xref: /linux/fs/nfs/inode.c (revision 840ef6c78e6a2f694b578ecb9063241c992aaa9e)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  linux/fs/nfs/inode.c
4  *
5  *  Copyright (C) 1992  Rick Sladkey
6  *
7  *  nfs inode and superblock handling functions
8  *
9  *  Modularised by Alan Cox <alan@lxorguk.ukuu.org.uk>, while hacking some
10  *  experimental NFS changes. Modularisation taken straight from SYS5 fs.
11  *
12  *  Change to nfs_read_super() to permit NFS mounts to multi-homed hosts.
13  *  J.S.Peatfield@damtp.cam.ac.uk
14  *
15  */
16 
17 #include <linux/module.h>
18 #include <linux/init.h>
19 #include <linux/sched/signal.h>
20 #include <linux/time.h>
21 #include <linux/kernel.h>
22 #include <linux/mm.h>
23 #include <linux/string.h>
24 #include <linux/stat.h>
25 #include <linux/errno.h>
26 #include <linux/unistd.h>
27 #include <linux/sunrpc/clnt.h>
28 #include <linux/sunrpc/stats.h>
29 #include <linux/sunrpc/metrics.h>
30 #include <linux/nfs_fs.h>
31 #include <linux/nfs_mount.h>
32 #include <linux/nfs4_mount.h>
33 #include <linux/lockd/bind.h>
34 #include <linux/seq_file.h>
35 #include <linux/mount.h>
36 #include <linux/vfs.h>
37 #include <linux/inet.h>
38 #include <linux/nfs_xdr.h>
39 #include <linux/slab.h>
40 #include <linux/compat.h>
41 #include <linux/freezer.h>
42 #include <linux/uaccess.h>
43 #include <linux/iversion.h>
44 #include <linux/fileattr.h>
45 
46 #include "nfs4_fs.h"
47 #include "callback.h"
48 #include "delegation.h"
49 #include "iostat.h"
50 #include "internal.h"
51 #include "fscache.h"
52 #include "pnfs.h"
53 #include "nfs.h"
54 #include "netns.h"
55 #include "sysfs.h"
56 
57 #include "nfstrace.h"
58 
59 #define NFSDBG_FACILITY		NFSDBG_VFS
60 
61 static bool enable_ino64;
62 
63 static int param_set_enable_ino64(const char *val, const struct kernel_param *kp)
64 {
65 	pr_notice("enable_ino64 is deprecated and has no effect\n");
66 	return 0;
67 }
68 
69 static const struct kernel_param_ops param_ops_enable_ino64 = {
70 	.set = param_set_enable_ino64,
71 	.get = param_get_bool,
72 };
73 
74 static int nfs_update_inode(struct inode *, struct nfs_fattr *);
75 
76 static struct kmem_cache * nfs_inode_cachep;
77 
78 int nfs_wait_bit_killable(struct wait_bit_key *key, int mode)
79 {
80 	if (unlikely(nfs_current_task_exiting()))
81 		return -EINTR;
82 	schedule();
83 	if (signal_pending_state(mode, current))
84 		return -ERESTARTSYS;
85 	return 0;
86 }
87 EXPORT_SYMBOL_GPL(nfs_wait_bit_killable);
88 
89 int nfs_drop_inode(struct inode *inode)
90 {
91 	return NFS_STALE(inode) || inode_generic_drop(inode);
92 }
93 EXPORT_SYMBOL_GPL(nfs_drop_inode);
94 
95 void nfs_clear_inode(struct inode *inode)
96 {
97 	/*
98 	 * The following should never happen...
99 	 */
100 	WARN_ON_ONCE(nfs_have_writebacks(inode));
101 	WARN_ON_ONCE(!list_empty(&NFS_I(inode)->open_files));
102 	nfs_zap_acl_cache(inode);
103 	nfs_access_zap_cache(inode);
104 	nfs_fscache_clear_inode(inode);
105 }
106 EXPORT_SYMBOL_GPL(nfs_clear_inode);
107 
108 void nfs_evict_inode(struct inode *inode)
109 {
110 	truncate_inode_pages_final(&inode->i_data);
111 	clear_inode(inode);
112 	nfs_clear_inode(inode);
113 }
114 
115 int nfs_sync_inode(struct inode *inode)
116 {
117 	inode_dio_wait(inode);
118 	return nfs_wb_all(inode);
119 }
120 EXPORT_SYMBOL_GPL(nfs_sync_inode);
121 
122 /**
123  * nfs_sync_mapping - helper to flush all mmapped dirty data to disk
124  * @mapping: pointer to struct address_space
125  */
126 int nfs_sync_mapping(struct address_space *mapping)
127 {
128 	int ret = 0;
129 
130 	if (mapping->nrpages != 0) {
131 		unmap_mapping_range(mapping, 0, 0, 0);
132 		ret = nfs_wb_all(mapping->host);
133 	}
134 	return ret;
135 }
136 
137 static int nfs_attribute_timeout(struct inode *inode)
138 {
139 	struct nfs_inode *nfsi = NFS_I(inode);
140 
141 	return !time_in_range_open(jiffies, nfsi->read_cache_jiffies, nfsi->read_cache_jiffies + nfsi->attrtimeo);
142 }
143 
144 static bool nfs_check_cache_flags_invalid(struct inode *inode,
145 					  unsigned long flags)
146 {
147 	unsigned long cache_validity = READ_ONCE(NFS_I(inode)->cache_validity);
148 
149 	return (cache_validity & flags) != 0;
150 }
151 
152 bool nfs_check_cache_invalid(struct inode *inode, unsigned long flags)
153 {
154 	if (nfs_check_cache_flags_invalid(inode, flags))
155 		return true;
156 	return nfs_attribute_cache_expired(inode);
157 }
158 EXPORT_SYMBOL_GPL(nfs_check_cache_invalid);
159 
160 #ifdef CONFIG_NFS_V4_2
161 static bool nfs_has_xattr_cache(const struct nfs_inode *nfsi)
162 {
163 	return nfsi->xattr_cache != NULL;
164 }
165 #else
166 static bool nfs_has_xattr_cache(const struct nfs_inode *nfsi)
167 {
168 	return false;
169 }
170 #endif
171 
172 void nfs_set_cache_invalid(struct inode *inode, unsigned long flags)
173 {
174 	struct nfs_inode *nfsi = NFS_I(inode);
175 
176 	if (nfs_have_delegated_attributes(inode)) {
177 		if (!(flags & NFS_INO_REVAL_FORCED))
178 			flags &= ~(NFS_INO_INVALID_MODE |
179 				   NFS_INO_INVALID_OTHER |
180 				   NFS_INO_INVALID_BTIME |
181 				   NFS_INO_INVALID_XATTR);
182 		flags &= ~(NFS_INO_INVALID_CHANGE | NFS_INO_INVALID_SIZE);
183 	}
184 
185 	if (!nfs_has_xattr_cache(nfsi))
186 		flags &= ~NFS_INO_INVALID_XATTR;
187 	if (flags & NFS_INO_INVALID_DATA)
188 		nfs_fscache_invalidate(inode, 0);
189 	flags &= ~NFS_INO_REVAL_FORCED;
190 
191 	flags |= nfsi->cache_validity;
192 	if (inode->i_mapping->nrpages == 0)
193 		flags &= ~NFS_INO_INVALID_DATA;
194 
195 	/* pairs with nfs_clear_invalid_mapping()'s smp_load_acquire() */
196 	smp_store_release(&nfsi->cache_validity, flags);
197 
198 	if (inode->i_mapping->nrpages == 0 ||
199 	    nfsi->cache_validity & NFS_INO_INVALID_DATA) {
200 		nfs_ooo_clear(nfsi);
201 	}
202 	trace_nfs_set_cache_invalid(inode, 0);
203 }
204 EXPORT_SYMBOL_GPL(nfs_set_cache_invalid);
205 
206 /*
207  * Invalidate the local caches
208  */
209 static void nfs_zap_caches_locked(struct inode *inode)
210 {
211 	struct nfs_inode *nfsi = NFS_I(inode);
212 	int mode = inode->i_mode;
213 
214 	nfs_inc_stats(inode, NFSIOS_ATTRINVALIDATE);
215 
216 	nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
217 	nfsi->attrtimeo_timestamp = jiffies;
218 
219 	if (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))
220 		nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR |
221 						     NFS_INO_INVALID_DATA |
222 						     NFS_INO_INVALID_ACCESS |
223 						     NFS_INO_INVALID_ACL |
224 						     NFS_INO_INVALID_XATTR);
225 	else
226 		nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR |
227 						     NFS_INO_INVALID_ACCESS |
228 						     NFS_INO_INVALID_ACL |
229 						     NFS_INO_INVALID_XATTR);
230 	nfs_zap_label_cache_locked(nfsi);
231 }
232 
233 void nfs_zap_caches(struct inode *inode)
234 {
235 	spin_lock(&inode->i_lock);
236 	nfs_zap_caches_locked(inode);
237 	spin_unlock(&inode->i_lock);
238 }
239 
240 void nfs_zap_mapping(struct inode *inode, struct address_space *mapping)
241 {
242 	if (mapping->nrpages != 0) {
243 		spin_lock(&inode->i_lock);
244 		nfs_set_cache_invalid(inode, NFS_INO_INVALID_DATA);
245 		spin_unlock(&inode->i_lock);
246 	}
247 }
248 
249 void nfs_zap_acl_cache(struct inode *inode)
250 {
251 	void (*clear_acl_cache)(struct inode *);
252 
253 	clear_acl_cache = NFS_PROTO(inode)->clear_acl_cache;
254 	if (clear_acl_cache != NULL)
255 		clear_acl_cache(inode);
256 	spin_lock(&inode->i_lock);
257 	NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_ACL;
258 	spin_unlock(&inode->i_lock);
259 }
260 EXPORT_SYMBOL_GPL(nfs_zap_acl_cache);
261 
262 void nfs_invalidate_atime(struct inode *inode)
263 {
264 	if (nfs_have_delegated_atime(inode))
265 		return;
266 	spin_lock(&inode->i_lock);
267 	nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATIME);
268 	spin_unlock(&inode->i_lock);
269 }
270 EXPORT_SYMBOL_GPL(nfs_invalidate_atime);
271 
272 /*
273  * Invalidate, but do not unhash, the inode.
274  * NB: must be called with inode->i_lock held!
275  */
276 static void nfs_set_inode_stale_locked(struct inode *inode)
277 {
278 	set_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
279 	nfs_zap_caches_locked(inode);
280 	trace_nfs_set_inode_stale(inode);
281 }
282 
283 void nfs_set_inode_stale(struct inode *inode)
284 {
285 	spin_lock(&inode->i_lock);
286 	nfs_set_inode_stale_locked(inode);
287 	spin_unlock(&inode->i_lock);
288 }
289 
290 struct nfs_find_desc {
291 	struct nfs_fh		*fh;
292 	struct nfs_fattr	*fattr;
293 };
294 
295 /*
296  * For re-exported directories (also seen in NFSv2)
297  * we are forced to allow 2 different inodes to have the same
298  * i_ino.
299  */
300 static int
301 nfs_find_actor(struct inode *inode, void *opaque)
302 {
303 	struct nfs_find_desc	*desc = opaque;
304 	struct nfs_fh		*fh = desc->fh;
305 	struct nfs_fattr	*fattr = desc->fattr;
306 
307 	if (inode->i_ino != fattr->fileid)
308 		return 0;
309 	if (inode_wrong_type(inode, fattr->mode))
310 		return 0;
311 	if (nfs_compare_fh(NFS_FH(inode), fh))
312 		return 0;
313 	if (is_bad_inode(inode) || NFS_STALE(inode))
314 		return 0;
315 	return 1;
316 }
317 
318 static int
319 nfs_init_locked(struct inode *inode, void *opaque)
320 {
321 	struct nfs_find_desc	*desc = opaque;
322 	struct nfs_fattr	*fattr = desc->fattr;
323 
324 	inode->i_ino = fattr->fileid;
325 	inode->i_mode = fattr->mode;
326 	nfs_copy_fh(NFS_FH(inode), desc->fh);
327 	return 0;
328 }
329 
330 #ifdef CONFIG_NFS_V4_SECURITY_LABEL
331 static void nfs_clear_label_invalid(struct inode *inode)
332 {
333 	spin_lock(&inode->i_lock);
334 	NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_LABEL;
335 	spin_unlock(&inode->i_lock);
336 }
337 
338 void nfs_setsecurity(struct inode *inode, struct nfs_fattr *fattr)
339 {
340 	int error;
341 
342 	if (fattr->label == NULL)
343 		return;
344 
345 	if ((fattr->valid & NFS_ATTR_FATTR_V4_SECURITY_LABEL) && inode->i_security) {
346 		error = security_inode_notifysecctx(inode, fattr->label->label,
347 				fattr->label->len);
348 		if (error)
349 			printk(KERN_ERR "%s() %s %d "
350 					"security_inode_notifysecctx() %d\n",
351 					__func__,
352 					(char *)fattr->label->label,
353 					fattr->label->len, error);
354 		nfs_clear_label_invalid(inode);
355 	}
356 }
357 
358 struct nfs4_label *nfs4_label_alloc(struct nfs_server *server, gfp_t flags)
359 {
360 	struct nfs4_label *label;
361 
362 	if (!(server->caps & NFS_CAP_SECURITY_LABEL))
363 		return NULL;
364 
365 	label = kzalloc_obj(struct nfs4_label, flags);
366 	if (label == NULL)
367 		return ERR_PTR(-ENOMEM);
368 
369 	label->label = kzalloc(NFS4_MAXLABELLEN, flags);
370 	if (label->label == NULL) {
371 		kfree(label);
372 		return ERR_PTR(-ENOMEM);
373 	}
374 	label->len = NFS4_MAXLABELLEN;
375 
376 	return label;
377 }
378 EXPORT_SYMBOL_GPL(nfs4_label_alloc);
379 #else
380 void nfs_setsecurity(struct inode *inode, struct nfs_fattr *fattr)
381 {
382 }
383 #endif
384 EXPORT_SYMBOL_GPL(nfs_setsecurity);
385 
386 /* Search for inode identified by fh, fileid and i_mode in inode cache. */
387 struct inode *
388 nfs_ilookup(struct super_block *sb, struct nfs_fattr *fattr, struct nfs_fh *fh)
389 {
390 	struct nfs_find_desc desc = {
391 		.fh	= fh,
392 		.fattr	= fattr,
393 	};
394 	struct inode *inode;
395 	u64 hash;
396 
397 	if (!(fattr->valid & NFS_ATTR_FATTR_FILEID) ||
398 	    !(fattr->valid & NFS_ATTR_FATTR_TYPE))
399 		return NULL;
400 
401 	hash = fattr->fileid;
402 	inode = ilookup5(sb, hash, nfs_find_actor, &desc);
403 
404 	dprintk("%s: returning %p\n", __func__, inode);
405 	return inode;
406 }
407 
408 static void nfs_inode_init_regular(struct nfs_inode *nfsi)
409 {
410 	atomic_long_set(&nfsi->nrequests, 0);
411 	atomic_long_set(&nfsi->redirtied_pages, 0);
412 	INIT_LIST_HEAD(&nfsi->commit_info.list);
413 	atomic_long_set(&nfsi->commit_info.ncommit, 0);
414 	atomic_set(&nfsi->commit_info.rpcs_out, 0);
415 	mutex_init(&nfsi->commit_mutex);
416 }
417 
418 static void nfs_inode_init_dir(struct nfs_inode *nfsi)
419 {
420 	nfsi->cache_change_attribute = 0;
421 	memset(nfsi->cookieverf, 0, sizeof(nfsi->cookieverf));
422 	init_rwsem(&nfsi->rmdir_sem);
423 }
424 
425 /*
426  * This is our front-end to iget that looks up inodes by file handle
427  * instead of inode number.
