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38 * @(#)ufs_lookup.c 8.15 (Berkeley) 6/16/95
39 * $FreeBSD: src/sys/ufs/ufs/ufs_lookup.c,v 1.33.2.7 2001/09/22 19:22:13 iedowse Exp $
40 * $DragonFly: src/sys/vfs/ufs/ufs_lookup.c,v 1.29 2008/10/15 12:12:51 aggelos Exp $
45 #include <sys/param.h>
46 #include <sys/systm.h>
47 #include <sys/kernel.h>
50 #include <sys/namei.h>
52 #include <sys/mount.h>
53 #include <sys/vnode.h>
54 #include <sys/sysctl.h>
57 #include <vm/vm_extern.h>
66 #include "ufs_extern.h"
67 #include "ffs_extern.h"
75 SYSCTL_INT(_debug, OID_AUTO, dircheck, CTLFLAG_RW, &dirchk, 0,
76 "Enable full validation checks of directory");
78 /* true if old FS format...*/
79 #define OFSFMT(vp) ((vp)->v_mount->mnt_maxsymlinklen <= 0)
82 * Convert a component of a pathname into a pointer to a locked inode.
83 * This is a very central and rather complicated routine.
84 * If the filesystem is not maintained in a strict tree hierarchy,
85 * this can result in a deadlock situation (see comments in code below).
87 * The cnp->cn_nameiop argument is LOOKUP, CREATE, RENAME, or DELETE depending
88 * on whether the name is to be looked up, created, renamed, or deleted.
89 * When CREATE, RENAME, or DELETE is specified, information usable in
90 * creating, renaming, or deleting a directory entry may be calculated.
91 * If flag has LOCKPARENT or'ed into it and the target of the pathname
92 * exists, lookup returns both the target and its parent directory locked.
93 * When creating or renaming and LOCKPARENT is specified, the target may
94 * not be ".". When deleting and LOCKPARENT is specified, the target may
95 * be "."., but the caller must check to ensure it does an vrele and vput
96 * instead of two vputs.
98 * Overall outline of ufs_lookup:
100 * search for name in directory, to found or notfound
102 * if creating, return locked directory, leaving info on available slots
105 * if at end of path and deleting, return information to allow delete
106 * if at end of path and rewriting (RENAME and LOCKPARENT), lock target
107 * inode and return info to allow rewrite
108 * if not at end, add name to cache; if at end and neither creating
109 * nor deleting, add name to cache
111 * ufs_lookup(struct vnode *a_dvp, struct vnode **a_vpp,
112 * struct componentname *a_cnp)
115 ufs_lookup(struct vop_old_lookup_args *ap)
117 struct vnode *vdp; /* vnode for directory being searched */
118 struct inode *dp; /* inode for directory being searched */
119 struct buf *bp; /* a buffer of directory entries */
120 struct direct *ep; /* the current directory entry */
121 int entryoffsetinblock; /* offset of ep in bp's buffer */
122 enum {NONE, COMPACT, FOUND} slotstatus;
123 doff_t slotoffset; /* offset of area with free space */
124 int slotsize; /* size of area at slotoffset */
125 int slotfreespace; /* amount of space free in slot */
126 int slotneeded; /* size of the entry we're seeking */
127 int numdirpasses; /* strategy for directory search */
128 doff_t endsearch; /* offset to end directory search */
129 doff_t prevoff; /* prev entry dp->i_offset */
130 struct vnode *pdp; /* saved dp during symlink work */
131 struct vnode *tdp; /* returned by VFS_VGET */
132 doff_t enduseful; /* pointer past last used dir slot */
133 u_long bmask; /* block offset mask */
134 int lockparent; /* 1 => lockparent flag is set */
135 int wantparent; /* 1 => wantparent or lockparent flag */
137 struct vnode **vpp = ap->a_vpp;
138 struct componentname *cnp = ap->a_cnp;
139 struct ucred *cred = cnp->cn_cred;
140 int flags = cnp->cn_flags;
141 int nameiop = cnp->cn_nameiop;
145 cnp->cn_flags &= ~CNP_PDIRUNLOCK;
147 * XXX there was a soft-update diff about this I couldn't merge.
148 * I think this was the equiv.
154 lockparent = flags & CNP_LOCKPARENT;
155 wantparent = flags & (CNP_LOCKPARENT|CNP_WANTPARENT);
158 * We now have a segment name to search for, and a directory to search.
