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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * This file contians vfs file ops for 9P2000.
4 *
5 * Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
6 * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
7 */
8
9#include <linux/module.h>
10#include <linux/errno.h>
11#include <linux/fs.h>
12#include <linux/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->c.flc_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 struct v9fs_session_info *v9ses;
125
126 fid = filp->private_data;
127 BUG_ON(fid == NULL);
128
129 BUG_ON((fl->c.flc_flags & FL_POSIX) != FL_POSIX);
130
131 res = locks_lock_file_wait(filp, fl);
132 if (res < 0)
133 goto out;
134
135 /* convert posix lock to p9 tlock args */
136 memset(&flock, 0, sizeof(flock));
137 /* map the lock type */
138 switch (fl->c.flc_type) {
139 case F_RDLCK:
140 flock.type = P9_LOCK_TYPE_RDLCK;
141 break;
142 case F_WRLCK:
143 flock.type = P9_LOCK_TYPE_WRLCK;
144 break;
145 case F_UNLCK:
146 flock.type = P9_LOCK_TYPE_UNLCK;
147 break;
148 }
149 flock.start = fl->fl_start;
150 if (fl->fl_end == OFFSET_MAX)
151 flock.length = 0;
152 else
153 flock.length = fl->fl_end - fl->fl_start + 1;
154 flock.proc_id = fl->c.flc_pid;
155 flock.client_id = fid->clnt->name;
156 if (IS_SETLKW(cmd))
157 flock.flags = P9_LOCK_FLAGS_BLOCK;
158
159 v9ses = v9fs_inode2v9ses(file_inode(filp));
160
161 /*
162 * if its a blocked request and we get P9_LOCK_BLOCKED as the status
163 * for lock request, keep on trying
164 */
165 for (;;) {
166 res = p9_client_lock_dotl(fid, &flock, &status);
167 if (res < 0)
168 goto out_unlock;
169
170 if (status != P9_LOCK_BLOCKED)
171 break;
172 if (status == P9_LOCK_BLOCKED && !IS_SETLKW(cmd))
173 break;
174 if (schedule_timeout_interruptible(v9ses->session_lock_timeout)
175 != 0)
176 break;
177 /*
178 * p9_client_lock_dotl overwrites flock.client_id with the
179 * server message, free and reuse the client name
180 */
181 if (flock.client_id != fid->clnt->name) {
182 kfree(flock.client_id);
183 flock.client_id = fid->clnt->name;
184 }
185 }
186
187 /* map 9p status to VFS status */
188 switch (status) {
189 case P9_LOCK_SUCCESS:
190 res = 0;
191 break;
192 case P9_LOCK_BLOCKED:
193 res = -EAGAIN;
194 break;
195 default:
196 WARN_ONCE(1, "unknown lock status code: %d\n", status);
197 fallthrough;
198 case P9_LOCK_ERROR:
199 case P9_LOCK_GRACE:
200 res = -ENOLCK;
201 break;
202 }
203
204out_unlock:
205 /*
206 * incase server returned error for lock request, revert
207 * it locally
208 */
209 if (res < 0 && fl->c.flc_type != F_UNLCK) {
210 unsigned char type = fl->c.flc_type;
211
212 fl->c.flc_type = F_UNLCK;
213 /* Even if this fails we want to return the remote error */
214 locks_lock_file_wait(filp, fl);
215 fl->c.flc_type = 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->c.flc_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->c.flc_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->c.flc_type = F_RDLCK;
258 break;
259 case P9_LOCK_TYPE_WRLCK:
260 fl->c.flc_type = F_WRLCK;
261 break;
262 case P9_LOCK_TYPE_UNLCK:
263 fl->c.flc_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->c.flc_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->c.flc_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->c.flc_flags & FL_FLOCK))
328 goto out_err;
329
330 if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->c.flc_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->c.flc_flags |= FL_POSIX;
336 fl->c.flc_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 .setlease = simple_nosetlease,
524};
525
526const struct file_operations v9fs_file_operations_dotl = {
527 .llseek = generic_file_llseek,
528 .read_iter = v9fs_file_read_iter,
529 .write_iter = v9fs_file_write_iter,
530 .open = v9fs_file_open,
531 .release = v9fs_dir_release,
532 .lock = v9fs_file_lock_dotl,
533 .flock = v9fs_file_flock_dotl,
534 .mmap = v9fs_file_mmap,
535 .splice_read = v9fs_file_splice_read,
536 .splice_write = iter_file_splice_write,
537 .fsync = v9fs_file_fsync_dotl,
538 .setlease = simple_nosetlease,
539};
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};