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1/*
2 * linux/fs/9p/vfs_file.c
3 *
4 * This file contians vfs file ops for 9P2000.
5 *
6 * Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
7 * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2
11 * as published by the Free Software Foundation.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to:
20 * Free Software Foundation
21 * 51 Franklin Street, Fifth Floor
22 * Boston, MA 02111-1301 USA
23 *
24 */
25
26#include <linux/module.h>
27#include <linux/errno.h>
28#include <linux/fs.h>
29#include <linux/sched.h>
30#include <linux/file.h>
31#include <linux/stat.h>
32#include <linux/string.h>
33#include <linux/inet.h>
34#include <linux/list.h>
35#include <linux/pagemap.h>
36#include <linux/utsname.h>
37#include <asm/uaccess.h>
38#include <linux/idr.h>
39#include <linux/uio.h>
40#include <linux/slab.h>
41#include <net/9p/9p.h>
42#include <net/9p/client.h>
43
44#include "v9fs.h"
45#include "v9fs_vfs.h"
46#include "fid.h"
47#include "cache.h"
48
49static const struct vm_operations_struct v9fs_file_vm_ops;
50static const struct vm_operations_struct v9fs_mmap_file_vm_ops;
51
52/**
53 * v9fs_file_open - open a file (or directory)
54 * @inode: inode to be opened
55 * @file: file being opened
56 *
57 */
58
59int v9fs_file_open(struct inode *inode, struct file *file)
60{
61 int err;
62 struct v9fs_inode *v9inode;
63 struct v9fs_session_info *v9ses;
64 struct p9_fid *fid;
65 int omode;
66
67 p9_debug(P9_DEBUG_VFS, "inode: %p file: %p\n", inode, file);
68 v9inode = V9FS_I(inode);
69 v9ses = v9fs_inode2v9ses(inode);
70 if (v9fs_proto_dotl(v9ses))
71 omode = v9fs_open_to_dotl_flags(file->f_flags);
72 else
73 omode = v9fs_uflags2omode(file->f_flags,
74 v9fs_proto_dotu(v9ses));
75 fid = file->private_data;
76 if (!fid) {
77 fid = v9fs_fid_clone(file->f_path.dentry);
78 if (IS_ERR(fid))
79 return PTR_ERR(fid);
80
81 err = p9_client_open(fid, omode);
82 if (err < 0) {
83 p9_client_clunk(fid);
84 return err;
85 }
86 if ((file->f_flags & O_APPEND) &&
87 (!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)))
88 generic_file_llseek(file, 0, SEEK_END);
89 }
90
91 file->private_data = fid;
92 mutex_lock(&v9inode->v_mutex);
93 if ((v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) &&
94 !v9inode->writeback_fid &&
95 ((file->f_flags & O_ACCMODE) != O_RDONLY)) {
96 /*
97 * clone a fid and add it to writeback_fid
98 * we do it during open time instead of
99 * page dirty time via write_begin/page_mkwrite
100 * because we want write after unlink usecase
101 * to work.
102 */
103 fid = v9fs_writeback_fid(file->f_path.dentry);
104 if (IS_ERR(fid)) {
105 err = PTR_ERR(fid);
106 mutex_unlock(&v9inode->v_mutex);
107 goto out_error;
108 }
109 v9inode->writeback_fid = (void *) fid;
110 }
111 mutex_unlock(&v9inode->v_mutex);
112 if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
113 v9fs_cache_inode_set_cookie(inode, file);
114 return 0;
115out_error:
116 p9_client_clunk(file->private_data);
117 file->private_data = NULL;
118 return err;
119}
120
121/**
122 * v9fs_file_lock - lock a file (or directory)
123 * @filp: file to be locked
124 * @cmd: lock command
125 * @fl: file lock structure
126 *
127 * Bugs: this looks like a local only lock, we should extend into 9P
