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[JFFS2] fix sparse warning in write.c
[linux-2.6/openmoko-kernel.git] / fs / hppfs / hppfs_kern.c
blob8601d8ef3b550d1c803c3a5bb7cd37f831717fd2
1 /*
2 * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3 * Licensed under the GPL
4 */
5
6 #include <linux/ctype.h>
7 #include <linux/dcache.h>
8 #include <linux/file.h>
9 #include <linux/fs.h>
10 #include <linux/init.h>
11 #include <linux/kernel.h>
12 #include <linux/list.h>
13 #include <linux/module.h>
14 #include <linux/mount.h>
15 #include <linux/slab.h>
16 #include <linux/statfs.h>
17 #include <linux/types.h>
18 #include <asm/uaccess.h>
19 #include "os.h"
20
21 static struct inode *get_inode(struct super_block *, struct dentry *);
22
23 struct hppfs_data {
24 struct list_head list;
25 char contents[PAGE_SIZE - sizeof(struct list_head)];
26 };
27
28 struct hppfs_private {
29 struct file *proc_file;
30 int host_fd;
31 loff_t len;
32 struct hppfs_data *contents;
33 };
34
35 struct hppfs_inode_info {
36 struct dentry *proc_dentry;
37 struct inode vfs_inode;
38 };
39
40 static inline struct hppfs_inode_info *HPPFS_I(struct inode *inode)
41 {
42 return container_of(inode, struct hppfs_inode_info, vfs_inode);
43 }
44
45 #define HPPFS_SUPER_MAGIC 0xb00000ee
46
47 static const struct super_operations hppfs_sbops;
48
49 static int is_pid(struct dentry *dentry)
50 {
51 struct super_block *sb;
52 int i;
53
54 sb = dentry->d_sb;
55 if ((sb->s_op != &hppfs_sbops) || (dentry->d_parent != sb->s_root))
56 return 0;
57
58 for (i = 0; i < dentry->d_name.len; i++) {
59 if (!isdigit(dentry->d_name.name[i]))
60 return 0;
61 }
62 return 1;
63 }
64
65 static char *dentry_name(struct dentry *dentry, int extra)
66 {
67 struct dentry *parent;
68 char *root, *name;
69 const char *seg_name;
70 int len, seg_len;
71
72 len = 0;
73 parent = dentry;
74 while (parent->d_parent != parent) {
75 if (is_pid(parent))
76 len += strlen("pid") + 1;
77 else len += parent->d_name.len + 1;
78 parent = parent->d_parent;
79 }
80
81 root = "proc";
82 len += strlen(root);
83 name = kmalloc(len + extra + 1, GFP_KERNEL);
84 if (name == NULL)
85 return NULL;
86
87 name[len] = '\0';
88 parent = dentry;
89 while (parent->d_parent != parent) {
90 if (is_pid(parent)) {
91 seg_name = "pid";
92 seg_len = strlen("pid");
93 }
94 else {
95 seg_name = parent->d_name.name;
96 seg_len = parent->d_name.len;
97 }
98
99 len -= seg_len + 1;
100 name[len] = '/';
101 strncpy(&name[len + 1], seg_name, seg_len);
102 parent = parent->d_parent;
103 }
104 strncpy(name, root, strlen(root));
105 return name;
106 }
107
108 static int file_removed(struct dentry *dentry, const char *file)
109 {
110 char *host_file;
111 int extra, fd;
112
113 extra = 0;
114 if (file != NULL)
115 extra += strlen(file) + 1;
116
117 host_file = dentry_name(dentry, extra + strlen("/remove"));
118 if (host_file == NULL) {
119 printk(KERN_ERR "file_removed : allocation failed\n");
120 return -ENOMEM;
121 }
122
123 if (file != NULL) {
124 strcat(host_file, "/");
125 strcat(host_file, file);
126 }
127 strcat(host_file, "/remove");
128
129 fd = os_open_file(host_file, of_read(OPENFLAGS()), 0);
130 kfree(host_file);
131 if (fd > 0) {
132 os_close_file(fd);
133 return 1;
134 }
