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> | |
5a0e3ad6 | 17 | #include <linux/slab.h> |
24bbb1fa | 18 | #include <linux/pagemap.h> |
24bbb1fa MH |
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 | 43 | static struct file_system_type hypfs_type; |
b87221de | 44 | static const struct super_operations hypfs_s_ops; |
24bbb1fa MH |
45 | |
46 | /* start of list of all dentries, which have to be deleted on update */ | |
47 | static struct dentry *hypfs_last_dentry; | |
48 | ||
57b28f66 MH |
49 | struct dentry *hypfs_dbfs_dir; |
50 | ||
24bbb1fa MH |
51 | static void hypfs_update_update(struct super_block *sb) |
52 | { | |
53 | struct hypfs_sb_info *sb_info = sb->s_fs_info; | |
54 | struct inode *inode = sb_info->update_file->d_inode; | |
55 | ||
56 | sb_info->last_update = get_seconds(); | |
57 | inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; | |
58 | } | |
59 | ||
60 | /* directory tree removal functions */ | |
61 | ||
62 | static void hypfs_add_dentry(struct dentry *dentry) | |
63 | { | |
64 | dentry->d_fsdata = hypfs_last_dentry; | |
65 | hypfs_last_dentry = dentry; | |
66 | } | |
67 | ||
9b5a03e1 MH |
68 | static inline int hypfs_positive(struct dentry *dentry) |
69 | { | |
70 | return dentry->d_inode && !d_unhashed(dentry); | |
71 | } | |
72 | ||
24bbb1fa MH |
73 | static void hypfs_remove(struct dentry *dentry) |
74 | { | |
75 | struct dentry *parent; | |
76 | ||
77 | parent = dentry->d_parent; | |
9b5a03e1 MH |
78 | if (!parent || !parent->d_inode) |
79 | return; | |
80 | mutex_lock(&parent->d_inode->i_mutex); | |
81 | if (hypfs_positive(dentry)) { | |
82 | if (S_ISDIR(dentry->d_inode->i_mode)) | |
83 | simple_rmdir(parent->d_inode, dentry); | |
84 | else | |
85 | simple_unlink(parent->d_inode, dentry); | |
86 | } | |
24bbb1fa MH |
87 | d_delete(dentry); |
88 | dput(dentry); | |
9b5a03e1 | 89 | mutex_unlock(&parent->d_inode->i_mutex); |
24bbb1fa MH |
90 | } |
91 | ||
92 | static void hypfs_delete_tree(struct dentry *root) | |
93 | { | |
94 | while (hypfs_last_dentry) { | |
95 | struct dentry *next_dentry; | |
96 | next_dentry = hypfs_last_dentry->d_fsdata; | |
97 | hypfs_remove(hypfs_last_dentry); | |
98 | hypfs_last_dentry = next_dentry; | |
99 | } | |
100 | } | |
101 | ||
102 | static struct inode *hypfs_make_inode(struct super_block *sb, int mode) | |
103 | { | |
104 | struct inode *ret = new_inode(sb); | |
105 | ||
106 | if (ret) { | |
107 | struct hypfs_sb_info *hypfs_info = sb->s_fs_info; | |
108 | ret->i_mode = mode; | |
109 | ret->i_uid = hypfs_info->uid; | |
110 | ret->i_gid = hypfs_info->gid; | |
24bbb1fa MH |
111 | ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME; |
112 | if (mode & S_IFDIR) | |
113 | ret->i_nlink = 2; | |
114 | else | |
115 | ret->i_nlink = 1; | |
116 | } | |
117 | return ret; | |
118 | } | |
119 | ||
