| 1 | /* |
| 2 | * modified for Lites 1.1 |
| 3 | * |
| 4 | * Aug 1995, Godmar Back (gback@cs.utah.edu) |
| 5 | * University of Utah, Department of Computer Science |
| 6 | * |
| 7 | * $FreeBSD: src/sys/gnu/ext2fs/ext2_lookup.c,v 1.21.2.3 2002/11/17 02:02:42 bde Exp $ |
| 8 | */ |
| 9 | /* |
| 10 | * Copyright (c) 1989, 1993 |
| 11 | * The Regents of the University of California. All rights reserved. |
| 12 | * (c) UNIX System Laboratories, Inc. |
| 13 | * All or some portions of this file are derived from material licensed |
| 14 | * to the University of California by American Telephone and Telegraph |
| 15 | * Co. or Unix System Laboratories, Inc. and are reproduced herein with |
| 16 | * the permission of UNIX System Laboratories, Inc. |
| 17 | * |
| 18 | * Redistribution and use in source and binary forms, with or without |
| 19 | * modification, are permitted provided that the following conditions |
| 20 | * are met: |
| 21 | * 1. Redistributions of source code must retain the above copyright |
| 22 | * notice, this list of conditions and the following disclaimer. |
| 23 | * 2. Redistributions in binary form must reproduce the above copyright |
| 24 | * notice, this list of conditions and the following disclaimer in the |
| 25 | * documentation and/or other materials provided with the distribution. |
| 26 | * 3. All advertising materials mentioning features or use of this software |
| 27 | * must display the following acknowledgement: |
| 28 | * This product includes software developed by the University of |
| 29 | * California, Berkeley and its contributors. |
| 30 | * 4. Neither the name of the University nor the names of its contributors |
| 31 | * may be used to endorse or promote products derived from this software |
| 32 | * without specific prior written permission. |
| 33 | * |
| 34 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| 35 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 36 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 37 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 38 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 39 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 40 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 41 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 42 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 43 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 44 | * SUCH DAMAGE. |
| 45 | * |
| 46 | * @(#)ufs_lookup.c 8.6 (Berkeley) 4/1/94 |
| 47 | */ |
| 48 | |
| 49 | #include <sys/param.h> |
| 50 | #include <sys/systm.h> |
| 51 | #include <sys/namei.h> |
| 52 | #include <sys/buf.h> |
| 53 | #include <sys/mount.h> |
| 54 | #include <sys/vnode.h> |
| 55 | #include <sys/malloc.h> |
| 56 | #include <sys/dirent.h> |
| 57 | |
| 58 | #include "quota.h" |
| 59 | #include "inode.h" |
| 60 | #include "dir.h" |
| 61 | #include "ext2mount.h" |
| 62 | #include "ext2_extern.h" |
| 63 | #include "ext2_fs.h" |
| 64 | #include "ext2_fs_sb.h" |
| 65 | |
| 66 | /* |
| 67 | DIRBLKSIZE in ffs is DEV_BSIZE (in most cases 512) |
| 68 | while it is the native blocksize in ext2fs - thus, a #define |
| 69 | is no longer appropriate |
| 70 | */ |
| 71 | #undef DIRBLKSIZ |
| 72 | |
| 73 | extern int dirchk; |
| 74 | |
| 75 | static u_char ext2_ft_to_dt[] = { |
| 76 | DT_UNKNOWN, /* EXT2_FT_UNKNOWN */ |
| 77 | DT_REG, /* EXT2_FT_REG_FILE */ |
| 78 | DT_DIR, /* EXT2_FT_DIR */ |
| 79 | DT_CHR, /* EXT2_FT_CHRDEV */ |
| 80 | DT_BLK, /* EXT2_FT_BLKDEV */ |
| 81 | DT_FIFO, /* EXT2_FT_FIFO */ |
| 82 | DT_SOCK, /* EXT2_FT_SOCK */ |
| 83 | DT_LNK, /* EXT2_FT_SYMLINK */ |
| 84 | }; |
| 85 | #define FTTODT(ft) \ |
| 86 | ((ft) > NELEM(ext2_ft_to_dt) ? \ |
| 87 | DT_UNKNOWN : ext2_ft_to_dt[(ft)]) |
| 88 | |
| 89 | static u_char dt_to_ext2_ft[] = { |
| 90 | EXT2_FT_UNKNOWN, /* DT_UNKNOWN */ |
| 91 | EXT2_FT_FIFO, /* DT_FIFO */ |
| 92 | EXT2_FT_CHRDEV, /* DT_CHR */ |
| 93 | EXT2_FT_UNKNOWN, /* unused */ |
| 94 | EXT2_FT_DIR, /* DT_DIR */ |
| 95 | EXT2_FT_UNKNOWN, /* unused */ |
| 96 | EXT2_FT_BLKDEV, /* DT_BLK */ |
| 97 | EXT2_FT_UNKNOWN, /* unused */ |
| 98 | EXT2_FT_REG_FILE, /* DT_REG */ |
| 99 | EXT2_FT_UNKNOWN, /* unused */ |
| 100 | EXT2_FT_SYMLINK, /* DT_LNK */ |
| 101 | EXT2_FT_UNKNOWN, /* unused */ |
| 102 | EXT2_FT_SOCK, /* DT_SOCK */ |
| 103 | EXT2_FT_UNKNOWN, /* unused */ |
| 104 | EXT2_FT_UNKNOWN, /* DT_WHT */ |
| 105 | }; |
| 106 | #define DTTOFT(dt) \ |
| 107 | ((dt) > NELEM(dt_to_ext2_ft) ? \ |
| 108 | EXT2_FT_UNKNOWN : dt_to_ext2_ft[(dt)]) |
| 109 | |
| 110 | static int ext2_dirbadentry (struct vnode *dp, |
| 111 | struct ext2_dir_entry_2 *de, |
| 112 | int entryoffsetinblock); |
| 113 | |
| 114 | /* |
| 115 | * Vnode op for reading directories. |
| 116 | * |
| 117 | * The routine below assumes that the on-disk format of a directory |
| 118 | * is the same as that defined by <sys/dirent.h>. If the on-disk |
| 119 | * format changes, then it will be necessary to do a conversion |
| 120 | * from the on-disk format that read returns to the format defined |
| 121 | * by <sys/dirent.h>. |
| 122 | */ |
| 123 | /* |
