1 |
/* |
2 |
FUSE: Filesystem in Userspace |
3 |
Copyright (C) 2001-2004 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 |
#include "fuse_i.h" |
9 |
|
10 |
#include <linux/pagemap.h> |
11 |
#include <linux/slab.h> |
12 |
#include <asm/uaccess.h> |
13 |
#ifdef KERNEL_2_6 |
14 |
#include <linux/backing-dev.h> |
15 |
#include <linux/writeback.h> |
16 |
#endif |
17 |
|
18 |
#ifndef KERNEL_2_6 |
19 |
#define PageUptodate(page) Page_Uptodate(page) |
20 |
#endif |
21 |
|
22 |
static int user_mmap; |
23 |
#ifdef KERNEL_2_6 |
24 |
#include <linux/moduleparam.h> |
25 |
module_param(user_mmap, int, 0); |
26 |
#else |
27 |
MODULE_PARM(user_mmap, "i"); |
28 |
#endif |
29 |
|
30 |
MODULE_PARM_DESC(user_mmap, "Allow non root user to create a shared writable mapping"); |
31 |
|
32 |
|
33 |
static int fuse_open(struct inode *inode, struct file *file) |
34 |
{ |
35 |
struct fuse_conn *fc = INO_FC(inode); |
36 |
struct fuse_req *req; |
37 |
struct fuse_open_in inarg; |
38 |
struct fuse_open_out outarg; |
39 |
struct fuse_file *ff; |
40 |
int err; |
41 |
|
42 |
err = generic_file_open(inode, file); |
43 |
if (err) |
44 |
return err; |
45 |
|
46 |
/* If opening the root node, no lookup has been performed on |
47 |
it, so the attributes must be refreshed */ |
48 |
if (inode->i_ino == FUSE_ROOT_INO) { |
49 |
int err = fuse_do_getattr(inode); |
50 |
if (err) |
51 |
return err; |
52 |
} |
53 |
|
54 |
down(&inode->i_sem); |
55 |
err = -ERESTARTSYS; |
56 |
req = fuse_get_request(fc); |
57 |
if (!req) |
58 |
goto out; |
59 |
|
60 |
err = -ENOMEM; |
61 |
ff = kmalloc(sizeof(struct fuse_file), GFP_KERNEL); |
62 |
if (!ff) |
63 |
goto out_put_request; |
64 |
|
65 |
ff->release_req = fuse_request_alloc(); |
66 |
if (!ff->release_req) { |
67 |
kfree(ff); |
68 |
goto out_put_request; |
69 |
} |
70 |
|
71 |
|
72 |
memset(&inarg, 0, sizeof(inarg)); |
73 |
inarg.flags = file->f_flags & ~O_EXCL; |
74 |
req->in.h.opcode = FUSE_OPEN; |
75 |
req->in.h.ino = inode->i_ino; |
76 |
req->in.numargs = 1; |
77 |
req->in.args[0].size = sizeof(inarg); |
78 |
req->in.args[0].value = &inarg; |
79 |
req->out.numargs = 1; |
80 |
req->out.args[0].size = sizeof(outarg); |
81 |
req->out.args[0].value = &outarg; |
82 |
request_send(fc, req); |
83 |
err = req->out.h.error; |
84 |
if (!err && !(fc->flags & FUSE_KERNEL_CACHE)) { |
85 |
#ifdef KERNEL_2_6 |
86 |
invalidate_inode_pages(inode->i_mapping); |
87 |
#else |
88 |
invalidate_inode_pages(inode); |
89 |
#endif |
90 |
} |
91 |
if (err) { |
92 |
fuse_request_free(ff->release_req); |
93 |
kfree(ff); |
94 |
} |
95 |
else { |
96 |
ff->fh = outarg.fh; |
97 |
file->private_data = ff; |
98 |
INIT_LIST_HEAD(&ff->ff_list); |
99 |
} |
100 |
|
101 |
out_put_request: |
102 |
fuse_put_request(fc, req); |
103 |
out: |
104 |
up(&inode->i_sem); |
105 |
return err; |
106 |
} |
107 |
|
108 |
void fuse_sync_inode(struct inode *inode) |
109 |
{ |
110 |
#ifdef KERNEL_2_6 |
111 |
filemap_fdatawrite(inode->i_mapping); |
112 |
filemap_fdatawait(inode->i_mapping); |
113 |
#else |
114 |
#ifndef NO_MM |
115 |
filemap_fdatasync(inode->i_mapping); |
116 |
filemap_fdatawait(inode->i_mapping); |
117 |
#endif |
118 |
#endif |
119 |
} |
120 |
|
121 |
static int fuse_release(struct inode *inode, struct file *file) |
122 |
{ |
123 |
struct fuse_conn *fc = INO_FC(inode); |
124 |
struct fuse_inode *fi = INO_FI(inode); |
125 |
struct fuse_release_in *inarg; |
126 |
struct fuse_file *ff = file->private_data; |
127 |
struct fuse_req *req = ff->release_req; |
128 |
|
129 |
down(&inode->i_sem); |
130 |
if (file->f_mode & FMODE_WRITE) |
131 |
fuse_sync_inode(inode); |
132 |
|
133 |
if (!list_empty(&ff->ff_list)) { |
