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Commit | Line | Data |
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b6aeaded MS |
1 | /* |
2 | FUSE: Filesystem in Userspace | |
3 | Copyright (C) 2001-2005 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 | ||
45323fb7 MS |
15 | static struct file_operations fuse_direct_io_file_operations; |
16 | ||
04730fef | 17 | int fuse_open_common(struct inode *inode, struct file *file, int isdir) |
b6aeaded MS |
18 | { |
19 | struct fuse_conn *fc = get_fuse_conn(inode); | |
20 | struct fuse_req *req; | |
21 | struct fuse_open_in inarg; | |
22 | struct fuse_open_out outarg; | |
23 | struct fuse_file *ff; | |
24 | int err; | |
25 | /* Restarting the syscall is not allowed if O_CREAT and O_EXCL | |
26 | are both set, because creation will fail on the restart */ | |
27 | int excl = (file->f_flags & (O_CREAT|O_EXCL)) == (O_CREAT|O_EXCL); | |
28 | ||
29 | err = generic_file_open(inode, file); | |
30 | if (err) | |
31 | return err; | |
32 | ||
33 | /* If opening the root node, no lookup has been performed on | |
34 | it, so the attributes must be refreshed */ | |
35 | if (get_node_id(inode) == FUSE_ROOT_ID) { | |
36 | int err = fuse_do_getattr(inode); | |
37 | if (err) | |
38 | return err; | |
39 | } | |
40 | ||
41 | if (excl) | |
42 | req = fuse_get_request_nonint(fc); | |
43 | else | |
44 | req = fuse_get_request(fc); | |
45 | if (!req) | |
46 | return excl ? -EINTR : -ERESTARTSYS; | |
47 | ||
48 | err = -ENOMEM; | |
49 | ff = kmalloc(sizeof(struct fuse_file), GFP_KERNEL); | |
50 | if (!ff) | |
51 | goto out_put_request; | |
52 | ||
53 | ff->release_req = fuse_request_alloc(); | |
54 | if (!ff->release_req) { | |
55 | kfree(ff); | |
56 | goto out_put_request; | |
57 | } | |
58 | ||
59 | memset(&inarg, 0, sizeof(inarg)); | |
60 | inarg.flags = file->f_flags & ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC); | |
04730fef | 61 | req->in.h.opcode = isdir ? FUSE_OPENDIR : FUSE_OPEN; |
b6aeaded MS |
62 | req->in.h.nodeid = get_node_id(inode); |
63 | req->inode = inode; | |
64 | req->in.numargs = 1; | |
65 | req->in.args[0].size = sizeof(inarg); | |
66 | req->in.args[0].value = &inarg; | |
67 | req->out.numargs = 1; | |
68 | req->out.args[0].size = sizeof(outarg); | |
69 | req->out.args[0].value = &outarg; | |
70 | if (excl) | |
71 | request_send_nonint(fc, req); | |
72 | else | |
73 | request_send(fc, req); | |
74 | err = req->out.h.error; | |
b6aeaded MS |
75 | if (err) { |
76 | fuse_request_free(ff->release_req); | |
77 | kfree(ff); | |
78 | } else { | |
45323fb7 MS |
79 | if (!isdir && (outarg.open_flags & FOPEN_DIRECT_IO)) |
80 | file->f_op = &fuse_direct_io_file_operations; | |
81 | if (!(outarg.open_flags & FOPEN_KEEP_CACHE)) | |
82 | invalidate_inode_pages(inode->i_mapping); | |
b6aeaded MS |
83 | ff->fh = outarg.fh; |
84 | file->private_data = ff; | |
85 | } | |
86 | ||
87 | out_put_request: | |
88 | fuse_put_request(fc, req); | |
89 | return err; | |
90 | } | |
91 | ||
04730fef | 92 | int fuse_release_common(struct inode *inode, struct file *file, int isdir) |
b6aeaded MS |
93 | { |
94 | struct fuse_conn *fc = get_fuse_conn(inode); | |
