expanddir.c revision 8bd0c95908baa3af706b9e731daff9472bec74c9 
1/*
2 * expand.c --- expand an ext2fs directory
3 *
4 * Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999  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
18#include "ext2_fs.h"
19#include "ext2fs.h"
20
21struct expand_dir_struct {
22	int		done;
23	int		newblocks;
24	errcode_t	err;
25};
26
27static int expand_dir_proc(ext2_filsys		fs,
28			   blk_t		*blocknr,
29			   e2_blkcnt_t		blockcnt,
30			   blk_t		ref_block,
31			   int			ref_offset,
32			   void			*priv_data)
33{
34	struct expand_dir_struct *es = (struct expand_dir_struct *) priv_data;
35	blk_t	new_blk;
36	static blk_t	last_blk = 0;
37	char		*block;
38	errcode_t	retval;
39
40	if (*blocknr) {
41		last_blk = *blocknr;
42		return 0;
43	}
44	retval = ext2fs_new_block(fs, last_blk, 0, &new_blk);
45	if (retval) {
46		es->err = retval;
47		return BLOCK_ABORT;
48	}
49	if (blockcnt > 0) {
50		retval = ext2fs_new_dir_block(fs, 0, 0, &block);
51		if (retval) {
52			es->err = retval;
53			return BLOCK_ABORT;
54		}
55		es->done = 1;
56		retval = ext2fs_write_dir_block(fs, new_blk, block);
57	} else {
58		retval = ext2fs_get_mem(fs->blocksize, (void **) &block);
59		if (retval) {
60			es->err = retval;
61			return BLOCK_ABORT;
62		}
63		memset(block, 0, fs->blocksize);
64		retval = io_channel_write_blk(fs->io, new_blk, 1, block);
65	}
66	if (retval) {
67		es->err = retval;
68		return BLOCK_ABORT;
69	}
70	ext2fs_free_mem((void **) &block);
71	*blocknr = new_blk;
72	ext2fs_block_alloc_stats(fs, new_blk, +1);
73	es->newblocks++;
74
75	if (es->done)
76		return (BLOCK_CHANGED | BLOCK_ABORT);
77	else
78		return BLOCK_CHANGED;
79}
80
81errcode_t ext2fs_expand_dir(ext2_filsys fs, ext2_ino_t dir)
82{
83	errcode_t	retval;
84	struct expand_dir_struct es;
85	struct ext2_inode	inode;
86
87	EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
88
89	if (!(fs->flags & EXT2_FLAG_RW))
90		return EXT2_ET_RO_FILSYS;
91
92	if (!fs->block_map)
93		return EXT2_ET_NO_BLOCK_BITMAP;
94
95	retval = ext2fs_check_directory(fs, dir);
96	if (retval)
97		return retval;
98
99	es.done = 0;
100	es.err = 0;
101	es.newblocks = 0;
102
103	retval = ext2fs_block_iterate2(fs, dir, BLOCK_FLAG_APPEND,
104				       0, expand_dir_proc, &es);
105
106	if (es.err)
107		return es.err;
108	if (!es.done)
109		return EXT2_ET_EXPAND_DIR_ERR;
110
111	/*
112	 * Update the size and block count fields in the inode.
113	 */
114	retval = ext2fs_read_inode(fs, dir, &inode);
115	if (retval)
116		return retval;
117
118	inode.i_size += fs->blocksize;
119	inode.i_blocks += (fs->blocksize / 512) * es.newblocks;
120
121	retval = ext2fs_write_inode(fs, dir, &inode);
122	if (retval)
123		return retval;
124
125	return 0;
126}
127