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Annotation of /trunk/mkinitrd-magellan/busybox/e2fsprogs/old_e2fsprogs/ext2fs/res_gdt.c

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Revision 816 - (hide annotations) (download)
Fri Apr 24 18:33:46 2009 UTC (15 years, 1 month ago) by niro
File MIME type: text/plain
File size: 5896 byte(s)
-updated to busybox-1.13.4
1 niro 532 /* vi: set sw=4 ts=4: */
2     /*
3     * res_gdt.c --- reserve blocks for growing the group descriptor table
4     * during online resizing.
5     *
6     * Copyright (C) 2002 Andreas Dilger
7     *
8     * %Begin-Header%
9     * This file may be redistributed under the terms of the GNU Public
10     * License.
11     * %End-Header%
12     */
13    
14     #include <stdio.h>
15     #include <string.h>
16     #include <time.h>
17     #include "ext2_fs.h"
18     #include "ext2fs.h"
19    
20     /*
21     * Iterate through the groups which hold BACKUP superblock/GDT copies in an
22     * ext3 filesystem. The counters should be initialized to 1, 5, and 7 before
23     * calling this for the first time. In a sparse filesystem it will be the
24     * sequence of powers of 3, 5, and 7: 1, 3, 5, 7, 9, 25, 27, 49, 81, ...
25     * For a non-sparse filesystem it will be every group: 1, 2, 3, 4, ...
26     */
27     static unsigned int list_backups(ext2_filsys fs, unsigned int *three,
28     unsigned int *five, unsigned int *seven)
29     {
30     unsigned int *min = three;
31     int mult = 3;
32     unsigned int ret;
33    
34     if (!(fs->super->s_feature_ro_compat &
35     EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER)) {
36     ret = *min;
37     *min += 1;
38     return ret;
39     }
40    
41     if (*five < *min) {
42     min = five;
43     mult = 5;
44     }
45     if (*seven < *min) {
46     min = seven;
47     mult = 7;
48     }
49    
50     ret = *min;
51     *min *= mult;
52    
53     return ret;
54     }
55    
56     /*
57     * This code assumes that the reserved blocks have already been marked in-use
58     * during ext2fs_initialize(), so that they are not allocated for other
59     * uses before we can add them to the resize inode (which has to come
60     * after the creation of the inode table).
61     */
62     errcode_t ext2fs_create_resize_inode(ext2_filsys fs)
63     {
64     errcode_t retval, retval2;
65     struct ext2_super_block *sb;
66     struct ext2_inode inode;
67     __u32 *dindir_buf, *gdt_buf;
68     int rsv_add;
69     unsigned long long apb, inode_size;
70     blk_t dindir_blk, rsv_off, gdt_off, gdt_blk;
71     int dindir_dirty = 0, inode_dirty = 0;
72    
73     EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
74    
75     sb = fs->super;
76    
77     retval = ext2fs_get_mem(2 * fs->blocksize, (void *)&dindir_buf);
78     if (retval)
79     goto out_free;
80     gdt_buf = (__u32 *)((char *)dindir_buf + fs->blocksize);
81    
82     retval = ext2fs_read_inode(fs, EXT2_RESIZE_INO, &inode);
83     if (retval)
84     goto out_free;
85    
86     /* Maximum possible file size (we donly use the dindirect blocks) */
87     apb = EXT2_ADDR_PER_BLOCK(sb);
88     rsv_add = fs->blocksize / 512;
89     if ((dindir_blk = inode.i_block[EXT2_DIND_BLOCK])) {
90     #ifdef RES_GDT_DEBUG
91     printf("reading GDT dindir %u\n", dindir_blk);
92     #endif
93     retval = ext2fs_read_ind_block(fs, dindir_blk, dindir_buf);
94     if (retval)
95     goto out_inode;
96     } else {
97     blk_t goal = 3 + sb->s_reserved_gdt_blocks +
98     fs->desc_blocks + fs->inode_blocks_per_group;
99    
100     retval = ext2fs_alloc_block(fs, goal, 0, &dindir_blk);
101     if (retval)
102     goto out_free;
103     inode.i_mode = LINUX_S_IFREG | 0600;
104     inode.i_links_count = 1;
