2 * arch/s390/hypfs/inode.c
3 * Hypervisor filesystem for Linux on s390.
5 * Copyright (C) IBM Corp. 2006
6 * Author(s): Michael Holzheu <holzheu@de.ibm.com>
9 #include <linux/types.h>
10 #include <linux/errno.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 <asm/ebcdic.h>
22 #include "hypfs_diag.h"
24 #define HYPFS_MAGIC 0x687970 /* ASCII 'hyp' */
25 #define TMP_SIZE 64 /* size of temporary buffers */
27 static struct dentry
*hypfs_create_update_file(struct super_block
*sb
,
30 struct hypfs_sb_info
{
31 uid_t uid
; /* uid used for files and dirs */
32 gid_t gid
; /* gid used for files and dirs */
33 struct dentry
*update_file
; /* file to trigger update */
34 time_t last_update
; /* last update time in secs since 1970 */
35 struct mutex lock
; /* lock to protect update process */
38 static struct file_operations hypfs_file_ops
;
39 static struct file_system_type hypfs_type
;
40 static struct super_operations hypfs_s_ops
;
42 /* start of list of all dentries, which have to be deleted on update */
43 static struct dentry
*hypfs_last_dentry
;
45 static void hypfs_update_update(struct super_block
*sb
)
47 struct hypfs_sb_info
*sb_info
= sb
->s_fs_info
;
48 struct inode
*inode
= sb_info
->update_file
->d_inode
;
50 sb_info
->last_update
= get_seconds();
51 inode
->i_atime
= inode
->i_mtime
= inode
->i_ctime
= CURRENT_TIME
;
54 /* directory tree removal functions */
56 static void hypfs_add_dentry(struct dentry
*dentry
)
58 dentry
->d_fsdata
= hypfs_last_dentry
;
59 hypfs_last_dentry
= dentry
;
62 static void hypfs_remove(struct dentry
*dentry
)
64 struct dentry
*parent
;
66 parent
= dentry
->d_parent
;
67 if (S_ISDIR(dentry
->d_inode
->i_mode
))
68 simple_rmdir(parent
->d_inode
, dentry
);
70 simple_unlink(parent
->d_inode
, dentry
);
75 static void hypfs_delete_tree(struct dentry
*root
)
77 while (hypfs_last_dentry
) {
78 struct dentry
*next_dentry
;
79 next_dentry
= hypfs_last_dentry
->d_fsdata
;
80 hypfs_remove(hypfs_last_dentry
);
81 hypfs_last_dentry
= next_dentry
;
85 static struct inode
*hypfs_make_inode(struct super_block
*sb
, int mode
)
87 struct inode
*ret
= new_inode(sb
);
90 struct hypfs_sb_info
*hypfs_info
= sb
->s_fs_info
;
92 ret
->i_uid
= hypfs_info
->uid
;
93 ret
->i_gid
= hypfs_info
->gid
;
95 ret
->i_atime
= ret
->i_mtime
= ret
->i_ctime
= CURRENT_TIME
;
104 static void hypfs_drop_inode(struct inode
*inode
)
106 kfree(inode
->i_private
);
107 generic_delete_inode(inode
);
110 static int hypfs_open(struct inode
*inode
, struct file
*filp
)
112 char *data
= filp
->f_dentry
->d_inode
->i_private
;
113 struct hypfs_sb_info
*fs_info
;
115 if (filp
->f_mode
& FMODE_WRITE
) {
116 if (!(inode
->i_mode
& S_IWUGO
))
119 if (filp
->f_mode
& FMODE_READ
) {
120 if (!(inode
->i_mode
& S_IRUGO
))
124 fs_info
= inode
->i_sb
->s_fs_info
;
126 mutex_lock(&fs_info
->lock
);
127 filp
->private_data
= kstrdup(data
, GFP_KERNEL
);
128 if (!filp
->private_data
) {
129 mutex_unlock(&fs_info
->lock
);
132 mutex_unlock(&fs_info
->lock
);
137 static ssize_t
hypfs_aio_read(struct kiocb
*iocb
, __user
char *buf
,
138 size_t count
, loff_t offset
)
142 struct file
*filp
= iocb
->ki_filp
;
144 data
= filp
->private_data
;
150 if (count
> len
- offset
)
151 count
= len
- offset
;
152 if (copy_to_user(buf
, data
+ offset
, count
)) {
156 iocb
->ki_pos
+= count
;
161 static ssize_t
hypfs_aio_write(struct kiocb
*iocb
, const char __user
*buf
,
162 size_t count
, loff_t pos
)
165 struct super_block
*sb
;
166 struct hypfs_sb_info
*fs_info
;
168 sb
= iocb
->ki_filp
->f_dentry
->d_inode
->i_sb
;
169 fs_info
= sb
->s_fs_info
;
171 * Currently we only allow one update per second for two reasons:
172 * 1. diag 204 is VERY expensive
173 * 2. If several processes do updates in parallel and then read the
174 * hypfs data, the likelihood of collisions is reduced, if we restrict
175 * the minimum update interval. A collision occurs, if during the
176 * data gathering of one process another process triggers an update
177 * If the first process wants to ensure consistent data, it has
178 * to restart data collection in this case.
