xref: /linux/fs/nfs/inode.c (revision c5d3cdad688ed75fb311a3a671eb30ba7106d7d3)
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 static int nfs_wait_killable(int mode)
76 {
77 	freezable_schedule_unsafe();
78 	if (signal_pending_state(mode, current))
79 		return -ERESTARTSYS;
80 	return 0;
81 }
82 
83 int nfs_wait_bit_killable(struct wait_bit_key *key, int mode)
84 {
85 	return nfs_wait_killable(mode);
86 }
87 EXPORT_SYMBOL_GPL(nfs_wait_bit_killable);
88 
89 /**
90  * nfs_compat_user_ino64 - returns the user-visible inode number
91  * @fileid: 64-bit fileid
92  *
93  * This function returns a 32-bit inode number if the boot parameter
94  * nfs.enable_ino64 is zero.
95  */
96 u64 nfs_compat_user_ino64(u64 fileid)
97 {
98 #ifdef CONFIG_COMPAT
99 	compat_ulong_t ino;
100 #else
101 	unsigned long ino;
102 #endif
103 
104 	if (enable_ino64)
105 		return fileid;
106 	ino = fileid;
107 	if (sizeof(ino) < sizeof(fileid))
108 		ino ^= fileid >> (sizeof(fileid)-sizeof(ino)) * 8;
109 	return ino;
110 }
111 
112 int nfs_drop_inode(struct inode *inode)
113 {
114 	return NFS_STALE(inode) || generic_drop_inode(inode);
115 }
116 EXPORT_SYMBOL_GPL(nfs_drop_inode);
117 
118 void nfs_clear_inode(struct inode *inode)
119 {
120 	/*
121 	 * The following should never happen...
122 	 */
123 	WARN_ON_ONCE(nfs_have_writebacks(inode));
124 	WARN_ON_ONCE(!list_empty(&NFS_I(inode)->open_files));
125 	nfs_zap_acl_cache(inode);
126 	nfs_access_zap_cache(inode);
127 	nfs_fscache_clear_inode(inode);
128 }
129 EXPORT_SYMBOL_GPL(nfs_clear_inode);
130 
131 void nfs_evict_inode(struct inode *inode)
132 {
133 	truncate_inode_pages_final(&inode->i_data);
134 	clear_inode(inode);
135 	nfs_clear_inode(inode);
136 }
137 
138 int nfs_sync_inode(struct inode *inode)
139 {
140 	inode_dio_wait(inode);
141 	return nfs_wb_all(inode);
142 }
143 EXPORT_SYMBOL_GPL(nfs_sync_inode);
144 
145 /**
146  * nfs_sync_mapping - helper to flush all mmapped dirty data to disk
147  * @mapping: pointer to struct address_space
148  */
149 int nfs_sync_mapping(struct address_space *mapping)
150 {
151 	int ret = 0;
152 
153 	if (mapping->nrpages != 0) {
154 		unmap_mapping_range(mapping, 0, 0, 0);
155 		ret = nfs_wb_all(mapping->host);
156 	}
157 	return ret;
158 }
159 
160 static int nfs_attribute_timeout(struct inode *inode)
161 {
162 	struct nfs_inode *nfsi = NFS_I(inode);
163 
164 	return !time_in_range_open(jiffies, nfsi->read_cache_jiffies, nfsi->read_cache_jiffies + nfsi->attrtimeo);
165 }
166 
167 static bool nfs_check_cache_invalid_delegated(struct inode *inode, unsigned long flags)
168 {
169 	unsigned long cache_validity = READ_ONCE(NFS_I(inode)->cache_validity);
170 
171 	/* Special case for the pagecache or access cache */
172 	if (flags == NFS_INO_REVAL_PAGECACHE &&
173 	    !(cache_validity & NFS_INO_REVAL_FORCED))
174 		return false;
175 	return (cache_validity & flags) != 0;
176 }
177 
178 static bool nfs_check_cache_invalid_not_delegated(struct inode *inode, unsigned long flags)
179 {
180 	unsigned long cache_validity = READ_ONCE(NFS_I(inode)->cache_validity);
181 
182 	if ((cache_validity & flags) != 0)
183 		return true;
184 	if (nfs_attribute_timeout(inode))
185 		return true;
186 	return false;
187 }
188 
189 bool nfs_check_cache_invalid(struct inode *inode, unsigned long flags)
190 {
191 	if (NFS_PROTO(inode)->have_delegation(inode, FMODE_READ))
192 		return nfs_check_cache_invalid_delegated(inode, flags);
193 
194 	return nfs_check_cache_invalid_not_delegated(inode, flags);
195 }
196 
197 static void nfs_set_cache_invalid(struct inode *inode, unsigned long flags)
198 {
199 	struct nfs_inode *nfsi = NFS_I(inode);
200 	bool have_delegation = NFS_PROTO(inode)->have_delegation(inode, FMODE_READ);
201 
202 	if (have_delegation) {
203 		if (!(flags & NFS_INO_REVAL_FORCED))
204 			flags &= ~NFS_INO_INVALID_OTHER;
205 		flags &= ~(NFS_INO_INVALID_CHANGE
206 				| NFS_INO_INVALID_SIZE
207 				| NFS_INO_REVAL_PAGECACHE);
208 	}
209 
210 	if (inode->i_mapping->nrpages == 0)
211 		flags &= ~(NFS_INO_INVALID_DATA|NFS_INO_DATA_INVAL_DEFER);
212 	nfsi->cache_validity |= flags;
213 	if (flags & NFS_INO_INVALID_DATA)
214 		nfs_fscache_invalidate(inode);
215 }
216 
217 /*
218  * Invalidate the local caches
219  */
220 static void nfs_zap_caches_locked(struct inode *inode)
221 {
222 	struct nfs_inode *nfsi = NFS_I(inode);
223 	int mode = inode->i_mode;
224 
225 	nfs_inc_stats(inode, NFSIOS_ATTRINVALIDATE);
226 
227 	nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
228 	nfsi->attrtimeo_timestamp = jiffies;
229 
230 	memset(NFS_I(inode)->cookieverf, 0, sizeof(NFS_I(inode)->cookieverf));
231 	if (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)) {
232 		nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR
233 					| NFS_INO_INVALID_DATA
234 					| NFS_INO_INVALID_ACCESS
235 					| NFS_INO_INVALID_ACL
236 					| NFS_INO_REVAL_PAGECACHE);
237 	} else
238 		nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR
239 					| NFS_INO_INVALID_ACCESS
240 					| NFS_INO_INVALID_ACL
241 					| NFS_INO_REVAL_PAGECACHE);
242 	nfs_zap_label_cache_locked(nfsi);
243 }
244 
245 void nfs_zap_caches(struct inode *inode)
246 {
247 	spin_lock(&inode->i_lock);
248 	nfs_zap_caches_locked(inode);
249 	spin_unlock(&inode->i_lock);
250 }
251 
252 void nfs_zap_mapping(struct inode *inode, struct address_space *mapping)
253 {
254 	if (mapping->nrpages != 0) {
255 		spin_lock(&inode->i_lock);
256 		nfs_set_cache_invalid(inode, NFS_INO_INVALID_DATA);
257 		spin_unlock(&inode->i_lock);
258 	}
259 }
260 
261 void nfs_zap_acl_cache(struct inode *inode)
262 {
263 	void (*clear_acl_cache)(struct inode *);
264 
265 	clear_acl_cache = NFS_PROTO(inode)->clear_acl_cache;
266 	if (clear_acl_cache != NULL)
267 		clear_acl_cache(inode);
268 	spin_lock(&inode->i_lock);
269 	NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_ACL;
270 	spin_unlock(&inode->i_lock);
271 }
272 EXPORT_SYMBOL_GPL(nfs_zap_acl_cache);
273 
274 void nfs_invalidate_atime(struct inode *inode)
275 {
276 	spin_lock(&inode->i_lock);
277 	nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATIME);
278 	spin_unlock(&inode->i_lock);
279 }
280 EXPORT_SYMBOL_GPL(nfs_invalidate_atime);
281 
282 /*
283  * Invalidate, but do not unhash, the inode.
284  * NB: must be called with inode->i_lock held!
285  */
286 static void nfs_set_inode_stale_locked(struct inode *inode)
287 {
288 	set_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
289 	nfs_zap_caches_locked(inode);
290 	trace_nfs_set_inode_stale(inode);
291 }
292 
293 void nfs_set_inode_stale(struct inode *inode)
294 {
295 	spin_lock(&inode->i_lock);
296 	nfs_set_inode_stale_locked(inode);
297 	spin_unlock(&inode->i_lock);
298 }
299 
300 struct nfs_find_desc {
301 	struct nfs_fh		*fh;
302 	struct nfs_fattr	*fattr;
303 };
304 
305 /*
306  * In NFSv3 we can have 64bit inode numbers. In order to support
307  * this, and re-exported directories (also seen in NFSv2)
308  * we are forced to allow 2 different inodes to have the same
309  * i_ino.
310  */
311 static int
312 nfs_find_actor(struct inode *inode, void *opaque)
313 {
314 	struct nfs_find_desc	*desc = (struct nfs_find_desc *)opaque;
315 	struct nfs_fh		*fh = desc->fh;
316 	struct nfs_fattr	*fattr = desc->fattr;
317 
318 	if (NFS_FILEID(inode) != fattr->fileid)
319 		return 0;
320 	if ((S_IFMT & inode->i_mode) != (S_IFMT & fattr->mode))
321 		return 0;
322 	if (nfs_compare_fh(NFS_FH(inode), fh))
323 		return 0;
324 	if (is_bad_inode(inode) || NFS_STALE(inode))
325 		return 0;
326 	return 1;
327 }
328 
329 static int
330 nfs_init_locked(struct inode *inode, void *opaque)
331 {
332 	struct nfs_find_desc	*desc = (struct nfs_find_desc *)opaque;
333 	struct nfs_fattr	*fattr = desc->fattr;
334 
335 	set_nfs_fileid(inode, fattr->fileid);
336 	inode->i_mode = fattr->mode;
337 	nfs_copy_fh(NFS_FH(inode), desc->fh);
338 	return 0;
339 }
340 
341 #ifdef CONFIG_NFS_V4_SECURITY_LABEL
342 static void nfs_clear_label_invalid(struct inode *inode)
343 {
344 	spin_lock(&inode->i_lock);
345 	NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_LABEL;
346 	spin_unlock(&inode->i_lock);
347 }
348 
349 void nfs_setsecurity(struct inode *inode, struct nfs_fattr *fattr,
350 					struct nfs4_label *label)
351 {
352 	int error;
353 
354 	if (label == NULL)
355 		return;
356 
357 	if ((fattr->valid & NFS_ATTR_FATTR_V4_SECURITY_LABEL) && inode->i_security) {
358 		error = security_inode_notifysecctx(inode, label->label,
359 				label->len);
360 		if (error)
361 			printk(KERN_ERR "%s() %s %d "
362 					"security_inode_notifysecctx() %d\n",
363 					__func__,
364 					(char *)label->label,
365 					label->len, error);
366 		nfs_clear_label_invalid(inode);
367 	}
368 }
369 
370 struct nfs4_label *nfs4_label_alloc(struct nfs_server *server, gfp_t flags)
371 {
372 	struct nfs4_label *label = NULL;
373 	int minor_version = server->nfs_client->cl_minorversion;
374 
375 	if (minor_version < 2)
376 		return label;
377 
378 	if (!(server->caps & NFS_CAP_SECURITY_LABEL))
379 		return label;
380 
381 	label = kzalloc(sizeof(struct nfs4_label), flags);
382 	if (label == NULL)
383 		return ERR_PTR(-ENOMEM);
384 
385 	label->label = kzalloc(NFS4_MAXLABELLEN, flags);
386 	if (label->label == NULL) {
387 		kfree(label);
388 		return ERR_PTR(-ENOMEM);
389 	}
390 	label->len = NFS4_MAXLABELLEN;
391 
392 	return label;
393 }
394 EXPORT_SYMBOL_GPL(nfs4_label_alloc);
395 #else
396 void nfs_setsecurity(struct inode *inode, struct nfs_fattr *fattr,
397 					struct nfs4_label *label)
398 {
399 }
400 #endif
401 EXPORT_SYMBOL_GPL(nfs_setsecurity);
402 
403 /* Search for inode identified by fh, fileid and i_mode in inode cache. */
404 struct inode *
405 nfs_ilookup(struct super_block *sb, struct nfs_fattr *fattr, struct nfs_fh *fh)
406 {
407 	struct nfs_find_desc desc = {
408 		.fh	= fh,
409 		.fattr	= fattr,
410 	};
411 	struct inode *inode;
412 	unsigned long hash;
413 
414 	if (!(fattr->valid & NFS_ATTR_FATTR_FILEID) ||
415 	    !(fattr->valid & NFS_ATTR_FATTR_TYPE))
416 		return NULL;
417 
418 	hash = nfs_fattr_to_ino_t(fattr);
419 	inode = ilookup5(sb, hash, nfs_find_actor, &desc);
420 
421 	dprintk("%s: returning %p\n", __func__, inode);
422 	return inode;
423 }
424 
425 /*
426  * This is our front-end to iget that looks up inodes by file handle
427  * instead of inode number.
