xref: /openbmc/linux/fs/9p/vfs_inode_dotl.c (revision 349f631d)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  linux/fs/9p/vfs_inode_dotl.c
4  *
5  * This file contains vfs inode ops for the 9P2000.L protocol.
6  *
7  *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
8  *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
9  */
10 
11 #include <linux/module.h>
12 #include <linux/errno.h>
13 #include <linux/fs.h>
14 #include <linux/file.h>
15 #include <linux/pagemap.h>
16 #include <linux/stat.h>
17 #include <linux/string.h>
18 #include <linux/inet.h>
19 #include <linux/namei.h>
20 #include <linux/idr.h>
21 #include <linux/sched.h>
22 #include <linux/slab.h>
23 #include <linux/xattr.h>
24 #include <linux/posix_acl.h>
25 #include <net/9p/9p.h>
26 #include <net/9p/client.h>
27 
28 #include "v9fs.h"
29 #include "v9fs_vfs.h"
30 #include "fid.h"
31 #include "cache.h"
32 #include "xattr.h"
33 #include "acl.h"
34 
35 static int
36 v9fs_vfs_mknod_dotl(struct user_namespace *mnt_userns, struct inode *dir,
37 		    struct dentry *dentry, umode_t omode, dev_t rdev);
38 
39 /**
40  * v9fs_get_fsgid_for_create - Helper function to get the gid for a new object
41  * @dir_inode: The directory inode
42  *
43  * Helper function to get the gid for creating a
44  * new file system object. This checks the S_ISGID to determine the owning
45  * group of the new file system object.
46  */
47 
48 static kgid_t v9fs_get_fsgid_for_create(struct inode *dir_inode)
49 {
50 	BUG_ON(dir_inode == NULL);
51 
52 	if (dir_inode->i_mode & S_ISGID) {
53 		/* set_gid bit is set.*/
54 		return dir_inode->i_gid;
55 	}
56 	return current_fsgid();
57 }
58 
59 static int v9fs_test_inode_dotl(struct inode *inode, void *data)
60 {
61 	struct v9fs_inode *v9inode = V9FS_I(inode);
62 	struct p9_stat_dotl *st = (struct p9_stat_dotl *)data;
63 
64 	/* don't match inode of different type */
65 	if (inode_wrong_type(inode, st->st_mode))
66 		return 0;
67 
68 	if (inode->i_generation != st->st_gen)
69 		return 0;
70 
71 	/* compare qid details */
72 	if (memcmp(&v9inode->qid.version,
73 		   &st->qid.version, sizeof(v9inode->qid.version)))
74 		return 0;
75 
76 	if (v9inode->qid.type != st->qid.type)
77 		return 0;
78 
79 	if (v9inode->qid.path != st->qid.path)
80 		return 0;
81 	return 1;
82 }
83 
84 /* Always get a new inode */
85 static int v9fs_test_new_inode_dotl(struct inode *inode, void *data)
86 {
87 	return 0;
88 }
89 
90 static int v9fs_set_inode_dotl(struct inode *inode,  void *data)
91 {
92 	struct v9fs_inode *v9inode = V9FS_I(inode);
93 	struct p9_stat_dotl *st = (struct p9_stat_dotl *)data;
94 
95 	memcpy(&v9inode->qid, &st->qid, sizeof(st->qid));
96 	inode->i_generation = st->st_gen;
97 	return 0;
98 }
99 
100 static struct inode *v9fs_qid_iget_dotl(struct super_block *sb,
101 					struct p9_qid *qid,
102 					struct p9_fid *fid,
103 					struct p9_stat_dotl *st,
104 					int new)
105 {
106 	int retval;
107 	unsigned long i_ino;
108 	struct inode *inode;
109 	struct v9fs_session_info *v9ses = sb->s_fs_info;
110 	int (*test)(struct inode *, void *);
111 
112 	if (new)
113 		test = v9fs_test_new_inode_dotl;
114 	else
115 		test = v9fs_test_inode_dotl;
116 
117 	i_ino = v9fs_qid2ino(qid);
118 	inode = iget5_locked(sb, i_ino, test, v9fs_set_inode_dotl, st);
119 	if (!inode)
120 		return ERR_PTR(-ENOMEM);
121 	if (!(inode->i_state & I_NEW))
122 		return inode;
123 	/*
124 	 * initialize the inode with the stat info
125 	 * FIXME!! we may need support for stale inodes
126 	 * later.
