1 // SPDX-License-Identifier: GPL-2.0-only
3 * This file contians vfs file ops for 9P2000.
5 * Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
6 * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
9 #include <linux/module.h>
10 #include <linux/errno.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/inet.h>
18 #include <linux/list.h>
19 #include <linux/pagemap.h>
20 #include <linux/utsname.h>
21 #include <linux/uaccess.h>
22 #include <linux/uio.h>
23 #include <linux/slab.h>
24 #include <net/9p/9p.h>
25 #include <net/9p/client.h>
32 static const struct vm_operations_struct v9fs_mmap_file_vm_ops;
35 * v9fs_file_open - open a file (or directory)
36 * @inode: inode to be opened
37 * @file: file being opened
41 int v9fs_file_open(struct inode *inode, struct file *file)
44 struct v9fs_session_info *v9ses;
48 p9_debug(P9_DEBUG_VFS, "inode: %p file: %p\n", inode, file);
49 v9ses = v9fs_inode2v9ses(inode);
50 if (v9fs_proto_dotl(v9ses))
51 omode = v9fs_open_to_dotl_flags(file->f_flags);
53 omode = v9fs_uflags2omode(file->f_flags,
54 v9fs_proto_dotu(v9ses));
55 fid = file->private_data;
57 fid = v9fs_fid_clone(file_dentry(file));
61 if ((v9ses->cache & CACHE_WRITEBACK) && (omode & P9_OWRITE)) {
62 int writeback_omode = (omode & ~P9_OWRITE) | P9_ORDWR;
64 p9_debug(P9_DEBUG_CACHE, "write-only file with writeback enabled, try opening O_RDWR\n");
65 err = p9_client_open(fid, writeback_omode);
67 p9_debug(P9_DEBUG_CACHE, "could not open O_RDWR, disabling caches\n");
68 err = p9_client_open(fid, omode);
69 fid->mode |= P9L_DIRECT;
72 err = p9_client_open(fid, omode);
78 if ((file->f_flags & O_APPEND) &&
79 (!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)))
80 generic_file_llseek(file, 0, SEEK_END);
82 file->private_data = fid;
85 #ifdef CONFIG_9P_FSCACHE
86 if (v9ses->cache & CACHE_FSCACHE)
87 fscache_use_cookie(v9fs_inode_cookie(V9FS_I(inode)),
88 file->f_mode & FMODE_WRITE);
90 v9fs_fid_add_modes(fid, v9ses->flags, v9ses->cache, file->f_flags);
91 v9fs_open_fid_add(inode, &fid);
96 * v9fs_file_lock - lock a file (or directory)
97 * @filp: file to be locked
99 * @fl: file lock structure
101 * Bugs: this looks like a local only lock, we should extend into 9P
102 * by using open exclusive
105 static int v9fs_file_lock(struct file *filp, int cmd, struct file_lock *fl)
107 struct inode *inode = file_inode(filp);
109 p9_debug(P9_DEBUG_VFS, "filp: %p lock: %p\n", filp, fl);
111 if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
112 filemap_write_and_wait(inode->i_mapping);
113 invalidate_mapping_pages(&inode->i_data, 0, -1);
119 static int v9fs_file_do_lock(struct file *filp, int cmd, struct file_lock *fl)
121 struct p9_flock flock;
123 uint8_t status = P9_LOCK_ERROR;
125 unsigned char fl_type;
126 struct v9fs_session_info *v9ses;
128 fid = filp->private_data;
131 BUG_ON((fl->fl_flags & FL_POSIX) != FL_POSIX);
133 res = locks_lock_file_wait(filp, fl);
137 /* convert posix lock to p9 tlock args */
138 memset(&flock, 0, sizeof(flock));
139 /* map the lock type */
140 switch (fl->fl_type) {
142 flock.type = P9_LOCK_TYPE_RDLCK;
145 flock.type = P9_LOCK_TYPE_WRLCK;
