xref: /linux/fs/nfs/inode.c (revision f884ab15afdc5514e88105c92a4e2e1e6539869a)
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 ((S_IFMT & inode->i_mode) != (S_IFMT & fattr->mode))
241 		return 0;
242 	if (nfs_compare_fh(NFS_FH(inode), fh))
243 		return 0;
244 	if (is_bad_inode(inode) || NFS_STALE(inode))
245 		return 0;
246 	return 1;
247 }
248 
249 static int
250 nfs_init_locked(struct inode *inode, void *opaque)
251 {
252 	struct nfs_find_desc	*desc = (struct nfs_find_desc *)opaque;
253 	struct nfs_fattr	*fattr = desc->fattr;
254 
255 	set_nfs_fileid(inode, fattr->fileid);
256 	nfs_copy_fh(NFS_FH(inode), desc->fh);
257 	return 0;
258 }
259 
260 /*
261  * This is our front-end to iget that looks up inodes by file handle
262  * instead of inode number.
263  */
264 struct inode *
265 nfs_fhget(struct super_block *sb, struct nfs_fh *fh, struct nfs_fattr *fattr)
266 {
267 	struct nfs_find_desc desc = {
268 		.fh	= fh,
269 		.fattr	= fattr
270 	};
271 	struct inode *inode = ERR_PTR(-ENOENT);
272 	unsigned long hash;
273 
274 	nfs_attr_check_mountpoint(sb, fattr);
275 
276 	if (((fattr->valid & NFS_ATTR_FATTR_FILEID) == 0) &&
277 	    !nfs_attr_use_mounted_on_fileid(fattr))
278 		goto out_no_inode;
279 	if ((fattr->valid & NFS_ATTR_FATTR_TYPE) == 0)
280 		goto out_no_inode;
281 
282 	hash = nfs_fattr_to_ino_t(fattr);
283 
284 	inode = iget5_locked(sb, hash, nfs_find_actor, nfs_init_locked, &desc);
285 	if (inode == NULL) {
286 		inode = ERR_PTR(-ENOMEM);
287 		goto out_no_inode;
288 	}
289 
290 	if (inode->i_state & I_NEW) {
291 		struct nfs_inode *nfsi = NFS_I(inode);
292 		unsigned long now = jiffies;
293 
294 		/* We set i_ino for the few things that still rely on it,
295 		 * such as stat(2) */
296 		inode->i_ino = hash;
297 
298 		/* We can't support update_atime(), since the server will reset it */
299 		inode->i_flags |= S_NOATIME|S_NOCMTIME;
300 		inode->i_mode = fattr->mode;
301 		if ((fattr->valid & NFS_ATTR_FATTR_MODE) == 0
302 				&& nfs_server_capable(inode, NFS_CAP_MODE))
303 			nfsi->cache_validity |= NFS_INO_INVALID_ATTR;
304 		/* Why so? Because we want revalidate for devices/FIFOs, and
305 		 * that's precisely what we have in nfs_file_inode_operations.
306 		 */
307 		inode->i_op = NFS_SB(sb)->nfs_client->rpc_ops->file_inode_ops;
308 		if (S_ISREG(inode->i_mode)) {
309 			inode->i_fop = NFS_SB(sb)->nfs_client->rpc_ops->file_ops;
310 			inode->i_data.a_ops = &nfs_file_aops;
311 			inode->i_data.backing_dev_info = &NFS_SB(sb)->backing_dev_info;
312 		} else if (S_ISDIR(inode->i_mode)) {
313 			inode->i_op = NFS_SB(sb)->nfs_client->rpc_ops->dir_inode_ops;
314 			inode->i_fop = &nfs_dir_operations;
315 			inode->i_data.a_ops = &nfs_dir_aops;
316 			/* Deal with crossing mountpoints */
317 			if (fattr->valid & NFS_ATTR_FATTR_MOUNTPOINT ||
318 					fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL) {
319 				if (fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL)
320 					inode->i_op = &nfs_referral_inode_operations;
321 				else
322 					inode->i_op = &nfs_mountpoint_inode_operations;
323 				inode->i_fop = NULL;
324 				inode->i_flags |= S_AUTOMOUNT;
325 			}
326 		} else if (S_ISLNK(inode->i_mode))
327 			inode->i_op = &nfs_symlink_inode_operations;
328 		else
329 			init_special_inode(inode, inode->i_mode, fattr->rdev);
330 
331 		memset(&inode->i_atime, 0, sizeof(inode->i_atime));
332 		memset(&inode->i_mtime, 0, sizeof(inode->i_mtime));
333 		memset(&inode->i_ctime, 0, sizeof(inode->i_ctime));
334 		inode->i_version = 0;
335 		inode->i_size = 0;
336 		clear_nlink(inode);
337 		inode->i_uid = make_kuid(&init_user_ns, -2);
338 		inode->i_gid = make_kgid(&init_user_ns, -2);
339 		inode->i_blocks = 0;
340 		memset(nfsi->cookieverf, 0, sizeof(nfsi->cookieverf));
341 		nfsi->write_io = 0;
342 		nfsi->read_io = 0;
343 
344 		nfsi->read_cache_jiffies = fattr->time_start;
345 		nfsi->attr_gencount = fattr->gencount;
346 		if (fattr->valid & NFS_ATTR_FATTR_ATIME)
347 			inode->i_atime = fattr->atime;
348 		else if (nfs_server_capable(inode, NFS_CAP_ATIME))
349 			nfsi->cache_validity |= NFS_INO_INVALID_ATTR;
350 		if (fattr->valid & NFS_ATTR_FATTR_MTIME)
351 			inode->i_mtime = fattr->mtime;
352 		else if (nfs_server_capable(inode, NFS_CAP_MTIME))
353 			nfsi->cache_validity |= NFS_INO_INVALID_ATTR;
354 		if (fattr->valid & NFS_ATTR_FATTR_CTIME)
355 			inode->i_ctime = fattr->ctime;
356 		else if (nfs_server_capable(inode, NFS_CAP_CTIME))
357 			nfsi->cache_validity |= NFS_INO_INVALID_ATTR;
358 		if (fattr->valid & NFS_ATTR_FATTR_CHANGE)
359 			inode->i_version = fattr->change_attr;
360 		else if (nfs_server_capable(inode, NFS_CAP_CHANGE_ATTR))
361 			nfsi->cache_validity |= NFS_INO_INVALID_ATTR;
362 		if (fattr->valid & NFS_ATTR_FATTR_SIZE)
363 			inode->i_size = nfs_size_to_loff_t(fattr->size);
364 		else
365 			nfsi->cache_validity |= NFS_INO_INVALID_ATTR
366 				| NFS_INO_REVAL_PAGECACHE;
367 		if (fattr->valid & NFS_ATTR_FATTR_NLINK)
368 			set_nlink(inode, fattr->nlink);
369 		else if (nfs_server_capable(inode, NFS_CAP_NLINK))
370 			nfsi->cache_validity |= NFS_INO_INVALID_ATTR;
371 		if (fattr->valid & NFS_ATTR_FATTR_OWNER)
372 			inode->i_uid = fattr->uid;
373 		else if (nfs_server_capable(inode, NFS_CAP_OWNER))
374 			nfsi->cache_validity |= NFS_INO_INVALID_ATTR;
375 		if (fattr->valid & NFS_ATTR_FATTR_GROUP)
376 			inode->i_gid = fattr->gid;
377 		else if (nfs_server_capable(inode, NFS_CAP_OWNER_GROUP))
378 			nfsi->cache_validity |= NFS_INO_INVALID_ATTR;
379 		if (fattr->valid & NFS_ATTR_FATTR_BLOCKS_USED)
380 			inode->i_blocks = fattr->du.nfs2.blocks;
381 		if (fattr->valid & NFS_ATTR_FATTR_SPACE_USED) {
382 			/*
383 			 * report the blocks in 512byte units
384 			 */
385 			inode->i_blocks = nfs_calc_block_size(fattr->du.nfs3.used);
386 		}
387 		nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
388 		nfsi->attrtimeo_timestamp = now;
389 		nfsi->access_cache = RB_ROOT;
390 
391 		nfs_fscache_init_inode_cookie(inode);
392 
393 		unlock_new_inode(inode);
394 	} else
395 		nfs_refresh_inode(inode, fattr);
396 	dprintk("NFS: nfs_fhget(%s/%Ld fh_crc=0x%08x ct=%d)\n",
397 		inode->i_sb->s_id,
398 		(long long)NFS_FILEID(inode),
399 		nfs_display_fhandle_hash(fh),
400 		atomic_read(&inode->i_count));
401 
402 out:
403 	return inode;
404 
405 out_no_inode:
406 	dprintk("nfs_fhget: iget failed with error %ld\n", PTR_ERR(inode));
407 	goto out;
408 }
409 EXPORT_SYMBOL_GPL(nfs_fhget);
410 
411 #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)
412 
413 int
414 nfs_setattr(struct dentry *dentry, struct iattr *attr)
415 {
416 	struct inode *inode = dentry->d_inode;
417 	struct nfs_fattr *fattr;
418 	int error = -ENOMEM;
419 
420 	nfs_inc_stats(inode, NFSIOS_VFSSETATTR);
421 
