file.c 47.8 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
	if (unlikely(!ff))
		return NULL;

57
	ff->fc = fc;
Tejun Heo's avatar
Tejun Heo committed
58
59
60
61
	ff->reserved_req = fuse_request_alloc();
	if (unlikely(!ff->reserved_req)) {
		kfree(ff);
		return NULL;
62
	}
Tejun Heo's avatar
Tejun Heo committed
63
64
65
66
67
68
69
70
71
72

	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);

73
74
75
76
77
	return ff;
}

void fuse_file_free(struct fuse_file *ff)
{
78
	fuse_request_free(ff->reserved_req);
79
80
81
	kfree(ff);
}

82
83
84
85
86
87
static struct fuse_file *fuse_file_get(struct fuse_file *ff)
{
	atomic_inc(&ff->count);
	return ff;
}

Miklos Szeredi's avatar
Miklos Szeredi committed
88
89
static void fuse_release_end(struct fuse_conn *fc, struct fuse_req *req)
{
90
	path_put(&req->misc.release.path);
Miklos Szeredi's avatar
Miklos Szeredi committed
91
92
}

93
94
95
96
static void fuse_file_put(struct fuse_file *ff)
{
	if (atomic_dec_and_test(&ff->count)) {
		struct fuse_req *req = ff->reserved_req;
97
		struct inode *inode = req->misc.release.path.dentry->d_inode;
98
		struct fuse_conn *fc = get_fuse_conn(inode);
Miklos Szeredi's avatar
Miklos Szeredi committed
99
		req->end = fuse_release_end;
100
		fuse_request_send_background(fc, req);
101
102
103
104
		kfree(ff);
	}
}

105
106
107
108
109
110
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
111
		invalidate_inode_pages2(inode->i_mapping);
Tejun Heo's avatar
Tejun Heo committed
112
113
	if (outarg->open_flags & FOPEN_NONSEEKABLE)
		nonseekable_open(inode, file);
114
	ff->fh = outarg->fh;
115
	ff->nodeid = get_node_id(inode);
116
	file->private_data = fuse_file_get(ff);
117
118
119
120
}

int fuse_open_common(struct inode *inode, struct file *file, int isdir)
{
Tejun Heo's avatar
Tejun Heo committed
121
	struct fuse_conn *fc = get_fuse_conn(inode);
122
123
124
125
	struct fuse_open_out outarg;
	struct fuse_file *ff;
	int err;

Miklos Szeredi's avatar
Miklos Szeredi committed
126
127
128
129
	/* VFS checks this, but only _after_ ->open() */
	if (file->f_flags & O_DIRECT)
		return -EINVAL;

130
131
132
133
	err = generic_file_open(inode, file);
	if (err)
		return err;

Tejun Heo's avatar
Tejun Heo committed
134
	ff = fuse_file_alloc(fc);
135
	if (!ff)
136
		return -ENOMEM;
137

138
139
140
141
142
143
144
	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);
145
146
147
148
149
	}

	return err;
}

150
void fuse_release_fill(struct fuse_file *ff, u64 nodeid, int flags, int opcode)
151
{
152
	struct fuse_req *req = ff->reserved_req;
153
	struct fuse_release_in *inarg = &req->misc.release.in;
154
155

	inarg->fh = ff->fh;
156
	inarg->flags = flags;
157
	req->in.h.opcode = opcode;
158
	req->in.h.nodeid = nodeid;
159
160
161
	req->in.numargs = 1;
	req->in.args[0].size = sizeof(struct fuse_release_in);
	req->in.args[0].value = inarg;
162
163
164
165
}

int fuse_release_common(struct inode *inode, struct file *file, int isdir)
{
Tejun Heo's avatar
Tejun Heo committed
166
167
168
	struct fuse_conn *fc;
	struct fuse_file *ff;
	struct fuse_req *req;
169

Tejun Heo's avatar
Tejun Heo committed
170
171
172
173
174
175
176
177
178
179
180
	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 */
181
182
	path_get(&file->f_path);
	req->misc.release.path = file->f_path;
Tejun Heo's avatar
Tejun Heo committed
183
184
185
186
187
188
189
190
191
192
193
194
195
196

