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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 "config.h"
14 #include <stdio.h>
15 #include <string.h>
16 #if HAVE_UNISTD_H
17 #include <unistd.h>
18 #endif
19 #if HAVE_SYS_TYPES_H
20 #include <sys/types.h>
21 #endif
22 #if HAVE_SYS_TIME_H
23 #include <sys/time.h>
24 #endif
25 
26 #include "ext2_fs.h"
27 #include "ext2fsP.h"
28 
29 struct process_block_struct {
30 	ext2_ino_t		ino;
31 	struct ext2_inode *	inode;
32 	ext2fs_block_bitmap	reserve;
33 	ext2fs_block_bitmap	alloc_map;
34 	errcode_t		error;
35 	char			*buf;
36 	int			add_dir;
37 	int			flags;
38 };
39 
process_block(ext2_filsys fs,blk64_t * block_nr,e2_blkcnt_t blockcnt,blk64_t ref_block,int ref_offset,void * priv_data)40 static int process_block(ext2_filsys fs, blk64_t *block_nr,
41 			 e2_blkcnt_t blockcnt, blk64_t ref_block,
42 			 int ref_offset, void *priv_data)
43 {
44 	struct process_block_struct *pb;
45 	errcode_t	retval;
46 	int		ret;
47 	blk64_t		block, orig;
48 
49 	pb = (struct process_block_struct *) priv_data;
50 	block = orig = *block_nr;
51 	ret = 0;
52 
53 	/*
54 	 * Let's see if this is one which we need to relocate
55 	 */
56 	if (ext2fs_test_block_bitmap2(pb->reserve, block)) {
57 		do {
58 			if (++block >= ext2fs_blocks_count(fs->super))
59 				block = fs->super->s_first_data_block;
60 			if (block == orig) {
61 				pb->error = EXT2_ET_BLOCK_ALLOC_FAIL;
62 				return BLOCK_ABORT;
63 			}
64 		} while (ext2fs_test_block_bitmap2(pb->reserve, block) ||
65 			 ext2fs_test_block_bitmap2(pb->alloc_map, block));
66 
67 		retval = io_channel_read_blk64(fs->io, orig, 1, pb->buf);
68 		if (retval) {
69 			pb->error = retval;
70 			return BLOCK_ABORT;
71 		}
72 		retval = io_channel_write_blk64(fs->io, block, 1, pb->buf);
73 		if (retval) {
74 			pb->error = retval;
75 			return BLOCK_ABORT;
76 		}
77 		*block_nr = block;
78 		ext2fs_mark_block_bitmap2(pb->alloc_map, block);
79 		ret = BLOCK_CHANGED;
80 		if (pb->flags & EXT2_BMOVE_DEBUG)
81 			printf("ino=%u, blockcnt=%lld, %llu->%llu\n",
82 			       (unsigned) pb->ino, blockcnt,
83 			       (unsigned long long) orig,
84 			       (unsigned long long) block);
85 	}
86 	if (pb->add_dir) {
87 		retval = ext2fs_add_dir_block2(fs->dblist, pb->ino,
88 					       block, blockcnt);
89 		if (retval) {
90 			pb->error = retval;
91 			ret |= BLOCK_ABORT;
92 		}
93 	}
94 	return ret;
95 }
96 
ext2fs_move_blocks(ext2_filsys fs,ext2fs_block_bitmap reserve,ext2fs_block_bitmap alloc_map,int flags)97 errcode_t ext2fs_move_blocks(ext2_filsys fs,
98 			     ext2fs_block_bitmap reserve,
99 			     ext2fs_block_bitmap alloc_map,
100 			     int flags)
101 {
102 	ext2_ino_t	ino;
103 	struct ext2_inode inode;
104 	errcode_t	retval;
105 	struct process_block_struct pb;
106 	ext2_inode_scan	scan;
107 	char		*block_buf;
108 
109 	retval = ext2fs_open_inode_scan(fs, 0, &scan);
110 	if (retval)
111 		return retval;
112 
113 	pb.reserve = reserve;
114 	pb.error = 0;
115 	pb.alloc_map = alloc_map ? alloc_map : fs->block_map;
116 	pb.flags = flags;
117 
118 	retval = ext2fs_get_array(4, fs->blocksize, &block_buf);
119 	if (retval)
120 		return retval;
121 	pb.buf = block_buf + fs->blocksize * 3;
122 
123 	/*
124 	 * If GET_DBLIST is set in the flags field, then we should
125 	 * gather directory block information while we're doing the
126 	 * block move.
127 	 */
128 	if (flags & EXT2_BMOVE_GET_DBLIST) {
129 		if (fs->dblist) {
130 			ext2fs_free_dblist(fs->dblist);
131 			fs->dblist = NULL;
132 		}
133 		retval = ext2fs_init_dblist(fs, 0);
134 		if (retval)
135 			return retval;
136 	}
137 
138 	retval = ext2fs_get_next_inode(scan, &ino, &inode);
139 	if (retval)
140 		return retval;
141 
142 	while (ino) {
143 		if ((inode.i_links_count == 0) ||
144 		    !ext2fs_inode_has_valid_blocks2(fs, &inode))
145 			goto next;
146 
147 		pb.ino = ino;
148 		pb.inode = &inode;
149 
150 		pb.add_dir = (LINUX_S_ISDIR(inode.i_mode) &&
151 			      flags & EXT2_BMOVE_GET_DBLIST);
152 
153 		retval = ext2fs_block_iterate3(fs, ino, 0, block_buf,
154 					       process_block, &pb);
155 		if (retval)
156 			return retval;
157 		if (pb.error)
158 			return pb.error;
159 
160 	next:
161 		retval = ext2fs_get_next_inode(scan, &ino, &inode);
162 		if (retval == EXT2_ET_BAD_BLOCK_IN_INODE_TABLE)
163 			goto next;
164 	}
165 	return 0;
166 }
167 
168