xref: /linux/fs/nfs/inode.c (revision 615f2e5c531bc57d5a190f321d697988e950ae4d)
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 int nfs_drop_inode(struct inode *inode)
111 {
112 	return NFS_STALE(inode) || generic_drop_inode(inode);
113 }
114 EXPORT_SYMBOL_GPL(nfs_drop_inode);
115 
116 void nfs_clear_inode(struct inode *inode)
117 {
118 	/*
119 	 * The following should never happen...
120 	 */
121 	WARN_ON_ONCE(nfs_have_writebacks(inode));
122 	WARN_ON_ONCE(!list_empty(&NFS_I(inode)->open_files));
123 	nfs_zap_acl_cache(inode);
124 	nfs_access_zap_cache(inode);
125 	nfs_fscache_release_inode_cookie(inode);
126 }
127 EXPORT_SYMBOL_GPL(nfs_clear_inode);
128 
129 void nfs_evict_inode(struct inode *inode)
130 {
131 	truncate_inode_pages(&inode->i_data, 0);
132 	clear_inode(inode);
133 	nfs_clear_inode(inode);
134 }
135 
136 /**
137  * nfs_sync_mapping - helper to flush all mmapped dirty data to disk
138  */
139 int nfs_sync_mapping(struct address_space *mapping)
140 {
141 	int ret = 0;
142 
143 	if (mapping->nrpages != 0) {
144 		unmap_mapping_range(mapping, 0, 0, 0);
145 		ret = nfs_wb_all(mapping->host);
146 	}
147 	return ret;
148 }
149 
150 /*
151  * Invalidate the local caches
152  */
153 static void nfs_zap_caches_locked(struct inode *inode)
154 {
155 	struct nfs_inode *nfsi = NFS_I(inode);
156 	int mode = inode->i_mode;
157 
158 	nfs_inc_stats(inode, NFSIOS_ATTRINVALIDATE);
159 
160 	nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
161 	nfsi->attrtimeo_timestamp = jiffies;
162 
163 	memset(NFS_I(inode)->cookieverf, 0, sizeof(NFS_I(inode)->cookieverf));
164 	if (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)) {
165 		nfsi->cache_validity |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL|NFS_INO_REVAL_PAGECACHE;
166 		nfs_fscache_invalidate(inode);
167 	} else {
168 		nfsi->cache_validity |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL|NFS_INO_REVAL_PAGECACHE;
169 	}
170 }
171 
172 void nfs_zap_caches(struct inode *inode)
173 {
174 	spin_lock(&inode->i_lock);
175 	nfs_zap_caches_locked(inode);
176 	spin_unlock(&inode->i_lock);
177 }
178 
179 void nfs_zap_mapping(struct inode *inode, struct address_space *mapping)
180 {
181 	if (mapping->nrpages != 0) {
182 		spin_lock(&inode->i_lock);
183 		NFS_I(inode)->cache_validity |= NFS_INO_INVALID_DATA;
184 		nfs_fscache_invalidate(inode);
185 		spin_unlock(&inode->i_lock);
186 	}
187 }
188 
189 void nfs_zap_acl_cache(struct inode *inode)
190 {
191 	void (*clear_acl_cache)(struct inode *);
192 
193 	clear_acl_cache = NFS_PROTO(inode)->clear_acl_cache;
194 	if (clear_acl_cache != NULL)
195 		clear_acl_cache(inode);
196 	spin_lock(&inode->i_lock);
197 	NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_ACL;
198 	spin_unlock(&inode->i_lock);
199 }
200 EXPORT_SYMBOL_GPL(nfs_zap_acl_cache);
201 
202 void nfs_invalidate_atime(struct inode *inode)
203 {
204 	spin_lock(&inode->i_lock);
205 	NFS_I(inode)->cache_validity |= NFS_INO_INVALID_ATIME;
206 	spin_unlock(&inode->i_lock);
207 }
208 EXPORT_SYMBOL_GPL(nfs_invalidate_atime);
209 
210 /*
211  * Invalidate, but do not unhash, the inode.
212  * NB: must be called with inode->i_lock held!
213  */
214 static void nfs_invalidate_inode(struct inode *inode)
215 {
216 	set_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
217 	nfs_zap_caches_locked(inode);
218 }
219 
220 struct nfs_find_desc {
221 	struct nfs_fh		*fh;
222 	struct nfs_fattr	*fattr;
223 };
224 
225 /*
226  * In NFSv3 we can have 64bit inode numbers. In order to support
227  * this, and re-exported directories (also seen in NFSv2)
228  * we are forced to allow 2 different inodes to have the same
229  * i_ino.
230  */
231 static int
232 nfs_find_actor(struct inode *inode, void *opaque)
233 {
234 	struct nfs_find_desc	*desc = (struct nfs_find_desc *)opaque;
235 	struct nfs_fh		*fh = desc->fh;
236 	struct nfs_fattr	*fattr = desc->fattr;
237 
238 	if (NFS_FILEID(inode) != fattr->fileid)
239 		return 0;
240 	if (nfs_compare_fh(NFS_FH(inode), fh))
241 		return 0;
242 	if (is_bad_inode(inode) || NFS_STALE(inode))
243 		return 0;
244 	return 1;
245 }
246 
247 static int
248 nfs_init_locked(struct inode *inode, void *opaque)
249 {
250 	struct nfs_find_desc	*desc = (struct nfs_find_desc *)opaque;
251 	struct nfs_fattr	*fattr = desc->fattr;
252 
253 	set_nfs_fileid(inode, fattr->fileid);
254 	nfs_copy_fh(NFS_FH(inode), desc->fh);
255 	return 0;
256 }
257 
258 /*
259  * This is our front-end to iget that looks up inodes by file handle
260  * instead of inode number.
261  */
262 struct inode *
263 nfs_fhget(struct super_block *sb, struct nfs_fh *fh, struct nfs_fattr *fattr)
264 {
265 	struct nfs_find_desc desc = {
266 		.fh	= fh,
267 		.fattr	= fattr
268 	};
269 	struct inode *inode = ERR_PTR(-ENOENT);
270 	unsigned long hash;
271 
272 	nfs_attr_check_mountpoint(sb, fattr);
273 
274 	if (((fattr->valid & NFS_ATTR_FATTR_FILEID) == 0) &&
275 	    !nfs_attr_use_mounted_on_fileid(fattr))
276 		goto out_no_inode;
277 	if ((fattr->valid & NFS_ATTR_FATTR_TYPE) == 0)
278 		goto out_no_inode;
279 
280 	hash = nfs_fattr_to_ino_t(fattr);
281 
282 	inode = iget5_locked(sb, hash, nfs_find_actor, nfs_init_locked, &desc);
283 	if (inode == NULL) {
284 		inode = ERR_PTR(-ENOMEM);
285 		goto out_no_inode;
286 	}
287 
288 	if (inode->i_state & I_NEW) {
289 		struct nfs_inode *nfsi = NFS_I(inode);
290 		unsigned long now = jiffies;
291 
292 		/* We set i_ino for the few things that still rely on it,
293 		 * such as stat(2) */
294 		inode->i_ino = hash;
295 
296 		/* We can't support update_atime(), since the server will reset it */
297 		inode->i_flags |= S_NOATIME|S_NOCMTIME;
298 		inode->i_mode = fattr->mode;
299 		if ((fattr->valid & NFS_ATTR_FATTR_MODE) == 0
300 				&& nfs_server_capable(inode, NFS_CAP_MODE))
301 			nfsi->cache_validity |= NFS_INO_INVALID_ATTR;
302 		/* Why so? Because we want revalidate for devices/FIFOs, and
303 		 * that's precisely what we have in nfs_file_inode_operations.