180 mutex_lock(&fs_info
->lock
);
181 if (fs_info
->last_update
== get_seconds()) {
185 hypfs_delete_tree(sb
->s_root
);
186 rc
= hypfs_diag_create_files(sb
, sb
->s_root
);
188 printk(KERN_ERR
"hypfs: Update failed\n");
189 hypfs_delete_tree(sb
->s_root
);
192 hypfs_update_update(sb
);
195 mutex_unlock(&fs_info
->lock
);
199 static int hypfs_release(struct inode
*inode
, struct file
*filp
)
201 kfree(filp
->private_data
);
205 enum { opt_uid
, opt_gid
, opt_err
};
207 static match_table_t hypfs_tokens
= {
213 static int hypfs_parse_options(char *options
, struct super_block
*sb
)
216 substring_t args
[MAX_OPT_ARGS
];
220 while ((str
= strsep(&options
, ",")) != NULL
) {
222 struct hypfs_sb_info
*hypfs_info
= sb
->s_fs_info
;
226 token
= match_token(str
, hypfs_tokens
, args
);
229 if (match_int(&args
[0], &option
))
231 hypfs_info
->uid
= option
;
234 if (match_int(&args
[0], &option
))
236 hypfs_info
->gid
= option
;
240 printk(KERN_ERR
"hypfs: Unrecognized mount option "
241 "\"%s\" or missing value\n", str
);
248 static int hypfs_fill_super(struct super_block
*sb
, void *data
, int silent
)
250 struct inode
*root_inode
;
251 struct dentry
*root_dentry
;
253 struct hypfs_sb_info
*sbi
;
255 sbi
= kzalloc(sizeof(struct hypfs_sb_info
), GFP_KERNEL
);
258 mutex_init(&sbi
->lock
);
259 sbi
->uid
= current
->uid
;
260 sbi
->gid
= current
->gid
;
262 sb
->s_blocksize
= PAGE_CACHE_SIZE
;
263 sb
->s_blocksize_bits
= PAGE_CACHE_SHIFT
;
264 sb
->s_magic
= HYPFS_MAGIC
;
265 sb
->s_op
= &hypfs_s_ops
;
266 if (hypfs_parse_options(data
, sb
)) {
270 root_inode
= hypfs_make_inode(sb
, S_IFDIR
| 0755);
275 root_inode
->i_op
= &simple_dir_inode_operations
;
276 root_inode
->i_fop
= &simple_dir_operations
;
277 root_dentry
= d_alloc_root(root_inode
);
283 rc
= hypfs_diag_create_files(sb
, root_dentry
);
286 sbi
->update_file
= hypfs_create_update_file(sb
, root_dentry
);
287 if (IS_ERR(sbi
->update_file
)) {
288 rc
= PTR_ERR(sbi
->update_file
);
291 hypfs_update_update(sb
);
292 sb
->s_root
= root_dentry
;
296 hypfs_delete_tree(root_dentry
);
297 d_genocide(root_dentry
);
304 static int hypfs_get_super(struct file_system_type
*fst
, int flags
,
305 const char *devname
, void *data
, struct vfsmount
*mnt
)
307 return get_sb_single(fst
, flags
, data
, hypfs_fill_super
, mnt
);
310 static void hypfs_kill_super(struct super_block
*sb
)
312 struct hypfs_sb_info
*sb_info
= sb
->s_fs_info
;
315 hypfs_delete_tree(sb
->s_root
);
316 hypfs_remove(sb_info
->update_file
);
317 kfree(sb
->s_fs_info
);
318 sb
->s_fs_info
= NULL
;
320 kill_litter_super(sb
);
323 static struct dentry
*hypfs_create_file(struct super_block
*sb
,
324 struct dentry
*parent
, const char *name
,
325 char *data
, mode_t mode
)
327 struct dentry
*dentry
;
332 qname
.len
= strlen(name
);
333 qname
.hash
= full_name_hash(name
, qname
.len
);
334 dentry
= lookup_one_len(name
, parent
, strlen(name
));
336 return ERR_PTR(-ENOMEM
);
337 inode
= hypfs_make_inode(sb
, mode
);
340 return ERR_PTR(-ENOMEM
);
342 if (mode