160 * Suppress search for slots unless creating
161 * file and at end of pathname, in which case
162 * we watch for a place to put the new file in
163 * case it doesn't already exist.
166 slotfreespace = slotsize = slotneeded = 0;
167 if (nameiop == NAMEI_CREATE || nameiop == NAMEI_RENAME) {
169 slotneeded = DIRECTSIZ(cnp->cn_namelen);
171 bmask = VFSTOUFS(vdp->v_mount)->um_mountp->mnt_stat.f_iosize - 1;
175 * Use dirhash for fast operations on large directories. The logic
176 * to determine whether to hash the directory is contained within
177 * ufsdirhash_build(); a zero return means that it decided to hash
178 * this directory and it successfully built up the hash table.
180 if (ufsdirhash_build(dp) == 0) {
181 /* Look for a free slot if needed. */
182 enduseful = dp->i_size;
183 if (slotstatus != FOUND) {
184 slotoffset = ufsdirhash_findfree(dp, slotneeded,
186 if (slotoffset >= 0) {
187 slotstatus = COMPACT;
188 enduseful = ufsdirhash_enduseful(dp);
190 enduseful = dp->i_size;
193 /* Look up the component. */
195 entryoffsetinblock = 0; /* silence compiler warning */
196 switch (ufsdirhash_lookup(dp, cnp->cn_nameptr, cnp->cn_namelen,
197 &dp->i_offset, &bp, nameiop == NAMEI_DELETE ? &prevoff : NULL)) {
199 ep = (struct direct *)((char *)bp->b_data +
200 (dp->i_offset & bmask));
203 dp->i_offset = roundup2(dp->i_size, DIRBLKSIZ);
206 /* Something failed; just do a linear search. */
210 #endif /* UFS_DIRHASH */
212 * If there is cached information on a previous search of
213 * this directory, pick up where we last left off.
214 * We cache only lookups as these are the most common
215 * and have the greatest payoff. Caching CREATE has little
216 * benefit as it usually must search the entire directory
217 * to determine that the entry does not exist. Caching the
218 * location of the last DELETE or RENAME has not reduced
219 * profiling time and hence has been removed in the interest
222 if (nameiop != NAMEI_LOOKUP || dp->i_diroff == 0 ||
223 dp->i_diroff >= dp->i_size) {
224 entryoffsetinblock = 0;
228 dp->i_offset = dp->i_diroff;
229 if ((entryoffsetinblock = dp->i_offset & bmask) &&
230 (error = ffs_blkatoff(vdp, (off_t)dp->i_offset, NULL, &bp)))
234 prevoff = dp->i_offset;
235 endsearch = roundup2(dp->i_size, DIRBLKSIZ);
239 while (dp->i_offset < endsearch) {
241 * If necessary, get the next directory block.
243 if ((dp->i_offset & bmask) == 0) {
247 ffs_blkatoff(vdp, (off_t)dp->i_offset, NULL, &bp);
250 entryoffsetinblock = 0;
253 * If still looking for a slot, and at a DIRBLKSIZE
254 * boundary, have to start looking for free space again.
256 if (slotstatus == NONE &&
257 (entryoffsetinblock & (DIRBLKSIZ - 1)) == 0) {
262 * Get pointer to next entry.
263 * Full validation checks are slow, so we only check
264 * enough to insure forward progress through the
265 * directory. Complete checks can be run by patching
266 * "dirchk" to be true.
268 ep = (struct direct *)((char *)bp->b_data + entryoffsetinblock);
269 if (ep->d_reclen == 0 || ep->d_reclen >
270 DIRBLKSIZ - (entryoffsetinblock & (DIRBLKSIZ - 1)) ||
271 (dirchk && ufs_dirbadentry(vdp, ep, entryoffsetinblock))) {
274 ufs_dirbad(dp, dp->i_offset, "mangled entry");
275 i = DIRBLKSIZ - (entryoffsetinblock & (DIRBLKSIZ - 1));
277 entryoffsetinblock += i;
282 * If an appropriate sized slot has not yet been found,
283 * check to see if one is available. Also accumulate space
284 * in the current block so that we can determine if
285 * compaction is viable.