b69257f2 | 120 | static void hypfs_evict_inode(struct inode *inode) |
24bbb1fa | 121 | { |
b69257f2 | 122 | end_writeback(inode); |
8e18e294 | 123 | kfree(inode->i_private); |
24bbb1fa MH |
124 | } |
125 | ||
126 | static int hypfs_open(struct inode *inode, struct file *filp) | |
127 | { | |
d20343e7 | 128 | char *data = filp->f_path.dentry->d_inode->i_private; |
24bbb1fa MH |
129 | struct hypfs_sb_info *fs_info; |
130 | ||
131 | if (filp->f_mode & FMODE_WRITE) { | |
132 | if (!(inode->i_mode & S_IWUGO)) | |
133 | return -EACCES; | |
134 | } | |
135 | if (filp->f_mode & FMODE_READ) { | |
136 | if (!(inode->i_mode & S_IRUGO)) | |
137 | return -EACCES; | |
138 | } | |
139 | ||
140 | fs_info = inode->i_sb->s_fs_info; | |
141 | if(data) { | |
142 | mutex_lock(&fs_info->lock); | |
143 | filp->private_data = kstrdup(data, GFP_KERNEL); | |
144 | if (!filp->private_data) { | |
145 | mutex_unlock(&fs_info->lock); | |
146 | return -ENOMEM; | |
147 | } | |
148 | mutex_unlock(&fs_info->lock); | |
149 | } | |
58ea91c0 | 150 | return nonseekable_open(inode, filp); |
24bbb1fa MH |
151 | } |
152 | ||
027445c3 BP |
153 | static ssize_t hypfs_aio_read(struct kiocb *iocb, const struct iovec *iov, |
154 | unsigned long nr_segs, loff_t offset) | |
24bbb1fa MH |
155 | { |
156 | char *data; | |
a29591c4 | 157 | ssize_t ret; |
24bbb1fa | 158 | struct file *filp = iocb->ki_filp; |
027445c3 BP |
159 | /* XXX: temporary */ |
160 | char __user *buf = iov[0].iov_base; | |
161 | size_t count = iov[0].iov_len; | |
162 | ||
a29591c4 AM |
163 | if (nr_segs != 1) |
164 | return -EINVAL; | |
24bbb1fa MH |
165 | |
166 | data = filp->private_data; | |
a29591c4 AM |
167 | ret = simple_read_from_buffer(buf, count, &offset, data, strlen(data)); |
168 | if (ret <= 0) | |
169 | return ret; | |
170 | ||
171 | iocb->ki_pos += ret; | |
24bbb1fa | 172 | file_accessed(filp); |
a29591c4 AM |
173 | |
174 | return ret; | |
24bbb1fa | 175 | } |
027445c3 BP |
176 | static ssize_t hypfs_aio_write(struct kiocb *iocb, const struct iovec *iov, |
177 | unsigned long nr_segs, loff_t offset) | |
24bbb1fa MH |
178 | { |
179 | int rc; | |
180 | struct super_block *sb; | |
181 | struct hypfs_sb_info *fs_info; | |
027445c3 | 182 | size_t count = iov_length(iov, nr_segs); |
24bbb1fa | 183 | |
d20343e7 | 184 | sb = iocb->ki_filp->f_path.dentry->d_inode->i_sb; |
24bbb1fa MH |
185 | fs_info = sb->s_fs_info; |
186 | /* | |
187 | * Currently we only allow one update per second for two reasons: | |
188 | * 1. diag 204 is VERY expensive | |
189 | * 2. If several processes do updates in parallel and then read the | |
190 | * hypfs data, the likelihood of collisions is reduced, if we restrict | |
191 | * the minimum update interval. A collision occurs, if during the | |
192 | * data gathering of one process another process triggers an update | |
