2 * link.c --- create links in a ext2fs directory
4 * Copyright (C) 1993, 1994 Theodore Ts'o.
7 * This file may be redistributed under the terms of the GNU Library
8 * General Public License, version 2.
29 unsigned int blocksize;
31 struct ext2_super_block *sb;
34 static int link_proc(struct ext2_dir_entry *dirent,
40 struct link_struct *ls = (struct link_struct *) priv_data;
41 struct ext2_dir_entry *next;
42 unsigned int rec_len, min_rec_len, curr_rec_len;
49 rec_len = EXT2_DIR_REC_LEN(ls->namelen);
51 ls->err = ext2fs_get_rec_len(ls->fs, dirent, &curr_rec_len);
55 if (EXT2_HAS_RO_COMPAT_FEATURE(ls->fs->super,
56 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
57 csum_size = sizeof(struct ext2_dir_entry_tail);
59 * See if the following directory entry (if any) is unused;
60 * if so, absorb it into this one.
62 next = (struct ext2_dir_entry *) (buf + offset + curr_rec_len);
63 if ((offset + (int) curr_rec_len < blocksize - (8 + csum_size)) &&
65 (offset + (int) curr_rec_len + (int) next->rec_len <= blocksize)) {
66 curr_rec_len += next->rec_len;
67 ls->err = ext2fs_set_rec_len(ls->fs, curr_rec_len, dirent);
74 * If the directory entry is used, see if we can split the
75 * directory entry to make room for the new name. If so,
76 * truncate it and return.
79 min_rec_len = EXT2_DIR_REC_LEN(ext2fs_dirent_name_len(dirent));
80 if (curr_rec_len < (min_rec_len + rec_len))
82 rec_len = curr_rec_len - min_rec_len;
83 ls->err = ext2fs_set_rec_len(ls->fs, min_rec_len, dirent);
86 next = (struct ext2_dir_entry *) (buf + offset +
89 ext2fs_dirent_set_name_len(next, 0);
90 ext2fs_dirent_set_file_type(next, 0);
91 ls->err = ext2fs_set_rec_len(ls->fs, rec_len, next);
94 return DIRENT_CHANGED;
98 * If we get this far, then the directory entry is not used.
99 * See if we can fit the request entry in. If so, do it.
101 if (curr_rec_len < rec_len)
103 dirent->inode = ls->inode;
104 ext2fs_dirent_set_name_len(dirent, ls->namelen);
105 strncpy(dirent->name, ls->name, ls->namelen);
106 if (ls->sb->s_feature_incompat & EXT2_FEATURE_INCOMPAT_FILETYPE)
107 ext2fs_dirent_set_file_type(dirent, ls->flags & 0x7);
110 return DIRENT_ABORT|DIRENT_CHANGED;
114 * Note: the low 3 bits of the flags field are used as the directory
120 errcode_t ext2fs_link(ext2_filsys fs, ext2_ino_t dir, const char *name,
121 ext2_ino_t ino, int flags)
124 struct link_struct ls;
125 struct ext2_inode inode;
127 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
129 if (!(fs->flags & EXT2_FLAG_RW))
130 return EXT2_ET_RO_FILSYS;
134 ls.namelen = name ? strlen(name) : 0;
139 ls.blocksize = fs->blocksize;
142 retval = ext2fs_dir_iterate(fs, dir, DIRENT_FLAG_INCLUDE_EMPTY,
150 return EXT2_ET_DIR_NO_SPACE;
152 if ((retval = ext2fs_read_inode(fs, dir, &inode)) != 0)
155 if (inode.i_flags & EXT2_INDEX_FL) {
156 inode.i_flags &= ~EXT2_INDEX_FL;
157 if ((retval = ext2fs_write_inode(fs, dir, &inode)) != 0)