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[ALSA] via82xx - Add dxs_support for ASUS mobo
[linux-2.6/sactl.git] / fs / fuse / file.c
bloba7ef5e716f3c3dd9a36ae9fd72fc8cf987c2e610
1 /*
2 FUSE: Filesystem in Userspace
3 Copyright (C) 2001-2005 Miklos Szeredi <miklos@szeredi.hu>
4
5 This program can be distributed under the terms of the GNU GPL.
6 See the file COPYING.
7 */
8
9 #include "fuse_i.h"
10
11 #include <linux/pagemap.h>
12 #include <linux/slab.h>
13 #include <linux/kernel.h>
14
15 static struct file_operations fuse_direct_io_file_operations;
16
17 static int fuse_send_open(struct inode *inode, struct file *file, int isdir,
18 struct fuse_open_out *outargp)
19 {
20 struct fuse_conn *fc = get_fuse_conn(inode);
21 struct fuse_open_in inarg;
22 struct fuse_req *req;
23 int err;
24
25 req = fuse_get_request(fc);
26 if (!req)
27 return -EINTR;
28
29 memset(&inarg, 0, sizeof(inarg));
30 inarg.flags = file->f_flags & ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);
31 req->in.h.opcode = isdir ? FUSE_OPENDIR : FUSE_OPEN;
32 req->in.h.nodeid = get_node_id(inode);
33 req->inode = inode;
34 req->in.numargs = 1;
35 req->in.args[0].size = sizeof(inarg);
36 req->in.args[0].value = &inarg;
37 req->out.numargs = 1;
38 req->out.args[0].size = sizeof(*outargp);
39 req->out.args[0].value = outargp;
40 request_send(fc, req);
41 err = req->out.h.error;
42 fuse_put_request(fc, req);
43
44 return err;
45 }
46
47 struct fuse_file *fuse_file_alloc(void)
48 {
49 struct fuse_file *ff;
50 ff = kmalloc(sizeof(struct fuse_file), GFP_KERNEL);
51 if (ff) {
52 ff->release_req = fuse_request_alloc();
53 if (!ff->release_req) {
54 kfree(ff);
55 ff = NULL;
56 }
57 }
58 return ff;
59 }
60
61 void fuse_file_free(struct fuse_file *ff)
62 {
63 fuse_request_free(ff->release_req);
64 kfree(ff);
65 }
66
67 void fuse_finish_open(struct inode *inode, struct file *file,
68 struct fuse_file *ff, struct fuse_open_out *outarg)
69 {
70 if (outarg->open_flags & FOPEN_DIRECT_IO)
71 file->f_op = &fuse_direct_io_file_operations;
72 if (!(outarg->open_flags & FOPEN_KEEP_CACHE))
73 invalidate_inode_pages(inode->i_mapping);
74 ff->fh = outarg->fh;
75 file->private_data = ff;
76 }
77
78 int fuse_open_common(struct inode *inode, struct file *file, int isdir)
79 {
80 struct fuse_open_out outarg;
81 struct fuse_file *ff;
82 int err;
83
84 /* VFS checks this, but only _after_ ->open() */
85 if (file->f_flags & O_DIRECT)
86 return -EINVAL;
87
88 err = generic_file_open(inode, file);
89 if (err)
90 return err;
91
92 /* If opening the root node, no lookup has been performed on
93 it, so the attributes must be refreshed */
94 if (get_node_id(inode) == FUSE_ROOT_ID) {
95 err = fuse_do_getattr(inode);
96 if (err)
97 return err;
98 }
99
100 ff = fuse_file_alloc();
101 if (!ff)
102 return -ENOMEM;
103
104 err = fuse_send_open(inode, file, isdir, &outarg);
105 if (err)
106 fuse_file_free(ff);
107 else {
108 if (isdir)
109 outarg.open_flags &= ~FOPEN_DIRECT_IO;
110 fuse_finish_open(inode, file, ff, &outarg);
111 }
112
113 return err;
114 }
115
116 /* Special case for failed iget in CREATE */
117 static void fuse_release_end(struct fuse_conn *fc, struct fuse_req *req)
118 {
119 u64 nodeid = req->in.h.nodeid;
120 fuse_reset_request(req);
121 fuse_send_forget(fc, req, nodeid, 1);
122 }
123
124 void fuse_send_release(struct fuse_conn *fc, struct fuse_file *ff,
125 u64 nodeid, struct inode *inode, int flags, int isdir)
126 {
127 struct fuse_req * req = ff->release_req;
