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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 
v9fs_get_fsgid_for_create(struct inode * dir_inode)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 
v9fs_test_inode_dotl(struct inode * inode,void * data)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 */
v9fs_test_new_inode_dotl(struct inode * inode,void * data)83 static int v9fs_test_new_inode_dotl(struct inode *inode, void *data)
84 {
85 	return 0;
86 }
87 
v9fs_set_inode_dotl(struct inode * inode,void * data)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 
v9fs_qid_iget_dotl(struct super_block * sb,struct p9_qid * qid,struct p9_fid * fid,struct p9_stat_dotl * st,int new)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_set_netfs_context(inode);
134 	v9fs_cache_inode_get_cookie(inode);
135 	retval = v9fs_get_acl(inode, fid);
136 	if (retval)
137 		goto error;
138 
139 	unlock_new_inode(inode);
140 	return inode;
141 error:
142 	iget_failed(inode);
143 	return ERR_PTR(retval);
144 
145 }
146 
147 struct inode *
v9fs_inode_from_fid_dotl(struct v9fs_session_info * v9ses,struct p9_fid * fid,struct super_block * sb,int new)148 v9fs_inode_from_fid_dotl(struct v9fs_session_info *v9ses, struct p9_fid *fid,
149 			 struct super_block *sb, int new)
150 {
151 	struct p9_stat_dotl *st;
152 	struct inode *inode = NULL;
153 
154 	st = p9_client_getattr_dotl(fid, P9_STATS_BASIC | P9_STATS_GEN);
155 	if (IS_ERR(st))
156 		return ERR_CAST(st);
157 
158 	inode = v9fs_qid_iget_dotl(sb, &st->qid, fid, st, new);
159 	kfree(st);
160 	return inode;
161 }
162 
163 struct dotl_openflag_map {
164 	int open_flag;
165 	int dotl_flag;
166 };
167 
v9fs_mapped_dotl_flags(int flags)168 static int v9fs_mapped_dotl_flags(int flags)
169 {
170 	int i;
171 	int rflags = 0;
172 	struct dotl_openflag_map dotl_oflag_map[] = {
173 		{ O_CREAT,	P9_DOTL_CREATE },
174 		{ O_EXCL,	P9_DOTL_EXCL },
175 		{ O_NOCTTY,	P9_DOTL_NOCTTY },
176 		{ O_APPEND,	P9_DOTL_APPEND },
177 		{ O_NONBLOCK,	P9_DOTL_NONBLOCK },
178 		{ O_DSYNC,	P9_DOTL_DSYNC },
179 		{ FASYNC,	P9_DOTL_FASYNC },
180 		{ O_DIRECT,	P9_DOTL_DIRECT },
181 		{ O_LARGEFILE,	P9_DOTL_LARGEFILE },
182 		{ O_DIRECTORY,	P9_DOTL_DIRECTORY },
183 		{ O_NOFOLLOW,	P9_DOTL_NOFOLLOW },
184 		{ O_NOATIME,	P9_DOTL_NOATIME },
185 		{ O_CLOEXEC,	P9_DOTL_CLOEXEC },
186 		{ O_SYNC,	P9_DOTL_SYNC},
187 	};
188 	for (i = 0; i < ARRAY_SIZE(dotl_oflag_map); i++) {
189 		if (flags & dotl_oflag_map[i].open_flag)
190 			rflags |= dotl_oflag_map[i].dotl_flag;
191 	}
192 	return rflags;
193 }
194 
195 /**
196  * v9fs_open_to_dotl_flags- convert Linux specific open flags to
197  * plan 9 open flag.
198  * @flags: flags to convert
199  */
v9fs_open_to_dotl_flags(int flags)200 int v9fs_open_to_dotl_flags(int flags)
201 {
202 	int rflags = 0;
203 
204 	/*
205 	 * We have same bits for P9_DOTL_READONLY, P9_DOTL_WRONLY
206 	 * and P9_DOTL_NOACCESS
207 	 */
208 	rflags |= flags & O_ACCMODE;
209 	rflags |= v9fs_mapped_dotl_flags(flags);
210 
211 	return rflags;
212 }
213 
214 /**
215  * v9fs_vfs_create_dotl - VFS hook to create files for 9P2000.L protocol.
