xref: /linux/fs/9p/vfs_inode_dotl.c (revision ea8a163e02d6925773129e2dd86e419e491b791d)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * This file contains vfs inode ops for the 9P2000.L protocol.
4  *
5  *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
6  *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
7  */
8 
9 #include <linux/module.h>
10 #include <linux/errno.h>
11 #include <linux/fs.h>
12 #include <linux/file.h>
13 #include <linux/pagemap.h>
14 #include <linux/stat.h>
15 #include <linux/string.h>
16 #include <linux/inet.h>
17 #include <linux/namei.h>
18 #include <linux/idr.h>
19 #include <linux/sched.h>
20 #include <linux/slab.h>
21 #include <linux/xattr.h>
22 #include <linux/posix_acl.h>
23 #include <net/9p/9p.h>
24 #include <net/9p/client.h>
25 
26 #include "v9fs.h"
27 #include "v9fs_vfs.h"
28 #include "fid.h"
29 #include "cache.h"
30 #include "xattr.h"
31 #include "acl.h"
32 
33 static int
34 v9fs_vfs_mknod_dotl(struct user_namespace *mnt_userns, struct inode *dir,
35 		    struct dentry *dentry, umode_t omode, dev_t rdev);
36 
37 /**
38  * v9fs_get_fsgid_for_create - Helper function to get the gid for a new object
39  * @dir_inode: The directory inode
40  *
41  * Helper function to get the gid for creating a
42  * new file system object. This checks the S_ISGID to determine the owning
43  * group of the new file system object.
44  */
45 
46 static kgid_t v9fs_get_fsgid_for_create(struct inode *dir_inode)
47 {
48 	BUG_ON(dir_inode == NULL);
49 
50 	if (dir_inode->i_mode & S_ISGID) {
51 		/* set_gid bit is set.*/
52 		return dir_inode->i_gid;
53 	}
54 	return current_fsgid();
55 }
56 
57 static int v9fs_test_inode_dotl(struct inode *inode, void *data)
58 {
59 	struct v9fs_inode *v9inode = V9FS_I(inode);
60 	struct p9_stat_dotl *st = (struct p9_stat_dotl *)data;
61 
62 	/* don't match inode of different type */
63 	if (inode_wrong_type(inode, st->st_mode))
64 		return 0;
65 
66 	if (inode->i_generation != st->st_gen)
67 		return 0;
68 
69 	/* compare qid details */
70 	if (memcmp(&v9inode->qid.version,
71 		   &st->qid.version, sizeof(v9inode->qid.version)))
72 		return 0;
73 
74 	if (v9inode->qid.type != st->qid.type)
75 		return 0;
76 
77 	if (v9inode->qid.path != st->qid.path)
78 		return 0;
79 	return 1;
80 }
81 
82 /* Always get a new inode */
83 static int v9fs_test_new_inode_dotl(struct inode *inode, void *data)
84 {
85 	return 0;
86 }
87 
88 static int v9fs_set_inode_dotl(struct inode *inode,  void *data)
89 {
90 	struct v9fs_inode *v9inode = V9FS_I(inode);
91 	struct p9_stat_dotl *st = (struct p9_stat_dotl *)data;
92 
93 	memcpy(&v9inode->qid, &st->qid, sizeof(st->qid));
94 	inode->i_generation = st->st_gen;
95 	return 0;
96 }
97 
98 static struct inode *v9fs_qid_iget_dotl(struct super_block *sb,
99 					struct p9_qid *qid,
100 					struct p9_fid *fid,
101 					struct p9_stat_dotl *st,
102 					int new)
103 {
104 	int retval;
105 	unsigned long i_ino;
106 	struct inode *inode;
107 	struct v9fs_session_info *v9ses = sb->s_fs_info;
108 	int (*test)(struct inode *inode, void *data);
109 
110 	if (new)
111 		test = v9fs_test_new_inode_dotl;
112 	else
113 		test = v9fs_test_inode_dotl;
114 
115 	i_ino = v9fs_qid2ino(qid);
116 	inode = iget5_locked(sb, i_ino, test, v9fs_set_inode_dotl, st);
117 	if (!inode)
118 		return ERR_PTR(-ENOMEM);
119 	if (!(inode->i_state & I_NEW))
120 		return inode;
121 	/*
122 	 * initialize the inode with the stat info
123 	 * FIXME!! we may need support for stale inodes
124 	 * later.
