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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 * 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, *writeback_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 writeback_fid = v9fs_writeback_fid(file_dentry(file));
89 if (IS_ERR(writeback_fid)) {
90 err = PTR_ERR(writeback_fid);
91 mutex_unlock(&v9inode->v_mutex);
92 goto out_error;
93 }
94 v9inode->writeback_fid = (void *) writeback_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 v9fs_open_fid_add(inode, fid);
100 return 0;
101out_error:
102 p9_client_clunk(file->private_data);
103 file->private_data = NULL;
104 return err;
105}
106
107/**
108 * v9fs_file_lock - lock a file (or directory)
109 * @filp: file to be locked
110 * @cmd: lock command
111 * @fl: file lock structure
112 *
113 * Bugs: this looks like a local only lock, we should extend into 9P
114 * by using open exclusive
115 */
116
117static int v9fs_file_lock(struct file *filp, int cmd, struct file_lock *fl)
118{
119 int res = 0;
120 struct inode *inode = file_inode(filp);
121
122 p9_debug(P9_DEBUG_VFS, "filp: %p lock: %p\n", filp, fl);
123
124 /* No mandatory locks */
125 if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
126 return -ENOLCK;
127
128 if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
129 filemap_write_and_wait(inode->i_mapping);
130 invalidate_mapping_pages(&inode->i_data, 0, -1);
131 }
132
133 return res;
134}
135
136static int v9fs_file_do_lock(struct file *filp, int cmd, struct file_lock *fl)
137{
138 struct p9_flock flock;
139 struct p9_fid *fid;
140 uint8_t status = P9_LOCK_ERROR;
141 int res = 0;
142 unsigned char fl_type;
143 struct v9fs_session_info *v9ses;
144
145 fid = filp->private_data;
146 BUG_ON(fid == NULL);
147
148 if ((fl->fl_flags & FL_POSIX) != FL_POSIX)
149 BUG();
150
151 res = locks_lock_file_wait(filp, fl);
152 if (res < 0)
153 goto out;
154
155 /* convert posix lock to p9 tlock args */
156 memset(&flock, 0, sizeof(flock));
157 /* map the lock type */
158 switch (fl->fl_type) {
159 case F_RDLCK:
160 flock.type = P9_LOCK_TYPE_RDLCK;
161 break;
162 case F_WRLCK:
163 flock.type = P9_LOCK_TYPE_WRLCK;
164 break;
165 case F_UNLCK:
166 flock.type = P9_LOCK_TYPE_UNLCK;
167 break;
168 }
169 flock.start = fl->fl_start;
170 if (fl->fl_end == OFFSET_MAX)
171 flock.length = 0;
172 else
173 flock.length = fl->fl_end - fl->fl_start + 1;
174 flock.proc_id = fl->fl_pid;
175 flock.client_id = fid->clnt->name;
176 if (IS_SETLKW(cmd))
177 flock.flags = P9_LOCK_FLAGS_BLOCK;
178
179 v9ses = v9fs_inode2v9ses(file_inode(filp));
180
181 /*
182 * if its a blocked request and we get P9_LOCK_BLOCKED as the status
183 * for lock request, keep on trying
184 */
185 for (;;) {
186 res = p9_client_lock_dotl(fid, &flock, &status);
187 if (res < 0)
188 goto out_unlock;
189
190 if (status != P9_LOCK_BLOCKED)
191 break;
192 if (status == P9_LOCK_BLOCKED && !IS_SETLKW(cmd))
193 break;
194 if (schedule_timeout_interruptible(v9ses->session_lock_timeout)
195 != 0)
196 break;
197 /*
198 * p9_client_lock_dotl overwrites flock.client_id with the
199 * server message, free and reuse the client name
200 */
201 if (flock.client_id != fid->clnt->name) {
202 kfree(flock.client_id);
203 flock.client_id = fid->clnt->name;
204 }
205 }
206
207 /* map 9p status to VFS status */
208 switch (status) {
209 case P9_LOCK_SUCCESS:
