xref: /linux/fs/nfs/inode.c (revision d0b73b488c55df905ea8faaad079f8535629ed26)
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 = -2;
336 		inode->i_gid = -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 	if (is_sync)
698 		nfs_sb_deactive(sb);
699 	else
700 		nfs_sb_deactive_async(sb);
701 	kfree(ctx->mdsthreshold);
702 	kfree(ctx);
703 }
704 
705 void put_nfs_open_context(struct nfs_open_context *ctx)
706 {
707 	__put_nfs_open_context(ctx, 0);
708 }
709 EXPORT_SYMBOL_GPL(put_nfs_open_context);
710 
711 /*
712  * Ensure that mmap has a recent RPC credential for use when writing out
713  * shared pages
714  */
715 void nfs_file_set_open_context(struct file *filp, struct nfs_open_context *ctx)
716 {
717 	struct inode *inode = filp->f_path.dentry->d_inode;
718 	struct nfs_inode *nfsi = NFS_I(inode);
719 
720 	filp->private_data = get_nfs_open_context(ctx);
721 	spin_lock(&inode->i_lock);
722 	list_add(&ctx->list, &nfsi->open_files);
723 	spin_unlock(&inode->i_lock);
724 }
725 EXPORT_SYMBOL_GPL(nfs_file_set_open_context);
726 
727 /*
728  * Given an inode, search for an open context with the desired characteristics
729  */
730 struct nfs_open_context *nfs_find_open_context(struct inode *inode, struct rpc_cred *cred, fmode_t mode)
731 {
732 	struct nfs_inode *nfsi = NFS_I(inode);
733 	struct nfs_open_context *pos, *ctx = NULL;
734 
735 	spin_lock(&inode->i_lock);
736 	list_for_each_entry(pos, &nfsi->open_files, list) {
737 		if (cred != NULL && pos->cred != cred)
738 			continue;
739 		if ((pos->mode & (FMODE_READ|FMODE_WRITE)) != mode)
740 			continue;
741 		ctx = get_nfs_open_context(pos);
742 		break;
743 	}
744 	spin_unlock(&inode->i_lock);
745 	return ctx;
746 }
747 
748 static void nfs_file_clear_open_context(struct file *filp)
749 {
750 	struct inode *inode = filp->f_path.dentry->d_inode;
751 	struct nfs_open_context *ctx = nfs_file_open_context(filp);
752 
753 	if (ctx) {
754 		filp->private_data = NULL;
755 		spin_lock(&inode->i_lock);
756 		list_move_tail(&ctx->list, &NFS_I(inode)->open_files);
757 		spin_unlock(&inode->i_lock);
758 		__put_nfs_open_context(ctx, filp->f_flags & O_DIRECT ? 0 : 1);
759 	}
760 }
761 
762 /*
763  * These allocate and release file read/write context information.
764  */
765 int nfs_open(struct inode *inode, struct file *filp)
766 {
767 	struct nfs_open_context *ctx;
768 
769 	ctx = alloc_nfs_open_context(filp->f_path.dentry, filp->f_mode);
770 	if (IS_ERR(ctx))
771 		return PTR_ERR(ctx);
772 	nfs_file_set_open_context(filp, ctx);
773 	put_nfs_open_context(ctx);
774 	nfs_fscache_set_inode_cookie(inode, filp);
775 	return 0;
776 }
777 
778 int nfs_release(struct inode *inode, struct file *filp)
779 {
780 	nfs_file_clear_open_context(filp);
781 	return 0;
782 }
783 
784 /*
785  * This function is called whenever some part of NFS notices that
786  * the cached attributes have to be refreshed.
787  */
788 int
789 __nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
790 {
791 	int		 status = -ESTALE;
792 	struct nfs_fattr *fattr = NULL;
793 	struct nfs_inode *nfsi = NFS_I(inode);
794 
795 	dfprintk(PAGECACHE, "NFS: revalidating (%s/%Ld)\n",
796 		inode->i_sb->s_id, (long long)NFS_FILEID(inode));
797 
798 	if (is_bad_inode(inode))
799 		goto out;
800 	if (NFS_STALE(inode))
801 		goto out;
802 
803 	status = -ENOMEM;
804 	fattr = nfs_alloc_fattr();
805 	if (fattr == NULL)
806 		goto out;
807 
808 	nfs_inc_stats(inode, NFSIOS_INODEREVALIDATE);
809 	status = NFS_PROTO(inode)->getattr(server, NFS_FH(inode), fattr);
810 	if (status != 0) {
811 		dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Ld) getattr failed, error=%d\n",
812 			 inode->i_sb->s_id,
813 			 (long long)NFS_FILEID(inode), status);
814 		if (status == -ESTALE) {
815 			nfs_zap_caches(inode);
816 			if (!S_ISDIR(inode->i_mode))
817 				set_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
818 		}
819 		goto out;
820 	}
821 
822 	status = nfs_refresh_inode(inode, fattr);
823 	if (status) {
824 		dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Ld) refresh failed, error=%d\n",
825 			 inode->i_sb->s_id,
826 			 (long long)NFS_FILEID(inode), status);
827 		goto out;
828 	}
829 
830 	if (nfsi->cache_validity & NFS_INO_INVALID_ACL)
831 		nfs_zap_acl_cache(inode);
832 
833 	dfprintk(PAGECACHE, "NFS: (%s/%Ld) revalidation complete\n",
834 		inode->i_sb->s_id,
835 		(long long)NFS_FILEID(inode));
836 
837  out:
838 	nfs_free_fattr(fattr);
839 	return status;
840 }
841 
842 int nfs_attribute_timeout(struct inode *inode)
843 {
844 	struct nfs_inode *nfsi = NFS_I(inode);
845 
846 	return !time_in_range_open(jiffies, nfsi->read_cache_jiffies, nfsi->read_cache_jiffies + nfsi->attrtimeo);
847 }
848 
849 static int nfs_attribute_cache_expired(struct inode *inode)
850 {
851 	if (nfs_have_delegated_attributes(inode))
852 		return 0;
853 	return nfs_attribute_timeout(inode);
854 }
855 
856 /**
857  * nfs_revalidate_inode - Revalidate the inode attributes
858  * @server - pointer to nfs_server struct
859  * @inode - pointer to inode struct
860  *
861  * Updates inode attribute information by retrieving the data from the server.
