/* vi: set sw=4 ts=4: */ /* * link.c --- create links in a ext2fs directory * * Copyright (C) 1993, 1994 Theodore Ts'o. * * %Begin-Header% * This file may be redistributed under the terms of the GNU Public * License. * %End-Header% */ #include <stdio.h> #include <string.h> #if HAVE_UNISTD_H #include <unistd.h> #endif #include "ext2_fs.h" #include "ext2fs.h" struct link_struct { const char *name; int namelen; ext2_ino_t inode; int flags; int done; struct ext2_super_block *sb; }; static int link_proc(struct ext2_dir_entry *dirent, int offset, int blocksize, char *buf, void *priv_data) { struct link_struct *ls = (struct link_struct *) priv_data; struct ext2_dir_entry *next; int rec_len, min_rec_len; int ret = 0; rec_len = EXT2_DIR_REC_LEN(ls->namelen); /* * See if the following directory entry (if any) is unused; * if so, absorb it into this one. */ next = (struct ext2_dir_entry *) (buf + offset + dirent->rec_len); if ((offset + dirent->rec_len < blocksize - 8) && (next->inode == 0) && (offset + dirent->rec_len + next->rec_len <= blocksize)) { dirent->rec_len += next->rec_len; ret = DIRENT_CHANGED; } /* * If the directory entry is used, see if we can split the * directory entry to make room for the new name. If so, * truncate it and return. */ if (dirent->inode) { min_rec_len = EXT2_DIR_REC_LEN(dirent->name_len & 0xFF); if (dirent->rec_len < (min_rec_len + rec_len)) return ret; rec_len = dirent->rec_len - min_rec_len; dirent->rec_len = min_rec_len; next = (struct ext2_dir_entry *) (buf + offset + dirent->rec_len); next->inode = 0; next->name_len = 0; next->rec_len = rec_len; return DIRENT_CHANGED; } /* * If we get this far, then the directory entry is not used. * See if we can fit the request entry in. If so, do it. */ if (dirent->rec_len < rec_len) return ret; dirent->inode = ls->inode; dirent->name_len = ls->namelen; strncpy(dirent->name, ls->name, ls->namelen); if (ls->sb->s_feature_incompat & EXT2_FEATURE_INCOMPAT_FILETYPE) dirent->name_len |= (ls->flags & 0x7) << 8; ls->done++; return DIRENT_ABORT|DIRENT_CHANGED; } /* * Note: the low 3 bits of the flags field are used as the directory * entry filetype. */ #ifdef __TURBOC__ # pragma argsused #endif errcode_t ext2fs_link(ext2_filsys fs, ext2_ino_t dir, const char *name, ext2_ino_t ino, int flags) { errcode_t retval; struct link_struct ls; struct ext2_inode inode; EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); if (!(fs->flags & EXT2_FLAG_RW)) return EXT2_ET_RO_FILSYS; ls.name = name; ls.namelen = name ? strlen(name) : 0; ls.inode = ino; ls.flags = flags; ls.done = 0; ls.sb = fs->super; retval = ext2fs_dir_iterate(fs, dir, DIRENT_FLAG_INCLUDE_EMPTY, 0, link_proc, &ls); if (retval) return retval; if (!ls.done) return EXT2_ET_DIR_NO_SPACE; if ((retval = ext2fs_read_inode(fs, dir, &inode)) != 0) return retval; if (inode.i_flags & EXT2_INDEX_FL) { inode.i_flags &= ~EXT2_INDEX_FL; if ((retval = ext2fs_write_inode(fs, dir, &inode)) != 0) return retval; } return 0; }