127 	 */
128 	inode->i_ino = i_ino;
129 	retval = v9fs_init_inode(v9ses, inode,
130 				 st->st_mode, new_decode_dev(st->st_rdev));
131 	if (retval)
132 		goto error;
133 
134 	v9fs_stat2inode_dotl(st, inode, 0);
135 	v9fs_cache_inode_get_cookie(inode);
136 	retval = v9fs_get_acl(inode, fid);
137 	if (retval)
138 		goto error;
139 
140 	unlock_new_inode(inode);
141 	return inode;
142 error:
143 	iget_failed(inode);
144 	return ERR_PTR(retval);
145 
146 }
147 
148 struct inode *
149 v9fs_inode_from_fid_dotl(struct v9fs_session_info *v9ses, struct p9_fid *fid,
150 			 struct super_block *sb, int new)
151 {
152 	struct p9_stat_dotl *st;
153 	struct inode *inode = NULL;
154 
155 	st = p9_client_getattr_dotl(fid, P9_STATS_BASIC | P9_STATS_GEN);
156 	if (IS_ERR(st))
157 		return ERR_CAST(st);
158 
159 	inode = v9fs_qid_iget_dotl(sb, &st->qid, fid, st, new);
160 	kfree(st);
161 	return inode;
162 }
163 
164 struct dotl_openflag_map {
165 	int open_flag;
166 	int dotl_flag;
167 };
168 
169 static int v9fs_mapped_dotl_flags(int flags)
170 {
171 	int i;
172 	int rflags = 0;
173 	struct dotl_openflag_map dotl_oflag_map[] = {
174 		{ O_CREAT,	P9_DOTL_CREATE },
175 		{ O_EXCL,	P9_DOTL_EXCL },
176 		{ O_NOCTTY,	P9_DOTL_NOCTTY },
177 		{ O_APPEND,	P9_DOTL_APPEND },
178 		{ O_NONBLOCK,	P9_DOTL_NONBLOCK },
179 		{ O_DSYNC,	P9_DOTL_DSYNC },
180 		{ FASYNC,	P9_DOTL_FASYNC },
181 		{ O_DIRECT,	P9_DOTL_DIRECT },
182 		{ O_LARGEFILE,	P9_DOTL_LARGEFILE },
183 		{ O_DIRECTORY,	P9_DOTL_DIRECTORY },
184 		{ O_NOFOLLOW,	P9_DOTL_NOFOLLOW },
185 		{ O_NOATIME,	P9_DOTL_NOATIME },
186 		{ O_CLOEXEC,	P9_DOTL_CLOEXEC },
187 		{ O_SYNC,	P9_DOTL_SYNC},
188 	};
189 	for (i = 0; i < ARRAY_SIZE(dotl_oflag_map); i++) {
190 		if (flags & dotl_oflag_map[i].open_flag)
191 			rflags |= dotl_oflag_map[i].dotl_flag;
192 	}
193 	return rflags;
194 }
195 
196 /**
197  * v9fs_open_to_dotl_flags- convert Linux specific open flags to
198  * plan 9 open flag.
199  * @flags: flags to convert
200  */
201 int v9fs_open_to_dotl_flags(int flags)
202 {
203 	int rflags = 0;
204 
205 	/*
206 	 * We have same bits for P9_DOTL_READONLY, P9_DOTL_WRONLY
207 	 * and P9_DOTL_NOACCESS
208 	 */
209 	rflags |= flags & O_ACCMODE;
210 	rflags |= v9fs_mapped_dotl_flags(flags);
211 
212 	return rflags;
213 }
214 
215 /**
216  * v9fs_vfs_create_dotl - VFS hook to create files for 9P2000.L protocol.
217  * @mnt_userns: The user namespace of the mount
218  * @dir: directory inode that is being created
219  * @dentry:  dentry that is being deleted
220  * @omode: create permissions
221  * @excl: True if the file must not yet exist
222  *
223  */
224 static int
225 v9fs_vfs_create_dotl(struct user_namespace *mnt_userns, struct inode *dir,
226 		     struct dentry *dentry, umode_t omode, bool excl)
227 {
228 	return v9fs_vfs_mknod_dotl(mnt_userns, dir, dentry, omode, 0);
229 }
230 
231 static int
232 v9fs_vfs_atomic_open_dotl(struct inode *dir, struct dentry *dentry,
233 			  struct file *file, unsigned flags, umode_t omode)
234 {
235 	int err = 0;
236 	kgid_t gid;
237 	umode_t mode;
238 	const unsigned char *name = NULL;
239 	struct p9_qid qid;
240 	struct inode *inode;
241 	struct p9_fid *fid = NULL;
242 	struct v9fs_inode *v9inode;
243 	struct p9_fid *dfid, *ofid, *inode_fid;
244 	struct v9fs_session_info *v9ses;
245 	struct posix_acl *pacl = NULL, *dacl = NULL;
246 	struct dentry *res = NULL;
247 
248 	if (d_in_lookup(dentry)) {
249 		res = v9fs_vfs_lookup(dir, dentry, 0);
250 		if (IS_ERR(res))
251 			return PTR_ERR(res);
252 
253 		if (res)
254 			dentry = res;
255 	}
256 
257 	/* Only creates */
258 	if (!(flags & O_CREAT) || d_really_is_positive(dentry))