428  */
429 struct inode *
430 nfs_fhget(struct super_block *sb, struct nfs_fh *fh, struct nfs_fattr *fattr)
431 {
432 	struct nfs_find_desc desc = {
433 		.fh	= fh,
434 		.fattr	= fattr
435 	};
436 	struct inode *inode = ERR_PTR(-ENOENT);
437 	u64 fattr_supported = NFS_SB(sb)->fattr_valid;
438 	u64 hash;
439 
440 	nfs_attr_check_mountpoint(sb, fattr);
441 
442 	if (nfs_attr_use_mounted_on_fileid(fattr))
443 		fattr->fileid = fattr->mounted_on_fileid;
444 	else if ((fattr->valid & NFS_ATTR_FATTR_FILEID) == 0)
445 		goto out_no_inode;
446 	if ((fattr->valid & NFS_ATTR_FATTR_TYPE) == 0)
447 		goto out_no_inode;
448 
449 	hash = fattr->fileid;
450 
451 	inode = iget5_locked(sb, hash, nfs_find_actor, nfs_init_locked, &desc);
452 	if (inode == NULL) {
453 		inode = ERR_PTR(-ENOMEM);
454 		goto out_no_inode;
455 	}
456 
457 	if (inode_state_read_once(inode) & I_NEW) {
458 		struct nfs_inode *nfsi = NFS_I(inode);
459 		unsigned long now = jiffies;
460 
461 		/* We can't support update_atime(), since the server will reset it */
462 		inode->i_flags |= S_NOATIME|S_NOCMTIME;
463 		inode->i_mode = fattr->mode;
464 		nfsi->cache_validity = 0;
465 		if ((fattr->valid & NFS_ATTR_FATTR_MODE) == 0
466 				&& (fattr_supported & NFS_ATTR_FATTR_MODE))
467 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_MODE);
468 		/* Why so? Because we want revalidate for devices/FIFOs, and
469 		 * that's precisely what we have in nfs_file_inode_operations.
470 		 */
471 		inode->i_op = NFS_SB(sb)->nfs_client->rpc_ops->file_inode_ops;
472 		if (S_ISREG(inode->i_mode)) {
473 			inode->i_fop = NFS_SB(sb)->nfs_client->rpc_ops->file_ops;
474 			inode->i_data.a_ops = &nfs_file_aops;
475 			nfs_inode_init_regular(nfsi);
476 			mapping_set_large_folios(inode->i_mapping);
477 		} else if (S_ISDIR(inode->i_mode)) {
478 			inode->i_op = NFS_SB(sb)->nfs_client->rpc_ops->dir_inode_ops;
479 			inode->i_fop = &nfs_dir_operations;
480 			inode->i_data.a_ops = &nfs_dir_aops;
481 			nfs_inode_init_dir(nfsi);
482 			/* Deal with crossing mountpoints */
483 			if (fattr->valid & NFS_ATTR_FATTR_MOUNTPOINT ||
484 					fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL) {
485 				if (fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL)
486 					inode->i_op = &nfs_referral_inode_operations;
487 				else
488 					inode->i_op = &nfs_mountpoint_inode_operations;
489 				inode->i_fop = NULL;
490 				inode->i_flags |= S_AUTOMOUNT;
491 			}
492 		} else if (S_ISLNK(inode->i_mode)) {
493 			inode->i_op = &nfs_symlink_inode_operations;
494 			inode_nohighmem(inode);
495 		} else
496 			init_special_inode(inode, inode->i_mode, fattr->rdev);
497 
498 		inode_set_atime(inode, 0, 0);
499 		inode_set_mtime(inode, 0, 0);
500 		inode_set_ctime(inode, 0, 0);
501 		memset(&nfsi->btime, 0, sizeof(nfsi->btime));
502 		inode_set_iversion_raw(inode, 0);
503 		inode->i_size = 0;
504 		clear_nlink(inode);
505 		inode->i_uid = make_kuid(&init_user_ns, -2);
506 		inode->i_gid = make_kgid(&init_user_ns, -2);
507 		inode->i_blocks = 0;
508 		nfsi->write_io = 0;
509 		nfsi->read_io = 0;
510 
511 		nfsi->read_cache_jiffies = fattr->time_start;
512 		nfsi->attr_gencount = fattr->gencount;
513 		if (fattr->valid & NFS_ATTR_FATTR_ATIME)
514 			inode_set_atime_to_ts(inode, fattr->atime);
515 		else if (fattr_supported & NFS_ATTR_FATTR_ATIME)
516 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATIME);
517 		if (fattr->valid & NFS_ATTR_FATTR_MTIME)
518 			inode_set_mtime_to_ts(inode, fattr->mtime);
519 		else if (fattr_supported & NFS_ATTR_FATTR_MTIME)
520 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_MTIME);
521 		if (fattr->valid & NFS_ATTR_FATTR_CTIME)
522 			inode_set_ctime_to_ts(inode, fattr->ctime);
523 		else if (fattr_supported & NFS_ATTR_FATTR_CTIME)
524 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_CTIME);
525 		if (fattr->valid & NFS_ATTR_FATTR_BTIME)
526 			nfsi->btime = fattr->btime;
527 		else if (fattr_supported & NFS_ATTR_FATTR_BTIME)
528 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_BTIME);
529 		if (fattr->valid & NFS_ATTR_FATTR_CHANGE)
530 			inode_set_iversion_raw(inode, fattr->change_attr);
531 		else
532 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_CHANGE);
533 		if (fattr->valid & NFS_ATTR_FATTR_SIZE)
534 			inode->i_size = nfs_size_to_loff_t(fattr->size);
535 		else
536 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_SIZE);
537 		if (fattr->valid & NFS_ATTR_FATTR_NLINK)
538 			set_nlink(inode, fattr->nlink);
539 		else if (fattr_supported & NFS_ATTR_FATTR_NLINK)
540 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_NLINK);
541 		else
542 			set_nlink(inode, 1);
543 		if (fattr->valid & NFS_ATTR_FATTR_OWNER)
544 			inode->i_uid = fattr->uid;
545 		else if (fattr_supported & NFS_ATTR_FATTR_OWNER)
546 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_OTHER);
547 		if (fattr->valid & NFS_ATTR_FATTR_GROUP)
548 			inode->i_gid = fattr->gid;
549 		else if (fattr_supported & NFS_ATTR_FATTR_GROUP)
550 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_OTHER);
551 		if (fattr->valid & NFS_ATTR_FATTR_BLOCKS_USED)
552 			inode->i_blocks = fattr->du.nfs2.blocks;
553 		else if (fattr_supported & NFS_ATTR_FATTR_BLOCKS_USED &&
554 			 fattr->size != 0)
555 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_BLOCKS);
556 		if (fattr->valid & NFS_ATTR_FATTR_SPACE_USED) {
557 			/*
558 			 * report the blocks in 512byte units
559 			 */
560 			inode->i_blocks = nfs_calc_block_size(fattr->du.nfs3.used);
561 		} else if (fattr_supported & NFS_ATTR_FATTR_SPACE_USED &&
562 			   fattr->size != 0)
563 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_BLOCKS);
564 
565 		nfs_setsecurity(inode, fattr);
566 
567 		nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
568 		nfsi->attrtimeo_timestamp = now;
569 		nfsi->access_cache = RB_ROOT;
570 
571 		nfs_fscache_init_inode(inode);
572 
573 		unlock_new_inode(inode);
574 	} else {
575 		int err = nfs_refresh_inode(inode, fattr);
576 		if (err < 0) {
577 			iput(inode);
578 			inode = ERR_PTR(err);
579 			goto out_no_inode;
580 		}
581 	}
582 	dprintk("NFS: nfs_fhget(%s/%Lu fh_crc=0x%08x ct=%d)\n",
583 		inode->i_sb->s_id,
584 		(unsigned long long)inode->i_ino,
585 		nfs_display_fhandle_hash(fh),
586 		icount_read_once(inode));
587 
588 out:
589 	return inode;
590 
591 out_no_inode:
592 	dprintk("nfs_fhget: iget failed with error %ld\n", PTR_ERR(inode));
593 	goto out;
594 }
595 EXPORT_SYMBOL_GPL(nfs_fhget);
596 
597 static void
598 nfs_fattr_fixup_delegated(struct inode *inode, struct nfs_fattr *fattr)
599 {
600 	unsigned long cache_validity = NFS_I(inode)->cache_validity;
601 
602 	if (nfs_have_delegated_mtime(inode)) {
603 		if (!(cache_validity & NFS_INO_INVALID_CTIME))
604 			fattr->valid &= ~(NFS_ATTR_FATTR_PRECTIME |
605 					  NFS_ATTR_FATTR_CTIME);
606 
607 		if (!(cache_validity & NFS_INO_INVALID_MTIME))
608 			fattr->valid &= ~(NFS_ATTR_FATTR_PREMTIME |
609 					  NFS_ATTR_FATTR_MTIME);
610 
611 		if (!(cache_validity & NFS_INO_INVALID_ATIME))
612 			fattr->valid &= ~NFS_ATTR_FATTR_ATIME;
613 	} else if (nfs_have_delegated_atime(inode)) {
614 		if (!(cache_validity & NFS_INO_INVALID_ATIME))
615 			fattr->valid &= ~NFS_ATTR_FATTR_ATIME;
616 	}
617 }
618 
619 static void nfs_set_timestamps_to_ts(struct inode *inode, struct iattr *attr)
620 {
621 	unsigned int cache_flags = 0;
622 
623 	if (attr->ia_valid & ATTR_MTIME_SET) {
624 		struct timespec64 ctime = inode_get_ctime(inode);
625 		struct timespec64 mtime = inode_get_mtime(inode);
626 		struct timespec64 now;
627 		bool updated = false;
628 
629 		now = inode_set_ctime_current(inode);
630 		if (!timespec64_equal(&now, &ctime))
631 			updated = true;
632 
633 		inode_set_mtime_to_ts(inode, attr->ia_mtime);
634 		if (!timespec64_equal(&now, &mtime))
635 			updated = true;
636 
637 		inode_maybe_inc_iversion(inode, updated);
638 		cache_flags |= NFS_INO_INVALID_CTIME | NFS_INO_INVALID_MTIME;
639 	}
640 	if (attr->ia_valid & ATTR_ATIME_SET) {
641 		inode_set_atime_to_ts(inode, attr->ia_atime);
642 		cache_flags |= NFS_INO_INVALID_ATIME;
643 	}
644 	NFS_I(inode)->cache_validity &= ~cache_flags;
645 }
646 
647 static void nfs_update_atime(struct inode *inode)
648 {
649 	inode_update_time(inode, FS_UPD_ATIME, 0);
650 	NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_ATIME;
651 }
652 
653 static void nfs_update_mtime(struct inode *inode)
654 {
655 	inode_update_time(inode, FS_UPD_CMTIME, 0);
656 	NFS_I(inode)->cache_validity &=
657 		~(NFS_INO_INVALID_CTIME | NFS_INO_INVALID_MTIME);
658 }
659 
660 void nfs_update_delegated_atime(struct inode *inode)
661 {
662 	spin_lock(&inode->i_lock);
663 	if (nfs_have_delegated_atime(inode))
664 		nfs_update_atime(inode);
665 	spin_unlock(&inode->i_lock);
666 }
667 
668 void nfs_update_delegated_mtime_locked(struct inode *inode)
669 {
670 	if (nfs_have_delegated_mtime(inode) ||
671 	    nfs_have_directory_delegation(inode))
672 		nfs_update_mtime(inode);
673 }
674 
675 void nfs_update_delegated_mtime(struct inode *inode)
676 {
677 	spin_lock(&inode->i_lock);
678 	nfs_update_delegated_mtime_locked(inode);
679 	spin_unlock(&inode->i_lock);
680 }
681 EXPORT_SYMBOL_GPL(nfs_update_delegated_mtime);
682 
683 #define NFS_VALID_ATTRS (ATTR_MODE|ATTR_UID|ATTR_GID|ATTR_SIZE|ATTR_ATIME|ATTR_ATIME_SET|ATTR_MTIME|ATTR_MTIME_SET|ATTR_FILE|ATTR_OPEN)
684 
685 int
686 nfs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
687 	    struct iattr *attr)
688 {
689 	struct inode *inode = d_inode(dentry);
690 	struct nfs_fattr *fattr;
691 	loff_t oldsize;
692 	int error = 0;
693 	kuid_t task_uid = current_fsuid();
694 	kuid_t owner_uid = inode->i_uid;
695 
696 	nfs_inc_stats(inode, NFSIOS_VFSSETATTR);
697 
698 	/* skip mode change if it's just for clearing setuid/setgid */
699 	if (attr->ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
700 		attr->ia_valid &= ~ATTR_MODE;
701 
702 	if (S_ISREG(inode->i_mode))
703 		nfs_file_block_o_direct(NFS_I(inode));
704 
705 	oldsize = i_size_read(inode);
706 	if (attr->ia_valid & ATTR_SIZE) {
707 		BUG_ON(!S_ISREG(inode->i_mode));
708 
709 		error = inode_newsize_ok(inode, attr->ia_size);
710 		if (error)
711 			return error;
712 
713 		if (attr->ia_size == oldsize)
714 			attr->ia_valid &= ~ATTR_SIZE;
715 	}
716 
717 	if (nfs_have_delegated_mtime(inode) && attr->ia_valid & ATTR_MTIME) {
718 		spin_lock(&inode->i_lock);
719 		if (attr->ia_valid & ATTR_MTIME_SET) {
720 			if (uid_eq(task_uid, owner_uid)) {
721 				nfs_set_timestamps_to_ts(inode, attr);
722 				attr->ia_valid &= ~(ATTR_MTIME|ATTR_MTIME_SET|
723 						ATTR_ATIME|ATTR_ATIME_SET);
724 			}
725 		} else {
726 			if (attr->ia_valid & ATTR_MTIME)
727 				nfs_update_mtime(inode);
728 			if (attr->ia_valid & ATTR_ATIME)
729 				nfs_update_atime(inode);
730 			attr->ia_valid &= ~(ATTR_MTIME|ATTR_ATIME);
731 		}
732 		spin_unlock(&inode->i_lock);
733 	} else if (nfs_have_delegated_atime(inode) &&
734 		   attr->ia_valid & ATTR_ATIME &&
735 		   !(attr->ia_valid & ATTR_MTIME)) {
736 		if (!(attr->ia_valid & ATTR_ATIME_SET)) {
737 			nfs_update_delegated_atime(inode);
738 			attr->ia_valid &= ~ATTR_ATIME;
739 		}
740 	}
741 
742 	/* Optimization: if the end result is no change, don't RPC */
743 	if (((attr->ia_valid & NFS_VALID_ATTRS) & ~(ATTR_FILE|ATTR_OPEN)) == 0)
744 		return 0;
745 
746 	trace_nfs_setattr_enter(inode);
747 
748 	/* Write all dirty data */
749 	if (S_ISREG(inode->i_mode))
750 		nfs_sync_inode(inode);
751 
752 	fattr = nfs_alloc_fattr_with_label(NFS_SERVER(inode));
753 	if (fattr == NULL) {
754 		error = -ENOMEM;
755 		goto out;
756 	}
757 
758 	error = NFS_PROTO(inode)->setattr(dentry, fattr, attr);
759 	if (error == 0) {
760 		if (attr->ia_valid & ATTR_SIZE)
761 			nfs_truncate_last_folio(inode->i_mapping, oldsize,
762 						attr->ia_size);
763 		error = nfs_refresh_inode(inode, fattr);
764 	}
765 	nfs_free_fattr(fattr);
766 out:
767 	trace_nfs_setattr_exit(inode, error);
768 	return error;
769 }
770 EXPORT_SYMBOL_GPL(nfs_setattr);
771 
772 /**
773  * nfs_vmtruncate - unmap mappings "freed" by truncate() syscall
774  * @inode: inode of the file used
775  * @offset: file offset to start truncating
776  *
777  * This is a copy of the common vmtruncate, but with the locking
778  * corrected to take into account the fact that NFS requires
779  * inode->i_size to be updated under the inode->i_lock.