148 flock.type = P9_LOCK_TYPE_UNLCK;
151 flock.start = fl->fl_start;
152 if (fl->fl_end == OFFSET_MAX)
155 flock.length = fl->fl_end - fl->fl_start + 1;
156 flock.proc_id = fl->fl_pid;
157 flock.client_id = fid->clnt->name;
159 flock.flags = P9_LOCK_FLAGS_BLOCK;
161 v9ses = v9fs_inode2v9ses(file_inode(filp));
164 * if its a blocked request and we get P9_LOCK_BLOCKED as the status
165 * for lock request, keep on trying
168 res = p9_client_lock_dotl(fid, &flock, &status);
172 if (status != P9_LOCK_BLOCKED)
174 if (status == P9_LOCK_BLOCKED && !IS_SETLKW(cmd))
176 if (schedule_timeout_interruptible(v9ses->session_lock_timeout)
180 * p9_client_lock_dotl overwrites flock.client_id with the
181 * server message, free and reuse the client name
183 if (flock.client_id != fid->clnt->name) {
184 kfree(flock.client_id);
185 flock.client_id = fid->clnt->name;
189 /* map 9p status to VFS status */
191 case P9_LOCK_SUCCESS:
194 case P9_LOCK_BLOCKED:
198 WARN_ONCE(1, "unknown lock status code: %d\n", status);
208 * incase server returned error for lock request, revert
211 if (res < 0 && fl->fl_type != F_UNLCK) {
212 fl_type = fl->fl_type;
213 fl->fl_type = F_UNLCK;
214 /* Even if this fails we want to return the remote error */
215 locks_lock_file_wait(filp, fl);
216 fl->fl_type = fl_type;
218 if (flock.client_id != fid->clnt->name)
219 kfree(flock.client_id);
224 static int v9fs_file_getlock(struct file *filp, struct file_lock *fl)
226 struct p9_getlock glock;
230 fid = filp->private_data;
233 posix_test_lock(filp, fl);
235 * if we have a conflicting lock locally, no need to validate
238 if (fl->fl_type != F_UNLCK)
241 /* convert posix lock to p9 tgetlock args */
242 memset(&glock, 0, sizeof(glock));
243 glock.type = P9_LOCK_TYPE_UNLCK;
244 glock.start = fl->fl_start;
245 if (fl->fl_end == OFFSET_MAX)
248 glock.length = fl->fl_end - fl->fl_start + 1;
249 glock.proc_id = fl->fl_pid;
250 glock.client_id = fid->clnt->name;
252 res = p9_client_getlock_dotl(fid, &glock);
255 /* map 9p lock type to os lock type */
256 switch (glock.type) {
257 case P9_LOCK_TYPE_RDLCK:
258 fl->fl_type = F_RDLCK;
260 case P9_LOCK_TYPE_WRLCK:
261 fl->fl_type = F_WRLCK;
263 case P9_LOCK_TYPE_UNLCK:
264 fl->fl_type = F_UNLCK;
267 if (glock.type != P9_LOCK_TYPE_UNLCK) {
268 fl->fl_start = glock.start;
269 if (glock.length == 0)
270 fl->fl_end = OFFSET_MAX;
272 fl->fl_end = glock.start + glock.length - 1;
273 fl->fl_pid = -glock.proc_id;
276 if (glock.client_id != fid->clnt->name)
277 kfree(glock.client_id);
282 * v9fs_file_lock_dotl - lock a file (or directory)
283 * @filp: file to be locked
285 * @fl: file lock structure
289 static int v9fs_file_lock_dotl(struct file *filp, int cmd, struct file_lock *fl)
291 struct inode *inode = file_inode(filp);
294 p9_debug(P9_DEBUG_VFS, "filp: %p cmd:%d lock: %p name: %pD\n",
295 filp, cmd, fl, filp);
297 if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
298 filemap_write_and_wait(inode->i_mapping);
299 invalidate_mapping_pages(&inode->i_data, 0, -1);
302 if (IS_SETLK(cmd) || IS_SETLKW(cmd))
303 ret = v9fs_file_do_lock(filp, cmd, fl);
