1 // SPDX-License-Identifier: GPL-2.0-only
3 * linux/fs/9p/vfs_file.c
5 * This file contians vfs file ops for 9P2000.
7 * Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
8 * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
11 #include <linux/module.h>
12 #include <linux/errno.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>
34 static const struct vm_operations_struct v9fs_file_vm_ops;
35 static const struct vm_operations_struct v9fs_mmap_file_vm_ops;
38 * v9fs_file_open - open a file (or directory)
39 * @inode: inode to be opened
40 * @file: file being opened
44 int v9fs_file_open(struct inode *inode, struct file *file)
47 struct v9fs_inode *v9inode;
48 struct v9fs_session_info *v9ses;
49 struct p9_fid *fid, *writeback_fid;
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);
58 omode = v9fs_uflags2omode(file->f_flags,
59 v9fs_proto_dotu(v9ses));
60 fid = file->private_data;
62 fid = v9fs_fid_clone(file_dentry(file));
66 err = p9_client_open(fid, omode);
71 if ((file->f_flags & O_APPEND) &&
72 (!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)))
73 generic_file_llseek(file, 0, SEEK_END);
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)) {
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
88 writeback_fid = v9fs_writeback_fid(file_dentry(file));
89 if (IS_ERR(writeback_fid)) {
90 err = PTR_ERR(writeback_fid);
91 mutex_unlock(&v9inode->v_mutex);
94 v9inode->writeback_fid = (void *) writeback_fid;
96 mutex_unlock(&v9inode->v_mutex);
97 if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
98 v9fs_cache_inode_set_cookie(inode, file);
99 v9fs_open_fid_add(inode, fid);
102 p9_client_clunk(file->private_data);
103 file->private_data = NULL;
108 * v9fs_file_lock - lock a file (or directory)
109 * @filp: file to be locked
111 * @fl: file lock structure
113 * Bugs: this looks like a local only lock, we should extend into 9P
114 * by using open exclusive
117 static int v9fs_file_lock(struct file *filp, int cmd, struct file_lock *fl)
120 struct inode *inode = file_inode(filp);
122 p9_debug(P9_DEBUG_VFS, "filp: %p lock: %p\n", filp, fl);
124 if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
125 filemap_write_and_wait(inode->i_mapping);
126 invalidate_mapping_pages(&inode->i_data, 0, -1);
132 static int v9fs_file_do_lock(struct file *filp, int cmd, struct file_lock *fl)
134 struct p9_flock flock;
136 uint8_t status = P9_LOCK_ERROR;
138 unsigned char fl_type;
139 struct v9fs_session_info *v9ses;
141 fid = filp->private_data;
144 if ((fl->fl_flags & FL_POSIX) != FL_POSIX)
147 res = locks_lock_file_wait(filp, fl);
151 /* convert posix lock to p9 tlock args */
152 memset(&flock, 0, sizeof(flock));
153 /* map the lock type */
154 switch (fl->fl_type) {
156 flock.type = P9_LOCK_TYPE_RDLCK;
159 flock.type = P9_LOCK_TYPE_WRLCK;
162 flock.type = P9_LOCK_TYPE_UNLCK;
165 flock.start = fl->fl_start;
166 if (fl->fl_end == OFFSET_MAX)
169 flock.length = fl->fl_end - fl->fl_start + 1;
170 flock.proc_id = fl->fl_pid;
171 flock.client_id = fid->clnt->name;
173 flock.flags = P9_LOCK_FLAGS_BLOCK;
175 v9ses = v9fs_inode2v9ses(file_inode(filp));
178 * if its a blocked request and we get P9_LOCK_BLOCKED as the status
179 * for lock request, keep on trying
182 res = p9_client_lock_dotl(fid, &flock, &status);
186 if (status != P9_LOCK_BLOCKED)
188 if (status == P9_LOCK_BLOCKED && !IS_SETLKW(cmd))
190 if (schedule_timeout_interruptible(v9ses->session_lock_timeout)
194 * p9_client_lock_dotl overwrites flock.client_id with the
195 * server message, free and reuse the client name
197 if (flock.client_id != fid->clnt->name) {
198 kfree(flock.client_id);
199 flock.client_id = fid->clnt->name;
203 /* map 9p status to VFS status */
205 case P9_LOCK_SUCCESS:
208 case P9_LOCK_BLOCKED:
212 WARN_ONCE(1, "unknown lock status code: %d\n", status);
222 * incase server returned error for lock request, revert
225 if (res < 0 && fl->fl_type != F_UNLCK) {
226 fl_type = fl->fl_type;
227 fl->fl_type = F_UNLCK;
228 /* Even if this fails we want to return the remote error */
229 locks_lock_file_wait(filp, fl);
230 fl->fl_type = fl_type;
232 if (flock.client_id != fid->clnt->name)
233 kfree(flock.client_id);
238 static int v9fs_file_getlock(struct file *filp, struct file_lock *fl)
240 struct p9_getlock glock;
244 fid = filp->private_data;
247 posix_test_lock(filp, fl);
249 * if we have a conflicting lock locally, no need to validate
252 if (fl->fl_type != F_UNLCK)
255 /* convert posix lock to p9 tgetlock args */
256 memset(&glock, 0, sizeof(glock));
257 glock.type = P9_LOCK_TYPE_UNLCK;
258 glock.start = fl->fl_start;
259 if (fl->fl_end == OFFSET_MAX)
262 glock.length = fl->fl_end - fl->fl_start + 1;
263 glock.proc_id = fl->fl_pid;
264 glock.client_id = fid->clnt->name;
266 res = p9_client_getlock_dotl(fid, &glock);
269 /* map 9p lock type to os lock type */
270 switch (glock.type) {
271 case P9_LOCK_TYPE_RDLCK:
272 fl->fl_type = F_RDLCK;
274 case P9_LOCK_TYPE_WRLCK:
275 fl->fl_type = F_WRLCK;
277 case P9_LOCK_TYPE_UNLCK:
278 fl->fl_type = F_UNLCK;
281 if (glock.type != P9_LOCK_TYPE_UNLCK) {
282 fl->fl_start = glock.start;
283 if (glock.length == 0)
284 fl->fl_end = OFFSET_MAX;
286 fl->fl_end = glock.start + glock.length - 1;
287 fl->fl_pid = -glock.proc_id;
290 if (glock.client_id != fid->clnt->name)
291 kfree(glock.client_id);
296 * v9fs_file_lock_dotl - lock a file (or directory)
297 * @filp: file to be locked
299 * @fl: file lock structure
303 static int v9fs_file_lock_dotl(struct file *filp, int cmd, struct file_lock *fl)
305 struct inode *inode = file_inode(filp);
308 p9_debug(P9_DEBUG_VFS, "filp: %p cmd:%d lock: %p name: %pD\n",
309 filp, cmd, fl, filp);
311 if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
312 filemap_write_and_wait(inode->i_mapping);
313 invalidate_mapping_pages(&inode->i_data, 0, -1);
316 if (IS_SETLK(cmd) || IS_SETLKW(cmd))
317 ret = v9fs_file_do_lock(filp, cmd, fl);
318 else if (IS_GETLK(cmd))
319 ret = v9fs_file_getlock(filp, fl);
326 * v9fs_file_flock_dotl - lock a file
327 * @filp: file to be locked
329 * @fl: file lock structure
333 static int v9fs_file_flock_dotl(struct file *filp, int cmd,
334 struct file_lock *fl)
336 struct inode *inode = file_inode(filp);
339 p9_debug(P9_DEBUG_VFS, "filp: %p cmd:%d lock: %p name: %pD\n",
340 filp, cmd, fl, filp);
342 if (!(fl->fl_flags & FL_FLOCK))
345 if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
346 filemap_write_and_wait(inode->i_mapping);
347 invalidate_mapping_pages(&inode->i_data, 0, -1);
349 /* Convert flock to posix lock */
350 fl->fl_flags |= FL_POSIX;
351 fl->fl_flags ^= FL_FLOCK;
353 if (IS_SETLK(cmd) | IS_SETLKW(cmd))
354 ret = v9fs_file_do_lock(filp, cmd, fl);
362 * v9fs_file_read - read from a file
363 * @filp: file pointer to read
364 * @udata: user data buffer to read data into
365 * @count: size of buffer
366 * @offset: offset at which to read data
371 v9fs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
373 struct p9_fid *fid = iocb->ki_filp->private_data;
376 p9_debug(P9_DEBUG_VFS, "count %zu offset %lld\n",
377 iov_iter_count(to), iocb->ki_pos);
379 if (iocb->ki_filp->f_flags & O_NONBLOCK)
380 ret = p9_client_read_once(fid, iocb->ki_pos, to, &err);
382 ret = p9_client_read(fid, iocb->ki_pos, to, &err);
391 * v9fs_file_write - write to a file
392 * @filp: file pointer to write
393 * @data: data buffer to write data from
394 * @count: size of buffer
395 * @offset: offset at which to write data