216  * @mnt_userns: The user namespace of the mount
217  * @dir: directory inode that is being created
218  * @dentry:  dentry that is being deleted
219  * @omode: create permissions
220  * @excl: True if the file must not yet exist
221  *
222  */
223 static int
v9fs_vfs_create_dotl(struct user_namespace * mnt_userns,struct inode * dir,struct dentry * dentry,umode_t omode,bool excl)224 v9fs_vfs_create_dotl(struct user_namespace *mnt_userns, struct inode *dir,
225 		     struct dentry *dentry, umode_t omode, bool excl)
226 {
227 	return v9fs_vfs_mknod_dotl(mnt_userns, dir, dentry, omode, 0);
228 }
229 
230 static int
v9fs_vfs_atomic_open_dotl(struct inode * dir,struct dentry * dentry,struct file * file,unsigned int flags,umode_t omode)231 v9fs_vfs_atomic_open_dotl(struct inode *dir, struct dentry *dentry,
232 			  struct file *file, unsigned int flags, umode_t omode)
233 {
234 	int err = 0;
235 	kgid_t gid;
236 	umode_t mode;
237 	const unsigned char *name = NULL;
238 	struct p9_qid qid;
239 	struct inode *inode;
240 	struct p9_fid *fid = NULL;
241 	struct v9fs_inode *v9inode;
242 	struct p9_fid *dfid = NULL, *ofid = NULL, *inode_fid = NULL;
243 	struct v9fs_session_info *v9ses;
244 	struct posix_acl *pacl = NULL, *dacl = NULL;
245 	struct dentry *res = NULL;
246 
247 	if (d_in_lookup(dentry)) {
248 		res = v9fs_vfs_lookup(dir, dentry, 0);
249 		if (IS_ERR(res))
250 			return PTR_ERR(res);
251 
252 		if (res)
253 			dentry = res;
254 	}
255 
256 	/* Only creates */
257 	if (!(flags & O_CREAT) || d_really_is_positive(dentry))
258 		return	finish_no_open(file, res);
259 
260 	v9ses = v9fs_inode2v9ses(dir);
261 
262 	name = dentry->d_name.name;
263 	p9_debug(P9_DEBUG_VFS, "name:%s flags:0x%x mode:0x%x\n",
264 		 name, flags, omode);
265 
266 	dfid = v9fs_parent_fid(dentry);
267 	if (IS_ERR(dfid)) {
268 		err = PTR_ERR(dfid);
269 		p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
270 		goto out;
271 	}
272 
273 	/* clone a fid to use for creation */
274 	ofid = clone_fid(dfid);
275 	if (IS_ERR(ofid)) {
276 		err = PTR_ERR(ofid);
277 		p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
278 		goto out;
279 	}
280 
281 	gid = v9fs_get_fsgid_for_create(dir);
282 
283 	mode = omode;
284 	/* Update mode based on ACL value */
285 	err = v9fs_acl_mode(dir, &mode, &dacl, &pacl);
286 	if (err) {
287 		p9_debug(P9_DEBUG_VFS, "Failed to get acl values in creat %d\n",
288 			 err);
289 		goto out;
290 	}
291 	err = p9_client_create_dotl(ofid, name, v9fs_open_to_dotl_flags(flags),
292 				    mode, gid, &qid);
293 	if (err < 0) {
294 		p9_debug(P9_DEBUG_VFS, "p9_client_open_dotl failed in creat %d\n",
295 			 err);
296 		goto out;
297 	}
298 	v9fs_invalidate_inode_attr(dir);
299 
300 	/* instantiate inode and assign the unopened fid to the dentry */
301 	fid = p9_client_walk(dfid, 1, &name, 1);
302 	if (IS_ERR(fid)) {
303 		err = PTR_ERR(fid);
304 		p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
305 		goto out;
306 	}
307 	inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
308 	if (IS_ERR(inode)) {
309 		err = PTR_ERR(inode);
310 		p9_debug(P9_DEBUG_VFS, "inode creation failed %d\n", err);
311 		goto out;
312 	}
313 	/* Now set the ACL based on the default value */
314 	v9fs_set_create_acl(inode, fid, dacl, pacl);
315 
316 	v9fs_fid_add(dentry, &fid);
317 	d_instantiate(dentry, inode);
318 
319 	v9inode = V9FS_I(inode);
320 	mutex_lock(&v9inode->v_mutex);
321 	if ((v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) &&
322 	    !v9inode->writeback_fid &&
323 	    ((flags & O_ACCMODE) != O_RDONLY)) {
324 		/*
325 		 * clone a fid and add it to writeback_fid
326 		 * we do it during open time instead of
327 		 * page dirty time via write_begin/page_mkwrite
328 		 * because we want write after unlink usecase
329 		 * to work.
