1 /*-
2 * modified for Lites 1.1
3 *
4 * Aug 1995, Godmar Back ([email protected])
5 * University of Utah, Department of Computer Science
6 */
7 /*-
8 * SPDX-License-Identifier: BSD-3-Clause
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. Neither the name of the University nor the names of its contributors
27 * may be used to endorse or promote products derived from this software
28 * without specific prior written permission.
29 *
30 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
31 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
32 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
33 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
34 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
35 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
36 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
37 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
38 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
39 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
40 * SUCH DAMAGE.
41 *
42 * @(#)ufs_lookup.c 8.6 (Berkeley) 4/1/94
43 */
44
45 #include <sys/param.h>
46 #include <sys/systm.h>
47 #include <sys/namei.h>
48 #include <sys/bio.h>
49 #include <sys/buf.h>
50 #include <sys/endian.h>
51 #include <sys/mount.h>
52 #include <sys/vnode.h>
53 #include <sys/malloc.h>
54 #include <sys/dirent.h>
55 #include <sys/sdt.h>
56 #include <sys/sysctl.h>
57
58 #include <ufs/ufs/dir.h>
59
60 #include <fs/ext2fs/fs.h>
61 #include <fs/ext2fs/inode.h>
62 #include <fs/ext2fs/ext2_mount.h>
63 #include <fs/ext2fs/ext2fs.h>
64 #include <fs/ext2fs/ext2_dinode.h>
65 #include <fs/ext2fs/ext2_dir.h>
66 #include <fs/ext2fs/ext2_extern.h>
67 #include <fs/ext2fs/fs.h>
68
69 SDT_PROVIDER_DECLARE(ext2fs);
70 /*
71 * ext2fs trace probe:
72 * arg0: verbosity. Higher numbers give more verbose messages
73 * arg1: Textual message
74 */
75 SDT_PROBE_DEFINE2(ext2fs, , lookup, trace, "int", "char*");
76 SDT_PROBE_DEFINE4(ext2fs, , trace, ext2_dirbad_error,
77 "char*", "ino_t", "doff_t", "char*");
78 SDT_PROBE_DEFINE5(ext2fs, , trace, ext2_dirbadentry_error,
79 "char*", "int", "uint32_t", "uint16_t", "uint8_t");
80
81 static SYSCTL_NODE(_vfs, OID_AUTO, e2fs, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
82 "EXT2FS filesystem");
83
84 /*
85 DIRBLKSIZE in ffs is DEV_BSIZE (in most cases 512)
86 while it is the native blocksize in ext2fs - thus, a #define
87 is no longer appropriate
88 */
89 #undef DIRBLKSIZ
90
91 static u_char ext2_ft_to_dt[] = {
92 DT_UNKNOWN, /* EXT2_FT_UNKNOWN */
93 DT_REG, /* EXT2_FT_REG_FILE */
94 DT_DIR, /* EXT2_FT_DIR */
95 DT_CHR, /* EXT2_FT_CHRDEV */
96 DT_BLK, /* EXT2_FT_BLKDEV */
97 DT_FIFO, /* EXT2_FT_FIFO */
98 DT_SOCK, /* EXT2_FT_SOCK */
99 DT_LNK, /* EXT2_FT_SYMLINK */
100 };
101 #define FTTODT(ft) \
102 ((ft) < nitems(ext2_ft_to_dt) ? ext2_ft_to_dt[(ft)] : DT_UNKNOWN)
103
104 static u_char dt_to_ext2_ft[] = {
105 EXT2_FT_UNKNOWN, /* DT_UNKNOWN */
106 EXT2_FT_FIFO, /* DT_FIFO */
107 EXT2_FT_CHRDEV, /* DT_CHR */
108 EXT2_FT_UNKNOWN, /* unused */
109 EXT2_FT_DIR, /* DT_DIR */
110 EXT2_FT_UNKNOWN, /* unused */
111 EXT2_FT_BLKDEV, /* DT_BLK */
112 EXT2_FT_UNKNOWN, /* unused */
113 EXT2_FT_REG_FILE, /* DT_REG */
114 EXT2_FT_UNKNOWN, /* unused */
115 EXT2_FT_SYMLINK, /* DT_LNK */
116 EXT2_FT_UNKNOWN, /* unused */
117 EXT2_FT_SOCK, /* DT_SOCK */
118 EXT2_FT_UNKNOWN, /* unused */
119 EXT2_FT_UNKNOWN, /* DT_WHT */
120 };
121 #define DTTOFT(dt) \
122 ((dt) < nitems(dt_to_ext2_ft) ? dt_to_ext2_ft[(dt)] : EXT2_FT_UNKNOWN)
123
124 static int ext2_check_direntry(struct vnode *dp,
125 struct ext2fs_direct_2 *de, int entryoffsetinblock);
126 static int ext2_is_dot_entry(struct componentname *cnp);
127 static int ext2_lookup_ino(struct vnode *vdp, struct vnode **vpp,
128 struct componentname *cnp, ino_t *dd_ino);
129
130 static int
ext2_is_dot_entry(struct componentname * cnp)131 ext2_is_dot_entry(struct componentname *cnp)
132 {
133 if (cnp->cn_namelen <= 2 && cnp->cn_nameptr[0] == '.' &&
134 (cnp->cn_nameptr[1] == '.' || cnp->cn_nameptr[1] == '\0'))
135 return (1);
136 return (0);
137 }
138
139 /*
140 * Vnode op for reading directories.
