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9#include <linux/module.h>
10#include <linux/errno.h>
11#include <linux/fs.h>
12#include <linux/sched.h>
13#include <linux/file.h>
14#include <linux/stat.h>
15#include <linux/string.h>
16#include <linux/inet.h>
17#include <linux/list.h>
18#include <linux/pagemap.h>
19#include <linux/utsname.h>
20#include <linux/uaccess.h>
21#include <linux/idr.h>
22#include <linux/uio.h>
23#include <linux/slab.h>
24#include <net/9p/9p.h>
25#include <net/9p/client.h>
26
27#include "v9fs.h"
28#include "v9fs_vfs.h"
29#include "fid.h"
30#include "cache.h"
31
32static const struct vm_operations_struct v9fs_file_vm_ops;
33static const struct vm_operations_struct v9fs_mmap_file_vm_ops;
34
35
36
37
38
39
40
41
42int v9fs_file_open(struct inode *inode, struct file *file)
43{
44 int err;
45 struct v9fs_inode *v9inode;
46 struct v9fs_session_info *v9ses;
47 struct p9_fid *fid, *writeback_fid;
48 int omode;
49
50 p9_debug(P9_DEBUG_VFS, "inode: %p file: %p\n", inode, file);
51 v9inode = V9FS_I(inode);
52 v9ses = v9fs_inode2v9ses(inode);
53 if (v9fs_proto_dotl(v9ses))
54 omode = v9fs_open_to_dotl_flags(file->f_flags);
55 else
56 omode = v9fs_uflags2omode(file->f_flags,
57 v9fs_proto_dotu(v9ses));
58 fid = file->private_data;
59 if (!fid) {
60 fid = v9fs_fid_clone(file_dentry(file));
61 if (IS_ERR(fid))
62 return PTR_ERR(fid);
63
64 err = p9_client_open(fid, omode);
65 if (err < 0) {
66 p9_client_clunk(fid);
67 return err;
68 }
69 if ((file->f_flags & O_APPEND) &&
70 (!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)))
71 generic_file_llseek(file, 0, SEEK_END);
72 }
73
74 file->private_data = fid;
75 mutex_lock(&v9inode->v_mutex);
76 if ((v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) &&
77 !v9inode->writeback_fid &&
78 ((file->f_flags & O_ACCMODE) != O_RDONLY)) {
79
80
81
82
83
84
85
86 writeback_fid = v9fs_writeback_fid(file_dentry(file));
87 if (IS_ERR(writeback_fid)) {
88 err = PTR_ERR(writeback_fid);
89 mutex_unlock(&v9inode->v_mutex);
90 goto out_error;
91 }
92 v9inode->writeback_fid = (void *) writeback_fid;
93 }
94 mutex_unlock(&v9inode->v_mutex);
95 if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
96 fscache_use_cookie(v9fs_inode_cookie(v9inode),
97 file->f_mode & FMODE_WRITE);
98 v9fs_open_fid_add(inode, fid);
99 return 0;
100out_error:
101 p9_client_clunk(file->private_data);
102 file->private_data = NULL;
103 return err;
104}
105
106
107
108
109
110
111
112
113
114
115
116static int v9fs_file_lock(struct file *filp, int cmd, struct file_lock *fl)
117{
118 struct inode *inode = file_inode(filp);
119
120 p9_debug(P9_DEBUG_VFS, "filp: %p lock: %p\n", filp, fl);
121
122 if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
123 filemap_write_and_wait(inode->i_mapping);
124 invalidate_mapping_pages(&inode->i_data, 0, -1);
125 }
126
127 return 0;
128}
129
130static int v9fs_file_do_lock(struct file *filp, int cmd, struct file_lock *fl)
131{
132 struct p9_flock flock;
133 struct p9_fid *fid;
134 uint8_t status = P9_LOCK_ERROR;
135 int res = 0;
136 unsigned char fl_type;
137 struct v9fs_session_info *v9ses;
138
139 fid = filp->private_data;
140 BUG_ON(fid == NULL);
141
142 BUG_ON((fl->fl_flags & FL_POSIX) != FL_POSIX);
143
144 res = locks_lock_file_wait(filp, fl);