304 		 */
305 		inode->i_op = NFS_SB(sb)->nfs_client->rpc_ops->file_inode_ops;
306 		if (S_ISREG(inode->i_mode)) {
307 			inode->i_fop = NFS_SB(sb)->nfs_client->rpc_ops->file_ops;
308 			inode->i_data.a_ops = &nfs_file_aops;
309 			inode->i_data.backing_dev_info = &NFS_SB(sb)->backing_dev_info;
310 		} else if (S_ISDIR(inode->i_mode)) {
311 			inode->i_op = NFS_SB(sb)->nfs_client->rpc_ops->dir_inode_ops;
312 			inode->i_fop = &nfs_dir_operations;
313 			inode->i_data.a_ops = &nfs_dir_aops;
314 			/* Deal with crossing mountpoints */
315 			if (fattr->valid & NFS_ATTR_FATTR_MOUNTPOINT ||
316 					fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL) {
317 				if (fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL)
318 					inode->i_op = &nfs_referral_inode_operations;
319 				else
320 					inode->i_op = &nfs_mountpoint_inode_operations;
321 				inode->i_fop = NULL;
322 				inode->i_flags |= S_AUTOMOUNT;
323 			}
324 		} else if (S_ISLNK(inode->i_mode))
325 			inode->i_op = &nfs_symlink_inode_operations;
326 		else
327 			init_special_inode(inode, inode->i_mode, fattr->rdev);
328 
329 		memset(&inode->i_atime, 0, sizeof(inode->i_atime));
330 		memset(&inode->i_mtime, 0, sizeof(inode->i_mtime));
331 		memset(&inode->i_ctime, 0, sizeof(inode->i_ctime));
332 		inode->i_version = 0;
333 		inode->i_size = 0;
334 		clear_nlink(inode);
335 		inode->i_uid = make_kuid(&init_user_ns, -2);
336 		inode->i_gid = make_kgid(&init_user_ns, -2);
337 		inode->i_blocks = 0;
338 		memset(nfsi->cookieverf, 0, sizeof(nfsi->cookieverf));
339 		nfsi->write_io = 0;
340 		nfsi->read_io = 0;
341 
342 		nfsi->read_cache_jiffies = fattr->time_start;
343 		nfsi->attr_gencount = fattr->gencount;
344 		if (fattr->valid & NFS_ATTR_FATTR_ATIME)
345 			inode->i_atime = fattr->atime;
346 		else if (nfs_server_capable(inode, NFS_CAP_ATIME))
347 			nfsi->cache_validity |= NFS_INO_INVALID_ATTR;
348 		if (fattr->valid & NFS_ATTR_FATTR_MTIME)
349 			inode->i_mtime = fattr->mtime;
350 		else if (nfs_server_capable(inode, NFS_CAP_MTIME))
351 			nfsi->cache_validity |= NFS_INO_INVALID_ATTR;
352 		if (fattr->valid & NFS_ATTR_FATTR_CTIME)
353 			inode->i_ctime = fattr->ctime;
354 		else if (nfs_server_capable(inode, NFS_CAP_CTIME))
355 			nfsi->cache_validity |= NFS_INO_INVALID_ATTR;
356 		if (fattr->valid & NFS_ATTR_FATTR_CHANGE)
357 			inode->i_version = fattr->change_attr;
358 		else if (nfs_server_capable(inode, NFS_CAP_CHANGE_ATTR))
359 			nfsi->cache_validity |= NFS_INO_INVALID_ATTR;
360 		if (fattr->valid & NFS_ATTR_FATTR_SIZE)
361 			inode->i_size = nfs_size_to_loff_t(fattr->size);
362 		else
363 			nfsi->cache_validity |= NFS_INO_INVALID_ATTR
364 				| NFS_INO_REVAL_PAGECACHE;
365 		if (fattr->valid & NFS_ATTR_FATTR_NLINK)
366 			set_nlink(inode, fattr->nlink);
367 		else if (nfs_server_capable(inode, NFS_CAP_NLINK))
368 			nfsi->cache_validity |= NFS_INO_INVALID_ATTR;
369 		if (fattr->valid & NFS_ATTR_FATTR_OWNER)
370 			inode->i_uid = fattr->uid;
371 		else if (nfs_server_capable(inode, NFS_CAP_OWNER))
372 			nfsi->cache_validity |= NFS_INO_INVALID_ATTR;
373 		if (fattr->valid & NFS_ATTR_FATTR_GROUP)
374 			inode->i_gid = fattr->gid;
375 		else if (nfs_server_capable(inode, NFS_CAP_OWNER_GROUP))
376 			nfsi->cache_validity |= NFS_INO_INVALID_ATTR;
377 		if (fattr->valid & NFS_ATTR_FATTR_BLOCKS_USED)
378 			inode->i_blocks = fattr->du.nfs2.blocks;
379 		if (fattr->valid & NFS_ATTR_FATTR_SPACE_USED) {
380 			/*
381 			 * report the blocks in 512byte units
382 			 */
383 			inode->i_blocks = nfs_calc_block_size(fattr->du.nfs3.used);
384 		}
385 		nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
386 		nfsi->attrtimeo_timestamp = now;
387 		nfsi->access_cache = RB_ROOT;
388 
389 		nfs_fscache_init_inode_cookie(inode);
390 
391 		unlock_new_inode(inode);
392 	} else
393 		nfs_refresh_inode(inode, fattr);
394 	dprintk("NFS: nfs_fhget(%s/%Ld fh_crc=0x%08x ct=%d)\n",
395 		inode->i_sb->s_id,
396 		(long long)NFS_FILEID(inode),
397 		nfs_display_fhandle_hash(fh),
398 		atomic_read(&inode->i_count));
399 
400 out:
401 	return inode;
402 
403 out_no_inode:
404 	dprintk("nfs_fhget: iget failed with error %ld\n", PTR_ERR(inode));
405 	goto out;
406 }
407 EXPORT_SYMBOL_GPL(nfs_fhget);
408 
409 #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)
410 
411 int
412 nfs_setattr(struct dentry *dentry, struct iattr *attr)
413 {
414 	struct inode *inode = dentry->d_inode;
415 	struct nfs_fattr *fattr;
416 	int error = -ENOMEM;
417 
418 	nfs_inc_stats(inode, NFSIOS_VFSSETATTR);
419 
420 	/* skip mode change if it's just for clearing setuid/setgid */
421 	if (attr->ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
422 		attr->ia_valid &= ~ATTR_MODE;
423 
424 	if (attr->ia_valid & ATTR_SIZE) {
425 		if (!S_ISREG(inode->i_mode) || attr->ia_size == i_size_read(inode))
426 			attr->ia_valid &= ~ATTR_SIZE;
427 	}
428 
429 	/* Optimization: if the end result is no change, don't RPC */
430 	attr->ia_valid &= NFS_VALID_ATTRS;
431 	if ((attr->ia_valid & ~(ATTR_FILE|ATTR_OPEN)) == 0)
432 		return 0;
433 
434 	/* Write all dirty data */
435 	if (S_ISREG(inode->i_mode)) {
436 		nfs_inode_dio_wait(inode);
437 		nfs_wb_all(inode);
438 	}
439 
440 	fattr = nfs_alloc_fattr();
441 	if (fattr == NULL)
442 		goto out;
443 	/*
444 	 * Return any delegations if we're going to change ACLs
445 	 */
446 	if ((attr->ia_valid & (ATTR_MODE|ATTR_UID|ATTR_GID)) != 0)
447 		NFS_PROTO(inode)->return_delegation(inode);
448 	error = NFS_PROTO(inode)->setattr(dentry, fattr, attr);
449 	if (error == 0)
450 		nfs_refresh_inode(inode, fattr);
451 	nfs_free_fattr(fattr);
452 out:
453 	return error;
454 }
455 EXPORT_SYMBOL_GPL(nfs_setattr);
456 
457 /**
458  * nfs_vmtruncate - unmap mappings "freed" by truncate() syscall
459  * @inode: inode of the file used
460  * @offset: file offset to start truncating
461  *
462  * This is a copy of the common vmtruncate, but with the locking
463  * corrected to take into account the fact that NFS requires
464  * inode->i_size to be updated under the inode->i_lock.
465  */
466 static int nfs_vmtruncate(struct inode * inode, loff_t offset)
467 {
468 	loff_t oldsize;
469 	int err;
470 
471 	err = inode_newsize_ok(inode, offset);
472 	if (err)
473 		goto out;
474 
475 	spin_lock(&inode->i_lock);
476 	oldsize = inode->i_size;
477 	i_size_write(inode, offset);
478 	spin_unlock(&inode->i_lock);
479 
480 	truncate_pagecache(inode, oldsize, offset);
481 out:
482 	return err;
483 }
484 
485 /**
486  * nfs_setattr_update_inode - Update inode metadata after a setattr call.
487  * @inode: pointer to struct inode
488  * @attr: pointer to struct iattr
489  *
490  * Note: we do this in the *proc.c in order to ensure that
491  *       it works for things like exclusive creates too.
492  */
493 void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr)
494 {
495 	if ((attr->ia_valid & (ATTR_MODE|ATTR_UID|ATTR_GID)) != 0) {
496 		spin_lock(&inode->i_lock);
497 		if ((attr->ia_valid & ATTR_MODE) != 0) {
498 			int mode = attr->ia_mode & S_IALLUGO;
499 			mode |= inode->i_mode & ~S_IALLUGO;
500 			inode->i_mode = mode;
501 		}
502 		if ((attr->ia_valid & ATTR_UID) != 0)
503 			inode->i_uid = attr->ia_uid;
504 		if ((attr->ia_valid & ATTR_GID) != 0)
505 			inode->i_gid = attr->ia_gid;
506 		NFS_I(inode)->cache_validity |= NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
507 		spin_unlock(&inode->i_lock);
508 	}
509 	if ((attr->ia_valid & ATTR_SIZE) != 0) {
510 		nfs_inc_stats(inode, NFSIOS_SETATTRTRUNC);
511 		nfs_vmtruncate(inode, attr->ia_size);
512 	}
513 }
514 EXPORT_SYMBOL_GPL(nfs_setattr_update_inode);
515 
516 int nfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
517 {
518 	struct inode *inode = dentry->d_inode;
519 	int need_atime = NFS_I(inode)->cache_validity & NFS_INO_INVALID_ATIME;
520 	int err;
521 
522 	/* Flush out writes to the server in order to update c/mtime.  */
523 	if (S_ISREG(inode->i_mode)) {
524 		nfs_inode_dio_wait(inode);
525 		err = filemap_write_and_wait(inode->i_mapping);
526 		if (err)
527 			goto out;
528 	}
529 
530 	/*
531 	 * We may force a getattr if the user cares about atime.