862  */
863 int nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
864 {
865 	if (!(NFS_I(inode)->cache_validity & NFS_INO_INVALID_ATTR)
866 			&& !nfs_attribute_cache_expired(inode))
867 		return NFS_STALE(inode) ? -ESTALE : 0;
868 	return __nfs_revalidate_inode(server, inode);
869 }
870 EXPORT_SYMBOL_GPL(nfs_revalidate_inode);
871 
872 static int nfs_invalidate_mapping(struct inode *inode, struct address_space *mapping)
873 {
874 	struct nfs_inode *nfsi = NFS_I(inode);
875 
876 	if (mapping->nrpages != 0) {
877 		int ret = invalidate_inode_pages2(mapping);
878 		if (ret < 0)
879 			return ret;
880 	}
881 	spin_lock(&inode->i_lock);
882 	nfsi->cache_validity &= ~NFS_INO_INVALID_DATA;
883 	if (S_ISDIR(inode->i_mode))
884 		memset(nfsi->cookieverf, 0, sizeof(nfsi->cookieverf));
885 	spin_unlock(&inode->i_lock);
886 	nfs_inc_stats(inode, NFSIOS_DATAINVALIDATE);
887 	nfs_fscache_wait_on_invalidate(inode);
888 	dfprintk(PAGECACHE, "NFS: (%s/%Ld) data cache invalidated\n",
889 			inode->i_sb->s_id, (long long)NFS_FILEID(inode));
890 	return 0;
891 }
892 
893 static bool nfs_mapping_need_revalidate_inode(struct inode *inode)
894 {
895 	if (nfs_have_delegated_attributes(inode))
896 		return false;
897 	return (NFS_I(inode)->cache_validity & NFS_INO_REVAL_PAGECACHE)
898 		|| nfs_attribute_timeout(inode)
899 		|| NFS_STALE(inode);
900 }
901 
902 /**
903  * nfs_revalidate_mapping - Revalidate the pagecache
904  * @inode - pointer to host inode
905  * @mapping - pointer to mapping
906  */
907 int nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping)
908 {
909 	struct nfs_inode *nfsi = NFS_I(inode);
910 	int ret = 0;
911 
912 	/* swapfiles are not supposed to be shared. */
913 	if (IS_SWAPFILE(inode))
914 		goto out;
915 
916 	if (nfs_mapping_need_revalidate_inode(inode)) {
917 		ret = __nfs_revalidate_inode(NFS_SERVER(inode), inode);
918 		if (ret < 0)
919 			goto out;
920 	}
921 	if (nfsi->cache_validity & NFS_INO_INVALID_DATA)
922 		ret = nfs_invalidate_mapping(inode, mapping);
923 out:
924 	return ret;
925 }
926 
927 static unsigned long nfs_wcc_update_inode(struct inode *inode, struct nfs_fattr *fattr)
928 {
929 	struct nfs_inode *nfsi = NFS_I(inode);
930 	unsigned long ret = 0;
931 
932 	if ((fattr->valid & NFS_ATTR_FATTR_PRECHANGE)
933 			&& (fattr->valid & NFS_ATTR_FATTR_CHANGE)
934 			&& inode->i_version == fattr->pre_change_attr) {
935 		inode->i_version = fattr->change_attr;
936 		if (S_ISDIR(inode->i_mode))
937 			nfsi->cache_validity |= NFS_INO_INVALID_DATA;
938 		ret |= NFS_INO_INVALID_ATTR;
939 	}
940 	/* If we have atomic WCC data, we may update some attributes */
941 	if ((fattr->valid & NFS_ATTR_FATTR_PRECTIME)
942 			&& (fattr->valid & NFS_ATTR_FATTR_CTIME)
943 			&& timespec_equal(&inode->i_ctime, &fattr->pre_ctime)) {
944 		memcpy(&inode->i_ctime, &fattr->ctime, sizeof(inode->i_ctime));
945 		ret |= NFS_INO_INVALID_ATTR;
946 	}
947 
948 	if ((fattr->valid & NFS_ATTR_FATTR_PREMTIME)
949 			&& (fattr->valid & NFS_ATTR_FATTR_MTIME)
950 			&& timespec_equal(&inode->i_mtime, &fattr->pre_mtime)) {
951 		memcpy(&inode->i_mtime, &fattr->mtime, sizeof(inode->i_mtime));
952 		if (S_ISDIR(inode->i_mode))
953 			nfsi->cache_validity |= NFS_INO_INVALID_DATA;
954 		ret |= NFS_INO_INVALID_ATTR;
955 	}
956 	if ((fattr->valid & NFS_ATTR_FATTR_PRESIZE)
957 			&& (fattr->valid & NFS_ATTR_FATTR_SIZE)
958 			&& i_size_read(inode) == nfs_size_to_loff_t(fattr->pre_size)
959 			&& nfsi->npages == 0) {
960 		i_size_write(inode, nfs_size_to_loff_t(fattr->size));
961 		ret |= NFS_INO_INVALID_ATTR;
962 	}
963 
964 	if (nfsi->cache_validity & NFS_INO_INVALID_DATA)
965 		nfs_fscache_invalidate(inode);
966 
967 	return ret;
968 }
969 
970 /**
971  * nfs_check_inode_attributes - verify consistency of the inode attribute cache
972  * @inode - pointer to inode
973  * @fattr - updated attributes
974  *
975  * Verifies the attribute cache. If we have just changed the attributes,
976  * so that fattr carries weak cache consistency data, then it may
977  * also update the ctime/mtime/change_attribute.
