2 * Copyright (c) 1989, 1993
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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, "");
77 /* true if old FS format...*/
78 #define OFSFMT(vp) ((vp)->v_mount->mnt_maxsymlinklen <= 0)
81 * Convert a component of a pathname into a pointer to a locked inode.
82 * This is a very central and rather complicated routine.
83 * If the filesystem is not maintained in a strict tree hierarchy,
84 * this can result in a deadlock situation (see comments in code below).
86 * The cnp->cn_nameiop argument is LOOKUP, CREATE, RENAME, or DELETE depending
87 * on whether the name is to be looked up, created, renamed, or deleted.
88 * When CREATE, RENAME, or DELETE is specified, information usable in
89 * creating, renaming, or deleting a directory entry may be calculated.
90 * If flag has LOCKPARENT or'ed into it and the target of the pathname
91 * exists, lookup returns both the target and its parent directory locked.
92 * When creating or renaming and LOCKPARENT is specified, the target may
93 * not be ".". When deleting and LOCKPARENT is specified, the target may
94 * be "."., but the caller must check to ensure it does an vrele and vput
95 * instead of two vputs.
97 * Overall outline of ufs_lookup:
99 * search for name in directory, to found or notfound
101 * if creating, return locked directory, leaving info on available slots
104 * if at end of path and deleting, return information to allow delete
105 * if at end of path and rewriting (RENAME and LOCKPARENT), lock target
106 * inode and return info to allow rewrite
107 * if not at end, add name to cache; if at end and neither creating
108 * nor deleting, add name to cache
110 * ufs_lookup(struct vnode *a_dvp, struct vnode **a_vpp,
111 * struct componentname *a_cnp)
114 ufs_lookup(struct vop_old_lookup_args *ap)
116 struct vnode *vdp; /* vnode for directory being searched */
117 struct inode *dp; /* inode for directory being searched */
118 struct buf *bp; /* a buffer of directory entries */
119 struct direct *ep; /* the current directory entry */
120 int entryoffsetinblock; /* offset of ep in bp's buffer */
121 enum {NONE, COMPACT, FOUND} slotstatus;
122 doff_t slotoffset; /* offset of area with free space */
123 int slotsize; /* size of area at slotoffset */
124 int slotfreespace; /* amount of space free in slot */
125 int slotneeded; /* size of the entry we're seeking */
126 int numdirpasses; /* strategy for directory search */
127 doff_t endsearch; /* offset to end directory search */
128 doff_t prevoff; /* prev entry dp->i_offset */
129 struct vnode *pdp; /* saved dp during symlink work */
130 struct vnode *tdp; /* returned by VFS_VGET */
131 doff_t enduseful; /* pointer past last used dir slot */
132 u_long bmask; /* block offset mask */
133 int lockparent; /* 1 => lockparent flag is set */
134 int wantparent; /* 1 => wantparent or lockparent flag */
136 struct vnode **vpp = ap->a_vpp;
137 struct componentname *cnp = ap->a_cnp;
138 struct ucred *cred = cnp->cn_cred;
139 int flags = cnp->cn_flags;
140 int nameiop = cnp->cn_nameiop;
144 cnp->cn_flags &= ~CNP_PDIRUNLOCK;
146 * XXX there was a soft-update diff about this I couldn't merge.
147 * I think this was the equiv.
153 lockparent = flags & CNP_LOCKPARENT;
154 wantparent = flags & (CNP_LOCKPARENT|CNP_WANTPARENT);
157 * We now have a segment name to search for, and a directory to search.
159 * Suppress search for slots unless creating
160 * file and at end of pathname, in which case
161 * we watch for a place to put the new file in
162 * case it doesn't already exist.
165 slotfreespace = slotsize = slotneeded = 0;
166 if (nameiop == NAMEI_CREATE || nameiop == NAMEI_RENAME) {
168 slotneeded = DIRECTSIZ(cnp->cn_namelen);
170 bmask = VFSTOUFS(vdp->v_mount)->um_mountp->mnt_stat.f_iosize - 1;
174 * Use dirhash for fast operations on large directories. The logic
175 * to determine whether to hash the directory is contained within
176 * ufsdirhash_build(); a zero return means that it decided to hash
177 * this directory and it successfully built up the hash table.