128 * by using open exclusive
129 */
130
131static int v9fs_file_lock(struct file *filp, int cmd, struct file_lock *fl)
132{
133 int res = 0;
134 struct inode *inode = file_inode(filp);
135
136 p9_debug(P9_DEBUG_VFS, "filp: %p lock: %p\n", filp, fl);
137
138 /* No mandatory locks */
139 if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
140 return -ENOLCK;
141
142 if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
143 filemap_write_and_wait(inode->i_mapping);
144 invalidate_mapping_pages(&inode->i_data, 0, -1);
145 }
146
147 return res;
148}
149
150static int v9fs_file_do_lock(struct file *filp, int cmd, struct file_lock *fl)
151{
152 struct p9_flock flock;
153 struct p9_fid *fid;
154 uint8_t status = P9_LOCK_ERROR;
155 int res = 0;
156 unsigned char fl_type;
157
158 fid = filp->private_data;
159 BUG_ON(fid == NULL);
160
161 if ((fl->fl_flags & FL_POSIX) != FL_POSIX)
162 BUG();
163
164 res = locks_lock_file_wait(filp, fl);
165 if (res < 0)
166 goto out;
167
168 /* convert posix lock to p9 tlock args */
169 memset(&flock, 0, sizeof(flock));
170 /* map the lock type */
171 switch (fl->fl_type) {
172 case F_RDLCK:
173 flock.type = P9_LOCK_TYPE_RDLCK;
174 break;
175 case F_WRLCK:
176 flock.type = P9_LOCK_TYPE_WRLCK;
177 break;
178 case F_UNLCK:
179 flock.type = P9_LOCK_TYPE_UNLCK;
180 break;
181 }
182 flock.start = fl->fl_start;
183 if (fl->fl_end == OFFSET_MAX)
184 flock.length = 0;
185 else
186 flock.length = fl->fl_end - fl->fl_start + 1;
187 flock.proc_id = fl->fl_pid;
188 flock.client_id = fid->clnt->name;
189 if (IS_SETLKW(cmd))
190 flock.flags = P9_LOCK_FLAGS_BLOCK;
191
192 /*
193 * if its a blocked request and we get P9_LOCK_BLOCKED as the status
194 * for lock request, keep on trying
195 */
196 for (;;) {
197 res = p9_client_lock_dotl(fid, &flock, &status);
198 if (res < 0)
199 goto out_unlock;
200
201 if (status != P9_LOCK_BLOCKED)
202 break;
203 if (status == P9_LOCK_BLOCKED && !IS_SETLKW(cmd))
204 break;
205 if (schedule_timeout_interruptible(P9_LOCK_TIMEOUT) != 0)
206 break;
207 }
208
209 /* map 9p status to VFS status */
210 switch (status) {
211 case P9_LOCK_SUCCESS:
212 res = 0;
213 break;
214 case P9_LOCK_BLOCKED:
215 res = -EAGAIN;
216 break;
217 default:
218 WARN_ONCE(1, "unknown lock status code: %d\n", status);
219 /* fallthough */
220 case P9_LOCK_ERROR:
221 case P9_LOCK_GRACE:
222 res = -ENOLCK;
223 break;
224 }
225
226out_unlock:
227 /*
228 * incase server returned error for lock request, revert
229 * it locally
230 */
231 if (res < 0 && fl->fl_type != F_UNLCK) {
232 fl_type = fl->fl_type;
233 fl->fl_type = F_UNLCK;
234 /* Even if this fails we want to return the remote error */
235 locks_lock_file_wait(filp, fl);
236 fl->fl_type = fl_type;
237 }
238out:
239 return res;
240}
241
242static int v9fs_file_getlock(struct file *filp, struct file_lock *fl)
243{
244 struct p9_getlock glock;
245 struct p9_fid *fid;
246 int res = 0;
247
248 fid = filp->private_data;
249 BUG_ON(fid == NULL);
250
251 posix_test_lock(filp, fl);
252 /*
253 * if we have a conflicting lock locally, no need to validate
254 * with server
255 */
256 if (fl->fl_type != F_UNLCK)
257 return res;
258
259 /* convert posix lock to p9 tgetlock args */
260 memset(&glock, 0, sizeof(glock));
