xref: /linux/fs/nfs/inode.c (revision 21ab7031cbff8c6b6f608234e18ffe0473e98f9d)
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 
45 #include "nfs4_fs.h"
46 #include "callback.h"
47 #include "delegation.h"
48 #include "iostat.h"
49 #include "internal.h"
50 #include "fscache.h"
51 #include "pnfs.h"
52 #include "nfs.h"
53 #include "netns.h"
54 #include "sysfs.h"
55 
56 #include "nfstrace.h"
57 
58 #define NFSDBG_FACILITY		NFSDBG_VFS
59 
60 #define NFS_64_BIT_INODE_NUMBERS_ENABLED	1
61 
62 /* Default is to see 64-bit inode numbers */
63 static bool enable_ino64 = NFS_64_BIT_INODE_NUMBERS_ENABLED;
64 
65 static int nfs_update_inode(struct inode *, struct nfs_fattr *);
66 
67 static struct kmem_cache * nfs_inode_cachep;
68 
69 static inline unsigned long
70 nfs_fattr_to_ino_t(struct nfs_fattr *fattr)
71 {
72 	return nfs_fileid_to_ino_t(fattr->fileid);
73 }
74 
75 int nfs_wait_bit_killable(struct wait_bit_key *key, int mode)
76 {
77 	schedule();
78 	if (signal_pending_state(mode, current))
79 		return -ERESTARTSYS;
80 	return 0;
81 }
82 EXPORT_SYMBOL_GPL(nfs_wait_bit_killable);
83 
84 /**
85  * nfs_compat_user_ino64 - returns the user-visible inode number
86  * @fileid: 64-bit fileid
87  *
88  * This function returns a 32-bit inode number if the boot parameter
89  * nfs.enable_ino64 is zero.
90  */
91 u64 nfs_compat_user_ino64(u64 fileid)
92 {
93 #ifdef CONFIG_COMPAT
94 	compat_ulong_t ino;
95 #else
96 	unsigned long ino;
97 #endif
98 
99 	if (enable_ino64)
100 		return fileid;
101 	ino = fileid;
102 	if (sizeof(ino) < sizeof(fileid))
103 		ino ^= fileid >> (sizeof(fileid)-sizeof(ino)) * 8;
104 	return ino;
105 }
106 
107 int nfs_drop_inode(struct inode *inode)
108 {
109 	return NFS_STALE(inode) || generic_drop_inode(inode);
110 }
111 EXPORT_SYMBOL_GPL(nfs_drop_inode);
112 
113 void nfs_clear_inode(struct inode *inode)
114 {
115 	/*
116 	 * The following should never happen...
117 	 */
118 	WARN_ON_ONCE(nfs_have_writebacks(inode));
119 	WARN_ON_ONCE(!list_empty(&NFS_I(inode)->open_files));
120 	nfs_zap_acl_cache(inode);
121 	nfs_access_zap_cache(inode);
122 	nfs_fscache_clear_inode(inode);
123 }
124 EXPORT_SYMBOL_GPL(nfs_clear_inode);
125 
126 void nfs_evict_inode(struct inode *inode)
127 {
128 	truncate_inode_pages_final(&inode->i_data);
129 	clear_inode(inode);
130 	nfs_clear_inode(inode);
131 }
132 
133 int nfs_sync_inode(struct inode *inode)
134 {
135 	inode_dio_wait(inode);
136 	return nfs_wb_all(inode);
137 }
138 EXPORT_SYMBOL_GPL(nfs_sync_inode);
139 
140 /**
141  * nfs_sync_mapping - helper to flush all mmapped dirty data to disk
142  * @mapping: pointer to struct address_space
143  */
144 int nfs_sync_mapping(struct address_space *mapping)
145 {
146 	int ret = 0;
147 
148 	if (mapping->nrpages != 0) {
149 		unmap_mapping_range(mapping, 0, 0, 0);
150 		ret = nfs_wb_all(mapping->host);
151 	}
152 	return ret;
153 }
154 
155 static int nfs_attribute_timeout(struct inode *inode)
156 {
157 	struct nfs_inode *nfsi = NFS_I(inode);
158 
159 	return !time_in_range_open(jiffies, nfsi->read_cache_jiffies, nfsi->read_cache_jiffies + nfsi->attrtimeo);
160 }
161 
162 static bool nfs_check_cache_flags_invalid(struct inode *inode,
163 					  unsigned long flags)
164 {
165 	unsigned long cache_validity = READ_ONCE(NFS_I(inode)->cache_validity);
166 
167 	return (cache_validity & flags) != 0;
168 }
169 
170 bool nfs_check_cache_invalid(struct inode *inode, unsigned long flags)
171 {
172 	if (nfs_check_cache_flags_invalid(inode, flags))
173 		return true;
174 	return nfs_attribute_cache_expired(inode);
175 }
176 EXPORT_SYMBOL_GPL(nfs_check_cache_invalid);
177 
178 #ifdef CONFIG_NFS_V4_2
179 static bool nfs_has_xattr_cache(const struct nfs_inode *nfsi)
180 {
181 	return nfsi->xattr_cache != NULL;
182 }
183 #else
184 static bool nfs_has_xattr_cache(const struct nfs_inode *nfsi)
185 {
186 	return false;
187 }
188 #endif
189 
190 void nfs_set_cache_invalid(struct inode *inode, unsigned long flags)
191 {
192 	struct nfs_inode *nfsi = NFS_I(inode);
193 	bool have_delegation = NFS_PROTO(inode)->have_delegation(inode, FMODE_READ);
194 
195 	if (have_delegation) {
196 		if (!(flags & NFS_INO_REVAL_FORCED))
197 			flags &= ~(NFS_INO_INVALID_MODE |
198 				   NFS_INO_INVALID_OTHER |
199 				   NFS_INO_INVALID_XATTR);
200 		flags &= ~(NFS_INO_INVALID_CHANGE | NFS_INO_INVALID_SIZE);
201 	}
202 
203 	if (!nfs_has_xattr_cache(nfsi))
204 		flags &= ~NFS_INO_INVALID_XATTR;
205 	if (flags & NFS_INO_INVALID_DATA)
206 		nfs_fscache_invalidate(inode, 0);
207 	flags &= ~NFS_INO_REVAL_FORCED;
208 
209 	nfsi->cache_validity |= flags;
210 
211 	if (inode->i_mapping->nrpages == 0)
212 		nfsi->cache_validity &= ~(NFS_INO_INVALID_DATA |
213 					  NFS_INO_DATA_INVAL_DEFER);
214 	else if (nfsi->cache_validity & NFS_INO_INVALID_DATA)
215 		nfsi->cache_validity &= ~NFS_INO_DATA_INVAL_DEFER;
216 	trace_nfs_set_cache_invalid(inode, 0);
217 }
218 EXPORT_SYMBOL_GPL(nfs_set_cache_invalid);
219 
220 /*
221  * Invalidate the local caches
222  */
223 static void nfs_zap_caches_locked(struct inode *inode)
224 {
225 	struct nfs_inode *nfsi = NFS_I(inode);
226 	int mode = inode->i_mode;
227 
228 	nfs_inc_stats(inode, NFSIOS_ATTRINVALIDATE);
229 
230 	nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
231 	nfsi->attrtimeo_timestamp = jiffies;
232 
233 	if (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))
234 		nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR |
235 						     NFS_INO_INVALID_DATA |
236 						     NFS_INO_INVALID_ACCESS |
237 						     NFS_INO_INVALID_ACL |
238 						     NFS_INO_INVALID_XATTR);
239 	else
240 		nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR |
241 						     NFS_INO_INVALID_ACCESS |
242 						     NFS_INO_INVALID_ACL |
243 						     NFS_INO_INVALID_XATTR);
244 	nfs_zap_label_cache_locked(nfsi);
245 }
246 
247 void nfs_zap_caches(struct inode *inode)
248 {
249 	spin_lock(&inode->i_lock);
250 	nfs_zap_caches_locked(inode);
251 	spin_unlock(&inode->i_lock);
252 }
253 
254 void nfs_zap_mapping(struct inode *inode, struct address_space *mapping)
255 {
256 	if (mapping->nrpages != 0) {
257 		spin_lock(&inode->i_lock);
258 		nfs_set_cache_invalid(inode, NFS_INO_INVALID_DATA);
259 		spin_unlock(&inode->i_lock);
260 	}
261 }
262 
263 void nfs_zap_acl_cache(struct inode *inode)
264 {
265 	void (*clear_acl_cache)(struct inode *);
266 
267 	clear_acl_cache = NFS_PROTO(inode)->clear_acl_cache;
268 	if (clear_acl_cache != NULL)
269 		clear_acl_cache(inode);
270 	spin_lock(&inode->i_lock);
271 	NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_ACL;
272 	spin_unlock(&inode->i_lock);
273 }
274 EXPORT_SYMBOL_GPL(nfs_zap_acl_cache);
275 
276 void nfs_invalidate_atime(struct inode *inode)
277 {
278 	spin_lock(&inode->i_lock);
279 	nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATIME);
280 	spin_unlock(&inode->i_lock);
281 }
282 EXPORT_SYMBOL_GPL(nfs_invalidate_atime);
283 
284 /*
285  * Invalidate, but do not unhash, the inode.
286  * NB: must be called with inode->i_lock held!
287  */
288 static void nfs_set_inode_stale_locked(struct inode *inode)
289 {
290 	set_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
291 	nfs_zap_caches_locked(inode);
292 	trace_nfs_set_inode_stale(inode);
293 }
294 
295 void nfs_set_inode_stale(struct inode *inode)
296 {
297 	spin_lock(&inode->i_lock);
298 	nfs_set_inode_stale_locked(inode);
299 	spin_unlock(&inode->i_lock);
300 }
301 
302 struct nfs_find_desc {
303 	struct nfs_fh		*fh;
304 	struct nfs_fattr	*fattr;
305 };
306 
307 /*
308  * In NFSv3 we can have 64bit inode numbers. In order to support
309  * this, and re-exported directories (also seen in NFSv2)
310  * we are forced to allow 2 different inodes to have the same
311  * i_ino.
312  */
313 static int
314 nfs_find_actor(struct inode *inode, void *opaque)
315 {
316 	struct nfs_find_desc	*desc = opaque;
317 	struct nfs_fh		*fh = desc->fh;
318 	struct nfs_fattr	*fattr = desc->fattr;
319 
320 	if (NFS_FILEID(inode) != fattr->fileid)
321 		return 0;
322 	if (inode_wrong_type(inode, fattr->mode))
323 		return 0;
324 	if (nfs_compare_fh(NFS_FH(inode), fh))
325 		return 0;
326 	if (is_bad_inode(inode) || NFS_STALE(inode))
327 		return 0;
328 	return 1;
329 }
330 
331 static int
332 nfs_init_locked(struct inode *inode, void *opaque)
333 {
334 	struct nfs_find_desc	*desc = opaque;
335 	struct nfs_fattr	*fattr = desc->fattr;
336 
337 	set_nfs_fileid(inode, fattr->fileid);
338 	inode->i_mode = fattr->mode;
339 	nfs_copy_fh(NFS_FH(inode), desc->fh);
340 	return 0;
341 }
342 
343 #ifdef CONFIG_NFS_V4_SECURITY_LABEL
344 static void nfs_clear_label_invalid(struct inode *inode)
345 {
346 	spin_lock(&inode->i_lock);
347 	NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_LABEL;
348 	spin_unlock(&inode->i_lock);
349 }
350 
351 void nfs_setsecurity(struct inode *inode, struct nfs_fattr *fattr)
352 {
353 	int error;
354 
355 	if (fattr->label == NULL)
356 		return;
357 
358 	if ((fattr->valid & NFS_ATTR_FATTR_V4_SECURITY_LABEL) && inode->i_security) {
359 		error = security_inode_notifysecctx(inode, fattr->label->label,
360 				fattr->label->len);
361 		if (error)
362 			printk(KERN_ERR "%s() %s %d "
363 					"security_inode_notifysecctx() %d\n",
364 					__func__,
365 					(char *)fattr->label->label,
366 					fattr->label->len, error);
367 		nfs_clear_label_invalid(inode);
368 	}
369 }
370 
371 struct nfs4_label *nfs4_label_alloc(struct nfs_server *server, gfp_t flags)
372 {
373 	struct nfs4_label *label;
374 
375 	if (!(server->caps & NFS_CAP_SECURITY_LABEL))
376 		return NULL;
377 
378 	label = kzalloc(sizeof(struct nfs4_label), flags);
379 	if (label == NULL)
380 		return ERR_PTR(-ENOMEM);
381 
382 	label->label = kzalloc(NFS4_MAXLABELLEN, flags);
383 	if (label->label == NULL) {
384 		kfree(label);
385 		return ERR_PTR(-ENOMEM);
386 	}
387 	label->len = NFS4_MAXLABELLEN;
388 
389 	return label;
390 }
391 EXPORT_SYMBOL_GPL(nfs4_label_alloc);
392 #else
393 void nfs_setsecurity(struct inode *inode, struct nfs_fattr *fattr)
394 {
395 }
396 #endif
397 EXPORT_SYMBOL_GPL(nfs_setsecurity);
398 
399 /* Search for inode identified by fh, fileid and i_mode in inode cache. */
400 struct inode *
401 nfs_ilookup(struct super_block *sb, struct nfs_fattr *fattr, struct nfs_fh *fh)
402 {
403 	struct nfs_find_desc desc = {
404 		.fh	= fh,
405 		.fattr	= fattr,
406 	};
407 	struct inode *inode;
408 	unsigned long hash;
409 
410 	if (!(fattr->valid & NFS_ATTR_FATTR_FILEID) ||
411 	    !(fattr->valid & NFS_ATTR_FATTR_TYPE))
412 		return NULL;
413 
414 	hash = nfs_fattr_to_ino_t(fattr);
415 	inode = ilookup5(sb, hash, nfs_find_actor, &desc);
416 
417 	dprintk("%s: returning %p\n", __func__, inode);
418 	return inode;
419 }
420 
421 static void nfs_inode_init_regular(struct nfs_inode *nfsi)
422 {
423 	atomic_long_set(&nfsi->nrequests, 0);
424 	atomic_long_set(&nfsi->redirtied_pages, 0);
425 	INIT_LIST_HEAD(&nfsi->commit_info.list);
426 	atomic_long_set(&nfsi->commit_info.ncommit, 0);
427 	atomic_set(&nfsi->commit_info.rpcs_out, 0);
428 	mutex_init(&nfsi->commit_mutex);
429 }
430 
431 static void nfs_inode_init_dir(struct nfs_inode *nfsi)
432 {
433 	nfsi->cache_change_attribute = 0;
434 	memset(nfsi->cookieverf, 0, sizeof(nfsi->cookieverf));
435 	init_rwsem(&nfsi->rmdir_sem);
436 }
437 
438 /*
439  * This is our front-end to iget that looks up inodes by file handle
440  * instead of inode number.
