file.c 47.7 KB
Newer Older
1
2
/*
  FUSE: Filesystem in Userspace
Miklos Szeredi's avatar
Miklos Szeredi committed
3
  Copyright (C) 2001-2008  Miklos Szeredi <miklos@szeredi.hu>
4
5
6
7
8
9
10
11
12
13

  This program can be distributed under the terms of the GNU GPL.
  See the file COPYING.
*/

#include "fuse_i.h"

#include <linux/pagemap.h>
#include <linux/slab.h>
#include <linux/kernel.h>
Alexey Dobriyan's avatar
Alexey Dobriyan committed
14
#include <linux/sched.h>
15

16
static const struct file_operations fuse_direct_io_file_operations;
17

18
19
static int fuse_send_open(struct inode *inode, struct file *file, int isdir,
			  struct fuse_open_out *outargp)
20
21
22
{
	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_open_in inarg;
23
24
25
	struct fuse_req *req;
	int err;

26
27
28
	req = fuse_get_req(fc);
	if (IS_ERR(req))
		return PTR_ERR(req);
29
30

	memset(&inarg, 0, sizeof(inarg));
31
32
33
	inarg.flags = file->f_flags & ~(O_CREAT | O_EXCL | O_NOCTTY);
	if (!fc->atomic_o_trunc)
		inarg.flags &= ~O_TRUNC;
34
35
36
37
38
39
40
41
	req->in.h.opcode = isdir ? FUSE_OPENDIR : FUSE_OPEN;
	req->in.h.nodeid = get_node_id(inode);
	req->in.numargs = 1;
	req->in.args[0].size = sizeof(inarg);
	req->in.args[0].value = &inarg;
	req->out.numargs = 1;
	req->out.args[0].size = sizeof(*outargp);
	req->out.args[0].value = outargp;
42
	fuse_request_send(fc, req);
43
44
45
46
47
48
	err = req->out.h.error;
	fuse_put_request(fc, req);

	return err;
}

Tejun Heo's avatar
Tejun Heo committed
49
struct fuse_file *fuse_file_alloc(struct fuse_conn *fc)
50
51
{
	struct fuse_file *ff;
Tejun Heo's avatar
Tejun Heo committed
52

53
	ff = kmalloc(sizeof(struct fuse_file), GFP_KERNEL);
Tejun Heo's avatar
Tejun Heo committed
54
55
56
57
58
59
60
	if (unlikely(!ff))
		return NULL;

	ff->reserved_req = fuse_request_alloc();
	if (unlikely(!ff->reserved_req)) {
		kfree(ff);
		return NULL;
61
	}
Tejun Heo's avatar
Tejun Heo committed
62
63
64
65
66
67
68
69
70
71

	INIT_LIST_HEAD(&ff->write_entry);
	atomic_set(&ff->count, 0);
	RB_CLEAR_NODE(&ff->polled_node);
	init_waitqueue_head(&ff->poll_wait);

	spin_lock(&fc->lock);
	ff->kh = ++fc->khctr;
	spin_unlock(&fc->lock);

72
73
74
75
76
	return ff;
}

void fuse_file_free(struct fuse_file *ff)
{
77
	fuse_request_free(ff->reserved_req);
78
79
80
	kfree(ff);
}

81
82
83
84
85
86
static struct fuse_file *fuse_file_get(struct fuse_file *ff)
{
	atomic_inc(&ff->count);
	return ff;
}

Miklos Szeredi's avatar
Miklos Szeredi committed
87
88
static void fuse_release_end(struct fuse_conn *fc, struct fuse_req *req)
{
89
	path_put(&req->misc.release.path);
Miklos Szeredi's avatar
Miklos Szeredi committed
90
91
}

92
93
94
95
static void fuse_file_put(struct fuse_file *ff)
{
	if (atomic_dec_and_test(&ff->count)) {
		struct fuse_req *req = ff->reserved_req;
96
		struct inode *inode = req->misc.release.path.dentry->d_inode;
97
		struct fuse_conn *fc = get_fuse_conn(inode);
Miklos Szeredi's avatar
Miklos Szeredi committed
98
		req->end = fuse_release_end;
99
		fuse_request_send_background(fc, req);
100
101
102
103
		kfree(ff);
	}
}

104
105
106
107
108
109
void fuse_finish_open(struct inode *inode, struct file *file,
		      struct fuse_file *ff, struct fuse_open_out *outarg)
{
	if (outarg->open_flags & FOPEN_DIRECT_IO)
		file->f_op = &fuse_direct_io_file_operations;
	if (!(outarg->open_flags & FOPEN_KEEP_CACHE))
Miklos Szeredi's avatar
Miklos Szeredi committed
110
		invalidate_inode_pages2(inode->i_mapping);
Tejun Heo's avatar
Tejun Heo committed
111
112
	if (outarg->open_flags & FOPEN_NONSEEKABLE)
		nonseekable_open(inode, file);
113
	ff->fh = outarg->fh;
114
	file->private_data = fuse_file_get(ff);
115
116
117
118
}

int fuse_open_common(struct inode *inode, struct file *file, int isdir)
{
Tejun Heo's avatar
Tejun Heo committed
119
	struct fuse_conn *fc = get_fuse_conn(inode);
120
121
122
123
	struct fuse_open_out outarg;
	struct fuse_file *ff;
	int err;

Miklos Szeredi's avatar
Miklos Szeredi committed
124
125
126
127
	/* VFS checks this, but only _after_ ->open() */
	if (file->f_flags & O_DIRECT)
		return -EINVAL;

128
129
130
131
	err = generic_file_open(inode, file);
	if (err)
		return err;

Tejun Heo's avatar
Tejun Heo committed
132
	ff = fuse_file_alloc(fc);
133
	if (!ff)
134
		return -ENOMEM;
135

