/* * changed so that it confirms to ext2fs_check_dir_entry */ static int ext2fs_dirbadentry(struct vnode *dp, struct ext2fs_direct *de, int entryoffsetinblock) { struct ufsmount *ump = VFSTOUFS(dp->v_mount); int dirblksiz = ump->um_dirblksiz; const 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 (namlen > EXT2FS_MAXNAMLEN) error_msg = "namlen > EXT2FS_MAXNAMLEN"; else if (reclen < EXT2FS_DIRSIZ(namlen)) error_msg = "reclen is too small for name_len"; else if (entryoffsetinblock + reclen > dirblksiz) 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; }
static int mkentry(struct inodesc *idesc) { struct ext2fs_direct *dirp = idesc->id_dirp; struct ext2fs_direct newent; int newlen, oldlen; newent.e2d_type = 0; /* XXX gcc */ newent.e2d_namlen = strlen(idesc->id_name); if (sblock.e2fs.e2fs_rev > E2FS_REV0 && (sblock.e2fs.e2fs_features_incompat & EXT2F_INCOMPAT_FTYPE)) newent.e2d_type = inot2ext2dt(typemap[idesc->id_parent]); newlen = EXT2FS_DIRSIZ(newent.e2d_namlen); if (dirp->e2d_ino != 0) oldlen = EXT2FS_DIRSIZ(dirp->e2d_namlen); else oldlen = 0; if (fs2h16(dirp->e2d_reclen) - oldlen < newlen) return (KEEPON); newent.e2d_reclen = h2fs16(fs2h16(dirp->e2d_reclen) - oldlen); dirp->e2d_reclen = h2fs16(oldlen); dirp = (struct ext2fs_direct *)(((char *)dirp) + oldlen); dirp->e2d_ino = h2fs32(idesc->id_parent); /* ino to be entered is in id_parent */ dirp->e2d_reclen = newent.e2d_reclen; dirp->e2d_namlen = newent.e2d_namlen; dirp->e2d_type = newent.e2d_type; memcpy(dirp->e2d_name, idesc->id_name, (size_t)(dirp->e2d_namlen)); return (ALTERED|STOP); }
/* * Verify that a directory entry is valid. * This is a superset of the checks made in the kernel. */ int dircheck(struct inodesc *idesc, struct ext2fs_direct *dp) { int size; char *cp; int spaceleft; u_int16_t reclen = fs2h16(dp->e2d_reclen); spaceleft = sblock.e2fs_bsize - (idesc->id_loc % sblock.e2fs_bsize); if (fs2h32(dp->e2d_ino) > maxino || reclen == 0 || reclen > spaceleft || (reclen & 0x3) != 0) return (0); if (dp->e2d_ino == 0) return (1); if (sblock.e2fs.e2fs_rev < E2FS_REV1 || (sblock.e2fs.e2fs_features_incompat & EXT2F_INCOMPAT_FTYPE) == 0) if (dp->e2d_type != 0) return (1); size = EXT2FS_DIRSIZ(dp->e2d_namlen); if (reclen < size || idesc->id_filesize < size /* || dp->e2d_namlen > EXT2FS_MAXNAMLEN */) return (0); for (cp = dp->e2d_name, size = 0; size < dp->e2d_namlen; size++) if (*cp == '\0' || (*cp++ == '/')) return (0); return (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 * (ulr_offset, ulr_count) indicate how the space for the new * entry is to be obtained. */ int ext2fs_direnter(struct inode *ip, struct vnode *dvp, const struct ufs_lookup_results *ulr, 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; struct ufsmount *ump = VFSTOUFS(dvp->v_mount); int dirblksiz = ump->um_dirblksiz; 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 (ulr->ulr_count == 0) { /* * If ulr_count is 0, then namei could find no * space in the directory. Here, ulr_offset will * be on a directory block boundary and we will write the * new entry into a fresh block. */ if (ulr->ulr_offset & (dirblksiz - 1)) panic("ext2fs_direnter: newblk"); auio.uio_offset = ulr->ulr_offset; newdir.e2d_reclen = h2fs16(dirblksiz); auio.uio_resid = newentrysize; aiov.iov_len = newentrysize; aiov.iov_base = (void *)&newdir; auio.uio_iov = &aiov; auio.uio_iovcnt = 1; auio.uio_rw = UIO_WRITE; UIO_SETUP_SYSSPACE(&auio); error = VOP_WRITE(dvp, &auio, IO_SYNC, cnp->cn_cred); if (dirblksiz > dvp->v_mount->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), dirblksiz)); if (error) return (error); dp->i_flag |= IN_CHANGE; uvm_vnp_setsize(dvp, ext2fs_size(dp)); } return (error); } /* * If ulr_count is non-zero, then