95 | struct fuse_file *ff = file->private_data; | |
96 | struct fuse_req *req = ff->release_req; | |
97 | struct fuse_release_in *inarg = &req->misc.release_in; | |
98 | ||
99 | inarg->fh = ff->fh; | |
100 | inarg->flags = file->f_flags & ~O_EXCL; | |
04730fef | 101 | req->in.h.opcode = isdir ? FUSE_RELEASEDIR : FUSE_RELEASE; |
b6aeaded MS |
102 | req->in.h.nodeid = get_node_id(inode); |
103 | req->inode = inode; | |
104 | req->in.numargs = 1; | |
105 | req->in.args[0].size = sizeof(struct fuse_release_in); | |
106 | req->in.args[0].value = inarg; | |
107 | request_send_background(fc, req); | |
108 | kfree(ff); | |
109 | ||
110 | /* Return value is ignored by VFS */ | |
111 | return 0; | |
112 | } | |
113 | ||
04730fef MS |
114 | static int fuse_open(struct inode *inode, struct file *file) |
115 | { | |
116 | return fuse_open_common(inode, file, 0); | |
117 | } | |
118 | ||
119 | static int fuse_release(struct inode *inode, struct file *file) | |
120 | { | |
121 | return fuse_release_common(inode, file, 0); | |
122 | } | |
123 | ||
b6aeaded MS |
124 | static int fuse_flush(struct file *file) |
125 | { | |
126 | struct inode *inode = file->f_dentry->d_inode; | |
127 | struct fuse_conn *fc = get_fuse_conn(inode); | |
128 | struct fuse_file *ff = file->private_data; | |
129 | struct fuse_req *req; | |
130 | struct fuse_flush_in inarg; | |
131 | int err; | |
132 | ||
133 | if (fc->no_flush) | |
134 | return 0; | |
135 | ||
136 | req = fuse_get_request_nonint(fc); | |
137 | if (!req) | |
138 | return -EINTR; | |
139 | ||
140 | memset(&inarg, 0, sizeof(inarg)); | |
141 | inarg.fh = ff->fh; | |
142 | req->in.h.opcode = FUSE_FLUSH; | |
143 | req->in.h.nodeid = get_node_id(inode); | |
144 | req->inode = inode; | |
145 | req->file = file; | |
146 | req->in.numargs = 1; | |
147 | req->in.args[0].size = sizeof(inarg); | |
148 | req->in.args[0].value = &inarg; | |
149 | request_send_nonint(fc, req); | |
150 | err = req->out.h.error; | |
151 | fuse_put_request(fc, req); | |
152 | if (err == -ENOSYS) { | |
153 | fc->no_flush = 1; | |
154 | err = 0; | |
155 | } | |
156 | return err; | |
157 | } | |
158 | ||
159 | static int fuse_fsync(struct file *file, struct dentry *de, int datasync) | |
160 | { | |
161 | struct inode *inode = de->d_inode; | |
162 | struct fuse_conn *fc = get_fuse_conn(inode); | |
163 | struct fuse_file *ff = file->private_data; | |
164 | struct fuse_req *req; | |
165 | struct fuse_fsync_in inarg; | |
166 | int err; | |
167 | ||
168 | if (fc->no_fsync) | |
169 | return 0; | |
170 | ||
171 | req = fuse_get_request(fc); | |
172 | if (!req) | |
173 | return -ERESTARTSYS; | |
174 | ||
175 | memset(&inarg, 0, sizeof(inarg)); | |
176 | inarg.fh = ff->fh; | |
177 | inarg.fsync_flags = datasync ? 1 : 0; | |
178 | req->in.h.opcode = FUSE_FSYNC; | |
179 | req->in.h.nodeid = get_node_id(inode); | |
180 | req->inode = inode; | |
181 | req->file = file; | |
182 | req->in.numargs = 1; | |
183 | req->in.args[0].size = sizeof(inarg); | |
184 | req->in.args[0].value = &inarg; | |
185 | request_send(fc, req); | |
186 | err = req->out.h.error; | |
187 | fuse_put_request(fc, req); | |
188 | if (err == -ENOSYS) { | |
189 | fc->no_fsync = 1; | |
190 | err = 0; | |