287 if (slotstatus != FOUND) {
288 int size = ep->d_reclen;
291 size -= DIRSIZ(OFSFMT(vdp), ep);
293 if (size >= slotneeded) {
295 slotoffset = dp->i_offset;
296 slotsize = ep->d_reclen;
297 } else if (slotstatus == NONE) {
298 slotfreespace += size;
299 if (slotoffset == -1)
300 slotoffset = dp->i_offset;
301 if (slotfreespace >= slotneeded) {
302 slotstatus = COMPACT;
303 slotsize = dp->i_offset +
304 ep->d_reclen - slotoffset;
311 * Check for a name match.
314 # if (BYTE_ORDER == LITTLE_ENDIAN)
318 namlen = ep->d_namlen;
320 namlen = ep->d_namlen;
322 if (namlen == cnp->cn_namelen &&
323 (cnp->cn_nameptr[0] == ep->d_name[0]) &&
324 !bcmp(cnp->cn_nameptr, ep->d_name,
330 * Save directory entry's inode number and
331 * reclen in ndp->ni_ufs area, and release
334 if (vdp->v_mount->mnt_maxsymlinklen > 0 &&
335 ep->d_type == DT_WHT) {
337 slotoffset = dp->i_offset;
338 slotsize = ep->d_reclen;
339 dp->i_reclen = slotsize;
340 enduseful = dp->i_size;
341 ap->a_cnp->cn_flags |= CNP_ISWHITEOUT;
345 dp->i_ino = ep->d_ino;
346 dp->i_reclen = ep->d_reclen;
350 prevoff = dp->i_offset;
351 dp->i_offset += ep->d_reclen;
352 entryoffsetinblock += ep->d_reclen;
354 enduseful = dp->i_offset;
358 * If we started in the middle of the directory and failed
359 * to find our target, we must check the beginning as well.
361 if (numdirpasses == 2) {
364 endsearch = dp->i_diroff;
370 * If creating, and at end of pathname and current
371 * directory has not been removed, then can consider
372 * allowing file to be created.
374 if ((nameiop == NAMEI_CREATE || nameiop == NAMEI_RENAME ||
375 (nameiop == NAMEI_DELETE &&
376 (ap->a_cnp->cn_flags & CNP_DOWHITEOUT) &&
377 (ap->a_cnp->cn_flags & CNP_ISWHITEOUT))) &&
378 dp->i_effnlink != 0) {
380 * Access for write is interpreted as allowing
381 * creation of files in the directory.
383 error = VOP_EACCESS(vdp, VWRITE, cred);
387 * Return an indication of where the new directory
388 * entry should be put. If we didn't find a slot,
389 * then set dp->i_count to 0 indicating
390 * that the new slot belongs at the end of the
391 * directory. If we found a slot, then the new entry
392 * can be put in the range from dp->i_offset to
393 * dp->i_offset + dp->i_count.
395 if (slotstatus == NONE) {
396 dp->i_offset = roundup2(dp->i_size, DIRBLKSIZ);
398 enduseful = dp->i_offset;
399 } else if (nameiop == NAMEI_DELETE) {
400 dp->i_offset = slotoffset;
401 if ((dp->i_offset & (DIRBLKSIZ - 1)) == 0)
404 dp->i_count = dp->i_offset - prevoff;
406 dp->i_offset = slotoffset;
407 dp->i_count = slotsize;
408 if (enduseful < slotoffset + slotsize)
409 enduseful = slotoffset + slotsize;
411 dp->i_endoff = roundup2(enduseful, DIRBLKSIZ);
412 dp->i_flag |= IN_CHANGE | IN_UPDATE;
414 * We return with the directory locked, so that
415 * the parameters we set up above will still be
416 * valid if we actually decide to do a direnter().
417 * We return ni_vp == NULL to indicate that the entry
418 * does not currently exist; we leave a pointer to
419 * the (locked) directory inode in ndp->ni_dvp.
420 * The pathname buffer is saved so that the name
421 * can be obtained later.
423 * NB - if the directory is unlocked, then this
424 * information cannot be used.
428 cnp->cn_flags |= CNP_PDIRUNLOCK;
430 return (EJUSTRETURN);
436 * Check that directory length properly reflects presence
439 if (dp->i_offset + DIRSIZ(OFSFMT(vdp), ep) > dp->i_size) {
440 ufs_dirbad(dp, dp->i_offset, "i_size too small");
441 dp->i_size = dp->i_offset + DIRSIZ(OFSFMT(vdp), ep);
442 dp->i_flag |= IN_CHANGE | IN_UPDATE;
447 * Found component in pathname.