330 		 */
331 		inode_fid = v9fs_writeback_fid(dentry);
332 		if (IS_ERR(inode_fid)) {
333 			err = PTR_ERR(inode_fid);
334 			mutex_unlock(&v9inode->v_mutex);
335 			goto out;
336 		}
337 		v9inode->writeback_fid = (void *) inode_fid;
338 	}
339 	mutex_unlock(&v9inode->v_mutex);
340 	/* Since we are opening a file, assign the open fid to the file */
341 	err = finish_open(file, dentry, generic_file_open);
342 	if (err)
343 		goto out;
344 	file->private_data = ofid;
345 	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
346 		fscache_use_cookie(v9fs_inode_cookie(v9inode),
347 				   file->f_mode & FMODE_WRITE);
348 	v9fs_open_fid_add(inode, &ofid);
349 	file->f_mode |= FMODE_CREATED;
350 out:
351 	p9_fid_put(dfid);
352 	p9_fid_put(ofid);
353 	p9_fid_put(fid);
354 	v9fs_put_acl(dacl, pacl);
355 	dput(res);
356 	return err;
357 }
358 
359 /**
360  * v9fs_vfs_mkdir_dotl - VFS mkdir hook to create a directory
361  * @mnt_userns: The user namespace of the mount
362  * @dir:  inode that is being unlinked
363  * @dentry: dentry that is being unlinked
364  * @omode: mode for new directory
365  *
366  */
367 
v9fs_vfs_mkdir_dotl(struct user_namespace * mnt_userns,struct inode * dir,struct dentry * dentry,umode_t omode)368 static int v9fs_vfs_mkdir_dotl(struct user_namespace *mnt_userns,
369 			       struct inode *dir, struct dentry *dentry,
370 			       umode_t omode)
371 {
372 	int err;
373 	struct v9fs_session_info *v9ses;
374 	struct p9_fid *fid = NULL, *dfid = NULL;
375 	kgid_t gid;
376 	const unsigned char *name;
377 	umode_t mode;
378 	struct inode *inode;
379 	struct p9_qid qid;
380 	struct posix_acl *dacl = NULL, *pacl = NULL;
381 
382 	p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry);
383 	err = 0;
384 	v9ses = v9fs_inode2v9ses(dir);
385 
386 	omode |= S_IFDIR;
387 	if (dir->i_mode & S_ISGID)
388 		omode |= S_ISGID;
389 
390 	dfid = v9fs_parent_fid(dentry);
391 	if (IS_ERR(dfid)) {
392 		err = PTR_ERR(dfid);
393 		p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
394 		goto error;
395 	}
396 
397 	gid = v9fs_get_fsgid_for_create(dir);
398 	mode = omode;
399 	/* Update mode based on ACL value */
400 	err = v9fs_acl_mode(dir, &mode, &dacl, &pacl);
401 	if (err) {
402 		p9_debug(P9_DEBUG_VFS, "Failed to get acl values in mkdir %d\n",
403 			 err);
404 		goto error;
405 	}
406 	name = dentry->d_name.name;
407 	err = p9_client_mkdir_dotl(dfid, name, mode, gid, &qid);
408 	if (err < 0)
409 		goto error;
410 	fid = p9_client_walk(dfid, 1, &name, 1);
411 	if (IS_ERR(fid)) {
412 		err = PTR_ERR(fid);
413 		p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n",
414 			 err);
415 		goto error;
416 	}
417 
418 	/* instantiate inode and assign the unopened fid to the dentry */
419 	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
420 		inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
421 		if (IS_ERR(inode)) {
422 			err = PTR_ERR(inode);
423 			p9_debug(P9_DEBUG_VFS, "inode creation failed %d\n",
424 				 err);
425 			goto error;
426 		}
427 		v9fs_fid_add(dentry, &fid);
428 		v9fs_set_create_acl(inode, fid, dacl, pacl);
429 		d_instantiate(dentry, inode);
430 		err = 0;
431 	} else {
432 		/*
433 		 * Not in cached mode. No need to populate
