| 1 | /* $NetBSD: ext2fs_lookup.c,v 1.88 2016/08/23 06:40:25 christos Exp $ */ |
| 2 | |
| 3 | /* |
| 4 | * Modified for NetBSD 1.2E |
| 5 | * May 1997, Manuel Bouyer |
| 6 | * Laboratoire d'informatique de Paris VI |
| 7 | */ |
| 8 | /* |
| 9 | * modified for Lites 1.1 |
| 10 | * |
| 11 | * Aug 1995, Godmar Back (gback@cs.utah.edu) |
| 12 | * University of Utah, Department of Computer Science |
| 13 | */ |
| 14 | /* |
| 15 | * Copyright (c) 1989, 1993 |
| 16 | * The Regents of the University of California. All rights reserved. |
| 17 | * (c) UNIX System Laboratories, Inc. |
| 18 | * All or some portions of this file are derived from material licensed |
| 19 | * to the University of California by American Telephone and Telegraph |
| 20 | * Co. or Unix System Laboratories, Inc. and are reproduced herein with |
| 21 | * the permission of UNIX System Laboratories, Inc. |
| 22 | * |
| 23 | * Redistribution and use in source and binary forms, with or without |
| 24 | * modification, are permitted provided that the following conditions |
| 25 | * are met: |
| 26 | * 1. Redistributions of source code must retain the above copyright |
| 27 | * notice, this list of conditions and the following disclaimer. |
| 28 | * 2. Redistributions in binary form must reproduce the above copyright |
| 29 | * notice, this list of conditions and the following disclaimer in the |
| 30 | * documentation and/or other materials provided with the distribution. |
| 31 | * 3. Neither the name of the University nor the names of its contributors |
| 32 | * may be used to endorse or promote products derived from this software |
| 33 | * without specific prior written permission. |
| 34 | * |
| 35 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| 36 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 37 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 38 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 39 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 40 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 41 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 42 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 43 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 44 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 45 | * SUCH DAMAGE. |
| 46 | * |
| 47 | * @(#)ufs_lookup.c 8.6 (Berkeley) 4/1/94 |
| 48 | */ |
| 49 | |
| 50 | #include <sys/cdefs.h> |
| 51 | __KERNEL_RCSID(0, "$NetBSD: ext2fs_lookup.c,v 1.88 2016/08/23 06:40:25 christos Exp $" ); |
| 52 | |
| 53 | #include <sys/param.h> |
| 54 | #include <sys/systm.h> |
| 55 | #include <sys/namei.h> |
| 56 | #include <sys/buf.h> |
| 57 | #include <sys/file.h> |
| 58 | #include <sys/mount.h> |
| 59 | #include <sys/vnode.h> |
| 60 | #include <sys/kmem.h> |
| 61 | #include <sys/malloc.h> |
| 62 | #include <sys/dirent.h> |
| 63 | #include <sys/kauth.h> |
| 64 | #include <sys/proc.h> |
| 65 | |
| 66 | #include <ufs/ufs/inode.h> |
| 67 | #include <ufs/ufs/ufsmount.h> |
| 68 | #include <ufs/ufs/ufs_extern.h> |
| 69 | |
| 70 | #include <ufs/ext2fs/ext2fs_extern.h> |
| 71 | #include <ufs/ext2fs/ext2fs_dir.h> |
| 72 | #include <ufs/ext2fs/ext2fs.h> |
| 73 | #include <ufs/ext2fs/ext2fs_htree.h> |
| 74 | |
| 75 | #include <miscfs/genfs/genfs.h> |
| 76 | |
| 77 | extern int dirchk; |
| 78 | |
| 79 | static void ext2fs_dirconv2ffs(struct m_ext2fs *fs, |
| 80 | struct ext2fs_direct *e2dir, |
| 81 | struct dirent *ffsdir); |
| 82 | static int ext2fs_dirbadentry(struct vnode *dp, |
| 83 | struct ext2fs_direct *de, |
| 84 | int entryoffsetinblock); |
| 85 | |
| 86 | /* |
| 87 | * the problem that is tackled below is the fact that FFS |
| 88 | * includes the terminating zero on disk while EXT2FS doesn't |
| 89 | * this implies that we need to introduce some padding. |
| 90 | * For instance, a filename "sbin" has normally a reclen 12 |
| 91 | * in EXT2, but 16 in FFS. |
| 92 | * This reminds me of that Pepsi commercial: 'Kid saved a lousy nine cents...' |
| 93 | * If it wasn't for that, the complete ufs code for directories would |
| 94 | * have worked w/o changes (except for the difference in DIRBLKSIZ) |
| 95 | */ |
| 96 | static void |
| 97 | ext2fs_dirconv2ffs(struct m_ext2fs *fs, struct ext2fs_direct *e2dir, struct dirent *ffsdir) |
| 98 | { |
| 99 | memset(ffsdir, 0, sizeof(struct dirent)); |
| 100 | ffsdir->d_fileno = fs2h32(e2dir->e2d_ino); |
| 101 | ffsdir->d_namlen = e2dir->e2d_namlen; |
| 102 | |
| 103 | if (EXT2F_HAS_INCOMPAT_FEATURE(fs, EXT2F_INCOMPAT_FTYPE)) |
| 104 | ffsdir->d_type = ext2dt2dt(e2dir->e2d_type); |
| 105 | else |
| 106 | ffsdir->d_type = DT_UNKNOWN; |
| 107 | |
| 108 | #ifdef DIAGNOSTIC |
| 109 | #if MAXNAMLEN < E2FS_MAXNAMLEN |
| 110 | /* |
| 111 | * we should handle this more gracefully ! |
| 112 | */ |
| 113 | if (e2dir->e2d_namlen > MAXNAMLEN) |
| 114 | panic("ext2fs: e2dir->e2d_namlen" ); |
| 115 | #endif |
| 116 | #endif |
| 117 | strncpy(ffsdir->d_name, e2dir->e2d_name, ffsdir->d_namlen); |
| 118 | |
| 119 | /* Godmar thinks: since e2dir->e2d_reclen can be big and means |
| 120 | nothing anyway, we compute our own reclen according to what |
| 121 | we think is right |
| 122 | */ |
| 123 | ffsdir->d_reclen = _DIRENT_SIZE(ffsdir); |
| 124 | } |
| 125 | |
| 126 | static int |
| 127 | ext2fs_is_dot_entry(struct componentname *cnp) |
| 128 | { |
| 129 | return cnp->cn_namelen <= 2 && cnp->cn_nameptr[0] == '.' && |
| 130 | (cnp->cn_nameptr[1] == '.' || cnp->cn_nameptr[1] == '\0'); |
| 131 | } |
| 132 | |