448 * If the final component of path name, save information
449 * in the cache as to where the entry was found.
451 if (nameiop == NAMEI_LOOKUP)
452 dp->i_diroff = dp->i_offset &~ (DIRBLKSIZ - 1);
455 * If deleting, and at end of pathname, return
456 * parameters which can be used to remove file.
457 * If the wantparent flag isn't set, we return only
458 * the directory (in ndp->ni_dvp), otherwise we go
459 * on and lock the inode, being careful with ".".
461 if (nameiop == NAMEI_DELETE) {
463 * Write access to directory required to delete files.
465 error = VOP_EACCESS(vdp, VWRITE, cred);
469 * Return pointer to current entry in dp->i_offset,
470 * and distance past previous entry (if there
471 * is a previous entry in this block) in dp->i_count.
472 * Save directory inode pointer in ndp->ni_dvp for dirremove().
474 if ((dp->i_offset & (DIRBLKSIZ - 1)) == 0)
477 dp->i_count = dp->i_offset - prevoff;
478 if (dp->i_number == dp->i_ino) {
483 if (flags & CNP_ISDOTDOT)
484 vn_unlock(vdp); /* race to get the inode */
485 error = VFS_VGET(vdp->v_mount, NULL, dp->i_ino, &tdp);
486 if (flags & CNP_ISDOTDOT) {
487 if (vn_lock(vdp, LK_EXCLUSIVE | LK_RETRY) != 0)
488 cnp->cn_flags |= CNP_PDIRUNLOCK;
493 * If directory is "sticky", then user must own
494 * the directory, or the file in it, else she
495 * may not delete it (unless she's root). This
496 * implements append-only directories.
498 if ((dp->i_mode & ISVTX) &&
500 cred->cr_uid != dp->i_uid &&
501 VTOI(tdp)->i_uid != cred->cr_uid) {
508 cnp->cn_flags |= CNP_PDIRUNLOCK;
514 * If rewriting (RENAME), return the inode and the
515 * information required to rewrite the present directory
516 * Must get inode of directory entry to verify it's a
517 * regular file, or empty directory.
519 if (nameiop == NAMEI_RENAME && wantparent) {
520 if ((error = VOP_EACCESS(vdp, VWRITE, cred)) != 0)
523 * Careful about locking second inode.
524 * This can only occur if the target is ".".
526 if (dp->i_number == dp->i_ino)
528 if (flags & CNP_ISDOTDOT)
529 vn_unlock(vdp); /* race to get the inode */
530 error = VFS_VGET(vdp->v_mount, NULL, dp->i_ino, &tdp);
531 if (flags & CNP_ISDOTDOT) {
532 if (vn_lock(vdp, LK_EXCLUSIVE | LK_RETRY) != 0)
533 cnp->cn_flags |= CNP_PDIRUNLOCK;
540 cnp->cn_flags |= CNP_PDIRUNLOCK;
546 * Step through the translation in the name. We do not `vput' the
547 * directory because we may need it again if a symbolic link
548 * is relative to the current directory. Instead we save it
549 * unlocked as "pdp". We must get the target inode before unlocking
550 * the directory to insure that the inode will not be removed
551 * before we get it. We prevent deadlock by always fetching
552 * inodes from the root, moving down the directory tree. Thus
553 * when following backward pointers ".." we must unlock the
554 * parent directory before getting the requested directory.
555 * There is a potential race condition here if both the current
556 * and parent directories are removed before the VFS_VGET for the
557 * inode associated with ".." returns. We hope that this occurs
558 * infrequently since we cannot avoid this race condition without
559 * implementing a sophisticated deadlock detection algorithm.
560 * Note also that this simple deadlock detection scheme will not
561 * work if the filesystem has any hard links other than ".."
562 * that point backwards in the directory structure.
