Merge master.kernel.org:/pub/scm/linux/kernel/git/gregkh/driver-2.6
[linux-2.6] / fs / fuse / file.c
1 /*
2   FUSE: Filesystem in Userspace
3   Copyright (C) 2001-2006  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 const struct file_operations fuse_direct_io_file_operations;
16
17 static int fuse_send_open(struct inode *inode, struct file *file, int isdir,
18                           struct fuse_open_out *outargp)
19 {
20         struct fuse_conn *fc = get_fuse_conn(inode);
21         struct fuse_open_in inarg;
22         struct fuse_req *req;
23         int err;
24
25         req = fuse_get_req(fc);
26         if (IS_ERR(req))
27                 return PTR_ERR(req);
28
29         memset(&inarg, 0, sizeof(inarg));
30         inarg.flags = file->f_flags & ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);
31         req->in.h.opcode = isdir ? FUSE_OPENDIR : FUSE_OPEN;
32         req->in.h.nodeid = get_node_id(inode);
33         req->in.numargs = 1;
34         req->in.args[0].size = sizeof(inarg);
35         req->in.args[0].value = &inarg;
36         req->out.numargs = 1;
37         req->out.args[0].size = sizeof(*outargp);
38         req->out.args[0].value = outargp;
39         request_send(fc, req);
40         err = req->out.h.error;
41         fuse_put_request(fc, req);
42
43         return err;
44 }
45
46 struct fuse_file *fuse_file_alloc(void)
47 {
48         struct fuse_file *ff;
49         ff = kmalloc(sizeof(struct fuse_file), GFP_KERNEL);
50         if (ff) {
51                 ff->reserved_req = fuse_request_alloc();
52                 if (!ff->reserved_req) {
53                         kfree(ff);
54                         ff = NULL;
55                 }
56         }
57         return ff;
58 }
59
60 void fuse_file_free(struct fuse_file *ff)
61 {
62         fuse_request_free(ff->reserved_req);
63         kfree(ff);
64 }
65
66 void fuse_finish_open(struct inode *inode, struct file *file,
67                       struct fuse_file *ff, struct fuse_open_out *outarg)
68 {
69         if (outarg->open_flags & FOPEN_DIRECT_IO)
70                 file->f_op = &fuse_direct_io_file_operations;
71         if (!(outarg->open_flags & FOPEN_KEEP_CACHE))
72                 invalidate_inode_pages(inode->i_mapping);
73         ff->fh = outarg->fh;
74         file->private_data = ff;
75 }
76
77 int fuse_open_common(struct inode *inode, struct file *file, int isdir)
78 {
79         struct fuse_open_out outarg;
80         struct fuse_file *ff;
81         int err;
82
83         /* VFS checks this, but only _after_ ->open() */
84         if (file->f_flags & O_DIRECT)
85                 return -EINVAL;
86
87         err = generic_file_open(inode, file);
88         if (err)
89                 return err;
90
91         /* If opening the root node, no lookup has been performed on
92            it, so the attributes must be refreshed */
93         if (get_node_id(inode) == FUSE_ROOT_ID) {
94                 err = fuse_do_getattr(inode);
95                 if (err)
96                         return err;
97         }
98
99         ff = fuse_file_alloc();
100         if (!ff)
101                 return -ENOMEM;
102
103         err = fuse_send_open(inode, file, isdir, &outarg);
104         if (err)
105                 fuse_file_free(ff);
106         else {
107                 if (isdir)
108                         outarg.open_flags &= ~FOPEN_DIRECT_IO;
109                 fuse_finish_open(inode, file, ff, &outarg);
110         }
111
112         return err;
113 }
114
115 struct fuse_req *fuse_release_fill(struct fuse_file *ff, u64 nodeid, int flags,
116                                    int opcode)
117 {
118         struct fuse_req *req = ff->reserved_req;
119         struct fuse_release_in *inarg = &req->misc.release_in;
120
121         inarg->fh = ff->fh;
122         inarg->flags = flags;
123         req->in.h.opcode = opcode;
124         req->in.h.nodeid = nodeid;
125         req->in.numargs = 1;
126         req->in.args[0].size = sizeof(struct fuse_release_in);
127         req->in.args[0].value = inarg;
