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. 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.
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
42 * @(#)ufs_lookup.c 8.6 (Berkeley) 4/1/94
45 #include <sys/param.h>
46 #include <sys/systm.h>
48 #include <sys/namei.h>
50 #include <sys/mount.h>
51 #include <sys/vnode.h>
52 #include <sys/malloc.h>
53 #include <sys/dirent.h>
58 #include "ext2_mount.h"
59 #include "ext2_extern.h"
61 #include "ext2_fs_sb.h"
64 DIRBLKSIZE in ffs is DEV_BSIZE (in most cases 512)
65 while it is the native blocksize in ext2fs - thus, a #define
66 is no longer appropriate
72 static u_char ext2_ft_to_dt[] = {
73 DT_UNKNOWN, /* EXT2_FT_UNKNOWN */
74 DT_REG, /* EXT2_FT_REG_FILE */
75 DT_DIR, /* EXT2_FT_DIR */
76 DT_CHR, /* EXT2_FT_CHRDEV */
77 DT_BLK, /* EXT2_FT_BLKDEV */
78 DT_FIFO, /* EXT2_FT_FIFO */
79 DT_SOCK, /* EXT2_FT_SOCK */
80 DT_LNK, /* EXT2_FT_SYMLINK */
83 ((ft) > NELEM(ext2_ft_to_dt) ? \
84 DT_UNKNOWN : ext2_ft_to_dt[(ft)])
86 static u_char dt_to_ext2_ft[] = {
87 EXT2_FT_UNKNOWN, /* DT_UNKNOWN */
88 EXT2_FT_FIFO, /* DT_FIFO */
89 EXT2_FT_CHRDEV, /* DT_CHR */
90 EXT2_FT_UNKNOWN, /* unused */
91 EXT2_FT_DIR, /* DT_DIR */
92 EXT2_FT_UNKNOWN, /* unused */
93 EXT2_FT_BLKDEV, /* DT_BLK */
94 EXT2_FT_UNKNOWN, /* unused */
95 EXT2_FT_REG_FILE, /* DT_REG */
96 EXT2_FT_UNKNOWN, /* unused */
97 EXT2_FT_SYMLINK, /* DT_LNK */
98 EXT2_FT_UNKNOWN, /* unused */
99 EXT2_FT_SOCK, /* DT_SOCK */
100 EXT2_FT_UNKNOWN, /* unused */
101 EXT2_FT_UNKNOWN, /* DT_WHT */
104 ((dt) > NELEM(dt_to_ext2_ft) ? \
105 EXT2_FT_UNKNOWN : dt_to_ext2_ft[(dt)])
107 static int ext2_dirbadentry (struct vnode *dp,
108 struct ext2_dir_entry_2 *de,
109 int entryoffsetinblock);
112 * Vnode op for reading directories.
114 * The routine below assumes that the on-disk format of a directory
115 * is the same as that defined by <sys/dirent.h>. If the on-disk
116 * format changes, then it will be necessary to do a conversion
117 * from the on-disk format that read returns to the format defined
121 * this is exactly what we do here - the problem is that the conversion
122 * will blow up some entries by four bytes, so it can't be done in place.
123 * This is too bad. Right now the conversion is done entry by entry, the
124 * converted entry is sent via uiomove.
126 * XXX allocate a buffer, convert as many entries as possible, then send
127 * the whole buffer to uiomove
129 * ext2_readdir(struct vnode *a_vp, struct uio *a_uio, struct ucred *a_cred)
132 ext2_readdir(struct vop_readdir_args *ap)
134 struct uio *uio = ap->a_uio;
136 struct ext2_dir_entry_2 *edp, *dp;
141 int DIRBLKSIZ = VTOI(ap->a_vp)->i_e2fs->s_blocksize;
143 off_t startoffset = uio->uio_offset;
145 error = vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY | LK_FAILRECLAIM);
149 count = uio->uio_resid;
151 * Avoid complications for partial directory entries by adjusting
152 * the i/o to end at a block boundary. Don't give up (like ufs
153 * does) if the initial adjustment gives a negative count, since
154 * many callers don't supply a large enough buffer. The correct
155 * size is a little larger than DIRBLKSIZ to allow for expansion
156 * of directory entries, but some callers just use 512.
