmp->pm_HugeSectors = getulong(b50->bpbHugeSectors); 534 } else { 535 pmp->pm_HiddenSects = getushort(b33->bpbHiddenSecs); 536 pmp->pm_HugeSectors = pmp->pm_Sectors; 537 } 538 if (!(pmp->pm_flags & MSDOSFS_LARGEFS)) { 539 if (pmp->pm_HugeSectors > 0xffffffff / 540 (pmp->pm_BytesPerSec / sizeof(struct direntry)) + 1) { 541 /* 542 * We cannot deal currently with this size of disk 543 * due to fileid limitations (see msdosfs_getattr and 544 * msdosfs_readdir) 545 */ 546 error = EINVAL; 547 vfs_mount_error(mp, 548 "Disk too big, try '-o large' mount option"); 549 goto error_exit; 550 } 551 } 552 553 if (pmp->pm_RootDirEnts == 0) { 554 if (pmp->pm_FATsecs 555 || getushort(b710->bpbFSVers)) { 556 error = EINVAL; 557 #ifdef MSDOSFS_DEBUG 558 printf("mountmsdosfs(): bad FAT32 filesystem\n"); 559 #endif 560 goto error_exit; 561 } 562 pmp->pm_fatmask = FAT32_MASK; 563 pmp->pm_fatmult = 4; 564 pmp->pm_fatdiv = 1; 565 pmp->pm_FATsecs = getulong(b710->bpbBigFATsecs); 566 if (getushort(b710->bpbExtFlags) & FATMIRROR) 567 pmp->pm_curfat = getushort(b710->bpbExtFlags) & FATNUM; 568 else 569 pmp->pm_flags |= MSDOSFS_FATMIRROR; 570 } else 571 pmp->pm_flags |= MSDOSFS_FATMIRROR; 572 573 /* 574 * Check a few values (could do some more): 575 * - logical sector size: power of 2, >= block size 576 * - sectors per cluster: power of 2, >= 1 577 * - number of sectors: >= 1, <= size of partition 578 * - number of FAT sectors: >= 1 579 */ 580 if ( (SecPerClust == 0) 581 || (SecPerClust & (SecPerClust - 1)) 582 || (pmp->pm_BytesPerSec < DEV_BSIZE) 583 || (pmp->pm_BytesPerSec & (pmp->pm_BytesPerSec - 1)) 584 || (pmp->pm_HugeSectors == 0) 585 || (pmp->pm_FATsecs == 0) 586 || (SecPerClust * pmp->pm_BlkPerSec > MAXBSIZE / DEV_BSIZE) 587 ) { 588 error = EINVAL; 589 goto error_exit; 590 } 591 592 pmp->pm_HugeSectors *= pmp->pm_BlkPerSec; 593 pmp->pm_HiddenSects *= pmp->pm_BlkPerSec; /* XXX not used? */ 594 pmp->pm_FATsecs *= pmp->pm_BlkPerSec; 595 SecPerClust *= pmp->pm_BlkPerSec; 596 597 pmp->pm_fatblk = pmp->pm_ResSectors * pmp->pm_BlkPerSec; 598 599 if (FAT32(pmp)) { 600 pmp->pm_rootdirblk = getulong(b710->bpbRootClust); 601 pmp->pm_firstcluster = pmp->pm_fatblk 602 + (pmp->pm_FATs * pmp->pm_FATsecs); 603 pmp->pm_fsinfo = getushort(b710->bpbFSInfo) * pmp->pm_BlkPerSec; 604 } else { 605 pmp->pm_rootdirblk = pmp->pm_fatblk + 606 (pmp->pm_FATs * pmp->pm_FATsecs); 607 pmp->pm_rootdirsize = (pmp->pm_RootDirEnts * sizeof(struct direntry) 608 + DEV_BSIZE - 1) 609 / DEV_BSIZE; /* in blocks */ 610 pmp->pm_firstcluster = pmp->pm_rootdirblk + pmp->pm_rootdirsize; 611 } 612 613 pmp->pm_maxcluster = (pmp->pm_HugeSectors - pmp->pm_firstcluster) / 614 SecPerClust + 1; 615 pmp->pm_fatsize = pmp->pm_FATsecs * DEV_BSIZE; /* XXX not used? */ 616 617 if (pmp->pm_fatmask == 0) { 618 if (pmp->pm_maxcluster 619 <= ((CLUST_RSRVD - CLUST_FIRST) & FAT12_MASK)) { 620 /* 621 * This will usually be a floppy disk. This size makes 622 * sure that one fat entry will not be split across 623 * multiple blocks. 