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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * This file contians vfs file ops for 9P2000.
4 *
5 * Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
6 * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
7 */
8
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/uio.h>
22#include <linux/slab.h>
23#include <net/9p/9p.h>
24#include <net/9p/client.h>
25
26#include "v9fs.h"
27#include "v9fs_vfs.h"
28#include "fid.h"
29#include "cache.h"
30
31static const struct vm_operations_struct v9fs_file_vm_ops;
32static const struct vm_operations_struct v9fs_mmap_file_vm_ops;
33
34/**
35 * v9fs_file_open - open a file (or directory)
36 * @inode: inode to be opened
37 * @file: file being opened
38 *
39 */
40
41int v9fs_file_open(struct inode *inode, struct file *file)
42{
43 int err;
44 struct v9fs_inode *v9inode;
45 struct v9fs_session_info *v9ses;
46 struct p9_fid *fid, *writeback_fid;
47 int omode;
48
49 p9_debug(P9_DEBUG_VFS, "inode: %p file: %p\n", inode, file);
50 v9inode = V9FS_I(inode);
51 v9ses = v9fs_inode2v9ses(inode);
52 if (v9fs_proto_dotl(v9ses))
53 omode = v9fs_open_to_dotl_flags(file->f_flags);
54 else
55 omode = v9fs_uflags2omode(file->f_flags,
56 v9fs_proto_dotu(v9ses));
57 fid = file->private_data;
58 if (!fid) {
59 fid = v9fs_fid_clone(file_dentry(file));
60 if (IS_ERR(fid))
61 return PTR_ERR(fid);
62
63 err = p9_client_open(fid, omode);
64 if (err < 0) {
65 p9_fid_put(fid);
66 return err;
67 }
68 if ((file->f_flags & O_APPEND) &&
69 (!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)))
70 generic_file_llseek(file, 0, SEEK_END);
71
72 file->private_data = fid;
73 }
74
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 * clone a fid and add it to writeback_fid
81 * we do it during open time instead of
82 * page dirty time via write_begin/page_mkwrite
83 * because we want write after unlink usecase
84 * to work.
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_fid_put(file->private_data);
102 file->private_data = NULL;
103 return err;
104}
105
106/**
107 * v9fs_file_lock - lock a file (or directory)
108 * @filp: file to be locked
109 * @cmd: lock command
110 * @fl: file lock structure
111 *
112 * Bugs: this looks like a local only lock, we should extend into 9P
113 * by using open exclusive
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 /* convert posix lock to p9 tlock args */
149 memset(&flock, 0, sizeof(flock));
150 /* map the lock type */
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 * if its a blocked request and we get P9_LOCK_BLOCKED as the status
176 * for lock request, keep on trying
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 * p9_client_lock_dotl overwrites flock.client_id with the
192 * server message, free and reuse the client name
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 /* map 9p status to VFS status */
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 * incase server returned error for lock request, revert
220 * it locally
221 */
222 if (res < 0 && fl->fl_type != F_UNLCK) {
223 fl_type = fl->fl_type;
224 fl->fl_type = F_UNLCK;
225 /* Even if this fails we want to return the remote error */
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 * if we have a conflicting lock locally, no need to validate
247 * with server
248 */
249 if (fl->fl_type != F_UNLCK)
250 return res;
251
252 /* convert posix lock to p9 tgetlock args */
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 /* map 9p lock type to os lock type */
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 * v9fs_file_lock_dotl - lock a file (or directory)
294 * @filp: file to be locked
295 * @cmd: lock command
296 * @fl: file lock structure
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 * v9fs_file_flock_dotl - lock a file
324 * @filp: file to be locked
325 * @cmd: lock command
326 * @fl: file lock structure
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 /* Convert flock to posix lock */
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 * v9fs_file_read_iter - read from a file
360 * @iocb: The operation parameters
361 * @to: The buffer to read into
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 * v9fs_file_write_iter - write to a file
386 * @iocb: The operation parameters
387 * @from: The data to write
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 * Need to serialize against i_size_write() in
420 * v9fs_stat2inode()
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 * clone a fid and add it to writeback_fid
504 * we do it during mmap instead of
505 * page dirty time via write_begin/page_mkwrite
506 * because we want write after unlink usecase
507 * to work.
