Loading...
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 * linux/fs/9p/vfs_file.c
4 *
5 * This file contians vfs file ops for 9P2000.
6 *
7 * Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
8 * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
9 */
10
11#include <linux/module.h>
12#include <linux/errno.h>
13#include <linux/fs.h>
14#include <linux/sched.h>
15#include <linux/file.h>
16#include <linux/stat.h>
17#include <linux/string.h>
18#include <linux/inet.h>
19#include <linux/list.h>
20#include <linux/pagemap.h>
21#include <linux/utsname.h>
22#include <linux/uaccess.h>
23#include <linux/idr.h>
24#include <linux/uio.h>
25#include <linux/slab.h>
26#include <net/9p/9p.h>
27#include <net/9p/client.h>
28
29#include "v9fs.h"
30#include "v9fs_vfs.h"
31#include "fid.h"
32#include "cache.h"
33
34static const struct vm_operations_struct v9fs_file_vm_ops;
35static const struct vm_operations_struct v9fs_mmap_file_vm_ops;
36
37/**
38 * v9fs_file_open - open a file (or directory)
39 * @inode: inode to be opened
40 * @file: file being opened
41 *
42 */
43
44int v9fs_file_open(struct inode *inode, struct file *file)
45{
46 int err;
47 struct v9fs_inode *v9inode;
48 struct v9fs_session_info *v9ses;
49 struct p9_fid *fid;
50 int omode;
51
52 p9_debug(P9_DEBUG_VFS, "inode: %p file: %p\n", inode, file);
53 v9inode = V9FS_I(inode);
54 v9ses = v9fs_inode2v9ses(inode);
55 if (v9fs_proto_dotl(v9ses))
56 omode = v9fs_open_to_dotl_flags(file->f_flags);
57 else
58 omode = v9fs_uflags2omode(file->f_flags,
59 v9fs_proto_dotu(v9ses));
60 fid = file->private_data;
61 if (!fid) {
62 fid = v9fs_fid_clone(file_dentry(file));
63 if (IS_ERR(fid))
64 return PTR_ERR(fid);
65
66 err = p9_client_open(fid, omode);
67 if (err < 0) {
68 p9_client_clunk(fid);
69 return err;
70 }
71 if ((file->f_flags & O_APPEND) &&
72 (!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)))
73 generic_file_llseek(file, 0, SEEK_END);
74 }
75
76 file->private_data = fid;
77 mutex_lock(&v9inode->v_mutex);
78 if ((v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) &&
79 !v9inode->writeback_fid &&
80 ((file->f_flags & O_ACCMODE) != O_RDONLY)) {
81 /*
82 * clone a fid and add it to writeback_fid
83 * we do it during open time instead of
84 * page dirty time via write_begin/page_mkwrite
85 * because we want write after unlink usecase
86 * to work.