namei found space * for the new entry in the range ulr_offset to * ulr_offset + ulr_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_blkatoff(dvp, (off_t)ulr->ulr_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 ulr_offset to * ulr_offset + ulr_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 < ulr->ulr_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((void *)ep, (void *)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((void *)ep, (void *)&newdir, (u_int)newentrysize); error = VOP_BWRITE(bp->b_vp, bp); dp->i_flag |= IN_CHANGE | IN_UPDATE; if (!error && ulr->ulr_endoff && ulr->ulr_endoff < ext2fs_size(dp)) error = ext2fs_truncate(dvp, (off_t)ulr->ulr_endoff, IO_SYNC, cnp->cn_cred); 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_v2_args /* { struct vnode *a_dvp; struct vnode **a_vpp; struct componentname *a_cnp; } */ *ap = v; struct vnode *vdp = ap->a_dvp; /* vnode for directory being searched */ struct inode *dp = VTOI(vdp); /* 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 *tdp; /* returned by vcache_get */ doff_t enduseful; /* pointer past last used dir slot */ u_long bmask; /* block offset mask */ int namlen, error; struct vnode **vpp = ap->a_vpp; struct componentname *cnp = ap->a_cnp; kauth_cred_t cred = cnp->cn_cred; int flags; int nameiop = cnp->cn_nameiop; struct ufsmount *ump = dp->i_ump; int dirblksiz = ump->um_dirblksiz; ino_t foundino; struct ufs_lookup_results *results; flags = cnp->cn_flags; bp = NULL; slotoffset = -1; *vpp = NULL; /* * Produce the auxiliary lookup results into i_crap. Increment * its serial number so elsewhere we can tell if we're using * stale results. This should not be done this way. XXX. */ results = &dp->i_crap; dp->i_crapcounter++; /* * Check accessiblity of directory. */ if ((error = VOP_ACCESS(vdp, VEXEC, cred)) != 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 (cache_lookup(vdp, cnp->cn_nameptr, cnp->cn_namelen, cnp->cn_nameiop, cnp->cn_flags, NULL, vpp)) { return *vpp == NULLVP ? ENOENT : 0; } /* * 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 = vdp->v_mount->mnt_stat.f_iosize - 1; if (nameiop != LOOKUP || results->ulr_diroff == 0 || results->ulr_diroff >= ext2fs_size(dp)) { entryoffsetinblock = 0; results->ulr_offset = 0; numdirpasses = 1; } else { results->ulr_offset = results->ulr_diroff; if ((entryoffsetinblock = results->ulr_offset & bmask) && (error = ext2fs_blkatoff(vdp, (off_t)results->ulr_offset, NULL, &bp))) return (error); numdirpasses = 2; namecache_count_2passes(); } prevoff = results->ulr_offset; endsearch = roundup(ext2fs_size(dp), dirblksiz); enduseful = 0; searchloop: while (results->ulr_offset < endsearch) { if (curcpu()->ci_schedstate.spc_flags & SPCF_SHOULDYIELD) preempt(); /* * If necessary, get the next directory block. */ if ((results->ulr_offset & bmask) == 0) { if (bp != NULL) brelse(bp, 0); error = ext2fs_blkatoff(vdp, (off_t)results->ulr_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 & (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. */ KASSERT(bp != NULL); 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, results->ulr_offset, "mangled entry"); i = dirblksiz - (entryoffsetinblock & (dirblksiz - 1)); results->ulr_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 = results->ulr_offset; slotsize = fs2h16(ep->e2d_reclen); } else if (slotstatus == NONE) { slotfreespace += size; if (slotoffset == -1) slotoffset = results->ulr_offset; if (slotfreespace >= slotneeded) { slotstatus = COMPACT; slotsize = results->ulr_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. */ foundino = fs2h32(ep->e2d_ino); results->ulr_reclen = fs2h16(ep->e2d_reclen); goto found; } } prevoff = results->ulr_offset; results->ulr_offset += fs2h16(ep->e2d_reclen); entryoffsetinblock += fs2h16(ep->e2d_reclen); if (ep->e2d_ino) enduseful = results->ulr_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--; results->ulr_offset = 0; endsearch = results->ulr_diroff; goto searchloop; } if (bp != NULL) brelse(bp, 0); /* * 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) { /* * Access for write is interpreted as allowing * creation of files in the directory. */ error = VOP_ACCESS(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 results->ulr_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 results->ulr_offset to * results->ulr_offset + results->ulr_count. */ if (slotstatus == NONE) { results->ulr_offset = roundup(ext2fs_size(dp), dirblksiz); results->ulr_count = 0; enduseful = results->ulr_offset; } else { results->ulr_offset = slotoffset; results->ulr_count = slotsize; if (enduseful < slotoffset + slotsize) enduseful = slotoffset + slotsize; } results->ulr_endoff = roundup(enduseful, dirblksiz); #if 0 dp->i_flag |= IN_CHANGE | IN_UPDATE; #endif /* * 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. * * NB - if the directory is unlocked, then this * information cannot be used. */ return (EJUSTRETURN); } /* * Insert name into cache (as non-existent) if appropriate. */ if (nameiop != CREATE) { cache_enter(vdp, *vpp, cnp->cn_nameptr, cnp->cn_namelen, cnp->cn_flags); } return ENOENT; found: if (numdirpasses == 2) namecache_count_pass2(); /* * Check that directory length properly reflects presence * of this entry. */ if (results->ulr_offset + EXT2FS_DIRSIZ(ep->e2d_namlen) > ext2fs_size(dp)) { ufs_dirbad(dp, results->ulr_offset, "i_size too small"); error = ext2fs_setsize(dp, results->ulr_offset + EXT2FS_DIRSIZ(ep->e2d_namlen)); if (error) { brelse(bp, 0); return (error); } dp->i_flag |= IN_CHANGE | IN_UPDATE; uvm_vnp_setsize(vdp, ext2fs_size(dp)); } brelse(bp, 0); /* * 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) results->ulr_diroff = results->ulr_offset &~ (dirblksiz - 1); /* * If deleting, and at end of pathname, return * parameters which can be used to remove file. * Lock the inode, being careful with ".". */ if (nameiop == DELETE && (flags & ISLASTCN)) { /* * Return pointer to current entry in results->ulr_offset, * and distance past previous entry (if there * is a previous entry in this block) in results->ulr_count. * Save directory inode pointer in ndp->ni_dvp for dirremove(). */ if ((results->ulr_offset & (dirblksiz - 1)) == 0) results->ulr_count = 0; else results->ulr_count = results->ulr_offset - prevoff; if (dp->i_number == foundino) { vref(vdp); tdp = vdp; } else { error = vcache_get(vdp->v_mount, &foundino, sizeof(foundino), &tdp); if (error) return (error); } /* * Write access to directory required to delete files. */ if ((error = VOP_ACCESS(vdp, VWRITE, cred)) != 0) { vrele(tdp); 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) { error = kauth_authorize_vnode(cred, KAUTH_VNODE_DELETE, tdp, vdp, genfs_can_sticky(cred, dp->i_uid, VTOI(tdp)->i_uid)); if (error) { vrele(tdp); return (EPERM); } } *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)) { error = VOP_ACCESS(vdp, VWRITE, cred); if (error) return (error); /* * Careful about locking second inode. * This can only occur if the target is ".". */ if (dp->i_number == foundino) return (EISDIR); error = vcache_get(vdp->v_mount, &foundino, sizeof(foundino), &tdp); if (error) return (error); *vpp = tdp; return (0); } if (dp->i_number == foundino) { vref(vdp); /* we want ourself, ie "." */ *vpp = vdp; } else { error = vcache_get(vdp->v_mount, &foundino, sizeof(foundino), &tdp); if (error) return (error); *vpp = tdp; } /* * Insert name into cache if appropriate. */ cache_enter(vdp, *vpp, cnp->cn_nameptr, cnp->cn_namelen, cnp->cn_flags); return 0; }
