/* * Copyright (c) 1989, 1993 * The Regents of the University of California. All rights reserved. * (c) UNIX System Laboratories, Inc. * All or some portions of this file are derived from material licensed * to the University of California by American Telephone and Telegraph * Co. or Unix System Laboratories, Inc. and are reproduced herein with * the permission of UNIX System Laboratories, Inc. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)ufs_lookup.c 8.15 (Berkeley) 6/16/95 * $FreeBSD: src/sys/ufs/ufs/ufs_lookup.c,v 1.33.2.7 2001/09/22 19:22:13 iedowse Exp $ */ #include "opt_ufs.h" #include #include #include #include #include #include #include #include #include #include #include #include #include "quota.h" #include "inode.h" #include "dir.h" #ifdef UFS_DIRHASH #include "dirhash.h" #endif #include "ufsmount.h" #include "ufs_extern.h" #include "ffs_extern.h" #ifdef DIAGNOSTIC int dirchk = 1; #else int dirchk = 0; #endif SYSCTL_INT(_debug, OID_AUTO, dircheck, CTLFLAG_RW, &dirchk, 0, "Enable full validation checks of directory"); /* true if old FS format...*/ #define OFSFMT(vp) ((vp)->v_mount->mnt_maxsymlinklen <= 0) /* * Convert a component of a pathname into a pointer to a locked inode. * This is a very central and rather complicated routine. * If the filesystem is not maintained in a strict tree hierarchy, * this can result in a deadlock situation (see comments in code below). * * The cnp->cn_nameiop argument is LOOKUP, CREATE, RENAME, or DELETE depending * on whether the name is to be looked up, created, renamed, or deleted. * When CREATE, RENAME, or DELETE is specified, information usable in * creating, renaming, or deleting a directory entry may be calculated. * If flag has LOCKPARENT or'ed into it and the target of the pathname * exists, lookup returns both the target and its parent directory locked. * When creating or renaming and LOCKPARENT is specified, the target may * not be ".". When deleting and LOCKPARENT is specified, the target may * be "."., but the caller must check to ensure it does an vrele and vput * instead of two vputs. * * Overall outline of ufs_lookup: * * search for name in directory, to found or notfound * notfound: * if creating, return locked directory, leaving info on available slots * else return error * found: * if at end of path and deleting, return information to allow delete * if at end of path and rewriting (RENAME and LOCKPARENT), lock target * inode and return info to allow rewrite * if not at end, add name to cache; if at end and neither creating * nor deleting, add name to cache * * ufs_lookup(struct vnode *a_dvp, struct vnode **a_vpp, * struct componentname *a_cnp) */ int ufs_lookup(struct vop_old_lookup_args *ap) { struct vnode *vdp; /* vnode for directory being searched */ struct inode *dp; /* inode for directory being searched */ struct buf *bp; /* a buffer of directory entries */ struct direct *ep; /* the current directory entry */ int entryoffsetinblock; /* offset of ep in bp's buffer */ enum {NONE, COMPACT, FOUND} slotstatus; doff_t slotoffset; /* offset of area with free space */ int slotsize; /* size of area at slotoffset */ int slotfreespace; /* amount of space free in slot */ int slotneeded; /* size of the entry we're seeking */ int numdirpasses; /* strategy for directory search */ doff_t endsearch; /* offset to end directory search */ doff_t prevoff; /* prev entry dp->i_offset */ struct vnode *pdp; /* saved dp during symlink work */ struct vnode *tdp; /* returned by VFS_VGET */ doff_t enduseful; /* pointer past last used dir slot */ u_long bmask; /* block offset mask */ int lockparent; /* 1 => lockparent flag is set */ int wantparent; /* 1 => wantparent or lockparent flag */ int namlen, error; struct vnode **vpp = ap->a_vpp; struct componentname *cnp = ap->a_cnp; struct ucred *cred = cnp->cn_cred; int flags = cnp->cn_flags; int nameiop = cnp->cn_nameiop; bp = NULL; slotoffset = -1; cnp->cn_flags &= ~CNP_PDIRUNLOCK; /* * XXX there was a soft-update diff about this I couldn't merge. * I think this was the equiv. */ *vpp = NULL; vdp = ap->a_dvp; dp = VTOI(vdp); lockparent = flags & CNP_LOCKPARENT; wantparent = flags & (CNP_LOCKPARENT|CNP_WANTPARENT); /* * We now have a segment name to search for, and a directory to search. * * Suppress search for slots unless creating * file and at end of pathname, in which case * we watch for a place to put the new file in * case it doesn't already exist. */ slotstatus = FOUND; slotfreespace = slotsize = slotneeded = 0; if (nameiop == NAMEI_CREATE || nameiop == NAMEI_RENAME) { slotstatus = NONE; slotneeded = DIRECTSIZ(cnp->cn_namelen); } bmask = VFSTOUFS(vdp->v_mount)->um_mountp->mnt_stat.f_iosize - 1; #ifdef UFS_DIRHASH /* * Use dirhash for fast operations on large directories. The logic * to determine whether to hash the directory is contained within * ufsdirhash_build(); a zero return means that it decided to hash * this directory and it successfully built up the hash table. */ if (ufsdirhash_build(dp) == 0) { /* Look for a free slot if needed. */ enduseful = dp->i_size; if (slotstatus != FOUND) { slotoffset = ufsdirhash_findfree(dp, slotneeded, &slotsize); if (slotoffset >= 0) { slotstatus = COMPACT; enduseful = ufsdirhash_enduseful(dp); if (enduseful < 0) enduseful = dp->i_size; } } /* Look up the component. */ numdirpasses = 1; entryoffsetinblock = 0; /* silence compiler warning */ switch (ufsdirhash_lookup(dp, cnp->cn_nameptr, cnp->cn_namelen, &dp->i_offset, &bp, nameiop == NAMEI_DELETE ? &prevoff : NULL)) { case 0: ep = (struct direct *)((char *)bp->b_data + (dp->i_offset & bmask)); goto foundentry; case ENOENT: dp->i_offset = roundup2(dp->i_size, DIRBLKSIZ); goto notfound; default: /* Something failed; just do a linear search. */ break; } } #endif /* UFS_DIRHASH */ /* * If there is cached information on a previous search of * this directory, pick up where we last left off. * We cache only lookups as these are the most common * and have the greatest payoff. Caching CREATE has little * benefit as it usually must search the entire directory * to determine that the entry does not exist. Caching the * location of the last DELETE or RENAME has not reduced * profiling time and hence has been removed in the interest * of simplicity. */ if (nameiop != NAMEI_LOOKUP || dp->i_diroff == 0 || dp->i_diroff >= dp->i_size) { entryoffsetinblock = 0; dp->i_offset = 0; numdirpasses = 1; } else { dp->i_offset = dp->i_diroff; if ((entryoffsetinblock = dp->i_offset & bmask) && (error = ffs_blkatoff(vdp, (off_t)dp->i_offset, NULL, &bp))) return (error); numdirpasses = 2; } prevoff = dp->i_offset; endsearch = roundup2(dp->i_size, DIRBLKSIZ); enduseful = 0; searchloop: while (dp->i_offset < endsearch) { /* * If necessary, get the next directory block. */ if ((dp->i_offset & bmask) == 0) { if (bp != NULL) brelse(bp); error = ffs_blkatoff(vdp, (off_t)dp->i_offset, NULL, &bp); if (error) return (error); entryoffsetinblock = 0; } /* * If still looking for a slot, and at a DIRBLKSIZE * boundary, have to start looking for free space again. */ if (slotstatus == NONE && (entryoffsetinblock & (DIRBLKSIZ - 1)) == 0) { slotoffset = -1; slotfreespace = 0; } /* * Get pointer to next entry. * Full validation checks are slow, so we only check * enough to insure forward progress through the * directory. Complete checks can be run by patching * "dirchk" to be true. */ ep = (struct direct *)((char *)bp->b_data + entryoffsetinblock); if (ep->d_reclen == 0 || ep->d_reclen > DIRBLKSIZ - (entryoffsetinblock & (DIRBLKSIZ - 1)) || (dirchk && ufs_dirbadentry(vdp, ep, entryoffsetinblock))) { int i; ufs_dirbad(dp, dp->i_offset, "mangled entry"); i = DIRBLKSIZ - (entryoffsetinblock & (DIRBLKSIZ - 1)); dp->i_offset += i; entryoffsetinblock += i; continue; } /* * If an appropriate sized slot has not yet been found, * check to see if one is available. Also accumulate space * in the current block so that we can determine if * compaction is viable. */ if (slotstatus != FOUND) { int size = ep->d_reclen; if (ep->d_ino != 0) size -= DIRSIZ(OFSFMT(vdp), ep); if (size > 0) { if (size >= slotneeded) { slotstatus = FOUND; slotoffset = dp->i_offset; slotsize = ep->d_reclen; } else if (slotstatus == NONE) { slotfreespace += size; if (slotoffset == -1) slotoffset = dp->i_offset; if (slotfreespace >= slotneeded) { slotstatus = COMPACT; slotsize = dp->i_offset + ep->d_reclen - slotoffset; } } } } /* * Check for a name match. */ if (ep->d_ino) { # if (BYTE_ORDER == LITTLE_ENDIAN) if (OFSFMT(vdp)) namlen = ep->d_type; else namlen = ep->d_namlen; # else namlen = ep->d_namlen; # endif if (namlen == cnp->cn_namelen && (cnp->cn_nameptr[0] == ep->d_name[0]) && !bcmp(cnp->cn_nameptr, ep->d_name, (unsigned)namlen)) { #ifdef UFS_DIRHASH foundentry: #endif /* * Save directory entry's inode number and * reclen in ndp->ni_ufs area, and release * directory buffer. */ if (vdp->v_mount->mnt_maxsymlinklen > 0 && ep->d_type == DT_WHT) { slotstatus = FOUND; slotoffset = dp->i_offset; slotsize = ep->d_reclen; dp->i_reclen = slotsize; enduseful = dp->i_size; ap->a_cnp->cn_flags |= CNP_ISWHITEOUT; numdirpasses--; goto notfound; } dp->i_ino = ep->d_ino; dp->i_reclen = ep->d_reclen; goto found; } } prevoff = dp->i_offset; dp->i_offset += ep->d_reclen; entryoffsetinblock += ep->d_reclen; if (ep->d_ino) enduseful = dp->i_offset; } notfound: /* * If we started in the middle of the directory and failed * to find our target, we must check the beginning as well. */ if (numdirpasses == 2) { numdirpasses--; dp->i_offset = 0; endsearch = dp->i_diroff; goto searchloop; } if (bp != NULL) brelse(bp); /* * If creating, and at end of pathname and current * directory has not been removed, then can consider * allowing file to be created. */ if ((nameiop == NAMEI_CREATE || nameiop == NAMEI_RENAME || (nameiop == NAMEI_DELETE && (ap->a_cnp->cn_flags & CNP_DOWHITEOUT) && (ap->a_cnp->cn_flags & CNP_ISWHITEOUT))) && dp->i_effnlink != 0) { /* * Access for write is interpreted as allowing * creation of files in the directory. */ error = VOP_EACCESS(vdp, VWRITE, cred); if (error) return (error); /* * Return an indication of where the new directory * entry should be put. If we didn't find a slot, * then set dp->i_count to 0 indicating * that the new slot belongs at the end of the * directory. If we found a slot, then the new entry * can be put in the range from dp->i_offset to * dp->i_offset + dp->i_count. */ if (slotstatus == NONE) { dp->i_offset = roundup2(dp->i_size, DIRBLKSIZ); dp->i_count = 0; enduseful = dp->i_offset; } else if (nameiop == NAMEI_DELETE) { dp->i_offset = slotoffset; if ((dp->i_offset & (DIRBLKSIZ - 1)) == 0) dp->i_count = 0; else dp->i_count = dp->i_offset - prevoff; } else { dp->i_offset = slotoffset; dp->i_count = slotsize; if (enduseful < slotoffset + slotsize) enduseful = slotoffset + slotsize; } dp->i_endoff = roundup2(enduseful, DIRBLKSIZ); dp->i_flag |= IN_CHANGE | IN_UPDATE; /* * We return with the directory locked, so that * the parameters we set up above will still be * valid if we actually decide to do a direnter(). * We return ni_vp == NULL to indicate that the entry * does not currently exist; we leave a pointer to * the (locked) directory inode in ndp->ni_dvp. * The pathname buffer is saved so that the name * can be obtained later. * * NB - if the directory is unlocked, then this * information cannot be used. */ if (!lockparent) { vn_unlock(vdp); cnp->cn_flags |= CNP_PDIRUNLOCK; } return (EJUSTRETURN); } return (ENOENT); found: /* * Check that directory length properly reflects presence * of this entry. */ if (dp->i_offset + DIRSIZ(OFSFMT(vdp), ep) > dp->i_size) { ufs_dirbad(dp, dp->i_offset, "i_size too small"); dp->i_size = dp->i_offset + DIRSIZ(OFSFMT(vdp), ep); dp->i_flag |= IN_CHANGE | IN_UPDATE; } brelse(bp); /* * Found component in pathname. * If the final component of path name, save information * in the cache as to where the entry was found. */ if (nameiop == NAMEI_LOOKUP) dp->i_diroff = rounddown2(dp->i_offset, DIRBLKSIZ); /* * If deleting, and at end of pathname, return * parameters which can be used to remove file. * If the wantparent flag isn't set, we return only * the directory (in ndp->ni_dvp), otherwise we go * on and lock the inode, being careful with ".". */ if (nameiop == NAMEI_DELETE) { /* * Write access to directory required to delete files. */ error = VOP_EACCESS(vdp, VWRITE, cred); if (error) return (error); /* * Return pointer to current entry in dp->i_offset, * and distance past previous entry (if there * is a previous entry in this block) in dp->i_count. * Save directory inode pointer in ndp->ni_dvp for dirremove(). */ if ((dp->i_offset & (DIRBLKSIZ - 1)) == 0) dp->i_count = 0; else dp->i_count = dp->i_offset - prevoff; if (dp->i_number == dp->i_ino) { vref(vdp); *vpp = vdp; return (0); } if (flags & CNP_ISDOTDOT) vn_unlock(vdp); /* race to get the inode */ error = VFS_VGET(vdp->v_mount, NULL, dp->i_ino, &tdp); if (flags & CNP_ISDOTDOT) { if (vn_lock(vdp, LK_EXCLUSIVE | LK_RETRY | LK_FAILRECLAIM) != 0) { cnp->cn_flags |= CNP_PDIRUNLOCK; } } if (error) return (error); /* * If directory is "sticky", then user must own * the directory, or the file in it, else she * may not delete it (unless she's root). This * implements append-only directories. */ if ((dp->i_mode & ISVTX) && cred->cr_uid != 0 && cred->cr_uid != dp->i_uid && VTOI(tdp)->i_uid != cred->cr_uid) { vput(tdp); return (EPERM); } *vpp = tdp; if (!lockparent) { vn_unlock(vdp); cnp->cn_flags |= CNP_PDIRUNLOCK; } return (0); } /* * If rewriting (RENAME), return the inode and the * information required to rewrite the present directory * Must get inode of directory entry to verify it's a * regular file, or empty directory. */ if (nameiop == NAMEI_RENAME && wantparent) { if ((error = VOP_EACCESS(vdp, VWRITE, cred)) != 0) return (error); /* * Careful about locking second inode. * This can only occur if the target is ".". */ if (dp->i_number == dp->i_ino) return (EISDIR); if (flags & CNP_ISDOTDOT) vn_unlock(vdp); /* race to get the inode */ error = VFS_VGET(vdp->v_mount, NULL, dp->i_ino, &tdp); if (flags & CNP_ISDOTDOT) { if (vn_lock(vdp, LK_EXCLUSIVE | LK_RETRY | LK_FAILRECLAIM) != 0) { cnp->cn_flags |= CNP_PDIRUNLOCK; } } if (error) return (error); *vpp = tdp; if (!lockparent) { vn_unlock(vdp); cnp->cn_flags |= CNP_PDIRUNLOCK; } return (0); } /* * Step through the translation in the name. We do not `vput' the * directory because we may need it again if a symbolic link * is relative to the current directory. Instead we save it * unlocked as "pdp". We must get the target inode before unlocking * the directory to insure that the inode will not be removed * before we get it. We prevent deadlock by always fetching * inodes from the root, moving down the directory tree. Thus * when following backward pointers ".." we must unlock the * parent directory before getting the requested directory. * There is a potential race condition here if both the current * and parent directories are removed before the VFS_VGET for the * inode associated with ".." returns. We hope that this occurs * infrequently since we cannot avoid this race condition without * implementing a sophisticated deadlock detection algorithm. * Note also that this simple deadlock detection scheme will not * work if the filesystem