2 * modified for Lites 1.1
4 * Aug 1995, Godmar Back (gback@cs.utah.edu)
5 * University of Utah, Department of Computer Science
7 * $FreeBSD: src/sys/gnu/ext2fs/ext2_lookup.c,v 1.21.2.3 2002/11/17 02:02:42 bde Exp $
8 * $DragonFly: src/sys/vfs/gnu/ext2fs/ext2_lookup.c,v 1.16 2004/11/12 00:09:30 dillon Exp $
11 * Copyright (c) 1989, 1993
12 * The Regents of the University of California. All rights reserved.
13 * (c) UNIX System Laboratories, Inc.
14 * All or some portions of this file are derived from material licensed
15 * to the University of California by American Telephone and Telegraph
16 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
17 * the permission of UNIX System Laboratories, Inc.
19 * Redistribution and use in source and binary forms, with or without
20 * modification, are permitted provided that the following conditions
22 * 1. Redistributions of source code must retain the above copyright
23 * notice, this list of conditions and the following disclaimer.
24 * 2. Redistributions in binary form must reproduce the above copyright
25 * notice, this list of conditions and the following disclaimer in the
26 * documentation and/or other materials provided with the distribution.
27 * 3. All advertising materials mentioning features or use of this software
28 * must display the following acknowledgement:
29 * This product includes software developed by the University of
30 * California, Berkeley and its contributors.
31 * 4. Neither the name of the University nor the names of its contributors
32 * may be used to endorse or promote products derived from this software
33 * without specific prior written permission.
35 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
36 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
37 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
38 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
39 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
40 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
41 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
42 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
43 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
44 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
47 * @(#)ufs_lookup.c 8.6 (Berkeley) 4/1/94
50 #include <sys/param.h>
51 #include <sys/systm.h>
52 #include <sys/namei.h>
54 #include <sys/mount.h>
55 #include <sys/vnode.h>
56 #include <sys/malloc.h>
57 #include <sys/dirent.h>
59 #include <vfs/ufs/quota.h>
60 #include <vfs/ufs/inode.h>
61 #include <vfs/ufs/dir.h>
62 #include <vfs/ufs/ufsmount.h>
63 #include <vfs/ufs/ufs_extern.h>
65 #include "ext2_extern.h"
67 #include "ext2_fs_sb.h"
70 DIRBLKSIZE in ffs is DEV_BSIZE (in most cases 512)
71 while it is the native blocksize in ext2fs - thus, a #define
72 is no longer appropriate
78 static u_char ext2_ft_to_dt[] = {
79 DT_UNKNOWN, /* EXT2_FT_UNKNOWN */
80 DT_REG, /* EXT2_FT_REG_FILE */
81 DT_DIR, /* EXT2_FT_DIR */
82 DT_CHR, /* EXT2_FT_CHRDEV */
83 DT_BLK, /* EXT2_FT_BLKDEV */
84 DT_FIFO, /* EXT2_FT_FIFO */
85 DT_SOCK, /* EXT2_FT_SOCK */
86 DT_LNK, /* EXT2_FT_SYMLINK */
89 ((ft) > sizeof(ext2_ft_to_dt) / sizeof(ext2_ft_to_dt[0]) ? \
90 DT_UNKNOWN : ext2_ft_to_dt[(ft)])
92 static u_char dt_to_ext2_ft[] = {
93 EXT2_FT_UNKNOWN, /* DT_UNKNOWN */
94 EXT2_FT_FIFO, /* DT_FIFO */
95 EXT2_FT_CHRDEV, /* DT_CHR */
96 EXT2_FT_UNKNOWN, /* unused */
97 EXT2_FT_DIR, /* DT_DIR */
98 EXT2_FT_UNKNOWN, /* unused */
99 EXT2_FT_BLKDEV, /* DT_BLK */
100 EXT2_FT_UNKNOWN, /* unused */
101 EXT2_FT_REG_FILE, /* DT_REG */
102 EXT2_FT_UNKNOWN, /* unused */
103 EXT2_FT_SYMLINK, /* DT_LNK */
104 EXT2_FT_UNKNOWN, /* unused */
105 EXT2_FT_SOCK, /* DT_SOCK */
106 EXT2_FT_UNKNOWN, /* unused */
107 EXT2_FT_UNKNOWN, /* DT_WHT */
110 ((dt) > sizeof(dt_to_ext2_ft) / sizeof(dt_to_ext2_ft[0]) ? \
111 EXT2_FT_UNKNOWN : dt_to_ext2_ft[(dt)])
113 static int ext2_dirbadentry (struct vnode *dp,
114 struct ext2_dir_entry_2 *de,
115 int entryoffsetinblock);
118 * Vnode op for reading directories.
