xref: /openbmc/linux/fs/nfs/inode.c (revision 763f96944c954ce0e00a10a7bdfe29adbe4f92eb)
1 /*
2  *  linux/fs/nfs/inode.c
3  *
4  *  Copyright (C) 1992  Rick Sladkey
5  *
6  *  nfs inode and superblock handling functions
7  *
8  *  Modularised by Alan Cox <alan@lxorguk.ukuu.org.uk>, while hacking some
9  *  experimental NFS changes. Modularisation taken straight from SYS5 fs.
10  *
11  *  Change to nfs_read_super() to permit NFS mounts to multi-homed hosts.
12  *  J.S.Peatfield@damtp.cam.ac.uk
13  *
14  */
15 
16 #include <linux/module.h>
17 #include <linux/init.h>
18 #include <linux/sched/signal.h>
19 #include <linux/time.h>
20 #include <linux/kernel.h>
21 #include <linux/mm.h>
22 #include <linux/string.h>
23 #include <linux/stat.h>
24 #include <linux/errno.h>
25 #include <linux/unistd.h>
26 #include <linux/sunrpc/clnt.h>
27 #include <linux/sunrpc/stats.h>
28 #include <linux/sunrpc/metrics.h>
29 #include <linux/nfs_fs.h>
30 #include <linux/nfs_mount.h>
31 #include <linux/nfs4_mount.h>
32 #include <linux/lockd/bind.h>
33 #include <linux/seq_file.h>
34 #include <linux/mount.h>
35 #include <linux/vfs.h>
36 #include <linux/inet.h>
37 #include <linux/nfs_xdr.h>
38 #include <linux/slab.h>
39 #include <linux/compat.h>
40 #include <linux/freezer.h>
41 #include <linux/uaccess.h>
42 #include <linux/iversion.h>
43 
44 #include "nfs4_fs.h"
45 #include "callback.h"
46 #include "delegation.h"
47 #include "iostat.h"
48 #include "internal.h"
49 #include "fscache.h"
50 #include "pnfs.h"
51 #include "nfs.h"
52 #include "netns.h"
53 
54 #include "nfstrace.h"
55 
56 #define NFSDBG_FACILITY		NFSDBG_VFS
57 
58 #define NFS_64_BIT_INODE_NUMBERS_ENABLED	1
59 
60 /* Default is to see 64-bit inode numbers */
61 static bool enable_ino64 = NFS_64_BIT_INODE_NUMBERS_ENABLED;
62 
63 static void nfs_invalidate_inode(struct inode *);
64 static int nfs_update_inode(struct inode *, struct nfs_fattr *);
65 
66 static struct kmem_cache * nfs_inode_cachep;
67 
68 static inline unsigned long
69 nfs_fattr_to_ino_t(struct nfs_fattr *fattr)
70 {
71 	return nfs_fileid_to_ino_t(fattr->fileid);
72 }
73 
74 static int nfs_wait_killable(int mode)
75 {
76 	freezable_schedule_unsafe();
77 	if (signal_pending_state(mode, current))
78 		return -ERESTARTSYS;
79 	return 0;
80 }
81 
82 int nfs_wait_bit_killable(struct wait_bit_key *key, int mode)
83 {
84 	return nfs_wait_killable(mode);
85 }
86 EXPORT_SYMBOL_GPL(nfs_wait_bit_killable);
87 
88 /**
89  * nfs_compat_user_ino64 - returns the user-visible inode number
90  * @fileid: 64-bit fileid
91  *
92  * This function returns a 32-bit inode number if the boot parameter
93  * nfs.enable_ino64 is zero.
94  */
95 u64 nfs_compat_user_ino64(u64 fileid)
96 {
97 #ifdef CONFIG_COMPAT
98 	compat_ulong_t ino;
99 #else
100 	unsigned long ino;
101 #endif
102 
103 	if (enable_ino64)
104 		return fileid;
105 	ino = fileid;
106 	if (sizeof(ino) < sizeof(fileid))
107 		ino ^= fileid >> (sizeof(fileid)-sizeof(ino)) * 8;
108 	return ino;
109 }
110 
111 int nfs_drop_inode(struct inode *inode)
112 {
113 	return NFS_STALE(inode) || generic_drop_inode(inode);
114 }
115 EXPORT_SYMBOL_GPL(nfs_drop_inode);
116 
117 void nfs_clear_inode(struct inode *inode)
118 {
119 	/*
120 	 * The following should never happen...
121 	 */
122 	WARN_ON_ONCE(nfs_have_writebacks(inode));
123 	WARN_ON_ONCE(!list_empty(&NFS_I(inode)->open_files));
124 	nfs_zap_acl_cache(inode);
125 	nfs_access_zap_cache(inode);
126 	nfs_fscache_clear_inode(inode);
127 }
128 EXPORT_SYMBOL_GPL(nfs_clear_inode);
129 
130 void nfs_evict_inode(struct inode *inode)
131 {
132 	truncate_inode_pages_final(&inode->i_data);
133 	clear_inode(inode);
134 	nfs_clear_inode(inode);
135 }
136 
137 int nfs_sync_inode(struct inode *inode)
138 {
139 	inode_dio_wait(inode);
140 	return nfs_wb_all(inode);
141 }
142 EXPORT_SYMBOL_GPL(nfs_sync_inode);
143 
144 /**
145  * nfs_sync_mapping - helper to flush all mmapped dirty data to disk
146  */
147 int nfs_sync_mapping(struct address_space *mapping)
148 {
149 	int ret = 0;
150 
151 	if (mapping->nrpages != 0) {
152 		unmap_mapping_range(mapping, 0, 0, 0);
153 		ret = nfs_wb_all(mapping->host);
154 	}
155 	return ret;
156 }
157 
158 static int nfs_attribute_timeout(struct inode *inode)
159 {
160 	struct nfs_inode *nfsi = NFS_I(inode);
161 
162 	return !time_in_range_open(jiffies, nfsi->read_cache_jiffies, nfsi->read_cache_jiffies + nfsi->attrtimeo);
163 }
164 
165 static bool nfs_check_cache_invalid_delegated(struct inode *inode, unsigned long flags)
166 {
167 	unsigned long cache_validity = READ_ONCE(NFS_I(inode)->cache_validity);
168 
169 	/* Special case for the pagecache or access cache */
170 	if (flags == NFS_INO_REVAL_PAGECACHE &&
171 	    !(cache_validity & NFS_INO_REVAL_FORCED))
172 		return false;
173 	return (cache_validity & flags) != 0;
174 }
175 
176 static bool nfs_check_cache_invalid_not_delegated(struct inode *inode, unsigned long flags)
177 {
178 	unsigned long cache_validity = READ_ONCE(NFS_I(inode)->cache_validity);
179 
180 	if ((cache_validity & flags) != 0)
181 		return true;
182 	if (nfs_attribute_timeout(inode))
183 		return true;
184 	return false;
185 }
186 
187 bool nfs_check_cache_invalid(struct inode *inode, unsigned long flags)
188 {
189 	if (NFS_PROTO(inode)->have_delegation(inode, FMODE_READ))
190 		return nfs_check_cache_invalid_delegated(inode, flags);
191 
192 	return nfs_check_cache_invalid_not_delegated(inode, flags);
193 }
194 
195 static void nfs_set_cache_invalid(struct inode *inode, unsigned long flags)
196 {
197 	struct nfs_inode *nfsi = NFS_I(inode);
198 	bool have_delegation = NFS_PROTO(inode)->have_delegation(inode, FMODE_READ);
199 
200 	if (have_delegation) {
201 		if (!(flags & NFS_INO_REVAL_FORCED))
202 			flags &= ~NFS_INO_INVALID_OTHER;
203 		flags &= ~(NFS_INO_INVALID_CHANGE
204 				| NFS_INO_INVALID_SIZE
205 				| NFS_INO_REVAL_PAGECACHE);
206 	}
207 
208 	if (inode->i_mapping->nrpages == 0)
209 		flags &= ~NFS_INO_INVALID_DATA;
210 	nfsi->cache_validity |= flags;
211 	if (flags & NFS_INO_INVALID_DATA)
212 		nfs_fscache_invalidate(inode);
213 }
214 
215 /*
216  * Invalidate the local caches
217  */
218 static void nfs_zap_caches_locked(struct inode *inode)
219 {
220 	struct nfs_inode *nfsi = NFS_I(inode);
221 	int mode = inode->i_mode;
222 
223 	nfs_inc_stats(inode, NFSIOS_ATTRINVALIDATE);
224 
225 	nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
226 	nfsi->attrtimeo_timestamp = jiffies;
227 
228 	memset(NFS_I(inode)->cookieverf, 0, sizeof(NFS_I(inode)->cookieverf));
229 	if (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)) {
230 		nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR
231 					| NFS_INO_INVALID_DATA
232 					| NFS_INO_INVALID_ACCESS
233 					| NFS_INO_INVALID_ACL
234 					| NFS_INO_REVAL_PAGECACHE);
235 	} else
236 		nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR
237 					| NFS_INO_INVALID_ACCESS
238 					| NFS_INO_INVALID_ACL
239 					| NFS_INO_REVAL_PAGECACHE);
240 	nfs_zap_label_cache_locked(nfsi);
241 }
242 
243 void nfs_zap_caches(struct inode *inode)
244 {
245 	spin_lock(&inode->i_lock);
246 	nfs_zap_caches_locked(inode);
247 	spin_unlock(&inode->i_lock);
248 }
249 
250 void nfs_zap_mapping(struct inode *inode, struct address_space *mapping)
251 {
252 	if (mapping->nrpages != 0) {
253 		spin_lock(&inode->i_lock);
254 		nfs_set_cache_invalid(inode, NFS_INO_INVALID_DATA);
255 		spin_unlock(&inode->i_lock);
256 	}
257 }
258 
259 void nfs_zap_acl_cache(struct inode *inode)
260 {
261 	void (*clear_acl_cache)(struct inode *);
262 
263 	clear_acl_cache = NFS_PROTO(inode)->clear_acl_cache;
264 	if (clear_acl_cache != NULL)
265 		clear_acl_cache(inode);
266 	spin_lock(&inode->i_lock);
267 	NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_ACL;
268 	spin_unlock(&inode->i_lock);
269 }
270 EXPORT_SYMBOL_GPL(nfs_zap_acl_cache);
271 
272 void nfs_invalidate_atime(struct inode *inode)
273 {
274 	spin_lock(&inode->i_lock);
275 	nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATIME);
276 	spin_unlock(&inode->i_lock);
277 }
278 EXPORT_SYMBOL_GPL(nfs_invalidate_atime);
279 
280 /*
281  * Invalidate, but do not unhash, the inode.
282  * NB: must be called with inode->i_lock held!
283  */
284 static void nfs_invalidate_inode(struct inode *inode)
285 {
286 	set_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
287 	nfs_zap_caches_locked(inode);
288 }
289 
290 struct nfs_find_desc {
291 	struct nfs_fh		*fh;
292 	struct nfs_fattr	*fattr;
293 };
294 
295 /*
296  * In NFSv3 we can have 64bit inode numbers. In order to support
297  * this, and re-exported directories (also seen in NFSv2)
298  * we are forced to allow 2 different inodes to have the same
299  * i_ino.
