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revert-mm-fix-blkdev-size-calculation-in-generic_write_checks
[linux-2.6/linux-trees-mm.git] / fs / fuse / file.c
blobbb05d227cf30bb074da715a08d438e295fbc8892
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->dentry);
81 mntput(req->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 fuse_conn *fc = get_fuse_conn(req->dentry->d_inode);
90 req->end = fuse_release_end;
91 request_send_background(fc, req);
92 kfree(ff);
93 }
94 }
95
96 void fuse_finish_open(struct inode *inode, struct file *file,
97 struct fuse_file *ff, struct fuse_open_out *outarg)
98 {
99 if (outarg->open_flags & FOPEN_DIRECT_IO)
100 file->f_op = &fuse_direct_io_file_operations;
101 if (!(outarg->open_flags & FOPEN_KEEP_CACHE))
102 invalidate_inode_pages2(inode->i_mapping);
103 ff->fh = outarg->fh;
104 file->private_data = fuse_file_get(ff);
105 }
106
107 int fuse_open_common(struct inode *inode, struct file *file, int isdir)
108 {
109 struct fuse_open_out outarg;
110 struct fuse_file *ff;
111 int err;
112
113 /* VFS checks this, but only _after_ ->open() */
114 if (file->f_flags & O_DIRECT)
115 return -EINVAL;
116
117 err = generic_file_open(inode, file);
118 if (err)
119 return err;
120
121 ff = fuse_file_alloc();
122 if (!ff)
123 return -ENOMEM;
124
125 err = fuse_send_open(inode, file, isdir, &outarg);
126 if (err)
127 fuse_file_free(ff);
128 else {
129 if (isdir)
130 outarg.open_flags &= ~FOPEN_DIRECT_IO;
131 fuse_finish_open(inode, file, ff, &outarg);
132 }
133
134 return err;
135 }
136
137 void fuse_release_fill(struct fuse_file *ff, u64 nodeid, int flags, int opcode)
138 {
139 struct fuse_req *req = ff->reserved_req;
140 struct fuse_release_in *inarg = &req->misc.release_in;
141
142 inarg->fh = ff->fh;
143 inarg->flags = flags;
144 req->in.h.opcode = opcode;
145 req->in.h.nodeid = nodeid;
146 req->in.numargs = 1;
147 req->in.args[0].size = sizeof(struct fuse_release_in);
148 req->in.args[0].value = inarg;
149 }
150
151 int fuse_release_common(struct inode *inode, struct file *file, int isdir)
152 {
153 struct fuse_file *ff = file->private_data;
154 if (ff) {
155 struct fuse_conn *fc = get_fuse_conn(inode);
156
157 fuse_release_fill(ff, get_node_id(inode), file->f_flags,
158 isdir ? FUSE_RELEASEDIR : FUSE_RELEASE);
159
160 /* Hold vfsmount and dentry until release is finished */
161 ff->reserved_req->vfsmount = mntget(file->f_path.mnt);
162 ff->reserved_req->dentry = dget(file->f_path.dentry);
163
164 spin_lock(&fc->lock);
165 list_del(&ff->write_entry);
166 spin_unlock(&fc->lock);
167 /*
168 * Normally this will send the RELEASE request,
169 * however if some asynchronous READ or WRITE requests
170 * are outstanding, the sending will be delayed
171 */
172 fuse_file_put(ff);
173 }
174
175 /* Return value is ignored by VFS */
176 return 0;
177 }
178
179 static int fuse_open(struct inode *inode, struct file *file)
180 {
181 return fuse_open_common(inode, file, 0);
182 }
183
184 static int fuse_release(struct inode *inode, struct file *file)
185 {
186 return fuse_release_common(inode, file, 0);
187 }
188
189 /*
190 * Scramble the ID space with XTEA, so that the value of the files_struct
191 * pointer is not exposed to userspace.
