Commit | Line | Data |
---|---|---|
24bbb1fa | 1 | /* |
24bbb1fa MH |
2 | * Hypervisor filesystem for Linux on s390. |
3 | * | |
f55495ba | 4 | * Copyright IBM Corp. 2006, 2008 |
24bbb1fa MH |
5 | * Author(s): Michael Holzheu <holzheu@de.ibm.com> |
6 | */ | |
7 | ||
f55495ba MH |
8 | #define KMSG_COMPONENT "hypfs" |
9 | #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt | |
10 | ||
24bbb1fa MH |
11 | #include <linux/types.h> |
12 | #include <linux/errno.h> | |
13 | #include <linux/fs.h> | |
14 | #include <linux/namei.h> | |
15 | #include <linux/vfs.h> | |
5a0e3ad6 | 16 | #include <linux/slab.h> |
24bbb1fa | 17 | #include <linux/pagemap.h> |
24bbb1fa MH |
18 | #include <linux/time.h> |
19 | #include <linux/parser.h> | |
20 | #include <linux/sysfs.h> | |
21 | #include <linux/module.h> | |
b01af5ba MH |
22 | #include <linux/seq_file.h> |
23 | #include <linux/mount.h> | |
24bbb1fa MH |
24 | #include <asm/ebcdic.h> |
25 | #include "hypfs.h" | |
24bbb1fa MH |
26 | |
27 | #define HYPFS_MAGIC 0x687970 /* ASCII 'hyp' */ | |
28 | #define TMP_SIZE 64 /* size of temporary buffers */ | |
29 | ||
30 | static struct dentry *hypfs_create_update_file(struct super_block *sb, | |
31 | struct dentry *dir); | |
32 | ||
33 | struct hypfs_sb_info { | |
34 | uid_t uid; /* uid used for files and dirs */ | |
35 | gid_t gid; /* gid used for files and dirs */ | |
36 | struct dentry *update_file; /* file to trigger update */ | |
37 | time_t last_update; /* last update time in secs since 1970 */ | |
38 | struct mutex lock; /* lock to protect update process */ | |
39 | }; | |
40 | ||
5dfe4c96 | 41 | static const struct file_operations hypfs_file_ops; |
24bbb1fa | 42 | static struct file_system_type hypfs_type; |
b87221de | 43 | static const struct super_operations hypfs_s_ops; |
24bbb1fa MH |
44 | |
45 | /* start of list of all dentries, which have to be deleted on update */ | |
46 | static struct dentry *hypfs_last_dentry; | |
47 | ||
48 | static void hypfs_update_update(struct super_block *sb) | |
49 | { | |
50 | struct hypfs_sb_info *sb_info = sb->s_fs_info; | |
51 | struct inode *inode = sb_info->update_file->d_inode; | |
52 | ||
53 | sb_info->last_update = get_seconds(); | |
54 | inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; | |
55 | } | |
56 | ||
57 | /* directory tree removal functions */ | |
58 | ||
59 | static void hypfs_add_dentry(struct dentry *dentry) | |
60 | { | |
61 | dentry->d_fsdata = hypfs_last_dentry; | |
62 | hypfs_last_dentry = dentry; | |
63 | } | |
64 | ||
9b5a03e1 MH |
65 | static inline int hypfs_positive(struct dentry *dentry) |
66 | { | |
67 | return dentry->d_inode && !d_unhashed(dentry); | |
68 | } | |
69 | ||
24bbb1fa MH |
70 | static void hypfs_remove(struct dentry *dentry) |
71 | { | |
72 | struct dentry *parent; | |
73 | ||
74 | parent = dentry->d_parent; | |
9b5a03e1 MH |
75 | if (!parent || !parent->d_inode) |
76 | return; | |
77 | mutex_lock(&parent->d_inode->i_mutex); | |
78 | if (hypfs_positive(dentry)) { | |
79 | if (S_ISDIR(dentry->d_inode->i_mode)) | |
