/*- * 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. * 4. 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 */ #include __FBSDID("$FreeBSD$"); #include "opt_ufs.h" #include "opt_quota.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef UFS_DIRHASH #include #endif #include #include #ifdef DIAGNOSTIC static int dirchk = 1; #else static int dirchk = 0; #endif SYSCTL_INT(_debug, OID_AUTO, dircheck, CTLFLAG_RW, &dirchk, 0, ""); /* true if old FS format...*/ #define OFSFMT(vp) ((vp)->v_mount->mnt_maxsymlinklen <= 0) #ifdef QUOTA static int ufs_lookup_upgrade_lock(struct vnode *vp) { int error; ASSERT_VOP_LOCKED(vp, __FUNCTION__); if (VOP_ISLOCKED(vp) == LK_EXCLUSIVE) return (0); error = 0; /* * Upgrade vnode lock, since getinoquota() * requires exclusive lock to modify inode. */ vhold(vp); vn_lock(vp, LK_UPGRADE | LK_RETRY); VI_LOCK(vp); if (vp->v_iflag & VI_DOOMED) error = ENOENT; vdropl(vp); return (error); } #endif static int ufs_delete_denied(struct vnode *vdp, struct vnode *tdp, struct ucred *cred, struct thread *td) { int error; #ifdef UFS_ACL /* * NFSv4 Minor Version 1, draft-ietf-nfsv4-minorversion1-03.txt * * 3.16.2.1. ACE4_DELETE vs. ACE4_DELETE_CHILD */ /* * XXX: Is this check required? */ error = VOP_ACCESS(vdp, VEXEC, cred, td); if (error) return (error); error = VOP_ACCESSX(tdp, VDELETE, cred, td); if (error == 0) return (0); error = VOP_ACCESSX(vdp, VDELETE_CHILD, cred, td); if (error == 0) return (0); error = VOP_ACCESSX(vdp, VEXPLICIT_DENY | VDELETE_CHILD, cred, td); if (error) return (error); #endif /* !UFS_ACL */ /* * Standard Unix access control - delete access requires VWRITE. */ error = VOP_ACCESS(vdp, VWRITE, cred, td); 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 ((VTOI(vdp)->i_mode & ISVTX) && VOP_ACCESS(vdp, VADMIN, cred, td) && VOP_ACCESS(tdp, VADMIN, cred, td)) return (EPERM); return (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. * * This routine is actually used as VOP_CACHEDLOOKUP method, and the * filesystem employs the generic vfs_cache_lookup() as VOP_LOOKUP * method. * * vfs_cache_lookup() performs the following for us: * check that it is a directory * check accessibility of directory * check for modification attempts on read-only mounts * if name found in cache * if at end of path and deleting or creating * drop it * else * return name. * return VOP_CACHEDLOOKUP() * * 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 */ int ufs_lookup(ap) struct vop_cachedlookup_args /* { struct vnode *a_dvp; struct vnode **a_vpp; struct componentname *a_cnp; } */ *ap; { return (ufs_lookup_ino(ap->a_dvp, ap->a_vpp, ap->a_cnp, NULL)); } int ufs_lookup_ino(struct vnode *vdp, struct vnode **vpp, struct componentname *cnp, ino_t *dd_ino) { 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 */ doff_t i_diroff; /* cached i_diroff value. */ doff_t i_offset; /* cached i_offset value. */ 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 namlen, error; struct ucred *cred = cnp->cn_cred; int flags = cnp->cn_flags; int nameiop = cnp->cn_nameiop; ino_t ino, ino1; int ltype; if (vpp != NULL) *vpp = NULL; dp = VTOI(vdp); if (dp->i_effnlink == 0) return (ENOENT); /* * Create a vm object if vmiodirenable is enabled. * Alternatively we could call vnode_create_vobject * in VFS_VGET but we could end up creating objects * that are never used. */ vnode_create_vobject(vdp, DIP(dp, i_size), cnp->cn_thread); bmask = VFSTOUFS(vdp->v_mount)->um_mountp->mnt_stat.f_iosize - 1; #ifdef QUOTA if ((nameiop == DELETE || nameiop == RENAME) && (flags & ISLASTCN)) { error = ufs_lookup_upgrade_lock(vdp); if (error != 0) return (error); } #endif restart: bp = NULL; slotoffset = -1; /* * 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. */ ino = 0; i_diroff = dp->i_diroff; slotstatus = FOUND; slotfreespace = slotsize = slotneeded = 0; if ((nameiop == CREATE || nameiop == RENAME) && (flags & ISLASTCN)) { slotstatus = NONE; slotneeded = DIRECTSIZ(cnp->cn_namelen); } #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, &i_offset, &bp, nameiop == DELETE ? &prevoff : NULL)) { case 0: ep = (struct direct *)((char *)bp->b_data + (i_offset & bmask)); goto foundentry; case ENOENT: 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 != LOOKUP || i_diroff == 0 || i_diroff >= dp->i_size) { entryoffsetinblock = 0; i_offset = 0; numdirpasses = 1; } else { i_offset = i_diroff; if ((entryoffsetinblock = i_offset & bmask) && (error = UFS_BLKATOFF(vdp, (off_t)i_offset, NULL, &bp))) return (error); numdirpasses = 2; nchstats.ncs_2passes++; } prevoff = i_offset; endsearch = roundup2(dp->i_size, DIRBLKSIZ); enduseful = 0; searchloop: while (i_offset < endsearch) { /* * If necessary, get the next directory block. */ if ((i_offset & bmask) == 0) { if (bp != NULL) brelse(bp); error = UFS_BLKATOFF(vdp, (off_t)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, i_offset, "mangled entry"); i = DIRBLKSIZ - (entryoffsetinblock & (DIRBLKSIZ - 1)); 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 = i_offset; slotsize = ep->d_reclen; } else if (slotstatus == NONE) { slotfreespace += size; if (slotoffset == -1) slotoffset = i_offset; if (slotfreespace >= slotneeded) { slotstatus = COMPACT; slotsize = 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 = i_offset; slotsize = ep->d_reclen; enduseful = dp->i_size; cnp->cn_flags |= ISWHITEOUT; numdirpasses--; goto notfound; } ino = ep->d_ino; goto found; } } prevoff = i_offset; i_offset += ep->d_reclen; entryoffsetinblock += ep->d_reclen; if (ep->d_ino) enduseful = 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--; i_offset = 0; endsearch = 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 == CREATE || nameiop == RENAME || (nameiop == DELETE && (cnp->cn_flags & DOWHITEOUT) && (cnp->cn_flags & ISWHITEOUT))) && (flags & ISLASTCN) && dp->i_effnlink != 0) { /* * Access for write is interpreted as allowing * creation of files in the directory. * * XXX: Fix the comment above. */ if (flags & WILLBEDIR) error = VOP_ACCESSX(vdp, VWRITE | VAPPEND, cred, cnp->cn_thread); else error = VOP_ACCESS(vdp, VWRITE, cred, cnp->cn_thread); 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 == 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); /* * 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. */ cnp->cn_flags |= SAVENAME; return (EJUSTRETURN); } /* * Insert name into cache (as non-existent) if appropriate. */ if ((cnp->cn_flags & MAKEENTRY) != 0) cache_enter(vdp, NULL, cnp); return (ENOENT); found: if (dd_ino != NULL) *dd_ino = ino; if (numdirpasses == 2) nchstats.ncs_pass2++; /* * Check that directory length properly reflects presence * of this entry. */ if (i_offset + DIRSIZ(OFSFMT(vdp), ep) > dp->i_size) { ufs_dirbad(dp, i_offset, "i_size too small"); dp->i_size = i_offset + DIRSIZ(OFSFMT(vdp), ep); DIP_SET(dp, i_size, dp->i_size); 