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fuse: fix flock
[deliverable/linux.git] / fs / fuse / file.c
1 /*
2 FUSE: Filesystem in Userspace
3 Copyright (C) 2001-2008 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 #include <linux/module.h>
16 #include <linux/compat.h>
17
18 static const struct file_operations fuse_direct_io_file_operations;
19
20 static int fuse_send_open(struct fuse_conn *fc, u64 nodeid, struct file *file,
21 int opcode, struct fuse_open_out *outargp)
22 {
23 struct fuse_open_in inarg;
24 struct fuse_req *req;
25 int err;
26
27 req = fuse_get_req(fc);
28 if (IS_ERR(req))
29 return PTR_ERR(req);
30
31 memset(&inarg, 0, sizeof(inarg));
32 inarg.flags = file->f_flags & ~(O_CREAT | O_EXCL | O_NOCTTY);
33 if (!fc->atomic_o_trunc)
34 inarg.flags &= ~O_TRUNC;
35 req->in.h.opcode = opcode;
36 req->in.h.nodeid = nodeid;
37 req->in.numargs = 1;
38 req->in.args[0].size = sizeof(inarg);
39 req->in.args[0].value = &inarg;
40 req->out.numargs = 1;
41 req->out.args[0].size = sizeof(*outargp);
42 req->out.args[0].value = outargp;
43 fuse_request_send(fc, req);
44 err = req->out.h.error;
45 fuse_put_request(fc, req);
46
47 return err;
48 }
49
50 struct fuse_file *fuse_file_alloc(struct fuse_conn *fc)
51 {
52 struct fuse_file *ff;
53
54 ff = kmalloc(sizeof(struct fuse_file), GFP_KERNEL);
55 if (unlikely(!ff))
56 return NULL;
57
58 ff->fc = fc;
59 ff->reserved_req = fuse_request_alloc();
60 if (unlikely(!ff->reserved_req)) {
61 kfree(ff);
62 return NULL;
63 }
64
65 INIT_LIST_HEAD(&ff->write_entry);
66 atomic_set(&ff->count, 0);
67 RB_CLEAR_NODE(&ff->polled_node);
68 init_waitqueue_head(&ff->poll_wait);
69
70 spin_lock(&fc->lock);
71 ff->kh = ++fc->khctr;
72 spin_unlock(&fc->lock);
73
74 return ff;
75 }
76
77 void fuse_file_free(struct fuse_file *ff)
78 {
79 fuse_request_free(ff->reserved_req);
80 kfree(ff);
81 }
82
83 struct fuse_file *fuse_file_get(struct fuse_file *ff)
84 {
85 atomic_inc(&ff->count);
86 return ff;
87 }
88
89 static void fuse_release_async(struct work_struct *work)
90 {
91 struct fuse_req *req;
92 struct fuse_conn *fc;
93 struct path path;
94
95 req = container_of(work, struct fuse_req, misc.release.work);
96 path = req->misc.release.path;
97 fc = get_fuse_conn(path.dentry->d_inode);
98
99 fuse_put_request(fc, req);
100 path_put(&path);
101 }
102
103 static void fuse_release_end(struct fuse_conn *fc, struct fuse_req *req)
104 {
105 if (fc->destroy_req) {
106 /*
107 * If this is a fuseblk mount, then it's possible that
108 * releasing the path will result in releasing the
109 * super block and sending the DESTROY request. If
110 * the server is single threaded, this would hang.
111 * For this reason do the path_put() in a separate
112 * thread.
113 */
114 atomic_inc(&req->count);
115 INIT_WORK(&req->misc.release.work, fuse_release_async);
116 schedule_work(&req->misc.release.work);
117 } else {
118 path_put(&req->misc.release.path);
119 }
120 }
121
122 static void fuse_file_put(struct fuse_file *ff, bool sync)
123 {
124 if (atomic_dec_and_test(&ff->count)) {
125 struct fuse_req *req = ff->reserved_req;
126
127 if (sync) {
128 fuse_request_send(ff->fc, req);
129 path_put(&req->misc.release.path);
130 fuse_put_request(ff->fc, req);
131 } else {
132 req->end = fuse_release_end;
133 fuse_request_send_background(ff->fc, req);
134 }
135 kfree(ff);
136 }
137 }
138
139 int fuse_do_open(struct fuse_conn *fc, u64 nodeid, struct file *file,
140 bool isdir)
141 {
142 struct fuse_open_out outarg;
143 struct fuse_file *ff;
144 int err;
145 int opcode = isdir ? FUSE_OPENDIR : FUSE_OPEN;
146
147 ff = fuse_file_alloc(fc);
148 if (!ff)
149 return -ENOMEM;
150
151 err = fuse_send_open(fc, nodeid, file, opcode, &outarg);
152 if (err) {
153 fuse_file_free(ff);
154 return err;
155 }
156
157 if (isdir)
158 outarg.open_flags &= ~FOPEN_DIRECT_IO;
159
160 ff->fh = outarg.fh;
161 ff->nodeid = nodeid;
162 ff->open_flags = outarg.open_flags;
163 file->private_data = fuse_file_get(ff);
164
165 return 0;
166 }
167 EXPORT_SYMBOL_GPL(fuse_do_open);
168
169 void fuse_finish_open(struct inode *inode, struct file *file)
170 {
171 struct fuse_file *ff = file->private_data;
172 struct fuse_conn *fc = get_fuse_conn(inode);
173
174 if (ff->open_flags & FOPEN_DIRECT_IO)
175 file->f_op = &fuse_direct_io_file_operations;
176 if (!(ff->open_flags & FOPEN_KEEP_CACHE))
177 invalidate_inode_pages2(inode->i_mapping);
178 if (ff->open_flags & FOPEN_NONSEEKABLE)
179 nonseekable_open(inode, file);
180 if (fc->atomic_o_trunc && (file->f_flags & O_TRUNC)) {
181 struct fuse_inode *fi = get_fuse_inode(inode);
182
183 spin_lock(&fc->lock);
184 fi->attr_version = ++fc->attr_version;
185 i_size_write(inode, 0);
186 spin_unlock(&fc->lock);
187 fuse_invalidate_attr(inode);
188 }
189 }
190
191 int fuse_open_common(struct inode *inode, struct file *file, bool isdir)
192 {
193 struct fuse_conn *fc = get_fuse_conn(inode);
194 int err;
195
196 /* VFS checks this, but only _after_ ->open() */
197 if (file->f_flags & O_DIRECT)
198 return -EINVAL;
199
200 err = generic_file_open(inode, file);
201 if (err)
202 return err;
203
204 err = fuse_do_open(fc, get_node_id(inode), file, isdir);
205 if (err)
206 return err;
207
208 fuse_finish_open(inode, file);
209
210 return 0;
211 }
212
213 static void fuse_prepare_release(struct fuse_file *ff, int flags, int opcode)
214 {
215 struct fuse_conn *fc = ff->fc;
216 struct fuse_req *req = ff->reserved_req;
217 struct fuse_release_in *inarg = &req->misc.release.in;
218
219 spin_lock(&fc->lock);
220 list_del(&ff->write_entry);
221 if (!RB_EMPTY_NODE(&ff->polled_node))
222 rb_erase(&ff->polled_node, &fc->polled_files);
223 spin_unlock(&fc->lock);
224
225 wake_up_interruptible_all(&ff->poll_wait);
226
227 inarg->fh = ff->fh;
228 inarg->flags = flags;
229 req->in.h.opcode = opcode;
230 req->in.h.nodeid = ff->nodeid;
231 req->in.numargs = 1;
232 req->in.args[0].size = sizeof(struct fuse_release_in);
233 req->in.args[0].value = inarg;
234 }
235
236 void fuse_release_common(struct file *file, int opcode)
237 {
238 struct fuse_file *ff;
239 struct fuse_req *req;
240
241 ff = file->private_data;
242 if (unlikely(!ff))
243 return;
244
245 req = ff->reserved_req;
246 fuse_prepare_release(ff, file->f_flags, opcode);
247
248 if (ff->flock) {
249 struct fuse_release_in *inarg = &req->misc.release.in;
250 inarg->release_flags |= FUSE_RELEASE_FLOCK_UNLOCK;
251 inarg->lock_owner = fuse_lock_owner_id(ff->fc,
252 (fl_owner_t) file);
253 }
254 /* Hold vfsmount and dentry until release is finished */
255 path_get(&file->f_path);
256 req->misc.release.path = file->f_path;
257
258 /*
259 * Normally this will send the RELEASE request, however if
260 * some asynchronous READ or WRITE requests are outstanding,
261 * the sending will be delayed.
262 *
263 * Make the release synchronous if this is a fuseblk mount,
264 * synchronous RELEASE is allowed (and desirable) in this case
265 * because the server can be trusted not to screw up.
266 */
267 fuse_file_put(ff, ff->fc->destroy_req != NULL);
268 }
269
270 static int fuse_open(struct inode *inode, struct file *file)
271 {
272 return fuse_open_common(inode, file, false);
273 }
274
275 static int fuse_release(struct inode *inode, struct file *file)
276 {
277 fuse_release_common(file, FUSE_RELEASE);
278
279 /* return value is ignored by VFS */
280 return 0;
281 }
282
283 void fuse_sync_release(struct fuse_file *ff, int flags)
284 {
285 WARN_ON(atomic_read(&ff->count) > 1);
286 fuse_prepare_release(ff, flags, FUSE_RELEASE);
287 ff->reserved_req->force = 1;
288 fuse_request_send(ff->fc, ff->reserved_req);
289 fuse_put_request(ff->fc, ff->reserved_req);
290 kfree(ff);
291 }
292 EXPORT_SYMBOL_GPL(fuse_sync_release);
293
294 /*
295 * Scramble the ID space with XTEA, so that the value of the files_struct
296 * pointer is not exposed to userspace.
