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s390/pfault: add sanity check
[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 #include <linux/swap.h>
18
19 static const struct file_operations fuse_direct_io_file_operations;
20
21 static int fuse_send_open(struct fuse_conn *fc, u64 nodeid, struct file *file,
22 int opcode, struct fuse_open_out *outargp)
23 {
24 struct fuse_open_in inarg;
25 struct fuse_req *req;
26 int err;
27
28 req = fuse_get_req(fc);
29 if (IS_ERR(req))
30 return PTR_ERR(req);
31
32 memset(&inarg, 0, sizeof(inarg));
33 inarg.flags = file->f_flags & ~(O_CREAT | O_EXCL | O_NOCTTY);
34 if (!fc->atomic_o_trunc)
35 inarg.flags &= ~O_TRUNC;
36 req->in.h.opcode = opcode;
37 req->in.h.nodeid = nodeid;
38 req->in.numargs = 1;
39 req->in.args[0].size = sizeof(inarg);
40 req->in.args[0].value = &inarg;
41 req->out.numargs = 1;
42 req->out.args[0].size = sizeof(*outargp);
43 req->out.args[0].value = outargp;
44 fuse_request_send(fc, req);
45 err = req->out.h.error;
46 fuse_put_request(fc, req);
47
48 return err;
49 }
50
51 struct fuse_file *fuse_file_alloc(struct fuse_conn *fc)
52 {
53 struct fuse_file *ff;
54
55 ff = kmalloc(sizeof(struct fuse_file), GFP_KERNEL);
56 if (unlikely(!ff))
57 return NULL;
58
59 ff->fc = fc;
60 ff->reserved_req = fuse_request_alloc();
61 if (unlikely(!ff->reserved_req)) {
62 kfree(ff);
63 return NULL;
64 }
65
66 INIT_LIST_HEAD(&ff->write_entry);
67 atomic_set(&ff->count, 0);
68 RB_CLEAR_NODE(&ff->polled_node);
69 init_waitqueue_head(&ff->poll_wait);
70
71 spin_lock(&fc->lock);
72 ff->kh = ++fc->khctr;
73 spin_unlock(&fc->lock);
74
75 return ff;
76 }
77
78 void fuse_file_free(struct fuse_file *ff)
79 {
80 fuse_request_free(ff->reserved_req);
81 kfree(ff);
82 }
83
84 struct fuse_file *fuse_file_get(struct fuse_file *ff)
85 {
86 atomic_inc(&ff->count);
87 return ff;
88 }
89
90 static void fuse_release_async(struct work_struct *work)
91 {
92 struct fuse_req *req;
93 struct fuse_conn *fc;
94 struct path path;
95
96 req = container_of(work, struct fuse_req, misc.release.work);
97 path = req->misc.release.path;
98 fc = get_fuse_conn(path.dentry->d_inode);
99
100 fuse_put_request(fc, req);
101 path_put(&path);
102 }
103
104 static void fuse_release_end(struct fuse_conn *fc, struct fuse_req *req)
105 {
106 if (fc->destroy_req) {
107 /*
108 * If this is a fuseblk mount, then it's possible that
109 * releasing the path will result in releasing the
110 * super block and sending the DESTROY request. If
111 * the server is single threaded, this would hang.
112 * For this reason do the path_put() in a separate
113 * thread.
114 */
115 atomic_inc(&req->count);
116 INIT_WORK(&req->misc.release.work, fuse_release_async);
117 schedule_work(&req->misc.release.work);
118 } else {
119 path_put(&req->misc.release.path);
120 }
121 }
122
123 static void fuse_file_put(struct fuse_file *ff, bool sync)
124 {
125 if (atomic_dec_and_test(&ff->count)) {
126 struct fuse_req *req = ff->reserved_req;
127
128 if (sync) {
129 fuse_request_send(ff->fc, req);
130 path_put(&req->misc.release.path);
131 fuse_put_request(ff->fc, req);
132 } else {
133 req->end = fuse_release_end;
134 fuse_request_send_background(ff->fc, req);
135 }
136 kfree(ff);
137 }
138 }
139
140 int fuse_do_open(struct fuse_conn *fc, u64 nodeid, struct file *file,
141 bool isdir)
142 {
143 struct fuse_open_out outarg;
144 struct fuse_file *ff;
145 int err;
146 int opcode = isdir ? FUSE_OPENDIR : FUSE_OPEN;
147
148 ff = fuse_file_alloc(fc);
149 if (!ff)
150 return -ENOMEM;
151
152 err = fuse_send_open(fc, nodeid, file, opcode, &outarg);
153 if (err) {
154 fuse_file_free(ff);
155 return err;
156 }
157
158 if (isdir)
159 outarg.open_flags &= ~FOPEN_DIRECT_IO;
160
161 ff->fh = outarg.fh;
162 ff->nodeid = nodeid;
163 ff->open_flags = outarg.open_flags;
164 file->private_data = fuse_file_get(ff);
165
166 return 0;
167 }
168 EXPORT_SYMBOL_GPL(fuse_do_open);
169
170 void fuse_finish_open(struct inode *inode, struct file *file)
171 {
172 struct fuse_file *ff = file->private_data;
173 struct fuse_conn *fc = get_fuse_conn(inode);
174
175 if (ff->open_flags & FOPEN_DIRECT_IO)
176 file->f_op = &fuse_direct_io_file_operations;
177 if (!(ff->open_flags & FOPEN_KEEP_CACHE))
178 invalidate_inode_pages2(inode->i_mapping);
179 if (ff->open_flags & FOPEN_NONSEEKABLE)
180 nonseekable_open(inode, file);
181 if (fc->atomic_o_trunc && (file->f_flags & O_TRUNC)) {
182 struct fuse_inode *fi = get_fuse_inode(inode);
183
184 spin_lock(&fc->lock);
185 fi->attr_version = ++fc->attr_version;
186 i_size_write(inode, 0);
187 spin_unlock(&fc->lock);
188 fuse_invalidate_attr(inode);
189 }
190 }
191
192 int fuse_open_common(struct inode *inode, struct file *file, bool isdir)
193 {
194 struct fuse_conn *fc = get_fuse_conn(inode);
195 int err;
196
197 err = generic_file_open(inode, file);
198 if (err)
199 return err;
200
201 err = fuse_do_open(fc, get_node_id(inode), file, isdir);
202 if (err)
203 return err;
204
205 fuse_finish_open(inode, file);
206
207 return 0;
208 }
209
210 static void fuse_prepare_release(struct fuse_file *ff, int flags, int opcode)
211 {
212 struct fuse_conn *fc = ff->fc;
213 struct fuse_req *req = ff->reserved_req;
214 struct fuse_release_in *inarg = &req->misc.release.in;
215
216 spin_lock(&fc->lock);
217 list_del(&ff->write_entry);
218 if (!RB_EMPTY_NODE(&ff->polled_node))
219 rb_erase(&ff->polled_node, &fc->polled_files);
220 spin_unlock(&fc->lock);
221
222 wake_up_interruptible_all(&ff->poll_wait);
223
224 inarg->fh = ff->fh;
225 inarg->flags = flags;
226 req->in.h.opcode = opcode;
227 req->in.h.nodeid = ff->nodeid;
228 req->in.numargs = 1;
229 req->in.args[0].size = sizeof(struct fuse_release_in);
230 req->in.args[0].value = inarg;
231 }
232
233 void fuse_release_common(struct file *file, int opcode)
234 {
235 struct fuse_file *ff;
236 struct fuse_req *req;
237
238 ff = file->private_data;
239 if (unlikely(!ff))
240 return;
241
242 req = ff->reserved_req;
243 fuse_prepare_release(ff, file->f_flags, opcode);
244
245 if (ff->flock) {
246 struct fuse_release_in *inarg = &req->misc.release.in;
247 inarg->release_flags |= FUSE_RELEASE_FLOCK_UNLOCK;
248 inarg->lock_owner = fuse_lock_owner_id(ff->fc,
249 (fl_owner_t) file);
250 }
251 /* Hold vfsmount and dentry until release is finished */
252 path_get(&file->f_path);
253 req->misc.release.path = file->f_path;
254
255 /*
256 * Normally this will send the RELEASE request, however if
257 * some asynchronous READ or WRITE requests are outstanding,
258 * the sending will be delayed.
259 *
260 * Make the release synchronous if this is a fuseblk mount,
261 * synchronous RELEASE is allowed (and desirable) in this case
262 * because the server can be trusted not to screw up.
263 */
264 fuse_file_put(ff, ff->fc->destroy_req != NULL);
265 }
266
267 static int fuse_open(struct inode *inode, struct file *file)
268 {
269 return fuse_open_common(inode, file, false);
270 }
271
272 static int fuse_release(struct inode *inode, struct file *file)
273 {
274 fuse_release_common(file, FUSE_RELEASE);
275
276 /* return value is ignored by VFS */
277 return 0;
278 }
279
280 void fuse_sync_release(struct fuse_file *ff, int flags)
281 {
282 WARN_ON(atomic_read(&ff->count) > 1);
283 fuse_prepare_release(ff, flags, FUSE_RELEASE);
284 ff->reserved_req->force = 1;
285 fuse_request_send(ff->fc, ff->reserved_req);
286 fuse_put_request(ff->fc, ff->reserved_req);
287 kfree(ff);
288 }
289 EXPORT_SYMBOL_GPL(fuse_sync_release);
290
291 /*
292 * Scramble the ID space with XTEA, so that the value of the files_struct
293 * pointer is not exposed to userspace.
