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 /*-
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
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/namei.h>
46 #include <sys/bio.h>
47 #include <sys/buf.h>
48 #include <sys/endian.h>
49 #include <sys/mount.h>
50 #include <sys/vnode.h>
51 #include <sys/malloc.h>
52 #include <sys/dirent.h>
53 #include <sys/sdt.h>
54 #include <sys/sysctl.h>
55
56 #include <ufs/ufs/dir.h>
57
58 #include <fs/ext2fs/fs.h>
59 #include <fs/ext2fs/inode.h>
60 #include <fs/ext2fs/ext2_mount.h>
61 #include <fs/ext2fs/ext2fs.h>
62 #include <fs/ext2fs/ext2_dinode.h>
63 #include <fs/ext2fs/ext2_dir.h>
64 #include <fs/ext2fs/ext2_extern.h>
65 #include <fs/ext2fs/fs.h>
66
67 SDT_PROVIDER_DECLARE(ext2fs);
68 /*
69 * ext2fs trace probe:
70 * arg0: verbosity. Higher numbers give more verbose messages
71 * arg1: Textual message
72 */
73 SDT_PROBE_DEFINE2(ext2fs, , lookup, trace, "int", "char*");
74 SDT_PROBE_DEFINE4(ext2fs, , trace, ext2_dirbad_error,
75 "char*", "ino_t", "doff_t", "char*");
76 SDT_PROBE_DEFINE5(ext2fs, , trace, ext2_dirbadentry_error,
77 "char*", "int", "uint32_t", "uint16_t", "uint8_t");
78
79 static SYSCTL_NODE(_vfs, OID_AUTO, e2fs, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
80 "EXT2FS filesystem");
81
82 /*
83 DIRBLKSIZE in ffs is DEV_BSIZE (in most cases 512)
84 while it is the native blocksize in ext2fs - thus, a #define
85 is no longer appropriate
86 */
87 #undef DIRBLKSIZ
88
89 static u_char ext2_ft_to_dt[] = {
90 DT_UNKNOWN, /* EXT2_FT_UNKNOWN */
91 DT_REG, /* EXT2_FT_REG_FILE */
92 DT_DIR, /* EXT2_FT_DIR */
93 DT_CHR, /* EXT2_FT_CHRDEV */
94 DT_BLK, /* EXT2_FT_BLKDEV */
95 DT_FIFO, /* EXT2_FT_FIFO */
96 DT_SOCK, /* EXT2_FT_SOCK */
97 DT_LNK, /* EXT2_FT_SYMLINK */
98 };
99 #define FTTODT(ft) \
100 ((ft) < nitems(ext2_ft_to_dt) ? ext2_ft_to_dt[(ft)] : DT_UNKNOWN)
101
102 static u_char dt_to_ext2_ft[] = {
103 EXT2_FT_UNKNOWN, /* DT_UNKNOWN */
104 EXT2_FT_FIFO, /* DT_FIFO */
105 EXT2_FT_CHRDEV, /* DT_CHR */
106 EXT2_FT_UNKNOWN, /* unused */
107 EXT2_FT_DIR, /* DT_DIR */
108 EXT2_FT_UNKNOWN, /* unused */
109 EXT2_FT_BLKDEV, /* DT_BLK */
110 EXT2_FT_UNKNOWN, /* unused */
111 EXT2_FT_REG_FILE, /* DT_REG */
112 EXT2_FT_UNKNOWN, /* unused */
113 EXT2_FT_SYMLINK, /* DT_LNK */
114 EXT2_FT_UNKNOWN, /* unused */
115 EXT2_FT_SOCK, /* DT_SOCK */
116 EXT2_FT_UNKNOWN, /* unused */
117 EXT2_FT_UNKNOWN, /* DT_WHT */
118 };
119 #define DTTOFT(dt) \
120 ((dt) < nitems(dt_to_ext2_ft) ? dt_to_ext2_ft[(dt)] : EXT2_FT_UNKNOWN)
121
122 static int ext2_check_direntry(struct vnode *dp,
123 struct ext2fs_direct_2 *de, int entryoffsetinblock);
124 static int ext2_is_dot_entry(struct componentname *cnp);
125 static int ext2_lookup_ino(struct vnode *vdp, struct vnode **vpp,
126 struct componentname *cnp, ino_t *dd_ino);
127
128 static int
ext2_is_dot_entry(struct componentname * cnp)129 ext2_is_dot_entry(struct componentname *cnp)
130 {
131 if (cnp->cn_namelen <= 2 && cnp->cn_nameptr[0] == '.' &&
132 (cnp->cn_nameptr[1] == '.' || cnp->cn_nameptr[1] == '\0'))
133 return (1);
134 return (0);
135 }
136
137 /*
138 * Vnode op for reading directories.
139 */
140 int
ext2_readdir(struct vop_readdir_args * ap)141 ext2_readdir(struct vop_readdir_args *ap)
142 {
143 struct vnode *vp = ap->a_vp;
144 struct uio *uio = ap->a_uio;
145 struct buf *bp;
146 struct inode *ip;
147 struct ext2fs_direct_2 *dp, *edp;
148 uint64_t *cookies;
149 struct dirent dstdp;
150 off_t offset, startoffset;
151 size_t readcnt, skipcnt;
152 ssize_t startresid;
153 u_int ncookies;
154 int DIRBLKSIZ = VTOI(ap->a_vp)->i_e2fs->e2fs_bsize;
155 int error;
156
157 if (uio->uio_offset < 0)
158 return (EINVAL);
159 ip = VTOI(vp);
160 if (ap->a_ncookies != NULL) {
161 if (uio->uio_resid < 0)
162 ncookies = 0;
163 else
164 ncookies = uio->uio_resid;
165 if (uio->uio_offset >= ip->i_size)
166 ncookies = 0;
167 else if (ip->i_size - uio->uio_offset < ncookies)
168 ncookies = ip->i_size - uio->uio_offset;
169 ncookies = ncookies / (offsetof(struct ext2fs_direct_2,
170 e2d_namlen) + 4) + 1;
171 cookies = malloc(ncookies * sizeof(*cookies), M_TEMP, M_WAITOK);
172 *ap->a_ncookies = ncookies;
173 *ap->a_cookies = cookies;
174 } else {
175 ncookies = 0;
176 cookies = NULL;
177 }
178 offset = startoffset = uio->uio_offset;
179 startresid = uio->uio_resid;
180 error = 0;
181 while (error == 0 && uio->uio_resid > 0 &&
182 uio->uio_offset < ip->i_size) {
183 error = ext2_blkatoff(vp, uio->uio_offset, NULL, &bp);
184 if (error)
185 break;
186 if (bp->b_offset + bp->b_bcount > ip->i_size)
187 readcnt = ip->i_size - bp->b_offset;
188 else
189 readcnt = bp->b_bcount;
190 skipcnt = (size_t)(uio->uio_offset - bp->b_offset) &
191 ~(size_t)(DIRBLKSIZ - 1);
192 offset = bp->b_offset + skipcnt;
193 dp = (struct ext2fs_direct_2 *)&bp->b_data[skipcnt];
194 edp = (struct ext2fs_direct_2 *)&bp->b_data[readcnt];
195 while (error == 0 && uio->uio_resid > 0 && dp < edp) {
196 if (le16toh(dp->e2d_reclen) <= offsetof(struct ext2fs_direct_2,
197 e2d_namlen) || (caddr_t)dp + le16toh(dp->e2d_reclen) >
198 (caddr_t)edp) {
199 error = EIO;
200 break;
201 }
202 /*-
203 * "New" ext2fs directory entries differ in 3 ways
204 * from ufs on-disk ones:
205 * - the name is not necessarily NUL-terminated.