297 */
298 u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id)
299 {
300 u32 *k = fc->scramble_key;
301 u64 v = (unsigned long) id;
302 u32 v0 = v;
303 u32 v1 = v >> 32;
304 u32 sum = 0;
305 int i;
306
307 for (i = 0; i < 32; i++) {
308 v0 += ((v1 << 4 ^ v1 >> 5) + v1) ^ (sum + k[sum & 3]);
309 sum += 0x9E3779B9;
310 v1 += ((v0 << 4 ^ v0 >> 5) + v0) ^ (sum + k[sum>>11 & 3]);
311 }
312
313 return (u64) v0 + ((u64) v1 << 32);
314 }
315
316 /*
317 * Check if page is under writeback
318 *
319 * This is currently done by walking the list of writepage requests
320 * for the inode, which can be pretty inefficient.
321 */
322 static bool fuse_page_is_writeback(struct inode *inode, pgoff_t index)
323 {
324 struct fuse_conn *fc = get_fuse_conn(inode);
325 struct fuse_inode *fi = get_fuse_inode(inode);
326 struct fuse_req *req;
327 bool found = false;
328
329 spin_lock(&fc->lock);
330 list_for_each_entry(req, &fi->writepages, writepages_entry) {
331 pgoff_t curr_index;
332
333 BUG_ON(req->inode != inode);
334 curr_index = req->misc.write.in.offset >> PAGE_CACHE_SHIFT;
335 if (curr_index == index) {
336 found = true;
337 break;
338 }
339 }
340 spin_unlock(&fc->lock);
341
342 return found;
343 }
344
345 /*
346 * Wait for page writeback to be completed.
347 *
348 * Since fuse doesn't rely on the VM writeback tracking, this has to
349 * use some other means.
350 */
351 static int fuse_wait_on_page_writeback(struct inode *inode, pgoff_t index)
352 {
353 struct fuse_inode *fi = get_fuse_inode(inode);
354
355 wait_event(fi->page_waitq, !fuse_page_is_writeback(inode, index));
356 return 0;
357 }
358
359 static int fuse_flush(struct file *file, fl_owner_t id)
360 {
361 struct inode *inode = file->f_path.dentry->d_inode;
362 struct fuse_conn *fc = get_fuse_conn(inode);
363 struct fuse_file *ff = file->private_data;
364 struct fuse_req *req;
365 struct fuse_flush_in inarg;
366 int err;
367
368 if (is_bad_inode(inode))
369 return -EIO;
370
371 if (fc->no_flush)
372 return 0;
373
374 req = fuse_get_req_nofail(fc, file);
375 memset(&inarg, 0, sizeof(inarg));
376 inarg.fh = ff->fh;
377 inarg.lock_owner = fuse_lock_owner_id(fc, id);
378 req->in.h.opcode = FUSE_FLUSH;
379 req->in.h.nodeid = get_node_id(inode);
380 req->in.numargs = 1;
381 req->in.args[0].size = sizeof(inarg);
382 req->in.args[0].value = &inarg;
383 req->force = 1;
384 fuse_request_send(fc, req);
385 err = req->out.h.error;
386 fuse_put_request(fc, req);
387 if (err == -ENOSYS) {
388 fc->no_flush = 1;
389 err = 0;
390 }
391 return err;
392 }
393
394 /*
395 * Wait for all pending writepages on the inode to finish.
396 *
397 * This is currently done by blocking further writes with FUSE_NOWRITE
398 * and waiting for all sent writes to complete.
399 *
400 * This must be called under i_mutex, otherwise the FUSE_NOWRITE usage
401 * could conflict with truncation.
402 */
403 static void fuse_sync_writes(struct inode *inode)
404 {
405 fuse_set_nowrite(inode);
406 fuse_release_nowrite(inode);
407 }
408
409 int fuse_fsync_common(struct file *file, int datasync, int isdir)
410 {
411 struct inode *inode = file->f_mapping->host;
412 struct fuse_conn *fc = get_fuse_conn(inode);
413 struct fuse_file *ff = file->private_data;
414 struct fuse_req *req;
415 struct fuse_fsync_in inarg;
416 int err;
417
418 if (is_bad_inode(inode))
419 return -EIO;
420
421 if ((!isdir && fc->no_fsync) || (isdir && fc->no_fsyncdir))
422 return 0;
423
424 /*
425 * Start writeback against all dirty pages of the inode, then
426 * wait for all outstanding writes, before sending the FSYNC
427 * request.
428 */
429 err = write_inode_now(inode, 0);
430 if (err)
431 return err;
432
433 fuse_sync_writes(inode);
434
435 req = fuse_get_req(fc);
436 if (IS_ERR(req))
437 return PTR_ERR(req);
438
439 memset(&inarg, 0, sizeof(inarg));
440 inarg.fh = ff->fh;
441 inarg.fsync_flags = datasync ? 1 : 0;
442 req->in.h.opcode = isdir ? FUSE_FSYNCDIR : FUSE_FSYNC;
443 req->in.h.nodeid = get_node_id(inode);
444 req->in.numargs = 1;
445 req->in.args[0].size = sizeof(inarg);
446 req->in.args[0].value = &inarg;
447 fuse_request_send(fc, req);
448 err = req->out.h.error;
449 fuse_put_request(fc, req);
450 if (err == -ENOSYS) {
451 if (isdir)
452 fc->no_fsyncdir = 1;
453 else
454 fc->no_fsync = 1;
455 err = 0;
456 }
457 return err;
458 }
459
460 static int fuse_fsync(struct file *file, int datasync)
461 {
462 return fuse_fsync_common(file, datasync, 0);
463 }
464
465 void fuse_read_fill(struct fuse_req *req, struct file *file, loff_t pos,
466 size_t count, int opcode)
467 {
468 struct fuse_read_in *inarg = &req->misc.read.in;
469 struct fuse_file *ff = file->private_data;
470
471 inarg->fh = ff->fh;
472 inarg->offset = pos;
473 inarg->size = count;
474 inarg->flags = file->f_flags;
475 req->in.h.opcode = opcode;
476 req->in.h.nodeid = ff->nodeid;
477 req->in.numargs = 1;
478 req->in.args[0].size = sizeof(struct fuse_read_in);
479 req->in.args[0].value = inarg;
480 req->out.argvar = 1;
481 req->out.numargs = 1;
482 req->out.args[0].size = count;
483 }
484
485 static size_t fuse_send_read(struct fuse_req *req, struct file *file,
486 loff_t pos, size_t count, fl_owner_t owner)
487 {
488 struct fuse_file *ff = file->private_data;
489 struct fuse_conn *fc = ff->fc;
490
491 fuse_read_fill(req, file, pos, count, FUSE_READ);
492 if (owner != NULL) {
493 struct fuse_read_in *inarg = &req->misc.read.in;
494
495 inarg->read_flags |= FUSE_READ_LOCKOWNER;
496 inarg->lock_owner = fuse_lock_owner_id(fc, owner);
497 }
498 fuse_request_send(fc, req);
499 return req->out.args[0].size;
500 }
501
502 static void fuse_read_update_size(struct inode *inode, loff_t size,
503 u64 attr_ver)
504 {
505 struct fuse_conn *fc = get_fuse_conn(inode);
506 struct fuse_inode *fi = get_fuse_inode(inode);
507
508 spin_lock(&fc->lock);
509 if (attr_ver == fi->attr_version && size < inode->i_size) {
510 fi->attr_version = ++fc->attr_version;
511 i_size_write(inode, size);
512 }
513 spin_unlock(&fc->lock);
514 }
515
516 static int fuse_readpage(struct file *file, struct page *page)
517 {
518 struct inode *inode = page->mapping->host;
519 struct fuse_conn *fc = get_fuse_conn(inode);
520 struct fuse_req *req;
521 size_t num_read;
522 loff_t pos = page_offset(page);
523 size_t count = PAGE_CACHE_SIZE;
524 u64 attr_ver;
525 int err;
526
527 err = -EIO;
528 if (is_bad_inode(inode))
529 goto out;
530
531 /*
532 * Page writeback can extend beyond the lifetime of the
533 * page-cache page, so make sure we read a properly synced
534 * page.