434 		 * inode with stat. We need to get an inode
435 		 * so that we can set the acl with dentry
436 		 */
437 		inode = v9fs_get_inode(dir->i_sb, mode, 0);
438 		if (IS_ERR(inode)) {
439 			err = PTR_ERR(inode);
440 			goto error;
441 		}
442 		v9fs_set_create_acl(inode, fid, dacl, pacl);
443 		d_instantiate(dentry, inode);
444 	}
445 	inc_nlink(dir);
446 	v9fs_invalidate_inode_attr(dir);
447 error:
448 	p9_fid_put(fid);
449 	v9fs_put_acl(dacl, pacl);
450 	p9_fid_put(dfid);
451 	return err;
452 }
453 
454 static int
v9fs_vfs_getattr_dotl(struct user_namespace * mnt_userns,const struct path * path,struct kstat * stat,u32 request_mask,unsigned int flags)455 v9fs_vfs_getattr_dotl(struct user_namespace *mnt_userns,
456 		      const struct path *path, struct kstat *stat,
457 		      u32 request_mask, unsigned int flags)
458 {
459 	struct dentry *dentry = path->dentry;
460 	struct v9fs_session_info *v9ses;
461 	struct p9_fid *fid;
462 	struct p9_stat_dotl *st;
463 
464 	p9_debug(P9_DEBUG_VFS, "dentry: %p\n", dentry);
465 	v9ses = v9fs_dentry2v9ses(dentry);
466 	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
467 		generic_fillattr(&init_user_ns, d_inode(dentry), stat);
468 		return 0;
469 	}
470 	fid = v9fs_fid_lookup(dentry);
471 	if (IS_ERR(fid))
472 		return PTR_ERR(fid);
473 
474 	/* Ask for all the fields in stat structure. Server will return
475 	 * whatever it supports
476 	 */
477 
478 	st = p9_client_getattr_dotl(fid, P9_STATS_ALL);
479 	p9_fid_put(fid);
480 	if (IS_ERR(st))
481 		return PTR_ERR(st);
482 
483 	v9fs_stat2inode_dotl(st, d_inode(dentry), 0);
484 	generic_fillattr(&init_user_ns, d_inode(dentry), stat);
485 	/* Change block size to what the server returned */
486 	stat->blksize = st->st_blksize;
487 
488 	kfree(st);
489 	return 0;
490 }
491 
492 /*
493  * Attribute flags.
494  */
495 #define P9_ATTR_MODE		(1 << 0)
496 #define P9_ATTR_UID		(1 << 1)
497 #define P9_ATTR_GID		(1 << 2)
498 #define P9_ATTR_SIZE		(1 << 3)
499 #define P9_ATTR_ATIME		(1 << 4)
500 #define P9_ATTR_MTIME		(1 << 5)
501 #define P9_ATTR_CTIME		(1 << 6)
502 #define P9_ATTR_ATIME_SET	(1 << 7)
503 #define P9_ATTR_MTIME_SET	(1 << 8)
504 
505 struct dotl_iattr_map {
506 	int iattr_valid;
507 	int p9_iattr_valid;
508 };
509 
v9fs_mapped_iattr_valid(int iattr_valid)510 static int v9fs_mapped_iattr_valid(int iattr_valid)
511 {
512 	int i;
513 	int p9_iattr_valid = 0;
514 	struct dotl_iattr_map dotl_iattr_map[] = {
515 		{ ATTR_MODE,		P9_ATTR_MODE },
516 		{ ATTR_UID,		P9_ATTR_UID },
517 		{ ATTR_GID,		P9_ATTR_GID },
518 		{ ATTR_SIZE,		P9_ATTR_SIZE },
519 		{ ATTR_ATIME,		P9_ATTR_ATIME },
520 		{ ATTR_MTIME,		P9_ATTR_MTIME },
521 		{ ATTR_CTIME,		P9_ATTR_CTIME },
522 		{ ATTR_ATIME_SET,	P9_ATTR_ATIME_SET },
523 		{ ATTR_MTIME_SET,	P9_ATTR_MTIME_SET },
524 	};
525 	for (i = 0; i < ARRAY_SIZE(dotl_iattr_map); i++) {
526 		if (iattr_valid & dotl_iattr_map[i].iattr_valid)
527 			p9_iattr_valid |= dotl_iattr_map[i].p9_iattr_valid;
528 	}
529 	return p9_iattr_valid;
530 }
531 
532 /**
533  * v9fs_vfs_setattr_dotl - set file metadata
534  * @mnt_userns: The user namespace of the mount
535  * @dentry: file whose metadata to set