179 if (ufsdirhash_build(dp) == 0) {
180 /* Look for a free slot if needed. */
181 enduseful = dp->i_size;
182 if (slotstatus != FOUND) {
183 slotoffset = ufsdirhash_findfree(dp, slotneeded,
185 if (slotoffset >= 0) {
186 slotstatus = COMPACT;
187 enduseful = ufsdirhash_enduseful(dp);
189 enduseful = dp->i_size;
192 /* Look up the component. */
194 entryoffsetinblock = 0; /* silence compiler warning */
195 switch (ufsdirhash_lookup(dp, cnp->cn_nameptr, cnp->cn_namelen,
196 &dp->i_offset, &bp, nameiop == NAMEI_DELETE ? &prevoff : NULL)) {
198 ep = (struct direct *)((char *)bp->b_data +
199 (dp->i_offset & bmask));
202 dp->i_offset = roundup2(dp->i_size, DIRBLKSIZ);
205 /* Something failed; just do a linear search. */
209 #endif /* UFS_DIRHASH */
211 * If there is cached information on a previous search of
212 * this directory, pick up where we last left off.
213 * We cache only lookups as these are the most common
214 * and have the greatest payoff. Caching CREATE has little
215 * benefit as it usually must search the entire directory
216 * to determine that the entry does not exist. Caching the
217 * location of the last DELETE or RENAME has not reduced
218 * profiling time and hence has been removed in the interest
221 if (nameiop != NAMEI_LOOKUP || dp->i_diroff == 0 ||
222 dp->i_diroff >= dp->i_size) {
223 entryoffsetinblock = 0;
227 dp->i_offset = dp->i_diroff;
228 if ((entryoffsetinblock = dp->i_offset & bmask) &&
229 (error = ffs_blkatoff(vdp, (off_t)dp->i_offset, NULL, &bp)))
233 prevoff = dp->i_offset;
234 endsearch = roundup2(dp->i_size, DIRBLKSIZ);
238 while (dp->i_offset < endsearch) {
240 * If necessary, get the next directory block.
242 if ((dp->i_offset & bmask) == 0) {
246 ffs_blkatoff(vdp, (off_t)dp->i_offset, NULL, &bp);
249 entryoffsetinblock = 0;
252 * If still looking for a slot, and at a DIRBLKSIZE
253 * boundary, have to start looking for free space again.
255 if (slotstatus == NONE &&
256 (entryoffsetinblock & (DIRBLKSIZ - 1)) == 0) {
261 * Get pointer to next entry.
262 * Full validation checks are slow, so we only check
263 * enough to insure forward progress through the
264 * directory. Complete checks can be run by patching
265 * "dirchk" to be true.
267 ep = (struct direct *)((char *)bp->b_data + entryoffsetinblock);
268 if (ep->d_reclen == 0 || ep->d_reclen >
269 DIRBLKSIZ - (entryoffsetinblock & (DIRBLKSIZ - 1)) ||
270 (dirchk && ufs_dirbadentry(vdp, ep, entryoffsetinblock))) {
273 ufs_dirbad(dp, dp->i_offset, "mangled entry");
274 i = DIRBLKSIZ - (entryoffsetinblock & (DIRBLKSIZ - 1));
276 entryoffsetinblock += i;
281 * If an appropriate sized slot has not yet been found,
282 * check to see if one is available. Also accumulate space
283 * in the current block so that we can determine if
284 * compaction is viable.
286 if (slotstatus != FOUND) {
287 int size = ep->d_reclen;
290 size -= DIRSIZ(OFSFMT(vdp), ep);
292 if (size >= slotneeded) {
294 slotoffset = dp->i_offset;
295 slotsize = ep->d_reclen;
296 } else if (slotstatus == NONE) {
297 slotfreespace += size;
298 if (slotoffset == -1)
299 slotoffset = dp->i_offset;
300 if (slotfreespace >= slotneeded) {
301 slotstatus = COMPACT;
302 slotsize = dp->i_offset +
303 ep->d_reclen - slotoffset;
310 * Check for a name match.
