Linux 4.9.243
[linux/fpc-iii.git] / fs / 9p / vfs_file.c
blob6be16c74e3e9e97b82028a3ca29a8438e9607aec
1 /*
2 * linux/fs/9p/vfs_file.c
4 * This file contians vfs file ops for 9P2000.
6 * Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
7 * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
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.
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.
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
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>
44 #include "v9fs.h"
45 #include "v9fs_vfs.h"
46 #include "fid.h"
47 #include "cache.h"
49 static const struct vm_operations_struct v9fs_file_vm_ops;
50 static const struct vm_operations_struct v9fs_mmap_file_vm_ops;
52 /**
53 * v9fs_file_open - open a file (or directory)
54 * @inode: inode to be opened
55 * @file: file being opened
59 int v9fs_file_open(struct inode *inode, struct file *file)
61 int err;
62 struct v9fs_inode *v9inode;
63 struct v9fs_session_info *v9ses;
64 struct p9_fid *fid;
65 int omode;
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_dentry(file));
78 if (IS_ERR(fid))
79 return PTR_ERR(fid);
81 err = p9_client_open(fid, omode);
82 if (err < 0) {
83 p9_client_clunk(fid);
84 return err;
86 if ((file->f_flags & O_APPEND) &&
87 (!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)))
88 generic_file_llseek(file, 0, SEEK_END);
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)) {
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.
103 fid = v9fs_writeback_fid(file_dentry(file));
104 if (IS_ERR(fid)) {
105 err = PTR_ERR(fid);
106 mutex_unlock(&v9inode->v_mutex);
107 goto out_error;
109 v9inode->writeback_fid = (void *) fid;
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;
115 out_error:
116 p9_client_clunk(file->private_data);
117 file->private_data = NULL;
118 return err;
122 * v9fs_file_lock - lock a file (or directory)
123 * @filp: file to be locked
124 * @cmd: lock command
125 * @fl: file lock structure
127 * Bugs: this looks like a local only lock, we should extend into 9P
128 * by using open exclusive
131 static int v9fs_file_lock(struct file *filp, int cmd, struct file_lock *fl)
133 int res = 0;
134 struct inode *inode = file_inode(filp);
136 p9_debug(P9_DEBUG_VFS, "filp: %p lock: %p\n", filp, fl);
138 /* No mandatory locks */
139 if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
140 return -ENOLCK;
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);
147 return res;
150 static int v9fs_file_do_lock(struct file *filp, int cmd, struct file_lock *fl)
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 struct v9fs_session_info *v9ses;
159 fid = filp->private_data;
160 BUG_ON(fid == NULL);
162 if ((fl->fl_flags & FL_POSIX) != FL_POSIX)
163 BUG();
165 res = locks_lock_file_wait(filp, fl);
166 if (res < 0)
167 goto out;
169 /* convert posix lock to p9 tlock args */
170 memset(&flock, 0, sizeof(flock));
171 /* map the lock type */
172 switch (fl->fl_type) {
173 case F_RDLCK:
174 flock.type = P9_LOCK_TYPE_RDLCK;
175 break;
176 case F_WRLCK:
177 flock.type = P9_LOCK_TYPE_WRLCK;
178 break;
179 case F_UNLCK:
180 flock.type = P9_LOCK_TYPE_UNLCK;
181 break;
183 flock.start = fl->fl_start;
184 if (fl->fl_end == OFFSET_MAX)
185 flock.length = 0;
186 else
187 flock.length = fl->fl_end - fl->fl_start + 1;
