Commit | Line | Data |
---|---|---|
24bbb1fa | 1 | /* |
f19bfb2c | 2 | * arch/s390/hypfs/inode.c |
24bbb1fa MH |
3 | * Hypervisor filesystem for Linux on s390. |
4 | * | |
5 | * Copyright (C) IBM Corp. 2006 | |
6 | * Author(s): Michael Holzheu <holzheu@de.ibm.com> | |
7 | */ | |
8 | ||
9 | #include <linux/types.h> | |
10 | #include <linux/errno.h> | |
11 | #include <linux/fs.h> | |
12 | #include <linux/namei.h> | |
13 | #include <linux/vfs.h> | |
14 | #include <linux/pagemap.h> | |
15 | #include <linux/gfp.h> | |
16 | #include <linux/time.h> | |
17 | #include <linux/parser.h> | |
18 | #include <linux/sysfs.h> | |
19 | #include <linux/module.h> | |
20 | #include <asm/ebcdic.h> | |
21 | #include "hypfs.h" | |
22 | #include "hypfs_diag.h" | |
23 | ||
24 | #define HYPFS_MAGIC 0x687970 /* ASCII 'hyp' */ | |
25 | #define TMP_SIZE 64 /* size of temporary buffers */ | |
26 | ||
27 | static struct dentry *hypfs_create_update_file(struct super_block *sb, | |
28 | struct dentry *dir); | |
29 | ||
30 | struct hypfs_sb_info { | |
31 | uid_t uid; /* uid used for files and dirs */ | |
32 | gid_t gid; /* gid used for files and dirs */ | |
33 | struct dentry *update_file; /* file to trigger update */ | |
34 | time_t last_update; /* last update time in secs since 1970 */ | |
35 | struct mutex lock; /* lock to protect update process */ | |
36 | }; | |
37 | ||
38 | static struct file_operations hypfs_file_ops; | |
39 | static struct file_system_type hypfs_type; | |
40 | static struct super_operations hypfs_s_ops; | |
41 | ||
42 | /* start of list of all dentries, which have to be deleted on update */ | |
43 | static struct dentry *hypfs_last_dentry; | |
44 | ||
45 | static void hypfs_update_update(struct super_block *sb) | |
46 | { | |
47 | struct hypfs_sb_info *sb_info = sb->s_fs_info; | |
48 | struct inode *inode = sb_info->update_file->d_inode; | |
49 | ||
50 | sb_info->last_update = get_seconds(); | |
51 | inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; | |
52 | } | |
53 | ||
54 | /* directory tree removal functions */ | |
55 | ||
56 | static void hypfs_add_dentry(struct dentry *dentry) | |
57 | { | |
58 | dentry->d_fsdata = hypfs_last_dentry; | |
59 | hypfs_last_dentry = dentry; | |
60 | } | |
61 | ||
62 | static void hypfs_remove(struct dentry *dentry) | |
63 | { | |
64 | struct dentry *parent; | |
65 | ||
66 | parent = dentry->d_parent; | |
67 | if (S_ISDIR(dentry->d_inode->i_mode)) | |
68 | simple_rmdir(parent->d_inode, dentry); | |
69 | else | |
70 | simple_unlink(parent->d_inode, dentry); | |
71 | d_delete(dentry); | |
72 | dput(dentry); | |
73 | } | |
74 | ||
75 | static void hypfs_delete_tree(struct dentry *root) | |
76 | { | |
77 | while (hypfs_last_dentry) { | |
78 | struct dentry *next_dentry; | |
79 | next_dentry = hypfs_last_dentry->d_fsdata; | |
80 | hypfs_remove(hypfs_last_dentry); | |
81 | hypfs_last_dentry = next_dentry; | |
82 | } | |
83 | } | |
84 | ||
85 | static struct inode *hypfs_make_inode(struct super_block *sb, int mode) | |
86 | { | |
87 | struct inode *ret = new_inode(sb); | |
88 | ||
89 | if (ret) { | |
90 | struct hypfs_sb_info *hypfs_info = sb->s_fs_info; | |
91 | ret->i_mode = mode; | |
92 | ret->i_uid = hypfs_info->uid; | |
93 | ret->i_gid = hypfs_info->gid; | |
24bbb1fa MH |
94 | ret->i_blocks = 0; |
