Merge branch 'for-davem' of ssh://master.kernel.org/pub/scm/linux/kernel/git/linville...
[linux-2.6.git] / fs / fuse / file.c
1 /*
2   FUSE: Filesystem in Userspace
3   Copyright (C) 2001-2008  Miklos Szeredi <miklos@szeredi.hu>
4
5   This program can be distributed under the terms of the GNU GPL.
6   See the file COPYING.
7 */
8
9 #include "fuse_i.h"
10
11 #include <linux/pagemap.h>
12 #include <linux/slab.h>
13 #include <linux/kernel.h>
14 #include <linux/sched.h>
15 #include <linux/module.h>
16 #include <linux/compat.h>
17
18 static const struct file_operations fuse_direct_io_file_operations;
19
20 static int fuse_send_open(struct fuse_conn *fc, u64 nodeid, struct file *file,
21                           int opcode, struct fuse_open_out *outargp)
22 {
23         struct fuse_open_in inarg;
24         struct fuse_req *req;
25         int err;
26
27         req = fuse_get_req(fc);
28         if (IS_ERR(req))
29                 return PTR_ERR(req);
30
31         memset(&inarg, 0, sizeof(inarg));
32         inarg.flags = file->f_flags & ~(O_CREAT | O_EXCL | O_NOCTTY);
33         if (!fc->atomic_o_trunc)
34                 inarg.flags &= ~O_TRUNC;
35         req->in.h.opcode = opcode;
36         req->in.h.nodeid = nodeid;
37         req->in.numargs = 1;
38         req->in.args[0].size = sizeof(inarg);
39         req->in.args[0].value = &inarg;
40         req->out.numargs = 1;
41         req->out.args[0].size = sizeof(*outargp);
42         req->out.args[0].value = outargp;
43         fuse_request_send(fc, req);
44         err = req->out.h.error;
45         fuse_put_request(fc, req);
46
47         return err;
48 }
49
50 struct fuse_file *fuse_file_alloc(struct fuse_conn *fc)
51 {
52         struct fuse_file *ff;
53
54         ff = kmalloc(sizeof(struct fuse_file), GFP_KERNEL);
55         if (unlikely(!ff))
56                 return NULL;
57
58         ff->fc = fc;
59         ff->reserved_req = fuse_request_alloc();
60         if (unlikely(!ff->reserved_req)) {
61                 kfree(ff);
62                 return NULL;
63         }
64
65         INIT_LIST_HEAD(&ff->write_entry);
66         atomic_set(&ff->count, 0);
67         RB_CLEAR_NODE(&ff->polled_node);
68         init_waitqueue_head(&ff->poll_wait);
69
70         spin_lock(&fc->lock);
71         ff->kh = ++fc->khctr;
72         spin_unlock(&fc->lock);
73
74         return ff;
75 }
76
77 void fuse_file_free(struct fuse_file *ff)
78 {
79         fuse_request_free(ff->reserved_req);
80         kfree(ff);
81 }
82
83 struct fuse_file *fuse_file_get(struct fuse_file *ff)
84 {
85         atomic_inc(&ff->count);
86         return ff;
87 }
88
89 static void fuse_release_async(struct work_struct *work)
90 {
91         struct fuse_req *req;
92         struct fuse_conn *fc;
93         struct path path;
94
95         req = container_of(work, struct fuse_req, misc.release.work);
96         path = req->misc.release.path;
97         fc = get_fuse_conn(path.dentry->d_inode);
98
99         fuse_put_request(fc, req);
100         path_put(&path);
101 }
102
103 static void fuse_release_end(struct fuse_conn *fc, struct fuse_req *req)
104 {
105         if (fc->destroy_req) {
106                 /*
107                  * If this is a fuseblk mount, then it's possible that
108                  * releasing the path will result in releasing the
109                  * super block and sending the DESTROY request.  If
110                  * the server is single threaded, this would hang.
111                  * For this reason do the path_put() in a separate
112                  * thread.
113                  */
114                 atomic_inc(&req->count);
115                 INIT_WORK(&req->misc.release.work, fuse_release_async);
116                 schedule_work(&req->misc.release.work);
117         } else {
118                 path_put(&req->misc.release.path);
119         }
120 }
121
122 static void fuse_file_put(struct fuse_file *ff, bool sync)
123 {
124         if (atomic_dec_and_test(&ff->count)) {
125                 struct fuse_req *req = ff->reserved_req;
126
127                 if (sync) {
128                         fuse_request_send(ff->fc, req);
129                         path_put(&req->misc.release.path);
130                         fuse_put_request(ff->fc, req);
131                 } else {
132                         req->end = fuse_release_end;
133                         fuse_request_send_background(ff->fc, req);
134                 }
135                 kfree(ff);
136         }
137 }
138
139 int fuse_do_open(struct fuse_conn *fc, u64 nodeid, struct file *file,
140                  bool isdir)
141 {
142         struct fuse_open_out outarg;
143         struct fuse_file *ff;
144         int err;
145         int opcode = isdir ? FUSE_OPENDIR : FUSE_OPEN;
146
147         ff = fuse_file_alloc(fc);
148         if (!ff)
149                 return -ENOMEM;
150
151         err = fuse_send_open(fc, nodeid, file, opcode, &outarg);
152         if (err) {
153                 fuse_file_free(ff);
154                 return err;
155         }
156
157         if (isdir)
158                 outarg.open_flags &= ~FOPEN_DIRECT_IO;
159
160         ff->fh = outarg.fh;
161         ff->nodeid = nodeid;
162         ff->open_flags = outarg.open_flags;
163         file->private_data = fuse_file_get(ff);
164
165         return 0;
166 }
167 EXPORT_SYMBOL_GPL(fuse_do_open);
168
169 void fuse_finish_open(struct inode *inode, struct file *file)
170 {
171         struct fuse_file *ff = file->private_data;
172         struct fuse_conn *fc = get_fuse_conn(inode);
173
174         if (ff->open_flags & FOPEN_DIRECT_IO)
175                 file->f_op = &fuse_direct_io_file_operations;
176         if (!(ff->open_flags & FOPEN_KEEP_CACHE))
177                 invalidate_inode_pages2(inode->i_mapping);
178         if (ff->open_flags & FOPEN_NONSEEKABLE)
179                 nonseekable_open(inode, file);
180         if (fc->atomic_o_trunc && (file->f_flags & O_TRUNC)) {
181                 struct fuse_inode *fi = get_fuse_inode(inode);
182
183                 spin_lock(&fc->lock);
184                 fi->attr_version = ++fc->attr_version;
185                 i_size_write(inode, 0);
186                 spin_unlock(&fc->lock);
187                 fuse_invalidate_attr(inode);
188         }
189 }
190
191 int fuse_open_common(struct inode *inode, struct file *file, bool isdir)
192 {
193         struct fuse_conn *fc = get_fuse_conn(inode);
194         int err;
195
196         /* VFS checks this, but only _after_ ->open() */
197         if (file->f_flags & O_DIRECT)
198                 return -EINVAL;
199
200         err = generic_file_open(inode, file);
201         if (err)
202                 return err;
203
204         err = fuse_do_open(fc, get_node_id(inode), file, isdir);
205         if (err)
206                 return err;
207
208         fuse_finish_open(inode, file);
209
210         return 0;
211 }
212
213 static void fuse_prepare_release(struct fuse_file *ff, int flags, int opcode)
214 {
215         struct fuse_conn *fc = ff->fc;
216         struct fuse_req *req = ff->reserved_req;
217         struct fuse_release_in *inarg = &req->misc.release.in;
218
219         spin_lock(&fc->lock);
220         list_del(&ff->write_entry);
221         if (!RB_EMPTY_NODE(&ff->polled_node))
222                 rb_erase(&ff->polled_node, &fc->polled_files);
223         spin_unlock(&fc->lock);
224
225         wake_up_interruptible_sync(&ff->poll_wait);
226
227         inarg->fh = ff->fh;
228         inarg->flags = flags;
229         req->in.h.opcode = opcode;
230         req->in.h.nodeid = ff->nodeid;
231         req->in.numargs = 1;
232         req->in.args[0].size = sizeof(struct fuse_release_in);
233         req->in.args[0].value = inarg;
234 }
235
236 void fuse_release_common(struct file *file, int opcode)
237 {
238         struct fuse_file *ff;
239         struct fuse_req *req;
240
241         ff = file->private_data;
242         if (unlikely(!ff))
243                 return;
244
245         req = ff->reserved_req;
246         fuse_prepare_release(ff, file->f_flags, opcode);
247
248         /* Hold vfsmount and dentry until release is finished */
249         path_get(&file->f_path);
250         req->misc.release.path = file->f_path;
251
252         /*
253          * Normally this will send the RELEASE request, however if
254          * some asynchronous READ or WRITE requests are outstanding,
255          * the sending will be delayed.
256          *
257          * Make the release synchronous if this is a fuseblk mount,
258          * synchronous RELEASE is allowed (and desirable) in this case
259          * because the server can be trusted not to screw up.
260          */
261         fuse_file_put(ff, ff->fc->destroy_req != NULL);
262 }
263
264 static int fuse_open(struct inode *inode, struct file *file)
265 {
266         return fuse_open_common(inode, file, false);
267 }
268
269 static int fuse_release(struct inode *inode, struct file *file)
270 {
271         fuse_release_common(file, FUSE_RELEASE);
272
273         /* return value is ignored by VFS */
274         return 0;
275 }
276
277 void fuse_sync_release(struct fuse_file *ff, int flags)
278 {
279         WARN_ON(atomic_read(&ff->count) > 1);
280         fuse_prepare_release(ff, flags, FUSE_RELEASE);
281         ff->reserved_req->force = 1;
282         fuse_request_send(ff->fc, ff->reserved_req);
283         fuse_put_request(ff->fc, ff->reserved_req);
284         kfree(ff);
285 }
286 EXPORT_SYMBOL_GPL(fuse_sync_release);
287
288 /*
289  * Scramble the ID space with XTEA, so that the value of the files_struct
290  * pointer is not exposed to userspace.
