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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 | #include <linux/module.h> | |
16 | #include <linux/compat.h> | |
17 | #include <linux/swap.h> | |
18 | #include <linux/falloc.h> | |
19 | #include <linux/uio.h> | |
20 | ||
21 | static const struct file_operations fuse_direct_io_file_operations; | |
22 | ||
23 | static int fuse_send_open(struct fuse_conn *fc, u64 nodeid, struct file *file, | |
24 | int opcode, struct fuse_open_out *outargp) | |
25 | { | |
26 | struct fuse_open_in inarg; | |
27 | FUSE_ARGS(args); | |
28 | ||
29 | memset(&inarg, 0, sizeof(inarg)); | |
30 | inarg.flags = file->f_flags & ~(O_CREAT | O_EXCL | O_NOCTTY); | |
31 | if (!fc->atomic_o_trunc) | |
32 | inarg.flags &= ~O_TRUNC; | |
33 | args.in.h.opcode = opcode; | |
34 | args.in.h.nodeid = nodeid; | |
35 | args.in.numargs = 1; | |
36 | args.in.args[0].size = sizeof(inarg); | |
37 | args.in.args[0].value = &inarg; | |
38 | args.out.numargs = 1; | |
39 | args.out.args[0].size = sizeof(*outargp); | |
40 | args.out.args[0].value = outargp; | |
41 | ||
42 | return fuse_simple_request(fc, &args); | |
43 | } | |
44 | ||
45 | struct fuse_file *fuse_file_alloc(struct fuse_conn *fc) | |
46 | { | |
47 | struct fuse_file *ff; | |
48 | ||
49 | ff = kmalloc(sizeof(struct fuse_file), GFP_KERNEL); | |
50 | if (unlikely(!ff)) | |
51 | return NULL; | |
52 | ||
53 | ff->fc = fc; | |
54 | ff->reserved_req = fuse_request_alloc(0); | |
55 | if (unlikely(!ff->reserved_req)) { | |
56 | kfree(ff); | |
57 | return NULL; | |
58 | } | |
59 | ||
60 | INIT_LIST_HEAD(&ff->write_entry); | |
61 | atomic_set(&ff->count, 0); | |
62 | RB_CLEAR_NODE(&ff->polled_node); | |
63 | init_waitqueue_head(&ff->poll_wait); | |
64 | ||
65 | spin_lock(&fc->lock); | |
66 | ff->kh = ++fc->khctr; | |
67 | spin_unlock(&fc->lock); | |
68 | ||
69 | return ff; | |
70 | } | |
71 | ||
72 | void fuse_file_free(struct fuse_file *ff) | |
73 | { | |
74 | fuse_request_free(ff->reserved_req); | |
75 | kfree(ff); | |
76 | } | |
77 | ||
78 | struct fuse_file *fuse_file_get(struct fuse_file *ff) | |
79 | { | |
80 | atomic_inc(&ff->count); | |
81 | return ff; | |
82 | } | |
83 | ||
84 | static void fuse_release_end(struct fuse_conn *fc, struct fuse_req *req) | |
85 | { | |
86 | iput(req->misc.release.inode); | |
87 | } | |
88 | ||
89 | static void fuse_file_put(struct fuse_file *ff, bool sync) | |
90 | { | |
91 | if (atomic_dec_and_test(&ff->count)) { | |
92 | struct fuse_req *req = ff->reserved_req; | |
93 | ||
94 | if (ff->fc->no_open) { | |
95 | /* | |
96 | * Drop the release request when client does not | |
97 | * implement 'open' | |
98 | */ | |
99 | __clear_bit(FR_BACKGROUND, &req->flags); | |
100 | iput(req->misc.release.inode); | |
101 | fuse_put_request(ff->fc, req); | |
102 | } else if (sync) { | |
103 | __clear_bit(FR_BACKGROUND, &req->flags); | |
104 | fuse_request_send(ff->fc, req); | |
105 | iput(req->misc.release.inode); | |
106 | fuse_put_request(ff->fc, req); | |
107 | } else { | |
108 | req->end = fuse_release_end; | |
109 | __set_bit(FR_BACKGROUND, &req->flags); | |
110 | fuse_request_send_background(ff->fc, req); | |
111 | } | |
112 | kfree(ff); | |
113 | } | |
114 | } | |
115 | ||
116 | int fuse_do_open(struct fuse_conn *fc, u64 nodeid, struct file *file, | |
117 | bool isdir) | |
118 | { | |
119 | struct fuse_file *ff; | |
120 | int opcode = isdir ? FUSE_OPENDIR : FUSE_OPEN; | |
121 | ||
122 | ff = fuse_file_alloc(fc); | |
123 | if (!ff) | |
124 | return -ENOMEM; | |
125 | ||
126 | ff->fh = 0; | |
127 | ff->open_flags = FOPEN_KEEP_CACHE; /* Default for no-open */ | |
128 | if (!fc->no_open || isdir) { | |
129 | struct fuse_open_out outarg; | |
130 | int err; | |
131 | ||
132 | err = fuse_send_open(fc, nodeid, file, opcode, &outarg); | |
133 | if (!err) { | |
134 | ff->fh = outarg.fh; | |
135 | ff->open_flags = outarg.open_flags; | |
136 | ||
137 | } else if (err != -ENOSYS || isdir) { | |
138 | fuse_file_free(ff); | |
139 | return err; | |
140 | } else { | |
141 | fc->no_open = 1; | |
142 | } | |
143 | } | |
144 | ||
145 | if (isdir) | |
146 | ff->open_flags &= ~FOPEN_DIRECT_IO; | |
147 | ||
148 | ff->nodeid = nodeid; | |
149 | file->private_data = fuse_file_get(ff); | |
150 | ||
151 | return 0; | |
152 | } | |
153 | EXPORT_SYMBOL_GPL(fuse_do_open); | |
154 | ||
155 | static void fuse_link_write_file(struct file *file) | |
156 | { | |
157 | struct inode *inode = file_inode(file); | |
158 | struct fuse_conn *fc = get_fuse_conn(inode); | |
159 | struct fuse_inode *fi = get_fuse_inode(inode); | |
160 | struct fuse_file *ff = file->private_data; | |
161 | /* | |
162 | * file may be written through mmap, so chain it onto the | |
163 | * inodes's write_file list | |
164 | */ | |
165 | spin_lock(&fc->lock); | |
166 | if (list_empty(&ff->write_entry)) | |
167 | list_add(&ff->write_entry, &fi->write_files); | |
168 | spin_unlock(&fc->lock); | |
169 | } | |
170 | ||
171 | void fuse_finish_open(struct inode *inode, struct file *file) | |
172 | { | |
173 | struct fuse_file *ff = file->private_data; | |
174 | struct fuse_conn *fc = get_fuse_conn(inode); | |
175 | ||
176 | if (ff->open_flags & FOPEN_DIRECT_IO) | |
177 | file->f_op = &fuse_direct_io_file_operations; | |
178 | if (!(ff->open_flags & FOPEN_KEEP_CACHE)) | |
179 | invalidate_inode_pages2(inode->i_mapping); | |
180 | if (ff->open_flags & FOPEN_NONSEEKABLE) | |
181 | nonseekable_open(inode, file); | |
182 | if (fc->atomic_o_trunc && (file->f_flags & O_TRUNC)) { | |
183 | struct fuse_inode *fi = get_fuse_inode(inode); | |
184 | ||
185 | spin_lock(&fc->lock); | |
186 | fi->attr_version = ++fc->attr_version; | |
187 | i_size_write(inode, 0); | |
188 | spin_unlock(&fc->lock); | |
189 | fuse_invalidate_attr(inode); | |
190 | if (fc->writeback_cache) | |
191 | file_update_time(file); | |
192 | } | |
193 | if ((file->f_mode & FMODE_WRITE) && fc->writeback_cache) | |
194 | fuse_link_write_file(file); | |
195 | } | |
196 | ||
197 | int fuse_open_common(struct inode *inode, struct file *file, bool isdir) | |
198 | { | |
199 | struct fuse_conn *fc = get_fuse_conn(inode); | |
200 | int err; | |
201 | bool lock_inode = (file->f_flags & O_TRUNC) && | |
202 | fc->atomic_o_trunc && | |
203 | fc->writeback_cache; | |
204 | ||
205 | err = generic_file_open(inode, file); | |
206 | if (err) | |
207 | return err; | |
208 | ||
209 | if (lock_inode) | |
210 | inode_lock(inode); | |
211 | ||
212 | err = fuse_do_open(fc, get_node_id(inode), file, isdir); | |
213 | ||
214 | if (!err) | |
215 | fuse_finish_open(inode, file); | |
216 | ||
217 | if (lock_inode) | |
218 | inode_unlock(inode); | |
219 | ||
220 | return err; | |
221 | } | |
222 | ||
223 | static void fuse_prepare_release(struct fuse_file *ff, int flags, int opcode) | |
224 | { | |
225 | struct fuse_conn *fc = ff->fc; | |
226 | struct fuse_req *req = ff->reserved_req; | |
227 | struct fuse_release_in *inarg = &req->misc.release.in; | |
228 | ||
229 | spin_lock(&fc->lock); | |
230 | list_del(&ff->write_entry); | |
231 | if (!RB_EMPTY_NODE(&ff->polled_node)) | |
232 | rb_erase(&ff->polled_node, &fc->polled_files); | |
233 | spin_unlock(&fc->lock); | |
234 | ||
235 | wake_up_interruptible_all(&ff->poll_wait); | |
236 | ||
237 | inarg->fh = ff->fh; | |
238 | inarg->flags = flags; | |
239 | req->in.h.opcode = opcode; | |
240 | req->in.h.nodeid = ff->nodeid; | |
241 | req->in.numargs = 1; | |
242 | req->in.args[0].size = sizeof(struct fuse_release_in); | |
243 | req->in.args[0].value = inarg; | |
244 | } | |
245 | ||
246 | void fuse_release_common(struct file *file, int opcode) | |
247 | { | |
248 | struct fuse_file *ff; | |
249 | struct fuse_req *req; | |
250 | ||
251 | ff = file->private_data; | |
252 | if (unlikely(!ff)) | |
253 | return; | |
254 | ||
255 | req = ff->reserved_req; | |
256 | fuse_prepare_release(ff, file->f_flags, opcode); | |
257 | ||
258 | if (ff->flock) { | |
259 | struct fuse_release_in *inarg = &req->misc.release.in; | |
260 | inarg->release_flags |= FUSE_RELEASE_FLOCK_UNLOCK; | |
261 | inarg->lock_owner = fuse_lock_owner_id(ff->fc, | |
262 | (fl_owner_t) file); | |
263 | } | |
264 | /* Hold inode until release is finished */ | |
265 | req->misc.release.inode = igrab(file_inode(file)); | |
266 | ||
267 | /* | |
268 | * Normally this will send the RELEASE request, however if | |
269 | * some asynchronous READ or WRITE requests are outstanding, | |
270 | * the sending will be delayed. | |
271 | * | |
272 | * Make the release synchronous if this is a fuseblk mount, | |
273 | * synchronous RELEASE is allowed (and desirable) in this case | |
274 | * because the server can be trusted not to screw up. | |
275 | */ | |
276 | fuse_file_put(ff, ff->fc->destroy_req != NULL); | |
277 | } | |
278 | ||
279 | static int fuse_open(struct inode *inode, struct file *file) | |
280 | { | |
281 | return fuse_open_common(inode, file, false); | |
282 | } | |
283 | ||
284 | static int fuse_release(struct inode *inode, struct file *file) | |
285 | { | |
286 | struct fuse_conn *fc = get_fuse_conn(inode); | |
287 | ||
288 | /* see fuse_vma_close() for !writeback_cache case */ | |
289 | if (fc->writeback_cache) | |
290 | write_inode_now(inode, 1); | |
291 | ||
292 | fuse_release_common(file, FUSE_RELEASE); | |
293 | ||
294 | /* return value is ignored by VFS */ | |
295 | return 0; | |
296 | } | |
297 | ||
298 | void fuse_sync_release(struct fuse_file *ff, int flags) | |
299 | { | |
300 | WARN_ON(atomic_read(&ff->count) > 1); | |
301 | fuse_prepare_release(ff, flags, FUSE_RELEASE); | |
302 | __set_bit(FR_FORCE, &ff->reserved_req->flags); | |
303 | __clear_bit(FR_BACKGROUND, &ff->reserved_req->flags); | |
304 | fuse_request_send(ff->fc, ff->reserved_req); | |
305 | fuse_put_request(ff->fc, ff->reserved_req); | |
306 | kfree(ff); | |
307 | } | |
308 | EXPORT_SYMBOL_GPL(fuse_sync_release); | |
309 | ||
310 | /* | |
311 | * Scramble the ID space with XTEA, so that the value of the files_struct | |
312 | * pointer is not exposed to userspace. | |
313 | */ | |
314 | u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id) | |
315 | { | |
316 | u32 *k = fc->scramble_key; | |
317 | u64 v = (unsigned long) id; | |
318 | u32 v0 = v; | |
319 | u32 v1 = v >> 32; | |
320 | u32 sum = 0; | |
321 | int i; | |
322 | ||
323 | for (i = 0; i < 32; i++) { | |
324 | v0 += ((v1 << 4 ^ v1 >> 5) + v1) ^ (sum + k[sum & 3]); | |
325 | sum += 0x9E3779B9; | |
326 | v1 += ((v0 << 4 ^ v0 >> 5) + v0) ^ (sum + k[sum>>11 & 3]); | |
327 | } | |
328 | ||
329 | return (u64) v0 + ((u64) v1 << 32); | |
330 | } | |
331 | ||
332 | /* | |
333 | * Check if any page in a range is under writeback | |
334 | * | |
335 | * This is currently done by walking the list of writepage requests | |
336 | * for the inode, which can be pretty inefficient. | |
337 | */ | |
338 | static bool fuse_range_is_writeback(struct inode *inode, pgoff_t idx_from, | |
339 | pgoff_t idx_to) | |
340 | { | |
341 | struct fuse_conn *fc = get_fuse_conn(inode); | |
342 | struct fuse_inode *fi = get_fuse_inode(inode); | |
343 | struct fuse_req *req; | |
344 | bool found = false; | |
345 | ||
346 | spin_lock(&fc->lock); | |
347 | list_for_each_entry(req, &fi->writepages, writepages_entry) { | |
348 | pgoff_t curr_index; | |
349 | ||
350 | BUG_ON(req->inode != inode); | |
351 | curr_index = req->misc.write.in.offset >> PAGE_SHIFT; | |
352 | if (idx_from < curr_index + req->num_pages && | |
353 | curr_index <= idx_to) { | |
354 | found = true; | |
355 | break; | |
356 | } | |
357 | } | |
358 | spin_unlock(&fc->lock); | |
359 | ||
360 | return found; | |
361 | } | |
362 | ||
363 | static inline bool fuse_page_is_writeback(struct inode *inode, pgoff_t index) | |
364 | { | |
365 | return fuse_range_is_writeback(inode, index, index); | |
366 | } | |
367 | ||
368 | /* | |
369 | * Wait for page writeback to be completed. | |
370 | * | |
371 | * Since fuse doesn't rely on the VM writeback tracking, this has to | |
372 | * use some other means. | |
373 | */ | |
374 | static int fuse_wait_on_page_writeback(struct inode *inode, pgoff_t index) | |
375 | { | |
376 | struct fuse_inode *fi = get_fuse_inode(inode); | |
377 | ||
378 | wait_event(fi->page_waitq, !fuse_page_is_writeback(inode, index)); | |
379 | return 0; | |
380 | } | |
381 | ||
382 | /* | |
383 | * Wait for all pending writepages on the inode to finish. | |
384 | * | |
385 | * This is currently done by blocking further writes with FUSE_NOWRITE | |
386 | * and waiting for all sent writes to complete. | |
387 | * | |
388 | * This must be called under i_mutex, otherwise the FUSE_NOWRITE usage | |
389 | * could conflict with truncation. | |
390 | */ | |
391 | static void fuse_sync_writes(struct inode *inode) | |
392 | { | |
393 | fuse_set_nowrite(inode); | |
394 | fuse_release_nowrite(inode); | |
395 | } | |
396 | ||
397 | static int fuse_flush(struct file *file, fl_owner_t id) | |
398 | { | |
399 | struct inode *inode = file_inode(file); | |
400 | struct fuse_conn *fc = get_fuse_conn(inode); | |