259 		return	finish_no_open(file, res);
260 
261 	v9ses = v9fs_inode2v9ses(dir);
262 
263 	name = dentry->d_name.name;
264 	p9_debug(P9_DEBUG_VFS, "name:%s flags:0x%x mode:0x%hx\n",
265 		 name, flags, omode);
266 
267 	dfid = v9fs_parent_fid(dentry);
268 	if (IS_ERR(dfid)) {
269 		err = PTR_ERR(dfid);
270 		p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
271 		goto out;
272 	}
273 
274 	/* clone a fid to use for creation */
275 	ofid = clone_fid(dfid);
276 	if (IS_ERR(ofid)) {
277 		err = PTR_ERR(ofid);
278 		p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
279 		goto out;
280 	}
281 
282 	gid = v9fs_get_fsgid_for_create(dir);
283 
284 	mode = omode;
285 	/* Update mode based on ACL value */
286 	err = v9fs_acl_mode(dir, &mode, &dacl, &pacl);
287 	if (err) {
288 		p9_debug(P9_DEBUG_VFS, "Failed to get acl values in creat %d\n",
289 			 err);
290 		goto error;
291 	}
292 	err = p9_client_create_dotl(ofid, name, v9fs_open_to_dotl_flags(flags),
293 				    mode, gid, &qid);
294 	if (err < 0) {
295 		p9_debug(P9_DEBUG_VFS, "p9_client_open_dotl failed in creat %d\n",
296 			 err);
297 		goto error;
298 	}
299 	v9fs_invalidate_inode_attr(dir);
300 
301 	/* instantiate inode and assign the unopened fid to the dentry */
302 	fid = p9_client_walk(dfid, 1, &name, 1);
303 	p9_client_clunk(dfid);
304 	if (IS_ERR(fid)) {
305 		err = PTR_ERR(fid);
306 		p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
307 		fid = NULL;
308 		goto error;
309 	}
310 	inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
311 	if (IS_ERR(inode)) {
312 		err = PTR_ERR(inode);
313 		p9_debug(P9_DEBUG_VFS, "inode creation failed %d\n", err);
314 		goto error;
315 	}
316 	/* Now set the ACL based on the default value */
317 	v9fs_set_create_acl(inode, fid, dacl, pacl);
318 
319 	v9fs_fid_add(dentry, fid);
320 	d_instantiate(dentry, inode);
321 
322 	v9inode = V9FS_I(inode);
323 	mutex_lock(&v9inode->v_mutex);
324 	if ((v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) &&
325 	    !v9inode->writeback_fid &&
326 	    ((flags & O_ACCMODE) != O_RDONLY)) {
327 		/*
328 		 * clone a fid and add it to writeback_fid
329 		 * we do it during open time instead of
330 		 * page dirty time via write_begin/page_mkwrite
331 		 * because we want write after unlink usecase
332 		 * to work.
333 		 */
334 		inode_fid = v9fs_writeback_fid(dentry);
335 		if (IS_ERR(inode_fid)) {
336 			err = PTR_ERR(inode_fid);
337 			mutex_unlock(&v9inode->v_mutex);
338 			goto err_clunk_old_fid;
339 		}
340 		v9inode->writeback_fid = (void *) inode_fid;
341 	}
342 	mutex_unlock(&v9inode->v_mutex);
343 	/* Since we are opening a file, assign the open fid to the file */
344 	err = finish_open(file, dentry, generic_file_open);
345 	if (err)
346 		goto err_clunk_old_fid;
347 	file->private_data = ofid;
348 	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
349 		v9fs_cache_inode_set_cookie(inode, file);
350 	v9fs_open_fid_add(inode, ofid);
351 	file->f_mode |= FMODE_CREATED;
352 out:
353 	v9fs_put_acl(dacl, pacl);
354 	dput(res);
355 	return err;
356 
357 error:
358 	if (fid)
359 		p9_client_clunk(fid);
360 err_clunk_old_fid:
361 	if (ofid)
362 		p9_client_clunk(ofid);
363 	goto out;
364 }
365 
366 /**
367  * v9fs_vfs_mkdir_dotl - VFS mkdir hook to create a directory
368  * @mnt_userns: The user namespace of the mount
369  * @dir:  inode that is being unlinked
370  * @dentry: dentry that is being unlinked
371  * @omode: mode for new directory
372  *
373  */
374 
375 static int v9fs_vfs_mkdir_dotl(struct user_namespace *mnt_userns,
376 			       struct inode *dir, struct dentry *dentry,
