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1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  linux/fs/nfs/inode.c
4  *
5  *  Copyright (C) 1992  Rick Sladkey
6  *
7  *  nfs inode and superblock handling functions
8  *
9  *  Modularised by Alan Cox <alan@lxorguk.ukuu.org.uk>, while hacking some
10  *  experimental NFS changes. Modularisation taken straight from SYS5 fs.
11  *
12  *  Change to nfs_read_super() to permit NFS mounts to multi-homed hosts.
13  *  J.S.Peatfield@damtp.cam.ac.uk
14  *
15  */
16 
17 #include <linux/module.h>
18 #include <linux/init.h>
19 #include <linux/sched/signal.h>
20 #include <linux/time.h>
21 #include <linux/kernel.h>
22 #include <linux/mm.h>
23 #include <linux/string.h>
24 #include <linux/stat.h>
25 #include <linux/errno.h>
26 #include <linux/unistd.h>
27 #include <linux/sunrpc/clnt.h>
28 #include <linux/sunrpc/stats.h>
29 #include <linux/sunrpc/metrics.h>
30 #include <linux/nfs_fs.h>
31 #include <linux/nfs_mount.h>
32 #include <linux/nfs4_mount.h>
33 #include <linux/lockd/bind.h>
34 #include <linux/seq_file.h>
35 #include <linux/mount.h>
36 #include <linux/vfs.h>
37 #include <linux/inet.h>
38 #include <linux/nfs_xdr.h>
39 #include <linux/slab.h>
40 #include <linux/compat.h>
41 #include <linux/freezer.h>
42 #include <linux/uaccess.h>
43 #include <linux/iversion.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 "pnfs.h"
52 #include "nfs.h"
53 #include "netns.h"
54 #include "sysfs.h"
55 
56 #include "nfstrace.h"
57 
58 #define NFSDBG_FACILITY		NFSDBG_VFS
59 
60 #define NFS_64_BIT_INODE_NUMBERS_ENABLED	1
61 
62 /* Default is to see 64-bit inode numbers */
63 static bool enable_ino64 = NFS_64_BIT_INODE_NUMBERS_ENABLED;
64 
65 static int nfs_update_inode(struct inode *, struct nfs_fattr *);
66 
67 static struct kmem_cache * nfs_inode_cachep;
68 
69 static inline unsigned long
nfs_fattr_to_ino_t(struct nfs_fattr * fattr)70 nfs_fattr_to_ino_t(struct nfs_fattr *fattr)
71 {
72 	return nfs_fileid_to_ino_t(fattr->fileid);
73 }
74 
nfs_wait_bit_killable(struct wait_bit_key * key,int mode)75 int nfs_wait_bit_killable(struct wait_bit_key *key, int mode)
76 {
77 	schedule();
78 	if (signal_pending_state(mode, current))
79 		return -ERESTARTSYS;
80 	return 0;
81 }
82 EXPORT_SYMBOL_GPL(nfs_wait_bit_killable);
83 
84 /**
85  * nfs_compat_user_ino64 - returns the user-visible inode number
86  * @fileid: 64-bit fileid
87  *
88  * This function returns a 32-bit inode number if the boot parameter
89  * nfs.enable_ino64 is zero.
90  */
nfs_compat_user_ino64(u64 fileid)91 u64 nfs_compat_user_ino64(u64 fileid)
92 {
93 #ifdef CONFIG_COMPAT
94 	compat_ulong_t ino;
95 #else
96 	unsigned long ino;
97 #endif
98 
99 	if (enable_ino64)
100 		return fileid;
101 	ino = fileid;
102 	if (sizeof(ino) < sizeof(fileid))
103 		ino ^= fileid >> (sizeof(fileid)-sizeof(ino)) * 8;
104 	return ino;
105 }
106 
nfs_drop_inode(struct inode * inode)107 int nfs_drop_inode(struct inode *inode)
108 {
109 	return NFS_STALE(inode) || generic_drop_inode(inode);
110 }
111 EXPORT_SYMBOL_GPL(nfs_drop_inode);
112 
nfs_clear_inode(struct inode * inode)113 void nfs_clear_inode(struct inode *inode)
114 {
115 	/*
116 	 * The following should never happen...