313 # if (BYTE_ORDER == LITTLE_ENDIAN)
317 namlen = ep->d_namlen;
319 namlen = ep->d_namlen;
321 if (namlen == cnp->cn_namelen &&
322 (cnp->cn_nameptr[0] == ep->d_name[0]) &&
323 !bcmp(cnp->cn_nameptr, ep->d_name,
329 * Save directory entry's inode number and
330 * reclen in ndp->ni_ufs area, and release
333 if (vdp->v_mount->mnt_maxsymlinklen > 0 &&
334 ep->d_type == DT_WHT) {
336 slotoffset = dp->i_offset;
337 slotsize = ep->d_reclen;
338 dp->i_reclen = slotsize;
339 enduseful = dp->i_size;
340 ap->a_cnp->cn_flags |= CNP_ISWHITEOUT;
344 dp->i_ino = ep->d_ino;
345 dp->i_reclen = ep->d_reclen;
349 prevoff = dp->i_offset;
350 dp->i_offset += ep->d_reclen;
351 entryoffsetinblock += ep->d_reclen;
353 enduseful = dp->i_offset;
357 * If we started in the middle of the directory and failed
358 * to find our target, we must check the beginning as well.
360 if (numdirpasses == 2) {
363 endsearch = dp->i_diroff;
369 * If creating, and at end of pathname and current
370 * directory has not been removed, then can consider
371 * allowing file to be created.
373 if ((nameiop == NAMEI_CREATE || nameiop == NAMEI_RENAME ||
374 (nameiop == NAMEI_DELETE &&
375 (ap->a_cnp->cn_flags & CNP_DOWHITEOUT) &&
376 (ap->a_cnp->cn_flags & CNP_ISWHITEOUT))) &&
377 dp->i_effnlink != 0) {
379 * Access for write is interpreted as allowing
380 * creation of files in the directory.
382 error = VOP_EACCESS(vdp, VWRITE, cred);
386 * Return an indication of where the new directory
387 * entry should be put. If we didn't find a slot,
388 * then set dp->i_count to 0 indicating
389 * that the new slot belongs at the end of the
390 * directory. If we found a slot, then the new entry
391 * can be put in the range from dp->i_offset to
392 * dp->i_offset + dp->i_count.
394 if (slotstatus == NONE) {
395 dp->i_offset = roundup2(dp->i_size, DIRBLKSIZ);
397 enduseful = dp->i_offset;
398 } else if (nameiop == NAMEI_DELETE) {
399 dp->i_offset = slotoffset;
400 if ((dp->i_offset & (DIRBLKSIZ - 1)) == 0)
403 dp->i_count = dp->i_offset - prevoff;
405 dp->i_offset = slotoffset;
406 dp->i_count = slotsize;
407 if (enduseful < slotoffset + slotsize)
408 enduseful = slotoffset + slotsize;
410 dp->i_endoff = roundup2(enduseful, DIRBLKSIZ);
411 dp->i_flag |= IN_CHANGE | IN_UPDATE;
413 * We return with the directory locked, so that
414 * the parameters we set up above will still be
415 * valid if we actually decide to do a direnter().
416 * We return ni_vp == NULL to indicate that the entry
417 * does not currently exist; we leave a pointer to
418 * the (locked) directory inode in ndp->ni_dvp.
419 * The pathname buffer is saved so that the name
420 * can be obtained later.
422 * NB - if the directory is unlocked, then this
423 * information cannot be used.
427 cnp->cn_flags |= CNP_PDIRUNLOCK;
429 return (EJUSTRETURN);
435 * Check that directory length properly reflects presence
438 if (dp->i_offset + DIRSIZ(OFSFMT(vdp), ep) > dp->i_size) {
439 ufs_dirbad(dp, dp->i_offset, "i_size too small");
440 dp->i_size = dp->i_offset + DIRSIZ(OFSFMT(vdp), ep);
441 dp->i_flag |= IN_CHANGE | IN_UPDATE;
446 * Found component in pathname.
447 * If the final component of path name, save information
448 * in the cache as to where the entry was found.
450 if (nameiop == NAMEI_LOOKUP)
451 dp->i_diroff = dp->i_offset &~ (DIRBLKSIZ - 1);
454 * If deleting, and at end of pathname, return
455 * parameters which can be used to remove file.
456 * If the wantparent flag isn't set, we return only
457 * the directory (in ndp->ni_dvp), otherwise we go
458 * on and lock the inode, being careful with ".".
