Commit | Line | Data |
---|---|---|
24bbb1fa | 1 | /* |
f19bfb2c | 2 | * arch/s390/hypfs/inode.c |
24bbb1fa MH |
3 | * Hypervisor filesystem for Linux on s390. |
4 | * | |
f55495ba | 5 | * Copyright IBM Corp. 2006, 2008 |
24bbb1fa MH |
6 | * Author(s): Michael Holzheu <holzheu@de.ibm.com> |
7 | */ | |
8 | ||
f55495ba MH |
9 | #define KMSG_COMPONENT "hypfs" |
10 | #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt | |
11 | ||
24bbb1fa MH |
12 | #include <linux/types.h> |
13 | #include <linux/errno.h> | |
14 | #include <linux/fs.h> | |
15 | #include <linux/namei.h> | |
16 | #include <linux/vfs.h> | |
17 | #include <linux/pagemap.h> | |
18 | #include <linux/gfp.h> | |
19 | #include <linux/time.h> | |
20 | #include <linux/parser.h> | |
21 | #include <linux/sysfs.h> | |
22 | #include <linux/module.h> | |
b01af5ba MH |
23 | #include <linux/seq_file.h> |
24 | #include <linux/mount.h> | |
24bbb1fa MH |
25 | #include <asm/ebcdic.h> |
26 | #include "hypfs.h" | |
24bbb1fa MH |
27 | |
28 | #define HYPFS_MAGIC 0x687970 /* ASCII 'hyp' */ | |
29 | #define TMP_SIZE 64 /* size of temporary buffers */ | |
30 | ||
31 | static struct dentry *hypfs_create_update_file(struct super_block *sb, | |
32 | struct dentry *dir); | |
33 | ||
34 | struct hypfs_sb_info { | |
35 | uid_t uid; /* uid used for files and dirs */ | |
36 | gid_t gid; /* gid used for files and dirs */ | |
37 | struct dentry *update_file; /* file to trigger update */ | |
38 | time_t last_update; /* last update time in secs since 1970 */ | |
39 | struct mutex lock; /* lock to protect update process */ | |
40 | }; | |
41 | ||
5dfe4c96 | 42 | static const struct file_operations hypfs_file_ops; |
24bbb1fa MH |
43 | static struct file_system_type hypfs_type; |
44 | static struct super_operations hypfs_s_ops; | |
45 | ||
46 | /* start of list of all dentries, which have to be deleted on update */ | |
47 | static struct dentry *hypfs_last_dentry; | |
48 | ||
49 | static void hypfs_update_update(struct super_block *sb) | |
50 | { | |
51 | struct hypfs_sb_info *sb_info = sb->s_fs_info; | |
52 | struct inode *inode = sb_info->update_file->d_inode; | |
53 | ||
54 | sb_info->last_update = get_seconds(); | |
55 | inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; | |
56 | } | |
57 | ||
58 | /* directory tree removal functions */ | |
59 | ||
60 | static void hypfs_add_dentry(struct dentry *dentry) | |
61 | { | |
62 | dentry->d_fsdata = hypfs_last_dentry; | |
63 | hypfs_last_dentry = dentry; | |
64 | } | |
65 | ||
9b5a03e1 MH |
66 | static inline int hypfs_positive(struct dentry *dentry) |
67 | { | |
68 | return dentry->d_inode && !d_unhashed(dentry); | |
69 | } | |
70 | ||
24bbb1fa MH |
71 | static void hypfs_remove(struct dentry *dentry) |
72 | { | |
73 | struct dentry *parent; | |
74 | ||
75 | parent = dentry->d_parent; | |
9b5a03e1 MH |
76 | if (!parent || !parent->d_inode) |
77 | return; | |
78 | mutex_lock(&parent->d_inode->i_mutex); | |
79 | if (hypfs_positive(dentry)) { | |
80 | if (S_ISDIR(dentry->d_inode->i_mode)) | |
81 | simple_rmdir(parent->d_inode, dentry); | |