535 */
536 fuse_wait_on_page_writeback(inode, page->index);
537
538 req = fuse_get_req(fc);
539 err = PTR_ERR(req);
540 if (IS_ERR(req))
541 goto out;
542
543 attr_ver = fuse_get_attr_version(fc);
544
545 req->out.page_zeroing = 1;
546 req->out.argpages = 1;
547 req->num_pages = 1;
548 req->pages[0] = page;
549 num_read = fuse_send_read(req, file, pos, count, NULL);
550 err = req->out.h.error;
551 fuse_put_request(fc, req);
552
553 if (!err) {
554 /*
555 * Short read means EOF. If file size is larger, truncate it
556 */
557 if (num_read < count)
558 fuse_read_update_size(inode, pos + num_read, attr_ver);
559
560 SetPageUptodate(page);
561 }
562
563 fuse_invalidate_attr(inode); /* atime changed */
564 out:
565 unlock_page(page);
566 return err;
567 }
568
569 static void fuse_readpages_end(struct fuse_conn *fc, struct fuse_req *req)
570 {
571 int i;
572 size_t count = req->misc.read.in.size;
573 size_t num_read = req->out.args[0].size;
574 struct address_space *mapping = NULL;
575
576 for (i = 0; mapping == NULL && i < req->num_pages; i++)
577 mapping = req->pages[i]->mapping;
578
579 if (mapping) {
580 struct inode *inode = mapping->host;
581
582 /*
583 * Short read means EOF. If file size is larger, truncate it
584 */
585 if (!req->out.h.error && num_read < count) {
586 loff_t pos;
587
588 pos = page_offset(req->pages[0]) + num_read;
589 fuse_read_update_size(inode, pos,
590 req->misc.read.attr_ver);
591 }
592 fuse_invalidate_attr(inode); /* atime changed */
593 }
594
595 for (i = 0; i < req->num_pages; i++) {
596 struct page *page = req->pages[i];
597 if (!req->out.h.error)
598 SetPageUptodate(page);
599 else
600 SetPageError(page);
601 unlock_page(page);
602 page_cache_release(page);
603 }
604 if (req->ff)
605 fuse_file_put(req->ff, false);
606 }
607
608 static void fuse_send_readpages(struct fuse_req *req, struct file *file)
609 {
610 struct fuse_file *ff = file->private_data;
611 struct fuse_conn *fc = ff->fc;
612 loff_t pos = page_offset(req->pages[0]);
613 size_t count = req->num_pages << PAGE_CACHE_SHIFT;
614
615 req->out.argpages = 1;
616 req->out.page_zeroing = 1;
617 req->out.page_replace = 1;
618 fuse_read_fill(req, file, pos, count, FUSE_READ);
619 req->misc.read.attr_ver = fuse_get_attr_version(fc);
620 if (fc->async_read) {
621 req->ff = fuse_file_get(ff);
622 req->end = fuse_readpages_end;
623 fuse_request_send_background(fc, req);
624 } else {
625 fuse_request_send(fc, req);
626 fuse_readpages_end(fc, req);
627 fuse_put_request(fc, req);
628 }
629 }
630
631 struct fuse_fill_data {
632 struct fuse_req *req;
633 struct file *file;
634 struct inode *inode;
635 };
636
637 static int fuse_readpages_fill(void *_data, struct page *page)
638 {
639 struct fuse_fill_data *data = _data;
640 struct fuse_req *req = data->req;
641 struct inode *inode = data->inode;
642 struct fuse_conn *fc = get_fuse_conn(inode);
643
644 fuse_wait_on_page_writeback(inode, page->index);
645
646 if (req->num_pages &&
647 (req->num_pages == FUSE_MAX_PAGES_PER_REQ ||
648 (req->num_pages + 1) * PAGE_CACHE_SIZE > fc->max_read ||
649 req->pages[req->num_pages - 1]->index + 1 != page->index)) {
650 fuse_send_readpages(req, data->file);
651 data->req = req = fuse_get_req(fc);
652 if (IS_ERR(req)) {
653 unlock_page(page);
654 return PTR_ERR(req);
655 }
656 }
657 page_cache_get(page);
658 req->pages[req->num_pages] = page;
659 req->num_pages++;
660 return 0;
661 }
662
663 static int fuse_readpages(struct file *file, struct address_space *mapping,
664 struct list_head *pages, unsigned nr_pages)
665 {
666 struct inode *inode = mapping->host;
667 struct fuse_conn *fc = get_fuse_conn(inode);
668 struct fuse_fill_data data;
669 int err;
670
671 err = -EIO;
672 if (is_bad_inode(inode))
673 goto out;
674
675 data.file = file;
676 data.inode = inode;
677 data.req = fuse_get_req(fc);
678 err = PTR_ERR(data.req);
679 if (IS_ERR(data.req))
680 goto out;
681
682 err = read_cache_pages(mapping, pages, fuse_readpages_fill, &data);
683 if (!err) {
684 if (data.req->num_pages)
685 fuse_send_readpages(data.req, file);
686 else
687 fuse_put_request(fc, data.req);
688 }
689 out:
690 return err;
691 }
692
693 static ssize_t fuse_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
694 unsigned long nr_segs, loff_t pos)
695 {
696 struct inode *inode = iocb->ki_filp->f_mapping->host;
697
698 if (pos + iov_length(iov, nr_segs) > i_size_read(inode)) {
699 int err;
700 /*
701 * If trying to read past EOF, make sure the i_size
702 * attribute is up-to-date.
703 */
704 err = fuse_update_attributes(inode, NULL, iocb->ki_filp, NULL);
705 if (err)
706 return err;
707 }
708
709 return generic_file_aio_read(iocb, iov, nr_segs, pos);
710 }
711
712 static void fuse_write_fill(struct fuse_req *req, struct fuse_file *ff,
713 loff_t pos, size_t count)
714 {
715 struct fuse_write_in *inarg = &req->misc.write.in;
716 struct fuse_write_out *outarg = &req->misc.write.out;
717
718 inarg->fh = ff->fh;
719 inarg->offset = pos;
720 inarg->size = count;
721 req->in.h.opcode = FUSE_WRITE;
722 req->in.h.nodeid = ff->nodeid;
723 req->in.numargs = 2;
724 if (ff->fc->minor < 9)
725 req->in.args[0].size = FUSE_COMPAT_WRITE_IN_SIZE;
726 else
727 req->in.args[0].size = sizeof(struct fuse_write_in);
728 req->in.args[0].value = inarg;
729 req->in.args[1].size = count;
730 req->out.numargs = 1;
731 req->out.args[0].size = sizeof(struct fuse_write_out);
732 req->out.args[0].value = outarg;
733 }
734
735 static size_t fuse_send_write(struct fuse_req *req, struct file *file,
736 loff_t pos, size_t count, fl_owner_t owner)
737 {
738 struct fuse_file *ff = file->private_data;
739 struct fuse_conn *fc = ff->fc;
740 struct fuse_write_in *inarg = &req->misc.write.in;
741
742 fuse_write_fill(req, ff, pos, count);
743 inarg->flags = file->f_flags;
744 if (owner != NULL) {
745 inarg->write_flags |= FUSE_WRITE_LOCKOWNER;
746 inarg->lock_owner = fuse_lock_owner_id(fc, owner);
747 }
748 fuse_request_send(fc, req);
749 return req->misc.write.out.size;
750 }
751
752 static int fuse_write_begin(struct file *file, struct address_space *mapping,
753 loff_t pos, unsigned len, unsigned flags,
754 struct page **pagep, void **fsdata)
755 {
756 pgoff_t index = pos >> PAGE_CACHE_SHIFT;
757
758 *pagep = grab_cache_page_write_begin(mapping, index, flags);
759 if (!*pagep)
760 return -ENOMEM;
761 return 0;
762 }
763
764 void fuse_write_update_size(struct inode *inode, loff_t pos)
765 {
766 struct fuse_conn *fc = get_fuse_conn(inode);
767 struct fuse_inode *fi = get_fuse_inode(inode);
768
769 spin_lock(&fc->lock);
770 fi->attr_version = ++fc->attr_version;
771 if (pos > inode->i_size)
772 i_size_write(inode, pos);
773 spin_unlock(&fc->lock);
774 }
775
776 static int fuse_buffered_write(struct file *file, struct inode *inode,
777 loff_t pos, unsigned count, struct page *page)
778 {
779 int err;
780 size_t nres;
781 struct fuse_conn *fc = get_fuse_conn(inode);
782 unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
783 struct fuse_req *req;
784
785 if (is_bad_inode(inode))
786 return -EIO;
787
788 /*
789 * Make sure writepages on the same page are not mixed up with
790 * plain writes.