| 133 | /* |
| 134 | * Vnode op for reading directories. |
| 135 | * |
| 136 | * Convert the on-disk entries to <sys/dirent.h> entries. |
| 137 | * the problem is that the conversion will blow up some entries by four bytes, |
| 138 | * so it can't be done in place. This is too bad. Right now the conversion is |
| 139 | * done entry by entry, the converted entry is sent via uiomove. |
| 140 | * |
| 141 | * XXX allocate a buffer, convert as many entries as possible, then send |
| 142 | * the whole buffer to uiomove |
| 143 | */ |
| 144 | int |
| 145 | ext2fs_readdir(void *v) |
| 146 | { |
| 147 | struct vop_readdir_args /* { |
| 148 | struct vnode *a_vp; |
| 149 | struct uio *a_uio; |
| 150 | kauth_cred_t a_cred; |
| 151 | int **a_eofflag; |
| 152 | off_t **a_cookies; |
| 153 | int ncookies; |
| 154 | } */ *ap = v; |
| 155 | struct uio *uio = ap->a_uio; |
| 156 | int error; |
| 157 | size_t e2fs_count, readcnt; |
| 158 | struct vnode *vp = ap->a_vp; |
| 159 | struct m_ext2fs *fs = VTOI(vp)->i_e2fs; |
| 160 | |
| 161 | struct ext2fs_direct *dp; |
| 162 | struct dirent *dstd; |
| 163 | struct uio auio; |
| 164 | struct iovec aiov; |
| 165 | void *dirbuf; |
| 166 | off_t off = uio->uio_offset; |
| 167 | off_t *cookies = NULL; |
| 168 | int nc = 0, ncookies = 0; |
| 169 | int e2d_reclen; |
| 170 | |
| 171 | if (vp->v_type != VDIR) |
| 172 | return ENOTDIR; |
| 173 | |
| 174 | e2fs_count = uio->uio_resid; |
| 175 | /* Make sure we don't return partial entries. */ |
| 176 | e2fs_count -= (uio->uio_offset + e2fs_count) & (fs->e2fs_bsize -1); |
| 177 | if (e2fs_count <= 0) |
| 178 | return EINVAL; |
| 179 | |
| 180 | auio = *uio; |
| 181 | auio.uio_iov = &aiov; |
| 182 | auio.uio_iovcnt = 1; |
| 183 | aiov.iov_len = e2fs_count; |
| 184 | auio.uio_resid = e2fs_count; |
| 185 | UIO_SETUP_SYSSPACE(&auio); |
| 186 | dirbuf = kmem_alloc(e2fs_count, KM_SLEEP); |
| 187 | dstd = kmem_zalloc(sizeof(struct dirent), KM_SLEEP); |
| 188 | if (ap->a_ncookies) { |
| 189 | nc = e2fs_count / _DIRENT_MINSIZE((struct dirent *)0); |
| 190 | ncookies = nc; |
| 191 | cookies = malloc(sizeof (off_t) * ncookies, M_TEMP, M_WAITOK); |
| 192 | *ap->a_cookies = cookies; |
| 193 | } |
| 194 | aiov.iov_base = dirbuf; |
| 195 | |
| 196 | error = UFS_BUFRD(ap->a_vp, &auio, 0, ap->a_cred); |
| 197 | if (error == 0) { |
| 198 | readcnt = e2fs_count - auio.uio_resid; |
| 199 | for (dp = (struct ext2fs_direct *)dirbuf; |
| 200 | (char *)dp < (char *)dirbuf + readcnt;) { |
| 201 | e2d_reclen = fs2h16(dp->e2d_reclen); |
| 202 | if (e2d_reclen == 0) { |
| 203 | error = EIO; |
| 204 | break; |
| 205 | } |
| 206 | ext2fs_dirconv2ffs(fs, dp, dstd); |
| 207 | if(dstd->d_reclen > uio->uio_resid) { |
| 208 | break; |
| 209 | } |
| 210 | error = uiomove(dstd, dstd->d_reclen, uio); |
| 211 | if (error != 0) { |
| 212 | break; |
| 213 | } |
| 214 | off = off + e2d_reclen; |
| 215 | if (cookies != NULL) { |
| 216 | *cookies++ = off; |
| 217 | if (--ncookies <= 0){ |
| 218 | break; /* out of cookies */ |
| 219 | } |
| 220 | } |
| 221 | /* advance dp */ |
| 222 | dp = (struct ext2fs_direct *) ((char *)dp + e2d_reclen); |
| 223 | } |
| 224 | /* we need to correct uio_offset */ |
| 225 | uio->uio_offset = off; |
| 226 | } |
| 227 | kmem_free(dirbuf, e2fs_count); |
| 228 | kmem_free(dstd, sizeof(*dstd)); |
| 229 | *ap->a_eofflag = ext2fs_size(VTOI(ap->a_vp)) <= uio->uio_offset; |
| 230 | if (ap->a_ncookies) { |
| 231 | if (error) { |
| 232 | free(*ap->a_cookies, M_TEMP); |
| 233 | *ap->a_ncookies = 0; |
| 234 | *ap->a_cookies = NULL; |
| 235 | } else |
| 236 | *ap->a_ncookies = nc - ncookies; |
| 237 | } |
| 238 | return error; |
| 239 | } |
| 240 | |
| 241 | /* |
| 242 | * Convert a component of a pathname into a pointer to a locked inode. |
| 243 | * This is a very central and rather complicated routine. |
| 244 | * If the file system is not maintained in a strict tree hierarchy, |
| 245 | * this can result in a deadlock situation (see comments in code below). |
| 246 | * |
| 247 | * The cnp->cn_nameiop argument is LOOKUP, CREATE, RENAME, or DELETE depending |
| 248 | * on whether the name is to be looked up, created, renamed, or deleted. |
| 249 | * When CREATE, RENAME, or DELETE is specified, information usable in |
| 250 | * creating, renaming, or deleting a directory entry may be calculated. |
| 251 | * If flag has LOCKPARENT or'ed into it and the target of the pathname |
| 252 | * exists, lookup returns both the target and its parent directory locked. |
| 253 | * When creating or renaming and LOCKPARENT is specified, the target may |
| 254 | * not be ".". When deleting and LOCKPARENT is specified, the target may |
| 255 | * be "."., but the caller must check to ensure it does an vrele and vput |
| 256 | * instead of two vputs. |
| 257 | * |
| 258 | * Overall outline of ext2fs_lookup: |
| 259 | * |
| 260 | * check accessibility of directory |
| 261 | * look for name in cache, if found, then if at end of path |
| 262 | * and deleting or creating, drop it, else return name |
| 263 | * search for name in directory, to found or notfound |
| 264 | * notfound: |
| 265 | * if creating, return locked directory, leaving info on available slots |
| 266 | * else return error |
| 267 | * found: |
| 268 | * if at end of path and deleting, return information to allow delete |
| 269 | * if at end of path and rewriting (RENAME and LOCKPARENT), lock target |
| 270 | * inode and return info to allow rewrite |