has any hard links other than ".." * that point backwards in the directory structure. */ pdp = vdp; if (flags & CNP_ISDOTDOT) { vn_unlock(pdp); /* race to get the inode */ cnp->cn_flags |= CNP_PDIRUNLOCK; error = VFS_VGET(vdp->v_mount, NULL, dp->i_ino, &tdp); if (error) { if (vn_lock(pdp, LK_EXCLUSIVE | LK_RETRY | LK_FAILRECLAIM) == 0) { cnp->cn_flags &= ~CNP_PDIRUNLOCK; } return (error); } if (lockparent) { error = vn_lock(pdp, LK_EXCLUSIVE | LK_FAILRECLAIM); if (error) { vput(tdp); return (error); } cnp->cn_flags &= ~CNP_PDIRUNLOCK; } *vpp = tdp; } else if (dp->i_number == dp->i_ino) { vref(vdp); /* we want ourself, ie "." */ *vpp = vdp; } else { error = VFS_VGET(vdp->v_mount, NULL, dp->i_ino, &tdp); if (error) return (error); if (!lockparent) { vn_unlock(pdp); cnp->cn_flags |= CNP_PDIRUNLOCK; } *vpp = tdp; } return (0); } void ufs_dirbad(struct inode *ip, doff_t offset, char *how) { struct mount *mp; mp = ITOV(ip)->v_mount; (void)kprintf("%s: bad dir ino %lu at offset %ld: %s\n", mp->mnt_stat.f_mntfromname, (u_long)ip->i_number, (long)offset, how); if ((mp->mnt_flag & MNT_RDONLY) == 0) panic("ufs_dirbad: bad dir"); } /* * Do consistency checking on a directory entry: * record length must be multiple of 4 * entry must fit in rest of its DIRBLKSIZ block * record must be large enough to contain entry * name is not longer than MAXNAMLEN * name must be as long as advertised, and null terminated */ int ufs_dirbadentry(struct vnode *dp, struct direct *ep, int entryoffsetinblock) { int i; int namlen; # if (BYTE_ORDER == LITTLE_ENDIAN) if (OFSFMT(dp)) namlen = ep->d_type; else namlen = ep->d_namlen; # else namlen = ep->d_namlen; # endif if ((ep->d_reclen & 0x3) != 0 || ep->d_reclen > DIRBLKSIZ - (entryoffsetinblock & (DIRBLKSIZ - 1)) || ep->d_reclen < DIRSIZ(OFSFMT(dp), ep) || namlen > MAXNAMLEN) { /*return (1); */ kprintf("First bad\n"); goto bad; } if (ep->d_ino == 0) return (0); for (i = 0; i < namlen; i++) if (ep->d_name[i] == '\0') { /*return (1); */ kprintf("Second bad\n"); goto bad; } if (ep->d_name[i]) goto bad; return (0); bad: return (1); } /* * Construct a new directory entry after a call to namei, using the * parameters that it left in the componentname argument cnp. The * argument ip is the inode to which the new directory entry will refer. */ void ufs_makedirentry(struct inode *ip, struct componentname *cnp, struct direct *newdirp) { newdirp->d_ino = ip->i_number; newdirp->d_namlen = cnp->cn_namelen; bcopy(cnp->cn_nameptr, newdirp->d_name, (unsigned)cnp->cn_namelen + 1); if (ITOV(ip)->v_mount->mnt_maxsymlinklen > 0) newdirp->d_type = IFTODT(ip->i_mode); else { newdirp->d_type = 0; # if (BYTE_ORDER == LITTLE_ENDIAN) { u_char tmp = newdirp->d_namlen; newdirp->d_namlen = newdirp->d_type; newdirp->d_type = tmp; } # endif } } /* * Write a directory entry after a call to namei, using the parameters * that it left in the directory inode. The argument dirp is the new directory * entry contents. Dvp is a pointer to the directory to be written, * which was left locked by namei. Remaining parameters (dp->i_offset, * dp->i_count) indicate how the space for the new entry is to be obtained. * Non-null bp indicates that a directory is being created (for the * soft dependency code). */ int ufs_direnter(struct vnode *dvp, struct vnode *tvp, struct direct *dirp, struct componentname *cnp, struct buf *newdirbp) { struct ucred *cred; int newentrysize; struct inode *dp; struct buf *bp; uint dsize; struct direct *ep, *nep; int error, ret, blkoff, loc, spacefree, flags; char *dirbuf; cred = cnp->cn_cred; KKASSERT(cred != NULL); dp = VTOI(dvp); newentrysize = DIRSIZ(OFSFMT(dvp), dirp); if (dp->i_count == 0) { /* * If dp->i_count is 0, then namei could find no * space in the directory. Here, dp->i_offset will * be on a directory block boundary and we will write