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Committer: Michael Beasley <mike@snafu.setup>
[mikesnafu-overlay.git] / fs / fuse / file.c
blob676b0bc8a86dba3e3c048a1a35320d3931a65f20
1 /*
2 FUSE: Filesystem in Userspace
3 Copyright (C) 2001-2006 Miklos Szeredi <miklos@szeredi.hu>
4
5 This program can be distributed under the terms of the GNU GPL.
6 See the file COPYING.
7 */
8
9 #include "fuse_i.h"
10
11 #include <linux/pagemap.h>
12 #include <linux/slab.h>
13 #include <linux/kernel.h>
14 #include <linux/sched.h>
15
16 static const struct file_operations fuse_direct_io_file_operations;
17
18 static int fuse_send_open(struct inode *inode, struct file *file, int isdir,
19 struct fuse_open_out *outargp)
20 {
21 struct fuse_conn *fc = get_fuse_conn(inode);
22 struct fuse_open_in inarg;
23 struct fuse_req *req;
24 int err;
25
26 req = fuse_get_req(fc);
27 if (IS_ERR(req))
28 return PTR_ERR(req);
29
30 memset(&inarg, 0, sizeof(inarg));
31 inarg.flags = file->f_flags & ~(O_CREAT | O_EXCL | O_NOCTTY);
32 if (!fc->atomic_o_trunc)
33 inarg.flags &= ~O_TRUNC;
34 req->in.h.opcode = isdir ? FUSE_OPENDIR : FUSE_OPEN;
35 req->in.h.nodeid = get_node_id(inode);
36 req->in.numargs = 1;
37 req->in.args[0].size = sizeof(inarg);
38 req->in.args[0].value = &inarg;
39 req->out.numargs = 1;
40 req->out.args[0].size = sizeof(*outargp);
41 req->out.args[0].value = outargp;
42 request_send(fc, req);
43 err = req->out.h.error;
44 fuse_put_request(fc, req);
45
46 return err;
47 }
48
49 struct fuse_file *fuse_file_alloc(void)
50 {
51 struct fuse_file *ff;
52 ff = kmalloc(sizeof(struct fuse_file), GFP_KERNEL);
53 if (ff) {
54 ff->reserved_req = fuse_request_alloc();
55 if (!ff->reserved_req) {
56 kfree(ff);
57 ff = NULL;
58 } else {
59 INIT_LIST_HEAD(&ff->write_entry);
60 atomic_set(&ff->count, 0);
61 }
62 }
63 return ff;
64 }
65
66 void fuse_file_free(struct fuse_file *ff)
67 {
68 fuse_request_free(ff->reserved_req);
69 kfree(ff);
70 }
71
72 static struct fuse_file *fuse_file_get(struct fuse_file *ff)
73 {
74 atomic_inc(&ff->count);
75 return ff;
76 }
77
78 static void fuse_release_end(struct fuse_conn *fc, struct fuse_req *req)
79 {
80 dput(req->misc.release.dentry);
81 mntput(req->misc.release.vfsmount);
82 fuse_put_request(fc, req);
83 }
84
85 static void fuse_file_put(struct fuse_file *ff)
86 {
87 if (atomic_dec_and_test(&ff->count)) {
88 struct fuse_req *req = ff->reserved_req;
89 struct inode *inode = req->misc.release.dentry->d_inode;
90 struct fuse_conn *fc = get_fuse_conn(inode);
91 req->end = fuse_release_end;
92 request_send_background(fc, req);
93 kfree(ff);
94 }
95 }
96
97 void fuse_finish_open(struct inode *inode, struct file *file,
98 struct fuse_file *ff, struct fuse_open_out *outarg)
99 {
100 if (outarg->open_flags & FOPEN_DIRECT_IO)
101 file->f_op = &fuse_direct_io_file_operations;
102 if (!(outarg->open_flags & FOPEN_KEEP_CACHE))
103 invalidate_inode_pages2(inode->i_mapping);
104 ff->fh = outarg->fh;
105 file->private_data = fuse_file_get(ff);
106 }
107
108 int fuse_open_common(struct inode *inode, struct file *file, int isdir)
109 {
110 struct fuse_open_out outarg;
111 struct fuse_file *ff;
112 int err;
113
114 /* VFS checks this, but only _after_ ->open() */