145 if (res < 0)
146 goto out;
147
148
149 memset(&flock, 0, sizeof(flock));
150
151 switch (fl->fl_type) {
152 case F_RDLCK:
153 flock.type = P9_LOCK_TYPE_RDLCK;
154 break;
155 case F_WRLCK:
156 flock.type = P9_LOCK_TYPE_WRLCK;
157 break;
158 case F_UNLCK:
159 flock.type = P9_LOCK_TYPE_UNLCK;
160 break;
161 }
162 flock.start = fl->fl_start;
163 if (fl->fl_end == OFFSET_MAX)
164 flock.length = 0;
165 else
166 flock.length = fl->fl_end - fl->fl_start + 1;
167 flock.proc_id = fl->fl_pid;
168 flock.client_id = fid->clnt->name;
169 if (IS_SETLKW(cmd))
170 flock.flags = P9_LOCK_FLAGS_BLOCK;
171
172 v9ses = v9fs_inode2v9ses(file_inode(filp));
173
174
175
176
177
178 for (;;) {
179 res = p9_client_lock_dotl(fid, &flock, &status);
180 if (res < 0)
181 goto out_unlock;
182
183 if (status != P9_LOCK_BLOCKED)
184 break;
185 if (status == P9_LOCK_BLOCKED && !IS_SETLKW(cmd))
186 break;
187 if (schedule_timeout_interruptible(v9ses->session_lock_timeout)
188 != 0)
189 break;
190
191
192
193
194 if (flock.client_id != fid->clnt->name) {
195 kfree(flock.client_id);
196 flock.client_id = fid->clnt->name;
197 }
198 }
199
200
201 switch (status) {
202 case P9_LOCK_SUCCESS:
203 res = 0;
204 break;
205 case P9_LOCK_BLOCKED:
206 res = -EAGAIN;
207 break;
208 default:
209 WARN_ONCE(1, "unknown lock status code: %d\n", status);
210 fallthrough;
211 case P9_LOCK_ERROR:
212 case P9_LOCK_GRACE:
213 res = -ENOLCK;
214 break;
215 }
216
217out_unlock:
218
219
220
221
222 if (res < 0 && fl->fl_type != F_UNLCK) {
223 fl_type = fl->fl_type;
224 fl->fl_type = F_UNLCK;
225
226 locks_lock_file_wait(filp, fl);
227 fl->fl_type = fl_type;
228 }
229 if (flock.client_id != fid->clnt->name)
230 kfree(flock.client_id);
231out:
232 return res;
233}
234
235static int v9fs_file_getlock(struct file *filp, struct file_lock *fl)
236{
237 struct p9_getlock glock;
238 struct p9_fid *fid;
239 int res = 0;
240
241 fid = filp->private_data;
242 BUG_ON(fid == NULL);
243
244 posix_test_lock(filp, fl);
245
246
247
248
249 if (fl->fl_type != F_UNLCK)
250 return res;
251
252
253 memset(&glock, 0, sizeof(glock));
254 glock.type = P9_LOCK_TYPE_UNLCK;
255 glock.start = fl->fl_start;
256 if (fl->fl_end == OFFSET_MAX)
257 glock.length = 0;
258 else
259 glock.length = fl->fl_end - fl->fl_start + 1;
260 glock.proc_id = fl->fl_pid;
261 glock.client_id = fid->clnt->name;
262
263 res = p9_client_getlock_dotl(fid, &glock);
264 if (res < 0)
265 goto out;
266
267 switch (glock.type) {
268 case P9_LOCK_TYPE_RDLCK:
269 fl->fl_type = F_RDLCK;
270 break;
271 case P9_LOCK_TYPE_WRLCK:
272 fl->fl_type = F_WRLCK;
273 break;
274 case P9_LOCK_TYPE_UNLCK:
275 fl->fl_type = F_UNLCK;
276 break;
277 }
278 if (glock.type != P9_LOCK_TYPE_UNLCK) {
279 fl->fl_start = glock.start;
280 if (glock.length == 0)
281 fl->fl_end = OFFSET_MAX;
282 else
283 fl->fl_end = glock.start + glock.length - 1;
284 fl->fl_pid = -glock.proc_id;
285 }
286out:
287 if (glock.client_id != fid->clnt->name)
288 kfree(glock.client_id);
289 return res;
290}
291
292
293
294
295
296
297
298
299
300static int v9fs_file_lock_dotl(struct file *filp, int cmd, struct file_lock *fl)
301{
302 struct inode *inode = file_inode(filp);
303 int ret = -ENOLCK;
304
305 p9_debug(P9_DEBUG_VFS, "filp: %p cmd:%d lock: %p name: %pD\n",