294 */
295 u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id)
296 {
297 u32 *k = fc->scramble_key;
298 u64 v = (unsigned long) id;
299 u32 v0 = v;
300 u32 v1 = v >> 32;
301 u32 sum = 0;
302 int i;
303
304 for (i = 0; i < 32; i++) {
305 v0 += ((v1 << 4 ^ v1 >> 5) + v1) ^ (sum + k[sum & 3]);
306 sum += 0x9E3779B9;
307 v1 += ((v0 << 4 ^ v0 >> 5) + v0) ^ (sum + k[sum>>11 & 3]);
308 }
309
310 return (u64) v0 + ((u64) v1 << 32);
311 }
312
313 /*
314 * Check if page is under writeback
315 *
316 * This is currently done by walking the list of writepage requests
317 * for the inode, which can be pretty inefficient.
318 */
319 static bool fuse_page_is_writeback(struct inode *inode, pgoff_t index)
320 {
321 struct fuse_conn *fc = get_fuse_conn(inode);
322 struct fuse_inode *fi = get_fuse_inode(inode);
323 struct fuse_req *req;
324 bool found = false;
325
326 spin_lock(&fc->lock);
327 list_for_each_entry(req, &fi->writepages, writepages_entry) {
328 pgoff_t curr_index;
329
330 BUG_ON(req->inode != inode);
331 curr_index = req->misc.write.in.offset >> PAGE_CACHE_SHIFT;
332 if (curr_index == index) {
333 found = true;
334 break;
335 }
336 }
337 spin_unlock(&fc->lock);
338
339 return found;
340 }
341
342 /*
343 * Wait for page writeback to be completed.
344 *
345 * Since fuse doesn't rely on the VM writeback tracking, this has to
346 * use some other means.
347 */
348 static int fuse_wait_on_page_writeback(struct inode *inode, pgoff_t index)
349 {
350 struct fuse_inode *fi = get_fuse_inode(inode);
351
352 wait_event(fi->page_waitq, !fuse_page_is_writeback(inode, index));
353 return 0;
354 }
355
356 static int fuse_flush(struct file *file, fl_owner_t id)
357 {
358 struct inode *inode = file->f_path.dentry->d_inode;
359 struct fuse_conn *fc = get_fuse_conn(inode);
360 struct fuse_file *ff = file->private_data;
361 struct fuse_req *req;
362 struct fuse_flush_in inarg;
363 int err;
364
365 if (is_bad_inode(inode))
366 return -EIO;
367
368 if (fc->no_flush)
369 return 0;
370
371 req = fuse_get_req_nofail(fc, file);
372 memset(&inarg, 0, sizeof(inarg));
373 inarg.fh = ff->fh;
374 inarg.lock_owner = fuse_lock_owner_id(fc, id);
375 req->in.h.opcode = FUSE_FLUSH;
376 req->in.h.nodeid = get_node_id(inode);
377 req->in.numargs = 1;
378 req->in.args[0].size = sizeof(inarg);
379 req->in.args[0].value = &inarg;
380 req->force = 1;
381 fuse_request_send(fc, req);
382 err = req->out.h.error;
383 fuse_put_request(fc, req);
384 if (err == -ENOSYS) {
385 fc->no_flush = 1;
386 err = 0;
387 }
388 return err;
389 }
390
391 /*
392 * Wait for all pending writepages on the inode to finish.
393 *
394 * This is currently done by blocking further writes with FUSE_NOWRITE
395 * and waiting for all sent writes to complete.
396 *
397 * This must be called under i_mutex, otherwise the FUSE_NOWRITE usage
398 * could conflict with truncation.
399 */
400 static void fuse_sync_writes(struct inode *inode)
401 {
402 fuse_set_nowrite(inode);
403 fuse_release_nowrite(inode);
404 }
405
406 int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
407 int datasync, int isdir)
408 {
409 struct inode *inode = file->f_mapping->host;
410 struct fuse_conn *fc = get_fuse_conn(inode);
411 struct fuse_file *ff = file->private_data;
412 struct fuse_req *req;
413 struct fuse_fsync_in inarg;
414 int err;
415
416 if (is_bad_inode(inode))
417 return -EIO;
418
419 err = filemap_write_and_wait_range(inode->i_mapping, start, end);
420 if (err)
421 return err;
422
423 if ((!isdir && fc->no_fsync) || (isdir && fc->no_fsyncdir))
424 return 0;
425
426 mutex_lock(&inode->i_mutex);
427
428 /*
429 * Start writeback against all dirty pages of the inode, then
430 * wait for all outstanding writes, before sending the FSYNC
431 * request.
432 */
433 err = write_inode_now(inode, 0);
434 if (err)
435 goto out;
436
437 fuse_sync_writes(inode);
438
439 req = fuse_get_req(fc);
440 if (IS_ERR(req)) {
441 err = PTR_ERR(req);
442 goto out;
443 }
444
445 memset(&inarg, 0, sizeof(inarg));
446 inarg.fh = ff->fh;
447 inarg.fsync_flags = datasync ? 1 : 0;
448 req->in.h.opcode = isdir ? FUSE_FSYNCDIR : FUSE_FSYNC;
449 req->in.h.nodeid = get_node_id(inode);
450 req->in.numargs = 1;
451 req->in.args[0].size = sizeof(inarg);
452 req->in.args[0].value = &inarg;
453 fuse_request_send(fc, req);
454 err = req->out.h.error;
455 fuse_put_request(fc, req);
456 if (err == -ENOSYS) {
457 if (isdir)
458 fc->no_fsyncdir = 1;
459 else
460 fc->no_fsync = 1;
461 err = 0;
462 }
463 out:
464 mutex_unlock(&inode->i_mutex);
465 return err;
466 }
467
468 static int fuse_fsync(struct file *file, loff_t start, loff_t end,
469 int datasync)
470 {
471 return fuse_fsync_common(file, start, end, datasync, 0);
472 }
473
474 void fuse_read_fill(struct fuse_req *req, struct file *file, loff_t pos,
475 size_t count, int opcode)
476 {
477 struct fuse_read_in *inarg = &req->misc.read.in;
478 struct fuse_file *ff = file->private_data;
479
480 inarg->fh = ff->fh;
481 inarg->offset = pos;
482 inarg->size = count;
483 inarg->flags = file->f_flags;
484 req->in.h.opcode = opcode;
485 req->in.h.nodeid = ff->nodeid;
486 req->in.numargs = 1;
487 req->in.args[0].size = sizeof(struct fuse_read_in);
488 req->in.args[0].value = inarg;
489 req->out.argvar = 1;
490 req->out.numargs = 1;
491 req->out.args[0].size = count;
492 }
493
494 static size_t fuse_send_read(struct fuse_req *req, struct file *file,
495 loff_t pos, size_t count, fl_owner_t owner)
496 {
497 struct fuse_file *ff = file->private_data;
498 struct fuse_conn *fc = ff->fc;
499
500 fuse_read_fill(req, file, pos, count, FUSE_READ);
501 if (owner != NULL) {
502 struct fuse_read_in *inarg = &req->misc.read.in;
503
504 inarg->read_flags |= FUSE_READ_LOCKOWNER;
505 inarg->lock_owner = fuse_lock_owner_id(fc, owner);
506 }
507 fuse_request_send(fc, req);
508 return req->out.args[0].size;
509 }
510
511 static void fuse_read_update_size(struct inode *inode, loff_t size,
512 u64 attr_ver)
513 {
514 struct fuse_conn *fc = get_fuse_conn(inode);
515 struct fuse_inode *fi = get_fuse_inode(inode);
516
517 spin_lock(&fc->lock);
518 if (attr_ver == fi->attr_version && size < inode->i_size) {
519 fi->attr_version = ++fc->attr_version;
520 i_size_write(inode, size);
521 }
522 spin_unlock(&fc->lock);
523 }
524
525 static int fuse_readpage(struct file *file, struct page *page)
526 {
527 struct inode *inode = page->mapping->host;
528 struct fuse_conn *fc = get_fuse_conn(inode);
529 struct fuse_req *req;
530 size_t num_read;
531 loff_t pos = page_offset(page);
532 size_t count = PAGE_CACHE_SIZE;
533 u64 attr_ver;
534 int err;
535
536 err = -EIO;
537 if (is_bad_inode(inode))
538 goto out;
539
540 /*
541 * Page writeback can extend beyond the lifetime of the
542 * page-cache page, so make sure we read a properly synced
543 * page.