134 |
down_write(&fi->write_sem); |
135 |
list_del(&ff->ff_list); |
136 |
up_write(&fi->write_sem); |
137 |
} |
138 |
|
139 |
inarg = &req->misc.release_in; |
140 |
inarg->fh = ff->fh; |
141 |
inarg->flags = file->f_flags & ~O_EXCL; |
142 |
req->in.h.opcode = FUSE_RELEASE; |
143 |
req->in.h.ino = inode->i_ino; |
144 |
req->in.numargs = 1; |
145 |
req->in.args[0].size = sizeof(struct fuse_release_in); |
146 |
req->in.args[0].value = inarg; |
147 |
request_send(fc, req); |
148 |
fuse_put_request(fc, req); |
149 |
kfree(ff); |
150 |
up(&inode->i_sem); |
151 |
|
152 |
/* Return value is ignored by VFS */ |
153 |
return 0; |
154 |
} |
155 |
|
156 |
static int fuse_flush(struct file *file) |
157 |
{ |
158 |
struct inode *inode = file->f_dentry->d_inode; |
159 |
struct fuse_conn *fc = INO_FC(inode); |
160 |
struct fuse_file *ff = file->private_data; |
161 |
struct fuse_req *req; |
162 |
struct fuse_flush_in inarg; |
163 |
int err; |
164 |
|
165 |
if (fc->no_flush) |
166 |
return 0; |
167 |
|
168 |
req = fuse_get_request(fc); |
169 |
if (!req) |
170 |
return -EINTR; |
171 |
|
172 |
memset(&inarg, 0, sizeof(inarg)); |
173 |
inarg.fh = ff->fh; |
174 |
req->in.h.opcode = FUSE_FLUSH; |
175 |
req->in.h.ino = inode->i_ino; |
176 |
req->in.numargs = 1; |
177 |
req->in.args[0].size = sizeof(inarg); |
178 |
req->in.args[0].value = &inarg; |
179 |
request_send(fc, req); |
180 |
err = req->out.h.error; |
181 |
if (err == -ENOSYS) { |
182 |
fc->no_flush = 1; |
183 |
err = 0; |
184 |
} |
185 |
fuse_put_request(fc, req); |
186 |
return err; |
187 |
} |
188 |
|
189 |
static int fuse_fsync(struct file *file, struct dentry *de, int datasync) |
190 |
{ |
191 |
struct inode *inode = de->d_inode; |
192 |
struct fuse_inode *fi = INO_FI(inode); |
193 |
struct fuse_conn *fc = INO_FC(inode); |
194 |
struct fuse_file *ff = file->private_data; |
195 |
struct fuse_req *req; |
196 |
struct fuse_fsync_in inarg; |
197 |
int err; |
198 |
|
199 |
if (fc->no_fsync) |
200 |
return 0; |
201 |
|
202 |
req = fuse_get_request(fc); |
203 |
if (!req) |
204 |
return -ERESTARTSYS; |
205 |
|
206 |
/* Make sure all writes to this inode are completed before |
207 |
issuing the FSYNC request */ |
208 |
down_write(&fi->write_sem); |
209 |
up_write(&fi->write_sem); |
210 |
|
211 |
memset(&inarg, 0, sizeof(inarg)); |
212 |
inarg.fh = ff->fh; |
213 |
inarg.datasync = datasync; |
214 |
req->in.h.opcode = FUSE_FSYNC; |
215 |
req->in.h.ino = inode->i_ino; |
216 |
req->in.numargs = 1; |
217 |
req->in.args[0].size = sizeof(inarg); |
218 |
req->in.args[0].value = &inarg; |
219 |
request_send(fc, req); |
220 |
err = req->out.h.error; |
221 |
if (err == -ENOSYS) { |
222 |
fc->no_fsync = 1; |
223 |
err = 0; |
224 |
} |
225 |
fuse_put_request(fc, req); |
226 |
return err; |
227 |
} |
228 |
|
229 |
static ssize_t fuse_send_read(struct file *file, struct inode *inode, |
230 |
char *buf, loff_t pos, size_t count) |
231 |
{ |
232 |
struct fuse_conn *fc = INO_FC(inode); |
233 |
struct fuse_file *ff = file->private_data; |
234 |
struct fuse_req *req; |
235 |
struct fuse_read_in inarg; |
236 |
ssize_t res; |
237 |
|
238 |
req = fuse_get_request(fc); |
239 |
if (!req) |
240 |
return -ERESTARTSYS; |
241 |
|
242 |
memset(&inarg, 0, sizeof(inarg)); |
243 |
inarg.fh = ff->fh; |
244 |
inarg.offset = pos; |
245 |
inarg.size = count; |
246 |
req->in.h.opcode = FUSE_READ; |
247 |
req->in.h.ino = inode->i_ino; |
248 |
req->in.numargs = 1; |
249 |
req->in.args[0].size = sizeof(inarg); |
250 |
req->in.args[0].value = &inarg; |
251 |
req->out.argvar = 1; |
252 |
req->out.numargs = 1; |
253 |
req->out.args[0].size = count; |
254 |