82 | else | |
83 | simple_unlink(parent->d_inode, dentry); | |
84 | } | |
24bbb1fa MH |
85 | d_delete(dentry); |
86 | dput(dentry); | |
9b5a03e1 | 87 | mutex_unlock(&parent->d_inode->i_mutex); |
24bbb1fa MH |
88 | } |
89 | ||
90 | static void hypfs_delete_tree(struct dentry *root) | |
91 | { | |
92 | while (hypfs_last_dentry) { | |
93 | struct dentry *next_dentry; | |
94 | next_dentry = hypfs_last_dentry->d_fsdata; | |
95 | hypfs_remove(hypfs_last_dentry); | |
96 | hypfs_last_dentry = next_dentry; | |
97 | } | |
98 | } | |
99 | ||
100 | static struct inode *hypfs_make_inode(struct super_block *sb, int mode) | |
101 | { | |
102 | struct inode *ret = new_inode(sb); | |
103 | ||
104 | if (ret) { | |
105 | struct hypfs_sb_info *hypfs_info = sb->s_fs_info; | |
106 | ret->i_mode = mode; | |
107 | ret->i_uid = hypfs_info->uid; | |
108 | ret->i_gid = hypfs_info->gid; | |
24bbb1fa MH |
109 | ret->i_blocks = 0; |
110 | ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME; | |
111 | if (mode & S_IFDIR) | |
112 | ret->i_nlink = 2; | |
113 | else | |
114 | ret->i_nlink = 1; | |
115 | } | |
116 | return ret; | |
117 | } | |
118 | ||
119 | static void hypfs_drop_inode(struct inode *inode) | |
120 | { | |
8e18e294 | 121 | kfree(inode->i_private); |
24bbb1fa MH |
122 | generic_delete_inode(inode); |
123 | } | |
124 | ||
125 | static int hypfs_open(struct inode *inode, struct file *filp) | |
126 | { | |
d20343e7 | 127 | char *data = filp->f_path.dentry->d_inode->i_private; |
24bbb1fa MH |
128 | struct hypfs_sb_info *fs_info; |
129 | ||
130 | if (filp->f_mode & FMODE_WRITE) { | |
131 | if (!(inode->i_mode & S_IWUGO)) | |
132 | return -EACCES; | |
133 | } | |
134 | if (filp->f_mode & FMODE_READ) { | |
135 | if (!(inode->i_mode & S_IRUGO)) | |
136 | return -EACCES; | |
137 | } | |
138 | ||
139 | fs_info = inode->i_sb->s_fs_info; | |
140 | if(data) { | |
141 | mutex_lock(&fs_info->lock); | |
142 | filp->private_data = kstrdup(data, GFP_KERNEL); | |
143 | if (!filp->private_data) { | |
144 | mutex_unlock(&fs_info->lock); | |
145 | return -ENOMEM; | |
146 | } | |
147 | mutex_unlock(&fs_info->lock); | |
148 | } | |
149 | return 0; | |
150 | } | |
151 | ||
027445c3 BP |
152 | static ssize_t hypfs_aio_read(struct kiocb *iocb, const struct iovec *iov, |
153 | unsigned long nr_segs, loff_t offset) | |
24bbb1fa MH |
154 | { |
155 | char *data; | |
a29591c4 | 156 | ssize_t ret; |
24bbb1fa | 157 | struct file *filp = iocb->ki_filp; |
027445c3 BP |
158 | /* XXX: temporary */ |
159 | char __user *buf = iov[0].iov_base; | |
160 | size_t count = iov[0].iov_len; | |
161 | ||
a29591c4 AM |
162 | if (nr_segs != 1) |
163 | return -EINVAL; | |
24bbb1fa MH |
164 | |
165 | data = filp->private_data; | |
a29591c4 AM |
166 | ret = simple_read_from_buffer(buf, count, &offset, data, strlen(data)); |
167 | if (ret <= 0) | |
168 | return ret; | |
169 | ||
170 | iocb->ki_pos += ret; | |
24bbb1fa | 171 | file_accessed(filp); |
a29591c4 AM |
172 | |
173 | return ret; | |
24bbb1fa | 174 | } |
027445c3 BP |