304 else if (IS_GETLK(cmd))
305 ret = v9fs_file_getlock(filp, fl);
312 * v9fs_file_flock_dotl - lock a file
313 * @filp: file to be locked
315 * @fl: file lock structure
319 static int v9fs_file_flock_dotl(struct file *filp, int cmd,
320 struct file_lock *fl)
322 struct inode *inode = file_inode(filp);
325 p9_debug(P9_DEBUG_VFS, "filp: %p cmd:%d lock: %p name: %pD\n",
326 filp, cmd, fl, filp);
328 if (!(fl->fl_flags & FL_FLOCK))
331 if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
332 filemap_write_and_wait(inode->i_mapping);
333 invalidate_mapping_pages(&inode->i_data, 0, -1);
335 /* Convert flock to posix lock */
336 fl->fl_flags |= FL_POSIX;
337 fl->fl_flags ^= FL_FLOCK;
339 if (IS_SETLK(cmd) | IS_SETLKW(cmd))
340 ret = v9fs_file_do_lock(filp, cmd, fl);
348 * v9fs_file_read_iter - read from a file
349 * @iocb: The operation parameters
350 * @to: The buffer to read into
354 v9fs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
356 struct p9_fid *fid = iocb->ki_filp->private_data;
359 p9_debug(P9_DEBUG_VFS, "fid %d count %zu offset %lld\n",
360 fid->fid, iov_iter_count(to), iocb->ki_pos);
362 if (!(fid->mode & P9L_DIRECT)) {
363 p9_debug(P9_DEBUG_VFS, "(cached)\n");
364 return generic_file_read_iter(iocb, to);
367 if (iocb->ki_filp->f_flags & O_NONBLOCK)
368 ret = p9_client_read_once(fid, iocb->ki_pos, to, &err);
370 ret = p9_client_read(fid, iocb->ki_pos, to, &err);
379 * v9fs_file_write_iter - write to a file
380 * @iocb: The operation parameters
381 * @from: The data to write
385 v9fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
387 struct file *file = iocb->ki_filp;
388 struct p9_fid *fid = file->private_data;
393 p9_debug(P9_DEBUG_VFS, "fid %d\n", fid->fid);
395 if (!(fid->mode & (P9L_DIRECT | P9L_NOWRITECACHE))) {
396 p9_debug(P9_DEBUG_CACHE, "(cached)\n");
397 return generic_file_write_iter(iocb, from);
400 retval = generic_write_checks(iocb, from);
404 origin = iocb->ki_pos;
405 retval = p9_client_write(file->private_data, iocb->ki_pos, from, &err);
407 struct inode *inode = file_inode(file);
409 unsigned long pg_start, pg_end;
411 pg_start = origin >> PAGE_SHIFT;
412 pg_end = (origin + retval - 1) >> PAGE_SHIFT;
413 if (inode->i_mapping && inode->i_mapping->nrpages)
414 invalidate_inode_pages2_range(inode->i_mapping,
416 iocb->ki_pos += retval;
417 i_size = i_size_read(inode);
418 if (iocb->ki_pos > i_size) {
419 inode_add_bytes(inode, iocb->ki_pos - i_size);
421 * Need to serialize against i_size_write() in
424 v9fs_i_size_write(inode, iocb->ki_pos);
431 static int v9fs_file_fsync(struct file *filp, loff_t start, loff_t end,
435 struct inode *inode = filp->f_mapping->host;
436 struct p9_wstat wstat;
439 retval = file_write_and_wait_range(filp, start, end);
444 p9_debug(P9_DEBUG_VFS, "filp %p datasync %x\n", filp, datasync);
446 fid = filp->private_data;
447 v9fs_blank_wstat(&wstat);
449 retval = p9_client_wstat(fid, &wstat);
455 int v9fs_file_fsync_dotl(struct file *filp, loff_t start, loff_t end,
459 struct inode *inode = filp->f_mapping->host;
462 retval = file_write_and_wait_range(filp, start, end);
467 p9_debug(P9_DEBUG_VFS, "filp %p datasync %x\n", filp, datasync);