128         kfree(ff);
129
130         return req;
131 }
132
133 int fuse_release_common(struct inode *inode, struct file *file, int isdir)
134 {
135         struct fuse_file *ff = file->private_data;
136         if (ff) {
137                 struct fuse_conn *fc = get_fuse_conn(inode);
138                 struct fuse_req *req;
139
140                 req = fuse_release_fill(ff, get_node_id(inode), file->f_flags,
141                                         isdir ? FUSE_RELEASEDIR : FUSE_RELEASE);
142
143                 /* Hold vfsmount and dentry until release is finished */
144                 req->vfsmount = mntget(file->f_path.mnt);
145                 req->dentry = dget(file->f_path.dentry);
146                 request_send_background(fc, req);
147         }
148
149         /* Return value is ignored by VFS */
150         return 0;
151 }
152
153 static int fuse_open(struct inode *inode, struct file *file)
154 {
155         return fuse_open_common(inode, file, 0);
156 }
157
158 static int fuse_release(struct inode *inode, struct file *file)
159 {
160         return fuse_release_common(inode, file, 0);
161 }
162
163 /*
164  * Scramble the ID space with XTEA, so that the value of the files_struct
165  * pointer is not exposed to userspace.
166  */
167 static u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id)
168 {
169         u32 *k = fc->scramble_key;
170         u64 v = (unsigned long) id;
171         u32 v0 = v;
172         u32 v1 = v >> 32;
173         u32 sum = 0;
174         int i;
175
176         for (i = 0; i < 32; i++) {
177                 v0 += ((v1 << 4 ^ v1 >> 5) + v1) ^ (sum + k[sum & 3]);
178                 sum += 0x9E3779B9;
179                 v1 += ((v0 << 4 ^ v0 >> 5) + v0) ^ (sum + k[sum>>11 & 3]);
180         }
181
182         return (u64) v0 + ((u64) v1 << 32);
183 }
184
185 static int fuse_flush(struct file *file, fl_owner_t id)
186 {
187         struct inode *inode = file->f_path.dentry->d_inode;
188         struct fuse_conn *fc = get_fuse_conn(inode);
189         struct fuse_file *ff = file->private_data;
190         struct fuse_req *req;
191         struct fuse_flush_in inarg;
192         int err;
193
194         if (is_bad_inode(inode))
195                 return -EIO;
196
197         if (fc->no_flush)
198                 return 0;
199
200         req = fuse_get_req_nofail(fc, file);
201         memset(&inarg, 0, sizeof(inarg));
202         inarg.fh = ff->fh;
203         inarg.lock_owner = fuse_lock_owner_id(fc, id);
204         req->in.h.opcode = FUSE_FLUSH;
205         req->in.h.nodeid = get_node_id(inode);
206         req->in.numargs = 1;
207         req->in.args[0].size = sizeof(inarg);
208         req->in.args[0].value = &inarg;
209         req->force = 1;
210         request_send(fc, req);
211         err = req->out.h.error;
212         fuse_put_request(fc, req);
213         if (err == -ENOSYS) {
214                 fc->no_flush = 1;
215                 err = 0;
216         }
217         return err;
218 }
219
220 int fuse_fsync_common(struct file *file, struct dentry *de, int datasync,
221                       int isdir)
222 {
223         struct inode *inode = de->d_inode;
224         struct fuse_conn *fc = get_fuse_conn(inode);
225         struct fuse_file *ff = file->private_data;
226         struct fuse_req *req;
227         struct fuse_fsync_in inarg;
228         int err;
229
230         if (is_bad_inode(inode))
231                 return -EIO;
232
233         if ((!isdir && fc->no_fsync) || (isdir && fc->no_fsyncdir))
234                 return 0;
235
236         req = fuse_get_req(fc);
237         if (IS_ERR(req))
238                 return PTR_ERR(req);
239
240         memset(&inarg, 0, sizeof(inarg));
241         inarg.fh = ff->fh;
242         inarg.fsync_flags = datasync ? 1 : 0;
243         req->in.h.opcode = isdir ? FUSE_FSYNCDIR : FUSE_FSYNC;
244         req->in.h.nodeid = get_node_id(inode);
245         req->in.numargs = 1;
246         req->in.args[0].size = sizeof(inarg);
247         req->in.args[0].value = &inarg;
248         request_send(fc, req);
