| 1 | /* |
| 2 | * Copyright (c) 1989, 1993 |
| 3 | * The Regents of the University of California. All rights reserved. |
| 4 | * (c) UNIX System Laboratories, Inc. |
| 5 | * All or some portions of this file are derived from material licensed |
| 6 | * to the University of California by American Telephone and Telegraph |
| 7 | * Co. or Unix System Laboratories, Inc. and are reproduced herein with |
| 8 | * the permission of UNIX System Laboratories, Inc. |
| 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 the University of |
| 21 | * California, Berkeley and its contributors. |
| 22 | * 4. Neither the name of the University nor the names of its contributors |
| 23 | * may be used to endorse or promote products derived from this software |
| 24 | * without specific prior written permission. |
| 25 | * |
| 26 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| 27 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 28 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 29 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 30 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 31 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 32 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 33 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 34 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 35 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 36 | * SUCH DAMAGE. |
| 37 | * |
| 38 | * @(#)ufs_lookup.c 8.15 (Berkeley) 6/16/95 |
| 39 | * $FreeBSD: src/sys/ufs/ufs/ufs_lookup.c,v 1.33.2.7 2001/09/22 19:22:13 iedowse Exp $ |
| 40 | * $DragonFly: src/sys/vfs/ufs/ufs_lookup.c,v 1.28 2006/12/23 00:41:30 swildner Exp $ |
| 41 | */ |
| 42 | |
| 43 | #include "opt_ufs.h" |
| 44 | |
| 45 | #include <sys/param.h> |
| 46 | #include <sys/systm.h> |
| 47 | #include <sys/kernel.h> |
| 48 | #include <sys/buf.h> |
| 49 | #include <sys/proc.h> |
| 50 | #include <sys/namei.h> |
| 51 | #include <sys/stat.h> |
| 52 | #include <sys/mount.h> |
| 53 | #include <sys/vnode.h> |
| 54 | #include <sys/sysctl.h> |
| 55 | |
| 56 | #include <vm/vm.h> |
| 57 | #include <vm/vm_extern.h> |
| 58 | |
| 59 | #include "quota.h" |
| 60 | #include "inode.h" |
| 61 | #include "dir.h" |
| 62 | #ifdef UFS_DIRHASH |
| 63 | #include "dirhash.h" |
| 64 | #endif |
| 65 | #include "ufsmount.h" |
| 66 | #include "ufs_extern.h" |
| 67 | #include "ffs_extern.h" |
| 68 | |
| 69 | #ifdef DIAGNOSTIC |
| 70 | int dirchk = 1; |
| 71 | #else |
| 72 | int dirchk = 0; |
| 73 | #endif |
| 74 | |
| 75 | SYSCTL_INT(_debug, OID_AUTO, dircheck, CTLFLAG_RW, &dirchk, 0, ""); |
| 76 | |
| 77 | /* true if old FS format...*/ |
| 78 | #define OFSFMT(vp) ((vp)->v_mount->mnt_maxsymlinklen <= 0) |
| 79 | |
| 80 | /* |
| 81 | * Convert a component of a pathname into a pointer to a locked inode. |
| 82 | * This is a very central and rather complicated routine. |
| 83 | * If the filesystem is not maintained in a strict tree hierarchy, |
| 84 | * this can result in a deadlock situation (see comments in code below). |
| 85 | * |
| 86 | * The cnp->cn_nameiop argument is LOOKUP, CREATE, RENAME, or DELETE depending |
| 87 | * on whether the name is to be looked up, created, renamed, or deleted. |
| 88 | * When CREATE, RENAME, or DELETE is specified, information usable in |
| 89 | * creating, renaming, or deleting a directory entry may be calculated. |
| 90 | * If flag has LOCKPARENT or'ed into it and the target of the pathname |
| 91 | * exists, lookup returns both the target and its parent directory locked. |
| 92 | * When creating or renaming and LOCKPARENT is specified, the target may |
| 93 | * not be ".". When deleting and LOCKPARENT is specified, the target may |
| 94 | * be "."., but the caller must check to ensure it does an vrele and vput |
| 95 | * instead of two vputs. |
| 96 | * |
| 97 | * Overall outline of ufs_lookup: |
| 98 | * |
| 99 | * search for name in directory, to found or notfound |
| 100 | * notfound: |
| 101 | * if creating, return locked directory, leaving info on available slots |
| 102 | * else return error |
| 103 | * found: |
| 104 | * if at end of path and deleting, return information to allow delete |
| 105 | * if at end of path and rewriting (RENAME and LOCKPARENT), lock target |
| 106 | * inode and return info to allow rewrite |
| 107 | * if not at end, add name to cache; if at end and neither creating |
| 108 | * nor deleting, add name to cache |
| 109 | * |
| 110 | * ufs_lookup(struct vnode *a_dvp, struct vnode **a_vpp, |
| 111 | * struct componentname *a_cnp) |
| 112 | */ |
| 113 | int |
| 114 | ufs_lookup(struct vop_old_lookup_args *ap) |
| 115 | { |
| 116 | struct vnode *vdp; /* vnode for directory being searched */ |
| 117 | struct inode *dp; /* inode for directory being searched */ |
| 118 | struct buf *bp; /* a buffer of directory entries */ |
| 119 | struct direct *ep; /* the current directory entry */ |
| 120 | int entryoffsetinblock; /* offset of ep in bp's buffer */ |
| 121 | enum {NONE, COMPACT, FOUND} slotstatus; |
| 122 | doff_t slotoffset; /* offset of area with free space */ |
| 123 | int slotsize; /* size of area at slotoffset */ |
| 124 | int slotfreespace; /* amount of space free in slot */ |
| 125 | int slotneeded; /* size of the entry we're seeking */ |
| 126 | int numdirpasses; /* strategy for directory search */ |
| 127 | doff_t endsearch; /* offset to end directory search */ |