117 	 */
118 	WARN_ON_ONCE(nfs_have_writebacks(inode));
119 	WARN_ON_ONCE(!list_empty(&NFS_I(inode)->open_files));
120 	nfs_zap_acl_cache(inode);
121 	nfs_access_zap_cache(inode);
122 	nfs_fscache_clear_inode(inode);
123 }
124 EXPORT_SYMBOL_GPL(nfs_clear_inode);
125 
nfs_evict_inode(struct inode * inode)126 void nfs_evict_inode(struct inode *inode)
127 {
128 	truncate_inode_pages_final(&inode->i_data);
129 	clear_inode(inode);
130 	nfs_clear_inode(inode);
131 }
132 
nfs_sync_inode(struct inode * inode)133 int nfs_sync_inode(struct inode *inode)
134 {
135 	inode_dio_wait(inode);
136 	return nfs_wb_all(inode);
137 }
138 EXPORT_SYMBOL_GPL(nfs_sync_inode);
139 
140 /**
141  * nfs_sync_mapping - helper to flush all mmapped dirty data to disk
142  * @mapping: pointer to struct address_space
143  */
nfs_sync_mapping(struct address_space * mapping)144 int nfs_sync_mapping(struct address_space *mapping)
145 {
146 	int ret = 0;
147 
148 	if (mapping->nrpages != 0) {
149 		unmap_mapping_range(mapping, 0, 0, 0);
150 		ret = nfs_wb_all(mapping->host);
151 	}
152 	return ret;
153 }
154 
nfs_attribute_timeout(struct inode * inode)155 static int nfs_attribute_timeout(struct inode *inode)
156 {
157 	struct nfs_inode *nfsi = NFS_I(inode);
158 
159 	return !time_in_range_open(jiffies, nfsi->read_cache_jiffies, nfsi->read_cache_jiffies + nfsi->attrtimeo);
160 }
161 
nfs_check_cache_flags_invalid(struct inode * inode,unsigned long flags)162 static bool nfs_check_cache_flags_invalid(struct inode *inode,
163 					  unsigned long flags)
164 {
165 	unsigned long cache_validity = READ_ONCE(NFS_I(inode)->cache_validity);
166 
167 	return (cache_validity & flags) != 0;
168 }
169 
nfs_check_cache_invalid(struct inode * inode,unsigned long flags)170 bool nfs_check_cache_invalid(struct inode *inode, unsigned long flags)
171 {
172 	if (nfs_check_cache_flags_invalid(inode, flags))
173 		return true;
174 	return nfs_attribute_cache_expired(inode);
175 }
176 EXPORT_SYMBOL_GPL(nfs_check_cache_invalid);
177 
178 #ifdef CONFIG_NFS_V4_2
nfs_has_xattr_cache(const struct nfs_inode * nfsi)179 static bool nfs_has_xattr_cache(const struct nfs_inode *nfsi)
180 {
181 	return nfsi->xattr_cache != NULL;
182 }
183 #else
nfs_has_xattr_cache(const struct nfs_inode * nfsi)184 static bool nfs_has_xattr_cache(const struct nfs_inode *nfsi)
185 {
186 	return false;
187 }
188 #endif
189 
nfs_set_cache_invalid(struct inode * inode,unsigned long flags)190 void nfs_set_cache_invalid(struct inode *inode, unsigned long flags)
191 {
192 	struct nfs_inode *nfsi = NFS_I(inode);
193 	bool have_delegation = NFS_PROTO(inode)->have_delegation(inode, FMODE_READ);
194 
195 	if (have_delegation) {
196 		if (!(flags & NFS_INO_REVAL_FORCED))
197 			flags &= ~(NFS_INO_INVALID_MODE |
198 				   NFS_INO_INVALID_OTHER |
199 				   NFS_INO_INVALID_XATTR);
200 		flags &= ~(NFS_INO_INVALID_CHANGE | NFS_INO_INVALID_SIZE);
201 	}
202 
203 	if (!nfs_has_xattr_cache(nfsi))
204 		flags &= ~NFS_INO_INVALID_XATTR;
205 	if (flags & NFS_INO_INVALID_DATA)
206 		nfs_fscache_invalidate(inode, 0);
207 	flags &= ~NFS_INO_REVAL_FORCED;
208 
209 	nfsi->cache_validity |= flags;
210 
211 	if (inode->i_mapping->nrpages == 0)
212 		nfsi->cache_validity &= ~(NFS_INO_INVALID_DATA |
213 					  NFS_INO_DATA_INVAL_DEFER);
214 	else if (nfsi->cache_validity & NFS_INO_INVALID_DATA)
215 		nfsi->cache_validity &= ~NFS_INO_DATA_INVAL_DEFER;
216 	trace_nfs_set_cache_invalid(inode, 0);
217 }
218 EXPORT_SYMBOL_GPL(nfs_set_cache_invalid);
219 
220 /*
221  * Invalidate the local caches
222  */
nfs_zap_caches_locked(struct inode * inode)223 static void nfs_zap_caches_locked(struct inode *inode)
224 {
225 	struct nfs_inode *nfsi = NFS_I(inode);
226 	int mode = inode->i_mode;
227 
228 	nfs_inc_stats(inode, NFSIOS_ATTRINVALIDATE);
229 
230 	nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
231 	nfsi->attrtimeo_timestamp = jiffies;
232 
233 	if (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))
234 		nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR |
235 						     NFS_INO_INVALID_DATA |
236 						     NFS_INO_INVALID_ACCESS |
237 						     NFS_INO_INVALID_ACL |
238 						     NFS_INO_INVALID_XATTR);
239 	else
240 		nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR |
241 						     NFS_INO_INVALID_ACCESS |
242 						     NFS_INO_INVALID_ACL |
243 						     NFS_INO_INVALID_XATTR);
244 	nfs_zap_label_cache_locked(nfsi);
245 }
246 
nfs_zap_caches(struct inode * inode)247 void nfs_zap_caches(struct inode *inode)
248 {
249 	spin_lock(&inode->i_lock);
250 	nfs_zap_caches_locked(inode);
251 	spin_unlock(&inode->i_lock);
252 }
253 
nfs_zap_mapping(struct inode * inode,struct address_space * mapping)254 void nfs_zap_mapping(struct inode *inode, struct address_space *mapping)
255 {
256 	if (mapping->nrpages != 0) {
257 		spin_lock(&inode->i_lock);
258 		nfs_set_cache_invalid(inode, NFS_INO_INVALID_DATA);
259 		spin_unlock(&inode->i_lock);
260 	}
261 }
262 
nfs_zap_acl_cache(struct inode * inode)263 void nfs_zap_acl_cache(struct inode *inode)
264 {
265 	void (*clear_acl_cache)(struct inode *);
266 
267 	clear_acl_cache = NFS_PROTO(inode)->clear_acl_cache;
268 	if (clear_acl_cache != NULL)
269 		clear_acl_cache(inode);
270 	spin_lock(&inode->i_lock);
271 	NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_ACL;
272 	spin_unlock(&inode->i_lock);
273 }
274 EXPORT_SYMBOL_GPL(nfs_zap_acl_cache);
275 
nfs_invalidate_atime(struct inode * inode)276 void nfs_invalidate_atime(struct inode *inode)
277 {
278 	spin_lock(&inode->i_lock);
279 	nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATIME);
280 	spin_unlock(&inode->i_lock);
281 }
282 EXPORT_SYMBOL_GPL(nfs_invalidate_atime);
283 
284 /*
285  * Invalidate, but do not unhash, the inode.