87 */
88 fid = v9fs_writeback_fid(file_dentry(file));
89 if (IS_ERR(fid)) {
90 err = PTR_ERR(fid);
91 mutex_unlock(&v9inode->v_mutex);
92 goto out_error;
93 }
94 v9inode->writeback_fid = (void *) fid;
95 }
96 mutex_unlock(&v9inode->v_mutex);
97 if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
98 v9fs_cache_inode_set_cookie(inode, file);
99 return 0;
100out_error:
101 p9_client_clunk(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 int res = 0;
119 struct inode *inode = file_inode(filp);
120
121 p9_debug(P9_DEBUG_VFS, "filp: %p lock: %p\n", filp, fl);
122
123 /* No mandatory locks */
124 if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
125 return -ENOLCK;
126
127 if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
128 filemap_write_and_wait(inode->i_mapping);
129 invalidate_mapping_pages(&inode->i_data, 0, -1);
130 }
131
132 return res;
133}
134
135static int v9fs_file_do_lock(struct file *filp, int cmd, struct file_lock *fl)
136{
137 struct p9_flock flock;
138 struct p9_fid *fid;
139 uint8_t status = P9_LOCK_ERROR;
140 int res = 0;
141 unsigned char fl_type;
142 struct v9fs_session_info *v9ses;
143
144 fid = filp->private_data;
145 BUG_ON(fid == NULL);
146
147 if ((fl->fl_flags & FL_POSIX) != FL_POSIX)
148 BUG();
149
150 res = locks_lock_file_wait(filp, fl);
151 if (res < 0)
152 goto out;
153
154 /* convert posix lock to p9 tlock args */
155 memset(&flock, 0, sizeof(flock));
156 /* map the lock type */
157 switch (fl->fl_type) {
158 case F_RDLCK:
159 flock.type = P9_LOCK_TYPE_RDLCK;
160 break;
161 case F_WRLCK:
162 flock.type = P9_LOCK_TYPE_WRLCK;
163 break;
164 case F_UNLCK:
165 flock.type = P9_LOCK_TYPE_UNLCK;
166 break;
167 }
168 flock.start = fl->fl_start;
169 if (fl->fl_end == OFFSET_MAX)
170 flock.length = 0;
171 else
172 flock.length = fl->fl_end - fl->fl_start + 1;
173 flock.proc_id = fl->fl_pid;
174 flock.client_id = fid->clnt->name;
175 if (IS_SETLKW(cmd))
176 flock.flags = P9_LOCK_FLAGS_BLOCK;
177
178 v9ses = v9fs_inode2v9ses(file_inode(filp));
179
180 /*
181 * if its a blocked request and we get P9_LOCK_BLOCKED as the status
182 * for lock request, keep on trying
183 */
184 for (;;) {
185 res = p9_client_lock_dotl(fid, &flock, &status);
186 if (res < 0)
187 goto out_unlock;
188
189 if (status != P9_LOCK_BLOCKED)
190 break;
191 if (status == P9_LOCK_BLOCKED && !IS_SETLKW(cmd))
192 break;
193 if (schedule_timeout_interruptible(v9ses->session_lock_timeout)
194 != 0)
195 break;
196 /*
197 * p9_client_lock_dotl overwrites flock.client_id with the
198 * server message, free and reuse the client name
199 */
200 if (flock.client_id != fid->clnt->name) {
201 kfree(flock.client_id);
202 flock.client_id = fid->clnt->name;
203 }
204 }
205
206 /* map 9p status to VFS status */
207 switch (status) {
208 case P9_LOCK_SUCCESS:
209 res = 0;
210 break;
211 case P9_LOCK_BLOCKED:
212 res = -EAGAIN;
213 break;
214 default:
215 WARN_ONCE(1, "unknown lock status code: %d\n", status);
216 fallthrough;
217 case P9_LOCK_ERROR:
218 case P9_LOCK_GRACE:
219 res = -ENOLCK;
220 break;
221 }
222
223out_unlock:
224 /*
225 * incase server returned error for lock request, revert
226 * it locally
227 */
228 if (res < 0 && fl->fl_type != F_UNLCK) {
229 fl_type = fl->fl_type;
230 fl->fl_type = F_UNLCK;
231 /* Even if this fails we want to return the remote error */
232 locks_lock_file_wait(filp, fl);
233 fl->fl_type = fl_type;
234 }
235 if (flock.client_id != fid->clnt->name)
236 kfree(flock.client_id);
237out:
238 return res;
239}
240
241static int v9fs_file_getlock(struct file *filp, struct file_lock *fl)
242{
