xref: /openbmc/linux/fs/nfs/inode.c (revision baa7eb025ab14f3cba2e35c0a8648f9c9f01d24f)
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/nfs_idmap.h>
36 #include <linux/vfs.h>
37 #include <linux/inet.h>
38 #include <linux/nfs_xdr.h>
39 #include <linux/slab.h>
40 
41 #include <asm/system.h>
42 #include <asm/uaccess.h>
43 
44 #include "nfs4_fs.h"
45 #include "callback.h"
46 #include "delegation.h"
47 #include "iostat.h"
48 #include "internal.h"
49 #include "fscache.h"
50 #include "dns_resolve.h"
51 #include "pnfs.h"
52 
53 #define NFSDBG_FACILITY		NFSDBG_VFS
54 
55 #define NFS_64_BIT_INODE_NUMBERS_ENABLED	1
56 
57 /* Default is to see 64-bit inode numbers */
58 static int enable_ino64 = NFS_64_BIT_INODE_NUMBERS_ENABLED;
59 
60 static void nfs_invalidate_inode(struct inode *);
61 static int nfs_update_inode(struct inode *, struct nfs_fattr *);
62 
63 static struct kmem_cache * nfs_inode_cachep;
64 
65 static inline unsigned long
66 nfs_fattr_to_ino_t(struct nfs_fattr *fattr)
67 {
68 	return nfs_fileid_to_ino_t(fattr->fileid);
69 }
70 
71 /**
72  * nfs_wait_bit_killable - helper for functions that are sleeping on bit locks
73  * @word: long word containing the bit lock
74  */
75 int nfs_wait_bit_killable(void *word)
76 {
77 	if (fatal_signal_pending(current))
78 		return -ERESTARTSYS;
79 	schedule();
80 	return 0;
81 }
82 
83 /**
84  * nfs_compat_user_ino64 - returns the user-visible inode number
85  * @fileid: 64-bit fileid
86  *
87  * This function returns a 32-bit inode number if the boot parameter
88  * nfs.enable_ino64 is zero.
89  */
90 u64 nfs_compat_user_ino64(u64 fileid)
91 {
92 	int ino;
93 
94 	if (enable_ino64)
95 		return fileid;
96 	ino = fileid;
97 	if (sizeof(ino) < sizeof(fileid))
98 		ino ^= fileid >> (sizeof(fileid)-sizeof(ino)) * 8;
99 	return ino;
100 }
101 
102 static void nfs_clear_inode(struct inode *inode)
103 {
104 	/*
105 	 * The following should never happen...
106 	 */
107 	BUG_ON(nfs_have_writebacks(inode));
108 	BUG_ON(!list_empty(&NFS_I(inode)->open_files));
109 	nfs_zap_acl_cache(inode);
110 	nfs_access_zap_cache(inode);
111 	nfs_fscache_release_inode_cookie(inode);
112 }
113 
114 void nfs_evict_inode(struct inode *inode)
115 {
116 	truncate_inode_pages(&inode->i_data, 0);
117 	end_writeback(inode);
118 	nfs_clear_inode(inode);
119 }
120 
121 /**
122  * nfs_sync_mapping - helper to flush all mmapped dirty data to disk
123  */
124 int nfs_sync_mapping(struct address_space *mapping)
125 {
126 	int ret = 0;
127 
128 	if (mapping->nrpages != 0) {
129 		unmap_mapping_range(mapping, 0, 0, 0);
130 		ret = nfs_wb_all(mapping->host);
131 	}
132 	return ret;
133 }
134 
135 /*
136  * Invalidate the local caches
137  */
138 static void nfs_zap_caches_locked(struct inode *inode)
139 {
140 	struct nfs_inode *nfsi = NFS_I(inode);
141 	int mode = inode->i_mode;
142 
143 	nfs_inc_stats(inode, NFSIOS_ATTRINVALIDATE);
144 
145 	nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
146 	nfsi->attrtimeo_timestamp = jiffies;
147 
148 	memset(NFS_COOKIEVERF(inode), 0, sizeof(NFS_COOKIEVERF(inode)));
149 	if (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))
150 		nfsi->cache_validity |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL|NFS_INO_REVAL_PAGECACHE;
151 	else
152 		nfsi->cache_validity |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL|NFS_INO_REVAL_PAGECACHE;
153 }
154 
155 void nfs_zap_caches(struct inode *inode)
156 {
157 	spin_lock(&inode->i_lock);
158 	nfs_zap_caches_locked(inode);
159 	spin_unlock(&inode->i_lock);
160 }
161 
162 void nfs_zap_mapping(struct inode *inode, struct address_space *mapping)
163 {
164 	if (mapping->nrpages != 0) {
165 		spin_lock(&inode->i_lock);
166 		NFS_I(inode)->cache_validity |= NFS_INO_INVALID_DATA;
167 		spin_unlock(&inode->i_lock);
168 	}
169 }
170 
171 void nfs_zap_acl_cache(struct inode *inode)
172 {
173 	void (*clear_acl_cache)(struct inode *);
174 
175 	clear_acl_cache = NFS_PROTO(inode)->clear_acl_cache;
176 	if (clear_acl_cache != NULL)
177 		clear_acl_cache(inode);
178 	spin_lock(&inode->i_lock);
179 	NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_ACL;
180 	spin_unlock(&inode->i_lock);
181 }
182 
183 void nfs_invalidate_atime(struct inode *inode)
184 {
185 	spin_lock(&inode->i_lock);
186 	NFS_I(inode)->cache_validity |= NFS_INO_INVALID_ATIME;
187 	spin_unlock(&inode->i_lock);
188 }
189 
190 /*
191  * Invalidate, but do not unhash, the inode.
192  * NB: must be called with inode->i_lock held!
193  */
194 static void nfs_invalidate_inode(struct inode *inode)
195 {
196 	set_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
197 	nfs_zap_caches_locked(inode);
198 }
199 
200 struct nfs_find_desc {
201 	struct nfs_fh		*fh;
202 	struct nfs_fattr	*fattr;
203 };
204 
205 /*
206  * In NFSv3 we can have 64bit inode numbers. In order to support
207  * this, and re-exported directories (also seen in NFSv2)
208  * we are forced to allow 2 different inodes to have the same
209  * i_ino.
210  */
211 static int
212 nfs_find_actor(struct inode *inode, void *opaque)
213 {
214 	struct nfs_find_desc	*desc = (struct nfs_find_desc *)opaque;
215 	struct nfs_fh		*fh = desc->fh;
216 	struct nfs_fattr	*fattr = desc->fattr;
217 
218 	if (NFS_FILEID(inode) != fattr->fileid)
219 		return 0;
220 	if (nfs_compare_fh(NFS_FH(inode), fh))
221 		return 0;
222 	if (is_bad_inode(inode) || NFS_STALE(inode))
223 		return 0;
224 	return 1;
225 }
226 
227 static int
228 nfs_init_locked(struct inode *inode, void *opaque)
229 {
230 	struct nfs_find_desc	*desc = (struct nfs_find_desc *)opaque;
231 	struct nfs_fattr	*fattr = desc->fattr;
232 
233 	set_nfs_fileid(inode, fattr->fileid);
234 	nfs_copy_fh(NFS_FH(inode), desc->fh);
235 	return 0;
236 }
237 
238 /*
239  * This is our front-end to iget that looks up inodes by file handle
240  * instead of inode number.
241  */
242 struct inode *
243 nfs_fhget(struct super_block *sb, struct nfs_fh *fh, struct nfs_fattr *fattr)
244 {
245 	struct nfs_find_desc desc = {
246 		.fh	= fh,
247 		.fattr	= fattr
248 	};
249 	struct inode *inode = ERR_PTR(-ENOENT);
250 	unsigned long hash;
251 
252 	if ((fattr->valid & NFS_ATTR_FATTR_FILEID) == 0)
253 		goto out_no_inode;
254 	if ((fattr->valid & NFS_ATTR_FATTR_TYPE) == 0)
255 		goto out_no_inode;
256 
257 	hash = nfs_fattr_to_ino_t(fattr);
258 
259 	inode = iget5_locked(sb, hash, nfs_find_actor, nfs_init_locked, &desc);
260 	if (inode == NULL) {
261 		inode = ERR_PTR(-ENOMEM);
262 		goto out_no_inode;
263 	}
264 
265 	if (inode->i_state & I_NEW) {
266 		struct nfs_inode *nfsi = NFS_I(inode);
267 		unsigned long now = jiffies;
268 
269 		/* We set i_ino for the few things that still rely on it,
270 		 * such as stat(2) */
271 		inode->i_ino = hash;
272 
273 		/* We can't support update_atime(), since the server will reset it */
274 		inode->i_flags |= S_NOATIME|S_NOCMTIME;
275 		inode->i_mode = fattr->mode;
276 		if ((fattr->valid & NFS_ATTR_FATTR_MODE) == 0
277 				&& nfs_server_capable(inode, NFS_CAP_MODE))
278 			nfsi->cache_validity |= NFS_INO_INVALID_ATTR
279 				| NFS_INO_INVALID_ACCESS
280 				| NFS_INO_INVALID_ACL;
281 		/* Why so? Because we want revalidate for devices/FIFOs, and
282 		 * that's precisely what we have in nfs_file_inode_operations.