565 if (flags & CNP_ISDOTDOT) {
566 vn_unlock(pdp); /* race to get the inode */
567 cnp->cn_flags |= CNP_PDIRUNLOCK;
568 error = VFS_VGET(vdp->v_mount, NULL, dp->i_ino, &tdp);
570 if (vn_lock(pdp, LK_EXCLUSIVE | LK_RETRY) == 0)
571 cnp->cn_flags &= ~CNP_PDIRUNLOCK;
575 if ((error = vn_lock(pdp, LK_EXCLUSIVE)) != 0) {
579 cnp->cn_flags &= ~CNP_PDIRUNLOCK;
582 } else if (dp->i_number == dp->i_ino) {
583 vref(vdp); /* we want ourself, ie "." */
586 error = VFS_VGET(vdp->v_mount, NULL, dp->i_ino, &tdp);
591 cnp->cn_flags |= CNP_PDIRUNLOCK;
599 ufs_dirbad(struct inode *ip, doff_t offset, char *how)
603 mp = ITOV(ip)->v_mount;
604 (void)kprintf("%s: bad dir ino %lu at offset %ld: %s\n",
605 mp->mnt_stat.f_mntfromname, (u_long)ip->i_number, (long)offset, how);
606 if ((mp->mnt_flag & MNT_RDONLY) == 0)
607 panic("ufs_dirbad: bad dir");
611 * Do consistency checking on a directory entry:
612 * record length must be multiple of 4
613 * entry must fit in rest of its DIRBLKSIZ block
614 * record must be large enough to contain entry
615 * name is not longer than MAXNAMLEN
616 * name must be as long as advertised, and null terminated
619 ufs_dirbadentry(struct vnode *dp, struct direct *ep, int entryoffsetinblock)
624 # if (BYTE_ORDER == LITTLE_ENDIAN)
628 namlen = ep->d_namlen;
630 namlen = ep->d_namlen;
632 if ((ep->d_reclen & 0x3) != 0 ||
633 ep->d_reclen > DIRBLKSIZ - (entryoffsetinblock & (DIRBLKSIZ - 1)) ||
634 ep->d_reclen < DIRSIZ(OFSFMT(dp), ep) || namlen > MAXNAMLEN) {
636 kprintf("First bad\n");
641 for (i = 0; i < namlen; i++)
642 if (ep->d_name[i] == '\0') {
644 kprintf("Second bad\n");
655 * Construct a new directory entry after a call to namei, using the
656 * parameters that it left in the componentname argument cnp. The
657 * argument ip is the inode to which the new directory entry will refer.
660 ufs_makedirentry(struct inode *ip, struct componentname *cnp,
661 struct direct *newdirp)
664 newdirp->d_ino = ip->i_number;
665 newdirp->d_namlen = cnp->cn_namelen;
666 bcopy(cnp->cn_nameptr, newdirp->d_name, (unsigned)cnp->cn_namelen + 1);
667 if (ITOV(ip)->v_mount->mnt_maxsymlinklen > 0)
668 newdirp->d_type = IFTODT(ip->i_mode);
671 # if (BYTE_ORDER == LITTLE_ENDIAN)
672 { u_char tmp = newdirp->d_namlen;
673 newdirp->d_namlen = newdirp->d_type;
674 newdirp->d_type = tmp; }
680 * Write a directory entry after a call to namei, using the parameters
681 * that it left in the directory inode. The argument dirp is the new directory
682 * entry contents. Dvp is a pointer to the directory to be written,
683 * which was left locked by namei. Remaining parameters (dp->i_offset,
684 * dp->i_count) indicate how the space for the new entry is to be obtained.
685 * Non-null bp indicates that a directory is being created (for the
686 * soft dependency code).
689 ufs_direnter(struct vnode *dvp, struct vnode *tvp, struct direct *dirp,
690 struct componentname *cnp, struct buf *newdirbp)
697 struct direct *ep, *nep;
698 int error, ret, blkoff, loc, spacefree, flags;
702 KKASSERT(cred != NULL);
705 newentrysize = DIRSIZ(OFSFMT(dvp), dirp);
707 if (dp->i_count == 0) {
709 * If dp->i_count is 0, then namei could find no
710 * space in the directory. Here, dp->i_offset will
711 * be on a directory block boundary and we will write the
712 * new entry into a fresh block.
