xref: /linux/fs/nfs/inode.c (revision 827634added7f38b7d724cab1dccdb2b004c13c3)
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.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 
42 #include <asm/uaccess.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 /**
75  * nfs_wait_bit_killable - helper for functions that are sleeping on bit locks
76  * @word: long word containing the bit lock
77  */
78 int nfs_wait_bit_killable(struct wait_bit_key *key)
79 {
80 	if (fatal_signal_pending(current))
81 		return -ERESTARTSYS;
82 	freezable_schedule_unsafe();
83 	return 0;
84 }
85 EXPORT_SYMBOL_GPL(nfs_wait_bit_killable);
86 
87 /**
88  * nfs_compat_user_ino64 - returns the user-visible inode number
89  * @fileid: 64-bit fileid
90  *
91  * This function returns a 32-bit inode number if the boot parameter
92  * nfs.enable_ino64 is zero.
93  */
94 u64 nfs_compat_user_ino64(u64 fileid)
95 {
96 #ifdef CONFIG_COMPAT
97 	compat_ulong_t ino;
98 #else
99 	unsigned long ino;
100 #endif
101 
102 	if (enable_ino64)
103 		return fileid;
104 	ino = fileid;
105 	if (sizeof(ino) < sizeof(fileid))
106 		ino ^= fileid >> (sizeof(fileid)-sizeof(ino)) * 8;
107 	return ino;
108 }
109 
110 int nfs_drop_inode(struct inode *inode)
111 {
112 	return NFS_STALE(inode) || generic_drop_inode(inode);
113 }
114 EXPORT_SYMBOL_GPL(nfs_drop_inode);
115 
116 void nfs_clear_inode(struct inode *inode)
117 {
118 	/*
119 	 * The following should never happen...
120 	 */
121 	WARN_ON_ONCE(nfs_have_writebacks(inode));
122 	WARN_ON_ONCE(!list_empty(&NFS_I(inode)->open_files));
123 	nfs_zap_acl_cache(inode);
124 	nfs_access_zap_cache(inode);
125 	nfs_fscache_clear_inode(inode);
126 }
127 EXPORT_SYMBOL_GPL(nfs_clear_inode);
128 
129 void nfs_evict_inode(struct inode *inode)
130 {
131 	truncate_inode_pages_final(&inode->i_data);
132 	clear_inode(inode);
133 	nfs_clear_inode(inode);
134 }
135 
136 int nfs_sync_inode(struct inode *inode)
137 {
138 	nfs_inode_dio_wait(inode);
139 	return nfs_wb_all(inode);
140 }
141 EXPORT_SYMBOL_GPL(nfs_sync_inode);
142 
143 /**
144  * nfs_sync_mapping - helper to flush all mmapped dirty data to disk
145  */
146 int nfs_sync_mapping(struct address_space *mapping)
147 {
148 	int ret = 0;
149 
150 	if (mapping->nrpages != 0) {
151 		unmap_mapping_range(mapping, 0, 0, 0);
152 		ret = nfs_wb_all(mapping->host);
153 	}
154 	return ret;
155 }
156 
157 static void nfs_set_cache_invalid(struct inode *inode, unsigned long flags)
158 {
159 	struct nfs_inode *nfsi = NFS_I(inode);
160 
161 	if (inode->i_mapping->nrpages == 0)
162 		flags &= ~NFS_INO_INVALID_DATA;
163 	nfsi->cache_validity |= flags;
164 	if (flags & NFS_INO_INVALID_DATA)
165 		nfs_fscache_invalidate(inode);
166 }
167 
168 /*
169  * Invalidate the local caches
170  */
171 static void nfs_zap_caches_locked(struct inode *inode)
172 {
173 	struct nfs_inode *nfsi = NFS_I(inode);
174 	int mode = inode->i_mode;
175 
176 	nfs_inc_stats(inode, NFSIOS_ATTRINVALIDATE);
177 
178 	nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
179 	nfsi->attrtimeo_timestamp = jiffies;
180 
181 	memset(NFS_I(inode)->cookieverf, 0, sizeof(NFS_I(inode)->cookieverf));
182 	if (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)) {
183 		nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR
184 					| NFS_INO_INVALID_DATA
185 					| NFS_INO_INVALID_ACCESS
186 					| NFS_INO_INVALID_ACL
187 					| NFS_INO_REVAL_PAGECACHE);
188 	} else
189 		nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR
190 					| NFS_INO_INVALID_ACCESS
191 					| NFS_INO_INVALID_ACL
192 					| NFS_INO_REVAL_PAGECACHE);
193 	nfs_zap_label_cache_locked(nfsi);
194 }
195 
196 void nfs_zap_caches(struct inode *inode)
197 {
198 	spin_lock(&inode->i_lock);
199 	nfs_zap_caches_locked(inode);
200 	spin_unlock(&inode->i_lock);
201 }
202 
203 void nfs_zap_mapping(struct inode *inode, struct address_space *mapping)
204 {
205 	if (mapping->nrpages != 0) {
206 		spin_lock(&inode->i_lock);
207 		nfs_set_cache_invalid(inode, NFS_INO_INVALID_DATA);
208 		spin_unlock(&inode->i_lock);
209 	}
210 }
211 
212 void nfs_zap_acl_cache(struct inode *inode)
213 {
214 	void (*clear_acl_cache)(struct inode *);
215 
216 	clear_acl_cache = NFS_PROTO(inode)->clear_acl_cache;
217 	if (clear_acl_cache != NULL)
218 		clear_acl_cache(inode);
219 	spin_lock(&inode->i_lock);
220 	NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_ACL;
221 	spin_unlock(&inode->i_lock);
222 }
223 EXPORT_SYMBOL_GPL(nfs_zap_acl_cache);
224 
225 void nfs_invalidate_atime(struct inode *inode)
226 {
227 	spin_lock(&inode->i_lock);
228 	nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATIME);
229 	spin_unlock(&inode->i_lock);
230 }
231 EXPORT_SYMBOL_GPL(nfs_invalidate_atime);
232 
233 /*
234  * Invalidate, but do not unhash, the inode.
235  * NB: must be called with inode->i_lock held!
236  */
237 static void nfs_invalidate_inode(struct inode *inode)
238 {
239 	set_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
240 	nfs_zap_caches_locked(inode);
241 }
242 
243 struct nfs_find_desc {
244 	struct nfs_fh		*fh;
245 	struct nfs_fattr	*fattr;
246 };
247 
248 /*
249  * In NFSv3 we can have 64bit inode numbers. In order to support
250  * this, and re-exported directories (also seen in NFSv2)
251  * we are forced to allow 2 different inodes to have the same
252  * i_ino.
253  */
254 static int
255 nfs_find_actor(struct inode *inode, void *opaque)
256 {
257 	struct nfs_find_desc	*desc = (struct nfs_find_desc *)opaque;
258 	struct nfs_fh		*fh = desc->fh;
259 	struct nfs_fattr	*fattr = desc->fattr;
260 
261 	if (NFS_FILEID(inode) != fattr->fileid)
262 		return 0;
263 	if ((S_IFMT & inode->i_mode) != (S_IFMT & fattr->mode))
264 		return 0;
265 	if (nfs_compare_fh(NFS_FH(inode), fh))
266 		return 0;
267 	if (is_bad_inode(inode) || NFS_STALE(inode))
268 		return 0;
269 	return 1;
270 }
271 
272 static int
273 nfs_init_locked(struct inode *inode, void *opaque)
274 {
275 	struct nfs_find_desc	*desc = (struct nfs_find_desc *)opaque;
276 	struct nfs_fattr	*fattr = desc->fattr;
277 
278 	set_nfs_fileid(inode, fattr->fileid);
279 	nfs_copy_fh(NFS_FH(inode), desc->fh);
280 	return 0;
281 }
282 
283 #ifdef CONFIG_NFS_V4_SECURITY_LABEL
284 static void nfs_clear_label_invalid(struct inode *inode)
285 {
286 	spin_lock(&inode->i_lock);
287 	NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_LABEL;
288 	spin_unlock(&inode->i_lock);
289 }
290 
291 void nfs_setsecurity(struct inode *inode, struct nfs_fattr *fattr,
292 					struct nfs4_label *label)
293 {
294 	int error;
295 
296 	if (label == NULL)
297 		return;
298 
299 	if ((fattr->valid & NFS_ATTR_FATTR_V4_SECURITY_LABEL) && inode->i_security) {
300 		error = security_inode_notifysecctx(inode, label->label,
301 				label->len);
302 		if (error)
303 			printk(KERN_ERR "%s() %s %d "
304 					"security_inode_notifysecctx() %d\n",
305 					__func__,
306 					(char *)label->label,
307 					label->len, error);
308 		nfs_clear_label_invalid(inode);
309 	}
310 }
311 
312 struct nfs4_label *nfs4_label_alloc(struct nfs_server *server, gfp_t flags)
313 {
314 	struct nfs4_label *label = NULL;
315 	int minor_version = server->nfs_client->cl_minorversion;
316 
317 	if (minor_version < 2)
318 		return label;
319 
320 	if (!(server->caps & NFS_CAP_SECURITY_LABEL))
321 		return label;
322 
323 	label = kzalloc(sizeof(struct nfs4_label), flags);
324 	if (label == NULL)
325 		return ERR_PTR(-ENOMEM);
326 
327 	label->label = kzalloc(NFS4_MAXLABELLEN, flags);
328 	if (label->label == NULL) {
329 		kfree(label);
330 		return ERR_PTR(-ENOMEM);
331 	}
332 	label->len = NFS4_MAXLABELLEN;
333 
334 	return label;
335 }
336 EXPORT_SYMBOL_GPL(nfs4_label_alloc);
337 #else
338 void nfs_setsecurity(struct inode *inode, struct nfs_fattr *fattr,
339 					struct nfs4_label *label)
340 {
341 }
342 #endif
343 EXPORT_SYMBOL_GPL(nfs_setsecurity);
344 
345 /*
346  * This is our front-end to iget that looks up inodes by file handle
347  * instead of inode number.