| 124 | * this is exactly what we do here - the problem is that the conversion |
| 125 | * will blow up some entries by four bytes, so it can't be done in place. |
| 126 | * This is too bad. Right now the conversion is done entry by entry, the |
| 127 | * converted entry is sent via uiomove. |
| 128 | * |
| 129 | * XXX allocate a buffer, convert as many entries as possible, then send |
| 130 | * the whole buffer to uiomove |
| 131 | * |
| 132 | * ext2_readdir(struct vnode *a_vp, struct uio *a_uio, struct ucred *a_cred) |
| 133 | */ |
| 134 | int |
| 135 | ext2_readdir(struct vop_readdir_args *ap) |
| 136 | { |
| 137 | struct uio *uio = ap->a_uio; |
| 138 | int count, error; |
| 139 | struct ext2_dir_entry_2 *edp, *dp; |
| 140 | int ncookies; |
| 141 | struct uio auio; |
| 142 | struct iovec aiov; |
| 143 | caddr_t dirbuf; |
| 144 | int DIRBLKSIZ = VTOI(ap->a_vp)->i_e2fs->s_blocksize; |
| 145 | int readcnt, retval; |
| 146 | off_t startoffset = uio->uio_offset; |
| 147 | |
| 148 | if ((error = vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY)) != 0) |
| 149 | return(error); |
| 150 | |
| 151 | count = uio->uio_resid; |
| 152 | /* |
| 153 | * Avoid complications for partial directory entries by adjusting |
| 154 | * the i/o to end at a block boundary. Don't give up (like ufs |
| 155 | * does) if the initial adjustment gives a negative count, since |
| 156 | * many callers don't supply a large enough buffer. The correct |
| 157 | * size is a little larger than DIRBLKSIZ to allow for expansion |
| 158 | * of directory entries, but some callers just use 512. |
| 159 | */ |
| 160 | count -= (uio->uio_offset + count) & (DIRBLKSIZ -1); |
| 161 | if (count <= 0) |
| 162 | count += DIRBLKSIZ; |
| 163 | if (count > MAXBSIZE) /* limit to a reasonable size */ |
| 164 | count = MAXBSIZE; |
| 165 | |
| 166 | #ifdef EXT2FS_DEBUG |
| 167 | kprintf("ext2_readdir: uio_offset = %lld, uio_resid = %d, count = %d\n", |
| 168 | uio->uio_offset, uio->uio_resid, count); |
| 169 | #endif |
| 170 | |
| 171 | auio = *uio; |
| 172 | auio.uio_iov = &aiov; |
| 173 | auio.uio_iovcnt = 1; |
| 174 | auio.uio_resid = count; |
| 175 | auio.uio_segflg = UIO_SYSSPACE; |
| 176 | aiov.iov_len = count; |
| 177 | dirbuf = kmalloc(count, M_TEMP, M_WAITOK); |
| 178 | aiov.iov_base = dirbuf; |
| 179 | error = VOP_READ(ap->a_vp, &auio, 0, ap->a_cred); |
| 180 | if (error == 0) { |
| 181 | readcnt = count - auio.uio_resid; |
| 182 | edp = (struct ext2_dir_entry_2 *)&dirbuf[readcnt]; |
| 183 | ncookies = 0; |
| 184 | for (dp = (struct ext2_dir_entry_2 *)dirbuf; |
| 185 | !error && uio->uio_resid > 0 && dp < edp; ) { |
| 186 | /*- |
| 187 | * "New" ext2fs directory entries differ in 3 ways |
| 188 | * from ufs on-disk ones: |
| 189 | * - the name is not necessarily NUL-terminated. |
| 190 | * - the file type field always exists and always |
| 191 | * follows the name length field. |
| 192 | * - the file type is encoded in a different way. |
| 193 | * |
| 194 | * "Old" ext2fs directory entries need no special |
| 195 | * conversions, since they binary compatible with |
| 196 | * "new" entries having a file type of 0 (i.e., |
| 197 | * EXT2_FT_UNKNOWN). Splitting the old name length |
| 198 | * field didn't make a mess like it did in ufs, |
| 199 | * because ext2fs uses a machine-dependent disk |
| 200 | * layout. |
| 201 | */ |
| 202 | if (dp->rec_len <= 0) { |
| 203 | error = EIO; |
| 204 | break; |
| 205 | } |
| 206 | retval = vop_write_dirent(&error, uio, dp->inode, |
| 207 | FTTODT(dp->file_type), dp->name_len, dp->name); |
| 208 | |
| 209 | if (retval) |
| 210 | break; |
| 211 | /* advance dp */ |
| 212 | dp = (struct ext2_dir_entry_2 *)((char *)dp + dp->rec_len); |
| 213 | if (!error) |
| 214 | ncookies++; |
| 215 | } |
| 216 | /* we need to correct uio_offset */ |
| 217 | uio->uio_offset = startoffset + (caddr_t)dp - dirbuf; |
| 218 | |
| 219 | if (!error && ap->a_ncookies != NULL) { |
| 220 | off_t *cookiep, *cookies, *ecookies; |
| 221 | off_t off; |
| 222 | |
| 223 | if (uio->uio_segflg != UIO_SYSSPACE || uio->uio_iovcnt != 1) |
| 224 | panic("ext2fs_readdir: unexpected uio from NFS server"); |
| 225 | if (ncookies) { |
| 226 | cookies = kmalloc(ncookies * sizeof(off_t), |
| 227 | M_TEMP, M_WAITOK); |
| 228 | } else { |
| 229 | cookies = kmalloc(sizeof(off_t), M_TEMP, |
| 230 | M_WAITOK); |
| 231 | } |
| 232 | off = startoffset; |
| 233 | for (dp = (struct ext2_dir_entry_2 *)dirbuf, |
| 234 | cookiep = cookies, ecookies = cookies + ncookies; |
| 235 | cookiep < ecookies; |
| 236 | dp = (struct ext2_dir_entry_2 *)((caddr_t) dp + dp->rec_len)) { |
| 237 | off += dp->rec_len; |
| 238 | *cookiep++ = off; |
| 239 | } |
| 240 | *ap->a_ncookies = ncookies; |
| 241 | *ap->a_cookies = cookies; |
| 242 | } |
| 243 | } |
| 244 | kfree(dirbuf, M_TEMP); |
| 245 | if (ap->a_eofflag) |
| 246 | *ap->a_eofflag = VTOI(ap->a_vp)->i_size <= uio->uio_offset; |
| 247 | vn_unlock(ap->a_vp); |
| 248 | return (error); |
| 249 | } |
| 250 | |
| 251 | /* |
| 252 | * Convert a component of a pathname into a pointer to a locked inode. |