714 if (dp->i_offset & (DIRBLKSIZ - 1))
715 panic("ufs_direnter: newblk");
716 nvnode_pager_setsize(dvp, dp->i_offset + DIRBLKSIZ,
719 if (!DOINGSOFTDEP(dvp) && !DOINGASYNC(dvp))
721 if ((error = VOP_BALLOC(dvp, (off_t)dp->i_offset, DIRBLKSIZ,
722 cred, flags, &bp)) != 0) {
723 if (DOINGSOFTDEP(dvp) && newdirbp != NULL)
727 dp->i_size = dp->i_offset + DIRBLKSIZ;
728 dp->i_flag |= IN_CHANGE | IN_UPDATE;
729 dirp->d_reclen = DIRBLKSIZ;
730 blkoff = dp->i_offset &
731 (VFSTOUFS(dvp->v_mount)->um_mountp->mnt_stat.f_iosize - 1);
732 bcopy((caddr_t)dirp, (caddr_t)bp->b_data + blkoff,newentrysize);
734 if (dp->i_dirhash != NULL) {
735 ufsdirhash_newblk(dp, dp->i_offset);
736 ufsdirhash_add(dp, dirp, dp->i_offset);
737 ufsdirhash_checkblock(dp, (char *)bp->b_data + blkoff,
741 if (DOINGSOFTDEP(dvp)) {
743 * Ensure that the entire newly allocated block is a
744 * valid directory so that future growth within the
745 * block does not have to ensure that the block is
746 * written before the inode.
749 while (blkoff < bp->b_bcount) {
751 (bp->b_data + blkoff))->d_reclen = DIRBLKSIZ;
754 softdep_setup_directory_add(bp, dp, dp->i_offset,
755 dirp->d_ino, newdirbp);
757 return (ffs_update(dvp, 0));
759 if (DOINGASYNC(dvp)) {
761 return (ffs_update(dvp, 0));
764 ret = ffs_update(dvp, 1);
771 * If dp->i_count is non-zero, then namei found space for the new
772 * entry in the range dp->i_offset to dp->i_offset + dp->i_count
773 * in the directory. To use this space, we may have to compact
774 * the entries located there, by copying them together towards the
775 * beginning of the block, leaving the free space in one usable
780 * Increase size of directory if entry eats into new space.
781 * This should never push the size past a new multiple of
784 * N.B. - THIS IS AN ARTIFACT OF 4.2 AND SHOULD NEVER HAPPEN.
786 if (dp->i_offset + dp->i_count > dp->i_size)
787 dp->i_size = dp->i_offset + dp->i_count;
789 * Get the block containing the space for the new directory entry.
791 error = ffs_blkatoff(dvp, (off_t)dp->i_offset, &dirbuf, &bp);
793 if (DOINGSOFTDEP(dvp) && newdirbp != NULL)
798 * Find space for the new entry. In the simple case, the entry at
799 * offset base will have the space. If it does not, then namei
800 * arranged that compacting the region dp->i_offset to
801 * dp->i_offset + dp->i_count would yield the space.
803 ep = (struct direct *)dirbuf;
804 dsize = ep->d_ino ? DIRSIZ(OFSFMT(dvp), ep) : 0;
805 spacefree = ep->d_reclen - dsize;
806 for (loc = ep->d_reclen; loc < dp->i_count; ) {
807 nep = (struct direct *)(dirbuf + loc);
809 /* Trim the existing slot (NB: dsize may be zero). */
810 ep->d_reclen = dsize;
811 ep = (struct direct *)((char *)ep + dsize);
813 /* Read nep->d_reclen now as the bcopy() may clobber it. */
814 loc += nep->d_reclen;
815 if (nep->d_ino == 0) {
817 * A mid-block unused entry. Such entries are
818 * never created by the kernel, but fsck_ffs
819 * can create them (and it doesn't fix them).
821 * Add up the free space, and initialise the
822 * relocated entry since we don't bcopy it.
824 spacefree += nep->d_reclen;
829 dsize = DIRSIZ(OFSFMT(dvp), nep);
830 spacefree += nep->d_reclen - dsize;
832 if (dp->i_dirhash != NULL)
833 ufsdirhash_move(dp, nep,
834 dp->i_offset + ((char *)nep - dirbuf),
835 dp->i_offset + ((char *)ep - dirbuf));
837 if (DOINGSOFTDEP(dvp))
838 softdep_change_directoryentry_offset(dp, dirbuf,
839 (caddr_t)nep, (caddr_t)ep, dsize);
841 bcopy((caddr_t)nep, (caddr_t)ep, dsize);
844 * Here, `ep' points to a directory entry containing `dsize' in-use
845 * bytes followed by `spacefree' unused bytes. If ep->d_ino == 0,
846 * then the entry is completely unused (dsize == 0). The value
847 * of ep->d_reclen is always indeterminate.