460 if (nameiop == NAMEI_DELETE) {
462 * Write access to directory required to delete files.
464 error = VOP_EACCESS(vdp, VWRITE, cred);
468 * Return pointer to current entry in dp->i_offset,
469 * and distance past previous entry (if there
470 * is a previous entry in this block) in dp->i_count.
471 * Save directory inode pointer in ndp->ni_dvp for dirremove().
473 if ((dp->i_offset & (DIRBLKSIZ - 1)) == 0)
476 dp->i_count = dp->i_offset - prevoff;
477 if (dp->i_number == dp->i_ino) {
482 if (flags & CNP_ISDOTDOT)
483 vn_unlock(vdp); /* race to get the inode */
484 error = VFS_VGET(vdp->v_mount, NULL, dp->i_ino, &tdp);
485 if (flags & CNP_ISDOTDOT) {
486 if (vn_lock(vdp, LK_EXCLUSIVE | LK_RETRY) != 0)
487 cnp->cn_flags |= CNP_PDIRUNLOCK;
492 * If directory is "sticky", then user must own
493 * the directory, or the file in it, else she
494 * may not delete it (unless she's root). This
495 * implements append-only directories.
497 if ((dp->i_mode & ISVTX) &&
499 cred->cr_uid != dp->i_uid &&
500 VTOI(tdp)->i_uid != cred->cr_uid) {
507 cnp->cn_flags |= CNP_PDIRUNLOCK;
513 * If rewriting (RENAME), return the inode and the
514 * information required to rewrite the present directory
515 * Must get inode of directory entry to verify it's a
516 * regular file, or empty directory.
518 if (nameiop == NAMEI_RENAME && wantparent) {
519 if ((error = VOP_EACCESS(vdp, VWRITE, cred)) != 0)
522 * Careful about locking second inode.
523 * This can only occur if the target is ".".
525 if (dp->i_number == dp->i_ino)
527 if (flags & CNP_ISDOTDOT)
528 vn_unlock(vdp); /* race to get the inode */
529 error = VFS_VGET(vdp->v_mount, NULL, dp->i_ino, &tdp);
530 if (flags & CNP_ISDOTDOT) {
531 if (vn_lock(vdp, LK_EXCLUSIVE | LK_RETRY) != 0)
532 cnp->cn_flags |= CNP_PDIRUNLOCK;
539 cnp->cn_flags |= CNP_PDIRUNLOCK;
545 * Step through the translation in the name. We do not `vput' the
546 * directory because we may need it again if a symbolic link
547 * is relative to the current directory. Instead we save it
548 * unlocked as "pdp". We must get the target inode before unlocking
549 * the directory to insure that the inode will not be removed
550 * before we get it. We prevent deadlock by always fetching
551 * inodes from the root, moving down the directory tree. Thus
552 * when following backward pointers ".." we must unlock the
553 * parent directory before getting the requested directory.
554 * There is a potential race condition here if both the current
555 * and parent directories are removed before the VFS_VGET for the
556 * inode associated with ".." returns. We hope that this occurs
557 * infrequently since we cannot avoid this race condition without
558 * implementing a sophisticated deadlock detection algorithm.
559 * Note also that this simple deadlock detection scheme will not
560 * work if the filesystem has any hard links other than ".."
561 * that point backwards in the directory structure.