401 | struct fuse_file *ff = file->private_data; | |
402 | struct fuse_req *req; | |
403 | struct fuse_flush_in inarg; | |
404 | int err; | |
405 | ||
406 | if (is_bad_inode(inode)) | |
407 | return -EIO; | |
408 | ||
409 | if (fc->no_flush) | |
410 | return 0; | |
411 | ||
412 | err = write_inode_now(inode, 1); | |
413 | if (err) | |
414 | return err; | |
415 | ||
416 | inode_lock(inode); | |
417 | fuse_sync_writes(inode); | |
418 | inode_unlock(inode); | |
419 | ||
420 | err = filemap_check_errors(file->f_mapping); | |
421 | if (err) | |
422 | return err; | |
423 | ||
424 | req = fuse_get_req_nofail_nopages(fc, file); | |
425 | memset(&inarg, 0, sizeof(inarg)); | |
426 | inarg.fh = ff->fh; | |
427 | inarg.lock_owner = fuse_lock_owner_id(fc, id); | |
428 | req->in.h.opcode = FUSE_FLUSH; | |
429 | req->in.h.nodeid = get_node_id(inode); | |
430 | req->in.numargs = 1; | |
431 | req->in.args[0].size = sizeof(inarg); | |
432 | req->in.args[0].value = &inarg; | |
433 | __set_bit(FR_FORCE, &req->flags); | |
434 | fuse_request_send(fc, req); | |
435 | err = req->out.h.error; | |
436 | fuse_put_request(fc, req); | |
437 | if (err == -ENOSYS) { | |
438 | fc->no_flush = 1; | |
439 | err = 0; | |
440 | } | |
441 | return err; | |
442 | } | |
443 | ||
444 | int fuse_fsync_common(struct file *file, loff_t start, loff_t end, | |
445 | int datasync, int isdir) | |
446 | { | |
447 | struct inode *inode = file->f_mapping->host; | |
448 | struct fuse_conn *fc = get_fuse_conn(inode); | |
449 | struct fuse_file *ff = file->private_data; | |
450 | FUSE_ARGS(args); | |
451 | struct fuse_fsync_in inarg; | |
452 | int err; | |
453 | ||
454 | if (is_bad_inode(inode)) | |
455 | return -EIO; | |
456 | ||
457 | inode_lock(inode); | |
458 | ||
459 | /* | |
460 | * Start writeback against all dirty pages of the inode, then | |
461 | * wait for all outstanding writes, before sending the FSYNC | |
462 | * request. | |
463 | */ | |
464 | err = filemap_write_and_wait_range(inode->i_mapping, start, end); | |
465 | if (err) | |
466 | goto out; | |
467 | ||
468 | fuse_sync_writes(inode); | |
469 | ||
470 | /* | |
471 | * Due to implementation of fuse writeback | |
472 | * filemap_write_and_wait_range() does not catch errors. | |
473 | * We have to do this directly after fuse_sync_writes() | |
474 | */ | |
475 | err = filemap_check_errors(file->f_mapping); | |
476 | if (err) | |
477 | goto out; | |
478 | ||
479 | err = sync_inode_metadata(inode, 1); | |
480 | if (err) | |
481 | goto out; | |
482 | ||
483 | if ((!isdir && fc->no_fsync) || (isdir && fc->no_fsyncdir)) | |
484 | goto out; | |
485 | ||
486 | memset(&inarg, 0, sizeof(inarg)); | |
487 | inarg.fh = ff->fh; | |
488 | inarg.fsync_flags = datasync ? 1 : 0; | |
489 | args.in.h.opcode = isdir ? FUSE_FSYNCDIR : FUSE_FSYNC; | |
490 | args.in.h.nodeid = get_node_id(inode); | |
491 | args.in.numargs = 1; | |
492 | args.in.args[0].size = sizeof(inarg); | |
493 | args.in.args[0].value = &inarg; | |
494 | err = fuse_simple_request(fc, &args); | |
495 | if (err == -ENOSYS) { | |
496 | if (isdir) | |
497 | fc->no_fsyncdir = 1; | |
498 | else | |
499 | fc->no_fsync = 1; | |
500 | err = 0; | |
501 | } | |
502 | out: | |
503 | inode_unlock(inode); | |
504 | return err; | |
505 | } | |
506 | ||
507 | static int fuse_fsync(struct file *file, loff_t start, loff_t end, | |
508 | int datasync) | |
509 | { | |
510 | return fuse_fsync_common(file, start, end, datasync, 0); | |
511 | } | |
512 | ||
513 | void fuse_read_fill(struct fuse_req *req, struct file *file, loff_t pos, | |
514 | size_t count, int opcode) | |
515 | { | |
516 | struct fuse_read_in *inarg = &req->misc.read.in; | |
517 | struct fuse_file *ff = file->private_data; | |
518 | ||
519 | inarg->fh = ff->fh; | |
520 | inarg->offset = pos; | |
521 | inarg->size = count; | |
522 | inarg->flags = file->f_flags; | |
523 | req->in.h.opcode = opcode; | |
524 | req->in.h.nodeid = ff->nodeid; | |
525 | req->in.numargs = 1; | |
526 | req->in.args[0].size = sizeof(struct fuse_read_in); | |
527 | req->in.args[0].value = inarg; | |
528 | req->out.argvar = 1; | |
529 | req->out.numargs = 1; | |
530 | req->out.args[0].size = count; | |
531 | } | |
532 | ||
533 | static void fuse_release_user_pages(struct fuse_req *req, bool should_dirty) | |
534 | { | |
535 | unsigned i; | |
536 | ||
537 | for (i = 0; i < req->num_pages; i++) { | |
538 | struct page *page = req->pages[i]; | |
539 | if (should_dirty) | |
540 | set_page_dirty_lock(page); | |
541 | put_page(page); | |
542 | } | |
543 | } | |
544 | ||
545 | static void fuse_io_release(struct kref *kref) | |
546 | { | |
547 | kfree(container_of(kref, struct fuse_io_priv, refcnt)); | |
548 | } | |
549 | ||
550 | static ssize_t fuse_get_res_by_io(struct fuse_io_priv *io) | |
551 | { | |
552 | if (io->err) | |
553 | return io->err; | |
554 | ||
555 | if (io->bytes >= 0 && io->write) | |
556 | return -EIO; | |
557 | ||
558 | return io->bytes < 0 ? io->size : io->bytes; | |
559 | } | |
560 | ||
561 | /** | |
562 | * In case of short read, the caller sets 'pos' to the position of | |
563 | * actual end of fuse request in IO request. Otherwise, if bytes_requested | |
564 | * == bytes_transferred or rw == WRITE, the caller sets 'pos' to -1. | |
565 | * | |
566 | * An example: | |
567 | * User requested DIO read of 64K. It was splitted into two 32K fuse requests, | |
568 | * both submitted asynchronously. The first of them was ACKed by userspace as | |
569 | * fully completed (req->out.args[0].size == 32K) resulting in pos == -1. The | |
570 | * second request was ACKed as short, e.g. only 1K was read, resulting in | |
571 | * pos == 33K. | |
572 | * | |
573 | * Thus, when all fuse requests are completed, the minimal non-negative 'pos' | |
574 | * will be equal to the length of the longest contiguous fragment of | |
575 | * transferred data starting from the beginning of IO request. | |
576 | */ | |
577 | static void fuse_aio_complete(struct fuse_io_priv *io, int err, ssize_t pos) | |
578 | { | |
579 | int left; | |
580 | ||
581 | spin_lock(&io->lock); | |
582 | if (err) | |
583 | io->err = io->err ? : err; | |
584 | else if (pos >= 0 && (io->bytes < 0 || pos < io->bytes)) | |
585 | io->bytes = pos; | |
586 | ||
587 | left = --io->reqs; | |
588 | if (!left && io->blocking) | |
589 | complete(io->done); | |
590 | spin_unlock(&io->lock); | |
591 | ||
592 | if (!left && !io->blocking) { | |
593 | ssize_t res = fuse_get_res_by_io(io); | |
594 | ||
595 | if (res >= 0) { | |
596 | struct inode *inode = file_inode(io->iocb->ki_filp); | |
597 | struct fuse_conn *fc = get_fuse_conn(inode); | |
598 | struct fuse_inode *fi = get_fuse_inode(inode); | |
599 | ||
600 | spin_lock(&fc->lock); | |
601 | fi->attr_version = ++fc->attr_version; | |
602 | spin_unlock(&fc->lock); | |
603 | } | |
604 | ||
605 | io->iocb->ki_complete(io->iocb, res, 0); | |
606 | } | |
607 | ||
608 | kref_put(&io->refcnt, fuse_io_release); | |
609 | } | |
610 | ||
611 | static void fuse_aio_complete_req(struct fuse_conn *fc, struct fuse_req *req) | |
612 | { | |
613 | struct fuse_io_priv *io = req->io; | |
614 | ssize_t pos = -1; | |
615 | ||
616 | fuse_release_user_pages(req, !io->write); | |
617 | ||
618 | if (io->write) { | |
619 | if (req->misc.write.in.size != req->misc.write.out.size) | |
620 | pos = req->misc.write.in.offset - io->offset + | |
621 | req->misc.write.out.size; | |
622 | } else { | |
623 | if (req->misc.read.in.size != req->out.args[0].size) | |
624 | pos = req->misc.read.in.offset - io->offset + | |
625 | req->out.args[0].size; | |
626 | } | |
627 | ||
628 | fuse_aio_complete(io, req->out.h.error, pos); | |
629 | } | |
630 | ||
631 | static size_t fuse_async_req_send(struct fuse_conn *fc, struct fuse_req *req, | |
632 | size_t num_bytes, struct fuse_io_priv *io) | |
633 | { | |
634 | spin_lock(&io->lock); | |
635 | kref_get(&io->refcnt); | |
636 | io->size += num_bytes; | |
637 | io->reqs++; | |
638 | spin_unlock(&io->lock); | |
639 | ||
640 | req->io = io; | |
641 | req->end = fuse_aio_complete_req; | |
642 | ||
643 | __fuse_get_request(req); | |
644 | fuse_request_send_background(fc, req); | |
645 | ||
646 | return num_bytes; | |
647 | } | |
648 | ||
649 | static size_t fuse_send_read(struct fuse_req *req, struct fuse_io_priv *io, | |
650 | loff_t pos, size_t count, fl_owner_t owner) | |
651 | { | |
652 | struct file *file = io->file; | |
653 | struct fuse_file *ff = file->private_data; | |
654 | struct fuse_conn *fc = ff->fc; | |
655 | ||
656 | fuse_read_fill(req, file, pos, count, FUSE_READ); | |
657 | if (owner != NULL) { | |
658 | struct fuse_read_in *inarg = &req->misc.read.in; | |
659 | ||
660 | inarg->read_flags |= FUSE_READ_LOCKOWNER; | |
661 | inarg->lock_owner = fuse_lock_owner_id(fc, owner); | |
662 | } | |
663 | ||
664 | if (io->async) | |
665 | return fuse_async_req_send(fc, req, count, io); | |
666 | ||
667 | fuse_request_send(fc, req); | |
668 | return req->out.args[0].size; | |
669 | } | |
670 | ||
671 | static void fuse_read_update_size(struct inode *inode, loff_t size, | |
672 | u64 attr_ver) | |
673 | { | |
674 | struct fuse_conn *fc = get_fuse_conn(inode); | |
675 | struct fuse_inode *fi = get_fuse_inode(inode); | |
676 | ||
677 | spin_lock(&fc->lock); | |
678 | if (attr_ver == fi->attr_version && size < inode->i_size && | |
679 | !test_bit(FUSE_I_SIZE_UNSTABLE, &fi->state)) { | |
680 | fi->attr_version = ++fc->attr_version; | |
681 | i_size_write(inode, size); | |
682 | } | |
683 | spin_unlock(&fc->lock); | |
684 | } | |
685 | ||
686 | static void fuse_short_read(struct fuse_req *req, struct inode *inode, | |
687 | u64 attr_ver) | |
688 | { | |
689 | size_t num_read = req->out.args[0].size; | |
690 | struct fuse_conn *fc = get_fuse_conn(inode); | |
691 | ||
692 | if (fc->writeback_cache) { | |
693 | /* | |
694 | * A hole in a file. Some data after the hole are in page cache, | |
695 | * but have not reached the client fs yet. So, the hole is not | |
696 | * present there. | |
697 | */ | |
698 | int i; | |
699 | int start_idx = num_read >> PAGE_SHIFT; | |
700 | size_t off = num_read & (PAGE_SIZE - 1); | |
701 | ||
702 | for (i = start_idx; i < req->num_pages; i++) { | |
703 | zero_user_segment(req->pages[i], off, PAGE_SIZE); | |
704 | off = 0; | |
705 | } | |
706 | } else { | |
707 | loff_t pos = page_offset(req->pages[0]) + num_read; | |
708 | fuse_read_update_size(inode, pos, attr_ver); | |
709 | } | |
710 | } | |
711 | ||
712 | static int fuse_do_readpage(struct file *file, struct page *page) | |
713 | { | |
714 | struct fuse_io_priv io = FUSE_IO_PRIV_SYNC(file); | |
715 | struct inode *inode = page->mapping->host; | |
716 | struct fuse_conn *fc = get_fuse_conn(inode); | |
717 | struct fuse_req *req; | |
718 | size_t num_read; | |
719 | loff_t pos = page_offset(page); | |
720 | size_t count = PAGE_SIZE; | |
721 | u64 attr_ver; | |
722 | int err; | |
723 | ||
724 | /* | |
725 | * Page writeback can extend beyond the lifetime of the | |
726 | * page-cache page, so make sure we read a properly synced | |
727 | * page. | |
728 | */ | |
729 | fuse_wait_on_page_writeback(inode, page->index); | |
730 | ||
731 | req = fuse_get_req(fc, 1); | |
732 | if (IS_ERR(req)) | |
733 | return PTR_ERR(req); | |
734 | ||
735 | attr_ver = fuse_get_attr_version(fc); | |
736 | ||
737 | req->out.page_zeroing = 1; | |
738 | req->out.argpages = 1; | |
739 | req->num_pages = 1; | |
740 | req->pages[0] = page; | |
741 | req->page_descs[0].length = count; | |
742 | num_read = fuse_send_read(req, &io, pos, count, NULL); | |
743 | err = req->out.h.error; | |
744 | ||
745 | if (!err) { | |
746 | /* | |
747 | * Short read means EOF. If file size is larger, truncate it | |
748 | */ | |
749 | if (num_read < count) | |
750 | fuse_short_read(req, inode, attr_ver); | |
751 | ||
752 | SetPageUptodate(page); | |
753 | } | |
754 | ||
755 | fuse_put_request(fc, req); | |
756 | ||
757 | return err; | |
758 | } | |
759 | ||
760 | static int fuse_readpage(struct file *file, struct page *page) | |
761 | { | |
762 | struct inode *inode = page->mapping->host; | |
763 | int err; | |
764 | ||
765 | err = -EIO; | |
766 | if (is_bad_inode(inode)) | |
767 | goto out; | |
768 | ||
769 | err = fuse_do_readpage(file, page); | |
770 | fuse_invalidate_atime(inode); | |
771 | out: | |
772 | unlock_page(page); | |
773 | return err; | |
774 | } | |
775 | ||
776 | static void fuse_readpages_end(struct fuse_conn *fc, struct fuse_req *req) | |
777 | { | |
778 | int i; | |
779 | size_t count = req->misc.read.in.size; | |
780 | size_t num_read = req->out.args[0].size; | |
781 | struct address_space *mapping = NULL; | |
782 | ||
783 | for (i = 0; mapping == NULL && i < req->num_pages; i++) | |
784 | mapping = req->pages[i]->mapping; | |
785 | ||
786 | if (mapping) { | |
787 | struct inode *inode = mapping->host; | |
788 | ||
789 | /* | |
790 | * Short read means EOF. If file size is larger, truncate it | |
791 | */ | |
792 | if (!req->out.h.error && num_read < count) | |