	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);
197
198
199
	return 0;
}

200
201
202
203
204
205
206
207
208
209
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);
}

210
/*
211
212
 * Scramble the ID space with XTEA, so that the value of the files_struct
 * pointer is not exposed to userspace.
213
 */
214
u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id)
215
{
216
217
218
219
220
221
222
223
224
225
226
227
228
229
	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);
230
231
}

Miklos Szeredi's avatar
Miklos Szeredi committed
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
273
274
/*
 * 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;
}

275
static int fuse_flush(struct file *file, fl_owner_t id)
276
{
277
	struct inode *inode = file->f_path.dentry->d_inode;
278
279
280
281
282
283
	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;

284
285
286
	if (is_bad_inode(inode))
		return -EIO;

287
288
289
	if (fc->no_flush)
		return 0;

290
	req = fuse_get_req_nofail(fc, file);
291
292
	memset(&inarg, 0, sizeof(inarg));
	inarg.fh = ff->fh;
293
	inarg.lock_owner = fuse_lock_owner_id(fc, id);
294
295
296
297
298
	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;
299
	req->force = 1;
300
	fuse_request_send(fc, req);
301
302
303
304
305
306
307
308
309
	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
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
/*
 * 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);
}

325
326
int fuse_fsync_common(struct file *file, struct dentry *de, int datasync,
		      int isdir)
327
328
329
330
331
332
333
334
{
	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;

335
336
337
	if (is_bad_inode(inode))
		return -EIO;

338
	if ((!isdir && fc->no_fsync) || (isdir && fc->no_fsyncdir))
339
340
		return 0;

Miklos Szeredi's avatar
Miklos Szeredi committed
341
342
343
344
345
346
347
348
349
350
351
	/*
	 * 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);

352
353
354
	req = fuse_get_req(fc);
	if (IS_ERR(req))
		return PTR_ERR(req);
355
356
357
358

	memset(&inarg, 0, sizeof(inarg));
	inarg.fh = ff->fh;
	inarg.fsync_flags = datasync ? 1 : 0;
359
	req->in.h.opcode = isdir ? FUSE_FSYNCDIR : FUSE_FSYNC;
360
361
362
363
	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;
364
	fuse_request_send(fc, req);
365
366
367
	err = req->out.h.error;
	fuse_put_request(fc, req);
	if (err == -ENOSYS) {
368
369
370
371
		if (isdir)
			fc->no_fsyncdir = 1;
		else
			fc->no_fsync = 1;
372
373
374
375
376
		err = 0;
	}
	return err;
}

377
378
379
380
381
static int fuse_fsync(struct file *file, struct dentry *de, int datasync)
{
	return fuse_fsync_common(file, de, datasync, 0);
}

382
void fuse_read_fill(struct fuse_req *req, struct file *file,
383
		    struct inode *inode, loff_t pos, size_t count, int opcode)
384
{
385
	struct fuse_read_in *inarg = &req->misc.read.in;
386
	struct fuse_file *ff = file->private_data;
387

388
389
390
	inarg->fh = ff->fh;
	inarg->offset = pos;
	inarg->size = count;
391
	inarg->flags = file->f_flags;
392
	req->in.h.opcode = opcode;
393
394
395
	req->in.h.nodeid = get_node_id(inode);
	req->in.numargs = 1;
	req->in.args[0].size = sizeof(struct fuse_read_in);
396
	req->in.args[0].value = inarg;
397
398
399
400
401
	req->out.argvar = 1;
	req->out.numargs = 1;
	req->out.args[0].size = count;
}

402
static size_t fuse_send_read(struct fuse_req *req, struct file *file,
403
404
			     struct inode *inode, loff_t pos, size_t count,
			     fl_owner_t owner)
405
{
406
	struct fuse_conn *fc = get_fuse_conn(inode);
407

408
	fuse_read_fill(req, file, inode, pos, count, FUSE_READ);
409
	if (owner != NULL) {
410
		struct fuse_read_in *inarg = &req->misc.read.in;
411
412
413
414

		inarg->read_flags |= FUSE_READ_LOCKOWNER;
		inarg->lock_owner = fuse_lock_owner_id(fc, owner);
	}
415
	fuse_request_send(fc, req);
416
	return req->out.args[0].size;
417
418
}

