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Merge tag 'regmap-fix-v5.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git...
[linux/fpc-iii.git] / fs / fuse / file.c
blob8cccecb55fb80b3d602de6487b0e313f5c930422
1 /*
2 FUSE: Filesystem in Userspace
3 Copyright (C) 2001-2008 Miklos Szeredi <miklos@szeredi.hu>
4
5 This program can be distributed under the terms of the GNU GPL.
6 See the file COPYING.
7 */
8
9 #include "fuse_i.h"
10
11 #include <linux/pagemap.h>
12 #include <linux/slab.h>
13 #include <linux/kernel.h>
14 #include <linux/sched.h>
15 #include <linux/sched/signal.h>
16 #include <linux/module.h>
17 #include <linux/compat.h>
18 #include <linux/swap.h>
19 #include <linux/falloc.h>
20 #include <linux/uio.h>
21 #include <linux/fs.h>
22
23 static struct page **fuse_pages_alloc(unsigned int npages, gfp_t flags,
24 struct fuse_page_desc **desc)
25 {
26 struct page **pages;
27
28 pages = kzalloc(npages * (sizeof(struct page *) +
29 sizeof(struct fuse_page_desc)), flags);
30 *desc = (void *) (pages + npages);
31
32 return pages;
33 }
34
35 static int fuse_send_open(struct fuse_mount *fm, u64 nodeid, struct file *file,
36 int opcode, struct fuse_open_out *outargp)
37 {
38 struct fuse_open_in inarg;
39 FUSE_ARGS(args);
40
41 memset(&inarg, 0, sizeof(inarg));
42 inarg.flags = file->f_flags & ~(O_CREAT | O_EXCL | O_NOCTTY);
43 if (!fm->fc->atomic_o_trunc)
44 inarg.flags &= ~O_TRUNC;
45
46 if (fm->fc->handle_killpriv_v2 &&
47 (inarg.flags & O_TRUNC) && !capable(CAP_FSETID)) {
48 inarg.open_flags |= FUSE_OPEN_KILL_SUIDGID;
49 }
50
51 args.opcode = opcode;
52 args.nodeid = nodeid;
53 args.in_numargs = 1;
54 args.in_args[0].size = sizeof(inarg);
55 args.in_args[0].value = &inarg;
56 args.out_numargs = 1;
57 args.out_args[0].size = sizeof(*outargp);
58 args.out_args[0].value = outargp;
59
60 return fuse_simple_request(fm, &args);
61 }
62
63 struct fuse_release_args {
64 struct fuse_args args;
65 struct fuse_release_in inarg;
66 struct inode *inode;
67 };
68
69 struct fuse_file *fuse_file_alloc(struct fuse_mount *fm)
70 {
71 struct fuse_file *ff;
72
73 ff = kzalloc(sizeof(struct fuse_file), GFP_KERNEL_ACCOUNT);
74 if (unlikely(!ff))
75 return NULL;
76
77 ff->fm = fm;
78 ff->release_args = kzalloc(sizeof(*ff->release_args),
79 GFP_KERNEL_ACCOUNT);
80 if (!ff->release_args) {
81 kfree(ff);
82 return NULL;
83 }
84
85 INIT_LIST_HEAD(&ff->write_entry);
86 mutex_init(&ff->readdir.lock);
87 refcount_set(&ff->count, 1);
88 RB_CLEAR_NODE(&ff->polled_node);
89 init_waitqueue_head(&ff->poll_wait);
90
91 ff->kh = atomic64_inc_return(&fm->fc->khctr);
92
93 return ff;
94 }
95
96 void fuse_file_free(struct fuse_file *ff)
97 {
98 kfree(ff->release_args);
99 mutex_destroy(&ff->readdir.lock);
100 kfree(ff);
101 }
102
103 static struct fuse_file *fuse_file_get(struct fuse_file *ff)
104 {
105 refcount_inc(&ff->count);
106 return ff;
107 }
108
109 static void fuse_release_end(struct fuse_mount *fm, struct fuse_args *args,
110 int error)
111 {
112 struct fuse_release_args *ra = container_of(args, typeof(*ra), args);
113
114 iput(ra->inode);
115 kfree(ra);
116 }
117
118 static void fuse_file_put(struct fuse_file *ff, bool sync, bool isdir)
119 {
120 if (refcount_dec_and_test(&ff->count)) {
121 struct fuse_args *args = &ff->release_args->args;
122
123 if (isdir ? ff->fm->fc->no_opendir : ff->fm->fc->no_open) {
124 /* Do nothing when client does not implement 'open' */
125 fuse_release_end(ff->fm, args, 0);
126 } else if (sync) {
127 fuse_simple_request(ff->fm, args);
128 fuse_release_end(ff->fm, args, 0);
129 } else {
130 args->end = fuse_release_end;
131 if (fuse_simple_background(ff->fm, args,
132 GFP_KERNEL | __GFP_NOFAIL))
133 fuse_release_end(ff->fm, args, -ENOTCONN);
134 }
135 kfree(ff);
136 }
137 }
138
139 int fuse_do_open(struct fuse_mount *fm, u64 nodeid, struct file *file,
140 bool isdir)
141 {
142 struct fuse_conn *fc = fm->fc;
143 struct fuse_file *ff;
144 int opcode = isdir ? FUSE_OPENDIR : FUSE_OPEN;
145
146 ff = fuse_file_alloc(fm);
147 if (!ff)
148 return -ENOMEM;
149
150 ff->fh = 0;
151 /* Default for no-open */
152 ff->open_flags = FOPEN_KEEP_CACHE | (isdir ? FOPEN_CACHE_DIR : 0);
153 if (isdir ? !fc->no_opendir : !fc->no_open) {
154 struct fuse_open_out outarg;
155 int err;
156
157 err = fuse_send_open(fm, nodeid, file, opcode, &outarg);
158 if (!err) {
159 ff->fh = outarg.fh;
160 ff->open_flags = outarg.open_flags;
161
162 } else if (err != -ENOSYS) {
163 fuse_file_free(ff);
164 return err;
165 } else {
166 if (isdir)
167 fc->no_opendir = 1;
168 else
169 fc->no_open = 1;
170 }
171 }
172
173 if (isdir)
174 ff->open_flags &= ~FOPEN_DIRECT_IO;
175
176 ff->nodeid = nodeid;
177 file->private_data = ff;
178
179 return 0;
180 }
181 EXPORT_SYMBOL_GPL(fuse_do_open);
182
183 static void fuse_link_write_file(struct file *file)
184 {
185 struct inode *inode = file_inode(file);
186 struct fuse_inode *fi = get_fuse_inode(inode);
187 struct fuse_file *ff = file->private_data;
188 /*
189 * file may be written through mmap, so chain it onto the
190 * inodes's write_file list
191 */
192 spin_lock(&fi->lock);
193 if (list_empty(&ff->write_entry))
194 list_add(&ff->write_entry, &fi->write_files);
195 spin_unlock(&fi->lock);
196 }
197
198 void fuse_finish_open(struct inode *inode, struct file *file)
199 {
200 struct fuse_file *ff = file->private_data;
201 struct fuse_conn *fc = get_fuse_conn(inode);
202
203 if (!(ff->open_flags & FOPEN_KEEP_CACHE))
204 invalidate_inode_pages2(inode->i_mapping);
205 if (ff->open_flags & FOPEN_STREAM)
206 stream_open(inode, file);
207 else if (ff->open_flags & FOPEN_NONSEEKABLE)
208 nonseekable_open(inode, file);
209 if (fc->atomic_o_trunc && (file->f_flags & O_TRUNC)) {
210 struct fuse_inode *fi = get_fuse_inode(inode);
211
212 spin_lock(&fi->lock);
213 fi->attr_version = atomic64_inc_return(&fc->attr_version);
214 i_size_write(inode, 0);
215 spin_unlock(&fi->lock);
216 fuse_invalidate_attr(inode);
217 if (fc->writeback_cache)
218 file_update_time(file);
219 }
220 if ((file->f_mode & FMODE_WRITE) && fc->writeback_cache)
221 fuse_link_write_file(file);
222 }
223
224 int fuse_open_common(struct inode *inode, struct file *file, bool isdir)
225 {
226 struct fuse_mount *fm = get_fuse_mount(inode);
227 struct fuse_conn *fc = fm->fc;
228 int err;
229 bool is_wb_truncate = (file->f_flags & O_TRUNC) &&
230 fc->atomic_o_trunc &&
231 fc->writeback_cache;
232 bool dax_truncate = (file->f_flags & O_TRUNC) &&
233 fc->atomic_o_trunc && FUSE_IS_DAX(inode);
234
235 if (fuse_is_bad(inode))
236 return -EIO;
237
238 err = generic_file_open(inode, file);
239 if (err)
240 return err;
241
242 if (is_wb_truncate || dax_truncate) {
243 inode_lock(inode);
244 fuse_set_nowrite(inode);
245 }
246
247 if (dax_truncate) {
248 down_write(&get_fuse_inode(inode)->i_mmap_sem);
249 err = fuse_dax_break_layouts(inode, 0, 0);
250 if (err)
251 goto out;
252 }
253
254 err = fuse_do_open(fm, get_node_id(inode), file, isdir);
255 if (!err)
256 fuse_finish_open(inode, file);
257
258 out:
259 if (dax_truncate)
260 up_write(&get_fuse_inode(inode)->i_mmap_sem);
261
262 if (is_wb_truncate | dax_truncate) {
263 fuse_release_nowrite(inode);
264 inode_unlock(inode);
265 }
266
267 return err;
268 }
269
270 static void fuse_prepare_release(struct fuse_inode *fi, struct fuse_file *ff,
271 int flags, int opcode)
272 {
273 struct fuse_conn *fc = ff->fm->fc;
274 struct fuse_release_args *ra = ff->release_args;
275
276 /* Inode is NULL on error path of fuse_create_open() */
277 if (likely(fi)) {
278 spin_lock(&fi->lock);
279 list_del(&ff->write_entry);
280 spin_unlock(&fi->lock);
281 }
282 spin_lock(&fc->lock);
283 if (!RB_EMPTY_NODE(&ff->polled_node))
284 rb_erase(&ff->polled_node, &fc->polled_files);
285 spin_unlock(&fc->lock);
286
287 wake_up_interruptible_all(&ff->poll_wait);
288
289 ra->inarg.fh = ff->fh;
290 ra->inarg.flags = flags;
291 ra->args.in_numargs = 1;
292 ra->args.in_args[0].size = sizeof(struct fuse_release_in);
293 ra->args.in_args[0].value = &ra->inarg;
294 ra->args.opcode = opcode;
295 ra->args.nodeid = ff->nodeid;
296 ra->args.force = true;
297 ra->args.nocreds = true;
298 }
299
300 void fuse_release_common(struct file *file, bool isdir)
301 {
302 struct fuse_inode *fi = get_fuse_inode(file_inode(file));
303 struct fuse_file *ff = file->private_data;
304 struct fuse_release_args *ra = ff->release_args;
305 int opcode = isdir ? FUSE_RELEASEDIR : FUSE_RELEASE;
306
307 fuse_prepare_release(fi, ff, file->f_flags, opcode);
308
309 if (ff->flock) {
310 ra->inarg.release_flags |= FUSE_RELEASE_FLOCK_UNLOCK;
311 ra->inarg.lock_owner = fuse_lock_owner_id(ff->fm->fc,
312 (fl_owner_t) file);
313 }
314 /* Hold inode until release is finished */
315 ra->inode = igrab(file_inode(file));
316
317 /*
318 * Normally this will send the RELEASE request, however if
319 * some asynchronous READ or WRITE requests are outstanding,
320 * the sending will be delayed.
321 *
322 * Make the release synchronous if this is a fuseblk mount,
323 * synchronous RELEASE is allowed (and desirable) in this case
324 * because the server can be trusted not to screw up.
325 */
326 fuse_file_put(ff, ff->fm->fc->destroy, isdir);
327 }
328
329 static int fuse_open(struct inode *inode, struct file *file)
330 {
331 return fuse_open_common(inode, file, false);
332 }
333
334 static int fuse_release(struct inode *inode, struct file *file)
335 {
336 struct fuse_conn *fc = get_fuse_conn(inode);
337
338 /* see fuse_vma_close() for !writeback_cache case */
339 if (fc->writeback_cache)
340 write_inode_now(inode, 1);
341
342 fuse_release_common(file, false);
343
344 /* return value is ignored by VFS */
345 return 0;
346 }
347
348 void fuse_sync_release(struct fuse_inode *fi, struct fuse_file *ff, int flags)
349 {
350 WARN_ON(refcount_read(&ff->count) > 1);
351 fuse_prepare_release(fi, ff, flags, FUSE_RELEASE);
352 /*
353 * iput(NULL) is a no-op and since the refcount is 1 and everything's
354 * synchronous, we are fine with not doing igrab() here"
355 */
356 fuse_file_put(ff, true, false);
357 }
358 EXPORT_SYMBOL_GPL(fuse_sync_release);
359
360 /*
361 * Scramble the ID space with XTEA, so that the value of the files_struct
362 * pointer is not exposed to userspace.
363 */
364 u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id)
365 {
366 u32 *k = fc->scramble_key;
367 u64 v = (unsigned long) id;
368 u32 v0 = v;
369 u32 v1 = v >> 32;
370 u32 sum = 0;
371 int i;
372
373 for (i = 0; i < 32; i++) {
374 v0 += ((v1 << 4 ^ v1 >> 5) + v1) ^ (sum + k[sum & 3]);
375 sum += 0x9E3779B9;
376 v1 += ((v0 << 4 ^ v0 >> 5) + v0) ^ (sum + k[sum>>11 & 3]);
377 }
378
379 return (u64) v0 + ((u64) v1 << 32);
380 }
381
382 struct fuse_writepage_args {
383 struct fuse_io_args ia;
384 struct rb_node writepages_entry;
385 struct list_head queue_entry;
386 struct fuse_writepage_args *next;
387 struct inode *inode;
388 };
389
390 static struct fuse_writepage_args *fuse_find_writeback(struct fuse_inode *fi,
391 pgoff_t idx_from, pgoff_t idx_to)
392 {
393 struct rb_node *n;
394
395 n = fi->writepages.rb_node;
396
397 while (n) {
398 struct fuse_writepage_args *wpa;
399 pgoff_t curr_index;
400
401 wpa = rb_entry(n, struct fuse_writepage_args, writepages_entry);
402 WARN_ON(get_fuse_inode(wpa->inode) != fi);
403 curr_index = wpa->ia.write.in.offset >> PAGE_SHIFT;
404 if (idx_from >= curr_index + wpa->ia.ap.num_pages)
405 n = n->rb_right;
406 else if (idx_to < curr_index)
407 n = n->rb_left;
408 else
409 return wpa;
410 }
411 return NULL;
412 }
413
414 /*
415 * Check if any page in a range is under writeback
416 *
417 * This is currently done by walking the list of writepage requests
418 * for the inode, which can be pretty inefficient.
419 */
420 static bool fuse_range_is_writeback(struct inode *inode, pgoff_t idx_from,
421 pgoff_t idx_to)
422 {
423 struct fuse_inode *fi = get_fuse_inode(inode);
424 bool found;
425
426 spin_lock(&fi->lock);
427 found = fuse_find_writeback(fi, idx_from, idx_to);
428 spin_unlock(&fi->lock);
429
430 return found;
431 }
432
433 static inline bool fuse_page_is_writeback(struct inode *inode, pgoff_t index)
434 {
435 return fuse_range_is_writeback(inode, index, index);
436 }
437
438 /*
439 * Wait for page writeback to be completed.
440 *
441 * Since fuse doesn't rely on the VM writeback tracking, this has to
442 * use some other means.
