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;
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 fid = v9fs_writeback_fid(file_dentry(file));
91 mutex_unlock(&v9inode->v_mutex);
94 v9inode->writeback_fid = (void *) 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);
101 p9_client_clunk(file->private_data);
102 file->private_data = NULL;
107 * v9fs_file_lock - lock a file (or directory)
108 * @filp: file to be locked
110 * @fl: file lock structure
112 * Bugs: this looks like a local only lock, we should extend into 9P
113 * by using open exclusive
116 static int v9fs_file_lock(struct file *filp, int cmd, struct file_lock *fl)
119 struct inode *inode = file_inode(filp);
121 p9_debug(P9_DEBUG_VFS, "filp: %p lock: %p\n", filp, fl);
123 /* No mandatory locks */
124 if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
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);
135 static int v9fs_file_do_lock(struct file *filp, int cmd, struct file_lock *fl)
137 struct p9_flock flock;
139 uint8_t status = P9_LOCK_ERROR;
141 unsigned char fl_type;
142 struct v9fs_session_info *v9ses;
144 fid = filp->private_data;
147 if ((fl->fl_flags & FL_POSIX) != FL_POSIX)
150 res = locks_lock_file_wait(filp, fl);
154 /* convert posix lock to p9 tlock args */
155 memset(&flock, 0, sizeof(flock));
156 /* map the lock type */
157 switch (fl->fl_type) {
159 flock.type = P9_LOCK_TYPE_RDLCK;
162 flock.type = P9_LOCK_TYPE_WRLCK;
165 flock.type = P9_LOCK_TYPE_UNLCK;
168 flock.start = fl->fl_start;
169 if (fl->fl_end == OFFSET_MAX)
172 flock.length = fl->fl_end - fl->fl_start + 1;
173 flock.proc_id = fl->fl_pid;
174 flock.client_id = fid->clnt->name;
176 flock.flags = P9_LOCK_FLAGS_BLOCK;
178 v9ses = v9fs_inode2v9ses(file_inode(filp));
181 * if its a blocked request and we get P9_LOCK_BLOCKED as the status
182 * for lock request, keep on trying
185 res = p9_client_lock_dotl(fid, &flock, &status);
189 if (status != P9_LOCK_BLOCKED)
191 if (status == P9_LOCK_BLOCKED && !IS_SETLKW(cmd))
193 if (schedule_timeout_interruptible(v9ses->session_lock_timeout)
197 * p9_client_lock_dotl overwrites flock.client_id with the
198 * server message, free and reuse the client name
200 if (flock.client_id != fid->clnt->name) {
201 kfree(flock.client_id);
202 flock.client_id = fid->clnt->name;
206 /* map 9p status to VFS status */
208 case P9_LOCK_SUCCESS:
211 case P9_LOCK_BLOCKED:
215 WARN_ONCE(1, "unknown lock status code: %d\n", status);
225 * incase server returned error for lock request, revert
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;
235 if (flock.client_id != fid->clnt->name)
236 kfree(flock.client_id);
241 static int v9fs_file_getlock(struct file *filp, struct file_lock *fl)
243 struct p9_getlock glock;
247 fid = filp->private_data;
250 posix_test_lock(filp, fl);
252 * if we have a conflicting lock locally, no need to validate
255 if (fl->fl_type != F_UNLCK)
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)
265 glock.length = fl->fl_end - fl->fl_start + 1;
266 glock.proc_id = fl->fl_pid;
267 glock.client_id = fid->clnt->name;
269 res = p9_client_getlock_dotl(fid, &glock);
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;
277 case P9_LOCK_TYPE_WRLCK:
278 fl->fl_type = F_WRLCK;
280 case P9_LOCK_TYPE_UNLCK:
281 fl->fl_type = F_UNLCK;
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;
289 fl->fl_end = glock.start + glock.length - 1;
290 fl->fl_pid = -glock.proc_id;
293 if (glock.client_id != fid->clnt->name)
294 kfree(glock.client_id);
299 * v9fs_file_lock_dotl - lock a file (or directory)
300 * @filp: file to be locked
302 * @fl: file lock structure
306 static int v9fs_file_lock_dotl(struct file *filp, int cmd, struct file_lock *fl)
308 struct inode *inode = file_inode(filp);
311 p9_debug(P9_DEBUG_VFS, "filp: %p cmd:%d lock: %p name: %pD\n",
312 filp, cmd, fl, filp);
314 /* No mandatory locks */
315 if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
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);
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);