136
137
138
139
140
141
142
	err = fuse_send_open(inode, file, isdir, &outarg);
	if (err)
		fuse_file_free(ff);
	else {
		if (isdir)
			outarg.open_flags &= ~FOPEN_DIRECT_IO;
		fuse_finish_open(inode, file, ff, &outarg);
143
144
145
146
147
	}

	return err;
}

148
void fuse_release_fill(struct fuse_file *ff, u64 nodeid, int flags, int opcode)
149
{
150
	struct fuse_req *req = ff->reserved_req;
151
	struct fuse_release_in *inarg = &req->misc.release.in;
152
153

	inarg->fh = ff->fh;
154
	inarg->flags = flags;
155
	req->in.h.opcode = opcode;
156
	req->in.h.nodeid = nodeid;
157
158
159
	req->in.numargs = 1;
	req->in.args[0].size = sizeof(struct fuse_release_in);
	req->in.args[0].value = inarg;
160
161
162
163
}

int fuse_release_common(struct inode *inode, struct file *file, int isdir)
{
Tejun Heo's avatar
Tejun Heo committed
164
165
166
	struct fuse_conn *fc;
	struct fuse_file *ff;
	struct fuse_req *req;
167

Tejun Heo's avatar
Tejun Heo committed
168
169
170
171
172
173
174
175
176
177
178
	ff = file->private_data;
	if (unlikely(!ff))
		return 0;	/* return value is ignored by VFS */

	fc = get_fuse_conn(inode);
	req = ff->reserved_req;

	fuse_release_fill(ff, get_node_id(inode), file->f_flags,
			  isdir ? FUSE_RELEASEDIR : FUSE_RELEASE);

	/* Hold vfsmount and dentry until release is finished */
179
180
	path_get(&file->f_path);
	req->misc.release.path = file->f_path;
Tejun Heo's avatar
Tejun Heo committed
181
182
183
184
185
186
187
188
189
190
191
192
193
194

	spin_lock(&fc->lock);
	list_del(&ff->write_entry);
	if (!RB_EMPTY_NODE(&ff->polled_node))
		rb_erase(&ff->polled_node, &fc->polled_files);
	spin_unlock(&fc->lock);

	wake_up_interruptible_sync(&ff->poll_wait);
	/*
	 * Normally this will send the RELEASE request, however if
	 * some asynchronous READ or WRITE requests are outstanding,
	 * the sending will be delayed.
	 */
	fuse_file_put(ff);
195
196
197
	return 0;
}

198
199
200
201
202
203
204
205
206
207
static int fuse_open(struct inode *inode, struct file *file)
{
	return fuse_open_common(inode, file, 0);
}

static int fuse_release(struct inode *inode, struct file *file)
{
	return fuse_release_common(inode, file, 0);
}

208
/*
209
210
 * Scramble the ID space with XTEA, so that the value of the files_struct
 * pointer is not exposed to userspace.
211
 */
212
u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id)
213
{
214
215
216
217
218
219
220
221
222
223
224
225
226
227
	u32 *k = fc->scramble_key;
	u64 v = (unsigned long) id;
	u32 v0 = v;
	u32 v1 = v >> 32;
	u32 sum = 0;
	int i;

	for (i = 0; i < 32; i++) {
		v0 += ((v1 << 4 ^ v1 >> 5) + v1) ^ (sum + k[sum & 3]);
		sum += 0x9E3779B9;
		v1 += ((v0 << 4 ^ v0 >> 5) + v0) ^ (sum + k[sum>>11 & 3]);
	}

	return (u64) v0 + ((u64) v1 << 32);
228
229
}

Miklos Szeredi's avatar
Miklos Szeredi committed
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
/*
 * Check if page is under writeback
 *
 * This is currently done by walking the list of writepage requests
 * for the inode, which can be pretty inefficient.
 */
static bool fuse_page_is_writeback(struct inode *inode, pgoff_t index)
{
	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_inode *fi = get_fuse_inode(inode);
	struct fuse_req *req;
	bool found = false;

	spin_lock(&fc->lock);
	list_for_each_entry(req, &fi->writepages, writepages_entry) {
		pgoff_t curr_index;

		BUG_ON(req->inode != inode);
		curr_index = req->misc.write.in.offset >> PAGE_CACHE_SHIFT;
		if (curr_index == index) {
			found = true;
			break;
		}
	}
	spin_unlock(&fc->lock);

	return found;
}

/*
 * Wait for page writeback to be completed.
 *
 * Since fuse doesn't rely on the VM writeback tracking, this has to
 * use some other means.
 */
static int fuse_wait_on_page_writeback(struct inode *inode, pgoff_t index)
{
	struct fuse_inode *fi = get_fuse_inode(inode);

	wait_event(fi->page_waitq, !fuse_page_is_writeback(inode, index));
	return 0;
}

273
static int fuse_flush(struct file *file, fl_owner_t id)
274
{
275
	struct inode *inode = file->f_path.dentry->d_inode;
276
277
278
279
280
281
	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_file *ff = file->private_data;
	struct fuse_req *req;
	struct fuse_flush_in inarg;
	int err;

282
283
284
	if (is_bad_inode(inode))
		return -EIO;

285
286
287
	if (fc->no_flush)
		return 0;

288
	req = fuse_get_req_nofail(fc, file);
289
290
	memset(&inarg, 0, sizeof(inarg));
	inarg.fh = ff->fh;
291
	inarg.lock_owner = fuse_lock_owner_id(fc, id);
292
293
294
295
296
	req->in.h.opcode = FUSE_FLUSH;
	req->in.h.nodeid = get_node_id(inode);
	req->in.numargs = 1;
	req->in.args[0].size = sizeof(inarg);
	req->in.args[0].value = &inarg;
297
	req->force = 1;
298
	fuse_request_send(fc, req);
299
300
301
302
303
304
305
306
307
	err = req->out.h.error;
	fuse_put_request(fc, req);
	if (err == -ENOSYS) {
		fc->no_flush = 1;
		err = 0;
	}
	return err;
}

Miklos Szeredi's avatar
Miklos Szeredi committed
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
/*
 * Wait for all pending writepages on the inode to finish.
 *
 * This is currently done by blocking further writes with FUSE_NOWRITE
 * and waiting for all sent writes to complete.
 *
 * This must be called under i_mutex, otherwise the FUSE_NOWRITE usage
 * could conflict with truncation.
 */
static void fuse_sync_writes(struct inode *inode)
{
	fuse_set_nowrite(inode);
	fuse_release_nowrite(inode);
}

323
324
int fuse_fsync_common(struct file *file, struct dentry *de, int datasync,
		      int isdir)
325
326
327
328
329
330
331
332
{
	struct inode *inode = de->d_inode;
	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_file *ff = file->private_data;
	struct fuse_req *req;
	struct fuse_fsync_in inarg;
	int err;

333
334
335
	if (is_bad_inode(inode))
		return -EIO;