419
420
421
422
423
424
425
426
427
428
429
430
431
432
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);
}

433
434
435
436
static int fuse_readpage(struct file *file, struct page *page)
{
	struct inode *inode = page->mapping->host;
	struct fuse_conn *fc = get_fuse_conn(inode);
437
	struct fuse_req *req;
438
439
440
441
	size_t num_read;
	loff_t pos = page_offset(page);
	size_t count = PAGE_CACHE_SIZE;
	u64 attr_ver;
442
443
444
445
446
447
	int err;

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

Miklos Szeredi's avatar
Miklos Szeredi committed
448
449
450
451
452
453
454
	/*
	 * 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);

455
456
457
	req = fuse_get_req(fc);
	err = PTR_ERR(req);
	if (IS_ERR(req))
458
459
		goto out;

460
461
	attr_ver = fuse_get_attr_version(fc);

462
	req->out.page_zeroing = 1;
463
	req->out.argpages = 1;
464
465
	req->num_pages = 1;
	req->pages[0] = page;
466
	num_read = fuse_send_read(req, file, inode, pos, count, NULL);
467
468
	err = req->out.h.error;
	fuse_put_request(fc, req);
469
470
471
472
473
474
475
476

	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);

477
		SetPageUptodate(page);
478
479
	}

480
	fuse_invalidate_attr(inode); /* atime changed */
481
482
483
484
485
 out:
	unlock_page(page);
	return err;
}

486
static void fuse_readpages_end(struct fuse_conn *fc, struct fuse_req *req)
487
{
488
	int i;
489
490
491
	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;
492

493
494
495
496
497
498
499
500
501
	/*
	 * 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 */
502

503
504
505
506
	for (i = 0; i < req->num_pages; i++) {
		struct page *page = req->pages[i];
		if (!req->out.h.error)
			SetPageUptodate(page);
507
508
		else
			SetPageError(page);
509
510
		unlock_page(page);
	}
511
512
	if (req->ff)
		fuse_file_put(req->ff);
513
514
}

515
static void fuse_send_readpages(struct fuse_req *req, struct file *file,
516
517
518
519
520
				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;
521
522

	req->out.argpages = 1;
523
	req->out.page_zeroing = 1;
524
	fuse_read_fill(req, file, inode, pos, count, FUSE_READ);
525
	req->misc.read.attr_ver = fuse_get_attr_version(fc);
526
	if (fc->async_read) {
527
		struct fuse_file *ff = file->private_data;
528
		req->ff = fuse_file_get(ff);
529
		req->end = fuse_readpages_end;
530
		fuse_request_send_background(fc, req);
531
	} else {
532
		fuse_request_send(fc, req);
533
		fuse_readpages_end(fc, req);
534
		fuse_put_request(fc, req);
535
	}
536
537
}

538
struct fuse_fill_data {
539
	struct fuse_req *req;
540
	struct file *file;
541
542
543
544
545
	struct inode *inode;
};

static int fuse_readpages_fill(void *_data, struct page *page)
{
546
	struct fuse_fill_data *data = _data;
547
548
549
550
	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
551
552
	fuse_wait_on_page_writeback(inode, page->index);

553
554
555
556
	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)) {
557
		fuse_send_readpages(req, data->file, inode);
558
559
		data->req = req = fuse_get_req(fc);
		if (IS_ERR(req)) {
560
			unlock_page(page);
561
			return PTR_ERR(req);
562
563
564
		}
	}
	req->pages[req->num_pages] = page;
Miklos Szeredi's avatar
Miklos Szeredi committed
565
	req->num_pages++;
566
567
568
569
570
571
572
573
	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);
574
	struct fuse_fill_data data;
575
	int err;
576