283 		 */
284 		inode->i_op = NFS_SB(sb)->nfs_client->rpc_ops->file_inode_ops;
285 		if (S_ISREG(inode->i_mode)) {
286 			inode->i_fop = &nfs_file_operations;
287 			inode->i_data.a_ops = &nfs_file_aops;
288 			inode->i_data.backing_dev_info = &NFS_SB(sb)->backing_dev_info;
289 		} else if (S_ISDIR(inode->i_mode)) {
290 			inode->i_op = NFS_SB(sb)->nfs_client->rpc_ops->dir_inode_ops;
291 			inode->i_fop = &nfs_dir_operations;
292 			inode->i_data.a_ops = &nfs_dir_aops;
293 			if (nfs_server_capable(inode, NFS_CAP_READDIRPLUS))
294 				set_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(inode)->flags);
295 			/* Deal with crossing mountpoints */
296 			if ((fattr->valid & NFS_ATTR_FATTR_FSID)
297 					&& !nfs_fsid_equal(&NFS_SB(sb)->fsid, &fattr->fsid)) {
298 				if (fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL)
299 					inode->i_op = &nfs_referral_inode_operations;
300 				else
301 					inode->i_op = &nfs_mountpoint_inode_operations;
302 				inode->i_fop = NULL;
303 				set_bit(NFS_INO_MOUNTPOINT, &nfsi->flags);
304 			}
305 		} else if (S_ISLNK(inode->i_mode))
306 			inode->i_op = &nfs_symlink_inode_operations;
307 		else
308 			init_special_inode(inode, inode->i_mode, fattr->rdev);
309 
310 		memset(&inode->i_atime, 0, sizeof(inode->i_atime));
311 		memset(&inode->i_mtime, 0, sizeof(inode->i_mtime));
312 		memset(&inode->i_ctime, 0, sizeof(inode->i_ctime));
313 		nfsi->change_attr = 0;
314 		inode->i_size = 0;
315 		inode->i_nlink = 0;
316 		inode->i_uid = -2;
317 		inode->i_gid = -2;
318 		inode->i_blocks = 0;
319 		memset(nfsi->cookieverf, 0, sizeof(nfsi->cookieverf));
320 
321 		nfsi->read_cache_jiffies = fattr->time_start;
322 		nfsi->attr_gencount = fattr->gencount;
323 		if (fattr->valid & NFS_ATTR_FATTR_ATIME)
324 			inode->i_atime = fattr->atime;
325 		else if (nfs_server_capable(inode, NFS_CAP_ATIME))
326 			nfsi->cache_validity |= NFS_INO_INVALID_ATTR;
327 		if (fattr->valid & NFS_ATTR_FATTR_MTIME)
328 			inode->i_mtime = fattr->mtime;
329 		else if (nfs_server_capable(inode, NFS_CAP_MTIME))
330 			nfsi->cache_validity |= NFS_INO_INVALID_ATTR
331 				| NFS_INO_INVALID_DATA;
332 		if (fattr->valid & NFS_ATTR_FATTR_CTIME)
333 			inode->i_ctime = fattr->ctime;
334 		else if (nfs_server_capable(inode, NFS_CAP_CTIME))
335 			nfsi->cache_validity |= NFS_INO_INVALID_ATTR
336 				| NFS_INO_INVALID_ACCESS
337 				| NFS_INO_INVALID_ACL;
338 		if (fattr->valid & NFS_ATTR_FATTR_CHANGE)
339 			nfsi->change_attr = fattr->change_attr;
340 		else if (nfs_server_capable(inode, NFS_CAP_CHANGE_ATTR))
341 			nfsi->cache_validity |= NFS_INO_INVALID_ATTR
342 				| NFS_INO_INVALID_DATA;
343 		if (fattr->valid & NFS_ATTR_FATTR_SIZE)
344 			inode->i_size = nfs_size_to_loff_t(fattr->size);
345 		else
346 			nfsi->cache_validity |= NFS_INO_INVALID_ATTR
347 				| NFS_INO_INVALID_DATA
348 				| NFS_INO_REVAL_PAGECACHE;
349 		if (fattr->valid & NFS_ATTR_FATTR_NLINK)
350 			inode->i_nlink = fattr->nlink;
351 		else if (nfs_server_capable(inode, NFS_CAP_NLINK))
352 			nfsi->cache_validity |= NFS_INO_INVALID_ATTR;
353 		if (fattr->valid & NFS_ATTR_FATTR_OWNER)
354 			inode->i_uid = fattr->uid;
355 		else if (nfs_server_capable(inode, NFS_CAP_OWNER))
356 			nfsi->cache_validity |= NFS_INO_INVALID_ATTR
357 				| NFS_INO_INVALID_ACCESS
358 				| NFS_INO_INVALID_ACL;
359 		if (fattr->valid & NFS_ATTR_FATTR_GROUP)
360 			inode->i_gid = fattr->gid;
361 		else if (nfs_server_capable(inode, NFS_CAP_OWNER_GROUP))
362 			nfsi->cache_validity |= NFS_INO_INVALID_ATTR
363 				| NFS_INO_INVALID_ACCESS
364 				| NFS_INO_INVALID_ACL;
365 		if (fattr->valid & NFS_ATTR_FATTR_BLOCKS_USED)
366 			inode->i_blocks = fattr->du.nfs2.blocks;
367 		if (fattr->valid & NFS_ATTR_FATTR_SPACE_USED) {
368 			/*
369 			 * report the blocks in 512byte units
370 			 */
371 			inode->i_blocks = nfs_calc_block_size(fattr->du.nfs3.used);
372 		}
373 		nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
374 		nfsi->attrtimeo_timestamp = now;
375 		nfsi->access_cache = RB_ROOT;
376 
377 		nfs_fscache_init_inode_cookie(inode);
378 
379 		unlock_new_inode(inode);
380 	} else
381 		nfs_refresh_inode(inode, fattr);
382 	dprintk("NFS: nfs_fhget(%s/%Ld ct=%d)\n",
383 		inode->i_sb->s_id,
384 		(long long)NFS_FILEID(inode),
385 		atomic_read(&inode->i_count));
386 
387 out:
388 	return inode;
389 
390 out_no_inode:
391 	dprintk("nfs_fhget: iget failed with error %ld\n", PTR_ERR(inode));
392 	goto out;
393 }
394 
395 #define NFS_VALID_ATTRS (ATTR_MODE|ATTR_UID|ATTR_GID|ATTR_SIZE|ATTR_ATIME|ATTR_ATIME_SET|ATTR_MTIME|ATTR_MTIME_SET|ATTR_FILE)
396 
397 int
398 nfs_setattr(struct dentry *dentry, struct iattr *attr)
399 {
400 	struct inode *inode = dentry->d_inode;
401 	struct nfs_fattr *fattr;
402 	int error = -ENOMEM;
403 
404 	nfs_inc_stats(inode, NFSIOS_VFSSETATTR);
405 
406 	/* skip mode change if it's just for clearing setuid/setgid */
407 	if (attr->ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
408 		attr->ia_valid &= ~ATTR_MODE;
409 
410 	if (attr->ia_valid & ATTR_SIZE) {
411 		if (!S_ISREG(inode->i_mode) || attr->ia_size == i_size_read(inode))
412 			attr->ia_valid &= ~ATTR_SIZE;
413 	}
414 
415 	/* Optimization: if the end result is no change, don't RPC */
416 	attr->ia_valid &= NFS_VALID_ATTRS;
417 	if ((attr->ia_valid & ~ATTR_FILE) == 0)
418 		return 0;
419 
420 	/* Write all dirty data */
421 	if (S_ISREG(inode->i_mode))
422 		nfs_wb_all(inode);
423 
424 	fattr = nfs_alloc_fattr();
425 	if (fattr == NULL)
426 		goto out;
427 	/*
428 	 * Return any delegations if we're going to change ACLs
429 	 */
430 	if ((attr->ia_valid & (ATTR_MODE|ATTR_UID|ATTR_GID)) != 0)
431 		nfs_inode_return_delegation(inode);
432 	error = NFS_PROTO(inode)->setattr(dentry, fattr, attr);
433 	if (error == 0)
434 		nfs_refresh_inode(inode, fattr);
435 	nfs_free_fattr(fattr);
436 out:
437 	return error;
438 }
439 
440 /**
441  * nfs_vmtruncate - unmap mappings "freed" by truncate() syscall
442  * @inode: inode of the file used
443  * @offset: file offset to start truncating
444  *
445  * This is a copy of the common vmtruncate, but with the locking
446  * corrected to take into account the fact that NFS requires
447  * inode->i_size to be updated under the inode->i_lock.