158 count -= (uio->uio_offset + count) & (DIRBLKSIZ -1);
161 if (count > MAXBSIZE) /* limit to a reasonable size */
165 kprintf("ext2_readdir: uio_offset = %lld, uio_resid = %d, count = %d\n",
166 uio->uio_offset, uio->uio_resid, count);
170 auio.uio_iov = &aiov;
172 auio.uio_resid = count;
173 auio.uio_segflg = UIO_SYSSPACE;
174 aiov.iov_len = count;
175 dirbuf = kmalloc(count, M_TEMP, M_WAITOK);
176 aiov.iov_base = dirbuf;
177 error = VOP_READ(ap->a_vp, &auio, 0, ap->a_cred);
179 readcnt = count - auio.uio_resid;
180 edp = (struct ext2_dir_entry_2 *)&dirbuf[readcnt];
182 for (dp = (struct ext2_dir_entry_2 *)dirbuf;
183 !error && uio->uio_resid > 0 && dp < edp; ) {
185 * "New" ext2fs directory entries differ in 3 ways
186 * from ufs on-disk ones:
187 * - the name is not necessarily NUL-terminated.
188 * - the file type field always exists and always
189 * follows the name length field.
190 * - the file type is encoded in a different way.
192 * "Old" ext2fs directory entries need no special
193 * conversions, since they binary compatible with
194 * "new" entries having a file type of 0 (i.e.,
195 * EXT2_FT_UNKNOWN). Splitting the old name length
196 * field didn't make a mess like it did in ufs,
197 * because ext2fs uses a machine-dependent disk
200 if (dp->rec_len <= 0) {
204 retval = vop_write_dirent(&error, uio, dp->inode,
205 FTTODT(dp->file_type), dp->name_len, dp->name);
210 dp = (struct ext2_dir_entry_2 *)((char *)dp + dp->rec_len);
214 /* we need to correct uio_offset */
215 uio->uio_offset = startoffset + (caddr_t)dp - dirbuf;
217 if (!error && ap->a_ncookies != NULL) {
218 off_t *cookiep, *cookies, *ecookies;
221 if (uio->uio_segflg != UIO_SYSSPACE || uio->uio_iovcnt != 1)
222 panic("ext2fs_readdir: unexpected uio from NFS server");
224 cookies = kmalloc(ncookies * sizeof(off_t),
227 cookies = kmalloc(sizeof(off_t), M_TEMP,
231 for (dp = (struct ext2_dir_entry_2 *)dirbuf,
232 cookiep = cookies, ecookies = cookies + ncookies;
234 dp = (struct ext2_dir_entry_2 *)((caddr_t) dp + dp->rec_len)) {
238 *ap->a_ncookies = ncookies;
239 *ap->a_cookies = cookies;
242 kfree(dirbuf, M_TEMP);
244 *ap->a_eofflag = VTOI(ap->a_vp)->i_size <= uio->uio_offset;
250 * Convert a component of a pathname into a pointer to a locked inode.
251 * This is a very central and rather complicated routine.
252 * If the file system is not maintained in a strict tree hierarchy,
253 * this can result in a deadlock situation (see comments in code below).
255 * The cnp->cn_nameiop argument is LOOKUP, CREATE, RENAME, or DELETE depending
256 * on whether the name is to be looked up, created, renamed, or deleted.
257 * When CREATE, RENAME, or DELETE is specified, information usable in
258 * creating, renaming, or deleting a directory entry may be calculated.
259 * If flag has LOCKPARENT or'ed into it and the target of the pathname
260 * exists, lookup returns both the target and its parent directory locked.
261 * When creating or renaming and LOCKPARENT is specified, the target may
262 * not be ".". When deleting and LOCKPARENT is specified, the target may
263 * be "."., but the caller must check to ensure it does an vrele and vput
264 * instead of two vputs.