348  */
349 struct inode *
350 nfs_fhget(struct super_block *sb, struct nfs_fh *fh, struct nfs_fattr *fattr, struct nfs4_label *label)
351 {
352 	struct nfs_find_desc desc = {
353 		.fh	= fh,
354 		.fattr	= fattr
355 	};
356 	struct inode *inode = ERR_PTR(-ENOENT);
357 	unsigned long hash;
358 
359 	nfs_attr_check_mountpoint(sb, fattr);
360 
361 	if (nfs_attr_use_mounted_on_fileid(fattr))
362 		fattr->fileid = fattr->mounted_on_fileid;
363 	else if ((fattr->valid & NFS_ATTR_FATTR_FILEID) == 0)
364 		goto out_no_inode;
365 	if ((fattr->valid & NFS_ATTR_FATTR_TYPE) == 0)
366 		goto out_no_inode;
367 
368 	hash = nfs_fattr_to_ino_t(fattr);
369 
370 	inode = iget5_locked(sb, hash, nfs_find_actor, nfs_init_locked, &desc);
371 	if (inode == NULL) {
372 		inode = ERR_PTR(-ENOMEM);
373 		goto out_no_inode;
374 	}
375 
376 	if (inode->i_state & I_NEW) {
377 		struct nfs_inode *nfsi = NFS_I(inode);
378 		unsigned long now = jiffies;
379 
380 		/* We set i_ino for the few things that still rely on it,
381 		 * such as stat(2) */
382 		inode->i_ino = hash;
383 
384 		/* We can't support update_atime(), since the server will reset it */
385 		inode->i_flags |= S_NOATIME|S_NOCMTIME;
386 		inode->i_mode = fattr->mode;
387 		if ((fattr->valid & NFS_ATTR_FATTR_MODE) == 0
388 				&& nfs_server_capable(inode, NFS_CAP_MODE))
389 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR);
390 		/* Why so? Because we want revalidate for devices/FIFOs, and
391 		 * that's precisely what we have in nfs_file_inode_operations.
392 		 */
393 		inode->i_op = NFS_SB(sb)->nfs_client->rpc_ops->file_inode_ops;
394 		if (S_ISREG(inode->i_mode)) {
395 			inode->i_fop = NFS_SB(sb)->nfs_client->rpc_ops->file_ops;
396 			inode->i_data.a_ops = &nfs_file_aops;
397 		} else if (S_ISDIR(inode->i_mode)) {
398 			inode->i_op = NFS_SB(sb)->nfs_client->rpc_ops->dir_inode_ops;
399 			inode->i_fop = &nfs_dir_operations;
400 			inode->i_data.a_ops = &nfs_dir_aops;
401 			/* Deal with crossing mountpoints */
402 			if (fattr->valid & NFS_ATTR_FATTR_MOUNTPOINT ||
403 					fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL) {
404 				if (fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL)
405 					inode->i_op = &nfs_referral_inode_operations;
406 				else
407 					inode->i_op = &nfs_mountpoint_inode_operations;
408 				inode->i_fop = NULL;
409 				inode->i_flags |= S_AUTOMOUNT;
410 			}
411 		} else if (S_ISLNK(inode->i_mode))
412 			inode->i_op = &nfs_symlink_inode_operations;
413 		else
414 			init_special_inode(inode, inode->i_mode, fattr->rdev);
415 
416 		memset(&inode->i_atime, 0, sizeof(inode->i_atime));
417 		memset(&inode->i_mtime, 0, sizeof(inode->i_mtime));
418 		memset(&inode->i_ctime, 0, sizeof(inode->i_ctime));
419 		inode->i_version = 0;
420 		inode->i_size = 0;
421 		clear_nlink(inode);
422 		inode->i_uid = make_kuid(&init_user_ns, -2);
423 		inode->i_gid = make_kgid(&init_user_ns, -2);
424 		inode->i_blocks = 0;
425 		memset(nfsi->cookieverf, 0, sizeof(nfsi->cookieverf));
426 		nfsi->write_io = 0;
427 		nfsi->read_io = 0;
428 
429 		nfsi->read_cache_jiffies = fattr->time_start;
430 		nfsi->attr_gencount = fattr->gencount;
431 		if (fattr->valid & NFS_ATTR_FATTR_ATIME)
432 			inode->i_atime = fattr->atime;
433 		else if (nfs_server_capable(inode, NFS_CAP_ATIME))
434 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR);
435 		if (fattr->valid & NFS_ATTR_FATTR_MTIME)
436 			inode->i_mtime = fattr->mtime;
437 		else if (nfs_server_capable(inode, NFS_CAP_MTIME))
438 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR);
439 		if (fattr->valid & NFS_ATTR_FATTR_CTIME)
440 			inode->i_ctime = fattr->ctime;
441 		else if (nfs_server_capable(inode, NFS_CAP_CTIME))
442 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR);
443 		if (fattr->valid & NFS_ATTR_FATTR_CHANGE)
444 			inode->i_version = fattr->change_attr;
445 		else if (nfs_server_capable(inode, NFS_CAP_CHANGE_ATTR))
446 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR);
447 		if (fattr->valid & NFS_ATTR_FATTR_SIZE)
448 			inode->i_size = nfs_size_to_loff_t(fattr->size);
449 		else
450 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR
451 				| NFS_INO_REVAL_PAGECACHE);
452 		if (fattr->valid & NFS_ATTR_FATTR_NLINK)
453 			set_nlink(inode, fattr->nlink);
454 		else if (nfs_server_capable(inode, NFS_CAP_NLINK))
455 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR);
456 		if (fattr->valid & NFS_ATTR_FATTR_OWNER)
457 			inode->i_uid = fattr->uid;
458 		else if (nfs_server_capable(inode, NFS_CAP_OWNER))
459 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR);
460 		if (fattr->valid & NFS_ATTR_FATTR_GROUP)
461 			inode->i_gid = fattr->gid;
462 		else if (nfs_server_capable(inode, NFS_CAP_OWNER_GROUP))
463 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR);
464 		if (fattr->valid & NFS_ATTR_FATTR_BLOCKS_USED)
465 			inode->i_blocks = fattr->du.nfs2.blocks;
466 		if (fattr->valid & NFS_ATTR_FATTR_SPACE_USED) {
467 			/*
468 			 * report the blocks in 512byte units
469 			 */
470 			inode->i_blocks = nfs_calc_block_size(fattr->du.nfs3.used);
471 		}
472 
473 		nfs_setsecurity(inode, fattr, label);
474 
475 		nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
476 		nfsi->attrtimeo_timestamp = now;
477 		nfsi->access_cache = RB_ROOT;
478 
479 		nfs_fscache_init_inode(inode);
480 
481 		unlock_new_inode(inode);
482 	} else
483 		nfs_refresh_inode(inode, fattr);
484 	dprintk("NFS: nfs_fhget(%s/%Lu fh_crc=0x%08x ct=%d)\n",
485 		inode->i_sb->s_id,
486 		(unsigned long long)NFS_FILEID(inode),
487 		nfs_display_fhandle_hash(fh),
488 		atomic_read(&inode->i_count));
489 
490 out:
491 	return inode;
492 
493 out_no_inode:
494 	dprintk("nfs_fhget: iget failed with error %ld\n", PTR_ERR(inode));
495 	goto out;
496 }
497 EXPORT_SYMBOL_GPL(nfs_fhget);
498 
499 #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)
500 
501 int
502 nfs_setattr(struct dentry *dentry, struct iattr *attr)
503 {
504 	struct inode *inode = d_inode(dentry);
505 	struct nfs_fattr *fattr;
506 	int error = -ENOMEM;
507 
508 	nfs_inc_stats(inode, NFSIOS_VFSSETATTR);
509 
510 	/* skip mode change if it's just for clearing setuid/setgid */
511 	if (attr->ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
512 		attr->ia_valid &= ~ATTR_MODE;
513 
514 	if (attr->ia_valid & ATTR_SIZE) {
515 		loff_t i_size;
516 
517 		BUG_ON(!S_ISREG(inode->i_mode));
518 
519 		i_size = i_size_read(inode);
520 		if (attr->ia_size == i_size)
521 			attr->ia_valid &= ~ATTR_SIZE;
522 		else if (attr->ia_size < i_size && IS_SWAPFILE(inode))
523 			return -ETXTBSY;
524 	}
525 
526 	/* Optimization: if the end result is no change, don't RPC */
527 	attr->ia_valid &= NFS_VALID_ATTRS;
528 	if ((attr->ia_valid & ~(ATTR_FILE|ATTR_OPEN)) == 0)
529 		return 0;
530 
531 	trace_nfs_setattr_enter(inode);
532 
533 	/* Write all dirty data */
534 	if (S_ISREG(inode->i_mode))
535 		nfs_sync_inode(inode);
536 
537 	fattr = nfs_alloc_fattr();
538 	if (fattr == NULL)
539 		goto out;
540 	/*
541 	 * Return any delegations if we're going to change ACLs
542 	 */
543 	if ((attr->ia_valid & (ATTR_MODE|ATTR_UID|ATTR_GID)) != 0)
544 		NFS_PROTO(inode)->return_delegation(inode);
545 	error = NFS_PROTO(inode)->setattr(dentry, fattr, attr);
546 	if (error == 0)
547 		error = nfs_refresh_inode(inode, fattr);
548 	nfs_free_fattr(fattr);
549 out:
550 	trace_nfs_setattr_exit(inode, error);
551 	return error;
552 }
553 EXPORT_SYMBOL_GPL(nfs_setattr);
554 
555 /**
556  * nfs_vmtruncate - unmap mappings "freed" by truncate() syscall
557  * @inode: inode of the file used
558  * @offset: file offset to start truncating
559  *
560  * This is a copy of the common vmtruncate, but with the locking
561  * corrected to take into account the fact that NFS requires
562  * inode->i_size to be updated under the inode->i_lock.
563  * Note: must be called with inode->i_lock held!
564  */
565 static int nfs_vmtruncate(struct inode * inode, loff_t offset)
566 {
567 	int err;
568 
569 	err = inode_newsize_ok(inode, offset);
570 	if (err)
571 		goto out;
572 
573 	i_size_write(inode, offset);
574 	/* Optimisation */
575 	if (offset == 0)
576 		NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_DATA;
577 
578 	spin_unlock(&inode->i_lock);
579 	truncate_pagecache(inode, offset);
580 	spin_lock(&inode->i_lock);
581 out:
582 	return err;
583 }
584 
585 /**
586  * nfs_setattr_update_inode - Update inode metadata after a setattr call.
587  * @inode: pointer to struct inode
588  * @attr: pointer to struct iattr
589  *
590  * Note: we do this in the *proc.c in order to ensure that
591  *       it works for things like exclusive creates too.
