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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.  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 
24 struct 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 
process_block(ext2_filsys fs,blk_t * block_nr,e2_blkcnt_t blockcnt,blk_t ref_block,int ref_offset,void * priv_data)35 static 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 
ext2fs_move_blocks(ext2_filsys fs,ext2fs_block_bitmap reserve,ext2fs_block_bitmap alloc_map,int flags)90 errcode_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