422 	/* skip mode change if it's just for clearing setuid/setgid */
423 	if (attr->ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
424 		attr->ia_valid &= ~ATTR_MODE;
425 
426 	if (attr->ia_valid & ATTR_SIZE) {
427 		if (!S_ISREG(inode->i_mode) || attr->ia_size == i_size_read(inode))
428 			attr->ia_valid &= ~ATTR_SIZE;
429 	}
430 
431 	/* Optimization: if the end result is no change, don't RPC */
432 	attr->ia_valid &= NFS_VALID_ATTRS;
433 	if ((attr->ia_valid & ~(ATTR_FILE|ATTR_OPEN)) == 0)
434 		return 0;
435 
436 	/* Write all dirty data */
437 	if (S_ISREG(inode->i_mode)) {
438 		nfs_inode_dio_wait(inode);
439 		nfs_wb_all(inode);
440 	}
441 
442 	fattr = nfs_alloc_fattr();
443 	if (fattr == NULL)
444 		goto out;
445 	/*
446 	 * Return any delegations if we're going to change ACLs
447 	 */
448 	if ((attr->ia_valid & (ATTR_MODE|ATTR_UID|ATTR_GID)) != 0)
449 		NFS_PROTO(inode)->return_delegation(inode);
450 	error = NFS_PROTO(inode)->setattr(dentry, fattr, attr);
451 	if (error == 0)
452 		nfs_refresh_inode(inode, fattr);
453 	nfs_free_fattr(fattr);
454 out:
455 	return error;
456 }
457 EXPORT_SYMBOL_GPL(nfs_setattr);
458 
459 /**
460  * nfs_vmtruncate - unmap mappings "freed" by truncate() syscall
461  * @inode: inode of the file used
462  * @offset: file offset to start truncating
463  *
464  * This is a copy of the common vmtruncate, but with the locking
465  * corrected to take into account the fact that NFS requires
466  * inode->i_size to be updated under the inode->i_lock.
467  */
468 static int nfs_vmtruncate(struct inode * inode, loff_t offset)
469 {
470 	loff_t oldsize;
471 	int err;
472 
473 	err = inode_newsize_ok(inode, offset);
474 	if (err)
475 		goto out;
476 
477 	spin_lock(&inode->i_lock);
478 	oldsize = inode->i_size;
479 	i_size_write(inode, offset);
480 	spin_unlock(&inode->i_lock);
481 
482 	truncate_pagecache(inode, oldsize, offset);
483 out:
484 	return err;
485 }
486 
487 /**
488  * nfs_setattr_update_inode - Update inode metadata after a setattr call.
489  * @inode: pointer to struct inode
490  * @attr: pointer to struct iattr
491  *
492  * Note: we do this in the *proc.c in order to ensure that
493  *       it works for things like exclusive creates too.
494  */
495 void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr)
496 {
497 	if ((attr->ia_valid & (ATTR_MODE|ATTR_UID|ATTR_GID)) != 0) {
498 		spin_lock(&inode->i_lock);
499 		if ((attr->ia_valid & ATTR_MODE) != 0) {
500 			int mode = attr->ia_mode & S_IALLUGO;
501 			mode |= inode->i_mode & ~S_IALLUGO;
502 			inode->i_mode = mode;
503 		}
504 		if ((attr->ia_valid & ATTR_UID) != 0)
505 			inode->i_uid = attr->ia_uid;
506 		if ((attr->ia_valid & ATTR_GID) != 0)
507 			inode->i_gid = attr->ia_gid;
508 		NFS_I(inode)->cache_validity |= NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
509 		spin_unlock(&inode->i_lock);
510 	}
511 	if ((attr->ia_valid & ATTR_SIZE) != 0) {
512 		nfs_inc_stats(inode, NFSIOS_SETATTRTRUNC);
513 		nfs_vmtruncate(inode, attr->ia_size);
514 	}
515 }
516 EXPORT_SYMBOL_GPL(nfs_setattr_update_inode);
517 
518 int nfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
519 {
520 	struct inode *inode = dentry->d_inode;
521 	int need_atime = NFS_I(inode)->cache_validity & NFS_INO_INVALID_ATIME;
522 	int err;
523 
524 	/* Flush out writes to the server in order to update c/mtime.  */
525 	if (S_ISREG(inode->i_mode)) {
526 		nfs_inode_dio_wait(inode);
527 		err = filemap_write_and_wait(inode->i_mapping);
528 		if (err)
529 			goto out;
530 	}
531 
532 	/*
533 	 * We may force a getattr if the user cares about atime.
534 	 *
535 	 * Note that we only have to check the vfsmount flags here:
536 	 *  - NFS always sets S_NOATIME by so checking it would give a
537 	 *    bogus result
538 	 *  - NFS never sets MS_NOATIME or MS_NODIRATIME so there is
539 	 *    no point in checking those.
540 	 */
541  	if ((mnt->mnt_flags & MNT_NOATIME) ||
542  	    ((mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode)))
543 		need_atime = 0;
544 
545 	if (need_atime)
546 		err = __nfs_revalidate_inode(NFS_SERVER(inode), inode);
547 	else
548 		err = nfs_revalidate_inode(NFS_SERVER(inode), inode);
549 	if (!err) {
550 		generic_fillattr(inode, stat);
551 		stat->ino = nfs_compat_user_ino64(NFS_FILEID(inode));
552 	}
553 out:
554 	return err;
555 }
556 EXPORT_SYMBOL_GPL(nfs_getattr);
557 
558 static void nfs_init_lock_context(struct nfs_lock_context *l_ctx)
559 {
560 	atomic_set(&l_ctx->count, 1);
561 	l_ctx->lockowner.l_owner = current->files;
562 	l_ctx->lockowner.l_pid = current->tgid;
563 	INIT_LIST_HEAD(&l_ctx->list);
564 	nfs_iocounter_init(&l_ctx->io_count);
565 }
566 
567 static struct nfs_lock_context *__nfs_find_lock_context(struct nfs_open_context *ctx)
568 {
569 	struct nfs_lock_context *head = &ctx->lock_context;
570 	struct nfs_lock_context *pos = head;
571 
572 	do {
573 		if (pos->lockowner.l_owner != current->files)
574 			continue;
575 		if (pos->lockowner.l_pid != current->tgid)
576 			continue;
577 		atomic_inc(&pos->count);
578 		return pos;
579 	} while ((pos = list_entry(pos->list.next, typeof(*pos), list)) != head);
580 	return NULL;
581 }
582 
583 struct nfs_lock_context *nfs_get_lock_context(struct nfs_open_context *ctx)
584 {
585 	struct nfs_lock_context *res, *new = NULL;
586 	struct inode *inode = ctx->dentry->d_inode;
587 
588 	spin_lock(&inode->i_lock);
589 	res = __nfs_find_lock_context(ctx);
590 	if (res == NULL) {
591 		spin_unlock(&inode->i_lock);
592 		new = kmalloc(sizeof(*new), GFP_KERNEL);
593 		if (new == NULL)
594 			return ERR_PTR(-ENOMEM);
595 		nfs_init_lock_context(new);
596 		spin_lock(&inode->i_lock);
597 		res = __nfs_find_lock_context(ctx);
598 		if (res == NULL) {
599 			list_add_tail(&new->list, &ctx->lock_context.list);
600 			new->open_context = ctx;
601 			res = new;
602 			new = NULL;
603 		}
604 	}
605 	spin_unlock(&inode->i_lock);
606 	kfree(new);
607 	return res;
608 }
609 
610 void nfs_put_lock_context(struct nfs_lock_context *l_ctx)
611 {
612 	struct nfs_open_context *ctx = l_ctx->open_context;
613 	struct inode *inode = ctx->dentry->d_inode;
614 
615 	if (!atomic_dec_and_lock(&l_ctx->count, &inode->i_lock))
616 		return;
617 	list_del(&l_ctx->list);
618 	spin_unlock(&inode->i_lock);
619 	kfree(l_ctx);
620 }
621 
622 /**
623  * nfs_close_context - Common close_context() routine NFSv2/v3
624  * @ctx: pointer to context
625  * @is_sync: is this a synchronous close
626  *
627  * always ensure that the attributes are up to date if we're mounted
628  * with close-to-open semantics
629  */
630 void nfs_close_context(struct nfs_open_context *ctx, int is_sync)
631 {
632 	struct inode *inode;
633 	struct nfs_server *server;
634 
635 	if (!(ctx->mode & FMODE_WRITE))
636 		return;
637 	if (!is_sync)