115 if (file->f_flags & O_DIRECT)
116 return -EINVAL;
117
118 err = generic_file_open(inode, file);
119 if (err)
120 return err;
121
122 ff = fuse_file_alloc();
123 if (!ff)
124 return -ENOMEM;
125
126 err = fuse_send_open(inode, file, isdir, &outarg);
127 if (err)
128 fuse_file_free(ff);
129 else {
130 if (isdir)
131 outarg.open_flags &= ~FOPEN_DIRECT_IO;
132 fuse_finish_open(inode, file, ff, &outarg);
133 }
134
135 return err;
136 }
137
138 void fuse_release_fill(struct fuse_file *ff, u64 nodeid, int flags, int opcode)
139 {
140 struct fuse_req *req = ff->reserved_req;
141 struct fuse_release_in *inarg = &req->misc.release.in;
142
143 inarg->fh = ff->fh;
144 inarg->flags = flags;
145 req->in.h.opcode = opcode;
146 req->in.h.nodeid = nodeid;
147 req->in.numargs = 1;
148 req->in.args[0].size = sizeof(struct fuse_release_in);
149 req->in.args[0].value = inarg;
150 }
151
152 int fuse_release_common(struct inode *inode, struct file *file, int isdir)
153 {
154 struct fuse_file *ff = file->private_data;
155 if (ff) {
156 struct fuse_conn *fc = get_fuse_conn(inode);
157 struct fuse_req *req = ff->reserved_req;
158
159 fuse_release_fill(ff, get_node_id(inode), file->f_flags,
160 isdir ? FUSE_RELEASEDIR : FUSE_RELEASE);
161
162 /* Hold vfsmount and dentry until release is finished */
163 req->misc.release.vfsmount = mntget(file->f_path.mnt);
164 req->misc.release.dentry = dget(file->f_path.dentry);
165
166 spin_lock(&fc->lock);
167 list_del(&ff->write_entry);
168 spin_unlock(&fc->lock);
169 /*
170 * Normally this will send the RELEASE request,
171 * however if some asynchronous READ or WRITE requests
172 * are outstanding, the sending will be delayed
173 */
174 fuse_file_put(ff);
175 }
176
177 /* Return value is ignored by VFS */
178 return 0;
179 }
180
181 static int fuse_open(struct inode *inode, struct file *file)
182 {
183 return fuse_open_common(inode, file, 0);
184 }
185
186 static int fuse_release(struct inode *inode, struct file *file)
187 {
188 return fuse_release_common(inode, file, 0);
189 }
190
191 /*
192 * Scramble the ID space with XTEA, so that the value of the files_struct
193 * pointer is not exposed to userspace.
194 */
195 u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id)
196 {
197 u32 *k = fc->scramble_key;
198 u64 v = (unsigned long) id;
199 u32 v0 = v;
200 u32 v1 = v >> 32;
201 u32 sum = 0;
202 int i;
203
204 for (i = 0; i < 32; i++) {
205 v0 += ((v1 << 4 ^ v1 >> 5) + v1) ^ (sum + k[sum & 3]);
206 sum += 0x9E3779B9;
207 v1 += ((v0 << 4 ^ v0 >> 5) + v0) ^ (sum + k[sum>>11 & 3]);
208 }
209
210 return (u64) v0 + ((u64) v1 << 32);
211 }
212
213 static int fuse_flush(struct file *file, fl_owner_t id)
214 {
215 struct inode *inode = file->f_path.dentry->d_inode;
216 struct fuse_conn *fc = get_fuse_conn(inode);
217 struct fuse_file *ff = file->private_data;
218 struct fuse_req *req;
219 struct fuse_flush_in inarg;
220 int err;
221
222 if (is_bad_inode(inode))
223 return -EIO;
224
225 if (fc->no_flush)
226 return 0;
227
228 req = fuse_get_req_nofail(fc, file);
229 memset(&inarg, 0, sizeof(inarg));
230 inarg.fh = ff->fh;
231 inarg.lock_owner = fuse_lock_owner_id(fc, id);
232 req->in.h.opcode = FUSE_FLUSH;
233 req->in.h.nodeid = get_node_id(inode);