544 */
545 fuse_wait_on_page_writeback(inode, page->index);
546
547 req = fuse_get_req(fc);
548 err = PTR_ERR(req);
549 if (IS_ERR(req))
550 goto out;
551
552 attr_ver = fuse_get_attr_version(fc);
553
554 req->out.page_zeroing = 1;
555 req->out.argpages = 1;
556 req->num_pages = 1;
557 req->pages[0] = page;
558 num_read = fuse_send_read(req, file, pos, count, NULL);
559 err = req->out.h.error;
560 fuse_put_request(fc, req);
561
562 if (!err) {
563 /*
564 * Short read means EOF. If file size is larger, truncate it
565 */
566 if (num_read < count)
567 fuse_read_update_size(inode, pos + num_read, attr_ver);
568
569 SetPageUptodate(page);
570 }
571
572 fuse_invalidate_attr(inode); /* atime changed */
573 out:
574 unlock_page(page);
575 return err;
576 }
577
578 static void fuse_readpages_end(struct fuse_conn *fc, struct fuse_req *req)
579 {
580 int i;
581 size_t count = req->misc.read.in.size;
582 size_t num_read = req->out.args[0].size;
583 struct address_space *mapping = NULL;
584
585 for (i = 0; mapping == NULL && i < req->num_pages; i++)
586 mapping = req->pages[i]->mapping;
587
588 if (mapping) {
589 struct inode *inode = mapping->host;
590
591 /*
592 * Short read means EOF. If file size is larger, truncate it
593 */
594 if (!req->out.h.error && num_read < count) {
595 loff_t pos;
596
597 pos = page_offset(req->pages[0]) + num_read;
598 fuse_read_update_size(inode, pos,
599 req->misc.read.attr_ver);
600 }
601 fuse_invalidate_attr(inode); /* atime changed */
602 }
603
604 for (i = 0; i < req->num_pages; i++) {
605 struct page *page = req->pages[i];
606 if (!req->out.h.error)
607 SetPageUptodate(page);
608 else
609 SetPageError(page);
610 unlock_page(page);
611 page_cache_release(page);
612 }
613 if (req->ff)
614 fuse_file_put(req->ff, false);
615 }
616
617 static void fuse_send_readpages(struct fuse_req *req, struct file *file)
618 {
619 struct fuse_file *ff = file->private_data;
620 struct fuse_conn *fc = ff->fc;
621 loff_t pos = page_offset(req->pages[0]);
622 size_t count = req->num_pages << PAGE_CACHE_SHIFT;
623
624 req->out.argpages = 1;
625 req->out.page_zeroing = 1;
626 req->out.page_replace = 1;
627 fuse_read_fill(req, file, pos, count, FUSE_READ);
628 req->misc.read.attr_ver = fuse_get_attr_version(fc);
629 if (fc->async_read) {
630 req->ff = fuse_file_get(ff);
631 req->end = fuse_readpages_end;
632 fuse_request_send_background(fc, req);
633 } else {
634 fuse_request_send(fc, req);
635 fuse_readpages_end(fc, req);
636 fuse_put_request(fc, req);
637 }
638 }
639
640 struct fuse_fill_data {
641 struct fuse_req *req;
642 struct file *file;
643 struct inode *inode;
644 };
645
646 static int fuse_readpages_fill(void *_data, struct page *page)
647 {
648 struct fuse_fill_data *data = _data;
649 struct fuse_req *req = data->req;
650 struct inode *inode = data->inode;
651 struct fuse_conn *fc = get_fuse_conn(inode);
652
653 fuse_wait_on_page_writeback(inode, page->index);
654
655 if (req->num_pages &&
656 (req->num_pages == FUSE_MAX_PAGES_PER_REQ ||
657 (req->num_pages + 1) * PAGE_CACHE_SIZE > fc->max_read ||
658 req->pages[req->num_pages - 1]->index + 1 != page->index)) {
659 fuse_send_readpages(req, data->file);
660 data->req = req = fuse_get_req(fc);
661 if (IS_ERR(req)) {
662 unlock_page(page);
663 return PTR_ERR(req);
664 }
665 }
666 page_cache_get(page);
667 req->pages[req->num_pages] = page;
668 req->num_pages++;
669 return 0;
670 }
671
672 static int fuse_readpages(struct file *file, struct address_space *mapping,
673 struct list_head *pages, unsigned nr_pages)
674 {
675 struct inode *inode = mapping->host;
676 struct fuse_conn *fc = get_fuse_conn(inode);
677 struct fuse_fill_data data;
678 int err;
679
680 err = -EIO;
681 if (is_bad_inode(inode))
682 goto out;
683
684 data.file = file;
685 data.inode = inode;
686 data.req = fuse_get_req(fc);
687 err = PTR_ERR(data.req);
688 if (IS_ERR(data.req))
689 goto out;
690
691 err = read_cache_pages(mapping, pages, fuse_readpages_fill, &data);
692 if (!err) {
693 if (data.req->num_pages)
694 fuse_send_readpages(data.req, file);
695 else
696 fuse_put_request(fc, data.req);
697 }
698 out:
699 return err;
700 }
701
702 static ssize_t fuse_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
703 unsigned long nr_segs, loff_t pos)
704 {
705 struct inode *inode = iocb->ki_filp->f_mapping->host;
706
707 if (pos + iov_length(iov, nr_segs) > i_size_read(inode)) {
708 int err;
709 /*
710 * If trying to read past EOF, make sure the i_size
711 * attribute is up-to-date.
712 */
713 err = fuse_update_attributes(inode, NULL, iocb->ki_filp, NULL);
714 if (err)
715 return err;
716 }
717
718 return generic_file_aio_read(iocb, iov, nr_segs, pos);
719 }
720
721 static void fuse_write_fill(struct fuse_req *req, struct fuse_file *ff,
722 loff_t pos, size_t count)
723 {
724 struct fuse_write_in *inarg = &req->misc.write.in;
725 struct fuse_write_out *outarg = &req->misc.write.out;
726
727 inarg->fh = ff->fh;
728 inarg->offset = pos;
729 inarg->size = count;
730 req->in.h.opcode = FUSE_WRITE;
731 req->in.h.nodeid = ff->nodeid;
732 req->in.numargs = 2;
733 if (ff->fc->minor < 9)
734 req->in.args[0].size = FUSE_COMPAT_WRITE_IN_SIZE;
735 else
736 req->in.args[0].size = sizeof(struct fuse_write_in);
737 req->in.args[0].value = inarg;
738 req->in.args[1].size = count;
739 req->out.numargs = 1;
740 req->out.args[0].size = sizeof(struct fuse_write_out);
741 req->out.args[0].value = outarg;
742 }
743
744 static size_t fuse_send_write(struct fuse_req *req, struct file *file,
745 loff_t pos, size_t count, fl_owner_t owner)
746 {
747 struct fuse_file *ff = file->private_data;
748 struct fuse_conn *fc = ff->fc;
749 struct fuse_write_in *inarg = &req->misc.write.in;
750
751 fuse_write_fill(req, ff, pos, count);
752 inarg->flags = file->f_flags;
753 if (owner != NULL) {
754 inarg->write_flags |= FUSE_WRITE_LOCKOWNER;
755 inarg->lock_owner = fuse_lock_owner_id(fc, owner);
756 }
757 fuse_request_send(fc, req);
758 return req->misc.write.out.size;
759 }
760
761 void fuse_write_update_size(struct inode *inode, loff_t pos)
762 {
763 struct fuse_conn *fc = get_fuse_conn(inode);
764 struct fuse_inode *fi = get_fuse_inode(inode);
765
766 spin_lock(&fc->lock);
767 fi->attr_version = ++fc->attr_version;
768 if (pos > inode->i_size)
769 i_size_write(inode, pos);
770 spin_unlock(&fc->lock);
771 }
772
773 static size_t fuse_send_write_pages(struct fuse_req *req, struct file *file,
774 struct inode *inode, loff_t pos,
775 size_t count)
776 {
777 size_t res;
778 unsigned offset;
779 unsigned i;
780
781 for (i = 0; i < req->num_pages; i++)
782 fuse_wait_on_page_writeback(inode, req->pages[i]->index);
783
784 res = fuse_send_write(req, file, pos, count, NULL);
785
786 offset = req->page_offset;
787 count = res;
788 for (i = 0; i < req->num_pages; i++) {
789 struct page *page = req->pages[i];
790
791 if (!req->out.h.error && !offset && count >= PAGE_CACHE_SIZE)
792 SetPageUptodate(page);
793
794 if (count > PAGE_CACHE_SIZE - offset)
795 count -= PAGE_CACHE_SIZE - offset;
796 else
797 count = 0;
798 offset = 0;
799
800 unlock_page(page);
801 page_cache_release(page);
802 }
803
804 return res;
805 }
806
807 static ssize_t fuse_fill_write_pages(struct fuse_req *req,
808 struct address_space *mapping,
809 struct iov_iter *ii, loff_t pos)
810 {
811 struct fuse_conn *fc = get_fuse_conn(mapping->host);
812 unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
813 size_t count = 0;
814 int err;
815
816 req->in.argpages = 1;
817 req->page_offset = offset;
818
819 do {
820 size_t tmp;
821 struct page *page;
822 pgoff_t index = pos >> PAGE_CACHE_SHIFT;
823 size_t bytes = min_t(size_t, PAGE_CACHE_SIZE - offset,
824 iov_iter_count(ii));
825
826 bytes = min_t(size_t, bytes, fc->max_write - count);
827
828 again:
829 err = -EFAULT;
830 if (iov_iter_fault_in_readable(ii, bytes))
831 break;
832
833 err = -ENOMEM;
834 page = grab_cache_page_write_begin(mapping, index, 0);
835 if (!page)
836 break;
837
838 if (mapping_writably_mapped(mapping))
839 flush_dcache_page(page);
840
841 pagefault_disable();
842 tmp = iov_iter_copy_from_user_atomic(page, ii, offset, bytes);
843 pagefault_enable();
844 flush_dcache_page(page);
845
846 mark_page_accessed(page);
847
848 if (!tmp) {
849 unlock_page(page);
850 page_cache_release(page);
851 bytes = min(bytes, iov_iter_single_seg_count(ii));
852 goto again;
853 }
854
855 err = 0;
856 req->pages[req->num_pages] = page;
857 req->num_pages++;
858
859 iov_iter_advance(ii, tmp);
860 count += tmp;
861 pos += tmp;
862 offset += tmp;
863 if (offset == PAGE_CACHE_SIZE)
864 offset = 0;
865
866 if (!fc->big_writes)
867 break;
868 } while (iov_iter_count(ii) && count < fc->max_write &&
869 req->num_pages < FUSE_MAX_PAGES_PER_REQ && offset == 0);
870
871 return count > 0 ? count : err;
872 }
873
874 static ssize_t fuse_perform_write(struct file *file,
875 struct address_space *mapping,
876 struct iov_iter *ii, loff_t pos)
877 {
878 struct inode *inode = mapping->host;
879 struct fuse_conn *fc = get_fuse_conn(inode);
