xref: /openbmc/linux/fs/nfs/inode.c (revision 129d1977ed39cbb4f091a518e4a12498c04f45ba)
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 #include <linux/crc32.h>
42 
43 #include <asm/uaccess.h>
44 
45 #include "nfs4_fs.h"
46 #include "callback.h"
47 #include "delegation.h"
48 #include "iostat.h"
49 #include "internal.h"
50 #include "fscache.h"
51 #include "dns_resolve.h"
52 #include "pnfs.h"
53 #include "netns.h"
54 
55 #define NFSDBG_FACILITY		NFSDBG_VFS
56 
57 #define NFS_64_BIT_INODE_NUMBERS_ENABLED	1
58 
59 /* Default is to see 64-bit inode numbers */
60 static bool enable_ino64 = NFS_64_BIT_INODE_NUMBERS_ENABLED;
61 
62 static void nfs_invalidate_inode(struct inode *);
63 static int nfs_update_inode(struct inode *, struct nfs_fattr *);
64 
65 static struct kmem_cache * nfs_inode_cachep;
66 
67 static inline unsigned long
68 nfs_fattr_to_ino_t(struct nfs_fattr *fattr)
69 {
70 	return nfs_fileid_to_ino_t(fattr->fileid);
71 }
72 
73 /**
74  * nfs_wait_bit_killable - helper for functions that are sleeping on bit locks
75  * @word: long word containing the bit lock
76  */
77 int nfs_wait_bit_killable(void *word)
78 {
79 	if (fatal_signal_pending(current))
80 		return -ERESTARTSYS;
81 	freezable_schedule();
82 	return 0;
83 }
84 
85 /**
86  * nfs_compat_user_ino64 - returns the user-visible inode number
87  * @fileid: 64-bit fileid
88  *
89  * This function returns a 32-bit inode number if the boot parameter
90  * nfs.enable_ino64 is zero.
91  */
92 u64 nfs_compat_user_ino64(u64 fileid)
93 {
94 #ifdef CONFIG_COMPAT
95 	compat_ulong_t ino;
96 #else
97 	unsigned long ino;
98 #endif
99 
100 	if (enable_ino64)
101 		return fileid;
102 	ino = fileid;
103 	if (sizeof(ino) < sizeof(fileid))
104 		ino ^= fileid >> (sizeof(fileid)-sizeof(ino)) * 8;
105 	return ino;
106 }
107 
108 static void nfs_clear_inode(struct inode *inode)
109 {
110 	/*
111 	 * The following should never happen...
112 	 */
113 	BUG_ON(nfs_have_writebacks(inode));
114 	BUG_ON(!list_empty(&NFS_I(inode)->open_files));
115 	nfs_zap_acl_cache(inode);
116 	nfs_access_zap_cache(inode);
117 	nfs_fscache_release_inode_cookie(inode);
118 }
119 
120 void nfs_evict_inode(struct inode *inode)
121 {
122 	truncate_inode_pages(&inode->i_data, 0);
123 	clear_inode(inode);
124 	nfs_clear_inode(inode);
125 }
126 
127 /**
128  * nfs_sync_mapping - helper to flush all mmapped dirty data to disk
129  */
130 int nfs_sync_mapping(struct address_space *mapping)
131 {
132 	int ret = 0;
133 
134 	if (mapping->nrpages != 0) {
135 		unmap_mapping_range(mapping, 0, 0, 0);
136 		ret = nfs_wb_all(mapping->host);
137 	}
138 	return ret;
139 }
140 
141 /*
142  * Invalidate the local caches
143  */
144 static void nfs_zap_caches_locked(struct inode *inode)
145 {
146 	struct nfs_inode *nfsi = NFS_I(inode);
147 	int mode = inode->i_mode;
148 
149 	nfs_inc_stats(inode, NFSIOS_ATTRINVALIDATE);
150 
151 	nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
152 	nfsi->attrtimeo_timestamp = jiffies;
153 
154 	memset(NFS_COOKIEVERF(inode), 0, sizeof(NFS_COOKIEVERF(inode)));
155 	if (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))
156 		nfsi->cache_validity |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL|NFS_INO_REVAL_PAGECACHE;
157 	else
158 		nfsi->cache_validity |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL|NFS_INO_REVAL_PAGECACHE;
159 }
160 
161 void nfs_zap_caches(struct inode *inode)
162 {
163 	spin_lock(&inode->i_lock);
164 	nfs_zap_caches_locked(inode);
165 	spin_unlock(&inode->i_lock);
166 }
167 
168 void nfs_zap_mapping(struct inode *inode, struct address_space *mapping)
169 {
170 	if (mapping->nrpages != 0) {
171 		spin_lock(&inode->i_lock);
172 		NFS_I(inode)->cache_validity |= NFS_INO_INVALID_DATA;
173 		spin_unlock(&inode->i_lock);
174 	}
175 }
176 
177 void nfs_zap_acl_cache(struct inode *inode)
178 {
179 	void (*clear_acl_cache)(struct inode *);
180 
181 	clear_acl_cache = NFS_PROTO(inode)->clear_acl_cache;
182 	if (clear_acl_cache != NULL)
183 		clear_acl_cache(inode);
184 	spin_lock(&inode->i_lock);
185 	NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_ACL;
186 	spin_unlock(&inode->i_lock);
187 }
188 
189 void nfs_invalidate_atime(struct inode *inode)
190 {
191 	spin_lock(&inode->i_lock);
192 	NFS_I(inode)->cache_validity |= NFS_INO_INVALID_ATIME;
193 	spin_unlock(&inode->i_lock);
194 }
195 
196 /*
197  * Invalidate, but do not unhash, the inode.
198  * NB: must be called with inode->i_lock held!
199  */
200 static void nfs_invalidate_inode(struct inode *inode)
201 {
202 	set_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
203 	nfs_zap_caches_locked(inode);
204 }
205 
206 struct nfs_find_desc {
207 	struct nfs_fh		*fh;
208 	struct nfs_fattr	*fattr;
209 };
210 
211 /*
212  * In NFSv3 we can have 64bit inode numbers. In order to support
213  * this, and re-exported directories (also seen in NFSv2)
214  * we are forced to allow 2 different inodes to have the same
215  * i_ino.
216  */
217 static int
218 nfs_find_actor(struct inode *inode, void *opaque)
219 {
220 	struct nfs_find_desc	*desc = (struct nfs_find_desc *)opaque;
221 	struct nfs_fh		*fh = desc->fh;
222 	struct nfs_fattr	*fattr = desc->fattr;
223 
224 	if (NFS_FILEID(inode) != fattr->fileid)
225 		return 0;
226 	if (nfs_compare_fh(NFS_FH(inode), fh))
227 		return 0;
228 	if (is_bad_inode(inode) || NFS_STALE(inode))
229 		return 0;
230 	return 1;
231 }
232 
233 static int
234 nfs_init_locked(struct inode *inode, void *opaque)
235 {
236 	struct nfs_find_desc	*desc = (struct nfs_find_desc *)opaque;
237 	struct nfs_fattr	*fattr = desc->fattr;
238 
239 	set_nfs_fileid(inode, fattr->fileid);
240 	nfs_copy_fh(NFS_FH(inode), desc->fh);
241 	return 0;
242 }
243 
244 /*
245  * This is our front-end to iget that looks up inodes by file handle
246  * instead of inode number.
247  */
248 struct inode *
249 nfs_fhget(struct super_block *sb, struct nfs_fh *fh, struct nfs_fattr *fattr)
250 {
251 	struct nfs_find_desc desc = {
252 		.fh	= fh,
253 		.fattr	= fattr
254 	};
255 	struct inode *inode = ERR_PTR(-ENOENT);
256 	unsigned long hash;
257 
258 	nfs_attr_check_mountpoint(sb, fattr);
259 
260 	if (((fattr->valid & NFS_ATTR_FATTR_FILEID) == 0) &&
261 	    !nfs_attr_use_mounted_on_fileid(fattr))
262 		goto out_no_inode;
263 	if ((fattr->valid & NFS_ATTR_FATTR_TYPE) == 0)
264 		goto out_no_inode;
265 
266 	hash = nfs_fattr_to_ino_t(fattr);
267 
268 	inode = iget5_locked(sb, hash, nfs_find_actor, nfs_init_locked, &desc);
269 	if (inode == NULL) {
270 		inode = ERR_PTR(-ENOMEM);
271 		goto out_no_inode;
272 	}
273 
274 	if (inode->i_state & I_NEW) {
275 		struct nfs_inode *nfsi = NFS_I(inode);
276 		unsigned long now = jiffies;
277 
278 		/* We set i_ino for the few things that still rely on it,
279 		 * such as stat(2) */
280 		inode->i_ino = hash;
281 
282 		/* We can't support update_atime(), since the server will reset it */
283 		inode->i_flags |= S_NOATIME|S_NOCMTIME;
284 		inode->i_mode = fattr->mode;
285 		if ((fattr->valid & NFS_ATTR_FATTR_MODE) == 0
286 				&& nfs_server_capable(inode, NFS_CAP_MODE))
287 			nfsi->cache_validity |= NFS_INO_INVALID_ATTR;
288 		/* Why so? Because we want revalidate for devices/FIFOs, and
289 		 * that's precisely what we have in nfs_file_inode_operations.