564 if (flags & CNP_ISDOTDOT) {
565 vn_unlock(pdp); /* race to get the inode */
566 cnp->cn_flags |= CNP_PDIRUNLOCK;
567 error = VFS_VGET(vdp->v_mount, NULL, dp->i_ino, &tdp);
569 if (vn_lock(pdp, LK_EXCLUSIVE | LK_RETRY) == 0)
570 cnp->cn_flags &= ~CNP_PDIRUNLOCK;
574 if ((error = vn_lock(pdp, LK_EXCLUSIVE)) != 0) {
578 cnp->cn_flags &= ~CNP_PDIRUNLOCK;
581 } else if (dp->i_number == dp->i_ino) {
582 vref(vdp); /* we want ourself, ie "." */
585 error = VFS_VGET(vdp->v_mount, NULL, dp->i_ino, &tdp);
590 cnp->cn_flags |= CNP_PDIRUNLOCK;
598 ufs_dirbad(struct inode *ip, doff_t offset, char *how)
602 mp = ITOV(ip)->v_mount;
603 (void)kprintf("%s: bad dir ino %lu at offset %ld: %s\n",
604 mp->mnt_stat.f_mntfromname, (u_long)ip->i_number, (long)offset, how);
605 if ((mp->mnt_flag & MNT_RDONLY) == 0)
606 panic("ufs_dirbad: bad dir");
610 * Do consistency checking on a directory entry:
611 * record length must be multiple of 4
612 * entry must fit in rest of its DIRBLKSIZ block
613 * record must be large enough to contain entry
614 * name is not longer than MAXNAMLEN
615 * name must be as long as advertised, and null terminated
618 ufs_dirbadentry(struct vnode *dp, struct direct *ep, int entryoffsetinblock)
623 # if (BYTE_ORDER == LITTLE_ENDIAN)
627 namlen = ep->d_namlen;
629 namlen = ep->d_namlen;
631 if ((ep->d_reclen & 0x3) != 0 ||
632 ep->d_reclen > DIRBLKSIZ - (entryoffsetinblock & (DIRBLKSIZ - 1)) ||
633 ep->d_reclen < DIRSIZ(OFSFMT(dp), ep) || namlen > MAXNAMLEN) {
635 kprintf("First bad\n");
640 for (i = 0; i < namlen; i++)
641 if (ep->d_name[i] == '\0') {
643 kprintf("Second bad\n");
654 * Construct a new directory entry after a call to namei, using the
655 * parameters that it left in the componentname argument cnp. The
656 * argument ip is the inode to which the new directory entry will refer.
659 ufs_makedirentry(struct inode *ip, struct componentname *cnp,
660 struct direct *newdirp)
663 newdirp->d_ino = ip->i_number;
664 newdirp->d_namlen = cnp->cn_namelen;
665 bcopy(cnp->cn_nameptr, newdirp->d_name, (unsigned)cnp->cn_namelen + 1);
666 if (ITOV(ip)->v_mount->mnt_maxsymlinklen > 0)
667 newdirp->d_type = IFTODT(ip->i_mode);
670 # if (BYTE_ORDER == LITTLE_ENDIAN)
671 { u_char tmp = newdirp->d_namlen;
672 newdirp->d_namlen = newdirp->d_type;
673 newdirp->d_type = tmp; }
679 * Write a directory entry after a call to namei, using the parameters
680 * that it left in the directory inode. The argument dirp is the new directory
681 * entry contents. Dvp is a pointer to the directory to be written,
682 * which was left locked by namei. Remaining parameters (dp->i_offset,
683 * dp->i_count) indicate how the space for the new entry is to be obtained.
684 * Non-null bp indicates that a directory is being created (for the
685 * soft dependency code).
688 ufs_direnter(struct vnode *dvp, struct vnode *tvp, struct direct *dirp,
689 struct componentname *cnp, struct buf *newdirbp)
696 struct direct *ep, *nep;
697 int error, ret, blkoff, loc, spacefree, flags;
701 KKASSERT(cred != NULL);
704 newentrysize = DIRSIZ(OFSFMT(dvp), dirp);
706 if (dp->i_count == 0) {
708 * If dp->i_count is 0, then namei could find no
709 * space in the directory. Here, dp->i_offset will
710 * be on a directory block boundary and we will write the
711 * new entry into a fresh block.
713 if (dp->i_offset & (DIRBLKSIZ - 1))
714 panic("ufs_direnter: newblk");
715 nvnode_pager_setsize(dvp, dp->i_offset + DIRBLKSIZ,
718 if (!DOINGSOFTDEP(dvp) && !DOINGASYNC(dvp))
720 if ((error = VOP_BALLOC(dvp, (off_t)dp->i_offset, DIRBLKSIZ,
721 cred, flags, &bp)) != 0) {
722 if (DOINGSOFTDEP(dvp) && newdirbp != NULL)
726 dp->i_size = dp->i_offset + DIRBLKSIZ;
727 dp->i_flag |= IN_CHANGE | IN_UPDATE;
728 dirp->d_reclen = DIRBLKSIZ;
729 blkoff = dp->i_offset &
730 (VFSTOUFS(dvp->v_mount)->um_mountp->mnt_stat.f_iosize - 1);
731 bcopy((caddr_t)dirp, (caddr_t)bp->b_data + blkoff,newentrysize);
733 if (dp->i_dirhash != NULL) {
734 ufsdirhash_newblk(dp, dp->i_offset);
735 ufsdirhash_add(dp, dirp, dp->i_offset);
736 ufsdirhash_checkblock(dp, (char *)bp->b_data + blkoff,
740 if (DOINGSOFTDEP(dvp)) {
742 * Ensure that the entire newly allocated block is a
743 * valid directory so that future growth within the
744 * block does not have to ensure that the block is
745 * written before the inode.