192 */
193 u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id)
194 {
195 u32 *k = fc->scramble_key;
196 u64 v = (unsigned long) id;
197 u32 v0 = v;
198 u32 v1 = v >> 32;
199 u32 sum = 0;
200 int i;
201
202 for (i = 0; i < 32; i++) {
203 v0 += ((v1 << 4 ^ v1 >> 5) + v1) ^ (sum + k[sum & 3]);
204 sum += 0x9E3779B9;
205 v1 += ((v0 << 4 ^ v0 >> 5) + v0) ^ (sum + k[sum>>11 & 3]);
206 }
207
208 return (u64) v0 + ((u64) v1 << 32);
209 }
210
211 static int fuse_flush(struct file *file, fl_owner_t id)
212 {
213 struct inode *inode = file->f_path.dentry->d_inode;
214 struct fuse_conn *fc = get_fuse_conn(inode);
215 struct fuse_file *ff = file->private_data;
216 struct fuse_req *req;
217 struct fuse_flush_in inarg;
218 int err;
219
220 if (is_bad_inode(inode))
221 return -EIO;
222
223 if (fc->no_flush)
224 return 0;
225
226 req = fuse_get_req_nofail(fc, file);
227 memset(&inarg, 0, sizeof(inarg));
228 inarg.fh = ff->fh;
229 inarg.lock_owner = fuse_lock_owner_id(fc, id);
230 req->in.h.opcode = FUSE_FLUSH;
231 req->in.h.nodeid = get_node_id(inode);
232 req->in.numargs = 1;
233 req->in.args[0].size = sizeof(inarg);
234 req->in.args[0].value = &inarg;
235 req->force = 1;
236 request_send(fc, req);
237 err = req->out.h.error;
238 fuse_put_request(fc, req);
239 if (err == -ENOSYS) {
240 fc->no_flush = 1;
241 err = 0;
242 }
243 return err;
244 }
245
246 int fuse_fsync_common(struct file *file, struct dentry *de, int datasync,
247 int isdir)
248 {
249 struct inode *inode = de->d_inode;
250 struct fuse_conn *fc = get_fuse_conn(inode);
251 struct fuse_file *ff = file->private_data;
252 struct fuse_req *req;
253 struct fuse_fsync_in inarg;
254 int err;
255
256 if (is_bad_inode(inode))
257 return -EIO;
258
259 if ((!isdir && fc->no_fsync) || (isdir && fc->no_fsyncdir))
260 return 0;
261
262 req = fuse_get_req(fc);
263 if (IS_ERR(req))
264 return PTR_ERR(req);
265
266 memset(&inarg, 0, sizeof(inarg));
267 inarg.fh = ff->fh;
268 inarg.fsync_flags = datasync ? 1 : 0;
269 req->in.h.opcode = isdir ? FUSE_FSYNCDIR : FUSE_FSYNC;
270 req->in.h.nodeid = get_node_id(inode);
271 req->in.numargs = 1;
272 req->in.args[0].size = sizeof(inarg);
273 req->in.args[0].value = &inarg;
274 request_send(fc, req);
275 err = req->out.h.error;
276 fuse_put_request(fc, req);
277 if (err == -ENOSYS) {
278 if (isdir)
279 fc->no_fsyncdir = 1;
280 else
281 fc->no_fsync = 1;
282 err = 0;
283 }
284 return err;
285 }
286
287 static int fuse_fsync(struct file *file, struct dentry *de, int datasync)
288 {
289 return fuse_fsync_common(file, de, datasync, 0);
290 }
291
292 void fuse_read_fill(struct fuse_req *req, struct file *file,
293 struct inode *inode, loff_t pos, size_t count, int opcode)
294 {
295 struct fuse_read_in *inarg = &req->misc.read_in;
296 struct fuse_file *ff = file->private_data;
297
298 inarg->fh = ff->fh;
299 inarg->offset = pos;
300 inarg->size = count;
301 inarg->flags = file->f_flags;
302 req->in.h.opcode = opcode;
303 req->in.h.nodeid = get_node_id(inode);
304 req->in.numargs = 1;
305 req->in.args[0].size = sizeof(struct fuse_read_in);
306 req->in.args[0].value = inarg;
307 req->out.argpages = 1;
308 req->out.argvar = 1;
309 req->out.numargs = 1;
310 req->out.args[0].size = count;
311 }
312
313 static size_t fuse_send_read(struct fuse_req *req, struct file *file,
314 struct inode *inode, loff_t pos, size_t count,
315 fl_owner_t owner)
316 {
317 struct fuse_conn *fc = get_fuse_conn(inode);
318
319 fuse_read_fill(req, file, inode, pos, count, FUSE_READ);
320 if (owner != NULL) {
321 struct fuse_read_in *inarg = &req->misc.read_in;
322
323 inarg->read_flags |= FUSE_READ_LOCKOWNER;
324 inarg->lock_owner = fuse_lock_owner_id(fc, owner);
325 }
326 request_send(fc, req);
327 return req->out.args[0].size;