780  * Note: must be called with inode->i_lock held!
781  */
782 static int nfs_vmtruncate(struct inode * inode, loff_t offset)
783 {
784 	int err;
785 
786 	err = inode_newsize_ok(inode, offset);
787 	if (err)
788 		goto out;
789 
790 	trace_nfs_size_truncate(inode, offset);
791 	i_size_write(inode, offset);
792 	/* Optimisation */
793 	if (offset == 0) {
794 		NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_DATA;
795 		nfs_ooo_clear(NFS_I(inode));
796 	}
797 	NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_SIZE;
798 
799 	spin_unlock(&inode->i_lock);
800 	truncate_pagecache(inode, offset);
801 	nfs_update_delegated_mtime_locked(inode);
802 	spin_lock(&inode->i_lock);
803 out:
804 	return err;
805 }
806 
807 /**
808  * nfs_setattr_update_inode - Update inode metadata after a setattr call.
809  * @inode: pointer to struct inode
810  * @attr: pointer to struct iattr
811  * @fattr: pointer to struct nfs_fattr
812  *
813  * Note: we do this in the *proc.c in order to ensure that
814  *       it works for things like exclusive creates too.
815  */
816 void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr,
817 		struct nfs_fattr *fattr)
818 {
819 	/* Barrier: bump the attribute generation count. */
820 	nfs_fattr_set_barrier(fattr);
821 
822 	spin_lock(&inode->i_lock);
823 	NFS_I(inode)->attr_gencount = fattr->gencount;
824 	if ((attr->ia_valid & ATTR_SIZE) != 0) {
825 		if (!nfs_have_delegated_mtime(inode))
826 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_MTIME);
827 		nfs_set_cache_invalid(inode, NFS_INO_INVALID_BLOCKS);
828 		nfs_inc_stats(inode, NFSIOS_SETATTRTRUNC);
829 		nfs_vmtruncate(inode, attr->ia_size);
830 	}
831 	if ((attr->ia_valid & (ATTR_MODE|ATTR_UID|ATTR_GID)) != 0) {
832 		NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_CTIME;
833 		if ((attr->ia_valid & ATTR_KILL_SUID) != 0 &&
834 		    inode->i_mode & S_ISUID)
835 			inode->i_mode &= ~S_ISUID;
836 		if (setattr_should_drop_sgid(&nop_mnt_idmap, inode))
837 			inode->i_mode &= ~S_ISGID;
838 		if ((attr->ia_valid & ATTR_MODE) != 0) {
839 			int mode = attr->ia_mode & S_IALLUGO;
840 			mode |= inode->i_mode & ~S_IALLUGO;
841 			inode->i_mode = mode;
842 		}
843 		if ((attr->ia_valid & ATTR_UID) != 0)
844 			inode->i_uid = attr->ia_uid;
845 		if ((attr->ia_valid & ATTR_GID) != 0)
846 			inode->i_gid = attr->ia_gid;
847 		if (fattr->valid & NFS_ATTR_FATTR_CTIME)
848 			inode_set_ctime_to_ts(inode, fattr->ctime);
849 		else
850 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_CHANGE
851 					| NFS_INO_INVALID_CTIME);
852 		nfs_set_cache_invalid(inode, NFS_INO_INVALID_ACCESS
853 				| NFS_INO_INVALID_ACL);
854 	}
855 	if (attr->ia_valid & (ATTR_ATIME_SET|ATTR_ATIME)) {
856 		NFS_I(inode)->cache_validity &= ~(NFS_INO_INVALID_ATIME
857 				| NFS_INO_INVALID_CTIME);
858 		if (fattr->valid & NFS_ATTR_FATTR_ATIME)
859 			inode_set_atime_to_ts(inode, fattr->atime);
860 		else if (attr->ia_valid & ATTR_ATIME_SET)
861 			inode_set_atime_to_ts(inode, attr->ia_atime);
862 		else
863 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATIME);
864 
865 		if (fattr->valid & NFS_ATTR_FATTR_CTIME)
866 			inode_set_ctime_to_ts(inode, fattr->ctime);
867 		else
868 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_CHANGE
869 					| NFS_INO_INVALID_CTIME);
870 	}
871 	if (attr->ia_valid & (ATTR_MTIME_SET|ATTR_MTIME)) {
872 		NFS_I(inode)->cache_validity &= ~(NFS_INO_INVALID_MTIME
873 				| NFS_INO_INVALID_CTIME);
874 		if (fattr->valid & NFS_ATTR_FATTR_MTIME)
875 			inode_set_mtime_to_ts(inode, fattr->mtime);
876 		else if (attr->ia_valid & ATTR_MTIME_SET)
877 			inode_set_mtime_to_ts(inode, attr->ia_mtime);
878 		else
879 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_MTIME);
880 
881 		if (fattr->valid & NFS_ATTR_FATTR_CTIME)
882 			inode_set_ctime_to_ts(inode, fattr->ctime);
883 		else
884 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_CHANGE
885 					| NFS_INO_INVALID_CTIME);
886 	}
887 	if (fattr->valid)
888 		nfs_update_inode(inode, fattr);
889 	spin_unlock(&inode->i_lock);
890 }
891 EXPORT_SYMBOL_GPL(nfs_setattr_update_inode);
892 
893 /*
894  * Don't request help from readdirplus if the file is being written to,
895  * or if attribute caching is turned off
896  */
897 static bool nfs_getattr_readdirplus_enable(const struct inode *inode)
898 {
899 	return nfs_server_capable(inode, NFS_CAP_READDIRPLUS) &&
900 	       !nfs_have_writebacks(inode) && NFS_MAXATTRTIMEO(inode) > 5 * HZ;
901 }
902 
903 static void nfs_readdirplus_parent_cache_miss(struct dentry *dentry)
904 {
905 	if (!IS_ROOT(dentry)) {
906 		struct dentry *parent = dget_parent(dentry);
907 		nfs_readdir_record_entry_cache_miss(d_inode(parent));
908 		dput(parent);
909 	}
910 }
911 
912 static void nfs_readdirplus_parent_cache_hit(struct dentry *dentry)
913 {
914 	if (!IS_ROOT(dentry)) {
915 		struct dentry *parent = dget_parent(dentry);
916 		nfs_readdir_record_entry_cache_hit(d_inode(parent));
917 		dput(parent);
918 	}
919 }
920 
921 static u32 nfs_get_valid_attrmask(struct inode *inode)
922 {
923 	u64 fattr_valid = NFS_SERVER(inode)->fattr_valid;
924 	unsigned long cache_validity = READ_ONCE(NFS_I(inode)->cache_validity);
925 	u32 reply_mask = STATX_INO | STATX_TYPE;
926 
927 	if (!(cache_validity & NFS_INO_INVALID_ATIME))
928 		reply_mask |= STATX_ATIME;
929 	if (!(cache_validity & NFS_INO_INVALID_CTIME))
930 		reply_mask |= STATX_CTIME;
931 	if (!(cache_validity & NFS_INO_INVALID_MTIME))
932 		reply_mask |= STATX_MTIME;
933 	if (!(cache_validity & NFS_INO_INVALID_SIZE))
934 		reply_mask |= STATX_SIZE;
935 	if (!(cache_validity & NFS_INO_INVALID_NLINK))
936 		reply_mask |= STATX_NLINK;
937 	if (!(cache_validity & NFS_INO_INVALID_MODE))
938 		reply_mask |= STATX_MODE;
939 	if (!(cache_validity & NFS_INO_INVALID_OTHER))
940 		reply_mask |= STATX_UID | STATX_GID;
941 	if (!(cache_validity & NFS_INO_INVALID_BLOCKS))
942 		reply_mask |= STATX_BLOCKS;
943 	if (!(cache_validity & NFS_INO_INVALID_BTIME) &&
944 	    (fattr_valid & NFS_ATTR_FATTR_BTIME))
945 		reply_mask |= STATX_BTIME;
946 	if (!(cache_validity & NFS_INO_INVALID_CHANGE))
947 		reply_mask |= STATX_CHANGE_COOKIE;
948 	return reply_mask;
949 }
950 
951 int nfs_getattr(struct mnt_idmap *idmap, const struct path *path,
952 		struct kstat *stat, u32 request_mask, unsigned int query_flags)
953 {
954 	struct inode *inode = d_inode(path->dentry);
955 	struct nfs_server *server = NFS_SERVER(inode);
956 	u64 fattr_valid = server->fattr_valid;
957 	unsigned long cache_validity;
958 	int err = 0;
959 	bool force_sync = query_flags & AT_STATX_FORCE_SYNC;
960 	bool do_update = false;
961 	bool readdirplus_enabled = nfs_getattr_readdirplus_enable(inode);
962 
963 	trace_nfs_getattr_enter(inode);
964 
965 	request_mask &= STATX_TYPE | STATX_MODE | STATX_NLINK | STATX_UID |
966 			STATX_GID | STATX_ATIME | STATX_MTIME | STATX_CTIME |
967 			STATX_INO | STATX_SIZE | STATX_BLOCKS | STATX_BTIME |
968 			STATX_CHANGE_COOKIE;
969 
970 	if (!(fattr_valid & NFS_ATTR_FATTR_BTIME))
971 		request_mask &= ~STATX_BTIME;
972 
973 	if ((query_flags & AT_STATX_DONT_SYNC) && !force_sync) {
974 		if (readdirplus_enabled)
975 			nfs_readdirplus_parent_cache_hit(path->dentry);
976 		goto out_no_revalidate;
977 	}
978 
979 	/* Flush out writes to the server in order to update c/mtime/version.  */
980 	if ((request_mask & (STATX_CTIME | STATX_MTIME | STATX_CHANGE_COOKIE)) &&
981 	    S_ISREG(inode->i_mode)) {
982 		if (nfs_have_delegated_mtime(inode))
983 			filemap_fdatawrite(inode->i_mapping);
984 		else
985 			filemap_write_and_wait(inode->i_mapping);
986 	}
987 
988 	/*
989 	 * We may force a getattr if the user cares about atime.
990 	 *
991 	 * Note that we only have to check the vfsmount flags here:
992 	 *  - NFS always sets S_NOATIME by so checking it would give a
993 	 *    bogus result
994 	 *  - NFS never sets SB_NOATIME or SB_NODIRATIME so there is
995 	 *    no point in checking those.
996 	 */
997 	if ((path->mnt->mnt_flags & MNT_NOATIME) ||
998 	    ((path->mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode)))
999 		request_mask &= ~STATX_ATIME;
1000 
1001 	/* Is the user requesting attributes that might need revalidation? */
1002 	if (!(request_mask & (STATX_MODE|STATX_NLINK|STATX_ATIME|STATX_CTIME|
1003 					STATX_MTIME|STATX_UID|STATX_GID|
1004 					STATX_SIZE|STATX_BLOCKS|STATX_BTIME|
1005 					STATX_CHANGE_COOKIE)))
1006 		goto out_no_revalidate;
1007 
1008 	/* Check whether the cached attributes are stale */
1009 	do_update |= force_sync || nfs_attribute_cache_expired(inode);
1010 	cache_validity = READ_ONCE(NFS_I(inode)->cache_validity);
1011 	do_update |= cache_validity & NFS_INO_INVALID_CHANGE;
1012 	if (request_mask & STATX_ATIME)
1013 		do_update |= cache_validity & NFS_INO_INVALID_ATIME;
1014 	if (request_mask & STATX_CTIME)
1015 		do_update |= cache_validity & NFS_INO_INVALID_CTIME;
1016 	if (request_mask & STATX_MTIME)
1017 		do_update |= cache_validity & NFS_INO_INVALID_MTIME;
1018 	if (request_mask & STATX_SIZE)
1019 		do_update |= cache_validity & NFS_INO_INVALID_SIZE;
1020 	if (request_mask & STATX_NLINK)
1021 		do_update |= cache_validity & NFS_INO_INVALID_NLINK;
1022 	if (request_mask & STATX_MODE)
1023 		do_update |= cache_validity & NFS_INO_INVALID_MODE;
1024 	if (request_mask & (STATX_UID | STATX_GID))
1025 		do_update |= cache_validity & NFS_INO_INVALID_OTHER;
1026 	if (request_mask & STATX_BLOCKS)
1027 		do_update |= cache_validity & NFS_INO_INVALID_BLOCKS;
1028 	if (request_mask & STATX_BTIME)
1029 		do_update |= cache_validity & NFS_INO_INVALID_BTIME;
1030 
1031 	if (do_update) {
1032 		if (readdirplus_enabled)
1033 			nfs_readdirplus_parent_cache_miss(path->dentry);
1034 		err = __nfs_revalidate_inode(server, inode);
1035 		if (err)
1036 			goto out;
1037 	} else if (readdirplus_enabled)
1038 		nfs_readdirplus_parent_cache_hit(path->dentry);
1039 out_no_revalidate:
1040 	/* Only return attributes that were revalidated. */
1041 	stat->result_mask = nfs_get_valid_attrmask(inode) | request_mask;
1042 
1043 	generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat);
1044 	stat->change_cookie = inode_peek_iversion_raw(inode);
1045 	stat->attributes_mask |= STATX_ATTR_CHANGE_MONOTONIC;
1046 	if (server->change_attr_type != NFS4_CHANGE_TYPE_IS_UNDEFINED)
1047 		stat->attributes |= STATX_ATTR_CHANGE_MONOTONIC;
1048 	if (S_ISDIR(inode->i_mode))
1049 		stat->blksize = NFS_SERVER(inode)->dtsize;
1050 	stat->btime = NFS_I(inode)->btime;
1051 
1052 	/* Special handling for STATX_DIOALIGN and STATX_DIO_READ_ALIGN
1053 	 * - NFS doesn't have DIO alignment constraints, avoid getting
1054 	 *   these DIO attrs from remote and just respond with most
1055 	 *   accommodating limits (so client will issue supported DIO).