| 271 | * if not at end, add name to cache; if at end and neither creating |
| 272 | * nor deleting, add name to cache |
| 273 | */ |
| 274 | int |
| 275 | ext2fs_lookup(void *v) |
| 276 | { |
| 277 | struct vop_lookup_v2_args /* { |
| 278 | struct vnode *a_dvp; |
| 279 | struct vnode **a_vpp; |
| 280 | struct componentname *a_cnp; |
| 281 | } */ *ap = v; |
| 282 | struct vnode *vdp = ap->a_dvp; /* vnode for directory being searched */ |
| 283 | struct inode *dp = VTOI(vdp); /* inode for directory being searched */ |
| 284 | struct buf *bp; /* a buffer of directory entries */ |
| 285 | struct ext2fs_direct *ep; /* the current directory entry */ |
| 286 | int entryoffsetinblock; /* offset of ep in bp's buffer */ |
| 287 | enum ext2fs_slotstatus slotstatus; |
| 288 | doff_t slotoffset; /* offset of area with free space */ |
| 289 | int slotsize; /* size of area at slotoffset */ |
| 290 | int slotfreespace; /* amount of space free in slot */ |
| 291 | int slotneeded; /* size of the entry we're seeking */ |
| 292 | int numdirpasses; /* strategy for directory search */ |
| 293 | doff_t endsearch; /* offset to end directory search */ |
| 294 | doff_t prevoff; /* prev entry dp->i_offset */ |
| 295 | struct vnode *tdp; /* returned by vcache_get */ |
| 296 | doff_t enduseful; /* pointer past last used dir slot */ |
| 297 | u_long bmask; /* block offset mask */ |
| 298 | int namlen, error; |
| 299 | struct vnode **vpp = ap->a_vpp; |
| 300 | struct componentname *cnp = ap->a_cnp; |
| 301 | kauth_cred_t cred = cnp->cn_cred; |
| 302 | int flags; |
| 303 | int nameiop = cnp->cn_nameiop; |
| 304 | struct ufsmount *ump = dp->i_ump; |
| 305 | int dirblksiz = ump->um_dirblksiz; |
| 306 | ino_t foundino; |
| 307 | struct ufs_lookup_results *results; |
| 308 | |
| 309 | flags = cnp->cn_flags; |
| 310 | |
| 311 | bp = NULL; |
| 312 | slotoffset = -1; |
| 313 | *vpp = NULL; |
| 314 | |
| 315 | /* |
| 316 | * Produce the auxiliary lookup results into i_crap. Increment |
| 317 | * its serial number so elsewhere we can tell if we're using |
| 318 | * stale results. This should not be done this way. XXX. |
| 319 | */ |
| 320 | results = &dp->i_crap; |
| 321 | dp->i_crapcounter++; |
| 322 | |
| 323 | /* |
| 324 | * Check accessiblity of directory. |
| 325 | */ |
| 326 | if ((error = VOP_ACCESS(vdp, VEXEC, cred)) != 0) |
| 327 | return error; |
| 328 | |
| 329 | if ((flags & ISLASTCN) && (vdp->v_mount->mnt_flag & MNT_RDONLY) && |
| 330 | (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME)) |
| 331 | return EROFS; |
| 332 | |
| 333 | /* |
| 334 | * We now have a segment name to search for, and a directory to search. |
| 335 | * |
| 336 | * Before tediously performing a linear scan of the directory, |
| 337 | * check the name cache to see if the directory/name pair |
| 338 | * we are looking for is known already. |
| 339 | */ |
| 340 | if (cache_lookup(vdp, cnp->cn_nameptr, cnp->cn_namelen, |
| 341 | cnp->cn_nameiop, cnp->cn_flags, NULL, vpp)) { |
| 342 | return *vpp == NULLVP ? ENOENT : 0; |
| 343 | } |
| 344 | |
| 345 | /* |
| 346 | * Suppress search for slots unless creating |
| 347 | * file and at end of pathname, in which case |
| 348 | * we watch for a place to put the new file in |
| 349 | * case it doesn't already exist. |
| 350 | */ |
| 351 | slotstatus = FOUND; |
| 352 | slotfreespace = slotsize = slotneeded = 0; |
| 353 | if ((nameiop == CREATE || nameiop == RENAME) && |
| 354 | (flags & ISLASTCN)) { |
| 355 | slotstatus = NONE; |
| 356 | slotneeded = EXT2FS_DIRSIZ(cnp->cn_namelen); |
| 357 | } |
| 358 | |
| 359 | /* |
| 360 | * If there is cached information on a previous search of |
| 361 | * this directory, pick up where we last left off. |
| 362 | * We cache only lookups as these are the most common |
| 363 | * and have the greatest payoff. Caching CREATE has little |
| 364 | * benefit as it usually must search the entire directory |
| 365 | * to determine that the entry does not exist. Caching the |
| 366 | * location of the last DELETE or RENAME has not reduced |
| 367 | * profiling time and hence has been removed in the interest |
| 368 | * of simplicity. |
| 369 | */ |
| 370 | bmask = vdp->v_mount->mnt_stat.f_iosize - 1; |
| 371 | if (nameiop != LOOKUP || results->ulr_diroff == 0 || |
| 372 | results->ulr_diroff >= ext2fs_size(dp)) { |
| 373 | entryoffsetinblock = 0; |
| 374 | results->ulr_offset = 0; |
| 375 | numdirpasses = 1; |
| 376 | } else { |
| 377 | results->ulr_offset = results->ulr_diroff; |
| 378 | if ((entryoffsetinblock = results->ulr_offset & bmask) && |
| 379 | (error = ext2fs_blkatoff(vdp, (off_t)results->ulr_offset, NULL, &bp))) |
| 380 | return error; |
| 381 | numdirpasses = 2; |
| 382 | namecache_count_2passes(); |
| 383 | } |
| 384 | prevoff = results->ulr_offset; |
| 385 | endsearch = roundup(ext2fs_size(dp), dirblksiz); |
| 386 | enduseful = 0; |
| 387 | /* |
| 388 | * Try to lookup dir entry using htree directory index. |
| 389 | * |
| 390 | * If we got an error or we want to find '.' or '..' entry, |
| 391 | * we will fall back to linear search. |
| 392 | */ |
| 393 | if (!ext2fs_is_dot_entry(cnp) && ext2fs_htree_has_idx(dp)) { |
| 394 | doff_t i_offset; /* cached i_offset value */ |
| 395 | struct ext2fs_searchslot ss; |
| 396 | numdirpasses = 1; |
| 397 | entryoffsetinblock = 0; |
| 398 | |
| 399 | int htree_lookup_ret = ext2fs_htree_lookup(dp, cnp->cn_nameptr, |
| 400 | cnp->cn_namelen, &bp, &entryoffsetinblock, &i_offset, |
| 401 | &prevoff, &enduseful, &ss); |
| 402 | switch (htree_lookup_ret) { |