120 * The routine below assumes that the on-disk format of a directory
121 * is the same as that defined by <sys/dirent.h>. If the on-disk
122 * format changes, then it will be necessary to do a conversion
123 * from the on-disk format that read returns to the format defined
127 * this is exactly what we do here - the problem is that the conversion
128 * will blow up some entries by four bytes, so it can't be done in place.
129 * This is too bad. Right now the conversion is done entry by entry, the
130 * converted entry is sent via uiomove.
132 * XXX allocate a buffer, convert as many entries as possible, then send
133 * the whole buffer to uiomove
135 * ext2_readdir(struct vnode *a_vp, struct uio *a_uio, struct ucred *a_cred)
138 ext2_readdir(struct vop_readdir_args *ap)
140 struct uio *uio = ap->a_uio;
143 struct ext2_dir_entry_2 *edp, *dp;
149 int DIRBLKSIZ = VTOI(ap->a_vp)->i_e2fs->s_blocksize;
151 off_t startoffset = uio->uio_offset;
153 count = uio->uio_resid;
155 * Avoid complications for partial directory entries by adjusting
156 * the i/o to end at a block boundary. Don't give up (like ufs
157 * does) if the initial adjustment gives a negative count, since
158 * many callers don't supply a large enough buffer. The correct
159 * size is a little larger than DIRBLKSIZ to allow for expansion
160 * of directory entries, but some callers just use 512.
162 count -= (uio->uio_offset + count) & (DIRBLKSIZ -1);
167 printf("ext2_readdir: uio_offset = %lld, uio_resid = %d, count = %d\n",
168 uio->uio_offset, uio->uio_resid, count);
172 auio.uio_iov = &aiov;
174 auio.uio_resid = count;
175 auio.uio_segflg = UIO_SYSSPACE;
176 aiov.iov_len = count;
177 MALLOC(dirbuf, caddr_t, count, M_TEMP, M_WAITOK);
178 aiov.iov_base = dirbuf;
179 error = VOP_READ(ap->a_vp, &auio, 0, ap->a_cred);
181 readcnt = count - auio.uio_resid;
182 edp = (struct ext2_dir_entry_2 *)&dirbuf[readcnt];
184 bzero(&dstdp, offsetof(struct dirent, d_name));
185 for (dp = (struct ext2_dir_entry_2 *)dirbuf;
186 !error && uio->uio_resid > 0 && dp < edp; ) {
188 * "New" ext2fs directory entries differ in 3 ways
189 * from ufs on-disk ones:
190 * - the name is not necessarily NUL-terminated.
191 * - the file type field always exists and always
192 * follows the name length field.
193 * - the file type is encoded in a different way.
195 * "Old" ext2fs directory entries need no special
196 * conversions, since they binary compatible with
197 * "new" entries having a file type of 0 (i.e.,
198 * EXT2_FT_UNKNOWN). Splitting the old name length
199 * field didn't make a mess like it did in ufs,
200 * because ext2fs uses a machine-dependent disk
203 dstdp.d_fileno = dp->inode;
204 dstdp.d_type = FTTODT(dp->file_type);
205 dstdp.d_namlen = dp->name_len;
206 dstdp.d_reclen = GENERIC_DIRSIZ(&dstdp);
207 bcopy(dp->name, dstdp.d_name, dstdp.d_namlen);
208 bzero(dstdp.d_name + dstdp.d_namlen,
209 dstdp.d_reclen - offsetof(struct dirent, d_name) -
212 if (dp->rec_len > 0) {
213 if(dstdp.d_reclen <= uio->uio_resid) {
215 dp = (struct ext2_dir_entry_2 *)
216 ((char *)dp + dp->rec_len);
218 uiomove((caddr_t)&dstdp,
219 dstdp.d_reclen, uio);
229 /* we need to correct uio_offset */
230 uio->uio_offset = startoffset + (caddr_t)dp - dirbuf;
232 if (!error && ap->a_ncookies != NULL) {
233 u_long *cookiep, *cookies, *ecookies;
236 if (uio->uio_segflg != UIO_SYSSPACE || uio->uio_iovcnt != 1)
237 panic("ext2fs_readdir: unexpected uio from NFS server");
238 MALLOC(cookies, u_long *, ncookies * sizeof(u_long), M_TEMP,
241 for (dp = (struct ext2_dir_entry_2 *)dirbuf,
242 cookiep = cookies, ecookies = cookies + ncookies;
244 dp = (struct ext2_dir_entry_2 *)((caddr_t) dp + dp->rec_len)) {
246 *cookiep++ = (u_long) off;
248 *ap->a_ncookies = ncookies;
249 *ap->a_cookies = cookies;
252 FREE(dirbuf, M_TEMP);
254 *ap->a_eofflag = VTOI(ap->a_vp)->i_size <= uio->uio_offset;
259 * Convert a component of a pathname into a pointer to a locked inode.