334 * v9fs_file_flock_dotl - lock a file
335 * @filp: file to be locked
337 * @fl: file lock structure
341 static int v9fs_file_flock_dotl(struct file *filp, int cmd,
342 struct file_lock *fl)
344 struct inode *inode = file_inode(filp);
347 p9_debug(P9_DEBUG_VFS, "filp: %p cmd:%d lock: %p name: %pD\n",
348 filp, cmd, fl, filp);
350 /* No mandatory locks */
351 if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
354 if (!(fl->fl_flags & FL_FLOCK))
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);
361 /* Convert flock to posix lock */
362 fl->fl_flags |= FL_POSIX;
363 fl->fl_flags ^= FL_FLOCK;
365 if (IS_SETLK(cmd) | IS_SETLKW(cmd))
366 ret = v9fs_file_do_lock(filp, cmd, fl);
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
383 v9fs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
385 struct p9_fid *fid = iocb->ki_filp->private_data;
388 p9_debug(P9_DEBUG_VFS, "count %zu offset %lld\n",
389 iov_iter_count(to), iocb->ki_pos);
391 ret = p9_client_read(fid, iocb->ki_pos, to, &err);
400 * v9fs_file_write - write to a file
401 * @filp: file pointer to write
402 * @data: data buffer to write data from
403 * @count: size of buffer
404 * @offset: offset at which to write data
408 v9fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
410 struct file *file = iocb->ki_filp;
415 retval = generic_write_checks(iocb, from);
419 origin = iocb->ki_pos;
420 retval = p9_client_write(file->private_data, iocb->ki_pos, from, &err);
422 struct inode *inode = file_inode(file);
424 unsigned long pg_start, pg_end;
425 pg_start = origin >> PAGE_SHIFT;
426 pg_end = (origin + retval - 1) >> PAGE_SHIFT;
427 if (inode->i_mapping && inode->i_mapping->nrpages)
428 invalidate_inode_pages2_range(inode->i_mapping,
430 iocb->ki_pos += retval;
431 i_size = i_size_read(inode);
432 if (iocb->ki_pos > i_size) {
433 inode_add_bytes(inode, iocb->ki_pos - i_size);
435 * Need to serialize against i_size_write() in
438 v9fs_i_size_write(inode, iocb->ki_pos);
445 static int v9fs_file_fsync(struct file *filp, loff_t start, loff_t end,
449 struct inode *inode = filp->f_mapping->host;
450 struct p9_wstat wstat;
453 retval = file_write_and_wait_range(filp, start, end);
458 p9_debug(P9_DEBUG_VFS, "filp %p datasync %x\n", filp, datasync);
460 fid = filp->private_data;
461 v9fs_blank_wstat(&wstat);
463 retval = p9_client_wstat(fid, &wstat);
469 int v9fs_file_fsync_dotl(struct file *filp, loff_t start, loff_t end,
473 struct inode *inode = filp->f_mapping->host;
476 retval = file_write_and_wait_range(filp, start, end);
481 p9_debug(P9_DEBUG_VFS, "filp %p datasync %x\n", filp, datasync);
483 fid = filp->private_data;
485 retval = p9_client_fsync(fid, datasync);
492 v9fs_file_mmap(struct file *filp, struct vm_area_struct *vma)
497 retval = generic_file_mmap(filp, vma);
499 vma->vm_ops = &v9fs_file_vm_ops;
505 v9fs_mmap_file_mmap(struct file *filp, struct vm_area_struct *vma)
509 struct v9fs_inode *v9inode;
512 inode = file_inode(filp);
513 v9inode = V9FS_I(inode);
514 mutex_lock(&v9inode->v_mutex);
515 if (!v9inode->writeback_fid &&
516 (vma->vm_flags & VM_SHARED) &&
517 (vma->vm_flags & VM_WRITE)) {
519 * clone a fid and add it to writeback_fid
520 * we do it during mmap instead of
521 * page dirty time via write_begin/page_mkwrite
522 * because we want write after unlink usecase
525 fid = v9fs_writeback_fid(file_dentry(filp));
527 retval = PTR_ERR(fid);
528 mutex_unlock(&v9inode->v_mutex);
531 v9inode->writeback_fid = (void *) fid;
533 mutex_unlock(&v9inode->v_mutex);
535 retval = generic_file_mmap(filp, vma);
537 vma->vm_ops = &v9fs_mmap_file_vm_ops;
543 v9fs_vm_page_mkwrite(struct vm_fault *vmf)
545 struct v9fs_inode *v9inode;
546 struct page *page = vmf->page;
547 struct file *filp = vmf->vma->vm_file;
548 struct inode *inode = file_inode(filp);
551 p9_debug(P9_DEBUG_VFS, "page %p fid %lx\n",
552 page, (unsigned long)filp->private_data);
554 /* Update file times before taking page lock */
555 file_update_time(filp);
557 v9inode = V9FS_I(inode);
558 /* make sure the cache has finished storing the page */