441  */
442 struct inode *
443 nfs_fhget(struct super_block *sb, struct nfs_fh *fh, struct nfs_fattr *fattr)
444 {
445 	struct nfs_find_desc desc = {
446 		.fh	= fh,
447 		.fattr	= fattr
448 	};
449 	struct inode *inode = ERR_PTR(-ENOENT);
450 	u64 fattr_supported = NFS_SB(sb)->fattr_valid;
451 	unsigned long hash;
452 
453 	nfs_attr_check_mountpoint(sb, fattr);
454 
455 	if (nfs_attr_use_mounted_on_fileid(fattr))
456 		fattr->fileid = fattr->mounted_on_fileid;
457 	else if ((fattr->valid & NFS_ATTR_FATTR_FILEID) == 0)
458 		goto out_no_inode;
459 	if ((fattr->valid & NFS_ATTR_FATTR_TYPE) == 0)
460 		goto out_no_inode;
461 
462 	hash = nfs_fattr_to_ino_t(fattr);
463 
464 	inode = iget5_locked(sb, hash, nfs_find_actor, nfs_init_locked, &desc);
465 	if (inode == NULL) {
466 		inode = ERR_PTR(-ENOMEM);
467 		goto out_no_inode;
468 	}
469 
470 	if (inode->i_state & I_NEW) {
471 		struct nfs_inode *nfsi = NFS_I(inode);
472 		unsigned long now = jiffies;
473 
474 		/* We set i_ino for the few things that still rely on it,
475 		 * such as stat(2) */
476 		inode->i_ino = hash;
477 
478 		/* We can't support update_atime(), since the server will reset it */
479 		inode->i_flags |= S_NOATIME|S_NOCMTIME;
480 		inode->i_mode = fattr->mode;
481 		nfsi->cache_validity = 0;
482 		if ((fattr->valid & NFS_ATTR_FATTR_MODE) == 0
483 				&& (fattr_supported & NFS_ATTR_FATTR_MODE))
484 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_MODE);
485 		/* Why so? Because we want revalidate for devices/FIFOs, and
486 		 * that's precisely what we have in nfs_file_inode_operations.
487 		 */
488 		inode->i_op = NFS_SB(sb)->nfs_client->rpc_ops->file_inode_ops;
489 		if (S_ISREG(inode->i_mode)) {
490 			inode->i_fop = NFS_SB(sb)->nfs_client->rpc_ops->file_ops;
491 			inode->i_data.a_ops = &nfs_file_aops;
492 			nfs_inode_init_regular(nfsi);
493 		} else if (S_ISDIR(inode->i_mode)) {
494 			inode->i_op = NFS_SB(sb)->nfs_client->rpc_ops->dir_inode_ops;
495 			inode->i_fop = &nfs_dir_operations;
496 			inode->i_data.a_ops = &nfs_dir_aops;
497 			nfs_inode_init_dir(nfsi);
498 			/* Deal with crossing mountpoints */
499 			if (fattr->valid & NFS_ATTR_FATTR_MOUNTPOINT ||
500 					fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL) {
501 				if (fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL)
502 					inode->i_op = &nfs_referral_inode_operations;
503 				else
504 					inode->i_op = &nfs_mountpoint_inode_operations;
505 				inode->i_fop = NULL;
506 				inode->i_flags |= S_AUTOMOUNT;
507 			}
508 		} else if (S_ISLNK(inode->i_mode)) {
509 			inode->i_op = &nfs_symlink_inode_operations;
510 			inode_nohighmem(inode);
511 		} else
512 			init_special_inode(inode, inode->i_mode, fattr->rdev);
513 
514 		memset(&inode->i_atime, 0, sizeof(inode->i_atime));
515 		memset(&inode->i_mtime, 0, sizeof(inode->i_mtime));
516 		memset(&inode->i_ctime, 0, sizeof(inode->i_ctime));
517 		inode_set_iversion_raw(inode, 0);
518 		inode->i_size = 0;
519 		clear_nlink(inode);
520 		inode->i_uid = make_kuid(&init_user_ns, -2);
521 		inode->i_gid = make_kgid(&init_user_ns, -2);
522 		inode->i_blocks = 0;
523 		nfsi->write_io = 0;
524 		nfsi->read_io = 0;
525 
526 		nfsi->read_cache_jiffies = fattr->time_start;
527 		nfsi->attr_gencount = fattr->gencount;
528 		if (fattr->valid & NFS_ATTR_FATTR_ATIME)
529 			inode->i_atime = fattr->atime;
530 		else if (fattr_supported & NFS_ATTR_FATTR_ATIME)
531 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATIME);
532 		if (fattr->valid & NFS_ATTR_FATTR_MTIME)
533 			inode->i_mtime = fattr->mtime;
534 		else if (fattr_supported & NFS_ATTR_FATTR_MTIME)
535 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_MTIME);
536 		if (fattr->valid & NFS_ATTR_FATTR_CTIME)
537 			inode->i_ctime = fattr->ctime;
538 		else if (fattr_supported & NFS_ATTR_FATTR_CTIME)
539 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_CTIME);
540 		if (fattr->valid & NFS_ATTR_FATTR_CHANGE)
541 			inode_set_iversion_raw(inode, fattr->change_attr);
542 		else
543 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_CHANGE);
544 		if (fattr->valid & NFS_ATTR_FATTR_SIZE)
545 			inode->i_size = nfs_size_to_loff_t(fattr->size);
546 		else
547 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_SIZE);
548 		if (fattr->valid & NFS_ATTR_FATTR_NLINK)
549 			set_nlink(inode, fattr->nlink);
550 		else if (fattr_supported & NFS_ATTR_FATTR_NLINK)
551 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_NLINK);
552 		if (fattr->valid & NFS_ATTR_FATTR_OWNER)
553 			inode->i_uid = fattr->uid;
554 		else if (fattr_supported & NFS_ATTR_FATTR_OWNER)
555 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_OTHER);
556 		if (fattr->valid & NFS_ATTR_FATTR_GROUP)
557 			inode->i_gid = fattr->gid;
558 		else if (fattr_supported & NFS_ATTR_FATTR_GROUP)
559 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_OTHER);
560 		if (fattr->valid & NFS_ATTR_FATTR_BLOCKS_USED)
561 			inode->i_blocks = fattr->du.nfs2.blocks;
562 		else if (fattr_supported & NFS_ATTR_FATTR_BLOCKS_USED &&
563 			 fattr->size != 0)
564 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_BLOCKS);
565 		if (fattr->valid & NFS_ATTR_FATTR_SPACE_USED) {
566 			/*
567 			 * report the blocks in 512byte units
568 			 */
569 			inode->i_blocks = nfs_calc_block_size(fattr->du.nfs3.used);
570 		} else if (fattr_supported & NFS_ATTR_FATTR_SPACE_USED &&
571 			   fattr->size != 0)
572 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_BLOCKS);
573 
574 		nfs_setsecurity(inode, fattr);
575 
576 		nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
577 		nfsi->attrtimeo_timestamp = now;
578 		nfsi->access_cache = RB_ROOT;
579 
580 		nfs_fscache_init_inode(inode);
581 
582 		unlock_new_inode(inode);
583 	} else {
584 		int err = nfs_refresh_inode(inode, fattr);
585 		if (err < 0) {
586 			iput(inode);
587 			inode = ERR_PTR(err);
588 			goto out_no_inode;
589 		}
590 	}
591 	dprintk("NFS: nfs_fhget(%s/%Lu fh_crc=0x%08x ct=%d)\n",
592 		inode->i_sb->s_id,
593 		(unsigned long long)NFS_FILEID(inode),
594 		nfs_display_fhandle_hash(fh),
595 		atomic_read(&inode->i_count));
596 
597 out:
598 	return inode;
599 
600 out_no_inode:
601 	dprintk("nfs_fhget: iget failed with error %ld\n", PTR_ERR(inode));
602 	goto out;
603 }
604 EXPORT_SYMBOL_GPL(nfs_fhget);
605 
606 #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)
607 
608 int
609 nfs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
610 	    struct iattr *attr)
611 {
612 	struct inode *inode = d_inode(dentry);
613 	struct nfs_fattr *fattr;
614 	int error = 0;
615 
616 	nfs_inc_stats(inode, NFSIOS_VFSSETATTR);
617 
618 	/* skip mode change if it's just for clearing setuid/setgid */
619 	if (attr->ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
620 		attr->ia_valid &= ~ATTR_MODE;
621 
622 	if (attr->ia_valid & ATTR_SIZE) {
623 		BUG_ON(!S_ISREG(inode->i_mode));
624 
625 		error = inode_newsize_ok(inode, attr->ia_size);
626 		if (error)
627 			return error;
628 
629 		if (attr->ia_size == i_size_read(inode))
630 			attr->ia_valid &= ~ATTR_SIZE;
631 	}
632 
633 	/* Optimization: if the end result is no change, don't RPC */
634 	if (((attr->ia_valid & NFS_VALID_ATTRS) & ~(ATTR_FILE|ATTR_OPEN)) == 0)
635 		return 0;
636 
637 	trace_nfs_setattr_enter(inode);
638 
639 	/* Write all dirty data */
640 	if (S_ISREG(inode->i_mode))
641 		nfs_sync_inode(inode);
642 
643 	fattr = nfs_alloc_fattr_with_label(NFS_SERVER(inode));
644 	if (fattr == NULL) {
645 		error = -ENOMEM;
646 		goto out;
647 	}
648 
649 	error = NFS_PROTO(inode)->setattr(dentry, fattr, attr);
650 	if (error == 0)
651 		error = nfs_refresh_inode(inode, fattr);
652 	nfs_free_fattr(fattr);
653 out:
654 	trace_nfs_setattr_exit(inode, error);
655 	return error;
656 }
657 EXPORT_SYMBOL_GPL(nfs_setattr);
658 
659 /**
660  * nfs_vmtruncate - unmap mappings "freed" by truncate() syscall
661  * @inode: inode of the file used
662  * @offset: file offset to start truncating
663  *
664  * This is a copy of the common vmtruncate, but with the locking
665  * corrected to take into account the fact that NFS requires
666  * inode->i_size to be updated under the inode->i_lock.
667  * Note: must be called with inode->i_lock held!
668  */
669 static int nfs_vmtruncate(struct inode * inode, loff_t offset)
670 {
671 	int err;
672 
673 	err = inode_newsize_ok(inode, offset);
674 	if (err)
675 		goto out;
676 
677 	trace_nfs_size_truncate(inode, offset);
678 	i_size_write(inode, offset);
679 	/* Optimisation */
680 	if (offset == 0)
681 		NFS_I(inode)->cache_validity &= ~(NFS_INO_INVALID_DATA |
682 				NFS_INO_DATA_INVAL_DEFER);
683 	NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_SIZE;
684 
685 	spin_unlock(&inode->i_lock);
686 	truncate_pagecache(inode, offset);
687 	spin_lock(&inode->i_lock);
688 out:
689 	return err;
690 }
691 
692 /**
693  * nfs_setattr_update_inode - Update inode metadata after a setattr call.
