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8#define KMSG_COMPONENT "hypfs"
9#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
10
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>
16#include <linux/slab.h>
17#include <linux/pagemap.h>
18#include <linux/time.h>
19#include <linux/parser.h>
20#include <linux/sysfs.h>
21#include <linux/module.h>
22#include <linux/seq_file.h>
23#include <linux/mount.h>
24#include <linux/uio.h>
25#include <asm/ebcdic.h>
26#include "hypfs.h"
27
28#define HYPFS_MAGIC 0x687970
29#define TMP_SIZE 64
30
31static struct dentry *hypfs_create_update_file(struct dentry *dir);
32
33struct hypfs_sb_info {
34 kuid_t uid;
35 kgid_t gid;
36 struct dentry *update_file;
37 time_t last_update;
38 struct mutex lock;
39};
40
41static const struct file_operations hypfs_file_ops;
42static struct file_system_type hypfs_type;
43static const struct super_operations hypfs_s_ops;
44
45
46static struct dentry *hypfs_last_dentry;
47
48static void hypfs_update_update(struct super_block *sb)
49{
50 struct hypfs_sb_info *sb_info = sb->s_fs_info;
51 struct inode *inode = d_inode(sb_info->update_file);
52
53 sb_info->last_update = get_seconds();
54 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
55}
56
57
58
59static void hypfs_add_dentry(struct dentry *dentry)
60{
61 dentry->d_fsdata = hypfs_last_dentry;
62 hypfs_last_dentry = dentry;
63}
64
65static inline int hypfs_positive(struct dentry *dentry)
66{
67 return d_really_is_positive(dentry) && !d_unhashed(dentry);
68}
69
70static void hypfs_remove(struct dentry *dentry)
71{
72 struct dentry *parent;
73
74 parent = dentry->d_parent;
75 mutex_lock(&d_inode(parent)->i_mutex);
76 if (hypfs_positive(dentry)) {
77 if (d_is_dir(dentry))
78 simple_rmdir(d_inode(parent), dentry);
79 else
80 simple_unlink(d_inode(parent), dentry);
81 }
82 d_delete(dentry);
83 dput(dentry);
84 mutex_unlock(&d_inode(parent)->i_mutex);
85}
86
87static void hypfs_delete_tree(struct dentry *root)
88{
89 while (hypfs_last_dentry) {
90 struct dentry *next_dentry;
91 next_dentry = hypfs_last_dentry->d_fsdata;
92 hypfs_remove(hypfs_last_dentry);
93 hypfs_last_dentry = next_dentry;
94 }
95}
96
97static struct inode *hypfs_make_inode(struct super_block *sb, umode_t mode)
98{
99 struct inode *ret = new_inode(sb);
100
101 if (ret) {
102 struct hypfs_sb_info *hypfs_info = sb->s_fs_info;
103 ret->i_ino = get_next_ino();
104 ret->i_mode = mode;
105 ret->i_uid = hypfs_info->uid;
106 ret->i_gid = hypfs_info->gid;
107 ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME;
108 if (S_ISDIR(mode))
109 set_nlink(ret, 2);
110 }
111 return ret;
112}
113
114static void hypfs_evict_inode(struct inode *inode)
115{
116 clear_inode(inode);
117 kfree(inode->i_private);
118}
119
120static int hypfs_open(struct inode *inode, struct file *filp)
121{
122 char *data = file_inode(filp)->i_private;
123 struct hypfs_sb_info *fs_info;
124
125 if (filp->f_mode & FMODE_WRITE) {
126 if (!(inode->i_mode & S_IWUGO))
127 return -EACCES;
128 }
129 if (filp->f_mode & FMODE_READ) {
130 if (!(inode->i_mode & S_IRUGO))
131 return -EACCES;
132 }
133
134 fs_info = inode->i_sb->s_fs_info;
135 if(data) {
136 mutex_lock(&fs_info->lock);