336
	if ((!isdir && fc->no_fsync) || (isdir && fc->no_fsyncdir))
337
338
		return 0;

Miklos Szeredi's avatar
Miklos Szeredi committed
339
340
341
342
343
344
345
346
347
348
349
	/*
	 * Start writeback against all dirty pages of the inode, then
	 * wait for all outstanding writes, before sending the FSYNC
	 * request.
	 */
	err = write_inode_now(inode, 0);
	if (err)
		return err;

	fuse_sync_writes(inode);

350
351
352
	req = fuse_get_req(fc);
	if (IS_ERR(req))
		return PTR_ERR(req);
353
354
355
356

	memset(&inarg, 0, sizeof(inarg));
	inarg.fh = ff->fh;
	inarg.fsync_flags = datasync ? 1 : 0;
357
	req->in.h.opcode = isdir ? FUSE_FSYNCDIR : FUSE_FSYNC;
358
359
360
361
	req->in.h.nodeid = get_node_id(inode);
	req->in.numargs = 1;
	req->in.args[0].size = sizeof(inarg);
	req->in.args[0].value = &inarg;
362
	fuse_request_send(fc, req);
363
364
365
	err = req->out.h.error;
	fuse_put_request(fc, req);
	if (err == -ENOSYS) {
366
367
368
369
		if (isdir)
			fc->no_fsyncdir = 1;
		else
			fc->no_fsync = 1;
370
371
372
373
374
		err = 0;
	}
	return err;
}

375
376
377
378
379
static int fuse_fsync(struct file *file, struct dentry *de, int datasync)
{
	return fuse_fsync_common(file, de, datasync, 0);
}

380
void fuse_read_fill(struct fuse_req *req, struct file *file,
381
		    struct inode *inode, loff_t pos, size_t count, int opcode)
382
{
383
	struct fuse_read_in *inarg = &req->misc.read.in;
384
	struct fuse_file *ff = file->private_data;
385

386
387
388
	inarg->fh = ff->fh;
	inarg->offset = pos;
	inarg->size = count;
389
	inarg->flags = file->f_flags;
390
	req->in.h.opcode = opcode;
391
392
393
	req->in.h.nodeid = get_node_id(inode);
	req->in.numargs = 1;
	req->in.args[0].size = sizeof(struct fuse_read_in);
394
	req->in.args[0].value = inarg;
395
396
397
398
399
	req->out.argvar = 1;
	req->out.numargs = 1;
	req->out.args[0].size = count;
}

400
static size_t fuse_send_read(struct fuse_req *req, struct file *file,
401
402
			     struct inode *inode, loff_t pos, size_t count,
			     fl_owner_t owner)
403
{
404
	struct fuse_conn *fc = get_fuse_conn(inode);
405

406
	fuse_read_fill(req, file, inode, pos, count, FUSE_READ);
407
	if (owner != NULL) {
408
		struct fuse_read_in *inarg = &req->misc.read.in;
409
410
411
412

		inarg->read_flags |= FUSE_READ_LOCKOWNER;
		inarg->lock_owner = fuse_lock_owner_id(fc, owner);
	}
413
	fuse_request_send(fc, req);
414
	return req->out.args[0].size;
415
416
}

417
418
419
420
421
422
423
424
425
426
427
428
429
430
static void fuse_read_update_size(struct inode *inode, loff_t size,
				  u64 attr_ver)
{
	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_inode *fi = get_fuse_inode(inode);

	spin_lock(&fc->lock);
	if (attr_ver == fi->attr_version && size < inode->i_size) {
		fi->attr_version = ++fc->attr_version;
		i_size_write(inode, size);
	}
	spin_unlock(&fc->lock);
}

431
432
433
434
static int fuse_readpage(struct file *file, struct page *page)
{
	struct inode *inode = page->mapping->host;
	struct fuse_conn *fc = get_fuse_conn(inode);
435
	struct fuse_req *req;
436
437
438
439
	size_t num_read;
	loff_t pos = page_offset(page);
	size_t count = PAGE_CACHE_SIZE;
	u64 attr_ver;
440
441
442
443
444
445
	int err;

	err = -EIO;
	if (is_bad_inode(inode))
		goto out;

Miklos Szeredi's avatar
Miklos Szeredi committed
446
447
448
449
450
451
452
	/*
	 * Page writeback can extend beyond the liftime of the
	 * page-cache page, so make sure we read a properly synced
	 * page.
	 */
	fuse_wait_on_page_writeback(inode, page->index);

453
454
455
	req = fuse_get_req(fc);
	err = PTR_ERR(req);
	if (IS_ERR(req))
456
457
		goto out;

458
459
	attr_ver = fuse_get_attr_version(fc);

460
	req->out.page_zeroing = 1;
461
	req->out.argpages = 1;
462
463
	req->num_pages = 1;
	req->pages[0] = page;
464
	num_read = fuse_send_read(req, file, inode, pos, count, NULL);
465
466
	err = req->out.h.error;
	fuse_put_request(fc, req);
467
468
469
470
471
472
473
474

	if (!err) {
		/*
		 * Short read means EOF.  If file size is larger, truncate it
		 */
		if (num_read < count)
			fuse_read_update_size(inode, pos + num_read, attr_ver);

475
		SetPageUptodate(page);
476
477
	}

478
	fuse_invalidate_attr(inode); /* atime changed */
479
480
481
482
483
 out:
	unlock_page(page);
	return err;
}

484
static void fuse_readpages_end(struct fuse_conn *fc, struct fuse_req *req)
485
{
486
	int i;
487
488
489
	size_t count = req->misc.read.in.size;
	size_t num_read = req->out.args[0].size;
	struct inode *inode = req->pages[0]->mapping->host;
490

491
492
493
494
495
496
497
498
499
	/*
	 * Short read means EOF.  If file size is larger, truncate it
	 */
	if (!req->out.h.error && num_read < count) {
		loff_t pos = page_offset(req->pages[0]) + num_read;
		fuse_read_update_size(inode, pos, req->misc.read.attr_ver);
	}

	fuse_invalidate_attr(inode); /* atime changed */
500

501
502
503
504
	for (i = 0; i < req->num_pages; i++) {
		struct page *page = req->pages[i];
		if (!req->out.h.error)
			SetPageUptodate(page);
505
506
		else
			SetPageError(page);
507
508
		unlock_page(page);
	}
509
510
	if (req->ff)
		fuse_file_put(req->ff);
511
512
}