532 	 *
533 	 * Note that we only have to check the vfsmount flags here:
534 	 *  - NFS always sets S_NOATIME by so checking it would give a
535 	 *    bogus result
536 	 *  - NFS never sets MS_NOATIME or MS_NODIRATIME so there is
537 	 *    no point in checking those.
538 	 */
539  	if ((mnt->mnt_flags & MNT_NOATIME) ||
540  	    ((mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode)))
541 		need_atime = 0;
542 
543 	if (need_atime)
544 		err = __nfs_revalidate_inode(NFS_SERVER(inode), inode);
545 	else
546 		err = nfs_revalidate_inode(NFS_SERVER(inode), inode);
547 	if (!err) {
548 		generic_fillattr(inode, stat);
549 		stat->ino = nfs_compat_user_ino64(NFS_FILEID(inode));
550 	}
551 out:
552 	return err;
553 }
554 EXPORT_SYMBOL_GPL(nfs_getattr);
555 
556 static void nfs_init_lock_context(struct nfs_lock_context *l_ctx)
557 {
558 	atomic_set(&l_ctx->count, 1);
559 	l_ctx->lockowner.l_owner = current->files;
560 	l_ctx->lockowner.l_pid = current->tgid;
561 	INIT_LIST_HEAD(&l_ctx->list);
562 }
563 
564 static struct nfs_lock_context *__nfs_find_lock_context(struct nfs_open_context *ctx)
565 {
566 	struct nfs_lock_context *pos;
567 
568 	list_for_each_entry(pos, &ctx->lock_context.list, list) {
569 		if (pos->lockowner.l_owner != current->files)
570 			continue;
571 		if (pos->lockowner.l_pid != current->tgid)
572 			continue;
573 		atomic_inc(&pos->count);
574 		return pos;
575 	}
576 	return NULL;
577 }
578 
579 struct nfs_lock_context *nfs_get_lock_context(struct nfs_open_context *ctx)
580 {
581 	struct nfs_lock_context *res, *new = NULL;
582 	struct inode *inode = ctx->dentry->d_inode;
583 
584 	spin_lock(&inode->i_lock);
585 	res = __nfs_find_lock_context(ctx);
586 	if (res == NULL) {
587 		spin_unlock(&inode->i_lock);
588 		new = kmalloc(sizeof(*new), GFP_KERNEL);
589 		if (new == NULL)
590 			return ERR_PTR(-ENOMEM);
591 		nfs_init_lock_context(new);
592 		spin_lock(&inode->i_lock);
593 		res = __nfs_find_lock_context(ctx);
594 		if (res == NULL) {
595 			list_add_tail(&new->list, &ctx->lock_context.list);
596 			new->open_context = ctx;
597 			res = new;
598 			new = NULL;
599 		}
600 	}
601 	spin_unlock(&inode->i_lock);
602 	kfree(new);
603 	return res;
604 }
605 
606 void nfs_put_lock_context(struct nfs_lock_context *l_ctx)
607 {
608 	struct nfs_open_context *ctx = l_ctx->open_context;
609 	struct inode *inode = ctx->dentry->d_inode;
610 
611 	if (!atomic_dec_and_lock(&l_ctx->count, &inode->i_lock))
612 		return;
613 	list_del(&l_ctx->list);
614 	spin_unlock(&inode->i_lock);
615 	kfree(l_ctx);
616 }
617 
618 /**
619  * nfs_close_context - Common close_context() routine NFSv2/v3
620  * @ctx: pointer to context
621  * @is_sync: is this a synchronous close
622  *
623  * always ensure that the attributes are up to date if we're mounted
624  * with close-to-open semantics
625  */
626 void nfs_close_context(struct nfs_open_context *ctx, int is_sync)
627 {
628 	struct inode *inode;
629 	struct nfs_server *server;
630 
631 	if (!(ctx->mode & FMODE_WRITE))
632 		return;
633 	if (!is_sync)
634 		return;
635 	inode = ctx->dentry->d_inode;
636 	if (!list_empty(&NFS_I(inode)->open_files))
637 		return;
638 	server = NFS_SERVER(inode);
639 	if (server->flags & NFS_MOUNT_NOCTO)
640 		return;
641 	nfs_revalidate_inode(server, inode);
642 }
643 EXPORT_SYMBOL_GPL(nfs_close_context);
644 
645 struct nfs_open_context *alloc_nfs_open_context(struct dentry *dentry, fmode_t f_mode)
646 {
647 	struct nfs_open_context *ctx;
648 	struct rpc_cred *cred = rpc_lookup_cred();
649 	if (IS_ERR(cred))
650 		return ERR_CAST(cred);
651 
652 	ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
653 	if (!ctx) {
654 		put_rpccred(cred);
655 		return ERR_PTR(-ENOMEM);
656 	}
657 	nfs_sb_active(dentry->d_sb);
658 	ctx->dentry = dget(dentry);
659 	ctx->cred = cred;
660 	ctx->state = NULL;
661 	ctx->mode = f_mode;
662 	ctx->flags = 0;
663 	ctx->error = 0;
664 	nfs_init_lock_context(&ctx->lock_context);
665 	ctx->lock_context.open_context = ctx;
666 	INIT_LIST_HEAD(&ctx->list);
667 	ctx->mdsthreshold = NULL;
668 	return ctx;
669 }
670 EXPORT_SYMBOL_GPL(alloc_nfs_open_context);
671 
672 struct nfs_open_context *get_nfs_open_context(struct nfs_open_context *ctx)
673 {
674 	if (ctx != NULL)
675 		atomic_inc(&ctx->lock_context.count);
676 	return ctx;
677 }
678 EXPORT_SYMBOL_GPL(get_nfs_open_context);
679 
680 static void __put_nfs_open_context(struct nfs_open_context *ctx, int is_sync)
681 {
682 	struct inode *inode = ctx->dentry->d_inode;
683 	struct super_block *sb = ctx->dentry->d_sb;
684 
685 	if (!list_empty(&ctx->list)) {
686 		if (!atomic_dec_and_lock(&ctx->lock_context.count, &inode->i_lock))
687 			return;
688 		list_del(&ctx->list);
689 		spin_unlock(&inode->i_lock);
690 	} else if (!atomic_dec_and_test(&ctx->lock_context.count))
691 		return;
692 	if (inode != NULL)
693 		NFS_PROTO(inode)->close_context(ctx, is_sync);
694 	if (ctx->cred != NULL)
695 		put_rpccred(ctx->cred);
696 	dput(ctx->dentry);
697 	nfs_sb_deactive(sb);
698 	kfree(ctx->mdsthreshold);
699 	kfree(ctx);
700 }
701 
702 void put_nfs_open_context(struct nfs_open_context *ctx)
703 {
704 	__put_nfs_open_context(ctx, 0);
705 }
706 EXPORT_SYMBOL_GPL(put_nfs_open_context);
707 
708 /*
709  * Ensure that mmap has a recent RPC credential for use when writing out
710  * shared pages
711  */
712 void nfs_file_set_open_context(struct file *filp, struct nfs_open_context *ctx)
713 {
714 	struct inode *inode = file_inode(filp);
715 	struct nfs_inode *nfsi = NFS_I(inode);
716 
717 	filp->private_data = get_nfs_open_context(ctx);
718 	spin_lock(&inode->i_lock);
719 	list_add(&ctx->list, &nfsi->open_files);
720 	spin_unlock(&inode->i_lock);
721 }
722 EXPORT_SYMBOL_GPL(nfs_file_set_open_context);
723 
724 /*
725  * Given an inode, search for an open context with the desired characteristics
726  */
727 struct nfs_open_context *nfs_find_open_context(struct inode *inode, struct rpc_cred *cred, fmode_t mode)
728 {
729 	struct nfs_inode *nfsi = NFS_I(inode);
730 	struct nfs_open_context *pos, *ctx = NULL;
731 
732 	spin_lock(&inode->i_lock);
733 	list_for_each_entry(pos, &nfsi->open_files, list) {
734 		if (cred != NULL && pos->cred != cred)
735 			continue;
736 		if ((pos->mode & (FMODE_READ|FMODE_WRITE)) != mode)
737 			continue;
738 		ctx = get_nfs_open_context(pos);
739 		break;
740 	}
741 	spin_unlock(&inode->i_lock);
742 	return ctx;
743 }
744 
745 static void nfs_file_clear_open_context(struct file *filp)
746 {
747 	struct inode *inode = file_inode(filp);
748 	struct nfs_open_context *ctx = nfs_file_open_context(filp);
749 
750 	if (ctx) {
751 		filp->private_data = NULL;
752 		spin_lock(&inode->i_lock);
753 		list_move_tail(&ctx->list, &NFS_I(inode)->open_files);
754 		spin_unlock(&inode->i_lock);
755 		__put_nfs_open_context(ctx, filp->f_flags & O_DIRECT ? 0 : 1);
756 	}
757 }
758 
759 /*
760  * These allocate and release file read/write context information.