428  */
429 struct inode *
430 nfs_fhget(struct super_block *sb, struct nfs_fh *fh, struct nfs_fattr *fattr, struct nfs4_label *label)
431 {
432 	struct nfs_find_desc desc = {
433 		.fh	= fh,
434 		.fattr	= fattr
435 	};
436 	struct inode *inode = ERR_PTR(-ENOENT);
437 	unsigned long hash;
438 
439 	nfs_attr_check_mountpoint(sb, fattr);
440 
441 	if (nfs_attr_use_mounted_on_fileid(fattr))
442 		fattr->fileid = fattr->mounted_on_fileid;
443 	else if ((fattr->valid & NFS_ATTR_FATTR_FILEID) == 0)
444 		goto out_no_inode;
445 	if ((fattr->valid & NFS_ATTR_FATTR_TYPE) == 0)
446 		goto out_no_inode;
447 
448 	hash = nfs_fattr_to_ino_t(fattr);
449 
450 	inode = iget5_locked(sb, hash, nfs_find_actor, nfs_init_locked, &desc);
451 	if (inode == NULL) {
452 		inode = ERR_PTR(-ENOMEM);
453 		goto out_no_inode;
454 	}
455 
456 	if (inode->i_state & I_NEW) {
457 		struct nfs_inode *nfsi = NFS_I(inode);
458 		unsigned long now = jiffies;
459 
460 		/* We set i_ino for the few things that still rely on it,
461 		 * such as stat(2) */
462 		inode->i_ino = hash;
463 
464 		/* We can't support update_atime(), since the server will reset it */
465 		inode->i_flags |= S_NOATIME|S_NOCMTIME;
466 		inode->i_mode = fattr->mode;
467 		nfsi->cache_validity = 0;
468 		if ((fattr->valid & NFS_ATTR_FATTR_MODE) == 0
469 				&& nfs_server_capable(inode, NFS_CAP_MODE))
470 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_OTHER);
471 		/* Why so? Because we want revalidate for devices/FIFOs, and
472 		 * that's precisely what we have in nfs_file_inode_operations.
473 		 */
474 		inode->i_op = NFS_SB(sb)->nfs_client->rpc_ops->file_inode_ops;
475 		if (S_ISREG(inode->i_mode)) {
476 			inode->i_fop = NFS_SB(sb)->nfs_client->rpc_ops->file_ops;
477 			inode->i_data.a_ops = &nfs_file_aops;
478 		} else if (S_ISDIR(inode->i_mode)) {
479 			inode->i_op = NFS_SB(sb)->nfs_client->rpc_ops->dir_inode_ops;
480 			inode->i_fop = &nfs_dir_operations;
481 			inode->i_data.a_ops = &nfs_dir_aops;
482 			/* Deal with crossing mountpoints */
483 			if (fattr->valid & NFS_ATTR_FATTR_MOUNTPOINT ||
484 					fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL) {
485 				if (fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL)
486 					inode->i_op = &nfs_referral_inode_operations;
487 				else
488 					inode->i_op = &nfs_mountpoint_inode_operations;
489 				inode->i_fop = NULL;
490 				inode->i_flags |= S_AUTOMOUNT;
491 			}
492 		} else if (S_ISLNK(inode->i_mode)) {
493 			inode->i_op = &nfs_symlink_inode_operations;
494 			inode_nohighmem(inode);
495 		} else
496 			init_special_inode(inode, inode->i_mode, fattr->rdev);
497 
498 		memset(&inode->i_atime, 0, sizeof(inode->i_atime));
499 		memset(&inode->i_mtime, 0, sizeof(inode->i_mtime));
500 		memset(&inode->i_ctime, 0, sizeof(inode->i_ctime));
501 		inode_set_iversion_raw(inode, 0);
502 		inode->i_size = 0;
503 		clear_nlink(inode);
504 		inode->i_uid = make_kuid(&init_user_ns, -2);
505 		inode->i_gid = make_kgid(&init_user_ns, -2);
506 		inode->i_blocks = 0;
507 		memset(nfsi->cookieverf, 0, sizeof(nfsi->cookieverf));
508 		nfsi->write_io = 0;
509 		nfsi->read_io = 0;
510 
511 		nfsi->read_cache_jiffies = fattr->time_start;
512 		nfsi->attr_gencount = fattr->gencount;
513 		if (fattr->valid & NFS_ATTR_FATTR_ATIME)
514 			inode->i_atime = fattr->atime;
515 		else if (nfs_server_capable(inode, NFS_CAP_ATIME))
516 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATIME);
517 		if (fattr->valid & NFS_ATTR_FATTR_MTIME)
518 			inode->i_mtime = fattr->mtime;
519 		else if (nfs_server_capable(inode, NFS_CAP_MTIME))
520 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_MTIME);
521 		if (fattr->valid & NFS_ATTR_FATTR_CTIME)
522 			inode->i_ctime = fattr->ctime;
523 		else if (nfs_server_capable(inode, NFS_CAP_CTIME))
524 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_CTIME);
525 		if (fattr->valid & NFS_ATTR_FATTR_CHANGE)
526 			inode_set_iversion_raw(inode, fattr->change_attr);
527 		else
528 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_CHANGE);
529 		if (fattr->valid & NFS_ATTR_FATTR_SIZE)
530 			inode->i_size = nfs_size_to_loff_t(fattr->size);
531 		else
532 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_SIZE);
533 		if (fattr->valid & NFS_ATTR_FATTR_NLINK)
534 			set_nlink(inode, fattr->nlink);
535 		else if (nfs_server_capable(inode, NFS_CAP_NLINK))
536 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_OTHER);
537 		if (fattr->valid & NFS_ATTR_FATTR_OWNER)
538 			inode->i_uid = fattr->uid;
539 		else if (nfs_server_capable(inode, NFS_CAP_OWNER))
540 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_OTHER);
541 		if (fattr->valid & NFS_ATTR_FATTR_GROUP)
542 			inode->i_gid = fattr->gid;
543 		else if (nfs_server_capable(inode, NFS_CAP_OWNER_GROUP))
544 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_OTHER);
545 		if (fattr->valid & NFS_ATTR_FATTR_BLOCKS_USED)
546 			inode->i_blocks = fattr->du.nfs2.blocks;
547 		if (fattr->valid & NFS_ATTR_FATTR_SPACE_USED) {
548 			/*
549 			 * report the blocks in 512byte units
550 			 */
551 			inode->i_blocks = nfs_calc_block_size(fattr->du.nfs3.used);
552 		}
553 
554 		if (nfsi->cache_validity != 0)
555 			nfsi->cache_validity |= NFS_INO_REVAL_FORCED;
556 
557 		nfs_setsecurity(inode, fattr, label);
558 
559 		nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
560 		nfsi->attrtimeo_timestamp = now;
561 		nfsi->access_cache = RB_ROOT;
562 
563 		nfs_fscache_init_inode(inode);
564 
565 		unlock_new_inode(inode);
566 	} else {
567 		int err = nfs_refresh_inode(inode, fattr);
568 		if (err < 0) {
569 			iput(inode);
570 			inode = ERR_PTR(err);
571 			goto out_no_inode;
572 		}
573 	}
574 	dprintk("NFS: nfs_fhget(%s/%Lu fh_crc=0x%08x ct=%d)\n",
575 		inode->i_sb->s_id,
576 		(unsigned long long)NFS_FILEID(inode),
577 		nfs_display_fhandle_hash(fh),
578 		atomic_read(&inode->i_count));
579 
580 out:
581 	return inode;
582 
583 out_no_inode:
584 	dprintk("nfs_fhget: iget failed with error %ld\n", PTR_ERR(inode));
585 	goto out;
586 }
587 EXPORT_SYMBOL_GPL(nfs_fhget);
588 
589 #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)
590 
591 int
592 nfs_setattr(struct dentry *dentry, struct iattr *attr)
593 {
594 	struct inode *inode = d_inode(dentry);
595 	struct nfs_fattr *fattr;
596 	int error = 0;
597 
598 	nfs_inc_stats(inode, NFSIOS_VFSSETATTR);
599 
600 	/* skip mode change if it's just for clearing setuid/setgid */
601 	if (attr->ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
602 		attr->ia_valid &= ~ATTR_MODE;
603 
604 	if (attr->ia_valid & ATTR_SIZE) {
605 		BUG_ON(!S_ISREG(inode->i_mode));
606 
607 		error = inode_newsize_ok(inode, attr->ia_size);
608 		if (error)
609 			return error;
610 
611 		if (attr->ia_size == i_size_read(inode))
612 			attr->ia_valid &= ~ATTR_SIZE;
613 	}
614 
615 	/* Optimization: if the end result is no change, don't RPC */
616 	attr->ia_valid &= NFS_VALID_ATTRS;
617 	if ((attr->ia_valid & ~(ATTR_FILE|ATTR_OPEN)) == 0)
618 		return 0;
619 
620 	trace_nfs_setattr_enter(inode);
621 
622 	/* Write all dirty data */
623 	if (S_ISREG(inode->i_mode))
624 		nfs_sync_inode(inode);
625 
626 	fattr = nfs_alloc_fattr();
627 	if (fattr == NULL) {
628 		error = -ENOMEM;
629 		goto out;
630 	}
631 
632 	error = NFS_PROTO(inode)->setattr(dentry, fattr, attr);
633 	if (error == 0)
634 		error = nfs_refresh_inode(inode, fattr);
635 	nfs_free_fattr(fattr);
636 out:
637 	trace_nfs_setattr_exit(inode, error);
638 	return error;
639 }
640 EXPORT_SYMBOL_GPL(nfs_setattr);
641 
642 /**
643  * nfs_vmtruncate - unmap mappings "freed" by truncate() syscall
644  * @inode: inode of the file used
645  * @offset: file offset to start truncating
646  *
647  * This is a copy of the common vmtruncate, but with the locking
648  * corrected to take into account the fact that NFS requires
649  * inode->i_size to be updated under the inode->i_lock.
650  * Note: must be called with inode->i_lock held!
