| /* |
| * 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 |
| |
| #if EXT2_FLAT_INCLUDES |
| #include "ext2_fs.h" |
| #else |
| #include <linux/ext2_fs.h> |
| #endif |
| |
| #include "ext2fs.h" |
| |
| struct link_struct { |
| const char *name; |
| int namelen; |
| ino_t inode; |
| int flags; |
| int done; |
| struct ext2fs_sb *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, ino_t dir, const char *name, ino_t ino, |
| int flags) |
| { |
| errcode_t retval; |
| struct link_struct ls; |
| |
| 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 = (struct ext2fs_sb *) fs->super; |
| |
| retval = ext2fs_dir_iterate(fs, dir, DIRENT_FLAG_INCLUDE_EMPTY, |
| 0, link_proc, &ls); |
| if (retval) |
| return retval; |
| |
| return (ls.done) ? 0 : EXT2_ET_DIR_NO_SPACE; |
| } |