137 filp->private_data = kstrdup(data, GFP_KERNEL);
138 if (!filp->private_data) {
139 mutex_unlock(&fs_info->lock);
140 return -ENOMEM;
141 }
142 mutex_unlock(&fs_info->lock);
143 }
144 return nonseekable_open(inode, filp);
145}
146
147static ssize_t hypfs_read_iter(struct kiocb *iocb, struct iov_iter *to)
148{
149 struct file *file = iocb->ki_filp;
150 char *data = file->private_data;
151 size_t available = strlen(data);
152 loff_t pos = iocb->ki_pos;
153 size_t count;
154
155 if (pos < 0)
156 return -EINVAL;
157 if (pos >= available || !iov_iter_count(to))
158 return 0;
159 count = copy_to_iter(data + pos, available - pos, to);
160 if (!count)
161 return -EFAULT;
162 iocb->ki_pos = pos + count;
163 file_accessed(file);
164 return count;
165}
166
167static ssize_t hypfs_write_iter(struct kiocb *iocb, struct iov_iter *from)
168{
169 int rc;
170 struct super_block *sb = file_inode(iocb->ki_filp)->i_sb;
171 struct hypfs_sb_info *fs_info = sb->s_fs_info;
172 size_t count = iov_iter_count(from);
173
174
175
176
177
178
179
180
181
182
183
184 mutex_lock(&fs_info->lock);
185 if (fs_info->last_update == get_seconds()) {
186 rc = -EBUSY;
187 goto out;
188 }
189 hypfs_delete_tree(sb->s_root);
190 if (MACHINE_IS_VM)
191 rc = hypfs_vm_create_files(sb->s_root);
192 else
193 rc = hypfs_diag_create_files(sb->s_root);
194 if (rc) {
195 pr_err("Updating the hypfs tree failed\n");
196 hypfs_delete_tree(sb->s_root);
197 goto out;
198 }
199 hypfs_update_update(sb);
200 rc = count;
201 iov_iter_advance(from, count);
202out:
203 mutex_unlock(&fs_info->lock);
204 return rc;
205}
206
207static int hypfs_release(struct inode *inode, struct file *filp)
208{
209 kfree(filp->private_data);
210 return 0;
211}
212
213enum { opt_uid, opt_gid, opt_err };
214
215static const match_table_t hypfs_tokens = {
216 {opt_uid, "uid=%u"},
217 {opt_gid, "gid=%u"},
218 {opt_err, NULL}
219};
220
221static int hypfs_parse_options(char *options, struct super_block *sb)
222{
223 char *str;
224 substring_t args[MAX_OPT_ARGS];
225 kuid_t uid;
226 kgid_t gid;
227
228 if (!options)
229 return 0;
230 while ((str = strsep(&options, ",")) != NULL) {
231 int token, option;
232 struct hypfs_sb_info *hypfs_info = sb->s_fs_info;
233
234 if (!*str)
235 continue;
236 token = match_token(str, hypfs_tokens, args);
237 switch (token) {
238 case opt_uid:
239 if (match_int(&args[0], &option))
240 return -EINVAL;
241 uid = make_kuid(current_user_ns(), option);
242 if (!uid_valid(uid))
243 return -EINVAL;
244 hypfs_info->uid = uid;
245 break;
246 case opt_gid:
247 if (match_int(&args[0], &option))
248 return -EINVAL;
249 gid = make_kgid(current_user_ns(), option);
250 if (!gid_valid(gid))
251 return -EINVAL;
252 hypfs_info->gid = gid;
253 break;
254 case opt_err:
255 default:
256 pr_err("%s is not a valid mount option\n", str);
257 return -EINVAL;
258 }
259 }
260 return 0;
261}
262
263static int hypfs_show_options(struct seq_file *s, struct dentry *root)
264{
265 struct hypfs_sb_info *hypfs_info = root->d_sb->s_fs_info;
266
267 seq_printf(s, ",uid=%u", from_kuid_munged(&init_user_ns, hypfs_info->uid));
268 seq_printf(s, ",gid=%u", from_kgid_munged(&init_user_ns, hypfs_info->gid));
269 return 0;
270}
271
