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fuse: add helper for asynchronous writes
[wandboard.git] / fs / fuse / file.c
blob2b589de044e8be904b4b635c2155db9926188931
1 /*
2 FUSE: Filesystem in Userspace
3 Copyright (C) 2001-2006 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 #include <linux/sched.h>
15
16 static const struct file_operations fuse_direct_io_file_operations;
17
18 static int fuse_send_open(struct inode *inode, struct file *file, int isdir,
19 struct fuse_open_out *outargp)
20 {
21 struct fuse_conn *fc = get_fuse_conn(inode);
22 struct fuse_open_in inarg;
23 struct fuse_req *req;
24 int err;
25
26 req = fuse_get_req(fc);
27 if (IS_ERR(req))
28 return PTR_ERR(req);
29
30 memset(&inarg, 0, sizeof(inarg));
31 inarg.flags = file->f_flags & ~(O_CREAT | O_EXCL | O_NOCTTY);
32 if (!fc->atomic_o_trunc)
33 inarg.flags &= ~O_TRUNC;
34 req->in.h.opcode = isdir ? FUSE_OPENDIR : FUSE_OPEN;
35 req->in.h.nodeid = get_node_id(inode);
36 req->in.numargs = 1;
37 req->in.args[0].size = sizeof(inarg);
38 req->in.args[0].value = &inarg;
39 req->out.numargs = 1;
40 req->out.args[0].size = sizeof(*outargp);
41 req->out.args[0].value = outargp;
42 request_send(fc, req);
43 err = req->out.h.error;
44 fuse_put_request(fc, req);
45
46 return err;
47 }
48
49 struct fuse_file *fuse_file_alloc(void)
50 {
51 struct fuse_file *ff;
52 ff = kmalloc(sizeof(struct fuse_file), GFP_KERNEL);
53 if (ff) {
54 ff->reserved_req = fuse_request_alloc();
55 if (!ff->reserved_req) {
56 kfree(ff);
57 ff = NULL;
58 }
59 INIT_LIST_HEAD(&ff->write_entry);
60 atomic_set(&ff->count, 0);
61 }
62 return ff;
63 }
64
65 void fuse_file_free(struct fuse_file *ff)
66 {
67 fuse_request_free(ff->reserved_req);
68 kfree(ff);
69 }
70
71 static struct fuse_file *fuse_file_get(struct fuse_file *ff)
72 {
73 atomic_inc(&ff->count);
74 return ff;
75 }
76
77 static void fuse_release_end(struct fuse_conn *fc, struct fuse_req *req)
78 {
79 dput(req->dentry);
80 mntput(req->vfsmount);
81 fuse_put_request(fc, req);
82 }
83
84 static void fuse_file_put(struct fuse_file *ff)
85 {
86 if (atomic_dec_and_test(&ff->count)) {
87 struct fuse_req *req = ff->reserved_req;
88 struct fuse_conn *fc = get_fuse_conn(req->dentry->d_inode);
89 req->end = fuse_release_end;
90 request_send_background(fc, req);
91 kfree(ff);
92 }
93 }
94
95 void fuse_finish_open(struct inode *inode, struct file *file,
96 struct fuse_file *ff, struct fuse_open_out *outarg)
97 {
98 if (outarg->open_flags & FOPEN_DIRECT_IO)
99 file->f_op = &fuse_direct_io_file_operations;
100 if (!(outarg->open_flags & FOPEN_KEEP_CACHE))
101 invalidate_inode_pages2(inode->i_mapping);
102 ff->fh = outarg->fh;
103 file->private_data = fuse_file_get(ff);
104 }
105
106 int fuse_open_common(struct inode *inode, struct file *file, int isdir)
107 {
108 struct fuse_open_out outarg;
109 struct fuse_file *ff;
110 int err;
111
112 /* VFS checks this, but only _after_ ->open() */
113 if (file->f_flags & O_DIRECT)
114 return -EINVAL;
115
116 err = generic_file_open(inode, file);
117 if (err)
118 return err;
119
120 ff = fuse_file_alloc();
