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