978  */
979 static int nfs_check_inode_attributes(struct inode *inode, struct nfs_fattr *fattr)
980 {
981 	struct nfs_inode *nfsi = NFS_I(inode);
982 	loff_t cur_size, new_isize;
983 	unsigned long invalid = 0;
984 
985 
986 	if (nfs_have_delegated_attributes(inode))
987 		return 0;
988 	/* Has the inode gone and changed behind our back? */
989 	if ((fattr->valid & NFS_ATTR_FATTR_FILEID) && nfsi->fileid != fattr->fileid)
990 		return -EIO;
991 	if ((fattr->valid & NFS_ATTR_FATTR_TYPE) && (inode->i_mode & S_IFMT) != (fattr->mode & S_IFMT))
992 		return -EIO;
993 
994 	if ((fattr->valid & NFS_ATTR_FATTR_CHANGE) != 0 &&
995 			inode->i_version != fattr->change_attr)
996 		invalid |= NFS_INO_INVALID_ATTR|NFS_INO_REVAL_PAGECACHE;
997 
998 	/* Verify a few of the more important attributes */
999 	if ((fattr->valid & NFS_ATTR_FATTR_MTIME) && !timespec_equal(&inode->i_mtime, &fattr->mtime))
1000 		invalid |= NFS_INO_INVALID_ATTR;
1001 
1002 	if (fattr->valid & NFS_ATTR_FATTR_SIZE) {
1003 		cur_size = i_size_read(inode);
1004 		new_isize = nfs_size_to_loff_t(fattr->size);
1005 		if (cur_size != new_isize && nfsi->npages == 0)
1006 			invalid |= NFS_INO_INVALID_ATTR|NFS_INO_REVAL_PAGECACHE;
1007 	}
1008 
1009 	/* Have any file permissions changed? */
1010 	if ((fattr->valid & NFS_ATTR_FATTR_MODE) && (inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO))
1011 		invalid |= NFS_INO_INVALID_ATTR | NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL;
1012 	if ((fattr->valid & NFS_ATTR_FATTR_OWNER) && inode->i_uid != fattr->uid)
1013 		invalid |= NFS_INO_INVALID_ATTR | NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL;
1014 	if ((fattr->valid & NFS_ATTR_FATTR_GROUP) && inode->i_gid != fattr->gid)
1015 		invalid |= NFS_INO_INVALID_ATTR | NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL;
1016 
1017 	/* Has the link count changed? */
1018 	if ((fattr->valid & NFS_ATTR_FATTR_NLINK) && inode->i_nlink != fattr->nlink)
1019 		invalid |= NFS_INO_INVALID_ATTR;
1020 
1021 	if ((fattr->valid & NFS_ATTR_FATTR_ATIME) && !timespec_equal(&inode->i_atime, &fattr->atime))
1022 		invalid |= NFS_INO_INVALID_ATIME;
1023 
1024 	if (invalid != 0)
1025 		nfsi->cache_validity |= invalid;
1026 
1027 	nfsi->read_cache_jiffies = fattr->time_start;
1028 	return 0;
1029 }
1030 
1031 static int nfs_ctime_need_update(const struct inode *inode, const struct nfs_fattr *fattr)
1032 {
1033 	if (!(fattr->valid & NFS_ATTR_FATTR_CTIME))
1034 		return 0;
1035 	return timespec_compare(&fattr->ctime, &inode->i_ctime) > 0;
1036 }
1037 
1038 static int nfs_size_need_update(const struct inode *inode, const struct nfs_fattr *fattr)
1039 {
1040 	if (!(fattr->valid & NFS_ATTR_FATTR_SIZE))
1041 		return 0;
1042 	return nfs_size_to_loff_t(fattr->size) > i_size_read(inode);
1043 }
1044 
1045 static atomic_long_t nfs_attr_generation_counter;
1046 
1047 static unsigned long nfs_read_attr_generation_counter(void)
1048 {
1049 	return atomic_long_read(&nfs_attr_generation_counter);
1050 }
1051 
1052 unsigned long nfs_inc_attr_generation_counter(void)
1053 {
1054 	return atomic_long_inc_return(&nfs_attr_generation_counter);
1055 }
1056 
1057 void nfs_fattr_init(struct nfs_fattr *fattr)
1058 {
1059 	fattr->valid = 0;
1060 	fattr->time_start = jiffies;
1061 	fattr->gencount = nfs_inc_attr_generation_counter();
1062 	fattr->owner_name = NULL;
1063 	fattr->group_name = NULL;
1064 }
1065 EXPORT_SYMBOL_GPL(nfs_fattr_init);
1066 
1067 struct nfs_fattr *nfs_alloc_fattr(void)
1068 {
1069 	struct nfs_fattr *fattr;
1070 
1071 	fattr = kmalloc(sizeof(*fattr), GFP_NOFS);
1072 	if (fattr != NULL)
1073 		nfs_fattr_init(fattr);
1074 	return fattr;
1075 }
1076 EXPORT_SYMBOL_GPL(nfs_alloc_fattr);
1077 
1078 struct nfs_fh *nfs_alloc_fhandle(void)
1079 {
1080 	struct nfs_fh *fh;
1081 
1082 	fh = kmalloc(sizeof(struct nfs_fh), GFP_NOFS);
1083 	if (fh != NULL)
1084 		fh->size = 0;
1085 	return fh;
1086 }
1087 EXPORT_SYMBOL_GPL(nfs_alloc_fhandle);
1088 
1089 #ifdef NFS_DEBUG
1090 /*
1091  * _nfs_display_fhandle_hash - calculate the crc32 hash for the filehandle
1092  *                             in the same way that wireshark does
1093  *
1094  * @fh: file handle
1095  *
1096  * For debugging only.