80 | simple_rmdir(parent->d_inode, dentry); | |
81 | else | |
82 | simple_unlink(parent->d_inode, dentry); | |
83 | } | |
24bbb1fa MH |
84 | d_delete(dentry); |
85 | dput(dentry); | |
9b5a03e1 | 86 | mutex_unlock(&parent->d_inode->i_mutex); |
24bbb1fa MH |
87 | } |
88 | ||
89 | static void hypfs_delete_tree(struct dentry *root) | |
90 | { | |
91 | while (hypfs_last_dentry) { | |
92 | struct dentry *next_dentry; | |
93 | next_dentry = hypfs_last_dentry->d_fsdata; | |
94 | hypfs_remove(hypfs_last_dentry); | |
95 | hypfs_last_dentry = next_dentry; | |
96 | } | |
97 | } | |
98 | ||
fec0ebae | 99 | static struct inode *hypfs_make_inode(struct super_block *sb, umode_t mode) |
24bbb1fa MH |
100 | { |
101 | struct inode *ret = new_inode(sb); | |
102 | ||
103 | if (ret) { | |
104 | struct hypfs_sb_info *hypfs_info = sb->s_fs_info; | |
c960bec4 | 105 | ret->i_ino = get_next_ino(); |
24bbb1fa MH |
106 | ret->i_mode = mode; |
107 | ret->i_uid = hypfs_info->uid; | |
108 | ret->i_gid = hypfs_info->gid; | |
24bbb1fa | 109 | ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME; |
fec0ebae | 110 | if (S_ISDIR(mode)) |
bfe86848 | 111 | set_nlink(ret, 2); |
24bbb1fa MH |
112 | } |
113 | return ret; | |
114 | } | |
115 | ||
b69257f2 | 116 | static void hypfs_evict_inode(struct inode *inode) |
24bbb1fa | 117 | { |
dbd5768f | 118 | clear_inode(inode); |
8e18e294 | 119 | kfree(inode->i_private); |
24bbb1fa MH |
120 | } |
121 | ||
122 | static int hypfs_open(struct inode *inode, struct file *filp) | |
123 | { | |
d20343e7 | 124 | char *data = filp->f_path.dentry->d_inode->i_private; |
24bbb1fa MH |
125 | struct hypfs_sb_info *fs_info; |
126 | ||
127 | if (filp->f_mode & FMODE_WRITE) { | |
128 | if (!(inode->i_mode & S_IWUGO)) | |
129 | return -EACCES; | |
130 | } | |
131 | if (filp->f_mode & FMODE_READ) { | |
132 | if (!(inode->i_mode & S_IRUGO)) | |
133 | return -EACCES; | |
134 | } | |
135 | ||
136 | fs_info = inode->i_sb->s_fs_info; | |
137 | if(data) { | |
138 | mutex_lock(&fs_info->lock); | |
139 | filp->private_data = kstrdup(data, GFP_KERNEL); | |
140 | if (!filp->private_data) { | |
141 | mutex_unlock(&fs_info->lock); | |
142 | return -ENOMEM; | |
143 | } | |
144 | mutex_unlock(&fs_info->lock); | |
145 | } | |
58ea91c0 | 146 | return nonseekable_open(inode, filp); |
24bbb1fa MH |
147 | } |
148 | ||
027445c3 BP |
149 | static ssize_t hypfs_aio_read(struct kiocb *iocb, const struct iovec *iov, |
150 | unsigned long nr_segs, loff_t offset) | |
24bbb1fa MH |
151 | { |
152 | char *data; | |
a29591c4 | 153 | ssize_t ret; |
24bbb1fa | 154 | struct file *filp = iocb->ki_filp; |
027445c3 BP |
155 | /* XXX: temporary */ |
156 | char __user *buf = iov[0].iov_base; | |
157 | size_t count = iov[0].iov_len; | |
158 | ||
a29591c4 AM |
159 | if (nr_segs != 1) |
160 | return -EINVAL; | |
24bbb1fa MH |
161 | |
162 | data = filp->private_data; | |
a29591c4 AM |
163 | ret = simple_read_from_buffer(buf, count, &offset, data, strlen(data)); |
164 | if (ret <= 0) | |
165 | return ret; | |
166 | ||
167 | iocb->ki_pos += ret; | |