95 | ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME; | |
96 | if (mode & S_IFDIR) | |
97 | ret->i_nlink = 2; | |
98 | else | |
99 | ret->i_nlink = 1; | |
100 | } | |
101 | return ret; | |
102 | } | |
103 | ||
104 | static void hypfs_drop_inode(struct inode *inode) | |
105 | { | |
8e18e294 | 106 | kfree(inode->i_private); |
24bbb1fa MH |
107 | generic_delete_inode(inode); |
108 | } | |
109 | ||
110 | static int hypfs_open(struct inode *inode, struct file *filp) | |
111 | { | |
8e18e294 | 112 | char *data = filp->f_dentry->d_inode->i_private; |
24bbb1fa MH |
113 | struct hypfs_sb_info *fs_info; |
114 | ||
115 | if (filp->f_mode & FMODE_WRITE) { | |
116 | if (!(inode->i_mode & S_IWUGO)) | |
117 | return -EACCES; | |
118 | } | |
119 | if (filp->f_mode & FMODE_READ) { | |
120 | if (!(inode->i_mode & S_IRUGO)) | |
121 | return -EACCES; | |
122 | } | |
123 | ||
124 | fs_info = inode->i_sb->s_fs_info; | |
125 | if(data) { | |
126 | mutex_lock(&fs_info->lock); | |
127 | filp->private_data = kstrdup(data, GFP_KERNEL); | |
128 | if (!filp->private_data) { | |
129 | mutex_unlock(&fs_info->lock); | |
130 | return -ENOMEM; | |
131 | } | |
132 | mutex_unlock(&fs_info->lock); | |
133 | } | |
134 | return 0; | |
135 | } | |
136 | ||
027445c3 BP |
137 | static ssize_t hypfs_aio_read(struct kiocb *iocb, const struct iovec *iov, |
138 | unsigned long nr_segs, loff_t offset) | |
24bbb1fa MH |
139 | { |
140 | char *data; | |
141 | size_t len; | |
142 | struct file *filp = iocb->ki_filp; | |
027445c3 BP |
143 | /* XXX: temporary */ |
144 | char __user *buf = iov[0].iov_base; | |
145 | size_t count = iov[0].iov_len; | |
146 | ||
147 | if (nr_segs != 1) { | |
148 | count = -EINVAL; | |
149 | goto out; | |
150 | } | |
24bbb1fa MH |
151 | |
152 | data = filp->private_data; | |
153 | len = strlen(data); | |
154 | if (offset > len) { | |
155 | count = 0; | |
156 | goto out; | |
157 | } | |
158 | if (count > len - offset) | |
159 | count = len - offset; | |
160 | if (copy_to_user(buf, data + offset, count)) { | |
161 | count = -EFAULT; | |
162 | goto out; | |
163 | } | |
164 | iocb->ki_pos += count; | |
165 | file_accessed(filp); | |
166 | out: | |
167 | return count; | |
168 | } | |
027445c3 BP |
169 | static ssize_t hypfs_aio_write(struct kiocb *iocb, const struct iovec *iov, |
170 | unsigned long nr_segs, loff_t offset) | |
24bbb1fa MH |
171 | { |
172 | int rc; | |
173 | struct super_block *sb; | |
174 | struct hypfs_sb_info *fs_info; | |
027445c3 | 175 | size_t count = iov_length(iov, nr_segs); |
24bbb1fa MH |
176 | |
177 | sb = iocb->ki_filp->f_dentry->d_inode->i_sb; | |
178 | fs_info = sb->s_fs_info; | |
179 | /* | |
180 | * Currently we only allow one update per second for two reasons: | |
181 | * 1. diag 204 is VERY expensive | |
182 | * 2. If several processes do updates in parallel and then read the | |
183 | * hypfs data, the likelihood of collisions is reduced, if we restrict | |
184 | * the minimum update interval. A collision occurs, if during the | |
185 | * data gathering of one process another process triggers an update | |
186 | * If the first process wants to ensure consistent data, it has | |
187 | * to restart data collection in this case. | |
188 | */ | |
189 | mutex_lock(&fs_info->lock); | |