the * new entry into a fresh block. */ if (dp->i_offset & (DIRBLKSIZ - 1)) panic("ufs_direnter: newblk"); nvnode_pager_setsize(dvp, dp->i_offset + DIRBLKSIZ, DIRBLKSIZ, -1); flags = B_CLRBUF; if (!DOINGSOFTDEP(dvp) && !DOINGASYNC(dvp)) flags |= B_SYNC; if ((error = VOP_BALLOC(dvp, (off_t)dp->i_offset, DIRBLKSIZ, cred, flags, &bp)) != 0) { if (DOINGSOFTDEP(dvp) && newdirbp != NULL) bdwrite(newdirbp); return (error); } dp->i_size = dp->i_offset + DIRBLKSIZ; dp->i_flag |= IN_CHANGE | IN_UPDATE; dirp->d_reclen = DIRBLKSIZ; blkoff = dp->i_offset & (VFSTOUFS(dvp->v_mount)->um_mountp->mnt_stat.f_iosize - 1); bcopy((caddr_t)dirp, (caddr_t)bp->b_data + blkoff,newentrysize); #ifdef UFS_DIRHASH if (dp->i_dirhash != NULL) { ufsdirhash_newblk(dp, dp->i_offset); ufsdirhash_add(dp, dirp, dp->i_offset); ufsdirhash_checkblock(dp, (char *)bp->b_data + blkoff, dp->i_offset); } #endif if (DOINGSOFTDEP(dvp)) { /* * Ensure that the entire newly allocated block is a * valid directory so that future growth within the * block does not have to ensure that the block is * written before the inode. */ blkoff += DIRBLKSIZ; while (blkoff < bp->b_bcount) { ((struct direct *) (bp->b_data + blkoff))->d_reclen = DIRBLKSIZ; blkoff += DIRBLKSIZ; } softdep_setup_directory_add(bp, dp, dp->i_offset, dirp->d_ino, newdirbp); bdwrite(bp); return (ffs_update(dvp, 0)); } if (DOINGASYNC(dvp)) { bdwrite(bp); return (ffs_update(dvp, 0)); } error = bwrite(bp); ret = ffs_update(dvp, 1); if (error == 0) return (ret); return (error); } /* * If dp->i_count is non-zero, then namei found space for the new * entry in the range dp->i_offset to dp->i_offset + dp->i_count * in the directory. To use this space, we may have to compact * the entries located there, by copying them together towards the * beginning of the block, leaving the free space in one usable * chunk at the end. */ /* * Increase size of directory if entry eats into new space. * This should never push the size past a new multiple of * DIRBLKSIZE. * * N.B. - THIS IS AN ARTIFACT OF 4.2 AND SHOULD NEVER HAPPEN. */ if (dp->i_offset + dp->i_count > dp->i_size) dp->i_size = dp->i_offset + dp->i_count; /* * Get the block containing the space for the new directory entry. */ error = ffs_blkatoff(dvp, (off_t)dp->i_offset, &dirbuf, &bp); if (error) { if (DOINGSOFTDEP(dvp) && newdirbp != NULL) bdwrite(newdirbp); return (error); } /* * Find space for the new entry. In the simple case, the entry at * offset base will have the space. If it does not, then namei * arranged that compacting the region dp->i_offset to * dp->i_offset + dp->i_count would yield the space. */ ep = (struct direct *)dirbuf; dsize = ep->d_ino ? DIRSIZ(OFSFMT(dvp), ep) : 0; spacefree = ep->d_reclen - dsize; for (loc = ep->d_reclen; loc < dp->i_count; ) { nep = (struct direct *)(dirbuf + loc); /* Trim the existing slot (NB: dsize may be zero). */ ep->d_reclen = dsize; ep = (struct direct *)((char *)ep + dsize); /* Read nep->d_reclen now as the bcopy() may clobber it. */ loc += nep->d_reclen; if (nep->d_ino == 0) { /* * A mid-block unused entry. Such entries are * never created by the kernel, but fsck_ffs * can create them (and it doesn't fix them). * * Add up the free space, and initialise the * relocated entry since we don't bcopy it. */ spacefree += nep->d_reclen; ep->d_ino = 0; dsize = 0; continue; } dsize = DIRSIZ(OFSFMT(dvp), nep); spacefree += nep->d_reclen - dsize; #ifdef UFS_DIRHASH if (dp->i_dirhash != NULL) ufsdirhash_move(dp, nep, dp->i_offset + ((char *)nep - dirbuf), dp->i_offset + ((char *)ep - dirbuf)); #endif if (DOINGSOFTDEP(dvp)) softdep_change_directoryentry_offset(dp, dirbuf, (caddr_t)nep, (caddr_t)ep, dsize); else bcopy((caddr_t)nep, (caddr_t)ep, dsize); } /* * Here, `ep' points to a directory entry containing `dsize' in-use * bytes followed by `spacefree' unused