| 253 | * This is a very central and rather complicated routine. |
| 254 | * If the file system is not maintained in a strict tree hierarchy, |
| 255 | * this can result in a deadlock situation (see comments in code below). |
| 256 | * |
| 257 | * The cnp->cn_nameiop argument is LOOKUP, CREATE, RENAME, or DELETE depending |
| 258 | * on whether the name is to be looked up, created, renamed, or deleted. |
| 259 | * When CREATE, RENAME, or DELETE is specified, information usable in |
| 260 | * creating, renaming, or deleting a directory entry may be calculated. |
| 261 | * If flag has LOCKPARENT or'ed into it and the target of the pathname |
| 262 | * exists, lookup returns both the target and its parent directory locked. |
| 263 | * When creating or renaming and LOCKPARENT is specified, the target may |
| 264 | * not be ".". When deleting and LOCKPARENT is specified, the target may |
| 265 | * be "."., but the caller must check to ensure it does an vrele and vput |
| 266 | * instead of two vputs. |
| 267 | * |
| 268 | * Overall outline of ufs_lookup: |
| 269 | * |
| 270 | * search for name in directory, to found or notfound |
| 271 | * notfound: |
| 272 | * if creating, return locked directory, leaving info on available slots |
| 273 | * else return error |
| 274 | * found: |
| 275 | * if at end of path and deleting, return information to allow delete |
| 276 | * if at end of path and rewriting (RENAME and LOCKPARENT), lock target |
| 277 | * inode and return info to allow rewrite |
| 278 | * if not at end, add name to cache; if at end and neither creating |
| 279 | * nor deleting, add name to cache |
| 280 | * |
| 281 | * ext2_lookup(struct vnode *a_dvp, struct vnode **a_vpp, |
| 282 | * struct componentname *a_cnp) |
| 283 | */ |
| 284 | int |
| 285 | ext2_lookup(struct vop_old_lookup_args *ap) |
| 286 | { |
| 287 | struct vnode *vdp; /* vnode for directory being searched */ |
| 288 | struct inode *dp; /* inode for directory being searched */ |
| 289 | struct buf *bp; /* a buffer of directory entries */ |
| 290 | struct ext2_dir_entry_2 *ep; /* the current directory entry */ |
| 291 | int entryoffsetinblock; /* offset of ep in bp's buffer */ |
| 292 | enum {NONE, COMPACT, FOUND} slotstatus; |
| 293 | doff_t slotoffset; /* offset of area with free space */ |
| 294 | int slotsize; /* size of area at slotoffset */ |
| 295 | int slotfreespace; /* amount of space free in slot */ |
| 296 | int slotneeded; /* size of the entry we're seeking */ |
| 297 | int numdirpasses; /* strategy for directory search */ |
| 298 | doff_t endsearch; /* offset to end directory search */ |
| 299 | doff_t prevoff; /* prev entry dp->i_offset */ |
| 300 | struct vnode *pdp; /* saved dp during symlink work */ |
| 301 | struct vnode *tdp; /* returned by VFS_VGET */ |
| 302 | doff_t enduseful; /* pointer past last used dir slot */ |
| 303 | u_long bmask; /* block offset mask */ |
| 304 | int lockparent; /* 1 => lockparent flag is set */ |
| 305 | int wantparent; /* 1 => wantparent or lockparent flag */ |
| 306 | int namlen, error; |
| 307 | struct vnode **vpp = ap->a_vpp; |
| 308 | struct componentname *cnp = ap->a_cnp; |
| 309 | struct ucred *cred = cnp->cn_cred; |
| 310 | int flags = cnp->cn_flags; |
| 311 | int nameiop = cnp->cn_nameiop; |
| 312 | |
| 313 | int DIRBLKSIZ = VTOI(ap->a_dvp)->i_e2fs->s_blocksize; |
| 314 | |
| 315 | bp = NULL; |
| 316 | slotoffset = -1; |
| 317 | *vpp = NULL; |
| 318 | vdp = ap->a_dvp; |
| 319 | dp = VTOI(vdp); |
| 320 | lockparent = flags & CNP_LOCKPARENT; |
| 321 | wantparent = flags & (CNP_LOCKPARENT|CNP_WANTPARENT); |
| 322 | |
| 323 | /* |
| 324 | * We now have a segment name to search for, and a directory to search. |
| 325 | */ |
| 326 | |
| 327 | /* |
| 328 | * Suppress search for slots unless creating |
| 329 | * file and at end of pathname, in which case |
| 330 | * we watch for a place to put the new file in |
| 331 | * case it doesn't already exist. |
| 332 | */ |
| 333 | slotstatus = FOUND; |
| 334 | slotfreespace = slotsize = slotneeded = 0; |
| 335 | if (nameiop == NAMEI_CREATE || nameiop == NAMEI_RENAME) { |
| 336 | slotstatus = NONE; |
| 337 | slotneeded = EXT2_DIR_REC_LEN(cnp->cn_namelen); |
| 338 | /* was |
| 339 | slotneeded = (sizeof(struct direct) - MAXNAMLEN + |
| 340 | cnp->cn_namelen + 3) &~ 3; */ |
| 341 | } |
| 342 | |
| 343 | /* |
| 344 | * If there is cached information on a previous search of |
| 345 | * this directory, pick up where we last left off. |
| 346 | * We cache only lookups as these are the most common |
| 347 | * and have the greatest payoff. Caching CREATE has little |
| 348 | * benefit as it usually must search the entire directory |
| 349 | * to determine that the entry does not exist. Caching the |
| 350 | * location of the last DELETE or RENAME has not reduced |
| 351 | * profiling time and hence has been removed in the interest |
| 352 | * of simplicity. |
| 353 | */ |
| 354 | bmask = VFSTOEXT2(vdp->v_mount)->um_mountp->mnt_stat.f_iosize - 1; |
| 355 | if (nameiop != NAMEI_LOOKUP || dp->i_diroff == 0 || |
| 356 | dp->i_diroff > dp->i_size) { |