206 * - the file type field always exists and always
207 * follows the name length field.
208 * - the file type is encoded in a different way.
209 *
210 * "Old" ext2fs directory entries need no special
211 * conversions, since they are binary compatible
212 * with "new" entries having a file type of 0 (i.e.,
213 * EXT2_FT_UNKNOWN). Splitting the old name length
214 * field didn't make a mess like it did in ufs,
215 * because ext2fs uses a machine-independent disk
216 * layout.
217 */
218 dstdp.d_namlen = dp->e2d_namlen;
219 dstdp.d_type = FTTODT(dp->e2d_type);
220 if (offsetof(struct ext2fs_direct_2, e2d_namlen) +
221 dstdp.d_namlen > le16toh(dp->e2d_reclen)) {
222 error = EIO;
223 break;
224 }
225 if (offset < startoffset || le32toh(dp->e2d_ino) == 0)
226 goto nextentry;
227 dstdp.d_fileno = le32toh(dp->e2d_ino);
228 dstdp.d_reclen = GENERIC_DIRSIZ(&dstdp);
229 bcopy(dp->e2d_name, dstdp.d_name, dstdp.d_namlen);
230 /* NOTE: d_off is the offset of the *next* entry. */
231 dstdp.d_off = offset + le16toh(dp->e2d_reclen);
232 dirent_terminate(&dstdp);
233 if (dstdp.d_reclen > uio->uio_resid) {
234 if (uio->uio_resid == startresid)
235 error = EINVAL;
236 else
237 error = EJUSTRETURN;
238 break;
239 }
240 /* Advance dp. */
241 error = uiomove((caddr_t)&dstdp, dstdp.d_reclen, uio);
242 if (error)
243 break;
244 if (cookies != NULL) {
245 KASSERT(ncookies > 0,
246 ("ext2_readdir: cookies buffer too small"));
247 *cookies = offset + le16toh(dp->e2d_reclen);
248 cookies++;
249 ncookies--;
250 }
251 nextentry:
252 offset += le16toh(dp->e2d_reclen);
253 dp = (struct ext2fs_direct_2 *)((caddr_t)dp +
254 le16toh(dp->e2d_reclen));
255 }
256 bqrelse(bp);
257 uio->uio_offset = offset;
258 }
259 /* We need to correct uio_offset. */
260 uio->uio_offset = offset;
261 if (error == EJUSTRETURN)
262 error = 0;
263 if (ap->a_ncookies != NULL) {
264 if (error == 0) {
265 *ap->a_ncookies -= ncookies;
266 } else {
267 free(*ap->a_cookies, M_TEMP);
268 *ap->a_ncookies = 0;
269 *ap->a_cookies = NULL;
270 }
271 }
272 if (error == 0 && ap->a_eofflag)
273 *ap->a_eofflag = ip->i_size <= uio->uio_offset;
274 return (error);
275 }
276
277 /*
278 * Convert a component of a pathname into a pointer to a locked inode.
279 * This is a very central and rather complicated routine.
280 * If the file system is not maintained in a strict tree hierarchy,
281 * this can result in a deadlock situation (see comments in code below).
282 *
283 * The cnp->cn_nameiop argument is LOOKUP, CREATE, RENAME, or DELETE depending
284 * on whether the name is to be looked up, created, renamed, or deleted.
285 * When CREATE, RENAME, or DELETE is specified, information usable in
286 * creating, renaming, or deleting a directory entry may be calculated.
287 * If flag has LOCKPARENT or'ed into it and the target of the pathname
288 * exists, lookup returns both the target and its parent directory locked.
289 * When creating or renaming and LOCKPARENT is specified, the target may
290 * not be ".". When deleting and LOCKPARENT is specified, the target may
291 * be "."., but the caller must check to ensure it does an vrele and vput
292 * instead of two vputs.
