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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/aio.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 super_block *sb,
32 struct dentry *dir);
33
34struct hypfs_sb_info {
35 kuid_t uid;
36 kgid_t gid;
37 struct dentry *update_file;
38 time_t last_update;
39 struct mutex lock;
40};
41
42static const struct file_operations hypfs_file_ops;
43static struct file_system_type hypfs_type;
44static const struct super_operations hypfs_s_ops;
45
46
47static struct dentry *hypfs_last_dentry;
48
49static void hypfs_update_update(struct super_block *sb)
50{
51 struct hypfs_sb_info *sb_info = sb->s_fs_info;
52 struct inode *inode = sb_info->update_file->d_inode;
53
54 sb_info->last_update = get_seconds();
55 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
56}
57
58
59
60static void hypfs_add_dentry(struct dentry *dentry)
61{
62 dentry->d_fsdata = hypfs_last_dentry;
63 hypfs_last_dentry = dentry;
64}
65
66static inline int hypfs_positive(struct dentry *dentry)
67{
68 return dentry->d_inode && !d_unhashed(dentry);
69}
70
71static void hypfs_remove(struct dentry *dentry)
72{
73 struct dentry *parent;
74
75 parent = dentry->d_parent;
76 mutex_lock(&parent->d_inode->i_mutex);
77 if (hypfs_positive(dentry)) {
78 if (S_ISDIR(dentry->d_inode->i_mode))
79 simple_rmdir(parent->d_inode, dentry);
80 else
81 simple_unlink(parent->d_inode, dentry);
82 }
83 d_delete(dentry);
84 dput(dentry);
85 mutex_unlock(&parent->d_inode->i_mutex);
86}
87
88static void hypfs_delete_tree(struct dentry *root)
89{
90 while (hypfs_last_dentry) {
91 struct dentry *next_dentry;
92 next_dentry = hypfs_last_dentry->d_fsdata;
93 hypfs_remove(hypfs_last_dentry);
94 hypfs_last_dentry = next_dentry;
95 }
96}
97
98static struct inode *hypfs_make_inode(struct super_block *sb, umode_t mode)
99{
100 struct inode *ret = new_inode(sb);
101
102 if (ret) {
103 struct hypfs_sb_info *hypfs_info = sb->s_fs_info;
104 ret->i_ino = get_next_ino();
105 ret->i_mode = mode;
106 ret->i_uid = hypfs_info->uid;
107 ret->i_gid = hypfs_info->gid;
108 ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME;
109 if (S_ISDIR(mode))
110 set_nlink(ret, 2);
111 }
112 return ret;
113}
114
115static void hypfs_evict_inode(struct inode *inode)
116{
117 clear_inode(inode);
118 kfree(inode->i_private);
119}
120
121static int hypfs_open(struct inode *inode, struct file *filp)
122{
123 char *data = file_inode(filp)->i_private;
124 struct hypfs_sb_info *fs_info;
125
126 if (filp->f_mode & FMODE_WRITE) {
127 if (!(inode->i_mode & S_IWUGO))
128 return -EACCES;
129 }
130 if (filp->f_mode & FMODE_READ) {
131 if (!(inode->i_mode & S_IRUGO))
132 return -EACCES;
133 }
134
135 fs_info = inode->i_sb->s_fs_info;
136 if(data) {
137 mutex_lock(&fs_info->lock);
138 filp->private_data = kstrdup(data, GFP_KERNEL);
139 if (!filp->private_data) {
140 mutex_unlock(&fs_info->lock);
141 return -ENOMEM;
142 }
143 mutex_unlock(&fs_info->lock);
144 }
145 return nonseekable_open(inode, filp);
146}
147
148static ssize_t hypfs_aio_read(struct kiocb *iocb, const struct iovec *iov,
