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 $
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.
18 * Redistribution and use in source and binary forms, with or without
19 * modification, are permitted provided that the following conditions
21 * 1. Redistributions of source code must retain the above copyright
22 * notice, this list of conditions and the following disclaimer.
23 * 2. Redistributions in binary form must reproduce the above copyright
24 * notice, this list of conditions and the following disclaimer in the
25 * documentation and/or other materials provided with the distribution.
26 * 3. All advertising materials mentioning features or use of this software
27 * must display the following acknowledgement:
28 * This product includes software developed by the University of
29 * California, Berkeley and its contributors.
30 * 4. Neither the name of the University nor the names of its contributors
31 * may be used to endorse or promote products derived from this software
32 * without specific prior written permission.
34 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
35 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
36 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
37 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
38 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
39 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
40 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
41 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
42 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
43 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
46 * @(#)ufs_lookup.c 8.6 (Berkeley) 4/1/94
49 #include <sys/param.h>
50 #include <sys/systm.h>
51 #include <sys/namei.h>
53 #include <sys/mount.h>
54 #include <sys/vnode.h>
55 #include <sys/malloc.h>
56 #include <sys/dirent.h>
61 #include "ext2mount.h"
62 #include "ext2_extern.h"
64 #include "ext2_fs_sb.h"
67 DIRBLKSIZE in ffs is DEV_BSIZE (in most cases 512)
68 while it is the native blocksize in ext2fs - thus, a #define
69 is no longer appropriate
75 static u_char ext2_ft_to_dt[] = {
76 DT_UNKNOWN, /* EXT2_FT_UNKNOWN */
77 DT_REG, /* EXT2_FT_REG_FILE */
78 DT_DIR, /* EXT2_FT_DIR */
79 DT_CHR, /* EXT2_FT_CHRDEV */
80 DT_BLK, /* EXT2_FT_BLKDEV */
81 DT_FIFO, /* EXT2_FT_FIFO */
82 DT_SOCK, /* EXT2_FT_SOCK */
83 DT_LNK, /* EXT2_FT_SYMLINK */
86 ((ft) > NELEM(ext2_ft_to_dt) ? \
87 DT_UNKNOWN : ext2_ft_to_dt[(ft)])
89 static u_char dt_to_ext2_ft[] = {
90 EXT2_FT_UNKNOWN, /* DT_UNKNOWN */
91 EXT2_FT_FIFO, /* DT_FIFO */
92 EXT2_FT_CHRDEV, /* DT_CHR */
93 EXT2_FT_UNKNOWN, /* unused */
94 EXT2_FT_DIR, /* DT_DIR */
95 EXT2_FT_UNKNOWN, /* unused */
96 EXT2_FT_BLKDEV, /* DT_BLK */
97 EXT2_FT_UNKNOWN, /* unused */
98 EXT2_FT_REG_FILE, /* DT_REG */
99 EXT2_FT_UNKNOWN, /* unused */
100 EXT2_FT_SYMLINK, /* DT_LNK */
101 EXT2_FT_UNKNOWN, /* unused */
102 EXT2_FT_SOCK, /* DT_SOCK */
103 EXT2_FT_UNKNOWN, /* unused */
104 EXT2_FT_UNKNOWN, /* DT_WHT */
107 ((dt) > NELEM(dt_to_ext2_ft) ? \
108 EXT2_FT_UNKNOWN : dt_to_ext2_ft[(dt)])
110 static int ext2_dirbadentry (struct vnode *dp,
111 struct ext2_dir_entry_2 *de,
112 int entryoffsetinblock);
115 * Vnode op for reading directories.
117 * The routine below assumes that the on-disk format of a directory
118 * is the same as that defined by <sys/dirent.h>. If the on-disk
119 * format changes, then it will be necessary to do a conversion
120 * from the on-disk format that read returns to the format defined
124 * this is exactly what we do here - the problem is that the conversion
125 * will blow up some entries by four bytes, so it can't be done in place.
126 * This is too bad. Right now the conversion is done entry by entry, the
127 * converted entry is sent via uiomove.
