Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
[linux-2.6] / fs / reiserfs / resize.c
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 }