1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * super.c |
4 | * |
5 | * Copyright (c) 1999 Al Smith |
6 | * |
7 | * Portions derived from work (c) 1995,1996 Christian Vogelgsang. |
8 | */ |
9 | |
10 | #include <linux/init.h> |
11 | #include <linux/module.h> |
12 | #include <linux/exportfs.h> |
13 | #include <linux/slab.h> |
14 | #include <linux/buffer_head.h> |
15 | #include <linux/vfs.h> |
16 | #include <linux/blkdev.h> |
17 | #include <linux/fs_context.h> |
18 | #include <linux/fs_parser.h> |
19 | #include "efs.h" |
20 | #include <linux/efs_vh.h> |
21 | #include <linux/efs_fs_sb.h> |
22 | |
23 | static int efs_statfs(struct dentry *dentry, struct kstatfs *buf); |
24 | static int efs_init_fs_context(struct fs_context *fc); |
25 | |
26 | static void efs_kill_sb(struct super_block *s) |
27 | { |
28 | struct efs_sb_info *sbi = SUPER_INFO(sb: s); |
29 | kill_block_super(sb: s); |
30 | kfree(objp: sbi); |
31 | } |
32 | |
33 | static struct pt_types sgi_pt_types[] = { |
34 | {0x00, "SGI vh" }, |
35 | {0x01, "SGI trkrepl" }, |
36 | {0x02, "SGI secrepl" }, |
37 | {0x03, "SGI raw" }, |
38 | {0x04, "SGI bsd" }, |
39 | {SGI_SYSV, "SGI sysv" }, |
40 | {0x06, "SGI vol" }, |
41 | {SGI_EFS, "SGI efs" }, |
42 | {0x08, "SGI lv" }, |
43 | {0x09, "SGI rlv" }, |
44 | {0x0A, "SGI xfs" }, |
45 | {0x0B, "SGI xfslog" }, |
46 | {0x0C, "SGI xlv" }, |
47 | {0x82, "Linux swap" }, |
48 | {0x83, "Linux native" }, |
49 | {0, NULL} |
50 | }; |
51 | |
52 | enum { |
53 | Opt_explicit_open, |
54 | }; |
55 | |
56 | static const struct fs_parameter_spec efs_param_spec[] = { |
57 | fsparam_flag ("explicit-open" , Opt_explicit_open), |
58 | {} |
59 | }; |
60 | |
61 | /* |
62 | * File system definition and registration. |
63 | */ |
64 | static struct file_system_type efs_fs_type = { |
65 | .owner = THIS_MODULE, |
66 | .name = "efs" , |
67 | .kill_sb = efs_kill_sb, |
68 | .fs_flags = FS_REQUIRES_DEV, |
69 | .init_fs_context = efs_init_fs_context, |
70 | .parameters = efs_param_spec, |
71 | }; |
72 | MODULE_ALIAS_FS("efs" ); |
73 | |
74 | static struct kmem_cache * efs_inode_cachep; |
75 | |
76 | static struct inode *efs_alloc_inode(struct super_block *sb) |
77 | { |
78 | struct efs_inode_info *ei; |
79 | ei = alloc_inode_sb(sb, cache: efs_inode_cachep, GFP_KERNEL); |
80 | if (!ei) |
81 | return NULL; |
82 | return &ei->vfs_inode; |
83 | } |
84 | |
85 | static void efs_free_inode(struct inode *inode) |
86 | { |
87 | kmem_cache_free(s: efs_inode_cachep, objp: INODE_INFO(inode)); |
88 | } |
89 | |
90 | static void init_once(void *foo) |
91 | { |
92 | struct efs_inode_info *ei = (struct efs_inode_info *) foo; |
93 | |
94 | inode_init_once(&ei->vfs_inode); |
95 | } |
96 | |
97 | static int __init init_inodecache(void) |
98 | { |
99 | efs_inode_cachep = kmem_cache_create(name: "efs_inode_cache" , |
100 | size: sizeof(struct efs_inode_info), align: 0, |