694  * @inode: pointer to struct inode
695  * @attr: pointer to struct iattr
696  * @fattr: pointer to struct nfs_fattr
697  *
698  * Note: we do this in the *proc.c in order to ensure that
699  *       it works for things like exclusive creates too.
700  */
701 void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr,
702 		struct nfs_fattr *fattr)
703 {
704 	/* Barrier: bump the attribute generation count. */
705 	nfs_fattr_set_barrier(fattr);
706 
707 	spin_lock(&inode->i_lock);
708 	NFS_I(inode)->attr_gencount = fattr->gencount;
709 	if ((attr->ia_valid & ATTR_SIZE) != 0) {
710 		nfs_set_cache_invalid(inode, NFS_INO_INVALID_MTIME |
711 						     NFS_INO_INVALID_BLOCKS);
712 		nfs_inc_stats(inode, NFSIOS_SETATTRTRUNC);
713 		nfs_vmtruncate(inode, attr->ia_size);
714 	}
715 	if ((attr->ia_valid & (ATTR_MODE|ATTR_UID|ATTR_GID)) != 0) {
716 		NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_CTIME;
717 		if ((attr->ia_valid & ATTR_KILL_SUID) != 0 &&
718 		    inode->i_mode & S_ISUID)
719 			inode->i_mode &= ~S_ISUID;
720 		if ((attr->ia_valid & ATTR_KILL_SGID) != 0 &&
721 		    (inode->i_mode & (S_ISGID | S_IXGRP)) ==
722 		     (S_ISGID | S_IXGRP))
723 			inode->i_mode &= ~S_ISGID;
724 		if ((attr->ia_valid & ATTR_MODE) != 0) {
725 			int mode = attr->ia_mode & S_IALLUGO;
726 			mode |= inode->i_mode & ~S_IALLUGO;
727 			inode->i_mode = mode;
728 		}
729 		if ((attr->ia_valid & ATTR_UID) != 0)
730 			inode->i_uid = attr->ia_uid;
731 		if ((attr->ia_valid & ATTR_GID) != 0)
732 			inode->i_gid = attr->ia_gid;
733 		if (fattr->valid & NFS_ATTR_FATTR_CTIME)
734 			inode->i_ctime = fattr->ctime;
735 		else
736 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_CHANGE
737 					| NFS_INO_INVALID_CTIME);
738 		nfs_set_cache_invalid(inode, NFS_INO_INVALID_ACCESS
739 				| NFS_INO_INVALID_ACL);
740 	}
741 	if (attr->ia_valid & (ATTR_ATIME_SET|ATTR_ATIME)) {
742 		NFS_I(inode)->cache_validity &= ~(NFS_INO_INVALID_ATIME
743 				| NFS_INO_INVALID_CTIME);
744 		if (fattr->valid & NFS_ATTR_FATTR_ATIME)
745 			inode->i_atime = fattr->atime;
746 		else if (attr->ia_valid & ATTR_ATIME_SET)
747 			inode->i_atime = attr->ia_atime;
748 		else
749 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATIME);
750 
751 		if (fattr->valid & NFS_ATTR_FATTR_CTIME)
752 			inode->i_ctime = fattr->ctime;
753 		else
754 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_CHANGE
755 					| NFS_INO_INVALID_CTIME);
756 	}
757 	if (attr->ia_valid & (ATTR_MTIME_SET|ATTR_MTIME)) {
758 		NFS_I(inode)->cache_validity &= ~(NFS_INO_INVALID_MTIME
759 				| NFS_INO_INVALID_CTIME);
760 		if (fattr->valid & NFS_ATTR_FATTR_MTIME)
761 			inode->i_mtime = fattr->mtime;
762 		else if (attr->ia_valid & ATTR_MTIME_SET)
763 			inode->i_mtime = attr->ia_mtime;
764 		else
765 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_MTIME);
766 
767 		if (fattr->valid & NFS_ATTR_FATTR_CTIME)
768 			inode->i_ctime = fattr->ctime;
769 		else
770 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_CHANGE
771 					| NFS_INO_INVALID_CTIME);
772 	}
773 	if (fattr->valid)
774 		nfs_update_inode(inode, fattr);
775 	spin_unlock(&inode->i_lock);
776 }
777 EXPORT_SYMBOL_GPL(nfs_setattr_update_inode);
778 
779 /*
780  * Don't request help from readdirplus if the file is being written to,
781  * or if attribute caching is turned off
782  */
783 static bool nfs_getattr_readdirplus_enable(const struct inode *inode)
784 {
785 	return nfs_server_capable(inode, NFS_CAP_READDIRPLUS) &&
786 	       !nfs_have_writebacks(inode) && NFS_MAXATTRTIMEO(inode) > 5 * HZ;
787 }
788 
789 static void nfs_readdirplus_parent_cache_miss(struct dentry *dentry)
790 {
791 	if (!IS_ROOT(dentry)) {
792 		struct dentry *parent = dget_parent(dentry);
793 		nfs_readdir_record_entry_cache_miss(d_inode(parent));
794 		dput(parent);
795 	}
796 }
797 
798 static void nfs_readdirplus_parent_cache_hit(struct dentry *dentry)
799 {
800 	if (!IS_ROOT(dentry)) {
801 		struct dentry *parent = dget_parent(dentry);
802 		nfs_readdir_record_entry_cache_hit(d_inode(parent));
803 		dput(parent);
804 	}
805 }
806 
807 static u32 nfs_get_valid_attrmask(struct inode *inode)
808 {
809 	unsigned long cache_validity = READ_ONCE(NFS_I(inode)->cache_validity);
810 	u32 reply_mask = STATX_INO | STATX_TYPE;
811 
812 	if (!(cache_validity & NFS_INO_INVALID_ATIME))
813 		reply_mask |= STATX_ATIME;
814 	if (!(cache_validity & NFS_INO_INVALID_CTIME))
815 		reply_mask |= STATX_CTIME;
816 	if (!(cache_validity & NFS_INO_INVALID_MTIME))
817 		reply_mask |= STATX_MTIME;
818 	if (!(cache_validity & NFS_INO_INVALID_SIZE))
819 		reply_mask |= STATX_SIZE;
820 	if (!(cache_validity & NFS_INO_INVALID_NLINK))
821 		reply_mask |= STATX_NLINK;
822 	if (!(cache_validity & NFS_INO_INVALID_MODE))
823 		reply_mask |= STATX_MODE;
824 	if (!(cache_validity & NFS_INO_INVALID_OTHER))
825 		reply_mask |= STATX_UID | STATX_GID;
826 	if (!(cache_validity & NFS_INO_INVALID_BLOCKS))
827 		reply_mask |= STATX_BLOCKS;
828 	return reply_mask;
829 }
830 
831 int nfs_getattr(struct user_namespace *mnt_userns, const struct path *path,
832 		struct kstat *stat, u32 request_mask, unsigned int query_flags)
833 {
834 	struct inode *inode = d_inode(path->dentry);
835 	struct nfs_server *server = NFS_SERVER(inode);
836 	unsigned long cache_validity;
837 	int err = 0;
838 	bool force_sync = query_flags & AT_STATX_FORCE_SYNC;
839 	bool do_update = false;
840 	bool readdirplus_enabled = nfs_getattr_readdirplus_enable(inode);
841 
842 	trace_nfs_getattr_enter(inode);
843 
844 	request_mask &= STATX_TYPE | STATX_MODE | STATX_NLINK | STATX_UID |
845 			STATX_GID | STATX_ATIME | STATX_MTIME | STATX_CTIME |
846 			STATX_INO | STATX_SIZE | STATX_BLOCKS;
847 
848 	if ((query_flags & AT_STATX_DONT_SYNC) && !force_sync) {
849 		if (readdirplus_enabled)
850 			nfs_readdirplus_parent_cache_hit(path->dentry);
851 		goto out_no_revalidate;
852 	}
853 
854 	/* Flush out writes to the server in order to update c/mtime.  */
855 	if ((request_mask & (STATX_CTIME | STATX_MTIME)) &&
856 	    S_ISREG(inode->i_mode))
857 		filemap_write_and_wait(inode->i_mapping);
858 
859 	/*
860 	 * We may force a getattr if the user cares about atime.
861 	 *
862 	 * Note that we only have to check the vfsmount flags here:
863 	 *  - NFS always sets S_NOATIME by so checking it would give a
864 	 *    bogus result
865 	 *  - NFS never sets SB_NOATIME or SB_NODIRATIME so there is
866 	 *    no point in checking those.
867 	 */
868 	if ((path->mnt->mnt_flags & MNT_NOATIME) ||
869 	    ((path->mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode)))
870 		request_mask &= ~STATX_ATIME;
871 
872 	/* Is the user requesting attributes that might need revalidation? */
873 	if (!(request_mask & (STATX_MODE|STATX_NLINK|STATX_ATIME|STATX_CTIME|
874 					STATX_MTIME|STATX_UID|STATX_GID|
875 					STATX_SIZE|STATX_BLOCKS)))
876 		goto out_no_revalidate;
877 
878 	/* Check whether the cached attributes are stale */
879 	do_update |= force_sync || nfs_attribute_cache_expired(inode);
880 	cache_validity = READ_ONCE(NFS_I(inode)->cache_validity);
881 	do_update |= cache_validity & NFS_INO_INVALID_CHANGE;
882 	if (request_mask & STATX_ATIME)
883 		do_update |= cache_validity & NFS_INO_INVALID_ATIME;
884 	if (request_mask & STATX_CTIME)
885 		do_update |= cache_validity & NFS_INO_INVALID_CTIME;
886 	if (request_mask & STATX_MTIME)
887 		do_update |= cache_validity & NFS_INO_INVALID_MTIME;
888 	if (request_mask & STATX_SIZE)
889 		do_update |= cache_validity & NFS_INO_INVALID_SIZE;
890 	if (request_mask & STATX_NLINK)
891 		do_update |= cache_validity & NFS_INO_INVALID_NLINK;
892 	if (request_mask & STATX_MODE)
893 		do_update |= cache_validity & NFS_INO_INVALID_MODE;
894 	if (request_mask & (STATX_UID | STATX_GID))
895 		do_update |= cache_validity & NFS_INO_INVALID_OTHER;
896 	if (request_mask & STATX_BLOCKS)
897 		do_update |= cache_validity & NFS_INO_INVALID_BLOCKS;
898 
899 	if (do_update) {
900 		if (readdirplus_enabled)
901 			nfs_readdirplus_parent_cache_miss(path->dentry);
902 		err = __nfs_revalidate_inode(server, inode);
903 		if (err)
904 			goto out;
905 	} else if (readdirplus_enabled)
906 		nfs_readdirplus_parent_cache_hit(path->dentry);
907 out_no_revalidate:
908 	/* Only return attributes that were revalidated. */
909 	stat->result_mask = nfs_get_valid_attrmask(inode) | request_mask;
910 
911 	generic_fillattr(&init_user_ns, inode, stat);
912 	stat->ino = nfs_compat_user_ino64(NFS_FILEID(inode));
913 	if (S_ISDIR(inode->i_mode))
914 		stat->blksize = NFS_SERVER(inode)->dtsize;
915 out:
916 	trace_nfs_getattr_exit(inode, err);
917 	return err;
918 }
919 EXPORT_SYMBOL_GPL(nfs_getattr);
920 
921 static void nfs_init_lock_context(struct nfs_lock_context *l_ctx)
922 {
923 	refcount_set(&l_ctx->count, 1);
924 	l_ctx->lockowner = current->files;
925 	INIT_LIST_HEAD(&l_ctx->list);
926 	atomic_set(&l_ctx->io_count, 0);
927 }
928 
929 static struct nfs_lock_context *__nfs_find_lock_context(struct nfs_open_context *ctx)
930 {
931 	struct nfs_lock_context *pos;
932 
933 	list_for_each_entry_rcu(pos, &ctx->lock_context.list, list) {
934 		if (pos->lockowner != current->files)
935 			continue;
936 		if (refcount_inc_not_zero(&pos->count))
937 			return pos;
938 	}
939 	return NULL;
940 }
941 
942 struct nfs_lock_context *nfs_get_lock_context(struct nfs_open_context *ctx)
943 {
944 	struct nfs_lock_context *res, *new = NULL;
945 	struct inode *inode = d_inode(ctx->dentry);
946 
947 	rcu_read_lock();
948 	res = __nfs_find_lock_context(ctx);
949 	rcu_read_unlock();
950 	if (res == NULL) {
951 		new = kmalloc(sizeof(*new), GFP_KERNEL_ACCOUNT);
952 		if (new == NULL)
953 			return ERR_PTR(-ENOMEM);
954 		nfs_init_lock_context(new);
955 		spin_lock(&inode->i_lock);
956 		res = __nfs_find_lock_context(ctx);
957 		if (res == NULL) {
958 			new->open_context = get_nfs_open_context(ctx);
959 			if (new->open_context) {
960 				list_add_tail_rcu(&new->list,
961 						&ctx->lock_context.list);
962 				res = new;
963 				new = NULL;
964 			} else
965 				res = ERR_PTR(-EBADF);
966 		}
967 		spin_unlock(&inode->i_lock);
968 		kfree(new);
969 	}
970 	return res;
971 }
972 EXPORT_SYMBOL_GPL(nfs_get_lock_context);
973 
974 void nfs_put_lock_context(struct nfs_lock_context *l_ctx)
975 {
976 	struct nfs_open_context *ctx = l_ctx->open_context;
977 	struct inode *inode = d_inode(ctx->dentry);
978 
979 	if (!refcount_dec_and_lock(&l_ctx->count, &inode->i_lock))
980 		return;
981 	list_del_rcu(&l_ctx->list);
982 	spin_unlock(&inode->i_lock);
983 	put_nfs_open_context(ctx);
984 	kfree_rcu(l_ctx, rcu_head);
985 }
986 EXPORT_SYMBOL_GPL(nfs_put_lock_context);
987 
988 /**
989  * nfs_close_context - Common close_context() routine NFSv2/v3
990  * @ctx: pointer to context
991  * @is_sync: is this a synchronous close
992  *
993  * Ensure that the attributes are up to date if we're mounted
994  * with close-to-open semantics and we have cached data that will
995  * need to be revalidated on open.