125 	 */
126 	inode->i_ino = i_ino;
127 	retval = v9fs_init_inode(v9ses, inode,
128 				 st->st_mode, new_decode_dev(st->st_rdev));
129 	if (retval)
130 		goto error;
131 
132 	v9fs_stat2inode_dotl(st, inode, 0);
133 	v9fs_cache_inode_get_cookie(inode);
134 	retval = v9fs_get_acl(inode, fid);
135 	if (retval)
136 		goto error;
137 
138 	unlock_new_inode(inode);
139 	return inode;
140 error:
141 	iget_failed(inode);
142 	return ERR_PTR(retval);
143 
144 }
145 
146 struct inode *
147 v9fs_inode_from_fid_dotl(struct v9fs_session_info *v9ses, struct p9_fid *fid,
148 			 struct super_block *sb, int new)
149 {
150 	struct p9_stat_dotl *st;
151 	struct inode *inode = NULL;
152 
153 	st = p9_client_getattr_dotl(fid, P9_STATS_BASIC | P9_STATS_GEN);
154 	if (IS_ERR(st))
155 		return ERR_CAST(st);
156 
157 	inode = v9fs_qid_iget_dotl(sb, &st->qid, fid, st, new);
158 	kfree(st);
159 	return inode;
160 }
161 
162 struct dotl_openflag_map {
163 	int open_flag;
164 	int dotl_flag;
165 };
166 
167 static int v9fs_mapped_dotl_flags(int flags)
168 {
169 	int i;
170 	int rflags = 0;
171 	struct dotl_openflag_map dotl_oflag_map[] = {
172 		{ O_CREAT,	P9_DOTL_CREATE },
173 		{ O_EXCL,	P9_DOTL_EXCL },
174 		{ O_NOCTTY,	P9_DOTL_NOCTTY },
175 		{ O_APPEND,	P9_DOTL_APPEND },
176 		{ O_NONBLOCK,	P9_DOTL_NONBLOCK },
177 		{ O_DSYNC,	P9_DOTL_DSYNC },
178 		{ FASYNC,	P9_DOTL_FASYNC },
179 		{ O_DIRECT,	P9_DOTL_DIRECT },
180 		{ O_LARGEFILE,	P9_DOTL_LARGEFILE },
181 		{ O_DIRECTORY,	P9_DOTL_DIRECTORY },
182 		{ O_NOFOLLOW,	P9_DOTL_NOFOLLOW },
183 		{ O_NOATIME,	P9_DOTL_NOATIME },
184 		{ O_CLOEXEC,	P9_DOTL_CLOEXEC },
185 		{ O_SYNC,	P9_DOTL_SYNC},
186 	};
187 	for (i = 0; i < ARRAY_SIZE(dotl_oflag_map); i++) {
188 		if (flags & dotl_oflag_map[i].open_flag)
189 			rflags |= dotl_oflag_map[i].dotl_flag;
190 	}
191 	return rflags;
192 }
193 
194 /**
195  * v9fs_open_to_dotl_flags- convert Linux specific open flags to
196  * plan 9 open flag.
197  * @flags: flags to convert
198  */
199 int v9fs_open_to_dotl_flags(int flags)
200 {
201 	int rflags = 0;
202 
203 	/*
204 	 * We have same bits for P9_DOTL_READONLY, P9_DOTL_WRONLY
205 	 * and P9_DOTL_NOACCESS
206 	 */
207 	rflags |= flags & O_ACCMODE;
208 	rflags |= v9fs_mapped_dotl_flags(flags);
209 
210 	return rflags;
211 }
212 
213 /**
214  * v9fs_vfs_create_dotl - VFS hook to create files for 9P2000.L protocol.
215  * @mnt_userns: The user namespace of the mount
216  * @dir: directory inode that is being created
217  * @dentry:  dentry that is being deleted
218  * @omode: create permissions
219  * @excl: True if the file must not yet exist
220  *
221  */
222 static int
223 v9fs_vfs_create_dotl(struct user_namespace *mnt_userns, struct inode *dir,
224 		     struct dentry *dentry, umode_t omode, bool excl)
225 {
226 	return v9fs_vfs_mknod_dotl(mnt_userns, dir, dentry, omode, 0);
227 }
228 
229 static int
230 v9fs_vfs_atomic_open_dotl(struct inode *dir, struct dentry *dentry,
231 			  struct file *file, unsigned int flags, umode_t omode)
232 {
233 	int err = 0;
234 	kgid_t gid;
235 	umode_t mode;
236 	const unsigned char *name = NULL;
237 	struct p9_qid qid;
238 	struct inode *inode;
239 	struct p9_fid *fid = NULL;
240 	struct v9fs_inode *v9inode;
241 	struct p9_fid *dfid, *ofid, *inode_fid;
242 	struct v9fs_session_info *v9ses;
243 	struct posix_acl *pacl = NULL, *dacl = NULL;
244 	struct dentry *res = NULL;
245 
246 	if (d_in_lookup(dentry)) {
247 		res = v9fs_vfs_lookup(dir, dentry, 0);
248 		if (IS_ERR(res))
249 			return PTR_ERR(res);
250 
251 		if (res)
252 			dentry = res;
253 	}
254 
255 	/* Only creates */
256 	if (!(flags & O_CREAT) || d_really_is_positive(dentry))