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 ((flags & ISLASTCN) && nameiop == LOOKUP) dp->i_diroff = i_offset &~ (DIRBLKSIZ - 1); /* * If deleting, and at end of pathname, return * parameters which can be used to remove file. */ if (nameiop == DELETE && (flags & ISLASTCN)) { if (flags & LOCKPARENT) ASSERT_VOP_ELOCKED(vdp, __FUNCTION__); /* * 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(). * * Technically we shouldn't be setting these in the * WANTPARENT case (first lookup in rename()), but any * lookups that will result in directory changes will * overwrite these. */ dp->i_offset = i_offset; if ((dp->i_offset & (DIRBLKSIZ - 1)) == 0) dp->i_count = 0; else dp->i_count = dp->i_offset - prevoff; if (dd_ino != NULL) return (0); if ((error = VFS_VGET(vdp->v_mount, ino, LK_EXCLUSIVE, &tdp)) != 0) return (error); error = ufs_delete_denied(vdp, tdp, cred, cnp->cn_thread); if (error) { vput(tdp); return (error); } if (dp->i_number == ino) { VREF(vdp); *vpp = vdp; vput(tdp); return (0); } *vpp = tdp; 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 == RENAME && (flags & ISLASTCN)) { if (flags & WILLBEDIR) error = VOP_ACCESSX(vdp, VWRITE | VAPPEND, cred, cnp->cn_thread); else error = VOP_ACCESS(vdp, VWRITE, cred, cnp->cn_thread); if (error) return (error); /* * Careful about locking second inode. * This can only occur if the target is ".". */ dp->i_offset = i_offset; if (dp->i_number == ino) return (EISDIR); if (dd_ino != NULL) return (0); if ((error = VFS_VGET(vdp->v_mount, ino, LK_EXCLUSIVE, &tdp)) != 0) return (error); error = ufs_delete_denied(vdp, tdp, cred, cnp->cn_thread); if (error) { vput(tdp); return (error); } #ifdef SunOS_doesnt_do_that /* * The only purpose of this check is to return the correct * error. Assume that we want to rename directory "a" * to a file "b", and that we have no ACL_WRITE_DATA on * a containing directory, but we _do_ have ACL_APPEND_DATA. * In that case, the VOP_ACCESS check above will return 0, * and the operation will fail with ENOTDIR instead * of EACCESS. */ if (tdp->v_type == VDIR) error = VOP_ACCESSX(vdp, VWRITE | VAPPEND, cred, cnp->cn_thread); else error = VOP_ACCESS(vdp, VWRITE, cred, cnp->cn_thread); if (error) { vput(tdp); return (error); } #endif *vpp = tdp; cnp->cn_flags |= SAVENAME; return (0); } if (dd_ino != NULL) 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 & ISDOTDOT) { error = vn_vget_ino(pdp, ino, cnp->cn_lkflags, &tdp); if (error) return (error); /* * Recheck that ".." entry in the vdp directory points * to the inode we looked up before vdp lock was * dropped. */ error = ufs_lookup_ino(pdp, NULL, cnp, &ino1); if (error) { vput(tdp); return (error); } if (ino1 != ino) { vput(tdp); goto restart; } *vpp = tdp; } else if (dp->i_number == ino) { VREF(vdp); /* we want ourself, ie "." */ /* * When we lookup "." we still can be asked to lock it * differently. */ ltype = cnp->cn_lkflags & LK_TYPE_MASK; if (ltype != VOP_ISLOCKED(vdp)) { if (ltype == LK_EXCLUSIVE) vn_lock(vdp, LK_UPGRADE | LK_RETRY); else /* if (ltype == LK_SHARED) */ vn_lock(vdp, LK_DOWNGRADE | LK_RETRY); /* * Relock for the "." case may left us with * reclaimed vnode. */ if (vdp->v_iflag & VI_DOOMED) { vrele(vdp); return (ENOENT); } } *vpp = vdp; } else { error = VFS_VGET(pdp->v_mount, ino, cnp->cn_lkflags, &tdp); if (error) return (error); *vpp = tdp; } /* * Insert name into cache