149 unsigned long nr_segs, loff_t offset)
150{
151 char *data;
152 ssize_t ret;
153 struct file *filp = iocb->ki_filp;
154
155 char __user *buf = iov[0].iov_base;
156 size_t count = iov[0].iov_len;
157
158 if (nr_segs != 1)
159 return -EINVAL;
160
161 data = filp->private_data;
162 ret = simple_read_from_buffer(buf, count, &offset, data, strlen(data));
163 if (ret <= 0)
164 return ret;
165
166 iocb->ki_pos += ret;
167 file_accessed(filp);
168
169 return ret;
170}
171static ssize_t hypfs_aio_write(struct kiocb *iocb, const struct iovec *iov,
172 unsigned long nr_segs, loff_t offset)
173{
174 int rc;
175 struct super_block *sb = file_inode(iocb->ki_filp)->i_sb;
176 struct hypfs_sb_info *fs_info = sb->s_fs_info;
177 size_t count = iov_length(iov, nr_segs);
178
179
180
181
182
183
184
185
186
187
188
189 mutex_lock(&fs_info->lock);
190 if (fs_info->last_update == get_seconds()) {
191 rc = -EBUSY;
192 goto out;
193 }
194 hypfs_delete_tree(sb->s_root);
195 if (MACHINE_IS_VM)
196 rc = hypfs_vm_create_files(sb, sb->s_root);
197 else
198 rc = hypfs_diag_create_files(sb, sb->s_root);
199 if (rc) {
200 pr_err("Updating the hypfs tree failed\n");
201 hypfs_delete_tree(sb->s_root);
202 goto out;
203 }
204 hypfs_update_update(sb);
205 rc = count;
206out:
207 mutex_unlock(&fs_info->lock);
208 return rc;
209}
210
211static int hypfs_release(struct inode *inode, struct file *filp)
212{
213 kfree(filp->private_data);
214 return 0;
215}
216
217enum { opt_uid, opt_gid, opt_err };
218
219static const match_table_t hypfs_tokens = {
220 {opt_uid, "uid=%u"},
221 {opt_gid, "gid=%u"},
222 {opt_err, NULL}
223};
224
225static int hypfs_parse_options(char *options, struct super_block *sb)
226{
227 char *str;
228 substring_t args[MAX_OPT_ARGS];
229 kuid_t uid;
230 kgid_t gid;
231
232 if (!options)
233 return 0;
234 while ((str = strsep(&options, ",")) != NULL) {
235 int token, option;
236 struct hypfs_sb_info *hypfs_info = sb->s_fs_info;
237
238 if (!*str)
239 continue;
240 token = match_token(str, hypfs_tokens, args);
241 switch (token) {
242 case opt_uid:
243 if (match_int(&args[0], &option))
244 return -EINVAL;
245 uid = make_kuid(current_user_ns(), option);
246 if (!uid_valid(uid))
247 return -EINVAL;
248 hypfs_info->uid = uid;
249 break;
250 case opt_gid:
251 if (match_int(&args[0], &option))
252 return -EINVAL;
253 gid = make_kgid(current_user_ns(), option);
254 if (!gid_valid(gid))
255 return -EINVAL;
256 hypfs_info->gid = gid;
257 break;
258 case opt_err:
259 default:
260 pr_err("%s is not a valid mount option\n", str);
261 return -EINVAL;
262 }
263 }
264 return 0;
265}
266
267static int hypfs_show_options(struct seq_file *s, struct dentry *root)
268{
269 struct hypfs_sb_info *hypfs_info = root->d_sb->s_fs_info;
270
271 seq_printf(s, ",uid=%u", from_kuid_munged(&init_user_ns, hypfs_info->uid));
272 seq_printf(s, ",gid=%u", from_kgid_munged(&init_user_ns, hypfs_info->gid));
273 return 0;
274}
275
276static int hypfs_fill_super(struct super_block *sb, void *data, int silent)
277{
278 struct inode *root_inode;