24bbb1fa | 168 | file_accessed(filp); |
a29591c4 AM |
169 | |
170 | return ret; | |
24bbb1fa | 171 | } |
027445c3 BP |
172 | static ssize_t hypfs_aio_write(struct kiocb *iocb, const struct iovec *iov, |
173 | unsigned long nr_segs, loff_t offset) | |
24bbb1fa MH |
174 | { |
175 | int rc; | |
176 | struct super_block *sb; | |
177 | struct hypfs_sb_info *fs_info; | |
027445c3 | 178 | size_t count = iov_length(iov, nr_segs); |
24bbb1fa | 179 | |
d20343e7 | 180 | sb = iocb->ki_filp->f_path.dentry->d_inode->i_sb; |
24bbb1fa MH |
181 | fs_info = sb->s_fs_info; |
182 | /* | |
183 | * Currently we only allow one update per second for two reasons: | |
184 | * 1. diag 204 is VERY expensive | |
185 | * 2. If several processes do updates in parallel and then read the | |
186 | * hypfs data, the likelihood of collisions is reduced, if we restrict | |
187 | * the minimum update interval. A collision occurs, if during the | |
188 | * data gathering of one process another process triggers an update | |
189 | * If the first process wants to ensure consistent data, it has | |
190 | * to restart data collection in this case. | |
191 | */ | |
192 | mutex_lock(&fs_info->lock); | |
193 | if (fs_info->last_update == get_seconds()) { | |
194 | rc = -EBUSY; | |
195 | goto out; | |
196 | } | |
197 | hypfs_delete_tree(sb->s_root); | |
31cb4bd3 MH |
198 | if (MACHINE_IS_VM) |
199 | rc = hypfs_vm_create_files(sb, sb->s_root); | |
200 | else | |
201 | rc = hypfs_diag_create_files(sb, sb->s_root); | |
24bbb1fa | 202 | if (rc) { |
f55495ba | 203 | pr_err("Updating the hypfs tree failed\n"); |
24bbb1fa MH |
204 | hypfs_delete_tree(sb->s_root); |
205 | goto out; | |
206 | } | |
207 | hypfs_update_update(sb); | |
208 | rc = count; | |
209 | out: | |
210 | mutex_unlock(&fs_info->lock); | |
211 | return rc; | |
212 | } | |
213 | ||
214 | static int hypfs_release(struct inode *inode, struct file *filp) | |
215 | { | |
216 | kfree(filp->private_data); | |
217 | return 0; | |
218 | } | |
219 | ||
220 | enum { opt_uid, opt_gid, opt_err }; | |
221 | ||
a447c093 | 222 | static const match_table_t hypfs_tokens = { |
24bbb1fa MH |
223 | {opt_uid, "uid=%u"}, |
224 | {opt_gid, "gid=%u"}, | |
225 | {opt_err, NULL} | |
226 | }; | |
227 | ||
228 | static int hypfs_parse_options(char *options, struct super_block *sb) | |
229 | { | |
230 | char *str; | |
231 | substring_t args[MAX_OPT_ARGS]; | |
232 | ||
233 | if (!options) | |
234 | return 0; | |
235 | while ((str = strsep(&options, ",")) != NULL) { | |
236 | int token, option; | |
237 | struct hypfs_sb_info *hypfs_info = sb->s_fs_info; | |
238 | ||
239 | if (!*str) | |
240 | continue; | |
241 | token = match_token(str, hypfs_tokens, args); | |
242 | switch (token) { | |
243 | case opt_uid: | |
244 | if (match_int(&args[0], &option)) | |
245 | return -EINVAL; | |
246 | hypfs_info->uid = option; | |
247 | break; | |
248 | case opt_gid: | |
249 | if (match_int(&args[0], &option)) | |
250 | return -EINVAL; | |
251 | hypfs_info->gid = option; | |
252 | break; | |
253 | case opt_err: | |