1056 	 * - this is unintuitive, but the most coarse-grained
1057 	 *   dio_offset_align is the most accommodating.
1058 	 */
1059 	if ((request_mask & (STATX_DIOALIGN | STATX_DIO_READ_ALIGN)) &&
1060 	    S_ISREG(inode->i_mode)) {
1061 		stat->result_mask |= STATX_DIOALIGN | STATX_DIO_READ_ALIGN;
1062 		stat->dio_mem_align = 4; /* 4-byte alignment */
1063 		stat->dio_offset_align = PAGE_SIZE;
1064 		stat->dio_read_offset_align = stat->dio_offset_align;
1065 	}
1066 out:
1067 	trace_nfs_getattr_exit(inode, err);
1068 	return err;
1069 }
1070 EXPORT_SYMBOL_GPL(nfs_getattr);
1071 
1072 int nfs_fileattr_get(struct dentry *dentry, struct file_kattr *fa)
1073 {
1074 	struct inode *inode = d_inode(dentry);
1075 
1076 	if (nfs_server_capable(inode, NFS_CAP_CASE_INSENSITIVE)) {
1077 		fa->fsx_xflags |= FS_XFLAG_CASEFOLD;
1078 		fa->flags |= FS_CASEFOLD_FL;
1079 	}
1080 	if (nfs_server_capable(inode, NFS_CAP_CASE_NONPRESERVING))
1081 		fa->fsx_xflags |= FS_XFLAG_CASENONPRESERVING;
1082 	return 0;
1083 }
1084 EXPORT_SYMBOL_GPL(nfs_fileattr_get);
1085 
1086 static void nfs_init_lock_context(struct nfs_lock_context *l_ctx)
1087 {
1088 	refcount_set(&l_ctx->count, 1);
1089 	l_ctx->lockowner = current->files;
1090 	INIT_LIST_HEAD(&l_ctx->list);
1091 	atomic_set(&l_ctx->io_count, 0);
1092 }
1093 
1094 static struct nfs_lock_context *__nfs_find_lock_context(struct nfs_open_context *ctx)
1095 {
1096 	struct nfs_lock_context *pos;
1097 
1098 	list_for_each_entry_rcu(pos, &ctx->lock_context.list, list) {
1099 		if (pos->lockowner != current->files)
1100 			continue;
1101 		if (refcount_inc_not_zero(&pos->count))
1102 			return pos;
1103 	}
1104 	return NULL;
1105 }
1106 
1107 struct nfs_lock_context *nfs_get_lock_context(struct nfs_open_context *ctx)
1108 {
1109 	struct nfs_lock_context *res, *new = NULL;
1110 	struct inode *inode = d_inode(ctx->dentry);
1111 
1112 	rcu_read_lock();
1113 	res = __nfs_find_lock_context(ctx);
1114 	rcu_read_unlock();
1115 	if (res == NULL) {
1116 		new = kmalloc_obj(*new, GFP_KERNEL_ACCOUNT);
1117 		if (new == NULL)
1118 			return ERR_PTR(-ENOMEM);
1119 		nfs_init_lock_context(new);
1120 		spin_lock(&inode->i_lock);
1121 		res = __nfs_find_lock_context(ctx);
1122 		if (res == NULL) {
1123 			new->open_context = get_nfs_open_context(ctx);
1124 			if (new->open_context) {
1125 				list_add_tail_rcu(&new->list,
1126 						&ctx->lock_context.list);
1127 				res = new;
1128 				new = NULL;
1129 			} else
1130 				res = ERR_PTR(-EBADF);
1131 		}
1132 		spin_unlock(&inode->i_lock);
1133 		kfree(new);
1134 	}
1135 	return res;
1136 }
1137 EXPORT_SYMBOL_GPL(nfs_get_lock_context);
1138 
1139 void nfs_put_lock_context(struct nfs_lock_context *l_ctx)
1140 {
1141 	struct nfs_open_context *ctx = l_ctx->open_context;
1142 	struct inode *inode = d_inode(ctx->dentry);
1143 
1144 	if (!refcount_dec_and_lock(&l_ctx->count, &inode->i_lock))
1145 		return;
1146 	list_del_rcu(&l_ctx->list);
1147 	spin_unlock(&inode->i_lock);
1148 	put_nfs_open_context(ctx);
1149 	kfree_rcu(l_ctx, rcu_head);
1150 }
1151 EXPORT_SYMBOL_GPL(nfs_put_lock_context);
1152 
1153 /**
1154  * nfs_close_context - Common close_context() routine NFSv2/v3
1155  * @ctx: pointer to context
1156  * @is_sync: is this a synchronous close
1157  *
1158  * Ensure that the attributes are up to date if we're mounted
1159  * with close-to-open semantics and we have cached data that will
1160  * need to be revalidated on open.
1161  */
1162 void nfs_close_context(struct nfs_open_context *ctx, int is_sync)
1163 {
1164 	struct nfs_inode *nfsi;
1165 	struct inode *inode;
1166 
1167 	if (!(ctx->mode & FMODE_WRITE))
1168 		return;
1169 	if (!is_sync)
1170 		return;
1171 	inode = d_inode(ctx->dentry);
1172 	if (nfs_have_read_or_write_delegation(inode))
1173 		return;
1174 	nfsi = NFS_I(inode);
1175 	if (inode->i_mapping->nrpages == 0)
1176 		return;
1177 	if (nfsi->cache_validity & NFS_INO_INVALID_DATA)
1178 		return;
1179 	if (!list_empty(&nfsi->open_files))
1180 		return;
1181 	if (NFS_SERVER(inode)->flags & NFS_MOUNT_NOCTO)
1182 		return;
1183 	nfs_revalidate_inode(inode,
1184 			     NFS_INO_INVALID_CHANGE | NFS_INO_INVALID_SIZE);
1185 }
1186 EXPORT_SYMBOL_GPL(nfs_close_context);
1187 
1188 struct nfs_open_context *alloc_nfs_open_context(struct dentry *dentry,
1189 						fmode_t f_mode,
1190 						struct file *filp)
1191 {
1192 	struct nfs_open_context *ctx;
1193 
1194 	ctx = kmalloc_obj(*ctx, GFP_KERNEL_ACCOUNT);
1195 	if (!ctx)
1196 		return ERR_PTR(-ENOMEM);
1197 	nfs_sb_active(dentry->d_sb);
1198 	ctx->dentry = dget(dentry);
1199 	if (filp)
1200 		ctx->cred = get_cred(filp->f_cred);
1201 	else
1202 		ctx->cred = get_current_cred();
1203 	rcu_assign_pointer(ctx->ll_cred, NULL);
1204 	ctx->state = NULL;
1205 	ctx->mode = f_mode;
1206 	ctx->flags = 0;
1207 	ctx->error = 0;
1208 	ctx->flock_owner = (fl_owner_t)filp;
1209 	nfs_init_lock_context(&ctx->lock_context);
1210 	ctx->lock_context.open_context = ctx;
1211 	INIT_LIST_HEAD(&ctx->list);
1212 	ctx->mdsthreshold = NULL;
1213 	nfs_localio_file_init(&ctx->nfl);
1214 
1215 	return ctx;
1216 }
1217 EXPORT_SYMBOL_GPL(alloc_nfs_open_context);
1218 
1219 struct nfs_open_context *get_nfs_open_context(struct nfs_open_context *ctx)
1220 {
1221 	if (ctx != NULL && refcount_inc_not_zero(&ctx->lock_context.count))
1222 		return ctx;
1223 	return NULL;
1224 }
1225 EXPORT_SYMBOL_GPL(get_nfs_open_context);
1226 
1227 static void __put_nfs_open_context(struct nfs_open_context *ctx, int is_sync)
1228 {
1229 	struct inode *inode = d_inode(ctx->dentry);
1230 	struct super_block *sb = ctx->dentry->d_sb;
1231 
1232 	if (!refcount_dec_and_test(&ctx->lock_context.count))
1233 		return;
1234 	if (!list_empty(&ctx->list)) {
1235 		spin_lock(&inode->i_lock);
1236 		list_del_rcu(&ctx->list);
1237 		spin_unlock(&inode->i_lock);
1238 	}
1239 	if (inode != NULL)
1240 		NFS_PROTO(inode)->close_context(ctx, is_sync);
1241 	put_cred(ctx->cred);
1242 	dput(ctx->dentry);
1243 	nfs_sb_deactive(sb);
1244 	put_rpccred(rcu_dereference_protected(ctx->ll_cred, 1));
1245 	kfree(ctx->mdsthreshold);
1246 	nfs_close_local_fh(&ctx->nfl);
1247 	kfree_rcu(ctx, rcu_head);
1248 }
1249 
1250 void put_nfs_open_context(struct nfs_open_context *ctx)
1251 {
1252 	__put_nfs_open_context(ctx, 0);
1253 }
1254 EXPORT_SYMBOL_GPL(put_nfs_open_context);
1255 
1256 static void put_nfs_open_context_sync(struct nfs_open_context *ctx)
1257 {
1258 	__put_nfs_open_context(ctx, 1);
1259 }
1260 
1261 /*
1262  * Ensure that mmap has a recent RPC credential for use when writing out
1263  * shared pages
1264  */
1265 void nfs_inode_attach_open_context(struct nfs_open_context *ctx)
1266 {
1267 	struct inode *inode = d_inode(ctx->dentry);
1268 	struct nfs_inode *nfsi = NFS_I(inode);
1269 
1270 	spin_lock(&inode->i_lock);
1271 	if (list_empty(&nfsi->open_files) &&
1272 	    nfs_ooo_test(nfsi))
1273 		nfs_set_cache_invalid(inode, NFS_INO_INVALID_DATA |
1274 						     NFS_INO_REVAL_FORCED);
1275 	list_add_tail_rcu(&ctx->list, &nfsi->open_files);
1276 	spin_unlock(&inode->i_lock);
1277 }
1278 EXPORT_SYMBOL_GPL(nfs_inode_attach_open_context);
1279 
1280 void nfs_file_set_open_context(struct file *filp, struct nfs_open_context *ctx)
1281 {
1282 	filp->private_data = get_nfs_open_context(ctx);
1283 	set_bit(NFS_CONTEXT_FILE_OPEN, &ctx->flags);
1284 	if (list_empty(&ctx->list))
1285 		nfs_inode_attach_open_context(ctx);
1286 }
1287 EXPORT_SYMBOL_GPL(nfs_file_set_open_context);
1288 
1289 /*
1290  * Given an inode, search for an open context with the desired characteristics
1291  */
1292 struct nfs_open_context *nfs_find_open_context(struct inode *inode, const struct cred *cred, fmode_t mode)
1293 {
1294 	struct nfs_inode *nfsi = NFS_I(inode);
1295 	struct nfs_open_context *pos, *ctx = NULL;
1296 
1297 	rcu_read_lock();
1298 	list_for_each_entry_rcu(pos, &nfsi->open_files, list) {
1299 		if (cred != NULL && cred_fscmp(pos->cred, cred) != 0)
1300 			continue;
1301 		if ((pos->mode & (FMODE_READ|FMODE_WRITE)) != mode)
1302 			continue;
1303 		if (!test_bit(NFS_CONTEXT_FILE_OPEN, &pos->flags))
1304 			continue;
1305 		ctx = get_nfs_open_context(pos);
1306 		if (ctx)
1307 			break;
1308 	}
1309 	rcu_read_unlock();
1310 	return ctx;
1311 }
1312 
1313 void nfs_file_clear_open_context(struct file *filp)
1314 {
1315 	struct nfs_open_context *ctx = nfs_file_open_context(filp);
1316 
1317 	if (ctx) {
1318 		struct inode *inode = d_inode(ctx->dentry);
1319 
1320 		clear_bit(NFS_CONTEXT_FILE_OPEN, &ctx->flags);
1321 		/*
1322 		 * We fatal error on write before. Try to writeback
1323 		 * every page again.
1324 		 */
1325 		if (ctx->error < 0)
1326 			invalidate_inode_pages2(inode->i_mapping);
1327 		filp->private_data = NULL;
1328 		put_nfs_open_context_sync(ctx);
1329 	}
1330 }
1331 
1332 /*
1333  * These allocate and release file read/write context information.
1334  */
1335 int nfs_open(struct inode *inode, struct file *filp)
1336 {
1337 	struct nfs_open_context *ctx;
1338 
1339 	ctx = alloc_nfs_open_context(file_dentry(filp),
1340 				     flags_to_mode(filp->f_flags), filp);
1341 	if (IS_ERR(ctx))
1342 		return PTR_ERR(ctx);
1343 	nfs_file_set_open_context(filp, ctx);
1344 	put_nfs_open_context(ctx);
1345 	nfs_fscache_open_file(inode, filp);
1346 	return 0;
1347 }
1348 
1349 /*
1350  * This function is called whenever some part of NFS notices that
1351  * the cached attributes have to be refreshed.
1352  */
1353 int
1354 __nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
1355 {
1356 	int		 status = -ESTALE;
1357 	struct nfs_fattr *fattr = NULL;
1358 	struct nfs_inode *nfsi = NFS_I(inode);
1359 
1360 	dfprintk(PAGECACHE, "NFS: revalidating (%s/%Lu)\n",
1361 		inode->i_sb->s_id, (unsigned long long)inode->i_ino);
1362 
1363 	trace_nfs_revalidate_inode_enter(inode);
1364 
1365 	if (is_bad_inode(inode))
1366 		goto out;
1367 	if (NFS_STALE(inode))
1368 		goto out;
1369 
1370 	/* pNFS: Attributes aren't updated until we layoutcommit */
1371 	if (S_ISREG(inode->i_mode)) {
1372 		status = pnfs_sync_inode(inode, false);
1373 		if (status)
1374 			goto out;
1375 	} else if (nfs_have_directory_delegation(inode) &&
1376 		   !(NFS_I(inode)->cache_validity & NFS_INO_INVALID_ATTR)) {
1377 		status = 0;
1378 		goto out;
1379 	}
1380 
1381 	status = -ENOMEM;
1382 	fattr = nfs_alloc_fattr_with_label(NFS_SERVER(inode));
1383 	if (fattr == NULL)
1384 		goto out;
1385 
1386 	nfs_inc_stats(inode, NFSIOS_INODEREVALIDATE);
1387 
1388 	status = NFS_PROTO(inode)->getattr(server, NFS_FH(inode), fattr, inode);
1389 	if (status != 0) {
1390 		dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Lu) getattr failed, error=%d\n",
1391 			 inode->i_sb->s_id,
1392 			 (unsigned long long)inode->i_ino, status);
1393 		switch (status) {
1394 		case -ETIMEDOUT:
1395 			/* A soft timeout occurred. Use cached information? */
1396 			if (server->flags & NFS_MOUNT_SOFTREVAL)
1397 				status = 0;
1398 			break;
1399 		case -ESTALE:
1400 			if (!S_ISDIR(inode->i_mode))
1401 				nfs_set_inode_stale(inode);
1402 			else
1403 				nfs_zap_caches(inode);
1404 		}
1405 		goto out;
1406 	}
1407 
1408 	status = nfs_refresh_inode(inode, fattr);
1409 	if (status) {
1410 		dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Lu) refresh failed, error=%d\n",
1411 			 inode->i_sb->s_id,
1412 			 (unsigned long long)inode->i_ino, status);
1413 		goto out;
1414 	}
1415 
1416 	if (nfsi->cache_validity & NFS_INO_INVALID_ACL)
1417 		nfs_zap_acl_cache(inode);
1418 
1419 	nfs_setsecurity(inode, fattr);
1420 
1421 	dfprintk(PAGECACHE, "NFS: (%s/%Lu) revalidation complete\n",
1422 		inode->i_sb->s_id,
1423 		(unsigned long long)inode->i_ino);
1424 
1425 out:
1426 	nfs_free_fattr(fattr);
1427 	trace_nfs_revalidate_inode_exit(inode, status);
1428 	return status;
1429 }
1430 
1431 int nfs_attribute_cache_expired(struct inode *inode)
1432 {
1433 	if (nfs_have_delegated_attributes(inode))
1434 		return 0;
1435 	return nfs_attribute_timeout(inode);
1436 }
1437 
1438 /**
1439  * nfs_revalidate_inode - Revalidate the inode attributes
1440  * @inode: pointer to inode struct
1441  * @flags: cache flags to check
1442  *
1443  * Updates inode attribute information by retrieving the data from the server.