638 		return;
639 	inode = ctx->dentry->d_inode;
640 	if (!list_empty(&NFS_I(inode)->open_files))
641 		return;
642 	server = NFS_SERVER(inode);
643 	if (server->flags & NFS_MOUNT_NOCTO)
644 		return;
645 	nfs_revalidate_inode(server, inode);
646 }
647 EXPORT_SYMBOL_GPL(nfs_close_context);
648 
649 struct nfs_open_context *alloc_nfs_open_context(struct dentry *dentry, fmode_t f_mode)
650 {
651 	struct nfs_open_context *ctx;
652 	struct rpc_cred *cred = rpc_lookup_cred();
653 	if (IS_ERR(cred))
654 		return ERR_CAST(cred);
655 
656 	ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
657 	if (!ctx) {
658 		put_rpccred(cred);
659 		return ERR_PTR(-ENOMEM);
660 	}
661 	nfs_sb_active(dentry->d_sb);
662 	ctx->dentry = dget(dentry);
663 	ctx->cred = cred;
664 	ctx->state = NULL;
665 	ctx->mode = f_mode;
666 	ctx->flags = 0;
667 	ctx->error = 0;
668 	nfs_init_lock_context(&ctx->lock_context);
669 	ctx->lock_context.open_context = ctx;
670 	INIT_LIST_HEAD(&ctx->list);
671 	ctx->mdsthreshold = NULL;
672 	return ctx;
673 }
674 EXPORT_SYMBOL_GPL(alloc_nfs_open_context);
675 
676 struct nfs_open_context *get_nfs_open_context(struct nfs_open_context *ctx)
677 {
678 	if (ctx != NULL)
679 		atomic_inc(&ctx->lock_context.count);
680 	return ctx;
681 }
682 EXPORT_SYMBOL_GPL(get_nfs_open_context);
683 
684 static void __put_nfs_open_context(struct nfs_open_context *ctx, int is_sync)
685 {
686 	struct inode *inode = ctx->dentry->d_inode;
687 	struct super_block *sb = ctx->dentry->d_sb;
688 
689 	if (!list_empty(&ctx->list)) {
690 		if (!atomic_dec_and_lock(&ctx->lock_context.count, &inode->i_lock))
691 			return;
692 		list_del(&ctx->list);
693 		spin_unlock(&inode->i_lock);
694 	} else if (!atomic_dec_and_test(&ctx->lock_context.count))
695 		return;
696 	if (inode != NULL)
697 		NFS_PROTO(inode)->close_context(ctx, is_sync);
698 	if (ctx->cred != NULL)
699 		put_rpccred(ctx->cred);
700 	dput(ctx->dentry);
701 	nfs_sb_deactive(sb);
702 	kfree(ctx->mdsthreshold);
703 	kfree(ctx);
704 }
705 
706 void put_nfs_open_context(struct nfs_open_context *ctx)
707 {
708 	__put_nfs_open_context(ctx, 0);
709 }
710 EXPORT_SYMBOL_GPL(put_nfs_open_context);
711 
712 /*
713  * Ensure that mmap has a recent RPC credential for use when writing out
714  * shared pages
715  */
716 void nfs_file_set_open_context(struct file *filp, struct nfs_open_context *ctx)
717 {
718 	struct inode *inode = file_inode(filp);
719 	struct nfs_inode *nfsi = NFS_I(inode);
720 
721 	filp->private_data = get_nfs_open_context(ctx);
722 	spin_lock(&inode->i_lock);
723 	list_add(&ctx->list, &nfsi->open_files);
724 	spin_unlock(&inode->i_lock);
725 }
726 EXPORT_SYMBOL_GPL(nfs_file_set_open_context);
727 
728 /*
729  * Given an inode, search for an open context with the desired characteristics
730  */
731 struct nfs_open_context *nfs_find_open_context(struct inode *inode, struct rpc_cred *cred, fmode_t mode)
732 {
733 	struct nfs_inode *nfsi = NFS_I(inode);
734 	struct nfs_open_context *pos, *ctx = NULL;
735 
736 	spin_lock(&inode->i_lock);
737 	list_for_each_entry(pos, &nfsi->open_files, list) {
738 		if (cred != NULL && pos->cred != cred)
739 			continue;
740 		if ((pos->mode & (FMODE_READ|FMODE_WRITE)) != mode)
741 			continue;
742 		ctx = get_nfs_open_context(pos);
743 		break;
744 	}
745 	spin_unlock(&inode->i_lock);
746 	return ctx;
747 }
748 
749 static void nfs_file_clear_open_context(struct file *filp)
750 {
751 	struct inode *inode = file_inode(filp);
752 	struct nfs_open_context *ctx = nfs_file_open_context(filp);
753 
754 	if (ctx) {
755 		filp->private_data = NULL;
756 		spin_lock(&inode->i_lock);
757 		list_move_tail(&ctx->list, &NFS_I(inode)->open_files);
758 		spin_unlock(&inode->i_lock);
759 		__put_nfs_open_context(ctx, filp->f_flags & O_DIRECT ? 0 : 1);
760 	}
761 }
762 
763 /*
764  * These allocate and release file read/write context information.
765  */
766 int nfs_open(struct inode *inode, struct file *filp)
767 {
768 	struct nfs_open_context *ctx;
769 
770 	ctx = alloc_nfs_open_context(filp->f_path.dentry, filp->f_mode);
771 	if (IS_ERR(ctx))
772 		return PTR_ERR(ctx);
773 	nfs_file_set_open_context(filp, ctx);
774 	put_nfs_open_context(ctx);
775 	nfs_fscache_set_inode_cookie(inode, filp);
776 	return 0;
777 }
778 
779 int nfs_release(struct inode *inode, struct file *filp)
780 {
781 	nfs_file_clear_open_context(filp);
782 	return 0;
783 }
784 
785 /*
786  * This function is called whenever some part of NFS notices that
787  * the cached attributes have to be refreshed.
788  */
789 int
790 __nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
791 {
792 	int		 status = -ESTALE;
793 	struct nfs_fattr *fattr = NULL;
794 	struct nfs_inode *nfsi = NFS_I(inode);
795 
796 	dfprintk(PAGECACHE, "NFS: revalidating (%s/%Ld)\n",
797 		inode->i_sb->s_id, (long long)NFS_FILEID(inode));
798 
799 	if (is_bad_inode(inode))
800 		goto out;
801 	if (NFS_STALE(inode))
802 		goto out;
803 
804 	status = -ENOMEM;
805 	fattr = nfs_alloc_fattr();
806 	if (fattr == NULL)
807 		goto out;
808 
809 	nfs_inc_stats(inode, NFSIOS_INODEREVALIDATE);
810 	status = NFS_PROTO(inode)->getattr(server, NFS_FH(inode), fattr);
811 	if (status != 0) {
812 		dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Ld) getattr failed, error=%d\n",
813 			 inode->i_sb->s_id,
814 			 (long long)NFS_FILEID(inode), status);
815 		if (status == -ESTALE) {
816 			nfs_zap_caches(inode);
817 			if (!S_ISDIR(inode->i_mode))
818 				set_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
819 		}
820 		goto out;
821 	}
822 
823 	status = nfs_refresh_inode(inode, fattr);
824 	if (status) {
825 		dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Ld) refresh failed, error=%d\n",
826 			 inode->i_sb->s_id,
827 			 (long long)NFS_FILEID(inode), status);
828 		goto out;
829 	}
830 
831 	if (nfsi->cache_validity & NFS_INO_INVALID_ACL)
832 		nfs_zap_acl_cache(inode);
833 
834 	dfprintk(PAGECACHE, "NFS: (%s/%Ld) revalidation complete\n",
835 		inode->i_sb->s_id,
836 		(long long)NFS_FILEID(inode));
837 
838  out:
839 	nfs_free_fattr(fattr);
840 	return status;
841 }
842 
843 int nfs_attribute_timeout(struct inode *inode)
844 {
845 	struct nfs_inode *nfsi = NFS_I(inode);
846 
847 	return !time_in_range_open(jiffies, nfsi->read_cache_jiffies, nfsi->read_cache_jiffies + nfsi->attrtimeo);
848 }
849 
850 static int nfs_attribute_cache_expired(struct inode *inode)
851 {
852 	if (nfs_have_delegated_attributes(inode))
853 		return 0;
854 	return nfs_attribute_timeout(inode);
855 }
856 
857 /**
858  * nfs_revalidate_inode - Revalidate the inode attributes
859  * @server - pointer to nfs_server struct
860  * @inode - pointer to inode struct
861  *
862  * Updates inode attribute information by retrieving the data from the server.