624 */ 625 pmp->pm_fatmask = FAT12_MASK; 626 pmp->pm_fatmult = 3; 627 pmp->pm_fatdiv = 2; 628 } else { 629 pmp->pm_fatmask = FAT16_MASK; 630 pmp->pm_fatmult = 2; 631 pmp->pm_fatdiv = 1; 632 } 633 } 634 635 clusters = (pmp->pm_fatsize / pmp->pm_fatmult) * pmp->pm_fatdiv; 636 if (pmp->pm_maxcluster >= clusters) { 637 #ifdef MSDOSFS_DEBUG 638 printf("Warning: number of clusters (%ld) exceeds FAT " 639 "capacity (%ld)\n", pmp->pm_maxcluster + 1, clusters); 640 #endif 641 pmp->pm_maxcluster = clusters - 1; 642 } 643 644 if (FAT12(pmp)) 645 pmp->pm_fatblocksize = 3 * 512; 646 else 647 pmp->pm_fatblocksize = PAGE_SIZE; 648 pmp->pm_fatblocksize = roundup(pmp->pm_fatblocksize, 649 pmp->pm_BytesPerSec); 650 pmp->pm_fatblocksec = pmp->pm_fatblocksize / DEV_BSIZE; 651 pmp->pm_bnshift = ffs(DEV_BSIZE) - 1; 652 653 /* 654 * Compute mask and shift value for isolating cluster relative byte 655 * offsets and cluster numbers from a file offset. 656 */ 657 pmp->pm_bpcluster = SecPerClust * DEV_BSIZE; 658 pmp->pm_crbomask = pmp->pm_bpcluster - 1; 659 pmp->pm_cnshift = ffs(pmp->pm_bpcluster) - 1; 660 661 /* 662 * Check for valid cluster size 663 * must be a power of 2 664 */ 665 if (pmp->pm_bpcluster ^ (1 << pmp->pm_cnshift)) { 666 error = EINVAL; 667 goto error_exit; 668 } 669 670 /* 671 * Release the bootsector buffer. 672 */ 673 brelse(bp); 674 bp = NULL; 675 676 /* 677 * Check the fsinfo sector if we have one. Silently fix up our 678 * in-core copy of fp->fsinxtfree if it is unknown (0xffffffff) 679 * or too large. Ignore fp->fsinfree for now, since we need to 680 * read the entire FAT anyway to fill the inuse map. 681 */ 682 if (pmp->pm_fsinfo) { 683 struct fsinfo *fp; 684 685 if ((error = bread(devvp, pmp->pm_fsinfo, pmp->pm_BytesPerSec, 686 NOCRED, &bp)) != 0) 687 goto error_exit; 688 fp = (struct fsinfo *)bp->b_data; 689 if (!bcmp(fp->fsisig1, "RRaA", 4) 690 && !bcmp(fp->fsisig2, "rrAa", 4) 691 && !bcmp(fp->fsisig3, "\0\0\125\252", 4)) { 692 pmp->pm_nxtfree = getulong(fp->fsinxtfree); 693 if (pmp->pm_nxtfree > pmp->pm_maxcluster) 694 pmp->pm_nxtfree = CLUST_FIRST; 695 } else 696 pmp->pm_fsinfo = 0; 697 brelse(bp); 698 bp = NULL; 699 } 700 701 /* 702 * Finish initializing pmp->pm_nxtfree (just in case the first few 703 * sectors aren't properly reserved in the FAT). This completes 704 * the fixup for fp->fsinxtfree, and fixes up the zero-initialized 705 * value if there is no fsinfo. We will use pmp->pm_nxtfree 706 * internally even if there is no fsinfo. 