286  * NB: must be called with inode->i_lock held!
287  */
nfs_set_inode_stale_locked(struct inode * inode)288 static void nfs_set_inode_stale_locked(struct inode *inode)
289 {
290 	set_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
291 	nfs_zap_caches_locked(inode);
292 	trace_nfs_set_inode_stale(inode);
293 }
294 
nfs_set_inode_stale(struct inode * inode)295 void nfs_set_inode_stale(struct inode *inode)
296 {
297 	spin_lock(&inode->i_lock);
298 	nfs_set_inode_stale_locked(inode);
299 	spin_unlock(&inode->i_lock);
300 }
301 
302 struct nfs_find_desc {
303 	struct nfs_fh		*fh;
304 	struct nfs_fattr	*fattr;
305 };
306 
307 /*
308  * In NFSv3 we can have 64bit inode numbers. In order to support
309  * this, and re-exported directories (also seen in NFSv2)
310  * we are forced to allow 2 different inodes to have the same
311  * i_ino.
312  */
313 static int
nfs_find_actor(struct inode * inode,void * opaque)314 nfs_find_actor(struct inode *inode, void *opaque)
315 {
316 	struct nfs_find_desc	*desc = opaque;
317 	struct nfs_fh		*fh = desc->fh;
318 	struct nfs_fattr	*fattr = desc->fattr;
319 
320 	if (NFS_FILEID(inode) != fattr->fileid)
321 		return 0;
322 	if (inode_wrong_type(inode, fattr->mode))
323 		return 0;
324 	if (nfs_compare_fh(NFS_FH(inode), fh))
325 		return 0;
326 	if (is_bad_inode(inode) || NFS_STALE(inode))
327 		return 0;
328 	return 1;
329 }
330 
331 static int
nfs_init_locked(struct inode * inode,void * opaque)332 nfs_init_locked(struct inode *inode, void *opaque)
333 {
334 	struct nfs_find_desc	*desc = opaque;
335 	struct nfs_fattr	*fattr = desc->fattr;
336 
337 	set_nfs_fileid(inode, fattr->fileid);
338 	inode->i_mode = fattr->mode;
339 	nfs_copy_fh(NFS_FH(inode), desc->fh);
340 	return 0;
341 }
342 
343 #ifdef CONFIG_NFS_V4_SECURITY_LABEL
nfs_clear_label_invalid(struct inode * inode)344 static void nfs_clear_label_invalid(struct inode *inode)
345 {
346 	spin_lock(&inode->i_lock);
347 	NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_LABEL;
348 	spin_unlock(&inode->i_lock);
349 }
350 
nfs_setsecurity(struct inode * inode,struct nfs_fattr * fattr)351 void nfs_setsecurity(struct inode *inode, struct nfs_fattr *fattr)
352 {
353 	int error;
354 
355 	if (fattr->label == NULL)
356 		return;
357 
358 	if ((fattr->valid & NFS_ATTR_FATTR_V4_SECURITY_LABEL) && inode->i_security) {
359 		error = security_inode_notifysecctx(inode, fattr->label->label,
360 				fattr->label->len);
361 		if (error)
362 			printk(KERN_ERR "%s() %s %d "
363 					"security_inode_notifysecctx() %d\n",
364 					__func__,
365 					(char *)fattr->label->label,
366 					fattr->label->len, error);
367 		nfs_clear_label_invalid(inode);
368 	}
369 }
370 
nfs4_label_alloc(struct nfs_server * server,gfp_t flags)371 struct nfs4_label *nfs4_label_alloc(struct nfs_server *server, gfp_t flags)
372 {
373 	struct nfs4_label *label;
374 
375 	if (!(server->caps & NFS_CAP_SECURITY_LABEL))
376 		return NULL;
377 
378 	label = kzalloc(sizeof(struct nfs4_label), flags);
379 	if (label == NULL)
380 		return ERR_PTR(-ENOMEM);
381 
382 	label->label = kzalloc(NFS4_MAXLABELLEN, flags);
383 	if (label->label == NULL) {
384 		kfree(label);
385 		return ERR_PTR(-ENOMEM);
386 	}
387 	label->len = NFS4_MAXLABELLEN;
388 
389 	return label;
390 }
391 EXPORT_SYMBOL_GPL(nfs4_label_alloc);
392 #else
