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 1.27 2007/11/20 21:03:50 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>
62 #include "ext2mount.h"
63 #include "ext2_extern.h"
65 #include "ext2_fs_sb.h"
68 DIRBLKSIZE in ffs is DEV_BSIZE (in most cases 512)
69 while it is the native blocksize in ext2fs - thus, a #define
70 is no longer appropriate
76 static u_char ext2_ft_to_dt[] = {
77 DT_UNKNOWN, /* EXT2_FT_UNKNOWN */
78 DT_REG, /* EXT2_FT_REG_FILE */
79 DT_DIR, /* EXT2_FT_DIR */
80 DT_CHR, /* EXT2_FT_CHRDEV */
81 DT_BLK, /* EXT2_FT_BLKDEV */
82 DT_FIFO, /* EXT2_FT_FIFO */
83 DT_SOCK, /* EXT2_FT_SOCK */
84 DT_LNK, /* EXT2_FT_SYMLINK */
87 ((ft) > sizeof(ext2_ft_to_dt) / sizeof(ext2_ft_to_dt[0]) ? \
88 DT_UNKNOWN : ext2_ft_to_dt[(ft)])
90 static u_char dt_to_ext2_ft[] = {
91 EXT2_FT_UNKNOWN, /* DT_UNKNOWN */
92 EXT2_FT_FIFO, /* DT_FIFO */
93 EXT2_FT_CHRDEV, /* DT_CHR */
94 EXT2_FT_UNKNOWN, /* unused */
95 EXT2_FT_DIR, /* DT_DIR */
96 EXT2_FT_UNKNOWN, /* unused */
97 EXT2_FT_BLKDEV, /* DT_BLK */
98 EXT2_FT_UNKNOWN, /* unused */
99 EXT2_FT_REG_FILE, /* DT_REG */
100 EXT2_FT_UNKNOWN, /* unused */
101 EXT2_FT_SYMLINK, /* DT_LNK */
102 EXT2_FT_UNKNOWN, /* unused */
103 EXT2_FT_SOCK, /* DT_SOCK */
104 EXT2_FT_UNKNOWN, /* unused */
105 EXT2_FT_UNKNOWN, /* DT_WHT */
108 ((dt) > sizeof(dt_to_ext2_ft) / sizeof(dt_to_ext2_ft[0]) ? \
109 EXT2_FT_UNKNOWN : dt_to_ext2_ft[(dt)])
111 static int ext2_dirbadentry (struct vnode *dp,
112 struct ext2_dir_entry_2 *de,
113 int entryoffsetinblock);
116 * Vnode op for reading directories.
118 * The routine below assumes that the on-disk format of a directory
119 * is the same as that defined by <sys/dirent.h>. If the on-disk
120 * format changes, then it will be necessary to do a conversion
121 * from the on-disk format that read returns to the format defined
125 * this is exactly what we do here - the problem is that the conversion
126 * will blow up some entries by four bytes, so it can't be done in place.
127 * This is too bad. Right now the conversion is done entry by entry, the
128 * converted entry is sent via uiomove.
130 * XXX allocate a buffer, convert as many entries as possible, then send
131 * the whole buffer to uiomove
133 * ext2_readdir(struct vnode *a_vp, struct uio *a_uio, struct ucred *a_cred)
136 ext2_readdir(struct vop_readdir_args *ap)
138 struct uio *uio = ap->a_uio;
140 struct ext2_dir_entry_2 *edp, *dp;
145 int DIRBLKSIZ = VTOI(ap->a_vp)->i_e2fs->s_blocksize;
147 off_t startoffset = uio->uio_offset;
149 if ((error = vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY)) != 0)
152 count = uio->uio_resid;
154 * Avoid complications for partial directory entries by adjusting
155 * the i/o to end at a block boundary. Don't give up (like ufs
156 * does) if the initial adjustment gives a negative count, since
157 * many callers don't supply a large enough buffer. The correct
158 * size is a little larger than DIRBLKSIZ to allow for expansion
159 * of directory entries, but some callers just use 512.