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 /* Wait for the page to be written to the cache before we allow it to
541 * be modified. We then assume the entire page will need writing back.
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 /* Update file times before taking page lock */
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 * v9fs_mmap_file_read_iter - read from a file
567 * @iocb: The operation parameters
568 * @to: The buffer to read into
569 *
570 */
571static ssize_t
572v9fs_mmap_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
573{
574 /* TODO: Check if there are dirty pages */
575 return v9fs_file_read_iter(iocb, to);
576}
577
578/**
579 * v9fs_mmap_file_write_iter - write to a file
580 * @iocb: The operation parameters
581 * @from: The data to write
582 *
583 */
584static ssize_t
585v9fs_mmap_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
586{
587 /*
588 * TODO: invalidate mmaps on filp's inode between
589 * offset and offset+count
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 /* absolute end, byte at end included */
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};
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * This file contians vfs file ops for 9P2000.
4 *
5 * Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
6 * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
7 */
8
9#include <linux/module.h>
10#include <linux/errno.h>
11#include <linux/fs.h>
12#include <linux/filelock.h>
13#include <linux/sched.h>
14#include <linux/file.h>
15#include <linux/stat.h>
16#include <linux/string.h>
17#include <linux/list.h>
18#include <linux/pagemap.h>
19#include <linux/utsname.h>
20#include <linux/uaccess.h>
21#include <linux/uio.h>
22#include <linux/slab.h>
23#include <net/9p/9p.h>
24#include <net/9p/client.h>
25
26#include "v9fs.h"
27#include "v9fs_vfs.h"
28#include "fid.h"
29#include "cache.h"
30
31static const struct vm_operations_struct v9fs_mmap_file_vm_ops;
32
33/**
34 * v9fs_file_open - open a file (or directory)
35 * @inode: inode to be opened
36 * @file: file being opened
37 *
38 */
39
40int v9fs_file_open(struct inode *inode, struct file *file)
41{
42 int err;
43 struct v9fs_session_info *v9ses;
44 struct p9_fid *fid;
45 int omode;
46
47 p9_debug(P9_DEBUG_VFS, "inode: %p file: %p\n", inode, file);
48 v9ses = v9fs_inode2v9ses(inode);
49 if (v9fs_proto_dotl(v9ses))
50 omode = v9fs_open_to_dotl_flags(file->f_flags);
51 else
52 omode = v9fs_uflags2omode(file->f_flags,
53 v9fs_proto_dotu(v9ses));
54 fid = file->private_data;
55 if (!fid) {
56 fid = v9fs_fid_clone(file_dentry(file));
57 if (IS_ERR(fid))
58 return PTR_ERR(fid);
59
60 if ((v9ses->cache & CACHE_WRITEBACK) && (omode & P9_OWRITE)) {
61 int writeback_omode = (omode & ~P9_OWRITE) | P9_ORDWR;
62
63 p9_debug(P9_DEBUG_CACHE, "write-only file with writeback enabled, try opening O_RDWR\n");
64 err = p9_client_open(fid, writeback_omode);
65 if (err < 0) {
66 p9_debug(P9_DEBUG_CACHE, "could not open O_RDWR, disabling caches\n");
67 err = p9_client_open(fid, omode);
68 fid->mode |= P9L_DIRECT;
69 }
