xref: /linux/fs/nfs/inode.c (revision 71e2f4dd5a65bd8dbca0b77661e75eea471168f8)
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 void nfs_invalidate_inode(struct inode *);
66 static int nfs_update_inode(struct inode *, struct nfs_fattr *);
67 
68 static struct kmem_cache * nfs_inode_cachep;
69 
70 static inline unsigned long
71 nfs_fattr_to_ino_t(struct nfs_fattr *fattr)
72 {
73 	return nfs_fileid_to_ino_t(fattr->fileid);
74 }
75 
76 static int nfs_wait_killable(int mode)
77 {
78 	freezable_schedule_unsafe();
79 	if (signal_pending_state(mode, current))
80 		return -ERESTARTSYS;
81 	return 0;
82 }
83 
84 int nfs_wait_bit_killable(struct wait_bit_key *key, int mode)
85 {
86 	return nfs_wait_killable(mode);
87 }
88 EXPORT_SYMBOL_GPL(nfs_wait_bit_killable);
89 
90 /**
91  * nfs_compat_user_ino64 - returns the user-visible inode number
92  * @fileid: 64-bit fileid
93  *
94  * This function returns a 32-bit inode number if the boot parameter
95  * nfs.enable_ino64 is zero.
96  */
97 u64 nfs_compat_user_ino64(u64 fileid)
98 {
99 #ifdef CONFIG_COMPAT
100 	compat_ulong_t ino;
101 #else
102 	unsigned long ino;
103 #endif
104 
105 	if (enable_ino64)
106 		return fileid;
107 	ino = fileid;
108 	if (sizeof(ino) < sizeof(fileid))
109 		ino ^= fileid >> (sizeof(fileid)-sizeof(ino)) * 8;
110 	return ino;
111 }
112 
113 int nfs_drop_inode(struct inode *inode)
114 {
115 	return NFS_STALE(inode) || generic_drop_inode(inode);
116 }
117 EXPORT_SYMBOL_GPL(nfs_drop_inode);
118 
119 void nfs_clear_inode(struct inode *inode)
120 {
121 	/*
122 	 * The following should never happen...
123 	 */
124 	WARN_ON_ONCE(nfs_have_writebacks(inode));
125 	WARN_ON_ONCE(!list_empty(&NFS_I(inode)->open_files));
126 	nfs_zap_acl_cache(inode);
127 	nfs_access_zap_cache(inode);
128 	nfs_fscache_clear_inode(inode);
129 }
130 EXPORT_SYMBOL_GPL(nfs_clear_inode);
131 
132 void nfs_evict_inode(struct inode *inode)
133 {
134 	truncate_inode_pages_final(&inode->i_data);
135 	clear_inode(inode);
136 	nfs_clear_inode(inode);
137 }
138 
139 int nfs_sync_inode(struct inode *inode)
140 {
141 	inode_dio_wait(inode);
142 	return nfs_wb_all(inode);
143 }
144 EXPORT_SYMBOL_GPL(nfs_sync_inode);
145 
146 /**
147  * nfs_sync_mapping - helper to flush all mmapped dirty data to disk
148  * @mapping: pointer to struct address_space
149  */
150 int nfs_sync_mapping(struct address_space *mapping)
151 {
152 	int ret = 0;
153 
154 	if (mapping->nrpages != 0) {
155 		unmap_mapping_range(mapping, 0, 0, 0);
156 		ret = nfs_wb_all(mapping->host);
157 	}
158 	return ret;
159 }
160 
161 static int nfs_attribute_timeout(struct inode *inode)
162 {
163 	struct nfs_inode *nfsi = NFS_I(inode);
164 
165 	return !time_in_range_open(jiffies, nfsi->read_cache_jiffies, nfsi->read_cache_jiffies + nfsi->attrtimeo);
166 }
167 
168 static bool nfs_check_cache_invalid_delegated(struct inode *inode, unsigned long flags)
169 {
170 	unsigned long cache_validity = READ_ONCE(NFS_I(inode)->cache_validity);
171 
172 	/* Special case for the pagecache or access cache */
173 	if (flags == NFS_INO_REVAL_PAGECACHE &&
174 	    !(cache_validity & NFS_INO_REVAL_FORCED))
175 		return false;
176 	return (cache_validity & flags) != 0;
177 }
178 
179 static bool nfs_check_cache_invalid_not_delegated(struct inode *inode, unsigned long flags)
180 {
181 	unsigned long cache_validity = READ_ONCE(NFS_I(inode)->cache_validity);
182 
183 	if ((cache_validity & flags) != 0)
184 		return true;
185 	if (nfs_attribute_timeout(inode))
186 		return true;
187 	return false;
188 }
189 
190 bool nfs_check_cache_invalid(struct inode *inode, unsigned long flags)
191 {
192 	if (NFS_PROTO(inode)->have_delegation(inode, FMODE_READ))
193 		return nfs_check_cache_invalid_delegated(inode, flags);
194 
195 	return nfs_check_cache_invalid_not_delegated(inode, flags);
196 }
197 
198 static void nfs_set_cache_invalid(struct inode *inode, unsigned long flags)
199 {
200 	struct nfs_inode *nfsi = NFS_I(inode);
201 	bool have_delegation = NFS_PROTO(inode)->have_delegation(inode, FMODE_READ);
202 
203 	if (have_delegation) {
204 		if (!(flags & NFS_INO_REVAL_FORCED))
205 			flags &= ~NFS_INO_INVALID_OTHER;
206 		flags &= ~(NFS_INO_INVALID_CHANGE
207 				| NFS_INO_INVALID_SIZE
208 				| NFS_INO_REVAL_PAGECACHE);
209 	}
210 
211 	if (inode->i_mapping->nrpages == 0)
212 		flags &= ~(NFS_INO_INVALID_DATA|NFS_INO_DATA_INVAL_DEFER);
213 	nfsi->cache_validity |= flags;
214 	if (flags & NFS_INO_INVALID_DATA)
215 		nfs_fscache_invalidate(inode);
216 }
217 
218 /*
219  * Invalidate the local caches
220  */
221 static void nfs_zap_caches_locked(struct inode *inode)
222 {
223 	struct nfs_inode *nfsi = NFS_I(inode);
224 	int mode = inode->i_mode;
225 
226 	nfs_inc_stats(inode, NFSIOS_ATTRINVALIDATE);
227 
228 	nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
229 	nfsi->attrtimeo_timestamp = jiffies;
230 
231 	memset(NFS_I(inode)->cookieverf, 0, sizeof(NFS_I(inode)->cookieverf));
232 	if (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)) {
233 		nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR
234 					| NFS_INO_INVALID_DATA
235 					| NFS_INO_INVALID_ACCESS
236 					| NFS_INO_INVALID_ACL
237 					| NFS_INO_REVAL_PAGECACHE);
238 	} else
239 		nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR
240 					| NFS_INO_INVALID_ACCESS
241 					| NFS_INO_INVALID_ACL
242 					| NFS_INO_REVAL_PAGECACHE);
243 	nfs_zap_label_cache_locked(nfsi);
244 }
245 
246 void nfs_zap_caches(struct inode *inode)
247 {
248 	spin_lock(&inode->i_lock);
249 	nfs_zap_caches_locked(inode);
250 	spin_unlock(&inode->i_lock);
251 }
252 
253 void nfs_zap_mapping(struct inode *inode, struct address_space *mapping)
254 {
255 	if (mapping->nrpages != 0) {
256 		spin_lock(&inode->i_lock);
257 		nfs_set_cache_invalid(inode, NFS_INO_INVALID_DATA);
258 		spin_unlock(&inode->i_lock);
259 	}
260 }
261 
262 void nfs_zap_acl_cache(struct inode *inode)
263 {
264 	void (*clear_acl_cache)(struct inode *);
265 
266 	clear_acl_cache = NFS_PROTO(inode)->clear_acl_cache;
267 	if (clear_acl_cache != NULL)
268 		clear_acl_cache(inode);
269 	spin_lock(&inode->i_lock);
270 	NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_ACL;
271 	spin_unlock(&inode->i_lock);
272 }
273 EXPORT_SYMBOL_GPL(nfs_zap_acl_cache);
274 
275 void nfs_invalidate_atime(struct inode *inode)
276 {
277 	spin_lock(&inode->i_lock);
278 	nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATIME);
279 	spin_unlock(&inode->i_lock);
280 }
281 EXPORT_SYMBOL_GPL(nfs_invalidate_atime);
282 
283 /*
284  * Invalidate, but do not unhash, the inode.
285  * NB: must be called with inode->i_lock held!
286  */
287 static void nfs_invalidate_inode(struct inode *inode)
288 {
289 	set_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
290 	nfs_zap_caches_locked(inode);
291 }
292 
293 struct nfs_find_desc {
294 	struct nfs_fh		*fh;
295 	struct nfs_fattr	*fattr;
296 };
297 
298 /*
299  * In NFSv3 we can have 64bit inode numbers. In order to support
300  * this, and re-exported directories (also seen in NFSv2)
301  * we are forced to allow 2 different inodes to have the same
302  * i_ino.
303  */
304 static int
305 nfs_find_actor(struct inode *inode, void *opaque)
306 {
307 	struct nfs_find_desc	*desc = (struct nfs_find_desc *)opaque;
308 	struct nfs_fh		*fh = desc->fh;
309 	struct nfs_fattr	*fattr = desc->fattr;
310 
311 	if (NFS_FILEID(inode) != fattr->fileid)
312 		return 0;
313 	if ((S_IFMT & inode->i_mode) != (S_IFMT & fattr->mode))
314 		return 0;
315 	if (nfs_compare_fh(NFS_FH(inode), fh))
316 		return 0;
317 	if (is_bad_inode(inode) || NFS_STALE(inode))
318 		return 0;
319 	return 1;
320 }
321 
322 static int
323 nfs_init_locked(struct inode *inode, void *opaque)
324 {
325 	struct nfs_find_desc	*desc = (struct nfs_find_desc *)opaque;
326 	struct nfs_fattr	*fattr = desc->fattr;
327 
328 	set_nfs_fileid(inode, fattr->fileid);
329 	inode->i_mode = fattr->mode;
330 	nfs_copy_fh(NFS_FH(inode), desc->fh);
331 	return 0;
332 }
333 
334 #ifdef CONFIG_NFS_V4_SECURITY_LABEL
335 static void nfs_clear_label_invalid(struct inode *inode)
336 {
337 	spin_lock(&inode->i_lock);
338 	NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_LABEL;
339 	spin_unlock(&inode->i_lock);
340 }
341 
342 void nfs_setsecurity(struct inode *inode, struct nfs_fattr *fattr,
343 					struct nfs4_label *label)
344 {
345 	int error;
346 
347 	if (label == NULL)
348 		return;
349 
350 	if ((fattr->valid & NFS_ATTR_FATTR_V4_SECURITY_LABEL) && inode->i_security) {
351 		error = security_inode_notifysecctx(inode, label->label,
352 				label->len);
353 		if (error)
354 			printk(KERN_ERR "%s() %s %d "
355 					"security_inode_notifysecctx() %d\n",
356 					__func__,
357 					(char *)label->label,
358 					label->len, error);
359 		nfs_clear_label_invalid(inode);
360 	}
361 }
362 
363 struct nfs4_label *nfs4_label_alloc(struct nfs_server *server, gfp_t flags)
364 {
365 	struct nfs4_label *label = NULL;
366 	int minor_version = server->nfs_client->cl_minorversion;
367 
368 	if (minor_version < 2)
369 		return label;
370 
371 	if (!(server->caps & NFS_CAP_SECURITY_LABEL))
372 		return label;
373 
374 	label = kzalloc(sizeof(struct nfs4_label), flags);
375 	if (label == NULL)
376 		return ERR_PTR(-ENOMEM);
377 
378 	label->label = kzalloc(NFS4_MAXLABELLEN, flags);
379 	if (label->label == NULL) {
380 		kfree(label);
381 		return ERR_PTR(-ENOMEM);
382 	}
383 	label->len = NFS4_MAXLABELLEN;
384 
385 	return label;
386 }
387 EXPORT_SYMBOL_GPL(nfs4_label_alloc);
388 #else
389 void nfs_setsecurity(struct inode *inode, struct nfs_fattr *fattr,
390 					struct nfs4_label *label)
391 {
392 }
393 #endif
394 EXPORT_SYMBOL_GPL(nfs_setsecurity);
395 
396 /* Search for inode identified by fh, fileid and i_mode in inode cache. */
397 struct inode *
398 nfs_ilookup(struct super_block *sb, struct nfs_fattr *fattr, struct nfs_fh *fh)
399 {
400 	struct nfs_find_desc desc = {
401 		.fh	= fh,
402 		.fattr	= fattr,
403 	};
404 	struct inode *inode;
405 	unsigned long hash;
406 
407 	if (!(fattr->valid & NFS_ATTR_FATTR_FILEID) ||
408 	    !(fattr->valid & NFS_ATTR_FATTR_TYPE))
409 		return NULL;
410 
411 	hash = nfs_fattr_to_ino_t(fattr);
412 	inode = ilookup5(sb, hash, nfs_find_actor, &desc);
413 
414 	dprintk("%s: returning %p\n", __func__, inode);
415 	return inode;
416 }
417 
418 /*
419  * This is our front-end to iget that looks up inodes by file handle
420  * instead of inode number.