161 count -= (uio->uio_offset + count) & (DIRBLKSIZ -1);
164 if (count > MAXBSIZE) /* limit to a reasonable size */
168 kprintf("ext2_readdir: uio_offset = %lld, uio_resid = %d, count = %d\n",
169 uio->uio_offset, uio->uio_resid, count);
173 auio.uio_iov = &aiov;
175 auio.uio_resid = count;
176 auio.uio_segflg = UIO_SYSSPACE;
177 aiov.iov_len = count;
178 MALLOC(dirbuf, caddr_t, count, M_TEMP, M_WAITOK);
179 aiov.iov_base = dirbuf;
180 error = VOP_READ(ap->a_vp, &auio, 0, ap->a_cred);
182 readcnt = count - auio.uio_resid;
183 edp = (struct ext2_dir_entry_2 *)&dirbuf[readcnt];
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 if (dp->rec_len <= 0) {
207 retval = vop_write_dirent(&error, uio, dp->inode,
208 FTTODT(dp->file_type), dp->name_len, dp->name);
213 dp = (struct ext2_dir_entry_2 *)((char *)dp + dp->rec_len);
217 /* we need to correct uio_offset */
218 uio->uio_offset = startoffset + (caddr_t)dp - dirbuf;
220 if (!error && ap->a_ncookies != NULL) {
221 off_t *cookiep, *cookies, *ecookies;
224 if (uio->uio_segflg != UIO_SYSSPACE || uio->uio_iovcnt != 1)
225 panic("ext2fs_readdir: unexpected uio from NFS server");
227 MALLOC(cookies, off_t *,
228 ncookies * sizeof(off_t),
231 MALLOC(cookies, off_t *,
232 sizeof(off_t), M_TEMP, M_WAITOK);
235 for (dp = (struct ext2_dir_entry_2 *)dirbuf,
236 cookiep = cookies, ecookies = cookies + ncookies;
238 dp = (struct ext2_dir_entry_2 *)((caddr_t) dp + dp->rec_len)) {
242 *ap->a_ncookies = ncookies;
243 *ap->a_cookies = cookies;
246 FREE(dirbuf, M_TEMP);
248 *ap->a_eofflag = VTOI(ap->a_vp)->i_size <= uio->uio_offset;
254 * Convert a component of a pathname into a pointer to a locked inode.
255 * This is a very central and rather complicated routine.
256 * If the file system is not maintained in a strict tree hierarchy,
257 * this can result in a deadlock situation (see comments in code below).
259 * The cnp->cn_nameiop argument is LOOKUP, CREATE, RENAME, or DELETE depending
260 * on whether the name is to be looked up, created, renamed, or deleted.
261 * When CREATE, RENAME, or DELETE is specified, information usable in
262 * creating, renaming, or deleting a directory entry may be calculated.
263 * If flag has LOCKPARENT or'ed into it and the target of the pathname
264 * exists, lookup returns both the target and its parent directory locked.
265 * When creating or renaming and LOCKPARENT is specified, the target may
266 * not be ".". When deleting and LOCKPARENT is specified, the target may
267 * be "."., but the caller must check to ensure it does an vrele and vput
268 * instead of two vputs.