if appropriate. */ if (cnp->cn_flags & MAKEENTRY) cache_enter(vdp, *vpp, cnp); return (0); } void ufs_dirbad(ip, offset, how) struct inode *ip; doff_t offset; char *how; { struct mount *mp; mp = ITOV(ip)->v_mount; if ((mp->mnt_flag & MNT_RDONLY) == 0) panic("ufs_dirbad: %s: bad dir ino %ju at offset %ld: %s", mp->mnt_stat.f_mntonname, (uintmax_t)ip->i_number, (long)offset, how); else (void)printf("%s: bad dir ino %ju at offset %ld: %s\n", mp->mnt_stat.f_mntonname, (uintmax_t)ip->i_number, (long)offset, how); } /* * 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(dp, ep, entryoffsetinblock) struct vnode *dp; struct direct *ep; int entryoffsetinblock; { int i, 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); */ printf("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); */ printf("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(ip, cnp, newdirp) struct inode *ip; struct componentname *cnp; struct direct *newdirp; { #ifdef INVARIANTS if ((cnp->cn_flags & SAVENAME) == 0) panic("ufs_makedirentry: missing name"); #endif 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 nameidata. 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(dvp, tvp, dirp, cnp, newdirbp, isrename) struct vnode *dvp; struct vnode *tvp; struct direct *dirp; struct componentname *cnp; struct buf *newdirbp; int isrename; { struct ucred *cr; struct thread *td; int newentrysize; struct inode *dp; struct buf *bp; u_int dsize; struct direct *ep, *nep; int error, ret, blkoff, loc, spacefree, flags, namlen; char *dirbuf; td = curthread; /* XXX */ cr = td->td_ucred; 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"); flags = BA_CLRBUF; if (!DOINGSOFTDEP(dvp) && !DOINGASYNC(dvp)) flags |= IO_SYNC; #ifdef QUOTA if ((error = getinoquota(dp)) != 0) { if (DOINGSOFTDEP(dvp) && newdirbp != NULL) bdwrite(newdirbp); return (error); } #endif if ((error = UFS_BALLOC(dvp, (off_t)dp->i_offset, DIRBLKSIZ, cr, flags, &bp)) != 0) { if (DOINGSOFTDEP(dvp) && newdirbp != NULL) bdwrite(newdirbp); return (error); } dp->i_size = dp->i_offset + DIRBLKSIZ; DIP_SET(dp, i_size, dp->i_size); dp->i_flag |= IN_CHANGE | IN_UPDATE; vnode_pager_setsize(dvp, (u_long)dp->i_size); 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; } if (softdep_setup_directory_add(bp, dp, dp->i_offset, dirp->d_ino, newdirbp, 1)) dp->i_flag |= IN_NEEDSYNC; if (newdirbp) bdwrite(newdirbp); bdwrite(bp); if ((dp->i_flag & IN_NEEDSYNC) == 0) return (UFS_UPDATE(dvp, 0)); /* * We have just allocated a directory block in an * indirect block. We must prevent holes in the * directory created if directory entries are * written out of order. To accomplish this we * fsync when we extend a directory into indirects. * During rename it's not safe to drop the tvp lock * so sync must be delayed until it is. * * This synchronous step could be removed if fsck and * the kernel were taught to fill in sparse * directories rather than panic. */ if (isrename) return (0); if (tvp != NULL) VOP_UNLOCK(tvp, 0); (void) VOP_FSYNC(dvp, MNT_WAIT, td); if (tvp != NULL) vn_lock(tvp, LK_EXCLUSIVE | LK_RETRY); return (error); } if (DOINGASYNC(dvp)) { bdwrite(bp); return (UFS_UPDATE(dvp, 0)); } error = bwrite(bp); ret = UFS_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; DIP_SET(dp, i_size, dp->i_size); } /* * Get the block containing the space for the new directory entry. */ error = UFS_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(bp, 