448  */
449 static int nfs_vmtruncate(struct inode * inode, loff_t offset)
450 {
451 	loff_t oldsize;
452 	int err;
453 
454 	err = inode_newsize_ok(inode, offset);
455 	if (err)
456 		goto out;
457 
458 	spin_lock(&inode->i_lock);
459 	oldsize = inode->i_size;
460 	i_size_write(inode, offset);
461 	spin_unlock(&inode->i_lock);
462 
463 	truncate_pagecache(inode, oldsize, offset);
464 out:
465 	return err;
466 }
467 
468 /**
469  * nfs_setattr_update_inode - Update inode metadata after a setattr call.
470  * @inode: pointer to struct inode
471  * @attr: pointer to struct iattr
472  *
473  * Note: we do this in the *proc.c in order to ensure that
474  *       it works for things like exclusive creates too.
475  */
476 void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr)
477 {
478 	if ((attr->ia_valid & (ATTR_MODE|ATTR_UID|ATTR_GID)) != 0) {
479 		spin_lock(&inode->i_lock);
480 		if ((attr->ia_valid & ATTR_MODE) != 0) {
481 			int mode = attr->ia_mode & S_IALLUGO;
482 			mode |= inode->i_mode & ~S_IALLUGO;
483 			inode->i_mode = mode;
484 		}
485 		if ((attr->ia_valid & ATTR_UID) != 0)
486 			inode->i_uid = attr->ia_uid;
487 		if ((attr->ia_valid & ATTR_GID) != 0)
488 			inode->i_gid = attr->ia_gid;
489 		NFS_I(inode)->cache_validity |= NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
490 		spin_unlock(&inode->i_lock);
491 	}
492 	if ((attr->ia_valid & ATTR_SIZE) != 0) {
493 		nfs_inc_stats(inode, NFSIOS_SETATTRTRUNC);
494 		nfs_vmtruncate(inode, attr->ia_size);
495 	}
496 }
497 
498 int nfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
499 {
500 	struct inode *inode = dentry->d_inode;
501 	int need_atime = NFS_I(inode)->cache_validity & NFS_INO_INVALID_ATIME;
502 	int err;
503 
504 	/* Flush out writes to the server in order to update c/mtime.  */
505 	if (S_ISREG(inode->i_mode)) {
506 		err = filemap_write_and_wait(inode->i_mapping);
507 		if (err)
508 			goto out;
509 	}
510 
511 	/*
512 	 * We may force a getattr if the user cares about atime.
513 	 *
514 	 * Note that we only have to check the vfsmount flags here:
515 	 *  - NFS always sets S_NOATIME by so checking it would give a
516 	 *    bogus result
517 	 *  - NFS never sets MS_NOATIME or MS_NODIRATIME so there is
518 	 *    no point in checking those.
519 	 */
520  	if ((mnt->mnt_flags & MNT_NOATIME) ||
521  	    ((mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode)))
522 		need_atime = 0;
523 
524 	if (need_atime)
525 		err = __nfs_revalidate_inode(NFS_SERVER(inode), inode);
526 	else
527 		err = nfs_revalidate_inode(NFS_SERVER(inode), inode);
528 	if (!err) {
529 		generic_fillattr(inode, stat);
530 		stat->ino = nfs_compat_user_ino64(NFS_FILEID(inode));
531 	}
532 out:
533 	return err;
534 }
535 
536 static void nfs_init_lock_context(struct nfs_lock_context *l_ctx)
537 {
538 	atomic_set(&l_ctx->count, 1);
539 	l_ctx->lockowner = current->files;
540 	l_ctx->pid = current->tgid;
541 	INIT_LIST_HEAD(&l_ctx->list);
542 }
543 
544 static struct nfs_lock_context *__nfs_find_lock_context(struct nfs_open_context *ctx)
545 {
546 	struct nfs_lock_context *pos;
547 
548 	list_for_each_entry(pos, &ctx->lock_context.list, list) {
549 		if (pos->lockowner != current->files)
550 			continue;
551 		if (pos->pid != current->tgid)
552 			continue;
553 		atomic_inc(&pos->count);
554 		return pos;
555 	}
556 	return NULL;
557 }
558 
559 struct nfs_lock_context *nfs_get_lock_context(struct nfs_open_context *ctx)
560 {
561 	struct nfs_lock_context *res, *new = NULL;
562 	struct inode *inode = ctx->path.dentry->d_inode;
563 
564 	spin_lock(&inode->i_lock);
565 	res = __nfs_find_lock_context(ctx);
566 	if (res == NULL) {
567 		spin_unlock(&inode->i_lock);
568 		new = kmalloc(sizeof(*new), GFP_KERNEL);
569 		if (new == NULL)
570 			return NULL;
571 		nfs_init_lock_context(new);
572 		spin_lock(&inode->i_lock);
573 		res = __nfs_find_lock_context(ctx);
574 		if (res == NULL) {
575 			list_add_tail(&new->list, &ctx->lock_context.list);
576 			new->open_context = ctx;
577 			res = new;
578 			new = NULL;
579 		}
580 	}
581 	spin_unlock(&inode->i_lock);
582 	kfree(new);
583 	return res;
584 }
585 
586 void nfs_put_lock_context(struct nfs_lock_context *l_ctx)
587 {
588 	struct nfs_open_context *ctx = l_ctx->open_context;
589 	struct inode *inode = ctx->path.dentry->d_inode;
590 
591 	if (!atomic_dec_and_lock(&l_ctx->count, &inode->i_lock))
592 		return;
593 	list_del(&l_ctx->list);
594 	spin_unlock(&inode->i_lock);
595 	kfree(l_ctx);
596 }
597 
598 /**
599  * nfs_close_context - Common close_context() routine NFSv2/v3
600  * @ctx: pointer to context
601  * @is_sync: is this a synchronous close
602  *
603  * always ensure that the attributes are up to date if we're mounted
604  * with close-to-open semantics
605  */
606 void nfs_close_context(struct nfs_open_context *ctx, int is_sync)
607 {
608 	struct inode *inode;
609 	struct nfs_server *server;
610 
611 	if (!(ctx->mode & FMODE_WRITE))
612 		return;
613 	if (!is_sync)
614 		return;
615 	inode = ctx->path.dentry->d_inode;
616 	if (!list_empty(&NFS_I(inode)->open_files))
617 		return;
618 	server = NFS_SERVER(inode);
619 	if (server->flags & NFS_MOUNT_NOCTO)
620 		return;
621 	nfs_revalidate_inode(server, inode);
622 }
623 
624 struct nfs_open_context *alloc_nfs_open_context(struct path *path, struct rpc_cred *cred, fmode_t f_mode)
625 {
626 	struct nfs_open_context *ctx;
627 
628 	ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
629 	if (ctx != NULL) {
630 		ctx->path = *path;
631 		path_get(&ctx->path);
632 		ctx->cred = get_rpccred(cred);
633 		ctx->state = NULL;
634 		ctx->mode = f_mode;
635 		ctx->flags = 0;
636 		ctx->error = 0;
637 		ctx->dir_cookie = 0;
638 		nfs_init_lock_context(&ctx->lock_context);
