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