parisc: add pdc_coproc_cfg_unlocked and set_firmware_width_unlocked
[linux-2.6.git] / arch / s390 / hypfs / inode.c
1 /*
2  *  arch/s390/hypfs/inode.c
3  *    Hypervisor filesystem for Linux on s390.
4  *
5  *    Copyright (C) IBM Corp. 2006
6  *    Author(s): Michael Holzheu <holzheu@de.ibm.com>
7  */
8
9 #include <linux/types.h>
10 #include <linux/errno.h>
11 #include <linux/fs.h>
12 #include <linux/namei.h>
13 #include <linux/vfs.h>
14 #include <linux/pagemap.h>
15 #include <linux/gfp.h>
16 #include <linux/time.h>
17 #include <linux/parser.h>
18 #include <linux/sysfs.h>
19 #include <linux/module.h>
20 #include <linux/seq_file.h>
21 #include <linux/mount.h>
22 #include <asm/ebcdic.h>
23 #include "hypfs.h"
24
25 #define HYPFS_MAGIC 0x687970    /* ASCII 'hyp' */
26 #define TMP_SIZE 64             /* size of temporary buffers */
27
28 static struct dentry *hypfs_create_update_file(struct super_block *sb,
29                                                struct dentry *dir);
30
31 struct hypfs_sb_info {
32         uid_t uid;                      /* uid used for files and dirs */
33         gid_t gid;                      /* gid used for files and dirs */
34         struct dentry *update_file;     /* file to trigger update */
35         time_t last_update;             /* last update time in secs since 1970 */
36         struct mutex lock;              /* lock to protect update process */
37 };
38
39 static const struct file_operations hypfs_file_ops;
40 static struct file_system_type hypfs_type;
41 static struct super_operations hypfs_s_ops;
42
43 /* start of list of all dentries, which have to be deleted on update */
44 static struct dentry *hypfs_last_dentry;
45
46 static void hypfs_update_update(struct super_block *sb)
47 {
48         struct hypfs_sb_info *sb_info = sb->s_fs_info;
49         struct inode *inode = sb_info->update_file->d_inode;
50
51         sb_info->last_update = get_seconds();
52         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
53 }
54
55 /* directory tree removal functions */
56
57 static void hypfs_add_dentry(struct dentry *dentry)
58 {
59         dentry->d_fsdata = hypfs_last_dentry;
60         hypfs_last_dentry = dentry;
61 }
62
63 static inline int hypfs_positive(struct dentry *dentry)
64 {
65         return dentry->d_inode && !d_unhashed(dentry);
66 }
67
68 static void hypfs_remove(struct dentry *dentry)
69 {
70         struct dentry *parent;
71
72         parent = dentry->d_parent;
73         if (!parent || !parent->d_inode)
74                 return;
75         mutex_lock(&parent->d_inode->i_mutex);
76         if (hypfs_positive(dentry)) {
77                 if (S_ISDIR(dentry->d_inode->i_mode))
78                         simple_rmdir(parent->d_inode, dentry);
79                 else
80                         simple_unlink(parent->d_inode, dentry);
81         }
82         d_delete(dentry);
83         dput(dentry);
84         mutex_unlock(&parent->d_inode->i_mutex);
85 }
86
87 static void hypfs_delete_tree(struct dentry *root)
88 {
89         while (hypfs_last_dentry) {
90                 struct dentry *next_dentry;
91                 next_dentry = hypfs_last_dentry->d_fsdata;
92                 hypfs_remove(hypfs_last_dentry);
93                 hypfs_last_dentry = next_dentry;
94         }
95 }
96
97 static struct inode *hypfs_make_inode(struct super_block *sb, int mode)
98 {
99         struct inode *ret = new_inode(sb);
100
101         if (ret) {
102                 struct hypfs_sb_info *hypfs_info = sb->s_fs_info;
103                 ret->i_mode = mode;
104                 ret->i_uid = hypfs_info->uid;
105                 ret->i_gid = hypfs_info->gid;
106                 ret->i_blocks = 0;
107                 ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME;
108                 if (mode & S_IFDIR)
109                         ret->i_nlink = 2;
110                 else
111                         ret->i_nlink = 1;
112         }
113         return ret;
114 }
115
116 static void hypfs_drop_inode(struct inode *inode)
117 {
118         kfree(inode->i_private);
119         generic_delete_inode(inode);
120 }
121
122 static int hypfs_open(struct inode *inode, struct file *filp)
123 {
124         char *data = filp->f_path.dentry->d_inode->i_private;
125         struct hypfs_sb_info *fs_info;
126
127         if (filp->f_mode & FMODE_WRITE) {
128                 if (!(inode->i_mode & S_IWUGO))
129                         return -EACCES;
130         }
131         if (filp->f_mode & FMODE_READ) {
132                 if (!(inode->i_mode & S_IRUGO))
133                         return -EACCES;
134         }
135
136         fs_info = inode->i_sb->s_fs_info;
137         if(data) {
138                 mutex_lock(&fs_info->lock);
139                 filp->private_data = kstrdup(data, GFP_KERNEL);
140                 if (!filp->private_data) {
141                         mutex_unlock(&fs_info->lock);
142                         return -ENOMEM;
