xref: /linux/fs/nfs/inode.c (revision c6bd5bcc4983f1a2d2f87a3769bf309482ee8c04)
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 "nfs.h"
54 #include "netns.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(void *word)
79 {
80 	if (fatal_signal_pending(current))
81 		return -ERESTARTSYS;
82 	freezable_schedule();
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 void nfs_clear_inode(struct inode *inode)
111 {
112 	/*
113 	 * The following should never happen...
114 	 */
115 	BUG_ON(nfs_have_writebacks(inode));
116 	BUG_ON(!list_empty(&NFS_I(inode)->open_files));
117 	nfs_zap_acl_cache(inode);
118 	nfs_access_zap_cache(inode);
119 	nfs_fscache_release_inode_cookie(inode);
120 }
121 EXPORT_SYMBOL_GPL(nfs_clear_inode);
122 
123 void nfs_evict_inode(struct inode *inode)
124 {
125 	truncate_inode_pages(&inode->i_data, 0);
126 	clear_inode(inode);
127 	nfs_clear_inode(inode);
128 }
129 
130 /**
131  * nfs_sync_mapping - helper to flush all mmapped dirty data to disk
132  */
133 int nfs_sync_mapping(struct address_space *mapping)
134 {
135 	int ret = 0;
136 
137 	if (mapping->nrpages != 0) {
138 		unmap_mapping_range(mapping, 0, 0, 0);
139 		ret = nfs_wb_all(mapping->host);
140 	}
141 	return ret;
142 }
143 
144 /*
145  * Invalidate the local caches
146  */
147 static void nfs_zap_caches_locked(struct inode *inode)
148 {
149 	struct nfs_inode *nfsi = NFS_I(inode);
150 	int mode = inode->i_mode;
151 
152 	nfs_inc_stats(inode, NFSIOS_ATTRINVALIDATE);
153 
154 	nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
155 	nfsi->attrtimeo_timestamp = jiffies;
156 
157 	memset(NFS_I(inode)->cookieverf, 0, sizeof(NFS_I(inode)->cookieverf));
158 	if (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))
159 		nfsi->cache_validity |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL|NFS_INO_REVAL_PAGECACHE;
160 	else
161 		nfsi->cache_validity |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL|NFS_INO_REVAL_PAGECACHE;
162 }
163 
164 void nfs_zap_caches(struct inode *inode)
165 {
166 	spin_lock(&inode->i_lock);
167 	nfs_zap_caches_locked(inode);
168 	spin_unlock(&inode->i_lock);
169 }
170 
171 void nfs_zap_mapping(struct inode *inode, struct address_space *mapping)
172 {
173 	if (mapping->nrpages != 0) {
174 		spin_lock(&inode->i_lock);
175 		NFS_I(inode)->cache_validity |= NFS_INO_INVALID_DATA;
176 		spin_unlock(&inode->i_lock);
177 	}
178 }
179 
180 void nfs_zap_acl_cache(struct inode *inode)
181 {
182 	void (*clear_acl_cache)(struct inode *);
183 
184 	clear_acl_cache = NFS_PROTO(inode)->clear_acl_cache;
185 	if (clear_acl_cache != NULL)
186 		clear_acl_cache(inode);
187 	spin_lock(&inode->i_lock);
188 	NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_ACL;
189 	spin_unlock(&inode->i_lock);
190 }
191 EXPORT_SYMBOL_GPL(nfs_zap_acl_cache);
192 
193 void nfs_invalidate_atime(struct inode *inode)
194 {
195 	spin_lock(&inode->i_lock);
196 	NFS_I(inode)->cache_validity |= NFS_INO_INVALID_ATIME;
197 	spin_unlock(&inode->i_lock);
198 }
199 EXPORT_SYMBOL_GPL(nfs_invalidate_atime);
200 
201 /*
202  * Invalidate, but do not unhash, the inode.
203  * NB: must be called with inode->i_lock held!
204  */
205 static void nfs_invalidate_inode(struct inode *inode)
206 {
207 	set_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
208 	nfs_zap_caches_locked(inode);
209 }
210 
211 struct nfs_find_desc {
212 	struct nfs_fh		*fh;
213 	struct nfs_fattr	*fattr;
214 };
215 
216 /*
217  * In NFSv3 we can have 64bit inode numbers. In order to support
218  * this, and re-exported directories (also seen in NFSv2)
219  * we are forced to allow 2 different inodes to have the same
220  * i_ino.
221  */
222 static int
223 nfs_find_actor(struct inode *inode, void *opaque)
224 {
225 	struct nfs_find_desc	*desc = (struct nfs_find_desc *)opaque;
226 	struct nfs_fh		*fh = desc->fh;
227 	struct nfs_fattr	*fattr = desc->fattr;
228 
229 	if (NFS_FILEID(inode) != fattr->fileid)
230 		return 0;
231 	if (nfs_compare_fh(NFS_FH(inode), fh))
232 		return 0;
233 	if (is_bad_inode(inode) || NFS_STALE(inode))
234 		return 0;
235 	return 1;
236 }
237 
238 static int
239 nfs_init_locked(struct inode *inode, void *opaque)
240 {
241 	struct nfs_find_desc	*desc = (struct nfs_find_desc *)opaque;
242 	struct nfs_fattr	*fattr = desc->fattr;
243 
244 	set_nfs_fileid(inode, fattr->fileid);
245 	nfs_copy_fh(NFS_FH(inode), desc->fh);
246 	return 0;
247 }
248 
249 /*
250  * This is our front-end to iget that looks up inodes by file handle
251  * instead of inode number.
252  */
253 struct inode *
254 nfs_fhget(struct super_block *sb, struct nfs_fh *fh, struct nfs_fattr *fattr)
255 {
256 	struct nfs_find_desc desc = {
257 		.fh	= fh,
258 		.fattr	= fattr
259 	};
260 	struct inode *inode = ERR_PTR(-ENOENT);
261 	unsigned long hash;
262 
263 	nfs_attr_check_mountpoint(sb, fattr);
264 
265 	if (((fattr->valid & NFS_ATTR_FATTR_FILEID) == 0) &&
266 	    !nfs_attr_use_mounted_on_fileid(fattr))
267 		goto out_no_inode;
268 	if ((fattr->valid & NFS_ATTR_FATTR_TYPE) == 0)
269 		goto out_no_inode;
270 
271 	hash = nfs_fattr_to_ino_t(fattr);
272 
273 	inode = iget5_locked(sb, hash, nfs_find_actor, nfs_init_locked, &desc);
274 	if (inode == NULL) {
275 		inode = ERR_PTR(-ENOMEM);
276 		goto out_no_inode;
277 	}
278 
279 	if (inode->i_state & I_NEW) {
280 		struct nfs_inode *nfsi = NFS_I(inode);
281 		unsigned long now = jiffies;
282 
283 		/* We set i_ino for the few things that still rely on it,
284 		 * such as stat(2) */
285 		inode->i_ino = hash;
286 
287 		/* We can't support update_atime(), since the server will reset it */
288 		inode->i_flags |= S_NOATIME|S_NOCMTIME;
289 		inode->i_mode = fattr->mode;
290 		if ((fattr->valid & NFS_ATTR_FATTR_MODE) == 0
291 				&& nfs_server_capable(inode, NFS_CAP_MODE))
292 			nfsi->cache_validity |= NFS_INO_INVALID_ATTR;
293 		/* Why so? Because we want revalidate for devices/FIFOs, and
294 		 * that's precisely what we have in nfs_file_inode_operations.