260 * This is a very central and rather complicated routine.
261 * If the file system is not maintained in a strict tree hierarchy,
262 * this can result in a deadlock situation (see comments in code below).
264 * The cnp->cn_nameiop argument is LOOKUP, CREATE, RENAME, or DELETE depending
265 * on whether the name is to be looked up, created, renamed, or deleted.
266 * When CREATE, RENAME, or DELETE is specified, information usable in
267 * creating, renaming, or deleting a directory entry may be calculated.
268 * If flag has LOCKPARENT or'ed into it and the target of the pathname
269 * exists, lookup returns both the target and its parent directory locked.
270 * When creating or renaming and LOCKPARENT is specified, the target may
271 * not be ".". When deleting and LOCKPARENT is specified, the target may
272 * be "."., but the caller must check to ensure it does an vrele and vput
273 * instead of two vputs.
275 * Overall outline of ufs_lookup:
277 * search for name in directory, to found or notfound
279 * if creating, return locked directory, leaving info on available slots
282 * if at end of path and deleting, return information to allow delete
283 * if at end of path and rewriting (RENAME and LOCKPARENT), lock target
284 * inode and return info to allow rewrite
285 * if not at end, add name to cache; if at end and neither creating
286 * nor deleting, add name to cache
288 * ext2_lookup(struct vnode *a_dvp, struct vnode **a_vpp,
289 * struct componentname *a_cnp)
292 ext2_lookup(struct vop_lookup_args *ap)
294 struct vnode *vdp; /* vnode for directory being searched */
295 struct inode *dp; /* inode for directory being searched */
296 struct buf *bp; /* a buffer of directory entries */
297 struct ext2_dir_entry_2 *ep; /* the current directory entry */
298 int entryoffsetinblock; /* offset of ep in bp's buffer */
299 enum {NONE, COMPACT, FOUND} slotstatus;
300 doff_t slotoffset; /* offset of area with free space */
301 int slotsize; /* size of area at slotoffset */
302 int slotfreespace; /* amount of space free in slot */
303 int slotneeded; /* size of the entry we're seeking */
304 int numdirpasses; /* strategy for directory search */
305 doff_t endsearch; /* offset to end directory search */
306 doff_t prevoff; /* prev entry dp->i_offset */
307 struct vnode *pdp; /* saved dp during symlink work */
308 struct vnode *tdp; /* returned by VFS_VGET */
309 doff_t enduseful; /* pointer past last used dir slot */
310 u_long bmask; /* block offset mask */
311 int lockparent; /* 1 => lockparent flag is set */
312 int wantparent; /* 1 => wantparent or lockparent flag */
314 struct vnode **vpp = ap->a_vpp;
315 struct componentname *cnp = ap->a_cnp;
316 struct ucred *cred = cnp->cn_cred;
317 int flags = cnp->cn_flags;
318 int nameiop = cnp->cn_nameiop;
319 struct thread *td = cnp->cn_td;
320 globaldata_t gd = mycpu;
322 int DIRBLKSIZ = VTOI(ap->a_dvp)->i_e2fs->s_blocksize;
329 lockparent = flags & CNP_LOCKPARENT;
330 wantparent = flags & (CNP_LOCKPARENT|CNP_WANTPARENT);
333 * We now have a segment name to search for, and a directory to search.
337 * Suppress search for slots unless creating
338 * file and at end of pathname, in which case
339 * we watch for a place to put the new file in
340 * case it doesn't already exist.