191 | } | |
192 | return err; | |
193 | } | |
194 | ||
04730fef MS |
195 | size_t fuse_send_read_common(struct fuse_req *req, struct file *file, |
196 | struct inode *inode, loff_t pos, size_t count, | |
197 | int isdir) | |
b6aeaded MS |
198 | { |
199 | struct fuse_conn *fc = get_fuse_conn(inode); | |
200 | struct fuse_file *ff = file->private_data; | |
201 | struct fuse_read_in inarg; | |
202 | ||
203 | memset(&inarg, 0, sizeof(struct fuse_read_in)); | |
204 | inarg.fh = ff->fh; | |
205 | inarg.offset = pos; | |
206 | inarg.size = count; | |
04730fef | 207 | req->in.h.opcode = isdir ? FUSE_READDIR : FUSE_READ; |
b6aeaded MS |
208 | req->in.h.nodeid = get_node_id(inode); |
209 | req->inode = inode; | |
210 | req->file = file; | |
211 | req->in.numargs = 1; | |
212 | req->in.args[0].size = sizeof(struct fuse_read_in); | |
213 | req->in.args[0].value = &inarg; | |
214 | req->out.argpages = 1; | |
215 | req->out.argvar = 1; | |
216 | req->out.numargs = 1; | |
217 | req->out.args[0].size = count; | |
218 | request_send_nonint(fc, req); | |
219 | return req->out.args[0].size; | |
220 | } | |
221 | ||
04730fef MS |
222 | static inline size_t fuse_send_read(struct fuse_req *req, struct file *file, |
223 | struct inode *inode, loff_t pos, | |
224 | size_t count) | |
225 | { | |
226 | return fuse_send_read_common(req, file, inode, pos, count, 0); | |
227 | } | |
228 | ||
b6aeaded MS |
229 | static int fuse_readpage(struct file *file, struct page *page) |
230 | { | |
231 | struct inode *inode = page->mapping->host; | |
232 | struct fuse_conn *fc = get_fuse_conn(inode); | |
233 | loff_t pos = (loff_t) page->index << PAGE_CACHE_SHIFT; | |
234 | struct fuse_req *req = fuse_get_request_nonint(fc); | |
235 | int err = -EINTR; | |
236 | if (!req) | |
237 | goto out; | |
238 | ||
239 | req->out.page_zeroing = 1; | |
240 | req->num_pages = 1; | |
241 | req->pages[0] = page; | |
242 | fuse_send_read(req, file, inode, pos, PAGE_CACHE_SIZE); | |
243 | err = req->out.h.error; | |
244 | fuse_put_request(fc, req); | |
245 | if (!err) | |
246 | SetPageUptodate(page); | |
247 | out: | |
248 | unlock_page(page); | |
249 | return err; | |
250 | } | |
251 | ||
db50b96c MS |
252 | static int fuse_send_readpages(struct fuse_req *req, struct file *file, |
253 | struct inode *inode) | |
254 | { | |
255 | loff_t pos = (loff_t) req->pages[0]->index << PAGE_CACHE_SHIFT; | |
256 | size_t count = req->num_pages << PAGE_CACHE_SHIFT; | |
257 | unsigned i; | |
258 | req->out.page_zeroing = 1; | |
259 | fuse_send_read(req, file, inode, pos, count); | |
260 | for (i = 0; i < req->num_pages; i++) { | |
261 | struct page *page = req->pages[i]; | |
262 | if (!req->out.h.error) | |
263 | SetPageUptodate(page); | |
264 | unlock_page(page); | |
265 | } | |
266 | return req->out.h.error; | |
267 | } | |
268 | ||
269 | struct fuse_readpages_data { | |
270 | struct fuse_req *req; | |
271 | struct file *file; | |
272 | struct inode *inode; | |
273 | }; | |
274 | ||
275 | static int fuse_readpages_fill(void *_data, struct page *page) | |
276 | { | |
277 | struct fuse_readpages_data *data = _data; | |
278 | struct fuse_req *req = data->req; | |
279 | struct inode *inode = data->inode; | |