141 */
142 int
ext2_readdir(struct vop_readdir_args * ap)143 ext2_readdir(struct vop_readdir_args *ap)
144 {
145 struct vnode *vp = ap->a_vp;
146 struct uio *uio = ap->a_uio;
147 struct buf *bp;
148 struct inode *ip;
149 struct ext2fs_direct_2 *dp, *edp;
150 uint64_t *cookies;
151 struct dirent dstdp;
152 off_t offset, startoffset;
153 size_t readcnt, skipcnt;
154 ssize_t startresid;
155 u_int ncookies;
156 int DIRBLKSIZ = VTOI(ap->a_vp)->i_e2fs->e2fs_bsize;
157 int error;
158
159 if (uio->uio_offset < 0)
160 return (EINVAL);
161 ip = VTOI(vp);
162 if (ap->a_ncookies != NULL) {
163 if (uio->uio_resid < 0)
164 ncookies = 0;
165 else
166 ncookies = uio->uio_resid;
167 if (uio->uio_offset >= ip->i_size)
168 ncookies = 0;
169 else if (ip->i_size - uio->uio_offset < ncookies)
170 ncookies = ip->i_size - uio->uio_offset;
171 ncookies = ncookies / (offsetof(struct ext2fs_direct_2,
172 e2d_namlen) + 4) + 1;
173 cookies = malloc(ncookies * sizeof(*cookies), M_TEMP, M_WAITOK);
174 *ap->a_ncookies = ncookies;
175 *ap->a_cookies = cookies;
176 } else {
177 ncookies = 0;
178 cookies = NULL;
179 }
180 offset = startoffset = uio->uio_offset;
181 startresid = uio->uio_resid;
182 error = 0;
183 while (error == 0 && uio->uio_resid > 0 &&
184 uio->uio_offset < ip->i_size) {
185 error = ext2_blkatoff(vp, uio->uio_offset, NULL, &bp);
186 if (error)
187 break;
188 if (bp->b_offset + bp->b_bcount > ip->i_size)
189 readcnt = ip->i_size - bp->b_offset;
190 else
191 readcnt = bp->b_bcount;
192 skipcnt = (size_t)(uio->uio_offset - bp->b_offset) &
193 ~(size_t)(DIRBLKSIZ - 1);
194 offset = bp->b_offset + skipcnt;
195 dp = (struct ext2fs_direct_2 *)&bp->b_data[skipcnt];
196 edp = (struct ext2fs_direct_2 *)&bp->b_data[readcnt];
197 while (error == 0 && uio->uio_resid > 0 && dp < edp) {
198 if (le16toh(dp->e2d_reclen) <= offsetof(struct ext2fs_direct_2,
199 e2d_namlen) || (caddr_t)dp + le16toh(dp->e2d_reclen) >
200 (caddr_t)edp) {
201 error = EIO;
202 break;
203 }
204 /*-
205 * "New" ext2fs directory entries differ in 3 ways
206 * from ufs on-disk ones:
207 * - the name is not necessarily NUL-terminated.
208 * - the file type field always exists and always
209 * follows the name length field.
210 * - the file type is encoded in a different way.
211 *
212 * "Old" ext2fs directory entries need no special
213 * conversions, since they are binary compatible
214 * with "new" entries having a file type of 0 (i.e.,
215 * EXT2_FT_UNKNOWN). Splitting the old name length
216 * field didn't make a mess like it did in ufs,
217 * because ext2fs uses a machine-independent disk
218 * layout.
219 */
220 dstdp.d_namlen = dp->e2d_namlen;
221 dstdp.d_type = FTTODT(dp->e2d_type);
222 if (offsetof(struct ext2fs_direct_2, e2d_namlen) +
223 dstdp.d_namlen > le16toh(dp->e2d_reclen)) {
224 error = EIO;
225 break;
226 }
227 if (offset < startoffset || le32toh(dp->e2d_ino) == 0)
228 goto nextentry;
229 dstdp.d_fileno = le32toh(dp->e2d_ino);
230 dstdp.d_reclen = GENERIC_DIRSIZ(&dstdp);
231 bcopy(dp->e2d_name, dstdp.d_name, dstdp.d_namlen);
232 /* NOTE: d_off is the offset of the *next* entry. */
233 dstdp.d_off = offset + le16toh(dp->e2d_reclen);
234 dirent_terminate(&dstdp);
235 if (dstdp.d_reclen > uio->uio_resid) {
236 if (uio->uio_resid == startresid)
237 error = EINVAL;
238 else
239 error = EJUSTRETURN;
240 break;
241 }
242 /* Advance dp. */
243 error = uiomove((caddr_t)&dstdp, dstdp.d_reclen, uio);
244 if (error)
245 break;
246 if (cookies != NULL) {
247 KASSERT(ncookies > 0,
248 ("ext2_readdir: cookies buffer too small"));
249 *cookies = offset + le16toh(dp->e2d_reclen);
250 cookies++;
251 ncookies--;
252 }
253 nextentry:
254 offset += le16toh(dp->e2d_reclen);
255 dp = (struct ext2fs_direct_2 *)((caddr_t)dp +
256 le16toh(dp->e2d_reclen));
257 }
258 bqrelse(bp);
259 uio->uio_offset = offset;
260 }
261 /* We need to correct uio_offset. */
262 uio->uio_offset = offset;
263 if (error == EJUSTRETURN)
264 error = 0;
265 if (ap->a_ncookies != NULL) {
266 if (error == 0) {
267 *ap->a_ncookies -= ncookies;
268 } else {
269 free(*ap->a_cookies, M_TEMP);
270 *ap->a_ncookies = 0;
271 *ap->a_cookies = NULL;
272 }
273 }
274 if (error == 0 && ap->a_eofflag)
275 *ap->a_eofflag = ip->i_size <= uio->uio_offset;
276 return (error);
277 }
278
279 /*
280 * Convert a component of a pathname into a pointer to a locked inode.
281 * This is a very central and rather complicated routine.
282 * If the file system is not maintained in a strict tree hierarchy,
283 * this can result in a deadlock situation (see comments in code below).
284 *
285 * The cnp->cn_nameiop argument is LOOKUP, CREATE, RENAME, or DELETE depending
286 * on whether the name is to be looked up, created, renamed, or deleted.
287 * When CREATE, RENAME, or DELETE is specified, information usable in
288 * creating, renaming, or deleting a directory entry may be calculated.
289 * If flag has LOCKPARENT or'ed into it and the target of the pathname
290 * exists, lookup returns both the target and its parent directory locked.
291 * When creating or renaming and LOCKPARENT is specified, the target may
292 * not be ".". When deleting and LOCKPARENT is specified, the target may
293 * be "."., but the caller must check to ensure it does an vrele and vput
294 * instead of two vputs.