190 | if (fs_info->last_update == get_seconds()) { | |
191 | rc = -EBUSY; | |
192 | goto out; | |
193 | } | |
194 | hypfs_delete_tree(sb->s_root); | |
195 | rc = hypfs_diag_create_files(sb, sb->s_root); | |
196 | if (rc) { | |
197 | printk(KERN_ERR "hypfs: Update failed\n"); | |
198 | hypfs_delete_tree(sb->s_root); | |
199 | goto out; | |
200 | } | |
201 | hypfs_update_update(sb); | |
202 | rc = count; | |
203 | out: | |
204 | mutex_unlock(&fs_info->lock); | |
205 | return rc; | |
206 | } | |
207 | ||
208 | static int hypfs_release(struct inode *inode, struct file *filp) | |
209 | { | |
210 | kfree(filp->private_data); | |
211 | return 0; | |
212 | } | |
213 | ||
214 | enum { opt_uid, opt_gid, opt_err }; | |
215 | ||
216 | static match_table_t hypfs_tokens = { | |
217 | {opt_uid, "uid=%u"}, | |
218 | {opt_gid, "gid=%u"}, | |
219 | {opt_err, NULL} | |
220 | }; | |
221 | ||
222 | static int hypfs_parse_options(char *options, struct super_block *sb) | |
223 | { | |
224 | char *str; | |
225 | substring_t args[MAX_OPT_ARGS]; | |
226 | ||
227 | if (!options) | |
228 | return 0; | |
229 | while ((str = strsep(&options, ",")) != NULL) { | |
230 | int token, option; | |
231 | struct hypfs_sb_info *hypfs_info = sb->s_fs_info; | |
232 | ||
233 | if (!*str) | |
234 | continue; | |
235 | token = match_token(str, hypfs_tokens, args); | |
236 | switch (token) { | |
237 | case opt_uid: | |
238 | if (match_int(&args[0], &option)) | |
239 | return -EINVAL; | |
240 | hypfs_info->uid = option; | |
241 | break; | |
242 | case opt_gid: | |
243 | if (match_int(&args[0], &option)) | |
244 | return -EINVAL; | |
245 | hypfs_info->gid = option; | |
246 | break; | |
247 | case opt_err: | |
248 | default: | |
249 | printk(KERN_ERR "hypfs: Unrecognized mount option " | |
250 | "\"%s\" or missing value\n", str); | |
251 | return -EINVAL; | |
252 | } | |
253 | } | |
254 | return 0; | |
255 | } | |
256 | ||
257 | static int hypfs_fill_super(struct super_block *sb, void *data, int silent) | |
258 | { | |
259 | struct inode *root_inode; | |
260 | struct dentry *root_dentry; | |
261 | int rc = 0; | |
262 | struct hypfs_sb_info *sbi; | |
263 | ||
264 | sbi = kzalloc(sizeof(struct hypfs_sb_info), GFP_KERNEL); | |
265 | if (!sbi) | |
266 | return -ENOMEM; | |
267 | mutex_init(&sbi->lock); | |
268 | sbi->uid = current->uid; | |
269 | sbi->gid = current->gid; | |
270 | sb->s_fs_info = sbi; | |
271 | sb->s_blocksize = PAGE_CACHE_SIZE; | |
272 | sb->s_blocksize_bits = PAGE_CACHE_SHIFT; | |
273 | sb->s_magic = HYPFS_MAGIC; | |
274 | sb->s_op = &hypfs_s_ops; | |
275 | if (hypfs_parse_options(data, sb)) { | |
276 | rc = -EINVAL; | |
277 | goto err_alloc; | |
278 | } | |
279 | root_inode = hypfs_make_inode(sb, S_IFDIR | 0755); | |
280 | if (!root_inode) { | |
281 | rc = -ENOMEM; | |
282 | goto err_alloc; | |
283 | } | |
284 | root_inode->i_op = &simple_dir_inode_operations; | |
285 | root_inode->i_fop = &simple_dir_operations; | |
286 | root_dentry = d_alloc_root(root_inode); | |
287 | if (!root_dentry) { | |
288 | iput(root_inode); | |
289 | rc = -ENOMEM; | |
290 | goto err_alloc; | |
291 | } | |
292 | rc = hypfs_diag_create_files(sb, root_dentry); | |
293 | if (rc) | |
294 | goto err_tree; | |
295 | sbi->update_file = hypfs_create_update_file(sb, root_dentry); | |
