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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/*
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 <net/9p/9p.h>
40#include <net/9p/client.h>
41
42#include "v9fs.h"
43#include "v9fs_vfs.h"
44#include "fid.h"
45#include "cache.h"
46
47static const struct vm_operations_struct v9fs_file_vm_ops;
48
49/**
50 * v9fs_file_open - open a file (or directory)
51 * @inode: inode to be opened
52 * @file: file being opened
53 *
54 */
55
56int v9fs_file_open(struct inode *inode, struct file *file)
57{
58 int err;
59 struct v9fs_inode *v9inode;
60 struct v9fs_session_info *v9ses;
61 struct p9_fid *fid;
62 int omode;
63
64 p9_debug(P9_DEBUG_VFS, "inode: %p file: %p\n", inode, file);
65 v9inode = V9FS_I(inode);
66 v9ses = v9fs_inode2v9ses(inode);
67 if (v9fs_proto_dotl(v9ses))
68 omode = v9fs_open_to_dotl_flags(file->f_flags);
69 else
70 omode = v9fs_uflags2omode(file->f_flags,
71 v9fs_proto_dotu(v9ses));
72 fid = file->private_data;
73 if (!fid) {
74 fid = v9fs_fid_clone(file->f_path.dentry);
75 if (IS_ERR(fid))
76 return PTR_ERR(fid);
77
78 err = p9_client_open(fid, omode);
79 if (err < 0) {
80 p9_client_clunk(fid);
81 return err;
82 }
83 if (file->f_flags & O_TRUNC) {
84 i_size_write(inode, 0);
85 inode->i_blocks = 0;
86 }
87 if ((file->f_flags & O_APPEND) &&
88 (!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)))
89 generic_file_llseek(file, 0, SEEK_END);
90 }
91
92 file->private_data = fid;
93 mutex_lock(&v9inode->v_mutex);
94 if (v9ses->cache && !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#ifdef CONFIG_9P_FSCACHE
113 if (v9ses->cache)
114 v9fs_cache_inode_set_cookie(inode, file);
115#endif
116 return 0;
117out_error:
118 p9_client_clunk(file->private_data);
119 file->private_data = NULL;
120 return err;
121}
122
123/**
124 * v9fs_file_lock - lock a file (or directory)
125 * @filp: file to be locked
126 * @cmd: lock command
127 * @fl: file lock structure
128 *
129 * Bugs: this looks like a local only lock, we should extend into 9P
130 * by using open exclusive
131 */
132
133static int v9fs_file_lock(struct file *filp, int cmd, struct file_lock *fl)
134{
135 int res = 0;
136 struct inode *inode = filp->f_path.dentry->d_inode;
137
138 p9_debug(P9_DEBUG_VFS, "filp: %p lock: %p\n", filp, fl);
139
140 /* No mandatory locks */
141 if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
142 return -ENOLCK;
143
144 if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
145 filemap_write_and_wait(inode->i_mapping);
146 invalidate_mapping_pages(&inode->i_data, 0, -1);
147 }
148
149 return res;
150}
151
152static int v9fs_file_do_lock(struct file *filp, int cmd, struct file_lock *fl)
153{
154 struct p9_flock flock;
155 struct p9_fid *fid;
156 uint8_t status;
157 int res = 0;
158 unsigned char fl_type;
159
160 fid = filp->private_data;
161 BUG_ON(fid == NULL);
162
163 if ((fl->fl_flags & FL_POSIX) != FL_POSIX)
164 BUG();
165
166 res = posix_lock_file_wait(filp, fl);
167 if (res < 0)
168 goto out;
169
170 /* convert posix lock to p9 tlock args */
171 memset(&flock, 0, sizeof(flock));
172 /* map the lock type */
173 switch (fl->fl_type) {
174 case F_RDLCK:
175 flock.type = P9_LOCK_TYPE_RDLCK;
176 break;
177 case F_WRLCK:
178 flock.type = P9_LOCK_TYPE_WRLCK;
179 break;
180 case F_UNLCK:
181 flock.type = P9_LOCK_TYPE_UNLCK;
182 break;
183 }
184 flock.start = fl->fl_start;
185 if (fl->fl_end == OFFSET_MAX)
186 flock.length = 0;
187 else
188 flock.length = fl->fl_end - fl->fl_start + 1;
189 flock.proc_id = fl->fl_pid;
190 flock.client_id = utsname()->nodename;
191 if (IS_SETLKW(cmd))
192 flock.flags = P9_LOCK_FLAGS_BLOCK;
193
194 /*
195 * if its a blocked request and we get P9_LOCK_BLOCKED as the status