261 glock.type = P9_LOCK_TYPE_UNLCK;
262 glock.start = fl->fl_start;
263 if (fl->fl_end == OFFSET_MAX)
264 glock.length = 0;
265 else
266 glock.length = fl->fl_end - fl->fl_start + 1;
267 glock.proc_id = fl->fl_pid;
268 glock.client_id = fid->clnt->name;
269
270 res = p9_client_getlock_dotl(fid, &glock);
271 if (res < 0)
272 return res;
273 /* map 9p lock type to os lock type */
274 switch (glock.type) {
275 case P9_LOCK_TYPE_RDLCK:
276 fl->fl_type = F_RDLCK;
277 break;
278 case P9_LOCK_TYPE_WRLCK:
279 fl->fl_type = F_WRLCK;
280 break;
281 case P9_LOCK_TYPE_UNLCK:
282 fl->fl_type = F_UNLCK;
283 break;
284 }
285 if (glock.type != P9_LOCK_TYPE_UNLCK) {
286 fl->fl_start = glock.start;
287 if (glock.length == 0)
288 fl->fl_end = OFFSET_MAX;
289 else
290 fl->fl_end = glock.start + glock.length - 1;
291 fl->fl_pid = glock.proc_id;
292 }
293 kfree(glock.client_id);
294 return res;
295}
296
297/**
298 * v9fs_file_lock_dotl - lock a file (or directory)
299 * @filp: file to be locked
300 * @cmd: lock command
301 * @fl: file lock structure
302 *
303 */
304
305static int v9fs_file_lock_dotl(struct file *filp, int cmd, struct file_lock *fl)
306{
307 struct inode *inode = file_inode(filp);
308 int ret = -ENOLCK;
309
310 p9_debug(P9_DEBUG_VFS, "filp: %p cmd:%d lock: %p name: %pD\n",
311 filp, cmd, fl, filp);
312
313 /* No mandatory locks */
314 if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
315 goto out_err;
316
317 if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
318 filemap_write_and_wait(inode->i_mapping);
319 invalidate_mapping_pages(&inode->i_data, 0, -1);
320 }
321
322 if (IS_SETLK(cmd) || IS_SETLKW(cmd))
323 ret = v9fs_file_do_lock(filp, cmd, fl);
324 else if (IS_GETLK(cmd))
325 ret = v9fs_file_getlock(filp, fl);
326 else
327 ret = -EINVAL;
328out_err:
329 return ret;
330}
331
332/**
333 * v9fs_file_flock_dotl - lock a file
334 * @filp: file to be locked
335 * @cmd: lock command
336 * @fl: file lock structure
337 *
338 */
339
340static int v9fs_file_flock_dotl(struct file *filp, int cmd,
341 struct file_lock *fl)
342{
343 struct inode *inode = file_inode(filp);
344 int ret = -ENOLCK;
345
346 p9_debug(P9_DEBUG_VFS, "filp: %p cmd:%d lock: %p name: %pD\n",
347 filp, cmd, fl, filp);
348
349 /* No mandatory locks */
350 if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
351 goto out_err;
352
353 if (!(fl->fl_flags & FL_FLOCK))
354 goto out_err;
355
356 if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
357 filemap_write_and_wait(inode->i_mapping);
358 invalidate_mapping_pages(&inode->i_data, 0, -1);
359 }
360 /* Convert flock to posix lock */
361 fl->fl_flags |= FL_POSIX;
362 fl->fl_flags ^= FL_FLOCK;
363
364 if (IS_SETLK(cmd) | IS_SETLKW(cmd))
365 ret = v9fs_file_do_lock(filp, cmd, fl);
366 else
367 ret = -EINVAL;
368out_err:
369 return ret;
370}
371
372/**
373 * v9fs_file_read - read from a file
374 * @filp: file pointer to read
375 * @udata: user data buffer to read data into
376 * @count: size of buffer
377 * @offset: offset at which to read data
378 *
379 */
380
381static ssize_t
382v9fs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
383{
384 struct p9_fid *fid = iocb->ki_filp->private_data;
385 int ret, err = 0;
386
387 p9_debug(P9_DEBUG_VFS, "count %zu offset %lld\n",