128 struct fuse_release_in *inarg = &req->misc.release_in;
129
130 inarg->fh = ff->fh;
131 inarg->flags = flags;
132 req->in.h.opcode = isdir ? FUSE_RELEASEDIR : FUSE_RELEASE;
133 req->in.h.nodeid = nodeid;
134 req->inode = inode;
135 req->in.numargs = 1;
136 req->in.args[0].size = sizeof(struct fuse_release_in);
137 req->in.args[0].value = inarg;
138 request_send_background(fc, req);
139 if (!inode)
140 req->end = fuse_release_end;
141 kfree(ff);
142 }
143
144 int fuse_release_common(struct inode *inode, struct file *file, int isdir)
145 {
146 struct fuse_file *ff = file->private_data;
147 if (ff) {
148 struct fuse_conn *fc = get_fuse_conn(inode);
149 u64 nodeid = get_node_id(inode);
150 fuse_send_release(fc, ff, nodeid, inode, file->f_flags, isdir);
151 }
152
153 /* Return value is ignored by VFS */
154 return 0;
155 }
156
157 static int fuse_open(struct inode *inode, struct file *file)
158 {
159 return fuse_open_common(inode, file, 0);
160 }
161
162 static int fuse_release(struct inode *inode, struct file *file)
163 {
164 return fuse_release_common(inode, file, 0);
165 }
166
167 static int fuse_flush(struct file *file)
168 {
169 struct inode *inode = file->f_dentry->d_inode;
170 struct fuse_conn *fc = get_fuse_conn(inode);
171 struct fuse_file *ff = file->private_data;
172 struct fuse_req *req;
173 struct fuse_flush_in inarg;
174 int err;
175
176 if (is_bad_inode(inode))
177 return -EIO;
178
179 if (fc->no_flush)
180 return 0;
181
182 req = fuse_get_request(fc);
183 if (!req)
184 return -EINTR;
185
186 memset(&inarg, 0, sizeof(inarg));
187 inarg.fh = ff->fh;
188 req->in.h.opcode = FUSE_FLUSH;
189 req->in.h.nodeid = get_node_id(inode);
190 req->inode = inode;
191 req->file = file;
192 req->in.numargs = 1;
193 req->in.args[0].size = sizeof(inarg);
194 req->in.args[0].value = &inarg;
195 request_send(fc, req);
196 err = req->out.h.error;
197 fuse_put_request(fc, req);
198 if (err == -ENOSYS) {
199 fc->no_flush = 1;
200 err = 0;
201 }
202 return err;
203 }
204
205 int fuse_fsync_common(struct file *file, struct dentry *de, int datasync,
206 int isdir)
207 {
208 struct inode *inode = de->d_inode;
209 struct fuse_conn *fc = get_fuse_conn(inode);
210 struct fuse_file *ff = file->private_data;
211 struct fuse_req *req;
212 struct fuse_fsync_in inarg;
213 int err;
214
215 if (is_bad_inode(inode))
216 return -EIO;
217
218 if ((!isdir && fc->no_fsync) || (isdir && fc->no_fsyncdir))
219 return 0;
220
221 req = fuse_get_request(fc);
222 if (!req)
223 return -EINTR;
224
225 memset(&inarg, 0, sizeof(inarg));
226 inarg.fh = ff->fh;
227 inarg.fsync_flags = datasync ? 1 : 0;
228 req->in.h.opcode = isdir ? FUSE_FSYNCDIR : FUSE_FSYNC;
229 req->in.h.nodeid = get_node_id(inode);
230 req->inode = inode;
231 req->file = file;
232 req->in.numargs = 1;
233 req->in.args[0].size = sizeof(inarg);
234 req->in.args[0].value = &inarg;
235 request_send(fc, req);
236 err = req->out.h.error;
237 fuse_put_request(fc, req);
238 if (err == -ENOSYS) {
239 if (isdir)
240 fc->no_fsyncdir = 1;
241 else
242 fc->no_fsync = 1;
243 err = 0;
244 }
245 return err;
246 }
247
248 static int fuse_fsync(struct file *file, struct dentry *de, int datasync)
249 {
250 return fuse_fsync_common(file, de, datasync, 0);
251 }
252
253 void fuse_read_fill(struct fuse_req *req, struct file *file,
254 struct inode *inode, loff_t pos, size_t count, int opcode)
255 {
256 struct fuse_file *ff = file->private_data;
257 struct fuse_read_in *inarg = &req->misc.read_in;
258
259 inarg->fh = ff->fh;