| 403 | case 0: |
| 404 | ep = (void *)((char *)bp->b_data + (i_offset & bmask)); |
| 405 | foundino = ep->e2d_ino; |
| 406 | goto found; |
| 407 | case ENOENT: |
| 408 | i_offset = roundup2(dp->i_size, dp->i_e2fs->e2fs_bsize); |
| 409 | goto notfound; |
| 410 | default: |
| 411 | /* |
| 412 | * Something failed; just fallback to do a linear |
| 413 | * search. |
| 414 | */ |
| 415 | break; |
| 416 | } |
| 417 | } |
| 418 | |
| 419 | searchloop: |
| 420 | while (results->ulr_offset < endsearch) { |
| 421 | if (curcpu()->ci_schedstate.spc_flags & SPCF_SHOULDYIELD) |
| 422 | preempt(); |
| 423 | /* |
| 424 | * If necessary, get the next directory block. |
| 425 | */ |
| 426 | if ((results->ulr_offset & bmask) == 0) { |
| 427 | if (bp != NULL) |
| 428 | brelse(bp, 0); |
| 429 | error = ext2fs_blkatoff(vdp, (off_t)results->ulr_offset, |
| 430 | NULL, &bp); |
| 431 | if (error != 0) |
| 432 | return error; |
| 433 | entryoffsetinblock = 0; |
| 434 | } |
| 435 | /* |
| 436 | * If still looking for a slot, and at a dirblksize |
| 437 | * boundary, have to start looking for free space again. |
| 438 | */ |
| 439 | if (slotstatus == NONE && |
| 440 | (entryoffsetinblock & (dirblksiz - 1)) == 0) { |
| 441 | slotoffset = -1; |
| 442 | slotfreespace = 0; |
| 443 | } |
| 444 | /* |
| 445 | * Get pointer to next entry. |
| 446 | * Full validation checks are slow, so we only check |
| 447 | * enough to insure forward progress through the |
| 448 | * directory. Complete checks can be run by patching |
| 449 | * "dirchk" to be true. |
| 450 | */ |
| 451 | KASSERT(bp != NULL); |
| 452 | ep = (struct ext2fs_direct *) |
| 453 | ((char *)bp->b_data + entryoffsetinblock); |
| 454 | if (ep->e2d_reclen == 0 || |
| 455 | (dirchk && |
| 456 | ext2fs_dirbadentry(vdp, ep, entryoffsetinblock))) { |
| 457 | int i; |
| 458 | |
| 459 | ufs_dirbad(dp, results->ulr_offset, "mangled entry" ); |
| 460 | i = dirblksiz - (entryoffsetinblock & (dirblksiz - 1)); |
| 461 | results->ulr_offset += i; |
| 462 | entryoffsetinblock += i; |
| 463 | continue; |
| 464 | } |
| 465 | |
| 466 | /* |
| 467 | * If an appropriate sized slot has not yet been found, |
| 468 | * check to see if one is available. Also accumulate space |
| 469 | * in the current block so that we can determine if |
| 470 | * compaction is viable. |
| 471 | */ |
| 472 | if (slotstatus != FOUND) { |
| 473 | int size = fs2h16(ep->e2d_reclen); |
| 474 | |
| 475 | if (ep->e2d_ino != 0) |
| 476 | size -= EXT2FS_DIRSIZ(ep->e2d_namlen); |
| 477 | if (size > 0) { |
| 478 | if (size >= slotneeded) { |
| 479 | slotstatus = FOUND; |
| 480 | slotoffset = results->ulr_offset; |
| 481 | slotsize = fs2h16(ep->e2d_reclen); |
| 482 | } else if (slotstatus == NONE) { |
| 483 | slotfreespace += size; |
| 484 | if (slotoffset == -1) |
| 485 | slotoffset = results->ulr_offset; |
| 486 | if (slotfreespace >= slotneeded) { |
| 487 | slotstatus = COMPACT; |
| 488 | slotsize = results->ulr_offset + |
| 489 | fs2h16(ep->e2d_reclen) - |
| 490 | slotoffset; |
| 491 | } |
| 492 | } |
| 493 | } |
| 494 | } |
| 495 | |
| 496 | /* |
| 497 | * Check for a name match. |
| 498 | */ |
| 499 | if (ep->e2d_ino) { |
| 500 | namlen = ep->e2d_namlen; |
| 501 | if (namlen == cnp->cn_namelen && |
| 502 | !memcmp(cnp->cn_nameptr, ep->e2d_name, |
| 503 | (unsigned)namlen)) { |
| 504 | /* |
| 505 | * Save directory entry's inode number and |
| 506 | * reclen in ndp->ni_ufs area, and release |
| 507 | * directory buffer. |
| 508 | */ |
| 509 | foundino = fs2h32(ep->e2d_ino); |
| 510 | results->ulr_reclen = fs2h16(ep->e2d_reclen); |
| 511 | goto found; |
| 512 | } |
| 513 | } |
| 514 | prevoff = results->ulr_offset; |
| 515 | results->ulr_offset += fs2h16(ep->e2d_reclen); |
| 516 | entryoffsetinblock += fs2h16(ep->e2d_reclen); |
| 517 | if (ep->e2d_ino) |
| 518 | enduseful = results->ulr_offset; |
| 519 | } |
| 520 | notfound: |
| 521 | /* |
| 522 | * If we started in the middle of the directory and failed |
| 523 | * to find our target, we must check the beginning as well. |
| 524 | */ |
| 525 | if (numdirpasses == 2) { |
| 526 | numdirpasses--; |
| 527 | results->ulr_offset = 0; |
| 528 | endsearch = results->ulr_diroff; |
| 529 | goto searchloop; |
| 530 | } |
| 531 | if (bp != NULL) |
| 532 | brelse(bp, 0); |
| 533 | /* |
| 534 | * If creating, and at end of pathname and current |
| 535 | * directory has not been removed, then can consider |
| 536 | * allowing file to be created. |
| 537 | */ |
| 538 | if ((nameiop == CREATE || nameiop == RENAME) && |
| 539 | (flags & ISLASTCN) && dp->i_e2fs_nlink != 0) { |
| 540 | /* |
| 541 | * Access for write is interpreted as allowing |
| 542 | * creation of files in the directory. |
| 543 | */ |
| 544 | error = VOP_ACCESS(vdp, VWRITE, cred); |
| 545 | if (error) |
| 546 | return error; |
| 547 | /* |
| 548 | * Return an indication of where the new directory |
| 549 | * entry should be put. If we didn't find a slot, |
| 550 | * then set results->ulr_count to 0 indicating |
| 551 | * that the new slot belongs at the end of the |
| 552 | * directory. If we found a slot, then the new entry |
| 553 | * can be put in the range from results->ulr_offset to |
| 554 | * results->ulr_offset + results->ulr_count. |
| 555 | */ |
| 556 | if (slotstatus == NONE) { |
| 557 | results->ulr_offset = roundup(ext2fs_size(dp), dirblksiz); |
| 558 | results->ulr_count = 0; |
| 559 | enduseful = results->ulr_offset; |
| 560 | } else { |