193 | * If the first process wants to ensure consistent data, it has | |
194 | * to restart data collection in this case. | |
195 | */ | |
196 | mutex_lock(&fs_info->lock); | |
197 | if (fs_info->last_update == get_seconds()) { | |
198 | rc = -EBUSY; | |
199 | goto out; | |
200 | } | |
201 | hypfs_delete_tree(sb->s_root); | |
31cb4bd3 MH |
202 | if (MACHINE_IS_VM) |
203 | rc = hypfs_vm_create_files(sb, sb->s_root); | |
204 | else | |
205 | rc = hypfs_diag_create_files(sb, sb->s_root); | |
24bbb1fa | 206 | if (rc) { |
f55495ba | 207 | pr_err("Updating the hypfs tree failed\n"); |
24bbb1fa MH |
208 | hypfs_delete_tree(sb->s_root); |
209 | goto out; | |
210 | } | |
211 | hypfs_update_update(sb); | |
212 | rc = count; | |
213 | out: | |
214 | mutex_unlock(&fs_info->lock); | |
215 | return rc; | |
216 | } | |
217 | ||
218 | static int hypfs_release(struct inode *inode, struct file *filp) | |
219 | { | |
220 | kfree(filp->private_data); | |
221 | return 0; | |
222 | } | |
223 | ||
224 | enum { opt_uid, opt_gid, opt_err }; | |
225 | ||
a447c093 | 226 | static const match_table_t hypfs_tokens = { |
24bbb1fa MH |
227 | {opt_uid, "uid=%u"}, |
228 | {opt_gid, "gid=%u"}, | |
229 | {opt_err, NULL} | |
230 | }; | |
231 | ||
232 | static int hypfs_parse_options(char *options, struct super_block *sb) | |
233 | { | |
234 | char *str; | |
235 | substring_t args[MAX_OPT_ARGS]; | |
236 | ||
237 | if (!options) | |
238 | return 0; | |
239 | while ((str = strsep(&options, ",")) != NULL) { | |
240 | int token, option; | |
241 | struct hypfs_sb_info *hypfs_info = sb->s_fs_info; | |
242 | ||
243 | if (!*str) | |
244 | continue; | |
245 | token = match_token(str, hypfs_tokens, args); | |
246 | switch (token) { | |
247 | case opt_uid: | |
248 | if (match_int(&args[0], &option)) | |
249 | return -EINVAL; | |
250 | hypfs_info->uid = option; | |
251 | break; | |
252 | case opt_gid: | |
253 | if (match_int(&args[0], &option)) | |
254 | return -EINVAL; | |
255 | hypfs_info->gid = option; | |
256 | break; | |
257 | case opt_err: | |
258 | default: | |
f55495ba | 259 | pr_err("%s is not a valid mount option\n", str); |
24bbb1fa MH |
260 | return -EINVAL; |
261 | } | |
262 | } | |
263 | return 0; | |
264 | } | |
265 | ||
b01af5ba MH |
266 | static int hypfs_show_options(struct seq_file *s, struct vfsmount *mnt) |
267 | { | |
268 | struct hypfs_sb_info *hypfs_info = mnt->mnt_sb->s_fs_info; | |
269 | ||
270 | seq_printf(s, ",uid=%u", hypfs_info->uid); | |
271 | seq_printf(s, ",gid=%u", hypfs_info->gid); | |
272 | return 0; | |
273 | } | |
274 | ||
24bbb1fa MH |
275 | static int hypfs_fill_super(struct super_block *sb, void *data, int silent) |
276 | { | |
277 | struct inode *root_inode; | |
278 | struct dentry *root_dentry; | |
279 | int rc = 0; | |
280 | struct hypfs_sb_info *sbi; | |
281 | ||
282 | sbi = kzalloc(sizeof(struct hypfs_sb_info), GFP_KERNEL); | |