70 } else {
71 err = p9_client_open(fid, omode);
72 }
73 if (err < 0) {
74 p9_fid_put(fid);
75 return err;
76 }
77 if ((file->f_flags & O_APPEND) &&
78 (!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)))
79 generic_file_llseek(file, 0, SEEK_END);
80
81 file->private_data = fid;
82 }
83
84#ifdef CONFIG_9P_FSCACHE
85 if (v9ses->cache & CACHE_FSCACHE)
86 fscache_use_cookie(v9fs_inode_cookie(V9FS_I(inode)),
87 file->f_mode & FMODE_WRITE);
88#endif
89 v9fs_fid_add_modes(fid, v9ses->flags, v9ses->cache, file->f_flags);
90 v9fs_open_fid_add(inode, &fid);
91 return 0;
92}
93
94/**
95 * v9fs_file_lock - lock a file (or directory)
96 * @filp: file to be locked
97 * @cmd: lock command
98 * @fl: file lock structure
99 *
100 * Bugs: this looks like a local only lock, we should extend into 9P
101 * by using open exclusive
102 */
103
104static int v9fs_file_lock(struct file *filp, int cmd, struct file_lock *fl)
105{
106 struct inode *inode = file_inode(filp);
107
108 p9_debug(P9_DEBUG_VFS, "filp: %p lock: %p\n", filp, fl);
109
110 if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
111 filemap_write_and_wait(inode->i_mapping);
112 invalidate_mapping_pages(&inode->i_data, 0, -1);
113 }
114
115 return 0;
116}
117
118static int v9fs_file_do_lock(struct file *filp, int cmd, struct file_lock *fl)
119{
120 struct p9_flock flock;
121 struct p9_fid *fid;
122 uint8_t status = P9_LOCK_ERROR;
123 int res = 0;
124 unsigned char fl_type;
125 struct v9fs_session_info *v9ses;
126
127 fid = filp->private_data;
128 BUG_ON(fid == NULL);
129
130 BUG_ON((fl->fl_flags & FL_POSIX) != FL_POSIX);
131
132 res = locks_lock_file_wait(filp, fl);
133 if (res < 0)
134 goto out;
135
136 /* convert posix lock to p9 tlock args */
137 memset(&flock, 0, sizeof(flock));
138 /* map the lock type */
139 switch (fl->fl_type) {
140 case F_RDLCK:
141 flock.type = P9_LOCK_TYPE_RDLCK;
142 break;
143 case F_WRLCK:
144 flock.type = P9_LOCK_TYPE_WRLCK;
145 break;
146 case F_UNLCK:
147 flock.type = P9_LOCK_TYPE_UNLCK;
148 break;
149 }
150 flock.start = fl->fl_start;
151 if (fl->fl_end == OFFSET_MAX)
152 flock.length = 0;
153 else
154 flock.length = fl->fl_end - fl->fl_start + 1;
155 flock.proc_id = fl->fl_pid;
156 flock.client_id = fid->clnt->name;
157 if (IS_SETLKW(cmd))
158 flock.flags = P9_LOCK_FLAGS_BLOCK;
159
160 v9ses = v9fs_inode2v9ses(file_inode(filp));
161
162 /*
163 * if its a blocked request and we get P9_LOCK_BLOCKED as the status
164 * for lock request, keep on trying
165 */
166 for (;;) {
167 res = p9_client_lock_dotl(fid, &flock, &status);
168 if (res < 0)
169 goto out_unlock;
170
171 if (status != P9_LOCK_BLOCKED)
172 break;
173 if (status == P9_LOCK_BLOCKED && !IS_SETLKW(cmd))
174 break;
175 if (schedule_timeout_interruptible(v9ses->session_lock_timeout)
176 != 0)
177 break;
178 /*
179 * p9_client_lock_dotl overwrites flock.client_id with the
180 * server message, free and reuse the client name
181 */
182 if (flock.client_id != fid->clnt->name) {
183 kfree(flock.client_id);
184 flock.client_id = fid->clnt->name;
185 }
186 }
187
188 /* map 9p status to VFS status */