300  */
301 static int
302 nfs_find_actor(struct inode *inode, void *opaque)
303 {
304 	struct nfs_find_desc	*desc = (struct nfs_find_desc *)opaque;
305 	struct nfs_fh		*fh = desc->fh;
306 	struct nfs_fattr	*fattr = desc->fattr;
307 
308 	if (NFS_FILEID(inode) != fattr->fileid)
309 		return 0;
310 	if ((S_IFMT & inode->i_mode) != (S_IFMT & fattr->mode))
311 		return 0;
312 	if (nfs_compare_fh(NFS_FH(inode), fh))
313 		return 0;
314 	if (is_bad_inode(inode) || NFS_STALE(inode))
315 		return 0;
316 	return 1;
317 }
318 
319 static int
320 nfs_init_locked(struct inode *inode, void *opaque)
321 {
322 	struct nfs_find_desc	*desc = (struct nfs_find_desc *)opaque;
323 	struct nfs_fattr	*fattr = desc->fattr;
324 
325 	set_nfs_fileid(inode, fattr->fileid);
326 	inode->i_mode = fattr->mode;
327 	nfs_copy_fh(NFS_FH(inode), desc->fh);
328 	return 0;
329 }
330 
331 #ifdef CONFIG_NFS_V4_SECURITY_LABEL
332 static void nfs_clear_label_invalid(struct inode *inode)
333 {
334 	spin_lock(&inode->i_lock);
335 	NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_LABEL;
336 	spin_unlock(&inode->i_lock);
337 }
338 
339 void nfs_setsecurity(struct inode *inode, struct nfs_fattr *fattr,
340 					struct nfs4_label *label)
341 {
342 	int error;
343 
344 	if (label == NULL)
345 		return;
346 
347 	if ((fattr->valid & NFS_ATTR_FATTR_V4_SECURITY_LABEL) && inode->i_security) {
348 		error = security_inode_notifysecctx(inode, label->label,
349 				label->len);
350 		if (error)
351 			printk(KERN_ERR "%s() %s %d "
352 					"security_inode_notifysecctx() %d\n",
353 					__func__,
354 					(char *)label->label,
355 					label->len, error);
356 		nfs_clear_label_invalid(inode);
357 	}
358 }
359 
360 struct nfs4_label *nfs4_label_alloc(struct nfs_server *server, gfp_t flags)
361 {
362 	struct nfs4_label *label = NULL;
363 	int minor_version = server->nfs_client->cl_minorversion;
364 
365 	if (minor_version < 2)
366 		return label;
367 
368 	if (!(server->caps & NFS_CAP_SECURITY_LABEL))
369 		return label;
370 
371 	label = kzalloc(sizeof(struct nfs4_label), flags);
372 	if (label == NULL)
373 		return ERR_PTR(-ENOMEM);
374 
375 	label->label = kzalloc(NFS4_MAXLABELLEN, flags);
376 	if (label->label == NULL) {
377 		kfree(label);
378 		return ERR_PTR(-ENOMEM);
379 	}
380 	label->len = NFS4_MAXLABELLEN;
381 
382 	return label;
383 }
384 EXPORT_SYMBOL_GPL(nfs4_label_alloc);
385 #else
386 void nfs_setsecurity(struct inode *inode, struct nfs_fattr *fattr,
387 					struct nfs4_label *label)
388 {
389 }
390 #endif
391 EXPORT_SYMBOL_GPL(nfs_setsecurity);
392 
393 /* Search for inode identified by fh, fileid and i_mode in inode cache. */
394 struct inode *
395 nfs_ilookup(struct super_block *sb, struct nfs_fattr *fattr, struct nfs_fh *fh)
396 {
397 	struct nfs_find_desc desc = {
398 		.fh	= fh,
399 		.fattr	= fattr,
400 	};
401 	struct inode *inode;
402 	unsigned long hash;
403 
404 	if (!(fattr->valid & NFS_ATTR_FATTR_FILEID) ||
405 	    !(fattr->valid & NFS_ATTR_FATTR_TYPE))
406 		return NULL;
407 
408 	hash = nfs_fattr_to_ino_t(fattr);
409 	inode = ilookup5(sb, hash, nfs_find_actor, &desc);
410 
411 	dprintk("%s: returning %p\n", __func__, inode);
412 	return inode;
413 }
414 
415 /*
416  * This is our front-end to iget that looks up inodes by file handle
417  * instead of inode number.
418  */
419 struct inode *
420 nfs_fhget(struct super_block *sb, struct nfs_fh *fh, struct nfs_fattr *fattr, struct nfs4_label *label)
421 {
422 	struct nfs_find_desc desc = {
423 		.fh	= fh,
424 		.fattr	= fattr
425 	};
426 	struct inode *inode = ERR_PTR(-ENOENT);
427 	unsigned long hash;
428 
429 	nfs_attr_check_mountpoint(sb, fattr);
430 
431 	if (nfs_attr_use_mounted_on_fileid(fattr))
432 		fattr->fileid = fattr->mounted_on_fileid;
433 	else if ((fattr->valid & NFS_ATTR_FATTR_FILEID) == 0)
434 		goto out_no_inode;
435 	if ((fattr->valid & NFS_ATTR_FATTR_TYPE) == 0)
436 		goto out_no_inode;
437 
438 	hash = nfs_fattr_to_ino_t(fattr);
439 
440 	inode = iget5_locked(sb, hash, nfs_find_actor, nfs_init_locked, &desc);
441 	if (inode == NULL) {
442 		inode = ERR_PTR(-ENOMEM);
443 		goto out_no_inode;
444 	}
445 
446 	if (inode->i_state & I_NEW) {
447 		struct nfs_inode *nfsi = NFS_I(inode);
448 		unsigned long now = jiffies;
449 
450 		/* We set i_ino for the few things that still rely on it,
451 		 * such as stat(2) */
452 		inode->i_ino = hash;
453 
454 		/* We can't support update_atime(), since the server will reset it */
455 		inode->i_flags |= S_NOATIME|S_NOCMTIME;
456 		inode->i_mode = fattr->mode;
457 		nfsi->cache_validity = 0;
458 		if ((fattr->valid & NFS_ATTR_FATTR_MODE) == 0
459 				&& nfs_server_capable(inode, NFS_CAP_MODE))
460 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_OTHER);
461 		/* Why so? Because we want revalidate for devices/FIFOs, and
462 		 * that's precisely what we have in nfs_file_inode_operations.
463 		 */
464 		inode->i_op = NFS_SB(sb)->nfs_client->rpc_ops->file_inode_ops;
465 		if (S_ISREG(inode->i_mode)) {
466 			inode->i_fop = NFS_SB(sb)->nfs_client->rpc_ops->file_ops;
467 			inode->i_data.a_ops = &nfs_file_aops;
468 		} else if (S_ISDIR(inode->i_mode)) {
469 			inode->i_op = NFS_SB(sb)->nfs_client->rpc_ops->dir_inode_ops;
470 			inode->i_fop = &nfs_dir_operations;
471 			inode->i_data.a_ops = &nfs_dir_aops;
472 			/* Deal with crossing mountpoints */
473 			if (fattr->valid & NFS_ATTR_FATTR_MOUNTPOINT ||
474 					fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL) {
475 				if (fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL)
476 					inode->i_op = &nfs_referral_inode_operations;
477 				else
478 					inode->i_op = &nfs_mountpoint_inode_operations;
479 				inode->i_fop = NULL;
480 				inode->i_flags |= S_AUTOMOUNT;
481 			}
482 		} else if (S_ISLNK(inode->i_mode)) {
483 			inode->i_op = &nfs_symlink_inode_operations;
484 			inode_nohighmem(inode);
485 		} else
486 			init_special_inode(inode, inode->i_mode, fattr->rdev);
487 
488 		memset(&inode->i_atime, 0, sizeof(inode->i_atime));
489 		memset(&inode->i_mtime, 0, sizeof(inode->i_mtime));
490 		memset(&inode->i_ctime, 0, sizeof(inode->i_ctime));
491 		inode_set_iversion_raw(inode, 0);
492 		inode->i_size = 0;
493 		clear_nlink(inode);
494 		inode->i_uid = make_kuid(&init_user_ns, -2);
495 		inode->i_gid = make_kgid(&init_user_ns, -2);
496 		inode->i_blocks = 0;
497 		memset(nfsi->cookieverf, 0, sizeof(nfsi->cookieverf));
498 		nfsi->write_io = 0;
499 		nfsi->read_io = 0;
500 
501 		nfsi->read_cache_jiffies = fattr->time_start;
502 		nfsi->attr_gencount = fattr->gencount;
503 		if (fattr->valid & NFS_ATTR_FATTR_ATIME)
504 			inode->i_atime = fattr->atime;
505 		else if (nfs_server_capable(inode, NFS_CAP_ATIME))
506 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATIME);
507 		if (fattr->valid & NFS_ATTR_FATTR_MTIME)
508 			inode->i_mtime = fattr->mtime;
509 		else if (nfs_server_capable(inode, NFS_CAP_MTIME))
510 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_MTIME);
511 		if (fattr->valid & NFS_ATTR_FATTR_CTIME)
512 			inode->i_ctime = fattr->ctime;
513 		else if (nfs_server_capable(inode, NFS_CAP_CTIME))
514 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_CTIME);
515 		if (fattr->valid & NFS_ATTR_FATTR_CHANGE)
516 			inode_set_iversion_raw(inode, fattr->change_attr);
517 		else
518 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_CHANGE);
519 		if (fattr->valid & NFS_ATTR_FATTR_SIZE)
520 			inode->i_size = nfs_size_to_loff_t(fattr->size);
521 		else
522 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_SIZE);
523 		if (fattr->valid & NFS_ATTR_FATTR_NLINK)
524 			set_nlink(inode, fattr->nlink);
525 		else if (nfs_server_capable(inode, NFS_CAP_NLINK))
526 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_OTHER);
527 		if (fattr->valid & NFS_ATTR_FATTR_OWNER)
528 			inode->i_uid = fattr->uid;
529 		else if (nfs_server_capable(inode, NFS_CAP_OWNER))
530 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_OTHER);
531 		if (fattr->valid & NFS_ATTR_FATTR_GROUP)
532 			inode->i_gid = fattr->gid;
533 		else if (nfs_server_capable(inode, NFS_CAP_OWNER_GROUP))
534 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_OTHER);
535 		if (fattr->valid & NFS_ATTR_FATTR_BLOCKS_USED)
536 			inode->i_blocks = fattr->du.nfs2.blocks;
537 		if (fattr->valid & NFS_ATTR_FATTR_SPACE_USED) {
538 			/*
539 			 * report the blocks in 512byte units
540 			 */
541 			inode->i_blocks = nfs_calc_block_size(fattr->du.nfs3.used);
542 		}
543 
544 		if (nfsi->cache_validity != 0)
545 			nfsi->cache_validity |= NFS_INO_REVAL_FORCED;
546 
547 		nfs_setsecurity(inode, fattr, label);
548 
549 		nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
550 		nfsi->attrtimeo_timestamp = now;
551 		nfsi->access_cache = RB_ROOT;
552 
553 		nfs_fscache_init_inode(inode);
554 
555 		unlock_new_inode(inode);
556 	} else {
557 		int err = nfs_refresh_inode(inode, fattr);
558 		if (err < 0) {
559 			iput(inode);
560 			inode = ERR_PTR(err);
561 			goto out_no_inode;
562 		}
563 	}
564 	dprintk("NFS: nfs_fhget(%s/%Lu fh_crc=0x%08x ct=%d)\n",
565 		inode->i_sb->s_id,
566 		(unsigned long long)NFS_FILEID(inode),
567 		nfs_display_fhandle_hash(fh),
568 		atomic_read(&inode->i_count));
569 
570 out:
571 	return inode;
572 
573 out_no_inode:
574 	dprintk("nfs_fhget: iget failed with error %ld\n", PTR_ERR(inode));
575 	goto out;
576 }
577 EXPORT_SYMBOL_GPL(nfs_fhget);
578 
579 #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)
580 
581 int
582 nfs_setattr(struct dentry *dentry, struct iattr *attr)
583 {
584 	struct inode *inode = d_inode(dentry);
585 	struct nfs_fattr *fattr;
586 	int error = 0;
587 
588 	nfs_inc_stats(inode, NFSIOS_VFSSETATTR);
589 
590 	/* skip mode change if it's just for clearing setuid/setgid */
591 	if (attr->ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
592 		attr->ia_valid &= ~ATTR_MODE;
593 
594 	if (attr->ia_valid & ATTR_SIZE) {
595 		BUG_ON(!S_ISREG(inode->i_mode));
596 
597 		error = inode_newsize_ok(inode, attr->ia_size);
598 		if (error)
599 			return error;
600 
601 		if (attr->ia_size == i_size_read(inode))
602 			attr->ia_valid &= ~ATTR_SIZE;
603 	}
604 
605 	/* Optimization: if the end result is no change, don't RPC */
606 	attr->ia_valid &= NFS_VALID_ATTRS;
607 	if ((attr->ia_valid & ~(ATTR_FILE|ATTR_OPEN)) == 0)
608 		return 0;
609 
610 	trace_nfs_setattr_enter(inode);
611 
612 	/* Write all dirty data */
613 	if (S_ISREG(inode->i_mode))
614 		nfs_sync_inode(inode);
615 
616 	fattr = nfs_alloc_fattr();
617 	if (fattr == NULL) {
618 		error = -ENOMEM;
619 		goto out;
620 	}
621 
622 	error = NFS_PROTO(inode)->setattr(dentry, fattr, attr);
623 	if (error == 0)
624 		error = nfs_refresh_inode(inode, fattr);
625 	nfs_free_fattr(fattr);
626 out:
627 	trace_nfs_setattr_exit(inode, error);
628 	return error;
629 }
630 EXPORT_SYMBOL_GPL(nfs_setattr);
631 
632 /**
633  * nfs_vmtruncate - unmap mappings "freed" by truncate() syscall
634  * @inode: inode of the file used
635  * @offset: file offset to start truncating
636  *
637  * This is a copy of the common vmtruncate, but with the locking
638  * corrected to take into account the fact that NFS requires
639  * inode->i_size to be updated under the inode->i_lock.