nfs_setsecurity(struct inode * inode,struct nfs_fattr * fattr)393 void nfs_setsecurity(struct inode *inode, struct nfs_fattr *fattr)
394 {
395 }
396 #endif
397 EXPORT_SYMBOL_GPL(nfs_setsecurity);
398 
399 /* Search for inode identified by fh, fileid and i_mode in inode cache. */
400 struct inode *
nfs_ilookup(struct super_block * sb,struct nfs_fattr * fattr,struct nfs_fh * fh)401 nfs_ilookup(struct super_block *sb, struct nfs_fattr *fattr, struct nfs_fh *fh)
402 {
403 	struct nfs_find_desc desc = {
404 		.fh	= fh,
405 		.fattr	= fattr,
406 	};
407 	struct inode *inode;
408 	unsigned long hash;
409 
410 	if (!(fattr->valid & NFS_ATTR_FATTR_FILEID) ||
411 	    !(fattr->valid & NFS_ATTR_FATTR_TYPE))
412 		return NULL;
413 
414 	hash = nfs_fattr_to_ino_t(fattr);
415 	inode = ilookup5(sb, hash, nfs_find_actor, &desc);
416 
417 	dprintk("%s: returning %p\n", __func__, inode);
418 	return inode;
419 }
420 
nfs_inode_init_regular(struct nfs_inode * nfsi)421 static void nfs_inode_init_regular(struct nfs_inode *nfsi)
422 {
423 	atomic_long_set(&nfsi->nrequests, 0);
424 	atomic_long_set(&nfsi->redirtied_pages, 0);
425 	INIT_LIST_HEAD(&nfsi->commit_info.list);
426 	atomic_long_set(&nfsi->commit_info.ncommit, 0);
427 	atomic_set(&nfsi->commit_info.rpcs_out, 0);
428 	mutex_init(&nfsi->commit_mutex);
429 }
430 
nfs_inode_init_dir(struct nfs_inode * nfsi)431 static void nfs_inode_init_dir(struct nfs_inode *nfsi)
432 {
433 	nfsi->cache_change_attribute = 0;
434 	memset(nfsi->cookieverf, 0, sizeof(nfsi->cookieverf));
435 	init_rwsem(&nfsi->rmdir_sem);
436 }
437 
438 /*
439  * This is our front-end to iget that looks up inodes by file handle
440  * instead of inode number.
441  */
442 struct inode *
nfs_fhget(struct super_block * sb,struct nfs_fh * fh,struct nfs_fattr * fattr)443 nfs_fhget(struct super_block *sb, struct nfs_fh *fh, struct nfs_fattr *fattr)
444 {
445 	struct nfs_find_desc desc = {
446 		.fh	= fh,
447 		.fattr	= fattr
448 	};
449 	struct inode *inode = ERR_PTR(-ENOENT);
450 	u64 fattr_supported = NFS_SB(sb)->fattr_valid;
451 	unsigned long hash;
452 
453 	nfs_attr_check_mountpoint(sb, fattr);
454 
455 	if (nfs_attr_use_mounted_on_fileid(fattr))
456 		fattr->fileid = fattr->mounted_on_fileid;
457 	else if ((fattr->valid & NFS_ATTR_FATTR_FILEID) == 0)
458 		goto out_no_inode;
459 	if ((fattr->valid & NFS_ATTR_FATTR_TYPE) == 0)
460 		goto out_no_inode;
461 
462 	hash = nfs_fattr_to_ino_t(fattr);
463 
464 	inode = iget5_locked(sb, hash, nfs_find_actor, nfs_init_locked, &desc);
465 	if (inode == NULL) {
466 		inode = ERR_PTR(-ENOMEM);
467 		goto out_no_inode;
468 	}
469 
470 	if (inode->i_state & I_NEW) {
471 		struct nfs_inode *nfsi = NFS_I(inode);
472 		unsigned long now = jiffies;
473 
474 		/* We set i_ino for the few things that still rely on it,
475 		 * such as stat(2) */
476 		inode->i_ino = hash;
477 
478 		/* We can't support update_atime(), since the server will reset it */
479 		inode->i_flags |= S_NOATIME|S_NOCMTIME;
480 		inode->i_mode = fattr->mode;
481 		nfsi->cache_validity = 0;
482 		if ((fattr->valid & NFS_ATTR_FATTR_MODE) == 0
483 				&& (fattr_supported & NFS_ATTR_FATTR_MODE))
484 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_MODE);
485 		/* Why so? Because we want revalidate for devices/FIFOs, and
486 		 * that's precisely what we have in nfs_file_inode_operations.