651  */
652 static int nfs_vmtruncate(struct inode * inode, loff_t offset)
653 {
654 	int err;
655 
656 	err = inode_newsize_ok(inode, offset);
657 	if (err)
658 		goto out;
659 
660 	i_size_write(inode, offset);
661 	/* Optimisation */
662 	if (offset == 0)
663 		NFS_I(inode)->cache_validity &= ~(NFS_INO_INVALID_DATA |
664 				NFS_INO_DATA_INVAL_DEFER);
665 	NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_SIZE;
666 
667 	spin_unlock(&inode->i_lock);
668 	truncate_pagecache(inode, offset);
669 	spin_lock(&inode->i_lock);
670 out:
671 	return err;
672 }
673 
674 /**
675  * nfs_setattr_update_inode - Update inode metadata after a setattr call.
676  * @inode: pointer to struct inode
677  * @attr: pointer to struct iattr
678  * @fattr: pointer to struct nfs_fattr
679  *
680  * Note: we do this in the *proc.c in order to ensure that
681  *       it works for things like exclusive creates too.
682  */
683 void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr,
684 		struct nfs_fattr *fattr)
685 {
686 	/* Barrier: bump the attribute generation count. */
687 	nfs_fattr_set_barrier(fattr);
688 
689 	spin_lock(&inode->i_lock);
690 	NFS_I(inode)->attr_gencount = fattr->gencount;
691 	if ((attr->ia_valid & ATTR_SIZE) != 0) {
692 		nfs_set_cache_invalid(inode, NFS_INO_INVALID_MTIME);
693 		nfs_inc_stats(inode, NFSIOS_SETATTRTRUNC);
694 		nfs_vmtruncate(inode, attr->ia_size);
695 	}
696 	if ((attr->ia_valid & (ATTR_MODE|ATTR_UID|ATTR_GID)) != 0) {
697 		NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_CTIME;
698 		if ((attr->ia_valid & ATTR_MODE) != 0) {
699 			int mode = attr->ia_mode & S_IALLUGO;
700 			mode |= inode->i_mode & ~S_IALLUGO;
701 			inode->i_mode = mode;
702 		}
703 		if ((attr->ia_valid & ATTR_UID) != 0)
704 			inode->i_uid = attr->ia_uid;
705 		if ((attr->ia_valid & ATTR_GID) != 0)
706 			inode->i_gid = attr->ia_gid;
707 		if (fattr->valid & NFS_ATTR_FATTR_CTIME)
708 			inode->i_ctime = fattr->ctime;
709 		else
710 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_CHANGE
711 					| NFS_INO_INVALID_CTIME);
712 		nfs_set_cache_invalid(inode, NFS_INO_INVALID_ACCESS
713 				| NFS_INO_INVALID_ACL);
714 	}
715 	if (attr->ia_valid & (ATTR_ATIME_SET|ATTR_ATIME)) {
716 		NFS_I(inode)->cache_validity &= ~(NFS_INO_INVALID_ATIME
717 				| NFS_INO_INVALID_CTIME);
718 		if (fattr->valid & NFS_ATTR_FATTR_ATIME)
719 			inode->i_atime = fattr->atime;
720 		else if (attr->ia_valid & ATTR_ATIME_SET)
721 			inode->i_atime = attr->ia_atime;
722 		else
723 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATIME);
724 
725 		if (fattr->valid & NFS_ATTR_FATTR_CTIME)
726 			inode->i_ctime = fattr->ctime;
727 		else
728 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_CHANGE
729 					| NFS_INO_INVALID_CTIME);
730 	}
731 	if (attr->ia_valid & (ATTR_MTIME_SET|ATTR_MTIME)) {
732 		NFS_I(inode)->cache_validity &= ~(NFS_INO_INVALID_MTIME
733 				| NFS_INO_INVALID_CTIME);
734 		if (fattr->valid & NFS_ATTR_FATTR_MTIME)
735 			inode->i_mtime = fattr->mtime;
736 		else if (attr->ia_valid & ATTR_MTIME_SET)
737 			inode->i_mtime = attr->ia_mtime;
738 		else
739 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_MTIME);
740 
741 		if (fattr->valid & NFS_ATTR_FATTR_CTIME)
742 			inode->i_ctime = fattr->ctime;
743 		else
744 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_CHANGE
745 					| NFS_INO_INVALID_CTIME);
746 	}
747 	if (fattr->valid)
748 		nfs_update_inode(inode, fattr);
749 	spin_unlock(&inode->i_lock);
750 }
751 EXPORT_SYMBOL_GPL(nfs_setattr_update_inode);
752 
753 static void nfs_readdirplus_parent_cache_miss(struct dentry *dentry)
754 {
755 	struct dentry *parent;
756 
757 	if (!nfs_server_capable(d_inode(dentry), NFS_CAP_READDIRPLUS))
758 		return;
759 	parent = dget_parent(dentry);
760 	nfs_force_use_readdirplus(d_inode(parent));
761 	dput(parent);
762 }
763 
764 static void nfs_readdirplus_parent_cache_hit(struct dentry *dentry)
765 {
766 	struct dentry *parent;
767 
768 	if (!nfs_server_capable(d_inode(dentry), NFS_CAP_READDIRPLUS))
769 		return;
770 	parent = dget_parent(dentry);
771 	nfs_advise_use_readdirplus(d_inode(parent));
772 	dput(parent);
773 }
774 
775 static bool nfs_need_revalidate_inode(struct inode *inode)
776 {
777 	if (NFS_I(inode)->cache_validity &
778 			(NFS_INO_INVALID_ATTR|NFS_INO_INVALID_LABEL))
779 		return true;
780 	if (nfs_attribute_cache_expired(inode))
781 		return true;
782 	return false;
783 }
784 
785 int nfs_getattr(const struct path *path, struct kstat *stat,
786 		u32 request_mask, unsigned int query_flags)
787 {
788 	struct inode *inode = d_inode(path->dentry);
789 	struct nfs_server *server = NFS_SERVER(inode);
790 	unsigned long cache_validity;
791 	int err = 0;
792 	bool force_sync = query_flags & AT_STATX_FORCE_SYNC;
793 	bool do_update = false;
794 
795 	trace_nfs_getattr_enter(inode);
796 
797 	if ((query_flags & AT_STATX_DONT_SYNC) && !force_sync)
798 		goto out_no_update;
799 
800 	/* Flush out writes to the server in order to update c/mtime.  */
801 	if ((request_mask & (STATX_CTIME|STATX_MTIME)) &&
802 			S_ISREG(inode->i_mode)) {
803 		err = filemap_write_and_wait(inode->i_mapping);
804 		if (err)
805 			goto out;
806 	}
807 
808 	/*
809 	 * We may force a getattr if the user cares about atime.
810 	 *
811 	 * Note that we only have to check the vfsmount flags here:
812 	 *  - NFS always sets S_NOATIME by so checking it would give a
813 	 *    bogus result
814 	 *  - NFS never sets SB_NOATIME or SB_NODIRATIME so there is
815 	 *    no point in checking those.
816 	 */
817 	if ((path->mnt->mnt_flags & MNT_NOATIME) ||
818 	    ((path->mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode)))
819 		request_mask &= ~STATX_ATIME;
820 
821 	/* Is the user requesting attributes that might need revalidation? */
822 	if (!(request_mask & (STATX_MODE|STATX_NLINK|STATX_ATIME|STATX_CTIME|
823 					STATX_MTIME|STATX_UID|STATX_GID|
824 					STATX_SIZE|STATX_BLOCKS)))
825 		goto out_no_revalidate;
826 
827 	/* Check whether the cached attributes are stale */
828 	do_update |= force_sync || nfs_attribute_cache_expired(inode);
829 	cache_validity = READ_ONCE(NFS_I(inode)->cache_validity);
830 	do_update |= cache_validity &
831 		(NFS_INO_INVALID_ATTR|NFS_INO_INVALID_LABEL);
832 	if (request_mask & STATX_ATIME)
833 		do_update |= cache_validity & NFS_INO_INVALID_ATIME;
834 	if (request_mask & (STATX_CTIME|STATX_MTIME))
835 		do_update |= cache_validity & NFS_INO_REVAL_PAGECACHE;
836 	if (do_update) {
837 		/* Update the attribute cache */
838 		if (!(server->flags & NFS_MOUNT_NOAC))
839 			nfs_readdirplus_parent_cache_miss(path->dentry);
840 		else
841 			nfs_readdirplus_parent_cache_hit(path->dentry);
842 		err = __nfs_revalidate_inode(server, inode);
843 		if (err)
844 			goto out;
845 	} else
846 		nfs_readdirplus_parent_cache_hit(path->dentry);
847 out_no_revalidate:
848 	/* Only return attributes that were revalidated. */
849 	stat->result_mask &= request_mask;
850 out_no_update:
851 	generic_fillattr(inode, stat);
852 	stat->ino = nfs_compat_user_ino64(NFS_FILEID(inode));
853 	if (S_ISDIR(inode->i_mode))
854 		stat->blksize = NFS_SERVER(inode)->dtsize;
855 out:
856 	trace_nfs_getattr_exit(inode, err);
857 	return err;
858 }
859 EXPORT_SYMBOL_GPL(nfs_getattr);
860 
861 static void nfs_init_lock_context(struct nfs_lock_context *l_ctx)
862 {
863 	refcount_set(&l_ctx->count, 1);
864 	l_ctx->lockowner = current->files;
865 	INIT_LIST_HEAD(&l_ctx->list);
866 	atomic_set(&l_ctx->io_count, 0);
867 }
868 
869 static struct nfs_lock_context *__nfs_find_lock_context(struct nfs_open_context *ctx)
870 {
871 	struct nfs_lock_context *pos;
872 
873 	list_for_each_entry_rcu(pos, &ctx->lock_context.list, list) {
874 		if (pos->lockowner != current->files)
875 			continue;
876 		if (refcount_inc_not_zero(&pos->count))
877 			return pos;
878 	}
879 	return NULL;
880 }
881 
882 struct nfs_lock_context *nfs_get_lock_context(struct nfs_open_context *ctx)
883 {
884 	struct nfs_lock_context *res, *new = NULL;
885 	struct inode *inode = d_inode(ctx->dentry);
886 
887 	rcu_read_lock();
888 	res = __nfs_find_lock_context(ctx);
889 	rcu_read_unlock();
890 	if (res == NULL) {
891 		new = kmalloc(sizeof(*new), GFP_KERNEL);
892 		if (new == NULL)
893 			return ERR_PTR(-ENOMEM);
894 		nfs_init_lock_context(new);
895 		spin_lock(&inode->i_lock);
896 		res = __nfs_find_lock_context(ctx);
897 		if (res == NULL) {
898 			new->open_context = get_nfs_open_context(ctx);
899 			if (new->open_context) {
900 				list_add_tail_rcu(&new->list,
901 						&ctx->lock_context.list);
902 				res = new;
903 				new = NULL;
904 			} else
905 				res = ERR_PTR(-EBADF);
906 		}
907 		spin_unlock(&inode->i_lock);
908 		kfree(new);
909 	}
910 	return res;
911 }
912 EXPORT_SYMBOL_GPL(nfs_get_lock_context);
913 
914 void nfs_put_lock_context(struct nfs_lock_context *l_ctx)
915 {
916 	struct nfs_open_context *ctx = l_ctx->open_context;
917 	struct inode *inode = d_inode(ctx->dentry);
918 
919 	if (!refcount_dec_and_lock(&l_ctx->count, &inode->i_lock))
920 		return;
921 	list_del_rcu(&l_ctx->list);
922 	spin_unlock(&inode->i_lock);
923 	put_nfs_open_context(ctx);
924 	kfree_rcu(l_ctx, rcu_head);
925 }
926 EXPORT_SYMBOL_GPL(nfs_put_lock_context);
927 
928 /**
929  * nfs_close_context - Common close_context() routine NFSv2/v3
930  * @ctx: pointer to context
931  * @is_sync: is this a synchronous close
932  *
933  * Ensure that the attributes are up to date if we're mounted
934  * with close-to-open semantics and we have cached data that will
935  * need to be revalidated on open.