748 while (blkoff < bp->b_bcount) {
750 (bp->b_data + blkoff))->d_reclen = DIRBLKSIZ;
753 softdep_setup_directory_add(bp, dp, dp->i_offset,
754 dirp->d_ino, newdirbp);
756 return (ffs_update(dvp, 0));
758 if (DOINGASYNC(dvp)) {
760 return (ffs_update(dvp, 0));
763 ret = ffs_update(dvp, 1);
770 * If dp->i_count is non-zero, then namei found space for the new
771 * entry in the range dp->i_offset to dp->i_offset + dp->i_count
772 * in the directory. To use this space, we may have to compact
773 * the entries located there, by copying them together towards the
774 * beginning of the block, leaving the free space in one usable
779 * Increase size of directory if entry eats into new space.
780 * This should never push the size past a new multiple of
783 * N.B. - THIS IS AN ARTIFACT OF 4.2 AND SHOULD NEVER HAPPEN.
785 if (dp->i_offset + dp->i_count > dp->i_size)
786 dp->i_size = dp->i_offset + dp->i_count;
788 * Get the block containing the space for the new directory entry.
790 error = ffs_blkatoff(dvp, (off_t)dp->i_offset, &dirbuf, &bp);
792 if (DOINGSOFTDEP(dvp) && newdirbp != NULL)
797 * Find space for the new entry. In the simple case, the entry at
798 * offset base will have the space. If it does not, then namei
799 * arranged that compacting the region dp->i_offset to
800 * dp->i_offset + dp->i_count would yield the space.
802 ep = (struct direct *)dirbuf;
803 dsize = ep->d_ino ? DIRSIZ(OFSFMT(dvp), ep) : 0;
804 spacefree = ep->d_reclen - dsize;
805 for (loc = ep->d_reclen; loc < dp->i_count; ) {
806 nep = (struct direct *)(dirbuf + loc);
808 /* Trim the existing slot (NB: dsize may be zero). */
809 ep->d_reclen = dsize;
810 ep = (struct direct *)((char *)ep + dsize);
812 /* Read nep->d_reclen now as the bcopy() may clobber it. */
813 loc += nep->d_reclen;
814 if (nep->d_ino == 0) {
816 * A mid-block unused entry. Such entries are
817 * never created by the kernel, but fsck_ffs
818 * can create them (and it doesn't fix them).
820 * Add up the free space, and initialise the
821 * relocated entry since we don't bcopy it.
823 spacefree += nep->d_reclen;
828 dsize = DIRSIZ(OFSFMT(dvp), nep);
829 spacefree += nep->d_reclen - dsize;
831 if (dp->i_dirhash != NULL)
832 ufsdirhash_move(dp, nep,
833 dp->i_offset + ((char *)nep - dirbuf),
834 dp->i_offset + ((char *)ep - dirbuf));
836 if (DOINGSOFTDEP(dvp))
837 softdep_change_directoryentry_offset(dp, dirbuf,
838 (caddr_t)nep, (caddr_t)ep, dsize);
840 bcopy((caddr_t)nep, (caddr_t)ep, dsize);
843 * Here, `ep' points to a directory entry containing `dsize' in-use
844 * bytes followed by `spacefree' unused bytes. If ep->d_ino == 0,
845 * then the entry is completely unused (dsize == 0). The value
846 * of ep->d_reclen is always indeterminate.
848 * Update the pointer fields in the previous entry (if any),
849 * copy in the new entry, and write out the block.