421  */
422 struct inode *
423 nfs_fhget(struct super_block *sb, struct nfs_fh *fh, struct nfs_fattr *fattr, struct nfs4_label *label)
424 {
425 	struct nfs_find_desc desc = {
426 		.fh	= fh,
427 		.fattr	= fattr
428 	};
429 	struct inode *inode = ERR_PTR(-ENOENT);
430 	unsigned long hash;
431 
432 	nfs_attr_check_mountpoint(sb, fattr);
433 
434 	if (nfs_attr_use_mounted_on_fileid(fattr))
435 		fattr->fileid = fattr->mounted_on_fileid;
436 	else if ((fattr->valid & NFS_ATTR_FATTR_FILEID) == 0)
437 		goto out_no_inode;
438 	if ((fattr->valid & NFS_ATTR_FATTR_TYPE) == 0)
439 		goto out_no_inode;
440 
441 	hash = nfs_fattr_to_ino_t(fattr);
442 
443 	inode = iget5_locked(sb, hash, nfs_find_actor, nfs_init_locked, &desc);
444 	if (inode == NULL) {
445 		inode = ERR_PTR(-ENOMEM);
446 		goto out_no_inode;
447 	}
448 
449 	if (inode->i_state & I_NEW) {
450 		struct nfs_inode *nfsi = NFS_I(inode);
451 		unsigned long now = jiffies;
452 
453 		/* We set i_ino for the few things that still rely on it,
454 		 * such as stat(2) */
455 		inode->i_ino = hash;
456 
457 		/* We can't support update_atime(), since the server will reset it */
458 		inode->i_flags |= S_NOATIME|S_NOCMTIME;
459 		inode->i_mode = fattr->mode;
460 		nfsi->cache_validity = 0;
461 		if ((fattr->valid & NFS_ATTR_FATTR_MODE) == 0
462 				&& nfs_server_capable(inode, NFS_CAP_MODE))
463 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_OTHER);
464 		/* Why so? Because we want revalidate for devices/FIFOs, and
465 		 * that's precisely what we have in nfs_file_inode_operations.
466 		 */
467 		inode->i_op = NFS_SB(sb)->nfs_client->rpc_ops->file_inode_ops;
468 		if (S_ISREG(inode->i_mode)) {
469 			inode->i_fop = NFS_SB(sb)->nfs_client->rpc_ops->file_ops;
470 			inode->i_data.a_ops = &nfs_file_aops;
471 		} else if (S_ISDIR(inode->i_mode)) {
472 			inode->i_op = NFS_SB(sb)->nfs_client->rpc_ops->dir_inode_ops;
473 			inode->i_fop = &nfs_dir_operations;
474 			inode->i_data.a_ops = &nfs_dir_aops;
475 			/* Deal with crossing mountpoints */
476 			if (fattr->valid & NFS_ATTR_FATTR_MOUNTPOINT ||
477 					fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL) {
478 				if (fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL)
479 					inode->i_op = &nfs_referral_inode_operations;
480 				else
481 					inode->i_op = &nfs_mountpoint_inode_operations;
482 				inode->i_fop = NULL;
483 				inode->i_flags |= S_AUTOMOUNT;
484 			}
485 		} else if (S_ISLNK(inode->i_mode)) {
486 			inode->i_op = &nfs_symlink_inode_operations;
487 			inode_nohighmem(inode);
488 		} else
489 			init_special_inode(inode, inode->i_mode, fattr->rdev);
490 
491 		memset(&inode->i_atime, 0, sizeof(inode->i_atime));
492 		memset(&inode->i_mtime, 0, sizeof(inode->i_mtime));
493 		memset(&inode->i_ctime, 0, sizeof(inode->i_ctime));
494 		inode_set_iversion_raw(inode, 0);
495 		inode->i_size = 0;
496 		clear_nlink(inode);
497 		inode->i_uid = make_kuid(&init_user_ns, -2);
498 		inode->i_gid = make_kgid(&init_user_ns, -2);
499 		inode->i_blocks = 0;
500 		memset(nfsi->cookieverf, 0, sizeof(nfsi->cookieverf));
501 		nfsi->write_io = 0;
502 		nfsi->read_io = 0;
503 
504 		nfsi->read_cache_jiffies = fattr->time_start;
505 		nfsi->attr_gencount = fattr->gencount;
506 		if (fattr->valid & NFS_ATTR_FATTR_ATIME)
507 			inode->i_atime = timespec_to_timespec64(fattr->atime);
508 		else if (nfs_server_capable(inode, NFS_CAP_ATIME))
509 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATIME);
510 		if (fattr->valid & NFS_ATTR_FATTR_MTIME)
511 			inode->i_mtime = timespec_to_timespec64(fattr->mtime);
512 		else if (nfs_server_capable(inode, NFS_CAP_MTIME))
513 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_MTIME);
514 		if (fattr->valid & NFS_ATTR_FATTR_CTIME)
515 			inode->i_ctime = timespec_to_timespec64(fattr->ctime);
516 		else if (nfs_server_capable(inode, NFS_CAP_CTIME))
517 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_CTIME);
518 		if (fattr->valid & NFS_ATTR_FATTR_CHANGE)
519 			inode_set_iversion_raw(inode, fattr->change_attr);
520 		else
521 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_CHANGE);
522 		if (fattr->valid & NFS_ATTR_FATTR_SIZE)
523 			inode->i_size = nfs_size_to_loff_t(fattr->size);
524 		else
525 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_SIZE);
526 		if (fattr->valid & NFS_ATTR_FATTR_NLINK)
527 			set_nlink(inode, fattr->nlink);
528 		else if (nfs_server_capable(inode, NFS_CAP_NLINK))
529 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_OTHER);
530 		if (fattr->valid & NFS_ATTR_FATTR_OWNER)
531 			inode->i_uid = fattr->uid;
532 		else if (nfs_server_capable(inode, NFS_CAP_OWNER))
533 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_OTHER);
534 		if (fattr->valid & NFS_ATTR_FATTR_GROUP)
535 			inode->i_gid = fattr->gid;
536 		else if (nfs_server_capable(inode, NFS_CAP_OWNER_GROUP))
537 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_OTHER);
538 		if (fattr->valid & NFS_ATTR_FATTR_BLOCKS_USED)
539 			inode->i_blocks = fattr->du.nfs2.blocks;
540 		if (fattr->valid & NFS_ATTR_FATTR_SPACE_USED) {
541 			/*
542 			 * report the blocks in 512byte units
543 			 */
544 			inode->i_blocks = nfs_calc_block_size(fattr->du.nfs3.used);
545 		}
546 
547 		if (nfsi->cache_validity != 0)
548 			nfsi->cache_validity |= NFS_INO_REVAL_FORCED;
549 
550 		nfs_setsecurity(inode, fattr, label);
551 
552 		nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
553 		nfsi->attrtimeo_timestamp = now;
554 		nfsi->access_cache = RB_ROOT;
555 
556 		nfs_fscache_init_inode(inode);
557 
558 		unlock_new_inode(inode);
559 	} else {
560 		int err = nfs_refresh_inode(inode, fattr);
561 		if (err < 0) {
562 			iput(inode);
563 			inode = ERR_PTR(err);
564 			goto out_no_inode;
565 		}
566 	}
567 	dprintk("NFS: nfs_fhget(%s/%Lu fh_crc=0x%08x ct=%d)\n",
568 		inode->i_sb->s_id,
569 		(unsigned long long)NFS_FILEID(inode),
570 		nfs_display_fhandle_hash(fh),
571 		atomic_read(&inode->i_count));
572 
573 out:
574 	return inode;
575 
576 out_no_inode:
577 	dprintk("nfs_fhget: iget failed with error %ld\n", PTR_ERR(inode));
578 	goto out;
579 }
580 EXPORT_SYMBOL_GPL(nfs_fhget);
581 
582 #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)
583 
584 int
585 nfs_setattr(struct dentry *dentry, struct iattr *attr)
586 {
587 	struct inode *inode = d_inode(dentry);
588 	struct nfs_fattr *fattr;
589 	int error = 0;
590 
591 	nfs_inc_stats(inode, NFSIOS_VFSSETATTR);
592 
593 	/* skip mode change if it's just for clearing setuid/setgid */
594 	if (attr->ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
595 		attr->ia_valid &= ~ATTR_MODE;
596 
597 	if (attr->ia_valid & ATTR_SIZE) {
598 		BUG_ON(!S_ISREG(inode->i_mode));
599 
600 		error = inode_newsize_ok(inode, attr->ia_size);
601 		if (error)
602 			return error;
603 
604 		if (attr->ia_size == i_size_read(inode))
605 			attr->ia_valid &= ~ATTR_SIZE;
606 	}
607 
608 	/* Optimization: if the end result is no change, don't RPC */
609 	attr->ia_valid &= NFS_VALID_ATTRS;
610 	if ((attr->ia_valid & ~(ATTR_FILE|ATTR_OPEN)) == 0)
611 		return 0;
612 
613 	trace_nfs_setattr_enter(inode);
614 
615 	/* Write all dirty data */
616 	if (S_ISREG(inode->i_mode))
617 		nfs_sync_inode(inode);
618 
619 	fattr = nfs_alloc_fattr();
620 	if (fattr == NULL) {
621 		error = -ENOMEM;
622 		goto out;
623 	}
624 
625 	error = NFS_PROTO(inode)->setattr(dentry, fattr, attr);
626 	if (error == 0)
627 		error = nfs_refresh_inode(inode, fattr);
628 	nfs_free_fattr(fattr);
629 out:
630 	trace_nfs_setattr_exit(inode, error);
631 	return error;
632 }
633 EXPORT_SYMBOL_GPL(nfs_setattr);
634 
635 /**
636  * nfs_vmtruncate - unmap mappings "freed" by truncate() syscall
637  * @inode: inode of the file used
638  * @offset: file offset to start truncating
639  *
640  * This is a copy of the common vmtruncate, but with the locking
641  * corrected to take into account the fact that NFS requires
642  * inode->i_size to be updated under the inode->i_lock.
643  * Note: must be called with inode->i_lock held!