266 * Overall outline of ufs_lookup:
268 * search for name in directory, to found or notfound
270 * if creating, return locked directory, leaving info on available slots
273 * if at end of path and deleting, return information to allow delete
274 * if at end of path and rewriting (RENAME and LOCKPARENT), lock target
275 * inode and return info to allow rewrite
276 * if not at end, add name to cache; if at end and neither creating
277 * nor deleting, add name to cache
279 * ext2_lookup(struct vnode *a_dvp, struct vnode **a_vpp,
280 * struct componentname *a_cnp)
283 ext2_lookup(struct vop_old_lookup_args *ap)
285 struct vnode *vdp; /* vnode for directory being searched */
286 struct inode *dp; /* inode for directory being searched */
287 struct buf *bp; /* a buffer of directory entries */
288 struct ext2_dir_entry_2 *ep; /* the current directory entry */
289 int entryoffsetinblock; /* offset of ep in bp's buffer */
290 enum {NONE, COMPACT, FOUND} slotstatus;
291 doff_t slotoffset; /* offset of area with free space */
292 int slotsize; /* size of area at slotoffset */
293 int slotfreespace; /* amount of space free in slot */
294 int slotneeded; /* size of the entry we're seeking */
295 int numdirpasses; /* strategy for directory search */
296 doff_t endsearch; /* offset to end directory search */
297 doff_t prevoff; /* prev entry dp->i_offset */
298 struct vnode *pdp; /* saved dp during symlink work */
299 struct vnode *tdp; /* returned by VFS_VGET */
300 doff_t enduseful; /* pointer past last used dir slot */
301 u_long bmask; /* block offset mask */
302 int lockparent; /* 1 => lockparent flag is set */
303 int wantparent; /* 1 => wantparent or lockparent flag */
305 struct vnode **vpp = ap->a_vpp;
306 struct componentname *cnp = ap->a_cnp;
307 struct ucred *cred = cnp->cn_cred;
308 int flags = cnp->cn_flags;
309 int nameiop = cnp->cn_nameiop;
311 int DIRBLKSIZ = VTOI(ap->a_dvp)->i_e2fs->s_blocksize;
318 lockparent = flags & CNP_LOCKPARENT;
319 wantparent = flags & (CNP_LOCKPARENT|CNP_WANTPARENT);
322 * We now have a segment name to search for, and a directory to search.
326 * Suppress search for slots unless creating
327 * file and at end of pathname, in which case
328 * we watch for a place to put the new file in
329 * case it doesn't already exist.
332 slotfreespace = slotsize = slotneeded = 0;
333 if (nameiop == NAMEI_CREATE || nameiop == NAMEI_RENAME) {
335 slotneeded = EXT2_DIR_REC_LEN(cnp->cn_namelen);
337 slotneeded = (sizeof(struct direct) - MAXNAMLEN +
338 cnp->cn_namelen + 3) &~ 3; */
342 * If there is cached information on a previous search of
343 * this directory, pick up where we last left off.
344 * We cache only lookups as these are the most common
345 * and have the greatest payoff. Caching CREATE has little
346 * benefit as it usually must search the entire directory
347 * to determine that the entry does not exist. Caching the
348 * location of the last DELETE or RENAME has not reduced
349 * profiling time and hence has been removed in the interest
352 bmask = VFSTOEXT2(vdp->v_mount)->um_mountp->mnt_stat.f_iosize - 1;
353 if (nameiop != NAMEI_LOOKUP || dp->i_diroff == 0 ||
354 dp->i_diroff > dp->i_size) {
355 entryoffsetinblock = 0;
359 dp->i_offset = dp->i_diroff;
360 if ((entryoffsetinblock = dp->i_offset & bmask) &&
361 (error = EXT2_BLKATOFF(vdp, (off_t)dp->i_offset, NULL, &bp)))
365 prevoff = dp->i_offset;
366 endsearch = roundup(dp->i_size, DIRBLKSIZ);
370 while (dp->i_offset < endsearch) {
372 * If necessary, get the next directory block.