791 */
792 fuse_wait_on_page_writeback(inode, page->index);
793
794 req = fuse_get_req(fc);
795 if (IS_ERR(req))
796 return PTR_ERR(req);
797
798 req->in.argpages = 1;
799 req->num_pages = 1;
800 req->pages[0] = page;
801 req->page_offset = offset;
802 nres = fuse_send_write(req, file, pos, count, NULL);
803 err = req->out.h.error;
804 fuse_put_request(fc, req);
805 if (!err && !nres)
806 err = -EIO;
807 if (!err) {
808 pos += nres;
809 fuse_write_update_size(inode, pos);
810 if (count == PAGE_CACHE_SIZE)
811 SetPageUptodate(page);
812 }
813 fuse_invalidate_attr(inode);
814 return err ? err : nres;
815 }
816
817 static int fuse_write_end(struct file *file, struct address_space *mapping,
818 loff_t pos, unsigned len, unsigned copied,
819 struct page *page, void *fsdata)
820 {
821 struct inode *inode = mapping->host;
822 int res = 0;
823
824 if (copied)
825 res = fuse_buffered_write(file, inode, pos, copied, page);
826
827 unlock_page(page);
828 page_cache_release(page);
829 return res;
830 }
831
832 static size_t fuse_send_write_pages(struct fuse_req *req, struct file *file,
833 struct inode *inode, loff_t pos,
834 size_t count)
835 {
836 size_t res;
837 unsigned offset;
838 unsigned i;
839
840 for (i = 0; i < req->num_pages; i++)
841 fuse_wait_on_page_writeback(inode, req->pages[i]->index);
842
843 res = fuse_send_write(req, file, pos, count, NULL);
844
845 offset = req->page_offset;
846 count = res;
847 for (i = 0; i < req->num_pages; i++) {
848 struct page *page = req->pages[i];
849
850 if (!req->out.h.error && !offset && count >= PAGE_CACHE_SIZE)
851 SetPageUptodate(page);
852
853 if (count > PAGE_CACHE_SIZE - offset)
854 count -= PAGE_CACHE_SIZE - offset;
855 else
856 count = 0;
857 offset = 0;
858
859 unlock_page(page);
860 page_cache_release(page);
861 }
862
863 return res;
864 }
865
866 static ssize_t fuse_fill_write_pages(struct fuse_req *req,
867 struct address_space *mapping,
868 struct iov_iter *ii, loff_t pos)
869 {
870 struct fuse_conn *fc = get_fuse_conn(mapping->host);
871 unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
872 size_t count = 0;
873 int err;
874
875 req->in.argpages = 1;
876 req->page_offset = offset;
877
878 do {
879 size_t tmp;
880 struct page *page;
881 pgoff_t index = pos >> PAGE_CACHE_SHIFT;
882 size_t bytes = min_t(size_t, PAGE_CACHE_SIZE - offset,
883 iov_iter_count(ii));
884
885 bytes = min_t(size_t, bytes, fc->max_write - count);
886
887 again:
888 err = -EFAULT;
889 if (iov_iter_fault_in_readable(ii, bytes))
890 break;
891
892 err = -ENOMEM;
893 page = grab_cache_page_write_begin(mapping, index, 0);
894 if (!page)
895 break;
896
897 if (mapping_writably_mapped(mapping))
898 flush_dcache_page(page);
899
900 pagefault_disable();
901 tmp = iov_iter_copy_from_user_atomic(page, ii, offset, bytes);
902 pagefault_enable();
903 flush_dcache_page(page);
904
905 if (!tmp) {
906 unlock_page(page);
907 page_cache_release(page);
908 bytes = min(bytes, iov_iter_single_seg_count(ii));
909 goto again;
910 }
911
912 err = 0;
913 req->pages[req->num_pages] = page;
914 req->num_pages++;
915
916 iov_iter_advance(ii, tmp);
917 count += tmp;
918 pos += tmp;
919 offset += tmp;
920 if (offset == PAGE_CACHE_SIZE)
921 offset = 0;
922
923 if (!fc->big_writes)
924 break;
925 } while (iov_iter_count(ii) && count < fc->max_write &&
926 req->num_pages < FUSE_MAX_PAGES_PER_REQ && offset == 0);
927
928 return count > 0 ? count : err;
929 }
930
931 static ssize_t fuse_perform_write(struct file *file,
932 struct address_space *mapping,
933 struct iov_iter *ii, loff_t pos)
934 {
935 struct inode *inode = mapping->host;
936 struct fuse_conn *fc = get_fuse_conn(inode);
937 int err = 0;
938 ssize_t res = 0;
939
940 if (is_bad_inode(inode))
941 return -EIO;
942
943 do {
944 struct fuse_req *req;
945 ssize_t count;
946
947 req = fuse_get_req(fc);
948 if (IS_ERR(req)) {
949 err = PTR_ERR(req);
950 break;
951 }
952
953 count = fuse_fill_write_pages(req, mapping, ii, pos);
954 if (count <= 0) {
955 err = count;
956 } else {
957 size_t num_written;
958
959 num_written = fuse_send_write_pages(req, file, inode,
960 pos, count);
961 err = req->out.h.error;
962 if (!err) {
963 res += num_written;
964 pos += num_written;
965
966 /* break out of the loop on short write */
967 if (num_written != count)
968 err = -EIO;
969 }
970 }
971 fuse_put_request(fc, req);
972 } while (!err && iov_iter_count(ii));
973
974 if (res > 0)
975 fuse_write_update_size(inode, pos);
976
977 fuse_invalidate_attr(inode);
978
979 return res > 0 ? res : err;
980 }
981
982 static ssize_t fuse_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
983 unsigned long nr_segs, loff_t pos)
984 {
985 struct file *file = iocb->ki_filp;
986 struct address_space *mapping = file->f_mapping;
987 size_t count = 0;
988 ssize_t written = 0;
989 struct inode *inode = mapping->host;
990 ssize_t err;
991 struct iov_iter i;
992
993 WARN_ON(iocb->ki_pos != pos);
994
995 err = generic_segment_checks(iov, &nr_segs, &count, VERIFY_READ);
996 if (err)
997 return err;
998
999 mutex_lock(&inode->i_mutex);
1000 vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
1001
1002 /* We can write back this queue in page reclaim */
1003 current->backing_dev_info = mapping->backing_dev_info;
1004
1005 err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
1006 if (err)
1007 goto out;
1008
1009 if (count == 0)
1010 goto out;
1011
1012 err = file_remove_suid(file);
1013 if (err)
1014 goto out;
1015
1016 file_update_time(file);
1017
1018 iov_iter_init(&i, iov, nr_segs, count, 0);
1019 written = fuse_perform_write(file, mapping, &i, pos);
1020 if (written >= 0)
1021 iocb->ki_pos = pos + written;
1022
1023 out:
1024 current->backing_dev_info = NULL;
1025 mutex_unlock(&inode->i_mutex);
1026
1027 return written ? written : err;
1028 }
1029
1030 static void fuse_release_user_pages(struct fuse_req *req, int write)
1031 {
1032 unsigned i;
1033
1034 for (i = 0; i < req->num_pages; i++) {
1035 struct page *page = req->pages[i];
1036 if (write)
1037 set_page_dirty_lock(page);
1038 put_page(page);
1039 }
1040 }
1041
1042 static int fuse_get_user_pages(struct fuse_req *req, const char __user *buf,
1043 size_t *nbytesp, int write)
1044 {
1045 size_t nbytes = *nbytesp;
1046 unsigned long user_addr = (unsigned long) buf;
1047 unsigned offset = user_addr & ~PAGE_MASK;
1048 int npages;
1049
1050 /* Special case for kernel I/O: can copy directly into the buffer */
1051 if (segment_eq(get_fs(), KERNEL_DS)) {
1052 if (write)
1053 req->in.args[1].value = (void *) user_addr;
1054 else
1055 req->out.args[0].value = (void *) user_addr;
1056
1057 return 0;
1058 }
1059
1060 nbytes = min_t(size_t, nbytes, FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT);
1061 npages = (nbytes + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
1062 npages = clamp(npages, 1, FUSE_MAX_PAGES_PER_REQ);
1063 npages = get_user_pages_fast(user_addr, npages, !write, req->pages);
1064 if (npages < 0)
1065 return npages;
1066
1067 req->num_pages = npages;
1068 req->page_offset = offset;
1069
1070 if (write)
1071 req->in.argpages = 1;
1072 else
1073 req->out.argpages = 1;
1074
1075 nbytes = (req->num_pages << PAGE_SHIFT) - req->page_offset;
1076 *nbytesp = min(*nbytesp, nbytes);
1077
1078 return 0;
1079 }
1080
1081 ssize_t fuse_direct_io(struct file *file, const char __user *buf,
1082 size_t count, loff_t *ppos, int write)
1083 {
1084 struct fuse_file *ff = file->private_data;
1085 struct fuse_conn *fc = ff->fc;
1086 size_t nmax = write ? fc->max_write : fc->max_read;
1087 loff_t pos = *ppos;
1088 ssize_t res = 0;
1089 struct fuse_req *req;
1090
1091 req = fuse_get_req(fc);
1092 if (IS_ERR(req))
1093 return PTR_ERR(req);
1094
1095 while (count) {
1096 size_t nres;
1097 fl_owner_t owner = current->files;
1098 size_t nbytes = min(count, nmax);
1099 int err = fuse_get_user_pages(req, buf, &nbytes, write);
1100 if (err) {
1101 res = err;
1102 break;
1103 }
1104
1105 if (write)
1106 nres = fuse_send_write(req, file, pos, nbytes, owner);
1107 else
1108 nres = fuse_send_read(req, file, pos, nbytes, owner);
1109
1110 fuse_release_user_pages(req, !write);
1111 if (req->out.h.error) {
1112 if (!res)
1113 res = req->out.h.error;
1114 break;
1115 } else if (nres > nbytes) {
1116 res = -EIO;
1117 break;
1118 }
1119 count -= nres;
1120 res += nres;
1121 pos += nres;
1122 buf += nres;
1123 if (nres != nbytes)
1124 break;
1125 if (count) {
1126 fuse_put_request(fc, req);
1127 req = fuse_get_req(fc);
1128 if (IS_ERR(req))
1129 break;
1130 }
1131 }
1132 if (!IS_ERR(req))
1133 fuse_put_request(fc, req);
1134 if (res > 0)
1135 *ppos = pos;
1136
1137 return res;
1138 }
1139 EXPORT_SYMBOL_GPL(fuse_direct_io);
1140
1141 static ssize_t fuse_direct_read(struct file *file, char __user *buf,
1142 size_t count, loff_t *ppos)
1143 {
1144 ssize_t res;
1145 struct inode *inode = file->f_path.dentry->d_inode;
1146
1147 if (is_bad_inode(inode))
1148 return -EIO;
1149
1150 res = fuse_direct_io(file, buf, count, ppos, 0);
1151
1152 fuse_invalidate_attr(inode);
1153
1154 return res;
1155 }
1156
1157 static ssize_t fuse_direct_write(struct file *file, const char __user *buf,
1158 size_t count, loff_t *ppos)
1159 {
1160 struct inode *inode = file->f_path.dentry->d_inode;
1161 ssize_t res;
1162
1163 if (is_bad_inode(inode))
1164 return -EIO;
1165
1166 /* Don't allow parallel writes to the same file */
1167 mutex_lock(&inode->i_mutex);
1168 res = generic_write_checks(file, ppos, &count, 0);
1169 if (!res) {
1170 res = fuse_direct_io(file, buf, count, ppos, 1);
1171 if (res > 0)
1172 fuse_write_update_size(inode, *ppos);
1173 }
1174 mutex_unlock(&inode->i_mutex);
1175
1176 fuse_invalidate_attr(inode);
1177
1178 return res;
1179 }
1180
1181 static void fuse_writepage_free(struct fuse_conn *fc, struct fuse_req *req)
1182 {
1183 __free_page(req->pages[0]);
1184 fuse_file_put(req->ff, false);
1185 }
1186
1187 static void fuse_writepage_finish(struct fuse_conn *fc, struct fuse_req *req)
1188 {
1189 struct inode *inode = req->inode;
1190 struct fuse_inode *fi = get_fuse_inode(inode);
1191 struct backing_dev_info *bdi = inode->i_mapping->backing_dev_info;
1192
1193 list_del(&req->writepages_entry);
1194 dec_bdi_stat(bdi, BDI_WRITEBACK);
1195 dec_zone_page_state(req->pages[0], NR_WRITEBACK_TEMP);
1196 bdi_writeout_inc(bdi);
1197 wake_up(&fi->page_waitq);
1198 }
1199
1200 /* Called under fc->lock, may release and reacquire it */
1201 static void fuse_send_writepage(struct fuse_conn *fc, struct fuse_req *req)
1202 __releases(fc->lock)
1203 __acquires(fc->lock)
1204 {
1205 struct fuse_inode *fi = get_fuse_inode(req->inode);
1206 loff_t size = i_size_read(req->inode);
1207 struct fuse_write_in *inarg = &req->misc.write.in;
1208
1209 if (!fc->connected)
1210 goto out_free;
1211
1212 if (inarg->offset + PAGE_CACHE_SIZE <= size) {
1213 inarg->size = PAGE_CACHE_SIZE;
1214 } else if (inarg->offset < size) {
1215 inarg->size = size & (PAGE_CACHE_SIZE - 1);
1216 } else {
1217 /* Got truncated off completely */
1218 goto out_free;
1219 }
1220
1221 req->in.args[1].size = inarg->size;
1222 fi->writectr++;
1223 fuse_request_send_background_locked(fc, req);
1224 return;
1225
1226 out_free:
1227 fuse_writepage_finish(fc, req);
1228 spin_unlock(&fc->lock);
1229 fuse_writepage_free(fc, req);
1230 fuse_put_request(fc, req);
1231 spin_lock(&fc->lock);
1232 }
1233
1234 /*
1235 * If fi->writectr is positive (no truncate or fsync going on) send
1236 * all queued writepage requests.
