/* $OpenBSD: ext2fs_lookup.c,v 1.30 2013/12/12 19:00:09 tedu Exp $ */ /* $NetBSD: ext2fs_lookup.c,v 1.16 2000/08/03 20:29:26 thorpej Exp $ */ /* * Modified for NetBSD 1.2E * May 1997, Manuel Bouyer * Laboratoire d'informatique de Paris VI */ /* * modified for Lites 1.1 * * Aug 1995, Godmar Back (gback@cs.utah.edu) * University of Utah, Department of Computer Science */ /* * 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 8.6 (Berkeley) 4/1/94 */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include extern int dirchk; static void ext2fs_dirconv2ffs(struct ext2fs_direct *e2dir, struct dirent *ffsdir); static int ext2fs_dirbadentry(struct vnode *dp, struct ext2fs_direct *de, int entryoffsetinblock); /* * the problem that is tackled below is the fact that FFS * includes the terminating zero on disk while EXT2FS doesn't * this implies that we need to introduce some padding. * For instance, a filename "sbin" has normally a reclen 12 * in EXT2, but 16 in FFS. * This reminds me of that Pepsi commercial: 'Kid saved a lousy nine cents...' * If it wasn't for that, the complete ufs code for directories would * have worked w/o changes (except for the difference in DIRBLKSIZ) */ static void ext2fs_dirconv2ffs(struct ext2fs_direct *e2dir, struct dirent *ffsdir) { memset(ffsdir, 0, sizeof(struct dirent)); ffsdir->d_fileno = fs2h32(e2dir->e2d_ino); ffsdir->d_namlen = e2dir->e2d_namlen; ffsdir->d_type = DT_UNKNOWN; /* don't know more here */ #ifdef DIAGNOSTIC /* * XXX Rigth now this can't happen, but if one day * MAXNAMLEN != E2FS_MAXNAMLEN we should handle this more gracefully ! */ /* XXX: e2d_namlen is to small for such comparison if (e2dir->e2d_namlen > MAXNAMLEN) panic("ext2fs: e2dir->e2d_namlen"); */ #endif strncpy(ffsdir->d_name, e2dir->e2d_name, ffsdir->d_namlen); /* Godmar thinks: since e2dir->e2d_reclen can be big and means nothing anyway, we compute our own reclen according to what we think is right */ ffsdir->d_reclen = DIRENT_SIZE(ffsdir); } /* * Vnode op for reading directories. * * Convert the on-disk entries to entries. * the problem is that the conversion will blow up some entries by four bytes, * so it can't be done in place. This is too bad. Right now the conversion is * done entry by entry, the converted entry is sent via uiomove. * * XXX allocate a buffer, convert as many entries as possible, then send * the whole buffer to uiomove */ int ext2fs_readdir(void *v) { struct vop_readdir_args *ap = v; struct uio *uio = ap->a_uio; int error; size_t e2fs_count, readcnt, entries; struct vnode *vp = ap->a_vp; struct m_ext2fs *fs = VTOI(vp)->i_e2fs; struct ext2fs_direct *dp; struct dirent dstd; struct uio auio; struct iovec aiov; caddr_t dirbuf; off_t off = uio->uio_offset; int e2d_reclen; if (vp->v_type != VDIR) return (ENOTDIR); e2fs_count = uio->uio_resid; entries = (uio->uio_offset + e2fs_count) & (fs->e2fs_bsize - 1); /* Make sure we don't return partial entries. */ if (e2fs_count <= entries) return (EINVAL); e2fs_count -= entries; auio = *uio; auio.uio_iov = &aiov; auio.uio_iovcnt = 1; auio.uio_segflg = UIO_SYSSPACE; aiov.iov_len = e2fs_count; auio.uio_resid = e2fs_count; dirbuf = malloc(e2fs_count, M_TEMP, M_WAITOK | M_ZERO); aiov.iov_base = dirbuf; error = VOP_READ(ap->a_vp, &auio, 0, ap->a_cred); if (error == 0) { readcnt = e2fs_count - auio.uio_resid; for (dp = (struct ext2fs_direct *)dirbuf; (char *)dp < (char *)dirbuf + readcnt; ) { e2d_reclen = fs2h16(dp->e2d_reclen); if (e2d_reclen == 0) { error = EIO; break; } ext2fs_dirconv2ffs(dp, &dstd); if(dstd.d_reclen > uio->uio_resid) { break; } dstd.d_off = off + e2d_reclen; if ((error = uiomove((caddr_t)&dstd, dstd.d_reclen, uio)) != 0) { break; } off = off + e2d_reclen; /* advance dp */ dp = (struct ext2fs_direct *) ((char *)dp + e2d_reclen); } /* we need to correct uio_offset */ uio->uio_offset = off; } free(dirbuf, M_TEMP); *ap->a_eofflag = ext2fs_size(VTOI(ap->a_vp)) <= uio->uio_offset; return (error); } /* * Convert a component of a pathname into a pointer to a locked inode. * This is a very central and rather complicated routine. * If the file system 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 ext2fs_lookup: * * check accessibility of directory * look for name in cache, if found, then if at end of path * and deleting or creating, drop it, else return name * 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 ext2fs_lookup(void *v) { struct vop_lookup_args *ap = v; 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 ext2fs_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; struct proc *p = cnp->cn_proc; int dirblksize = VTOI(ap->a_dvp)->i_e2fs->e2fs_bsize; bp = NULL; slotoffset = -1; *vpp = NULL; vdp = ap->a_dvp; dp = VTOI(vdp); lockparent = flags & LOCKPARENT; wantparent = flags & (LOCKPARENT|WANTPARENT); /* * Check accessiblity of directory. */ if ((error = VOP_ACCESS(vdp, VEXEC, cred, cnp->cn_proc)) != 0) return (error); if ((flags & ISLASTCN) && (vdp->v_mount->mnt_flag & MNT_RDONLY) && (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME)) return (EROFS); /* * We now have a segment name to search for, and a directory to search. * * Before tediously performing a linear scan of the directory, * check the name cache to see if the directory/name pair * we are looking for is known already. */ if ((error = cache_lookup(vdp, vpp, cnp)) >= 0) return (error); /* * 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 == CREATE || nameiop == RENAME) && (flags & ISLASTCN)) { slotstatus = NONE; slotneeded = EXT2FS_DIRSIZ(cnp->cn_namelen); } /* * 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. */ bmask = VFSTOUFS(vdp->v_mount)->um_mountp->mnt_stat.f_iosize - 1; if (nameiop != LOOKUP || dp->i_diroff == 0 || dp->i_diroff >ext2fs_size(dp)) { entryoffsetinblock = 0; dp->i_offset = 0; numdirpasses = 1; } else { dp->i_offset = dp->i_diroff; if ((entryoffsetinblock = dp->i_offset & bmask) && (error = ext2fs_bufatoff(dp, (off_t)dp->i_offset, NULL, &bp))) return (error); numdirpasses = 2; } prevoff = dp->i_offset; endsearch = roundup(ext2fs_size(dp), dirblksize); 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 = ext2fs_bufatoff(dp, (off_t)dp->i_offset, NULL, &bp); if (error != 0) 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 & (dirblksize - 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 ext2fs_direct *) ((char *)bp->b_data + entryoffsetinblock); if (ep->e2d_reclen == 0 || (dirchk && ext2fs_dirbadentry(vdp, ep, entryoffsetinblock))) { int i; ufs_dirbad(dp, dp->i_offset, "mangled entry"); i = dirblksize - (entryoffsetinblock & (dirblksize - 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 = fs2h16(ep->e2d_reclen); if (ep->e2d_ino != 0) size -= EXT2FS_DIRSIZ(ep->e2d_namlen); if (size > 0) { if (size >= slotneeded) { slotstatus = FOUND; slotoffset = dp->i_offset; slotsize = fs2h16(ep->e2d_reclen); } else if (slotstatus == NONE) { slotfreespace += size; if (slotoffset == -1) slotoffset = dp->i_offset; if (slotfreespace >= slotneeded) { slotstatus = COMPACT; slotsize = dp->i_offset + fs2h16(ep->e2d_reclen) - slotoffset; } } } } /* * Check for a name match. */ if (ep->e2d_ino) { namlen = ep->e2d_namlen; if (namlen == cnp->cn_namelen && !memcmp(cnp->cn_nameptr, ep->e2d_name, (unsigned)namlen)) { /* * Save directory entry's inode number and * reclen in ndp->ni_ufs area, and release * directory buffer. */ dp->i_ino = fs2h32(ep->e2d_ino); dp->i_reclen = fs2h16(ep->e2d_reclen); brelse(bp); goto found; } } prevoff = dp->i_offset; dp->i_offset += fs2h16(ep->e2d_reclen); entryoffsetinblock += fs2h16(ep->e2d_reclen); if (ep->e2d_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 == CREATE || nameiop == RENAME) && (flags & ISLASTCN) && dp->i_e2fs_nlink != 0) { /* * Creation of files on a read-only mounted file system * is pointless, so don't proceed any further. */ if (vdp->v_mount->mnt_flag & MNT_RDONLY) return (EROFS); /* * Access for write is interpreted as allowing * creation of files in the directory. */ if ((error = VOP_ACCESS(vdp, VWRITE, cred, cnp->cn_proc)) != 0) 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 = roundup(ext2fs_size(dp), dirblksize); dp->i_count = 0; enduseful = dp->i_offset; } else { dp->i_offset = slotoffset; dp->i_count = slotsize; if (enduseful < slotoffset + slotsize) enduseful = slotoffset + slotsize; } dp->i_endoff = roundup(enduseful, dirblksize); 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. */ cnp->cn_flags |= SAVENAME; if (!lockparent) { VOP_UNLOCK(vdp, 0, p); cnp->cn_flags |= PDIRUNLOCK; } return (EJUSTRETURN); } /* * Insert name into cache (as non-existent) if appropriate. */ if ((cnp->cn_flags & MAKEENTRY) && nameiop != CREATE) cache_enter(vdp, *vpp, cnp); return (ENOENT); found: /* * Check that directory length properly reflects presence * of this entry. */ if (entryoffsetinblock + EXT2FS_DIRSIZ(ep->e2d_namlen) > ext2fs_size(dp)) { ufs_dirbad(dp, dp->i_offset, "i_size too small"); error = ext2fs_setsize(dp, entryoffsetinblock + EXT2FS_DIRSIZ(ep->e2d_namlen)); if (error) { brelse(bp); return(error); } dp->i_flag |= IN_CHANGE | IN_UPDATE; } /* * 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 = dp->i_offset &~ (dirblksize - 1); /* * 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 == DELETE && (flags & ISLASTCN)) { /* * Write access to directory required to delete files. */ if ((error = VOP_ACCESS(vdp, VWRITE, cred, cnp->cn_proc)) != 0) 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 & (dirblksize - 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 ((error = VFS_VGET(vdp->v_mount, dp->i_ino, &tdp)) != 0) 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_e2fs_mode & ISVTX) && cred->cr_uid != 0 && cred->cr_uid != dp->i_e2fs_uid && VTOI(tdp)->i_e2fs_uid != cred->cr_uid) { vput(tdp); return (EPERM); } *vpp = tdp; if (!lockparent) { VOP_UNLOCK(vdp, 0, p); cnp->cn_flags |= 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 == RENAME && wantparent && (flags & ISLASTCN)) { if ((error = VOP_ACCESS(vdp, VWRITE, cred, cnp->cn_proc)) != 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 ((error = VFS_VGET(vdp->v_mount, dp->i_ino, &tdp)) != 0) return (error); *vpp = tdp; cnp->cn_flags |= SAVENAME; if (!lockparent) { VOP_UNLOCK(vdp, 0, p); cnp->cn_flags |= 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 file system has any hard links other than ".." * that point backwards in the directory structure. */ pdp = vdp; if (flags & ISDOTDOT) { VOP_UNLOCK(pdp, 0, p); /* race to get the inode */ cnp->cn_flags |= PDIRUNLOCK; if ((error = VFS_VGET(vdp->v_mount, dp->i_ino, &tdp)) != 0) { if (vn_lock(pdp, LK_EXCLUSIVE | LK_RETRY, p) == 0) cnp->cn_flags &= ~PDIRUNLOCK; return (error); } if (lockparent && (flags & ISLASTCN)) { if ((error = vn_lock(pdp, LK_EXCLUSIVE, p)) != 0) { vput(tdp); return (error); } cnp->cn_flags &= ~PDIRUNLOCK; } *vpp = tdp; } else if (dp->i_number == dp->i_ino) { vref(vdp); /* we want ourself, ie "." */ *vpp = vdp; } else { if ((error = VFS_VGET(vdp->v_mount, dp->i_ino, &tdp)) != 0) return (error); if (!lockparent || !