374 if ((dp->i_offset & bmask) == 0) {
378 EXT2_BLKATOFF(vdp, (off_t)dp->i_offset, NULL, &bp)) != 0)
380 entryoffsetinblock = 0;
383 * If still looking for a slot, and at a DIRBLKSIZE
384 * boundary, have to start looking for free space again.
386 if (slotstatus == NONE &&
387 (entryoffsetinblock & (DIRBLKSIZ - 1)) == 0) {
392 * Get pointer to next entry.
393 * Full validation checks are slow, so we only check
394 * enough to insure forward progress through the
395 * directory. Complete checks can be run by patching
396 * "dirchk" to be true.
398 ep = (struct ext2_dir_entry_2 *)
399 ((char *)bp->b_data + entryoffsetinblock);
400 if (ep->rec_len == 0 ||
401 (dirchk && ext2_dirbadentry(vdp, ep, entryoffsetinblock))) {
403 ext2_dirbad(dp, dp->i_offset, "mangled entry");
404 i = DIRBLKSIZ - (entryoffsetinblock & (DIRBLKSIZ - 1));
406 entryoffsetinblock += i;
411 * If an appropriate sized slot has not yet been found,
412 * check to see if one is available. Also accumulate space
413 * in the current block so that we can determine if
414 * compaction is viable.
416 if (slotstatus != FOUND) {
417 int size = ep->rec_len;
420 size -= EXT2_DIR_REC_LEN(ep->name_len);
422 if (size >= slotneeded) {
424 slotoffset = dp->i_offset;
425 slotsize = ep->rec_len;
426 } else if (slotstatus == NONE) {
427 slotfreespace += size;
428 if (slotoffset == -1)
429 slotoffset = dp->i_offset;
430 if (slotfreespace >= slotneeded) {
431 slotstatus = COMPACT;
432 slotsize = dp->i_offset +
433 ep->rec_len - slotoffset;
440 * Check for a name match.
443 namlen = ep->name_len;
444 if (namlen == cnp->cn_namelen &&
445 !bcmp(cnp->cn_nameptr, ep->name,
448 * Save directory entry's inode number and
449 * reclen in ndp->ni_ufs area, and release
452 dp->i_ino = ep->inode;
453 dp->i_reclen = ep->rec_len;
457 prevoff = dp->i_offset;
458 dp->i_offset += ep->rec_len;
459 entryoffsetinblock += ep->rec_len;
461 enduseful = dp->i_offset;
465 * If we started in the middle of the directory and failed
466 * to find our target, we must check the beginning as well.
468 if (numdirpasses == 2) {
471 endsearch = dp->i_diroff;
477 * If creating, and at end of pathname and current
478 * directory has not been removed, then can consider
479 * allowing file to be created.
481 if ((nameiop == NAMEI_CREATE || nameiop == NAMEI_RENAME) &&
484 * Access for write is interpreted as allowing
485 * creation of files in the directory.
487 if ((error = VOP_EACCESS(vdp, VWRITE, cred)) != 0)
490 * Return an indication of where the new directory
491 * entry should be put. If we didn't find a slot,
492 * then set dp->i_count to 0 indicating
493 * that the new slot belongs at the end of the
494 * directory. If we found a slot, then the new entry
495 * can be put in the range from dp->i_offset to
496 * dp->i_offset + dp->i_count.
498 if (slotstatus == NONE) {
499 dp->i_offset = roundup(dp->i_size, DIRBLKSIZ);
501 enduseful = dp->i_offset;
503 dp->i_offset = slotoffset;
504 dp->i_count = slotsize;
505 if (enduseful < slotoffset + slotsize)
506 enduseful = slotoffset + slotsize;
508 dp->i_endoff = roundup(enduseful, DIRBLKSIZ);
509 dp->i_flag |= IN_CHANGE | IN_UPDATE;
511 * We return with the directory locked, so that
512 * the parameters we set up above will still be
513 * valid if we actually decide to do a direnter().