129 * XXX allocate a buffer, convert as many entries as possible, then send
130 * the whole buffer to uiomove
132 * ext2_readdir(struct vnode *a_vp, struct uio *a_uio, struct ucred *a_cred)
135 ext2_readdir(struct vop_readdir_args *ap)
137 struct uio *uio = ap->a_uio;
139 struct ext2_dir_entry_2 *edp, *dp;
144 int DIRBLKSIZ = VTOI(ap->a_vp)->i_e2fs->s_blocksize;
146 off_t startoffset = uio->uio_offset;
148 if ((error = vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY)) != 0)
151 count = uio->uio_resid;
153 * Avoid complications for partial directory entries by adjusting
154 * the i/o to end at a block boundary. Don't give up (like ufs
155 * does) if the initial adjustment gives a negative count, since
156 * many callers don't supply a large enough buffer. The correct
157 * size is a little larger than DIRBLKSIZ to allow for expansion
158 * of directory entries, but some callers just use 512.
160 count -= (uio->uio_offset + count) & (DIRBLKSIZ -1);
163 if (count > MAXBSIZE) /* limit to a reasonable size */
167 kprintf("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 dirbuf = kmalloc(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 for (dp = (struct ext2_dir_entry_2 *)dirbuf;
185 !error && uio->uio_resid > 0 && dp < edp; ) {
187 * "New" ext2fs directory entries differ in 3 ways
188 * from ufs on-disk ones:
189 * - the name is not necessarily NUL-terminated.
190 * - the file type field always exists and always
191 * follows the name length field.
192 * - the file type is encoded in a different way.
194 * "Old" ext2fs directory entries need no special
195 * conversions, since they binary compatible with
196 * "new" entries having a file type of 0 (i.e.,
197 * EXT2_FT_UNKNOWN). Splitting the old name length
198 * field didn't make a mess like it did in ufs,
199 * because ext2fs uses a machine-dependent disk
202 if (dp->rec_len <= 0) {
206 retval = vop_write_dirent(&error, uio, dp->inode,
207 FTTODT(dp->file_type), dp->name_len, dp->name);
212 dp = (struct ext2_dir_entry_2 *)((char *)dp + dp->rec_len);
216 /* we need to correct uio_offset */
217 uio->uio_offset = startoffset + (caddr_t)dp - dirbuf;
219 if (!error && ap->a_ncookies != NULL) {
220 off_t *cookiep, *cookies, *ecookies;
223 if (uio->uio_segflg != UIO_SYSSPACE || uio->uio_iovcnt != 1)
224 panic("ext2fs_readdir: unexpected uio from NFS server");
226 cookies = kmalloc(ncookies * sizeof(off_t),
229 cookies = kmalloc(sizeof(off_t), M_TEMP,
233 for (dp = (struct ext2_dir_entry_2 *)dirbuf,
234 cookiep = cookies, ecookies = cookies + ncookies;
236 dp = (struct ext2_dir_entry_2 *)((caddr_t) dp + dp->rec_len)) {
240 *ap->a_ncookies = ncookies;
241 *ap->a_cookies = cookies;
244 kfree(dirbuf, M_TEMP);
246 *ap->a_eofflag = VTOI(ap->a_vp)->i_size <= uio->uio_offset;
252 * Convert a component of a pathname into a pointer to a locked inode.
253 * This is a very central and rather complicated routine.
254 * If the file system is not maintained in a strict tree hierarchy,
255 * this can result in a deadlock situation (see comments in code below).
257 * The cnp->cn_nameiop argument is LOOKUP, CREATE, RENAME, or DELETE depending
258 * on whether the name is to be looked up, created, renamed, or deleted.
259 * When CREATE, RENAME, or DELETE is specified, information usable in
260 * creating, renaming, or deleting a directory entry may be calculated.
261 * If flag has LOCKPARENT or'ed into it and the target of the pathname
262 * exists, lookup returns both the target and its parent directory locked.