196 * for lock request, keep on trying
197 */
198 for (;;) {
199 res = p9_client_lock_dotl(fid, &flock, &status);
200 if (res < 0)
201 break;
202
203 if (status != P9_LOCK_BLOCKED)
204 break;
205 if (status == P9_LOCK_BLOCKED && !IS_SETLKW(cmd))
206 break;
207 if (schedule_timeout_interruptible(P9_LOCK_TIMEOUT) != 0)
208 break;
209 }
210
211 /* map 9p status to VFS status */
212 switch (status) {
213 case P9_LOCK_SUCCESS:
214 res = 0;
215 break;
216 case P9_LOCK_BLOCKED:
217 res = -EAGAIN;
218 break;
219 case P9_LOCK_ERROR:
220 case P9_LOCK_GRACE:
221 res = -ENOLCK;
222 break;
223 default:
224 BUG();
225 }
226
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 res = posix_lock_file_wait(filp, fl);
235 fl->fl_type = fl_type;
236 }
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 = utsname()->nodename;
268
269 res = p9_client_getlock_dotl(fid, &glock);
270 if (res < 0)
271 return res;
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 }
292 return res;
293}
294
295/**
296 * v9fs_file_lock_dotl - lock a file (or directory)
297 * @filp: file to be locked
298 * @cmd: lock command
299 * @fl: file lock structure
300 *
301 */
302
303static int v9fs_file_lock_dotl(struct file *filp, int cmd, struct file_lock *fl)
304{
305 struct inode *inode = filp->f_path.dentry->d_inode;
306 int ret = -ENOLCK;
307
308 p9_debug(P9_DEBUG_VFS, "filp: %p cmd:%d lock: %p name: %s\n",
309 filp, cmd, fl, filp->f_path.dentry->d_name.name);
310
311 /* No mandatory locks */
312 if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
313 goto out_err;
314
315 if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
316 filemap_write_and_wait(inode->i_mapping);
317 invalidate_mapping_pages(&inode->i_data, 0, -1);
318 }
319
320 if (IS_SETLK(cmd) || IS_SETLKW(cmd))
321 ret = v9fs_file_do_lock(filp, cmd, fl);
322 else if (IS_GETLK(cmd))
323 ret = v9fs_file_getlock(filp, fl);
324 else
325 ret = -EINVAL;
326out_err:
327 return ret;
328}
329
330/**
331 * v9fs_file_flock_dotl - lock a file
332 * @filp: file to be locked
333 * @cmd: lock command
334 * @fl: file lock structure
335 *
336 */
337
338static int v9fs_file_flock_dotl(struct file *filp, int cmd,
339 struct file_lock *fl)
340{
341 struct inode *inode = filp->f_path.dentry->d_inode;
342 int ret = -ENOLCK;
343
344 p9_debug(P9_DEBUG_VFS, "filp: %p cmd:%d lock: %p name: %s\n",
345 filp, cmd, fl, filp->f_path.dentry->d_name.name);
346
347 /* No mandatory locks */
348 if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
349 goto out_err;
350
351 if (!(fl->fl_flags & FL_FLOCK))
352 goto out_err;
353
354 if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
355 filemap_write_and_wait(inode->i_mapping);
356 invalidate_mapping_pages(&inode->i_data, 0, -1);
357 }
358 /* Convert flock to posix lock */
359 fl->fl_owner = (fl_owner_t)filp;
360 fl->fl_start = 0;
361 fl->fl_end = OFFSET_MAX;
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_fid_readn - read from a fid
375 * @fid: fid to read
376 * @data: data buffer to read data into
377 * @udata: user data buffer to read data into
378 * @count: size of buffer
379 * @offset: offset at which to read data
380 *
381 */
382ssize_t
383v9fs_fid_readn(struct p9_fid *fid, char *data, char __user *udata, u32 count,
384 u64 offset)
385{
386 int n, total, size;
387
388 p9_debug(P9_DEBUG_VFS, "fid %d offset %llu count %d\n",
389 fid->fid, (long long unsigned)offset, count);
390 n = 0;
391 total = 0;
392 size = fid->iounit ? fid->iounit : fid->clnt->msize - P9_IOHDRSZ;
393 do {
394 n = p9_client_read(fid, data, udata, offset, count);
395 if (n <= 0)
396 break;
397
398 if (data)
399 data += n;
400 if (udata)
401 udata += n;
402
403 offset += n;
404 count -= n;
405 total += n;
406 } while (count > 0 && n == size);
407
