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kbuild: fix silentoldconfig with make O=
[linux-2.6/verdex.git] / fs / fuse / file.c
blob6454022b05367c3818fa24e3d7dab7dd5a45bfae
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
15 static struct file_operations fuse_direct_io_file_operations;
16
17 int fuse_open_common(struct inode *inode, struct file *file, int isdir)
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
26 err = generic_file_open(inode, file);
27 if (err)
28 return err;
29
30 /* If opening the root node, no lookup has been performed on
31 it, so the attributes must be refreshed */
32 if (get_node_id(inode) == FUSE_ROOT_ID) {
33 int err = fuse_do_getattr(inode);
34 if (err)
35 return err;
36 }
37
38 req = fuse_get_request(fc);
39 if (!req)
40 return -EINTR;
41
42 err = -ENOMEM;
43 ff = kmalloc(sizeof(struct fuse_file), GFP_KERNEL);
44 if (!ff)
45 goto out_put_request;
46
47 ff->release_req = fuse_request_alloc();
48 if (!ff->release_req) {
49 kfree(ff);
50 goto out_put_request;
51 }
52
53 memset(&inarg, 0, sizeof(inarg));
54 inarg.flags = file->f_flags & ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);
55 req->in.h.opcode = isdir ? FUSE_OPENDIR : FUSE_OPEN;
56 req->in.h.nodeid = get_node_id(inode);
57 req->inode = inode;
58 req->in.numargs = 1;
59 req->in.args[0].size = sizeof(inarg);
60 req->in.args[0].value = &inarg;
61 req->out.numargs = 1;
62 req->out.args[0].size = sizeof(outarg);
63 req->out.args[0].value = &outarg;
64 request_send(fc, req);
65 err = req->out.h.error;
66 if (err) {
67 fuse_request_free(ff->release_req);
68 kfree(ff);
69 } else {
70 if (!isdir && (outarg.open_flags & FOPEN_DIRECT_IO))
71 file->f_op = &fuse_direct_io_file_operations;
72 if (!(outarg.open_flags & FOPEN_KEEP_CACHE))
73 invalidate_inode_pages(inode->i_mapping);
74 ff->fh = outarg.fh;
75 file->private_data = ff;
76 }
77
78 out_put_request:
79 fuse_put_request(fc, req);
80 return err;
81 }
82
83 int fuse_release_common(struct inode *inode, struct file *file, int isdir)
84 {
85 struct fuse_conn *fc = get_fuse_conn(inode);
86 struct fuse_file *ff = file->private_data;
87 struct fuse_req *req = ff->release_req;
88 struct fuse_release_in *inarg = &req->misc.release_in;
89
90 inarg->fh = ff->fh;
91 inarg->flags = file->f_flags & ~O_EXCL;
92 req->in.h.opcode = isdir ? FUSE_RELEASEDIR : FUSE_RELEASE;
93 req->in.h.nodeid = get_node_id(inode);
94 req->inode = inode;
95 req->in.numargs = 1;
96 req->in.args[0].size = sizeof(struct fuse_release_in);
97 req->in.args[0].value = inarg;
98 request_send_background(fc, req);
99 kfree(ff);
100
101 /* Return value is ignored by VFS */
102 return 0;
103 }
104
105 static int fuse_open(struct inode *inode, struct file *file)
106 {
107 return fuse_open_common(inode, file, 0);
108 }
109
110 static int fuse_release(struct inode *inode, struct file *file)
111 {
112 return fuse_release_common(inode, file, 0);
113 }
114
115 static int fuse_flush(struct file *file)
116 {
117 struct inode *inode = file->f_dentry->d_inode;
118 struct fuse_conn *fc = get_fuse_conn(inode);
119 struct fuse_file *ff = file->private_data;
120 struct fuse_req *req;
121 struct fuse_flush_in inarg;
122 int err;
123
124 if (fc->no_flush)
125 return 0;
126
127 req = fuse_get_request(fc);
128 if (!req)
129 return -EINTR;
130
131 memset(&inarg, 0, sizeof(inarg));
132 inarg.fh = ff->fh;
133 req->in.h.opcode = FUSE_FLUSH;
134 req->in.h.nodeid = get_node_id(inode);
135 req->inode = inode;
136 req->file = file;
137 req->in.numargs = 1;
138 req->in.args[0].size = sizeof(inarg);