283 | if (!sbi) | |
284 | return -ENOMEM; | |
285 | mutex_init(&sbi->lock); | |
e5423705 DH |
286 | sbi->uid = current_uid(); |
287 | sbi->gid = current_gid(); | |
24bbb1fa MH |
288 | sb->s_fs_info = sbi; |
289 | sb->s_blocksize = PAGE_CACHE_SIZE; | |
290 | sb->s_blocksize_bits = PAGE_CACHE_SHIFT; | |
291 | sb->s_magic = HYPFS_MAGIC; | |
292 | sb->s_op = &hypfs_s_ops; | |
f1771ffa AV |
293 | if (hypfs_parse_options(data, sb)) |
294 | return -EINVAL; | |
24bbb1fa | 295 | root_inode = hypfs_make_inode(sb, S_IFDIR | 0755); |
f1771ffa AV |
296 | if (!root_inode) |
297 | return -ENOMEM; | |
24bbb1fa MH |
298 | root_inode->i_op = &simple_dir_inode_operations; |
299 | root_inode->i_fop = &simple_dir_operations; | |
f1771ffa | 300 | sb->s_root = root_dentry = d_alloc_root(root_inode); |
24bbb1fa MH |
301 | if (!root_dentry) { |
302 | iput(root_inode); | |
f1771ffa | 303 | return -ENOMEM; |
24bbb1fa | 304 | } |
31cb4bd3 MH |
305 | if (MACHINE_IS_VM) |
306 | rc = hypfs_vm_create_files(sb, root_dentry); | |
307 | else | |
308 | rc = hypfs_diag_create_files(sb, root_dentry); | |
24bbb1fa | 309 | if (rc) |
f1771ffa | 310 | return rc; |
24bbb1fa | 311 | sbi->update_file = hypfs_create_update_file(sb, root_dentry); |
f1771ffa AV |
312 | if (IS_ERR(sbi->update_file)) |
313 | return PTR_ERR(sbi->update_file); | |
24bbb1fa | 314 | hypfs_update_update(sb); |
f55495ba | 315 | pr_info("Hypervisor filesystem mounted\n"); |
24bbb1fa | 316 | return 0; |
24bbb1fa MH |
317 | } |
318 | ||
a5cf4b9a AM |
319 | static int hypfs_get_super(struct file_system_type *fst, int flags, |
320 | const char *devname, void *data, struct vfsmount *mnt) | |
24bbb1fa | 321 | { |
a5cf4b9a | 322 | return get_sb_single(fst, flags, data, hypfs_fill_super, mnt); |
24bbb1fa MH |
323 | } |
324 | ||
325 | static void hypfs_kill_super(struct super_block *sb) | |
326 | { | |
327 | struct hypfs_sb_info *sb_info = sb->s_fs_info; | |
328 | ||
f1771ffa | 329 | if (sb->s_root) |
388c571c | 330 | hypfs_delete_tree(sb->s_root); |
f1771ffa | 331 | if (sb_info->update_file) |
388c571c | 332 | hypfs_remove(sb_info->update_file); |
f1771ffa AV |
333 | kfree(sb->s_fs_info); |
334 | sb->s_fs_info = NULL; | |
24bbb1fa MH |
335 | kill_litter_super(sb); |
336 | } | |
337 | ||
338 | static struct dentry *hypfs_create_file(struct super_block *sb, | |
339 | struct dentry *parent, const char *name, | |
340 | char *data, mode_t mode) | |
341 | { | |
342 | struct dentry *dentry; | |
343 | struct inode *inode; | |
24bbb1fa | 344 | |
9b5a03e1 | 345 | mutex_lock(&parent->d_inode->i_mutex); |
24bbb1fa | 346 | dentry = lookup_one_len(name, parent, strlen(name)); |
9b5a03e1 MH |
347 | if (IS_ERR(dentry)) { |
348 | dentry = ERR_PTR(-ENOMEM); | |
349 | goto fail; | |
350 | } | |
24bbb1fa MH |
351 | inode = hypfs_make_inode(sb, mode); |
352 | if (!inode) { | |
