xref: /linux/fs/fuse/file.c (revision 14b42963f64b98ab61fa9723c03d71aa5ef4f862)
1 /*
2   FUSE: Filesystem in Userspace
3   Copyright (C) 2001-2006  Miklos Szeredi <miklos@szeredi.hu>
4 
5   This program can be distributed under the terms of the GNU GPL.
6   See the file COPYING.
7 */
8 
9 #include "fuse_i.h"
10 
11 #include <linux/pagemap.h>
12 #include <linux/slab.h>
13 #include <linux/kernel.h>
14 
15 static const struct file_operations fuse_direct_io_file_operations;
16 
17 static int fuse_send_open(struct inode *inode, struct file *file, int isdir,
18 			  struct fuse_open_out *outargp)
19 {
20 	struct fuse_conn *fc = get_fuse_conn(inode);
21 	struct fuse_open_in inarg;
22 	struct fuse_req *req;
23 	int err;
24 
25 	req = fuse_get_req(fc);
26 	if (IS_ERR(req))
27 		return PTR_ERR(req);
28 
29 	memset(&inarg, 0, sizeof(inarg));
30 	inarg.flags = file->f_flags & ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);
31 	req->in.h.opcode = isdir ? FUSE_OPENDIR : FUSE_OPEN;
32 	req->in.h.nodeid = get_node_id(inode);
33 	req->in.numargs = 1;
34 	req->in.args[0].size = sizeof(inarg);
35 	req->in.args[0].value = &inarg;
36 	req->out.numargs = 1;
37 	req->out.args[0].size = sizeof(*outargp);
38 	req->out.args[0].value = outargp;
39 	request_send(fc, req);
40 	err = req->out.h.error;
41 	fuse_put_request(fc, req);
42 
43 	return err;
44 }
45 
46 struct fuse_file *fuse_file_alloc(void)
47 {
48 	struct fuse_file *ff;
49 	ff = kmalloc(sizeof(struct fuse_file), GFP_KERNEL);
50 	if (ff) {
51 		ff->reserved_req = fuse_request_alloc();
52 		if (!ff->reserved_req) {
53 			kfree(ff);
54 			ff = NULL;
55 		}
56 	}
57 	return ff;
58 }
59 
60 void fuse_file_free(struct fuse_file *ff)
61 {
62 	fuse_request_free(ff->reserved_req);
63 	kfree(ff);
64 }
65 
66 void fuse_finish_open(struct inode *inode, struct file *file,
67 		      struct fuse_file *ff, struct fuse_open_out *outarg)
68 {
69 	if (outarg->open_flags & FOPEN_DIRECT_IO)
70 		file->f_op = &fuse_direct_io_file_operations;
71 	if (!(outarg->open_flags & FOPEN_KEEP_CACHE))
72 		invalidate_inode_pages(inode->i_mapping);
73 	ff->fh = outarg->fh;
74 	file->private_data = ff;
75 }
76 
77 int fuse_open_common(struct inode *inode, struct file *file, int isdir)
78 {
79 	struct fuse_open_out outarg;
80 	struct fuse_file *ff;
81 	int err;
82 
83 	/* VFS checks this, but only _after_ ->open() */
84 	if (file->f_flags & O_DIRECT)
85 		return -EINVAL;
86 
87 	err = generic_file_open(inode, file);
88 	if (err)
89 		return err;
90 
91 	/* If opening the root node, no lookup has been performed on
92 	   it, so the attributes must be refreshed */
93 	if (get_node_id(inode) == FUSE_ROOT_ID) {
94 		err = fuse_do_getattr(inode);
95 		if (err)
96 		 	return err;
97 	}
98 
99 	ff = fuse_file_alloc();
100 	if (!ff)
101 		return -ENOMEM;
102 
103 	err = fuse_send_open(inode, file, isdir, &outarg);
104 	if (err)
105 		fuse_file_free(ff);
106 	else {
107 		if (isdir)
108 			outarg.open_flags &= ~FOPEN_DIRECT_IO;
109 		fuse_finish_open(inode, file, ff, &outarg);
110 	}
111 
112 	return err;
113 }
114 
115 struct fuse_req *fuse_release_fill(struct fuse_file *ff, u64 nodeid, int flags,