1444  */
1445 int nfs_revalidate_inode(struct inode *inode, unsigned long flags)
1446 {
1447 	if (!nfs_check_cache_invalid(inode, flags))
1448 		return NFS_STALE(inode) ? -ESTALE : 0;
1449 	return __nfs_revalidate_inode(NFS_SERVER(inode), inode);
1450 }
1451 EXPORT_SYMBOL_GPL(nfs_revalidate_inode);
1452 
1453 static int nfs_invalidate_mapping(struct inode *inode, struct address_space *mapping)
1454 {
1455 	int ret;
1456 
1457 	nfs_fscache_invalidate(inode, 0);
1458 	if (mapping->nrpages != 0) {
1459 		if (S_ISREG(inode->i_mode)) {
1460 			ret = nfs_sync_mapping(mapping);
1461 			if (ret < 0)
1462 				return ret;
1463 		}
1464 		ret = invalidate_inode_pages2(mapping);
1465 		if (ret < 0)
1466 			return ret;
1467 	}
1468 	nfs_inc_stats(inode, NFSIOS_DATAINVALIDATE);
1469 
1470 	dfprintk(PAGECACHE, "NFS: (%s/%Lu) data cache invalidated\n",
1471 			inode->i_sb->s_id,
1472 			(unsigned long long)inode->i_ino);
1473 	return 0;
1474 }
1475 
1476 /**
1477  * nfs_clear_invalid_mapping - Conditionally clear a mapping
1478  * @mapping: pointer to mapping
1479  *
1480  * If the NFS_INO_INVALID_DATA inode flag is set, clear the mapping.
1481  */
1482 int nfs_clear_invalid_mapping(struct address_space *mapping)
1483 {
1484 	struct inode *inode = mapping->host;
1485 	struct nfs_inode *nfsi = NFS_I(inode);
1486 	unsigned long *bitlock = &nfsi->flags;
1487 	int ret = 0;
1488 
1489 	/*
1490 	 * We must clear NFS_INO_INVALID_DATA first to ensure that
1491 	 * invalidations that come in while we're shooting down the mappings
1492 	 * are respected. But, that leaves a race window where one revalidator
1493 	 * can clear the flag, and then another checks it before the mapping
1494 	 * gets invalidated. Fix that by serializing access to this part of
1495 	 * the function.
1496 	 *
1497 	 * At the same time, we need to allow other tasks to see whether we
1498 	 * might be in the middle of invalidating the pages, so we only set
1499 	 * the bit lock here if it looks like we're going to be doing that.
1500 	 */
1501 	for (;;) {
1502 		ret = wait_on_bit_action(bitlock, NFS_INO_INVALIDATING,
1503 					 nfs_wait_bit_killable,
1504 					 TASK_KILLABLE|TASK_FREEZABLE_UNSAFE);
1505 		if (ret)
1506 			goto out;
1507 		smp_rmb(); /* pairs with smp_wmb() below */
1508 		if (test_bit(NFS_INO_INVALIDATING, bitlock))
1509 			continue;
1510 		/* pairs with nfs_set_cache_invalid()'s smp_store_release() */
1511 		if (!(smp_load_acquire(&nfsi->cache_validity) & NFS_INO_INVALID_DATA))
1512 			goto out;
1513 		/* Slow-path that double-checks with spinlock held */
1514 		spin_lock(&inode->i_lock);
1515 		if (test_bit(NFS_INO_INVALIDATING, bitlock)) {
1516 			spin_unlock(&inode->i_lock);
1517 			continue;
1518 		}
1519 		if (nfsi->cache_validity & NFS_INO_INVALID_DATA)
1520 			break;
1521 		spin_unlock(&inode->i_lock);
1522 		goto out;
1523 	}
1524 
1525 	set_bit(NFS_INO_INVALIDATING, bitlock);
1526 	smp_wmb();
1527 	nfsi->cache_validity &= ~NFS_INO_INVALID_DATA;
1528 	nfs_ooo_clear(nfsi);
1529 	spin_unlock(&inode->i_lock);
1530 	trace_nfs_invalidate_mapping_enter(inode);
1531 	ret = nfs_invalidate_mapping(inode, mapping);
1532 	trace_nfs_invalidate_mapping_exit(inode, ret);
1533 
1534 	clear_bit_unlock(NFS_INO_INVALIDATING, bitlock);
1535 	smp_mb__after_atomic();
1536 	wake_up_bit(bitlock, NFS_INO_INVALIDATING);
1537 out:
1538 	return ret;
1539 }
1540 
1541 bool nfs_mapping_need_revalidate_inode(struct inode *inode)
1542 {
1543 	return nfs_check_cache_invalid(inode, NFS_INO_INVALID_CHANGE) ||
1544 		NFS_STALE(inode);
1545 }
1546 
1547 int nfs_revalidate_mapping_rcu(struct inode *inode)
1548 {
1549 	struct nfs_inode *nfsi = NFS_I(inode);
1550 	unsigned long *bitlock = &nfsi->flags;
1551 	int ret = 0;
1552 
1553 	if (IS_SWAPFILE(inode))
1554 		goto out;
1555 	if (nfs_mapping_need_revalidate_inode(inode)) {
1556 		ret = -ECHILD;
1557 		goto out;
1558 	}
1559 	spin_lock(&inode->i_lock);
1560 	if (test_bit(NFS_INO_INVALIDATING, bitlock) ||
1561 	    (nfsi->cache_validity & NFS_INO_INVALID_DATA))
1562 		ret = -ECHILD;
1563 	spin_unlock(&inode->i_lock);
1564 out:
1565 	return ret;
1566 }
1567 
1568 /**
1569  * nfs_revalidate_mapping - Revalidate the pagecache
1570  * @inode: pointer to host inode
1571  * @mapping: pointer to mapping
1572  */
1573 int nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping)
1574 {
1575 	/* swapfiles are not supposed to be shared. */
1576 	if (IS_SWAPFILE(inode))
1577 		return 0;
1578 
1579 	if (nfs_mapping_need_revalidate_inode(inode)) {
1580 		int ret = __nfs_revalidate_inode(NFS_SERVER(inode), inode);
1581 		if (ret < 0)
1582 			return ret;
1583 	}
1584 
1585 	return nfs_clear_invalid_mapping(mapping);
1586 }
1587 
1588 static bool nfs_file_has_writers(struct nfs_inode *nfsi)
1589 {
1590 	struct inode *inode = &nfsi->vfs_inode;
1591 
1592 	if (!S_ISREG(inode->i_mode))
1593 		return false;
1594 	if (list_empty(&nfsi->open_files))
1595 		return false;
1596 	return inode_is_open_for_write(inode);
1597 }
1598 
1599 static bool nfs_file_has_buffered_writers(struct nfs_inode *nfsi)
1600 {
1601 	return nfs_file_has_writers(nfsi) && nfs_file_io_is_buffered(nfsi);
1602 }
1603 
1604 static void nfs_wcc_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1605 {
1606 	struct timespec64 ts;
1607 
1608 	if ((fattr->valid & NFS_ATTR_FATTR_PRECHANGE)
1609 			&& (fattr->valid & NFS_ATTR_FATTR_CHANGE)
1610 			&& inode_eq_iversion_raw(inode, fattr->pre_change_attr)) {
1611 		inode_set_iversion_raw(inode, fattr->change_attr);
1612 		if (S_ISDIR(inode->i_mode))
1613 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_DATA);
1614 		else if (nfs_server_capable(inode, NFS_CAP_XATTR))
1615 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_XATTR);
1616 	}
1617 	/* If we have atomic WCC data, we may update some attributes */
1618 	ts = inode_get_ctime(inode);
1619 	if ((fattr->valid & NFS_ATTR_FATTR_PRECTIME)
1620 			&& (fattr->valid & NFS_ATTR_FATTR_CTIME)
1621 			&& timespec64_equal(&ts, &fattr->pre_ctime)) {
1622 		inode_set_ctime_to_ts(inode, fattr->ctime);
1623 	}
1624 
1625 	ts = inode_get_mtime(inode);
1626 	if ((fattr->valid & NFS_ATTR_FATTR_PREMTIME)
1627 			&& (fattr->valid & NFS_ATTR_FATTR_MTIME)
1628 			&& timespec64_equal(&ts, &fattr->pre_mtime)) {
1629 		inode_set_mtime_to_ts(inode, fattr->mtime);
1630 	}
1631 	if ((fattr->valid & NFS_ATTR_FATTR_PRESIZE)
1632 			&& (fattr->valid & NFS_ATTR_FATTR_SIZE)
1633 			&& i_size_read(inode) == nfs_size_to_loff_t(fattr->pre_size)
1634 			&& !nfs_have_writebacks(inode)) {
1635 		trace_nfs_size_wcc(inode, fattr->size);
1636 		i_size_write(inode, nfs_size_to_loff_t(fattr->size));
1637 	}
1638 }
1639 
1640 /**
1641  * nfs_check_inode_attributes - verify consistency of the inode attribute cache
1642  * @inode: pointer to inode
1643  * @fattr: updated attributes
1644  *
1645  * Verifies the attribute cache. If we have just changed the attributes,
1646  * so that fattr carries weak cache consistency data, then it may
1647  * also update the ctime/mtime/change_attribute.
1648  */
1649 static int nfs_check_inode_attributes(struct inode *inode, struct nfs_fattr *fattr)
1650 {
1651 	struct nfs_inode *nfsi = NFS_I(inode);
1652 	loff_t cur_size, new_isize;
1653 	unsigned long invalid = 0;
1654 	struct timespec64 ts;
1655 
1656 	if (nfs_have_delegated_attributes(inode))
1657 		return 0;
1658 
1659 	if (!(fattr->valid & NFS_ATTR_FATTR_FILEID)) {
1660 		/* Only a mounted-on-fileid? Just exit */
1661 		if (fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID)
1662 			return 0;
1663 	/* Has the inode gone and changed behind our back? */
1664 	} else if (inode->i_ino != fattr->fileid) {
1665 		/* Is this perhaps the mounted-on fileid? */
1666 		if ((fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID) &&
1667 		    inode->i_ino == fattr->mounted_on_fileid)
1668 			return 0;
1669 		return -ESTALE;
1670 	}
1671 	if ((fattr->valid & NFS_ATTR_FATTR_TYPE) && inode_wrong_type(inode, fattr->mode))
1672 		return -ESTALE;
1673 
1674 
1675 	if (!nfs_file_has_buffered_writers(nfsi)) {
1676 		/* Verify a few of the more important attributes */
1677 		if ((fattr->valid & NFS_ATTR_FATTR_CHANGE) != 0 && !inode_eq_iversion_raw(inode, fattr->change_attr))
1678 			invalid |= NFS_INO_INVALID_CHANGE;
1679 
1680 		ts = inode_get_mtime(inode);
1681 		if ((fattr->valid & NFS_ATTR_FATTR_MTIME) && !timespec64_equal(&ts, &fattr->mtime))
1682 			invalid |= NFS_INO_INVALID_MTIME;
1683 
1684 		ts = inode_get_ctime(inode);
1685 		if ((fattr->valid & NFS_ATTR_FATTR_CTIME) && !timespec64_equal(&ts, &fattr->ctime))
1686 			invalid |= NFS_INO_INVALID_CTIME;
1687 
1688 		if (fattr->valid & NFS_ATTR_FATTR_SIZE) {
1689 			cur_size = i_size_read(inode);
1690 			new_isize = nfs_size_to_loff_t(fattr->size);
1691 			if (cur_size != new_isize)
1692 				invalid |= NFS_INO_INVALID_SIZE;
1693 		}
1694 	}
1695 
1696 	/* Have any file permissions changed? */
1697 	if ((fattr->valid & NFS_ATTR_FATTR_MODE) && (inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO))
1698 		invalid |= NFS_INO_INVALID_MODE;
1699 	if ((fattr->valid & NFS_ATTR_FATTR_OWNER) && !uid_eq(inode->i_uid, fattr->uid))
1700 		invalid |= NFS_INO_INVALID_OTHER;
1701 	if ((fattr->valid & NFS_ATTR_FATTR_GROUP) && !gid_eq(inode->i_gid, fattr->gid))
1702 		invalid |= NFS_INO_INVALID_OTHER;
1703 
1704 	/* Has the link count changed? */
1705 	if ((fattr->valid & NFS_ATTR_FATTR_NLINK) && inode->i_nlink != fattr->nlink)
1706 		invalid |= NFS_INO_INVALID_NLINK;
1707 
1708 	ts = inode_get_atime(inode);
1709 	if ((fattr->valid & NFS_ATTR_FATTR_ATIME) && !timespec64_equal(&ts, &fattr->atime))
1710 		invalid |= NFS_INO_INVALID_ATIME;
1711 
1712 	if (invalid != 0)
1713 		nfs_set_cache_invalid(inode, invalid);
1714 
1715 	nfsi->read_cache_jiffies = fattr->time_start;
1716 	return 0;
1717 }
1718 
1719 static atomic_long_t nfs_attr_generation_counter;
1720 
1721 static unsigned long nfs_read_attr_generation_counter(void)
1722 {
1723 	return atomic_long_read(&nfs_attr_generation_counter);
1724 }
1725 
1726 unsigned long nfs_inc_attr_generation_counter(void)
1727 {
1728 	return atomic_long_inc_return(&nfs_attr_generation_counter);
1729 }
1730 EXPORT_SYMBOL_GPL(nfs_inc_attr_generation_counter);
1731 
1732 void nfs_fattr_init(struct nfs_fattr *fattr)
1733 {
1734 	fattr->valid = 0;
1735 	fattr->time_start = jiffies;
1736 	fattr->gencount = nfs_inc_attr_generation_counter();
1737 	fattr->owner_name = NULL;
1738 	fattr->group_name = NULL;
1739 	fattr->mdsthreshold = NULL;
1740 }
1741 EXPORT_SYMBOL_GPL(nfs_fattr_init);
1742 
1743 /**
1744  * nfs_fattr_set_barrier
1745  * @fattr: attributes
1746  *
1747  * Used to set a barrier after an attribute was updated. This
1748  * barrier ensures that older attributes from RPC calls that may
1749  * have raced with our update cannot clobber these new values.