880 int err = 0;
881 ssize_t res = 0;
882
883 if (is_bad_inode(inode))
884 return -EIO;
885
886 do {
887 struct fuse_req *req;
888 ssize_t count;
889
890 req = fuse_get_req(fc);
891 if (IS_ERR(req)) {
892 err = PTR_ERR(req);
893 break;
894 }
895
896 count = fuse_fill_write_pages(req, mapping, ii, pos);
897 if (count <= 0) {
898 err = count;
899 } else {
900 size_t num_written;
901
902 num_written = fuse_send_write_pages(req, file, inode,
903 pos, count);
904 err = req->out.h.error;
905 if (!err) {
906 res += num_written;
907 pos += num_written;
908
909 /* break out of the loop on short write */
910 if (num_written != count)
911 err = -EIO;
912 }
913 }
914 fuse_put_request(fc, req);
915 } while (!err && iov_iter_count(ii));
916
917 if (res > 0)
918 fuse_write_update_size(inode, pos);
919
920 fuse_invalidate_attr(inode);
921
922 return res > 0 ? res : err;
923 }
924
925 static ssize_t fuse_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
926 unsigned long nr_segs, loff_t pos)
927 {
928 struct file *file = iocb->ki_filp;
929 struct address_space *mapping = file->f_mapping;
930 size_t count = 0;
931 size_t ocount = 0;
932 ssize_t written = 0;
933 ssize_t written_buffered = 0;
934 struct inode *inode = mapping->host;
935 ssize_t err;
936 struct iov_iter i;
937 loff_t endbyte = 0;
938
939 WARN_ON(iocb->ki_pos != pos);
940
941 ocount = 0;
942 err = generic_segment_checks(iov, &nr_segs, &ocount, VERIFY_READ);
943 if (err)
944 return err;
945
946 count = ocount;
947
948 mutex_lock(&inode->i_mutex);
949 vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
950
951 /* We can write back this queue in page reclaim */
952 current->backing_dev_info = mapping->backing_dev_info;
953
954 err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
955 if (err)
956 goto out;
957
958 if (count == 0)
959 goto out;
960
961 err = file_remove_suid(file);
962 if (err)
963 goto out;
964
965 file_update_time(file);
966
967 if (file->f_flags & O_DIRECT) {
968 written = generic_file_direct_write(iocb, iov, &nr_segs,
969 pos, &iocb->ki_pos,
970 count, ocount);
971 if (written < 0 || written == count)
972 goto out;
973
974 pos += written;
975 count -= written;
976
977 iov_iter_init(&i, iov, nr_segs, count, written);
978 written_buffered = fuse_perform_write(file, mapping, &i, pos);
979 if (written_buffered < 0) {
980 err = written_buffered;
981 goto out;
982 }
983 endbyte = pos + written_buffered - 1;
984
985 err = filemap_write_and_wait_range(file->f_mapping, pos,
986 endbyte);
987 if (err)
988 goto out;
989
990 invalidate_mapping_pages(file->f_mapping,
991 pos >> PAGE_CACHE_SHIFT,
992 endbyte >> PAGE_CACHE_SHIFT);
993
994 written += written_buffered;
995 iocb->ki_pos = pos + written_buffered;
996 } else {
997 iov_iter_init(&i, iov, nr_segs, count, 0);
998 written = fuse_perform_write(file, mapping, &i, pos);
999 if (written >= 0)
1000 iocb->ki_pos = pos + written;
1001 }
1002 out:
1003 current->backing_dev_info = NULL;
1004 mutex_unlock(&inode->i_mutex);
1005
1006 return written ? written : err;
1007 }
1008
1009 static void fuse_release_user_pages(struct fuse_req *req, int write)
1010 {
1011 unsigned i;
1012
1013 for (i = 0; i < req->num_pages; i++) {
1014 struct page *page = req->pages[i];
1015 if (write)
1016 set_page_dirty_lock(page);
1017 put_page(page);
1018 }
1019 }
1020
1021 static int fuse_get_user_pages(struct fuse_req *req, const char __user *buf,
1022 size_t *nbytesp, int write)
1023 {
1024 size_t nbytes = *nbytesp;
1025 unsigned long user_addr = (unsigned long) buf;
1026 unsigned offset = user_addr & ~PAGE_MASK;
1027 int npages;
1028
1029 /* Special case for kernel I/O: can copy directly into the buffer */
1030 if (segment_eq(get_fs(), KERNEL_DS)) {
1031 if (write)
1032 req->in.args[1].value = (void *) user_addr;
1033 else
1034 req->out.args[0].value = (void *) user_addr;
1035
1036 return 0;
1037 }
1038
1039 nbytes = min_t(size_t, nbytes, FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT);
1040 npages = (nbytes + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
1041 npages = clamp(npages, 1, FUSE_MAX_PAGES_PER_REQ);
1042 npages = get_user_pages_fast(user_addr, npages, !write, req->pages);
1043 if (npages < 0)
1044 return npages;
1045
1046 req->num_pages = npages;
1047 req->page_offset = offset;
1048
1049 if (write)
1050 req->in.argpages = 1;
1051 else
1052 req->out.argpages = 1;
1053
1054 nbytes = (req->num_pages << PAGE_SHIFT) - req->page_offset;
1055 *nbytesp = min(*nbytesp, nbytes);
1056
1057 return 0;
1058 }
1059
1060 ssize_t fuse_direct_io(struct file *file, const char __user *buf,
1061 size_t count, loff_t *ppos, int write)
1062 {
1063 struct fuse_file *ff = file->private_data;
1064 struct fuse_conn *fc = ff->fc;
1065 size_t nmax = write ? fc->max_write : fc->max_read;
1066 loff_t pos = *ppos;
1067 ssize_t res = 0;
1068 struct fuse_req *req;
1069
1070 req = fuse_get_req(fc);
1071 if (IS_ERR(req))
1072 return PTR_ERR(req);
1073
1074 while (count) {
1075 size_t nres;
1076 fl_owner_t owner = current->files;
1077 size_t nbytes = min(count, nmax);
1078 int err = fuse_get_user_pages(req, buf, &nbytes, write);
1079 if (err) {
1080 res = err;
1081 break;
1082 }
1083
1084 if (write)
1085 nres = fuse_send_write(req, file, pos, nbytes, owner);
1086 else
1087 nres = fuse_send_read(req, file, pos, nbytes, owner);
1088
1089 fuse_release_user_pages(req, !write);
1090 if (req->out.h.error) {
1091 if (!res)
1092 res = req->out.h.error;
1093 break;
1094 } else if (nres > nbytes) {
1095 res = -EIO;
1096 break;
1097 }
1098 count -= nres;
1099 res += nres;
1100 pos += nres;
1101 buf += nres;
1102 if (nres != nbytes)
1103 break;
1104 if (count) {
1105 fuse_put_request(fc, req);
1106 req = fuse_get_req(fc);
1107 if (IS_ERR(req))
1108 break;
1109 }
1110 }
1111 if (!IS_ERR(req))
1112 fuse_put_request(fc, req);
1113 if (res > 0)
1114 *ppos = pos;
1115
1116 return res;
1117 }
1118 EXPORT_SYMBOL_GPL(fuse_direct_io);
1119
1120 static ssize_t fuse_direct_read(struct file *file, char __user *buf,
1121 size_t count, loff_t *ppos)
1122 {
1123 ssize_t res;
1124 struct inode *inode = file->f_path.dentry->d_inode;
1125
1126 if (is_bad_inode(inode))
1127 return -EIO;
1128
1129 res = fuse_direct_io(file, buf, count, ppos, 0);
1130
1131 fuse_invalidate_attr(inode);
1132
1133 return res;
1134 }
1135
1136 static ssize_t __fuse_direct_write(struct file *file, const char __user *buf,
1137 size_t count, loff_t *ppos)
1138 {
1139 struct inode *inode = file->f_path.dentry->d_inode;
1140 ssize_t res;
1141
1142 res = generic_write_checks(file, ppos, &count, 0);
1143 if (!res) {
1144 res = fuse_direct_io(file, buf, count, ppos, 1);
1145 if (res > 0)
1146 fuse_write_update_size(inode, *ppos);
1147 }
1148
1149 fuse_invalidate_attr(inode);
1150
1151 return res;
1152 }
1153
1154 static ssize_t fuse_direct_write(struct file *file, const char __user *buf,
1155 size_t count, loff_t *ppos)
1156 {
1157 struct inode *inode = file->f_path.dentry->d_inode;
1158 ssize_t res;
1159
1160 if (is_bad_inode(inode))
1161 return -EIO;
1162
1163 /* Don't allow parallel writes to the same file */
1164 mutex_lock(&inode->i_mutex);
1165 res = __fuse_direct_write(file, buf, count, ppos);
1166 mutex_unlock(&inode->i_mutex);
1167
1168 return res;
1169 }
1170
1171 static void fuse_writepage_free(struct fuse_conn *fc, struct fuse_req *req)
1172 {
1173 __free_page(req->pages[0]);
1174 fuse_file_put(req->ff, false);
1175 }
1176
1177 static void fuse_writepage_finish(struct fuse_conn *fc, struct fuse_req *req)
1178 {
1179 struct inode *inode = req->inode;
1180 struct fuse_inode *fi = get_fuse_inode(inode);
1181 struct backing_dev_info *bdi = inode->i_mapping->backing_dev_info;
1182
1183 list_del(&req->writepages_entry);
1184 dec_bdi_stat(bdi, BDI_WRITEBACK);
1185 dec_zone_page_state(req->pages[0], NR_WRITEBACK_TEMP);
1186 bdi_writeout_inc(bdi);
1187 wake_up(&fi->page_waitq);
1188 }
1189
1190 /* Called under fc->lock, may release and reacquire it */
1191 static void fuse_send_writepage(struct fuse_conn *fc, struct fuse_req *req)
1192 __releases(fc->lock)
1193 __acquires(fc->lock)
1194 {
1195 struct fuse_inode *fi = get_fuse_inode(req->inode);
1196 loff_t size = i_size_read(req->inode);
1197 struct fuse_write_in *inarg = &req->misc.write.in;
1198
1199 if (!fc->connected)
1200 goto out_free;
1201
1202 if (inarg->offset + PAGE_CACHE_SIZE <= size) {
1203 inarg->size = PAGE_CACHE_SIZE;
1204 } else if (inarg->offset < size) {
1205 inarg->size = size & (PAGE_CACHE_SIZE - 1);
1206 } else {
1207 /* Got truncated off completely */
1208 goto out_free;
1209 }
1210
1211 req->in.args[1].size = inarg->size;
1212 fi->writectr++;
1213 fuse_request_send_background_locked(fc, req);
1214 return;
1215
1216 out_free:
1217 fuse_writepage_finish(fc, req);
1218 spin_unlock(&fc->lock);
1219 fuse_writepage_free(fc, req);
1220 fuse_put_request(fc, req);
1221 spin_lock(&fc->lock);
1222 }
1223
1224 /*
1225 * If fi->writectr is positive (no truncate or fsync going on) send
1226 * all queued writepage requests.