1097  */
1098 u32 _nfs_display_fhandle_hash(const struct nfs_fh *fh)
1099 {
1100 	/* wireshark uses 32-bit AUTODIN crc and does a bitwise
1101 	 * not on the result */
1102 	return ~crc32(0xFFFFFFFF, &fh->data[0], fh->size);
1103 }
1104 
1105 /*
1106  * _nfs_display_fhandle - display an NFS file handle on the console
1107  *
1108  * @fh: file handle to display
1109  * @caption: display caption
1110  *
1111  * For debugging only.
1112  */
1113 void _nfs_display_fhandle(const struct nfs_fh *fh, const char *caption)
1114 {
1115 	unsigned short i;
1116 
1117 	if (fh == NULL || fh->size == 0) {
1118 		printk(KERN_DEFAULT "%s at %p is empty\n", caption, fh);
1119 		return;
1120 	}
1121 
1122 	printk(KERN_DEFAULT "%s at %p is %u bytes, crc: 0x%08x:\n",
1123 	       caption, fh, fh->size, _nfs_display_fhandle_hash(fh));
1124 	for (i = 0; i < fh->size; i += 16) {
1125 		__be32 *pos = (__be32 *)&fh->data[i];
1126 
1127 		switch ((fh->size - i - 1) >> 2) {
1128 		case 0:
1129 			printk(KERN_DEFAULT " %08x\n",
1130 				be32_to_cpup(pos));
1131 			break;
1132 		case 1:
1133 			printk(KERN_DEFAULT " %08x %08x\n",
1134 				be32_to_cpup(pos), be32_to_cpup(pos + 1));
1135 			break;
1136 		case 2:
1137 			printk(KERN_DEFAULT " %08x %08x %08x\n",
1138 				be32_to_cpup(pos), be32_to_cpup(pos + 1),
1139 				be32_to_cpup(pos + 2));
1140 			break;
1141 		default:
1142 			printk(KERN_DEFAULT " %08x %08x %08x %08x\n",
1143 				be32_to_cpup(pos), be32_to_cpup(pos + 1),
1144 				be32_to_cpup(pos + 2), be32_to_cpup(pos + 3));
1145 		}
1146 	}
1147 }
1148 #endif
1149 
1150 /**
1151  * nfs_inode_attrs_need_update - check if the inode attributes need updating
1152  * @inode - pointer to inode
1153  * @fattr - attributes
1154  *
1155  * Attempt to divine whether or not an RPC call reply carrying stale
1156  * attributes got scheduled after another call carrying updated ones.
1157  *
1158  * To do so, the function first assumes that a more recent ctime means
1159  * that the attributes in fattr are newer, however it also attempt to
1160  * catch the case where ctime either didn't change, or went backwards
1161  * (if someone reset the clock on the server) by looking at whether
1162  * or not this RPC call was started after the inode was last updated.
1163  * Note also the check for wraparound of 'attr_gencount'
1164  *
1165  * The function returns 'true' if it thinks the attributes in 'fattr' are
1166  * more recent than the ones cached in the inode.
1167  *
1168  */
1169 static int nfs_inode_attrs_need_update(const struct inode *inode, const struct nfs_fattr *fattr)
1170 {
1171 	const struct nfs_inode *nfsi = NFS_I(inode);
1172 
1173 	return ((long)fattr->gencount - (long)nfsi->attr_gencount) > 0 ||
1174 		nfs_ctime_need_update(inode, fattr) ||
1175 		nfs_size_need_update(inode, fattr) ||
1176 		((long)nfsi->attr_gencount - (long)nfs_read_attr_generation_counter() > 0);
1177 }
1178 
1179 static int nfs_refresh_inode_locked(struct inode *inode, struct nfs_fattr *fattr)
1180 {
1181 	if (nfs_inode_attrs_need_update(inode, fattr))
1182 		return nfs_update_inode(inode, fattr);
1183 	return nfs_check_inode_attributes(inode, fattr);
1184 }
1185 
1186 /**
1187  * nfs_refresh_inode - try to update the inode attribute cache
1188  * @inode - pointer to inode
1189  * @fattr - updated attributes
1190  *
1191  * Check that an RPC call that returned attributes has not overlapped with
1192  * other recent updates of the inode metadata, then decide whether it is
1193  * safe to do a full update of the inode attributes, or whether just to
1194  * call nfs_check_inode_attributes.
1195  */
1196 int nfs_refresh_inode(struct inode *inode, struct nfs_fattr *fattr)
1197 {
1198 	int status;
1199 
1200 	if ((fattr->valid & NFS_ATTR_FATTR) == 0)
1201 		return 0;
1202 	spin_lock(&inode->i_lock);
1203 	status = nfs_refresh_inode_locked(inode, fattr);
1204 	spin_unlock(&inode->i_lock);
1205 
1206 	return status;
1207 }
1208 EXPORT_SYMBOL_GPL(nfs_refresh_inode);
1209 
1210 static int nfs_post_op_update_inode_locked(struct inode *inode, struct nfs_fattr *fattr)
1211 {
1212 	struct nfs_inode *nfsi = NFS_I(inode);
1213 
1214 	nfsi->cache_validity |= NFS_INO_INVALID_ATTR|NFS_INO_REVAL_PAGECACHE;
1215 	if (S_ISDIR(inode->i_mode)) {
1216 		nfsi->cache_validity |= NFS_INO_INVALID_DATA;
1217 		nfs_fscache_invalidate(inode);
1218 	}
1219 	if ((fattr->valid & NFS_ATTR_FATTR) == 0)
1220 		return 0;
1221 	return nfs_refresh_inode_locked(inode, fattr);
1222 }
1223 
1224 /**
1225  * nfs_post_op_update_inode - try to update the inode attribute cache
1226  * @inode - pointer to inode
1227  * @fattr - updated attributes
1228  *
1229  * After an operation that has changed the inode metadata, mark the
1230  * attribute cache as being invalid, then try to update it.