279 struct dentry *root_dentry;
280 int rc = 0;
281 struct hypfs_sb_info *sbi;
282
283 sbi = kzalloc(sizeof(struct hypfs_sb_info), GFP_KERNEL);
284 if (!sbi)
285 return -ENOMEM;
286 mutex_init(&sbi->lock);
287 sbi->uid = current_uid();
288 sbi->gid = current_gid();
289 sb->s_fs_info = sbi;
290 sb->s_blocksize = PAGE_CACHE_SIZE;
291 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
292 sb->s_magic = HYPFS_MAGIC;
293 sb->s_op = &hypfs_s_ops;
294 if (hypfs_parse_options(data, sb))
295 return -EINVAL;
296 root_inode = hypfs_make_inode(sb, S_IFDIR | 0755);
297 if (!root_inode)
298 return -ENOMEM;
299 root_inode->i_op = &simple_dir_inode_operations;
300 root_inode->i_fop = &simple_dir_operations;
301 sb->s_root = root_dentry = d_make_root(root_inode);
302 if (!root_dentry)
303 return -ENOMEM;
304 if (MACHINE_IS_VM)
305 rc = hypfs_vm_create_files(sb, root_dentry);
306 else
307 rc = hypfs_diag_create_files(sb, root_dentry);
308 if (rc)
309 return rc;
310 sbi->update_file = hypfs_create_update_file(sb, root_dentry);
311 if (IS_ERR(sbi->update_file))
312 return PTR_ERR(sbi->update_file);
313 hypfs_update_update(sb);
314 pr_info("Hypervisor filesystem mounted\n");
315 return 0;
316}
317
318static struct dentry *hypfs_mount(struct file_system_type *fst, int flags,
319 const char *devname, void *data)
320{
321 return mount_single(fst, flags, data, hypfs_fill_super);
322}
323
324static void hypfs_kill_super(struct super_block *sb)
325{
326 struct hypfs_sb_info *sb_info = sb->s_fs_info;
327
328 if (sb->s_root)
329 hypfs_delete_tree(sb->s_root);
330 if (sb_info->update_file)
331 hypfs_remove(sb_info->update_file);
332 kfree(sb->s_fs_info);
333 sb->s_fs_info = NULL;
334 kill_litter_super(sb);
335}
336
337static struct dentry *hypfs_create_file(struct super_block *sb,
338 struct dentry *parent, const char *name,
339 char *data, umode_t mode)
340{
341 struct dentry *dentry;
342 struct inode *inode;
343
344 mutex_lock(&parent->d_inode->i_mutex);
345 dentry = lookup_one_len(name, parent, strlen(name));
346 if (IS_ERR(dentry)) {
347 dentry = ERR_PTR(-ENOMEM);
348 goto fail;
349 }
350 inode = hypfs_make_inode(sb, mode);
351 if (!inode) {
352 dput(dentry);
353 dentry = ERR_PTR(-ENOMEM);
354 goto fail;
355 }
356 if (S_ISREG(mode)) {
357 inode->i_fop = &hypfs_file_ops;
358 if (data)
359 inode->i_size = strlen(data);
360 else
361 inode->i_size = 0;
362 } else if (S_ISDIR(mode)) {
363 inode->i_op = &simple_dir_inode_operations;
364 inode->i_fop = &simple_dir_operations;
365 inc_nlink(parent->d_inode);
366 } else
367 BUG();
368 inode->i_private = data;
369 d_instantiate(dentry, inode);
370 dget(dentry);
371fail:
372 mutex_unlock(&parent->d_inode->i_mutex);
373 return dentry;
374}
375
376struct dentry *hypfs_mkdir(struct super_block *sb, struct dentry *parent,
377 const char *name)
378{
379 struct dentry *dentry;
380
381 dentry = hypfs_create_file(sb, parent, name, NULL, S_IFDIR | DIR_MODE);
382 if (IS_ERR(dentry))
383 return dentry;
384 hypfs_add_dentry(dentry);
385 return dentry;
386}
387
388static struct dentry *hypfs_create_update_file(struct super_block *sb,