443 */
444 static void fuse_wait_on_page_writeback(struct inode *inode, pgoff_t index)
445 {
446 struct fuse_inode *fi = get_fuse_inode(inode);
447
448 wait_event(fi->page_waitq, !fuse_page_is_writeback(inode, index));
449 }
450
451 /*
452 * Wait for all pending writepages on the inode to finish.
453 *
454 * This is currently done by blocking further writes with FUSE_NOWRITE
455 * and waiting for all sent writes to complete.
456 *
457 * This must be called under i_mutex, otherwise the FUSE_NOWRITE usage
458 * could conflict with truncation.
459 */
460 static void fuse_sync_writes(struct inode *inode)
461 {
462 fuse_set_nowrite(inode);
463 fuse_release_nowrite(inode);
464 }
465
466 static int fuse_flush(struct file *file, fl_owner_t id)
467 {
468 struct inode *inode = file_inode(file);
469 struct fuse_mount *fm = get_fuse_mount(inode);
470 struct fuse_file *ff = file->private_data;
471 struct fuse_flush_in inarg;
472 FUSE_ARGS(args);
473 int err;
474
475 if (fuse_is_bad(inode))
476 return -EIO;
477
478 err = write_inode_now(inode, 1);
479 if (err)
480 return err;
481
482 inode_lock(inode);
483 fuse_sync_writes(inode);
484 inode_unlock(inode);
485
486 err = filemap_check_errors(file->f_mapping);
487 if (err)
488 return err;
489
490 err = 0;
491 if (fm->fc->no_flush)
492 goto inval_attr_out;
493
494 memset(&inarg, 0, sizeof(inarg));
495 inarg.fh = ff->fh;
496 inarg.lock_owner = fuse_lock_owner_id(fm->fc, id);
497 args.opcode = FUSE_FLUSH;
498 args.nodeid = get_node_id(inode);
499 args.in_numargs = 1;
500 args.in_args[0].size = sizeof(inarg);
501 args.in_args[0].value = &inarg;
502 args.force = true;
503
504 err = fuse_simple_request(fm, &args);
505 if (err == -ENOSYS) {
506 fm->fc->no_flush = 1;
507 err = 0;
508 }
509
510 inval_attr_out:
511 /*
512 * In memory i_blocks is not maintained by fuse, if writeback cache is
513 * enabled, i_blocks from cached attr may not be accurate.
514 */
515 if (!err && fm->fc->writeback_cache)
516 fuse_invalidate_attr(inode);
517 return err;
518 }
519
520 int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
521 int datasync, int opcode)
522 {
523 struct inode *inode = file->f_mapping->host;
524 struct fuse_mount *fm = get_fuse_mount(inode);
525 struct fuse_file *ff = file->private_data;
526 FUSE_ARGS(args);
527 struct fuse_fsync_in inarg;
528
529 memset(&inarg, 0, sizeof(inarg));
530 inarg.fh = ff->fh;
531 inarg.fsync_flags = datasync ? FUSE_FSYNC_FDATASYNC : 0;
532 args.opcode = opcode;
533 args.nodeid = get_node_id(inode);
534 args.in_numargs = 1;
535 args.in_args[0].size = sizeof(inarg);
536 args.in_args[0].value = &inarg;
537 return fuse_simple_request(fm, &args);
538 }
539
540 static int fuse_fsync(struct file *file, loff_t start, loff_t end,
541 int datasync)
542 {
543 struct inode *inode = file->f_mapping->host;
544 struct fuse_conn *fc = get_fuse_conn(inode);
545 int err;
546
547 if (fuse_is_bad(inode))
548 return -EIO;
549
550 inode_lock(inode);
551
552 /*
553 * Start writeback against all dirty pages of the inode, then
554 * wait for all outstanding writes, before sending the FSYNC
555 * request.
556 */
557 err = file_write_and_wait_range(file, start, end);
558 if (err)
559 goto out;
560
561 fuse_sync_writes(inode);
562
563 /*
564 * Due to implementation of fuse writeback
565 * file_write_and_wait_range() does not catch errors.
566 * We have to do this directly after fuse_sync_writes()
567 */
568 err = file_check_and_advance_wb_err(file);
569 if (err)
570 goto out;
571
572 err = sync_inode_metadata(inode, 1);
573 if (err)
574 goto out;
575
576 if (fc->no_fsync)
577 goto out;
578
579 err = fuse_fsync_common(file, start, end, datasync, FUSE_FSYNC);
580 if (err == -ENOSYS) {
581 fc->no_fsync = 1;
582 err = 0;
583 }
584 out:
585 inode_unlock(inode);
586
587 return err;
588 }
589
590 void fuse_read_args_fill(struct fuse_io_args *ia, struct file *file, loff_t pos,
591 size_t count, int opcode)
592 {
593 struct fuse_file *ff = file->private_data;
594 struct fuse_args *args = &ia->ap.args;
595
596 ia->read.in.fh = ff->fh;
597 ia->read.in.offset = pos;
598 ia->read.in.size = count;
599 ia->read.in.flags = file->f_flags;
600 args->opcode = opcode;
601 args->nodeid = ff->nodeid;
602 args->in_numargs = 1;
603 args->in_args[0].size = sizeof(ia->read.in);
604 args->in_args[0].value = &ia->read.in;
605 args->out_argvar = true;
606 args->out_numargs = 1;
607 args->out_args[0].size = count;
608 }
609
610 static void fuse_release_user_pages(struct fuse_args_pages *ap,
611 bool should_dirty)
612 {
613 unsigned int i;
614
615 for (i = 0; i < ap->num_pages; i++) {
616 if (should_dirty)
617 set_page_dirty_lock(ap->pages[i]);
618 put_page(ap->pages[i]);
619 }
620 }
621
622 static void fuse_io_release(struct kref *kref)
623 {
624 kfree(container_of(kref, struct fuse_io_priv, refcnt));
625 }
626
627 static ssize_t fuse_get_res_by_io(struct fuse_io_priv *io)
628 {
629 if (io->err)
630 return io->err;
631
632 if (io->bytes >= 0 && io->write)
633 return -EIO;
634
635 return io->bytes < 0 ? io->size : io->bytes;
636 }
637
638 /**
639 * In case of short read, the caller sets 'pos' to the position of
640 * actual end of fuse request in IO request. Otherwise, if bytes_requested
641 * == bytes_transferred or rw == WRITE, the caller sets 'pos' to -1.
642 *
643 * An example:
644 * User requested DIO read of 64K. It was splitted into two 32K fuse requests,
645 * both submitted asynchronously. The first of them was ACKed by userspace as
646 * fully completed (req->out.args[0].size == 32K) resulting in pos == -1. The
647 * second request was ACKed as short, e.g. only 1K was read, resulting in
648 * pos == 33K.
649 *
650 * Thus, when all fuse requests are completed, the minimal non-negative 'pos'
651 * will be equal to the length of the longest contiguous fragment of
652 * transferred data starting from the beginning of IO request.
653 */
654 static void fuse_aio_complete(struct fuse_io_priv *io, int err, ssize_t pos)
655 {
656 int left;
657
658 spin_lock(&io->lock);
659 if (err)
660 io->err = io->err ? : err;
661 else if (pos >= 0 && (io->bytes < 0 || pos < io->bytes))
662 io->bytes = pos;
663
664 left = --io->reqs;
665 if (!left && io->blocking)
666 complete(io->done);
667 spin_unlock(&io->lock);
668
669 if (!left && !io->blocking) {
670 ssize_t res = fuse_get_res_by_io(io);
671
672 if (res >= 0) {
673 struct inode *inode = file_inode(io->iocb->ki_filp);
674 struct fuse_conn *fc = get_fuse_conn(inode);
675 struct fuse_inode *fi = get_fuse_inode(inode);
676
677 spin_lock(&fi->lock);
678 fi->attr_version = atomic64_inc_return(&fc->attr_version);
679 spin_unlock(&fi->lock);
680 }
681
682 io->iocb->ki_complete(io->iocb, res, 0);
683 }
684
685 kref_put(&io->refcnt, fuse_io_release);
686 }
687
688 static struct fuse_io_args *fuse_io_alloc(struct fuse_io_priv *io,
689 unsigned int npages)
690 {
691 struct fuse_io_args *ia;
692
693 ia = kzalloc(sizeof(*ia), GFP_KERNEL);
694 if (ia) {
695 ia->io = io;
696 ia->ap.pages = fuse_pages_alloc(npages, GFP_KERNEL,
697 &ia->ap.descs);
698 if (!ia->ap.pages) {
699 kfree(ia);
700 ia = NULL;
701 }
702 }
703 return ia;
704 }
705
706 static void fuse_io_free(struct fuse_io_args *ia)
707 {
708 kfree(ia->ap.pages);
709 kfree(ia);
710 }
711
712 static void fuse_aio_complete_req(struct fuse_mount *fm, struct fuse_args *args,
713 int err)
714 {
715 struct fuse_io_args *ia = container_of(args, typeof(*ia), ap.args);
716 struct fuse_io_priv *io = ia->io;
717 ssize_t pos = -1;
718
719 fuse_release_user_pages(&ia->ap, io->should_dirty);
720
721 if (err) {
722 /* Nothing */
723 } else if (io->write) {
724 if (ia->write.out.size > ia->write.in.size) {
725 err = -EIO;
726 } else if (ia->write.in.size != ia->write.out.size) {
727 pos = ia->write.in.offset - io->offset +
728 ia->write.out.size;
729 }
730 } else {
731 u32 outsize = args->out_args[0].size;
732
733 if (ia->read.in.size != outsize)
734 pos = ia->read.in.offset - io->offset + outsize;
735 }
736
737 fuse_aio_complete(io, err, pos);
738 fuse_io_free(ia);
739 }
740
741 static ssize_t fuse_async_req_send(struct fuse_mount *fm,
742 struct fuse_io_args *ia, size_t num_bytes)
743 {
744 ssize_t err;
745 struct fuse_io_priv *io = ia->io;
746
747 spin_lock(&io->lock);
748 kref_get(&io->refcnt);
749 io->size += num_bytes;
750 io->reqs++;
751 spin_unlock(&io->lock);
752
753 ia->ap.args.end = fuse_aio_complete_req;
754 ia->ap.args.may_block = io->should_dirty;
755 err = fuse_simple_background(fm, &ia->ap.args, GFP_KERNEL);
756 if (err)
757 fuse_aio_complete_req(fm, &ia->ap.args, err);
758
759 return num_bytes;
760 }
761
762 static ssize_t fuse_send_read(struct fuse_io_args *ia, loff_t pos, size_t count,
763 fl_owner_t owner)
764 {
765 struct file *file = ia->io->iocb->ki_filp;
766 struct fuse_file *ff = file->private_data;
767 struct fuse_mount *fm = ff->fm;
768
769 fuse_read_args_fill(ia, file, pos, count, FUSE_READ);
770 if (owner != NULL) {
771 ia->read.in.read_flags |= FUSE_READ_LOCKOWNER;
772 ia->read.in.lock_owner = fuse_lock_owner_id(fm->fc, owner);
773 }
774
775 if (ia->io->async)
776 return fuse_async_req_send(fm, ia, count);
777
778 return fuse_simple_request(fm, &ia->ap.args);
779 }
780
781 static void fuse_read_update_size(struct inode *inode, loff_t size,
782 u64 attr_ver)
783 {
784 struct fuse_conn *fc = get_fuse_conn(inode);
785 struct fuse_inode *fi = get_fuse_inode(inode);
786
787 spin_lock(&fi->lock);
788 if (attr_ver == fi->attr_version && size < inode->i_size &&
789 !test_bit(FUSE_I_SIZE_UNSTABLE, &fi->state)) {
790 fi->attr_version = atomic64_inc_return(&fc->attr_version);
791 i_size_write(inode, size);
792 }
793 spin_unlock(&fi->lock);
794 }
795
796 static void fuse_short_read(struct inode *inode, u64 attr_ver, size_t num_read,
797 struct fuse_args_pages *ap)
798 {
799 struct fuse_conn *fc = get_fuse_conn(inode);
800
801 if (fc->writeback_cache) {
802 /*
803 * A hole in a file. Some data after the hole are in page cache,
804 * but have not reached the client fs yet. So, the hole is not
805 * present there.
806 */
807 int i;
808 int start_idx = num_read >> PAGE_SHIFT;
809 size_t off = num_read & (PAGE_SIZE - 1);
810
811 for (i = start_idx; i < ap->num_pages; i++) {
812 zero_user_segment(ap->pages[i], off, PAGE_SIZE);
813 off = 0;
814 }
815 } else {
816 loff_t pos = page_offset(ap->pages[0]) + num_read;
817 fuse_read_update_size(inode, pos, attr_ver);
818 }
819 }
820
821 static int fuse_do_readpage(struct file *file, struct page *page)
822 {
823 struct inode *inode = page->mapping->host;
824 struct fuse_mount *fm = get_fuse_mount(inode);
825 loff_t pos = page_offset(page);
826 struct fuse_page_desc desc = { .length = PAGE_SIZE };
827 struct fuse_io_args ia = {
828 .ap.args.page_zeroing = true,
829 .ap.args.out_pages = true,
830 .ap.num_pages = 1,
831 .ap.pages = &page,
832 .ap.descs = &desc,
833 };
834 ssize_t res;
835 u64 attr_ver;
836
837 /*
838 * Page writeback can extend beyond the lifetime of the
839 * page-cache page, so make sure we read a properly synced
840 * page.