291  */
292 u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id)
293 {
294         u32 *k = fc->scramble_key;
295         u64 v = (unsigned long) id;
296         u32 v0 = v;
297         u32 v1 = v >> 32;
298         u32 sum = 0;
299         int i;
300
301         for (i = 0; i < 32; i++) {
302                 v0 += ((v1 << 4 ^ v1 >> 5) + v1) ^ (sum + k[sum & 3]);
303                 sum += 0x9E3779B9;
304                 v1 += ((v0 << 4 ^ v0 >> 5) + v0) ^ (sum + k[sum>>11 & 3]);
305         }
306
307         return (u64) v0 + ((u64) v1 << 32);
308 }
309
310 /*
311  * Check if page is under writeback
312  *
313  * This is currently done by walking the list of writepage requests
314  * for the inode, which can be pretty inefficient.
315  */
316 static bool fuse_page_is_writeback(struct inode *inode, pgoff_t index)
317 {
318         struct fuse_conn *fc = get_fuse_conn(inode);
319         struct fuse_inode *fi = get_fuse_inode(inode);
320         struct fuse_req *req;
321         bool found = false;
322
323         spin_lock(&fc->lock);
324         list_for_each_entry(req, &fi->writepages, writepages_entry) {
325                 pgoff_t curr_index;
326
327                 BUG_ON(req->inode != inode);
328                 curr_index = req->misc.write.in.offset >> PAGE_CACHE_SHIFT;
329                 if (curr_index == index) {
330                         found = true;
331                         break;
332                 }
333         }
334         spin_unlock(&fc->lock);
335
336         return found;
337 }
338
339 /*
340  * Wait for page writeback to be completed.
341  *
342  * Since fuse doesn't rely on the VM writeback tracking, this has to
343  * use some other means.
344  */
345 static int fuse_wait_on_page_writeback(struct inode *inode, pgoff_t index)
346 {
347         struct fuse_inode *fi = get_fuse_inode(inode);
348
349         wait_event(fi->page_waitq, !fuse_page_is_writeback(inode, index));
350         return 0;
351 }
352
353 static int fuse_flush(struct file *file, fl_owner_t id)
354 {
355         struct inode *inode = file->f_path.dentry->d_inode;
356         struct fuse_conn *fc = get_fuse_conn(inode);
357         struct fuse_file *ff = file->private_data;
358         struct fuse_req *req;
359         struct fuse_flush_in inarg;
360         int err;
361
362         if (is_bad_inode(inode))
363                 return -EIO;
364
365         if (fc->no_flush)
366                 return 0;
367
368         req = fuse_get_req_nofail(fc, file);
369         memset(&inarg, 0, sizeof(inarg));
370         inarg.fh = ff->fh;
371         inarg.lock_owner = fuse_lock_owner_id(fc, id);
372         req->in.h.opcode = FUSE_FLUSH;
373         req->in.h.nodeid = get_node_id(inode);
374         req->in.numargs = 1;
375         req->in.args[0].size = sizeof(inarg);
376         req->in.args[0].value = &inarg;
377         req->force = 1;
378         fuse_request_send(fc, req);
379         err = req->out.h.error;
380         fuse_put_request(fc, req);
381         if (err == -ENOSYS) {
382                 fc->no_flush = 1;
383                 err = 0;
384         }
385         return err;
386 }
387
388 /*
389  * Wait for all pending writepages on the inode to finish.
390  *
391  * This is currently done by blocking further writes with FUSE_NOWRITE
392  * and waiting for all sent writes to complete.
393  *
394  * This must be called under i_mutex, otherwise the FUSE_NOWRITE usage
395  * could conflict with truncation.
396  */
397 static void fuse_sync_writes(struct inode *inode)
398 {
399         fuse_set_nowrite(inode);
400         fuse_release_nowrite(inode);
401 }
402
403 int fuse_fsync_common(struct file *file, int datasync, int isdir)
404 {
405         struct inode *inode = file->f_mapping->host;
406         struct fuse_conn *fc = get_fuse_conn(inode);
407         struct fuse_file *ff = file->private_data;
408         struct fuse_req *req;
409         struct fuse_fsync_in inarg;
410         int err;
411
412         if (is_bad_inode(inode))
413                 return -EIO;
414
415         if ((!isdir && fc->no_fsync) || (isdir && fc->no_fsyncdir))
416                 return 0;
417
418         /*
419          * Start writeback against all dirty pages of the inode, then
420          * wait for all outstanding writes, before sending the FSYNC
421          * request.
422          */
423         err = write_inode_now(inode, 0);
424         if (err)
425                 return err;
426
427         fuse_sync_writes(inode);
428
429         req = fuse_get_req(fc);
430         if (IS_ERR(req))
431                 return PTR_ERR(req);
432
433         memset(&inarg, 0, sizeof(inarg));
434         inarg.fh = ff->fh;
435         inarg.fsync_flags = datasync ? 1 : 0;
436         req->in.h.opcode = isdir ? FUSE_FSYNCDIR : FUSE_FSYNC;
437         req->in.h.nodeid = get_node_id(inode);
438         req->in.numargs = 1;
439         req->in.args[0].size = sizeof(inarg);
440         req->in.args[0].value = &inarg;
441         fuse_request_send(fc, req);
442         err = req->out.h.error;
443         fuse_put_request(fc, req);
444         if (err == -ENOSYS) {
445                 if (isdir)
446                         fc->no_fsyncdir = 1;
447                 else
448                         fc->no_fsync = 1;
449                 err = 0;
450         }
451         return err;
452 }
453
454 static int fuse_fsync(struct file *file, int datasync)
455 {
456         return fuse_fsync_common(file, datasync, 0);
457 }
458
459 void fuse_read_fill(struct fuse_req *req, struct file *file, loff_t pos,
460                     size_t count, int opcode)
461 {
462         struct fuse_read_in *inarg = &req->misc.read.in;
463         struct fuse_file *ff = file->private_data;
464
465         inarg->fh = ff->fh;
466         inarg->offset = pos;
467         inarg->size = count;
468         inarg->flags = file->f_flags;
469         req->in.h.opcode = opcode;
470         req->in.h.nodeid = ff->nodeid;
471         req->in.numargs = 1;
472         req->in.args[0].size = sizeof(struct fuse_read_in);
473         req->in.args[0].value = inarg;
474         req->out.argvar = 1;
475         req->out.numargs = 1;
476         req->out.args[0].size = count;
477 }
478
479 static size_t fuse_send_read(struct fuse_req *req, struct file *file,
480                              loff_t pos, size_t count, fl_owner_t owner)
481 {
482         struct fuse_file *ff = file->private_data;
483         struct fuse_conn *fc = ff->fc;
484
485         fuse_read_fill(req, file, pos, count, FUSE_READ);
486         if (owner != NULL) {
487                 struct fuse_read_in *inarg = &req->misc.read.in;
488
489                 inarg->read_flags |= FUSE_READ_LOCKOWNER;
490                 inarg->lock_owner = fuse_lock_owner_id(fc, owner);
491         }
492         fuse_request_send(fc, req);
493         return req->out.args[0].size;
494 }
495
496 static void fuse_read_update_size(struct inode *inode, loff_t size,
497                                   u64 attr_ver)
498 {
499         struct fuse_conn *fc = get_fuse_conn(inode);
500         struct fuse_inode *fi = get_fuse_inode(inode);
501
502         spin_lock(&fc->lock);
503         if (attr_ver == fi->attr_version && size < inode->i_size) {
504                 fi->attr_version = ++fc->attr_version;
505                 i_size_write(inode, size);
506         }
507         spin_unlock(&fc->lock);
508 }
509
510 static int fuse_readpage(struct file *file, struct page *page)
511 {
512         struct inode *inode = page->mapping->host;
513         struct fuse_conn *fc = get_fuse_conn(inode);
514         struct fuse_req *req;
515         size_t num_read;
516         loff_t pos = page_offset(page);
517         size_t count = PAGE_CACHE_SIZE;
518         u64 attr_ver;
519         int err;
520
521         err = -EIO;
522         if (is_bad_inode(inode))
523                 goto out;
524
525         /*
526          * Page writeback can extend beyond the liftime of the
527          * page-cache page, so make sure we read a properly synced
528          * page.