290 		 */
291 		inode->i_op = NFS_SB(sb)->nfs_client->rpc_ops->file_inode_ops;
292 		if (S_ISREG(inode->i_mode)) {
293 			inode->i_fop = NFS_SB(sb)->nfs_client->rpc_ops->file_ops;
294 			inode->i_data.a_ops = &nfs_file_aops;
295 			inode->i_data.backing_dev_info = &NFS_SB(sb)->backing_dev_info;
296 		} else if (S_ISDIR(inode->i_mode)) {
297 			inode->i_op = NFS_SB(sb)->nfs_client->rpc_ops->dir_inode_ops;
298 			inode->i_fop = &nfs_dir_operations;
299 			inode->i_data.a_ops = &nfs_dir_aops;
300 			/* Deal with crossing mountpoints */
301 			if (fattr->valid & NFS_ATTR_FATTR_MOUNTPOINT ||
302 					fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL) {
303 				if (fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL)
304 					inode->i_op = &nfs_referral_inode_operations;
305 				else
306 					inode->i_op = &nfs_mountpoint_inode_operations;
307 				inode->i_fop = NULL;
308 				inode->i_flags |= S_AUTOMOUNT;
309 			}
310 		} else if (S_ISLNK(inode->i_mode))
311 			inode->i_op = &nfs_symlink_inode_operations;
312 		else
313 			init_special_inode(inode, inode->i_mode, fattr->rdev);
314 
315 		memset(&inode->i_atime, 0, sizeof(inode->i_atime));
316 		memset(&inode->i_mtime, 0, sizeof(inode->i_mtime));
317 		memset(&inode->i_ctime, 0, sizeof(inode->i_ctime));
318 		inode->i_version = 0;
319 		inode->i_size = 0;
320 		clear_nlink(inode);
321 		inode->i_uid = -2;
322 		inode->i_gid = -2;
323 		inode->i_blocks = 0;
324 		memset(nfsi->cookieverf, 0, sizeof(nfsi->cookieverf));
325 		nfsi->write_io = 0;
326 		nfsi->read_io = 0;
327 
328 		nfsi->read_cache_jiffies = fattr->time_start;
329 		nfsi->attr_gencount = fattr->gencount;
330 		if (fattr->valid & NFS_ATTR_FATTR_ATIME)
331 			inode->i_atime = fattr->atime;
332 		else if (nfs_server_capable(inode, NFS_CAP_ATIME))
333 			nfsi->cache_validity |= NFS_INO_INVALID_ATTR;
334 		if (fattr->valid & NFS_ATTR_FATTR_MTIME)
335 			inode->i_mtime = fattr->mtime;
336 		else if (nfs_server_capable(inode, NFS_CAP_MTIME))
337 			nfsi->cache_validity |= NFS_INO_INVALID_ATTR;
338 		if (fattr->valid & NFS_ATTR_FATTR_CTIME)
339 			inode->i_ctime = fattr->ctime;
340 		else if (nfs_server_capable(inode, NFS_CAP_CTIME))
341 			nfsi->cache_validity |= NFS_INO_INVALID_ATTR;
342 		if (fattr->valid & NFS_ATTR_FATTR_CHANGE)
343 			inode->i_version = fattr->change_attr;
344 		else if (nfs_server_capable(inode, NFS_CAP_CHANGE_ATTR))
345 			nfsi->cache_validity |= NFS_INO_INVALID_ATTR;
346 		if (fattr->valid & NFS_ATTR_FATTR_SIZE)
347 			inode->i_size = nfs_size_to_loff_t(fattr->size);
348 		else
349 			nfsi->cache_validity |= NFS_INO_INVALID_ATTR
350 				| NFS_INO_REVAL_PAGECACHE;
351 		if (fattr->valid & NFS_ATTR_FATTR_NLINK)
352 			set_nlink(inode, fattr->nlink);
353 		else if (nfs_server_capable(inode, NFS_CAP_NLINK))
354 			nfsi->cache_validity |= NFS_INO_INVALID_ATTR;
355 		if (fattr->valid & NFS_ATTR_FATTR_OWNER)
356 			inode->i_uid = fattr->uid;
357 		else if (nfs_server_capable(inode, NFS_CAP_OWNER))
358 			nfsi->cache_validity |= NFS_INO_INVALID_ATTR;
359 		if (fattr->valid & NFS_ATTR_FATTR_GROUP)
360 			inode->i_gid = fattr->gid;
361 		else if (nfs_server_capable(inode, NFS_CAP_OWNER_GROUP))
362 			nfsi->cache_validity |= NFS_INO_INVALID_ATTR;
363 		if (fattr->valid & NFS_ATTR_FATTR_BLOCKS_USED)
364 			inode->i_blocks = fattr->du.nfs2.blocks;
365 		if (fattr->valid & NFS_ATTR_FATTR_SPACE_USED) {
366 			/*
367 			 * report the blocks in 512byte units
368 			 */
369 			inode->i_blocks = nfs_calc_block_size(fattr->du.nfs3.used);
370 		}
371 		nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
372 		nfsi->attrtimeo_timestamp = now;
373 		nfsi->access_cache = RB_ROOT;
374 
375 		nfs_fscache_init_inode_cookie(inode);
376 
377 		unlock_new_inode(inode);
378 	} else
379 		nfs_refresh_inode(inode, fattr);
380 	dprintk("NFS: nfs_fhget(%s/%Ld fh_crc=0x%08x ct=%d)\n",
381 		inode->i_sb->s_id,
382 		(long long)NFS_FILEID(inode),
383 		nfs_display_fhandle_hash(fh),
384 		atomic_read(&inode->i_count));
385 
386 out:
387 	return inode;
388 
389 out_no_inode:
390 	dprintk("nfs_fhget: iget failed with error %ld\n", PTR_ERR(inode));
391 	goto out;
392 }
393 
394 #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)
395 
396 int
397 nfs_setattr(struct dentry *dentry, struct iattr *attr)
398 {
399 	struct inode *inode = dentry->d_inode;
400 	struct nfs_fattr *fattr;
401 	int error = -ENOMEM;
402 
403 	nfs_inc_stats(inode, NFSIOS_VFSSETATTR);
404 
405 	/* skip mode change if it's just for clearing setuid/setgid */
406 	if (attr->ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
407 		attr->ia_valid &= ~ATTR_MODE;
408 
409 	if (attr->ia_valid & ATTR_SIZE) {
410 		if (!S_ISREG(inode->i_mode) || attr->ia_size == i_size_read(inode))
411 			attr->ia_valid &= ~ATTR_SIZE;
412 	}
413 
414 	/* Optimization: if the end result is no change, don't RPC */
415 	attr->ia_valid &= NFS_VALID_ATTRS;
416 	if ((attr->ia_valid & ~(ATTR_FILE|ATTR_OPEN)) == 0)
417 		return 0;
418 
419 	/* Write all dirty data */
420 	if (S_ISREG(inode->i_mode)) {
421 		nfs_inode_dio_wait(inode);
422 		nfs_wb_all(inode);
423 	}
424 
425 	fattr = nfs_alloc_fattr();
426 	if (fattr == NULL)
427 		goto out;
428 	/*
429 	 * Return any delegations if we're going to change ACLs
430 	 */
431 	if ((attr->ia_valid & (ATTR_MODE|ATTR_UID|ATTR_GID)) != 0)
432 		NFS_PROTO(inode)->return_delegation(inode);
433 	error = NFS_PROTO(inode)->setattr(dentry, fattr, attr);
434 	if (error == 0)
435 		nfs_refresh_inode(inode, fattr);
436 	nfs_free_fattr(fattr);
437 out:
438 	return error;
439 }
440 
441 /**
442  * nfs_vmtruncate - unmap mappings "freed" by truncate() syscall
443  * @inode: inode of the file used
444  * @offset: file offset to start truncating
445  *
446  * This is a copy of the common vmtruncate, but with the locking
447  * corrected to take into account the fact that NFS requires
448  * inode->i_size to be updated under the inode->i_lock.
449  */
450 static int nfs_vmtruncate(struct inode * inode, loff_t offset)
451 {
452 	loff_t oldsize;
453 	int err;
454 
455 	err = inode_newsize_ok(inode, offset);
456 	if (err)
457 		goto out;
458 
459 	spin_lock(&inode->i_lock);
460 	oldsize = inode->i_size;
461 	i_size_write(inode, offset);
462 	spin_unlock(&inode->i_lock);
463 
464 	truncate_pagecache(inode, oldsize, offset);
465 out:
466 	return err;
467 }
468 
469 /**
470  * nfs_setattr_update_inode - Update inode metadata after a setattr call.