841 */
842 fuse_wait_on_page_writeback(inode, page->index);
843
844 attr_ver = fuse_get_attr_version(fm->fc);
845
846 /* Don't overflow end offset */
847 if (pos + (desc.length - 1) == LLONG_MAX)
848 desc.length--;
849
850 fuse_read_args_fill(&ia, file, pos, desc.length, FUSE_READ);
851 res = fuse_simple_request(fm, &ia.ap.args);
852 if (res < 0)
853 return res;
854 /*
855 * Short read means EOF. If file size is larger, truncate it
856 */
857 if (res < desc.length)
858 fuse_short_read(inode, attr_ver, res, &ia.ap);
859
860 SetPageUptodate(page);
861
862 return 0;
863 }
864
865 static int fuse_readpage(struct file *file, struct page *page)
866 {
867 struct inode *inode = page->mapping->host;
868 int err;
869
870 err = -EIO;
871 if (fuse_is_bad(inode))
872 goto out;
873
874 err = fuse_do_readpage(file, page);
875 fuse_invalidate_atime(inode);
876 out:
877 unlock_page(page);
878 return err;
879 }
880
881 static void fuse_readpages_end(struct fuse_mount *fm, struct fuse_args *args,
882 int err)
883 {
884 int i;
885 struct fuse_io_args *ia = container_of(args, typeof(*ia), ap.args);
886 struct fuse_args_pages *ap = &ia->ap;
887 size_t count = ia->read.in.size;
888 size_t num_read = args->out_args[0].size;
889 struct address_space *mapping = NULL;
890
891 for (i = 0; mapping == NULL && i < ap->num_pages; i++)
892 mapping = ap->pages[i]->mapping;
893
894 if (mapping) {
895 struct inode *inode = mapping->host;
896
897 /*
898 * Short read means EOF. If file size is larger, truncate it
899 */
900 if (!err && num_read < count)
901 fuse_short_read(inode, ia->read.attr_ver, num_read, ap);
902
903 fuse_invalidate_atime(inode);
904 }
905
906 for (i = 0; i < ap->num_pages; i++) {
907 struct page *page = ap->pages[i];
908
909 if (!err)
910 SetPageUptodate(page);
911 else
912 SetPageError(page);
913 unlock_page(page);
914 put_page(page);
915 }
916 if (ia->ff)
917 fuse_file_put(ia->ff, false, false);
918
919 fuse_io_free(ia);
920 }
921
922 static void fuse_send_readpages(struct fuse_io_args *ia, struct file *file)
923 {
924 struct fuse_file *ff = file->private_data;
925 struct fuse_mount *fm = ff->fm;
926 struct fuse_args_pages *ap = &ia->ap;
927 loff_t pos = page_offset(ap->pages[0]);
928 size_t count = ap->num_pages << PAGE_SHIFT;
929 ssize_t res;
930 int err;
931
932 ap->args.out_pages = true;
933 ap->args.page_zeroing = true;
934 ap->args.page_replace = true;
935
936 /* Don't overflow end offset */
937 if (pos + (count - 1) == LLONG_MAX) {
938 count--;
939 ap->descs[ap->num_pages - 1].length--;
940 }
941 WARN_ON((loff_t) (pos + count) < 0);
942
943 fuse_read_args_fill(ia, file, pos, count, FUSE_READ);
944 ia->read.attr_ver = fuse_get_attr_version(fm->fc);
945 if (fm->fc->async_read) {
946 ia->ff = fuse_file_get(ff);
947 ap->args.end = fuse_readpages_end;
948 err = fuse_simple_background(fm, &ap->args, GFP_KERNEL);
949 if (!err)
950 return;
951 } else {
952 res = fuse_simple_request(fm, &ap->args);
953 err = res < 0 ? res : 0;
954 }
955 fuse_readpages_end(fm, &ap->args, err);
956 }
957
958 static void fuse_readahead(struct readahead_control *rac)
959 {
960 struct inode *inode = rac->mapping->host;
961 struct fuse_conn *fc = get_fuse_conn(inode);
962 unsigned int i, max_pages, nr_pages = 0;
963
964 if (fuse_is_bad(inode))
965 return;
966
967 max_pages = min_t(unsigned int, fc->max_pages,
968 fc->max_read / PAGE_SIZE);
969
970 for (;;) {
971 struct fuse_io_args *ia;
972 struct fuse_args_pages *ap;
973
974 nr_pages = readahead_count(rac) - nr_pages;
975 if (nr_pages > max_pages)
976 nr_pages = max_pages;
977 if (nr_pages == 0)
978 break;
979 ia = fuse_io_alloc(NULL, nr_pages);
980 if (!ia)
981 return;
982 ap = &ia->ap;
983 nr_pages = __readahead_batch(rac, ap->pages, nr_pages);
984 for (i = 0; i < nr_pages; i++) {
985 fuse_wait_on_page_writeback(inode,
986 readahead_index(rac) + i);
987 ap->descs[i].length = PAGE_SIZE;
988 }
989 ap->num_pages = nr_pages;
990 fuse_send_readpages(ia, rac->file);
991 }
992 }
993
994 static ssize_t fuse_cache_read_iter(struct kiocb *iocb, struct iov_iter *to)
995 {
996 struct inode *inode = iocb->ki_filp->f_mapping->host;
997 struct fuse_conn *fc = get_fuse_conn(inode);
998
999 /*
1000 * In auto invalidate mode, always update attributes on read.
1001 * Otherwise, only update if we attempt to read past EOF (to ensure
1002 * i_size is up to date).
1003 */
1004 if (fc->auto_inval_data ||
1005 (iocb->ki_pos + iov_iter_count(to) > i_size_read(inode))) {
1006 int err;
1007 err = fuse_update_attributes(inode, iocb->ki_filp);
1008 if (err)
1009 return err;
1010 }
1011
1012 return generic_file_read_iter(iocb, to);
1013 }
1014
1015 static void fuse_write_args_fill(struct fuse_io_args *ia, struct fuse_file *ff,
1016 loff_t pos, size_t count)
1017 {
1018 struct fuse_args *args = &ia->ap.args;
1019
1020 ia->write.in.fh = ff->fh;
1021 ia->write.in.offset = pos;
1022 ia->write.in.size = count;
1023 args->opcode = FUSE_WRITE;
1024 args->nodeid = ff->nodeid;
1025 args->in_numargs = 2;
1026 if (ff->fm->fc->minor < 9)
1027 args->in_args[0].size = FUSE_COMPAT_WRITE_IN_SIZE;
1028 else
1029 args->in_args[0].size = sizeof(ia->write.in);
1030 args->in_args[0].value = &ia->write.in;
1031 args->in_args[1].size = count;
1032 args->out_numargs = 1;
1033 args->out_args[0].size = sizeof(ia->write.out);
1034 args->out_args[0].value = &ia->write.out;
1035 }
1036
1037 static unsigned int fuse_write_flags(struct kiocb *iocb)
1038 {
1039 unsigned int flags = iocb->ki_filp->f_flags;
1040
1041 if (iocb->ki_flags & IOCB_DSYNC)
1042 flags |= O_DSYNC;
1043 if (iocb->ki_flags & IOCB_SYNC)
1044 flags |= O_SYNC;
1045
1046 return flags;
1047 }
1048
1049 static ssize_t fuse_send_write(struct fuse_io_args *ia, loff_t pos,
1050 size_t count, fl_owner_t owner)
1051 {
1052 struct kiocb *iocb = ia->io->iocb;
1053 struct file *file = iocb->ki_filp;
1054 struct fuse_file *ff = file->private_data;
1055 struct fuse_mount *fm = ff->fm;
1056 struct fuse_write_in *inarg = &ia->write.in;
1057 ssize_t err;
1058
1059 fuse_write_args_fill(ia, ff, pos, count);
1060 inarg->flags = fuse_write_flags(iocb);
1061 if (owner != NULL) {
1062 inarg->write_flags |= FUSE_WRITE_LOCKOWNER;
1063 inarg->lock_owner = fuse_lock_owner_id(fm->fc, owner);
1064 }
1065
1066 if (ia->io->async)
1067 return fuse_async_req_send(fm, ia, count);
1068
1069 err = fuse_simple_request(fm, &ia->ap.args);
1070 if (!err && ia->write.out.size > count)
1071 err = -EIO;
1072
1073 return err ?: ia->write.out.size;
1074 }
1075
1076 bool fuse_write_update_size(struct inode *inode, loff_t pos)
1077 {
1078 struct fuse_conn *fc = get_fuse_conn(inode);
1079 struct fuse_inode *fi = get_fuse_inode(inode);
1080 bool ret = false;
1081
1082 spin_lock(&fi->lock);
1083 fi->attr_version = atomic64_inc_return(&fc->attr_version);
1084 if (pos > inode->i_size) {
1085 i_size_write(inode, pos);
1086 ret = true;
1087 }
1088 spin_unlock(&fi->lock);
1089
1090 return ret;
1091 }
1092
1093 static ssize_t fuse_send_write_pages(struct fuse_io_args *ia,
1094 struct kiocb *iocb, struct inode *inode,
1095 loff_t pos, size_t count)
1096 {
1097 struct fuse_args_pages *ap = &ia->ap;
1098 struct file *file = iocb->ki_filp;
1099 struct fuse_file *ff = file->private_data;
1100 struct fuse_mount *fm = ff->fm;
1101 unsigned int offset, i;
1102 int err;
1103
1104 for (i = 0; i < ap->num_pages; i++)
1105 fuse_wait_on_page_writeback(inode, ap->pages[i]->index);
1106
1107 fuse_write_args_fill(ia, ff, pos, count);
1108 ia->write.in.flags = fuse_write_flags(iocb);
1109 if (fm->fc->handle_killpriv_v2 && !capable(CAP_FSETID))
1110 ia->write.in.write_flags |= FUSE_WRITE_KILL_SUIDGID;
1111
1112 err = fuse_simple_request(fm, &ap->args);
1113 if (!err && ia->write.out.size > count)
1114 err = -EIO;
1115
1116 offset = ap->descs[0].offset;
1117 count = ia->write.out.size;
1118 for (i = 0; i < ap->num_pages; i++) {
1119 struct page *page = ap->pages[i];
1120
1121 if (!err && !offset && count >= PAGE_SIZE)
1122 SetPageUptodate(page);
1123
1124 if (count > PAGE_SIZE - offset)
1125 count -= PAGE_SIZE - offset;
1126 else
1127 count = 0;
1128 offset = 0;
1129
1130 unlock_page(page);
1131 put_page(page);
1132 }
1133
1134 return err;
1135 }
1136
1137 static ssize_t fuse_fill_write_pages(struct fuse_args_pages *ap,
1138 struct address_space *mapping,
1139 struct iov_iter *ii, loff_t pos,
1140 unsigned int max_pages)
1141 {
1142 struct fuse_conn *fc = get_fuse_conn(mapping->host);
1143 unsigned offset = pos & (PAGE_SIZE - 1);
1144 size_t count = 0;
1145 int err;
1146
1147 ap->args.in_pages = true;
1148 ap->descs[0].offset = offset;
1149
1150 do {
1151 size_t tmp;
1152 struct page *page;
1153 pgoff_t index = pos >> PAGE_SHIFT;
1154 size_t bytes = min_t(size_t, PAGE_SIZE - offset,
1155 iov_iter_count(ii));
1156
1157 bytes = min_t(size_t, bytes, fc->max_write - count);
1158
1159 again:
1160 err = -EFAULT;
1161 if (iov_iter_fault_in_readable(ii, bytes))
1162 break;
1163
1164 err = -ENOMEM;
1165 page = grab_cache_page_write_begin(mapping, index, 0);
1166 if (!page)
1167 break;
1168
1169 if (mapping_writably_mapped(mapping))
1170 flush_dcache_page(page);
1171
1172 tmp = iov_iter_copy_from_user_atomic(page, ii, offset, bytes);
1173 flush_dcache_page(page);
1174
1175 iov_iter_advance(ii, tmp);
1176 if (!tmp) {
1177 unlock_page(page);
1178 put_page(page);
1179 bytes = min(bytes, iov_iter_single_seg_count(ii));
1180 goto again;
1181 }
1182
1183 err = 0;
1184 ap->pages[ap->num_pages] = page;
1185 ap->descs[ap->num_pages].length = tmp;
1186 ap->num_pages++;
1187
1188 count += tmp;
1189 pos += tmp;
1190 offset += tmp;
1191 if (offset == PAGE_SIZE)
1192 offset = 0;
1193
1194 if (!fc->big_writes)
1195 break;
1196 } while (iov_iter_count(ii) && count < fc->max_write &&
1197 ap->num_pages < max_pages && offset == 0);
1198
1199 return count > 0 ? count : err;
1200 }
1201
1202 static inline unsigned int fuse_wr_pages(loff_t pos, size_t len,
1203 unsigned int max_pages)
1204 {
1205 return min_t(unsigned int,
1206 ((pos + len - 1) >> PAGE_SHIFT) -
1207 (pos >> PAGE_SHIFT) + 1,
1208 max_pages);
1209 }
1210
1211 static ssize_t fuse_perform_write(struct kiocb *iocb,
1212 struct address_space *mapping,
1213 struct iov_iter *ii, loff_t pos)
1214 {
1215 struct inode *inode = mapping->host;
1216 struct fuse_conn *fc = get_fuse_conn(inode);
1217 struct fuse_inode *fi = get_fuse_inode(inode);
1218 int err = 0;
1219 ssize_t res = 0;
1220
1221 if (inode->i_size < pos + iov_iter_count(ii))
1222 set_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
1223
1224 do {
1225 ssize_t count;
1226 struct fuse_io_args ia = {};
1227 struct fuse_args_pages *ap = &ia.ap;
1228 unsigned int nr_pages = fuse_wr_pages(pos, iov_iter_count(ii),
1229 fc->max_pages);
1230
1231 ap->pages = fuse_pages_alloc(nr_pages, GFP_KERNEL, &ap->descs);
1232 if (!ap->pages) {
1233 err = -ENOMEM;
1234 break;
1235 }
1236
1237 count = fuse_fill_write_pages(ap, mapping, ii, pos, nr_pages);
1238 if (count <= 0) {
1239 err = count;
1240 } else {
1241 err = fuse_send_write_pages(&ia, iocb, inode,
1242 pos, count);
1243 if (!err) {
1244 size_t num_written = ia.write.out.size;
1245
1246 res += num_written;
1247 pos += num_written;
1248
1249 /* break out of the loop on short write */
1250 if (num_written != count)
1251 err = -EIO;
1252 }
1253 }
1254 kfree(ap->pages);
1255 } while (!err && iov_iter_count(ii));
1256
1257 if (res > 0)
1258 fuse_write_update_size(inode, pos);
1259
1260 clear_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
1261 fuse_invalidate_attr(inode);
1262
1263 return res > 0 ? res : err;
1264 }
1265
1266 static ssize_t fuse_cache_write_iter(struct kiocb *iocb, struct iov_iter *from)
1267 {
1268 struct file *file = iocb->ki_filp;
1269 struct address_space *mapping = file->f_mapping;
1270 ssize_t written = 0;
1271 ssize_t written_buffered = 0;
1272 struct inode *inode = mapping->host;
1273 ssize_t err;
1274 struct fuse_conn *fc = get_fuse_conn(inode);
1275 loff_t endbyte = 0;
1276
1277 if (fc->writeback_cache) {
1278 /* Update size (EOF optimization) and mode (SUID clearing) */
1279 err = fuse_update_attributes(mapping->host, file);
1280 if (err)
1281 return err;
1282
1283 if (fc->handle_killpriv_v2 &&
1284 should_remove_suid(file_dentry(file))) {
1285 goto writethrough;
1286 }
1287
1288 return generic_file_write_iter(iocb, from);
1289 }
1290
1291 writethrough:
1292 inode_lock(inode);
1293
1294 /* We can write back this queue in page reclaim */
1295 current->backing_dev_info = inode_to_bdi(inode);
1296
1297 err = generic_write_checks(iocb, from);
1298 if (err <= 0)
1299 goto out;
1300
1301 err = file_remove_privs(file);
1302 if (err)
1303 goto out;
1304
1305 err = file_update_time(file);
1306 if (err)
1307 goto out;
1308
1309 if (iocb->ki_flags & IOCB_DIRECT) {
1310 loff_t pos = iocb->ki_pos;
1311 written = generic_file_direct_write(iocb, from);
1312 if (written < 0 || !iov_iter_count(from))
1313 goto out;
1314
1315 pos += written;
1316
1317 written_buffered = fuse_perform_write(iocb, mapping, from, pos);
1318 if (written_buffered < 0) {
1319 err = written_buffered;
1320 goto out;
1321 }
1322 endbyte = pos + written_buffered - 1;
1323
1324 err = filemap_write_and_wait_range(file->f_mapping, pos,
1325 endbyte);
1326 if (err)
1327 goto out;