116 				   int opcode)
117 {
118 	struct fuse_req *req = ff->reserved_req;
119 	struct fuse_release_in *inarg = &req->misc.release_in;
120 
121 	inarg->fh = ff->fh;
122 	inarg->flags = flags;
123 	req->in.h.opcode = opcode;
124 	req->in.h.nodeid = nodeid;
125 	req->in.numargs = 1;
126 	req->in.args[0].size = sizeof(struct fuse_release_in);
127 	req->in.args[0].value = inarg;
128 	kfree(ff);
129 
130 	return req;
131 }
132 
133 int fuse_release_common(struct inode *inode, struct file *file, int isdir)
134 {
135 	struct fuse_file *ff = file->private_data;
136 	if (ff) {
137 		struct fuse_conn *fc = get_fuse_conn(inode);
138 		struct fuse_req *req;
139 
140 		req = fuse_release_fill(ff, get_node_id(inode), file->f_flags,
141 					isdir ? FUSE_RELEASEDIR : FUSE_RELEASE);
142 
143 		/* Hold vfsmount and dentry until release is finished */
144 		req->vfsmount = mntget(file->f_vfsmnt);
145 		req->dentry = dget(file->f_dentry);
146 		request_send_background(fc, req);
147 	}
148 
149 	/* Return value is ignored by VFS */
150 	return 0;
151 }
152 
153 static int fuse_open(struct inode *inode, struct file *file)
154 {
155 	return fuse_open_common(inode, file, 0);
156 }
157 
158 static int fuse_release(struct inode *inode, struct file *file)
159 {
160 	return fuse_release_common(inode, file, 0);
161 }
162 
163 /*
164  * Scramble the ID space with XTEA, so that the value of the files_struct
165  * pointer is not exposed to userspace.
166  */
167 static u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id)
168 {
169 	u32 *k = fc->scramble_key;
170 	u64 v = (unsigned long) id;
171 	u32 v0 = v;
172 	u32 v1 = v >> 32;
173 	u32 sum = 0;
174 	int i;
175 
176 	for (i = 0; i < 32; i++) {
177 		v0 += ((v1 << 4 ^ v1 >> 5) + v1) ^ (sum + k[sum & 3]);
178 		sum += 0x9E3779B9;
179 		v1 += ((v0 << 4 ^ v0 >> 5) + v0) ^ (sum + k[sum>>11 & 3]);
180 	}
181 
182 	return (u64) v0 + ((u64) v1 << 32);
183 }
184 
185 static int fuse_flush(struct file *file, fl_owner_t id)
186 {
187 	struct inode *inode = file->f_dentry->d_inode;
188 	struct fuse_conn *fc = get_fuse_conn(inode);
189 	struct fuse_file *ff = file->private_data;
190 	struct fuse_req *req;
191 	struct fuse_flush_in inarg;
192 	int err;
193 
194 	if (is_bad_inode(inode))
195 		return -EIO;
196 
197 	if (fc->no_flush)
198 		return 0;
199 
200 	req = fuse_get_req_nofail(fc, file);
201 	memset(&inarg, 0, sizeof(inarg));
202 	inarg.fh = ff->fh;
203 	inarg.lock_owner = fuse_lock_owner_id(fc, id);
204 	req->in.h.opcode = FUSE_FLUSH;
205 	req->in.h.nodeid = get_node_id(inode);
206 	req->in.numargs = 1;
207 	req->in.args[0].size = sizeof(inarg);
208 	req->in.args[0].value = &inarg;
209 	req->force = 1;
210 	request_send(fc, req);
211 	err = req->out.h.error;
212 	fuse_put_request(fc, req);
213 	if (err == -ENOSYS) {
214 		fc->no_flush = 1;
215 		err = 0;
216 	}
217 	return err;
218 }
219 
220 int fuse_fsync_common(struct file *file, struct dentry *de, int datasync,
221 		      int isdir)
222 {
223 	struct inode *inode = de->d_inode;
224 	struct fuse_conn *fc = get_fuse_conn(inode);
225 	struct fuse_file *ff = file->private_data;
226 	struct fuse_req *req;
227 	struct fuse_fsync_in inarg;