644  */
645 static int nfs_vmtruncate(struct inode * inode, loff_t offset)
646 {
647 	int err;
648 
649 	err = inode_newsize_ok(inode, offset);
650 	if (err)
651 		goto out;
652 
653 	i_size_write(inode, offset);
654 	/* Optimisation */
655 	if (offset == 0)
656 		NFS_I(inode)->cache_validity &= ~(NFS_INO_INVALID_DATA |
657 				NFS_INO_DATA_INVAL_DEFER);
658 	NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_SIZE;
659 
660 	spin_unlock(&inode->i_lock);
661 	truncate_pagecache(inode, offset);
662 	spin_lock(&inode->i_lock);
663 out:
664 	return err;
665 }
666 
667 /**
668  * nfs_setattr_update_inode - Update inode metadata after a setattr call.
669  * @inode: pointer to struct inode
670  * @attr: pointer to struct iattr
671  * @fattr: pointer to struct nfs_fattr
672  *
673  * Note: we do this in the *proc.c in order to ensure that
674  *       it works for things like exclusive creates too.
675  */
676 void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr,
677 		struct nfs_fattr *fattr)
678 {
679 	/* Barrier: bump the attribute generation count. */
680 	nfs_fattr_set_barrier(fattr);
681 
682 	spin_lock(&inode->i_lock);
683 	NFS_I(inode)->attr_gencount = fattr->gencount;
684 	if ((attr->ia_valid & ATTR_SIZE) != 0) {
685 		nfs_set_cache_invalid(inode, NFS_INO_INVALID_MTIME);
686 		nfs_inc_stats(inode, NFSIOS_SETATTRTRUNC);
687 		nfs_vmtruncate(inode, attr->ia_size);
688 	}
689 	if ((attr->ia_valid & (ATTR_MODE|ATTR_UID|ATTR_GID)) != 0) {
690 		NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_CTIME;
691 		if ((attr->ia_valid & ATTR_MODE) != 0) {
692 			int mode = attr->ia_mode & S_IALLUGO;
693 			mode |= inode->i_mode & ~S_IALLUGO;
694 			inode->i_mode = mode;
695 		}
696 		if ((attr->ia_valid & ATTR_UID) != 0)
697 			inode->i_uid = attr->ia_uid;
698 		if ((attr->ia_valid & ATTR_GID) != 0)
699 			inode->i_gid = attr->ia_gid;
700 		if (fattr->valid & NFS_ATTR_FATTR_CTIME)
701 			inode->i_ctime = timespec_to_timespec64(fattr->ctime);
702 		else
703 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_CHANGE
704 					| NFS_INO_INVALID_CTIME);
705 		nfs_set_cache_invalid(inode, NFS_INO_INVALID_ACCESS
706 				| NFS_INO_INVALID_ACL);
707 	}
708 	if (attr->ia_valid & (ATTR_ATIME_SET|ATTR_ATIME)) {
709 		NFS_I(inode)->cache_validity &= ~(NFS_INO_INVALID_ATIME
710 				| NFS_INO_INVALID_CTIME);
711 		if (fattr->valid & NFS_ATTR_FATTR_ATIME)
712 			inode->i_atime = timespec_to_timespec64(fattr->atime);
713 		else if (attr->ia_valid & ATTR_ATIME_SET)
714 			inode->i_atime = attr->ia_atime;
715 		else
716 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATIME);
717 
718 		if (fattr->valid & NFS_ATTR_FATTR_CTIME)
719 			inode->i_ctime = timespec_to_timespec64(fattr->ctime);
720 		else
721 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_CHANGE
722 					| NFS_INO_INVALID_CTIME);
723 	}
724 	if (attr->ia_valid & (ATTR_MTIME_SET|ATTR_MTIME)) {
725 		NFS_I(inode)->cache_validity &= ~(NFS_INO_INVALID_MTIME
726 				| NFS_INO_INVALID_CTIME);
727 		if (fattr->valid & NFS_ATTR_FATTR_MTIME)
728 			inode->i_mtime = timespec_to_timespec64(fattr->mtime);
729 		else if (attr->ia_valid & ATTR_MTIME_SET)
730 			inode->i_mtime = attr->ia_mtime;
731 		else
732 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_MTIME);
733 
734 		if (fattr->valid & NFS_ATTR_FATTR_CTIME)
735 			inode->i_ctime = timespec_to_timespec64(fattr->ctime);
736 		else
737 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_CHANGE
738 					| NFS_INO_INVALID_CTIME);
739 	}
740 	if (fattr->valid)
741 		nfs_update_inode(inode, fattr);
742 	spin_unlock(&inode->i_lock);
743 }
744 EXPORT_SYMBOL_GPL(nfs_setattr_update_inode);
745 
746 static void nfs_readdirplus_parent_cache_miss(struct dentry *dentry)
747 {
748 	struct dentry *parent;
749 
750 	if (!nfs_server_capable(d_inode(dentry), NFS_CAP_READDIRPLUS))
751 		return;
752 	parent = dget_parent(dentry);
753 	nfs_force_use_readdirplus(d_inode(parent));
754 	dput(parent);
755 }
756 
757 static void nfs_readdirplus_parent_cache_hit(struct dentry *dentry)
758 {
759 	struct dentry *parent;
760 
761 	if (!nfs_server_capable(d_inode(dentry), NFS_CAP_READDIRPLUS))
762 		return;
763 	parent = dget_parent(dentry);
764 	nfs_advise_use_readdirplus(d_inode(parent));
765 	dput(parent);
766 }
767 
768 static bool nfs_need_revalidate_inode(struct inode *inode)
769 {
770 	if (NFS_I(inode)->cache_validity &
771 			(NFS_INO_INVALID_ATTR|NFS_INO_INVALID_LABEL))
772 		return true;
773 	if (nfs_attribute_cache_expired(inode))
774 		return true;
775 	return false;
776 }
777 
778 int nfs_getattr(const struct path *path, struct kstat *stat,
779 		u32 request_mask, unsigned int query_flags)
780 {
781 	struct inode *inode = d_inode(path->dentry);
782 	struct nfs_server *server = NFS_SERVER(inode);
783 	unsigned long cache_validity;
784 	int err = 0;
785 	bool force_sync = query_flags & AT_STATX_FORCE_SYNC;
786 	bool do_update = false;
787 
788 	trace_nfs_getattr_enter(inode);
789 
790 	if ((query_flags & AT_STATX_DONT_SYNC) && !force_sync)
791 		goto out_no_update;
792 
793 	/* Flush out writes to the server in order to update c/mtime.  */
794 	if ((request_mask & (STATX_CTIME|STATX_MTIME)) &&
795 			S_ISREG(inode->i_mode)) {
796 		err = filemap_write_and_wait(inode->i_mapping);
797 		if (err)
798 			goto out;
799 	}
800 
801 	/*
802 	 * We may force a getattr if the user cares about atime.
803 	 *
804 	 * Note that we only have to check the vfsmount flags here:
805 	 *  - NFS always sets S_NOATIME by so checking it would give a
806 	 *    bogus result
807 	 *  - NFS never sets SB_NOATIME or SB_NODIRATIME so there is
808 	 *    no point in checking those.
809 	 */
810 	if ((path->mnt->mnt_flags & MNT_NOATIME) ||
811 	    ((path->mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode)))
812 		request_mask &= ~STATX_ATIME;
813 
814 	/* Is the user requesting attributes that might need revalidation? */
815 	if (!(request_mask & (STATX_MODE|STATX_NLINK|STATX_ATIME|STATX_CTIME|
816 					STATX_MTIME|STATX_UID|STATX_GID|
817 					STATX_SIZE|STATX_BLOCKS)))
818 		goto out_no_revalidate;
819 
820 	/* Check whether the cached attributes are stale */
821 	do_update |= force_sync || nfs_attribute_cache_expired(inode);
822 	cache_validity = READ_ONCE(NFS_I(inode)->cache_validity);
823 	do_update |= cache_validity &
824 		(NFS_INO_INVALID_ATTR|NFS_INO_INVALID_LABEL);
825 	if (request_mask & STATX_ATIME)
826 		do_update |= cache_validity & NFS_INO_INVALID_ATIME;
827 	if (request_mask & (STATX_CTIME|STATX_MTIME))
828 		do_update |= cache_validity & NFS_INO_REVAL_PAGECACHE;
829 	if (do_update) {
830 		/* Update the attribute cache */
831 		if (!(server->flags & NFS_MOUNT_NOAC))
832 			nfs_readdirplus_parent_cache_miss(path->dentry);
833 		else
834 			nfs_readdirplus_parent_cache_hit(path->dentry);
835 		err = __nfs_revalidate_inode(server, inode);
836 		if (err)
837 			goto out;
838 	} else
839 		nfs_readdirplus_parent_cache_hit(path->dentry);
840 out_no_revalidate:
841 	/* Only return attributes that were revalidated. */
842 	stat->result_mask &= request_mask;
843 out_no_update:
844 	generic_fillattr(inode, stat);
845 	stat->ino = nfs_compat_user_ino64(NFS_FILEID(inode));
846 	if (S_ISDIR(inode->i_mode))
847 		stat->blksize = NFS_SERVER(inode)->dtsize;
848 out:
849 	trace_nfs_getattr_exit(inode, err);
850 	return err;
851 }
852 EXPORT_SYMBOL_GPL(nfs_getattr);
853 
854 static void nfs_init_lock_context(struct nfs_lock_context *l_ctx)
855 {
856 	refcount_set(&l_ctx->count, 1);
857 	l_ctx->lockowner = current->files;
858 	INIT_LIST_HEAD(&l_ctx->list);
859 	atomic_set(&l_ctx->io_count, 0);
860 }
861 
862 static struct nfs_lock_context *__nfs_find_lock_context(struct nfs_open_context *ctx)
863 {
864 	struct nfs_lock_context *pos;
865 
866 	list_for_each_entry_rcu(pos, &ctx->lock_context.list, list) {
867 		if (pos->lockowner != current->files)
868 			continue;
869 		if (refcount_inc_not_zero(&pos->count))
870 			return pos;
871 	}
872 	return NULL;
873 }
874 
875 struct nfs_lock_context *nfs_get_lock_context(struct nfs_open_context *ctx)
876 {
877 	struct nfs_lock_context *res, *new = NULL;
878 	struct inode *inode = d_inode(ctx->dentry);
879 
880 	rcu_read_lock();
881 	res = __nfs_find_lock_context(ctx);
882 	rcu_read_unlock();
883 	if (res == NULL) {
884 		new = kmalloc(sizeof(*new), GFP_KERNEL);
885 		if (new == NULL)
886 			return ERR_PTR(-ENOMEM);
887 		nfs_init_lock_context(new);
888 		spin_lock(&inode->i_lock);
889 		res = __nfs_find_lock_context(ctx);
890 		if (res == NULL) {
891 			new->open_context = get_nfs_open_context(ctx);
892 			if (new->open_context) {
893 				list_add_tail_rcu(&new->list,
894 						&ctx->lock_context.list);
895 				res = new;
896 				new = NULL;
897 			} else
898 				res = ERR_PTR(-EBADF);
899 		}
900 		spin_unlock(&inode->i_lock);
901 		kfree(new);
902 	}
903 	return res;
904 }
905 EXPORT_SYMBOL_GPL(nfs_get_lock_context);
906 
907 void nfs_put_lock_context(struct nfs_lock_context *l_ctx)
908 {
909 	struct nfs_open_context *ctx = l_ctx->open_context;
910 	struct inode *inode = d_inode(ctx->dentry);
911 
912 	if (!refcount_dec_and_lock(&l_ctx->count, &inode->i_lock))
913 		return;
914 	list_del_rcu(&l_ctx->list);
915 	spin_unlock(&inode->i_lock);
916 	put_nfs_open_context(ctx);
917 	kfree_rcu(l_ctx, rcu_head);
918 }
919 EXPORT_SYMBOL_GPL(nfs_put_lock_context);
920 
921 /**
922  * nfs_close_context - Common close_context() routine NFSv2/v3
923  * @ctx: pointer to context
924  * @is_sync: is this a synchronous close
925  *
926  * Ensure that the attributes are up to date if we're mounted
927  * with close-to-open semantics and we have cached data that will
928  * need to be revalidated on open.