399 v9fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
401 struct file *file = iocb->ki_filp;
406 retval = generic_write_checks(iocb, from);
410 origin = iocb->ki_pos;
411 retval = p9_client_write(file->private_data, iocb->ki_pos, from, &err);
413 struct inode *inode = file_inode(file);
415 unsigned long pg_start, pg_end;
416 pg_start = origin >> PAGE_SHIFT;
417 pg_end = (origin + retval - 1) >> PAGE_SHIFT;
418 if (inode->i_mapping && inode->i_mapping->nrpages)
419 invalidate_inode_pages2_range(inode->i_mapping,
421 iocb->ki_pos += retval;
422 i_size = i_size_read(inode);
423 if (iocb->ki_pos > i_size) {
424 inode_add_bytes(inode, iocb->ki_pos - i_size);
426 * Need to serialize against i_size_write() in
429 v9fs_i_size_write(inode, iocb->ki_pos);
436 static int v9fs_file_fsync(struct file *filp, loff_t start, loff_t end,
440 struct inode *inode = filp->f_mapping->host;
441 struct p9_wstat wstat;
444 retval = file_write_and_wait_range(filp, start, end);
449 p9_debug(P9_DEBUG_VFS, "filp %p datasync %x\n", filp, datasync);
451 fid = filp->private_data;
452 v9fs_blank_wstat(&wstat);
454 retval = p9_client_wstat(fid, &wstat);
460 int v9fs_file_fsync_dotl(struct file *filp, loff_t start, loff_t end,
464 struct inode *inode = filp->f_mapping->host;
467 retval = file_write_and_wait_range(filp, start, end);
472 p9_debug(P9_DEBUG_VFS, "filp %p datasync %x\n", filp, datasync);
474 fid = filp->private_data;
476 retval = p9_client_fsync(fid, datasync);
483 v9fs_file_mmap(struct file *filp, struct vm_area_struct *vma)
488 retval = generic_file_mmap(filp, vma);
490 vma->vm_ops = &v9fs_file_vm_ops;
496 v9fs_mmap_file_mmap(struct file *filp, struct vm_area_struct *vma)
500 struct v9fs_inode *v9inode;
503 inode = file_inode(filp);
504 v9inode = V9FS_I(inode);
505 mutex_lock(&v9inode->v_mutex);
506 if (!v9inode->writeback_fid &&
507 (vma->vm_flags & VM_SHARED) &&
508 (vma->vm_flags & VM_WRITE)) {
510 * clone a fid and add it to writeback_fid
511 * we do it during mmap instead of
512 * page dirty time via write_begin/page_mkwrite
513 * because we want write after unlink usecase
516 fid = v9fs_writeback_fid(file_dentry(filp));
518 retval = PTR_ERR(fid);
519 mutex_unlock(&v9inode->v_mutex);
522 v9inode->writeback_fid = (void *) fid;
524 mutex_unlock(&v9inode->v_mutex);
526 retval = generic_file_mmap(filp, vma);
528 vma->vm_ops = &v9fs_mmap_file_vm_ops;
534 v9fs_vm_page_mkwrite(struct vm_fault *vmf)
536 struct v9fs_inode *v9inode;
537 struct page *page = vmf->page;
538 struct file *filp = vmf->vma->vm_file;
539 struct inode *inode = file_inode(filp);
542 p9_debug(P9_DEBUG_VFS, "page %p fid %lx\n",
543 page, (unsigned long)filp->private_data);
545 /* Update file times before taking page lock */
546 file_update_time(filp);
548 v9inode = V9FS_I(inode);
549 /* make sure the cache has finished storing the page */
550 v9fs_fscache_wait_on_page_write(inode, page);
551 BUG_ON(!v9inode->writeback_fid);
553 if (page->mapping != inode->i_mapping)
555 wait_for_stable_page(page);
557 return VM_FAULT_LOCKED;
560 return VM_FAULT_NOPAGE;
564 * v9fs_mmap_file_read - read from a file
565 * @filp: file pointer to read
566 * @data: user data buffer to read data into
567 * @count: size of buffer
568 * @offset: offset at which to read data
572 v9fs_mmap_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
574 /* TODO: Check if there are dirty pages */
575 return v9fs_file_read_iter(iocb, to);
579 * v9fs_mmap_file_write - write to a file
580 * @filp: file pointer to write
581 * @data: data buffer to write data from
582 * @count: size of buffer
583 * @offset: offset at which to write data
587 v9fs_mmap_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