293 *
294 * Overall outline of ext2_lookup:
295 *
296 * search for name in directory, to found or notfound
297 * notfound:
298 * if creating, return locked directory, leaving info on available slots
299 * else return error
300 * found:
301 * if at end of path and deleting, return information to allow delete
302 * if at end of path and rewriting (RENAME and LOCKPARENT), lock target
303 * inode and return info to allow rewrite
304 * if not at end, add name to cache; if at end and neither creating
305 * nor deleting, add name to cache
306 */
307 int
ext2_lookup(struct vop_cachedlookup_args * ap)308 ext2_lookup(struct vop_cachedlookup_args *ap)
309 {
310
311 return (ext2_lookup_ino(ap->a_dvp, ap->a_vpp, ap->a_cnp, NULL));
312 }
313
314 static int
ext2_lookup_ino(struct vnode * vdp,struct vnode ** vpp,struct componentname * cnp,ino_t * dd_ino)315 ext2_lookup_ino(struct vnode *vdp, struct vnode **vpp, struct componentname *cnp,
316 ino_t *dd_ino)
317 {
318 struct inode *dp; /* inode for directory being searched */
319 struct buf *bp; /* a buffer of directory entries */
320 struct ext2fs_direct_2 *ep; /* the current directory entry */
321 int entryoffsetinblock; /* offset of ep in bp's buffer */
322 struct ext2fs_searchslot ss;
323 doff_t i_diroff; /* cached i_diroff value */
324 doff_t i_offset; /* cached i_offset value */
325 int numdirpasses; /* strategy for directory search */
326 doff_t endsearch; /* offset to end directory search */
327 doff_t prevoff; /* prev entry dp->i_offset */
328 struct vnode *pdp; /* saved dp during symlink work */
329 struct vnode *tdp; /* returned by VFS_VGET */
330 doff_t enduseful; /* pointer past last used dir slot */
331 u_long bmask; /* block offset mask */
332 int error;
333 struct ucred *cred = cnp->cn_cred;
334 int flags = cnp->cn_flags;
335 int nameiop = cnp->cn_nameiop;
336 ino_t ino, ino1;
337 int ltype;
338 int entry_found = 0;
339
340 int DIRBLKSIZ = VTOI(vdp)->i_e2fs->e2fs_bsize;
341
342 if (vpp != NULL)
343 *vpp = NULL;
344
345 dp = VTOI(vdp);
346 bmask = VFSTOEXT2(vdp->v_mount)->um_mountp->mnt_stat.f_iosize - 1;
347 restart:
348 bp = NULL;
349 ss.slotoffset = -1;
350
351 /*
352 * We now have a segment name to search for, and a directory to search.
353 *
354 * Suppress search for slots unless creating
355 * file and at end of pathname, in which case
356 * we watch for a place to put the new file in
357 * case it doesn't already exist.
358 */
359 i_diroff = dp->i_diroff;
360 ss.slotstatus = FOUND;
361 ss.slotfreespace = ss.slotsize = ss.slotneeded = 0;
362 if ((nameiop == CREATE || nameiop == RENAME) &&
363 (flags & ISLASTCN)) {
364 ss.slotstatus = NONE;
365 ss.slotneeded = EXT2_DIR_REC_LEN(cnp->cn_namelen);
366 /*
367 * was ss.slotneeded = (sizeof(struct direct) - MAXNAMLEN +
368 * cnp->cn_namelen + 3) &~ 3;
369 */
370 }
371 /*
372 * Try to lookup dir entry using htree directory index.
373 *
374 * If we got an error or we want to find '.' or '..' entry,
375 * we will fall back to linear search.
376 */
377 if (!ext2_is_dot_entry(cnp) && ext2_htree_has_idx(dp)) {
378 numdirpasses = 1;
379 entryoffsetinblock = 0;
380 switch (ext2_htree_lookup(dp, cnp->cn_nameptr, cnp->cn_namelen,
381 &bp, &entryoffsetinblock, &i_offset, &prevoff,
382 &enduseful, &ss)) {
383 case 0:
384 ep = (struct ext2fs_direct_2 *)((char *)bp->b_data +
385 (i_offset & bmask));
386 goto foundentry;
387 case ENOENT:
388 i_offset = roundup2(dp->i_size, DIRBLKSIZ);
389 goto notfound;
390 default:
391 /*
392 * Something failed; just fallback to do a linear
393 * search.
394 */
395 break;
396 }
397 }
398
399 /*
400 * If there is cached information on a previous search of
401 * this directory, pick up where we last left off.
402 * We cache only lookups as these are the most common
403 * and have the greatest payoff. Caching CREATE has little
404 * benefit as it usually must search the entire directory
405 * to determine that the entry does not exist. Caching the
406 * location of the last DELETE or RENAME has not reduced
407 * profiling time and hence has been removed in the interest
408 * of simplicity.
409 */
410 if (nameiop != LOOKUP || i_diroff == 0 ||
411 i_diroff > dp->i_size) {
412 entryoffsetinblock = 0;
413 i_offset = 0;
414 numdirpasses = 1;
415 } else {
416 i_offset = i_diroff;
417 if ((entryoffsetinblock = i_offset & bmask) &&
418 (error = ext2_blkatoff(vdp, (off_t)i_offset, NULL,
419 &bp)))
420 return (error);
421 numdirpasses = 2;
422 nchstats.ncs_2passes++;
423 }
424 prevoff = i_offset;
425 endsearch = roundup2(dp->i_size, DIRBLKSIZ);
426 enduseful = 0;
427
428 searchloop:
429 while (i_offset < endsearch) {
430 /*
431 * If necessary, get the next directory block.
432 */
433 if (bp != NULL)
434 brelse(bp);
435 error = ext2_blkatoff(vdp, (off_t)i_offset, NULL, &bp);
436 if (error != 0)
437 return (error);
438
439 entryoffsetinblock = 0;
440 if (ss.slotstatus == NONE) {
441 ss.slotoffset = -1;
442 ss.slotfreespace = 0;
443 }
444
445 error = ext2_search_dirblock(dp, bp->b_data, &entry_found,
446 cnp->cn_nameptr, cnp->cn_namelen,
447 &entryoffsetinblock, &i_offset, &prevoff,
448 &enduseful, &ss);
449 if (error != 0) {
450 brelse(bp);
451 return (error);
452 }
453 if (entry_found) {
454 ep = (struct ext2fs_direct_2 *)((char *)bp->b_data +
455 (entryoffsetinblock & bmask));
456 foundentry:
457 ino = le32toh(ep->e2d_ino);
458 goto found;
459 }
460 }
461 notfound:
462 /*
463 * If we started in the middle of the directory and failed
464 * to find our target, we must check the beginning as well.
465 */
466 if (numdirpasses == 2) {
467 numdirpasses--;
468 i_offset = 0;
469 endsearch = i_diroff;
470 goto searchloop;
471 }
472 if (bp != NULL)
473 brelse(bp);
474 /*
475 * If creating, and at end of pathname and current
476 * directory has not been removed, then can consider
477 * allowing file to be created.
478 */
479 if ((nameiop == CREATE || nameiop == RENAME) &&
480 (flags & ISLASTCN) && dp->i_nlink != 0) {
481 /*
482 * Access for write is interpreted as allowing
483 * creation of files in the directory.