996  */
997 void nfs_close_context(struct nfs_open_context *ctx, int is_sync)
998 {
999 	struct nfs_inode *nfsi;
1000 	struct inode *inode;
1001 
1002 	if (!(ctx->mode & FMODE_WRITE))
1003 		return;
1004 	if (!is_sync)
1005 		return;
1006 	inode = d_inode(ctx->dentry);
1007 	if (NFS_PROTO(inode)->have_delegation(inode, FMODE_READ))
1008 		return;
1009 	nfsi = NFS_I(inode);
1010 	if (inode->i_mapping->nrpages == 0)
1011 		return;
1012 	if (nfsi->cache_validity & NFS_INO_INVALID_DATA)
1013 		return;
1014 	if (!list_empty(&nfsi->open_files))
1015 		return;
1016 	if (NFS_SERVER(inode)->flags & NFS_MOUNT_NOCTO)
1017 		return;
1018 	nfs_revalidate_inode(inode,
1019 			     NFS_INO_INVALID_CHANGE | NFS_INO_INVALID_SIZE);
1020 }
1021 EXPORT_SYMBOL_GPL(nfs_close_context);
1022 
1023 struct nfs_open_context *alloc_nfs_open_context(struct dentry *dentry,
1024 						fmode_t f_mode,
1025 						struct file *filp)
1026 {
1027 	struct nfs_open_context *ctx;
1028 
1029 	ctx = kmalloc(sizeof(*ctx), GFP_KERNEL_ACCOUNT);
1030 	if (!ctx)
1031 		return ERR_PTR(-ENOMEM);
1032 	nfs_sb_active(dentry->d_sb);
1033 	ctx->dentry = dget(dentry);
1034 	if (filp)
1035 		ctx->cred = get_cred(filp->f_cred);
1036 	else
1037 		ctx->cred = get_current_cred();
1038 	rcu_assign_pointer(ctx->ll_cred, NULL);
1039 	ctx->state = NULL;
1040 	ctx->mode = f_mode;
1041 	ctx->flags = 0;
1042 	ctx->error = 0;
1043 	ctx->flock_owner = (fl_owner_t)filp;
1044 	nfs_init_lock_context(&ctx->lock_context);
1045 	ctx->lock_context.open_context = ctx;
1046 	INIT_LIST_HEAD(&ctx->list);
1047 	ctx->mdsthreshold = NULL;
1048 	return ctx;
1049 }
1050 EXPORT_SYMBOL_GPL(alloc_nfs_open_context);
1051 
1052 struct nfs_open_context *get_nfs_open_context(struct nfs_open_context *ctx)
1053 {
1054 	if (ctx != NULL && refcount_inc_not_zero(&ctx->lock_context.count))
1055 		return ctx;
1056 	return NULL;
1057 }
1058 EXPORT_SYMBOL_GPL(get_nfs_open_context);
1059 
1060 static void __put_nfs_open_context(struct nfs_open_context *ctx, int is_sync)
1061 {
1062 	struct inode *inode = d_inode(ctx->dentry);
1063 	struct super_block *sb = ctx->dentry->d_sb;
1064 
1065 	if (!refcount_dec_and_test(&ctx->lock_context.count))
1066 		return;
1067 	if (!list_empty(&ctx->list)) {
1068 		spin_lock(&inode->i_lock);
1069 		list_del_rcu(&ctx->list);
1070 		spin_unlock(&inode->i_lock);
1071 	}
1072 	if (inode != NULL)
1073 		NFS_PROTO(inode)->close_context(ctx, is_sync);
1074 	put_cred(ctx->cred);
1075 	dput(ctx->dentry);
1076 	nfs_sb_deactive(sb);
1077 	put_rpccred(rcu_dereference_protected(ctx->ll_cred, 1));
1078 	kfree(ctx->mdsthreshold);
1079 	kfree_rcu(ctx, rcu_head);
1080 }
1081 
1082 void put_nfs_open_context(struct nfs_open_context *ctx)
1083 {
1084 	__put_nfs_open_context(ctx, 0);
1085 }
1086 EXPORT_SYMBOL_GPL(put_nfs_open_context);
1087 
1088 static void put_nfs_open_context_sync(struct nfs_open_context *ctx)
1089 {
1090 	__put_nfs_open_context(ctx, 1);
1091 }
1092 
1093 /*
1094  * Ensure that mmap has a recent RPC credential for use when writing out
1095  * shared pages
1096  */
1097 void nfs_inode_attach_open_context(struct nfs_open_context *ctx)
1098 {
1099 	struct inode *inode = d_inode(ctx->dentry);
1100 	struct nfs_inode *nfsi = NFS_I(inode);
1101 
1102 	spin_lock(&inode->i_lock);
1103 	if (list_empty(&nfsi->open_files) &&
1104 	    (nfsi->cache_validity & NFS_INO_DATA_INVAL_DEFER))
1105 		nfs_set_cache_invalid(inode, NFS_INO_INVALID_DATA |
1106 						     NFS_INO_REVAL_FORCED);
1107 	list_add_tail_rcu(&ctx->list, &nfsi->open_files);
1108 	spin_unlock(&inode->i_lock);
1109 }
1110 EXPORT_SYMBOL_GPL(nfs_inode_attach_open_context);
1111 
1112 void nfs_file_set_open_context(struct file *filp, struct nfs_open_context *ctx)
1113 {
1114 	filp->private_data = get_nfs_open_context(ctx);
1115 	set_bit(NFS_CONTEXT_FILE_OPEN, &ctx->flags);
1116 	if (list_empty(&ctx->list))
1117 		nfs_inode_attach_open_context(ctx);
1118 }
1119 EXPORT_SYMBOL_GPL(nfs_file_set_open_context);
1120 
1121 /*
1122  * Given an inode, search for an open context with the desired characteristics
1123  */
1124 struct nfs_open_context *nfs_find_open_context(struct inode *inode, const struct cred *cred, fmode_t mode)
1125 {
1126 	struct nfs_inode *nfsi = NFS_I(inode);
1127 	struct nfs_open_context *pos, *ctx = NULL;
1128 
1129 	rcu_read_lock();
1130 	list_for_each_entry_rcu(pos, &nfsi->open_files, list) {
1131 		if (cred != NULL && cred_fscmp(pos->cred, cred) != 0)
1132 			continue;
1133 		if ((pos->mode & (FMODE_READ|FMODE_WRITE)) != mode)
1134 			continue;
1135 		if (!test_bit(NFS_CONTEXT_FILE_OPEN, &pos->flags))
1136 			continue;
1137 		ctx = get_nfs_open_context(pos);
1138 		if (ctx)
1139 			break;
1140 	}
1141 	rcu_read_unlock();
1142 	return ctx;
1143 }
1144 
1145 void nfs_file_clear_open_context(struct file *filp)
1146 {
1147 	struct nfs_open_context *ctx = nfs_file_open_context(filp);
1148 
1149 	if (ctx) {
1150 		struct inode *inode = d_inode(ctx->dentry);
1151 
1152 		clear_bit(NFS_CONTEXT_FILE_OPEN, &ctx->flags);
1153 		/*
1154 		 * We fatal error on write before. Try to writeback
1155 		 * every page again.
1156 		 */
1157 		if (ctx->error < 0)
1158 			invalidate_inode_pages2(inode->i_mapping);
1159 		filp->private_data = NULL;
1160 		put_nfs_open_context_sync(ctx);
1161 	}
1162 }
1163 
1164 /*
1165  * These allocate and release file read/write context information.
1166  */
1167 int nfs_open(struct inode *inode, struct file *filp)
1168 {
1169 	struct nfs_open_context *ctx;
1170 
1171 	ctx = alloc_nfs_open_context(file_dentry(filp),
1172 				     flags_to_mode(filp->f_flags), filp);
1173 	if (IS_ERR(ctx))
1174 		return PTR_ERR(ctx);
1175 	nfs_file_set_open_context(filp, ctx);
1176 	put_nfs_open_context(ctx);
1177 	nfs_fscache_open_file(inode, filp);
1178 	return 0;
1179 }
1180 
1181 /*
1182  * This function is called whenever some part of NFS notices that
1183  * the cached attributes have to be refreshed.
1184  */
1185 int
1186 __nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
1187 {
1188 	int		 status = -ESTALE;
1189 	struct nfs_fattr *fattr = NULL;
1190 	struct nfs_inode *nfsi = NFS_I(inode);
1191 
1192 	dfprintk(PAGECACHE, "NFS: revalidating (%s/%Lu)\n",
1193 		inode->i_sb->s_id, (unsigned long long)NFS_FILEID(inode));
1194 
1195 	trace_nfs_revalidate_inode_enter(inode);
1196 
1197 	if (is_bad_inode(inode))
1198 		goto out;
1199 	if (NFS_STALE(inode))
1200 		goto out;
1201 
1202 	/* pNFS: Attributes aren't updated until we layoutcommit */
1203 	if (S_ISREG(inode->i_mode)) {
1204 		status = pnfs_sync_inode(inode, false);
1205 		if (status)
1206 			goto out;
1207 	}
1208 
1209 	status = -ENOMEM;
1210 	fattr = nfs_alloc_fattr_with_label(NFS_SERVER(inode));
1211 	if (fattr == NULL)
1212 		goto out;
1213 
1214 	nfs_inc_stats(inode, NFSIOS_INODEREVALIDATE);
1215 
1216 	status = NFS_PROTO(inode)->getattr(server, NFS_FH(inode), fattr, inode);
1217 	if (status != 0) {
1218 		dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Lu) getattr failed, error=%d\n",
1219 			 inode->i_sb->s_id,
1220 			 (unsigned long long)NFS_FILEID(inode), status);
1221 		switch (status) {
1222 		case -ETIMEDOUT:
1223 			/* A soft timeout occurred. Use cached information? */
1224 			if (server->flags & NFS_MOUNT_SOFTREVAL)
1225 				status = 0;
1226 			break;
1227 		case -ESTALE:
1228 			if (!S_ISDIR(inode->i_mode))
1229 				nfs_set_inode_stale(inode);
1230 			else
1231 				nfs_zap_caches(inode);
1232 		}
1233 		goto out;
1234 	}
1235 
1236 	status = nfs_refresh_inode(inode, fattr);
1237 	if (status) {
1238 		dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Lu) refresh failed, error=%d\n",
1239 			 inode->i_sb->s_id,
1240 			 (unsigned long long)NFS_FILEID(inode), status);
1241 		goto out;
1242 	}
1243 
1244 	if (nfsi->cache_validity & NFS_INO_INVALID_ACL)
1245 		nfs_zap_acl_cache(inode);
1246 
1247 	nfs_setsecurity(inode, fattr);
1248 
1249 	dfprintk(PAGECACHE, "NFS: (%s/%Lu) revalidation complete\n",
1250 		inode->i_sb->s_id,
1251 		(unsigned long long)NFS_FILEID(inode));
1252 
1253 out:
1254 	nfs_free_fattr(fattr);
1255 	trace_nfs_revalidate_inode_exit(inode, status);
1256 	return status;
1257 }
1258 
1259 int nfs_attribute_cache_expired(struct inode *inode)
1260 {
1261 	if (nfs_have_delegated_attributes(inode))
1262 		return 0;
1263 	return nfs_attribute_timeout(inode);
1264 }
1265 
1266 /**
1267  * nfs_revalidate_inode - Revalidate the inode attributes
1268  * @inode: pointer to inode struct
1269  * @flags: cache flags to check
1270  *
1271  * Updates inode attribute information by retrieving the data from the server.