| 357 | entryoffsetinblock = 0; |
| 358 | dp->i_offset = 0; |
| 359 | numdirpasses = 1; |
| 360 | } else { |
| 361 | dp->i_offset = dp->i_diroff; |
| 362 | if ((entryoffsetinblock = dp->i_offset & bmask) && |
| 363 | (error = EXT2_BLKATOFF(vdp, (off_t)dp->i_offset, NULL, &bp))) |
| 364 | return (error); |
| 365 | numdirpasses = 2; |
| 366 | } |
| 367 | prevoff = dp->i_offset; |
| 368 | endsearch = roundup(dp->i_size, DIRBLKSIZ); |
| 369 | enduseful = 0; |
| 370 | |
| 371 | searchloop: |
| 372 | while (dp->i_offset < endsearch) { |
| 373 | /* |
| 374 | * If necessary, get the next directory block. |
| 375 | */ |
| 376 | if ((dp->i_offset & bmask) == 0) { |
| 377 | if (bp != NULL) |
| 378 | brelse(bp); |
| 379 | if ((error = |
| 380 | EXT2_BLKATOFF(vdp, (off_t)dp->i_offset, NULL, &bp)) != 0) |
| 381 | return (error); |
| 382 | entryoffsetinblock = 0; |
| 383 | } |
| 384 | /* |
| 385 | * If still looking for a slot, and at a DIRBLKSIZE |
| 386 | * boundary, have to start looking for free space again. |
| 387 | */ |
| 388 | if (slotstatus == NONE && |
| 389 | (entryoffsetinblock & (DIRBLKSIZ - 1)) == 0) { |
| 390 | slotoffset = -1; |
| 391 | slotfreespace = 0; |
| 392 | } |
| 393 | /* |
| 394 | * Get pointer to next entry. |
| 395 | * Full validation checks are slow, so we only check |
| 396 | * enough to insure forward progress through the |
| 397 | * directory. Complete checks can be run by patching |
| 398 | * "dirchk" to be true. |
| 399 | */ |
| 400 | ep = (struct ext2_dir_entry_2 *) |
| 401 | ((char *)bp->b_data + entryoffsetinblock); |
| 402 | if (ep->rec_len == 0 || |
| 403 | (dirchk && ext2_dirbadentry(vdp, ep, entryoffsetinblock))) { |
| 404 | int i; |
| 405 | ext2_dirbad(dp, dp->i_offset, "mangled entry"); |
| 406 | i = DIRBLKSIZ - (entryoffsetinblock & (DIRBLKSIZ - 1)); |
| 407 | dp->i_offset += i; |
| 408 | entryoffsetinblock += i; |
| 409 | continue; |
| 410 | } |
| 411 | |
| 412 | /* |
| 413 | * If an appropriate sized slot has not yet been found, |
| 414 | * check to see if one is available. Also accumulate space |
| 415 | * in the current block so that we can determine if |
| 416 | * compaction is viable. |
| 417 | */ |
| 418 | if (slotstatus != FOUND) { |
| 419 | int size = ep->rec_len; |
| 420 | |
| 421 | if (ep->inode != 0) |
| 422 | size -= EXT2_DIR_REC_LEN(ep->name_len); |
| 423 | if (size > 0) { |
| 424 | if (size >= slotneeded) { |
| 425 | slotstatus = FOUND; |
| 426 | slotoffset = dp->i_offset; |
| 427 | slotsize = ep->rec_len; |
| 428 | } else if (slotstatus == NONE) { |
| 429 | slotfreespace += size; |
| 430 | if (slotoffset == -1) |
| 431 | slotoffset = dp->i_offset; |
| 432 | if (slotfreespace >= slotneeded) { |
| 433 | slotstatus = COMPACT; |
| 434 | slotsize = dp->i_offset + |
| 435 | ep->rec_len - slotoffset; |
| 436 | } |
| 437 | } |
| 438 | } |
| 439 | } |
| 440 | |
| 441 | /* |
| 442 | * Check for a name match. |
| 443 | */ |
| 444 | if (ep->inode) { |
| 445 | namlen = ep->name_len; |
| 446 | if (namlen == cnp->cn_namelen && |
| 447 | !bcmp(cnp->cn_nameptr, ep->name, |
| 448 | (unsigned)namlen)) { |
| 449 | /* |
| 450 | * Save directory entry's inode number and |
| 451 | * reclen in ndp->ni_ufs area, and release |
| 452 | * directory buffer. |
| 453 | */ |
| 454 | dp->i_ino = ep->inode; |
| 455 | dp->i_reclen = ep->rec_len; |
| 456 | goto found; |
| 457 | } |
| 458 | } |
| 459 | prevoff = dp->i_offset; |
| 460 | dp->i_offset += ep->rec_len; |
| 461 | entryoffsetinblock += ep->rec_len; |
| 462 | if (ep->inode) |
| 463 | enduseful = dp->i_offset; |
| 464 | } |
| 465 | /* notfound: */ |
| 466 | /* |
| 467 | * If we started in the middle of the directory and failed |
| 468 | * to find our target, we must check the beginning as well. |
| 469 | */ |
| 470 | if (numdirpasses == 2) { |
| 471 | numdirpasses--; |
| 472 | dp->i_offset = 0; |
| 473 | endsearch = dp->i_diroff; |
| 474 | goto searchloop; |
| 475 | } |
| 476 | if (bp != NULL) |
| 477 | brelse(bp); |
| 478 | /* |
| 479 | * If creating, and at end of pathname and current |
| 480 | * directory has not been removed, then can consider |
| 481 | * allowing file to be created. |
| 482 | */ |
| 483 | if ((nameiop == NAMEI_CREATE || nameiop == NAMEI_RENAME) && |
| 484 | dp->i_nlink != 0) { |
| 485 | /* |
| 486 | * Access for write is interpreted as allowing |
| 487 | * creation of files in the directory. |
| 488 | */ |
| 489 | if ((error = VOP_EACCESS(vdp, VWRITE, cred)) != 0) |
| 490 | return (error); |
| 491 | /* |
| 492 | * Return an indication of where the new directory |
| 493 | * entry should be put. If we didn't find a slot, |
| 494 | * then set dp->i_count to 0 indicating |
| 495 | * that the new slot belongs at the end of the |
| 496 | * directory. If we found a slot, then the new entry |
| 497 | * can be put in the range from dp->i_offset to |
| 498 | * dp->i_offset + dp->i_count. |
| 499 | */ |
| 500 | if (slotstatus == NONE) { |
| 501 | dp->i_offset = roundup(dp->i_size, DIRBLKSIZ); |
| 502 | dp->i_count = 0; |
| 503 | enduseful = dp->i_offset; |
| 504 | } else { |
| 505 | dp->i_offset = slotoffset; |