210 res = 0;
211 break;
212 case P9_LOCK_BLOCKED:
213 res = -EAGAIN;
214 break;
215 default:
216 WARN_ONCE(1, "unknown lock status code: %d\n", status);
217 fallthrough;
218 case P9_LOCK_ERROR:
219 case P9_LOCK_GRACE:
220 res = -ENOLCK;
221 break;
222 }
223
224out_unlock:
225 /*
226 * incase server returned error for lock request, revert
227 * it locally
228 */
229 if (res < 0 && fl->fl_type != F_UNLCK) {
230 fl_type = fl->fl_type;
231 fl->fl_type = F_UNLCK;
232 /* Even if this fails we want to return the remote error */
233 locks_lock_file_wait(filp, fl);
234 fl->fl_type = fl_type;
235 }
236 if (flock.client_id != fid->clnt->name)
237 kfree(flock.client_id);
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 goto out;
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 }
293out:
294 if (glock.client_id != fid->clnt->name)
295 kfree(glock.client_id);
296 return res;
297}
298
299/**
300 * v9fs_file_lock_dotl - lock a file (or directory)
301 * @filp: file to be locked
302 * @cmd: lock command
303 * @fl: file lock structure
304 *
305 */
306
307static int v9fs_file_lock_dotl(struct file *filp, int cmd, struct file_lock *fl)
308{
309 struct inode *inode = file_inode(filp);
310 int ret = -ENOLCK;
311
312 p9_debug(P9_DEBUG_VFS, "filp: %p cmd:%d lock: %p name: %pD\n",
313 filp, cmd, fl, filp);
314
315 /* No mandatory locks */
316 if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
317 goto out_err;
318
319 if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
320 filemap_write_and_wait(inode->i_mapping);
321 invalidate_mapping_pages(&inode->i_data, 0, -1);
322 }
323
324 if (IS_SETLK(cmd) || IS_SETLKW(cmd))
325 ret = v9fs_file_do_lock(filp, cmd, fl);
326 else if (IS_GETLK(cmd))
327 ret = v9fs_file_getlock(filp, fl);
328 else
329 ret = -EINVAL;
330out_err:
331 return ret;
332}
333
334/**
335 * v9fs_file_flock_dotl - lock a file
336 * @filp: file to be locked
337 * @cmd: lock command
338 * @fl: file lock structure
339 *
340 */
341
342static int v9fs_file_flock_dotl(struct file *filp, int cmd,
343 struct file_lock *fl)
344{
345 struct inode *inode = file_inode(filp);
346 int ret = -ENOLCK;
347
348 p9_debug(P9_DEBUG_VFS, "filp: %p cmd:%d lock: %p name: %pD\n",
349 filp, cmd, fl, filp);
350
351 /* No mandatory locks */
352 if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
353 goto out_err;
354
355 if (!(fl->fl_flags & FL_FLOCK))
356 goto out_err;
357
358 if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
359 filemap_write_and_wait(inode->i_mapping);
360 invalidate_mapping_pages(&inode->i_data, 0, -1);
361 }
362 /* Convert flock to posix lock */
363 fl->fl_flags |= FL_POSIX;
364 fl->fl_flags ^= FL_FLOCK;
365
366 if (IS_SETLK(cmd) | IS_SETLKW(cmd))
367 ret = v9fs_file_do_lock(filp, cmd, fl);
368 else
369 ret = -EINVAL;
370out_err:
371 return ret;
372}
373
374/**
375 * v9fs_file_read - read from a file
376 * @filp: file pointer to read
377 * @udata: user data buffer to read data into
378 * @count: size of buffer
379 * @offset: offset at which to read data
380 *
381 */
382
383static ssize_t
384v9fs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
385{
386 struct p9_fid *fid = iocb->ki_filp->private_data;
387 int ret, err = 0;
388
389 p9_debug(P9_DEBUG_VFS, "count %zu offset %lld\n",
390 iov_iter_count(to), iocb->ki_pos);
391
392 if (iocb->ki_filp->f_flags & O_NONBLOCK)