| 561 | results->ulr_offset = slotoffset; |
| 562 | results->ulr_count = slotsize; |
| 563 | if (enduseful < slotoffset + slotsize) |
| 564 | enduseful = slotoffset + slotsize; |
| 565 | } |
| 566 | results->ulr_endoff = roundup(enduseful, dirblksiz); |
| 567 | #if 0 |
| 568 | dp->i_flag |= IN_CHANGE | IN_UPDATE; |
| 569 | #endif |
| 570 | /* |
| 571 | * We return with the directory locked, so that |
| 572 | * the parameters we set up above will still be |
| 573 | * valid if we actually decide to do a direnter(). |
| 574 | * We return ni_vp == NULL to indicate that the entry |
| 575 | * does not currently exist; we leave a pointer to |
| 576 | * the (locked) directory inode in ndp->ni_dvp. |
| 577 | * |
| 578 | * NB - if the directory is unlocked, then this |
| 579 | * information cannot be used. |
| 580 | */ |
| 581 | return EJUSTRETURN; |
| 582 | } |
| 583 | /* |
| 584 | * Insert name into cache (as non-existent) if appropriate. |
| 585 | */ |
| 586 | if (nameiop != CREATE) { |
| 587 | cache_enter(vdp, *vpp, cnp->cn_nameptr, cnp->cn_namelen, |
| 588 | cnp->cn_flags); |
| 589 | } |
| 590 | return ENOENT; |
| 591 | |
| 592 | found: |
| 593 | if (numdirpasses == 2) |
| 594 | namecache_count_pass2(); |
| 595 | /* |
| 596 | * Check that directory length properly reflects presence |
| 597 | * of this entry. |
| 598 | */ |
| 599 | if (results->ulr_offset + EXT2FS_DIRSIZ(ep->e2d_namlen) > ext2fs_size(dp)) { |
| 600 | ufs_dirbad(dp, results->ulr_offset, "i_size too small" ); |
| 601 | error = ext2fs_setsize(dp, |
| 602 | results->ulr_offset + EXT2FS_DIRSIZ(ep->e2d_namlen)); |
| 603 | if (error) { |
| 604 | brelse(bp, 0); |
| 605 | return error; |
| 606 | } |
| 607 | dp->i_flag |= IN_CHANGE | IN_UPDATE; |
| 608 | uvm_vnp_setsize(vdp, ext2fs_size(dp)); |
| 609 | } |
| 610 | brelse(bp, 0); |
| 611 | |
| 612 | /* |
| 613 | * Found component in pathname. |
| 614 | * If the final component of path name, save information |
| 615 | * in the cache as to where the entry was found. |
| 616 | */ |
| 617 | if ((flags & ISLASTCN) && nameiop == LOOKUP) |
| 618 | results->ulr_diroff = results->ulr_offset &~ (dirblksiz - 1); |
| 619 | |
| 620 | /* |
| 621 | * If deleting, and at end of pathname, return |
| 622 | * parameters which can be used to remove file. |
| 623 | * Lock the inode, being careful with ".". |
| 624 | */ |
| 625 | if (nameiop == DELETE && (flags & ISLASTCN)) { |
| 626 | /* |
| 627 | * Return pointer to current entry in results->ulr_offset, |
| 628 | * and distance past previous entry (if there |
| 629 | * is a previous entry in this block) in results->ulr_count. |
| 630 | * Save directory inode pointer in ndp->ni_dvp for dirremove(). |
| 631 | */ |
| 632 | if ((results->ulr_offset & (dirblksiz - 1)) == 0) |
| 633 | results->ulr_count = 0; |
| 634 | else |
| 635 | results->ulr_count = results->ulr_offset - prevoff; |
| 636 | if (dp->i_number == foundino) { |
| 637 | vref(vdp); |
| 638 | tdp = vdp; |
| 639 | } else { |
| 640 | error = vcache_get(vdp->v_mount, |
| 641 | &foundino, sizeof(foundino), &tdp); |
| 642 | if (error) |
| 643 | return error; |
| 644 | } |
| 645 | /* |
| 646 | * Write access to directory required to delete files. |
| 647 | */ |
| 648 | if ((error = VOP_ACCESS(vdp, VWRITE, cred)) != 0) { |
| 649 | vrele(tdp); |
| 650 | return error; |
| 651 | } |
| 652 | /* |
| 653 | * If directory is "sticky", then user must own |
| 654 | * the directory, or the file in it, else she |
| 655 | * may not delete it (unless she's root). This |
| 656 | * implements append-only directories. |
| 657 | */ |
| 658 | if (dp->i_e2fs_mode & ISVTX) { |
| 659 | error = kauth_authorize_vnode(cred, KAUTH_VNODE_DELETE, |
| 660 | tdp, vdp, genfs_can_sticky(cred, dp->i_uid, |
| 661 | VTOI(tdp)->i_uid)); |
| 662 | if (error) { |
| 663 | vrele(tdp); |
| 664 | return EPERM; |
| 665 | } |
| 666 | } |
| 667 | *vpp = tdp; |
| 668 | return 0; |
| 669 | } |
| 670 | |
| 671 | /* |
| 672 | * If rewriting (RENAME), return the inode and the |
| 673 | * information required to rewrite the present directory |
| 674 | * Must get inode of directory entry to verify it's a |
| 675 | * regular file, or empty directory. |
| 676 | */ |
| 677 | if (nameiop == RENAME && (flags & ISLASTCN)) { |
| 678 | error = VOP_ACCESS(vdp, VWRITE, cred); |
| 679 | if (error) |
| 680 | return error; |
| 681 | /* |
| 682 | * Careful about locking second inode. |
| 683 | * This can only occur if the target is ".". |
| 684 | */ |
| 685 | if (dp->i_number == foundino) |
| 686 | return EISDIR; |
| 687 | error = vcache_get(vdp->v_mount, |
| 688 | &foundino, sizeof(foundino), &tdp); |
| 689 | if (error) |
| 690 | return error; |
| 691 | *vpp = tdp; |
| 692 | return 0; |
| 693 | } |
| 694 | |
| 695 | if (dp->i_number == foundino) { |
| 696 | vref(vdp); /* we want ourself, ie "." */ |
| 697 | *vpp = vdp; |
| 698 | } else { |
| 699 | error = vcache_get(vdp->v_mount, |
| 700 | &foundino, sizeof(foundino), &tdp); |
| 701 | if (error) |
| 702 | return error; |
| 703 | *vpp = tdp; |
| 704 | } |
| 705 | |
| 706 | /* |
| 707 | * Insert name into cache if appropriate. |
| 708 | */ |
| 709 | cache_enter(vdp, *vpp, cnp->cn_nameptr, cnp->cn_namelen, cnp->cn_flags); |
| 710 | return 0; |
| 711 | } |
| 712 | static void |
| 713 | ext2fs_accumulatespace (struct ext2fs_searchslot *ssp, struct ext2fs_direct *ep, |
| 714 | doff_t *offp) |
| 715 | { |
| 716 | int size = ep->e2d_reclen; |
| 717 | |
| 718 | if (ep->e2d_ino != 0) |
| 719 | size -= EXT2_DIR_REC_LEN(ep->e2d_namlen); |