| 128 | doff_t prevoff; /* prev entry dp->i_offset */ |
| 129 | struct vnode *pdp; /* saved dp during symlink work */ |
| 130 | struct vnode *tdp; /* returned by VFS_VGET */ |
| 131 | doff_t enduseful; /* pointer past last used dir slot */ |
| 132 | u_long bmask; /* block offset mask */ |
| 133 | int lockparent; /* 1 => lockparent flag is set */ |
| 134 | int wantparent; /* 1 => wantparent or lockparent flag */ |
| 135 | int namlen, error; |
| 136 | struct vnode **vpp = ap->a_vpp; |
| 137 | struct componentname *cnp = ap->a_cnp; |
| 138 | struct ucred *cred = cnp->cn_cred; |
| 139 | int flags = cnp->cn_flags; |
| 140 | int nameiop = cnp->cn_nameiop; |
| 141 | globaldata_t gd = mycpu; |
| 142 | |
| 143 | bp = NULL; |
| 144 | slotoffset = -1; |
| 145 | cnp->cn_flags &= ~CNP_PDIRUNLOCK; |
| 146 | /* |
| 147 | * XXX there was a soft-update diff about this I couldn't merge. |
| 148 | * I think this was the equiv. |
| 149 | */ |
| 150 | *vpp = NULL; |
| 151 | |
| 152 | vdp = ap->a_dvp; |
| 153 | dp = VTOI(vdp); |
| 154 | lockparent = flags & CNP_LOCKPARENT; |
| 155 | wantparent = flags & (CNP_LOCKPARENT|CNP_WANTPARENT); |
| 156 | |
| 157 | /* |
| 158 | * We now have a segment name to search for, and a directory to search. |
| 159 | * |
| 160 | * Suppress search for slots unless creating |
| 161 | * file and at end of pathname, in which case |
| 162 | * we watch for a place to put the new file in |
| 163 | * case it doesn't already exist. |
| 164 | */ |
| 165 | slotstatus = FOUND; |
| 166 | slotfreespace = slotsize = slotneeded = 0; |
| 167 | if (nameiop == NAMEI_CREATE || nameiop == NAMEI_RENAME) { |
| 168 | slotstatus = NONE; |
| 169 | slotneeded = DIRECTSIZ(cnp->cn_namelen); |
| 170 | } |
| 171 | bmask = VFSTOUFS(vdp->v_mount)->um_mountp->mnt_stat.f_iosize - 1; |
| 172 | |
| 173 | #ifdef UFS_DIRHASH |
| 174 | /* |
| 175 | * Use dirhash for fast operations on large directories. The logic |
| 176 | * to determine whether to hash the directory is contained within |
| 177 | * ufsdirhash_build(); a zero return means that it decided to hash |
| 178 | * this directory and it successfully built up the hash table. |
| 179 | */ |
| 180 | if (ufsdirhash_build(dp) == 0) { |
| 181 | /* Look for a free slot if needed. */ |
| 182 | enduseful = dp->i_size; |
| 183 | if (slotstatus != FOUND) { |
| 184 | slotoffset = ufsdirhash_findfree(dp, slotneeded, |
| 185 | &slotsize); |
| 186 | if (slotoffset >= 0) { |
| 187 | slotstatus = COMPACT; |
| 188 | enduseful = ufsdirhash_enduseful(dp); |
| 189 | if (enduseful < 0) |
| 190 | enduseful = dp->i_size; |
| 191 | } |
| 192 | } |
| 193 | /* Look up the component. */ |
| 194 | numdirpasses = 1; |
| 195 | entryoffsetinblock = 0; /* silence compiler warning */ |
| 196 | switch (ufsdirhash_lookup(dp, cnp->cn_nameptr, cnp->cn_namelen, |
| 197 | &dp->i_offset, &bp, nameiop == NAMEI_DELETE ? &prevoff : NULL)) { |
| 198 | case 0: |
| 199 | ep = (struct direct *)((char *)bp->b_data + |
| 200 | (dp->i_offset & bmask)); |
| 201 | goto foundentry; |
| 202 | case ENOENT: |
| 203 | dp->i_offset = roundup2(dp->i_size, DIRBLKSIZ); |
| 204 | goto notfound; |
| 205 | default: |
| 206 | /* Something failed; just do a linear search. */ |
| 207 | break; |
| 208 | } |
| 209 | } |
| 210 | #endif /* UFS_DIRHASH */ |
| 211 | /* |
| 212 | * If there is cached information on a previous search of |
| 213 | * this directory, pick up where we last left off. |
| 214 | * We cache only lookups as these are the most common |
| 215 | * and have the greatest payoff. Caching CREATE has little |
| 216 | * benefit as it usually must search the entire directory |
| 217 | * to determine that the entry does not exist. Caching the |
| 218 | * location of the last DELETE or RENAME has not reduced |
| 219 | * profiling time and hence has been removed in the interest |
| 220 | * of simplicity. |
| 221 | */ |
| 222 | if (nameiop != NAMEI_LOOKUP || dp->i_diroff == 0 || |
| 223 | dp->i_diroff >= dp->i_size) { |
| 224 | entryoffsetinblock = 0; |
| 225 | dp->i_offset = 0; |
| 226 | numdirpasses = 1; |
| 227 | } else { |
| 228 | dp->i_offset = dp->i_diroff; |
| 229 | if ((entryoffsetinblock = dp->i_offset & bmask) && |
| 230 | (error = ffs_blkatoff(vdp, (off_t)dp->i_offset, NULL, &bp))) |
| 231 | return (error); |
| 232 | numdirpasses = 2; |
| 233 | gd->gd_nchstats->ncs_2passes++; |
| 234 | } |
| 235 | prevoff = dp->i_offset; |
| 236 | endsearch = roundup2(dp->i_size, DIRBLKSIZ); |
| 237 | enduseful = 0; |
| 238 | |
| 239 | searchloop: |
| 240 | while (dp->i_offset < endsearch) { |
| 241 | /* |
| 242 | * If necessary, get the next directory block. |
| 243 | */ |
| 244 | if ((dp->i_offset & bmask) == 0) { |
| 245 | if (bp != NULL) |
| 246 | brelse(bp); |
| 247 | error = |
| 248 | ffs_blkatoff(vdp, (off_t)dp->i_offset, NULL, &bp); |
| 249 | if (error) |
| 250 | return (error); |
| 251 | entryoffsetinblock = 0; |
| 252 | } |
| 253 | /* |
| 254 | * If still looking for a slot, and at a DIRBLKSIZE |
| 255 | * boundary, have to start looking for free space again. |
| 256 | */ |
| 257 | if (slotstatus == NONE && |
| 258 | (entryoffsetinblock & (DIRBLKSIZ - 1)) == 0) { |
| 259 | slotoffset = -1; |
| 260 | slotfreespace = 0; |
| 261 | } |
| 262 | /* |
| 263 | * Get pointer to next entry. |
| 264 | * Full validation checks are slow, so we only check |
| 265 | * enough to insure forward progress through the |
| 266 | * directory. Complete checks can be run by patching |