228 	int err;
229 
230 	if (is_bad_inode(inode))
231 		return -EIO;
232 
233 	if ((!isdir && fc->no_fsync) || (isdir && fc->no_fsyncdir))
234 		return 0;
235 
236 	req = fuse_get_req(fc);
237 	if (IS_ERR(req))
238 		return PTR_ERR(req);
239 
240 	memset(&inarg, 0, sizeof(inarg));
241 	inarg.fh = ff->fh;
242 	inarg.fsync_flags = datasync ? 1 : 0;
243 	req->in.h.opcode = isdir ? FUSE_FSYNCDIR : FUSE_FSYNC;
244 	req->in.h.nodeid = get_node_id(inode);
245 	req->in.numargs = 1;
246 	req->in.args[0].size = sizeof(inarg);
247 	req->in.args[0].value = &inarg;
248 	request_send(fc, req);
249 	err = req->out.h.error;
250 	fuse_put_request(fc, req);
251 	if (err == -ENOSYS) {
252 		if (isdir)
253 			fc->no_fsyncdir = 1;
254 		else
255 			fc->no_fsync = 1;
256 		err = 0;
257 	}
258 	return err;
259 }
260 
261 static int fuse_fsync(struct file *file, struct dentry *de, int datasync)
262 {
263 	return fuse_fsync_common(file, de, datasync, 0);
264 }
265 
266 void fuse_read_fill(struct fuse_req *req, struct file *file,
267 		    struct inode *inode, loff_t pos, size_t count, int opcode)
268 {
269 	struct fuse_file *ff = file->private_data;
270 	struct fuse_read_in *inarg = &req->misc.read_in;
271 
272 	inarg->fh = ff->fh;
273 	inarg->offset = pos;
274 	inarg->size = count;
275 	req->in.h.opcode = opcode;
276 	req->in.h.nodeid = get_node_id(inode);
277 	req->in.numargs = 1;
278 	req->in.args[0].size = sizeof(struct fuse_read_in);
279 	req->in.args[0].value = inarg;
280 	req->out.argpages = 1;
281 	req->out.argvar = 1;
282 	req->out.numargs = 1;
283 	req->out.args[0].size = count;
284 }
285 
286 static size_t fuse_send_read(struct fuse_req *req, struct file *file,
287 			     struct inode *inode, loff_t pos, size_t count)
288 {
289 	struct fuse_conn *fc = get_fuse_conn(inode);
290 	fuse_read_fill(req, file, inode, pos, count, FUSE_READ);
291 	request_send(fc, req);
292 	return req->out.args[0].size;
293 }
294 
295 static int fuse_readpage(struct file *file, struct page *page)
296 {
297 	struct inode *inode = page->mapping->host;
298 	struct fuse_conn *fc = get_fuse_conn(inode);
299 	struct fuse_req *req;
300 	int err;
301 
302 	err = -EIO;
303 	if (is_bad_inode(inode))
304 		goto out;
305 
306 	req = fuse_get_req(fc);
307 	err = PTR_ERR(req);
308 	if (IS_ERR(req))
309 		goto out;
310 
311 	req->out.page_zeroing = 1;
312 	req->num_pages = 1;
313 	req->pages[0] = page;
314 	fuse_send_read(req, file, inode, page_offset(page), PAGE_CACHE_SIZE);
315 	err = req->out.h.error;
316 	fuse_put_request(fc, req);
317 	if (!err)
318 		SetPageUptodate(page);
319 	fuse_invalidate_attr(inode); /* atime changed */
320  out:
321 	unlock_page(page);
322 	return err;
323 }
324 
325 static void fuse_readpages_end(struct fuse_conn *fc, struct fuse_req *req)
326 {
327 	int i;
328 
329 	fuse_invalidate_attr(req->pages[0]->mapping->host); /* atime changed */
330 
331 	for (i = 0; i < req->num_pages; i++) {
332 		struct page *page = req->pages[i];
333 		if (!req->out.h.error)
334 			SetPageUptodate(page);
335 		else
336 			SetPageError(page);
337 		unlock_page(page);
338 	}
339 	fuse_put_request(fc, req);
340 }
341 