936  */
937 void nfs_close_context(struct nfs_open_context *ctx, int is_sync)
938 {
939 	struct nfs_inode *nfsi;
940 	struct inode *inode;
941 	struct nfs_server *server;
942 
943 	if (!(ctx->mode & FMODE_WRITE))
944 		return;
945 	if (!is_sync)
946 		return;
947 	inode = d_inode(ctx->dentry);
948 	if (NFS_PROTO(inode)->have_delegation(inode, FMODE_READ))
949 		return;
950 	nfsi = NFS_I(inode);
951 	if (inode->i_mapping->nrpages == 0)
952 		return;
953 	if (nfsi->cache_validity & NFS_INO_INVALID_DATA)
954 		return;
955 	if (!list_empty(&nfsi->open_files))
956 		return;
957 	server = NFS_SERVER(inode);
958 	if (server->flags & NFS_MOUNT_NOCTO)
959 		return;
960 	nfs_revalidate_inode(server, inode);
961 }
962 EXPORT_SYMBOL_GPL(nfs_close_context);
963 
964 struct nfs_open_context *alloc_nfs_open_context(struct dentry *dentry,
965 						fmode_t f_mode,
966 						struct file *filp)
967 {
968 	struct nfs_open_context *ctx;
969 
970 	ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
971 	if (!ctx)
972 		return ERR_PTR(-ENOMEM);
973 	nfs_sb_active(dentry->d_sb);
974 	ctx->dentry = dget(dentry);
975 	if (filp)
976 		ctx->cred = get_cred(filp->f_cred);
977 	else
978 		ctx->cred = get_current_cred();
979 	ctx->ll_cred = NULL;
980 	ctx->state = NULL;
981 	ctx->mode = f_mode;
982 	ctx->flags = 0;
983 	ctx->error = 0;
984 	ctx->flock_owner = (fl_owner_t)filp;
985 	nfs_init_lock_context(&ctx->lock_context);
986 	ctx->lock_context.open_context = ctx;
987 	INIT_LIST_HEAD(&ctx->list);
988 	ctx->mdsthreshold = NULL;
989 	return ctx;
990 }
991 EXPORT_SYMBOL_GPL(alloc_nfs_open_context);
992 
993 struct nfs_open_context *get_nfs_open_context(struct nfs_open_context *ctx)
994 {
995 	if (ctx != NULL && refcount_inc_not_zero(&ctx->lock_context.count))
996 		return ctx;
997 	return NULL;
998 }
999 EXPORT_SYMBOL_GPL(get_nfs_open_context);
1000 
1001 static void __put_nfs_open_context(struct nfs_open_context *ctx, int is_sync)
1002 {
1003 	struct inode *inode = d_inode(ctx->dentry);
1004 	struct super_block *sb = ctx->dentry->d_sb;
1005 
1006 	if (!refcount_dec_and_test(&ctx->lock_context.count))
1007 		return;
1008 	if (!list_empty(&ctx->list)) {
1009 		spin_lock(&inode->i_lock);
1010 		list_del_rcu(&ctx->list);
1011 		spin_unlock(&inode->i_lock);
1012 	}
1013 	if (inode != NULL)
1014 		NFS_PROTO(inode)->close_context(ctx, is_sync);
1015 	put_cred(ctx->cred);
1016 	dput(ctx->dentry);
1017 	nfs_sb_deactive(sb);
1018 	put_rpccred(ctx->ll_cred);
1019 	kfree(ctx->mdsthreshold);
1020 	kfree_rcu(ctx, rcu_head);
1021 }
1022 
1023 void put_nfs_open_context(struct nfs_open_context *ctx)
1024 {
1025 	__put_nfs_open_context(ctx, 0);
1026 }
1027 EXPORT_SYMBOL_GPL(put_nfs_open_context);
1028 
1029 static void put_nfs_open_context_sync(struct nfs_open_context *ctx)
1030 {
1031 	__put_nfs_open_context(ctx, 1);
1032 }
1033 
1034 /*
1035  * Ensure that mmap has a recent RPC credential for use when writing out
1036  * shared pages
1037  */
1038 void nfs_inode_attach_open_context(struct nfs_open_context *ctx)
1039 {
1040 	struct inode *inode = d_inode(ctx->dentry);
1041 	struct nfs_inode *nfsi = NFS_I(inode);
1042 
1043 	spin_lock(&inode->i_lock);
1044 	if (list_empty(&nfsi->open_files) &&
1045 	    (nfsi->cache_validity & NFS_INO_DATA_INVAL_DEFER))
1046 		nfsi->cache_validity |= NFS_INO_INVALID_DATA |
1047 			NFS_INO_REVAL_FORCED;
1048 	list_add_tail_rcu(&ctx->list, &nfsi->open_files);
1049 	spin_unlock(&inode->i_lock);
1050 }
1051 EXPORT_SYMBOL_GPL(nfs_inode_attach_open_context);
1052 
1053 void nfs_file_set_open_context(struct file *filp, struct nfs_open_context *ctx)
1054 {
1055 	filp->private_data = get_nfs_open_context(ctx);
1056 	if (list_empty(&ctx->list))
1057 		nfs_inode_attach_open_context(ctx);
1058 }
1059 EXPORT_SYMBOL_GPL(nfs_file_set_open_context);
1060 
1061 /*
1062  * Given an inode, search for an open context with the desired characteristics
1063  */
1064 struct nfs_open_context *nfs_find_open_context(struct inode *inode, const struct cred *cred, fmode_t mode)
1065 {
1066 	struct nfs_inode *nfsi = NFS_I(inode);
1067 	struct nfs_open_context *pos, *ctx = NULL;
1068 
1069 	rcu_read_lock();
1070 	list_for_each_entry_rcu(pos, &nfsi->open_files, list) {
1071 		if (cred != NULL && cred_fscmp(pos->cred, cred) != 0)
1072 			continue;
1073 		if ((pos->mode & (FMODE_READ|FMODE_WRITE)) != mode)
1074 			continue;
1075 		ctx = get_nfs_open_context(pos);
1076 		if (ctx)
1077 			break;
1078 	}
1079 	rcu_read_unlock();
1080 	return ctx;
1081 }
1082 
1083 void nfs_file_clear_open_context(struct file *filp)
1084 {
1085 	struct nfs_open_context *ctx = nfs_file_open_context(filp);
1086 
1087 	if (ctx) {
1088 		struct inode *inode = d_inode(ctx->dentry);
1089 
1090 		/*
1091 		 * We fatal error on write before. Try to writeback
1092 		 * every page again.
1093 		 */
1094 		if (ctx->error < 0)
1095 			invalidate_inode_pages2(inode->i_mapping);
1096 		filp->private_data = NULL;
1097 		put_nfs_open_context_sync(ctx);
1098 	}
1099 }
1100 
1101 /*
1102  * These allocate and release file read/write context information.
1103  */
1104 int nfs_open(struct inode *inode, struct file *filp)
1105 {
1106 	struct nfs_open_context *ctx;
1107 
1108 	ctx = alloc_nfs_open_context(file_dentry(filp), filp->f_mode, filp);
1109 	if (IS_ERR(ctx))
1110 		return PTR_ERR(ctx);
1111 	nfs_file_set_open_context(filp, ctx);
1112 	put_nfs_open_context(ctx);
1113 	nfs_fscache_open_file(inode, filp);
1114 	return 0;
1115 }
1116 EXPORT_SYMBOL_GPL(nfs_open);
1117 
1118 /*
1119  * This function is called whenever some part of NFS notices that
1120  * the cached attributes have to be refreshed.
1121  */
1122 int
1123 __nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
1124 {
1125 	int		 status = -ESTALE;
1126 	struct nfs4_label *label = NULL;
1127 	struct nfs_fattr *fattr = NULL;
1128 	struct nfs_inode *nfsi = NFS_I(inode);
1129 
1130 	dfprintk(PAGECACHE, "NFS: revalidating (%s/%Lu)\n",
1131 		inode->i_sb->s_id, (unsigned long long)NFS_FILEID(inode));
1132 
1133 	trace_nfs_revalidate_inode_enter(inode);
1134 
1135 	if (is_bad_inode(inode))
1136 		goto out;
1137 	if (NFS_STALE(inode))
1138 		goto out;
1139 
1140 	/* pNFS: Attributes aren't updated until we layoutcommit */
1141 	if (S_ISREG(inode->i_mode)) {
1142 		status = pnfs_sync_inode(inode, false);
1143 		if (status)
1144 			goto out;
1145 	}
1146 
1147 	status = -ENOMEM;
1148 	fattr = nfs_alloc_fattr();
1149 	if (fattr == NULL)
1150 		goto out;
1151 
1152 	nfs_inc_stats(inode, NFSIOS_INODEREVALIDATE);
1153 
1154 	label = nfs4_label_alloc(NFS_SERVER(inode), GFP_KERNEL);
1155 	if (IS_ERR(label)) {
1156 		status = PTR_ERR(label);
1157 		goto out;
1158 	}
1159 
1160 	status = NFS_PROTO(inode)->getattr(server, NFS_FH(inode), fattr,
1161 			label, inode);
1162 	if (status != 0) {
1163 		dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Lu) getattr failed, error=%d\n",
1164 			 inode->i_sb->s_id,
1165 			 (unsigned long long)NFS_FILEID(inode), status);
1166 		switch (status) {
1167 		case -ETIMEDOUT:
1168 			/* A soft timeout occurred. Use cached information? */
1169 			if (server->flags & NFS_MOUNT_SOFTREVAL)
1170 				status = 0;
1171 			break;
1172 		case -ESTALE:
1173 			if (!S_ISDIR(inode->i_mode))
1174 				nfs_set_inode_stale(inode);
1175 			else
1176 				nfs_zap_caches(inode);
1177 		}
1178 		goto err_out;
1179 	}
1180 
1181 	status = nfs_refresh_inode(inode, fattr);
1182 	if (status) {
1183 		dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Lu) refresh failed, error=%d\n",
1184 			 inode->i_sb->s_id,
1185 			 (unsigned long long)NFS_FILEID(inode), status);
1186 		goto err_out;
1187 	}
1188 
1189 	if (nfsi->cache_validity & NFS_INO_INVALID_ACL)
1190 		nfs_zap_acl_cache(inode);
1191 
1192 	nfs_setsecurity(inode, fattr, label);
1193 
1194 	dfprintk(PAGECACHE, "NFS: (%s/%Lu) revalidation complete\n",
1195 		inode->i_sb->s_id,
1196 		(unsigned long long)NFS_FILEID(inode));
1197 
1198 err_out:
1199 	nfs4_label_free(label);
1200 out:
1201 	nfs_free_fattr(fattr);
1202 	trace_nfs_revalidate_inode_exit(inode, status);
1203 	return status;
1204 }
1205 
1206 int nfs_attribute_cache_expired(struct inode *inode)
1207 {
1208 	if (nfs_have_delegated_attributes(inode))
1209 		return 0;
1210 	return nfs_attribute_timeout(inode);
1211 }
1212 
1213 /**
1214  * nfs_revalidate_inode - Revalidate the inode attributes
1215  * @server: pointer to nfs_server struct
1216  * @inode: pointer to inode struct
1217  *
1218  * Updates inode attribute information by retrieving the data from the server.