280 | struct fuse_conn *fc = get_fuse_conn(inode); | |
281 | ||
282 | if (req->num_pages && | |
283 | (req->num_pages == FUSE_MAX_PAGES_PER_REQ || | |
284 | (req->num_pages + 1) * PAGE_CACHE_SIZE > fc->max_read || | |
285 | req->pages[req->num_pages - 1]->index + 1 != page->index)) { | |
286 | int err = fuse_send_readpages(req, data->file, inode); | |
287 | if (err) { | |
288 | unlock_page(page); | |
289 | return err; | |
290 | } | |
291 | fuse_reset_request(req); | |
292 | } | |
293 | req->pages[req->num_pages] = page; | |
294 | req->num_pages ++; | |
295 | return 0; | |
296 | } | |
297 | ||
298 | static int fuse_readpages(struct file *file, struct address_space *mapping, | |
299 | struct list_head *pages, unsigned nr_pages) | |
300 | { | |
301 | struct inode *inode = mapping->host; | |
302 | struct fuse_conn *fc = get_fuse_conn(inode); | |
303 | struct fuse_readpages_data data; | |
304 | int err; | |
305 | data.file = file; | |
306 | data.inode = inode; | |
307 | data.req = fuse_get_request_nonint(fc); | |
308 | if (!data.req) | |
309 | return -EINTR; | |
310 | ||
311 | err = read_cache_pages(mapping, pages, fuse_readpages_fill, &data); | |
312 | if (!err && data.req->num_pages) | |
313 | err = fuse_send_readpages(data.req, file, inode); | |
314 | fuse_put_request(fc, data.req); | |
315 | return err; | |
316 | } | |
317 | ||
04730fef MS |
318 | static size_t fuse_send_write(struct fuse_req *req, struct file *file, |
319 | struct inode *inode, loff_t pos, size_t count) | |
b6aeaded MS |
320 | { |
321 | struct fuse_conn *fc = get_fuse_conn(inode); | |
322 | struct fuse_file *ff = file->private_data; | |
323 | struct fuse_write_in inarg; | |
324 | struct fuse_write_out outarg; | |
325 | ||
326 | memset(&inarg, 0, sizeof(struct fuse_write_in)); | |
327 | inarg.fh = ff->fh; | |
328 | inarg.offset = pos; | |
329 | inarg.size = count; | |
330 | req->in.h.opcode = FUSE_WRITE; | |
331 | req->in.h.nodeid = get_node_id(inode); | |
332 | req->inode = inode; | |
333 | req->file = file; | |
334 | req->in.argpages = 1; | |
335 | req->in.numargs = 2; | |
336 | req->in.args[0].size = sizeof(struct fuse_write_in); | |
337 | req->in.args[0].value = &inarg; | |
338 | req->in.args[1].size = count; | |
339 | req->out.numargs = 1; | |
340 | req->out.args[0].size = sizeof(struct fuse_write_out); | |
341 | req->out.args[0].value = &outarg; | |
342 | request_send_nonint(fc, req); | |
343 | return outarg.size; | |
344 | } | |
345 | ||
346 | static int fuse_prepare_write(struct file *file, struct page *page, | |
347 | unsigned offset, unsigned to) | |
348 | { | |
349 | /* No op */ | |
350 | return 0; | |
351 | } | |
352 | ||
353 | static int fuse_commit_write(struct file *file, struct page *page, | |
354 | unsigned offset, unsigned to) | |
355 | { | |
356 | int err; | |
04730fef | 357 | size_t nres; |
b6aeaded MS |
358 | unsigned count = to - offset; |
359 | struct inode *inode = page->mapping->host; | |
360 | struct fuse_conn *fc = get_fuse_conn(inode); | |
361 | loff_t pos = ((loff_t) page->index << PAGE_CACHE_SHIFT) + offset; | |
362 | struct fuse_req *req = fuse_get_request_nonint(fc); | |
363 | if (!req) | |
364 | return -EINTR; | |
