1 /*
2 * Copyright 2000-2002 by Hans Reiser, licensing governed by reiserfs/README
3 */
4
5 /*
6 * Written by Alexander Zarochentcev.
7 *
8 * The kernel part of the (on-line) reiserfs resizer.
9 */
10
11 #include <linux/kernel.h>
12 #include <linux/vmalloc.h>
13 #include <linux/locks.h>
14 #include <linux/string.h>
15 #include <linux/errno.h>
16 #include <linux/reiserfs_fs.h>
17 #include <linux/reiserfs_fs_sb.h>
18
reiserfs_resize(struct super_block * s,unsigned long block_count_new)19 int reiserfs_resize (struct super_block * s, unsigned long block_count_new)
20 {
21 struct reiserfs_super_block * sb;
22 struct reiserfs_bitmap_info *bitmap;
23 struct buffer_head * bh;
24 struct reiserfs_transaction_handle th;
25 unsigned int bmap_nr_new, bmap_nr;
26 unsigned int block_r_new, block_r;
27
28 struct reiserfs_list_bitmap * jb;
29 struct reiserfs_list_bitmap jbitmap[JOURNAL_NUM_BITMAPS];
30
31 unsigned long int block_count, free_blocks;
32 int i;
33 int copy_size ;
34
35 sb = SB_DISK_SUPER_BLOCK(s);
36
37 if (SB_BLOCK_COUNT(s) >= block_count_new) {
38 reiserfs_warning(s, "can\'t shrink filesystem on-line\n");
39 return -EINVAL;
40 }
41
42 /* check the device size */
43 bh = sb_bread(s, block_count_new - 1);
44 if (!bh) {
45 reiserfs_warning(s, "reiserfs_resize: can\'t read last block\n");
46 return -EINVAL;
47 }
48 bforget(bh);
49
50 /* old disk layout detection; those partitions can be mounted, but
51 * cannot be resized */
52 if (SB_BUFFER_WITH_SB(s)->b_blocknr * SB_BUFFER_WITH_SB(s)->b_size
53 != REISERFS_DISK_OFFSET_IN_BYTES ) {
54 reiserfs_warning(s, "reiserfs_resize: unable to resize a reiserfs without distributed bitmap (fs version < 3.5.12)\n");
55 return -ENOTSUPP;
56 }
57
58 /* count used bits in last bitmap block */
59 block_r = SB_BLOCK_COUNT(s) -
60 (SB_BMAP_NR(s) - 1) * s->s_blocksize * 8;
61
62 /* count bitmap blocks in new fs */
63 bmap_nr_new = block_count_new / ( s->s_blocksize * 8 );
64 block_r_new = block_count_new - bmap_nr_new * s->s_blocksize * 8;
65 if (block_r_new)
66 bmap_nr_new++;
67 else
68 block_r_new = s->s_blocksize * 8;
69
70 /* save old values */
71 block_count = SB_BLOCK_COUNT(s);
72 bmap_nr = SB_BMAP_NR(s);
73
74 /* resizing of reiserfs bitmaps (journal and real), if needed */
75 if (bmap_nr_new > bmap_nr) {
76 /* reallocate journal bitmaps */
77 if (reiserfs_allocate_list_bitmaps(s, jbitmap, bmap_nr_new) < 0) {
78 reiserfs_warning(s, "reiserfs_resize: unable to allocate memory for journal bitmaps\n");
79 unlock_super(s) ;
80 return -ENOMEM ;
81 }
82 /* the new journal bitmaps are zero filled, now we copy in the bitmap
83 ** node pointers from the old journal bitmap structs, and then
84 ** transfer the new data structures into the journal struct.
85 **
86 ** using the copy_size var below allows this code to work for
87 ** both shrinking and expanding the FS.
