2 * linux/fs/9p/vfs_file.c
4 * This file contians vfs file ops for 9P2000.
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>
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 <linux/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>
49 static const struct vm_operations_struct v9fs_file_vm_ops;
50 static const struct vm_operations_struct v9fs_mmap_file_vm_ops;
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)
62 struct v9fs_inode *v9inode;
63 struct v9fs_session_info *v9ses;
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);
73 omode = v9fs_uflags2omode(file->f_flags,
74 v9fs_proto_dotu(v9ses));
75 fid = file->private_data;
77 fid = v9fs_fid_clone(file_dentry(file));
81 err = p9_client_open(fid, omode);
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
103 fid = v9fs_writeback_fid(file_dentry(file));
106 mutex_unlock(&v9inode->v_mutex);
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);
116 p9_client_clunk(file->private_data);
117 file->private_data = NULL;
122 * v9fs_file_lock - lock a file (or directory)
123 * @filp: file to be locked
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)
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)
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);
150 static int v9fs_file_do_lock(struct file *filp, int cmd, struct file_lock *fl)
152 struct p9_flock flock;
154 uint8_t status = P9_LOCK_ERROR;
156 unsigned char fl_type;
157 struct v9fs_session_info *v9ses;
159 fid = filp->private_data;
162 if ((fl->fl_flags & FL_POSIX) != FL_POSIX)
165 res = locks_lock_file_wait(filp, fl);
169 /* convert posix lock to p9 tlock args */
170 memset(&flock, 0, sizeof(flock));
171 /* map the lock type */
172 switch (fl->fl_type) {
174 flock.type = P9_LOCK_TYPE_RDLCK;
177 flock.type = P9_LOCK_TYPE_WRLCK;
180 flock.type = P9_LOCK_TYPE_UNLCK;
183 flock.start = fl->fl_start;
184 if (fl->fl_end == OFFSET_MAX)
187 flock.length = fl->fl_end - fl->fl_start + 1;
188 flock.proc_id = fl->fl_pid;
189 flock.client_id = fid->clnt->name;
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
200 res = p9_client_lock_dotl(fid, &flock, &status);
204 if (status != P9_LOCK_BLOCKED)
206 if (status == P9_LOCK_BLOCKED && !IS_SETLKW(cmd))
208 if (schedule_timeout_interruptible(v9ses->session_lock_timeout)
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 */
223 case P9_LOCK_SUCCESS:
226 case P9_LOCK_BLOCKED:
230 WARN_ONCE(1, "unknown lock status code: %d\n", status);
240 * incase server returned error for lock request, revert
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);
256 static int v9fs_file_getlock(struct file *filp, struct file_lock *fl)
258 struct p9_getlock glock;
262 fid = filp->private_data;
265 posix_test_lock(filp, fl);
267 * if we have a conflicting lock locally, no need to validate
270 if (fl->fl_type != F_UNLCK)
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)
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);
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;
292 case P9_LOCK_TYPE_WRLCK:
293 fl->fl_type = F_WRLCK;
295 case P9_LOCK_TYPE_UNLCK:
296 fl->fl_type = F_UNLCK;
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;
304 fl->fl_end = glock.start + glock.length - 1;
305 fl->fl_pid = -glock.proc_id;
308 if (glock.client_id != fid->clnt->name)
309 kfree(glock.client_id);
314 * v9fs_file_lock_dotl - lock a file (or directory)
315 * @filp: file to be locked
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);
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)
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);
349 * v9fs_file_flock_dotl - lock a file
350 * @filp: file to be locked
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);
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)
369 if (!(fl->fl_flags & FL_FLOCK))
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);
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
398 v9fs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
400 struct p9_fid *fid = iocb->ki_filp->private_data;
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);
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
423 v9fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
425 struct file *file = iocb->ki_filp;
430 retval = generic_write_checks(iocb, from);
434 origin = iocb->ki_pos;
435 retval = p9_client_write(file->private_data, iocb->ki_pos, from, &err);
437 struct inode *inode = file_inode(file);
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,
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);
449 i_size_write(inode, iocb->ki_pos);
456 static int v9fs_file_fsync(struct file *filp, loff_t start, loff_t end,
460 struct inode *inode = filp->f_mapping->host;
461 struct p9_wstat wstat;
464 retval = file_write_and_wait_range(filp, start, end);
469 p9_debug(P9_DEBUG_VFS, "filp %p datasync %x\n", filp, datasync);
471 fid = filp->private_data;
472 v9fs_blank_wstat(&wstat);
474 retval = p9_client_wstat(fid, &wstat);
480 int v9fs_file_fsync_dotl(struct file *filp, loff_t start, loff_t end,
484 struct inode *inode = filp->f_mapping->host;
487 retval = file_write_and_wait_range(filp, start, end);
492 p9_debug(P9_DEBUG_VFS, "filp %p datasync %x\n", filp, datasync);