135 return 0;
136 }
137
138 static struct dentry *hppfs_lookup(struct inode *ino, struct dentry *dentry,
139 struct nameidata *nd)
140 {
141 struct dentry *proc_dentry, *new, *parent;
142 struct inode *inode;
143 int err, deleted;
144
145 deleted = file_removed(dentry, NULL);
146 if (deleted < 0)
147 return ERR_PTR(deleted);
148 else if (deleted)
149 return ERR_PTR(-ENOENT);
150
151 err = -ENOMEM;
152 parent = HPPFS_I(ino)->proc_dentry;
153 mutex_lock(&parent->d_inode->i_mutex);
154 proc_dentry = d_lookup(parent, &dentry->d_name);
155 if (proc_dentry == NULL) {
156 proc_dentry = d_alloc(parent, &dentry->d_name);
157 if (proc_dentry == NULL) {
158 mutex_unlock(&parent->d_inode->i_mutex);
159 goto out;
160 }
161 new = (*parent->d_inode->i_op->lookup)(parent->d_inode,
162 proc_dentry, NULL);
163 if (new) {
164 dput(proc_dentry);
165 proc_dentry = new;
166 }
167 }
168 mutex_unlock(&parent->d_inode->i_mutex);
169
170 if (IS_ERR(proc_dentry))
171 return proc_dentry;
172
173 err = -ENOMEM;
174 inode = get_inode(ino->i_sb, proc_dentry);
175 if (!inode)
176 goto out_dput;
177
178 d_add(dentry, inode);
179 return NULL;
180
181 out_dput:
182 dput(proc_dentry);
183 out:
184 return ERR_PTR(err);
185 }
186
187 static const struct inode_operations hppfs_file_iops = {
188 };
189
190 static ssize_t read_proc(struct file *file, char __user *buf, ssize_t count,
191 loff_t *ppos, int is_user)
192 {
193 ssize_t (*read)(struct file *, char __user *, size_t, loff_t *);
194 ssize_t n;
195
196 read = file->f_path.dentry->d_inode->i_fop->read;
197
198 if (!is_user)
199 set_fs(KERNEL_DS);
200
201 n = (*read)(file, buf, count, &file->f_pos);
202
203 if (!is_user)
204 set_fs(USER_DS);
205
206 if (ppos)
207 *ppos = file->f_pos;
208 return n;
209 }
210
211 static ssize_t hppfs_read_file(int fd, char __user *buf, ssize_t count)
212 {
213 ssize_t n;
214 int cur, err;
215 char *new_buf;
216
217 n = -ENOMEM;
218 new_buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
219 if (new_buf == NULL) {
220 printk(KERN_ERR "hppfs_read_file : kmalloc failed\n");
221 goto out;
222 }
223 n = 0;
224 while (count > 0) {
225 cur = min_t(ssize_t, count, PAGE_SIZE);
226 err = os_read_file(fd, new_buf, cur);
227 if (err < 0) {
228 printk(KERN_ERR "hppfs_read : read failed, "
229 "errno = %d\n", err);
230 n = err;
231 goto out_free;
232 } else if (err == 0)
233 break;
234
235 if (copy_to_user(buf, new_buf, err)) {
236 n = -EFAULT;
237 goto out_free;
238 }
239 n += err;
240 count -= err;
241 }
242 out_free:
243 kfree(new_buf);
244 out:
245 return n;
246 }
247
248 static ssize_t hppfs_read(struct file *file, char __user *buf, size_t count,
249 loff_t *ppos)
250 {
251 struct hppfs_private *hppfs = file->private_data;
252 struct hppfs_data *data;
253 loff_t off;
254 int err;
255
256 if (hppfs->contents != NULL) {
257 if (*ppos >= hppfs->len)
258 return 0;
259
260 data = hppfs->contents;
261 off = *ppos;
262 while (off >= sizeof(data->contents)) {
263 data = list_entry(data->list.next, struct hppfs_data,
264 list);
265 off -= sizeof(data->contents);
266 }
267
268 if (off + count > hppfs->len)
269 count = hppfs->len - off;
270 copy_to_user(buf, &data->contents[off], count);
271 *ppos += count;
272 } else if (hppfs->host_fd != -1) {