188 flock.proc_id = fl->fl_pid;
189 flock.client_id = fid->clnt->name;
190 if (IS_SETLKW(cmd))
191 flock.flags = P9_LOCK_FLAGS_BLOCK;
193 v9ses = v9fs_inode2v9ses(file_inode(filp));
196 * if its a blocked request and we get P9_LOCK_BLOCKED as the status
197 * for lock request, keep on trying
199 for (;;) {
200 res = p9_client_lock_dotl(fid, &flock, &status);
201 if (res < 0)
202 goto out_unlock;
204 if (status != P9_LOCK_BLOCKED)
205 break;
206 if (status == P9_LOCK_BLOCKED && !IS_SETLKW(cmd))
207 break;
208 if (schedule_timeout_interruptible(v9ses->session_lock_timeout)
209 != 0)
210 break;
212 * p9_client_lock_dotl overwrites flock.client_id with the
213 * server message, free and reuse the client name
215 if (flock.client_id != fid->clnt->name) {
216 kfree(flock.client_id);
217 flock.client_id = fid->clnt->name;
221 /* map 9p status to VFS status */
222 switch (status) {
223 case P9_LOCK_SUCCESS:
224 res = 0;
225 break;
226 case P9_LOCK_BLOCKED:
227 res = -EAGAIN;
228 break;
229 default:
230 WARN_ONCE(1, "unknown lock status code: %d\n", status);
231 /* fallthough */
232 case P9_LOCK_ERROR:
233 case P9_LOCK_GRACE:
234 res = -ENOLCK;
235 break;
238 out_unlock:
240 * incase server returned error for lock request, revert
241 * it locally
243 if (res < 0 && fl->fl_type != F_UNLCK) {
244 fl_type = fl->fl_type;
245 fl->fl_type = F_UNLCK;
246 /* Even if this fails we want to return the remote error */
247 locks_lock_file_wait(filp, fl);
248 fl->fl_type = fl_type;
250 if (flock.client_id != fid->clnt->name)
251 kfree(flock.client_id);
252 out:
253 return res;
256 static int v9fs_file_getlock(struct file *filp, struct file_lock *fl)
258 struct p9_getlock glock;
259 struct p9_fid *fid;
260 int res = 0;
262 fid = filp->private_data;
263 BUG_ON(fid == NULL);
265 posix_test_lock(filp, fl);
267 * if we have a conflicting lock locally, no need to validate
268 * with server
270 if (fl->fl_type != F_UNLCK)
271 return res;
273 /* convert posix lock to p9 tgetlock args */
274 memset(&glock, 0, sizeof(glock));
275 glock.type = P9_LOCK_TYPE_UNLCK;
276 glock.start = fl->fl_start;
277 if (fl->fl_end == OFFSET_MAX)
278 glock.length = 0;
279 else
280 glock.length = fl->fl_end - fl->fl_start + 1;
281 glock.proc_id = fl->fl_pid;
282 glock.client_id = fid->clnt->name;
284 res = p9_client_getlock_dotl(fid, &glock);
285 if (res < 0)
286 goto out;
287 /* map 9p lock type to os lock type */
288 switch (glock.type) {
289 case P9_LOCK_TYPE_RDLCK:
290 fl->fl_type = F_RDLCK;
291 break;
292 case P9_LOCK_TYPE_WRLCK:
293 fl->fl_type = F_WRLCK;
294 break;
295 case P9_LOCK_TYPE_UNLCK:
296 fl->fl_type = F_UNLCK;
297 break;
299 if (glock.type != P9_LOCK_TYPE_UNLCK) {
300 fl->fl_start = glock.start;
301 if (glock.length == 0)
302 fl->fl_end = OFFSET_MAX;
303 else
304 fl->fl_end = glock.start + glock.length - 1;
305 fl->fl_pid = glock.proc_id;
307 out:
308 if (glock.client_id != fid->clnt->name)
309 kfree(glock.client_id);
310 return res;
314 * v9fs_file_lock_dotl - lock a file (or directory)
315 * @filp: file to be locked
316 * @cmd: lock command
317 * @fl: file lock structure
321 static int v9fs_file_lock_dotl(struct file *filp, int cmd, struct file_lock *fl)
323 struct inode *inode = file_inode(filp);
324 int ret = -ENOLCK;
326 p9_debug(P9_DEBUG_VFS, "filp: %p cmd:%d lock: %p name: %pD\n",
327 filp, cmd, fl, filp);