1328
1329 invalidate_mapping_pages(file->f_mapping,
1330 pos >> PAGE_SHIFT,
1331 endbyte >> PAGE_SHIFT);
1332
1333 written += written_buffered;
1334 iocb->ki_pos = pos + written_buffered;
1335 } else {
1336 written = fuse_perform_write(iocb, mapping, from, iocb->ki_pos);
1337 if (written >= 0)
1338 iocb->ki_pos += written;
1339 }
1340 out:
1341 current->backing_dev_info = NULL;
1342 inode_unlock(inode);
1343 if (written > 0)
1344 written = generic_write_sync(iocb, written);
1345
1346 return written ? written : err;
1347 }
1348
1349 static inline void fuse_page_descs_length_init(struct fuse_page_desc *descs,
1350 unsigned int index,
1351 unsigned int nr_pages)
1352 {
1353 int i;
1354
1355 for (i = index; i < index + nr_pages; i++)
1356 descs[i].length = PAGE_SIZE - descs[i].offset;
1357 }
1358
1359 static inline unsigned long fuse_get_user_addr(const struct iov_iter *ii)
1360 {
1361 return (unsigned long)ii->iov->iov_base + ii->iov_offset;
1362 }
1363
1364 static inline size_t fuse_get_frag_size(const struct iov_iter *ii,
1365 size_t max_size)
1366 {
1367 return min(iov_iter_single_seg_count(ii), max_size);
1368 }
1369
1370 static int fuse_get_user_pages(struct fuse_args_pages *ap, struct iov_iter *ii,
1371 size_t *nbytesp, int write,
1372 unsigned int max_pages)
1373 {
1374 size_t nbytes = 0; /* # bytes already packed in req */
1375 ssize_t ret = 0;
1376
1377 /* Special case for kernel I/O: can copy directly into the buffer */
1378 if (iov_iter_is_kvec(ii)) {
1379 unsigned long user_addr = fuse_get_user_addr(ii);
1380 size_t frag_size = fuse_get_frag_size(ii, *nbytesp);
1381
1382 if (write)
1383 ap->args.in_args[1].value = (void *) user_addr;
1384 else
1385 ap->args.out_args[0].value = (void *) user_addr;
1386
1387 iov_iter_advance(ii, frag_size);
1388 *nbytesp = frag_size;
1389 return 0;
1390 }
1391
1392 while (nbytes < *nbytesp && ap->num_pages < max_pages) {
1393 unsigned npages;
1394 size_t start;
1395 ret = iov_iter_get_pages(ii, &ap->pages[ap->num_pages],
1396 *nbytesp - nbytes,
1397 max_pages - ap->num_pages,
1398 &start);
1399 if (ret < 0)
1400 break;
1401
1402 iov_iter_advance(ii, ret);
1403 nbytes += ret;
1404
1405 ret += start;
1406 npages = (ret + PAGE_SIZE - 1) / PAGE_SIZE;
1407
1408 ap->descs[ap->num_pages].offset = start;
1409 fuse_page_descs_length_init(ap->descs, ap->num_pages, npages);
1410
1411 ap->num_pages += npages;
1412 ap->descs[ap->num_pages - 1].length -=
1413 (PAGE_SIZE - ret) & (PAGE_SIZE - 1);
1414 }
1415
1416 if (write)
1417 ap->args.in_pages = true;
1418 else
1419 ap->args.out_pages = true;
1420
1421 *nbytesp = nbytes;
1422
1423 return ret < 0 ? ret : 0;
1424 }
1425
1426 ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter,
1427 loff_t *ppos, int flags)
1428 {
1429 int write = flags & FUSE_DIO_WRITE;
1430 int cuse = flags & FUSE_DIO_CUSE;
1431 struct file *file = io->iocb->ki_filp;
1432 struct inode *inode = file->f_mapping->host;
1433 struct fuse_file *ff = file->private_data;
1434 struct fuse_conn *fc = ff->fm->fc;
1435 size_t nmax = write ? fc->max_write : fc->max_read;
1436 loff_t pos = *ppos;
1437 size_t count = iov_iter_count(iter);
1438 pgoff_t idx_from = pos >> PAGE_SHIFT;
1439 pgoff_t idx_to = (pos + count - 1) >> PAGE_SHIFT;
1440 ssize_t res = 0;
1441 int err = 0;
1442 struct fuse_io_args *ia;
1443 unsigned int max_pages;
1444
1445 max_pages = iov_iter_npages(iter, fc->max_pages);
1446 ia = fuse_io_alloc(io, max_pages);
1447 if (!ia)
1448 return -ENOMEM;
1449
1450 ia->io = io;
1451 if (!cuse && fuse_range_is_writeback(inode, idx_from, idx_to)) {
1452 if (!write)
1453 inode_lock(inode);
1454 fuse_sync_writes(inode);
1455 if (!write)
1456 inode_unlock(inode);
1457 }
1458
1459 io->should_dirty = !write && iter_is_iovec(iter);
1460 while (count) {
1461 ssize_t nres;
1462 fl_owner_t owner = current->files;
1463 size_t nbytes = min(count, nmax);
1464
1465 err = fuse_get_user_pages(&ia->ap, iter, &nbytes, write,
1466 max_pages);
1467 if (err && !nbytes)
1468 break;
1469
1470 if (write) {
1471 if (!capable(CAP_FSETID))
1472 ia->write.in.write_flags |= FUSE_WRITE_KILL_SUIDGID;
1473
1474 nres = fuse_send_write(ia, pos, nbytes, owner);
1475 } else {
1476 nres = fuse_send_read(ia, pos, nbytes, owner);
1477 }
1478
1479 if (!io->async || nres < 0) {
1480 fuse_release_user_pages(&ia->ap, io->should_dirty);
1481 fuse_io_free(ia);
1482 }
1483 ia = NULL;
1484 if (nres < 0) {
1485 iov_iter_revert(iter, nbytes);
1486 err = nres;
1487 break;
1488 }
1489 WARN_ON(nres > nbytes);
1490
1491 count -= nres;
1492 res += nres;
1493 pos += nres;
1494 if (nres != nbytes) {
1495 iov_iter_revert(iter, nbytes - nres);
1496 break;
1497 }
1498 if (count) {
1499 max_pages = iov_iter_npages(iter, fc->max_pages);
1500 ia = fuse_io_alloc(io, max_pages);
1501 if (!ia)
1502 break;
1503 }
1504 }
1505 if (ia)
1506 fuse_io_free(ia);
1507 if (res > 0)
1508 *ppos = pos;
1509
1510 return res > 0 ? res : err;
1511 }
1512 EXPORT_SYMBOL_GPL(fuse_direct_io);
1513
1514 static ssize_t __fuse_direct_read(struct fuse_io_priv *io,
1515 struct iov_iter *iter,
1516 loff_t *ppos)
1517 {
1518 ssize_t res;
1519 struct inode *inode = file_inode(io->iocb->ki_filp);
1520
1521 res = fuse_direct_io(io, iter, ppos, 0);
1522
1523 fuse_invalidate_atime(inode);
1524
1525 return res;
1526 }
1527
1528 static ssize_t fuse_direct_IO(struct kiocb *iocb, struct iov_iter *iter);
1529
1530 static ssize_t fuse_direct_read_iter(struct kiocb *iocb, struct iov_iter *to)
1531 {
1532 ssize_t res;
1533
1534 if (!is_sync_kiocb(iocb) && iocb->ki_flags & IOCB_DIRECT) {
1535 res = fuse_direct_IO(iocb, to);
1536 } else {
1537 struct fuse_io_priv io = FUSE_IO_PRIV_SYNC(iocb);
1538
1539 res = __fuse_direct_read(&io, to, &iocb->ki_pos);
1540 }
1541
1542 return res;
1543 }
1544
1545 static ssize_t fuse_direct_write_iter(struct kiocb *iocb, struct iov_iter *from)
1546 {
1547 struct inode *inode = file_inode(iocb->ki_filp);
1548 struct fuse_io_priv io = FUSE_IO_PRIV_SYNC(iocb);
1549 ssize_t res;
1550
1551 /* Don't allow parallel writes to the same file */
1552 inode_lock(inode);
1553 res = generic_write_checks(iocb, from);
1554 if (res > 0) {
1555 if (!is_sync_kiocb(iocb) && iocb->ki_flags & IOCB_DIRECT) {
1556 res = fuse_direct_IO(iocb, from);
1557 } else {
1558 res = fuse_direct_io(&io, from, &iocb->ki_pos,
1559 FUSE_DIO_WRITE);
1560 }
1561 }
1562 fuse_invalidate_attr(inode);
1563 if (res > 0)
1564 fuse_write_update_size(inode, iocb->ki_pos);
1565 inode_unlock(inode);
1566
1567 return res;
1568 }
1569
1570 static ssize_t fuse_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
1571 {
1572 struct file *file = iocb->ki_filp;
1573 struct fuse_file *ff = file->private_data;
1574 struct inode *inode = file_inode(file);
1575
1576 if (fuse_is_bad(inode))
1577 return -EIO;
1578
1579 if (FUSE_IS_DAX(inode))
1580 return fuse_dax_read_iter(iocb, to);
1581
1582 if (!(ff->open_flags & FOPEN_DIRECT_IO))
1583 return fuse_cache_read_iter(iocb, to);
1584 else
1585 return fuse_direct_read_iter(iocb, to);
1586 }
1587
1588 static ssize_t fuse_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
1589 {
1590 struct file *file = iocb->ki_filp;
1591 struct fuse_file *ff = file->private_data;
1592 struct inode *inode = file_inode(file);
1593
1594 if (fuse_is_bad(inode))
1595 return -EIO;
1596
1597 if (FUSE_IS_DAX(inode))
1598 return fuse_dax_write_iter(iocb, from);
1599
1600 if (!(ff->open_flags & FOPEN_DIRECT_IO))
1601 return fuse_cache_write_iter(iocb, from);
1602 else
1603 return fuse_direct_write_iter(iocb, from);
1604 }
1605
1606 static void fuse_writepage_free(struct fuse_writepage_args *wpa)
1607 {
1608 struct fuse_args_pages *ap = &wpa->ia.ap;
1609 int i;
1610
1611 for (i = 0; i < ap->num_pages; i++)
1612 __free_page(ap->pages[i]);
1613
1614 if (wpa->ia.ff)
1615 fuse_file_put(wpa->ia.ff, false, false);
1616
1617 kfree(ap->pages);
1618 kfree(wpa);
1619 }
1620
1621 static void fuse_writepage_finish(struct fuse_mount *fm,
1622 struct fuse_writepage_args *wpa)
1623 {
1624 struct fuse_args_pages *ap = &wpa->ia.ap;
1625 struct inode *inode = wpa->inode;
1626 struct fuse_inode *fi = get_fuse_inode(inode);
1627 struct backing_dev_info *bdi = inode_to_bdi(inode);
1628 int i;
1629
1630 for (i = 0; i < ap->num_pages; i++) {
1631 dec_wb_stat(&bdi->wb, WB_WRITEBACK);
1632 dec_node_page_state(ap->pages[i], NR_WRITEBACK_TEMP);
1633 wb_writeout_inc(&bdi->wb);
1634 }
1635 wake_up(&fi->page_waitq);
1636 }
1637
1638 /* Called under fi->lock, may release and reacquire it */
1639 static void fuse_send_writepage(struct fuse_mount *fm,
1640 struct fuse_writepage_args *wpa, loff_t size)
1641 __releases(fi->lock)
1642 __acquires(fi->lock)
1643 {
1644 struct fuse_writepage_args *aux, *next;
1645 struct fuse_inode *fi = get_fuse_inode(wpa->inode);
1646 struct fuse_write_in *inarg = &wpa->ia.write.in;
1647 struct fuse_args *args = &wpa->ia.ap.args;
1648 __u64 data_size = wpa->ia.ap.num_pages * PAGE_SIZE;
1649 int err;
1650
1651 fi->writectr++;
1652 if (inarg->offset + data_size <= size) {
1653 inarg->size = data_size;
1654 } else if (inarg->offset < size) {
1655 inarg->size = size - inarg->offset;
1656 } else {
1657 /* Got truncated off completely */
1658 goto out_free;
1659 }
1660
1661 args->in_args[1].size = inarg->size;
1662 args->force = true;
1663 args->nocreds = true;
1664
1665 err = fuse_simple_background(fm, args, GFP_ATOMIC);
1666 if (err == -ENOMEM) {
1667 spin_unlock(&fi->lock);
1668 err = fuse_simple_background(fm, args, GFP_NOFS | __GFP_NOFAIL);
1669 spin_lock(&fi->lock);
1670 }
1671
1672 /* Fails on broken connection only */
1673 if (unlikely(err))
1674 goto out_free;
1675
1676 return;
1677
1678 out_free:
1679 fi->writectr--;
1680 rb_erase(&wpa->writepages_entry, &fi->writepages);
1681 fuse_writepage_finish(fm, wpa);
1682 spin_unlock(&fi->lock);
1683
1684 /* After fuse_writepage_finish() aux request list is private */
1685 for (aux = wpa->next; aux; aux = next) {
1686 next = aux->next;
1687 aux->next = NULL;
1688 fuse_writepage_free(aux);
1689 }
1690
1691 fuse_writepage_free(wpa);
1692 spin_lock(&fi->lock);
1693 }
1694
1695 /*
1696 * If fi->writectr is positive (no truncate or fsync going on) send
1697 * all queued writepage requests.
1698 *
1699 * Called with fi->lock
1700 */
1701 void fuse_flush_writepages(struct inode *inode)
1702 __releases(fi->lock)
1703 __acquires(fi->lock)
1704 {
1705 struct fuse_mount *fm = get_fuse_mount(inode);
1706 struct fuse_inode *fi = get_fuse_inode(inode);
1707 loff_t crop = i_size_read(inode);
1708 struct fuse_writepage_args *wpa;
1709
1710 while (fi->writectr >= 0 && !list_empty(&fi->queued_writes)) {
1711 wpa = list_entry(fi->queued_writes.next,
1712 struct fuse_writepage_args, queue_entry);
1713 list_del_init(&wpa->queue_entry);
1714 fuse_send_writepage(fm, wpa, crop);
1715 }
1716 }
1717
1718 static struct fuse_writepage_args *fuse_insert_writeback(struct rb_root *root,
1719 struct fuse_writepage_args *wpa)
1720 {
1721 pgoff_t idx_from = wpa->ia.write.in.offset >> PAGE_SHIFT;
1722 pgoff_t idx_to = idx_from + wpa->ia.ap.num_pages - 1;
1723 struct rb_node **p = &root->rb_node;
1724 struct rb_node *parent = NULL;
1725
1726 WARN_ON(!wpa->ia.ap.num_pages);
1727 while (*p) {
1728 struct fuse_writepage_args *curr;
1729 pgoff_t curr_index;
1730
1731 parent = *p;
1732 curr = rb_entry(parent, struct fuse_writepage_args,
1733 writepages_entry);
1734 WARN_ON(curr->inode != wpa->inode);
1735 curr_index = curr->ia.write.in.offset >> PAGE_SHIFT;
1736
1737 if (idx_from >= curr_index + curr->ia.ap.num_pages)
1738 p = &(*p)->rb_right;
1739 else if (idx_to < curr_index)
1740 p = &(*p)->rb_left;
1741 else
1742 return curr;
1743 }
1744
1745 rb_link_node(&wpa->writepages_entry, parent, p);
1746 rb_insert_color(&wpa->writepages_entry, root);
1747 return NULL;
1748 }
1749
1750 static void tree_insert(struct rb_root *root, struct fuse_writepage_args *wpa)
1751 {
1752 WARN_ON(fuse_insert_writeback(root, wpa));
1753 }
1754
1755 static void fuse_writepage_end(struct fuse_mount *fm, struct fuse_args *args,
1756 int error)
1757 {
1758 struct fuse_writepage_args *wpa =
1759 container_of(args, typeof(*wpa), ia.ap.args);
1760 struct inode *inode = wpa->inode;
1761 struct fuse_inode *fi = get_fuse_inode(inode);
1762
1763 mapping_set_error(inode->i_mapping, error);
1764 spin_lock(&fi->lock);
1765 rb_erase(&wpa->writepages_entry, &fi->writepages);
1766 while (wpa->next) {
1767 struct fuse_mount *fm = get_fuse_mount(inode);
1768 struct fuse_write_in *inarg = &wpa->ia.write.in;
1769 struct fuse_writepage_args *next = wpa->next;
1770
1771 wpa->next = next->next;
1772 next->next = NULL;
1773 next->ia.ff = fuse_file_get(wpa->ia.ff);
1774 tree_insert(&fi->writepages, next);
1775
1776 /*
1777 * Skip fuse_flush_writepages() to make it easy to crop requests
1778 * based on primary request size.
1779 *
1780 * 1st case (trivial): there are no concurrent activities using
1781 * fuse_set/release_nowrite. Then we're on safe side because
1782 * fuse_flush_writepages() would call fuse_send_writepage()
1783 * anyway.
1784 *
1785 * 2nd case: someone called fuse_set_nowrite and it is waiting
1786 * now for completion of all in-flight requests. This happens
1787 * rarely and no more than once per page, so this should be
1788 * okay.