295 		 */
296 		inode->i_op = NFS_SB(sb)->nfs_client->rpc_ops->file_inode_ops;
297 		if (S_ISREG(inode->i_mode)) {
298 			inode->i_fop = NFS_SB(sb)->nfs_client->rpc_ops->file_ops;
299 			inode->i_data.a_ops = &nfs_file_aops;
300 			inode->i_data.backing_dev_info = &NFS_SB(sb)->backing_dev_info;
301 		} else if (S_ISDIR(inode->i_mode)) {
302 			inode->i_op = NFS_SB(sb)->nfs_client->rpc_ops->dir_inode_ops;
303 			inode->i_fop = &nfs_dir_operations;
304 			inode->i_data.a_ops = &nfs_dir_aops;
305 			/* Deal with crossing mountpoints */
306 			if (fattr->valid & NFS_ATTR_FATTR_MOUNTPOINT ||
307 					fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL) {
308 				if (fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL)
309 					inode->i_op = &nfs_referral_inode_operations;
310 				else
311 					inode->i_op = &nfs_mountpoint_inode_operations;
312 				inode->i_fop = NULL;
313 				inode->i_flags |= S_AUTOMOUNT;
314 			}
315 		} else if (S_ISLNK(inode->i_mode))
316 			inode->i_op = &nfs_symlink_inode_operations;
317 		else
318 			init_special_inode(inode, inode->i_mode, fattr->rdev);
319 
320 		memset(&inode->i_atime, 0, sizeof(inode->i_atime));
321 		memset(&inode->i_mtime, 0, sizeof(inode->i_mtime));
322 		memset(&inode->i_ctime, 0, sizeof(inode->i_ctime));
323 		inode->i_version = 0;
324 		inode->i_size = 0;
325 		clear_nlink(inode);
326 		inode->i_uid = -2;
327 		inode->i_gid = -2;
328 		inode->i_blocks = 0;
329 		memset(nfsi->cookieverf, 0, sizeof(nfsi->cookieverf));
330 		nfsi->write_io = 0;
331 		nfsi->read_io = 0;
332 
333 		nfsi->read_cache_jiffies = fattr->time_start;
334 		nfsi->attr_gencount = fattr->gencount;
335 		if (fattr->valid & NFS_ATTR_FATTR_ATIME)
336 			inode->i_atime = fattr->atime;
337 		else if (nfs_server_capable(inode, NFS_CAP_ATIME))
338 			nfsi->cache_validity |= NFS_INO_INVALID_ATTR;
339 		if (fattr->valid & NFS_ATTR_FATTR_MTIME)
340 			inode->i_mtime = fattr->mtime;
341 		else if (nfs_server_capable(inode, NFS_CAP_MTIME))
342 			nfsi->cache_validity |= NFS_INO_INVALID_ATTR;
343 		if (fattr->valid & NFS_ATTR_FATTR_CTIME)
344 			inode->i_ctime = fattr->ctime;
345 		else if (nfs_server_capable(inode, NFS_CAP_CTIME))
346 			nfsi->cache_validity |= NFS_INO_INVALID_ATTR;
347 		if (fattr->valid & NFS_ATTR_FATTR_CHANGE)
348 			inode->i_version = fattr->change_attr;
349 		else if (nfs_server_capable(inode, NFS_CAP_CHANGE_ATTR))
350 			nfsi->cache_validity |= NFS_INO_INVALID_ATTR;
351 		if (fattr->valid & NFS_ATTR_FATTR_SIZE)
352 			inode->i_size = nfs_size_to_loff_t(fattr->size);
353 		else
354 			nfsi->cache_validity |= NFS_INO_INVALID_ATTR
355 				| NFS_INO_REVAL_PAGECACHE;
356 		if (fattr->valid & NFS_ATTR_FATTR_NLINK)
357 			set_nlink(inode, fattr->nlink);
358 		else if (nfs_server_capable(inode, NFS_CAP_NLINK))
359 			nfsi->cache_validity |= NFS_INO_INVALID_ATTR;
360 		if (fattr->valid & NFS_ATTR_FATTR_OWNER)
361 			inode->i_uid = fattr->uid;
362 		else if (nfs_server_capable(inode, NFS_CAP_OWNER))
363 			nfsi->cache_validity |= NFS_INO_INVALID_ATTR;
364 		if (fattr->valid & NFS_ATTR_FATTR_GROUP)
365 			inode->i_gid = fattr->gid;
366 		else if (nfs_server_capable(inode, NFS_CAP_OWNER_GROUP))
367 			nfsi->cache_validity |= NFS_INO_INVALID_ATTR;
368 		if (fattr->valid & NFS_ATTR_FATTR_BLOCKS_USED)
369 			inode->i_blocks = fattr->du.nfs2.blocks;
370 		if (fattr->valid & NFS_ATTR_FATTR_SPACE_USED) {
371 			/*
372 			 * report the blocks in 512byte units
373 			 */
374 			inode->i_blocks = nfs_calc_block_size(fattr->du.nfs3.used);
375 		}
376 		nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
377 		nfsi->attrtimeo_timestamp = now;
378 		nfsi->access_cache = RB_ROOT;
379 
380 		nfs_fscache_init_inode_cookie(inode);
381 
382 		unlock_new_inode(inode);
383 	} else
384 		nfs_refresh_inode(inode, fattr);
385 	dprintk("NFS: nfs_fhget(%s/%Ld fh_crc=0x%08x ct=%d)\n",
386 		inode->i_sb->s_id,
387 		(long long)NFS_FILEID(inode),
388 		nfs_display_fhandle_hash(fh),
389 		atomic_read(&inode->i_count));
390 
391 out:
392 	return inode;
393 
394 out_no_inode:
395 	dprintk("nfs_fhget: iget failed with error %ld\n", PTR_ERR(inode));
396 	goto out;
397 }
398 EXPORT_SYMBOL_GPL(nfs_fhget);
399 
400 #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)
401 
402 int
403 nfs_setattr(struct dentry *dentry, struct iattr *attr)
404 {
405 	struct inode *inode = dentry->d_inode;
406 	struct nfs_fattr *fattr;
407 	int error = -ENOMEM;
408 
409 	nfs_inc_stats(inode, NFSIOS_VFSSETATTR);
410 
411 	/* skip mode change if it's just for clearing setuid/setgid */
412 	if (attr->ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
413 		attr->ia_valid &= ~ATTR_MODE;
414 
415 	if (attr->ia_valid & ATTR_SIZE) {
416 		if (!S_ISREG(inode->i_mode) || attr->ia_size == i_size_read(inode))
417 			attr->ia_valid &= ~ATTR_SIZE;
418 	}
419 
420 	/* Optimization: if the end result is no change, don't RPC */
421 	attr->ia_valid &= NFS_VALID_ATTRS;
422 	if ((attr->ia_valid & ~(ATTR_FILE|ATTR_OPEN)) == 0)
423 		return 0;
424 
425 	/* Write all dirty data */
426 	if (S_ISREG(inode->i_mode)) {
427 		nfs_inode_dio_wait(inode);
428 		nfs_wb_all(inode);
429 	}
430 
431 	fattr = nfs_alloc_fattr();
432 	if (fattr == NULL)
433 		goto out;
434 	/*
435 	 * Return any delegations if we're going to change ACLs
436 	 */
437 	if ((attr->ia_valid & (ATTR_MODE|ATTR_UID|ATTR_GID)) != 0)
438 		NFS_PROTO(inode)->return_delegation(inode);
439 	error = NFS_PROTO(inode)->setattr(dentry, fattr, attr);
440 	if (error == 0)
441 		nfs_refresh_inode(inode, fattr);
442 	nfs_free_fattr(fattr);
443 out:
444 	return error;
445 }
446 EXPORT_SYMBOL_GPL(nfs_setattr);
447 
448 /**
449  * nfs_vmtruncate - unmap mappings "freed" by truncate() syscall
450  * @inode: inode of the file used
451  * @offset: file offset to start truncating
452  *
453  * This is a copy of the common vmtruncate, but with the locking
454  * corrected to take into account the fact that NFS requires
455  * inode->i_size to be updated under the inode->i_lock.
456  */
457 static int nfs_vmtruncate(struct inode * inode, loff_t offset)
458 {
459 	loff_t oldsize;
460 	int err;
461 
462 	err = inode_newsize_ok(inode, offset);
463 	if (err)
464 		goto out;
465 
466 	spin_lock(&inode->i_lock);
467 	oldsize = inode->i_size;
468 	i_size_write(inode, offset);
469 	spin_unlock(&inode->i_lock);
470 
471 	truncate_pagecache(inode, oldsize, offset);
472 out:
473 	return err;
474 }
475 
476 /**
477  * nfs_setattr_update_inode - Update inode metadata after a setattr call.
478  * @inode: pointer to struct inode
479  * @attr: pointer to struct iattr
480  *
481  * Note: we do this in the *proc.c in order to ensure that
482  *       it works for things like exclusive creates too.
483  */
484 void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr)
485 {
486 	if ((attr->ia_valid & (ATTR_MODE|ATTR_UID|ATTR_GID)) != 0) {
487 		spin_lock(&inode->i_lock);
488 		if ((attr->ia_valid & ATTR_MODE) != 0) {
489 			int mode = attr->ia_mode & S_IALLUGO;
490 			mode |= inode->i_mode & ~S_IALLUGO;
491 			inode->i_mode = mode;
492 		}
493 		if ((attr->ia_valid & ATTR_UID) != 0)
494 			inode->i_uid = attr->ia_uid;
495 		if ((attr->ia_valid & ATTR_GID) != 0)
496 			inode->i_gid = attr->ia_gid;
497 		NFS_I(inode)->cache_validity |= NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
498 		spin_unlock(&inode->i_lock);
499 	}
500 	if ((attr->ia_valid & ATTR_SIZE) != 0) {
501 		nfs_inc_stats(inode, NFSIOS_SETATTRTRUNC);
502 		nfs_vmtruncate(inode, attr->ia_size);
503 	}
504 }
505 EXPORT_SYMBOL_GPL(nfs_setattr_update_inode);
506 
507 int nfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
508 {
509 	struct inode *inode = dentry->d_inode;
510 	int need_atime = NFS_I(inode)->cache_validity & NFS_INO_INVALID_ATIME;
511 	int err;
512 
513 	/* Flush out writes to the server in order to update c/mtime.  */
514 	if (S_ISREG(inode->i_mode)) {
515 		nfs_inode_dio_wait(inode);
516 		err = filemap_write_and_wait(inode->i_mapping);
517 		if (err)
518 			goto out;
519 	}
520 
521 	/*
522 	 * We may force a getattr if the user cares about atime.