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 (BYTE_ORDER == LITTLE_ENDIAN) if (OFSFMT(dvp)) namlen = ep->d_type; else namlen = ep->d_namlen; # else namlen = ep->d_namlen; # endif if (ep->d_ino == 0 || (ep->d_ino == WINO && namlen == dirp->d_namlen && 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, (u_int)newentrysize); #ifdef UFS_DIRHASH if (dp->i_dirhash != NULL) ufsdirhash_checkblock(dp, dirbuf - (dp->i_offset & (DIRBLKSIZ - 1)), dp->i_offset & ~(DIRBLKSIZ - 1)); #endif if (DOINGSOFTDEP(dvp)) { (void) softdep_setup_directory_add(bp, dp, dp->i_offset + (caddr_t)ep - dirbuf, dirp->d_ino, newdirbp, 0); if (newdirbp != NULL) bdwrite(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 (isrename == 0 && error == 0 && dp->i_endoff && dp->i_endoff < dp->i_size) { if (tvp != NULL) VOP_UNLOCK(tvp, 0); error = UFS_TRUNCATE(dvp, (off_t)dp->i_endoff, IO_NORMAL | IO_SYNC, cr); if (error != 0) vprint("ufs_direnter: failted to truncate", dvp); #ifdef UFS_DIRHASH if (error == 0 && dp->i_dirhash != NULL) ufsdirhash_dirtrunc(dp, dp->i_endoff); #endif error = 0; 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 nameidata. 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(dvp, ip, flags, isrmdir) struct vnode *dvp; struct inode *ip; int flags; int isrmdir; { struct inode *dp; struct direct *ep, *rep; struct buf *bp; int error; dp = VTOI(dvp); /* * Adjust the link count early so softdep can block if necessary. */ if (ip) { ip->i_effnlink--; if (DOINGSOFTDEP(dvp)) { softdep_setup_unlink(dp, ip); } else { ip->i_nlink--; DIP_SET(ip, i_nlink, ip->i_nlink); ip->i_flag |= IN_CHANGE; } } if (flags & DOWHITEOUT) { /* * Whiteout entry: set d_ino to WINO. */ if ((error = UFS_BLKATOFF(dvp, (off_t)dp->i_offset, (char **)&ep, &bp)) != 0) return (error); ep->d_ino = WINO; ep->d_type = DT_WHT; goto out; } if ((error = UFS_BLKATOFF(dvp, (off_t)(dp->i_offset - dp->i_count), (char **)&ep, &bp)) != 0) return (error); /* Set 'rep' to the entry being removed. */ if (dp->i_count == 0) rep = ep; else rep = (struct direct *)((char *)ep + ep->d_reclen); #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, rep, dp->i_offset); #endif if (ip && rep->d_ino != ip->i_number) panic("ufs_dirremove: ip %ju does not match dirent ino %ju\n", (uintmax_t)ip->i_number, (uintmax_t)rep->d_ino); 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 += rep->d_reclen; } #ifdef UFS_DIRHASH if (dp->i_dirhash != NULL) ufsdirhash_checkblock(dp, (char *)ep - ((dp->i_offset - dp->i_count) & (DIRBLKSIZ - 1)), dp->i_offset & ~(DIRBLKSIZ - 1)); #endif out: error = 0; if (DOINGSOFTDEP(dvp)) { if (ip) softdep_setup_remove(bp, dp, ip, isrmdir); if (softdep_slowdown(dvp)) error = bwrite(bp); else bdwrite(bp); } else { if (flags & DOWHITEOUT) error = bwrite(bp); else if (DOINGASYNC(dvp) && dp->i_count != 0) bdwrite(bp); else error = bwrite(bp); } dp->i_flag |= IN_CHANGE | IN_UPDATE; /* * If the last named reference to a snapshot goes away, * drop its snapshot reference so that it will be reclaimed * when last open reference goes away. */ if (ip != 0 && (ip->i_flags & SF_SNAPSHOT) != 0 && ip->i_effnlink == 0) UFS_SNAPGONE(ip); 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(dp, oip, newinum, newtype, isrmdir) struct inode *dp, *oip; ino_t newinum; int newtype; int isrmdir; { struct buf *bp; struct direct *ep; struct vnode *vdp = ITOV(dp); int error; /* * Drop the