513
static void fuse_send_readpages(struct fuse_req *req, struct file *file,
514
515
516
517
518
				struct inode *inode)
{
	struct fuse_conn *fc = get_fuse_conn(inode);
	loff_t pos = page_offset(req->pages[0]);
	size_t count = req->num_pages << PAGE_CACHE_SHIFT;
519
520

	req->out.argpages = 1;
521
	req->out.page_zeroing = 1;
522
	fuse_read_fill(req, file, inode, pos, count, FUSE_READ);
523
	req->misc.read.attr_ver = fuse_get_attr_version(fc);
524
	if (fc->async_read) {
525
		struct fuse_file *ff = file->private_data;
526
		req->ff = fuse_file_get(ff);
527
		req->end = fuse_readpages_end;
528
		fuse_request_send_background(fc, req);
529
	} else {
530
		fuse_request_send(fc, req);
531
		fuse_readpages_end(fc, req);
532
		fuse_put_request(fc, req);
533
	}
534
535
}

536
struct fuse_fill_data {
537
	struct fuse_req *req;
538
	struct file *file;
539
540
541
542
543
	struct inode *inode;
};

static int fuse_readpages_fill(void *_data, struct page *page)
{
544
	struct fuse_fill_data *data = _data;
545
546
547
548
	struct fuse_req *req = data->req;
	struct inode *inode = data->inode;
	struct fuse_conn *fc = get_fuse_conn(inode);

Miklos Szeredi's avatar
Miklos Szeredi committed
549
550
	fuse_wait_on_page_writeback(inode, page->index);

551
552
553
554
	if (req->num_pages &&
	    (req->num_pages == FUSE_MAX_PAGES_PER_REQ ||
	     (req->num_pages + 1) * PAGE_CACHE_SIZE > fc->max_read ||
	     req->pages[req->num_pages - 1]->index + 1 != page->index)) {
555
		fuse_send_readpages(req, data->file, inode);
556
557
		data->req = req = fuse_get_req(fc);
		if (IS_ERR(req)) {
558
			unlock_page(page);
559
			return PTR_ERR(req);
560
561
562
		}
	}
	req->pages[req->num_pages] = page;
Miklos Szeredi's avatar
Miklos Szeredi committed
563
	req->num_pages++;
564
565
566
567
568
569
570
571
	return 0;
}

static int fuse_readpages(struct file *file, struct address_space *mapping,
			  struct list_head *pages, unsigned nr_pages)
{
	struct inode *inode = mapping->host;
	struct fuse_conn *fc = get_fuse_conn(inode);
572
	struct fuse_fill_data data;
573
	int err;
574

575
	err = -EIO;
576
	if (is_bad_inode(inode))
577
		goto out;
578

579
	data.file = file;
580
	data.inode = inode;
581
	data.req = fuse_get_req(fc);
582
	err = PTR_ERR(data.req);
583
	if (IS_ERR(data.req))
584
		goto out;
585
586

	err = read_cache_pages(mapping, pages, fuse_readpages_fill, &data);
587
588
	if (!err) {
		if (data.req->num_pages)
589
			fuse_send_readpages(data.req, file, inode);
590
591
592
		else
			fuse_put_request(fc, data.req);
	}
593
out:
594
	return err;
595
596
}

Miklos Szeredi's avatar
Miklos Szeredi committed
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
static ssize_t fuse_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
				  unsigned long nr_segs, loff_t pos)
{
	struct inode *inode = iocb->ki_filp->f_mapping->host;

	if (pos + iov_length(iov, nr_segs) > i_size_read(inode)) {
		int err;
		/*
		 * If trying to read past EOF, make sure the i_size
		 * attribute is up-to-date.
		 */
		err = fuse_update_attributes(inode, NULL, iocb->ki_filp, NULL);
		if (err)
			return err;
	}

	return generic_file_aio_read(iocb, iov, nr_segs, pos);
}

616
static void fuse_write_fill(struct fuse_req *req, struct file *file,
Miklos Szeredi's avatar
Miklos Szeredi committed
617
618
			    struct fuse_file *ff, struct inode *inode,
			    loff_t pos, size_t count, int writepage)
619
{
620
	struct fuse_conn *fc = get_fuse_conn(inode);
621
622
	struct fuse_write_in *inarg = &req->misc.write.in;
	struct fuse_write_out *outarg = &req->misc.write.out;
623

624
625
626
627
628
	memset(inarg, 0, sizeof(struct fuse_write_in));
	inarg->fh = ff->fh;
	inarg->offset = pos;
	inarg->size = count;
	inarg->write_flags = writepage ? FUSE_WRITE_CACHE : 0;
Miklos Szeredi's avatar
Miklos Szeredi committed
629
	inarg->flags = file ? file->f_flags : 0;
630
631
632
	req->in.h.opcode = FUSE_WRITE;
	req->in.h.nodeid = get_node_id(inode);
	req->in.numargs = 2;
633
634
635
636
	if (fc->minor < 9)
		req->in.args[0].size = FUSE_COMPAT_WRITE_IN_SIZE;
	else
		req->in.args[0].size = sizeof(struct fuse_write_in);
637
	req->in.args[0].value = inarg;
638
639
640
	req->in.args[1].size = count;
	req->out.numargs = 1;
	req->out.args[0].size = sizeof(struct fuse_write_out);
641
642
643
644
	req->out.args[0].value = outarg;
}

static size_t fuse_send_write(struct fuse_req *req, struct file *file,
645
646
			      struct inode *inode, loff_t pos, size_t count,
			      fl_owner_t owner)
647
648
{
	struct fuse_conn *fc = get_fuse_conn(inode);
Miklos Szeredi's avatar
Miklos Szeredi committed
649
	fuse_write_fill(req, file, file->private_data, inode, pos, count, 0);
650
651
652
653
654
	if (owner != NULL) {
		struct fuse_write_in *inarg = &req->misc.write.in;
		inarg->write_flags |= FUSE_WRITE_LOCKOWNER;
		inarg->lock_owner = fuse_lock_owner_id(fc, owner);
	}
655
	fuse_request_send(fc, req);
656
	return req->misc.write.out.size;
657
658
}