851 if (ep->d_ino == 0 ||
852 (ep->d_ino == WINO &&
853 bcmp(ep->d_name, dirp->d_name, dirp->d_namlen) == 0)) {
854 if (spacefree + dsize < newentrysize)
855 panic("ufs_direnter: compact1");
856 dirp->d_reclen = spacefree + dsize;
858 if (spacefree < newentrysize)
859 panic("ufs_direnter: compact2");
860 dirp->d_reclen = spacefree;
861 ep->d_reclen = dsize;
862 ep = (struct direct *)((char *)ep + dsize);
865 if (dp->i_dirhash != NULL && (ep->d_ino == 0 ||
866 dirp->d_reclen == spacefree))
867 ufsdirhash_add(dp, dirp, dp->i_offset + ((char *)ep - dirbuf));
869 bcopy((caddr_t)dirp, (caddr_t)ep, (uint)newentrysize);
871 if (dp->i_dirhash != NULL)
872 ufsdirhash_checkblock(dp, dirbuf -
873 (dp->i_offset & (DIRBLKSIZ - 1)),
874 dp->i_offset & ~(DIRBLKSIZ - 1));
877 if (DOINGSOFTDEP(dvp)) {
878 softdep_setup_directory_add(bp, dp,
879 dp->i_offset + (caddr_t)ep - dirbuf, dirp->d_ino, newdirbp);
882 if (DOINGASYNC(dvp)) {
889 dp->i_flag |= IN_CHANGE | IN_UPDATE;
891 * If all went well, and the directory can be shortened, proceed
892 * with the truncation. Note that we have to unlock the inode for
893 * the entry that we just entered, as the truncation may need to
894 * lock other inodes which can lead to deadlock if we also hold a
895 * lock on the newly entered node.
897 if (error == 0 && dp->i_endoff && dp->i_endoff < dp->i_size) {
901 if (dp->i_dirhash != NULL)
902 ufsdirhash_dirtrunc(dp, dp->i_endoff);
904 (void)ffs_truncate(dvp, (off_t)dp->i_endoff, IO_SYNC, cred);
906 vn_lock(tvp, LK_EXCLUSIVE | LK_RETRY);
912 * Remove a directory entry after a call to namei, using
913 * the parameters which it left in the directory inode. The entry
914 * dp->i_offset contains the offset into the directory of the
915 * entry to be eliminated. The dp->i_count field contains the
916 * size of the previous record in the directory. If this
917 * is 0, the first entry is being deleted, so we need only
918 * zero the inode number to mark the entry as free. If the
919 * entry is not the first in the directory, we must reclaim
920 * the space of the now empty record by adding the record size
921 * to the size of the previous entry.
924 ufs_dirremove(struct vnode *dvp, struct inode *ip, int flags, int isrmdir)
933 if (flags & CNP_DOWHITEOUT) {
935 * Whiteout entry: set d_ino to WINO.
938 ffs_blkatoff(dvp, (off_t)dp->i_offset, (char **)&ep, &bp)) != 0)
945 if ((error = ffs_blkatoff(dvp,
946 (off_t)(dp->i_offset - dp->i_count), (char **)&ep, &bp)) != 0)
950 * Remove the dirhash entry. This is complicated by the fact
951 * that `ep' is the previous entry when dp->i_count != 0.
953 if (dp->i_dirhash != NULL)
954 ufsdirhash_remove(dp, (dp->i_count == 0) ? ep :
955 (struct direct *)((char *)ep + ep->d_reclen), dp->i_offset);
957 if (dp->i_count == 0) {
959 * First entry in block: set d_ino to zero.
964 * Collapse new free space into previous entry.
966 ep->d_reclen += dp->i_reclen;
969 if (dp->i_dirhash != NULL)
970 ufsdirhash_checkblock(dp, (char *)ep -
971 ((dp->i_offset - dp->i_count) & (DIRBLKSIZ - 1)),
972 dp->i_offset & ~(DIRBLKSIZ - 1));
975 if (DOINGSOFTDEP(dvp)) {
978 softdep_change_linkcnt(ip);
979 softdep_setup_remove(bp, dp, ip, isrmdir);
981 if (softdep_slowdown(dvp)) {
991 ip->i_flag |= IN_CHANGE;
993 if (flags & CNP_DOWHITEOUT)
995 else if (DOINGASYNC(dvp) && dp->i_count != 0) {
1001 dp->i_flag |= IN_CHANGE | IN_UPDATE;
1006 * Rewrite an existing directory entry to point at the inode
1007 * supplied. The parameters describing the directory entry are
1008 * set up by a call to namei.