1237 *
1238 * Called with fc->lock
1239 */
1240 void fuse_flush_writepages(struct inode *inode)
1241 __releases(fc->lock)
1242 __acquires(fc->lock)
1243 {
1244 struct fuse_conn *fc = get_fuse_conn(inode);
1245 struct fuse_inode *fi = get_fuse_inode(inode);
1246 struct fuse_req *req;
1247
1248 while (fi->writectr >= 0 && !list_empty(&fi->queued_writes)) {
1249 req = list_entry(fi->queued_writes.next, struct fuse_req, list);
1250 list_del_init(&req->list);
1251 fuse_send_writepage(fc, req);
1252 }
1253 }
1254
1255 static void fuse_writepage_end(struct fuse_conn *fc, struct fuse_req *req)
1256 {
1257 struct inode *inode = req->inode;
1258 struct fuse_inode *fi = get_fuse_inode(inode);
1259
1260 mapping_set_error(inode->i_mapping, req->out.h.error);
1261 spin_lock(&fc->lock);
1262 fi->writectr--;
1263 fuse_writepage_finish(fc, req);
1264 spin_unlock(&fc->lock);
1265 fuse_writepage_free(fc, req);
1266 }
1267
1268 static int fuse_writepage_locked(struct page *page)
1269 {
1270 struct address_space *mapping = page->mapping;
1271 struct inode *inode = mapping->host;
1272 struct fuse_conn *fc = get_fuse_conn(inode);
1273 struct fuse_inode *fi = get_fuse_inode(inode);
1274 struct fuse_req *req;
1275 struct fuse_file *ff;
1276 struct page *tmp_page;
1277
1278 set_page_writeback(page);
1279
1280 req = fuse_request_alloc_nofs();
1281 if (!req)
1282 goto err;
1283
1284 tmp_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
1285 if (!tmp_page)
1286 goto err_free;
1287
1288 spin_lock(&fc->lock);
1289 BUG_ON(list_empty(&fi->write_files));
1290 ff = list_entry(fi->write_files.next, struct fuse_file, write_entry);
1291 req->ff = fuse_file_get(ff);
1292 spin_unlock(&fc->lock);
1293
1294 fuse_write_fill(req, ff, page_offset(page), 0);
1295
1296 copy_highpage(tmp_page, page);
1297 req->misc.write.in.write_flags |= FUSE_WRITE_CACHE;
1298 req->in.argpages = 1;
1299 req->num_pages = 1;
1300 req->pages[0] = tmp_page;
1301 req->page_offset = 0;
1302 req->end = fuse_writepage_end;
1303 req->inode = inode;
1304
1305 inc_bdi_stat(mapping->backing_dev_info, BDI_WRITEBACK);
1306 inc_zone_page_state(tmp_page, NR_WRITEBACK_TEMP);
1307 end_page_writeback(page);
1308
1309 spin_lock(&fc->lock);
1310 list_add(&req->writepages_entry, &fi->writepages);
1311 list_add_tail(&req->list, &fi->queued_writes);
1312 fuse_flush_writepages(inode);
1313 spin_unlock(&fc->lock);
1314
1315 return 0;
1316
1317 err_free:
1318 fuse_request_free(req);
1319 err:
1320 end_page_writeback(page);
1321 return -ENOMEM;
1322 }
1323
1324 static int fuse_writepage(struct page *page, struct writeback_control *wbc)
1325 {
1326 int err;
1327
1328 err = fuse_writepage_locked(page);
1329 unlock_page(page);
1330
1331 return err;
1332 }
1333
1334 static int fuse_launder_page(struct page *page)
1335 {
1336 int err = 0;
1337 if (clear_page_dirty_for_io(page)) {
1338 struct inode *inode = page->mapping->host;
1339 err = fuse_writepage_locked(page);
1340 if (!err)
1341 fuse_wait_on_page_writeback(inode, page->index);
1342 }
1343 return err;
1344 }
1345
1346 /*
1347 * Write back dirty pages now, because there may not be any suitable
1348 * open files later
1349 */
1350 static void fuse_vma_close(struct vm_area_struct *vma)
1351 {
1352 filemap_write_and_wait(vma->vm_file->f_mapping);
1353 }
1354
1355 /*
1356 * Wait for writeback against this page to complete before allowing it
1357 * to be marked dirty again, and hence written back again, possibly
1358 * before the previous writepage completed.
1359 *
1360 * Block here, instead of in ->writepage(), so that the userspace fs
1361 * can only block processes actually operating on the filesystem.
1362 *
1363 * Otherwise unprivileged userspace fs would be able to block
1364 * unrelated:
1365 *
1366 * - page migration
1367 * - sync(2)
1368 * - try_to_free_pages() with order > PAGE_ALLOC_COSTLY_ORDER
1369 */
1370 static int fuse_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
1371 {
1372 struct page *page = vmf->page;
1373 /*
1374 * Don't use page->mapping as it may become NULL from a
1375 * concurrent truncate.
