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-rw-r--r--fs/reiserfs/resize.c182
1 files changed, 182 insertions, 0 deletions
diff --git a/fs/reiserfs/resize.c b/fs/reiserfs/resize.c
new file mode 100644
index 000000000000..170012078b76
--- /dev/null
+++ b/fs/reiserfs/resize.c
@@ -0,0 +1,182 @@
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("reiserfs_resize: unable to resize a reiserfs without distributed bitmap (fs version < 3.5.12)\n");
58 return -ENOTSUPP;
59 }
60
61 /* count used bits in last bitmap block */
62 block_r = SB_BLOCK_COUNT(s) -
63 (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("reiserfs_resize: unable to allocate memory for journal bitmaps\n");
82 unlock_super(s) ;
83 return -ENOMEM ;
84 }
85 /* the new journal bitmaps are zero filled, now we copy in the bitmap
86 ** node pointers from the old journal bitmap structs, and then
87 ** transfer the new data structures into the journal struct.
88 **
89 ** using the copy_size var below allows this code to work for
90 ** both shrinking and expanding the FS.
91 */
92 copy_size = bmap_nr_new < bmap_nr ? bmap_nr_new : bmap_nr ;
93 copy_size = copy_size * sizeof(struct reiserfs_list_bitmap_node *) ;
94 for (i = 0 ; i < JOURNAL_NUM_BITMAPS ; i++) {
95 struct reiserfs_bitmap_node **node_tmp ;
96 jb = SB_JOURNAL(s)->j_list_bitmap + i ;
97 memcpy(jbitmap[i].bitmaps, jb->bitmaps, copy_size) ;
98
99 /* just in case vfree schedules on us, copy the new
100 ** pointer into the journal struct before freeing the
101 ** old one
102 */
103 node_tmp = jb->bitmaps ;
104 jb->bitmaps = jbitmap[i].bitmaps ;
105 vfree(node_tmp) ;
106 }
107
108 /* allocate additional bitmap blocks, reallocate array of bitmap
109 * block pointers */
110 bitmap = vmalloc(sizeof(struct reiserfs_bitmap_info) * bmap_nr_new);
111 if (!bitmap) {
112 /* Journal bitmaps are still supersized, but the memory isn't
113 * leaked, so I guess it's ok */
114 printk("reiserfs_resize: unable to allocate memory.\n");
115 return -ENOMEM;
116 }
117 memset (bitmap, 0, sizeof (struct reiserfs_bitmap_info) * SB_BMAP_NR(s));
118 for (i = 0; i < bmap_nr; i++)
119 bitmap[i] = old_bitmap[i];
120
121 /* This doesn't go through the journal, but it doesn't have to.
122 * The changes are still atomic: We're synced up when the journal
123 * transaction begins, and the new bitmaps don't matter if the
124 * transaction fails. */
125 for (i = bmap_nr; i < bmap_nr_new; i++) {
126 bitmap[i].bh = sb_getblk(s, i * s->s_blocksize * 8);
127 memset(bitmap[i].bh->b_data, 0, sb_blocksize(sb));
128 reiserfs_test_and_set_le_bit(0, bitmap[i].bh->b_data);
129
130 set_buffer_uptodate(bitmap[i].bh);
131 mark_buffer_dirty(bitmap[i].bh) ;
132 sync_dirty_buffer(bitmap[i].bh);
133 // update bitmap_info stuff
134 bitmap[i].first_zero_hint=1;
135 bitmap[i].free_count = sb_blocksize(sb) * 8 - 1;
136 }
137 /* free old bitmap blocks array */
138 SB_AP_BITMAP(s) = bitmap;
139 vfree (old_bitmap);
140 }
141
142 /* begin transaction, if there was an error, it's fine. Yes, we have
143 * incorrect bitmaps now, but none of it is ever going to touch the
144 * disk anyway. */
145 err = journal_begin(&th, s, 10);
146 if (err)
147 return err;
148
149 /* correct last bitmap blocks in old and new disk layout */
150 reiserfs_prepare_for_journal(s, SB_AP_BITMAP(s)[bmap_nr - 1].bh, 1);
151 for (i = block_r; i < s->s_blocksize * 8; i++)
152 reiserfs_test_and_clear_le_bit(i,
153 SB_AP_BITMAP(s)[bmap_nr - 1].bh->b_data);
154 SB_AP_BITMAP(s)[bmap_nr - 1].free_count += s->s_blocksize * 8 - block_r;
155 if ( !SB_AP_BITMAP(s)[bmap_nr - 1].first_zero_hint)
156 SB_AP_BITMAP(s)[bmap_nr - 1].first_zero_hint = block_r;
157
158 journal_mark_dirty(&th, s, SB_AP_BITMAP(s)[bmap_nr - 1].bh);
159
160 reiserfs_prepare_for_journal(s, SB_AP_BITMAP(s)[bmap_nr_new - 1].bh, 1);
161 for (i = block_r_new; i < s->s_blocksize * 8; i++)
162 reiserfs_test_and_set_le_bit(i,
163 SB_AP_BITMAP(s)[bmap_nr_new - 1].bh->b_data);
164 journal_mark_dirty(&th, s, SB_AP_BITMAP(s)[bmap_nr_new - 1].bh);
165
166 SB_AP_BITMAP(s)[bmap_nr_new - 1].free_count -= s->s_blocksize * 8 - block_r_new;
167 /* Extreme case where last bitmap is the only valid block in itself. */
168 if ( !SB_AP_BITMAP(s)[bmap_nr_new - 1].free_count )
169 SB_AP_BITMAP(s)[bmap_nr_new - 1].first_zero_hint = 0;
170 /* update super */
171 reiserfs_prepare_for_journal(s, SB_BUFFER_WITH_SB(s), 1) ;
172 free_blocks = SB_FREE_BLOCKS(s);
173 PUT_SB_FREE_BLOCKS(s, free_blocks + (block_count_new - block_count - (bmap_nr_new - bmap_nr)));
174 PUT_SB_BLOCK_COUNT(s, block_count_new);
175 PUT_SB_BMAP_NR(s, bmap_nr_new);
176 s->s_dirt = 1;
177
178 journal_mark_dirty(&th, s, SB_BUFFER_WITH_SB(s));
179
180 SB_JOURNAL(s)->j_must_wait = 1;
181 return journal_end(&th, s, 10);
182}
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