529          */
530         fuse_wait_on_page_writeback(inode, page->index);
531
532         req = fuse_get_req(fc);
533         err = PTR_ERR(req);
534         if (IS_ERR(req))
535                 goto out;
536
537         attr_ver = fuse_get_attr_version(fc);
538
539         req->out.page_zeroing = 1;
540         req->out.argpages = 1;
541         req->num_pages = 1;
542         req->pages[0] = page;
543         num_read = fuse_send_read(req, file, pos, count, NULL);
544         err = req->out.h.error;
545         fuse_put_request(fc, req);
546
547         if (!err) {
548                 /*
549                  * Short read means EOF.  If file size is larger, truncate it
550                  */
551                 if (num_read < count)
552                         fuse_read_update_size(inode, pos + num_read, attr_ver);
553
554                 SetPageUptodate(page);
555         }
556
557         fuse_invalidate_attr(inode); /* atime changed */
558  out:
559         unlock_page(page);
560         return err;
561 }
562
563 static void fuse_readpages_end(struct fuse_conn *fc, struct fuse_req *req)
564 {
565         int i;
566         size_t count = req->misc.read.in.size;
567         size_t num_read = req->out.args[0].size;
568         struct address_space *mapping = NULL;
569
570         for (i = 0; mapping == NULL && i < req->num_pages; i++)
571                 mapping = req->pages[i]->mapping;
572
573         if (mapping) {
574                 struct inode *inode = mapping->host;
575
576                 /*
577                  * Short read means EOF. If file size is larger, truncate it
578                  */
579                 if (!req->out.h.error && num_read < count) {
580                         loff_t pos;
581
582                         pos = page_offset(req->pages[0]) + num_read;
583                         fuse_read_update_size(inode, pos,
584                                               req->misc.read.attr_ver);
585                 }
586                 fuse_invalidate_attr(inode); /* atime changed */
587         }
588
589         for (i = 0; i < req->num_pages; i++) {
590                 struct page *page = req->pages[i];
591                 if (!req->out.h.error)
592                         SetPageUptodate(page);
593                 else
594                         SetPageError(page);
595                 unlock_page(page);
596                 page_cache_release(page);
597         }
598         if (req->ff)
599                 fuse_file_put(req->ff, false);
600 }
601
602 static void fuse_send_readpages(struct fuse_req *req, struct file *file)
603 {
604         struct fuse_file *ff = file->private_data;
605         struct fuse_conn *fc = ff->fc;
606         loff_t pos = page_offset(req->pages[0]);
607         size_t count = req->num_pages << PAGE_CACHE_SHIFT;
608
609         req->out.argpages = 1;
610         req->out.page_zeroing = 1;
611         req->out.page_replace = 1;
612         fuse_read_fill(req, file, pos, count, FUSE_READ);
613         req->misc.read.attr_ver = fuse_get_attr_version(fc);
614         if (fc->async_read) {
615                 req->ff = fuse_file_get(ff);
616                 req->end = fuse_readpages_end;
617                 fuse_request_send_background(fc, req);
618         } else {
619                 fuse_request_send(fc, req);
620                 fuse_readpages_end(fc, req);
621                 fuse_put_request(fc, req);
622         }
623 }
624
625 struct fuse_fill_data {
626         struct fuse_req *req;
627         struct file *file;
628         struct inode *inode;
629 };
630
631 static int fuse_readpages_fill(void *_data, struct page *page)
632 {
633         struct fuse_fill_data *data = _data;
634         struct fuse_req *req = data->req;
635         struct inode *inode = data->inode;
636         struct fuse_conn *fc = get_fuse_conn(inode);
637
638         fuse_wait_on_page_writeback(inode, page->index);
639
640         if (req->num_pages &&
641             (req->num_pages == FUSE_MAX_PAGES_PER_REQ ||
642              (req->num_pages + 1) * PAGE_CACHE_SIZE > fc->max_read ||
643              req->pages[req->num_pages - 1]->index + 1 != page->index)) {
644                 fuse_send_readpages(req, data->file);
645                 data->req = req = fuse_get_req(fc);
646                 if (IS_ERR(req)) {
647                         unlock_page(page);
648                         return PTR_ERR(req);
649                 }
650         }
651         page_cache_get(page);
652         req->pages[req->num_pages] = page;
653         req->num_pages++;
654         return 0;
655 }
656
657 static int fuse_readpages(struct file *file, struct address_space *mapping,
658                           struct list_head *pages, unsigned nr_pages)
659 {
660         struct inode *inode = mapping->host;
661         struct fuse_conn *fc = get_fuse_conn(inode);
662         struct fuse_fill_data data;
663         int err;
664
665         err = -EIO;
666         if (is_bad_inode(inode))
667                 goto out;
668
669         data.file = file;
670         data.inode = inode;
671         data.req = fuse_get_req(fc);
672         err = PTR_ERR(data.req);
673         if (IS_ERR(data.req))
674                 goto out;
675
676         err = read_cache_pages(mapping, pages, fuse_readpages_fill, &data);
677         if (!err) {
678                 if (data.req->num_pages)
679                         fuse_send_readpages(data.req, file);
680                 else
681                         fuse_put_request(fc, data.req);
682         }
683 out:
684         return err;
685 }
686
687 static ssize_t fuse_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
688                                   unsigned long nr_segs, loff_t pos)
689 {
690         struct inode *inode = iocb->ki_filp->f_mapping->host;
691
692         if (pos + iov_length(iov, nr_segs) > i_size_read(inode)) {
693                 int err;
694                 /*
695                  * If trying to read past EOF, make sure the i_size
696                  * attribute is up-to-date.
697                  */
698                 err = fuse_update_attributes(inode, NULL, iocb->ki_filp, NULL);
699                 if (err)
700                         return err;
701         }
702
703         return generic_file_aio_read(iocb, iov, nr_segs, pos);
704 }
705
706 static void fuse_write_fill(struct fuse_req *req, struct fuse_file *ff,
707                             loff_t pos, size_t count)
708 {
709         struct fuse_write_in *inarg = &req->misc.write.in;
710         struct fuse_write_out *outarg = &req->misc.write.out;
711
712         inarg->fh = ff->fh;
713         inarg->offset = pos;
714         inarg->size = count;
715         req->in.h.opcode = FUSE_WRITE;
716         req->in.h.nodeid = ff->nodeid;
717         req->in.numargs = 2;
718         if (ff->fc->minor < 9)
719                 req->in.args[0].size = FUSE_COMPAT_WRITE_IN_SIZE;
720         else
721                 req->in.args[0].size = sizeof(struct fuse_write_in);
722         req->in.args[0].value = inarg;
723         req->in.args[1].size = count;
724         req->out.numargs = 1;
725         req->out.args[0].size = sizeof(struct fuse_write_out);
726         req->out.args[0].value = outarg;
727 }
728
729 static size_t fuse_send_write(struct fuse_req *req, struct file *file,
730                               loff_t pos, size_t count, fl_owner_t owner)
731 {
732         struct fuse_file *ff = file->private_data;
733         struct fuse_conn *fc = ff->fc;
734         struct fuse_write_in *inarg = &req->misc.write.in;
735
736         fuse_write_fill(req, ff, pos, count);
737         inarg->flags = file->f_flags;
738         if (owner != NULL) {
739                 inarg->write_flags |= FUSE_WRITE_LOCKOWNER;
740                 inarg->lock_owner = fuse_lock_owner_id(fc, owner);
741         }
742         fuse_request_send(fc, req);
743         return req->misc.write.out.size;
744 }
745
746 static int fuse_write_begin(struct file *file, struct address_space *mapping,
747                         loff_t pos, unsigned len, unsigned flags,
748                         struct page **pagep, void **fsdata)
749 {
750         pgoff_t index = pos >> PAGE_CACHE_SHIFT;
751
752         *pagep = grab_cache_page_write_begin(mapping, index, flags);
753         if (!*pagep)
754                 return -ENOMEM;
755         return 0;
756 }
757
758 void fuse_write_update_size(struct inode *inode, loff_t pos)
759 {
760         struct fuse_conn *fc = get_fuse_conn(inode);
761         struct fuse_inode *fi = get_fuse_inode(inode);
762
763         spin_lock(&fc->lock);
764         fi->attr_version = ++fc->attr_version;
765         if (pos > inode->i_size)
766                 i_size_write(inode, pos);
767         spin_unlock(&fc->lock);
768 }
769
770 static int fuse_buffered_write(struct file *file, struct inode *inode,
771                                loff_t pos, unsigned count, struct page *page)
772 {
773         int err;
774         size_t nres;
775         struct fuse_conn *fc = get_fuse_conn(inode);
776         unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
777         struct fuse_req *req;
778
779         if (is_bad_inode(inode))
780                 return -EIO;
781
782         /*
783          * Make sure writepages on the same page are not mixed up with
784          * plain writes.