577
	err = -EIO;
578
	if (is_bad_inode(inode))
579
		goto out;
580

581
	data.file = file;
582
	data.inode = inode;
583
	data.req = fuse_get_req(fc);
584
	err = PTR_ERR(data.req);
585
	if (IS_ERR(data.req))
586
		goto out;
587
588

	err = read_cache_pages(mapping, pages, fuse_readpages_fill, &data);
589
590
	if (!err) {
		if (data.req->num_pages)
591
			fuse_send_readpages(data.req, file, inode);
592
593
594
		else
			fuse_put_request(fc, data.req);
	}
595
out:
596
	return err;
597
598
}

Miklos Szeredi's avatar
Miklos Szeredi committed
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
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);
}

618
619
static void fuse_write_fill(struct fuse_req *req, struct fuse_file *ff,
			    struct inode *inode, loff_t pos, size_t count)
620
{
621
	struct fuse_conn *fc = get_fuse_conn(inode);
622
623
	struct fuse_write_in *inarg = &req->misc.write.in;
	struct fuse_write_out *outarg = &req->misc.write.out;
624

625
626
627
	inarg->fh = ff->fh;
	inarg->offset = pos;
	inarg->size = count;
628
629
630
	req->in.h.opcode = FUSE_WRITE;
	req->in.h.nodeid = get_node_id(inode);
	req->in.numargs = 2;
631
632
633
634
	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);
635
	req->in.args[0].value = inarg;
636
637
638
	req->in.args[1].size = count;
	req->out.numargs = 1;
	req->out.args[0].size = sizeof(struct fuse_write_out);
639
640
641
642
	req->out.args[0].value = outarg;
}

static size_t fuse_send_write(struct fuse_req *req, struct file *file,
643
644
			      struct inode *inode, loff_t pos, size_t count,
			      fl_owner_t owner)
645
646
{
	struct fuse_conn *fc = get_fuse_conn(inode);
647
648
649
650
	struct fuse_write_in *inarg = &req->misc.write.in;

	fuse_write_fill(req, file->private_data, inode, pos, count);
	inarg->flags = file->f_flags;
651
652
653
654
	if (owner != NULL) {
		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
	struct fuse_req *req;

998
999
1000
	req = fuse_get_req(fc);
	if (IS_ERR(req))
		return PTR_ERR(req);
Miklos Szeredi's avatar
Miklos Szeredi committed
1001
1002
1003

	while (count) {
		size_t nres;
1004
1005
		size_t nbytes = min(count, nmax);
		int err = fuse_get_user_pages(req, buf, &nbytes, write);
Miklos Szeredi's avatar
Miklos Szeredi committed
1006
1007
1008
1009
		if (err) {
			res = err;
			break;
		}
1010

Miklos Szeredi's avatar
Miklos Szeredi committed
1011
		if (write)
1012
1013
			nres = fuse_send_write(req, file, inode, pos, nbytes,
					       current->files);
Miklos Szeredi's avatar
Miklos Szeredi committed
1014
		else
1015
1016
			nres = fuse_send_read(req, file, inode, pos, nbytes,
					      current->files);
Miklos Szeredi's avatar
Miklos Szeredi committed
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
		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;
1032
1033
1034
1035
1036
1037
		if (count) {
			fuse_put_request(fc, req);
			req = fuse_get_req(fc);
			if (IS_ERR(req))
				break;
		}
Miklos Szeredi's avatar
Miklos Szeredi committed
1038
1039
	}
	fuse_put_request(fc, req);
1040
	if (res > 0)
Miklos Szeredi's avatar
Miklos Szeredi committed
1041
1042
1043
1044
1045
1046
1047
1048
		*ppos = pos;

	return res;
}

static ssize_t fuse_direct_read(struct file *file, char __user *buf,
				     size_t count, loff_t *ppos)
{
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
	ssize_t res;
	struct inode *inode = file->f_path.dentry->d_inode;

	if (is_bad_inode(inode))
		return -EIO;

	res = fuse_direct_io(file, buf, count, ppos, 0);

	fuse_invalidate_attr(inode);

	return res;
Miklos Szeredi's avatar
Miklos Szeredi committed
1060
1061
1062
1063
1064
}

static ssize_t fuse_direct_write(struct file *file, const char __user *buf,
				 size_t count, loff_t *ppos)
{
1065
	struct inode *inode = file->f_path.dentry->d_inode;
Miklos Szeredi's avatar
Miklos Szeredi committed
1066
	ssize_t res;
1067
1068
1069
1070

	if (is_bad_inode(inode))
		return -EIO;