365 | ||
366 | req->num_pages = 1; | |
367 | req->pages[0] = page; | |
368 | req->page_offset = offset; | |
369 | nres = fuse_send_write(req, file, inode, pos, count); | |
370 | err = req->out.h.error; | |
371 | fuse_put_request(fc, req); | |
372 | if (!err && nres != count) | |
373 | err = -EIO; | |
374 | if (!err) { | |
375 | pos += count; | |
376 | if (pos > i_size_read(inode)) | |
377 | i_size_write(inode, pos); | |
378 | ||
379 | if (offset == 0 && to == PAGE_CACHE_SIZE) { | |
380 | clear_page_dirty(page); | |
381 | SetPageUptodate(page); | |
382 | } | |
383 | } else if (err == -EINTR || err == -EIO) | |
384 | fuse_invalidate_attr(inode); | |
385 | return err; | |
386 | } | |
387 | ||
413ef8cb MS |
388 | static void fuse_release_user_pages(struct fuse_req *req, int write) |
389 | { | |
390 | unsigned i; | |
391 | ||
392 | for (i = 0; i < req->num_pages; i++) { | |
393 | struct page *page = req->pages[i]; | |
394 | if (write) | |
395 | set_page_dirty_lock(page); | |
396 | put_page(page); | |
397 | } | |
398 | } | |
399 | ||
400 | static int fuse_get_user_pages(struct fuse_req *req, const char __user *buf, | |
401 | unsigned nbytes, int write) | |
402 | { | |
403 | unsigned long user_addr = (unsigned long) buf; | |
404 | unsigned offset = user_addr & ~PAGE_MASK; | |
405 | int npages; | |
406 | ||
407 | /* This doesn't work with nfsd */ | |
408 | if (!current->mm) | |
409 | return -EPERM; | |
410 | ||
411 | nbytes = min(nbytes, (unsigned) FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT); | |
412 | npages = (nbytes + offset + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
413 | npages = min(npages, FUSE_MAX_PAGES_PER_REQ); | |
414 | down_read(¤t->mm->mmap_sem); | |
415 | npages = get_user_pages(current, current->mm, user_addr, npages, write, | |
416 | 0, req->pages, NULL); | |
417 | up_read(¤t->mm->mmap_sem); | |
418 | if (npages < 0) | |
419 | return npages; | |
420 | ||
421 | req->num_pages = npages; | |
422 | req->page_offset = offset; | |
423 | return 0; | |
424 | } | |
425 | ||
426 | static ssize_t fuse_direct_io(struct file *file, const char __user *buf, | |
427 | size_t count, loff_t *ppos, int write) | |
428 | { | |
429 | struct inode *inode = file->f_dentry->d_inode; | |
430 | struct fuse_conn *fc = get_fuse_conn(inode); | |
431 | size_t nmax = write ? fc->max_write : fc->max_read; | |
432 | loff_t pos = *ppos; | |
433 | ssize_t res = 0; | |
434 | struct fuse_req *req = fuse_get_request(fc); | |
435 | if (!req) | |
436 | return -ERESTARTSYS; | |
437 | ||
438 | while (count) { | |
439 | size_t tmp; | |
440 | size_t nres; | |
441 | size_t nbytes = min(count, nmax); | |
442 | int err = fuse_get_user_pages(req, buf, nbytes, !write); | |
443 | if (err) { | |
444 | res = err; | |
445 | break; | |
446 | } | |
447 | tmp = (req->num_pages << PAGE_SHIFT) - req->page_offset; | |
448 | nbytes = min(nbytes, tmp); | |
449 | if (write) | |
450 | nres = fuse_send_write(req, file, inode, pos, nbytes); | |
451 | else | |
452 | nres = fuse_send_read(req, file, inode, pos, nbytes); | |
453 | fuse_release_user_pages(req, !write); | |
454 | if (req->out.h.error) { | |
455 | if (!res) | |
456 | res = req->out.h.error; | |