640  * Note: must be called with inode->i_lock held!
641  */
642 static int nfs_vmtruncate(struct inode * inode, loff_t offset)
643 {
644 	int err;
645 
646 	err = inode_newsize_ok(inode, offset);
647 	if (err)
648 		goto out;
649 
650 	i_size_write(inode, offset);
651 	/* Optimisation */
652 	if (offset == 0)
653 		NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_DATA;
654 	NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_SIZE;
655 
656 	spin_unlock(&inode->i_lock);
657 	truncate_pagecache(inode, offset);
658 	spin_lock(&inode->i_lock);
659 out:
660 	return err;
661 }
662 
663 /**
664  * nfs_setattr_update_inode - Update inode metadata after a setattr call.
665  * @inode: pointer to struct inode
666  * @attr: pointer to struct iattr
667  * @fattr: pointer to struct nfs_fattr
668  *
669  * Note: we do this in the *proc.c in order to ensure that
670  *       it works for things like exclusive creates too.
671  */
672 void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr,
673 		struct nfs_fattr *fattr)
674 {
675 	/* Barrier: bump the attribute generation count. */
676 	nfs_fattr_set_barrier(fattr);
677 
678 	spin_lock(&inode->i_lock);
679 	NFS_I(inode)->attr_gencount = fattr->gencount;
680 	if ((attr->ia_valid & ATTR_SIZE) != 0) {
681 		nfs_set_cache_invalid(inode, NFS_INO_INVALID_MTIME);
682 		nfs_inc_stats(inode, NFSIOS_SETATTRTRUNC);
683 		nfs_vmtruncate(inode, attr->ia_size);
684 	}
685 	if ((attr->ia_valid & (ATTR_MODE|ATTR_UID|ATTR_GID)) != 0) {
686 		NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_CTIME;
687 		if ((attr->ia_valid & ATTR_MODE) != 0) {
688 			int mode = attr->ia_mode & S_IALLUGO;
689 			mode |= inode->i_mode & ~S_IALLUGO;
690 			inode->i_mode = mode;
691 		}
692 		if ((attr->ia_valid & ATTR_UID) != 0)
693 			inode->i_uid = attr->ia_uid;
694 		if ((attr->ia_valid & ATTR_GID) != 0)
695 			inode->i_gid = attr->ia_gid;
696 		if (fattr->valid & NFS_ATTR_FATTR_CTIME)
697 			inode->i_ctime = fattr->ctime;
698 		else
699 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_CHANGE
700 					| NFS_INO_INVALID_CTIME);
701 		nfs_set_cache_invalid(inode, NFS_INO_INVALID_ACCESS
702 				| NFS_INO_INVALID_ACL);
703 	}
704 	if (attr->ia_valid & (ATTR_ATIME_SET|ATTR_ATIME)) {
705 		NFS_I(inode)->cache_validity &= ~(NFS_INO_INVALID_ATIME
706 				| NFS_INO_INVALID_CTIME);
707 		if (fattr->valid & NFS_ATTR_FATTR_ATIME)
708 			inode->i_atime = fattr->atime;
709 		else if (attr->ia_valid & ATTR_ATIME_SET)
710 			inode->i_atime = attr->ia_atime;
711 		else
712 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATIME);
713 
714 		if (fattr->valid & NFS_ATTR_FATTR_CTIME)
715 			inode->i_ctime = fattr->ctime;
716 		else
717 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_CHANGE
718 					| NFS_INO_INVALID_CTIME);
719 	}
720 	if (attr->ia_valid & (ATTR_MTIME_SET|ATTR_MTIME)) {
721 		NFS_I(inode)->cache_validity &= ~(NFS_INO_INVALID_MTIME
722 				| NFS_INO_INVALID_CTIME);
723 		if (fattr->valid & NFS_ATTR_FATTR_MTIME)
724 			inode->i_mtime = fattr->mtime;
725 		else if (attr->ia_valid & ATTR_MTIME_SET)
726 			inode->i_mtime = attr->ia_mtime;
727 		else
728 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_MTIME);
729 
730 		if (fattr->valid & NFS_ATTR_FATTR_CTIME)
731 			inode->i_ctime = fattr->ctime;
732 		else
733 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_CHANGE
734 					| NFS_INO_INVALID_CTIME);
735 	}
736 	if (fattr->valid)
737 		nfs_update_inode(inode, fattr);
738 	spin_unlock(&inode->i_lock);
739 }
740 EXPORT_SYMBOL_GPL(nfs_setattr_update_inode);
741 
742 static void nfs_readdirplus_parent_cache_miss(struct dentry *dentry)
743 {
744 	struct dentry *parent;
745 
746 	if (!nfs_server_capable(d_inode(dentry), NFS_CAP_READDIRPLUS))
747 		return;
748 	parent = dget_parent(dentry);
749 	nfs_force_use_readdirplus(d_inode(parent));
750 	dput(parent);
751 }
752 
753 static void nfs_readdirplus_parent_cache_hit(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_advise_use_readdirplus(d_inode(parent));
761 	dput(parent);
762 }
763 
764 static bool nfs_need_revalidate_inode(struct inode *inode)
765 {
766 	if (NFS_I(inode)->cache_validity &
767 			(NFS_INO_INVALID_ATTR|NFS_INO_INVALID_LABEL))
768 		return true;
769 	if (nfs_attribute_cache_expired(inode))
770 		return true;
771 	return false;
772 }
773 
774 int nfs_getattr(const struct path *path, struct kstat *stat,
775 		u32 request_mask, unsigned int query_flags)
776 {
777 	struct inode *inode = d_inode(path->dentry);
778 	struct nfs_server *server = NFS_SERVER(inode);
779 	unsigned long cache_validity;
780 	int err = 0;
781 	bool force_sync = query_flags & AT_STATX_FORCE_SYNC;
782 	bool do_update = false;
783 
784 	trace_nfs_getattr_enter(inode);
785 
786 	if ((query_flags & AT_STATX_DONT_SYNC) && !force_sync)
787 		goto out_no_update;
788 
789 	/* Flush out writes to the server in order to update c/mtime.  */
790 	if ((request_mask & (STATX_CTIME|STATX_MTIME)) &&
791 			S_ISREG(inode->i_mode)) {
792 		err = filemap_write_and_wait(inode->i_mapping);
793 		if (err)
794 			goto out;
795 	}
796 
797 	/*
798 	 * We may force a getattr if the user cares about atime.
799 	 *
800 	 * Note that we only have to check the vfsmount flags here:
801 	 *  - NFS always sets S_NOATIME by so checking it would give a
802 	 *    bogus result
803 	 *  - NFS never sets SB_NOATIME or SB_NODIRATIME so there is
804 	 *    no point in checking those.
805 	 */
806 	if ((path->mnt->mnt_flags & MNT_NOATIME) ||
807 	    ((path->mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode)))
808 		request_mask &= ~STATX_ATIME;
809 
810 	/* Is the user requesting attributes that might need revalidation? */
811 	if (!(request_mask & (STATX_MODE|STATX_NLINK|STATX_ATIME|STATX_CTIME|
812 					STATX_MTIME|STATX_UID|STATX_GID|
813 					STATX_SIZE|STATX_BLOCKS)))
814 		goto out_no_revalidate;
815 
816 	/* Check whether the cached attributes are stale */
817 	do_update |= force_sync || nfs_attribute_cache_expired(inode);
818 	cache_validity = READ_ONCE(NFS_I(inode)->cache_validity);
819 	do_update |= cache_validity &
820 		(NFS_INO_INVALID_ATTR|NFS_INO_INVALID_LABEL);
821 	if (request_mask & STATX_ATIME)
822 		do_update |= cache_validity & NFS_INO_INVALID_ATIME;
823 	if (request_mask & (STATX_CTIME|STATX_MTIME))
824 		do_update |= cache_validity & NFS_INO_REVAL_PAGECACHE;
825 	if (do_update) {
826 		/* Update the attribute cache */
827 		if (!(server->flags & NFS_MOUNT_NOAC))
828 			nfs_readdirplus_parent_cache_miss(path->dentry);
829 		else
830 			nfs_readdirplus_parent_cache_hit(path->dentry);
831 		err = __nfs_revalidate_inode(server, inode);
832 		if (err)
833 			goto out;
834 	} else
835 		nfs_readdirplus_parent_cache_hit(path->dentry);
836 out_no_revalidate:
837 	/* Only return attributes that were revalidated. */
838 	stat->result_mask &= request_mask;
839 out_no_update:
840 	generic_fillattr(inode, stat);
841 	stat->ino = nfs_compat_user_ino64(NFS_FILEID(inode));
842 	if (S_ISDIR(inode->i_mode))
843 		stat->blksize = NFS_SERVER(inode)->dtsize;
844 out:
845 	trace_nfs_getattr_exit(inode, err);
846 	return err;
847 }
848 EXPORT_SYMBOL_GPL(nfs_getattr);
849 
850 static void nfs_init_lock_context(struct nfs_lock_context *l_ctx)
851 {
852 	refcount_set(&l_ctx->count, 1);
853 	l_ctx->lockowner = current->files;
854 	INIT_LIST_HEAD(&l_ctx->list);
855 	atomic_set(&l_ctx->io_count, 0);
856 }
857 
858 static struct nfs_lock_context *__nfs_find_lock_context(struct nfs_open_context *ctx)
859 {
860 	struct nfs_lock_context *head = &ctx->lock_context;
861 	struct nfs_lock_context *pos = head;
862 
863 	do {
864 		if (pos->lockowner != current->files)
865 			continue;
866 		refcount_inc(&pos->count);
867 		return pos;
868 	} while ((pos = list_entry(pos->list.next, typeof(*pos), list)) != head);
869 	return NULL;
870 }
871 
872 struct nfs_lock_context *nfs_get_lock_context(struct nfs_open_context *ctx)
873 {
874 	struct nfs_lock_context *res, *new = NULL;
875 	struct inode *inode = d_inode(ctx->dentry);
876 
877 	spin_lock(&inode->i_lock);
878 	res = __nfs_find_lock_context(ctx);
879 	if (res == NULL) {
880 		spin_unlock(&inode->i_lock);
881 		new = kmalloc(sizeof(*new), GFP_KERNEL);
882 		if (new == NULL)
883 			return ERR_PTR(-ENOMEM);
884 		nfs_init_lock_context(new);
885 		spin_lock(&inode->i_lock);
886 		res = __nfs_find_lock_context(ctx);
887 		if (res == NULL) {
888 			list_add_tail(&new->list, &ctx->lock_context.list);
889 			new->open_context = ctx;
890 			res = new;
891 			new = NULL;
892 		}
893 	}
894 	spin_unlock(&inode->i_lock);
895 	kfree(new);
896 	return res;
897 }
898 EXPORT_SYMBOL_GPL(nfs_get_lock_context);
899 
900 void nfs_put_lock_context(struct nfs_lock_context *l_ctx)
901 {
902 	struct nfs_open_context *ctx = l_ctx->open_context;
903 	struct inode *inode = d_inode(ctx->dentry);
904 
905 	if (!refcount_dec_and_lock(&l_ctx->count, &inode->i_lock))
906 		return;
907 	list_del(&l_ctx->list);
908 	spin_unlock(&inode->i_lock);
909 	kfree(l_ctx);
910 }
911 EXPORT_SYMBOL_GPL(nfs_put_lock_context);
912 
913 /**
914  * nfs_close_context - Common close_context() routine NFSv2/v3
915  * @ctx: pointer to context
916  * @is_sync: is this a synchronous close
917  *
918  * Ensure that the attributes are up to date if we're mounted
919  * with close-to-open semantics and we have cached data that will
920  * need to be revalidated on open.