707 */ 708 if (pmp->pm_nxtfree < CLUST_FIRST) 709 pmp->pm_nxtfree = CLUST_FIRST; 710 711 /* 712 * Allocate memory for the bitmap of allocated clusters, and then 713 * fill it in. 714 */ 715 pmp->pm_inusemap = malloc(howmany(pmp->pm_maxcluster + 1, N_INUSEBITS) 716 * sizeof(*pmp->pm_inusemap), 717 M_MSDOSFSFAT, M_WAITOK); 718 719 /* 720 * fillinusemap() needs pm_devvp. 721 */ 722 pmp->pm_devvp = devvp; 723 pmp->pm_dev = dev; 724 725 /* 726 * Have the inuse map filled in. 727 */ 728 MSDOSFS_LOCK_MP(pmp); 729 error = fillinusemap(pmp); 730 MSDOSFS_UNLOCK_MP(pmp); 731 if (error != 0) 732 goto error_exit; 733 734 /* 735 * If they want fat updates to be synchronous then let them suffer 736 * the performance degradation in exchange for the on disk copy of 737 * the fat being correct just about all the time. I suppose this 738 * would be a good thing to turn on if the kernel is still flakey. 739 */ 740 if (mp->mnt_flag & MNT_SYNCHRONOUS) 741 pmp->pm_flags |= MSDOSFSMNT_WAITONFAT; 742 743 /* 744 * Finish up. 745 */ 746 if (ronly) 747 pmp->pm_flags |= MSDOSFSMNT_RONLY; 748 else { 749 if ((error = markvoldirty(pmp, 1)) != 0) { 750 (void)markvoldirty(pmp, 0); 751 goto error_exit; 752 } 753 pmp->pm_fmod = 1; 754 } 755 mp->mnt_data = pmp; 756 mp->mnt_stat.f_fsid.val[0] = dev2udev(dev); 757 mp->mnt_stat.f_fsid.val[1] = mp->mnt_vfc->vfc_typenum; 758 MNT_ILOCK(mp); 759 mp->mnt_flag |= MNT_LOCAL; 760 mp->mnt_kern_flag |= MNTK_MPSAFE; 761 MNT_IUNLOCK(mp); 762 763 if (pmp->pm_flags & MSDOSFS_LARGEFS) 764 msdosfs_fileno_init(mp); 765 766 return 0; 767 768 error_exit: 769 if (bp) 770 brelse(bp); 771 if (cp != NULL) { 772 DROP_GIANT(); 773 g_topology_lock(); 774 g_vfs_close(cp); 775 g_topology_unlock(); 776 PICKUP_GIANT(); 777 } 778 if (pmp) { 779 lockdestroy(&pmp->pm_fatlock); 780 if (pmp->pm_inusemap) 781 free(pmp->pm_inusemap, M_MSDOSFSFAT); 782 free(pmp, M_MSDOSFSMNT); 783 mp->mnt_data = NULL; 784 } 785 dev_rel(dev); 786 return (error); 787 } 788 789 /* 790 * Unmount the filesystem described by mp. 791 */ 792 static int 793 msdosfs_unmount(struct mount *mp, int mntflags) 794 { 795 struct msdosfsmount *pmp; 796 int error, flags; 797 798 flags = 0; 799 if (mntflags & MNT_FORCE) 800 flags |= FORCECLOSE; 801 error = vflush(mp, 0, flags, curthread); 802 if (error && error != ENXIO) 803 return error; 804 pmp = VFSTOMSDOSFS(mp); 805 if ((pmp->pm_flags & MSDOSFSMNT_RONLY) == 0) { 806 error = markvoldirty(pmp, 0); 807 if (error && error != ENXIO) { 808 (void)markvoldirty(pmp, 1); 809 return (error); 810 } 811 } 812 if (pmp->pm_flags & MSDOSFSMNT_KICONV && msdosfs_iconv) { 813 if (pmp->pm_w2u) 814 msdosfs_iconv->close(pmp->pm_w2u); 815 if (pmp->pm_u2w) 816 msdosfs_iconv->close(pmp->pm_u2w); 817 if (pmp->pm_d2u) 818 msdosfs_iconv->close(pmp->pm_d2u); 819 if (pmp->pm_u2d) 820 msdosfs_iconv->close(pmp->pm_u2d); 