295 *
296 * Overall outline of ext2_lookup:
297 *
298 * search for name in directory, to found or notfound
299 * notfound:
300 * if creating, return locked directory, leaving info on available slots
301 * else return error
302 * found:
303 * if at end of path and deleting, return information to allow delete
304 * if at end of path and rewriting (RENAME and LOCKPARENT), lock target
305 * inode and return info to allow rewrite
306 * if not at end, add name to cache; if at end and neither creating
307 * nor deleting, add name to cache
308 */
309 int
ext2_lookup(struct vop_cachedlookup_args * ap)310 ext2_lookup(struct vop_cachedlookup_args *ap)
311 {
312
313 return (ext2_lookup_ino(ap->a_dvp, ap->a_vpp, ap->a_cnp, NULL));
314 }
315
316 static int
ext2_lookup_ino(struct vnode * vdp,struct vnode ** vpp,struct componentname * cnp,ino_t * dd_ino)317 ext2_lookup_ino(struct vnode *vdp, struct vnode **vpp, struct componentname *cnp,
318 ino_t *dd_ino)
319 {
320 struct inode *dp; /* inode for directory being searched */
321 struct buf *bp; /* a buffer of directory entries */
322 struct ext2fs_direct_2 *ep; /* the current directory entry */
323 int entryoffsetinblock; /* offset of ep in bp's buffer */
324 struct ext2fs_searchslot ss;
325 doff_t i_diroff; /* cached i_diroff value */
326 doff_t i_offset; /* cached i_offset value */
327 int numdirpasses; /* strategy for directory search */
328 doff_t endsearch; /* offset to end directory search */
329 doff_t prevoff; /* prev entry dp->i_offset */
330 struct vnode *pdp; /* saved dp during symlink work */
331 struct vnode *tdp; /* returned by VFS_VGET */
332 doff_t enduseful; /* pointer past last used dir slot */
333 u_long bmask; /* block offset mask */
334 int error;
335 struct ucred *cred = cnp->cn_cred;
336 int flags = cnp->cn_flags;
337 int nameiop = cnp->cn_nameiop;
338 ino_t ino, ino1;
339 int ltype;
340 int entry_found = 0;
341
342 int DIRBLKSIZ = VTOI(vdp)->i_e2fs->e2fs_bsize;
343
344 if (vpp != NULL)
345 *vpp = NULL;
346
347 dp = VTOI(vdp);
348 bmask = VFSTOEXT2(vdp->v_mount)->um_mountp->mnt_stat.f_iosize - 1;
349 restart:
350 bp = NULL;
351 ss.slotoffset = -1;
352
353 /*
354 * We now have a segment name to search for, and a directory to search.
355 *
356 * Suppress search for slots unless creating
357 * file and at end of pathname, in which case
358 * we watch for a place to put the new file in
359 * case it doesn't already exist.
360 */
361 i_diroff = dp->i_diroff;
362 ss.slotstatus = FOUND;
363 ss.slotfreespace = ss.slotsize = ss.slotneeded = 0;
364 if ((nameiop == CREATE || nameiop == RENAME) &&
365 (flags & ISLASTCN)) {
366 ss.slotstatus = NONE;
367 ss.slotneeded = EXT2_DIR_REC_LEN(cnp->cn_namelen);
368 /*
369 * was ss.slotneeded = (sizeof(struct direct) - MAXNAMLEN +
370 * cnp->cn_namelen + 3) &~ 3;
371 */
372 }
373 /*
374 * Try to lookup dir entry using htree directory index.
375 *
376 * If we got an error or we want to find '.' or '..' entry,
377 * we will fall back to linear search.
378 */
379 if (!ext2_is_dot_entry(cnp) && ext2_htree_has_idx(dp)) {
380 numdirpasses = 1;
381 entryoffsetinblock = 0;
382 switch (ext2_htree_lookup(dp, cnp->cn_nameptr, cnp->cn_namelen,
383 &bp, &entryoffsetinblock, &i_offset, &prevoff,
384 &enduseful, &ss)) {
385 case 0:
386 ep = (struct ext2fs_direct_2 *)((char *)bp->b_data +
387 (i_offset & bmask));
388 goto foundentry;
389 case ENOENT:
390 i_offset = roundup2(dp->i_size, DIRBLKSIZ);
391 goto notfound;
392 default:
393 /*
394 * Something failed; just fallback to do a linear
395 * search.
396 */
397 break;
398 }
399 }
400
401 /*
402 * If there is cached information on a previous search of
403 * this directory, pick up where we last left off.
404 * We cache only lookups as these are the most common
405 * and have the greatest payoff. Caching CREATE has little
406 * benefit as it usually must search the entire directory
407 * to determine that the entry does not exist. Caching the
408 * location of the last DELETE or RENAME has not reduced
409 * profiling time and hence has been removed in the interest
410 * of simplicity.
411 */
412 if (nameiop != LOOKUP || i_diroff == 0 ||
413 i_diroff > dp->i_size) {
414 entryoffsetinblock = 0;
415 i_offset = 0;
416 numdirpasses = 1;
417 } else {
418 i_offset = i_diroff;
419 if ((entryoffsetinblock = i_offset & bmask) &&
420 (error = ext2_blkatoff(vdp, (off_t)i_offset, NULL,
421 &bp)))
422 return (error);
423 numdirpasses = 2;
424 nchstats.ncs_2passes++;
425 }
426 prevoff = i_offset;
427 endsearch = roundup2(dp->i_size, DIRBLKSIZ);
428 enduseful = 0;
429
430 searchloop:
431 while (i_offset < endsearch) {
432 /*
433 * If necessary, get the next directory block.
434 */
435 if (bp != NULL)
436 brelse(bp);
437 error = ext2_blkatoff(vdp, (off_t)i_offset, NULL, &bp);
438 if (error != 0)
439 return (error);
440
441 entryoffsetinblock = 0;
442 if (ss.slotstatus == NONE) {
443 ss.slotoffset = -1;
444 ss.slotfreespace = 0;
445 }
446
447 error = ext2_search_dirblock(dp, bp->b_data, &entry_found,
448 cnp->cn_nameptr, cnp->cn_namelen,
449 &entryoffsetinblock, &i_offset, &prevoff,
450 &enduseful, &ss);
451 if (error != 0) {
452 brelse(bp);
453 return (error);
454 }
455 if (entry_found) {
456 ep = (struct ext2fs_direct_2 *)((char *)bp->b_data +
457 (entryoffsetinblock & bmask));
458 foundentry:
459 ino = le32toh(ep->e2d_ino);
460 goto found;
461 }
462 }
463 notfound:
464 /*
465 * If we started in the middle of the directory and failed
466 * to find our target, we must check the beginning as well.
467 */
468 if (numdirpasses == 2) {
469 numdirpasses--;
470 i_offset = 0;
471 endsearch = i_diroff;
472 goto searchloop;
473 }
474 if (bp != NULL)
475 brelse(bp);
476 /*
477 * If creating, and at end of pathname and current
478 * directory has not been removed, then can consider
479 * allowing file to be created.