1227 *
1228 * Called with fc->lock
1229 */
1230 void fuse_flush_writepages(struct inode *inode)
1231 __releases(fc->lock)
1232 __acquires(fc->lock)
1233 {
1234 struct fuse_conn *fc = get_fuse_conn(inode);
1235 struct fuse_inode *fi = get_fuse_inode(inode);
1236 struct fuse_req *req;
1237
1238 while (fi->writectr >= 0 && !list_empty(&fi->queued_writes)) {
1239 req = list_entry(fi->queued_writes.next, struct fuse_req, list);
1240 list_del_init(&req->list);
1241 fuse_send_writepage(fc, req);
1242 }
1243 }
1244
1245 static void fuse_writepage_end(struct fuse_conn *fc, struct fuse_req *req)
1246 {
1247 struct inode *inode = req->inode;
1248 struct fuse_inode *fi = get_fuse_inode(inode);
1249
1250 mapping_set_error(inode->i_mapping, req->out.h.error);
1251 spin_lock(&fc->lock);
1252 fi->writectr--;
1253 fuse_writepage_finish(fc, req);
1254 spin_unlock(&fc->lock);
1255 fuse_writepage_free(fc, req);
1256 }
1257
1258 static int fuse_writepage_locked(struct page *page)
1259 {
1260 struct address_space *mapping = page->mapping;
1261 struct inode *inode = mapping->host;
1262 struct fuse_conn *fc = get_fuse_conn(inode);
1263 struct fuse_inode *fi = get_fuse_inode(inode);
1264 struct fuse_req *req;
1265 struct fuse_file *ff;
1266 struct page *tmp_page;
1267
1268 set_page_writeback(page);
1269
1270 req = fuse_request_alloc_nofs();
1271 if (!req)
1272 goto err;
1273
1274 tmp_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
1275 if (!tmp_page)
1276 goto err_free;
1277
1278 spin_lock(&fc->lock);
1279 BUG_ON(list_empty(&fi->write_files));
1280 ff = list_entry(fi->write_files.next, struct fuse_file, write_entry);
1281 req->ff = fuse_file_get(ff);
1282 spin_unlock(&fc->lock);
1283
1284 fuse_write_fill(req, ff, page_offset(page), 0);
1285
1286 copy_highpage(tmp_page, page);
1287 req->misc.write.in.write_flags |= FUSE_WRITE_CACHE;
1288 req->in.argpages = 1;
1289 req->num_pages = 1;
1290 req->pages[0] = tmp_page;
1291 req->page_offset = 0;
1292 req->end = fuse_writepage_end;
1293 req->inode = inode;
1294
1295 inc_bdi_stat(mapping->backing_dev_info, BDI_WRITEBACK);
1296 inc_zone_page_state(tmp_page, NR_WRITEBACK_TEMP);
1297 end_page_writeback(page);
1298
1299 spin_lock(&fc->lock);
1300 list_add(&req->writepages_entry, &fi->writepages);
1301 list_add_tail(&req->list, &fi->queued_writes);
1302 fuse_flush_writepages(inode);
1303 spin_unlock(&fc->lock);
1304
1305 return 0;
1306
1307 err_free:
1308 fuse_request_free(req);
1309 err:
1310 end_page_writeback(page);
1311 return -ENOMEM;
1312 }
1313
1314 static int fuse_writepage(struct page *page, struct writeback_control *wbc)
1315 {
1316 int err;
1317
1318 err = fuse_writepage_locked(page);
1319 unlock_page(page);
1320
1321 return err;
1322 }
1323
1324 static int fuse_launder_page(struct page *page)
1325 {
1326 int err = 0;
1327 if (clear_page_dirty_for_io(page)) {
1328 struct inode *inode = page->mapping->host;
1329 err = fuse_writepage_locked(page);
1330 if (!err)
1331 fuse_wait_on_page_writeback(inode, page->index);
1332 }
1333 return err;
1334 }
1335
1336 /*
1337 * Write back dirty pages now, because there may not be any suitable
1338 * open files later
1339 */
1340 static void fuse_vma_close(struct vm_area_struct *vma)
1341 {
1342 filemap_write_and_wait(vma->vm_file->f_mapping);
1343 }
1344
1345 /*
1346 * Wait for writeback against this page to complete before allowing it
1347 * to be marked dirty again, and hence written back again, possibly
1348 * before the previous writepage completed.
1349 *
1350 * Block here, instead of in ->writepage(), so that the userspace fs
1351 * can only block processes actually operating on the filesystem.
1352 *
1353 * Otherwise unprivileged userspace fs would be able to block
1354 * unrelated:
1355 *
1356 * - page migration
1357 * - sync(2)
1358 * - try_to_free_pages() with order > PAGE_ALLOC_COSTLY_ORDER
1359 */
1360 static int fuse_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
1361 {
1362 struct page *page = vmf->page;
1363 /*
1364 * Don't use page->mapping as it may become NULL from a
1365 * concurrent truncate.
1366 */
1367 struct inode *inode = vma->vm_file->f_mapping->host;
1368
1369 fuse_wait_on_page_writeback(inode, page->index);
1370 return 0;
1371 }
1372
1373 static const struct vm_operations_struct fuse_file_vm_ops = {
1374 .close = fuse_vma_close,
1375 .fault = filemap_fault,
1376 .page_mkwrite = fuse_page_mkwrite,
1377 };
1378
1379 static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma)
1380 {
1381 if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_MAYWRITE)) {
1382 struct inode *inode = file->f_dentry->d_inode;
1383 struct fuse_conn *fc = get_fuse_conn(inode);
1384 struct fuse_inode *fi = get_fuse_inode(inode);
1385 struct fuse_file *ff = file->private_data;
1386 /*
1387 * file may be written through mmap, so chain it onto the
1388 * inodes's write_file list
1389 */
1390 spin_lock(&fc->lock);
1391 if (list_empty(&ff->write_entry))
1392 list_add(&ff->write_entry, &fi->write_files);
1393 spin_unlock(&fc->lock);
1394 }
1395 file_accessed(file);
1396 vma->vm_ops = &fuse_file_vm_ops;
1397 return 0;
1398 }
1399
1400 static int fuse_direct_mmap(struct file *file, struct vm_area_struct *vma)
1401 {
1402 /* Can't provide the coherency needed for MAP_SHARED */
1403 if (vma->vm_flags & VM_MAYSHARE)
1404 return -ENODEV;
1405
1406 invalidate_inode_pages2(file->f_mapping);
1407
1408 return generic_file_mmap(file, vma);
1409 }
1410
1411 static int convert_fuse_file_lock(const struct fuse_file_lock *ffl,
1412 struct file_lock *fl)
1413 {
1414 switch (ffl->type) {
1415 case F_UNLCK:
1416 break;
1417
1418 case F_RDLCK:
1419 case F_WRLCK:
1420 if (ffl->start > OFFSET_MAX || ffl->end > OFFSET_MAX ||
1421 ffl->end < ffl->start)
1422 return -EIO;
1423
1424 fl->fl_start = ffl->start;
1425 fl->fl_end = ffl->end;
1426 fl->fl_pid = ffl->pid;
1427 break;
1428
1429 default:
1430 return -EIO;
1431 }
1432 fl->fl_type = ffl->type;
1433 return 0;
1434 }
1435
1436 static void fuse_lk_fill(struct fuse_req *req, struct file *file,
1437 const struct file_lock *fl, int opcode, pid_t pid,
1438 int flock)
1439 {
1440 struct inode *inode = file->f_path.dentry->d_inode;
1441 struct fuse_conn *fc = get_fuse_conn(inode);