249         err = req->out.h.error;
250         fuse_put_request(fc, req);
251         if (err == -ENOSYS) {
252                 if (isdir)
253                         fc->no_fsyncdir = 1;
254                 else
255                         fc->no_fsync = 1;
256                 err = 0;
257         }
258         return err;
259 }
260
261 static int fuse_fsync(struct file *file, struct dentry *de, int datasync)
262 {
263         return fuse_fsync_common(file, de, datasync, 0);
264 }
265
266 void fuse_read_fill(struct fuse_req *req, struct file *file,
267                     struct inode *inode, loff_t pos, size_t count, int opcode)
268 {
269         struct fuse_file *ff = file->private_data;
270         struct fuse_read_in *inarg = &req->misc.read_in;
271
272         inarg->fh = ff->fh;
273         inarg->offset = pos;
274         inarg->size = count;
275         req->in.h.opcode = opcode;
276         req->in.h.nodeid = get_node_id(inode);
277         req->in.numargs = 1;
278         req->in.args[0].size = sizeof(struct fuse_read_in);
279         req->in.args[0].value = inarg;
280         req->out.argpages = 1;
281         req->out.argvar = 1;
282         req->out.numargs = 1;
283         req->out.args[0].size = count;
284 }
285
286 static size_t fuse_send_read(struct fuse_req *req, struct file *file,
287                              struct inode *inode, loff_t pos, size_t count)
288 {
289         struct fuse_conn *fc = get_fuse_conn(inode);
290         fuse_read_fill(req, file, inode, pos, count, FUSE_READ);
291         request_send(fc, req);
292         return req->out.args[0].size;
293 }
294
295 static int fuse_readpage(struct file *file, struct page *page)
296 {
297         struct inode *inode = page->mapping->host;
298         struct fuse_conn *fc = get_fuse_conn(inode);
299         struct fuse_req *req;
300         int err;
301
302         err = -EIO;
303         if (is_bad_inode(inode))
304                 goto out;
305
306         req = fuse_get_req(fc);
307         err = PTR_ERR(req);
308         if (IS_ERR(req))
309                 goto out;
310
311         req->out.page_zeroing = 1;
312         req->num_pages = 1;
313         req->pages[0] = page;
314         fuse_send_read(req, file, inode, page_offset(page), PAGE_CACHE_SIZE);
315         err = req->out.h.error;
316         fuse_put_request(fc, req);
317         if (!err)
318                 SetPageUptodate(page);
319         fuse_invalidate_attr(inode); /* atime changed */
320  out:
321         unlock_page(page);
322         return err;
323 }
324
325 static void fuse_readpages_end(struct fuse_conn *fc, struct fuse_req *req)
326 {
327         int i;
328
329         fuse_invalidate_attr(req->pages[0]->mapping->host); /* atime changed */
330
331         for (i = 0; i < req->num_pages; i++) {
332                 struct page *page = req->pages[i];
333                 if (!req->out.h.error)
334                         SetPageUptodate(page);
335                 else
336                         SetPageError(page);
337                 unlock_page(page);
338         }
339         fuse_put_request(fc, req);
340 }
341
342 static void fuse_send_readpages(struct fuse_req *req, struct file *file,
343                                 struct inode *inode)
344 {
345         struct fuse_conn *fc = get_fuse_conn(inode);
346         loff_t pos = page_offset(req->pages[0]);
347         size_t count = req->num_pages << PAGE_CACHE_SHIFT;
348         req->out.page_zeroing = 1;
349         fuse_read_fill(req, file, inode, pos, count, FUSE_READ);
350         if (fc->async_read) {
351                 get_file(file);
352                 req->file = file;
353                 req->end = fuse_readpages_end;
354                 request_send_background(fc, req);
355         } else {
356                 request_send(fc, req);
357                 fuse_readpages_end(fc, req);
358         }
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 = get_fuse_conn(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                 fuse_send_readpages(req, data->file, inode);