484 */
485 if ((error = VOP_ACCESS(vdp, VWRITE, cred, curthread)) != 0)
486 return (error);
487 /*
488 * Return an indication of where the new directory
489 * entry should be put. If we didn't find a slot,
490 * then set dp->i_count to 0 indicating
491 * that the new slot belongs at the end of the
492 * directory. If we found a slot, then the new entry
493 * can be put in the range from dp->i_offset to
494 * dp->i_offset + dp->i_count.
495 */
496 if (ss.slotstatus == NONE) {
497 dp->i_offset = roundup2(dp->i_size, DIRBLKSIZ);
498 dp->i_count = 0;
499 enduseful = dp->i_offset;
500 } else {
501 dp->i_offset = ss.slotoffset;
502 dp->i_count = ss.slotsize;
503 if (enduseful < ss.slotoffset + ss.slotsize)
504 enduseful = ss.slotoffset + ss.slotsize;
505 }
506 dp->i_endoff = roundup2(enduseful, DIRBLKSIZ);
507 /*
508 * We return with the directory locked, so that
509 * the parameters we set up above will still be
510 * valid if we actually decide to do a direnter().
511 * We return ni_vp == NULL to indicate that the entry
512 * does not currently exist; we leave a pointer to
513 * the (locked) directory inode in ndp->ni_dvp.
514 *
515 * NB - if the directory is unlocked, then this
516 * information cannot be used.
517 */
518 return (EJUSTRETURN);
519 }
520 /*
521 * Insert name into cache (as non-existent) if appropriate.
522 */
523 if ((cnp->cn_flags & MAKEENTRY) != 0)
524 cache_enter(vdp, NULL, cnp);
525 return (ENOENT);
526
527 found:
528 if (dd_ino != NULL)
529 *dd_ino = ino;
530 if (numdirpasses == 2)
531 nchstats.ncs_pass2++;
532 /*
533 * Check that directory length properly reflects presence
534 * of this entry.
535 */
536 if (entryoffsetinblock + EXT2_DIR_REC_LEN(ep->e2d_namlen) >
537 dp->i_size) {
538 ext2_dirbad(dp, i_offset, "i_size too small");
539 brelse(bp);
540 return (EIO);
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 ((flags & ISLASTCN) && nameiop == LOOKUP)
550 dp->i_diroff = rounddown2(i_offset, DIRBLKSIZ);
551 /*
552 * If deleting, and at end of pathname, return
553 * parameters which can be used to remove file.
554 */
555 if (nameiop == DELETE && (flags & ISLASTCN)) {
556 if (flags & LOCKPARENT)
557 ASSERT_VOP_ELOCKED(vdp, __FUNCTION__);
558 /*
559 * Write access to directory required to delete files.
560 */
561 if ((error = VOP_ACCESS(vdp, VWRITE, cred, curthread)) != 0)
562 return (error);
563 /*
564 * Return pointer to current entry in dp->i_offset,
565 * and distance past previous entry (if there
566 * is a previous entry in this block) in dp->i_count.
567 * Save directory inode pointer in ndp->ni_dvp for dirremove().
568 *
569 * Technically we shouldn't be setting these in the
570 * WANTPARENT case (first lookup in rename()), but any
571 * lookups that will result in directory changes will
572 * overwrite these.
573 */
574 dp->i_offset = i_offset;
575 if ((dp->i_offset & (DIRBLKSIZ - 1)) == 0)
576 dp->i_count = 0;
577 else
578 dp->i_count = dp->i_offset - prevoff;
579 if (dd_ino != NULL)
580 return (0);
581 if (dp->i_number == ino) {
582 VREF(vdp);
583 *vpp = vdp;
584 return (0);
585 }
586 if ((error = VFS_VGET(vdp->v_mount, ino, LK_EXCLUSIVE,
587 &tdp)) != 0)
588 return (error);
589 /*
590 * If directory is "sticky", then user must own
591 * the directory, or the file in it, else she
592 * may not delete it (unless she's root). This
593 * implements append-only directories.
594 */
595 if ((dp->i_mode & ISVTX) &&
596 cred->cr_uid != 0 &&
597 cred->cr_uid != dp->i_uid &&
598 VTOI(tdp)->i_uid != cred->cr_uid) {
599 vput(tdp);
600 return (EPERM);
601 }
602 *vpp = tdp;
603 return (0);
604 }
605
606 /*
607 * If rewriting (RENAME), return the inode and the
608 * information required to rewrite the present directory
609 * Must get inode of directory entry to verify it's a
610 * regular file, or empty directory.
611 */
612 if (nameiop == RENAME && (flags & ISLASTCN)) {
613 if ((error = VOP_ACCESS(vdp, VWRITE, cred, curthread)) != 0)
614 return (error);
615 /*
616 * Careful about locking second inode.
617 * This can only occur if the target is ".".
618 */
619 dp->i_offset = i_offset;
620 if (dp->i_number == ino)
621 return (EISDIR);
622 if (dd_ino != NULL)
623 return (0);
624 if ((error = VFS_VGET(vdp->v_mount, ino, LK_EXCLUSIVE,
625 &tdp)) != 0)
626 return (error);
627 *vpp = tdp;
628 return (0);
629 }
630 if (dd_ino != NULL)
631 return (0);
632
633 /*
634 * Step through the translation in the name. We do not `vput' the
635 * directory because we may need it again if a symbolic link
636 * is relative to the current directory. Instead we save it
637 * unlocked as "pdp". We must get the target inode before unlocking
638 * the directory to insure that the inode will not be removed
639 * before we get it. We prevent deadlock by always fetching
640 * inodes from the root, moving down the directory tree. Thus
641 * when following backward pointers ".." we must unlock the
642 * parent directory before getting the requested directory.
643 * There is a potential race condition here if both the current
644 * and parent directories are removed before the VFS_VGET for the
645 * inode associated with ".." returns. We hope that this occurs
646 * infrequently since we cannot avoid this race condition without
647 * implementing a sophisticated deadlock detection algorithm.
648 * Note also that this simple deadlock detection scheme will not
649 * work if the file system has any hard links other than ".."
650 * that point backwards in the directory structure.
651 */
652 pdp = vdp;
653 if (flags & ISDOTDOT) {
654 error = vn_vget_ino(pdp, ino, cnp->cn_lkflags, &tdp);
655 if (VN_IS_DOOMED(pdp)) {
656 if (error == 0)
657 vput(tdp);
658 error = ENOENT;
659 }
660 if (error)
661 return (error);
662 /*
663 * Recheck that ".." entry in the vdp directory points
664 * to the inode we looked up before vdp lock was
665 * dropped.