139 req->in.args[0].value = &inarg;
140 request_send(fc, req);
141 err = req->out.h.error;
142 fuse_put_request(fc, req);
143 if (err == -ENOSYS) {
144 fc->no_flush = 1;
145 err = 0;
146 }
147 return err;
148 }
149
150 int fuse_fsync_common(struct file *file, struct dentry *de, int datasync,
151 int isdir)
152 {
153 struct inode *inode = de->d_inode;
154 struct fuse_conn *fc = get_fuse_conn(inode);
155 struct fuse_file *ff = file->private_data;
156 struct fuse_req *req;
157 struct fuse_fsync_in inarg;
158 int err;
159
160 if ((!isdir && fc->no_fsync) || (isdir && fc->no_fsyncdir))
161 return 0;
162
163 req = fuse_get_request(fc);
164 if (!req)
165 return -EINTR;
166
167 memset(&inarg, 0, sizeof(inarg));
168 inarg.fh = ff->fh;
169 inarg.fsync_flags = datasync ? 1 : 0;
170 req->in.h.opcode = isdir ? FUSE_FSYNCDIR : FUSE_FSYNC;
171 req->in.h.nodeid = get_node_id(inode);
172 req->inode = inode;
173 req->file = file;
174 req->in.numargs = 1;
175 req->in.args[0].size = sizeof(inarg);
176 req->in.args[0].value = &inarg;
177 request_send(fc, req);
178 err = req->out.h.error;
179 fuse_put_request(fc, req);
180 if (err == -ENOSYS) {
181 if (isdir)
182 fc->no_fsyncdir = 1;
183 else
184 fc->no_fsync = 1;
185 err = 0;
186 }
187 return err;
188 }
189
190 static int fuse_fsync(struct file *file, struct dentry *de, int datasync)
191 {
192 return fuse_fsync_common(file, de, datasync, 0);
193 }
194
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)
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;
207 req->in.h.opcode = isdir ? FUSE_READDIR : FUSE_READ;
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(fc, req);
219 return req->out.args[0].size;
220 }
221
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
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(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 fuse_invalidate_attr(inode); /* atime changed */
248 out:
249 unlock_page(page);
250 return err;
251 }
252
253 static int fuse_send_readpages(struct fuse_req *req, struct file *file,
254 struct inode *inode)
255 {
256 loff_t pos = (loff_t) req->pages[0]->index << PAGE_CACHE_SHIFT;
257 size_t count = req->num_pages << PAGE_CACHE_SHIFT;
258 unsigned i;
259 req->out.page_zeroing = 1;
260 fuse_send_read(req, file, inode, pos, count);
261 for (i = 0; i < req->num_pages; i++) {
262 struct page *page = req->pages[i];
263 if (!req->out.h.error)
264 SetPageUptodate(page);
265 unlock_page(page);
266 }
267 return req->out.h.error;
268 }
269
270 struct fuse_readpages_data {
271 struct fuse_req *req;
272 struct file *file;
273 struct inode *inode;
274 };
275
276 static int fuse_readpages_fill(void *_data, struct page *page)
277 {
278 struct fuse_readpages_data *data = _data;
279 struct fuse_req *req = data->req;
280 struct inode *inode = data->inode;
281 struct fuse_conn *fc = get_fuse_conn(inode);
282
283 if (req->num_pages &&
284 (req->num_pages == FUSE_MAX_PAGES_PER_REQ ||
285 (req->num_pages + 1) * PAGE_CACHE_SIZE > fc->max_read ||
286 req->pages[req->num_pages - 1]->index + 1 != page->index)) {
287 int err = fuse_send_readpages(req, data->file, inode);
288 if (err) {
289 unlock_page(page);
290 return err;
291 }
292 fuse_reset_request(req);
293 }
294 req->pages[req->num_pages] = page;
295 req->num_pages ++;
296 return 0;
297 }
298
299 static int fuse_readpages(struct file *file, struct address_space *mapping,
300 struct list_head *pages, unsigned nr_pages)
301 {
302 struct inode *inode = mapping->host;
303 struct fuse_conn *fc = get_fuse_conn(inode);