921  */
922 void nfs_close_context(struct nfs_open_context *ctx, int is_sync)
923 {
924 	struct nfs_inode *nfsi;
925 	struct inode *inode;
926 	struct nfs_server *server;
927 
928 	if (!(ctx->mode & FMODE_WRITE))
929 		return;
930 	if (!is_sync)
931 		return;
932 	inode = d_inode(ctx->dentry);
933 	if (NFS_PROTO(inode)->have_delegation(inode, FMODE_READ))
934 		return;
935 	nfsi = NFS_I(inode);
936 	if (inode->i_mapping->nrpages == 0)
937 		return;
938 	if (nfsi->cache_validity & NFS_INO_INVALID_DATA)
939 		return;
940 	if (!list_empty(&nfsi->open_files))
941 		return;
942 	server = NFS_SERVER(inode);
943 	if (server->flags & NFS_MOUNT_NOCTO)
944 		return;
945 	nfs_revalidate_inode(server, inode);
946 }
947 EXPORT_SYMBOL_GPL(nfs_close_context);
948 
949 struct nfs_open_context *alloc_nfs_open_context(struct dentry *dentry,
950 						fmode_t f_mode,
951 						struct file *filp)
952 {
953 	struct nfs_open_context *ctx;
954 	struct rpc_cred *cred = rpc_lookup_cred();
955 	if (IS_ERR(cred))
956 		return ERR_CAST(cred);
957 
958 	ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
959 	if (!ctx) {
960 		put_rpccred(cred);
961 		return ERR_PTR(-ENOMEM);
962 	}
963 	nfs_sb_active(dentry->d_sb);
964 	ctx->dentry = dget(dentry);
965 	ctx->cred = cred;
966 	ctx->state = NULL;
967 	ctx->mode = f_mode;
968 	ctx->flags = 0;
969 	ctx->error = 0;
970 	ctx->flock_owner = (fl_owner_t)filp;
971 	nfs_init_lock_context(&ctx->lock_context);
972 	ctx->lock_context.open_context = ctx;
973 	INIT_LIST_HEAD(&ctx->list);
974 	ctx->mdsthreshold = NULL;
975 	return ctx;
976 }
977 EXPORT_SYMBOL_GPL(alloc_nfs_open_context);
978 
979 struct nfs_open_context *get_nfs_open_context(struct nfs_open_context *ctx)
980 {
981 	if (ctx != NULL)
982 		refcount_inc(&ctx->lock_context.count);
983 	return ctx;
984 }
985 EXPORT_SYMBOL_GPL(get_nfs_open_context);
986 
987 static void __put_nfs_open_context(struct nfs_open_context *ctx, int is_sync)
988 {
989 	struct inode *inode = d_inode(ctx->dentry);
990 	struct super_block *sb = ctx->dentry->d_sb;
991 
992 	if (!list_empty(&ctx->list)) {
993 		if (!refcount_dec_and_lock(&ctx->lock_context.count, &inode->i_lock))
994 			return;
995 		list_del(&ctx->list);
996 		spin_unlock(&inode->i_lock);
997 	} else if (!refcount_dec_and_test(&ctx->lock_context.count))
998 		return;
999 	if (inode != NULL)
1000 		NFS_PROTO(inode)->close_context(ctx, is_sync);
1001 	if (ctx->cred != NULL)
1002 		put_rpccred(ctx->cred);
1003 	dput(ctx->dentry);
1004 	nfs_sb_deactive(sb);
1005 	kfree(ctx->mdsthreshold);
1006 	kfree(ctx);
1007 }
1008 
1009 void put_nfs_open_context(struct nfs_open_context *ctx)
1010 {
1011 	__put_nfs_open_context(ctx, 0);
1012 }
1013 EXPORT_SYMBOL_GPL(put_nfs_open_context);
1014 
1015 static void put_nfs_open_context_sync(struct nfs_open_context *ctx)
1016 {
1017 	__put_nfs_open_context(ctx, 1);
1018 }
1019 
1020 /*
1021  * Ensure that mmap has a recent RPC credential for use when writing out
1022  * shared pages
1023  */
1024 void nfs_inode_attach_open_context(struct nfs_open_context *ctx)
1025 {
1026 	struct inode *inode = d_inode(ctx->dentry);
1027 	struct nfs_inode *nfsi = NFS_I(inode);
1028 
1029 	spin_lock(&inode->i_lock);
1030 	if (ctx->mode & FMODE_WRITE)
1031 		list_add(&ctx->list, &nfsi->open_files);
1032 	else
1033 		list_add_tail(&ctx->list, &nfsi->open_files);
1034 	spin_unlock(&inode->i_lock);
1035 }
1036 EXPORT_SYMBOL_GPL(nfs_inode_attach_open_context);
1037 
1038 void nfs_file_set_open_context(struct file *filp, struct nfs_open_context *ctx)
1039 {
1040 	filp->private_data = get_nfs_open_context(ctx);
1041 	if (list_empty(&ctx->list))
1042 		nfs_inode_attach_open_context(ctx);
1043 }
1044 EXPORT_SYMBOL_GPL(nfs_file_set_open_context);
1045 
1046 /*
1047  * Given an inode, search for an open context with the desired characteristics
1048  */
1049 struct nfs_open_context *nfs_find_open_context(struct inode *inode, struct rpc_cred *cred, fmode_t mode)
1050 {
1051 	struct nfs_inode *nfsi = NFS_I(inode);
1052 	struct nfs_open_context *pos, *ctx = NULL;
1053 
1054 	spin_lock(&inode->i_lock);
1055 	list_for_each_entry(pos, &nfsi->open_files, list) {
1056 		if (cred != NULL && pos->cred != cred)
1057 			continue;
1058 		if ((pos->mode & (FMODE_READ|FMODE_WRITE)) != mode)
1059 			continue;
1060 		ctx = get_nfs_open_context(pos);
1061 		break;
1062 	}
1063 	spin_unlock(&inode->i_lock);
1064 	return ctx;
1065 }
1066 
1067 void nfs_file_clear_open_context(struct file *filp)
1068 {
1069 	struct nfs_open_context *ctx = nfs_file_open_context(filp);
1070 
1071 	if (ctx) {
1072 		struct inode *inode = d_inode(ctx->dentry);
1073 
1074 		/*
1075 		 * We fatal error on write before. Try to writeback
1076 		 * every page again.
1077 		 */
1078 		if (ctx->error < 0)
1079 			invalidate_inode_pages2(inode->i_mapping);
1080 		filp->private_data = NULL;
1081 		spin_lock(&inode->i_lock);
1082 		list_move_tail(&ctx->list, &NFS_I(inode)->open_files);
1083 		spin_unlock(&inode->i_lock);
1084 		put_nfs_open_context_sync(ctx);
1085 	}
1086 }
1087 
1088 /*
1089  * These allocate and release file read/write context information.
1090  */
1091 int nfs_open(struct inode *inode, struct file *filp)
1092 {
1093 	struct nfs_open_context *ctx;
1094 
1095 	ctx = alloc_nfs_open_context(file_dentry(filp), filp->f_mode, filp);
1096 	if (IS_ERR(ctx))
1097 		return PTR_ERR(ctx);
1098 	nfs_file_set_open_context(filp, ctx);
1099 	put_nfs_open_context(ctx);
1100 	nfs_fscache_open_file(inode, filp);
1101 	return 0;
1102 }
1103 
1104 /*
1105  * This function is called whenever some part of NFS notices that
1106  * the cached attributes have to be refreshed.
1107  */
1108 int
1109 __nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
1110 {
1111 	int		 status = -ESTALE;
1112 	struct nfs4_label *label = NULL;
1113 	struct nfs_fattr *fattr = NULL;
1114 	struct nfs_inode *nfsi = NFS_I(inode);
1115 
1116 	dfprintk(PAGECACHE, "NFS: revalidating (%s/%Lu)\n",
1117 		inode->i_sb->s_id, (unsigned long long)NFS_FILEID(inode));
1118 
1119 	trace_nfs_revalidate_inode_enter(inode);
1120 
1121 	if (is_bad_inode(inode))
1122 		goto out;
1123 	if (NFS_STALE(inode))
1124 		goto out;
1125 
1126 	/* pNFS: Attributes aren't updated until we layoutcommit */
1127 	if (S_ISREG(inode->i_mode)) {
1128 		status = pnfs_sync_inode(inode, false);
1129 		if (status)
1130 			goto out;
1131 	}
1132 
1133 	status = -ENOMEM;
1134 	fattr = nfs_alloc_fattr();
1135 	if (fattr == NULL)
1136 		goto out;
1137 
1138 	nfs_inc_stats(inode, NFSIOS_INODEREVALIDATE);
1139 
1140 	label = nfs4_label_alloc(NFS_SERVER(inode), GFP_KERNEL);
1141 	if (IS_ERR(label)) {
1142 		status = PTR_ERR(label);
1143 		goto out;
1144 	}
1145 
1146 	status = NFS_PROTO(inode)->getattr(server, NFS_FH(inode), fattr,
1147 			label, inode);
1148 	if (status != 0) {
1149 		dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Lu) getattr failed, error=%d\n",
1150 			 inode->i_sb->s_id,
1151 			 (unsigned long long)NFS_FILEID(inode), status);
1152 		if (status == -ESTALE) {
1153 			nfs_zap_caches(inode);
1154 			if (!S_ISDIR(inode->i_mode))
1155 				set_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
1156 		}
1157 		goto err_out;
1158 	}
1159 
1160 	status = nfs_refresh_inode(inode, fattr);
1161 	if (status) {
1162 		dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Lu) refresh failed, error=%d\n",
1163 			 inode->i_sb->s_id,
1164 			 (unsigned long long)NFS_FILEID(inode), status);
1165 		goto err_out;
1166 	}
1167 
1168 	if (nfsi->cache_validity & NFS_INO_INVALID_ACL)
1169 		nfs_zap_acl_cache(inode);
1170 
1171 	nfs_setsecurity(inode, fattr, label);
1172 
1173 	dfprintk(PAGECACHE, "NFS: (%s/%Lu) revalidation complete\n",
1174 		inode->i_sb->s_id,
1175 		(unsigned long long)NFS_FILEID(inode));
1176 
1177 err_out:
1178 	nfs4_label_free(label);
1179 out:
1180 	nfs_free_fattr(fattr);
1181 	trace_nfs_revalidate_inode_exit(inode, status);
1182 	return status;
1183 }
1184 
1185 int nfs_attribute_cache_expired(struct inode *inode)
1186 {
1187 	if (nfs_have_delegated_attributes(inode))
1188 		return 0;
1189 	return nfs_attribute_timeout(inode);
1190 }
1191 
1192 /**
1193  * nfs_revalidate_inode - Revalidate the inode attributes
1194  * @server - pointer to nfs_server struct
1195  * @inode - pointer to inode struct
1196  *
1197  * Updates inode attribute information by retrieving the data from the server.