471  * @inode: pointer to struct inode
472  * @attr: pointer to struct iattr
473  *
474  * Note: we do this in the *proc.c in order to ensure that
475  *       it works for things like exclusive creates too.
476  */
477 void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr)
478 {
479 	if ((attr->ia_valid & (ATTR_MODE|ATTR_UID|ATTR_GID)) != 0) {
480 		spin_lock(&inode->i_lock);
481 		if ((attr->ia_valid & ATTR_MODE) != 0) {
482 			int mode = attr->ia_mode & S_IALLUGO;
483 			mode |= inode->i_mode & ~S_IALLUGO;
484 			inode->i_mode = mode;
485 		}
486 		if ((attr->ia_valid & ATTR_UID) != 0)
487 			inode->i_uid = attr->ia_uid;
488 		if ((attr->ia_valid & ATTR_GID) != 0)
489 			inode->i_gid = attr->ia_gid;
490 		NFS_I(inode)->cache_validity |= NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
491 		spin_unlock(&inode->i_lock);
492 	}
493 	if ((attr->ia_valid & ATTR_SIZE) != 0) {
494 		nfs_inc_stats(inode, NFSIOS_SETATTRTRUNC);
495 		nfs_vmtruncate(inode, attr->ia_size);
496 	}
497 }
498 
499 int nfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
500 {
501 	struct inode *inode = dentry->d_inode;
502 	int need_atime = NFS_I(inode)->cache_validity & NFS_INO_INVALID_ATIME;
503 	int err;
504 
505 	/* Flush out writes to the server in order to update c/mtime.  */
506 	if (S_ISREG(inode->i_mode)) {
507 		nfs_inode_dio_wait(inode);
508 		err = filemap_write_and_wait(inode->i_mapping);
509 		if (err)
510 			goto out;
511 	}
512 
513 	/*
514 	 * We may force a getattr if the user cares about atime.
515 	 *
516 	 * Note that we only have to check the vfsmount flags here:
517 	 *  - NFS always sets S_NOATIME by so checking it would give a
518 	 *    bogus result
519 	 *  - NFS never sets MS_NOATIME or MS_NODIRATIME so there is
520 	 *    no point in checking those.
521 	 */
522  	if ((mnt->mnt_flags & MNT_NOATIME) ||
523  	    ((mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode)))
524 		need_atime = 0;
525 
526 	if (need_atime)
527 		err = __nfs_revalidate_inode(NFS_SERVER(inode), inode);
528 	else
529 		err = nfs_revalidate_inode(NFS_SERVER(inode), inode);
530 	if (!err) {
531 		generic_fillattr(inode, stat);
532 		stat->ino = nfs_compat_user_ino64(NFS_FILEID(inode));
533 	}
534 out:
535 	return err;
536 }
537 
538 static void nfs_init_lock_context(struct nfs_lock_context *l_ctx)
539 {
540 	atomic_set(&l_ctx->count, 1);
541 	l_ctx->lockowner = current->files;
542 	l_ctx->pid = current->tgid;
543 	INIT_LIST_HEAD(&l_ctx->list);
544 }
545 
546 static struct nfs_lock_context *__nfs_find_lock_context(struct nfs_open_context *ctx)
547 {
548 	struct nfs_lock_context *pos;
549 
550 	list_for_each_entry(pos, &ctx->lock_context.list, list) {
551 		if (pos->lockowner != current->files)
552 			continue;
553 		if (pos->pid != current->tgid)
554 			continue;
555 		atomic_inc(&pos->count);
556 		return pos;
557 	}
558 	return NULL;
559 }
560 
561 struct nfs_lock_context *nfs_get_lock_context(struct nfs_open_context *ctx)
562 {
563 	struct nfs_lock_context *res, *new = NULL;
564 	struct inode *inode = ctx->dentry->d_inode;
565 
566 	spin_lock(&inode->i_lock);
567 	res = __nfs_find_lock_context(ctx);
568 	if (res == NULL) {
569 		spin_unlock(&inode->i_lock);
570 		new = kmalloc(sizeof(*new), GFP_KERNEL);
571 		if (new == NULL)
572 			return NULL;
573 		nfs_init_lock_context(new);
574 		spin_lock(&inode->i_lock);
575 		res = __nfs_find_lock_context(ctx);
576 		if (res == NULL) {
577 			list_add_tail(&new->list, &ctx->lock_context.list);
578 			new->open_context = ctx;
579 			res = new;
580 			new = NULL;
581 		}
582 	}
583 	spin_unlock(&inode->i_lock);
584 	kfree(new);
585 	return res;
586 }
587 
588 void nfs_put_lock_context(struct nfs_lock_context *l_ctx)
589 {
590 	struct nfs_open_context *ctx = l_ctx->open_context;
591 	struct inode *inode = ctx->dentry->d_inode;
592 
593 	if (!atomic_dec_and_lock(&l_ctx->count, &inode->i_lock))
594 		return;
595 	list_del(&l_ctx->list);
596 	spin_unlock(&inode->i_lock);
597 	kfree(l_ctx);
598 }
599 
600 /**
601  * nfs_close_context - Common close_context() routine NFSv2/v3
602  * @ctx: pointer to context
603  * @is_sync: is this a synchronous close
604  *
605  * always ensure that the attributes are up to date if we're mounted
606  * with close-to-open semantics
607  */
608 void nfs_close_context(struct nfs_open_context *ctx, int is_sync)
609 {
610 	struct inode *inode;
611 	struct nfs_server *server;
612 
613 	if (!(ctx->mode & FMODE_WRITE))
614 		return;
615 	if (!is_sync)
616 		return;
617 	inode = ctx->dentry->d_inode;
618 	if (!list_empty(&NFS_I(inode)->open_files))
619 		return;
620 	server = NFS_SERVER(inode);
621 	if (server->flags & NFS_MOUNT_NOCTO)
622 		return;
623 	nfs_revalidate_inode(server, inode);
624 }
625 
626 struct nfs_open_context *alloc_nfs_open_context(struct dentry *dentry, fmode_t f_mode)
627 {
628 	struct nfs_open_context *ctx;
629 	struct rpc_cred *cred = rpc_lookup_cred();
630 	if (IS_ERR(cred))
631 		return ERR_CAST(cred);
632 
633 	ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
634 	if (!ctx) {
635 		put_rpccred(cred);
636 		return ERR_PTR(-ENOMEM);
637 	}
638 	nfs_sb_active(dentry->d_sb);
639 	ctx->dentry = dget(dentry);
640 	ctx->cred = cred;
641 	ctx->state = NULL;
642 	ctx->mode = f_mode;
643 	ctx->flags = 0;
644 	ctx->error = 0;
645 	nfs_init_lock_context(&ctx->lock_context);
646 	ctx->lock_context.open_context = ctx;
647 	INIT_LIST_HEAD(&ctx->list);
648 	ctx->mdsthreshold = NULL;
649 	return ctx;
650 }
651 
652 struct nfs_open_context *get_nfs_open_context(struct nfs_open_context *ctx)
653 {
654 	if (ctx != NULL)
655 		atomic_inc(&ctx->lock_context.count);
656 	return ctx;
657 }
658 
659 static void __put_nfs_open_context(struct nfs_open_context *ctx, int is_sync)
660 {
661 	struct inode *inode = ctx->dentry->d_inode;
662 	struct super_block *sb = ctx->dentry->d_sb;
663 
664 	if (!list_empty(&ctx->list)) {
665 		if (!atomic_dec_and_lock(&ctx->lock_context.count, &inode->i_lock))
666 			return;
667 		list_del(&ctx->list);
668 		spin_unlock(&inode->i_lock);
669 	} else if (!atomic_dec_and_test(&ctx->lock_context.count))
670 		return;
671 	if (inode != NULL)
672 		NFS_PROTO(inode)->close_context(ctx, is_sync);
673 	if (ctx->cred != NULL)
674 		put_rpccred(ctx->cred);
675 	dput(ctx->dentry);
676 	nfs_sb_deactive(sb);
677 	kfree(ctx->mdsthreshold);
678 	kfree(ctx);
679 }
680 
681 void put_nfs_open_context(struct nfs_open_context *ctx)
682 {
683 	__put_nfs_open_context(ctx, 0);
684 }
685 
686 /*
687  * Ensure that mmap has a recent RPC credential for use when writing out
688  * shared pages
689  */
690 void nfs_file_set_open_context(struct file *filp, struct nfs_open_context *ctx)
691 {
692 	struct inode *inode = filp->f_path.dentry->d_inode;
693 	struct nfs_inode *nfsi = NFS_I(inode);
694 
695 	filp->private_data = get_nfs_open_context(ctx);
696 	spin_lock(&inode->i_lock);
697 	list_add(&ctx->list, &nfsi->open_files);
698 	spin_unlock(&inode->i_lock);
699 }
700 
701 /*
702  * Given an inode, search for an open context with the desired characteristics
703  */
704 struct nfs_open_context *nfs_find_open_context(struct inode *inode, struct rpc_cred *cred, fmode_t mode)
705 {
706 	struct nfs_inode *nfsi = NFS_I(inode);
707 	struct nfs_open_context *pos, *ctx = NULL;
708 
709 	spin_lock(&inode->i_lock);
710 	list_for_each_entry(pos, &nfsi->open_files, list) {
711 		if (cred != NULL && pos->cred != cred)
712 			continue;
713 		if ((pos->mode & (FMODE_READ|FMODE_WRITE)) != mode)
714 			continue;
715 		ctx = get_nfs_open_context(pos);
716 		break;
717 	}
718 	spin_unlock(&inode->i_lock);
719 	return ctx;
720 }
721 
722 static void nfs_file_clear_open_context(struct file *filp)
723 {
724 	struct inode *inode = filp->f_path.dentry->d_inode;
725 	struct nfs_open_context *ctx = nfs_file_open_context(filp);
726 
727 	if (ctx) {
728 		filp->private_data = NULL;
729 		spin_lock(&inode->i_lock);
730 		list_move_tail(&ctx->list, &NFS_I(inode)->open_files);
731 		spin_unlock(&inode->i_lock);
732 		__put_nfs_open_context(ctx, filp->f_flags & O_DIRECT ? 0 : 1);
733 	}
734 }
735 
736 /*
737  * These allocate and release file read/write context information.