234 req->in.numargs = 1;
235 req->in.args[0].size = sizeof(inarg);
236 req->in.args[0].value = &inarg;
237 req->force = 1;
238 request_send(fc, req);
239 err = req->out.h.error;
240 fuse_put_request(fc, req);
241 if (err == -ENOSYS) {
242 fc->no_flush = 1;
243 err = 0;
244 }
245 return err;
246 }
247
248 int fuse_fsync_common(struct file *file, struct dentry *de, int datasync,
249 int isdir)
250 {
251 struct inode *inode = de->d_inode;
252 struct fuse_conn *fc = get_fuse_conn(inode);
253 struct fuse_file *ff = file->private_data;
254 struct fuse_req *req;
255 struct fuse_fsync_in inarg;
256 int err;
257
258 if (is_bad_inode(inode))
259 return -EIO;
260
261 if ((!isdir && fc->no_fsync) || (isdir && fc->no_fsyncdir))
262 return 0;
263
264 req = fuse_get_req(fc);
265 if (IS_ERR(req))
266 return PTR_ERR(req);
267
268 memset(&inarg, 0, sizeof(inarg));
269 inarg.fh = ff->fh;
270 inarg.fsync_flags = datasync ? 1 : 0;
271 req->in.h.opcode = isdir ? FUSE_FSYNCDIR : FUSE_FSYNC;
272 req->in.h.nodeid = get_node_id(inode);
273 req->in.numargs = 1;
274 req->in.args[0].size = sizeof(inarg);
275 req->in.args[0].value = &inarg;
276 request_send(fc, req);
277 err = req->out.h.error;
278 fuse_put_request(fc, req);
279 if (err == -ENOSYS) {
280 if (isdir)
281 fc->no_fsyncdir = 1;
282 else
283 fc->no_fsync = 1;
284 err = 0;
285 }
286 return err;
287 }
288
289 static int fuse_fsync(struct file *file, struct dentry *de, int datasync)
290 {
291 return fuse_fsync_common(file, de, datasync, 0);
292 }
293
294 void fuse_read_fill(struct fuse_req *req, struct file *file,
295 struct inode *inode, loff_t pos, size_t count, int opcode)
296 {
297 struct fuse_read_in *inarg = &req->misc.read_in;
298 struct fuse_file *ff = file->private_data;
299
300 inarg->fh = ff->fh;
301 inarg->offset = pos;
302 inarg->size = count;
303 inarg->flags = file->f_flags;
304 req->in.h.opcode = opcode;
305 req->in.h.nodeid = get_node_id(inode);
306 req->in.numargs = 1;
307 req->in.args[0].size = sizeof(struct fuse_read_in);
308 req->in.args[0].value = inarg;
309 req->out.argpages = 1;
310 req->out.argvar = 1;
311 req->out.numargs = 1;
312 req->out.args[0].size = count;
313 }
314
315 static size_t fuse_send_read(struct fuse_req *req, struct file *file,
316 struct inode *inode, loff_t pos, size_t count,
317 fl_owner_t owner)
318 {
319 struct fuse_conn *fc = get_fuse_conn(inode);
320
321 fuse_read_fill(req, file, inode, pos, count, FUSE_READ);
322 if (owner != NULL) {
323 struct fuse_read_in *inarg = &req->misc.read_in;
324
325 inarg->read_flags |= FUSE_READ_LOCKOWNER;
326 inarg->lock_owner = fuse_lock_owner_id(fc, owner);
327 }
328 request_send(fc, req);
329 return req->out.args[0].size;
330 }
331
332 static int fuse_readpage(struct file *file, struct page *page)
333 {
334 struct inode *inode = page->mapping->host;
335 struct fuse_conn *fc = get_fuse_conn(inode);
336 struct fuse_req *req;
337 int err;
338
339 err = -EIO;
340 if (is_bad_inode(inode))
341 goto out;
342
343 req = fuse_get_req(fc);
344 err = PTR_ERR(req);
345 if (IS_ERR(req))
346 goto out;
347
348 req->out.page_zeroing = 1;
349 req->num_pages = 1;
350 req->pages[0] = page;
351 fuse_send_read(req, file, inode, page_offset(page), PAGE_CACHE_SIZE,