592  */
593 void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr,
594 		struct nfs_fattr *fattr)
595 {
596 	/* Barrier: bump the attribute generation count. */
597 	nfs_fattr_set_barrier(fattr);
598 
599 	spin_lock(&inode->i_lock);
600 	NFS_I(inode)->attr_gencount = fattr->gencount;
601 	if ((attr->ia_valid & (ATTR_MODE|ATTR_UID|ATTR_GID)) != 0) {
602 		if ((attr->ia_valid & ATTR_MODE) != 0) {
603 			int mode = attr->ia_mode & S_IALLUGO;
604 			mode |= inode->i_mode & ~S_IALLUGO;
605 			inode->i_mode = mode;
606 		}
607 		if ((attr->ia_valid & ATTR_UID) != 0)
608 			inode->i_uid = attr->ia_uid;
609 		if ((attr->ia_valid & ATTR_GID) != 0)
610 			inode->i_gid = attr->ia_gid;
611 		nfs_set_cache_invalid(inode, NFS_INO_INVALID_ACCESS
612 				| NFS_INO_INVALID_ACL);
613 	}
614 	if ((attr->ia_valid & ATTR_SIZE) != 0) {
615 		nfs_inc_stats(inode, NFSIOS_SETATTRTRUNC);
616 		nfs_vmtruncate(inode, attr->ia_size);
617 	}
618 	nfs_update_inode(inode, fattr);
619 	spin_unlock(&inode->i_lock);
620 }
621 EXPORT_SYMBOL_GPL(nfs_setattr_update_inode);
622 
623 static void nfs_request_parent_use_readdirplus(struct dentry *dentry)
624 {
625 	struct dentry *parent;
626 
627 	parent = dget_parent(dentry);
628 	nfs_force_use_readdirplus(d_inode(parent));
629 	dput(parent);
630 }
631 
632 static bool nfs_need_revalidate_inode(struct inode *inode)
633 {
634 	if (NFS_I(inode)->cache_validity &
635 			(NFS_INO_INVALID_ATTR|NFS_INO_INVALID_LABEL))
636 		return true;
637 	if (nfs_attribute_cache_expired(inode))
638 		return true;
639 	return false;
640 }
641 
642 int nfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
643 {
644 	struct inode *inode = d_inode(dentry);
645 	int need_atime = NFS_I(inode)->cache_validity & NFS_INO_INVALID_ATIME;
646 	int err = 0;
647 
648 	trace_nfs_getattr_enter(inode);
649 	/* Flush out writes to the server in order to update c/mtime.  */
650 	if (S_ISREG(inode->i_mode)) {
651 		mutex_lock(&inode->i_mutex);
652 		err = nfs_sync_inode(inode);
653 		mutex_unlock(&inode->i_mutex);
654 		if (err)
655 			goto out;
656 	}
657 
658 	/*
659 	 * We may force a getattr if the user cares about atime.
660 	 *
661 	 * Note that we only have to check the vfsmount flags here:
662 	 *  - NFS always sets S_NOATIME by so checking it would give a
663 	 *    bogus result
664 	 *  - NFS never sets MS_NOATIME or MS_NODIRATIME so there is
665 	 *    no point in checking those.
666 	 */
667  	if ((mnt->mnt_flags & MNT_NOATIME) ||
668  	    ((mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode)))
669 		need_atime = 0;
670 
671 	if (need_atime || nfs_need_revalidate_inode(inode)) {
672 		struct nfs_server *server = NFS_SERVER(inode);
673 
674 		if (server->caps & NFS_CAP_READDIRPLUS)
675 			nfs_request_parent_use_readdirplus(dentry);
676 		err = __nfs_revalidate_inode(server, inode);
677 	}
678 	if (!err) {
679 		generic_fillattr(inode, stat);
680 		stat->ino = nfs_compat_user_ino64(NFS_FILEID(inode));
681 	}
682 out:
683 	trace_nfs_getattr_exit(inode, err);
684 	return err;
685 }
686 EXPORT_SYMBOL_GPL(nfs_getattr);
687 
688 static void nfs_init_lock_context(struct nfs_lock_context *l_ctx)
689 {
690 	atomic_set(&l_ctx->count, 1);
691 	l_ctx->lockowner.l_owner = current->files;
692 	l_ctx->lockowner.l_pid = current->tgid;
693 	INIT_LIST_HEAD(&l_ctx->list);
694 	nfs_iocounter_init(&l_ctx->io_count);
695 }
696 
697 static struct nfs_lock_context *__nfs_find_lock_context(struct nfs_open_context *ctx)
698 {
699 	struct nfs_lock_context *head = &ctx->lock_context;
700 	struct nfs_lock_context *pos = head;
701 
702 	do {
703 		if (pos->lockowner.l_owner != current->files)
704 			continue;
705 		if (pos->lockowner.l_pid != current->tgid)
706 			continue;
707 		atomic_inc(&pos->count);
708 		return pos;
709 	} while ((pos = list_entry(pos->list.next, typeof(*pos), list)) != head);
710 	return NULL;
711 }
712 
713 struct nfs_lock_context *nfs_get_lock_context(struct nfs_open_context *ctx)
714 {
715 	struct nfs_lock_context *res, *new = NULL;
716 	struct inode *inode = d_inode(ctx->dentry);
717 
718 	spin_lock(&inode->i_lock);
719 	res = __nfs_find_lock_context(ctx);
720 	if (res == NULL) {
721 		spin_unlock(&inode->i_lock);
722 		new = kmalloc(sizeof(*new), GFP_KERNEL);
723 		if (new == NULL)
724 			return ERR_PTR(-ENOMEM);
725 		nfs_init_lock_context(new);
726 		spin_lock(&inode->i_lock);
727 		res = __nfs_find_lock_context(ctx);
728 		if (res == NULL) {
729 			list_add_tail(&new->list, &ctx->lock_context.list);
730 			new->open_context = ctx;
731 			res = new;
732 			new = NULL;
733 		}
734 	}
735 	spin_unlock(&inode->i_lock);
736 	kfree(new);
737 	return res;
738 }
739 EXPORT_SYMBOL_GPL(nfs_get_lock_context);
740 
741 void nfs_put_lock_context(struct nfs_lock_context *l_ctx)
742 {
743 	struct nfs_open_context *ctx = l_ctx->open_context;
744 	struct inode *inode = d_inode(ctx->dentry);
745 
746 	if (!atomic_dec_and_lock(&l_ctx->count, &inode->i_lock))
747 		return;
748 	list_del(&l_ctx->list);
749 	spin_unlock(&inode->i_lock);
750 	kfree(l_ctx);
751 }
752 EXPORT_SYMBOL_GPL(nfs_put_lock_context);
753 
754 /**
755  * nfs_close_context - Common close_context() routine NFSv2/v3
756  * @ctx: pointer to context
757  * @is_sync: is this a synchronous close
758  *
759  * always ensure that the attributes are up to date if we're mounted
760  * with close-to-open semantics
761  */
762 void nfs_close_context(struct nfs_open_context *ctx, int is_sync)
763 {
764 	struct inode *inode;
765 	struct nfs_server *server;
766 
767 	if (!(ctx->mode & FMODE_WRITE))
768 		return;
769 	if (!is_sync)
770 		return;
771 	inode = d_inode(ctx->dentry);
772 	if (!list_empty(&NFS_I(inode)->open_files))
773 		return;
774 	server = NFS_SERVER(inode);
775 	if (server->flags & NFS_MOUNT_NOCTO)
776 		return;
777 	nfs_revalidate_inode(server, inode);
778 }
779 EXPORT_SYMBOL_GPL(nfs_close_context);
780 
781 struct nfs_open_context *alloc_nfs_open_context(struct dentry *dentry, fmode_t f_mode)
782 {
783 	struct nfs_open_context *ctx;
784 	struct rpc_cred *cred = rpc_lookup_cred();
785 	if (IS_ERR(cred))
786 		return ERR_CAST(cred);
787 
788 	ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
789 	if (!ctx) {
790 		put_rpccred(cred);
791 		return ERR_PTR(-ENOMEM);
792 	}
793 	nfs_sb_active(dentry->d_sb);
794 	ctx->dentry = dget(dentry);
795 	ctx->cred = cred;
796 	ctx->state = NULL;
797 	ctx->mode = f_mode;
798 	ctx->flags = 0;
799 	ctx->error = 0;
800 	nfs_init_lock_context(&ctx->lock_context);
801 	ctx->lock_context.open_context = ctx;
802 	INIT_LIST_HEAD(&ctx->list);
803 	ctx->mdsthreshold = NULL;
804 	return ctx;
805 }
806 EXPORT_SYMBOL_GPL(alloc_nfs_open_context);
807 
808 struct nfs_open_context *get_nfs_open_context(struct nfs_open_context *ctx)
809 {
810 	if (ctx != NULL)
811 		atomic_inc(&ctx->lock_context.count);
812 	return ctx;
813 }
814 EXPORT_SYMBOL_GPL(get_nfs_open_context);
815 
816 static void __put_nfs_open_context(struct nfs_open_context *ctx, int is_sync)
817 {
818 	struct inode *inode = d_inode(ctx->dentry);
819 	struct super_block *sb = ctx->dentry->d_sb;
820 
821 	if (!list_empty(&ctx->list)) {
822 		if (!atomic_dec_and_lock(&ctx->lock_context.count, &inode->i_lock))
823 			return;
824 		list_del(&ctx->list);
825 		spin_unlock(&inode->i_lock);
826 	} else if (!atomic_dec_and_test(&ctx->lock_context.count))
827 		return;
828 	if (inode != NULL)
829 		NFS_PROTO(inode)->close_context(ctx, is_sync);
830 	if (ctx->cred != NULL)
831 		put_rpccred(ctx->cred);
832 	dput(ctx->dentry);
833 	nfs_sb_deactive(sb);
834 	kfree(ctx->mdsthreshold);
835 	kfree(ctx);
836 }
837 
838 void put_nfs_open_context(struct nfs_open_context *ctx)
839 {
840 	__put_nfs_open_context(ctx, 0);
841 }
842 EXPORT_SYMBOL_GPL(put_nfs_open_context);
843 
844 /*
845  * Ensure that mmap has a recent RPC credential for use when writing out
846  * shared pages
847  */
848 void nfs_inode_attach_open_context(struct nfs_open_context *ctx)
849 {
850 	struct inode *inode = d_inode(ctx->dentry);
851 	struct nfs_inode *nfsi = NFS_I(inode);
852 
853 	spin_lock(&inode->i_lock);
854 	list_add(&ctx->list, &nfsi->open_files);
855 	spin_unlock(&inode->i_lock);
856 }
857 EXPORT_SYMBOL_GPL(nfs_inode_attach_open_context);
858 
859 void nfs_file_set_open_context(struct file *filp, struct nfs_open_context *ctx)
860 {
861 	filp->private_data = get_nfs_open_context(ctx);
862 	if (list_empty(&ctx->list))
863 		nfs_inode_attach_open_context(ctx);
864 }
865 EXPORT_SYMBOL_GPL(nfs_file_set_open_context);
866 
867 /*
868  * Given an inode, search for an open context with the desired characteristics
869  */
870 struct nfs_open_context *nfs_find_open_context(struct inode *inode, struct rpc_cred *cred, fmode_t mode)
871 {
872 	struct nfs_inode *nfsi = NFS_I(inode);
873 	struct nfs_open_context *pos, *ctx = NULL;
874 
875 	spin_lock(&inode->i_lock);
876 	list_for_each_entry(pos, &nfsi->open_files, list) {
877 		if (cred != NULL && pos->cred != cred)
878 			continue;
879 		if ((pos->mode & (FMODE_READ|FMODE_WRITE)) != mode)
880 			continue;
881 		ctx = get_nfs_open_context(pos);
882 		break;
883 	}
884 	spin_unlock(&inode->i_lock);
885 	return ctx;
886 }
887 
888 static void nfs_file_clear_open_context(struct file *filp)
889 {
890 	struct nfs_open_context *ctx = nfs_file_open_context(filp);
891 
892 	if (ctx) {
893 		struct inode *inode = d_inode(ctx->dentry);
894 
895 		filp->private_data = NULL;
896 		spin_lock(&inode->i_lock);
897 		list_move_tail(&ctx->list, &NFS_I(inode)->open_files);
898 		spin_unlock(&inode->i_lock);
899 		__put_nfs_open_context(ctx, filp->f_flags & O_DIRECT ? 0 : 1);
900 	}
901 }
902 
903 /*
904  * These allocate and release file read/write context information.