1198  */
1199 int nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
1200 {
1201 	if (!nfs_need_revalidate_inode(inode))
1202 		return NFS_STALE(inode) ? -ESTALE : 0;
1203 	return __nfs_revalidate_inode(server, inode);
1204 }
1205 EXPORT_SYMBOL_GPL(nfs_revalidate_inode);
1206 
1207 static int nfs_invalidate_mapping(struct inode *inode, struct address_space *mapping)
1208 {
1209 	struct nfs_inode *nfsi = NFS_I(inode);
1210 	int ret;
1211 
1212 	if (mapping->nrpages != 0) {
1213 		if (S_ISREG(inode->i_mode)) {
1214 			ret = nfs_sync_mapping(mapping);
1215 			if (ret < 0)
1216 				return ret;
1217 		}
1218 		ret = invalidate_inode_pages2(mapping);
1219 		if (ret < 0)
1220 			return ret;
1221 	}
1222 	if (S_ISDIR(inode->i_mode)) {
1223 		spin_lock(&inode->i_lock);
1224 		memset(nfsi->cookieverf, 0, sizeof(nfsi->cookieverf));
1225 		spin_unlock(&inode->i_lock);
1226 	}
1227 	nfs_inc_stats(inode, NFSIOS_DATAINVALIDATE);
1228 	nfs_fscache_wait_on_invalidate(inode);
1229 
1230 	dfprintk(PAGECACHE, "NFS: (%s/%Lu) data cache invalidated\n",
1231 			inode->i_sb->s_id,
1232 			(unsigned long long)NFS_FILEID(inode));
1233 	return 0;
1234 }
1235 
1236 bool nfs_mapping_need_revalidate_inode(struct inode *inode)
1237 {
1238 	return nfs_check_cache_invalid(inode, NFS_INO_REVAL_PAGECACHE) ||
1239 		NFS_STALE(inode);
1240 }
1241 
1242 int nfs_revalidate_mapping_rcu(struct inode *inode)
1243 {
1244 	struct nfs_inode *nfsi = NFS_I(inode);
1245 	unsigned long *bitlock = &nfsi->flags;
1246 	int ret = 0;
1247 
1248 	if (IS_SWAPFILE(inode))
1249 		goto out;
1250 	if (nfs_mapping_need_revalidate_inode(inode)) {
1251 		ret = -ECHILD;
1252 		goto out;
1253 	}
1254 	spin_lock(&inode->i_lock);
1255 	if (test_bit(NFS_INO_INVALIDATING, bitlock) ||
1256 	    (nfsi->cache_validity & NFS_INO_INVALID_DATA))
1257 		ret = -ECHILD;
1258 	spin_unlock(&inode->i_lock);
1259 out:
1260 	return ret;
1261 }
1262 
1263 /**
1264  * nfs_revalidate_mapping - Revalidate the pagecache
1265  * @inode - pointer to host inode
1266  * @mapping - pointer to mapping
1267  */
1268 int nfs_revalidate_mapping(struct inode *inode,
1269 		struct address_space *mapping)
1270 {
1271 	struct nfs_inode *nfsi = NFS_I(inode);
1272 	unsigned long *bitlock = &nfsi->flags;
1273 	int ret = 0;
1274 
1275 	/* swapfiles are not supposed to be shared. */
1276 	if (IS_SWAPFILE(inode))
1277 		goto out;
1278 
1279 	if (nfs_mapping_need_revalidate_inode(inode)) {
1280 		ret = __nfs_revalidate_inode(NFS_SERVER(inode), inode);
1281 		if (ret < 0)
1282 			goto out;
1283 	}
1284 
1285 	/*
1286 	 * We must clear NFS_INO_INVALID_DATA first to ensure that
1287 	 * invalidations that come in while we're shooting down the mappings
1288 	 * are respected. But, that leaves a race window where one revalidator
1289 	 * can clear the flag, and then another checks it before the mapping
1290 	 * gets invalidated. Fix that by serializing access to this part of
1291 	 * the function.
1292 	 *
1293 	 * At the same time, we need to allow other tasks to see whether we
1294 	 * might be in the middle of invalidating the pages, so we only set
1295 	 * the bit lock here if it looks like we're going to be doing that.
1296 	 */
1297 	for (;;) {
1298 		ret = wait_on_bit_action(bitlock, NFS_INO_INVALIDATING,
1299 					 nfs_wait_bit_killable, TASK_KILLABLE);
1300 		if (ret)
1301 			goto out;
1302 		spin_lock(&inode->i_lock);
1303 		if (test_bit(NFS_INO_INVALIDATING, bitlock)) {
1304 			spin_unlock(&inode->i_lock);
1305 			continue;
1306 		}
1307 		if (nfsi->cache_validity & NFS_INO_INVALID_DATA)
1308 			break;
1309 		spin_unlock(&inode->i_lock);
1310 		goto out;
1311 	}
1312 
1313 	set_bit(NFS_INO_INVALIDATING, bitlock);
1314 	smp_wmb();
1315 	nfsi->cache_validity &= ~NFS_INO_INVALID_DATA;
1316 	spin_unlock(&inode->i_lock);
1317 	trace_nfs_invalidate_mapping_enter(inode);
1318 	ret = nfs_invalidate_mapping(inode, mapping);
1319 	trace_nfs_invalidate_mapping_exit(inode, ret);
1320 
1321 	clear_bit_unlock(NFS_INO_INVALIDATING, bitlock);
1322 	smp_mb__after_atomic();
1323 	wake_up_bit(bitlock, NFS_INO_INVALIDATING);
1324 out:
1325 	return ret;
1326 }
1327 
1328 static bool nfs_file_has_writers(struct nfs_inode *nfsi)
1329 {
1330 	struct inode *inode = &nfsi->vfs_inode;
1331 
1332 	assert_spin_locked(&inode->i_lock);
1333 
1334 	if (!S_ISREG(inode->i_mode))
1335 		return false;
1336 	if (list_empty(&nfsi->open_files))
1337 		return false;
1338 	/* Note: This relies on nfsi->open_files being ordered with writers
1339 	 *       being placed at the head of the list.
1340 	 *       See nfs_inode_attach_open_context()
1341 	 */
1342 	return (list_first_entry(&nfsi->open_files,
1343 			struct nfs_open_context,
1344 			list)->mode & FMODE_WRITE) == FMODE_WRITE;
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 	if ((fattr->valid & NFS_ATTR_FATTR_PRECHANGE)
1355 			&& (fattr->valid & NFS_ATTR_FATTR_CHANGE)
1356 			&& inode_eq_iversion_raw(inode, fattr->pre_change_attr)) {
1357 		inode_set_iversion_raw(inode, fattr->change_attr);
1358 		if (S_ISDIR(inode->i_mode))
1359 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_DATA);
1360 	}
1361 	/* If we have atomic WCC data, we may update some attributes */
1362 	if ((fattr->valid & NFS_ATTR_FATTR_PRECTIME)
1363 			&& (fattr->valid & NFS_ATTR_FATTR_CTIME)
1364 			&& timespec_equal(&inode->i_ctime, &fattr->pre_ctime)) {
1365 		memcpy(&inode->i_ctime, &fattr->ctime, sizeof(inode->i_ctime));
1366 	}
1367 
1368 	if ((fattr->valid & NFS_ATTR_FATTR_PREMTIME)
1369 			&& (fattr->valid & NFS_ATTR_FATTR_MTIME)
1370 			&& timespec_equal(&inode->i_mtime, &fattr->pre_mtime)) {
1371 		memcpy(&inode->i_mtime, &fattr->mtime, sizeof(inode->i_mtime));
1372 		if (S_ISDIR(inode->i_mode))
1373 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_DATA);
1374 	}
1375 	if ((fattr->valid & NFS_ATTR_FATTR_PRESIZE)
1376 			&& (fattr->valid & NFS_ATTR_FATTR_SIZE)
1377 			&& i_size_read(inode) == nfs_size_to_loff_t(fattr->pre_size)
1378 			&& !nfs_have_writebacks(inode)) {
1379 		i_size_write(inode, nfs_size_to_loff_t(fattr->size));
1380 	}
1381 }
1382 
1383 /**
1384  * nfs_check_inode_attributes - verify consistency of the inode attribute cache
1385  * @inode - pointer to inode
1386  * @fattr - updated attributes
1387  *
1388  * Verifies the attribute cache. If we have just changed the attributes,
1389  * so that fattr carries weak cache consistency data, then it may
1390  * also update the ctime/mtime/change_attribute.
1391  */
1392 static int nfs_check_inode_attributes(struct inode *inode, struct nfs_fattr *fattr)
1393 {
1394 	struct nfs_inode *nfsi = NFS_I(inode);
1395 	loff_t cur_size, new_isize;
1396 	unsigned long invalid = 0;
1397 
1398 
1399 	if (NFS_PROTO(inode)->have_delegation(inode, FMODE_READ))
1400 		return 0;
1401 
1402 	/* Has the inode gone and changed behind our back? */
1403 	if ((fattr->valid & NFS_ATTR_FATTR_FILEID) && nfsi->fileid != fattr->fileid)
1404 		return -ESTALE;
1405 	if ((fattr->valid & NFS_ATTR_FATTR_TYPE) && (inode->i_mode & S_IFMT) != (fattr->mode & S_IFMT))
1406 		return -ESTALE;
1407 
1408 	if (!nfs_file_has_buffered_writers(nfsi)) {
1409 		/* Verify a few of the more important attributes */
1410 		if ((fattr->valid & NFS_ATTR_FATTR_CHANGE) != 0 && !inode_eq_iversion_raw(inode, fattr->change_attr))
1411 			invalid |= NFS_INO_INVALID_CHANGE
1412 				| NFS_INO_REVAL_PAGECACHE;
1413 
1414 		if ((fattr->valid & NFS_ATTR_FATTR_MTIME) && !timespec_equal(&inode->i_mtime, &fattr->mtime))
1415 			invalid |= NFS_INO_INVALID_MTIME;
1416 
1417 		if ((fattr->valid & NFS_ATTR_FATTR_CTIME) && !timespec_equal(&inode->i_ctime, &fattr->ctime))
1418 			invalid |= NFS_INO_INVALID_CTIME;
1419 
1420 		if (fattr->valid & NFS_ATTR_FATTR_SIZE) {
1421 			cur_size = i_size_read(inode);
1422 			new_isize = nfs_size_to_loff_t(fattr->size);
1423 			if (cur_size != new_isize)
1424 				invalid |= NFS_INO_INVALID_SIZE
1425 					| NFS_INO_REVAL_PAGECACHE;
1426 		}
1427 	}
1428 
1429 	/* Have any file permissions changed? */
1430 	if ((fattr->valid & NFS_ATTR_FATTR_MODE) && (inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO))
1431 		invalid |= NFS_INO_INVALID_ACCESS
1432 			| NFS_INO_INVALID_ACL
1433 			| NFS_INO_INVALID_OTHER;
1434 	if ((fattr->valid & NFS_ATTR_FATTR_OWNER) && !uid_eq(inode->i_uid, fattr->uid))
1435 		invalid |= NFS_INO_INVALID_ACCESS
1436 			| NFS_INO_INVALID_ACL
1437 			| NFS_INO_INVALID_OTHER;
1438 	if ((fattr->valid & NFS_ATTR_FATTR_GROUP) && !gid_eq(inode->i_gid, fattr->gid))
1439 		invalid |= NFS_INO_INVALID_ACCESS
1440 			| NFS_INO_INVALID_ACL
1441 			| NFS_INO_INVALID_OTHER;
1442 
1443 	/* Has the link count changed? */
1444 	if ((fattr->valid & NFS_ATTR_FATTR_NLINK) && inode->i_nlink != fattr->nlink)
1445 		invalid |= NFS_INO_INVALID_OTHER;
1446 
1447 	if ((fattr->valid & NFS_ATTR_FATTR_ATIME) && !timespec_equal(&inode->i_atime, &fattr->atime))
1448 		invalid |= NFS_INO_INVALID_ATIME;
1449 
1450 	if (invalid != 0)
1451 		nfs_set_cache_invalid(inode, invalid);
1452 
1453 	nfsi->read_cache_jiffies = fattr->time_start;
1454 	return 0;
1455 }
1456 
1457 static atomic_long_t nfs_attr_generation_counter;
1458 
1459 static unsigned long nfs_read_attr_generation_counter(void)
1460 {
1461 	return atomic_long_read(&nfs_attr_generation_counter);
1462 }
1463 
1464 unsigned long nfs_inc_attr_generation_counter(void)
1465 {
1466 	return atomic_long_inc_return(&nfs_attr_generation_counter);
1467 }
1468 EXPORT_SYMBOL_GPL(nfs_inc_attr_generation_counter);
1469 
1470 void nfs_fattr_init(struct nfs_fattr *fattr)
1471 {
1472 	fattr->valid = 0;
1473 	fattr->time_start = jiffies;
1474 	fattr->gencount = nfs_inc_attr_generation_counter();
1475 	fattr->owner_name = NULL;
1476 	fattr->group_name = NULL;
1477 }
1478 EXPORT_SYMBOL_GPL(nfs_fattr_init);
1479 
1480 /**
1481  * nfs_fattr_set_barrier
1482  * @fattr: attributes
1483  *
1484  * Used to set a barrier after an attribute was updated. This
1485  * barrier ensures that older attributes from RPC calls that may
1486  * have raced with our update cannot clobber these new values.