863  */
864 int nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
865 {
866 	if (!(NFS_I(inode)->cache_validity & NFS_INO_INVALID_ATTR)
867 			&& !nfs_attribute_cache_expired(inode))
868 		return NFS_STALE(inode) ? -ESTALE : 0;
869 	return __nfs_revalidate_inode(server, inode);
870 }
871 EXPORT_SYMBOL_GPL(nfs_revalidate_inode);
872 
873 static int nfs_invalidate_mapping(struct inode *inode, struct address_space *mapping)
874 {
875 	struct nfs_inode *nfsi = NFS_I(inode);
876 
877 	if (mapping->nrpages != 0) {
878 		int ret = invalidate_inode_pages2(mapping);
879 		if (ret < 0)
880 			return ret;
881 	}
882 	spin_lock(&inode->i_lock);
883 	nfsi->cache_validity &= ~NFS_INO_INVALID_DATA;
884 	if (S_ISDIR(inode->i_mode))
885 		memset(nfsi->cookieverf, 0, sizeof(nfsi->cookieverf));
886 	spin_unlock(&inode->i_lock);
887 	nfs_inc_stats(inode, NFSIOS_DATAINVALIDATE);
888 	nfs_fscache_wait_on_invalidate(inode);
889 	dfprintk(PAGECACHE, "NFS: (%s/%Ld) data cache invalidated\n",
890 			inode->i_sb->s_id, (long long)NFS_FILEID(inode));
891 	return 0;
892 }
893 
894 static bool nfs_mapping_need_revalidate_inode(struct inode *inode)
895 {
896 	if (nfs_have_delegated_attributes(inode))
897 		return false;
898 	return (NFS_I(inode)->cache_validity & NFS_INO_REVAL_PAGECACHE)
899 		|| nfs_attribute_timeout(inode)
900 		|| NFS_STALE(inode);
901 }
902 
903 /**
904  * nfs_revalidate_mapping - Revalidate the pagecache
905  * @inode - pointer to host inode
906  * @mapping - pointer to mapping
907  */
908 int nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping)
909 {
910 	struct nfs_inode *nfsi = NFS_I(inode);
911 	int ret = 0;
912 
913 	/* swapfiles are not supposed to be shared. */
914 	if (IS_SWAPFILE(inode))
915 		goto out;
916 
917 	if (nfs_mapping_need_revalidate_inode(inode)) {
918 		ret = __nfs_revalidate_inode(NFS_SERVER(inode), inode);
919 		if (ret < 0)
920 			goto out;
921 	}
922 	if (nfsi->cache_validity & NFS_INO_INVALID_DATA)
923 		ret = nfs_invalidate_mapping(inode, mapping);
924 out:
925 	return ret;
926 }
927 
928 static unsigned long nfs_wcc_update_inode(struct inode *inode, struct nfs_fattr *fattr)
929 {
930 	struct nfs_inode *nfsi = NFS_I(inode);
931 	unsigned long ret = 0;
932 
933 	if ((fattr->valid & NFS_ATTR_FATTR_PRECHANGE)
934 			&& (fattr->valid & NFS_ATTR_FATTR_CHANGE)
935 			&& inode->i_version == fattr->pre_change_attr) {
936 		inode->i_version = fattr->change_attr;
937 		if (S_ISDIR(inode->i_mode))
938 			nfsi->cache_validity |= NFS_INO_INVALID_DATA;
939 		ret |= NFS_INO_INVALID_ATTR;
940 	}
941 	/* If we have atomic WCC data, we may update some attributes */
942 	if ((fattr->valid & NFS_ATTR_FATTR_PRECTIME)
943 			&& (fattr->valid & NFS_ATTR_FATTR_CTIME)
944 			&& timespec_equal(&inode->i_ctime, &fattr->pre_ctime)) {
945 		memcpy(&inode->i_ctime, &fattr->ctime, sizeof(inode->i_ctime));
946 		ret |= NFS_INO_INVALID_ATTR;
947 	}
948 
949 	if ((fattr->valid & NFS_ATTR_FATTR_PREMTIME)
950 			&& (fattr->valid & NFS_ATTR_FATTR_MTIME)
951 			&& timespec_equal(&inode->i_mtime, &fattr->pre_mtime)) {
952 		memcpy(&inode->i_mtime, &fattr->mtime, sizeof(inode->i_mtime));
953 		if (S_ISDIR(inode->i_mode))
954 			nfsi->cache_validity |= NFS_INO_INVALID_DATA;
955 		ret |= NFS_INO_INVALID_ATTR;
956 	}
957 	if ((fattr->valid & NFS_ATTR_FATTR_PRESIZE)
958 			&& (fattr->valid & NFS_ATTR_FATTR_SIZE)
959 			&& i_size_read(inode) == nfs_size_to_loff_t(fattr->pre_size)
960 			&& nfsi->npages == 0) {
961 		i_size_write(inode, nfs_size_to_loff_t(fattr->size));
962 		ret |= NFS_INO_INVALID_ATTR;
963 	}
964 
965 	if (nfsi->cache_validity & NFS_INO_INVALID_DATA)
966 		nfs_fscache_invalidate(inode);
967 
968 	return ret;
969 }
970 
971 /**
972  * nfs_check_inode_attributes - verify consistency of the inode attribute cache
973  * @inode - pointer to inode
974  * @fattr - updated attributes
975  *
976  * Verifies the attribute cache. If we have just changed the attributes,
977  * so that fattr carries weak cache consistency data, then it may
978  * also update the ctime/mtime/change_attribute.