1231  *
1232  * NB: if the server didn't return any post op attributes, this
1233  * function will force the retrieval of attributes before the next
1234  * NFS request.  Thus it should be used only for operations that
1235  * are expected to change one or more attributes, to avoid
1236  * unnecessary NFS requests and trips through nfs_update_inode().
1237  */
1238 int nfs_post_op_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1239 {
1240 	int status;
1241 
1242 	spin_lock(&inode->i_lock);
1243 	status = nfs_post_op_update_inode_locked(inode, fattr);
1244 	spin_unlock(&inode->i_lock);
1245 	return status;
1246 }
1247 EXPORT_SYMBOL_GPL(nfs_post_op_update_inode);
1248 
1249 /**
1250  * nfs_post_op_update_inode_force_wcc - try to update the inode attribute cache
1251  * @inode - pointer to inode
1252  * @fattr - updated attributes
1253  *
1254  * After an operation that has changed the inode metadata, mark the
1255  * attribute cache as being invalid, then try to update it. Fake up
1256  * weak cache consistency data, if none exist.
1257  *
1258  * This function is mainly designed to be used by the ->write_done() functions.
1259  */
1260 int nfs_post_op_update_inode_force_wcc(struct inode *inode, struct nfs_fattr *fattr)
1261 {
1262 	int status;
1263 
1264 	spin_lock(&inode->i_lock);
1265 	/* Don't do a WCC update if these attributes are already stale */
1266 	if ((fattr->valid & NFS_ATTR_FATTR) == 0 ||
1267 			!nfs_inode_attrs_need_update(inode, fattr)) {
1268 		fattr->valid &= ~(NFS_ATTR_FATTR_PRECHANGE
1269 				| NFS_ATTR_FATTR_PRESIZE
1270 				| NFS_ATTR_FATTR_PREMTIME
1271 				| NFS_ATTR_FATTR_PRECTIME);
1272 		goto out_noforce;
1273 	}
1274 	if ((fattr->valid & NFS_ATTR_FATTR_CHANGE) != 0 &&
1275 			(fattr->valid & NFS_ATTR_FATTR_PRECHANGE) == 0) {
1276 		fattr->pre_change_attr = inode->i_version;
1277 		fattr->valid |= NFS_ATTR_FATTR_PRECHANGE;
1278 	}
1279 	if ((fattr->valid & NFS_ATTR_FATTR_CTIME) != 0 &&
1280 			(fattr->valid & NFS_ATTR_FATTR_PRECTIME) == 0) {
1281 		memcpy(&fattr->pre_ctime, &inode->i_ctime, sizeof(fattr->pre_ctime));
1282 		fattr->valid |= NFS_ATTR_FATTR_PRECTIME;
1283 	}
1284 	if ((fattr->valid & NFS_ATTR_FATTR_MTIME) != 0 &&
1285 			(fattr->valid & NFS_ATTR_FATTR_PREMTIME) == 0) {
1286 		memcpy(&fattr->pre_mtime, &inode->i_mtime, sizeof(fattr->pre_mtime));
1287 		fattr->valid |= NFS_ATTR_FATTR_PREMTIME;
1288 	}
1289 	if ((fattr->valid & NFS_ATTR_FATTR_SIZE) != 0 &&
1290 			(fattr->valid & NFS_ATTR_FATTR_PRESIZE) == 0) {
1291 		fattr->pre_size = i_size_read(inode);
1292 		fattr->valid |= NFS_ATTR_FATTR_PRESIZE;
1293 	}
1294 out_noforce:
1295 	status = nfs_post_op_update_inode_locked(inode, fattr);
1296 	spin_unlock(&inode->i_lock);
1297 	return status;
1298 }
1299 EXPORT_SYMBOL_GPL(nfs_post_op_update_inode_force_wcc);
1300 
1301 /*
1302  * Many nfs protocol calls return the new file attributes after
1303  * an operation.  Here we update the inode to reflect the state
1304  * of the server's inode.
1305  *
1306  * This is a bit tricky because we have to make sure all dirty pages
1307  * have been sent off to the server before calling invalidate_inode_pages.
1308  * To make sure no other process adds more write requests while we try
1309  * our best to flush them, we make them sleep during the attribute refresh.
1310  *
1311  * A very similar scenario holds for the dir cache.
1312  */
1313 static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1314 {
1315 	struct nfs_server *server;
1316 	struct nfs_inode *nfsi = NFS_I(inode);
1317 	loff_t cur_isize, new_isize;
1318 	unsigned long invalid = 0;
1319 	unsigned long now = jiffies;
1320 	unsigned long save_cache_validity;
1321 
1322 	dfprintk(VFS, "NFS: %s(%s/%ld fh_crc=0x%08x ct=%d info=0x%x)\n",
1323 			__func__, inode->i_sb->s_id, inode->i_ino,
1324 			nfs_display_fhandle_hash(NFS_FH(inode)),
1325 			atomic_read(&inode->i_count), fattr->valid);
1326 
1327 	if ((fattr->valid & NFS_ATTR_FATTR_FILEID) && nfsi->fileid != fattr->fileid) {
1328 		printk(KERN_ERR "NFS: server %s error: fileid changed\n"
1329 			"fsid %s: expected fileid 0x%Lx, got 0x%Lx\n",
1330 			NFS_SERVER(inode)->nfs_client->cl_hostname,
1331 			inode->i_sb->s_id, (long long)nfsi->fileid,
1332 			(long long)fattr->fileid);
1333 		goto out_err;
1334 	}
1335 
1336 	/*
1337 	 * Make sure the inode's type hasn't changed.
1338 	 */
1339 	if ((fattr->valid & NFS_ATTR_FATTR_TYPE) && (inode->i_mode & S_IFMT) != (fattr->mode & S_IFMT)) {
1340 		/*
1341 		* Big trouble! The inode has become a different object.
