2 * dir_iterate.c --- ext2fs directory iteration operations
4 * Copyright (C) 1993, 1994, 1994, 1995, 1996, 1997 Theodore Ts'o.
7 * This file may be redistributed under the terms of the GNU Public
25 * This function checks to see whether or not a potential deleted
26 * directory entry looks valid. What we do is check the deleted entry
27 * and each successive entry to make sure that they all look valid and
28 * that the last deleted entry ends at the beginning of the next
29 * undeleted entry. Returns 1 if the deleted entry looks valid, zero
32 static int ext2fs_validate_entry(char *buf, int offset, int final_offset)
34 struct ext2_dir_entry *dirent;
36 while (offset < final_offset) {
37 dirent = (struct ext2_dir_entry *)(buf + offset);
38 offset += dirent->rec_len;
39 if ((dirent->rec_len < 8) ||
40 ((dirent->rec_len % 4) != 0) ||
41 (((dirent->name_len & 0xFF)+8) > dirent->rec_len))
44 return (offset == final_offset);
47 errcode_t ext2fs_dir_iterate2(ext2_filsys fs,
51 int (*func)(ext2_ino_t dir,
53 struct ext2_dir_entry *dirent,
60 struct dir_context ctx;
63 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
65 retval = ext2fs_check_directory(fs, dir);
74 retval = ext2fs_get_mem(fs->blocksize, &ctx.buf);
79 ctx.priv_data = priv_data;
81 retval = ext2fs_block_iterate2(fs, dir, 0, 0,
82 ext2fs_process_dir_block, &ctx);
84 ext2fs_free_mem(&ctx.buf);
91 int (*func)(struct ext2_dir_entry *dirent,
99 static int xlate_func(ext2_ino_t dir EXT2FS_ATTR((unused)),
100 int entry EXT2FS_ATTR((unused)),
101 struct ext2_dir_entry *dirent, int offset,
102 int blocksize, char *buf, void *priv_data)
104 struct xlate *xl = (struct xlate *) priv_data;
106 return (*xl->func)(dirent, offset, blocksize, buf, xl->real_private);
109 extern errcode_t ext2fs_dir_iterate(ext2_filsys fs,
113 int (*func)(struct ext2_dir_entry *dirent,
122 xl.real_private = priv_data;
125 return ext2fs_dir_iterate2(fs, dir, flags, block_buf,
131 * Helper function which is private to this module. Used by
132 * ext2fs_dir_iterate() and ext2fs_dblist_dir_iterate()
134 int ext2fs_process_dir_block(ext2_filsys fs,
136 e2_blkcnt_t blockcnt,
137 blk_t ref_block EXT2FS_ATTR((unused)),
138 int ref_offset EXT2FS_ATTR((unused)),
141 struct dir_context *ctx = (struct dir_context *) priv_data;
142 unsigned int offset = 0;
143 unsigned int next_real_entry = 0;
148 struct ext2_dir_entry *dirent;
153 entry = blockcnt ? DIRENT_OTHER_FILE : DIRENT_DOT_FILE;
155 ctx->errcode = ext2fs_read_dir_block(fs, *blocknr, ctx->buf);
159 while (offset < fs->blocksize) {
160 dirent = (struct ext2_dir_entry *) (ctx->buf + offset);
161 if (((offset + dirent->rec_len) > fs->blocksize) ||
162 (dirent->rec_len < 8) ||
163 ((dirent->rec_len % 4) != 0) ||
164 (((dirent->name_len & 0xFF)+8) > dirent->rec_len)) {
165 ctx->errcode = EXT2_ET_DIR_CORRUPTED;
168 if (!dirent->inode &&
169 !(ctx->flags & DIRENT_FLAG_INCLUDE_EMPTY))
172 ret = (ctx->func)(ctx->dir,
173 (next_real_entry > offset) ?
174 DIRENT_DELETED_FILE : entry,
176 fs->blocksize, ctx->buf,
178 if (entry < DIRENT_OTHER_FILE)
181 if (ret & DIRENT_CHANGED)
183 if (ret & DIRENT_ABORT) {
188 if (next_real_entry == offset)
189 next_real_entry += dirent->rec_len;
191 if (ctx->flags & DIRENT_FLAG_INCLUDE_REMOVED) {
192 size = ((dirent->name_len & 0xFF) + 11) & ~3;
194 if (dirent->rec_len != size) {
195 unsigned int final_offset;
197 final_offset = offset + dirent->rec_len;
199 while (offset < final_offset &&
200 !ext2fs_validate_entry(ctx->buf,
207 offset += dirent->rec_len;
211 ctx->errcode = ext2fs_write_dir_block(fs, *blocknr, ctx->buf);