785          */
786         fuse_wait_on_page_writeback(inode, page->index);
787
788         req = fuse_get_req(fc);
789         if (IS_ERR(req))
790                 return PTR_ERR(req);
791
792         req->in.argpages = 1;
793         req->num_pages = 1;
794         req->pages[0] = page;
795         req->page_offset = offset;
796         nres = fuse_send_write(req, file, pos, count, NULL);
797         err = req->out.h.error;
798         fuse_put_request(fc, req);
799         if (!err && !nres)
800                 err = -EIO;
801         if (!err) {
802                 pos += nres;
803                 fuse_write_update_size(inode, pos);
804                 if (count == PAGE_CACHE_SIZE)
805                         SetPageUptodate(page);
806         }
807         fuse_invalidate_attr(inode);
808         return err ? err : nres;
809 }
810
811 static int fuse_write_end(struct file *file, struct address_space *mapping,
812                         loff_t pos, unsigned len, unsigned copied,
813                         struct page *page, void *fsdata)
814 {
815         struct inode *inode = mapping->host;
816         int res = 0;
817
818         if (copied)
819                 res = fuse_buffered_write(file, inode, pos, copied, page);
820
821         unlock_page(page);
822         page_cache_release(page);
823         return res;
824 }
825
826 static size_t fuse_send_write_pages(struct fuse_req *req, struct file *file,
827                                     struct inode *inode, loff_t pos,
828                                     size_t count)
829 {
830         size_t res;
831         unsigned offset;
832         unsigned i;
833
834         for (i = 0; i < req->num_pages; i++)
835                 fuse_wait_on_page_writeback(inode, req->pages[i]->index);
836
837         res = fuse_send_write(req, file, pos, count, NULL);
838
839         offset = req->page_offset;
840         count = res;
841         for (i = 0; i < req->num_pages; i++) {
842                 struct page *page = req->pages[i];
843
844                 if (!req->out.h.error && !offset && count >= PAGE_CACHE_SIZE)
845                         SetPageUptodate(page);
846
847                 if (count > PAGE_CACHE_SIZE - offset)
848                         count -= PAGE_CACHE_SIZE - offset;
849                 else
850                         count = 0;
851                 offset = 0;
852
853                 unlock_page(page);
854                 page_cache_release(page);
855         }
856
857         return res;
858 }
859
860 static ssize_t fuse_fill_write_pages(struct fuse_req *req,
861                                struct address_space *mapping,
862                                struct iov_iter *ii, loff_t pos)
863 {
864         struct fuse_conn *fc = get_fuse_conn(mapping->host);
865         unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
866         size_t count = 0;
867         int err;
868
869         req->in.argpages = 1;
870         req->page_offset = offset;
871
872         do {
873                 size_t tmp;
874                 struct page *page;
875                 pgoff_t index = pos >> PAGE_CACHE_SHIFT;
876                 size_t bytes = min_t(size_t, PAGE_CACHE_SIZE - offset,
877                                      iov_iter_count(ii));
878
879                 bytes = min_t(size_t, bytes, fc->max_write - count);
880
881  again:
882                 err = -EFAULT;
883                 if (iov_iter_fault_in_readable(ii, bytes))
884                         break;
885
886                 err = -ENOMEM;
887                 page = grab_cache_page_write_begin(mapping, index, 0);
888                 if (!page)
889                         break;
890
891                 if (mapping_writably_mapped(mapping))
892                         flush_dcache_page(page);
893
894                 pagefault_disable();
895                 tmp = iov_iter_copy_from_user_atomic(page, ii, offset, bytes);
896                 pagefault_enable();
897                 flush_dcache_page(page);
898
899                 if (!tmp) {
900                         unlock_page(page);
901                         page_cache_release(page);
902                         bytes = min(bytes, iov_iter_single_seg_count(ii));
903                         goto again;
904                 }
905
906                 err = 0;
907                 req->pages[req->num_pages] = page;
908                 req->num_pages++;
909
910                 iov_iter_advance(ii, tmp);
911                 count += tmp;
912                 pos += tmp;
913                 offset += tmp;
914                 if (offset == PAGE_CACHE_SIZE)
915                         offset = 0;
916
917                 if (!fc->big_writes)
918                         break;
919         } while (iov_iter_count(ii) && count < fc->max_write &&
920                  req->num_pages < FUSE_MAX_PAGES_PER_REQ && offset == 0);
921
922         return count > 0 ? count : err;
923 }
924
925 static ssize_t fuse_perform_write(struct file *file,
926                                   struct address_space *mapping,
927                                   struct iov_iter *ii, loff_t pos)
928 {
929         struct inode *inode = mapping->host;
930         struct fuse_conn *fc = get_fuse_conn(inode);
931         int err = 0;
932         ssize_t res = 0;
933
934         if (is_bad_inode(inode))
935                 return -EIO;
936
937         do {
938                 struct fuse_req *req;
939                 ssize_t count;
940
941                 req = fuse_get_req(fc);
942                 if (IS_ERR(req)) {
943                         err = PTR_ERR(req);
944                         break;
945                 }
946
947                 count = fuse_fill_write_pages(req, mapping, ii, pos);
948                 if (count <= 0) {
949                         err = count;
950                 } else {
951                         size_t num_written;
952
953                         num_written = fuse_send_write_pages(req, file, inode,
954                                                             pos, count);
955                         err = req->out.h.error;
956                         if (!err) {
957                                 res += num_written;
958                                 pos += num_written;
959
960                                 /* break out of the loop on short write */
961                                 if (num_written != count)
962                                         err = -EIO;
963                         }
964                 }
965                 fuse_put_request(fc, req);
966         } while (!err && iov_iter_count(ii));
967
968         if (res > 0)
969                 fuse_write_update_size(inode, pos);
970
971         fuse_invalidate_attr(inode);
972
973         return res > 0 ? res : err;
974 }
975
976 static ssize_t fuse_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
977                                    unsigned long nr_segs, loff_t pos)
978 {
979         struct file *file = iocb->ki_filp;
980         struct address_space *mapping = file->f_mapping;
981         size_t count = 0;
982         ssize_t written = 0;
983         struct inode *inode = mapping->host;
984         ssize_t err;
985         struct iov_iter i;
986
987         WARN_ON(iocb->ki_pos != pos);
988
989         err = generic_segment_checks(iov, &nr_segs, &count, VERIFY_READ);
990         if (err)
991                 return err;
992
993         mutex_lock(&inode->i_mutex);
994         vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
995
996         /* We can write back this queue in page reclaim */
997         current->backing_dev_info = mapping->backing_dev_info;
998
999         err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
1000         if (err)
1001                 goto out;
1002
1003         if (count == 0)
1004                 goto out;
1005
1006         err = file_remove_suid(file);
1007         if (err)
1008                 goto out;
1009
1010         file_update_time(file);
1011
1012         iov_iter_init(&i, iov, nr_segs, count, 0);
1013         written = fuse_perform_write(file, mapping, &i, pos);
1014         if (written >= 0)
1015                 iocb->ki_pos = pos + written;
1016
1017 out:
1018         current->backing_dev_info = NULL;
1019         mutex_unlock(&inode->i_mutex);
1020
1021         return written ? written : err;
1022 }
1023
1024 static void fuse_release_user_pages(struct fuse_req *req, int write)
1025 {
1026         unsigned i;
1027
1028         for (i = 0; i < req->num_pages; i++) {
1029                 struct page *page = req->pages[i];
1030                 if (write)
1031                         set_page_dirty_lock(page);
1032                 put_page(page);
1033         }
1034 }
1035
1036 static int fuse_get_user_pages(struct fuse_req *req, const char __user *buf,
1037                                size_t *nbytesp, int write)
1038 {
1039         size_t nbytes = *nbytesp;
1040         unsigned long user_addr = (unsigned long) buf;
1041         unsigned offset = user_addr & ~PAGE_MASK;
1042         int npages;
1043
1044         /* Special case for kernel I/O: can copy directly into the buffer */
1045         if (segment_eq(get_fs(), KERNEL_DS)) {
1046                 if (write)
1047                         req->in.args[1].value = (void *) user_addr;
1048                 else
1049                         req->out.args[0].value = (void *) user_addr;
1050
1051                 return 0;
1052         }
1053
1054         nbytes = min_t(size_t, nbytes, FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT);
1055         npages = (nbytes + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
1056         npages = clamp(npages, 1, FUSE_MAX_PAGES_PER_REQ);
1057         npages = get_user_pages_fast(user_addr, npages, !write, req->pages);
1058         if (npages < 0)
1059                 return npages;
1060
1061         req->num_pages = npages;
1062         req->page_offset = offset;
1063
1064         if (write)
1065                 req->in.argpages = 1;
1066         else
1067                 req->out.argpages = 1;
1068
1069         nbytes = (req->num_pages << PAGE_SHIFT) - req->page_offset;
1070         *nbytesp = min(*nbytesp, nbytes);
1071
1072         return 0;
1073 }
1074
1075 ssize_t fuse_direct_io(struct file *file, const char __user *buf,
1076                        size_t count, loff_t *ppos, int write)
1077 {
1078         struct fuse_file *ff = file->private_data;
1079         struct fuse_conn *fc = ff->fc;
1080         size_t nmax = write ? fc->max_write : fc->max_read;
1081         loff_t pos = *ppos;
1082         ssize_t res = 0;
1083         struct fuse_req *req;
1084
1085         req = fuse_get_req(fc);
1086         if (IS_ERR(req))
1087                 return PTR_ERR(req);
1088
1089         while (count) {
1090                 size_t nres;
1091                 fl_owner_t owner = current->files;
1092                 size_t nbytes = min(count, nmax);
1093                 int err = fuse_get_user_pages(req, buf, &nbytes, write);
1094                 if (err) {
1095                         res = err;
1096                         break;
1097                 }
1098
1099                 if (write)
1100                         nres = fuse_send_write(req, file, pos, nbytes, owner);
1101                 else
1102                         nres = fuse_send_read(req, file, pos, nbytes, owner);
1103
1104                 fuse_release_user_pages(req, !write);
1105                 if (req->out.h.error) {
1106                         if (!res)
1107                                 res = req->out.h.error;
1108                         break;
1109                 } else if (nres > nbytes) {
1110                         res = -EIO;
1111                         break;
1112                 }
1113                 count -= nres;
1114                 res += nres;
1115                 pos += nres;
1116                 buf += nres;
1117                 if (nres != nbytes)
1118                         break;
1119                 if (count) {
1120                         fuse_put_request(fc, req);
1121                         req = fuse_get_req(fc);
1122                         if (IS_ERR(req))
1123                                 break;
1124                 }
1125         }
1126         if (!IS_ERR(req))
1127                 fuse_put_request(fc, req);
1128         if (res > 0)
1129                 *ppos = pos;
1130
1131         return res;
1132 }
1133 EXPORT_SYMBOL_GPL(fuse_direct_io);
1134
1135 static ssize_t fuse_direct_read(struct file *file, char __user *buf,
1136                                      size_t count, loff_t *ppos)
1137 {
1138         ssize_t res;
1139         struct inode *inode = file->f_path.dentry->d_inode;
1140
1141         if (is_bad_inode(inode))
1142                 return -EIO;
1143
1144         res = fuse_direct_io(file, buf, count, ppos, 0);
1145
1146         fuse_invalidate_attr(inode);
1147
1148         return res;
1149 }
1150
1151 static ssize_t fuse_direct_write(struct file *file, const char __user *buf,
1152                                  size_t count, loff_t *ppos)
1153 {
1154         struct inode *inode = file->f_path.dentry->d_inode;
1155         ssize_t res;
1156
1157         if (is_bad_inode(inode))
1158                 return -EIO;
1159
1160         /* Don't allow parallel writes to the same file */
1161         mutex_lock(&inode->i_mutex);
1162         res = generic_write_checks(file, ppos, &count, 0);
1163         if (!res) {
1164                 res = fuse_direct_io(file, buf, count, ppos, 1);
1165                 if (res > 0)
1166                         fuse_write_update_size(inode, *ppos);
1167         }
1168         mutex_unlock(&inode->i_mutex);
1169
1170         fuse_invalidate_attr(inode);
1171
1172         return res;
1173 }
1174
1175 static void fuse_writepage_free(struct fuse_conn *fc, struct fuse_req *req)
1176 {
1177         __free_page(req->pages[0]);
1178         fuse_file_put(req->ff, false);
1179 }
1180
1181 static void fuse_writepage_finish(struct fuse_conn *fc, struct fuse_req *req)
1182 {
1183         struct inode *inode = req->inode;
1184         struct fuse_inode *fi = get_fuse_inode(inode);
1185         struct backing_dev_info *bdi = inode->i_mapping->backing_dev_info;
1186
1187         list_del(&req->writepages_entry);
1188         dec_bdi_stat(bdi, BDI_WRITEBACK);
1189         dec_zone_page_state(req->pages[0], NR_WRITEBACK_TEMP);
1190         bdi_writeout_inc(bdi);
1191         wake_up(&fi->page_waitq);
1192 }
1193
1194 /* Called under fc->lock, may release and reacquire it */
1195 static void fuse_send_writepage(struct fuse_conn *fc, struct fuse_req *req)
1196 __releases(fc->lock)
1197 __acquires(fc->lock)
1198 {
1199         struct fuse_inode *fi = get_fuse_inode(req->inode);
1200         loff_t size = i_size_read(req->inode);
1201         struct fuse_write_in *inarg = &req->misc.write.in;
1202
1203         if (!fc->connected)
1204                 goto out_free;
1205
1206         if (inarg->offset + PAGE_CACHE_SIZE <= size) {
1207                 inarg->size = PAGE_CACHE_SIZE;
1208         } else if (inarg->offset < size) {
1209                 inarg->size = size & (PAGE_CACHE_SIZE - 1);
1210         } else {
1211                 /* Got truncated off completely */
1212                 goto out_free;
1213         }
1214
1215         req->in.args[1].size = inarg->size;
1216         fi->writectr++;
1217         fuse_request_send_background_locked(fc, req);
1218         return;
1219
1220  out_free:
1221         fuse_writepage_finish(fc, req);
1222         spin_unlock(&fc->lock);
1223         fuse_writepage_free(fc, req);
1224         fuse_put_request(fc, req);
1225         spin_lock(&fc->lock);
1226 }
1227
1228 /*
1229  * If fi->writectr is positive (no truncate or fsync going on) send
1230  * all queued writepage requests.