270 * Overall outline of ufs_lookup:
272 * search for name in directory, to found or notfound
274 * if creating, return locked directory, leaving info on available slots
277 * if at end of path and deleting, return information to allow delete
278 * if at end of path and rewriting (RENAME and LOCKPARENT), lock target
279 * inode and return info to allow rewrite
280 * if not at end, add name to cache; if at end and neither creating
281 * nor deleting, add name to cache
283 * ext2_lookup(struct vnode *a_dvp, struct vnode **a_vpp,
284 * struct componentname *a_cnp)
287 ext2_lookup(struct vop_old_lookup_args *ap)
289 struct vnode *vdp; /* vnode for directory being searched */
290 struct inode *dp; /* inode for directory being searched */
291 struct buf *bp; /* a buffer of directory entries */
292 struct ext2_dir_entry_2 *ep; /* the current directory entry */
293 int entryoffsetinblock; /* offset of ep in bp's buffer */
294 enum {NONE, COMPACT, FOUND} slotstatus;
295 doff_t slotoffset; /* offset of area with free space */
296 int slotsize; /* size of area at slotoffset */
297 int slotfreespace; /* amount of space free in slot */
298 int slotneeded; /* size of the entry we're seeking */
299 int numdirpasses; /* strategy for directory search */
300 doff_t endsearch; /* offset to end directory search */
301 doff_t prevoff; /* prev entry dp->i_offset */
302 struct vnode *pdp; /* saved dp during symlink work */
303 struct vnode *tdp; /* returned by VFS_VGET */
304 doff_t enduseful; /* pointer past last used dir slot */
305 u_long bmask; /* block offset mask */
306 int lockparent; /* 1 => lockparent flag is set */
307 int wantparent; /* 1 => wantparent or lockparent flag */
309 struct vnode **vpp = ap->a_vpp;
310 struct componentname *cnp = ap->a_cnp;
311 struct ucred *cred = cnp->cn_cred;
312 int flags = cnp->cn_flags;
313 int nameiop = cnp->cn_nameiop;
315 int DIRBLKSIZ = VTOI(ap->a_dvp)->i_e2fs->s_blocksize;
322 lockparent = flags & CNP_LOCKPARENT;
323 wantparent = flags & (CNP_LOCKPARENT|CNP_WANTPARENT);
326 * We now have a segment name to search for, and a directory to search.
330 * Suppress search for slots unless creating
331 * file and at end of pathname, in which case
332 * we watch for a place to put the new file in
333 * case it doesn't already exist.
336 slotfreespace = slotsize = slotneeded = 0;
337 if (nameiop == NAMEI_CREATE || nameiop == NAMEI_RENAME) {
339 slotneeded = EXT2_DIR_REC_LEN(cnp->cn_namelen);
341 slotneeded = (sizeof(struct direct) - MAXNAMLEN +
342 cnp->cn_namelen + 3) &~ 3; */
346 * If there is cached information on a previous search of
347 * this directory, pick up where we last left off.
348 * We cache only lookups as these are the most common
349 * and have the greatest payoff. Caching CREATE has little
350 * benefit as it usually must search the entire directory
351 * to determine that the entry does not exist. Caching the
352 * location of the last DELETE or RENAME has not reduced
353 * profiling time and hence has been removed in the interest
356 bmask = VFSTOEXT2(vdp->v_mount)->um_mountp->mnt_stat.f_iosize - 1;
357 if (nameiop != NAMEI_LOOKUP || dp->i_diroff == 0 ||
358 dp->i_diroff > dp->i_size) {
359 entryoffsetinblock = 0;
363 dp->i_offset = dp->i_diroff;
364 if ((entryoffsetinblock = dp->i_offset & bmask) &&
365 (error = EXT2_BLKATOFF(vdp, (off_t)dp->i_offset, NULL, &bp)))
369 prevoff = dp->i_offset;
370 endsearch = roundup(dp->i_size, DIRBLKSIZ);
374 while (dp->i_offset < endsearch) {
376 * If necessary, get the next directory block.
378 if ((dp->i_offset & bmask) == 0) {
382 EXT2_BLKATOFF(vdp, (off_t)dp->i_offset, NULL, &bp)) != 0)
384 entryoffsetinblock = 0;
387 * If still looking for a slot, and at a DIRBLKSIZE
388 * boundary, have to start looking for free space again.
390 if (slotstatus == NONE &&
391 (entryoffsetinblock & (DIRBLKSIZ - 1)) == 0) {
396 * Get pointer to next entry.
397 * Full validation checks are slow, so we only check
398 * enough to insure forward progress through the
399 * directory. Complete checks can be run by patching
400 * "dirchk" to be true.