738  */
739 int nfs_open(struct inode *inode, struct file *filp)
740 {
741 	struct nfs_open_context *ctx;
742 
743 	ctx = alloc_nfs_open_context(filp->f_path.dentry, filp->f_mode);
744 	if (IS_ERR(ctx))
745 		return PTR_ERR(ctx);
746 	nfs_file_set_open_context(filp, ctx);
747 	put_nfs_open_context(ctx);
748 	nfs_fscache_set_inode_cookie(inode, filp);
749 	return 0;
750 }
751 
752 int nfs_release(struct inode *inode, struct file *filp)
753 {
754 	nfs_file_clear_open_context(filp);
755 	return 0;
756 }
757 
758 /*
759  * This function is called whenever some part of NFS notices that
760  * the cached attributes have to be refreshed.
761  */
762 int
763 __nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
764 {
765 	int		 status = -ESTALE;
766 	struct nfs_fattr *fattr = NULL;
767 	struct nfs_inode *nfsi = NFS_I(inode);
768 
769 	dfprintk(PAGECACHE, "NFS: revalidating (%s/%Ld)\n",
770 		inode->i_sb->s_id, (long long)NFS_FILEID(inode));
771 
772 	if (is_bad_inode(inode))
773 		goto out;
774 	if (NFS_STALE(inode))
775 		goto out;
776 
777 	status = -ENOMEM;
778 	fattr = nfs_alloc_fattr();
779 	if (fattr == NULL)
780 		goto out;
781 
782 	nfs_inc_stats(inode, NFSIOS_INODEREVALIDATE);
783 	status = NFS_PROTO(inode)->getattr(server, NFS_FH(inode), fattr);
784 	if (status != 0) {
785 		dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Ld) getattr failed, error=%d\n",
786 			 inode->i_sb->s_id,
787 			 (long long)NFS_FILEID(inode), status);
788 		if (status == -ESTALE) {
789 			nfs_zap_caches(inode);
790 			if (!S_ISDIR(inode->i_mode))
791 				set_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
792 		}
793 		goto out;
794 	}
795 
796 	status = nfs_refresh_inode(inode, fattr);
797 	if (status) {
798 		dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Ld) refresh failed, error=%d\n",
799 			 inode->i_sb->s_id,
800 			 (long long)NFS_FILEID(inode), status);
801 		goto out;
802 	}
803 
804 	if (nfsi->cache_validity & NFS_INO_INVALID_ACL)
805 		nfs_zap_acl_cache(inode);
806 
807 	dfprintk(PAGECACHE, "NFS: (%s/%Ld) revalidation complete\n",
808 		inode->i_sb->s_id,
809 		(long long)NFS_FILEID(inode));
810 
811  out:
812 	nfs_free_fattr(fattr);
813 	return status;
814 }
815 
816 int nfs_attribute_timeout(struct inode *inode)
817 {
818 	struct nfs_inode *nfsi = NFS_I(inode);
819 
820 	return !time_in_range_open(jiffies, nfsi->read_cache_jiffies, nfsi->read_cache_jiffies + nfsi->attrtimeo);
821 }
822 
823 static int nfs_attribute_cache_expired(struct inode *inode)
824 {
825 	if (nfs_have_delegated_attributes(inode))
826 		return 0;
827 	return nfs_attribute_timeout(inode);
828 }
829 
830 /**
831  * nfs_revalidate_inode - Revalidate the inode attributes
832  * @server - pointer to nfs_server struct
833  * @inode - pointer to inode struct
834  *
835  * Updates inode attribute information by retrieving the data from the server.
836  */
837 int nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
838 {
839 	if (!(NFS_I(inode)->cache_validity & NFS_INO_INVALID_ATTR)
840 			&& !nfs_attribute_cache_expired(inode))
841 		return NFS_STALE(inode) ? -ESTALE : 0;
842 	return __nfs_revalidate_inode(server, inode);
843 }
844 
845 static int nfs_invalidate_mapping(struct inode *inode, struct address_space *mapping)
846 {
847 	struct nfs_inode *nfsi = NFS_I(inode);
848 
849 	if (mapping->nrpages != 0) {
850 		int ret = invalidate_inode_pages2(mapping);
851 		if (ret < 0)
852 			return ret;
853 	}
854 	spin_lock(&inode->i_lock);
855 	nfsi->cache_validity &= ~NFS_INO_INVALID_DATA;
856 	if (S_ISDIR(inode->i_mode))
857 		memset(nfsi->cookieverf, 0, sizeof(nfsi->cookieverf));
858 	spin_unlock(&inode->i_lock);
859 	nfs_inc_stats(inode, NFSIOS_DATAINVALIDATE);
860 	nfs_fscache_reset_inode_cookie(inode);
861 	dfprintk(PAGECACHE, "NFS: (%s/%Ld) data cache invalidated\n",
862 			inode->i_sb->s_id, (long long)NFS_FILEID(inode));
863 	return 0;
864 }
865 
866 static bool nfs_mapping_need_revalidate_inode(struct inode *inode)
867 {
868 	if (nfs_have_delegated_attributes(inode))
869 		return false;
870 	return (NFS_I(inode)->cache_validity & NFS_INO_REVAL_PAGECACHE)
871 		|| nfs_attribute_timeout(inode)
872 		|| NFS_STALE(inode);
873 }
874 
875 /**
876  * nfs_revalidate_mapping - Revalidate the pagecache
877  * @inode - pointer to host inode
878  * @mapping - pointer to mapping
879  */
880 int nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping)
881 {
882 	struct nfs_inode *nfsi = NFS_I(inode);
883 	int ret = 0;
884 
885 	if (nfs_mapping_need_revalidate_inode(inode)) {
886 		ret = __nfs_revalidate_inode(NFS_SERVER(inode), inode);
887 		if (ret < 0)
888 			goto out;
889 	}
890 	if (nfsi->cache_validity & NFS_INO_INVALID_DATA)
891 		ret = nfs_invalidate_mapping(inode, mapping);
892 out:
893 	return ret;
894 }
895 
896 static unsigned long nfs_wcc_update_inode(struct inode *inode, struct nfs_fattr *fattr)
897 {
898 	struct nfs_inode *nfsi = NFS_I(inode);
899 	unsigned long ret = 0;
900 
901 	if ((fattr->valid & NFS_ATTR_FATTR_PRECHANGE)
902 			&& (fattr->valid & NFS_ATTR_FATTR_CHANGE)
903 			&& inode->i_version == fattr->pre_change_attr) {
904 		inode->i_version = fattr->change_attr;
905 		if (S_ISDIR(inode->i_mode))
906 			nfsi->cache_validity |= NFS_INO_INVALID_DATA;
907 		ret |= NFS_INO_INVALID_ATTR;
908 	}
909 	/* If we have atomic WCC data, we may update some attributes */
910 	if ((fattr->valid & NFS_ATTR_FATTR_PRECTIME)
911 			&& (fattr->valid & NFS_ATTR_FATTR_CTIME)
912 			&& timespec_equal(&inode->i_ctime, &fattr->pre_ctime)) {
913 		memcpy(&inode->i_ctime, &fattr->ctime, sizeof(inode->i_ctime));
914 		ret |= NFS_INO_INVALID_ATTR;
915 	}
916 
917 	if ((fattr->valid & NFS_ATTR_FATTR_PREMTIME)
918 			&& (fattr->valid & NFS_ATTR_FATTR_MTIME)
919 			&& timespec_equal(&inode->i_mtime, &fattr->pre_mtime)) {
920 		memcpy(&inode->i_mtime, &fattr->mtime, sizeof(inode->i_mtime));
921 		if (S_ISDIR(inode->i_mode))
922 			nfsi->cache_validity |= NFS_INO_INVALID_DATA;
923 		ret |= NFS_INO_INVALID_ATTR;
924 	}
925 	if ((fattr->valid & NFS_ATTR_FATTR_PRESIZE)
926 			&& (fattr->valid & NFS_ATTR_FATTR_SIZE)
927 			&& i_size_read(inode) == nfs_size_to_loff_t(fattr->pre_size)
928 			&& nfsi->npages == 0) {
929 		i_size_write(inode, nfs_size_to_loff_t(fattr->size));
930 		ret |= NFS_INO_INVALID_ATTR;
931 	}
932 	return ret;
933 }
934 
935 /**
936  * nfs_check_inode_attributes - verify consistency of the inode attribute cache
937  * @inode - pointer to inode
938  * @fattr - updated attributes
939  *
940  * Verifies the attribute cache. If we have just changed the attributes,
941  * so that fattr carries weak cache consistency data, then it may
942  * also update the ctime/mtime/change_attribute.
