Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1/*
2 * super.c
3 *
4 * Copyright (c) 1999 Al Smith
5 *
6 * Portions derived from work (c) 1995,1996 Christian Vogelgsang.
7 */
8
9#include <linux/init.h>
10#include <linux/module.h>
11#include <linux/exportfs.h>
12#include <linux/slab.h>
13#include <linux/buffer_head.h>
14#include <linux/vfs.h>
15
16#include "efs.h"
17#include <linux/efs_vh.h>
18#include <linux/efs_fs_sb.h>
19
20static int efs_statfs(struct dentry *dentry, struct kstatfs *buf);
21static int efs_fill_super(struct super_block *s, void *d, int silent);
22
23static struct dentry *efs_mount(struct file_system_type *fs_type,
24 int flags, const char *dev_name, void *data)
25{
26 return mount_bdev(fs_type, flags, dev_name, data, efs_fill_super);
27}
28
29static struct file_system_type efs_fs_type = {
30 .owner = THIS_MODULE,
31 .name = "efs",
32 .mount = efs_mount,
33 .kill_sb = kill_block_super,
34 .fs_flags = FS_REQUIRES_DEV,
35};
36
37static struct pt_types sgi_pt_types[] = {
38 {0x00, "SGI vh"},
39 {0x01, "SGI trkrepl"},
40 {0x02, "SGI secrepl"},
41 {0x03, "SGI raw"},
42 {0x04, "SGI bsd"},
43 {SGI_SYSV, "SGI sysv"},
44 {0x06, "SGI vol"},
45 {SGI_EFS, "SGI efs"},
46 {0x08, "SGI lv"},
47 {0x09, "SGI rlv"},
48 {0x0A, "SGI xfs"},
49 {0x0B, "SGI xfslog"},
50 {0x0C, "SGI xlv"},
51 {0x82, "Linux swap"},
52 {0x83, "Linux native"},
53 {0, NULL}
54};
55
56
57static struct kmem_cache * efs_inode_cachep;
58
59static struct inode *efs_alloc_inode(struct super_block *sb)
60{
61 struct efs_inode_info *ei;
62 ei = (struct efs_inode_info *)kmem_cache_alloc(efs_inode_cachep, GFP_KERNEL);
63 if (!ei)
64 return NULL;
65 return &ei->vfs_inode;
66}
67
68static void efs_i_callback(struct rcu_head *head)
69{
70 struct inode *inode = container_of(head, struct inode, i_rcu);
71 kmem_cache_free(efs_inode_cachep, INODE_INFO(inode));
72}
73
74static void efs_destroy_inode(struct inode *inode)
75{
76 call_rcu(&inode->i_rcu, efs_i_callback);
77}
78
79static void init_once(void *foo)
80{
81 struct efs_inode_info *ei = (struct efs_inode_info *) foo;
82
83 inode_init_once(&ei->vfs_inode);
84}
85
86static int init_inodecache(void)
87{
88 efs_inode_cachep = kmem_cache_create("efs_inode_cache",
89 sizeof(struct efs_inode_info),
90 0, SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
91 init_once);
92 if (efs_inode_cachep == NULL)
93 return -ENOMEM;
94 return 0;
95}
96
97static void destroy_inodecache(void)
98{
99 kmem_cache_destroy(efs_inode_cachep);
100}
101
102static void efs_put_super(struct super_block *s)
103{
104 kfree(s->s_fs_info);
105 s->s_fs_info = NULL;
106}
107
108static int efs_remount(struct super_block *sb, int *flags, char *data)
109{
110 *flags |= MS_RDONLY;
111 return 0;
112}
113
114static const struct super_operations efs_superblock_operations = {
115 .alloc_inode = efs_alloc_inode,
116 .destroy_inode = efs_destroy_inode,
117 .put_super = efs_put_super,
118 .statfs = efs_statfs,
119 .remount_fs = efs_remount,
120};
121
122static const struct export_operations efs_export_ops = {
123 .fh_to_dentry = efs_fh_to_dentry,
124 .fh_to_parent = efs_fh_to_parent,
125 .get_parent = efs_get_parent,
126};
127
128static int __init init_efs_fs(void) {
129 int err;
130 printk("EFS: "EFS_VERSION" - http://aeschi.ch.eu.org/efs/\n");
131 err = init_inodecache();
132 if (err)
133 goto out1;
134 err = register_filesystem(&efs_fs_type);
135 if (err)
136 goto out;
137 return 0;
138out:
139 destroy_inodecache();
140out1:
141 return err;
142}
143
144static void __exit exit_efs_fs(void) {
145 unregister_filesystem(&efs_fs_type);
146 destroy_inodecache();
147}
148
149module_init(init_efs_fs)
150module_exit(exit_efs_fs)
151
152static efs_block_t efs_validate_vh(struct volume_header *vh) {
153 int i;
154 __be32 cs, *ui;
155 int csum;
156 efs_block_t sblock = 0; /* shuts up gcc */
157 struct pt_types *pt_entry;
158 int pt_type, slice = -1;
159
160 if (be32_to_cpu(vh->vh_magic) != VHMAGIC) {
161 /*
162 * assume that we're dealing with a partition and allow
163 * read_super() to try and detect a valid superblock
164 * on the next block.