175 | static ssize_t hypfs_aio_write(struct kiocb *iocb, const struct iovec *iov, |
176 | unsigned long nr_segs, loff_t offset) | |
24bbb1fa MH |
177 | { |
178 | int rc; | |
179 | struct super_block *sb; | |
180 | struct hypfs_sb_info *fs_info; | |
027445c3 | 181 | size_t count = iov_length(iov, nr_segs); |
24bbb1fa | 182 | |
d20343e7 | 183 | sb = iocb->ki_filp->f_path.dentry->d_inode->i_sb; |
24bbb1fa MH |
184 | fs_info = sb->s_fs_info; |
185 | /* | |
186 | * Currently we only allow one update per second for two reasons: | |
187 | * 1. diag 204 is VERY expensive | |
188 | * 2. If several processes do updates in parallel and then read the | |
189 | * hypfs data, the likelihood of collisions is reduced, if we restrict | |
190 | * the minimum update interval. A collision occurs, if during the | |
191 | * data gathering of one process another process triggers an update | |
192 | * If the first process wants to ensure consistent data, it has | |
193 | * to restart data collection in this case. | |
194 | */ | |
195 | mutex_lock(&fs_info->lock); | |
196 | if (fs_info->last_update == get_seconds()) { | |
197 | rc = -EBUSY; | |
198 | goto out; | |
199 | } | |
200 | hypfs_delete_tree(sb->s_root); | |
31cb4bd3 MH |
201 | if (MACHINE_IS_VM) |
202 | rc = hypfs_vm_create_files(sb, sb->s_root); | |
203 | else | |
204 | rc = hypfs_diag_create_files(sb, sb->s_root); | |
24bbb1fa | 205 | if (rc) { |
f55495ba | 206 | pr_err("Updating the hypfs tree failed\n"); |
24bbb1fa MH |
207 | hypfs_delete_tree(sb->s_root); |
208 | goto out; | |
209 | } | |
210 | hypfs_update_update(sb); | |
211 | rc = count; | |
212 | out: | |
213 | mutex_unlock(&fs_info->lock); | |
214 | return rc; | |
215 | } | |
216 | ||
217 | static int hypfs_release(struct inode *inode, struct file *filp) | |
218 | { | |
219 | kfree(filp->private_data); | |
220 | return 0; | |
221 | } | |
222 | ||
223 | enum { opt_uid, opt_gid, opt_err }; | |
224 | ||
a447c093 | 225 | static const match_table_t hypfs_tokens = { |
24bbb1fa MH |
226 | {opt_uid, "uid=%u"}, |
227 | {opt_gid, "gid=%u"}, | |
228 | {opt_err, NULL} | |
229 | }; | |
230 | ||
231 | static int hypfs_parse_options(char *options, struct super_block *sb) | |
232 | { | |
233 | char *str; | |
234 | substring_t args[MAX_OPT_ARGS]; | |
235 | ||
236 | if (!options) | |
237 | return 0; | |
238 | while ((str = strsep(&options, ",")) != NULL) { | |
239 | int token, option; | |
240 | struct hypfs_sb_info *hypfs_info = sb->s_fs_info; | |
241 | ||
242 | if (!*str) | |
243 | continue; | |
244 | token = match_token(str, hypfs_tokens, args); | |
245 | switch (token) { | |
246 | case opt_uid: | |
247 | if (match_int(&args[0], &option)) | |
248 | return -EINVAL; | |
249 | hypfs_info->uid = option; | |
250 | break; | |
251 | case opt_gid: | |
252 | if (match_int(&args[0], &option)) | |
253 | return -EINVAL; | |
254 | hypfs_info->gid = option; | |
255 | break; | |
256 | case opt_err: | |
257 | default: | |
f55495ba | 258 | pr_err("%s is not a valid mount option\n", str); |
24bbb1fa MH |
259 | return -EINVAL; |
260 | } | |
261 | } | |
262 | return 0; | |
263 | } | |