306 filp, cmd, fl, filp);
307
308 if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
309 filemap_write_and_wait(inode->i_mapping);
310 invalidate_mapping_pages(&inode->i_data, 0, -1);
311 }
312
313 if (IS_SETLK(cmd) || IS_SETLKW(cmd))
314 ret = v9fs_file_do_lock(filp, cmd, fl);
315 else if (IS_GETLK(cmd))
316 ret = v9fs_file_getlock(filp, fl);
317 else
318 ret = -EINVAL;
319 return ret;
320}
321
322
323
324
325
326
327
328
329
330static int v9fs_file_flock_dotl(struct file *filp, int cmd,
331 struct file_lock *fl)
332{
333 struct inode *inode = file_inode(filp);
334 int ret = -ENOLCK;
335
336 p9_debug(P9_DEBUG_VFS, "filp: %p cmd:%d lock: %p name: %pD\n",
337 filp, cmd, fl, filp);
338
339 if (!(fl->fl_flags & FL_FLOCK))
340 goto out_err;
341
342 if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
343 filemap_write_and_wait(inode->i_mapping);
344 invalidate_mapping_pages(&inode->i_data, 0, -1);
345 }
346
347 fl->fl_flags |= FL_POSIX;
348 fl->fl_flags ^= FL_FLOCK;
349
350 if (IS_SETLK(cmd) | IS_SETLKW(cmd))
351 ret = v9fs_file_do_lock(filp, cmd, fl);
352 else
353 ret = -EINVAL;
354out_err:
355 return ret;
356}
357
358
359
360
361
362
363
364static ssize_t
365v9fs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
366{
367 struct p9_fid *fid = iocb->ki_filp->private_data;
368 int ret, err = 0;
369
370 p9_debug(P9_DEBUG_VFS, "count %zu offset %lld\n",
371 iov_iter_count(to), iocb->ki_pos);
372
373 if (iocb->ki_filp->f_flags & O_NONBLOCK)
374 ret = p9_client_read_once(fid, iocb->ki_pos, to, &err);
375 else
376 ret = p9_client_read(fid, iocb->ki_pos, to, &err);
377 if (!ret)
378 return err;
379
380 iocb->ki_pos += ret;
381 return ret;
382}
383
384
385
386
387
388
389
390static ssize_t
391v9fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
392{
393 struct file *file = iocb->ki_filp;
394 ssize_t retval;
395 loff_t origin;
396 int err = 0;
397
398 retval = generic_write_checks(iocb, from);
399 if (retval <= 0)
400 return retval;
401
402 origin = iocb->ki_pos;
403 retval = p9_client_write(file->private_data, iocb->ki_pos, from, &err);
404 if (retval > 0) {
405 struct inode *inode = file_inode(file);
406 loff_t i_size;
407 unsigned long pg_start, pg_end;
408
409 pg_start = origin >> PAGE_SHIFT;
410 pg_end = (origin + retval - 1) >> PAGE_SHIFT;
411 if (inode->i_mapping && inode->i_mapping->nrpages)
412 invalidate_inode_pages2_range(inode->i_mapping,
413 pg_start, pg_end);
414 iocb->ki_pos += retval;
415 i_size = i_size_read(inode);
416 if (iocb->ki_pos > i_size) {
417 inode_add_bytes(inode, iocb->ki_pos - i_size);
418
419
420
421
422 v9fs_i_size_write(inode, iocb->ki_pos);
423 }
424 return retval;
425 }
426 return err;
427}
428
429static int v9fs_file_fsync(struct file *filp, loff_t start, loff_t end,
430 int datasync)
431{
432 struct p9_fid *fid;
433 struct inode *inode = filp->f_mapping->host;
434 struct p9_wstat wstat;
435 int retval;
436
437 retval = file_write_and_wait_range(filp, start, end);
438 if (retval)
439 return retval;
440
441 inode_lock(inode);
442 p9_debug(P9_DEBUG_VFS, "filp %p datasync %x\n", filp, datasync);
443
444 fid = filp->private_data;
445 v9fs_blank_wstat(&wstat);
446
447 retval = p9_client_wstat(fid, &wstat);
448 inode_unlock(inode);
449
450 return retval;
451}
452
