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