905  */
906 int nfs_open(struct inode *inode, struct file *filp)
907 {
908 	struct nfs_open_context *ctx;
909 
910 	ctx = alloc_nfs_open_context(filp->f_path.dentry, filp->f_mode);
911 	if (IS_ERR(ctx))
912 		return PTR_ERR(ctx);
913 	nfs_file_set_open_context(filp, ctx);
914 	put_nfs_open_context(ctx);
915 	nfs_fscache_open_file(inode, filp);
916 	return 0;
917 }
918 
919 int nfs_release(struct inode *inode, struct file *filp)
920 {
921 	nfs_file_clear_open_context(filp);
922 	return 0;
923 }
924 
925 /*
926  * This function is called whenever some part of NFS notices that
927  * the cached attributes have to be refreshed.
928  */
929 int
930 __nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
931 {
932 	int		 status = -ESTALE;
933 	struct nfs4_label *label = NULL;
934 	struct nfs_fattr *fattr = NULL;
935 	struct nfs_inode *nfsi = NFS_I(inode);
936 
937 	dfprintk(PAGECACHE, "NFS: revalidating (%s/%Lu)\n",
938 		inode->i_sb->s_id, (unsigned long long)NFS_FILEID(inode));
939 
940 	trace_nfs_revalidate_inode_enter(inode);
941 
942 	if (is_bad_inode(inode))
943 		goto out;
944 	if (NFS_STALE(inode))
945 		goto out;
946 
947 	status = -ENOMEM;
948 	fattr = nfs_alloc_fattr();
949 	if (fattr == NULL)
950 		goto out;
951 
952 	nfs_inc_stats(inode, NFSIOS_INODEREVALIDATE);
953 
954 	label = nfs4_label_alloc(NFS_SERVER(inode), GFP_KERNEL);
955 	if (IS_ERR(label)) {
956 		status = PTR_ERR(label);
957 		goto out;
958 	}
959 
960 	status = NFS_PROTO(inode)->getattr(server, NFS_FH(inode), fattr, label);
961 	if (status != 0) {
962 		dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Lu) getattr failed, error=%d\n",
963 			 inode->i_sb->s_id,
964 			 (unsigned long long)NFS_FILEID(inode), status);
965 		if (status == -ESTALE) {
966 			nfs_zap_caches(inode);
967 			if (!S_ISDIR(inode->i_mode))
968 				set_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
969 		}
970 		goto err_out;
971 	}
972 
973 	status = nfs_refresh_inode(inode, fattr);
974 	if (status) {
975 		dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Lu) refresh failed, error=%d\n",
976 			 inode->i_sb->s_id,
977 			 (unsigned long long)NFS_FILEID(inode), status);
978 		goto err_out;
979 	}
980 
981 	if (nfsi->cache_validity & NFS_INO_INVALID_ACL)
982 		nfs_zap_acl_cache(inode);
983 
984 	nfs_setsecurity(inode, fattr, label);
985 
986 	dfprintk(PAGECACHE, "NFS: (%s/%Lu) revalidation complete\n",
987 		inode->i_sb->s_id,
988 		(unsigned long long)NFS_FILEID(inode));
989 
990 err_out:
991 	nfs4_label_free(label);
992 out:
993 	nfs_free_fattr(fattr);
994 	trace_nfs_revalidate_inode_exit(inode, status);
995 	return status;
996 }
997 
998 int nfs_attribute_timeout(struct inode *inode)
999 {
1000 	struct nfs_inode *nfsi = NFS_I(inode);
1001 
1002 	return !time_in_range_open(jiffies, nfsi->read_cache_jiffies, nfsi->read_cache_jiffies + nfsi->attrtimeo);
1003 }
1004 
1005 int nfs_attribute_cache_expired(struct inode *inode)
1006 {
1007 	if (nfs_have_delegated_attributes(inode))
1008 		return 0;
1009 	return nfs_attribute_timeout(inode);
1010 }
1011 
1012 /**
1013  * nfs_revalidate_inode - Revalidate the inode attributes
1014  * @server - pointer to nfs_server struct
1015  * @inode - pointer to inode struct
1016  *
1017  * Updates inode attribute information by retrieving the data from the server.
1018  */
1019 int nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
1020 {
1021 	if (!nfs_need_revalidate_inode(inode))
1022 		return NFS_STALE(inode) ? -ESTALE : 0;
1023 	return __nfs_revalidate_inode(server, inode);
1024 }
1025 EXPORT_SYMBOL_GPL(nfs_revalidate_inode);
1026 
1027 int nfs_revalidate_inode_rcu(struct nfs_server *server, struct inode *inode)
1028 {
1029 	if (!(NFS_I(inode)->cache_validity &
1030 			(NFS_INO_INVALID_ATTR|NFS_INO_INVALID_LABEL))
1031 			&& !nfs_attribute_cache_expired(inode))
1032 		return NFS_STALE(inode) ? -ESTALE : 0;
1033 	return -ECHILD;
1034 }
1035 
1036 static int nfs_invalidate_mapping(struct inode *inode, struct address_space *mapping)
1037 {
1038 	struct nfs_inode *nfsi = NFS_I(inode);
1039 	int ret;
1040 
1041 	if (mapping->nrpages != 0) {
1042 		if (S_ISREG(inode->i_mode)) {
1043 			unmap_mapping_range(mapping, 0, 0, 0);
1044 			ret = nfs_sync_mapping(mapping);
1045 			if (ret < 0)
1046 				return ret;
1047 		}
1048 		ret = invalidate_inode_pages2(mapping);
1049 		if (ret < 0)
1050 			return ret;
1051 	}
1052 	if (S_ISDIR(inode->i_mode)) {
1053 		spin_lock(&inode->i_lock);
1054 		memset(nfsi->cookieverf, 0, sizeof(nfsi->cookieverf));
1055 		spin_unlock(&inode->i_lock);
1056 	}
1057 	nfs_inc_stats(inode, NFSIOS_DATAINVALIDATE);
1058 	nfs_fscache_wait_on_invalidate(inode);
1059 
1060 	dfprintk(PAGECACHE, "NFS: (%s/%Lu) data cache invalidated\n",
1061 			inode->i_sb->s_id,
1062 			(unsigned long long)NFS_FILEID(inode));
1063 	return 0;
1064 }
1065 
1066 static bool nfs_mapping_need_revalidate_inode(struct inode *inode)
1067 {
1068 	if (nfs_have_delegated_attributes(inode))
1069 		return false;
1070 	return (NFS_I(inode)->cache_validity & NFS_INO_REVAL_PAGECACHE)
1071 		|| nfs_attribute_timeout(inode)
1072 		|| NFS_STALE(inode);
1073 }
1074 
1075 /**
1076  * __nfs_revalidate_mapping - Revalidate the pagecache
1077  * @inode - pointer to host inode
1078  * @mapping - pointer to mapping
1079  * @may_lock - take inode->i_mutex?
1080  */
1081 static int __nfs_revalidate_mapping(struct inode *inode,
1082 		struct address_space *mapping,
1083 		bool may_lock)
1084 {
1085 	struct nfs_inode *nfsi = NFS_I(inode);
1086 	unsigned long *bitlock = &nfsi->flags;
1087 	int ret = 0;
1088 
1089 	/* swapfiles are not supposed to be shared. */
1090 	if (IS_SWAPFILE(inode))
1091 		goto out;
1092 
1093 	if (nfs_mapping_need_revalidate_inode(inode)) {
1094 		ret = __nfs_revalidate_inode(NFS_SERVER(inode), inode);
1095 		if (ret < 0)
1096 			goto out;
1097 	}
1098 
1099 	/*
1100 	 * We must clear NFS_INO_INVALID_DATA first to ensure that
1101 	 * invalidations that come in while we're shooting down the mappings
1102 	 * are respected. But, that leaves a race window where one revalidator
1103 	 * can clear the flag, and then another checks it before the mapping
1104 	 * gets invalidated. Fix that by serializing access to this part of
1105 	 * the function.
1106 	 *
1107 	 * At the same time, we need to allow other tasks to see whether we
1108 	 * might be in the middle of invalidating the pages, so we only set
1109 	 * the bit lock here if it looks like we're going to be doing that.