260 inarg->offset = pos;
261 inarg->size = count;
262 req->in.h.opcode = opcode;
263 req->in.h.nodeid = get_node_id(inode);
264 req->inode = inode;
265 req->file = file;
266 req->in.numargs = 1;
267 req->in.args[0].size = sizeof(struct fuse_read_in);
268 req->in.args[0].value = inarg;
269 req->out.argpages = 1;
270 req->out.argvar = 1;
271 req->out.numargs = 1;
272 req->out.args[0].size = count;
273 }
274
275 static size_t fuse_send_read(struct fuse_req *req, struct file *file,
276 struct inode *inode, loff_t pos, size_t count)
277 {
278 struct fuse_conn *fc = get_fuse_conn(inode);
279 fuse_read_fill(req, file, inode, pos, count, FUSE_READ);
280 request_send(fc, req);
281 return req->out.args[0].size;
282 }
283
284 static int fuse_readpage(struct file *file, struct page *page)
285 {
286 struct inode *inode = page->mapping->host;
287 struct fuse_conn *fc = get_fuse_conn(inode);
288 struct fuse_req *req;
289 int err;
290
291 err = -EIO;
292 if (is_bad_inode(inode))
293 goto out;
294
295 err = -EINTR;
296 req = fuse_get_request(fc);
297 if (!req)
298 goto out;
299
300 req->out.page_zeroing = 1;
301 req->num_pages = 1;
302 req->pages[0] = page;
303 fuse_send_read(req, file, inode, page_offset(page), PAGE_CACHE_SIZE);
304 err = req->out.h.error;
305 fuse_put_request(fc, req);
306 if (!err)
307 SetPageUptodate(page);
308 fuse_invalidate_attr(inode); /* atime changed */
309 out:
310 unlock_page(page);
311 return err;
312 }
313
314 static void fuse_readpages_end(struct fuse_conn *fc, struct fuse_req *req)
315 {
316 int i;
317
318 fuse_invalidate_attr(req->pages[0]->mapping->host); /* atime changed */
319
320 for (i = 0; i < req->num_pages; i++) {
321 struct page *page = req->pages[i];
322 if (!req->out.h.error)
323 SetPageUptodate(page);
324 else
325 SetPageError(page);
326 unlock_page(page);
327 }
328 fuse_put_request(fc, req);
329 }
330
331 static void fuse_send_readpages(struct fuse_req *req, struct file *file,
332 struct inode *inode)
333 {
334 struct fuse_conn *fc = get_fuse_conn(inode);
335 loff_t pos = page_offset(req->pages[0]);
336 size_t count = req->num_pages << PAGE_CACHE_SHIFT;
337 req->out.page_zeroing = 1;
338 req->end = fuse_readpages_end;
339 fuse_read_fill(req, file, inode, pos, count, FUSE_READ);
340 request_send_background(fc, req);
341 }
342
343 struct fuse_readpages_data {
344 struct fuse_req *req;
345 struct file *file;
346 struct inode *inode;
347 };
348
349 static int fuse_readpages_fill(void *_data, struct page *page)
350 {
351 struct fuse_readpages_data *data = _data;
352 struct fuse_req *req = data->req;
353 struct inode *inode = data->inode;
354 struct fuse_conn *fc = get_fuse_conn(inode);
355
356 if (req->num_pages &&
357 (req->num_pages == FUSE_MAX_PAGES_PER_REQ ||
358 (req->num_pages + 1) * PAGE_CACHE_SIZE > fc->max_read ||
359 req->pages[req->num_pages - 1]->index + 1 != page->index)) {
360 fuse_send_readpages(req, data->file, inode);
361 data->req = req = fuse_get_request(fc);
362 if (!req) {
363 unlock_page(page);
364 return -EINTR;
365 }
366 }
367 req->pages[req->num_pages] = page;
368 req->num_pages ++;
369 return 0;
370 }
371
372 static int fuse_readpages(struct file *file, struct address_space *mapping,
373 struct list_head *pages, unsigned nr_pages)
374 {
375 struct inode *inode = mapping->host;
376 struct fuse_conn *fc = get_fuse_conn(inode);
377 struct fuse_readpages_data data;
378 int err;
379
380 if (is_bad_inode(inode))
381 return -EIO;
382
383 data.file = file;