143                 }
144                 mutex_unlock(&fs_info->lock);
145         }
146         return 0;
147 }
148
149 static ssize_t hypfs_aio_read(struct kiocb *iocb, const struct iovec *iov,
150                               unsigned long nr_segs, loff_t offset)
151 {
152         char *data;
153         ssize_t ret;
154         struct file *filp = iocb->ki_filp;
155         /* XXX: temporary */
156         char __user *buf = iov[0].iov_base;
157         size_t count = iov[0].iov_len;
158
159         if (nr_segs != 1)
160                 return -EINVAL;
161
162         data = filp->private_data;
163         ret = simple_read_from_buffer(buf, count, &offset, data, strlen(data));
164         if (ret <= 0)
165                 return ret;
166
167         iocb->ki_pos += ret;
168         file_accessed(filp);
169
170         return ret;
171 }
172 static ssize_t hypfs_aio_write(struct kiocb *iocb, const struct iovec *iov,
173                               unsigned long nr_segs, loff_t offset)
174 {
175         int rc;
176         struct super_block *sb;
177         struct hypfs_sb_info *fs_info;
178         size_t count = iov_length(iov, nr_segs);
179
180         sb = iocb->ki_filp->f_path.dentry->d_inode->i_sb;
181         fs_info = sb->s_fs_info;
182         /*
183          * Currently we only allow one update per second for two reasons:
184          * 1. diag 204 is VERY expensive
185          * 2. If several processes do updates in parallel and then read the
186          *    hypfs data, the likelihood of collisions is reduced, if we restrict
187          *    the minimum update interval. A collision occurs, if during the
188          *    data gathering of one process another process triggers an update
189          *    If the first process wants to ensure consistent data, it has
190          *    to restart data collection in this case.
191          */
192         mutex_lock(&fs_info->lock);
193         if (fs_info->last_update == get_seconds()) {
194                 rc = -EBUSY;
195                 goto out;
196         }
197         hypfs_delete_tree(sb->s_root);
198         if (MACHINE_IS_VM)
199                 rc = hypfs_vm_create_files(sb, sb->s_root);
200         else
201                 rc = hypfs_diag_create_files(sb, sb->s_root);
202         if (rc) {
203                 printk(KERN_ERR "hypfs: Update failed\n");
204                 hypfs_delete_tree(sb->s_root);
205                 goto out;
206         }
207         hypfs_update_update(sb);
208         rc = count;
209 out:
210         mutex_unlock(&fs_info->lock);
211         return rc;
212 }
213
214 static int hypfs_release(struct inode *inode, struct file *filp)
215 {
216         kfree(filp->private_data);
217         return 0;
218 }
219
220 enum { opt_uid, opt_gid, opt_err };
221
222 static match_table_t hypfs_tokens = {
223         {opt_uid, "uid=%u"},
224         {opt_gid, "gid=%u"},
225         {opt_err, NULL}
226 };
227
228 static int hypfs_parse_options(char *options, struct super_block *sb)
229 {
230         char *str;
231         substring_t args[MAX_OPT_ARGS];
232
233         if (!options)
234                 return 0;
235         while ((str = strsep(&options, ",")) != NULL) {
236                 int token, option;
237                 struct hypfs_sb_info *hypfs_info = sb->s_fs_info;
238
239                 if (!*str)
240                         continue;
241                 token = match_token(str, hypfs_tokens, args);
242                 switch (token) {
243                 case opt_uid:
244                         if (match_int(&args[0], &option))
245                                 return -EINVAL;
246                         hypfs_info->uid = option;
247                         break;
248                 case opt_gid:
249                         if (match_int(&args[0], &option))
250                                 return -EINVAL;
251                         hypfs_info->gid = option;
252                         break;
253                 case opt_err:
254                 default:
255                         printk(KERN_ERR "hypfs: Unrecognized mount option "
256                                "\"%s\" or missing value\n", str);
257                         return -EINVAL;
258                 }
259         }
260         return 0;
261 }
262
263 static int hypfs_show_options(struct seq_file *s, struct vfsmount *mnt)
264 {
265         struct hypfs_sb_info *hypfs_info = mnt->mnt_sb->s_fs_info;
266
267         seq_printf(s, ",uid=%u", hypfs_info->uid);
268         seq_printf(s, ",gid=%u", hypfs_info->gid);
269         return 0;
270 }
271
272 static int hypfs_fill_super(struct super_block *sb, void *data, int silent)
273 {
274         struct inode *root_inode;
275         struct dentry *root_dentry;
276         int rc = 0;
277         struct hypfs_sb_info *sbi;
278
279         sbi = kzalloc(sizeof(struct hypfs_sb_info), GFP_KERNEL);
280         if (!sbi)
281                 return -ENOMEM;