1442 struct fuse_file *ff = file->private_data;
1443 struct fuse_lk_in *arg = &req->misc.lk_in;
1444
1445 arg->fh = ff->fh;
1446 arg->owner = fuse_lock_owner_id(fc, fl->fl_owner);
1447 arg->lk.start = fl->fl_start;
1448 arg->lk.end = fl->fl_end;
1449 arg->lk.type = fl->fl_type;
1450 arg->lk.pid = pid;
1451 if (flock)
1452 arg->lk_flags |= FUSE_LK_FLOCK;
1453 req->in.h.opcode = opcode;
1454 req->in.h.nodeid = get_node_id(inode);
1455 req->in.numargs = 1;
1456 req->in.args[0].size = sizeof(*arg);
1457 req->in.args[0].value = arg;
1458 }
1459
1460 static int fuse_getlk(struct file *file, struct file_lock *fl)
1461 {
1462 struct inode *inode = file->f_path.dentry->d_inode;
1463 struct fuse_conn *fc = get_fuse_conn(inode);
1464 struct fuse_req *req;
1465 struct fuse_lk_out outarg;
1466 int err;
1467
1468 req = fuse_get_req(fc);
1469 if (IS_ERR(req))
1470 return PTR_ERR(req);
1471
1472 fuse_lk_fill(req, file, fl, FUSE_GETLK, 0, 0);
1473 req->out.numargs = 1;
1474 req->out.args[0].size = sizeof(outarg);
1475 req->out.args[0].value = &outarg;
1476 fuse_request_send(fc, req);
1477 err = req->out.h.error;
1478 fuse_put_request(fc, req);
1479 if (!err)
1480 err = convert_fuse_file_lock(&outarg.lk, fl);
1481
1482 return err;
1483 }
1484
1485 static int fuse_setlk(struct file *file, struct file_lock *fl, int flock)
1486 {
1487 struct inode *inode = file->f_path.dentry->d_inode;
1488 struct fuse_conn *fc = get_fuse_conn(inode);
1489 struct fuse_req *req;
1490 int opcode = (fl->fl_flags & FL_SLEEP) ? FUSE_SETLKW : FUSE_SETLK;
1491 pid_t pid = fl->fl_type != F_UNLCK ? current->tgid : 0;
1492 int err;
1493
1494 if (fl->fl_lmops && fl->fl_lmops->lm_grant) {
1495 /* NLM needs asynchronous locks, which we don't support yet */
1496 return -ENOLCK;
1497 }
1498
1499 /* Unlock on close is handled by the flush method */
1500 if (fl->fl_flags & FL_CLOSE)
1501 return 0;
1502
1503 req = fuse_get_req(fc);
1504 if (IS_ERR(req))
1505 return PTR_ERR(req);
1506
1507 fuse_lk_fill(req, file, fl, opcode, pid, flock);
1508 fuse_request_send(fc, req);
1509 err = req->out.h.error;
1510 /* locking is restartable */
1511 if (err == -EINTR)
1512 err = -ERESTARTSYS;
1513 fuse_put_request(fc, req);
1514 return err;
1515 }
1516
1517 static int fuse_file_lock(struct file *file, int cmd, struct file_lock *fl)
1518 {
1519 struct inode *inode = file->f_path.dentry->d_inode;
1520 struct fuse_conn *fc = get_fuse_conn(inode);
1521 int err;
1522
1523 if (cmd == F_CANCELLK) {
1524 err = 0;
1525 } else if (cmd == F_GETLK) {
1526 if (fc->no_lock) {
1527 posix_test_lock(file, fl);
1528 err = 0;
1529 } else
1530 err = fuse_getlk(file, fl);
1531 } else {
1532 if (fc->no_lock)
1533 err = posix_lock_file(file, fl, NULL);
1534 else
1535 err = fuse_setlk(file, fl, 0);
1536 }
1537 return err;
1538 }
1539
1540 static int fuse_file_flock(struct file *file, int cmd, struct file_lock *fl)
1541 {
1542 struct inode *inode = file->f_path.dentry->d_inode;
1543 struct fuse_conn *fc = get_fuse_conn(inode);
1544 int err;
1545
1546 if (fc->no_flock) {
1547 err = flock_lock_file_wait(file, fl);
1548 } else {
1549 struct fuse_file *ff = file->private_data;
1550
1551 /* emulate flock with POSIX locks */
1552 fl->fl_owner = (fl_owner_t) file;
1553 ff->flock = true;
1554 err = fuse_setlk(file, fl, 1);
1555 }
1556
1557 return err;
1558 }
1559
1560 static sector_t fuse_bmap(struct address_space *mapping, sector_t block)
1561 {
1562 struct inode *inode = mapping->host;
1563 struct fuse_conn *fc = get_fuse_conn(inode);
1564 struct fuse_req *req;
1565 struct fuse_bmap_in inarg;
1566 struct fuse_bmap_out outarg;
1567 int err;
1568
1569 if (!inode->i_sb->s_bdev || fc->no_bmap)
1570 return 0;
1571
1572 req = fuse_get_req(fc);
1573 if (IS_ERR(req))
1574 return 0;
1575
1576 memset(&inarg, 0, sizeof(inarg));
1577 inarg.block = block;
1578 inarg.blocksize = inode->i_sb->s_blocksize;
1579 req->in.h.opcode = FUSE_BMAP;
1580 req->in.h.nodeid = get_node_id(inode);
1581 req->in.numargs = 1;
1582 req->in.args[0].size = sizeof(inarg);
1583 req->in.args[0].value = &inarg;
1584 req->out.numargs = 1;
1585 req->out.args[0].size = sizeof(outarg);
1586 req->out.args[0].value = &outarg;
1587 fuse_request_send(fc, req);
1588 err = req->out.h.error;
1589 fuse_put_request(fc, req);
1590 if (err == -ENOSYS)
1591 fc->no_bmap = 1;
1592
1593 return err ? 0 : outarg.block;
1594 }
1595
1596 static loff_t fuse_file_llseek(struct file *file, loff_t offset, int origin)
1597 {
1598 loff_t retval;
1599 struct inode *inode = file->f_path.dentry->d_inode;
1600
1601 /* No i_mutex protection necessary for SEEK_CUR and SEEK_SET */
1602 if (origin == SEEK_CUR || origin == SEEK_SET)
1603 return generic_file_llseek(file, offset, origin);
1604
1605 mutex_lock(&inode->i_mutex);
1606 retval = fuse_update_attributes(inode, NULL, file, NULL);
1607 if (!retval)
1608 retval = generic_file_llseek(file, offset, origin);
1609 mutex_unlock(&inode->i_mutex);
1610
1611 return retval;
1612 }
1613
1614 static int fuse_ioctl_copy_user(struct page **pages, struct iovec *iov,
1615 unsigned int nr_segs, size_t bytes, bool to_user)
1616 {
1617 struct iov_iter ii;
1618 int page_idx = 0;
1619
1620 if (!bytes)
1621 return 0;
1622
1623 iov_iter_init(&ii, iov, nr_segs, bytes, 0);
1624
1625 while (iov_iter_count(&ii)) {
1626 struct page *page = pages[page_idx++];
1627 size_t todo = min_t(size_t, PAGE_SIZE, iov_iter_count(&ii));
1628 void *kaddr;
1629
1630 kaddr = kmap(page);
1631
1632 while (todo) {
1633 char __user *uaddr = ii.iov->iov_base + ii.iov_offset;
1634 size_t iov_len = ii.iov->iov_len - ii.iov_offset;
1635 size_t copy = min(todo, iov_len);
1636 size_t left;
1637
1638 if (!to_user)
1639 left = copy_from_user(kaddr, uaddr, copy);
1640 else
1641 left = copy_to_user(uaddr, kaddr, copy);
1642
1643 if (unlikely(left))
1644 return -EFAULT;
1645
1646 iov_iter_advance(&ii, copy);
1647 todo -= copy;
1648 kaddr += copy;
1649 }
1650
1651 kunmap(page);
1652 }
1653
1654 return 0;
1655 }
1656
1657 /*
1658 * CUSE servers compiled on 32bit broke on 64bit kernels because the
1659 * ABI was defined to be 'struct iovec' which is different on 32bit
1660 * and 64bit. Fortunately we can determine which structure the server
1661 * used from the size of the reply.