272static int hypfs_fill_super(struct super_block *sb, void *data, int silent)
273{
274 struct inode *root_inode;
275 struct dentry *root_dentry;
276 int rc = 0;
277 struct hypfs_sb_info *sbi;
278
279 sbi = kzalloc(sizeof(struct hypfs_sb_info), GFP_KERNEL);
280 if (!sbi)
281 return -ENOMEM;
282 mutex_init(&sbi->lock);
283 sbi->uid = current_uid();
284 sbi->gid = current_gid();
285 sb->s_fs_info = sbi;
286 sb->s_blocksize = PAGE_CACHE_SIZE;
287 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
288 sb->s_magic = HYPFS_MAGIC;
289 sb->s_op = &hypfs_s_ops;
290 if (hypfs_parse_options(data, sb))
291 return -EINVAL;
292 root_inode = hypfs_make_inode(sb, S_IFDIR | 0755);
293 if (!root_inode)
294 return -ENOMEM;
295 root_inode->i_op = &simple_dir_inode_operations;
296 root_inode->i_fop = &simple_dir_operations;
297 sb->s_root = root_dentry = d_make_root(root_inode);
298 if (!root_dentry)
299 return -ENOMEM;
300 if (MACHINE_IS_VM)
301 rc = hypfs_vm_create_files(root_dentry);
302 else
303 rc = hypfs_diag_create_files(root_dentry);
304 if (rc)
305 return rc;
306 sbi->update_file = hypfs_create_update_file(root_dentry);
307 if (IS_ERR(sbi->update_file))
308 return PTR_ERR(sbi->update_file);
309 hypfs_update_update(sb);
310 pr_info("Hypervisor filesystem mounted\n");
311 return 0;
312}
313
314static struct dentry *hypfs_mount(struct file_system_type *fst, int flags,
315 const char *devname, void *data)
316{
317 return mount_single(fst, flags, data, hypfs_fill_super);
318}
319
320static void hypfs_kill_super(struct super_block *sb)
321{
322 struct hypfs_sb_info *sb_info = sb->s_fs_info;
323
324 if (sb->s_root)
325 hypfs_delete_tree(sb->s_root);
326 if (sb_info->update_file)
327 hypfs_remove(sb_info->update_file);
328 kfree(sb->s_fs_info);
329 sb->s_fs_info = NULL;
330 kill_litter_super(sb);
331}
332
333static struct dentry *hypfs_create_file(struct dentry *parent, const char *name,
334 char *data, umode_t mode)
335{
336 struct dentry *dentry;
337 struct inode *inode;
338
339 mutex_lock(&d_inode(parent)->i_mutex);
340 dentry = lookup_one_len(name, parent, strlen(name));
341 if (IS_ERR(dentry)) {
342 dentry = ERR_PTR(-ENOMEM);
343 goto fail;
344 }
345 inode = hypfs_make_inode(parent->d_sb, mode);
346 if (!inode) {
347 dput(dentry);
348 dentry = ERR_PTR(-ENOMEM);
349 goto fail;
350 }
351 if (S_ISREG(mode)) {
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 (S_ISDIR(mode)) {
358 inode->i_op = &simple_dir_inode_operations;
359 inode->i_fop = &simple_dir_operations;
360 inc_nlink(d_inode(parent));
361 } else
362 BUG();
363 inode->i_private = data;
364 d_instantiate(dentry, inode);
365 dget(dentry);
366fail:
367 mutex_unlock(&d_inode(parent)->i_mutex);
368 return dentry;
369}
370
371struct dentry *hypfs_mkdir(struct dentry *parent, const char *name)
372{
373 struct dentry *dentry;
374
375 dentry = hypfs_create_file(parent, name, NULL, S_IFDIR | DIR_MODE);
376 if (IS_ERR(dentry))
377 return dentry;
378 hypfs_add_dentry(dentry);
379 return dentry;
380}
381
382static struct dentry *hypfs_create_update_file(struct dentry *dir)
383{
384 struct dentry *dentry;
385
386 dentry = hypfs_create_file(dir, "update", NULL,
387 S_IFREG | UPDATE_FILE_MODE);
388
389
390
391
392