343 slotfreespace = slotsize = slotneeded = 0;
344 if (nameiop == NAMEI_CREATE || nameiop == NAMEI_RENAME) {
346 slotneeded = EXT2_DIR_REC_LEN(cnp->cn_namelen);
348 slotneeded = (sizeof(struct direct) - MAXNAMLEN +
349 cnp->cn_namelen + 3) &~ 3; */
353 * If there is cached information on a previous search of
354 * this directory, pick up where we last left off.
355 * We cache only lookups as these are the most common
356 * and have the greatest payoff. Caching CREATE has little
357 * benefit as it usually must search the entire directory
358 * to determine that the entry does not exist. Caching the
359 * location of the last DELETE or RENAME has not reduced
360 * profiling time and hence has been removed in the interest
363 bmask = VFSTOUFS(vdp->v_mount)->um_mountp->mnt_stat.f_iosize - 1;
364 if (nameiop != NAMEI_LOOKUP || dp->i_diroff == 0 ||
365 dp->i_diroff > dp->i_size) {
366 entryoffsetinblock = 0;
370 dp->i_offset = dp->i_diroff;
371 if ((entryoffsetinblock = dp->i_offset & bmask) &&
372 (error = UFS_BLKATOFF(vdp, (off_t)dp->i_offset, NULL, &bp)))
375 gd->gd_nchstats->ncs_2passes++;
377 prevoff = dp->i_offset;
378 endsearch = roundup(dp->i_size, DIRBLKSIZ);
382 while (dp->i_offset < endsearch) {
384 * If necessary, get the next directory block.
386 if ((dp->i_offset & bmask) == 0) {
390 UFS_BLKATOFF(vdp, (off_t)dp->i_offset, NULL, &bp)) != 0)
392 entryoffsetinblock = 0;
395 * If still looking for a slot, and at a DIRBLKSIZE
396 * boundary, have to start looking for free space again.
398 if (slotstatus == NONE &&
399 (entryoffsetinblock & (DIRBLKSIZ - 1)) == 0) {
404 * Get pointer to next entry.
405 * Full validation checks are slow, so we only check
406 * enough to insure forward progress through the
407 * directory. Complete checks can be run by patching
408 * "dirchk" to be true.
410 ep = (struct ext2_dir_entry_2 *)
411 ((char *)bp->b_data + entryoffsetinblock);
412 if (ep->rec_len == 0 ||
413 (dirchk && ext2_dirbadentry(vdp, ep, entryoffsetinblock))) {
415 ufs_dirbad(dp, dp->i_offset, "mangled entry");
416 i = DIRBLKSIZ - (entryoffsetinblock & (DIRBLKSIZ - 1));
418 entryoffsetinblock += i;
423 * If an appropriate sized slot has not yet been found,
424 * check to see if one is available. Also accumulate space
425 * in the current block so that we can determine if
426 * compaction is viable.
428 if (slotstatus != FOUND) {
429 int size = ep->rec_len;
432 size -= EXT2_DIR_REC_LEN(ep->name_len);
434 if (size >= slotneeded) {
436 slotoffset = dp->i_offset;
437 slotsize = ep->rec_len;
438 } else if (slotstatus == NONE) {
439 slotfreespace += size;
440 if (slotoffset == -1)
441 slotoffset = dp->i_offset;
442 if (slotfreespace >= slotneeded) {
443 slotstatus = COMPACT;
444 slotsize = dp->i_offset +
445 ep->rec_len - slotoffset;
452 * Check for a name match.
455 namlen = ep->name_len;
456 if (namlen == cnp->cn_namelen &&
457 !bcmp(cnp->cn_nameptr, ep->name,
460 * Save directory entry's inode number and
461 * reclen in ndp->ni_ufs area, and release
464 dp->i_ino = ep->inode;
465 dp->i_reclen = ep->rec_len;
469 prevoff = dp->i_offset;
470 dp->i_offset += ep->rec_len;
471 entryoffsetinblock += ep->rec_len;
473 enduseful = dp->i_offset;
477 * If we started in the middle of the directory and failed
478 * to find our target, we must check the beginning as well.
480 if (numdirpasses == 2) {
483 endsearch = dp->i_diroff;
489 * If creating, and at end of pathname and current
490 * directory has not been removed, then can consider
491 * allowing file to be created.
493 if ((nameiop == NAMEI_CREATE || nameiop == NAMEI_RENAME) &&
496 * Access for write is interpreted as allowing
497 * creation of files in the directory.