979  */
980 static int nfs_check_inode_attributes(struct inode *inode, struct nfs_fattr *fattr)
981 {
982 	struct nfs_inode *nfsi = NFS_I(inode);
983 	loff_t cur_size, new_isize;
984 	unsigned long invalid = 0;
985 
986 
987 	if (nfs_have_delegated_attributes(inode))
988 		return 0;
989 	/* Has the inode gone and changed behind our back? */
990 	if ((fattr->valid & NFS_ATTR_FATTR_FILEID) && nfsi->fileid != fattr->fileid)
991 		return -EIO;
992 	if ((fattr->valid & NFS_ATTR_FATTR_TYPE) && (inode->i_mode & S_IFMT) != (fattr->mode & S_IFMT))
993 		return -EIO;
994 
995 	if ((fattr->valid & NFS_ATTR_FATTR_CHANGE) != 0 &&
996 			inode->i_version != fattr->change_attr)
997 		invalid |= NFS_INO_INVALID_ATTR|NFS_INO_REVAL_PAGECACHE;
998 
999 	/* Verify a few of the more important attributes */
1000 	if ((fattr->valid & NFS_ATTR_FATTR_MTIME) && !timespec_equal(&inode->i_mtime, &fattr->mtime))
1001 		invalid |= NFS_INO_INVALID_ATTR;
1002 
1003 	if (fattr->valid & NFS_ATTR_FATTR_SIZE) {
1004 		cur_size = i_size_read(inode);
1005 		new_isize = nfs_size_to_loff_t(fattr->size);
1006 		if (cur_size != new_isize && nfsi->npages == 0)
1007 			invalid |= NFS_INO_INVALID_ATTR|NFS_INO_REVAL_PAGECACHE;
1008 	}
1009 
1010 	/* Have any file permissions changed? */
1011 	if ((fattr->valid & NFS_ATTR_FATTR_MODE) && (inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO))
1012 		invalid |= NFS_INO_INVALID_ATTR | NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL;
1013 	if ((fattr->valid & NFS_ATTR_FATTR_OWNER) && !uid_eq(inode->i_uid, fattr->uid))
1014 		invalid |= NFS_INO_INVALID_ATTR | NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL;
1015 	if ((fattr->valid & NFS_ATTR_FATTR_GROUP) && !gid_eq(inode->i_gid, fattr->gid))
1016 		invalid |= NFS_INO_INVALID_ATTR | NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL;
1017 
1018 	/* Has the link count changed? */
1019 	if ((fattr->valid & NFS_ATTR_FATTR_NLINK) && inode->i_nlink != fattr->nlink)
1020 		invalid |= NFS_INO_INVALID_ATTR;
1021 
1022 	if ((fattr->valid & NFS_ATTR_FATTR_ATIME) && !timespec_equal(&inode->i_atime, &fattr->atime))
1023 		invalid |= NFS_INO_INVALID_ATIME;
1024 
1025 	if (invalid != 0)
1026 		nfsi->cache_validity |= invalid;
1027 
1028 	nfsi->read_cache_jiffies = fattr->time_start;
1029 	return 0;
1030 }
1031 
1032 static int nfs_ctime_need_update(const struct inode *inode, const struct nfs_fattr *fattr)
1033 {
1034 	if (!(fattr->valid & NFS_ATTR_FATTR_CTIME))
1035 		return 0;
1036 	return timespec_compare(&fattr->ctime, &inode->i_ctime) > 0;
1037 }
1038 
1039 static int nfs_size_need_update(const struct inode *inode, const struct nfs_fattr *fattr)
1040 {
1041 	if (!(fattr->valid & NFS_ATTR_FATTR_SIZE))
1042 		return 0;
1043 	return nfs_size_to_loff_t(fattr->size) > i_size_read(inode);
1044 }
1045 
1046 static atomic_long_t nfs_attr_generation_counter;
1047 
1048 static unsigned long nfs_read_attr_generation_counter(void)
1049 {
1050 	return atomic_long_read(&nfs_attr_generation_counter);
1051 }
1052 
1053 unsigned long nfs_inc_attr_generation_counter(void)
1054 {
1055 	return atomic_long_inc_return(&nfs_attr_generation_counter);
1056 }
1057 
1058 void nfs_fattr_init(struct nfs_fattr *fattr)
1059 {
1060 	fattr->valid = 0;
1061 	fattr->time_start = jiffies;
1062 	fattr->gencount = nfs_inc_attr_generation_counter();
1063 	fattr->owner_name = NULL;
1064 	fattr->group_name = NULL;
1065 }
1066 EXPORT_SYMBOL_GPL(nfs_fattr_init);
1067 
1068 struct nfs_fattr *nfs_alloc_fattr(void)
1069 {
1070 	struct nfs_fattr *fattr;
1071 
1072 	fattr = kmalloc(sizeof(*fattr), GFP_NOFS);
1073 	if (fattr != NULL)
1074 		nfs_fattr_init(fattr);
1075 	return fattr;
1076 }
1077 EXPORT_SYMBOL_GPL(nfs_alloc_fattr);
1078 
1079 struct nfs_fh *nfs_alloc_fhandle(void)
1080 {
1081 	struct nfs_fh *fh;
1082 
1083 	fh = kmalloc(sizeof(struct nfs_fh), GFP_NOFS);
1084 	if (fh != NULL)
1085 		fh->size = 0;
1086 	return fh;
1087 }
1088 EXPORT_SYMBOL_GPL(nfs_alloc_fhandle);
1089 
1090 #ifdef NFS_DEBUG
1091 /*
1092  * _nfs_display_fhandle_hash - calculate the crc32 hash for the filehandle
1093  *                             in the same way that wireshark does
1094  *
1095  * @fh: file handle
1096  *
1097  * For debugging only.
1098  */
1099 u32 _nfs_display_fhandle_hash(const struct nfs_fh *fh)
1100 {
1101 	/* wireshark uses 32-bit AUTODIN crc and does a bitwise
1102 	 * not on the result */
1103 	return ~crc32(0xFFFFFFFF, &fh->data[0], fh->size);
1104 }
1105 
1106 /*
1107  * _nfs_display_fhandle - display an NFS file handle on the console
1108  *
1109  * @fh: file handle to display
1110  * @caption: display caption
1111  *
1112  * For debugging only.
1113  */
1114 void _nfs_display_fhandle(const struct nfs_fh *fh, const char *caption)
1115 {
1116 	unsigned short i;
1117 
1118 	if (fh == NULL || fh->size == 0) {
1119 		printk(KERN_DEFAULT "%s at %p is empty\n", caption, fh);
1120 		return;
1121 	}
1122 
1123 	printk(KERN_DEFAULT "%s at %p is %u bytes, crc: 0x%08x:\n",
1124 	       caption, fh, fh->size, _nfs_display_fhandle_hash(fh));
1125 	for (i = 0; i < fh->size; i += 16) {
1126 		__be32 *pos = (__be32 *)&fh->data[i];
1127 
1128 		switch ((fh->size - i - 1) >> 2) {
1129 		case 0:
1130 			printk(KERN_DEFAULT " %08x\n",
1131 				be32_to_cpup(pos));
1132 			break;
1133 		case 1:
1134 			printk(KERN_DEFAULT " %08x %08x\n",
1135 				be32_to_cpup(pos), be32_to_cpup(pos + 1));
1136 			break;
1137 		case 2:
1138 			printk(KERN_DEFAULT " %08x %08x %08x\n",
1139 				be32_to_cpup(pos), be32_to_cpup(pos + 1),
1140 				be32_to_cpup(pos + 2));
1141 			break;
1142 		default:
1143 			printk(KERN_DEFAULT " %08x %08x %08x %08x\n",
1144 				be32_to_cpup(pos), be32_to_cpup(pos + 1),
1145 				be32_to_cpup(pos + 2), be32_to_cpup(pos + 3));
1146 		}
1147 	}
1148 }
1149 #endif
1150 
1151 /**
1152  * nfs_inode_attrs_need_update - check if the inode attributes need updating
1153  * @inode - pointer to inode
1154  * @fattr - attributes
1155  *
1156  * Attempt to divine whether or not an RPC call reply carrying stale
1157  * attributes got scheduled after another call carrying updated ones.
1158  *
1159  * To do so, the function first assumes that a more recent ctime means
1160  * that the attributes in fattr are newer, however it also attempt to
1161  * catch the case where ctime either didn't change, or went backwards
1162  * (if someone reset the clock on the server) by looking at whether
1163  * or not this RPC call was started after the inode was last updated.
1164  * Note also the check for wraparound of 'attr_gencount'
1165  *
1166  * The function returns 'true' if it thinks the attributes in 'fattr' are
1167  * more recent than the ones cached in the inode.
1168  *
1169  */
1170 static int nfs_inode_attrs_need_update(const struct inode *inode, const struct nfs_fattr *fattr)
1171 {
1172 	const struct nfs_inode *nfsi = NFS_I(inode);
1173 
1174 	return ((long)fattr->gencount - (long)nfsi->attr_gencount) > 0 ||
1175 		nfs_ctime_need_update(inode, fattr) ||
1176 		nfs_size_need_update(inode, fattr) ||
1177 		((long)nfsi->attr_gencount - (long)nfs_read_attr_generation_counter() > 0);
1178 }
1179 
1180 static int nfs_refresh_inode_locked(struct inode *inode, struct nfs_fattr *fattr)
1181 {
1182 	if (nfs_inode_attrs_need_update(inode, fattr))
1183 		return nfs_update_inode(inode, fattr);
1184 	return nfs_check_inode_attributes(inode, fattr);
1185 }
1186 
1187 /**
1188  * nfs_refresh_inode - try to update the inode attribute cache
1189  * @inode - pointer to inode
1190  * @fattr - updated attributes
1191  *
1192  * Check that an RPC call that returned attributes has not overlapped with
1193  * other recent updates of the inode metadata, then decide whether it is
1194  * safe to do a full update of the inode attributes, or whether just to
1195  * call nfs_check_inode_attributes.