1110 	 */
1111 	for (;;) {
1112 		ret = wait_on_bit_action(bitlock, NFS_INO_INVALIDATING,
1113 					 nfs_wait_bit_killable, TASK_KILLABLE);
1114 		if (ret)
1115 			goto out;
1116 		spin_lock(&inode->i_lock);
1117 		if (test_bit(NFS_INO_INVALIDATING, bitlock)) {
1118 			spin_unlock(&inode->i_lock);
1119 			continue;
1120 		}
1121 		if (nfsi->cache_validity & NFS_INO_INVALID_DATA)
1122 			break;
1123 		spin_unlock(&inode->i_lock);
1124 		goto out;
1125 	}
1126 
1127 	set_bit(NFS_INO_INVALIDATING, bitlock);
1128 	smp_wmb();
1129 	nfsi->cache_validity &= ~NFS_INO_INVALID_DATA;
1130 	spin_unlock(&inode->i_lock);
1131 	trace_nfs_invalidate_mapping_enter(inode);
1132 	if (may_lock) {
1133 		mutex_lock(&inode->i_mutex);
1134 		ret = nfs_invalidate_mapping(inode, mapping);
1135 		mutex_unlock(&inode->i_mutex);
1136 	} else
1137 		ret = nfs_invalidate_mapping(inode, mapping);
1138 	trace_nfs_invalidate_mapping_exit(inode, ret);
1139 
1140 	clear_bit_unlock(NFS_INO_INVALIDATING, bitlock);
1141 	smp_mb__after_atomic();
1142 	wake_up_bit(bitlock, NFS_INO_INVALIDATING);
1143 out:
1144 	return ret;
1145 }
1146 
1147 /**
1148  * nfs_revalidate_mapping - Revalidate the pagecache
1149  * @inode - pointer to host inode
1150  * @mapping - pointer to mapping
1151  */
1152 int nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping)
1153 {
1154 	return __nfs_revalidate_mapping(inode, mapping, false);
1155 }
1156 
1157 /**
1158  * nfs_revalidate_mapping_protected - Revalidate the pagecache
1159  * @inode - pointer to host inode
1160  * @mapping - pointer to mapping
1161  *
1162  * Differs from nfs_revalidate_mapping() in that it grabs the inode->i_mutex
1163  * while invalidating the mapping.
1164  */
1165 int nfs_revalidate_mapping_protected(struct inode *inode, struct address_space *mapping)
1166 {
1167 	return __nfs_revalidate_mapping(inode, mapping, true);
1168 }
1169 
1170 static unsigned long nfs_wcc_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1171 {
1172 	struct nfs_inode *nfsi = NFS_I(inode);
1173 	unsigned long ret = 0;
1174 
1175 	if ((fattr->valid & NFS_ATTR_FATTR_PRECHANGE)
1176 			&& (fattr->valid & NFS_ATTR_FATTR_CHANGE)
1177 			&& inode->i_version == fattr->pre_change_attr) {
1178 		inode->i_version = fattr->change_attr;
1179 		if (S_ISDIR(inode->i_mode))
1180 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_DATA);
1181 		ret |= NFS_INO_INVALID_ATTR;
1182 	}
1183 	/* If we have atomic WCC data, we may update some attributes */
1184 	if ((fattr->valid & NFS_ATTR_FATTR_PRECTIME)
1185 			&& (fattr->valid & NFS_ATTR_FATTR_CTIME)
1186 			&& timespec_equal(&inode->i_ctime, &fattr->pre_ctime)) {
1187 		memcpy(&inode->i_ctime, &fattr->ctime, sizeof(inode->i_ctime));
1188 		ret |= NFS_INO_INVALID_ATTR;
1189 	}
1190 
1191 	if ((fattr->valid & NFS_ATTR_FATTR_PREMTIME)
1192 			&& (fattr->valid & NFS_ATTR_FATTR_MTIME)
1193 			&& timespec_equal(&inode->i_mtime, &fattr->pre_mtime)) {
1194 		memcpy(&inode->i_mtime, &fattr->mtime, sizeof(inode->i_mtime));
1195 		if (S_ISDIR(inode->i_mode))
1196 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_DATA);
1197 		ret |= NFS_INO_INVALID_ATTR;
1198 	}
1199 	if ((fattr->valid & NFS_ATTR_FATTR_PRESIZE)
1200 			&& (fattr->valid & NFS_ATTR_FATTR_SIZE)
1201 			&& i_size_read(inode) == nfs_size_to_loff_t(fattr->pre_size)
1202 			&& nfsi->nrequests == 0) {
1203 		i_size_write(inode, nfs_size_to_loff_t(fattr->size));
1204 		ret |= NFS_INO_INVALID_ATTR;
1205 	}
1206 
1207 	return ret;
1208 }
1209 
1210 /**
1211  * nfs_check_inode_attributes - verify consistency of the inode attribute cache
1212  * @inode - pointer to inode
1213  * @fattr - updated attributes
1214  *
1215  * Verifies the attribute cache. If we have just changed the attributes,
1216  * so that fattr carries weak cache consistency data, then it may
1217  * also update the ctime/mtime/change_attribute.
1218  */
1219 static int nfs_check_inode_attributes(struct inode *inode, struct nfs_fattr *fattr)
1220 {
1221 	struct nfs_inode *nfsi = NFS_I(inode);
1222 	loff_t cur_size, new_isize;
1223 	unsigned long invalid = 0;
1224 
1225 
1226 	if (nfs_have_delegated_attributes(inode))
1227 		return 0;
1228 	/* Has the inode gone and changed behind our back? */
1229 	if ((fattr->valid & NFS_ATTR_FATTR_FILEID) && nfsi->fileid != fattr->fileid)
1230 		return -EIO;
1231 	if ((fattr->valid & NFS_ATTR_FATTR_TYPE) && (inode->i_mode & S_IFMT) != (fattr->mode & S_IFMT))
1232 		return -EIO;
1233 
1234 	if ((fattr->valid & NFS_ATTR_FATTR_CHANGE) != 0 &&
1235 			inode->i_version != fattr->change_attr)
1236 		invalid |= NFS_INO_INVALID_ATTR|NFS_INO_REVAL_PAGECACHE;
1237 
1238 	/* Verify a few of the more important attributes */
1239 	if ((fattr->valid & NFS_ATTR_FATTR_MTIME) && !timespec_equal(&inode->i_mtime, &fattr->mtime))
1240 		invalid |= NFS_INO_INVALID_ATTR;
1241 
1242 	if (fattr->valid & NFS_ATTR_FATTR_SIZE) {
1243 		cur_size = i_size_read(inode);
1244 		new_isize = nfs_size_to_loff_t(fattr->size);
1245 		if (cur_size != new_isize && nfsi->nrequests == 0)
1246 			invalid |= NFS_INO_INVALID_ATTR|NFS_INO_REVAL_PAGECACHE;
1247 	}
1248 
1249 	/* Have any file permissions changed? */
1250 	if ((fattr->valid & NFS_ATTR_FATTR_MODE) && (inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO))
1251 		invalid |= NFS_INO_INVALID_ATTR | NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL;
1252 	if ((fattr->valid & NFS_ATTR_FATTR_OWNER) && !uid_eq(inode->i_uid, fattr->uid))
1253 		invalid |= NFS_INO_INVALID_ATTR | NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL;
1254 	if ((fattr->valid & NFS_ATTR_FATTR_GROUP) && !gid_eq(inode->i_gid, fattr->gid))
1255 		invalid |= NFS_INO_INVALID_ATTR | NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL;
1256 
1257 	/* Has the link count changed? */
1258 	if ((fattr->valid & NFS_ATTR_FATTR_NLINK) && inode->i_nlink != fattr->nlink)
1259 		invalid |= NFS_INO_INVALID_ATTR;
1260 
1261 	if ((fattr->valid & NFS_ATTR_FATTR_ATIME) && !timespec_equal(&inode->i_atime, &fattr->atime))
1262 		invalid |= NFS_INO_INVALID_ATIME;
1263 
1264 	if (invalid != 0)
1265 		nfs_set_cache_invalid(inode, invalid);
1266 
1267 	nfsi->read_cache_jiffies = fattr->time_start;
1268 	return 0;
1269 }
1270 
1271 static int nfs_ctime_need_update(const struct inode *inode, const struct nfs_fattr *fattr)
1272 {
1273 	if (!(fattr->valid & NFS_ATTR_FATTR_CTIME))
1274 		return 0;
1275 	return timespec_compare(&fattr->ctime, &inode->i_ctime) > 0;
1276 }
1277 
1278 static atomic_long_t nfs_attr_generation_counter;
1279 
1280 static unsigned long nfs_read_attr_generation_counter(void)
1281 {
1282 	return atomic_long_read(&nfs_attr_generation_counter);
1283 }
1284 
1285 unsigned long nfs_inc_attr_generation_counter(void)
1286 {
1287 	return atomic_long_inc_return(&nfs_attr_generation_counter);
1288 }
1289 EXPORT_SYMBOL_GPL(nfs_inc_attr_generation_counter);
1290 
1291 void nfs_fattr_init(struct nfs_fattr *fattr)
1292 {
1293 	fattr->valid = 0;
1294 	fattr->time_start = jiffies;
1295 	fattr->gencount = nfs_inc_attr_generation_counter();
1296 	fattr->owner_name = NULL;
1297 	fattr->group_name = NULL;
1298 }
1299 EXPORT_SYMBOL_GPL(nfs_fattr_init);
1300 
1301 /**
1302  * nfs_fattr_set_barrier
1303  * @fattr: attributes
1304  *
1305  * Used to set a barrier after an attribute was updated. This
1306  * barrier ensures that older attributes from RPC calls that may
1307  * have raced with our update cannot clobber these new values.
1308  * Note that you are still responsible for ensuring that other
1309  * operations which change the attribute on the server do not
1310  * collide.
1311  */
1312 void nfs_fattr_set_barrier(struct nfs_fattr *fattr)
1313 {
1314 	fattr->gencount = nfs_inc_attr_generation_counter();
1315 }
1316 
1317 struct nfs_fattr *nfs_alloc_fattr(void)
1318 {
1319 	struct nfs_fattr *fattr;
1320 
1321 	fattr = kmalloc(sizeof(*fattr), GFP_NOFS);
1322 	if (fattr != NULL)
1323 		nfs_fattr_init(fattr);
1324 	return fattr;
1325 }
1326 EXPORT_SYMBOL_GPL(nfs_alloc_fattr);
1327 
1328 struct nfs_fh *nfs_alloc_fhandle(void)
1329 {
1330 	struct nfs_fh *fh;
1331 
1332 	fh = kmalloc(sizeof(struct nfs_fh), GFP_NOFS);
1333 	if (fh != NULL)
1334 		fh->size = 0;
1335 	return fh;
1336 }
1337 EXPORT_SYMBOL_GPL(nfs_alloc_fhandle);
1338 
1339 #ifdef NFS_DEBUG
1340 /*
1341  * _nfs_display_fhandle_hash - calculate the crc32 hash for the filehandle
1342  *                             in the same way that wireshark does
1343  *
1344  * @fh: file handle
1345  *
1346  * For debugging only.