494 fid = filp->private_data;
496 retval = p9_client_fsync(fid, datasync);
503 v9fs_file_mmap(struct file *filp, struct vm_area_struct *vma)
508 retval = generic_file_mmap(filp, vma);
510 vma->vm_ops = &v9fs_file_vm_ops;
516 v9fs_mmap_file_mmap(struct file *filp, struct vm_area_struct *vma)
520 struct v9fs_inode *v9inode;
523 inode = file_inode(filp);
524 v9inode = V9FS_I(inode);
525 mutex_lock(&v9inode->v_mutex);
526 if (!v9inode->writeback_fid &&
527 (vma->vm_flags & VM_WRITE)) {
529 * clone a fid and add it to writeback_fid
530 * we do it during mmap instead of
531 * page dirty time via write_begin/page_mkwrite
532 * because we want write after unlink usecase
535 fid = v9fs_writeback_fid(file_dentry(filp));
537 retval = PTR_ERR(fid);
538 mutex_unlock(&v9inode->v_mutex);
541 v9inode->writeback_fid = (void *) fid;
543 mutex_unlock(&v9inode->v_mutex);
545 retval = generic_file_mmap(filp, vma);
547 vma->vm_ops = &v9fs_mmap_file_vm_ops;
553 v9fs_vm_page_mkwrite(struct vm_fault *vmf)
555 struct v9fs_inode *v9inode;
556 struct page *page = vmf->page;
557 struct file *filp = vmf->vma->vm_file;
558 struct inode *inode = file_inode(filp);
561 p9_debug(P9_DEBUG_VFS, "page %p fid %lx\n",
562 page, (unsigned long)filp->private_data);
564 /* Update file times before taking page lock */
565 file_update_time(filp);
567 v9inode = V9FS_I(inode);
568 /* make sure the cache has finished storing the page */
569 v9fs_fscache_wait_on_page_write(inode, page);
570 BUG_ON(!v9inode->writeback_fid);
572 if (page->mapping != inode->i_mapping)
574 wait_for_stable_page(page);
576 return VM_FAULT_LOCKED;
579 return VM_FAULT_NOPAGE;
583 * v9fs_mmap_file_read - read from a file
584 * @filp: file pointer to read
585 * @data: user data buffer to read data into
586 * @count: size of buffer
587 * @offset: offset at which to read data
591 v9fs_mmap_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
593 /* TODO: Check if there are dirty pages */
594 return v9fs_file_read_iter(iocb, to);
598 * v9fs_mmap_file_write - write to a file
599 * @filp: file pointer to write
600 * @data: data buffer to write data from
601 * @count: size of buffer
602 * @offset: offset at which to write data
606 v9fs_mmap_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
609 * TODO: invalidate mmaps on filp's inode between
610 * offset and offset+count
612 return v9fs_file_write_iter(iocb, from);
615 static void v9fs_mmap_vm_close(struct vm_area_struct *vma)
619 struct writeback_control wbc = {
620 .nr_to_write = LONG_MAX,
621 .sync_mode = WB_SYNC_ALL,
622 .range_start = vma->vm_pgoff * PAGE_SIZE,
623 /* absolute end, byte at end included */
624 .range_end = vma->vm_pgoff * PAGE_SIZE +
625 (vma->vm_end - vma->vm_start - 1),
629 p9_debug(P9_DEBUG_VFS, "9p VMA close, %p, flushing", vma);
631 inode = file_inode(vma->vm_file);
633 if (!mapping_cap_writeback_dirty(inode->i_mapping))
637 sync_inode(inode, &wbc);
641 static const struct vm_operations_struct v9fs_file_vm_ops = {
642 .fault = filemap_fault,
643 .map_pages = filemap_map_pages,
644 .page_mkwrite = v9fs_vm_page_mkwrite,
647 static const struct vm_operations_struct v9fs_mmap_file_vm_ops = {
648 .close = v9fs_mmap_vm_close,
649 .fault = filemap_fault,
650 .map_pages = filemap_map_pages,
651 .page_mkwrite = v9fs_vm_page_mkwrite,
655 const struct file_operations v9fs_cached_file_operations = {
656 .llseek = generic_file_llseek,
657 .read_iter = generic_file_read_iter,
658 .write_iter = generic_file_write_iter,
659 .open = v9fs_file_open,
660 .release = v9fs_dir_release,
661 .lock = v9fs_file_lock,
662 .mmap = v9fs_file_mmap,
663 .fsync = v9fs_file_fsync,
666 const struct file_operations v9fs_cached_file_operations_dotl = {
667 .llseek = generic_file_llseek,
668 .read_iter = generic_file_read_iter,
669 .write_iter = generic_file_write_iter,
670 .open = v9fs_file_open,
671 .release = v9fs_dir_release,
672 .lock = v9fs_file_lock_dotl,
673 .flock = v9fs_file_flock_dotl,
674 .mmap = v9fs_file_mmap,
675 .fsync = v9fs_file_fsync_dotl,
678 const 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 .fsync = v9fs_file_fsync,
689 const struct file_operations v9fs_file_operations_dotl = {
690 .llseek = generic_file_llseek,
691 .read_iter = v9fs_file_read_iter,
692 .write_iter = v9fs_file_write_iter,
693 .open = v9fs_file_open,
694 .release = v9fs_dir_release,
695 .lock = v9fs_file_lock_dotl,
696 .flock = v9fs_file_flock_dotl,
697 .mmap = generic_file_readonly_mmap,
698 .fsync = v9fs_file_fsync_dotl,
701 const struct file_operations v9fs_mmap_file_operations = {
702 .llseek = generic_file_llseek,
703 .read_iter = v9fs_mmap_file_read_iter,
704 .write_iter = v9fs_mmap_file_write_iter,
705 .open = v9fs_file_open,
706 .release = v9fs_dir_release,
707 .lock = v9fs_file_lock,
708 .mmap = v9fs_mmap_file_mmap,
709 .fsync = v9fs_file_fsync,
712 const struct file_operations v9fs_mmap_file_operations_dotl = {
713 .llseek = generic_file_llseek,
714 .read_iter = v9fs_mmap_file_read_iter,
715 .write_iter = v9fs_mmap_file_write_iter,
716 .open = v9fs_file_open,
717 .release = v9fs_dir_release,
718 .lock = v9fs_file_lock_dotl,
719 .flock = v9fs_file_flock_dotl,
720 .mmap = v9fs_mmap_file_mmap,
721 .fsync = v9fs_file_fsync_dotl,