929  */
930 void nfs_close_context(struct nfs_open_context *ctx, int is_sync)
931 {
932 	struct nfs_inode *nfsi;
933 	struct inode *inode;
934 	struct nfs_server *server;
935 
936 	if (!(ctx->mode & FMODE_WRITE))
937 		return;
938 	if (!is_sync)
939 		return;
940 	inode = d_inode(ctx->dentry);
941 	if (NFS_PROTO(inode)->have_delegation(inode, FMODE_READ))
942 		return;
943 	nfsi = NFS_I(inode);
944 	if (inode->i_mapping->nrpages == 0)
945 		return;
946 	if (nfsi->cache_validity & NFS_INO_INVALID_DATA)
947 		return;
948 	if (!list_empty(&nfsi->open_files))
949 		return;
950 	server = NFS_SERVER(inode);
951 	if (server->flags & NFS_MOUNT_NOCTO)
952 		return;
953 	nfs_revalidate_inode(server, inode);
954 }
955 EXPORT_SYMBOL_GPL(nfs_close_context);
956 
957 struct nfs_open_context *alloc_nfs_open_context(struct dentry *dentry,
958 						fmode_t f_mode,
959 						struct file *filp)
960 {
961 	struct nfs_open_context *ctx;
962 	const struct cred *cred = get_current_cred();
963 
964 	ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
965 	if (!ctx) {
966 		put_cred(cred);
967 		return ERR_PTR(-ENOMEM);
968 	}
969 	nfs_sb_active(dentry->d_sb);
970 	ctx->dentry = dget(dentry);
971 	ctx->cred = cred;
972 	ctx->ll_cred = NULL;
973 	ctx->state = NULL;
974 	ctx->mode = f_mode;
975 	ctx->flags = 0;
976 	ctx->error = 0;
977 	ctx->flock_owner = (fl_owner_t)filp;
978 	nfs_init_lock_context(&ctx->lock_context);
979 	ctx->lock_context.open_context = ctx;
980 	INIT_LIST_HEAD(&ctx->list);
981 	ctx->mdsthreshold = NULL;
982 	return ctx;
983 }
984 EXPORT_SYMBOL_GPL(alloc_nfs_open_context);
985 
986 struct nfs_open_context *get_nfs_open_context(struct nfs_open_context *ctx)
987 {
988 	if (ctx != NULL && refcount_inc_not_zero(&ctx->lock_context.count))
989 		return ctx;
990 	return NULL;
991 }
992 EXPORT_SYMBOL_GPL(get_nfs_open_context);
993 
994 static void __put_nfs_open_context(struct nfs_open_context *ctx, int is_sync)
995 {
996 	struct inode *inode = d_inode(ctx->dentry);
997 	struct super_block *sb = ctx->dentry->d_sb;
998 
999 	if (!refcount_dec_and_test(&ctx->lock_context.count))
1000 		return;
1001 	if (!list_empty(&ctx->list)) {
1002 		spin_lock(&inode->i_lock);
1003 		list_del_rcu(&ctx->list);
1004 		spin_unlock(&inode->i_lock);
1005 	}
1006 	if (inode != NULL)
1007 		NFS_PROTO(inode)->close_context(ctx, is_sync);
1008 	put_cred(ctx->cred);
1009 	dput(ctx->dentry);
1010 	nfs_sb_deactive(sb);
1011 	put_rpccred(ctx->ll_cred);
1012 	kfree(ctx->mdsthreshold);
1013 	kfree_rcu(ctx, rcu_head);
1014 }
1015 
1016 void put_nfs_open_context(struct nfs_open_context *ctx)
1017 {
1018 	__put_nfs_open_context(ctx, 0);
1019 }
1020 EXPORT_SYMBOL_GPL(put_nfs_open_context);
1021 
1022 static void put_nfs_open_context_sync(struct nfs_open_context *ctx)
1023 {
1024 	__put_nfs_open_context(ctx, 1);
1025 }
1026 
1027 /*
1028  * Ensure that mmap has a recent RPC credential for use when writing out
1029  * shared pages
1030  */
1031 void nfs_inode_attach_open_context(struct nfs_open_context *ctx)
1032 {
1033 	struct inode *inode = d_inode(ctx->dentry);
1034 	struct nfs_inode *nfsi = NFS_I(inode);
1035 
1036 	spin_lock(&inode->i_lock);
1037 	if (list_empty(&nfsi->open_files) &&
1038 	    (nfsi->cache_validity & NFS_INO_DATA_INVAL_DEFER))
1039 		nfsi->cache_validity |= NFS_INO_INVALID_DATA |
1040 			NFS_INO_REVAL_FORCED;
1041 	list_add_tail_rcu(&ctx->list, &nfsi->open_files);
1042 	spin_unlock(&inode->i_lock);
1043 }
1044 EXPORT_SYMBOL_GPL(nfs_inode_attach_open_context);
1045 
1046 void nfs_file_set_open_context(struct file *filp, struct nfs_open_context *ctx)
1047 {
1048 	filp->private_data = get_nfs_open_context(ctx);
1049 	if (list_empty(&ctx->list))
1050 		nfs_inode_attach_open_context(ctx);
1051 }
1052 EXPORT_SYMBOL_GPL(nfs_file_set_open_context);
1053 
1054 /*
1055  * Given an inode, search for an open context with the desired characteristics
1056  */
1057 struct nfs_open_context *nfs_find_open_context(struct inode *inode, const struct cred *cred, fmode_t mode)
1058 {
1059 	struct nfs_inode *nfsi = NFS_I(inode);
1060 	struct nfs_open_context *pos, *ctx = NULL;
1061 
1062 	rcu_read_lock();
1063 	list_for_each_entry_rcu(pos, &nfsi->open_files, list) {
1064 		if (cred != NULL && pos->cred != cred)
1065 			continue;
1066 		if ((pos->mode & (FMODE_READ|FMODE_WRITE)) != mode)
1067 			continue;
1068 		ctx = get_nfs_open_context(pos);
1069 		if (ctx)
1070 			break;
1071 	}
1072 	rcu_read_unlock();
1073 	return ctx;
1074 }
1075 
1076 void nfs_file_clear_open_context(struct file *filp)
1077 {
1078 	struct nfs_open_context *ctx = nfs_file_open_context(filp);
1079 
1080 	if (ctx) {
1081 		struct inode *inode = d_inode(ctx->dentry);
1082 
1083 		/*
1084 		 * We fatal error on write before. Try to writeback
1085 		 * every page again.
1086 		 */
1087 		if (ctx->error < 0)
1088 			invalidate_inode_pages2(inode->i_mapping);
1089 		filp->private_data = NULL;
1090 		put_nfs_open_context_sync(ctx);
1091 	}
1092 }
1093 
1094 /*
1095  * These allocate and release file read/write context information.
1096  */
1097 int nfs_open(struct inode *inode, struct file *filp)
1098 {
1099 	struct nfs_open_context *ctx;
1100 
1101 	ctx = alloc_nfs_open_context(file_dentry(filp), filp->f_mode, filp);
1102 	if (IS_ERR(ctx))
1103 		return PTR_ERR(ctx);
1104 	nfs_file_set_open_context(filp, ctx);
1105 	put_nfs_open_context(ctx);
1106 	nfs_fscache_open_file(inode, filp);
1107 	return 0;
1108 }
1109 EXPORT_SYMBOL_GPL(nfs_open);
1110 
1111 /*
1112  * This function is called whenever some part of NFS notices that
1113  * the cached attributes have to be refreshed.
1114  */
1115 int
1116 __nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
1117 {
1118 	int		 status = -ESTALE;
1119 	struct nfs4_label *label = NULL;
1120 	struct nfs_fattr *fattr = NULL;
1121 	struct nfs_inode *nfsi = NFS_I(inode);
1122 
1123 	dfprintk(PAGECACHE, "NFS: revalidating (%s/%Lu)\n",
1124 		inode->i_sb->s_id, (unsigned long long)NFS_FILEID(inode));
1125 
1126 	trace_nfs_revalidate_inode_enter(inode);
1127 
1128 	if (is_bad_inode(inode))
1129 		goto out;
1130 	if (NFS_STALE(inode))
1131 		goto out;
1132 
1133 	/* pNFS: Attributes aren't updated until we layoutcommit */
1134 	if (S_ISREG(inode->i_mode)) {
1135 		status = pnfs_sync_inode(inode, false);
1136 		if (status)
1137 			goto out;
1138 	}
1139 
1140 	status = -ENOMEM;
1141 	fattr = nfs_alloc_fattr();
1142 	if (fattr == NULL)
1143 		goto out;
1144 
1145 	nfs_inc_stats(inode, NFSIOS_INODEREVALIDATE);
1146 
1147 	label = nfs4_label_alloc(NFS_SERVER(inode), GFP_KERNEL);
1148 	if (IS_ERR(label)) {
1149 		status = PTR_ERR(label);
1150 		goto out;
1151 	}
1152 
1153 	status = NFS_PROTO(inode)->getattr(server, NFS_FH(inode), fattr,
1154 			label, inode);
1155 	if (status != 0) {
1156 		dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Lu) getattr failed, error=%d\n",
1157 			 inode->i_sb->s_id,
1158 			 (unsigned long long)NFS_FILEID(inode), status);
1159 		if (status == -ESTALE) {
1160 			nfs_zap_caches(inode);
1161 			if (!S_ISDIR(inode->i_mode))
1162 				set_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
1163 		}
1164 		goto err_out;
1165 	}
1166 
1167 	status = nfs_refresh_inode(inode, fattr);
1168 	if (status) {
1169 		dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Lu) refresh failed, error=%d\n",
1170 			 inode->i_sb->s_id,
1171 			 (unsigned long long)NFS_FILEID(inode), status);
1172 		goto err_out;
1173 	}
1174 
1175 	if (nfsi->cache_validity & NFS_INO_INVALID_ACL)
1176 		nfs_zap_acl_cache(inode);
1177 
1178 	nfs_setsecurity(inode, fattr, label);
1179 
1180 	dfprintk(PAGECACHE, "NFS: (%s/%Lu) revalidation complete\n",
1181 		inode->i_sb->s_id,
1182 		(unsigned long long)NFS_FILEID(inode));
1183 
1184 err_out:
1185 	nfs4_label_free(label);
1186 out:
1187 	nfs_free_fattr(fattr);
1188 	trace_nfs_revalidate_inode_exit(inode, status);
1189 	return status;
1190 }
1191 
1192 int nfs_attribute_cache_expired(struct inode *inode)
1193 {
1194 	if (nfs_have_delegated_attributes(inode))
1195 		return 0;
1196 	return nfs_attribute_timeout(inode);
1197 }
1198 
1199 /**
1200  * nfs_revalidate_inode - Revalidate the inode attributes
1201  * @server: pointer to nfs_server struct
1202  * @inode: pointer to inode struct
1203  *
1204  * Updates inode attribute information by retrieving the data from the server.