821 } 822 823 #ifdef MSDOSFS_DEBUG 824 { 825 struct vnode *vp = pmp->pm_devvp; 826 struct bufobj *bo; 827 828 bo = &vp->v_bufobj; 829 BO_LOCK(bo); 830 VI_LOCK(vp); 831 vn_printf(vp, 832 "msdosfs_umount(): just before calling VOP_CLOSE()\n"); 833 printf("freef %p, freeb %p, mount %p\n", 834 TAILQ_NEXT(vp, v_freelist), vp->v_freelist.tqe_prev, 835 vp->v_mount); 836 printf("cleanblkhd %p, dirtyblkhd %p, numoutput %ld, type %d\n", 837 TAILQ_FIRST(&vp->v_bufobj.bo_clean.bv_hd), 838 TAILQ_FIRST(&vp->v_bufobj.bo_dirty.bv_hd), 839 vp->v_bufobj.bo_numoutput, vp->v_type); 840 VI_UNLOCK(vp); 841 BO_UNLOCK(bo); 842 } 843 #endif 844 DROP_GIANT(); 845 g_topology_lock(); 846 g_vfs_close(pmp->pm_cp); 847 g_topology_unlock(); 848 PICKUP_GIANT(); 849 vrele(pmp->pm_devvp); 850 dev_rel(pmp->pm_dev); 851 free(pmp->pm_inusemap, M_MSDOSFSFAT); 852 if (pmp->pm_flags & MSDOSFS_LARGEFS) 853 msdosfs_fileno_free(mp); 854 lockdestroy(&pmp->pm_fatlock); 855 free(pmp, M_MSDOSFSMNT); 856 mp->mnt_data = NULL; 857 MNT_ILOCK(mp); 858 mp->mnt_flag &= ~MNT_LOCAL; 859 MNT_IUNLOCK(mp); 860 return (error); 861 } 862 863 static int 864 msdosfs_root(struct mount *mp, int flags, struct vnode **vpp) 865 { 866 struct msdosfsmount *pmp = VFSTOMSDOSFS(mp); 867 struct denode *ndep; 868 int error; 869 870 #ifdef MSDOSFS_DEBUG 871 printf("msdosfs_root(); mp %p, pmp %p\n", mp, pmp); 872 #endif 873 error = deget(pmp, MSDOSFSROOT, MSDOSFSROOT_OFS, &ndep); 874 if (error) 875 return (error); 876 *vpp = DETOV(ndep); 877 return (0); 878 } 879 880 static int 881 msdosfs_statfs(struct mount *mp, struct statfs *sbp) 882 { 883 struct msdosfsmount *pmp; 884 885 pmp = VFSTOMSDOSFS(mp); 886 sbp->f_bsize = pmp->pm_bpcluster; 887 sbp->f_iosize = pmp->pm_bpcluster; 888 sbp->f_blocks = pmp->pm_maxcluster + 1; 889 sbp->f_bfree = pmp->pm_freeclustercount; 890 sbp->f_bavail = pmp->pm_freeclustercount; 891 sbp->f_files = pmp->pm_RootDirEnts; /* XXX */ 892 sbp->f_ffree = 0; /* what to put in here? */ 893 return (0); 894 } 895 896 /* 897 * If we have an FSInfo block, update it. 898 */ 899 static int 900 msdosfs_fsiflush(struct msdosfsmount *pmp, int waitfor) 901 { 902 struct fsinfo *fp; 903 struct buf *bp; 904 int error; 905 906 MSDOSFS_LOCK_MP(pmp); 907 if (pmp->pm_fsinfo == 0 || (pmp->pm_flags & MSDOSFS_FSIMOD) == 0) { 908 error = 0; 909 goto unlock; 910 } 911 error = bread(pmp->pm_devvp, pmp->pm_fsinfo, pmp->pm_BytesPerSec, 912 NOCRED, &bp); 913 if (error != 0) { 914 brelse(bp); 915 goto unlock; 916 } 917 fp = (struct fsinfo *)bp->b_data; 918 putulong(fp->fsinfree, pmp->pm_freeclustercount); 919 putulong(fp->fsinxtfree, pmp->pm_nxtfree); 920 pmp->pm_flags &= ~MSDOSFS_FSIMOD; 921 if (waitfor == MNT_WAIT) 922 error = bwrite(bp); 923 else 924 bawrite(bp); 925 unlock: 926 MSDOSFS_UNLOCK_MP(pmp); 