1272  */
1273 int nfs_revalidate_inode(struct inode *inode, unsigned long flags)
1274 {
1275 	if (!nfs_check_cache_invalid(inode, flags))
1276 		return NFS_STALE(inode) ? -ESTALE : 0;
1277 	return __nfs_revalidate_inode(NFS_SERVER(inode), inode);
1278 }
1279 EXPORT_SYMBOL_GPL(nfs_revalidate_inode);
1280 
1281 static int nfs_invalidate_mapping(struct inode *inode, struct address_space *mapping)
1282 {
1283 	int ret;
1284 
1285 	nfs_fscache_invalidate(inode, 0);
1286 	if (mapping->nrpages != 0) {
1287 		if (S_ISREG(inode->i_mode)) {
1288 			ret = nfs_sync_mapping(mapping);
1289 			if (ret < 0)
1290 				return ret;
1291 		}
1292 		ret = invalidate_inode_pages2(mapping);
1293 		if (ret < 0)
1294 			return ret;
1295 	}
1296 	nfs_inc_stats(inode, NFSIOS_DATAINVALIDATE);
1297 
1298 	dfprintk(PAGECACHE, "NFS: (%s/%Lu) data cache invalidated\n",
1299 			inode->i_sb->s_id,
1300 			(unsigned long long)NFS_FILEID(inode));
1301 	return 0;
1302 }
1303 
1304 /**
1305  * nfs_clear_invalid_mapping - Conditionally clear a mapping
1306  * @mapping: pointer to mapping
1307  *
1308  * If the NFS_INO_INVALID_DATA inode flag is set, clear the mapping.
1309  */
1310 int nfs_clear_invalid_mapping(struct address_space *mapping)
1311 {
1312 	struct inode *inode = mapping->host;
1313 	struct nfs_inode *nfsi = NFS_I(inode);
1314 	unsigned long *bitlock = &nfsi->flags;
1315 	int ret = 0;
1316 
1317 	/*
1318 	 * We must clear NFS_INO_INVALID_DATA first to ensure that
1319 	 * invalidations that come in while we're shooting down the mappings
1320 	 * are respected. But, that leaves a race window where one revalidator
1321 	 * can clear the flag, and then another checks it before the mapping
1322 	 * gets invalidated. Fix that by serializing access to this part of
1323 	 * the function.
1324 	 *
1325 	 * At the same time, we need to allow other tasks to see whether we
1326 	 * might be in the middle of invalidating the pages, so we only set
1327 	 * the bit lock here if it looks like we're going to be doing that.
1328 	 */
1329 	for (;;) {
1330 		ret = wait_on_bit_action(bitlock, NFS_INO_INVALIDATING,
1331 					 nfs_wait_bit_killable,
1332 					 TASK_KILLABLE|TASK_FREEZABLE_UNSAFE);
1333 		if (ret)
1334 			goto out;
1335 		spin_lock(&inode->i_lock);
1336 		if (test_bit(NFS_INO_INVALIDATING, bitlock)) {
1337 			spin_unlock(&inode->i_lock);
1338 			continue;
1339 		}
1340 		if (nfsi->cache_validity & NFS_INO_INVALID_DATA)
1341 			break;
1342 		spin_unlock(&inode->i_lock);
1343 		goto out;
1344 	}
1345 
1346 	set_bit(NFS_INO_INVALIDATING, bitlock);
1347 	smp_wmb();
1348 	nfsi->cache_validity &=
1349 		~(NFS_INO_INVALID_DATA | NFS_INO_DATA_INVAL_DEFER);
1350 	spin_unlock(&inode->i_lock);
1351 	trace_nfs_invalidate_mapping_enter(inode);
1352 	ret = nfs_invalidate_mapping(inode, mapping);
1353 	trace_nfs_invalidate_mapping_exit(inode, ret);
1354 
1355 	clear_bit_unlock(NFS_INO_INVALIDATING, bitlock);
1356 	smp_mb__after_atomic();
1357 	wake_up_bit(bitlock, NFS_INO_INVALIDATING);
1358 out:
1359 	return ret;
1360 }
1361 
1362 bool nfs_mapping_need_revalidate_inode(struct inode *inode)
1363 {
1364 	return nfs_check_cache_invalid(inode, NFS_INO_INVALID_CHANGE) ||
1365 		NFS_STALE(inode);
1366 }
1367 
1368 int nfs_revalidate_mapping_rcu(struct inode *inode)
1369 {
1370 	struct nfs_inode *nfsi = NFS_I(inode);
1371 	unsigned long *bitlock = &nfsi->flags;
1372 	int ret = 0;
1373 
1374 	if (IS_SWAPFILE(inode))
1375 		goto out;
1376 	if (nfs_mapping_need_revalidate_inode(inode)) {
1377 		ret = -ECHILD;
1378 		goto out;
1379 	}
1380 	spin_lock(&inode->i_lock);
1381 	if (test_bit(NFS_INO_INVALIDATING, bitlock) ||
1382 	    (nfsi->cache_validity & NFS_INO_INVALID_DATA))
1383 		ret = -ECHILD;
1384 	spin_unlock(&inode->i_lock);
1385 out:
1386 	return ret;
1387 }
1388 
1389 /**
1390  * nfs_revalidate_mapping - Revalidate the pagecache
1391  * @inode: pointer to host inode
1392  * @mapping: pointer to mapping
1393  */
1394 int nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping)
1395 {
1396 	/* swapfiles are not supposed to be shared. */
1397 	if (IS_SWAPFILE(inode))
1398 		return 0;
1399 
1400 	if (nfs_mapping_need_revalidate_inode(inode)) {
1401 		int ret = __nfs_revalidate_inode(NFS_SERVER(inode), inode);
1402 		if (ret < 0)
1403 			return ret;
1404 	}
1405 
1406 	return nfs_clear_invalid_mapping(mapping);
1407 }
1408 
1409 static bool nfs_file_has_writers(struct nfs_inode *nfsi)
1410 {
1411 	struct inode *inode = &nfsi->vfs_inode;
1412 
1413 	if (!S_ISREG(inode->i_mode))
1414 		return false;
1415 	if (list_empty(&nfsi->open_files))
1416 		return false;
1417 	return inode_is_open_for_write(inode);
1418 }
1419 
1420 static bool nfs_file_has_buffered_writers(struct nfs_inode *nfsi)
1421 {
1422 	return nfs_file_has_writers(nfsi) && nfs_file_io_is_buffered(nfsi);
1423 }
1424 
1425 static void nfs_wcc_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1426 {
1427 	struct timespec64 ts;
1428 
1429 	if ((fattr->valid & NFS_ATTR_FATTR_PRECHANGE)
1430 			&& (fattr->valid & NFS_ATTR_FATTR_CHANGE)
1431 			&& inode_eq_iversion_raw(inode, fattr->pre_change_attr)) {
1432 		inode_set_iversion_raw(inode, fattr->change_attr);
1433 		if (S_ISDIR(inode->i_mode))
1434 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_DATA);
1435 		else if (nfs_server_capable(inode, NFS_CAP_XATTR))
1436 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_XATTR);
1437 	}
1438 	/* If we have atomic WCC data, we may update some attributes */
1439 	ts = inode->i_ctime;
1440 	if ((fattr->valid & NFS_ATTR_FATTR_PRECTIME)
1441 			&& (fattr->valid & NFS_ATTR_FATTR_CTIME)
1442 			&& timespec64_equal(&ts, &fattr->pre_ctime)) {
1443 		inode->i_ctime = fattr->ctime;
1444 	}
1445 
1446 	ts = inode->i_mtime;
1447 	if ((fattr->valid & NFS_ATTR_FATTR_PREMTIME)
1448 			&& (fattr->valid & NFS_ATTR_FATTR_MTIME)
1449 			&& timespec64_equal(&ts, &fattr->pre_mtime)) {
1450 		inode->i_mtime = fattr->mtime;
1451 	}
1452 	if ((fattr->valid & NFS_ATTR_FATTR_PRESIZE)
1453 			&& (fattr->valid & NFS_ATTR_FATTR_SIZE)
1454 			&& i_size_read(inode) == nfs_size_to_loff_t(fattr->pre_size)
1455 			&& !nfs_have_writebacks(inode)) {
1456 		trace_nfs_size_wcc(inode, fattr->size);
1457 		i_size_write(inode, nfs_size_to_loff_t(fattr->size));
1458 	}
1459 }
1460 
1461 /**
1462  * nfs_check_inode_attributes - verify consistency of the inode attribute cache
1463  * @inode: pointer to inode
1464  * @fattr: updated attributes
1465  *
1466  * Verifies the attribute cache. If we have just changed the attributes,
1467  * so that fattr carries weak cache consistency data, then it may
1468  * also update the ctime/mtime/change_attribute.
1469  */
1470 static int nfs_check_inode_attributes(struct inode *inode, struct nfs_fattr *fattr)
1471 {
1472 	struct nfs_inode *nfsi = NFS_I(inode);
1473 	loff_t cur_size, new_isize;
1474 	unsigned long invalid = 0;
1475 	struct timespec64 ts;
1476 
1477 	if (NFS_PROTO(inode)->have_delegation(inode, FMODE_READ))
1478 		return 0;
1479 
1480 	if (!(fattr->valid & NFS_ATTR_FATTR_FILEID)) {
1481 		/* Only a mounted-on-fileid? Just exit */
1482 		if (fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID)
1483 			return 0;
1484 	/* Has the inode gone and changed behind our back? */
1485 	} else if (nfsi->fileid != fattr->fileid) {
1486 		/* Is this perhaps the mounted-on fileid? */
1487 		if ((fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID) &&
1488 		    nfsi->fileid == fattr->mounted_on_fileid)
1489 			return 0;
1490 		return -ESTALE;
1491 	}
1492 	if ((fattr->valid & NFS_ATTR_FATTR_TYPE) && inode_wrong_type(inode, fattr->mode))
1493 		return -ESTALE;
1494 
1495 
1496 	if (!nfs_file_has_buffered_writers(nfsi)) {
1497 		/* Verify a few of the more important attributes */
1498 		if ((fattr->valid & NFS_ATTR_FATTR_CHANGE) != 0 && !inode_eq_iversion_raw(inode, fattr->change_attr))
1499 			invalid |= NFS_INO_INVALID_CHANGE;
1500 
1501 		ts = inode->i_mtime;
1502 		if ((fattr->valid & NFS_ATTR_FATTR_MTIME) && !timespec64_equal(&ts, &fattr->mtime))
1503 			invalid |= NFS_INO_INVALID_MTIME;
1504 
1505 		ts = inode->i_ctime;
1506 		if ((fattr->valid & NFS_ATTR_FATTR_CTIME) && !timespec64_equal(&ts, &fattr->ctime))
1507 			invalid |= NFS_INO_INVALID_CTIME;
1508 
1509 		if (fattr->valid & NFS_ATTR_FATTR_SIZE) {
1510 			cur_size = i_size_read(inode);
1511 			new_isize = nfs_size_to_loff_t(fattr->size);
1512 			if (cur_size != new_isize)
1513 				invalid |= NFS_INO_INVALID_SIZE;
1514 		}
1515 	}
1516 
1517 	/* Have any file permissions changed? */
1518 	if ((fattr->valid & NFS_ATTR_FATTR_MODE) && (inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO))
1519 		invalid |= NFS_INO_INVALID_MODE;
1520 	if ((fattr->valid & NFS_ATTR_FATTR_OWNER) && !uid_eq(inode->i_uid, fattr->uid))
1521 		invalid |= NFS_INO_INVALID_OTHER;
1522 	if ((fattr->valid & NFS_ATTR_FATTR_GROUP) && !gid_eq(inode->i_gid, fattr->gid))
1523 		invalid |= NFS_INO_INVALID_OTHER;
1524 
1525 	/* Has the link count changed? */
1526 	if ((fattr->valid & NFS_ATTR_FATTR_NLINK) && inode->i_nlink != fattr->nlink)
1527 		invalid |= NFS_INO_INVALID_NLINK;
1528 
1529 	ts = inode->i_atime;
1530 	if ((fattr->valid & NFS_ATTR_FATTR_ATIME) && !timespec64_equal(&ts, &fattr->atime))
1531 		invalid |= NFS_INO_INVALID_ATIME;
1532 
1533 	if (invalid != 0)
1534 		nfs_set_cache_invalid(inode, invalid);
1535 
1536 	nfsi->read_cache_jiffies = fattr->time_start;
1537 	return 0;
1538 }
1539 
1540 static atomic_long_t nfs_attr_generation_counter;
1541 
1542 static unsigned long nfs_read_attr_generation_counter(void)
1543 {
1544 	return atomic_long_read(&nfs_attr_generation_counter);
1545 }
1546 
1547 unsigned long nfs_inc_attr_generation_counter(void)
1548 {
1549 	return atomic_long_inc_return(&nfs_attr_generation_counter);
1550 }
1551 EXPORT_SYMBOL_GPL(nfs_inc_attr_generation_counter);
1552 
1553 void nfs_fattr_init(struct nfs_fattr *fattr)
1554 {
1555 	fattr->valid = 0;
1556 	fattr->time_start = jiffies;
1557 	fattr->gencount = nfs_inc_attr_generation_counter();
1558 	fattr->owner_name = NULL;
1559 	fattr->group_name = NULL;
1560 }
1561 EXPORT_SYMBOL_GPL(nfs_fattr_init);
1562 
1563 /**
1564  * nfs_fattr_set_barrier
1565  * @fattr: attributes
1566  *
1567  * Used to set a barrier after an attribute was updated. This
1568  * barrier ensures that older attributes from RPC calls that may
1569  * have raced with our update cannot clobber these new values.