352 NULL);
353 err = req->out.h.error;
354 fuse_put_request(fc, req);
355 if (!err)
356 SetPageUptodate(page);
357 fuse_invalidate_attr(inode); /* atime changed */
358 out:
359 unlock_page(page);
360 return err;
361 }
362
363 static void fuse_readpages_end(struct fuse_conn *fc, struct fuse_req *req)
364 {
365 int i;
366
367 fuse_invalidate_attr(req->pages[0]->mapping->host); /* atime changed */
368
369 for (i = 0; i < req->num_pages; i++) {
370 struct page *page = req->pages[i];
371 if (!req->out.h.error)
372 SetPageUptodate(page);
373 else
374 SetPageError(page);
375 unlock_page(page);
376 }
377 if (req->ff)
378 fuse_file_put(req->ff);
379 fuse_put_request(fc, req);
380 }
381
382 static void fuse_send_readpages(struct fuse_req *req, struct file *file,
383 struct inode *inode)
384 {
385 struct fuse_conn *fc = get_fuse_conn(inode);
386 loff_t pos = page_offset(req->pages[0]);
387 size_t count = req->num_pages << PAGE_CACHE_SHIFT;
388 req->out.page_zeroing = 1;
389 fuse_read_fill(req, file, inode, pos, count, FUSE_READ);
390 if (fc->async_read) {
391 struct fuse_file *ff = file->private_data;
392 req->ff = fuse_file_get(ff);
393 req->end = fuse_readpages_end;
394 request_send_background(fc, req);
395 } else {
396 request_send(fc, req);
397 fuse_readpages_end(fc, req);
398 }
399 }
400
401 struct fuse_fill_data {
402 struct fuse_req *req;
403 struct file *file;
404 struct inode *inode;
405 };
406
407 static int fuse_readpages_fill(void *_data, struct page *page)
408 {
409 struct fuse_fill_data *data = _data;
410 struct fuse_req *req = data->req;
411 struct inode *inode = data->inode;
412 struct fuse_conn *fc = get_fuse_conn(inode);
413
414 if (req->num_pages &&
415 (req->num_pages == FUSE_MAX_PAGES_PER_REQ ||
416 (req->num_pages + 1) * PAGE_CACHE_SIZE > fc->max_read ||
417 req->pages[req->num_pages - 1]->index + 1 != page->index)) {
418 fuse_send_readpages(req, data->file, inode);
419 data->req = req = fuse_get_req(fc);
420 if (IS_ERR(req)) {
421 unlock_page(page);
422 return PTR_ERR(req);
423 }
424 }
425 req->pages[req->num_pages] = page;
426 req->num_pages ++;
427 return 0;
428 }
429
430 static int fuse_readpages(struct file *file, struct address_space *mapping,
431 struct list_head *pages, unsigned nr_pages)
432 {
433 struct inode *inode = mapping->host;
434 struct fuse_conn *fc = get_fuse_conn(inode);
435 struct fuse_fill_data data;
436 int err;
437
438 err = -EIO;
439 if (is_bad_inode(inode))
440 goto out;
441
442 data.file = file;
443 data.inode = inode;
444 data.req = fuse_get_req(fc);
445 err = PTR_ERR(data.req);
446 if (IS_ERR(data.req))
447 goto out;
448
449 err = read_cache_pages(mapping, pages, fuse_readpages_fill, &data);
450 if (!err) {
451 if (data.req->num_pages)
452 fuse_send_readpages(data.req, file, inode);
453 else
454 fuse_put_request(fc, data.req);
455 }
456 out:
457 return err;
458 }
459
460 static ssize_t fuse_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
461 unsigned long nr_segs, loff_t pos)
462 {
463 struct inode *inode = iocb->ki_filp->f_mapping->host;
464
465 if (pos + iov_length(iov, nr_segs) > i_size_read(inode)) {
466 int err;
467 /*
468 * If trying to read past EOF, make sure the i_size
469 * attribute is up-to-date.