793 | fuse_short_read(req, inode, req->misc.read.attr_ver); | |
794 | ||
795 | fuse_invalidate_atime(inode); | |
796 | } | |
797 | ||
798 | for (i = 0; i < req->num_pages; i++) { | |
799 | struct page *page = req->pages[i]; | |
800 | if (!req->out.h.error) | |
801 | SetPageUptodate(page); | |
802 | else | |
803 | SetPageError(page); | |
804 | unlock_page(page); | |
805 | put_page(page); | |
806 | } | |
807 | if (req->ff) | |
808 | fuse_file_put(req->ff, false); | |
809 | } | |
810 | ||
811 | static void fuse_send_readpages(struct fuse_req *req, struct file *file) | |
812 | { | |
813 | struct fuse_file *ff = file->private_data; | |
814 | struct fuse_conn *fc = ff->fc; | |
815 | loff_t pos = page_offset(req->pages[0]); | |
816 | size_t count = req->num_pages << PAGE_SHIFT; | |
817 | ||
818 | req->out.argpages = 1; | |
819 | req->out.page_zeroing = 1; | |
820 | req->out.page_replace = 1; | |
821 | fuse_read_fill(req, file, pos, count, FUSE_READ); | |
822 | req->misc.read.attr_ver = fuse_get_attr_version(fc); | |
823 | if (fc->async_read) { | |
824 | req->ff = fuse_file_get(ff); | |
825 | req->end = fuse_readpages_end; | |
826 | fuse_request_send_background(fc, req); | |
827 | } else { | |
828 | fuse_request_send(fc, req); | |
829 | fuse_readpages_end(fc, req); | |
830 | fuse_put_request(fc, req); | |
831 | } | |
832 | } | |
833 | ||
834 | struct fuse_fill_data { | |
835 | struct fuse_req *req; | |
836 | struct file *file; | |
837 | struct inode *inode; | |
838 | unsigned nr_pages; | |
839 | }; | |
840 | ||
841 | static int fuse_readpages_fill(void *_data, struct page *page) | |
842 | { | |
843 | struct fuse_fill_data *data = _data; | |
844 | struct fuse_req *req = data->req; | |
845 | struct inode *inode = data->inode; | |
846 | struct fuse_conn *fc = get_fuse_conn(inode); | |
847 | ||
848 | fuse_wait_on_page_writeback(inode, page->index); | |
849 | ||
850 | if (req->num_pages && | |
851 | (req->num_pages == FUSE_MAX_PAGES_PER_REQ || | |
852 | (req->num_pages + 1) * PAGE_SIZE > fc->max_read || | |
853 | req->pages[req->num_pages - 1]->index + 1 != page->index)) { | |
854 | int nr_alloc = min_t(unsigned, data->nr_pages, | |
855 | FUSE_MAX_PAGES_PER_REQ); | |
856 | fuse_send_readpages(req, data->file); | |
857 | if (fc->async_read) | |
858 | req = fuse_get_req_for_background(fc, nr_alloc); | |
859 | else | |
860 | req = fuse_get_req(fc, nr_alloc); | |
861 | ||
862 | data->req = req; | |
863 | if (IS_ERR(req)) { | |
864 | unlock_page(page); | |
865 | return PTR_ERR(req); | |
866 | } | |
867 | } | |
868 | ||
869 | if (WARN_ON(req->num_pages >= req->max_pages)) { | |
870 | fuse_put_request(fc, req); | |
871 | return -EIO; | |
872 | } | |
873 | ||
874 | get_page(page); | |
875 | req->pages[req->num_pages] = page; | |
876 | req->page_descs[req->num_pages].length = PAGE_SIZE; | |
877 | req->num_pages++; | |
878 | data->nr_pages--; | |
879 | return 0; | |
880 | } | |
881 | ||
882 | static int fuse_readpages(struct file *file, struct address_space *mapping, | |
883 | struct list_head *pages, unsigned nr_pages) | |
884 | { | |
885 | struct inode *inode = mapping->host; | |
886 | struct fuse_conn *fc = get_fuse_conn(inode); | |
887 | struct fuse_fill_data data; | |
888 | int err; | |
889 | int nr_alloc = min_t(unsigned, nr_pages, FUSE_MAX_PAGES_PER_REQ); | |
890 | ||
891 | err = -EIO; | |
892 | if (is_bad_inode(inode)) | |
893 | goto out; | |
894 | ||
895 | data.file = file; | |
896 | data.inode = inode; | |
897 | if (fc->async_read) | |
898 | data.req = fuse_get_req_for_background(fc, nr_alloc); | |
899 | else | |
900 | data.req = fuse_get_req(fc, nr_alloc); | |
901 | data.nr_pages = nr_pages; | |
902 | err = PTR_ERR(data.req); | |
903 | if (IS_ERR(data.req)) | |
904 | goto out; | |
905 | ||
906 | err = read_cache_pages(mapping, pages, fuse_readpages_fill, &data); | |
907 | if (!err) { | |
908 | if (data.req->num_pages) | |
909 | fuse_send_readpages(data.req, file); | |
910 | else | |
911 | fuse_put_request(fc, data.req); | |
912 | } | |
913 | out: | |
914 | return err; | |
915 | } | |
916 | ||
917 | static ssize_t fuse_file_read_iter(struct kiocb *iocb, struct iov_iter *to) | |
918 | { | |
919 | struct inode *inode = iocb->ki_filp->f_mapping->host; | |
920 | struct fuse_conn *fc = get_fuse_conn(inode); | |
921 | ||
922 | /* | |
923 | * In auto invalidate mode, always update attributes on read. | |
924 | * Otherwise, only update if we attempt to read past EOF (to ensure | |
925 | * i_size is up to date). | |
926 | */ | |
927 | if (fc->auto_inval_data || | |
928 | (iocb->ki_pos + iov_iter_count(to) > i_size_read(inode))) { | |
929 | int err; | |
930 | err = fuse_update_attributes(inode, NULL, iocb->ki_filp, NULL); | |
931 | if (err) | |
932 | return err; | |
933 | } | |
934 | ||
935 | return generic_file_read_iter(iocb, to); | |
936 | } | |
937 | ||
938 | static void fuse_write_fill(struct fuse_req *req, struct fuse_file *ff, | |
939 | loff_t pos, size_t count) | |
940 | { | |
941 | struct fuse_write_in *inarg = &req->misc.write.in; | |
942 | struct fuse_write_out *outarg = &req->misc.write.out; | |
943 | ||
944 | inarg->fh = ff->fh; | |
945 | inarg->offset = pos; | |
946 | inarg->size = count; | |
947 | req->in.h.opcode = FUSE_WRITE; | |
948 | req->in.h.nodeid = ff->nodeid; | |
949 | req->in.numargs = 2; | |
950 | if (ff->fc->minor < 9) | |
951 | req->in.args[0].size = FUSE_COMPAT_WRITE_IN_SIZE; | |
952 | else | |
953 | req->in.args[0].size = sizeof(struct fuse_write_in); | |
954 | req->in.args[0].value = inarg; | |
955 | req->in.args[1].size = count; | |
956 | req->out.numargs = 1; | |
957 | req->out.args[0].size = sizeof(struct fuse_write_out); | |
958 | req->out.args[0].value = outarg; | |
959 | } | |
960 | ||
961 | static size_t fuse_send_write(struct fuse_req *req, struct fuse_io_priv *io, | |
962 | loff_t pos, size_t count, fl_owner_t owner) | |
963 | { | |
964 | struct file *file = io->file; | |
965 | struct fuse_file *ff = file->private_data; | |
966 | struct fuse_conn *fc = ff->fc; | |
967 | struct fuse_write_in *inarg = &req->misc.write.in; | |
968 | ||
969 | fuse_write_fill(req, ff, pos, count); | |
970 | inarg->flags = file->f_flags; | |
971 | if (owner != NULL) { | |
972 | inarg->write_flags |= FUSE_WRITE_LOCKOWNER; | |
973 | inarg->lock_owner = fuse_lock_owner_id(fc, owner); | |
974 | } | |
975 | ||
976 | if (io->async) | |
977 | return fuse_async_req_send(fc, req, count, io); | |
978 | ||
979 | fuse_request_send(fc, req); | |
980 | return req->misc.write.out.size; | |
981 | } | |
982 | ||
983 | bool fuse_write_update_size(struct inode *inode, loff_t pos) | |
984 | { | |
985 | struct fuse_conn *fc = get_fuse_conn(inode); | |
986 | struct fuse_inode *fi = get_fuse_inode(inode); | |
987 | bool ret = false; | |
988 | ||
989 | spin_lock(&fc->lock); | |
990 | fi->attr_version = ++fc->attr_version; | |
991 | if (pos > inode->i_size) { | |
992 | i_size_write(inode, pos); | |
993 | ret = true; | |
994 | } | |
995 | spin_unlock(&fc->lock); | |
996 | ||
997 | return ret; | |
998 | } | |
999 | ||
1000 | static size_t fuse_send_write_pages(struct fuse_req *req, struct file *file, | |
1001 | struct inode *inode, loff_t pos, | |
1002 | size_t count) | |
1003 | { | |
1004 | size_t res; | |
1005 | unsigned offset; | |
1006 | unsigned i; | |
1007 | struct fuse_io_priv io = FUSE_IO_PRIV_SYNC(file); | |
1008 | ||
1009 | for (i = 0; i < req->num_pages; i++) | |
1010 | fuse_wait_on_page_writeback(inode, req->pages[i]->index); | |
1011 | ||
1012 | res = fuse_send_write(req, &io, pos, count, NULL); | |
1013 | ||
1014 | offset = req->page_descs[0].offset; | |
1015 | count = res; | |
1016 | for (i = 0; i < req->num_pages; i++) { | |
1017 | struct page *page = req->pages[i]; | |
1018 | ||
1019 | if (!req->out.h.error && !offset && count >= PAGE_SIZE) | |
1020 | SetPageUptodate(page); | |
1021 | ||
1022 | if (count > PAGE_SIZE - offset) | |
1023 | count -= PAGE_SIZE - offset; | |
1024 | else | |
1025 | count = 0; | |
1026 | offset = 0; | |
1027 | ||
1028 | unlock_page(page); | |
1029 | put_page(page); | |
1030 | } | |
1031 | ||
1032 | return res; | |
1033 | } | |
1034 | ||
1035 | static ssize_t fuse_fill_write_pages(struct fuse_req *req, | |
1036 | struct address_space *mapping, | |
1037 | struct iov_iter *ii, loff_t pos) | |
1038 | { | |
1039 | struct fuse_conn *fc = get_fuse_conn(mapping->host); | |
1040 | unsigned offset = pos & (PAGE_SIZE - 1); | |
1041 | size_t count = 0; | |
1042 | int err; | |
1043 | ||
1044 | req->in.argpages = 1; | |
1045 | req->page_descs[0].offset = offset; | |
1046 | ||
1047 | do { | |
1048 | size_t tmp; | |
1049 | struct page *page; | |
1050 | pgoff_t index = pos >> PAGE_SHIFT; | |
1051 | size_t bytes = min_t(size_t, PAGE_SIZE - offset, | |
1052 | iov_iter_count(ii)); | |
1053 | ||
1054 | bytes = min_t(size_t, bytes, fc->max_write - count); | |
1055 | ||
1056 | again: | |
1057 | err = -EFAULT; | |
1058 | if (iov_iter_fault_in_readable(ii, bytes)) | |
1059 | break; | |
1060 | ||
1061 | err = -ENOMEM; | |
1062 | page = grab_cache_page_write_begin(mapping, index, 0); | |
1063 | if (!page) | |
1064 | break; | |
1065 | ||
1066 | if (mapping_writably_mapped(mapping)) | |
1067 | flush_dcache_page(page); | |
1068 | ||
1069 | tmp = iov_iter_copy_from_user_atomic(page, ii, offset, bytes); | |
1070 | flush_dcache_page(page); | |
1071 | ||
1072 | iov_iter_advance(ii, tmp); | |
1073 | if (!tmp) { | |
1074 | unlock_page(page); | |
1075 | put_page(page); | |
1076 | bytes = min(bytes, iov_iter_single_seg_count(ii)); | |
1077 | goto again; | |
1078 | } | |
1079 | ||
1080 | err = 0; | |
1081 | req->pages[req->num_pages] = page; | |
1082 | req->page_descs[req->num_pages].length = tmp; | |
1083 | req->num_pages++; | |
1084 | ||
1085 | count += tmp; | |
1086 | pos += tmp; | |
1087 | offset += tmp; | |
1088 | if (offset == PAGE_SIZE) | |
1089 | offset = 0; | |
1090 | ||
1091 | if (!fc->big_writes) | |
1092 | break; | |
1093 | } while (iov_iter_count(ii) && count < fc->max_write && | |
1094 | req->num_pages < req->max_pages && offset == 0); | |
1095 | ||
1096 | return count > 0 ? count : err; | |
1097 | } | |
1098 | ||
1099 | static inline unsigned fuse_wr_pages(loff_t pos, size_t len) | |
1100 | { | |
1101 | return min_t(unsigned, | |
1102 | ((pos + len - 1) >> PAGE_SHIFT) - | |
1103 | (pos >> PAGE_SHIFT) + 1, | |
1104 | FUSE_MAX_PAGES_PER_REQ); | |
1105 | } | |
1106 | ||
1107 | static ssize_t fuse_perform_write(struct file *file, | |
1108 | struct address_space *mapping, | |
1109 | struct iov_iter *ii, loff_t pos) | |
1110 | { | |
1111 | struct inode *inode = mapping->host; | |
1112 | struct fuse_conn *fc = get_fuse_conn(inode); | |
1113 | struct fuse_inode *fi = get_fuse_inode(inode); | |
1114 | int err = 0; | |
1115 | ssize_t res = 0; | |
1116 | ||
1117 | if (is_bad_inode(inode)) | |
1118 | return -EIO; | |
1119 | ||
1120 | if (inode->i_size < pos + iov_iter_count(ii)) | |
1121 | set_bit(FUSE_I_SIZE_UNSTABLE, &fi->state); | |
1122 | ||
1123 | do { | |
1124 | struct fuse_req *req; | |
1125 | ssize_t count; | |
1126 | unsigned nr_pages = fuse_wr_pages(pos, iov_iter_count(ii)); | |
1127 | ||
1128 | req = fuse_get_req(fc, nr_pages); | |
1129 | if (IS_ERR(req)) { | |
1130 | err = PTR_ERR(req); | |
1131 | break; | |
1132 | } | |
1133 | ||
1134 | count = fuse_fill_write_pages(req, mapping, ii, pos); | |
1135 | if (count <= 0) { | |
1136 | err = count; | |
1137 | } else { | |
1138 | size_t num_written; | |
1139 | ||
1140 | num_written = fuse_send_write_pages(req, file, inode, | |
1141 | pos, count); | |
1142 | err = req->out.h.error; | |
1143 | if (!err) { | |
1144 | res += num_written; | |
1145 | pos += num_written; | |
1146 | ||
1147 | /* break out of the loop on short write */ | |
1148 | if (num_written != count) | |
1149 | err = -EIO; | |
1150 | } | |
1151 | } | |
1152 | fuse_put_request(fc, req); | |
1153 | } while (!err && iov_iter_count(ii)); | |
1154 | ||
1155 | if (res > 0) | |
1156 | fuse_write_update_size(inode, pos); | |
1157 | ||
1158 | clear_bit(FUSE_I_SIZE_UNSTABLE, &fi->state); | |
1159 | fuse_invalidate_attr(inode); | |
1160 | ||
1161 | return res > 0 ? res : err; | |
1162 | } | |
1163 | ||
1164 | static ssize_t fuse_file_write_iter(struct kiocb *iocb, struct iov_iter *from) | |
1165 | { | |
1166 | struct file *file = iocb->ki_filp; | |
1167 | struct address_space *mapping = file->f_mapping; | |
1168 | ssize_t written = 0; | |
1169 | ssize_t written_buffered = 0; | |
1170 | struct inode *inode = mapping->host; | |
1171 | ssize_t err; | |
1172 | loff_t endbyte = 0; | |
1173 | ||
1174 | if (get_fuse_conn(inode)->writeback_cache) { | |
1175 | /* Update size (EOF optimization) and mode (SUID clearing) */ | |
1176 | err = fuse_update_attributes(mapping->host, NULL, file, NULL); | |
1177 | if (err) | |
1178 | return err; | |
1179 | ||
1180 | return generic_file_write_iter(iocb, from); | |
1181 | } | |
1182 | ||
1183 | inode_lock(inode); | |
1184 | ||
1185 | /* We can write back this queue in page reclaim */ | |