| 506 | dp->i_count = slotsize; |
| 507 | if (enduseful < slotoffset + slotsize) |
| 508 | enduseful = slotoffset + slotsize; |
| 509 | } |
| 510 | dp->i_endoff = roundup(enduseful, DIRBLKSIZ); |
| 511 | dp->i_flag |= IN_CHANGE | IN_UPDATE; |
| 512 | /* |
| 513 | * We return with the directory locked, so that |
| 514 | * the parameters we set up above will still be |
| 515 | * valid if we actually decide to do a direnter(). |
| 516 | * We return ni_vp == NULL to indicate that the entry |
| 517 | * does not currently exist; we leave a pointer to |
| 518 | * the (locked) directory inode in ndp->ni_dvp. |
| 519 | * The pathname buffer is saved so that the name |
| 520 | * can be obtained later. |
| 521 | * |
| 522 | * NB - if the directory is unlocked, then this |
| 523 | * information cannot be used. |
| 524 | */ |
| 525 | if (!lockparent) |
| 526 | vn_unlock(vdp); |
| 527 | return (EJUSTRETURN); |
| 528 | } |
| 529 | return (ENOENT); |
| 530 | |
| 531 | found: |
| 532 | /* |
| 533 | * Check that directory length properly reflects presence |
| 534 | * of this entry. |
| 535 | */ |
| 536 | if (entryoffsetinblock + EXT2_DIR_REC_LEN(ep->name_len) |
| 537 | > dp->i_size) { |
| 538 | ext2_dirbad(dp, dp->i_offset, "i_size too small"); |
| 539 | dp->i_size = entryoffsetinblock+EXT2_DIR_REC_LEN(ep->name_len); |
| 540 | dp->i_flag |= IN_CHANGE | IN_UPDATE; |
| 541 | } |
| 542 | brelse(bp); |
| 543 | |
| 544 | /* |
| 545 | * Found component in pathname. |
| 546 | * If the final component of path name, save information |
| 547 | * in the cache as to where the entry was found. |
| 548 | */ |
| 549 | if (nameiop == NAMEI_LOOKUP) |
| 550 | dp->i_diroff = dp->i_offset &~ (DIRBLKSIZ - 1); |
| 551 | |
| 552 | /* |
| 553 | * If deleting, and at end of pathname, return |
| 554 | * parameters which can be used to remove file. |
| 555 | * If the wantparent flag isn't set, we return only |
| 556 | * the directory (in ndp->ni_dvp), otherwise we go |
| 557 | * on and lock the inode, being careful with ".". |
| 558 | */ |
| 559 | if (nameiop == NAMEI_DELETE) { |
| 560 | /* |
| 561 | * Write access to directory required to delete files. |
| 562 | */ |
| 563 | if ((error = VOP_EACCESS(vdp, VWRITE, cred)) != 0) |
| 564 | return (error); |
| 565 | /* |
| 566 | * Return pointer to current entry in dp->i_offset, |
| 567 | * and distance past previous entry (if there |
| 568 | * is a previous entry in this block) in dp->i_count. |
| 569 | * Save directory inode pointer in ndp->ni_dvp for dirremove(). |
| 570 | */ |
| 571 | if ((dp->i_offset & (DIRBLKSIZ - 1)) == 0) |
| 572 | dp->i_count = 0; |
| 573 | else |
| 574 | dp->i_count = dp->i_offset - prevoff; |
| 575 | if (dp->i_number == dp->i_ino) { |
| 576 | vref(vdp); |
| 577 | *vpp = vdp; |
| 578 | return (0); |
| 579 | } |
| 580 | if ((error = VFS_VGET(vdp->v_mount, NULL, dp->i_ino, &tdp)) != 0) |
| 581 | return (error); |
| 582 | /* |
| 583 | * If directory is "sticky", then user must own |
| 584 | * the directory, or the file in it, else she |
| 585 | * may not delete it (unless she's root). This |
| 586 | * implements append-only directories. |
| 587 | */ |
| 588 | if ((dp->i_mode & ISVTX) && |
| 589 | cred->cr_uid != 0 && |
| 590 | cred->cr_uid != dp->i_uid && |
| 591 | VTOI(tdp)->i_uid != cred->cr_uid) { |
| 592 | vput(tdp); |
| 593 | return (EPERM); |
| 594 | } |
| 595 | *vpp = tdp; |
| 596 | if (!lockparent) |
| 597 | vn_unlock(vdp); |
| 598 | return (0); |
| 599 | } |
| 600 | |
| 601 | /* |
| 602 | * If rewriting (RENAME), return the inode and the |
| 603 | * information required to rewrite the present directory |
| 604 | * Must get inode of directory entry to verify it's a |
| 605 | * regular file, or empty directory. |
| 606 | */ |
| 607 | if (nameiop == NAMEI_RENAME && wantparent) { |
| 608 | if ((error = VOP_EACCESS(vdp, VWRITE, cred)) != 0) |
| 609 | return (error); |
| 610 | /* |
| 611 | * Careful about locking second inode. |
| 612 | * This can only occur if the target is ".". |
| 613 | */ |
| 614 | if (dp->i_number == dp->i_ino) |
| 615 | return (EISDIR); |
| 616 | if ((error = VFS_VGET(vdp->v_mount, NULL, dp->i_ino, &tdp)) != 0) |
| 617 | return (error); |
| 618 | *vpp = tdp; |
| 619 | if (!lockparent) |
| 620 | vn_unlock(vdp); |
| 621 | return (0); |
| 622 | } |
| 623 | |
| 624 | /* |
| 625 | * Step through the translation in the name. We do not `vput' the |
| 626 | * directory because we may need it again if a symbolic link |
| 627 | * is relative to the current directory. Instead we save it |
| 628 | * unlocked as "pdp". We must get the target inode before unlocking |
| 629 | * the directory to insure that the inode will not be removed |
| 630 | * before we get it. We prevent deadlock by always fetching |
| 631 | * inodes from the root, moving down the directory tree. Thus |
| 632 | * when following backward pointers ".." we must unlock the |
| 633 | * parent directory before getting the requested directory. |
| 634 | * There is a potential race condition here if both the current |
| 635 | * and parent directories are removed before the VFS_VGET for the |