470 */
471 err = fuse_update_attributes(inode, NULL, iocb->ki_filp, NULL);
472 if (err)
473 return err;
474 }
475
476 return generic_file_aio_read(iocb, iov, nr_segs, pos);
477 }
478
479 static void fuse_write_fill(struct fuse_req *req, struct file *file,
480 struct inode *inode, loff_t pos, size_t count,
481 int writepage)
482 {
483 struct fuse_conn *fc = get_fuse_conn(inode);
484 struct fuse_file *ff = file->private_data;
485 struct fuse_write_in *inarg = &req->misc.write.in;
486 struct fuse_write_out *outarg = &req->misc.write.out;
487
488 memset(inarg, 0, sizeof(struct fuse_write_in));
489 inarg->fh = ff->fh;
490 inarg->offset = pos;
491 inarg->size = count;
492 inarg->write_flags = writepage ? FUSE_WRITE_CACHE : 0;
493 inarg->flags = file->f_flags;
494 req->in.h.opcode = FUSE_WRITE;
495 req->in.h.nodeid = get_node_id(inode);
496 req->in.argpages = 1;
497 req->in.numargs = 2;
498 if (fc->minor < 9)
499 req->in.args[0].size = FUSE_COMPAT_WRITE_IN_SIZE;
500 else
501 req->in.args[0].size = sizeof(struct fuse_write_in);
502 req->in.args[0].value = inarg;
503 req->in.args[1].size = count;
504 req->out.numargs = 1;
505 req->out.args[0].size = sizeof(struct fuse_write_out);
506 req->out.args[0].value = outarg;
507 }
508
509 static size_t fuse_send_write(struct fuse_req *req, struct file *file,
510 struct inode *inode, loff_t pos, size_t count,
511 fl_owner_t owner)
512 {
513 struct fuse_conn *fc = get_fuse_conn(inode);
514 fuse_write_fill(req, file, inode, pos, count, 0);
515 if (owner != NULL) {
516 struct fuse_write_in *inarg = &req->misc.write.in;
517 inarg->write_flags |= FUSE_WRITE_LOCKOWNER;
518 inarg->lock_owner = fuse_lock_owner_id(fc, owner);
519 }
520 request_send(fc, req);
521 return req->misc.write.out.size;
522 }
523
524 static int fuse_write_begin(struct file *file, struct address_space *mapping,
525 loff_t pos, unsigned len, unsigned flags,
526 struct page **pagep, void **fsdata)
527 {
528 pgoff_t index = pos >> PAGE_CACHE_SHIFT;
529
530 *pagep = __grab_cache_page(mapping, index);
531 if (!*pagep)
532 return -ENOMEM;
533 return 0;
534 }
535
536 static int fuse_buffered_write(struct file *file, struct inode *inode,
537 loff_t pos, unsigned count, struct page *page)
538 {
539 int err;
540 size_t nres;
541 struct fuse_conn *fc = get_fuse_conn(inode);
542 struct fuse_inode *fi = get_fuse_inode(inode);
543 unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
544 struct fuse_req *req;
545
546 if (is_bad_inode(inode))
547 return -EIO;
548
549 req = fuse_get_req(fc);
550 if (IS_ERR(req))
551 return PTR_ERR(req);
552
553 req->num_pages = 1;
554 req->pages[0] = page;
555 req->page_offset = offset;
556 nres = fuse_send_write(req, file, inode, pos, count, NULL);
557 err = req->out.h.error;
558 fuse_put_request(fc, req);
559 if (!err && !nres)
560 err = -EIO;
561 if (!err) {
562 pos += nres;
563 spin_lock(&fc->lock);
564 fi->attr_version = ++fc->attr_version;
565 if (pos > inode->i_size)
566 i_size_write(inode, pos);
567 spin_unlock(&fc->lock);
568
569 if (count == PAGE_CACHE_SIZE)
570 SetPageUptodate(page);
571 }
572 fuse_invalidate_attr(inode);
573 return err ? err : nres;
574 }
575
576 static int fuse_write_end(struct file *file, struct address_space *mapping,
577 loff_t pos, unsigned len, unsigned copied,
578 struct page *page, void *fsdata)
579 {
580 struct inode *inode = mapping->host;