761  */
762 int nfs_open(struct inode *inode, struct file *filp)
763 {
764 	struct nfs_open_context *ctx;
765 
766 	ctx = alloc_nfs_open_context(filp->f_path.dentry, filp->f_mode);
767 	if (IS_ERR(ctx))
768 		return PTR_ERR(ctx);
769 	nfs_file_set_open_context(filp, ctx);
770 	put_nfs_open_context(ctx);
771 	nfs_fscache_set_inode_cookie(inode, filp);
772 	return 0;
773 }
774 
775 int nfs_release(struct inode *inode, struct file *filp)
776 {
777 	nfs_file_clear_open_context(filp);
778 	return 0;
779 }
780 
781 /*
782  * This function is called whenever some part of NFS notices that
783  * the cached attributes have to be refreshed.
784  */
785 int
786 __nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
787 {
788 	int		 status = -ESTALE;
789 	struct nfs_fattr *fattr = NULL;
790 	struct nfs_inode *nfsi = NFS_I(inode);
791 
792 	dfprintk(PAGECACHE, "NFS: revalidating (%s/%Ld)\n",
793 		inode->i_sb->s_id, (long long)NFS_FILEID(inode));
794 
795 	if (is_bad_inode(inode))
796 		goto out;
797 	if (NFS_STALE(inode))
798 		goto out;
799 
800 	status = -ENOMEM;
801 	fattr = nfs_alloc_fattr();
802 	if (fattr == NULL)
803 		goto out;
804 
805 	nfs_inc_stats(inode, NFSIOS_INODEREVALIDATE);
806 	status = NFS_PROTO(inode)->getattr(server, NFS_FH(inode), fattr);
807 	if (status != 0) {
808 		dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Ld) getattr failed, error=%d\n",
809 			 inode->i_sb->s_id,
810 			 (long long)NFS_FILEID(inode), status);
811 		if (status == -ESTALE) {
812 			nfs_zap_caches(inode);
813 			if (!S_ISDIR(inode->i_mode))
814 				set_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
815 		}
816 		goto out;
817 	}
818 
819 	status = nfs_refresh_inode(inode, fattr);
820 	if (status) {
821 		dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Ld) refresh failed, error=%d\n",
822 			 inode->i_sb->s_id,
823 			 (long long)NFS_FILEID(inode), status);
824 		goto out;
825 	}
826 
827 	if (nfsi->cache_validity & NFS_INO_INVALID_ACL)
828 		nfs_zap_acl_cache(inode);
829 
830 	dfprintk(PAGECACHE, "NFS: (%s/%Ld) revalidation complete\n",
831 		inode->i_sb->s_id,
832 		(long long)NFS_FILEID(inode));
833 
834  out:
835 	nfs_free_fattr(fattr);
836 	return status;
837 }
838 
839 int nfs_attribute_timeout(struct inode *inode)
840 {
841 	struct nfs_inode *nfsi = NFS_I(inode);
842 
843 	return !time_in_range_open(jiffies, nfsi->read_cache_jiffies, nfsi->read_cache_jiffies + nfsi->attrtimeo);
844 }
845 
846 static int nfs_attribute_cache_expired(struct inode *inode)
847 {
848 	if (nfs_have_delegated_attributes(inode))
849 		return 0;
850 	return nfs_attribute_timeout(inode);
851 }
852 
853 /**
854  * nfs_revalidate_inode - Revalidate the inode attributes
855  * @server - pointer to nfs_server struct
856  * @inode - pointer to inode struct
857  *
858  * Updates inode attribute information by retrieving the data from the server.
859  */
860 int nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
861 {
862 	if (!(NFS_I(inode)->cache_validity & NFS_INO_INVALID_ATTR)
863 			&& !nfs_attribute_cache_expired(inode))
864 		return NFS_STALE(inode) ? -ESTALE : 0;
865 	return __nfs_revalidate_inode(server, inode);
866 }
867 EXPORT_SYMBOL_GPL(nfs_revalidate_inode);
868 
869 static int nfs_invalidate_mapping(struct inode *inode, struct address_space *mapping)
870 {
871 	struct nfs_inode *nfsi = NFS_I(inode);
872 
873 	if (mapping->nrpages != 0) {
874 		int ret = invalidate_inode_pages2(mapping);
875 		if (ret < 0)
876 			return ret;
877 	}
878 	spin_lock(&inode->i_lock);
879 	nfsi->cache_validity &= ~NFS_INO_INVALID_DATA;
880 	if (S_ISDIR(inode->i_mode))
881 		memset(nfsi->cookieverf, 0, sizeof(nfsi->cookieverf));
882 	spin_unlock(&inode->i_lock);
883 	nfs_inc_stats(inode, NFSIOS_DATAINVALIDATE);
884 	nfs_fscache_wait_on_invalidate(inode);
885 	dfprintk(PAGECACHE, "NFS: (%s/%Ld) data cache invalidated\n",
886 			inode->i_sb->s_id, (long long)NFS_FILEID(inode));
887 	return 0;
888 }
889 
890 static bool nfs_mapping_need_revalidate_inode(struct inode *inode)
891 {
892 	if (nfs_have_delegated_attributes(inode))
893 		return false;
894 	return (NFS_I(inode)->cache_validity & NFS_INO_REVAL_PAGECACHE)
895 		|| nfs_attribute_timeout(inode)
896 		|| NFS_STALE(inode);
897 }
898 
899 /**
900  * nfs_revalidate_mapping - Revalidate the pagecache
901  * @inode - pointer to host inode
902  * @mapping - pointer to mapping
903  */
904 int nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping)
905 {
906 	struct nfs_inode *nfsi = NFS_I(inode);
907 	int ret = 0;
908 
909 	/* swapfiles are not supposed to be shared. */
910 	if (IS_SWAPFILE(inode))
911 		goto out;
912 
913 	if (nfs_mapping_need_revalidate_inode(inode)) {
914 		ret = __nfs_revalidate_inode(NFS_SERVER(inode), inode);
915 		if (ret < 0)
916 			goto out;
917 	}
918 	if (nfsi->cache_validity & NFS_INO_INVALID_DATA)
919 		ret = nfs_invalidate_mapping(inode, mapping);
920 out:
921 	return ret;
922 }
923 
924 static unsigned long nfs_wcc_update_inode(struct inode *inode, struct nfs_fattr *fattr)
925 {
926 	struct nfs_inode *nfsi = NFS_I(inode);
927 	unsigned long ret = 0;
928 
929 	if ((fattr->valid & NFS_ATTR_FATTR_PRECHANGE)
930 			&& (fattr->valid & NFS_ATTR_FATTR_CHANGE)
931 			&& inode->i_version == fattr->pre_change_attr) {
932 		inode->i_version = fattr->change_attr;
933 		if (S_ISDIR(inode->i_mode))
934 			nfsi->cache_validity |= NFS_INO_INVALID_DATA;
935 		ret |= NFS_INO_INVALID_ATTR;
936 	}
937 	/* If we have atomic WCC data, we may update some attributes */
938 	if ((fattr->valid & NFS_ATTR_FATTR_PRECTIME)
939 			&& (fattr->valid & NFS_ATTR_FATTR_CTIME)
940 			&& timespec_equal(&inode->i_ctime, &fattr->pre_ctime)) {
941 		memcpy(&inode->i_ctime, &fattr->ctime, sizeof(inode->i_ctime));
942 		ret |= NFS_INO_INVALID_ATTR;
943 	}
944 
945 	if ((fattr->valid & NFS_ATTR_FATTR_PREMTIME)
946 			&& (fattr->valid & NFS_ATTR_FATTR_MTIME)
947 			&& timespec_equal(&inode->i_mtime, &fattr->pre_mtime)) {
948 		memcpy(&inode->i_mtime, &fattr->mtime, sizeof(inode->i_mtime));
949 		if (S_ISDIR(inode->i_mode))
950 			nfsi->cache_validity |= NFS_INO_INVALID_DATA;
951 		ret |= NFS_INO_INVALID_ATTR;
952 	}
953 	if ((fattr->valid & NFS_ATTR_FATTR_PRESIZE)
954 			&& (fattr->valid & NFS_ATTR_FATTR_SIZE)
955 			&& i_size_read(inode) == nfs_size_to_loff_t(fattr->pre_size)
956 			&& nfsi->npages == 0) {
957 		i_size_write(inode, nfs_size_to_loff_t(fattr->size));
958 		ret |= NFS_INO_INVALID_ATTR;
959 	}
960 
961 	if (nfsi->cache_validity & NFS_INO_INVALID_DATA)
962 		nfs_fscache_invalidate(inode);
963 
964 	return ret;
965 }
966 
967 /**
968  * nfs_check_inode_attributes - verify consistency of the inode attribute cache
969  * @inode - pointer to inode
970  * @fattr - updated attributes
971  *
972  * Verifies the attribute cache. If we have just changed the attributes,
973  * so that fattr carries weak cache consistency data, then it may
974  * also update the ctime/mtime/change_attribute.