402 ep = (struct ext2_dir_entry_2 *)
403 ((char *)bp->b_data + entryoffsetinblock);
404 if (ep->rec_len == 0 ||
405 (dirchk && ext2_dirbadentry(vdp, ep, entryoffsetinblock))) {
407 ext2_dirbad(dp, dp->i_offset, "mangled entry");
408 i = DIRBLKSIZ - (entryoffsetinblock & (DIRBLKSIZ - 1));
410 entryoffsetinblock += i;
415 * If an appropriate sized slot has not yet been found,
416 * check to see if one is available. Also accumulate space
417 * in the current block so that we can determine if
418 * compaction is viable.
420 if (slotstatus != FOUND) {
421 int size = ep->rec_len;
424 size -= EXT2_DIR_REC_LEN(ep->name_len);
426 if (size >= slotneeded) {
428 slotoffset = dp->i_offset;
429 slotsize = ep->rec_len;
430 } else if (slotstatus == NONE) {
431 slotfreespace += size;
432 if (slotoffset == -1)
433 slotoffset = dp->i_offset;
434 if (slotfreespace >= slotneeded) {
435 slotstatus = COMPACT;
436 slotsize = dp->i_offset +
437 ep->rec_len - slotoffset;
444 * Check for a name match.
447 namlen = ep->name_len;
448 if (namlen == cnp->cn_namelen &&
449 !bcmp(cnp->cn_nameptr, ep->name,
452 * Save directory entry's inode number and
453 * reclen in ndp->ni_ufs area, and release
456 dp->i_ino = ep->inode;
457 dp->i_reclen = ep->rec_len;
461 prevoff = dp->i_offset;
462 dp->i_offset += ep->rec_len;
463 entryoffsetinblock += ep->rec_len;
465 enduseful = dp->i_offset;
469 * If we started in the middle of the directory and failed
470 * to find our target, we must check the beginning as well.
472 if (numdirpasses == 2) {
475 endsearch = dp->i_diroff;
481 * If creating, and at end of pathname and current
482 * directory has not been removed, then can consider
483 * allowing file to be created.
485 if ((nameiop == NAMEI_CREATE || nameiop == NAMEI_RENAME) &&
488 * Access for write is interpreted as allowing
489 * creation of files in the directory.
491 if ((error = VOP_EACCESS(vdp, VWRITE, cred)) != 0)
494 * Return an indication of where the new directory
495 * entry should be put. If we didn't find a slot,
496 * then set dp->i_count to 0 indicating
497 * that the new slot belongs at the end of the
498 * directory. If we found a slot, then the new entry
499 * can be put in the range from dp->i_offset to
500 * dp->i_offset + dp->i_count.
502 if (slotstatus == NONE) {
503 dp->i_offset = roundup(dp->i_size, DIRBLKSIZ);
505 enduseful = dp->i_offset;
507 dp->i_offset = slotoffset;
508 dp->i_count = slotsize;
509 if (enduseful < slotoffset + slotsize)
510 enduseful = slotoffset + slotsize;
512 dp->i_endoff = roundup(enduseful, DIRBLKSIZ);
513 dp->i_flag |= IN_CHANGE | IN_UPDATE;
515 * We return with the directory locked, so that
516 * the parameters we set up above will still be
517 * valid if we actually decide to do a direnter().
518 * We return ni_vp == NULL to indicate that the entry
519 * does not currently exist; we leave a pointer to
520 * the (locked) directory inode in ndp->ni_dvp.
521 * The pathname buffer is saved so that the name
522 * can be obtained later.
524 * NB - if the directory is unlocked, then this
525 * information cannot be used.
529 return (EJUSTRETURN);
535 * Check that directory length properly reflects presence
538 if (entryoffsetinblock + EXT2_DIR_REC_LEN(ep->name_len)
540 ext2_dirbad(dp, dp->i_offset, "i_size too small");
541 dp->i_size = entryoffsetinblock+EXT2_DIR_REC_LEN(ep->name_len);
542 dp->i_flag |= IN_CHANGE | IN_UPDATE;
547 * Found component in pathname.