514 * We return ni_vp == NULL to indicate that the entry
515 * does not currently exist; we leave a pointer to
516 * the (locked) directory inode in ndp->ni_dvp.
517 * The pathname buffer is saved so that the name
518 * can be obtained later.
520 * NB - if the directory is unlocked, then this
521 * information cannot be used.
525 return (EJUSTRETURN);
531 * Check that directory length properly reflects presence
534 if (entryoffsetinblock + EXT2_DIR_REC_LEN(ep->name_len)
536 ext2_dirbad(dp, dp->i_offset, "i_size too small");
537 dp->i_size = entryoffsetinblock+EXT2_DIR_REC_LEN(ep->name_len);
538 dp->i_flag |= IN_CHANGE | IN_UPDATE;
543 * Found component in pathname.
544 * If the final component of path name, save information
545 * in the cache as to where the entry was found.
547 if (nameiop == NAMEI_LOOKUP)
548 dp->i_diroff = rounddown2(dp->i_offset, DIRBLKSIZ);
551 * If deleting, and at end of pathname, return
552 * parameters which can be used to remove file.
553 * If the wantparent flag isn't set, we return only
554 * the directory (in ndp->ni_dvp), otherwise we go
555 * on and lock the inode, being careful with ".".
557 if (nameiop == NAMEI_DELETE) {
559 * Write access to directory required to delete files.
561 if ((error = VOP_EACCESS(vdp, VWRITE, cred)) != 0)
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().
569 if ((dp->i_offset & (DIRBLKSIZ - 1)) == 0)
572 dp->i_count = dp->i_offset - prevoff;
573 if (dp->i_number == dp->i_ino) {
578 if ((error = VFS_VGET(vdp->v_mount, NULL, dp->i_ino, &tdp)) != 0)
581 * If directory is "sticky", then user must own
582 * the directory, or the file in it, else she
583 * may not delete it (unless she's root). This
584 * implements append-only directories.
586 if ((dp->i_mode & ISVTX) &&
588 cred->cr_uid != dp->i_uid &&
589 VTOI(tdp)->i_uid != cred->cr_uid) {
600 * If rewriting (RENAME), return the inode and the
601 * information required to rewrite the present directory
602 * Must get inode of directory entry to verify it's a
603 * regular file, or empty directory.
605 if (nameiop == NAMEI_RENAME && wantparent) {
606 if ((error = VOP_EACCESS(vdp, VWRITE, cred)) != 0)
609 * Careful about locking second inode.
610 * This can only occur if the target is ".".
612 if (dp->i_number == dp->i_ino)
614 if ((error = VFS_VGET(vdp->v_mount, NULL, dp->i_ino, &tdp)) != 0)
623 * Step through the translation in the name. We do not `vput' the
624 * directory because we may need it again if a symbolic link
625 * is relative to the current directory. Instead we save it
626 * unlocked as "pdp". We must get the target inode before unlocking
627 * the directory to insure that the inode will not be removed
628 * before we get it. We prevent deadlock by always fetching
629 * inodes from the root, moving down the directory tree. Thus
630 * when following backward pointers ".." we must unlock the
631 * parent directory before getting the requested directory.
632 * There is a potential race condition here if both the current
633 * and parent directories are removed before the VFS_VGET for the
634 * inode associated with ".." returns. We hope that this occurs
635 * infrequently since we cannot avoid this race condition without
636 * implementing a sophisticated deadlock detection algorithm.
637 * Note also that this simple deadlock detection scheme will not
638 * work if the file system has any hard links other than ".."
639 * that point backwards in the directory structure.