523 	 *
524 	 * Note that we only have to check the vfsmount flags here:
525 	 *  - NFS always sets S_NOATIME by so checking it would give a
526 	 *    bogus result
527 	 *  - NFS never sets MS_NOATIME or MS_NODIRATIME so there is
528 	 *    no point in checking those.
529 	 */
530  	if ((mnt->mnt_flags & MNT_NOATIME) ||
531  	    ((mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode)))
532 		need_atime = 0;
533 
534 	if (need_atime)
535 		err = __nfs_revalidate_inode(NFS_SERVER(inode), inode);
536 	else
537 		err = nfs_revalidate_inode(NFS_SERVER(inode), inode);
538 	if (!err) {
539 		generic_fillattr(inode, stat);
540 		stat->ino = nfs_compat_user_ino64(NFS_FILEID(inode));
541 	}
542 out:
543 	return err;
544 }
545 EXPORT_SYMBOL_GPL(nfs_getattr);
546 
547 static void nfs_init_lock_context(struct nfs_lock_context *l_ctx)
548 {
549 	atomic_set(&l_ctx->count, 1);
550 	l_ctx->lockowner.l_owner = current->files;
551 	l_ctx->lockowner.l_pid = current->tgid;
552 	INIT_LIST_HEAD(&l_ctx->list);
553 }
554 
555 static struct nfs_lock_context *__nfs_find_lock_context(struct nfs_open_context *ctx)
556 {
557 	struct nfs_lock_context *pos;
558 
559 	list_for_each_entry(pos, &ctx->lock_context.list, list) {
560 		if (pos->lockowner.l_owner != current->files)
561 			continue;
562 		if (pos->lockowner.l_pid != current->tgid)
563 			continue;
564 		atomic_inc(&pos->count);
565 		return pos;
566 	}
567 	return NULL;
568 }
569 
570 struct nfs_lock_context *nfs_get_lock_context(struct nfs_open_context *ctx)
571 {
572 	struct nfs_lock_context *res, *new = NULL;
573 	struct inode *inode = ctx->dentry->d_inode;
574 
575 	spin_lock(&inode->i_lock);
576 	res = __nfs_find_lock_context(ctx);
577 	if (res == NULL) {
578 		spin_unlock(&inode->i_lock);
579 		new = kmalloc(sizeof(*new), GFP_KERNEL);
580 		if (new == NULL)
581 			return ERR_PTR(-ENOMEM);
582 		nfs_init_lock_context(new);
583 		spin_lock(&inode->i_lock);
584 		res = __nfs_find_lock_context(ctx);
585 		if (res == NULL) {
586 			list_add_tail(&new->list, &ctx->lock_context.list);
587 			new->open_context = ctx;
588 			res = new;
589 			new = NULL;
590 		}
591 	}
592 	spin_unlock(&inode->i_lock);
593 	kfree(new);
594 	return res;
595 }
596 
597 void nfs_put_lock_context(struct nfs_lock_context *l_ctx)
598 {
599 	struct nfs_open_context *ctx = l_ctx->open_context;
600 	struct inode *inode = ctx->dentry->d_inode;
601 
602 	if (!atomic_dec_and_lock(&l_ctx->count, &inode->i_lock))
603 		return;
604 	list_del(&l_ctx->list);
605 	spin_unlock(&inode->i_lock);
606 	kfree(l_ctx);
607 }
608 
609 /**
610  * nfs_close_context - Common close_context() routine NFSv2/v3
611  * @ctx: pointer to context
612  * @is_sync: is this a synchronous close
613  *
614  * always ensure that the attributes are up to date if we're mounted
615  * with close-to-open semantics
616  */
617 void nfs_close_context(struct nfs_open_context *ctx, int is_sync)
618 {
619 	struct inode *inode;
620 	struct nfs_server *server;
621 
622 	if (!(ctx->mode & FMODE_WRITE))
623 		return;
624 	if (!is_sync)
625 		return;
626 	inode = ctx->dentry->d_inode;
627 	if (!list_empty(&NFS_I(inode)->open_files))
628 		return;
629 	server = NFS_SERVER(inode);
630 	if (server->flags & NFS_MOUNT_NOCTO)
631 		return;
632 	nfs_revalidate_inode(server, inode);
633 }
634 EXPORT_SYMBOL_GPL(nfs_close_context);
635 
636 struct nfs_open_context *alloc_nfs_open_context(struct dentry *dentry, fmode_t f_mode)
637 {
638 	struct nfs_open_context *ctx;
639 	struct rpc_cred *cred = rpc_lookup_cred();
640 	if (IS_ERR(cred))
641 		return ERR_CAST(cred);
642 
643 	ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
644 	if (!ctx) {
645 		put_rpccred(cred);
646 		return ERR_PTR(-ENOMEM);
647 	}
648 	nfs_sb_active(dentry->d_sb);
649 	ctx->dentry = dget(dentry);
650 	ctx->cred = cred;
651 	ctx->state = NULL;
652 	ctx->mode = f_mode;
653 	ctx->flags = 0;
654 	ctx->error = 0;
655 	nfs_init_lock_context(&ctx->lock_context);
656 	ctx->lock_context.open_context = ctx;
657 	INIT_LIST_HEAD(&ctx->list);
658 	ctx->mdsthreshold = NULL;
659 	return ctx;
660 }
661 EXPORT_SYMBOL_GPL(alloc_nfs_open_context);
662 
663 struct nfs_open_context *get_nfs_open_context(struct nfs_open_context *ctx)
664 {
665 	if (ctx != NULL)
666 		atomic_inc(&ctx->lock_context.count);
667 	return ctx;
668 }
669 EXPORT_SYMBOL_GPL(get_nfs_open_context);
670 
671 static void __put_nfs_open_context(struct nfs_open_context *ctx, int is_sync)
672 {
673 	struct inode *inode = ctx->dentry->d_inode;
674 	struct super_block *sb = ctx->dentry->d_sb;
675 
676 	if (!list_empty(&ctx->list)) {
677 		if (!atomic_dec_and_lock(&ctx->lock_context.count, &inode->i_lock))
678 			return;
679 		list_del(&ctx->list);
680 		spin_unlock(&inode->i_lock);
681 	} else if (!atomic_dec_and_test(&ctx->lock_context.count))
682 		return;
683 	if (inode != NULL)
684 		NFS_PROTO(inode)->close_context(ctx, is_sync);
685 	if (ctx->cred != NULL)
686 		put_rpccred(ctx->cred);
687 	dput(ctx->dentry);
688 	if (is_sync)
689 		nfs_sb_deactive(sb);
690 	else
691 		nfs_sb_deactive_async(sb);
692 	kfree(ctx->mdsthreshold);
693 	kfree(ctx);
694 }
695 
696 void put_nfs_open_context(struct nfs_open_context *ctx)
697 {
698 	__put_nfs_open_context(ctx, 0);
699 }
700 EXPORT_SYMBOL_GPL(put_nfs_open_context);
701 
702 /*
703  * Ensure that mmap has a recent RPC credential for use when writing out
704  * shared pages
705  */
706 void nfs_file_set_open_context(struct file *filp, struct nfs_open_context *ctx)
707 {
708 	struct inode *inode = filp->f_path.dentry->d_inode;
709 	struct nfs_inode *nfsi = NFS_I(inode);
710 
711 	filp->private_data = get_nfs_open_context(ctx);
712 	spin_lock(&inode->i_lock);
713 	list_add(&ctx->list, &nfsi->open_files);
714 	spin_unlock(&inode->i_lock);
715 }
716 EXPORT_SYMBOL_GPL(nfs_file_set_open_context);
717 
718 /*
719  * Given an inode, search for an open context with the desired characteristics
720  */
721 struct nfs_open_context *nfs_find_open_context(struct inode *inode, struct rpc_cred *cred, fmode_t mode)
722 {
723 	struct nfs_inode *nfsi = NFS_I(inode);
724 	struct nfs_open_context *pos, *ctx = NULL;
725 
726 	spin_lock(&inode->i_lock);
727 	list_for_each_entry(pos, &nfsi->open_files, list) {
728 		if (cred != NULL && pos->cred != cred)
729 			continue;
730 		if ((pos->mode & (FMODE_READ|FMODE_WRITE)) != mode)
731 			continue;
732 		ctx = get_nfs_open_context(pos);
733 		break;
734 	}
735 	spin_unlock(&inode->i_lock);
736 	return ctx;
737 }
738 
739 static void nfs_file_clear_open_context(struct file *filp)
740 {
741 	struct inode *inode = filp->f_path.dentry->d_inode;
742 	struct nfs_open_context *ctx = nfs_file_open_context(filp);
743 
744 	if (ctx) {
745 		filp->private_data = NULL;
746 		spin_lock(&inode->i_lock);
747 		list_move_tail(&ctx->list, &NFS_I(inode)->open_files);
748 		spin_unlock(&inode->i_lock);
749 		__put_nfs_open_context(ctx, filp->f_flags & O_DIRECT ? 0 : 1);
750 	}
751 }
752 
753 /*
754  * These allocate and release file read/write context information.