329 /* No mandatory locks */
330 if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
331 goto out_err;
333 if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
334 filemap_write_and_wait(inode->i_mapping);
335 invalidate_mapping_pages(&inode->i_data, 0, -1);
338 if (IS_SETLK(cmd) || IS_SETLKW(cmd))
339 ret = v9fs_file_do_lock(filp, cmd, fl);
340 else if (IS_GETLK(cmd))
341 ret = v9fs_file_getlock(filp, fl);
342 else
343 ret = -EINVAL;
344 out_err:
345 return ret;
349 * v9fs_file_flock_dotl - lock a file
350 * @filp: file to be locked
351 * @cmd: lock command
352 * @fl: file lock structure
356 static int v9fs_file_flock_dotl(struct file *filp, int cmd,
357 struct file_lock *fl)
359 struct inode *inode = file_inode(filp);
360 int ret = -ENOLCK;
362 p9_debug(P9_DEBUG_VFS, "filp: %p cmd:%d lock: %p name: %pD\n",
363 filp, cmd, fl, filp);
365 /* No mandatory locks */
366 if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
367 goto out_err;
369 if (!(fl->fl_flags & FL_FLOCK))
370 goto out_err;
372 if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
373 filemap_write_and_wait(inode->i_mapping);
374 invalidate_mapping_pages(&inode->i_data, 0, -1);
376 /* Convert flock to posix lock */
377 fl->fl_flags |= FL_POSIX;
378 fl->fl_flags ^= FL_FLOCK;
380 if (IS_SETLK(cmd) | IS_SETLKW(cmd))
381 ret = v9fs_file_do_lock(filp, cmd, fl);
382 else
383 ret = -EINVAL;
384 out_err:
385 return ret;
389 * v9fs_file_read - read from a file
390 * @filp: file pointer to read
391 * @udata: user data buffer to read data into
392 * @count: size of buffer
393 * @offset: offset at which to read data
397 static ssize_t
398 v9fs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
400 struct p9_fid *fid = iocb->ki_filp->private_data;
401 int ret, err = 0;
403 p9_debug(P9_DEBUG_VFS, "count %zu offset %lld\n",
404 iov_iter_count(to), iocb->ki_pos);
406 ret = p9_client_read(fid, iocb->ki_pos, to, &err);
407 if (!ret)
408 return err;
410 iocb->ki_pos += ret;
411 return ret;
415 * v9fs_file_write - write to a file
416 * @filp: file pointer to write
417 * @data: data buffer to write data from
418 * @count: size of buffer
419 * @offset: offset at which to write data
422 static ssize_t
423 v9fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
425 struct file *file = iocb->ki_filp;
426 ssize_t retval;
427 loff_t origin;
428 int err = 0;
430 retval = generic_write_checks(iocb, from);
431 if (retval <= 0)
432 return retval;
434 origin = iocb->ki_pos;
435 retval = p9_client_write(file->private_data, iocb->ki_pos, from, &err);
436 if (retval > 0) {
437 struct inode *inode = file_inode(file);
438 loff_t i_size;
439 unsigned long pg_start, pg_end;
440 pg_start = origin >> PAGE_SHIFT;
441 pg_end = (origin + retval - 1) >> PAGE_SHIFT;
442 if (inode->i_mapping && inode->i_mapping->nrpages)
443 invalidate_inode_pages2_range(inode->i_mapping,
444 pg_start, pg_end);
445 iocb->ki_pos += retval;
446 i_size = i_size_read(inode);
447 if (iocb->ki_pos > i_size) {
448 inode_add_bytes(inode, iocb->ki_pos - i_size);
450 * Need to serialize against i_size_write() in
451 * v9fs_stat2inode()
453 v9fs_i_size_write(inode, iocb->ki_pos);
455 return retval;
457 return err;
460 static int v9fs_file_fsync(struct file *filp, loff_t start, loff_t end,
461 int datasync)
463 struct p9_fid *fid;