| 267 | * "dirchk" to be true. |
| 268 | */ |
| 269 | ep = (struct direct *)((char *)bp->b_data + entryoffsetinblock); |
| 270 | if (ep->d_reclen == 0 || ep->d_reclen > |
| 271 | DIRBLKSIZ - (entryoffsetinblock & (DIRBLKSIZ - 1)) || |
| 272 | (dirchk && ufs_dirbadentry(vdp, ep, entryoffsetinblock))) { |
| 273 | int i; |
| 274 | |
| 275 | ufs_dirbad(dp, dp->i_offset, "mangled entry"); |
| 276 | i = DIRBLKSIZ - (entryoffsetinblock & (DIRBLKSIZ - 1)); |
| 277 | dp->i_offset += i; |
| 278 | entryoffsetinblock += i; |
| 279 | continue; |
| 280 | } |
| 281 | |
| 282 | /* |
| 283 | * If an appropriate sized slot has not yet been found, |
| 284 | * check to see if one is available. Also accumulate space |
| 285 | * in the current block so that we can determine if |
| 286 | * compaction is viable. |
| 287 | */ |
| 288 | if (slotstatus != FOUND) { |
| 289 | int size = ep->d_reclen; |
| 290 | |
| 291 | if (ep->d_ino != 0) |
| 292 | size -= DIRSIZ(OFSFMT(vdp), ep); |
| 293 | if (size > 0) { |
| 294 | if (size >= slotneeded) { |
| 295 | slotstatus = FOUND; |
| 296 | slotoffset = dp->i_offset; |
| 297 | slotsize = ep->d_reclen; |
| 298 | } else if (slotstatus == NONE) { |
| 299 | slotfreespace += size; |
| 300 | if (slotoffset == -1) |
| 301 | slotoffset = dp->i_offset; |
| 302 | if (slotfreespace >= slotneeded) { |
| 303 | slotstatus = COMPACT; |
| 304 | slotsize = dp->i_offset + |
| 305 | ep->d_reclen - slotoffset; |
| 306 | } |
| 307 | } |
| 308 | } |
| 309 | } |
| 310 | |
| 311 | /* |
| 312 | * Check for a name match. |
| 313 | */ |
| 314 | if (ep->d_ino) { |
| 315 | # if (BYTE_ORDER == LITTLE_ENDIAN) |
| 316 | if (OFSFMT(vdp)) |
| 317 | namlen = ep->d_type; |
| 318 | else |
| 319 | namlen = ep->d_namlen; |
| 320 | # else |
| 321 | namlen = ep->d_namlen; |
| 322 | # endif |
| 323 | if (namlen == cnp->cn_namelen && |
| 324 | (cnp->cn_nameptr[0] == ep->d_name[0]) && |
| 325 | !bcmp(cnp->cn_nameptr, ep->d_name, |
| 326 | (unsigned)namlen)) { |
| 327 | #ifdef UFS_DIRHASH |
| 328 | foundentry: |
| 329 | #endif |
| 330 | /* |
| 331 | * Save directory entry's inode number and |
| 332 | * reclen in ndp->ni_ufs area, and release |
| 333 | * directory buffer. |
| 334 | */ |
| 335 | if (vdp->v_mount->mnt_maxsymlinklen > 0 && |
| 336 | ep->d_type == DT_WHT) { |
| 337 | slotstatus = FOUND; |
| 338 | slotoffset = dp->i_offset; |
| 339 | slotsize = ep->d_reclen; |
| 340 | dp->i_reclen = slotsize; |
| 341 | enduseful = dp->i_size; |
| 342 | ap->a_cnp->cn_flags |= CNP_ISWHITEOUT; |
| 343 | numdirpasses--; |
| 344 | goto notfound; |
| 345 | } |
| 346 | dp->i_ino = ep->d_ino; |
| 347 | dp->i_reclen = ep->d_reclen; |
| 348 | goto found; |
| 349 | } |
| 350 | } |
| 351 | prevoff = dp->i_offset; |
| 352 | dp->i_offset += ep->d_reclen; |
| 353 | entryoffsetinblock += ep->d_reclen; |
| 354 | if (ep->d_ino) |
| 355 | enduseful = dp->i_offset; |
| 356 | } |
| 357 | notfound: |
| 358 | /* |
| 359 | * If we started in the middle of the directory and failed |
| 360 | * to find our target, we must check the beginning as well. |
| 361 | */ |
| 362 | if (numdirpasses == 2) { |
| 363 | numdirpasses--; |
| 364 | dp->i_offset = 0; |
| 365 | endsearch = dp->i_diroff; |
| 366 | goto searchloop; |
| 367 | } |
| 368 | if (bp != NULL) |
| 369 | brelse(bp); |
| 370 | /* |
| 371 | * If creating, and at end of pathname and current |
| 372 | * directory has not been removed, then can consider |
| 373 | * allowing file to be created. |
| 374 | */ |
| 375 | if ((nameiop == NAMEI_CREATE || nameiop == NAMEI_RENAME || |
| 376 | (nameiop == NAMEI_DELETE && |
| 377 | (ap->a_cnp->cn_flags & CNP_DOWHITEOUT) && |
| 378 | (ap->a_cnp->cn_flags & CNP_ISWHITEOUT))) && |
| 379 | dp->i_effnlink != 0) { |
| 380 | /* |
| 381 | * Access for write is interpreted as allowing |
| 382 | * creation of files in the directory. |
| 383 | */ |
| 384 | error = VOP_ACCESS(vdp, VWRITE, cred); |
| 385 | if (error) |
| 386 | return (error); |
| 387 | /* |
| 388 | * Return an indication of where the new directory |
| 389 | * entry should be put. If we didn't find a slot, |
| 390 | * then set dp->i_count to 0 indicating |
| 391 | * that the new slot belongs at the end of the |
| 392 | * directory. If we found a slot, then the new entry |
| 393 | * can be put in the range from dp->i_offset to |
| 394 | * dp->i_offset + dp->i_count. |
| 395 | */ |
| 396 | if (slotstatus == NONE) { |
| 397 | dp->i_offset = roundup2(dp->i_size, DIRBLKSIZ); |
| 398 | dp->i_count = 0; |
| 399 | enduseful = dp->i_offset; |
| 400 | } else if (nameiop == NAMEI_DELETE) { |
| 401 | dp->i_offset = slotoffset; |
| 402 | if ((dp->i_offset & (DIRBLKSIZ - 1)) == 0) |
| 403 | dp->i_count = 0; |
| 404 | else |
| 405 | dp->i_count = dp->i_offset - prevoff; |
| 406 | } else { |
| 407 | dp->i_offset = slotoffset; |
| 408 | dp->i_count = slotsize; |
| 409 | if (enduseful < slotoffset + slotsize) |
| 410 | enduseful = slotoffset + slotsize; |
| 411 | } |
| 412 | dp->i_endoff = roundup2(enduseful, DIRBLKSIZ); |
| 413 | dp->i_flag |= IN_CHANGE | IN_UPDATE; |
| 414 | /* |
| 415 | * We return with the directory locked, so that |
| 416 | * the parameters we set up above will still be |
| 417 | * valid if we actually decide to do a direnter(). |
| 418 | * We return ni_vp == NULL to indicate that the entry |
| 419 | * does not currently exist; we leave a pointer to |
| 420 | * the (locked) directory inode in ndp->ni_dvp. |