243 struct p9_getlock glock;
244 struct p9_fid *fid;
245 int res = 0;
246
247 fid = filp->private_data;
248 BUG_ON(fid == NULL);
249
250 posix_test_lock(filp, fl);
251 /*
252 * if we have a conflicting lock locally, no need to validate
253 * with server
254 */
255 if (fl->fl_type != F_UNLCK)
256 return res;
257
258 /* convert posix lock to p9 tgetlock args */
259 memset(&glock, 0, sizeof(glock));
260 glock.type = P9_LOCK_TYPE_UNLCK;
261 glock.start = fl->fl_start;
262 if (fl->fl_end == OFFSET_MAX)
263 glock.length = 0;
264 else
265 glock.length = fl->fl_end - fl->fl_start + 1;
266 glock.proc_id = fl->fl_pid;
267 glock.client_id = fid->clnt->name;
268
269 res = p9_client_getlock_dotl(fid, &glock);
270 if (res < 0)
271 goto out;
272 /* map 9p lock type to os lock type */
273 switch (glock.type) {
274 case P9_LOCK_TYPE_RDLCK:
275 fl->fl_type = F_RDLCK;
276 break;
277 case P9_LOCK_TYPE_WRLCK:
278 fl->fl_type = F_WRLCK;
279 break;
280 case P9_LOCK_TYPE_UNLCK:
281 fl->fl_type = F_UNLCK;
282 break;
283 }
284 if (glock.type != P9_LOCK_TYPE_UNLCK) {
285 fl->fl_start = glock.start;
286 if (glock.length == 0)
287 fl->fl_end = OFFSET_MAX;
288 else
289 fl->fl_end = glock.start + glock.length - 1;
290 fl->fl_pid = -glock.proc_id;
291 }
292out:
293 if (glock.client_id != fid->clnt->name)
294 kfree(glock.client_id);
295 return res;
296}
297
298/**
299 * v9fs_file_lock_dotl - lock a file (or directory)
300 * @filp: file to be locked
301 * @cmd: lock command
302 * @fl: file lock structure
303 *
304 */
305
306static int v9fs_file_lock_dotl(struct file *filp, int cmd, struct file_lock *fl)
307{
308 struct inode *inode = file_inode(filp);
309 int ret = -ENOLCK;
310
311 p9_debug(P9_DEBUG_VFS, "filp: %p cmd:%d lock: %p name: %pD\n",
312 filp, cmd, fl, filp);
313
314 /* No mandatory locks */
315 if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
316 goto out_err;
317
318 if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
319 filemap_write_and_wait(inode->i_mapping);
320 invalidate_mapping_pages(&inode->i_data, 0, -1);
321 }
322
323 if (IS_SETLK(cmd) || IS_SETLKW(cmd))
324 ret = v9fs_file_do_lock(filp, cmd, fl);
325 else if (IS_GETLK(cmd))
326 ret = v9fs_file_getlock(filp, fl);
327 else
328 ret = -EINVAL;
329out_err:
330 return ret;
331}
332
333/**
334 * v9fs_file_flock_dotl - lock a file
335 * @filp: file to be locked
336 * @cmd: lock command
337 * @fl: file lock structure
338 *
339 */
340
341static int v9fs_file_flock_dotl(struct file *filp, int cmd,
342 struct file_lock *fl)
343{
344 struct inode *inode = file_inode(filp);
345 int ret = -ENOLCK;
346
347 p9_debug(P9_DEBUG_VFS, "filp: %p cmd:%d lock: %p name: %pD\n",
348 filp, cmd, fl, filp);
349
350 /* No mandatory locks */
351 if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
352 goto out_err;
353
354 if (!(fl->fl_flags & FL_FLOCK))
355 goto out_err;
356
357 if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
358 filemap_write_and_wait(inode->i_mapping);
359 invalidate_mapping_pages(&inode->i_data, 0, -1);
360 }
361 /* Convert flock to posix lock */
362 fl->fl_flags |= FL_POSIX;
363 fl->fl_flags ^= FL_FLOCK;
364
365 if (IS_SETLK(cmd) | IS_SETLKW(cmd))
366 ret = v9fs_file_do_lock(filp, cmd, fl);
367 else
368 ret = -EINVAL;
369out_err:
370 return ret;
371}
372
373/**
374 * v9fs_file_read - read from a file
375 * @filp: file pointer to read
376 * @udata: user data buffer to read data into
377 * @count: size of buffer
378 * @offset: offset at which to read data
379 *
380 */
381
382static ssize_t
383v9fs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
384{
385 struct p9_fid *fid = iocb->ki_filp->private_data;