121 if (!ff)
122 return -ENOMEM;
123
124 err = fuse_send_open(inode, file, isdir, &outarg);
125 if (err)
126 fuse_file_free(ff);
127 else {
128 if (isdir)
129 outarg.open_flags &= ~FOPEN_DIRECT_IO;
130 fuse_finish_open(inode, file, ff, &outarg);
131 }
132
133 return err;
134 }
135
136 void fuse_release_fill(struct fuse_file *ff, u64 nodeid, int flags, int opcode)
137 {
138 struct fuse_req *req = ff->reserved_req;
139 struct fuse_release_in *inarg = &req->misc.release_in;
140
141 inarg->fh = ff->fh;
142 inarg->flags = flags;
143 req->in.h.opcode = opcode;
144 req->in.h.nodeid = nodeid;
145 req->in.numargs = 1;
146 req->in.args[0].size = sizeof(struct fuse_release_in);
147 req->in.args[0].value = inarg;
148 }
149
150 int fuse_release_common(struct inode *inode, struct file *file, int isdir)
151 {
152 struct fuse_file *ff = file->private_data;
153 if (ff) {
154 struct fuse_conn *fc = get_fuse_conn(inode);
155
156 fuse_release_fill(ff, get_node_id(inode), file->f_flags,
157 isdir ? FUSE_RELEASEDIR : FUSE_RELEASE);
158
159 /* Hold vfsmount and dentry until release is finished */
160 ff->reserved_req->vfsmount = mntget(file->f_path.mnt);
161 ff->reserved_req->dentry = dget(file->f_path.dentry);
162
163 spin_lock(&fc->lock);
164 list_del(&ff->write_entry);
165 spin_unlock(&fc->lock);
166 /*
167 * Normally this will send the RELEASE request,
168 * however if some asynchronous READ or WRITE requests
169 * are outstanding, the sending will be delayed
170 */
171 fuse_file_put(ff);
172 }
173
174 /* Return value is ignored by VFS */
175 return 0;
176 }
177
178 static int fuse_open(struct inode *inode, struct file *file)
179 {
180 return fuse_open_common(inode, file, 0);
181 }
182
183 static int fuse_release(struct inode *inode, struct file *file)
184 {
185 return fuse_release_common(inode, file, 0);
186 }
187
188 /*
189 * Scramble the ID space with XTEA, so that the value of the files_struct
190 * pointer is not exposed to userspace.
191 */
192 static u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id)
193 {
194 u32 *k = fc->scramble_key;
195 u64 v = (unsigned long) id;
196 u32 v0 = v;
197 u32 v1 = v >> 32;
198 u32 sum = 0;
199 int i;
200
201 for (i = 0; i < 32; i++) {
202 v0 += ((v1 << 4 ^ v1 >> 5) + v1) ^ (sum + k[sum & 3]);
203 sum += 0x9E3779B9;
204 v1 += ((v0 << 4 ^ v0 >> 5) + v0) ^ (sum + k[sum>>11 & 3]);
205 }
206
207 return (u64) v0 + ((u64) v1 << 32);
208 }
209
210 static int fuse_flush(struct file *file, fl_owner_t id)
211 {
212 struct inode *inode = file->f_path.dentry->d_inode;
213 struct fuse_conn *fc = get_fuse_conn(inode);
214 struct fuse_file *ff = file->private_data;
215 struct fuse_req *req;
216 struct fuse_flush_in inarg;
217 int err;
218
219 if (is_bad_inode(inode))
220 return -EIO;
221
222 if (fc->no_flush)
223 return 0;
224
225 req = fuse_get_req_nofail(fc, file);
226 memset(&inarg, 0, sizeof(inarg));
227 inarg.fh = ff->fh;
228 inarg.lock_owner = fuse_lock_owner_id(fc, id);
229 req->in.h.opcode = FUSE_FLUSH;
230 req->in.h.nodeid = get_node_id(inode);
231 req->in.numargs = 1;