393 ret = p9_client_read_once(fid, iocb->ki_pos, to, &err);
394 else
395 ret = p9_client_read(fid, iocb->ki_pos, to, &err);
396 if (!ret)
397 return err;
398
399 iocb->ki_pos += ret;
400 return ret;
401}
402
403/**
404 * v9fs_file_write - write to a file
405 * @filp: file pointer to write
406 * @data: data buffer to write data from
407 * @count: size of buffer
408 * @offset: offset at which to write data
409 *
410 */
411static ssize_t
412v9fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
413{
414 struct file *file = iocb->ki_filp;
415 ssize_t retval;
416 loff_t origin;
417 int err = 0;
418
419 retval = generic_write_checks(iocb, from);
420 if (retval <= 0)
421 return retval;
422
423 origin = iocb->ki_pos;
424 retval = p9_client_write(file->private_data, iocb->ki_pos, from, &err);
425 if (retval > 0) {
426 struct inode *inode = file_inode(file);
427 loff_t i_size;
428 unsigned long pg_start, pg_end;
429 pg_start = origin >> PAGE_SHIFT;
430 pg_end = (origin + retval - 1) >> PAGE_SHIFT;
431 if (inode->i_mapping && inode->i_mapping->nrpages)
432 invalidate_inode_pages2_range(inode->i_mapping,
433 pg_start, pg_end);
434 iocb->ki_pos += retval;
435 i_size = i_size_read(inode);
436 if (iocb->ki_pos > i_size) {
437 inode_add_bytes(inode, iocb->ki_pos - i_size);
438 /*
439 * Need to serialize against i_size_write() in
440 * v9fs_stat2inode()
441 */
442 v9fs_i_size_write(inode, iocb->ki_pos);
443 }
444 return retval;
445 }
446 return err;
447}
448
449static int v9fs_file_fsync(struct file *filp, loff_t start, loff_t end,
450 int datasync)
451{
452 struct p9_fid *fid;
453 struct inode *inode = filp->f_mapping->host;
454 struct p9_wstat wstat;
455 int retval;
456
457 retval = file_write_and_wait_range(filp, start, end);
458 if (retval)
459 return retval;
460
461 inode_lock(inode);
462 p9_debug(P9_DEBUG_VFS, "filp %p datasync %x\n", filp, datasync);
463
464 fid = filp->private_data;
465 v9fs_blank_wstat(&wstat);
466
467 retval = p9_client_wstat(fid, &wstat);
468 inode_unlock(inode);
469
470 return retval;
471}
472
473int v9fs_file_fsync_dotl(struct file *filp, loff_t start, loff_t end,
474 int datasync)
475{
476 struct p9_fid *fid;
477 struct inode *inode = filp->f_mapping->host;
478 int retval;
479
480 retval = file_write_and_wait_range(filp, start, end);
481 if (retval)
482 return retval;
483
484 inode_lock(inode);
485 p9_debug(P9_DEBUG_VFS, "filp %p datasync %x\n", filp, datasync);
486
487 fid = filp->private_data;
488
489 retval = p9_client_fsync(fid, datasync);
490 inode_unlock(inode);
491
492 return retval;
493}
494
495static int
496v9fs_file_mmap(struct file *filp, struct vm_area_struct *vma)
497{
498 int retval;
499
500
501 retval = generic_file_mmap(filp, vma);
502 if (!retval)
503 vma->vm_ops = &v9fs_file_vm_ops;
504
505 return retval;
506}
507
508static int
509v9fs_mmap_file_mmap(struct file *filp, struct vm_area_struct *vma)
510{
511 int retval;
512 struct inode *inode;
513 struct v9fs_inode *v9inode;
514 struct p9_fid *fid;
515
516 inode = file_inode(filp);
517 v9inode = V9FS_I(inode);
518 mutex_lock(&v9inode->v_mutex);
519 if (!v9inode->writeback_fid &&
520 (vma->vm_flags & VM_SHARED) &&
521 (vma->vm_flags & VM_WRITE)) {
522 /*
523 * clone a fid and add it to writeback_fid
524 * we do it during mmap instead of
525 * page dirty time via write_begin/page_mkwrite
526 * because we want write after unlink usecase
527 * to work.