254 | default: | |
f55495ba | 255 | pr_err("%s is not a valid mount option\n", str); |
24bbb1fa MH |
256 | return -EINVAL; |
257 | } | |
258 | } | |
259 | return 0; | |
260 | } | |
261 | ||
34c80b1d | 262 | static int hypfs_show_options(struct seq_file *s, struct dentry *root) |
b01af5ba | 263 | { |
34c80b1d | 264 | struct hypfs_sb_info *hypfs_info = root->d_sb->s_fs_info; |
b01af5ba MH |
265 | |
266 | seq_printf(s, ",uid=%u", hypfs_info->uid); | |
267 | seq_printf(s, ",gid=%u", hypfs_info->gid); | |
268 | return 0; | |
269 | } | |
270 | ||
24bbb1fa MH |
271 | static int hypfs_fill_super(struct super_block *sb, void *data, int silent) |
272 | { | |
273 | struct inode *root_inode; | |
274 | struct dentry *root_dentry; | |
275 | int rc = 0; | |
276 | struct hypfs_sb_info *sbi; | |
277 | ||
278 | sbi = kzalloc(sizeof(struct hypfs_sb_info), GFP_KERNEL); | |
279 | if (!sbi) | |
280 | return -ENOMEM; | |
281 | mutex_init(&sbi->lock); | |
e5423705 DH |
282 | sbi->uid = current_uid(); |
283 | sbi->gid = current_gid(); | |
24bbb1fa MH |
284 | sb->s_fs_info = sbi; |
285 | sb->s_blocksize = PAGE_CACHE_SIZE; | |
286 | sb->s_blocksize_bits = PAGE_CACHE_SHIFT; | |
287 | sb->s_magic = HYPFS_MAGIC; | |
288 | sb->s_op = &hypfs_s_ops; | |
f1771ffa AV |
289 | if (hypfs_parse_options(data, sb)) |
290 | return -EINVAL; | |
24bbb1fa | 291 | root_inode = hypfs_make_inode(sb, S_IFDIR | 0755); |
f1771ffa AV |
292 | if (!root_inode) |
293 | return -ENOMEM; | |
24bbb1fa MH |
294 | root_inode->i_op = &simple_dir_inode_operations; |
295 | root_inode->i_fop = &simple_dir_operations; | |
48fde701 AV |
296 | sb->s_root = root_dentry = d_make_root(root_inode); |
297 | if (!root_dentry) | |
f1771ffa | 298 | return -ENOMEM; |
31cb4bd3 MH |
299 | if (MACHINE_IS_VM) |
300 | rc = hypfs_vm_create_files(sb, root_dentry); | |
301 | else | |
302 | rc = hypfs_diag_create_files(sb, root_dentry); | |
24bbb1fa | 303 | if (rc) |
f1771ffa | 304 | return rc; |
24bbb1fa | 305 | sbi->update_file = hypfs_create_update_file(sb, root_dentry); |
f1771ffa AV |
306 | if (IS_ERR(sbi->update_file)) |
307 | return PTR_ERR(sbi->update_file); | |
24bbb1fa | 308 | hypfs_update_update(sb); |
f55495ba | 309 | pr_info("Hypervisor filesystem mounted\n"); |
24bbb1fa | 310 | return 0; |
24bbb1fa MH |
311 | } |
312 | ||
fc14f2fe AV |
313 | static struct dentry *hypfs_mount(struct file_system_type *fst, int flags, |
314 | const char *devname, void *data) | |
24bbb1fa | 315 | { |
fc14f2fe | 316 | return mount_single(fst, flags, data, hypfs_fill_super); |
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 | ||
f1771ffa | 323 | if (sb->s_root) |
388c571c | 324 | hypfs_delete_tree(sb->s_root); |
f1771ffa | 325 | if (sb_info->update_file) |
388c571c | 326 | hypfs_remove(sb_info->update_file); |
f1771ffa AV |
327 | kfree(sb->s_fs_info); |
328 | sb->s_fs_info = NULL; | |
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, | |
fec0ebae | 334 | char *data, umode_t mode) |
24bbb1fa MH |
335 | { |
336 | struct dentry *dentry; | |
337 | struct inode *inode; | |