1219  */
1220 int nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
1221 {
1222 	if (!nfs_need_revalidate_inode(inode))
1223 		return NFS_STALE(inode) ? -ESTALE : 0;
1224 	return __nfs_revalidate_inode(server, inode);
1225 }
1226 EXPORT_SYMBOL_GPL(nfs_revalidate_inode);
1227 
1228 static int nfs_invalidate_mapping(struct inode *inode, struct address_space *mapping)
1229 {
1230 	struct nfs_inode *nfsi = NFS_I(inode);
1231 	int ret;
1232 
1233 	if (mapping->nrpages != 0) {
1234 		if (S_ISREG(inode->i_mode)) {
1235 			ret = nfs_sync_mapping(mapping);
1236 			if (ret < 0)
1237 				return ret;
1238 		}
1239 		ret = invalidate_inode_pages2(mapping);
1240 		if (ret < 0)
1241 			return ret;
1242 	}
1243 	if (S_ISDIR(inode->i_mode)) {
1244 		spin_lock(&inode->i_lock);
1245 		memset(nfsi->cookieverf, 0, sizeof(nfsi->cookieverf));
1246 		spin_unlock(&inode->i_lock);
1247 	}
1248 	nfs_inc_stats(inode, NFSIOS_DATAINVALIDATE);
1249 	nfs_fscache_wait_on_invalidate(inode);
1250 
1251 	dfprintk(PAGECACHE, "NFS: (%s/%Lu) data cache invalidated\n",
1252 			inode->i_sb->s_id,
1253 			(unsigned long long)NFS_FILEID(inode));
1254 	return 0;
1255 }
1256 
1257 bool nfs_mapping_need_revalidate_inode(struct inode *inode)
1258 {
1259 	return nfs_check_cache_invalid(inode, NFS_INO_REVAL_PAGECACHE) ||
1260 		NFS_STALE(inode);
1261 }
1262 
1263 int nfs_revalidate_mapping_rcu(struct inode *inode)
1264 {
1265 	struct nfs_inode *nfsi = NFS_I(inode);
1266 	unsigned long *bitlock = &nfsi->flags;
1267 	int ret = 0;
1268 
1269 	if (IS_SWAPFILE(inode))
1270 		goto out;
1271 	if (nfs_mapping_need_revalidate_inode(inode)) {
1272 		ret = -ECHILD;
1273 		goto out;
1274 	}
1275 	spin_lock(&inode->i_lock);
1276 	if (test_bit(NFS_INO_INVALIDATING, bitlock) ||
1277 	    (nfsi->cache_validity & NFS_INO_INVALID_DATA))
1278 		ret = -ECHILD;
1279 	spin_unlock(&inode->i_lock);
1280 out:
1281 	return ret;
1282 }
1283 
1284 /**
1285  * nfs_revalidate_mapping - Revalidate the pagecache
1286  * @inode: pointer to host inode
1287  * @mapping: pointer to mapping
1288  */
1289 int nfs_revalidate_mapping(struct inode *inode,
1290 		struct address_space *mapping)
1291 {
1292 	struct nfs_inode *nfsi = NFS_I(inode);
1293 	unsigned long *bitlock = &nfsi->flags;
1294 	int ret = 0;
1295 
1296 	/* swapfiles are not supposed to be shared. */
1297 	if (IS_SWAPFILE(inode))
1298 		goto out;
1299 
1300 	if (nfs_mapping_need_revalidate_inode(inode)) {
1301 		ret = __nfs_revalidate_inode(NFS_SERVER(inode), inode);
1302 		if (ret < 0)
1303 			goto out;
1304 	}
1305 
1306 	/*
1307 	 * We must clear NFS_INO_INVALID_DATA first to ensure that
1308 	 * invalidations that come in while we're shooting down the mappings
1309 	 * are respected. But, that leaves a race window where one revalidator
1310 	 * can clear the flag, and then another checks it before the mapping
1311 	 * gets invalidated. Fix that by serializing access to this part of
1312 	 * the function.
1313 	 *
1314 	 * At the same time, we need to allow other tasks to see whether we
1315 	 * might be in the middle of invalidating the pages, so we only set
1316 	 * the bit lock here if it looks like we're going to be doing that.
1317 	 */
1318 	for (;;) {
1319 		ret = wait_on_bit_action(bitlock, NFS_INO_INVALIDATING,
1320 					 nfs_wait_bit_killable, TASK_KILLABLE);
1321 		if (ret)
1322 			goto out;
1323 		spin_lock(&inode->i_lock);
1324 		if (test_bit(NFS_INO_INVALIDATING, bitlock)) {
1325 			spin_unlock(&inode->i_lock);
1326 			continue;
1327 		}
1328 		if (nfsi->cache_validity & NFS_INO_INVALID_DATA)
1329 			break;
1330 		spin_unlock(&inode->i_lock);
1331 		goto out;
1332 	}
1333 
1334 	set_bit(NFS_INO_INVALIDATING, bitlock);
1335 	smp_wmb();
1336 	nfsi->cache_validity &= ~(NFS_INO_INVALID_DATA|
1337 			NFS_INO_DATA_INVAL_DEFER);
1338 	spin_unlock(&inode->i_lock);
1339 	trace_nfs_invalidate_mapping_enter(inode);
1340 	ret = nfs_invalidate_mapping(inode, mapping);
1341 	trace_nfs_invalidate_mapping_exit(inode, ret);
1342 
1343 	clear_bit_unlock(NFS_INO_INVALIDATING, bitlock);
1344 	smp_mb__after_atomic();
1345 	wake_up_bit(bitlock, NFS_INO_INVALIDATING);
1346 out:
1347 	return ret;
1348 }
1349 
1350 static bool nfs_file_has_writers(struct nfs_inode *nfsi)
1351 {
1352 	struct inode *inode = &nfsi->vfs_inode;
1353 
1354 	if (!S_ISREG(inode->i_mode))
1355 		return false;
1356 	if (list_empty(&nfsi->open_files))
1357 		return false;
1358 	return inode_is_open_for_write(inode);
1359 }
1360 
1361 static bool nfs_file_has_buffered_writers(struct nfs_inode *nfsi)
1362 {
1363 	return nfs_file_has_writers(nfsi) && nfs_file_io_is_buffered(nfsi);
1364 }
1365 
1366 static void nfs_wcc_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1367 {
1368 	struct timespec64 ts;
1369 
1370 	if ((fattr->valid & NFS_ATTR_FATTR_PRECHANGE)
1371 			&& (fattr->valid & NFS_ATTR_FATTR_CHANGE)
1372 			&& inode_eq_iversion_raw(inode, fattr->pre_change_attr)) {
1373 		inode_set_iversion_raw(inode, fattr->change_attr);
1374 		if (S_ISDIR(inode->i_mode))
1375 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_DATA);
1376 	}
1377 	/* If we have atomic WCC data, we may update some attributes */
1378 	ts = inode->i_ctime;
1379 	if ((fattr->valid & NFS_ATTR_FATTR_PRECTIME)
1380 			&& (fattr->valid & NFS_ATTR_FATTR_CTIME)
1381 			&& timespec64_equal(&ts, &fattr->pre_ctime)) {
1382 		inode->i_ctime = fattr->ctime;
1383 	}
1384 
1385 	ts = inode->i_mtime;
1386 	if ((fattr->valid & NFS_ATTR_FATTR_PREMTIME)
1387 			&& (fattr->valid & NFS_ATTR_FATTR_MTIME)
1388 			&& timespec64_equal(&ts, &fattr->pre_mtime)) {
1389 		inode->i_mtime = fattr->mtime;
1390 		if (S_ISDIR(inode->i_mode))
1391 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_DATA);
1392 	}
1393 	if ((fattr->valid & NFS_ATTR_FATTR_PRESIZE)
1394 			&& (fattr->valid & NFS_ATTR_FATTR_SIZE)
1395 			&& i_size_read(inode) == nfs_size_to_loff_t(fattr->pre_size)
1396 			&& !nfs_have_writebacks(inode)) {
1397 		i_size_write(inode, nfs_size_to_loff_t(fattr->size));
1398 	}
1399 }
1400 
1401 /**
1402  * nfs_check_inode_attributes - verify consistency of the inode attribute cache
1403  * @inode: pointer to inode
1404  * @fattr: updated attributes
1405  *
1406  * Verifies the attribute cache. If we have just changed the attributes,
1407  * so that fattr carries weak cache consistency data, then it may
1408  * also update the ctime/mtime/change_attribute.
1409  */
1410 static int nfs_check_inode_attributes(struct inode *inode, struct nfs_fattr *fattr)
1411 {
1412 	struct nfs_inode *nfsi = NFS_I(inode);
1413 	loff_t cur_size, new_isize;
1414 	unsigned long invalid = 0;
1415 	struct timespec64 ts;
1416 
1417 	if (NFS_PROTO(inode)->have_delegation(inode, FMODE_READ))
1418 		return 0;
1419 
1420 	if (!(fattr->valid & NFS_ATTR_FATTR_FILEID)) {
1421 		/* Only a mounted-on-fileid? Just exit */
1422 		if (fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID)
1423 			return 0;
1424 	/* Has the inode gone and changed behind our back? */
1425 	} else if (nfsi->fileid != fattr->fileid) {
1426 		/* Is this perhaps the mounted-on fileid? */
1427 		if ((fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID) &&
1428 		    nfsi->fileid == fattr->mounted_on_fileid)
1429 			return 0;
1430 		return -ESTALE;
1431 	}
1432 	if ((fattr->valid & NFS_ATTR_FATTR_TYPE) && (inode->i_mode & S_IFMT) != (fattr->mode & S_IFMT))
1433 		return -ESTALE;
1434 
1435 
1436 	if (!nfs_file_has_buffered_writers(nfsi)) {
1437 		/* Verify a few of the more important attributes */
1438 		if ((fattr->valid & NFS_ATTR_FATTR_CHANGE) != 0 && !inode_eq_iversion_raw(inode, fattr->change_attr))
1439 			invalid |= NFS_INO_INVALID_CHANGE
1440 				| NFS_INO_REVAL_PAGECACHE;
1441 
1442 		ts = inode->i_mtime;
1443 		if ((fattr->valid & NFS_ATTR_FATTR_MTIME) && !timespec64_equal(&ts, &fattr->mtime))
1444 			invalid |= NFS_INO_INVALID_MTIME;
1445 
1446 		ts = inode->i_ctime;
1447 		if ((fattr->valid & NFS_ATTR_FATTR_CTIME) && !timespec64_equal(&ts, &fattr->ctime))
1448 			invalid |= NFS_INO_INVALID_CTIME;
1449 
1450 		if (fattr->valid & NFS_ATTR_FATTR_SIZE) {
1451 			cur_size = i_size_read(inode);
1452 			new_isize = nfs_size_to_loff_t(fattr->size);
1453 			if (cur_size != new_isize)
1454 				invalid |= NFS_INO_INVALID_SIZE
1455 					| NFS_INO_REVAL_PAGECACHE;
1456 		}
1457 	}
1458 
1459 	/* Have any file permissions changed? */
1460 	if ((fattr->valid & NFS_ATTR_FATTR_MODE) && (inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO))
1461 		invalid |= NFS_INO_INVALID_ACCESS
1462 			| NFS_INO_INVALID_ACL
1463 			| NFS_INO_INVALID_OTHER;
1464 	if ((fattr->valid & NFS_ATTR_FATTR_OWNER) && !uid_eq(inode->i_uid, fattr->uid))
1465 		invalid |= NFS_INO_INVALID_ACCESS
1466 			| NFS_INO_INVALID_ACL
1467 			| NFS_INO_INVALID_OTHER;
1468 	if ((fattr->valid & NFS_ATTR_FATTR_GROUP) && !gid_eq(inode->i_gid, fattr->gid))
1469 		invalid |= NFS_INO_INVALID_ACCESS
1470 			| NFS_INO_INVALID_ACL
1471 			| NFS_INO_INVALID_OTHER;
1472 
1473 	/* Has the link count changed? */
1474 	if ((fattr->valid & NFS_ATTR_FATTR_NLINK) && inode->i_nlink != fattr->nlink)
1475 		invalid |= NFS_INO_INVALID_OTHER;
1476 
1477 	ts = inode->i_atime;
1478 	if ((fattr->valid & NFS_ATTR_FATTR_ATIME) && !timespec64_equal(&ts, &fattr->atime))
1479 		invalid |= NFS_INO_INVALID_ATIME;
1480 
1481 	if (invalid != 0)
1482 		nfs_set_cache_invalid(inode, invalid);
1483 
1484 	nfsi->read_cache_jiffies = fattr->time_start;
1485 	return 0;
1486 }
1487 
1488 static atomic_long_t nfs_attr_generation_counter;
1489 
1490 static unsigned long nfs_read_attr_generation_counter(void)
1491 {
1492 	return atomic_long_read(&nfs_attr_generation_counter);
1493 }
1494 
1495 unsigned long nfs_inc_attr_generation_counter(void)
1496 {
1497 	return atomic_long_inc_return(&nfs_attr_generation_counter);
1498 }
1499 EXPORT_SYMBOL_GPL(nfs_inc_attr_generation_counter);
1500 
1501 void nfs_fattr_init(struct nfs_fattr *fattr)
1502 {
1503 	fattr->valid = 0;
1504 	fattr->time_start = jiffies;
1505 	fattr->gencount = nfs_inc_attr_generation_counter();
1506 	fattr->owner_name = NULL;
1507 	fattr->group_name = NULL;
1508 }
1509 EXPORT_SYMBOL_GPL(nfs_fattr_init);
1510 
1511 /**
1512  * nfs_fattr_set_barrier
1513  * @fattr: attributes
1514  *
1515  * Used to set a barrier after an attribute was updated. This
1516  * barrier ensures that older attributes from RPC calls that may
1517  * have raced with our update cannot clobber these new values.
