This source file includes following definitions.
- hypfs_update_update
- hypfs_add_dentry
- hypfs_remove
- hypfs_delete_tree
- hypfs_make_inode
- hypfs_evict_inode
- hypfs_open
- hypfs_read_iter
- hypfs_write_iter
- hypfs_release
- hypfs_parse_param
- hypfs_show_options
- hypfs_fill_super
- hypfs_get_tree
- hypfs_free_fc
- hypfs_init_fs_context
- hypfs_kill_super
- hypfs_create_file
- hypfs_mkdir
- hypfs_create_update_file
- hypfs_create_u64
- hypfs_create_str
- hypfs_init
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8
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/fs_context.h>
16 #include <linux/fs_parser.h>
17 #include <linux/namei.h>
18 #include <linux/vfs.h>
19 #include <linux/slab.h>
20 #include <linux/pagemap.h>
21 #include <linux/time.h>
22 #include <linux/sysfs.h>
23 #include <linux/init.h>
24 #include <linux/kobject.h>
25 #include <linux/seq_file.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
33 static struct dentry *hypfs_create_update_file(struct dentry *dir);
34
35 struct 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
43 static const struct file_operations hypfs_file_ops;
44 static struct file_system_type hypfs_type;
45 static const struct super_operations hypfs_s_ops;
46
47
48 static struct dentry *hypfs_last_dentry;
49
50 static 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
61 static void hypfs_add_dentry(struct dentry *dentry)
62 {
63 dentry->d_fsdata = hypfs_last_dentry;
64 hypfs_last_dentry = dentry;
65 }
66
67 static 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_drop(dentry);
80 dput(dentry);
81 inode_unlock(d_inode(parent));
82 }
83
84 static 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
94 static 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
111 static void hypfs_evict_inode(struct inode *inode)
112 {
113 clear_inode(inode);
114 kfree(inode->i_private);
115 }
116
117 static 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
144 static 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
164 static 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
171
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173
174
175
176
177
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);
199 out:
200 mutex_unlock(&fs_info->lock);
201 return rc;
202 }
203
204 static int hypfs_release(struct inode *inode, struct file *filp)
205 {
206 kfree(filp->private_data);
207 return 0;
208 }
209
210 enum { Opt_uid, Opt_gid, };
211
212 static const struct fs_parameter_spec hypfs_param_specs[] = {
213 fsparam_u32("gid", Opt_gid),
214 fsparam_u32("uid", Opt_uid),
215 {}
216 };
217
218 static const struct fs_parameter_description hypfs_fs_parameters = {
219 .name = "hypfs",
220 .specs = hypfs_param_specs,
221 };
222
223 static int hypfs_parse_param(struct fs_context *fc, struct fs_parameter *param)
224 {
225 struct hypfs_sb_info *hypfs_info = fc->s_fs_info;
226 struct fs_parse_result result;
227 kuid_t uid;
228 kgid_t gid;
229 int opt;
230
231 opt = fs_parse(fc, &hypfs_fs_parameters, param, &result);
232 if (opt < 0)
233 return opt;
234
235 switch (opt) {
236 case Opt_uid:
237 uid = make_kuid(current_user_ns(), result.uint_32);
238 if (!uid_valid(uid))
239 return invalf(fc, "Unknown uid");
240 hypfs_info->uid = uid;
241 break;
242 case Opt_gid:
243 gid = make_kgid(current_user_ns(), result.uint_32);
244 if (!gid_valid(gid))