975  */
976 static int nfs_check_inode_attributes(struct inode *inode, struct nfs_fattr *fattr)
977 {
978 	struct nfs_inode *nfsi = NFS_I(inode);
979 	loff_t cur_size, new_isize;
980 	unsigned long invalid = 0;
981 
982 
983 	if (nfs_have_delegated_attributes(inode))
984 		return 0;
985 	/* Has the inode gone and changed behind our back? */
986 	if ((fattr->valid & NFS_ATTR_FATTR_FILEID) && nfsi->fileid != fattr->fileid)
987 		return -EIO;
988 	if ((fattr->valid & NFS_ATTR_FATTR_TYPE) && (inode->i_mode & S_IFMT) != (fattr->mode & S_IFMT))
989 		return -EIO;
990 
991 	if ((fattr->valid & NFS_ATTR_FATTR_CHANGE) != 0 &&
992 			inode->i_version != fattr->change_attr)
993 		invalid |= NFS_INO_INVALID_ATTR|NFS_INO_REVAL_PAGECACHE;
994 
995 	/* Verify a few of the more important attributes */
996 	if ((fattr->valid & NFS_ATTR_FATTR_MTIME) && !timespec_equal(&inode->i_mtime, &fattr->mtime))
997 		invalid |= NFS_INO_INVALID_ATTR;
998 
999 	if (fattr->valid & NFS_ATTR_FATTR_SIZE) {
1000 		cur_size = i_size_read(inode);
1001 		new_isize = nfs_size_to_loff_t(fattr->size);
1002 		if (cur_size != new_isize && nfsi->npages == 0)
1003 			invalid |= NFS_INO_INVALID_ATTR|NFS_INO_REVAL_PAGECACHE;
1004 	}
1005 
1006 	/* Have any file permissions changed? */
1007 	if ((fattr->valid & NFS_ATTR_FATTR_MODE) && (inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO))
1008 		invalid |= NFS_INO_INVALID_ATTR | NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL;
1009 	if ((fattr->valid & NFS_ATTR_FATTR_OWNER) && !uid_eq(inode->i_uid, fattr->uid))
1010 		invalid |= NFS_INO_INVALID_ATTR | NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL;
1011 	if ((fattr->valid & NFS_ATTR_FATTR_GROUP) && !gid_eq(inode->i_gid, fattr->gid))
1012 		invalid |= NFS_INO_INVALID_ATTR | NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL;
1013 
1014 	/* Has the link count changed? */
1015 	if ((fattr->valid & NFS_ATTR_FATTR_NLINK) && inode->i_nlink != fattr->nlink)
1016 		invalid |= NFS_INO_INVALID_ATTR;
1017 
1018 	if ((fattr->valid & NFS_ATTR_FATTR_ATIME) && !timespec_equal(&inode->i_atime, &fattr->atime))
1019 		invalid |= NFS_INO_INVALID_ATIME;
1020 
1021 	if (invalid != 0)
1022 		nfsi->cache_validity |= invalid;
1023 
1024 	nfsi->read_cache_jiffies = fattr->time_start;
1025 	return 0;
1026 }
1027 
1028 static int nfs_ctime_need_update(const struct inode *inode, const struct nfs_fattr *fattr)
1029 {
1030 	if (!(fattr->valid & NFS_ATTR_FATTR_CTIME))
1031 		return 0;
1032 	return timespec_compare(&fattr->ctime, &inode->i_ctime) > 0;
1033 }
1034 
1035 static int nfs_size_need_update(const struct inode *inode, const struct nfs_fattr *fattr)
1036 {
1037 	if (!(fattr->valid & NFS_ATTR_FATTR_SIZE))
1038 		return 0;
1039 	return nfs_size_to_loff_t(fattr->size) > i_size_read(inode);
1040 }
1041 
1042 static atomic_long_t nfs_attr_generation_counter;
1043 
1044 static unsigned long nfs_read_attr_generation_counter(void)
1045 {
1046 	return atomic_long_read(&nfs_attr_generation_counter);
1047 }
1048 
1049 unsigned long nfs_inc_attr_generation_counter(void)
1050 {
1051 	return atomic_long_inc_return(&nfs_attr_generation_counter);
1052 }
1053 
1054 void nfs_fattr_init(struct nfs_fattr *fattr)
1055 {
1056 	fattr->valid = 0;
1057 	fattr->time_start = jiffies;
1058 	fattr->gencount = nfs_inc_attr_generation_counter();
1059 	fattr->owner_name = NULL;
1060 	fattr->group_name = NULL;
1061 }
1062 EXPORT_SYMBOL_GPL(nfs_fattr_init);
1063 
1064 struct nfs_fattr *nfs_alloc_fattr(void)
1065 {
1066 	struct nfs_fattr *fattr;
1067 
1068 	fattr = kmalloc(sizeof(*fattr), GFP_NOFS);
1069 	if (fattr != NULL)
1070 		nfs_fattr_init(fattr);
1071 	return fattr;
1072 }
1073 EXPORT_SYMBOL_GPL(nfs_alloc_fattr);
1074 
1075 struct nfs_fh *nfs_alloc_fhandle(void)
1076 {
1077 	struct nfs_fh *fh;
1078 
1079 	fh = kmalloc(sizeof(struct nfs_fh), GFP_NOFS);
1080 	if (fh != NULL)
1081 		fh->size = 0;
1082 	return fh;
1083 }
1084 EXPORT_SYMBOL_GPL(nfs_alloc_fhandle);
1085 
1086 #ifdef NFS_DEBUG
1087 /*
1088  * _nfs_display_fhandle_hash - calculate the crc32 hash for the filehandle
1089  *                             in the same way that wireshark does
1090  *
1091  * @fh: file handle
1092  *
1093  * For debugging only.
1094  */
1095 u32 _nfs_display_fhandle_hash(const struct nfs_fh *fh)
1096 {
1097 	/* wireshark uses 32-bit AUTODIN crc and does a bitwise
1098 	 * not on the result */
1099 	return ~crc32(0xFFFFFFFF, &fh->data[0], fh->size);
1100 }
1101 
1102 /*
1103  * _nfs_display_fhandle - display an NFS file handle on the console
1104  *
1105  * @fh: file handle to display
1106  * @caption: display caption
1107  *
1108  * For debugging only.
1109  */
1110 void _nfs_display_fhandle(const struct nfs_fh *fh, const char *caption)
1111 {
1112 	unsigned short i;
1113 
1114 	if (fh == NULL || fh->size == 0) {
1115 		printk(KERN_DEFAULT "%s at %p is empty\n", caption, fh);
1116 		return;
1117 	}
1118 
1119 	printk(KERN_DEFAULT "%s at %p is %u bytes, crc: 0x%08x:\n",
1120 	       caption, fh, fh->size, _nfs_display_fhandle_hash(fh));
1121 	for (i = 0; i < fh->size; i += 16) {
1122 		__be32 *pos = (__be32 *)&fh->data[i];
1123 
1124 		switch ((fh->size - i - 1) >> 2) {
1125 		case 0:
1126 			printk(KERN_DEFAULT " %08x\n",
1127 				be32_to_cpup(pos));
1128 			break;
1129 		case 1:
1130 			printk(KERN_DEFAULT " %08x %08x\n",
1131 				be32_to_cpup(pos), be32_to_cpup(pos + 1));
1132 			break;
1133 		case 2:
1134 			printk(KERN_DEFAULT " %08x %08x %08x\n",
1135 				be32_to_cpup(pos), be32_to_cpup(pos + 1),
1136 				be32_to_cpup(pos + 2));
1137 			break;
1138 		default:
1139 			printk(KERN_DEFAULT " %08x %08x %08x %08x\n",
1140 				be32_to_cpup(pos), be32_to_cpup(pos + 1),
1141 				be32_to_cpup(pos + 2), be32_to_cpup(pos + 3));
1142 		}
1143 	}
1144 }
1145 #endif
1146 
1147 /**
1148  * nfs_inode_attrs_need_update - check if the inode attributes need updating
1149  * @inode - pointer to inode
1150  * @fattr - attributes
1151  *
1152  * Attempt to divine whether or not an RPC call reply carrying stale
1153  * attributes got scheduled after another call carrying updated ones.
