1 /* vi: set sw=4 ts=4: */
3 * dir_iterate.c --- ext2fs directory iteration operations
5 * Copyright (C) 1993, 1994, 1994, 1995, 1996, 1997 Theodore Ts'o.
8 * This file may be redistributed under the terms of the GNU Public
26 * This function checks to see whether or not a potential deleted
27 * directory entry looks valid. What we do is check the deleted entry
28 * and each successive entry to make sure that they all look valid and
29 * that the last deleted entry ends at the beginning of the next
30 * undeleted entry. Returns 1 if the deleted entry looks valid, zero
33 static int ext2fs_validate_entry(char *buf, int offset, int final_offset)
35 struct ext2_dir_entry *dirent;
37 while (offset < final_offset) {
38 dirent = (struct ext2_dir_entry *)(buf + offset);
39 offset += dirent->rec_len;
40 if ((dirent->rec_len < 8) ||
41 ((dirent->rec_len % 4) != 0) ||
42 (((dirent->name_len & 0xFF)+8) > dirent->rec_len))
45 return (offset == final_offset);
48 errcode_t ext2fs_dir_iterate2(ext2_filsys fs,
52 int (*func)(ext2_ino_t dir,
54 struct ext2_dir_entry *dirent,
61 struct dir_context ctx;
64 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
66 retval = ext2fs_check_directory(fs, dir);
75 retval = ext2fs_get_mem(fs->blocksize, &ctx.buf);
80 ctx.priv_data = priv_data;
82 retval = ext2fs_block_iterate2(fs, dir, 0, 0,
83 ext2fs_process_dir_block, &ctx);
85 ext2fs_free_mem(&ctx.buf);
92 int (*func)(struct ext2_dir_entry *dirent,
100 static int xlate_func(ext2_ino_t dir EXT2FS_ATTR((unused)),
101 int entry EXT2FS_ATTR((unused)),
102 struct ext2_dir_entry *dirent, int offset,
103 int blocksize, char *buf, void *priv_data)
105 struct xlate *xl = (struct xlate *) priv_data;
107 return (*xl->func)(dirent, offset, blocksize, buf, xl->real_private);
110 extern errcode_t ext2fs_dir_iterate(ext2_filsys fs,
114 int (*func)(struct ext2_dir_entry *dirent,
123 xl.real_private = priv_data;
126 return ext2fs_dir_iterate2(fs, dir, flags, block_buf,
132 * Helper function which is private to this module. Used by
133 * ext2fs_dir_iterate() and ext2fs_dblist_dir_iterate()
135 int ext2fs_process_dir_block(ext2_filsys fs,
137 e2_blkcnt_t blockcnt,
138 blk_t ref_block EXT2FS_ATTR((unused)),
139 int ref_offset EXT2FS_ATTR((unused)),
142 struct dir_context *ctx = (struct dir_context *) priv_data;
143 unsigned int offset = 0;
144 unsigned int next_real_entry = 0;
149 struct ext2_dir_entry *dirent;
154 entry = blockcnt ? DIRENT_OTHER_FILE : DIRENT_DOT_FILE;
156 ctx->errcode = ext2fs_read_dir_block(fs, *blocknr, ctx->buf);
160 while (offset < fs->blocksize) {
161 dirent = (struct ext2_dir_entry *) (ctx->buf + offset);
162 if (((offset + dirent->rec_len) > fs->blocksize) ||
163 (dirent->rec_len < 8) ||
164 ((dirent->rec_len % 4) != 0) ||
165 (((dirent->name_len & 0xFF)+8) > dirent->rec_len)) {
166 ctx->errcode = EXT2_ET_DIR_CORRUPTED;
169 if (!dirent->inode &&
170 !(ctx->flags & DIRENT_FLAG_INCLUDE_EMPTY))
173 ret = (ctx->func)(ctx->dir,
174 (next_real_entry > offset) ?
175 DIRENT_DELETED_FILE : entry,
177 fs->blocksize, ctx->buf,
179 if (entry < DIRENT_OTHER_FILE)
182 if (ret & DIRENT_CHANGED)
184 if (ret & DIRENT_ABORT) {
189 if (next_real_entry == offset)
190 next_real_entry += dirent->rec_len;
192 if (ctx->flags & DIRENT_FLAG_INCLUDE_REMOVED) {
193 size = ((dirent->name_len & 0xFF) + 11) & ~3;
195 if (dirent->rec_len != size) {
196 unsigned int final_offset;
198 final_offset = offset + dirent->rec_len;
200 while (offset < final_offset &&
201 !ext2fs_validate_entry(ctx->buf,
208 offset += dirent->rec_len;
212 ctx->errcode = ext2fs_write_dir_block(fs, *blocknr, ctx->buf);