1 /*
2 * Copyright 2000 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/mm.h>
13 #include <linux/vmalloc.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 #include <linux/buffer_head.h>
19
20 int reiserfs_resize(struct super_block *s, unsigned long block_count_new)
21 {
22 int err = 0;
23 struct reiserfs_super_block *sb;
24 struct reiserfs_bitmap_info *bitmap;
25 struct reiserfs_bitmap_info *info;
26 struct reiserfs_bitmap_info *old_bitmap = SB_AP_BITMAP(s);
27 struct buffer_head *bh;
28 struct reiserfs_transaction_handle th;
29 unsigned int bmap_nr_new, bmap_nr;
30 unsigned int block_r_new, block_r;
31
32 struct reiserfs_list_bitmap *jb;
33 struct reiserfs_list_bitmap jbitmap[JOURNAL_NUM_BITMAPS];
34
35 unsigned long int block_count, free_blocks;
36 int i;
37 int copy_size;
38
39 sb = SB_DISK_SUPER_BLOCK(s);
40
41 if (SB_BLOCK_COUNT(s) >= block_count_new) {
42 printk("can\'t shrink filesystem on-line\n");
43 return -EINVAL;
44 }
45
46 /* check the device size */
47 bh = sb_bread(s, block_count_new - 1);
48 if (!bh) {
49 printk("reiserfs_resize: can\'t read last block\n");
50 return -EINVAL;
51 }
52 bforget(bh);
53
54 /* old disk layout detection; those partitions can be mounted, but
55 * cannot be resized */
56 if (SB_BUFFER_WITH_SB(s)->b_blocknr * SB_BUFFER_WITH_SB(s)->b_size
57 != REISERFS_DISK_OFFSET_IN_BYTES) {
58 printk
59 ("reiserfs_resize: unable to resize a reiserfs without distributed bitmap (fs version < 3.5.12)\n");
60 return -ENOTSUPP;
61 }
62
63 /* count used bits in last bitmap block */
64 block_r = SB_BLOCK_COUNT(s) -
65 (reiserfs_bmap_count(s) - 1) * s->s_blocksize * 8;
66
67 /* count bitmap blocks in new fs */
68 bmap_nr_new = block_count_new / (s->s_blocksize * 8);
69 block_r_new = block_count_new - bmap_nr_new * s->s_blocksize * 8;
70 if (block_r_new)
71 bmap_nr_new++;
72 else
73 block_r_new = s->s_blocksize * 8;
74
75 /* save old values */
76 block_count = SB_BLOCK_COUNT(s);
77 bmap_nr = reiserfs_bmap_count(s);
78
79 /* resizing of reiserfs bitmaps (journal and real), if needed */
80 if (bmap_nr_new > bmap_nr) {
81 /* reallocate journal bitmaps */
82 if (reiserfs_allocate_list_bitmaps(s, jbitmap, bmap_nr_new) < 0) {
83 printk
84 ("reiserfs_resize: unable to allocate memory for journal bitmaps\n");
85 unlock_super(s);
86 return -ENOMEM;
87 }
88 /* the new journal bitmaps are zero filled, now we copy in the bitmap
89 ** node pointers from the old journal bitmap structs, and then
90 ** transfer the new data structures into the journal struct.
91 **
92 ** using the copy_size var below allows this code to work for
93 ** both shrinking and expanding the FS.
94 */
95 copy_size = bmap_nr_new < bmap_nr ? bmap_nr_new : bmap_nr;
96 copy_size =
97 copy_size * sizeof(struct reiserfs_list_bitmap_node *);
98 for (i = 0; i < JOURNAL_NUM_BITMAPS; i++) {
99 struct reiserfs_bitmap_node **node_tmp;
100 jb = SB_JOURNAL(s)->j_list_bitmap + i;
101 memcpy(jbitmap[i].bitmaps, jb->bitmaps, copy_size);
102
103 /* just in case vfree schedules on us, copy the new
104 ** pointer into the journal struct before freeing the
105 ** old one
106 */
107 node_tmp = jb->bitmaps;
108 jb->bitmaps = jbitmap[i].bitmaps;
109 vfree(node_tmp);
110 }
111
112 /* allocate additional bitmap blocks, reallocate array of bitmap
113 * block pointers */
114 bitmap =
115 vmalloc(sizeof(struct reiserfs_bitmap_info) * bmap_nr_new);
116 if (!bitmap) {
117 /* Journal bitmaps are still supersized, but the memory isn't
118 * leaked, so I guess it's ok */
119 printk("reiserfs_resize: unable to allocate memory.\n");
120 return -ENOMEM;
121 }
122 memset(bitmap, 0,
123 sizeof(struct reiserfs_bitmap_info) * bmap_nr_new);
124 for (i = 0; i < bmap_nr; i++)
125 bitmap[i] = old_bitmap[i];
126
127 /* This doesn't go through the journal, but it doesn't have to.