232 req->in.args[0].size = sizeof(inarg);
233 req->in.args[0].value = &inarg;
234 req->force = 1;
235 request_send(fc, req);
236 err = req->out.h.error;
237 fuse_put_request(fc, req);
238 if (err == -ENOSYS) {
239 fc->no_flush = 1;
240 err = 0;
241 }
242 return err;
243 }
244
245 int fuse_fsync_common(struct file *file, struct dentry *de, int datasync,
246 int isdir)
247 {
248 struct inode *inode = de->d_inode;
249 struct fuse_conn *fc = get_fuse_conn(inode);
250 struct fuse_file *ff = file->private_data;
251 struct fuse_req *req;
252 struct fuse_fsync_in inarg;
253 int err;
254
255 if (is_bad_inode(inode))
256 return -EIO;
257
258 if ((!isdir && fc->no_fsync) || (isdir && fc->no_fsyncdir))
259 return 0;
260
261 req = fuse_get_req(fc);
262 if (IS_ERR(req))
263 return PTR_ERR(req);
264
265 memset(&inarg, 0, sizeof(inarg));
266 inarg.fh = ff->fh;
267 inarg.fsync_flags = datasync ? 1 : 0;
268 req->in.h.opcode = isdir ? FUSE_FSYNCDIR : FUSE_FSYNC;
269 req->in.h.nodeid = get_node_id(inode);
270 req->in.numargs = 1;
271 req->in.args[0].size = sizeof(inarg);
272 req->in.args[0].value = &inarg;
273 request_send(fc, req);
274 err = req->out.h.error;
275 fuse_put_request(fc, req);
276 if (err == -ENOSYS) {
277 if (isdir)
278 fc->no_fsyncdir = 1;
279 else
280 fc->no_fsync = 1;
281 err = 0;
282 }
283 return err;
284 }
285
286 static int fuse_fsync(struct file *file, struct dentry *de, int datasync)
287 {
288 return fuse_fsync_common(file, de, datasync, 0);
289 }
290
291 void fuse_read_fill(struct fuse_req *req, struct fuse_file *ff,
292 struct inode *inode, loff_t pos, size_t count, int opcode)
293 {
294 struct fuse_read_in *inarg = &req->misc.read_in;
295
296 inarg->fh = ff->fh;
297 inarg->offset = pos;
298 inarg->size = count;
299 req->in.h.opcode = opcode;
300 req->in.h.nodeid = get_node_id(inode);
301 req->in.numargs = 1;
302 req->in.args[0].size = sizeof(struct fuse_read_in);
303 req->in.args[0].value = inarg;
304 req->out.argpages = 1;
305 req->out.argvar = 1;
306 req->out.numargs = 1;
307 req->out.args[0].size = count;
308 }
309
310 static size_t fuse_send_read(struct fuse_req *req, struct file *file,
311 struct inode *inode, loff_t pos, size_t count)
312 {
313 struct fuse_conn *fc = get_fuse_conn(inode);
314 struct fuse_file *ff = file->private_data;
315 fuse_read_fill(req, ff, inode, pos, count, FUSE_READ);
316 request_send(fc, req);
317 return req->out.args[0].size;
318 }
319
320 static int fuse_readpage(struct file *file, struct page *page)
321 {
322 struct inode *inode = page->mapping->host;
323 struct fuse_conn *fc = get_fuse_conn(inode);
324 struct fuse_req *req;
325 int err;
326
327 err = -EIO;
328 if (is_bad_inode(inode))
329 goto out;
330
331 req = fuse_get_req(fc);
332 err = PTR_ERR(req);
333 if (IS_ERR(req))
334 goto out;
335
336 req->out.page_zeroing = 1;
337 req->num_pages = 1;
338 req->pages[0] = page;
339 fuse_send_read(req, file, inode, page_offset(page), PAGE_CACHE_SIZE);
340 err = req->out.h.error;
341 fuse_put_request(fc, req);
342 if (!err)
343 SetPageUptodate(page);
344 fuse_invalidate_attr(inode); /* atime changed */