388 iov_iter_count(to), iocb->ki_pos);
389
390 ret = p9_client_read(fid, iocb->ki_pos, to, &err);
391 if (!ret)
392 return err;
393
394 iocb->ki_pos += ret;
395 return ret;
396}
397
398/**
399 * v9fs_file_write - write to a file
400 * @filp: file pointer to write
401 * @data: data buffer to write data from
402 * @count: size of buffer
403 * @offset: offset at which to write data
404 *
405 */
406static ssize_t
407v9fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
408{
409 struct file *file = iocb->ki_filp;
410 ssize_t retval;
411 loff_t origin;
412 int err = 0;
413
414 retval = generic_write_checks(iocb, from);
415 if (retval <= 0)
416 return retval;
417
418 origin = iocb->ki_pos;
419 retval = p9_client_write(file->private_data, iocb->ki_pos, from, &err);
420 if (retval > 0) {
421 struct inode *inode = file_inode(file);
422 loff_t i_size;
423 unsigned long pg_start, pg_end;
424 pg_start = origin >> PAGE_SHIFT;
425 pg_end = (origin + retval - 1) >> PAGE_SHIFT;
426 if (inode->i_mapping && inode->i_mapping->nrpages)
427 invalidate_inode_pages2_range(inode->i_mapping,
428 pg_start, pg_end);
429 iocb->ki_pos += retval;
430 i_size = i_size_read(inode);
431 if (iocb->ki_pos > i_size) {
432 inode_add_bytes(inode, iocb->ki_pos - i_size);
433 i_size_write(inode, iocb->ki_pos);
434 }
435 return retval;
436 }
437 return err;
438}
439
440static int v9fs_file_fsync(struct file *filp, loff_t start, loff_t end,
441 int datasync)
442{
443 struct p9_fid *fid;
444 struct inode *inode = filp->f_mapping->host;
445 struct p9_wstat wstat;
446 int retval;
447
448 retval = filemap_write_and_wait_range(inode->i_mapping, start, end);
449 if (retval)
450 return retval;
451
452 inode_lock(inode);
453 p9_debug(P9_DEBUG_VFS, "filp %p datasync %x\n", filp, datasync);
454
455 fid = filp->private_data;
456 v9fs_blank_wstat(&wstat);
457
458 retval = p9_client_wstat(fid, &wstat);
459 inode_unlock(inode);
460
461 return retval;
462}
463
464int v9fs_file_fsync_dotl(struct file *filp, loff_t start, loff_t end,
465 int datasync)
466{
467 struct p9_fid *fid;
468 struct inode *inode = filp->f_mapping->host;
469 int retval;
470
471 retval = filemap_write_and_wait_range(inode->i_mapping, start, end);
472 if (retval)
473 return retval;
474
475 inode_lock(inode);
476 p9_debug(P9_DEBUG_VFS, "filp %p datasync %x\n", filp, datasync);
477
478 fid = filp->private_data;
479
480 retval = p9_client_fsync(fid, datasync);
481 inode_unlock(inode);
482
483 return retval;
484}
485
486static int
487v9fs_file_mmap(struct file *filp, struct vm_area_struct *vma)
488{
489 int retval;
490
491
492 retval = generic_file_mmap(filp, vma);
493 if (!retval)
494 vma->vm_ops = &v9fs_file_vm_ops;
495
496 return retval;
497}
498
499static int
500v9fs_mmap_file_mmap(struct file *filp, struct vm_area_struct *vma)
501{
502 int retval;
503 struct inode *inode;
504 struct v9fs_inode *v9inode;
505 struct p9_fid *fid;
506
507 inode = file_inode(filp);
508 v9inode = V9FS_I(inode);
509 mutex_lock(&v9inode->v_mutex);
510 if (!v9inode->writeback_fid &&
511 (vma->vm_flags & VM_WRITE)) {
512 /*
513 * clone a fid and add it to writeback_fid
514 * we do it during mmap instead of
515 * page dirty time via write_begin/page_mkwrite
516 * because we want write after unlink usecase
517 * to work.