639 		ctx->lock_context.open_context = ctx;
640 		INIT_LIST_HEAD(&ctx->list);
641 	}
642 	return ctx;
643 }
644 
645 struct nfs_open_context *get_nfs_open_context(struct nfs_open_context *ctx)
646 {
647 	if (ctx != NULL)
648 		atomic_inc(&ctx->lock_context.count);
649 	return ctx;
650 }
651 
652 static void __put_nfs_open_context(struct nfs_open_context *ctx, int is_sync)
653 {
654 	struct inode *inode = ctx->path.dentry->d_inode;
655 
656 	if (!list_empty(&ctx->list)) {
657 		if (!atomic_dec_and_lock(&ctx->lock_context.count, &inode->i_lock))
658 			return;
659 		list_del(&ctx->list);
660 		spin_unlock(&inode->i_lock);
661 	} else if (!atomic_dec_and_test(&ctx->lock_context.count))
662 		return;
663 	if (inode != NULL)
664 		NFS_PROTO(inode)->close_context(ctx, is_sync);
665 	if (ctx->cred != NULL)
666 		put_rpccred(ctx->cred);
667 	path_put(&ctx->path);
668 	kfree(ctx);
669 }
670 
671 void put_nfs_open_context(struct nfs_open_context *ctx)
672 {
673 	__put_nfs_open_context(ctx, 0);
674 }
675 
676 /*
677  * Ensure that mmap has a recent RPC credential for use when writing out
678  * shared pages
679  */
680 void nfs_file_set_open_context(struct file *filp, struct nfs_open_context *ctx)
681 {
682 	struct inode *inode = filp->f_path.dentry->d_inode;
683 	struct nfs_inode *nfsi = NFS_I(inode);
684 
685 	filp->private_data = get_nfs_open_context(ctx);
686 	spin_lock(&inode->i_lock);
687 	list_add(&ctx->list, &nfsi->open_files);
688 	spin_unlock(&inode->i_lock);
689 }
690 
691 /*
692  * Given an inode, search for an open context with the desired characteristics
693  */
694 struct nfs_open_context *nfs_find_open_context(struct inode *inode, struct rpc_cred *cred, fmode_t mode)
695 {
696 	struct nfs_inode *nfsi = NFS_I(inode);
697 	struct nfs_open_context *pos, *ctx = NULL;
698 
699 	spin_lock(&inode->i_lock);
700 	list_for_each_entry(pos, &nfsi->open_files, list) {
701 		if (cred != NULL && pos->cred != cred)
702 			continue;
703 		if ((pos->mode & (FMODE_READ|FMODE_WRITE)) != mode)
704 			continue;
705 		ctx = get_nfs_open_context(pos);
706 		break;
707 	}
708 	spin_unlock(&inode->i_lock);
709 	return ctx;
710 }
711 
712 static void nfs_file_clear_open_context(struct file *filp)
713 {
714 	struct inode *inode = filp->f_path.dentry->d_inode;
715 	struct nfs_open_context *ctx = nfs_file_open_context(filp);
716 
717 	if (ctx) {
718 		filp->private_data = NULL;
719 		spin_lock(&inode->i_lock);
720 		list_move_tail(&ctx->list, &NFS_I(inode)->open_files);
721 		spin_unlock(&inode->i_lock);
722 		__put_nfs_open_context(ctx, filp->f_flags & O_DIRECT ? 0 : 1);
723 	}
724 }
725 
726 /*
727  * These allocate and release file read/write context information.
728  */
729 int nfs_open(struct inode *inode, struct file *filp)
730 {
731 	struct nfs_open_context *ctx;
732 	struct rpc_cred *cred;
733 
734 	cred = rpc_lookup_cred();
735 	if (IS_ERR(cred))
736 		return PTR_ERR(cred);
737 	ctx = alloc_nfs_open_context(&filp->f_path, cred, filp->f_mode);
738 	put_rpccred(cred);
739 	if (ctx == NULL)
740 		return -ENOMEM;
741 	nfs_file_set_open_context(filp, ctx);
742 	put_nfs_open_context(ctx);
743 	nfs_fscache_set_inode_cookie(inode, filp);
744 	return 0;
745 }
746 
747 int nfs_release(struct inode *inode, struct file *filp)
748 {
749 	nfs_file_clear_open_context(filp);
750 	return 0;
751 }
752 
753 /*
754  * This function is called whenever some part of NFS notices that
755  * the cached attributes have to be refreshed.
756  */
757 int
758 __nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
759 {
760 	int		 status = -ESTALE;
761 	struct nfs_fattr *fattr = NULL;
762 	struct nfs_inode *nfsi = NFS_I(inode);
763 
764 	dfprintk(PAGECACHE, "NFS: revalidating (%s/%Ld)\n",
765 		inode->i_sb->s_id, (long long)NFS_FILEID(inode));
766 
767 	if (is_bad_inode(inode))
768 		goto out;
769 	if (NFS_STALE(inode))
770 		goto out;
771 
772 	status = -ENOMEM;
773 	fattr = nfs_alloc_fattr();
774 	if (fattr == NULL)
775 		goto out;
776 
777 	nfs_inc_stats(inode, NFSIOS_INODEREVALIDATE);
778 	status = NFS_PROTO(inode)->getattr(server, NFS_FH(inode), fattr);
779 	if (status != 0) {
780 		dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Ld) getattr failed, error=%d\n",
781 			 inode->i_sb->s_id,
782 			 (long long)NFS_FILEID(inode), status);
783 		if (status == -ESTALE) {
784 			nfs_zap_caches(inode);
785 			if (!S_ISDIR(inode->i_mode))
786 				set_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
787 		}
788 		goto out;
789 	}
790 
791 	status = nfs_refresh_inode(inode, fattr);
792 	if (status) {
793 		dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Ld) refresh failed, error=%d\n",
794 			 inode->i_sb->s_id,
795 			 (long long)NFS_FILEID(inode), status);
796 		goto out;
797 	}
798 
799 	if (nfsi->cache_validity & NFS_INO_INVALID_ACL)
800 		nfs_zap_acl_cache(inode);
801 
802 	dfprintk(PAGECACHE, "NFS: (%s/%Ld) revalidation complete\n",
803 		inode->i_sb->s_id,
804 		(long long)NFS_FILEID(inode));
805 
806  out:
807 	nfs_free_fattr(fattr);
808 	return status;
809 }
810 
811 int nfs_attribute_timeout(struct inode *inode)
812 {
813 	struct nfs_inode *nfsi = NFS_I(inode);
814 
815 	return !time_in_range_open(jiffies, nfsi->read_cache_jiffies, nfsi->read_cache_jiffies + nfsi->attrtimeo);
816 }
817 
818 static int nfs_attribute_cache_expired(struct inode *inode)
819 {
820 	if (nfs_have_delegated_attributes(inode))
821 		return 0;
822 	return nfs_attribute_timeout(inode);
823 }
824 
825 /**
826  * nfs_revalidate_inode - Revalidate the inode attributes
827  * @server - pointer to nfs_server struct
828  * @inode - pointer to inode struct
829  *
830  * Updates inode attribute information by retrieving the data from the server.