257 		return	finish_no_open(file, res);
258 
259 	v9ses = v9fs_inode2v9ses(dir);
260 
261 	name = dentry->d_name.name;
262 	p9_debug(P9_DEBUG_VFS, "name:%s flags:0x%x mode:0x%x\n",
263 		 name, flags, omode);
264 
265 	dfid = v9fs_parent_fid(dentry);
266 	if (IS_ERR(dfid)) {
267 		err = PTR_ERR(dfid);
268 		p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
269 		goto out;
270 	}
271 
272 	/* clone a fid to use for creation */
273 	ofid = clone_fid(dfid);
274 	if (IS_ERR(ofid)) {
275 		err = PTR_ERR(ofid);
276 		p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
277 		goto out;
278 	}
279 
280 	gid = v9fs_get_fsgid_for_create(dir);
281 
282 	mode = omode;
283 	/* Update mode based on ACL value */
284 	err = v9fs_acl_mode(dir, &mode, &dacl, &pacl);
285 	if (err) {
286 		p9_debug(P9_DEBUG_VFS, "Failed to get acl values in creat %d\n",
287 			 err);
288 		goto error;
289 	}
290 	err = p9_client_create_dotl(ofid, name, v9fs_open_to_dotl_flags(flags),
291 				    mode, gid, &qid);
292 	if (err < 0) {
293 		p9_debug(P9_DEBUG_VFS, "p9_client_open_dotl failed in creat %d\n",
294 			 err);
295 		goto error;
296 	}
297 	v9fs_invalidate_inode_attr(dir);
298 
299 	/* instantiate inode and assign the unopened fid to the dentry */
300 	fid = p9_client_walk(dfid, 1, &name, 1);
301 	p9_client_clunk(dfid);
302 	if (IS_ERR(fid)) {
303 		err = PTR_ERR(fid);
304 		p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
305 		fid = NULL;
306 		goto error;
307 	}
308 	inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
309 	if (IS_ERR(inode)) {
310 		err = PTR_ERR(inode);
311 		p9_debug(P9_DEBUG_VFS, "inode creation failed %d\n", err);
312 		goto error;
313 	}
314 	/* Now set the ACL based on the default value */
315 	v9fs_set_create_acl(inode, fid, dacl, pacl);
316 
317 	v9fs_fid_add(dentry, fid);
318 	d_instantiate(dentry, inode);
319 
320 	v9inode = V9FS_I(inode);
321 	mutex_lock(&v9inode->v_mutex);
322 	if ((v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) &&
323 	    !v9inode->writeback_fid &&
324 	    ((flags & O_ACCMODE) != O_RDONLY)) {
325 		/*
326 		 * clone a fid and add it to writeback_fid
327 		 * we do it during open time instead of
328 		 * page dirty time via write_begin/page_mkwrite
329 		 * because we want write after unlink usecase
330 		 * to work.
331 		 */
332 		inode_fid = v9fs_writeback_fid(dentry);
333 		if (IS_ERR(inode_fid)) {
334 			err = PTR_ERR(inode_fid);
335 			mutex_unlock(&v9inode->v_mutex);
336 			goto err_clunk_old_fid;
337 		}
338 		v9inode->writeback_fid = (void *) inode_fid;
339 	}
340 	mutex_unlock(&v9inode->v_mutex);
341 	/* Since we are opening a file, assign the open fid to the file */
342 	err = finish_open(file, dentry, generic_file_open);
343 	if (err)
344 		goto err_clunk_old_fid;
345 	file->private_data = ofid;
346 	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
347 		v9fs_cache_inode_set_cookie(inode, file);
348 	v9fs_open_fid_add(inode, ofid);
349 	file->f_mode |= FMODE_CREATED;
350 out:
351 	v9fs_put_acl(dacl, pacl);
352 	dput(res);
353 	return err;
354 
355 error:
356 	if (fid)
357 		p9_client_clunk(fid);
358 err_clunk_old_fid:
359 	if (ofid)
360 		p9_client_clunk(ofid);
361 	goto out;
362 }
363 
364 /**
365  * v9fs_vfs_mkdir_dotl - VFS mkdir hook to create a directory
366  * @mnt_userns: The user namespace of the mount
367  * @dir:  inode that is being unlinked
368  * @dentry: dentry that is being unlinked
369  * @omode: mode for new directory
370  *
371  */
372 
373 static int v9fs_vfs_mkdir_dotl(struct user_namespace *mnt_userns,
374 			       struct inode *dir, struct dentry *dentry,