379                 data->req = req = fuse_get_req(fc);
380                 if (IS_ERR(req)) {
381                         unlock_page(page);
382                         return PTR_ERR(req);
383                 }
384         }
385         req->pages[req->num_pages] = page;
386         req->num_pages ++;
387         return 0;
388 }
389
390 static int fuse_readpages(struct file *file, struct address_space *mapping,
391                           struct list_head *pages, unsigned nr_pages)
392 {
393         struct inode *inode = mapping->host;
394         struct fuse_conn *fc = get_fuse_conn(inode);
395         struct fuse_readpages_data data;
396         int err;
397
398         err = -EIO;
399         if (is_bad_inode(inode))
400                 goto out;
401
402         data.file = file;
403         data.inode = inode;
404         data.req = fuse_get_req(fc);
405         err = PTR_ERR(data.req);
406         if (IS_ERR(data.req))
407                 goto out;
408
409         err = read_cache_pages(mapping, pages, fuse_readpages_fill, &data);
410         if (!err) {
411                 if (data.req->num_pages)
412                         fuse_send_readpages(data.req, file, inode);
413                 else
414                         fuse_put_request(fc, data.req);
415         }
416 out:
417         return err;
418 }
419
420 static size_t fuse_send_write(struct fuse_req *req, struct file *file,
421                               struct inode *inode, loff_t pos, size_t count)
422 {
423         struct fuse_conn *fc = get_fuse_conn(inode);
424         struct fuse_file *ff = file->private_data;
425         struct fuse_write_in inarg;
426         struct fuse_write_out outarg;
427
428         memset(&inarg, 0, sizeof(struct fuse_write_in));
429         inarg.fh = ff->fh;
430         inarg.offset = pos;
431         inarg.size = count;
432         req->in.h.opcode = FUSE_WRITE;
433         req->in.h.nodeid = get_node_id(inode);
434         req->in.argpages = 1;
435         req->in.numargs = 2;
436         req->in.args[0].size = sizeof(struct fuse_write_in);
437         req->in.args[0].value = &inarg;
438         req->in.args[1].size = count;
439         req->out.numargs = 1;
440         req->out.args[0].size = sizeof(struct fuse_write_out);
441         req->out.args[0].value = &outarg;
442         request_send(fc, req);
443         return outarg.size;
444 }
445
446 static int fuse_prepare_write(struct file *file, struct page *page,
447                               unsigned offset, unsigned to)
448 {
449         /* No op */
450         return 0;
451 }
452
453 static int fuse_commit_write(struct file *file, struct page *page,
454                              unsigned offset, unsigned to)
455 {
456         int err;
457         size_t nres;
458         unsigned count = to - offset;
459         struct inode *inode = page->mapping->host;
460         struct fuse_conn *fc = get_fuse_conn(inode);
461         loff_t pos = page_offset(page) + offset;
462         struct fuse_req *req;
463
464         if (is_bad_inode(inode))
465                 return -EIO;
466
467         req = fuse_get_req(fc);
468         if (IS_ERR(req))
469                 return PTR_ERR(req);
470
471         req->num_pages = 1;
472         req->pages[0] = page;
473         req->page_offset = offset;
474         nres = fuse_send_write(req, file, inode, pos, count);
475         err = req->out.h.error;
476         fuse_put_request(fc, req);
477         if (!err && nres != count)
478                 err = -EIO;
479         if (!err) {
480                 pos += count;
481                 spin_lock(&fc->lock);
482                 if (pos > inode->i_size)
483                         i_size_write(inode, pos);
484                 spin_unlock(&fc->lock);
485
486                 if (offset == 0 && to == PAGE_CACHE_SIZE)
487                         SetPageUptodate(page);
488         }
489         fuse_invalidate_attr(inode);
490         return err;
491 }
492
493 static void fuse_release_user_pages(struct fuse_req *req, int write)
494 {
495         unsigned i;
496