| 421 | * The pathname buffer is saved so that the name |
| 422 | * can be obtained later. |
| 423 | * |
| 424 | * NB - if the directory is unlocked, then this |
| 425 | * information cannot be used. |
| 426 | */ |
| 427 | if (!lockparent) { |
| 428 | vn_unlock(vdp); |
| 429 | cnp->cn_flags |= CNP_PDIRUNLOCK; |
| 430 | } |
| 431 | return (EJUSTRETURN); |
| 432 | } |
| 433 | return (ENOENT); |
| 434 | |
| 435 | found: |
| 436 | if (numdirpasses == 2) |
| 437 | gd->gd_nchstats->ncs_pass2++; |
| 438 | /* |
| 439 | * Check that directory length properly reflects presence |
| 440 | * of this entry. |
| 441 | */ |
| 442 | if (dp->i_offset + DIRSIZ(OFSFMT(vdp), ep) > dp->i_size) { |
| 443 | ufs_dirbad(dp, dp->i_offset, "i_size too small"); |
| 444 | dp->i_size = dp->i_offset + DIRSIZ(OFSFMT(vdp), ep); |
| 445 | dp->i_flag |= IN_CHANGE | IN_UPDATE; |
| 446 | } |
| 447 | brelse(bp); |
| 448 | |
| 449 | /* |
| 450 | * Found component in pathname. |
| 451 | * If the final component of path name, save information |
| 452 | * in the cache as to where the entry was found. |
| 453 | */ |
| 454 | if (nameiop == NAMEI_LOOKUP) |
| 455 | dp->i_diroff = dp->i_offset &~ (DIRBLKSIZ - 1); |
| 456 | |
| 457 | /* |
| 458 | * If deleting, and at end of pathname, return |
| 459 | * parameters which can be used to remove file. |
| 460 | * If the wantparent flag isn't set, we return only |
| 461 | * the directory (in ndp->ni_dvp), otherwise we go |
| 462 | * on and lock the inode, being careful with ".". |
| 463 | */ |
| 464 | if (nameiop == NAMEI_DELETE) { |
| 465 | /* |
| 466 | * Write access to directory required to delete files. |
| 467 | */ |
| 468 | error = VOP_ACCESS(vdp, VWRITE, cred); |
| 469 | if (error) |
| 470 | return (error); |
| 471 | /* |
| 472 | * Return pointer to current entry in dp->i_offset, |
| 473 | * and distance past previous entry (if there |
| 474 | * is a previous entry in this block) in dp->i_count. |
| 475 | * Save directory inode pointer in ndp->ni_dvp for dirremove(). |
| 476 | */ |
| 477 | if ((dp->i_offset & (DIRBLKSIZ - 1)) == 0) |
| 478 | dp->i_count = 0; |
| 479 | else |
| 480 | dp->i_count = dp->i_offset - prevoff; |
| 481 | if (dp->i_number == dp->i_ino) { |
| 482 | vref(vdp); |
| 483 | *vpp = vdp; |
| 484 | return (0); |
| 485 | } |
| 486 | if (flags & CNP_ISDOTDOT) |
| 487 | vn_unlock(vdp); /* race to get the inode */ |
| 488 | error = VFS_VGET(vdp->v_mount, dp->i_ino, &tdp); |
| 489 | if (flags & CNP_ISDOTDOT) { |
| 490 | if (vn_lock(vdp, LK_EXCLUSIVE | LK_RETRY) != 0) |
| 491 | cnp->cn_flags |= CNP_PDIRUNLOCK; |
| 492 | } |
| 493 | if (error) |
| 494 | return (error); |
| 495 | /* |
| 496 | * If directory is "sticky", then user must own |
| 497 | * the directory, or the file in it, else she |
| 498 | * may not delete it (unless she's root). This |
| 499 | * implements append-only directories. |
| 500 | */ |
| 501 | if ((dp->i_mode & ISVTX) && |
| 502 | cred->cr_uid != 0 && |
| 503 | cred->cr_uid != dp->i_uid && |
| 504 | VTOI(tdp)->i_uid != cred->cr_uid) { |
| 505 | vput(tdp); |
| 506 | return (EPERM); |
| 507 | } |
| 508 | *vpp = tdp; |
| 509 | if (!lockparent) { |
| 510 | vn_unlock(vdp); |
| 511 | cnp->cn_flags |= CNP_PDIRUNLOCK; |
| 512 | } |
| 513 | return (0); |
| 514 | } |
| 515 | |
| 516 | /* |
| 517 | * If rewriting (RENAME), return the inode and the |
| 518 | * information required to rewrite the present directory |
| 519 | * Must get inode of directory entry to verify it's a |
| 520 | * regular file, or empty directory. |
| 521 | */ |
| 522 | if (nameiop == NAMEI_RENAME && wantparent) { |
| 523 | if ((error = VOP_ACCESS(vdp, VWRITE, cred)) != 0) |
| 524 | return (error); |
| 525 | /* |
| 526 | * Careful about locking second inode. |
| 527 | * This can only occur if the target is ".". |
| 528 | */ |
| 529 | if (dp->i_number == dp->i_ino) |
| 530 | return (EISDIR); |
| 531 | if (flags & CNP_ISDOTDOT) |
| 532 | vn_unlock(vdp); /* race to get the inode */ |
| 533 | error = VFS_VGET(vdp->v_mount, dp->i_ino, &tdp); |
| 534 | if (flags & CNP_ISDOTDOT) { |
| 535 | if (vn_lock(vdp, LK_EXCLUSIVE | LK_RETRY) != 0) |
| 536 | cnp->cn_flags |= CNP_PDIRUNLOCK; |
| 537 | } |
| 538 | if (error) |
| 539 | return (error); |
| 540 | *vpp = tdp; |
| 541 | if (!lockparent) { |
| 542 | vn_unlock(vdp); |
| 543 | cnp->cn_flags |= CNP_PDIRUNLOCK; |
| 544 | } |
| 545 | return (0); |
| 546 | } |
| 547 | |
| 548 | /* |
| 549 | * Step through the translation in the name. We do not `vput' the |
| 550 | * directory because we may need it again if a symbolic link |
| 551 | * is relative to the current directory. Instead we save it |
| 552 | * unlocked as "pdp". We must get the target inode before unlocking |
| 553 | * the directory to insure that the inode will not be removed |
| 554 | * before we get it. We prevent deadlock by always fetching |
| 555 | * inodes from the root, moving down the directory tree. Thus |
| 556 | * when following backward pointers ".." we must unlock the |
| 557 | * parent directory before getting the requested directory. |
| 558 | * There is a potential race condition here if both the current |
| 559 | * and parent directories are removed before the VFS_VGET for the |
| 560 | * inode associated with ".." returns. We hope that this occurs |
| 561 | * infrequently since we cannot avoid this race condition without |
| 562 | * implementing a sophisticated deadlock detection algorithm. |