342 static void fuse_send_readpages(struct fuse_req *req, struct file *file,
343 				struct inode *inode)
344 {
345 	struct fuse_conn *fc = get_fuse_conn(inode);
346 	loff_t pos = page_offset(req->pages[0]);
347 	size_t count = req->num_pages << PAGE_CACHE_SHIFT;
348 	req->out.page_zeroing = 1;
349 	fuse_read_fill(req, file, inode, pos, count, FUSE_READ);
350 	if (fc->async_read) {
351 		get_file(file);
352 		req->file = file;
353 		req->end = fuse_readpages_end;
354 		request_send_background(fc, req);
355 	} else {
356 		request_send(fc, req);
357 		fuse_readpages_end(fc, req);
358 	}
359 }
360 
361 struct fuse_readpages_data {
362 	struct fuse_req *req;
363 	struct file *file;
364 	struct inode *inode;
365 };
366 
367 static int fuse_readpages_fill(void *_data, struct page *page)
368 {
369 	struct fuse_readpages_data *data = _data;
370 	struct fuse_req *req = data->req;
371 	struct inode *inode = data->inode;
372 	struct fuse_conn *fc = get_fuse_conn(inode);
373 
374 	if (req->num_pages &&
375 	    (req->num_pages == FUSE_MAX_PAGES_PER_REQ ||
376 	     (req->num_pages + 1) * PAGE_CACHE_SIZE > fc->max_read ||
377 	     req->pages[req->num_pages - 1]->index + 1 != page->index)) {
378 		fuse_send_readpages(req, data->file, inode);
379 		data->req = req = fuse_get_req(fc);
380 		if (IS_ERR(req)) {
381 			unlock_page(page);
382 			return PTR_ERR(req);
383 		}
384 	}
385 	req->pages[req->num_pages] = page;
386 	req->num_pages ++;
387 	return 0;
388 }
389 
390 static int fuse_readpages(struct file *file, struct address_space *mapping,
391 			  struct list_head *pages, unsigned nr_pages)
392 {
393 	struct inode *inode = mapping->host;
394 	struct fuse_conn *fc = get_fuse_conn(inode);
395 	struct fuse_readpages_data data;
396 	int err;
397 
398 	if (is_bad_inode(inode))
399 		return -EIO;
400 
401 	data.file = file;
402 	data.inode = inode;
403 	data.req = fuse_get_req(fc);
404 	if (IS_ERR(data.req))
405 		return PTR_ERR(data.req);
406 
407 	err = read_cache_pages(mapping, pages, fuse_readpages_fill, &data);
408 	if (!err) {
409 		if (data.req->num_pages)
410 			fuse_send_readpages(data.req, file, inode);
411 		else
412 			fuse_put_request(fc, data.req);
413 	}
414 	return err;
415 }
416 
417 static size_t fuse_send_write(struct fuse_req *req, struct file *file,
418 			      struct inode *inode, loff_t pos, size_t count)
419 {
420 	struct fuse_conn *fc = get_fuse_conn(inode);
421 	struct fuse_file *ff = file->private_data;
422 	struct fuse_write_in inarg;
423 	struct fuse_write_out outarg;
424 
425 	memset(&inarg, 0, sizeof(struct fuse_write_in));
426 	inarg.fh = ff->fh;
427 	inarg.offset = pos;
428 	inarg.size = count;
429 	req->in.h.opcode = FUSE_WRITE;
430 	req->in.h.nodeid = get_node_id(inode);
431 	req->in.argpages = 1;
432 	req->in.numargs = 2;
433 	req->in.args[0].size = sizeof(struct fuse_write_in);
434 	req->in.args[0].value = &inarg;
435 	req->in.args[1].size = count;
436 	req->out.numargs = 1;
437 	req->out.args[0].size = sizeof(struct fuse_write_out);
438 	req->out.args[0].value = &outarg;
439 	request_send(fc, req);
440 	return outarg.size;
441 }
442 
443 static int fuse_prepare_write(struct file *file, struct page *page,