328 }
329
330 static int fuse_readpage(struct file *file, struct page *page)
331 {
332 struct inode *inode = page->mapping->host;
333 struct fuse_conn *fc = get_fuse_conn(inode);
334 struct fuse_req *req;
335 int err;
336
337 err = -EIO;
338 if (is_bad_inode(inode))
339 goto out;
340
341 req = fuse_get_req(fc);
342 err = PTR_ERR(req);
343 if (IS_ERR(req))
344 goto out;
345
346 req->out.page_zeroing = 1;
347 req->num_pages = 1;
348 req->pages[0] = page;
349 fuse_send_read(req, file, inode, page_offset(page), PAGE_CACHE_SIZE,
350 NULL);
351 err = req->out.h.error;
352 fuse_put_request(fc, req);
353 if (!err)
354 SetPageUptodate(page);
355 fuse_invalidate_attr(inode); /* atime changed */
356 out:
357 unlock_page(page);
358 return err;
359 }
360
361 static void fuse_readpages_end(struct fuse_conn *fc, struct fuse_req *req)
362 {
363 int i;
364
365 fuse_invalidate_attr(req->pages[0]->mapping->host); /* atime changed */
366
367 for (i = 0; i < req->num_pages; i++) {
368 struct page *page = req->pages[i];
369 if (!req->out.h.error)
370 SetPageUptodate(page);
371 else
372 SetPageError(page);
373 unlock_page(page);
374 }
375 if (req->ff)
376 fuse_file_put(req->ff);
377 fuse_put_request(fc, req);
378 }
379
380 static void fuse_send_readpages(struct fuse_req *req, struct file *file,
381 struct inode *inode)
382 {
383 struct fuse_conn *fc = get_fuse_conn(inode);
384 loff_t pos = page_offset(req->pages[0]);
385 size_t count = req->num_pages << PAGE_CACHE_SHIFT;
386 req->out.page_zeroing = 1;
387 fuse_read_fill(req, file, inode, pos, count, FUSE_READ);
388 if (fc->async_read) {
389 struct fuse_file *ff = file->private_data;
390 req->ff = fuse_file_get(ff);
391 req->end = fuse_readpages_end;
392 request_send_background(fc, req);
393 } else {
394 request_send(fc, req);
395 fuse_readpages_end(fc, req);
396 }
397 }
398
399 struct fuse_fill_data {
400 struct fuse_req *req;
401 struct file *file;
402 struct inode *inode;
403 };
404
405 static int fuse_readpages_fill(void *_data, struct page *page)
406 {
407 struct fuse_fill_data *data = _data;
408 struct fuse_req *req = data->req;
409 struct inode *inode = data->inode;
410 struct fuse_conn *fc = get_fuse_conn(inode);
411
412 if (req->num_pages &&
413 (req->num_pages == FUSE_MAX_PAGES_PER_REQ ||
414 (req->num_pages + 1) * PAGE_CACHE_SIZE > fc->max_read ||
415 req->pages[req->num_pages - 1]->index + 1 != page->index)) {
416 fuse_send_readpages(req, data->file, inode);
417 data->req = req = fuse_get_req(fc);
418 if (IS_ERR(req)) {
419 unlock_page(page);
420 return PTR_ERR(req);
421 }
422 }
423 req->pages[req->num_pages] = page;
424 req->num_pages ++;
425 return 0;
426 }
427
428 static int fuse_readpages(struct file *file, struct address_space *mapping,
429 struct list_head *pages, unsigned nr_pages)
430 {
431 struct inode *inode = mapping->host;
432 struct fuse_conn *fc = get_fuse_conn(inode);
433 struct fuse_fill_data data;
434 int err;
435
436 err = -EIO;
437 if (is_bad_inode(inode))
438 goto out;
439
440 data.file = file;
441 data.inode = inode;
442 data.req = fuse_get_req(fc);
443 err = PTR_ERR(data.req);
444 if (IS_ERR(data.req))
445 goto out;
446
447 err = read_cache_pages(mapping, pages, fuse_readpages_fill, &data);
448 if (!err) {
449 if (data.req->num_pages)
450 fuse_send_readpages(data.req, file, inode);
451 else
452 fuse_put_request(fc, data.req);
453 }
454 out:
455 return err;
456 }
457
458 static ssize_t fuse_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
459 unsigned long nr_segs, loff_t pos)
460 {
461 struct inode *inode = iocb->ki_filp->f_mapping->host;
462
463 if (pos + iov_length(iov, nr_segs) > i_size_read(inode)) {
464 int err;
465 /*
466 * If trying to read past EOF, make sure the i_size
467 * attribute is up-to-date.