req->out.args[0].value = buf; |
255 |
request_send(fc, req); |
256 |
res = req->out.h.error; |
257 |
if (!res) |
258 |
res = req->out.args[0].size; |
259 |
fuse_put_request(fc, req); |
260 |
return res; |
261 |
} |
262 |
|
263 |
|
264 |
static int fuse_readpage(struct file *file, struct page *page) |
265 |
{ |
266 |
struct inode *inode = page->mapping->host; |
267 |
char *buffer; |
268 |
ssize_t res; |
269 |
loff_t pos; |
270 |
|
271 |
pos = (loff_t) page->index << PAGE_CACHE_SHIFT; |
272 |
buffer = kmap(page); |
273 |
res = fuse_send_read(file, inode, buffer, pos, PAGE_CACHE_SIZE); |
274 |
if (res >= 0) { |
275 |
if (res < PAGE_CACHE_SIZE) |
276 |
memset(buffer + res, 0, PAGE_CACHE_SIZE - res); |
277 |
flush_dcache_page(page); |
278 |
SetPageUptodate(page); |
279 |
res = 0; |
280 |
} |
281 |
kunmap(page); |
282 |
unlock_page(page); |
283 |
return res; |
284 |
} |
285 |
|
286 |
#ifdef KERNEL_2_6 |
287 |
|
288 |
static int read_pages_copyout(struct fuse_req *req, const char *buf, |
289 |
size_t nbytes) |
290 |
{ |
291 |
unsigned i; |
292 |
unsigned long base_index = req->pages[0]->index; |
293 |
for (i = 0; i < req->num_pages; i++) { |
294 |
struct page *page = req->pages[i]; |
295 |
unsigned long offset; |
296 |
unsigned count; |
297 |
char *tmpbuf; |
298 |
int err; |
299 |
|
300 |
offset = (page->index - base_index) * PAGE_CACHE_SIZE; |
301 |
if (offset >= nbytes) |
302 |
count = 0; |
303 |
else if (offset + PAGE_CACHE_SIZE <= nbytes) |
304 |
count = PAGE_CACHE_SIZE; |
305 |
else |
306 |
count = nbytes - offset; |
307 |
|
308 |
tmpbuf = kmap(page); |
309 |
err = 0; |
310 |
if (count) |
311 |
err = copy_from_user(tmpbuf, buf + offset, count); |
312 |
if (count < PAGE_CACHE_SIZE) |
313 |
memset(tmpbuf + count, 0, PAGE_CACHE_SIZE - count); |
314 |
kunmap(page); |
315 |
if (err) |
316 |
return -EFAULT; |
317 |
|
318 |
flush_dcache_page(page); |
319 |
SetPageUptodate(page); |
320 |
} |
321 |
return 0; |
322 |
} |
323 |
|
324 |
static void read_pages_end(struct fuse_conn *fc, struct fuse_req *req) |
325 |
{ |
326 |
unsigned i; |
327 |
|
328 |
for (i = 0; i < req->num_pages; i++) |
329 |
unlock_page(req->pages[i]); |
330 |
|
331 |
fuse_put_request(fc, req); |
332 |
} |
333 |
|
334 |
static void fuse_send_readpages(struct fuse_req *req, struct file *file, |
335 |
struct inode *inode) |
336 |
{ |
337 |
struct fuse_conn *fc = INO_FC(inode); |
338 |
struct fuse_file *ff = file->private_data; |
339 |
struct fuse_read_in *inarg; |
340 |
loff_t pos; |
341 |
unsigned numpages; |
342 |
|
343 |
pos = (loff_t) req->pages[0]->index << PAGE_CACHE_SHIFT; |
344 |
/* Allow for holes between the pages */ |
345 |
numpages = req->pages[req->num_pages - 1]->index + 1 |
346 |
- req->pages[0]->index; |
347 |
|
348 |
inarg = &req->misc.read_in; |
349 |
inarg->fh = ff->fh; |
350 |
inarg->offset = pos; |
351 |
inarg->size = numpages * PAGE_CACHE_SIZE; |
352 |
req->in.h.opcode = FUSE_READ; |
353 |
req->in.h.ino = inode->i_ino; |
354 |
req->in.numargs = 1; |
355 |
req->in.args[0].size = sizeof(struct fuse_read_in); |
356 |
req->in.args[0].value = inarg; |
357 |
req->copy_out = read_pages_copyout; |
358 |
request_send_nonblock(fc, req, read_pages_end, NULL); |
359 |
} |
360 |
|
361 |
struct fuse_readpages_data { |
362 |
struct fuse_req *req; |
363 |
struct file *file; |
364 |
struct inode *inode; |
365 |
}; |
366 |
|
367 |
static int fuse_readpages_fill(void *_data, struct page *page) |
368 |
{ |
369 |
struct fuse_readpages_data *data = _data; |
370 |
struct fuse_req *req = data->req; |
371 |
struct inode *inode = data->inode; |
372 |
struct fuse_conn *fc = INO_FC(inode); |
373 |
|
374 |
if (req->num_pages && |