24bbb1fa | 338 | |
9b5a03e1 | 339 | mutex_lock(&parent->d_inode->i_mutex); |
24bbb1fa | 340 | dentry = lookup_one_len(name, parent, strlen(name)); |
9b5a03e1 MH |
341 | if (IS_ERR(dentry)) { |
342 | dentry = ERR_PTR(-ENOMEM); | |
343 | goto fail; | |
344 | } | |
24bbb1fa MH |
345 | inode = hypfs_make_inode(sb, mode); |
346 | if (!inode) { | |
347 | dput(dentry); | |
9b5a03e1 MH |
348 | dentry = ERR_PTR(-ENOMEM); |
349 | goto fail; | |
24bbb1fa | 350 | } |
fec0ebae | 351 | if (S_ISREG(mode)) { |
24bbb1fa MH |
352 | inode->i_fop = &hypfs_file_ops; |
353 | if (data) | |
354 | inode->i_size = strlen(data); | |
355 | else | |
356 | inode->i_size = 0; | |
fec0ebae | 357 | } else if (S_ISDIR(mode)) { |
24bbb1fa MH |
358 | inode->i_op = &simple_dir_inode_operations; |
359 | inode->i_fop = &simple_dir_operations; | |
6d6b77f1 | 360 | inc_nlink(parent->d_inode); |
24bbb1fa MH |
361 | } else |
362 | BUG(); | |
8e18e294 | 363 | inode->i_private = data; |
24bbb1fa MH |
364 | d_instantiate(dentry, inode); |
365 | dget(dentry); | |
9b5a03e1 MH |
366 | fail: |
367 | mutex_unlock(&parent->d_inode->i_mutex); | |
24bbb1fa MH |
368 | return dentry; |
369 | } | |
370 | ||
371 | struct dentry *hypfs_mkdir(struct super_block *sb, struct dentry *parent, | |
372 | const char *name) | |
373 | { | |
374 | struct dentry *dentry; | |
375 | ||
376 | dentry = hypfs_create_file(sb, parent, name, NULL, S_IFDIR | DIR_MODE); | |
377 | if (IS_ERR(dentry)) | |
378 | return dentry; | |
379 | hypfs_add_dentry(dentry); | |
24bbb1fa MH |
380 | return dentry; |
381 | } | |
382 | ||
383 | static struct dentry *hypfs_create_update_file(struct super_block *sb, | |
384 | struct dentry *dir) | |
385 | { | |
386 | struct dentry *dentry; | |
387 | ||
388 | dentry = hypfs_create_file(sb, dir, "update", NULL, | |
389 | S_IFREG | UPDATE_FILE_MODE); | |
390 | /* | |
391 | * We do not put the update file on the 'delete' list with | |
392 | * hypfs_add_dentry(), since it should not be removed when the tree | |
393 | * is updated. | |
394 | */ | |
395 | return dentry; | |
396 | } | |
397 | ||
398 | struct dentry *hypfs_create_u64(struct super_block *sb, struct dentry *dir, | |
399 | const char *name, __u64 value) | |
400 | { | |
401 | char *buffer; | |
402 | char tmp[TMP_SIZE]; | |
403 | struct dentry *dentry; | |
404 | ||
ad2a5d8e | 405 | snprintf(tmp, TMP_SIZE, "%llu\n", (unsigned long long int)value); |
24bbb1fa MH |
406 | buffer = kstrdup(tmp, GFP_KERNEL); |
407 | if (!buffer) | |
408 | return ERR_PTR(-ENOMEM); | |
409 | dentry = | |
410 | hypfs_create_file(sb, dir, name, buffer, S_IFREG | REG_FILE_MODE); | |
411 | if (IS_ERR(dentry)) { | |
412 | kfree(buffer); | |
413 | return ERR_PTR(-ENOMEM); | |
414 | } | |
415 | hypfs_add_dentry(dentry); | |
416 | return dentry; | |
417 | } | |
418 | ||
419 | struct dentry *hypfs_create_str(struct super_block *sb, struct dentry *dir, | |
420 | const char *name, char *string) | |
421 | { | |
422 | char *buffer; | |
423 | struct dentry *dentry; | |
424 | ||
425 | buffer = kmalloc(strlen(string) + 2, GFP_KERNEL); | |
