dir_iterate.c revision c555aebde40afdc0d15d674f2c81c0e05cfded3f 
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#include <stdlib.h>
18#if HAVE_ERRNO_H
19#include <errno.h>
20#endif
21
22#include <linux/ext2_fs.h>
23
24#include "ext2fsP.h"
25
26errcode_t ext2fs_dir_iterate(ext2_filsys fs,
27			     ino_t dir,
28			     int flags,
29			     char *block_buf,
30			     int (*func)(struct ext2_dir_entry *dirent,
31					 int	offset,
32					 int	blocksize,
33					 char	*buf,
34					 void	*private),
35			     void *private)
36{
37	struct		dir_context	ctx;
38	errcode_t	retval;
39
40	EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
41
42	retval = ext2fs_check_directory(fs, dir);
43	if (retval)
44		return retval;
45
46	ctx.dir = dir;
47	ctx.flags = flags;
48	if (block_buf)
49		ctx.buf = block_buf;
50	else {
51		ctx.buf = malloc(fs->blocksize);
52		if (!ctx.buf)
53			return EXT2_NO_MEMORY;
54	}
55	ctx.func = func;
56	ctx.func2 = 0;
57	ctx.private = private;
58	ctx.errcode = 0;
59	retval = ext2fs_block_iterate(fs, dir, 0, 0,
60				      ext2fs_process_dir_block, &ctx);
61	if (!block_buf)
62		free(ctx.buf);
63	if (retval)
64		return retval;
65	return ctx.errcode;
66}
67
68/*
69 * Helper function which is private to this module.  Used by
70 * ext2fs_dir_iterate() and ext2fs_dblist_dir_iterate()
71 */
72extern int ext2fs_process_dir_block(ext2_filsys  	fs,
73				    blk_t		*blocknr,
74				    int		blockcnt,
75				    void		*private)
76{
77	struct dir_context *ctx = (struct dir_context *) private;
78	int		offset = 0;
79	int		ret = 0;
80	int		changed = 0;
81	int		do_abort = 0;
82	int		entry;
83	struct ext2_dir_entry *dirent;
84
85	if (blockcnt < 0)
86		return 0;
87
88	ctx->errcode = ext2fs_read_dir_block(fs, *blocknr, ctx->buf);
89	if (ctx->errcode)
90		return BLOCK_ABORT;
91
92	entry = blockcnt ? DIRENT_OTHER_FILE : DIRENT_DOT_FILE;
93
94	while (offset < fs->blocksize) {
95		dirent = (struct ext2_dir_entry *) (ctx->buf + offset);
96		if (!dirent->inode &&
97		    !(ctx->flags & DIRENT_FLAG_INCLUDE_EMPTY))
98			goto next;
99
100		if (ctx->func)
101			ret = (ctx->func)(dirent, offset, fs->blocksize,
102					  ctx->buf, ctx->private);
103		else if (ctx->func2) {
104			ret = (ctx->func2)(ctx->dir, entry, dirent, offset,
105					   fs->blocksize, ctx->buf,
106					   ctx->private);
107			if (entry < DIRENT_OTHER_FILE)
108				entry++;
109		}
110
111		if (ret & DIRENT_CHANGED)
112			changed++;
113		if (ret & DIRENT_ABORT) {
114			do_abort++;
115			break;
116		}
117next:
118		if (((offset + dirent->rec_len) > fs->blocksize) ||
119		    (dirent->rec_len < 8) ||
120		    ((dirent->name_len+8) > dirent->rec_len)) {
121			ctx->errcode = EXT2_ET_DIR_CORRUPTED;
122			return BLOCK_ABORT;
123		}
124		offset += dirent->rec_len;
125	}
126
127	if (changed) {
128		ctx->errcode = ext2fs_write_dir_block(fs, *blocknr, ctx->buf);
129		if (ctx->errcode)
130			return BLOCK_ABORT;
131	}
132	if (do_abort)
133		return BLOCK_ABORT;
134	return 0;
135}
136
137