1487  * Note that you are still responsible for ensuring that other
1488  * operations which change the attribute on the server do not
1489  * collide.
1490  */
1491 void nfs_fattr_set_barrier(struct nfs_fattr *fattr)
1492 {
1493 	fattr->gencount = nfs_inc_attr_generation_counter();
1494 }
1495 
1496 struct nfs_fattr *nfs_alloc_fattr(void)
1497 {
1498 	struct nfs_fattr *fattr;
1499 
1500 	fattr = kmalloc(sizeof(*fattr), GFP_NOFS);
1501 	if (fattr != NULL)
1502 		nfs_fattr_init(fattr);
1503 	return fattr;
1504 }
1505 EXPORT_SYMBOL_GPL(nfs_alloc_fattr);
1506 
1507 struct nfs_fh *nfs_alloc_fhandle(void)
1508 {
1509 	struct nfs_fh *fh;
1510 
1511 	fh = kmalloc(sizeof(struct nfs_fh), GFP_NOFS);
1512 	if (fh != NULL)
1513 		fh->size = 0;
1514 	return fh;
1515 }
1516 EXPORT_SYMBOL_GPL(nfs_alloc_fhandle);
1517 
1518 #ifdef NFS_DEBUG
1519 /*
1520  * _nfs_display_fhandle_hash - calculate the crc32 hash for the filehandle
1521  *                             in the same way that wireshark does
1522  *
1523  * @fh: file handle
1524  *
1525  * For debugging only.
1526  */
1527 u32 _nfs_display_fhandle_hash(const struct nfs_fh *fh)
1528 {
1529 	/* wireshark uses 32-bit AUTODIN crc and does a bitwise
1530 	 * not on the result */
1531 	return nfs_fhandle_hash(fh);
1532 }
1533 EXPORT_SYMBOL_GPL(_nfs_display_fhandle_hash);
1534 
1535 /*
1536  * _nfs_display_fhandle - display an NFS file handle on the console
1537  *
1538  * @fh: file handle to display
1539  * @caption: display caption
1540  *
1541  * For debugging only.
1542  */
1543 void _nfs_display_fhandle(const struct nfs_fh *fh, const char *caption)
1544 {
1545 	unsigned short i;
1546 
1547 	if (fh == NULL || fh->size == 0) {
1548 		printk(KERN_DEFAULT "%s at %p is empty\n", caption, fh);
1549 		return;
1550 	}
1551 
1552 	printk(KERN_DEFAULT "%s at %p is %u bytes, crc: 0x%08x:\n",
1553 	       caption, fh, fh->size, _nfs_display_fhandle_hash(fh));
1554 	for (i = 0; i < fh->size; i += 16) {
1555 		__be32 *pos = (__be32 *)&fh->data[i];
1556 
1557 		switch ((fh->size - i - 1) >> 2) {
1558 		case 0:
1559 			printk(KERN_DEFAULT " %08x\n",
1560 				be32_to_cpup(pos));
1561 			break;
1562 		case 1:
1563 			printk(KERN_DEFAULT " %08x %08x\n",
1564 				be32_to_cpup(pos), be32_to_cpup(pos + 1));
1565 			break;
1566 		case 2:
1567 			printk(KERN_DEFAULT " %08x %08x %08x\n",
1568 				be32_to_cpup(pos), be32_to_cpup(pos + 1),
1569 				be32_to_cpup(pos + 2));
1570 			break;
1571 		default:
1572 			printk(KERN_DEFAULT " %08x %08x %08x %08x\n",
1573 				be32_to_cpup(pos), be32_to_cpup(pos + 1),
1574 				be32_to_cpup(pos + 2), be32_to_cpup(pos + 3));
1575 		}
1576 	}
1577 }
1578 EXPORT_SYMBOL_GPL(_nfs_display_fhandle);
1579 #endif
1580 
1581 /**
1582  * nfs_inode_attrs_need_update - check if the inode attributes need updating
1583  * @inode - pointer to inode
1584  * @fattr - attributes
1585  *
1586  * Attempt to divine whether or not an RPC call reply carrying stale
1587  * attributes got scheduled after another call carrying updated ones.
1588  *
1589  * To do so, the function first assumes that a more recent ctime means
1590  * that the attributes in fattr are newer, however it also attempt to
1591  * catch the case where ctime either didn't change, or went backwards
1592  * (if someone reset the clock on the server) by looking at whether
1593  * or not this RPC call was started after the inode was last updated.
1594  * Note also the check for wraparound of 'attr_gencount'
1595  *
1596  * The function returns 'true' if it thinks the attributes in 'fattr' are
1597  * more recent than the ones cached in the inode.
1598  *
1599  */
1600 static int nfs_inode_attrs_need_update(const struct inode *inode, const struct nfs_fattr *fattr)
1601 {
1602 	const struct nfs_inode *nfsi = NFS_I(inode);
1603 
1604 	return ((long)fattr->gencount - (long)nfsi->attr_gencount) > 0 ||
1605 		((long)nfsi->attr_gencount - (long)nfs_read_attr_generation_counter() > 0);
1606 }
1607 
1608 static int nfs_refresh_inode_locked(struct inode *inode, struct nfs_fattr *fattr)
1609 {
1610 	int ret;
1611 
1612 	trace_nfs_refresh_inode_enter(inode);
1613 
1614 	if (nfs_inode_attrs_need_update(inode, fattr))
1615 		ret = nfs_update_inode(inode, fattr);
1616 	else
1617 		ret = nfs_check_inode_attributes(inode, fattr);
1618 
1619 	trace_nfs_refresh_inode_exit(inode, ret);
1620 	return ret;
1621 }
1622 
1623 /**
1624  * nfs_refresh_inode - try to update the inode attribute cache
1625  * @inode - pointer to inode
1626  * @fattr - updated attributes
1627  *
1628  * Check that an RPC call that returned attributes has not overlapped with
1629  * other recent updates of the inode metadata, then decide whether it is
1630  * safe to do a full update of the inode attributes, or whether just to
1631  * call nfs_check_inode_attributes.
1632  */
1633 int nfs_refresh_inode(struct inode *inode, struct nfs_fattr *fattr)
1634 {
1635 	int status;
1636 
1637 	if ((fattr->valid & NFS_ATTR_FATTR) == 0)
1638 		return 0;
1639 	spin_lock(&inode->i_lock);
1640 	status = nfs_refresh_inode_locked(inode, fattr);
1641 	spin_unlock(&inode->i_lock);
1642 
1643 	return status;
1644 }
1645 EXPORT_SYMBOL_GPL(nfs_refresh_inode);
1646 
1647 static int nfs_post_op_update_inode_locked(struct inode *inode,
1648 		struct nfs_fattr *fattr, unsigned int invalid)
1649 {
1650 	if (S_ISDIR(inode->i_mode))
1651 		invalid |= NFS_INO_INVALID_DATA;
1652 	nfs_set_cache_invalid(inode, invalid);
1653 	if ((fattr->valid & NFS_ATTR_FATTR) == 0)
1654 		return 0;
1655 	return nfs_refresh_inode_locked(inode, fattr);
1656 }
1657 
1658 /**
1659  * nfs_post_op_update_inode - try to update the inode attribute cache
1660  * @inode - pointer to inode
1661  * @fattr - updated attributes
1662  *
1663  * After an operation that has changed the inode metadata, mark the
1664  * attribute cache as being invalid, then try to update it.
1665  *
1666  * NB: if the server didn't return any post op attributes, this
1667  * function will force the retrieval of attributes before the next
1668  * NFS request.  Thus it should be used only for operations that
1669  * are expected to change one or more attributes, to avoid
1670  * unnecessary NFS requests and trips through nfs_update_inode().
1671  */
1672 int nfs_post_op_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1673 {
1674 	int status;
1675 
1676 	spin_lock(&inode->i_lock);
1677 	nfs_fattr_set_barrier(fattr);
1678 	status = nfs_post_op_update_inode_locked(inode, fattr,
1679 			NFS_INO_INVALID_CHANGE
1680 			| NFS_INO_INVALID_CTIME
1681 			| NFS_INO_REVAL_FORCED);
1682 	spin_unlock(&inode->i_lock);
1683 
1684 	return status;
1685 }
1686 EXPORT_SYMBOL_GPL(nfs_post_op_update_inode);
1687 
1688 /**
1689  * nfs_post_op_update_inode_force_wcc_locked - update the inode attribute cache
1690  * @inode - pointer to inode
1691  * @fattr - updated attributes
1692  *
1693  * After an operation that has changed the inode metadata, mark the
1694  * attribute cache as being invalid, then try to update it. Fake up
1695  * weak cache consistency data, if none exist.
1696  *
1697  * This function is mainly designed to be used by the ->write_done() functions.
1698  */
1699 int nfs_post_op_update_inode_force_wcc_locked(struct inode *inode, struct nfs_fattr *fattr)
1700 {
1701 	int status;
1702 
1703 	/* Don't do a WCC update if these attributes are already stale */
1704 	if ((fattr->valid & NFS_ATTR_FATTR) == 0 ||
1705 			!nfs_inode_attrs_need_update(inode, fattr)) {
1706 		fattr->valid &= ~(NFS_ATTR_FATTR_PRECHANGE
1707 				| NFS_ATTR_FATTR_PRESIZE
1708 				| NFS_ATTR_FATTR_PREMTIME
1709 				| NFS_ATTR_FATTR_PRECTIME);
1710 		goto out_noforce;
1711 	}
1712 	if ((fattr->valid & NFS_ATTR_FATTR_CHANGE) != 0 &&
1713 			(fattr->valid & NFS_ATTR_FATTR_PRECHANGE) == 0) {
1714 		fattr->pre_change_attr = inode_peek_iversion_raw(inode);
1715 		fattr->valid |= NFS_ATTR_FATTR_PRECHANGE;
1716 	}
1717 	if ((fattr->valid & NFS_ATTR_FATTR_CTIME) != 0 &&
1718 			(fattr->valid & NFS_ATTR_FATTR_PRECTIME) == 0) {
1719 		memcpy(&fattr->pre_ctime, &inode->i_ctime, sizeof(fattr->pre_ctime));
1720 		fattr->valid |= NFS_ATTR_FATTR_PRECTIME;
1721 	}
1722 	if ((fattr->valid & NFS_ATTR_FATTR_MTIME) != 0 &&
1723 			(fattr->valid & NFS_ATTR_FATTR_PREMTIME) == 0) {
1724 		memcpy(&fattr->pre_mtime, &inode->i_mtime, sizeof(fattr->pre_mtime));
1725 		fattr->valid |= NFS_ATTR_FATTR_PREMTIME;
1726 	}
1727 	if ((fattr->valid & NFS_ATTR_FATTR_SIZE) != 0 &&
1728 			(fattr->valid & NFS_ATTR_FATTR_PRESIZE) == 0) {
1729 		fattr->pre_size = i_size_read(inode);
1730 		fattr->valid |= NFS_ATTR_FATTR_PRESIZE;
1731 	}
1732 out_noforce:
1733 	status = nfs_post_op_update_inode_locked(inode, fattr,
1734 			NFS_INO_INVALID_CHANGE
1735 			| NFS_INO_INVALID_CTIME
1736 			| NFS_INO_INVALID_MTIME);
1737 	return status;
1738 }
1739 
1740 /**
1741  * nfs_post_op_update_inode_force_wcc - try to update the inode attribute cache
1742  * @inode - pointer to inode
1743  * @fattr - updated attributes
1744  *
1745  * After an operation that has changed the inode metadata, mark the
1746  * attribute cache as being invalid, then try to update it. Fake up
1747  * weak cache consistency data, if none exist.
