summaryrefslogtreecommitdiffstats
path: root/fs/reiserfs/resize.c
blob: 87ebd6ee65b72c14a194a651f49f81da4292ec19 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
/* 
 * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
 */
 
/* 
 * Written by Alexander Zarochentcev.
 *
 * The kernel part of the (on-line) reiserfs resizer.
 */

#ifdef __KERNEL__

#include <linux/kernel.h>
#include <linux/vmalloc.h>
#include <linux/locks.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/reiserfs_fs.h>
#include <linux/reiserfs_fs_sb.h>

#else

#include "nokernel.h"

#endif

int reiserfs_resize (struct super_block * s, unsigned long block_count_new)
{
	struct reiserfs_super_block * sb;
	struct buffer_head ** bitmap, * bh;
	struct reiserfs_transaction_handle th;
	unsigned int bmap_nr_new, bmap_nr;
	unsigned int block_r_new, block_r;
	
	struct reiserfs_list_bitmap * jb;
	struct reiserfs_list_bitmap jbitmap[JOURNAL_NUM_BITMAPS];
	
	unsigned long int block_count, free_blocks;
	int i;
	int copy_size ;

	sb = SB_DISK_SUPER_BLOCK(s);

	if (SB_BLOCK_COUNT(s) >= block_count_new) {
		printk("can\'t shrink filesystem on-line\n");
		return -EINVAL;
	}

	/* check the device size */
	bh = bread(s->s_dev, block_count_new - 1, s->s_blocksize);
	if (!bh) {
		printk("reiserfs_resize: can\'t read last block\n");
		return -EINVAL;
	}	
	bforget(bh);

	/* old disk layout detection; those partitions can be mounted, but
	 * cannot be resized */
	if (SB_BUFFER_WITH_SB(s)->b_blocknr *	SB_BUFFER_WITH_SB(s)->b_size 
		!= REISERFS_DISK_OFFSET_IN_BYTES ) {
		printk("reiserfs_resize: unable to resize a reiserfs without distributed bitmap (fs version < 3.5.12)\n");
		return -ENOTSUPP;
	}
       
	/* count used bits in last bitmap block */
	block_r = SB_BLOCK_COUNT(s) -
	        (SB_BMAP_NR(s) - 1) * s->s_blocksize * 8;
	
	/* count bitmap blocks in new fs */
	bmap_nr_new = block_count_new / ( s->s_blocksize * 8 );
	block_r_new = block_count_new - bmap_nr_new * s->s_blocksize * 8;
	if (block_r_new) 
		bmap_nr_new++;
	else
		block_r_new = s->s_blocksize * 8;

	/* save old values */
	block_count = SB_BLOCK_COUNT(s);
	bmap_nr     = SB_BMAP_NR(s);

	/* resizing of reiserfs bitmaps (journal and real), if needed */
	if (bmap_nr_new > bmap_nr) {	    
	    /* reallocate journal bitmaps */
	    if (reiserfs_allocate_list_bitmaps(s, jbitmap, bmap_nr_new) < 0) {
		printk("reiserfs_resize: unable to allocate memory for journal bitmaps\n");
		unlock_super(s) ;
		return -ENOMEM ;
	    }
	    /* the new journal bitmaps are zero filled, now we copy in the bitmap
	    ** node pointers from the old journal bitmap structs, and then
	    ** transfer the new data structures into the journal struct.
	    **
	    ** using the copy_size var below allows this code to work for
	    ** both shrinking and expanding the FS.
	    */
	    copy_size = bmap_nr_new < bmap_nr ? bmap_nr_new : bmap_nr ;
	    copy_size = copy_size * sizeof(struct reiserfs_list_bitmap_node *) ;
	    for (i = 0 ; i < JOURNAL_NUM_BITMAPS ; i++) {
		struct reiserfs_bitmap_node **node_tmp ;
		jb = SB_JOURNAL(s)->j_list_bitmap + i ;
		memcpy(jbitmap[i].bitmaps, jb->bitmaps, copy_size) ;

		/* just in case vfree schedules on us, copy the new
		** pointer into the journal struct before freeing the 
		** old one
		*/
		node_tmp = jb->bitmaps ;
		jb->bitmaps = jbitmap[i].bitmaps ;
		vfree(node_tmp) ;
	    }	
	
	    /* allocate additional bitmap blocks, reallocate array of bitmap
	     * block pointers */
	    bitmap = reiserfs_kmalloc(sizeof(struct buffer_head *) * bmap_nr_new, GFP_KERNEL, s);
	    if (!bitmap) {
		printk("reiserfs_resize: unable to allocate memory.\n");
		return -ENOMEM;
	    }
	    for (i = 0; i < bmap_nr; i++)
		bitmap[i] = SB_AP_BITMAP(s)[i];
	    for (i = bmap_nr; i < bmap_nr_new; i++) {
		bitmap[i] = reiserfs_getblk(s->s_dev, i * s->s_blocksize * 8, s->s_blocksize);
		memset(bitmap[i]->b_data, 0, sb->s_blocksize);
		reiserfs_test_and_set_le_bit(0, bitmap[i]->b_data);

		mark_buffer_dirty(bitmap[i]) ;
		mark_buffer_uptodate(bitmap[i], 1);
		ll_rw_block(WRITE, 1, bitmap + i);
		wait_on_buffer(bitmap[i]);
	    }	
	    /* free old bitmap blocks array */
	    reiserfs_kfree(SB_AP_BITMAP(s), 
			   sizeof(struct buffer_head *) * bmap_nr, s);
	    SB_AP_BITMAP(s) = bitmap;
	}
	
	/* begin transaction */
	journal_begin(&th, s, 10);

	/* correct last bitmap blocks in old and new disk layout */
	reiserfs_prepare_for_journal(s, SB_AP_BITMAP(s)[bmap_nr - 1], 1);
	for (i = block_r; i < s->s_blocksize * 8; i++)
	    reiserfs_test_and_clear_le_bit(i, 
					   SB_AP_BITMAP(s)[bmap_nr - 1]->b_data);
	journal_mark_dirty(&th, s, SB_AP_BITMAP(s)[bmap_nr - 1]);

	reiserfs_prepare_for_journal(s, SB_AP_BITMAP(s)[bmap_nr_new - 1], 1);
	for (i = block_r_new; i < s->s_blocksize * 8; i++)
	    reiserfs_test_and_set_le_bit(i,
					 SB_AP_BITMAP(s)[bmap_nr_new - 1]->b_data);
	journal_mark_dirty(&th, s, SB_AP_BITMAP(s)[bmap_nr_new - 1]);
 
 	/* update super */
	reiserfs_prepare_for_journal(s, SB_BUFFER_WITH_SB(s), 1) ;
	free_blocks = SB_FREE_BLOCKS(s);
	PUT_SB_FREE_BLOCKS(s, free_blocks + (block_count_new - block_count - (bmap_nr_new - bmap_nr)));
	PUT_SB_BLOCK_COUNT(s, block_count_new);
	PUT_SB_BMAP_NR(s, bmap_nr_new);
	s->s_dirt = 1;

	journal_mark_dirty(&th, s, SB_BUFFER_WITH_SB(s));
	
	SB_JOURNAL(s)->j_must_wait = 1;
	journal_end(&th, s, 10);

	return 0;
}