499 if ((error = VOP_ACCESS(vdp, VWRITE, cred, cnp->cn_td)) != 0)
502 * Return an indication of where the new directory
503 * entry should be put. If we didn't find a slot,
504 * then set dp->i_count to 0 indicating
505 * that the new slot belongs at the end of the
506 * directory. If we found a slot, then the new entry
507 * can be put in the range from dp->i_offset to
508 * dp->i_offset + dp->i_count.
510 if (slotstatus == NONE) {
511 dp->i_offset = roundup(dp->i_size, DIRBLKSIZ);
513 enduseful = dp->i_offset;
515 dp->i_offset = slotoffset;
516 dp->i_count = slotsize;
517 if (enduseful < slotoffset + slotsize)
518 enduseful = slotoffset + slotsize;
520 dp->i_endoff = roundup(enduseful, DIRBLKSIZ);
521 dp->i_flag |= IN_CHANGE | IN_UPDATE;
523 * We return with the directory locked, so that
524 * the parameters we set up above will still be
525 * valid if we actually decide to do a direnter().
526 * We return ni_vp == NULL to indicate that the entry
527 * does not currently exist; we leave a pointer to
528 * the (locked) directory inode in ndp->ni_dvp.
529 * The pathname buffer is saved so that the name
530 * can be obtained later.
532 * NB - if the directory is unlocked, then this
533 * information cannot be used.
536 VOP_UNLOCK(vdp, 0, td);
537 return (EJUSTRETURN);
542 if (numdirpasses == 2)
543 gd->gd_nchstats->ncs_pass2++;
545 * Check that directory length properly reflects presence
548 if (entryoffsetinblock + EXT2_DIR_REC_LEN(ep->name_len)
550 ufs_dirbad(dp, dp->i_offset, "i_size too small");
551 dp->i_size = entryoffsetinblock+EXT2_DIR_REC_LEN(ep->name_len);
552 dp->i_flag |= IN_CHANGE | IN_UPDATE;
557 * Found component in pathname.
558 * If the final component of path name, save information
559 * in the cache as to where the entry was found.
561 if (nameiop == NAMEI_LOOKUP)
562 dp->i_diroff = dp->i_offset &~ (DIRBLKSIZ - 1);
565 * If deleting, and at end of pathname, return
566 * parameters which can be used to remove file.
567 * If the wantparent flag isn't set, we return only
568 * the directory (in ndp->ni_dvp), otherwise we go
569 * on and lock the inode, being careful with ".".
571 if (nameiop == NAMEI_DELETE) {
573 * Write access to directory required to delete files.
575 if ((error = VOP_ACCESS(vdp, VWRITE, cred, cnp->cn_td)) != 0)
578 * Return pointer to current entry in dp->i_offset,
579 * and distance past previous entry (if there
580 * is a previous entry in this block) in dp->i_count.
581 * Save directory inode pointer in ndp->ni_dvp for dirremove().
583 if ((dp->i_offset & (DIRBLKSIZ - 1)) == 0)
586 dp->i_count = dp->i_offset - prevoff;
587 if (dp->i_number == dp->i_ino) {
592 if ((error = VFS_VGET(vdp->v_mount, dp->i_ino, &tdp)) != 0)
595 * If directory is "sticky", then user must own
596 * the directory, or the file in it, else she
597 * may not delete it (unless she's root). This
598 * implements append-only directories.
600 if ((dp->i_mode & ISVTX) &&
602 cred->cr_uid != dp->i_uid &&
603 VTOI(tdp)->i_uid != cred->cr_uid) {
609 VOP_UNLOCK(vdp, 0, td);
614 * If rewriting (RENAME), return the inode and the
615 * information required to rewrite the present directory
616 * Must get inode of directory entry to verify it's a
617 * regular file, or empty directory.
619 if (nameiop == NAMEI_RENAME && wantparent) {
620 if ((error = VOP_ACCESS(vdp, VWRITE, cred, cnp->cn_td)) != 0)
623 * Careful about locking second inode.
624 * This can only occur if the target is ".".
626 if (dp->i_number == dp->i_ino)
628 if ((error = VFS_VGET(vdp->v_mount, dp->i_ino, &tdp)) != 0)
632 VOP_UNLOCK(vdp, 0, td);
637 * Step through the translation in the name. We do not `vput' the
638 * directory because we may need it again if a symbolic link
639 * is relative to the current directory. Instead we save it
640 * unlocked as "pdp". We must get the target inode before unlocking
641 * the directory to insure that the inode will not be removed
642 * before we get it. We prevent deadlock by always fetching
643 * inodes from the root, moving down the directory tree. Thus
644 * when following backward pointers ".." we must unlock the
645 * parent directory before getting the requested directory.