386 int ret, err = 0;
387
388 p9_debug(P9_DEBUG_VFS, "count %zu offset %lld\n",
389 iov_iter_count(to), iocb->ki_pos);
390
391 if (iocb->ki_filp->f_flags & O_NONBLOCK)
392 ret = p9_client_read_once(fid, iocb->ki_pos, to, &err);
393 else
394 ret = p9_client_read(fid, iocb->ki_pos, to, &err);
395 if (!ret)
396 return err;
397
398 iocb->ki_pos += ret;
399 return ret;
400}
401
402/**
403 * v9fs_file_write - write to a file
404 * @filp: file pointer to write
405 * @data: data buffer to write data from
406 * @count: size of buffer
407 * @offset: offset at which to write data
408 *
409 */
410static ssize_t
411v9fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
412{
413 struct file *file = iocb->ki_filp;
414 ssize_t retval;
415 loff_t origin;
416 int err = 0;
417
418 retval = generic_write_checks(iocb, from);
419 if (retval <= 0)
420 return retval;
421
422 origin = iocb->ki_pos;
423 retval = p9_client_write(file->private_data, iocb->ki_pos, from, &err);
424 if (retval > 0) {
425 struct inode *inode = file_inode(file);
426 loff_t i_size;
427 unsigned long pg_start, pg_end;
428 pg_start = origin >> PAGE_SHIFT;
429 pg_end = (origin + retval - 1) >> PAGE_SHIFT;
430 if (inode->i_mapping && inode->i_mapping->nrpages)
431 invalidate_inode_pages2_range(inode->i_mapping,
432 pg_start, pg_end);
433 iocb->ki_pos += retval;
434 i_size = i_size_read(inode);
435 if (iocb->ki_pos > i_size) {
436 inode_add_bytes(inode, iocb->ki_pos - i_size);
437 /*
438 * Need to serialize against i_size_write() in
439 * v9fs_stat2inode()
440 */
441 v9fs_i_size_write(inode, iocb->ki_pos);
442 }
443 return retval;
444 }
445 return err;
446}
447
448static int v9fs_file_fsync(struct file *filp, loff_t start, loff_t end,
449 int datasync)
450{
451 struct p9_fid *fid;
452 struct inode *inode = filp->f_mapping->host;
453 struct p9_wstat wstat;
454 int retval;
455
456 retval = file_write_and_wait_range(filp, start, end);
457 if (retval)
458 return retval;
459
460 inode_lock(inode);
461 p9_debug(P9_DEBUG_VFS, "filp %p datasync %x\n", filp, datasync);
462
463 fid = filp->private_data;
464 v9fs_blank_wstat(&wstat);
465
466 retval = p9_client_wstat(fid, &wstat);
467 inode_unlock(inode);
468
469 return retval;
470}
471
472int v9fs_file_fsync_dotl(struct file *filp, loff_t start, loff_t end,
473 int datasync)
474{
475 struct p9_fid *fid;
476 struct inode *inode = filp->f_mapping->host;
477 int retval;
478
479 retval = file_write_and_wait_range(filp, start, end);
480 if (retval)
481 return retval;
482
483 inode_lock(inode);
484 p9_debug(P9_DEBUG_VFS, "filp %p datasync %x\n", filp, datasync);
485
486 fid = filp->private_data;
487
488 retval = p9_client_fsync(fid, datasync);
489 inode_unlock(inode);
490
491 return retval;
492}
493
494static int
495v9fs_file_mmap(struct file *filp, struct vm_area_struct *vma)
496{
497 int retval;
498
499
500 retval = generic_file_mmap(filp, vma);
501 if (!retval)
502 vma->vm_ops = &v9fs_file_vm_ops;
503
504 return retval;
505}
506
507static int
508v9fs_mmap_file_mmap(struct file *filp, struct vm_area_struct *vma)
509{
510 int retval;
511 struct inode *inode;
512 struct v9fs_inode *v9inode;
513 struct p9_fid *fid;
514
515 inode = file_inode(filp);
516 v9inode = V9FS_I(inode);
517 mutex_lock(&v9inode->v_mutex);
518 if (!v9inode->writeback_fid &&
519 (vma->vm_flags & VM_SHARED) &&
520 (vma->vm_flags & VM_WRITE)) {
521 /*
522 * clone a fid and add it to writeback_fid
523 * we do it during mmap instead of
524 * page dirty time via write_begin/page_mkwrite
525 * because we want write after unlink usecase
526 * to work.