426 | if (!buffer) | |
427 | return ERR_PTR(-ENOMEM); | |
428 | sprintf(buffer, "%s\n", string); | |
429 | dentry = | |
430 | hypfs_create_file(sb, dir, name, buffer, S_IFREG | REG_FILE_MODE); | |
431 | if (IS_ERR(dentry)) { | |
432 | kfree(buffer); | |
433 | return ERR_PTR(-ENOMEM); | |
434 | } | |
435 | hypfs_add_dentry(dentry); | |
436 | return dentry; | |
437 | } | |
438 | ||
5dfe4c96 | 439 | static const struct file_operations hypfs_file_ops = { |
24bbb1fa MH |
440 | .open = hypfs_open, |
441 | .release = hypfs_release, | |
442 | .read = do_sync_read, | |
443 | .write = do_sync_write, | |
444 | .aio_read = hypfs_aio_read, | |
445 | .aio_write = hypfs_aio_write, | |
6038f373 | 446 | .llseek = no_llseek, |
24bbb1fa MH |
447 | }; |
448 | ||
449 | static struct file_system_type hypfs_type = { | |
450 | .owner = THIS_MODULE, | |
451 | .name = "s390_hypfs", | |
fc14f2fe | 452 | .mount = hypfs_mount, |
24bbb1fa MH |
453 | .kill_sb = hypfs_kill_super |
454 | }; | |
455 | ||
b87221de | 456 | static const struct super_operations hypfs_s_ops = { |
24bbb1fa | 457 | .statfs = simple_statfs, |
b69257f2 | 458 | .evict_inode = hypfs_evict_inode, |
b01af5ba | 459 | .show_options = hypfs_show_options, |
24bbb1fa MH |
460 | }; |
461 | ||
9b477705 | 462 | static struct kobject *s390_kobj; |
24bbb1fa MH |
463 | |
464 | static int __init hypfs_init(void) | |
465 | { | |
466 | int rc; | |
467 | ||
2fcb3686 MH |
468 | rc = hypfs_dbfs_init(); |
469 | if (rc) | |
470 | return rc; | |
57b28f66 MH |
471 | if (hypfs_diag_init()) { |
472 | rc = -ENODATA; | |
2fcb3686 | 473 | goto fail_dbfs_exit; |
57b28f66 MH |
474 | } |
475 | if (hypfs_vm_init()) { | |
476 | rc = -ENODATA; | |
477 | goto fail_hypfs_diag_exit; | |
24bbb1fa | 478 | } |
9b477705 GKH |
479 | s390_kobj = kobject_create_and_add("s390", hypervisor_kobj); |
480 | if (!s390_kobj) { | |
a419aef8 | 481 | rc = -ENOMEM; |
57b28f66 | 482 | goto fail_hypfs_vm_exit; |
9b477705 | 483 | } |
24bbb1fa MH |
484 | rc = register_filesystem(&hypfs_type); |
485 | if (rc) | |
486 | goto fail_filesystem; | |
487 | return 0; | |
488 | ||
489 | fail_filesystem: | |
38a382ae | 490 | kobject_put(s390_kobj); |
57b28f66 MH |
491 | fail_hypfs_vm_exit: |
492 | hypfs_vm_exit(); | |
493 | fail_hypfs_diag_exit: | |
494 | hypfs_diag_exit(); | |
2fcb3686 MH |
495 | fail_dbfs_exit: |
496 | hypfs_dbfs_exit(); | |
f55495ba | 497 | pr_err("Initialization of hypfs failed with rc=%i\n", rc); |
24bbb1fa MH |
498 | return rc; |
499 | } | |
500 | ||
501 | static void __exit hypfs_exit(void) | |
502 | { | |
57b28f66 MH |
503 | hypfs_diag_exit(); |
504 | hypfs_vm_exit(); | |
2fcb3686 | 505 | hypfs_dbfs_exit(); |
24bbb1fa | 506 | unregister_filesystem(&hypfs_type); |
38a382ae | 507 | kobject_put(s390_kobj); |
24bbb1fa MH |
508 | } |
509 | ||
510 | module_init(hypfs_init) | |
511 | module_exit(hypfs_exit) | |
512 | ||
513 | MODULE_LICENSE("GPL"); | |
514 | MODULE_AUTHOR("Michael Holzheu <holzheu@de.ibm.com>"); | |
515 | MODULE_DESCRIPTION("s390 Hypervisor Filesystem"); |