1342 		*/
1343 		printk(KERN_DEBUG "NFS: %s: inode %ld mode changed, %07o to %07o\n",
1344 				__func__, inode->i_ino, inode->i_mode, fattr->mode);
1345 		goto out_err;
1346 	}
1347 
1348 	server = NFS_SERVER(inode);
1349 	/* Update the fsid? */
1350 	if (S_ISDIR(inode->i_mode) && (fattr->valid & NFS_ATTR_FATTR_FSID) &&
1351 			!nfs_fsid_equal(&server->fsid, &fattr->fsid) &&
1352 			!IS_AUTOMOUNT(inode))
1353 		server->fsid = fattr->fsid;
1354 
1355 	/*
1356 	 * Update the read time so we don't revalidate too often.
1357 	 */
1358 	nfsi->read_cache_jiffies = fattr->time_start;
1359 
1360 	save_cache_validity = nfsi->cache_validity;
1361 	nfsi->cache_validity &= ~(NFS_INO_INVALID_ATTR
1362 			| NFS_INO_INVALID_ATIME
1363 			| NFS_INO_REVAL_FORCED
1364 			| NFS_INO_REVAL_PAGECACHE);
1365 
1366 	/* Do atomic weak cache consistency updates */
1367 	invalid |= nfs_wcc_update_inode(inode, fattr);
1368 
1369 	/* More cache consistency checks */
1370 	if (fattr->valid & NFS_ATTR_FATTR_CHANGE) {
1371 		if (inode->i_version != fattr->change_attr) {
1372 			dprintk("NFS: change_attr change on server for file %s/%ld\n",
1373 					inode->i_sb->s_id, inode->i_ino);
1374 			invalid |= NFS_INO_INVALID_ATTR
1375 				| NFS_INO_INVALID_DATA
1376 				| NFS_INO_INVALID_ACCESS
1377 				| NFS_INO_INVALID_ACL
1378 				| NFS_INO_REVAL_PAGECACHE;
1379 			if (S_ISDIR(inode->i_mode))
1380 				nfs_force_lookup_revalidate(inode);
1381 			inode->i_version = fattr->change_attr;
1382 		}
1383 	} else if (server->caps & NFS_CAP_CHANGE_ATTR)
1384 		invalid |= save_cache_validity;
1385 
1386 	if (fattr->valid & NFS_ATTR_FATTR_MTIME) {
1387 		memcpy(&inode->i_mtime, &fattr->mtime, sizeof(inode->i_mtime));
1388 	} else if (server->caps & NFS_CAP_MTIME)
1389 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1390 				| NFS_INO_REVAL_FORCED);
1391 
1392 	if (fattr->valid & NFS_ATTR_FATTR_CTIME) {
1393 		memcpy(&inode->i_ctime, &fattr->ctime, sizeof(inode->i_ctime));
1394 	} else if (server->caps & NFS_CAP_CTIME)
1395 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1396 				| NFS_INO_REVAL_FORCED);
1397 
1398 	/* Check if our cached file size is stale */
1399 	if (fattr->valid & NFS_ATTR_FATTR_SIZE) {
1400 		new_isize = nfs_size_to_loff_t(fattr->size);
1401 		cur_isize = i_size_read(inode);
1402 		if (new_isize != cur_isize) {
1403 			/* Do we perhaps have any outstanding writes, or has
1404 			 * the file grown beyond our last write? */
1405 			if ((nfsi->npages == 0 && !test_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags)) ||
1406 			     new_isize > cur_isize) {
1407 				i_size_write(inode, new_isize);
1408 				invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA;
1409 			}
1410 			dprintk("NFS: isize change on server for file %s/%ld "
1411 					"(%Ld to %Ld)\n",
1412 					inode->i_sb->s_id,
1413 					inode->i_ino,
1414 					(long long)cur_isize,
1415 					(long long)new_isize);
1416 		}
1417 	} else
1418 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1419 				| NFS_INO_REVAL_PAGECACHE
1420 				| NFS_INO_REVAL_FORCED);
1421 
1422 
1423 	if (fattr->valid & NFS_ATTR_FATTR_ATIME)
1424 		memcpy(&inode->i_atime, &fattr->atime, sizeof(inode->i_atime));
1425 	else if (server->caps & NFS_CAP_ATIME)
1426 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATIME
1427 				| NFS_INO_REVAL_FORCED);
1428 
1429 	if (fattr->valid & NFS_ATTR_FATTR_MODE) {
1430 		if ((inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO)) {
1431 			umode_t newmode = inode->i_mode & S_IFMT;
1432 			newmode |= fattr->mode & S_IALLUGO;
1433 			inode->i_mode = newmode;
1434 			invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1435 		}
1436 	} else if (server->caps & NFS_CAP_MODE)
1437 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1438 				| NFS_INO_INVALID_ACCESS
1439 				| NFS_INO_INVALID_ACL
1440 				| NFS_INO_REVAL_FORCED);
1441 
1442 	if (fattr->valid & NFS_ATTR_FATTR_OWNER) {
1443 		if (inode->i_uid != fattr->uid) {
1444 			invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1445 			inode->i_uid = fattr->uid;
1446 		}
1447 	} else if (server->caps & NFS_CAP_OWNER)
1448 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1449 				| NFS_INO_INVALID_ACCESS
1450 				| NFS_INO_INVALID_ACL
1451 				| NFS_INO_REVAL_FORCED);
1452 
1453 	if (fattr->valid & NFS_ATTR_FATTR_GROUP) {
1454 		if (inode->i_gid != fattr->gid) {
1455 			invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1456 			inode->i_gid = fattr->gid;
1457 		}
1458 	} else if (server->caps & NFS_CAP_OWNER_GROUP)
1459 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1460 				| NFS_INO_INVALID_ACCESS