518 */
519 fid = v9fs_writeback_fid(filp->f_path.dentry);
520 if (IS_ERR(fid)) {
521 retval = PTR_ERR(fid);
522 mutex_unlock(&v9inode->v_mutex);
523 return retval;
524 }
525 v9inode->writeback_fid = (void *) fid;
526 }
527 mutex_unlock(&v9inode->v_mutex);
528
529 retval = generic_file_mmap(filp, vma);
530 if (!retval)
531 vma->vm_ops = &v9fs_mmap_file_vm_ops;
532
533 return retval;
534}
535
536static int
537v9fs_vm_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
538{
539 struct v9fs_inode *v9inode;
540 struct page *page = vmf->page;
541 struct file *filp = vma->vm_file;
542 struct inode *inode = file_inode(filp);
543
544
545 p9_debug(P9_DEBUG_VFS, "page %p fid %lx\n",
546 page, (unsigned long)filp->private_data);
547
548 /* Update file times before taking page lock */
549 file_update_time(filp);
550
551 v9inode = V9FS_I(inode);
552 /* make sure the cache has finished storing the page */
553 v9fs_fscache_wait_on_page_write(inode, page);
554 BUG_ON(!v9inode->writeback_fid);
555 lock_page(page);
556 if (page->mapping != inode->i_mapping)
557 goto out_unlock;
558 wait_for_stable_page(page);
559
560 return VM_FAULT_LOCKED;
561out_unlock:
562 unlock_page(page);
563 return VM_FAULT_NOPAGE;
564}
565
566/**
567 * v9fs_mmap_file_read - read from a file
568 * @filp: file pointer to read
569 * @data: user data buffer to read data into
570 * @count: size of buffer
571 * @offset: offset at which to read data
572 *
573 */
574static ssize_t
575v9fs_mmap_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
576{
577 /* TODO: Check if there are dirty pages */
578 return v9fs_file_read_iter(iocb, to);
579}
580
581/**
582 * v9fs_mmap_file_write - write to a file
583 * @filp: file pointer to write
584 * @data: data buffer to write data from
585 * @count: size of buffer
586 * @offset: offset at which to write data
587 *
588 */
589static ssize_t
590v9fs_mmap_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
591{
592 /*
593 * TODO: invalidate mmaps on filp's inode between
594 * offset and offset+count
595 */
596 return v9fs_file_write_iter(iocb, from);
597}
598
599static void v9fs_mmap_vm_close(struct vm_area_struct *vma)
600{
601 struct inode *inode;
602
603 struct writeback_control wbc = {
604 .nr_to_write = LONG_MAX,
605 .sync_mode = WB_SYNC_ALL,
606 .range_start = vma->vm_pgoff * PAGE_SIZE,
607 /* absolute end, byte at end included */
608 .range_end = vma->vm_pgoff * PAGE_SIZE +
609 (vma->vm_end - vma->vm_start - 1),
610 };
611
612
613 p9_debug(P9_DEBUG_VFS, "9p VMA close, %p, flushing", vma);
614
615 inode = file_inode(vma->vm_file);
616
617 if (!mapping_cap_writeback_dirty(inode->i_mapping))
618 wbc.nr_to_write = 0;
619
620 might_sleep();
621 sync_inode(inode, &wbc);
622}
623
624
625static const struct vm_operations_struct v9fs_file_vm_ops = {
626 .fault = filemap_fault,
627 .map_pages = filemap_map_pages,
628 .page_mkwrite = v9fs_vm_page_mkwrite,
629};
630
631static const struct vm_operations_struct v9fs_mmap_file_vm_ops = {
632 .close = v9fs_mmap_vm_close,
633 .fault = filemap_fault,
634 .map_pages = filemap_map_pages,
635 .page_mkwrite = v9fs_vm_page_mkwrite,
636};
637
638
639const struct file_operations v9fs_cached_file_operations = {
640 .llseek = generic_file_llseek,
641 .read_iter = generic_file_read_iter,
642 .write_iter = generic_file_write_iter,
643 .open = v9fs_file_open,
644 .release = v9fs_dir_release,
645 .lock = v9fs_file_lock,
646 .mmap = v9fs_file_mmap,
647 .fsync = v9fs_file_fsync,
648};
649
650const struct file_operations v9fs_cached_file_operations_dotl = {
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_dotl,
657 .flock = v9fs_file_flock_dotl,
658 .mmap = v9fs_file_mmap,
659 .fsync = v9fs_file_fsync_dotl,
660};
661
662const struct file_operations v9fs_file_operations = {
663 .llseek = generic_file_llseek,
664 .read_iter = v9fs_file_read_iter,
665 .write_iter = v9fs_file_write_iter,
666 .open = v9fs_file_open,
667 .release = v9fs_dir_release,
668 .lock = v9fs_file_lock,
669 .mmap = generic_file_readonly_mmap,
670 .fsync = v9fs_file_fsync,
671};
672
673const struct file_operations v9fs_file_operations_dotl = {
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_dotl,
680 .flock = v9fs_file_flock_dotl,
681 .mmap = generic_file_readonly_mmap,
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 .fsync = v9fs_file_fsync,
694};
695
696const struct file_operations v9fs_mmap_file_operations_dotl = {
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_dotl,
703 .flock = v9fs_file_flock_dotl,
704 .mmap = v9fs_mmap_file_mmap,
705 .fsync = v9fs_file_fsync_dotl,
706};
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};