943  */
944 static int nfs_check_inode_attributes(struct inode *inode, struct nfs_fattr *fattr)
945 {
946 	struct nfs_inode *nfsi = NFS_I(inode);
947 	loff_t cur_size, new_isize;
948 	unsigned long invalid = 0;
949 
950 
951 	if (nfs_have_delegated_attributes(inode))
952 		return 0;
953 	/* Has the inode gone and changed behind our back? */
954 	if ((fattr->valid & NFS_ATTR_FATTR_FILEID) && nfsi->fileid != fattr->fileid)
955 		return -EIO;
956 	if ((fattr->valid & NFS_ATTR_FATTR_TYPE) && (inode->i_mode & S_IFMT) != (fattr->mode & S_IFMT))
957 		return -EIO;
958 
959 	if ((fattr->valid & NFS_ATTR_FATTR_CHANGE) != 0 &&
960 			inode->i_version != fattr->change_attr)
961 		invalid |= NFS_INO_INVALID_ATTR|NFS_INO_REVAL_PAGECACHE;
962 
963 	/* Verify a few of the more important attributes */
964 	if ((fattr->valid & NFS_ATTR_FATTR_MTIME) && !timespec_equal(&inode->i_mtime, &fattr->mtime))
965 		invalid |= NFS_INO_INVALID_ATTR;
966 
967 	if (fattr->valid & NFS_ATTR_FATTR_SIZE) {
968 		cur_size = i_size_read(inode);
969 		new_isize = nfs_size_to_loff_t(fattr->size);
970 		if (cur_size != new_isize && nfsi->npages == 0)
971 			invalid |= NFS_INO_INVALID_ATTR|NFS_INO_REVAL_PAGECACHE;
972 	}
973 
974 	/* Have any file permissions changed? */
975 	if ((fattr->valid & NFS_ATTR_FATTR_MODE) && (inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO))
976 		invalid |= NFS_INO_INVALID_ATTR | NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL;
977 	if ((fattr->valid & NFS_ATTR_FATTR_OWNER) && inode->i_uid != fattr->uid)
978 		invalid |= NFS_INO_INVALID_ATTR | NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL;
979 	if ((fattr->valid & NFS_ATTR_FATTR_GROUP) && inode->i_gid != fattr->gid)
980 		invalid |= NFS_INO_INVALID_ATTR | NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL;
981 
982 	/* Has the link count changed? */
983 	if ((fattr->valid & NFS_ATTR_FATTR_NLINK) && inode->i_nlink != fattr->nlink)
984 		invalid |= NFS_INO_INVALID_ATTR;
985 
986 	if ((fattr->valid & NFS_ATTR_FATTR_ATIME) && !timespec_equal(&inode->i_atime, &fattr->atime))
987 		invalid |= NFS_INO_INVALID_ATIME;
988 
989 	if (invalid != 0)
990 		nfsi->cache_validity |= invalid;
991 
992 	nfsi->read_cache_jiffies = fattr->time_start;
993 	return 0;
994 }
995 
996 static int nfs_ctime_need_update(const struct inode *inode, const struct nfs_fattr *fattr)
997 {
998 	if (!(fattr->valid & NFS_ATTR_FATTR_CTIME))
999 		return 0;
1000 	return timespec_compare(&fattr->ctime, &inode->i_ctime) > 0;
1001 }
1002 
1003 static int nfs_size_need_update(const struct inode *inode, const struct nfs_fattr *fattr)
1004 {
1005 	if (!(fattr->valid & NFS_ATTR_FATTR_SIZE))
1006 		return 0;
1007 	return nfs_size_to_loff_t(fattr->size) > i_size_read(inode);
1008 }
1009 
1010 static atomic_long_t nfs_attr_generation_counter;
1011 
1012 static unsigned long nfs_read_attr_generation_counter(void)
1013 {
1014 	return atomic_long_read(&nfs_attr_generation_counter);
1015 }
1016 
1017 unsigned long nfs_inc_attr_generation_counter(void)
1018 {
1019 	return atomic_long_inc_return(&nfs_attr_generation_counter);
1020 }
1021 
1022 void nfs_fattr_init(struct nfs_fattr *fattr)
1023 {
1024 	fattr->valid = 0;
1025 	fattr->time_start = jiffies;
1026 	fattr->gencount = nfs_inc_attr_generation_counter();
1027 	fattr->owner_name = NULL;
1028 	fattr->group_name = NULL;
1029 }
1030 
1031 struct nfs_fattr *nfs_alloc_fattr(void)
1032 {
1033 	struct nfs_fattr *fattr;
1034 
1035 	fattr = kmalloc(sizeof(*fattr), GFP_NOFS);
1036 	if (fattr != NULL)
1037 		nfs_fattr_init(fattr);
1038 	return fattr;
1039 }
1040 
1041 struct nfs_fh *nfs_alloc_fhandle(void)
1042 {
1043 	struct nfs_fh *fh;
1044 
1045 	fh = kmalloc(sizeof(struct nfs_fh), GFP_NOFS);
1046 	if (fh != NULL)
1047 		fh->size = 0;
1048 	return fh;
1049 }
1050 
1051 #ifdef NFS_DEBUG
1052 /*
1053  * _nfs_display_fhandle_hash - calculate the crc32 hash for the filehandle
1054  *                             in the same way that wireshark does
1055  *
1056  * @fh: file handle
1057  *
1058  * For debugging only.
1059  */
1060 u32 _nfs_display_fhandle_hash(const struct nfs_fh *fh)
1061 {
1062 	/* wireshark uses 32-bit AUTODIN crc and does a bitwise
1063 	 * not on the result */
1064 	return ~crc32(0xFFFFFFFF, &fh->data[0], fh->size);
1065 }
1066 
1067 /*
1068  * _nfs_display_fhandle - display an NFS file handle on the console
1069  *
1070  * @fh: file handle to display
1071  * @caption: display caption
1072  *
1073  * For debugging only.
1074  */
1075 void _nfs_display_fhandle(const struct nfs_fh *fh, const char *caption)
1076 {
1077 	unsigned short i;
1078 
1079 	if (fh == NULL || fh->size == 0) {
1080 		printk(KERN_DEFAULT "%s at %p is empty\n", caption, fh);
1081 		return;
1082 	}
1083 
1084 	printk(KERN_DEFAULT "%s at %p is %u bytes, crc: 0x%08x:\n",
1085 	       caption, fh, fh->size, _nfs_display_fhandle_hash(fh));
1086 	for (i = 0; i < fh->size; i += 16) {
1087 		__be32 *pos = (__be32 *)&fh->data[i];
1088 
1089 		switch ((fh->size - i - 1) >> 2) {
1090 		case 0:
1091 			printk(KERN_DEFAULT " %08x\n",
1092 				be32_to_cpup(pos));
1093 			break;
1094 		case 1:
1095 			printk(KERN_DEFAULT " %08x %08x\n",
1096 				be32_to_cpup(pos), be32_to_cpup(pos + 1));
1097 			break;
1098 		case 2:
1099 			printk(KERN_DEFAULT " %08x %08x %08x\n",
1100 				be32_to_cpup(pos), be32_to_cpup(pos + 1),
1101 				be32_to_cpup(pos + 2));
1102 			break;
1103 		default:
1104 			printk(KERN_DEFAULT " %08x %08x %08x %08x\n",
1105 				be32_to_cpup(pos), be32_to_cpup(pos + 1),
1106 				be32_to_cpup(pos + 2), be32_to_cpup(pos + 3));
1107 		}
1108 	}
1109 }
1110 #endif
1111 
1112 /**
1113  * nfs_inode_attrs_need_update - check if the inode attributes need updating
1114  * @inode - pointer to inode
1115  * @fattr - attributes
1116  *
1117  * Attempt to divine whether or not an RPC call reply carrying stale
1118  * attributes got scheduled after another call carrying updated ones.