| 636 | * inode associated with ".." returns. We hope that this occurs |
| 637 | * infrequently since we cannot avoid this race condition without |
| 638 | * implementing a sophisticated deadlock detection algorithm. |
| 639 | * Note also that this simple deadlock detection scheme will not |
| 640 | * work if the file system has any hard links other than ".." |
| 641 | * that point backwards in the directory structure. |
| 642 | */ |
| 643 | pdp = vdp; |
| 644 | if (flags & CNP_ISDOTDOT) { |
| 645 | vn_unlock(pdp); /* race to get the inode */ |
| 646 | if ((error = VFS_VGET(vdp->v_mount, NULL, dp->i_ino, &tdp)) != 0) { |
| 647 | vn_lock(pdp, LK_EXCLUSIVE | LK_RETRY); |
| 648 | return (error); |
| 649 | } |
| 650 | if (lockparent && (error = vn_lock(pdp, LK_EXCLUSIVE))) { |
| 651 | vput(tdp); |
| 652 | return (error); |
| 653 | } |
| 654 | *vpp = tdp; |
| 655 | } else if (dp->i_number == dp->i_ino) { |
| 656 | vref(vdp); /* we want ourself, ie "." */ |
| 657 | *vpp = vdp; |
| 658 | } else { |
| 659 | if ((error = VFS_VGET(vdp->v_mount, NULL, dp->i_ino, &tdp)) != 0) |
| 660 | return (error); |
| 661 | if (!lockparent) { |
| 662 | vn_unlock(pdp); |
| 663 | cnp->cn_flags |= CNP_PDIRUNLOCK; |
| 664 | } |
| 665 | *vpp = tdp; |
| 666 | } |
| 667 | return (0); |
| 668 | } |
| 669 | |
| 670 | void |
| 671 | ext2_dirbad(struct inode *ip, doff_t offset, char *how) |
| 672 | { |
| 673 | struct mount *mp; |
| 674 | |
| 675 | mp = ITOV(ip)->v_mount; |
| 676 | kprintf("%s: bad dir ino %lu at offset %ld: %s\n", |
| 677 | mp->mnt_stat.f_mntfromname, (u_long)ip->i_number, |
| 678 | (long)offset, how); |
| 679 | if ((mp->mnt_flag & MNT_RDONLY) == 0) |
| 680 | panic("ufs_dirbad: bad dir"); |
| 681 | } |
| 682 | |
| 683 | /* |
| 684 | * Do consistency checking on a directory entry: |
| 685 | * record length must be multiple of 4 |
| 686 | * entry must fit in rest of its DIRBLKSIZ block |
| 687 | * record must be large enough to contain entry |
| 688 | * name is not longer than MAXNAMLEN |
| 689 | * name must be as long as advertised, and null terminated |
| 690 | */ |
| 691 | /* |
| 692 | * changed so that it confirms to ext2_check_dir_entry |
| 693 | */ |
| 694 | static int |
| 695 | ext2_dirbadentry(struct vnode *dp, struct ext2_dir_entry_2 *de, |
| 696 | int entryoffsetinblock) |
| 697 | { |
| 698 | int DIRBLKSIZ = VTOI(dp)->i_e2fs->s_blocksize; |
| 699 | |
| 700 | char * error_msg = NULL; |
| 701 | |
| 702 | if (de->rec_len < EXT2_DIR_REC_LEN(1)) |
| 703 | error_msg = "rec_len is smaller than minimal"; |
| 704 | else if (de->rec_len % 4 != 0) |
| 705 | error_msg = "rec_len % 4 != 0"; |
| 706 | else if (de->rec_len < EXT2_DIR_REC_LEN(de->name_len)) |
| 707 | error_msg = "reclen is too small for name_len"; |
| 708 | else if (entryoffsetinblock + de->rec_len > DIRBLKSIZ) |
| 709 | error_msg = "directory entry across blocks"; |
| 710 | /* else LATER |
| 711 | if (de->inode > dir->i_sb->u.ext2_sb.s_es->s_inodes_count) |
| 712 | error_msg = "inode out of bounds"; |
| 713 | */ |
| 714 | |
| 715 | if (error_msg != NULL) { |
| 716 | kprintf("bad directory entry: %s\n", error_msg); |
| 717 | kprintf("offset=%d, inode=%lu, rec_len=%u, name_len=%u\n", |
| 718 | entryoffsetinblock, (unsigned long)de->inode, |
| 719 | de->rec_len, de->name_len); |
| 720 | } |
| 721 | return error_msg == NULL ? 0 : 1; |
| 722 | } |
| 723 | |
| 724 | /* |
| 725 | * Write a directory entry after a call to namei, using the parameters |
| 726 | * that it left in the directory inode. The argument ip is the inode which |
| 727 | * the new directory entry will refer to. Dvp is a pointer to the directory |
| 728 | * to be written, which was left locked by namei. Remaining parameters |
| 729 | * (dp->i_offset, dp->i_count) indicate how the space for the new |
| 730 | * entry is to be obtained. |
| 731 | */ |
| 732 | int |
| 733 | ext2_direnter(struct inode *ip, struct vnode *dvp, struct componentname *cnp) |
| 734 | { |
| 735 | struct ext2_dir_entry_2 *ep, *nep; |
| 736 | struct inode *dp; |
| 737 | struct buf *bp; |
| 738 | struct ext2_dir_entry_2 newdir; |
| 739 | struct iovec aiov; |
| 740 | struct uio auio; |
| 741 | u_int dsize; |
| 742 | int error, loc, newentrysize, spacefree; |
| 743 | char *dirbuf; |
| 744 | int DIRBLKSIZ = ip->i_e2fs->s_blocksize; |
| 745 | |
| 746 | |
| 747 | dp = VTOI(dvp); |
| 748 | newdir.inode = ip->i_number; |
| 749 | newdir.name_len = cnp->cn_namelen; |
| 750 | if (EXT2_HAS_INCOMPAT_FEATURE(ip->i_e2fs->s_es, |
| 751 | EXT2_FEATURE_INCOMPAT_FILETYPE)) |
| 752 | newdir.file_type = DTTOFT(IFTODT(ip->i_mode)); |
| 753 | else |
| 754 | newdir.file_type = EXT2_FT_UNKNOWN; |
| 755 | bcopy(cnp->cn_nameptr, newdir.name, (unsigned)cnp->cn_namelen + 1); |
| 756 | newentrysize = EXT2_DIR_REC_LEN(newdir.name_len); |
| 757 | if (dp->i_count == 0) { |
| 758 | /* |
| 759 | * If dp->i_count is 0, then namei could find no |
| 760 | * space in the directory. Here, dp->i_offset will |
| 761 | * be on a directory block boundary and we will write the |
| 762 | * new entry into a fresh block. |