189 switch (status) {
190 case P9_LOCK_SUCCESS:
191 res = 0;
192 break;
193 case P9_LOCK_BLOCKED:
194 res = -EAGAIN;
195 break;
196 default:
197 WARN_ONCE(1, "unknown lock status code: %d\n", status);
198 fallthrough;
199 case P9_LOCK_ERROR:
200 case P9_LOCK_GRACE:
201 res = -ENOLCK;
202 break;
203 }
204
205out_unlock:
206 /*
207 * incase server returned error for lock request, revert
208 * it locally
209 */
210 if (res < 0 && fl->fl_type != F_UNLCK) {
211 fl_type = fl->fl_type;
212 fl->fl_type = F_UNLCK;
213 /* Even if this fails we want to return the remote error */
214 locks_lock_file_wait(filp, fl);
215 fl->fl_type = fl_type;
216 }
217 if (flock.client_id != fid->clnt->name)
218 kfree(flock.client_id);
219out:
220 return res;
221}
222
223static int v9fs_file_getlock(struct file *filp, struct file_lock *fl)
224{
225 struct p9_getlock glock;
226 struct p9_fid *fid;
227 int res = 0;
228
229 fid = filp->private_data;
230 BUG_ON(fid == NULL);
231
232 posix_test_lock(filp, fl);
233 /*
234 * if we have a conflicting lock locally, no need to validate
235 * with server
236 */
237 if (fl->fl_type != F_UNLCK)
238 return res;
239
240 /* convert posix lock to p9 tgetlock args */
241 memset(&glock, 0, sizeof(glock));
242 glock.type = P9_LOCK_TYPE_UNLCK;
243 glock.start = fl->fl_start;
244 if (fl->fl_end == OFFSET_MAX)
245 glock.length = 0;
246 else
247 glock.length = fl->fl_end - fl->fl_start + 1;
248 glock.proc_id = fl->fl_pid;
249 glock.client_id = fid->clnt->name;
250
251 res = p9_client_getlock_dotl(fid, &glock);
252 if (res < 0)
253 goto out;
254 /* map 9p lock type to os lock type */
255 switch (glock.type) {
256 case P9_LOCK_TYPE_RDLCK:
257 fl->fl_type = F_RDLCK;
258 break;
259 case P9_LOCK_TYPE_WRLCK:
260 fl->fl_type = F_WRLCK;
261 break;
262 case P9_LOCK_TYPE_UNLCK:
263 fl->fl_type = F_UNLCK;
264 break;
265 }
266 if (glock.type != P9_LOCK_TYPE_UNLCK) {
267 fl->fl_start = glock.start;
268 if (glock.length == 0)
269 fl->fl_end = OFFSET_MAX;
270 else
271 fl->fl_end = glock.start + glock.length - 1;
272 fl->fl_pid = -glock.proc_id;
273 }
274out:
275 if (glock.client_id != fid->clnt->name)
276 kfree(glock.client_id);
277 return res;
278}
279
280/**
281 * v9fs_file_lock_dotl - lock a file (or directory)
282 * @filp: file to be locked
283 * @cmd: lock command
284 * @fl: file lock structure
285 *
286 */
287
288static int v9fs_file_lock_dotl(struct file *filp, int cmd, struct file_lock *fl)
289{
290 struct inode *inode = file_inode(filp);
291 int ret = -ENOLCK;
292
293 p9_debug(P9_DEBUG_VFS, "filp: %p cmd:%d lock: %p name: %pD\n",
294 filp, cmd, fl, filp);
295
296 if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
297 filemap_write_and_wait(inode->i_mapping);
298 invalidate_mapping_pages(&inode->i_data, 0, -1);
299 }
300
301 if (IS_SETLK(cmd) || IS_SETLKW(cmd))
302 ret = v9fs_file_do_lock(filp, cmd, fl);
303 else if (IS_GETLK(cmd))
304 ret = v9fs_file_getlock(filp, fl);
305 else
306 ret = -EINVAL;
307 return ret;
308}
309
310/**
311 * v9fs_file_flock_dotl - lock a file
312 * @filp: file to be locked