345 out:
346 unlock_page(page);
347 return err;
348 }
349
350 static void fuse_readpages_end(struct fuse_conn *fc, struct fuse_req *req)
351 {
352 int i;
353
354 fuse_invalidate_attr(req->pages[0]->mapping->host); /* atime changed */
355
356 for (i = 0; i < req->num_pages; i++) {
357 struct page *page = req->pages[i];
358 if (!req->out.h.error)
359 SetPageUptodate(page);
360 else
361 SetPageError(page);
362 unlock_page(page);
363 }
364 if (req->ff)
365 fuse_file_put(req->ff);
366 fuse_put_request(fc, req);
367 }
368
369 static void fuse_send_readpages(struct fuse_req *req, struct fuse_file *ff,
370 struct inode *inode)
371 {
372 struct fuse_conn *fc = get_fuse_conn(inode);
373 loff_t pos = page_offset(req->pages[0]);
374 size_t count = req->num_pages << PAGE_CACHE_SHIFT;
375 req->out.page_zeroing = 1;
376 fuse_read_fill(req, ff, inode, pos, count, FUSE_READ);
377 if (fc->async_read) {
378 req->ff = fuse_file_get(ff);
379 req->end = fuse_readpages_end;
380 request_send_background(fc, req);
381 } else {
382 request_send(fc, req);
383 fuse_readpages_end(fc, req);
384 }
385 }
386
387 struct fuse_fill_data {
388 struct fuse_req *req;
389 struct fuse_file *ff;
390 struct inode *inode;
391 };
392
393 static int fuse_readpages_fill(void *_data, struct page *page)
394 {
395 struct fuse_fill_data *data = _data;
396 struct fuse_req *req = data->req;
397 struct inode *inode = data->inode;
398 struct fuse_conn *fc = get_fuse_conn(inode);
399
400 if (req->num_pages &&
401 (req->num_pages == FUSE_MAX_PAGES_PER_REQ ||
402 (req->num_pages + 1) * PAGE_CACHE_SIZE > fc->max_read ||
403 req->pages[req->num_pages - 1]->index + 1 != page->index)) {
404 fuse_send_readpages(req, data->ff, inode);
405 data->req = req = fuse_get_req(fc);
406 if (IS_ERR(req)) {
407 unlock_page(page);
408 return PTR_ERR(req);
409 }
410 }
411 req->pages[req->num_pages] = page;
412 req->num_pages ++;
413 return 0;
414 }
415
416 static int fuse_readpages(struct file *file, struct address_space *mapping,
417 struct list_head *pages, unsigned nr_pages)
418 {
419 struct inode *inode = mapping->host;
420 struct fuse_conn *fc = get_fuse_conn(inode);
421 struct fuse_fill_data data;
422 int err;
423
424 err = -EIO;
425 if (is_bad_inode(inode))
426 goto out;
427
428 data.ff = file->private_data;
429 data.inode = inode;
430 data.req = fuse_get_req(fc);
431 err = PTR_ERR(data.req);
432 if (IS_ERR(data.req))
433 goto out;
434
435 err = read_cache_pages(mapping, pages, fuse_readpages_fill, &data);
436 if (!err) {
437 if (data.req->num_pages)
438 fuse_send_readpages(data.req, data.ff, inode);
439 else
440 fuse_put_request(fc, data.req);
441 }
442 out:
443 return err;
444 }
445
446 static void fuse_write_fill(struct fuse_req *req, struct fuse_file *ff,
447 struct inode *inode, loff_t pos, size_t count,
448 int writepage)
449 {
450 struct fuse_write_in *inarg = &req->misc.write.in;
451 struct fuse_write_out *outarg = &req->misc.write.out;
452
453 memset(inarg, 0, sizeof(struct fuse_write_in));
454 inarg->fh = ff->fh;
455 inarg->offset = pos;
456 inarg->size = count;