375 			       umode_t omode)
376 {
377 	int err;
378 	struct v9fs_session_info *v9ses;
379 	struct p9_fid *fid = NULL, *dfid = NULL;
380 	kgid_t gid;
381 	const unsigned char *name;
382 	umode_t mode;
383 	struct inode *inode;
384 	struct p9_qid qid;
385 	struct posix_acl *dacl = NULL, *pacl = NULL;
386 
387 	p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry);
388 	err = 0;
389 	v9ses = v9fs_inode2v9ses(dir);
390 
391 	omode |= S_IFDIR;
392 	if (dir->i_mode & S_ISGID)
393 		omode |= S_ISGID;
394 
395 	dfid = v9fs_parent_fid(dentry);
396 	if (IS_ERR(dfid)) {
397 		err = PTR_ERR(dfid);
398 		p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
399 		dfid = NULL;
400 		goto error;
401 	}
402 
403 	gid = v9fs_get_fsgid_for_create(dir);
404 	mode = omode;
405 	/* Update mode based on ACL value */
406 	err = v9fs_acl_mode(dir, &mode, &dacl, &pacl);
407 	if (err) {
408 		p9_debug(P9_DEBUG_VFS, "Failed to get acl values in mkdir %d\n",
409 			 err);
410 		goto error;
411 	}
412 	name = dentry->d_name.name;
413 	err = p9_client_mkdir_dotl(dfid, name, mode, gid, &qid);
414 	if (err < 0)
415 		goto error;
416 	fid = p9_client_walk(dfid, 1, &name, 1);
417 	if (IS_ERR(fid)) {
418 		err = PTR_ERR(fid);
419 		p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n",
420 			 err);
421 		fid = NULL;
422 		goto error;
423 	}
424 
425 	/* instantiate inode and assign the unopened fid to the dentry */
426 	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
427 		inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
428 		if (IS_ERR(inode)) {
429 			err = PTR_ERR(inode);
430 			p9_debug(P9_DEBUG_VFS, "inode creation failed %d\n",
431 				 err);
432 			goto error;
433 		}
434 		v9fs_fid_add(dentry, fid);
435 		v9fs_set_create_acl(inode, fid, dacl, pacl);
436 		d_instantiate(dentry, inode);
437 		fid = NULL;
438 		err = 0;
439 	} else {
440 		/*
441 		 * Not in cached mode. No need to populate
442 		 * inode with stat. We need to get an inode
443 		 * so that we can set the acl with dentry
444 		 */
445 		inode = v9fs_get_inode(dir->i_sb, mode, 0);
446 		if (IS_ERR(inode)) {
447 			err = PTR_ERR(inode);
448 			goto error;
449 		}
450 		v9fs_set_create_acl(inode, fid, dacl, pacl);
451 		d_instantiate(dentry, inode);
452 	}
453 	inc_nlink(dir);
454 	v9fs_invalidate_inode_attr(dir);
455 error:
456 	if (fid)
457 		p9_client_clunk(fid);
458 	v9fs_put_acl(dacl, pacl);
459 	p9_client_clunk(dfid);
460 	return err;
461 }
462 
463 static int
464 v9fs_vfs_getattr_dotl(struct user_namespace *mnt_userns,
465 		      const struct path *path, struct kstat *stat,
466 		      u32 request_mask, unsigned int flags)
467 {
468 	struct dentry *dentry = path->dentry;
469 	struct v9fs_session_info *v9ses;
470 	struct p9_fid *fid;
471 	struct p9_stat_dotl *st;
472 
473 	p9_debug(P9_DEBUG_VFS, "dentry: %p\n", dentry);
474 	v9ses = v9fs_dentry2v9ses(dentry);
475 	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
476 		generic_fillattr(&init_user_ns, d_inode(dentry), stat);
477 		return 0;
478 	}
479 	fid = v9fs_fid_lookup(dentry);
480 	if (IS_ERR(fid))
481 		return PTR_ERR(fid);
482 
483 	/* Ask for all the fields in stat structure. Server will return
484 	 * whatever it supports
485 	 */
486 
487 	st = p9_client_getattr_dotl(fid, P9_STATS_ALL);
488 	p9_client_clunk(fid);
489 	if (IS_ERR(st))
490 		return PTR_ERR(st);
491 
492 	v9fs_stat2inode_dotl(st, d_inode(dentry), 0);
493 	generic_fillattr(&init_user_ns, d_inode(dentry), stat);
494 	/* Change block size to what the server returned */
495 	stat->blksize = st->st_blksize;
496 
497 	kfree(st);
498 	return 0;
499 }
500 
501 /*
502  * Attribute flags.