1376 */
1377 struct inode *inode = vma->vm_file->f_mapping->host;
1378
1379 fuse_wait_on_page_writeback(inode, page->index);
1380 return 0;
1381 }
1382
1383 static const struct vm_operations_struct fuse_file_vm_ops = {
1384 .close = fuse_vma_close,
1385 .fault = filemap_fault,
1386 .page_mkwrite = fuse_page_mkwrite,
1387 };
1388
1389 static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma)
1390 {
1391 if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_MAYWRITE)) {
1392 struct inode *inode = file->f_dentry->d_inode;
1393 struct fuse_conn *fc = get_fuse_conn(inode);
1394 struct fuse_inode *fi = get_fuse_inode(inode);
1395 struct fuse_file *ff = file->private_data;
1396 /*
1397 * file may be written through mmap, so chain it onto the
1398 * inodes's write_file list
1399 */
1400 spin_lock(&fc->lock);
1401 if (list_empty(&ff->write_entry))
1402 list_add(&ff->write_entry, &fi->write_files);
1403 spin_unlock(&fc->lock);
1404 }
1405 file_accessed(file);
1406 vma->vm_ops = &fuse_file_vm_ops;
1407 return 0;
1408 }
1409
1410 static int fuse_direct_mmap(struct file *file, struct vm_area_struct *vma)
1411 {
1412 /* Can't provide the coherency needed for MAP_SHARED */
1413 if (vma->vm_flags & VM_MAYSHARE)
1414 return -ENODEV;
1415
1416 invalidate_inode_pages2(file->f_mapping);
1417
1418 return generic_file_mmap(file, vma);
1419 }
1420
1421 static int convert_fuse_file_lock(const struct fuse_file_lock *ffl,
1422 struct file_lock *fl)
1423 {
1424 switch (ffl->type) {
1425 case F_UNLCK:
1426 break;
1427
1428 case F_RDLCK:
1429 case F_WRLCK:
1430 if (ffl->start > OFFSET_MAX || ffl->end > OFFSET_MAX ||
1431 ffl->end < ffl->start)
1432 return -EIO;
1433
1434 fl->fl_start = ffl->start;
1435 fl->fl_end = ffl->end;
1436 fl->fl_pid = ffl->pid;
1437 break;
1438
1439 default:
1440 return -EIO;
1441 }
1442 fl->fl_type = ffl->type;
1443 return 0;
1444 }
1445
1446 static void fuse_lk_fill(struct fuse_req *req, struct file *file,
1447 const struct file_lock *fl, int opcode, pid_t pid,
1448 int flock)
1449 {
1450 struct inode *inode = file->f_path.dentry->d_inode;
1451 struct fuse_conn *fc = get_fuse_conn(inode);
1452 struct fuse_file *ff = file->private_data;
1453 struct fuse_lk_in *arg = &req->misc.lk_in;
1454
1455 arg->fh = ff->fh;
1456 arg->owner = fuse_lock_owner_id(fc, fl->fl_owner);
1457 arg->lk.start = fl->fl_start;
1458 arg->lk.end = fl->fl_end;
1459 arg->lk.type = fl->fl_type;
1460 arg->lk.pid = pid;
1461 if (flock)
1462 arg->lk_flags |= FUSE_LK_FLOCK;
1463 req->in.h.opcode = opcode;
1464 req->in.h.nodeid = get_node_id(inode);
1465 req->in.numargs = 1;
1466 req->in.args[0].size = sizeof(*arg);
1467 req->in.args[0].value = arg;
1468 }
1469
1470 static int fuse_getlk(struct file *file, struct file_lock *fl)
1471 {
1472 struct inode *inode = file->f_path.dentry->d_inode;
1473 struct fuse_conn *fc = get_fuse_conn(inode);
1474 struct fuse_req *req;
1475 struct fuse_lk_out outarg;
1476 int err;
1477
1478 req = fuse_get_req(fc);
1479 if (IS_ERR(req))
1480 return PTR_ERR(req);
1481
1482 fuse_lk_fill(req, file, fl, FUSE_GETLK, 0, 0);
1483 req->out.numargs = 1;
1484 req->out.args[0].size = sizeof(outarg);
1485 req->out.args[0].value = &outarg;
1486 fuse_request_send(fc, req);
1487 err = req->out.h.error;
1488 fuse_put_request(fc, req);
1489 if (!err)
1490 err = convert_fuse_file_lock(&outarg.lk, fl);
1491
1492 return err;
1493 }
1494
1495 static int fuse_setlk(struct file *file, struct file_lock *fl, int flock)
1496 {
1497 struct inode *inode = file->f_path.dentry->d_inode;
1498 struct fuse_conn *fc = get_fuse_conn(inode);
1499 struct fuse_req *req;
1500 int opcode = (fl->fl_flags & FL_SLEEP) ? FUSE_SETLKW : FUSE_SETLK;
1501 pid_t pid = fl->fl_type != F_UNLCK ? current->tgid : 0;
1502 int err;
1503
1504 if (fl->fl_lmops && fl->fl_lmops->fl_grant) {
1505 /* NLM needs asynchronous locks, which we don't support yet */
1506 return -ENOLCK;
1507 }
1508
1509 /* Unlock on close is handled by the flush method */
1510 if (fl->fl_flags & FL_CLOSE)
1511 return 0;
1512
1513 req = fuse_get_req(fc);
1514 if (IS_ERR(req))
1515 return PTR_ERR(req);
1516
1517 fuse_lk_fill(req, file, fl, opcode, pid, flock);
1518 fuse_request_send(fc, req);
1519 err = req->out.h.error;
1520 /* locking is restartable */
1521 if (err == -EINTR)
1522 err = -ERESTARTSYS;
1523 fuse_put_request(fc, req);
1524 return err;
1525 }
1526
1527 static int fuse_file_lock(struct file *file, int cmd, struct file_lock *fl)
1528 {
1529 struct inode *inode = file->f_path.dentry->d_inode;
1530 struct fuse_conn *fc = get_fuse_conn(inode);
1531 int err;
1532
1533 if (cmd == F_CANCELLK) {
1534 err = 0;
1535 } else if (cmd == F_GETLK) {
1536 if (fc->no_lock) {
1537 posix_test_lock(file, fl);
1538 err = 0;
1539 } else
1540 err = fuse_getlk(file, fl);
1541 } else {
1542 if (fc->no_lock)
1543 err = posix_lock_file(file, fl, NULL);
1544 else
1545 err = fuse_setlk(file, fl, 0);
1546 }
1547 return err;
1548 }
1549
1550 static int fuse_file_flock(struct file *file, int cmd, struct file_lock *fl)
1551 {
1552 struct inode *inode = file->f_path.dentry->d_inode;
1553 struct fuse_conn *fc = get_fuse_conn(inode);
1554 int err;
1555
1556 if (fc->no_flock) {
1557 err = flock_lock_file_wait(file, fl);
1558 } else {
1559 struct fuse_file *ff = file->private_data;
1560
1561 /* emulate flock with POSIX locks */
1562 fl->fl_owner = (fl_owner_t) file;
1563 ff->flock = true;
1564 err = fuse_setlk(file, fl, 1);
1565 }
1566
1567 return err;
1568 }
1569
1570 static sector_t fuse_bmap(struct address_space *mapping, sector_t block)
1571 {
1572 struct inode *inode = mapping->host;
1573 struct fuse_conn *fc = get_fuse_conn(inode);
1574 struct fuse_req *req;
1575 struct fuse_bmap_in inarg;
1576 struct fuse_bmap_out outarg;
1577 int err;
1578
1579 if (!inode->i_sb->s_bdev || fc->no_bmap)
1580 return 0;
1581
1582 req = fuse_get_req(fc);
1583 if (IS_ERR(req))
1584 return 0;
1585
1586 memset(&inarg, 0, sizeof(inarg));
1587 inarg.block = block;
1588 inarg.blocksize = inode->i_sb->s_blocksize;
1589 req->in.h.opcode = FUSE_BMAP;
1590 req->in.h.nodeid = get_node_id(inode);
1591 req->in.numargs = 1;
1592 req->in.args[0].size = sizeof(inarg);
1593 req->in.args[0].value = &inarg;
1594 req->out.numargs = 1;
1595 req->out.args[0].size = sizeof(outarg);
1596 req->out.args[0].value = &outarg;
1597 fuse_request_send(fc, req);
1598 err = req->out.h.error;
1599 fuse_put_request(fc, req);
1600 if (err == -ENOSYS)
1601 fc->no_bmap = 1;
1602
1603 return err ? 0 : outarg.block;
1604 }
1605
1606 static loff_t fuse_file_llseek(struct file *file, loff_t offset, int origin)
1607 {
1608 loff_t retval;
1609 struct inode *inode = file->f_path.dentry->d_inode;
1610
1611 mutex_lock(&inode->i_mutex);
1612 switch (origin) {
1613 case SEEK_END:
1614 retval = fuse_update_attributes(inode, NULL, file, NULL);
1615 if (retval)
1616 goto exit;
1617 offset += i_size_read(inode);
1618 break;
1619 case SEEK_CUR:
1620 offset += file->f_pos;
1621 }
1622 retval = -EINVAL;
1623 if (offset >= 0 && offset <= inode->i_sb->s_maxbytes) {
1624 if (offset != file->f_pos) {
1625 file->f_pos = offset;
1626 file->f_version = 0;
1627 }
1628 retval = offset;
1629 }
1630 exit:
1631 mutex_unlock(&inode->i_mutex);
1632 return retval;
1633 }
1634
1635 static int fuse_ioctl_copy_user(struct page **pages, struct iovec *iov,
1636 unsigned int nr_segs, size_t bytes, bool to_user)
1637 {
1638 struct iov_iter ii;
1639 int page_idx = 0;
1640
1641 if (!bytes)
1642 return 0;
1643
1644 iov_iter_init(&ii, iov, nr_segs, bytes, 0);
1645
1646 while (iov_iter_count(&ii)) {
1647 struct page *page = pages[page_idx++];
1648 size_t todo = min_t(size_t, PAGE_SIZE, iov_iter_count(&ii));
1649 void *kaddr;
1650
1651 kaddr = kmap(page);
1652
1653 while (todo) {
1654 char __user *uaddr = ii.iov->iov_base + ii.iov_offset;
1655 size_t iov_len = ii.iov->iov_len - ii.iov_offset;
1656 size_t copy = min(todo, iov_len);
1657 size_t left;
1658
1659 if (!to_user)
1660 left = copy_from_user(kaddr, uaddr, copy);
1661 else
1662 left = copy_to_user(uaddr, kaddr, copy);
1663
1664 if (unlikely(left))
1665 return -EFAULT;
1666
1667 iov_iter_advance(&ii, copy);
1668 todo -= copy;
1669 kaddr += copy;
1670 }
1671
1672 kunmap(page);
1673 }
1674
1675 return 0;
1676 }
1677
1678 /*
1679 * CUSE servers compiled on 32bit broke on 64bit kernels because the
1680 * ABI was defined to be 'struct iovec' which is different on 32bit
1681 * and 64bit. Fortunately we can determine which structure the server
1682 * used from the size of the reply.