Nick Piggin's avatar
Nick Piggin committed
659
660
661
static int fuse_write_begin(struct file *file, struct address_space *mapping,
			loff_t pos, unsigned len, unsigned flags,
			struct page **pagep, void **fsdata)
662
{
Nick Piggin's avatar
Nick Piggin committed
663
664
	pgoff_t index = pos >> PAGE_CACHE_SHIFT;

665
	*pagep = grab_cache_page_write_begin(mapping, index, flags);
Nick Piggin's avatar
Nick Piggin committed
666
667
	if (!*pagep)
		return -ENOMEM;
668
669
670
	return 0;
}

671
672
673
674
675
676
677
678
679
680
681
682
static void fuse_write_update_size(struct inode *inode, loff_t pos)
{
	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_inode *fi = get_fuse_inode(inode);

	spin_lock(&fc->lock);
	fi->attr_version = ++fc->attr_version;
	if (pos > inode->i_size)
		i_size_write(inode, pos);
	spin_unlock(&fc->lock);
}

Nick Piggin's avatar
Nick Piggin committed
683
684
static int fuse_buffered_write(struct file *file, struct inode *inode,
			       loff_t pos, unsigned count, struct page *page)
685
686
{
	int err;
687
	size_t nres;
688
	struct fuse_conn *fc = get_fuse_conn(inode);
Nick Piggin's avatar
Nick Piggin committed
689
	unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
690
691
692
693
694
	struct fuse_req *req;

	if (is_bad_inode(inode))
		return -EIO;

Miklos Szeredi's avatar
Miklos Szeredi committed
695
696
697
698
699
700
	/*
	 * Make sure writepages on the same page are not mixed up with
	 * plain writes.
	 */
	fuse_wait_on_page_writeback(inode, page->index);

701
702
703
	req = fuse_get_req(fc);
	if (IS_ERR(req))
		return PTR_ERR(req);
704

705
	req->in.argpages = 1;
706
707
708
	req->num_pages = 1;
	req->pages[0] = page;
	req->page_offset = offset;
709
	nres = fuse_send_write(req, file, inode, pos, count, NULL);
710
711
	err = req->out.h.error;
	fuse_put_request(fc, req);
Nick Piggin's avatar
Nick Piggin committed
712
	if (!err && !nres)
713
714
		err = -EIO;
	if (!err) {
Nick Piggin's avatar
Nick Piggin committed
715
		pos += nres;
716
		fuse_write_update_size(inode, pos);
Nick Piggin's avatar
Nick Piggin committed
717
		if (count == PAGE_CACHE_SIZE)
718
			SetPageUptodate(page);
719
720
	}
	fuse_invalidate_attr(inode);
Nick Piggin's avatar
Nick Piggin committed
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
	return err ? err : nres;
}

static int fuse_write_end(struct file *file, struct address_space *mapping,
			loff_t pos, unsigned len, unsigned copied,
			struct page *page, void *fsdata)
{
	struct inode *inode = mapping->host;
	int res = 0;

	if (copied)
		res = fuse_buffered_write(file, inode, pos, copied, page);

	unlock_page(page);
	page_cache_release(page);
	return res;
737
738
}

Nick Piggin's avatar
Nick Piggin committed
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
static size_t fuse_send_write_pages(struct fuse_req *req, struct file *file,
				    struct inode *inode, loff_t pos,
				    size_t count)
{
	size_t res;
	unsigned offset;
	unsigned i;

	for (i = 0; i < req->num_pages; i++)
		fuse_wait_on_page_writeback(inode, req->pages[i]->index);

	res = fuse_send_write(req, file, inode, pos, count, NULL);

	offset = req->page_offset;
	count = res;
	for (i = 0; i < req->num_pages; i++) {
		struct page *page = req->pages[i];

		if (!req->out.h.error && !offset && count >= PAGE_CACHE_SIZE)
			SetPageUptodate(page);

		if (count > PAGE_CACHE_SIZE - offset)
			count -= PAGE_CACHE_SIZE - offset;
		else
			count = 0;
		offset = 0;

		unlock_page(page);
		page_cache_release(page);
	}

	return res;
}

static ssize_t fuse_fill_write_pages(struct fuse_req *req,
			       struct address_space *mapping,
			       struct iov_iter *ii, loff_t pos)
{
	struct fuse_conn *fc = get_fuse_conn(mapping->host);
	unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
	size_t count = 0;
	int err;

782
	req->in.argpages = 1;
Nick Piggin's avatar
Nick Piggin committed
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
	req->page_offset = offset;

	do {
		size_t tmp;
		struct page *page;
		pgoff_t index = pos >> PAGE_CACHE_SHIFT;
		size_t bytes = min_t(size_t, PAGE_CACHE_SIZE - offset,
				     iov_iter_count(ii));

		bytes = min_t(size_t, bytes, fc->max_write - count);

 again:
		err = -EFAULT;
		if (iov_iter_fault_in_readable(ii, bytes))
			break;

		err = -ENOMEM;
800
		page = grab_cache_page_write_begin(mapping, index, 0);
Nick Piggin's avatar
Nick Piggin committed
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
		if (!page)
			break;

		pagefault_disable();
		tmp = iov_iter_copy_from_user_atomic(page, ii, offset, bytes);
		pagefault_enable();
		flush_dcache_page(page);

		if (!tmp) {
			unlock_page(page);
			page_cache_release(page);
			bytes = min(bytes, iov_iter_single_seg_count(ii));
			goto again;
		}

		err = 0;
		req->pages[req->num_pages] = page;
		req->num_pages++;

		iov_iter_advance(ii, tmp);
		count += tmp;
		pos += tmp;
		offset += tmp;
		if (offset == PAGE_CACHE_SIZE)
			offset = 0;

827
828
		if (!fc->big_writes)
			break;
Nick Piggin's avatar
Nick Piggin committed
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
	} while (iov_iter_count(ii) && count < fc->max_write &&
		 req->num_pages < FUSE_MAX_PAGES_PER_REQ && offset == 0);

	return count > 0 ? count : err;
}

static ssize_t fuse_perform_write(struct file *file,
				  struct address_space *mapping,
				  struct iov_iter *ii, loff_t pos)
{
	struct inode *inode = mapping->host;
	struct fuse_conn *fc = get_fuse_conn(inode);
	int err = 0;
	ssize_t res = 0;

	if (is_bad_inode(inode))
		return -EIO;

	do {
		struct fuse_req *req;
		ssize_t count;

		req = fuse_get_req(fc);
		if (IS_ERR(req)) {
			err = PTR_ERR(req);
			break;
		}

		count = fuse_fill_write_pages(req, mapping, ii, pos);
		if (count <= 0) {
			err = count;
		} else {
			size_t num_written;

			num_written = fuse_send_write_pages(req, file, inode,
							    pos, count);
			err = req->out.h.error;
			if (!err) {
				res += num_written;
				pos += num_written;