1231  *
1232  * Called with fc->lock
1233  */
1234 void fuse_flush_writepages(struct inode *inode)
1235 __releases(fc->lock)
1236 __acquires(fc->lock)
1237 {
1238         struct fuse_conn *fc = get_fuse_conn(inode);
1239         struct fuse_inode *fi = get_fuse_inode(inode);
1240         struct fuse_req *req;
1241
1242         while (fi->writectr >= 0 && !list_empty(&fi->queued_writes)) {
1243                 req = list_entry(fi->queued_writes.next, struct fuse_req, list);
1244                 list_del_init(&req->list);
1245                 fuse_send_writepage(fc, req);
1246         }
1247 }
1248
1249 static void fuse_writepage_end(struct fuse_conn *fc, struct fuse_req *req)
1250 {
1251         struct inode *inode = req->inode;
1252         struct fuse_inode *fi = get_fuse_inode(inode);
1253
1254         mapping_set_error(inode->i_mapping, req->out.h.error);
1255         spin_lock(&fc->lock);
1256         fi->writectr--;
1257         fuse_writepage_finish(fc, req);
1258         spin_unlock(&fc->lock);
1259         fuse_writepage_free(fc, req);
1260 }
1261
1262 static int fuse_writepage_locked(struct page *page)
1263 {
1264         struct address_space *mapping = page->mapping;
1265         struct inode *inode = mapping->host;
1266         struct fuse_conn *fc = get_fuse_conn(inode);
1267         struct fuse_inode *fi = get_fuse_inode(inode);
1268         struct fuse_req *req;
1269         struct fuse_file *ff;
1270         struct page *tmp_page;
1271
1272         set_page_writeback(page);
1273
1274         req = fuse_request_alloc_nofs();
1275         if (!req)
1276                 goto err;
1277
1278         tmp_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
1279         if (!tmp_page)
1280                 goto err_free;
1281
1282         spin_lock(&fc->lock);
1283         BUG_ON(list_empty(&fi->write_files));
1284         ff = list_entry(fi->write_files.next, struct fuse_file, write_entry);
1285         req->ff = fuse_file_get(ff);
1286         spin_unlock(&fc->lock);
1287
1288         fuse_write_fill(req, ff, page_offset(page), 0);
1289
1290         copy_highpage(tmp_page, page);
1291         req->misc.write.in.write_flags |= FUSE_WRITE_CACHE;
1292         req->in.argpages = 1;
1293         req->num_pages = 1;
1294         req->pages[0] = tmp_page;
1295         req->page_offset = 0;
1296         req->end = fuse_writepage_end;
1297         req->inode = inode;
1298
1299         inc_bdi_stat(mapping->backing_dev_info, BDI_WRITEBACK);
1300         inc_zone_page_state(tmp_page, NR_WRITEBACK_TEMP);
1301         end_page_writeback(page);
1302
1303         spin_lock(&fc->lock);
1304         list_add(&req->writepages_entry, &fi->writepages);
1305         list_add_tail(&req->list, &fi->queued_writes);
1306         fuse_flush_writepages(inode);
1307         spin_unlock(&fc->lock);
1308
1309         return 0;
1310
1311 err_free:
1312         fuse_request_free(req);
1313 err:
1314         end_page_writeback(page);
1315         return -ENOMEM;
1316 }
1317
1318 static int fuse_writepage(struct page *page, struct writeback_control *wbc)
1319 {
1320         int err;
1321
1322         err = fuse_writepage_locked(page);
1323         unlock_page(page);
1324
1325         return err;
1326 }
1327
1328 static int fuse_launder_page(struct page *page)
1329 {
1330         int err = 0;
1331         if (clear_page_dirty_for_io(page)) {
1332                 struct inode *inode = page->mapping->host;
1333                 err = fuse_writepage_locked(page);
1334                 if (!err)
1335                         fuse_wait_on_page_writeback(inode, page->index);
1336         }
1337         return err;
1338 }
1339
1340 /*
1341  * Write back dirty pages now, because there may not be any suitable
1342  * open files later
1343  */
1344 static void fuse_vma_close(struct vm_area_struct *vma)
1345 {
1346         filemap_write_and_wait(vma->vm_file->f_mapping);
1347 }
1348
1349 /*
1350  * Wait for writeback against this page to complete before allowing it
1351  * to be marked dirty again, and hence written back again, possibly
1352  * before the previous writepage completed.
1353  *
1354  * Block here, instead of in ->writepage(), so that the userspace fs
1355  * can only block processes actually operating on the filesystem.
1356  *
1357  * Otherwise unprivileged userspace fs would be able to block
1358  * unrelated:
1359  *
1360  * - page migration
1361  * - sync(2)
1362  * - try_to_free_pages() with order > PAGE_ALLOC_COSTLY_ORDER
1363  */
1364 static int fuse_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
1365 {
1366         struct page *page = vmf->page;
1367         /*
1368          * Don't use page->mapping as it may become NULL from a
1369          * concurrent truncate.