480 */
481 if ((nameiop == CREATE || nameiop == RENAME) &&
482 (flags & ISLASTCN) && dp->i_nlink != 0) {
483 /*
484 * Access for write is interpreted as allowing
485 * creation of files in the directory.
486 */
487 if ((error = VOP_ACCESS(vdp, VWRITE, cred, curthread)) != 0)
488 return (error);
489 /*
490 * Return an indication of where the new directory
491 * entry should be put. If we didn't find a slot,
492 * then set dp->i_count to 0 indicating
493 * that the new slot belongs at the end of the
494 * directory. If we found a slot, then the new entry
495 * can be put in the range from dp->i_offset to
496 * dp->i_offset + dp->i_count.
497 */
498 if (ss.slotstatus == NONE) {
499 dp->i_offset = roundup2(dp->i_size, DIRBLKSIZ);
500 dp->i_count = 0;
501 enduseful = dp->i_offset;
502 } else {
503 dp->i_offset = ss.slotoffset;
504 dp->i_count = ss.slotsize;
505 if (enduseful < ss.slotoffset + ss.slotsize)
506 enduseful = ss.slotoffset + ss.slotsize;
507 }
508 dp->i_endoff = roundup2(enduseful, DIRBLKSIZ);
509 /*
510 * We return with the directory locked, so that
511 * the parameters we set up above will still be
512 * valid if we actually decide to do a direnter().
513 * We return ni_vp == NULL to indicate that the entry
514 * does not currently exist; we leave a pointer to
515 * the (locked) directory inode in ndp->ni_dvp.
516 *
517 * NB - if the directory is unlocked, then this
518 * information cannot be used.
519 */
520 return (EJUSTRETURN);
521 }
522 /*
523 * Insert name into cache (as non-existent) if appropriate.
524 */
525 if ((cnp->cn_flags & MAKEENTRY) != 0)
526 cache_enter(vdp, NULL, cnp);
527 return (ENOENT);
528
529 found:
530 if (dd_ino != NULL)
531 *dd_ino = ino;
532 if (numdirpasses == 2)
533 nchstats.ncs_pass2++;
534 /*
535 * Check that directory length properly reflects presence
536 * of this entry.
537 */
538 if (entryoffsetinblock + EXT2_DIR_REC_LEN(ep->e2d_namlen) >
539 dp->i_size) {
540 ext2_dirbad(dp, i_offset, "i_size too small");
541 brelse(bp);
542 return (EIO);
543 }
544 brelse(bp);
545
546 /*
547 * Found component in pathname.
548 * If the final component of path name, save information
549 * in the cache as to where the entry was found.
550 */
551 if ((flags & ISLASTCN) && nameiop == LOOKUP)
552 dp->i_diroff = rounddown2(i_offset, DIRBLKSIZ);
553 /*
554 * If deleting, and at end of pathname, return
555 * parameters which can be used to remove file.
556 */
557 if (nameiop == DELETE && (flags & ISLASTCN)) {
558 if (flags & LOCKPARENT)
559 ASSERT_VOP_ELOCKED(vdp, __FUNCTION__);
560 /*
561 * Write access to directory required to delete files.
562 */
563 if ((error = VOP_ACCESS(vdp, VWRITE, cred, curthread)) != 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 * Technically we shouldn't be setting these in the
572 * WANTPARENT case (first lookup in rename()), but any
573 * lookups that will result in directory changes will
574 * overwrite these.
575 */
576 dp->i_offset = i_offset;
577 if ((dp->i_offset & (DIRBLKSIZ - 1)) == 0)
578 dp->i_count = 0;
579 else
580 dp->i_count = dp->i_offset - prevoff;
581 if (dd_ino != NULL)
582 return (0);
583 if (dp->i_number == ino) {
584 VREF(vdp);
585 *vpp = vdp;
586 return (0);
587 }
588 if ((error = VFS_VGET(vdp->v_mount, ino, LK_EXCLUSIVE,
589 &tdp)) != 0)
590 return (error);
591 /*
592 * If directory is "sticky", then user must own
593 * the directory, or the file in it, else she
594 * may not delete it (unless she's root). This
595 * implements append-only directories.
596 */
597 if ((dp->i_mode & ISVTX) &&
598 cred->cr_uid != 0 &&
599 cred->cr_uid != dp->i_uid &&
600 VTOI(tdp)->i_uid != cred->cr_uid) {
601 vput(tdp);
602 return (EPERM);
603 }
604 *vpp = tdp;
605 return (0);
606 }
607
608 /*
609 * If rewriting (RENAME), return the inode and the
610 * information required to rewrite the present directory
611 * Must get inode of directory entry to verify it's a
612 * regular file, or empty directory.
613 */
614 if (nameiop == RENAME && (flags & ISLASTCN)) {
615 if ((error = VOP_ACCESS(vdp, VWRITE, cred, curthread)) != 0)
616 return (error);
617 /*
618 * Careful about locking second inode.
619 * This can only occur if the target is ".".
620 */
621 dp->i_offset = i_offset;
622 if (dp->i_number == ino)
623 return (EISDIR);
624 if (dd_ino != NULL)
625 return (0);
626 if ((error = VFS_VGET(vdp->v_mount, ino, LK_EXCLUSIVE,
627 &tdp)) != 0)
628 return (error);
629 *vpp = tdp;
630 return (0);
631 }
632 if (dd_ino != NULL)
633 return (0);
634
635 /*
636 * Step through the translation in the name. We do not `vput' the
637 * directory because we may need it again if a symbolic link
638 * is relative to the current directory. Instead we save it
639 * unlocked as "pdp". We must get the target inode before unlocking
640 * the directory to insure that the inode will not be removed
641 * before we get it. We prevent deadlock by always fetching
642 * inodes from the root, moving down the directory tree. Thus
643 * when following backward pointers ".." we must unlock the
644 * parent directory before getting the requested directory.
645 * There is a potential race condition here if both the current
646 * and parent directories are removed before the VFS_VGET for the
647 * inode associated with ".." returns. We hope that this occurs
648 * infrequently since we cannot avoid this race condition without
649 * implementing a sophisticated deadlock detection algorithm.
650 * Note also that this simple deadlock detection scheme will not
651 * work if the file system has any hard links other than ".."
652 * that point backwards in the directory structure.