1186 | current->backing_dev_info = inode_to_bdi(inode); | |
1187 | ||
1188 | err = generic_write_checks(iocb, from); | |
1189 | if (err <= 0) | |
1190 | goto out; | |
1191 | ||
1192 | err = file_remove_privs(file); | |
1193 | if (err) | |
1194 | goto out; | |
1195 | ||
1196 | err = file_update_time(file); | |
1197 | if (err) | |
1198 | goto out; | |
1199 | ||
1200 | if (iocb->ki_flags & IOCB_DIRECT) { | |
1201 | loff_t pos = iocb->ki_pos; | |
1202 | written = generic_file_direct_write(iocb, from); | |
1203 | if (written < 0 || !iov_iter_count(from)) | |
1204 | goto out; | |
1205 | ||
1206 | pos += written; | |
1207 | ||
1208 | written_buffered = fuse_perform_write(file, mapping, from, pos); | |
1209 | if (written_buffered < 0) { | |
1210 | err = written_buffered; | |
1211 | goto out; | |
1212 | } | |
1213 | endbyte = pos + written_buffered - 1; | |
1214 | ||
1215 | err = filemap_write_and_wait_range(file->f_mapping, pos, | |
1216 | endbyte); | |
1217 | if (err) | |
1218 | goto out; | |
1219 | ||
1220 | invalidate_mapping_pages(file->f_mapping, | |
1221 | pos >> PAGE_SHIFT, | |
1222 | endbyte >> PAGE_SHIFT); | |
1223 | ||
1224 | written += written_buffered; | |
1225 | iocb->ki_pos = pos + written_buffered; | |
1226 | } else { | |
1227 | written = fuse_perform_write(file, mapping, from, iocb->ki_pos); | |
1228 | if (written >= 0) | |
1229 | iocb->ki_pos += written; | |
1230 | } | |
1231 | out: | |
1232 | current->backing_dev_info = NULL; | |
1233 | inode_unlock(inode); | |
1234 | ||
1235 | return written ? written : err; | |
1236 | } | |
1237 | ||
1238 | static inline void fuse_page_descs_length_init(struct fuse_req *req, | |
1239 | unsigned index, unsigned nr_pages) | |
1240 | { | |
1241 | int i; | |
1242 | ||
1243 | for (i = index; i < index + nr_pages; i++) | |
1244 | req->page_descs[i].length = PAGE_SIZE - | |
1245 | req->page_descs[i].offset; | |
1246 | } | |
1247 | ||
1248 | static inline unsigned long fuse_get_user_addr(const struct iov_iter *ii) | |
1249 | { | |
1250 | return (unsigned long)ii->iov->iov_base + ii->iov_offset; | |
1251 | } | |
1252 | ||
1253 | static inline size_t fuse_get_frag_size(const struct iov_iter *ii, | |
1254 | size_t max_size) | |
1255 | { | |
1256 | return min(iov_iter_single_seg_count(ii), max_size); | |
1257 | } | |
1258 | ||
1259 | static int fuse_get_user_pages(struct fuse_req *req, struct iov_iter *ii, | |
1260 | size_t *nbytesp, int write) | |
1261 | { | |
1262 | size_t nbytes = 0; /* # bytes already packed in req */ | |
1263 | ssize_t ret = 0; | |
1264 | ||
1265 | /* Special case for kernel I/O: can copy directly into the buffer */ | |
1266 | if (ii->type & ITER_KVEC) { | |
1267 | unsigned long user_addr = fuse_get_user_addr(ii); | |
1268 | size_t frag_size = fuse_get_frag_size(ii, *nbytesp); | |
1269 | ||
1270 | if (write) | |
1271 | req->in.args[1].value = (void *) user_addr; | |
1272 | else | |
1273 | req->out.args[0].value = (void *) user_addr; | |
1274 | ||
1275 | iov_iter_advance(ii, frag_size); | |
1276 | *nbytesp = frag_size; | |
1277 | return 0; | |
1278 | } | |
1279 | ||
1280 | while (nbytes < *nbytesp && req->num_pages < req->max_pages) { | |
1281 | unsigned npages; | |
1282 | size_t start; | |
1283 | ret = iov_iter_get_pages(ii, &req->pages[req->num_pages], | |
1284 | *nbytesp - nbytes, | |
1285 | req->max_pages - req->num_pages, | |
1286 | &start); | |
1287 | if (ret < 0) | |
1288 | break; | |
1289 | ||
1290 | iov_iter_advance(ii, ret); | |
1291 | nbytes += ret; | |
1292 | ||
1293 | ret += start; | |
1294 | npages = (ret + PAGE_SIZE - 1) / PAGE_SIZE; | |
1295 | ||
1296 | req->page_descs[req->num_pages].offset = start; | |
1297 | fuse_page_descs_length_init(req, req->num_pages, npages); | |
1298 | ||
1299 | req->num_pages += npages; | |
1300 | req->page_descs[req->num_pages - 1].length -= | |
1301 | (PAGE_SIZE - ret) & (PAGE_SIZE - 1); | |
1302 | } | |
1303 | ||
1304 | if (write) | |
1305 | req->in.argpages = 1; | |
1306 | else | |
1307 | req->out.argpages = 1; | |
1308 | ||
1309 | *nbytesp = nbytes; | |
1310 | ||
1311 | return ret < 0 ? ret : 0; | |
1312 | } | |
1313 | ||
1314 | static inline int fuse_iter_npages(const struct iov_iter *ii_p) | |
1315 | { | |
1316 | return iov_iter_npages(ii_p, FUSE_MAX_PAGES_PER_REQ); | |
1317 | } | |
1318 | ||
1319 | ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter, | |
1320 | loff_t *ppos, int flags) | |
1321 | { | |
1322 | int write = flags & FUSE_DIO_WRITE; | |
1323 | bool should_dirty = !write && iter_is_iovec(iter); | |
1324 | int cuse = flags & FUSE_DIO_CUSE; | |
1325 | struct file *file = io->file; | |
1326 | struct inode *inode = file->f_mapping->host; | |
1327 | struct fuse_file *ff = file->private_data; | |
1328 | struct fuse_conn *fc = ff->fc; | |
1329 | size_t nmax = write ? fc->max_write : fc->max_read; | |
1330 | loff_t pos = *ppos; | |
1331 | size_t count = iov_iter_count(iter); | |
1332 | pgoff_t idx_from = pos >> PAGE_SHIFT; | |
1333 | pgoff_t idx_to = (pos + count - 1) >> PAGE_SHIFT; | |
1334 | ssize_t res = 0; | |
1335 | struct fuse_req *req; | |
1336 | int err = 0; | |
1337 | ||
1338 | if (io->async) | |
1339 | req = fuse_get_req_for_background(fc, fuse_iter_npages(iter)); | |
1340 | else | |
1341 | req = fuse_get_req(fc, fuse_iter_npages(iter)); | |
1342 | if (IS_ERR(req)) | |
1343 | return PTR_ERR(req); | |
1344 | ||
1345 | if (!cuse && fuse_range_is_writeback(inode, idx_from, idx_to)) { | |
1346 | if (!write) | |
1347 | inode_lock(inode); | |
1348 | fuse_sync_writes(inode); | |
1349 | if (!write) | |
1350 | inode_unlock(inode); | |
1351 | } | |
1352 | ||
1353 | while (count) { | |
1354 | size_t nres; | |
1355 | fl_owner_t owner = current->files; | |
1356 | size_t nbytes = min(count, nmax); | |
1357 | err = fuse_get_user_pages(req, iter, &nbytes, write); | |
1358 | if (err && !nbytes) | |
1359 | break; | |
1360 | ||
1361 | if (write) | |
1362 | nres = fuse_send_write(req, io, pos, nbytes, owner); | |
1363 | else | |
1364 | nres = fuse_send_read(req, io, pos, nbytes, owner); | |
1365 | ||
1366 | if (!io->async) | |
1367 | fuse_release_user_pages(req, should_dirty); | |
1368 | if (req->out.h.error) { | |
1369 | err = req->out.h.error; | |
1370 | break; | |
1371 | } else if (nres > nbytes) { | |
1372 | res = 0; | |
1373 | err = -EIO; | |
1374 | break; | |
1375 | } | |
1376 | count -= nres; | |
1377 | res += nres; | |
1378 | pos += nres; | |
1379 | if (nres != nbytes) | |
1380 | break; | |
1381 | if (count) { | |
1382 | fuse_put_request(fc, req); | |
1383 | if (io->async) | |
1384 | req = fuse_get_req_for_background(fc, | |
1385 | fuse_iter_npages(iter)); | |
1386 | else | |
1387 | req = fuse_get_req(fc, fuse_iter_npages(iter)); | |
1388 | if (IS_ERR(req)) | |
1389 | break; | |
1390 | } | |
1391 | } | |
1392 | if (!IS_ERR(req)) | |
1393 | fuse_put_request(fc, req); | |
1394 | if (res > 0) | |
1395 | *ppos = pos; | |
1396 | ||
1397 | return res > 0 ? res : err; | |
1398 | } | |
1399 | EXPORT_SYMBOL_GPL(fuse_direct_io); | |
1400 | ||
1401 | static ssize_t __fuse_direct_read(struct fuse_io_priv *io, | |
1402 | struct iov_iter *iter, | |
1403 | loff_t *ppos) | |
1404 | { | |
1405 | ssize_t res; | |
1406 | struct file *file = io->file; | |
1407 | struct inode *inode = file_inode(file); | |
1408 | ||
1409 | if (is_bad_inode(inode)) | |
1410 | return -EIO; | |
1411 | ||
1412 | res = fuse_direct_io(io, iter, ppos, 0); | |
1413 | ||
1414 | fuse_invalidate_attr(inode); | |
1415 | ||
1416 | return res; | |
1417 | } | |
1418 | ||
1419 | static ssize_t fuse_direct_read_iter(struct kiocb *iocb, struct iov_iter *to) | |
1420 | { | |
1421 | struct fuse_io_priv io = FUSE_IO_PRIV_SYNC(iocb->ki_filp); | |
1422 | return __fuse_direct_read(&io, to, &iocb->ki_pos); | |
1423 | } | |
1424 | ||
1425 | static ssize_t fuse_direct_write_iter(struct kiocb *iocb, struct iov_iter *from) | |
1426 | { | |
1427 | struct file *file = iocb->ki_filp; | |
1428 | struct inode *inode = file_inode(file); | |
1429 | struct fuse_io_priv io = FUSE_IO_PRIV_SYNC(file); | |
1430 | ssize_t res; | |
1431 | ||
1432 | if (is_bad_inode(inode)) | |
1433 | return -EIO; | |
1434 | ||
1435 | /* Don't allow parallel writes to the same file */ | |
1436 | inode_lock(inode); | |
1437 | res = generic_write_checks(iocb, from); | |
1438 | if (res > 0) | |
1439 | res = fuse_direct_io(&io, from, &iocb->ki_pos, FUSE_DIO_WRITE); | |
1440 | fuse_invalidate_attr(inode); | |
1441 | if (res > 0) | |
1442 | fuse_write_update_size(inode, iocb->ki_pos); | |
1443 | inode_unlock(inode); | |
1444 | ||
1445 | return res; | |
1446 | } | |
1447 | ||
1448 | static void fuse_writepage_free(struct fuse_conn *fc, struct fuse_req *req) | |
1449 | { | |
1450 | int i; | |
1451 | ||
1452 | for (i = 0; i < req->num_pages; i++) | |
1453 | __free_page(req->pages[i]); | |
1454 | ||
1455 | if (req->ff) | |
1456 | fuse_file_put(req->ff, false); | |
1457 | } | |
1458 | ||
1459 | static void fuse_writepage_finish(struct fuse_conn *fc, struct fuse_req *req) | |
1460 | { | |
1461 | struct inode *inode = req->inode; | |
1462 | struct fuse_inode *fi = get_fuse_inode(inode); | |
1463 | struct backing_dev_info *bdi = inode_to_bdi(inode); | |
1464 | int i; | |
1465 | ||
1466 | list_del(&req->writepages_entry); | |
1467 | for (i = 0; i < req->num_pages; i++) { | |
1468 | dec_wb_stat(&bdi->wb, WB_WRITEBACK); | |
1469 | dec_node_page_state(req->pages[i], NR_WRITEBACK_TEMP); | |
1470 | wb_writeout_inc(&bdi->wb); | |
1471 | } | |
1472 | wake_up(&fi->page_waitq); | |
1473 | } | |
1474 | ||
1475 | /* Called under fc->lock, may release and reacquire it */ | |
1476 | static void fuse_send_writepage(struct fuse_conn *fc, struct fuse_req *req, | |
1477 | loff_t size) | |
1478 | __releases(fc->lock) | |
1479 | __acquires(fc->lock) | |
1480 | { | |
1481 | struct fuse_inode *fi = get_fuse_inode(req->inode); | |
1482 | struct fuse_write_in *inarg = &req->misc.write.in; | |
1483 | __u64 data_size = req->num_pages * PAGE_SIZE; | |
1484 | ||
1485 | if (!fc->connected) | |
1486 | goto out_free; | |
1487 | ||
1488 | if (inarg->offset + data_size <= size) { | |
1489 | inarg->size = data_size; | |
1490 | } else if (inarg->offset < size) { | |
1491 | inarg->size = size - inarg->offset; | |
1492 | } else { | |
1493 | /* Got truncated off completely */ | |
1494 | goto out_free; | |
1495 | } | |
1496 | ||
1497 | req->in.args[1].size = inarg->size; | |
1498 | fi->writectr++; | |
1499 | fuse_request_send_background_locked(fc, req); | |
1500 | return; | |
1501 | ||
1502 | out_free: | |
1503 | fuse_writepage_finish(fc, req); | |
1504 | spin_unlock(&fc->lock); | |
1505 | fuse_writepage_free(fc, req); | |
1506 | fuse_put_request(fc, req); | |
1507 | spin_lock(&fc->lock); | |
1508 | } | |
1509 | ||
1510 | /* | |
1511 | * If fi->writectr is positive (no truncate or fsync going on) send | |
1512 | * all queued writepage requests. | |
1513 | * | |
1514 | * Called with fc->lock | |
1515 | */ | |
1516 | void fuse_flush_writepages(struct inode *inode) | |
1517 | __releases(fc->lock) | |
1518 | __acquires(fc->lock) | |
1519 | { | |
1520 | struct fuse_conn *fc = get_fuse_conn(inode); | |
1521 | struct fuse_inode *fi = get_fuse_inode(inode); | |
1522 | size_t crop = i_size_read(inode); | |
1523 | struct fuse_req *req; | |
1524 | ||
1525 | while (fi->writectr >= 0 && !list_empty(&fi->queued_writes)) { | |
1526 | req = list_entry(fi->queued_writes.next, struct fuse_req, list); | |
1527 | list_del_init(&req->list); | |
1528 | fuse_send_writepage(fc, req, crop); | |
1529 | } | |
1530 | } | |
1531 | ||
1532 | static void fuse_writepage_end(struct fuse_conn *fc, struct fuse_req *req) | |
1533 | { | |
1534 | struct inode *inode = req->inode; | |
1535 | struct fuse_inode *fi = get_fuse_inode(inode); | |
1536 | ||
1537 | mapping_set_error(inode->i_mapping, req->out.h.error); | |
1538 | spin_lock(&fc->lock); | |
1539 | while (req->misc.write.next) { | |
1540 | struct fuse_conn *fc = get_fuse_conn(inode); | |
1541 | struct fuse_write_in *inarg = &req->misc.write.in; | |
1542 | struct fuse_req *next = req->misc.write.next; | |
1543 | req->misc.write.next = next->misc.write.next; | |
1544 | next->misc.write.next = NULL; | |
1545 | next->ff = fuse_file_get(req->ff); | |
1546 | list_add(&next->writepages_entry, &fi->writepages); | |
1547 | ||
1548 | /* | |
1549 | * Skip fuse_flush_writepages() to make it easy to crop requests | |
1550 | * based on primary request size. | |
1551 | * | |
1552 | * 1st case (trivial): there are no concurrent activities using | |
1553 | * fuse_set/release_nowrite. Then we're on safe side because | |
1554 | * fuse_flush_writepages() would call fuse_send_writepage() | |
1555 | * anyway. | |
1556 | * | |
1557 | * 2nd case: someone called fuse_set_nowrite and it is waiting | |
1558 | * now for completion of all in-flight requests. This happens | |
1559 | * rarely and no more than once per page, so this should be | |
1560 | * okay. | |
1561 | * | |
1562 | * 3rd case: someone (e.g. fuse_do_setattr()) is in the middle | |