245 return invalf(fc, "Unknown gid");
246 hypfs_info->gid = gid;
247 break;
248 }
249 return 0;
250 }
251
252 static int hypfs_show_options(struct seq_file *s, struct dentry *root)
253 {
254 struct hypfs_sb_info *hypfs_info = root->d_sb->s_fs_info;
255
256 seq_printf(s, ",uid=%u", from_kuid_munged(&init_user_ns, hypfs_info->uid));
257 seq_printf(s, ",gid=%u", from_kgid_munged(&init_user_ns, hypfs_info->gid));
258 return 0;
259 }
260
261 static int hypfs_fill_super(struct super_block *sb, struct fs_context *fc)
262 {
263 struct hypfs_sb_info *sbi = sb->s_fs_info;
264 struct inode *root_inode;
265 struct dentry *root_dentry, *update_file;
266 int rc;
267
268 sb->s_blocksize = PAGE_SIZE;
269 sb->s_blocksize_bits = PAGE_SHIFT;
270 sb->s_magic = HYPFS_MAGIC;
271 sb->s_op = &hypfs_s_ops;
272
273 root_inode = hypfs_make_inode(sb, S_IFDIR | 0755);
274 if (!root_inode)
275 return -ENOMEM;
276 root_inode->i_op = &simple_dir_inode_operations;
277 root_inode->i_fop = &simple_dir_operations;
278 sb->s_root = root_dentry = d_make_root(root_inode);
279 if (!root_dentry)
280 return -ENOMEM;
281 if (MACHINE_IS_VM)
282 rc = hypfs_vm_create_files(root_dentry);
283 else
284 rc = hypfs_diag_create_files(root_dentry);
285 if (rc)
286 return rc;
287 update_file = hypfs_create_update_file(root_dentry);
288 if (IS_ERR(update_file))
289 return PTR_ERR(update_file);
290 sbi->update_file = update_file;
291 hypfs_update_update(sb);
292 pr_info("Hypervisor filesystem mounted\n");
293 return 0;
294 }
295
296 static int hypfs_get_tree(struct fs_context *fc)
297 {
298 return get_tree_single(fc, hypfs_fill_super);
299 }
300
301 static void hypfs_free_fc(struct fs_context *fc)
302 {
303 kfree(fc->s_fs_info);
304 }
305
306 static const struct fs_context_operations hypfs_context_ops = {
307 .free = hypfs_free_fc,
308 .parse_param = hypfs_parse_param,
309 .get_tree = hypfs_get_tree,
310 };
311
312 static int hypfs_init_fs_context(struct fs_context *fc)
313 {
314 struct hypfs_sb_info *sbi;
315
316 sbi = kzalloc(sizeof(struct hypfs_sb_info), GFP_KERNEL);
317 if (!sbi)
318 return -ENOMEM;
319
320 mutex_init(&sbi->lock);
321 sbi->uid = current_uid();
322 sbi->gid = current_gid();
323
324 fc->s_fs_info = sbi;
325 fc->ops = &hypfs_context_ops;
326 return 0;
327 }
328
329 static void hypfs_kill_super(struct super_block *sb)
330 {
331 struct hypfs_sb_info *sb_info = sb->s_fs_info;
332
333 if (sb->s_root)
334 hypfs_delete_tree(sb->s_root);
335 if (sb_info && sb_info->update_file)
336 hypfs_remove(sb_info->update_file);
337 kfree(sb->s_fs_info);
338 sb->s_fs_info = NULL;
339 kill_litter_super(sb);
340 }
341
342 static struct dentry *hypfs_create_file(struct dentry *parent, const char *name,
343 char *data, umode_t mode)
344 {
345 struct dentry *dentry;
346 struct inode *inode;
347
348 inode_lock(d_inode(parent));
349 dentry = lookup_one_len(name, parent, strlen(name));
350 if (IS_ERR(dentry)) {
351 dentry = ERR_PTR(-ENOMEM);
352 goto fail;
353 }
354 inode = hypfs_make_inode(parent->d_sb, mode);
355 if (!inode) {
356 dput(dentry);
357 dentry = ERR_PTR(-ENOMEM);
358 goto fail;
359 }
360 if (S_ISREG(mode)) {
361 inode->i_fop = &hypfs_file_ops;
362 if (data)
363 inode->i_size = strlen(data);
364 else
365 inode->i_size = 0;
366 } else if (S_ISDIR(mode)) {
367 inode->i_op = &simple_dir_inode_operations;
368 inode->i_fop = &simple_dir_operations;
369 inc_nlink(d_inode(parent));