1750  * Note that you are still responsible for ensuring that other
1751  * operations which change the attribute on the server do not
1752  * collide.
1753  */
1754 void nfs_fattr_set_barrier(struct nfs_fattr *fattr)
1755 {
1756 	fattr->gencount = nfs_inc_attr_generation_counter();
1757 }
1758 
1759 struct nfs_fattr *nfs_alloc_fattr(void)
1760 {
1761 	struct nfs_fattr *fattr;
1762 
1763 	fattr = kmalloc_obj(*fattr);
1764 	if (fattr != NULL) {
1765 		nfs_fattr_init(fattr);
1766 		fattr->label = NULL;
1767 	}
1768 	return fattr;
1769 }
1770 EXPORT_SYMBOL_GPL(nfs_alloc_fattr);
1771 
1772 struct nfs_fattr *nfs_alloc_fattr_with_label(struct nfs_server *server)
1773 {
1774 	struct nfs_fattr *fattr = nfs_alloc_fattr();
1775 
1776 	if (!fattr)
1777 		return NULL;
1778 
1779 	fattr->label = nfs4_label_alloc(server, GFP_KERNEL);
1780 	if (IS_ERR(fattr->label)) {
1781 		kfree(fattr);
1782 		return NULL;
1783 	}
1784 
1785 	return fattr;
1786 }
1787 EXPORT_SYMBOL_GPL(nfs_alloc_fattr_with_label);
1788 
1789 struct nfs_fh *nfs_alloc_fhandle(void)
1790 {
1791 	struct nfs_fh *fh;
1792 
1793 	fh = kmalloc_obj(struct nfs_fh);
1794 	if (fh != NULL)
1795 		fh->size = 0;
1796 	return fh;
1797 }
1798 EXPORT_SYMBOL_GPL(nfs_alloc_fhandle);
1799 
1800 #ifdef NFS_DEBUG
1801 /*
1802  * _nfs_display_fhandle_hash - calculate the crc32 hash for the filehandle
1803  *                             in the same way that wireshark does
1804  *
1805  * @fh: file handle
1806  *
1807  * For debugging only.
1808  */
1809 u32 _nfs_display_fhandle_hash(const struct nfs_fh *fh)
1810 {
1811 	/* wireshark uses 32-bit AUTODIN crc and does a bitwise
1812 	 * not on the result */
1813 	return nfs_fhandle_hash(fh);
1814 }
1815 EXPORT_SYMBOL_GPL(_nfs_display_fhandle_hash);
1816 
1817 /*
1818  * _nfs_display_fhandle - display an NFS file handle on the console
1819  *
1820  * @fh: file handle to display
1821  * @caption: display caption
1822  *
1823  * For debugging only.
1824  */
1825 void _nfs_display_fhandle(const struct nfs_fh *fh, const char *caption)
1826 {
1827 	unsigned short i;
1828 
1829 	if (fh == NULL || fh->size == 0) {
1830 		printk(KERN_DEFAULT "%s at %p is empty\n", caption, fh);
1831 		return;
1832 	}
1833 
1834 	printk(KERN_DEFAULT "%s at %p is %u bytes, crc: 0x%08x:\n",
1835 	       caption, fh, fh->size, _nfs_display_fhandle_hash(fh));
1836 	for (i = 0; i < fh->size; i += 16) {
1837 		__be32 *pos = (__be32 *)&fh->data[i];
1838 
1839 		switch ((fh->size - i - 1) >> 2) {
1840 		case 0:
1841 			printk(KERN_DEFAULT " %08x\n",
1842 				be32_to_cpup(pos));
1843 			break;
1844 		case 1:
1845 			printk(KERN_DEFAULT " %08x %08x\n",
1846 				be32_to_cpup(pos), be32_to_cpup(pos + 1));
1847 			break;
1848 		case 2:
1849 			printk(KERN_DEFAULT " %08x %08x %08x\n",
1850 				be32_to_cpup(pos), be32_to_cpup(pos + 1),
1851 				be32_to_cpup(pos + 2));
1852 			break;
1853 		default:
1854 			printk(KERN_DEFAULT " %08x %08x %08x %08x\n",
1855 				be32_to_cpup(pos), be32_to_cpup(pos + 1),
1856 				be32_to_cpup(pos + 2), be32_to_cpup(pos + 3));
1857 		}
1858 	}
1859 }
1860 EXPORT_SYMBOL_GPL(_nfs_display_fhandle);
1861 #endif
1862 
1863 /**
1864  * nfs_inode_attrs_cmp_generic - compare attributes
1865  * @fattr: attributes
1866  * @inode: pointer to inode
1867  *
1868  * Attempt to divine whether or not an RPC call reply carrying stale
1869  * attributes got scheduled after another call carrying updated ones.
1870  * Note also the check for wraparound of 'attr_gencount'
1871  *
1872  * The function returns '1' if it thinks the attributes in @fattr are
1873  * more recent than the ones cached in @inode. Otherwise it returns
1874  * the value '0'.
1875  */
1876 static int nfs_inode_attrs_cmp_generic(const struct nfs_fattr *fattr,
1877 				       const struct inode *inode)
1878 {
1879 	unsigned long attr_gencount = NFS_I(inode)->attr_gencount;
1880 
1881 	return (long)(fattr->gencount - attr_gencount) > 0 ||
1882 	       (long)(attr_gencount - nfs_read_attr_generation_counter()) > 0;
1883 }
1884 
1885 /**
1886  * nfs_inode_attrs_cmp_monotonic - compare attributes
1887  * @fattr: attributes
1888  * @inode: pointer to inode
1889  *
1890  * Attempt to divine whether or not an RPC call reply carrying stale
1891  * attributes got scheduled after another call carrying updated ones.
1892  *
1893  * We assume that the server observes monotonic semantics for
1894  * the change attribute, so a larger value means that the attributes in
1895  * @fattr are more recent, in which case the function returns the
1896  * value '1'.
1897  * A return value of '0' indicates no measurable change
1898  * A return value of '-1' means that the attributes in @inode are
1899  * more recent.
1900  */
1901 static int nfs_inode_attrs_cmp_monotonic(const struct nfs_fattr *fattr,
1902 					 const struct inode *inode)
1903 {
1904 	s64 diff = fattr->change_attr - inode_peek_iversion_raw(inode);
1905 	if (diff > 0)
1906 		return 1;
1907 	return diff == 0 ? 0 : -1;
1908 }
1909 
1910 /**
1911  * nfs_inode_attrs_cmp_strict_monotonic - compare attributes
1912  * @fattr: attributes
1913  * @inode: pointer to inode
1914  *
1915  * Attempt to divine whether or not an RPC call reply carrying stale
1916  * attributes got scheduled after another call carrying updated ones.
1917  *
1918  * We assume that the server observes strictly monotonic semantics for
1919  * the change attribute, so a larger value means that the attributes in
1920  * @fattr are more recent, in which case the function returns the
1921  * value '1'.
1922  * A return value of '-1' means that the attributes in @inode are
1923  * more recent or unchanged.
1924  */
1925 static int nfs_inode_attrs_cmp_strict_monotonic(const struct nfs_fattr *fattr,
1926 						const struct inode *inode)
1927 {
1928 	return  nfs_inode_attrs_cmp_monotonic(fattr, inode) > 0 ? 1 : -1;
1929 }
1930 
1931 /**
1932  * nfs_inode_attrs_cmp - compare attributes
1933  * @fattr: attributes
1934  * @inode: pointer to inode
1935  *
1936  * This function returns '1' if it thinks the attributes in @fattr are
1937  * more recent than the ones cached in @inode. It returns '-1' if
1938  * the attributes in @inode are more recent than the ones in @fattr,
1939  * and it returns 0 if not sure.
1940  */
1941 static int nfs_inode_attrs_cmp(const struct nfs_fattr *fattr,
1942 			       const struct inode *inode)
1943 {
1944 	if (nfs_inode_attrs_cmp_generic(fattr, inode) > 0)
1945 		return 1;
1946 	switch (NFS_SERVER(inode)->change_attr_type) {
1947 	case NFS4_CHANGE_TYPE_IS_UNDEFINED:
1948 		break;
1949 	case NFS4_CHANGE_TYPE_IS_TIME_METADATA:
1950 		if (!(fattr->valid & NFS_ATTR_FATTR_CHANGE))
1951 			break;
1952 		return nfs_inode_attrs_cmp_monotonic(fattr, inode);
1953 	default:
1954 		if (!(fattr->valid & NFS_ATTR_FATTR_CHANGE))
1955 			break;
1956 		return nfs_inode_attrs_cmp_strict_monotonic(fattr, inode);
1957 	}
1958 	return 0;
1959 }
1960 
1961 /**
1962  * nfs_inode_finish_partial_attr_update - complete a previous inode update
1963  * @fattr: attributes
1964  * @inode: pointer to inode
1965  *
1966  * Returns '1' if the last attribute update left the inode cached
1967  * attributes in a partially unrevalidated state, and @fattr
1968  * matches the change attribute of that partial update.
1969  * Otherwise returns '0'.
1970  */
1971 static int nfs_inode_finish_partial_attr_update(const struct nfs_fattr *fattr,
1972 						const struct inode *inode)
1973 {
1974 	const unsigned long check_valid =
1975 		NFS_INO_INVALID_ATIME | NFS_INO_INVALID_CTIME |
1976 		NFS_INO_INVALID_MTIME | NFS_INO_INVALID_SIZE |
1977 		NFS_INO_INVALID_BLOCKS | NFS_INO_INVALID_OTHER |
1978 		NFS_INO_INVALID_NLINK | NFS_INO_INVALID_BTIME;
1979 	unsigned long cache_validity = NFS_I(inode)->cache_validity;
1980 	enum nfs4_change_attr_type ctype = NFS_SERVER(inode)->change_attr_type;
1981 
1982 	if (ctype != NFS4_CHANGE_TYPE_IS_UNDEFINED &&
1983 	    !(cache_validity & NFS_INO_INVALID_CHANGE) &&
1984 	    (cache_validity & check_valid) != 0 &&
1985 	    (fattr->valid & NFS_ATTR_FATTR_CHANGE) != 0 &&
1986 	    nfs_inode_attrs_cmp_monotonic(fattr, inode) == 0)
1987 		return 1;
1988 	return 0;
1989 }
1990 
1991 static void nfs_ooo_merge(struct nfs_inode *nfsi,
1992 			  u64 start, u64 end)
1993 {
1994 	int i, cnt;
1995 
1996 	if (nfsi->cache_validity & NFS_INO_DATA_INVAL_DEFER)
1997 		/* No point merging anything */
1998 		return;
1999 
2000 	if (!nfsi->ooo) {
2001 		nfsi->ooo = kmalloc_obj(*nfsi->ooo, GFP_ATOMIC);
2002 		if (!nfsi->ooo) {
2003 			nfsi->cache_validity |= NFS_INO_DATA_INVAL_DEFER;
2004 			return;
2005 		}
2006 		nfsi->ooo->cnt = 0;
2007 	}
2008 
2009 	/* add this range, merging if possible */
2010 	cnt = nfsi->ooo->cnt;
2011 	for (i = 0; i < cnt; i++) {
2012 		if (end == nfsi->ooo->gap[i].start)
2013 			end = nfsi->ooo->gap[i].end;
2014 		else if (start == nfsi->ooo->gap[i].end)
2015 			start = nfsi->ooo->gap[i].start;
2016 		else
2017 			continue;
2018 		/* Remove 'i' from table and loop to insert the new range */
2019 		cnt -= 1;
2020 		nfsi->ooo->gap[i] = nfsi->ooo->gap[cnt];
2021 		i = -1;
2022 	}
2023 	if (start != end) {
2024 		if (cnt >= ARRAY_SIZE(nfsi->ooo->gap)) {
2025 			nfsi->cache_validity |= NFS_INO_DATA_INVAL_DEFER;
2026 			kfree(nfsi->ooo);
2027 			nfsi->ooo = NULL;
2028 			return;
2029 		}
2030 		nfsi->ooo->gap[cnt].start = start;
2031 		nfsi->ooo->gap[cnt].end = end;
2032 		cnt += 1;
2033 	}
2034 	nfsi->ooo->cnt = cnt;
2035 }
2036 
2037 static void nfs_ooo_record(struct nfs_inode *nfsi,
2038 			   struct nfs_fattr *fattr)
2039 {
2040 	/* This reply was out-of-order, so record in the
2041 	 * pre/post change id, possibly cancelling
2042 	 * gaps created when iversion was jumpped forward.
2043 	 */
2044 	if ((fattr->valid & NFS_ATTR_FATTR_CHANGE) &&
2045 	    (fattr->valid & NFS_ATTR_FATTR_PRECHANGE))
2046 		nfs_ooo_merge(nfsi,
2047 			      fattr->change_attr,
2048 			      fattr->pre_change_attr);
2049 }
2050 
2051 static int nfs_refresh_inode_locked(struct inode *inode,
2052 				    struct nfs_fattr *fattr)
2053 {
2054 	int attr_cmp = nfs_inode_attrs_cmp(fattr, inode);
2055 	int ret = 0;
2056 
2057 	trace_nfs_refresh_inode_enter(inode);
2058 
2059 	if (attr_cmp > 0 || nfs_inode_finish_partial_attr_update(fattr, inode))
2060 		ret = nfs_update_inode(inode, fattr);
2061 	else {
2062 		nfs_ooo_record(NFS_I(inode), fattr);
2063 
2064 		if (attr_cmp == 0)
2065 			ret = nfs_check_inode_attributes(inode, fattr);
2066 	}
2067 
2068 	trace_nfs_refresh_inode_exit(inode, ret);
2069 	return ret;
2070 }
2071 
2072 /**
2073  * nfs_refresh_inode - try to update the inode attribute cache
2074  * @inode: pointer to inode
2075  * @fattr: updated attributes
2076  *
2077  * Check that an RPC call that returned attributes has not overlapped with
2078  * other recent updates of the inode metadata, then decide whether it is
2079  * safe to do a full update of the inode attributes, or whether just to
2080  * call nfs_check_inode_attributes.
2081  */
2082 int nfs_refresh_inode(struct inode *inode, struct nfs_fattr *fattr)
2083 {
2084 	int status;
2085 
2086 	if ((fattr->valid & NFS_ATTR_FATTR) == 0)
2087 		return 0;
2088 	spin_lock(&inode->i_lock);
2089 	status = nfs_refresh_inode_locked(inode, fattr);
2090 	spin_unlock(&inode->i_lock);
2091 
2092 	return status;
2093 }
2094 EXPORT_SYMBOL_GPL(nfs_refresh_inode);
2095 
2096 static int nfs_post_op_update_inode_locked(struct inode *inode,
2097 		struct nfs_fattr *fattr, unsigned int invalid)
2098 {
2099 	if (S_ISDIR(inode->i_mode))
2100 		invalid |= NFS_INO_INVALID_DATA;
2101 	nfs_set_cache_invalid(inode, invalid);
2102 	if ((fattr->valid & NFS_ATTR_FATTR) == 0)
2103 		return 0;
2104 	return nfs_refresh_inode_locked(inode, fattr);
2105 }
2106 
2107 /**
2108  * nfs_post_op_update_inode - try to update the inode attribute cache
2109  * @inode: pointer to inode
2110  * @fattr: updated attributes
2111  *
2112  * After an operation that has changed the inode metadata, mark the
2113  * attribute cache as being invalid, then try to update it.