1563 | * of fuse_set_nowrite..fuse_release_nowrite section. The fact | |
1564 | * that fuse_set_nowrite returned implies that all in-flight | |
1565 | * requests were completed along with all of their secondary | |
1566 | * requests. Further primary requests are blocked by negative | |
1567 | * writectr. Hence there cannot be any in-flight requests and | |
1568 | * no invocations of fuse_writepage_end() while we're in | |
1569 | * fuse_set_nowrite..fuse_release_nowrite section. | |
1570 | */ | |
1571 | fuse_send_writepage(fc, next, inarg->offset + inarg->size); | |
1572 | } | |
1573 | fi->writectr--; | |
1574 | fuse_writepage_finish(fc, req); | |
1575 | spin_unlock(&fc->lock); | |
1576 | fuse_writepage_free(fc, req); | |
1577 | } | |
1578 | ||
1579 | static struct fuse_file *__fuse_write_file_get(struct fuse_conn *fc, | |
1580 | struct fuse_inode *fi) | |
1581 | { | |
1582 | struct fuse_file *ff = NULL; | |
1583 | ||
1584 | spin_lock(&fc->lock); | |
1585 | if (!list_empty(&fi->write_files)) { | |
1586 | ff = list_entry(fi->write_files.next, struct fuse_file, | |
1587 | write_entry); | |
1588 | fuse_file_get(ff); | |
1589 | } | |
1590 | spin_unlock(&fc->lock); | |
1591 | ||
1592 | return ff; | |
1593 | } | |
1594 | ||
1595 | static struct fuse_file *fuse_write_file_get(struct fuse_conn *fc, | |
1596 | struct fuse_inode *fi) | |
1597 | { | |
1598 | struct fuse_file *ff = __fuse_write_file_get(fc, fi); | |
1599 | WARN_ON(!ff); | |
1600 | return ff; | |
1601 | } | |
1602 | ||
1603 | int fuse_write_inode(struct inode *inode, struct writeback_control *wbc) | |
1604 | { | |
1605 | struct fuse_conn *fc = get_fuse_conn(inode); | |
1606 | struct fuse_inode *fi = get_fuse_inode(inode); | |
1607 | struct fuse_file *ff; | |
1608 | int err; | |
1609 | ||
1610 | ff = __fuse_write_file_get(fc, fi); | |
1611 | err = fuse_flush_times(inode, ff); | |
1612 | if (ff) | |
1613 | fuse_file_put(ff, 0); | |
1614 | ||
1615 | return err; | |
1616 | } | |
1617 | ||
1618 | static int fuse_writepage_locked(struct page *page) | |
1619 | { | |
1620 | struct address_space *mapping = page->mapping; | |
1621 | struct inode *inode = mapping->host; | |
1622 | struct fuse_conn *fc = get_fuse_conn(inode); | |
1623 | struct fuse_inode *fi = get_fuse_inode(inode); | |
1624 | struct fuse_req *req; | |
1625 | struct page *tmp_page; | |
1626 | int error = -ENOMEM; | |
1627 | ||
1628 | set_page_writeback(page); | |
1629 | ||
1630 | req = fuse_request_alloc_nofs(1); | |
1631 | if (!req) | |
1632 | goto err; | |
1633 | ||
1634 | /* writeback always goes to bg_queue */ | |
1635 | __set_bit(FR_BACKGROUND, &req->flags); | |
1636 | tmp_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM); | |
1637 | if (!tmp_page) | |
1638 | goto err_free; | |
1639 | ||
1640 | error = -EIO; | |
1641 | req->ff = fuse_write_file_get(fc, fi); | |
1642 | if (!req->ff) | |
1643 | goto err_nofile; | |
1644 | ||
1645 | fuse_write_fill(req, req->ff, page_offset(page), 0); | |
1646 | ||
1647 | copy_highpage(tmp_page, page); | |
1648 | req->misc.write.in.write_flags |= FUSE_WRITE_CACHE; | |
1649 | req->misc.write.next = NULL; | |
1650 | req->in.argpages = 1; | |
1651 | req->num_pages = 1; | |
1652 | req->pages[0] = tmp_page; | |
1653 | req->page_descs[0].offset = 0; | |
1654 | req->page_descs[0].length = PAGE_SIZE; | |
1655 | req->end = fuse_writepage_end; | |
1656 | req->inode = inode; | |
1657 | ||
1658 | inc_wb_stat(&inode_to_bdi(inode)->wb, WB_WRITEBACK); | |
1659 | inc_node_page_state(tmp_page, NR_WRITEBACK_TEMP); | |
1660 | ||
1661 | spin_lock(&fc->lock); | |
1662 | list_add(&req->writepages_entry, &fi->writepages); | |
1663 | list_add_tail(&req->list, &fi->queued_writes); | |
1664 | fuse_flush_writepages(inode); | |
1665 | spin_unlock(&fc->lock); | |
1666 | ||
1667 | end_page_writeback(page); | |
1668 | ||
1669 | return 0; | |
1670 | ||
1671 | err_nofile: | |
1672 | __free_page(tmp_page); | |
1673 | err_free: | |
1674 | fuse_request_free(req); | |
1675 | err: | |
1676 | end_page_writeback(page); | |
1677 | return error; | |
1678 | } | |
1679 | ||
1680 | static int fuse_writepage(struct page *page, struct writeback_control *wbc) | |
1681 | { | |
1682 | int err; | |
1683 | ||
1684 | if (fuse_page_is_writeback(page->mapping->host, page->index)) { | |
1685 | /* | |
1686 | * ->writepages() should be called for sync() and friends. We | |
1687 | * should only get here on direct reclaim and then we are | |
1688 | * allowed to skip a page which is already in flight | |
1689 | */ | |
1690 | WARN_ON(wbc->sync_mode == WB_SYNC_ALL); | |
1691 | ||
1692 | redirty_page_for_writepage(wbc, page); | |
1693 | return 0; | |
1694 | } | |
1695 | ||
1696 | err = fuse_writepage_locked(page); | |
1697 | unlock_page(page); | |
1698 | ||
1699 | return err; | |
1700 | } | |
1701 | ||
1702 | struct fuse_fill_wb_data { | |
1703 | struct fuse_req *req; | |
1704 | struct fuse_file *ff; | |
1705 | struct inode *inode; | |
1706 | struct page **orig_pages; | |
1707 | }; | |
1708 | ||
1709 | static void fuse_writepages_send(struct fuse_fill_wb_data *data) | |
1710 | { | |
1711 | struct fuse_req *req = data->req; | |
1712 | struct inode *inode = data->inode; | |
1713 | struct fuse_conn *fc = get_fuse_conn(inode); | |
1714 | struct fuse_inode *fi = get_fuse_inode(inode); | |
1715 | int num_pages = req->num_pages; | |
1716 | int i; | |
1717 | ||
1718 | req->ff = fuse_file_get(data->ff); | |
1719 | spin_lock(&fc->lock); | |
1720 | list_add_tail(&req->list, &fi->queued_writes); | |
1721 | fuse_flush_writepages(inode); | |
1722 | spin_unlock(&fc->lock); | |
1723 | ||
1724 | for (i = 0; i < num_pages; i++) | |
1725 | end_page_writeback(data->orig_pages[i]); | |
1726 | } | |
1727 | ||
1728 | static bool fuse_writepage_in_flight(struct fuse_req *new_req, | |
1729 | struct page *page) | |
1730 | { | |
1731 | struct fuse_conn *fc = get_fuse_conn(new_req->inode); | |
1732 | struct fuse_inode *fi = get_fuse_inode(new_req->inode); | |
1733 | struct fuse_req *tmp; | |
1734 | struct fuse_req *old_req; | |
1735 | bool found = false; | |
1736 | pgoff_t curr_index; | |
1737 | ||
1738 | BUG_ON(new_req->num_pages != 0); | |
1739 | ||
1740 | spin_lock(&fc->lock); | |
1741 | list_del(&new_req->writepages_entry); | |
1742 | list_for_each_entry(old_req, &fi->writepages, writepages_entry) { | |
1743 | BUG_ON(old_req->inode != new_req->inode); | |
1744 | curr_index = old_req->misc.write.in.offset >> PAGE_SHIFT; | |
1745 | if (curr_index <= page->index && | |
1746 | page->index < curr_index + old_req->num_pages) { | |
1747 | found = true; | |
1748 | break; | |
1749 | } | |
1750 | } | |
1751 | if (!found) { | |
1752 | list_add(&new_req->writepages_entry, &fi->writepages); | |
1753 | goto out_unlock; | |
1754 | } | |
1755 | ||
1756 | new_req->num_pages = 1; | |
1757 | for (tmp = old_req; tmp != NULL; tmp = tmp->misc.write.next) { | |
1758 | BUG_ON(tmp->inode != new_req->inode); | |
1759 | curr_index = tmp->misc.write.in.offset >> PAGE_SHIFT; | |
1760 | if (tmp->num_pages == 1 && | |
1761 | curr_index == page->index) { | |
1762 | old_req = tmp; | |
1763 | } | |
1764 | } | |
1765 | ||
1766 | if (old_req->num_pages == 1 && test_bit(FR_PENDING, &old_req->flags)) { | |
1767 | struct backing_dev_info *bdi = inode_to_bdi(page->mapping->host); | |
1768 | ||
1769 | copy_highpage(old_req->pages[0], page); | |
1770 | spin_unlock(&fc->lock); | |
1771 | ||
1772 | dec_wb_stat(&bdi->wb, WB_WRITEBACK); | |
1773 | dec_node_page_state(page, NR_WRITEBACK_TEMP); | |
1774 | wb_writeout_inc(&bdi->wb); | |
1775 | fuse_writepage_free(fc, new_req); | |
1776 | fuse_request_free(new_req); | |
1777 | goto out; | |
1778 | } else { | |
1779 | new_req->misc.write.next = old_req->misc.write.next; | |
1780 | old_req->misc.write.next = new_req; | |
1781 | } | |
1782 | out_unlock: | |
1783 | spin_unlock(&fc->lock); | |
1784 | out: | |
1785 | return found; | |
1786 | } | |
1787 | ||
1788 | static int fuse_writepages_fill(struct page *page, | |
1789 | struct writeback_control *wbc, void *_data) | |
1790 | { | |
1791 | struct fuse_fill_wb_data *data = _data; | |
1792 | struct fuse_req *req = data->req; | |
1793 | struct inode *inode = data->inode; | |
1794 | struct fuse_conn *fc = get_fuse_conn(inode); | |
1795 | struct page *tmp_page; | |
1796 | bool is_writeback; | |
1797 | int err; | |
1798 | ||
1799 | if (!data->ff) { | |
1800 | err = -EIO; | |
1801 | data->ff = fuse_write_file_get(fc, get_fuse_inode(inode)); | |
1802 | if (!data->ff) | |
1803 | goto out_unlock; | |
1804 | } | |
1805 | ||
1806 | /* | |
1807 | * Being under writeback is unlikely but possible. For example direct | |
1808 | * read to an mmaped fuse file will set the page dirty twice; once when | |
1809 | * the pages are faulted with get_user_pages(), and then after the read | |
1810 | * completed. | |
1811 | */ | |
1812 | is_writeback = fuse_page_is_writeback(inode, page->index); | |
1813 | ||
1814 | if (req && req->num_pages && | |
1815 | (is_writeback || req->num_pages == FUSE_MAX_PAGES_PER_REQ || | |
1816 | (req->num_pages + 1) * PAGE_SIZE > fc->max_write || | |
1817 | data->orig_pages[req->num_pages - 1]->index + 1 != page->index)) { | |
1818 | fuse_writepages_send(data); | |
1819 | data->req = NULL; | |
1820 | } | |
1821 | err = -ENOMEM; | |
1822 | tmp_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM); | |
1823 | if (!tmp_page) | |
1824 | goto out_unlock; | |
1825 | ||
1826 | /* | |
1827 | * The page must not be redirtied until the writeout is completed | |
1828 | * (i.e. userspace has sent a reply to the write request). Otherwise | |
1829 | * there could be more than one temporary page instance for each real | |
1830 | * page. | |
1831 | * | |
1832 | * This is ensured by holding the page lock in page_mkwrite() while | |
1833 | * checking fuse_page_is_writeback(). We already hold the page lock | |
1834 | * since clear_page_dirty_for_io() and keep it held until we add the | |
1835 | * request to the fi->writepages list and increment req->num_pages. | |
1836 | * After this fuse_page_is_writeback() will indicate that the page is | |
1837 | * under writeback, so we can release the page lock. | |
1838 | */ | |
1839 | if (data->req == NULL) { | |
1840 | struct fuse_inode *fi = get_fuse_inode(inode); | |
1841 | ||
1842 | err = -ENOMEM; | |
1843 | req = fuse_request_alloc_nofs(FUSE_MAX_PAGES_PER_REQ); | |
1844 | if (!req) { | |
1845 | __free_page(tmp_page); | |
1846 | goto out_unlock; | |
1847 | } | |
1848 | ||
1849 | fuse_write_fill(req, data->ff, page_offset(page), 0); | |
1850 | req->misc.write.in.write_flags |= FUSE_WRITE_CACHE; | |
1851 | req->misc.write.next = NULL; | |
1852 | req->in.argpages = 1; | |
1853 | __set_bit(FR_BACKGROUND, &req->flags); | |
1854 | req->num_pages = 0; | |
1855 | req->end = fuse_writepage_end; | |
1856 | req->inode = inode; | |
1857 | ||
1858 | spin_lock(&fc->lock); | |
1859 | list_add(&req->writepages_entry, &fi->writepages); | |
1860 | spin_unlock(&fc->lock); | |
1861 | ||
1862 | data->req = req; | |
1863 | } | |
1864 | set_page_writeback(page); | |
1865 | ||
1866 | copy_highpage(tmp_page, page); | |
1867 | req->pages[req->num_pages] = tmp_page; | |
1868 | req->page_descs[req->num_pages].offset = 0; | |
1869 | req->page_descs[req->num_pages].length = PAGE_SIZE; | |
1870 | ||
1871 | inc_wb_stat(&inode_to_bdi(inode)->wb, WB_WRITEBACK); | |
1872 | inc_node_page_state(tmp_page, NR_WRITEBACK_TEMP); | |
1873 | ||
1874 | err = 0; | |
1875 | if (is_writeback && fuse_writepage_in_flight(req, page)) { | |
1876 | end_page_writeback(page); | |
1877 | data->req = NULL; | |
1878 | goto out_unlock; | |
1879 | } | |
1880 | data->orig_pages[req->num_pages] = page; | |
1881 | ||
1882 | /* | |
1883 | * Protected by fc->lock against concurrent access by | |
1884 | * fuse_page_is_writeback(). | |
1885 | */ | |
1886 | spin_lock(&fc->lock); | |
1887 | req->num_pages++; | |
1888 | spin_unlock(&fc->lock); | |
1889 | ||
1890 | out_unlock: | |
1891 | unlock_page(page); | |
1892 | ||
1893 | return err; | |
1894 | } | |
1895 | ||
1896 | static int fuse_writepages(struct address_space *mapping, | |
1897 | struct writeback_control *wbc) | |
1898 | { | |
1899 | struct inode *inode = mapping->host; | |
1900 | struct fuse_fill_wb_data data; | |
1901 | int err; | |
1902 | ||
1903 | err = -EIO; | |
1904 | if (is_bad_inode(inode)) | |
1905 | goto out; | |
1906 | ||
1907 | data.inode = inode; | |
1908 | data.req = NULL; | |
1909 | data.ff = NULL; | |
1910 | ||
1911 | err = -ENOMEM; | |
1912 | data.orig_pages = kcalloc(FUSE_MAX_PAGES_PER_REQ, | |
1913 | sizeof(struct page *), | |
1914 | GFP_NOFS); | |
1915 | if (!data.orig_pages) | |
1916 | goto out; | |
1917 | ||
1918 | err = write_cache_pages(mapping, wbc, fuse_writepages_fill, &data); | |
1919 | if (data.req) { | |
1920 | /* Ignore errors if we can write at least one page */ | |
1921 | BUG_ON(!data.req->num_pages); | |
1922 | fuse_writepages_send(&data); | |
1923 | err = 0; | |
1924 | } | |
1925 | if (data.ff) | |
1926 | fuse_file_put(data.ff, false); | |