1154  *
1155  * To do so, the function first assumes that a more recent ctime means
1156  * that the attributes in fattr are newer, however it also attempt to
1157  * catch the case where ctime either didn't change, or went backwards
1158  * (if someone reset the clock on the server) by looking at whether
1159  * or not this RPC call was started after the inode was last updated.
1160  * Note also the check for wraparound of 'attr_gencount'
1161  *
1162  * The function returns 'true' if it thinks the attributes in 'fattr' are
1163  * more recent than the ones cached in the inode.
1164  *
1165  */
1166 static int nfs_inode_attrs_need_update(const struct inode *inode, const struct nfs_fattr *fattr)
1167 {
1168 	const struct nfs_inode *nfsi = NFS_I(inode);
1169 
1170 	return ((long)fattr->gencount - (long)nfsi->attr_gencount) > 0 ||
1171 		nfs_ctime_need_update(inode, fattr) ||
1172 		nfs_size_need_update(inode, fattr) ||
1173 		((long)nfsi->attr_gencount - (long)nfs_read_attr_generation_counter() > 0);
1174 }
1175 
1176 static int nfs_refresh_inode_locked(struct inode *inode, struct nfs_fattr *fattr)
1177 {
1178 	if (nfs_inode_attrs_need_update(inode, fattr))
1179 		return nfs_update_inode(inode, fattr);
1180 	return nfs_check_inode_attributes(inode, fattr);
1181 }
1182 
1183 /**
1184  * nfs_refresh_inode - try to update the inode attribute cache
1185  * @inode - pointer to inode
1186  * @fattr - updated attributes
1187  *
1188  * Check that an RPC call that returned attributes has not overlapped with
1189  * other recent updates of the inode metadata, then decide whether it is
1190  * safe to do a full update of the inode attributes, or whether just to
1191  * call nfs_check_inode_attributes.
1192  */
1193 int nfs_refresh_inode(struct inode *inode, struct nfs_fattr *fattr)
1194 {
1195 	int status;
1196 
1197 	if ((fattr->valid & NFS_ATTR_FATTR) == 0)
1198 		return 0;
1199 	spin_lock(&inode->i_lock);
1200 	status = nfs_refresh_inode_locked(inode, fattr);
1201 	spin_unlock(&inode->i_lock);
1202 
1203 	return status;
1204 }
1205 EXPORT_SYMBOL_GPL(nfs_refresh_inode);
1206 
1207 static int nfs_post_op_update_inode_locked(struct inode *inode, struct nfs_fattr *fattr)
1208 {
1209 	struct nfs_inode *nfsi = NFS_I(inode);
1210 
1211 	nfsi->cache_validity |= NFS_INO_INVALID_ATTR|NFS_INO_REVAL_PAGECACHE;
1212 	if (S_ISDIR(inode->i_mode)) {
1213 		nfsi->cache_validity |= NFS_INO_INVALID_DATA;
1214 		nfs_fscache_invalidate(inode);
1215 	}
1216 	if ((fattr->valid & NFS_ATTR_FATTR) == 0)
1217 		return 0;
1218 	return nfs_refresh_inode_locked(inode, fattr);
1219 }
1220 
1221 /**
1222  * nfs_post_op_update_inode - try to update the inode attribute cache
1223  * @inode - pointer to inode
1224  * @fattr - updated attributes
1225  *
1226  * After an operation that has changed the inode metadata, mark the
1227  * attribute cache as being invalid, then try to update it.
1228  *
1229  * NB: if the server didn't return any post op attributes, this
1230  * function will force the retrieval of attributes before the next
1231  * NFS request.  Thus it should be used only for operations that
1232  * are expected to change one or more attributes, to avoid
1233  * unnecessary NFS requests and trips through nfs_update_inode().
1234  */
1235 int nfs_post_op_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1236 {
1237 	int status;
1238 
1239 	spin_lock(&inode->i_lock);
1240 	status = nfs_post_op_update_inode_locked(inode, fattr);
1241 	spin_unlock(&inode->i_lock);
1242 	return status;
1243 }
1244 EXPORT_SYMBOL_GPL(nfs_post_op_update_inode);
1245 
1246 /**
1247  * nfs_post_op_update_inode_force_wcc - try to update the inode attribute cache
1248  * @inode - pointer to inode
1249  * @fattr - updated attributes
1250  *
1251  * After an operation that has changed the inode metadata, mark the
1252  * attribute cache as being invalid, then try to update it. Fake up
1253  * weak cache consistency data, if none exist.
1254  *
1255  * This function is mainly designed to be used by the ->write_done() functions.
1256  */
1257 int nfs_post_op_update_inode_force_wcc(struct inode *inode, struct nfs_fattr *fattr)
1258 {
1259 	int status;
1260 
1261 	spin_lock(&inode->i_lock);
1262 	/* Don't do a WCC update if these attributes are already stale */
1263 	if ((fattr->valid & NFS_ATTR_FATTR) == 0 ||
1264 			!nfs_inode_attrs_need_update(inode, fattr)) {
1265 		fattr->valid &= ~(NFS_ATTR_FATTR_PRECHANGE
1266 				| NFS_ATTR_FATTR_PRESIZE
1267 				| NFS_ATTR_FATTR_PREMTIME
1268 				| NFS_ATTR_FATTR_PRECTIME);
1269 		goto out_noforce;
1270 	}
1271 	if ((fattr->valid & NFS_ATTR_FATTR_CHANGE) != 0 &&
1272 			(fattr->valid & NFS_ATTR_FATTR_PRECHANGE) == 0) {
1273 		fattr->pre_change_attr = inode->i_version;
1274 		fattr->valid |= NFS_ATTR_FATTR_PRECHANGE;
1275 	}
1276 	if ((fattr->valid & NFS_ATTR_FATTR_CTIME) != 0 &&
1277 			(fattr->valid & NFS_ATTR_FATTR_PRECTIME) == 0) {
1278 		memcpy(&fattr->pre_ctime, &inode->i_ctime, sizeof(fattr->pre_ctime));
1279 		fattr->valid |= NFS_ATTR_FATTR_PRECTIME;
1280 	}
1281 	if ((fattr->valid & NFS_ATTR_FATTR_MTIME) != 0 &&
1282 			(fattr->valid & NFS_ATTR_FATTR_PREMTIME) == 0) {
1283 		memcpy(&fattr->pre_mtime, &inode->i_mtime, sizeof(fattr->pre_mtime));
1284 		fattr->valid |= NFS_ATTR_FATTR_PREMTIME;
1285 	}
1286 	if ((fattr->valid & NFS_ATTR_FATTR_SIZE) != 0 &&
1287 			(fattr->valid & NFS_ATTR_FATTR_PRESIZE) == 0) {
1288 		fattr->pre_size = i_size_read(inode);
1289 		fattr->valid |= NFS_ATTR_FATTR_PRESIZE;
1290 	}
1291 out_noforce:
1292 	status = nfs_post_op_update_inode_locked(inode, fattr);
1293 	spin_unlock(&inode->i_lock);
1294 	return status;
1295 }
1296 EXPORT_SYMBOL_GPL(nfs_post_op_update_inode_force_wcc);
1297 
1298 /*
1299  * Many nfs protocol calls return the new file attributes after
1300  * an operation.  Here we update the inode to reflect the state
1301  * of the server's inode.
1302  *
1303  * This is a bit tricky because we have to make sure all dirty pages
1304  * have been sent off to the server before calling invalidate_inode_pages.
1305  * To make sure no other process adds more write requests while we try
1306  * our best to flush them, we make them sleep during the attribute refresh.
1307  *
1308  * A very similar scenario holds for the dir cache.
1309  */
1310 static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1311 {
1312 	struct nfs_server *server;
1313 	struct nfs_inode *nfsi = NFS_I(inode);
1314 	loff_t cur_isize, new_isize;
1315 	unsigned long invalid = 0;
1316 	unsigned long now = jiffies;
1317 	unsigned long save_cache_validity;
1318 
1319 	dfprintk(VFS, "NFS: %s(%s/%ld fh_crc=0x%08x ct=%d info=0x%x)\n",
1320 			__func__, inode->i_sb->s_id, inode->i_ino,
1321 			nfs_display_fhandle_hash(NFS_FH(inode)),
1322 			atomic_read(&inode->i_count), fattr->valid);
1323 
1324 	if ((fattr->valid & NFS_ATTR_FATTR_FILEID) && nfsi->fileid != fattr->fileid) {
1325 		printk(KERN_ERR "NFS: server %s error: fileid changed\n"
1326 			"fsid %s: expected fileid 0x%Lx, got 0x%Lx\n",
1327 			NFS_SERVER(inode)->nfs_client->cl_hostname,
1328 			inode->i_sb->s_id, (long long)nfsi->fileid,
1329 			(long long)fattr->fileid);
1330 		goto out_err;
1331 	}
1332 
1333 	/*
1334 	 * Make sure the inode's type hasn't changed.