1205  */
1206 int nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
1207 {
1208 	if (!nfs_need_revalidate_inode(inode))
1209 		return NFS_STALE(inode) ? -ESTALE : 0;
1210 	return __nfs_revalidate_inode(server, inode);
1211 }
1212 EXPORT_SYMBOL_GPL(nfs_revalidate_inode);
1213 
1214 static int nfs_invalidate_mapping(struct inode *inode, struct address_space *mapping)
1215 {
1216 	struct nfs_inode *nfsi = NFS_I(inode);
1217 	int ret;
1218 
1219 	if (mapping->nrpages != 0) {
1220 		if (S_ISREG(inode->i_mode)) {
1221 			ret = nfs_sync_mapping(mapping);
1222 			if (ret < 0)
1223 				return ret;
1224 		}
1225 		ret = invalidate_inode_pages2(mapping);
1226 		if (ret < 0)
1227 			return ret;
1228 	}
1229 	if (S_ISDIR(inode->i_mode)) {
1230 		spin_lock(&inode->i_lock);
1231 		memset(nfsi->cookieverf, 0, sizeof(nfsi->cookieverf));
1232 		spin_unlock(&inode->i_lock);
1233 	}
1234 	nfs_inc_stats(inode, NFSIOS_DATAINVALIDATE);
1235 	nfs_fscache_wait_on_invalidate(inode);
1236 
1237 	dfprintk(PAGECACHE, "NFS: (%s/%Lu) data cache invalidated\n",
1238 			inode->i_sb->s_id,
1239 			(unsigned long long)NFS_FILEID(inode));
1240 	return 0;
1241 }
1242 
1243 bool nfs_mapping_need_revalidate_inode(struct inode *inode)
1244 {
1245 	return nfs_check_cache_invalid(inode, NFS_INO_REVAL_PAGECACHE) ||
1246 		NFS_STALE(inode);
1247 }
1248 
1249 int nfs_revalidate_mapping_rcu(struct inode *inode)
1250 {
1251 	struct nfs_inode *nfsi = NFS_I(inode);
1252 	unsigned long *bitlock = &nfsi->flags;
1253 	int ret = 0;
1254 
1255 	if (IS_SWAPFILE(inode))
1256 		goto out;
1257 	if (nfs_mapping_need_revalidate_inode(inode)) {
1258 		ret = -ECHILD;
1259 		goto out;
1260 	}
1261 	spin_lock(&inode->i_lock);
1262 	if (test_bit(NFS_INO_INVALIDATING, bitlock) ||
1263 	    (nfsi->cache_validity & NFS_INO_INVALID_DATA))
1264 		ret = -ECHILD;
1265 	spin_unlock(&inode->i_lock);
1266 out:
1267 	return ret;
1268 }
1269 
1270 /**
1271  * nfs_revalidate_mapping - Revalidate the pagecache
1272  * @inode: pointer to host inode
1273  * @mapping: pointer to mapping
1274  */
1275 int nfs_revalidate_mapping(struct inode *inode,
1276 		struct address_space *mapping)
1277 {
1278 	struct nfs_inode *nfsi = NFS_I(inode);
1279 	unsigned long *bitlock = &nfsi->flags;
1280 	int ret = 0;
1281 
1282 	/* swapfiles are not supposed to be shared. */
1283 	if (IS_SWAPFILE(inode))
1284 		goto out;
1285 
1286 	if (nfs_mapping_need_revalidate_inode(inode)) {
1287 		ret = __nfs_revalidate_inode(NFS_SERVER(inode), inode);
1288 		if (ret < 0)
1289 			goto out;
1290 	}
1291 
1292 	/*
1293 	 * We must clear NFS_INO_INVALID_DATA first to ensure that
1294 	 * invalidations that come in while we're shooting down the mappings
1295 	 * are respected. But, that leaves a race window where one revalidator
1296 	 * can clear the flag, and then another checks it before the mapping
1297 	 * gets invalidated. Fix that by serializing access to this part of
1298 	 * the function.
1299 	 *
1300 	 * At the same time, we need to allow other tasks to see whether we
1301 	 * might be in the middle of invalidating the pages, so we only set
1302 	 * the bit lock here if it looks like we're going to be doing that.
1303 	 */
1304 	for (;;) {
1305 		ret = wait_on_bit_action(bitlock, NFS_INO_INVALIDATING,
1306 					 nfs_wait_bit_killable, TASK_KILLABLE);
1307 		if (ret)
1308 			goto out;
1309 		spin_lock(&inode->i_lock);
1310 		if (test_bit(NFS_INO_INVALIDATING, bitlock)) {
1311 			spin_unlock(&inode->i_lock);
1312 			continue;
1313 		}
1314 		if (nfsi->cache_validity & NFS_INO_INVALID_DATA)
1315 			break;
1316 		spin_unlock(&inode->i_lock);
1317 		goto out;
1318 	}
1319 
1320 	set_bit(NFS_INO_INVALIDATING, bitlock);
1321 	smp_wmb();
1322 	nfsi->cache_validity &= ~(NFS_INO_INVALID_DATA|
1323 			NFS_INO_DATA_INVAL_DEFER);
1324 	spin_unlock(&inode->i_lock);
1325 	trace_nfs_invalidate_mapping_enter(inode);
1326 	ret = nfs_invalidate_mapping(inode, mapping);
1327 	trace_nfs_invalidate_mapping_exit(inode, ret);
1328 
1329 	clear_bit_unlock(NFS_INO_INVALIDATING, bitlock);
1330 	smp_mb__after_atomic();
1331 	wake_up_bit(bitlock, NFS_INO_INVALIDATING);
1332 out:
1333 	return ret;
1334 }
1335 
1336 static bool nfs_file_has_writers(struct nfs_inode *nfsi)
1337 {
1338 	struct inode *inode = &nfsi->vfs_inode;
1339 
1340 	if (!S_ISREG(inode->i_mode))
1341 		return false;
1342 	if (list_empty(&nfsi->open_files))
1343 		return false;
1344 	return inode_is_open_for_write(inode);
1345 }
1346 
1347 static bool nfs_file_has_buffered_writers(struct nfs_inode *nfsi)
1348 {
1349 	return nfs_file_has_writers(nfsi) && nfs_file_io_is_buffered(nfsi);
1350 }
1351 
1352 static void nfs_wcc_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1353 {
1354 	struct timespec ts;
1355 
1356 	if ((fattr->valid & NFS_ATTR_FATTR_PRECHANGE)
1357 			&& (fattr->valid & NFS_ATTR_FATTR_CHANGE)
1358 			&& inode_eq_iversion_raw(inode, fattr->pre_change_attr)) {
1359 		inode_set_iversion_raw(inode, fattr->change_attr);
1360 		if (S_ISDIR(inode->i_mode))
1361 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_DATA);
1362 	}
1363 	/* If we have atomic WCC data, we may update some attributes */
1364 	ts = timespec64_to_timespec(inode->i_ctime);
1365 	if ((fattr->valid & NFS_ATTR_FATTR_PRECTIME)
1366 			&& (fattr->valid & NFS_ATTR_FATTR_CTIME)
1367 			&& timespec_equal(&ts, &fattr->pre_ctime)) {
1368 		inode->i_ctime = timespec_to_timespec64(fattr->ctime);
1369 	}
1370 
1371 	ts = timespec64_to_timespec(inode->i_mtime);
1372 	if ((fattr->valid & NFS_ATTR_FATTR_PREMTIME)
1373 			&& (fattr->valid & NFS_ATTR_FATTR_MTIME)
1374 			&& timespec_equal(&ts, &fattr->pre_mtime)) {
1375 		inode->i_mtime = timespec_to_timespec64(fattr->mtime);
1376 		if (S_ISDIR(inode->i_mode))
1377 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_DATA);
1378 	}
1379 	if ((fattr->valid & NFS_ATTR_FATTR_PRESIZE)
1380 			&& (fattr->valid & NFS_ATTR_FATTR_SIZE)
1381 			&& i_size_read(inode) == nfs_size_to_loff_t(fattr->pre_size)
1382 			&& !nfs_have_writebacks(inode)) {
1383 		i_size_write(inode, nfs_size_to_loff_t(fattr->size));
1384 	}
1385 }
1386 
1387 /**
1388  * nfs_check_inode_attributes - verify consistency of the inode attribute cache
1389  * @inode: pointer to inode
1390  * @fattr: updated attributes
1391  *
1392  * Verifies the attribute cache. If we have just changed the attributes,
1393  * so that fattr carries weak cache consistency data, then it may
1394  * also update the ctime/mtime/change_attribute.
1395  */
1396 static int nfs_check_inode_attributes(struct inode *inode, struct nfs_fattr *fattr)
1397 {
1398 	struct nfs_inode *nfsi = NFS_I(inode);
1399 	loff_t cur_size, new_isize;
1400 	unsigned long invalid = 0;
1401 	struct timespec ts;
1402 
1403 	if (NFS_PROTO(inode)->have_delegation(inode, FMODE_READ))
1404 		return 0;
1405 
1406 	if (!(fattr->valid & NFS_ATTR_FATTR_FILEID)) {
1407 		/* Only a mounted-on-fileid? Just exit */
1408 		if (fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID)
1409 			return 0;
1410 	/* Has the inode gone and changed behind our back? */
1411 	} else if (nfsi->fileid != fattr->fileid) {
1412 		/* Is this perhaps the mounted-on fileid? */
1413 		if ((fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID) &&
1414 		    nfsi->fileid == fattr->mounted_on_fileid)
1415 			return 0;
1416 		return -ESTALE;
1417 	}
1418 	if ((fattr->valid & NFS_ATTR_FATTR_TYPE) && (inode->i_mode & S_IFMT) != (fattr->mode & S_IFMT))
1419 		return -ESTALE;
1420 
1421 
1422 	if (!nfs_file_has_buffered_writers(nfsi)) {
1423 		/* Verify a few of the more important attributes */
1424 		if ((fattr->valid & NFS_ATTR_FATTR_CHANGE) != 0 && !inode_eq_iversion_raw(inode, fattr->change_attr))
1425 			invalid |= NFS_INO_INVALID_CHANGE
1426 				| NFS_INO_REVAL_PAGECACHE;
1427 
1428 		ts = timespec64_to_timespec(inode->i_mtime);
1429 		if ((fattr->valid & NFS_ATTR_FATTR_MTIME) && !timespec_equal(&ts, &fattr->mtime))
1430 			invalid |= NFS_INO_INVALID_MTIME;
1431 
1432 		ts = timespec64_to_timespec(inode->i_ctime);
1433 		if ((fattr->valid & NFS_ATTR_FATTR_CTIME) && !timespec_equal(&ts, &fattr->ctime))
1434 			invalid |= NFS_INO_INVALID_CTIME;
1435 
1436 		if (fattr->valid & NFS_ATTR_FATTR_SIZE) {
1437 			cur_size = i_size_read(inode);
1438 			new_isize = nfs_size_to_loff_t(fattr->size);
1439 			if (cur_size != new_isize)
1440 				invalid |= NFS_INO_INVALID_SIZE
1441 					| NFS_INO_REVAL_PAGECACHE;
1442 		}
1443 	}
1444 
1445 	/* Have any file permissions changed? */
1446 	if ((fattr->valid & NFS_ATTR_FATTR_MODE) && (inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO))
1447 		invalid |= NFS_INO_INVALID_ACCESS
1448 			| NFS_INO_INVALID_ACL
1449 			| NFS_INO_INVALID_OTHER;
1450 	if ((fattr->valid & NFS_ATTR_FATTR_OWNER) && !uid_eq(inode->i_uid, fattr->uid))
1451 		invalid |= NFS_INO_INVALID_ACCESS
1452 			| NFS_INO_INVALID_ACL
1453 			| NFS_INO_INVALID_OTHER;
1454 	if ((fattr->valid & NFS_ATTR_FATTR_GROUP) && !gid_eq(inode->i_gid, fattr->gid))
1455 		invalid |= NFS_INO_INVALID_ACCESS
1456 			| NFS_INO_INVALID_ACL
1457 			| NFS_INO_INVALID_OTHER;
1458 
1459 	/* Has the link count changed? */
1460 	if ((fattr->valid & NFS_ATTR_FATTR_NLINK) && inode->i_nlink != fattr->nlink)
1461 		invalid |= NFS_INO_INVALID_OTHER;
1462 
1463 	ts = timespec64_to_timespec(inode->i_atime);
1464 	if ((fattr->valid & NFS_ATTR_FATTR_ATIME) && !timespec_equal(&ts, &fattr->atime))
1465 		invalid |= NFS_INO_INVALID_ATIME;
1466 
1467 	if (invalid != 0)
1468 		nfs_set_cache_invalid(inode, invalid);
1469 
1470 	nfsi->read_cache_jiffies = fattr->time_start;
1471 	return 0;
1472 }
1473 
1474 static atomic_long_t nfs_attr_generation_counter;
1475 
1476 static unsigned long nfs_read_attr_generation_counter(void)
1477 {
1478 	return atomic_long_read(&nfs_attr_generation_counter);
1479 }
1480 
1481 unsigned long nfs_inc_attr_generation_counter(void)
1482 {
1483 	return atomic_long_inc_return(&nfs_attr_generation_counter);
1484 }
1485 EXPORT_SYMBOL_GPL(nfs_inc_attr_generation_counter);
1486 
1487 void nfs_fattr_init(struct nfs_fattr *fattr)
1488 {
1489 	fattr->valid = 0;
1490 	fattr->time_start = jiffies;
1491 	fattr->gencount = nfs_inc_attr_generation_counter();
1492 	fattr->owner_name = NULL;
1493 	fattr->group_name = NULL;
1494 }
1495 EXPORT_SYMBOL_GPL(nfs_fattr_init);
1496 
1497 /**
1498  * nfs_fattr_set_barrier
1499  * @fattr: attributes
1500  *
1501  * Used to set a barrier after an attribute was updated. This
1502  * barrier ensures that older attributes from RPC calls that may
1503  * have raced with our update cannot clobber these new values.