548 * If the final component of path name, save information
549 * in the cache as to where the entry was found.
551 if (nameiop == NAMEI_LOOKUP)
552 dp->i_diroff = dp->i_offset &~ (DIRBLKSIZ - 1);
555 * If deleting, and at end of pathname, return
556 * parameters which can be used to remove file.
557 * If the wantparent flag isn't set, we return only
558 * the directory (in ndp->ni_dvp), otherwise we go
559 * on and lock the inode, being careful with ".".
561 if (nameiop == NAMEI_DELETE) {
563 * Write access to directory required to delete files.
565 if ((error = VOP_EACCESS(vdp, VWRITE, cred)) != 0)
568 * Return pointer to current entry in dp->i_offset,
569 * and distance past previous entry (if there
570 * is a previous entry in this block) in dp->i_count.
571 * Save directory inode pointer in ndp->ni_dvp for dirremove().
573 if ((dp->i_offset & (DIRBLKSIZ - 1)) == 0)
576 dp->i_count = dp->i_offset - prevoff;
577 if (dp->i_number == dp->i_ino) {
582 if ((error = VFS_VGET(vdp->v_mount, NULL, dp->i_ino, &tdp)) != 0)
585 * If directory is "sticky", then user must own
586 * the directory, or the file in it, else she
587 * may not delete it (unless she's root). This
588 * implements append-only directories.
590 if ((dp->i_mode & ISVTX) &&
592 cred->cr_uid != dp->i_uid &&
593 VTOI(tdp)->i_uid != cred->cr_uid) {
604 * If rewriting (RENAME), return the inode and the
605 * information required to rewrite the present directory
606 * Must get inode of directory entry to verify it's a
607 * regular file, or empty directory.
609 if (nameiop == NAMEI_RENAME && wantparent) {
610 if ((error = VOP_EACCESS(vdp, VWRITE, cred)) != 0)
613 * Careful about locking second inode.
614 * This can only occur if the target is ".".
616 if (dp->i_number == dp->i_ino)
618 if ((error = VFS_VGET(vdp->v_mount, NULL, dp->i_ino, &tdp)) != 0)
627 * Step through the translation in the name. We do not `vput' the
628 * directory because we may need it again if a symbolic link
629 * is relative to the current directory. Instead we save it
630 * unlocked as "pdp". We must get the target inode before unlocking
631 * the directory to insure that the inode will not be removed
632 * before we get it. We prevent deadlock by always fetching
633 * inodes from the root, moving down the directory tree. Thus
634 * when following backward pointers ".." we must unlock the
635 * parent directory before getting the requested directory.
636 * There is a potential race condition here if both the current
637 * and parent directories are removed before the VFS_VGET for the
638 * inode associated with ".." returns. We hope that this occurs
639 * infrequently since we cannot avoid this race condition without
640 * implementing a sophisticated deadlock detection algorithm.
641 * Note also that this simple deadlock detection scheme will not
642 * work if the file system has any hard links other than ".."
643 * that point backwards in the directory structure.