831  */
832 int nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
833 {
834 	if (!(NFS_I(inode)->cache_validity & NFS_INO_INVALID_ATTR)
835 			&& !nfs_attribute_cache_expired(inode))
836 		return NFS_STALE(inode) ? -ESTALE : 0;
837 	return __nfs_revalidate_inode(server, inode);
838 }
839 
840 static int nfs_invalidate_mapping(struct inode *inode, struct address_space *mapping)
841 {
842 	struct nfs_inode *nfsi = NFS_I(inode);
843 
844 	if (mapping->nrpages != 0) {
845 		int ret = invalidate_inode_pages2(mapping);
846 		if (ret < 0)
847 			return ret;
848 	}
849 	spin_lock(&inode->i_lock);
850 	nfsi->cache_validity &= ~NFS_INO_INVALID_DATA;
851 	if (S_ISDIR(inode->i_mode))
852 		memset(nfsi->cookieverf, 0, sizeof(nfsi->cookieverf));
853 	spin_unlock(&inode->i_lock);
854 	nfs_inc_stats(inode, NFSIOS_DATAINVALIDATE);
855 	nfs_fscache_reset_inode_cookie(inode);
856 	dfprintk(PAGECACHE, "NFS: (%s/%Ld) data cache invalidated\n",
857 			inode->i_sb->s_id, (long long)NFS_FILEID(inode));
858 	return 0;
859 }
860 
861 /**
862  * nfs_revalidate_mapping - Revalidate the pagecache
863  * @inode - pointer to host inode
864  * @mapping - pointer to mapping
865  */
866 int nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping)
867 {
868 	struct nfs_inode *nfsi = NFS_I(inode);
869 	int ret = 0;
870 
871 	if ((nfsi->cache_validity & NFS_INO_REVAL_PAGECACHE)
872 			|| nfs_attribute_cache_expired(inode)
873 			|| NFS_STALE(inode)) {
874 		ret = __nfs_revalidate_inode(NFS_SERVER(inode), inode);
875 		if (ret < 0)
876 			goto out;
877 	}
878 	if (nfsi->cache_validity & NFS_INO_INVALID_DATA)
879 		ret = nfs_invalidate_mapping(inode, mapping);
880 out:
881 	return ret;
882 }
883 
884 static void nfs_wcc_update_inode(struct inode *inode, struct nfs_fattr *fattr)
885 {
886 	struct nfs_inode *nfsi = NFS_I(inode);
887 
888 	if ((fattr->valid & NFS_ATTR_FATTR_PRECHANGE)
889 			&& (fattr->valid & NFS_ATTR_FATTR_CHANGE)
890 			&& nfsi->change_attr == fattr->pre_change_attr) {
891 		nfsi->change_attr = fattr->change_attr;
892 		if (S_ISDIR(inode->i_mode))
893 			nfsi->cache_validity |= NFS_INO_INVALID_DATA;
894 	}
895 	/* If we have atomic WCC data, we may update some attributes */
896 	if ((fattr->valid & NFS_ATTR_FATTR_PRECTIME)
897 			&& (fattr->valid & NFS_ATTR_FATTR_CTIME)
898 			&& timespec_equal(&inode->i_ctime, &fattr->pre_ctime))
899 			memcpy(&inode->i_ctime, &fattr->ctime, sizeof(inode->i_ctime));
900 
901 	if ((fattr->valid & NFS_ATTR_FATTR_PREMTIME)
902 			&& (fattr->valid & NFS_ATTR_FATTR_MTIME)
903 			&& timespec_equal(&inode->i_mtime, &fattr->pre_mtime)) {
904 			memcpy(&inode->i_mtime, &fattr->mtime, sizeof(inode->i_mtime));
905 			if (S_ISDIR(inode->i_mode))
906 				nfsi->cache_validity |= NFS_INO_INVALID_DATA;
907 	}
908 	if ((fattr->valid & NFS_ATTR_FATTR_PRESIZE)
909 			&& (fattr->valid & NFS_ATTR_FATTR_SIZE)
910 			&& i_size_read(inode) == nfs_size_to_loff_t(fattr->pre_size)
911 			&& nfsi->npages == 0)
912 			i_size_write(inode, nfs_size_to_loff_t(fattr->size));
913 }
914 
915 /**
916  * nfs_check_inode_attributes - verify consistency of the inode attribute cache
917  * @inode - pointer to inode
918  * @fattr - updated attributes
919  *
920  * Verifies the attribute cache. If we have just changed the attributes,
921  * so that fattr carries weak cache consistency data, then it may
922  * also update the ctime/mtime/change_attribute.
923  */
924 static int nfs_check_inode_attributes(struct inode *inode, struct nfs_fattr *fattr)
925 {
926 	struct nfs_inode *nfsi = NFS_I(inode);
927 	loff_t cur_size, new_isize;
928 	unsigned long invalid = 0;
929 
930 
931 	/* Has the inode gone and changed behind our back? */
932 	if ((fattr->valid & NFS_ATTR_FATTR_FILEID) && nfsi->fileid != fattr->fileid)
933 		return -EIO;
934 	if ((fattr->valid & NFS_ATTR_FATTR_TYPE) && (inode->i_mode & S_IFMT) != (fattr->mode & S_IFMT))
935 		return -EIO;
936 
937 	if ((fattr->valid & NFS_ATTR_FATTR_CHANGE) != 0 &&
938 			nfsi->change_attr != fattr->change_attr)
939 		invalid |= NFS_INO_INVALID_ATTR|NFS_INO_REVAL_PAGECACHE;
940 
941 	/* Verify a few of the more important attributes */
942 	if ((fattr->valid & NFS_ATTR_FATTR_MTIME) && !timespec_equal(&inode->i_mtime, &fattr->mtime))
943 		invalid |= NFS_INO_INVALID_ATTR|NFS_INO_REVAL_PAGECACHE;
944 
945 	if (fattr->valid & NFS_ATTR_FATTR_SIZE) {
946 		cur_size = i_size_read(inode);
947 		new_isize = nfs_size_to_loff_t(fattr->size);
948 		if (cur_size != new_isize && nfsi->npages == 0)
949 			invalid |= NFS_INO_INVALID_ATTR|NFS_INO_REVAL_PAGECACHE;
950 	}
951 
952 	/* Have any file permissions changed? */
953 	if ((fattr->valid & NFS_ATTR_FATTR_MODE) && (inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO))
954 		invalid |= NFS_INO_INVALID_ATTR | NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL;
955 	if ((fattr->valid & NFS_ATTR_FATTR_OWNER) && inode->i_uid != fattr->uid)
956 		invalid |= NFS_INO_INVALID_ATTR | NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL;
957 	if ((fattr->valid & NFS_ATTR_FATTR_GROUP) && inode->i_gid != fattr->gid)
958 		invalid |= NFS_INO_INVALID_ATTR | NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL;
959 
960 	/* Has the link count changed? */
961 	if ((fattr->valid & NFS_ATTR_FATTR_NLINK) && inode->i_nlink != fattr->nlink)
962 		invalid |= NFS_INO_INVALID_ATTR;
963 
964 	if ((fattr->valid & NFS_ATTR_FATTR_ATIME) && !timespec_equal(&inode->i_atime, &fattr->atime))
965 		invalid |= NFS_INO_INVALID_ATIME;
966 
967 	if (invalid != 0)
968 		nfsi->cache_validity |= invalid;
969 
970 	nfsi->read_cache_jiffies = fattr->time_start;
971 	return 0;
972 }
973 
974 static int nfs_ctime_need_update(const struct inode *inode, const struct nfs_fattr *fattr)
975 {
976 	if (!(fattr->valid & NFS_ATTR_FATTR_CTIME))
977 		return 0;
978 	return timespec_compare(&fattr->ctime, &inode->i_ctime) > 0;
979 }
980 
981 static int nfs_size_need_update(const struct inode *inode, const struct nfs_fattr *fattr)
982 {
983 	if (!(fattr->valid & NFS_ATTR_FATTR_SIZE))
984 		return 0;
985 	return nfs_size_to_loff_t(fattr->size) > i_size_read(inode);
986 }
987 
988 static atomic_long_t nfs_attr_generation_counter;
989 
990 static unsigned long nfs_read_attr_generation_counter(void)
991 {
992 	return atomic_long_read(&nfs_attr_generation_counter);
993 }
994 
995 unsigned long nfs_inc_attr_generation_counter(void)
996 {
997 	return atomic_long_inc_return(&nfs_attr_generation_counter);
998 }
999 
1000 void nfs_fattr_init(struct nfs_fattr *fattr)
1001 {
1002 	fattr->valid = 0;
1003 	fattr->time_start = jiffies;
1004 	fattr->gencount = nfs_inc_attr_generation_counter();
1005 }
1006 
1007 struct nfs_fattr *nfs_alloc_fattr(void)
1008 {
1009 	struct nfs_fattr *fattr;
1010 
1011 	fattr = kmalloc(sizeof(*fattr), GFP_NOFS);
1012 	if (fattr != NULL)
1013 		nfs_fattr_init(fattr);
1014 	return fattr;
1015 }
1016 
1017 struct nfs_fh *nfs_alloc_fhandle(void)
1018 {
1019 	struct nfs_fh *fh;
1020 
1021 	fh = kmalloc(sizeof(struct nfs_fh), GFP_NOFS);
1022 	if (fh != NULL)
1023 		fh->size = 0;
1024 	return fh;
1025 }
1026 
1027 /**
1028  * nfs_inode_attrs_need_update - check if the inode attributes need updating
1029  * @inode - pointer to inode
1030  * @fattr - attributes
1031  *
1032  * Attempt to divine whether or not an RPC call reply carrying stale
1033  * attributes got scheduled after another call carrying updated ones.
1034  *
1035  * To do so, the function first assumes that a more recent ctime means
1036  * that the attributes in fattr are newer, however it also attempt to
1037  * catch the case where ctime either didn't change, or went backwards
1038  * (if someone reset the clock on the server) by looking at whether
1039  * or not this RPC call was started after the inode was last updated.
1040  * Note also the check for wraparound of 'attr_gencount'
1041  *
1042  * The function returns 'true' if it thinks the attributes in 'fattr' are
1043  * more recent than the ones cached in the inode.