487 		 */
488 		inode->i_op = NFS_SB(sb)->nfs_client->rpc_ops->file_inode_ops;
489 		if (S_ISREG(inode->i_mode)) {
490 			inode->i_fop = NFS_SB(sb)->nfs_client->rpc_ops->file_ops;
491 			inode->i_data.a_ops = &nfs_file_aops;
492 			nfs_inode_init_regular(nfsi);
493 		} else if (S_ISDIR(inode->i_mode)) {
494 			inode->i_op = NFS_SB(sb)->nfs_client->rpc_ops->dir_inode_ops;
495 			inode->i_fop = &nfs_dir_operations;
496 			inode->i_data.a_ops = &nfs_dir_aops;
497 			nfs_inode_init_dir(nfsi);
498 			/* Deal with crossing mountpoints */
499 			if (fattr->valid & NFS_ATTR_FATTR_MOUNTPOINT ||
500 					fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL) {
501 				if (fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL)
502 					inode->i_op = &nfs_referral_inode_operations;
503 				else
504 					inode->i_op = &nfs_mountpoint_inode_operations;
505 				inode->i_fop = NULL;
506 				inode->i_flags |= S_AUTOMOUNT;
507 			}
508 		} else if (S_ISLNK(inode->i_mode)) {
509 			inode->i_op = &nfs_symlink_inode_operations;
510 			inode_nohighmem(inode);
511 		} else
512 			init_special_inode(inode, inode->i_mode, fattr->rdev);
513 
514 		memset(&inode->i_atime, 0, sizeof(inode->i_atime));
515 		memset(&inode->i_mtime, 0, sizeof(inode->i_mtime));
516 		memset(&inode->i_ctime, 0, sizeof(inode->i_ctime));
517 		inode_set_iversion_raw(inode, 0);
518 		inode->i_size = 0;
519 		clear_nlink(inode);
520 		inode->i_uid = make_kuid(&init_user_ns, -2);
521 		inode->i_gid = make_kgid(&init_user_ns, -2);
522 		inode->i_blocks = 0;
523 		nfsi->write_io = 0;
524 		nfsi->read_io = 0;
525 
526 		nfsi->read_cache_jiffies = fattr->time_start;
527 		nfsi->attr_gencount = fattr->gencount;
528 		if (fattr->valid & NFS_ATTR_FATTR_ATIME)
529 			inode->i_atime = fattr->atime;
530 		else if (fattr_supported & NFS_ATTR_FATTR_ATIME)
531 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATIME);
532 		if (fattr->valid & NFS_ATTR_FATTR_MTIME)
533 			inode->i_mtime = fattr->mtime;
534 		else if (fattr_supported & NFS_ATTR_FATTR_MTIME)
535 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_MTIME);
536 		if (fattr->valid & NFS_ATTR_FATTR_CTIME)
537 			inode->i_ctime = fattr->ctime;
538 		else if (fattr_supported & NFS_ATTR_FATTR_CTIME)
539 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_CTIME);
540 		if (fattr->valid & NFS_ATTR_FATTR_CHANGE)
541 			inode_set_iversion_raw(inode, fattr->change_attr);
542 		else
543 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_CHANGE);
544 		if (fattr->valid & NFS_ATTR_FATTR_SIZE)
545 			inode->i_size = nfs_size_to_loff_t(fattr->size);
546 		else
547 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_SIZE);
548 		if (fattr->valid & NFS_ATTR_FATTR_NLINK)
549 			set_nlink(inode, fattr->nlink);
550 		else if (fattr_supported & NFS_ATTR_FATTR_NLINK)
551 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_NLINK);
552 		if (fattr->valid & NFS_ATTR_FATTR_OWNER)
553 			inode->i_uid = fattr->uid;
554 		else if (fattr_supported & NFS_ATTR_FATTR_OWNER)
555 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_OTHER);
556 		if (fattr->valid & NFS_ATTR_FATTR_GROUP)
557 			inode->i_gid = fattr->gid;
558 		else if (fattr_supported & NFS_ATTR_FATTR_GROUP)
559 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_OTHER);
560 		if (fattr->valid & NFS_ATTR_FATTR_BLOCKS_USED)
561 			inode->i_blocks = fattr->du.nfs2.blocks;
562 		else if (fattr_supported & NFS_ATTR_FATTR_BLOCKS_USED &&
563 			 fattr->size != 0)
564 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_BLOCKS);
565 		if (fattr->valid & NFS_ATTR_FATTR_SPACE_USED) {
566 			/*
567 			 * report the blocks in 512byte units
568 			 */
569 			inode->i_blocks = nfs_calc_block_size(fattr->du.nfs3.used);
570 		} else if (fattr_supported & NFS_ATTR_FATTR_SPACE_USED &&
571 			   fattr->size != 0)
572 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_BLOCKS);
573 
574 		nfs_setsecurity(inode, fattr);
575 
576 		nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
577 		nfsi->attrtimeo_timestamp = now;
578 		nfsi->access_cache = RB_ROOT;
579 
580 		nfs_fscache_init_inode(inode);
581 
582 		unlock_new_inode(inode);
583 	} else {
584 		int err = nfs_refresh_inode(inode, fattr);
585 		if (err < 0) {
586 			iput(inode);
587 			inode = ERR_PTR(err);
588 			goto out_no_inode;
589 		}
590 	}
591 	dprintk("NFS: nfs_fhget(%s/%Lu fh_crc=0x%08x ct=%d)\n",
592 		inode->i_sb->s_id,
593 		(unsigned long long)NFS_FILEID(inode),
594 		nfs_display_fhandle_hash(fh),
595 		atomic_read(&inode->i_count));
596 
597 out:
598 	return inode;
599 
600 out_no_inode:
601 	dprintk("nfs_fhget: iget failed with error %ld\n", PTR_ERR(inode));
602 	goto out;
603 }