Miklos Szeredi's avatar
Miklos Szeredi committed
1071
	/* Don't allow parallel writes to the same file */
1072
	mutex_lock(&inode->i_mutex);
1073
	res = generic_write_checks(file, ppos, &count, 0);
1074
	if (!res) {
1075
		res = fuse_direct_io(file, buf, count, ppos, 1);
1076
1077
1078
		if (res > 0)
			fuse_write_update_size(inode, *ppos);
	}
1079
	mutex_unlock(&inode->i_mutex);
1080
1081
1082

	fuse_invalidate_attr(inode);

Miklos Szeredi's avatar
Miklos Szeredi committed
1083
1084
1085
	return res;
}

Miklos Szeredi's avatar
Miklos Szeredi committed
1086
static void fuse_writepage_free(struct fuse_conn *fc, struct fuse_req *req)
1087
{
Miklos Szeredi's avatar
Miklos Szeredi committed
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
	__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)
1107
1108
__releases(&fc->lock)
__acquires(&fc->lock)
Miklos Szeredi's avatar
Miklos Szeredi committed
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
{
	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;
1124
	}
Miklos Szeredi's avatar
Miklos Szeredi committed
1125
1126
1127

	req->in.args[1].size = inarg->size;
	fi->writectr++;
1128
	fuse_request_send_background_locked(fc, req);
Miklos Szeredi's avatar
Miklos Szeredi committed
1129
1130
1131
1132
1133
1134
	return;

 out_free:
	fuse_writepage_finish(fc, req);
	spin_unlock(&fc->lock);
	fuse_writepage_free(fc, req);
1135
	fuse_put_request(fc, req);
Miklos Szeredi's avatar
Miklos Szeredi committed
1136
	spin_lock(&fc->lock);
1137
1138
}

Miklos Szeredi's avatar
Miklos Szeredi committed
1139
1140
1141
1142
1143
1144
1145
/*
 * 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)
1146
1147
__releases(&fc->lock)
__acquires(&fc->lock)
1148
{
Miklos Szeredi's avatar
Miklos Szeredi committed
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
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
	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);

1199
	fuse_write_fill(req, ff, inode, page_offset(page), 0);
Miklos Szeredi's avatar
Miklos Szeredi committed
1200
1201

	copy_highpage(tmp_page, page);
1202
	req->misc.write.in.write_flags |= FUSE_WRITE_CACHE;
1203
	req->in.argpages = 1;
Miklos Szeredi's avatar
Miklos Szeredi committed
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
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
	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
 */
1275
static int fuse_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
Miklos Szeredi's avatar
Miklos Szeredi committed
1276
{
1277
	struct page *page = vmf->page;
Miklos Szeredi's avatar
Miklos Szeredi committed
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
	/*
	 * 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;
1312
1313
1314
	return 0;
}

1315
1316
1317
1318
1319
1320
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;

1321
1322
	invalidate_inode_pages2(file->f_mapping);

1323
1324
1325
	return generic_file_mmap(file, vma);
}

1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
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,
1352
1353
			 const struct file_lock *fl, int opcode, pid_t pid,
			 int flock)
1354
{
1355
	struct inode *inode = file->f_path.dentry->d_inode;
1356
	struct fuse_conn *fc = get_fuse_conn(inode);
1357
1358
1359
1360
	struct fuse_file *ff = file->private_data;
	struct fuse_lk_in *arg = &req->misc.lk_in;

	arg->fh = ff->fh;
1361
	arg->owner = fuse_lock_owner_id(fc, fl->fl_owner);
1362
1363
1364
1365
	arg->lk.start = fl->fl_start;
	arg->lk.end = fl->fl_end;
	arg->lk.type = fl->fl_type;
	arg->lk.pid = pid;
1366
1367
	if (flock)
		arg->lk_flags |= FUSE_LK_FLOCK;
1368
1369
1370
1371
1372
1373
1374
1375
1376
	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)
{
Josef Sipek's avatar