581 int res = 0;
582
583 if (copied)
584 res = fuse_buffered_write(file, inode, pos, copied, page);
585
586 unlock_page(page);
587 page_cache_release(page);
588 return res;
589 }
590
591 static void fuse_release_user_pages(struct fuse_req *req, int write)
592 {
593 unsigned i;
594
595 for (i = 0; i < req->num_pages; i++) {
596 struct page *page = req->pages[i];
597 if (write)
598 set_page_dirty_lock(page);
599 put_page(page);
600 }
601 }
602
603 static int fuse_get_user_pages(struct fuse_req *req, const char __user *buf,
604 unsigned nbytes, int write)
605 {
606 unsigned long user_addr = (unsigned long) buf;
607 unsigned offset = user_addr & ~PAGE_MASK;
608 int npages;
609
610 /* This doesn't work with nfsd */
611 if (!current->mm)
612 return -EPERM;
613
614 nbytes = min(nbytes, (unsigned) FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT);
615 npages = (nbytes + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
616 npages = min(max(npages, 1), FUSE_MAX_PAGES_PER_REQ);
617 down_read(&current->mm->mmap_sem);
618 npages = get_user_pages(current, current->mm, user_addr, npages, write,
619 0, req->pages, NULL);
620 up_read(&current->mm->mmap_sem);
621 if (npages < 0)
622 return npages;
623
624 req->num_pages = npages;
625 req->page_offset = offset;
626 return 0;
627 }
628
629 static ssize_t fuse_direct_io(struct file *file, const char __user *buf,
630 size_t count, loff_t *ppos, int write)
631 {
632 struct inode *inode = file->f_path.dentry->d_inode;
633 struct fuse_conn *fc = get_fuse_conn(inode);
634 size_t nmax = write ? fc->max_write : fc->max_read;
635 loff_t pos = *ppos;
636 ssize_t res = 0;
637 struct fuse_req *req;
638
639 if (is_bad_inode(inode))
640 return -EIO;
641
642 req = fuse_get_req(fc);
643 if (IS_ERR(req))
644 return PTR_ERR(req);
645
646 while (count) {
647 size_t nres;
648 size_t nbytes = min(count, nmax);
649 int err = fuse_get_user_pages(req, buf, nbytes, !write);
650 if (err) {
651 res = err;
652 break;
653 }
654 nbytes = (req->num_pages << PAGE_SHIFT) - req->page_offset;
655 nbytes = min(count, nbytes);
656 if (write)
657 nres = fuse_send_write(req, file, inode, pos, nbytes,
658 current->files);
659 else
660 nres = fuse_send_read(req, file, inode, pos, nbytes,
661 current->files);
662 fuse_release_user_pages(req, !write);
663 if (req->out.h.error) {
664 if (!res)
665 res = req->out.h.error;
666 break;
667 } else if (nres > nbytes) {
668 res = -EIO;
669 break;
670 }
671 count -= nres;
672 res += nres;
673 pos += nres;
674 buf += nres;
675 if (nres != nbytes)
676 break;
677 if (count) {
678 fuse_put_request(fc, req);
679 req = fuse_get_req(fc);
680 if (IS_ERR(req))
681 break;
682 }
683 }
684 fuse_put_request(fc, req);
685 if (res > 0) {
686 if (write) {
687 spin_lock(&fc->lock);
688 if (pos > inode->i_size)
689 i_size_write(inode, pos);
690 spin_unlock(&fc->lock);
691 }
692 *ppos = pos;
693 }
694 fuse_invalidate_attr(inode);
695
696 return res;
697 }
698
699 static ssize_t fuse_direct_read(struct file *file, char __user *buf,
700 size_t count, loff_t *ppos)
701 {
702 return fuse_direct_io(file, buf, count, ppos, 0);
703 }
704
705 static ssize_t fuse_direct_write(struct file *file, const char __user *buf,
706 size_t count, loff_t *ppos)
707 {
708 struct inode *inode = file->f_path.dentry->d_inode;
709 ssize_t res;