1335 	 */
1336 	if ((fattr->valid & NFS_ATTR_FATTR_TYPE) && (inode->i_mode & S_IFMT) != (fattr->mode & S_IFMT)) {
1337 		/*
1338 		* Big trouble! The inode has become a different object.
1339 		*/
1340 		printk(KERN_DEBUG "NFS: %s: inode %ld mode changed, %07o to %07o\n",
1341 				__func__, inode->i_ino, inode->i_mode, fattr->mode);
1342 		goto out_err;
1343 	}
1344 
1345 	server = NFS_SERVER(inode);
1346 	/* Update the fsid? */
1347 	if (S_ISDIR(inode->i_mode) && (fattr->valid & NFS_ATTR_FATTR_FSID) &&
1348 			!nfs_fsid_equal(&server->fsid, &fattr->fsid) &&
1349 			!IS_AUTOMOUNT(inode))
1350 		server->fsid = fattr->fsid;
1351 
1352 	/*
1353 	 * Update the read time so we don't revalidate too often.
1354 	 */
1355 	nfsi->read_cache_jiffies = fattr->time_start;
1356 
1357 	save_cache_validity = nfsi->cache_validity;
1358 	nfsi->cache_validity &= ~(NFS_INO_INVALID_ATTR
1359 			| NFS_INO_INVALID_ATIME
1360 			| NFS_INO_REVAL_FORCED
1361 			| NFS_INO_REVAL_PAGECACHE);
1362 
1363 	/* Do atomic weak cache consistency updates */
1364 	invalid |= nfs_wcc_update_inode(inode, fattr);
1365 
1366 	/* More cache consistency checks */
1367 	if (fattr->valid & NFS_ATTR_FATTR_CHANGE) {
1368 		if (inode->i_version != fattr->change_attr) {
1369 			dprintk("NFS: change_attr change on server for file %s/%ld\n",
1370 					inode->i_sb->s_id, inode->i_ino);
1371 			invalid |= NFS_INO_INVALID_ATTR
1372 				| NFS_INO_INVALID_DATA
1373 				| NFS_INO_INVALID_ACCESS
1374 				| NFS_INO_INVALID_ACL
1375 				| NFS_INO_REVAL_PAGECACHE;
1376 			if (S_ISDIR(inode->i_mode))
1377 				nfs_force_lookup_revalidate(inode);
1378 			inode->i_version = fattr->change_attr;
1379 		}
1380 	} else if (server->caps & NFS_CAP_CHANGE_ATTR)
1381 		invalid |= save_cache_validity;
1382 
1383 	if (fattr->valid & NFS_ATTR_FATTR_MTIME) {
1384 		memcpy(&inode->i_mtime, &fattr->mtime, sizeof(inode->i_mtime));
1385 	} else if (server->caps & NFS_CAP_MTIME)
1386 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1387 				| NFS_INO_REVAL_FORCED);
1388 
1389 	if (fattr->valid & NFS_ATTR_FATTR_CTIME) {
1390 		memcpy(&inode->i_ctime, &fattr->ctime, sizeof(inode->i_ctime));
1391 	} else if (server->caps & NFS_CAP_CTIME)
1392 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1393 				| NFS_INO_REVAL_FORCED);
1394 
1395 	/* Check if our cached file size is stale */
1396 	if (fattr->valid & NFS_ATTR_FATTR_SIZE) {
1397 		new_isize = nfs_size_to_loff_t(fattr->size);
1398 		cur_isize = i_size_read(inode);
1399 		if (new_isize != cur_isize) {
1400 			/* Do we perhaps have any outstanding writes, or has
1401 			 * the file grown beyond our last write? */
1402 			if ((nfsi->npages == 0 && !test_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags)) ||
1403 			     new_isize > cur_isize) {
1404 				i_size_write(inode, new_isize);
1405 				invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA;
1406 			}
1407 			dprintk("NFS: isize change on server for file %s/%ld "
1408 					"(%Ld to %Ld)\n",
1409 					inode->i_sb->s_id,
1410 					inode->i_ino,
1411 					(long long)cur_isize,
1412 					(long long)new_isize);
1413 		}
1414 	} else
1415 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1416 				| NFS_INO_REVAL_PAGECACHE
1417 				| NFS_INO_REVAL_FORCED);
1418 
1419 
1420 	if (fattr->valid & NFS_ATTR_FATTR_ATIME)
1421 		memcpy(&inode->i_atime, &fattr->atime, sizeof(inode->i_atime));
1422 	else if (server->caps & NFS_CAP_ATIME)
1423 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATIME
1424 				| NFS_INO_REVAL_FORCED);
1425 
1426 	if (fattr->valid & NFS_ATTR_FATTR_MODE) {
1427 		if ((inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO)) {
1428 			umode_t newmode = inode->i_mode & S_IFMT;
1429 			newmode |= fattr->mode & S_IALLUGO;
1430 			inode->i_mode = newmode;
1431 			invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1432 		}
1433 	} else if (server->caps & NFS_CAP_MODE)
1434 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1435 				| NFS_INO_INVALID_ACCESS
1436 				| NFS_INO_INVALID_ACL
1437 				| NFS_INO_REVAL_FORCED);
1438 
1439 	if (fattr->valid & NFS_ATTR_FATTR_OWNER) {
1440 		if (!uid_eq(inode->i_uid, fattr->uid)) {
1441 			invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1442 			inode->i_uid = fattr->uid;
1443 		}
1444 	} else if (server->caps & NFS_CAP_OWNER)
1445 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1446 				| NFS_INO_INVALID_ACCESS
1447 				| NFS_INO_INVALID_ACL
1448 				| NFS_INO_REVAL_FORCED);
1449 
1450 	if (fattr->valid & NFS_ATTR_FATTR_GROUP) {
1451 		if (!gid_eq(inode->i_gid, fattr->gid)) {
1452 			invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1453 			inode->i_gid = fattr->gid;
1454 		}
1455 	} else if (server->caps & NFS_CAP_OWNER_GROUP)
1456 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1457 				| NFS_INO_INVALID_ACCESS
1458 				| NFS_INO_INVALID_ACL
1459 				| NFS_INO_REVAL_FORCED);
1460 
1461 	if (fattr->valid & NFS_ATTR_FATTR_NLINK) {
1462 		if (inode->i_nlink != fattr->nlink) {
1463 			invalid |= NFS_INO_INVALID_ATTR;
1464 			if (S_ISDIR(inode->i_mode))
1465 				invalid |= NFS_INO_INVALID_DATA;
1466 			set_nlink(inode, fattr->nlink);
1467 		}
1468 	} else if (server->caps & NFS_CAP_NLINK)
1469 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1470 				| NFS_INO_REVAL_FORCED);
1471 
1472 	if (fattr->valid & NFS_ATTR_FATTR_SPACE_USED) {
1473 		/*
1474 		 * report the blocks in 512byte units
1475 		 */
1476 		inode->i_blocks = nfs_calc_block_size(fattr->du.nfs3.used);
1477  	}
1478 	if (fattr->valid & NFS_ATTR_FATTR_BLOCKS_USED)
1479 		inode->i_blocks = fattr->du.nfs2.blocks;
1480 
1481 	/* Update attrtimeo value if we're out of the unstable period */
1482 	if (invalid & NFS_INO_INVALID_ATTR) {
1483 		nfs_inc_stats(inode, NFSIOS_ATTRINVALIDATE);
1484 		nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
1485 		nfsi->attrtimeo_timestamp = now;
1486 		nfsi->attr_gencount = nfs_inc_attr_generation_counter();
1487 	} else {
1488 		if (!time_in_range_open(now, nfsi->attrtimeo_timestamp, nfsi->attrtimeo_timestamp + nfsi->attrtimeo)) {
1489 			if ((nfsi->attrtimeo <<= 1) > NFS_MAXATTRTIMEO(inode))
1490 				nfsi->attrtimeo = NFS_MAXATTRTIMEO(inode);
1491 			nfsi->attrtimeo_timestamp = now;
1492 		}
1493 	}
1494 	invalid &= ~NFS_INO_INVALID_ATTR;
1495 	/* Don't invalidate the data if we were to blame */
1496 	if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)
1497 				|| S_ISLNK(inode->i_mode)))
1498 		invalid &= ~NFS_INO_INVALID_DATA;
1499 	if (!NFS_PROTO(inode)->have_delegation(inode, FMODE_READ) ||
1500 			(save_cache_validity & NFS_INO_REVAL_FORCED))
1501 		nfsi->cache_validity |= invalid;
1502 
1503 	if (invalid & NFS_INO_INVALID_DATA)
1504 		nfs_fscache_invalidate(inode);
1505 
1506 	return 0;
1507  out_err:
1508 	/*
1509 	 * No need to worry about unhashing the dentry, as the
1510 	 * lookup validation will know that the inode is bad.
1511 	 * (But we fall through to invalidate the caches.)