642 if (flags & CNP_ISDOTDOT) {
643 vn_unlock(pdp); /* race to get the inode */
644 error = VFS_VGET(vdp->v_mount, NULL, dp->i_ino, &tdp);
646 vn_lock(pdp, LK_EXCLUSIVE | LK_RETRY);
650 error = vn_lock(pdp, LK_EXCLUSIVE | LK_FAILRECLAIM);
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)
665 cnp->cn_flags |= CNP_PDIRUNLOCK;
673 ext2_dirbad(struct inode *ip, doff_t offset, char *how)
677 mp = ITOV(ip)->v_mount;
678 kprintf("%s: bad dir ino %lu at offset %ld: %s\n",
679 mp->mnt_stat.f_mntfromname, (u_long)ip->i_number,
681 if ((mp->mnt_flag & MNT_RDONLY) == 0)
682 panic("ufs_dirbad: bad dir");
686 * Do consistency checking on a directory entry:
687 * record length must be multiple of 4
688 * entry must fit in rest of its DIRBLKSIZ block
689 * record must be large enough to contain entry
690 * name is not longer than MAXNAMLEN
691 * name must be as long as advertised, and null terminated
694 * changed so that it confirms to ext2_check_dir_entry
697 ext2_dirbadentry(struct vnode *dp, struct ext2_dir_entry_2 *de,
698 int entryoffsetinblock)
700 int DIRBLKSIZ = VTOI(dp)->i_e2fs->s_blocksize;
702 char *error_msg = NULL;
704 if (de->rec_len < EXT2_DIR_REC_LEN(1))
705 error_msg = "rec_len is smaller than minimal";
706 else if (de->rec_len % 4 != 0)
707 error_msg = "rec_len % 4 != 0";
708 else if (de->rec_len < EXT2_DIR_REC_LEN(de->name_len))
709 error_msg = "reclen is too small for name_len";
710 else if (entryoffsetinblock + de->rec_len > DIRBLKSIZ)
711 error_msg = "directory entry across blocks";
713 if (de->inode > dir->i_sb->u.ext2_sb.s_es->s_inodes_count)
714 error_msg = "inode out of bounds";
717 if (error_msg != NULL) {
718 kprintf("bad directory entry: %s\n", error_msg);
719 kprintf("offset=%d, inode=%lu, rec_len=%u, name_len=%u\n",
720 entryoffsetinblock, (unsigned long)de->inode,
721 de->rec_len, de->name_len);
723 return error_msg == NULL ? 0 : 1;
727 * Write a directory entry after a call to namei, using the parameters
728 * that it left in the directory inode. The argument ip is the inode which
729 * the new directory entry will refer to. Dvp is a pointer to the directory
730 * to be written, which was left locked by namei. Remaining parameters
731 * (dp->i_offset, dp->i_count) indicate how the space for the new
732 * entry is to be obtained.
735 ext2_direnter(struct inode *ip, struct vnode *dvp, struct componentname *cnp)
737 struct ext2_dir_entry_2 *ep, *nep;
740 struct ext2_dir_entry_2 newdir;
744 int error, loc, newentrysize, spacefree;
746 int DIRBLKSIZ = ip->i_e2fs->s_blocksize;
750 newdir.inode = ip->i_number;
751 newdir.name_len = cnp->cn_namelen;
752 if (EXT2_HAS_INCOMPAT_FEATURE(ip->i_e2fs->s_es,
753 EXT2_FEATURE_INCOMPAT_FILETYPE))
754 newdir.file_type = DTTOFT(IFTODT(ip->i_mode));
756 newdir.file_type = EXT2_FT_UNKNOWN;
757 bcopy(cnp->cn_nameptr, newdir.name, (unsigned)cnp->cn_namelen + 1);
758 newentrysize = EXT2_DIR_REC_LEN(newdir.name_len);
759 if (dp->i_count == 0) {
761 * If dp->i_count is 0, then namei could find no
762 * space in the directory. Here, dp->i_offset will
763 * be on a directory block boundary and we will write the
764 * new entry into a fresh block.