bytes. If ep->d_ino == 0, * then the entry is completely unused (dsize == 0). The value * of ep->d_reclen is always indeterminate. * * Update the pointer fields in the previous entry (if any), * copy in the new entry, and write out the block. */ if (ep->d_ino == 0 || (ep->d_ino == UFS_WINO && bcmp(ep->d_name, dirp->d_name, dirp->d_namlen) == 0)) { if (spacefree + dsize < newentrysize) panic("ufs_direnter: compact1"); dirp->d_reclen = spacefree + dsize; } else { if (spacefree < newentrysize) panic("ufs_direnter: compact2"); dirp->d_reclen = spacefree; ep->d_reclen = dsize; ep = (struct direct *)((char *)ep + dsize); } #ifdef UFS_DIRHASH if (dp->i_dirhash != NULL && (ep->d_ino == 0 || dirp->d_reclen == spacefree)) ufsdirhash_add(dp, dirp, dp->i_offset + ((char *)ep - dirbuf)); #endif bcopy((caddr_t)dirp, (caddr_t)ep, (uint)newentrysize); #ifdef UFS_DIRHASH if (dp->i_dirhash != NULL) ufsdirhash_checkblock(dp, dirbuf - (dp->i_offset & (DIRBLKSIZ - 1)), rounddown2(dp->i_offset, DIRBLKSIZ)); #endif if (DOINGSOFTDEP(dvp)) { softdep_setup_directory_add(bp, dp, dp->i_offset + (caddr_t)ep - dirbuf, dirp->d_ino, newdirbp); bdwrite(bp); } else { if (DOINGASYNC(dvp)) { bdwrite(bp); error = 0; } else { error = bwrite(bp); } } dp->i_flag |= IN_CHANGE | IN_UPDATE; /* * If all went well, and the directory can be shortened, proceed * with the truncation. Note that we have to unlock the inode for * the entry that we just entered, as the truncation may need to * lock other inodes which can lead to deadlock if we also hold a * lock on the newly entered node. */ if (error == 0 && dp->i_endoff && dp->i_endoff < dp->i_size) { if (tvp != NULL) vn_unlock(tvp); #ifdef UFS_DIRHASH if (dp->i_dirhash != NULL) ufsdirhash_dirtrunc(dp, dp->i_endoff); #endif (void)ffs_truncate(dvp, (off_t)dp->i_endoff, IO_SYNC, cred); if (tvp != NULL) vn_lock(tvp, LK_EXCLUSIVE | LK_RETRY); } return (error); } /* * Remove a directory entry after a call to namei, using * the parameters which it left in the directory inode. The entry * dp->i_offset contains the offset into the directory of the * entry to be eliminated. The dp->i_count field contains the * size of the previous record in the directory. If this * is 0, the first entry is being deleted, so we need only * zero the inode number to mark the entry as free. If the * entry is not the first in the directory, we must reclaim * the space of the now empty record by adding the record size * to the size of the previous entry. */ int ufs_dirremove(struct vnode *dvp, struct inode *ip, int flags, int isrmdir) { struct inode *dp; struct direct *ep; struct buf *bp; int error; dp = VTOI(dvp); if (flags & CNP_DOWHITEOUT) { /* * Whiteout entry: set d_ino to UFS_WINO. */ if ((error = ffs_blkatoff(dvp, (off_t)dp->i_offset, (char **)&ep, &bp)) != 0) return (error); ep->d_ino = UFS_WINO; ep->d_type = DT_WHT; goto out; } if ((error = ffs_blkatoff(dvp, (off_t)(dp->i_offset - dp->i_count), (char **)&ep, &bp)) != 0) return (error); #ifdef UFS_DIRHASH /* * Remove the dirhash entry. This is complicated by the fact * that `ep' is the previous entry when dp->i_count != 0. */ if (dp->i_dirhash != NULL) ufsdirhash_remove(dp, (dp->i_count == 0) ? ep : (struct direct *)((char *)ep + ep->d_reclen), dp->i_offset); #endif if (dp->i_count == 0) { /* * First entry in block: set d_ino to zero. */ ep->d_ino = 0; } else { /* * Collapse new free space into previous entry. */ ep->d_reclen += dp->i_reclen; } #ifdef UFS_DIRHASH if (dp->i_dirhash != NULL) ufsdirhash_checkblock(dp, (char *)ep - ((dp->i_offset - dp->i_count) & (DIRBLKSIZ - 1)), rounddown2(dp->i_offset, DIRBLKSIZ)); #endif out: if (DOINGSOFTDEP(dvp)) { if (ip) { ip->i_effnlink--; softdep_change_linkcnt(ip); softdep_setup_remove(bp, dp, ip, isrmdir); } if (softdep_slowdown(dvp)) { error = bwrite(bp); } else { bdwrite(bp); error = 0; } } else { if (ip) { ip->i_effnlink--; ip->i_nlink--; ip->i_flag |= IN_CHANGE; } if (flags & CNP_DOWHITEOUT) error = bwrite(bp); else if (DOINGASYNC(dvp) && dp->i_count != 0) { bdwrite(bp); error = 0; } else { error = bwrite(bp); } } dp->i_flag |= IN_CHANGE | IN_UPDATE; return (error); } /* * Rewrite an existing directory entry to point at the inode * supplied. The parameters describing the directory entry are * set up by a call to namei. */ int ufs_dirrewrite(struct inode *dp, struct inode *oip, ino_t newinum, int newtype, int isrmdir) { struct buf *bp; struct direct *ep; struct vnode *vdp = ITOV(dp); int error; error = ffs_blkatoff(vdp, (off_t)dp->i_offset, (char **)&ep, &bp); if (error) return (error); ep->d_ino = newinum; if (!OFSFMT(vdp)) ep->d_type = newtype; oip->i_effnlink--; if (DOINGSOFTDEP(vdp)) { softdep_change_linkcnt(oip); softdep_setup_directory_change(bp, dp, oip, newinum, isrmdir); bdwrite(bp); } else { oip->i_nlink--; oip->i_flag |= IN_CHANGE; if (DOINGASYNC(vdp)) { bdwrite(bp); error = 0; } else { error = bwrite(bp); } } dp->i_flag |= IN_CHANGE | IN_UPDATE; return (error); } /* * Check if a directory is empty or not. * Inode supplied must be locked. * * Using a struct dirtemplate here is not precisely * what we want, but better than using a struct direct. * * NB: does not handle corrupted directories. */ int ufs_dirempty(struct inode *ip, ino_t parentino, struct ucred *cred) { off_t off; struct dirtemplate dbuf; struct direct *dp = (struct direct *)&dbuf; int error, count, namlen; #define MINDIRSIZ (sizeof (struct dirtemplate) / 2) for (off = 0; off < ip->i_size; off += dp->d_reclen) { error = vn_rdwr(UIO_READ, ITOV(ip), (caddr_t)dp, MINDIRSIZ, off, UIO_SYSSPACE, IO_NODELOCKED, cred, &count); /* * Since we read MINDIRSIZ, residual must * be 0 unless we're at end of file. */ if (error || count != 0) return (0); /* avoid infinite loops */ if (dp->d_reclen == 0) return (0); /* skip empty entries */ if (dp->d_ino == 0 || dp->d_ino == UFS_WINO) continue; /* accept only "." and ".." */ # if (BYTE_ORDER == LITTLE_ENDIAN) if (OFSFMT(ITOV(ip))) namlen = dp->d_type; else namlen = dp->d_namlen; # else namlen = dp->d_namlen; # endif if (namlen > 2) return (0); if (dp->d_name[0] != '.') return (0); /* * At this point namlen must be 1 or 2. * 1 implies ".", 2 implies ".." if second * char is also "." */ if (namlen == 1 && dp->d_ino == ip->i_number) continue; if (dp->d_name[1] == '.' && dp->d_ino == parentino) continue; return (0); } return (1); } /* * Check if source directory is in the path of the target directory. * Target is supplied locked, source is unlocked. * The target is always vput before returning. */ int ufs_checkpath(struct inode *source, struct inode *target, struct ucred *cred) { struct vnode *vp; int error, rootino, namlen; struct dirtemplate dirbuf; vp = ITOV(target); if (target->i_number == source->i_number) { error = EEXIST; goto out; } rootino = UFS_ROOTINO; error = 0; if (target->i_number == rootino) goto out; for (;;) { if (vp->v_type != VDIR) { error = ENOTDIR; break; } error = vn_rdwr(UIO_READ, vp, (caddr_t)&dirbuf, sizeof (struct dirtemplate), (off_t)0, UIO_SYSSPACE, IO_NODELOCKED, cred, NULL); if (error != 0) break; # if (BYTE_ORDER == LITTLE_ENDIAN) if (OFSFMT(vp)) namlen = dirbuf.dotdot_type; else namlen = dirbuf.dotdot_namlen; # else namlen = dirbuf.dotdot_namlen; # endif if (namlen != 2 || dirbuf.dotdot_name[0] != '.' || dirbuf.dotdot_name[1] != '.') { error = ENOTDIR; break; } if (dirbuf.dotdot_ino == source->i_number) { error = EINVAL; break; } if (dirbuf.dotdot_ino == rootino) break; vput(vp); error = VFS_VGET(vp->v_mount, NULL, dirbuf.dotdot_ino, &vp); if (error) { vp = NULL; break; } } out: if (error == ENOTDIR) kprintf("checkpath: .. not a directory\n"); if (vp != NULL) vput(vp); return (error); }