457 inarg->write_flags = writepage ? FUSE_WRITE_CACHE : 0;
458 req->in.h.opcode = FUSE_WRITE;
459 req->in.h.nodeid = get_node_id(inode);
460 req->in.argpages = 1;
461 req->in.numargs = 2;
462 req->in.args[0].size = sizeof(struct fuse_write_in);
463 req->in.args[0].value = inarg;
464 req->in.args[1].size = count;
465 req->out.numargs = 1;
466 req->out.args[0].size = sizeof(struct fuse_write_out);
467 req->out.args[0].value = outarg;
468 }
469
470 static size_t fuse_send_write(struct fuse_req *req, struct file *file,
471 struct inode *inode, loff_t pos, size_t count)
472 {
473 struct fuse_conn *fc = get_fuse_conn(inode);
474 fuse_write_fill(req, file->private_data, inode, pos, count, 0);
475 request_send(fc, req);
476 return req->misc.write.out.size;
477 }
478
479 static int fuse_write_begin(struct file *file, struct address_space *mapping,
480 loff_t pos, unsigned len, unsigned flags,
481 struct page **pagep, void **fsdata)
482 {
483 pgoff_t index = pos >> PAGE_CACHE_SHIFT;
484
485 *pagep = __grab_cache_page(mapping, index);
486 if (!*pagep)
487 return -ENOMEM;
488 return 0;
489 }
490
491 static int fuse_buffered_write(struct file *file, struct inode *inode,
492 loff_t pos, unsigned count, struct page *page)
493 {
494 int err;
495 size_t nres;
496 struct fuse_conn *fc = get_fuse_conn(inode);
497 struct fuse_inode *fi = get_fuse_inode(inode);
498 unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
499 struct fuse_req *req;
500
501 if (is_bad_inode(inode))
502 return -EIO;
503
504 req = fuse_get_req(fc);
505 if (IS_ERR(req))
506 return PTR_ERR(req);
507
508 req->num_pages = 1;
509 req->pages[0] = page;
510 req->page_offset = offset;
511 nres = fuse_send_write(req, file, inode, pos, count);
512 err = req->out.h.error;
513 fuse_put_request(fc, req);
514 if (!err && !nres)
515 err = -EIO;
516 if (!err) {
517 pos += nres;
518 spin_lock(&fc->lock);
519 fi->attr_version = ++fc->attr_version;
520 if (pos > inode->i_size)
521 i_size_write(inode, pos);
522 spin_unlock(&fc->lock);
523
524 if (count == PAGE_CACHE_SIZE)
525 SetPageUptodate(page);
526 }
527 fuse_invalidate_attr(inode);
528 return err ? err : nres;
529 }
530
531 static int fuse_write_end(struct file *file, struct address_space *mapping,
532 loff_t pos, unsigned len, unsigned copied,
533 struct page *page, void *fsdata)
534 {
535 struct inode *inode = mapping->host;
536 int res = 0;
537
538 if (copied)
539 res = fuse_buffered_write(file, inode, pos, copied, page);
540
541 unlock_page(page);
542 page_cache_release(page);
543 return res;
544 }
545
546 static void fuse_release_user_pages(struct fuse_req *req, int write)
547 {
548 unsigned i;
549
550 for (i = 0; i < req->num_pages; i++) {
551 struct page *page = req->pages[i];
552 if (write)
553 set_page_dirty_lock(page);
554 put_page(page);
555 }
556 }
557
558 static int fuse_get_user_pages(struct fuse_req *req, const char __user *buf,
559 unsigned nbytes, int write)
560 {
561 unsigned long user_addr = (unsigned long) buf;
562 unsigned offset = user_addr & ~PAGE_MASK;
563 int npages;
564
565 /* This doesn't work with nfsd */