| 763 | */ |
| 764 | if (dp->i_offset & (DIRBLKSIZ - 1)) |
| 765 | panic("ext2_direnter: newblk"); |
| 766 | auio.uio_offset = dp->i_offset; |
| 767 | newdir.rec_len = DIRBLKSIZ; |
| 768 | auio.uio_resid = newentrysize; |
| 769 | aiov.iov_len = newentrysize; |
| 770 | aiov.iov_base = (caddr_t)&newdir; |
| 771 | auio.uio_iov = &aiov; |
| 772 | auio.uio_iovcnt = 1; |
| 773 | auio.uio_rw = UIO_WRITE; |
| 774 | auio.uio_segflg = UIO_SYSSPACE; |
| 775 | auio.uio_td = NULL; |
| 776 | error = VOP_WRITE(dvp, &auio, IO_SYNC, cnp->cn_cred); |
| 777 | if (DIRBLKSIZ > |
| 778 | VFSTOEXT2(dvp->v_mount)->um_mountp->mnt_stat.f_bsize) |
| 779 | /* XXX should grow with balloc() */ |
| 780 | panic("ext2_direnter: frag size"); |
| 781 | else if (!error) { |
| 782 | dp->i_size = roundup(dp->i_size, DIRBLKSIZ); |
| 783 | dp->i_flag |= IN_CHANGE; |
| 784 | } |
| 785 | return (error); |
| 786 | } |
| 787 | |
| 788 | /* |
| 789 | * If dp->i_count is non-zero, then namei found space |
| 790 | * for the new entry in the range dp->i_offset to |
| 791 | * dp->i_offset + dp->i_count in the directory. |
| 792 | * To use this space, we may have to compact the entries located |
| 793 | * there, by copying them together towards the beginning of the |
| 794 | * block, leaving the free space in one usable chunk at the end. |
| 795 | */ |
| 796 | |
| 797 | /* |
| 798 | * Increase size of directory if entry eats into new space. |
| 799 | * This should never push the size past a new multiple of |
| 800 | * DIRBLKSIZE. |
| 801 | * |
| 802 | * N.B. - THIS IS AN ARTIFACT OF 4.2 AND SHOULD NEVER HAPPEN. |
| 803 | */ |
| 804 | if (dp->i_offset + dp->i_count > dp->i_size) |
| 805 | dp->i_size = dp->i_offset + dp->i_count; |
| 806 | /* |
| 807 | * Get the block containing the space for the new directory entry. |
| 808 | */ |
| 809 | if ((error = EXT2_BLKATOFF(dvp, (off_t)dp->i_offset, &dirbuf, &bp)) != 0) |
| 810 | return (error); |
| 811 | /* |
| 812 | * Find space for the new entry. In the simple case, the entry at |
| 813 | * offset base will have the space. If it does not, then namei |
| 814 | * arranged that compacting the region dp->i_offset to |
| 815 | * dp->i_offset + dp->i_count would yield the |
| 816 | * space. |
| 817 | */ |
| 818 | ep = (struct ext2_dir_entry_2 *)dirbuf; |
| 819 | dsize = EXT2_DIR_REC_LEN(ep->name_len); |
| 820 | spacefree = ep->rec_len - dsize; |
| 821 | for (loc = ep->rec_len; loc < dp->i_count; ) { |
| 822 | nep = (struct ext2_dir_entry_2 *)(dirbuf + loc); |
| 823 | if (ep->inode) { |
| 824 | /* trim the existing slot */ |
| 825 | ep->rec_len = dsize; |
| 826 | ep = (struct ext2_dir_entry_2 *)((char *)ep + dsize); |
| 827 | } else { |
| 828 | /* overwrite; nothing there; header is ours */ |
| 829 | spacefree += dsize; |
| 830 | } |
| 831 | dsize = EXT2_DIR_REC_LEN(nep->name_len); |
| 832 | spacefree += nep->rec_len - dsize; |
| 833 | loc += nep->rec_len; |
| 834 | bcopy((caddr_t)nep, (caddr_t)ep, dsize); |
| 835 | } |
| 836 | /* |
| 837 | * Update the pointer fields in the previous entry (if any), |
| 838 | * copy in the new entry, and write out the block. |
| 839 | */ |
| 840 | if (ep->inode == 0) { |
| 841 | if (spacefree + dsize < newentrysize) |
| 842 | panic("ext2_direnter: compact1"); |
| 843 | newdir.rec_len = spacefree + dsize; |
| 844 | } else { |
| 845 | if (spacefree < newentrysize) |
| 846 | panic("ext2_direnter: compact2"); |
| 847 | newdir.rec_len = spacefree; |
| 848 | ep->rec_len = dsize; |
| 849 | ep = (struct ext2_dir_entry_2 *)((char *)ep + dsize); |
| 850 | } |
| 851 | bcopy((caddr_t)&newdir, (caddr_t)ep, (u_int)newentrysize); |
| 852 | error = bwrite(bp); |
| 853 | dp->i_flag |= IN_CHANGE | IN_UPDATE; |
| 854 | if (!error && dp->i_endoff && dp->i_endoff < dp->i_size) |
| 855 | error = EXT2_TRUNCATE(dvp, (off_t)dp->i_endoff, IO_SYNC, |
| 856 | cnp->cn_cred); |
| 857 | return (error); |
| 858 | } |
| 859 | |
| 860 | /* |
| 861 | * Remove a directory entry after a call to namei, using |
| 862 | * the parameters which it left in the directory inode. The entry |
| 863 | * dp->i_offset contains the offset into the directory of the |
| 864 | * entry to be eliminated. The dp->i_count field contains the |
| 865 | * size of the previous record in the directory. If this |
| 866 | * is 0, the first entry is being deleted, so we need only |
| 867 | * zero the inode number to mark the entry as free. If the |
| 868 | * entry is not the first in the directory, we must reclaim |
| 869 | * the space of the now empty record by adding the record size |
| 870 | * to the size of the previous entry. |
| 871 | */ |
| 872 | int |
| 873 | ext2_dirremove(struct vnode *dvp, struct componentname *cnp) |
| 874 | { |
| 875 | struct inode *dp; |
| 876 | struct ext2_dir_entry_2 *ep; |
| 877 | struct buf *bp; |
| 878 | int error; |
| 879 | |
| 880 | dp = VTOI(dvp); |
| 881 | if (dp->i_count == 0) { |
| 882 | /* |
| 883 | * First entry in block: set d_ino to zero. |
| 884 | */ |
| 885 | if ((error = |
| 886 | EXT2_BLKATOFF(dvp, (off_t)dp->i_offset, (char **)&ep, &bp)) != 0) |
| 887 | return (error); |
