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