1518  * Note that you are still responsible for ensuring that other
1519  * operations which change the attribute on the server do not
1520  * collide.
1521  */
1522 void nfs_fattr_set_barrier(struct nfs_fattr *fattr)
1523 {
1524 	fattr->gencount = nfs_inc_attr_generation_counter();
1525 }
1526 
1527 struct nfs_fattr *nfs_alloc_fattr(void)
1528 {
1529 	struct nfs_fattr *fattr;
1530 
1531 	fattr = kmalloc(sizeof(*fattr), GFP_NOFS);
1532 	if (fattr != NULL)
1533 		nfs_fattr_init(fattr);
1534 	return fattr;
1535 }
1536 EXPORT_SYMBOL_GPL(nfs_alloc_fattr);
1537 
1538 struct nfs_fh *nfs_alloc_fhandle(void)
1539 {
1540 	struct nfs_fh *fh;
1541 
1542 	fh = kmalloc(sizeof(struct nfs_fh), GFP_NOFS);
1543 	if (fh != NULL)
1544 		fh->size = 0;
1545 	return fh;
1546 }
1547 EXPORT_SYMBOL_GPL(nfs_alloc_fhandle);
1548 
1549 #ifdef NFS_DEBUG
1550 /*
1551  * _nfs_display_fhandle_hash - calculate the crc32 hash for the filehandle
1552  *                             in the same way that wireshark does
1553  *
1554  * @fh: file handle
1555  *
1556  * For debugging only.
1557  */
1558 u32 _nfs_display_fhandle_hash(const struct nfs_fh *fh)
1559 {
1560 	/* wireshark uses 32-bit AUTODIN crc and does a bitwise
1561 	 * not on the result */
1562 	return nfs_fhandle_hash(fh);
1563 }
1564 EXPORT_SYMBOL_GPL(_nfs_display_fhandle_hash);
1565 
1566 /*
1567  * _nfs_display_fhandle - display an NFS file handle on the console
1568  *
1569  * @fh: file handle to display
1570  * @caption: display caption
1571  *
1572  * For debugging only.
1573  */
1574 void _nfs_display_fhandle(const struct nfs_fh *fh, const char *caption)
1575 {
1576 	unsigned short i;
1577 
1578 	if (fh == NULL || fh->size == 0) {
1579 		printk(KERN_DEFAULT "%s at %p is empty\n", caption, fh);
1580 		return;
1581 	}
1582 
1583 	printk(KERN_DEFAULT "%s at %p is %u bytes, crc: 0x%08x:\n",
1584 	       caption, fh, fh->size, _nfs_display_fhandle_hash(fh));
1585 	for (i = 0; i < fh->size; i += 16) {
1586 		__be32 *pos = (__be32 *)&fh->data[i];
1587 
1588 		switch ((fh->size - i - 1) >> 2) {
1589 		case 0:
1590 			printk(KERN_DEFAULT " %08x\n",
1591 				be32_to_cpup(pos));
1592 			break;
1593 		case 1:
1594 			printk(KERN_DEFAULT " %08x %08x\n",
1595 				be32_to_cpup(pos), be32_to_cpup(pos + 1));
1596 			break;
1597 		case 2:
1598 			printk(KERN_DEFAULT " %08x %08x %08x\n",
1599 				be32_to_cpup(pos), be32_to_cpup(pos + 1),
1600 				be32_to_cpup(pos + 2));
1601 			break;
1602 		default:
1603 			printk(KERN_DEFAULT " %08x %08x %08x %08x\n",
1604 				be32_to_cpup(pos), be32_to_cpup(pos + 1),
1605 				be32_to_cpup(pos + 2), be32_to_cpup(pos + 3));
1606 		}
1607 	}
1608 }
1609 EXPORT_SYMBOL_GPL(_nfs_display_fhandle);
1610 #endif
1611 
1612 /**
1613  * nfs_inode_attrs_need_update - check if the inode attributes need updating
1614  * @inode: pointer to inode
1615  * @fattr: attributes
1616  *
1617  * Attempt to divine whether or not an RPC call reply carrying stale
1618  * attributes got scheduled after another call carrying updated ones.
1619  *
1620  * To do so, the function first assumes that a more recent ctime means
1621  * that the attributes in fattr are newer, however it also attempt to
1622  * catch the case where ctime either didn't change, or went backwards
1623  * (if someone reset the clock on the server) by looking at whether
1624  * or not this RPC call was started after the inode was last updated.
1625  * Note also the check for wraparound of 'attr_gencount'
1626  *
1627  * The function returns 'true' if it thinks the attributes in 'fattr' are
1628  * more recent than the ones cached in the inode.
1629  *
1630  */
1631 static int nfs_inode_attrs_need_update(const struct inode *inode, const struct nfs_fattr *fattr)
1632 {
1633 	const struct nfs_inode *nfsi = NFS_I(inode);
1634 
1635 	return ((long)fattr->gencount - (long)nfsi->attr_gencount) > 0 ||
1636 		((long)nfsi->attr_gencount - (long)nfs_read_attr_generation_counter() > 0);
1637 }
1638 
1639 static int nfs_refresh_inode_locked(struct inode *inode, struct nfs_fattr *fattr)
1640 {
1641 	int ret;
1642 
1643 	trace_nfs_refresh_inode_enter(inode);
1644 
1645 	if (nfs_inode_attrs_need_update(inode, fattr))
1646 		ret = nfs_update_inode(inode, fattr);
1647 	else
1648 		ret = nfs_check_inode_attributes(inode, fattr);
1649 
1650 	trace_nfs_refresh_inode_exit(inode, ret);
1651 	return ret;
1652 }
1653 
1654 /**
1655  * nfs_refresh_inode - try to update the inode attribute cache
1656  * @inode: pointer to inode
1657  * @fattr: updated attributes
1658  *
1659  * Check that an RPC call that returned attributes has not overlapped with
1660  * other recent updates of the inode metadata, then decide whether it is
1661  * safe to do a full update of the inode attributes, or whether just to
1662  * call nfs_check_inode_attributes.
1663  */
1664 int nfs_refresh_inode(struct inode *inode, struct nfs_fattr *fattr)
1665 {
1666 	int status;
1667 
1668 	if ((fattr->valid & NFS_ATTR_FATTR) == 0)
1669 		return 0;
1670 	spin_lock(&inode->i_lock);
1671 	status = nfs_refresh_inode_locked(inode, fattr);
1672 	spin_unlock(&inode->i_lock);
1673 
1674 	return status;
1675 }
1676 EXPORT_SYMBOL_GPL(nfs_refresh_inode);
1677 
1678 static int nfs_post_op_update_inode_locked(struct inode *inode,
1679 		struct nfs_fattr *fattr, unsigned int invalid)
1680 {
1681 	if (S_ISDIR(inode->i_mode))
1682 		invalid |= NFS_INO_INVALID_DATA;
1683 	nfs_set_cache_invalid(inode, invalid);
1684 	if ((fattr->valid & NFS_ATTR_FATTR) == 0)
1685 		return 0;
1686 	return nfs_refresh_inode_locked(inode, fattr);
1687 }
1688 
1689 /**
1690  * nfs_post_op_update_inode - try to update the inode attribute cache
1691  * @inode: pointer to inode
1692  * @fattr: updated attributes
1693  *
1694  * After an operation that has changed the inode metadata, mark the
1695  * attribute cache as being invalid, then try to update it.
1696  *
1697  * NB: if the server didn't return any post op attributes, this
1698  * function will force the retrieval of attributes before the next
1699  * NFS request.  Thus it should be used only for operations that
1700  * are expected to change one or more attributes, to avoid
1701  * unnecessary NFS requests and trips through nfs_update_inode().
1702  */
1703 int nfs_post_op_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1704 {
1705 	int status;
1706 
1707 	spin_lock(&inode->i_lock);
1708 	nfs_fattr_set_barrier(fattr);
1709 	status = nfs_post_op_update_inode_locked(inode, fattr,
1710 			NFS_INO_INVALID_CHANGE
1711 			| NFS_INO_INVALID_CTIME
1712 			| NFS_INO_REVAL_FORCED);
1713 	spin_unlock(&inode->i_lock);
1714 
1715 	return status;
1716 }
1717 EXPORT_SYMBOL_GPL(nfs_post_op_update_inode);
1718 
1719 /**
1720  * nfs_post_op_update_inode_force_wcc_locked - update the inode attribute cache
1721  * @inode: pointer to inode
1722  * @fattr: updated attributes
1723  *
1724  * After an operation that has changed the inode metadata, mark the
1725  * attribute cache as being invalid, then try to update it. Fake up
1726  * weak cache consistency data, if none exist.
1727  *
1728  * This function is mainly designed to be used by the ->write_done() functions.