377 			       umode_t omode)
378 {
379 	int err;
380 	struct v9fs_session_info *v9ses;
381 	struct p9_fid *fid = NULL, *dfid = NULL;
382 	kgid_t gid;
383 	const unsigned char *name;
384 	umode_t mode;
385 	struct inode *inode;
386 	struct p9_qid qid;
387 	struct posix_acl *dacl = NULL, *pacl = NULL;
388 
389 	p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry);
390 	err = 0;
391 	v9ses = v9fs_inode2v9ses(dir);
392 
393 	omode |= S_IFDIR;
394 	if (dir->i_mode & S_ISGID)
395 		omode |= S_ISGID;
396 
397 	dfid = v9fs_parent_fid(dentry);
398 	if (IS_ERR(dfid)) {
399 		err = PTR_ERR(dfid);
400 		p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
401 		dfid = NULL;
402 		goto error;
403 	}
404 
405 	gid = v9fs_get_fsgid_for_create(dir);
406 	mode = omode;
407 	/* Update mode based on ACL value */
408 	err = v9fs_acl_mode(dir, &mode, &dacl, &pacl);
409 	if (err) {
410 		p9_debug(P9_DEBUG_VFS, "Failed to get acl values in mkdir %d\n",
411 			 err);
412 		goto error;
413 	}
414 	name = dentry->d_name.name;
415 	err = p9_client_mkdir_dotl(dfid, name, mode, gid, &qid);
416 	if (err < 0)
417 		goto error;
418 	fid = p9_client_walk(dfid, 1, &name, 1);
419 	if (IS_ERR(fid)) {
420 		err = PTR_ERR(fid);
421 		p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n",
422 			 err);
423 		fid = NULL;
424 		goto error;
425 	}
426 
427 	/* instantiate inode and assign the unopened fid to the dentry */
428 	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
429 		inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
430 		if (IS_ERR(inode)) {
431 			err = PTR_ERR(inode);
432 			p9_debug(P9_DEBUG_VFS, "inode creation failed %d\n",
433 				 err);
434 			goto error;
435 		}
436 		v9fs_fid_add(dentry, fid);
437 		v9fs_set_create_acl(inode, fid, dacl, pacl);
438 		d_instantiate(dentry, inode);
439 		fid = NULL;
440 		err = 0;
441 	} else {
442 		/*
443 		 * Not in cached mode. No need to populate
444 		 * inode with stat. We need to get an inode
445 		 * so that we can set the acl with dentry
446 		 */
447 		inode = v9fs_get_inode(dir->i_sb, mode, 0);
448 		if (IS_ERR(inode)) {
449 			err = PTR_ERR(inode);
450 			goto error;
451 		}
452 		v9fs_set_create_acl(inode, fid, dacl, pacl);
453 		d_instantiate(dentry, inode);
454 	}
455 	inc_nlink(dir);
456 	v9fs_invalidate_inode_attr(dir);
457 error:
458 	if (fid)
459 		p9_client_clunk(fid);
460 	v9fs_put_acl(dacl, pacl);
461 	p9_client_clunk(dfid);
462 	return err;
463 }
464 
465 static int
466 v9fs_vfs_getattr_dotl(struct user_namespace *mnt_userns,
467 		      const struct path *path, struct kstat *stat,
468 		      u32 request_mask, unsigned int flags)
469 {
470 	struct dentry *dentry = path->dentry;
471 	struct v9fs_session_info *v9ses;
472 	struct p9_fid *fid;
473 	struct p9_stat_dotl *st;
474 
475 	p9_debug(P9_DEBUG_VFS, "dentry: %p\n", dentry);
476 	v9ses = v9fs_dentry2v9ses(dentry);
477 	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
478 		generic_fillattr(&init_user_ns, d_inode(dentry), stat);
479 		return 0;
480 	}
481 	fid = v9fs_fid_lookup(dentry);
482 	if (IS_ERR(fid))
483 		return PTR_ERR(fid);
484 
485 	/* Ask for all the fields in stat structure. Server will return
486 	 * whatever it supports
487 	 */
488 
489 	st = p9_client_getattr_dotl(fid, P9_STATS_ALL);
490 	p9_client_clunk(fid);
491 	if (IS_ERR(st))
492 		return PTR_ERR(st);
493 
494 	v9fs_stat2inode_dotl(st, d_inode(dentry), 0);
495 	generic_fillattr(&init_user_ns, d_inode(dentry), stat);
496 	/* Change block size to what the server returned */
497 	stat->blksize = st->st_blksize;
498 
499 	kfree(st);
500 	return 0;
501 }
502 
503 /*
504  * Attribute flags.