| 563 | * Note also that this simple deadlock detection scheme will not |
| 564 | * work if the filesystem has any hard links other than ".." |
| 565 | * that point backwards in the directory structure. |
| 566 | */ |
| 567 | pdp = vdp; |
| 568 | if (flags & CNP_ISDOTDOT) { |
| 569 | vn_unlock(pdp); /* race to get the inode */ |
| 570 | cnp->cn_flags |= CNP_PDIRUNLOCK; |
| 571 | if ((error = VFS_VGET(vdp->v_mount, dp->i_ino, &tdp)) != 0) { |
| 572 | if (vn_lock(pdp, LK_EXCLUSIVE | LK_RETRY) == 0) |
| 573 | cnp->cn_flags &= ~CNP_PDIRUNLOCK; |
| 574 | return (error); |
| 575 | } |
| 576 | if (lockparent) { |
| 577 | if ((error = vn_lock(pdp, LK_EXCLUSIVE)) != 0) { |
| 578 | vput(tdp); |
| 579 | return (error); |
| 580 | } |
| 581 | cnp->cn_flags &= ~CNP_PDIRUNLOCK; |
| 582 | } |
| 583 | *vpp = tdp; |
| 584 | } else if (dp->i_number == dp->i_ino) { |
| 585 | vref(vdp); /* we want ourself, ie "." */ |
| 586 | *vpp = vdp; |
| 587 | } else { |
| 588 | error = VFS_VGET(vdp->v_mount, dp->i_ino, &tdp); |
| 589 | if (error) |
| 590 | return (error); |
| 591 | if (!lockparent) { |
| 592 | vn_unlock(pdp); |
| 593 | cnp->cn_flags |= CNP_PDIRUNLOCK; |
| 594 | } |
| 595 | *vpp = tdp; |
| 596 | } |
| 597 | return (0); |
| 598 | } |
| 599 | |
| 600 | void |
| 601 | ufs_dirbad(struct inode *ip, doff_t offset, char *how) |
| 602 | { |
| 603 | struct mount *mp; |
| 604 | |
| 605 | mp = ITOV(ip)->v_mount; |
| 606 | (void)kprintf("%s: bad dir ino %lu at offset %ld: %s\n", |
| 607 | mp->mnt_stat.f_mntfromname, (u_long)ip->i_number, (long)offset, how); |
| 608 | if ((mp->mnt_flag & MNT_RDONLY) == 0) |
| 609 | panic("ufs_dirbad: bad dir"); |
| 610 | } |
| 611 | |
| 612 | /* |
| 613 | * Do consistency checking on a directory entry: |
| 614 | * record length must be multiple of 4 |
| 615 | * entry must fit in rest of its DIRBLKSIZ block |
| 616 | * record must be large enough to contain entry |
| 617 | * name is not longer than MAXNAMLEN |
| 618 | * name must be as long as advertised, and null terminated |
| 619 | */ |
| 620 | int |
| 621 | ufs_dirbadentry(struct vnode *dp, struct direct *ep, int entryoffsetinblock) |
| 622 | { |
| 623 | int i; |
| 624 | int namlen; |
| 625 | |
| 626 | # if (BYTE_ORDER == LITTLE_ENDIAN) |
| 627 | if (OFSFMT(dp)) |
| 628 | namlen = ep->d_type; |
| 629 | else |
| 630 | namlen = ep->d_namlen; |
| 631 | # else |
| 632 | namlen = ep->d_namlen; |
| 633 | # endif |
| 634 | if ((ep->d_reclen & 0x3) != 0 || |
| 635 | ep->d_reclen > DIRBLKSIZ - (entryoffsetinblock & (DIRBLKSIZ - 1)) || |
| 636 | ep->d_reclen < DIRSIZ(OFSFMT(dp), ep) || namlen > MAXNAMLEN) { |
| 637 | /*return (1); */ |
| 638 | kprintf("First bad\n"); |
| 639 | goto bad; |
| 640 | } |
| 641 | if (ep->d_ino == 0) |
| 642 | return (0); |
| 643 | for (i = 0; i < namlen; i++) |
| 644 | if (ep->d_name[i] == '\0') { |
| 645 | /*return (1); */ |
| 646 | kprintf("Second bad\n"); |
| 647 | goto bad; |
| 648 | } |
| 649 | if (ep->d_name[i]) |
| 650 | goto bad; |
| 651 | return (0); |
| 652 | bad: |
| 653 | return (1); |
| 654 | } |
| 655 | |
| 656 | /* |
| 657 | * Construct a new directory entry after a call to namei, using the |
| 658 | * parameters that it left in the componentname argument cnp. The |
| 659 | * argument ip is the inode to which the new directory entry will refer. |
| 660 | */ |
| 661 | void |
| 662 | ufs_makedirentry(struct inode *ip, struct componentname *cnp, |
| 663 | struct direct *newdirp) |
| 664 | { |
| 665 | |
| 666 | newdirp->d_ino = ip->i_number; |
| 667 | newdirp->d_namlen = cnp->cn_namelen; |
| 668 | bcopy(cnp->cn_nameptr, newdirp->d_name, (unsigned)cnp->cn_namelen + 1); |
| 669 | if (ITOV(ip)->v_mount->mnt_maxsymlinklen > 0) |
| 670 | newdirp->d_type = IFTODT(ip->i_mode); |
| 671 | else { |
| 672 | newdirp->d_type = 0; |
| 673 | # if (BYTE_ORDER == LITTLE_ENDIAN) |
| 674 | { u_char tmp = newdirp->d_namlen; |
| 675 | newdirp->d_namlen = newdirp->d_type; |
| 676 | newdirp->d_type = tmp; } |
| 677 | # endif |
| 678 | } |
| 679 | } |
| 680 | |
| 681 | /* |
| 682 | * Write a directory entry after a call to namei, using the parameters |
| 683 | * that it left in the directory inode. The argument dirp is the new directory |
| 684 | * entry contents. Dvp is a pointer to the directory to be written, |
| 685 | * which was left locked by namei. Remaining parameters (dp->i_offset, |
| 686 | * dp->i_count) indicate how the space for the new entry is to be obtained. |
| 687 | * Non-null bp indicates that a directory is being created (for the |
| 688 | * soft dependency code). |
| 689 | */ |
| 690 | int |
| 691 | ufs_direnter(struct vnode *dvp, struct vnode *tvp, struct direct *dirp, |
| 692 | struct componentname *cnp, struct buf *newdirbp) |
| 693 | { |
| 694 | struct ucred *cred; |
| 695 | struct thread *td = curthread; /* XXX */ |
| 696 | int newentrysize; |
| 697 | struct inode *dp; |
| 698 | struct buf *bp; |
| 699 | uint dsize; |
| 700 | struct direct *ep, *nep; |
| 701 | int error, ret, blkoff, loc, spacefree, flags; |
| 702 | char *dirbuf; |
| 703 | |
| 704 | KKASSERT(td->td_proc); /* YYY use/require cred passed in cnp? */ |
| 705 | cred = td->td_proc->p_ucred; |
| 706 | |
| 707 | dp = VTOI(dvp); |
| 708 | newentrysize = DIRSIZ(OFSFMT(dvp), dirp); |
| 709 | |
| 710 | if (dp->i_count == 0) { |
| 711 | /* |
| 712 | * If dp->i_count is 0, then namei could find no |
| 713 | * space in the directory. Here, dp->i_offset will |