927 return (error); 928 } 929 930 static int 931 msdosfs_sync(struct mount *mp, int waitfor) 932 { 933 struct vnode *vp, *nvp; 934 struct thread *td; 935 struct denode *dep; 936 struct msdosfsmount *pmp = VFSTOMSDOSFS(mp); 937 int error, allerror = 0; 938 939 td = curthread; 940 941 /* 942 * If we ever switch to not updating all of the fats all the time, 943 * this would be the place to update them from the first one. 944 */ 945 if (pmp->pm_fmod != 0) { 946 if (pmp->pm_flags & MSDOSFSMNT_RONLY) 947 panic("msdosfs_sync: rofs mod"); 948 else { 949 /* update fats here */ 950 } 951 } 952 /* 953 * Write back each (modified) denode. 954 */ 955 MNT_ILOCK(mp); 956 loop: 957 MNT_VNODE_FOREACH(vp, mp, nvp) { 958 VI_LOCK(vp); 959 if (vp->v_type == VNON || (vp->v_iflag & VI_DOOMED)) { 960 VI_UNLOCK(vp); 961 continue; 962 } 963 MNT_IUNLOCK(mp); 964 dep = VTODE(vp); 965 if ((dep->de_flag & 966 (DE_ACCESS | DE_CREATE | DE_UPDATE | DE_MODIFIED)) == 0 && 967 (vp->v_bufobj.bo_dirty.bv_cnt == 0 || 968 waitfor == MNT_LAZY)) { 969 VI_UNLOCK(vp); 970 MNT_ILOCK(mp); 971 continue; 972 } 973 error = vget(vp, LK_EXCLUSIVE | LK_NOWAIT | LK_INTERLOCK, td); 974 if (error) { 975 MNT_ILOCK(mp); 976 if (error == ENOENT) 977 goto loop; 978 continue; 979 } 980 error = VOP_FSYNC(vp, waitfor, td); 981 if (error) 982 allerror = error; 983 VOP_UNLOCK(vp, 0); 984 vrele(vp); 985 MNT_ILOCK(mp); 986 } 987 MNT_IUNLOCK(mp); 988 989 /* 990 * Flush filesystem control info. 991 */ 992 if (waitfor != MNT_LAZY) { 993 vn_lock(pmp->pm_devvp, LK_EXCLUSIVE | LK_RETRY); 994 error = VOP_FSYNC(pmp->pm_devvp, waitfor, td); 995 if (error) 996 allerror = error; 997 VOP_UNLOCK(pmp->pm_devvp, 0); 998 } 999 1000 error = msdosfs_fsiflush(pmp, waitfor); 1001 if (error != 0) 1002 allerror = error; 1003 return (allerror); 1004 } 1005 1006 static int 1007 msdosfs_fhtovp(struct mount *mp, struct fid *fhp, struct vnode **vpp) 1008 { 1009 struct msdosfsmount *pmp = VFSTOMSDOSFS(mp); 1010 struct defid *defhp = (struct defid *) fhp; 1011 struct denode *dep; 1012 int error; 1013 1014 error = deget(pmp, defhp->defid_dirclust, defhp->defid_dirofs, &dep); 1015 if (error) { 1016 *vpp = NULLVP; 1017 return (error); 1018 } 1019 *vpp = DETOV(dep); 1020 vnode_create_vobject(*vpp, dep->de_FileSize, curthread); 1021 return (0); 1022 } 1023 1024 static struct vfsops msdosfs_vfsops = { 1025 .vfs_fhtovp = msdosfs_fhtovp, 1026 .vfs_mount = msdosfs_mount, 1027 .vfs_cmount = msdosfs_cmount, 1028 .vfs_root = msdosfs_root, 1029 .vfs_statfs = msdosfs_statfs, 1030 .vfs_sync = msdosfs_sync, 1031 .vfs_unmount = msdosfs_unmount, 1032 }; 1033 1034 VFS_SET(msdosfs_vfsops, msdosfs, 0); 1035 MODULE_VERSION(msdosfs, 1);
Cache object: 4def4b2517af30faaccffd1841113947
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