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9#define KMSG_COMPONENT "hypfs"
10#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
11
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/slab.h>
18#include <linux/pagemap.h>
19#include <linux/time.h>
20#include <linux/parser.h>
21#include <linux/sysfs.h>
22#include <linux/init.h>
23#include <linux/kobject.h>
24#include <linux/seq_file.h>
25#include <linux/mount.h>
26#include <linux/uio.h>
27#include <asm/ebcdic.h>
28#include "hypfs.h"
29
30#define HYPFS_MAGIC 0x687970
31#define TMP_SIZE 64
32
33static struct dentry *hypfs_create_update_file(struct dentry *dir);
34
35struct hypfs_sb_info {
36 kuid_t uid;
37 kgid_t gid;
38 struct dentry *update_file;
39 time64_t last_update;
40 struct mutex lock;
41};
42
43static const struct file_operations hypfs_file_ops;
44static struct file_system_type hypfs_type;
45static const struct super_operations hypfs_s_ops;
46
47
48static struct dentry *hypfs_last_dentry;
49
50static void hypfs_update_update(struct super_block *sb)
51{
52 struct hypfs_sb_info *sb_info = sb->s_fs_info;
53 struct inode *inode = d_inode(sb_info->update_file);
54
55 sb_info->last_update = ktime_get_seconds();
56 inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
57}
58
59
60
61static void hypfs_add_dentry(struct dentry *dentry)
62{
63 dentry->d_fsdata = hypfs_last_dentry;
64 hypfs_last_dentry = dentry;
65}
66
67static void hypfs_remove(struct dentry *dentry)
68{
69 struct dentry *parent;
70
71 parent = dentry->d_parent;
72 inode_lock(d_inode(parent));
73 if (simple_positive(dentry)) {
74 if (d_is_dir(dentry))
75 simple_rmdir(d_inode(parent), dentry);
76 else
77 simple_unlink(d_inode(parent), dentry);
78 }
79 d_delete(dentry);
80 dput(dentry);
81 inode_unlock(d_inode(parent));
82}
83
84static void hypfs_delete_tree(struct dentry *root)
85{
86 while (hypfs_last_dentry) {
87 struct dentry *next_dentry;
88 next_dentry = hypfs_last_dentry->d_fsdata;
89 hypfs_remove(hypfs_last_dentry);
90 hypfs_last_dentry = next_dentry;
91 }
92}
93
94static struct inode *hypfs_make_inode(struct super_block *sb, umode_t mode)
95{
96 struct inode *ret = new_inode(sb);
97
98 if (ret) {
99 struct hypfs_sb_info *hypfs_info = sb->s_fs_info;
100 ret->i_ino = get_next_ino();
101 ret->i_mode = mode;
102 ret->i_uid = hypfs_info->uid;
103 ret->i_gid = hypfs_info->gid;
104 ret->i_atime = ret->i_mtime = ret->i_ctime = current_time(ret);
105 if (S_ISDIR(mode))
106 set_nlink(ret, 2);
107 }
108 return ret;
109}
110
111static void hypfs_evict_inode(struct inode *inode)
112{
113 clear_inode(inode);
114 kfree(inode->i_private);
115}
116
117static int hypfs_open(struct inode *inode, struct file *filp)
118{
119 char *data = file_inode(filp)->i_private;
120 struct hypfs_sb_info *fs_info;
121
122 if (filp->f_mode & FMODE_WRITE) {
123 if (!(inode->i_mode & S_IWUGO))
124 return -EACCES;
125 }
126 if (filp->f_mode & FMODE_READ) {
127 if (!(inode->i_mode & S_IRUGO))
128 return -EACCES;
129 }
130
131 fs_info = inode->i_sb->s_fs_info;
132 if(data) {
133 mutex_lock(&fs_info->lock);