497         for (i = 0; i < req->num_pages; i++) {
498                 struct page *page = req->pages[i];
499                 if (write)
500                         set_page_dirty_lock(page);
501                 put_page(page);
502         }
503 }
504
505 static int fuse_get_user_pages(struct fuse_req *req, const char __user *buf,
506                                unsigned nbytes, int write)
507 {
508         unsigned long user_addr = (unsigned long) buf;
509         unsigned offset = user_addr & ~PAGE_MASK;
510         int npages;
511
512         /* This doesn't work with nfsd */
513         if (!current->mm)
514                 return -EPERM;
515
516         nbytes = min(nbytes, (unsigned) FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT);
517         npages = (nbytes + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
518         npages = min(max(npages, 1), FUSE_MAX_PAGES_PER_REQ);
519         down_read(&current->mm->mmap_sem);
520         npages = get_user_pages(current, current->mm, user_addr, npages, write,
521                                 0, req->pages, NULL);
522         up_read(&current->mm->mmap_sem);
523         if (npages < 0)
524                 return npages;
525
526         req->num_pages = npages;
527         req->page_offset = offset;
528         return 0;
529 }
530
531 static ssize_t fuse_direct_io(struct file *file, const char __user *buf,
532                               size_t count, loff_t *ppos, int write)
533 {
534         struct inode *inode = file->f_path.dentry->d_inode;
535         struct fuse_conn *fc = get_fuse_conn(inode);
536         size_t nmax = write ? fc->max_write : fc->max_read;
537         loff_t pos = *ppos;
538         ssize_t res = 0;
539         struct fuse_req *req;
540
541         if (is_bad_inode(inode))
542                 return -EIO;
543
544         req = fuse_get_req(fc);
545         if (IS_ERR(req))
546                 return PTR_ERR(req);
547
548         while (count) {
549                 size_t nres;
550                 size_t nbytes = min(count, nmax);
551                 int err = fuse_get_user_pages(req, buf, nbytes, !write);
552                 if (err) {
553                         res = err;
554                         break;
555                 }
556                 nbytes = (req->num_pages << PAGE_SHIFT) - req->page_offset;
557                 nbytes = min(count, nbytes);
558                 if (write)
559                         nres = fuse_send_write(req, file, inode, pos, nbytes);
560                 else
561                         nres = fuse_send_read(req, file, inode, pos, nbytes);
562                 fuse_release_user_pages(req, !write);
563                 if (req->out.h.error) {
564                         if (!res)
565                                 res = req->out.h.error;
566                         break;
567                 } else if (nres > nbytes) {
568                         res = -EIO;
569                         break;
570                 }
571                 count -= nres;
572                 res += nres;
573                 pos += nres;
574                 buf += nres;
575                 if (nres != nbytes)
576                         break;
577                 if (count) {
578                         fuse_put_request(fc, req);
579                         req = fuse_get_req(fc);
580                         if (IS_ERR(req))
581                                 break;
582                 }
583         }
584         fuse_put_request(fc, req);
585         if (res > 0) {
586                 if (write) {
587                         spin_lock(&fc->lock);
588                         if (pos > inode->i_size)
589                                 i_size_write(inode, pos);
590                         spin_unlock(&fc->lock);
591                 }
592                 *ppos = pos;
593         }
594         fuse_invalidate_attr(inode);
595
596         return res;
597 }
598
599 static ssize_t fuse_direct_read(struct file *file, char __user *buf,
600                                      size_t count, loff_t *ppos)
601 {