370 } else
371 BUG();
372 inode->i_private = data;
373 d_instantiate(dentry, inode);
374 dget(dentry);
375 fail:
376 inode_unlock(d_inode(parent));
377 return dentry;
378 }
379
380 struct dentry *hypfs_mkdir(struct dentry *parent, const char *name)
381 {
382 struct dentry *dentry;
383
384 dentry = hypfs_create_file(parent, name, NULL, S_IFDIR | DIR_MODE);
385 if (IS_ERR(dentry))
386 return dentry;
387 hypfs_add_dentry(dentry);
388 return dentry;
389 }
390
391 static struct dentry *hypfs_create_update_file(struct dentry *dir)
392 {
393 struct dentry *dentry;
394
395 dentry = hypfs_create_file(dir, "update", NULL,
396 S_IFREG | UPDATE_FILE_MODE);
397
398
399
400
401
402 return dentry;
403 }
404
405 struct dentry *hypfs_create_u64(struct dentry *dir,
406 const char *name, __u64 value)
407 {
408 char *buffer;
409 char tmp[TMP_SIZE];
410 struct dentry *dentry;
411
412 snprintf(tmp, TMP_SIZE, "%llu\n", (unsigned long long int)value);
413 buffer = kstrdup(tmp, GFP_KERNEL);
414 if (!buffer)
415 return ERR_PTR(-ENOMEM);
416 dentry =
417 hypfs_create_file(dir, name, buffer, S_IFREG | REG_FILE_MODE);
418 if (IS_ERR(dentry)) {
419 kfree(buffer);
420 return ERR_PTR(-ENOMEM);
421 }
422 hypfs_add_dentry(dentry);
423 return dentry;
424 }
425
426 struct dentry *hypfs_create_str(struct dentry *dir,
427 const char *name, char *string)
428 {
429 char *buffer;
430 struct dentry *dentry;
431
432 buffer = kmalloc(strlen(string) + 2, GFP_KERNEL);
433 if (!buffer)
434 return ERR_PTR(-ENOMEM);
435 sprintf(buffer, "%s\n", string);
436 dentry =
437 hypfs_create_file(dir, name, buffer, S_IFREG | REG_FILE_MODE);
438 if (IS_ERR(dentry)) {
439 kfree(buffer);
440 return ERR_PTR(-ENOMEM);
441 }
442 hypfs_add_dentry(dentry);
443 return dentry;
444 }
445
446 static const struct file_operations hypfs_file_ops = {
447 .open = hypfs_open,
448 .release = hypfs_release,
449 .read_iter = hypfs_read_iter,
450 .write_iter = hypfs_write_iter,
451 .llseek = no_llseek,
452 };
453
454 static struct file_system_type hypfs_type = {
455 .owner = THIS_MODULE,
456 .name = "s390_hypfs",
457 .init_fs_context = hypfs_init_fs_context,
458 .parameters = &hypfs_fs_parameters,
459 .kill_sb = hypfs_kill_super
460 };
461
462 static const struct super_operations hypfs_s_ops = {
463 .statfs = simple_statfs,
464 .evict_inode = hypfs_evict_inode,
465 .show_options = hypfs_show_options,
466 };
467
468 static int __init hypfs_init(void)
469 {
470 int rc;
471
472 hypfs_dbfs_init();
473
474 if (hypfs_diag_init()) {
475 rc = -ENODATA;
476 goto fail_dbfs_exit;
477 }
478 if (hypfs_vm_init()) {
479 rc = -ENODATA;
480 goto fail_hypfs_diag_exit;
481 }
482 hypfs_sprp_init();
483 if (hypfs_diag0c_init()) {
484 rc = -ENODATA;
485 goto fail_hypfs_sprp_exit;
486 }
487 rc = sysfs_create_mount_point(hypervisor_kobj, "s390");
488 if (rc)
489 goto fail_hypfs_diag0c_exit;
490 rc = register_filesystem(&hypfs_type);
491 if (rc)
492 goto fail_filesystem;
493 return 0;
494
495 fail_filesystem:
496 sysfs_remove_mount_point(hypervisor_kobj, "s390");
497 fail_hypfs_diag0c_exit:
498 hypfs_diag0c_exit();
499 fail_hypfs_sprp_exit:
500 hypfs_sprp_exit();
501 hypfs_vm_exit();
502 fail_hypfs_diag_exit:
503 hypfs_diag_exit();
504 fail_dbfs_exit:
505 hypfs_dbfs_exit();
506 pr_err("Initialization of hypfs failed with rc=%i\n", rc);
507 return rc;
508 }
509 device_initcall(hypfs_init)