566 if (!current->mm)
567 return -EPERM;
568
569 nbytes = min(nbytes, (unsigned) FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT);
570 npages = (nbytes + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
571 npages = min(max(npages, 1), FUSE_MAX_PAGES_PER_REQ);
572 down_read(&current->mm->mmap_sem);
573 npages = get_user_pages(current, current->mm, user_addr, npages, write,
574 0, req->pages, NULL);
575 up_read(&current->mm->mmap_sem);
576 if (npages < 0)
577 return npages;
578
579 req->num_pages = npages;
580 req->page_offset = offset;
581 return 0;
582 }
583
584 static ssize_t fuse_direct_io(struct file *file, const char __user *buf,
585 size_t count, loff_t *ppos, int write)
586 {
587 struct inode *inode = file->f_path.dentry->d_inode;
588 struct fuse_conn *fc = get_fuse_conn(inode);
589 size_t nmax = write ? fc->max_write : fc->max_read;
590 loff_t pos = *ppos;
591 ssize_t res = 0;
592 struct fuse_req *req;
593
594 if (is_bad_inode(inode))
595 return -EIO;
596
597 req = fuse_get_req(fc);
598 if (IS_ERR(req))
599 return PTR_ERR(req);
600
601 while (count) {
602 size_t nres;
603 size_t nbytes = min(count, nmax);
604 int err = fuse_get_user_pages(req, buf, nbytes, !write);
605 if (err) {
606 res = err;
607 break;
608 }
609 nbytes = (req->num_pages << PAGE_SHIFT) - req->page_offset;
610 nbytes = min(count, nbytes);
611 if (write)
612 nres = fuse_send_write(req, file, inode, pos, nbytes);
613 else
614 nres = fuse_send_read(req, file, inode, pos, nbytes);
615 fuse_release_user_pages(req, !write);
616 if (req->out.h.error) {
617 if (!res)
618 res = req->out.h.error;
619 break;
620 } else if (nres > nbytes) {
621 res = -EIO;
622 break;
623 }
624 count -= nres;
625 res += nres;
626 pos += nres;
627 buf += nres;
628 if (nres != nbytes)
629 break;
630 if (count) {
631 fuse_put_request(fc, req);
632 req = fuse_get_req(fc);
633 if (IS_ERR(req))
634 break;
635 }
636 }
637 fuse_put_request(fc, req);
638 if (res > 0) {
639 if (write) {
640 spin_lock(&fc->lock);
641 if (pos > inode->i_size)
642 i_size_write(inode, pos);
643 spin_unlock(&fc->lock);
644 }
645 *ppos = pos;
646 }
647 fuse_invalidate_attr(inode);
648
649 return res;
650 }
651
652 static ssize_t fuse_direct_read(struct file *file, char __user *buf,
653 size_t count, loff_t *ppos)
654 {
655 return fuse_direct_io(file, buf, count, ppos, 0);
656 }
657
658 static ssize_t fuse_direct_write(struct file *file, const char __user *buf,
659 size_t count, loff_t *ppos)
660 {
661 struct inode *inode = file->f_path.dentry->d_inode;
662 ssize_t res;
663 /* Don't allow parallel writes to the same file */
664 mutex_lock(&inode->i_mutex);
665 res = generic_write_checks(file, ppos, &count, 0);
666 if (!res)
667 res = fuse_direct_io(file, buf, count, ppos, 1);
668 mutex_unlock(&inode->i_mutex);
669 return res;
670 }
671
672 static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma)
673 {
674 if ((vma->vm_flags & VM_SHARED)) {
675 if ((vma->vm_flags & VM_WRITE))
676 return -ENODEV;
677 else
678 vma->vm_flags &= ~VM_MAYWRITE;
679 }
680 return generic_file_mmap(file, vma);