375 |
(req->num_pages == FUSE_MAX_PAGES_PER_REQ || |
376 |
(req->num_pages + 1) * PAGE_CACHE_SIZE > fc->max_read || |
377 |
req->pages[req->num_pages - 1]->index + 1 != page->index)) { |
378 |
struct fuse_conn *fc = INO_FC(page->mapping->host); |
379 |
fuse_send_readpages(req, data->file, inode); |
380 |
data->req = req = fuse_get_request(fc); |
381 |
} |
382 |
req->pages[req->num_pages] = page; |
383 |
req->num_pages ++; |
384 |
return 0; |
385 |
} |
386 |
|
387 |
static int fuse_readpages(struct file *file, struct address_space *mapping, |
388 |
struct list_head *pages, unsigned nr_pages) |
389 |
{ |
390 |
struct inode *inode = mapping->host; |
391 |
struct fuse_conn *fc = INO_FC(inode); |
392 |
struct fuse_readpages_data data; |
393 |
|
394 |
data.req = fuse_get_request(fc); |
395 |
data.file = file; |
396 |
data.inode = inode; |
397 |
|
398 |
read_cache_pages(mapping, pages, fuse_readpages_fill, &data); |
399 |
if (data.req->num_pages) |
400 |
fuse_send_readpages(data.req, file, inode); |
401 |
else |
402 |
fuse_put_request(fc, data.req); |
403 |
|
404 |
return 0; |
405 |
} |
406 |
#endif |
407 |
|
408 |
#ifndef KERNEL_2_6 |
409 |
static int fuse_is_block_uptodate(struct inode *inode, size_t bl_index) |
410 |
{ |
411 |
size_t index = bl_index << FUSE_BLOCK_PAGE_SHIFT; |
412 |
size_t end_index = ((bl_index + 1) << FUSE_BLOCK_PAGE_SHIFT) - 1; |
413 |
size_t file_end_index = i_size_read(inode) >> PAGE_CACHE_SHIFT; |
414 |
|
415 |
if (end_index > file_end_index) |
416 |
end_index = file_end_index; |
417 |
|
418 |
for (; index <= end_index; index++) { |
419 |
struct page *page = find_get_page(inode->i_mapping, index); |
420 |
|
421 |
if (!page) |
422 |
return 0; |
423 |
|
424 |
if (!PageUptodate(page)) { |
425 |
page_cache_release(page); |
426 |
return 0; |
427 |
} |
428 |
|
429 |
page_cache_release(page); |
430 |
} |
431 |
|
432 |
return 1; |
433 |
} |
434 |
|
435 |
|
436 |
static int fuse_cache_block(struct inode *inode, char *bl_buf, |
437 |
size_t bl_index) |
438 |
{ |
439 |
size_t start_index = bl_index << FUSE_BLOCK_PAGE_SHIFT; |
440 |
size_t end_index = ((bl_index + 1) << FUSE_BLOCK_PAGE_SHIFT) - 1; |
441 |
size_t file_end_index = i_size_read(inode) >> PAGE_CACHE_SHIFT; |
442 |
|
443 |
int i; |
444 |
|
445 |
if (end_index > file_end_index) |
446 |
end_index = file_end_index; |
447 |
|
448 |
for (i = 0; start_index + i <= end_index; i++) { |
449 |
size_t index = start_index + i; |
450 |
struct page *page; |
451 |
char *buffer; |
452 |
|
453 |
page = grab_cache_page(inode->i_mapping, index); |
454 |
if (!page) |
455 |
return -1; |
456 |
|
457 |
if (!PageUptodate(page)) { |
458 |
buffer = kmap(page); |
459 |
memcpy(buffer, bl_buf + i * PAGE_CACHE_SIZE, |
460 |
PAGE_CACHE_SIZE); |
461 |
flush_dcache_page(page); |
462 |
SetPageUptodate(page); |
463 |
kunmap(page); |
464 |
} |
465 |
|
466 |
unlock_page(page); |
467 |
page_cache_release(page); |
468 |
} |
469 |
|
470 |
return 0; |
471 |
} |
472 |
|
473 |
static int fuse_file_read_block(struct file *file, struct inode *inode, |
474 |
char *bl_buf, size_t bl_index) |
475 |
{ |
476 |
ssize_t res; |
477 |
loff_t offset; |
478 |
|
479 |
offset = (loff_t) bl_index << FUSE_BLOCK_SHIFT; |
480 |
res = fuse_send_read(file, inode, bl_buf, offset, FUSE_BLOCK_SIZE); |
481 |
if (res >= 0) { |
482 |
if (res < FUSE_BLOCK_SIZE) |
483 |
memset(bl_buf + res, 0, FUSE_BLOCK_SIZE - res); |
484 |
res = 0; |
485 |
} |
486 |
return res; |
487 |
} |
488 |
|
489 |
static void fuse_file_bigread(struct file *file, struct inode *inode, |
490 |
loff_t pos, size_t count) |
491 |
{ |
492 |
size_t bl_index = pos >> FUSE_BLOCK_SHIFT; |
493 |