165 */
166 return 0;
167 }
168
169 ui = ((__be32 *) (vh + 1)) - 1;
170 for(csum = 0; ui >= ((__be32 *) vh);) {
171 cs = *ui--;
172 csum += be32_to_cpu(cs);
173 }
174 if (csum) {
175 printk(KERN_INFO "EFS: SGI disklabel: checksum bad, label corrupted\n");
176 return 0;
177 }
178
179#ifdef DEBUG
180 printk(KERN_DEBUG "EFS: bf: \"%16s\"\n", vh->vh_bootfile);
181
182 for(i = 0; i < NVDIR; i++) {
183 int j;
184 char name[VDNAMESIZE+1];
185
186 for(j = 0; j < VDNAMESIZE; j++) {
187 name[j] = vh->vh_vd[i].vd_name[j];
188 }
189 name[j] = (char) 0;
190
191 if (name[0]) {
192 printk(KERN_DEBUG "EFS: vh: %8s block: 0x%08x size: 0x%08x\n",
193 name,
194 (int) be32_to_cpu(vh->vh_vd[i].vd_lbn),
195 (int) be32_to_cpu(vh->vh_vd[i].vd_nbytes));
196 }
197 }
198#endif
199
200 for(i = 0; i < NPARTAB; i++) {
201 pt_type = (int) be32_to_cpu(vh->vh_pt[i].pt_type);
202 for(pt_entry = sgi_pt_types; pt_entry->pt_name; pt_entry++) {
203 if (pt_type == pt_entry->pt_type) break;
204 }
205#ifdef DEBUG
206 if (be32_to_cpu(vh->vh_pt[i].pt_nblks)) {
207 printk(KERN_DEBUG "EFS: pt %2d: start: %08d size: %08d type: 0x%02x (%s)\n",
208 i,
209 (int) be32_to_cpu(vh->vh_pt[i].pt_firstlbn),
210 (int) be32_to_cpu(vh->vh_pt[i].pt_nblks),
211 pt_type,
212 (pt_entry->pt_name) ? pt_entry->pt_name : "unknown");
213 }
214#endif
215 if (IS_EFS(pt_type)) {
216 sblock = be32_to_cpu(vh->vh_pt[i].pt_firstlbn);
217 slice = i;
218 }
219 }
220
221 if (slice == -1) {
222 printk(KERN_NOTICE "EFS: partition table contained no EFS partitions\n");
223#ifdef DEBUG
224 } else {
225 printk(KERN_INFO "EFS: using slice %d (type %s, offset 0x%x)\n",
226 slice,
227 (pt_entry->pt_name) ? pt_entry->pt_name : "unknown",
228 sblock);
229#endif
230 }
231 return sblock;
232}
233
234static int efs_validate_super(struct efs_sb_info *sb, struct efs_super *super) {
235
236 if (!IS_EFS_MAGIC(be32_to_cpu(super->fs_magic)))
237 return -1;
238
239 sb->fs_magic = be32_to_cpu(super->fs_magic);
240 sb->total_blocks = be32_to_cpu(super->fs_size);
241 sb->first_block = be32_to_cpu(super->fs_firstcg);
242 sb->group_size = be32_to_cpu(super->fs_cgfsize);
243 sb->data_free = be32_to_cpu(super->fs_tfree);
244 sb->inode_free = be32_to_cpu(super->fs_tinode);
245 sb->inode_blocks = be16_to_cpu(super->fs_cgisize);
246 sb->total_groups = be16_to_cpu(super->fs_ncg);
247
248 return 0;
249}
250
251static int efs_fill_super(struct super_block *s, void *d, int silent)
252{
253 struct efs_sb_info *sb;
254 struct buffer_head *bh;
255 struct inode *root;
256 int ret = -EINVAL;
257
258 sb = kzalloc(sizeof(struct efs_sb_info), GFP_KERNEL);
259 if (!sb)
260 return -ENOMEM;
261 s->s_fs_info = sb;
262
263 s->s_magic = EFS_SUPER_MAGIC;
264 if (!sb_set_blocksize(s, EFS_BLOCKSIZE)) {
265 printk(KERN_ERR "EFS: device does not support %d byte blocks\n",
266 EFS_BLOCKSIZE);
267 goto out_no_fs_ul;
268 }
269
270 /* read the vh (volume header) block */
271 bh = sb_bread(s, 0);
272
273 if (!bh) {
274 printk(KERN_ERR "EFS: cannot read volume header\n");
275 goto out_no_fs_ul;
276 }
277
278 /*
279 * if this returns zero then we didn't find any partition table.