1196  */
1197 int nfs_refresh_inode(struct inode *inode, struct nfs_fattr *fattr)
1198 {
1199 	int status;
1200 
1201 	if ((fattr->valid & NFS_ATTR_FATTR) == 0)
1202 		return 0;
1203 	spin_lock(&inode->i_lock);
1204 	status = nfs_refresh_inode_locked(inode, fattr);
1205 	spin_unlock(&inode->i_lock);
1206 
1207 	return status;
1208 }
1209 EXPORT_SYMBOL_GPL(nfs_refresh_inode);
1210 
1211 static int nfs_post_op_update_inode_locked(struct inode *inode, struct nfs_fattr *fattr)
1212 {
1213 	struct nfs_inode *nfsi = NFS_I(inode);
1214 
1215 	nfsi->cache_validity |= NFS_INO_INVALID_ATTR|NFS_INO_REVAL_PAGECACHE;
1216 	if (S_ISDIR(inode->i_mode)) {
1217 		nfsi->cache_validity |= NFS_INO_INVALID_DATA;
1218 		nfs_fscache_invalidate(inode);
1219 	}
1220 	if ((fattr->valid & NFS_ATTR_FATTR) == 0)
1221 		return 0;
1222 	return nfs_refresh_inode_locked(inode, fattr);
1223 }
1224 
1225 /**
1226  * nfs_post_op_update_inode - try to update the inode attribute cache
1227  * @inode - pointer to inode
1228  * @fattr - updated attributes
1229  *
1230  * After an operation that has changed the inode metadata, mark the
1231  * attribute cache as being invalid, then try to update it.
1232  *
1233  * NB: if the server didn't return any post op attributes, this
1234  * function will force the retrieval of attributes before the next
1235  * NFS request.  Thus it should be used only for operations that
1236  * are expected to change one or more attributes, to avoid
1237  * unnecessary NFS requests and trips through nfs_update_inode().
1238  */
1239 int nfs_post_op_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1240 {
1241 	int status;
1242 
1243 	spin_lock(&inode->i_lock);
1244 	status = nfs_post_op_update_inode_locked(inode, fattr);
1245 	spin_unlock(&inode->i_lock);
1246 	return status;
1247 }
1248 EXPORT_SYMBOL_GPL(nfs_post_op_update_inode);
1249 
1250 /**
1251  * nfs_post_op_update_inode_force_wcc - try to update the inode attribute cache
1252  * @inode - pointer to inode
1253  * @fattr - updated attributes
1254  *
1255  * After an operation that has changed the inode metadata, mark the
1256  * attribute cache as being invalid, then try to update it. Fake up
1257  * weak cache consistency data, if none exist.
1258  *
1259  * This function is mainly designed to be used by the ->write_done() functions.
1260  */
1261 int nfs_post_op_update_inode_force_wcc(struct inode *inode, struct nfs_fattr *fattr)
1262 {
1263 	int status;
1264 
1265 	spin_lock(&inode->i_lock);
1266 	/* Don't do a WCC update if these attributes are already stale */
1267 	if ((fattr->valid & NFS_ATTR_FATTR) == 0 ||
1268 			!nfs_inode_attrs_need_update(inode, fattr)) {
1269 		fattr->valid &= ~(NFS_ATTR_FATTR_PRECHANGE
1270 				| NFS_ATTR_FATTR_PRESIZE
1271 				| NFS_ATTR_FATTR_PREMTIME
1272 				| NFS_ATTR_FATTR_PRECTIME);
1273 		goto out_noforce;
1274 	}
1275 	if ((fattr->valid & NFS_ATTR_FATTR_CHANGE) != 0 &&
1276 			(fattr->valid & NFS_ATTR_FATTR_PRECHANGE) == 0) {
1277 		fattr->pre_change_attr = inode->i_version;
1278 		fattr->valid |= NFS_ATTR_FATTR_PRECHANGE;
1279 	}
1280 	if ((fattr->valid & NFS_ATTR_FATTR_CTIME) != 0 &&
1281 			(fattr->valid & NFS_ATTR_FATTR_PRECTIME) == 0) {
1282 		memcpy(&fattr->pre_ctime, &inode->i_ctime, sizeof(fattr->pre_ctime));
1283 		fattr->valid |= NFS_ATTR_FATTR_PRECTIME;
1284 	}
1285 	if ((fattr->valid & NFS_ATTR_FATTR_MTIME) != 0 &&
1286 			(fattr->valid & NFS_ATTR_FATTR_PREMTIME) == 0) {
1287 		memcpy(&fattr->pre_mtime, &inode->i_mtime, sizeof(fattr->pre_mtime));
1288 		fattr->valid |= NFS_ATTR_FATTR_PREMTIME;
1289 	}
1290 	if ((fattr->valid & NFS_ATTR_FATTR_SIZE) != 0 &&
1291 			(fattr->valid & NFS_ATTR_FATTR_PRESIZE) == 0) {
1292 		fattr->pre_size = i_size_read(inode);
1293 		fattr->valid |= NFS_ATTR_FATTR_PRESIZE;
1294 	}
1295 out_noforce:
1296 	status = nfs_post_op_update_inode_locked(inode, fattr);
1297 	spin_unlock(&inode->i_lock);
1298 	return status;
1299 }
1300 EXPORT_SYMBOL_GPL(nfs_post_op_update_inode_force_wcc);
1301 
1302 /*
1303  * Many nfs protocol calls return the new file attributes after
1304  * an operation.  Here we update the inode to reflect the state
1305  * of the server's inode.
1306  *
1307  * This is a bit tricky because we have to make sure all dirty pages
1308  * have been sent off to the server before calling invalidate_inode_pages.
1309  * To make sure no other process adds more write requests while we try
1310  * our best to flush them, we make them sleep during the attribute refresh.
1311  *
1312  * A very similar scenario holds for the dir cache.
1313  */
1314 static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1315 {
1316 	struct nfs_server *server;
1317 	struct nfs_inode *nfsi = NFS_I(inode);
1318 	loff_t cur_isize, new_isize;
1319 	unsigned long invalid = 0;
1320 	unsigned long now = jiffies;
1321 	unsigned long save_cache_validity;
1322 
1323 	dfprintk(VFS, "NFS: %s(%s/%ld fh_crc=0x%08x ct=%d info=0x%x)\n",
1324 			__func__, inode->i_sb->s_id, inode->i_ino,
1325 			nfs_display_fhandle_hash(NFS_FH(inode)),
1326 			atomic_read(&inode->i_count), fattr->valid);
1327 
1328 	if ((fattr->valid & NFS_ATTR_FATTR_FILEID) && nfsi->fileid != fattr->fileid) {
1329 		printk(KERN_ERR "NFS: server %s error: fileid changed\n"
1330 			"fsid %s: expected fileid 0x%Lx, got 0x%Lx\n",
1331 			NFS_SERVER(inode)->nfs_client->cl_hostname,
1332 			inode->i_sb->s_id, (long long)nfsi->fileid,
1333 			(long long)fattr->fileid);
1334 		goto out_err;
1335 	}
1336 
1337 	/*
1338 	 * Make sure the inode's type hasn't changed.
1339 	 */
1340 	if ((fattr->valid & NFS_ATTR_FATTR_TYPE) && (inode->i_mode & S_IFMT) != (fattr->mode & S_IFMT)) {
1341 		/*
1342 		* Big trouble! The inode has become a different object.
1343 		*/
1344 		printk(KERN_DEBUG "NFS: %s: inode %ld mode changed, %07o to %07o\n",
1345 				__func__, inode->i_ino, inode->i_mode, fattr->mode);
1346 		goto out_err;
1347 	}
1348 
1349 	server = NFS_SERVER(inode);
1350 	/* Update the fsid? */
1351 	if (S_ISDIR(inode->i_mode) && (fattr->valid & NFS_ATTR_FATTR_FSID) &&
1352 			!nfs_fsid_equal(&server->fsid, &fattr->fsid) &&
1353 			!IS_AUTOMOUNT(inode))
1354 		server->fsid = fattr->fsid;
1355 
1356 	/*
1357 	 * Update the read time so we don't revalidate too often.