527 */
528 fid = v9fs_writeback_fid(file_dentry(filp));
529 if (IS_ERR(fid)) {
530 retval = PTR_ERR(fid);
531 mutex_unlock(&v9inode->v_mutex);
532 return retval;
533 }
534 v9inode->writeback_fid = (void *) fid;
535 }
536 mutex_unlock(&v9inode->v_mutex);
537
538 retval = generic_file_mmap(filp, vma);
539 if (!retval)
540 vma->vm_ops = &v9fs_mmap_file_vm_ops;
541
542 return retval;
543}
544
545static vm_fault_t
546v9fs_vm_page_mkwrite(struct vm_fault *vmf)
547{
548 struct v9fs_inode *v9inode;
549 struct page *page = vmf->page;
550 struct file *filp = vmf->vma->vm_file;
551 struct inode *inode = file_inode(filp);
552
553
554 p9_debug(P9_DEBUG_VFS, "page %p fid %lx\n",
555 page, (unsigned long)filp->private_data);
556
557 /* Update file times before taking page lock */
558 file_update_time(filp);
559
560 v9inode = V9FS_I(inode);
561 /* make sure the cache has finished storing the page */
562 v9fs_fscache_wait_on_page_write(inode, page);
563 BUG_ON(!v9inode->writeback_fid);
564 lock_page(page);
565 if (page->mapping != inode->i_mapping)
566 goto out_unlock;
567 wait_for_stable_page(page);
568
569 return VM_FAULT_LOCKED;
570out_unlock:
571 unlock_page(page);
572 return VM_FAULT_NOPAGE;
573}
574
575/**
576 * v9fs_mmap_file_read - read from a file
577 * @filp: file pointer to read
578 * @data: user data buffer to read data into
579 * @count: size of buffer
580 * @offset: offset at which to read data
581 *
582 */
583static ssize_t
584v9fs_mmap_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
585{
586 /* TODO: Check if there are dirty pages */
587 return v9fs_file_read_iter(iocb, to);
588}
589
590/**
591 * v9fs_mmap_file_write - write to a file
592 * @filp: file pointer to write
593 * @data: data buffer to write data from
594 * @count: size of buffer
595 * @offset: offset at which to write data
596 *
597 */
598static ssize_t
599v9fs_mmap_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
600{
601 /*
602 * TODO: invalidate mmaps on filp's inode between
603 * offset and offset+count
604 */
605 return v9fs_file_write_iter(iocb, from);
606}
607
608static void v9fs_mmap_vm_close(struct vm_area_struct *vma)
609{
610 struct inode *inode;
611
612 struct writeback_control wbc = {
613 .nr_to_write = LONG_MAX,
614 .sync_mode = WB_SYNC_ALL,
615 .range_start = vma->vm_pgoff * PAGE_SIZE,
616 /* absolute end, byte at end included */
617 .range_end = vma->vm_pgoff * PAGE_SIZE +
618 (vma->vm_end - vma->vm_start - 1),
619 };
620
621 if (!(vma->vm_flags & VM_SHARED))
622 return;
623
624 p9_debug(P9_DEBUG_VFS, "9p VMA close, %p, flushing", vma);
625
626 inode = file_inode(vma->vm_file);
627
628 if (!mapping_cap_writeback_dirty(inode->i_mapping))