304 struct fuse_readpages_data data;
305 int err;
306 data.file = file;
307 data.inode = inode;
308 data.req = fuse_get_request(fc);
309 if (!data.req)
310 return -EINTR;
311
312 err = read_cache_pages(mapping, pages, fuse_readpages_fill, &data);
313 if (!err && data.req->num_pages)
314 err = fuse_send_readpages(data.req, file, inode);
315 fuse_put_request(fc, data.req);
316 fuse_invalidate_attr(inode); /* atime changed */
317 return err;
318 }
319
320 static size_t fuse_send_write(struct fuse_req *req, struct file *file,
321 struct inode *inode, loff_t pos, size_t count)
322 {
323 struct fuse_conn *fc = get_fuse_conn(inode);
324 struct fuse_file *ff = file->private_data;
325 struct fuse_write_in inarg;
326 struct fuse_write_out outarg;
327
328 memset(&inarg, 0, sizeof(struct fuse_write_in));
329 inarg.fh = ff->fh;
330 inarg.offset = pos;
331 inarg.size = count;
332 req->in.h.opcode = FUSE_WRITE;
333 req->in.h.nodeid = get_node_id(inode);
334 req->inode = inode;
335 req->file = file;
336 req->in.argpages = 1;
337 req->in.numargs = 2;
338 req->in.args[0].size = sizeof(struct fuse_write_in);
339 req->in.args[0].value = &inarg;
340 req->in.args[1].size = count;
341 req->out.numargs = 1;
342 req->out.args[0].size = sizeof(struct fuse_write_out);
343 req->out.args[0].value = &outarg;
344 request_send(fc, req);
345 return outarg.size;
346 }
347
348 static int fuse_prepare_write(struct file *file, struct page *page,
349 unsigned offset, unsigned to)
350 {
351 /* No op */
352 return 0;
353 }
354
355 static int fuse_commit_write(struct file *file, struct page *page,
356 unsigned offset, unsigned to)
357 {
358 int err;
359 size_t nres;
360 unsigned count = to - offset;
361 struct inode *inode = page->mapping->host;
362 struct fuse_conn *fc = get_fuse_conn(inode);
363 loff_t pos = ((loff_t) page->index << PAGE_CACHE_SHIFT) + offset;
364 struct fuse_req *req = fuse_get_request(fc);
365 if (!req)
366 return -EINTR;
367
368 req->num_pages = 1;
369 req->pages[0] = page;
370 req->page_offset = offset;
371 nres = fuse_send_write(req, file, inode, pos, count);
372 err = req->out.h.error;
373 fuse_put_request(fc, req);
374 if (!err && nres != count)
375 err = -EIO;
376 if (!err) {
377 pos += count;
378 if (pos > i_size_read(inode))
379 i_size_write(inode, pos);
380
381 if (offset == 0 && to == PAGE_CACHE_SIZE) {
382 clear_page_dirty(page);
383 SetPageUptodate(page);
384 }
385 }
386 fuse_invalidate_attr(inode);
387 return err;
388 }
389
390 static void fuse_release_user_pages(struct fuse_req *req, int write)
391 {
392 unsigned i;
393
394 for (i = 0; i < req->num_pages; i++) {
395 struct page *page = req->pages[i];
396 if (write)
397 set_page_dirty_lock(page);
398 put_page(page);
399 }
400 }
401
402 static int fuse_get_user_pages(struct fuse_req *req, const char __user *buf,
403 unsigned nbytes, int write)
404 {
405 unsigned long user_addr = (unsigned long) buf;
406 unsigned offset = user_addr & ~PAGE_MASK;
407 int npages;
408
409 /* This doesn't work with nfsd */
410 if (!current->mm)
411 return -EPERM;
412
413 nbytes = min(nbytes, (unsigned) FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT);
414 npages = (nbytes + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
415 npages = min(npages, FUSE_MAX_PAGES_PER_REQ);
416 down_read(&current->mm->mmap_sem);
417 npages = get_user_pages(current, current->mm, user_addr, npages, write,
418 0, req->pages, NULL);
419 up_read(&current->mm->mmap_sem);
420 if (npages < 0)
421 return npages;
422
423 req->num_pages = npages;