296 | if (IS_ERR(sbi->update_file)) { | |
297 | rc = PTR_ERR(sbi->update_file); | |
298 | goto err_tree; | |
299 | } | |
300 | hypfs_update_update(sb); | |
301 | sb->s_root = root_dentry; | |
302 | return 0; | |
303 | ||
304 | err_tree: | |
305 | hypfs_delete_tree(root_dentry); | |
306 | d_genocide(root_dentry); | |
307 | dput(root_dentry); | |
308 | err_alloc: | |
309 | kfree(sbi); | |
310 | return rc; | |
311 | } | |
312 | ||
a5cf4b9a AM |
313 | static int hypfs_get_super(struct file_system_type *fst, int flags, |
314 | const char *devname, void *data, struct vfsmount *mnt) | |
24bbb1fa | 315 | { |
a5cf4b9a | 316 | return get_sb_single(fst, flags, data, hypfs_fill_super, mnt); |
24bbb1fa MH |
317 | } |
318 | ||
319 | static void hypfs_kill_super(struct super_block *sb) | |
320 | { | |
321 | struct hypfs_sb_info *sb_info = sb->s_fs_info; | |
322 | ||
388c571c MH |
323 | if (sb->s_root) { |
324 | hypfs_delete_tree(sb->s_root); | |
325 | hypfs_remove(sb_info->update_file); | |
326 | kfree(sb->s_fs_info); | |
327 | sb->s_fs_info = NULL; | |
328 | } | |
24bbb1fa MH |
329 | kill_litter_super(sb); |
330 | } | |
331 | ||
332 | static struct dentry *hypfs_create_file(struct super_block *sb, | |
333 | struct dentry *parent, const char *name, | |
334 | char *data, mode_t mode) | |
335 | { | |
336 | struct dentry *dentry; | |
337 | struct inode *inode; | |
338 | struct qstr qname; | |
339 | ||
340 | qname.name = name; | |
341 | qname.len = strlen(name); | |
342 | qname.hash = full_name_hash(name, qname.len); | |
343 | dentry = lookup_one_len(name, parent, strlen(name)); | |
344 | if (IS_ERR(dentry)) | |
345 | return ERR_PTR(-ENOMEM); | |
346 | inode = hypfs_make_inode(sb, mode); | |
347 | if (!inode) { | |
348 | dput(dentry); | |
349 | return ERR_PTR(-ENOMEM); | |
350 | } | |
351 | if (mode & S_IFREG) { | |
352 | inode->i_fop = &hypfs_file_ops; | |
353 | if (data) | |
354 | inode->i_size = strlen(data); | |
355 | else | |
356 | inode->i_size = 0; | |
357 | } else if (mode & S_IFDIR) { | |
358 | inode->i_op = &simple_dir_inode_operations; | |
359 | inode->i_fop = &simple_dir_operations; | |
360 | parent->d_inode->i_nlink++; | |
361 | } else | |
362 | BUG(); | |
8e18e294 | 363 | inode->i_private = data; |
24bbb1fa MH |
364 | d_instantiate(dentry, inode); |
365 | dget(dentry); | |
366 | return dentry; | |
367 | } | |
368 | ||
369 | struct dentry *hypfs_mkdir(struct super_block *sb, struct dentry *parent, | |
370 | const char *name) | |
371 | { | |
372 | struct dentry *dentry; | |
373 | ||
374 | dentry = hypfs_create_file(sb, parent, name, NULL, S_IFDIR | DIR_MODE); | |
375 | if (IS_ERR(dentry)) | |
376 | return dentry; | |
377 | hypfs_add_dentry(dentry); | |
378 | parent->d_inode->i_nlink++; | |
379 | return dentry; | |
380 | } | |
381 | ||
382 | static struct dentry *hypfs_create_update_file(struct super_block *sb, | |
383 | struct dentry *dir) | |
384 | { | |
385 | struct dentry *dentry; | |
386 | ||
387 | dentry = hypfs_create_file(sb, dir, "update", NULL, | |
388 | S_IFREG | UPDATE_FILE_MODE); | |
389 | /* | |
390 | * We do not put the update file on the 'delete' list with | |
391 | * hypfs_add_dentry(), since it should not be removed when the tree | |
392 | * is updated. | |
393 | */ | |
394 | return dentry; | |
395 | } | |
396 | ||