& S_IFREG
) {
343 inode
->i_fop
= &hypfs_file_ops
;
345 inode
->i_size
= strlen(data
);
348 } else if (mode
& S_IFDIR
) {
349 inode
->i_op
= &simple_dir_inode_operations
;
350 inode
->i_fop
= &simple_dir_operations
;
351 parent
->d_inode
->i_nlink
++;
354 inode
->i_private
= data
;
355 d_instantiate(dentry
, inode
);
360 struct dentry
*hypfs_mkdir(struct super_block
*sb
, struct dentry
*parent
,
363 struct dentry
*dentry
;
365 dentry
= hypfs_create_file(sb
, parent
, name
, NULL
, S_IFDIR
| DIR_MODE
);
368 hypfs_add_dentry(dentry
);
369 parent
->d_inode
->i_nlink
++;
373 static struct dentry
*hypfs_create_update_file(struct super_block
*sb
,
376 struct dentry
*dentry
;
378 dentry
= hypfs_create_file(sb
, dir
, "update", NULL
,
379 S_IFREG
| UPDATE_FILE_MODE
);
381 * We do not put the update file on the 'delete' list with
382 * hypfs_add_dentry(), since it should not be removed when the tree
388 struct dentry
*hypfs_create_u64(struct super_block
*sb
, struct dentry
*dir
,
389 const char *name
, __u64 value
)
393 struct dentry
*dentry
;
395 snprintf(tmp
, TMP_SIZE
, "%lld\n", (unsigned long long int)value
);
396 buffer
= kstrdup(tmp
, GFP_KERNEL
);
398 return ERR_PTR(-ENOMEM
);
400 hypfs_create_file(sb
, dir
, name
, buffer
, S_IFREG
| REG_FILE_MODE
);
401 if (IS_ERR(dentry
)) {
403 return ERR_PTR(-ENOMEM
);
405 hypfs_add_dentry(dentry
);
409 struct dentry
*hypfs_create_str(struct super_block
*sb
, struct dentry
*dir
,
410 const char *name
, char *string
)
413 struct dentry
*dentry
;
415 buffer
= kmalloc(strlen(string
) + 2, GFP_KERNEL
);
417 return ERR_PTR(-ENOMEM
);
418 sprintf(buffer
, "%s\n", string
);
420 hypfs_create_file(sb
, dir
, name
, buffer
, S_IFREG
| REG_FILE_MODE
);
421 if (IS_ERR(dentry
)) {
423 return ERR_PTR(-ENOMEM
);
425 hypfs_add_dentry(dentry
);
429 static struct file_operations hypfs_file_ops
= {
431 .release
= hypfs_release
,
432 .read
= do_sync_read
,
433 .write
= do_sync_write
,
434 .aio_read
= hypfs_aio_read
,
435 .aio_write
= hypfs_aio_write
,
438 static struct file_system_type hypfs_type
= {
439 .owner
= THIS_MODULE
,
440 .name
= "s390_hypfs",
441 .get_sb
= hypfs_get_super
,
442 .kill_sb
= hypfs_kill_super
445 static struct super_operations hypfs_s_ops
= {
446 .statfs
= simple_statfs
,
447 .drop_inode
= hypfs_drop_inode
,
450 static decl_subsys(s390
, NULL
, NULL
);
452 static int __init
hypfs_init(void)
458 if (hypfs_diag_init()) {
462 kset_set_kset_s(&s390_subsys
, hypervisor_subsys
);
463 rc
= subsystem_register(&s390_subsys
);
466 rc
= register_filesystem(&hypfs_type
);
468 goto fail_filesystem
;
472 subsystem_unregister(&s390_subsys
);
476 printk(KERN_ERR
"hypfs: Initialization failed with rc = %i.\n", rc
);
480 static void __exit
hypfs_exit(void)
483 unregister_filesystem(&hypfs_type
);
484 subsystem_unregister(&s390_subsys
);
487 module_init(hypfs_init
)
488 module_exit(hypfs_exit
)
490 MODULE_LICENSE("GPL");
491 MODULE_AUTHOR("Michael Holzheu <holzheu@de.ibm.com>");
492 MODULE_DESCRIPTION("s390 Hypervisor Filesystem");