2114  *
2115  * NB: if the server didn't return any post op attributes, this
2116  * function will force the retrieval of attributes before the next
2117  * NFS request.  Thus it should be used only for operations that
2118  * are expected to change one or more attributes, to avoid
2119  * unnecessary NFS requests and trips through nfs_update_inode().
2120  */
2121 int nfs_post_op_update_inode(struct inode *inode, struct nfs_fattr *fattr)
2122 {
2123 	int status;
2124 
2125 	spin_lock(&inode->i_lock);
2126 	nfs_fattr_set_barrier(fattr);
2127 	status = nfs_post_op_update_inode_locked(inode, fattr,
2128 			NFS_INO_INVALID_CHANGE
2129 			| NFS_INO_INVALID_CTIME
2130 			| NFS_INO_REVAL_FORCED);
2131 	spin_unlock(&inode->i_lock);
2132 
2133 	return status;
2134 }
2135 EXPORT_SYMBOL_GPL(nfs_post_op_update_inode);
2136 
2137 /**
2138  * nfs_post_op_update_inode_force_wcc_locked - update the inode attribute cache
2139  * @inode: pointer to inode
2140  * @fattr: updated attributes
2141  *
2142  * After an operation that has changed the inode metadata, mark the
2143  * attribute cache as being invalid, then try to update it. Fake up
2144  * weak cache consistency data, if none exist.
2145  *
2146  * This function is mainly designed to be used by the ->write_done() functions.
2147  */
2148 int nfs_post_op_update_inode_force_wcc_locked(struct inode *inode, struct nfs_fattr *fattr)
2149 {
2150 	int attr_cmp = nfs_inode_attrs_cmp(fattr, inode);
2151 	int status;
2152 
2153 	/* Don't do a WCC update if these attributes are already stale */
2154 	if (attr_cmp < 0)
2155 		return 0;
2156 	if ((fattr->valid & NFS_ATTR_FATTR) == 0 || !attr_cmp) {
2157 		/* Record the pre/post change info before clearing PRECHANGE */
2158 		nfs_ooo_record(NFS_I(inode), fattr);
2159 		fattr->valid &= ~(NFS_ATTR_FATTR_PRECHANGE
2160 				| NFS_ATTR_FATTR_PRESIZE
2161 				| NFS_ATTR_FATTR_PREMTIME
2162 				| NFS_ATTR_FATTR_PRECTIME);
2163 		goto out_noforce;
2164 	}
2165 	if ((fattr->valid & NFS_ATTR_FATTR_CHANGE) != 0 &&
2166 			(fattr->valid & NFS_ATTR_FATTR_PRECHANGE) == 0) {
2167 		fattr->pre_change_attr = inode_peek_iversion_raw(inode);
2168 		fattr->valid |= NFS_ATTR_FATTR_PRECHANGE;
2169 	}
2170 	if ((fattr->valid & NFS_ATTR_FATTR_CTIME) != 0 &&
2171 			(fattr->valid & NFS_ATTR_FATTR_PRECTIME) == 0) {
2172 		fattr->pre_ctime = inode_get_ctime(inode);
2173 		fattr->valid |= NFS_ATTR_FATTR_PRECTIME;
2174 	}
2175 	if ((fattr->valid & NFS_ATTR_FATTR_MTIME) != 0 &&
2176 			(fattr->valid & NFS_ATTR_FATTR_PREMTIME) == 0) {
2177 		fattr->pre_mtime = inode_get_mtime(inode);
2178 		fattr->valid |= NFS_ATTR_FATTR_PREMTIME;
2179 	}
2180 	if ((fattr->valid & NFS_ATTR_FATTR_SIZE) != 0 &&
2181 			(fattr->valid & NFS_ATTR_FATTR_PRESIZE) == 0) {
2182 		fattr->pre_size = i_size_read(inode);
2183 		fattr->valid |= NFS_ATTR_FATTR_PRESIZE;
2184 	}
2185 out_noforce:
2186 	status = nfs_post_op_update_inode_locked(inode, fattr,
2187 			NFS_INO_INVALID_CHANGE
2188 			| NFS_INO_INVALID_CTIME
2189 			| NFS_INO_INVALID_MTIME
2190 			| NFS_INO_INVALID_BLOCKS);
2191 	return status;
2192 }
2193 
2194 /**
2195  * nfs_post_op_update_inode_force_wcc - try to update the inode attribute cache
2196  * @inode: pointer to inode
2197  * @fattr: updated attributes
2198  *
2199  * After an operation that has changed the inode metadata, mark the
2200  * attribute cache as being invalid, then try to update it. Fake up
2201  * weak cache consistency data, if none exist.
2202  *
2203  * This function is mainly designed to be used by the ->write_done() functions.
2204  */
2205 int nfs_post_op_update_inode_force_wcc(struct inode *inode, struct nfs_fattr *fattr)
2206 {
2207 	int status;
2208 
2209 	spin_lock(&inode->i_lock);
2210 	nfs_fattr_set_barrier(fattr);
2211 	status = nfs_post_op_update_inode_force_wcc_locked(inode, fattr);
2212 	spin_unlock(&inode->i_lock);
2213 	return status;
2214 }
2215 EXPORT_SYMBOL_GPL(nfs_post_op_update_inode_force_wcc);
2216 
2217 
2218 /*
2219  * Many nfs protocol calls return the new file attributes after
2220  * an operation.  Here we update the inode to reflect the state
2221  * of the server's inode.
2222  *
2223  * This is a bit tricky because we have to make sure all dirty pages
2224  * have been sent off to the server before calling invalidate_inode_pages.
2225  * To make sure no other process adds more write requests while we try
2226  * our best to flush them, we make them sleep during the attribute refresh.
2227  *
2228  * A very similar scenario holds for the dir cache.
2229  */
2230 static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
2231 {
2232 	struct nfs_server *server = NFS_SERVER(inode);
2233 	struct nfs_inode *nfsi = NFS_I(inode);
2234 	loff_t cur_isize, new_isize;
2235 	u64 fattr_supported = server->fattr_valid;
2236 	unsigned long invalid = 0;
2237 	unsigned long now = jiffies;
2238 	unsigned long save_cache_validity;
2239 	bool have_writers = nfs_file_has_buffered_writers(nfsi);
2240 	bool cache_revalidated = true;
2241 	bool attr_changed = false;
2242 	bool have_delegation;
2243 
2244 	dfprintk(VFS, "NFS: %s(%s/%llu fh_crc=0x%08x ct=%d info=0x%llx)\n",
2245 			__func__, inode->i_sb->s_id, inode->i_ino,
2246 			nfs_display_fhandle_hash(NFS_FH(inode)),
2247 			icount_read_once(inode), fattr->valid);
2248 
2249 	if (!(fattr->valid & NFS_ATTR_FATTR_FILEID)) {
2250 		/* Only a mounted-on-fileid? Just exit */
2251 		if (fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID)
2252 			return 0;
2253 	/* Has the inode gone and changed behind our back? */
2254 	} else if (inode->i_ino != fattr->fileid) {
2255 		/* Is this perhaps the mounted-on fileid? */
2256 		if ((fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID) &&
2257 		    inode->i_ino == fattr->mounted_on_fileid)
2258 			return 0;
2259 		printk(KERN_ERR "NFS: server %s error: fileid changed\n"
2260 			"fsid %s: expected fileid 0x%Lx, got 0x%Lx\n",
2261 			NFS_SERVER(inode)->nfs_client->cl_hostname,
2262 			inode->i_sb->s_id, (long long)inode->i_ino,
2263 			(long long)fattr->fileid);
2264 		goto out_err;
2265 	}
2266 
2267 	/*
2268 	 * Make sure the inode's type hasn't changed.
2269 	 */
2270 	if ((fattr->valid & NFS_ATTR_FATTR_TYPE) && inode_wrong_type(inode, fattr->mode)) {
2271 		/*
2272 		* Big trouble! The inode has become a different object.
2273 		*/
2274 		printk(KERN_DEBUG "NFS: %s: inode %llu mode changed, %07o to %07o\n",
2275 				__func__, inode->i_ino, inode->i_mode, fattr->mode);
2276 		goto out_err;
2277 	}
2278 
2279 	/* Update the fsid? */
2280 	if (S_ISDIR(inode->i_mode) && (fattr->valid & NFS_ATTR_FATTR_FSID) &&
2281 			!nfs_fsid_equal(&server->fsid, &fattr->fsid) &&
2282 			!IS_AUTOMOUNT(inode))
2283 		server->fsid = fattr->fsid;
2284 
2285 	/* Save the delegation state before clearing cache_validity */
2286 	have_delegation = nfs_have_delegated_attributes(inode);
2287 
2288 	/*
2289 	 * Update the read time so we don't revalidate too often.
2290 	 */
2291 	nfsi->read_cache_jiffies = fattr->time_start;
2292 
2293 	/* Fix up any delegated attributes in the struct nfs_fattr */
2294 	nfs_fattr_fixup_delegated(inode, fattr);
2295 
2296 	save_cache_validity = nfsi->cache_validity;
2297 	nfsi->cache_validity &= ~(NFS_INO_INVALID_ATTR
2298 			| NFS_INO_INVALID_ATIME
2299 			| NFS_INO_REVAL_FORCED
2300 			| NFS_INO_INVALID_BLOCKS);
2301 
2302 	/* Do atomic weak cache consistency updates */
2303 	nfs_wcc_update_inode(inode, fattr);
2304 
2305 	if (pnfs_layoutcommit_outstanding(inode)) {
2306 		nfsi->cache_validity |=
2307 			save_cache_validity &
2308 			(NFS_INO_INVALID_CHANGE | NFS_INO_INVALID_CTIME |
2309 			 NFS_INO_INVALID_MTIME | NFS_INO_INVALID_SIZE |
2310 			 NFS_INO_INVALID_BLOCKS);
2311 		cache_revalidated = false;
2312 	}
2313 
2314 	/* More cache consistency checks */
2315 	if (fattr->valid & NFS_ATTR_FATTR_CHANGE) {
2316 		if (!have_writers && nfsi->ooo && nfsi->ooo->cnt == 1 &&
2317 		    nfsi->ooo->gap[0].end == inode_peek_iversion_raw(inode)) {
2318 			/* There is one remaining gap that hasn't been
2319 			 * merged into iversion - do that now.
2320 			 */
2321 			inode_set_iversion_raw(inode, nfsi->ooo->gap[0].start);
2322 			kfree(nfsi->ooo);
2323 			nfsi->ooo = NULL;
2324 		}
2325 		if (!inode_eq_iversion_raw(inode, fattr->change_attr)) {
2326 			/* Could it be a race with writeback? */
2327 			if (!(have_writers || have_delegation)) {
2328 				invalid |= NFS_INO_INVALID_DATA
2329 					| NFS_INO_INVALID_ACCESS
2330 					| NFS_INO_INVALID_ACL
2331 					| NFS_INO_INVALID_XATTR;
2332 				/* Force revalidate of all attributes */
2333 				save_cache_validity |= NFS_INO_INVALID_CTIME
2334 					| NFS_INO_INVALID_MTIME
2335 					| NFS_INO_INVALID_SIZE
2336 					| NFS_INO_INVALID_BLOCKS
2337 					| NFS_INO_INVALID_NLINK
2338 					| NFS_INO_INVALID_MODE
2339 					| NFS_INO_INVALID_OTHER
2340 					| NFS_INO_INVALID_BTIME;
2341 				if (S_ISDIR(inode->i_mode))
2342 					nfs_force_lookup_revalidate(inode);
2343 				attr_changed = true;
2344 				dprintk("NFS: change_attr change on server for file %s/%llu\n",
2345 						inode->i_sb->s_id,
2346 						inode->i_ino);
2347 			} else if (!have_delegation) {
2348 				nfs_ooo_record(nfsi, fattr);
2349 				nfs_ooo_merge(nfsi, inode_peek_iversion_raw(inode),
2350 					      fattr->change_attr);
2351 			}
2352 			inode_set_iversion_raw(inode, fattr->change_attr);
2353 		}
2354 	} else {
2355 		nfsi->cache_validity |=
2356 			save_cache_validity & NFS_INO_INVALID_CHANGE;
2357 		if (!have_delegation ||
2358 		    (nfsi->cache_validity & NFS_INO_INVALID_CHANGE) != 0)
2359 			cache_revalidated = false;
2360 	}
2361 
2362 	if (fattr->valid & NFS_ATTR_FATTR_MTIME)
2363 		inode_set_mtime_to_ts(inode, fattr->mtime);
2364 	else if (fattr_supported & NFS_ATTR_FATTR_MTIME)
2365 		nfsi->cache_validity |=
2366 			save_cache_validity & NFS_INO_INVALID_MTIME;
2367 
2368 	if (fattr->valid & NFS_ATTR_FATTR_CTIME)
2369 		inode_set_ctime_to_ts(inode, fattr->ctime);
2370 	else if (fattr_supported & NFS_ATTR_FATTR_CTIME)
2371 		nfsi->cache_validity |=
2372 			save_cache_validity & NFS_INO_INVALID_CTIME;
2373 
2374 	if (fattr->valid & NFS_ATTR_FATTR_BTIME)
2375 		nfsi->btime = fattr->btime;
2376 	else if (fattr_supported & NFS_ATTR_FATTR_BTIME)
2377 		nfsi->cache_validity |=
2378 			save_cache_validity & NFS_INO_INVALID_BTIME;
2379 
2380 	/* Check if our cached file size is stale */
2381 	if (fattr->valid & NFS_ATTR_FATTR_SIZE) {
2382 		new_isize = nfs_size_to_loff_t(fattr->size);
2383 		cur_isize = i_size_read(inode);
2384 		if (new_isize != cur_isize && !have_delegation) {
2385 			/* Do we perhaps have any outstanding writes, or has
2386 			 * the file grown beyond our last write? */
2387 			if (!nfs_have_writebacks(inode) || new_isize > cur_isize) {
2388 				trace_nfs_size_update(inode, new_isize);
2389 				i_size_write(inode, new_isize);
2390 				if (!have_writers)
2391 					invalid |= NFS_INO_INVALID_DATA;
2392 			}
2393 		}
2394 		if (new_isize == 0 &&
2395 		    !(fattr->valid & (NFS_ATTR_FATTR_SPACE_USED |
2396 				      NFS_ATTR_FATTR_BLOCKS_USED))) {
2397 			fattr->du.nfs3.used = 0;
2398 			fattr->valid |= NFS_ATTR_FATTR_SPACE_USED;
2399 		}
2400 	} else