| 720 | |
| 721 | if (size <= 0) |
| 722 | return; |
| 723 | |
| 724 | if (size >= ssp->slotneeded) { |
| 725 | ssp->slotstatus = FOUND; |
| 726 | ssp->slotoffset = *offp; |
| 727 | ssp->slotsize = ep->e2d_reclen; |
| 728 | return; |
| 729 | } |
| 730 | |
| 731 | if (ssp->slotstatus != NONE) |
| 732 | return; |
| 733 | |
| 734 | ssp->slotfreespace += size; |
| 735 | if (ssp->slotoffset == -1) |
| 736 | ssp->slotoffset = *offp; |
| 737 | |
| 738 | if (ssp->slotfreespace >= ssp->slotneeded) { |
| 739 | ssp->slotstatus = COMPACT; |
| 740 | ssp->slotsize = *offp + ep->e2d_reclen - ssp->slotoffset; |
| 741 | } |
| 742 | } |
| 743 | |
| 744 | int |
| 745 | ext2fs_search_dirblock(struct inode *ip, void *data, int *foundp, |
| 746 | const char *name, int namelen, int *entryoffsetinblockp, |
| 747 | doff_t *offp, doff_t *prevoffp, doff_t *endusefulp, |
| 748 | struct ext2fs_searchslot *ssp) |
| 749 | { |
| 750 | struct vnode *vdp = ITOV(ip); |
| 751 | struct ext2fs_direct *ep, *top; |
| 752 | uint32_t bsize = ip->i_e2fs->e2fs_bsize; |
| 753 | int offset = *entryoffsetinblockp; |
| 754 | int namlen; |
| 755 | |
| 756 | ep = (void *)((char *)data + offset); |
| 757 | top = (void *)((char *)data + bsize - EXT2_DIR_REC_LEN(0)); |
| 758 | |
| 759 | while (ep < top) { |
| 760 | /* |
| 761 | * Full validation checks are slow, so we only check |
| 762 | * enough to insure forward progress through the |
| 763 | * directory. Complete checks can be run by setting |
| 764 | * "vfs.e2fs.dirchk" to be true. |
| 765 | */ |
| 766 | if (ep->e2d_reclen == 0 || |
| 767 | (dirchk && ext2fs_dirbadentry(vdp, ep, offset))) { |
| 768 | int i; |
| 769 | ufs_dirbad(ip, *offp, "mangled entry" ); |
| 770 | i = bsize - (offset & (bsize - 1)); |
| 771 | *offp += i; |
| 772 | offset += i; |
| 773 | continue; |
| 774 | } |
| 775 | |
| 776 | /* |
| 777 | * If an appropriate sized slot has not yet been found, |
| 778 | * check to see if one is available. Also accumulate space |
| 779 | * in the current block so that we can determine if |
| 780 | * compaction is viable. |
| 781 | */ |
| 782 | if (ssp->slotstatus != FOUND) |
| 783 | ext2fs_accumulatespace(ssp, ep, offp); |
| 784 | |
| 785 | /* |
| 786 | * Check for a name match. |
| 787 | */ |
| 788 | if (ep->e2d_ino) { |
| 789 | namlen = ep->e2d_namlen; |
| 790 | if (namlen == namelen && |
| 791 | !memcmp(name, ep->e2d_name, (unsigned)namlen)) { |
| 792 | /* |
| 793 | * Save directory entry's inode number and |
| 794 | * reclen in ndp->ni_ufs area, and release |
| 795 | * directory buffer. |
| 796 | */ |
| 797 | *foundp = 1; |
| 798 | return 0; |
| 799 | } |
| 800 | } |
| 801 | *prevoffp = *offp; |
| 802 | *offp += ep->e2d_reclen; |
| 803 | offset += ep->e2d_reclen; |
| 804 | *entryoffsetinblockp = offset; |
| 805 | if (ep->e2d_ino) |
| 806 | *endusefulp = *offp; |
| 807 | /* |
| 808 | * Get pointer to the next entry. |
| 809 | */ |
| 810 | ep = (void *)((char *)data + offset); |
| 811 | } |
| 812 | |
| 813 | return 0; |
| 814 | } |
| 815 | |
| 816 | /* |
| 817 | * Do consistency checking on a directory entry: |
| 818 | * record length must be multiple of 4 |
| 819 | * entry must fit in rest of its dirblksize block |
| 820 | * record must be large enough to contain entry |
| 821 | * name is not longer than EXT2FS_MAXNAMLEN |
| 822 | * name must be as long as advertised, and null terminated |
| 823 | */ |
| 824 | /* |
| 825 | * changed so that it confirms to ext2fs_check_dir_entry |
| 826 | */ |
| 827 | static int |
| 828 | ext2fs_dirbadentry(struct vnode *dp, struct ext2fs_direct *de, |
| 829 | int entryoffsetinblock) |
| 830 | { |
| 831 | struct ufsmount *ump = VFSTOUFS(dp->v_mount); |
| 832 | int dirblksiz = ump->um_dirblksiz; |
| 833 | |
| 834 | const char *error_msg = NULL; |
| 835 | int reclen = fs2h16(de->e2d_reclen); |
| 836 | int namlen = de->e2d_namlen; |
| 837 | |
| 838 | if (reclen < EXT2FS_DIRSIZ(1)) /* e2d_namlen = 1 */ |
| 839 | error_msg = "rec_len is smaller than minimal" ; |
| 840 | else if (reclen % 4 != 0) |
| 841 | error_msg = "rec_len % 4 != 0" ; |
| 842 | else if (namlen > EXT2FS_MAXNAMLEN) |
| 843 | error_msg = "namlen > EXT2FS_MAXNAMLEN" ; |
| 844 | else if (reclen < EXT2FS_DIRSIZ(namlen)) |
| 845 | error_msg = "reclen is too small for name_len" ; |
| 846 | else if (entryoffsetinblock + reclen > dirblksiz) |
| 847 | error_msg = "directory entry across blocks" ; |
| 848 | else if (fs2h32(de->e2d_ino) > |
| 849 | VTOI(dp)->i_e2fs->e2fs.e2fs_icount) |
| 850 | error_msg = "inode out of bounds" ; |
| 851 | |
| 852 | if (error_msg != NULL) { |
| 853 | printf( "bad directory entry: %s\n" |
| 854 | "offset=%d, inode=%lu, rec_len=%d, name_len=%d \n" , |
| 855 | error_msg, entryoffsetinblock, |
| 856 | (unsigned long) fs2h32(de->e2d_ino), |
| 857 | reclen, namlen); |
| 858 | panic("ext2fs_dirbadentry" ); |
| 859 | } |
| 860 | return error_msg == NULL ? 0 : 1; |
| 861 | } |
| 862 | |
| 863 | /* |
| 864 | * Write a directory entry after a call to namei, using the parameters |
| 865 | * that it left in nameidata. The argument ip is the inode which the new |
| 866 | * directory entry will refer to. Dvp is a pointer to the directory to |
| 867 | * be written, which was left locked by namei. Remaining parameters |
| 868 | * (ulr_offset, ulr_count) indicate how the space for the new |
| 869 | * entry is to be obtained. |
| 870 | */ |
| 871 | int |
| 872 | ext2fs_direnter(struct inode *ip, struct vnode *dvp, |
| 873 | const struct ufs_lookup_results *ulr, struct componentname *cnp) |