1119  *
1120  * To do so, the function first assumes that a more recent ctime means
1121  * that the attributes in fattr are newer, however it also attempt to
1122  * catch the case where ctime either didn't change, or went backwards
1123  * (if someone reset the clock on the server) by looking at whether
1124  * or not this RPC call was started after the inode was last updated.
1125  * Note also the check for wraparound of 'attr_gencount'
1126  *
1127  * The function returns 'true' if it thinks the attributes in 'fattr' are
1128  * more recent than the ones cached in the inode.
1129  *
1130  */
1131 static int nfs_inode_attrs_need_update(const struct inode *inode, const struct nfs_fattr *fattr)
1132 {
1133 	const struct nfs_inode *nfsi = NFS_I(inode);
1134 
1135 	return ((long)fattr->gencount - (long)nfsi->attr_gencount) > 0 ||
1136 		nfs_ctime_need_update(inode, fattr) ||
1137 		nfs_size_need_update(inode, fattr) ||
1138 		((long)nfsi->attr_gencount - (long)nfs_read_attr_generation_counter() > 0);
1139 }
1140 
1141 static int nfs_refresh_inode_locked(struct inode *inode, struct nfs_fattr *fattr)
1142 {
1143 	if (nfs_inode_attrs_need_update(inode, fattr))
1144 		return nfs_update_inode(inode, fattr);
1145 	return nfs_check_inode_attributes(inode, fattr);
1146 }
1147 
1148 /**
1149  * nfs_refresh_inode - try to update the inode attribute cache
1150  * @inode - pointer to inode
1151  * @fattr - updated attributes
1152  *
1153  * Check that an RPC call that returned attributes has not overlapped with
1154  * other recent updates of the inode metadata, then decide whether it is
1155  * safe to do a full update of the inode attributes, or whether just to
1156  * call nfs_check_inode_attributes.
1157  */
1158 int nfs_refresh_inode(struct inode *inode, struct nfs_fattr *fattr)
1159 {
1160 	int status;
1161 
1162 	if ((fattr->valid & NFS_ATTR_FATTR) == 0)
1163 		return 0;
1164 	spin_lock(&inode->i_lock);
1165 	status = nfs_refresh_inode_locked(inode, fattr);
1166 	spin_unlock(&inode->i_lock);
1167 
1168 	return status;
1169 }
1170 
1171 static int nfs_post_op_update_inode_locked(struct inode *inode, struct nfs_fattr *fattr)
1172 {
1173 	struct nfs_inode *nfsi = NFS_I(inode);
1174 
1175 	nfsi->cache_validity |= NFS_INO_INVALID_ATTR|NFS_INO_REVAL_PAGECACHE;
1176 	if (S_ISDIR(inode->i_mode))
1177 		nfsi->cache_validity |= NFS_INO_INVALID_DATA;
1178 	if ((fattr->valid & NFS_ATTR_FATTR) == 0)
1179 		return 0;
1180 	return nfs_refresh_inode_locked(inode, fattr);
1181 }
1182 
1183 /**
1184  * nfs_post_op_update_inode - try to update the inode attribute cache
1185  * @inode - pointer to inode
1186  * @fattr - updated attributes
1187  *
1188  * After an operation that has changed the inode metadata, mark the
1189  * attribute cache as being invalid, then try to update it.
1190  *
1191  * NB: if the server didn't return any post op attributes, this
1192  * function will force the retrieval of attributes before the next
1193  * NFS request.  Thus it should be used only for operations that
1194  * are expected to change one or more attributes, to avoid
1195  * unnecessary NFS requests and trips through nfs_update_inode().
1196  */
1197 int nfs_post_op_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1198 {
1199 	int status;
1200 
1201 	spin_lock(&inode->i_lock);
1202 	status = nfs_post_op_update_inode_locked(inode, fattr);
1203 	spin_unlock(&inode->i_lock);
1204 	return status;
1205 }
1206 
1207 /**
1208  * nfs_post_op_update_inode_force_wcc - try to update the inode attribute cache
1209  * @inode - pointer to inode
1210  * @fattr - updated attributes
1211  *
1212  * After an operation that has changed the inode metadata, mark the
1213  * attribute cache as being invalid, then try to update it. Fake up
1214  * weak cache consistency data, if none exist.
1215  *
1216  * This function is mainly designed to be used by the ->write_done() functions.
1217  */
1218 int nfs_post_op_update_inode_force_wcc(struct inode *inode, struct nfs_fattr *fattr)
1219 {
1220 	int status;
1221 
1222 	spin_lock(&inode->i_lock);
1223 	/* Don't do a WCC update if these attributes are already stale */
1224 	if ((fattr->valid & NFS_ATTR_FATTR) == 0 ||
1225 			!nfs_inode_attrs_need_update(inode, fattr)) {
1226 		fattr->valid &= ~(NFS_ATTR_FATTR_PRECHANGE
1227 				| NFS_ATTR_FATTR_PRESIZE
1228 				| NFS_ATTR_FATTR_PREMTIME
1229 				| NFS_ATTR_FATTR_PRECTIME);
1230 		goto out_noforce;
1231 	}
1232 	if ((fattr->valid & NFS_ATTR_FATTR_CHANGE) != 0 &&
1233 			(fattr->valid & NFS_ATTR_FATTR_PRECHANGE) == 0) {
1234 		fattr->pre_change_attr = inode->i_version;
1235 		fattr->valid |= NFS_ATTR_FATTR_PRECHANGE;
1236 	}
1237 	if ((fattr->valid & NFS_ATTR_FATTR_CTIME) != 0 &&
1238 			(fattr->valid & NFS_ATTR_FATTR_PRECTIME) == 0) {
1239 		memcpy(&fattr->pre_ctime, &inode->i_ctime, sizeof(fattr->pre_ctime));
1240 		fattr->valid |= NFS_ATTR_FATTR_PRECTIME;
1241 	}
1242 	if ((fattr->valid & NFS_ATTR_FATTR_MTIME) != 0 &&
1243 			(fattr->valid & NFS_ATTR_FATTR_PREMTIME) == 0) {
1244 		memcpy(&fattr->pre_mtime, &inode->i_mtime, sizeof(fattr->pre_mtime));
1245 		fattr->valid |= NFS_ATTR_FATTR_PREMTIME;
1246 	}
1247 	if ((fattr->valid & NFS_ATTR_FATTR_SIZE) != 0 &&
1248 			(fattr->valid & NFS_ATTR_FATTR_PRESIZE) == 0) {
1249 		fattr->pre_size = i_size_read(inode);
1250 		fattr->valid |= NFS_ATTR_FATTR_PRESIZE;
1251 	}
1252 out_noforce:
1253 	status = nfs_post_op_update_inode_locked(inode, fattr);
1254 	spin_unlock(&inode->i_lock);
1255 	return status;
1256 }
1257 
1258 /*
1259  * Many nfs protocol calls return the new file attributes after
1260  * an operation.  Here we update the inode to reflect the state
1261  * of the server's inode.
1262  *
1263  * This is a bit tricky because we have to make sure all dirty pages
1264  * have been sent off to the server before calling invalidate_inode_pages.
1265  * To make sure no other process adds more write requests while we try
1266  * our best to flush them, we make them sleep during the attribute refresh.
1267  *
1268  * A very similar scenario holds for the dir cache.
1269  */
1270 static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1271 {
1272 	struct nfs_server *server;
1273 	struct nfs_inode *nfsi = NFS_I(inode);
1274 	loff_t cur_isize, new_isize;
1275 	unsigned long invalid = 0;
1276 	unsigned long now = jiffies;
1277 	unsigned long save_cache_validity;
1278 
1279 	dfprintk(VFS, "NFS: %s(%s/%ld fh_crc=0x%08x ct=%d info=0x%x)\n",
1280 			__func__, inode->i_sb->s_id, inode->i_ino,
1281 			nfs_display_fhandle_hash(NFS_FH(inode)),
1282 			atomic_read(&inode->i_count), fattr->valid);
1283 
1284 	if ((fattr->valid & NFS_ATTR_FATTR_FILEID) && nfsi->fileid != fattr->fileid) {
1285 		printk(KERN_ERR "NFS: server %s error: fileid changed\n"
1286 			"fsid %s: expected fileid 0x%Lx, got 0x%Lx\n",
1287 			NFS_SERVER(inode)->nfs_client->cl_hostname,
1288 			inode->i_sb->s_id, (long long)nfsi->fileid,
1289 			(long long)fattr->fileid);
1290 		goto out_err;
1291 	}
1292 
1293 	/*
1294 	 * Make sure the inode's type hasn't changed.
1295 	 */
1296 	if ((fattr->valid & NFS_ATTR_FATTR_TYPE) && (inode->i_mode & S_IFMT) != (fattr->mode & S_IFMT)) {
1297 		/*
1298 		* Big trouble! The inode has become a different object.