666 */
667 error = ext2_lookup_ino(pdp, NULL, cnp, &ino1);
668 if (error) {
669 vput(tdp);
670 return (error);
671 }
672 if (ino1 != ino) {
673 vput(tdp);
674 goto restart;
675 }
676 *vpp = tdp;
677 } else if (dp->i_number == ino) {
678 VREF(vdp); /* we want ourself, ie "." */
679 /*
680 * When we lookup "." we still can be asked to lock it
681 * differently.
682 */
683 ltype = cnp->cn_lkflags & LK_TYPE_MASK;
684 if (ltype != VOP_ISLOCKED(vdp)) {
685 if (ltype == LK_EXCLUSIVE)
686 vn_lock(vdp, LK_UPGRADE | LK_RETRY);
687 else /* if (ltype == LK_SHARED) */
688 vn_lock(vdp, LK_DOWNGRADE | LK_RETRY);
689 }
690 *vpp = vdp;
691 } else {
692 if ((error = VFS_VGET(vdp->v_mount, ino, cnp->cn_lkflags,
693 &tdp)) != 0)
694 return (error);
695 *vpp = tdp;
696 }
697
698 /*
699 * Insert name into cache if appropriate.
700 */
701 if (cnp->cn_flags & MAKEENTRY)
702 cache_enter(vdp, *vpp, cnp);
703 return (0);
704 }
705
706 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)707 ext2_search_dirblock(struct inode *ip, void *data, int *foundp,
708 const char *name, int namelen, int *entryoffsetinblockp,
709 doff_t *offp, doff_t *prevoffp, doff_t *endusefulp,
710 struct ext2fs_searchslot *ssp)
711 {
712 struct vnode *vdp;
713 struct ext2fs_direct_2 *ep, *top;
714 uint32_t bsize = ip->i_e2fs->e2fs_bsize;
715 int offset = *entryoffsetinblockp;
716 int namlen;
717
718 vdp = ITOV(ip);
719
720 ep = (struct ext2fs_direct_2 *)((char *)data + offset);
721 top = (struct ext2fs_direct_2 *)((char *)data + bsize);
722 while (ep < top) {
723 if (ext2_check_direntry(vdp, ep, offset)) {
724 int i;
725
726 ext2_dirbad(ip, *offp, "mangled entry");
727 i = bsize - (offset & (bsize - 1));
728 *offp += i;
729 offset += i;
730 ep = (struct ext2fs_direct_2 *)((char *)data + offset);
731 continue;
732 }
733
734 /*
735 * If an appropriate sized slot has not yet been found,
736 * check to see if one is available. Also accumulate space
737 * in the current block so that we can determine if
738 * compaction is viable.
739 */
740 if (ssp->slotstatus != FOUND) {
741 int size = le16toh(ep->e2d_reclen);
742
743 if (ep->e2d_ino != 0)
744 size -= EXT2_DIR_REC_LEN(ep->e2d_namlen);
745 else if (ext2_is_dirent_tail(ip, ep))
746 size -= sizeof(struct ext2fs_direct_tail);
747 if (size > 0) {
748 if (size >= ssp->slotneeded) {
749 ssp->slotstatus = FOUND;
750 ssp->slotoffset = *offp;
751 ssp->slotsize = le16toh(ep->e2d_reclen);
752 } else if (ssp->slotstatus == NONE) {
753 ssp->slotfreespace += size;
754 if (ssp->slotoffset == -1)
755 ssp->slotoffset = *offp;
756 if (ssp->slotfreespace >= ssp->slotneeded) {
757 ssp->slotstatus = COMPACT;
758 ssp->slotsize = *offp +
759 le16toh(ep->e2d_reclen) -
760 ssp->slotoffset;
761 }
762 }
763 }
764 }
765 /*
766 * Check for a name match.
767 */
768 if (ep->e2d_ino != 0) {
769 namlen = ep->e2d_namlen;
770 if (namlen == namelen &&
771 !bcmp(name, ep->e2d_name, (unsigned)namlen)) {
772 /*
773 * Save directory entry's inode number and
774 * reclen in ndp->ni_ufs area, and release
775 * directory buffer.
776 */
777 *foundp = 1;
778 return (0);
779 }
780 }
781 *prevoffp = *offp;
782 *offp += le16toh(ep->e2d_reclen);
783 offset += le16toh(ep->e2d_reclen);
784 *entryoffsetinblockp = offset;
785 if (ep->e2d_ino != 0)
786 *endusefulp = *offp;
787 /*
788 * Get pointer to the next entry.
789 */
790 ep = (struct ext2fs_direct_2 *)((char *)data + offset);
791 }
792
793 return (0);
794 }
795
796 void
ext2_dirbad(struct inode * ip,doff_t offset,char * how)797 ext2_dirbad(struct inode *ip, doff_t offset, char *how)
798 {
799
800 SDT_PROBE4(ext2fs, , trace, ext2_dirbad_error,
801 ITOV(ip)->v_mount->mnt_stat.f_mntonname, ip->i_number, offset, how);
802 }
803
804 /*
805 * Do consistency checking on a directory entry:
806 * record length must be multiple of 4
807 * entry must fit in rest of its DIRBLKSIZ block
808 * record must be large enough to contain entry
809 * name is not longer than MAXNAMLEN
810 * name must be as long as advertised, and null terminated
811 * inode number less then inode count
812 * if root inode entry, it have correct name
813 */
814 static int
ext2_check_direntry(struct vnode * dp,struct ext2fs_direct_2 * de,int entryoffsetinblock)815 ext2_check_direntry(struct vnode *dp, struct ext2fs_direct_2 *de,
816 int entryoffsetinblock)
817 {
818 struct m_ext2fs *fs = VTOI(dp)->i_e2fs;
819 char *error_msg = NULL;
820
821 if (le16toh(de->e2d_reclen) < EXT2_DIR_REC_LEN(1))
822 error_msg = "rec_len is smaller than minimal";
823 else if (le16toh(de->e2d_reclen) % 4 != 0)
824 error_msg = "rec_len % 4 != 0";
825 else if (le16toh(de->e2d_reclen) < EXT2_DIR_REC_LEN(de->e2d_namlen))
826 error_msg = "reclen is too small for name_len";
827 else if (entryoffsetinblock + le16toh(de->e2d_reclen)> fs->e2fs_bsize)
828 error_msg = "directory entry across blocks";
829 else if (le32toh(de->e2d_ino) > fs->e2fs->e2fs_icount)
830 error_msg = "directory entry inode out of bounds";
831 else if (le32toh(de->e2d_ino) == EXT2_ROOTINO &&
832 ((de->e2d_namlen != 1 && de->e2d_namlen != 2) ||
833 (de->e2d_name[0] != '.') ||
834 (de->e2d_namlen == 2 && de->e2d_name[1] != '.')))