505  */
506 #define P9_ATTR_MODE		(1 << 0)
507 #define P9_ATTR_UID		(1 << 1)
508 #define P9_ATTR_GID		(1 << 2)
509 #define P9_ATTR_SIZE		(1 << 3)
510 #define P9_ATTR_ATIME		(1 << 4)
511 #define P9_ATTR_MTIME		(1 << 5)
512 #define P9_ATTR_CTIME		(1 << 6)
513 #define P9_ATTR_ATIME_SET	(1 << 7)
514 #define P9_ATTR_MTIME_SET	(1 << 8)
515 
516 struct dotl_iattr_map {
517 	int iattr_valid;
518 	int p9_iattr_valid;
519 };
520 
521 static int v9fs_mapped_iattr_valid(int iattr_valid)
522 {
523 	int i;
524 	int p9_iattr_valid = 0;
525 	struct dotl_iattr_map dotl_iattr_map[] = {
526 		{ ATTR_MODE,		P9_ATTR_MODE },
527 		{ ATTR_UID,		P9_ATTR_UID },
528 		{ ATTR_GID,		P9_ATTR_GID },
529 		{ ATTR_SIZE,		P9_ATTR_SIZE },
530 		{ ATTR_ATIME,		P9_ATTR_ATIME },
531 		{ ATTR_MTIME,		P9_ATTR_MTIME },
532 		{ ATTR_CTIME,		P9_ATTR_CTIME },
533 		{ ATTR_ATIME_SET,	P9_ATTR_ATIME_SET },
534 		{ ATTR_MTIME_SET,	P9_ATTR_MTIME_SET },
535 	};
536 	for (i = 0; i < ARRAY_SIZE(dotl_iattr_map); i++) {
537 		if (iattr_valid & dotl_iattr_map[i].iattr_valid)
538 			p9_iattr_valid |= dotl_iattr_map[i].p9_iattr_valid;
539 	}
540 	return p9_iattr_valid;
541 }
542 
543 /**
544  * v9fs_vfs_setattr_dotl - set file metadata
545  * @mnt_userns: The user namespace of the mount
546  * @dentry: file whose metadata to set
547  * @iattr: metadata assignment structure
548  *
549  */
550 
551 int v9fs_vfs_setattr_dotl(struct user_namespace *mnt_userns,
552 			  struct dentry *dentry, struct iattr *iattr)
553 {
554 	int retval, use_dentry = 0;
555 	struct p9_fid *fid = NULL;
556 	struct p9_iattr_dotl p9attr;
557 	struct inode *inode = d_inode(dentry);
558 
559 	p9_debug(P9_DEBUG_VFS, "\n");
560 
561 	retval = setattr_prepare(&init_user_ns, dentry, iattr);
562 	if (retval)
563 		return retval;
564 
565 	p9attr.valid = v9fs_mapped_iattr_valid(iattr->ia_valid);
566 	p9attr.mode = iattr->ia_mode;
567 	p9attr.uid = iattr->ia_uid;
568 	p9attr.gid = iattr->ia_gid;
569 	p9attr.size = iattr->ia_size;
570 	p9attr.atime_sec = iattr->ia_atime.tv_sec;
571 	p9attr.atime_nsec = iattr->ia_atime.tv_nsec;
572 	p9attr.mtime_sec = iattr->ia_mtime.tv_sec;
573 	p9attr.mtime_nsec = iattr->ia_mtime.tv_nsec;
574 
575 	if (iattr->ia_valid & ATTR_FILE) {
576 		fid = iattr->ia_file->private_data;
577 		WARN_ON(!fid);
578 	}
579 	if (!fid) {
580 		fid = v9fs_fid_lookup(dentry);
581 		use_dentry = 1;
582 	}
583 	if (IS_ERR(fid))
584 		return PTR_ERR(fid);
585 
586 	/* Write all dirty data */
587 	if (S_ISREG(inode->i_mode))
588 		filemap_write_and_wait(inode->i_mapping);
589 
590 	retval = p9_client_setattr(fid, &p9attr);
591 	if (retval < 0) {
592 		if (use_dentry)
593 			p9_client_clunk(fid);
594 		return retval;
595 	}
596 
597 	if ((iattr->ia_valid & ATTR_SIZE) &&
598 	    iattr->ia_size != i_size_read(inode))
599 		truncate_setsize(inode, iattr->ia_size);
600 
601 	v9fs_invalidate_inode_attr(inode);
602 	setattr_copy(&init_user_ns, inode, iattr);
603 	mark_inode_dirty(inode);
604 	if (iattr->ia_valid & ATTR_MODE) {
605 		/* We also want to update ACL when we update mode bits */
606 		retval = v9fs_acl_chmod(inode, fid);
607 		if (retval < 0) {
608 			if (use_dentry)
609 				p9_client_clunk(fid);
610 			return retval;
611 		}
612 	}
613 	if (use_dentry)
614 		p9_client_clunk(fid);
615 
616 	return 0;
617 }
618 
619 /**
620  * v9fs_stat2inode_dotl - populate an inode structure with stat info
621  * @stat: stat structure
622  * @inode: inode to populate
623  * @flags: ctrl flags (e.g. V9FS_STAT2INODE_KEEP_ISIZE)
624  *
625  */
626 
627 void
628 v9fs_stat2inode_dotl(struct p9_stat_dotl *stat, struct inode *inode,
629 		      unsigned int flags)
630 {
631 	umode_t mode;
632 	struct v9fs_inode *v9inode = V9FS_I(inode);
633 
634 	if ((stat->st_result_mask & P9_STATS_BASIC) == P9_STATS_BASIC) {
635 		inode->i_atime.tv_sec = stat->st_atime_sec;
636 		inode->i_atime.tv_nsec = stat->st_atime_nsec;
637 		inode->i_mtime.tv_sec = stat->st_mtime_sec;
638 		inode->i_mtime.tv_nsec = stat->st_mtime_nsec;