263 * When creating or renaming and LOCKPARENT is specified, the target may
264 * not be ".". When deleting and LOCKPARENT is specified, the target may
265 * be "."., but the caller must check to ensure it does an vrele and vput
266 * instead of two vputs.
268 * Overall outline of ufs_lookup:
270 * search for name in directory, to found or notfound
272 * if creating, return locked directory, leaving info on available slots
275 * if at end of path and deleting, return information to allow delete
276 * if at end of path and rewriting (RENAME and LOCKPARENT), lock target
277 * inode and return info to allow rewrite
278 * if not at end, add name to cache; if at end and neither creating
279 * nor deleting, add name to cache
281 * ext2_lookup(struct vnode *a_dvp, struct vnode **a_vpp,
282 * struct componentname *a_cnp)
285 ext2_lookup(struct vop_old_lookup_args *ap)
287 struct vnode *vdp; /* vnode for directory being searched */
288 struct inode *dp; /* inode for directory being searched */
289 struct buf *bp; /* a buffer of directory entries */
290 struct ext2_dir_entry_2 *ep; /* the current directory entry */
291 int entryoffsetinblock; /* offset of ep in bp's buffer */
292 enum {NONE, COMPACT, FOUND} slotstatus;
293 doff_t slotoffset; /* offset of area with free space */
294 int slotsize; /* size of area at slotoffset */
295 int slotfreespace; /* amount of space free in slot */
296 int slotneeded; /* size of the entry we're seeking */
297 int numdirpasses; /* strategy for directory search */
298 doff_t endsearch; /* offset to end directory search */
299 doff_t prevoff; /* prev entry dp->i_offset */
300 struct vnode *pdp; /* saved dp during symlink work */
301 struct vnode *tdp; /* returned by VFS_VGET */
302 doff_t enduseful; /* pointer past last used dir slot */
303 u_long bmask; /* block offset mask */
304 int lockparent; /* 1 => lockparent flag is set */
305 int wantparent; /* 1 => wantparent or lockparent flag */
307 struct vnode **vpp = ap->a_vpp;
308 struct componentname *cnp = ap->a_cnp;
309 struct ucred *cred = cnp->cn_cred;
310 int flags = cnp->cn_flags;
311 int nameiop = cnp->cn_nameiop;
313 int DIRBLKSIZ = VTOI(ap->a_dvp)->i_e2fs->s_blocksize;
320 lockparent = flags & CNP_LOCKPARENT;
321 wantparent = flags & (CNP_LOCKPARENT|CNP_WANTPARENT);
324 * We now have a segment name to search for, and a directory to search.
328 * Suppress search for slots unless creating
329 * file and at end of pathname, in which case
330 * we watch for a place to put the new file in
331 * case it doesn't already exist.
334 slotfreespace = slotsize = slotneeded = 0;
335 if (nameiop == NAMEI_CREATE || nameiop == NAMEI_RENAME) {
337 slotneeded = EXT2_DIR_REC_LEN(cnp->cn_namelen);
339 slotneeded = (sizeof(struct direct) - MAXNAMLEN +
340 cnp->cn_namelen + 3) &~ 3; */
344 * If there is cached information on a previous search of
345 * this directory, pick up where we last left off.
346 * We cache only lookups as these are the most common
347 * and have the greatest payoff. Caching CREATE has little
348 * benefit as it usually must search the entire directory
349 * to determine that the entry does not exist. Caching the
350 * location of the last DELETE or RENAME has not reduced
351 * profiling time and hence has been removed in the interest
354 bmask = VFSTOEXT2(vdp->v_mount)->um_mountp->mnt_stat.f_iosize - 1;
355 if (nameiop != NAMEI_LOOKUP || dp->i_diroff == 0 ||
356 dp->i_diroff > dp->i_size) {
357 entryoffsetinblock = 0;
361 dp->i_offset = dp->i_diroff;
362 if ((entryoffsetinblock = dp->i_offset & bmask) &&
363 (error = EXT2_BLKATOFF(vdp, (off_t)dp->i_offset, NULL, &bp)))
367 prevoff = dp->i_offset;
368 endsearch = roundup(dp->i_size, DIRBLKSIZ);
372 while (dp->i_offset < endsearch) {
374 * If necessary, get the next directory block.