590 * TODO: invalidate mmaps on filp's inode between
591 * offset and offset+count
593 return v9fs_file_write_iter(iocb, from);
596 static void v9fs_mmap_vm_close(struct vm_area_struct *vma)
600 struct writeback_control wbc = {
601 .nr_to_write = LONG_MAX,
602 .sync_mode = WB_SYNC_ALL,
603 .range_start = (loff_t)vma->vm_pgoff * PAGE_SIZE,
604 /* absolute end, byte at end included */
605 .range_end = (loff_t)vma->vm_pgoff * PAGE_SIZE +
606 (vma->vm_end - vma->vm_start - 1),
609 if (!(vma->vm_flags & VM_SHARED))
612 p9_debug(P9_DEBUG_VFS, "9p VMA close, %p, flushing", vma);
614 inode = file_inode(vma->vm_file);
615 filemap_fdatawrite_wbc(inode->i_mapping, &wbc);
619 static const struct vm_operations_struct v9fs_file_vm_ops = {
620 .fault = filemap_fault,
621 .map_pages = filemap_map_pages,
622 .page_mkwrite = v9fs_vm_page_mkwrite,
625 static const struct vm_operations_struct v9fs_mmap_file_vm_ops = {
626 .close = v9fs_mmap_vm_close,
627 .fault = filemap_fault,
628 .map_pages = filemap_map_pages,
629 .page_mkwrite = v9fs_vm_page_mkwrite,
633 const struct file_operations v9fs_cached_file_operations = {
634 .llseek = generic_file_llseek,
635 .read_iter = generic_file_read_iter,
636 .write_iter = generic_file_write_iter,
637 .open = v9fs_file_open,
638 .release = v9fs_dir_release,
639 .lock = v9fs_file_lock,
640 .mmap = v9fs_file_mmap,
641 .splice_read = generic_file_splice_read,
642 .splice_write = iter_file_splice_write,
643 .fsync = v9fs_file_fsync,
646 const struct file_operations v9fs_cached_file_operations_dotl = {
647 .llseek = generic_file_llseek,
648 .read_iter = generic_file_read_iter,
649 .write_iter = generic_file_write_iter,
650 .open = v9fs_file_open,
651 .release = v9fs_dir_release,
652 .lock = v9fs_file_lock_dotl,
653 .flock = v9fs_file_flock_dotl,
654 .mmap = v9fs_file_mmap,
655 .splice_read = generic_file_splice_read,
656 .splice_write = iter_file_splice_write,
657 .fsync = v9fs_file_fsync_dotl,
660 const struct file_operations v9fs_file_operations = {
661 .llseek = generic_file_llseek,
662 .read_iter = v9fs_file_read_iter,
663 .write_iter = v9fs_file_write_iter,
664 .open = v9fs_file_open,
665 .release = v9fs_dir_release,
666 .lock = v9fs_file_lock,
667 .mmap = generic_file_readonly_mmap,
668 .splice_read = generic_file_splice_read,
669 .splice_write = iter_file_splice_write,
670 .fsync = v9fs_file_fsync,
673 const struct file_operations v9fs_file_operations_dotl = {
674 .llseek = generic_file_llseek,
675 .read_iter = v9fs_file_read_iter,
676 .write_iter = v9fs_file_write_iter,
677 .open = v9fs_file_open,
678 .release = v9fs_dir_release,
679 .lock = v9fs_file_lock_dotl,
680 .flock = v9fs_file_flock_dotl,
681 .mmap = generic_file_readonly_mmap,
682 .splice_read = generic_file_splice_read,
683 .splice_write = iter_file_splice_write,
684 .fsync = v9fs_file_fsync_dotl,
687 const struct file_operations v9fs_mmap_file_operations = {
688 .llseek = generic_file_llseek,
689 .read_iter = v9fs_mmap_file_read_iter,
690 .write_iter = v9fs_mmap_file_write_iter,
691 .open = v9fs_file_open,
692 .release = v9fs_dir_release,
693 .lock = v9fs_file_lock,
694 .mmap = v9fs_mmap_file_mmap,
695 .splice_read = generic_file_splice_read,
696 .splice_write = iter_file_splice_write,
697 .fsync = v9fs_file_fsync,
700 const struct file_operations v9fs_mmap_file_operations_dotl = {
701 .llseek = generic_file_llseek,
702 .read_iter = v9fs_mmap_file_read_iter,
703 .write_iter = v9fs_mmap_file_write_iter,
704 .open = v9fs_file_open,
705 .release = v9fs_dir_release,
706 .lock = v9fs_file_lock_dotl,
707 .flock = v9fs_file_flock_dotl,
708 .mmap = v9fs_mmap_file_mmap,
709 .splice_read = generic_file_splice_read,
710 .splice_write = iter_file_splice_write,
711 .fsync = v9fs_file_fsync_dotl,