313 * @cmd: lock command
314 * @fl: file lock structure
315 *
316 */
317
318static int v9fs_file_flock_dotl(struct file *filp, int cmd,
319 struct file_lock *fl)
320{
321 struct inode *inode = file_inode(filp);
322 int ret = -ENOLCK;
323
324 p9_debug(P9_DEBUG_VFS, "filp: %p cmd:%d lock: %p name: %pD\n",
325 filp, cmd, fl, filp);
326
327 if (!(fl->fl_flags & FL_FLOCK))
328 goto out_err;
329
330 if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
331 filemap_write_and_wait(inode->i_mapping);
332 invalidate_mapping_pages(&inode->i_data, 0, -1);
333 }
334 /* Convert flock to posix lock */
335 fl->fl_flags |= FL_POSIX;
336 fl->fl_flags ^= FL_FLOCK;
337
338 if (IS_SETLK(cmd) | IS_SETLKW(cmd))
339 ret = v9fs_file_do_lock(filp, cmd, fl);
340 else
341 ret = -EINVAL;
342out_err:
343 return ret;
344}
345
346/**
347 * v9fs_file_read_iter - read from a file
348 * @iocb: The operation parameters
349 * @to: The buffer to read into
350 *
351 */
352static ssize_t
353v9fs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
354{
355 struct p9_fid *fid = iocb->ki_filp->private_data;
356
357 p9_debug(P9_DEBUG_VFS, "fid %d count %zu offset %lld\n",
358 fid->fid, iov_iter_count(to), iocb->ki_pos);
359
360 if (fid->mode & P9L_DIRECT)
361 return netfs_unbuffered_read_iter(iocb, to);
362
363 p9_debug(P9_DEBUG_VFS, "(cached)\n");
364 return netfs_file_read_iter(iocb, to);
365}
366
367/*
368 * v9fs_file_splice_read - splice-read from a file
369 * @in: The 9p file to read from
370 * @ppos: Where to find/update the file position
371 * @pipe: The pipe to splice into
372 * @len: The maximum amount of data to splice
373 * @flags: SPLICE_F_* flags
374 */
375static ssize_t v9fs_file_splice_read(struct file *in, loff_t *ppos,
376 struct pipe_inode_info *pipe,
377 size_t len, unsigned int flags)
378{
379 struct p9_fid *fid = in->private_data;
380
381 p9_debug(P9_DEBUG_VFS, "fid %d count %zu offset %lld\n",
382 fid->fid, len, *ppos);
383
384 if (fid->mode & P9L_DIRECT)
385 return copy_splice_read(in, ppos, pipe, len, flags);
386 return filemap_splice_read(in, ppos, pipe, len, flags);
387}
388
389/**
390 * v9fs_file_write_iter - write to a file
391 * @iocb: The operation parameters
392 * @from: The data to write
393 *
394 */
395static ssize_t
396v9fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
397{
398 struct file *file = iocb->ki_filp;
399 struct p9_fid *fid = file->private_data;
400
401 p9_debug(P9_DEBUG_VFS, "fid %d\n", fid->fid);
402
403 if (fid->mode & (P9L_DIRECT | P9L_NOWRITECACHE))
404 return netfs_unbuffered_write_iter(iocb, from);
405
406 p9_debug(P9_DEBUG_CACHE, "(cached)\n");
407 return netfs_file_write_iter(iocb, from);
408}
409
410static int v9fs_file_fsync(struct file *filp, loff_t start, loff_t end,
411 int datasync)
412{
413 struct p9_fid *fid;
414 struct inode *inode = filp->f_mapping->host;
415 struct p9_wstat wstat;
416 int retval;
417
418 retval = file_write_and_wait_range(filp, start, end);
419 if (retval)
420 return retval;
421
422 inode_lock(inode);
423 p9_debug(P9_DEBUG_VFS, "filp %p datasync %x\n", filp, datasync);
424