1358 	 */
1359 	nfsi->read_cache_jiffies = fattr->time_start;
1360 
1361 	save_cache_validity = nfsi->cache_validity;
1362 	nfsi->cache_validity &= ~(NFS_INO_INVALID_ATTR
1363 			| NFS_INO_INVALID_ATIME
1364 			| NFS_INO_REVAL_FORCED
1365 			| NFS_INO_REVAL_PAGECACHE);
1366 
1367 	/* Do atomic weak cache consistency updates */
1368 	invalid |= nfs_wcc_update_inode(inode, fattr);
1369 
1370 	/* More cache consistency checks */
1371 	if (fattr->valid & NFS_ATTR_FATTR_CHANGE) {
1372 		if (inode->i_version != fattr->change_attr) {
1373 			dprintk("NFS: change_attr change on server for file %s/%ld\n",
1374 					inode->i_sb->s_id, inode->i_ino);
1375 			invalid |= NFS_INO_INVALID_ATTR
1376 				| NFS_INO_INVALID_DATA
1377 				| NFS_INO_INVALID_ACCESS
1378 				| NFS_INO_INVALID_ACL
1379 				| NFS_INO_REVAL_PAGECACHE;
1380 			if (S_ISDIR(inode->i_mode))
1381 				nfs_force_lookup_revalidate(inode);
1382 			inode->i_version = fattr->change_attr;
1383 		}
1384 	} else if (server->caps & NFS_CAP_CHANGE_ATTR)
1385 		invalid |= save_cache_validity;
1386 
1387 	if (fattr->valid & NFS_ATTR_FATTR_MTIME) {
1388 		memcpy(&inode->i_mtime, &fattr->mtime, sizeof(inode->i_mtime));
1389 	} else if (server->caps & NFS_CAP_MTIME)
1390 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1391 				| NFS_INO_REVAL_FORCED);
1392 
1393 	if (fattr->valid & NFS_ATTR_FATTR_CTIME) {
1394 		memcpy(&inode->i_ctime, &fattr->ctime, sizeof(inode->i_ctime));
1395 	} else if (server->caps & NFS_CAP_CTIME)
1396 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1397 				| NFS_INO_REVAL_FORCED);
1398 
1399 	/* Check if our cached file size is stale */
1400 	if (fattr->valid & NFS_ATTR_FATTR_SIZE) {
1401 		new_isize = nfs_size_to_loff_t(fattr->size);
1402 		cur_isize = i_size_read(inode);
1403 		if (new_isize != cur_isize) {
1404 			/* Do we perhaps have any outstanding writes, or has
1405 			 * the file grown beyond our last write? */
1406 			if ((nfsi->npages == 0 && !test_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags)) ||
1407 			     new_isize > cur_isize) {
1408 				i_size_write(inode, new_isize);
1409 				invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA;
1410 			}
1411 			dprintk("NFS: isize change on server for file %s/%ld "
1412 					"(%Ld to %Ld)\n",
1413 					inode->i_sb->s_id,
1414 					inode->i_ino,
1415 					(long long)cur_isize,
1416 					(long long)new_isize);
1417 		}
1418 	} else
1419 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1420 				| NFS_INO_REVAL_PAGECACHE
1421 				| NFS_INO_REVAL_FORCED);
1422 
1423 
1424 	if (fattr->valid & NFS_ATTR_FATTR_ATIME)
1425 		memcpy(&inode->i_atime, &fattr->atime, sizeof(inode->i_atime));
1426 	else if (server->caps & NFS_CAP_ATIME)
1427 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATIME
1428 				| NFS_INO_REVAL_FORCED);
1429 
1430 	if (fattr->valid & NFS_ATTR_FATTR_MODE) {
1431 		if ((inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO)) {
1432 			umode_t newmode = inode->i_mode & S_IFMT;
1433 			newmode |= fattr->mode & S_IALLUGO;
1434 			inode->i_mode = newmode;
1435 			invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1436 		}
1437 	} else if (server->caps & NFS_CAP_MODE)
1438 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1439 				| NFS_INO_INVALID_ACCESS
1440 				| NFS_INO_INVALID_ACL
1441 				| NFS_INO_REVAL_FORCED);
1442 
1443 	if (fattr->valid & NFS_ATTR_FATTR_OWNER) {
1444 		if (!uid_eq(inode->i_uid, fattr->uid)) {
1445 			invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1446 			inode->i_uid = fattr->uid;
1447 		}
1448 	} else if (server->caps & NFS_CAP_OWNER)
1449 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1450 				| NFS_INO_INVALID_ACCESS
1451 				| NFS_INO_INVALID_ACL
1452 				| NFS_INO_REVAL_FORCED);
1453 
1454 	if (fattr->valid & NFS_ATTR_FATTR_GROUP) {
1455 		if (!gid_eq(inode->i_gid, fattr->gid)) {
1456 			invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1457 			inode->i_gid = fattr->gid;
1458 		}
1459 	} else if (server->caps & NFS_CAP_OWNER_GROUP)
1460 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1461 				| NFS_INO_INVALID_ACCESS
1462 				| NFS_INO_INVALID_ACL
1463 				| NFS_INO_REVAL_FORCED);
1464 
1465 	if (fattr->valid & NFS_ATTR_FATTR_NLINK) {
1466 		if (inode->i_nlink != fattr->nlink) {
1467 			invalid |= NFS_INO_INVALID_ATTR;
1468 			if (S_ISDIR(inode->i_mode))
1469 				invalid |= NFS_INO_INVALID_DATA;
1470 			set_nlink(inode, fattr->nlink);
1471 		}
1472 	} else if (server->caps & NFS_CAP_NLINK)
1473 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1474 				| NFS_INO_REVAL_FORCED);
1475 
1476 	if (fattr->valid & NFS_ATTR_FATTR_SPACE_USED) {
1477 		/*
1478 		 * report the blocks in 512byte units
1479 		 */
1480 		inode->i_blocks = nfs_calc_block_size(fattr->du.nfs3.used);
1481  	}
1482 	if (fattr->valid & NFS_ATTR_FATTR_BLOCKS_USED)
1483 		inode->i_blocks = fattr->du.nfs2.blocks;
1484 
1485 	/* Update attrtimeo value if we're out of the unstable period */
1486 	if (invalid & NFS_INO_INVALID_ATTR) {
1487 		nfs_inc_stats(inode, NFSIOS_ATTRINVALIDATE);
1488 		nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
1489 		nfsi->attrtimeo_timestamp = now;
1490 		nfsi->attr_gencount = nfs_inc_attr_generation_counter();
1491 	} else {
1492 		if (!time_in_range_open(now, nfsi->attrtimeo_timestamp, nfsi->attrtimeo_timestamp + nfsi->attrtimeo)) {
1493 			if ((nfsi->attrtimeo <<= 1) > NFS_MAXATTRTIMEO(inode))
1494 				nfsi->attrtimeo = NFS_MAXATTRTIMEO(inode);
1495 			nfsi->attrtimeo_timestamp = now;
1496 		}
1497 	}
1498 	invalid &= ~NFS_INO_INVALID_ATTR;
1499 	/* Don't invalidate the data if we were to blame */
1500 	if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)
1501 				|| S_ISLNK(inode->i_mode)))
1502 		invalid &= ~NFS_INO_INVALID_DATA;
1503 	if (!NFS_PROTO(inode)->have_delegation(inode, FMODE_READ) ||
1504 			(save_cache_validity & NFS_INO_REVAL_FORCED))
1505 		nfsi->cache_validity |= invalid;
1506 
1507 	if (invalid & NFS_INO_INVALID_DATA)
1508 		nfs_fscache_invalidate(inode);
1509 
1510 	return 0;
1511  out_err:
1512 	/*
1513 	 * No need to worry about unhashing the dentry, as the
1514 	 * lookup validation will know that the inode is bad.
1515 	 * (But we fall through to invalidate the caches.)