755  */
756 int nfs_open(struct inode *inode, struct file *filp)
757 {
758 	struct nfs_open_context *ctx;
759 
760 	ctx = alloc_nfs_open_context(filp->f_path.dentry, filp->f_mode);
761 	if (IS_ERR(ctx))
762 		return PTR_ERR(ctx);
763 	nfs_file_set_open_context(filp, ctx);
764 	put_nfs_open_context(ctx);
765 	nfs_fscache_set_inode_cookie(inode, filp);
766 	return 0;
767 }
768 
769 int nfs_release(struct inode *inode, struct file *filp)
770 {
771 	nfs_file_clear_open_context(filp);
772 	return 0;
773 }
774 
775 /*
776  * This function is called whenever some part of NFS notices that
777  * the cached attributes have to be refreshed.
778  */
779 int
780 __nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
781 {
782 	int		 status = -ESTALE;
783 	struct nfs_fattr *fattr = NULL;
784 	struct nfs_inode *nfsi = NFS_I(inode);
785 
786 	dfprintk(PAGECACHE, "NFS: revalidating (%s/%Ld)\n",
787 		inode->i_sb->s_id, (long long)NFS_FILEID(inode));
788 
789 	if (is_bad_inode(inode))
790 		goto out;
791 	if (NFS_STALE(inode))
792 		goto out;
793 
794 	status = -ENOMEM;
795 	fattr = nfs_alloc_fattr();
796 	if (fattr == NULL)
797 		goto out;
798 
799 	nfs_inc_stats(inode, NFSIOS_INODEREVALIDATE);
800 	status = NFS_PROTO(inode)->getattr(server, NFS_FH(inode), fattr);
801 	if (status != 0) {
802 		dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Ld) getattr failed, error=%d\n",
803 			 inode->i_sb->s_id,
804 			 (long long)NFS_FILEID(inode), status);
805 		if (status == -ESTALE) {
806 			nfs_zap_caches(inode);
807 			if (!S_ISDIR(inode->i_mode))
808 				set_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
809 		}
810 		goto out;
811 	}
812 
813 	status = nfs_refresh_inode(inode, fattr);
814 	if (status) {
815 		dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Ld) refresh failed, error=%d\n",
816 			 inode->i_sb->s_id,
817 			 (long long)NFS_FILEID(inode), status);
818 		goto out;
819 	}
820 
821 	if (nfsi->cache_validity & NFS_INO_INVALID_ACL)
822 		nfs_zap_acl_cache(inode);
823 
824 	dfprintk(PAGECACHE, "NFS: (%s/%Ld) revalidation complete\n",
825 		inode->i_sb->s_id,
826 		(long long)NFS_FILEID(inode));
827 
828  out:
829 	nfs_free_fattr(fattr);
830 	return status;
831 }
832 
833 int nfs_attribute_timeout(struct inode *inode)
834 {
835 	struct nfs_inode *nfsi = NFS_I(inode);
836 
837 	return !time_in_range_open(jiffies, nfsi->read_cache_jiffies, nfsi->read_cache_jiffies + nfsi->attrtimeo);
838 }
839 
840 static int nfs_attribute_cache_expired(struct inode *inode)
841 {
842 	if (nfs_have_delegated_attributes(inode))
843 		return 0;
844 	return nfs_attribute_timeout(inode);
845 }
846 
847 /**
848  * nfs_revalidate_inode - Revalidate the inode attributes
849  * @server - pointer to nfs_server struct
850  * @inode - pointer to inode struct
851  *
852  * Updates inode attribute information by retrieving the data from the server.
853  */
854 int nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
855 {
856 	if (!(NFS_I(inode)->cache_validity & NFS_INO_INVALID_ATTR)
857 			&& !nfs_attribute_cache_expired(inode))
858 		return NFS_STALE(inode) ? -ESTALE : 0;
859 	return __nfs_revalidate_inode(server, inode);
860 }
861 EXPORT_SYMBOL_GPL(nfs_revalidate_inode);
862 
863 static int nfs_invalidate_mapping(struct inode *inode, struct address_space *mapping)
864 {
865 	struct nfs_inode *nfsi = NFS_I(inode);
866 
867 	if (mapping->nrpages != 0) {
868 		int ret = invalidate_inode_pages2(mapping);
869 		if (ret < 0)
870 			return ret;
871 	}
872 	spin_lock(&inode->i_lock);
873 	nfsi->cache_validity &= ~NFS_INO_INVALID_DATA;
874 	if (S_ISDIR(inode->i_mode))
875 		memset(nfsi->cookieverf, 0, sizeof(nfsi->cookieverf));
876 	spin_unlock(&inode->i_lock);
877 	nfs_inc_stats(inode, NFSIOS_DATAINVALIDATE);
878 	nfs_fscache_reset_inode_cookie(inode);
879 	dfprintk(PAGECACHE, "NFS: (%s/%Ld) data cache invalidated\n",
880 			inode->i_sb->s_id, (long long)NFS_FILEID(inode));
881 	return 0;
882 }
883 
884 static bool nfs_mapping_need_revalidate_inode(struct inode *inode)
885 {
886 	if (nfs_have_delegated_attributes(inode))
887 		return false;
888 	return (NFS_I(inode)->cache_validity & NFS_INO_REVAL_PAGECACHE)
889 		|| nfs_attribute_timeout(inode)
890 		|| NFS_STALE(inode);
891 }
892 
893 /**
894  * nfs_revalidate_mapping - Revalidate the pagecache
895  * @inode - pointer to host inode
896  * @mapping - pointer to mapping
897  */
898 int nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping)
899 {
900 	struct nfs_inode *nfsi = NFS_I(inode);
901 	int ret = 0;
902 
903 	/* swapfiles are not supposed to be shared. */
904 	if (IS_SWAPFILE(inode))
905 		goto out;
906 
907 	if (nfs_mapping_need_revalidate_inode(inode)) {
908 		ret = __nfs_revalidate_inode(NFS_SERVER(inode), inode);
909 		if (ret < 0)
910 			goto out;
911 	}
912 	if (nfsi->cache_validity & NFS_INO_INVALID_DATA)
913 		ret = nfs_invalidate_mapping(inode, mapping);
914 out:
915 	return ret;
916 }
917 
918 static unsigned long nfs_wcc_update_inode(struct inode *inode, struct nfs_fattr *fattr)
919 {
920 	struct nfs_inode *nfsi = NFS_I(inode);
921 	unsigned long ret = 0;
922 
923 	if ((fattr->valid & NFS_ATTR_FATTR_PRECHANGE)
924 			&& (fattr->valid & NFS_ATTR_FATTR_CHANGE)
925 			&& inode->i_version == fattr->pre_change_attr) {
926 		inode->i_version = fattr->change_attr;
927 		if (S_ISDIR(inode->i_mode))
928 			nfsi->cache_validity |= NFS_INO_INVALID_DATA;
929 		ret |= NFS_INO_INVALID_ATTR;
930 	}
931 	/* If we have atomic WCC data, we may update some attributes */
932 	if ((fattr->valid & NFS_ATTR_FATTR_PRECTIME)
933 			&& (fattr->valid & NFS_ATTR_FATTR_CTIME)
934 			&& timespec_equal(&inode->i_ctime, &fattr->pre_ctime)) {
935 		memcpy(&inode->i_ctime, &fattr->ctime, sizeof(inode->i_ctime));
936 		ret |= NFS_INO_INVALID_ATTR;
937 	}
938 
939 	if ((fattr->valid & NFS_ATTR_FATTR_PREMTIME)
940 			&& (fattr->valid & NFS_ATTR_FATTR_MTIME)
941 			&& timespec_equal(&inode->i_mtime, &fattr->pre_mtime)) {
942 		memcpy(&inode->i_mtime, &fattr->mtime, sizeof(inode->i_mtime));
943 		if (S_ISDIR(inode->i_mode))
944 			nfsi->cache_validity |= NFS_INO_INVALID_DATA;
945 		ret |= NFS_INO_INVALID_ATTR;
946 	}
947 	if ((fattr->valid & NFS_ATTR_FATTR_PRESIZE)
948 			&& (fattr->valid & NFS_ATTR_FATTR_SIZE)
949 			&& i_size_read(inode) == nfs_size_to_loff_t(fattr->pre_size)
950 			&& nfsi->npages == 0) {
951 		i_size_write(inode, nfs_size_to_loff_t(fattr->size));
952 		ret |= NFS_INO_INVALID_ATTR;
953 	}
954 	return ret;
955 }
956 
957 /**
958  * nfs_check_inode_attributes - verify consistency of the inode attribute cache
959  * @inode - pointer to inode
960  * @fattr - updated attributes
961  *
962  * Verifies the attribute cache. If we have just changed the attributes,
963  * so that fattr carries weak cache consistency data, then it may
964  * also update the ctime/mtime/change_attribute.