280 * this isn't (yet) an error - just assume for the moment that
281 * the device is valid and go on to search for a superblock.
282 */
283 sb->fs_start = efs_validate_vh((struct volume_header *) bh->b_data);
284 brelse(bh);
285
286 if (sb->fs_start == -1) {
287 goto out_no_fs_ul;
288 }
289
290 bh = sb_bread(s, sb->fs_start + EFS_SUPER);
291 if (!bh) {
292 printk(KERN_ERR "EFS: cannot read superblock\n");
293 goto out_no_fs_ul;
294 }
295
296 if (efs_validate_super(sb, (struct efs_super *) bh->b_data)) {
297#ifdef DEBUG
298 printk(KERN_WARNING "EFS: invalid superblock at block %u\n", sb->fs_start + EFS_SUPER);
299#endif
300 brelse(bh);
301 goto out_no_fs_ul;
302 }
303 brelse(bh);
304
305 if (!(s->s_flags & MS_RDONLY)) {
306#ifdef DEBUG
307 printk(KERN_INFO "EFS: forcing read-only mode\n");
308#endif
309 s->s_flags |= MS_RDONLY;
310 }
311 s->s_op = &efs_superblock_operations;
312 s->s_export_op = &efs_export_ops;
313 root = efs_iget(s, EFS_ROOTINODE);
314 if (IS_ERR(root)) {
315 printk(KERN_ERR "EFS: get root inode failed\n");
316 ret = PTR_ERR(root);
317 goto out_no_fs;
318 }
319
320 s->s_root = d_alloc_root(root);
321 if (!(s->s_root)) {
322 printk(KERN_ERR "EFS: get root dentry failed\n");
323 iput(root);
324 ret = -ENOMEM;
325 goto out_no_fs;
326 }
327
328 return 0;
329
330out_no_fs_ul:
331out_no_fs:
332 s->s_fs_info = NULL;
333 kfree(sb);
334 return ret;
335}
336
337static int efs_statfs(struct dentry *dentry, struct kstatfs *buf) {
338 struct super_block *sb = dentry->d_sb;
339 struct efs_sb_info *sbi = SUPER_INFO(sb);
340 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
341
342 buf->f_type = EFS_SUPER_MAGIC; /* efs magic number */
343 buf->f_bsize = EFS_BLOCKSIZE; /* blocksize */
344 buf->f_blocks = sbi->total_groups * /* total data blocks */
345 (sbi->group_size - sbi->inode_blocks);
346 buf->f_bfree = sbi->data_free; /* free data blocks */
347 buf->f_bavail = sbi->data_free; /* free blocks for non-root */
348 buf->f_files = sbi->total_groups * /* total inodes */
349 sbi->inode_blocks *
350 (EFS_BLOCKSIZE / sizeof(struct efs_dinode));
351 buf->f_ffree = sbi->inode_free; /* free inodes */
352 buf->f_fsid.val[0] = (u32)id;
353 buf->f_fsid.val[1] = (u32)(id >> 32);
354 buf->f_namelen = EFS_MAXNAMELEN; /* max filename length */
355
356 return 0;
357}
358