1748  *
1749  * This function is mainly designed to be used by the ->write_done() functions.
1750  */
1751 int nfs_post_op_update_inode_force_wcc(struct inode *inode, struct nfs_fattr *fattr)
1752 {
1753 	int status;
1754 
1755 	spin_lock(&inode->i_lock);
1756 	nfs_fattr_set_barrier(fattr);
1757 	status = nfs_post_op_update_inode_force_wcc_locked(inode, fattr);
1758 	spin_unlock(&inode->i_lock);
1759 	return status;
1760 }
1761 EXPORT_SYMBOL_GPL(nfs_post_op_update_inode_force_wcc);
1762 
1763 
1764 static inline bool nfs_fileid_valid(struct nfs_inode *nfsi,
1765 				    struct nfs_fattr *fattr)
1766 {
1767 	bool ret1 = true, ret2 = true;
1768 
1769 	if (fattr->valid & NFS_ATTR_FATTR_FILEID)
1770 		ret1 = (nfsi->fileid == fattr->fileid);
1771 	if (fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID)
1772 		ret2 = (nfsi->fileid == fattr->mounted_on_fileid);
1773 	return ret1 || ret2;
1774 }
1775 
1776 /*
1777  * Many nfs protocol calls return the new file attributes after
1778  * an operation.  Here we update the inode to reflect the state
1779  * of the server's inode.
1780  *
1781  * This is a bit tricky because we have to make sure all dirty pages
1782  * have been sent off to the server before calling invalidate_inode_pages.
1783  * To make sure no other process adds more write requests while we try
1784  * our best to flush them, we make them sleep during the attribute refresh.
1785  *
1786  * A very similar scenario holds for the dir cache.
1787  */
1788 static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1789 {
1790 	struct nfs_server *server;
1791 	struct nfs_inode *nfsi = NFS_I(inode);
1792 	loff_t cur_isize, new_isize;
1793 	unsigned long invalid = 0;
1794 	unsigned long now = jiffies;
1795 	unsigned long save_cache_validity;
1796 	bool have_writers = nfs_file_has_buffered_writers(nfsi);
1797 	bool cache_revalidated = true;
1798 	bool attr_changed = false;
1799 	bool have_delegation;
1800 
1801 	dfprintk(VFS, "NFS: %s(%s/%lu fh_crc=0x%08x ct=%d info=0x%x)\n",
1802 			__func__, inode->i_sb->s_id, inode->i_ino,
1803 			nfs_display_fhandle_hash(NFS_FH(inode)),
1804 			atomic_read(&inode->i_count), fattr->valid);
1805 
1806 	if (!nfs_fileid_valid(nfsi, fattr)) {
1807 		printk(KERN_ERR "NFS: server %s error: fileid changed\n"
1808 			"fsid %s: expected fileid 0x%Lx, got 0x%Lx\n",
1809 			NFS_SERVER(inode)->nfs_client->cl_hostname,
1810 			inode->i_sb->s_id, (long long)nfsi->fileid,
1811 			(long long)fattr->fileid);
1812 		goto out_err;
1813 	}
1814 
1815 	/*
1816 	 * Make sure the inode's type hasn't changed.
1817 	 */
1818 	if ((fattr->valid & NFS_ATTR_FATTR_TYPE) && (inode->i_mode & S_IFMT) != (fattr->mode & S_IFMT)) {
1819 		/*
1820 		* Big trouble! The inode has become a different object.
1821 		*/
1822 		printk(KERN_DEBUG "NFS: %s: inode %lu mode changed, %07o to %07o\n",
1823 				__func__, inode->i_ino, inode->i_mode, fattr->mode);
1824 		goto out_err;
1825 	}
1826 
1827 	server = NFS_SERVER(inode);
1828 	/* Update the fsid? */
1829 	if (S_ISDIR(inode->i_mode) && (fattr->valid & NFS_ATTR_FATTR_FSID) &&
1830 			!nfs_fsid_equal(&server->fsid, &fattr->fsid) &&
1831 			!IS_AUTOMOUNT(inode))
1832 		server->fsid = fattr->fsid;
1833 
1834 	/* Save the delegation state before clearing cache_validity */
1835 	have_delegation = nfs_have_delegated_attributes(inode);
1836 
1837 	/*
1838 	 * Update the read time so we don't revalidate too often.
1839 	 */
1840 	nfsi->read_cache_jiffies = fattr->time_start;
1841 
1842 	save_cache_validity = nfsi->cache_validity;
1843 	nfsi->cache_validity &= ~(NFS_INO_INVALID_ATTR
1844 			| NFS_INO_INVALID_ATIME
1845 			| NFS_INO_REVAL_FORCED
1846 			| NFS_INO_REVAL_PAGECACHE);
1847 
1848 	/* Do atomic weak cache consistency updates */
1849 	nfs_wcc_update_inode(inode, fattr);
1850 
1851 	if (pnfs_layoutcommit_outstanding(inode)) {
1852 		nfsi->cache_validity |= save_cache_validity & NFS_INO_INVALID_ATTR;
1853 		cache_revalidated = false;
1854 	}
1855 
1856 	/* More cache consistency checks */
1857 	if (fattr->valid & NFS_ATTR_FATTR_CHANGE) {
1858 		if (!inode_eq_iversion_raw(inode, fattr->change_attr)) {
1859 			/* Could it be a race with writeback? */
1860 			if (!(have_writers || have_delegation)) {
1861 				invalid |= NFS_INO_INVALID_DATA
1862 					| NFS_INO_INVALID_ACCESS
1863 					| NFS_INO_INVALID_ACL;
1864 				/* Force revalidate of all attributes */
1865 				save_cache_validity |= NFS_INO_INVALID_CTIME
1866 					| NFS_INO_INVALID_MTIME
1867 					| NFS_INO_INVALID_SIZE
1868 					| NFS_INO_INVALID_OTHER;
1869 				if (S_ISDIR(inode->i_mode))
1870 					nfs_force_lookup_revalidate(inode);
1871 				dprintk("NFS: change_attr change on server for file %s/%ld\n",
1872 						inode->i_sb->s_id,
1873 						inode->i_ino);
1874 			}
1875 			inode_set_iversion_raw(inode, fattr->change_attr);
1876 			attr_changed = true;
1877 		}
1878 	} else {
1879 		nfsi->cache_validity |= save_cache_validity &
1880 				(NFS_INO_INVALID_CHANGE
1881 				| NFS_INO_REVAL_PAGECACHE
1882 				| NFS_INO_REVAL_FORCED);
1883 		cache_revalidated = false;
1884 	}
1885 
1886 	if (fattr->valid & NFS_ATTR_FATTR_MTIME) {
1887 		memcpy(&inode->i_mtime, &fattr->mtime, sizeof(inode->i_mtime));
1888 	} else if (server->caps & NFS_CAP_MTIME) {
1889 		nfsi->cache_validity |= save_cache_validity &
1890 				(NFS_INO_INVALID_MTIME
1891 				| NFS_INO_REVAL_FORCED);
1892 		cache_revalidated = false;
1893 	}
1894 
1895 	if (fattr->valid & NFS_ATTR_FATTR_CTIME) {
1896 		memcpy(&inode->i_ctime, &fattr->ctime, sizeof(inode->i_ctime));
1897 	} else if (server->caps & NFS_CAP_CTIME) {
1898 		nfsi->cache_validity |= save_cache_validity &
1899 				(NFS_INO_INVALID_CTIME
1900 				| NFS_INO_REVAL_FORCED);
1901 		cache_revalidated = false;
1902 	}
1903 
1904 	/* Check if our cached file size is stale */
1905 	if (fattr->valid & NFS_ATTR_FATTR_SIZE) {
1906 		new_isize = nfs_size_to_loff_t(fattr->size);
1907 		cur_isize = i_size_read(inode);
1908 		if (new_isize != cur_isize && !have_delegation) {
1909 			/* Do we perhaps have any outstanding writes, or has
1910 			 * the file grown beyond our last write? */
1911 			if (!nfs_have_writebacks(inode) || new_isize > cur_isize) {
1912 				i_size_write(inode, new_isize);
1913 				if (!have_writers)
1914 					invalid |= NFS_INO_INVALID_DATA;
1915 				attr_changed = true;
1916 			}
1917 			dprintk("NFS: isize change on server for file %s/%ld "
1918 					"(%Ld to %Ld)\n",
1919 					inode->i_sb->s_id,
1920 					inode->i_ino,
1921 					(long long)cur_isize,
1922 					(long long)new_isize);
1923 		}
1924 	} else {
1925 		nfsi->cache_validity |= save_cache_validity &
1926 				(NFS_INO_INVALID_SIZE
1927 				| NFS_INO_REVAL_PAGECACHE
1928 				| NFS_INO_REVAL_FORCED);
1929 		cache_revalidated = false;
1930 	}
1931 
1932 
1933 	if (fattr->valid & NFS_ATTR_FATTR_ATIME)
1934 		memcpy(&inode->i_atime, &fattr->atime, sizeof(inode->i_atime));
1935 	else if (server->caps & NFS_CAP_ATIME) {
1936 		nfsi->cache_validity |= save_cache_validity &
1937 				(NFS_INO_INVALID_ATIME
1938 				| NFS_INO_REVAL_FORCED);
1939 		cache_revalidated = false;
1940 	}
1941 
1942 	if (fattr->valid & NFS_ATTR_FATTR_MODE) {
1943 		if ((inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO)) {
1944 			umode_t newmode = inode->i_mode & S_IFMT;
1945 			newmode |= fattr->mode & S_IALLUGO;
1946 			inode->i_mode = newmode;
1947 			invalid |= NFS_INO_INVALID_ACCESS
1948 				| NFS_INO_INVALID_ACL;
1949 			attr_changed = true;
1950 		}
1951 	} else if (server->caps & NFS_CAP_MODE) {
1952 		nfsi->cache_validity |= save_cache_validity &
1953 				(NFS_INO_INVALID_OTHER
1954 				| NFS_INO_REVAL_FORCED);
1955 		cache_revalidated = false;
1956 	}
1957 
1958 	if (fattr->valid & NFS_ATTR_FATTR_OWNER) {
1959 		if (!uid_eq(inode->i_uid, fattr->uid)) {
1960 			invalid |= NFS_INO_INVALID_ACCESS
1961 				| NFS_INO_INVALID_ACL;
1962 			inode->i_uid = fattr->uid;
1963 			attr_changed = true;
1964 		}
1965 	} else if (server->caps & NFS_CAP_OWNER) {
1966 		nfsi->cache_validity |= save_cache_validity &
1967 				(NFS_INO_INVALID_OTHER
1968 				| NFS_INO_REVAL_FORCED);
1969 		cache_revalidated = false;
1970 	}
1971 
1972 	if (fattr->valid & NFS_ATTR_FATTR_GROUP) {
1973 		if (!gid_eq(inode->i_gid, fattr->gid)) {
1974 			invalid |= NFS_INO_INVALID_ACCESS
1975 				| NFS_INO_INVALID_ACL;
1976 			inode->i_gid = fattr->gid;
1977 			attr_changed = true;
1978 		}
1979 	} else if (server->caps & NFS_CAP_OWNER_GROUP) {
1980 		nfsi->cache_validity |= save_cache_validity &
1981 				(NFS_INO_INVALID_OTHER
1982 				| NFS_INO_REVAL_FORCED);
1983 		cache_revalidated = false;
1984 	}
1985 
1986 	if (fattr->valid & NFS_ATTR_FATTR_NLINK) {
1987 		if (inode->i_nlink != fattr->nlink) {
1988 			if (S_ISDIR(inode->i_mode))
1989 				invalid |= NFS_INO_INVALID_DATA;
1990 			set_nlink(inode, fattr->nlink);
1991 			attr_changed = true;
1992 		}
1993 	} else if (server->caps & NFS_CAP_NLINK) {
1994 		nfsi->cache_validity |= save_cache_validity &
1995 				(NFS_INO_INVALID_OTHER
1996 				| NFS_INO_REVAL_FORCED);
1997 		cache_revalidated = false;
1998 	}
1999 
2000 	if (fattr->valid & NFS_ATTR_FATTR_SPACE_USED) {
2001 		/*
2002 		 * report the blocks in 512byte units
2003 		 */
2004 		inode->i_blocks = nfs_calc_block_size(fattr->du.nfs3.used);
2005 	} else if (fattr->valid & NFS_ATTR_FATTR_BLOCKS_USED)
2006 		inode->i_blocks = fattr->du.nfs2.blocks;
2007 	else
2008 		cache_revalidated = false;
2009 
2010 	/* Update attrtimeo value if we're out of the unstable period */
2011 	if (attr_changed) {
2012 		invalid &= ~NFS_INO_INVALID_ATTR;
2013 		nfs_inc_stats(inode, NFSIOS_ATTRINVALIDATE);
2014 		nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
2015 		nfsi->attrtimeo_timestamp = now;
2016 		/* Set barrier to be more recent than all outstanding updates */
2017 		nfsi->attr_gencount = nfs_inc_attr_generation_counter();
2018 	} else {
2019 		if (cache_revalidated) {
2020 			if (!time_in_range_open(now, nfsi->attrtimeo_timestamp,
2021 				nfsi->attrtimeo_timestamp + nfsi->attrtimeo)) {
2022 				nfsi->attrtimeo <<= 1;
2023 				if (nfsi->attrtimeo > NFS_MAXATTRTIMEO(inode))
2024 					nfsi->attrtimeo = NFS_MAXATTRTIMEO(inode);
2025 			}
2026 			nfsi->attrtimeo_timestamp = now;
2027 		}
2028 		/* Set the barrier to be more recent than this fattr */
2029 		if ((long)fattr->gencount - (long)nfsi->attr_gencount > 0)
2030 			nfsi->attr_gencount = fattr->gencount;
2031 	}
2032 
2033 	/* Don't invalidate the data if we were to blame */
2034 	if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)
2035 				|| S_ISLNK(inode->i_mode)))
2036 		invalid &= ~NFS_INO_INVALID_DATA;
2037 	nfs_set_cache_invalid(inode, invalid);
2038 
2039 	return 0;
2040  out_err:
2041 	/*
2042 	 * No need to worry about unhashing the dentry, as the
2043 	 * lookup validation will know that the inode is bad.