536  * @iattr: metadata assignment structure
537  *
538  */
539 
v9fs_vfs_setattr_dotl(struct user_namespace * mnt_userns,struct dentry * dentry,struct iattr * iattr)540 int v9fs_vfs_setattr_dotl(struct user_namespace *mnt_userns,
541 			  struct dentry *dentry, struct iattr *iattr)
542 {
543 	int retval, use_dentry = 0;
544 	struct p9_fid *fid = NULL;
545 	struct p9_iattr_dotl p9attr = {
546 		.uid = INVALID_UID,
547 		.gid = INVALID_GID,
548 	};
549 	struct inode *inode = d_inode(dentry);
550 
551 	p9_debug(P9_DEBUG_VFS, "\n");
552 
553 	retval = setattr_prepare(&init_user_ns, dentry, iattr);
554 	if (retval)
555 		return retval;
556 
557 	p9attr.valid = v9fs_mapped_iattr_valid(iattr->ia_valid);
558 	if (iattr->ia_valid & ATTR_MODE)
559 		p9attr.mode = iattr->ia_mode;
560 	if (iattr->ia_valid & ATTR_UID)
561 		p9attr.uid = iattr->ia_uid;
562 	if (iattr->ia_valid & ATTR_GID)
563 		p9attr.gid = iattr->ia_gid;
564 	if (iattr->ia_valid & ATTR_SIZE)
565 		p9attr.size = iattr->ia_size;
566 	if (iattr->ia_valid & ATTR_ATIME_SET) {
567 		p9attr.atime_sec = iattr->ia_atime.tv_sec;
568 		p9attr.atime_nsec = iattr->ia_atime.tv_nsec;
569 	}
570 	if (iattr->ia_valid & ATTR_MTIME_SET) {
571 		p9attr.mtime_sec = iattr->ia_mtime.tv_sec;
572 		p9attr.mtime_nsec = iattr->ia_mtime.tv_nsec;
573 	}
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_fid_put(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_fid_put(fid);
610 			return retval;
611 		}
612 	}
613 	if (use_dentry)
614 		p9_fid_put(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
v9fs_stat2inode_dotl(struct p9_stat_dotl * stat,struct inode * inode,unsigned int flags)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
v9fs_vfs_symlink_dotl(struct user_namespace * mnt_userns,struct inode * dir,struct dentry * dentry,const char * symname)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 			goto error;
734 		}
735 
736 		/* instantiate inode and assign the unopened fid to dentry */
737 		inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
738 		if (IS_ERR(inode)) {
739 			err = PTR_ERR(inode);
740 			p9_debug(P9_DEBUG_VFS, "inode creation failed %d\n",
741 				 err);
742 			goto error;
743 		}
744 		v9fs_fid_add(dentry, &fid);
745 		d_instantiate(dentry, inode);
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 	p9_fid_put(fid);
759 	p9_fid_put(dfid);
760 	return err;
761 }
762 
763 /**
764  * v9fs_vfs_link_dotl - create a hardlink for dotl
765  * @old_dentry: dentry for file to link to
766  * @dir: inode destination for new link
767  * @dentry: dentry for link
768  *
769  */
770 
771 static int
v9fs_vfs_link_dotl(struct dentry * old_dentry,struct inode * dir,struct dentry * dentry)772 v9fs_vfs_link_dotl(struct dentry *old_dentry, struct inode *dir,
773 		struct dentry *dentry)
774 {
775 	int err;
776 	struct p9_fid *dfid, *oldfid;
777 	struct v9fs_session_info *v9ses;
778 
779 	p9_debug(P9_DEBUG_VFS, "dir ino: %lu, old_name: %pd, new_name: %pd\n",
780 		 dir->i_ino, old_dentry, dentry);
781 
782 	v9ses = v9fs_inode2v9ses(dir);
783 	dfid = v9fs_parent_fid(dentry);
784 	if (IS_ERR(dfid))
785 		return PTR_ERR(dfid);
786 
787 	oldfid = v9fs_fid_lookup(old_dentry);
788 	if (IS_ERR(oldfid)) {
789 		p9_fid_put(dfid);