353 | dput(dentry); | |
9b5a03e1 MH |
354 | dentry = ERR_PTR(-ENOMEM); |
355 | goto fail; | |
24bbb1fa MH |
356 | } |
357 | if (mode & S_IFREG) { | |
358 | inode->i_fop = &hypfs_file_ops; | |
359 | if (data) | |
360 | inode->i_size = strlen(data); | |
361 | else | |
362 | inode->i_size = 0; | |
363 | } else if (mode & S_IFDIR) { | |
364 | inode->i_op = &simple_dir_inode_operations; | |
365 | inode->i_fop = &simple_dir_operations; | |
366 | parent->d_inode->i_nlink++; | |
367 | } else | |
368 | BUG(); | |
8e18e294 | 369 | inode->i_private = data; |
24bbb1fa MH |
370 | d_instantiate(dentry, inode); |
371 | dget(dentry); | |
9b5a03e1 MH |
372 | fail: |
373 | mutex_unlock(&parent->d_inode->i_mutex); | |
24bbb1fa MH |
374 | return dentry; |
375 | } | |
376 | ||
377 | struct dentry *hypfs_mkdir(struct super_block *sb, struct dentry *parent, | |
378 | const char *name) | |
379 | { | |
380 | struct dentry *dentry; | |
381 | ||
382 | dentry = hypfs_create_file(sb, parent, name, NULL, S_IFDIR | DIR_MODE); | |
383 | if (IS_ERR(dentry)) | |
384 | return dentry; | |
385 | hypfs_add_dentry(dentry); | |
24bbb1fa MH |
386 | return dentry; |
387 | } | |
388 | ||
389 | static struct dentry *hypfs_create_update_file(struct super_block *sb, | |
390 | struct dentry *dir) | |
391 | { | |
392 | struct dentry *dentry; | |
393 | ||
394 | dentry = hypfs_create_file(sb, dir, "update", NULL, | |
395 | S_IFREG | UPDATE_FILE_MODE); | |
396 | /* | |
397 | * We do not put the update file on the 'delete' list with | |
398 | * hypfs_add_dentry(), since it should not be removed when the tree | |
399 | * is updated. | |
400 | */ | |
401 | return dentry; | |
402 | } | |
403 | ||
404 | struct dentry *hypfs_create_u64(struct super_block *sb, struct dentry *dir, | |
405 | const char *name, __u64 value) | |
406 | { | |
407 | char *buffer; | |
408 | char tmp[TMP_SIZE]; | |
409 | struct dentry *dentry; | |
410 | ||
ad2a5d8e | 411 | snprintf(tmp, TMP_SIZE, "%llu\n", (unsigned long long int)value); |
24bbb1fa MH |
412 | buffer = kstrdup(tmp, GFP_KERNEL); |
413 | if (!buffer) | |
414 | return ERR_PTR(-ENOMEM); | |
415 | dentry = | |
416 | hypfs_create_file(sb, dir, name, buffer, S_IFREG | REG_FILE_MODE); | |
417 | if (IS_ERR(dentry)) { | |
418 | kfree(buffer); | |
419 | return ERR_PTR(-ENOMEM); | |
420 | } | |
421 | hypfs_add_dentry(dentry); | |
422 | return dentry; | |
423 | } | |
424 | ||
425 | struct dentry *hypfs_create_str(struct super_block *sb, struct dentry *dir, | |
426 | const char *name, char *string) | |
427 | { | |
428 | char *buffer; | |
429 | struct dentry *dentry; | |
430 | ||
431 | buffer = kmalloc(strlen(string) + 2, GFP_KERNEL); | |
432 | if (!buffer) | |
433 | return ERR_PTR(-ENOMEM); | |
434 | sprintf(buffer, "%s\n", string); | |
435 | dentry = | |
436 | hypfs_create_file(sb, dir, name, buffer, S_IFREG | REG_FILE_MODE); | |