				/* break out of the loop on short write */
				if (num_written != count)
					err = -EIO;
			}
		}
		fuse_put_request(fc, req);
	} while (!err && iov_iter_count(ii));

	if (res > 0)
		fuse_write_update_size(inode, pos);

	fuse_invalidate_attr(inode);

	return res > 0 ? res : err;
}

static ssize_t fuse_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
				   unsigned long nr_segs, loff_t pos)
{
	struct file *file = iocb->ki_filp;
	struct address_space *mapping = file->f_mapping;
	size_t count = 0;
	ssize_t written = 0;
	struct inode *inode = mapping->host;
	ssize_t err;
	struct iov_iter i;

	WARN_ON(iocb->ki_pos != pos);

	err = generic_segment_checks(iov, &nr_segs, &count, VERIFY_READ);
	if (err)
		return err;

	mutex_lock(&inode->i_mutex);
	vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);

	/* We can write back this queue in page reclaim */
	current->backing_dev_info = mapping->backing_dev_info;

	err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
	if (err)
		goto out;

	if (count == 0)
		goto out;

916
	err = file_remove_suid(file);
Nick Piggin's avatar
Nick Piggin committed
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
	if (err)
		goto out;

	file_update_time(file);

	iov_iter_init(&i, iov, nr_segs, count, 0);
	written = fuse_perform_write(file, mapping, &i, pos);
	if (written >= 0)
		iocb->ki_pos = pos + written;

out:
	current->backing_dev_info = NULL;
	mutex_unlock(&inode->i_mutex);

	return written ? written : err;
}

Miklos Szeredi's avatar
Miklos Szeredi committed
934
935
936
937
938
939
940
941
942
943
944
945
946
static void fuse_release_user_pages(struct fuse_req *req, int write)
{
	unsigned i;

	for (i = 0; i < req->num_pages; i++) {
		struct page *page = req->pages[i];
		if (write)
			set_page_dirty_lock(page);
		put_page(page);
	}
}

static int fuse_get_user_pages(struct fuse_req *req, const char __user *buf,
947
			       size_t *nbytesp, int write)
Miklos Szeredi's avatar
Miklos Szeredi committed
948
{
949
	size_t nbytes = *nbytesp;
Miklos Szeredi's avatar
Miklos Szeredi committed
950
951
952
953
	unsigned long user_addr = (unsigned long) buf;
	unsigned offset = user_addr & ~PAGE_MASK;
	int npages;

954
955
956
957
958
959
960
961
962
	/* Special case for kernel I/O: can copy directly into the buffer */
	if (segment_eq(get_fs(), KERNEL_DS)) {
		if (write)
			req->in.args[1].value = (void *) user_addr;
		else
			req->out.args[0].value = (void *) user_addr;

		return 0;
	}
Miklos Szeredi's avatar
Miklos Szeredi committed
963

964
	nbytes = min_t(size_t, nbytes, FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT);
Miklos Szeredi's avatar
Miklos Szeredi committed
965
	npages = (nbytes + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
966
	npages = clamp(npages, 1, FUSE_MAX_PAGES_PER_REQ);
Miklos Szeredi's avatar
Miklos Szeredi committed
967
	down_read(&current->mm->mmap_sem);
968
	npages = get_user_pages(current, current->mm, user_addr, npages, !write,
Miklos Szeredi's avatar
Miklos Szeredi committed
969
970
971
972
973
974
975
				0, req->pages, NULL);
	up_read(&current->mm->mmap_sem);
	if (npages < 0)
		return npages;

	req->num_pages = npages;
	req->page_offset = offset;
976
977
978
979
980
981
982
983
984

	if (write)
		req->in.argpages = 1;
	else
		req->out.argpages = 1;

	nbytes = (req->num_pages << PAGE_SHIFT) - req->page_offset;
	*nbytesp = min(*nbytesp, nbytes);

Miklos Szeredi's avatar
Miklos Szeredi committed
985
986
987
988
989
990
	return 0;
}

static ssize_t fuse_direct_io(struct file *file, const char __user *buf,
			      size_t count, loff_t *ppos, int write)
{
991
	struct inode *inode = file->f_path.dentry->d_inode;
Miklos Szeredi's avatar
Miklos Szeredi committed
992
993
994
995
	struct fuse_conn *fc = get_fuse_conn(inode);
	size_t nmax = write ? fc->max_write : fc->max_read;
	loff_t pos = *ppos;
	ssize_t res = 0;
996
997
998
999
1000
	struct fuse_req *req;

	if (is_bad_inode(inode))
		return -EIO;

1001
1002
1003
	req = fuse_get_req(fc);
	if (IS_ERR(req))
		return PTR_ERR(req);
Miklos Szeredi's avatar
Miklos Szeredi committed
1004
1005
1006

	while (count) {
		size_t nres;
1007
1008
		size_t nbytes = min(count, nmax);
		int err = fuse_get_user_pages(req, buf, &nbytes, write);
Miklos Szeredi's avatar
Miklos Szeredi committed
1009
1010
1011
1012
		if (err) {
			res = err;
			break;
		}
1013