602         return fuse_direct_io(file, buf, count, ppos, 0);
603 }
604
605 static ssize_t fuse_direct_write(struct file *file, const char __user *buf,
606                                  size_t count, loff_t *ppos)
607 {
608         struct inode *inode = file->f_path.dentry->d_inode;
609         ssize_t res;
610         /* Don't allow parallel writes to the same file */
611         mutex_lock(&inode->i_mutex);
612         res = fuse_direct_io(file, buf, count, ppos, 1);
613         mutex_unlock(&inode->i_mutex);
614         return res;
615 }
616
617 static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma)
618 {
619         if ((vma->vm_flags & VM_SHARED)) {
620                 if ((vma->vm_flags & VM_WRITE))
621                         return -ENODEV;
622                 else
623                         vma->vm_flags &= ~VM_MAYWRITE;
624         }
625         return generic_file_mmap(file, vma);
626 }
627
628 static int fuse_set_page_dirty(struct page *page)
629 {
630         printk("fuse_set_page_dirty: should not happen\n");
631         dump_stack();
632         return 0;
633 }
634
635 static int convert_fuse_file_lock(const struct fuse_file_lock *ffl,
636                                   struct file_lock *fl)
637 {
638         switch (ffl->type) {
639         case F_UNLCK:
640                 break;
641
642         case F_RDLCK:
643         case F_WRLCK:
644                 if (ffl->start > OFFSET_MAX || ffl->end > OFFSET_MAX ||
645                     ffl->end < ffl->start)
646                         return -EIO;
647
648                 fl->fl_start = ffl->start;
649                 fl->fl_end = ffl->end;
650                 fl->fl_pid = ffl->pid;
651                 break;
652
653         default:
654                 return -EIO;
655         }
656         fl->fl_type = ffl->type;
657         return 0;
658 }
659
660 static void fuse_lk_fill(struct fuse_req *req, struct file *file,
661                          const struct file_lock *fl, int opcode, pid_t pid)
662 {
663         struct inode *inode = file->f_path.dentry->d_inode;
664         struct fuse_conn *fc = get_fuse_conn(inode);
665         struct fuse_file *ff = file->private_data;
666         struct fuse_lk_in *arg = &req->misc.lk_in;
667
668         arg->fh = ff->fh;
669         arg->owner = fuse_lock_owner_id(fc, fl->fl_owner);
670         arg->lk.start = fl->fl_start;
671         arg->lk.end = fl->fl_end;
672         arg->lk.type = fl->fl_type;
673         arg->lk.pid = pid;
674         req->in.h.opcode = opcode;
675         req->in.h.nodeid = get_node_id(inode);
676         req->in.numargs = 1;
677         req->in.args[0].size = sizeof(*arg);
678         req->in.args[0].value = arg;
679 }
680
681 static int fuse_getlk(struct file *file, struct file_lock *fl)
682 {
683         struct inode *inode = file->f_path.dentry->d_inode;
684         struct fuse_conn *fc = get_fuse_conn(inode);
685         struct fuse_req *req;
686         struct fuse_lk_out outarg;
687         int err;
688
689         req = fuse_get_req(fc);
690         if (IS_ERR(req))
691                 return PTR_ERR(req);
692
693         fuse_lk_fill(req, file, fl, FUSE_GETLK, 0);
694         req->out.numargs = 1;
695         req->out.args[0].size = sizeof(outarg);
696         req->out.args[0].value = &outarg;
697         request_send(fc, req);
698         err = req->out.h.error;
699         fuse_put_request(fc, req);
700         if (!err)
701                 err = convert_fuse_file_lock(&outarg.lk, fl);
702
703         return err;
704 }
705
706 static int fuse_setlk(struct file *file, struct file_lock *fl)
707 {
708         struct inode *inode = file->f_path.dentry->d_inode;
709         struct fuse_conn *fc = get_fuse_conn(inode);
710         struct fuse_req *req;
711         int opcode = (fl->fl_flags & FL_SLEEP) ? FUSE_SETLKW : FUSE_SETLK;
712         pid_t pid = fl->fl_type != F_UNLCK ? current->tgid : 0;
713         int err;
714
715         /* Unlock on close is handled by the flush method */
716         if (fl->fl_flags & FL_CLOSE)
717                 return 0;
718
719         req = fuse_get_req(fc);