1370          */
1371         struct inode *inode = vma->vm_file->f_mapping->host;
1372
1373         fuse_wait_on_page_writeback(inode, page->index);
1374         return 0;
1375 }
1376
1377 static const struct vm_operations_struct fuse_file_vm_ops = {
1378         .close          = fuse_vma_close,
1379         .fault          = filemap_fault,
1380         .page_mkwrite   = fuse_page_mkwrite,
1381 };
1382
1383 static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma)
1384 {
1385         if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_MAYWRITE)) {
1386                 struct inode *inode = file->f_dentry->d_inode;
1387                 struct fuse_conn *fc = get_fuse_conn(inode);
1388                 struct fuse_inode *fi = get_fuse_inode(inode);
1389                 struct fuse_file *ff = file->private_data;
1390                 /*
1391                  * file may be written through mmap, so chain it onto the
1392                  * inodes's write_file list
1393                  */
1394                 spin_lock(&fc->lock);
1395                 if (list_empty(&ff->write_entry))
1396                         list_add(&ff->write_entry, &fi->write_files);
1397                 spin_unlock(&fc->lock);
1398         }
1399         file_accessed(file);
1400         vma->vm_ops = &fuse_file_vm_ops;
1401         return 0;
1402 }
1403
1404 static int fuse_direct_mmap(struct file *file, struct vm_area_struct *vma)
1405 {
1406         /* Can't provide the coherency needed for MAP_SHARED */
1407         if (vma->vm_flags & VM_MAYSHARE)
1408                 return -ENODEV;
1409
1410         invalidate_inode_pages2(file->f_mapping);
1411
1412         return generic_file_mmap(file, vma);
1413 }
1414
1415 static int convert_fuse_file_lock(const struct fuse_file_lock *ffl,
1416                                   struct file_lock *fl)
1417 {
1418         switch (ffl->type) {
1419         case F_UNLCK:
1420                 break;
1421
1422         case F_RDLCK:
1423         case F_WRLCK:
1424                 if (ffl->start > OFFSET_MAX || ffl->end > OFFSET_MAX ||
1425                     ffl->end < ffl->start)
1426                         return -EIO;
1427
1428                 fl->fl_start = ffl->start;
1429                 fl->fl_end = ffl->end;
1430                 fl->fl_pid = ffl->pid;
1431                 break;
1432
1433         default:
1434                 return -EIO;
1435         }
1436         fl->fl_type = ffl->type;
1437         return 0;
1438 }
1439
1440 static void fuse_lk_fill(struct fuse_req *req, struct file *file,
1441                          const struct file_lock *fl, int opcode, pid_t pid,
1442                          int flock)
1443 {
1444         struct inode *inode = file->f_path.dentry->d_inode;
1445         struct fuse_conn *fc = get_fuse_conn(inode);
1446         struct fuse_file *ff = file->private_data;
1447         struct fuse_lk_in *arg = &req->misc.lk_in;
1448
1449         arg->fh = ff->fh;
1450         arg->owner = fuse_lock_owner_id(fc, fl->fl_owner);
1451         arg->lk.start = fl->fl_start;
1452         arg->lk.end = fl->fl_end;
1453         arg->lk.type = fl->fl_type;
1454         arg->lk.pid = pid;
1455         if (flock)
1456                 arg->lk_flags |= FUSE_LK_FLOCK;
1457         req->in.h.opcode = opcode;
1458         req->in.h.nodeid = get_node_id(inode);
1459         req->in.numargs = 1;
1460         req->in.args[0].size = sizeof(*arg);
1461         req->in.args[0].value = arg;
1462 }
1463
1464 static int fuse_getlk(struct file *file, struct file_lock *fl)
1465 {
1466         struct inode *inode = file->f_path.dentry->d_inode;
1467         struct fuse_conn *fc = get_fuse_conn(inode);
1468         struct fuse_req *req;
1469         struct fuse_lk_out outarg;
1470         int err;
1471
1472         req = fuse_get_req(fc);
1473         if (IS_ERR(req))
1474                 return PTR_ERR(req);
1475
1476         fuse_lk_fill(req, file, fl, FUSE_GETLK, 0, 0);
1477         req->out.numargs = 1;
1478         req->out.args[0].size = sizeof(outarg);
1479         req->out.args[0].value = &outarg;
1480         fuse_request_send(fc, req);
1481         err = req->out.h.error;
1482         fuse_put_request(fc, req);
1483         if (!err)
1484                 err = convert_fuse_file_lock(&outarg.lk, fl);
1485
1486         return err;
1487 }
1488
1489 static int fuse_setlk(struct file *file, struct file_lock *fl, int flock)
1490 {
1491         struct inode *inode = file->f_path.dentry->d_inode;
1492         struct fuse_conn *fc = get_fuse_conn(inode);
1493         struct fuse_req *req;
1494         int opcode = (fl->fl_flags & FL_SLEEP) ? FUSE_SETLKW : FUSE_SETLK;
1495         pid_t pid = fl->fl_type != F_UNLCK ? current->tgid : 0;
1496         int err;
1497
1498         if (fl->fl_lmops && fl->fl_lmops->fl_grant) {
1499                 /* NLM needs asynchronous locks, which we don't support yet */
1500                 return -ENOLCK;
1501         }
1502
1503         /* Unlock on close is handled by the flush method */
1504         if (fl->fl_flags & FL_CLOSE)
1505                 return 0;
1506
1507         req = fuse_get_req(fc);
1508         if (IS_ERR(req))
1509                 return PTR_ERR(req);
1510
1511         fuse_lk_fill(req, file, fl, opcode, pid, flock);
1512         fuse_request_send(fc, req);
1513         err = req->out.h.error;
1514         /* locking is restartable */
1515         if (err == -EINTR)
1516                 err = -ERESTARTSYS;
1517         fuse_put_request(fc, req);
1518         return err;
1519 }
1520
1521 static int fuse_file_lock(struct file *file, int cmd, struct file_lock *fl)
1522 {
1523         struct inode *inode = file->f_path.dentry->d_inode;
1524         struct fuse_conn *fc = get_fuse_conn(inode);
1525         int err;
1526
1527         if (cmd == F_CANCELLK) {
1528                 err = 0;
1529         } else if (cmd == F_GETLK) {
1530                 if (fc->no_lock) {
1531                         posix_test_lock(file, fl);
1532                         err = 0;
1533                 } else
1534                         err = fuse_getlk(file, fl);
1535         } else {
1536                 if (fc->no_lock)
1537                         err = posix_lock_file(file, fl, NULL);
1538                 else
1539                         err = fuse_setlk(file, fl, 0);
1540         }
1541         return err;
1542 }
1543
1544 static int fuse_file_flock(struct file *file, int cmd, struct file_lock *fl)
1545 {
1546         struct inode *inode = file->f_path.dentry->d_inode;
1547         struct fuse_conn *fc = get_fuse_conn(inode);
1548         int err;
1549
1550         if (fc->no_lock) {
1551                 err = flock_lock_file_wait(file, fl);
1552         } else {
1553                 /* emulate flock with POSIX locks */
1554                 fl->fl_owner = (fl_owner_t) file;
1555                 err = fuse_setlk(file, fl, 1);
1556         }
1557
1558         return err;
1559 }
1560
1561 static sector_t fuse_bmap(struct address_space *mapping, sector_t block)
1562 {
1563         struct inode *inode = mapping->host;
1564         struct fuse_conn *fc = get_fuse_conn(inode);
1565         struct fuse_req *req;
1566         struct fuse_bmap_in inarg;
1567         struct fuse_bmap_out outarg;
1568         int err;
1569
1570         if (!inode->i_sb->s_bdev || fc->no_bmap)
1571                 return 0;
1572
1573         req = fuse_get_req(fc);
1574         if (IS_ERR(req))
1575                 return 0;
1576
1577         memset(&inarg, 0, sizeof(inarg));
1578         inarg.block = block;
1579         inarg.blocksize = inode->i_sb->s_blocksize;
1580         req->in.h.opcode = FUSE_BMAP;
1581         req->in.h.nodeid = get_node_id(inode);
1582         req->in.numargs = 1;
1583         req->in.args[0].size = sizeof(inarg);
1584         req->in.args[0].value = &inarg;
1585         req->out.numargs = 1;
1586         req->out.args[0].size = sizeof(outarg);
1587         req->out.args[0].value = &outarg;
1588         fuse_request_send(fc, req);
1589         err = req->out.h.error;
1590         fuse_put_request(fc, req);
1591         if (err == -ENOSYS)
1592                 fc->no_bmap = 1;
1593
1594         return err ? 0 : outarg.block;
1595 }
1596
1597 static loff_t fuse_file_llseek(struct file *file, loff_t offset, int origin)
1598 {
1599         loff_t retval;
1600         struct inode *inode = file->f_path.dentry->d_inode;
1601
1602         mutex_lock(&inode->i_mutex);
1603         switch (origin) {
1604         case SEEK_END:
1605                 retval = fuse_update_attributes(inode, NULL, file, NULL);
1606                 if (retval)
1607                         goto exit;
1608                 offset += i_size_read(inode);
1609                 break;
1610         case SEEK_CUR:
1611                 offset += file->f_pos;
1612         }
1613         retval = -EINVAL;
1614         if (offset >= 0 && offset <= inode->i_sb->s_maxbytes) {
1615                 if (offset != file->f_pos) {
1616                         file->f_pos = offset;
1617                         file->f_version = 0;
1618                 }
1619                 retval = offset;
1620         }
1621 exit:
1622         mutex_unlock(&inode->i_mutex);
1623         return retval;
1624 }
1625
1626 static int fuse_ioctl_copy_user(struct page **pages, struct iovec *iov,
1627                         unsigned int nr_segs, size_t bytes, bool to_user)
1628 {
1629         struct iov_iter ii;
1630         int page_idx = 0;
1631
1632         if (!bytes)
1633                 return 0;
1634
1635         iov_iter_init(&ii, iov, nr_segs, bytes, 0);
1636
1637         while (iov_iter_count(&ii)) {
1638                 struct page *page = pages[page_idx++];
1639                 size_t todo = min_t(size_t, PAGE_SIZE, iov_iter_count(&ii));
1640                 void *kaddr;
1641
1642                 kaddr = kmap(page);
1643
1644                 while (todo) {
1645                         char __user *uaddr = ii.iov->iov_base + ii.iov_offset;
1646                         size_t iov_len = ii.iov->iov_len - ii.iov_offset;
1647                         size_t copy = min(todo, iov_len);
1648                         size_t left;
1649
1650                         if (!to_user)
1651                                 left = copy_from_user(kaddr, uaddr, copy);
1652                         else
1653                                 left = copy_to_user(uaddr, kaddr, copy);
1654
1655                         if (unlikely(left))
1656                                 return -EFAULT;
1657
1658                         iov_iter_advance(&ii, copy);
1659                         todo -= copy;
1660                         kaddr += copy;
1661                 }
1662
1663                 kunmap(page);
1664         }
1665
1666         return 0;
1667 }
1668
1669 /*
1670  * CUSE servers compiled on 32bit broke on 64bit kernels because the
1671  * ABI was defined to be 'struct iovec' which is different on 32bit
1672  * and 64bit.  Fortunately we can determine which structure the server
1673  * used from the size of the reply.