size_t bl_end_index = (pos + count) >> FUSE_BLOCK_SHIFT; |
494 |
size_t bl_file_end_index = i_size_read(inode) >> FUSE_BLOCK_SHIFT; |
495 |
|
496 |
if (bl_end_index > bl_file_end_index) |
497 |
bl_end_index = bl_file_end_index; |
498 |
|
499 |
while (bl_index <= bl_end_index) { |
500 |
int res; |
501 |
char *bl_buf = kmalloc(FUSE_BLOCK_SIZE, GFP_KERNEL); |
502 |
if (!bl_buf) |
503 |
break; |
504 |
res = fuse_is_block_uptodate(inode, bl_index); |
505 |
if (!res) |
506 |
res = fuse_file_read_block(file, inode, bl_buf, |
507 |
bl_index); |
508 |
if (!res) |
509 |
fuse_cache_block(inode, bl_buf, bl_index); |
510 |
kfree(bl_buf); |
511 |
bl_index++; |
512 |
} |
513 |
} |
514 |
#endif |
515 |
|
516 |
static ssize_t fuse_read(struct file *file, char *buf, size_t count, |
517 |
loff_t *ppos) |
518 |
{ |
519 |
struct inode *inode = file->f_dentry->d_inode; |
520 |
struct fuse_conn *fc = INO_FC(inode); |
521 |
char *tmpbuf; |
522 |
ssize_t res = 0; |
523 |
loff_t pos = *ppos; |
524 |
unsigned int max_read = count < fc->max_read ? count : fc->max_read; |
525 |
|
526 |
do { |
527 |
tmpbuf = kmalloc(max_read, GFP_KERNEL); |
528 |
if (tmpbuf) |
529 |
break; |
530 |
|
531 |
max_read /= 2; |
532 |
} while (max_read > PAGE_CACHE_SIZE / 4); |
533 |
if (!tmpbuf) |
534 |
return -ENOMEM; |
535 |
|
536 |
while (count) { |
537 |
size_t nbytes = count < max_read ? count : max_read; |
538 |
ssize_t res1; |
539 |
res1 = fuse_send_read(file, inode, tmpbuf, pos, nbytes); |
540 |
if (res1 < 0) { |
541 |
if (!res) |
542 |
res = res1; |
543 |
break; |
544 |
} |
545 |
res += res1; |
546 |
if (copy_to_user(buf, tmpbuf, res1)) { |
547 |
res = -EFAULT; |
548 |
break; |
549 |
} |
550 |
count -= res1; |
551 |
buf += res1; |
552 |
pos += res1; |
553 |
if (res1 < nbytes) |
554 |
break; |
555 |
} |
556 |
kfree(tmpbuf); |
557 |
|
558 |
if (res > 0) |
559 |
*ppos += res; |
560 |
|
561 |
return res; |
562 |
} |
563 |
|
564 |
static ssize_t fuse_file_read(struct file *file, char *buf, |
565 |
size_t count, loff_t * ppos) |
566 |
{ |
567 |
struct inode *inode = file->f_dentry->d_inode; |
568 |
struct fuse_conn *fc = INO_FC(inode); |
569 |
ssize_t res; |
570 |
|
571 |
if (fc->flags & FUSE_DIRECT_IO) { |
572 |
res = fuse_read(file, buf, count, ppos); |
573 |
} |
574 |
else { |
575 |
#ifndef KERNEL_2_6 |
576 |
if (fc->flags & FUSE_LARGE_READ) { |
577 |
down(&inode->i_sem); |
578 |
fuse_file_bigread(file, inode, *ppos, count); |
579 |
up(&inode->i_sem); |
580 |
} |
581 |
#endif |
582 |
res = generic_file_read(file, buf, count, ppos); |
583 |
} |
584 |
|
585 |
return res; |
586 |
} |
587 |
|
588 |
static ssize_t fuse_send_write(struct fuse_req *req, int writepage, |
589 |
struct fuse_file *ff, struct inode *inode, |
590 |
const char *buf, loff_t pos, size_t count) |
591 |
{ |
592 |
struct fuse_conn *fc = INO_FC(inode); |
593 |
struct fuse_write_in inarg; |
594 |
struct fuse_write_out outarg; |
595 |
ssize_t res; |
596 |
|
597 |
memset(&inarg, 0, sizeof(inarg)); |
598 |
inarg.writepage = writepage; |
599 |
inarg.fh = ff->fh; |
600 |
inarg.offset = pos; |
601 |
inarg.size = count; |
602 |
req->in.h.opcode = FUSE_WRITE; |
603 |
req->in.h.ino = inode->i_ino; |
604 |
req->in.numargs = 2; |
605 |
req->in.args[0].size = sizeof(inarg); |
606 |
req->in.args[0].value = &inarg; |
607 |
req->in.args[1].size = count; |
608 |
req->in.args[1].value = buf; |
609 |
req->out.numargs = 1; |
610 |
req->out.args[0].size = sizeof(outarg); |
611 |
req->out.args[0].value = &outarg; |
612 |
request_send(fc, req); |
613 |
res = req->out.h.error; |
614 |
if (!res) |
615 |
return outarg.size; |
616 |
else |
617 |
return res; |
618 |
} |
619 |
|
620 |