720         if (IS_ERR(req))
721                 return PTR_ERR(req);
722
723         fuse_lk_fill(req, file, fl, opcode, pid);
724         request_send(fc, req);
725         err = req->out.h.error;
726         /* locking is restartable */
727         if (err == -EINTR)
728                 err = -ERESTARTSYS;
729         fuse_put_request(fc, req);
730         return err;
731 }
732
733 static int fuse_file_lock(struct file *file, int cmd, struct file_lock *fl)
734 {
735         struct inode *inode = file->f_path.dentry->d_inode;
736         struct fuse_conn *fc = get_fuse_conn(inode);
737         int err;
738
739         if (cmd == F_GETLK) {
740                 if (fc->no_lock) {
741                         if (!posix_test_lock(file, fl, fl))
742                                 fl->fl_type = F_UNLCK;
743                         err = 0;
744                 } else
745                         err = fuse_getlk(file, fl);
746         } else {
747                 if (fc->no_lock)
748                         err = posix_lock_file_wait(file, fl);
749                 else
750                         err = fuse_setlk(file, fl);
751         }
752         return err;
753 }
754
755 static sector_t fuse_bmap(struct address_space *mapping, sector_t block)
756 {
757         struct inode *inode = mapping->host;
758         struct fuse_conn *fc = get_fuse_conn(inode);
759         struct fuse_req *req;
760         struct fuse_bmap_in inarg;
761         struct fuse_bmap_out outarg;
762         int err;
763
764         if (!inode->i_sb->s_bdev || fc->no_bmap)
765                 return 0;
766
767         req = fuse_get_req(fc);
768         if (IS_ERR(req))
769                 return 0;
770
771         memset(&inarg, 0, sizeof(inarg));
772         inarg.block = block;
773         inarg.blocksize = inode->i_sb->s_blocksize;
774         req->in.h.opcode = FUSE_BMAP;
775         req->in.h.nodeid = get_node_id(inode);
776         req->in.numargs = 1;
777         req->in.args[0].size = sizeof(inarg);
778         req->in.args[0].value = &inarg;
779         req->out.numargs = 1;
780         req->out.args[0].size = sizeof(outarg);
781         req->out.args[0].value = &outarg;
782         request_send(fc, req);
783         err = req->out.h.error;
784         fuse_put_request(fc, req);
785         if (err == -ENOSYS)
786                 fc->no_bmap = 1;
787
788         return err ? 0 : outarg.block;
789 }
790
791 static const struct file_operations fuse_file_operations = {
792         .llseek         = generic_file_llseek,
793         .read           = do_sync_read,
794         .aio_read       = generic_file_aio_read,
795         .write          = do_sync_write,
796         .aio_write      = generic_file_aio_write,
797         .mmap           = fuse_file_mmap,
798         .open           = fuse_open,
799         .flush          = fuse_flush,
800         .release        = fuse_release,
801         .fsync          = fuse_fsync,
802         .lock           = fuse_file_lock,
803         .sendfile       = generic_file_sendfile,
804 };
805
806 static const struct file_operations fuse_direct_io_file_operations = {
807         .llseek         = generic_file_llseek,
808         .read           = fuse_direct_read,
809         .write          = fuse_direct_write,
810         .open           = fuse_open,
811         .flush          = fuse_flush,
812         .release        = fuse_release,
813         .fsync          = fuse_fsync,
814         .lock           = fuse_file_lock,
815         /* no mmap and sendfile */
816 };
817
818 static const struct address_space_operations fuse_file_aops  = {
819         .readpage       = fuse_readpage,
820         .prepare_write  = fuse_prepare_write,
821         .commit_write   = fuse_commit_write,
822         .readpages      = fuse_readpages,
823         .set_page_dirty = fuse_set_page_dirty,
824         .bmap           = fuse_bmap,
825 };
826
827 void fuse_init_file_inode(struct inode *inode)
828 {
829         inode->i_fop = &fuse_file_operations;
830         inode->i_data.a_ops = &fuse_file_aops;
831 }