105     inode.i_block[EXT2_DIND_BLOCK] = dindir_blk;
106     inode.i_blocks = rsv_add;
107     memset(dindir_buf, 0, fs->blocksize);
108     #ifdef RES_GDT_DEBUG
109     printf("allocated GDT dindir %u\n", dindir_blk);
110     #endif
111     dindir_dirty = inode_dirty = 1;
112     inode_size = apb*apb + apb + EXT2_NDIR_BLOCKS;
113     inode_size *= fs->blocksize;
114     inode.i_size = inode_size & 0xFFFFFFFF;
115     inode.i_size_high = (inode_size >> 32) & 0xFFFFFFFF;
116 niro 816 if (inode.i_size_high) {
117 niro 532 sb->s_feature_ro_compat |=
118     EXT2_FEATURE_RO_COMPAT_LARGE_FILE;
119     }
120     inode.i_ctime = time(0);
121     }
122    
123     for (rsv_off = 0, gdt_off = fs->desc_blocks,
124     gdt_blk = sb->s_first_data_block + 1 + fs->desc_blocks;
125     rsv_off < sb->s_reserved_gdt_blocks;
126     rsv_off++, gdt_off++, gdt_blk++) {
127     unsigned int three = 1, five = 5, seven = 7;
128     unsigned int grp, last = 0;
129     int gdt_dirty = 0;
130    
131     gdt_off %= apb;
132     if (!dindir_buf[gdt_off]) {
133     /* FIXME XXX XXX
134     blk_t new_blk;
135    
136     retval = ext2fs_new_block(fs, gdt_blk, 0, &new_blk);
137     if (retval)
138     goto out_free;
139     if (new_blk != gdt_blk) {
140     // XXX free block
141     retval = -1; // XXX
142     }
143     */
144     gdt_dirty = dindir_dirty = inode_dirty = 1;
145     memset(gdt_buf, 0, fs->blocksize);
146     dindir_buf[gdt_off] = gdt_blk;
147     inode.i_blocks += rsv_add;
148     #ifdef RES_GDT_DEBUG
149     printf("added primary GDT block %u at %u[%u]\n",
150     gdt_blk, dindir_blk, gdt_off);
151     #endif
152     } else if (dindir_buf[gdt_off] == gdt_blk) {
153     #ifdef RES_GDT_DEBUG
154     printf("reading primary GDT block %u\n", gdt_blk);
155     #endif
156     retval = ext2fs_read_ind_block(fs, gdt_blk, gdt_buf);
157     if (retval)
158     goto out_dindir;
159     } else {
160     #ifdef RES_GDT_DEBUG
161     printf("bad primary GDT %u != %u at %u[%u]\n",
162     dindir_buf[gdt_off], gdt_blk,dindir_blk,gdt_off);
163     #endif
164     retval = EXT2_ET_RESIZE_INODE_CORRUPT;
165     goto out_dindir;
166     }
167    
168     while ((grp = list_backups(fs, &three, &five, &seven)) <
169     fs->group_desc_count) {
170     blk_t expect = gdt_blk + grp * sb->s_blocks_per_group;
171    
172     if (!gdt_buf[last]) {
173     #ifdef RES_GDT_DEBUG
174     printf("added backup GDT %u grp %u@%u[%u]\n",
175     expect, grp, gdt_blk, last);
176     #endif
177     gdt_buf[last] = expect;
178     inode.i_blocks += rsv_add;
179     gdt_dirty = inode_dirty = 1;
180     } else if (gdt_buf[last] != expect) {
181     #ifdef RES_GDT_DEBUG
182     printf("bad backup GDT %u != %u at %u[%u]\n",
183     gdt_buf[last], expect, gdt_blk, last);
184     #endif
185     retval = EXT2_ET_RESIZE_INODE_CORRUPT;
186     goto out_dindir;
187     }
188     last++;
189     }
190     if (gdt_dirty) {
191     #ifdef RES_GDT_DEBUG
192     printf("writing primary GDT block %u\n", gdt_blk);
193     #endif
194     retval = ext2fs_write_ind_block(fs, gdt_blk, gdt_buf);
195     if (retval)
196     goto out_dindir;
197     }
198     }
199    
200     out_dindir:
201     if (dindir_dirty) {
202     retval2 = ext2fs_write_ind_block(fs, dindir_blk, dindir_buf);
203     if (!retval)
204     retval = retval2;
205     }
206     out_inode:
207     #ifdef RES_GDT_DEBUG
208     printf("inode.i_blocks = %u, i_size = %u\n", inode.i_blocks,
209     inode.i_size);
210     #endif
211     if (inode_dirty) {
212     inode.i_atime = inode.i_mtime = time(0);
213     retval2 = ext2fs_write_inode(fs, EXT2_RESIZE_INO, &inode);
214     if (!retval)
215     retval = retval2;
216     }
217     out_free:
218     ext2fs_free_mem((void *)&dindir_buf);
219     return retval;
220     }
221