710 /* Don't allow parallel writes to the same file */
711 mutex_lock(&inode->i_mutex);
712 res = generic_write_checks(file, ppos, &count, 0);
713 if (!res)
714 res = fuse_direct_io(file, buf, count, ppos, 1);
715 mutex_unlock(&inode->i_mutex);
716 return res;
717 }
718
719 static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma)
720 {
721 if ((vma->vm_flags & VM_SHARED)) {
722 if ((vma->vm_flags & VM_WRITE))
723 return -ENODEV;
724 else
725 vma->vm_flags &= ~VM_MAYWRITE;
726 }
727 return generic_file_mmap(file, vma);
728 }
729
730 static int fuse_set_page_dirty(struct page *page)
731 {
732 printk("fuse_set_page_dirty: should not happen\n");
733 dump_stack();
734 return 0;
735 }
736
737 static int convert_fuse_file_lock(const struct fuse_file_lock *ffl,
738 struct file_lock *fl)
739 {
740 switch (ffl->type) {
741 case F_UNLCK:
742 break;
743
744 case F_RDLCK:
745 case F_WRLCK:
746 if (ffl->start > OFFSET_MAX || ffl->end > OFFSET_MAX ||
747 ffl->end < ffl->start)
748 return -EIO;
749
750 fl->fl_start = ffl->start;
751 fl->fl_end = ffl->end;
752 fl->fl_pid = ffl->pid;
753 break;
754
755 default:
756 return -EIO;
757 }
758 fl->fl_type = ffl->type;
759 return 0;
760 }
761
762 static void fuse_lk_fill(struct fuse_req *req, struct file *file,
763 const struct file_lock *fl, int opcode, pid_t pid,
764 int flock)
765 {
766 struct inode *inode = file->f_path.dentry->d_inode;
767 struct fuse_conn *fc = get_fuse_conn(inode);
768 struct fuse_file *ff = file->private_data;
769 struct fuse_lk_in *arg = &req->misc.lk_in;
770
771 arg->fh = ff->fh;
772 arg->owner = fuse_lock_owner_id(fc, fl->fl_owner);
773 arg->lk.start = fl->fl_start;
774 arg->lk.end = fl->fl_end;
775 arg->lk.type = fl->fl_type;
776 arg->lk.pid = pid;
777 if (flock)
778 arg->lk_flags |= FUSE_LK_FLOCK;
779 req->in.h.opcode = opcode;
780 req->in.h.nodeid = get_node_id(inode);
781 req->in.numargs = 1;
782 req->in.args[0].size = sizeof(*arg);
783 req->in.args[0].value = arg;
784 }
785
786 static int fuse_getlk(struct file *file, struct file_lock *fl)
787 {
788 struct inode *inode = file->f_path.dentry->d_inode;
789 struct fuse_conn *fc = get_fuse_conn(inode);
790 struct fuse_req *req;
791 struct fuse_lk_out outarg;
792 int err;
793
794 req = fuse_get_req(fc);
795 if (IS_ERR(req))
796 return PTR_ERR(req);
797
798 fuse_lk_fill(req, file, fl, FUSE_GETLK, 0, 0);
799 req->out.numargs = 1;
800 req->out.args[0].size = sizeof(outarg);
801 req->out.args[0].value = &outarg;
802 request_send(fc, req);
803 err = req->out.h.error;
804 fuse_put_request(fc, req);
805 if (!err)
806 err = convert_fuse_file_lock(&outarg.lk, fl);
807
808 return err;
809 }
810
811 static int fuse_setlk(struct file *file, struct file_lock *fl, int flock)
812 {
813 struct inode *inode = file->f_path.dentry->d_inode;
814 struct fuse_conn *fc = get_fuse_conn(inode);
815 struct fuse_req *req;
816 int opcode = (fl->fl_flags & FL_SLEEP) ? FUSE_SETLKW : FUSE_SETLK;
817 pid_t pid = fl->fl_type != F_UNLCK ? current->tgid : 0;
818 int err;
819
820 /* Unlock on close is handled by the flush method */
821 if (fl->fl_flags & FL_CLOSE)
822 return 0;
823
824 req = fuse_get_req(fc);
825 if (IS_ERR(req))
826 return PTR_ERR(req);
827
828 fuse_lk_fill(req, file, fl, opcode, pid, flock);
829 request_send(fc, req);
830 err = req->out.h.error;
831 /* locking is restartable */
832 if (err == -EINTR)