128 * The changes are still atomic: We're synced up when the journal
129 * transaction begins, and the new bitmaps don't matter if the
130 * transaction fails. */
131 for (i = bmap_nr; i < bmap_nr_new; i++) {
132 /* don't use read_bitmap_block since it will cache
133 * the uninitialized bitmap */
134 bh = sb_bread(s, i * s->s_blocksize * 8);
135 if (!bh) {
136 vfree(bitmap);
137 return -EIO;
138 }
139 memset(bh->b_data, 0, sb_blocksize(sb));
140 reiserfs_test_and_set_le_bit(0, bh->b_data);
141 reiserfs_cache_bitmap_metadata(s, bh, bitmap + i);
142
143 set_buffer_uptodate(bh);
144 mark_buffer_dirty(bh);
145 sync_dirty_buffer(bh);
146 // update bitmap_info stuff
147 bitmap[i].free_count = sb_blocksize(sb) * 8 - 1;
148 brelse(bh);
149 }
150 /* free old bitmap blocks array */
151 SB_AP_BITMAP(s) = bitmap;
152 vfree(old_bitmap);
153 }
154
155 /* begin transaction, if there was an error, it's fine. Yes, we have
156 * incorrect bitmaps now, but none of it is ever going to touch the
157 * disk anyway. */
158 err = journal_begin(&th, s, 10);
159 if (err)
160 return err;
161
162 /* Extend old last bitmap block - new blocks have been made available */
163 info = SB_AP_BITMAP(s) + bmap_nr - 1;
164 bh = reiserfs_read_bitmap_block(s, bmap_nr - 1);
165 if (!bh) {
166 int jerr = journal_end(&th, s, 10);
167 if (jerr)
168 return jerr;
169 return -EIO;
170 }
171
172 reiserfs_prepare_for_journal(s, bh, 1);
173 for (i = block_r; i < s->s_blocksize * 8; i++)
174 reiserfs_test_and_clear_le_bit(i, bh->b_data);
175 info->free_count += s->s_blocksize * 8 - block_r;
176
177 journal_mark_dirty(&th, s, bh);
178 brelse(bh);
179
180 /* Correct new last bitmap block - It may not be full */
181 info = SB_AP_BITMAP(s) + bmap_nr_new - 1;
182 bh = reiserfs_read_bitmap_block(s, bmap_nr_new - 1);
183 if (!bh) {
184 int jerr = journal_end(&th, s, 10);
185 if (jerr)
186 return jerr;
187 return -EIO;
188 }
189
190 reiserfs_prepare_for_journal(s, bh, 1);
191 for (i = block_r_new; i < s->s_blocksize * 8; i++)
192 reiserfs_test_and_set_le_bit(i, bh->b_data);
193 journal_mark_dirty(&th, s, bh);
194 brelse(bh);
195
196 info->free_count -= s->s_blocksize * 8 - block_r_new;
197 /* update super */
198 reiserfs_prepare_for_journal(s, SB_BUFFER_WITH_SB(s), 1);
199 free_blocks = SB_FREE_BLOCKS(s);
200 PUT_SB_FREE_BLOCKS(s,
201 free_blocks + (block_count_new - block_count -
202 (bmap_nr_new - bmap_nr)));
203 PUT_SB_BLOCK_COUNT(s, block_count_new);
204 PUT_SB_BMAP_NR(s, bmap_would_wrap(bmap_nr_new) ? : bmap_nr_new);
205 s->s_dirt = 1;
206
207 journal_mark_dirty(&th, s, SB_BUFFER_WITH_SB(s));
208
209 SB_JOURNAL(s)->j_must_wait = 1;
210 return journal_end(&th, s, 10);
211 }
212
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