468 */
469 err = fuse_update_attributes(inode, NULL, iocb->ki_filp, NULL);
470 if (err)
471 return err;
472 }
473
474 return generic_file_aio_read(iocb, iov, nr_segs, pos);
475 }
476
477 static void fuse_write_fill(struct fuse_req *req, struct file *file,
478 struct inode *inode, loff_t pos, size_t count,
479 int writepage)
480 {
481 struct fuse_conn *fc = get_fuse_conn(inode);
482 struct fuse_file *ff = file->private_data;
483 struct fuse_write_in *inarg = &req->misc.write.in;
484 struct fuse_write_out *outarg = &req->misc.write.out;
485
486 memset(inarg, 0, sizeof(struct fuse_write_in));
487 inarg->fh = ff->fh;
488 inarg->offset = pos;
489 inarg->size = count;
490 inarg->write_flags = writepage ? FUSE_WRITE_CACHE : 0;
491 inarg->flags = file->f_flags;
492 req->in.h.opcode = FUSE_WRITE;
493 req->in.h.nodeid = get_node_id(inode);
494 req->in.argpages = 1;
495 req->in.numargs = 2;
496 if (fc->minor < 9)
497 req->in.args[0].size = FUSE_COMPAT_WRITE_IN_SIZE;
498 else
499 req->in.args[0].size = sizeof(struct fuse_write_in);
500 req->in.args[0].value = inarg;
501 req->in.args[1].size = count;
502 req->out.numargs = 1;
503 req->out.args[0].size = sizeof(struct fuse_write_out);
504 req->out.args[0].value = outarg;
505 }
506
507 static size_t fuse_send_write(struct fuse_req *req, struct file *file,
508 struct inode *inode, loff_t pos, size_t count,
509 fl_owner_t owner)
510 {
511 struct fuse_conn *fc = get_fuse_conn(inode);
512 fuse_write_fill(req, file, inode, pos, count, 0);
513 if (owner != NULL) {
514 struct fuse_write_in *inarg = &req->misc.write.in;
515 inarg->write_flags |= FUSE_WRITE_LOCKOWNER;
516 inarg->lock_owner = fuse_lock_owner_id(fc, owner);
517 }
518 request_send(fc, req);
519 return req->misc.write.out.size;
520 }
521
522 static int fuse_write_begin(struct file *file, struct address_space *mapping,
523 loff_t pos, unsigned len, unsigned flags,
524 struct page **pagep, void **fsdata)
525 {
526 pgoff_t index = pos >> PAGE_CACHE_SHIFT;
527
528 *pagep = __grab_cache_page(mapping, index);
529 if (!*pagep)
530 return -ENOMEM;
531 return 0;
532 }
533
534 static int fuse_buffered_write(struct file *file, struct inode *inode,
535 loff_t pos, unsigned count, struct page *page)
536 {
537 int err;
538 size_t nres;
539 struct fuse_conn *fc = get_fuse_conn(inode);
540 struct fuse_inode *fi = get_fuse_inode(inode);
541 unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
542 struct fuse_req *req;
543
544 if (is_bad_inode(inode))
545 return -EIO;
546
547 req = fuse_get_req(fc);
548 if (IS_ERR(req))
549 return PTR_ERR(req);
550
551 req->num_pages = 1;
552 req->pages[0] = page;
553 req->page_offset = offset;
554 nres = fuse_send_write(req, file, inode, pos, count, NULL);
555 err = req->out.h.error;
556 fuse_put_request(fc, req);
557 if (!err && !nres)
558 err = -EIO;
559 if (!err) {
560 pos += nres;
561 spin_lock(&fc->lock);
562 fi->attr_version = ++fc->attr_version;
563 if (pos > inode->i_size)
564 i_size_write(inode, pos);
565 spin_unlock(&fc->lock);
566
567 if (count == PAGE_CACHE_SIZE)
568 SetPageUptodate(page);
569 }
570 fuse_invalidate_attr(inode);
571 return err ? err : nres;
572 }
573
574 static int fuse_write_end(struct file *file, struct address_space *mapping,
575 loff_t pos, unsigned len, unsigned copied,
576 struct page *page, void *fsdata)
577 {
578 struct inode *inode = mapping->host;