1729  */
1730 int nfs_post_op_update_inode_force_wcc_locked(struct inode *inode, struct nfs_fattr *fattr)
1731 {
1732 	int status;
1733 
1734 	/* Don't do a WCC update if these attributes are already stale */
1735 	if ((fattr->valid & NFS_ATTR_FATTR) == 0 ||
1736 			!nfs_inode_attrs_need_update(inode, fattr)) {
1737 		fattr->valid &= ~(NFS_ATTR_FATTR_PRECHANGE
1738 				| NFS_ATTR_FATTR_PRESIZE
1739 				| NFS_ATTR_FATTR_PREMTIME
1740 				| NFS_ATTR_FATTR_PRECTIME);
1741 		goto out_noforce;
1742 	}
1743 	if ((fattr->valid & NFS_ATTR_FATTR_CHANGE) != 0 &&
1744 			(fattr->valid & NFS_ATTR_FATTR_PRECHANGE) == 0) {
1745 		fattr->pre_change_attr = inode_peek_iversion_raw(inode);
1746 		fattr->valid |= NFS_ATTR_FATTR_PRECHANGE;
1747 	}
1748 	if ((fattr->valid & NFS_ATTR_FATTR_CTIME) != 0 &&
1749 			(fattr->valid & NFS_ATTR_FATTR_PRECTIME) == 0) {
1750 		fattr->pre_ctime = inode->i_ctime;
1751 		fattr->valid |= NFS_ATTR_FATTR_PRECTIME;
1752 	}
1753 	if ((fattr->valid & NFS_ATTR_FATTR_MTIME) != 0 &&
1754 			(fattr->valid & NFS_ATTR_FATTR_PREMTIME) == 0) {
1755 		fattr->pre_mtime = inode->i_mtime;
1756 		fattr->valid |= NFS_ATTR_FATTR_PREMTIME;
1757 	}
1758 	if ((fattr->valid & NFS_ATTR_FATTR_SIZE) != 0 &&
1759 			(fattr->valid & NFS_ATTR_FATTR_PRESIZE) == 0) {
1760 		fattr->pre_size = i_size_read(inode);
1761 		fattr->valid |= NFS_ATTR_FATTR_PRESIZE;
1762 	}
1763 out_noforce:
1764 	status = nfs_post_op_update_inode_locked(inode, fattr,
1765 			NFS_INO_INVALID_CHANGE
1766 			| NFS_INO_INVALID_CTIME
1767 			| NFS_INO_INVALID_MTIME);
1768 	return status;
1769 }
1770 
1771 /**
1772  * nfs_post_op_update_inode_force_wcc - try to update the inode attribute cache
1773  * @inode: pointer to inode
1774  * @fattr: updated attributes
1775  *
1776  * After an operation that has changed the inode metadata, mark the
1777  * attribute cache as being invalid, then try to update it. Fake up
1778  * weak cache consistency data, if none exist.
1779  *
1780  * This function is mainly designed to be used by the ->write_done() functions.
1781  */
1782 int nfs_post_op_update_inode_force_wcc(struct inode *inode, struct nfs_fattr *fattr)
1783 {
1784 	int status;
1785 
1786 	spin_lock(&inode->i_lock);
1787 	nfs_fattr_set_barrier(fattr);
1788 	status = nfs_post_op_update_inode_force_wcc_locked(inode, fattr);
1789 	spin_unlock(&inode->i_lock);
1790 	return status;
1791 }
1792 EXPORT_SYMBOL_GPL(nfs_post_op_update_inode_force_wcc);
1793 
1794 
1795 /*
1796  * Many nfs protocol calls return the new file attributes after
1797  * an operation.  Here we update the inode to reflect the state
1798  * of the server's inode.
1799  *
1800  * This is a bit tricky because we have to make sure all dirty pages
1801  * have been sent off to the server before calling invalidate_inode_pages.
1802  * To make sure no other process adds more write requests while we try
1803  * our best to flush them, we make them sleep during the attribute refresh.
1804  *
1805  * A very similar scenario holds for the dir cache.
1806  */
1807 static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1808 {
1809 	struct nfs_server *server;
1810 	struct nfs_inode *nfsi = NFS_I(inode);
1811 	loff_t cur_isize, new_isize;
1812 	unsigned long invalid = 0;
1813 	unsigned long now = jiffies;
1814 	unsigned long save_cache_validity;
1815 	bool have_writers = nfs_file_has_buffered_writers(nfsi);
1816 	bool cache_revalidated = true;
1817 	bool attr_changed = false;
1818 	bool have_delegation;
1819 
1820 	dfprintk(VFS, "NFS: %s(%s/%lu fh_crc=0x%08x ct=%d info=0x%x)\n",
1821 			__func__, inode->i_sb->s_id, inode->i_ino,
1822 			nfs_display_fhandle_hash(NFS_FH(inode)),
1823 			atomic_read(&inode->i_count), fattr->valid);
1824 
1825 	if (!(fattr->valid & NFS_ATTR_FATTR_FILEID)) {
1826 		/* Only a mounted-on-fileid? Just exit */
1827 		if (fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID)
1828 			return 0;
1829 	/* Has the inode gone and changed behind our back? */
1830 	} else if (nfsi->fileid != fattr->fileid) {
1831 		/* Is this perhaps the mounted-on fileid? */
1832 		if ((fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID) &&
1833 		    nfsi->fileid == fattr->mounted_on_fileid)
1834 			return 0;
1835 		printk(KERN_ERR "NFS: server %s error: fileid changed\n"
1836 			"fsid %s: expected fileid 0x%Lx, got 0x%Lx\n",
1837 			NFS_SERVER(inode)->nfs_client->cl_hostname,
1838 			inode->i_sb->s_id, (long long)nfsi->fileid,
1839 			(long long)fattr->fileid);
1840 		goto out_err;
1841 	}
1842 
1843 	/*
1844 	 * Make sure the inode's type hasn't changed.
1845 	 */
1846 	if ((fattr->valid & NFS_ATTR_FATTR_TYPE) && (inode->i_mode & S_IFMT) != (fattr->mode & S_IFMT)) {
1847 		/*
1848 		* Big trouble! The inode has become a different object.
1849 		*/
1850 		printk(KERN_DEBUG "NFS: %s: inode %lu mode changed, %07o to %07o\n",
1851 				__func__, inode->i_ino, inode->i_mode, fattr->mode);
1852 		goto out_err;
1853 	}
1854 
1855 	server = NFS_SERVER(inode);
1856 	/* Update the fsid? */
1857 	if (S_ISDIR(inode->i_mode) && (fattr->valid & NFS_ATTR_FATTR_FSID) &&
1858 			!nfs_fsid_equal(&server->fsid, &fattr->fsid) &&
1859 			!IS_AUTOMOUNT(inode))
1860 		server->fsid = fattr->fsid;
1861 
1862 	/* Save the delegation state before clearing cache_validity */
1863 	have_delegation = nfs_have_delegated_attributes(inode);
1864 
1865 	/*
1866 	 * Update the read time so we don't revalidate too often.
1867 	 */
1868 	nfsi->read_cache_jiffies = fattr->time_start;
1869 
1870 	save_cache_validity = nfsi->cache_validity;
1871 	nfsi->cache_validity &= ~(NFS_INO_INVALID_ATTR
1872 			| NFS_INO_INVALID_ATIME
1873 			| NFS_INO_REVAL_FORCED
1874 			| NFS_INO_REVAL_PAGECACHE);
1875 
1876 	/* Do atomic weak cache consistency updates */
1877 	nfs_wcc_update_inode(inode, fattr);
1878 
1879 	if (pnfs_layoutcommit_outstanding(inode)) {
1880 		nfsi->cache_validity |= save_cache_validity & NFS_INO_INVALID_ATTR;
1881 		cache_revalidated = false;
1882 	}
1883 
1884 	/* More cache consistency checks */
1885 	if (fattr->valid & NFS_ATTR_FATTR_CHANGE) {
1886 		if (!inode_eq_iversion_raw(inode, fattr->change_attr)) {
1887 			/* Could it be a race with writeback? */
1888 			if (!(have_writers || have_delegation)) {
1889 				invalid |= NFS_INO_INVALID_DATA
1890 					| NFS_INO_INVALID_ACCESS
1891 					| NFS_INO_INVALID_ACL;
1892 				/* Force revalidate of all attributes */
1893 				save_cache_validity |= NFS_INO_INVALID_CTIME
1894 					| NFS_INO_INVALID_MTIME
1895 					| NFS_INO_INVALID_SIZE
1896 					| NFS_INO_INVALID_OTHER;
1897 				if (S_ISDIR(inode->i_mode))
1898 					nfs_force_lookup_revalidate(inode);
1899 				dprintk("NFS: change_attr change on server for file %s/%ld\n",
1900 						inode->i_sb->s_id,
1901 						inode->i_ino);
1902 			} else if (!have_delegation)
1903 				nfsi->cache_validity |= NFS_INO_DATA_INVAL_DEFER;
1904 			inode_set_iversion_raw(inode, fattr->change_attr);
1905 			attr_changed = true;
1906 		}
1907 	} else {
1908 		nfsi->cache_validity |= save_cache_validity &
1909 				(NFS_INO_INVALID_CHANGE
1910 				| NFS_INO_REVAL_PAGECACHE
1911 				| NFS_INO_REVAL_FORCED);
1912 		cache_revalidated = false;
1913 	}
1914 
1915 	if (fattr->valid & NFS_ATTR_FATTR_MTIME) {
1916 		inode->i_mtime = fattr->mtime;
1917 	} else if (server->caps & NFS_CAP_MTIME) {
1918 		nfsi->cache_validity |= save_cache_validity &
1919 				(NFS_INO_INVALID_MTIME
1920 				| NFS_INO_REVAL_FORCED);
1921 		cache_revalidated = false;
1922 	}
1923 
1924 	if (fattr->valid & NFS_ATTR_FATTR_CTIME) {
1925 		inode->i_ctime = fattr->ctime;
1926 	} else if (server->caps & NFS_CAP_CTIME) {
1927 		nfsi->cache_validity |= save_cache_validity &
1928 				(NFS_INO_INVALID_CTIME
1929 				| NFS_INO_REVAL_FORCED);
1930 		cache_revalidated = false;
1931 	}
1932 
1933 	/* Check if our cached file size is stale */
1934 	if (fattr->valid & NFS_ATTR_FATTR_SIZE) {
1935 		new_isize = nfs_size_to_loff_t(fattr->size);
1936 		cur_isize = i_size_read(inode);
1937 		if (new_isize != cur_isize && !have_delegation) {
1938 			/* Do we perhaps have any outstanding writes, or has
1939 			 * the file grown beyond our last write? */
1940 			if (!nfs_have_writebacks(inode) || new_isize > cur_isize) {
1941 				i_size_write(inode, new_isize);
1942 				if (!have_writers)
1943 					invalid |= NFS_INO_INVALID_DATA;
1944 				attr_changed = true;
1945 			}
1946 			dprintk("NFS: isize change on server for file %s/%ld "
1947 					"(%Ld to %Ld)\n",
1948 					inode->i_sb->s_id,
1949 					inode->i_ino,
1950 					(long long)cur_isize,
1951 					(long long)new_isize);
1952 		}
1953 	} else {
1954 		nfsi->cache_validity |= save_cache_validity &
1955 				(NFS_INO_INVALID_SIZE
1956 				| NFS_INO_REVAL_PAGECACHE
1957 				| NFS_INO_REVAL_FORCED);
1958 		cache_revalidated = false;
1959 	}
1960 
1961 
1962 	if (fattr->valid & NFS_ATTR_FATTR_ATIME)
1963 		inode->i_atime = fattr->atime;
1964 	else if (server->caps & NFS_CAP_ATIME) {
1965 		nfsi->cache_validity |= save_cache_validity &
1966 				(NFS_INO_INVALID_ATIME
1967 				| NFS_INO_REVAL_FORCED);
1968 		cache_revalidated = false;
1969 	}
1970 
1971 	if (fattr->valid & NFS_ATTR_FATTR_MODE) {
1972 		if ((inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO)) {
1973 			umode_t newmode = inode->i_mode & S_IFMT;
1974 			newmode |= fattr->mode & S_IALLUGO;
1975 			inode->i_mode = newmode;
1976 			invalid |= NFS_INO_INVALID_ACCESS
1977 				| NFS_INO_INVALID_ACL;
1978 			attr_changed = true;
1979 		}
1980 	} else if (server->caps & NFS_CAP_MODE) {
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_OWNER) {
1988 		if (!uid_eq(inode->i_uid, fattr->uid)) {
1989 			invalid |= NFS_INO_INVALID_ACCESS
1990 				| NFS_INO_INVALID_ACL;
1991 			inode->i_uid = fattr->uid;
1992 			attr_changed = true;
1993 		}
1994 	} else if (server->caps & NFS_CAP_OWNER) {
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_GROUP) {
2002 		if (!gid_eq(inode->i_gid, fattr->gid)) {
2003 			invalid |= NFS_INO_INVALID_ACCESS
2004 				| NFS_INO_INVALID_ACL;
2005 			inode->i_gid = fattr->gid;
2006 			attr_changed = true;
2007 		}
2008 	} else if (server->caps & NFS_CAP_OWNER_GROUP) {
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_NLINK) {
2016 		if (inode->i_nlink != fattr->nlink) {
2017 			if (S_ISDIR(inode->i_mode))
2018 				invalid |= NFS_INO_INVALID_DATA;
2019 			set_nlink(inode, fattr->nlink);
2020 			attr_changed = true;
2021 		}
2022 	} else if (server->caps & NFS_CAP_NLINK) {
2023 		nfsi->cache_validity |= save_cache_validity &
2024 				(NFS_INO_INVALID_OTHER
2025 				| NFS_INO_REVAL_FORCED);
2026 		cache_revalidated = false;
2027 	}
2028 
2029 	if (fattr->valid & NFS_ATTR_FATTR_SPACE_USED) {
2030 		/*
2031 		 * report the blocks in 512byte units
2032 		 */
2033 		inode->i_blocks = nfs_calc_block_size(fattr->du.nfs3.used);
2034 	} else if (fattr->valid & NFS_ATTR_FATTR_BLOCKS_USED)
2035 		inode->i_blocks = fattr->du.nfs2.blocks;
2036 	else
2037 		cache_revalidated = false;
2038 
2039 	/* Update attrtimeo value if we're out of the unstable period */
2040 	if (attr_changed) {
2041 		invalid &= ~NFS_INO_INVALID_ATTR;
2042 		nfs_inc_stats(inode, NFSIOS_ATTRINVALIDATE);
2043 		nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
2044 		nfsi->attrtimeo_timestamp = now;
2045 		/* Set barrier to be more recent than all outstanding updates */
2046 		nfsi->attr_gencount = nfs_inc_attr_generation_counter();
2047 	} else {
2048 		if (cache_revalidated) {
2049 			if (!time_in_range_open(now, nfsi->attrtimeo_timestamp,
2050 				nfsi->attrtimeo_timestamp + nfsi->attrtimeo)) {
2051 				nfsi->attrtimeo <<= 1;
2052 				if (nfsi->attrtimeo > NFS_MAXATTRTIMEO(inode))
2053 					nfsi->attrtimeo = NFS_MAXATTRTIMEO(inode);
2054 			}
2055 			nfsi->attrtimeo_timestamp = now;
2056 		}
2057 		/* Set the barrier to be more recent than this fattr */
2058 		if ((long)fattr->gencount - (long)nfsi->attr_gencount > 0)
2059 			nfsi->attr_gencount = fattr->gencount;
2060 	}
2061 
2062 	/* Don't invalidate the data if we were to blame */
2063 	if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)
2064 				|| S_ISLNK(inode->i_mode)))
2065 		invalid &= ~NFS_INO_INVALID_DATA;
2066 	nfs_set_cache_invalid(inode, invalid);
2067 
2068 	return 0;
2069  out_err:
2070 	/*
2071 	 * No need to worry about unhashing the dentry, as the
2072 	 * lookup validation will know that the inode is bad.