653 */
654 pdp = vdp;
655 if (flags & ISDOTDOT) {
656 error = vn_vget_ino(pdp, ino, cnp->cn_lkflags, &tdp);
657 if (VN_IS_DOOMED(pdp)) {
658 if (error == 0)
659 vput(tdp);
660 error = ENOENT;
661 }
662 if (error)
663 return (error);
664 /*
665 * Recheck that ".." entry in the vdp directory points
666 * to the inode we looked up before vdp lock was
667 * dropped.
668 */
669 error = ext2_lookup_ino(pdp, NULL, cnp, &ino1);
670 if (error) {
671 vput(tdp);
672 return (error);
673 }
674 if (ino1 != ino) {
675 vput(tdp);
676 goto restart;
677 }
678 *vpp = tdp;
679 } else if (dp->i_number == ino) {
680 VREF(vdp); /* we want ourself, ie "." */
681 /*
682 * When we lookup "." we still can be asked to lock it
683 * differently.
684 */
685 ltype = cnp->cn_lkflags & LK_TYPE_MASK;
686 if (ltype != VOP_ISLOCKED(vdp)) {
687 if (ltype == LK_EXCLUSIVE)
688 vn_lock(vdp, LK_UPGRADE | LK_RETRY);
689 else /* if (ltype == LK_SHARED) */
690 vn_lock(vdp, LK_DOWNGRADE | LK_RETRY);
691 }
692 *vpp = vdp;
693 } else {
694 if ((error = VFS_VGET(vdp->v_mount, ino, cnp->cn_lkflags,
695 &tdp)) != 0)
696 return (error);
697 *vpp = tdp;
698 }
699
700 /*
701 * Insert name into cache if appropriate.
702 */
703 if (cnp->cn_flags & MAKEENTRY)
704 cache_enter(vdp, *vpp, cnp);
705 return (0);
706 }
707
708 int
ext2_search_dirblock(struct inode * ip,void * data,int * foundp,const char * name,int namelen,int * entryoffsetinblockp,doff_t * offp,doff_t * prevoffp,doff_t * endusefulp,struct ext2fs_searchslot * ssp)709 ext2_search_dirblock(struct inode *ip, void *data, int *foundp,
710 const char *name, int namelen, int *entryoffsetinblockp,
711 doff_t *offp, doff_t *prevoffp, doff_t *endusefulp,
712 struct ext2fs_searchslot *ssp)
713 {
714 struct vnode *vdp;
715 struct ext2fs_direct_2 *ep, *top;
716 uint32_t bsize = ip->i_e2fs->e2fs_bsize;
717 int offset = *entryoffsetinblockp;
718 int namlen;
719
720 vdp = ITOV(ip);
721
722 ep = (struct ext2fs_direct_2 *)((char *)data + offset);
723 top = (struct ext2fs_direct_2 *)((char *)data + bsize);
724 while (ep < top) {
725 if (ext2_check_direntry(vdp, ep, offset)) {
726 int i;
727
728 ext2_dirbad(ip, *offp, "mangled entry");
729 i = bsize - (offset & (bsize - 1));
730 *offp += i;
731 offset += i;
732 ep = (struct ext2fs_direct_2 *)((char *)data + offset);
733 continue;
734 }
735
736 /*
737 * If an appropriate sized slot has not yet been found,
738 * check to see if one is available. Also accumulate space
739 * in the current block so that we can determine if
740 * compaction is viable.
741 */
742 if (ssp->slotstatus != FOUND) {
743 int size = le16toh(ep->e2d_reclen);
744
745 if (ep->e2d_ino != 0)
746 size -= EXT2_DIR_REC_LEN(ep->e2d_namlen);
747 else if (ext2_is_dirent_tail(ip, ep))
748 size -= sizeof(struct ext2fs_direct_tail);
749 if (size > 0) {
750 if (size >= ssp->slotneeded) {
751 ssp->slotstatus = FOUND;
752 ssp->slotoffset = *offp;
753 ssp->slotsize = le16toh(ep->e2d_reclen);
754 } else if (ssp->slotstatus == NONE) {
755 ssp->slotfreespace += size;
756 if (ssp->slotoffset == -1)
757 ssp->slotoffset = *offp;
758 if (ssp->slotfreespace >= ssp->slotneeded) {
759 ssp->slotstatus = COMPACT;
760 ssp->slotsize = *offp +
761 le16toh(ep->e2d_reclen) -
762 ssp->slotoffset;
763 }
764 }
765 }
766 }
767 /*
768 * Check for a name match.
769 */
770 if (ep->e2d_ino != 0) {
771 namlen = ep->e2d_namlen;
772 if (namlen == namelen &&
773 !bcmp(name, ep->e2d_name, (unsigned)namlen)) {
774 /*
775 * Save directory entry's inode number and
776 * reclen in ndp->ni_ufs area, and release
777 * directory buffer.
778 */
779 *foundp = 1;
780 return (0);
781 }
782 }
783 *prevoffp = *offp;
784 *offp += le16toh(ep->e2d_reclen);
785 offset += le16toh(ep->e2d_reclen);
786 *entryoffsetinblockp = offset;
787 if (ep->e2d_ino != 0)
788 *endusefulp = *offp;
789 /*
790 * Get pointer to the next entry.
791 */
792 ep = (struct ext2fs_direct_2 *)((char *)data + offset);
793 }
794
795 return (0);
796 }
797
798 void
ext2_dirbad(struct inode * ip,doff_t offset,char * how)799 ext2_dirbad(struct inode *ip, doff_t offset, char *how)
800 {
801
802 SDT_PROBE4(ext2fs, , trace, ext2_dirbad_error,
803 ITOV(ip)->v_mount->mnt_stat.f_mntonname, ip->i_number, offset, how);
804 }
805
806 /*
807 * Do consistency checking on a directory entry:
808 * record length must be multiple of 4
809 * entry must fit in rest of its DIRBLKSIZ block
810 * record must be large enough to contain entry
811 * name is not longer than MAXNAMLEN
812 * name must be as long as advertised, and null terminated
813 * inode number less then inode count
814 * if root inode entry, it have correct name
815 */
816 static int
ext2_check_direntry(struct vnode * dp,struct ext2fs_direct_2 * de,int entryoffsetinblock)817 ext2_check_direntry(struct vnode *dp, struct ext2fs_direct_2 *de,
818 int entryoffsetinblock)
819 {
820 struct m_ext2fs *fs = VTOI(dp)->i_e2fs;
821 char *error_msg = NULL;
822
823 if (le16toh(de->e2d_reclen) < EXT2_DIR_REC_LEN(1))
824 error_msg = "rec_len is smaller than minimal";
825 else if (le16toh(de->e2d_reclen) % 4 != 0)
826 error_msg = "rec_len % 4 != 0";
827 else if (le16toh(de->e2d_reclen) < EXT2_DIR_REC_LEN(de->e2d_namlen))
828 error_msg = "reclen is too small for name_len";
829 else if (entryoffsetinblock + le16toh(de->e2d_reclen)> fs->e2fs_bsize)
830 error_msg = "directory entry across blocks";
831 else if (le32toh(de->e2d_ino) > fs->e2fs->e2fs_icount)
832 error_msg = "directory entry inode out of bounds";
833 else if (le32toh(de->e2d_ino) == EXT2_ROOTINO &&
834 ((de->e2d_namlen != 1 && de->e2d_namlen != 2) ||
835 (de->e2d_name[0] != '.') ||
836 (de->e2d_namlen == 2 && de->e2d_name[1] != '.')))