| 714 | * be on a directory block boundary and we will write the |
| 715 | * new entry into a fresh block. |
| 716 | */ |
| 717 | if (dp->i_offset & (DIRBLKSIZ - 1)) |
| 718 | panic("ufs_direnter: newblk"); |
| 719 | vnode_pager_setsize(dvp, dp->i_offset + DIRBLKSIZ); |
| 720 | flags = B_CLRBUF; |
| 721 | if (!DOINGSOFTDEP(dvp) && !DOINGASYNC(dvp)) |
| 722 | flags |= B_SYNC; |
| 723 | if ((error = VOP_BALLOC(dvp, (off_t)dp->i_offset, DIRBLKSIZ, |
| 724 | cred, flags, &bp)) != 0) { |
| 725 | if (DOINGSOFTDEP(dvp) && newdirbp != NULL) |
| 726 | bdwrite(newdirbp); |
| 727 | return (error); |
| 728 | } |
| 729 | dp->i_size = dp->i_offset + DIRBLKSIZ; |
| 730 | dp->i_flag |= IN_CHANGE | IN_UPDATE; |
| 731 | dirp->d_reclen = DIRBLKSIZ; |
| 732 | blkoff = dp->i_offset & |
| 733 | (VFSTOUFS(dvp->v_mount)->um_mountp->mnt_stat.f_iosize - 1); |
| 734 | bcopy((caddr_t)dirp, (caddr_t)bp->b_data + blkoff,newentrysize); |
| 735 | #ifdef UFS_DIRHASH |
| 736 | if (dp->i_dirhash != NULL) { |
| 737 | ufsdirhash_newblk(dp, dp->i_offset); |
| 738 | ufsdirhash_add(dp, dirp, dp->i_offset); |
| 739 | ufsdirhash_checkblock(dp, (char *)bp->b_data + blkoff, |
| 740 | dp->i_offset); |
| 741 | } |
| 742 | #endif |
| 743 | if (DOINGSOFTDEP(dvp)) { |
| 744 | /* |
| 745 | * Ensure that the entire newly allocated block is a |
| 746 | * valid directory so that future growth within the |
| 747 | * block does not have to ensure that the block is |
| 748 | * written before the inode. |
| 749 | */ |
| 750 | blkoff += DIRBLKSIZ; |
| 751 | while (blkoff < bp->b_bcount) { |
| 752 | ((struct direct *) |
| 753 | (bp->b_data + blkoff))->d_reclen = DIRBLKSIZ; |
| 754 | blkoff += DIRBLKSIZ; |
| 755 | } |
| 756 | softdep_setup_directory_add(bp, dp, dp->i_offset, |
| 757 | dirp->d_ino, newdirbp); |
| 758 | bdwrite(bp); |
| 759 | return (ffs_update(dvp, 0)); |
| 760 | } |
| 761 | if (DOINGASYNC(dvp)) { |
| 762 | bdwrite(bp); |
| 763 | return (ffs_update(dvp, 0)); |
| 764 | } |
| 765 | error = bwrite(bp); |
| 766 | ret = ffs_update(dvp, 1); |
| 767 | if (error == 0) |
| 768 | return (ret); |
| 769 | return (error); |
| 770 | } |
| 771 | |
| 772 | /* |
| 773 | * If dp->i_count is non-zero, then namei found space for the new |
| 774 | * entry in the range dp->i_offset to dp->i_offset + dp->i_count |
| 775 | * in the directory. To use this space, we may have to compact |
| 776 | * the entries located there, by copying them together towards the |
| 777 | * beginning of the block, leaving the free space in one usable |
| 778 | * chunk at the end. |
| 779 | */ |
| 780 | |
| 781 | /* |
| 782 | * Increase size of directory if entry eats into new space. |
| 783 | * This should never push the size past a new multiple of |
| 784 | * DIRBLKSIZE. |
| 785 | * |
| 786 | * N.B. - THIS IS AN ARTIFACT OF 4.2 AND SHOULD NEVER HAPPEN. |
| 787 | */ |
| 788 | if (dp->i_offset + dp->i_count > dp->i_size) |
| 789 | dp->i_size = dp->i_offset + dp->i_count; |
| 790 | /* |
| 791 | * Get the block containing the space for the new directory entry. |
| 792 | */ |
| 793 | error = ffs_blkatoff(dvp, (off_t)dp->i_offset, &dirbuf, &bp); |
| 794 | if (error) { |
| 795 | if (DOINGSOFTDEP(dvp) && newdirbp != NULL) |
| 796 | bdwrite(newdirbp); |
| 797 | return (error); |
| 798 | } |
| 799 | /* |
| 800 | * Find space for the new entry. In the simple case, the entry at |
| 801 | * offset base will have the space. If it does not, then namei |
| 802 | * arranged that compacting the region dp->i_offset to |
| 803 | * dp->i_offset + dp->i_count would yield the space. |
| 804 | */ |
| 805 | ep = (struct direct *)dirbuf; |
| 806 | dsize = ep->d_ino ? DIRSIZ(OFSFMT(dvp), ep) : 0; |
| 807 | spacefree = ep->d_reclen - dsize; |
| 808 | for (loc = ep->d_reclen; loc < dp->i_count; ) { |
| 809 | nep = (struct direct *)(dirbuf + loc); |
| 810 | |
| 811 | /* Trim the existing slot (NB: dsize may be zero). */ |
| 812 | ep->d_reclen = dsize; |
| 813 | ep = (struct direct *)((char *)ep + dsize); |
| 814 | |
| 815 | /* Read nep->d_reclen now as the bcopy() may clobber it. */ |
| 816 | loc += nep->d_reclen; |
| 817 | if (nep->d_ino == 0) { |
| 818 | /* |
| 819 | * A mid-block unused entry. Such entries are |
| 820 | * never created by the kernel, but fsck_ffs |
| 821 | * can create them (and it doesn't fix them). |
| 822 | * |
| 823 | * Add up the free space, and initialise the |
| 824 | * relocated entry since we don't bcopy it. |
| 825 | */ |
| 826 | spacefree += nep->d_reclen; |
| 827 | ep->d_ino = 0; |
| 828 | dsize = 0; |
| 829 | continue; |
| 830 | } |
| 831 | dsize = DIRSIZ(OFSFMT(dvp), nep); |
| 832 | spacefree += nep->d_reclen - dsize; |
| 833 | #ifdef UFS_DIRHASH |
| 834 | if (dp->i_dirhash != NULL) |
| 835 | ufsdirhash_move(dp, nep, |
| 836 | dp->i_offset + ((char *)nep - dirbuf), |
| 837 | dp->i_offset + ((char *)ep - dirbuf)); |
| 838 | #endif |
| 839 | if (DOINGSOFTDEP(dvp)) |
| 840 | softdep_change_directoryentry_offset(dp, dirbuf, |
| 841 | (caddr_t)nep, (caddr_t)ep, dsize); |
| 842 | else |
| 843 | bcopy((caddr_t)nep, (caddr_t)ep, dsize); |
| 844 | } |
| 845 | /* |
| 846 | * Here, `ep' points to a directory entry containing `dsize' in-use |
| 847 | * bytes followed by `spacefree' unused bytes. If ep->d_ino == 0, |
| 848 | * then the entry is completely unused (dsize == 0). The value |
| 849 | * of ep->d_reclen is always indeterminate. |
| 850 | * |
| 851 | * Update the pointer fields in the previous entry (if any), |