397 | struct dentry *hypfs_create_u64(struct super_block *sb, struct dentry *dir, | |
398 | const char *name, __u64 value) | |
399 | { | |
400 | char *buffer; | |
401 | char tmp[TMP_SIZE]; | |
402 | struct dentry *dentry; | |
403 | ||
404 | snprintf(tmp, TMP_SIZE, "%lld\n", (unsigned long long int)value); | |
405 | buffer = kstrdup(tmp, GFP_KERNEL); | |
406 | if (!buffer) | |
407 | return ERR_PTR(-ENOMEM); | |
408 | dentry = | |
409 | hypfs_create_file(sb, dir, name, buffer, S_IFREG | REG_FILE_MODE); | |
410 | if (IS_ERR(dentry)) { | |
411 | kfree(buffer); | |
412 | return ERR_PTR(-ENOMEM); | |
413 | } | |
414 | hypfs_add_dentry(dentry); | |
415 | return dentry; | |
416 | } | |
417 | ||
418 | struct dentry *hypfs_create_str(struct super_block *sb, struct dentry *dir, | |
419 | const char *name, char *string) | |
420 | { | |
421 | char *buffer; | |
422 | struct dentry *dentry; | |
423 | ||
424 | buffer = kmalloc(strlen(string) + 2, GFP_KERNEL); | |
425 | if (!buffer) | |
426 | return ERR_PTR(-ENOMEM); | |
427 | sprintf(buffer, "%s\n", string); | |
428 | dentry = | |
429 | hypfs_create_file(sb, dir, name, buffer, S_IFREG | REG_FILE_MODE); | |
430 | if (IS_ERR(dentry)) { | |
431 | kfree(buffer); | |
432 | return ERR_PTR(-ENOMEM); | |
433 | } | |
434 | hypfs_add_dentry(dentry); | |
435 | return dentry; | |
436 | } | |
437 | ||
438 | static struct file_operations hypfs_file_ops = { | |
439 | .open = hypfs_open, | |
440 | .release = hypfs_release, | |
441 | .read = do_sync_read, | |
442 | .write = do_sync_write, | |
443 | .aio_read = hypfs_aio_read, | |
444 | .aio_write = hypfs_aio_write, | |
445 | }; | |
446 | ||
447 | static struct file_system_type hypfs_type = { | |
448 | .owner = THIS_MODULE, | |
449 | .name = "s390_hypfs", | |
450 | .get_sb = hypfs_get_super, | |
451 | .kill_sb = hypfs_kill_super | |
452 | }; | |
453 | ||
454 | static struct super_operations hypfs_s_ops = { | |
455 | .statfs = simple_statfs, | |
456 | .drop_inode = hypfs_drop_inode, | |
457 | }; | |
458 | ||
459 | static decl_subsys(s390, NULL, NULL); | |
460 | ||
461 | static int __init hypfs_init(void) | |
462 | { | |
463 | int rc; | |
464 | ||
465 | if (MACHINE_IS_VM) | |
466 | return -ENODATA; | |
467 | if (hypfs_diag_init()) { | |
468 | rc = -ENODATA; | |
469 | goto fail_diag; | |
470 | } | |
471 | kset_set_kset_s(&s390_subsys, hypervisor_subsys); | |
472 | rc = subsystem_register(&s390_subsys); | |
473 | if (rc) | |
474 | goto fail_sysfs; | |
475 | rc = register_filesystem(&hypfs_type); | |
476 | if (rc) | |
477 | goto fail_filesystem; | |
478 | return 0; | |
479 | ||
480 | fail_filesystem: | |
481 | subsystem_unregister(&s390_subsys); | |
482 | fail_sysfs: | |
483 | hypfs_diag_exit(); | |
484 | fail_diag: | |
485 | printk(KERN_ERR "hypfs: Initialization failed with rc = %i.\n", rc); | |
486 | return rc; | |
487 | } | |
488 | ||
489 | static void __exit hypfs_exit(void) | |
490 | { | |
491 | hypfs_diag_exit(); | |
492 | unregister_filesystem(&hypfs_type); | |
493 | subsystem_unregister(&s390_subsys); | |
494 | } | |
495 | ||
496 | module_init(hypfs_init) | |
497 | module_exit(hypfs_exit) | |
498 | ||
499 | MODULE_LICENSE("GPL"); | |
500 | MODULE_AUTHOR("Michael Holzheu <holzheu@de.ibm.com>"); | |
501 | MODULE_DESCRIPTION("s390 Hypervisor Filesystem"); |