1927 | ||
1928 | kfree(data.orig_pages); | |
1929 | out: | |
1930 | return err; | |
1931 | } | |
1932 | ||
1933 | /* | |
1934 | * It's worthy to make sure that space is reserved on disk for the write, | |
1935 | * but how to implement it without killing performance need more thinking. | |
1936 | */ | |
1937 | static int fuse_write_begin(struct file *file, struct address_space *mapping, | |
1938 | loff_t pos, unsigned len, unsigned flags, | |
1939 | struct page **pagep, void **fsdata) | |
1940 | { | |
1941 | pgoff_t index = pos >> PAGE_SHIFT; | |
1942 | struct fuse_conn *fc = get_fuse_conn(file_inode(file)); | |
1943 | struct page *page; | |
1944 | loff_t fsize; | |
1945 | int err = -ENOMEM; | |
1946 | ||
1947 | WARN_ON(!fc->writeback_cache); | |
1948 | ||
1949 | page = grab_cache_page_write_begin(mapping, index, flags); | |
1950 | if (!page) | |
1951 | goto error; | |
1952 | ||
1953 | fuse_wait_on_page_writeback(mapping->host, page->index); | |
1954 | ||
1955 | if (PageUptodate(page) || len == PAGE_SIZE) | |
1956 | goto success; | |
1957 | /* | |
1958 | * Check if the start this page comes after the end of file, in which | |
1959 | * case the readpage can be optimized away. | |
1960 | */ | |
1961 | fsize = i_size_read(mapping->host); | |
1962 | if (fsize <= (pos & PAGE_MASK)) { | |
1963 | size_t off = pos & ~PAGE_MASK; | |
1964 | if (off) | |
1965 | zero_user_segment(page, 0, off); | |
1966 | goto success; | |
1967 | } | |
1968 | err = fuse_do_readpage(file, page); | |
1969 | if (err) | |
1970 | goto cleanup; | |
1971 | success: | |
1972 | *pagep = page; | |
1973 | return 0; | |
1974 | ||
1975 | cleanup: | |
1976 | unlock_page(page); | |
1977 | put_page(page); | |
1978 | error: | |
1979 | return err; | |
1980 | } | |
1981 | ||
1982 | static int fuse_write_end(struct file *file, struct address_space *mapping, | |
1983 | loff_t pos, unsigned len, unsigned copied, | |
1984 | struct page *page, void *fsdata) | |
1985 | { | |
1986 | struct inode *inode = page->mapping->host; | |
1987 | ||
1988 | /* Haven't copied anything? Skip zeroing, size extending, dirtying. */ | |
1989 | if (!copied) | |
1990 | goto unlock; | |
1991 | ||
1992 | if (!PageUptodate(page)) { | |
1993 | /* Zero any unwritten bytes at the end of the page */ | |
1994 | size_t endoff = (pos + copied) & ~PAGE_MASK; | |
1995 | if (endoff) | |
1996 | zero_user_segment(page, endoff, PAGE_SIZE); | |
1997 | SetPageUptodate(page); | |
1998 | } | |
1999 | ||
2000 | fuse_write_update_size(inode, pos + copied); | |
2001 | set_page_dirty(page); | |
2002 | ||
2003 | unlock: | |
2004 | unlock_page(page); | |
2005 | put_page(page); | |
2006 | ||
2007 | return copied; | |
2008 | } | |
2009 | ||
2010 | static int fuse_launder_page(struct page *page) | |
2011 | { | |
2012 | int err = 0; | |
2013 | if (clear_page_dirty_for_io(page)) { | |
2014 | struct inode *inode = page->mapping->host; | |
2015 | err = fuse_writepage_locked(page); | |
2016 | if (!err) | |
2017 | fuse_wait_on_page_writeback(inode, page->index); | |
2018 | } | |
2019 | return err; | |
2020 | } | |
2021 | ||
2022 | /* | |
2023 | * Write back dirty pages now, because there may not be any suitable | |
2024 | * open files later | |
2025 | */ | |
2026 | static void fuse_vma_close(struct vm_area_struct *vma) | |
2027 | { | |
2028 | filemap_write_and_wait(vma->vm_file->f_mapping); | |
2029 | } | |
2030 | ||
2031 | /* | |
2032 | * Wait for writeback against this page to complete before allowing it | |
2033 | * to be marked dirty again, and hence written back again, possibly | |
2034 | * before the previous writepage completed. | |
2035 | * | |
2036 | * Block here, instead of in ->writepage(), so that the userspace fs | |
2037 | * can only block processes actually operating on the filesystem. | |
2038 | * | |
2039 | * Otherwise unprivileged userspace fs would be able to block | |
2040 | * unrelated: | |
2041 | * | |
2042 | * - page migration | |
2043 | * - sync(2) | |
2044 | * - try_to_free_pages() with order > PAGE_ALLOC_COSTLY_ORDER | |
2045 | */ | |
2046 | static int fuse_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) | |
2047 | { | |
2048 | struct page *page = vmf->page; | |
2049 | struct inode *inode = file_inode(vma->vm_file); | |
2050 | ||
2051 | file_update_time(vma->vm_file); | |
2052 | lock_page(page); | |
2053 | if (page->mapping != inode->i_mapping) { | |
2054 | unlock_page(page); | |
2055 | return VM_FAULT_NOPAGE; | |
2056 | } | |
2057 | ||
2058 | fuse_wait_on_page_writeback(inode, page->index); | |
2059 | return VM_FAULT_LOCKED; | |
2060 | } | |
2061 | ||
2062 | static const struct vm_operations_struct fuse_file_vm_ops = { | |
2063 | .close = fuse_vma_close, | |
2064 | .fault = filemap_fault, | |
2065 | .map_pages = filemap_map_pages, | |
2066 | .page_mkwrite = fuse_page_mkwrite, | |
2067 | }; | |
2068 | ||
2069 | static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma) | |
2070 | { | |
2071 | if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_MAYWRITE)) | |
2072 | fuse_link_write_file(file); | |
2073 | ||
2074 | file_accessed(file); | |
2075 | vma->vm_ops = &fuse_file_vm_ops; | |
2076 | return 0; | |
2077 | } | |
2078 | ||
2079 | static int fuse_direct_mmap(struct file *file, struct vm_area_struct *vma) | |
2080 | { | |
2081 | /* Can't provide the coherency needed for MAP_SHARED */ | |
2082 | if (vma->vm_flags & VM_MAYSHARE) | |
2083 | return -ENODEV; | |
2084 | ||
2085 | invalidate_inode_pages2(file->f_mapping); | |
2086 | ||
2087 | return generic_file_mmap(file, vma); | |
2088 | } | |
2089 | ||
2090 | static int convert_fuse_file_lock(const struct fuse_file_lock *ffl, | |
2091 | struct file_lock *fl) | |
2092 | { | |
2093 | switch (ffl->type) { | |
2094 | case F_UNLCK: | |
2095 | break; | |
2096 | ||
2097 | case F_RDLCK: | |
2098 | case F_WRLCK: | |
2099 | if (ffl->start > OFFSET_MAX || ffl->end > OFFSET_MAX || | |
2100 | ffl->end < ffl->start) | |
2101 | return -EIO; | |
2102 | ||
2103 | fl->fl_start = ffl->start; | |
2104 | fl->fl_end = ffl->end; | |
2105 | fl->fl_pid = ffl->pid; | |
2106 | break; | |
2107 | ||
2108 | default: | |
2109 | return -EIO; | |
2110 | } | |
2111 | fl->fl_type = ffl->type; | |
2112 | return 0; | |
2113 | } | |
2114 | ||
2115 | static void fuse_lk_fill(struct fuse_args *args, struct file *file, | |
2116 | const struct file_lock *fl, int opcode, pid_t pid, | |
2117 | int flock, struct fuse_lk_in *inarg) | |
2118 | { | |
2119 | struct inode *inode = file_inode(file); | |
2120 | struct fuse_conn *fc = get_fuse_conn(inode); | |
2121 | struct fuse_file *ff = file->private_data; | |
2122 | ||
2123 | memset(inarg, 0, sizeof(*inarg)); | |
2124 | inarg->fh = ff->fh; | |
2125 | inarg->owner = fuse_lock_owner_id(fc, fl->fl_owner); | |
2126 | inarg->lk.start = fl->fl_start; | |
2127 | inarg->lk.end = fl->fl_end; | |
2128 | inarg->lk.type = fl->fl_type; | |
2129 | inarg->lk.pid = pid; | |
2130 | if (flock) | |
2131 | inarg->lk_flags |= FUSE_LK_FLOCK; | |
2132 | args->in.h.opcode = opcode; | |
2133 | args->in.h.nodeid = get_node_id(inode); | |
2134 | args->in.numargs = 1; | |
2135 | args->in.args[0].size = sizeof(*inarg); | |
2136 | args->in.args[0].value = inarg; | |
2137 | } | |
2138 | ||
2139 | static int fuse_getlk(struct file *file, struct file_lock *fl) | |
2140 | { | |
2141 | struct inode *inode = file_inode(file); | |
2142 | struct fuse_conn *fc = get_fuse_conn(inode); | |
2143 | FUSE_ARGS(args); | |
2144 | struct fuse_lk_in inarg; | |
2145 | struct fuse_lk_out outarg; | |
2146 | int err; | |
2147 | ||
2148 | fuse_lk_fill(&args, file, fl, FUSE_GETLK, 0, 0, &inarg); | |
2149 | args.out.numargs = 1; | |
2150 | args.out.args[0].size = sizeof(outarg); | |
2151 | args.out.args[0].value = &outarg; | |
2152 | err = fuse_simple_request(fc, &args); | |
2153 | if (!err) | |
2154 | err = convert_fuse_file_lock(&outarg.lk, fl); | |
2155 | ||
2156 | return err; | |
2157 | } | |
2158 | ||
2159 | static int fuse_setlk(struct file *file, struct file_lock *fl, int flock) | |
2160 | { | |
2161 | struct inode *inode = file_inode(file); | |
2162 | struct fuse_conn *fc = get_fuse_conn(inode); | |
2163 | FUSE_ARGS(args); | |
2164 | struct fuse_lk_in inarg; | |
2165 | int opcode = (fl->fl_flags & FL_SLEEP) ? FUSE_SETLKW : FUSE_SETLK; | |
2166 | pid_t pid = fl->fl_type != F_UNLCK ? current->tgid : 0; | |
2167 | int err; | |
2168 | ||
2169 | if (fl->fl_lmops && fl->fl_lmops->lm_grant) { | |
2170 | /* NLM needs asynchronous locks, which we don't support yet */ | |
2171 | return -ENOLCK; | |
2172 | } | |
2173 | ||
2174 | /* Unlock on close is handled by the flush method */ | |
2175 | if (fl->fl_flags & FL_CLOSE) | |
2176 | return 0; | |
2177 | ||
2178 | fuse_lk_fill(&args, file, fl, opcode, pid, flock, &inarg); | |
2179 | err = fuse_simple_request(fc, &args); | |
2180 | ||
2181 | /* locking is restartable */ | |
2182 | if (err == -EINTR) | |
2183 | err = -ERESTARTSYS; | |
2184 | ||
2185 | return err; | |
2186 | } | |
2187 | ||
2188 | static int fuse_file_lock(struct file *file, int cmd, struct file_lock *fl) | |
2189 | { | |
2190 | struct inode *inode = file_inode(file); | |
2191 | struct fuse_conn *fc = get_fuse_conn(inode); | |
2192 | int err; | |
2193 | ||
2194 | if (cmd == F_CANCELLK) { | |
2195 | err = 0; | |
2196 | } else if (cmd == F_GETLK) { | |
2197 | if (fc->no_lock) { | |
2198 | posix_test_lock(file, fl); | |
2199 | err = 0; | |
2200 | } else | |
2201 | err = fuse_getlk(file, fl); | |
2202 | } else { | |
2203 | if (fc->no_lock) | |
2204 | err = posix_lock_file(file, fl, NULL); | |
2205 | else | |
2206 | err = fuse_setlk(file, fl, 0); | |
2207 | } | |
2208 | return err; | |
2209 | } | |
2210 | ||
2211 | static int fuse_file_flock(struct file *file, int cmd, struct file_lock *fl) | |
2212 | { | |
2213 | struct inode *inode = file_inode(file); | |
2214 | struct fuse_conn *fc = get_fuse_conn(inode); | |
2215 | int err; | |
2216 | ||
2217 | if (fc->no_flock) { | |
2218 | err = locks_lock_file_wait(file, fl); | |
2219 | } else { | |
2220 | struct fuse_file *ff = file->private_data; | |
2221 | ||
2222 | /* emulate flock with POSIX locks */ | |
2223 | ff->flock = true; | |
2224 | err = fuse_setlk(file, fl, 1); | |
2225 | } | |
2226 | ||
2227 | return err; | |
2228 | } | |
2229 | ||
2230 | static sector_t fuse_bmap(struct address_space *mapping, sector_t block) | |
2231 | { | |
2232 | struct inode *inode = mapping->host; | |
2233 | struct fuse_conn *fc = get_fuse_conn(inode); | |
2234 | FUSE_ARGS(args); | |
2235 | struct fuse_bmap_in inarg; | |
2236 | struct fuse_bmap_out outarg; | |
2237 | int err; | |
2238 | ||
2239 | if (!inode->i_sb->s_bdev || fc->no_bmap) | |
2240 | return 0; | |
2241 | ||
2242 | memset(&inarg, 0, sizeof(inarg)); | |
2243 | inarg.block = block; | |
2244 | inarg.blocksize = inode->i_sb->s_blocksize; | |
2245 | args.in.h.opcode = FUSE_BMAP; | |
2246 | args.in.h.nodeid = get_node_id(inode); | |
2247 | args.in.numargs = 1; | |
2248 | args.in.args[0].size = sizeof(inarg); | |
2249 | args.in.args[0].value = &inarg; | |
2250 | args.out.numargs = 1; | |
2251 | args.out.args[0].size = sizeof(outarg); | |
2252 | args.out.args[0].value = &outarg; | |
2253 | err = fuse_simple_request(fc, &args); | |
2254 | if (err == -ENOSYS) | |
2255 | fc->no_bmap = 1; | |
2256 | ||
2257 | return err ? 0 : outarg.block; | |
2258 | } | |
2259 | ||
2260 | static loff_t fuse_lseek(struct file *file, loff_t offset, int whence) | |
2261 | { | |
2262 | struct inode *inode = file->f_mapping->host; | |
2263 | struct fuse_conn *fc = get_fuse_conn(inode); | |
2264 | struct fuse_file *ff = file->private_data; | |
2265 | FUSE_ARGS(args); | |
2266 | struct fuse_lseek_in inarg = { | |
2267 | .fh = ff->fh, | |
2268 | .offset = offset, | |
2269 | .whence = whence | |
2270 | }; | |
2271 | struct fuse_lseek_out outarg; | |
2272 | int err; | |
2273 | ||
2274 | if (fc->no_lseek) | |
2275 | goto fallback; | |
2276 | ||
2277 | args.in.h.opcode = FUSE_LSEEK; | |
2278 | args.in.h.nodeid = ff->nodeid; | |
2279 | args.in.numargs = 1; | |
2280 | args.in.args[0].size = sizeof(inarg); | |
2281 | args.in.args[0].value = &inarg; | |
2282 | args.out.numargs = 1; | |
2283 | args.out.args[0].size = sizeof(outarg); | |
2284 | args.out.args[0].value = &outarg; | |
2285 | err = fuse_simple_request(fc, &args); | |
2286 | if (err) { | |
2287 | if (err == -ENOSYS) { | |
2288 | fc->no_lseek = 1; | |
2289 | goto fallback; | |
2290 | } | |
2291 | return err; | |
2292 | } | |
2293 | ||
2294 | return vfs_setpos(file, outarg.offset, inode->i_sb->s_maxbytes); | |
2295 | ||
2296 | fallback: | |
2297 | err = fuse_update_attributes(inode, NULL, file, NULL); | |
2298 | if (!err) | |
2299 | return generic_file_llseek(file, offset, whence); | |
2300 | else | |
2301 | return err; | |
2302 | } | |
2303 | ||
2304 | static loff_t fuse_file_llseek(struct file *file, loff_t offset, int whence) | |
2305 | { | |
2306 | loff_t retval; | |
2307 | struct inode *inode = file_inode(file); | |
2308 | ||
2309 | switch (whence) { | |
2310 | case SEEK_SET: | |