965  */
966 static int nfs_check_inode_attributes(struct inode *inode, struct nfs_fattr *fattr)
967 {
968 	struct nfs_inode *nfsi = NFS_I(inode);
969 	loff_t cur_size, new_isize;
970 	unsigned long invalid = 0;
971 
972 
973 	if (nfs_have_delegated_attributes(inode))
974 		return 0;
975 	/* Has the inode gone and changed behind our back? */
976 	if ((fattr->valid & NFS_ATTR_FATTR_FILEID) && nfsi->fileid != fattr->fileid)
977 		return -EIO;
978 	if ((fattr->valid & NFS_ATTR_FATTR_TYPE) && (inode->i_mode & S_IFMT) != (fattr->mode & S_IFMT))
979 		return -EIO;
980 
981 	if ((fattr->valid & NFS_ATTR_FATTR_CHANGE) != 0 &&
982 			inode->i_version != fattr->change_attr)
983 		invalid |= NFS_INO_INVALID_ATTR|NFS_INO_REVAL_PAGECACHE;
984 
985 	/* Verify a few of the more important attributes */
986 	if ((fattr->valid & NFS_ATTR_FATTR_MTIME) && !timespec_equal(&inode->i_mtime, &fattr->mtime))
987 		invalid |= NFS_INO_INVALID_ATTR;
988 
989 	if (fattr->valid & NFS_ATTR_FATTR_SIZE) {
990 		cur_size = i_size_read(inode);
991 		new_isize = nfs_size_to_loff_t(fattr->size);
992 		if (cur_size != new_isize && nfsi->npages == 0)
993 			invalid |= NFS_INO_INVALID_ATTR|NFS_INO_REVAL_PAGECACHE;
994 	}
995 
996 	/* Have any file permissions changed? */
997 	if ((fattr->valid & NFS_ATTR_FATTR_MODE) && (inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO))
998 		invalid |= NFS_INO_INVALID_ATTR | NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL;
999 	if ((fattr->valid & NFS_ATTR_FATTR_OWNER) && inode->i_uid != fattr->uid)
1000 		invalid |= NFS_INO_INVALID_ATTR | NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL;
1001 	if ((fattr->valid & NFS_ATTR_FATTR_GROUP) && inode->i_gid != fattr->gid)
1002 		invalid |= NFS_INO_INVALID_ATTR | NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL;
1003 
1004 	/* Has the link count changed? */
1005 	if ((fattr->valid & NFS_ATTR_FATTR_NLINK) && inode->i_nlink != fattr->nlink)
1006 		invalid |= NFS_INO_INVALID_ATTR;
1007 
1008 	if ((fattr->valid & NFS_ATTR_FATTR_ATIME) && !timespec_equal(&inode->i_atime, &fattr->atime))
1009 		invalid |= NFS_INO_INVALID_ATIME;
1010 
1011 	if (invalid != 0)
1012 		nfsi->cache_validity |= invalid;
1013 
1014 	nfsi->read_cache_jiffies = fattr->time_start;
1015 	return 0;
1016 }
1017 
1018 static int nfs_ctime_need_update(const struct inode *inode, const struct nfs_fattr *fattr)
1019 {
1020 	if (!(fattr->valid & NFS_ATTR_FATTR_CTIME))
1021 		return 0;
1022 	return timespec_compare(&fattr->ctime, &inode->i_ctime) > 0;
1023 }
1024 
1025 static int nfs_size_need_update(const struct inode *inode, const struct nfs_fattr *fattr)
1026 {
1027 	if (!(fattr->valid & NFS_ATTR_FATTR_SIZE))
1028 		return 0;
1029 	return nfs_size_to_loff_t(fattr->size) > i_size_read(inode);
1030 }
1031 
1032 static atomic_long_t nfs_attr_generation_counter;
1033 
1034 static unsigned long nfs_read_attr_generation_counter(void)
1035 {
1036 	return atomic_long_read(&nfs_attr_generation_counter);
1037 }
1038 
1039 unsigned long nfs_inc_attr_generation_counter(void)
1040 {
1041 	return atomic_long_inc_return(&nfs_attr_generation_counter);
1042 }
1043 
1044 void nfs_fattr_init(struct nfs_fattr *fattr)
1045 {
1046 	fattr->valid = 0;
1047 	fattr->time_start = jiffies;
1048 	fattr->gencount = nfs_inc_attr_generation_counter();
1049 	fattr->owner_name = NULL;
1050 	fattr->group_name = NULL;
1051 }
1052 EXPORT_SYMBOL_GPL(nfs_fattr_init);
1053 
1054 struct nfs_fattr *nfs_alloc_fattr(void)
1055 {
1056 	struct nfs_fattr *fattr;
1057 
1058 	fattr = kmalloc(sizeof(*fattr), GFP_NOFS);
1059 	if (fattr != NULL)
1060 		nfs_fattr_init(fattr);
1061 	return fattr;
1062 }
1063 EXPORT_SYMBOL_GPL(nfs_alloc_fattr);
1064 
1065 struct nfs_fh *nfs_alloc_fhandle(void)
1066 {
1067 	struct nfs_fh *fh;
1068 
1069 	fh = kmalloc(sizeof(struct nfs_fh), GFP_NOFS);
1070 	if (fh != NULL)
1071 		fh->size = 0;
1072 	return fh;
1073 }
1074 EXPORT_SYMBOL_GPL(nfs_alloc_fhandle);
1075 
1076 #ifdef NFS_DEBUG
1077 /*
1078  * _nfs_display_fhandle_hash - calculate the crc32 hash for the filehandle
1079  *                             in the same way that wireshark does
1080  *
1081  * @fh: file handle
1082  *
1083  * For debugging only.
1084  */
1085 u32 _nfs_display_fhandle_hash(const struct nfs_fh *fh)
1086 {
1087 	/* wireshark uses 32-bit AUTODIN crc and does a bitwise
1088 	 * not on the result */
1089 	return ~crc32(0xFFFFFFFF, &fh->data[0], fh->size);
1090 }
1091 
1092 /*
1093  * _nfs_display_fhandle - display an NFS file handle on the console
1094  *
1095  * @fh: file handle to display
1096  * @caption: display caption
1097  *
1098  * For debugging only.
1099  */
1100 void _nfs_display_fhandle(const struct nfs_fh *fh, const char *caption)
1101 {
1102 	unsigned short i;
1103 
1104 	if (fh == NULL || fh->size == 0) {
1105 		printk(KERN_DEFAULT "%s at %p is empty\n", caption, fh);
1106 		return;
1107 	}
1108 
1109 	printk(KERN_DEFAULT "%s at %p is %u bytes, crc: 0x%08x:\n",
1110 	       caption, fh, fh->size, _nfs_display_fhandle_hash(fh));
1111 	for (i = 0; i < fh->size; i += 16) {
1112 		__be32 *pos = (__be32 *)&fh->data[i];
1113 
1114 		switch ((fh->size - i - 1) >> 2) {
1115 		case 0:
1116 			printk(KERN_DEFAULT " %08x\n",
1117 				be32_to_cpup(pos));
1118 			break;
1119 		case 1:
1120 			printk(KERN_DEFAULT " %08x %08x\n",
1121 				be32_to_cpup(pos), be32_to_cpup(pos + 1));
1122 			break;
1123 		case 2:
1124 			printk(KERN_DEFAULT " %08x %08x %08x\n",
1125 				be32_to_cpup(pos), be32_to_cpup(pos + 1),
1126 				be32_to_cpup(pos + 2));
1127 			break;
1128 		default:
1129 			printk(KERN_DEFAULT " %08x %08x %08x %08x\n",
1130 				be32_to_cpup(pos), be32_to_cpup(pos + 1),
1131 				be32_to_cpup(pos + 2), be32_to_cpup(pos + 3));
1132 		}
1133 	}
1134 }
1135 #endif
1136 
1137 /**
1138  * nfs_inode_attrs_need_update - check if the inode attributes need updating
1139  * @inode - pointer to inode
1140  * @fattr - attributes
1141  *
1142  * Attempt to divine whether or not an RPC call reply carrying stale
1143  * attributes got scheduled after another call carrying updated ones.