849 * Update the pointer fields in the previous entry (if any),
850 * copy in the new entry, and write out the block.
852 if (ep->d_ino == 0 ||
853 (ep->d_ino == WINO &&
854 bcmp(ep->d_name, dirp->d_name, dirp->d_namlen) == 0)) {
855 if (spacefree + dsize < newentrysize)
856 panic("ufs_direnter: compact1");
857 dirp->d_reclen = spacefree + dsize;
859 if (spacefree < newentrysize)
860 panic("ufs_direnter: compact2");
861 dirp->d_reclen = spacefree;
862 ep->d_reclen = dsize;
863 ep = (struct direct *)((char *)ep + dsize);
866 if (dp->i_dirhash != NULL && (ep->d_ino == 0 ||
867 dirp->d_reclen == spacefree))
868 ufsdirhash_add(dp, dirp, dp->i_offset + ((char *)ep - dirbuf));
870 bcopy((caddr_t)dirp, (caddr_t)ep, (uint)newentrysize);
872 if (dp->i_dirhash != NULL)
873 ufsdirhash_checkblock(dp, dirbuf -
874 (dp->i_offset & (DIRBLKSIZ - 1)),
875 dp->i_offset & ~(DIRBLKSIZ - 1));
878 if (DOINGSOFTDEP(dvp)) {
879 softdep_setup_directory_add(bp, dp,
880 dp->i_offset + (caddr_t)ep - dirbuf, dirp->d_ino, newdirbp);
883 if (DOINGASYNC(dvp)) {
890 dp->i_flag |= IN_CHANGE | IN_UPDATE;
892 * If all went well, and the directory can be shortened, proceed
893 * with the truncation. Note that we have to unlock the inode for
894 * the entry that we just entered, as the truncation may need to
895 * lock other inodes which can lead to deadlock if we also hold a
896 * lock on the newly entered node.
898 if (error == 0 && dp->i_endoff && dp->i_endoff < dp->i_size) {
902 if (dp->i_dirhash != NULL)
903 ufsdirhash_dirtrunc(dp, dp->i_endoff);
905 (void)ffs_truncate(dvp, (off_t)dp->i_endoff, IO_SYNC, cred);
907 vn_lock(tvp, LK_EXCLUSIVE | LK_RETRY);
913 * Remove a directory entry after a call to namei, using
914 * the parameters which it left in the directory inode. The entry
915 * dp->i_offset contains the offset into the directory of the
916 * entry to be eliminated. The dp->i_count field contains the
917 * size of the previous record in the directory. If this
918 * is 0, the first entry is being deleted, so we need only
919 * zero the inode number to mark the entry as free. If the
920 * entry is not the first in the directory, we must reclaim
921 * the space of the now empty record by adding the record size
922 * to the size of the previous entry.
925 ufs_dirremove(struct vnode *dvp, struct inode *ip, int flags, int isrmdir)
934 if (flags & CNP_DOWHITEOUT) {
936 * Whiteout entry: set d_ino to WINO.
939 ffs_blkatoff(dvp, (off_t)dp->i_offset, (char **)&ep, &bp)) != 0)
946 if ((error = ffs_blkatoff(dvp,
947 (off_t)(dp->i_offset - dp->i_count), (char **)&ep, &bp)) != 0)
951 * Remove the dirhash entry. This is complicated by the fact
952 * that `ep' is the previous entry when dp->i_count != 0.
954 if (dp->i_dirhash != NULL)
955 ufsdirhash_remove(dp, (dp->i_count == 0) ? ep :
956 (struct direct *)((char *)ep + ep->d_reclen), dp->i_offset);
958 if (dp->i_count == 0) {
960 * First entry in block: set d_ino to zero.
965 * Collapse new free space into previous entry.
967 ep->d_reclen += dp->i_reclen;
970 if (dp->i_dirhash != NULL)
971 ufsdirhash_checkblock(dp, (char *)ep -
972 ((dp->i_offset - dp->i_count) & (DIRBLKSIZ - 1)),
973 dp->i_offset & ~(DIRBLKSIZ - 1));
976 if (DOINGSOFTDEP(dvp)) {
979 softdep_change_linkcnt(ip);
980 softdep_setup_remove(bp, dp, ip, isrmdir);
982 if (softdep_slowdown(dvp)) {
992 ip->i_flag |= IN_CHANGE;
994 if (flags & CNP_DOWHITEOUT)
996 else if (DOINGASYNC(dvp) && dp->i_count != 0) {
1000 error = bowrite(bp);
1002 dp->i_flag |= IN_CHANGE | IN_UPDATE;
1007 * Rewrite an existing directory entry to point at the inode
1008 * supplied. The parameters describing the directory entry are
1009 * set up by a call to namei.