link before we lock the buf so softdep can block if * necessary. */ oip->i_effnlink--; if (DOINGSOFTDEP(vdp)) { softdep_setup_unlink(dp, oip); } else { oip->i_nlink--; DIP_SET(oip, i_nlink, oip->i_nlink); oip->i_flag |= IN_CHANGE; } error = UFS_BLKATOFF(vdp, (off_t)dp->i_offset, (char **)&ep, &bp); if (error) return (error); if (ep->d_namlen == 2 && ep->d_name[1] == '.' && ep->d_name[0] == '.' && ep->d_ino != oip->i_number) { brelse(bp); return (EIDRM); } ep->d_ino = newinum; if (!OFSFMT(vdp)) ep->d_type = newtype; if (DOINGSOFTDEP(vdp)) { softdep_setup_directory_change(bp, dp, oip, newinum, isrmdir); bdwrite(bp); } else { if (DOINGASYNC(vdp)) { bdwrite(bp); error = 0; } else { error = bwrite(bp); } } dp->i_flag |= IN_CHANGE | IN_UPDATE; /* * If the last named reference to a snapshot goes away, * drop its snapshot reference so that it will be reclaimed * when last open reference goes away. */ if ((oip->i_flags & SF_SNAPSHOT) != 0 && oip->i_effnlink == 0) UFS_SNAPGONE(oip); 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(ip, parentino, cred) struct inode *ip; ino_t parentino; struct ucred *cred; { doff_t off; struct dirtemplate dbuf; struct direct *dp = (struct direct *)&dbuf; int error, namlen; ssize_t count; #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 | IO_NOMACCHECK, cred, NOCRED, &count, (struct thread *)0); /* * 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 == 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); } static int ufs_dir_dd_ino(struct vnode *vp, struct ucred *cred, ino_t *dd_ino, struct vnode **dd_vp) { struct dirtemplate dirbuf; struct vnode *ddvp; int error, namlen; ASSERT_VOP_LOCKED(vp, "ufs_dir_dd_ino"); if (vp->v_type != VDIR) return (ENOTDIR); /* * First check to see if we have it in the name cache. */ if ((ddvp = vn_dir_dd_ino(vp)) != NULL) { KASSERT(ddvp->v_mount == vp->v_mount, ("ufs_dir_dd_ino: Unexpected mount point crossing")); *dd_ino = VTOI(ddvp)->i_number; *dd_vp = ddvp; return (0); } /* * Have to read the directory. */ error = vn_rdwr(UIO_READ, vp, (caddr_t)&dirbuf, sizeof (struct dirtemplate), (off_t)0, UIO_SYSSPACE, IO_NODELOCKED | IO_NOMACCHECK, cred, NOCRED, NULL, NULL); if (error != 0) return (error); #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] != '.') return (ENOTDIR); *dd_ino = dirbuf.dotdot_ino; *dd_vp = NULL; return (0); } /* * Check if source directory is in the path of the target directory. */ int ufs_checkpath(ino_t source_ino, ino_t parent_ino, struct inode *target, struct ucred *cred, ino_t *wait_ino) { struct mount *mp; struct vnode *tvp, *vp, *vp1; int error; ino_t dd_ino; vp = tvp = ITOV(target); mp = vp->v_mount; *wait_ino = 0; if (target->i_number == source_ino) return (EEXIST); if (target->i_number == parent_ino) return (0); if (target->i_number == ROOTINO) return (0); for (;;) { error = ufs_dir_dd_ino(vp, cred, &dd_ino, &vp1); if (error != 0) break; if (dd_ino == source_ino) { error = EINVAL; break; } if (dd_ino == ROOTINO) break; if (dd_ino == parent_ino) break; if (vp1 == NULL) { error = VFS_VGET(mp, dd_ino, LK_SHARED | LK_NOWAIT, &vp1); if (error != 0) { *wait_ino = dd_ino; break; } } KASSERT(dd_ino == VTOI(vp1)->i_number, ("directory %d reparented\n", VTOI(vp1)->i_number)); if (vp != tvp) vput(vp); vp = vp1; } if (error == ENOTDIR) panic("checkpath: .. not a directory\n"); if (vp1 != NULL) vput(vp1); if (vp != tvp) vput(vp); return (error); }