376 if ((dp->i_offset & bmask) == 0) {
380 EXT2_BLKATOFF(vdp, (off_t)dp->i_offset, NULL, &bp)) != 0)
382 entryoffsetinblock = 0;
385 * If still looking for a slot, and at a DIRBLKSIZE
386 * boundary, have to start looking for free space again.
388 if (slotstatus == NONE &&
389 (entryoffsetinblock & (DIRBLKSIZ - 1)) == 0) {
394 * Get pointer to next entry.
395 * Full validation checks are slow, so we only check
396 * enough to insure forward progress through the
397 * directory. Complete checks can be run by patching
398 * "dirchk" to be true.
400 ep = (struct ext2_dir_entry_2 *)
401 ((char *)bp->b_data + entryoffsetinblock);
402 if (ep->rec_len == 0 ||
403 (dirchk && ext2_dirbadentry(vdp, ep, entryoffsetinblock))) {
405 ext2_dirbad(dp, dp->i_offset, "mangled entry");
406 i = DIRBLKSIZ - (entryoffsetinblock & (DIRBLKSIZ - 1));
408 entryoffsetinblock += i;
413 * If an appropriate sized slot has not yet been found,
414 * check to see if one is available. Also accumulate space
415 * in the current block so that we can determine if
416 * compaction is viable.
418 if (slotstatus != FOUND) {
419 int size = ep->rec_len;
422 size -= EXT2_DIR_REC_LEN(ep->name_len);
424 if (size >= slotneeded) {
426 slotoffset = dp->i_offset;
427 slotsize = ep->rec_len;
428 } else if (slotstatus == NONE) {
429 slotfreespace += size;
430 if (slotoffset == -1)
431 slotoffset = dp->i_offset;
432 if (slotfreespace >= slotneeded) {
433 slotstatus = COMPACT;
434 slotsize = dp->i_offset +
435 ep->rec_len - slotoffset;
442 * Check for a name match.
445 namlen = ep->name_len;
446 if (namlen == cnp->cn_namelen &&
447 !bcmp(cnp->cn_nameptr, ep->name,
450 * Save directory entry's inode number and
451 * reclen in ndp->ni_ufs area, and release
454 dp->i_ino = ep->inode;
455 dp->i_reclen = ep->rec_len;
459 prevoff = dp->i_offset;
460 dp->i_offset += ep->rec_len;
461 entryoffsetinblock += ep->rec_len;
463 enduseful = dp->i_offset;
467 * If we started in the middle of the directory and failed
468 * to find our target, we must check the beginning as well.
470 if (numdirpasses == 2) {
473 endsearch = dp->i_diroff;
479 * If creating, and at end of pathname and current
480 * directory has not been removed, then can consider
481 * allowing file to be created.
483 if ((nameiop == NAMEI_CREATE || nameiop == NAMEI_RENAME) &&
486 * Access for write is interpreted as allowing
487 * creation of files in the directory.
489 if ((error = VOP_EACCESS(vdp, VWRITE, cred)) != 0)
492 * Return an indication of where the new directory
493 * entry should be put. If we didn't find a slot,
494 * then set dp->i_count to 0 indicating
495 * that the new slot belongs at the end of the
496 * directory. If we found a slot, then the new entry
497 * can be put in the range from dp->i_offset to
498 * dp->i_offset + dp->i_count.
500 if (slotstatus == NONE) {
501 dp->i_offset = roundup(dp->i_size, DIRBLKSIZ);
503 enduseful = dp->i_offset;
505 dp->i_offset = slotoffset;
506 dp->i_count = slotsize;
507 if (enduseful < slotoffset + slotsize)
508 enduseful = slotoffset + slotsize;
510 dp->i_endoff = roundup(enduseful, DIRBLKSIZ);
511 dp->i_flag |= IN_CHANGE | IN_UPDATE;
513 * We return with the directory locked, so that
514 * the parameters we set up above will still be
515 * valid if we actually decide to do a direnter().