1570  * Note that you are still responsible for ensuring that other
1571  * operations which change the attribute on the server do not
1572  * collide.
1573  */
1574 void nfs_fattr_set_barrier(struct nfs_fattr *fattr)
1575 {
1576 	fattr->gencount = nfs_inc_attr_generation_counter();
1577 }
1578 
1579 struct nfs_fattr *nfs_alloc_fattr(void)
1580 {
1581 	struct nfs_fattr *fattr;
1582 
1583 	fattr = kmalloc(sizeof(*fattr), GFP_KERNEL);
1584 	if (fattr != NULL) {
1585 		nfs_fattr_init(fattr);
1586 		fattr->label = NULL;
1587 	}
1588 	return fattr;
1589 }
1590 EXPORT_SYMBOL_GPL(nfs_alloc_fattr);
1591 
1592 struct nfs_fattr *nfs_alloc_fattr_with_label(struct nfs_server *server)
1593 {
1594 	struct nfs_fattr *fattr = nfs_alloc_fattr();
1595 
1596 	if (!fattr)
1597 		return NULL;
1598 
1599 	fattr->label = nfs4_label_alloc(server, GFP_KERNEL);
1600 	if (IS_ERR(fattr->label)) {
1601 		kfree(fattr);
1602 		return NULL;
1603 	}
1604 
1605 	return fattr;
1606 }
1607 EXPORT_SYMBOL_GPL(nfs_alloc_fattr_with_label);
1608 
1609 struct nfs_fh *nfs_alloc_fhandle(void)
1610 {
1611 	struct nfs_fh *fh;
1612 
1613 	fh = kmalloc(sizeof(struct nfs_fh), GFP_KERNEL);
1614 	if (fh != NULL)
1615 		fh->size = 0;
1616 	return fh;
1617 }
1618 EXPORT_SYMBOL_GPL(nfs_alloc_fhandle);
1619 
1620 #ifdef NFS_DEBUG
1621 /*
1622  * _nfs_display_fhandle_hash - calculate the crc32 hash for the filehandle
1623  *                             in the same way that wireshark does
1624  *
1625  * @fh: file handle
1626  *
1627  * For debugging only.
1628  */
1629 u32 _nfs_display_fhandle_hash(const struct nfs_fh *fh)
1630 {
1631 	/* wireshark uses 32-bit AUTODIN crc and does a bitwise
1632 	 * not on the result */
1633 	return nfs_fhandle_hash(fh);
1634 }
1635 EXPORT_SYMBOL_GPL(_nfs_display_fhandle_hash);
1636 
1637 /*
1638  * _nfs_display_fhandle - display an NFS file handle on the console
1639  *
1640  * @fh: file handle to display
1641  * @caption: display caption
1642  *
1643  * For debugging only.
1644  */
1645 void _nfs_display_fhandle(const struct nfs_fh *fh, const char *caption)
1646 {
1647 	unsigned short i;
1648 
1649 	if (fh == NULL || fh->size == 0) {
1650 		printk(KERN_DEFAULT "%s at %p is empty\n", caption, fh);
1651 		return;
1652 	}
1653 
1654 	printk(KERN_DEFAULT "%s at %p is %u bytes, crc: 0x%08x:\n",
1655 	       caption, fh, fh->size, _nfs_display_fhandle_hash(fh));
1656 	for (i = 0; i < fh->size; i += 16) {
1657 		__be32 *pos = (__be32 *)&fh->data[i];
1658 
1659 		switch ((fh->size - i - 1) >> 2) {
1660 		case 0:
1661 			printk(KERN_DEFAULT " %08x\n",
1662 				be32_to_cpup(pos));
1663 			break;
1664 		case 1:
1665 			printk(KERN_DEFAULT " %08x %08x\n",
1666 				be32_to_cpup(pos), be32_to_cpup(pos + 1));
1667 			break;
1668 		case 2:
1669 			printk(KERN_DEFAULT " %08x %08x %08x\n",
1670 				be32_to_cpup(pos), be32_to_cpup(pos + 1),
1671 				be32_to_cpup(pos + 2));
1672 			break;
1673 		default:
1674 			printk(KERN_DEFAULT " %08x %08x %08x %08x\n",
1675 				be32_to_cpup(pos), be32_to_cpup(pos + 1),
1676 				be32_to_cpup(pos + 2), be32_to_cpup(pos + 3));
1677 		}
1678 	}
1679 }
1680 EXPORT_SYMBOL_GPL(_nfs_display_fhandle);
1681 #endif
1682 
1683 /**
1684  * nfs_inode_attrs_cmp_generic - compare attributes
1685  * @fattr: attributes
1686  * @inode: pointer to inode
1687  *
1688  * Attempt to divine whether or not an RPC call reply carrying stale
1689  * attributes got scheduled after another call carrying updated ones.
1690  * Note also the check for wraparound of 'attr_gencount'
1691  *
1692  * The function returns '1' if it thinks the attributes in @fattr are
1693  * more recent than the ones cached in @inode. Otherwise it returns
1694  * the value '0'.
1695  */
1696 static int nfs_inode_attrs_cmp_generic(const struct nfs_fattr *fattr,
1697 				       const struct inode *inode)
1698 {
1699 	unsigned long attr_gencount = NFS_I(inode)->attr_gencount;
1700 
1701 	return (long)(fattr->gencount - attr_gencount) > 0 ||
1702 	       (long)(attr_gencount - nfs_read_attr_generation_counter()) > 0;
1703 }
1704 
1705 /**
1706  * nfs_inode_attrs_cmp_monotonic - compare attributes
1707  * @fattr: attributes
1708  * @inode: pointer to inode
1709  *
1710  * Attempt to divine whether or not an RPC call reply carrying stale
1711  * attributes got scheduled after another call carrying updated ones.
1712  *
1713  * We assume that the server observes monotonic semantics for
1714  * the change attribute, so a larger value means that the attributes in
1715  * @fattr are more recent, in which case the function returns the
1716  * value '1'.
1717  * A return value of '0' indicates no measurable change
1718  * A return value of '-1' means that the attributes in @inode are
1719  * more recent.
1720  */
1721 static int nfs_inode_attrs_cmp_monotonic(const struct nfs_fattr *fattr,
1722 					 const struct inode *inode)
1723 {
1724 	s64 diff = fattr->change_attr - inode_peek_iversion_raw(inode);
1725 	if (diff > 0)
1726 		return 1;
1727 	return diff == 0 ? 0 : -1;
1728 }
1729 
1730 /**
1731  * nfs_inode_attrs_cmp_strict_monotonic - compare attributes
1732  * @fattr: attributes
1733  * @inode: pointer to inode
1734  *
1735  * Attempt to divine whether or not an RPC call reply carrying stale
1736  * attributes got scheduled after another call carrying updated ones.
1737  *
1738  * We assume that the server observes strictly monotonic semantics for
1739  * the change attribute, so a larger value means that the attributes in
1740  * @fattr are more recent, in which case the function returns the
1741  * value '1'.
1742  * A return value of '-1' means that the attributes in @inode are
1743  * more recent or unchanged.
1744  */
1745 static int nfs_inode_attrs_cmp_strict_monotonic(const struct nfs_fattr *fattr,
1746 						const struct inode *inode)
1747 {
1748 	return  nfs_inode_attrs_cmp_monotonic(fattr, inode) > 0 ? 1 : -1;
1749 }
1750 
1751 /**
1752  * nfs_inode_attrs_cmp - compare attributes
1753  * @fattr: attributes
1754  * @inode: pointer to inode
1755  *
1756  * This function returns '1' if it thinks the attributes in @fattr are
1757  * more recent than the ones cached in @inode. It returns '-1' if
1758  * the attributes in @inode are more recent than the ones in @fattr,
1759  * and it returns 0 if not sure.
1760  */
1761 static int nfs_inode_attrs_cmp(const struct nfs_fattr *fattr,
1762 			       const struct inode *inode)
1763 {
1764 	if (nfs_inode_attrs_cmp_generic(fattr, inode) > 0)
1765 		return 1;
1766 	switch (NFS_SERVER(inode)->change_attr_type) {
1767 	case NFS4_CHANGE_TYPE_IS_UNDEFINED:
1768 		break;
1769 	case NFS4_CHANGE_TYPE_IS_TIME_METADATA:
1770 		if (!(fattr->valid & NFS_ATTR_FATTR_CHANGE))
1771 			break;
1772 		return nfs_inode_attrs_cmp_monotonic(fattr, inode);
1773 	default:
1774 		if (!(fattr->valid & NFS_ATTR_FATTR_CHANGE))
1775 			break;
1776 		return nfs_inode_attrs_cmp_strict_monotonic(fattr, inode);
1777 	}
1778 	return 0;
1779 }
1780 
1781 /**
1782  * nfs_inode_finish_partial_attr_update - complete a previous inode update
1783  * @fattr: attributes
1784  * @inode: pointer to inode
1785  *
1786  * Returns '1' if the last attribute update left the inode cached
1787  * attributes in a partially unrevalidated state, and @fattr
1788  * matches the change attribute of that partial update.
1789  * Otherwise returns '0'.
1790  */
1791 static int nfs_inode_finish_partial_attr_update(const struct nfs_fattr *fattr,
1792 						const struct inode *inode)
1793 {
1794 	const unsigned long check_valid =
1795 		NFS_INO_INVALID_ATIME | NFS_INO_INVALID_CTIME |
1796 		NFS_INO_INVALID_MTIME | NFS_INO_INVALID_SIZE |
1797 		NFS_INO_INVALID_BLOCKS | NFS_INO_INVALID_OTHER |
1798 		NFS_INO_INVALID_NLINK;
1799 	unsigned long cache_validity = NFS_I(inode)->cache_validity;
1800 	enum nfs4_change_attr_type ctype = NFS_SERVER(inode)->change_attr_type;
1801 
1802 	if (ctype != NFS4_CHANGE_TYPE_IS_UNDEFINED &&
1803 	    !(cache_validity & NFS_INO_INVALID_CHANGE) &&
1804 	    (cache_validity & check_valid) != 0 &&
1805 	    (fattr->valid & NFS_ATTR_FATTR_CHANGE) != 0 &&
1806 	    nfs_inode_attrs_cmp_monotonic(fattr, inode) == 0)
1807 		return 1;
1808 	return 0;
1809 }
1810 
1811 static int nfs_refresh_inode_locked(struct inode *inode,
1812 				    struct nfs_fattr *fattr)
1813 {
1814 	int attr_cmp = nfs_inode_attrs_cmp(fattr, inode);
1815 	int ret = 0;
1816 
1817 	trace_nfs_refresh_inode_enter(inode);
1818 
1819 	if (attr_cmp > 0 || nfs_inode_finish_partial_attr_update(fattr, inode))
1820 		ret = nfs_update_inode(inode, fattr);
1821 	else if (attr_cmp == 0)
1822 		ret = nfs_check_inode_attributes(inode, fattr);
1823 
1824 	trace_nfs_refresh_inode_exit(inode, ret);
1825 	return ret;
1826 }
1827 
1828 /**
1829  * nfs_refresh_inode - try to update the inode attribute cache
1830  * @inode: pointer to inode
1831  * @fattr: updated attributes
1832  *
1833  * Check that an RPC call that returned attributes has not overlapped with
1834  * other recent updates of the inode metadata, then decide whether it is
1835  * safe to do a full update of the inode attributes, or whether just to
1836  * call nfs_check_inode_attributes.
1837  */
1838 int nfs_refresh_inode(struct inode *inode, struct nfs_fattr *fattr)
1839 {
1840 	int status;
1841 
1842 	if ((fattr->valid & NFS_ATTR_FATTR) == 0)
1843 		return 0;
1844 	spin_lock(&inode->i_lock);
1845 	status = nfs_refresh_inode_locked(inode, fattr);
1846 	spin_unlock(&inode->i_lock);
1847 
1848 	return status;
1849 }
1850 EXPORT_SYMBOL_GPL(nfs_refresh_inode);
1851 
1852 static int nfs_post_op_update_inode_locked(struct inode *inode,
1853 		struct nfs_fattr *fattr, unsigned int invalid)
1854 {
1855 	if (S_ISDIR(inode->i_mode))
1856 		invalid |= NFS_INO_INVALID_DATA;
1857 	nfs_set_cache_invalid(inode, invalid);
1858 	if ((fattr->valid & NFS_ATTR_FATTR) == 0)
1859 		return 0;
1860 	return nfs_refresh_inode_locked(inode, fattr);
1861 }
1862 
1863 /**
1864  * nfs_post_op_update_inode - try to update the inode attribute cache
1865  * @inode: pointer to inode
1866  * @fattr: updated attributes
1867  *
1868  * After an operation that has changed the inode metadata, mark the
1869  * attribute cache as being invalid, then try to update it.
