dir_iterate.c revision 31dbecd482405e0d3a67eb58e1a1c8cb9f2ad83e 
1/*
2 * dir_iterate.c --- ext2fs directory iteration operations
3 *
4 * Copyright (C) 1993, 1994, 1994, 1995, 1996, 1997 Theodore Ts'o.
5 *
6 * %Begin-Header%
7 * This file may be redistributed under the terms of the GNU Public
8 * License.
9 * %End-Header%
10 */
11
12#include <stdio.h>
13#include <string.h>
14#if HAVE_UNISTD_H
15#include <unistd.h>
16#endif
17#if HAVE_ERRNO_H
18#include <errno.h>
19#endif
20
21#if EXT2_FLAT_INCLUDES
22#include "ext2_fs.h"
23#else
24#include <linux/ext2_fs.h>
25#endif
26
27#include "ext2fsP.h"
28
29errcode_t ext2fs_dir_iterate(ext2_filsys fs,
30			     ext2_ino_t dir,
31			     int flags,
32			     char *block_buf,
33			     int (*func)(struct ext2_dir_entry *dirent,
34					 int	offset,
35					 int	blocksize,
36					 char	*buf,
37					 void	*priv_data),
38			     void *priv_data)
39{
40	struct		dir_context	ctx;
41	errcode_t	retval;
42
43	EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
44
45	retval = ext2fs_check_directory(fs, dir);
46	if (retval)
47		return retval;
48
49	ctx.dir = dir;
50	ctx.flags = flags;
51	if (block_buf)
52		ctx.buf = block_buf;
53	else {
54		retval = ext2fs_get_mem(fs->blocksize, (void **) &ctx.buf);
55		if (retval)
56			return retval;
57	}
58	ctx.func = func;
59	ctx.func2 = 0;
60	ctx.priv_data = priv_data;
61	ctx.errcode = 0;
62	retval = ext2fs_block_iterate2(fs, dir, 0, 0,
63				       ext2fs_process_dir_block, &ctx);
64	if (!block_buf)
65		ext2fs_free_mem((void **) &ctx.buf);
66	if (retval)
67		return retval;
68	return ctx.errcode;
69}
70
71/*
72 * Helper function which is private to this module.  Used by
73 * ext2fs_dir_iterate() and ext2fs_dblist_dir_iterate()
74 */
75int ext2fs_process_dir_block(ext2_filsys  	fs,
76			     blk_t		*blocknr,
77			     e2_blkcnt_t		blockcnt,
78			     blk_t		ref_block,
79			     int			ref_offset,
80			     void		*priv_data)
81{
82	struct dir_context *ctx = (struct dir_context *) priv_data;
83	int		offset = 0;
84	int		ret = 0;
85	int		changed = 0;
86	int		do_abort = 0;
87	int		entry;
88	struct ext2_dir_entry *dirent;
89
90	if (blockcnt < 0)
91		return 0;
92
93	entry = blockcnt ? DIRENT_OTHER_FILE : DIRENT_DOT_FILE;
94
95	ctx->errcode = ext2fs_read_dir_block(fs, *blocknr, ctx->buf);
96	if (ctx->errcode)
97		return BLOCK_ABORT;
98
99	while (offset < fs->blocksize) {
100		dirent = (struct ext2_dir_entry *) (ctx->buf + offset);
101		if (((offset + dirent->rec_len) > fs->blocksize) ||
102		    (dirent->rec_len < 8) ||
103		    (((dirent->name_len & 0xFF)+8) > dirent->rec_len)) {
104			ctx->errcode = EXT2_ET_DIR_CORRUPTED;
105			return BLOCK_ABORT;
106		}
107		if (!dirent->inode &&
108		    !(ctx->flags & DIRENT_FLAG_INCLUDE_EMPTY))
109			goto next;
110
111		if (ctx->func)
112			ret = (ctx->func)(dirent, offset, fs->blocksize,
113					  ctx->buf, ctx->priv_data);
114		else if (ctx->func2) {
115			ret = (ctx->func2)(ctx->dir, entry, dirent, offset,
116					   fs->blocksize, ctx->buf,
117					   ctx->priv_data);
118			if (entry < DIRENT_OTHER_FILE)
119				entry++;
120		}
121
122		if (ret & DIRENT_CHANGED)
123			changed++;
124		if (ret & DIRENT_ABORT) {
125			do_abort++;
126			break;
127		}
128next:
129		offset += dirent->rec_len;
130	}
131
132	if (changed) {
133		ctx->errcode = ext2fs_write_dir_block(fs, *blocknr, ctx->buf);
134		if (ctx->errcode)
135			return BLOCK_ABORT;
136	}
137	if (do_abort)
138		return BLOCK_ABORT;
139	return 0;
140}
141
142