646 * There is a potential race condition here if both the current
647 * and parent directories are removed before the VFS_VGET for the
648 * inode associated with ".." returns. We hope that this occurs
649 * infrequently since we cannot avoid this race condition without
650 * implementing a sophisticated deadlock detection algorithm.
651 * Note also that this simple deadlock detection scheme will not
652 * work if the file system has any hard links other than ".."
653 * that point backwards in the directory structure.
656 if (flags & CNP_ISDOTDOT) {
657 VOP_UNLOCK(pdp, 0, td); /* race to get the inode */
658 if ((error = VFS_VGET(vdp->v_mount, dp->i_ino, &tdp)) != 0) {
659 vn_lock(pdp, LK_EXCLUSIVE | LK_RETRY, td);
662 if (lockparent && (error = vn_lock(pdp, LK_EXCLUSIVE, td))) {
667 } else if (dp->i_number == dp->i_ino) {
668 vref(vdp); /* we want ourself, ie "." */
671 if ((error = VFS_VGET(vdp->v_mount, dp->i_ino, &tdp)) != 0)
674 VOP_UNLOCK(pdp, 0, td);
681 * Do consistency checking on a directory entry:
682 * record length must be multiple of 4
683 * entry must fit in rest of its DIRBLKSIZ block
684 * record must be large enough to contain entry
685 * name is not longer than MAXNAMLEN
686 * name must be as long as advertised, and null terminated
689 * changed so that it confirms to ext2_check_dir_entry
692 ext2_dirbadentry(struct vnode *dp, struct ext2_dir_entry_2 *de,
693 int entryoffsetinblock)
695 int DIRBLKSIZ = VTOI(dp)->i_e2fs->s_blocksize;
697 char * error_msg = NULL;
699 if (de->rec_len < EXT2_DIR_REC_LEN(1))
700 error_msg = "rec_len is smaller than minimal";
701 else if (de->rec_len % 4 != 0)
702 error_msg = "rec_len % 4 != 0";
703 else if (de->rec_len < EXT2_DIR_REC_LEN(de->name_len))
704 error_msg = "reclen is too small for name_len";
705 else if (entryoffsetinblock + de->rec_len > DIRBLKSIZ)
706 error_msg = "directory entry across blocks";
708 if (de->inode > dir->i_sb->u.ext2_sb.s_es->s_inodes_count)
709 error_msg = "inode out of bounds";
712 if (error_msg != NULL) {
713 printf("bad directory entry: %s\n", error_msg);
714 printf("offset=%d, inode=%lu, rec_len=%u, name_len=%u\n",
715 entryoffsetinblock, (unsigned long)de->inode,
716 de->rec_len, de->name_len);
718 return error_msg == NULL ? 0 : 1;
722 * Write a directory entry after a call to namei, using the parameters
723 * that it left in the directory inode. The argument ip is the inode which
724 * the new directory entry will refer to. Dvp is a pointer to the directory
725 * to be written, which was left locked by namei. Remaining parameters
726 * (dp->i_offset, dp->i_count) indicate how the space for the new
727 * entry is to be obtained.
730 ext2_direnter(struct inode *ip, struct vnode *dvp, struct componentname *cnp)
732 struct ext2_dir_entry_2 *ep, *nep;
735 struct ext2_dir_entry_2 newdir;
739 int error, loc, newentrysize, spacefree;
741 int DIRBLKSIZ = ip->i_e2fs->s_blocksize;
745 newdir.inode = ip->i_number;
746 newdir.name_len = cnp->cn_namelen;
747 if (EXT2_HAS_INCOMPAT_FEATURE(ip->i_e2fs->s_es,
748 EXT2_FEATURE_INCOMPAT_FILETYPE))
749 newdir.file_type = DTTOFT(IFTODT(ip->i_mode));
751 newdir.file_type = EXT2_FT_UNKNOWN;
752 bcopy(cnp->cn_nameptr, newdir.name, (unsigned)cnp->cn_namelen + 1);
753 newentrysize = EXT2_DIR_REC_LEN(newdir.name_len);
754 if (dp->i_count == 0) {
756 * If dp->i_count is 0, then namei could find no
757 * space in the directory. Here, dp->i_offset will
758 * be on a directory block boundary and we will write the
759 * new entry into a fresh block.