282         mutex_init(&sbi->lock);
283         sbi->uid = current->uid;
284         sbi->gid = current->gid;
285         sb->s_fs_info = sbi;
286         sb->s_blocksize = PAGE_CACHE_SIZE;
287         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
288         sb->s_magic = HYPFS_MAGIC;
289         sb->s_op = &hypfs_s_ops;
290         if (hypfs_parse_options(data, sb)) {
291                 rc = -EINVAL;
292                 goto err_alloc;
293         }
294         root_inode = hypfs_make_inode(sb, S_IFDIR | 0755);
295         if (!root_inode) {
296                 rc = -ENOMEM;
297                 goto err_alloc;
298         }
299         root_inode->i_op = &simple_dir_inode_operations;
300         root_inode->i_fop = &simple_dir_operations;
301         root_dentry = d_alloc_root(root_inode);
302         if (!root_dentry) {
303                 iput(root_inode);
304                 rc = -ENOMEM;
305                 goto err_alloc;
306         }
307         if (MACHINE_IS_VM)
308                 rc = hypfs_vm_create_files(sb, root_dentry);
309         else
310                 rc = hypfs_diag_create_files(sb, root_dentry);
311         if (rc)
312                 goto err_tree;
313         sbi->update_file = hypfs_create_update_file(sb, root_dentry);
314         if (IS_ERR(sbi->update_file)) {
315                 rc = PTR_ERR(sbi->update_file);
316                 goto err_tree;
317         }
318         hypfs_update_update(sb);
319         sb->s_root = root_dentry;
320         printk(KERN_INFO "hypfs: Hypervisor filesystem mounted\n");
321         return 0;
322
323 err_tree:
324         hypfs_delete_tree(root_dentry);
325         d_genocide(root_dentry);
326         dput(root_dentry);
327 err_alloc:
328         kfree(sbi);
329         return rc;
330 }
331
332 static int hypfs_get_super(struct file_system_type *fst, int flags,
333                         const char *devname, void *data, struct vfsmount *mnt)
334 {
335         return get_sb_single(fst, flags, data, hypfs_fill_super, mnt);
336 }
337
338 static void hypfs_kill_super(struct super_block *sb)
339 {
340         struct hypfs_sb_info *sb_info = sb->s_fs_info;
341
342         if (sb->s_root) {
343                 hypfs_delete_tree(sb->s_root);
344                 hypfs_remove(sb_info->update_file);
345                 kfree(sb->s_fs_info);
346                 sb->s_fs_info = NULL;
347         }
348         kill_litter_super(sb);
349 }
350
351 static struct dentry *hypfs_create_file(struct super_block *sb,
352                                         struct dentry *parent, const char *name,
353                                         char *data, mode_t mode)
354 {
355         struct dentry *dentry;
356         struct inode *inode;
357         struct qstr qname;
358
359         qname.name = name;
360         qname.len = strlen(name);
361         qname.hash = full_name_hash(name, qname.len);
362         mutex_lock(&parent->d_inode->i_mutex);
363         dentry = lookup_one_len(name, parent, strlen(name));
364         if (IS_ERR(dentry)) {
365                 dentry = ERR_PTR(-ENOMEM);
366                 goto fail;
367         }
368         inode = hypfs_make_inode(sb, mode);
369         if (!inode) {
370                 dput(dentry);
371                 dentry = ERR_PTR(-ENOMEM);
372                 goto fail;
373         }
374         if (mode & S_IFREG) {
375                 inode->i_fop = &hypfs_file_ops;
376                 if (data)
377                         inode->i_size = strlen(data);
378                 else
379                         inode->i_size = 0;
380         } else if (mode & S_IFDIR) {
381                 inode->i_op = &simple_dir_inode_operations;
382                 inode->i_fop = &simple_dir_operations;
383                 parent->d_inode->i_nlink++;
384         } else
385                 BUG();
386         inode->i_private = data;
387         d_instantiate(dentry, inode);
388         dget(dentry);
389 fail:
390         mutex_unlock(&parent->d_inode->i_mutex);
391         return dentry;
392 }
393
394 struct dentry *hypfs_mkdir(struct super_block *sb, struct dentry *parent,
395                            const char *name)
396 {
397         struct dentry *dentry;
398
399         dentry = hypfs_create_file(sb, parent, name, NULL, S_IFDIR | DIR_MODE);
400         if (IS_ERR(dentry))
401                 return dentry;
402         hypfs_add_dentry(dentry);
403         return dentry;
404 }
405
406 static struct dentry *hypfs_create_update_file(struct super_block *sb,
407                                                struct dentry *dir)
408 {
409         struct dentry *dentry;
410
411         dentry = hypfs_create_file(sb, dir, "update", NULL,
412                                    S_IFREG | UPDATE_FILE_MODE);
413         /*
414          * We do not put the update file on the 'delete' list with
415          * hypfs_add_dentry(), since it should not be removed when the tree
416          * is updated.