273 err = os_seek_file(hppfs->host_fd, *ppos);
274 if (err) {
275 printk(KERN_ERR "hppfs_read : seek failed, "
276 "errno = %d\n", err);
277 return err;
278 }
279 count = hppfs_read_file(hppfs->host_fd, buf, count);
280 if (count > 0)
281 *ppos += count;
282 }
283 else count = read_proc(hppfs->proc_file, buf, count, ppos, 1);
284
285 return count;
286 }
287
288 static ssize_t hppfs_write(struct file *file, const char __user *buf, size_t len,
289 loff_t *ppos)
290 {
291 struct hppfs_private *data = file->private_data;
292 struct file *proc_file = data->proc_file;
293 ssize_t (*write)(struct file *, const char __user *, size_t, loff_t *);
294 int err;
295
296 write = proc_file->f_path.dentry->d_inode->i_fop->write;
297
298 proc_file->f_pos = file->f_pos;
299 err = (*write)(proc_file, buf, len, &proc_file->f_pos);
300 file->f_pos = proc_file->f_pos;
301
302 return err;
303 }
304
305 static int open_host_sock(char *host_file, int *filter_out)
306 {
307 char *end;
308 int fd;
309
310 end = &host_file[strlen(host_file)];
311 strcpy(end, "/rw");
312 *filter_out = 1;
313 fd = os_connect_socket(host_file);
314 if (fd > 0)
315 return fd;
316
317 strcpy(end, "/r");
318 *filter_out = 0;
319 fd = os_connect_socket(host_file);
320 return fd;
321 }
322
323 static void free_contents(struct hppfs_data *head)
324 {
325 struct hppfs_data *data;
326 struct list_head *ele, *next;
327
328 if (head == NULL)
329 return;
330
331 list_for_each_safe(ele, next, &head->list) {
332 data = list_entry(ele, struct hppfs_data, list);
333 kfree(data);
334 }
335 kfree(head);
336 }
337
338 static struct hppfs_data *hppfs_get_data(int fd, int filter,
339 struct file *proc_file,
340 struct file *hppfs_file,
341 loff_t *size_out)
342 {
343 struct hppfs_data *data, *new, *head;
344 int n, err;
345
346 err = -ENOMEM;
347 data = kmalloc(sizeof(*data), GFP_KERNEL);
348 if (data == NULL) {
349 printk(KERN_ERR "hppfs_get_data : head allocation failed\n");
350 goto failed;
351 }
352
353 INIT_LIST_HEAD(&data->list);
354
355 head = data;
356 *size_out = 0;
357
358 if (filter) {
359 while ((n = read_proc(proc_file, data->contents,
360 sizeof(data->contents), NULL, 0)) > 0)
361 os_write_file(fd, data->contents, n);
362 err = os_shutdown_socket(fd, 0, 1);
363 if (err) {
364 printk(KERN_ERR "hppfs_get_data : failed to shut down "
365 "socket\n");
366 goto failed_free;
367 }
368 }
369 while (1) {
370 n = os_read_file(fd, data->contents, sizeof(data->contents));
371 if (n < 0) {
372 err = n;
373 printk(KERN_ERR "hppfs_get_data : read failed, "
374 "errno = %d\n", err);
375 goto failed_free;
376 } else if (n == 0)
377 break;
378
379 *size_out += n;
380
381 if (n < sizeof(data->contents))
382 break;
383
384 new = kmalloc(sizeof(*data), GFP_KERNEL);
385 if (new == 0) {
386 printk(KERN_ERR "hppfs_get_data : data allocation "
387 "failed\n");
388 err = -ENOMEM;
389 goto failed_free;
390 }
391
392 INIT_LIST_HEAD(&new->list);
393 list_add(&new->list, &data->list);
394 data = new;
395 }
396 return head;
397
398 failed_free:
399 free_contents(head);
400 failed:
401 return ERR_PTR(err);
402 }
403
404 static struct hppfs_private *hppfs_data(void)
405 {
406 struct hppfs_private *data;
407
408 data = kmalloc(sizeof(*data), GFP_KERNEL);