1789 *
1790 * 3rd case: someone (e.g. fuse_do_setattr()) is in the middle
1791 * of fuse_set_nowrite..fuse_release_nowrite section. The fact
1792 * that fuse_set_nowrite returned implies that all in-flight
1793 * requests were completed along with all of their secondary
1794 * requests. Further primary requests are blocked by negative
1795 * writectr. Hence there cannot be any in-flight requests and
1796 * no invocations of fuse_writepage_end() while we're in
1797 * fuse_set_nowrite..fuse_release_nowrite section.
1798 */
1799 fuse_send_writepage(fm, next, inarg->offset + inarg->size);
1800 }
1801 fi->writectr--;
1802 fuse_writepage_finish(fm, wpa);
1803 spin_unlock(&fi->lock);
1804 fuse_writepage_free(wpa);
1805 }
1806
1807 static struct fuse_file *__fuse_write_file_get(struct fuse_conn *fc,
1808 struct fuse_inode *fi)
1809 {
1810 struct fuse_file *ff = NULL;
1811
1812 spin_lock(&fi->lock);
1813 if (!list_empty(&fi->write_files)) {
1814 ff = list_entry(fi->write_files.next, struct fuse_file,
1815 write_entry);
1816 fuse_file_get(ff);
1817 }
1818 spin_unlock(&fi->lock);
1819
1820 return ff;
1821 }
1822
1823 static struct fuse_file *fuse_write_file_get(struct fuse_conn *fc,
1824 struct fuse_inode *fi)
1825 {
1826 struct fuse_file *ff = __fuse_write_file_get(fc, fi);
1827 WARN_ON(!ff);
1828 return ff;
1829 }
1830
1831 int fuse_write_inode(struct inode *inode, struct writeback_control *wbc)
1832 {
1833 struct fuse_conn *fc = get_fuse_conn(inode);
1834 struct fuse_inode *fi = get_fuse_inode(inode);
1835 struct fuse_file *ff;
1836 int err;
1837
1838 ff = __fuse_write_file_get(fc, fi);
1839 err = fuse_flush_times(inode, ff);
1840 if (ff)
1841 fuse_file_put(ff, false, false);
1842
1843 return err;
1844 }
1845
1846 static struct fuse_writepage_args *fuse_writepage_args_alloc(void)
1847 {
1848 struct fuse_writepage_args *wpa;
1849 struct fuse_args_pages *ap;
1850
1851 wpa = kzalloc(sizeof(*wpa), GFP_NOFS);
1852 if (wpa) {
1853 ap = &wpa->ia.ap;
1854 ap->num_pages = 0;
1855 ap->pages = fuse_pages_alloc(1, GFP_NOFS, &ap->descs);
1856 if (!ap->pages) {
1857 kfree(wpa);
1858 wpa = NULL;
1859 }
1860 }
1861 return wpa;
1862
1863 }
1864
1865 static int fuse_writepage_locked(struct page *page)
1866 {
1867 struct address_space *mapping = page->mapping;
1868 struct inode *inode = mapping->host;
1869 struct fuse_conn *fc = get_fuse_conn(inode);
1870 struct fuse_inode *fi = get_fuse_inode(inode);
1871 struct fuse_writepage_args *wpa;
1872 struct fuse_args_pages *ap;
1873 struct page *tmp_page;
1874 int error = -ENOMEM;
1875
1876 set_page_writeback(page);
1877
1878 wpa = fuse_writepage_args_alloc();
1879 if (!wpa)
1880 goto err;
1881 ap = &wpa->ia.ap;
1882
1883 tmp_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
1884 if (!tmp_page)
1885 goto err_free;
1886
1887 error = -EIO;
1888 wpa->ia.ff = fuse_write_file_get(fc, fi);
1889 if (!wpa->ia.ff)
1890 goto err_nofile;
1891
1892 fuse_write_args_fill(&wpa->ia, wpa->ia.ff, page_offset(page), 0);
1893
1894 copy_highpage(tmp_page, page);
1895 wpa->ia.write.in.write_flags |= FUSE_WRITE_CACHE;
1896 wpa->next = NULL;
1897 ap->args.in_pages = true;
1898 ap->num_pages = 1;
1899 ap->pages[0] = tmp_page;
1900 ap->descs[0].offset = 0;
1901 ap->descs[0].length = PAGE_SIZE;
1902 ap->args.end = fuse_writepage_end;
1903 wpa->inode = inode;
1904
1905 inc_wb_stat(&inode_to_bdi(inode)->wb, WB_WRITEBACK);
1906 inc_node_page_state(tmp_page, NR_WRITEBACK_TEMP);
1907
1908 spin_lock(&fi->lock);
1909 tree_insert(&fi->writepages, wpa);
1910 list_add_tail(&wpa->queue_entry, &fi->queued_writes);
1911 fuse_flush_writepages(inode);
1912 spin_unlock(&fi->lock);
1913
1914 end_page_writeback(page);
1915
1916 return 0;
1917
1918 err_nofile:
1919 __free_page(tmp_page);
1920 err_free:
1921 kfree(wpa);
1922 err:
1923 mapping_set_error(page->mapping, error);
1924 end_page_writeback(page);
1925 return error;
1926 }
1927
1928 static int fuse_writepage(struct page *page, struct writeback_control *wbc)
1929 {
1930 int err;
1931
1932 if (fuse_page_is_writeback(page->mapping->host, page->index)) {
1933 /*
1934 * ->writepages() should be called for sync() and friends. We
1935 * should only get here on direct reclaim and then we are
1936 * allowed to skip a page which is already in flight
1937 */
1938 WARN_ON(wbc->sync_mode == WB_SYNC_ALL);
1939
1940 redirty_page_for_writepage(wbc, page);
1941 unlock_page(page);
1942 return 0;
1943 }
1944
1945 err = fuse_writepage_locked(page);
1946 unlock_page(page);
1947
1948 return err;
1949 }
1950
1951 struct fuse_fill_wb_data {
1952 struct fuse_writepage_args *wpa;
1953 struct fuse_file *ff;
1954 struct inode *inode;
1955 struct page **orig_pages;
1956 unsigned int max_pages;
1957 };
1958
1959 static bool fuse_pages_realloc(struct fuse_fill_wb_data *data)
1960 {
1961 struct fuse_args_pages *ap = &data->wpa->ia.ap;
1962 struct fuse_conn *fc = get_fuse_conn(data->inode);
1963 struct page **pages;
1964 struct fuse_page_desc *descs;
1965 unsigned int npages = min_t(unsigned int,
1966 max_t(unsigned int, data->max_pages * 2,
1967 FUSE_DEFAULT_MAX_PAGES_PER_REQ),
1968 fc->max_pages);
1969 WARN_ON(npages <= data->max_pages);
1970
1971 pages = fuse_pages_alloc(npages, GFP_NOFS, &descs);
1972 if (!pages)
1973 return false;
1974
1975 memcpy(pages, ap->pages, sizeof(struct page *) * ap->num_pages);
1976 memcpy(descs, ap->descs, sizeof(struct fuse_page_desc) * ap->num_pages);
1977 kfree(ap->pages);
1978 ap->pages = pages;
1979 ap->descs = descs;
1980 data->max_pages = npages;
1981
1982 return true;
1983 }
1984
1985 static void fuse_writepages_send(struct fuse_fill_wb_data *data)
1986 {
1987 struct fuse_writepage_args *wpa = data->wpa;
1988 struct inode *inode = data->inode;
1989 struct fuse_inode *fi = get_fuse_inode(inode);
1990 int num_pages = wpa->ia.ap.num_pages;
1991 int i;
1992
1993 wpa->ia.ff = fuse_file_get(data->ff);
1994 spin_lock(&fi->lock);
1995 list_add_tail(&wpa->queue_entry, &fi->queued_writes);
1996 fuse_flush_writepages(inode);
1997 spin_unlock(&fi->lock);
1998
1999 for (i = 0; i < num_pages; i++)
2000 end_page_writeback(data->orig_pages[i]);
2001 }
2002
2003 /*
2004 * Check under fi->lock if the page is under writeback, and insert it onto the
2005 * rb_tree if not. Otherwise iterate auxiliary write requests, to see if there's
2006 * one already added for a page at this offset. If there's none, then insert
2007 * this new request onto the auxiliary list, otherwise reuse the existing one by
2008 * swapping the new temp page with the old one.
2009 */
2010 static bool fuse_writepage_add(struct fuse_writepage_args *new_wpa,
2011 struct page *page)
2012 {
2013 struct fuse_inode *fi = get_fuse_inode(new_wpa->inode);
2014 struct fuse_writepage_args *tmp;
2015 struct fuse_writepage_args *old_wpa;
2016 struct fuse_args_pages *new_ap = &new_wpa->ia.ap;
2017
2018 WARN_ON(new_ap->num_pages != 0);
2019 new_ap->num_pages = 1;
2020
2021 spin_lock(&fi->lock);
2022 old_wpa = fuse_insert_writeback(&fi->writepages, new_wpa);
2023 if (!old_wpa) {
2024 spin_unlock(&fi->lock);
2025 return true;
2026 }
2027
2028 for (tmp = old_wpa->next; tmp; tmp = tmp->next) {
2029 pgoff_t curr_index;
2030
2031 WARN_ON(tmp->inode != new_wpa->inode);
2032 curr_index = tmp->ia.write.in.offset >> PAGE_SHIFT;
2033 if (curr_index == page->index) {
2034 WARN_ON(tmp->ia.ap.num_pages != 1);
2035 swap(tmp->ia.ap.pages[0], new_ap->pages[0]);
2036 break;
2037 }
2038 }
2039
2040 if (!tmp) {
2041 new_wpa->next = old_wpa->next;
2042 old_wpa->next = new_wpa;
2043 }
2044
2045 spin_unlock(&fi->lock);
2046
2047 if (tmp) {
2048 struct backing_dev_info *bdi = inode_to_bdi(new_wpa->inode);
2049
2050 dec_wb_stat(&bdi->wb, WB_WRITEBACK);
2051 dec_node_page_state(new_ap->pages[0], NR_WRITEBACK_TEMP);
2052 wb_writeout_inc(&bdi->wb);
2053 fuse_writepage_free(new_wpa);
2054 }
2055
2056 return false;
2057 }
2058
2059 static bool fuse_writepage_need_send(struct fuse_conn *fc, struct page *page,
2060 struct fuse_args_pages *ap,
2061 struct fuse_fill_wb_data *data)
2062 {
2063 WARN_ON(!ap->num_pages);
2064
2065 /*
2066 * Being under writeback is unlikely but possible. For example direct
2067 * read to an mmaped fuse file will set the page dirty twice; once when
2068 * the pages are faulted with get_user_pages(), and then after the read
2069 * completed.
2070 */
2071 if (fuse_page_is_writeback(data->inode, page->index))
2072 return true;
2073
2074 /* Reached max pages */
2075 if (ap->num_pages == fc->max_pages)
2076 return true;
2077
2078 /* Reached max write bytes */
2079 if ((ap->num_pages + 1) * PAGE_SIZE > fc->max_write)
2080 return true;
2081
2082 /* Discontinuity */
2083 if (data->orig_pages[ap->num_pages - 1]->index + 1 != page->index)
2084 return true;
2085
2086 /* Need to grow the pages array? If so, did the expansion fail? */
2087 if (ap->num_pages == data->max_pages && !fuse_pages_realloc(data))
2088 return true;
2089
2090 return false;
2091 }
2092
2093 static int fuse_writepages_fill(struct page *page,
2094 struct writeback_control *wbc, void *_data)
2095 {
2096 struct fuse_fill_wb_data *data = _data;
2097 struct fuse_writepage_args *wpa = data->wpa;
2098 struct fuse_args_pages *ap = &wpa->ia.ap;
2099 struct inode *inode = data->inode;
2100 struct fuse_inode *fi = get_fuse_inode(inode);
2101 struct fuse_conn *fc = get_fuse_conn(inode);
2102 struct page *tmp_page;
2103 int err;
2104
2105 if (!data->ff) {
2106 err = -EIO;
2107 data->ff = fuse_write_file_get(fc, fi);
2108 if (!data->ff)
2109 goto out_unlock;
2110 }
2111
2112 if (wpa && fuse_writepage_need_send(fc, page, ap, data)) {
2113 fuse_writepages_send(data);
2114 data->wpa = NULL;
2115 }
2116
2117 err = -ENOMEM;
2118 tmp_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
2119 if (!tmp_page)
2120 goto out_unlock;
2121
2122 /*
2123 * The page must not be redirtied until the writeout is completed
2124 * (i.e. userspace has sent a reply to the write request). Otherwise
2125 * there could be more than one temporary page instance for each real
2126 * page.
2127 *
2128 * This is ensured by holding the page lock in page_mkwrite() while
2129 * checking fuse_page_is_writeback(). We already hold the page lock
2130 * since clear_page_dirty_for_io() and keep it held until we add the
2131 * request to the fi->writepages list and increment ap->num_pages.
2132 * After this fuse_page_is_writeback() will indicate that the page is
2133 * under writeback, so we can release the page lock.
2134 */
2135 if (data->wpa == NULL) {
2136 err = -ENOMEM;
2137 wpa = fuse_writepage_args_alloc();
2138 if (!wpa) {
2139 __free_page(tmp_page);
2140 goto out_unlock;
2141 }
2142 data->max_pages = 1;
2143
2144 ap = &wpa->ia.ap;
2145 fuse_write_args_fill(&wpa->ia, data->ff, page_offset(page), 0);
2146 wpa->ia.write.in.write_flags |= FUSE_WRITE_CACHE;
2147 wpa->next = NULL;
2148 ap->args.in_pages = true;
2149 ap->args.end = fuse_writepage_end;
2150 ap->num_pages = 0;
2151 wpa->inode = inode;
2152 }
2153 set_page_writeback(page);
2154
2155 copy_highpage(tmp_page, page);
2156 ap->pages[ap->num_pages] = tmp_page;
2157 ap->descs[ap->num_pages].offset = 0;
2158 ap->descs[ap->num_pages].length = PAGE_SIZE;
2159 data->orig_pages[ap->num_pages] = page;
2160
2161 inc_wb_stat(&inode_to_bdi(inode)->wb, WB_WRITEBACK);
2162 inc_node_page_state(tmp_page, NR_WRITEBACK_TEMP);
2163
2164 err = 0;
2165 if (data->wpa) {
2166 /*
2167 * Protected by fi->lock against concurrent access by
2168 * fuse_page_is_writeback().
2169 */
2170 spin_lock(&fi->lock);
2171 ap->num_pages++;
2172 spin_unlock(&fi->lock);
2173 } else if (fuse_writepage_add(wpa, page)) {
2174 data->wpa = wpa;
2175 } else {
2176 end_page_writeback(page);
2177 }
2178 out_unlock:
2179 unlock_page(page);
2180
2181 return err;
2182 }
2183
2184 static int fuse_writepages(struct address_space *mapping,
2185 struct writeback_control *wbc)
2186 {
2187 struct inode *inode = mapping->host;
2188 struct fuse_conn *fc = get_fuse_conn(inode);
2189 struct fuse_fill_wb_data data;
2190 int err;
2191
2192 err = -EIO;
2193 if (fuse_is_bad(inode))
2194 goto out;
2195
2196 data.inode = inode;
2197 data.wpa = NULL;
2198 data.ff = NULL;
2199
2200 err = -ENOMEM;
2201 data.orig_pages = kcalloc(fc->max_pages,
2202 sizeof(struct page *),
2203 GFP_NOFS);
2204 if (!data.orig_pages)
2205 goto out;
2206
2207 err = write_cache_pages(mapping, wbc, fuse_writepages_fill, &data);
2208 if (data.wpa) {
2209 WARN_ON(!data.wpa->ia.ap.num_pages);
2210 fuse_writepages_send(&data);
2211 }
2212 if (data.ff)
2213 fuse_file_put(data.ff, false, false);
2214
2215 kfree(data.orig_pages);
2216 out:
2217 return err;
2218 }
2219
2220 /*
2221 * It's worthy to make sure that space is reserved on disk for the write,
2222 * but how to implement it without killing performance need more thinking.
