macvlan: fix a possible use after free
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / reiserfs / resize.c
blob7483279b482d351f44073e86e9abf57f66e3731b
1 /*
2 * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
3 */
5 /*
6 * Written by Alexander Zarochentcev.
8 * The kernel part of the (on-line) reiserfs resizer.
9 */
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>
20 int reiserfs_resize(struct super_block *s, unsigned long block_count_new)
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;
32 struct reiserfs_list_bitmap *jb;
33 struct reiserfs_list_bitmap jbitmap[JOURNAL_NUM_BITMAPS];
35 unsigned long int block_count, free_blocks;
36 int i;
37 int copy_size;
39 sb = SB_DISK_SUPER_BLOCK(s);
41 if (SB_BLOCK_COUNT(s) >= block_count_new) {
42 printk("can\'t shrink filesystem on-line\n");
43 return -EINVAL;
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;
52 bforget(bh);
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;
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;
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;
75 /* save old values */
76 block_count = SB_BLOCK_COUNT(s);
77 bmap_nr = reiserfs_bmap_count(s);
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 return -ENOMEM;
87 /* the new journal bitmaps are zero filled, now we copy in the bitmap
88 ** node pointers from the old journal bitmap structs, and then
89 ** transfer the new data structures into the journal struct.
91 ** using the copy_size var below allows this code to work for
92 ** both shrinking and expanding the FS.
94 copy_size = bmap_nr_new < bmap_nr ? bmap_nr_new : bmap_nr;
95 copy_size =
96 copy_size * sizeof(struct reiserfs_list_bitmap_node *);
97 for (i = 0; i < JOURNAL_NUM_BITMAPS; i++) {
98 struct reiserfs_bitmap_node **node_tmp;
99 jb = SB_JOURNAL(s)->j_list_bitmap + i;
100 memcpy(jbitmap[i].bitmaps, jb->bitmaps, copy_size);
102 /* just in case vfree schedules on us, copy the new
103 ** pointer into the journal struct before freeing the
104 ** old one
106 node_tmp = jb->bitmaps;
107 jb->bitmaps = jbitmap[i].bitmaps;
108 vfree(node_tmp);
111 /* allocate additional bitmap blocks, reallocate array of bitmap
112 * block pointers */
113 bitmap =
114 vzalloc(sizeof(struct reiserfs_bitmap_info) * bmap_nr_new);
115 if (!bitmap) {
116 /* Journal bitmaps are still supersized, but the memory isn't
117 * leaked, so I guess it's ok */
118 printk("reiserfs_resize: unable to allocate memory.\n");
119 return -ENOMEM;
121 for (i = 0; i < bmap_nr; i++)
122 bitmap[i] = old_bitmap[i];
124 /* This doesn't go through the journal, but it doesn't have to.
125 * The changes are still atomic: We're synced up when the journal
126 * transaction begins, and the new bitmaps don't matter if the
127 * transaction fails. */
128 for (i = bmap_nr; i < bmap_nr_new; i++) {
129 /* don't use read_bitmap_block since it will cache
130 * the uninitialized bitmap */
131 bh = sb_bread(s, i * s->s_blocksize * 8);
132 if (!bh) {
133 vfree(bitmap);
134 return -EIO;
136 memset(bh->b_data, 0, sb_blocksize(sb));
137 reiserfs_set_le_bit(0, bh->b_data);
138 reiserfs_cache_bitmap_metadata(s, bh, bitmap + i);
140 set_buffer_uptodate(bh);
141 mark_buffer_dirty(bh);
142 reiserfs_write_unlock(s);
143 sync_dirty_buffer(bh);
144 reiserfs_write_lock(s);
145 // update bitmap_info stuff
146 bitmap[i].free_count = sb_blocksize(sb) * 8 - 1;
147 brelse(bh);
149 /* free old bitmap blocks array */
150 SB_AP_BITMAP(s) = bitmap;
151 vfree(old_bitmap);
154 /* begin transaction, if there was an error, it's fine. Yes, we have
155 * incorrect bitmaps now, but none of it is ever going to touch the
156 * disk anyway. */
157 err = journal_begin(&th, s, 10);
158 if (err)
159 return err;
161 /* Extend old last bitmap block - new blocks have been made available */
162 info = SB_AP_BITMAP(s) + bmap_nr - 1;
163 bh = reiserfs_read_bitmap_block(s, bmap_nr - 1);
164 if (!bh) {
165 int jerr = journal_end(&th, s, 10);
166 if (jerr)
167 return jerr;
168 return -EIO;
171 reiserfs_prepare_for_journal(s, bh, 1);
172 for (i = block_r; i < s->s_blocksize * 8; i++)
173 reiserfs_clear_le_bit(i, bh->b_data);
174 info->free_count += s->s_blocksize * 8 - block_r;
176 journal_mark_dirty(&th, s, bh);
177 brelse(bh);
179 /* Correct new last bitmap block - It may not be full */
180 info = SB_AP_BITMAP(s) + bmap_nr_new - 1;
181 bh = reiserfs_read_bitmap_block(s, bmap_nr_new - 1);
182 if (!bh) {
183 int jerr = journal_end(&th, s, 10);
184 if (jerr)
185 return jerr;
186 return -EIO;
189 reiserfs_prepare_for_journal(s, bh, 1);
190 for (i = block_r_new; i < s->s_blocksize * 8; i++)
191 reiserfs_set_le_bit(i, bh->b_data);
192 journal_mark_dirty(&th, s, bh);
193 brelse(bh);
195 info->free_count -= s->s_blocksize * 8 - block_r_new;
196 /* update super */
197 reiserfs_prepare_for_journal(s, SB_BUFFER_WITH_SB(s), 1);
198 free_blocks = SB_FREE_BLOCKS(s);
199 PUT_SB_FREE_BLOCKS(s,
200 free_blocks + (block_count_new - block_count -
201 (bmap_nr_new - bmap_nr)));
202 PUT_SB_BLOCK_COUNT(s, block_count_new);
203 PUT_SB_BMAP_NR(s, bmap_would_wrap(bmap_nr_new) ? : bmap_nr_new);
204 s->s_dirt = 1;
206 journal_mark_dirty(&th, s, SB_BUFFER_WITH_SB(s));
208 SB_JOURNAL(s)->j_must_wait = 1;
209 return journal_end(&th, s, 10);