579 int res = 0;
580
581 if (copied)
582 res = fuse_buffered_write(file, inode, pos, copied, page);
583
584 unlock_page(page);
585 page_cache_release(page);
586 return res;
587 }
588
589 static void fuse_release_user_pages(struct fuse_req *req, int write)
590 {
591 unsigned i;
592
593 for (i = 0; i < req->num_pages; i++) {
594 struct page *page = req->pages[i];
595 if (write)
596 set_page_dirty_lock(page);
597 put_page(page);
598 }
599 }
600
601 static int fuse_get_user_pages(struct fuse_req *req, const char __user *buf,
602 unsigned nbytes, int write)
603 {
604 unsigned long user_addr = (unsigned long) buf;
605 unsigned offset = user_addr & ~PAGE_MASK;
606 int npages;
607
608 /* This doesn't work with nfsd */
609 if (!current->mm)
610 return -EPERM;
611
612 nbytes = min(nbytes, (unsigned) FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT);
613 npages = (nbytes + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
614 npages = min(max(npages, 1), FUSE_MAX_PAGES_PER_REQ);
615 down_read(&current->mm->mmap_sem);
616 npages = get_user_pages(current, current->mm, user_addr, npages, write,
617 0, req->pages, NULL);
618 up_read(&current->mm->mmap_sem);
619 if (npages < 0)
620 return npages;
621
622 req->num_pages = npages;
623 req->page_offset = offset;
624 return 0;
625 }
626
627 static ssize_t fuse_direct_io(struct file *file, const char __user *buf,
628 size_t count, loff_t *ppos, int write)
629 {
630 struct inode *inode = file->f_path.dentry->d_inode;
631 struct fuse_conn *fc = get_fuse_conn(inode);
632 size_t nmax = write ? fc->max_write : fc->max_read;
633 loff_t pos = *ppos;
634 ssize_t res = 0;
635 struct fuse_req *req;
636
637 if (is_bad_inode(inode))
638 return -EIO;
639
640 req = fuse_get_req(fc);
641 if (IS_ERR(req))
642 return PTR_ERR(req);
643
644 while (count) {
645 size_t nres;
646 size_t nbytes = min(count, nmax);
647 int err = fuse_get_user_pages(req, buf, nbytes, !write);
648 if (err) {
649 res = err;
650 break;
651 }
652 nbytes = (req->num_pages << PAGE_SHIFT) - req->page_offset;
653 nbytes = min(count, nbytes);
654 if (write)
655 nres = fuse_send_write(req, file, inode, pos, nbytes,
656 current->files);
657 else
658 nres = fuse_send_read(req, file, inode, pos, nbytes,
659 current->files);
660 fuse_release_user_pages(req, !write);
661 if (req->out.h.error) {
662 if (!res)
663 res = req->out.h.error;
664 break;
665 } else if (nres > nbytes) {
666 res = -EIO;
667 break;
668 }
669 count -= nres;
670 res += nres;
671 pos += nres;
672 buf += nres;
673 if (nres != nbytes)
674 break;
675 if (count) {
676 fuse_put_request(fc, req);
677 req = fuse_get_req(fc);
678 if (IS_ERR(req))
679 break;
680 }
681 }
682 fuse_put_request(fc, req);
683 if (res > 0) {
684 if (write) {
685 spin_lock(&fc->lock);
686 if (pos > inode->i_size)
687 i_size_write(inode, pos);
688 spin_unlock(&fc->lock);
689 }
690 *ppos = pos;
691 }
692 fuse_invalidate_attr(inode);
693
694 return res;
695 }
696
697 static ssize_t fuse_direct_read(struct file *file, char __user *buf,
698 size_t count, loff_t *ppos)
699 {
700 return fuse_direct_io(file, buf, count, ppos, 0);
701 }
702
703 static ssize_t fuse_direct_write(struct file *file, const char __user *buf,
704 size_t count, loff_t *ppos)
705 {
706 struct inode *inode = file->f_path.dentry->d_inode;
707 ssize_t res;