1662 */
1663 static int fuse_copy_ioctl_iovec_old(struct iovec *dst, void *src,
1664 size_t transferred, unsigned count,
1665 bool is_compat)
1666 {
1667 #ifdef CONFIG_COMPAT
1668 if (count * sizeof(struct compat_iovec) == transferred) {
1669 struct compat_iovec *ciov = src;
1670 unsigned i;
1671
1672 /*
1673 * With this interface a 32bit server cannot support
1674 * non-compat (i.e. ones coming from 64bit apps) ioctl
1675 * requests
1676 */
1677 if (!is_compat)
1678 return -EINVAL;
1679
1680 for (i = 0; i < count; i++) {
1681 dst[i].iov_base = compat_ptr(ciov[i].iov_base);
1682 dst[i].iov_len = ciov[i].iov_len;
1683 }
1684 return 0;
1685 }
1686 #endif
1687
1688 if (count * sizeof(struct iovec) != transferred)
1689 return -EIO;
1690
1691 memcpy(dst, src, transferred);
1692 return 0;
1693 }
1694
1695 /* Make sure iov_length() won't overflow */
1696 static int fuse_verify_ioctl_iov(struct iovec *iov, size_t count)
1697 {
1698 size_t n;
1699 u32 max = FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT;
1700
1701 for (n = 0; n < count; n++) {
1702 if (iov->iov_len > (size_t) max)
1703 return -ENOMEM;
1704 max -= iov->iov_len;
1705 }
1706 return 0;
1707 }
1708
1709 static int fuse_copy_ioctl_iovec(struct fuse_conn *fc, struct iovec *dst,
1710 void *src, size_t transferred, unsigned count,
1711 bool is_compat)
1712 {
1713 unsigned i;
1714 struct fuse_ioctl_iovec *fiov = src;
1715
1716 if (fc->minor < 16) {
1717 return fuse_copy_ioctl_iovec_old(dst, src, transferred,
1718 count, is_compat);
1719 }
1720
1721 if (count * sizeof(struct fuse_ioctl_iovec) != transferred)
1722 return -EIO;
1723
1724 for (i = 0; i < count; i++) {
1725 /* Did the server supply an inappropriate value? */
1726 if (fiov[i].base != (unsigned long) fiov[i].base ||
1727 fiov[i].len != (unsigned long) fiov[i].len)
1728 return -EIO;
1729
1730 dst[i].iov_base = (void __user *) (unsigned long) fiov[i].base;
1731 dst[i].iov_len = (size_t) fiov[i].len;
1732
1733 #ifdef CONFIG_COMPAT
1734 if (is_compat &&
1735 (ptr_to_compat(dst[i].iov_base) != fiov[i].base ||
1736 (compat_size_t) dst[i].iov_len != fiov[i].len))
1737 return -EIO;
1738 #endif
1739 }
1740
1741 return 0;
1742 }
1743
1744
1745 /*
1746 * For ioctls, there is no generic way to determine how much memory
1747 * needs to be read and/or written. Furthermore, ioctls are allowed
1748 * to dereference the passed pointer, so the parameter requires deep
1749 * copying but FUSE has no idea whatsoever about what to copy in or
1750 * out.
1751 *
1752 * This is solved by allowing FUSE server to retry ioctl with
1753 * necessary in/out iovecs. Let's assume the ioctl implementation
1754 * needs to read in the following structure.
1755 *
1756 * struct a {
1757 * char *buf;
1758 * size_t buflen;
1759 * }
1760 *
1761 * On the first callout to FUSE server, inarg->in_size and
1762 * inarg->out_size will be NULL; then, the server completes the ioctl
1763 * with FUSE_IOCTL_RETRY set in out->flags, out->in_iovs set to 1 and
1764 * the actual iov array to
1765 *
1766 * { { .iov_base = inarg.arg, .iov_len = sizeof(struct a) } }
1767 *
1768 * which tells FUSE to copy in the requested area and retry the ioctl.
1769 * On the second round, the server has access to the structure and
1770 * from that it can tell what to look for next, so on the invocation,
1771 * it sets FUSE_IOCTL_RETRY, out->in_iovs to 2 and iov array to
1772 *
1773 * { { .iov_base = inarg.arg, .iov_len = sizeof(struct a) },
1774 * { .iov_base = a.buf, .iov_len = a.buflen } }
1775 *
1776 * FUSE will copy both struct a and the pointed buffer from the
1777 * process doing the ioctl and retry ioctl with both struct a and the
1778 * buffer.
1779 *
1780 * This time, FUSE server has everything it needs and completes ioctl
1781 * without FUSE_IOCTL_RETRY which finishes the ioctl call.
1782 *
1783 * Copying data out works the same way.
1784 *
1785 * Note that if FUSE_IOCTL_UNRESTRICTED is clear, the kernel
1786 * automatically initializes in and out iovs by decoding @cmd with
1787 * _IOC_* macros and the server is not allowed to request RETRY. This
1788 * limits ioctl data transfers to well-formed ioctls and is the forced
1789 * behavior for all FUSE servers.
1790 */
1791 long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
1792 unsigned int flags)
1793 {
1794 struct fuse_file *ff = file->private_data;
1795 struct fuse_conn *fc = ff->fc;
1796 struct fuse_ioctl_in inarg = {
1797 .fh = ff->fh,
1798 .cmd = cmd,
1799 .arg = arg,
1800 .flags = flags
1801 };
1802 struct fuse_ioctl_out outarg;
1803 struct fuse_req *req = NULL;
1804 struct page **pages = NULL;
1805 struct iovec *iov_page = NULL;
1806 struct iovec *in_iov = NULL, *out_iov = NULL;
1807 unsigned int in_iovs = 0, out_iovs = 0, num_pages = 0, max_pages;
1808 size_t in_size, out_size, transferred;
1809 int err;
1810
1811 #if BITS_PER_LONG == 32
1812 inarg.flags |= FUSE_IOCTL_32BIT;
1813 #else
1814 if (flags & FUSE_IOCTL_COMPAT)
1815 inarg.flags |= FUSE_IOCTL_32BIT;
1816 #endif
1817
1818 /* assume all the iovs returned by client always fits in a page */
1819 BUILD_BUG_ON(sizeof(struct fuse_ioctl_iovec) * FUSE_IOCTL_MAX_IOV > PAGE_SIZE);
1820
1821 err = -ENOMEM;
1822 pages = kcalloc(FUSE_MAX_PAGES_PER_REQ, sizeof(pages[0]), GFP_KERNEL);
1823 iov_page = (struct iovec *) __get_free_page(GFP_KERNEL);
1824 if (!pages || !iov_page)
1825 goto out;
1826
1827 /*
1828 * If restricted, initialize IO parameters as encoded in @cmd.
1829 * RETRY from server is not allowed.
1830 */
1831 if (!(flags & FUSE_IOCTL_UNRESTRICTED)) {
1832 struct iovec *iov = iov_page;
1833
1834 iov->iov_base = (void __user *)arg;
1835 iov->iov_len = _IOC_SIZE(cmd);
1836
1837 if (_IOC_DIR(cmd) & _IOC_WRITE) {
1838 in_iov = iov;
1839 in_iovs = 1;
1840 }
1841
1842 if (_IOC_DIR(cmd) & _IOC_READ) {
1843 out_iov = iov;
1844 out_iovs = 1;
1845 }
1846 }
1847
1848 retry:
1849 inarg.in_size = in_size = iov_length(in_iov, in_iovs);
1850 inarg.out_size = out_size = iov_length(out_iov, out_iovs);
1851
1852 /*
1853 * Out data can be used either for actual out data or iovs,
1854 * make sure there always is at least one page.
1855 */
1856 out_size = max_t(size_t, out_size, PAGE_SIZE);
1857 max_pages = DIV_ROUND_UP(max(in_size, out_size), PAGE_SIZE);
1858
1859 /* make sure there are enough buffer pages and init request with them */
1860 err = -ENOMEM;
1861 if (max_pages > FUSE_MAX_PAGES_PER_REQ)
1862 goto out;
1863 while (num_pages < max_pages) {
1864 pages[num_pages] = alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
1865 if (!pages[num_pages])
1866 goto out;
1867 num_pages++;
1868 }
1869
1870 req = fuse_get_req(fc);
1871 if (IS_ERR(req)) {
1872 err = PTR_ERR(req);
1873 req = NULL;
1874 goto out;
1875 }
1876 memcpy(req->pages, pages, sizeof(req->pages[0]) * num_pages);
1877 req->num_pages = num_pages;
1878
1879 /* okay, let's send it to the client */
1880 req->in.h.opcode = FUSE_IOCTL;
1881 req->in.h.nodeid = ff->nodeid;
1882 req->in.numargs = 1;
1883 req->in.args[0].size = sizeof(inarg);
1884 req->in.args[0].value = &inarg;
1885 if (in_size) {
1886 req->in.numargs++;
1887 req->in.args[1].size = in_size;
1888 req->in.argpages = 1;
1889
1890 err = fuse_ioctl_copy_user(pages, in_iov, in_iovs, in_size,
1891 false);
1892 if (err)
1893 goto out;
1894 }
1895
1896 req->out.numargs = 2;
1897 req->out.args[0].size = sizeof(outarg);
1898 req->out.args[0].value = &outarg;
1899 req->out.args[1].size = out_size;
1900 req->out.argpages = 1;
1901 req->out.argvar = 1;
1902
1903 fuse_request_send(fc, req);
1904 err = req->out.h.error;
1905 transferred = req->out.args[1].size;
1906 fuse_put_request(fc, req);
1907 req = NULL;
1908 if (err)
1909 goto out;
1910
1911 /* did it ask for retry? */
1912 if (outarg.flags & FUSE_IOCTL_RETRY) {
1913 void *vaddr;
1914
1915 /* no retry if in restricted mode */
1916 err = -EIO;
1917 if (!(flags & FUSE_IOCTL_UNRESTRICTED))
1918 goto out;
1919
1920 in_iovs = outarg.in_iovs;
1921 out_iovs = outarg.out_iovs;
1922
1923 /*
1924 * Make sure things are in boundary, separate checks
1925 * are to protect against overflow.