1504  * Note that you are still responsible for ensuring that other
1505  * operations which change the attribute on the server do not
1506  * collide.
1507  */
1508 void nfs_fattr_set_barrier(struct nfs_fattr *fattr)
1509 {
1510 	fattr->gencount = nfs_inc_attr_generation_counter();
1511 }
1512 
1513 struct nfs_fattr *nfs_alloc_fattr(void)
1514 {
1515 	struct nfs_fattr *fattr;
1516 
1517 	fattr = kmalloc(sizeof(*fattr), GFP_NOFS);
1518 	if (fattr != NULL)
1519 		nfs_fattr_init(fattr);
1520 	return fattr;
1521 }
1522 EXPORT_SYMBOL_GPL(nfs_alloc_fattr);
1523 
1524 struct nfs_fh *nfs_alloc_fhandle(void)
1525 {
1526 	struct nfs_fh *fh;
1527 
1528 	fh = kmalloc(sizeof(struct nfs_fh), GFP_NOFS);
1529 	if (fh != NULL)
1530 		fh->size = 0;
1531 	return fh;
1532 }
1533 EXPORT_SYMBOL_GPL(nfs_alloc_fhandle);
1534 
1535 #ifdef NFS_DEBUG
1536 /*
1537  * _nfs_display_fhandle_hash - calculate the crc32 hash for the filehandle
1538  *                             in the same way that wireshark does
1539  *
1540  * @fh: file handle
1541  *
1542  * For debugging only.
1543  */
1544 u32 _nfs_display_fhandle_hash(const struct nfs_fh *fh)
1545 {
1546 	/* wireshark uses 32-bit AUTODIN crc and does a bitwise
1547 	 * not on the result */
1548 	return nfs_fhandle_hash(fh);
1549 }
1550 EXPORT_SYMBOL_GPL(_nfs_display_fhandle_hash);
1551 
1552 /*
1553  * _nfs_display_fhandle - display an NFS file handle on the console
1554  *
1555  * @fh: file handle to display
1556  * @caption: display caption
1557  *
1558  * For debugging only.
1559  */
1560 void _nfs_display_fhandle(const struct nfs_fh *fh, const char *caption)
1561 {
1562 	unsigned short i;
1563 
1564 	if (fh == NULL || fh->size == 0) {
1565 		printk(KERN_DEFAULT "%s at %p is empty\n", caption, fh);
1566 		return;
1567 	}
1568 
1569 	printk(KERN_DEFAULT "%s at %p is %u bytes, crc: 0x%08x:\n",
1570 	       caption, fh, fh->size, _nfs_display_fhandle_hash(fh));
1571 	for (i = 0; i < fh->size; i += 16) {
1572 		__be32 *pos = (__be32 *)&fh->data[i];
1573 
1574 		switch ((fh->size - i - 1) >> 2) {
1575 		case 0:
1576 			printk(KERN_DEFAULT " %08x\n",
1577 				be32_to_cpup(pos));
1578 			break;
1579 		case 1:
1580 			printk(KERN_DEFAULT " %08x %08x\n",
1581 				be32_to_cpup(pos), be32_to_cpup(pos + 1));
1582 			break;
1583 		case 2:
1584 			printk(KERN_DEFAULT " %08x %08x %08x\n",
1585 				be32_to_cpup(pos), be32_to_cpup(pos + 1),
1586 				be32_to_cpup(pos + 2));
1587 			break;
1588 		default:
1589 			printk(KERN_DEFAULT " %08x %08x %08x %08x\n",
1590 				be32_to_cpup(pos), be32_to_cpup(pos + 1),
1591 				be32_to_cpup(pos + 2), be32_to_cpup(pos + 3));
1592 		}
1593 	}
1594 }
1595 EXPORT_SYMBOL_GPL(_nfs_display_fhandle);
1596 #endif
1597 
1598 /**
1599  * nfs_inode_attrs_need_update - check if the inode attributes need updating
1600  * @inode: pointer to inode
1601  * @fattr: attributes
1602  *
1603  * Attempt to divine whether or not an RPC call reply carrying stale
1604  * attributes got scheduled after another call carrying updated ones.
1605  *
1606  * To do so, the function first assumes that a more recent ctime means
1607  * that the attributes in fattr are newer, however it also attempt to
1608  * catch the case where ctime either didn't change, or went backwards
1609  * (if someone reset the clock on the server) by looking at whether
1610  * or not this RPC call was started after the inode was last updated.
1611  * Note also the check for wraparound of 'attr_gencount'
1612  *
1613  * The function returns 'true' if it thinks the attributes in 'fattr' are
1614  * more recent than the ones cached in the inode.
1615  *
1616  */
1617 static int nfs_inode_attrs_need_update(const struct inode *inode, const struct nfs_fattr *fattr)
1618 {
1619 	const struct nfs_inode *nfsi = NFS_I(inode);
1620 
1621 	return ((long)fattr->gencount - (long)nfsi->attr_gencount) > 0 ||
1622 		((long)nfsi->attr_gencount - (long)nfs_read_attr_generation_counter() > 0);
1623 }
1624 
1625 static int nfs_refresh_inode_locked(struct inode *inode, struct nfs_fattr *fattr)
1626 {
1627 	int ret;
1628 
1629 	trace_nfs_refresh_inode_enter(inode);
1630 
1631 	if (nfs_inode_attrs_need_update(inode, fattr))
1632 		ret = nfs_update_inode(inode, fattr);
1633 	else
1634 		ret = nfs_check_inode_attributes(inode, fattr);
1635 
1636 	trace_nfs_refresh_inode_exit(inode, ret);
1637 	return ret;
1638 }
1639 
1640 /**
1641  * nfs_refresh_inode - try to update the inode attribute cache
1642  * @inode: pointer to inode
1643  * @fattr: updated attributes
1644  *
1645  * Check that an RPC call that returned attributes has not overlapped with
1646  * other recent updates of the inode metadata, then decide whether it is
1647  * safe to do a full update of the inode attributes, or whether just to
1648  * call nfs_check_inode_attributes.
1649  */
1650 int nfs_refresh_inode(struct inode *inode, struct nfs_fattr *fattr)
1651 {
1652 	int status;
1653 
1654 	if ((fattr->valid & NFS_ATTR_FATTR) == 0)
1655 		return 0;
1656 	spin_lock(&inode->i_lock);
1657 	status = nfs_refresh_inode_locked(inode, fattr);
1658 	spin_unlock(&inode->i_lock);
1659 
1660 	return status;
1661 }
1662 EXPORT_SYMBOL_GPL(nfs_refresh_inode);
1663 
1664 static int nfs_post_op_update_inode_locked(struct inode *inode,
1665 		struct nfs_fattr *fattr, unsigned int invalid)
1666 {
1667 	if (S_ISDIR(inode->i_mode))
1668 		invalid |= NFS_INO_INVALID_DATA;
1669 	nfs_set_cache_invalid(inode, invalid);
1670 	if ((fattr->valid & NFS_ATTR_FATTR) == 0)
1671 		return 0;
1672 	return nfs_refresh_inode_locked(inode, fattr);
1673 }
1674 
1675 /**
1676  * nfs_post_op_update_inode - try to update the inode attribute cache
1677  * @inode: pointer to inode
1678  * @fattr: updated attributes
1679  *
1680  * After an operation that has changed the inode metadata, mark the
1681  * attribute cache as being invalid, then try to update it.
1682  *
1683  * NB: if the server didn't return any post op attributes, this
1684  * function will force the retrieval of attributes before the next
1685  * NFS request.  Thus it should be used only for operations that
1686  * are expected to change one or more attributes, to avoid
1687  * unnecessary NFS requests and trips through nfs_update_inode().
1688  */
1689 int nfs_post_op_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1690 {
1691 	int status;
1692 
1693 	spin_lock(&inode->i_lock);
1694 	nfs_fattr_set_barrier(fattr);
1695 	status = nfs_post_op_update_inode_locked(inode, fattr,
1696 			NFS_INO_INVALID_CHANGE
1697 			| NFS_INO_INVALID_CTIME
1698 			| NFS_INO_REVAL_FORCED);
1699 	spin_unlock(&inode->i_lock);
1700 
1701 	return status;
1702 }
1703 EXPORT_SYMBOL_GPL(nfs_post_op_update_inode);
1704 
1705 /**
1706  * nfs_post_op_update_inode_force_wcc_locked - update the inode attribute cache
1707  * @inode: pointer to inode
1708  * @fattr: updated attributes
1709  *
1710  * After an operation that has changed the inode metadata, mark the
1711  * attribute cache as being invalid, then try to update it. Fake up
1712  * weak cache consistency data, if none exist.
1713  *
1714  * This function is mainly designed to be used by the ->write_done() functions.
1715  */
1716 int nfs_post_op_update_inode_force_wcc_locked(struct inode *inode, struct nfs_fattr *fattr)
1717 {
1718 	int status;
1719 
1720 	/* Don't do a WCC update if these attributes are already stale */
1721 	if ((fattr->valid & NFS_ATTR_FATTR) == 0 ||
1722 			!nfs_inode_attrs_need_update(inode, fattr)) {
1723 		fattr->valid &= ~(NFS_ATTR_FATTR_PRECHANGE
1724 				| NFS_ATTR_FATTR_PRESIZE
1725 				| NFS_ATTR_FATTR_PREMTIME
1726 				| NFS_ATTR_FATTR_PRECTIME);
1727 		goto out_noforce;
1728 	}
1729 	if ((fattr->valid & NFS_ATTR_FATTR_CHANGE) != 0 &&
1730 			(fattr->valid & NFS_ATTR_FATTR_PRECHANGE) == 0) {
1731 		fattr->pre_change_attr = inode_peek_iversion_raw(inode);
1732 		fattr->valid |= NFS_ATTR_FATTR_PRECHANGE;
1733 	}
1734 	if ((fattr->valid & NFS_ATTR_FATTR_CTIME) != 0 &&
1735 			(fattr->valid & NFS_ATTR_FATTR_PRECTIME) == 0) {
1736 		fattr->pre_ctime = timespec64_to_timespec(inode->i_ctime);
1737 		fattr->valid |= NFS_ATTR_FATTR_PRECTIME;
1738 	}
1739 	if ((fattr->valid & NFS_ATTR_FATTR_MTIME) != 0 &&
1740 			(fattr->valid & NFS_ATTR_FATTR_PREMTIME) == 0) {
1741 		fattr->pre_mtime = timespec64_to_timespec(inode->i_mtime);
1742 		fattr->valid |= NFS_ATTR_FATTR_PREMTIME;
1743 	}
1744 	if ((fattr->valid & NFS_ATTR_FATTR_SIZE) != 0 &&
1745 			(fattr->valid & NFS_ATTR_FATTR_PRESIZE) == 0) {
1746 		fattr->pre_size = i_size_read(inode);
1747 		fattr->valid |= NFS_ATTR_FATTR_PRESIZE;
1748 	}
1749 out_noforce:
1750 	status = nfs_post_op_update_inode_locked(inode, fattr,
1751 			NFS_INO_INVALID_CHANGE
1752 			| NFS_INO_INVALID_CTIME
1753 			| NFS_INO_INVALID_MTIME);
1754 	return status;
1755 }
1756 
1757 /**
1758  * nfs_post_op_update_inode_force_wcc - try to update the inode attribute cache
1759  * @inode: pointer to inode
1760  * @fattr: updated attributes
1761  *
1762  * After an operation that has changed the inode metadata, mark the
1763  * attribute cache as being invalid, then try to update it. Fake up
1764  * weak cache consistency data, if none exist.