409 if (data == NULL)
410 return data;
411
412 *data = ((struct hppfs_private ) { .host_fd = -1,
413 .len = -1,
414 .contents = NULL } );
415 return data;
416 }
417
418 static int file_mode(int fmode)
419 {
420 if (fmode == (FMODE_READ | FMODE_WRITE))
421 return O_RDWR;
422 if (fmode == FMODE_READ)
423 return O_RDONLY;
424 if (fmode == FMODE_WRITE)
425 return O_WRONLY;
426 return 0;
427 }
428
429 static int hppfs_open(struct inode *inode, struct file *file)
430 {
431 struct hppfs_private *data;
432 struct dentry *proc_dentry;
433 struct vfsmount *proc_mnt;
434 char *host_file;
435 int err, fd, type, filter;
436
437 err = -ENOMEM;
438 data = hppfs_data();
439 if (data == NULL)
440 goto out;
441
442 host_file = dentry_name(file->f_path.dentry, strlen("/rw"));
443 if (host_file == NULL)
444 goto out_free2;
445
446 proc_dentry = HPPFS_I(inode)->proc_dentry;
447 proc_mnt = inode->i_sb->s_fs_info;
448
449 /* XXX This isn't closed anywhere */
450 data->proc_file = dentry_open(dget(proc_dentry), mntget(proc_mnt),
451 file_mode(file->f_mode));
452 err = PTR_ERR(data->proc_file);
453 if (IS_ERR(data->proc_file))
454 goto out_free1;
455
456 type = os_file_type(host_file);
457 if (type == OS_TYPE_FILE) {
458 fd = os_open_file(host_file, of_read(OPENFLAGS()), 0);
459 if (fd >= 0)
460 data->host_fd = fd;
461 else
462 printk(KERN_ERR "hppfs_open : failed to open '%s', "
463 "errno = %d\n", host_file, -fd);
464
465 data->contents = NULL;
466 } else if (type == OS_TYPE_DIR) {
467 fd = open_host_sock(host_file, &filter);
468 if (fd > 0) {
469 data->contents = hppfs_get_data(fd, filter,
470 data->proc_file,
471 file, &data->len);
472 if (!IS_ERR(data->contents))
473 data->host_fd = fd;
474 } else
475 printk(KERN_ERR "hppfs_open : failed to open a socket "
476 "in '%s', errno = %d\n", host_file, -fd);
477 }
478 kfree(host_file);
479
480 file->private_data = data;
481 return 0;
482
483 out_free1:
484 kfree(host_file);
485 out_free2:
486 free_contents(data->contents);
487 kfree(data);
488 out:
489 return err;
490 }
491
492 static int hppfs_dir_open(struct inode *inode, struct file *file)
493 {
494 struct hppfs_private *data;
495 struct dentry *proc_dentry;
496 struct vfsmount *proc_mnt;
497 int err;
498
499 err = -ENOMEM;
500 data = hppfs_data();
501 if (data == NULL)
502 goto out;
503
504 proc_dentry = HPPFS_I(inode)->proc_dentry;
505 proc_mnt = inode->i_sb->s_fs_info;
506 data->proc_file = dentry_open(dget(proc_dentry), mntget(proc_mnt),
507 file_mode(file->f_mode));
508 err = PTR_ERR(data->proc_file);
509 if (IS_ERR(data->proc_file))
510 goto out_free;
511
512 file->private_data = data;
513 return 0;
514
515 out_free:
516 kfree(data);
517 out:
518 return err;
519 }
520
521 static loff_t hppfs_llseek(struct file *file, loff_t off, int where)
522 {
523 struct hppfs_private *data = file->private_data;
524 struct file *proc_file = data->proc_file;
525 loff_t (*llseek)(struct file *, loff_t, int);
526 loff_t ret;
527
528 llseek = proc_file->f_path.dentry->d_inode->i_fop->llseek;
529 if (llseek != NULL) {
530 ret = (*llseek)(proc_file, off, where);
531 if (ret < 0)
532 return ret;
533 }
534
535 return default_llseek(file, off, where);
536 }
537
538 static const struct file_operations hppfs_file_fops = {