134 filp->private_data = kstrdup(data, GFP_KERNEL);
135 if (!filp->private_data) {
136 mutex_unlock(&fs_info->lock);
137 return -ENOMEM;
138 }
139 mutex_unlock(&fs_info->lock);
140 }
141 return nonseekable_open(inode, filp);
142}
143
144static ssize_t hypfs_read_iter(struct kiocb *iocb, struct iov_iter *to)
145{
146 struct file *file = iocb->ki_filp;
147 char *data = file->private_data;
148 size_t available = strlen(data);
149 loff_t pos = iocb->ki_pos;
150 size_t count;
151
152 if (pos < 0)
153 return -EINVAL;
154 if (pos >= available || !iov_iter_count(to))
155 return 0;
156 count = copy_to_iter(data + pos, available - pos, to);
157 if (!count)
158 return -EFAULT;
159 iocb->ki_pos = pos + count;
160 file_accessed(file);
161 return count;
162}
163
164static ssize_t hypfs_write_iter(struct kiocb *iocb, struct iov_iter *from)
165{
166 int rc;
167 struct super_block *sb = file_inode(iocb->ki_filp)->i_sb;
168 struct hypfs_sb_info *fs_info = sb->s_fs_info;
169 size_t count = iov_iter_count(from);
170
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178
179
180
181 mutex_lock(&fs_info->lock);
182 if (fs_info->last_update == ktime_get_seconds()) {
183 rc = -EBUSY;
184 goto out;
185 }
186 hypfs_delete_tree(sb->s_root);
187 if (MACHINE_IS_VM)
188 rc = hypfs_vm_create_files(sb->s_root);
189 else
190 rc = hypfs_diag_create_files(sb->s_root);
191 if (rc) {
192 pr_err("Updating the hypfs tree failed\n");
193 hypfs_delete_tree(sb->s_root);
194 goto out;
195 }
196 hypfs_update_update(sb);
197 rc = count;
198 iov_iter_advance(from, count);
199out:
200 mutex_unlock(&fs_info->lock);
201 return rc;
202}
203
204static int hypfs_release(struct inode *inode, struct file *filp)
205{
206 kfree(filp->private_data);
207 return 0;
208}
209
210enum { opt_uid, opt_gid, opt_err };
211
212static const match_table_t hypfs_tokens = {
213 {opt_uid, "uid=%u"},
214 {opt_gid, "gid=%u"},
215 {opt_err, NULL}
216};
217
218static int hypfs_parse_options(char *options, struct super_block *sb)
219{
220 char *str;
221 substring_t args[MAX_OPT_ARGS];
222 kuid_t uid;
223 kgid_t gid;
224
225 if (!options)
226 return 0;
227 while ((str = strsep(&options, ",")) != NULL) {
228 int token, option;
229 struct hypfs_sb_info *hypfs_info = sb->s_fs_info;
230
231 if (!*str)
232 continue;
233 token = match_token(str, hypfs_tokens, args);
234 switch (token) {
235 case opt_uid:
236 if (match_int(&args[0], &option))
237 return -EINVAL;
238 uid = make_kuid(current_user_ns(), option);
239 if (!uid_valid(uid))
240 return -EINVAL;
241 hypfs_info->uid = uid;
242 break;
243 case opt_gid:
244 if (match_int(&args[0], &option))
245 return -EINVAL;
246 gid = make_kgid(current_user_ns(), option);
247 if (!gid_valid(gid))
248 return -EINVAL;
249 hypfs_info->gid = gid;
250 break;
251 case opt_err:
252 default:
253 pr_err("%s is not a valid mount option\n", str);
254 return -EINVAL;
255 }
256 }
257 return 0;
258}
259
260static int hypfs_show_options(struct seq_file *s, struct dentry *root)
261{
262 struct hypfs_sb_info *hypfs_info = root->d_sb->s_fs_info;
263