1144  *
1145  * To do so, the function first assumes that a more recent ctime means
1146  * that the attributes in fattr are newer, however it also attempt to
1147  * catch the case where ctime either didn't change, or went backwards
1148  * (if someone reset the clock on the server) by looking at whether
1149  * or not this RPC call was started after the inode was last updated.
1150  * Note also the check for wraparound of 'attr_gencount'
1151  *
1152  * The function returns 'true' if it thinks the attributes in 'fattr' are
1153  * more recent than the ones cached in the inode.
1154  *
1155  */
1156 static int nfs_inode_attrs_need_update(const struct inode *inode, const struct nfs_fattr *fattr)
1157 {
1158 	const struct nfs_inode *nfsi = NFS_I(inode);
1159 
1160 	return ((long)fattr->gencount - (long)nfsi->attr_gencount) > 0 ||
1161 		nfs_ctime_need_update(inode, fattr) ||
1162 		nfs_size_need_update(inode, fattr) ||
1163 		((long)nfsi->attr_gencount - (long)nfs_read_attr_generation_counter() > 0);
1164 }
1165 
1166 static int nfs_refresh_inode_locked(struct inode *inode, struct nfs_fattr *fattr)
1167 {
1168 	if (nfs_inode_attrs_need_update(inode, fattr))
1169 		return nfs_update_inode(inode, fattr);
1170 	return nfs_check_inode_attributes(inode, fattr);
1171 }
1172 
1173 /**
1174  * nfs_refresh_inode - try to update the inode attribute cache
1175  * @inode - pointer to inode
1176  * @fattr - updated attributes
1177  *
1178  * Check that an RPC call that returned attributes has not overlapped with
1179  * other recent updates of the inode metadata, then decide whether it is
1180  * safe to do a full update of the inode attributes, or whether just to
1181  * call nfs_check_inode_attributes.
1182  */
1183 int nfs_refresh_inode(struct inode *inode, struct nfs_fattr *fattr)
1184 {
1185 	int status;
1186 
1187 	if ((fattr->valid & NFS_ATTR_FATTR) == 0)
1188 		return 0;
1189 	spin_lock(&inode->i_lock);
1190 	status = nfs_refresh_inode_locked(inode, fattr);
1191 	spin_unlock(&inode->i_lock);
1192 
1193 	return status;
1194 }
1195 EXPORT_SYMBOL_GPL(nfs_refresh_inode);
1196 
1197 static int nfs_post_op_update_inode_locked(struct inode *inode, struct nfs_fattr *fattr)
1198 {
1199 	struct nfs_inode *nfsi = NFS_I(inode);
1200 
1201 	nfsi->cache_validity |= NFS_INO_INVALID_ATTR|NFS_INO_REVAL_PAGECACHE;
1202 	if (S_ISDIR(inode->i_mode))
1203 		nfsi->cache_validity |= NFS_INO_INVALID_DATA;
1204 	if ((fattr->valid & NFS_ATTR_FATTR) == 0)
1205 		return 0;
1206 	return nfs_refresh_inode_locked(inode, fattr);
1207 }
1208 
1209 /**
1210  * nfs_post_op_update_inode - try to update the inode attribute cache
1211  * @inode - pointer to inode
1212  * @fattr - updated attributes
1213  *
1214  * After an operation that has changed the inode metadata, mark the
1215  * attribute cache as being invalid, then try to update it.
1216  *
1217  * NB: if the server didn't return any post op attributes, this
1218  * function will force the retrieval of attributes before the next
1219  * NFS request.  Thus it should be used only for operations that
1220  * are expected to change one or more attributes, to avoid
1221  * unnecessary NFS requests and trips through nfs_update_inode().
1222  */
1223 int nfs_post_op_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1224 {
1225 	int status;
1226 
1227 	spin_lock(&inode->i_lock);
1228 	status = nfs_post_op_update_inode_locked(inode, fattr);
1229 	spin_unlock(&inode->i_lock);
1230 	return status;
1231 }
1232 EXPORT_SYMBOL_GPL(nfs_post_op_update_inode);
1233 
1234 /**
1235  * nfs_post_op_update_inode_force_wcc - try to update the inode attribute cache
1236  * @inode - pointer to inode
1237  * @fattr - updated attributes
1238  *
1239  * After an operation that has changed the inode metadata, mark the
1240  * attribute cache as being invalid, then try to update it. Fake up
1241  * weak cache consistency data, if none exist.
1242  *
1243  * This function is mainly designed to be used by the ->write_done() functions.
1244  */
1245 int nfs_post_op_update_inode_force_wcc(struct inode *inode, struct nfs_fattr *fattr)
1246 {
1247 	int status;
1248 
1249 	spin_lock(&inode->i_lock);
1250 	/* Don't do a WCC update if these attributes are already stale */
1251 	if ((fattr->valid & NFS_ATTR_FATTR) == 0 ||
1252 			!nfs_inode_attrs_need_update(inode, fattr)) {
1253 		fattr->valid &= ~(NFS_ATTR_FATTR_PRECHANGE
1254 				| NFS_ATTR_FATTR_PRESIZE
1255 				| NFS_ATTR_FATTR_PREMTIME
1256 				| NFS_ATTR_FATTR_PRECTIME);
1257 		goto out_noforce;
1258 	}
1259 	if ((fattr->valid & NFS_ATTR_FATTR_CHANGE) != 0 &&
1260 			(fattr->valid & NFS_ATTR_FATTR_PRECHANGE) == 0) {
1261 		fattr->pre_change_attr = inode->i_version;
1262 		fattr->valid |= NFS_ATTR_FATTR_PRECHANGE;
1263 	}
1264 	if ((fattr->valid & NFS_ATTR_FATTR_CTIME) != 0 &&
1265 			(fattr->valid & NFS_ATTR_FATTR_PRECTIME) == 0) {
1266 		memcpy(&fattr->pre_ctime, &inode->i_ctime, sizeof(fattr->pre_ctime));
1267 		fattr->valid |= NFS_ATTR_FATTR_PRECTIME;
1268 	}
1269 	if ((fattr->valid & NFS_ATTR_FATTR_MTIME) != 0 &&
1270 			(fattr->valid & NFS_ATTR_FATTR_PREMTIME) == 0) {
1271 		memcpy(&fattr->pre_mtime, &inode->i_mtime, sizeof(fattr->pre_mtime));
1272 		fattr->valid |= NFS_ATTR_FATTR_PREMTIME;
1273 	}
1274 	if ((fattr->valid & NFS_ATTR_FATTR_SIZE) != 0 &&
1275 			(fattr->valid & NFS_ATTR_FATTR_PRESIZE) == 0) {
1276 		fattr->pre_size = i_size_read(inode);
1277 		fattr->valid |= NFS_ATTR_FATTR_PRESIZE;
1278 	}
1279 out_noforce:
1280 	status = nfs_post_op_update_inode_locked(inode, fattr);
1281 	spin_unlock(&inode->i_lock);
1282 	return status;
1283 }
1284 EXPORT_SYMBOL_GPL(nfs_post_op_update_inode_force_wcc);
1285 
1286 /*
1287  * Many nfs protocol calls return the new file attributes after
1288  * an operation.  Here we update the inode to reflect the state
1289  * of the server's inode.
1290  *
1291  * This is a bit tricky because we have to make sure all dirty pages
1292  * have been sent off to the server before calling invalidate_inode_pages.
1293  * To make sure no other process adds more write requests while we try
1294  * our best to flush them, we make them sleep during the attribute refresh.
1295  *
1296  * A very similar scenario holds for the dir cache.
1297  */
1298 static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1299 {
1300 	struct nfs_server *server;
1301 	struct nfs_inode *nfsi = NFS_I(inode);
1302 	loff_t cur_isize, new_isize;
1303 	unsigned long invalid = 0;
1304 	unsigned long now = jiffies;
1305 	unsigned long save_cache_validity;
1306 
1307 	dfprintk(VFS, "NFS: %s(%s/%ld fh_crc=0x%08x ct=%d info=0x%x)\n",
1308 			__func__, inode->i_sb->s_id, inode->i_ino,
1309 			nfs_display_fhandle_hash(NFS_FH(inode)),
1310 			atomic_read(&inode->i_count), fattr->valid);
1311 
1312 	if ((fattr->valid & NFS_ATTR_FATTR_FILEID) && nfsi->fileid != fattr->fileid) {
1313 		printk(KERN_ERR "NFS: server %s error: fileid changed\n"
1314 			"fsid %s: expected fileid 0x%Lx, got 0x%Lx\n",
1315 			NFS_SERVER(inode)->nfs_client->cl_hostname,
1316 			inode->i_sb->s_id, (long long)nfsi->fileid,
1317 			(long long)fattr->fileid);
1318 		goto out_err;
1319 	}
1320 
1321 	/*
1322 	 * Make sure the inode's type hasn't changed.