708 /* Don't allow parallel writes to the same file */
709 mutex_lock(&inode->i_mutex);
710 res = generic_write_checks(file, ppos, &count, 0);
711 if (!res)
712 res = fuse_direct_io(file, buf, count, ppos, 1);
713 mutex_unlock(&inode->i_mutex);
714 return res;
715 }
716
717 static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma)
718 {
719 if ((vma->vm_flags & VM_SHARED)) {
720 if ((vma->vm_flags & VM_WRITE))
721 return -ENODEV;
722 else
723 vma->vm_flags &= ~VM_MAYWRITE;
724 }
725 return generic_file_mmap(file, vma);
726 }
727
728 static int fuse_set_page_dirty(struct page *page)
729 {
730 printk("fuse_set_page_dirty: should not happen\n");
731 dump_stack();
732 return 0;
733 }
734
735 static int convert_fuse_file_lock(const struct fuse_file_lock *ffl,
736 struct file_lock *fl)
737 {
738 switch (ffl->type) {
739 case F_UNLCK:
740 break;
741
742 case F_RDLCK:
743 case F_WRLCK:
744 if (ffl->start > OFFSET_MAX || ffl->end > OFFSET_MAX ||
745 ffl->end < ffl->start)
746 return -EIO;
747
748 fl->fl_start = ffl->start;
749 fl->fl_end = ffl->end;
750 fl->fl_pid = ffl->pid;
751 break;
752
753 default:
754 return -EIO;
755 }
756 fl->fl_type = ffl->type;
757 return 0;
758 }
759
760 static void fuse_lk_fill(struct fuse_req *req, struct file *file,
761 const struct file_lock *fl, int opcode, pid_t pid,
762 int flock)
763 {
764 struct inode *inode = file->f_path.dentry->d_inode;
765 struct fuse_conn *fc = get_fuse_conn(inode);
766 struct fuse_file *ff = file->private_data;
767 struct fuse_lk_in *arg = &req->misc.lk_in;
768
769 arg->fh = ff->fh;
770 arg->owner = fuse_lock_owner_id(fc, fl->fl_owner);
771 arg->lk.start = fl->fl_start;
772 arg->lk.end = fl->fl_end;
773 arg->lk.type = fl->fl_type;
774 arg->lk.pid = pid;
775 if (flock)
776 arg->lk_flags |= FUSE_LK_FLOCK;
777 req->in.h.opcode = opcode;
778 req->in.h.nodeid = get_node_id(inode);
779 req->in.numargs = 1;
780 req->in.args[0].size = sizeof(*arg);
781 req->in.args[0].value = arg;
782 }
783
784 static int fuse_getlk(struct file *file, struct file_lock *fl)
785 {
786 struct inode *inode = file->f_path.dentry->d_inode;
787 struct fuse_conn *fc = get_fuse_conn(inode);
788 struct fuse_req *req;
789 struct fuse_lk_out outarg;
790 int err;
791
792 req = fuse_get_req(fc);
793 if (IS_ERR(req))
794 return PTR_ERR(req);
795
796 fuse_lk_fill(req, file, fl, FUSE_GETLK, 0, 0);
797 req->out.numargs = 1;
798 req->out.args[0].size = sizeof(outarg);
799 req->out.args[0].value = &outarg;
800 request_send(fc, req);
801 err = req->out.h.error;
802 fuse_put_request(fc, req);
803 if (!err)
804 err = convert_fuse_file_lock(&outarg.lk, fl);
805
806 return err;
807 }
808
809 static int fuse_setlk(struct file *file, struct file_lock *fl, int flock)
810 {
811 struct inode *inode = file->f_path.dentry->d_inode;
812 struct fuse_conn *fc = get_fuse_conn(inode);
813 struct fuse_req *req;
814 int opcode = (fl->fl_flags & FL_SLEEP) ? FUSE_SETLKW : FUSE_SETLK;
815 pid_t pid = fl->fl_type != F_UNLCK ? current->tgid : 0;
816 int err;
817
818 /* Unlock on close is handled by the flush method */
819 if (fl->fl_flags & FL_CLOSE)
820 return 0;
821
822 req = fuse_get_req(fc);
823 if (IS_ERR(req))
824 return PTR_ERR(req);
825
826 fuse_lk_fill(req, file, fl, opcode, pid, flock);
827 request_send(fc, req);
828 err = req->out.h.error;
829 /* locking is restartable */
830 if (err == -EINTR)