264 | ||
b01af5ba MH |
265 | static int hypfs_show_options(struct seq_file *s, struct vfsmount *mnt) |
266 | { | |
267 | struct hypfs_sb_info *hypfs_info = mnt->mnt_sb->s_fs_info; | |
268 | ||
269 | seq_printf(s, ",uid=%u", hypfs_info->uid); | |
270 | seq_printf(s, ",gid=%u", hypfs_info->gid); | |
271 | return 0; | |
272 | } | |
273 | ||
24bbb1fa MH |
274 | static int hypfs_fill_super(struct super_block *sb, void *data, int silent) |
275 | { | |
276 | struct inode *root_inode; | |
277 | struct dentry *root_dentry; | |
278 | int rc = 0; | |
279 | struct hypfs_sb_info *sbi; | |
280 | ||
281 | sbi = kzalloc(sizeof(struct hypfs_sb_info), GFP_KERNEL); | |
282 | if (!sbi) | |
283 | return -ENOMEM; | |
284 | mutex_init(&sbi->lock); | |
e5423705 DH |
285 | sbi->uid = current_uid(); |
286 | sbi->gid = current_gid(); | |
24bbb1fa MH |
287 | sb->s_fs_info = sbi; |
288 | sb->s_blocksize = PAGE_CACHE_SIZE; | |
289 | sb->s_blocksize_bits = PAGE_CACHE_SHIFT; | |
290 | sb->s_magic = HYPFS_MAGIC; | |
291 | sb->s_op = &hypfs_s_ops; | |
292 | if (hypfs_parse_options(data, sb)) { | |
293 | rc = -EINVAL; | |
294 | goto err_alloc; | |
295 | } | |
296 | root_inode = hypfs_make_inode(sb, S_IFDIR | 0755); | |
297 | if (!root_inode) { | |
298 | rc = -ENOMEM; | |
299 | goto err_alloc; | |
300 | } | |
301 | root_inode->i_op = &simple_dir_inode_operations; | |
302 | root_inode->i_fop = &simple_dir_operations; | |
303 | root_dentry = d_alloc_root(root_inode); | |
304 | if (!root_dentry) { | |
305 | iput(root_inode); | |
306 | rc = -ENOMEM; | |
307 | goto err_alloc; | |
308 | } | |
31cb4bd3 MH |
309 | if (MACHINE_IS_VM) |
310 | rc = hypfs_vm_create_files(sb, root_dentry); | |
311 | else | |
312 | rc = hypfs_diag_create_files(sb, root_dentry); | |
24bbb1fa MH |
313 | if (rc) |
314 | goto err_tree; | |
315 | sbi->update_file = hypfs_create_update_file(sb, root_dentry); | |
316 | if (IS_ERR(sbi->update_file)) { | |
317 | rc = PTR_ERR(sbi->update_file); | |
318 | goto err_tree; | |
319 | } | |
320 | hypfs_update_update(sb); | |
321 | sb->s_root = root_dentry; | |
f55495ba | 322 | pr_info("Hypervisor filesystem mounted\n"); |
24bbb1fa MH |
323 | return 0; |
324 | ||
325 | err_tree: | |
326 | hypfs_delete_tree(root_dentry); | |
327 | d_genocide(root_dentry); | |
328 | dput(root_dentry); | |
329 | err_alloc: | |
330 | kfree(sbi); | |
331 | return rc; | |
332 | } | |
333 | ||
a5cf4b9a AM |
334 | static int hypfs_get_super(struct file_system_type *fst, int flags, |
335 | const char *devname, void *data, struct vfsmount *mnt) | |
24bbb1fa | 336 | { |
a5cf4b9a | 337 | return get_sb_single(fst, flags, data, hypfs_fill_super, mnt); |
24bbb1fa MH |
338 | } |
339 | ||
340 | static void hypfs_kill_super(struct super_block *sb) | |
341 | { | |
342 | struct hypfs_sb_info *sb_info = sb->s_fs_info; | |
343 | ||
388c571c MH |
344 | if (sb->s_root) { |
345 | hypfs_delete_tree(sb->s_root); | |
346 | hypfs_remove(sb_info->update_file); | |
347 | kfree(sb->s_fs_info); | |
348 | sb->s_fs_info = NULL; | |
349 | } | |
24bbb1fa MH |
350 | kill_litter_super(sb); |