457 | break; | |
458 | } else if (nres > nbytes) { | |
459 | res = -EIO; | |
460 | break; | |
461 | } | |
462 | count -= nres; | |
463 | res += nres; | |
464 | pos += nres; | |
465 | buf += nres; | |
466 | if (nres != nbytes) | |
467 | break; | |
468 | if (count) | |
469 | fuse_reset_request(req); | |
470 | } | |
471 | fuse_put_request(fc, req); | |
472 | if (res > 0) { | |
473 | if (write && pos > i_size_read(inode)) | |
474 | i_size_write(inode, pos); | |
475 | *ppos = pos; | |
476 | } else if (write && (res == -EINTR || res == -EIO)) | |
477 | fuse_invalidate_attr(inode); | |
478 | ||
479 | return res; | |
480 | } | |
481 | ||
482 | static ssize_t fuse_direct_read(struct file *file, char __user *buf, | |
483 | size_t count, loff_t *ppos) | |
484 | { | |
485 | return fuse_direct_io(file, buf, count, ppos, 0); | |
486 | } | |
487 | ||
488 | static ssize_t fuse_direct_write(struct file *file, const char __user *buf, | |
489 | size_t count, loff_t *ppos) | |
490 | { | |
491 | struct inode *inode = file->f_dentry->d_inode; | |
492 | ssize_t res; | |
493 | /* Don't allow parallel writes to the same file */ | |
494 | down(&inode->i_sem); | |
495 | res = fuse_direct_io(file, buf, count, ppos, 1); | |
496 | up(&inode->i_sem); | |
497 | return res; | |
498 | } | |
499 | ||
b6aeaded MS |
500 | static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma) |
501 | { | |
502 | if ((vma->vm_flags & VM_SHARED)) { | |
503 | if ((vma->vm_flags & VM_WRITE)) | |
504 | return -ENODEV; | |
505 | else | |
506 | vma->vm_flags &= ~VM_MAYWRITE; | |
507 | } | |
508 | return generic_file_mmap(file, vma); | |
509 | } | |
510 | ||
511 | static int fuse_set_page_dirty(struct page *page) | |
512 | { | |
513 | printk("fuse_set_page_dirty: should not happen\n"); | |
514 | dump_stack(); | |
515 | return 0; | |
516 | } | |
517 | ||
518 | static struct file_operations fuse_file_operations = { | |
519 | .llseek = generic_file_llseek, | |
520 | .read = generic_file_read, | |
521 | .write = generic_file_write, | |
522 | .mmap = fuse_file_mmap, | |
523 | .open = fuse_open, | |
524 | .flush = fuse_flush, | |
525 | .release = fuse_release, | |
526 | .fsync = fuse_fsync, | |
527 | .sendfile = generic_file_sendfile, | |
528 | }; | |
529 | ||
413ef8cb MS |
530 | static struct file_operations fuse_direct_io_file_operations = { |
531 | .llseek = generic_file_llseek, | |
532 | .read = fuse_direct_read, | |
533 | .write = fuse_direct_write, | |
534 | .open = fuse_open, | |
535 | .flush = fuse_flush, | |
536 | .release = fuse_release, | |
537 | .fsync = fuse_fsync, | |
538 | /* no mmap and sendfile */ | |
539 | }; | |
540 | ||
b6aeaded MS |
541 | static struct address_space_operations fuse_file_aops = { |
542 | .readpage = fuse_readpage, | |
543 | .prepare_write = fuse_prepare_write, | |
544 | .commit_write = fuse_commit_write, | |
db50b96c | 545 | .readpages = fuse_readpages, |
b6aeaded MS |
546 | .set_page_dirty = fuse_set_page_dirty, |
547 | }; | |
548 | ||
549 | void fuse_init_file_inode(struct inode *inode) | |
550 | { | |
45323fb7 MS |
551 | inode->i_fop = &fuse_file_operations; |
552 | inode->i_data.a_ops = &fuse_file_aops; | |
b6aeaded | 553 | } |