646 if (flags & CNP_ISDOTDOT) {
647 vn_unlock(pdp); /* race to get the inode */
648 if ((error = VFS_VGET(vdp->v_mount, NULL, dp->i_ino, &tdp)) != 0) {
649 vn_lock(pdp, LK_EXCLUSIVE | LK_RETRY);
652 if (lockparent && (error = vn_lock(pdp, LK_EXCLUSIVE))) {
657 } else if (dp->i_number == dp->i_ino) {
658 vref(vdp); /* we want ourself, ie "." */
661 if ((error = VFS_VGET(vdp->v_mount, NULL, dp->i_ino, &tdp)) != 0)
671 ext2_dirbad(struct inode *ip, doff_t offset, char *how)
675 mp = ITOV(ip)->v_mount;
676 kprintf("%s: bad dir ino %lu at offset %ld: %s\n",
677 mp->mnt_stat.f_mntfromname, (u_long)ip->i_number,
679 if ((mp->mnt_flag & MNT_RDONLY) == 0)
680 panic("ufs_dirbad: bad dir");
684 * Do consistency checking on a directory entry:
685 * record length must be multiple of 4
686 * entry must fit in rest of its DIRBLKSIZ block
687 * record must be large enough to contain entry
688 * name is not longer than MAXNAMLEN
689 * name must be as long as advertised, and null terminated
692 * changed so that it confirms to ext2_check_dir_entry
695 ext2_dirbadentry(struct vnode *dp, struct ext2_dir_entry_2 *de,
696 int entryoffsetinblock)
698 int DIRBLKSIZ = VTOI(dp)->i_e2fs->s_blocksize;
700 char * error_msg = NULL;
702 if (de->rec_len < EXT2_DIR_REC_LEN(1))
703 error_msg = "rec_len is smaller than minimal";
704 else if (de->rec_len % 4 != 0)
705 error_msg = "rec_len % 4 != 0";
706 else if (de->rec_len < EXT2_DIR_REC_LEN(de->name_len))
707 error_msg = "reclen is too small for name_len";
708 else if (entryoffsetinblock + de->rec_len > DIRBLKSIZ)
709 error_msg = "directory entry across blocks";
711 if (de->inode > dir->i_sb->u.ext2_sb.s_es->s_inodes_count)
712 error_msg = "inode out of bounds";
715 if (error_msg != NULL) {
716 kprintf("bad directory entry: %s\n", error_msg);
717 kprintf("offset=%d, inode=%lu, rec_len=%u, name_len=%u\n",
718 entryoffsetinblock, (unsigned long)de->inode,
719 de->rec_len, de->name_len);
721 return error_msg == NULL ? 0 : 1;
725 * Write a directory entry after a call to namei, using the parameters
726 * that it left in the directory inode. The argument ip is the inode which
727 * the new directory entry will refer to. Dvp is a pointer to the directory
728 * to be written, which was left locked by namei. Remaining parameters
729 * (dp->i_offset, dp->i_count) indicate how the space for the new
730 * entry is to be obtained.
733 ext2_direnter(struct inode *ip, struct vnode *dvp, struct componentname *cnp)
735 struct ext2_dir_entry_2 *ep, *nep;
738 struct ext2_dir_entry_2 newdir;
742 int error, loc, newentrysize, spacefree;
744 int DIRBLKSIZ = ip->i_e2fs->s_blocksize;
748 newdir.inode = ip->i_number;
749 newdir.name_len = cnp->cn_namelen;
750 if (EXT2_HAS_INCOMPAT_FEATURE(ip->i_e2fs->s_es,
751 EXT2_FEATURE_INCOMPAT_FILETYPE))
752 newdir.file_type = DTTOFT(IFTODT(ip->i_mode));
754 newdir.file_type = EXT2_FT_UNKNOWN;
755 bcopy(cnp->cn_nameptr, newdir.name, (unsigned)cnp->cn_namelen + 1);
756 newentrysize = EXT2_DIR_REC_LEN(newdir.name_len);
757 if (dp->i_count == 0) {
759 * If dp->i_count is 0, then namei could find no
760 * space in the directory. Here, dp->i_offset will
761 * be on a directory block boundary and we will write the
762 * new entry into a fresh block.