503  */
504 #define P9_ATTR_MODE		(1 << 0)
505 #define P9_ATTR_UID		(1 << 1)
506 #define P9_ATTR_GID		(1 << 2)
507 #define P9_ATTR_SIZE		(1 << 3)
508 #define P9_ATTR_ATIME		(1 << 4)
509 #define P9_ATTR_MTIME		(1 << 5)
510 #define P9_ATTR_CTIME		(1 << 6)
511 #define P9_ATTR_ATIME_SET	(1 << 7)
512 #define P9_ATTR_MTIME_SET	(1 << 8)
513 
514 struct dotl_iattr_map {
515 	int iattr_valid;
516 	int p9_iattr_valid;
517 };
518 
519 static int v9fs_mapped_iattr_valid(int iattr_valid)
520 {
521 	int i;
522 	int p9_iattr_valid = 0;
523 	struct dotl_iattr_map dotl_iattr_map[] = {
524 		{ ATTR_MODE,		P9_ATTR_MODE },
525 		{ ATTR_UID,		P9_ATTR_UID },
526 		{ ATTR_GID,		P9_ATTR_GID },
527 		{ ATTR_SIZE,		P9_ATTR_SIZE },
528 		{ ATTR_ATIME,		P9_ATTR_ATIME },
529 		{ ATTR_MTIME,		P9_ATTR_MTIME },
530 		{ ATTR_CTIME,		P9_ATTR_CTIME },
531 		{ ATTR_ATIME_SET,	P9_ATTR_ATIME_SET },
532 		{ ATTR_MTIME_SET,	P9_ATTR_MTIME_SET },
533 	};
534 	for (i = 0; i < ARRAY_SIZE(dotl_iattr_map); i++) {
535 		if (iattr_valid & dotl_iattr_map[i].iattr_valid)
536 			p9_iattr_valid |= dotl_iattr_map[i].p9_iattr_valid;
537 	}
538 	return p9_iattr_valid;
539 }
540 
541 /**
542  * v9fs_vfs_setattr_dotl - set file metadata
543  * @mnt_userns: The user namespace of the mount
544  * @dentry: file whose metadata to set
545  * @iattr: metadata assignment structure
546  *
547  */
548 
549 int v9fs_vfs_setattr_dotl(struct user_namespace *mnt_userns,
550 			  struct dentry *dentry, struct iattr *iattr)
551 {
552 	int retval, use_dentry = 0;
553 	struct p9_fid *fid = NULL;
554 	struct p9_iattr_dotl p9attr;
555 	struct inode *inode = d_inode(dentry);
556 
557 	p9_debug(P9_DEBUG_VFS, "\n");
558 
559 	retval = setattr_prepare(&init_user_ns, dentry, iattr);
560 	if (retval)
561 		return retval;
562 
563 	p9attr.valid = v9fs_mapped_iattr_valid(iattr->ia_valid);
564 	p9attr.mode = iattr->ia_mode;
565 	p9attr.uid = iattr->ia_uid;
566 	p9attr.gid = iattr->ia_gid;
567 	p9attr.size = iattr->ia_size;
568 	p9attr.atime_sec = iattr->ia_atime.tv_sec;
569 	p9attr.atime_nsec = iattr->ia_atime.tv_nsec;
570 	p9attr.mtime_sec = iattr->ia_mtime.tv_sec;
571 	p9attr.mtime_nsec = iattr->ia_mtime.tv_nsec;
572 
573 	if (iattr->ia_valid & ATTR_FILE) {
574 		fid = iattr->ia_file->private_data;
575 		WARN_ON(!fid);
576 	}
577 	if (!fid) {
578 		fid = v9fs_fid_lookup(dentry);
579 		use_dentry = 1;
580 	}
581 	if (IS_ERR(fid))
582 		return PTR_ERR(fid);
583 
584 	/* Write all dirty data */
585 	if (S_ISREG(inode->i_mode))
586 		filemap_write_and_wait(inode->i_mapping);
587 
588 	retval = p9_client_setattr(fid, &p9attr);
589 	if (retval < 0) {
590 		if (use_dentry)
591 			p9_client_clunk(fid);
592 		return retval;
593 	}
594 
595 	if ((iattr->ia_valid & ATTR_SIZE) &&
596 	    iattr->ia_size != i_size_read(inode))
597 		truncate_setsize(inode, iattr->ia_size);
598 
599 	v9fs_invalidate_inode_attr(inode);
600 	setattr_copy(&init_user_ns, inode, iattr);
601 	mark_inode_dirty(inode);
602 	if (iattr->ia_valid & ATTR_MODE) {
603 		/* We also want to update ACL when we update mode bits */
604 		retval = v9fs_acl_chmod(inode, fid);
605 		if (retval < 0) {
606 			if (use_dentry)
607 				p9_client_clunk(fid);
608 			return retval;
609 		}
610 	}
611 	if (use_dentry)
612 		p9_client_clunk(fid);
613 
614 	return 0;
615 }
616 
617 /**
618  * v9fs_stat2inode_dotl - populate an inode structure with stat info
619  * @stat: stat structure
620  * @inode: inode to populate
621  * @flags: ctrl flags (e.g. V9FS_STAT2INODE_KEEP_ISIZE)
622  *
623  */
624 
625 void
626 v9fs_stat2inode_dotl(struct p9_stat_dotl *stat, struct inode *inode,
627 		      unsigned int flags)
628 {
629 	umode_t mode;
630 	struct v9fs_inode *v9inode = V9FS_I(inode);
631 
632 	if ((stat->st_result_mask & P9_STATS_BASIC) == P9_STATS_BASIC) {
633 		inode->i_atime.tv_sec = stat->st_atime_sec;
634 		inode->i_atime.tv_nsec = stat->st_atime_nsec;
635 		inode->i_mtime.tv_sec = stat->st_mtime_sec;
636 		inode->i_mtime.tv_nsec = stat->st_mtime_nsec;