837 error_msg = "bad root directory entry";
838
839 if (error_msg != NULL) {
840 SDT_PROBE5(ext2fs, , trace, ext2_dirbadentry_error,
841 error_msg, entryoffsetinblock,
842 le32toh(de->e2d_ino), le16toh(de->e2d_reclen),
843 de->e2d_namlen);
844 }
845 return (error_msg == NULL ? 0 : EINVAL);
846 }
847
848 /*
849 * Insert an entry into the fresh directory block.
850 * Initialize entry tail if the metadata_csum feature is turned on.
851 */
852 static int
ext2_add_first_entry(struct vnode * dvp,struct ext2fs_direct_2 * entry,struct componentname * cnp)853 ext2_add_first_entry(struct vnode *dvp, struct ext2fs_direct_2 *entry,
854 struct componentname *cnp)
855 {
856 struct inode *dp;
857 struct iovec aiov;
858 struct uio auio;
859 char* buf = NULL;
860 int dirblksize, error;
861
862 dp = VTOI(dvp);
863 dirblksize = dp->i_e2fs->e2fs_bsize;
864
865 if (dp->i_offset & (dirblksize - 1))
866 panic("ext2_add_first_entry: bad directory offset");
867
868 if (EXT2_HAS_RO_COMPAT_FEATURE(dp->i_e2fs,
869 EXT2F_ROCOMPAT_METADATA_CKSUM)) {
870 entry->e2d_reclen = htole16(dirblksize -
871 sizeof(struct ext2fs_direct_tail));
872 buf = malloc(dirblksize, M_TEMP, M_WAITOK);
873 memcpy(buf, entry, EXT2_DIR_REC_LEN(entry->e2d_namlen));
874 ext2_init_dirent_tail(EXT2_DIRENT_TAIL(buf, dirblksize));
875 ext2_dirent_csum_set(dp, (struct ext2fs_direct_2 *)buf);
876
877 auio.uio_offset = dp->i_offset;
878 auio.uio_resid = dirblksize;
879 aiov.iov_len = auio.uio_resid;
880 aiov.iov_base = (caddr_t)buf;
881 } else {
882 entry->e2d_reclen = htole16(dirblksize);
883 auio.uio_offset = dp->i_offset;
884 auio.uio_resid = EXT2_DIR_REC_LEN(entry->e2d_namlen);
885 aiov.iov_len = auio.uio_resid;
886 aiov.iov_base = (caddr_t)entry;
887 }
888
889 auio.uio_iov = &aiov;
890 auio.uio_iovcnt = 1;
891 auio.uio_rw = UIO_WRITE;
892 auio.uio_segflg = UIO_SYSSPACE;
893 auio.uio_td = (struct thread *)0;
894 error = VOP_WRITE(dvp, &auio, IO_SYNC, cnp->cn_cred);
895 if (error)
896 goto out;
897
898 dp->i_size = roundup2(dp->i_size, dirblksize);
899 dp->i_flag |= IN_CHANGE;
900
901 out:
902 free(buf, M_TEMP);
903 return (error);
904
905 }
906
907 /*
908 * Write a directory entry after a call to namei, using the parameters
909 * that it left in nameidata. The argument ip is the inode which the new
910 * directory entry will refer to. Dvp is a pointer to the directory to
911 * be written, which was left locked by namei. Remaining parameters
912 * (dp->i_offset, dp->i_count) indicate how the space for the new
913 * entry is to be obtained.
914 */
915 int
ext2_direnter(struct inode * ip,struct vnode * dvp,struct componentname * cnp)916 ext2_direnter(struct inode *ip, struct vnode *dvp, struct componentname *cnp)
917 {
918 struct inode *dp;
919 struct ext2fs_direct_2 newdir;
920 int DIRBLKSIZ = ip->i_e2fs->e2fs_bsize;
921 int error;
922
923 dp = VTOI(dvp);
924 newdir.e2d_ino = htole32(ip->i_number);
925 if (EXT2_HAS_INCOMPAT_FEATURE(ip->i_e2fs,
926 EXT2F_INCOMPAT_FTYPE)) {
927 newdir.e2d_namlen = cnp->cn_namelen;
928 newdir.e2d_type = DTTOFT(IFTODT(ip->i_mode));
929 } else
930 newdir.e2d_namlen = htole16(cnp->cn_namelen);
931
932 bcopy(cnp->cn_nameptr, newdir.e2d_name, (unsigned)cnp->cn_namelen + 1);
933
934 if (ext2_htree_has_idx(dp)) {
935 error = ext2_htree_add_entry(dvp, &newdir, cnp);
936 if (error) {
937 dp->i_flag &= ~IN_E3INDEX;
938 dp->i_flag |= IN_CHANGE | IN_UPDATE;
939 }
940 return (error);
941 }
942
943 if (EXT2_HAS_COMPAT_FEATURE(ip->i_e2fs, EXT2F_COMPAT_DIRHASHINDEX) &&
944 !ext2_htree_has_idx(dp)) {
945 if ((dp->i_size / DIRBLKSIZ) == 1 &&
946 dp->i_offset == DIRBLKSIZ) {
947 /*
948 * Making indexed directory when one block is not
949 * enough to save all entries.
950 */
951 return ext2_htree_create_index(dvp, cnp, &newdir);
952 }
953 }
954
955 /*
956 * If dp->i_count is 0, then namei could find no
957 * space in the directory. Here, dp->i_offset will
958 * be on a directory block boundary and we will write the
959 * new entry into a fresh block.