| 874 | { |
| 875 | struct inode *dp; |
| 876 | struct ext2fs_direct newdir; |
| 877 | struct iovec aiov; |
| 878 | struct uio auio; |
| 879 | int error; |
| 880 | struct ufsmount *ump = VFSTOUFS(dvp->v_mount); |
| 881 | int dirblksiz = ump->um_dirblksiz; |
| 882 | size_t newentrysize; |
| 883 | |
| 884 | dp = VTOI(dvp); |
| 885 | |
| 886 | newdir.e2d_ino = h2fs32(ip->i_number); |
| 887 | newdir.e2d_namlen = cnp->cn_namelen; |
| 888 | if (EXT2F_HAS_INCOMPAT_FEATURE(ip->i_e2fs, EXT2F_INCOMPAT_FTYPE)) { |
| 889 | newdir.e2d_type = inot2ext2dt(IFTODT(ip->i_e2fs_mode)); |
| 890 | } else { |
| 891 | newdir.e2d_type = 0; |
| 892 | } |
| 893 | memcpy(newdir.e2d_name, cnp->cn_nameptr, (unsigned)cnp->cn_namelen + 1); |
| 894 | newentrysize = EXT2FS_DIRSIZ(cnp->cn_namelen); |
| 895 | |
| 896 | if (ext2fs_htree_has_idx(dp)) { |
| 897 | error = ext2fs_htree_add_entry(dvp, &newdir, cnp, newentrysize); |
| 898 | if (error) { |
| 899 | dp->i_e2fs_flags &= ~EXT2_INDEX; |
| 900 | dp->i_flag |= IN_CHANGE | IN_UPDATE; |
| 901 | } |
| 902 | return error; |
| 903 | } |
| 904 | |
| 905 | /* |
| 906 | * TODO check if Htree index is not created for the directory then |
| 907 | * create one if directory entries get overflew the first dir-block |
| 908 | */ |
| 909 | if (ulr->ulr_count == 0) { |
| 910 | /* |
| 911 | * If ulr_count is 0, then namei could find no |
| 912 | * space in the directory. Here, ulr_offset will |
| 913 | * be on a directory block boundary and we will write the |
| 914 | * new entry into a fresh block. |
| 915 | */ |
| 916 | if (ulr->ulr_offset & (dirblksiz - 1)) |
| 917 | panic("ext2fs_direnter: newblk" ); |
| 918 | auio.uio_offset = ulr->ulr_offset; |
| 919 | newdir.e2d_reclen = h2fs16(dirblksiz); |
| 920 | auio.uio_resid = newentrysize; |
| 921 | aiov.iov_len = newentrysize; |
| 922 | aiov.iov_base = (void *)&newdir; |
| 923 | auio.uio_iov = &aiov; |
| 924 | auio.uio_iovcnt = 1; |
| 925 | auio.uio_rw = UIO_WRITE; |
| 926 | UIO_SETUP_SYSSPACE(&auio); |
| 927 | error = ext2fs_bufwr(dvp, &auio, IO_SYNC, cnp->cn_cred); |
| 928 | if (dirblksiz > dvp->v_mount->mnt_stat.f_bsize) |
| 929 | /* XXX should grow with balloc() */ |
| 930 | panic("ext2fs_direnter: frag size" ); |
| 931 | else if (!error) { |
| 932 | error = ext2fs_setsize(dp, |
| 933 | roundup(ext2fs_size(dp), dirblksiz)); |
| 934 | if (error) |
| 935 | return error; |
| 936 | dp->i_flag |= IN_CHANGE; |
| 937 | uvm_vnp_setsize(dvp, ext2fs_size(dp)); |
| 938 | } |
| 939 | return error; |
| 940 | } |
| 941 | |
| 942 | error = ext2fs_add_entry(dvp, &newdir, ulr, newentrysize); |
| 943 | |
| 944 | if (!error && ulr->ulr_endoff && ulr->ulr_endoff < ext2fs_size(dp)) |
| 945 | error = ext2fs_truncate(dvp, (off_t)ulr->ulr_endoff, IO_SYNC, |
| 946 | cnp->cn_cred); |
| 947 | return error; |
| 948 | } |
| 949 | |
| 950 | /* |
| 951 | * Insert an entry into the directory block. |
| 952 | * Compact the contents. |
| 953 | */ |
| 954 | |
| 955 | int |
| 956 | ext2fs_add_entry(struct vnode* dvp, struct ext2fs_direct *entry, |
| 957 | const struct ufs_lookup_results *ulr, size_t newentrysize) |
| 958 | { |
| 959 | struct ext2fs_direct *ep, *nep; |
| 960 | struct inode *dp; |
| 961 | struct buf *bp; |
| 962 | u_int dsize; |
| 963 | int error, loc, spacefree; |
| 964 | char *dirbuf; |
| 965 | |
| 966 | dp = VTOI(dvp); |
| 967 | |
| 968 | /* |
| 969 | * If ulr_count is non-zero, then namei found space |
| 970 | * for the new entry in the range ulr_offset to |
| 971 | * ulr_offset + ulr_count in the directory. |
| 972 | * To use this space, we may have to compact the entries located |
| 973 | * there, by copying them together towards the beginning of the |
| 974 | * block, leaving the free space in one usable chunk at the end. |
| 975 | */ |
| 976 | |
| 977 | /* |
| 978 | * Get the block containing the space for the new directory entry. |
| 979 | */ |
| 980 | if ((error = ext2fs_blkatoff(dvp, (off_t)ulr->ulr_offset, &dirbuf, &bp)) != 0) |
| 981 | return error; |
| 982 | /* |
| 983 | * Find space for the new entry. In the simple case, the entry at |
| 984 | * offset base will have the space. If it does not, then namei |
| 985 | * arranged that compacting the region ulr_offset to |
| 986 | * ulr_offset + ulr_count would yield the |
| 987 | * space. |
| 988 | */ |
| 989 | ep = (struct ext2fs_direct *)dirbuf; |
| 990 | dsize = EXT2FS_DIRSIZ(ep->e2d_namlen); |
| 991 | spacefree = fs2h16(ep->e2d_reclen) - dsize; |
| 992 | for (loc = fs2h16(ep->e2d_reclen); loc < ulr->ulr_count;) { |
| 993 | nep = (struct ext2fs_direct *)(dirbuf + loc); |
| 994 | if (ep->e2d_ino) { |
| 995 | /* trim the existing slot */ |
| 996 | ep->e2d_reclen = h2fs16(dsize); |
| 997 | ep = (struct ext2fs_direct *)((char *)ep + dsize); |
| 998 | } else { |
| 999 | /* overwrite; nothing there; header is ours */ |
| 1000 | spacefree += dsize; |
| 1001 | } |
| 1002 | dsize = EXT2FS_DIRSIZ(nep->e2d_namlen); |
| 1003 | spacefree += fs2h16(nep->e2d_reclen) - dsize; |
| 1004 | loc += fs2h16(nep->e2d_reclen); |
| 1005 | memcpy((void *)ep, (void *)nep, dsize); |
| 1006 | } |
| 1007 | /* |
| 1008 | * Update the pointer fields in the previous entry (if any), |
| 1009 | * copy in the new entry, and write out the block. |
| 1010 | */ |
| 1011 | if (ep->e2d_ino == 0) { |
| 1012 | #ifdef DIAGNOSTIC |
| 1013 | if (spacefree + dsize < newentrysize) |
| 1014 | panic("ext2fs_direnter: compact1" ); |
| 1015 | #endif |
| 1016 | entry->e2d_reclen = h2fs16(spacefree + dsize); |