833 err = -ERESTARTSYS;
834 fuse_put_request(fc, req);
835 return err;
836 }
837
838 static int fuse_file_lock(struct file *file, int cmd, struct file_lock *fl)
839 {
840 struct inode *inode = file->f_path.dentry->d_inode;
841 struct fuse_conn *fc = get_fuse_conn(inode);
842 int err;
843
844 if (cmd == F_GETLK) {
845 if (fc->no_lock) {
846 posix_test_lock(file, fl);
847 err = 0;
848 } else
849 err = fuse_getlk(file, fl);
850 } else {
851 if (fc->no_lock)
852 err = posix_lock_file_wait(file, fl);
853 else
854 err = fuse_setlk(file, fl, 0);
855 }
856 return err;
857 }
858
859 static int fuse_file_flock(struct file *file, int cmd, struct file_lock *fl)
860 {
861 struct inode *inode = file->f_path.dentry->d_inode;
862 struct fuse_conn *fc = get_fuse_conn(inode);
863 int err;
864
865 if (fc->no_lock) {
866 err = flock_lock_file_wait(file, fl);
867 } else {
868 /* emulate flock with POSIX locks */
869 fl->fl_owner = (fl_owner_t) file;
870 err = fuse_setlk(file, fl, 1);
871 }
872
873 return err;
874 }
875
876 static sector_t fuse_bmap(struct address_space *mapping, sector_t block)
877 {
878 struct inode *inode = mapping->host;
879 struct fuse_conn *fc = get_fuse_conn(inode);
880 struct fuse_req *req;
881 struct fuse_bmap_in inarg;
882 struct fuse_bmap_out outarg;
883 int err;
884
885 if (!inode->i_sb->s_bdev || fc->no_bmap)
886 return 0;
887
888 req = fuse_get_req(fc);
889 if (IS_ERR(req))
890 return 0;
891
892 memset(&inarg, 0, sizeof(inarg));
893 inarg.block = block;
894 inarg.blocksize = inode->i_sb->s_blocksize;
895 req->in.h.opcode = FUSE_BMAP;
896 req->in.h.nodeid = get_node_id(inode);
897 req->in.numargs = 1;
898 req->in.args[0].size = sizeof(inarg);
899 req->in.args[0].value = &inarg;
900 req->out.numargs = 1;
901 req->out.args[0].size = sizeof(outarg);
902 req->out.args[0].value = &outarg;
903 request_send(fc, req);
904 err = req->out.h.error;
905 fuse_put_request(fc, req);
906 if (err == -ENOSYS)
907 fc->no_bmap = 1;
908
909 return err ? 0 : outarg.block;
910 }
911
912 static const struct file_operations fuse_file_operations = {
913 .llseek = generic_file_llseek,
914 .read = do_sync_read,
915 .aio_read = fuse_file_aio_read,
916 .write = do_sync_write,
917 .aio_write = generic_file_aio_write,
918 .mmap = fuse_file_mmap,
919 .open = fuse_open,
920 .flush = fuse_flush,
921 .release = fuse_release,
922 .fsync = fuse_fsync,
923 .lock = fuse_file_lock,
924 .flock = fuse_file_flock,
925 .splice_read = generic_file_splice_read,
926 };
927
928 static const struct file_operations fuse_direct_io_file_operations = {
929 .llseek = generic_file_llseek,
930 .read = fuse_direct_read,
931 .write = fuse_direct_write,
932 .open = fuse_open,
933 .flush = fuse_flush,
934 .release = fuse_release,
935 .fsync = fuse_fsync,
936 .lock = fuse_file_lock,
937 .flock = fuse_file_flock,
938 /* no mmap and splice_read */
939 };
940
941 static const struct address_space_operations fuse_file_aops = {
942 .readpage = fuse_readpage,
943 .write_begin = fuse_write_begin,
944 .write_end = fuse_write_end,
945 .readpages = fuse_readpages,
946 .set_page_dirty = fuse_set_page_dirty,
947 .bmap = fuse_bmap,
948 };
949
950 void fuse_init_file_inode(struct inode *inode)
951 {
952 inode->i_fop = &fuse_file_operations;
953 inode->i_data.a_ops = &fuse_file_aops;
954 }
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