1926 */
1927 err = -ENOMEM;
1928 if (in_iovs > FUSE_IOCTL_MAX_IOV ||
1929 out_iovs > FUSE_IOCTL_MAX_IOV ||
1930 in_iovs + out_iovs > FUSE_IOCTL_MAX_IOV)
1931 goto out;
1932
1933 vaddr = kmap_atomic(pages[0]);
1934 err = fuse_copy_ioctl_iovec(fc, iov_page, vaddr,
1935 transferred, in_iovs + out_iovs,
1936 (flags & FUSE_IOCTL_COMPAT) != 0);
1937 kunmap_atomic(vaddr);
1938 if (err)
1939 goto out;
1940
1941 in_iov = iov_page;
1942 out_iov = in_iov + in_iovs;
1943
1944 err = fuse_verify_ioctl_iov(in_iov, in_iovs);
1945 if (err)
1946 goto out;
1947
1948 err = fuse_verify_ioctl_iov(out_iov, out_iovs);
1949 if (err)
1950 goto out;
1951
1952 goto retry;
1953 }
1954
1955 err = -EIO;
1956 if (transferred > inarg.out_size)
1957 goto out;
1958
1959 err = fuse_ioctl_copy_user(pages, out_iov, out_iovs, transferred, true);
1960 out:
1961 if (req)
1962 fuse_put_request(fc, req);
1963 free_page((unsigned long) iov_page);
1964 while (num_pages)
1965 __free_page(pages[--num_pages]);
1966 kfree(pages);
1967
1968 return err ? err : outarg.result;
1969 }
1970 EXPORT_SYMBOL_GPL(fuse_do_ioctl);
1971
1972 long fuse_ioctl_common(struct file *file, unsigned int cmd,
1973 unsigned long arg, unsigned int flags)
1974 {
1975 struct inode *inode = file->f_dentry->d_inode;
1976 struct fuse_conn *fc = get_fuse_conn(inode);
1977
1978 if (!fuse_allow_task(fc, current))
1979 return -EACCES;
1980
1981 if (is_bad_inode(inode))
1982 return -EIO;
1983
1984 return fuse_do_ioctl(file, cmd, arg, flags);
1985 }
1986
1987 static long fuse_file_ioctl(struct file *file, unsigned int cmd,
1988 unsigned long arg)
1989 {
1990 return fuse_ioctl_common(file, cmd, arg, 0);
1991 }
1992
1993 static long fuse_file_compat_ioctl(struct file *file, unsigned int cmd,
1994 unsigned long arg)
1995 {
1996 return fuse_ioctl_common(file, cmd, arg, FUSE_IOCTL_COMPAT);
1997 }
1998
1999 /*
2000 * All files which have been polled are linked to RB tree
2001 * fuse_conn->polled_files which is indexed by kh. Walk the tree and
2002 * find the matching one.
2003 */
2004 static struct rb_node **fuse_find_polled_node(struct fuse_conn *fc, u64 kh,
2005 struct rb_node **parent_out)
2006 {
2007 struct rb_node **link = &fc->polled_files.rb_node;
2008 struct rb_node *last = NULL;
2009
2010 while (*link) {
2011 struct fuse_file *ff;
2012
2013 last = *link;
2014 ff = rb_entry(last, struct fuse_file, polled_node);
2015
2016 if (kh < ff->kh)
2017 link = &last->rb_left;
2018 else if (kh > ff->kh)
2019 link = &last->rb_right;
2020 else
2021 return link;
2022 }
2023
2024 if (parent_out)
2025 *parent_out = last;
2026 return link;
2027 }
2028
2029 /*
2030 * The file is about to be polled. Make sure it's on the polled_files
2031 * RB tree. Note that files once added to the polled_files tree are
2032 * not removed before the file is released. This is because a file
2033 * polled once is likely to be polled again.
2034 */
2035 static void fuse_register_polled_file(struct fuse_conn *fc,
2036 struct fuse_file *ff)
2037 {
2038 spin_lock(&fc->lock);
2039 if (RB_EMPTY_NODE(&ff->polled_node)) {
2040 struct rb_node **link, *parent;
2041
2042 link = fuse_find_polled_node(fc, ff->kh, &parent);
2043 BUG_ON(*link);
2044 rb_link_node(&ff->polled_node, parent, link);
2045 rb_insert_color(&ff->polled_node, &fc->polled_files);
2046 }
2047 spin_unlock(&fc->lock);
2048 }
2049
2050 unsigned fuse_file_poll(struct file *file, poll_table *wait)
2051 {
2052 struct fuse_file *ff = file->private_data;
2053 struct fuse_conn *fc = ff->fc;
2054 struct fuse_poll_in inarg = { .fh = ff->fh, .kh = ff->kh };
2055 struct fuse_poll_out outarg;
2056 struct fuse_req *req;
2057 int err;
2058
2059 if (fc->no_poll)
2060 return DEFAULT_POLLMASK;
2061
2062 poll_wait(file, &ff->poll_wait, wait);
2063
2064 /*
2065 * Ask for notification iff there's someone waiting for it.
2066 * The client may ignore the flag and always notify.
2067 */
2068 if (waitqueue_active(&ff->poll_wait)) {
2069 inarg.flags |= FUSE_POLL_SCHEDULE_NOTIFY;
2070 fuse_register_polled_file(fc, ff);
2071 }
2072
2073 req = fuse_get_req(fc);
2074 if (IS_ERR(req))
2075 return POLLERR;
2076
2077 req->in.h.opcode = FUSE_POLL;
2078 req->in.h.nodeid = ff->nodeid;
2079 req->in.numargs = 1;
2080 req->in.args[0].size = sizeof(inarg);
2081 req->in.args[0].value = &inarg;
2082 req->out.numargs = 1;
2083 req->out.args[0].size = sizeof(outarg);
2084 req->out.args[0].value = &outarg;
2085 fuse_request_send(fc, req);
2086 err = req->out.h.error;
2087 fuse_put_request(fc, req);
2088
2089 if (!err)
2090 return outarg.revents;
2091 if (err == -ENOSYS) {
2092 fc->no_poll = 1;
2093 return DEFAULT_POLLMASK;
2094 }
2095 return POLLERR;
2096 }
2097 EXPORT_SYMBOL_GPL(fuse_file_poll);
2098
2099 /*
2100 * This is called from fuse_handle_notify() on FUSE_NOTIFY_POLL and
2101 * wakes up the poll waiters.
2102 */
2103 int fuse_notify_poll_wakeup(struct fuse_conn *fc,
2104 struct fuse_notify_poll_wakeup_out *outarg)
2105 {
2106 u64 kh = outarg->kh;
2107 struct rb_node **link;
2108
2109 spin_lock(&fc->lock);
2110
2111 link = fuse_find_polled_node(fc, kh, NULL);
2112 if (*link) {
2113 struct fuse_file *ff;
2114
2115 ff = rb_entry(*link, struct fuse_file, polled_node);
2116 wake_up_interruptible_sync(&ff->poll_wait);
2117 }
2118
2119 spin_unlock(&fc->lock);
2120 return 0;
2121 }
2122
2123 static ssize_t fuse_loop_dio(struct file *filp, const struct iovec *iov,
2124 unsigned long nr_segs, loff_t *ppos, int rw)
2125 {
2126 const struct iovec *vector = iov;
2127 ssize_t ret = 0;
2128
2129 while (nr_segs > 0) {
2130 void __user *base;
2131 size_t len;
2132 ssize_t nr;
2133
2134 base = vector->iov_base;
2135 len = vector->iov_len;
2136 vector++;
2137 nr_segs--;
2138
2139 if (rw == WRITE)
2140 nr = __fuse_direct_write(filp, base, len, ppos);
2141 else
2142 nr = fuse_direct_read(filp, base, len, ppos);
2143
2144 if (nr < 0) {
2145 if (!ret)
2146 ret = nr;
2147 break;
2148 }
2149 ret += nr;
2150 if (nr != len)
2151 break;
2152 }
2153
2154 return ret;
2155 }
2156
2157
2158 static ssize_t
2159 fuse_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
2160 loff_t offset, unsigned long nr_segs)
2161 {
2162 ssize_t ret = 0;
2163 struct file *file = NULL;
2164 loff_t pos = 0;
2165
2166 file = iocb->ki_filp;
2167 pos = offset;
2168
2169 ret = fuse_loop_dio(file, iov, nr_segs, &pos, rw);
2170
2171 return ret;
2172 }
2173
2174 static const struct file_operations fuse_file_operations = {
2175 .llseek = fuse_file_llseek,
2176 .read = do_sync_read,
2177 .aio_read = fuse_file_aio_read,
2178 .write = do_sync_write,
2179 .aio_write = fuse_file_aio_write,
2180 .mmap = fuse_file_mmap,
2181 .open = fuse_open,
2182 .flush = fuse_flush,
2183 .release = fuse_release,
2184 .fsync = fuse_fsync,
2185 .lock = fuse_file_lock,
2186 .flock = fuse_file_flock,
2187 .splice_read = generic_file_splice_read,
2188 .unlocked_ioctl = fuse_file_ioctl,
2189 .compat_ioctl = fuse_file_compat_ioctl,
2190 .poll = fuse_file_poll,
2191 };
2192
2193 static const struct file_operations fuse_direct_io_file_operations = {
2194 .llseek = fuse_file_llseek,
2195 .read = fuse_direct_read,
2196 .write = fuse_direct_write,
2197 .mmap = fuse_direct_mmap,
2198 .open = fuse_open,
2199 .flush = fuse_flush,
2200 .release = fuse_release,
2201 .fsync = fuse_fsync,
2202 .lock = fuse_file_lock,
2203 .flock = fuse_file_flock,
2204 .unlocked_ioctl = fuse_file_ioctl,
2205 .compat_ioctl = fuse_file_compat_ioctl,
2206 .poll = fuse_file_poll,
2207 /* no splice_read */
2208 };
2209
2210 static const struct address_space_operations fuse_file_aops = {
2211 .readpage = fuse_readpage,
2212 .writepage = fuse_writepage,
2213 .launder_page = fuse_launder_page,
2214 .readpages = fuse_readpages,
2215 .set_page_dirty = __set_page_dirty_nobuffers,
2216 .bmap = fuse_bmap,
2217 .direct_IO = fuse_direct_IO,
2218 };
2219
2220 void fuse_init_file_inode(struct inode *inode)
2221 {
2222 inode->i_fop = &fuse_file_operations;
2223 inode->i_data.a_ops = &fuse_file_aops;
2224 }
Linux kernel - Deliverables
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