1765  *
1766  * This function is mainly designed to be used by the ->write_done() functions.
1767  */
1768 int nfs_post_op_update_inode_force_wcc(struct inode *inode, struct nfs_fattr *fattr)
1769 {
1770 	int status;
1771 
1772 	spin_lock(&inode->i_lock);
1773 	nfs_fattr_set_barrier(fattr);
1774 	status = nfs_post_op_update_inode_force_wcc_locked(inode, fattr);
1775 	spin_unlock(&inode->i_lock);
1776 	return status;
1777 }
1778 EXPORT_SYMBOL_GPL(nfs_post_op_update_inode_force_wcc);
1779 
1780 
1781 /*
1782  * Many nfs protocol calls return the new file attributes after
1783  * an operation.  Here we update the inode to reflect the state
1784  * of the server's inode.
1785  *
1786  * This is a bit tricky because we have to make sure all dirty pages
1787  * have been sent off to the server before calling invalidate_inode_pages.
1788  * To make sure no other process adds more write requests while we try
1789  * our best to flush them, we make them sleep during the attribute refresh.
1790  *
1791  * A very similar scenario holds for the dir cache.
1792  */
1793 static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1794 {
1795 	struct nfs_server *server;
1796 	struct nfs_inode *nfsi = NFS_I(inode);
1797 	loff_t cur_isize, new_isize;
1798 	unsigned long invalid = 0;
1799 	unsigned long now = jiffies;
1800 	unsigned long save_cache_validity;
1801 	bool have_writers = nfs_file_has_buffered_writers(nfsi);
1802 	bool cache_revalidated = true;
1803 	bool attr_changed = false;
1804 	bool have_delegation;
1805 
1806 	dfprintk(VFS, "NFS: %s(%s/%lu fh_crc=0x%08x ct=%d info=0x%x)\n",
1807 			__func__, inode->i_sb->s_id, inode->i_ino,
1808 			nfs_display_fhandle_hash(NFS_FH(inode)),
1809 			atomic_read(&inode->i_count), fattr->valid);
1810 
1811 	if (!(fattr->valid & NFS_ATTR_FATTR_FILEID)) {
1812 		/* Only a mounted-on-fileid? Just exit */
1813 		if (fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID)
1814 			return 0;
1815 	/* Has the inode gone and changed behind our back? */
1816 	} else if (nfsi->fileid != fattr->fileid) {
1817 		/* Is this perhaps the mounted-on fileid? */
1818 		if ((fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID) &&
1819 		    nfsi->fileid == fattr->mounted_on_fileid)
1820 			return 0;
1821 		printk(KERN_ERR "NFS: server %s error: fileid changed\n"
1822 			"fsid %s: expected fileid 0x%Lx, got 0x%Lx\n",
1823 			NFS_SERVER(inode)->nfs_client->cl_hostname,
1824 			inode->i_sb->s_id, (long long)nfsi->fileid,
1825 			(long long)fattr->fileid);
1826 		goto out_err;
1827 	}
1828 
1829 	/*
1830 	 * Make sure the inode's type hasn't changed.
1831 	 */
1832 	if ((fattr->valid & NFS_ATTR_FATTR_TYPE) && (inode->i_mode & S_IFMT) != (fattr->mode & S_IFMT)) {
1833 		/*
1834 		* Big trouble! The inode has become a different object.
1835 		*/
1836 		printk(KERN_DEBUG "NFS: %s: inode %lu mode changed, %07o to %07o\n",
1837 				__func__, inode->i_ino, inode->i_mode, fattr->mode);
1838 		goto out_err;
1839 	}
1840 
1841 	server = NFS_SERVER(inode);
1842 	/* Update the fsid? */
1843 	if (S_ISDIR(inode->i_mode) && (fattr->valid & NFS_ATTR_FATTR_FSID) &&
1844 			!nfs_fsid_equal(&server->fsid, &fattr->fsid) &&
1845 			!IS_AUTOMOUNT(inode))
1846 		server->fsid = fattr->fsid;
1847 
1848 	/* Save the delegation state before clearing cache_validity */
1849 	have_delegation = nfs_have_delegated_attributes(inode);
1850 
1851 	/*
1852 	 * Update the read time so we don't revalidate too often.
1853 	 */
1854 	nfsi->read_cache_jiffies = fattr->time_start;
1855 
1856 	save_cache_validity = nfsi->cache_validity;
1857 	nfsi->cache_validity &= ~(NFS_INO_INVALID_ATTR
1858 			| NFS_INO_INVALID_ATIME
1859 			| NFS_INO_REVAL_FORCED
1860 			| NFS_INO_REVAL_PAGECACHE);
1861 
1862 	/* Do atomic weak cache consistency updates */
1863 	nfs_wcc_update_inode(inode, fattr);
1864 
1865 	if (pnfs_layoutcommit_outstanding(inode)) {
1866 		nfsi->cache_validity |= save_cache_validity & NFS_INO_INVALID_ATTR;
1867 		cache_revalidated = false;
1868 	}
1869 
1870 	/* More cache consistency checks */
1871 	if (fattr->valid & NFS_ATTR_FATTR_CHANGE) {
1872 		if (!inode_eq_iversion_raw(inode, fattr->change_attr)) {
1873 			/* Could it be a race with writeback? */
1874 			if (!(have_writers || have_delegation)) {
1875 				invalid |= NFS_INO_INVALID_DATA
1876 					| NFS_INO_INVALID_ACCESS
1877 					| NFS_INO_INVALID_ACL;
1878 				/* Force revalidate of all attributes */
1879 				save_cache_validity |= NFS_INO_INVALID_CTIME
1880 					| NFS_INO_INVALID_MTIME
1881 					| NFS_INO_INVALID_SIZE
1882 					| NFS_INO_INVALID_OTHER;
1883 				if (S_ISDIR(inode->i_mode))
1884 					nfs_force_lookup_revalidate(inode);
1885 				dprintk("NFS: change_attr change on server for file %s/%ld\n",
1886 						inode->i_sb->s_id,
1887 						inode->i_ino);
1888 			} else if (!have_delegation)
1889 				nfsi->cache_validity |= NFS_INO_DATA_INVAL_DEFER;
1890 			inode_set_iversion_raw(inode, fattr->change_attr);
1891 			attr_changed = true;
1892 		}
1893 	} else {
1894 		nfsi->cache_validity |= save_cache_validity &
1895 				(NFS_INO_INVALID_CHANGE
1896 				| NFS_INO_REVAL_PAGECACHE
1897 				| NFS_INO_REVAL_FORCED);
1898 		cache_revalidated = false;
1899 	}
1900 
1901 	if (fattr->valid & NFS_ATTR_FATTR_MTIME) {
1902 		inode->i_mtime = timespec_to_timespec64(fattr->mtime);
1903 	} else if (server->caps & NFS_CAP_MTIME) {
1904 		nfsi->cache_validity |= save_cache_validity &
1905 				(NFS_INO_INVALID_MTIME
1906 				| NFS_INO_REVAL_FORCED);
1907 		cache_revalidated = false;
1908 	}
1909 
1910 	if (fattr->valid & NFS_ATTR_FATTR_CTIME) {
1911 		inode->i_ctime = timespec_to_timespec64(fattr->ctime);
1912 	} else if (server->caps & NFS_CAP_CTIME) {
1913 		nfsi->cache_validity |= save_cache_validity &
1914 				(NFS_INO_INVALID_CTIME
1915 				| NFS_INO_REVAL_FORCED);
1916 		cache_revalidated = false;
1917 	}
1918 
1919 	/* Check if our cached file size is stale */
1920 	if (fattr->valid & NFS_ATTR_FATTR_SIZE) {
1921 		new_isize = nfs_size_to_loff_t(fattr->size);
1922 		cur_isize = i_size_read(inode);
1923 		if (new_isize != cur_isize && !have_delegation) {
1924 			/* Do we perhaps have any outstanding writes, or has
1925 			 * the file grown beyond our last write? */
1926 			if (!nfs_have_writebacks(inode) || new_isize > cur_isize) {
1927 				i_size_write(inode, new_isize);
1928 				if (!have_writers)
1929 					invalid |= NFS_INO_INVALID_DATA;
1930 				attr_changed = true;
1931 			}
1932 			dprintk("NFS: isize change on server for file %s/%ld "
1933 					"(%Ld to %Ld)\n",
1934 					inode->i_sb->s_id,
1935 					inode->i_ino,
1936 					(long long)cur_isize,
1937 					(long long)new_isize);
1938 		}
1939 	} else {
1940 		nfsi->cache_validity |= save_cache_validity &
1941 				(NFS_INO_INVALID_SIZE
1942 				| NFS_INO_REVAL_PAGECACHE
1943 				| NFS_INO_REVAL_FORCED);
1944 		cache_revalidated = false;
1945 	}
1946 
1947 
1948 	if (fattr->valid & NFS_ATTR_FATTR_ATIME)
1949 		inode->i_atime = timespec_to_timespec64(fattr->atime);
1950 	else if (server->caps & NFS_CAP_ATIME) {
1951 		nfsi->cache_validity |= save_cache_validity &
1952 				(NFS_INO_INVALID_ATIME
1953 				| NFS_INO_REVAL_FORCED);
1954 		cache_revalidated = false;
1955 	}
1956 
1957 	if (fattr->valid & NFS_ATTR_FATTR_MODE) {
1958 		if ((inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO)) {
1959 			umode_t newmode = inode->i_mode & S_IFMT;
1960 			newmode |= fattr->mode & S_IALLUGO;
1961 			inode->i_mode = newmode;
1962 			invalid |= NFS_INO_INVALID_ACCESS
1963 				| NFS_INO_INVALID_ACL;
1964 			attr_changed = true;
1965 		}
1966 	} else if (server->caps & NFS_CAP_MODE) {
1967 		nfsi->cache_validity |= save_cache_validity &
1968 				(NFS_INO_INVALID_OTHER
1969 				| NFS_INO_REVAL_FORCED);
1970 		cache_revalidated = false;
1971 	}
1972 
1973 	if (fattr->valid & NFS_ATTR_FATTR_OWNER) {
1974 		if (!uid_eq(inode->i_uid, fattr->uid)) {
1975 			invalid |= NFS_INO_INVALID_ACCESS
1976 				| NFS_INO_INVALID_ACL;
1977 			inode->i_uid = fattr->uid;
1978 			attr_changed = true;
1979 		}
1980 	} else if (server->caps & NFS_CAP_OWNER) {
1981 		nfsi->cache_validity |= save_cache_validity &
1982 				(NFS_INO_INVALID_OTHER
1983 				| NFS_INO_REVAL_FORCED);
1984 		cache_revalidated = false;
1985 	}
1986 
1987 	if (fattr->valid & NFS_ATTR_FATTR_GROUP) {