static int pass2check(struct inodesc *idesc) { struct ext2fs_direct *dirp = idesc->id_dirp; struct inoinfo *inp; int n, entrysize, ret = 0; struct ext2fs_dinode *dp; char *errmsg; struct ext2fs_direct proto; char namebuf[MAXPATHLEN + 1]; char pathbuf[MAXPATHLEN + 1]; /* * check for "." */ if (idesc->id_entryno != 0) goto chk1; if (letoh32(dirp->e2d_ino) != 0 && dirp->e2d_namlen == 1 && dirp->e2d_name[0] == '.') { if (letoh32(dirp->e2d_ino) != idesc->id_number) { direrror(idesc->id_number, "BAD INODE NUMBER FOR '.'"); dirp->e2d_ino = htole32(idesc->id_number); if (reply("FIX") == 1) ret |= ALTERED; } if (sblock.e2fs.e2fs_rev > E2FS_REV0 && (sblock.e2fs.e2fs_features_incompat & EXT2F_INCOMPAT_FTYPE) && (dirp->e2d_type != EXT2_FT_DIR)) { direrror(idesc->id_number, "BAD TYPE VALUE FOR '.'"); dirp->e2d_type = EXT2_FT_DIR; if (reply("FIX") == 1) ret |= ALTERED; } goto chk1; } direrror(idesc->id_number, "MISSING '.'"); proto.e2d_ino = htole32(idesc->id_number); proto.e2d_namlen = 1; if (sblock.e2fs.e2fs_rev > E2FS_REV0 && (sblock.e2fs.e2fs_features_incompat & EXT2F_INCOMPAT_FTYPE)) proto.e2d_type = EXT2_FT_DIR; else proto.e2d_type = 0; (void)strlcpy(proto.e2d_name, ".", sizeof proto.e2d_name); entrysize = EXT2FS_DIRSIZ(proto.e2d_namlen); if (letoh32(dirp->e2d_ino) != 0 && strcmp(dirp->e2d_name, "..") != 0) { pfatal("CANNOT FIX, FIRST ENTRY IN DIRECTORY CONTAINS %s\n", dirp->e2d_name); } else if (letoh16(dirp->e2d_reclen) < entrysize) { pfatal("CANNOT FIX, INSUFFICIENT SPACE TO ADD '.'\n"); } else if (letoh16(dirp->e2d_reclen) < 2 * entrysize) { proto.e2d_reclen = dirp->e2d_reclen; memcpy(dirp, &proto, (size_t)entrysize); if (reply("FIX") == 1) ret |= ALTERED; } else { n = letoh16(dirp->e2d_reclen) - entrysize; proto.e2d_reclen = htole16(entrysize); memcpy(dirp, &proto, (size_t)entrysize); idesc->id_entryno++; lncntp[letoh32(dirp->e2d_ino)]--; dirp = (struct ext2fs_direct *)((char *)(dirp) + entrysize); memset(dirp, 0, (size_t)n); dirp->e2d_reclen = htole16(n); if (reply("FIX") == 1) ret |= ALTERED; } chk1: if (idesc->id_entryno > 1) goto chk2; inp = getinoinfo(idesc->id_number); proto.e2d_ino = htole32(inp->i_parent); proto.e2d_namlen = 2; if (sblock.e2fs.e2fs_rev > E2FS_REV0 && (sblock.e2fs.e2fs_features_incompat & EXT2F_INCOMPAT_FTYPE)) proto.e2d_type = EXT2_FT_DIR; else proto.e2d_type = 0; (void)strlcpy(proto.e2d_name, "..", sizeof proto.e2d_name); entrysize = EXT2FS_DIRSIZ(2); if (idesc->id_entryno == 0) { n = EXT2FS_DIRSIZ(dirp->e2d_namlen); if (letoh16(dirp->e2d_reclen) < n + entrysize) goto chk2; proto.e2d_reclen = htole16(letoh16(dirp->e2d_reclen) - n); dirp->e2d_reclen = htole16(n); idesc->id_entryno++; lncntp[letoh32(dirp->e2d_ino)]--; dirp = (struct ext2fs_direct *)((char *)(dirp) + n); memset(dirp, 0, (size_t)letoh16(proto.e2d_reclen)); dirp->e2d_reclen = proto.e2d_reclen; } if (letoh32(dirp->e2d_ino) != 0 && dirp->e2d_namlen == 2 && strncmp(dirp->e2d_name, "..", 2) == 0) { inp->i_dotdot = letoh32(dirp->e2d_ino); if (sblock.e2fs.e2fs_rev > E2FS_REV0 && (sblock.e2fs.e2fs_features_incompat & EXT2F_INCOMPAT_FTYPE) && dirp->e2d_type != EXT2_FT_DIR) { direrror(idesc->id_number, "BAD TYPE VALUE FOR '..'"); dirp->e2d_type = EXT2_FT_DIR; if (reply("FIX") == 1) ret |= ALTERED; } goto chk2; } if (letoh32(dirp->e2d_ino) != 0 && dirp->e2d_namlen == 1 && strncmp(dirp->e2d_name, ".", 1) != 0) { fileerror(inp->i_parent, idesc->id_number, "MISSING '..'"); pfatal("CANNOT FIX, SECOND ENTRY IN DIRECTORY CONTAINS %s\n", dirp->e2d_name); inp->i_dotdot = (ino_t)-1; } else if (letoh16(dirp->e2d_reclen) < entrysize) { fileerror(inp->i_parent, idesc->id_number, "MISSING '..'"); pfatal("CANNOT FIX, INSUFFICIENT SPACE TO ADD '..'