2311 | case SEEK_CUR: | |
2312 | /* No i_mutex protection necessary for SEEK_CUR and SEEK_SET */ | |
2313 | retval = generic_file_llseek(file, offset, whence); | |
2314 | break; | |
2315 | case SEEK_END: | |
2316 | inode_lock(inode); | |
2317 | retval = fuse_update_attributes(inode, NULL, file, NULL); | |
2318 | if (!retval) | |
2319 | retval = generic_file_llseek(file, offset, whence); | |
2320 | inode_unlock(inode); | |
2321 | break; | |
2322 | case SEEK_HOLE: | |
2323 | case SEEK_DATA: | |
2324 | inode_lock(inode); | |
2325 | retval = fuse_lseek(file, offset, whence); | |
2326 | inode_unlock(inode); | |
2327 | break; | |
2328 | default: | |
2329 | retval = -EINVAL; | |
2330 | } | |
2331 | ||
2332 | return retval; | |
2333 | } | |
2334 | ||
2335 | /* | |
2336 | * CUSE servers compiled on 32bit broke on 64bit kernels because the | |
2337 | * ABI was defined to be 'struct iovec' which is different on 32bit | |
2338 | * and 64bit. Fortunately we can determine which structure the server | |
2339 | * used from the size of the reply. | |
2340 | */ | |
2341 | static int fuse_copy_ioctl_iovec_old(struct iovec *dst, void *src, | |
2342 | size_t transferred, unsigned count, | |
2343 | bool is_compat) | |
2344 | { | |
2345 | #ifdef CONFIG_COMPAT | |
2346 | if (count * sizeof(struct compat_iovec) == transferred) { | |
2347 | struct compat_iovec *ciov = src; | |
2348 | unsigned i; | |
2349 | ||
2350 | /* | |
2351 | * With this interface a 32bit server cannot support | |
2352 | * non-compat (i.e. ones coming from 64bit apps) ioctl | |
2353 | * requests | |
2354 | */ | |
2355 | if (!is_compat) | |
2356 | return -EINVAL; | |
2357 | ||
2358 | for (i = 0; i < count; i++) { | |
2359 | dst[i].iov_base = compat_ptr(ciov[i].iov_base); | |
2360 | dst[i].iov_len = ciov[i].iov_len; | |
2361 | } | |
2362 | return 0; | |
2363 | } | |
2364 | #endif | |
2365 | ||
2366 | if (count * sizeof(struct iovec) != transferred) | |
2367 | return -EIO; | |
2368 | ||
2369 | memcpy(dst, src, transferred); | |
2370 | return 0; | |
2371 | } | |
2372 | ||
2373 | /* Make sure iov_length() won't overflow */ | |
2374 | static int fuse_verify_ioctl_iov(struct iovec *iov, size_t count) | |
2375 | { | |
2376 | size_t n; | |
2377 | u32 max = FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT; | |
2378 | ||
2379 | for (n = 0; n < count; n++, iov++) { | |
2380 | if (iov->iov_len > (size_t) max) | |
2381 | return -ENOMEM; | |
2382 | max -= iov->iov_len; | |
2383 | } | |
2384 | return 0; | |
2385 | } | |
2386 | ||
2387 | static int fuse_copy_ioctl_iovec(struct fuse_conn *fc, struct iovec *dst, | |
2388 | void *src, size_t transferred, unsigned count, | |
2389 | bool is_compat) | |
2390 | { | |
2391 | unsigned i; | |
2392 | struct fuse_ioctl_iovec *fiov = src; | |
2393 | ||
2394 | if (fc->minor < 16) { | |
2395 | return fuse_copy_ioctl_iovec_old(dst, src, transferred, | |
2396 | count, is_compat); | |
2397 | } | |
2398 | ||
2399 | if (count * sizeof(struct fuse_ioctl_iovec) != transferred) | |
2400 | return -EIO; | |
2401 | ||
2402 | for (i = 0; i < count; i++) { | |
2403 | /* Did the server supply an inappropriate value? */ | |
2404 | if (fiov[i].base != (unsigned long) fiov[i].base || | |
2405 | fiov[i].len != (unsigned long) fiov[i].len) | |
2406 | return -EIO; | |
2407 | ||
2408 | dst[i].iov_base = (void __user *) (unsigned long) fiov[i].base; | |
2409 | dst[i].iov_len = (size_t) fiov[i].len; | |
2410 | ||
2411 | #ifdef CONFIG_COMPAT | |
2412 | if (is_compat && | |
2413 | (ptr_to_compat(dst[i].iov_base) != fiov[i].base || | |
2414 | (compat_size_t) dst[i].iov_len != fiov[i].len)) | |
2415 | return -EIO; | |
2416 | #endif | |
2417 | } | |
2418 | ||
2419 | return 0; | |
2420 | } | |
2421 | ||
2422 | ||
2423 | /* | |
2424 | * For ioctls, there is no generic way to determine how much memory | |
2425 | * needs to be read and/or written. Furthermore, ioctls are allowed | |
2426 | * to dereference the passed pointer, so the parameter requires deep | |
2427 | * copying but FUSE has no idea whatsoever about what to copy in or | |
2428 | * out. | |
2429 | * | |
2430 | * This is solved by allowing FUSE server to retry ioctl with | |
2431 | * necessary in/out iovecs. Let's assume the ioctl implementation | |
2432 | * needs to read in the following structure. | |
2433 | * | |
2434 | * struct a { | |
2435 | * char *buf; | |
2436 | * size_t buflen; | |
2437 | * } | |
2438 | * | |
2439 | * On the first callout to FUSE server, inarg->in_size and | |
2440 | * inarg->out_size will be NULL; then, the server completes the ioctl | |
2441 | * with FUSE_IOCTL_RETRY set in out->flags, out->in_iovs set to 1 and | |
2442 | * the actual iov array to | |
2443 | * | |
2444 | * { { .iov_base = inarg.arg, .iov_len = sizeof(struct a) } } | |
2445 | * | |
2446 | * which tells FUSE to copy in the requested area and retry the ioctl. | |
2447 | * On the second round, the server has access to the structure and | |
2448 | * from that it can tell what to look for next, so on the invocation, | |
2449 | * it sets FUSE_IOCTL_RETRY, out->in_iovs to 2 and iov array to | |
2450 | * | |
2451 | * { { .iov_base = inarg.arg, .iov_len = sizeof(struct a) }, | |
2452 | * { .iov_base = a.buf, .iov_len = a.buflen } } | |
2453 | * | |
2454 | * FUSE will copy both struct a and the pointed buffer from the | |
2455 | * process doing the ioctl and retry ioctl with both struct a and the | |
2456 | * buffer. | |
2457 | * | |
2458 | * This time, FUSE server has everything it needs and completes ioctl | |
2459 | * without FUSE_IOCTL_RETRY which finishes the ioctl call. | |
2460 | * | |
2461 | * Copying data out works the same way. | |
2462 | * | |
2463 | * Note that if FUSE_IOCTL_UNRESTRICTED is clear, the kernel | |
2464 | * automatically initializes in and out iovs by decoding @cmd with | |
2465 | * _IOC_* macros and the server is not allowed to request RETRY. This | |
2466 | * limits ioctl data transfers to well-formed ioctls and is the forced | |
2467 | * behavior for all FUSE servers. | |
2468 | */ | |
2469 | long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg, | |
2470 | unsigned int flags) | |
2471 | { | |
2472 | struct fuse_file *ff = file->private_data; | |
2473 | struct fuse_conn *fc = ff->fc; | |
2474 | struct fuse_ioctl_in inarg = { | |
2475 | .fh = ff->fh, | |
2476 | .cmd = cmd, | |
2477 | .arg = arg, | |
2478 | .flags = flags | |
2479 | }; | |
2480 | struct fuse_ioctl_out outarg; | |
2481 | struct fuse_req *req = NULL; | |
2482 | struct page **pages = NULL; | |
2483 | struct iovec *iov_page = NULL; | |
2484 | struct iovec *in_iov = NULL, *out_iov = NULL; | |
2485 | unsigned int in_iovs = 0, out_iovs = 0, num_pages = 0, max_pages; | |
2486 | size_t in_size, out_size, transferred, c; | |
2487 | int err, i; | |
2488 | struct iov_iter ii; | |
2489 | ||
2490 | #if BITS_PER_LONG == 32 | |
2491 | inarg.flags |= FUSE_IOCTL_32BIT; | |
2492 | #else | |
2493 | if (flags & FUSE_IOCTL_COMPAT) | |
2494 | inarg.flags |= FUSE_IOCTL_32BIT; | |
2495 | #endif | |
2496 | ||
2497 | /* assume all the iovs returned by client always fits in a page */ | |
2498 | BUILD_BUG_ON(sizeof(struct fuse_ioctl_iovec) * FUSE_IOCTL_MAX_IOV > PAGE_SIZE); | |
2499 | ||
2500 | err = -ENOMEM; | |
2501 | pages = kcalloc(FUSE_MAX_PAGES_PER_REQ, sizeof(pages[0]), GFP_KERNEL); | |
2502 | iov_page = (struct iovec *) __get_free_page(GFP_KERNEL); | |
2503 | if (!pages || !iov_page) | |
2504 | goto out; | |
2505 | ||
2506 | /* | |
2507 | * If restricted, initialize IO parameters as encoded in @cmd. | |
2508 | * RETRY from server is not allowed. | |
2509 | */ | |
2510 | if (!(flags & FUSE_IOCTL_UNRESTRICTED)) { | |
2511 | struct iovec *iov = iov_page; | |
2512 | ||
2513 | iov->iov_base = (void __user *)arg; | |
2514 | iov->iov_len = _IOC_SIZE(cmd); | |
2515 | ||
2516 | if (_IOC_DIR(cmd) & _IOC_WRITE) { | |
2517 | in_iov = iov; | |
2518 | in_iovs = 1; | |
2519 | } | |
2520 | ||
2521 | if (_IOC_DIR(cmd) & _IOC_READ) { | |
2522 | out_iov = iov; | |
2523 | out_iovs = 1; | |
2524 | } | |
2525 | } | |
2526 | ||
2527 | retry: | |
2528 | inarg.in_size = in_size = iov_length(in_iov, in_iovs); | |
2529 | inarg.out_size = out_size = iov_length(out_iov, out_iovs); | |
2530 | ||
2531 | /* | |
2532 | * Out data can be used either for actual out data or iovs, | |
2533 | * make sure there always is at least one page. | |
2534 | */ | |
2535 | out_size = max_t(size_t, out_size, PAGE_SIZE); | |
2536 | max_pages = DIV_ROUND_UP(max(in_size, out_size), PAGE_SIZE); | |
2537 | ||
2538 | /* make sure there are enough buffer pages and init request with them */ | |
2539 | err = -ENOMEM; | |
2540 | if (max_pages > FUSE_MAX_PAGES_PER_REQ) | |
2541 | goto out; | |
2542 | while (num_pages < max_pages) { | |
2543 | pages[num_pages] = alloc_page(GFP_KERNEL | __GFP_HIGHMEM); | |
2544 | if (!pages[num_pages]) | |
2545 | goto out; | |
2546 | num_pages++; | |
2547 | } | |
2548 | ||
2549 | req = fuse_get_req(fc, num_pages); | |
2550 | if (IS_ERR(req)) { | |
2551 | err = PTR_ERR(req); | |
2552 | req = NULL; | |
2553 | goto out; | |
2554 | } | |
2555 | memcpy(req->pages, pages, sizeof(req->pages[0]) * num_pages); | |
2556 | req->num_pages = num_pages; | |
2557 | fuse_page_descs_length_init(req, 0, req->num_pages); | |
2558 | ||
2559 | /* okay, let's send it to the client */ | |
2560 | req->in.h.opcode = FUSE_IOCTL; | |
2561 | req->in.h.nodeid = ff->nodeid; | |
2562 | req->in.numargs = 1; | |
2563 | req->in.args[0].size = sizeof(inarg); | |
2564 | req->in.args[0].value = &inarg; | |
2565 | if (in_size) { | |
2566 | req->in.numargs++; | |
2567 | req->in.args[1].size = in_size; | |
2568 | req->in.argpages = 1; | |
2569 | ||
2570 | err = -EFAULT; | |
2571 | iov_iter_init(&ii, WRITE, in_iov, in_iovs, in_size); | |
2572 | for (i = 0; iov_iter_count(&ii) && !WARN_ON(i >= num_pages); i++) { | |
2573 | c = copy_page_from_iter(pages[i], 0, PAGE_SIZE, &ii); | |
2574 | if (c != PAGE_SIZE && iov_iter_count(&ii)) | |
2575 | goto out; | |
2576 | } | |
2577 | } | |
2578 | ||
2579 | req->out.numargs = 2; | |
2580 | req->out.args[0].size = sizeof(outarg); | |
2581 | req->out.args[0].value = &outarg; | |
2582 | req->out.args[1].size = out_size; | |
2583 | req->out.argpages = 1; | |
2584 | req->out.argvar = 1; | |
2585 | ||
2586 | fuse_request_send(fc, req); | |
2587 | err = req->out.h.error; | |
2588 | transferred = req->out.args[1].size; | |
2589 | fuse_put_request(fc, req); | |
2590 | req = NULL; | |
2591 | if (err) | |
2592 | goto out; | |
2593 | ||
2594 | /* did it ask for retry? */ | |
2595 | if (outarg.flags & FUSE_IOCTL_RETRY) { | |
2596 | void *vaddr; | |
2597 | ||
2598 | /* no retry if in restricted mode */ | |
2599 | err = -EIO; | |
2600 | if (!(flags & FUSE_IOCTL_UNRESTRICTED)) | |
2601 | goto out; | |
2602 | ||
2603 | in_iovs = outarg.in_iovs; | |
2604 | out_iovs = outarg.out_iovs; | |
2605 | ||
2606 | /* | |
2607 | * Make sure things are in boundary, separate checks | |
2608 | * are to protect against overflow. | |
2609 | */ | |
2610 | err = -ENOMEM; | |
2611 | if (in_iovs > FUSE_IOCTL_MAX_IOV || | |
2612 | out_iovs > FUSE_IOCTL_MAX_IOV || | |
2613 | in_iovs + out_iovs > FUSE_IOCTL_MAX_IOV) | |
2614 | goto out; | |
2615 | ||
2616 | vaddr = kmap_atomic(pages[0]); | |
2617 | err = fuse_copy_ioctl_iovec(fc, iov_page, vaddr, | |
2618 | transferred, in_iovs + out_iovs, | |
2619 | (flags & FUSE_IOCTL_COMPAT) != 0); | |
2620 | kunmap_atomic(vaddr); | |
2621 | if (err) | |
2622 | goto out; | |
2623 | ||
2624 | in_iov = iov_page; | |
2625 | out_iov = in_iov + in_iovs; | |
2626 | ||
2627 | err = fuse_verify_ioctl_iov(in_iov, in_iovs); | |
2628 | if (err) | |
2629 | goto out; | |
2630 | ||
2631 | err = fuse_verify_ioctl_iov(out_iov, out_iovs); | |
2632 | if (err) | |
2633 | goto out; | |
2634 | ||
2635 | goto retry; | |
2636 | } | |
2637 | ||
2638 | err = -EIO; | |
2639 | if (transferred > inarg.out_size) | |
2640 | goto out; | |
2641 | ||
2642 | err = -EFAULT; | |
2643 | iov_iter_init(&ii, READ, out_iov, out_iovs, transferred); | |
2644 | for (i = 0; iov_iter_count(&ii) && !WARN_ON(i >= num_pages); i++) { | |
2645 | c = copy_page_to_iter(pages[i], 0, PAGE_SIZE, &ii); | |
2646 | if (c != PAGE_SIZE && iov_iter_count(&ii)) | |
2647 | goto out; | |
2648 | } | |
2649 | err = 0; | |
2650 | out: | |
2651 | if (req) | |
2652 | fuse_put_request(fc, req); | |
2653 | free_page((unsigned long) iov_page); | |
2654 | while (num_pages) | |
2655 | __free_page(pages[--num_pages]); | |
2656 | kfree(pages); | |
2657 | ||
2658 | return err ? err : outarg.result; | |
2659 | } | |
2660 | EXPORT_SYMBOL_GPL(fuse_do_ioctl); | |
2661 | ||
2662 | long fuse_ioctl_common(struct file *file, unsigned int cmd, | |
2663 | unsigned long arg, unsigned int flags) | |
2664 | { | |
2665 | struct inode *inode = file_inode(file); | |
2666 | struct fuse_conn *fc = get_fuse_conn(inode); | |
2667 | ||
2668 | if (!fuse_allow_current_process(fc)) | |
2669 | return -EACCES; | |
2670 | ||
2671 | if (is_bad_inode(inode)) | |