444 			      unsigned offset, unsigned to)
445 {
446 	/* No op */
447 	return 0;
448 }
449 
450 static int fuse_commit_write(struct file *file, struct page *page,
451 			     unsigned offset, unsigned to)
452 {
453 	int err;
454 	size_t nres;
455 	unsigned count = to - offset;
456 	struct inode *inode = page->mapping->host;
457 	struct fuse_conn *fc = get_fuse_conn(inode);
458 	loff_t pos = page_offset(page) + offset;
459 	struct fuse_req *req;
460 
461 	if (is_bad_inode(inode))
462 		return -EIO;
463 
464 	req = fuse_get_req(fc);
465 	if (IS_ERR(req))
466 		return PTR_ERR(req);
467 
468 	req->num_pages = 1;
469 	req->pages[0] = page;
470 	req->page_offset = offset;
471 	nres = fuse_send_write(req, file, inode, pos, count);
472 	err = req->out.h.error;
473 	fuse_put_request(fc, req);
474 	if (!err && nres != count)
475 		err = -EIO;
476 	if (!err) {
477 		pos += count;
478 		if (pos > i_size_read(inode))
479 			i_size_write(inode, pos);
480 
481 		if (offset == 0 && to == PAGE_CACHE_SIZE) {
482 			clear_page_dirty(page);
483 			SetPageUptodate(page);
484 		}
485 	}
486 	fuse_invalidate_attr(inode);
487 	return err;
488 }
489 
490 static void fuse_release_user_pages(struct fuse_req *req, int write)
491 {
492 	unsigned i;
493 
494 	for (i = 0; i < req->num_pages; i++) {
495 		struct page *page = req->pages[i];
496 		if (write)
497 			set_page_dirty_lock(page);
498 		put_page(page);
499 	}
500 }
501 
502 static int fuse_get_user_pages(struct fuse_req *req, const char __user *buf,
503 			       unsigned nbytes, int write)
504 {
505 	unsigned long user_addr = (unsigned long) buf;
506 	unsigned offset = user_addr & ~PAGE_MASK;
507 	int npages;
508 
509 	/* This doesn't work with nfsd */
510 	if (!current->mm)
511 		return -EPERM;
512 
513 	nbytes = min(nbytes, (unsigned) FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT);
514 	npages = (nbytes + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
515 	npages = min(max(npages, 1), FUSE_MAX_PAGES_PER_REQ);
516 	down_read(&current->mm->mmap_sem);
517 	npages = get_user_pages(current, current->mm, user_addr, npages, write,
518 				0, req->pages, NULL);
519 	up_read(&current->mm->mmap_sem);
520 	if (npages < 0)
521 		return npages;
522 
523 	req->num_pages = npages;
524 	req->page_offset = offset;
525 	return 0;
526 }
527 
528 static ssize_t fuse_direct_io(struct file *file, const char __user *buf,
529 			      size_t count, loff_t *ppos, int write)
530 {
531 	struct inode *inode = file->f_dentry->d_inode;
532 	struct fuse_conn *fc = get_fuse_conn(inode);
533 	size_t nmax = write ? fc->max_write : fc->max_read;
534 	loff_t pos = *ppos;
535 	ssize_t res = 0;
536 	struct fuse_req *req;
537 
538 	if (is_bad_inode(inode))
539 		return -EIO;
540 
541 	req = fuse_get_req(fc);
542 	if (IS_ERR(req))
543 		return PTR_ERR(req);
544 
545 	while (count) {
546 		size_t nres;
547 		size_t nbytes = min(count, nmax);
548 		int err = fuse_get_user_pages(req, buf, nbytes, !write);
549 		if (err) {
550 			res = err;
551 			break;
552 		}
553 		nbytes = (req->num_pages << PAGE_SHIFT) - req->page_offset;
554 		nbytes = min(count, nbytes);
555 		if (write)