1674  */
1675 static int fuse_copy_ioctl_iovec_old(struct iovec *dst, void *src,
1676                                      size_t transferred, unsigned count,
1677                                      bool is_compat)
1678 {
1679 #ifdef CONFIG_COMPAT
1680         if (count * sizeof(struct compat_iovec) == transferred) {
1681                 struct compat_iovec *ciov = src;
1682                 unsigned i;
1683
1684                 /*
1685                  * With this interface a 32bit server cannot support
1686                  * non-compat (i.e. ones coming from 64bit apps) ioctl
1687                  * requests
1688                  */
1689                 if (!is_compat)
1690                         return -EINVAL;
1691
1692                 for (i = 0; i < count; i++) {
1693                         dst[i].iov_base = compat_ptr(ciov[i].iov_base);
1694                         dst[i].iov_len = ciov[i].iov_len;
1695                 }
1696                 return 0;
1697         }
1698 #endif
1699
1700         if (count * sizeof(struct iovec) != transferred)
1701                 return -EIO;
1702
1703         memcpy(dst, src, transferred);
1704         return 0;
1705 }
1706
1707 /* Make sure iov_length() won't overflow */
1708 static int fuse_verify_ioctl_iov(struct iovec *iov, size_t count)
1709 {
1710         size_t n;
1711         u32 max = FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT;
1712
1713         for (n = 0; n < count; n++) {
1714                 if (iov->iov_len > (size_t) max)
1715                         return -ENOMEM;
1716                 max -= iov->iov_len;
1717         }
1718         return 0;
1719 }
1720
1721 static int fuse_copy_ioctl_iovec(struct fuse_conn *fc, struct iovec *dst,
1722                                  void *src, size_t transferred, unsigned count,
1723                                  bool is_compat)
1724 {
1725         unsigned i;
1726         struct fuse_ioctl_iovec *fiov = src;
1727
1728         if (fc->minor < 16) {
1729                 return fuse_copy_ioctl_iovec_old(dst, src, transferred,
1730                                                  count, is_compat);
1731         }
1732
1733         if (count * sizeof(struct fuse_ioctl_iovec) != transferred)
1734                 return -EIO;
1735
1736         for (i = 0; i < count; i++) {
1737                 /* Did the server supply an inappropriate value? */
1738                 if (fiov[i].base != (unsigned long) fiov[i].base ||
1739                     fiov[i].len != (unsigned long) fiov[i].len)
1740                         return -EIO;
1741
1742                 dst[i].iov_base = (void __user *) (unsigned long) fiov[i].base;
1743                 dst[i].iov_len = (size_t) fiov[i].len;
1744
1745 #ifdef CONFIG_COMPAT
1746                 if (is_compat &&
1747                     (ptr_to_compat(dst[i].iov_base) != fiov[i].base ||
1748                      (compat_size_t) dst[i].iov_len != fiov[i].len))
1749                         return -EIO;
1750 #endif
1751         }
1752
1753         return 0;
1754 }
1755
1756
1757 /*
1758  * For ioctls, there is no generic way to determine how much memory
1759  * needs to be read and/or written.  Furthermore, ioctls are allowed
1760  * to dereference the passed pointer, so the parameter requires deep
1761  * copying but FUSE has no idea whatsoever about what to copy in or
1762  * out.
1763  *
1764  * This is solved by allowing FUSE server to retry ioctl with
1765  * necessary in/out iovecs.  Let's assume the ioctl implementation
1766  * needs to read in the following structure.
1767  *
1768  * struct a {
1769  *      char    *buf;
1770  *      size_t  buflen;
1771  * }
1772  *
1773  * On the first callout to FUSE server, inarg->in_size and
1774  * inarg->out_size will be NULL; then, the server completes the ioctl
1775  * with FUSE_IOCTL_RETRY set in out->flags, out->in_iovs set to 1 and
1776  * the actual iov array to
1777  *
1778  * { { .iov_base = inarg.arg,   .iov_len = sizeof(struct a) } }
1779  *
1780  * which tells FUSE to copy in the requested area and retry the ioctl.
1781  * On the second round, the server has access to the structure and
1782  * from that it can tell what to look for next, so on the invocation,
1783  * it sets FUSE_IOCTL_RETRY, out->in_iovs to 2 and iov array to
1784  *
1785  * { { .iov_base = inarg.arg,   .iov_len = sizeof(struct a)     },
1786  *   { .iov_base = a.buf,       .iov_len = a.buflen             } }
1787  *
1788  * FUSE will copy both struct a and the pointed buffer from the
1789  * process doing the ioctl and retry ioctl with both struct a and the
1790  * buffer.
1791  *
1792  * This time, FUSE server has everything it needs and completes ioctl
1793  * without FUSE_IOCTL_RETRY which finishes the ioctl call.
1794  *
1795  * Copying data out works the same way.
1796  *
1797  * Note that if FUSE_IOCTL_UNRESTRICTED is clear, the kernel
1798  * automatically initializes in and out iovs by decoding @cmd with
1799  * _IOC_* macros and the server is not allowed to request RETRY.  This
1800  * limits ioctl data transfers to well-formed ioctls and is the forced
1801  * behavior for all FUSE servers.
1802  */
1803 long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
1804                    unsigned int flags)
1805 {
1806         struct fuse_file *ff = file->private_data;
1807         struct fuse_conn *fc = ff->fc;
1808         struct fuse_ioctl_in inarg = {
1809                 .fh = ff->fh,
1810                 .cmd = cmd,
1811                 .arg = arg,
1812                 .flags = flags
1813         };
1814         struct fuse_ioctl_out outarg;
1815         struct fuse_req *req = NULL;
1816         struct page **pages = NULL;
1817         struct iovec *iov_page = NULL;
1818         struct iovec *in_iov = NULL, *out_iov = NULL;
1819         unsigned int in_iovs = 0, out_iovs = 0, num_pages = 0, max_pages;
1820         size_t in_size, out_size, transferred;
1821         int err;
1822
1823 #if BITS_PER_LONG == 32
1824         inarg.flags |= FUSE_IOCTL_32BIT;
1825 #else
1826         if (flags & FUSE_IOCTL_COMPAT)
1827                 inarg.flags |= FUSE_IOCTL_32BIT;
1828 #endif
1829
1830         /* assume all the iovs returned by client always fits in a page */
1831         BUILD_BUG_ON(sizeof(struct fuse_ioctl_iovec) * FUSE_IOCTL_MAX_IOV > PAGE_SIZE);
1832
1833         err = -ENOMEM;
1834         pages = kzalloc(sizeof(pages[0]) * FUSE_MAX_PAGES_PER_REQ, GFP_KERNEL);
1835         iov_page = (struct iovec *) __get_free_page(GFP_KERNEL);
1836         if (!pages || !iov_page)
1837                 goto out;
1838
1839         /*
1840          * If restricted, initialize IO parameters as encoded in @cmd.
1841          * RETRY from server is not allowed.
1842          */
1843         if (!(flags & FUSE_IOCTL_UNRESTRICTED)) {
1844                 struct iovec *iov = iov_page;
1845
1846                 iov->iov_base = (void __user *)arg;
1847                 iov->iov_len = _IOC_SIZE(cmd);
1848
1849                 if (_IOC_DIR(cmd) & _IOC_WRITE) {
1850                         in_iov = iov;
1851                         in_iovs = 1;
1852                 }
1853
1854                 if (_IOC_DIR(cmd) & _IOC_READ) {
1855                         out_iov = iov;
1856                         out_iovs = 1;
1857                 }
1858         }
1859
1860  retry:
1861         inarg.in_size = in_size = iov_length(in_iov, in_iovs);
1862         inarg.out_size = out_size = iov_length(out_iov, out_iovs);
1863
1864         /*
1865          * Out data can be used either for actual out data or iovs,
1866          * make sure there always is at least one page.
1867          */
1868         out_size = max_t(size_t, out_size, PAGE_SIZE);
1869         max_pages = DIV_ROUND_UP(max(in_size, out_size), PAGE_SIZE);
1870
1871         /* make sure there are enough buffer pages and init request with them */
1872         err = -ENOMEM;
1873         if (max_pages > FUSE_MAX_PAGES_PER_REQ)
1874                 goto out;
1875         while (num_pages < max_pages) {
1876                 pages[num_pages] = alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
1877                 if (!pages[num_pages])
1878                         goto out;
1879                 num_pages++;
1880         }
1881
1882         req = fuse_get_req(fc);
1883         if (IS_ERR(req)) {
1884                 err = PTR_ERR(req);
1885                 req = NULL;
1886                 goto out;
1887         }
1888         memcpy(req->pages, pages, sizeof(req->pages[0]) * num_pages);
1889         req->num_pages = num_pages;
1890
1891         /* okay, let's send it to the client */
1892         req->in.h.opcode = FUSE_IOCTL;
1893         req->in.h.nodeid = ff->nodeid;
1894         req->in.numargs = 1;
1895         req->in.args[0].size = sizeof(inarg);
1896         req->in.args[0].value = &inarg;
1897         if (in_size) {
1898                 req->in.numargs++;
1899                 req->in.args[1].size = in_size;
1900                 req->in.argpages = 1;
1901
1902                 err = fuse_ioctl_copy_user(pages, in_iov, in_iovs, in_size,
1903                                            false);
1904                 if (err)
1905                         goto out;
1906         }
1907
1908         req->out.numargs = 2;
1909         req->out.args[0].size = sizeof(outarg);
1910         req->out.args[0].value = &outarg;
1911         req->out.args[1].size = out_size;
1912         req->out.argpages = 1;
1913         req->out.argvar = 1;
1914
1915         fuse_request_send(fc, req);
1916         err = req->out.h.error;
1917         transferred = req->out.args[1].size;
1918         fuse_put_request(fc, req);
1919         req = NULL;
1920         if (err)
1921                 goto out;
1922
1923         /* did it ask for retry? */
1924         if (outarg.flags & FUSE_IOCTL_RETRY) {
1925                 void *vaddr;
1926
1927                 /* no retry if in restricted mode */
1928                 err = -EIO;
1929                 if (!(flags & FUSE_IOCTL_UNRESTRICTED))
1930                         goto out;
1931
1932                 in_iovs = outarg.in_iovs;
1933                 out_iovs = outarg.out_iovs;
1934
1935                 /*
1936                  * Make sure things are in boundary, separate checks
1937                  * are to protect against overflow.