1347  */
1348 u32 _nfs_display_fhandle_hash(const struct nfs_fh *fh)
1349 {
1350 	/* wireshark uses 32-bit AUTODIN crc and does a bitwise
1351 	 * not on the result */
1352 	return nfs_fhandle_hash(fh);
1353 }
1354 EXPORT_SYMBOL_GPL(_nfs_display_fhandle_hash);
1355 
1356 /*
1357  * _nfs_display_fhandle - display an NFS file handle on the console
1358  *
1359  * @fh: file handle to display
1360  * @caption: display caption
1361  *
1362  * For debugging only.
1363  */
1364 void _nfs_display_fhandle(const struct nfs_fh *fh, const char *caption)
1365 {
1366 	unsigned short i;
1367 
1368 	if (fh == NULL || fh->size == 0) {
1369 		printk(KERN_DEFAULT "%s at %p is empty\n", caption, fh);
1370 		return;
1371 	}
1372 
1373 	printk(KERN_DEFAULT "%s at %p is %u bytes, crc: 0x%08x:\n",
1374 	       caption, fh, fh->size, _nfs_display_fhandle_hash(fh));
1375 	for (i = 0; i < fh->size; i += 16) {
1376 		__be32 *pos = (__be32 *)&fh->data[i];
1377 
1378 		switch ((fh->size - i - 1) >> 2) {
1379 		case 0:
1380 			printk(KERN_DEFAULT " %08x\n",
1381 				be32_to_cpup(pos));
1382 			break;
1383 		case 1:
1384 			printk(KERN_DEFAULT " %08x %08x\n",
1385 				be32_to_cpup(pos), be32_to_cpup(pos + 1));
1386 			break;
1387 		case 2:
1388 			printk(KERN_DEFAULT " %08x %08x %08x\n",
1389 				be32_to_cpup(pos), be32_to_cpup(pos + 1),
1390 				be32_to_cpup(pos + 2));
1391 			break;
1392 		default:
1393 			printk(KERN_DEFAULT " %08x %08x %08x %08x\n",
1394 				be32_to_cpup(pos), be32_to_cpup(pos + 1),
1395 				be32_to_cpup(pos + 2), be32_to_cpup(pos + 3));
1396 		}
1397 	}
1398 }
1399 EXPORT_SYMBOL_GPL(_nfs_display_fhandle);
1400 #endif
1401 
1402 /**
1403  * nfs_inode_attrs_need_update - check if the inode attributes need updating
1404  * @inode - pointer to inode
1405  * @fattr - attributes
1406  *
1407  * Attempt to divine whether or not an RPC call reply carrying stale
1408  * attributes got scheduled after another call carrying updated ones.
1409  *
1410  * To do so, the function first assumes that a more recent ctime means
1411  * that the attributes in fattr are newer, however it also attempt to
1412  * catch the case where ctime either didn't change, or went backwards
1413  * (if someone reset the clock on the server) by looking at whether
1414  * or not this RPC call was started after the inode was last updated.
1415  * Note also the check for wraparound of 'attr_gencount'
1416  *
1417  * The function returns 'true' if it thinks the attributes in 'fattr' are
1418  * more recent than the ones cached in the inode.
1419  *
1420  */
1421 static int nfs_inode_attrs_need_update(const struct inode *inode, const struct nfs_fattr *fattr)
1422 {
1423 	const struct nfs_inode *nfsi = NFS_I(inode);
1424 
1425 	return ((long)fattr->gencount - (long)nfsi->attr_gencount) > 0 ||
1426 		nfs_ctime_need_update(inode, fattr) ||
1427 		((long)nfsi->attr_gencount - (long)nfs_read_attr_generation_counter() > 0);
1428 }
1429 
1430 /*
1431  * Don't trust the change_attribute, mtime, ctime or size if
1432  * a pnfs LAYOUTCOMMIT is outstanding
1433  */
1434 static void nfs_inode_attrs_handle_layoutcommit(struct inode *inode,
1435 		struct nfs_fattr *fattr)
1436 {
1437 	if (pnfs_layoutcommit_outstanding(inode))
1438 		fattr->valid &= ~(NFS_ATTR_FATTR_CHANGE |
1439 				NFS_ATTR_FATTR_MTIME |
1440 				NFS_ATTR_FATTR_CTIME |
1441 				NFS_ATTR_FATTR_SIZE);
1442 }
1443 
1444 static int nfs_refresh_inode_locked(struct inode *inode, struct nfs_fattr *fattr)
1445 {
1446 	int ret;
1447 
1448 	trace_nfs_refresh_inode_enter(inode);
1449 
1450 	nfs_inode_attrs_handle_layoutcommit(inode, fattr);
1451 
1452 	if (nfs_inode_attrs_need_update(inode, fattr))
1453 		ret = nfs_update_inode(inode, fattr);
1454 	else
1455 		ret = nfs_check_inode_attributes(inode, fattr);
1456 
1457 	trace_nfs_refresh_inode_exit(inode, ret);
1458 	return ret;
1459 }
1460 
1461 /**
1462  * nfs_refresh_inode - try to update the inode attribute cache
1463  * @inode - pointer to inode
1464  * @fattr - updated attributes
1465  *
1466  * Check that an RPC call that returned attributes has not overlapped with
1467  * other recent updates of the inode metadata, then decide whether it is
1468  * safe to do a full update of the inode attributes, or whether just to
1469  * call nfs_check_inode_attributes.
1470  */
1471 int nfs_refresh_inode(struct inode *inode, struct nfs_fattr *fattr)
1472 {
1473 	int status;
1474 
1475 	if ((fattr->valid & NFS_ATTR_FATTR) == 0)
1476 		return 0;
1477 	spin_lock(&inode->i_lock);
1478 	status = nfs_refresh_inode_locked(inode, fattr);
1479 	spin_unlock(&inode->i_lock);
1480 
1481 	return status;
1482 }
1483 EXPORT_SYMBOL_GPL(nfs_refresh_inode);
1484 
1485 static int nfs_post_op_update_inode_locked(struct inode *inode, struct nfs_fattr *fattr)
1486 {
1487 	unsigned long invalid = NFS_INO_INVALID_ATTR|NFS_INO_REVAL_PAGECACHE;
1488 
1489 	if (S_ISDIR(inode->i_mode))
1490 		invalid |= NFS_INO_INVALID_DATA;
1491 	nfs_set_cache_invalid(inode, invalid);
1492 	if ((fattr->valid & NFS_ATTR_FATTR) == 0)
1493 		return 0;
1494 	return nfs_refresh_inode_locked(inode, fattr);
1495 }
1496 
1497 /**
1498  * nfs_post_op_update_inode - try to update the inode attribute cache
1499  * @inode - pointer to inode
1500  * @fattr - updated attributes
1501  *
1502  * After an operation that has changed the inode metadata, mark the
1503  * attribute cache as being invalid, then try to update it.
1504  *
1505  * NB: if the server didn't return any post op attributes, this
1506  * function will force the retrieval of attributes before the next
1507  * NFS request.  Thus it should be used only for operations that
1508  * are expected to change one or more attributes, to avoid
1509  * unnecessary NFS requests and trips through nfs_update_inode().
1510  */
1511 int nfs_post_op_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1512 {
1513 	int status;
1514 
1515 	spin_lock(&inode->i_lock);
1516 	nfs_fattr_set_barrier(fattr);
1517 	status = nfs_post_op_update_inode_locked(inode, fattr);
1518 	spin_unlock(&inode->i_lock);
1519 
1520 	return status;
1521 }
1522 EXPORT_SYMBOL_GPL(nfs_post_op_update_inode);
1523 
1524 /**
1525  * nfs_post_op_update_inode_force_wcc_locked - update the inode attribute cache
1526  * @inode - pointer to inode
1527  * @fattr - updated attributes
1528  *
1529  * After an operation that has changed the inode metadata, mark the
1530  * attribute cache as being invalid, then try to update it. Fake up
1531  * weak cache consistency data, if none exist.
1532  *
1533  * This function is mainly designed to be used by the ->write_done() functions.
1534  */
1535 int nfs_post_op_update_inode_force_wcc_locked(struct inode *inode, struct nfs_fattr *fattr)
1536 {
1537 	int status;
1538 
1539 	/* Don't do a WCC update if these attributes are already stale */
1540 	if ((fattr->valid & NFS_ATTR_FATTR) == 0 ||
1541 			!nfs_inode_attrs_need_update(inode, fattr)) {
1542 		fattr->valid &= ~(NFS_ATTR_FATTR_PRECHANGE
1543 				| NFS_ATTR_FATTR_PRESIZE
1544 				| NFS_ATTR_FATTR_PREMTIME
1545 				| NFS_ATTR_FATTR_PRECTIME);
1546 		goto out_noforce;
1547 	}
1548 	if ((fattr->valid & NFS_ATTR_FATTR_CHANGE) != 0 &&
1549 			(fattr->valid & NFS_ATTR_FATTR_PRECHANGE) == 0) {
1550 		fattr->pre_change_attr = inode->i_version;
1551 		fattr->valid |= NFS_ATTR_FATTR_PRECHANGE;
1552 	}
1553 	if ((fattr->valid & NFS_ATTR_FATTR_CTIME) != 0 &&
1554 			(fattr->valid & NFS_ATTR_FATTR_PRECTIME) == 0) {
1555 		memcpy(&fattr->pre_ctime, &inode->i_ctime, sizeof(fattr->pre_ctime));
1556 		fattr->valid |= NFS_ATTR_FATTR_PRECTIME;
1557 	}
1558 	if ((fattr->valid & NFS_ATTR_FATTR_MTIME) != 0 &&
1559 			(fattr->valid & NFS_ATTR_FATTR_PREMTIME) == 0) {
1560 		memcpy(&fattr->pre_mtime, &inode->i_mtime, sizeof(fattr->pre_mtime));
1561 		fattr->valid |= NFS_ATTR_FATTR_PREMTIME;
1562 	}
1563 	if ((fattr->valid & NFS_ATTR_FATTR_SIZE) != 0 &&
1564 			(fattr->valid & NFS_ATTR_FATTR_PRESIZE) == 0) {
1565 		fattr->pre_size = i_size_read(inode);
1566 		fattr->valid |= NFS_ATTR_FATTR_PRESIZE;
1567 	}
1568 out_noforce:
1569 	status = nfs_post_op_update_inode_locked(inode, fattr);
1570 	return status;
1571 }
1572 
1573 /**
1574  * nfs_post_op_update_inode_force_wcc - try to update the inode attribute cache
1575  * @inode - pointer to inode
1576  * @fattr - updated attributes
1577  *
1578  * After an operation that has changed the inode metadata, mark the
1579  * attribute cache as being invalid, then try to update it. Fake up
1580  * weak cache consistency data, if none exist.
1581  *
1582  * This function is mainly designed to be used by the ->write_done() functions.