393 return dentry;
394}
395
396struct dentry *hypfs_create_u64(struct dentry *dir,
397 const char *name, __u64 value)
398{
399 char *buffer;
400 char tmp[TMP_SIZE];
401 struct dentry *dentry;
402
403 snprintf(tmp, TMP_SIZE, "%llu\n", (unsigned long long int)value);
404 buffer = kstrdup(tmp, GFP_KERNEL);
405 if (!buffer)
406 return ERR_PTR(-ENOMEM);
407 dentry =
408 hypfs_create_file(dir, name, buffer, S_IFREG | REG_FILE_MODE);
409 if (IS_ERR(dentry)) {
410 kfree(buffer);
411 return ERR_PTR(-ENOMEM);
412 }
413 hypfs_add_dentry(dentry);
414 return dentry;
415}
416
417struct dentry *hypfs_create_str(struct dentry *dir,
418 const char *name, char *string)
419{
420 char *buffer;
421 struct dentry *dentry;
422
423 buffer = kmalloc(strlen(string) + 2, GFP_KERNEL);
424 if (!buffer)
425 return ERR_PTR(-ENOMEM);
426 sprintf(buffer, "%s\n", string);
427 dentry =
428 hypfs_create_file(dir, name, buffer, S_IFREG | REG_FILE_MODE);
429 if (IS_ERR(dentry)) {
430 kfree(buffer);
431 return ERR_PTR(-ENOMEM);
432 }
433 hypfs_add_dentry(dentry);
434 return dentry;
435}
436
437static const struct file_operations hypfs_file_ops = {
438 .open = hypfs_open,
439 .release = hypfs_release,
440 .read_iter = hypfs_read_iter,
441 .write_iter = hypfs_write_iter,
442 .llseek = no_llseek,
443};
444
445static struct file_system_type hypfs_type = {
446 .owner = THIS_MODULE,
447 .name = "s390_hypfs",
448 .mount = hypfs_mount,
449 .kill_sb = hypfs_kill_super
450};
451MODULE_ALIAS_FS("s390_hypfs");
452
453static const struct super_operations hypfs_s_ops = {
454 .statfs = simple_statfs,
455 .evict_inode = hypfs_evict_inode,
456 .show_options = hypfs_show_options,
457};
458
459static struct kobject *s390_kobj;
460
461static int __init hypfs_init(void)
462{
463 int rc;
464
465 rc = hypfs_dbfs_init();
466 if (rc)
467 return rc;
468 if (hypfs_diag_init()) {
469 rc = -ENODATA;
470 goto fail_dbfs_exit;
471 }
472 if (hypfs_vm_init()) {
473 rc = -ENODATA;
474 goto fail_hypfs_diag_exit;
475 }
476 if (hypfs_sprp_init()) {
477 rc = -ENODATA;
478 goto fail_hypfs_vm_exit;
479 }
480 if (hypfs_diag0c_init()) {
481 rc = -ENODATA;
482 goto fail_hypfs_sprp_exit;
483 }
484 s390_kobj = kobject_create_and_add("s390", hypervisor_kobj);
485 if (!s390_kobj) {
486 rc = -ENOMEM;
487 goto fail_hypfs_diag0c_exit;
488 }
489 rc = register_filesystem(&hypfs_type);
490 if (rc)
491 goto fail_filesystem;
492 return 0;
493
494fail_filesystem:
495 kobject_put(s390_kobj);
496fail_hypfs_diag0c_exit:
497 hypfs_diag0c_exit();
498fail_hypfs_sprp_exit:
499 hypfs_sprp_exit();
500fail_hypfs_vm_exit:
501 hypfs_vm_exit();
502fail_hypfs_diag_exit:
503 hypfs_diag_exit();
504fail_dbfs_exit:
505 hypfs_dbfs_exit();
506 pr_err("Initialization of hypfs failed with rc=%i\n", rc);
507 return rc;
508}
509
510static void __exit hypfs_exit(void)
511{
512 unregister_filesystem(&hypfs_type);
513 kobject_put(s390_kobj);
514 hypfs_diag0c_exit();
515 hypfs_sprp_exit();
516 hypfs_vm_exit();
517 hypfs_diag_exit();
518 hypfs_dbfs_exit();
519}
520
521module_init(hypfs_init)
522module_exit(hypfs_exit)
523
524MODULE_LICENSE("GPL");
525MODULE_AUTHOR("Michael Holzheu <holzheu@de.ibm.com>");
526MODULE_DESCRIPTION("s390 Hypervisor Filesystem");
527
