bmove.c revision a6ce1349539f866334ef3d5758bc2ee44a454acd 
1/*
2 * bmove.c --- Move blocks around to make way for a particular
3 * 	filesystem structure.
4 *
5 * Copyright (C) 1997 Theodore Ts'o.
6 *
7 * %Begin-Header%
8 * This file may be redistributed under the terms of the GNU Library
9 * General Public License, version 2.
10 * %End-Header%
11 */
12
13#include <stdio.h>
14#include <string.h>
15#if HAVE_UNISTD_H
16#include <unistd.h>
17#endif
18#if HAVE_SYS_TYPES_H
19#include <sys/types.h>
20#endif
21#if HAVE_SYS_TIME_H
22#include <sys/time.h>
23#endif
24
25#include "ext2_fs.h"
26#include "ext2fsP.h"
27
28struct process_block_struct {
29	ext2_ino_t		ino;
30	struct ext2_inode *	inode;
31	ext2fs_block_bitmap	reserve;
32	ext2fs_block_bitmap	alloc_map;
33	errcode_t		error;
34	char			*buf;
35	int			add_dir;
36	int			flags;
37};
38
39static int process_block(ext2_filsys fs, blk_t	*block_nr,
40			 e2_blkcnt_t blockcnt, blk_t ref_block,
41			 int ref_offset, void *priv_data)
42{
43	struct process_block_struct *pb;
44	errcode_t	retval;
45	int		ret;
46	blk_t		block, orig;
47
48	pb = (struct process_block_struct *) priv_data;
49	block = orig = *block_nr;
50	ret = 0;
51
52	/*
53	 * Let's see if this is one which we need to relocate
54	 */
55	if (ext2fs_test_block_bitmap(pb->reserve, block)) {
56		do {
57			if (++block >= fs->super->s_blocks_count)
58				block = fs->super->s_first_data_block;
59			if (block == orig) {
60				pb->error = EXT2_ET_BLOCK_ALLOC_FAIL;
61				return BLOCK_ABORT;
62			}
63		} while (ext2fs_test_block_bitmap(pb->reserve, block) ||
64			 ext2fs_test_block_bitmap(pb->alloc_map, block));
65
66		retval = io_channel_read_blk(fs->io, orig, 1, pb->buf);
67		if (retval) {
68			pb->error = retval;
69			return BLOCK_ABORT;
70		}
71		retval = io_channel_write_blk(fs->io, block, 1, pb->buf);
72		if (retval) {
73			pb->error = retval;
74			return BLOCK_ABORT;
75		}
76		*block_nr = block;
77		ext2fs_mark_block_bitmap(pb->alloc_map, block);
78		ret = BLOCK_CHANGED;
79		if (pb->flags & EXT2_BMOVE_DEBUG)
80			printf("ino=%ld, blockcnt=%lld, %u->%u\n", pb->ino,
81			       blockcnt, orig, block);
82	}
83	if (pb->add_dir) {
84		retval = ext2fs_add_dir_block(fs->dblist, pb->ino,
85					      block, (int) blockcnt);
86		if (retval) {
87			pb->error = retval;
88			ret |= BLOCK_ABORT;
89		}
90	}
91	return ret;
92}
93
94errcode_t ext2fs_move_blocks(ext2_filsys fs,
95			     ext2fs_block_bitmap reserve,
96			     ext2fs_block_bitmap alloc_map,
97			     int flags)
98{
99	ext2_ino_t	ino;
100	struct ext2_inode inode;
101	errcode_t	retval;
102	struct process_block_struct pb;
103	ext2_inode_scan	scan;
104	char		*block_buf;
105
106	retval = ext2fs_open_inode_scan(fs, 0, &scan);
107	if (retval)
108		return retval;
109
110	pb.reserve = reserve;
111	pb.error = 0;
112	pb.alloc_map = alloc_map ? alloc_map : fs->block_map;
113	pb.flags = flags;
114
115	retval = ext2fs_get_array(4, fs->blocksize, &block_buf);
116	if (retval)
117		return retval;
118	pb.buf = block_buf + fs->blocksize * 3;
119
120	/*
121	 * If GET_DBLIST is set in the flags field, then we should
122	 * gather directory block information while we're doing the
123	 * block move.
124	 */
125	if (flags & EXT2_BMOVE_GET_DBLIST) {
126		if (fs->dblist) {
127			ext2fs_free_dblist(fs->dblist);
128			fs->dblist = NULL;
129		}
130		retval = ext2fs_init_dblist(fs, 0);
131		if (retval)
132			return retval;
133	}
134
135	retval = ext2fs_get_next_inode(scan, &ino, &inode);
136	if (retval)
137		return retval;
138
139	while (ino) {
140		if ((inode.i_links_count == 0) ||
141		    !ext2fs_inode_has_valid_blocks(&inode))
142			goto next;
143
144		pb.ino = ino;
145		pb.inode = &inode;
146
147		pb.add_dir = (LINUX_S_ISDIR(inode.i_mode) &&
148			      flags & EXT2_BMOVE_GET_DBLIST);
149
150		retval = ext2fs_block_iterate2(fs, ino, 0, block_buf,
151					      process_block, &pb);
152		if (retval)
153			return retval;
154		if (pb.error)
155			return pb.error;
156
157	next:
158		retval = ext2fs_get_next_inode(scan, &ino, &inode);
159		if (retval == EXT2_ET_BAD_BLOCK_IN_INODE_TABLE)
160			goto next;
161	}
162	return 0;
163}
164
165