766 if (dp->i_offset & (DIRBLKSIZ - 1))
767 panic("ext2_direnter: newblk");
768 auio.uio_offset = dp->i_offset;
769 newdir.rec_len = DIRBLKSIZ;
770 auio.uio_resid = newentrysize;
771 aiov.iov_len = newentrysize;
772 aiov.iov_base = (caddr_t)&newdir;
773 auio.uio_iov = &aiov;
775 auio.uio_rw = UIO_WRITE;
776 auio.uio_segflg = UIO_SYSSPACE;
778 error = VOP_WRITE(dvp, &auio, IO_SYNC, cnp->cn_cred);
780 VFSTOEXT2(dvp->v_mount)->um_mountp->mnt_stat.f_bsize)
781 /* XXX should grow with balloc() */
782 panic("ext2_direnter: frag size");
784 dp->i_size = roundup(dp->i_size, DIRBLKSIZ);
785 dp->i_flag |= IN_CHANGE;
791 * If dp->i_count is non-zero, then namei found space
792 * for the new entry in the range dp->i_offset to
793 * dp->i_offset + dp->i_count in the directory.
794 * To use this space, we may have to compact the entries located
795 * there, by copying them together towards the beginning of the
796 * block, leaving the free space in one usable chunk at the end.
800 * Increase size of directory if entry eats into new space.
801 * This should never push the size past a new multiple of
804 * N.B. - THIS IS AN ARTIFACT OF 4.2 AND SHOULD NEVER HAPPEN.
806 if (dp->i_offset + dp->i_count > dp->i_size)
807 dp->i_size = dp->i_offset + dp->i_count;
809 * Get the block containing the space for the new directory entry.
811 if ((error = EXT2_BLKATOFF(dvp, (off_t)dp->i_offset, &dirbuf, &bp)) != 0)
814 * Find space for the new entry. In the simple case, the entry at
815 * offset base will have the space. If it does not, then namei
816 * arranged that compacting the region dp->i_offset to
817 * dp->i_offset + dp->i_count would yield the
820 ep = (struct ext2_dir_entry_2 *)dirbuf;
821 dsize = EXT2_DIR_REC_LEN(ep->name_len);
822 spacefree = ep->rec_len - dsize;
823 for (loc = ep->rec_len; loc < dp->i_count; ) {
824 nep = (struct ext2_dir_entry_2 *)(dirbuf + loc);
826 /* trim the existing slot */
828 ep = (struct ext2_dir_entry_2 *)((char *)ep + dsize);
830 /* overwrite; nothing there; header is ours */
833 dsize = EXT2_DIR_REC_LEN(nep->name_len);
834 spacefree += nep->rec_len - dsize;
836 bcopy((caddr_t)nep, (caddr_t)ep, dsize);
839 * Update the pointer fields in the previous entry (if any),
840 * copy in the new entry, and write out the block.
842 if (ep->inode == 0) {
843 if (spacefree + dsize < newentrysize)
844 panic("ext2_direnter: compact1");
845 newdir.rec_len = spacefree + dsize;
847 if (spacefree < newentrysize)
848 panic("ext2_direnter: compact2");
849 newdir.rec_len = spacefree;
851 ep = (struct ext2_dir_entry_2 *)((char *)ep + dsize);
853 bcopy((caddr_t)&newdir, (caddr_t)ep, (u_int)newentrysize);
855 dp->i_flag |= IN_CHANGE | IN_UPDATE;
856 if (!error && dp->i_endoff && dp->i_endoff < dp->i_size)
857 error = EXT2_TRUNCATE(dvp, (off_t)dp->i_endoff, IO_SYNC,
863 * Remove a directory entry after a call to namei, using
864 * the parameters which it left in the directory inode. The entry
865 * dp->i_offset contains the offset into the directory of the
866 * entry to be eliminated. The dp->i_count field contains the
867 * size of the previous record in the directory. If this
868 * is 0, the first entry is being deleted, so we need only
869 * zero the inode number to mark the entry as free. If the
870 * entry is not the first in the directory, we must reclaim
871 * the space of the now empty record by adding the record size
872 * to the size of the previous entry.
875 ext2_dirremove(struct vnode *dvp, struct componentname *cnp)
878 struct ext2_dir_entry_2 *ep;
883 if (dp->i_count == 0) {
885 * First entry in block: set d_ino to zero.