417          */
418         return dentry;
419 }
420
421 struct dentry *hypfs_create_u64(struct super_block *sb, struct dentry *dir,
422                                 const char *name, __u64 value)
423 {
424         char *buffer;
425         char tmp[TMP_SIZE];
426         struct dentry *dentry;
427
428         snprintf(tmp, TMP_SIZE, "%lld\n", (unsigned long long int)value);
429         buffer = kstrdup(tmp, GFP_KERNEL);
430         if (!buffer)
431                 return ERR_PTR(-ENOMEM);
432         dentry =
433             hypfs_create_file(sb, dir, name, buffer, S_IFREG | REG_FILE_MODE);
434         if (IS_ERR(dentry)) {
435                 kfree(buffer);
436                 return ERR_PTR(-ENOMEM);
437         }
438         hypfs_add_dentry(dentry);
439         return dentry;
440 }
441
442 struct dentry *hypfs_create_str(struct super_block *sb, struct dentry *dir,
443                                 const char *name, char *string)
444 {
445         char *buffer;
446         struct dentry *dentry;
447
448         buffer = kmalloc(strlen(string) + 2, GFP_KERNEL);
449         if (!buffer)
450                 return ERR_PTR(-ENOMEM);
451         sprintf(buffer, "%s\n", string);
452         dentry =
453             hypfs_create_file(sb, dir, name, buffer, S_IFREG | REG_FILE_MODE);
454         if (IS_ERR(dentry)) {
455                 kfree(buffer);
456                 return ERR_PTR(-ENOMEM);
457         }
458         hypfs_add_dentry(dentry);
459         return dentry;
460 }
461
462 static const struct file_operations hypfs_file_ops = {
463         .open           = hypfs_open,
464         .release        = hypfs_release,
465         .read           = do_sync_read,
466         .write          = do_sync_write,
467         .aio_read       = hypfs_aio_read,
468         .aio_write      = hypfs_aio_write,
469 };
470
471 static struct file_system_type hypfs_type = {
472         .owner          = THIS_MODULE,
473         .name           = "s390_hypfs",
474         .get_sb         = hypfs_get_super,
475         .kill_sb        = hypfs_kill_super
476 };
477
478 static struct super_operations hypfs_s_ops = {
479         .statfs         = simple_statfs,
480         .drop_inode     = hypfs_drop_inode,
481         .show_options   = hypfs_show_options,
482 };
483
484 static struct kobject *s390_kobj;
485
486 static int __init hypfs_init(void)
487 {
488         int rc;
489
490         if (MACHINE_IS_VM) {
491                 if (hypfs_vm_init())
492                         /* no diag 2fc, just exit */
493                         return -ENODATA;
494         } else {
495                 if (hypfs_diag_init()) {
496                         rc = -ENODATA;
497                         goto fail_diag;
498                 }
499         }
500         s390_kobj = kobject_create_and_add("s390", hypervisor_kobj);
501         if (!s390_kobj) {
502                 rc = -ENOMEM;;
503                 goto fail_sysfs;
504         }
505         rc = register_filesystem(&hypfs_type);
506         if (rc)
507                 goto fail_filesystem;
508         return 0;
509
510 fail_filesystem:
511         kobject_put(s390_kobj);
512 fail_sysfs:
513         if (!MACHINE_IS_VM)
514                 hypfs_diag_exit();
515 fail_diag:
516         printk(KERN_ERR "hypfs: Initialization failed with rc = %i.\n", rc);
517         return rc;
518 }
519
520 static void __exit hypfs_exit(void)
521 {
522         if (!MACHINE_IS_VM)
523                 hypfs_diag_exit();
524         unregister_filesystem(&hypfs_type);
525         kobject_put(s390_kobj);
526 }
527
528 module_init(hypfs_init)
529 module_exit(hypfs_exit)
530
531 MODULE_LICENSE("GPL");
532 MODULE_AUTHOR("Michael Holzheu <holzheu@de.ibm.com>");
533 MODULE_DESCRIPTION("s390 Hypervisor Filesystem");