\n"); inp->i_dotdot = (ino_t)-1; } else if (inp->i_parent != 0) { /* * We know the parent, so fix now. */ inp->i_dotdot = inp->i_parent; fileerror(inp->i_parent, idesc->id_number, "MISSING '..'"); proto.e2d_reclen = dirp->e2d_reclen; memcpy(dirp, &proto, (size_t)entrysize); if (reply("FIX") == 1) ret |= ALTERED; } idesc->id_entryno++; if (letoh32(dirp->e2d_ino) != 0) lncntp[letoh32(dirp->e2d_ino)]--; return (ret|KEEPON); chk2: if (letoh32(dirp->e2d_ino) == 0) return (ret|KEEPON); if (dirp->e2d_namlen <= 2 && dirp->e2d_name[0] == '.' && idesc->id_entryno >= 2) { if (dirp->e2d_namlen == 1) { direrror(idesc->id_number, "EXTRA '.' ENTRY"); dirp->e2d_ino = 0; if (reply("FIX") == 1) ret |= ALTERED; return (KEEPON | ret); } if (dirp->e2d_name[1] == '.') { direrror(idesc->id_number, "EXTRA '..' ENTRY"); dirp->e2d_ino = 0; if (reply("FIX") == 1) ret |= ALTERED; return (KEEPON | ret); } } idesc->id_entryno++; n = 0; if (letoh32(dirp->e2d_ino) > maxino || (letoh32(dirp->e2d_ino) < EXT2_FIRSTINO && letoh32(dirp->e2d_ino) != EXT2_ROOTINO)) { fileerror(idesc->id_number, letoh32(dirp->e2d_ino), "I OUT OF RANGE"); n = reply("REMOVE"); } else { again: switch (statemap[letoh32(dirp->e2d_ino)]) { case USTATE: if (idesc->id_entryno <= 2) break; fileerror(idesc->id_number, letoh32(dirp->e2d_ino), "UNALLOCATED"); n = reply("REMOVE"); break; case DCLEAR: case FCLEAR: if (idesc->id_entryno <= 2) break; if (statemap[letoh32(dirp->e2d_ino)] == FCLEAR) errmsg = "DUP/BAD"; else if (!preen) errmsg = "ZERO LENGTH DIRECTORY"; else { n = 1; break; } fileerror(idesc->id_number, letoh32(dirp->e2d_ino), errmsg); if ((n = reply("REMOVE")) == 1) break; dp = ginode(letoh32(dirp->e2d_ino)); statemap[letoh32(dirp->e2d_ino)] = (letoh16(dp->e2di_mode) & IFMT) == IFDIR ? DSTATE : FSTATE; lncntp[letoh32(dirp->e2d_ino)] = letoh16(dp->e2di_nlink); goto again; case DSTATE: case DFOUND: inp = getinoinfo(letoh32(dirp->e2d_ino)); if (inp->i_parent != 0 && idesc->id_entryno > 2) { getpathname(pathbuf, sizeof pathbuf, idesc->id_number, idesc->id_number); getpathname(namebuf, sizeof namebuf, letoh32(dirp->e2d_ino), letoh32(dirp->e2d_ino)); pwarn("%s %s %s\n", pathbuf, "IS AN EXTRANEOUS HARD LINK TO DIRECTORY", namebuf); if (preen) printf(" (IGNORED)\n"); else if ((n = reply("REMOVE")) == 1) break; } if (idesc->id_entryno > 2) inp->i_parent = idesc->id_number; /* fall through */ case FSTATE: if (sblock.e2fs.e2fs_rev > E2FS_REV0 && (sblock.e2fs.e2fs_features_incompat & EXT2F_INCOMPAT_FTYPE) && dirp->e2d_type != inot2ext2dt(typemap[letoh32(dirp->e2d_ino)])) { dirp->e2d_type = inot2ext2dt(typemap[letoh32(dirp->e2d_ino)]); fileerror(idesc->id_number, letoh32(dirp->e2d_ino), "BAD TYPE VALUE"); if (reply("FIX") == 1) ret |= ALTERED; } lncntp[letoh32(dirp->e2d_ino)]--; break; default: errexit("BAD STATE %d FOR INODE I=%llu\n", statemap[letoh32(dirp->e2d_ino)], (unsigned long long)letoh32(dirp->e2d_ino)); } } if (n == 0) return (ret|KEEPON); dirp->e2d_ino = 0; return (ret|KEEPON|ALTERED); }
/* * 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)) != 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)) != 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); 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)) != 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); 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)) != 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); 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); /* 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); cnp->cn_flags |= PDIRUNLOCK; } *vpp = tdp; } /* * Insert name into cache if appropriate. */ if (cnp->cn_flags & MAKEENTRY) cache_enter(vdp, *vpp, cnp); return (0); }