681 }
682
683 static int fuse_set_page_dirty(struct page *page)
684 {
685 printk("fuse_set_page_dirty: should not happen\n");
686 dump_stack();
687 return 0;
688 }
689
690 static int convert_fuse_file_lock(const struct fuse_file_lock *ffl,
691 struct file_lock *fl)
692 {
693 switch (ffl->type) {
694 case F_UNLCK:
695 break;
696
697 case F_RDLCK:
698 case F_WRLCK:
699 if (ffl->start > OFFSET_MAX || ffl->end > OFFSET_MAX ||
700 ffl->end < ffl->start)
701 return -EIO;
702
703 fl->fl_start = ffl->start;
704 fl->fl_end = ffl->end;
705 fl->fl_pid = ffl->pid;
706 break;
707
708 default:
709 return -EIO;
710 }
711 fl->fl_type = ffl->type;
712 return 0;
713 }
714
715 static void fuse_lk_fill(struct fuse_req *req, struct file *file,
716 const struct file_lock *fl, int opcode, pid_t pid,
717 int flock)
718 {
719 struct inode *inode = file->f_path.dentry->d_inode;
720 struct fuse_conn *fc = get_fuse_conn(inode);
721 struct fuse_file *ff = file->private_data;
722 struct fuse_lk_in *arg = &req->misc.lk_in;
723
724 arg->fh = ff->fh;
725 arg->owner = fuse_lock_owner_id(fc, fl->fl_owner);
726 arg->lk.start = fl->fl_start;
727 arg->lk.end = fl->fl_end;
728 arg->lk.type = fl->fl_type;
729 arg->lk.pid = pid;
730 if (flock)
731 arg->lk_flags |= FUSE_LK_FLOCK;
732 req->in.h.opcode = opcode;
733 req->in.h.nodeid = get_node_id(inode);
734 req->in.numargs = 1;
735 req->in.args[0].size = sizeof(*arg);
736 req->in.args[0].value = arg;
737 }
738
739 static int fuse_getlk(struct file *file, struct file_lock *fl)
740 {
741 struct inode *inode = file->f_path.dentry->d_inode;
742 struct fuse_conn *fc = get_fuse_conn(inode);
743 struct fuse_req *req;
744 struct fuse_lk_out outarg;
745 int err;
746
747 req = fuse_get_req(fc);
748 if (IS_ERR(req))
749 return PTR_ERR(req);
750
751 fuse_lk_fill(req, file, fl, FUSE_GETLK, 0, 0);
752 req->out.numargs = 1;
753 req->out.args[0].size = sizeof(outarg);
754 req->out.args[0].value = &outarg;
755 request_send(fc, req);
756 err = req->out.h.error;
757 fuse_put_request(fc, req);
758 if (!err)
759 err = convert_fuse_file_lock(&outarg.lk, fl);
760
761 return err;
762 }
763
764 static int fuse_setlk(struct file *file, struct file_lock *fl, int flock)
765 {
766 struct inode *inode = file->f_path.dentry->d_inode;
767 struct fuse_conn *fc = get_fuse_conn(inode);
768 struct fuse_req *req;
769 int opcode = (fl->fl_flags & FL_SLEEP) ? FUSE_SETLKW : FUSE_SETLK;
770 pid_t pid = fl->fl_type != F_UNLCK ? current->tgid : 0;
771 int err;
772
773 /* Unlock on close is handled by the flush method */
774 if (fl->fl_flags & FL_CLOSE)
775 return 0;
776
777 req = fuse_get_req(fc);
778 if (IS_ERR(req))
779 return PTR_ERR(req);
780
781 fuse_lk_fill(req, file, fl, opcode, pid, flock);
782 request_send(fc, req);
783 err = req->out.h.error;
784 /* locking is restartable */
785 if (err == -EINTR)
786 err = -ERESTARTSYS;
787 fuse_put_request(fc, req);
788 return err;
789 }
790
791 static int fuse_file_lock(struct file *file, int cmd, struct file_lock *fl)
792 {
793 struct inode *inode = file->f_path.dentry->d_inode;