1044  *
1045  */
1046 static int nfs_inode_attrs_need_update(const struct inode *inode, const struct nfs_fattr *fattr)
1047 {
1048 	const struct nfs_inode *nfsi = NFS_I(inode);
1049 
1050 	return ((long)fattr->gencount - (long)nfsi->attr_gencount) > 0 ||
1051 		nfs_ctime_need_update(inode, fattr) ||
1052 		nfs_size_need_update(inode, fattr) ||
1053 		((long)nfsi->attr_gencount - (long)nfs_read_attr_generation_counter() > 0);
1054 }
1055 
1056 static int nfs_refresh_inode_locked(struct inode *inode, struct nfs_fattr *fattr)
1057 {
1058 	if (nfs_inode_attrs_need_update(inode, fattr))
1059 		return nfs_update_inode(inode, fattr);
1060 	return nfs_check_inode_attributes(inode, fattr);
1061 }
1062 
1063 /**
1064  * nfs_refresh_inode - try to update the inode attribute cache
1065  * @inode - pointer to inode
1066  * @fattr - updated attributes
1067  *
1068  * Check that an RPC call that returned attributes has not overlapped with
1069  * other recent updates of the inode metadata, then decide whether it is
1070  * safe to do a full update of the inode attributes, or whether just to
1071  * call nfs_check_inode_attributes.
1072  */
1073 int nfs_refresh_inode(struct inode *inode, struct nfs_fattr *fattr)
1074 {
1075 	int status;
1076 
1077 	if ((fattr->valid & NFS_ATTR_FATTR) == 0)
1078 		return 0;
1079 	spin_lock(&inode->i_lock);
1080 	status = nfs_refresh_inode_locked(inode, fattr);
1081 	spin_unlock(&inode->i_lock);
1082 
1083 	return status;
1084 }
1085 
1086 static int nfs_post_op_update_inode_locked(struct inode *inode, struct nfs_fattr *fattr)
1087 {
1088 	struct nfs_inode *nfsi = NFS_I(inode);
1089 
1090 	nfsi->cache_validity |= NFS_INO_INVALID_ATTR|NFS_INO_REVAL_PAGECACHE;
1091 	if (S_ISDIR(inode->i_mode))
1092 		nfsi->cache_validity |= NFS_INO_INVALID_DATA;
1093 	if ((fattr->valid & NFS_ATTR_FATTR) == 0)
1094 		return 0;
1095 	return nfs_refresh_inode_locked(inode, fattr);
1096 }
1097 
1098 /**
1099  * nfs_post_op_update_inode - try to update the inode attribute cache
1100  * @inode - pointer to inode
1101  * @fattr - updated attributes
1102  *
1103  * After an operation that has changed the inode metadata, mark the
1104  * attribute cache as being invalid, then try to update it.
1105  *
1106  * NB: if the server didn't return any post op attributes, this
1107  * function will force the retrieval of attributes before the next
1108  * NFS request.  Thus it should be used only for operations that
1109  * are expected to change one or more attributes, to avoid
1110  * unnecessary NFS requests and trips through nfs_update_inode().
1111  */
1112 int nfs_post_op_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1113 {
1114 	int status;
1115 
1116 	spin_lock(&inode->i_lock);
1117 	status = nfs_post_op_update_inode_locked(inode, fattr);
1118 	spin_unlock(&inode->i_lock);
1119 	return status;
1120 }
1121 
1122 /**
1123  * nfs_post_op_update_inode_force_wcc - try to update the inode attribute cache
1124  * @inode - pointer to inode
1125  * @fattr - updated attributes
1126  *
1127  * After an operation that has changed the inode metadata, mark the
1128  * attribute cache as being invalid, then try to update it. Fake up
1129  * weak cache consistency data, if none exist.
1130  *
1131  * This function is mainly designed to be used by the ->write_done() functions.
1132  */
1133 int nfs_post_op_update_inode_force_wcc(struct inode *inode, struct nfs_fattr *fattr)
1134 {
1135 	int status;
1136 
1137 	spin_lock(&inode->i_lock);
1138 	/* Don't do a WCC update if these attributes are already stale */
1139 	if ((fattr->valid & NFS_ATTR_FATTR) == 0 ||
1140 			!nfs_inode_attrs_need_update(inode, fattr)) {
1141 		fattr->valid &= ~(NFS_ATTR_FATTR_PRECHANGE
1142 				| NFS_ATTR_FATTR_PRESIZE
1143 				| NFS_ATTR_FATTR_PREMTIME
1144 				| NFS_ATTR_FATTR_PRECTIME);
1145 		goto out_noforce;
1146 	}
1147 	if ((fattr->valid & NFS_ATTR_FATTR_CHANGE) != 0 &&
1148 			(fattr->valid & NFS_ATTR_FATTR_PRECHANGE) == 0) {
1149 		fattr->pre_change_attr = NFS_I(inode)->change_attr;
1150 		fattr->valid |= NFS_ATTR_FATTR_PRECHANGE;
1151 	}
1152 	if ((fattr->valid & NFS_ATTR_FATTR_CTIME) != 0 &&
1153 			(fattr->valid & NFS_ATTR_FATTR_PRECTIME) == 0) {
1154 		memcpy(&fattr->pre_ctime, &inode->i_ctime, sizeof(fattr->pre_ctime));
1155 		fattr->valid |= NFS_ATTR_FATTR_PRECTIME;
1156 	}
1157 	if ((fattr->valid & NFS_ATTR_FATTR_MTIME) != 0 &&
1158 			(fattr->valid & NFS_ATTR_FATTR_PREMTIME) == 0) {
1159 		memcpy(&fattr->pre_mtime, &inode->i_mtime, sizeof(fattr->pre_mtime));
1160 		fattr->valid |= NFS_ATTR_FATTR_PREMTIME;
1161 	}
1162 	if ((fattr->valid & NFS_ATTR_FATTR_SIZE) != 0 &&
1163 			(fattr->valid & NFS_ATTR_FATTR_PRESIZE) == 0) {
1164 		fattr->pre_size = i_size_read(inode);
1165 		fattr->valid |= NFS_ATTR_FATTR_PRESIZE;
1166 	}
1167 out_noforce:
1168 	status = nfs_post_op_update_inode_locked(inode, fattr);
1169 	spin_unlock(&inode->i_lock);
1170 	return status;
1171 }
1172 
1173 /*
1174  * Many nfs protocol calls return the new file attributes after
1175  * an operation.  Here we update the inode to reflect the state
1176  * of the server's inode.
1177  *
1178  * This is a bit tricky because we have to make sure all dirty pages
1179  * have been sent off to the server before calling invalidate_inode_pages.
1180  * To make sure no other process adds more write requests while we try
1181  * our best to flush them, we make them sleep during the attribute refresh.
1182  *
1183  * A very similar scenario holds for the dir cache.
1184  */
1185 static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1186 {
1187 	struct nfs_server *server;
1188 	struct nfs_inode *nfsi = NFS_I(inode);
1189 	loff_t cur_isize, new_isize;
1190 	unsigned long invalid = 0;
1191 	unsigned long now = jiffies;
1192 	unsigned long save_cache_validity;
1193 
1194 	dfprintk(VFS, "NFS: %s(%s/%ld ct=%d info=0x%x)\n",
1195 			__func__, inode->i_sb->s_id, inode->i_ino,
1196 			atomic_read(&inode->i_count), fattr->valid);
1197 
1198 	if ((fattr->valid & NFS_ATTR_FATTR_FILEID) && nfsi->fileid != fattr->fileid)
1199 		goto out_fileid;
1200 
1201 	/*
1202 	 * Make sure the inode's type hasn't changed.
1203 	 */
1204 	if ((fattr->valid & NFS_ATTR_FATTR_TYPE) && (inode->i_mode & S_IFMT) != (fattr->mode & S_IFMT))
1205 		goto out_changed;
1206 
1207 	server = NFS_SERVER(inode);
1208 	/* Update the fsid? */
1209 	if (S_ISDIR(inode->i_mode) && (fattr->valid & NFS_ATTR_FATTR_FSID) &&
1210 			!nfs_fsid_equal(&server->fsid, &fattr->fsid) &&
1211 			!test_bit(NFS_INO_MOUNTPOINT, &nfsi->flags))
1212 		server->fsid = fattr->fsid;
1213 
1214 	/*
1215 	 * Update the read time so we don't revalidate too often.