539 .owner = NULL,
540 .llseek = hppfs_llseek,
541 .read = hppfs_read,
542 .write = hppfs_write,
543 .open = hppfs_open,
544 };
545
546 struct hppfs_dirent {
547 void *vfs_dirent;
548 filldir_t filldir;
549 struct dentry *dentry;
550 };
551
552 static int hppfs_filldir(void *d, const char *name, int size,
553 loff_t offset, u64 inode, unsigned int type)
554 {
555 struct hppfs_dirent *dirent = d;
556
557 if (file_removed(dirent->dentry, name))
558 return 0;
559
560 return (*dirent->filldir)(dirent->vfs_dirent, name, size, offset,
561 inode, type);
562 }
563
564 static int hppfs_readdir(struct file *file, void *ent, filldir_t filldir)
565 {
566 struct hppfs_private *data = file->private_data;
567 struct file *proc_file = data->proc_file;
568 int (*readdir)(struct file *, void *, filldir_t);
569 struct hppfs_dirent dirent = ((struct hppfs_dirent)
570 { .vfs_dirent = ent,
571 .filldir = filldir,
572 .dentry = file->f_path.dentry
573 });
574 int err;
575
576 readdir = proc_file->f_path.dentry->d_inode->i_fop->readdir;
577
578 proc_file->f_pos = file->f_pos;
579 err = (*readdir)(proc_file, &dirent, hppfs_filldir);
580 file->f_pos = proc_file->f_pos;
581
582 return err;
583 }
584
585 static int hppfs_fsync(struct file *file, struct dentry *dentry, int datasync)
586 {
587 return 0;
588 }
589
590 static const struct file_operations hppfs_dir_fops = {
591 .owner = NULL,
592 .readdir = hppfs_readdir,
593 .open = hppfs_dir_open,
594 .fsync = hppfs_fsync,
595 };
596
597 static int hppfs_statfs(struct dentry *dentry, struct kstatfs *sf)
598 {
599 sf->f_blocks = 0;
600 sf->f_bfree = 0;
601 sf->f_bavail = 0;
602 sf->f_files = 0;
603 sf->f_ffree = 0;
604 sf->f_type = HPPFS_SUPER_MAGIC;
605 return 0;
606 }
607
608 static struct inode *hppfs_alloc_inode(struct super_block *sb)
609 {
610 struct hppfs_inode_info *hi;
611
612 hi = kmalloc(sizeof(*hi), GFP_KERNEL);
613 if (!hi)
614 return NULL;
615
616 hi->proc_dentry = NULL;
617 inode_init_once(&hi->vfs_inode);
618 return &hi->vfs_inode;
619 }
620
621 void hppfs_delete_inode(struct inode *ino)
622 {
623 clear_inode(ino);
624 }
625
626 static void hppfs_destroy_inode(struct inode *inode)
627 {
628 kfree(HPPFS_I(inode));
629 }
630
631 static void hppfs_put_super(struct super_block *sb)
632 {
633 mntput(sb->s_fs_info);
634 }
635
636 static const struct super_operations hppfs_sbops = {
637 .alloc_inode = hppfs_alloc_inode,
638 .destroy_inode = hppfs_destroy_inode,
639 .delete_inode = hppfs_delete_inode,
640 .statfs = hppfs_statfs,
641 .put_super = hppfs_put_super,
642 };
643
644 static int hppfs_readlink(struct dentry *dentry, char __user *buffer,
645 int buflen)
646 {
647 struct file *proc_file;
648 struct dentry *proc_dentry;
649 struct vfsmount *proc_mnt;
650 int ret;
651
652 proc_dentry = HPPFS_I(dentry->d_inode)->proc_dentry;
653 proc_mnt = dentry->d_sb->s_fs_info;
654
655 proc_file = dentry_open(dget(proc_dentry), mntget(proc_mnt), O_RDONLY);
656 if (IS_ERR(proc_file))
657 return PTR_ERR(proc_file);
658
659 ret = proc_dentry->d_inode->i_op->readlink(proc_dentry, buffer, buflen);
660
661 fput(proc_file);
662
663 return ret;
664 }
665
666 static void* hppfs_follow_link(struct dentry *dentry, struct nameidata *nd)
667 {
