1
2
3
4
5
6
7
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/namei.h>
16#include <linux/vfs.h>
17#include <linux/pagemap.h>
18#include <linux/gfp.h>
19#include <linux/time.h>
20#include <linux/parser.h>
21#include <linux/sysfs.h>
22#include <linux/module.h>
23#include <linux/seq_file.h>
24#include <linux/mount.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 uid_t uid;
36 gid_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 if (!parent || !parent->d_inode)
77 return;
78 mutex_lock(&parent->d_inode->i_mutex);
79 if (hypfs_positive(dentry)) {
80 if (S_ISDIR(dentry->d_inode->i_mode))
81 simple_rmdir(parent->d_inode, dentry);
82 else
83 simple_unlink(parent->d_inode, dentry);
84 }
85 d_delete(dentry);
86 dput(dentry);
87 mutex_unlock(&parent->d_inode->i_mutex);
88}
89
90static void hypfs_delete_tree(struct dentry *root)
91{
92 while (hypfs_last_dentry) {
93 struct dentry *next_dentry;
94 next_dentry = hypfs_last_dentry->d_fsdata;
95 hypfs_remove(hypfs_last_dentry);
96 hypfs_last_dentry = next_dentry;
97 }
98}
99
100static struct inode *hypfs_make_inode(struct super_block *sb, int mode)
101{
102 struct inode *ret = new_inode(sb);
103
104 if (ret) {
105 struct hypfs_sb_info *hypfs_info = sb->s_fs_info;
106 ret->i_mode = mode;
107 ret->i_uid = hypfs_info->uid;
108 ret->i_gid = hypfs_info->gid;
109 ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME;
110 if (mode & S_IFDIR)
111 ret->i_nlink = 2;
112 else
113 ret->i_nlink = 1;
114 }
115 return ret;
116}
117
118static void hypfs_drop_inode(struct inode *inode)
119{
120 kfree(inode->i_private);
121 generic_delete_inode(inode);
122}
123
124static int hypfs_open(struct inode *inode, struct file *filp)
125{
126 char *data = filp->f_path.dentry->d_inode->i_private;
127 struct hypfs_sb_info *fs_info;
128
129 if (filp->f_mode & FMODE_WRITE) {
130 if (!(inode->i_mode & S_IWUGO))
131 return -EACCES;
132 }
133 if (filp->f_mode & FMODE_READ) {
134 if (!(inode->i_mode & S_IRUGO))
135 return -EACCES;
136 }
137
138 fs_info = inode->i_sb->s_fs_info;
139 if(data) {
140 mutex_lock(&fs_info->lock);
141 filp->private_data = kstrdup(data, GFP_KERNEL);
142 if (!filp->private_data) {
143 mutex_unlock(&fs_info->lock);
144 return -ENOMEM;
145 }
146 mutex_unlock(&fs_info->lock);
147 }
148 return 0;
149}
150
151static ssize_t hypfs_aio_read(struct kiocb *iocb, const struct iovec *iov,
152 unsigned long nr_segs, loff_t offset)
153{
154 char *data;
155 ssize_t ret;
156 struct file *filp = iocb->ki_filp;
157
158 char __user *buf = iov[0].iov_base;
159 size_t count = iov[0].iov_len;
160
161 if (nr_segs != 1)
162 return -EINVAL;
163
164 data = filp->private_data;
165 ret = simple_read_from_buffer(buf, count, &offset, data, strlen(data));
166 if (ret <= 0)
167 return ret;
168
169 iocb->ki_pos += ret;
170 file_accessed(filp);
171
172 return ret;
173}
174static ssize_t hypfs_aio_write(struct kiocb *iocb, const struct iovec *iov,
175 unsigned long nr_segs, loff_t offset)
176{
177 int rc;
178 struct super_block *sb;
179 struct hypfs_sb_info *fs_info;
180 size_t count = iov_length(iov, nr_segs);
181
182 sb = iocb->ki_filp->f_path.dentry->d_inode->i_sb;
183 fs_info = sb->s_fs_info;
184
185
186
187
188
189
190
191
192
193
194 mutex_lock(&fs_info->lock);
195 if (fs_info->last_update == get_seconds()) {
196 rc = -EBUSY;
197 goto out;
198 }
199 hypfs_delete_tree(sb->s_root);
200 if (MACHINE_IS_VM)
201 rc = hypfs_vm_create_files(sb, sb->s_root);
202 else
203 rc = hypfs_diag_create_files(sb, sb->s_root);
204 if (rc) {
205 pr_err("Updating the hypfs tree failed\n");
206 hypfs_delete_tree(sb->s_root);
207 goto out;
208 }
209 hypfs_update_update(sb);
210 rc = count;
211out:
212 mutex_unlock(&fs_info->lock);
213 return rc;
214}
215
216static int hypfs_release(struct inode *inode, struct file *filp)
217{
218 kfree(filp->private_data);
219 return 0;
220}