835 error_msg = "bad root directory entry";
836
837 if (error_msg != NULL) {
838 SDT_PROBE5(ext2fs, , trace, ext2_dirbadentry_error,
839 error_msg, entryoffsetinblock,
840 le32toh(de->e2d_ino), le16toh(de->e2d_reclen),
841 de->e2d_namlen);
842 }
843 return (error_msg == NULL ? 0 : EINVAL);
844 }
845
846 /*
847 * Insert an entry into the fresh directory block.
848 * Initialize entry tail if the metadata_csum feature is turned on.
849 */
850 static int
ext2_add_first_entry(struct vnode * dvp,struct ext2fs_direct_2 * entry,struct componentname * cnp)851 ext2_add_first_entry(struct vnode *dvp, struct ext2fs_direct_2 *entry,
852 struct componentname *cnp)
853 {
854 struct inode *dp;
855 struct iovec aiov;
856 struct uio auio;
857 char* buf = NULL;
858 int dirblksize, error;
859
860 dp = VTOI(dvp);
861 dirblksize = dp->i_e2fs->e2fs_bsize;
862
863 if (dp->i_offset & (dirblksize - 1))
864 panic("ext2_add_first_entry: bad directory offset");
865
866 if (EXT2_HAS_RO_COMPAT_FEATURE(dp->i_e2fs,
867 EXT2F_ROCOMPAT_METADATA_CKSUM)) {
868 entry->e2d_reclen = htole16(dirblksize -
869 sizeof(struct ext2fs_direct_tail));
870 buf = malloc(dirblksize, M_TEMP, M_WAITOK);
871 memcpy(buf, entry, EXT2_DIR_REC_LEN(entry->e2d_namlen));
872 ext2_init_dirent_tail(EXT2_DIRENT_TAIL(buf, dirblksize));
873 ext2_dirent_csum_set(dp, (struct ext2fs_direct_2 *)buf);
874
875 auio.uio_offset = dp->i_offset;
876 auio.uio_resid = dirblksize;
877 aiov.iov_len = auio.uio_resid;
878 aiov.iov_base = (caddr_t)buf;
879 } else {
880 entry->e2d_reclen = htole16(dirblksize);
881 auio.uio_offset = dp->i_offset;
882 auio.uio_resid = EXT2_DIR_REC_LEN(entry->e2d_namlen);
883 aiov.iov_len = auio.uio_resid;
884 aiov.iov_base = (caddr_t)entry;
885 }
886
887 auio.uio_iov = &aiov;
888 auio.uio_iovcnt = 1;
889 auio.uio_rw = UIO_WRITE;
890 auio.uio_segflg = UIO_SYSSPACE;
891 auio.uio_td = (struct thread *)0;
892 error = VOP_WRITE(dvp, &auio, IO_SYNC, cnp->cn_cred);
893 if (error)
894 goto out;
895
896 dp->i_size = roundup2(dp->i_size, dirblksize);
897 dp->i_flag |= IN_CHANGE;
898
899 out:
900 free(buf, M_TEMP);
901 return (error);
902
903 }
904
905 /*
906 * Write a directory entry after a call to namei, using the parameters
907 * that it left in nameidata. The argument ip is the inode which the new
908 * directory entry will refer to. Dvp is a pointer to the directory to
909 * be written, which was left locked by namei. Remaining parameters
910 * (dp->i_offset, dp->i_count) indicate how the space for the new
911 * entry is to be obtained.
912 */
913 int
ext2_direnter(struct inode * ip,struct vnode * dvp,struct componentname * cnp)914 ext2_direnter(struct inode *ip, struct vnode *dvp, struct componentname *cnp)
915 {
916 struct inode *dp;
917 struct ext2fs_direct_2 newdir;
918 int DIRBLKSIZ = ip->i_e2fs->e2fs_bsize;
919 int error;
920
921 dp = VTOI(dvp);
922 newdir.e2d_ino = htole32(ip->i_number);
923 if (EXT2_HAS_INCOMPAT_FEATURE(ip->i_e2fs,
924 EXT2F_INCOMPAT_FTYPE)) {
925 newdir.e2d_namlen = cnp->cn_namelen;
926 newdir.e2d_type = DTTOFT(IFTODT(ip->i_mode));
927 } else
928 newdir.e2d_namlen = htole16(cnp->cn_namelen);
929
930 bcopy(cnp->cn_nameptr, newdir.e2d_name, (unsigned)cnp->cn_namelen + 1);
931
932 if (ext2_htree_has_idx(dp)) {
933 error = ext2_htree_add_entry(dvp, &newdir, cnp);
934 if (error) {
935 dp->i_flag &= ~IN_E3INDEX;
936 dp->i_flag |= IN_CHANGE | IN_UPDATE;
937 }
938 return (error);
939 }
940
941 if (EXT2_HAS_COMPAT_FEATURE(ip->i_e2fs, EXT2F_COMPAT_DIRHASHINDEX) &&
942 !ext2_htree_has_idx(dp)) {
943 if ((dp->i_size / DIRBLKSIZ) == 1 &&
944 dp->i_offset == DIRBLKSIZ) {
945 /*
946 * Making indexed directory when one block is not
947 * enough to save all entries.
948 */
949 return ext2_htree_create_index(dvp, cnp, &newdir);
950 }
951 }
952
953 /*
954 * If dp->i_count is 0, then namei could find no
955 * space in the directory. Here, dp->i_offset will
956 * be on a directory block boundary and we will write the
957 * new entry into a fresh block.
958 */
959 if (dp->i_count == 0)
960 return ext2_add_first_entry(dvp, &newdir, cnp);
961
962 error = ext2_add_entry(dvp, &newdir);
963 if (!error && dp->i_endoff && dp->i_endoff < dp->i_size)
964 error = ext2_truncate(dvp, (off_t)dp->i_endoff, IO_SYNC,
965 cnp->cn_cred, curthread);
966 return (error);
967 }
968
969 /*
970 * Insert an entry into the directory block.