425 fid = filp->private_data;
426 v9fs_blank_wstat(&wstat);
427
428 retval = p9_client_wstat(fid, &wstat);
429 inode_unlock(inode);
430
431 return retval;
432}
433
434int v9fs_file_fsync_dotl(struct file *filp, loff_t start, loff_t end,
435 int datasync)
436{
437 struct p9_fid *fid;
438 struct inode *inode = filp->f_mapping->host;
439 int retval;
440
441 retval = file_write_and_wait_range(filp, start, end);
442 if (retval)
443 return retval;
444
445 inode_lock(inode);
446 p9_debug(P9_DEBUG_VFS, "filp %p datasync %x\n", filp, datasync);
447
448 fid = filp->private_data;
449
450 retval = p9_client_fsync(fid, datasync);
451 inode_unlock(inode);
452
453 return retval;
454}
455
456static int
457v9fs_file_mmap(struct file *filp, struct vm_area_struct *vma)
458{
459 int retval;
460 struct inode *inode = file_inode(filp);
461 struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
462
463 p9_debug(P9_DEBUG_MMAP, "filp :%p\n", filp);
464
465 if (!(v9ses->cache & CACHE_WRITEBACK)) {
466 p9_debug(P9_DEBUG_CACHE, "(read-only mmap mode)");
467 return generic_file_readonly_mmap(filp, vma);
468 }
469
470 retval = generic_file_mmap(filp, vma);
471 if (!retval)
472 vma->vm_ops = &v9fs_mmap_file_vm_ops;
473
474 return retval;
475}
476
477static vm_fault_t
478v9fs_vm_page_mkwrite(struct vm_fault *vmf)
479{
480 return netfs_page_mkwrite(vmf, NULL);
481}
482
483static void v9fs_mmap_vm_close(struct vm_area_struct *vma)
484{
485 struct inode *inode;
486
487 struct writeback_control wbc = {
488 .nr_to_write = LONG_MAX,
489 .sync_mode = WB_SYNC_ALL,
490 .range_start = (loff_t)vma->vm_pgoff * PAGE_SIZE,
491 /* absolute end, byte at end included */
492 .range_end = (loff_t)vma->vm_pgoff * PAGE_SIZE +
493 (vma->vm_end - vma->vm_start - 1),
494 };
495
496 if (!(vma->vm_flags & VM_SHARED))
497 return;
498
499 p9_debug(P9_DEBUG_VFS, "9p VMA close, %p, flushing", vma);
500
501 inode = file_inode(vma->vm_file);
502 filemap_fdatawrite_wbc(inode->i_mapping, &wbc);
503}
504
505static const struct vm_operations_struct v9fs_mmap_file_vm_ops = {
506 .close = v9fs_mmap_vm_close,
507 .fault = filemap_fault,
508 .map_pages = filemap_map_pages,
509 .page_mkwrite = v9fs_vm_page_mkwrite,
510};
511
512const struct file_operations v9fs_file_operations = {
513 .llseek = generic_file_llseek,
514 .read_iter = v9fs_file_read_iter,
515 .write_iter = v9fs_file_write_iter,
516 .open = v9fs_file_open,
517 .release = v9fs_dir_release,
518 .lock = v9fs_file_lock,
519 .mmap = generic_file_readonly_mmap,
520 .splice_read = v9fs_file_splice_read,
521 .splice_write = iter_file_splice_write,
522 .fsync = v9fs_file_fsync,
523};
524
525const struct file_operations v9fs_file_operations_dotl = {
526 .llseek = generic_file_llseek,
527 .read_iter = v9fs_file_read_iter,
528 .write_iter = v9fs_file_write_iter,
529 .open = v9fs_file_open,
530 .release = v9fs_dir_release,
531 .lock = v9fs_file_lock_dotl,
532 .flock = v9fs_file_flock_dotl,
533 .mmap = v9fs_file_mmap,
534 .splice_read = v9fs_file_splice_read,
535 .splice_write = iter_file_splice_write,
536 .fsync = v9fs_file_fsync_dotl,
537};