888 EXT2_BLKATOFF(dvp, (off_t)dp->i_offset, (char **)&ep, &bp)) != 0)
892 dp->i_flag |= IN_CHANGE | IN_UPDATE;
896 * Collapse new free space into previous entry.
898 if ((error = EXT2_BLKATOFF(dvp, (off_t)(dp->i_offset - dp->i_count),
899 (char **)&ep, &bp)) != 0)
901 ep->rec_len += dp->i_reclen;
903 dp->i_flag |= IN_CHANGE | IN_UPDATE;
908 * Rewrite an existing directory entry to point at the inode
909 * supplied. The parameters describing the directory entry are
910 * set up by a call to namei.
913 ext2_dirrewrite(struct inode *dp, struct inode *ip, struct componentname *cnp)
916 struct ext2_dir_entry_2 *ep;
917 struct vnode *vdp = ITOV(dp);
920 if ((error = EXT2_BLKATOFF(vdp, (off_t)dp->i_offset, (char **)&ep, &bp)) != 0)
922 ep->inode = ip->i_number;
923 if (EXT2_HAS_INCOMPAT_FEATURE(ip->i_e2fs->s_es,
924 EXT2_FEATURE_INCOMPAT_FILETYPE))
925 ep->file_type = DTTOFT(IFTODT(ip->i_mode));
927 ep->file_type = EXT2_FT_UNKNOWN;
929 dp->i_flag |= IN_CHANGE | IN_UPDATE;
934 * Check if a directory is empty or not.
935 * Inode supplied must be locked.
937 * Using a struct dirtemplate here is not precisely
938 * what we want, but better than using a struct direct.
940 * NB: does not handle corrupted directories.
943 ext2_dirempty(struct inode *ip, ino_t parentino, struct ucred *cred)
946 struct dirtemplate dbuf;
947 struct ext2_dir_entry_2 *dp = (struct ext2_dir_entry_2 *)&dbuf;
948 int error, count, namlen;
950 #define MINDIRSIZ (sizeof (struct dirtemplate) / 2)
952 for (off = 0; off < ip->i_size; off += dp->rec_len) {
953 error = vn_rdwr(UIO_READ, ITOV(ip), (caddr_t)dp, MINDIRSIZ, off,
954 UIO_SYSSPACE, IO_NODELOCKED, cred, &count);
956 * Since we read MINDIRSIZ, residual must
957 * be 0 unless we're at end of file.
959 if (error || count != 0)
961 /* avoid infinite loops */
962 if (dp->rec_len == 0)
964 /* skip empty entries */
967 /* accept only "." and ".." */
968 namlen = dp->name_len;
971 if (dp->name[0] != '.')
974 * At this point namlen must be 1 or 2.
975 * 1 implies ".", 2 implies ".." if second
980 if (dp->name[1] == '.' && dp->inode == parentino)
988 * Check if source directory is in the path of the target directory.
989 * Target is supplied locked, source is unlocked.
990 * The target is always vput before returning.
993 ext2_checkpath(struct inode *source, struct inode *target, struct ucred *cred)
996 int error, rootino, namlen;
997 struct dirtemplate dirbuf;
1000 if (target->i_number == source->i_number) {
1004 rootino = EXT2_ROOTINO;
1006 if (target->i_number == rootino)
1010 if (vp->v_type != VDIR) {
1014 error = vn_rdwr(UIO_READ, vp, (caddr_t)&dirbuf,
1015 sizeof (struct dirtemplate), (off_t)0,
1016 UIO_SYSSPACE, IO_NODELOCKED, cred, NULL);
1019 namlen = dirbuf.dotdot_type; /* like ufs little-endian */
1021 dirbuf.dotdot_name[0] != '.' ||
1022 dirbuf.dotdot_name[1] != '.') {
1026 if (dirbuf.dotdot_ino == source->i_number) {
1030 if (dirbuf.dotdot_ino == rootino)
1033 if ((error = VFS_VGET(vp->v_mount, NULL, dirbuf.dotdot_ino, &vp)) != 0) {
1040 if (error == ENOTDIR)
1041 kprintf("checkpath: .. not a directory\n");