101 | SLAB_RECLAIM_ACCOUNT|SLAB_ACCOUNT, |
102 | ctor: init_once); |
103 | if (efs_inode_cachep == NULL) |
104 | return -ENOMEM; |
105 | return 0; |
106 | } |
107 | |
108 | static void destroy_inodecache(void) |
109 | { |
110 | /* |
111 | * Make sure all delayed rcu free inodes are flushed before we |
112 | * destroy cache. |
113 | */ |
114 | rcu_barrier(); |
115 | kmem_cache_destroy(s: efs_inode_cachep); |
116 | } |
117 | |
118 | static const struct super_operations efs_superblock_operations = { |
119 | .alloc_inode = efs_alloc_inode, |
120 | .free_inode = efs_free_inode, |
121 | .statfs = efs_statfs, |
122 | }; |
123 | |
124 | static const struct export_operations efs_export_ops = { |
125 | .encode_fh = generic_encode_ino32_fh, |
126 | .fh_to_dentry = efs_fh_to_dentry, |
127 | .fh_to_parent = efs_fh_to_parent, |
128 | .get_parent = efs_get_parent, |
129 | }; |
130 | |
131 | static int __init init_efs_fs(void) { |
132 | int err; |
133 | pr_info(EFS_VERSION" - http://aeschi.ch.eu.org/efs/\n" ); |
134 | err = init_inodecache(); |
135 | if (err) |
136 | goto out1; |
137 | err = register_filesystem(&efs_fs_type); |
138 | if (err) |
139 | goto out; |
140 | return 0; |
141 | out: |
142 | destroy_inodecache(); |
143 | out1: |
144 | return err; |
145 | } |
146 | |
147 | static void __exit exit_efs_fs(void) { |
148 | unregister_filesystem(&efs_fs_type); |
149 | destroy_inodecache(); |
150 | } |
151 | |
152 | module_init(init_efs_fs) |
153 | module_exit(exit_efs_fs) |
154 | |
155 | static efs_block_t efs_validate_vh(struct volume_header *vh) { |
156 | int i; |
157 | __be32 cs, *ui; |
158 | int csum; |
159 | efs_block_t sblock = 0; /* shuts up gcc */ |
160 | struct pt_types *pt_entry; |
161 | int pt_type, slice = -1; |
162 | |
163 | if (be32_to_cpu(vh->vh_magic) != VHMAGIC) { |
164 | /* |
165 | * assume that we're dealing with a partition and allow |
166 | * read_super() to try and detect a valid superblock |
167 | * on the next block. |
168 | */ |
169 | return 0; |
170 | } |
171 | |
172 | ui = ((__be32 *) (vh + 1)) - 1; |
173 | for(csum = 0; ui >= ((__be32 *) vh);) { |
174 | cs = *ui--; |
175 | csum += be32_to_cpu(cs); |
176 | } |
177 | if (csum) { |
178 | pr_warn("SGI disklabel: checksum bad, label corrupted\n" ); |
179 | return 0; |
180 | } |
181 | |
182 | #ifdef DEBUG |
183 | pr_debug("bf: \"%16s\"\n" , vh->vh_bootfile); |
184 | |
185 | for(i = 0; i < NVDIR; i++) { |
186 | int j; |
187 | char name[VDNAMESIZE+1]; |
188 | |
189 | for(j = 0; j < VDNAMESIZE; j++) { |
190 | name[j] = vh->vh_vd[i].vd_name[j]; |
191 | } |
192 | name[j] = (char) 0; |
193 | |
194 | if (name[0]) { |
195 | pr_debug("vh: %8s block: 0x%08x size: 0x%08x\n" , |
196 | name, (int) be32_to_cpu(vh->vh_vd[i].vd_lbn), |
197 | (int) be32_to_cpu(vh->vh_vd[i].vd_nbytes)); |
198 | } |
199 | } |
200 | #endif |
201 | |
202 | for(i = 0; i < NPARTAB; i++) { |
203 | pt_type = (int) be32_to_cpu(vh->vh_pt[i].pt_type); |