629 wbc.nr_to_write = 0;
630
631 might_sleep();
632 sync_inode(inode, &wbc);
633}
634
635
636static const struct vm_operations_struct v9fs_file_vm_ops = {
637 .fault = filemap_fault,
638 .map_pages = filemap_map_pages,
639 .page_mkwrite = v9fs_vm_page_mkwrite,
640};
641
642static const struct vm_operations_struct v9fs_mmap_file_vm_ops = {
643 .close = v9fs_mmap_vm_close,
644 .fault = filemap_fault,
645 .map_pages = filemap_map_pages,
646 .page_mkwrite = v9fs_vm_page_mkwrite,
647};
648
649
650const struct file_operations v9fs_cached_file_operations = {
651 .llseek = generic_file_llseek,
652 .read_iter = generic_file_read_iter,
653 .write_iter = generic_file_write_iter,
654 .open = v9fs_file_open,
655 .release = v9fs_dir_release,
656 .lock = v9fs_file_lock,
657 .mmap = v9fs_file_mmap,
658 .fsync = v9fs_file_fsync,
659};
660
661const struct file_operations v9fs_cached_file_operations_dotl = {
662 .llseek = generic_file_llseek,
663 .read_iter = generic_file_read_iter,
664 .write_iter = generic_file_write_iter,
665 .open = v9fs_file_open,
666 .release = v9fs_dir_release,
667 .lock = v9fs_file_lock_dotl,
668 .flock = v9fs_file_flock_dotl,
669 .mmap = v9fs_file_mmap,
670 .fsync = v9fs_file_fsync_dotl,
671};
672
673const struct file_operations v9fs_file_operations = {
674 .llseek = generic_file_llseek,
675 .read_iter = v9fs_file_read_iter,
676 .write_iter = v9fs_file_write_iter,
677 .open = v9fs_file_open,
678 .release = v9fs_dir_release,
679 .lock = v9fs_file_lock,
680 .mmap = generic_file_readonly_mmap,
681 .fsync = v9fs_file_fsync,
682};
683
684const struct file_operations v9fs_file_operations_dotl = {
685 .llseek = generic_file_llseek,
686 .read_iter = v9fs_file_read_iter,
687 .write_iter = v9fs_file_write_iter,
688 .open = v9fs_file_open,
689 .release = v9fs_dir_release,
690 .lock = v9fs_file_lock_dotl,
691 .flock = v9fs_file_flock_dotl,
692 .mmap = generic_file_readonly_mmap,
693 .fsync = v9fs_file_fsync_dotl,
694};
695
696const struct file_operations v9fs_mmap_file_operations = {
697 .llseek = generic_file_llseek,
698 .read_iter = v9fs_mmap_file_read_iter,
699 .write_iter = v9fs_mmap_file_write_iter,
700 .open = v9fs_file_open,
701 .release = v9fs_dir_release,
702 .lock = v9fs_file_lock,
703 .mmap = v9fs_mmap_file_mmap,
704 .fsync = v9fs_file_fsync,
705};
706
707const struct file_operations v9fs_mmap_file_operations_dotl = {
708 .llseek = generic_file_llseek,
709 .read_iter = v9fs_mmap_file_read_iter,
710 .write_iter = v9fs_mmap_file_write_iter,
711 .open = v9fs_file_open,
712 .release = v9fs_dir_release,
713 .lock = v9fs_file_lock_dotl,
714 .flock = v9fs_file_flock_dotl,
715 .mmap = v9fs_mmap_file_mmap,
716 .fsync = v9fs_file_fsync_dotl,
717};