| 852 | * copy in the new entry, and write out the block. |
| 853 | */ |
| 854 | if (ep->d_ino == 0 || |
| 855 | (ep->d_ino == WINO && |
| 856 | bcmp(ep->d_name, dirp->d_name, dirp->d_namlen) == 0)) { |
| 857 | if (spacefree + dsize < newentrysize) |
| 858 | panic("ufs_direnter: compact1"); |
| 859 | dirp->d_reclen = spacefree + dsize; |
| 860 | } else { |
| 861 | if (spacefree < newentrysize) |
| 862 | panic("ufs_direnter: compact2"); |
| 863 | dirp->d_reclen = spacefree; |
| 864 | ep->d_reclen = dsize; |
| 865 | ep = (struct direct *)((char *)ep + dsize); |
| 866 | } |
| 867 | #ifdef UFS_DIRHASH |
| 868 | if (dp->i_dirhash != NULL && (ep->d_ino == 0 || |
| 869 | dirp->d_reclen == spacefree)) |
| 870 | ufsdirhash_add(dp, dirp, dp->i_offset + ((char *)ep - dirbuf)); |
| 871 | #endif |
| 872 | bcopy((caddr_t)dirp, (caddr_t)ep, (uint)newentrysize); |
| 873 | #ifdef UFS_DIRHASH |
| 874 | if (dp->i_dirhash != NULL) |
| 875 | ufsdirhash_checkblock(dp, dirbuf - |
| 876 | (dp->i_offset & (DIRBLKSIZ - 1)), |
| 877 | dp->i_offset & ~(DIRBLKSIZ - 1)); |
| 878 | #endif |
| 879 | |
| 880 | if (DOINGSOFTDEP(dvp)) { |
| 881 | softdep_setup_directory_add(bp, dp, |
| 882 | dp->i_offset + (caddr_t)ep - dirbuf, dirp->d_ino, newdirbp); |
| 883 | bdwrite(bp); |
| 884 | } else { |
| 885 | if (DOINGASYNC(dvp)) { |
| 886 | bdwrite(bp); |
| 887 | error = 0; |
| 888 | } else { |
| 889 | error = bowrite(bp); |
| 890 | } |
| 891 | } |
| 892 | dp->i_flag |= IN_CHANGE | IN_UPDATE; |
| 893 | /* |
| 894 | * If all went well, and the directory can be shortened, proceed |
| 895 | * with the truncation. Note that we have to unlock the inode for |
| 896 | * the entry that we just entered, as the truncation may need to |
| 897 | * lock other inodes which can lead to deadlock if we also hold a |
| 898 | * lock on the newly entered node. |
| 899 | */ |
| 900 | if (error == 0 && dp->i_endoff && dp->i_endoff < dp->i_size) { |
| 901 | if (tvp != NULL) |
| 902 | vn_unlock(tvp); |
| 903 | #ifdef UFS_DIRHASH |
| 904 | if (dp->i_dirhash != NULL) |
| 905 | ufsdirhash_dirtrunc(dp, dp->i_endoff); |
| 906 | #endif |
| 907 | (void)ffs_truncate(dvp, (off_t)dp->i_endoff, IO_SYNC, cred); |
| 908 | if (tvp != NULL) |
| 909 | vn_lock(tvp, LK_EXCLUSIVE | LK_RETRY); |
| 910 | } |
| 911 | return (error); |
| 912 | } |
| 913 | |
| 914 | /* |
| 915 | * Remove a directory entry after a call to namei, using |
| 916 | * the parameters which it left in the directory inode. The entry |
| 917 | * dp->i_offset contains the offset into the directory of the |
| 918 | * entry to be eliminated. The dp->i_count field contains the |
| 919 | * size of the previous record in the directory. If this |
| 920 | * is 0, the first entry is being deleted, so we need only |
| 921 | * zero the inode number to mark the entry as free. If the |
| 922 | * entry is not the first in the directory, we must reclaim |
| 923 | * the space of the now empty record by adding the record size |
| 924 | * to the size of the previous entry. |
| 925 | */ |
| 926 | int |
| 927 | ufs_dirremove(struct vnode *dvp, struct inode *ip, int flags, int isrmdir) |
| 928 | { |
| 929 | struct inode *dp; |
| 930 | struct direct *ep; |
| 931 | struct buf *bp; |
| 932 | int error; |
| 933 | |
| 934 | dp = VTOI(dvp); |
| 935 | |
| 936 | if (flags & CNP_DOWHITEOUT) { |
| 937 | /* |
| 938 | * Whiteout entry: set d_ino to WINO. |
| 939 | */ |
| 940 | if ((error = |
| 941 | ffs_blkatoff(dvp, (off_t)dp->i_offset, (char **)&ep, &bp)) != 0) |
| 942 | return (error); |
| 943 | ep->d_ino = WINO; |
| 944 | ep->d_type = DT_WHT; |
| 945 | goto out; |
| 946 | } |
| 947 | |
| 948 | if ((error = ffs_blkatoff(dvp, |
| 949 | (off_t)(dp->i_offset - dp->i_count), (char **)&ep, &bp)) != 0) |
| 950 | return (error); |
| 951 | #ifdef UFS_DIRHASH |
| 952 | /* |
| 953 | * Remove the dirhash entry. This is complicated by the fact |
| 954 | * that `ep' is the previous entry when dp->i_count != 0. |
| 955 | */ |
| 956 | if (dp->i_dirhash != NULL) |
| 957 | ufsdirhash_remove(dp, (dp->i_count == 0) ? ep : |
| 958 | (struct direct *)((char *)ep + ep->d_reclen), dp->i_offset); |
| 959 | #endif |
| 960 | if (dp->i_count == 0) { |
| 961 | /* |
| 962 | * First entry in block: set d_ino to zero. |
| 963 | */ |
| 964 | ep->d_ino = 0; |
| 965 | } else { |
| 966 | /* |
| 967 | * Collapse new free space into previous entry. |
| 968 | */ |
| 969 | ep->d_reclen += dp->i_reclen; |
| 970 | } |
| 971 | #ifdef UFS_DIRHASH |
| 972 | if (dp->i_dirhash != NULL) |
| 973 | ufsdirhash_checkblock(dp, (char *)ep - |
| 974 | ((dp->i_offset - dp->i_count) & (DIRBLKSIZ - 1)), |
| 975 | dp->i_offset & ~(DIRBLKSIZ - 1)); |
| 976 | #endif |
| 977 | out: |
| 978 | if (DOINGSOFTDEP(dvp)) { |
| 979 | if (ip) { |
| 980 | ip->i_effnlink--; |
| 981 | softdep_change_linkcnt(ip); |
| 982 | softdep_setup_remove(bp, dp, ip, isrmdir); |
| 983 | } |
| 984 | if (softdep_slowdown(dvp)) { |
| 985 | error = bwrite(bp); |
| 986 | } else { |
| 987 | bdwrite(bp); |
| 988 | error = 0; |
| 989 | } |
| 990 | } else { |
| 991 | if (ip) { |
| 992 | ip->i_effnlink--; |
| 993 | ip->i_nlink--; |
| 994 | ip->i_flag |= IN_CHANGE; |
| 995 | } |
| 996 | if (flags & CNP_DOWHITEOUT) |
| 997 | error = bwrite(bp); |
| 998 | else if (DOINGASYNC(dvp) && dp->i_count != 0) { |
| 999 | bdwrite(bp); |
| 1000 | error = 0; |
| 1001 | } else |
| 1002 | error = bowrite(bp); |
| 1003 | } |
| 1004 | dp->i_flag |= IN_CHANGE | IN_UPDATE; |