960 */
961 if (dp->i_count == 0)
962 return ext2_add_first_entry(dvp, &newdir, cnp);
963
964 error = ext2_add_entry(dvp, &newdir);
965 if (!error && dp->i_endoff && dp->i_endoff < dp->i_size)
966 error = ext2_truncate(dvp, (off_t)dp->i_endoff, IO_SYNC,
967 cnp->cn_cred, curthread);
968 return (error);
969 }
970
971 /*
972 * Insert an entry into the directory block.
973 * Compact the contents.
974 */
975 int
ext2_add_entry(struct vnode * dvp,struct ext2fs_direct_2 * entry)976 ext2_add_entry(struct vnode *dvp, struct ext2fs_direct_2 *entry)
977 {
978 struct ext2fs_direct_2 *ep, *nep;
979 struct inode *dp;
980 struct buf *bp;
981 u_int dsize;
982 int error, loc, newentrysize, spacefree;
983 char *dirbuf;
984
985 dp = VTOI(dvp);
986
987 /*
988 * If dp->i_count is non-zero, then namei found space
989 * for the new entry in the range dp->i_offset to
990 * dp->i_offset + dp->i_count in the directory.
991 * To use this space, we may have to compact the entries located
992 * there, by copying them together towards the beginning of the
993 * block, leaving the free space in one usable chunk at the end.
994 */
995
996 /*
997 * Increase size of directory if entry eats into new space.
998 * This should never push the size past a new multiple of
999 * DIRBLKSIZE.
1000 *
1001 * N.B. - THIS IS AN ARTIFACT OF 4.2 AND SHOULD NEVER HAPPEN.
1002 */
1003 if (dp->i_offset + dp->i_count > dp->i_size)
1004 dp->i_size = dp->i_offset + dp->i_count;
1005 /*
1006 * Get the block containing the space for the new directory entry.
1007 */
1008 if ((error = ext2_blkatoff(dvp, (off_t)dp->i_offset, &dirbuf,
1009 &bp)) != 0)
1010 return (error);
1011 /*
1012 * Find space for the new entry. In the simple case, the entry at
1013 * offset base will have the space. If it does not, then namei
1014 * arranged that compacting the region dp->i_offset to
1015 * dp->i_offset + dp->i_count would yield the
1016 * space.
1017 */
1018 newentrysize = EXT2_DIR_REC_LEN(entry->e2d_namlen);
1019 ep = (struct ext2fs_direct_2 *)dirbuf;
1020 dsize = EXT2_DIR_REC_LEN(ep->e2d_namlen);
1021 spacefree = le16toh(ep->e2d_reclen) - dsize;
1022 for (loc = le16toh(ep->e2d_reclen); loc < dp->i_count; ) {
1023 nep = (struct ext2fs_direct_2 *)(dirbuf + loc);
1024 if (le32toh(ep->e2d_ino)) {
1025 /* trim the existing slot */
1026 ep->e2d_reclen = htole16(dsize);
1027 ep = (struct ext2fs_direct_2 *)((char *)ep + dsize);
1028 } else {
1029 /* overwrite; nothing there; header is ours */
1030 spacefree += dsize;
1031 }
1032 dsize = EXT2_DIR_REC_LEN(nep->e2d_namlen);
1033 spacefree += le16toh(nep->e2d_reclen) - dsize;
1034 loc += le16toh(nep->e2d_reclen);
1035 bcopy((caddr_t)nep, (caddr_t)ep, dsize);
1036 }
1037 /*
1038 * Update the pointer fields in the previous entry (if any),
1039 * copy in the new entry, and write out the block.
1040 */
1041 if (ep->e2d_ino == 0) {
1042 if (spacefree + dsize < newentrysize)
1043 panic("ext2_direnter: compact1");
1044 entry->e2d_reclen = htole16(spacefree + dsize);
1045 } else {
1046 if (spacefree < newentrysize)
1047 panic("ext2_direnter: compact2");
1048 entry->e2d_reclen = htole16(spacefree);
1049 ep->e2d_reclen = htole16(dsize);
1050 ep = (struct ext2fs_direct_2 *)((char *)ep + dsize);
1051 }
1052 bcopy((caddr_t)entry, (caddr_t)ep, (u_int)newentrysize);
1053 ext2_dirent_csum_set(dp, (struct ext2fs_direct_2 *)bp->b_data);
1054 if (DOINGASYNC(dvp)) {
1055 bdwrite(bp);
1056 error = 0;
1057 } else {
1058 error = bwrite(bp);
1059 }
1060 dp->i_flag |= IN_CHANGE | IN_UPDATE;
1061 return (error);
1062 }
1063
1064 /*
1065 * Remove a directory entry after a call to namei, using
1066 * the parameters which it left in nameidata. The entry
1067 * dp->i_offset contains the offset into the directory of the
1068 * entry to be eliminated. The dp->i_count field contains the
1069 * size of the previous record in the directory. If this
1070 * is 0, the first entry is being deleted, so we need only
1071 * zero the inode number to mark the entry as free. If the
1072 * entry is not the first in the directory, we must reclaim
1073 * the space of the now empty record by adding the record size
1074 * to the size of the previous entry.
1075 */
1076 int
ext2_dirremove(struct vnode * dvp,struct componentname * cnp)1077 ext2_dirremove(struct vnode *dvp, struct componentname *cnp)
1078 {
1079 struct inode *dp;
1080 struct ext2fs_direct_2 *ep, *rep;
1081 struct buf *bp;
1082 int error;
1083
1084 dp = VTOI(dvp);
1085 if (dp->i_count == 0) {
1086 /*
1087 * First entry in block: set d_ino to zero.
1088 */
1089 if ((error =
1090 ext2_blkatoff(dvp, (off_t)dp->i_offset, (char **)&ep,
1091 &bp)) != 0)
1092 return (error);
1093 ep->e2d_ino = 0;
1094 ext2_dirent_csum_set(dp, (struct ext2fs_direct_2 *)bp->b_data);
1095 error = bwrite(bp);
1096 dp->i_flag |= IN_CHANGE | IN_UPDATE;
1097 return (error);
1098 }
1099 /*
1100 * Collapse new free space into previous entry.