2223 */
2224 static int fuse_write_begin(struct file *file, struct address_space *mapping,
2225 loff_t pos, unsigned len, unsigned flags,
2226 struct page **pagep, void **fsdata)
2227 {
2228 pgoff_t index = pos >> PAGE_SHIFT;
2229 struct fuse_conn *fc = get_fuse_conn(file_inode(file));
2230 struct page *page;
2231 loff_t fsize;
2232 int err = -ENOMEM;
2233
2234 WARN_ON(!fc->writeback_cache);
2235
2236 page = grab_cache_page_write_begin(mapping, index, flags);
2237 if (!page)
2238 goto error;
2239
2240 fuse_wait_on_page_writeback(mapping->host, page->index);
2241
2242 if (PageUptodate(page) || len == PAGE_SIZE)
2243 goto success;
2244 /*
2245 * Check if the start this page comes after the end of file, in which
2246 * case the readpage can be optimized away.
2247 */
2248 fsize = i_size_read(mapping->host);
2249 if (fsize <= (pos & PAGE_MASK)) {
2250 size_t off = pos & ~PAGE_MASK;
2251 if (off)
2252 zero_user_segment(page, 0, off);
2253 goto success;
2254 }
2255 err = fuse_do_readpage(file, page);
2256 if (err)
2257 goto cleanup;
2258 success:
2259 *pagep = page;
2260 return 0;
2261
2262 cleanup:
2263 unlock_page(page);
2264 put_page(page);
2265 error:
2266 return err;
2267 }
2268
2269 static int fuse_write_end(struct file *file, struct address_space *mapping,
2270 loff_t pos, unsigned len, unsigned copied,
2271 struct page *page, void *fsdata)
2272 {
2273 struct inode *inode = page->mapping->host;
2274
2275 /* Haven't copied anything? Skip zeroing, size extending, dirtying. */
2276 if (!copied)
2277 goto unlock;
2278
2279 if (!PageUptodate(page)) {
2280 /* Zero any unwritten bytes at the end of the page */
2281 size_t endoff = (pos + copied) & ~PAGE_MASK;
2282 if (endoff)
2283 zero_user_segment(page, endoff, PAGE_SIZE);
2284 SetPageUptodate(page);
2285 }
2286
2287 fuse_write_update_size(inode, pos + copied);
2288 set_page_dirty(page);
2289
2290 unlock:
2291 unlock_page(page);
2292 put_page(page);
2293
2294 return copied;
2295 }
2296
2297 static int fuse_launder_page(struct page *page)
2298 {
2299 int err = 0;
2300 if (clear_page_dirty_for_io(page)) {
2301 struct inode *inode = page->mapping->host;
2302
2303 /* Serialize with pending writeback for the same page */
2304 fuse_wait_on_page_writeback(inode, page->index);
2305 err = fuse_writepage_locked(page);
2306 if (!err)
2307 fuse_wait_on_page_writeback(inode, page->index);
2308 }
2309 return err;
2310 }
2311
2312 /*
2313 * Write back dirty pages now, because there may not be any suitable
2314 * open files later
2315 */
2316 static void fuse_vma_close(struct vm_area_struct *vma)
2317 {
2318 filemap_write_and_wait(vma->vm_file->f_mapping);
2319 }
2320
2321 /*
2322 * Wait for writeback against this page to complete before allowing it
2323 * to be marked dirty again, and hence written back again, possibly
2324 * before the previous writepage completed.
2325 *
2326 * Block here, instead of in ->writepage(), so that the userspace fs
2327 * can only block processes actually operating on the filesystem.
2328 *
2329 * Otherwise unprivileged userspace fs would be able to block
2330 * unrelated:
2331 *
2332 * - page migration
2333 * - sync(2)
2334 * - try_to_free_pages() with order > PAGE_ALLOC_COSTLY_ORDER
2335 */
2336 static vm_fault_t fuse_page_mkwrite(struct vm_fault *vmf)
2337 {
2338 struct page *page = vmf->page;
2339 struct inode *inode = file_inode(vmf->vma->vm_file);
2340
2341 file_update_time(vmf->vma->vm_file);
2342 lock_page(page);
2343 if (page->mapping != inode->i_mapping) {
2344 unlock_page(page);
2345 return VM_FAULT_NOPAGE;
2346 }
2347
2348 fuse_wait_on_page_writeback(inode, page->index);
2349 return VM_FAULT_LOCKED;
2350 }
2351
2352 static const struct vm_operations_struct fuse_file_vm_ops = {
2353 .close = fuse_vma_close,
2354 .fault = filemap_fault,
2355 .map_pages = filemap_map_pages,
2356 .page_mkwrite = fuse_page_mkwrite,
2357 };
2358
2359 static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma)
2360 {
2361 struct fuse_file *ff = file->private_data;
2362
2363 /* DAX mmap is superior to direct_io mmap */
2364 if (FUSE_IS_DAX(file_inode(file)))
2365 return fuse_dax_mmap(file, vma);
2366
2367 if (ff->open_flags & FOPEN_DIRECT_IO) {
2368 /* Can't provide the coherency needed for MAP_SHARED */
2369 if (vma->vm_flags & VM_MAYSHARE)
2370 return -ENODEV;
2371
2372 invalidate_inode_pages2(file->f_mapping);
2373
2374 return generic_file_mmap(file, vma);
2375 }
2376
2377 if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_MAYWRITE))
2378 fuse_link_write_file(file);
2379
2380 file_accessed(file);
2381 vma->vm_ops = &fuse_file_vm_ops;
2382 return 0;
2383 }
2384
2385 static int convert_fuse_file_lock(struct fuse_conn *fc,
2386 const struct fuse_file_lock *ffl,
2387 struct file_lock *fl)
2388 {
2389 switch (ffl->type) {
2390 case F_UNLCK:
2391 break;
2392
2393 case F_RDLCK:
2394 case F_WRLCK:
2395 if (ffl->start > OFFSET_MAX || ffl->end > OFFSET_MAX ||
2396 ffl->end < ffl->start)
2397 return -EIO;
2398
2399 fl->fl_start = ffl->start;
2400 fl->fl_end = ffl->end;
2401
2402 /*
2403 * Convert pid into init's pid namespace. The locks API will
2404 * translate it into the caller's pid namespace.
2405 */
2406 rcu_read_lock();
2407 fl->fl_pid = pid_nr_ns(find_pid_ns(ffl->pid, fc->pid_ns), &init_pid_ns);
2408 rcu_read_unlock();
2409 break;
2410
2411 default:
2412 return -EIO;
2413 }
2414 fl->fl_type = ffl->type;
2415 return 0;
2416 }
2417
2418 static void fuse_lk_fill(struct fuse_args *args, struct file *file,
2419 const struct file_lock *fl, int opcode, pid_t pid,
2420 int flock, struct fuse_lk_in *inarg)
2421 {
2422 struct inode *inode = file_inode(file);
2423 struct fuse_conn *fc = get_fuse_conn(inode);
2424 struct fuse_file *ff = file->private_data;
2425
2426 memset(inarg, 0, sizeof(*inarg));
2427 inarg->fh = ff->fh;
2428 inarg->owner = fuse_lock_owner_id(fc, fl->fl_owner);
2429 inarg->lk.start = fl->fl_start;
2430 inarg->lk.end = fl->fl_end;
2431 inarg->lk.type = fl->fl_type;
2432 inarg->lk.pid = pid;
2433 if (flock)
2434 inarg->lk_flags |= FUSE_LK_FLOCK;
2435 args->opcode = opcode;
2436 args->nodeid = get_node_id(inode);
2437 args->in_numargs = 1;
2438 args->in_args[0].size = sizeof(*inarg);
2439 args->in_args[0].value = inarg;
2440 }
2441
2442 static int fuse_getlk(struct file *file, struct file_lock *fl)
2443 {
2444 struct inode *inode = file_inode(file);
2445 struct fuse_mount *fm = get_fuse_mount(inode);
2446 FUSE_ARGS(args);
2447 struct fuse_lk_in inarg;
2448 struct fuse_lk_out outarg;
2449 int err;
2450
2451 fuse_lk_fill(&args, file, fl, FUSE_GETLK, 0, 0, &inarg);
2452 args.out_numargs = 1;
2453 args.out_args[0].size = sizeof(outarg);
2454 args.out_args[0].value = &outarg;
2455 err = fuse_simple_request(fm, &args);
2456 if (!err)
2457 err = convert_fuse_file_lock(fm->fc, &outarg.lk, fl);
2458
2459 return err;
2460 }
2461
2462 static int fuse_setlk(struct file *file, struct file_lock *fl, int flock)
2463 {
2464 struct inode *inode = file_inode(file);
2465 struct fuse_mount *fm = get_fuse_mount(inode);
2466 FUSE_ARGS(args);
2467 struct fuse_lk_in inarg;
2468 int opcode = (fl->fl_flags & FL_SLEEP) ? FUSE_SETLKW : FUSE_SETLK;
2469 struct pid *pid = fl->fl_type != F_UNLCK ? task_tgid(current) : NULL;
2470 pid_t pid_nr = pid_nr_ns(pid, fm->fc->pid_ns);
2471 int err;
2472
2473 if (fl->fl_lmops && fl->fl_lmops->lm_grant) {
2474 /* NLM needs asynchronous locks, which we don't support yet */
2475 return -ENOLCK;
2476 }
2477
2478 /* Unlock on close is handled by the flush method */
2479 if ((fl->fl_flags & FL_CLOSE_POSIX) == FL_CLOSE_POSIX)
2480 return 0;
2481
2482 fuse_lk_fill(&args, file, fl, opcode, pid_nr, flock, &inarg);
2483 err = fuse_simple_request(fm, &args);
2484
2485 /* locking is restartable */
2486 if (err == -EINTR)
2487 err = -ERESTARTSYS;
2488
2489 return err;
2490 }
2491
2492 static int fuse_file_lock(struct file *file, int cmd, struct file_lock *fl)
2493 {
2494 struct inode *inode = file_inode(file);
2495 struct fuse_conn *fc = get_fuse_conn(inode);
2496 int err;
2497
2498 if (cmd == F_CANCELLK) {
2499 err = 0;
2500 } else if (cmd == F_GETLK) {
2501 if (fc->no_lock) {
2502 posix_test_lock(file, fl);
2503 err = 0;
2504 } else
2505 err = fuse_getlk(file, fl);
2506 } else {
2507 if (fc->no_lock)
2508 err = posix_lock_file(file, fl, NULL);
2509 else
2510 err = fuse_setlk(file, fl, 0);
2511 }
2512 return err;
2513 }
2514
2515 static int fuse_file_flock(struct file *file, int cmd, struct file_lock *fl)
2516 {
2517 struct inode *inode = file_inode(file);
2518 struct fuse_conn *fc = get_fuse_conn(inode);
2519 int err;
2520
2521 if (fc->no_flock) {
2522 err = locks_lock_file_wait(file, fl);
2523 } else {
2524 struct fuse_file *ff = file->private_data;
2525
2526 /* emulate flock with POSIX locks */
2527 ff->flock = true;
2528 err = fuse_setlk(file, fl, 1);
2529 }
2530
2531 return err;
2532 }
2533
2534 static sector_t fuse_bmap(struct address_space *mapping, sector_t block)
2535 {
2536 struct inode *inode = mapping->host;
2537 struct fuse_mount *fm = get_fuse_mount(inode);
2538 FUSE_ARGS(args);
2539 struct fuse_bmap_in inarg;
2540 struct fuse_bmap_out outarg;
2541 int err;
2542
2543 if (!inode->i_sb->s_bdev || fm->fc->no_bmap)
2544 return 0;
2545
2546 memset(&inarg, 0, sizeof(inarg));
2547 inarg.block = block;
2548 inarg.blocksize = inode->i_sb->s_blocksize;
2549 args.opcode = FUSE_BMAP;
2550 args.nodeid = get_node_id(inode);
2551 args.in_numargs = 1;
2552 args.in_args[0].size = sizeof(inarg);
2553 args.in_args[0].value = &inarg;
2554 args.out_numargs = 1;
2555 args.out_args[0].size = sizeof(outarg);
2556 args.out_args[0].value = &outarg;
2557 err = fuse_simple_request(fm, &args);
2558 if (err == -ENOSYS)
2559 fm->fc->no_bmap = 1;
2560
2561 return err ? 0 : outarg.block;
2562 }
2563
2564 static loff_t fuse_lseek(struct file *file, loff_t offset, int whence)
2565 {
2566 struct inode *inode = file->f_mapping->host;
2567 struct fuse_mount *fm = get_fuse_mount(inode);
2568 struct fuse_file *ff = file->private_data;
2569 FUSE_ARGS(args);
2570 struct fuse_lseek_in inarg = {
2571 .fh = ff->fh,
2572 .offset = offset,
2573 .whence = whence
2574 };
2575 struct fuse_lseek_out outarg;
2576 int err;
2577
2578 if (fm->fc->no_lseek)
2579 goto fallback;
2580
2581 args.opcode = FUSE_LSEEK;
2582 args.nodeid = ff->nodeid;
2583 args.in_numargs = 1;
2584 args.in_args[0].size = sizeof(inarg);
2585 args.in_args[0].value = &inarg;
2586 args.out_numargs = 1;
2587 args.out_args[0].size = sizeof(outarg);
2588 args.out_args[0].value = &outarg;
2589 err = fuse_simple_request(fm, &args);
2590 if (err) {
2591 if (err == -ENOSYS) {
2592 fm->fc->no_lseek = 1;
2593 goto fallback;
2594 }
2595 return err;
2596 }
2597
2598 return vfs_setpos(file, outarg.offset, inode->i_sb->s_maxbytes);
2599
2600 fallback:
2601 err = fuse_update_attributes(inode, file);
2602 if (!err)
2603 return generic_file_llseek(file, offset, whence);
2604 else
2605 return err;
2606 }
2607
2608 static loff_t fuse_file_llseek(struct file *file, loff_t offset, int whence)
2609 {
2610 loff_t retval;
2611 struct inode *inode = file_inode(file);
2612
2613 switch (whence) {
2614 case SEEK_SET:
2615 case SEEK_CUR:
2616 /* No i_mutex protection necessary for SEEK_CUR and SEEK_SET */
2617 retval = generic_file_llseek(file, offset, whence);
2618 break;
2619 case SEEK_END:
2620 inode_lock(inode);
2621 retval = fuse_update_attributes(inode, file);
2622 if (!retval)
2623 retval = generic_file_llseek(file, offset, whence);
2624 inode_unlock(inode);
2625 break;
2626 case SEEK_HOLE:
2627 case SEEK_DATA:
2628 inode_lock(inode);
2629 retval = fuse_lseek(file, offset, whence);
2630 inode_unlock(inode);
2631 break;
2632 default:
2633 retval = -EINVAL;
2634 }
2635
2636 return retval;
2637 }
2638
2639 /*
2640 * CUSE servers compiled on 32bit broke on 64bit kernels because the
2641 * ABI was defined to be 'struct iovec' which is different on 32bit
2642 * and 64bit. Fortunately we can determine which structure the server
2643 * used from the size of the reply.