464 struct inode *inode = filp->f_mapping->host;
465 struct p9_wstat wstat;
466 int retval;
468 retval = filemap_write_and_wait_range(inode->i_mapping, start, end);
469 if (retval)
470 return retval;
472 inode_lock(inode);
473 p9_debug(P9_DEBUG_VFS, "filp %p datasync %x\n", filp, datasync);
475 fid = filp->private_data;
476 v9fs_blank_wstat(&wstat);
478 retval = p9_client_wstat(fid, &wstat);
479 inode_unlock(inode);
481 return retval;
484 int v9fs_file_fsync_dotl(struct file *filp, loff_t start, loff_t end,
485 int datasync)
487 struct p9_fid *fid;
488 struct inode *inode = filp->f_mapping->host;
489 int retval;
491 retval = filemap_write_and_wait_range(inode->i_mapping, start, end);
492 if (retval)
493 return retval;
495 inode_lock(inode);
496 p9_debug(P9_DEBUG_VFS, "filp %p datasync %x\n", filp, datasync);
498 fid = filp->private_data;
500 retval = p9_client_fsync(fid, datasync);
501 inode_unlock(inode);
503 return retval;
506 static int
507 v9fs_file_mmap(struct file *filp, struct vm_area_struct *vma)
509 int retval;
512 retval = generic_file_mmap(filp, vma);
513 if (!retval)
514 vma->vm_ops = &v9fs_file_vm_ops;
516 return retval;
519 static int
520 v9fs_mmap_file_mmap(struct file *filp, struct vm_area_struct *vma)
522 int retval;
523 struct inode *inode;
524 struct v9fs_inode *v9inode;
525 struct p9_fid *fid;
527 inode = file_inode(filp);
528 v9inode = V9FS_I(inode);
529 mutex_lock(&v9inode->v_mutex);
530 if (!v9inode->writeback_fid &&
531 (vma->vm_flags & VM_SHARED) &&
532 (vma->vm_flags & VM_WRITE)) {
534 * clone a fid and add it to writeback_fid
535 * we do it during mmap instead of
536 * page dirty time via write_begin/page_mkwrite
537 * because we want write after unlink usecase
538 * to work.
540 fid = v9fs_writeback_fid(file_dentry(filp));
541 if (IS_ERR(fid)) {
542 retval = PTR_ERR(fid);
543 mutex_unlock(&v9inode->v_mutex);
544 return retval;
546 v9inode->writeback_fid = (void *) fid;
548 mutex_unlock(&v9inode->v_mutex);
550 retval = generic_file_mmap(filp, vma);
551 if (!retval)
552 vma->vm_ops = &v9fs_mmap_file_vm_ops;
554 return retval;
557 static int
558 v9fs_vm_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
560 struct v9fs_inode *v9inode;
561 struct page *page = vmf->page;
562 struct file *filp = vma->vm_file;
563 struct inode *inode = file_inode(filp);
566 p9_debug(P9_DEBUG_VFS, "page %p fid %lx\n",
567 page, (unsigned long)filp->private_data);
569 /* Update file times before taking page lock */
570 file_update_time(filp);
572 v9inode = V9FS_I(inode);
573 /* make sure the cache has finished storing the page */
574 v9fs_fscache_wait_on_page_write(inode, page);
575 BUG_ON(!v9inode->writeback_fid);
576 lock_page(page);
577 if (page->mapping != inode->i_mapping)
578 goto out_unlock;
579 wait_for_stable_page(page);
581 return VM_FAULT_LOCKED;
582 out_unlock:
583 unlock_page(page);
584 return VM_FAULT_NOPAGE;
588 * v9fs_mmap_file_read - read from a file
589 * @filp: file pointer to read
590 * @data: user data buffer to read data into
591 * @count: size of buffer
592 * @offset: offset at which to read data
595 static ssize_t
596 v9fs_mmap_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
598 /* TODO: Check if there are dirty pages */
599 return v9fs_file_read_iter(iocb, to);
603 * v9fs_mmap_file_write - write to a file
604 * @filp: file pointer to write