516 * We return ni_vp == NULL to indicate that the entry
517 * does not currently exist; we leave a pointer to
518 * the (locked) directory inode in ndp->ni_dvp.
519 * The pathname buffer is saved so that the name
520 * can be obtained later.
522 * NB - if the directory is unlocked, then this
523 * information cannot be used.
527 return (EJUSTRETURN);
533 * Check that directory length properly reflects presence
536 if (entryoffsetinblock + EXT2_DIR_REC_LEN(ep->name_len)
538 ext2_dirbad(dp, dp->i_offset, "i_size too small");
539 dp->i_size = entryoffsetinblock+EXT2_DIR_REC_LEN(ep->name_len);
540 dp->i_flag |= IN_CHANGE | IN_UPDATE;
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.
549 if (nameiop == NAMEI_LOOKUP)
550 dp->i_diroff = dp->i_offset &~ (DIRBLKSIZ - 1);
553 * If deleting, and at end of pathname, return
554 * parameters which can be used to remove file.
555 * If the wantparent flag isn't set, we return only
556 * the directory (in ndp->ni_dvp), otherwise we go
557 * on and lock the inode, being careful with ".".
559 if (nameiop == NAMEI_DELETE) {
561 * Write access to directory required to delete files.
563 if ((error = VOP_EACCESS(vdp, VWRITE, cred)) != 0)
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().
571 if ((dp->i_offset & (DIRBLKSIZ - 1)) == 0)
574 dp->i_count = dp->i_offset - prevoff;
575 if (dp->i_number == dp->i_ino) {
580 if ((error = VFS_VGET(vdp->v_mount, NULL, dp->i_ino, &tdp)) != 0)
583 * If directory is "sticky", then user must own
584 * the directory, or the file in it, else she
585 * may not delete it (unless she's root). This
586 * implements append-only directories.
588 if ((dp->i_mode & ISVTX) &&
590 cred->cr_uid != dp->i_uid &&
591 VTOI(tdp)->i_uid != cred->cr_uid) {
602 * If rewriting (RENAME), return the inode and the
603 * information required to rewrite the present directory
604 * Must get inode of directory entry to verify it's a
605 * regular file, or empty directory.
607 if (nameiop == NAMEI_RENAME && wantparent) {
608 if ((error = VOP_EACCESS(vdp, VWRITE, cred)) != 0)
611 * Careful about locking second inode.
612 * This can only occur if the target is ".".
614 if (dp->i_number == dp->i_ino)
616 if ((error = VFS_VGET(vdp->v_mount, NULL, dp->i_ino, &tdp)) != 0)
625 * Step through the translation in the name. We do not `vput' the
626 * directory because we may need it again if a symbolic link
627 * is relative to the current directory. Instead we save it
628 * unlocked as "pdp". We must get the target inode before unlocking
629 * the directory to insure that the inode will not be removed
630 * before we get it. We prevent deadlock by always fetching
631 * inodes from the root, moving down the directory tree. Thus
632 * when following backward pointers ".." we must unlock the
633 * parent directory before getting the requested directory.
634 * There is a potential race condition here if both the current
635 * and parent directories are removed before the VFS_VGET for the
636 * inode associated with ".." returns. We hope that this occurs
637 * infrequently since we cannot avoid this race condition without
638 * implementing a sophisticated deadlock detection algorithm.
639 * Note also that this simple deadlock detection scheme will not
640 * work if the file system has any hard links other than ".."
641 * that point backwards in the directory structure.