761 if (dp->i_offset & (DIRBLKSIZ - 1))
762 panic("ext2_direnter: newblk");
763 auio.uio_offset = dp->i_offset;
764 newdir.rec_len = DIRBLKSIZ;
765 auio.uio_resid = newentrysize;
766 aiov.iov_len = newentrysize;
767 aiov.iov_base = (caddr_t)&newdir;
768 auio.uio_iov = &aiov;
770 auio.uio_rw = UIO_WRITE;
771 auio.uio_segflg = UIO_SYSSPACE;
773 error = VOP_WRITE(dvp, &auio, IO_SYNC, cnp->cn_cred);
775 VFSTOUFS(dvp->v_mount)->um_mountp->mnt_stat.f_bsize)
776 /* XXX should grow with balloc() */
777 panic("ext2_direnter: frag size");
779 dp->i_size = roundup(dp->i_size, DIRBLKSIZ);
780 dp->i_flag |= IN_CHANGE;
786 * If dp->i_count is non-zero, then namei found space
787 * for the new entry in the range dp->i_offset to
788 * dp->i_offset + dp->i_count in the directory.
789 * To use this space, we may have to compact the entries located
790 * there, by copying them together towards the beginning of the
791 * block, leaving the free space in one usable chunk at the end.
795 * Increase size of directory if entry eats into new space.
796 * This should never push the size past a new multiple of
799 * N.B. - THIS IS AN ARTIFACT OF 4.2 AND SHOULD NEVER HAPPEN.
801 if (dp->i_offset + dp->i_count > dp->i_size)
802 dp->i_size = dp->i_offset + dp->i_count;
804 * Get the block containing the space for the new directory entry.
806 if ((error = UFS_BLKATOFF(dvp, (off_t)dp->i_offset, &dirbuf, &bp)) != 0)
809 * Find space for the new entry. In the simple case, the entry at
810 * offset base will have the space. If it does not, then namei
811 * arranged that compacting the region dp->i_offset to
812 * dp->i_offset + dp->i_count would yield the
815 ep = (struct ext2_dir_entry_2 *)dirbuf;
816 dsize = EXT2_DIR_REC_LEN(ep->name_len);
817 spacefree = ep->rec_len - dsize;
818 for (loc = ep->rec_len; loc < dp->i_count; ) {
819 nep = (struct ext2_dir_entry_2 *)(dirbuf + loc);
821 /* trim the existing slot */
823 ep = (struct ext2_dir_entry_2 *)((char *)ep + dsize);
825 /* overwrite; nothing there; header is ours */
828 dsize = EXT2_DIR_REC_LEN(nep->name_len);
829 spacefree += nep->rec_len - dsize;
831 bcopy((caddr_t)nep, (caddr_t)ep, dsize);
834 * Update the pointer fields in the previous entry (if any),
835 * copy in the new entry, and write out the block.
837 if (ep->inode == 0) {
838 if (spacefree + dsize < newentrysize)
839 panic("ext2_direnter: compact1");
840 newdir.rec_len = spacefree + dsize;
842 if (spacefree < newentrysize)
843 panic("ext2_direnter: compact2");
844 newdir.rec_len = spacefree;
846 ep = (struct ext2_dir_entry_2 *)((char *)ep + dsize);
848 bcopy((caddr_t)&newdir, (caddr_t)ep, (u_int)newentrysize);
849 error = VOP_BWRITE(bp->b_vp, bp);
850 dp->i_flag |= IN_CHANGE | IN_UPDATE;
851 if (!error && dp->i_endoff && dp->i_endoff < dp->i_size)
852 error = UFS_TRUNCATE(dvp, (off_t)dp->i_endoff, IO_SYNC,
853 cnp->cn_cred, cnp->cn_td);
858 * Remove a directory entry after a call to namei, using
859 * the parameters which it left in the directory inode. The entry
860 * dp->i_offset contains the offset into the directory of the
861 * entry to be eliminated. The dp->i_count field contains the
862 * size of the previous record in the directory. If this
863 * is 0, the first entry is being deleted, so we need only
864 * zero the inode number to mark the entry as free. If the
865 * entry is not the first in the directory, we must reclaim
866 * the space of the now empty record by adding the record size
867 * to the size of the previous entry.