1461 				| NFS_INO_INVALID_ACL
1462 				| NFS_INO_REVAL_FORCED);
1463 
1464 	if (fattr->valid & NFS_ATTR_FATTR_NLINK) {
1465 		if (inode->i_nlink != fattr->nlink) {
1466 			invalid |= NFS_INO_INVALID_ATTR;
1467 			if (S_ISDIR(inode->i_mode))
1468 				invalid |= NFS_INO_INVALID_DATA;
1469 			set_nlink(inode, fattr->nlink);
1470 		}
1471 	} else if (server->caps & NFS_CAP_NLINK)
1472 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1473 				| NFS_INO_REVAL_FORCED);
1474 
1475 	if (fattr->valid & NFS_ATTR_FATTR_SPACE_USED) {
1476 		/*
1477 		 * report the blocks in 512byte units
1478 		 */
1479 		inode->i_blocks = nfs_calc_block_size(fattr->du.nfs3.used);
1480  	}
1481 	if (fattr->valid & NFS_ATTR_FATTR_BLOCKS_USED)
1482 		inode->i_blocks = fattr->du.nfs2.blocks;
1483 
1484 	/* Update attrtimeo value if we're out of the unstable period */
1485 	if (invalid & NFS_INO_INVALID_ATTR) {
1486 		nfs_inc_stats(inode, NFSIOS_ATTRINVALIDATE);
1487 		nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
1488 		nfsi->attrtimeo_timestamp = now;
1489 		nfsi->attr_gencount = nfs_inc_attr_generation_counter();
1490 	} else {
1491 		if (!time_in_range_open(now, nfsi->attrtimeo_timestamp, nfsi->attrtimeo_timestamp + nfsi->attrtimeo)) {
1492 			if ((nfsi->attrtimeo <<= 1) > NFS_MAXATTRTIMEO(inode))
1493 				nfsi->attrtimeo = NFS_MAXATTRTIMEO(inode);
1494 			nfsi->attrtimeo_timestamp = now;
1495 		}
1496 	}
1497 	invalid &= ~NFS_INO_INVALID_ATTR;
1498 	/* Don't invalidate the data if we were to blame */
1499 	if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)
1500 				|| S_ISLNK(inode->i_mode)))
1501 		invalid &= ~NFS_INO_INVALID_DATA;
1502 	if (!NFS_PROTO(inode)->have_delegation(inode, FMODE_READ) ||
1503 			(save_cache_validity & NFS_INO_REVAL_FORCED))
1504 		nfsi->cache_validity |= invalid;
1505 
1506 	if (invalid & NFS_INO_INVALID_DATA)
1507 		nfs_fscache_invalidate(inode);
1508 
1509 	return 0;
1510  out_err:
1511 	/*
1512 	 * No need to worry about unhashing the dentry, as the
1513 	 * lookup validation will know that the inode is bad.
1514 	 * (But we fall through to invalidate the caches.)
1515 	 */
1516 	nfs_invalidate_inode(inode);
1517 	return -ESTALE;
1518 }
1519 
1520 struct inode *nfs_alloc_inode(struct super_block *sb)
1521 {
1522 	struct nfs_inode *nfsi;
1523 	nfsi = (struct nfs_inode *)kmem_cache_alloc(nfs_inode_cachep, GFP_KERNEL);
1524 	if (!nfsi)
1525 		return NULL;
1526 	nfsi->flags = 0UL;
1527 	nfsi->cache_validity = 0UL;
1528 #ifdef CONFIG_NFS_V3_ACL
1529 	nfsi->acl_access = ERR_PTR(-EAGAIN);
1530 	nfsi->acl_default = ERR_PTR(-EAGAIN);
1531 #endif
1532 #if IS_ENABLED(CONFIG_NFS_V4)
1533 	nfsi->nfs4_acl = NULL;
1534 #endif /* CONFIG_NFS_V4 */
1535 	return &nfsi->vfs_inode;
1536 }
1537 EXPORT_SYMBOL_GPL(nfs_alloc_inode);
1538 
1539 static void nfs_i_callback(struct rcu_head *head)
1540 {
1541 	struct inode *inode = container_of(head, struct inode, i_rcu);
1542 	kmem_cache_free(nfs_inode_cachep, NFS_I(inode));
1543 }
1544 
1545 void nfs_destroy_inode(struct inode *inode)
1546 {
1547 	call_rcu(&inode->i_rcu, nfs_i_callback);
1548 }
1549 EXPORT_SYMBOL_GPL(nfs_destroy_inode);
1550 
1551 static inline void nfs4_init_once(struct nfs_inode *nfsi)
1552 {
1553 #if IS_ENABLED(CONFIG_NFS_V4)
1554 	INIT_LIST_HEAD(&nfsi->open_states);
1555 	nfsi->delegation = NULL;
1556 	nfsi->delegation_state = 0;
1557 	init_rwsem(&nfsi->rwsem);
1558 	nfsi->layout = NULL;
1559 #endif
1560 }
1561 
1562 static void init_once(void *foo)
1563 {
1564 	struct nfs_inode *nfsi = (struct nfs_inode *) foo;
1565 
1566 	inode_init_once(&nfsi->vfs_inode);
1567 	INIT_LIST_HEAD(&nfsi->open_files);
1568 	INIT_LIST_HEAD(&nfsi->access_cache_entry_lru);
1569 	INIT_LIST_HEAD(&nfsi->access_cache_inode_lru);
1570 	INIT_LIST_HEAD(&nfsi->commit_info.list);
1571 	nfsi->npages = 0;
1572 	nfsi->commit_info.ncommit = 0;
1573 	atomic_set(&nfsi->commit_info.rpcs_out, 0);
1574 	atomic_set(&nfsi->silly_count, 1);
1575 	INIT_HLIST_HEAD(&nfsi->silly_list);
1576 	init_waitqueue_head(&nfsi->waitqueue);
1577 	nfs4_init_once(nfsi);
1578 }
1579 
1580 static int __init nfs_init_inodecache(void)
1581 {
1582 	nfs_inode_cachep = kmem_cache_create("nfs_inode_cache",
1583 					     sizeof(struct nfs_inode),
1584 					     0, (SLAB_RECLAIM_ACCOUNT|
1585 						SLAB_MEM_SPREAD),
1586 					     init_once);
1587 	if (nfs_inode_cachep == NULL)
1588 		return -ENOMEM;
1589 
1590 	return 0;
1591 }
1592 
1593 static void nfs_destroy_inodecache(void)
1594 {
1595 	/*
1596 	 * Make sure all delayed rcu free inodes are flushed before we
1597 	 * destroy cache.