604 EXPORT_SYMBOL_GPL(nfs_fhget);
605 
606 #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)
607 
608 int
nfs_setattr(struct user_namespace * mnt_userns,struct dentry * dentry,struct iattr * attr)609 nfs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
610 	    struct iattr *attr)
611 {
612 	struct inode *inode = d_inode(dentry);
613 	struct nfs_fattr *fattr;
614 	int error = 0;
615 
616 	nfs_inc_stats(inode, NFSIOS_VFSSETATTR);
617 
618 	/* skip mode change if it's just for clearing setuid/setgid */
619 	if (attr->ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
620 		attr->ia_valid &= ~ATTR_MODE;
621 
622 	if (attr->ia_valid & ATTR_SIZE) {
623 		BUG_ON(!S_ISREG(inode->i_mode));
624 
625 		error = inode_newsize_ok(inode, attr->ia_size);
626 		if (error)
627 			return error;
628 
629 		if (attr->ia_size == i_size_read(inode))
630 			attr->ia_valid &= ~ATTR_SIZE;
631 	}
632 
633 	/* Optimization: if the end result is no change, don't RPC */
634 	if (((attr->ia_valid & NFS_VALID_ATTRS) & ~(ATTR_FILE|ATTR_OPEN)) == 0)
635 		return 0;
636 
637 	trace_nfs_setattr_enter(inode);
638 
639 	/* Write all dirty data */
640 	if (S_ISREG(inode->i_mode))
641 		nfs_sync_inode(inode);
642 
643 	fattr = nfs_alloc_fattr_with_label(NFS_SERVER(inode));
644 	if (fattr == NULL) {
645 		error = -ENOMEM;
646 		goto out;
647 	}
648 
649 	error = NFS_PROTO(inode)->setattr(dentry, fattr, attr);
650 	if (error == 0)
651 		error = nfs_refresh_inode(inode, fattr);
652 	nfs_free_fattr(fattr);
653 out:
654 	trace_nfs_setattr_exit(inode, error);
655 	return error;
656 }
657 EXPORT_SYMBOL_GPL(nfs_setattr);
658 
659 /**
660  * nfs_vmtruncate - unmap mappings "freed" by truncate() syscall
661  * @inode: inode of the file used
662  * @offset: file offset to start truncating
663  *
664  * This is a copy of the common vmtruncate, but with the locking
665  * corrected to take into account the fact that NFS requires
666  * inode->i_size to be updated under the inode->i_lock.
667  * Note: must be called with inode->i_lock held!
668  */
nfs_vmtruncate(struct inode * inode,loff_t offset)669 static int nfs_vmtruncate(struct inode * inode, loff_t offset)
670 {
671 	int err;
672 
673 	err = inode_newsize_ok(inode, offset);
674 	if (err)
675 		goto out;
676 
677 	trace_nfs_size_truncate(inode, offset);
678 	i_size_write(inode, offset);
679 	/* Optimisation */
680 	if (offset == 0)
681 		NFS_I(inode)->cache_validity &= ~(NFS_INO_INVALID_DATA |
682 				NFS_INO_DATA_INVAL_DEFER);
683 	NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_SIZE;
684 
685 	spin_unlock(&inode->i_lock);
686 	truncate_pagecache(inode, offset);
687 	spin_lock(&inode->i_lock);
688 out:
689 	return err;
690 }
691 
692 /**
693  * nfs_setattr_update_inode - Update inode metadata after a setattr call.
694  * @inode: pointer to struct inode
695  * @attr: pointer to struct iattr
696  * @fattr: pointer to struct nfs_fattr
697  *
698  * Note: we do this in the *proc.c in order to ensure that
699  *       it works for things like exclusive creates too.
700  */
nfs_setattr_update_inode(struct inode * inode,struct iattr * attr,struct nfs_fattr * fattr)701 void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr,
702 		struct nfs_fattr *fattr)
703 {
704 	/* Barrier: bump the attribute generation count. */
705 	nfs_fattr_set_barrier(fattr);
706 
707 	spin_lock(&inode->i_lock);
708 	NFS_I(inode)->attr_gencount = fattr->gencount;
709 	if ((attr->ia_valid & ATTR_SIZE) != 0) {
710 		nfs_set_cache_invalid(inode, NFS_INO_INVALID_MTIME |
711 						     NFS_INO_INVALID_BLOCKS);
712 		nfs_inc_stats(inode, NFSIOS_SETATTRTRUNC);
713 		nfs_vmtruncate(inode, attr->ia_size);
714 	}
715 	if ((attr->ia_valid & (ATTR_MODE|ATTR_UID|ATTR_GID)) != 0) {
716 		NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_CTIME;
717 		if ((attr->ia_valid & ATTR_KILL_SUID) != 0 &&
718 		    inode->i_mode & S_ISUID)
719 			inode->i_mode &= ~S_ISUID;
720 		if (setattr_should_drop_sgid(&init_user_ns, inode))
721 			inode->i_mode &= ~S_ISGID;
722 		if ((attr->ia_valid & ATTR_MODE) != 0) {
723 			int mode = attr->ia_mode & S_IALLUGO;
724 			mode |= inode->i_mode & ~S_IALLUGO;
725 			inode->i_mode = mode;
726 		}
727 		if ((attr->ia_valid & ATTR_UID) != 0)
728 			inode->i_uid = attr->ia_uid;
729 		if ((attr->ia_valid & ATTR_GID) != 0)
730 			inode->i_gid = attr->ia_gid;
731 		if (fattr->valid & NFS_ATTR_FATTR_CTIME)
732 			inode->i_ctime = fattr->ctime;
733 		else
734 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_CHANGE
735 					| NFS_INO_INVALID_CTIME);
736 		nfs_set_cache_invalid(inode, NFS_INO_INVALID_ACCESS
737 				| NFS_INO_INVALID_ACL);
738 	}