1516 	 */
1517 	nfs_invalidate_inode(inode);
1518 	return -ESTALE;
1519 }
1520 
1521 struct inode *nfs_alloc_inode(struct super_block *sb)
1522 {
1523 	struct nfs_inode *nfsi;
1524 	nfsi = (struct nfs_inode *)kmem_cache_alloc(nfs_inode_cachep, GFP_KERNEL);
1525 	if (!nfsi)
1526 		return NULL;
1527 	nfsi->flags = 0UL;
1528 	nfsi->cache_validity = 0UL;
1529 #ifdef CONFIG_NFS_V3_ACL
1530 	nfsi->acl_access = ERR_PTR(-EAGAIN);
1531 	nfsi->acl_default = ERR_PTR(-EAGAIN);
1532 #endif
1533 #if IS_ENABLED(CONFIG_NFS_V4)
1534 	nfsi->nfs4_acl = NULL;
1535 #endif /* CONFIG_NFS_V4 */
1536 	return &nfsi->vfs_inode;
1537 }
1538 EXPORT_SYMBOL_GPL(nfs_alloc_inode);
1539 
1540 static void nfs_i_callback(struct rcu_head *head)
1541 {
1542 	struct inode *inode = container_of(head, struct inode, i_rcu);
1543 	kmem_cache_free(nfs_inode_cachep, NFS_I(inode));
1544 }
1545 
1546 void nfs_destroy_inode(struct inode *inode)
1547 {
1548 	call_rcu(&inode->i_rcu, nfs_i_callback);
1549 }
1550 EXPORT_SYMBOL_GPL(nfs_destroy_inode);
1551 
1552 static inline void nfs4_init_once(struct nfs_inode *nfsi)
1553 {
1554 #if IS_ENABLED(CONFIG_NFS_V4)
1555 	INIT_LIST_HEAD(&nfsi->open_states);
1556 	nfsi->delegation = NULL;
1557 	nfsi->delegation_state = 0;
1558 	init_rwsem(&nfsi->rwsem);
1559 	nfsi->layout = NULL;
1560 #endif
1561 }
1562 
1563 static void init_once(void *foo)
1564 {
1565 	struct nfs_inode *nfsi = (struct nfs_inode *) foo;
1566 
1567 	inode_init_once(&nfsi->vfs_inode);
1568 	INIT_LIST_HEAD(&nfsi->open_files);
1569 	INIT_LIST_HEAD(&nfsi->access_cache_entry_lru);
1570 	INIT_LIST_HEAD(&nfsi->access_cache_inode_lru);
1571 	INIT_LIST_HEAD(&nfsi->commit_info.list);
1572 	nfsi->npages = 0;
1573 	nfsi->commit_info.ncommit = 0;
1574 	atomic_set(&nfsi->commit_info.rpcs_out, 0);
1575 	atomic_set(&nfsi->silly_count, 1);
1576 	INIT_HLIST_HEAD(&nfsi->silly_list);
1577 	init_waitqueue_head(&nfsi->waitqueue);
1578 	nfs4_init_once(nfsi);
1579 }
1580 
1581 static int __init nfs_init_inodecache(void)
1582 {
1583 	nfs_inode_cachep = kmem_cache_create("nfs_inode_cache",
1584 					     sizeof(struct nfs_inode),
1585 					     0, (SLAB_RECLAIM_ACCOUNT|
1586 						SLAB_MEM_SPREAD),
1587 					     init_once);
1588 	if (nfs_inode_cachep == NULL)
1589 		return -ENOMEM;
1590 
1591 	return 0;
1592 }
1593 
1594 static void nfs_destroy_inodecache(void)
1595 {
1596 	/*
1597 	 * Make sure all delayed rcu free inodes are flushed before we
1598 	 * destroy cache.
1599 	 */
1600 	rcu_barrier();
1601 	kmem_cache_destroy(nfs_inode_cachep);
1602 }
1603 
1604 struct workqueue_struct *nfsiod_workqueue;
1605 EXPORT_SYMBOL_GPL(nfsiod_workqueue);
1606 
1607 /*
1608  * start up the nfsiod workqueue
1609  */
1610 static int nfsiod_start(void)
1611 {
1612 	struct workqueue_struct *wq;
1613 	dprintk("RPC:       creating workqueue nfsiod\n");
1614 	wq = alloc_workqueue("nfsiod", WQ_MEM_RECLAIM, 0);
1615 	if (wq == NULL)
1616 		return -ENOMEM;
1617 	nfsiod_workqueue = wq;
1618 	return 0;
1619 }
1620 
1621 /*
1622  * Destroy the nfsiod workqueue
1623  */
1624 static void nfsiod_stop(void)
1625 {
1626 	struct workqueue_struct *wq;
1627 
1628 	wq = nfsiod_workqueue;
1629 	if (wq == NULL)
1630 		return;
1631 	nfsiod_workqueue = NULL;
1632 	destroy_workqueue(wq);
1633 }
1634 
1635 int nfs_net_id;
1636 EXPORT_SYMBOL_GPL(nfs_net_id);
1637 
1638 static int nfs_net_init(struct net *net)
1639 {
1640 	nfs_clients_init(net);
1641 	return nfs_dns_resolver_cache_init(net);
1642 }
1643 
1644 static void nfs_net_exit(struct net *net)
1645 {
1646 	nfs_dns_resolver_cache_destroy(net);
1647 	nfs_cleanup_cb_ident_idr(net);
1648 }
1649 
1650 static struct pernet_operations nfs_net_ops = {
1651 	.init = nfs_net_init,
1652 	.exit = nfs_net_exit,
1653 	.id   = &nfs_net_id,
1654 	.size = sizeof(struct nfs_net),
1655 };
1656 
1657 /*
1658  * Initialize NFS
1659  */
1660 static int __init init_nfs_fs(void)
1661 {
1662 	int err;
1663 
1664 	err = nfs_dns_resolver_init();
1665 	if (err < 0)
1666 		goto out10;;
1667 
1668 	err = register_pernet_subsys(&nfs_net_ops);
1669 	if (err < 0)
1670 		goto out9;
1671 
1672 	err = nfs_fscache_register();
1673 	if (err < 0)
1674 		goto out8;
1675 
1676 	err = nfsiod_start();
1677 	if (err)
1678 		goto out7;
1679 
1680 	err = nfs_fs_proc_init();
1681 	if (err)
1682 		goto out6;
1683 
1684 	err = nfs_init_nfspagecache();
1685 	if (err)
1686 		goto out5;
1687 
1688 	err = nfs_init_inodecache();
1689 	if (err)
1690 		goto out4;
1691 
1692 	err = nfs_init_readpagecache();
1693 	if (err)
1694 		goto out3;
1695 
1696 	err = nfs_init_writepagecache();
1697 	if (err)
1698 		goto out2;
1699 
1700 	err = nfs_init_directcache();
1701 	if (err)
1702 		goto out1;
1703 
1704 #ifdef CONFIG_PROC_FS
1705 	rpc_proc_register(&init_net, &nfs_rpcstat);
1706 #endif
1707 	if ((err = register_nfs_fs()) != 0)
1708 		goto out0;
1709 
1710 	return 0;
1711 out0:
1712 #ifdef CONFIG_PROC_FS
1713 	rpc_proc_unregister(&init_net, "nfs");
1714 #endif
1715 	nfs_destroy_directcache();
1716 out1:
1717 	nfs_destroy_writepagecache();
1718 out2:
1719 	nfs_destroy_readpagecache();
1720 out3:
1721 	nfs_destroy_inodecache();
1722 out4:
1723 	nfs_destroy_nfspagecache();
1724 out5:
1725 	nfs_fs_proc_exit();
1726 out6:
1727 	nfsiod_stop();
1728 out7:
1729 	nfs_fscache_unregister();
1730 out8:
1731 	unregister_pernet_subsys(&nfs_net_ops);
1732 out9:
1733 	nfs_dns_resolver_destroy();
1734 out10:
1735 	return err;
1736 }
1737 
1738 static void __exit exit_nfs_fs(void)
1739 {
1740 	nfs_destroy_directcache();
1741 	nfs_destroy_writepagecache();
1742 	nfs_destroy_readpagecache();
1743 	nfs_destroy_inodecache();
1744 	nfs_destroy_nfspagecache();
1745 	nfs_fscache_unregister();
1746 	unregister_pernet_subsys(&nfs_net_ops);
1747 	nfs_dns_resolver_destroy();
1748 #ifdef CONFIG_PROC_FS
1749 	rpc_proc_unregister(&init_net, "nfs");
1750 #endif
1751 	unregister_nfs_fs();
1752 	nfs_fs_proc_exit();
1753 	nfsiod_stop();
1754 }
1755 
1756 /* Not quite true; I just maintain it */
1757 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
1758 MODULE_LICENSE("GPL");
1759 module_param(enable_ino64, bool, 0644);
1760 
1761 module_init(init_nfs_fs)
1762 module_exit(exit_nfs_fs)
1763