408 if (n < 0)
409 total = n;
410
411 return total;
412}
413
414/**
415 * v9fs_file_readn - read from a file
416 * @filp: file pointer to read
417 * @data: data buffer to read data into
418 * @udata: user data buffer to read data into
419 * @count: size of buffer
420 * @offset: offset at which to read data
421 *
422 */
423ssize_t
424v9fs_file_readn(struct file *filp, char *data, char __user *udata, u32 count,
425 u64 offset)
426{
427 return v9fs_fid_readn(filp->private_data, data, udata, count, offset);
428}
429
430/**
431 * v9fs_file_read - read from a file
432 * @filp: file pointer to read
433 * @udata: user data buffer to read data into
434 * @count: size of buffer
435 * @offset: offset at which to read data
436 *
437 */
438
439static ssize_t
440v9fs_file_read(struct file *filp, char __user *udata, size_t count,
441 loff_t * offset)
442{
443 int ret;
444 struct p9_fid *fid;
445 size_t size;
446
447 p9_debug(P9_DEBUG_VFS, "count %zu offset %lld\n", count, *offset);
448 fid = filp->private_data;
449
450 size = fid->iounit ? fid->iounit : fid->clnt->msize - P9_IOHDRSZ;
451 if (count > size)
452 ret = v9fs_file_readn(filp, NULL, udata, count, *offset);
453 else
454 ret = p9_client_read(fid, NULL, udata, *offset, count);
455
456 if (ret > 0)
457 *offset += ret;
458
459 return ret;
460}
461
462ssize_t
463v9fs_file_write_internal(struct inode *inode, struct p9_fid *fid,
464 const char __user *data, size_t count,
465 loff_t *offset, int invalidate)
466{
467 int n;
468 loff_t i_size;
469 size_t total = 0;
470 struct p9_client *clnt;
471 loff_t origin = *offset;
472 unsigned long pg_start, pg_end;
473
474 p9_debug(P9_DEBUG_VFS, "data %p count %d offset %x\n",
475 data, (int)count, (int)*offset);
476
477 clnt = fid->clnt;
478 do {
479 n = p9_client_write(fid, NULL, data+total, origin+total, count);
480 if (n <= 0)
481 break;
482 count -= n;
483 total += n;
484 } while (count > 0);
485
486 if (invalidate && (total > 0)) {
487 pg_start = origin >> PAGE_CACHE_SHIFT;
488 pg_end = (origin + total - 1) >> PAGE_CACHE_SHIFT;
489 if (inode->i_mapping && inode->i_mapping->nrpages)
490 invalidate_inode_pages2_range(inode->i_mapping,
491 pg_start, pg_end);
492 *offset += total;
493 i_size = i_size_read(inode);
494 if (*offset > i_size) {
495 inode_add_bytes(inode, *offset - i_size);
496 i_size_write(inode, *offset);
497 }
498 }
499 if (n < 0)
500 return n;
501
502 return total;
503}
504
505/**
506 * v9fs_file_write - write to a file
507 * @filp: file pointer to write
508 * @data: data buffer to write data from
509 * @count: size of buffer
510 * @offset: offset at which to write data
511 *
512 */
513static ssize_t
514v9fs_file_write(struct file *filp, const char __user * data,
515 size_t count, loff_t *offset)
516{
517 ssize_t retval = 0;
518 loff_t origin = *offset;
519
520
521 retval = generic_write_checks(filp, &origin, &count, 0);
522 if (retval)
523 goto out;
524
525 retval = -EINVAL;
526 if ((ssize_t) count < 0)
527 goto out;
528 retval = 0;
529 if (!count)
530 goto out;
531
532 retval = v9fs_file_write_internal(filp->f_path.dentry->d_inode,
533 filp->private_data,
534 data, count, &origin, 1);
535 /* update offset on successful write */
536 if (retval > 0)
537 *offset = origin;
538out:
539 return retval;
540}
541
542
543static int v9fs_file_fsync(struct file *filp, loff_t start, loff_t end,
544 int datasync)
545{
546 struct p9_fid *fid;
547 struct inode *inode = filp->f_mapping->host;
548 struct p9_wstat wstat;
549 int retval;
550
551 retval = filemap_write_and_wait_range(inode->i_mapping, start, end);
552 if (retval)
553 return retval;
554
555 mutex_lock(&inode->i_mutex);
556 p9_debug(P9_DEBUG_VFS, "filp %p datasync %x\n", filp, datasync);
557
558 fid = filp->private_data;