2672 | return -EIO; | |
2673 | ||
2674 | return fuse_do_ioctl(file, cmd, arg, flags); | |
2675 | } | |
2676 | ||
2677 | static long fuse_file_ioctl(struct file *file, unsigned int cmd, | |
2678 | unsigned long arg) | |
2679 | { | |
2680 | return fuse_ioctl_common(file, cmd, arg, 0); | |
2681 | } | |
2682 | ||
2683 | static long fuse_file_compat_ioctl(struct file *file, unsigned int cmd, | |
2684 | unsigned long arg) | |
2685 | { | |
2686 | return fuse_ioctl_common(file, cmd, arg, FUSE_IOCTL_COMPAT); | |
2687 | } | |
2688 | ||
2689 | /* | |
2690 | * All files which have been polled are linked to RB tree | |
2691 | * fuse_conn->polled_files which is indexed by kh. Walk the tree and | |
2692 | * find the matching one. | |
2693 | */ | |
2694 | static struct rb_node **fuse_find_polled_node(struct fuse_conn *fc, u64 kh, | |
2695 | struct rb_node **parent_out) | |
2696 | { | |
2697 | struct rb_node **link = &fc->polled_files.rb_node; | |
2698 | struct rb_node *last = NULL; | |
2699 | ||
2700 | while (*link) { | |
2701 | struct fuse_file *ff; | |
2702 | ||
2703 | last = *link; | |
2704 | ff = rb_entry(last, struct fuse_file, polled_node); | |
2705 | ||
2706 | if (kh < ff->kh) | |
2707 | link = &last->rb_left; | |
2708 | else if (kh > ff->kh) | |
2709 | link = &last->rb_right; | |
2710 | else | |
2711 | return link; | |
2712 | } | |
2713 | ||
2714 | if (parent_out) | |
2715 | *parent_out = last; | |
2716 | return link; | |
2717 | } | |
2718 | ||
2719 | /* | |
2720 | * The file is about to be polled. Make sure it's on the polled_files | |
2721 | * RB tree. Note that files once added to the polled_files tree are | |
2722 | * not removed before the file is released. This is because a file | |
2723 | * polled once is likely to be polled again. | |
2724 | */ | |
2725 | static void fuse_register_polled_file(struct fuse_conn *fc, | |
2726 | struct fuse_file *ff) | |
2727 | { | |
2728 | spin_lock(&fc->lock); | |
2729 | if (RB_EMPTY_NODE(&ff->polled_node)) { | |
2730 | struct rb_node **link, *uninitialized_var(parent); | |
2731 | ||
2732 | link = fuse_find_polled_node(fc, ff->kh, &parent); | |
2733 | BUG_ON(*link); | |
2734 | rb_link_node(&ff->polled_node, parent, link); | |
2735 | rb_insert_color(&ff->polled_node, &fc->polled_files); | |
2736 | } | |
2737 | spin_unlock(&fc->lock); | |
2738 | } | |
2739 | ||
2740 | unsigned fuse_file_poll(struct file *file, poll_table *wait) | |
2741 | { | |
2742 | struct fuse_file *ff = file->private_data; | |
2743 | struct fuse_conn *fc = ff->fc; | |
2744 | struct fuse_poll_in inarg = { .fh = ff->fh, .kh = ff->kh }; | |
2745 | struct fuse_poll_out outarg; | |
2746 | FUSE_ARGS(args); | |
2747 | int err; | |
2748 | ||
2749 | if (fc->no_poll) | |
2750 | return DEFAULT_POLLMASK; | |
2751 | ||
2752 | poll_wait(file, &ff->poll_wait, wait); | |
2753 | inarg.events = (__u32)poll_requested_events(wait); | |
2754 | ||
2755 | /* | |
2756 | * Ask for notification iff there's someone waiting for it. | |
2757 | * The client may ignore the flag and always notify. | |
2758 | */ | |
2759 | if (waitqueue_active(&ff->poll_wait)) { | |
2760 | inarg.flags |= FUSE_POLL_SCHEDULE_NOTIFY; | |
2761 | fuse_register_polled_file(fc, ff); | |
2762 | } | |
2763 | ||
2764 | args.in.h.opcode = FUSE_POLL; | |
2765 | args.in.h.nodeid = ff->nodeid; | |
2766 | args.in.numargs = 1; | |
2767 | args.in.args[0].size = sizeof(inarg); | |
2768 | args.in.args[0].value = &inarg; | |
2769 | args.out.numargs = 1; | |
2770 | args.out.args[0].size = sizeof(outarg); | |
2771 | args.out.args[0].value = &outarg; | |
2772 | err = fuse_simple_request(fc, &args); | |
2773 | ||
2774 | if (!err) | |
2775 | return outarg.revents; | |
2776 | if (err == -ENOSYS) { | |
2777 | fc->no_poll = 1; | |
2778 | return DEFAULT_POLLMASK; | |
2779 | } | |
2780 | return POLLERR; | |
2781 | } | |
2782 | EXPORT_SYMBOL_GPL(fuse_file_poll); | |
2783 | ||
2784 | /* | |
2785 | * This is called from fuse_handle_notify() on FUSE_NOTIFY_POLL and | |
2786 | * wakes up the poll waiters. | |
2787 | */ | |
2788 | int fuse_notify_poll_wakeup(struct fuse_conn *fc, | |
2789 | struct fuse_notify_poll_wakeup_out *outarg) | |
2790 | { | |
2791 | u64 kh = outarg->kh; | |
2792 | struct rb_node **link; | |
2793 | ||
2794 | spin_lock(&fc->lock); | |
2795 | ||
2796 | link = fuse_find_polled_node(fc, kh, NULL); | |
2797 | if (*link) { | |
2798 | struct fuse_file *ff; | |
2799 | ||
2800 | ff = rb_entry(*link, struct fuse_file, polled_node); | |
2801 | wake_up_interruptible_sync(&ff->poll_wait); | |
2802 | } | |
2803 | ||
2804 | spin_unlock(&fc->lock); | |
2805 | return 0; | |
2806 | } | |
2807 | ||
2808 | static void fuse_do_truncate(struct file *file) | |
2809 | { | |
2810 | struct inode *inode = file->f_mapping->host; | |
2811 | struct iattr attr; | |
2812 | ||
2813 | attr.ia_valid = ATTR_SIZE; | |
2814 | attr.ia_size = i_size_read(inode); | |
2815 | ||
2816 | attr.ia_file = file; | |
2817 | attr.ia_valid |= ATTR_FILE; | |
2818 | ||
2819 | fuse_do_setattr(file_dentry(file), &attr, file); | |
2820 | } | |
2821 | ||
2822 | static inline loff_t fuse_round_up(loff_t off) | |
2823 | { | |
2824 | return round_up(off, FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT); | |
2825 | } | |
2826 | ||
2827 | static ssize_t | |
2828 | fuse_direct_IO(struct kiocb *iocb, struct iov_iter *iter) | |
2829 | { | |
2830 | DECLARE_COMPLETION_ONSTACK(wait); | |
2831 | ssize_t ret = 0; | |
2832 | struct file *file = iocb->ki_filp; | |
2833 | struct fuse_file *ff = file->private_data; | |
2834 | bool async_dio = ff->fc->async_dio; | |
2835 | loff_t pos = 0; | |
2836 | struct inode *inode; | |
2837 | loff_t i_size; | |
2838 | size_t count = iov_iter_count(iter); | |
2839 | loff_t offset = iocb->ki_pos; | |
2840 | struct fuse_io_priv *io; | |
2841 | ||
2842 | pos = offset; | |
2843 | inode = file->f_mapping->host; | |
2844 | i_size = i_size_read(inode); | |
2845 | ||
2846 | if ((iov_iter_rw(iter) == READ) && (offset > i_size)) | |
2847 | return 0; | |
2848 | ||
2849 | /* optimization for short read */ | |
2850 | if (async_dio && iov_iter_rw(iter) != WRITE && offset + count > i_size) { | |
2851 | if (offset >= i_size) | |
2852 | return 0; | |
2853 | iov_iter_truncate(iter, fuse_round_up(i_size - offset)); | |
2854 | count = iov_iter_count(iter); | |
2855 | } | |
2856 | ||
2857 | io = kmalloc(sizeof(struct fuse_io_priv), GFP_KERNEL); | |
2858 | if (!io) | |
2859 | return -ENOMEM; | |
2860 | spin_lock_init(&io->lock); | |
2861 | kref_init(&io->refcnt); | |
2862 | io->reqs = 1; | |
2863 | io->bytes = -1; | |
2864 | io->size = 0; | |
2865 | io->offset = offset; | |
2866 | io->write = (iov_iter_rw(iter) == WRITE); | |
2867 | io->err = 0; | |
2868 | io->file = file; | |
2869 | /* | |
2870 | * By default, we want to optimize all I/Os with async request | |
2871 | * submission to the client filesystem if supported. | |
2872 | */ | |
2873 | io->async = async_dio; | |
2874 | io->iocb = iocb; | |
2875 | io->blocking = is_sync_kiocb(iocb); | |
2876 | ||
2877 | /* | |
2878 | * We cannot asynchronously extend the size of a file. | |
2879 | * In such case the aio will behave exactly like sync io. | |
2880 | */ | |
2881 | if ((offset + count > i_size) && iov_iter_rw(iter) == WRITE) | |
2882 | io->blocking = true; | |
2883 | ||
2884 | if (io->async && io->blocking) { | |
2885 | /* | |
2886 | * Additional reference to keep io around after | |
2887 | * calling fuse_aio_complete() | |
2888 | */ | |
2889 | kref_get(&io->refcnt); | |
2890 | io->done = &wait; | |
2891 | } | |
2892 | ||
2893 | if (iov_iter_rw(iter) == WRITE) { | |
2894 | ret = fuse_direct_io(io, iter, &pos, FUSE_DIO_WRITE); | |
2895 | fuse_invalidate_attr(inode); | |
2896 | } else { | |
2897 | ret = __fuse_direct_read(io, iter, &pos); | |
2898 | } | |
2899 | ||
2900 | if (io->async) { | |
2901 | fuse_aio_complete(io, ret < 0 ? ret : 0, -1); | |
2902 | ||
2903 | /* we have a non-extending, async request, so return */ | |
2904 | if (!io->blocking) | |
2905 | return -EIOCBQUEUED; | |
2906 | ||
2907 | wait_for_completion(&wait); | |
2908 | ret = fuse_get_res_by_io(io); | |
2909 | } | |
2910 | ||
2911 | kref_put(&io->refcnt, fuse_io_release); | |
2912 | ||
2913 | if (iov_iter_rw(iter) == WRITE) { | |
2914 | if (ret > 0) | |
2915 | fuse_write_update_size(inode, pos); | |
2916 | else if (ret < 0 && offset + count > i_size) | |
2917 | fuse_do_truncate(file); | |
2918 | } | |
2919 | ||
2920 | return ret; | |
2921 | } | |
2922 | ||
2923 | static long fuse_file_fallocate(struct file *file, int mode, loff_t offset, | |
2924 | loff_t length) | |
2925 | { | |
2926 | struct fuse_file *ff = file->private_data; | |
2927 | struct inode *inode = file_inode(file); | |
2928 | struct fuse_inode *fi = get_fuse_inode(inode); | |
2929 | struct fuse_conn *fc = ff->fc; | |
2930 | FUSE_ARGS(args); | |
2931 | struct fuse_fallocate_in inarg = { | |
2932 | .fh = ff->fh, | |
2933 | .offset = offset, | |
2934 | .length = length, | |
2935 | .mode = mode | |
2936 | }; | |
2937 | int err; | |
2938 | bool lock_inode = !(mode & FALLOC_FL_KEEP_SIZE) || | |
2939 | (mode & FALLOC_FL_PUNCH_HOLE); | |
2940 | ||
2941 | if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE)) | |
2942 | return -EOPNOTSUPP; | |
2943 | ||
2944 | if (fc->no_fallocate) | |
2945 | return -EOPNOTSUPP; | |
2946 | ||
2947 | if (lock_inode) { | |
2948 | inode_lock(inode); | |
2949 | if (mode & FALLOC_FL_PUNCH_HOLE) { | |
2950 | loff_t endbyte = offset + length - 1; | |
2951 | err = filemap_write_and_wait_range(inode->i_mapping, | |
2952 | offset, endbyte); | |
2953 | if (err) | |
2954 | goto out; | |
2955 | ||
2956 | fuse_sync_writes(inode); | |
2957 | } | |
2958 | } | |
2959 | ||
2960 | if (!(mode & FALLOC_FL_KEEP_SIZE)) | |
2961 | set_bit(FUSE_I_SIZE_UNSTABLE, &fi->state); | |
2962 | ||
2963 | args.in.h.opcode = FUSE_FALLOCATE; | |
2964 | args.in.h.nodeid = ff->nodeid; | |
2965 | args.in.numargs = 1; | |
2966 | args.in.args[0].size = sizeof(inarg); | |
2967 | args.in.args[0].value = &inarg; | |
2968 | err = fuse_simple_request(fc, &args); | |
2969 | if (err == -ENOSYS) { | |
2970 | fc->no_fallocate = 1; | |
2971 | err = -EOPNOTSUPP; | |
2972 | } | |
2973 | if (err) | |
2974 | goto out; | |
2975 | ||
2976 | /* we could have extended the file */ | |
2977 | if (!(mode & FALLOC_FL_KEEP_SIZE)) { | |
2978 | bool changed = fuse_write_update_size(inode, offset + length); | |
2979 | ||
2980 | if (changed && fc->writeback_cache) | |
2981 | file_update_time(file); | |
2982 | } | |
2983 | ||
2984 | if (mode & FALLOC_FL_PUNCH_HOLE) | |
2985 | truncate_pagecache_range(inode, offset, offset + length - 1); | |
2986 | ||
2987 | fuse_invalidate_attr(inode); | |
2988 | ||
2989 | out: | |
2990 | if (!(mode & FALLOC_FL_KEEP_SIZE)) | |
2991 | clear_bit(FUSE_I_SIZE_UNSTABLE, &fi->state); | |
2992 | ||
2993 | if (lock_inode) | |
2994 | inode_unlock(inode); | |
2995 | ||
2996 | return err; | |
2997 | } | |
2998 | ||
2999 | static const struct file_operations fuse_file_operations = { | |
3000 | .llseek = fuse_file_llseek, | |
3001 | .read_iter = fuse_file_read_iter, | |
3002 | .write_iter = fuse_file_write_iter, | |
3003 | .mmap = fuse_file_mmap, | |
3004 | .open = fuse_open, | |
3005 | .flush = fuse_flush, | |
3006 | .release = fuse_release, | |
3007 | .fsync = fuse_fsync, | |
3008 | .lock = fuse_file_lock, | |
3009 | .flock = fuse_file_flock, | |
3010 | .splice_read = generic_file_splice_read, | |
3011 | .unlocked_ioctl = fuse_file_ioctl, | |
3012 | .compat_ioctl = fuse_file_compat_ioctl, | |
3013 | .poll = fuse_file_poll, | |
3014 | .fallocate = fuse_file_fallocate, | |
3015 | }; | |
3016 | ||
3017 | static const struct file_operations fuse_direct_io_file_operations = { | |
3018 | .llseek = fuse_file_llseek, | |
3019 | .read_iter = fuse_direct_read_iter, | |
3020 | .write_iter = fuse_direct_write_iter, | |
3021 | .mmap = fuse_direct_mmap, | |
3022 | .open = fuse_open, | |
3023 | .flush = fuse_flush, | |
3024 | .release = fuse_release, | |
3025 | .fsync = fuse_fsync, | |
3026 | .lock = fuse_file_lock, | |
3027 | .flock = fuse_file_flock, | |
3028 | .unlocked_ioctl = fuse_file_ioctl, | |
3029 | .compat_ioctl = fuse_file_compat_ioctl, | |
3030 | .poll = fuse_file_poll, | |
3031 | .fallocate = fuse_file_fallocate, | |
3032 | /* no splice_read */ | |
3033 | }; | |
3034 | ||
3035 | static const struct address_space_operations fuse_file_aops = { | |
3036 | .readpage = fuse_readpage, | |
3037 | .writepage = fuse_writepage, | |
3038 | .writepages = fuse_writepages, | |
3039 | .launder_page = fuse_launder_page, | |
3040 | .readpages = fuse_readpages, | |
3041 | .set_page_dirty = __set_page_dirty_nobuffers, | |
3042 | .bmap = fuse_bmap, | |
3043 | .direct_IO = fuse_direct_IO, | |
3044 | .write_begin = fuse_write_begin, | |
3045 | .write_end = fuse_write_end, | |
3046 | }; | |
3047 | ||
3048 | void fuse_init_file_inode(struct inode *inode) | |
3049 | { | |
3050 | inode->i_fop = &fuse_file_operations; | |
3051 | inode->i_data.a_ops = &fuse_file_aops; | |
3052 | } |