1299 		*/
1300 		printk(KERN_DEBUG "NFS: %s: inode %ld mode changed, %07o to %07o\n",
1301 				__func__, inode->i_ino, inode->i_mode, fattr->mode);
1302 		goto out_err;
1303 	}
1304 
1305 	server = NFS_SERVER(inode);
1306 	/* Update the fsid? */
1307 	if (S_ISDIR(inode->i_mode) && (fattr->valid & NFS_ATTR_FATTR_FSID) &&
1308 			!nfs_fsid_equal(&server->fsid, &fattr->fsid) &&
1309 			!IS_AUTOMOUNT(inode))
1310 		server->fsid = fattr->fsid;
1311 
1312 	/*
1313 	 * Update the read time so we don't revalidate too often.
1314 	 */
1315 	nfsi->read_cache_jiffies = fattr->time_start;
1316 
1317 	save_cache_validity = nfsi->cache_validity;
1318 	nfsi->cache_validity &= ~(NFS_INO_INVALID_ATTR
1319 			| NFS_INO_INVALID_ATIME
1320 			| NFS_INO_REVAL_FORCED
1321 			| NFS_INO_REVAL_PAGECACHE);
1322 
1323 	/* Do atomic weak cache consistency updates */
1324 	invalid |= nfs_wcc_update_inode(inode, fattr);
1325 
1326 	/* More cache consistency checks */
1327 	if (fattr->valid & NFS_ATTR_FATTR_CHANGE) {
1328 		if (inode->i_version != fattr->change_attr) {
1329 			dprintk("NFS: change_attr change on server for file %s/%ld\n",
1330 					inode->i_sb->s_id, inode->i_ino);
1331 			invalid |= NFS_INO_INVALID_ATTR
1332 				| NFS_INO_INVALID_DATA
1333 				| NFS_INO_INVALID_ACCESS
1334 				| NFS_INO_INVALID_ACL
1335 				| NFS_INO_REVAL_PAGECACHE;
1336 			if (S_ISDIR(inode->i_mode))
1337 				nfs_force_lookup_revalidate(inode);
1338 			inode->i_version = fattr->change_attr;
1339 		}
1340 	} else if (server->caps & NFS_CAP_CHANGE_ATTR)
1341 		invalid |= save_cache_validity;
1342 
1343 	if (fattr->valid & NFS_ATTR_FATTR_MTIME) {
1344 		memcpy(&inode->i_mtime, &fattr->mtime, sizeof(inode->i_mtime));
1345 	} else if (server->caps & NFS_CAP_MTIME)
1346 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1347 				| NFS_INO_REVAL_FORCED);
1348 
1349 	if (fattr->valid & NFS_ATTR_FATTR_CTIME) {
1350 		memcpy(&inode->i_ctime, &fattr->ctime, sizeof(inode->i_ctime));
1351 	} else if (server->caps & NFS_CAP_CTIME)
1352 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1353 				| NFS_INO_REVAL_FORCED);
1354 
1355 	/* Check if our cached file size is stale */
1356 	if (fattr->valid & NFS_ATTR_FATTR_SIZE) {
1357 		new_isize = nfs_size_to_loff_t(fattr->size);
1358 		cur_isize = i_size_read(inode);
1359 		if (new_isize != cur_isize) {
1360 			/* Do we perhaps have any outstanding writes, or has
1361 			 * the file grown beyond our last write? */
1362 			if ((nfsi->npages == 0 && !test_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags)) ||
1363 			     new_isize > cur_isize) {
1364 				i_size_write(inode, new_isize);
1365 				invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA;
1366 			}
1367 			dprintk("NFS: isize change on server for file %s/%ld "
1368 					"(%Ld to %Ld)\n",
1369 					inode->i_sb->s_id,
1370 					inode->i_ino,
1371 					(long long)cur_isize,
1372 					(long long)new_isize);
1373 		}
1374 	} else
1375 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1376 				| NFS_INO_REVAL_PAGECACHE
1377 				| NFS_INO_REVAL_FORCED);
1378 
1379 
1380 	if (fattr->valid & NFS_ATTR_FATTR_ATIME)
1381 		memcpy(&inode->i_atime, &fattr->atime, sizeof(inode->i_atime));
1382 	else if (server->caps & NFS_CAP_ATIME)
1383 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATIME
1384 				| NFS_INO_REVAL_FORCED);
1385 
1386 	if (fattr->valid & NFS_ATTR_FATTR_MODE) {
1387 		if ((inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO)) {
1388 			umode_t newmode = inode->i_mode & S_IFMT;
1389 			newmode |= fattr->mode & S_IALLUGO;
1390 			inode->i_mode = newmode;
1391 			invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1392 		}
1393 	} else if (server->caps & NFS_CAP_MODE)
1394 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1395 				| NFS_INO_INVALID_ACCESS
1396 				| NFS_INO_INVALID_ACL
1397 				| NFS_INO_REVAL_FORCED);
1398 
1399 	if (fattr->valid & NFS_ATTR_FATTR_OWNER) {
1400 		if (inode->i_uid != fattr->uid) {
1401 			invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1402 			inode->i_uid = fattr->uid;
1403 		}
1404 	} else if (server->caps & NFS_CAP_OWNER)
1405 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1406 				| NFS_INO_INVALID_ACCESS
1407 				| NFS_INO_INVALID_ACL
1408 				| NFS_INO_REVAL_FORCED);
1409 
1410 	if (fattr->valid & NFS_ATTR_FATTR_GROUP) {
1411 		if (inode->i_gid != fattr->gid) {
1412 			invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1413 			inode->i_gid = fattr->gid;
1414 		}
1415 	} else if (server->caps & NFS_CAP_OWNER_GROUP)
1416 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1417 				| NFS_INO_INVALID_ACCESS
1418 				| NFS_INO_INVALID_ACL
1419 				| NFS_INO_REVAL_FORCED);
1420 
1421 	if (fattr->valid & NFS_ATTR_FATTR_NLINK) {
1422 		if (inode->i_nlink != fattr->nlink) {
1423 			invalid |= NFS_INO_INVALID_ATTR;
1424 			if (S_ISDIR(inode->i_mode))
1425 				invalid |= NFS_INO_INVALID_DATA;
1426 			set_nlink(inode, fattr->nlink);
1427 		}
1428 	} else if (server->caps & NFS_CAP_NLINK)
1429 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1430 				| NFS_INO_REVAL_FORCED);
1431 
1432 	if (fattr->valid & NFS_ATTR_FATTR_SPACE_USED) {
1433 		/*
1434 		 * report the blocks in 512byte units
1435 		 */
1436 		inode->i_blocks = nfs_calc_block_size(fattr->du.nfs3.used);
1437  	}
1438 	if (fattr->valid & NFS_ATTR_FATTR_BLOCKS_USED)
1439 		inode->i_blocks = fattr->du.nfs2.blocks;
1440 
1441 	/* Update attrtimeo value if we're out of the unstable period */
1442 	if (invalid & NFS_INO_INVALID_ATTR) {
1443 		nfs_inc_stats(inode, NFSIOS_ATTRINVALIDATE);
1444 		nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
1445 		nfsi->attrtimeo_timestamp = now;
1446 		nfsi->attr_gencount = nfs_inc_attr_generation_counter();
1447 	} else {
1448 		if (!time_in_range_open(now, nfsi->attrtimeo_timestamp, nfsi->attrtimeo_timestamp + nfsi->attrtimeo)) {
1449 			if ((nfsi->attrtimeo <<= 1) > NFS_MAXATTRTIMEO(inode))
1450 				nfsi->attrtimeo = NFS_MAXATTRTIMEO(inode);
1451 			nfsi->attrtimeo_timestamp = now;
1452 		}
1453 	}
1454 	invalid &= ~NFS_INO_INVALID_ATTR;
1455 	/* Don't invalidate the data if we were to blame */
1456 	if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)
1457 				|| S_ISLNK(inode->i_mode)))
1458 		invalid &= ~NFS_INO_INVALID_DATA;
1459 	if (!NFS_PROTO(inode)->have_delegation(inode, FMODE_READ) ||
1460 			(save_cache_validity & NFS_INO_REVAL_FORCED))
1461 		nfsi->cache_validity |= invalid;
1462 
1463 	return 0;
1464  out_err:
1465 	/*
1466 	 * No need to worry about unhashing the dentry, as the
1467 	 * lookup validation will know that the inode is bad.
1468 	 * (But we fall through to invalidate the caches.)
1469 	 */
1470 	nfs_invalidate_inode(inode);
1471 	return -ESTALE;
1472 }
1473 
1474 
1475 #ifdef CONFIG_NFS_V4
1476 
1477 /*
1478  * Clean out any remaining NFSv4 state that might be left over due
1479  * to open() calls that passed nfs_atomic_lookup, but failed to call
1480  * nfs_open().