559 v9fs_blank_wstat(&wstat);
560
561 retval = p9_client_wstat(fid, &wstat);
562 mutex_unlock(&inode->i_mutex);
563
564 return retval;
565}
566
567int v9fs_file_fsync_dotl(struct file *filp, loff_t start, loff_t end,
568 int datasync)
569{
570 struct p9_fid *fid;
571 struct inode *inode = filp->f_mapping->host;
572 int retval;
573
574 retval = filemap_write_and_wait_range(inode->i_mapping, start, end);
575 if (retval)
576 return retval;
577
578 mutex_lock(&inode->i_mutex);
579 p9_debug(P9_DEBUG_VFS, "filp %p datasync %x\n", filp, datasync);
580
581 fid = filp->private_data;
582
583 retval = p9_client_fsync(fid, datasync);
584 mutex_unlock(&inode->i_mutex);
585
586 return retval;
587}
588
589static int
590v9fs_file_mmap(struct file *file, struct vm_area_struct *vma)
591{
592 int retval;
593
594 retval = generic_file_mmap(file, vma);
595 if (!retval)
596 vma->vm_ops = &v9fs_file_vm_ops;
597
598 return retval;
599}
600
601static int
602v9fs_vm_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
603{
604 struct v9fs_inode *v9inode;
605 struct page *page = vmf->page;
606 struct file *filp = vma->vm_file;
607 struct inode *inode = filp->f_path.dentry->d_inode;
608
609
610 p9_debug(P9_DEBUG_VFS, "page %p fid %lx\n",
611 page, (unsigned long)filp->private_data);
612
613 v9inode = V9FS_I(inode);
614 /* make sure the cache has finished storing the page */
615 v9fs_fscache_wait_on_page_write(inode, page);
616 BUG_ON(!v9inode->writeback_fid);
617 lock_page(page);
618 if (page->mapping != inode->i_mapping)
619 goto out_unlock;
620
621 return VM_FAULT_LOCKED;
622out_unlock:
623 unlock_page(page);
624 return VM_FAULT_NOPAGE;
625}
626
627static ssize_t
628v9fs_direct_read(struct file *filp, char __user *udata, size_t count,
629 loff_t *offsetp)
630{
631 loff_t size, offset;
632 struct inode *inode;
633 struct address_space *mapping;
634
635 offset = *offsetp;
636 mapping = filp->f_mapping;
637 inode = mapping->host;
638 if (!count)
639 return 0;
640 size = i_size_read(inode);
641 if (offset < size)
642 filemap_write_and_wait_range(mapping, offset,
643 offset + count - 1);
644
645 return v9fs_file_read(filp, udata, count, offsetp);
646}
647
648/**
649 * v9fs_cached_file_read - read from a file
650 * @filp: file pointer to read
651 * @udata: user data buffer to read data into
652 * @count: size of buffer
653 * @offset: offset at which to read data
654 *
655 */
656static ssize_t
657v9fs_cached_file_read(struct file *filp, char __user *data, size_t count,
658 loff_t *offset)
659{
660 if (filp->f_flags & O_DIRECT)
661 return v9fs_direct_read(filp, data, count, offset);
662 return do_sync_read(filp, data, count, offset);
663}
664
665static ssize_t
666v9fs_direct_write(struct file *filp, const char __user * data,
667 size_t count, loff_t *offsetp)
668{
669 loff_t offset;
670 ssize_t retval;
671 struct inode *inode;
672 struct address_space *mapping;
673
674 offset = *offsetp;
675 mapping = filp->f_mapping;
676 inode = mapping->host;
677 if (!count)
678 return 0;
679
680 mutex_lock(&inode->i_mutex);
681 retval = filemap_write_and_wait_range(mapping, offset,
682 offset + count - 1);
683 if (retval)
684 goto err_out;
685 /*
686 * After a write we want buffered reads to be sure to go to disk to get
687 * the new data. We invalidate clean cached page from the region we're
688 * about to write. We do this *before* the write so that if we fail
689 * here we fall back to buffered write
690 */
691 if (mapping->nrpages) {
692 pgoff_t pg_start = offset >> PAGE_CACHE_SHIFT;
693 pgoff_t pg_end = (offset + count - 1) >> PAGE_CACHE_SHIFT;
694
695 retval = invalidate_inode_pages2_range(mapping,
696 pg_start, pg_end);
697 /*
698 * If a page can not be invalidated, fall back
699 * to buffered write.