| 1017 | } else { |
| 1018 | #ifdef DIAGNOSTIC |
| 1019 | if (spacefree < newentrysize) { |
| 1020 | printf("ext2fs_direnter: compact2 %u %u" , |
| 1021 | (u_int)spacefree, (u_int)newentrysize); |
| 1022 | panic("ext2fs_direnter: compact2" ); |
| 1023 | } |
| 1024 | #endif |
| 1025 | entry->e2d_reclen = h2fs16(spacefree); |
| 1026 | ep->e2d_reclen = h2fs16(dsize); |
| 1027 | ep = (struct ext2fs_direct *)((char *)ep + dsize); |
| 1028 | } |
| 1029 | memcpy(ep, entry, (u_int)newentrysize); |
| 1030 | error = VOP_BWRITE(bp->b_vp, bp); |
| 1031 | dp->i_flag |= IN_CHANGE | IN_UPDATE; |
| 1032 | return error; |
| 1033 | } |
| 1034 | |
| 1035 | /* |
| 1036 | * Remove a directory entry after a call to namei, using |
| 1037 | * the auxiliary results it provided. The entry |
| 1038 | * ulr_offset contains the offset into the directory of the |
| 1039 | * entry to be eliminated. The ulr_count field contains the |
| 1040 | * size of the previous record in the directory. If this |
| 1041 | * is 0, the first entry is being deleted, so we need only |
| 1042 | * zero the inode number to mark the entry as free. If the |
| 1043 | * entry is not the first in the directory, we must reclaim |
| 1044 | * the space of the now empty record by adding the record size |
| 1045 | * to the size of the previous entry. |
| 1046 | */ |
| 1047 | int |
| 1048 | ext2fs_dirremove(struct vnode *dvp, const struct ufs_lookup_results *ulr, |
| 1049 | struct componentname *cnp) |
| 1050 | { |
| 1051 | struct inode *dp; |
| 1052 | struct ext2fs_direct *ep; |
| 1053 | struct buf *bp; |
| 1054 | int error; |
| 1055 | |
| 1056 | dp = VTOI(dvp); |
| 1057 | |
| 1058 | if (ulr->ulr_count == 0) { |
| 1059 | /* |
| 1060 | * First entry in block: set d_ino to zero. |
| 1061 | */ |
| 1062 | error = ext2fs_blkatoff(dvp, (off_t)ulr->ulr_offset, |
| 1063 | (void *)&ep, &bp); |
| 1064 | if (error != 0) |
| 1065 | return error; |
| 1066 | ep->e2d_ino = 0; |
| 1067 | error = VOP_BWRITE(bp->b_vp, bp); |
| 1068 | dp->i_flag |= IN_CHANGE | IN_UPDATE; |
| 1069 | return error; |
| 1070 | } |
| 1071 | /* |
| 1072 | * Collapse new free space into previous entry. |
| 1073 | */ |
| 1074 | error = ext2fs_blkatoff(dvp, (off_t)(ulr->ulr_offset - ulr->ulr_count), |
| 1075 | (void *)&ep, &bp); |
| 1076 | if (error != 0) |
| 1077 | return error; |
| 1078 | ep->e2d_reclen = h2fs16(fs2h16(ep->e2d_reclen) + ulr->ulr_reclen); |
| 1079 | error = VOP_BWRITE(bp->b_vp, bp); |
| 1080 | dp->i_flag |= IN_CHANGE | IN_UPDATE; |
| 1081 | return error; |
| 1082 | } |
| 1083 | |
| 1084 | /* |
| 1085 | * Rewrite an existing directory entry to point at the inode |
| 1086 | * supplied. The parameters describing the directory entry are |
| 1087 | * set up by a call to namei. |
| 1088 | */ |
| 1089 | int |
| 1090 | ext2fs_dirrewrite(struct inode *dp, const struct ufs_lookup_results *ulr, |
| 1091 | struct inode *ip, struct componentname *cnp) |
| 1092 | { |
| 1093 | struct buf *bp; |
| 1094 | struct ext2fs_direct *ep; |
| 1095 | struct vnode *vdp = ITOV(dp); |
| 1096 | int error; |
| 1097 | |
| 1098 | error = ext2fs_blkatoff(vdp, (off_t)ulr->ulr_offset, (void *)&ep, &bp); |
| 1099 | if (error != 0) |
| 1100 | return error; |
| 1101 | ep->e2d_ino = h2fs32(ip->i_number); |
| 1102 | if (EXT2F_HAS_INCOMPAT_FEATURE(dp->i_e2fs, EXT2F_INCOMPAT_FTYPE)) { |
| 1103 | ep->e2d_type = inot2ext2dt(IFTODT(ip->i_e2fs_mode)); |
| 1104 | } else { |
| 1105 | ep->e2d_type = 0; |
| 1106 | } |
| 1107 | error = VOP_BWRITE(bp->b_vp, bp); |
| 1108 | dp->i_flag |= IN_CHANGE | IN_UPDATE; |
| 1109 | return error; |
| 1110 | } |
| 1111 | |
| 1112 | /* |
| 1113 | * Check if a directory is empty or not. |
| 1114 | * Inode supplied must be locked. |
| 1115 | * |
| 1116 | * Using a struct dirtemplate here is not precisely |
| 1117 | * what we want, but better than using a struct ext2fs_direct. |
| 1118 | * |
| 1119 | * NB: does not handle corrupted directories. |
| 1120 | */ |
| 1121 | int |
| 1122 | ext2fs_dirempty(struct inode *ip, ino_t parentino, kauth_cred_t cred) |
| 1123 | { |
| 1124 | off_t off; |
| 1125 | struct ext2fs_dirtemplate dbuf; |
| 1126 | struct ext2fs_direct *dp = (struct ext2fs_direct *)&dbuf; |
| 1127 | int error, namlen; |
| 1128 | size_t count; |
| 1129 | |
| 1130 | #define MINDIRSIZ (sizeof (struct ext2fs_dirtemplate) / 2) |
| 1131 | |
| 1132 | for (off = 0; off < ext2fs_size(ip); off += fs2h16(dp->e2d_reclen)) { |
| 1133 | error = ufs_bufio(UIO_READ, ITOV(ip), (void *)dp, MINDIRSIZ, |
| 1134 | off, IO_NODELOCKED, cred, &count, NULL); |
| 1135 | /* |
| 1136 | * Since we read MINDIRSIZ, residual must |
| 1137 | * be 0 unless we're at end of file. |
| 1138 | */ |
| 1139 | if (error || count != 0) |
| 1140 | return 0; |
| 1141 | /* avoid infinite loops */ |
| 1142 | if (dp->e2d_reclen == 0) |
| 1143 | return 0; |
| 1144 | /* skip empty entries */ |
| 1145 | if (dp->e2d_ino == 0) |
| 1146 | continue; |
| 1147 | /* accept only "." and ".." */ |
| 1148 | namlen = dp->e2d_namlen; |
| 1149 | if (namlen > 2) |
| 1150 | return 0; |
| 1151 | if (dp->e2d_name[0] != '.') |
| 1152 | return 0; |
| 1153 | /* |
| 1154 | * At this point namlen must be 1 or 2. |
| 1155 | * 1 implies ".", 2 implies ".." if second |
| 1156 | * char is also "." |
| 1157 | */ |
| 1158 | if (namlen == 1) |
| 1159 | continue; |
| 1160 | if (dp->e2d_name[1] == '.' && fs2h32(dp->e2d_ino) == parentino) |
| 1161 | continue; |
| 1162 | return 0; |
| 1163 | } |
| 1164 | return 1; |
| 1165 | } |
| 1166 | |