971 * Compact the contents.
972 */
973 int
ext2_add_entry(struct vnode * dvp,struct ext2fs_direct_2 * entry)974 ext2_add_entry(struct vnode *dvp, struct ext2fs_direct_2 *entry)
975 {
976 struct ext2fs_direct_2 *ep, *nep;
977 struct inode *dp;
978 struct buf *bp;
979 u_int dsize;
980 int error, loc, newentrysize, spacefree;
981 char *dirbuf;
982
983 dp = VTOI(dvp);
984
985 /*
986 * If dp->i_count is non-zero, then namei found space
987 * for the new entry in the range dp->i_offset to
988 * dp->i_offset + dp->i_count in the directory.
989 * To use this space, we may have to compact the entries located
990 * there, by copying them together towards the beginning of the
991 * block, leaving the free space in one usable chunk at the end.
992 */
993
994 /*
995 * Increase size of directory if entry eats into new space.
996 * This should never push the size past a new multiple of
997 * DIRBLKSIZE.
998 *
999 * N.B. - THIS IS AN ARTIFACT OF 4.2 AND SHOULD NEVER HAPPEN.
1000 */
1001 if (dp->i_offset + dp->i_count > dp->i_size)
1002 dp->i_size = dp->i_offset + dp->i_count;
1003 /*
1004 * Get the block containing the space for the new directory entry.
1005 */
1006 if ((error = ext2_blkatoff(dvp, (off_t)dp->i_offset, &dirbuf,
1007 &bp)) != 0)
1008 return (error);
1009 /*
1010 * Find space for the new entry. In the simple case, the entry at
1011 * offset base will have the space. If it does not, then namei
1012 * arranged that compacting the region dp->i_offset to
1013 * dp->i_offset + dp->i_count would yield the
1014 * space.
1015 */
1016 newentrysize = EXT2_DIR_REC_LEN(entry->e2d_namlen);
1017 ep = (struct ext2fs_direct_2 *)dirbuf;
1018 dsize = EXT2_DIR_REC_LEN(ep->e2d_namlen);
1019 spacefree = le16toh(ep->e2d_reclen) - dsize;
1020 for (loc = le16toh(ep->e2d_reclen); loc < dp->i_count; ) {
1021 nep = (struct ext2fs_direct_2 *)(dirbuf + loc);
1022 if (le32toh(ep->e2d_ino)) {
1023 /* trim the existing slot */
1024 ep->e2d_reclen = htole16(dsize);
1025 ep = (struct ext2fs_direct_2 *)((char *)ep + dsize);
1026 } else {
1027 /* overwrite; nothing there; header is ours */
1028 spacefree += dsize;
1029 }
1030 dsize = EXT2_DIR_REC_LEN(nep->e2d_namlen);
1031 spacefree += le16toh(nep->e2d_reclen) - dsize;
1032 loc += le16toh(nep->e2d_reclen);
1033 bcopy((caddr_t)nep, (caddr_t)ep, dsize);
1034 }
1035 /*
1036 * Update the pointer fields in the previous entry (if any),
1037 * copy in the new entry, and write out the block.
1038 */
1039 if (ep->e2d_ino == 0) {
1040 if (spacefree + dsize < newentrysize)
1041 panic("ext2_direnter: compact1");
1042 entry->e2d_reclen = htole16(spacefree + dsize);
1043 } else {
1044 if (spacefree < newentrysize)
1045 panic("ext2_direnter: compact2");
1046 entry->e2d_reclen = htole16(spacefree);
1047 ep->e2d_reclen = htole16(dsize);
1048 ep = (struct ext2fs_direct_2 *)((char *)ep + dsize);
1049 }
1050 bcopy((caddr_t)entry, (caddr_t)ep, (u_int)newentrysize);
1051 ext2_dirent_csum_set(dp, (struct ext2fs_direct_2 *)bp->b_data);
1052 if (DOINGASYNC(dvp)) {
1053 bdwrite(bp);
1054 error = 0;
1055 } else {
1056 error = bwrite(bp);
1057 }
1058 dp->i_flag |= IN_CHANGE | IN_UPDATE;
1059 return (error);
1060 }
1061
1062 /*
1063 * Remove a directory entry after a call to namei, using
1064 * the parameters which it left in nameidata. The entry
1065 * dp->i_offset contains the offset into the directory of the
1066 * entry to be eliminated. The dp->i_count field contains the
1067 * size of the previous record in the directory. If this
1068 * is 0, the first entry is being deleted, so we need only
1069 * zero the inode number to mark the entry as free. If the
1070 * entry is not the first in the directory, we must reclaim
1071 * the space of the now empty record by adding the record size
1072 * to the size of the previous entry.
1073 */
1074 int
ext2_dirremove(struct vnode * dvp,struct componentname * cnp)1075 ext2_dirremove(struct vnode *dvp, struct componentname *cnp)
1076 {
1077 struct inode *dp;
1078 struct ext2fs_direct_2 *ep, *rep;
1079 struct buf *bp;
1080 int error;
1081
1082 dp = VTOI(dvp);
1083 if (dp->i_count == 0) {
1084 /*
1085 * First entry in block: set d_ino to zero.
1086 */
1087 if ((error =
1088 ext2_blkatoff(dvp, (off_t)dp->i_offset, (char **)&ep,
1089 &bp)) != 0)
1090 return (error);
1091 ep->e2d_ino = 0;
1092 ext2_dirent_csum_set(dp, (struct ext2fs_direct_2 *)bp->b_data);
1093 error = bwrite(bp);
1094 dp->i_flag |= IN_CHANGE | IN_UPDATE;
1095 return (error);
1096 }
1097 /*
1098 * Collapse new free space into previous entry.