700 */
701 if (retval) {
702 if (retval == -EBUSY)
703 goto buff_write;
704 goto err_out;
705 }
706 }
707 retval = v9fs_file_write(filp, data, count, offsetp);
708err_out:
709 mutex_unlock(&inode->i_mutex);
710 return retval;
711
712buff_write:
713 mutex_unlock(&inode->i_mutex);
714 return do_sync_write(filp, data, count, offsetp);
715}
716
717/**
718 * v9fs_cached_file_write - write to a file
719 * @filp: file pointer to write
720 * @data: data buffer to write data from
721 * @count: size of buffer
722 * @offset: offset at which to write data
723 *
724 */
725static ssize_t
726v9fs_cached_file_write(struct file *filp, const char __user * data,
727 size_t count, loff_t *offset)
728{
729
730 if (filp->f_flags & O_DIRECT)
731 return v9fs_direct_write(filp, data, count, offset);
732 return do_sync_write(filp, data, count, offset);
733}
734
735static const struct vm_operations_struct v9fs_file_vm_ops = {
736 .fault = filemap_fault,
737 .page_mkwrite = v9fs_vm_page_mkwrite,
738};
739
740
741const struct file_operations v9fs_cached_file_operations = {
742 .llseek = generic_file_llseek,
743 .read = v9fs_cached_file_read,
744 .write = v9fs_cached_file_write,
745 .aio_read = generic_file_aio_read,
746 .aio_write = generic_file_aio_write,
747 .open = v9fs_file_open,
748 .release = v9fs_dir_release,
749 .lock = v9fs_file_lock,
750 .mmap = v9fs_file_mmap,
751 .fsync = v9fs_file_fsync,
752};
753
754const struct file_operations v9fs_cached_file_operations_dotl = {
755 .llseek = generic_file_llseek,
756 .read = v9fs_cached_file_read,
757 .write = v9fs_cached_file_write,
758 .aio_read = generic_file_aio_read,
759 .aio_write = generic_file_aio_write,
760 .open = v9fs_file_open,
761 .release = v9fs_dir_release,
762 .lock = v9fs_file_lock_dotl,
763 .flock = v9fs_file_flock_dotl,
764 .mmap = v9fs_file_mmap,
765 .fsync = v9fs_file_fsync_dotl,
766};
767
768const struct file_operations v9fs_file_operations = {
769 .llseek = generic_file_llseek,
770 .read = v9fs_file_read,
771 .write = v9fs_file_write,
772 .open = v9fs_file_open,
773 .release = v9fs_dir_release,
774 .lock = v9fs_file_lock,
775 .mmap = generic_file_readonly_mmap,
776 .fsync = v9fs_file_fsync,
777};
778
779const struct file_operations v9fs_file_operations_dotl = {
780 .llseek = generic_file_llseek,
781 .read = v9fs_file_read,
782 .write = v9fs_file_write,
783 .open = v9fs_file_open,
784 .release = v9fs_dir_release,
785 .lock = v9fs_file_lock_dotl,
786 .flock = v9fs_file_flock_dotl,
787 .mmap = generic_file_readonly_mmap,
788 .fsync = v9fs_file_fsync_dotl,
789};