2073 	 * (But we fall through to invalidate the caches.)
2074 	 */
2075 	nfs_set_inode_stale_locked(inode);
2076 	return -ESTALE;
2077 }
2078 
2079 struct inode *nfs_alloc_inode(struct super_block *sb)
2080 {
2081 	struct nfs_inode *nfsi;
2082 	nfsi = kmem_cache_alloc(nfs_inode_cachep, GFP_KERNEL);
2083 	if (!nfsi)
2084 		return NULL;
2085 	nfsi->flags = 0UL;
2086 	nfsi->cache_validity = 0UL;
2087 #if IS_ENABLED(CONFIG_NFS_V4)
2088 	nfsi->nfs4_acl = NULL;
2089 #endif /* CONFIG_NFS_V4 */
2090 	return &nfsi->vfs_inode;
2091 }
2092 EXPORT_SYMBOL_GPL(nfs_alloc_inode);
2093 
2094 void nfs_free_inode(struct inode *inode)
2095 {
2096 	kmem_cache_free(nfs_inode_cachep, NFS_I(inode));
2097 }
2098 EXPORT_SYMBOL_GPL(nfs_free_inode);
2099 
2100 static inline void nfs4_init_once(struct nfs_inode *nfsi)
2101 {
2102 #if IS_ENABLED(CONFIG_NFS_V4)
2103 	INIT_LIST_HEAD(&nfsi->open_states);
2104 	nfsi->delegation = NULL;
2105 	init_rwsem(&nfsi->rwsem);
2106 	nfsi->layout = NULL;
2107 #endif
2108 }
2109 
2110 static void init_once(void *foo)
2111 {
2112 	struct nfs_inode *nfsi = (struct nfs_inode *) foo;
2113 
2114 	inode_init_once(&nfsi->vfs_inode);
2115 	INIT_LIST_HEAD(&nfsi->open_files);
2116 	INIT_LIST_HEAD(&nfsi->access_cache_entry_lru);
2117 	INIT_LIST_HEAD(&nfsi->access_cache_inode_lru);
2118 	INIT_LIST_HEAD(&nfsi->commit_info.list);
2119 	atomic_long_set(&nfsi->nrequests, 0);
2120 	atomic_long_set(&nfsi->commit_info.ncommit, 0);
2121 	atomic_set(&nfsi->commit_info.rpcs_out, 0);
2122 	init_rwsem(&nfsi->rmdir_sem);
2123 	mutex_init(&nfsi->commit_mutex);
2124 	nfs4_init_once(nfsi);
2125 	nfsi->cache_change_attribute = 0;
2126 }
2127 
2128 static int __init nfs_init_inodecache(void)
2129 {
2130 	nfs_inode_cachep = kmem_cache_create("nfs_inode_cache",
2131 					     sizeof(struct nfs_inode),
2132 					     0, (SLAB_RECLAIM_ACCOUNT|
2133 						SLAB_MEM_SPREAD|SLAB_ACCOUNT),
2134 					     init_once);
2135 	if (nfs_inode_cachep == NULL)
2136 		return -ENOMEM;
2137 
2138 	return 0;
2139 }
2140 
2141 static void nfs_destroy_inodecache(void)
2142 {
2143 	/*
2144 	 * Make sure all delayed rcu free inodes are flushed before we
2145 	 * destroy cache.
2146 	 */
2147 	rcu_barrier();
2148 	kmem_cache_destroy(nfs_inode_cachep);
2149 }
2150 
2151 struct workqueue_struct *nfsiod_workqueue;
2152 EXPORT_SYMBOL_GPL(nfsiod_workqueue);
2153 
2154 /*
2155  * start up the nfsiod workqueue
2156  */
2157 static int nfsiod_start(void)
2158 {
2159 	struct workqueue_struct *wq;
2160 	dprintk("RPC:       creating workqueue nfsiod\n");
2161 	wq = alloc_workqueue("nfsiod", WQ_MEM_RECLAIM, 0);
2162 	if (wq == NULL)
2163 		return -ENOMEM;
2164 	nfsiod_workqueue = wq;
2165 	return 0;
2166 }
2167 
2168 /*
2169  * Destroy the nfsiod workqueue
2170  */
2171 static void nfsiod_stop(void)
2172 {
2173 	struct workqueue_struct *wq;
2174 
2175 	wq = nfsiod_workqueue;
2176 	if (wq == NULL)
2177 		return;
2178 	nfsiod_workqueue = NULL;
2179 	destroy_workqueue(wq);
2180 }
2181 
2182 unsigned int nfs_net_id;
2183 EXPORT_SYMBOL_GPL(nfs_net_id);
2184 
2185 static int nfs_net_init(struct net *net)
2186 {
2187 	nfs_clients_init(net);
2188 	return nfs_fs_proc_net_init(net);
2189 }
2190 
2191 static void nfs_net_exit(struct net *net)
2192 {
2193 	nfs_fs_proc_net_exit(net);
2194 	nfs_clients_exit(net);
2195 }
2196 
2197 static struct pernet_operations nfs_net_ops = {
2198 	.init = nfs_net_init,
2199 	.exit = nfs_net_exit,
2200 	.id   = &nfs_net_id,
2201 	.size = sizeof(struct nfs_net),
2202 };
2203 
2204 /*
2205  * Initialize NFS
2206  */
2207 static int __init init_nfs_fs(void)
2208 {
2209 	int err;
2210 
2211 	err = nfs_sysfs_init();
2212 	if (err < 0)
2213 		goto out10;
2214 
2215 	err = register_pernet_subsys(&nfs_net_ops);
2216 	if (err < 0)
2217 		goto out9;
2218 
2219 	err = nfs_fscache_register();
2220 	if (err < 0)
2221 		goto out8;
2222 
2223 	err = nfsiod_start();
2224 	if (err)
2225 		goto out7;
2226 
2227 	err = nfs_fs_proc_init();
2228 	if (err)
2229 		goto out6;
2230 
2231 	err = nfs_init_nfspagecache();
2232 	if (err)
2233 		goto out5;
2234 
2235 	err = nfs_init_inodecache();
2236 	if (err)
2237 		goto out4;
2238 
2239 	err = nfs_init_readpagecache();
2240 	if (err)
2241 		goto out3;
2242 
2243 	err = nfs_init_writepagecache();
2244 	if (err)
2245 		goto out2;
2246 
2247 	err = nfs_init_directcache();
2248 	if (err)
2249 		goto out1;
2250 
2251 	rpc_proc_register(&init_net, &nfs_rpcstat);
2252 
2253 	err = register_nfs_fs();
2254 	if (err)
2255 		goto out0;
2256 
2257 	return 0;
2258 out0:
2259 	rpc_proc_unregister(&init_net, "nfs");
2260 	nfs_destroy_directcache();
2261 out1:
2262 	nfs_destroy_writepagecache();
2263 out2:
2264 	nfs_destroy_readpagecache();
2265 out3:
2266 	nfs_destroy_inodecache();
2267 out4:
2268 	nfs_destroy_nfspagecache();
2269 out5:
2270 	nfs_fs_proc_exit();
2271 out6:
2272 	nfsiod_stop();
2273 out7:
2274 	nfs_fscache_unregister();
2275 out8:
2276 	unregister_pernet_subsys(&nfs_net_ops);
2277 out9:
2278 	nfs_sysfs_exit();
2279 out10:
2280 	return err;
2281 }
2282 
2283 static void __exit exit_nfs_fs(void)
2284 {
2285 	nfs_destroy_directcache();
2286 	nfs_destroy_writepagecache();
2287 	nfs_destroy_readpagecache();
2288 	nfs_destroy_inodecache();
2289 	nfs_destroy_nfspagecache();
2290 	nfs_fscache_unregister();
2291 	unregister_pernet_subsys(&nfs_net_ops);
2292 	rpc_proc_unregister(&init_net, "nfs");
2293 	unregister_nfs_fs();
2294 	nfs_fs_proc_exit();
2295 	nfsiod_stop();
2296 	nfs_sysfs_exit();
2297 }
2298 
2299 /* Not quite true; I just maintain it */
2300 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
2301 MODULE_LICENSE("GPL");
2302 module_param(enable_ino64, bool, 0644);
2303 
2304 module_init(init_nfs_fs)
2305 module_exit(exit_nfs_fs)
2306