1012 ufs_dirrewrite(struct inode *dp, struct inode *oip, ino_t newinum, int newtype,
1017 struct vnode *vdp = ITOV(dp);
1020 error = ffs_blkatoff(vdp, (off_t)dp->i_offset, (char **)&ep, &bp);
1023 ep->d_ino = newinum;
1025 ep->d_type = newtype;
1027 if (DOINGSOFTDEP(vdp)) {
1028 softdep_change_linkcnt(oip);
1029 softdep_setup_directory_change(bp, dp, oip, newinum, isrmdir);
1033 oip->i_flag |= IN_CHANGE;
1034 if (DOINGASYNC(vdp)) {
1038 error = bowrite(bp);
1041 dp->i_flag |= IN_CHANGE | IN_UPDATE;
1046 * Check if a directory is empty or not.
1047 * Inode supplied must be locked.
1049 * Using a struct dirtemplate here is not precisely
1050 * what we want, but better than using a struct direct.
1052 * NB: does not handle corrupted directories.
1055 ufs_dirempty(struct inode *ip, ino_t parentino, struct ucred *cred)
1058 struct dirtemplate dbuf;
1059 struct direct *dp = (struct direct *)&dbuf;
1060 int error, count, namlen;
1061 #define MINDIRSIZ (sizeof (struct dirtemplate) / 2)
1063 for (off = 0; off < ip->i_size; off += dp->d_reclen) {
1064 error = vn_rdwr(UIO_READ, ITOV(ip), (caddr_t)dp, MINDIRSIZ, off,
1065 UIO_SYSSPACE, IO_NODELOCKED, cred, &count);
1067 * Since we read MINDIRSIZ, residual must
1068 * be 0 unless we're at end of file.
1070 if (error || count != 0)
1072 /* avoid infinite loops */
1073 if (dp->d_reclen == 0)
1075 /* skip empty entries */
1076 if (dp->d_ino == 0 || dp->d_ino == WINO)
1078 /* accept only "." and ".." */
1079 # if (BYTE_ORDER == LITTLE_ENDIAN)
1080 if (OFSFMT(ITOV(ip)))
1081 namlen = dp->d_type;
1083 namlen = dp->d_namlen;
1085 namlen = dp->d_namlen;
1089 if (dp->d_name[0] != '.')
1092 * At this point namlen must be 1 or 2.
1093 * 1 implies ".", 2 implies ".." if second
1096 if (namlen == 1 && dp->d_ino == ip->i_number)
1098 if (dp->d_name[1] == '.' && dp->d_ino == parentino)
1106 * Check if source directory is in the path of the target directory.
1107 * Target is supplied locked, source is unlocked.
1108 * The target is always vput before returning.
1111 ufs_checkpath(struct inode *source, struct inode *target, struct ucred *cred)
1114 int error, rootino, namlen;
1115 struct dirtemplate dirbuf;
1118 if (target->i_number == source->i_number) {
1124 if (target->i_number == rootino)
1128 if (vp->v_type != VDIR) {
1132 error = vn_rdwr(UIO_READ, vp, (caddr_t)&dirbuf,
1133 sizeof (struct dirtemplate), (off_t)0,
1134 UIO_SYSSPACE, IO_NODELOCKED, cred, NULL);
1137 # if (BYTE_ORDER == LITTLE_ENDIAN)
1139 namlen = dirbuf.dotdot_type;
1141 namlen = dirbuf.dotdot_namlen;
1143 namlen = dirbuf.dotdot_namlen;
1146 dirbuf.dotdot_name[0] != '.' ||
1147 dirbuf.dotdot_name[1] != '.') {
1151 if (dirbuf.dotdot_ino == source->i_number) {
1155 if (dirbuf.dotdot_ino == rootino)
1158 error = VFS_VGET(vp->v_mount, NULL, dirbuf.dotdot_ino, &vp);
1166 if (error == ENOTDIR)
1167 kprintf("checkpath: .. not a directory\n");