739 	if (attr->ia_valid & (ATTR_ATIME_SET|ATTR_ATIME)) {
740 		NFS_I(inode)->cache_validity &= ~(NFS_INO_INVALID_ATIME
741 				| NFS_INO_INVALID_CTIME);
742 		if (fattr->valid & NFS_ATTR_FATTR_ATIME)
743 			inode->i_atime = fattr->atime;
744 		else if (attr->ia_valid & ATTR_ATIME_SET)
745 			inode->i_atime = attr->ia_atime;
746 		else
747 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATIME);
748 
749 		if (fattr->valid & NFS_ATTR_FATTR_CTIME)
750 			inode->i_ctime = fattr->ctime;
751 		else
752 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_CHANGE
753 					| NFS_INO_INVALID_CTIME);
754 	}
755 	if (attr->ia_valid & (ATTR_MTIME_SET|ATTR_MTIME)) {
756 		NFS_I(inode)->cache_validity &= ~(NFS_INO_INVALID_MTIME
757 				| NFS_INO_INVALID_CTIME);
758 		if (fattr->valid & NFS_ATTR_FATTR_MTIME)
759 			inode->i_mtime = fattr->mtime;
760 		else if (attr->ia_valid & ATTR_MTIME_SET)
761 			inode->i_mtime = attr->ia_mtime;
762 		else
763 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_MTIME);
764 
765 		if (fattr->valid & NFS_ATTR_FATTR_CTIME)
766 			inode->i_ctime = fattr->ctime;
767 		else
768 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_CHANGE
769 					| NFS_INO_INVALID_CTIME);
770 	}
771 	if (fattr->valid)
772 		nfs_update_inode(inode, fattr);
773 	spin_unlock(&inode->i_lock);
774 }
775 EXPORT_SYMBOL_GPL(nfs_setattr_update_inode);
776 
777 /*
778  * Don't request help from readdirplus if the file is being written to,
779  * or if attribute caching is turned off
780  */
nfs_getattr_readdirplus_enable(const struct inode * inode)781 static bool nfs_getattr_readdirplus_enable(const struct inode *inode)
782 {
783 	return nfs_server_capable(inode, NFS_CAP_READDIRPLUS) &&
784 	       !nfs_have_writebacks(inode) && NFS_MAXATTRTIMEO(inode) > 5 * HZ;
785 }
786 
nfs_readdirplus_parent_cache_miss(struct dentry * dentry)787 static void nfs_readdirplus_parent_cache_miss(struct dentry *dentry)
788 {
789 	if (!IS_ROOT(dentry)) {
790 		struct dentry *parent = dget_parent(dentry);
791 		nfs_readdir_record_entry_cache_miss(d_inode(parent));
792 		dput(parent);
793 	}
794 }
795 
nfs_readdirplus_parent_cache_hit(struct dentry * dentry)796 static void nfs_readdirplus_parent_cache_hit(struct dentry *dentry)
797 {
798 	if (!IS_ROOT(dentry)) {
799 		struct dentry *parent = dget_parent(dentry);
800 		nfs_readdir_record_entry_cache_hit(d_inode(parent));
801 		dput(parent);
802 	}
803 }
804 
nfs_get_valid_attrmask(struct inode * inode)805 static u32 nfs_get_valid_attrmask(struct inode *inode)
806 {
807 	unsigned long cache_validity = READ_ONCE(NFS_I(inode)->cache_validity);
808 	u32 reply_mask = STATX_INO | STATX_TYPE;
809 
810 	if (!(cache_validity & NFS_INO_INVALID_ATIME))
811 		reply_mask |= STATX_ATIME;
812 	if (!(cache_validity & NFS_INO_INVALID_CTIME))
813 		reply_mask |= STATX_CTIME;
814 	if (!(cache_validity & NFS_INO_INVALID_MTIME))
815 		reply_mask |= STATX_MTIME;
816 	if (!(cache_validity & NFS_INO_INVALID_SIZE))
817 		reply_mask |= STATX_SIZE;
818 	if (!(cache_validity & NFS_INO_INVALID_NLINK))
819 		reply_mask |= STATX_NLINK;
820 	if (!(cache_validity & NFS_INO_INVALID_MODE))
821 		reply_mask |= STATX_MODE;
822 	if (!(cache_validity & NFS_INO_INVALID_OTHER))
823 		reply_mask |= STATX_UID | STATX_GID;
824 	if (!(cache_validity & NFS_INO_INVALID_BLOCKS))
825 		reply_mask |= STATX_BLOCKS;
826 	return reply_mask;
827 }
828 
nfs_getattr(struct user_namespace * mnt_userns,const struct path * path,struct kstat * stat,u32 request_mask,unsigned int query_flags)829 int nfs_getattr(struct user_namespace *mnt_userns, const struct path *path,
830 		struct kstat *stat, u32 request_mask, unsigned int query_flags)
831 {
832 	struct inode *inode = d_inode(path->dentry);
833 	struct nfs_server *server = NFS_SERVER(inode);
834 	unsigned long cache_validity;
835 	int err = 0;
836 	bool force_sync = query_flags & AT_STATX_FORCE_SYNC;
837 	bool do_update = false;
838 	bool readdirplus_enabled = nfs_getattr_readdirplus_enable(inode);
839 
840 	trace_nfs_getattr_enter(inode);
841 
842 	request_mask &= STATX_TYPE | STATX_MODE | STATX_NLINK | STATX_UID |
843 			STATX_GID | STATX_ATIME | STATX_MTIME | STATX_CTIME |
844 			STATX_INO | STATX_SIZE | STATX_BLOCKS;
845 
846 	if ((query_flags & AT_STATX_DONT_SYNC) && !force_sync) {
847 		if (readdirplus_enabled)
848 			nfs_readdirplus_parent_cache_hit(path->dentry);
849 		goto out_no_revalidate;
850 	}
851 
852 	/* Flush out writes to the server in order to update c/mtime.  */
853 	if ((request_mask & (STATX_CTIME | STATX_MTIME)) &&
854 	    S_ISREG(inode->i_mode))
855 		filemap_write_and_wait(inode->i_mapping);
856 
857 	/*
858 	 * We may force a getattr if the user cares about atime.