1323 	 */
1324 	if ((fattr->valid & NFS_ATTR_FATTR_TYPE) && (inode->i_mode & S_IFMT) != (fattr->mode & S_IFMT)) {
1325 		/*
1326 		* Big trouble! The inode has become a different object.
1327 		*/
1328 		printk(KERN_DEBUG "NFS: %s: inode %ld mode changed, %07o to %07o\n",
1329 				__func__, inode->i_ino, inode->i_mode, fattr->mode);
1330 		goto out_err;
1331 	}
1332 
1333 	server = NFS_SERVER(inode);
1334 	/* Update the fsid? */
1335 	if (S_ISDIR(inode->i_mode) && (fattr->valid & NFS_ATTR_FATTR_FSID) &&
1336 			!nfs_fsid_equal(&server->fsid, &fattr->fsid) &&
1337 			!IS_AUTOMOUNT(inode))
1338 		server->fsid = fattr->fsid;
1339 
1340 	/*
1341 	 * Update the read time so we don't revalidate too often.
1342 	 */
1343 	nfsi->read_cache_jiffies = fattr->time_start;
1344 
1345 	save_cache_validity = nfsi->cache_validity;
1346 	nfsi->cache_validity &= ~(NFS_INO_INVALID_ATTR
1347 			| NFS_INO_INVALID_ATIME
1348 			| NFS_INO_REVAL_FORCED
1349 			| NFS_INO_REVAL_PAGECACHE);
1350 
1351 	/* Do atomic weak cache consistency updates */
1352 	invalid |= nfs_wcc_update_inode(inode, fattr);
1353 
1354 	/* More cache consistency checks */
1355 	if (fattr->valid & NFS_ATTR_FATTR_CHANGE) {
1356 		if (inode->i_version != fattr->change_attr) {
1357 			dprintk("NFS: change_attr change on server for file %s/%ld\n",
1358 					inode->i_sb->s_id, inode->i_ino);
1359 			invalid |= NFS_INO_INVALID_ATTR
1360 				| NFS_INO_INVALID_DATA
1361 				| NFS_INO_INVALID_ACCESS
1362 				| NFS_INO_INVALID_ACL
1363 				| NFS_INO_REVAL_PAGECACHE;
1364 			if (S_ISDIR(inode->i_mode))
1365 				nfs_force_lookup_revalidate(inode);
1366 			inode->i_version = fattr->change_attr;
1367 		}
1368 	} else if (server->caps & NFS_CAP_CHANGE_ATTR)
1369 		invalid |= save_cache_validity;
1370 
1371 	if (fattr->valid & NFS_ATTR_FATTR_MTIME) {
1372 		memcpy(&inode->i_mtime, &fattr->mtime, sizeof(inode->i_mtime));
1373 	} else if (server->caps & NFS_CAP_MTIME)
1374 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1375 				| NFS_INO_REVAL_FORCED);
1376 
1377 	if (fattr->valid & NFS_ATTR_FATTR_CTIME) {
1378 		memcpy(&inode->i_ctime, &fattr->ctime, sizeof(inode->i_ctime));
1379 	} else if (server->caps & NFS_CAP_CTIME)
1380 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1381 				| NFS_INO_REVAL_FORCED);
1382 
1383 	/* Check if our cached file size is stale */
1384 	if (fattr->valid & NFS_ATTR_FATTR_SIZE) {
1385 		new_isize = nfs_size_to_loff_t(fattr->size);
1386 		cur_isize = i_size_read(inode);
1387 		if (new_isize != cur_isize) {
1388 			/* Do we perhaps have any outstanding writes, or has
1389 			 * the file grown beyond our last write? */
1390 			if ((nfsi->npages == 0 && !test_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags)) ||
1391 			     new_isize > cur_isize) {
1392 				i_size_write(inode, new_isize);
1393 				invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA;
1394 			}
1395 			dprintk("NFS: isize change on server for file %s/%ld "
1396 					"(%Ld to %Ld)\n",
1397 					inode->i_sb->s_id,
1398 					inode->i_ino,
1399 					(long long)cur_isize,
1400 					(long long)new_isize);
1401 		}
1402 	} else
1403 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1404 				| NFS_INO_REVAL_PAGECACHE
1405 				| NFS_INO_REVAL_FORCED);
1406 
1407 
1408 	if (fattr->valid & NFS_ATTR_FATTR_ATIME)
1409 		memcpy(&inode->i_atime, &fattr->atime, sizeof(inode->i_atime));
1410 	else if (server->caps & NFS_CAP_ATIME)
1411 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATIME
1412 				| NFS_INO_REVAL_FORCED);
1413 
1414 	if (fattr->valid & NFS_ATTR_FATTR_MODE) {
1415 		if ((inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO)) {
1416 			umode_t newmode = inode->i_mode & S_IFMT;
1417 			newmode |= fattr->mode & S_IALLUGO;
1418 			inode->i_mode = newmode;
1419 			invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1420 		}
1421 	} else if (server->caps & NFS_CAP_MODE)
1422 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1423 				| NFS_INO_INVALID_ACCESS
1424 				| NFS_INO_INVALID_ACL
1425 				| NFS_INO_REVAL_FORCED);
1426 
1427 	if (fattr->valid & NFS_ATTR_FATTR_OWNER) {
1428 		if (inode->i_uid != fattr->uid) {
1429 			invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1430 			inode->i_uid = fattr->uid;
1431 		}
1432 	} else if (server->caps & NFS_CAP_OWNER)
1433 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1434 				| NFS_INO_INVALID_ACCESS
1435 				| NFS_INO_INVALID_ACL
1436 				| NFS_INO_REVAL_FORCED);
1437 
1438 	if (fattr->valid & NFS_ATTR_FATTR_GROUP) {
1439 		if (inode->i_gid != fattr->gid) {
1440 			invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1441 			inode->i_gid = fattr->gid;
1442 		}
1443 	} else if (server->caps & NFS_CAP_OWNER_GROUP)
1444 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1445 				| NFS_INO_INVALID_ACCESS
1446 				| NFS_INO_INVALID_ACL
1447 				| NFS_INO_REVAL_FORCED);
1448 
1449 	if (fattr->valid & NFS_ATTR_FATTR_NLINK) {
1450 		if (inode->i_nlink != fattr->nlink) {
1451 			invalid |= NFS_INO_INVALID_ATTR;
1452 			if (S_ISDIR(inode->i_mode))
1453 				invalid |= NFS_INO_INVALID_DATA;
1454 			set_nlink(inode, fattr->nlink);
1455 		}
1456 	} else if (server->caps & NFS_CAP_NLINK)
1457 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1458 				| NFS_INO_REVAL_FORCED);
1459 
1460 	if (fattr->valid & NFS_ATTR_FATTR_SPACE_USED) {
1461 		/*
1462 		 * report the blocks in 512byte units
1463 		 */
1464 		inode->i_blocks = nfs_calc_block_size(fattr->du.nfs3.used);
1465  	}
1466 	if (fattr->valid & NFS_ATTR_FATTR_BLOCKS_USED)
1467 		inode->i_blocks = fattr->du.nfs2.blocks;
1468 
1469 	/* Update attrtimeo value if we're out of the unstable period */
1470 	if (invalid & NFS_INO_INVALID_ATTR) {
1471 		nfs_inc_stats(inode, NFSIOS_ATTRINVALIDATE);
1472 		nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
1473 		nfsi->attrtimeo_timestamp = now;
1474 		nfsi->attr_gencount = nfs_inc_attr_generation_counter();
1475 	} else {
1476 		if (!time_in_range_open(now, nfsi->attrtimeo_timestamp, nfsi->attrtimeo_timestamp + nfsi->attrtimeo)) {
1477 			if ((nfsi->attrtimeo <<= 1) > NFS_MAXATTRTIMEO(inode))
1478 				nfsi->attrtimeo = NFS_MAXATTRTIMEO(inode);
1479 			nfsi->attrtimeo_timestamp = now;
1480 		}
1481 	}
1482 	invalid &= ~NFS_INO_INVALID_ATTR;
1483 	/* Don't invalidate the data if we were to blame */
1484 	if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)
1485 				|| S_ISLNK(inode->i_mode)))
1486 		invalid &= ~NFS_INO_INVALID_DATA;
1487 	if (!NFS_PROTO(inode)->have_delegation(inode, FMODE_READ) ||
1488 			(save_cache_validity & NFS_INO_REVAL_FORCED))
1489 		nfsi->cache_validity |= invalid;
1490 
1491 	return 0;
1492  out_err:
1493 	/*
1494 	 * No need to worry about unhashing the dentry, as the
1495 	 * lookup validation will know that the inode is bad.
1496 	 * (But we fall through to invalidate the caches.)