389 struct dentry *dir)
390{
391 struct dentry *dentry;
392
393 dentry = hypfs_create_file(sb, dir, "update", NULL,
394 S_IFREG | UPDATE_FILE_MODE);
395
396
397
398
399
400 return dentry;
401}
402
403struct dentry *hypfs_create_u64(struct super_block *sb, struct dentry *dir,
404 const char *name, __u64 value)
405{
406 char *buffer;
407 char tmp[TMP_SIZE];
408 struct dentry *dentry;
409
410 snprintf(tmp, TMP_SIZE, "%llu\n", (unsigned long long int)value);
411 buffer = kstrdup(tmp, GFP_KERNEL);
412 if (!buffer)
413 return ERR_PTR(-ENOMEM);
414 dentry =
415 hypfs_create_file(sb, dir, name, buffer, S_IFREG | REG_FILE_MODE);
416 if (IS_ERR(dentry)) {
417 kfree(buffer);
418 return ERR_PTR(-ENOMEM);
419 }
420 hypfs_add_dentry(dentry);
421 return dentry;
422}
423
424struct dentry *hypfs_create_str(struct super_block *sb, struct dentry *dir,
425 const char *name, char *string)
426{
427 char *buffer;
428 struct dentry *dentry;
429
430 buffer = kmalloc(strlen(string) + 2, GFP_KERNEL);
431 if (!buffer)
432 return ERR_PTR(-ENOMEM);
433 sprintf(buffer, "%s\n", string);
434 dentry =
435 hypfs_create_file(sb, dir, name, buffer, S_IFREG | REG_FILE_MODE);
436 if (IS_ERR(dentry)) {
437 kfree(buffer);
438 return ERR_PTR(-ENOMEM);
439 }
440 hypfs_add_dentry(dentry);
441 return dentry;
442}
443
444static const struct file_operations hypfs_file_ops = {
445 .open = hypfs_open,
446 .release = hypfs_release,
447 .read = do_sync_read,
448 .write = do_sync_write,
449 .aio_read = hypfs_aio_read,
450 .aio_write = hypfs_aio_write,
451 .llseek = no_llseek,
452};
453
454static struct file_system_type hypfs_type = {
455 .owner = THIS_MODULE,
456 .name = "s390_hypfs",
457 .mount = hypfs_mount,
458 .kill_sb = hypfs_kill_super
459};
460MODULE_ALIAS_FS("s390_hypfs");
461
462static 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
468static struct kobject *s390_kobj;
469
470static int __init hypfs_init(void)
471{
472 int rc;
473
474 rc = hypfs_dbfs_init();
475 if (rc)
476 return rc;
477 if (hypfs_diag_init()) {
478 rc = -ENODATA;
479 goto fail_dbfs_exit;
480 }
481 if (hypfs_vm_init()) {
482 rc = -ENODATA;
483 goto fail_hypfs_diag_exit;
484 }
485 s390_kobj = kobject_create_and_add("s390", hypervisor_kobj);
486 if (!s390_kobj) {
487 rc = -ENOMEM;
488 goto fail_hypfs_vm_exit;
489 }
490 rc = register_filesystem(&hypfs_type);
491 if (rc)
492 goto fail_filesystem;
493 return 0;
494
495fail_filesystem:
496 kobject_put(s390_kobj);
497fail_hypfs_vm_exit:
498 hypfs_vm_exit();
499fail_hypfs_diag_exit:
500 hypfs_diag_exit();
501fail_dbfs_exit:
502 hypfs_dbfs_exit();
503 pr_err("Initialization of hypfs failed with rc=%i\n", rc);
504 return rc;
505}
506
507static void __exit hypfs_exit(void)
508{
509 hypfs_diag_exit();
510 hypfs_vm_exit();
511 hypfs_dbfs_exit();
512 unregister_filesystem(&hypfs_type);
513 kobject_put(s390_kobj);
514}
515
516module_init(hypfs_init)
517module_exit(hypfs_exit)
518
519MODULE_LICENSE("GPL");
520MODULE_AUTHOR("Michael Holzheu <holzheu@de.ibm.com>");
521MODULE_DESCRIPTION("s390 Hypervisor Filesystem");
522