556 			nres = fuse_send_write(req, file, inode, pos, nbytes);
557 		else
558 			nres = fuse_send_read(req, file, inode, pos, nbytes);
559 		fuse_release_user_pages(req, !write);
560 		if (req->out.h.error) {
561 			if (!res)
562 				res = req->out.h.error;
563 			break;
564 		} else if (nres > nbytes) {
565 			res = -EIO;
566 			break;
567 		}
568 		count -= nres;
569 		res += nres;
570 		pos += nres;
571 		buf += nres;
572 		if (nres != nbytes)
573 			break;
574 		if (count) {
575 			fuse_put_request(fc, req);
576 			req = fuse_get_req(fc);
577 			if (IS_ERR(req))
578 				break;
579 		}
580 	}
581 	fuse_put_request(fc, req);
582 	if (res > 0) {
583 		if (write && pos > i_size_read(inode))
584 			i_size_write(inode, pos);
585 		*ppos = pos;
586 	}
587 	fuse_invalidate_attr(inode);
588 
589 	return res;
590 }
591 
592 static ssize_t fuse_direct_read(struct file *file, char __user *buf,
593 				     size_t count, loff_t *ppos)
594 {
595 	return fuse_direct_io(file, buf, count, ppos, 0);
596 }
597 
598 static ssize_t fuse_direct_write(struct file *file, const char __user *buf,
599 				 size_t count, loff_t *ppos)
600 {
601 	struct inode *inode = file->f_dentry->d_inode;
602 	ssize_t res;
603 	/* Don't allow parallel writes to the same file */
604 	mutex_lock(&inode->i_mutex);
605 	res = fuse_direct_io(file, buf, count, ppos, 1);
606 	mutex_unlock(&inode->i_mutex);
607 	return res;
608 }
609 
610 static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma)
611 {
612 	if ((vma->vm_flags & VM_SHARED)) {
613 		if ((vma->vm_flags & VM_WRITE))
614 			return -ENODEV;
615 		else
616 			vma->vm_flags &= ~VM_MAYWRITE;
617 	}
618 	return generic_file_mmap(file, vma);
619 }
620 
621 static int fuse_set_page_dirty(struct page *page)
622 {
623 	printk("fuse_set_page_dirty: should not happen\n");
624 	dump_stack();
625 	return 0;
626 }
627 
628 static int convert_fuse_file_lock(const struct fuse_file_lock *ffl,
629 				  struct file_lock *fl)
630 {
631 	switch (ffl->type) {
632 	case F_UNLCK:
633 		break;
634 
635 	case F_RDLCK:
636 	case F_WRLCK:
637 		if (ffl->start > OFFSET_MAX || ffl->end > OFFSET_MAX ||
638 		    ffl->end < ffl->start)
639 			return -EIO;
640 
641 		fl->fl_start = ffl->start;
642 		fl->fl_end = ffl->end;
643 		fl->fl_pid = ffl->pid;
644 		break;
645 
646 	default:
647 		return -EIO;
648 	}
649 	fl->fl_type = ffl->type;
650 	return 0;
651 }
652 
653 static void fuse_lk_fill(struct fuse_req *req, struct file *file,
654 			 const struct file_lock *fl, int opcode, pid_t pid)
655 {
656 	struct inode *inode = file->f_dentry->d_inode;
657 	struct fuse_conn *fc = get_fuse_conn(inode);
658 	struct fuse_file *ff = file->private_data;
659 	struct fuse_lk_in *arg = &req->misc.lk_in;
660 
661 	arg->fh = ff->fh;
662 	arg->owner = fuse_lock_owner_id(fc, fl->fl_owner);
663 	arg->lk.start = fl->fl_start;
664 	arg->lk.end = fl->fl_end;
665 	arg->lk.type = fl->fl_type;
666 	arg->lk.pid = pid;
667 	req->in.h.opcode = opcode;
668 	req->in.h.nodeid = get_node_id(inode);
669 	req->in.numargs = 1;
670 	req->in.args[0].size = sizeof(*arg);
671 	req->in.args[0].value = arg;
672 }
673 
674 static int fuse_getlk(struct file *file, struct file_lock *fl)