(flags & ISLASTCN)) { VOP_UNLOCK(pdp, 0, p); cnp->cn_flags |= PDIRUNLOCK; } *vpp = tdp; } /* * Insert name into cache if appropriate. */ if (cnp->cn_flags & MAKEENTRY) cache_enter(vdp, *vpp, cnp); return (0); } /* * Do consistency checking on a directory entry: * record length must be multiple of 4 * entry must fit in rest of its dirblksize 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 */ /* * changed so that it confirms to ext2fs_check_dir_entry */ static int ext2fs_dirbadentry(struct vnode *dp, struct ext2fs_direct *de, int entryoffsetinblock) { int dirblksize = VTOI(dp)->i_e2fs->e2fs_bsize; char * error_msg = NULL; int reclen = fs2h16(de->e2d_reclen); int namlen = de->e2d_namlen; if (reclen < EXT2FS_DIRSIZ(1)) /* e2d_namlen = 1 */ error_msg = "rec_len is smaller than minimal"; else if (reclen % 4 != 0) error_msg = "rec_len % 4 != 0"; else if (reclen < EXT2FS_DIRSIZ(namlen)) error_msg = "reclen is too small for name_len"; else if (entryoffsetinblock + reclen > dirblksize) error_msg = "directory entry across blocks"; else if (fs2h32(de->e2d_ino) > VTOI(dp)->i_e2fs->e2fs.e2fs_icount) error_msg = "inode out of bounds"; if (error_msg != NULL) { printf( "bad directory entry: %s\n" "offset=%d, inode=%lu, rec_len=%d, name_len=%d \n", error_msg, entryoffsetinblock, (unsigned long) fs2h32(de->e2d_ino), reclen, namlen); panic("ext2fs_dirbadentry"); } return error_msg == NULL ? 0 : 1; } /* * Write a directory entry after a call to namei, using the parameters * that it left in nameidata. The argument ip is the inode which the new * directory entry will refer to. 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. */ int ext2fs_direnter(struct inode *ip, struct vnode *dvp, struct componentname *cnp) { struct ext2fs_direct *ep, *nep; struct inode *dp; struct buf *bp; struct ext2fs_direct newdir; struct iovec aiov; struct uio auio; u_int dsize; int error, loc, newentrysize, spacefree; char *dirbuf; int dirblksize = ip->i_e2fs->e2fs_bsize; #ifdef DIAGNOSTIC if ((cnp->cn_flags & SAVENAME) == 0) panic("direnter: missing name"); #endif dp = VTOI(dvp); newdir.e2d_ino = h2fs32(ip->i_number); newdir.e2d_namlen = cnp->cn_namelen; if (ip->i_e2fs->e2fs.e2fs_rev > E2FS_REV0 && (ip->i_e2fs->e2fs.e2fs_features_incompat & EXT2F_INCOMPAT_FTYPE)) { newdir.e2d_type = inot2ext2dt(IFTODT(ip->i_e2fs_mode)); } else { newdir.e2d_type = 0; }; memcpy(newdir.e2d_name, cnp->cn_nameptr, (unsigned)cnp->cn_namelen + 1); newentrysize = EXT2FS_DIRSIZ(cnp->cn_namelen); 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 & (dirblksize - 1)) panic("ext2fs_direnter: newblk"); auio.uio_offset = dp->i_offset; newdir.e2d_reclen = h2fs16(dirblksize); auio.uio_resid = newentrysize; aiov.iov_len = newentrysize; aiov.iov_base = (caddr_t)&newdir; auio.uio_iov = &aiov; auio.uio_iovcnt = 1; auio.uio_rw = UIO_WRITE; auio.uio_segflg = UIO_SYSSPACE; auio.uio_procp = (struct proc *)0; error = VOP_WRITE(dvp, &auio, IO_SYNC, cnp->cn_cred); if (dirblksize > VFSTOUFS(dvp->v_mount)->um_mountp->mnt_stat.f_bsize) /* XXX should grow with balloc() */ panic("ext2fs_direnter: frag size"); else if (!error) { error = ext2fs_setsize(dp, roundup(ext2fs_size(dp), dirblksize)); if (error) return (error); dp->i_flag |= IN_CHANGE; } 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. */ /* * Get the block containing the space for the new directory entry. */ if ((error = ext2fs_bufatoff(dp, (off_t)dp->i_offset, &dirbuf, &bp)) != 0) 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 ext2fs_direct *)dirbuf; dsize = EXT2FS_DIRSIZ(ep->e2d_namlen); spacefree = fs2h16(ep->e2d_reclen) - dsize; for (loc = fs2h16(ep->e2d_reclen); loc < dp->i_count; ) { nep = (struct ext2fs_direct *)(dirbuf + loc); if (ep->e2d_ino) { /* trim the existing slot */ ep->e2d_reclen = h2fs16(dsize); ep = (struct ext2fs_direct *)((char *)ep + dsize); } else { /* overwrite; nothing there; header is ours */ spacefree += dsize; } dsize = EXT2FS_DIRSIZ(nep->e2d_namlen); spacefree += fs2h16(nep->e2d_reclen) - dsize; loc += fs2h16(nep->e2d_reclen); memcpy(ep, nep, dsize); } /* * Update the pointer fields in the previous entry (if any), * copy in the new entry, and write out the block. */ if (ep->e2d_ino == 0) { #ifdef DIAGNOSTIC if (spacefree + dsize < newentrysize) panic("ext2fs_direnter: compact1"); #endif newdir.e2d_reclen = h2fs16(spacefree + dsize); } else { #ifdef DIAGNOSTIC if (spacefree < newentrysize) { printf("ext2fs_direnter: compact2 %u %u", (u_int)spacefree, (u_int)newentrysize); panic("ext2fs_direnter: compact2"); } #endif newdir.e2d_reclen = h2fs16(spacefree); ep->e2d_reclen = h2fs16(dsize); ep = (struct ext2fs_direct *)((char *)ep + dsize); } memcpy(ep, &newdir, newentrysize); error = VOP_BWRITE(bp); dp->i_flag |= IN_CHANGE | IN_UPDATE; if (!error && dp->i_endoff && dp->i_endoff < ext2fs_size(dp)) error = ext2fs_truncate(dp, (off_t)dp->i_endoff, IO_SYNC, cnp->cn_cred); 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 ext2fs_dirremove(struct vnode *dvp, struct componentname *cnp) { struct inode *dp; struct ext2fs_direct *ep; struct buf *bp; int error; dp = VTOI(dvp); if (dp->i_count == 0) { /* * First entry in block: set d_ino to zero. */ error = ext2fs_bufatoff(dp, (off_t)dp->i_offset, (char **)&ep, &bp); if (error != 0) return (error); ep->e2d_ino = 0; error = VOP_BWRITE(bp); dp->i_flag |= IN_CHANGE | IN_UPDATE; return (error); } /* * Collapse new free space into previous entry. */ error = ext2fs_bufatoff(dp, (off_t)(dp->i_offset - dp->i_count), (char **)&ep, &bp); if (error != 0) return (error); ep->e2d_reclen = h2fs16(fs2h16(ep->e2d_reclen) + dp->i_reclen); error = VOP_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 ext2fs_dirrewrite(struct inode *dp, struct inode *ip, struct componentname *cnp) { struct buf *bp; struct ext2fs_direct *ep; int error; error = ext2fs_bufatoff(dp, (off_t)dp->i_offset, (char **)&ep, &bp); if (error != 0) return (error); ep->e2d_ino = h2fs32(ip->i_number); if (ip->i_e2fs->e2fs.e2fs_rev > E2FS_REV0 && (ip->i_e2fs->e2fs.e2fs_features_incompat & EXT2F_INCOMPAT_FTYPE)) { ep->e2d_type = inot2ext2dt(IFTODT(ip->i_e2fs_mode)); } else { ep->e2d_type = 0; } error = VOP_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 ext2fs_direct. * * NB: does not handle corrupted directories. */ int ext2fs_dirempty(struct inode *ip, ufsino_t parentino, struct ucred *cred) { off_t off; struct ext2fs_dirtemplate dbuf; struct ext2fs_direct *dp = (struct ext2fs_direct *)&dbuf; int error, namlen; size_t count; #define MINDIRSIZ (sizeof (struct ext2fs_dirtemplate) / 2) for (off = 0; off < ext2fs_size(ip); off += fs2h16(dp->e2d_reclen)) { error = vn_rdwr(UIO_READ, ITOV(ip), (caddr_t)dp, MINDIRSIZ, off, UIO_SYSSPACE, IO_NODELOCKED, cred, &count, curproc); /* * 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->e2d_reclen == 0) return (0); /* skip empty entries */ if (dp->e2d_ino == 0) continue; /* accept only "." and ".." */ namlen = dp->e2d_namlen; if (namlen > 2) return (0); if (dp->e2d_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) continue; if (dp->e2d_name[1] == '.' && fs2h32(dp->e2d_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 ext2fs_checkpath(struct inode *source, struct inode *target, struct ucred *cred) { struct vnode *vp; int error, rootino, namlen; struct ext2fs_dirtemplate dirbuf; u_int32_t ino; vp = ITOV(target); if (target->i_number == source->i_number) { error = EEXIST; goto out; } rootino = 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 ext2fs_dirtemplate), (off_t)0, UIO_SYSSPACE, IO_NODELOCKED, cred, NULL, curproc); if (error != 0) break; namlen = dirbuf.dotdot_namlen; if (namlen != 2 || dirbuf.dotdot_name[0] != '.' || dirbuf.dotdot_name[1] != '.') { error = ENOTDIR; break; } ino = fs2h32(dirbuf.dotdot_ino); if (ino == source->i_number) { error = EINVAL; break; } if (ino == rootino) break; vput(vp); error = VFS_VGET(vp->v_mount, ino, &vp); if (error != 0) { vp = NULL; break; } } out: if (error == ENOTDIR) { printf("checkpath: .. not a directory\n"); panic("checkpath"); } if (vp != NULL) vput(vp); return (error); }