1870  *
1871  * NB: if the server didn't return any post op attributes, this
1872  * function will force the retrieval of attributes before the next
1873  * NFS request.  Thus it should be used only for operations that
1874  * are expected to change one or more attributes, to avoid
1875  * unnecessary NFS requests and trips through nfs_update_inode().
1876  */
1877 int nfs_post_op_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1878 {
1879 	int status;
1880 
1881 	spin_lock(&inode->i_lock);
1882 	nfs_fattr_set_barrier(fattr);
1883 	status = nfs_post_op_update_inode_locked(inode, fattr,
1884 			NFS_INO_INVALID_CHANGE
1885 			| NFS_INO_INVALID_CTIME
1886 			| NFS_INO_REVAL_FORCED);
1887 	spin_unlock(&inode->i_lock);
1888 
1889 	return status;
1890 }
1891 EXPORT_SYMBOL_GPL(nfs_post_op_update_inode);
1892 
1893 /**
1894  * nfs_post_op_update_inode_force_wcc_locked - update the inode attribute cache
1895  * @inode: pointer to inode
1896  * @fattr: updated attributes
1897  *
1898  * After an operation that has changed the inode metadata, mark the
1899  * attribute cache as being invalid, then try to update it. Fake up
1900  * weak cache consistency data, if none exist.
1901  *
1902  * This function is mainly designed to be used by the ->write_done() functions.
1903  */
1904 int nfs_post_op_update_inode_force_wcc_locked(struct inode *inode, struct nfs_fattr *fattr)
1905 {
1906 	int attr_cmp = nfs_inode_attrs_cmp(fattr, inode);
1907 	int status;
1908 
1909 	/* Don't do a WCC update if these attributes are already stale */
1910 	if (attr_cmp < 0)
1911 		return 0;
1912 	if ((fattr->valid & NFS_ATTR_FATTR) == 0 || !attr_cmp) {
1913 		fattr->valid &= ~(NFS_ATTR_FATTR_PRECHANGE
1914 				| NFS_ATTR_FATTR_PRESIZE
1915 				| NFS_ATTR_FATTR_PREMTIME
1916 				| NFS_ATTR_FATTR_PRECTIME);
1917 		goto out_noforce;
1918 	}
1919 	if ((fattr->valid & NFS_ATTR_FATTR_CHANGE) != 0 &&
1920 			(fattr->valid & NFS_ATTR_FATTR_PRECHANGE) == 0) {
1921 		fattr->pre_change_attr = inode_peek_iversion_raw(inode);
1922 		fattr->valid |= NFS_ATTR_FATTR_PRECHANGE;
1923 	}
1924 	if ((fattr->valid & NFS_ATTR_FATTR_CTIME) != 0 &&
1925 			(fattr->valid & NFS_ATTR_FATTR_PRECTIME) == 0) {
1926 		fattr->pre_ctime = inode->i_ctime;
1927 		fattr->valid |= NFS_ATTR_FATTR_PRECTIME;
1928 	}
1929 	if ((fattr->valid & NFS_ATTR_FATTR_MTIME) != 0 &&
1930 			(fattr->valid & NFS_ATTR_FATTR_PREMTIME) == 0) {
1931 		fattr->pre_mtime = inode->i_mtime;
1932 		fattr->valid |= NFS_ATTR_FATTR_PREMTIME;
1933 	}
1934 	if ((fattr->valid & NFS_ATTR_FATTR_SIZE) != 0 &&
1935 			(fattr->valid & NFS_ATTR_FATTR_PRESIZE) == 0) {
1936 		fattr->pre_size = i_size_read(inode);
1937 		fattr->valid |= NFS_ATTR_FATTR_PRESIZE;
1938 	}
1939 out_noforce:
1940 	status = nfs_post_op_update_inode_locked(inode, fattr,
1941 			NFS_INO_INVALID_CHANGE
1942 			| NFS_INO_INVALID_CTIME
1943 			| NFS_INO_INVALID_MTIME
1944 			| NFS_INO_INVALID_BLOCKS);
1945 	return status;
1946 }
1947 
1948 /**
1949  * nfs_post_op_update_inode_force_wcc - try to update the inode attribute cache
1950  * @inode: pointer to inode
1951  * @fattr: updated attributes
1952  *
1953  * After an operation that has changed the inode metadata, mark the
1954  * attribute cache as being invalid, then try to update it. Fake up
1955  * weak cache consistency data, if none exist.
1956  *
1957  * This function is mainly designed to be used by the ->write_done() functions.
1958  */
1959 int nfs_post_op_update_inode_force_wcc(struct inode *inode, struct nfs_fattr *fattr)
1960 {
1961 	int status;
1962 
1963 	spin_lock(&inode->i_lock);
1964 	nfs_fattr_set_barrier(fattr);
1965 	status = nfs_post_op_update_inode_force_wcc_locked(inode, fattr);
1966 	spin_unlock(&inode->i_lock);
1967 	return status;
1968 }
1969 EXPORT_SYMBOL_GPL(nfs_post_op_update_inode_force_wcc);
1970 
1971 
1972 /*
1973  * Many nfs protocol calls return the new file attributes after
1974  * an operation.  Here we update the inode to reflect the state
1975  * of the server's inode.
1976  *
1977  * This is a bit tricky because we have to make sure all dirty pages
1978  * have been sent off to the server before calling invalidate_inode_pages.
1979  * To make sure no other process adds more write requests while we try
1980  * our best to flush them, we make them sleep during the attribute refresh.
1981  *
1982  * A very similar scenario holds for the dir cache.
1983  */
1984 static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1985 {
1986 	struct nfs_server *server = NFS_SERVER(inode);
1987 	struct nfs_inode *nfsi = NFS_I(inode);
1988 	loff_t cur_isize, new_isize;
1989 	u64 fattr_supported = server->fattr_valid;
1990 	unsigned long invalid = 0;
1991 	unsigned long now = jiffies;
1992 	unsigned long save_cache_validity;
1993 	bool have_writers = nfs_file_has_buffered_writers(nfsi);
1994 	bool cache_revalidated = true;
1995 	bool attr_changed = false;
1996 	bool have_delegation;
1997 
1998 	dfprintk(VFS, "NFS: %s(%s/%lu fh_crc=0x%08x ct=%d info=0x%x)\n",
1999 			__func__, inode->i_sb->s_id, inode->i_ino,
2000 			nfs_display_fhandle_hash(NFS_FH(inode)),
2001 			atomic_read(&inode->i_count), fattr->valid);
2002 
2003 	if (!(fattr->valid & NFS_ATTR_FATTR_FILEID)) {
2004 		/* Only a mounted-on-fileid? Just exit */
2005 		if (fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID)
2006 			return 0;
2007 	/* Has the inode gone and changed behind our back? */
2008 	} else if (nfsi->fileid != fattr->fileid) {
2009 		/* Is this perhaps the mounted-on fileid? */
2010 		if ((fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID) &&
2011 		    nfsi->fileid == fattr->mounted_on_fileid)
2012 			return 0;
2013 		printk(KERN_ERR "NFS: server %s error: fileid changed\n"
2014 			"fsid %s: expected fileid 0x%Lx, got 0x%Lx\n",
2015 			NFS_SERVER(inode)->nfs_client->cl_hostname,
2016 			inode->i_sb->s_id, (long long)nfsi->fileid,
2017 			(long long)fattr->fileid);
2018 		goto out_err;
2019 	}
2020 
2021 	/*
2022 	 * Make sure the inode's type hasn't changed.
2023 	 */
2024 	if ((fattr->valid & NFS_ATTR_FATTR_TYPE) && inode_wrong_type(inode, fattr->mode)) {
2025 		/*
2026 		* Big trouble! The inode has become a different object.
2027 		*/
2028 		printk(KERN_DEBUG "NFS: %s: inode %lu mode changed, %07o to %07o\n",
2029 				__func__, inode->i_ino, inode->i_mode, fattr->mode);
2030 		goto out_err;
2031 	}
2032 
2033 	/* Update the fsid? */
2034 	if (S_ISDIR(inode->i_mode) && (fattr->valid & NFS_ATTR_FATTR_FSID) &&
2035 			!nfs_fsid_equal(&server->fsid, &fattr->fsid) &&
2036 			!IS_AUTOMOUNT(inode))
2037 		server->fsid = fattr->fsid;
2038 
2039 	/* Save the delegation state before clearing cache_validity */
2040 	have_delegation = nfs_have_delegated_attributes(inode);
2041 
2042 	/*
2043 	 * Update the read time so we don't revalidate too often.
2044 	 */
2045 	nfsi->read_cache_jiffies = fattr->time_start;
2046 
2047 	save_cache_validity = nfsi->cache_validity;
2048 	nfsi->cache_validity &= ~(NFS_INO_INVALID_ATTR
2049 			| NFS_INO_INVALID_ATIME
2050 			| NFS_INO_REVAL_FORCED
2051 			| NFS_INO_INVALID_BLOCKS);
2052 
2053 	/* Do atomic weak cache consistency updates */
2054 	nfs_wcc_update_inode(inode, fattr);
2055 
2056 	if (pnfs_layoutcommit_outstanding(inode)) {
2057 		nfsi->cache_validity |=
2058 			save_cache_validity &
2059 			(NFS_INO_INVALID_CHANGE | NFS_INO_INVALID_CTIME |
2060 			 NFS_INO_INVALID_MTIME | NFS_INO_INVALID_SIZE |
2061 			 NFS_INO_INVALID_BLOCKS);
2062 		cache_revalidated = false;
2063 	}
2064 
2065 	/* More cache consistency checks */
2066 	if (fattr->valid & NFS_ATTR_FATTR_CHANGE) {
2067 		if (!inode_eq_iversion_raw(inode, fattr->change_attr)) {
2068 			/* Could it be a race with writeback? */
2069 			if (!(have_writers || have_delegation)) {
2070 				invalid |= NFS_INO_INVALID_DATA
2071 					| NFS_INO_INVALID_ACCESS
2072 					| NFS_INO_INVALID_ACL
2073 					| NFS_INO_INVALID_XATTR;
2074 				/* Force revalidate of all attributes */
2075 				save_cache_validity |= NFS_INO_INVALID_CTIME
2076 					| NFS_INO_INVALID_MTIME
2077 					| NFS_INO_INVALID_SIZE
2078 					| NFS_INO_INVALID_BLOCKS
2079 					| NFS_INO_INVALID_NLINK
2080 					| NFS_INO_INVALID_MODE
2081 					| NFS_INO_INVALID_OTHER;
2082 				if (S_ISDIR(inode->i_mode))
2083 					nfs_force_lookup_revalidate(inode);
2084 				attr_changed = true;
2085 				dprintk("NFS: change_attr change on server for file %s/%ld\n",
2086 						inode->i_sb->s_id,
2087 						inode->i_ino);
2088 			} else if (!have_delegation)
2089 				nfsi->cache_validity |= NFS_INO_DATA_INVAL_DEFER;
2090 			inode_set_iversion_raw(inode, fattr->change_attr);
2091 		}
2092 	} else {
2093 		nfsi->cache_validity |=
2094 			save_cache_validity & NFS_INO_INVALID_CHANGE;
2095 		if (!have_delegation ||
2096 		    (nfsi->cache_validity & NFS_INO_INVALID_CHANGE) != 0)
2097 			cache_revalidated = false;
2098 	}
2099 
2100 	if (fattr->valid & NFS_ATTR_FATTR_MTIME)
2101 		inode->i_mtime = fattr->mtime;
2102 	else if (fattr_supported & NFS_ATTR_FATTR_MTIME)
2103 		nfsi->cache_validity |=
2104 			save_cache_validity & NFS_INO_INVALID_MTIME;
2105 
2106 	if (fattr->valid & NFS_ATTR_FATTR_CTIME)
2107 		inode->i_ctime = fattr->ctime;
2108 	else if (fattr_supported & NFS_ATTR_FATTR_CTIME)
2109 		nfsi->cache_validity |=
2110 			save_cache_validity & NFS_INO_INVALID_CTIME;
2111 
2112 	/* Check if our cached file size is stale */
2113 	if (fattr->valid & NFS_ATTR_FATTR_SIZE) {
2114 		new_isize = nfs_size_to_loff_t(fattr->size);
2115 		cur_isize = i_size_read(inode);
2116 		if (new_isize != cur_isize && !have_delegation) {
2117 			/* Do we perhaps have any outstanding writes, or has