1481  */
1482 void nfs4_evict_inode(struct inode *inode)
1483 {
1484 	truncate_inode_pages(&inode->i_data, 0);
1485 	clear_inode(inode);
1486 	pnfs_return_layout(inode);
1487 	pnfs_destroy_layout(NFS_I(inode));
1488 	/* If we are holding a delegation, return it! */
1489 	nfs_inode_return_delegation_noreclaim(inode);
1490 	/* First call standard NFS clear_inode() code */
1491 	nfs_clear_inode(inode);
1492 }
1493 #endif
1494 
1495 struct inode *nfs_alloc_inode(struct super_block *sb)
1496 {
1497 	struct nfs_inode *nfsi;
1498 	nfsi = (struct nfs_inode *)kmem_cache_alloc(nfs_inode_cachep, GFP_KERNEL);
1499 	if (!nfsi)
1500 		return NULL;
1501 	nfsi->flags = 0UL;
1502 	nfsi->cache_validity = 0UL;
1503 #ifdef CONFIG_NFS_V3_ACL
1504 	nfsi->acl_access = ERR_PTR(-EAGAIN);
1505 	nfsi->acl_default = ERR_PTR(-EAGAIN);
1506 #endif
1507 #ifdef CONFIG_NFS_V4
1508 	nfsi->nfs4_acl = NULL;
1509 #endif /* CONFIG_NFS_V4 */
1510 	return &nfsi->vfs_inode;
1511 }
1512 
1513 static void nfs_i_callback(struct rcu_head *head)
1514 {
1515 	struct inode *inode = container_of(head, struct inode, i_rcu);
1516 	kmem_cache_free(nfs_inode_cachep, NFS_I(inode));
1517 }
1518 
1519 void nfs_destroy_inode(struct inode *inode)
1520 {
1521 	call_rcu(&inode->i_rcu, nfs_i_callback);
1522 }
1523 
1524 static inline void nfs4_init_once(struct nfs_inode *nfsi)
1525 {
1526 #ifdef CONFIG_NFS_V4
1527 	INIT_LIST_HEAD(&nfsi->open_states);
1528 	nfsi->delegation = NULL;
1529 	nfsi->delegation_state = 0;
1530 	init_rwsem(&nfsi->rwsem);
1531 	nfsi->layout = NULL;
1532 #endif
1533 }
1534 
1535 static void init_once(void *foo)
1536 {
1537 	struct nfs_inode *nfsi = (struct nfs_inode *) foo;
1538 
1539 	inode_init_once(&nfsi->vfs_inode);
1540 	INIT_LIST_HEAD(&nfsi->open_files);
1541 	INIT_LIST_HEAD(&nfsi->access_cache_entry_lru);
1542 	INIT_LIST_HEAD(&nfsi->access_cache_inode_lru);
1543 	INIT_LIST_HEAD(&nfsi->commit_info.list);
1544 	nfsi->npages = 0;
1545 	nfsi->commit_info.ncommit = 0;
1546 	atomic_set(&nfsi->commit_info.rpcs_out, 0);
1547 	atomic_set(&nfsi->silly_count, 1);
1548 	INIT_HLIST_HEAD(&nfsi->silly_list);
1549 	init_waitqueue_head(&nfsi->waitqueue);
1550 	nfs4_init_once(nfsi);
1551 }
1552 
1553 static int __init nfs_init_inodecache(void)
1554 {
1555 	nfs_inode_cachep = kmem_cache_create("nfs_inode_cache",
1556 					     sizeof(struct nfs_inode),
1557 					     0, (SLAB_RECLAIM_ACCOUNT|
1558 						SLAB_MEM_SPREAD),
1559 					     init_once);
1560 	if (nfs_inode_cachep == NULL)
1561 		return -ENOMEM;
1562 
1563 	return 0;
1564 }
1565 
1566 static void nfs_destroy_inodecache(void)
1567 {
1568 	kmem_cache_destroy(nfs_inode_cachep);
1569 }
1570 
1571 struct workqueue_struct *nfsiod_workqueue;
1572 
1573 /*
1574  * start up the nfsiod workqueue
1575  */
1576 static int nfsiod_start(void)
1577 {
1578 	struct workqueue_struct *wq;
1579 	dprintk("RPC:       creating workqueue nfsiod\n");
1580 	wq = alloc_workqueue("nfsiod", WQ_MEM_RECLAIM, 0);
1581 	if (wq == NULL)
1582 		return -ENOMEM;
1583 	nfsiod_workqueue = wq;
1584 	return 0;
1585 }
1586 
1587 /*
1588  * Destroy the nfsiod workqueue
1589  */
1590 static void nfsiod_stop(void)
1591 {
1592 	struct workqueue_struct *wq;
1593 
1594 	wq = nfsiod_workqueue;
1595 	if (wq == NULL)
1596 		return;
1597 	nfsiod_workqueue = NULL;
1598 	destroy_workqueue(wq);
1599 }
1600 
1601 int nfs_net_id;
1602 EXPORT_SYMBOL_GPL(nfs_net_id);
1603 
1604 static int nfs_net_init(struct net *net)
1605 {
1606 	nfs_clients_init(net);
1607 	return nfs_dns_resolver_cache_init(net);
1608 }
1609 
1610 static void nfs_net_exit(struct net *net)
1611 {
1612 	nfs_dns_resolver_cache_destroy(net);
1613 	nfs_cleanup_cb_ident_idr(net);
1614 }
1615 
1616 static struct pernet_operations nfs_net_ops = {
1617 	.init = nfs_net_init,
1618 	.exit = nfs_net_exit,
1619 	.id   = &nfs_net_id,
1620 	.size = sizeof(struct nfs_net),
1621 };
1622 
1623 /*
1624  * Initialize NFS
1625  */
1626 static int __init init_nfs_fs(void)
1627 {
1628 	int err;
1629 
1630 	err = nfs_dns_resolver_init();
1631 	if (err < 0)
1632 		goto out11;
1633 
1634 	err = register_pernet_subsys(&nfs_net_ops);
1635 	if (err < 0)
1636 		goto out10;
1637 
1638 	err = nfs_fscache_register();
1639 	if (err < 0)
1640 		goto out9;
1641 
1642 	err = nfsiod_start();
1643 	if (err)
1644 		goto out8;
1645 
1646 	err = nfs_fs_proc_init();
1647 	if (err)
1648 		goto out7;
1649 
1650 	err = nfs_init_nfspagecache();
1651 	if (err)
1652 		goto out6;
1653 
1654 	err = nfs_init_inodecache();
1655 	if (err)
1656 		goto out5;
1657 
1658 	err = nfs_init_readpagecache();
1659 	if (err)
1660 		goto out4;
1661 
1662 	err = nfs_init_writepagecache();
1663 	if (err)
1664 		goto out3;
1665 
1666 	err = nfs_init_directcache();
1667 	if (err)
1668 		goto out2;
1669 
1670 #ifdef CONFIG_PROC_FS
1671 	rpc_proc_register(&init_net, &nfs_rpcstat);
1672 #endif
1673 
1674 #ifdef CONFIG_NFS_V4
1675 	err = init_nfs_v4();
1676 	if (err)
1677 		goto out1;
1678 #endif
1679 
1680 	if ((err = register_nfs_fs()) != 0)
1681 		goto out0;
1682 
1683 	return 0;
1684 out0:
1685 #ifdef CONFIG_NFS_V4
1686 	exit_nfs_v4();
1687 out1:
1688 #endif
1689 #ifdef CONFIG_PROC_FS
1690 	rpc_proc_unregister(&init_net, "nfs");
1691 #endif
1692 	nfs_destroy_directcache();
1693 out2:
1694 	nfs_destroy_writepagecache();
1695 out3:
1696 	nfs_destroy_readpagecache();
1697 out4:
1698 	nfs_destroy_inodecache();
1699 out5:
1700 	nfs_destroy_nfspagecache();
1701 out6:
1702 	nfs_fs_proc_exit();
1703 out7:
1704 	nfsiod_stop();
1705 out8:
1706 	nfs_fscache_unregister();
1707 out9:
1708 	unregister_pernet_subsys(&nfs_net_ops);
1709 out10:
1710 	nfs_dns_resolver_destroy();
1711 out11:
1712 	return err;
1713 }
1714 
1715 static void __exit exit_nfs_fs(void)
1716 {
1717 #ifdef CONFIG_NFS_V4
1718 	exit_nfs_v4();
1719 #endif
1720 	nfs_destroy_directcache();
1721 	nfs_destroy_writepagecache();
1722 	nfs_destroy_readpagecache();
1723 	nfs_destroy_inodecache();
1724 	nfs_destroy_nfspagecache();
1725 	nfs_fscache_unregister();
1726 	unregister_pernet_subsys(&nfs_net_ops);
1727 	nfs_dns_resolver_destroy();
1728 #ifdef CONFIG_PROC_FS
1729 	rpc_proc_unregister(&init_net, "nfs");
1730 #endif
1731 	unregister_nfs_fs();
1732 	nfs_fs_proc_exit();
1733 	nfsiod_stop();
1734 }
1735 
1736 /* Not quite true; I just maintain it */
1737 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
1738 MODULE_LICENSE("GPL");
1739 module_param(enable_ino64, bool, 0644);
1740 
1741 module_init(init_nfs_fs)
1742 module_exit(exit_nfs_fs)
1743