2401 		nfsi->cache_validity |=
2402 			save_cache_validity & NFS_INO_INVALID_SIZE;
2403 
2404 	if (fattr->valid & NFS_ATTR_FATTR_ATIME)
2405 		inode_set_atime_to_ts(inode, fattr->atime);
2406 	else if (fattr_supported & NFS_ATTR_FATTR_ATIME)
2407 		nfsi->cache_validity |=
2408 			save_cache_validity & NFS_INO_INVALID_ATIME;
2409 
2410 	if (fattr->valid & NFS_ATTR_FATTR_MODE) {
2411 		if ((inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO)) {
2412 			umode_t newmode = inode->i_mode & S_IFMT;
2413 			newmode |= fattr->mode & S_IALLUGO;
2414 			inode->i_mode = newmode;
2415 			invalid |= NFS_INO_INVALID_ACCESS
2416 				| NFS_INO_INVALID_ACL;
2417 		}
2418 	} else if (fattr_supported & NFS_ATTR_FATTR_MODE)
2419 		nfsi->cache_validity |=
2420 			save_cache_validity & NFS_INO_INVALID_MODE;
2421 
2422 	if (fattr->valid & NFS_ATTR_FATTR_OWNER) {
2423 		if (!uid_eq(inode->i_uid, fattr->uid)) {
2424 			invalid |= NFS_INO_INVALID_ACCESS
2425 				| NFS_INO_INVALID_ACL;
2426 			inode->i_uid = fattr->uid;
2427 		}
2428 	} else if (fattr_supported & NFS_ATTR_FATTR_OWNER)
2429 		nfsi->cache_validity |=
2430 			save_cache_validity & NFS_INO_INVALID_OTHER;
2431 
2432 	if (fattr->valid & NFS_ATTR_FATTR_GROUP) {
2433 		if (!gid_eq(inode->i_gid, fattr->gid)) {
2434 			invalid |= NFS_INO_INVALID_ACCESS
2435 				| NFS_INO_INVALID_ACL;
2436 			inode->i_gid = fattr->gid;
2437 		}
2438 	} else if (fattr_supported & NFS_ATTR_FATTR_GROUP)
2439 		nfsi->cache_validity |=
2440 			save_cache_validity & NFS_INO_INVALID_OTHER;
2441 
2442 	if (fattr->valid & NFS_ATTR_FATTR_NLINK) {
2443 		if (inode->i_nlink != fattr->nlink)
2444 			set_nlink(inode, fattr->nlink);
2445 	} else if (fattr_supported & NFS_ATTR_FATTR_NLINK)
2446 		nfsi->cache_validity |=
2447 			save_cache_validity & NFS_INO_INVALID_NLINK;
2448 
2449 	if (fattr->valid & NFS_ATTR_FATTR_SPACE_USED) {
2450 		/*
2451 		 * report the blocks in 512byte units
2452 		 */
2453 		inode->i_blocks = nfs_calc_block_size(fattr->du.nfs3.used);
2454 	} else if (fattr_supported & NFS_ATTR_FATTR_SPACE_USED)
2455 		nfsi->cache_validity |=
2456 			save_cache_validity & NFS_INO_INVALID_BLOCKS;
2457 
2458 	if (fattr->valid & NFS_ATTR_FATTR_BLOCKS_USED)
2459 		inode->i_blocks = fattr->du.nfs2.blocks;
2460 	else if (fattr_supported & NFS_ATTR_FATTR_BLOCKS_USED)
2461 		nfsi->cache_validity |=
2462 			save_cache_validity & NFS_INO_INVALID_BLOCKS;
2463 
2464 	/* Update attrtimeo value if we're out of the unstable period */
2465 	if (attr_changed) {
2466 		nfs_inc_stats(inode, NFSIOS_ATTRINVALIDATE);
2467 		nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
2468 		nfsi->attrtimeo_timestamp = now;
2469 		/* Set barrier to be more recent than all outstanding updates */
2470 		nfsi->attr_gencount = nfs_inc_attr_generation_counter();
2471 	} else {
2472 		if (cache_revalidated) {
2473 			if (!time_in_range_open(now, nfsi->attrtimeo_timestamp,
2474 				nfsi->attrtimeo_timestamp + nfsi->attrtimeo)) {
2475 				nfsi->attrtimeo <<= 1;
2476 				if (nfsi->attrtimeo > NFS_MAXATTRTIMEO(inode))
2477 					nfsi->attrtimeo = NFS_MAXATTRTIMEO(inode);
2478 			}
2479 			nfsi->attrtimeo_timestamp = now;
2480 		}
2481 		/* Set the barrier to be more recent than this fattr */
2482 		if ((long)(fattr->gencount - nfsi->attr_gencount) > 0)
2483 			nfsi->attr_gencount = fattr->gencount;
2484 	}
2485 
2486 	/* Don't invalidate the data if we were to blame */
2487 	if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)
2488 				|| S_ISLNK(inode->i_mode)))
2489 		invalid &= ~NFS_INO_INVALID_DATA;
2490 	nfs_set_cache_invalid(inode, invalid);
2491 
2492 	return 0;
2493  out_err:
2494 	/*
2495 	 * No need to worry about unhashing the dentry, as the
2496 	 * lookup validation will know that the inode is bad.
2497 	 * (But we fall through to invalidate the caches.)
2498 	 */
2499 	nfs_set_inode_stale_locked(inode);
2500 	return -ESTALE;
2501 }
2502 
2503 struct inode *nfs_alloc_inode(struct super_block *sb)
2504 {
2505 	struct nfs_inode *nfsi;
2506 	nfsi = alloc_inode_sb(sb, nfs_inode_cachep, GFP_KERNEL);
2507 	if (!nfsi)
2508 		return NULL;
2509 	nfsi->flags = 0UL;
2510 	nfsi->cache_validity = 0UL;
2511 	nfsi->ooo = NULL;
2512 #if IS_ENABLED(CONFIG_NFS_V4)
2513 	nfsi->nfs4_acl = NULL;
2514 #endif /* CONFIG_NFS_V4 */
2515 #ifdef CONFIG_NFS_V4_2
2516 	nfsi->xattr_cache = NULL;
2517 #endif
2518 	nfs_netfs_inode_init(nfsi);
2519 
2520 	return &nfsi->vfs_inode;
2521 }
2522 EXPORT_SYMBOL_GPL(nfs_alloc_inode);
2523 
2524 void nfs_free_inode(struct inode *inode)
2525 {
2526 	kfree(NFS_I(inode)->ooo);
2527 	kmem_cache_free(nfs_inode_cachep, NFS_I(inode));
2528 }
2529 EXPORT_SYMBOL_GPL(nfs_free_inode);
2530 
2531 static inline void nfs4_init_once(struct nfs_inode *nfsi)
2532 {
2533 #if IS_ENABLED(CONFIG_NFS_V4)
2534 	INIT_LIST_HEAD(&nfsi->open_states);
2535 	nfsi->delegation = NULL;
2536 	init_rwsem(&nfsi->rwsem);
2537 	nfsi->layout = NULL;
2538 #endif
2539 }
2540 
2541 static void init_once(void *foo)
2542 {
2543 	struct nfs_inode *nfsi = foo;
2544 
2545 	inode_init_once(&nfsi->vfs_inode);
2546 	INIT_LIST_HEAD(&nfsi->open_files);
2547 	INIT_LIST_HEAD(&nfsi->access_cache_entry_lru);
2548 	INIT_LIST_HEAD(&nfsi->access_cache_inode_lru);
2549 	nfs4_init_once(nfsi);
2550 }
2551 
2552 static int __init nfs_init_inodecache(void)
2553 {
2554 	nfs_inode_cachep = kmem_cache_create("nfs_inode_cache",
2555 					     sizeof(struct nfs_inode),
2556 					     0, (SLAB_RECLAIM_ACCOUNT|
2557 						SLAB_ACCOUNT),
2558 					     init_once);
2559 	if (nfs_inode_cachep == NULL)
2560 		return -ENOMEM;
2561 
2562 	return 0;
2563 }
2564 
2565 static void nfs_destroy_inodecache(void)
2566 {
2567 	/*
2568 	 * Make sure all delayed rcu free inodes are flushed before we
2569 	 * destroy cache.
2570 	 */
2571 	rcu_barrier();
2572 	kmem_cache_destroy(nfs_inode_cachep);
2573 }
2574 
2575 struct workqueue_struct *nfslocaliod_workqueue;
2576 struct workqueue_struct *nfsiod_workqueue;
2577 EXPORT_SYMBOL_GPL(nfsiod_workqueue);
2578 
2579 /*
2580  * Destroy the nfsiod workqueues
2581  */
2582 static void nfsiod_stop(void)
2583 {
2584 	struct workqueue_struct *wq;
2585 
2586 	wq = nfsiod_workqueue;
2587 	if (wq != NULL) {
2588 		nfsiod_workqueue = NULL;
2589 		destroy_workqueue(wq);
2590 	}
2591 #if IS_ENABLED(CONFIG_NFS_LOCALIO)
2592 	wq = nfslocaliod_workqueue;
2593 	if (wq != NULL) {
2594 		nfslocaliod_workqueue = NULL;
2595 		destroy_workqueue(wq);
2596 	}
2597 #endif /* CONFIG_NFS_LOCALIO */
2598 }
2599 
2600 /*
2601  * Start the nfsiod workqueues
2602  */
2603 static int nfsiod_start(void)
2604 {
2605 	dprintk("RPC:       creating workqueue nfsiod\n");
2606 	nfsiod_workqueue = alloc_workqueue("nfsiod", WQ_MEM_RECLAIM | WQ_UNBOUND, 0);
2607 	if (nfsiod_workqueue == NULL)
2608 		return -ENOMEM;
2609 #if IS_ENABLED(CONFIG_NFS_LOCALIO)
2610 	/*
2611 	 * localio writes need to use a normal (non-memreclaim) workqueue.
2612 	 * When we start getting low on space, XFS goes and calls flush_work() on
2613 	 * a non-memreclaim work queue, which causes a priority inversion problem.
2614 	 */
2615 	dprintk("RPC:       creating workqueue nfslocaliod\n");
2616 	nfslocaliod_workqueue = alloc_workqueue("nfslocaliod", WQ_UNBOUND, 0);
2617 	if (unlikely(nfslocaliod_workqueue == NULL)) {
2618 		nfsiod_stop();
2619 		return -ENOMEM;
2620 	}
2621 #endif /* CONFIG_NFS_LOCALIO */
2622 	return 0;
2623 }
2624 
2625 unsigned int nfs_net_id;
2626 EXPORT_SYMBOL_GPL(nfs_net_id);
2627 
2628 static int nfs_net_init(struct net *net)
2629 {
2630 	struct nfs_net *nn = net_generic(net, nfs_net_id);
2631 	int err;
2632 
2633 	nfs_clients_init(net);
2634 
2635 	if (!rpc_proc_register(net, &nn->rpcstats)) {
2636 		err = -ENOMEM;
2637 		goto err_proc_rpc;
2638 	}
2639 
2640 	err = nfs_fs_proc_net_init(net);
2641 	if (err)
2642 		goto err_proc_nfs;
2643 
2644 	return 0;
2645 
2646 err_proc_nfs:
2647 	rpc_proc_unregister(net, "nfs");
2648 err_proc_rpc:
2649 	nfs_clients_exit(net);
2650 	return err;
2651 }
2652 
2653 static void nfs_net_exit(struct net *net)
2654 {
2655 	rpc_proc_unregister(net, "nfs");
2656 	nfs_fs_proc_net_exit(net);
2657 	nfs_clients_exit(net);
2658 }
2659 
2660 static struct pernet_operations nfs_net_ops = {
2661 	.init = nfs_net_init,
2662 	.exit = nfs_net_exit,
2663 	.id   = &nfs_net_id,
2664 	.size = sizeof(struct nfs_net),
2665 };
2666 
2667 #ifdef CONFIG_KEYS
2668 static struct key *nfs_keyring;
2669 
2670 static int __init nfs_init_keyring(void)
2671 {
2672 	nfs_keyring = keyring_alloc(".nfs",
2673 			     GLOBAL_ROOT_UID, GLOBAL_ROOT_GID,
2674 			     current_cred(),
2675 			     (KEY_POS_ALL & ~KEY_POS_SETATTR) |
2676 			     (KEY_USR_ALL & ~KEY_USR_SETATTR),
2677 			     KEY_ALLOC_NOT_IN_QUOTA, NULL, NULL);
2678 	return PTR_ERR_OR_ZERO(nfs_keyring);
2679 }
2680 
2681 static void nfs_exit_keyring(void)
2682 {
2683 	key_put(nfs_keyring);
2684 }
2685 #else
2686 static inline int nfs_init_keyring(void)
2687 {
2688 	return 0;
2689 }
2690 
2691 static inline void nfs_exit_keyring(void)
2692 {
2693 }
2694 #endif /* CONFIG_KEYS */
2695 
2696 /*
2697  * Initialize NFS
2698  */
2699 static int __init init_nfs_fs(void)
2700 {
2701 	int err;
2702 
2703 	err = nfs_init_keyring();
2704 	if (err)
2705 		return err;
2706 
2707 	err = nfs_sysfs_init();
2708 	if (err < 0)
2709 		goto out10;
2710 
2711 	err = register_pernet_subsys(&nfs_net_ops);
2712 	if (err < 0)
2713 		goto out9;
2714 
2715 	err = nfsiod_start();
2716 	if (err)
2717 		goto out7;
2718 
2719 	err = nfs_fs_proc_init();
2720 	if (err)
2721 		goto out6;
2722 
2723 	err = nfs_init_nfspagecache();
2724 	if (err)
2725 		goto out5;
2726 
2727 	err = nfs_init_inodecache();
2728 	if (err)
2729 		goto out4;
2730 
2731 	err = nfs_init_readpagecache();
2732 	if (err)
2733 		goto out3;
2734 
2735 	err = nfs_init_writepagecache();
2736 	if (err)
2737 		goto out2;
2738 
2739 	err = nfs_init_directcache();
2740 	if (err)
2741 		goto out1;
2742 
2743 	err = register_nfs_fs();
2744 	if (err)
2745 		goto out0;
2746 
2747 	return 0;
2748 out0:
2749 	nfs_destroy_directcache();
2750 out1:
2751 	nfs_destroy_writepagecache();
2752 out2:
2753 	nfs_destroy_readpagecache();
2754 out3:
2755 	nfs_destroy_inodecache();
2756 out4:
2757 	nfs_destroy_nfspagecache();
2758 out5:
2759 	nfs_fs_proc_exit();
2760 out6:
2761 	nfsiod_stop();
2762 out7:
2763 	unregister_pernet_subsys(&nfs_net_ops);
2764 out9:
2765 	nfs_sysfs_exit();
2766 out10:
2767 	nfs_exit_keyring();
2768 	return err;
2769 }
2770 
2771 static void __exit exit_nfs_fs(void)
2772 {
2773 	nfs_destroy_directcache();
2774 	nfs_destroy_writepagecache();
2775 	nfs_destroy_readpagecache();
2776 	nfs_destroy_inodecache();
2777 	nfs_destroy_nfspagecache();
2778 	unregister_pernet_subsys(&nfs_net_ops);
2779 	unregister_nfs_fs();
2780 	nfs_fs_proc_exit();
2781 	nfsiod_stop();
2782 	nfs_sysfs_exit();
2783 	nfs_exit_keyring();
2784 }
2785 
2786 /* Not quite true; I just maintain it */
2787 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
2788 MODULE_DESCRIPTION("NFS client support");
2789 MODULE_LICENSE("GPL");
2790 module_param_cb(enable_ino64, &param_ops_enable_ino64, &enable_ino64, 0644);
2791 
2792 module_init(init_nfs_fs)
2793 module_exit(exit_nfs_fs)
2794