831 err = -ERESTARTSYS;
832 fuse_put_request(fc, req);
833 return err;
834 }
835
836 static int fuse_file_lock(struct file *file, int cmd, struct file_lock *fl)
837 {
838 struct inode *inode = file->f_path.dentry->d_inode;
839 struct fuse_conn *fc = get_fuse_conn(inode);
840 int err;
841
842 if (cmd == F_GETLK) {
843 if (fc->no_lock) {
844 posix_test_lock(file, fl);
845 err = 0;
846 } else
847 err = fuse_getlk(file, fl);
848 } else {
849 if (fc->no_lock)
850 err = posix_lock_file_wait(file, fl);
851 else
852 err = fuse_setlk(file, fl, 0);
853 }
854 return err;
855 }
856
857 static int fuse_file_flock(struct file *file, int cmd, struct file_lock *fl)
858 {
859 struct inode *inode = file->f_path.dentry->d_inode;
860 struct fuse_conn *fc = get_fuse_conn(inode);
861 int err;
862
863 if (fc->no_lock) {
864 err = flock_lock_file_wait(file, fl);
865 } else {
866 /* emulate flock with POSIX locks */
867 fl->fl_owner = (fl_owner_t) file;
868 err = fuse_setlk(file, fl, 1);
869 }
870
871 return err;
872 }
873
874 static sector_t fuse_bmap(struct address_space *mapping, sector_t block)
875 {
876 struct inode *inode = mapping->host;
877 struct fuse_conn *fc = get_fuse_conn(inode);
878 struct fuse_req *req;
879 struct fuse_bmap_in inarg;
880 struct fuse_bmap_out outarg;
881 int err;
882
883 if (!inode->i_sb->s_bdev || fc->no_bmap)
884 return 0;
885
886 req = fuse_get_req(fc);
887 if (IS_ERR(req))
888 return 0;
889
890 memset(&inarg, 0, sizeof(inarg));
891 inarg.block = block;
892 inarg.blocksize = inode->i_sb->s_blocksize;
893 req->in.h.opcode = FUSE_BMAP;
894 req->in.h.nodeid = get_node_id(inode);
895 req->in.numargs = 1;
896 req->in.args[0].size = sizeof(inarg);
897 req->in.args[0].value = &inarg;
898 req->out.numargs = 1;
899 req->out.args[0].size = sizeof(outarg);
900 req->out.args[0].value = &outarg;
901 request_send(fc, req);
902 err = req->out.h.error;
903 fuse_put_request(fc, req);
904 if (err == -ENOSYS)
905 fc->no_bmap = 1;
906
907 return err ? 0 : outarg.block;
908 }
909
910 static const struct file_operations fuse_file_operations = {
911 .llseek = generic_file_llseek,
912 .read = do_sync_read,
913 .aio_read = fuse_file_aio_read,
914 .write = do_sync_write,
915 .aio_write = generic_file_aio_write,
916 .mmap = fuse_file_mmap,
917 .open = fuse_open,
918 .flush = fuse_flush,
919 .release = fuse_release,
920 .fsync = fuse_fsync,
921 .lock = fuse_file_lock,
922 .flock = fuse_file_flock,
923 .splice_read = generic_file_splice_read,
924 };
925
926 static const struct file_operations fuse_direct_io_file_operations = {
927 .llseek = generic_file_llseek,
928 .read = fuse_direct_read,
929 .write = fuse_direct_write,
930 .open = fuse_open,
931 .flush = fuse_flush,
932 .release = fuse_release,
933 .fsync = fuse_fsync,
934 .lock = fuse_file_lock,
935 .flock = fuse_file_flock,
936 /* no mmap and splice_read */
937 };
938
939 static const struct address_space_operations fuse_file_aops = {
940 .readpage = fuse_readpage,
941 .write_begin = fuse_write_begin,
942 .write_end = fuse_write_end,
943 .readpages = fuse_readpages,
944 .set_page_dirty = fuse_set_page_dirty,
945 .bmap = fuse_bmap,
946 };
947
948 void fuse_init_file_inode(struct inode *inode)
949 {
950 inode->i_fop = &fuse_file_operations;
951 inode->i_data.a_ops = &fuse_file_aops;
952 }
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