528 */
529 fid = v9fs_writeback_fid(file_dentry(filp));
530 if (IS_ERR(fid)) {
531 retval = PTR_ERR(fid);
532 mutex_unlock(&v9inode->v_mutex);
533 return retval;
534 }
535 v9inode->writeback_fid = (void *) fid;
536 }
537 mutex_unlock(&v9inode->v_mutex);
538
539 retval = generic_file_mmap(filp, vma);
540 if (!retval)
541 vma->vm_ops = &v9fs_mmap_file_vm_ops;
542
543 return retval;
544}
545
546static vm_fault_t
547v9fs_vm_page_mkwrite(struct vm_fault *vmf)
548{
549 struct v9fs_inode *v9inode;
550 struct page *page = vmf->page;
551 struct file *filp = vmf->vma->vm_file;
552 struct inode *inode = file_inode(filp);
553
554
555 p9_debug(P9_DEBUG_VFS, "page %p fid %lx\n",
556 page, (unsigned long)filp->private_data);
557
558 /* Update file times before taking page lock */
559 file_update_time(filp);
560
561 v9inode = V9FS_I(inode);
562 /* make sure the cache has finished storing the page */
563 v9fs_fscache_wait_on_page_write(inode, page);
564 BUG_ON(!v9inode->writeback_fid);
565 lock_page(page);
566 if (page->mapping != inode->i_mapping)
567 goto out_unlock;
568 wait_for_stable_page(page);
569
570 return VM_FAULT_LOCKED;
571out_unlock:
572 unlock_page(page);
573 return VM_FAULT_NOPAGE;
574}
575
576/**
577 * v9fs_mmap_file_read - read from a file
578 * @filp: file pointer to read
579 * @data: user data buffer to read data into
580 * @count: size of buffer
581 * @offset: offset at which to read data
582 *
583 */
584static ssize_t
585v9fs_mmap_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
586{
587 /* TODO: Check if there are dirty pages */
588 return v9fs_file_read_iter(iocb, to);
589}
590
591/**
592 * v9fs_mmap_file_write - write to a file
593 * @filp: file pointer to write
594 * @data: data buffer to write data from
595 * @count: size of buffer
596 * @offset: offset at which to write data
597 *
598 */
599static ssize_t
600v9fs_mmap_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
601{
602 /*
603 * TODO: invalidate mmaps on filp's inode between
604 * offset and offset+count
605 */
606 return v9fs_file_write_iter(iocb, from);
607}
608
609static void v9fs_mmap_vm_close(struct vm_area_struct *vma)
610{
611 struct inode *inode;
612
613 struct writeback_control wbc = {
614 .nr_to_write = LONG_MAX,
615 .sync_mode = WB_SYNC_ALL,
616 .range_start = (loff_t)vma->vm_pgoff * PAGE_SIZE,
617 /* absolute end, byte at end included */
618 .range_end = (loff_t)vma->vm_pgoff * PAGE_SIZE +
619 (vma->vm_end - vma->vm_start - 1),
620 };
621
622 if (!(vma->vm_flags & VM_SHARED))
623 return;
624
625 p9_debug(P9_DEBUG_VFS, "9p VMA close, %p, flushing", vma);
626
627 inode = file_inode(vma->vm_file);
628
629 if (!mapping_can_writeback(inode->i_mapping))
630 wbc.nr_to_write = 0;
631
632 might_sleep();
633 sync_inode(inode, &wbc);
634}
635
636
637static const struct vm_operations_struct v9fs_file_vm_ops = {
638 .fault = filemap_fault,
639 .map_pages = filemap_map_pages,
640 .page_mkwrite = v9fs_vm_page_mkwrite,
641};
642
