bmove.c revision ee01079a17bfecd17292ccd60058056fb3a8ba6c 
1/*
2 * bmove.c --- Move blocks around to make way for a particular
3 * 	filesystem structure.
4 *
5 * Copyright (C) 1997 Theodore Ts'o.  This file may be redistributed
6 * under the terms of the GNU Public License.
7 */
8
9#include <stdio.h>
10#include <string.h>
11#if HAVE_UNISTD_H
12#include <unistd.h>
13#endif
14#if HAVE_SYS_TYPES_H
15#include <sys/types.h>
16#endif
17#if HAVE_SYS_TIME_H
18#include <sys/time.h>
19#endif
20
21#include "ext2_fs.h"
22#include "ext2fsP.h"
23
24struct process_block_struct {
25	ext2_ino_t		ino;
26	struct ext2_inode *	inode;
27	ext2fs_block_bitmap	reserve;
28	ext2fs_block_bitmap	alloc_map;
29	errcode_t		error;
30	char			*buf;
31	int			add_dir;
32	int			flags;
33};
34
35static int process_block(ext2_filsys fs, blk_t	*block_nr,
36			 e2_blkcnt_t blockcnt, blk_t ref_block,
37			 int ref_offset, void *priv_data)
38{
39	struct process_block_struct *pb;
40	errcode_t	retval;
41	int		ret;
42	blk_t		block, orig;
43
44	pb = (struct process_block_struct *) priv_data;
45	block = orig = *block_nr;
46	ret = 0;
47
48	/*
49	 * Let's see if this is one which we need to relocate
50	 */
51	if (ext2fs_test_block_bitmap(pb->reserve, block)) {
52		do {
53			if (++block >= fs->super->s_blocks_count)
54				block = fs->super->s_first_data_block;
55			if (block == orig) {
56				pb->error = EXT2_ET_BLOCK_ALLOC_FAIL;
57				return BLOCK_ABORT;
58			}
59		} while (ext2fs_test_block_bitmap(pb->reserve, block) ||
60			 ext2fs_test_block_bitmap(pb->alloc_map, block));
61
62		retval = io_channel_read_blk(fs->io, orig, 1, pb->buf);
63		if (retval) {
64			pb->error = retval;
65			return BLOCK_ABORT;
66		}
67		retval = io_channel_write_blk(fs->io, block, 1, pb->buf);
68		if (retval) {
69			pb->error = retval;
70			return BLOCK_ABORT;
71		}
72		*block_nr = block;
73		ext2fs_mark_block_bitmap(pb->alloc_map, block);
74		ret = BLOCK_CHANGED;
75		if (pb->flags & EXT2_BMOVE_DEBUG)
76			printf("ino=%ld, blockcnt=%lld, %u->%u\n", pb->ino,
77			       blockcnt, orig, block);
78	}
79	if (pb->add_dir) {
80		retval = ext2fs_add_dir_block(fs->dblist, pb->ino,
81					      block, (int) blockcnt);
82		if (retval) {
83			pb->error = retval;
84			ret |= BLOCK_ABORT;
85		}
86	}
87	return ret;
88}
89
90errcode_t ext2fs_move_blocks(ext2_filsys fs,
91			     ext2fs_block_bitmap reserve,
92			     ext2fs_block_bitmap alloc_map,
93			     int flags)
94{
95	ext2_ino_t	ino;
96	struct ext2_inode inode;
97	errcode_t	retval;
98	struct process_block_struct pb;
99	ext2_inode_scan	scan;
100	char		*block_buf;
101
102	retval = ext2fs_open_inode_scan(fs, 0, &scan);
103	if (retval)
104		return retval;
105
106	pb.reserve = reserve;
107	pb.error = 0;
108	pb.alloc_map = alloc_map ? alloc_map : fs->block_map;
109	pb.flags = flags;
110
111	retval = ext2fs_get_array(4, fs->blocksize, &block_buf);
112	if (retval)
113		return retval;
114	pb.buf = block_buf + fs->blocksize * 3;
115
116	/*
117	 * If GET_DBLIST is set in the flags field, then we should
118	 * gather directory block information while we're doing the
119	 * block move.
120	 */
121	if (flags & EXT2_BMOVE_GET_DBLIST) {
122		if (fs->dblist) {
123			ext2fs_free_dblist(fs->dblist);
124			fs->dblist = NULL;
125		}
126		retval = ext2fs_init_dblist(fs, 0);
127		if (retval)
128			return retval;
129	}
130
131	retval = ext2fs_get_next_inode(scan, &ino, &inode);
132	if (retval)
133		return retval;
134
135	while (ino) {
136		if ((inode.i_links_count == 0) ||
137		    !ext2fs_inode_has_valid_blocks(&inode))
138			goto next;
139
140		pb.ino = ino;
141		pb.inode = &inode;
142
143		pb.add_dir = (LINUX_S_ISDIR(inode.i_mode) &&
144			      flags & EXT2_BMOVE_GET_DBLIST);
145
146		retval = ext2fs_block_iterate2(fs, ino, 0, block_buf,
147					      process_block, &pb);
148		if (retval)
149			return retval;
150		if (pb.error)
151			return pb.error;
152
153	next:
154		retval = ext2fs_get_next_inode(scan, &ino, &inode);
155		if (retval == EXT2_ET_BAD_BLOCK_IN_INODE_TABLE)
156			goto next;
157	}
158	return 0;
159}
160
161