644 if (flags & CNP_ISDOTDOT) {
645 vn_unlock(pdp); /* race to get the inode */
646 if ((error = VFS_VGET(vdp->v_mount, NULL, dp->i_ino, &tdp)) != 0) {
647 vn_lock(pdp, LK_EXCLUSIVE | LK_RETRY);
650 if (lockparent && (error = vn_lock(pdp, LK_EXCLUSIVE))) {
655 } else if (dp->i_number == dp->i_ino) {
656 vref(vdp); /* we want ourself, ie "." */
659 if ((error = VFS_VGET(vdp->v_mount, NULL, dp->i_ino, &tdp)) != 0)
669 ext2_dirbad(struct inode *ip, doff_t offset, char *how)
673 mp = ITOV(ip)->v_mount;
674 kprintf("%s: bad dir ino %lu at offset %ld: %s\n",
675 mp->mnt_stat.f_mntfromname, (u_long)ip->i_number,
677 if ((mp->mnt_flag & MNT_RDONLY) == 0)
678 panic("ufs_dirbad: bad dir");
682 * Do consistency checking on a directory entry:
683 * record length must be multiple of 4
684 * entry must fit in rest of its DIRBLKSIZ block
685 * record must be large enough to contain entry
686 * name is not longer than MAXNAMLEN
687 * name must be as long as advertised, and null terminated
690 * changed so that it confirms to ext2_check_dir_entry
693 ext2_dirbadentry(struct vnode *dp, struct ext2_dir_entry_2 *de,
694 int entryoffsetinblock)
696 int DIRBLKSIZ = VTOI(dp)->i_e2fs->s_blocksize;
698 char * error_msg = NULL;
700 if (de->rec_len < EXT2_DIR_REC_LEN(1))
701 error_msg = "rec_len is smaller than minimal";
702 else if (de->rec_len % 4 != 0)
703 error_msg = "rec_len % 4 != 0";
704 else if (de->rec_len < EXT2_DIR_REC_LEN(de->name_len))
705 error_msg = "reclen is too small for name_len";
706 else if (entryoffsetinblock + de->rec_len > DIRBLKSIZ)
707 error_msg = "directory entry across blocks";
709 if (de->inode > dir->i_sb->u.ext2_sb.s_es->s_inodes_count)
710 error_msg = "inode out of bounds";
713 if (error_msg != NULL) {
714 kprintf("bad directory entry: %s\n", error_msg);
715 kprintf("offset=%d, inode=%lu, rec_len=%u, name_len=%u\n",
716 entryoffsetinblock, (unsigned long)de->inode,
717 de->rec_len, de->name_len);
719 return error_msg == NULL ? 0 : 1;
723 * Write a directory entry after a call to namei, using the parameters
724 * that it left in the directory inode. The argument ip is the inode which
725 * the new directory entry will refer to. Dvp is a pointer to the directory
726 * to be written, which was left locked by namei. Remaining parameters
727 * (dp->i_offset, dp->i_count) indicate how the space for the new
728 * entry is to be obtained.
731 ext2_direnter(struct inode *ip, struct vnode *dvp, struct componentname *cnp)
733 struct ext2_dir_entry_2 *ep, *nep;
736 struct ext2_dir_entry_2 newdir;
740 int error, loc, newentrysize, spacefree;
742 int DIRBLKSIZ = ip->i_e2fs->s_blocksize;
746 newdir.inode = ip->i_number;
747 newdir.name_len = cnp->cn_namelen;
748 if (EXT2_HAS_INCOMPAT_FEATURE(ip->i_e2fs->s_es,
749 EXT2_FEATURE_INCOMPAT_FILETYPE))
750 newdir.file_type = DTTOFT(IFTODT(ip->i_mode));
752 newdir.file_type = EXT2_FT_UNKNOWN;
753 bcopy(cnp->cn_nameptr, newdir.name, (unsigned)cnp->cn_namelen + 1);
754 newentrysize = EXT2_DIR_REC_LEN(newdir.name_len);
755 if (dp->i_count == 0) {
757 * If dp->i_count is 0, then namei could find no
758 * space in the directory. Here, dp->i_offset will
759 * be on a directory block boundary and we will write the
760 * new entry into a fresh block.