790 		return PTR_ERR(oldfid);
791 	}
792 
793 	err = p9_client_link(dfid, oldfid, dentry->d_name.name);
794 
795 	p9_fid_put(dfid);
796 	p9_fid_put(oldfid);
797 	if (err < 0) {
798 		p9_debug(P9_DEBUG_VFS, "p9_client_link failed %d\n", err);
799 		return err;
800 	}
801 
802 	v9fs_invalidate_inode_attr(dir);
803 	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
804 		/* Get the latest stat info from server. */
805 		struct p9_fid *fid;
806 
807 		fid = v9fs_fid_lookup(old_dentry);
808 		if (IS_ERR(fid))
809 			return PTR_ERR(fid);
810 
811 		v9fs_refresh_inode_dotl(fid, d_inode(old_dentry));
812 		p9_fid_put(fid);
813 	}
814 	ihold(d_inode(old_dentry));
815 	d_instantiate(dentry, d_inode(old_dentry));
816 
817 	return err;
818 }
819 
820 /**
821  * v9fs_vfs_mknod_dotl - create a special file
822  * @mnt_userns: The user namespace of the mount
823  * @dir: inode destination for new link
824  * @dentry: dentry for file
825  * @omode: mode for creation
826  * @rdev: device associated with special file
827  *
828  */
829 static int
v9fs_vfs_mknod_dotl(struct user_namespace * mnt_userns,struct inode * dir,struct dentry * dentry,umode_t omode,dev_t rdev)830 v9fs_vfs_mknod_dotl(struct user_namespace *mnt_userns, struct inode *dir,
831 		    struct dentry *dentry, umode_t omode, dev_t rdev)
832 {
833 	int err;
834 	kgid_t gid;
835 	const unsigned char *name;
836 	umode_t mode;
837 	struct v9fs_session_info *v9ses;
838 	struct p9_fid *fid = NULL, *dfid = NULL;
839 	struct inode *inode;
840 	struct p9_qid qid;
841 	struct posix_acl *dacl = NULL, *pacl = NULL;
842 
843 	p9_debug(P9_DEBUG_VFS, " %lu,%pd mode: %x MAJOR: %u MINOR: %u\n",
844 		 dir->i_ino, dentry, omode,
845 		 MAJOR(rdev), MINOR(rdev));
846 
847 	v9ses = v9fs_inode2v9ses(dir);
848 	dfid = v9fs_parent_fid(dentry);
849 	if (IS_ERR(dfid)) {
850 		err = PTR_ERR(dfid);
851 		p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
852 		goto error;
853 	}
854 
855 	gid = v9fs_get_fsgid_for_create(dir);
856 	mode = omode;
857 	/* Update mode based on ACL value */
858 	err = v9fs_acl_mode(dir, &mode, &dacl, &pacl);
859 	if (err) {
860 		p9_debug(P9_DEBUG_VFS, "Failed to get acl values in mknod %d\n",
861 			 err);
862 		goto error;
863 	}
864 	name = dentry->d_name.name;
865 
866 	err = p9_client_mknod_dotl(dfid, name, mode, rdev, gid, &qid);
867 	if (err < 0)
868 		goto error;
869 
870 	v9fs_invalidate_inode_attr(dir);
871 	fid = p9_client_walk(dfid, 1, &name, 1);
872 	if (IS_ERR(fid)) {
873 		err = PTR_ERR(fid);
874 		p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n",
875 			 err);
876 		goto error;
877 	}
878 
879 	/* instantiate inode and assign the unopened fid to the dentry */
880 	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
881 		inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
882 		if (IS_ERR(inode)) {
883 			err = PTR_ERR(inode);
884 			p9_debug(P9_DEBUG_VFS, "inode creation failed %d\n",
885 				 err);
886 			goto error;
887 		}
888 		v9fs_set_create_acl(inode, fid, dacl, pacl);
889 		v9fs_fid_add(dentry, &fid);
890 		d_instantiate(dentry, inode);
891 		err = 0;
892 	} else {
893 		/*
894 		 * Not in cached mode. No need to populate inode with stat.