1988 		if (!gid_eq(inode->i_gid, fattr->gid)) {
1989 			invalid |= NFS_INO_INVALID_ACCESS
1990 				| NFS_INO_INVALID_ACL;
1991 			inode->i_gid = fattr->gid;
1992 			attr_changed = true;
1993 		}
1994 	} else if (server->caps & NFS_CAP_OWNER_GROUP) {
1995 		nfsi->cache_validity |= save_cache_validity &
1996 				(NFS_INO_INVALID_OTHER
1997 				| NFS_INO_REVAL_FORCED);
1998 		cache_revalidated = false;
1999 	}
2000 
2001 	if (fattr->valid & NFS_ATTR_FATTR_NLINK) {
2002 		if (inode->i_nlink != fattr->nlink) {
2003 			if (S_ISDIR(inode->i_mode))
2004 				invalid |= NFS_INO_INVALID_DATA;
2005 			set_nlink(inode, fattr->nlink);
2006 			attr_changed = true;
2007 		}
2008 	} else if (server->caps & NFS_CAP_NLINK) {
2009 		nfsi->cache_validity |= save_cache_validity &
2010 				(NFS_INO_INVALID_OTHER
2011 				| NFS_INO_REVAL_FORCED);
2012 		cache_revalidated = false;
2013 	}
2014 
2015 	if (fattr->valid & NFS_ATTR_FATTR_SPACE_USED) {
2016 		/*
2017 		 * report the blocks in 512byte units
2018 		 */
2019 		inode->i_blocks = nfs_calc_block_size(fattr->du.nfs3.used);
2020 	} else if (fattr->valid & NFS_ATTR_FATTR_BLOCKS_USED)
2021 		inode->i_blocks = fattr->du.nfs2.blocks;
2022 	else
2023 		cache_revalidated = false;
2024 
2025 	/* Update attrtimeo value if we're out of the unstable period */
2026 	if (attr_changed) {
2027 		invalid &= ~NFS_INO_INVALID_ATTR;
2028 		nfs_inc_stats(inode, NFSIOS_ATTRINVALIDATE);
2029 		nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
2030 		nfsi->attrtimeo_timestamp = now;
2031 		/* Set barrier to be more recent than all outstanding updates */
2032 		nfsi->attr_gencount = nfs_inc_attr_generation_counter();
2033 	} else {
2034 		if (cache_revalidated) {
2035 			if (!time_in_range_open(now, nfsi->attrtimeo_timestamp,
2036 				nfsi->attrtimeo_timestamp + nfsi->attrtimeo)) {
2037 				nfsi->attrtimeo <<= 1;
2038 				if (nfsi->attrtimeo > NFS_MAXATTRTIMEO(inode))
2039 					nfsi->attrtimeo = NFS_MAXATTRTIMEO(inode);
2040 			}
2041 			nfsi->attrtimeo_timestamp = now;
2042 		}
2043 		/* Set the barrier to be more recent than this fattr */
2044 		if ((long)fattr->gencount - (long)nfsi->attr_gencount > 0)
2045 			nfsi->attr_gencount = fattr->gencount;
2046 	}
2047 
2048 	/* Don't invalidate the data if we were to blame */
2049 	if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)
2050 				|| S_ISLNK(inode->i_mode)))
2051 		invalid &= ~NFS_INO_INVALID_DATA;
2052 	nfs_set_cache_invalid(inode, invalid);
2053 
2054 	return 0;
2055  out_err:
2056 	/*
2057 	 * No need to worry about unhashing the dentry, as the
2058 	 * lookup validation will know that the inode is bad.
2059 	 * (But we fall through to invalidate the caches.)
2060 	 */
2061 	nfs_invalidate_inode(inode);
2062 	return -ESTALE;
2063 }
2064 
2065 struct inode *nfs_alloc_inode(struct super_block *sb)
2066 {
2067 	struct nfs_inode *nfsi;
2068 	nfsi = kmem_cache_alloc(nfs_inode_cachep, GFP_KERNEL);
2069 	if (!nfsi)
2070 		return NULL;
2071 	nfsi->flags = 0UL;
2072 	nfsi->cache_validity = 0UL;
2073 #if IS_ENABLED(CONFIG_NFS_V4)
2074 	nfsi->nfs4_acl = NULL;
2075 #endif /* CONFIG_NFS_V4 */
2076 	return &nfsi->vfs_inode;
2077 }
2078 EXPORT_SYMBOL_GPL(nfs_alloc_inode);
2079 
2080 void nfs_free_inode(struct inode *inode)
2081 {
2082 	kmem_cache_free(nfs_inode_cachep, NFS_I(inode));
2083 }
2084 EXPORT_SYMBOL_GPL(nfs_free_inode);
2085 
2086 static inline void nfs4_init_once(struct nfs_inode *nfsi)
2087 {
2088 #if IS_ENABLED(CONFIG_NFS_V4)
2089 	INIT_LIST_HEAD(&nfsi->open_states);
2090 	nfsi->delegation = NULL;
2091 	init_rwsem(&nfsi->rwsem);
2092 	nfsi->layout = NULL;
2093 #endif
2094 }
2095 
2096 static void init_once(void *foo)
2097 {
2098 	struct nfs_inode *nfsi = (struct nfs_inode *) foo;
2099 
2100 	inode_init_once(&nfsi->vfs_inode);
2101 	INIT_LIST_HEAD(&nfsi->open_files);
2102 	INIT_LIST_HEAD(&nfsi->access_cache_entry_lru);
2103 	INIT_LIST_HEAD(&nfsi->access_cache_inode_lru);
2104 	INIT_LIST_HEAD(&nfsi->commit_info.list);
2105 	atomic_long_set(&nfsi->nrequests, 0);
2106 	atomic_long_set(&nfsi->commit_info.ncommit, 0);
2107 	atomic_set(&nfsi->commit_info.rpcs_out, 0);
2108 	init_rwsem(&nfsi->rmdir_sem);
2109 	mutex_init(&nfsi->commit_mutex);
2110 	nfs4_init_once(nfsi);
2111 }
2112 
2113 static int __init nfs_init_inodecache(void)
2114 {
2115 	nfs_inode_cachep = kmem_cache_create("nfs_inode_cache",
2116 					     sizeof(struct nfs_inode),
2117 					     0, (SLAB_RECLAIM_ACCOUNT|
2118 						SLAB_MEM_SPREAD|SLAB_ACCOUNT),
2119 					     init_once);
2120 	if (nfs_inode_cachep == NULL)
2121 		return -ENOMEM;
2122 
2123 	return 0;
2124 }
2125 
2126 static void nfs_destroy_inodecache(void)
2127 {
2128 	/*
2129 	 * Make sure all delayed rcu free inodes are flushed before we
2130 	 * destroy cache.
2131 	 */
2132 	rcu_barrier();
2133 	kmem_cache_destroy(nfs_inode_cachep);
2134 }
2135 
2136 struct workqueue_struct *nfsiod_workqueue;
2137 EXPORT_SYMBOL_GPL(nfsiod_workqueue);
2138 
2139 /*
2140  * start up the nfsiod workqueue
2141  */
2142 static int nfsiod_start(void)
2143 {
2144 	struct workqueue_struct *wq;
2145 	dprintk("RPC:       creating workqueue nfsiod\n");
2146 	wq = alloc_workqueue("nfsiod", WQ_MEM_RECLAIM, 0);
2147 	if (wq == NULL)
2148 		return -ENOMEM;
2149 	nfsiod_workqueue = wq;
2150 	return 0;
2151 }
2152 
2153 /*
2154  * Destroy the nfsiod workqueue
2155  */
2156 static void nfsiod_stop(void)
2157 {
2158 	struct workqueue_struct *wq;
2159 
2160 	wq = nfsiod_workqueue;
2161 	if (wq == NULL)
2162 		return;
2163 	nfsiod_workqueue = NULL;
2164 	destroy_workqueue(wq);
2165 }
2166 
2167 unsigned int nfs_net_id;
2168 EXPORT_SYMBOL_GPL(nfs_net_id);
2169 
2170 static int nfs_net_init(struct net *net)
2171 {
2172 	nfs_clients_init(net);
2173 	return nfs_fs_proc_net_init(net);
2174 }
2175 
2176 static void nfs_net_exit(struct net *net)
2177 {
2178 	nfs_fs_proc_net_exit(net);
2179 	nfs_clients_exit(net);
2180 }
2181 
2182 static struct pernet_operations nfs_net_ops = {
2183 	.init = nfs_net_init,
2184 	.exit = nfs_net_exit,
2185 	.id   = &nfs_net_id,
2186 	.size = sizeof(struct nfs_net),
2187 };
2188 
2189 /*
2190  * Initialize NFS
2191  */
2192 static int __init init_nfs_fs(void)
2193 {
2194 	int err;
2195 
2196 	err = nfs_sysfs_init();
2197 	if (err < 0)
2198 		goto out10;
2199 
2200 	err = register_pernet_subsys(&nfs_net_ops);
2201 	if (err < 0)
2202 		goto out9;
2203 
2204 	err = nfs_fscache_register();
2205 	if (err < 0)
2206 		goto out8;
2207 
2208 	err = nfsiod_start();
2209 	if (err)
2210 		goto out7;
2211 
2212 	err = nfs_fs_proc_init();
2213 	if (err)
2214 		goto out6;
2215 
2216 	err = nfs_init_nfspagecache();
2217 	if (err)
2218 		goto out5;
2219 
2220 	err = nfs_init_inodecache();
2221 	if (err)
2222 		goto out4;
2223 
2224 	err = nfs_init_readpagecache();
2225 	if (err)
2226 		goto out3;
2227 
2228 	err = nfs_init_writepagecache();
2229 	if (err)
2230 		goto out2;
2231 
2232 	err = nfs_init_directcache();
2233 	if (err)
2234 		goto out1;
2235 
2236 	rpc_proc_register(&init_net, &nfs_rpcstat);
2237 
2238 	err = register_nfs_fs();
2239 	if (err)
2240 		goto out0;
2241 
2242 	return 0;
2243 out0:
2244 	rpc_proc_unregister(&init_net, "nfs");
2245 	nfs_destroy_directcache();
2246 out1:
2247 	nfs_destroy_writepagecache();
2248 out2:
2249 	nfs_destroy_readpagecache();
2250 out3:
2251 	nfs_destroy_inodecache();
2252 out4:
2253 	nfs_destroy_nfspagecache();
2254 out5:
2255 	nfs_fs_proc_exit();
2256 out6:
2257 	nfsiod_stop();
2258 out7:
2259 	nfs_fscache_unregister();
2260 out8:
2261 	unregister_pernet_subsys(&nfs_net_ops);
2262 out9:
2263 	nfs_sysfs_exit();
2264 out10:
2265 	return err;
2266 }
2267 
2268 static void __exit exit_nfs_fs(void)
2269 {
2270 	nfs_destroy_directcache();
2271 	nfs_destroy_writepagecache();
2272 	nfs_destroy_readpagecache();
2273 	nfs_destroy_inodecache();
2274 	nfs_destroy_nfspagecache();
2275 	nfs_fscache_unregister();
2276 	unregister_pernet_subsys(&nfs_net_ops);
2277 	rpc_proc_unregister(&init_net, "nfs");
2278 	unregister_nfs_fs();
2279 	nfs_fs_proc_exit();
2280 	nfsiod_stop();
2281 	nfs_sysfs_exit();
2282 }
2283 
2284 /* Not quite true; I just maintain it */
2285 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
2286 MODULE_LICENSE("GPL");
2287 module_param(enable_ino64, bool, 0644);
2288 
2289 module_init(init_nfs_fs)
2290 module_exit(exit_nfs_fs)
2291