384 data.inode = inode;
385 data.req = fuse_get_request(fc);
386 if (!data.req)
387 return -EINTR;
388
389 err = read_cache_pages(mapping, pages, fuse_readpages_fill, &data);
390 if (!err)
391 fuse_send_readpages(data.req, file, inode);
392 return err;
393 }
394
395 static size_t fuse_send_write(struct fuse_req *req, struct file *file,
396 struct inode *inode, loff_t pos, size_t count)
397 {
398 struct fuse_conn *fc = get_fuse_conn(inode);
399 struct fuse_file *ff = file->private_data;
400 struct fuse_write_in inarg;
401 struct fuse_write_out outarg;
402
403 memset(&inarg, 0, sizeof(struct fuse_write_in));
404 inarg.fh = ff->fh;
405 inarg.offset = pos;
406 inarg.size = count;
407 req->in.h.opcode = FUSE_WRITE;
408 req->in.h.nodeid = get_node_id(inode);
409 req->inode = inode;
410 req->file = file;
411 req->in.argpages = 1;
412 req->in.numargs = 2;
413 req->in.args[0].size = sizeof(struct fuse_write_in);
414 req->in.args[0].value = &inarg;
415 req->in.args[1].size = count;
416 req->out.numargs = 1;
417 req->out.args[0].size = sizeof(struct fuse_write_out);
418 req->out.args[0].value = &outarg;
419 request_send(fc, req);
420 return outarg.size;
421 }
422
423 static int fuse_prepare_write(struct file *file, struct page *page,
424 unsigned offset, unsigned to)
425 {
426 /* No op */
427 return 0;
428 }
429
430 static int fuse_commit_write(struct file *file, struct page *page,
431 unsigned offset, unsigned to)
432 {
433 int err;
434 size_t nres;
435 unsigned count = to - offset;
436 struct inode *inode = page->mapping->host;
437 struct fuse_conn *fc = get_fuse_conn(inode);
438 loff_t pos = page_offset(page) + offset;
439 struct fuse_req *req;
440
441 if (is_bad_inode(inode))
442 return -EIO;
443
444 req = fuse_get_request(fc);
445 if (!req)
446 return -EINTR;
447
448 req->num_pages = 1;
449 req->pages[0] = page;
450 req->page_offset = offset;
451 nres = fuse_send_write(req, file, inode, pos, count);
452 err = req->out.h.error;
453 fuse_put_request(fc, req);
454 if (!err && nres != count)
455 err = -EIO;
456 if (!err) {
457 pos += count;
458 if (pos > i_size_read(inode))
459 i_size_write(inode, pos);
460
461 if (offset == 0 && to == PAGE_CACHE_SIZE) {
462 clear_page_dirty(page);
463 SetPageUptodate(page);
464 }
465 }
466 fuse_invalidate_attr(inode);
467 return err;
468 }
469
470 static void fuse_release_user_pages(struct fuse_req *req, int write)
471 {
472 unsigned i;
473
474 for (i = 0; i < req->num_pages; i++) {
475 struct page *page = req->pages[i];
476 if (write)
477 set_page_dirty_lock(page);
478 put_page(page);
479 }
480 }
481
482 static int fuse_get_user_pages(struct fuse_req *req, const char __user *buf,
483 unsigned nbytes, int write)
484 {
485 unsigned long user_addr = (unsigned long) buf;
486 unsigned offset = user_addr & ~PAGE_MASK;
487 int npages;
488
489 /* This doesn't work with nfsd */
490 if (!current->mm)
491 return -EPERM;
492
493 nbytes = min(nbytes, (unsigned) FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT);
494 npages = (nbytes + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
495 npages = min(max(npages, 1), FUSE_MAX_PAGES_PER_REQ);
496 down_read(&current->mm->mmap_sem);
497 npages = get_user_pages(current, current->mm, user_addr, npages, write,
498 0, req->pages, NULL);
499 up_read(&current->mm->mmap_sem);
500 if (npages < 0)
501 return npages;
502
503 req->num_pages = npages;
504 req->page_offset = offset;
505 return 0;
506 }
507
508 static ssize_t fuse_direct_io(struct file *file, const char __user *buf,