1011 ufs_dirrewrite(struct inode *dp, struct inode *oip, ino_t newinum, int newtype,
1016 struct vnode *vdp = ITOV(dp);
1019 error = ffs_blkatoff(vdp, (off_t)dp->i_offset, (char **)&ep, &bp);
1022 ep->d_ino = newinum;
1024 ep->d_type = newtype;
1026 if (DOINGSOFTDEP(vdp)) {
1027 softdep_change_linkcnt(oip);
1028 softdep_setup_directory_change(bp, dp, oip, newinum, isrmdir);
1032 oip->i_flag |= IN_CHANGE;
1033 if (DOINGASYNC(vdp)) {
1037 error = bowrite(bp);
1040 dp->i_flag |= IN_CHANGE | IN_UPDATE;
1045 * Check if a directory is empty or not.
1046 * Inode supplied must be locked.
1048 * Using a struct dirtemplate here is not precisely
1049 * what we want, but better than using a struct direct.
1051 * NB: does not handle corrupted directories.
1054 ufs_dirempty(struct inode *ip, ino_t parentino, struct ucred *cred)
1057 struct dirtemplate dbuf;
1058 struct direct *dp = (struct direct *)&dbuf;
1059 int error, count, namlen;
1060 #define MINDIRSIZ (sizeof (struct dirtemplate) / 2)
1062 for (off = 0; off < ip->i_size; off += dp->d_reclen) {
1063 error = vn_rdwr(UIO_READ, ITOV(ip), (caddr_t)dp, MINDIRSIZ, off,
1064 UIO_SYSSPACE, IO_NODELOCKED, cred, &count);
1066 * Since we read MINDIRSIZ, residual must
1067 * be 0 unless we're at end of file.
1069 if (error || count != 0)
1071 /* avoid infinite loops */
1072 if (dp->d_reclen == 0)
1074 /* skip empty entries */
1075 if (dp->d_ino == 0 || dp->d_ino == WINO)
1077 /* accept only "." and ".." */
1078 # if (BYTE_ORDER == LITTLE_ENDIAN)
1079 if (OFSFMT(ITOV(ip)))
1080 namlen = dp->d_type;
1082 namlen = dp->d_namlen;
1084 namlen = dp->d_namlen;
1088 if (dp->d_name[0] != '.')
1091 * At this point namlen must be 1 or 2.
1092 * 1 implies ".", 2 implies ".." if second
1095 if (namlen == 1 && dp->d_ino == ip->i_number)
1097 if (dp->d_name[1] == '.' && dp->d_ino == parentino)
1105 * Check if source directory is in the path of the target directory.
1106 * Target is supplied locked, source is unlocked.
1107 * The target is always vput before returning.
1110 ufs_checkpath(struct inode *source, struct inode *target, struct ucred *cred)
1113 int error, rootino, namlen;
1114 struct dirtemplate dirbuf;
1117 if (target->i_number == source->i_number) {
1123 if (target->i_number == rootino)
1127 if (vp->v_type != VDIR) {
1131 error = vn_rdwr(UIO_READ, vp, (caddr_t)&dirbuf,
1132 sizeof (struct dirtemplate), (off_t)0,
1133 UIO_SYSSPACE, IO_NODELOCKED, cred, NULL);
1136 # if (BYTE_ORDER == LITTLE_ENDIAN)
1138 namlen = dirbuf.dotdot_type;
1140 namlen = dirbuf.dotdot_namlen;
1142 namlen = dirbuf.dotdot_namlen;
1145 dirbuf.dotdot_name[0] != '.' ||
1146 dirbuf.dotdot_name[1] != '.') {
1150 if (dirbuf.dotdot_ino == source->i_number) {
1154 if (dirbuf.dotdot_ino == rootino)
1157 error = VFS_VGET(vp->v_mount, NULL, dirbuf.dotdot_ino, &vp);
1165 if (error == ENOTDIR)
1166 kprintf("checkpath: .. not a directory\n");