88 */
89 copy_size = bmap_nr_new < bmap_nr ? bmap_nr_new : bmap_nr ;
90 copy_size = copy_size * sizeof(struct reiserfs_list_bitmap_node *) ;
91 for (i = 0 ; i < JOURNAL_NUM_BITMAPS ; i++) {
92 struct reiserfs_bitmap_node **node_tmp ;
93 jb = SB_JOURNAL(s)->j_list_bitmap + i ;
94 memcpy(jbitmap[i].bitmaps, jb->bitmaps, copy_size) ;
95
96 /* just in case vfree schedules on us, copy the new
97 ** pointer into the journal struct before freeing the
98 ** old one
99 */
100 node_tmp = jb->bitmaps ;
101 jb->bitmaps = jbitmap[i].bitmaps ;
102 vfree(node_tmp) ;
103 }
104
105 /* allocate additional bitmap blocks, reallocate array of bitmap
106 * block pointers */
107 bitmap = vmalloc(sizeof(struct reiserfs_bitmap_info) * bmap_nr_new);
108 if (!bitmap) {
109 reiserfs_warning(s, "reiserfs_resize: unable to allocate memory.\n");
110 return -ENOMEM;
111 }
112 for (i = 0; i < bmap_nr; i++)
113 bitmap[i] = SB_AP_BITMAP(s)[i];
114 for (i = bmap_nr; i < bmap_nr_new; i++) {
115 bitmap[i].bh = sb_getblk(s, i * s->s_blocksize * 8);
116 memset(bitmap[i].bh->b_data, 0, sb_blocksize(sb));
117 reiserfs_test_and_set_le_bit(0, bitmap[i].bh->b_data);
118
119 mark_buffer_dirty(bitmap[i].bh) ;
120 mark_buffer_uptodate(bitmap[i].bh, 1);
121 ll_rw_block(WRITE, 1, &bitmap[i].bh);
122 wait_on_buffer(bitmap[i].bh);
123 bitmap[i].first_zero_hint=1;
124 bitmap[i].free_count = s->s_blocksize * 8 - 1;
125 }
126 /* free old bitmap blocks array */
127 vfree(SB_AP_BITMAP(s));
128
129 SB_AP_BITMAP(s) = bitmap;
130 }
131
132 /* begin transaction */
133 journal_begin(&th, s, 10);
134
135 /* correct last bitmap blocks in old and new disk layout */
136 reiserfs_prepare_for_journal(s, SB_AP_BITMAP(s)[bmap_nr - 1].bh, 1);
137 for (i = block_r; i < s->s_blocksize * 8; i++)
138 reiserfs_test_and_clear_le_bit(i,
139 SB_AP_BITMAP(s)[bmap_nr - 1].bh->b_data);
140 SB_AP_BITMAP(s)[bmap_nr - 1].free_count += s->s_blocksize * 8 - block_r;
141 if ( !SB_AP_BITMAP(s)[bmap_nr - 1].first_zero_hint)
142 SB_AP_BITMAP(s)[bmap_nr - 1].first_zero_hint = block_r;
143 journal_mark_dirty(&th, s, SB_AP_BITMAP(s)[bmap_nr - 1].bh);
144
145 reiserfs_prepare_for_journal(s, SB_AP_BITMAP(s)[bmap_nr_new - 1].bh, 1);
146 for (i = block_r_new; i < s->s_blocksize * 8; i++)
147 reiserfs_test_and_set_le_bit(i,
148 SB_AP_BITMAP(s)[bmap_nr_new - 1].bh->b_data);
149 journal_mark_dirty(&th, s, SB_AP_BITMAP(s)[bmap_nr_new - 1].bh);
150
151 SB_AP_BITMAP(s)[bmap_nr_new - 1].free_count -= s->s_blocksize * 8 - block_r_new;
152 /* Extreme case where last bitmap is the only valid block in itself. */
153 if ( !SB_AP_BITMAP(s)[bmap_nr_new - 1].free_count )
154 SB_AP_BITMAP(s)[bmap_nr_new - 1].first_zero_hint = 0;
155 /* update super */
156 reiserfs_prepare_for_journal(s, SB_BUFFER_WITH_SB(s), 1) ;
157 free_blocks = SB_FREE_BLOCKS(s);
158 PUT_SB_FREE_BLOCKS(s, free_blocks + (block_count_new - block_count - (bmap_nr_new - bmap_nr)));
159 PUT_SB_BLOCK_COUNT(s, block_count_new);
160 PUT_SB_BMAP_NR(s, bmap_nr_new);
161 s->s_dirt = 1;
162
163 journal_mark_dirty(&th, s, SB_BUFFER_WITH_SB(s));
164
165 SB_JOURNAL(s)->j_must_wait = 1;
166 journal_end(&th, s, 10);
167
168 return 0;
169 }
170
171