762 if (dp->i_offset & (DIRBLKSIZ - 1))
763 panic("ext2_direnter: newblk");
764 auio.uio_offset = dp->i_offset;
765 newdir.rec_len = DIRBLKSIZ;
766 auio.uio_resid = newentrysize;
767 aiov.iov_len = newentrysize;
768 aiov.iov_base = (caddr_t)&newdir;
769 auio.uio_iov = &aiov;
771 auio.uio_rw = UIO_WRITE;
772 auio.uio_segflg = UIO_SYSSPACE;
774 error = VOP_WRITE(dvp, &auio, IO_SYNC, cnp->cn_cred);
776 VFSTOEXT2(dvp->v_mount)->um_mountp->mnt_stat.f_bsize)
777 /* XXX should grow with balloc() */
778 panic("ext2_direnter: frag size");
780 dp->i_size = roundup(dp->i_size, DIRBLKSIZ);
781 dp->i_flag |= IN_CHANGE;
787 * If dp->i_count is non-zero, then namei found space
788 * for the new entry in the range dp->i_offset to
789 * dp->i_offset + dp->i_count in the directory.
790 * To use this space, we may have to compact the entries located
791 * there, by copying them together towards the beginning of the
792 * block, leaving the free space in one usable chunk at the end.
796 * Increase size of directory if entry eats into new space.
797 * This should never push the size past a new multiple of
800 * N.B. - THIS IS AN ARTIFACT OF 4.2 AND SHOULD NEVER HAPPEN.
802 if (dp->i_offset + dp->i_count > dp->i_size)
803 dp->i_size = dp->i_offset + dp->i_count;
805 * Get the block containing the space for the new directory entry.
807 if ((error = EXT2_BLKATOFF(dvp, (off_t)dp->i_offset, &dirbuf, &bp)) != 0)
810 * Find space for the new entry. In the simple case, the entry at
811 * offset base will have the space. If it does not, then namei
812 * arranged that compacting the region dp->i_offset to
813 * dp->i_offset + dp->i_count would yield the
816 ep = (struct ext2_dir_entry_2 *)dirbuf;
817 dsize = EXT2_DIR_REC_LEN(ep->name_len);
818 spacefree = ep->rec_len - dsize;
819 for (loc = ep->rec_len; loc < dp->i_count; ) {
820 nep = (struct ext2_dir_entry_2 *)(dirbuf + loc);
822 /* trim the existing slot */
824 ep = (struct ext2_dir_entry_2 *)((char *)ep + dsize);
826 /* overwrite; nothing there; header is ours */
829 dsize = EXT2_DIR_REC_LEN(nep->name_len);
830 spacefree += nep->rec_len - dsize;
832 bcopy((caddr_t)nep, (caddr_t)ep, dsize);
835 * Update the pointer fields in the previous entry (if any),
836 * copy in the new entry, and write out the block.
838 if (ep->inode == 0) {
839 if (spacefree + dsize < newentrysize)
840 panic("ext2_direnter: compact1");
841 newdir.rec_len = spacefree + dsize;
843 if (spacefree < newentrysize)
844 panic("ext2_direnter: compact2");
845 newdir.rec_len = spacefree;
847 ep = (struct ext2_dir_entry_2 *)((char *)ep + dsize);
849 bcopy((caddr_t)&newdir, (caddr_t)ep, (u_int)newentrysize);
851 dp->i_flag |= IN_CHANGE | IN_UPDATE;
852 if (!error && dp->i_endoff && dp->i_endoff < dp->i_size)
853 error = EXT2_TRUNCATE(dvp, (off_t)dp->i_endoff, IO_SYNC,
859 * Remove a directory entry after a call to namei, using
860 * the parameters which it left in the directory inode. The entry
861 * dp->i_offset contains the offset into the directory of the
862 * entry to be eliminated. The dp->i_count field contains the
863 * size of the previous record in the directory. If this
864 * is 0, the first entry is being deleted, so we need only
865 * zero the inode number to mark the entry as free. If the
866 * entry is not the first in the directory, we must reclaim
867 * the space of the now empty record by adding the record size
868 * to the size of the previous entry.
871 ext2_dirremove(struct vnode *dvp, struct componentname *cnp)
874 struct ext2_dir_entry_2 *ep;
879 if (dp->i_count == 0) {
881 * First entry in block: set d_ino to zero.