1683 */
1684 static int fuse_copy_ioctl_iovec_old(struct iovec *dst, void *src,
1685 size_t transferred, unsigned count,
1686 bool is_compat)
1687 {
1688 #ifdef CONFIG_COMPAT
1689 if (count * sizeof(struct compat_iovec) == transferred) {
1690 struct compat_iovec *ciov = src;
1691 unsigned i;
1692
1693 /*
1694 * With this interface a 32bit server cannot support
1695 * non-compat (i.e. ones coming from 64bit apps) ioctl
1696 * requests
1697 */
1698 if (!is_compat)
1699 return -EINVAL;
1700
1701 for (i = 0; i < count; i++) {
1702 dst[i].iov_base = compat_ptr(ciov[i].iov_base);
1703 dst[i].iov_len = ciov[i].iov_len;
1704 }
1705 return 0;
1706 }
1707 #endif
1708
1709 if (count * sizeof(struct iovec) != transferred)
1710 return -EIO;
1711
1712 memcpy(dst, src, transferred);
1713 return 0;
1714 }
1715
1716 /* Make sure iov_length() won't overflow */
1717 static int fuse_verify_ioctl_iov(struct iovec *iov, size_t count)
1718 {
1719 size_t n;
1720 u32 max = FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT;
1721
1722 for (n = 0; n < count; n++) {
1723 if (iov->iov_len > (size_t) max)
1724 return -ENOMEM;
1725 max -= iov->iov_len;
1726 }
1727 return 0;
1728 }
1729
1730 static int fuse_copy_ioctl_iovec(struct fuse_conn *fc, struct iovec *dst,
1731 void *src, size_t transferred, unsigned count,
1732 bool is_compat)
1733 {
1734 unsigned i;
1735 struct fuse_ioctl_iovec *fiov = src;
1736
1737 if (fc->minor < 16) {
1738 return fuse_copy_ioctl_iovec_old(dst, src, transferred,
1739 count, is_compat);
1740 }
1741
1742 if (count * sizeof(struct fuse_ioctl_iovec) != transferred)
1743 return -EIO;
1744
1745 for (i = 0; i < count; i++) {
1746 /* Did the server supply an inappropriate value? */
1747 if (fiov[i].base != (unsigned long) fiov[i].base ||
1748 fiov[i].len != (unsigned long) fiov[i].len)
1749 return -EIO;
1750
1751 dst[i].iov_base = (void __user *) (unsigned long) fiov[i].base;
1752 dst[i].iov_len = (size_t) fiov[i].len;
1753
1754 #ifdef CONFIG_COMPAT
1755 if (is_compat &&
1756 (ptr_to_compat(dst[i].iov_base) != fiov[i].base ||
1757 (compat_size_t) dst[i].iov_len != fiov[i].len))
1758 return -EIO;
1759 #endif
1760 }
1761
1762 return 0;
1763 }
1764
1765
1766 /*
1767 * For ioctls, there is no generic way to determine how much memory
1768 * needs to be read and/or written. Furthermore, ioctls are allowed
1769 * to dereference the passed pointer, so the parameter requires deep
1770 * copying but FUSE has no idea whatsoever about what to copy in or
1771 * out.
1772 *
1773 * This is solved by allowing FUSE server to retry ioctl with
1774 * necessary in/out iovecs. Let's assume the ioctl implementation
1775 * needs to read in the following structure.
1776 *
1777 * struct a {
1778 * char *buf;
1779 * size_t buflen;
1780 * }
1781 *
1782 * On the first callout to FUSE server, inarg->in_size and
1783 * inarg->out_size will be NULL; then, the server completes the ioctl
1784 * with FUSE_IOCTL_RETRY set in out->flags, out->in_iovs set to 1 and
1785 * the actual iov array to
1786 *
1787 * { { .iov_base = inarg.arg, .iov_len = sizeof(struct a) } }
1788 *
1789 * which tells FUSE to copy in the requested area and retry the ioctl.
1790 * On the second round, the server has access to the structure and
1791 * from that it can tell what to look for next, so on the invocation,
1792 * it sets FUSE_IOCTL_RETRY, out->in_iovs to 2 and iov array to
1793 *
1794 * { { .iov_base = inarg.arg, .iov_len = sizeof(struct a) },
1795 * { .iov_base = a.buf, .iov_len = a.buflen } }
1796 *
1797 * FUSE will copy both struct a and the pointed buffer from the
1798 * process doing the ioctl and retry ioctl with both struct a and the
1799 * buffer.
1800 *
1801 * This time, FUSE server has everything it needs and completes ioctl
1802 * without FUSE_IOCTL_RETRY which finishes the ioctl call.
1803 *
1804 * Copying data out works the same way.
1805 *
1806 * Note that if FUSE_IOCTL_UNRESTRICTED is clear, the kernel
1807 * automatically initializes in and out iovs by decoding @cmd with
1808 * _IOC_* macros and the server is not allowed to request RETRY. This
1809 * limits ioctl data transfers to well-formed ioctls and is the forced
1810 * behavior for all FUSE servers.
1811 */
1812 long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
1813 unsigned int flags)
1814 {
1815 struct fuse_file *ff = file->private_data;
1816 struct fuse_conn *fc = ff->fc;
1817 struct fuse_ioctl_in inarg = {
1818 .fh = ff->fh,
1819 .cmd = cmd,
1820 .arg = arg,
1821 .flags = flags
1822 };
1823 struct fuse_ioctl_out outarg;
1824 struct fuse_req *req = NULL;
1825 struct page **pages = NULL;
1826 struct iovec *iov_page = NULL;
1827 struct iovec *in_iov = NULL, *out_iov = NULL;
1828 unsigned int in_iovs = 0, out_iovs = 0, num_pages = 0, max_pages;
1829 size_t in_size, out_size, transferred;
1830 int err;
1831
1832 #if BITS_PER_LONG == 32
1833 inarg.flags |= FUSE_IOCTL_32BIT;
1834 #else
1835 if (flags & FUSE_IOCTL_COMPAT)
1836 inarg.flags |= FUSE_IOCTL_32BIT;
1837 #endif
1838
1839 /* assume all the iovs returned by client always fits in a page */
1840 BUILD_BUG_ON(sizeof(struct fuse_ioctl_iovec) * FUSE_IOCTL_MAX_IOV > PAGE_SIZE);
1841
1842 err = -ENOMEM;
1843 pages = kzalloc(sizeof(pages[0]) * FUSE_MAX_PAGES_PER_REQ, GFP_KERNEL);
1844 iov_page = (struct iovec *) __get_free_page(GFP_KERNEL);
1845 if (!pages || !iov_page)
1846 goto out;
1847
1848 /*
1849 * If restricted, initialize IO parameters as encoded in @cmd.
1850 * RETRY from server is not allowed.
1851 */
1852 if (!(flags & FUSE_IOCTL_UNRESTRICTED)) {
1853 struct iovec *iov = iov_page;
1854
1855 iov->iov_base = (void __user *)arg;
1856 iov->iov_len = _IOC_SIZE(cmd);
1857
1858 if (_IOC_DIR(cmd) & _IOC_WRITE) {
1859 in_iov = iov;
1860 in_iovs = 1;
1861 }
1862
1863 if (_IOC_DIR(cmd) & _IOC_READ) {
1864 out_iov = iov;
1865 out_iovs = 1;
1866 }
1867 }
1868
1869 retry:
1870 inarg.in_size = in_size = iov_length(in_iov, in_iovs);
1871 inarg.out_size = out_size = iov_length(out_iov, out_iovs);
1872
1873 /*
1874 * Out data can be used either for actual out data or iovs,
1875 * make sure there always is at least one page.
1876 */
1877 out_size = max_t(size_t, out_size, PAGE_SIZE);
1878 max_pages = DIV_ROUND_UP(max(in_size, out_size), PAGE_SIZE);
1879
1880 /* make sure there are enough buffer pages and init request with them */
1881 err = -ENOMEM;
1882 if (max_pages > FUSE_MAX_PAGES_PER_REQ)
1883 goto out;
1884 while (num_pages < max_pages) {
1885 pages[num_pages] = alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
1886 if (!pages[num_pages])
1887 goto out;
1888 num_pages++;
1889 }
1890
1891 req = fuse_get_req(fc);
1892 if (IS_ERR(req)) {
1893 err = PTR_ERR(req);
1894 req = NULL;
1895 goto out;
1896 }
1897 memcpy(req->pages, pages, sizeof(req->pages[0]) * num_pages);
1898 req->num_pages = num_pages;
1899
1900 /* okay, let's send it to the client */
1901 req->in.h.opcode = FUSE_IOCTL;
1902 req->in.h.nodeid = ff->nodeid;
1903 req->in.numargs = 1;
1904 req->in.args[0].size = sizeof(inarg);
1905 req->in.args[0].value = &inarg;
1906 if (in_size) {
1907 req->in.numargs++;
1908 req->in.args[1].size = in_size;
1909 req->in.argpages = 1;
1910
1911 err = fuse_ioctl_copy_user(pages, in_iov, in_iovs, in_size,
1912 false);
1913 if (err)
1914 goto out;
1915 }
1916
1917 req->out.numargs = 2;
1918 req->out.args[0].size = sizeof(outarg);
1919 req->out.args[0].value = &outarg;
1920 req->out.args[1].size = out_size;
1921 req->out.argpages = 1;
1922 req->out.argvar = 1;
1923
1924 fuse_request_send(fc, req);
1925 err = req->out.h.error;
1926 transferred = req->out.args[1].size;
1927 fuse_put_request(fc, req);
1928 req = NULL;
1929 if (err)
1930 goto out;
1931
1932 /* did it ask for retry? */
1933 if (outarg.flags & FUSE_IOCTL_RETRY) {
1934 void *vaddr;
1935
1936 /* no retry if in restricted mode */
1937 err = -EIO;
1938 if (!(flags & FUSE_IOCTL_UNRESTRICTED))
1939 goto out;
1940
1941 in_iovs = outarg.in_iovs;
1942 out_iovs = outarg.out_iovs;
1943
1944 /*
1945 * Make sure things are in boundary, separate checks
1946 * are to protect against overflow.