351 | } | |
352 | ||
353 | static struct dentry *hypfs_create_file(struct super_block *sb, | |
354 | struct dentry *parent, const char *name, | |
355 | char *data, mode_t mode) | |
356 | { | |
357 | struct dentry *dentry; | |
358 | struct inode *inode; | |
359 | struct qstr qname; | |
360 | ||
361 | qname.name = name; | |
362 | qname.len = strlen(name); | |
363 | qname.hash = full_name_hash(name, qname.len); | |
9b5a03e1 | 364 | mutex_lock(&parent->d_inode->i_mutex); |
24bbb1fa | 365 | dentry = lookup_one_len(name, parent, strlen(name)); |
9b5a03e1 MH |
366 | if (IS_ERR(dentry)) { |
367 | dentry = ERR_PTR(-ENOMEM); | |
368 | goto fail; | |
369 | } | |
24bbb1fa MH |
370 | inode = hypfs_make_inode(sb, mode); |
371 | if (!inode) { | |
372 | dput(dentry); | |
9b5a03e1 MH |
373 | dentry = ERR_PTR(-ENOMEM); |
374 | goto fail; | |
24bbb1fa MH |
375 | } |
376 | if (mode & S_IFREG) { | |
377 | inode->i_fop = &hypfs_file_ops; | |
378 | if (data) | |
379 | inode->i_size = strlen(data); | |
380 | else | |
381 | inode->i_size = 0; | |
382 | } else if (mode & S_IFDIR) { | |
383 | inode->i_op = &simple_dir_inode_operations; | |
384 | inode->i_fop = &simple_dir_operations; | |
385 | parent->d_inode->i_nlink++; | |
386 | } else | |
387 | BUG(); | |
8e18e294 | 388 | inode->i_private = data; |
24bbb1fa MH |
389 | d_instantiate(dentry, inode); |
390 | dget(dentry); | |
9b5a03e1 MH |
391 | fail: |
392 | mutex_unlock(&parent->d_inode->i_mutex); | |
24bbb1fa MH |
393 | return dentry; |
394 | } | |
395 | ||
396 | struct dentry *hypfs_mkdir(struct super_block *sb, struct dentry *parent, | |
397 | const char *name) | |
398 | { | |
399 | struct dentry *dentry; | |
400 | ||
401 | dentry = hypfs_create_file(sb, parent, name, NULL, S_IFDIR | DIR_MODE); | |
402 | if (IS_ERR(dentry)) | |
403 | return dentry; | |
404 | hypfs_add_dentry(dentry); | |
24bbb1fa MH |
405 | return dentry; |
406 | } | |
407 | ||
408 | static struct dentry *hypfs_create_update_file(struct super_block *sb, | |
409 | struct dentry *dir) | |
410 | { | |
411 | struct dentry *dentry; | |
412 | ||
413 | dentry = hypfs_create_file(sb, dir, "update", NULL, | |
414 | S_IFREG | UPDATE_FILE_MODE); | |
415 | /* | |
416 | * We do not put the update file on the 'delete' list with | |
417 | * hypfs_add_dentry(), since it should not be removed when the tree | |
418 | * is updated. | |
419 | */ | |
420 | return dentry; | |
421 | } | |
422 | ||
423 | struct dentry *hypfs_create_u64(struct super_block *sb, struct dentry *dir, | |
424 | const char *name, __u64 value) | |
425 | { | |
426 | char *buffer; | |
427 | char tmp[TMP_SIZE]; | |
428 | struct dentry *dentry; | |
429 | ||
430 | snprintf(tmp, TMP_SIZE, "%lld\n", (unsigned long long int)value); | |
431 | buffer = kstrdup(tmp, GFP_KERNEL); | |
432 | if (!buffer) | |
433 | return ERR_PTR(-ENOMEM); | |
434 | dentry = | |
435 | hypfs_create_file(sb, dir, name, buffer, S_IFREG | REG_FILE_MODE); | |
436 | if (IS_ERR(dentry)) { | |
437 | kfree(buffer); | |
438 | return ERR_PTR(-ENOMEM); | |
439 | } | |
440 | hypfs_add_dentry(dentry); | |