764 if (dp->i_offset & (DIRBLKSIZ - 1))
765 panic("ext2_direnter: newblk");
766 auio.uio_offset = dp->i_offset;
767 newdir.rec_len = DIRBLKSIZ;
768 auio.uio_resid = newentrysize;
769 aiov.iov_len = newentrysize;
770 aiov.iov_base = (caddr_t)&newdir;
771 auio.uio_iov = &aiov;
773 auio.uio_rw = UIO_WRITE;
774 auio.uio_segflg = UIO_SYSSPACE;
776 error = VOP_WRITE(dvp, &auio, IO_SYNC, cnp->cn_cred);
778 VFSTOEXT2(dvp->v_mount)->um_mountp->mnt_stat.f_bsize)
779 /* XXX should grow with balloc() */
780 panic("ext2_direnter: frag size");
782 dp->i_size = roundup(dp->i_size, DIRBLKSIZ);
783 dp->i_flag |= IN_CHANGE;
789 * If dp->i_count is non-zero, then namei found space
790 * for the new entry in the range dp->i_offset to
791 * dp->i_offset + dp->i_count in the directory.
792 * To use this space, we may have to compact the entries located
793 * there, by copying them together towards the beginning of the
794 * block, leaving the free space in one usable chunk at the end.
798 * Increase size of directory if entry eats into new space.
799 * This should never push the size past a new multiple of
802 * N.B. - THIS IS AN ARTIFACT OF 4.2 AND SHOULD NEVER HAPPEN.
804 if (dp->i_offset + dp->i_count > dp->i_size)
805 dp->i_size = dp->i_offset + dp->i_count;
807 * Get the block containing the space for the new directory entry.
809 if ((error = EXT2_BLKATOFF(dvp, (off_t)dp->i_offset, &dirbuf, &bp)) != 0)
812 * Find space for the new entry. In the simple case, the entry at
813 * offset base will have the space. If it does not, then namei
814 * arranged that compacting the region dp->i_offset to
815 * dp->i_offset + dp->i_count would yield the
818 ep = (struct ext2_dir_entry_2 *)dirbuf;
819 dsize = EXT2_DIR_REC_LEN(ep->name_len);
820 spacefree = ep->rec_len - dsize;
821 for (loc = ep->rec_len; loc < dp->i_count; ) {
822 nep = (struct ext2_dir_entry_2 *)(dirbuf + loc);
824 /* trim the existing slot */
826 ep = (struct ext2_dir_entry_2 *)((char *)ep + dsize);
828 /* overwrite; nothing there; header is ours */
831 dsize = EXT2_DIR_REC_LEN(nep->name_len);
832 spacefree += nep->rec_len - dsize;
834 bcopy((caddr_t)nep, (caddr_t)ep, dsize);
837 * Update the pointer fields in the previous entry (if any),
838 * copy in the new entry, and write out the block.
840 if (ep->inode == 0) {
841 if (spacefree + dsize < newentrysize)
842 panic("ext2_direnter: compact1");
843 newdir.rec_len = spacefree + dsize;
845 if (spacefree < newentrysize)
846 panic("ext2_direnter: compact2");
847 newdir.rec_len = spacefree;
849 ep = (struct ext2_dir_entry_2 *)((char *)ep + dsize);
851 bcopy((caddr_t)&newdir, (caddr_t)ep, (u_int)newentrysize);
853 dp->i_flag |= IN_CHANGE | IN_UPDATE;
854 if (!error && dp->i_endoff && dp->i_endoff < dp->i_size)
855 error = EXT2_TRUNCATE(dvp, (off_t)dp->i_endoff, IO_SYNC,
861 * Remove a directory entry after a call to namei, using
862 * the parameters which it left in the directory inode. The entry
863 * dp->i_offset contains the offset into the directory of the
864 * entry to be eliminated. The dp->i_count field contains the
865 * size of the previous record in the directory. If this
866 * is 0, the first entry is being deleted, so we need only
867 * zero the inode number to mark the entry as free. If the
868 * entry is not the first in the directory, we must reclaim
869 * the space of the now empty record by adding the record size
870 * to the size of the previous entry.
873 ext2_dirremove(struct vnode *dvp, struct componentname *cnp)
876 struct ext2_dir_entry_2 *ep;
881 if (dp->i_count == 0) {
883 * First entry in block: set d_ino to zero.
886 EXT2_BLKATOFF(dvp, (off_t)dp->i_offset, (char **)&ep, &bp)) != 0)
890 dp->i_flag |= IN_CHANGE | IN_UPDATE;
894 * Collapse new free space into previous entry.