2644 */
2645 static int fuse_copy_ioctl_iovec_old(struct iovec *dst, void *src,
2646 size_t transferred, unsigned count,
2647 bool is_compat)
2648 {
2649 #ifdef CONFIG_COMPAT
2650 if (count * sizeof(struct compat_iovec) == transferred) {
2651 struct compat_iovec *ciov = src;
2652 unsigned i;
2653
2654 /*
2655 * With this interface a 32bit server cannot support
2656 * non-compat (i.e. ones coming from 64bit apps) ioctl
2657 * requests
2658 */
2659 if (!is_compat)
2660 return -EINVAL;
2661
2662 for (i = 0; i < count; i++) {
2663 dst[i].iov_base = compat_ptr(ciov[i].iov_base);
2664 dst[i].iov_len = ciov[i].iov_len;
2665 }
2666 return 0;
2667 }
2668 #endif
2669
2670 if (count * sizeof(struct iovec) != transferred)
2671 return -EIO;
2672
2673 memcpy(dst, src, transferred);
2674 return 0;
2675 }
2676
2677 /* Make sure iov_length() won't overflow */
2678 static int fuse_verify_ioctl_iov(struct fuse_conn *fc, struct iovec *iov,
2679 size_t count)
2680 {
2681 size_t n;
2682 u32 max = fc->max_pages << PAGE_SHIFT;
2683
2684 for (n = 0; n < count; n++, iov++) {
2685 if (iov->iov_len > (size_t) max)
2686 return -ENOMEM;
2687 max -= iov->iov_len;
2688 }
2689 return 0;
2690 }
2691
2692 static int fuse_copy_ioctl_iovec(struct fuse_conn *fc, struct iovec *dst,
2693 void *src, size_t transferred, unsigned count,
2694 bool is_compat)
2695 {
2696 unsigned i;
2697 struct fuse_ioctl_iovec *fiov = src;
2698
2699 if (fc->minor < 16) {
2700 return fuse_copy_ioctl_iovec_old(dst, src, transferred,
2701 count, is_compat);
2702 }
2703
2704 if (count * sizeof(struct fuse_ioctl_iovec) != transferred)
2705 return -EIO;
2706
2707 for (i = 0; i < count; i++) {
2708 /* Did the server supply an inappropriate value? */
2709 if (fiov[i].base != (unsigned long) fiov[i].base ||
2710 fiov[i].len != (unsigned long) fiov[i].len)
2711 return -EIO;
2712
2713 dst[i].iov_base = (void __user *) (unsigned long) fiov[i].base;
2714 dst[i].iov_len = (size_t) fiov[i].len;
2715
2716 #ifdef CONFIG_COMPAT
2717 if (is_compat &&
2718 (ptr_to_compat(dst[i].iov_base) != fiov[i].base ||
2719 (compat_size_t) dst[i].iov_len != fiov[i].len))
2720 return -EIO;
2721 #endif
2722 }
2723
2724 return 0;
2725 }
2726
2727
2728 /*
2729 * For ioctls, there is no generic way to determine how much memory
2730 * needs to be read and/or written. Furthermore, ioctls are allowed
2731 * to dereference the passed pointer, so the parameter requires deep
2732 * copying but FUSE has no idea whatsoever about what to copy in or
2733 * out.
2734 *
2735 * This is solved by allowing FUSE server to retry ioctl with
2736 * necessary in/out iovecs. Let's assume the ioctl implementation
2737 * needs to read in the following structure.
2738 *
2739 * struct a {
2740 * char *buf;
2741 * size_t buflen;
2742 * }
2743 *
2744 * On the first callout to FUSE server, inarg->in_size and
2745 * inarg->out_size will be NULL; then, the server completes the ioctl
2746 * with FUSE_IOCTL_RETRY set in out->flags, out->in_iovs set to 1 and
2747 * the actual iov array to
2748 *
2749 * { { .iov_base = inarg.arg, .iov_len = sizeof(struct a) } }
2750 *
2751 * which tells FUSE to copy in the requested area and retry the ioctl.
2752 * On the second round, the server has access to the structure and
2753 * from that it can tell what to look for next, so on the invocation,
2754 * it sets FUSE_IOCTL_RETRY, out->in_iovs to 2 and iov array to
2755 *
2756 * { { .iov_base = inarg.arg, .iov_len = sizeof(struct a) },
2757 * { .iov_base = a.buf, .iov_len = a.buflen } }
2758 *
2759 * FUSE will copy both struct a and the pointed buffer from the
2760 * process doing the ioctl and retry ioctl with both struct a and the
2761 * buffer.
2762 *
2763 * This time, FUSE server has everything it needs and completes ioctl
2764 * without FUSE_IOCTL_RETRY which finishes the ioctl call.
2765 *
2766 * Copying data out works the same way.
2767 *
2768 * Note that if FUSE_IOCTL_UNRESTRICTED is clear, the kernel
2769 * automatically initializes in and out iovs by decoding @cmd with
2770 * _IOC_* macros and the server is not allowed to request RETRY. This
2771 * limits ioctl data transfers to well-formed ioctls and is the forced
2772 * behavior for all FUSE servers.
2773 */
2774 long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
2775 unsigned int flags)
2776 {
2777 struct fuse_file *ff = file->private_data;
2778 struct fuse_mount *fm = ff->fm;
2779 struct fuse_ioctl_in inarg = {
2780 .fh = ff->fh,
2781 .cmd = cmd,
2782 .arg = arg,
2783 .flags = flags
2784 };
2785 struct fuse_ioctl_out outarg;
2786 struct iovec *iov_page = NULL;
2787 struct iovec *in_iov = NULL, *out_iov = NULL;
2788 unsigned int in_iovs = 0, out_iovs = 0, max_pages;
2789 size_t in_size, out_size, c;
2790 ssize_t transferred;
2791 int err, i;
2792 struct iov_iter ii;
2793 struct fuse_args_pages ap = {};
2794
2795 #if BITS_PER_LONG == 32
2796 inarg.flags |= FUSE_IOCTL_32BIT;
2797 #else
2798 if (flags & FUSE_IOCTL_COMPAT) {
2799 inarg.flags |= FUSE_IOCTL_32BIT;
2800 #ifdef CONFIG_X86_X32
2801 if (in_x32_syscall())
2802 inarg.flags |= FUSE_IOCTL_COMPAT_X32;
2803 #endif
2804 }
2805 #endif
2806
2807 /* assume all the iovs returned by client always fits in a page */
2808 BUILD_BUG_ON(sizeof(struct fuse_ioctl_iovec) * FUSE_IOCTL_MAX_IOV > PAGE_SIZE);
2809
2810 err = -ENOMEM;
2811 ap.pages = fuse_pages_alloc(fm->fc->max_pages, GFP_KERNEL, &ap.descs);
2812 iov_page = (struct iovec *) __get_free_page(GFP_KERNEL);
2813 if (!ap.pages || !iov_page)
2814 goto out;
2815
2816 fuse_page_descs_length_init(ap.descs, 0, fm->fc->max_pages);
2817
2818 /*
2819 * If restricted, initialize IO parameters as encoded in @cmd.
2820 * RETRY from server is not allowed.
2821 */
2822 if (!(flags & FUSE_IOCTL_UNRESTRICTED)) {
2823 struct iovec *iov = iov_page;
2824
2825 iov->iov_base = (void __user *)arg;
2826
2827 switch (cmd) {
2828 case FS_IOC_GETFLAGS:
2829 case FS_IOC_SETFLAGS:
2830 iov->iov_len = sizeof(int);
2831 break;
2832 default:
2833 iov->iov_len = _IOC_SIZE(cmd);
2834 break;
2835 }
2836
2837 if (_IOC_DIR(cmd) & _IOC_WRITE) {
2838 in_iov = iov;
2839 in_iovs = 1;
2840 }
2841
2842 if (_IOC_DIR(cmd) & _IOC_READ) {
2843 out_iov = iov;
2844 out_iovs = 1;
2845 }
2846 }
2847
2848 retry:
2849 inarg.in_size = in_size = iov_length(in_iov, in_iovs);
2850 inarg.out_size = out_size = iov_length(out_iov, out_iovs);
2851
2852 /*
2853 * Out data can be used either for actual out data or iovs,
2854 * make sure there always is at least one page.
2855 */
2856 out_size = max_t(size_t, out_size, PAGE_SIZE);
2857 max_pages = DIV_ROUND_UP(max(in_size, out_size), PAGE_SIZE);
2858
2859 /* make sure there are enough buffer pages and init request with them */
2860 err = -ENOMEM;
2861 if (max_pages > fm->fc->max_pages)
2862 goto out;
2863 while (ap.num_pages < max_pages) {
2864 ap.pages[ap.num_pages] = alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
2865 if (!ap.pages[ap.num_pages])
2866 goto out;
2867 ap.num_pages++;
2868 }
2869
2870
2871 /* okay, let's send it to the client */
2872 ap.args.opcode = FUSE_IOCTL;
2873 ap.args.nodeid = ff->nodeid;
2874 ap.args.in_numargs = 1;
2875 ap.args.in_args[0].size = sizeof(inarg);
2876 ap.args.in_args[0].value = &inarg;
2877 if (in_size) {
2878 ap.args.in_numargs++;
2879 ap.args.in_args[1].size = in_size;
2880 ap.args.in_pages = true;
2881
2882 err = -EFAULT;
2883 iov_iter_init(&ii, WRITE, in_iov, in_iovs, in_size);
2884 for (i = 0; iov_iter_count(&ii) && !WARN_ON(i >= ap.num_pages); i++) {
2885 c = copy_page_from_iter(ap.pages[i], 0, PAGE_SIZE, &ii);
2886 if (c != PAGE_SIZE && iov_iter_count(&ii))
2887 goto out;
2888 }
2889 }
2890
2891 ap.args.out_numargs = 2;
2892 ap.args.out_args[0].size = sizeof(outarg);
2893 ap.args.out_args[0].value = &outarg;
2894 ap.args.out_args[1].size = out_size;
2895 ap.args.out_pages = true;
2896 ap.args.out_argvar = true;
2897
2898 transferred = fuse_simple_request(fm, &ap.args);
2899 err = transferred;
2900 if (transferred < 0)
2901 goto out;
2902
2903 /* did it ask for retry? */
2904 if (outarg.flags & FUSE_IOCTL_RETRY) {
2905 void *vaddr;
2906
2907 /* no retry if in restricted mode */
2908 err = -EIO;
2909 if (!(flags & FUSE_IOCTL_UNRESTRICTED))
2910 goto out;
2911
2912 in_iovs = outarg.in_iovs;
2913 out_iovs = outarg.out_iovs;
2914
2915 /*
2916 * Make sure things are in boundary, separate checks
2917 * are to protect against overflow.
2918 */
2919 err = -ENOMEM;
2920 if (in_iovs > FUSE_IOCTL_MAX_IOV ||
2921 out_iovs > FUSE_IOCTL_MAX_IOV ||
2922 in_iovs + out_iovs > FUSE_IOCTL_MAX_IOV)
2923 goto out;
2924
2925 vaddr = kmap_atomic(ap.pages[0]);
2926 err = fuse_copy_ioctl_iovec(fm->fc, iov_page, vaddr,
2927 transferred, in_iovs + out_iovs,
2928 (flags & FUSE_IOCTL_COMPAT) != 0);
2929 kunmap_atomic(vaddr);
2930 if (err)
2931 goto out;
2932
2933 in_iov = iov_page;
2934 out_iov = in_iov + in_iovs;
2935
2936 err = fuse_verify_ioctl_iov(fm->fc, in_iov, in_iovs);
2937 if (err)
2938 goto out;
2939
2940 err = fuse_verify_ioctl_iov(fm->fc, out_iov, out_iovs);
2941 if (err)
2942 goto out;
2943
2944 goto retry;
2945 }
2946
2947 err = -EIO;
2948 if (transferred > inarg.out_size)
2949 goto out;
2950
2951 err = -EFAULT;
2952 iov_iter_init(&ii, READ, out_iov, out_iovs, transferred);
2953 for (i = 0; iov_iter_count(&ii) && !WARN_ON(i >= ap.num_pages); i++) {
2954 c = copy_page_to_iter(ap.pages[i], 0, PAGE_SIZE, &ii);
2955 if (c != PAGE_SIZE && iov_iter_count(&ii))
2956 goto out;
2957 }
2958 err = 0;
2959 out:
2960 free_page((unsigned long) iov_page);
2961 while (ap.num_pages)
2962 __free_page(ap.pages[--ap.num_pages]);
2963 kfree(ap.pages);
2964
2965 return err ? err : outarg.result;
2966 }
2967 EXPORT_SYMBOL_GPL(fuse_do_ioctl);
2968
2969 long fuse_ioctl_common(struct file *file, unsigned int cmd,
2970 unsigned long arg, unsigned int flags)
2971 {
2972 struct inode *inode = file_inode(file);
2973 struct fuse_conn *fc = get_fuse_conn(inode);
2974
2975 if (!fuse_allow_current_process(fc))
2976 return -EACCES;
2977
2978 if (fuse_is_bad(inode))
2979 return -EIO;
2980
2981 return fuse_do_ioctl(file, cmd, arg, flags);
2982 }
2983
2984 static long fuse_file_ioctl(struct file *file, unsigned int cmd,
2985 unsigned long arg)
2986 {
2987 return fuse_ioctl_common(file, cmd, arg, 0);
2988 }
2989
2990 static long fuse_file_compat_ioctl(struct file *file, unsigned int cmd,
2991 unsigned long arg)
2992 {
2993 return fuse_ioctl_common(file, cmd, arg, FUSE_IOCTL_COMPAT);
2994 }
2995
2996 /*
2997 * All files which have been polled are linked to RB tree
2998 * fuse_conn->polled_files which is indexed by kh. Walk the tree and
2999 * find the matching one.
3000 */
3001 static struct rb_node **fuse_find_polled_node(struct fuse_conn *fc, u64 kh,
3002 struct rb_node **parent_out)
3003 {
3004 struct rb_node **link = &fc->polled_files.rb_node;
3005 struct rb_node *last = NULL;
3006
3007 while (*link) {
3008 struct fuse_file *ff;
3009
3010 last = *link;
3011 ff = rb_entry(last, struct fuse_file, polled_node);
3012
3013 if (kh < ff->kh)
3014 link = &last->rb_left;
3015 else if (kh > ff->kh)
3016 link = &last->rb_right;
3017 else
3018 return link;
3019 }
3020
3021 if (parent_out)
3022 *parent_out = last;
3023 return link;
3024 }
3025
3026 /*
3027 * The file is about to be polled. Make sure it's on the polled_files
3028 * RB tree. Note that files once added to the polled_files tree are
3029 * not removed before the file is released. This is because a file
3030 * polled once is likely to be polled again.
3031 */
3032 static void fuse_register_polled_file(struct fuse_conn *fc,
3033 struct fuse_file *ff)
3034 {
3035 spin_lock(&fc->lock);
3036 if (RB_EMPTY_NODE(&ff->polled_node)) {
3037 struct rb_node **link, *parent;
3038
3039 link = fuse_find_polled_node(fc, ff->kh, &parent);
3040 BUG_ON(*link);
3041 rb_link_node(&ff->polled_node, parent, link);
3042 rb_insert_color(&ff->polled_node, &fc->polled_files);
3043 }
3044 spin_unlock(&fc->lock);
3045 }
3046
3047 __poll_t fuse_file_poll(struct file *file, poll_table *wait)
3048 {
3049 struct fuse_file *ff = file->private_data;
3050 struct fuse_mount *fm = ff->fm;
3051 struct fuse_poll_in inarg = { .fh = ff->fh, .kh = ff->kh };
3052 struct fuse_poll_out outarg;
3053 FUSE_ARGS(args);
3054 int err;
3055
3056 if (fm->fc->no_poll)
3057 return DEFAULT_POLLMASK;
3058
3059 poll_wait(file, &ff->poll_wait, wait);
3060 inarg.events = mangle_poll(poll_requested_events(wait));
3061
3062 /*
3063 * Ask for notification iff there's someone waiting for it.
3064 * The client may ignore the flag and always notify.