637 		inode->i_ctime.tv_sec = stat->st_ctime_sec;
638 		inode->i_ctime.tv_nsec = stat->st_ctime_nsec;
639 		inode->i_uid = stat->st_uid;
640 		inode->i_gid = stat->st_gid;
641 		set_nlink(inode, stat->st_nlink);
642 
643 		mode = stat->st_mode & S_IALLUGO;
644 		mode |= inode->i_mode & ~S_IALLUGO;
645 		inode->i_mode = mode;
646 
647 		if (!(flags & V9FS_STAT2INODE_KEEP_ISIZE))
648 			v9fs_i_size_write(inode, stat->st_size);
649 		inode->i_blocks = stat->st_blocks;
650 	} else {
651 		if (stat->st_result_mask & P9_STATS_ATIME) {
652 			inode->i_atime.tv_sec = stat->st_atime_sec;
653 			inode->i_atime.tv_nsec = stat->st_atime_nsec;
654 		}
655 		if (stat->st_result_mask & P9_STATS_MTIME) {
656 			inode->i_mtime.tv_sec = stat->st_mtime_sec;
657 			inode->i_mtime.tv_nsec = stat->st_mtime_nsec;
658 		}
659 		if (stat->st_result_mask & P9_STATS_CTIME) {
660 			inode->i_ctime.tv_sec = stat->st_ctime_sec;
661 			inode->i_ctime.tv_nsec = stat->st_ctime_nsec;
662 		}
663 		if (stat->st_result_mask & P9_STATS_UID)
664 			inode->i_uid = stat->st_uid;
665 		if (stat->st_result_mask & P9_STATS_GID)
666 			inode->i_gid = stat->st_gid;
667 		if (stat->st_result_mask & P9_STATS_NLINK)
668 			set_nlink(inode, stat->st_nlink);
669 		if (stat->st_result_mask & P9_STATS_MODE) {
670 			mode = stat->st_mode & S_IALLUGO;
671 			mode |= inode->i_mode & ~S_IALLUGO;
672 			inode->i_mode = mode;
673 		}
674 		if (!(flags & V9FS_STAT2INODE_KEEP_ISIZE) &&
675 		    stat->st_result_mask & P9_STATS_SIZE)
676 			v9fs_i_size_write(inode, stat->st_size);
677 		if (stat->st_result_mask & P9_STATS_BLOCKS)
678 			inode->i_blocks = stat->st_blocks;
679 	}
680 	if (stat->st_result_mask & P9_STATS_GEN)
681 		inode->i_generation = stat->st_gen;
682 
683 	/* Currently we don't support P9_STATS_BTIME and P9_STATS_DATA_VERSION
684 	 * because the inode structure does not have fields for them.
685 	 */
686 	v9inode->cache_validity &= ~V9FS_INO_INVALID_ATTR;
687 }
688 
689 static int
690 v9fs_vfs_symlink_dotl(struct user_namespace *mnt_userns, struct inode *dir,
691 		      struct dentry *dentry, const char *symname)
692 {
693 	int err;
694 	kgid_t gid;
695 	const unsigned char *name;
696 	struct p9_qid qid;
697 	struct inode *inode;
698 	struct p9_fid *dfid;
699 	struct p9_fid *fid = NULL;
700 	struct v9fs_session_info *v9ses;
701 
702 	name = dentry->d_name.name;
703 	p9_debug(P9_DEBUG_VFS, "%lu,%s,%s\n", dir->i_ino, name, symname);
704 	v9ses = v9fs_inode2v9ses(dir);
705 
706 	dfid = v9fs_parent_fid(dentry);
707 	if (IS_ERR(dfid)) {
708 		err = PTR_ERR(dfid);
709 		p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
710 		return err;
711 	}
712 
713 	gid = v9fs_get_fsgid_for_create(dir);
714 
715 	/* Server doesn't alter fid on TSYMLINK. Hence no need to clone it. */
716 	err = p9_client_symlink(dfid, name, symname, gid, &qid);
717 
718 	if (err < 0) {
719 		p9_debug(P9_DEBUG_VFS, "p9_client_symlink failed %d\n", err);
720 		goto error;
721 	}
722 
723 	v9fs_invalidate_inode_attr(dir);
724 	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
725 		/* Now walk from the parent so we can get an unopened fid. */
726 		fid = p9_client_walk(dfid, 1, &name, 1);
727 		if (IS_ERR(fid)) {
728 			err = PTR_ERR(fid);
729 			p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n",
730 				 err);
731 			fid = NULL;
732 			goto error;
733 		}
734 
735 		/* instantiate inode and assign the unopened fid to dentry */
736 		inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
737 		if (IS_ERR(inode)) {
738 			err = PTR_ERR(inode);
739 			p9_debug(P9_DEBUG_VFS, "inode creation failed %d\n",
740 				 err);
741 			goto error;
742 		}
743 		v9fs_fid_add(dentry, fid);
744 		d_instantiate(dentry, inode);
745 		fid = NULL;
746 		err = 0;
747 	} else {
748 		/* Not in cached mode. No need to populate inode with stat */
749 		inode = v9fs_get_inode(dir->i_sb, S_IFLNK, 0);
750 		if (IS_ERR(inode)) {
751 			err = PTR_ERR(inode);
752 			goto error;
753 		}
754 		d_instantiate(dentry, inode);
755 	}
756 
757 error:
758 	if (fid)
759 		p9_client_clunk(fid);
760 
761 	p9_client_clunk(dfid);
762 	return err;
763 }
764 
765 /**
766  * v9fs_vfs_link_dotl - create a hardlink for dotl
767  * @old_dentry: dentry for file to link to
768  * @dir: inode destination for new link
769  * @dentry: dentry for link
770  *
771  */
772 
773 static int
774 v9fs_vfs_link_dotl(struct dentry *old_dentry, struct inode *dir,
775 		struct dentry *dentry)
776 {
777 	int err;
778 	struct p9_fid *dfid, *oldfid;
779 	struct v9fs_session_info *v9ses;
780 
781 	p9_debug(P9_DEBUG_VFS, "dir ino: %lu, old_name: %pd, new_name: %pd\n",
782 		 dir->i_ino, old_dentry, dentry);
783 
784 	v9ses = v9fs_inode2v9ses(dir);
785 	dfid = v9fs_parent_fid(dentry);
786 	if (IS_ERR(dfid))
787 		return PTR_ERR(dfid);
788 
789 	oldfid = v9fs_fid_lookup(old_dentry);
790 	if (IS_ERR(oldfid)) {
791 		p9_client_clunk(dfid);
792 		return PTR_ERR(oldfid);
793 	}
794 
795 	err = p9_client_link(dfid, oldfid, dentry->d_name.name);
796 
797 	p9_client_clunk(dfid);
798 	p9_client_clunk(oldfid);
799 	if (err < 0) {
800 		p9_debug(P9_DEBUG_VFS, "p9_client_link failed %d\n", err);
801 		return err;
802 	}
803 
804 	v9fs_invalidate_inode_attr(dir);
805 	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
806 		/* Get the latest stat info from server. */
807 		struct p9_fid *fid;
808 
809 		fid = v9fs_fid_lookup(old_dentry);
810 		if (IS_ERR(fid))
811 			return PTR_ERR(fid);
812 
813 		v9fs_refresh_inode_dotl(fid, d_inode(old_dentry));
814 		p9_client_clunk(fid);
815 	}
816 	ihold(d_inode(old_dentry));
817 	d_instantiate(dentry, d_inode(old_dentry));
818 
819 	return err;
820 }
821 
822 /**
823  * v9fs_vfs_mknod_dotl - create a special file
824  * @mnt_userns: The user namespace of the mount
825  * @dir: inode destination for new link
826  * @dentry: dentry for file
827  * @omode: mode for creation
828  * @rdev: device associated with special file
829  *
830  */
831 static int
832 v9fs_vfs_mknod_dotl(struct user_namespace *mnt_userns, struct inode *dir,
833 		    struct dentry *dentry, umode_t omode, dev_t rdev)
834 {
835 	int err;
836 	kgid_t gid;
837 	const unsigned char *name;
838 	umode_t mode;
839 	struct v9fs_session_info *v9ses;
840 	struct p9_fid *fid = NULL, *dfid = NULL;
841 	struct inode *inode;
842 	struct p9_qid qid;
843 	struct posix_acl *dacl = NULL, *pacl = NULL;
844 
845 	p9_debug(P9_DEBUG_VFS, " %lu,%pd mode: %x MAJOR: %u MINOR: %u\n",
846 		 dir->i_ino, dentry, omode,
847 		 MAJOR(rdev), MINOR(rdev));
848 
849 	v9ses = v9fs_inode2v9ses(dir);
850 	dfid = v9fs_parent_fid(dentry);
851 	if (IS_ERR(dfid)) {
852 		err = PTR_ERR(dfid);
853 		p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
854 		dfid = NULL;
855 		goto error;
856 	}
857 
858 	gid = v9fs_get_fsgid_for_create(dir);
859 	mode = omode;
860 	/* Update mode based on ACL value */
861 	err = v9fs_acl_mode(dir, &mode, &dacl, &pacl);
862 	if (err) {
863 		p9_debug(P9_DEBUG_VFS, "Failed to get acl values in mknod %d\n",
864 			 err);
865 		goto error;
866 	}
867 	name = dentry->d_name.name;
868 
869 	err = p9_client_mknod_dotl(dfid, name, mode, rdev, gid, &qid);
870 	if (err < 0)
871 		goto error;
872 
873 	v9fs_invalidate_inode_attr(dir);
874 	fid = p9_client_walk(dfid, 1, &name, 1);
875 	if (IS_ERR(fid)) {
876 		err = PTR_ERR(fid);
877 		p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n",
878 			 err);
879 		fid = NULL;
880 		goto error;
881 	}
882 
883 	/* instantiate inode and assign the unopened fid to the dentry */
884 	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
885 		inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
886 		if (IS_ERR(inode)) {
887 			err = PTR_ERR(inode);
888 			p9_debug(P9_DEBUG_VFS, "inode creation failed %d\n",
889 				 err);
890 			goto error;
891 		}
892 		v9fs_set_create_acl(inode, fid, dacl, pacl);
893 		v9fs_fid_add(dentry, fid);
894 		d_instantiate(dentry, inode);
895 		fid = NULL;
896 		err = 0;
897 	} else {
898 		/*
899 		 * Not in cached mode. No need to populate inode with stat.