605 * @data: data buffer to write data from
606 * @count: size of buffer
607 * @offset: offset at which to write data
610 static ssize_t
611 v9fs_mmap_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
614 * TODO: invalidate mmaps on filp's inode between
615 * offset and offset+count
617 return v9fs_file_write_iter(iocb, from);
620 static void v9fs_mmap_vm_close(struct vm_area_struct *vma)
622 struct inode *inode;
624 struct writeback_control wbc = {
625 .nr_to_write = LONG_MAX,
626 .sync_mode = WB_SYNC_ALL,
627 .range_start = (loff_t)vma->vm_pgoff * PAGE_SIZE,
628 /* absolute end, byte at end included */
629 .range_end = (loff_t)vma->vm_pgoff * PAGE_SIZE +
630 (vma->vm_end - vma->vm_start - 1),
633 if (!(vma->vm_flags & VM_SHARED))
634 return;
636 p9_debug(P9_DEBUG_VFS, "9p VMA close, %p, flushing", vma);
638 inode = file_inode(vma->vm_file);
640 if (!mapping_cap_writeback_dirty(inode->i_mapping))
641 wbc.nr_to_write = 0;
643 might_sleep();
644 sync_inode(inode, &wbc);
648 static const struct vm_operations_struct v9fs_file_vm_ops = {
649 .fault = filemap_fault,
650 .map_pages = filemap_map_pages,
651 .page_mkwrite = v9fs_vm_page_mkwrite,
654 static const struct vm_operations_struct v9fs_mmap_file_vm_ops = {
655 .close = v9fs_mmap_vm_close,
656 .fault = filemap_fault,
657 .map_pages = filemap_map_pages,
658 .page_mkwrite = v9fs_vm_page_mkwrite,
662 const struct file_operations v9fs_cached_file_operations = {
663 .llseek = generic_file_llseek,
664 .read_iter = generic_file_read_iter,
665 .write_iter = generic_file_write_iter,
666 .open = v9fs_file_open,
667 .release = v9fs_dir_release,
668 .lock = v9fs_file_lock,
669 .mmap = v9fs_file_mmap,
670 .fsync = v9fs_file_fsync,
673 const struct file_operations v9fs_cached_file_operations_dotl = {
674 .llseek = generic_file_llseek,
675 .read_iter = generic_file_read_iter,
676 .write_iter = generic_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 = v9fs_file_mmap,
682 .fsync = v9fs_file_fsync_dotl,
685 const struct file_operations v9fs_file_operations = {
686 .llseek = generic_file_llseek,
687 .read_iter = v9fs_file_read_iter,
688 .write_iter = v9fs_file_write_iter,
689 .open = v9fs_file_open,
690 .release = v9fs_dir_release,
691 .lock = v9fs_file_lock,
692 .mmap = generic_file_readonly_mmap,
693 .fsync = v9fs_file_fsync,
696 const struct file_operations v9fs_file_operations_dotl = {
697 .llseek = generic_file_llseek,
698 .read_iter = v9fs_file_read_iter,
699 .write_iter = v9fs_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 = generic_file_readonly_mmap,
705 .fsync = v9fs_file_fsync_dotl,
708 const struct file_operations v9fs_mmap_file_operations = {
709 .llseek = generic_file_llseek,
710 .read_iter = v9fs_mmap_file_read_iter,
711 .write_iter = v9fs_mmap_file_write_iter,
712 .open = v9fs_file_open,
713 .release = v9fs_dir_release,
714 .lock = v9fs_file_lock,
715 .mmap = v9fs_mmap_file_mmap,
716 .fsync = v9fs_file_fsync,
719 const struct file_operations v9fs_mmap_file_operations_dotl = {
720 .llseek = generic_file_llseek,
721 .read_iter = v9fs_mmap_file_read_iter,
722 .write_iter = v9fs_mmap_file_write_iter,
723 .open = v9fs_file_open,
724 .release = v9fs_dir_release,
725 .lock = v9fs_file_lock_dotl,
726 .flock = v9fs_file_flock_dotl,
727 .mmap = v9fs_mmap_file_mmap,
728 .fsync = v9fs_file_fsync_dotl,