639 		inode->i_ctime.tv_sec = stat->st_ctime_sec;
640 		inode->i_ctime.tv_nsec = stat->st_ctime_nsec;
641 		inode->i_uid = stat->st_uid;
642 		inode->i_gid = stat->st_gid;
643 		set_nlink(inode, stat->st_nlink);
644 
645 		mode = stat->st_mode & S_IALLUGO;
646 		mode |= inode->i_mode & ~S_IALLUGO;
647 		inode->i_mode = mode;
648 
649 		if (!(flags & V9FS_STAT2INODE_KEEP_ISIZE))
650 			v9fs_i_size_write(inode, stat->st_size);
651 		inode->i_blocks = stat->st_blocks;
652 	} else {
653 		if (stat->st_result_mask & P9_STATS_ATIME) {
654 			inode->i_atime.tv_sec = stat->st_atime_sec;
655 			inode->i_atime.tv_nsec = stat->st_atime_nsec;
656 		}
657 		if (stat->st_result_mask & P9_STATS_MTIME) {
658 			inode->i_mtime.tv_sec = stat->st_mtime_sec;
659 			inode->i_mtime.tv_nsec = stat->st_mtime_nsec;
660 		}
661 		if (stat->st_result_mask & P9_STATS_CTIME) {
662 			inode->i_ctime.tv_sec = stat->st_ctime_sec;
663 			inode->i_ctime.tv_nsec = stat->st_ctime_nsec;
664 		}
665 		if (stat->st_result_mask & P9_STATS_UID)
666 			inode->i_uid = stat->st_uid;
667 		if (stat->st_result_mask & P9_STATS_GID)
668 			inode->i_gid = stat->st_gid;
669 		if (stat->st_result_mask & P9_STATS_NLINK)
670 			set_nlink(inode, stat->st_nlink);
671 		if (stat->st_result_mask & P9_STATS_MODE) {
672 			mode = stat->st_mode & S_IALLUGO;
673 			mode |= inode->i_mode & ~S_IALLUGO;
674 			inode->i_mode = mode;
675 		}
676 		if (!(flags & V9FS_STAT2INODE_KEEP_ISIZE) &&
677 		    stat->st_result_mask & P9_STATS_SIZE)
678 			v9fs_i_size_write(inode, stat->st_size);
679 		if (stat->st_result_mask & P9_STATS_BLOCKS)
680 			inode->i_blocks = stat->st_blocks;
681 	}
682 	if (stat->st_result_mask & P9_STATS_GEN)
683 		inode->i_generation = stat->st_gen;
684 
685 	/* Currently we don't support P9_STATS_BTIME and P9_STATS_DATA_VERSION
686 	 * because the inode structure does not have fields for them.
687 	 */
688 	v9inode->cache_validity &= ~V9FS_INO_INVALID_ATTR;
689 }
690 
691 static int
692 v9fs_vfs_symlink_dotl(struct user_namespace *mnt_userns, struct inode *dir,
693 		      struct dentry *dentry, const char *symname)
694 {
695 	int err;
696 	kgid_t gid;
697 	const unsigned char *name;
698 	struct p9_qid qid;
699 	struct inode *inode;
700 	struct p9_fid *dfid;
701 	struct p9_fid *fid = NULL;
702 	struct v9fs_session_info *v9ses;
703 
704 	name = dentry->d_name.name;
705 	p9_debug(P9_DEBUG_VFS, "%lu,%s,%s\n", dir->i_ino, name, symname);
706 	v9ses = v9fs_inode2v9ses(dir);
707 
708 	dfid = v9fs_parent_fid(dentry);
709 	if (IS_ERR(dfid)) {
710 		err = PTR_ERR(dfid);
711 		p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
712 		return err;
713 	}
714 
715 	gid = v9fs_get_fsgid_for_create(dir);
716 
717 	/* Server doesn't alter fid on TSYMLINK. Hence no need to clone it. */
718 	err = p9_client_symlink(dfid, name, symname, gid, &qid);
719 
720 	if (err < 0) {
721 		p9_debug(P9_DEBUG_VFS, "p9_client_symlink failed %d\n", err);
722 		goto error;
723 	}
724 
725 	v9fs_invalidate_inode_attr(dir);
726 	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
727 		/* Now walk from the parent so we can get an unopened fid. */
728 		fid = p9_client_walk(dfid, 1, &name, 1);
729 		if (IS_ERR(fid)) {
730 			err = PTR_ERR(fid);
731 			p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n",
732 				 err);
733 			fid = NULL;
734 			goto error;
735 		}
736 
737 		/* instantiate inode and assign the unopened fid to dentry */
738 		inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
739 		if (IS_ERR(inode)) {
740 			err = PTR_ERR(inode);
741 			p9_debug(P9_DEBUG_VFS, "inode creation failed %d\n",
742 				 err);
743 			goto error;
744 		}
745 		v9fs_fid_add(dentry, fid);
746 		d_instantiate(dentry, inode);
747 		fid = NULL;
748 		err = 0;
749 	} else {
750 		/* Not in cached mode. No need to populate inode with stat */
751 		inode = v9fs_get_inode(dir->i_sb, S_IFLNK, 0);
752 		if (IS_ERR(inode)) {
753 			err = PTR_ERR(inode);
754 			goto error;
755 		}
756 		d_instantiate(dentry, inode);
757 	}
758 
759 error:
760 	if (fid)
761 		p9_client_clunk(fid);
762 
763 	p9_client_clunk(dfid);
764 	return err;
765 }
766 
767 /**
768  * v9fs_vfs_link_dotl - create a hardlink for dotl
769  * @old_dentry: dentry for file to link to
770  * @dir: inode destination for new link
771  * @dentry: dentry for link
772  *
773  */
774 
775 static int
776 v9fs_vfs_link_dotl(struct dentry *old_dentry, struct inode *dir,
777 		struct dentry *dentry)
778 {
779 	int err;
780 	struct p9_fid *dfid, *oldfid;
781 	struct v9fs_session_info *v9ses;
782 
783 	p9_debug(P9_DEBUG_VFS, "dir ino: %lu, old_name: %pd, new_name: %pd\n",
784 		 dir->i_ino, old_dentry, dentry);
785 
786 	v9ses = v9fs_inode2v9ses(dir);
787 	dfid = v9fs_parent_fid(dentry);
788 	if (IS_ERR(dfid))
789 		return PTR_ERR(dfid);
790 
791 	oldfid = v9fs_fid_lookup(old_dentry);
792 	if (IS_ERR(oldfid)) {
793 		p9_client_clunk(dfid);
794 		return PTR_ERR(oldfid);
795 	}
796 
797 	err = p9_client_link(dfid, oldfid, dentry->d_name.name);
798 
799 	p9_client_clunk(dfid);
800 	p9_client_clunk(oldfid);
801 	if (err < 0) {
802 		p9_debug(P9_DEBUG_VFS, "p9_client_link failed %d\n", err);
803 		return err;
804 	}
805 
806 	v9fs_invalidate_inode_attr(dir);
807 	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
808 		/* Get the latest stat info from server. */
809 		struct p9_fid *fid;
810 		fid = v9fs_fid_lookup(old_dentry);
811 		if (IS_ERR(fid))
812 			return PTR_ERR(fid);
813 
814 		v9fs_refresh_inode_dotl(fid, d_inode(old_dentry));
815 		p9_client_clunk(fid);
816 	}
817 	ihold(d_inode(old_dentry));
818 	d_instantiate(dentry, d_inode(old_dentry));
819 
820 	return err;
821 }
822 
823 /**
824  * v9fs_vfs_mknod_dotl - create a special file
825  * @mnt_userns: The user namespace of the mount
826  * @dir: inode destination for new link
827  * @dentry: dentry for file
828  * @omode: mode for creation
829  * @rdev: device associated with special file
830  *
831  */
832 static int
833 v9fs_vfs_mknod_dotl(struct user_namespace *mnt_userns, struct inode *dir,
834 		    struct dentry *dentry, umode_t omode, dev_t rdev)
835 {
836 	int err;
837 	kgid_t gid;
838 	const unsigned char *name;
839 	umode_t mode;
840 	struct v9fs_session_info *v9ses;
841 	struct p9_fid *fid = NULL, *dfid = NULL;
842 	struct inode *inode;
843 	struct p9_qid qid;
844 	struct posix_acl *dacl = NULL, *pacl = NULL;
845 
846 	p9_debug(P9_DEBUG_VFS, " %lu,%pd mode: %hx MAJOR: %u MINOR: %u\n",
847 		 dir->i_ino, dentry, omode,
848 		 MAJOR(rdev), MINOR(rdev));
849 
850 	v9ses = v9fs_inode2v9ses(dir);
851 	dfid = v9fs_parent_fid(dentry);
852 	if (IS_ERR(dfid)) {
853 		err = PTR_ERR(dfid);
854 		p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
855 		dfid = NULL;
856 		goto error;
857 	}
858 
859 	gid = v9fs_get_fsgid_for_create(dir);
860 	mode = omode;
861 	/* Update mode based on ACL value */
862 	err = v9fs_acl_mode(dir, &mode, &dacl, &pacl);
863 	if (err) {
864 		p9_debug(P9_DEBUG_VFS, "Failed to get acl values in mknod %d\n",
865 			 err);
866 		goto error;
867 	}
868 	name = dentry->d_name.name;
869 
870 	err = p9_client_mknod_dotl(dfid, name, mode, rdev, gid, &qid);
871 	if (err < 0)
872 		goto error;
873 
874 	v9fs_invalidate_inode_attr(dir);
875 	fid = p9_client_walk(dfid, 1, &name, 1);
876 	if (IS_ERR(fid)) {
877 		err = PTR_ERR(fid);
878 		p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n",
879 			 err);
880 		fid = NULL;
881 		goto error;
882 	}
883 
884 	/* instantiate inode and assign the unopened fid to the dentry */
885 	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
886 		inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
887 		if (IS_ERR(inode)) {
888 			err = PTR_ERR(inode);
889 			p9_debug(P9_DEBUG_VFS, "inode creation failed %d\n",
890 				 err);
891 			goto error;
892 		}
893 		v9fs_set_create_acl(inode, fid, dacl, pacl);
894 		v9fs_fid_add(dentry, fid);
895 		d_instantiate(dentry, inode);
896 		fid = NULL;
897 		err = 0;
898 	} else {
899 		/*
900 		 * Not in cached mode. No need to populate inode with stat.