1216 	 */
1217 	nfsi->read_cache_jiffies = fattr->time_start;
1218 
1219 	save_cache_validity = nfsi->cache_validity;
1220 	nfsi->cache_validity &= ~(NFS_INO_INVALID_ATTR
1221 			| NFS_INO_INVALID_ATIME
1222 			| NFS_INO_REVAL_FORCED
1223 			| NFS_INO_REVAL_PAGECACHE);
1224 
1225 	/* Do atomic weak cache consistency updates */
1226 	nfs_wcc_update_inode(inode, fattr);
1227 
1228 	/* More cache consistency checks */
1229 	if (fattr->valid & NFS_ATTR_FATTR_CHANGE) {
1230 		if (nfsi->change_attr != fattr->change_attr) {
1231 			dprintk("NFS: change_attr change on server for file %s/%ld\n",
1232 					inode->i_sb->s_id, inode->i_ino);
1233 			invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1234 			if (S_ISDIR(inode->i_mode))
1235 				nfs_force_lookup_revalidate(inode);
1236 			nfsi->change_attr = fattr->change_attr;
1237 		}
1238 	} else if (server->caps & NFS_CAP_CHANGE_ATTR)
1239 		invalid |= save_cache_validity;
1240 
1241 	if (fattr->valid & NFS_ATTR_FATTR_MTIME) {
1242 		/* NFSv2/v3: Check if the mtime agrees */
1243 		if (!timespec_equal(&inode->i_mtime, &fattr->mtime)) {
1244 			dprintk("NFS: mtime change on server for file %s/%ld\n",
1245 					inode->i_sb->s_id, inode->i_ino);
1246 			invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA;
1247 			if (S_ISDIR(inode->i_mode))
1248 				nfs_force_lookup_revalidate(inode);
1249 			memcpy(&inode->i_mtime, &fattr->mtime, sizeof(inode->i_mtime));
1250 		}
1251 	} else if (server->caps & NFS_CAP_MTIME)
1252 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1253 				| NFS_INO_INVALID_DATA
1254 				| NFS_INO_REVAL_PAGECACHE
1255 				| NFS_INO_REVAL_FORCED);
1256 
1257 	if (fattr->valid & NFS_ATTR_FATTR_CTIME) {
1258 		/* If ctime has changed we should definitely clear access+acl caches */
1259 		if (!timespec_equal(&inode->i_ctime, &fattr->ctime)) {
1260 			invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1261 			/* and probably clear data for a directory too as utimes can cause
1262 			 * havoc with our cache.
1263 			 */
1264 			if (S_ISDIR(inode->i_mode)) {
1265 				invalid |= NFS_INO_INVALID_DATA;
1266 				nfs_force_lookup_revalidate(inode);
1267 			}
1268 			memcpy(&inode->i_ctime, &fattr->ctime, sizeof(inode->i_ctime));
1269 		}
1270 	} else if (server->caps & NFS_CAP_CTIME)
1271 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1272 				| NFS_INO_INVALID_ACCESS
1273 				| NFS_INO_INVALID_ACL
1274 				| NFS_INO_REVAL_FORCED);
1275 
1276 	/* Check if our cached file size is stale */
1277 	if (fattr->valid & NFS_ATTR_FATTR_SIZE) {
1278 		new_isize = nfs_size_to_loff_t(fattr->size);
1279 		cur_isize = i_size_read(inode);
1280 		if (new_isize != cur_isize) {
1281 			/* Do we perhaps have any outstanding writes, or has
1282 			 * the file grown beyond our last write? */
1283 			if (nfsi->npages == 0 || new_isize > cur_isize) {
1284 				i_size_write(inode, new_isize);
1285 				invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA;
1286 			}
1287 			dprintk("NFS: isize change on server for file %s/%ld\n",
1288 					inode->i_sb->s_id, inode->i_ino);
1289 		}
1290 	} else
1291 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1292 				| NFS_INO_REVAL_PAGECACHE
1293 				| NFS_INO_REVAL_FORCED);
1294 
1295 
1296 	if (fattr->valid & NFS_ATTR_FATTR_ATIME)
1297 		memcpy(&inode->i_atime, &fattr->atime, sizeof(inode->i_atime));
1298 	else if (server->caps & NFS_CAP_ATIME)
1299 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATIME
1300 				| NFS_INO_REVAL_FORCED);
1301 
1302 	if (fattr->valid & NFS_ATTR_FATTR_MODE) {
1303 		if ((inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO)) {
1304 			umode_t newmode = inode->i_mode & S_IFMT;
1305 			newmode |= fattr->mode & S_IALLUGO;
1306 			inode->i_mode = newmode;
1307 			invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1308 		}
1309 	} else if (server->caps & NFS_CAP_MODE)
1310 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1311 				| NFS_INO_INVALID_ACCESS
1312 				| NFS_INO_INVALID_ACL
1313 				| NFS_INO_REVAL_FORCED);
1314 
1315 	if (fattr->valid & NFS_ATTR_FATTR_OWNER) {
1316 		if (inode->i_uid != fattr->uid) {
1317 			invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1318 			inode->i_uid = fattr->uid;
1319 		}
1320 	} else if (server->caps & NFS_CAP_OWNER)
1321 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1322 				| NFS_INO_INVALID_ACCESS
1323 				| NFS_INO_INVALID_ACL
1324 				| NFS_INO_REVAL_FORCED);
1325 
1326 	if (fattr->valid & NFS_ATTR_FATTR_GROUP) {
1327 		if (inode->i_gid != fattr->gid) {
1328 			invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1329 			inode->i_gid = fattr->gid;
1330 		}
1331 	} else if (server->caps & NFS_CAP_OWNER_GROUP)
1332 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1333 				| NFS_INO_INVALID_ACCESS
1334 				| NFS_INO_INVALID_ACL
1335 				| NFS_INO_REVAL_FORCED);
1336 
1337 	if (fattr->valid & NFS_ATTR_FATTR_NLINK) {
1338 		if (inode->i_nlink != fattr->nlink) {
1339 			invalid |= NFS_INO_INVALID_ATTR;
1340 			if (S_ISDIR(inode->i_mode))
1341 				invalid |= NFS_INO_INVALID_DATA;
1342 			inode->i_nlink = fattr->nlink;
1343 		}
1344 	} else if (server->caps & NFS_CAP_NLINK)
1345 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
1346 				| NFS_INO_REVAL_FORCED);
1347 
1348 	if (fattr->valid & NFS_ATTR_FATTR_SPACE_USED) {
1349 		/*
1350 		 * report the blocks in 512byte units
1351 		 */
1352 		inode->i_blocks = nfs_calc_block_size(fattr->du.nfs3.used);
1353  	}
1354 	if (fattr->valid & NFS_ATTR_FATTR_BLOCKS_USED)
1355 		inode->i_blocks = fattr->du.nfs2.blocks;
1356 
1357 	/* Update attrtimeo value if we're out of the unstable period */
1358 	if (invalid & NFS_INO_INVALID_ATTR) {
1359 		nfs_inc_stats(inode, NFSIOS_ATTRINVALIDATE);
1360 		nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
1361 		nfsi->attrtimeo_timestamp = now;
1362 		nfsi->attr_gencount = nfs_inc_attr_generation_counter();
1363 	} else {
1364 		if (!time_in_range_open(now, nfsi->attrtimeo_timestamp, nfsi->attrtimeo_timestamp + nfsi->attrtimeo)) {
1365 			if ((nfsi->attrtimeo <<= 1) > NFS_MAXATTRTIMEO(inode))
1366 				nfsi->attrtimeo = NFS_MAXATTRTIMEO(inode);
1367 			nfsi->attrtimeo_timestamp = now;
1368 		}
1369 	}
1370 	invalid &= ~NFS_INO_INVALID_ATTR;
1371 	/* Don't invalidate the data if we were to blame */
1372 	if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)
1373 				|| S_ISLNK(inode->i_mode)))
1374 		invalid &= ~NFS_INO_INVALID_DATA;
1375 	if (!nfs_have_delegation(inode, FMODE_READ) ||
1376 			(save_cache_validity & NFS_INO_REVAL_FORCED))
1377 		nfsi->cache_validity |= invalid;
1378 
1379 	return 0;
1380  out_changed:
1381 	/*
1382 	 * Big trouble! The inode has become a different object.
1383 	 */
1384 	printk(KERN_DEBUG "%s: inode %ld mode changed, %07o to %07o\n",
1385 			__func__, inode->i_ino, inode->i_mode, fattr->mode);
1386  out_err:
1387 	/*
1388 	 * No need to worry about unhashing the dentry, as the
1389 	 * lookup validation will know that the inode is bad.
1390 	 * (But we fall through to invalidate the caches.)