static int write_buffer(struct inode *inode, struct file *file, |
621 |
struct page *page, unsigned offset, size_t count) |
622 |
{ |
623 |
struct fuse_conn *fc = INO_FC(inode); |
624 |
struct fuse_file *ff = file->private_data; |
625 |
char *buffer; |
626 |
ssize_t res; |
627 |
loff_t pos; |
628 |
struct fuse_req *req; |
629 |
|
630 |
req = fuse_get_request(fc); |
631 |
if (!req) |
632 |
return -ERESTARTSYS; |
633 |
|
634 |
pos = ((loff_t) page->index << PAGE_CACHE_SHIFT) + offset; |
635 |
buffer = kmap(page); |
636 |
res = fuse_send_write(req, 0, ff, inode, buffer + offset, pos, count); |
637 |
fuse_put_request(fc, req); |
638 |
if (res >= 0) { |
639 |
if (res < count) { |
640 |
printk("fuse: short write\n"); |
641 |
res = -EPROTO; |
642 |
} else |
643 |
res = 0; |
644 |
} |
645 |
kunmap(page); |
646 |
if (res) |
647 |
SetPageError(page); |
648 |
return res; |
649 |
} |
650 |
|
651 |
static int get_write_count(struct inode *inode, struct page *page) |
652 |
{ |
653 |
unsigned long end_index; |
654 |
loff_t size = i_size_read(inode); |
655 |
int count; |
656 |
|
657 |
end_index = size >> PAGE_CACHE_SHIFT; |
658 |
if (page->index < end_index) |
659 |
count = PAGE_CACHE_SIZE; |
660 |
else { |
661 |
count = size & (PAGE_CACHE_SIZE - 1); |
662 |
if (page->index > end_index || count == 0) |
663 |
return 0; |
664 |
} |
665 |
return count; |
666 |
} |
667 |
|
668 |
|
669 |
static int write_page_block(struct inode *inode, struct page *page) |
670 |
{ |
671 |
struct fuse_conn *fc = INO_FC(inode); |
672 |
struct fuse_inode *fi = INO_FI(inode); |
673 |
char *buffer; |
674 |
ssize_t res; |
675 |
loff_t pos; |
676 |
unsigned count; |
677 |
struct fuse_req *req; |
678 |
|
679 |
req = fuse_get_request(fc); |
680 |
if (!req) |
681 |
return -ERESTARTSYS; |
682 |
|
683 |
down_read(&fi->write_sem); |
684 |
count = get_write_count(inode, page); |
685 |
res = 0; |
686 |
if (count) { |
687 |
struct fuse_file *ff; |
688 |
BUG_ON(list_empty(&fi->write_files)); |
689 |
ff = list_entry(fi->write_files.next, struct fuse_file, ff_list); |
690 |
pos = ((loff_t) page->index << PAGE_CACHE_SHIFT); |
691 |
buffer = kmap(page); |
692 |
res = fuse_send_write(req, 1, ff, inode, buffer, pos, count); |
693 |
if (res >= 0) { |
694 |
if (res < count) { |
695 |
printk("fuse: short write\n"); |
696 |
res = -EPROTO; |
697 |
} else |
698 |
res = 0; |
699 |
} |
700 |
} |
701 |
up_read(&fi->write_sem); |
702 |
fuse_put_request(fc, req); |
703 |
kunmap(page); |
704 |
if (res) |
705 |
SetPageError(page); |
706 |
return res; |
707 |
} |
708 |
|
709 |
|
710 |
#ifdef KERNEL_2_6 |
711 |
|
712 |
|
713 |
static void write_page_nonblock_end(struct fuse_conn *fc, struct fuse_req *req) |
714 |
{ |
715 |
struct page *page = (struct page *) req->data; |
716 |
struct inode *inode = page->mapping->host; |
717 |
struct fuse_inode *fi = INO_FI(inode); |
718 |
struct fuse_write_out *outarg = req->out.args[0].value; |
719 |
if (!req->out.h.error && outarg->size != req->in.args[1].size) { |
720 |
printk("fuse: short write\n"); |
721 |
req->out.h.error = -EPROTO; |
722 |
} |
723 |
|
724 |
if (req->out.h.error) { |
725 |
SetPageError(page); |
726 |
if (req->out.h.error == -ENOSPC) |
727 |
set_bit(AS_ENOSPC, &page->mapping->flags); |
728 |
else |
729 |
set_bit(AS_EIO, &page->mapping->flags); |
730 |
} |
731 |
up_read(&fi->write_sem); |
732 |
|
733 |
end_page_writeback(page); |
734 |
kunmap(page); |
735 |
fuse_put_request(fc, req); |
736 |
} |
737 |
|
738 |
static void send_write_nonblock(struct fuse_req *req, struct inode *inode, |
739 |
struct page *page, unsigned count) |
740 |
{ |
741 |
struct fuse_conn *fc = INO_FC(inode); |
742 |