| 888 | ep->inode = 0; |
| 889 | error = bwrite(bp); |
| 890 | dp->i_flag |= IN_CHANGE | IN_UPDATE; |
| 891 | return (error); |
| 892 | } |
| 893 | /* |
| 894 | * Collapse new free space into previous entry. |
| 895 | */ |
| 896 | if ((error = EXT2_BLKATOFF(dvp, (off_t)(dp->i_offset - dp->i_count), |
| 897 | (char **)&ep, &bp)) != 0) |
| 898 | return (error); |
| 899 | ep->rec_len += dp->i_reclen; |
| 900 | error = bwrite(bp); |
| 901 | dp->i_flag |= IN_CHANGE | IN_UPDATE; |
| 902 | return (error); |
| 903 | } |
| 904 | |
| 905 | /* |
| 906 | * Rewrite an existing directory entry to point at the inode |
| 907 | * supplied. The parameters describing the directory entry are |
| 908 | * set up by a call to namei. |
| 909 | */ |
| 910 | int |
| 911 | ext2_dirrewrite(struct inode *dp, struct inode *ip, struct componentname *cnp) |
| 912 | { |
| 913 | struct buf *bp; |
| 914 | struct ext2_dir_entry_2 *ep; |
| 915 | struct vnode *vdp = ITOV(dp); |
| 916 | int error; |
| 917 | |
| 918 | if ((error = EXT2_BLKATOFF(vdp, (off_t)dp->i_offset, (char **)&ep, &bp)) != 0) |
| 919 | return (error); |
| 920 | ep->inode = ip->i_number; |
| 921 | if (EXT2_HAS_INCOMPAT_FEATURE(ip->i_e2fs->s_es, |
| 922 | EXT2_FEATURE_INCOMPAT_FILETYPE)) |
| 923 | ep->file_type = DTTOFT(IFTODT(ip->i_mode)); |
| 924 | else |
| 925 | ep->file_type = EXT2_FT_UNKNOWN; |
| 926 | error = bwrite(bp); |
| 927 | dp->i_flag |= IN_CHANGE | IN_UPDATE; |
| 928 | return (error); |
| 929 | } |
| 930 | |
| 931 | /* |
| 932 | * Check if a directory is empty or not. |
| 933 | * Inode supplied must be locked. |
| 934 | * |
| 935 | * Using a struct dirtemplate here is not precisely |
| 936 | * what we want, but better than using a struct direct. |
| 937 | * |
| 938 | * NB: does not handle corrupted directories. |
| 939 | */ |
| 940 | int |
| 941 | ext2_dirempty(struct inode *ip, ino_t parentino, struct ucred *cred) |
| 942 | { |
| 943 | off_t off; |
| 944 | struct dirtemplate dbuf; |
| 945 | struct ext2_dir_entry_2 *dp = (struct ext2_dir_entry_2 *)&dbuf; |
| 946 | int error, count, namlen; |
| 947 | |
| 948 | #define MINDIRSIZ (sizeof (struct dirtemplate) / 2) |
| 949 | |
| 950 | for (off = 0; off < ip->i_size; off += dp->rec_len) { |
| 951 | error = vn_rdwr(UIO_READ, ITOV(ip), (caddr_t)dp, MINDIRSIZ, off, |
| 952 | UIO_SYSSPACE, IO_NODELOCKED, cred, &count); |
| 953 | /* |
| 954 | * Since we read MINDIRSIZ, residual must |
| 955 | * be 0 unless we're at end of file. |
| 956 | */ |
| 957 | if (error || count != 0) |
| 958 | return (0); |
| 959 | /* avoid infinite loops */ |
| 960 | if (dp->rec_len == 0) |
| 961 | return (0); |
| 962 | /* skip empty entries */ |
| 963 | if (dp->inode == 0) |
| 964 | continue; |
| 965 | /* accept only "." and ".." */ |
| 966 | namlen = dp->name_len; |
| 967 | if (namlen > 2) |
| 968 | return (0); |
| 969 | if (dp->name[0] != '.') |
| 970 | return (0); |
| 971 | /* |
| 972 | * At this point namlen must be 1 or 2. |
| 973 | * 1 implies ".", 2 implies ".." if second |
| 974 | * char is also "." |
| 975 | */ |
| 976 | if (namlen == 1) |
| 977 | continue; |
| 978 | if (dp->name[1] == '.' && dp->inode == parentino) |
| 979 | continue; |
| 980 | return (0); |
| 981 | } |
| 982 | return (1); |
| 983 | } |
| 984 | |
| 985 | /* |
| 986 | * Check if source directory is in the path of the target directory. |
| 987 | * Target is supplied locked, source is unlocked. |
| 988 | * The target is always vput before returning. |
| 989 | */ |
| 990 | int |
| 991 | ext2_checkpath(struct inode *source, struct inode *target, struct ucred *cred) |
| 992 | { |
| 993 | struct vnode *vp; |
| 994 | int error, rootino, namlen; |
| 995 | struct dirtemplate dirbuf; |
| 996 | |
| 997 | vp = ITOV(target); |
| 998 | if (target->i_number == source->i_number) { |
| 999 | error = EEXIST; |
| 1000 | goto out; |
| 1001 | } |
| 1002 | rootino = ROOTINO; |
| 1003 | error = 0; |
| 1004 | if (target->i_number == rootino) |
| 1005 | goto out; |
| 1006 | |
| 1007 | for (;;) { |
| 1008 | if (vp->v_type != VDIR) { |
| 1009 | error = ENOTDIR; |
| 1010 | break; |
| 1011 | } |
| 1012 | error = vn_rdwr(UIO_READ, vp, (caddr_t)&dirbuf, |
| 1013 | sizeof (struct dirtemplate), (off_t)0, |
| 1014 | UIO_SYSSPACE, IO_NODELOCKED, cred, NULL); |
| 1015 | if (error != 0) |
| 1016 | break; |
| 1017 | namlen = dirbuf.dotdot_type; /* like ufs little-endian */ |
| 1018 | if (namlen != 2 || |
| 1019 | dirbuf.dotdot_name[0] != '.' || |
| 1020 | dirbuf.dotdot_name[1] != '.') { |
| 1021 | error = ENOTDIR; |
| 1022 | break; |
| 1023 | } |
| 1024 | if (dirbuf.dotdot_ino == source->i_number) { |
| 1025 | error = EINVAL; |
| 1026 | break; |
| 1027 | } |
| 1028 | if (dirbuf.dotdot_ino == rootino) |
| 1029 | break; |
| 1030 | vput(vp); |
| 1031 | if ((error = VFS_VGET(vp->v_mount, NULL, dirbuf.dotdot_ino, &vp)) != 0) { |
| 1032 | vp = NULL; |
| 1033 | break; |
| 1034 | } |
| 1035 | } |
| 1036 | |
| 1037 | out: |
| 1038 | if (error == ENOTDIR) |
| 1039 | kprintf("checkpath: .. not a directory\n"); |
| 1040 | if (vp != NULL) |
| 1041 | vput(vp); |
| 1042 | return (error); |
| 1043 | } |