1598 	 */
1599 	rcu_barrier();
1600 	kmem_cache_destroy(nfs_inode_cachep);
1601 }
1602 
1603 struct workqueue_struct *nfsiod_workqueue;
1604 EXPORT_SYMBOL_GPL(nfsiod_workqueue);
1605 
1606 /*
1607  * start up the nfsiod workqueue
1608  */
1609 static int nfsiod_start(void)
1610 {
1611 	struct workqueue_struct *wq;
1612 	dprintk("RPC:       creating workqueue nfsiod\n");
1613 	wq = alloc_workqueue("nfsiod", WQ_MEM_RECLAIM, 0);
1614 	if (wq == NULL)
1615 		return -ENOMEM;
1616 	nfsiod_workqueue = wq;
1617 	return 0;
1618 }
1619 
1620 /*
1621  * Destroy the nfsiod workqueue
1622  */
1623 static void nfsiod_stop(void)
1624 {
1625 	struct workqueue_struct *wq;
1626 
1627 	wq = nfsiod_workqueue;
1628 	if (wq == NULL)
1629 		return;
1630 	nfsiod_workqueue = NULL;
1631 	destroy_workqueue(wq);
1632 }
1633 
1634 int nfs_net_id;
1635 EXPORT_SYMBOL_GPL(nfs_net_id);
1636 
1637 static int nfs_net_init(struct net *net)
1638 {
1639 	nfs_clients_init(net);
1640 	return nfs_dns_resolver_cache_init(net);
1641 }
1642 
1643 static void nfs_net_exit(struct net *net)
1644 {
1645 	nfs_dns_resolver_cache_destroy(net);
1646 	nfs_cleanup_cb_ident_idr(net);
1647 }
1648 
1649 static struct pernet_operations nfs_net_ops = {
1650 	.init = nfs_net_init,
1651 	.exit = nfs_net_exit,
1652 	.id   = &nfs_net_id,
1653 	.size = sizeof(struct nfs_net),
1654 };
1655 
1656 /*
1657  * Initialize NFS
1658  */
1659 static int __init init_nfs_fs(void)
1660 {
1661 	int err;
1662 
1663 	err = nfs_dns_resolver_init();
1664 	if (err < 0)
1665 		goto out10;;
1666 
1667 	err = register_pernet_subsys(&nfs_net_ops);
1668 	if (err < 0)
1669 		goto out9;
1670 
1671 	err = nfs_fscache_register();
1672 	if (err < 0)
1673 		goto out8;
1674 
1675 	err = nfsiod_start();
1676 	if (err)
1677 		goto out7;
1678 
1679 	err = nfs_fs_proc_init();
1680 	if (err)
1681 		goto out6;
1682 
1683 	err = nfs_init_nfspagecache();
1684 	if (err)
1685 		goto out5;
1686 
1687 	err = nfs_init_inodecache();
1688 	if (err)
1689 		goto out4;
1690 
1691 	err = nfs_init_readpagecache();
1692 	if (err)
1693 		goto out3;
1694 
1695 	err = nfs_init_writepagecache();
1696 	if (err)
1697 		goto out2;
1698 
1699 	err = nfs_init_directcache();
1700 	if (err)
1701 		goto out1;
1702 
1703 #ifdef CONFIG_PROC_FS
1704 	rpc_proc_register(&init_net, &nfs_rpcstat);
1705 #endif
1706 	if ((err = register_nfs_fs()) != 0)
1707 		goto out0;
1708 
1709 	return 0;
1710 out0:
1711 #ifdef CONFIG_PROC_FS
1712 	rpc_proc_unregister(&init_net, "nfs");
1713 #endif
1714 	nfs_destroy_directcache();
1715 out1:
1716 	nfs_destroy_writepagecache();
1717 out2:
1718 	nfs_destroy_readpagecache();
1719 out3:
1720 	nfs_destroy_inodecache();
1721 out4:
1722 	nfs_destroy_nfspagecache();
1723 out5:
1724 	nfs_fs_proc_exit();
1725 out6:
1726 	nfsiod_stop();
1727 out7:
1728 	nfs_fscache_unregister();
1729 out8:
1730 	unregister_pernet_subsys(&nfs_net_ops);
1731 out9:
1732 	nfs_dns_resolver_destroy();
1733 out10:
1734 	return err;
1735 }
1736 
1737 static void __exit exit_nfs_fs(void)
1738 {
1739 	nfs_destroy_directcache();
1740 	nfs_destroy_writepagecache();
1741 	nfs_destroy_readpagecache();
1742 	nfs_destroy_inodecache();
1743 	nfs_destroy_nfspagecache();
1744 	nfs_fscache_unregister();
1745 	unregister_pernet_subsys(&nfs_net_ops);
1746 	nfs_dns_resolver_destroy();
1747 #ifdef CONFIG_PROC_FS
1748 	rpc_proc_unregister(&init_net, "nfs");
1749 #endif
1750 	unregister_nfs_fs();
1751 	nfs_fs_proc_exit();
1752 	nfsiod_stop();
1753 }
1754 
1755 /* Not quite true; I just maintain it */
1756 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
1757 MODULE_LICENSE("GPL");
1758 module_param(enable_ino64, bool, 0644);
1759 
1760 module_init(init_nfs_fs)
1761 module_exit(exit_nfs_fs)
1762