1497 	 */
1498 	nfs_invalidate_inode(inode);
1499 	return -ESTALE;
1500 }
1501 
1502 struct inode *nfs_alloc_inode(struct super_block *sb)
1503 {
1504 	struct nfs_inode *nfsi;
1505 	nfsi = (struct nfs_inode *)kmem_cache_alloc(nfs_inode_cachep, GFP_KERNEL);
1506 	if (!nfsi)
1507 		return NULL;
1508 	nfsi->flags = 0UL;
1509 	nfsi->cache_validity = 0UL;
1510 #ifdef CONFIG_NFS_V3_ACL
1511 	nfsi->acl_access = ERR_PTR(-EAGAIN);
1512 	nfsi->acl_default = ERR_PTR(-EAGAIN);
1513 #endif
1514 #if IS_ENABLED(CONFIG_NFS_V4)
1515 	nfsi->nfs4_acl = NULL;
1516 #endif /* CONFIG_NFS_V4 */
1517 	return &nfsi->vfs_inode;
1518 }
1519 EXPORT_SYMBOL_GPL(nfs_alloc_inode);
1520 
1521 static void nfs_i_callback(struct rcu_head *head)
1522 {
1523 	struct inode *inode = container_of(head, struct inode, i_rcu);
1524 	kmem_cache_free(nfs_inode_cachep, NFS_I(inode));
1525 }
1526 
1527 void nfs_destroy_inode(struct inode *inode)
1528 {
1529 	call_rcu(&inode->i_rcu, nfs_i_callback);
1530 }
1531 EXPORT_SYMBOL_GPL(nfs_destroy_inode);
1532 
1533 static inline void nfs4_init_once(struct nfs_inode *nfsi)
1534 {
1535 #if IS_ENABLED(CONFIG_NFS_V4)
1536 	INIT_LIST_HEAD(&nfsi->open_states);
1537 	nfsi->delegation = NULL;
1538 	nfsi->delegation_state = 0;
1539 	init_rwsem(&nfsi->rwsem);
1540 	nfsi->layout = NULL;
1541 #endif
1542 }
1543 
1544 static void init_once(void *foo)
1545 {
1546 	struct nfs_inode *nfsi = (struct nfs_inode *) foo;
1547 
1548 	inode_init_once(&nfsi->vfs_inode);
1549 	INIT_LIST_HEAD(&nfsi->open_files);
1550 	INIT_LIST_HEAD(&nfsi->access_cache_entry_lru);
1551 	INIT_LIST_HEAD(&nfsi->access_cache_inode_lru);
1552 	INIT_LIST_HEAD(&nfsi->commit_info.list);
1553 	nfsi->npages = 0;
1554 	nfsi->commit_info.ncommit = 0;
1555 	atomic_set(&nfsi->commit_info.rpcs_out, 0);
1556 	atomic_set(&nfsi->silly_count, 1);
1557 	INIT_HLIST_HEAD(&nfsi->silly_list);
1558 	init_waitqueue_head(&nfsi->waitqueue);
1559 	nfs4_init_once(nfsi);
1560 }
1561 
1562 static int __init nfs_init_inodecache(void)
1563 {
1564 	nfs_inode_cachep = kmem_cache_create("nfs_inode_cache",
1565 					     sizeof(struct nfs_inode),
1566 					     0, (SLAB_RECLAIM_ACCOUNT|
1567 						SLAB_MEM_SPREAD),
1568 					     init_once);
1569 	if (nfs_inode_cachep == NULL)
1570 		return -ENOMEM;
1571 
1572 	return 0;
1573 }
1574 
1575 static void nfs_destroy_inodecache(void)
1576 {
1577 	/*
1578 	 * Make sure all delayed rcu free inodes are flushed before we
1579 	 * destroy cache.
1580 	 */
1581 	rcu_barrier();
1582 	kmem_cache_destroy(nfs_inode_cachep);
1583 }
1584 
1585 struct workqueue_struct *nfsiod_workqueue;
1586 EXPORT_SYMBOL_GPL(nfsiod_workqueue);
1587 
1588 /*
1589  * start up the nfsiod workqueue
1590  */
1591 static int nfsiod_start(void)
1592 {
1593 	struct workqueue_struct *wq;
1594 	dprintk("RPC:       creating workqueue nfsiod\n");
1595 	wq = alloc_workqueue("nfsiod", WQ_MEM_RECLAIM, 0);
1596 	if (wq == NULL)
1597 		return -ENOMEM;
1598 	nfsiod_workqueue = wq;
1599 	return 0;
1600 }
1601 
1602 /*
1603  * Destroy the nfsiod workqueue
1604  */
1605 static void nfsiod_stop(void)
1606 {
1607 	struct workqueue_struct *wq;
1608 
1609 	wq = nfsiod_workqueue;
1610 	if (wq == NULL)
1611 		return;
1612 	nfsiod_workqueue = NULL;
1613 	destroy_workqueue(wq);
1614 }
1615 
1616 int nfs_net_id;
1617 EXPORT_SYMBOL_GPL(nfs_net_id);
1618 
1619 static int nfs_net_init(struct net *net)
1620 {
1621 	nfs_clients_init(net);
1622 	return nfs_dns_resolver_cache_init(net);
1623 }
1624 
1625 static void nfs_net_exit(struct net *net)
1626 {
1627 	nfs_dns_resolver_cache_destroy(net);
1628 	nfs_cleanup_cb_ident_idr(net);
1629 }
1630 
1631 static struct pernet_operations nfs_net_ops = {
1632 	.init = nfs_net_init,
1633 	.exit = nfs_net_exit,
1634 	.id   = &nfs_net_id,
1635 	.size = sizeof(struct nfs_net),
1636 };
1637 
1638 /*
1639  * Initialize NFS
1640  */
1641 static int __init init_nfs_fs(void)
1642 {
1643 	int err;
1644 
1645 	err = nfs_dns_resolver_init();
1646 	if (err < 0)
1647 		goto out10;;
1648 
1649 	err = register_pernet_subsys(&nfs_net_ops);
1650 	if (err < 0)
1651 		goto out9;
1652 
1653 	err = nfs_fscache_register();
1654 	if (err < 0)
1655 		goto out8;
1656 
1657 	err = nfsiod_start();
1658 	if (err)
1659 		goto out7;
1660 
1661 	err = nfs_fs_proc_init();
1662 	if (err)
1663 		goto out6;
1664 
1665 	err = nfs_init_nfspagecache();
1666 	if (err)
1667 		goto out5;
1668 
1669 	err = nfs_init_inodecache();
1670 	if (err)
1671 		goto out4;
1672 
1673 	err = nfs_init_readpagecache();
1674 	if (err)
1675 		goto out3;
1676 
1677 	err = nfs_init_writepagecache();
1678 	if (err)
1679 		goto out2;
1680 
1681 	err = nfs_init_directcache();
1682 	if (err)
1683 		goto out1;
1684 
1685 #ifdef CONFIG_PROC_FS
1686 	rpc_proc_register(&init_net, &nfs_rpcstat);
1687 #endif
1688 	if ((err = register_nfs_fs()) != 0)
1689 		goto out0;
1690 
1691 	return 0;
1692 out0:
1693 #ifdef CONFIG_PROC_FS
1694 	rpc_proc_unregister(&init_net, "nfs");
1695 #endif
1696 	nfs_destroy_directcache();
1697 out1:
1698 	nfs_destroy_writepagecache();
1699 out2:
1700 	nfs_destroy_readpagecache();
1701 out3:
1702 	nfs_destroy_inodecache();
1703 out4:
1704 	nfs_destroy_nfspagecache();
1705 out5:
1706 	nfs_fs_proc_exit();
1707 out6:
1708 	nfsiod_stop();
1709 out7:
1710 	nfs_fscache_unregister();
1711 out8:
1712 	unregister_pernet_subsys(&nfs_net_ops);
1713 out9:
1714 	nfs_dns_resolver_destroy();
1715 out10:
1716 	return err;
1717 }
1718 
1719 static void __exit exit_nfs_fs(void)
1720 {
1721 	nfs_destroy_directcache();
1722 	nfs_destroy_writepagecache();
1723 	nfs_destroy_readpagecache();
1724 	nfs_destroy_inodecache();
1725 	nfs_destroy_nfspagecache();
1726 	nfs_fscache_unregister();
1727 	unregister_pernet_subsys(&nfs_net_ops);
1728 	nfs_dns_resolver_destroy();
1729 #ifdef CONFIG_PROC_FS
1730 	rpc_proc_unregister(&init_net, "nfs");
1731 #endif
1732 	unregister_nfs_fs();
1733 	nfs_fs_proc_exit();
1734 	nfsiod_stop();
1735 }
1736 
1737 /* Not quite true; I just maintain it */
1738 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
1739 MODULE_LICENSE("GPL");
1740 module_param(enable_ino64, bool, 0644);
1741 
1742 module_init(init_nfs_fs)
1743 module_exit(exit_nfs_fs)
1744