675 {
676 	struct inode *inode = file->f_dentry->d_inode;
677 	struct fuse_conn *fc = get_fuse_conn(inode);
678 	struct fuse_req *req;
679 	struct fuse_lk_out outarg;
680 	int err;
681 
682 	req = fuse_get_req(fc);
683 	if (IS_ERR(req))
684 		return PTR_ERR(req);
685 
686 	fuse_lk_fill(req, file, fl, FUSE_GETLK, 0);
687 	req->out.numargs = 1;
688 	req->out.args[0].size = sizeof(outarg);
689 	req->out.args[0].value = &outarg;
690 	request_send(fc, req);
691 	err = req->out.h.error;
692 	fuse_put_request(fc, req);
693 	if (!err)
694 		err = convert_fuse_file_lock(&outarg.lk, fl);
695 
696 	return err;
697 }
698 
699 static int fuse_setlk(struct file *file, struct file_lock *fl)
700 {
701 	struct inode *inode = file->f_dentry->d_inode;
702 	struct fuse_conn *fc = get_fuse_conn(inode);
703 	struct fuse_req *req;
704 	int opcode = (fl->fl_flags & FL_SLEEP) ? FUSE_SETLKW : FUSE_SETLK;
705 	pid_t pid = fl->fl_type != F_UNLCK ? current->tgid : 0;
706 	int err;
707 
708 	/* Unlock on close is handled by the flush method */
709 	if (fl->fl_flags & FL_CLOSE)
710 		return 0;
711 
712 	req = fuse_get_req(fc);
713 	if (IS_ERR(req))
714 		return PTR_ERR(req);
715 
716 	fuse_lk_fill(req, file, fl, opcode, pid);
717 	request_send(fc, req);
718 	err = req->out.h.error;
719 	/* locking is restartable */
720 	if (err == -EINTR)
721 		err = -ERESTARTSYS;
722 	fuse_put_request(fc, req);
723 	return err;
724 }
725 
726 static int fuse_file_lock(struct file *file, int cmd, struct file_lock *fl)
727 {
728 	struct inode *inode = file->f_dentry->d_inode;
729 	struct fuse_conn *fc = get_fuse_conn(inode);
730 	int err;
731 
732 	if (cmd == F_GETLK) {
733 		if (fc->no_lock) {
734 			if (!posix_test_lock(file, fl, fl))
735 				fl->fl_type = F_UNLCK;
736 			err = 0;
737 		} else
738 			err = fuse_getlk(file, fl);
739 	} else {
740 		if (fc->no_lock)
741 			err = posix_lock_file_wait(file, fl);
742 		else
743 			err = fuse_setlk(file, fl);
744 	}
745 	return err;
746 }
747 
748 static const struct file_operations fuse_file_operations = {
749 	.llseek		= generic_file_llseek,
750 	.read		= generic_file_read,
751 	.write		= generic_file_write,
752 	.mmap		= fuse_file_mmap,
753 	.open		= fuse_open,
754 	.flush		= fuse_flush,
755 	.release	= fuse_release,
756 	.fsync		= fuse_fsync,
757 	.lock		= fuse_file_lock,
758 	.sendfile	= generic_file_sendfile,
759 };
760 
761 static const struct file_operations fuse_direct_io_file_operations = {
762 	.llseek		= generic_file_llseek,
763 	.read		= fuse_direct_read,
764 	.write		= fuse_direct_write,
765 	.open		= fuse_open,
766 	.flush		= fuse_flush,
767 	.release	= fuse_release,
768 	.fsync		= fuse_fsync,
769 	.lock		= fuse_file_lock,
770 	/* no mmap and sendfile */
771 };
772 
773 static const struct address_space_operations fuse_file_aops  = {
774 	.readpage	= fuse_readpage,
775 	.prepare_write	= fuse_prepare_write,
776 	.commit_write	= fuse_commit_write,
777 	.readpages	= fuse_readpages,
778 	.set_page_dirty	= fuse_set_page_dirty,
779 };
780 
781 void fuse_init_file_inode(struct inode *inode)
782 {
783 	inode->i_fop = &fuse_file_operations;
784 	inode->i_data.a_ops = &fuse_file_aops;
785 }
786