221
222enum { opt_uid, opt_gid, opt_err };
223
224static const match_table_t hypfs_tokens = {
225 {opt_uid, "uid=%u"},
226 {opt_gid, "gid=%u"},
227 {opt_err, NULL}
228};
229
230static int hypfs_parse_options(char *options, struct super_block *sb)
231{
232 char *str;
233 substring_t args[MAX_OPT_ARGS];
234
235 if (!options)
236 return 0;
237 while ((str = strsep(&options, ",")) != NULL) {
238 int token, option;
239 struct hypfs_sb_info *hypfs_info = sb->s_fs_info;
240
241 if (!*str)
242 continue;
243 token = match_token(str, hypfs_tokens, args);
244 switch (token) {
245 case opt_uid:
246 if (match_int(&args[0], &option))
247 return -EINVAL;
248 hypfs_info->uid = option;
249 break;
250 case opt_gid:
251 if (match_int(&args[0], &option))
252 return -EINVAL;
253 hypfs_info->gid = option;
254 break;
255 case opt_err:
256 default:
257 pr_err("%s is not a valid mount option\n", str);
258 return -EINVAL;
259 }
260 }
261 return 0;
262}
263
264static int hypfs_show_options(struct seq_file *s, struct vfsmount *mnt)
265{
266 struct hypfs_sb_info *hypfs_info = mnt->mnt_sb->s_fs_info;
267
268 seq_printf(s, ",uid=%u", hypfs_info->uid);
269 seq_printf(s, ",gid=%u", hypfs_info->gid);
270 return 0;
271}
272
273static int hypfs_fill_super(struct super_block *sb, void *data, int silent)
274{
275 struct inode *root_inode;
276 struct dentry *root_dentry;
277 int rc = 0;
278 struct hypfs_sb_info *sbi;
279
280 sbi = kzalloc(sizeof(struct hypfs_sb_info), GFP_KERNEL);
281 if (!sbi)
282 return -ENOMEM;
283 mutex_init(&sbi->lock);
284 sbi->uid = current_uid();
285 sbi->gid = current_gid();
286 sb->s_fs_info = sbi;
287 sb->s_blocksize = PAGE_CACHE_SIZE;
288 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
289 sb->s_magic = HYPFS_MAGIC;
290 sb->s_op = &hypfs_s_ops;
291 if (hypfs_parse_options(data, sb)) {
292 rc = -EINVAL;
293 goto err_alloc;
294 }
295 root_inode = hypfs_make_inode(sb, S_IFDIR | 0755);
296 if (!root_inode) {
297 rc = -ENOMEM;
298 goto err_alloc;
299 }
300 root_inode->i_op = &simple_dir_inode_operations;
301 root_inode->i_fop = &simple_dir_operations;
302 root_dentry = d_alloc_root(root_inode);
303 if (!root_dentry) {
304 iput(root_inode);
305 rc = -ENOMEM;
306 goto err_alloc;
307 }
308 if (MACHINE_IS_VM)
309 rc = hypfs_vm_create_files(sb, root_dentry);
310 else
311 rc = hypfs_diag_create_files(sb, root_dentry);
312 if (rc)
313 goto err_tree;
314 sbi->update_file = hypfs_create_update_file(sb, root_dentry);
315 if (IS_ERR(sbi->update_file)) {
316 rc = PTR_ERR(sbi->update_file);
317 goto err_tree;
318 }
319 hypfs_update_update(sb);
320 sb->s_root = root_dentry;
321 pr_info("Hypervisor filesystem mounted\n");
322 return 0;
323
324err_tree:
325 hypfs_delete_tree(root_dentry);
326 d_genocide(root_dentry);
327 dput(root_dentry);
328err_alloc:
329 kfree(sbi);
330 return rc;
331}
332
333static int hypfs_get_super(struct file_system_type *fst, int flags,
334 const char *devname, void *data, struct vfsmount *mnt)
335{
336 return get_sb_single(fst, flags, data, hypfs_fill_super, mnt);
337}
338
339static void hypfs_kill_super(struct super_block *sb)
340{
341 struct hypfs_sb_info *sb_info = sb->s_fs_info;
342
343 if (sb->s_root) {
344 hypfs_delete_tree(sb->s_root);
345 hypfs_remove(sb_info->update_file);
346 kfree(sb->s_fs_info);
347 sb->s_fs_info = NULL;
348 }
349 kill_litter_super(sb);
350}
351
352static struct dentry *hypfs_create_file(struct super_block *sb,
353 struct dentry *parent, const char *name,
354 char *data, mode_t mode)
355{
356 struct dentry *dentry;
357 struct inode *inode;
358
359 mutex_lock(&parent->d_inode->i_mutex);
360 dentry = lookup_one_len(name, parent, strlen(name));
361 if (IS_ERR(dentry)) {
362 dentry = ERR_PTR(-ENOMEM);
363 goto fail;
364 }
365 inode = hypfs_make_inode(sb, mode);
366 if (!inode) {
367 dput(dentry);
368 dentry = ERR_PTR(-ENOMEM);
369 goto fail;