896 if ((error = EXT2_BLKATOFF(dvp, (off_t)(dp->i_offset - dp->i_count),
897 (char **)&ep, &bp)) != 0)
899 ep->rec_len += dp->i_reclen;
901 dp->i_flag |= IN_CHANGE | IN_UPDATE;
906 * Rewrite an existing directory entry to point at the inode
907 * supplied. The parameters describing the directory entry are
908 * set up by a call to namei.
911 ext2_dirrewrite(struct inode *dp, struct inode *ip, struct componentname *cnp)
914 struct ext2_dir_entry_2 *ep;
915 struct vnode *vdp = ITOV(dp);
918 if ((error = EXT2_BLKATOFF(vdp, (off_t)dp->i_offset, (char **)&ep, &bp)) != 0)
920 ep->inode = ip->i_number;
921 if (EXT2_HAS_INCOMPAT_FEATURE(ip->i_e2fs->s_es,
922 EXT2_FEATURE_INCOMPAT_FILETYPE))
923 ep->file_type = DTTOFT(IFTODT(ip->i_mode));
925 ep->file_type = EXT2_FT_UNKNOWN;
927 dp->i_flag |= IN_CHANGE | IN_UPDATE;
932 * Check if a directory is empty or not.
933 * Inode supplied must be locked.
935 * Using a struct dirtemplate here is not precisely
936 * what we want, but better than using a struct direct.
938 * NB: does not handle corrupted directories.
941 ext2_dirempty(struct inode *ip, ino_t parentino, struct ucred *cred)
944 struct dirtemplate dbuf;
945 struct ext2_dir_entry_2 *dp = (struct ext2_dir_entry_2 *)&dbuf;
946 int error, count, namlen;
948 #define MINDIRSIZ (sizeof (struct dirtemplate) / 2)
950 for (off = 0; off < ip->i_size; off += dp->rec_len) {
951 error = vn_rdwr(UIO_READ, ITOV(ip), (caddr_t)dp, MINDIRSIZ, off,
952 UIO_SYSSPACE, IO_NODELOCKED, cred, &count);
954 * Since we read MINDIRSIZ, residual must
955 * be 0 unless we're at end of file.
957 if (error || count != 0)
959 /* avoid infinite loops */
960 if (dp->rec_len == 0)
962 /* skip empty entries */
965 /* accept only "." and ".." */
966 namlen = dp->name_len;
969 if (dp->name[0] != '.')
972 * At this point namlen must be 1 or 2.
973 * 1 implies ".", 2 implies ".." if second
978 if (dp->name[1] == '.' && dp->inode == parentino)
986 * Check if source directory is in the path of the target directory.
987 * Target is supplied locked, source is unlocked.
988 * The target is always vput before returning.
991 ext2_checkpath(struct inode *source, struct inode *target, struct ucred *cred)
994 int error, rootino, namlen;
995 struct dirtemplate dirbuf;
998 if (target->i_number == source->i_number) {
1004 if (target->i_number == rootino)
1008 if (vp->v_type != VDIR) {
1012 error = vn_rdwr(UIO_READ, vp, (caddr_t)&dirbuf,
1013 sizeof (struct dirtemplate), (off_t)0,
1014 UIO_SYSSPACE, IO_NODELOCKED, cred, NULL);
1017 namlen = dirbuf.dotdot_type; /* like ufs little-endian */
1019 dirbuf.dotdot_name[0] != '.' ||
1020 dirbuf.dotdot_name[1] != '.') {
1024 if (dirbuf.dotdot_ino == source->i_number) {
1028 if (dirbuf.dotdot_ino == rootino)
1031 if ((error = VFS_VGET(vp->v_mount, NULL, dirbuf.dotdot_ino, &vp)) != 0) {
1038 if (error == ENOTDIR)
1039 kprintf("checkpath: .. not a directory\n");