204 | for(pt_entry = sgi_pt_types; pt_entry->pt_name; pt_entry++) { |
205 | if (pt_type == pt_entry->pt_type) break; |
206 | } |
207 | #ifdef DEBUG |
208 | if (be32_to_cpu(vh->vh_pt[i].pt_nblks)) { |
209 | pr_debug("pt %2d: start: %08d size: %08d type: 0x%02x (%s)\n" , |
210 | i, (int)be32_to_cpu(vh->vh_pt[i].pt_firstlbn), |
211 | (int)be32_to_cpu(vh->vh_pt[i].pt_nblks), |
212 | pt_type, (pt_entry->pt_name) ? |
213 | pt_entry->pt_name : "unknown" ); |
214 | } |
215 | #endif |
216 | if (IS_EFS(pt_type)) { |
217 | sblock = be32_to_cpu(vh->vh_pt[i].pt_firstlbn); |
218 | slice = i; |
219 | } |
220 | } |
221 | |
222 | if (slice == -1) { |
223 | pr_notice("partition table contained no EFS partitions\n" ); |
224 | #ifdef DEBUG |
225 | } else { |
226 | pr_info("using slice %d (type %s, offset 0x%x)\n" , slice, |
227 | (pt_entry->pt_name) ? pt_entry->pt_name : "unknown" , |
228 | sblock); |
229 | #endif |
230 | } |
231 | return sblock; |
232 | } |
233 | |
234 | static 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 | |
251 | static int efs_fill_super(struct super_block *s, struct fs_context *fc) |
252 | { |
253 | struct efs_sb_info *sb; |
254 | struct buffer_head *bh; |
255 | struct inode *root; |
256 | |
257 | sb = kzalloc(size: sizeof(struct efs_sb_info), GFP_KERNEL); |
258 | if (!sb) |
259 | return -ENOMEM; |
260 | s->s_fs_info = sb; |
261 | s->s_time_min = 0; |
262 | s->s_time_max = U32_MAX; |
263 | |
264 | s->s_magic = EFS_SUPER_MAGIC; |
265 | if (!sb_set_blocksize(s, EFS_BLOCKSIZE)) { |
266 | pr_err("device does not support %d byte blocks\n" , |
267 | EFS_BLOCKSIZE); |
268 | return -EINVAL; |
269 | } |
270 | |
271 | /* read the vh (volume header) block */ |
272 | bh = sb_bread(sb: s, block: 0); |
273 | |
274 | if (!bh) { |
275 | pr_err("cannot read volume header\n" ); |
276 | return -EIO; |
277 | } |
278 | |
279 | /* |
280 | * if this returns zero then we didn't find any partition table. |
281 | * this isn't (yet) an error - just assume for the moment that |
282 | * the device is valid and go on to search for a superblock. |
283 | */ |
284 | sb->fs_start = efs_validate_vh(vh: (struct volume_header *) bh->b_data); |
285 | brelse(bh); |
286 | |
287 | if (sb->fs_start == -1) { |
288 | return -EINVAL; |
289 | } |
290 | |
291 | bh = sb_bread(sb: s, block: sb->fs_start + EFS_SUPER); |
292 | if (!bh) { |
293 | pr_err("cannot read superblock\n" ); |
294 | return -EIO; |
295 | } |
296 | |
297 | if (efs_validate_super(sb, super: (struct efs_super *) bh->b_data)) { |
298 | #ifdef DEBUG |
299 | pr_warn("invalid superblock at block %u\n" , |
300 | sb->fs_start + EFS_SUPER); |
301 | #endif |
302 | brelse(bh); |
303 | return -EINVAL; |
304 | } |
305 | brelse(bh); |
306 | |
307 | if (!sb_rdonly(sb: s)) { |
308 | #ifdef DEBUG |
309 | pr_info("forcing read-only mode\n" ); |
310 | #endif |
311 | s->s_flags |= SB_RDONLY; |