2044 	 * (But we fall through to invalidate the caches.)
2045 	 */
2046 	nfs_invalidate_inode(inode);
2047 	return -ESTALE;
2048 }
2049 
2050 struct inode *nfs_alloc_inode(struct super_block *sb)
2051 {
2052 	struct nfs_inode *nfsi;
2053 	nfsi = kmem_cache_alloc(nfs_inode_cachep, GFP_KERNEL);
2054 	if (!nfsi)
2055 		return NULL;
2056 	nfsi->flags = 0UL;
2057 	nfsi->cache_validity = 0UL;
2058 #if IS_ENABLED(CONFIG_NFS_V4)
2059 	nfsi->nfs4_acl = NULL;
2060 #endif /* CONFIG_NFS_V4 */
2061 	return &nfsi->vfs_inode;
2062 }
2063 EXPORT_SYMBOL_GPL(nfs_alloc_inode);
2064 
2065 static void nfs_i_callback(struct rcu_head *head)
2066 {
2067 	struct inode *inode = container_of(head, struct inode, i_rcu);
2068 	kmem_cache_free(nfs_inode_cachep, NFS_I(inode));
2069 }
2070 
2071 void nfs_destroy_inode(struct inode *inode)
2072 {
2073 	call_rcu(&inode->i_rcu, nfs_i_callback);
2074 }
2075 EXPORT_SYMBOL_GPL(nfs_destroy_inode);
2076 
2077 static inline void nfs4_init_once(struct nfs_inode *nfsi)
2078 {
2079 #if IS_ENABLED(CONFIG_NFS_V4)
2080 	INIT_LIST_HEAD(&nfsi->open_states);
2081 	nfsi->delegation = NULL;
2082 	init_rwsem(&nfsi->rwsem);
2083 	nfsi->layout = NULL;
2084 #endif
2085 }
2086 
2087 static void init_once(void *foo)
2088 {
2089 	struct nfs_inode *nfsi = (struct nfs_inode *) foo;
2090 
2091 	inode_init_once(&nfsi->vfs_inode);
2092 	INIT_LIST_HEAD(&nfsi->open_files);
2093 	INIT_LIST_HEAD(&nfsi->access_cache_entry_lru);
2094 	INIT_LIST_HEAD(&nfsi->access_cache_inode_lru);
2095 	INIT_LIST_HEAD(&nfsi->commit_info.list);
2096 	atomic_long_set(&nfsi->nrequests, 0);
2097 	atomic_long_set(&nfsi->commit_info.ncommit, 0);
2098 	atomic_set(&nfsi->commit_info.rpcs_out, 0);
2099 	init_rwsem(&nfsi->rmdir_sem);
2100 	mutex_init(&nfsi->commit_mutex);
2101 	nfs4_init_once(nfsi);
2102 }
2103 
2104 static int __init nfs_init_inodecache(void)
2105 {
2106 	nfs_inode_cachep = kmem_cache_create("nfs_inode_cache",
2107 					     sizeof(struct nfs_inode),
2108 					     0, (SLAB_RECLAIM_ACCOUNT|
2109 						SLAB_MEM_SPREAD|SLAB_ACCOUNT),
2110 					     init_once);
2111 	if (nfs_inode_cachep == NULL)
2112 		return -ENOMEM;
2113 
2114 	return 0;
2115 }
2116 
2117 static void nfs_destroy_inodecache(void)
2118 {
2119 	/*
2120 	 * Make sure all delayed rcu free inodes are flushed before we
2121 	 * destroy cache.
2122 	 */
2123 	rcu_barrier();
2124 	kmem_cache_destroy(nfs_inode_cachep);
2125 }
2126 
2127 struct workqueue_struct *nfsiod_workqueue;
2128 EXPORT_SYMBOL_GPL(nfsiod_workqueue);
2129 
2130 /*
2131  * start up the nfsiod workqueue
2132  */
2133 static int nfsiod_start(void)
2134 {
2135 	struct workqueue_struct *wq;
2136 	dprintk("RPC:       creating workqueue nfsiod\n");
2137 	wq = alloc_workqueue("nfsiod", WQ_MEM_RECLAIM, 0);
2138 	if (wq == NULL)
2139 		return -ENOMEM;
2140 	nfsiod_workqueue = wq;
2141 	return 0;
2142 }
2143 
2144 /*
2145  * Destroy the nfsiod workqueue
2146  */
2147 static void nfsiod_stop(void)
2148 {
2149 	struct workqueue_struct *wq;
2150 
2151 	wq = nfsiod_workqueue;
2152 	if (wq == NULL)
2153 		return;
2154 	nfsiod_workqueue = NULL;
2155 	destroy_workqueue(wq);
2156 }
2157 
2158 unsigned int nfs_net_id;
2159 EXPORT_SYMBOL_GPL(nfs_net_id);
2160 
2161 static int nfs_net_init(struct net *net)
2162 {
2163 	nfs_clients_init(net);
2164 	return nfs_fs_proc_net_init(net);
2165 }
2166 
2167 static void nfs_net_exit(struct net *net)
2168 {
2169 	struct nfs_net *nn = net_generic(net, nfs_net_id);
2170 
2171 	nfs_fs_proc_net_exit(net);
2172 	nfs_cleanup_cb_ident_idr(net);
2173 	WARN_ON_ONCE(!list_empty(&nn->nfs_client_list));
2174 	WARN_ON_ONCE(!list_empty(&nn->nfs_volume_list));
2175 }
2176 
2177 static struct pernet_operations nfs_net_ops = {
2178 	.init = nfs_net_init,
2179 	.exit = nfs_net_exit,
2180 	.id   = &nfs_net_id,
2181 	.size = sizeof(struct nfs_net),
2182 };
2183 
2184 /*
2185  * Initialize NFS
2186  */
2187 static int __init init_nfs_fs(void)
2188 {
2189 	int err;
2190 
2191 	err = register_pernet_subsys(&nfs_net_ops);
2192 	if (err < 0)
2193 		goto out9;
2194 
2195 	err = nfs_fscache_register();
2196 	if (err < 0)
2197 		goto out8;
2198 
2199 	err = nfsiod_start();
2200 	if (err)
2201 		goto out7;
2202 
2203 	err = nfs_fs_proc_init();
2204 	if (err)
2205 		goto out6;
2206 
2207 	err = nfs_init_nfspagecache();
2208 	if (err)
2209 		goto out5;
2210 
2211 	err = nfs_init_inodecache();
2212 	if (err)
2213 		goto out4;
2214 
2215 	err = nfs_init_readpagecache();
2216 	if (err)
2217 		goto out3;
2218 
2219 	err = nfs_init_writepagecache();
2220 	if (err)
2221 		goto out2;
2222 
2223 	err = nfs_init_directcache();
2224 	if (err)
2225 		goto out1;
2226 
2227 	rpc_proc_register(&init_net, &nfs_rpcstat);
2228 
2229 	err = register_nfs_fs();
2230 	if (err)
2231 		goto out0;
2232 
2233 	return 0;
2234 out0:
2235 	rpc_proc_unregister(&init_net, "nfs");
2236 	nfs_destroy_directcache();
2237 out1:
2238 	nfs_destroy_writepagecache();
2239 out2:
2240 	nfs_destroy_readpagecache();
2241 out3:
2242 	nfs_destroy_inodecache();
2243 out4:
2244 	nfs_destroy_nfspagecache();
2245 out5:
2246 	nfs_fs_proc_exit();
2247 out6:
2248 	nfsiod_stop();
2249 out7:
2250 	nfs_fscache_unregister();
2251 out8:
2252 	unregister_pernet_subsys(&nfs_net_ops);
2253 out9:
2254 	return err;
2255 }
2256 
2257 static void __exit exit_nfs_fs(void)
2258 {
2259 	nfs_destroy_directcache();
2260 	nfs_destroy_writepagecache();
2261 	nfs_destroy_readpagecache();
2262 	nfs_destroy_inodecache();
2263 	nfs_destroy_nfspagecache();
2264 	nfs_fscache_unregister();
2265 	unregister_pernet_subsys(&nfs_net_ops);
2266 	rpc_proc_unregister(&init_net, "nfs");
2267 	unregister_nfs_fs();
2268 	nfs_fs_proc_exit();
2269 	nfsiod_stop();
2270 }
2271 
2272 /* Not quite true; I just maintain it */
2273 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
2274 MODULE_LICENSE("GPL");
2275 module_param(enable_ino64, bool, 0644);
2276 
2277 module_init(init_nfs_fs)
2278 module_exit(exit_nfs_fs)
2279