441 | return dentry; | |
442 | } | |
443 | ||
444 | struct dentry *hypfs_create_str(struct super_block *sb, struct dentry *dir, | |
445 | const char *name, char *string) | |
446 | { | |
447 | char *buffer; | |
448 | struct dentry *dentry; | |
449 | ||
450 | buffer = kmalloc(strlen(string) + 2, GFP_KERNEL); | |
451 | if (!buffer) | |
452 | return ERR_PTR(-ENOMEM); | |
453 | sprintf(buffer, "%s\n", string); | |
454 | dentry = | |
455 | hypfs_create_file(sb, dir, name, buffer, S_IFREG | REG_FILE_MODE); | |
456 | if (IS_ERR(dentry)) { | |
457 | kfree(buffer); | |
458 | return ERR_PTR(-ENOMEM); | |
459 | } | |
460 | hypfs_add_dentry(dentry); | |
461 | return dentry; | |
462 | } | |
463 | ||
5dfe4c96 | 464 | static const struct file_operations hypfs_file_ops = { |
24bbb1fa MH |
465 | .open = hypfs_open, |
466 | .release = hypfs_release, | |
467 | .read = do_sync_read, | |
468 | .write = do_sync_write, | |
469 | .aio_read = hypfs_aio_read, | |
470 | .aio_write = hypfs_aio_write, | |
471 | }; | |
472 | ||
473 | static struct file_system_type hypfs_type = { | |
474 | .owner = THIS_MODULE, | |
475 | .name = "s390_hypfs", | |
476 | .get_sb = hypfs_get_super, | |
477 | .kill_sb = hypfs_kill_super | |
478 | }; | |
479 | ||
480 | static struct super_operations hypfs_s_ops = { | |
481 | .statfs = simple_statfs, | |
482 | .drop_inode = hypfs_drop_inode, | |
b01af5ba | 483 | .show_options = hypfs_show_options, |
24bbb1fa MH |
484 | }; |
485 | ||
9b477705 | 486 | static struct kobject *s390_kobj; |
24bbb1fa MH |
487 | |
488 | static int __init hypfs_init(void) | |
489 | { | |
490 | int rc; | |
491 | ||
31cb4bd3 MH |
492 | if (MACHINE_IS_VM) { |
493 | if (hypfs_vm_init()) | |
494 | /* no diag 2fc, just exit */ | |
495 | return -ENODATA; | |
496 | } else { | |
497 | if (hypfs_diag_init()) { | |
498 | rc = -ENODATA; | |
499 | goto fail_diag; | |
500 | } | |
24bbb1fa | 501 | } |
9b477705 GKH |
502 | s390_kobj = kobject_create_and_add("s390", hypervisor_kobj); |
503 | if (!s390_kobj) { | |
504 | rc = -ENOMEM;; | |
24bbb1fa | 505 | goto fail_sysfs; |
9b477705 | 506 | } |
24bbb1fa MH |
507 | rc = register_filesystem(&hypfs_type); |
508 | if (rc) | |
509 | goto fail_filesystem; | |
510 | return 0; | |
511 | ||
512 | fail_filesystem: | |
38a382ae | 513 | kobject_put(s390_kobj); |
24bbb1fa | 514 | fail_sysfs: |
31cb4bd3 MH |
515 | if (!MACHINE_IS_VM) |
516 | hypfs_diag_exit(); | |
24bbb1fa | 517 | fail_diag: |
f55495ba | 518 | pr_err("Initialization of hypfs failed with rc=%i\n", rc); |
24bbb1fa MH |
519 | return rc; |
520 | } | |
521 | ||
522 | static void __exit hypfs_exit(void) | |
523 | { | |
31cb4bd3 MH |
524 | if (!MACHINE_IS_VM) |
525 | hypfs_diag_exit(); | |
24bbb1fa | 526 | unregister_filesystem(&hypfs_type); |
38a382ae | 527 | kobject_put(s390_kobj); |
24bbb1fa MH |
528 | } |
529 | ||
530 | module_init(hypfs_init) | |
531 | module_exit(hypfs_exit) | |
532 | ||
533 | MODULE_LICENSE("GPL"); | |
534 | MODULE_AUTHOR("Michael Holzheu <holzheu@de.ibm.com>"); | |
535 | MODULE_DESCRIPTION("s390 Hypervisor Filesystem"); |