Miklos Szeredi's avatar
Miklos Szeredi committed
1014
		if (write)
1015
1016
			nres = fuse_send_write(req, file, inode, pos, nbytes,
					       current->files);
Miklos Szeredi's avatar
Miklos Szeredi committed
1017
		else
1018
1019
			nres = fuse_send_read(req, file, inode, pos, nbytes,
					      current->files);
Miklos Szeredi's avatar
Miklos Szeredi committed
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
		fuse_release_user_pages(req, !write);
		if (req->out.h.error) {
			if (!res)
				res = req->out.h.error;
			break;
		} else if (nres > nbytes) {
			res = -EIO;
			break;
		}
		count -= nres;
		res += nres;
		pos += nres;
		buf += nres;
		if (nres != nbytes)
			break;
1035
1036
1037
1038
1039
1040
		if (count) {
			fuse_put_request(fc, req);
			req = fuse_get_req(fc);
			if (IS_ERR(req))
				break;
		}
Miklos Szeredi's avatar
Miklos Szeredi committed
1041
1042
1043
	}
	fuse_put_request(fc, req);
	if (res > 0) {
1044
1045
		if (write)
			fuse_write_update_size(inode, pos);
Miklos Szeredi's avatar
Miklos Szeredi committed
1046
		*ppos = pos;
1047
1048
	}
	fuse_invalidate_attr(inode);
Miklos Szeredi's avatar
Miklos Szeredi committed
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061

	return res;
}

static ssize_t fuse_direct_read(struct file *file, char __user *buf,
				     size_t count, loff_t *ppos)
{
	return fuse_direct_io(file, buf, count, ppos, 0);
}

static ssize_t fuse_direct_write(struct file *file, const char __user *buf,
				 size_t count, loff_t *ppos)
{
1062
	struct inode *inode = file->f_path.dentry->d_inode;
Miklos Szeredi's avatar
Miklos Szeredi committed
1063
1064
	ssize_t res;
	/* Don't allow parallel writes to the same file */
1065
	mutex_lock(&inode->i_mutex);
1066
1067
1068
	res = generic_write_checks(file, ppos, &count, 0);
	if (!res)
		res = fuse_direct_io(file, buf, count, ppos, 1);
1069
	mutex_unlock(&inode->i_mutex);
Miklos Szeredi's avatar
Miklos Szeredi committed
1070
1071
1072
	return res;
}

Miklos Szeredi's avatar
Miklos Szeredi committed
1073
static void fuse_writepage_free(struct fuse_conn *fc, struct fuse_req *req)
1074
{
Miklos Szeredi's avatar
Miklos Szeredi committed
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
	__free_page(req->pages[0]);
	fuse_file_put(req->ff);
}

static void fuse_writepage_finish(struct fuse_conn *fc, struct fuse_req *req)
{
	struct inode *inode = req->inode;
	struct fuse_inode *fi = get_fuse_inode(inode);
	struct backing_dev_info *bdi = inode->i_mapping->backing_dev_info;

	list_del(&req->writepages_entry);
	dec_bdi_stat(bdi, BDI_WRITEBACK);
	dec_zone_page_state(req->pages[0], NR_WRITEBACK_TEMP);
	bdi_writeout_inc(bdi);
	wake_up(&fi->page_waitq);
}

/* Called under fc->lock, may release and reacquire it */
static void fuse_send_writepage(struct fuse_conn *fc, struct fuse_req *req)
1094
1095
__releases(&fc->lock)
__acquires(&fc->lock)
Miklos Szeredi's avatar
Miklos Szeredi committed
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
{
	struct fuse_inode *fi = get_fuse_inode(req->inode);
	loff_t size = i_size_read(req->inode);
	struct fuse_write_in *inarg = &req->misc.write.in;

	if (!fc->connected)
		goto out_free;

	if (inarg->offset + PAGE_CACHE_SIZE <= size) {
		inarg->size = PAGE_CACHE_SIZE;
	} else if (inarg->offset < size) {
		inarg->size = size & (PAGE_CACHE_SIZE - 1);
	} else {
		/* Got truncated off completely */
		goto out_free;
1111
	}
Miklos Szeredi's avatar
Miklos Szeredi committed
1112
1113
1114

	req->in.args[1].size = inarg->size;
	fi->writectr++;
1115
	fuse_request_send_background_locked(fc, req);
Miklos Szeredi's avatar
Miklos Szeredi committed
1116
1117
1118
1119
1120
1121
	return;

 out_free:
	fuse_writepage_finish(fc, req);
	spin_unlock(&fc->lock);
	fuse_writepage_free(fc, req);
1122
	fuse_put_request(fc, req);
Miklos Szeredi's avatar
Miklos Szeredi committed
1123
	spin_lock(&fc->lock);
1124
1125
}

Miklos Szeredi's avatar
Miklos Szeredi committed
1126
1127
1128
1129
1130
1131
1132
/*
 * If fi->writectr is positive (no truncate or fsync going on) send
 * all queued writepage requests.
 *
 * Called with fc->lock
 */
void fuse_flush_writepages(struct inode *inode)
1133
1134
__releases(&fc->lock)
__acquires(&fc->lock)
1135
{
Miklos Szeredi's avatar
Miklos Szeredi committed
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_inode *fi = get_fuse_inode(inode);
	struct fuse_req *req;

	while (fi->writectr >= 0 && !list_empty(&fi->queued_writes)) {
		req = list_entry(fi->queued_writes.next, struct fuse_req, list);
		list_del_init(&req->list);
		fuse_send_writepage(fc, req);
	}
}

static void fuse_writepage_end(struct fuse_conn *fc, struct fuse_req *req)
{
	struct inode *inode = req->inode;
	struct fuse_inode *fi = get_fuse_inode(inode);

	mapping_set_error(inode->i_mapping, req->out.h.error);
	spin_lock(&fc->lock);
	fi->writectr--;
	fuse_writepage_finish(fc, req);
	spin_unlock(&fc->lock);
	fuse_writepage_free(fc, req);
}

static int fuse_writepage_locked(struct page *page)
{
	struct address_space *mapping = page->mapping;
	struct inode *inode = mapping->host;
	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_inode *fi = get_fuse_inode(inode);
	struct fuse_req *req;
	struct fuse_file *ff;
	struct page *tmp_page;

	set_page_writeback(page);

	req = fuse_request_alloc_nofs();
	if (!req)
		goto err;

	tmp_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
	if (!tmp_page)
		goto err_free;

	spin_lock(&fc->lock);
	BUG_ON(list_empty(&fi->write_files));
	ff = list_entry(fi->write_files.next, struct fuse_file, write_entry);
	req->ff = fuse_file_get(ff);
	spin_unlock(&fc->lock);

	fuse_write_fill(req, NULL, ff, inode, page_offset(page), 0, 1);

	copy_highpage(tmp_page, page);
1189
	req->in.argpages = 1;
Miklos Szeredi's avatar
Miklos Szeredi committed
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
	req->num_pages = 1;
	req->pages[0] = tmp_page;
	req->page_offset = 0;
	req->end = fuse_writepage_end;
	req->inode = inode;