312 | } |
313 | s->s_op = &efs_superblock_operations; |
314 | s->s_export_op = &efs_export_ops; |
315 | root = efs_iget(s, EFS_ROOTINODE); |
316 | if (IS_ERR(ptr: root)) { |
317 | pr_err("get root inode failed\n" ); |
318 | return PTR_ERR(ptr: root); |
319 | } |
320 | |
321 | s->s_root = d_make_root(root); |
322 | if (!(s->s_root)) { |
323 | pr_err("get root dentry failed\n" ); |
324 | return -ENOMEM; |
325 | } |
326 | |
327 | return 0; |
328 | } |
329 | |
330 | static void efs_free_fc(struct fs_context *fc) |
331 | { |
332 | kfree(objp: fc->fs_private); |
333 | } |
334 | |
335 | static int efs_get_tree(struct fs_context *fc) |
336 | { |
337 | return get_tree_bdev(fc, fill_super: efs_fill_super); |
338 | } |
339 | |
340 | static int efs_parse_param(struct fs_context *fc, struct fs_parameter *param) |
341 | { |
342 | int token; |
343 | struct fs_parse_result result; |
344 | |
345 | token = fs_parse(fc, desc: efs_param_spec, param, result: &result); |
346 | if (token < 0) |
347 | return token; |
348 | return 0; |
349 | } |
350 | |
351 | static int efs_reconfigure(struct fs_context *fc) |
352 | { |
353 | sync_filesystem(fc->root->d_sb); |
354 | |
355 | return 0; |
356 | } |
357 | |
358 | struct efs_context { |
359 | unsigned long s_mount_opts; |
360 | }; |
361 | |
362 | static const struct fs_context_operations efs_context_opts = { |
363 | .parse_param = efs_parse_param, |
364 | .get_tree = efs_get_tree, |
365 | .reconfigure = efs_reconfigure, |
366 | .free = efs_free_fc, |
367 | }; |
368 | |
369 | /* |
370 | * Set up the filesystem mount context. |
371 | */ |
372 | static int efs_init_fs_context(struct fs_context *fc) |
373 | { |
374 | struct efs_context *ctx; |
375 | |
376 | ctx = kzalloc(size: sizeof(struct efs_context), GFP_KERNEL); |
377 | if (!ctx) |
378 | return -ENOMEM; |
379 | fc->fs_private = ctx; |
380 | fc->ops = &efs_context_opts; |
381 | |
382 | return 0; |
383 | } |
384 | |
385 | static int efs_statfs(struct dentry *dentry, struct kstatfs *buf) { |
386 | struct super_block *sb = dentry->d_sb; |
387 | struct efs_sb_info *sbi = SUPER_INFO(sb); |
388 | u64 id = huge_encode_dev(dev: sb->s_bdev->bd_dev); |
389 | |
390 | buf->f_type = EFS_SUPER_MAGIC; /* efs magic number */ |
391 | buf->f_bsize = EFS_BLOCKSIZE; /* blocksize */ |
392 | buf->f_blocks = sbi->total_groups * /* total data blocks */ |
393 | (sbi->group_size - sbi->inode_blocks); |
394 | buf->f_bfree = sbi->data_free; /* free data blocks */ |
395 | buf->f_bavail = sbi->data_free; /* free blocks for non-root */ |
396 | buf->f_files = sbi->total_groups * /* total inodes */ |
397 | sbi->inode_blocks * |
398 | (EFS_BLOCKSIZE / sizeof(struct efs_dinode)); |
399 | buf->f_ffree = sbi->inode_free; /* free inodes */ |
400 | buf->f_fsid = u64_to_fsid(v: id); |
401 | buf->f_namelen = EFS_MAXNAMELEN; /* max filename length */ |
402 | |
403 | return 0; |
404 | } |
405 | |
406 | |