370 }
371 if (mode & S_IFREG) {
372 inode->i_fop = &hypfs_file_ops;
373 if (data)
374 inode->i_size = strlen(data);
375 else
376 inode->i_size = 0;
377 } else if (mode & S_IFDIR) {
378 inode->i_op = &simple_dir_inode_operations;
379 inode->i_fop = &simple_dir_operations;
380 parent->d_inode->i_nlink++;
381 } else
382 BUG();
383 inode->i_private = data;
384 d_instantiate(dentry, inode);
385 dget(dentry);
386fail:
387 mutex_unlock(&parent->d_inode->i_mutex);
388 return dentry;
389}
390
391struct dentry *hypfs_mkdir(struct super_block *sb, struct dentry *parent,
392 const char *name)
393{
394 struct dentry *dentry;
395
396 dentry = hypfs_create_file(sb, parent, name, NULL, S_IFDIR | DIR_MODE);
397 if (IS_ERR(dentry))
398 return dentry;
399 hypfs_add_dentry(dentry);
400 return dentry;
401}
402
403static struct dentry *hypfs_create_update_file(struct super_block *sb,
404 struct dentry *dir)
405{
406 struct dentry *dentry;
407
408 dentry = hypfs_create_file(sb, dir, "update", NULL,
409 S_IFREG | UPDATE_FILE_MODE);
410
411
412
413
414
415 return dentry;
416}
417
418struct dentry *hypfs_create_u64(struct super_block *sb, struct dentry *dir,
419 const char *name, __u64 value)
420{
421 char *buffer;
422 char tmp[TMP_SIZE];
423 struct dentry *dentry;
424
425 snprintf(tmp, TMP_SIZE, "%llu\n", (unsigned long long int)value);
426 buffer = kstrdup(tmp, GFP_KERNEL);
427 if (!buffer)
428 return ERR_PTR(-ENOMEM);
429 dentry =
430 hypfs_create_file(sb, dir, name, buffer, S_IFREG | REG_FILE_MODE);
431 if (IS_ERR(dentry)) {
432 kfree(buffer);
433 return ERR_PTR(-ENOMEM);
434 }
435 hypfs_add_dentry(dentry);
436 return dentry;
437}
438
439struct dentry *hypfs_create_str(struct super_block *sb, struct dentry *dir,
440 const char *name, char *string)
441{
442 char *buffer;
443 struct dentry *dentry;
444
445 buffer = kmalloc(strlen(string) + 2, GFP_KERNEL);
446 if (!buffer)
447 return ERR_PTR(-ENOMEM);
448 sprintf(buffer, "%s\n", string);
449 dentry =
450 hypfs_create_file(sb, dir, name, buffer, S_IFREG | REG_FILE_MODE);
451 if (IS_ERR(dentry)) {
452 kfree(buffer);
453 return ERR_PTR(-ENOMEM);
454 }
455 hypfs_add_dentry(dentry);
456 return dentry;
457}
458
459static const struct file_operations hypfs_file_ops = {
460 .open = hypfs_open,
461 .release = hypfs_release,
462 .read = do_sync_read,
463 .write = do_sync_write,
464 .aio_read = hypfs_aio_read,
465 .aio_write = hypfs_aio_write,
466};
467
468static struct file_system_type hypfs_type = {
469 .owner = THIS_MODULE,
470 .name = "s390_hypfs",
471 .get_sb = hypfs_get_super,
472 .kill_sb = hypfs_kill_super
473};
474
475static const struct super_operations hypfs_s_ops = {
476 .statfs = simple_statfs,
477 .drop_inode = hypfs_drop_inode,
478 .show_options = hypfs_show_options,
479};
480
481static struct kobject *s390_kobj;
482
483static int __init hypfs_init(void)
484{
485 int rc;
486
487 if (MACHINE_IS_VM) {
488 if (hypfs_vm_init())
489
490 return -ENODATA;
491 } else {
492 if (hypfs_diag_init()) {
493 rc = -ENODATA;
494 goto fail_diag;
495 }
496 }
497 s390_kobj = kobject_create_and_add("s390", hypervisor_kobj);
498 if (!s390_kobj) {
499 rc = -ENOMEM;
500 goto fail_sysfs;
501 }
502 rc = register_filesystem(&hypfs_type);
503 if (rc)
504 goto fail_filesystem;
505 return 0;
506
507fail_filesystem:
508 kobject_put(s390_kobj);
509fail_sysfs:
510 if (!MACHINE_IS_VM)
511 hypfs_diag_exit();
512fail_diag:
513 pr_err("Initialization of hypfs failed with rc=%i\n", rc);
514 return rc;
515}
516
517static void __exit hypfs_exit(void)
518{
519 if (!MACHINE_IS_VM)
520 hypfs_diag_exit();
521 unregister_filesystem(&hypfs_type);
522 kobject_put(s390_kobj);
523}
524
525module_init(hypfs_init)
526module_exit(hypfs_exit)
527
528MODULE_LICENSE("GPL");
529MODULE_AUTHOR("Michael Holzheu <holzheu@de.ibm.com>");
530MODULE_DESCRIPTION("s390 Hypervisor Filesystem");
531