	inc_bdi_stat(mapping->backing_dev_info, BDI_WRITEBACK);
	inc_zone_page_state(tmp_page, NR_WRITEBACK_TEMP);
	end_page_writeback(page);

	spin_lock(&fc->lock);
	list_add(&req->writepages_entry, &fi->writepages);
	list_add_tail(&req->list, &fi->queued_writes);
	fuse_flush_writepages(inode);
	spin_unlock(&fc->lock);

	return 0;

err_free:
	fuse_request_free(req);
err:
	end_page_writeback(page);
	return -ENOMEM;
}

static int fuse_writepage(struct page *page, struct writeback_control *wbc)
{
	int err;

	err = fuse_writepage_locked(page);
	unlock_page(page);

	return err;
}

static int fuse_launder_page(struct page *page)
{
	int err = 0;
	if (clear_page_dirty_for_io(page)) {
		struct inode *inode = page->mapping->host;
		err = fuse_writepage_locked(page);
		if (!err)
			fuse_wait_on_page_writeback(inode, page->index);
	}
	return err;
}

/*
 * Write back dirty pages now, because there may not be any suitable
 * open files later
 */
static void fuse_vma_close(struct vm_area_struct *vma)
{
	filemap_write_and_wait(vma->vm_file->f_mapping);
}

/*
 * Wait for writeback against this page to complete before allowing it
 * to be marked dirty again, and hence written back again, possibly
 * before the previous writepage completed.
 *
 * Block here, instead of in ->writepage(), so that the userspace fs
 * can only block processes actually operating on the filesystem.
 *
 * Otherwise unprivileged userspace fs would be able to block
 * unrelated:
 *
 * - page migration
 * - sync(2)
 * - try_to_free_pages() with order > PAGE_ALLOC_COSTLY_ORDER
 */
1261
static int fuse_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
Miklos Szeredi's avatar
Miklos Szeredi committed
1262
{
1263
	struct page *page = vmf->page;
Miklos Szeredi's avatar
Miklos Szeredi committed
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
	/*
	 * Don't use page->mapping as it may become NULL from a
	 * concurrent truncate.
	 */
	struct inode *inode = vma->vm_file->f_mapping->host;

	fuse_wait_on_page_writeback(inode, page->index);
	return 0;
}

static struct vm_operations_struct fuse_file_vm_ops = {
	.close		= fuse_vma_close,
	.fault		= filemap_fault,
	.page_mkwrite	= fuse_page_mkwrite,
};

static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma)
{
	if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_MAYWRITE)) {
		struct inode *inode = file->f_dentry->d_inode;
		struct fuse_conn *fc = get_fuse_conn(inode);
		struct fuse_inode *fi = get_fuse_inode(inode);
		struct fuse_file *ff = file->private_data;
		/*
		 * file may be written through mmap, so chain it onto the
		 * inodes's write_file list
		 */
		spin_lock(&fc->lock);
		if (list_empty(&ff->write_entry))
			list_add(&ff->write_entry, &fi->write_files);
		spin_unlock(&fc->lock);
	}
	file_accessed(file);
	vma->vm_ops = &fuse_file_vm_ops;
1298
1299
1300
	return 0;
}

1301
1302
1303
1304
1305
1306
static int fuse_direct_mmap(struct file *file, struct vm_area_struct *vma)
{
	/* Can't provide the coherency needed for MAP_SHARED */
	if (vma->vm_flags & VM_MAYSHARE)
		return -ENODEV;

1307
1308
	invalidate_inode_pages2(file->f_mapping);

1309
1310
1311
	return generic_file_mmap(file, vma);
}

1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
static int convert_fuse_file_lock(const struct fuse_file_lock *ffl,
				  struct file_lock *fl)
{
	switch (ffl->type) {
	case F_UNLCK:
		break;

	case F_RDLCK:
	case F_WRLCK:
		if (ffl->start > OFFSET_MAX || ffl->end > OFFSET_MAX ||
		    ffl->end < ffl->start)
			return -EIO;

		fl->fl_start = ffl->start;
		fl->fl_end = ffl->end;
		fl->fl_pid = ffl->pid;
		break;

	default:
		return -EIO;
	}
	fl->fl_type = ffl->type;
	return 0;
}

static void fuse_lk_fill(struct fuse_req *req, struct file *file,
1338
1339
			 const struct file_lock *fl, int opcode, pid_t pid,
			 int flock)
1340
{
1341
	struct inode *inode = file->f_path.dentry->d_inode;
1342
	struct fuse_conn *fc = get_fuse_conn(inode);
1343
1344
1345
1346
	struct fuse_file *ff = file->private_data;
	struct fuse_lk_in *arg = &req->misc.lk_in;

	arg->fh = ff->fh;
1347
	arg->owner = fuse_lock_owner_id(fc, fl->fl_owner);
1348
1349
1350
1351
	arg->lk.start = fl->fl_start;
	arg->lk.end = fl->fl_end;
	arg->lk.type = fl->fl_type;
	arg->lk.pid = pid;
1352
1353
	if (flock)
		arg->lk_flags |= FUSE_LK_FLOCK;
1354
1355
1356
1357
1358
1359
1360
1361
1362
	req->in.h.opcode = opcode;
	req->in.h.nodeid = get_node_id(inode);
	req->in.numargs = 1;
	req->in.args[0].size = sizeof(*arg);
	req->in.args[0].value = arg;
}

static int fuse_getlk(struct file *file, struct file_lock *fl)
{
1363
	struct inode *inode = file->f_path.dentry->d_inode;
1364
1365
1366
1367
1368
1369
1370
1371
1372
	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_req *req;
	struct fuse_lk_out outarg;
	int err;

	req = fuse_get_req(fc);
	if (IS_ERR(req))
		return PTR_ERR(req);

1373
	fuse_lk_fill(req, file, fl, FUSE_GETLK, 0, 0);
1374
1375
1376
	req->out.numargs = 1;
	req->out.args[0].size = sizeof(outarg);
	req->out.args[0].value = &outarg;
1377
	fuse_request_send(fc, req);
1378
1379
1380
1381
1382
1383
1384
1385
	err = req->out.h.error;
	fuse_put_request(fc, req);
	if (!err)
		err = convert_fuse_file_lock(&outarg.lk, fl);

	return err;
}