437 | if (IS_ERR(dentry)) { | |
438 | kfree(buffer); | |
439 | return ERR_PTR(-ENOMEM); | |
440 | } | |
441 | hypfs_add_dentry(dentry); | |
442 | return dentry; | |
443 | } | |
444 | ||
5dfe4c96 | 445 | static const struct file_operations hypfs_file_ops = { |
24bbb1fa MH |
446 | .open = hypfs_open, |
447 | .release = hypfs_release, | |
448 | .read = do_sync_read, | |
449 | .write = do_sync_write, | |
450 | .aio_read = hypfs_aio_read, | |
451 | .aio_write = hypfs_aio_write, | |
452 | }; | |
453 | ||
454 | static struct file_system_type hypfs_type = { | |
455 | .owner = THIS_MODULE, | |
456 | .name = "s390_hypfs", | |
457 | .get_sb = hypfs_get_super, | |
458 | .kill_sb = hypfs_kill_super | |
459 | }; | |
460 | ||
b87221de | 461 | static const struct super_operations hypfs_s_ops = { |
24bbb1fa | 462 | .statfs = simple_statfs, |
b69257f2 | 463 | .evict_inode = hypfs_evict_inode, |
b01af5ba | 464 | .show_options = hypfs_show_options, |
24bbb1fa MH |
465 | }; |
466 | ||
9b477705 | 467 | static struct kobject *s390_kobj; |
24bbb1fa MH |
468 | |
469 | static int __init hypfs_init(void) | |
470 | { | |
471 | int rc; | |
472 | ||
57b28f66 MH |
473 | hypfs_dbfs_dir = debugfs_create_dir("s390_hypfs", NULL); |
474 | if (IS_ERR(hypfs_dbfs_dir)) | |
475 | return PTR_ERR(hypfs_dbfs_dir); | |
476 | ||
477 | if (hypfs_diag_init()) { | |
478 | rc = -ENODATA; | |
479 | goto fail_debugfs_remove; | |
480 | } | |
481 | if (hypfs_vm_init()) { | |
482 | rc = -ENODATA; | |
483 | goto fail_hypfs_diag_exit; | |
24bbb1fa | 484 | } |
9b477705 GKH |
485 | s390_kobj = kobject_create_and_add("s390", hypervisor_kobj); |
486 | if (!s390_kobj) { | |
a419aef8 | 487 | rc = -ENOMEM; |
57b28f66 | 488 | goto fail_hypfs_vm_exit; |
9b477705 | 489 | } |
24bbb1fa MH |
490 | rc = register_filesystem(&hypfs_type); |
491 | if (rc) | |
492 | goto fail_filesystem; | |
493 | return 0; | |
494 | ||
495 | fail_filesystem: | |
38a382ae | 496 | kobject_put(s390_kobj); |
57b28f66 MH |
497 | fail_hypfs_vm_exit: |
498 | hypfs_vm_exit(); | |
499 | fail_hypfs_diag_exit: | |
500 | hypfs_diag_exit(); | |
501 | fail_debugfs_remove: | |
502 | debugfs_remove(hypfs_dbfs_dir); | |
503 | ||
f55495ba | 504 | pr_err("Initialization of hypfs failed with rc=%i\n", rc); |
24bbb1fa MH |
505 | return rc; |
506 | } | |
507 | ||
508 | static void __exit hypfs_exit(void) | |
509 | { | |
57b28f66 MH |
510 | hypfs_diag_exit(); |
511 | hypfs_vm_exit(); | |
512 | debugfs_remove(hypfs_dbfs_dir); | |
24bbb1fa | 513 | unregister_filesystem(&hypfs_type); |
38a382ae | 514 | kobject_put(s390_kobj); |
24bbb1fa MH |
515 | } |
516 | ||
517 | module_init(hypfs_init) | |
518 | module_exit(hypfs_exit) | |
519 | ||
520 | MODULE_LICENSE("GPL"); | |
521 | MODULE_AUTHOR("Michael Holzheu <holzheu@de.ibm.com>"); | |
522 | MODULE_DESCRIPTION("s390 Hypervisor Filesystem"); |