424 req->page_offset = offset;
425 return 0;
426 }
427
428 static ssize_t fuse_direct_io(struct file *file, const char __user *buf,
429 size_t count, loff_t *ppos, int write)
430 {
431 struct inode *inode = file->f_dentry->d_inode;
432 struct fuse_conn *fc = get_fuse_conn(inode);
433 size_t nmax = write ? fc->max_write : fc->max_read;
434 loff_t pos = *ppos;
435 ssize_t res = 0;
436 struct fuse_req *req = fuse_get_request(fc);
437 if (!req)
438 return -EINTR;
439
440 while (count) {
441 size_t tmp;
442 size_t nres;
443 size_t nbytes = min(count, nmax);
444 int err = fuse_get_user_pages(req, buf, nbytes, !write);
445 if (err) {
446 res = err;
447 break;
448 }
449 tmp = (req->num_pages << PAGE_SHIFT) - req->page_offset;
450 nbytes = min(nbytes, tmp);
451 if (write)
452 nres = fuse_send_write(req, file, inode, pos, nbytes);
453 else
454 nres = fuse_send_read(req, file, inode, pos, nbytes);
455 fuse_release_user_pages(req, !write);
456 if (req->out.h.error) {
457 if (!res)
458 res = req->out.h.error;
459 break;
460 } else if (nres > nbytes) {
461 res = -EIO;
462 break;
463 }
464 count -= nres;
465 res += nres;
466 pos += nres;
467 buf += nres;
468 if (nres != nbytes)
469 break;
470 if (count)
471 fuse_reset_request(req);
472 }
473 fuse_put_request(fc, req);
474 if (res > 0) {
475 if (write && pos > i_size_read(inode))
476 i_size_write(inode, pos);
477 *ppos = pos;
478 }
479 fuse_invalidate_attr(inode);
480
481 return res;
482 }
483
484 static ssize_t fuse_direct_read(struct file *file, char __user *buf,
485 size_t count, loff_t *ppos)
486 {
487 return fuse_direct_io(file, buf, count, ppos, 0);
488 }
489
490 static ssize_t fuse_direct_write(struct file *file, const char __user *buf,
491 size_t count, loff_t *ppos)
492 {
493 struct inode *inode = file->f_dentry->d_inode;
494 ssize_t res;
495 /* Don't allow parallel writes to the same file */
496 down(&inode->i_sem);
497 res = fuse_direct_io(file, buf, count, ppos, 1);
498 up(&inode->i_sem);
499 return res;
500 }
501
502 static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma)
503 {
504 if ((vma->vm_flags & VM_SHARED)) {
505 if ((vma->vm_flags & VM_WRITE))
506 return -ENODEV;
507 else
508 vma->vm_flags &= ~VM_MAYWRITE;
509 }
510 return generic_file_mmap(file, vma);
511 }
512
513 static int fuse_set_page_dirty(struct page *page)
514 {
515 printk("fuse_set_page_dirty: should not happen\n");
516 dump_stack();
517 return 0;
518 }
519
520 static struct file_operations fuse_file_operations = {
521 .llseek = generic_file_llseek,
522 .read = generic_file_read,
523 .write = generic_file_write,
524 .mmap = fuse_file_mmap,
525 .open = fuse_open,
526 .flush = fuse_flush,
527 .release = fuse_release,
528 .fsync = fuse_fsync,
529 .sendfile = generic_file_sendfile,
530 };
531
532 static struct file_operations fuse_direct_io_file_operations = {
533 .llseek = generic_file_llseek,
534 .read = fuse_direct_read,
535 .write = fuse_direct_write,
536 .open = fuse_open,
537 .flush = fuse_flush,
538 .release = fuse_release,
539 .fsync = fuse_fsync,
540 /* no mmap and sendfile */
541 };
542
543 static struct address_space_operations fuse_file_aops = {
544 .readpage = fuse_readpage,
545 .prepare_write = fuse_prepare_write,
546 .commit_write = fuse_commit_write,
547 .readpages = fuse_readpages,
548 .set_page_dirty = fuse_set_page_dirty,
549 };
550
551 void fuse_init_file_inode(struct inode *inode)
552 {
553 inode->i_fop = &fuse_file_operations;
554 inode->i_data.a_ops = &fuse_file_aops;
555 }
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