559 v9fs_fscache_wait_on_page_write(inode, page);
560 BUG_ON(!v9inode->writeback_fid);
562 if (page->mapping != inode->i_mapping)
564 wait_for_stable_page(page);
566 return VM_FAULT_LOCKED;
569 return VM_FAULT_NOPAGE;
573 * v9fs_mmap_file_read - read from a file
574 * @filp: file pointer to read
575 * @data: user data buffer to read data into
576 * @count: size of buffer
577 * @offset: offset at which to read data
581 v9fs_mmap_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
583 /* TODO: Check if there are dirty pages */
584 return v9fs_file_read_iter(iocb, to);
588 * v9fs_mmap_file_write - write to a file
589 * @filp: file pointer to write
590 * @data: data buffer to write data from
591 * @count: size of buffer
592 * @offset: offset at which to write data
596 v9fs_mmap_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
599 * TODO: invalidate mmaps on filp's inode between
600 * offset and offset+count
602 return v9fs_file_write_iter(iocb, from);
605 static void v9fs_mmap_vm_close(struct vm_area_struct *vma)
609 struct writeback_control wbc = {
610 .nr_to_write = LONG_MAX,
611 .sync_mode = WB_SYNC_ALL,
612 .range_start = vma->vm_pgoff * PAGE_SIZE,
613 /* absolute end, byte at end included */
614 .range_end = vma->vm_pgoff * PAGE_SIZE +
615 (vma->vm_end - vma->vm_start - 1),
618 if (!(vma->vm_flags & VM_SHARED))
621 p9_debug(P9_DEBUG_VFS, "9p VMA close, %p, flushing", vma);
623 inode = file_inode(vma->vm_file);
625 if (!mapping_cap_writeback_dirty(inode->i_mapping))
629 sync_inode(inode, &wbc);
633 static const struct vm_operations_struct v9fs_file_vm_ops = {
634 .fault = filemap_fault,
635 .map_pages = filemap_map_pages,
636 .page_mkwrite = v9fs_vm_page_mkwrite,
639 static const struct vm_operations_struct v9fs_mmap_file_vm_ops = {
640 .close = v9fs_mmap_vm_close,
641 .fault = filemap_fault,
642 .map_pages = filemap_map_pages,
643 .page_mkwrite = v9fs_vm_page_mkwrite,
647 const struct file_operations v9fs_cached_file_operations = {
648 .llseek = generic_file_llseek,
649 .read_iter = generic_file_read_iter,
650 .write_iter = generic_file_write_iter,
651 .open = v9fs_file_open,
652 .release = v9fs_dir_release,
653 .lock = v9fs_file_lock,
654 .mmap = v9fs_file_mmap,
655 .fsync = v9fs_file_fsync,
658 const struct file_operations v9fs_cached_file_operations_dotl = {
659 .llseek = generic_file_llseek,
660 .read_iter = generic_file_read_iter,
661 .write_iter = generic_file_write_iter,
662 .open = v9fs_file_open,
663 .release = v9fs_dir_release,
664 .lock = v9fs_file_lock_dotl,
665 .flock = v9fs_file_flock_dotl,
666 .mmap = v9fs_file_mmap,
667 .fsync = v9fs_file_fsync_dotl,
670 const struct file_operations v9fs_file_operations = {
671 .llseek = generic_file_llseek,
672 .read_iter = v9fs_file_read_iter,
673 .write_iter = v9fs_file_write_iter,
674 .open = v9fs_file_open,
675 .release = v9fs_dir_release,
676 .lock = v9fs_file_lock,
677 .mmap = generic_file_readonly_mmap,
678 .fsync = v9fs_file_fsync,
681 const struct file_operations v9fs_file_operations_dotl = {
682 .llseek = generic_file_llseek,
683 .read_iter = v9fs_file_read_iter,
684 .write_iter = v9fs_file_write_iter,
685 .open = v9fs_file_open,
686 .release = v9fs_dir_release,
687 .lock = v9fs_file_lock_dotl,
688 .flock = v9fs_file_flock_dotl,
689 .mmap = generic_file_readonly_mmap,
690 .fsync = v9fs_file_fsync_dotl,
693 const struct file_operations v9fs_mmap_file_operations = {
694 .llseek = generic_file_llseek,
695 .read_iter = v9fs_mmap_file_read_iter,
696 .write_iter = v9fs_mmap_file_write_iter,
697 .open = v9fs_file_open,
698 .release = v9fs_dir_release,
699 .lock = v9fs_file_lock,
700 .mmap = v9fs_mmap_file_mmap,
701 .fsync = v9fs_file_fsync,
704 const struct file_operations v9fs_mmap_file_operations_dotl = {
705 .llseek = generic_file_llseek,
706 .read_iter = v9fs_mmap_file_read_iter,
707 .write_iter = v9fs_mmap_file_write_iter,
708 .open = v9fs_file_open,
709 .release = v9fs_dir_release,
710 .lock = v9fs_file_lock_dotl,
711 .flock = v9fs_file_flock_dotl,
712 .mmap = v9fs_mmap_file_mmap,
713 .fsync = v9fs_file_fsync_dotl,