1099 */
1100 if ((error = ext2_blkatoff(dvp, (off_t)(dp->i_offset - dp->i_count),
1101 (char **)&ep, &bp)) != 0)
1102 return (error);
1103
1104 /* Set 'rep' to the entry being removed. */
1105 if (dp->i_count == 0)
1106 rep = ep;
1107 else
1108 rep = (struct ext2fs_direct_2 *)((char *)ep +
1109 le16toh(ep->e2d_reclen));
1110 ep->e2d_reclen += rep->e2d_reclen;
1111 ext2_dirent_csum_set(dp, (struct ext2fs_direct_2 *)bp->b_data);
1112 if (DOINGASYNC(dvp) && dp->i_count != 0)
1113 bdwrite(bp);
1114 else
1115 error = bwrite(bp);
1116 dp->i_flag |= IN_CHANGE | IN_UPDATE;
1117 return (error);
1118 }
1119
1120 /*
1121 * Rewrite an existing directory entry to point at the inode
1122 * supplied. The parameters describing the directory entry are
1123 * set up by a call to namei.
1124 */
1125 int
ext2_dirrewrite(struct inode * dp,struct inode * ip,struct componentname * cnp)1126 ext2_dirrewrite(struct inode *dp, struct inode *ip, struct componentname *cnp)
1127 {
1128 struct buf *bp;
1129 struct ext2fs_direct_2 *ep;
1130 struct vnode *vdp = ITOV(dp);
1131 int error;
1132
1133 if ((error = ext2_blkatoff(vdp, (off_t)dp->i_offset, (char **)&ep,
1134 &bp)) != 0)
1135 return (error);
1136 ep->e2d_ino = htole32(ip->i_number);
1137 if (EXT2_HAS_INCOMPAT_FEATURE(ip->i_e2fs,
1138 EXT2F_INCOMPAT_FTYPE))
1139 ep->e2d_type = DTTOFT(IFTODT(ip->i_mode));
1140 else
1141 ep->e2d_type = EXT2_FT_UNKNOWN;
1142 ext2_dirent_csum_set(dp, (struct ext2fs_direct_2 *)bp->b_data);
1143 error = bwrite(bp);
1144 dp->i_flag |= IN_CHANGE | IN_UPDATE;
1145 return (error);
1146 }
1147
1148 /*
1149 * Check if a directory is empty or not.
1150 * Inode supplied must be locked.
1151 *
1152 * Using a struct dirtemplate here is not precisely
1153 * what we want, but better than using a struct direct.
1154 *
1155 * NB: does not handle corrupted directories.
1156 */
1157 int
ext2_dirempty(struct inode * ip,ino_t parentino,struct ucred * cred)1158 ext2_dirempty(struct inode *ip, ino_t parentino, struct ucred *cred)
1159 {
1160 off_t off;
1161 struct dirtemplate dbuf;
1162 struct ext2fs_direct_2 *dp = (struct ext2fs_direct_2 *)&dbuf;
1163 int error, namlen;
1164 ssize_t count;
1165 #define MINDIRSIZ (sizeof(struct dirtemplate) / 2)
1166
1167 for (off = 0; off < ip->i_size; off += le16toh(dp->e2d_reclen)) {
1168 error = vn_rdwr(UIO_READ, ITOV(ip), (caddr_t)dp, MINDIRSIZ,
1169 off, UIO_SYSSPACE, IO_NODELOCKED | IO_NOMACCHECK, cred,
1170 NOCRED, &count, (struct thread *)0);
1171 /*
1172 * Since we read MINDIRSIZ, residual must
1173 * be 0 unless we're at end of file.
1174 */
1175 if (error || count != 0)
1176 return (0);
1177 /* avoid infinite loops */
1178 if (dp->e2d_reclen == 0)
1179 return (0);
1180 /* skip empty entries */
1181 if (dp->e2d_ino == 0)
1182 continue;
1183 /* accept only "." and ".." */
1184 namlen = dp->e2d_namlen;
1185 if (namlen > 2)
1186 return (0);
1187 if (dp->e2d_name[0] != '.')
1188 return (0);
1189 /*
1190 * At this point namlen must be 1 or 2.
1191 * 1 implies ".", 2 implies ".." if second
1192 * char is also "."
1193 */
1194 if (namlen == 1)
1195 continue;
1196 if (dp->e2d_name[1] == '.' && le32toh(dp->e2d_ino) == parentino)
1197 continue;
1198 return (0);
1199 }
1200 return (1);
1201 }
1202
1203 /*
1204 * Check if source directory is in the path of the target directory.
1205 * Target is supplied locked, source is unlocked.
1206 * The target is always vput before returning.
1207 */
1208 int
ext2_checkpath(struct inode * source,struct inode * target,struct ucred * cred)1209 ext2_checkpath(struct inode *source, struct inode *target, struct ucred *cred)
1210 {
1211 struct vnode *vp;
1212 int error, namlen;
1213 struct dirtemplate dirbuf;
1214
1215 vp = ITOV(target);
1216 if (target->i_number == source->i_number) {
1217 error = EEXIST;
1218 goto out;
1219 }
1220 if (target->i_number == EXT2_ROOTINO) {
1221 error = 0;
1222 goto out;
1223 }
1224
1225 for (;;) {
1226 if (vp->v_type != VDIR) {
1227 error = ENOTDIR;
1228 break;
1229 }
1230 error = vn_rdwr(UIO_READ, vp, (caddr_t)&dirbuf,
1231 sizeof(struct dirtemplate), (off_t)0, UIO_SYSSPACE,
1232 IO_NODELOCKED | IO_NOMACCHECK, cred, NOCRED, NULL,
1233 NULL);
1234 if (error != 0)
1235 break;
1236 namlen = dirbuf.dotdot_type; /* like ufs little-endian */
1237 if (namlen != 2 ||
1238 dirbuf.dotdot_name[0] != '.' ||
1239 dirbuf.dotdot_name[1] != '.') {
1240 error = ENOTDIR;
1241 break;
1242 }
1243 if (le32toh(dirbuf.dotdot_ino) == source->i_number) {
1244 error = EINVAL;
1245 break;
1246 }
1247 if (le32toh(dirbuf.dotdot_ino) == EXT2_ROOTINO)
1248 break;
1249 vput(vp);
1250 if ((error = VFS_VGET(vp->v_mount, le32toh(dirbuf.dotdot_ino),
1251 LK_EXCLUSIVE, &vp)) != 0) {
1252 vp = NULL;
1253 break;
1254 }
1255 }
1256
1257 out:
1258 if (error == ENOTDIR)
1259 SDT_PROBE2(ext2fs, , lookup, trace, 1,
1260 "checkpath: .. not a directory");
1261 if (vp != NULL)
1262 vput(vp);
1263 return (error);
1264 }
1265