1391 	 */
1392 	nfs_invalidate_inode(inode);
1393 	return -ESTALE;
1394 
1395  out_fileid:
1396 	printk(KERN_ERR "NFS: server %s error: fileid changed\n"
1397 		"fsid %s: expected fileid 0x%Lx, got 0x%Lx\n",
1398 		NFS_SERVER(inode)->nfs_client->cl_hostname, inode->i_sb->s_id,
1399 		(long long)nfsi->fileid, (long long)fattr->fileid);
1400 	goto out_err;
1401 }
1402 
1403 
1404 #ifdef CONFIG_NFS_V4
1405 
1406 /*
1407  * Clean out any remaining NFSv4 state that might be left over due
1408  * to open() calls that passed nfs_atomic_lookup, but failed to call
1409  * nfs_open().
1410  */
1411 void nfs4_evict_inode(struct inode *inode)
1412 {
1413 	truncate_inode_pages(&inode->i_data, 0);
1414 	end_writeback(inode);
1415 	pnfs_destroy_layout(NFS_I(inode));
1416 	/* If we are holding a delegation, return it! */
1417 	nfs_inode_return_delegation_noreclaim(inode);
1418 	/* First call standard NFS clear_inode() code */
1419 	nfs_clear_inode(inode);
1420 }
1421 #endif
1422 
1423 struct inode *nfs_alloc_inode(struct super_block *sb)
1424 {
1425 	struct nfs_inode *nfsi;
1426 	nfsi = (struct nfs_inode *)kmem_cache_alloc(nfs_inode_cachep, GFP_KERNEL);
1427 	if (!nfsi)
1428 		return NULL;
1429 	nfsi->flags = 0UL;
1430 	nfsi->cache_validity = 0UL;
1431 #ifdef CONFIG_NFS_V3_ACL
1432 	nfsi->acl_access = ERR_PTR(-EAGAIN);
1433 	nfsi->acl_default = ERR_PTR(-EAGAIN);
1434 #endif
1435 #ifdef CONFIG_NFS_V4
1436 	nfsi->nfs4_acl = NULL;
1437 #endif /* CONFIG_NFS_V4 */
1438 	return &nfsi->vfs_inode;
1439 }
1440 
1441 void nfs_destroy_inode(struct inode *inode)
1442 {
1443 	kmem_cache_free(nfs_inode_cachep, NFS_I(inode));
1444 }
1445 
1446 static inline void nfs4_init_once(struct nfs_inode *nfsi)
1447 {
1448 #ifdef CONFIG_NFS_V4
1449 	INIT_LIST_HEAD(&nfsi->open_states);
1450 	nfsi->delegation = NULL;
1451 	nfsi->delegation_state = 0;
1452 	init_rwsem(&nfsi->rwsem);
1453 	nfsi->layout = NULL;
1454 #endif
1455 }
1456 
1457 static void init_once(void *foo)
1458 {
1459 	struct nfs_inode *nfsi = (struct nfs_inode *) foo;
1460 
1461 	inode_init_once(&nfsi->vfs_inode);
1462 	INIT_LIST_HEAD(&nfsi->open_files);
1463 	INIT_LIST_HEAD(&nfsi->access_cache_entry_lru);
1464 	INIT_LIST_HEAD(&nfsi->access_cache_inode_lru);
1465 	INIT_RADIX_TREE(&nfsi->nfs_page_tree, GFP_ATOMIC);
1466 	nfsi->npages = 0;
1467 	nfsi->ncommit = 0;
1468 	atomic_set(&nfsi->silly_count, 1);
1469 	INIT_HLIST_HEAD(&nfsi->silly_list);
1470 	init_waitqueue_head(&nfsi->waitqueue);
1471 	nfs4_init_once(nfsi);
1472 }
1473 
1474 static int __init nfs_init_inodecache(void)
1475 {
1476 	nfs_inode_cachep = kmem_cache_create("nfs_inode_cache",
1477 					     sizeof(struct nfs_inode),
1478 					     0, (SLAB_RECLAIM_ACCOUNT|
1479 						SLAB_MEM_SPREAD),
1480 					     init_once);
1481 	if (nfs_inode_cachep == NULL)
1482 		return -ENOMEM;
1483 
1484 	return 0;
1485 }
1486 
1487 static void nfs_destroy_inodecache(void)
1488 {
1489 	kmem_cache_destroy(nfs_inode_cachep);
1490 }
1491 
1492 struct workqueue_struct *nfsiod_workqueue;
1493 
1494 /*
1495  * start up the nfsiod workqueue
1496  */
1497 static int nfsiod_start(void)
1498 {
1499 	struct workqueue_struct *wq;
1500 	dprintk("RPC:       creating workqueue nfsiod\n");
1501 	wq = alloc_workqueue("nfsiod", WQ_RESCUER, 0);
1502 	if (wq == NULL)
1503 		return -ENOMEM;
1504 	nfsiod_workqueue = wq;
1505 	return 0;
1506 }
1507 
1508 /*
1509  * Destroy the nfsiod workqueue
1510  */
1511 static void nfsiod_stop(void)
1512 {
1513 	struct workqueue_struct *wq;
1514 
1515 	wq = nfsiod_workqueue;
1516 	if (wq == NULL)
1517 		return;
1518 	nfsiod_workqueue = NULL;
1519 	destroy_workqueue(wq);
1520 }
1521 
1522 /*
1523  * Initialize NFS
1524  */
1525 static int __init init_nfs_fs(void)
1526 {
1527 	int err;
1528 
1529 	err = nfs_idmap_init();
1530 	if (err < 0)
1531 		goto out9;
1532 
1533 	err = nfs_dns_resolver_init();
1534 	if (err < 0)
1535 		goto out8;
1536 
1537 	err = nfs_fscache_register();
1538 	if (err < 0)
1539 		goto out7;
1540 
1541 	err = nfsiod_start();
1542 	if (err)
1543 		goto out6;
1544 
1545 	err = nfs_fs_proc_init();
1546 	if (err)
1547 		goto out5;
1548 
1549 	err = nfs_init_nfspagecache();
1550 	if (err)
1551 		goto out4;
1552 
1553 	err = nfs_init_inodecache();
1554 	if (err)
1555 		goto out3;
1556 
1557 	err = nfs_init_readpagecache();
1558 	if (err)
1559 		goto out2;
1560 
1561 	err = nfs_init_writepagecache();
1562 	if (err)
1563 		goto out1;
1564 
1565 	err = nfs_init_directcache();
1566 	if (err)
1567 		goto out0;
1568 
1569 #ifdef CONFIG_PROC_FS
1570 	rpc_proc_register(&nfs_rpcstat);
1571 #endif
1572 	if ((err = register_nfs_fs()) != 0)
1573 		goto out;
1574 	return 0;
1575 out:
1576 #ifdef CONFIG_PROC_FS
1577 	rpc_proc_unregister("nfs");
1578 #endif
1579 	nfs_destroy_directcache();
1580 out0:
1581 	nfs_destroy_writepagecache();
1582 out1:
1583 	nfs_destroy_readpagecache();
1584 out2:
1585 	nfs_destroy_inodecache();
1586 out3:
1587 	nfs_destroy_nfspagecache();
1588 out4:
1589 	nfs_fs_proc_exit();
1590 out5:
1591 	nfsiod_stop();
1592 out6:
1593 	nfs_fscache_unregister();
1594 out7:
1595 	nfs_dns_resolver_destroy();
1596 out8:
1597 	nfs_idmap_quit();
1598 out9:
1599 	return err;
1600 }
1601 
1602 static void __exit exit_nfs_fs(void)
1603 {
1604 	nfs_destroy_directcache();
1605 	nfs_destroy_writepagecache();
1606 	nfs_destroy_readpagecache();
1607 	nfs_destroy_inodecache();
1608 	nfs_destroy_nfspagecache();
1609 	nfs_fscache_unregister();
1610 	nfs_dns_resolver_destroy();
1611 	nfs_idmap_quit();
1612 #ifdef CONFIG_PROC_FS
1613 	rpc_proc_unregister("nfs");
1614 #endif
1615 	unregister_nfs_fs();
1616 	nfs_fs_proc_exit();
1617 	nfsiod_stop();
1618 }
1619 
1620 /* Not quite true; I just maintain it */
1621 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
1622 MODULE_LICENSE("GPL");
1623 module_param(enable_ino64, bool, 0644);
1624 
1625 module_init(init_nfs_fs)
1626 module_exit(exit_nfs_fs)
1627