1938                  */
1939                 err = -ENOMEM;
1940                 if (in_iovs > FUSE_IOCTL_MAX_IOV ||
1941                     out_iovs > FUSE_IOCTL_MAX_IOV ||
1942                     in_iovs + out_iovs > FUSE_IOCTL_MAX_IOV)
1943                         goto out;
1944
1945                 vaddr = kmap_atomic(pages[0], KM_USER0);
1946                 err = fuse_copy_ioctl_iovec(fc, iov_page, vaddr,
1947                                             transferred, in_iovs + out_iovs,
1948                                             (flags & FUSE_IOCTL_COMPAT) != 0);
1949                 kunmap_atomic(vaddr, KM_USER0);
1950                 if (err)
1951                         goto out;
1952
1953                 in_iov = iov_page;
1954                 out_iov = in_iov + in_iovs;
1955
1956                 err = fuse_verify_ioctl_iov(in_iov, in_iovs);
1957                 if (err)
1958                         goto out;
1959
1960                 err = fuse_verify_ioctl_iov(out_iov, out_iovs);
1961                 if (err)
1962                         goto out;
1963
1964                 goto retry;
1965         }
1966
1967         err = -EIO;
1968         if (transferred > inarg.out_size)
1969                 goto out;
1970
1971         err = fuse_ioctl_copy_user(pages, out_iov, out_iovs, transferred, true);
1972  out:
1973         if (req)
1974                 fuse_put_request(fc, req);
1975         free_page((unsigned long) iov_page);
1976         while (num_pages)
1977                 __free_page(pages[--num_pages]);
1978         kfree(pages);
1979
1980         return err ? err : outarg.result;
1981 }
1982 EXPORT_SYMBOL_GPL(fuse_do_ioctl);
1983
1984 static long fuse_file_ioctl_common(struct file *file, unsigned int cmd,
1985                                    unsigned long arg, unsigned int flags)
1986 {
1987         struct inode *inode = file->f_dentry->d_inode;
1988         struct fuse_conn *fc = get_fuse_conn(inode);
1989
1990         if (!fuse_allow_task(fc, current))
1991                 return -EACCES;
1992
1993         if (is_bad_inode(inode))
1994                 return -EIO;
1995
1996         return fuse_do_ioctl(file, cmd, arg, flags);
1997 }
1998
1999 static long fuse_file_ioctl(struct file *file, unsigned int cmd,
2000                             unsigned long arg)
2001 {
2002         return fuse_file_ioctl_common(file, cmd, arg, 0);
2003 }
2004
2005 static long fuse_file_compat_ioctl(struct file *file, unsigned int cmd,
2006                                    unsigned long arg)
2007 {
2008         return fuse_file_ioctl_common(file, cmd, arg, FUSE_IOCTL_COMPAT);
2009 }
2010
2011 /*
2012  * All files which have been polled are linked to RB tree
2013  * fuse_conn->polled_files which is indexed by kh.  Walk the tree and
2014  * find the matching one.
2015  */
2016 static struct rb_node **fuse_find_polled_node(struct fuse_conn *fc, u64 kh,
2017                                               struct rb_node **parent_out)
2018 {
2019         struct rb_node **link = &fc->polled_files.rb_node;
2020         struct rb_node *last = NULL;
2021
2022         while (*link) {
2023                 struct fuse_file *ff;
2024
2025                 last = *link;
2026                 ff = rb_entry(last, struct fuse_file, polled_node);
2027
2028                 if (kh < ff->kh)
2029                         link = &last->rb_left;
2030                 else if (kh > ff->kh)
2031                         link = &last->rb_right;
2032                 else
2033                         return link;
2034         }
2035
2036         if (parent_out)
2037                 *parent_out = last;
2038         return link;
2039 }
2040
2041 /*
2042  * The file is about to be polled.  Make sure it's on the polled_files
2043  * RB tree.  Note that files once added to the polled_files tree are
2044  * not removed before the file is released.  This is because a file
2045  * polled once is likely to be polled again.
2046  */
2047 static void fuse_register_polled_file(struct fuse_conn *fc,
2048                                       struct fuse_file *ff)
2049 {
2050         spin_lock(&fc->lock);
2051         if (RB_EMPTY_NODE(&ff->polled_node)) {
2052                 struct rb_node **link, *parent;
2053
2054                 link = fuse_find_polled_node(fc, ff->kh, &parent);
2055                 BUG_ON(*link);
2056                 rb_link_node(&ff->polled_node, parent, link);
2057                 rb_insert_color(&ff->polled_node, &fc->polled_files);
2058         }
2059         spin_unlock(&fc->lock);
2060 }
2061
2062 unsigned fuse_file_poll(struct file *file, poll_table *wait)
2063 {
2064         struct fuse_file *ff = file->private_data;
2065         struct fuse_conn *fc = ff->fc;
2066         struct fuse_poll_in inarg = { .fh = ff->fh, .kh = ff->kh };
2067         struct fuse_poll_out outarg;
2068         struct fuse_req *req;
2069         int err;
2070
2071         if (fc->no_poll)
2072                 return DEFAULT_POLLMASK;
2073
2074         poll_wait(file, &ff->poll_wait, wait);
2075
2076         /*
2077          * Ask for notification iff there's someone waiting for it.
2078          * The client may ignore the flag and always notify.
2079          */
2080         if (waitqueue_active(&ff->poll_wait)) {
2081                 inarg.flags |= FUSE_POLL_SCHEDULE_NOTIFY;
2082                 fuse_register_polled_file(fc, ff);
2083         }
2084
2085         req = fuse_get_req(fc);
2086         if (IS_ERR(req))
2087                 return POLLERR;
2088
2089         req->in.h.opcode = FUSE_POLL;
2090         req->in.h.nodeid = ff->nodeid;
2091         req->in.numargs = 1;
2092         req->in.args[0].size = sizeof(inarg);
2093         req->in.args[0].value = &inarg;
2094         req->out.numargs = 1;
2095         req->out.args[0].size = sizeof(outarg);
2096         req->out.args[0].value = &outarg;
2097         fuse_request_send(fc, req);
2098         err = req->out.h.error;
2099         fuse_put_request(fc, req);
2100
2101         if (!err)
2102                 return outarg.revents;
2103         if (err == -ENOSYS) {
2104                 fc->no_poll = 1;
2105                 return DEFAULT_POLLMASK;
2106         }
2107         return POLLERR;
2108 }
2109 EXPORT_SYMBOL_GPL(fuse_file_poll);
2110
2111 /*
2112  * This is called from fuse_handle_notify() on FUSE_NOTIFY_POLL and
2113  * wakes up the poll waiters.
2114  */
2115 int fuse_notify_poll_wakeup(struct fuse_conn *fc,
2116                             struct fuse_notify_poll_wakeup_out *outarg)
2117 {
2118         u64 kh = outarg->kh;
2119         struct rb_node **link;
2120
2121         spin_lock(&fc->lock);
2122
2123         link = fuse_find_polled_node(fc, kh, NULL);
2124         if (*link) {
2125                 struct fuse_file *ff;
2126
2127                 ff = rb_entry(*link, struct fuse_file, polled_node);
2128                 wake_up_interruptible_sync(&ff->poll_wait);
2129         }
2130
2131         spin_unlock(&fc->lock);
2132         return 0;
2133 }
2134
2135 static const struct file_operations fuse_file_operations = {
2136         .llseek         = fuse_file_llseek,
2137         .read           = do_sync_read,
2138         .aio_read       = fuse_file_aio_read,
2139         .write          = do_sync_write,
2140         .aio_write      = fuse_file_aio_write,
2141         .mmap           = fuse_file_mmap,
2142         .open           = fuse_open,
2143         .flush          = fuse_flush,
2144         .release        = fuse_release,
2145         .fsync          = fuse_fsync,
2146         .lock           = fuse_file_lock,
2147         .flock          = fuse_file_flock,
2148         .splice_read    = generic_file_splice_read,
2149         .unlocked_ioctl = fuse_file_ioctl,
2150         .compat_ioctl   = fuse_file_compat_ioctl,
2151         .poll           = fuse_file_poll,
2152 };
2153
2154 static const struct file_operations fuse_direct_io_file_operations = {
2155         .llseek         = fuse_file_llseek,
2156         .read           = fuse_direct_read,
2157         .write          = fuse_direct_write,
2158         .mmap           = fuse_direct_mmap,
2159         .open           = fuse_open,
2160         .flush          = fuse_flush,
2161         .release        = fuse_release,
2162         .fsync          = fuse_fsync,
2163         .lock           = fuse_file_lock,
2164         .flock          = fuse_file_flock,
2165         .unlocked_ioctl = fuse_file_ioctl,
2166         .compat_ioctl   = fuse_file_compat_ioctl,
2167         .poll           = fuse_file_poll,
2168         /* no splice_read */
2169 };
2170
2171 static const struct address_space_operations fuse_file_aops  = {
2172         .readpage       = fuse_readpage,
2173         .writepage      = fuse_writepage,
2174         .launder_page   = fuse_launder_page,
2175         .write_begin    = fuse_write_begin,
2176         .write_end      = fuse_write_end,
2177         .readpages      = fuse_readpages,
2178         .set_page_dirty = __set_page_dirty_nobuffers,
2179         .bmap           = fuse_bmap,
2180 };
2181
2182 void fuse_init_file_inode(struct inode *inode)
2183 {
2184         inode->i_fop = &fuse_file_operations;
2185         inode->i_data.a_ops = &fuse_file_aops;
2186 }