1583  */
1584 int nfs_post_op_update_inode_force_wcc(struct inode *inode, struct nfs_fattr *fattr)
1585 {
1586 	int status;
1587 
1588 	spin_lock(&inode->i_lock);
1589 	nfs_fattr_set_barrier(fattr);
1590 	status = nfs_post_op_update_inode_force_wcc_locked(inode, fattr);
1591 	spin_unlock(&inode->i_lock);
1592 	return status;
1593 }
1594 EXPORT_SYMBOL_GPL(nfs_post_op_update_inode_force_wcc);
1595 
1596 
1597 static inline bool nfs_fileid_valid(struct nfs_inode *nfsi,
1598 				    struct nfs_fattr *fattr)
1599 {
1600 	bool ret1 = true, ret2 = true;
1601 
1602 	if (fattr->valid & NFS_ATTR_FATTR_FILEID)
1603 		ret1 = (nfsi->fileid == fattr->fileid);
1604 	if (fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID)
1605 		ret2 = (nfsi->fileid == fattr->mounted_on_fileid);
1606 	return ret1 || ret2;
1607 }
1608 
1609 /*
1610  * Many nfs protocol calls return the new file attributes after
1611  * an operation.  Here we update the inode to reflect the state
1612  * of the server's inode.
1613  *
1614  * This is a bit tricky because we have to make sure all dirty pages
1615  * have been sent off to the server before calling invalidate_inode_pages.
1616  * To make sure no other process adds more write requests while we try
1617  * our best to flush them, we make them sleep during the attribute refresh.
1618  *
1619  * A very similar scenario holds for the dir cache.
1620  */
1621 static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1622 {
1623 	struct nfs_server *server;
1624 	struct nfs_inode *nfsi = NFS_I(inode);
1625 	loff_t cur_isize, new_isize;
1626 	unsigned long invalid = 0;
1627 	unsigned long now = jiffies;
1628 	unsigned long save_cache_validity;
1629 
1630 	dfprintk(VFS, "NFS: %s(%s/%lu fh_crc=0x%08x ct=%d info=0x%x)\n",
1631 			__func__, inode->i_sb->s_id, inode->i_ino,
1632 			nfs_display_fhandle_hash(NFS_FH(inode)),
1633 			atomic_read(&inode->i_count), fattr->valid);
1634 
1635 	if (!nfs_fileid_valid(nfsi, fattr)) {
1636 		printk(KERN_ERR "NFS: server %s error: fileid changed\n"
1637 			"fsid %s: expected fileid 0x%Lx, got 0x%Lx\n",
1638 			NFS_SERVER(inode)->nfs_client->cl_hostname,
1639 			inode->i_sb->s_id, (long long)nfsi->fileid,
1640 			(long long)fattr->fileid);
1641 		goto out_err;
1642 	}
1643 
1644 	/*
1645 	 * Make sure the inode's type hasn't changed.
1646 	 */
1647 	if ((fattr->valid & NFS_ATTR_FATTR_TYPE) && (inode->i_mode & S_IFMT) != (fattr->mode & S_IFMT)) {
1648 		/*
1649 		* Big trouble! The inode has become a different object.
1650 		*/
1651 		printk(KERN_DEBUG "NFS: %s: inode %lu mode changed, %07o to %07o\n",
1652 				__func__, inode->i_ino, inode->i_mode, fattr->mode);
1653 		goto out_err;
1654 	}
1655 
1656 	server = NFS_SERVER(inode);
1657 	/* Update the fsid? */
1658 	if (S_ISDIR(inode->i_mode) && (fattr->valid & NFS_ATTR_FATTR_FSID) &&
1659 			!nfs_fsid_equal(&server->fsid, &fattr->fsid) &&
1660 			!IS_AUTOMOUNT(inode))
1661 		server->fsid = fattr->fsid;
1662 
1663 	/*
1664 	 * Update the read time so we don't revalidate too often.
1665 	 */
1666 	nfsi->read_cache_jiffies = fattr->time_start;
1667 
1668 	save_cache_validity = nfsi->cache_validity;
1669 	nfsi->cache_validity &= ~(NFS_INO_INVALID_ATTR
1670 			| NFS_INO_INVALID_ATIME
1671 			| NFS_INO_REVAL_FORCED
1672 			| NFS_INO_REVAL_PAGECACHE);
1673 
1674 	/* Do atomic weak cache consistency updates */
1675 	invalid |= nfs_wcc_update_inode(inode, fattr);
1676 
1677 	/* More cache consistency checks */
1678 	if (fattr->valid & NFS_ATTR_FATTR_CHANGE) {
1679 		if (inode->i_version != fattr->change_attr) {
1680 			dprintk("NFS: change_attr change on server for file %s/%ld\n",
1681 					inode->i_sb->s_id, inode->i_ino);
1682 			invalid |= NFS_INO_INVALID_ATTR
1683 				| NFS_INO_INVALID_DATA
1684 				| NFS_INO_INVALID_ACCESS
1685 				| NFS_INO_INVALID_ACL
1686 				| NFS_INO_REVAL_PAGECACHE;
1687 			if (S_ISDIR(inode->i_mode))
1688 				nfs_force_lookup_revalidate(inode);
1689 			inode->i_version = fattr->change_attr;
1690 		}
1691 	} else if (server->caps & NFS_CAP_CHANGE_ATTR)
1692 		nfsi->cache_validity |= save_cache_validity;
1693 
1694 	if (fattr->valid & NFS_ATTR_FATTR_MTIME) {
1695 		memcpy(&inode->i_mtime, &fattr->mtime, sizeof(inode->i_mtime));
1696 	} else if (server->caps & NFS_CAP_MTIME)
1697 		nfsi->cache_validity |= save_cache_validity &
1698 				(NFS_INO_INVALID_ATTR
1699 				| NFS_INO_REVAL_FORCED);
1700 
1701 	if (fattr->valid & NFS_ATTR_FATTR_CTIME) {
1702 		memcpy(&inode->i_ctime, &fattr->ctime, sizeof(inode->i_ctime));
1703 	} else if (server->caps & NFS_CAP_CTIME)
1704 		nfsi->cache_validity |= save_cache_validity &
1705 				(NFS_INO_INVALID_ATTR
1706 				| NFS_INO_REVAL_FORCED);
1707 
1708 	/* Check if our cached file size is stale */
1709 	if (fattr->valid & NFS_ATTR_FATTR_SIZE) {
1710 		new_isize = nfs_size_to_loff_t(fattr->size);
1711 		cur_isize = i_size_read(inode);
1712 		if (new_isize != cur_isize) {
1713 			/* Do we perhaps have any outstanding writes, or has
1714 			 * the file grown beyond our last write? */
1715 			if ((nfsi->nrequests == 0) || new_isize > cur_isize) {
1716 				i_size_write(inode, new_isize);
1717 				invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA;
1718 				invalid &= ~NFS_INO_REVAL_PAGECACHE;
1719 			}
1720 			dprintk("NFS: isize change on server for file %s/%ld "
1721 					"(%Ld to %Ld)\n",
1722 					inode->i_sb->s_id,
1723 					inode->i_ino,
1724 					(long long)cur_isize,
1725 					(long long)new_isize);
1726 		}
1727 	} else
1728 		nfsi->cache_validity |= save_cache_validity &
1729 				(NFS_INO_INVALID_ATTR
1730 				| NFS_INO_REVAL_PAGECACHE
1731 				| NFS_INO_REVAL_FORCED);
1732 
1733 
1734 	if (fattr->valid & NFS_ATTR_FATTR_ATIME)
1735 		memcpy(&inode->i_atime, &fattr->atime, sizeof(inode->i_atime));
1736 	else if (server->caps & NFS_CAP_ATIME)
1737 		nfsi->cache_validity |= save_cache_validity &
1738 				(NFS_INO_INVALID_ATIME
1739 				| NFS_INO_REVAL_FORCED);
1740 
1741 	if (fattr->valid & NFS_ATTR_FATTR_MODE) {
1742 		if ((inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO)) {
1743 			umode_t newmode = inode->i_mode & S_IFMT;
1744 			newmode |= fattr->mode & S_IALLUGO;
1745 			inode->i_mode = newmode;
1746 			invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1747 		}
1748 	} else if (server->caps & NFS_CAP_MODE)
1749 		nfsi->cache_validity |= save_cache_validity &
1750 				(NFS_INO_INVALID_ATTR
1751 				| NFS_INO_INVALID_ACCESS
1752 				| NFS_INO_INVALID_ACL
1753 				| NFS_INO_REVAL_FORCED);
1754 
1755 	if (fattr->valid & NFS_ATTR_FATTR_OWNER) {
1756 		if (!uid_eq(inode->i_uid, fattr->uid)) {
1757 			invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1758 			inode->i_uid = fattr->uid;
1759 		}
1760 	} else if (server->caps & NFS_CAP_OWNER)
1761 		nfsi->cache_validity |= save_cache_validity &
1762 				(NFS_INO_INVALID_ATTR
1763 				| NFS_INO_INVALID_ACCESS
1764 				| NFS_INO_INVALID_ACL
1765 				| NFS_INO_REVAL_FORCED);
1766 
1767 	if (fattr->valid & NFS_ATTR_FATTR_GROUP) {
1768 		if (!gid_eq(inode->i_gid, fattr->gid)) {
1769 			invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1770 			inode->i_gid = fattr->gid;
1771 		}
1772 	} else if (server->caps & NFS_CAP_OWNER_GROUP)
1773 		nfsi->cache_validity |= save_cache_validity &
1774 				(NFS_INO_INVALID_ATTR
1775 				| NFS_INO_INVALID_ACCESS
1776 				| NFS_INO_INVALID_ACL
1777 				| NFS_INO_REVAL_FORCED);
1778 
1779 	if (fattr->valid & NFS_ATTR_FATTR_NLINK) {
1780 		if (inode->i_nlink != fattr->nlink) {
1781 			invalid |= NFS_INO_INVALID_ATTR;
1782 			if (S_ISDIR(inode->i_mode))
1783 				invalid |= NFS_INO_INVALID_DATA;
1784 			set_nlink(inode, fattr->nlink);
1785 		}
1786 	} else if (server->caps & NFS_CAP_NLINK)
1787 		nfsi->cache_validity |= save_cache_validity &
1788 				(NFS_INO_INVALID_ATTR
1789 				| NFS_INO_REVAL_FORCED);
1790 
1791 	if (fattr->valid & NFS_ATTR_FATTR_SPACE_USED) {
1792 		/*
1793 		 * report the blocks in 512byte units
1794 		 */
1795 		inode->i_blocks = nfs_calc_block_size(fattr->du.nfs3.used);
1796  	}
1797 	if (fattr->valid & NFS_ATTR_FATTR_BLOCKS_USED)
1798 		inode->i_blocks = fattr->du.nfs2.blocks;
1799 
1800 	/* Update attrtimeo value if we're out of the unstable period */
1801 	if (invalid & NFS_INO_INVALID_ATTR) {
1802 		nfs_inc_stats(inode, NFSIOS_ATTRINVALIDATE);
1803 		nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
1804 		nfsi->attrtimeo_timestamp = now;
1805 		/* Set barrier to be more recent than all outstanding updates */
1806 		nfsi->attr_gencount = nfs_inc_attr_generation_counter();
1807 	} else {
1808 		if (!time_in_range_open(now, nfsi->attrtimeo_timestamp, nfsi->attrtimeo_timestamp + nfsi->attrtimeo)) {
1809 			if ((nfsi->attrtimeo <<= 1) > NFS_MAXATTRTIMEO(inode))
1810 				nfsi->attrtimeo = NFS_MAXATTRTIMEO(inode);
1811 			nfsi->attrtimeo_timestamp = now;
1812 		}
1813 		/* Set the barrier to be more recent than this fattr */
1814 		if ((long)fattr->gencount - (long)nfsi->attr_gencount > 0)
1815 			nfsi->attr_gencount = fattr->gencount;
1816 	}
1817 	invalid &= ~NFS_INO_INVALID_ATTR;
1818 	/* Don't invalidate the data if we were to blame */
1819 	if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)
1820 				|| S_ISLNK(inode->i_mode)))
1821 		invalid &= ~NFS_INO_INVALID_DATA;
1822 	if (!NFS_PROTO(inode)->have_delegation(inode, FMODE_READ) ||
1823 			(save_cache_validity & NFS_INO_REVAL_FORCED))
1824 		nfs_set_cache_invalid(inode, invalid);
1825 
1826 	return 0;
1827  out_err:
1828 	/*
1829 	 * No need to worry about unhashing the dentry, as the
1830 	 * lookup validation will know that the inode is bad.