struct fuse_inode *fi = INO_FI(inode); |
743 |
struct fuse_write_in *inarg; |
744 |
struct fuse_file *ff; |
745 |
char *buffer; |
746 |
|
747 |
BUG_ON(list_empty(&fi->write_files)); |
748 |
ff = list_entry(fi->write_files.next, struct fuse_file, ff_list); |
749 |
|
750 |
inarg = &req->misc.write.in; |
751 |
buffer = kmap(page); |
752 |
inarg->writepage = 1; |
753 |
inarg->fh = ff->fh; |
754 |
inarg->offset = ((loff_t) page->index << PAGE_CACHE_SHIFT); |
755 |
inarg->size = count; |
756 |
req->in.h.opcode = FUSE_WRITE; |
757 |
req->in.h.ino = inode->i_ino; |
758 |
req->in.numargs = 2; |
759 |
req->in.args[0].size = sizeof(struct fuse_write_in); |
760 |
req->in.args[0].value = inarg; |
761 |
req->in.args[1].size = count; |
762 |
req->in.args[1].value = buffer; |
763 |
req->out.numargs = 1; |
764 |
req->out.args[0].size = sizeof(struct fuse_write_out); |
765 |
req->out.args[0].value = &req->misc.write.out; |
766 |
request_send_nonblock(fc, req, write_page_nonblock_end, page); |
767 |
} |
768 |
|
769 |
static int write_page_nonblock(struct inode *inode, struct page *page) |
770 |
{ |
771 |
struct fuse_conn *fc = INO_FC(inode); |
772 |
struct fuse_inode *fi = INO_FI(inode); |
773 |
struct fuse_req *req; |
774 |
int err; |
775 |
|
776 |
err = -EWOULDBLOCK; |
777 |
req = fuse_get_request_nonblock(fc); |
778 |
if (req) { |
779 |
if (down_read_trylock(&fi->write_sem)) { |
780 |
unsigned count; |
781 |
err = 0; |
782 |
count = get_write_count(inode, page); |
783 |
if (count) { |
784 |
SetPageWriteback(page); |
785 |
send_write_nonblock(req, inode, page, count); |
786 |
return 0; |
787 |
} |
788 |
up_read(&fi->write_sem); |
789 |
} |
790 |
fuse_put_request(fc, req); |
791 |
} |
792 |
return err; |
793 |
} |
794 |
|
795 |
static int fuse_writepage(struct page *page, struct writeback_control *wbc) |
796 |
{ |
797 |
int err; |
798 |
struct inode *inode = page->mapping->host; |
799 |
|
800 |
if (wbc->nonblocking) { |
801 |
err = write_page_nonblock(inode, page); |
802 |
if (err == -EWOULDBLOCK) { |
803 |
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,6) |
804 |
redirty_page_for_writepage(wbc, page); |
805 |
#else |
806 |
__set_page_dirty_nobuffers(page); |
807 |
#endif |
808 |
err = 0; |
809 |
} |
810 |
} else |
811 |
err = write_page_block(inode, page); |
812 |
|
813 |
unlock_page(page); |
814 |
return err; |
815 |
} |
816 |
#else |
817 |
static int fuse_writepage(struct page *page) |
818 |
{ |
819 |
int err = write_page_block(page->mapping->host, page); |
820 |
unlock_page(page); |
821 |
return err; |
822 |
} |
823 |
#endif |
824 |
|
825 |
static int fuse_prepare_write(struct file *file, struct page *page, |
826 |
unsigned offset, unsigned to) |
827 |
{ |
828 |
/* No op */ |
829 |
return 0; |
830 |
} |
831 |
|
832 |
static int fuse_commit_write(struct file *file, struct page *page, |
833 |
unsigned offset, unsigned to) |
834 |
{ |
835 |
int err; |
836 |
struct inode *inode = page->mapping->host; |
837 |
|
838 |
err = write_buffer(inode, file, page, offset, to - offset); |
839 |
if (!err) { |
840 |
loff_t pos = (page->index << PAGE_CACHE_SHIFT) + to; |
841 |
if (pos > i_size_read(inode)) |
842 |
i_size_write(inode, pos); |
843 |
|
844 |
if (offset == 0 && to == PAGE_CACHE_SIZE) { |
845 |
#ifdef KERNEL_2_6 |
846 |
clear_page_dirty(page); |
847 |
#else |
848 |
ClearPageDirty(page); |
849 |
#endif |
850 |
SetPageUptodate(page); |
851 |
} |
852 |
|
853 |
} |
854 |
return err; |
855 |
} |
856 |
|
857 |
static ssize_t fuse_write(struct file *file, const char *buf, size_t count, |
858 |
loff_t *ppos) |
859 |
{ |
860 |
struct inode *inode = file->f_dentry->d_inode; |
861 |