1101 */
1102 if ((error = ext2_blkatoff(dvp, (off_t)(dp->i_offset - dp->i_count),
1103 (char **)&ep, &bp)) != 0)
1104 return (error);
1105
1106 /* Set 'rep' to the entry being removed. */
1107 if (dp->i_count == 0)
1108 rep = ep;
1109 else
1110 rep = (struct ext2fs_direct_2 *)((char *)ep +
1111 le16toh(ep->e2d_reclen));
1112 ep->e2d_reclen += rep->e2d_reclen;
1113 ext2_dirent_csum_set(dp, (struct ext2fs_direct_2 *)bp->b_data);
1114 if (DOINGASYNC(dvp) && dp->i_count != 0)
1115 bdwrite(bp);
1116 else
1117 error = bwrite(bp);
1118 dp->i_flag |= IN_CHANGE | IN_UPDATE;
1119 return (error);
1120 }
1121
1122 /*
1123 * Rewrite an existing directory entry to point at the inode
1124 * supplied. The parameters describing the directory entry are
1125 * set up by a call to namei.
1126 */
1127 int
ext2_dirrewrite(struct inode * dp,struct inode * ip,struct componentname * cnp)1128 ext2_dirrewrite(struct inode *dp, struct inode *ip, struct componentname *cnp)
1129 {
1130 struct buf *bp;
1131 struct ext2fs_direct_2 *ep;
1132 struct vnode *vdp = ITOV(dp);
1133 int error;
1134
1135 if ((error = ext2_blkatoff(vdp, (off_t)dp->i_offset, (char **)&ep,
1136 &bp)) != 0)
1137 return (error);
1138 ep->e2d_ino = htole32(ip->i_number);
1139 if (EXT2_HAS_INCOMPAT_FEATURE(ip->i_e2fs,
1140 EXT2F_INCOMPAT_FTYPE))
1141 ep->e2d_type = DTTOFT(IFTODT(ip->i_mode));
1142 else
1143 ep->e2d_type = EXT2_FT_UNKNOWN;
1144 ext2_dirent_csum_set(dp, (struct ext2fs_direct_2 *)bp->b_data);
1145 error = bwrite(bp);
1146 dp->i_flag |= IN_CHANGE | IN_UPDATE;
1147 return (error);
1148 }
1149
1150 /*
1151 * Check if a directory is empty or not.
1152 * Inode supplied must be locked.
1153 *
1154 * Using a struct dirtemplate here is not precisely
1155 * what we want, but better than using a struct direct.
1156 *
1157 * NB: does not handle corrupted directories.
1158 */
1159 int
ext2_dirempty(struct inode * ip,ino_t parentino,struct ucred * cred)1160 ext2_dirempty(struct inode *ip, ino_t parentino, struct ucred *cred)
1161 {
1162 off_t off;
1163 struct dirtemplate dbuf;
1164 struct ext2fs_direct_2 *dp = (struct ext2fs_direct_2 *)&dbuf;
1165 int error, namlen;
1166 ssize_t count;
1167 #define MINDIRSIZ (sizeof(struct dirtemplate) / 2)
1168
1169 for (off = 0; off < ip->i_size; off += le16toh(dp->e2d_reclen)) {
1170 error = vn_rdwr(UIO_READ, ITOV(ip), (caddr_t)dp, MINDIRSIZ,
1171 off, UIO_SYSSPACE, IO_NODELOCKED | IO_NOMACCHECK, cred,
1172 NOCRED, &count, (struct thread *)0);
1173 /*
1174 * Since we read MINDIRSIZ, residual must
1175 * be 0 unless we're at end of file.
1176 */
1177 if (error || count != 0)
1178 return (0);
1179 /* avoid infinite loops */
1180 if (dp->e2d_reclen == 0)
1181 return (0);
1182 /* skip empty entries */
1183 if (dp->e2d_ino == 0)
1184 continue;
1185 /* accept only "." and ".." */
1186 namlen = dp->e2d_namlen;
1187 if (namlen > 2)
1188 return (0);
1189 if (dp->e2d_name[0] != '.')
1190 return (0);
1191 /*
1192 * At this point namlen must be 1 or 2.
1193 * 1 implies ".", 2 implies ".." if second
1194 * char is also "."
1195 */
1196 if (namlen == 1)
1197 continue;
1198 if (dp->e2d_name[1] == '.' && le32toh(dp->e2d_ino) == parentino)
1199 continue;
1200 return (0);
1201 }
1202 return (1);
1203 }
1204
1205 /*
1206 * Check if source directory is in the path of the target directory.
1207 * Target is supplied locked, source is unlocked.
1208 * The target is always vput before returning.
1209 */
1210 int
ext2_checkpath(struct inode * source,struct inode * target,struct ucred * cred)1211 ext2_checkpath(struct inode *source, struct inode *target, struct ucred *cred)
1212 {
1213 struct vnode *vp;
1214 int error, namlen;
1215 struct dirtemplate dirbuf;
1216
1217 vp = ITOV(target);
1218 if (target->i_number == source->i_number) {
1219 error = EEXIST;
1220 goto out;
1221 }
1222 if (target->i_number == EXT2_ROOTINO) {
1223 error = 0;
1224 goto out;
1225 }
1226
1227 for (;;) {
1228 if (vp->v_type != VDIR) {
1229 error = ENOTDIR;
1230 break;
1231 }
1232 error = vn_rdwr(UIO_READ, vp, (caddr_t)&dirbuf,
1233 sizeof(struct dirtemplate), (off_t)0, UIO_SYSSPACE,
1234 IO_NODELOCKED | IO_NOMACCHECK, cred, NOCRED, NULL,
1235 NULL);
1236 if (error != 0)
1237 break;
1238 namlen = dirbuf.dotdot_type; /* like ufs little-endian */
1239 if (namlen != 2 ||
1240 dirbuf.dotdot_name[0] != '.' ||
1241 dirbuf.dotdot_name[1] != '.') {
1242 error = ENOTDIR;
1243 break;
1244 }
1245 if (le32toh(dirbuf.dotdot_ino) == source->i_number) {
1246 error = EINVAL;
1247 break;
1248 }
1249 if (le32toh(dirbuf.dotdot_ino) == EXT2_ROOTINO)
1250 break;
1251 vput(vp);
1252 if ((error = VFS_VGET(vp->v_mount, le32toh(dirbuf.dotdot_ino),
1253 LK_EXCLUSIVE, &vp)) != 0) {
1254 vp = NULL;
1255 break;
1256 }
1257 }
1258
1259 out:
1260 if (error == ENOTDIR)
1261 SDT_PROBE2(ext2fs, , lookup, trace, 1,
1262 "checkpath: .. not a directory");
1263 if (vp != NULL)
1264 vput(vp);
1265 return (error);
1266 }
1267