264 seq_printf(s, ",uid=%u", from_kuid_munged(&init_user_ns, hypfs_info->uid));
265 seq_printf(s, ",gid=%u", from_kgid_munged(&init_user_ns, hypfs_info->gid));
266 return 0;
267}
268
269static int hypfs_fill_super(struct super_block *sb, void *data, int silent)
270{
271 struct inode *root_inode;
272 struct dentry *root_dentry;
273 int rc = 0;
274 struct hypfs_sb_info *sbi;
275
276 sbi = kzalloc(sizeof(struct hypfs_sb_info), GFP_KERNEL);
277 if (!sbi)
278 return -ENOMEM;
279 mutex_init(&sbi->lock);
280 sbi->uid = current_uid();
281 sbi->gid = current_gid();
282 sb->s_fs_info = sbi;
283 sb->s_blocksize = PAGE_SIZE;
284 sb->s_blocksize_bits = PAGE_SHIFT;
285 sb->s_magic = HYPFS_MAGIC;
286 sb->s_op = &hypfs_s_ops;
287 if (hypfs_parse_options(data, sb))
288 return -EINVAL;
289 root_inode = hypfs_make_inode(sb, S_IFDIR | 0755);
290 if (!root_inode)
291 return -ENOMEM;
292 root_inode->i_op = &simple_dir_inode_operations;
293 root_inode->i_fop = &simple_dir_operations;
294 sb->s_root = root_dentry = d_make_root(root_inode);
295 if (!root_dentry)
296 return -ENOMEM;
297 if (MACHINE_IS_VM)
298 rc = hypfs_vm_create_files(root_dentry);
299 else
300 rc = hypfs_diag_create_files(root_dentry);
301 if (rc)
302 return rc;
303 sbi->update_file = hypfs_create_update_file(root_dentry);
304 if (IS_ERR(sbi->update_file))
305 return PTR_ERR(sbi->update_file);
306 hypfs_update_update(sb);
307 pr_info("Hypervisor filesystem mounted\n");
308 return 0;
309}
310
311static struct dentry *hypfs_mount(struct file_system_type *fst, int flags,
312 const char *devname, void *data)
313{
314 return mount_single(fst, flags, data, hypfs_fill_super);
315}
316
317static void hypfs_kill_super(struct super_block *sb)
318{
319 struct hypfs_sb_info *sb_info = sb->s_fs_info;
320
321 if (sb->s_root)
322 hypfs_delete_tree(sb->s_root);
323 if (sb_info && sb_info->update_file)
324 hypfs_remove(sb_info->update_file);
325 kfree(sb->s_fs_info);
326 sb->s_fs_info = NULL;
327 kill_litter_super(sb);
328}
329
330static struct dentry *hypfs_create_file(struct dentry *parent, const char *name,
331 char *data, umode_t mode)
332{
333 struct dentry *dentry;
334 struct inode *inode;
335
336 inode_lock(d_inode(parent));
337 dentry = lookup_one_len(name, parent, strlen(name));
338 if (IS_ERR(dentry)) {
339 dentry = ERR_PTR(-ENOMEM);
340 goto fail;
341 }
342 inode = hypfs_make_inode(parent->d_sb, mode);
343 if (!inode) {
344 dput(dentry);
345 dentry = ERR_PTR(-ENOMEM);
346 goto fail;
347 }
348 if (S_ISREG(mode)) {
349 inode->i_fop = &hypfs_file_ops;
350 if (data)
351 inode->i_size = strlen(data);
352 else
353 inode->i_size = 0;
354 } else if (S_ISDIR(mode)) {
355 inode->i_op = &simple_dir_inode_operations;
356 inode->i_fop = &simple_dir_operations;
357 inc_nlink(d_inode(parent));
358 } else
359 BUG();
360 inode->i_private = data;
361 d_instantiate(dentry, inode);
362 dget(dentry);
363fail:
364 inode_unlock(d_inode(parent));
365 return dentry;
366}
367
368struct dentry *hypfs_mkdir(struct dentry *parent, const char *name)
369{
370 struct dentry *dentry;
371