453int v9fs_file_fsync_dotl(struct file *filp, loff_t start, loff_t end,
454 int datasync)
455{
456 struct p9_fid *fid;
457 struct inode *inode = filp->f_mapping->host;
458 int retval;
459
460 retval = file_write_and_wait_range(filp, start, end);
461 if (retval)
462 return retval;
463
464 inode_lock(inode);
465 p9_debug(P9_DEBUG_VFS, "filp %p datasync %x\n", filp, datasync);
466
467 fid = filp->private_data;
468
469 retval = p9_client_fsync(fid, datasync);
470 inode_unlock(inode);
471
472 return retval;
473}
474
475static int
476v9fs_file_mmap(struct file *filp, struct vm_area_struct *vma)
477{
478 int retval;
479
480
481 retval = generic_file_mmap(filp, vma);
482 if (!retval)
483 vma->vm_ops = &v9fs_file_vm_ops;
484
485 return retval;
486}
487
488static int
489v9fs_mmap_file_mmap(struct file *filp, struct vm_area_struct *vma)
490{
491 int retval;
492 struct inode *inode;
493 struct v9fs_inode *v9inode;
494 struct p9_fid *fid;
495
496 inode = file_inode(filp);
497 v9inode = V9FS_I(inode);
498 mutex_lock(&v9inode->v_mutex);
499 if (!v9inode->writeback_fid &&
500 (vma->vm_flags & VM_SHARED) &&
501 (vma->vm_flags & VM_WRITE)) {
502
503
504
505
506
507
508
509 fid = v9fs_writeback_fid(file_dentry(filp));
510 if (IS_ERR(fid)) {
511 retval = PTR_ERR(fid);
512 mutex_unlock(&v9inode->v_mutex);
513 return retval;
514 }
515 v9inode->writeback_fid = (void *) fid;
516 }
517 mutex_unlock(&v9inode->v_mutex);
518
519 retval = generic_file_mmap(filp, vma);
520 if (!retval)
521 vma->vm_ops = &v9fs_mmap_file_vm_ops;
522
523 return retval;
524}
525
526static vm_fault_t
527v9fs_vm_page_mkwrite(struct vm_fault *vmf)
528{
529 struct v9fs_inode *v9inode;
530 struct folio *folio = page_folio(vmf->page);
531 struct file *filp = vmf->vma->vm_file;
532 struct inode *inode = file_inode(filp);
533
534
535 p9_debug(P9_DEBUG_VFS, "folio %p fid %lx\n",
536 folio, (unsigned long)filp->private_data);
537
538 v9inode = V9FS_I(inode);
539
540
541
542
543#ifdef CONFIG_9P_FSCACHE
544 if (folio_test_fscache(folio) &&
545 folio_wait_fscache_killable(folio) < 0)
546 return VM_FAULT_NOPAGE;
547#endif
548
549
550 file_update_time(filp);
551
552 BUG_ON(!v9inode->writeback_fid);
553 if (folio_lock_killable(folio) < 0)
554 return VM_FAULT_RETRY;
555 if (folio_mapping(folio) != inode->i_mapping)
556 goto out_unlock;
557 folio_wait_stable(folio);
558
559 return VM_FAULT_LOCKED;
560out_unlock:
561 folio_unlock(folio);
562 return VM_FAULT_NOPAGE;
563}
564
565
566
567
568
569
570
571static ssize_t
572v9fs_mmap_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
573{
574
575 return v9fs_file_read_iter(iocb, to);
576}
577
578
579
580
581
582
583
584static ssize_t
585v9fs_mmap_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
586{
587
588
589
590
591 return v9fs_file_write_iter(iocb, from);
592}
593
594static void v9fs_mmap_vm_close(struct vm_area_struct *vma)
595{
596 struct inode *inode;
597
598 struct writeback_control wbc = {
599 .nr_to_write = LONG_MAX,
600 .sync_mode = WB_SYNC_ALL,
601 .range_start = (loff_t)vma->vm_pgoff * PAGE_SIZE,
602
603 .range_end = (loff_t)vma->vm_pgoff * PAGE_SIZE +
604 (vma->vm_end - vma->vm_start - 1),
605 };
606
607 if (!(vma->vm_flags & VM_SHARED))
608 return;
609
610 p9_debug(P9_DEBUG_VFS, "9p VMA close, %p, flushing", vma);