895 		 * socket syscall returns a fd, so we need instantiate
896 		 */
897 		inode = v9fs_get_inode(dir->i_sb, mode, rdev);
898 		if (IS_ERR(inode)) {
899 			err = PTR_ERR(inode);
900 			goto error;
901 		}
902 		v9fs_set_create_acl(inode, fid, dacl, pacl);
903 		d_instantiate(dentry, inode);
904 	}
905 error:
906 	p9_fid_put(fid);
907 	v9fs_put_acl(dacl, pacl);
908 	p9_fid_put(dfid);
909 
910 	return err;
911 }
912 
913 /**
914  * v9fs_vfs_get_link_dotl - follow a symlink path
915  * @dentry: dentry for symlink
916  * @inode: inode for symlink
917  * @done: destructor for return value
918  */
919 
920 static const char *
v9fs_vfs_get_link_dotl(struct dentry * dentry,struct inode * inode,struct delayed_call * done)921 v9fs_vfs_get_link_dotl(struct dentry *dentry,
922 		       struct inode *inode,
923 		       struct delayed_call *done)
924 {
925 	struct p9_fid *fid;
926 	char *target;
927 	int retval;
928 
929 	if (!dentry)
930 		return ERR_PTR(-ECHILD);
931 
932 	p9_debug(P9_DEBUG_VFS, "%pd\n", dentry);
933 
934 	fid = v9fs_fid_lookup(dentry);
935 	if (IS_ERR(fid))
936 		return ERR_CAST(fid);
937 	retval = p9_client_readlink(fid, &target);
938 	p9_fid_put(fid);
939 	if (retval)
940 		return ERR_PTR(retval);
941 	set_delayed_call(done, kfree_link, target);
942 	return target;
943 }
944 
v9fs_refresh_inode_dotl(struct p9_fid * fid,struct inode * inode)945 int v9fs_refresh_inode_dotl(struct p9_fid *fid, struct inode *inode)
946 {
947 	struct p9_stat_dotl *st;
948 	struct v9fs_session_info *v9ses;
949 	unsigned int flags;
950 
951 	v9ses = v9fs_inode2v9ses(inode);
952 	st = p9_client_getattr_dotl(fid, P9_STATS_ALL);
953 	if (IS_ERR(st))
954 		return PTR_ERR(st);
955 	/*
956 	 * Don't update inode if the file type is different
957 	 */
958 	if (inode_wrong_type(inode, st->st_mode))
959 		goto out;
960 
961 	/*
962 	 * We don't want to refresh inode->i_size,
963 	 * because we may have cached data
964 	 */
965 	flags = (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) ?
966 		V9FS_STAT2INODE_KEEP_ISIZE : 0;
967 	v9fs_stat2inode_dotl(st, inode, flags);
968 out:
969 	kfree(st);
970 	return 0;
971 }
972 
973 const struct inode_operations v9fs_dir_inode_operations_dotl = {
974 	.create = v9fs_vfs_create_dotl,
975 	.atomic_open = v9fs_vfs_atomic_open_dotl,
976 	.lookup = v9fs_vfs_lookup,
977 	.link = v9fs_vfs_link_dotl,
978 	.symlink = v9fs_vfs_symlink_dotl,
979 	.unlink = v9fs_vfs_unlink,
980 	.mkdir = v9fs_vfs_mkdir_dotl,
981 	.rmdir = v9fs_vfs_rmdir,
982 	.mknod = v9fs_vfs_mknod_dotl,
983 	.rename = v9fs_vfs_rename,
984 	.getattr = v9fs_vfs_getattr_dotl,
985 	.setattr = v9fs_vfs_setattr_dotl,
986 	.listxattr = v9fs_listxattr,
987 	.get_acl = v9fs_iop_get_acl,
988 };
989 
990 const struct inode_operations v9fs_file_inode_operations_dotl = {
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_symlink_inode_operations_dotl = {
998 	.get_link = v9fs_vfs_get_link_dotl,
999 	.getattr = v9fs_vfs_getattr_dotl,
1000 	.setattr = v9fs_vfs_setattr_dotl,
1001 	.listxattr = v9fs_listxattr,
1002 };
1003