1512 	 */
1513 	nfs_invalidate_inode(inode);
1514 	return -ESTALE;
1515 }
1516 
1517 struct inode *nfs_alloc_inode(struct super_block *sb)
1518 {
1519 	struct nfs_inode *nfsi;
1520 	nfsi = (struct nfs_inode *)kmem_cache_alloc(nfs_inode_cachep, GFP_KERNEL);
1521 	if (!nfsi)
1522 		return NULL;
1523 	nfsi->flags = 0UL;
1524 	nfsi->cache_validity = 0UL;
1525 #ifdef CONFIG_NFS_V3_ACL
1526 	nfsi->acl_access = ERR_PTR(-EAGAIN);
1527 	nfsi->acl_default = ERR_PTR(-EAGAIN);
1528 #endif
1529 #if IS_ENABLED(CONFIG_NFS_V4)
1530 	nfsi->nfs4_acl = NULL;
1531 #endif /* CONFIG_NFS_V4 */
1532 	return &nfsi->vfs_inode;
1533 }
1534 EXPORT_SYMBOL_GPL(nfs_alloc_inode);
1535 
1536 static void nfs_i_callback(struct rcu_head *head)
1537 {
1538 	struct inode *inode = container_of(head, struct inode, i_rcu);
1539 	kmem_cache_free(nfs_inode_cachep, NFS_I(inode));
1540 }
1541 
1542 void nfs_destroy_inode(struct inode *inode)
1543 {
1544 	call_rcu(&inode->i_rcu, nfs_i_callback);
1545 }
1546 EXPORT_SYMBOL_GPL(nfs_destroy_inode);
1547 
1548 static inline void nfs4_init_once(struct nfs_inode *nfsi)
1549 {
1550 #if IS_ENABLED(CONFIG_NFS_V4)
1551 	INIT_LIST_HEAD(&nfsi->open_states);
1552 	nfsi->delegation = NULL;
1553 	nfsi->delegation_state = 0;
1554 	init_rwsem(&nfsi->rwsem);
1555 	nfsi->layout = NULL;
1556 #endif
1557 }
1558 
1559 static void init_once(void *foo)
1560 {
1561 	struct nfs_inode *nfsi = (struct nfs_inode *) foo;
1562 
1563 	inode_init_once(&nfsi->vfs_inode);
1564 	INIT_LIST_HEAD(&nfsi->open_files);
1565 	INIT_LIST_HEAD(&nfsi->access_cache_entry_lru);
1566 	INIT_LIST_HEAD(&nfsi->access_cache_inode_lru);
1567 	INIT_LIST_HEAD(&nfsi->commit_info.list);
1568 	nfsi->npages = 0;
1569 	nfsi->commit_info.ncommit = 0;
1570 	atomic_set(&nfsi->commit_info.rpcs_out, 0);
1571 	atomic_set(&nfsi->silly_count, 1);
1572 	INIT_HLIST_HEAD(&nfsi->silly_list);
1573 	init_waitqueue_head(&nfsi->waitqueue);
1574 	nfs4_init_once(nfsi);
1575 }
1576 
1577 static int __init nfs_init_inodecache(void)
1578 {
1579 	nfs_inode_cachep = kmem_cache_create("nfs_inode_cache",
1580 					     sizeof(struct nfs_inode),
1581 					     0, (SLAB_RECLAIM_ACCOUNT|
1582 						SLAB_MEM_SPREAD),
1583 					     init_once);
1584 	if (nfs_inode_cachep == NULL)
1585 		return -ENOMEM;
1586 
1587 	return 0;
1588 }
1589 
1590 static void nfs_destroy_inodecache(void)
1591 {
1592 	/*
1593 	 * Make sure all delayed rcu free inodes are flushed before we
1594 	 * destroy cache.
1595 	 */
1596 	rcu_barrier();
1597 	kmem_cache_destroy(nfs_inode_cachep);
1598 }
1599 
1600 struct workqueue_struct *nfsiod_workqueue;
1601 EXPORT_SYMBOL_GPL(nfsiod_workqueue);
1602 
1603 /*
1604  * start up the nfsiod workqueue
1605  */
1606 static int nfsiod_start(void)
1607 {
1608 	struct workqueue_struct *wq;
1609 	dprintk("RPC:       creating workqueue nfsiod\n");
1610 	wq = alloc_workqueue("nfsiod", WQ_MEM_RECLAIM, 0);
1611 	if (wq == NULL)
1612 		return -ENOMEM;
1613 	nfsiod_workqueue = wq;
1614 	return 0;
1615 }
1616 
1617 /*
1618  * Destroy the nfsiod workqueue
1619  */
1620 static void nfsiod_stop(void)
1621 {
1622 	struct workqueue_struct *wq;
1623 
1624 	wq = nfsiod_workqueue;
1625 	if (wq == NULL)
1626 		return;
1627 	nfsiod_workqueue = NULL;
1628 	destroy_workqueue(wq);
1629 }
1630 
1631 int nfs_net_id;
1632 EXPORT_SYMBOL_GPL(nfs_net_id);
1633 
1634 static int nfs_net_init(struct net *net)
1635 {
1636 	nfs_clients_init(net);
1637 	return nfs_dns_resolver_cache_init(net);
1638 }
1639 
1640 static void nfs_net_exit(struct net *net)
1641 {
1642 	nfs_dns_resolver_cache_destroy(net);
1643 	nfs_cleanup_cb_ident_idr(net);
1644 }
1645 
1646 static struct pernet_operations nfs_net_ops = {
1647 	.init = nfs_net_init,
1648 	.exit = nfs_net_exit,
1649 	.id   = &nfs_net_id,
1650 	.size = sizeof(struct nfs_net),
1651 };
1652 
1653 /*
1654  * Initialize NFS
1655  */
1656 static int __init init_nfs_fs(void)
1657 {
1658 	int err;
1659 
1660 	err = nfs_dns_resolver_init();
1661 	if (err < 0)
1662 		goto out10;;
1663 
1664 	err = register_pernet_subsys(&nfs_net_ops);
1665 	if (err < 0)
1666 		goto out9;
1667 
1668 	err = nfs_fscache_register();
1669 	if (err < 0)
1670 		goto out8;
1671 
1672 	err = nfsiod_start();
1673 	if (err)
1674 		goto out7;
1675 
1676 	err = nfs_fs_proc_init();
1677 	if (err)
1678 		goto out6;
1679 
1680 	err = nfs_init_nfspagecache();
1681 	if (err)
1682 		goto out5;
1683 
1684 	err = nfs_init_inodecache();
1685 	if (err)
1686 		goto out4;
1687 
1688 	err = nfs_init_readpagecache();
1689 	if (err)
1690 		goto out3;
1691 
1692 	err = nfs_init_writepagecache();
1693 	if (err)
1694 		goto out2;
1695 
1696 	err = nfs_init_directcache();
1697 	if (err)
1698 		goto out1;
1699 
1700 #ifdef CONFIG_PROC_FS
1701 	rpc_proc_register(&init_net, &nfs_rpcstat);
1702 #endif
1703 	if ((err = register_nfs_fs()) != 0)
1704 		goto out0;
1705 
1706 	return 0;
1707 out0:
1708 #ifdef CONFIG_PROC_FS
1709 	rpc_proc_unregister(&init_net, "nfs");
1710 #endif
1711 	nfs_destroy_directcache();
1712 out1:
1713 	nfs_destroy_writepagecache();
1714 out2:
1715 	nfs_destroy_readpagecache();
1716 out3:
1717 	nfs_destroy_inodecache();
1718 out4:
1719 	nfs_destroy_nfspagecache();
1720 out5:
1721 	nfs_fs_proc_exit();
1722 out6:
1723 	nfsiod_stop();
1724 out7:
1725 	nfs_fscache_unregister();
1726 out8:
1727 	unregister_pernet_subsys(&nfs_net_ops);
1728 out9:
1729 	nfs_dns_resolver_destroy();
1730 out10:
1731 	return err;
1732 }
1733 
1734 static void __exit exit_nfs_fs(void)
1735 {
1736 	nfs_destroy_directcache();
1737 	nfs_destroy_writepagecache();
1738 	nfs_destroy_readpagecache();
1739 	nfs_destroy_inodecache();
1740 	nfs_destroy_nfspagecache();
1741 	nfs_fscache_unregister();
1742 	unregister_pernet_subsys(&nfs_net_ops);
1743 	nfs_dns_resolver_destroy();
1744 #ifdef CONFIG_PROC_FS
1745 	rpc_proc_unregister(&init_net, "nfs");
1746 #endif
1747 	unregister_nfs_fs();
1748 	nfs_fs_proc_exit();
1749 	nfsiod_stop();
1750 }
1751 
1752 /* Not quite true; I just maintain it */
1753 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
1754 MODULE_LICENSE("GPL");
1755 module_param(enable_ino64, bool, 0644);
1756 
1757 module_init(init_nfs_fs)
1758 module_exit(exit_nfs_fs)
1759