2118 			 * the file grown beyond our last write? */
2119 			if (!nfs_have_writebacks(inode) || new_isize > cur_isize) {
2120 				trace_nfs_size_update(inode, new_isize);
2121 				i_size_write(inode, new_isize);
2122 				if (!have_writers)
2123 					invalid |= NFS_INO_INVALID_DATA;
2124 			}
2125 		}
2126 		if (new_isize == 0 &&
2127 		    !(fattr->valid & (NFS_ATTR_FATTR_SPACE_USED |
2128 				      NFS_ATTR_FATTR_BLOCKS_USED))) {
2129 			fattr->du.nfs3.used = 0;
2130 			fattr->valid |= NFS_ATTR_FATTR_SPACE_USED;
2131 		}
2132 	} else
2133 		nfsi->cache_validity |=
2134 			save_cache_validity & NFS_INO_INVALID_SIZE;
2135 
2136 	if (fattr->valid & NFS_ATTR_FATTR_ATIME)
2137 		inode->i_atime = fattr->atime;
2138 	else if (fattr_supported & NFS_ATTR_FATTR_ATIME)
2139 		nfsi->cache_validity |=
2140 			save_cache_validity & NFS_INO_INVALID_ATIME;
2141 
2142 	if (fattr->valid & NFS_ATTR_FATTR_MODE) {
2143 		if ((inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO)) {
2144 			umode_t newmode = inode->i_mode & S_IFMT;
2145 			newmode |= fattr->mode & S_IALLUGO;
2146 			inode->i_mode = newmode;
2147 			invalid |= NFS_INO_INVALID_ACCESS
2148 				| NFS_INO_INVALID_ACL;
2149 		}
2150 	} else if (fattr_supported & NFS_ATTR_FATTR_MODE)
2151 		nfsi->cache_validity |=
2152 			save_cache_validity & NFS_INO_INVALID_MODE;
2153 
2154 	if (fattr->valid & NFS_ATTR_FATTR_OWNER) {
2155 		if (!uid_eq(inode->i_uid, fattr->uid)) {
2156 			invalid |= NFS_INO_INVALID_ACCESS
2157 				| NFS_INO_INVALID_ACL;
2158 			inode->i_uid = fattr->uid;
2159 		}
2160 	} else if (fattr_supported & NFS_ATTR_FATTR_OWNER)
2161 		nfsi->cache_validity |=
2162 			save_cache_validity & NFS_INO_INVALID_OTHER;
2163 
2164 	if (fattr->valid & NFS_ATTR_FATTR_GROUP) {
2165 		if (!gid_eq(inode->i_gid, fattr->gid)) {
2166 			invalid |= NFS_INO_INVALID_ACCESS
2167 				| NFS_INO_INVALID_ACL;
2168 			inode->i_gid = fattr->gid;
2169 		}
2170 	} else if (fattr_supported & NFS_ATTR_FATTR_GROUP)
2171 		nfsi->cache_validity |=
2172 			save_cache_validity & NFS_INO_INVALID_OTHER;
2173 
2174 	if (fattr->valid & NFS_ATTR_FATTR_NLINK) {
2175 		if (inode->i_nlink != fattr->nlink)
2176 			set_nlink(inode, fattr->nlink);
2177 	} else if (fattr_supported & NFS_ATTR_FATTR_NLINK)
2178 		nfsi->cache_validity |=
2179 			save_cache_validity & NFS_INO_INVALID_NLINK;
2180 
2181 	if (fattr->valid & NFS_ATTR_FATTR_SPACE_USED) {
2182 		/*
2183 		 * report the blocks in 512byte units
2184 		 */
2185 		inode->i_blocks = nfs_calc_block_size(fattr->du.nfs3.used);
2186 	} else if (fattr_supported & NFS_ATTR_FATTR_SPACE_USED)
2187 		nfsi->cache_validity |=
2188 			save_cache_validity & NFS_INO_INVALID_BLOCKS;
2189 
2190 	if (fattr->valid & NFS_ATTR_FATTR_BLOCKS_USED)
2191 		inode->i_blocks = fattr->du.nfs2.blocks;
2192 	else if (fattr_supported & NFS_ATTR_FATTR_BLOCKS_USED)
2193 		nfsi->cache_validity |=
2194 			save_cache_validity & NFS_INO_INVALID_BLOCKS;
2195 
2196 	/* Update attrtimeo value if we're out of the unstable period */
2197 	if (attr_changed) {
2198 		nfs_inc_stats(inode, NFSIOS_ATTRINVALIDATE);
2199 		nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
2200 		nfsi->attrtimeo_timestamp = now;
2201 		/* Set barrier to be more recent than all outstanding updates */
2202 		nfsi->attr_gencount = nfs_inc_attr_generation_counter();
2203 	} else {
2204 		if (cache_revalidated) {
2205 			if (!time_in_range_open(now, nfsi->attrtimeo_timestamp,
2206 				nfsi->attrtimeo_timestamp + nfsi->attrtimeo)) {
2207 				nfsi->attrtimeo <<= 1;
2208 				if (nfsi->attrtimeo > NFS_MAXATTRTIMEO(inode))
2209 					nfsi->attrtimeo = NFS_MAXATTRTIMEO(inode);
2210 			}
2211 			nfsi->attrtimeo_timestamp = now;
2212 		}
2213 		/* Set the barrier to be more recent than this fattr */
2214 		if ((long)(fattr->gencount - nfsi->attr_gencount) > 0)
2215 			nfsi->attr_gencount = fattr->gencount;
2216 	}
2217 
2218 	/* Don't invalidate the data if we were to blame */
2219 	if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)
2220 				|| S_ISLNK(inode->i_mode)))
2221 		invalid &= ~NFS_INO_INVALID_DATA;
2222 	nfs_set_cache_invalid(inode, invalid);
2223 
2224 	return 0;
2225  out_err:
2226 	/*
2227 	 * No need to worry about unhashing the dentry, as the
2228 	 * lookup validation will know that the inode is bad.
2229 	 * (But we fall through to invalidate the caches.)
2230 	 */
2231 	nfs_set_inode_stale_locked(inode);
2232 	return -ESTALE;
2233 }
2234 
2235 struct inode *nfs_alloc_inode(struct super_block *sb)
2236 {
2237 	struct nfs_inode *nfsi;
2238 	nfsi = alloc_inode_sb(sb, nfs_inode_cachep, GFP_KERNEL);
2239 	if (!nfsi)
2240 		return NULL;
2241 	nfsi->flags = 0UL;
2242 	nfsi->cache_validity = 0UL;
2243 #if IS_ENABLED(CONFIG_NFS_V4)
2244 	nfsi->nfs4_acl = NULL;
2245 #endif /* CONFIG_NFS_V4 */
2246 #ifdef CONFIG_NFS_V4_2
2247 	nfsi->xattr_cache = NULL;
2248 #endif
2249 	return &nfsi->vfs_inode;
2250 }
2251 EXPORT_SYMBOL_GPL(nfs_alloc_inode);
2252 
2253 void nfs_free_inode(struct inode *inode)
2254 {
2255 	kmem_cache_free(nfs_inode_cachep, NFS_I(inode));
2256 }
2257 EXPORT_SYMBOL_GPL(nfs_free_inode);
2258 
2259 static inline void nfs4_init_once(struct nfs_inode *nfsi)
2260 {
2261 #if IS_ENABLED(CONFIG_NFS_V4)
2262 	INIT_LIST_HEAD(&nfsi->open_states);
2263 	nfsi->delegation = NULL;
2264 	init_rwsem(&nfsi->rwsem);
2265 	nfsi->layout = NULL;
2266 #endif
2267 }
2268 
2269 static void init_once(void *foo)
2270 {
2271 	struct nfs_inode *nfsi = foo;
2272 
2273 	inode_init_once(&nfsi->vfs_inode);
2274 	INIT_LIST_HEAD(&nfsi->open_files);
2275 	INIT_LIST_HEAD(&nfsi->access_cache_entry_lru);
2276 	INIT_LIST_HEAD(&nfsi->access_cache_inode_lru);
2277 	nfs4_init_once(nfsi);
2278 }
2279 
2280 static int __init nfs_init_inodecache(void)
2281 {
2282 	nfs_inode_cachep = kmem_cache_create("nfs_inode_cache",
2283 					     sizeof(struct nfs_inode),
2284 					     0, (SLAB_RECLAIM_ACCOUNT|
2285 						SLAB_MEM_SPREAD|SLAB_ACCOUNT),
2286 					     init_once);
2287 	if (nfs_inode_cachep == NULL)
2288 		return -ENOMEM;
2289 
2290 	return 0;
2291 }
2292 
2293 static void nfs_destroy_inodecache(void)
2294 {
2295 	/*
2296 	 * Make sure all delayed rcu free inodes are flushed before we
2297 	 * destroy cache.
2298 	 */
2299 	rcu_barrier();
2300 	kmem_cache_destroy(nfs_inode_cachep);
2301 }
2302 
2303 struct workqueue_struct *nfsiod_workqueue;
2304 EXPORT_SYMBOL_GPL(nfsiod_workqueue);
2305 
2306 /*
2307  * start up the nfsiod workqueue
2308  */
2309 static int nfsiod_start(void)
2310 {
2311 	struct workqueue_struct *wq;
2312 	dprintk("RPC:       creating workqueue nfsiod\n");
2313 	wq = alloc_workqueue("nfsiod", WQ_MEM_RECLAIM | WQ_UNBOUND, 0);
2314 	if (wq == NULL)
2315 		return -ENOMEM;
2316 	nfsiod_workqueue = wq;
2317 	return 0;
2318 }
2319 
2320 /*
2321  * Destroy the nfsiod workqueue
2322  */
2323 static void nfsiod_stop(void)
2324 {
2325 	struct workqueue_struct *wq;
2326 
2327 	wq = nfsiod_workqueue;
2328 	if (wq == NULL)
2329 		return;
2330 	nfsiod_workqueue = NULL;
2331 	destroy_workqueue(wq);
2332 }
2333 
2334 unsigned int nfs_net_id;
2335 EXPORT_SYMBOL_GPL(nfs_net_id);
2336 
2337 static int nfs_net_init(struct net *net)
2338 {
2339 	nfs_clients_init(net);
2340 	return nfs_fs_proc_net_init(net);
2341 }
2342 
2343 static void nfs_net_exit(struct net *net)
2344 {
2345 	nfs_fs_proc_net_exit(net);
2346 	nfs_clients_exit(net);
2347 }
2348 
2349 static struct pernet_operations nfs_net_ops = {
2350 	.init = nfs_net_init,
2351 	.exit = nfs_net_exit,
2352 	.id   = &nfs_net_id,
2353 	.size = sizeof(struct nfs_net),
2354 };
2355 
2356 /*
2357  * Initialize NFS
2358  */
2359 static int __init init_nfs_fs(void)
2360 {
2361 	int err;
2362 
2363 	err = nfs_sysfs_init();
2364 	if (err < 0)
2365 		goto out10;
2366 
2367 	err = register_pernet_subsys(&nfs_net_ops);
2368 	if (err < 0)
2369 		goto out9;
2370 
2371 	err = nfsiod_start();
2372 	if (err)
2373 		goto out7;
2374 
2375 	err = nfs_fs_proc_init();
2376 	if (err)
2377 		goto out6;
2378 
2379 	err = nfs_init_nfspagecache();
2380 	if (err)
2381 		goto out5;
2382 
2383 	err = nfs_init_inodecache();
2384 	if (err)
2385 		goto out4;
2386 
2387 	err = nfs_init_readpagecache();
2388 	if (err)
2389 		goto out3;
2390 
2391 	err = nfs_init_writepagecache();
2392 	if (err)
2393 		goto out2;
2394 
2395 	err = nfs_init_directcache();
2396 	if (err)
2397 		goto out1;
2398 
2399 	rpc_proc_register(&init_net, &nfs_rpcstat);
2400 
2401 	err = register_nfs_fs();
2402 	if (err)
2403 		goto out0;
2404 
2405 	return 0;
2406 out0:
2407 	rpc_proc_unregister(&init_net, "nfs");
2408 	nfs_destroy_directcache();
2409 out1:
2410 	nfs_destroy_writepagecache();
2411 out2:
2412 	nfs_destroy_readpagecache();
2413 out3:
2414 	nfs_destroy_inodecache();
2415 out4:
2416 	nfs_destroy_nfspagecache();
2417 out5:
2418 	nfs_fs_proc_exit();
2419 out6:
2420 	nfsiod_stop();
2421 out7:
2422 	unregister_pernet_subsys(&nfs_net_ops);
2423 out9:
2424 	nfs_sysfs_exit();
2425 out10:
2426 	return err;
2427 }
2428 
2429 static void __exit exit_nfs_fs(void)
2430 {
2431 	nfs_destroy_directcache();
2432 	nfs_destroy_writepagecache();
2433 	nfs_destroy_readpagecache();
2434 	nfs_destroy_inodecache();
2435 	nfs_destroy_nfspagecache();
2436 	unregister_pernet_subsys(&nfs_net_ops);
2437 	rpc_proc_unregister(&init_net, "nfs");
2438 	unregister_nfs_fs();
2439 	nfs_fs_proc_exit();
2440 	nfsiod_stop();
2441 	nfs_sysfs_exit();
2442 }
2443 
2444 /* Not quite true; I just maintain it */
2445 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
2446 MODULE_LICENSE("GPL");
2447 module_param(enable_ino64, bool, 0644);
2448 
2449 module_init(init_nfs_fs)
2450 module_exit(exit_nfs_fs)
2451