901 		 * socket syscall returns a fd, so we need instantiate
902 		 */
903 		inode = v9fs_get_inode(dir->i_sb, mode, rdev);
904 		if (IS_ERR(inode)) {
905 			err = PTR_ERR(inode);
906 			goto error;
907 		}
908 		v9fs_set_create_acl(inode, fid, dacl, pacl);
909 		d_instantiate(dentry, inode);
910 	}
911 error:
912 	if (fid)
913 		p9_client_clunk(fid);
914 	v9fs_put_acl(dacl, pacl);
915 	p9_client_clunk(dfid);
916 
917 	return err;
918 }
919 
920 /**
921  * v9fs_vfs_get_link_dotl - follow a symlink path
922  * @dentry: dentry for symlink
923  * @inode: inode for symlink
924  * @done: destructor for return value
925  */
926 
927 static const char *
928 v9fs_vfs_get_link_dotl(struct dentry *dentry,
929 		       struct inode *inode,
930 		       struct delayed_call *done)
931 {
932 	struct p9_fid *fid;
933 	char *target;
934 	int retval;
935 
936 	if (!dentry)
937 		return ERR_PTR(-ECHILD);
938 
939 	p9_debug(P9_DEBUG_VFS, "%pd\n", dentry);
940 
941 	fid = v9fs_fid_lookup(dentry);
942 	if (IS_ERR(fid))
943 		return ERR_CAST(fid);
944 	retval = p9_client_readlink(fid, &target);
945 	p9_client_clunk(fid);
946 	if (retval)
947 		return ERR_PTR(retval);
948 	set_delayed_call(done, kfree_link, target);
949 	return target;
950 }
951 
952 int v9fs_refresh_inode_dotl(struct p9_fid *fid, struct inode *inode)
953 {
954 	struct p9_stat_dotl *st;
955 	struct v9fs_session_info *v9ses;
956 	unsigned int flags;
957 
958 	v9ses = v9fs_inode2v9ses(inode);
959 	st = p9_client_getattr_dotl(fid, P9_STATS_ALL);
960 	if (IS_ERR(st))
961 		return PTR_ERR(st);
962 	/*
963 	 * Don't update inode if the file type is different
964 	 */
965 	if (inode_wrong_type(inode, st->st_mode))
966 		goto out;
967 
968 	/*
969 	 * We don't want to refresh inode->i_size,
970 	 * because we may have cached data
971 	 */
972 	flags = (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) ?
973 		V9FS_STAT2INODE_KEEP_ISIZE : 0;
974 	v9fs_stat2inode_dotl(st, inode, flags);
975 out:
976 	kfree(st);
977 	return 0;
978 }
979 
980 const struct inode_operations v9fs_dir_inode_operations_dotl = {
981 	.create = v9fs_vfs_create_dotl,
982 	.atomic_open = v9fs_vfs_atomic_open_dotl,
983 	.lookup = v9fs_vfs_lookup,
984 	.link = v9fs_vfs_link_dotl,
985 	.symlink = v9fs_vfs_symlink_dotl,
986 	.unlink = v9fs_vfs_unlink,
987 	.mkdir = v9fs_vfs_mkdir_dotl,
988 	.rmdir = v9fs_vfs_rmdir,
989 	.mknod = v9fs_vfs_mknod_dotl,
990 	.rename = v9fs_vfs_rename,
991 	.getattr = v9fs_vfs_getattr_dotl,
992 	.setattr = v9fs_vfs_setattr_dotl,
993 	.listxattr = v9fs_listxattr,
994 	.get_acl = v9fs_iop_get_acl,
995 };
996 
997 const struct inode_operations v9fs_file_inode_operations_dotl = {
998 	.getattr = v9fs_vfs_getattr_dotl,
999 	.setattr = v9fs_vfs_setattr_dotl,
1000 	.listxattr = v9fs_listxattr,
1001 	.get_acl = v9fs_iop_get_acl,
1002 };
1003 
1004 const struct inode_operations v9fs_symlink_inode_operations_dotl = {
1005 	.get_link = v9fs_vfs_get_link_dotl,
1006 	.getattr = v9fs_vfs_getattr_dotl,
1007 	.setattr = v9fs_vfs_setattr_dotl,
1008 	.listxattr = v9fs_listxattr,
1009 };
1010