| 1005 | return (error); |
| 1006 | } |
| 1007 | |
| 1008 | /* |
| 1009 | * Rewrite an existing directory entry to point at the inode |
| 1010 | * supplied. The parameters describing the directory entry are |
| 1011 | * set up by a call to namei. |
| 1012 | */ |
| 1013 | int |
| 1014 | ufs_dirrewrite(struct inode *dp, struct inode *oip, ino_t newinum, int newtype, |
| 1015 | int isrmdir) |
| 1016 | { |
| 1017 | struct buf *bp; |
| 1018 | struct direct *ep; |
| 1019 | struct vnode *vdp = ITOV(dp); |
| 1020 | int error; |
| 1021 | |
| 1022 | error = ffs_blkatoff(vdp, (off_t)dp->i_offset, (char **)&ep, &bp); |
| 1023 | if (error) |
| 1024 | return (error); |
| 1025 | ep->d_ino = newinum; |
| 1026 | if (!OFSFMT(vdp)) |
| 1027 | ep->d_type = newtype; |
| 1028 | oip->i_effnlink--; |
| 1029 | if (DOINGSOFTDEP(vdp)) { |
| 1030 | softdep_change_linkcnt(oip); |
| 1031 | softdep_setup_directory_change(bp, dp, oip, newinum, isrmdir); |
| 1032 | bdwrite(bp); |
| 1033 | } else { |
| 1034 | oip->i_nlink--; |
| 1035 | oip->i_flag |= IN_CHANGE; |
| 1036 | if (DOINGASYNC(vdp)) { |
| 1037 | bdwrite(bp); |
| 1038 | error = 0; |
| 1039 | } else { |
| 1040 | error = bowrite(bp); |
| 1041 | } |
| 1042 | } |
| 1043 | dp->i_flag |= IN_CHANGE | IN_UPDATE; |
| 1044 | return (error); |
| 1045 | } |
| 1046 | |
| 1047 | /* |
| 1048 | * Check if a directory is empty or not. |
| 1049 | * Inode supplied must be locked. |
| 1050 | * |
| 1051 | * Using a struct dirtemplate here is not precisely |
| 1052 | * what we want, but better than using a struct direct. |
| 1053 | * |
| 1054 | * NB: does not handle corrupted directories. |
| 1055 | */ |
| 1056 | int |
| 1057 | ufs_dirempty(struct inode *ip, ino_t parentino, struct ucred *cred) |
| 1058 | { |
| 1059 | off_t off; |
| 1060 | struct dirtemplate dbuf; |
| 1061 | struct direct *dp = (struct direct *)&dbuf; |
| 1062 | int error, count, namlen; |
| 1063 | #define MINDIRSIZ (sizeof (struct dirtemplate) / 2) |
| 1064 | |
| 1065 | for (off = 0; off < ip->i_size; off += dp->d_reclen) { |
| 1066 | error = vn_rdwr(UIO_READ, ITOV(ip), (caddr_t)dp, MINDIRSIZ, off, |
| 1067 | UIO_SYSSPACE, IO_NODELOCKED, cred, &count); |
| 1068 | /* |
| 1069 | * Since we read MINDIRSIZ, residual must |
| 1070 | * be 0 unless we're at end of file. |
| 1071 | */ |
| 1072 | if (error || count != 0) |
| 1073 | return (0); |
| 1074 | /* avoid infinite loops */ |
| 1075 | if (dp->d_reclen == 0) |
| 1076 | return (0); |
| 1077 | /* skip empty entries */ |
| 1078 | if (dp->d_ino == 0 || dp->d_ino == WINO) |
| 1079 | continue; |
| 1080 | /* accept only "." and ".." */ |
| 1081 | # if (BYTE_ORDER == LITTLE_ENDIAN) |
| 1082 | if (OFSFMT(ITOV(ip))) |
| 1083 | namlen = dp->d_type; |
| 1084 | else |
| 1085 | namlen = dp->d_namlen; |
| 1086 | # else |
| 1087 | namlen = dp->d_namlen; |
| 1088 | # endif |
| 1089 | if (namlen > 2) |
| 1090 | return (0); |
| 1091 | if (dp->d_name[0] != '.') |
| 1092 | return (0); |
| 1093 | /* |
| 1094 | * At this point namlen must be 1 or 2. |
| 1095 | * 1 implies ".", 2 implies ".." if second |
| 1096 | * char is also "." |
| 1097 | */ |
| 1098 | if (namlen == 1 && dp->d_ino == ip->i_number) |
| 1099 | continue; |
| 1100 | if (dp->d_name[1] == '.' && dp->d_ino == parentino) |
| 1101 | continue; |
| 1102 | return (0); |
| 1103 | } |
| 1104 | return (1); |
| 1105 | } |
| 1106 | |
| 1107 | /* |
| 1108 | * Check if source directory is in the path of the target directory. |
| 1109 | * Target is supplied locked, source is unlocked. |
| 1110 | * The target is always vput before returning. |
| 1111 | */ |
| 1112 | int |
| 1113 | ufs_checkpath(struct inode *source, struct inode *target, struct ucred *cred) |
| 1114 | { |
| 1115 | struct vnode *vp; |
| 1116 | int error, rootino, namlen; |
| 1117 | struct dirtemplate dirbuf; |
| 1118 | |
| 1119 | vp = ITOV(target); |
| 1120 | if (target->i_number == source->i_number) { |
| 1121 | error = EEXIST; |
| 1122 | goto out; |
| 1123 | } |
| 1124 | rootino = ROOTINO; |
| 1125 | error = 0; |
| 1126 | if (target->i_number == rootino) |
| 1127 | goto out; |
| 1128 | |
| 1129 | for (;;) { |
| 1130 | if (vp->v_type != VDIR) { |
| 1131 | error = ENOTDIR; |
| 1132 | break; |
| 1133 | } |
| 1134 | error = vn_rdwr(UIO_READ, vp, (caddr_t)&dirbuf, |
| 1135 | sizeof (struct dirtemplate), (off_t)0, |
| 1136 | UIO_SYSSPACE, IO_NODELOCKED, cred, (int *)0); |
| 1137 | if (error != 0) |
| 1138 | break; |
| 1139 | # if (BYTE_ORDER == LITTLE_ENDIAN) |
| 1140 | if (OFSFMT(vp)) |
| 1141 | namlen = dirbuf.dotdot_type; |
| 1142 | else |
| 1143 | namlen = dirbuf.dotdot_namlen; |
| 1144 | # else |
| 1145 | namlen = dirbuf.dotdot_namlen; |
| 1146 | # endif |
| 1147 | if (namlen != 2 || |
| 1148 | dirbuf.dotdot_name[0] != '.' || |
| 1149 | dirbuf.dotdot_name[1] != '.') { |
| 1150 | error = ENOTDIR; |
| 1151 | break; |
| 1152 | } |
| 1153 | if (dirbuf.dotdot_ino == source->i_number) { |
| 1154 | error = EINVAL; |
| 1155 | break; |
| 1156 | } |
| 1157 | if (dirbuf.dotdot_ino == rootino) |
| 1158 | break; |
| 1159 | vput(vp); |
| 1160 | error = VFS_VGET(vp->v_mount, dirbuf.dotdot_ino, &vp); |
| 1161 | if (error) { |
| 1162 | vp = NULL; |
| 1163 | break; |
| 1164 | } |
| 1165 | } |
| 1166 | |
| 1167 | out: |
| 1168 | if (error == ENOTDIR) |
| 1169 | kprintf("checkpath: .. not a directory\n"); |
| 1170 | if (vp != NULL) |
| 1171 | vput(vp); |
| 1172 | return (error); |
| 1173 | } |