611
612 inode = file_inode(vma->vm_file);
613 filemap_fdatawrite_wbc(inode->i_mapping, &wbc);
614}
615
616
617static const struct vm_operations_struct v9fs_file_vm_ops = {
618 .fault = filemap_fault,
619 .map_pages = filemap_map_pages,
620 .page_mkwrite = v9fs_vm_page_mkwrite,
621};
622
623static const struct vm_operations_struct v9fs_mmap_file_vm_ops = {
624 .close = v9fs_mmap_vm_close,
625 .fault = filemap_fault,
626 .map_pages = filemap_map_pages,
627 .page_mkwrite = v9fs_vm_page_mkwrite,
628};
629
630
631const struct file_operations v9fs_cached_file_operations = {
632 .llseek = generic_file_llseek,
633 .read_iter = generic_file_read_iter,
634 .write_iter = generic_file_write_iter,
635 .open = v9fs_file_open,
636 .release = v9fs_dir_release,
637 .lock = v9fs_file_lock,
638 .mmap = v9fs_file_mmap,
639 .splice_read = generic_file_splice_read,
640 .splice_write = iter_file_splice_write,
641 .fsync = v9fs_file_fsync,
642};
643
644const struct file_operations v9fs_cached_file_operations_dotl = {
645 .llseek = generic_file_llseek,
646 .read_iter = generic_file_read_iter,
647 .write_iter = generic_file_write_iter,
648 .open = v9fs_file_open,
649 .release = v9fs_dir_release,
650 .lock = v9fs_file_lock_dotl,
651 .flock = v9fs_file_flock_dotl,
652 .mmap = v9fs_file_mmap,
653 .splice_read = generic_file_splice_read,
654 .splice_write = iter_file_splice_write,
655 .fsync = v9fs_file_fsync_dotl,
656};
657
658const struct file_operations v9fs_file_operations = {
659 .llseek = generic_file_llseek,
660 .read_iter = v9fs_file_read_iter,
661 .write_iter = v9fs_file_write_iter,
662 .open = v9fs_file_open,
663 .release = v9fs_dir_release,
664 .lock = v9fs_file_lock,
665 .mmap = generic_file_readonly_mmap,
666 .splice_read = generic_file_splice_read,
667 .splice_write = iter_file_splice_write,
668 .fsync = v9fs_file_fsync,
669};
670
671const struct file_operations v9fs_file_operations_dotl = {
672 .llseek = generic_file_llseek,
673 .read_iter = v9fs_file_read_iter,
674 .write_iter = v9fs_file_write_iter,
675 .open = v9fs_file_open,
676 .release = v9fs_dir_release,
677 .lock = v9fs_file_lock_dotl,
678 .flock = v9fs_file_flock_dotl,
679 .mmap = generic_file_readonly_mmap,
680 .splice_read = generic_file_splice_read,
681 .splice_write = iter_file_splice_write,
682 .fsync = v9fs_file_fsync_dotl,
683};
684
685const struct file_operations v9fs_mmap_file_operations = {
686 .llseek = generic_file_llseek,
687 .read_iter = v9fs_mmap_file_read_iter,
688 .write_iter = v9fs_mmap_file_write_iter,
689 .open = v9fs_file_open,
690 .release = v9fs_dir_release,
691 .lock = v9fs_file_lock,
692 .mmap = v9fs_mmap_file_mmap,
693 .splice_read = generic_file_splice_read,
694 .splice_write = iter_file_splice_write,
695 .fsync = v9fs_file_fsync,
696};
697
698const struct file_operations v9fs_mmap_file_operations_dotl = {
699 .llseek = generic_file_llseek,
700 .read_iter = v9fs_mmap_file_read_iter,
701 .write_iter = v9fs_mmap_file_write_iter,
702 .open = v9fs_file_open,
703 .release = v9fs_dir_release,
704 .lock = v9fs_file_lock_dotl,
705 .flock = v9fs_file_flock_dotl,
706 .mmap = v9fs_mmap_file_mmap,
707 .splice_read = generic_file_splice_read,
708 .splice_write = iter_file_splice_write,
709 .fsync = v9fs_file_fsync_dotl,
710};
711