372 dentry = hypfs_create_file(parent, name, NULL, S_IFDIR | DIR_MODE);
373 if (IS_ERR(dentry))
374 return dentry;
375 hypfs_add_dentry(dentry);
376 return dentry;
377}
378
379static struct dentry *hypfs_create_update_file(struct dentry *dir)
380{
381 struct dentry *dentry;
382
383 dentry = hypfs_create_file(dir, "update", NULL,
384 S_IFREG | UPDATE_FILE_MODE);
385
386
387
388
389
390 return dentry;
391}
392
393struct dentry *hypfs_create_u64(struct dentry *dir,
394 const char *name, __u64 value)
395{
396 char *buffer;
397 char tmp[TMP_SIZE];
398 struct dentry *dentry;
399
400 snprintf(tmp, TMP_SIZE, "%llu\n", (unsigned long long int)value);
401 buffer = kstrdup(tmp, GFP_KERNEL);
402 if (!buffer)
403 return ERR_PTR(-ENOMEM);
404 dentry =
405 hypfs_create_file(dir, name, buffer, S_IFREG | REG_FILE_MODE);
406 if (IS_ERR(dentry)) {
407 kfree(buffer);
408 return ERR_PTR(-ENOMEM);
409 }
410 hypfs_add_dentry(dentry);
411 return dentry;
412}
413
414struct dentry *hypfs_create_str(struct dentry *dir,
415 const char *name, char *string)
416{
417 char *buffer;
418 struct dentry *dentry;
419
420 buffer = kmalloc(strlen(string) + 2, GFP_KERNEL);
421 if (!buffer)
422 return ERR_PTR(-ENOMEM);
423 sprintf(buffer, "%s\n", string);
424 dentry =
425 hypfs_create_file(dir, name, buffer, S_IFREG | REG_FILE_MODE);
426 if (IS_ERR(dentry)) {
427 kfree(buffer);
428 return ERR_PTR(-ENOMEM);
429 }
430 hypfs_add_dentry(dentry);
431 return dentry;
432}
433
434static const struct file_operations hypfs_file_ops = {
435 .open = hypfs_open,
436 .release = hypfs_release,
437 .read_iter = hypfs_read_iter,
438 .write_iter = hypfs_write_iter,
439 .llseek = no_llseek,
440};
441
442static struct file_system_type hypfs_type = {
443 .owner = THIS_MODULE,
444 .name = "s390_hypfs",
445 .mount = hypfs_mount,
446 .kill_sb = hypfs_kill_super
447};
448
449static const struct super_operations hypfs_s_ops = {
450 .statfs = simple_statfs,
451 .evict_inode = hypfs_evict_inode,
452 .show_options = hypfs_show_options,
453};
454
455static int __init hypfs_init(void)
456{
457 int rc;
458
459 rc = hypfs_dbfs_init();
460 if (rc)
461 return rc;
462 if (hypfs_diag_init()) {
463 rc = -ENODATA;
464 goto fail_dbfs_exit;
465 }
466 if (hypfs_vm_init()) {
467 rc = -ENODATA;
468 goto fail_hypfs_diag_exit;
469 }
470 if (hypfs_sprp_init()) {
471 rc = -ENODATA;
472 goto fail_hypfs_vm_exit;
473 }
474 if (hypfs_diag0c_init()) {
475 rc = -ENODATA;
476 goto fail_hypfs_sprp_exit;
477 }
478 rc = sysfs_create_mount_point(hypervisor_kobj, "s390");
479 if (rc)
480 goto fail_hypfs_diag0c_exit;
481 rc = register_filesystem(&hypfs_type);
482 if (rc)
483 goto fail_filesystem;
484 return 0;
485
486fail_filesystem:
487 sysfs_remove_mount_point(hypervisor_kobj, "s390");
488fail_hypfs_diag0c_exit:
489 hypfs_diag0c_exit();
490fail_hypfs_sprp_exit:
491 hypfs_sprp_exit();
492fail_hypfs_vm_exit:
493 hypfs_vm_exit();
494fail_hypfs_diag_exit:
495 hypfs_diag_exit();
496fail_dbfs_exit:
497 hypfs_dbfs_exit();
498 pr_err("Initialization of hypfs failed with rc=%i\n", rc);
499 return rc;
500}
501device_initcall(hypfs_init)
502