3065 */
3066 if (waitqueue_active(&ff->poll_wait)) {
3067 inarg.flags |= FUSE_POLL_SCHEDULE_NOTIFY;
3068 fuse_register_polled_file(fm->fc, ff);
3069 }
3070
3071 args.opcode = FUSE_POLL;
3072 args.nodeid = ff->nodeid;
3073 args.in_numargs = 1;
3074 args.in_args[0].size = sizeof(inarg);
3075 args.in_args[0].value = &inarg;
3076 args.out_numargs = 1;
3077 args.out_args[0].size = sizeof(outarg);
3078 args.out_args[0].value = &outarg;
3079 err = fuse_simple_request(fm, &args);
3080
3081 if (!err)
3082 return demangle_poll(outarg.revents);
3083 if (err == -ENOSYS) {
3084 fm->fc->no_poll = 1;
3085 return DEFAULT_POLLMASK;
3086 }
3087 return EPOLLERR;
3088 }
3089 EXPORT_SYMBOL_GPL(fuse_file_poll);
3090
3091 /*
3092 * This is called from fuse_handle_notify() on FUSE_NOTIFY_POLL and
3093 * wakes up the poll waiters.
3094 */
3095 int fuse_notify_poll_wakeup(struct fuse_conn *fc,
3096 struct fuse_notify_poll_wakeup_out *outarg)
3097 {
3098 u64 kh = outarg->kh;
3099 struct rb_node **link;
3100
3101 spin_lock(&fc->lock);
3102
3103 link = fuse_find_polled_node(fc, kh, NULL);
3104 if (*link) {
3105 struct fuse_file *ff;
3106
3107 ff = rb_entry(*link, struct fuse_file, polled_node);
3108 wake_up_interruptible_sync(&ff->poll_wait);
3109 }
3110
3111 spin_unlock(&fc->lock);
3112 return 0;
3113 }
3114
3115 static void fuse_do_truncate(struct file *file)
3116 {
3117 struct inode *inode = file->f_mapping->host;
3118 struct iattr attr;
3119
3120 attr.ia_valid = ATTR_SIZE;
3121 attr.ia_size = i_size_read(inode);
3122
3123 attr.ia_file = file;
3124 attr.ia_valid |= ATTR_FILE;
3125
3126 fuse_do_setattr(file_dentry(file), &attr, file);
3127 }
3128
3129 static inline loff_t fuse_round_up(struct fuse_conn *fc, loff_t off)
3130 {
3131 return round_up(off, fc->max_pages << PAGE_SHIFT);
3132 }
3133
3134 static ssize_t
3135 fuse_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
3136 {
3137 DECLARE_COMPLETION_ONSTACK(wait);
3138 ssize_t ret = 0;
3139 struct file *file = iocb->ki_filp;
3140 struct fuse_file *ff = file->private_data;
3141 loff_t pos = 0;
3142 struct inode *inode;
3143 loff_t i_size;
3144 size_t count = iov_iter_count(iter), shortened = 0;
3145 loff_t offset = iocb->ki_pos;
3146 struct fuse_io_priv *io;
3147
3148 pos = offset;
3149 inode = file->f_mapping->host;
3150 i_size = i_size_read(inode);
3151
3152 if ((iov_iter_rw(iter) == READ) && (offset >= i_size))
3153 return 0;
3154
3155 io = kmalloc(sizeof(struct fuse_io_priv), GFP_KERNEL);
3156 if (!io)
3157 return -ENOMEM;
3158 spin_lock_init(&io->lock);
3159 kref_init(&io->refcnt);
3160 io->reqs = 1;
3161 io->bytes = -1;
3162 io->size = 0;
3163 io->offset = offset;
3164 io->write = (iov_iter_rw(iter) == WRITE);
3165 io->err = 0;
3166 /*
3167 * By default, we want to optimize all I/Os with async request
3168 * submission to the client filesystem if supported.
3169 */
3170 io->async = ff->fm->fc->async_dio;
3171 io->iocb = iocb;
3172 io->blocking = is_sync_kiocb(iocb);
3173
3174 /* optimization for short read */
3175 if (io->async && !io->write && offset + count > i_size) {
3176 iov_iter_truncate(iter, fuse_round_up(ff->fm->fc, i_size - offset));
3177 shortened = count - iov_iter_count(iter);
3178 count -= shortened;
3179 }
3180
3181 /*
3182 * We cannot asynchronously extend the size of a file.
3183 * In such case the aio will behave exactly like sync io.
3184 */
3185 if ((offset + count > i_size) && io->write)
3186 io->blocking = true;
3187
3188 if (io->async && io->blocking) {
3189 /*
3190 * Additional reference to keep io around after
3191 * calling fuse_aio_complete()
3192 */
3193 kref_get(&io->refcnt);
3194 io->done = &wait;
3195 }
3196
3197 if (iov_iter_rw(iter) == WRITE) {
3198 ret = fuse_direct_io(io, iter, &pos, FUSE_DIO_WRITE);
3199 fuse_invalidate_attr(inode);
3200 } else {
3201 ret = __fuse_direct_read(io, iter, &pos);
3202 }
3203 iov_iter_reexpand(iter, iov_iter_count(iter) + shortened);
3204
3205 if (io->async) {
3206 bool blocking = io->blocking;
3207
3208 fuse_aio_complete(io, ret < 0 ? ret : 0, -1);
3209
3210 /* we have a non-extending, async request, so return */
3211 if (!blocking)
3212 return -EIOCBQUEUED;
3213
3214 wait_for_completion(&wait);
3215 ret = fuse_get_res_by_io(io);
3216 }
3217
3218 kref_put(&io->refcnt, fuse_io_release);
3219
3220 if (iov_iter_rw(iter) == WRITE) {
3221 if (ret > 0)
3222 fuse_write_update_size(inode, pos);
3223 else if (ret < 0 && offset + count > i_size)
3224 fuse_do_truncate(file);
3225 }
3226
3227 return ret;
3228 }
3229
3230 static int fuse_writeback_range(struct inode *inode, loff_t start, loff_t end)
3231 {
3232 int err = filemap_write_and_wait_range(inode->i_mapping, start, end);
3233
3234 if (!err)
3235 fuse_sync_writes(inode);
3236
3237 return err;
3238 }
3239
3240 static long fuse_file_fallocate(struct file *file, int mode, loff_t offset,
3241 loff_t length)
3242 {
3243 struct fuse_file *ff = file->private_data;
3244 struct inode *inode = file_inode(file);
3245 struct fuse_inode *fi = get_fuse_inode(inode);
3246 struct fuse_mount *fm = ff->fm;
3247 FUSE_ARGS(args);
3248 struct fuse_fallocate_in inarg = {
3249 .fh = ff->fh,
3250 .offset = offset,
3251 .length = length,
3252 .mode = mode
3253 };
3254 int err;
3255 bool lock_inode = !(mode & FALLOC_FL_KEEP_SIZE) ||
3256 (mode & FALLOC_FL_PUNCH_HOLE);
3257
3258 bool block_faults = FUSE_IS_DAX(inode) && lock_inode;
3259
3260 if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
3261 return -EOPNOTSUPP;
3262
3263 if (fm->fc->no_fallocate)
3264 return -EOPNOTSUPP;
3265
3266 if (lock_inode) {
3267 inode_lock(inode);
3268 if (block_faults) {
3269 down_write(&fi->i_mmap_sem);
3270 err = fuse_dax_break_layouts(inode, 0, 0);
3271 if (err)
3272 goto out;
3273 }
3274
3275 if (mode & FALLOC_FL_PUNCH_HOLE) {
3276 loff_t endbyte = offset + length - 1;
3277
3278 err = fuse_writeback_range(inode, offset, endbyte);
3279 if (err)
3280 goto out;
3281 }
3282 }
3283
3284 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
3285 offset + length > i_size_read(inode)) {
3286 err = inode_newsize_ok(inode, offset + length);
3287 if (err)
3288 goto out;
3289 }
3290
3291 if (!(mode & FALLOC_FL_KEEP_SIZE))
3292 set_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
3293
3294 args.opcode = FUSE_FALLOCATE;
3295 args.nodeid = ff->nodeid;
3296 args.in_numargs = 1;
3297 args.in_args[0].size = sizeof(inarg);
3298 args.in_args[0].value = &inarg;
3299 err = fuse_simple_request(fm, &args);
3300 if (err == -ENOSYS) {
3301 fm->fc->no_fallocate = 1;
3302 err = -EOPNOTSUPP;
3303 }
3304 if (err)
3305 goto out;
3306
3307 /* we could have extended the file */
3308 if (!(mode & FALLOC_FL_KEEP_SIZE)) {
3309 bool changed = fuse_write_update_size(inode, offset + length);
3310
3311 if (changed && fm->fc->writeback_cache)
3312 file_update_time(file);
3313 }
3314
3315 if (mode & FALLOC_FL_PUNCH_HOLE)
3316 truncate_pagecache_range(inode, offset, offset + length - 1);
3317
3318 fuse_invalidate_attr(inode);
3319
3320 out:
3321 if (!(mode & FALLOC_FL_KEEP_SIZE))
3322 clear_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
3323
3324 if (block_faults)
3325 up_write(&fi->i_mmap_sem);
3326
3327 if (lock_inode)
3328 inode_unlock(inode);
3329
3330 return err;
3331 }
3332
3333 static ssize_t __fuse_copy_file_range(struct file *file_in, loff_t pos_in,
3334 struct file *file_out, loff_t pos_out,
3335 size_t len, unsigned int flags)
3336 {
3337 struct fuse_file *ff_in = file_in->private_data;
3338 struct fuse_file *ff_out = file_out->private_data;
3339 struct inode *inode_in = file_inode(file_in);
3340 struct inode *inode_out = file_inode(file_out);
3341 struct fuse_inode *fi_out = get_fuse_inode(inode_out);
3342 struct fuse_mount *fm = ff_in->fm;
3343 struct fuse_conn *fc = fm->fc;
3344 FUSE_ARGS(args);
3345 struct fuse_copy_file_range_in inarg = {
3346 .fh_in = ff_in->fh,
3347 .off_in = pos_in,
3348 .nodeid_out = ff_out->nodeid,
3349 .fh_out = ff_out->fh,
3350 .off_out = pos_out,
3351 .len = len,
3352 .flags = flags
3353 };
3354 struct fuse_write_out outarg;
3355 ssize_t err;
3356 /* mark unstable when write-back is not used, and file_out gets
3357 * extended */
3358 bool is_unstable = (!fc->writeback_cache) &&
3359 ((pos_out + len) > inode_out->i_size);
3360
3361 if (fc->no_copy_file_range)
3362 return -EOPNOTSUPP;
3363
3364 if (file_inode(file_in)->i_sb != file_inode(file_out)->i_sb)
3365 return -EXDEV;
3366
3367 inode_lock(inode_in);
3368 err = fuse_writeback_range(inode_in, pos_in, pos_in + len - 1);
3369 inode_unlock(inode_in);
3370 if (err)
3371 return err;
3372
3373 inode_lock(inode_out);
3374
3375 err = file_modified(file_out);
3376 if (err)
3377 goto out;
3378
3379 /*
3380 * Write out dirty pages in the destination file before sending the COPY
3381 * request to userspace. After the request is completed, truncate off
3382 * pages (including partial ones) from the cache that have been copied,
3383 * since these contain stale data at that point.
3384 *
3385 * This should be mostly correct, but if the COPY writes to partial
3386 * pages (at the start or end) and the parts not covered by the COPY are
3387 * written through a memory map after calling fuse_writeback_range(),
3388 * then these partial page modifications will be lost on truncation.
3389 *
3390 * It is unlikely that someone would rely on such mixed style
3391 * modifications. Yet this does give less guarantees than if the
3392 * copying was performed with write(2).
3393 *
3394 * To fix this a i_mmap_sem style lock could be used to prevent new
3395 * faults while the copy is ongoing.
3396 */
3397 err = fuse_writeback_range(inode_out, pos_out, pos_out + len - 1);
3398 if (err)
3399 goto out;
3400
3401 if (is_unstable)
3402 set_bit(FUSE_I_SIZE_UNSTABLE, &fi_out->state);
3403
3404 args.opcode = FUSE_COPY_FILE_RANGE;
3405 args.nodeid = ff_in->nodeid;
3406 args.in_numargs = 1;
3407 args.in_args[0].size = sizeof(inarg);
3408 args.in_args[0].value = &inarg;
3409 args.out_numargs = 1;
3410 args.out_args[0].size = sizeof(outarg);
3411 args.out_args[0].value = &outarg;
3412 err = fuse_simple_request(fm, &args);
3413 if (err == -ENOSYS) {
3414 fc->no_copy_file_range = 1;
3415 err = -EOPNOTSUPP;
3416 }
3417 if (err)
3418 goto out;
3419
3420 truncate_inode_pages_range(inode_out->i_mapping,
3421 ALIGN_DOWN(pos_out, PAGE_SIZE),
3422 ALIGN(pos_out + outarg.size, PAGE_SIZE) - 1);
3423
3424 if (fc->writeback_cache) {
3425 fuse_write_update_size(inode_out, pos_out + outarg.size);
3426 file_update_time(file_out);
3427 }
3428
3429 fuse_invalidate_attr(inode_out);
3430
3431 err = outarg.size;
3432 out:
3433 if (is_unstable)
3434 clear_bit(FUSE_I_SIZE_UNSTABLE, &fi_out->state);
3435
3436 inode_unlock(inode_out);
3437 file_accessed(file_in);
3438
3439 return err;
3440 }
3441
3442 static ssize_t fuse_copy_file_range(struct file *src_file, loff_t src_off,
3443 struct file *dst_file, loff_t dst_off,
3444 size_t len, unsigned int flags)
3445 {
3446 ssize_t ret;
3447
3448 ret = __fuse_copy_file_range(src_file, src_off, dst_file, dst_off,
3449 len, flags);
3450
3451 if (ret == -EOPNOTSUPP || ret == -EXDEV)
3452 ret = generic_copy_file_range(src_file, src_off, dst_file,
3453 dst_off, len, flags);
3454 return ret;
3455 }
3456
3457 static const struct file_operations fuse_file_operations = {
3458 .llseek = fuse_file_llseek,
3459 .read_iter = fuse_file_read_iter,
3460 .write_iter = fuse_file_write_iter,
3461 .mmap = fuse_file_mmap,
3462 .open = fuse_open,
3463 .flush = fuse_flush,
3464 .release = fuse_release,
3465 .fsync = fuse_fsync,
3466 .lock = fuse_file_lock,
3467 .get_unmapped_area = thp_get_unmapped_area,
3468 .flock = fuse_file_flock,
3469 .splice_read = generic_file_splice_read,
3470 .splice_write = iter_file_splice_write,
3471 .unlocked_ioctl = fuse_file_ioctl,
3472 .compat_ioctl = fuse_file_compat_ioctl,
3473 .poll = fuse_file_poll,
3474 .fallocate = fuse_file_fallocate,
3475 .copy_file_range = fuse_copy_file_range,
3476 };
3477
3478 static const struct address_space_operations fuse_file_aops = {
3479 .readpage = fuse_readpage,
3480 .readahead = fuse_readahead,
3481 .writepage = fuse_writepage,
3482 .writepages = fuse_writepages,
3483 .launder_page = fuse_launder_page,
3484 .set_page_dirty = __set_page_dirty_nobuffers,
3485 .bmap = fuse_bmap,
3486 .direct_IO = fuse_direct_IO,
3487 .write_begin = fuse_write_begin,
3488 .write_end = fuse_write_end,
3489 };
3490
3491 void fuse_init_file_inode(struct inode *inode)
3492 {
3493 struct fuse_inode *fi = get_fuse_inode(inode);
3494
3495 inode->i_fop = &fuse_file_operations;
3496 inode->i_data.a_ops = &fuse_file_aops;
3497
3498 INIT_LIST_HEAD(&fi->write_files);
3499 INIT_LIST_HEAD(&fi->queued_writes);
3500 fi->writectr = 0;
3501 init_waitqueue_head(&fi->page_waitq);
3502 fi->writepages = RB_ROOT;
3503
3504 if (IS_ENABLED(CONFIG_FUSE_DAX))
3505 fuse_dax_inode_init(inode);
3506 }
Linux with added FPC-III support