794 struct fuse_conn *fc = get_fuse_conn(inode);
795 int err;
796
797 if (cmd == F_GETLK) {
798 if (fc->no_lock) {
799 posix_test_lock(file, fl);
800 err = 0;
801 } else
802 err = fuse_getlk(file, fl);
803 } else {
804 if (fc->no_lock)
805 err = posix_lock_file_wait(file, fl);
806 else
807 err = fuse_setlk(file, fl, 0);
808 }
809 return err;
810 }
811
812 static int fuse_file_flock(struct file *file, int cmd, struct file_lock *fl)
813 {
814 struct inode *inode = file->f_path.dentry->d_inode;
815 struct fuse_conn *fc = get_fuse_conn(inode);
816 int err;
817
818 if (fc->no_lock) {
819 err = flock_lock_file_wait(file, fl);
820 } else {
821 /* emulate flock with POSIX locks */
822 fl->fl_owner = (fl_owner_t) file;
823 err = fuse_setlk(file, fl, 1);
824 }
825
826 return err;
827 }
828
829 static sector_t fuse_bmap(struct address_space *mapping, sector_t block)
830 {
831 struct inode *inode = mapping->host;
832 struct fuse_conn *fc = get_fuse_conn(inode);
833 struct fuse_req *req;
834 struct fuse_bmap_in inarg;
835 struct fuse_bmap_out outarg;
836 int err;
837
838 if (!inode->i_sb->s_bdev || fc->no_bmap)
839 return 0;
840
841 req = fuse_get_req(fc);
842 if (IS_ERR(req))
843 return 0;
844
845 memset(&inarg, 0, sizeof(inarg));
846 inarg.block = block;
847 inarg.blocksize = inode->i_sb->s_blocksize;
848 req->in.h.opcode = FUSE_BMAP;
849 req->in.h.nodeid = get_node_id(inode);
850 req->in.numargs = 1;
851 req->in.args[0].size = sizeof(inarg);
852 req->in.args[0].value = &inarg;
853 req->out.numargs = 1;
854 req->out.args[0].size = sizeof(outarg);
855 req->out.args[0].value = &outarg;
856 request_send(fc, req);
857 err = req->out.h.error;
858 fuse_put_request(fc, req);
859 if (err == -ENOSYS)
860 fc->no_bmap = 1;
861
862 return err ? 0 : outarg.block;
863 }
864
865 static const struct file_operations fuse_file_operations = {
866 .llseek = generic_file_llseek,
867 .read = do_sync_read,
868 .aio_read = generic_file_aio_read,
869 .write = do_sync_write,
870 .aio_write = generic_file_aio_write,
871 .mmap = fuse_file_mmap,
872 .open = fuse_open,
873 .flush = fuse_flush,
874 .release = fuse_release,
875 .fsync = fuse_fsync,
876 .lock = fuse_file_lock,
877 .flock = fuse_file_flock,
878 .splice_read = generic_file_splice_read,
879 };
880
881 static const struct file_operations fuse_direct_io_file_operations = {
882 .llseek = generic_file_llseek,
883 .read = fuse_direct_read,
884 .write = fuse_direct_write,
885 .open = fuse_open,
886 .flush = fuse_flush,
887 .release = fuse_release,
888 .fsync = fuse_fsync,
889 .lock = fuse_file_lock,
890 .flock = fuse_file_flock,
891 /* no mmap and splice_read */
892 };
893
894 static const struct address_space_operations fuse_file_aops = {
895 .readpage = fuse_readpage,
896 .write_begin = fuse_write_begin,
897 .write_end = fuse_write_end,
898 .readpages = fuse_readpages,
899 .set_page_dirty = fuse_set_page_dirty,
900 .bmap = fuse_bmap,
901 };
902
903 void fuse_init_file_inode(struct inode *inode)
904 {
905 inode->i_fop = &fuse_file_operations;
906 inode->i_data.a_ops = &fuse_file_aops;
907 }
WandBoard kernel