509 size_t count, loff_t *ppos, int write)
510 {
511 struct inode *inode = file->f_dentry->d_inode;
512 struct fuse_conn *fc = get_fuse_conn(inode);
513 size_t nmax = write ? fc->max_write : fc->max_read;
514 loff_t pos = *ppos;
515 ssize_t res = 0;
516 struct fuse_req *req;
517
518 if (is_bad_inode(inode))
519 return -EIO;
520
521 req = fuse_get_request(fc);
522 if (!req)
523 return -EINTR;
524
525 while (count) {
526 size_t nres;
527 size_t nbytes = min(count, nmax);
528 int err = fuse_get_user_pages(req, buf, nbytes, !write);
529 if (err) {
530 res = err;
531 break;
532 }
533 nbytes = (req->num_pages << PAGE_SHIFT) - req->page_offset;
534 nbytes = min(count, nbytes);
535 if (write)
536 nres = fuse_send_write(req, file, inode, pos, nbytes);
537 else
538 nres = fuse_send_read(req, file, inode, pos, nbytes);
539 fuse_release_user_pages(req, !write);
540 if (req->out.h.error) {
541 if (!res)
542 res = req->out.h.error;
543 break;
544 } else if (nres > nbytes) {
545 res = -EIO;
546 break;
547 }
548 count -= nres;
549 res += nres;
550 pos += nres;
551 buf += nres;
552 if (nres != nbytes)
553 break;
554 if (count)
555 fuse_reset_request(req);
556 }
557 fuse_put_request(fc, req);
558 if (res > 0) {
559 if (write && pos > i_size_read(inode))
560 i_size_write(inode, pos);
561 *ppos = pos;
562 }
563 fuse_invalidate_attr(inode);
564
565 return res;
566 }
567
568 static ssize_t fuse_direct_read(struct file *file, char __user *buf,
569 size_t count, loff_t *ppos)
570 {
571 return fuse_direct_io(file, buf, count, ppos, 0);
572 }
573
574 static ssize_t fuse_direct_write(struct file *file, const char __user *buf,
575 size_t count, loff_t *ppos)
576 {
577 struct inode *inode = file->f_dentry->d_inode;
578 ssize_t res;
579 /* Don't allow parallel writes to the same file */
580 mutex_lock(&inode->i_mutex);
581 res = fuse_direct_io(file, buf, count, ppos, 1);
582 mutex_unlock(&inode->i_mutex);
583 return res;
584 }
585
586 static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma)
587 {
588 if ((vma->vm_flags & VM_SHARED)) {
589 if ((vma->vm_flags & VM_WRITE))
590 return -ENODEV;
591 else
592 vma->vm_flags &= ~VM_MAYWRITE;
593 }
594 return generic_file_mmap(file, vma);
595 }
596
597 static int fuse_set_page_dirty(struct page *page)
598 {
599 printk("fuse_set_page_dirty: should not happen\n");
600 dump_stack();
601 return 0;
602 }
603
604 static struct file_operations fuse_file_operations = {
605 .llseek = generic_file_llseek,
606 .read = generic_file_read,
607 .write = generic_file_write,
608 .mmap = fuse_file_mmap,
609 .open = fuse_open,
610 .flush = fuse_flush,
611 .release = fuse_release,
612 .fsync = fuse_fsync,
613 .sendfile = generic_file_sendfile,
614 };
615
616 static struct file_operations fuse_direct_io_file_operations = {
617 .llseek = generic_file_llseek,
618 .read = fuse_direct_read,
619 .write = fuse_direct_write,
620 .open = fuse_open,
621 .flush = fuse_flush,
622 .release = fuse_release,
623 .fsync = fuse_fsync,
624 /* no mmap and sendfile */
625 };
626
627 static struct address_space_operations fuse_file_aops = {
628 .readpage = fuse_readpage,
629 .prepare_write = fuse_prepare_write,
630 .commit_write = fuse_commit_write,
631 .readpages = fuse_readpages,
632 .set_page_dirty = fuse_set_page_dirty,
633 };
634
635 void fuse_init_file_inode(struct inode *inode)
636 {
637 inode->i_fop = &fuse_file_operations;
638 inode->i_data.a_ops = &fuse_file_aops;
639 }
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