1947 */
1948 err = -ENOMEM;
1949 if (in_iovs > FUSE_IOCTL_MAX_IOV ||
1950 out_iovs > FUSE_IOCTL_MAX_IOV ||
1951 in_iovs + out_iovs > FUSE_IOCTL_MAX_IOV)
1952 goto out;
1953
1954 vaddr = kmap_atomic(pages[0], KM_USER0);
1955 err = fuse_copy_ioctl_iovec(fc, iov_page, vaddr,
1956 transferred, in_iovs + out_iovs,
1957 (flags & FUSE_IOCTL_COMPAT) != 0);
1958 kunmap_atomic(vaddr, KM_USER0);
1959 if (err)
1960 goto out;
1961
1962 in_iov = iov_page;
1963 out_iov = in_iov + in_iovs;
1964
1965 err = fuse_verify_ioctl_iov(in_iov, in_iovs);
1966 if (err)
1967 goto out;
1968
1969 err = fuse_verify_ioctl_iov(out_iov, out_iovs);
1970 if (err)
1971 goto out;
1972
1973 goto retry;
1974 }
1975
1976 err = -EIO;
1977 if (transferred > inarg.out_size)
1978 goto out;
1979
1980 err = fuse_ioctl_copy_user(pages, out_iov, out_iovs, transferred, true);
1981 out:
1982 if (req)
1983 fuse_put_request(fc, req);
1984 free_page((unsigned long) iov_page);
1985 while (num_pages)
1986 __free_page(pages[--num_pages]);
1987 kfree(pages);
1988
1989 return err ? err : outarg.result;
1990 }
1991 EXPORT_SYMBOL_GPL(fuse_do_ioctl);
1992
1993 static long fuse_file_ioctl_common(struct file *file, unsigned int cmd,
1994 unsigned long arg, unsigned int flags)
1995 {
1996 struct inode *inode = file->f_dentry->d_inode;
1997 struct fuse_conn *fc = get_fuse_conn(inode);
1998
1999 if (!fuse_allow_task(fc, current))
2000 return -EACCES;
2001
2002 if (is_bad_inode(inode))
2003 return -EIO;
2004
2005 return fuse_do_ioctl(file, cmd, arg, flags);
2006 }
2007
2008 static long fuse_file_ioctl(struct file *file, unsigned int cmd,
2009 unsigned long arg)
2010 {
2011 return fuse_file_ioctl_common(file, cmd, arg, 0);
2012 }
2013
2014 static long fuse_file_compat_ioctl(struct file *file, unsigned int cmd,
2015 unsigned long arg)
2016 {
2017 return fuse_file_ioctl_common(file, cmd, arg, FUSE_IOCTL_COMPAT);
2018 }
2019
2020 /*
2021 * All files which have been polled are linked to RB tree
2022 * fuse_conn->polled_files which is indexed by kh. Walk the tree and
2023 * find the matching one.
2024 */
2025 static struct rb_node **fuse_find_polled_node(struct fuse_conn *fc, u64 kh,
2026 struct rb_node **parent_out)
2027 {
2028 struct rb_node **link = &fc->polled_files.rb_node;
2029 struct rb_node *last = NULL;
2030
2031 while (*link) {
2032 struct fuse_file *ff;
2033
2034 last = *link;
2035 ff = rb_entry(last, struct fuse_file, polled_node);
2036
2037 if (kh < ff->kh)
2038 link = &last->rb_left;
2039 else if (kh > ff->kh)
2040 link = &last->rb_right;
2041 else
2042 return link;
2043 }
2044
2045 if (parent_out)
2046 *parent_out = last;
2047 return link;
2048 }
2049
2050 /*
2051 * The file is about to be polled. Make sure it's on the polled_files
2052 * RB tree. Note that files once added to the polled_files tree are
2053 * not removed before the file is released. This is because a file
2054 * polled once is likely to be polled again.
2055 */
2056 static void fuse_register_polled_file(struct fuse_conn *fc,
2057 struct fuse_file *ff)
2058 {
2059 spin_lock(&fc->lock);
2060 if (RB_EMPTY_NODE(&ff->polled_node)) {
2061 struct rb_node **link, *parent;
2062
2063 link = fuse_find_polled_node(fc, ff->kh, &parent);
2064 BUG_ON(*link);
2065 rb_link_node(&ff->polled_node, parent, link);
2066 rb_insert_color(&ff->polled_node, &fc->polled_files);
2067 }
2068 spin_unlock(&fc->lock);
2069 }
2070
2071 unsigned fuse_file_poll(struct file *file, poll_table *wait)
2072 {
2073 struct fuse_file *ff = file->private_data;
2074 struct fuse_conn *fc = ff->fc;
2075 struct fuse_poll_in inarg = { .fh = ff->fh, .kh = ff->kh };
2076 struct fuse_poll_out outarg;
2077 struct fuse_req *req;
2078 int err;
2079
2080 if (fc->no_poll)
2081 return DEFAULT_POLLMASK;
2082
2083 poll_wait(file, &ff->poll_wait, wait);
2084
2085 /*
2086 * Ask for notification iff there's someone waiting for it.
2087 * The client may ignore the flag and always notify.
2088 */
2089 if (waitqueue_active(&ff->poll_wait)) {
2090 inarg.flags |= FUSE_POLL_SCHEDULE_NOTIFY;
2091 fuse_register_polled_file(fc, ff);
2092 }
2093
2094 req = fuse_get_req(fc);
2095 if (IS_ERR(req))
2096 return POLLERR;
2097
2098 req->in.h.opcode = FUSE_POLL;
2099 req->in.h.nodeid = ff->nodeid;
2100 req->in.numargs = 1;
2101 req->in.args[0].size = sizeof(inarg);
2102 req->in.args[0].value = &inarg;
2103 req->out.numargs = 1;
2104 req->out.args[0].size = sizeof(outarg);
2105 req->out.args[0].value = &outarg;
2106 fuse_request_send(fc, req);
2107 err = req->out.h.error;
2108 fuse_put_request(fc, req);
2109
2110 if (!err)
2111 return outarg.revents;
2112 if (err == -ENOSYS) {
2113 fc->no_poll = 1;
2114 return DEFAULT_POLLMASK;
2115 }
2116 return POLLERR;
2117 }
2118 EXPORT_SYMBOL_GPL(fuse_file_poll);
2119
2120 /*
2121 * This is called from fuse_handle_notify() on FUSE_NOTIFY_POLL and
2122 * wakes up the poll waiters.
2123 */
2124 int fuse_notify_poll_wakeup(struct fuse_conn *fc,
2125 struct fuse_notify_poll_wakeup_out *outarg)
2126 {
2127 u64 kh = outarg->kh;
2128 struct rb_node **link;
2129
2130 spin_lock(&fc->lock);
2131
2132 link = fuse_find_polled_node(fc, kh, NULL);
2133 if (*link) {
2134 struct fuse_file *ff;
2135
2136 ff = rb_entry(*link, struct fuse_file, polled_node);
2137 wake_up_interruptible_sync(&ff->poll_wait);
2138 }
2139
2140 spin_unlock(&fc->lock);
2141 return 0;
2142 }
2143
2144 static const struct file_operations fuse_file_operations = {
2145 .llseek = fuse_file_llseek,
2146 .read = do_sync_read,
2147 .aio_read = fuse_file_aio_read,
2148 .write = do_sync_write,
2149 .aio_write = fuse_file_aio_write,
2150 .mmap = fuse_file_mmap,
2151 .open = fuse_open,
2152 .flush = fuse_flush,
2153 .release = fuse_release,
2154 .fsync = fuse_fsync,
2155 .lock = fuse_file_lock,
2156 .flock = fuse_file_flock,
2157 .splice_read = generic_file_splice_read,
2158 .unlocked_ioctl = fuse_file_ioctl,
2159 .compat_ioctl = fuse_file_compat_ioctl,
2160 .poll = fuse_file_poll,
2161 };
2162
2163 static const struct file_operations fuse_direct_io_file_operations = {
2164 .llseek = fuse_file_llseek,
2165 .read = fuse_direct_read,
2166 .write = fuse_direct_write,
2167 .mmap = fuse_direct_mmap,
2168 .open = fuse_open,
2169 .flush = fuse_flush,
2170 .release = fuse_release,
2171 .fsync = fuse_fsync,
2172 .lock = fuse_file_lock,
2173 .flock = fuse_file_flock,
2174 .unlocked_ioctl = fuse_file_ioctl,
2175 .compat_ioctl = fuse_file_compat_ioctl,
2176 .poll = fuse_file_poll,
2177 /* no splice_read */
2178 };
2179
2180 static const struct address_space_operations fuse_file_aops = {
2181 .readpage = fuse_readpage,
2182 .writepage = fuse_writepage,
2183 .launder_page = fuse_launder_page,
2184 .write_begin = fuse_write_begin,
2185 .write_end = fuse_write_end,
2186 .readpages = fuse_readpages,
2187 .set_page_dirty = __set_page_dirty_nobuffers,
2188 .bmap = fuse_bmap,
2189 };
2190
2191 void fuse_init_file_inode(struct inode *inode)
2192 {
2193 inode->i_fop = &fuse_file_operations;
2194 inode->i_data.a_ops = &fuse_file_aops;
2195 }
Linux kernel - Deliverables
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