870 ext2_dirremove(struct vnode *dvp, struct componentname *cnp)
873 struct ext2_dir_entry_2 *ep;
878 if (dp->i_count == 0) {
880 * First entry in block: set d_ino to zero.
883 UFS_BLKATOFF(dvp, (off_t)dp->i_offset, (char **)&ep, &bp)) != 0)
886 error = VOP_BWRITE(bp->b_vp, bp);
887 dp->i_flag |= IN_CHANGE | IN_UPDATE;
891 * Collapse new free space into previous entry.
893 if ((error = UFS_BLKATOFF(dvp, (off_t)(dp->i_offset - dp->i_count),
894 (char **)&ep, &bp)) != 0)
896 ep->rec_len += dp->i_reclen;
897 error = VOP_BWRITE(bp->b_vp, bp);
898 dp->i_flag |= IN_CHANGE | IN_UPDATE;
903 * Rewrite an existing directory entry to point at the inode
904 * supplied. The parameters describing the directory entry are
905 * set up by a call to namei.
908 ext2_dirrewrite(struct inode *dp, struct inode *ip, struct componentname *cnp)
911 struct ext2_dir_entry_2 *ep;
912 struct vnode *vdp = ITOV(dp);
915 if ((error = UFS_BLKATOFF(vdp, (off_t)dp->i_offset, (char **)&ep, &bp)) != 0)
917 ep->inode = ip->i_number;
918 if (EXT2_HAS_INCOMPAT_FEATURE(ip->i_e2fs->s_es,
919 EXT2_FEATURE_INCOMPAT_FILETYPE))
920 ep->file_type = DTTOFT(IFTODT(ip->i_mode));
922 ep->file_type = EXT2_FT_UNKNOWN;
923 error = VOP_BWRITE(bp->b_vp, bp);
924 dp->i_flag |= IN_CHANGE | IN_UPDATE;
929 * Check if a directory is empty or not.
930 * Inode supplied must be locked.
932 * Using a struct dirtemplate here is not precisely
933 * what we want, but better than using a struct direct.
935 * NB: does not handle corrupted directories.
938 ext2_dirempty(struct inode *ip, ino_t parentino, struct ucred *cred)
941 struct dirtemplate dbuf;
942 struct ext2_dir_entry_2 *dp = (struct ext2_dir_entry_2 *)&dbuf;
943 int error, count, namlen;
945 #define MINDIRSIZ (sizeof (struct dirtemplate) / 2)
947 for (off = 0; off < ip->i_size; off += dp->rec_len) {
948 error = vn_rdwr(UIO_READ, ITOV(ip), (caddr_t)dp, MINDIRSIZ, off,
949 UIO_SYSSPACE, IO_NODELOCKED, cred, &count, NULL);
951 * Since we read MINDIRSIZ, residual must
952 * be 0 unless we're at end of file.
954 if (error || count != 0)
956 /* avoid infinite loops */
957 if (dp->rec_len == 0)
959 /* skip empty entries */
962 /* accept only "." and ".." */
963 namlen = dp->name_len;
966 if (dp->name[0] != '.')
969 * At this point namlen must be 1 or 2.
970 * 1 implies ".", 2 implies ".." if second
975 if (dp->name[1] == '.' && dp->inode == parentino)
983 * Check if source directory is in the path of the target directory.
984 * Target is supplied locked, source is unlocked.
985 * The target is always vput before returning.
988 ext2_checkpath(struct inode *source, struct inode *target, struct ucred *cred)
991 int error, rootino, namlen;
992 struct dirtemplate dirbuf;
995 if (target->i_number == source->i_number) {
1001 if (target->i_number == rootino)
1005 if (vp->v_type != VDIR) {
1009 error = vn_rdwr(UIO_READ, vp, (caddr_t)&dirbuf,
1010 sizeof (struct dirtemplate), (off_t)0, UIO_SYSSPACE,
1011 IO_NODELOCKED, cred, (int *)0, NULL);
1014 namlen = dirbuf.dotdot_type; /* like ufs little-endian */
1016 dirbuf.dotdot_name[0] != '.' ||
1017 dirbuf.dotdot_name[1] != '.') {
1021 if (dirbuf.dotdot_ino == source->i_number) {
1025 if (dirbuf.dotdot_ino == rootino)
1028 if ((error = VFS_VGET(vp->v_mount, dirbuf.dotdot_ino, &vp)) != 0) {
1035 if (error == ENOTDIR)
1036 printf("checkpath: .. not a directory\n");