struct fuse_conn *fc = INO_FC(inode); |
862 |
struct fuse_file *ff = file->private_data; |
863 |
char *tmpbuf; |
864 |
ssize_t res = 0; |
865 |
loff_t pos = *ppos; |
866 |
struct fuse_req *req; |
867 |
|
868 |
req = fuse_get_request(fc); |
869 |
if (!req) |
870 |
return -ERESTARTSYS; |
871 |
|
872 |
tmpbuf = kmalloc(count < fc->max_write ? count : fc->max_write, |
873 |
GFP_KERNEL); |
874 |
if (!tmpbuf) { |
875 |
fuse_put_request(fc, req); |
876 |
return -ENOMEM; |
877 |
} |
878 |
|
879 |
while (count) { |
880 |
size_t nbytes = count < fc->max_write ? count : fc->max_write; |
881 |
ssize_t res1; |
882 |
if (copy_from_user(tmpbuf, buf, nbytes)) { |
883 |
res = -EFAULT; |
884 |
break; |
885 |
} |
886 |
res1 = fuse_send_write(req, 0, ff, inode, tmpbuf, pos, nbytes); |
887 |
if (res1 < 0) { |
888 |
res = res1; |
889 |
break; |
890 |
} |
891 |
res += res1; |
892 |
count -= res1; |
893 |
buf += res1; |
894 |
pos += res1; |
895 |
if (res1 < nbytes) |
896 |
break; |
897 |
|
898 |
if (count) |
899 |
fuse_reset_request(req); |
900 |
} |
901 |
kfree(tmpbuf); |
902 |
fuse_put_request(fc, req); |
903 |
|
904 |
if (res > 0) { |
905 |
if (pos > i_size_read(inode)) |
906 |
i_size_write(inode, pos); |
907 |
*ppos = pos; |
908 |
} |
909 |
|
910 |
return res; |
911 |
} |
912 |
|
913 |
static ssize_t fuse_file_write(struct file *file, const char *buf, |
914 |
size_t count, loff_t *ppos) |
915 |
{ |
916 |
struct inode *inode = file->f_dentry->d_inode; |
917 |
struct fuse_conn *fc = INO_FC(inode); |
918 |
|
919 |
if (fc->flags & FUSE_DIRECT_IO) { |
920 |
ssize_t res; |
921 |
down(&inode->i_sem); |
922 |
res = fuse_write(file, buf, count, ppos); |
923 |
up(&inode->i_sem); |
924 |
return res; |
925 |
} |
926 |
else |
927 |
return generic_file_write(file, buf, count, ppos); |
928 |
} |
929 |
|
930 |
static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma) |
931 |
{ |
932 |
struct inode *inode = file->f_dentry->d_inode; |
933 |
struct fuse_conn *fc = INO_FC(inode); |
934 |
|
935 |
if (fc->flags & FUSE_DIRECT_IO) |
936 |
return -ENODEV; |
937 |
else { |
938 |
if ((vma->vm_flags & (VM_WRITE | VM_SHARED)) == |
939 |
(VM_WRITE | VM_SHARED)) { |
940 |
struct fuse_inode *fi = INO_FI(inode); |
941 |
struct fuse_file *ff = file->private_data; |
942 |
|
943 |
if (!user_mmap && current->uid != 0) |
944 |
return -EPERM; |
945 |
|
946 |
down_write(&fi->write_sem); |
947 |
if (list_empty(&ff->ff_list)) |
948 |
list_add(&ff->ff_list, &fi->write_files); |
949 |
up_write(&fi->write_sem); |
950 |
} |
951 |
return generic_file_mmap(file, vma); |
952 |
} |
953 |
} |
954 |
|
955 |
static struct file_operations fuse_file_operations = { |
956 |
.read = fuse_file_read, |
957 |
.write = fuse_file_write, |
958 |
.mmap = fuse_file_mmap, |
959 |
.open = fuse_open, |
960 |
.flush = fuse_flush, |
961 |
.release = fuse_release, |
962 |
.fsync = fuse_fsync, |
963 |
#ifdef KERNEL_2_6 |
964 |
.sendfile = generic_file_sendfile, |
965 |
#endif |
966 |
}; |
967 |
|
968 |
static struct address_space_operations fuse_file_aops = { |
969 |
.readpage = fuse_readpage, |
970 |
.writepage = fuse_writepage, |
971 |
.prepare_write = fuse_prepare_write, |
972 |
.commit_write = fuse_commit_write, |
973 |
#ifdef KERNEL_2_6 |
974 |
.readpages = fuse_readpages, |
975 |
.set_page_dirty = __set_page_dirty_nobuffers, |
976 |
#endif |
977 |
}; |
978 |
|
979 |
void fuse_init_file_inode(struct inode *inode) |
980 |
{ |
981 |
inode->i_fop = &fuse_file_operations; |
982 |
inode->i_data.a_ops = &fuse_file_aops; |
983 |
} |
984 |
|
985 |
/* |
986 |
* Local Variables: |
987 |
* indent-tabs-mode: t |
988 |
* c-basic-offset: 8 |
989 |
* End: |
990 |
*/ |