1831 	 * (But we fall through to invalidate the caches.)
1832 	 */
1833 	nfs_invalidate_inode(inode);
1834 	return -ESTALE;
1835 }
1836 
1837 struct inode *nfs_alloc_inode(struct super_block *sb)
1838 {
1839 	struct nfs_inode *nfsi;
1840 	nfsi = kmem_cache_alloc(nfs_inode_cachep, GFP_KERNEL);
1841 	if (!nfsi)
1842 		return NULL;
1843 	nfsi->flags = 0UL;
1844 	nfsi->cache_validity = 0UL;
1845 #if IS_ENABLED(CONFIG_NFS_V4)
1846 	nfsi->nfs4_acl = NULL;
1847 #endif /* CONFIG_NFS_V4 */
1848 	return &nfsi->vfs_inode;
1849 }
1850 EXPORT_SYMBOL_GPL(nfs_alloc_inode);
1851 
1852 static void nfs_i_callback(struct rcu_head *head)
1853 {
1854 	struct inode *inode = container_of(head, struct inode, i_rcu);
1855 	kmem_cache_free(nfs_inode_cachep, NFS_I(inode));
1856 }
1857 
1858 void nfs_destroy_inode(struct inode *inode)
1859 {
1860 	call_rcu(&inode->i_rcu, nfs_i_callback);
1861 }
1862 EXPORT_SYMBOL_GPL(nfs_destroy_inode);
1863 
1864 static inline void nfs4_init_once(struct nfs_inode *nfsi)
1865 {
1866 #if IS_ENABLED(CONFIG_NFS_V4)
1867 	INIT_LIST_HEAD(&nfsi->open_states);
1868 	nfsi->delegation = NULL;
1869 	init_rwsem(&nfsi->rwsem);
1870 	nfsi->layout = NULL;
1871 #endif
1872 }
1873 
1874 static void init_once(void *foo)
1875 {
1876 	struct nfs_inode *nfsi = (struct nfs_inode *) foo;
1877 
1878 	inode_init_once(&nfsi->vfs_inode);
1879 	INIT_LIST_HEAD(&nfsi->open_files);
1880 	INIT_LIST_HEAD(&nfsi->access_cache_entry_lru);
1881 	INIT_LIST_HEAD(&nfsi->access_cache_inode_lru);
1882 	INIT_LIST_HEAD(&nfsi->commit_info.list);
1883 	nfsi->nrequests = 0;
1884 	nfsi->commit_info.ncommit = 0;
1885 	atomic_set(&nfsi->commit_info.rpcs_out, 0);
1886 	atomic_set(&nfsi->silly_count, 1);
1887 	INIT_HLIST_HEAD(&nfsi->silly_list);
1888 	init_waitqueue_head(&nfsi->waitqueue);
1889 	nfs4_init_once(nfsi);
1890 }
1891 
1892 static int __init nfs_init_inodecache(void)
1893 {
1894 	nfs_inode_cachep = kmem_cache_create("nfs_inode_cache",
1895 					     sizeof(struct nfs_inode),
1896 					     0, (SLAB_RECLAIM_ACCOUNT|
1897 						SLAB_MEM_SPREAD),
1898 					     init_once);
1899 	if (nfs_inode_cachep == NULL)
1900 		return -ENOMEM;
1901 
1902 	return 0;
1903 }
1904 
1905 static void nfs_destroy_inodecache(void)
1906 {
1907 	/*
1908 	 * Make sure all delayed rcu free inodes are flushed before we
1909 	 * destroy cache.
1910 	 */
1911 	rcu_barrier();
1912 	kmem_cache_destroy(nfs_inode_cachep);
1913 }
1914 
1915 struct workqueue_struct *nfsiod_workqueue;
1916 EXPORT_SYMBOL_GPL(nfsiod_workqueue);
1917 
1918 /*
1919  * start up the nfsiod workqueue
1920  */
1921 static int nfsiod_start(void)
1922 {
1923 	struct workqueue_struct *wq;
1924 	dprintk("RPC:       creating workqueue nfsiod\n");
1925 	wq = alloc_workqueue("nfsiod", WQ_MEM_RECLAIM, 0);
1926 	if (wq == NULL)
1927 		return -ENOMEM;
1928 	nfsiod_workqueue = wq;
1929 	return 0;
1930 }
1931 
1932 /*
1933  * Destroy the nfsiod workqueue
1934  */
1935 static void nfsiod_stop(void)
1936 {
1937 	struct workqueue_struct *wq;
1938 
1939 	wq = nfsiod_workqueue;
1940 	if (wq == NULL)
1941 		return;
1942 	nfsiod_workqueue = NULL;
1943 	destroy_workqueue(wq);
1944 }
1945 
1946 int nfs_net_id;
1947 EXPORT_SYMBOL_GPL(nfs_net_id);
1948 
1949 static int nfs_net_init(struct net *net)
1950 {
1951 	nfs_clients_init(net);
1952 	return nfs_fs_proc_net_init(net);
1953 }
1954 
1955 static void nfs_net_exit(struct net *net)
1956 {
1957 	nfs_fs_proc_net_exit(net);
1958 	nfs_cleanup_cb_ident_idr(net);
1959 }
1960 
1961 static struct pernet_operations nfs_net_ops = {
1962 	.init = nfs_net_init,
1963 	.exit = nfs_net_exit,
1964 	.id   = &nfs_net_id,
1965 	.size = sizeof(struct nfs_net),
1966 };
1967 
1968 /*
1969  * Initialize NFS
1970  */
1971 static int __init init_nfs_fs(void)
1972 {
1973 	int err;
1974 
1975 	err = register_pernet_subsys(&nfs_net_ops);
1976 	if (err < 0)
1977 		goto out9;
1978 
1979 	err = nfs_fscache_register();
1980 	if (err < 0)
1981 		goto out8;
1982 
1983 	err = nfsiod_start();
1984 	if (err)
1985 		goto out7;
1986 
1987 	err = nfs_fs_proc_init();
1988 	if (err)
1989 		goto out6;
1990 
1991 	err = nfs_init_nfspagecache();
1992 	if (err)
1993 		goto out5;
1994 
1995 	err = nfs_init_inodecache();
1996 	if (err)
1997 		goto out4;
1998 
1999 	err = nfs_init_readpagecache();
2000 	if (err)
2001 		goto out3;
2002 
2003 	err = nfs_init_writepagecache();
2004 	if (err)
2005 		goto out2;
2006 
2007 	err = nfs_init_directcache();
2008 	if (err)
2009 		goto out1;
2010 
2011 #ifdef CONFIG_PROC_FS
2012 	rpc_proc_register(&init_net, &nfs_rpcstat);
2013 #endif
2014 	if ((err = register_nfs_fs()) != 0)
2015 		goto out0;
2016 
2017 	return 0;
2018 out0:
2019 #ifdef CONFIG_PROC_FS
2020 	rpc_proc_unregister(&init_net, "nfs");
2021 #endif
2022 	nfs_destroy_directcache();
2023 out1:
2024 	nfs_destroy_writepagecache();
2025 out2:
2026 	nfs_destroy_readpagecache();
2027 out3:
2028 	nfs_destroy_inodecache();
2029 out4:
2030 	nfs_destroy_nfspagecache();
2031 out5:
2032 	nfs_fs_proc_exit();
2033 out6:
2034 	nfsiod_stop();
2035 out7:
2036 	nfs_fscache_unregister();
2037 out8:
2038 	unregister_pernet_subsys(&nfs_net_ops);
2039 out9:
2040 	return err;
2041 }
2042 
2043 static void __exit exit_nfs_fs(void)
2044 {
2045 	nfs_destroy_directcache();
2046 	nfs_destroy_writepagecache();
2047 	nfs_destroy_readpagecache();
2048 	nfs_destroy_inodecache();
2049 	nfs_destroy_nfspagecache();
2050 	nfs_fscache_unregister();
2051 	unregister_pernet_subsys(&nfs_net_ops);
2052 #ifdef CONFIG_PROC_FS
2053 	rpc_proc_unregister(&init_net, "nfs");
2054 #endif
2055 	unregister_nfs_fs();
2056 	nfs_fs_proc_exit();
2057 	nfsiod_stop();
2058 }
2059 
2060 /* Not quite true; I just maintain it */
2061 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
2062 MODULE_LICENSE("GPL");
2063 module_param(enable_ino64, bool, 0644);
2064 
2065 module_init(init_nfs_fs)
2066 module_exit(exit_nfs_fs)
2067