900 		 * socket syscall returns a fd, so we need instantiate
901 		 */
902 		inode = v9fs_get_inode(dir->i_sb, mode, rdev);
903 		if (IS_ERR(inode)) {
904 			err = PTR_ERR(inode);
905 			goto error;
906 		}
907 		v9fs_set_create_acl(inode, fid, dacl, pacl);
908 		d_instantiate(dentry, inode);
909 	}
910 error:
911 	if (fid)
912 		p9_client_clunk(fid);
913 	v9fs_put_acl(dacl, pacl);
914 	p9_client_clunk(dfid);
915 
916 	return err;
917 }
918 
919 /**
920  * v9fs_vfs_get_link_dotl - follow a symlink path
921  * @dentry: dentry for symlink
922  * @inode: inode for symlink
923  * @done: destructor for return value
924  */
925 
926 static const char *
927 v9fs_vfs_get_link_dotl(struct dentry *dentry,
928 		       struct inode *inode,
929 		       struct delayed_call *done)
930 {
931 	struct p9_fid *fid;
932 	char *target;
933 	int retval;
934 
935 	if (!dentry)
936 		return ERR_PTR(-ECHILD);
937 
938 	p9_debug(P9_DEBUG_VFS, "%pd\n", dentry);
939 
940 	fid = v9fs_fid_lookup(dentry);
941 	if (IS_ERR(fid))
942 		return ERR_CAST(fid);
943 	retval = p9_client_readlink(fid, &target);
944 	p9_client_clunk(fid);
945 	if (retval)
946 		return ERR_PTR(retval);
947 	set_delayed_call(done, kfree_link, target);
948 	return target;
949 }
950 
951 int v9fs_refresh_inode_dotl(struct p9_fid *fid, struct inode *inode)
952 {
953 	struct p9_stat_dotl *st;
954 	struct v9fs_session_info *v9ses;
955 	unsigned int flags;
956 
957 	v9ses = v9fs_inode2v9ses(inode);
958 	st = p9_client_getattr_dotl(fid, P9_STATS_ALL);
959 	if (IS_ERR(st))
960 		return PTR_ERR(st);
961 	/*
962 	 * Don't update inode if the file type is different
963 	 */
964 	if (inode_wrong_type(inode, st->st_mode))
965 		goto out;
966 
967 	/*
968 	 * We don't want to refresh inode->i_size,
969 	 * because we may have cached data
970 	 */
971 	flags = (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) ?
972 		V9FS_STAT2INODE_KEEP_ISIZE : 0;
973 	v9fs_stat2inode_dotl(st, inode, flags);
974 out:
975 	kfree(st);
976 	return 0;
977 }
978 
979 const struct inode_operations v9fs_dir_inode_operations_dotl = {
980 	.create = v9fs_vfs_create_dotl,
981 	.atomic_open = v9fs_vfs_atomic_open_dotl,
982 	.lookup = v9fs_vfs_lookup,
983 	.link = v9fs_vfs_link_dotl,
984 	.symlink = v9fs_vfs_symlink_dotl,
985 	.unlink = v9fs_vfs_unlink,
986 	.mkdir = v9fs_vfs_mkdir_dotl,
987 	.rmdir = v9fs_vfs_rmdir,
988 	.mknod = v9fs_vfs_mknod_dotl,
989 	.rename = v9fs_vfs_rename,
990 	.getattr = v9fs_vfs_getattr_dotl,
991 	.setattr = v9fs_vfs_setattr_dotl,
992 	.listxattr = v9fs_listxattr,
993 	.get_acl = v9fs_iop_get_acl,
994 };
995 
996 const struct inode_operations v9fs_file_inode_operations_dotl = {
997 	.getattr = v9fs_vfs_getattr_dotl,
998 	.setattr = v9fs_vfs_setattr_dotl,
999 	.listxattr = v9fs_listxattr,
1000 	.get_acl = v9fs_iop_get_acl,
1001 };
1002 
1003 const struct inode_operations v9fs_symlink_inode_operations_dotl = {
1004 	.get_link = v9fs_vfs_get_link_dotl,
1005 	.getattr = v9fs_vfs_getattr_dotl,
1006 	.setattr = v9fs_vfs_setattr_dotl,
1007 	.listxattr = v9fs_listxattr,
1008 };
1009