643static const struct vm_operations_struct v9fs_mmap_file_vm_ops = {
644 .close = v9fs_mmap_vm_close,
645 .fault = filemap_fault,
646 .map_pages = filemap_map_pages,
647 .page_mkwrite = v9fs_vm_page_mkwrite,
648};
649
650
651const struct file_operations v9fs_cached_file_operations = {
652 .llseek = generic_file_llseek,
653 .read_iter = generic_file_read_iter,
654 .write_iter = generic_file_write_iter,
655 .open = v9fs_file_open,
656 .release = v9fs_dir_release,
657 .lock = v9fs_file_lock,
658 .mmap = v9fs_file_mmap,
659 .splice_read = generic_file_splice_read,
660 .splice_write = iter_file_splice_write,
661 .fsync = v9fs_file_fsync,
662};
663
664const struct file_operations v9fs_cached_file_operations_dotl = {
665 .llseek = generic_file_llseek,
666 .read_iter = generic_file_read_iter,
667 .write_iter = generic_file_write_iter,
668 .open = v9fs_file_open,
669 .release = v9fs_dir_release,
670 .lock = v9fs_file_lock_dotl,
671 .flock = v9fs_file_flock_dotl,
672 .mmap = v9fs_file_mmap,
673 .splice_read = generic_file_splice_read,
674 .splice_write = iter_file_splice_write,
675 .fsync = v9fs_file_fsync_dotl,
676};
677
678const struct file_operations v9fs_file_operations = {
679 .llseek = generic_file_llseek,
680 .read_iter = v9fs_file_read_iter,
681 .write_iter = v9fs_file_write_iter,
682 .open = v9fs_file_open,
683 .release = v9fs_dir_release,
684 .lock = v9fs_file_lock,
685 .mmap = generic_file_readonly_mmap,
686 .splice_read = generic_file_splice_read,
687 .splice_write = iter_file_splice_write,
688 .fsync = v9fs_file_fsync,
689};
690
691const struct file_operations v9fs_file_operations_dotl = {
692 .llseek = generic_file_llseek,
693 .read_iter = v9fs_file_read_iter,
694 .write_iter = v9fs_file_write_iter,
695 .open = v9fs_file_open,
696 .release = v9fs_dir_release,
697 .lock = v9fs_file_lock_dotl,
698 .flock = v9fs_file_flock_dotl,
699 .mmap = generic_file_readonly_mmap,
700 .splice_read = generic_file_splice_read,
701 .splice_write = iter_file_splice_write,
702 .fsync = v9fs_file_fsync_dotl,
703};
704
705const struct file_operations v9fs_mmap_file_operations = {
706 .llseek = generic_file_llseek,
707 .read_iter = v9fs_mmap_file_read_iter,
708 .write_iter = v9fs_mmap_file_write_iter,
709 .open = v9fs_file_open,
710 .release = v9fs_dir_release,
711 .lock = v9fs_file_lock,
712 .mmap = v9fs_mmap_file_mmap,
713 .splice_read = generic_file_splice_read,
714 .splice_write = iter_file_splice_write,
715 .fsync = v9fs_file_fsync,
716};
717
718const struct file_operations v9fs_mmap_file_operations_dotl = {
719 .llseek = generic_file_llseek,
720 .read_iter = v9fs_mmap_file_read_iter,
721 .write_iter = v9fs_mmap_file_write_iter,
722 .open = v9fs_file_open,
723 .release = v9fs_dir_release,
724 .lock = v9fs_file_lock_dotl,
725 .flock = v9fs_file_flock_dotl,
726 .mmap = v9fs_mmap_file_mmap,
727 .splice_read = generic_file_splice_read,
728 .splice_write = iter_file_splice_write,
729 .fsync = v9fs_file_fsync_dotl,
730};