884 EXT2_BLKATOFF(dvp, (off_t)dp->i_offset, (char **)&ep, &bp)) != 0)
888 dp->i_flag |= IN_CHANGE | IN_UPDATE;
892 * Collapse new free space into previous entry.
894 if ((error = EXT2_BLKATOFF(dvp, (off_t)(dp->i_offset - dp->i_count),
895 (char **)&ep, &bp)) != 0)
897 ep->rec_len += dp->i_reclen;
899 dp->i_flag |= IN_CHANGE | IN_UPDATE;
904 * Rewrite an existing directory entry to point at the inode
905 * supplied. The parameters describing the directory entry are
906 * set up by a call to namei.
909 ext2_dirrewrite(struct inode *dp, struct inode *ip, struct componentname *cnp)
912 struct ext2_dir_entry_2 *ep;
913 struct vnode *vdp = ITOV(dp);
916 if ((error = EXT2_BLKATOFF(vdp, (off_t)dp->i_offset, (char **)&ep, &bp)) != 0)
918 ep->inode = ip->i_number;
919 if (EXT2_HAS_INCOMPAT_FEATURE(ip->i_e2fs->s_es,
920 EXT2_FEATURE_INCOMPAT_FILETYPE))
921 ep->file_type = DTTOFT(IFTODT(ip->i_mode));
923 ep->file_type = EXT2_FT_UNKNOWN;
925 dp->i_flag |= IN_CHANGE | IN_UPDATE;
930 * Check if a directory is empty or not.
931 * Inode supplied must be locked.
933 * Using a struct dirtemplate here is not precisely
934 * what we want, but better than using a struct direct.
936 * NB: does not handle corrupted directories.
939 ext2_dirempty(struct inode *ip, ino_t parentino, struct ucred *cred)
942 struct dirtemplate dbuf;
943 struct ext2_dir_entry_2 *dp = (struct ext2_dir_entry_2 *)&dbuf;
944 int error, count, namlen;
946 #define MINDIRSIZ (sizeof (struct dirtemplate) / 2)
948 for (off = 0; off < ip->i_size; off += dp->rec_len) {
949 error = vn_rdwr(UIO_READ, ITOV(ip), (caddr_t)dp, MINDIRSIZ, off,
950 UIO_SYSSPACE, IO_NODELOCKED, cred, &count);
952 * Since we read MINDIRSIZ, residual must
953 * be 0 unless we're at end of file.
955 if (error || count != 0)
957 /* avoid infinite loops */
958 if (dp->rec_len == 0)
960 /* skip empty entries */
963 /* accept only "." and ".." */
964 namlen = dp->name_len;
967 if (dp->name[0] != '.')
970 * At this point namlen must be 1 or 2.
971 * 1 implies ".", 2 implies ".." if second
976 if (dp->name[1] == '.' && dp->inode == parentino)
984 * Check if source directory is in the path of the target directory.
985 * Target is supplied locked, source is unlocked.
986 * The target is always vput before returning.
989 ext2_checkpath(struct inode *source, struct inode *target, struct ucred *cred)
992 int error, rootino, namlen;
993 struct dirtemplate dirbuf;
996 if (target->i_number == source->i_number) {
1002 if (target->i_number == rootino)
1006 if (vp->v_type != VDIR) {
1010 error = vn_rdwr(UIO_READ, vp, (caddr_t)&dirbuf,
1011 sizeof (struct dirtemplate), (off_t)0,
1012 UIO_SYSSPACE, IO_NODELOCKED, cred, NULL);
1015 namlen = dirbuf.dotdot_type; /* like ufs little-endian */
1017 dirbuf.dotdot_name[0] != '.' ||
1018 dirbuf.dotdot_name[1] != '.') {
1022 if (dirbuf.dotdot_ino == source->i_number) {
1026 if (dirbuf.dotdot_ino == rootino)
1029 if ((error = VFS_VGET(vp->v_mount, NULL, dirbuf.dotdot_ino, &vp)) != 0) {
1036 if (error == ENOTDIR)
1037 kprintf("checkpath: .. not a directory\n");