469 fid = filp->private_data;
471 retval = p9_client_fsync(fid, datasync);
478 v9fs_file_mmap(struct file *filp, struct vm_area_struct *vma)
481 struct inode *inode = file_inode(filp);
482 struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
484 p9_debug(P9_DEBUG_MMAP, "filp :%p\n", filp);
486 if (!(v9ses->cache & CACHE_WRITEBACK)) {
487 p9_debug(P9_DEBUG_CACHE, "(no mmap mode)");
488 if (vma->vm_flags & VM_MAYSHARE)
490 invalidate_inode_pages2(filp->f_mapping);
491 return generic_file_readonly_mmap(filp, vma);
494 retval = generic_file_mmap(filp, vma);
496 vma->vm_ops = &v9fs_mmap_file_vm_ops;
502 v9fs_vm_page_mkwrite(struct vm_fault *vmf)
504 struct folio *folio = page_folio(vmf->page);
505 struct file *filp = vmf->vma->vm_file;
506 struct inode *inode = file_inode(filp);
509 p9_debug(P9_DEBUG_VFS, "folio %p fid %lx\n",
510 folio, (unsigned long)filp->private_data);
512 /* Wait for the page to be written to the cache before we allow it to
513 * be modified. We then assume the entire page will need writing back.
515 #ifdef CONFIG_9P_FSCACHE
516 if (folio_test_fscache(folio) &&
517 folio_wait_fscache_killable(folio) < 0)
518 return VM_FAULT_NOPAGE;
521 /* Update file times before taking page lock */
522 file_update_time(filp);
524 if (folio_lock_killable(folio) < 0)
525 return VM_FAULT_RETRY;
526 if (folio_mapping(folio) != inode->i_mapping)
528 folio_wait_stable(folio);
530 return VM_FAULT_LOCKED;
533 return VM_FAULT_NOPAGE;
536 static void v9fs_mmap_vm_close(struct vm_area_struct *vma)
540 struct writeback_control wbc = {
541 .nr_to_write = LONG_MAX,
542 .sync_mode = WB_SYNC_ALL,
543 .range_start = (loff_t)vma->vm_pgoff * PAGE_SIZE,
544 /* absolute end, byte at end included */
545 .range_end = (loff_t)vma->vm_pgoff * PAGE_SIZE +
546 (vma->vm_end - vma->vm_start - 1),
549 if (!(vma->vm_flags & VM_SHARED))
552 p9_debug(P9_DEBUG_VFS, "9p VMA close, %p, flushing", vma);
554 inode = file_inode(vma->vm_file);
555 filemap_fdatawrite_wbc(inode->i_mapping, &wbc);
558 static const struct vm_operations_struct v9fs_mmap_file_vm_ops = {
559 .close = v9fs_mmap_vm_close,
560 .fault = filemap_fault,
561 .map_pages = filemap_map_pages,
562 .page_mkwrite = v9fs_vm_page_mkwrite,
565 const struct file_operations v9fs_file_operations = {
566 .llseek = generic_file_llseek,
567 .read_iter = v9fs_file_read_iter,
568 .write_iter = v9fs_file_write_iter,
569 .open = v9fs_file_open,
570 .release = v9fs_dir_release,
571 .lock = v9fs_file_lock,
572 .mmap = generic_file_readonly_mmap,
573 .splice_read = generic_file_splice_read,
574 .splice_write = iter_file_splice_write,
575 .fsync = v9fs_file_fsync,
578 const struct file_operations v9fs_file_operations_dotl = {
579 .llseek = generic_file_llseek,
580 .read_iter = v9fs_file_read_iter,
581 .write_iter = v9fs_file_write_iter,
582 .open = v9fs_file_open,
583 .release = v9fs_dir_release,
584 .lock = v9fs_file_lock_dotl,
585 .flock = v9fs_file_flock_dotl,
586 .mmap = v9fs_file_mmap,
587 .splice_read = generic_file_splice_read,
588 .splice_write = iter_file_splice_write,
589 .fsync = v9fs_file_fsync_dotl,