668 struct file *proc_file;
669 struct dentry *proc_dentry;
670 struct vfsmount *proc_mnt;
671 void *ret;
672
673 proc_dentry = HPPFS_I(dentry->d_inode)->proc_dentry;
674 proc_mnt = dentry->d_sb->s_fs_info;
675
676 proc_file = dentry_open(dget(proc_dentry), mntget(proc_mnt), O_RDONLY);
677 if (IS_ERR(proc_file))
678 return proc_file;
679
680 ret = proc_dentry->d_inode->i_op->follow_link(proc_dentry, nd);
681
682 fput(proc_file);
683
684 return ret;
685 }
686
687 static const struct inode_operations hppfs_dir_iops = {
688 .lookup = hppfs_lookup,
689 };
690
691 static const struct inode_operations hppfs_link_iops = {
692 .readlink = hppfs_readlink,
693 .follow_link = hppfs_follow_link,
694 };
695
696 static struct inode *get_inode(struct super_block *sb, struct dentry *dentry)
697 {
698 struct inode *proc_ino = dentry->d_inode;
699 struct inode *inode = new_inode(sb);
700
701 if (!inode)
702 return ERR_PTR(-ENOMEM);
703
704 if (S_ISDIR(dentry->d_inode->i_mode)) {
705 inode->i_op = &hppfs_dir_iops;
706 inode->i_fop = &hppfs_dir_fops;
707 } else if (S_ISLNK(dentry->d_inode->i_mode)) {
708 inode->i_op = &hppfs_link_iops;
709 inode->i_fop = &hppfs_file_fops;
710 } else {
711 inode->i_op = &hppfs_file_iops;
712 inode->i_fop = &hppfs_file_fops;
713 }
714
715 HPPFS_I(inode)->proc_dentry = dentry;
716
717 inode->i_uid = proc_ino->i_uid;
718 inode->i_gid = proc_ino->i_gid;
719 inode->i_atime = proc_ino->i_atime;
720 inode->i_mtime = proc_ino->i_mtime;
721 inode->i_ctime = proc_ino->i_ctime;
722 inode->i_ino = proc_ino->i_ino;
723 inode->i_mode = proc_ino->i_mode;
724 inode->i_nlink = proc_ino->i_nlink;
725 inode->i_size = proc_ino->i_size;
726 inode->i_blocks = proc_ino->i_blocks;
727
728 return 0;
729 }
730
731 static int hppfs_fill_super(struct super_block *sb, void *d, int silent)
732 {
733 struct inode *root_inode;
734 struct vfsmount *proc_mnt;
735 int err = -ENOENT;
736
737 proc_mnt = do_kern_mount("proc", 0, "proc", NULL);
738 if (IS_ERR(proc_mnt))
739 goto out;
740
741 sb->s_blocksize = 1024;
742 sb->s_blocksize_bits = 10;
743 sb->s_magic = HPPFS_SUPER_MAGIC;
744 sb->s_op = &hppfs_sbops;
745 sb->s_fs_info = proc_mnt;
746
747 err = -ENOMEM;
748 root_inode = get_inode(sb, proc_mnt->mnt_sb->s_root);
749 if (!root_inode)
750 goto out_mntput;
751
752 sb->s_root = d_alloc_root(root_inode);
753 if (!sb->s_root)
754 goto out_iput;
755
756 return 0;
757
758 out_iput:
759 iput(root_inode);
760 out_mntput:
761 mntput(proc_mnt);
762 out:
763 return(err);
764 }
765
766 static int hppfs_read_super(struct file_system_type *type,
767 int flags, const char *dev_name,
768 void *data, struct vfsmount *mnt)
769 {
770 return get_sb_nodev(type, flags, data, hppfs_fill_super, mnt);
771 }
772
773 static struct file_system_type hppfs_type = {
774 .owner = THIS_MODULE,
775 .name = "hppfs",
776 .get_sb = hppfs_read_super,
777 .kill_sb = kill_anon_super,
778 .fs_flags = 0,
779 };
780
781 static int __init init_hppfs(void)
782 {
783 return register_filesystem(&hppfs_type);
784 }
785
786 static void __exit exit_hppfs(void)
787 {
788 unregister_filesystem(&hppfs_type);
789 }
790
791 module_init(init_hppfs)
792 module_exit(exit_hppfs)
793 MODULE_LICENSE("GPL");
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