859 	 *
860 	 * Note that we only have to check the vfsmount flags here:
861 	 *  - NFS always sets S_NOATIME by so checking it would give a
862 	 *    bogus result
863 	 *  - NFS never sets SB_NOATIME or SB_NODIRATIME so there is
864 	 *    no point in checking those.
865 	 */
866 	if ((path->mnt->mnt_flags & MNT_NOATIME) ||
867 	    ((path->mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode)))
868 		request_mask &= ~STATX_ATIME;
869 
870 	/* Is the user requesting attributes that might need revalidation? */
871 	if (!(request_mask & (STATX_MODE|STATX_NLINK|STATX_ATIME|STATX_CTIME|
872 					STATX_MTIME|STATX_UID|STATX_GID|
873 					STATX_SIZE|STATX_BLOCKS)))
874 		goto out_no_revalidate;
875 
876 	/* Check whether the cached attributes are stale */
877 	do_update |= force_sync || nfs_attribute_cache_expired(inode);
878 	cache_validity = READ_ONCE(NFS_I(inode)->cache_validity);
879 	do_update |= cache_validity & NFS_INO_INVALID_CHANGE;
880 	if (request_mask & STATX_ATIME)
881 		do_update |= cache_validity & NFS_INO_INVALID_ATIME;
882 	if (request_mask & STATX_CTIME)
883 		do_update |= cache_validity & NFS_INO_INVALID_CTIME;
884 	if (request_mask & STATX_MTIME)
885 		do_update |= cache_validity & NFS_INO_INVALID_MTIME;
886 	if (request_mask & STATX_SIZE)
887 		do_update |= cache_validity & NFS_INO_INVALID_SIZE;
888 	if (request_mask & STATX_NLINK)
889 		do_update |= cache_validity & NFS_INO_INVALID_NLINK;
890 	if (request_mask & STATX_MODE)
891 		do_update |= cache_validity & NFS_INO_INVALID_MODE;
892 	if (request_mask & (STATX_UID | STATX_GID))
893 		do_update |= cache_validity & NFS_INO_INVALID_OTHER;
894 	if (request_mask & STATX_BLOCKS)
895 		do_update |= cache_validity & NFS_INO_INVALID_BLOCKS;
896 
897 	if (do_update) {
898 		if (readdirplus_enabled)
899 			nfs_readdirplus_parent_cache_miss(path->dentry);
900 		err = __nfs_revalidate_inode(server, inode);
901 		if (err)
902 			goto out;
903 	} else if (readdirplus_enabled)
904 		nfs_readdirplus_parent_cache_hit(path->dentry);
905 out_no_revalidate:
906 	/* Only return attributes that were revalidated. */
907 	stat->result_mask = nfs_get_valid_attrmask(inode) | request_mask;
908 
909 	generic_fillattr(&init_user_ns, inode, stat);
910 	stat->ino = nfs_compat_user_ino64(NFS_FILEID(inode));
911 	if (S_ISDIR(inode->i_mode))
912 		stat->blksize = NFS_SERVER(inode)->dtsize;
913 out:
914 	trace_nfs_getattr_exit(inode, err);
915 	return err;
916 }
917 EXPORT_SYMBOL_GPL(nfs_getattr);
918 
nfs_init_lock_context(struct nfs_lock_context * l_ctx)919 static void nfs_init_lock_context(struct nfs_lock_context *l_ctx)
920 {
921 	refcount_set(&l_ctx->count, 1);
922 	l_ctx->lockowner = current->files;
923 	INIT_LIST_HEAD(&l_ctx->list);
924 	atomic_set(&l_ctx->io_count, 0);
925 }
926 
__nfs_find_lock_context(struct nfs_open_context * ctx)927 static struct nfs_lock_context *__nfs_find_lock_context(struct nfs_open_context *ctx)
928 {
929 	struct nfs_lock_context *pos;
930 
931 	list_for_each_entry_rcu(pos, &ctx->lock_context.list, list) {
932 		if (pos->lockowner != current->files)
933 			continue;
934 		if (refcount_inc_not_zero(&pos->count))
935 			return pos;
936 	}
937 	return NULL;
938 }
939 
nfs_get_lock_context(struct nfs_open_context * ctx)940 struct nfs_lock_context *nfs_get_lock_context(struct nfs_open_context *ctx)
941 {
942 	struct nfs_lock_context *res, *new = NULL;
943 	struct inode *inode = d_inode(ctx->dentry);
944 
945 	rcu_read_lock();
946 	res = __nfs_find_lock_context(ctx);
947 	rcu_read_unlock();
948 	if (res == NULL) {
949 		new = kmalloc(sizeof(*new), GFP_KERNEL_ACCOUNT);
950 		if (new == NULL)
951 			return ERR_PTR(-ENOMEM);
952 		nfs_init_lock_context(new);
953 		spin_lock(&inode->i_lock);
954 		res = __nfs_find_lock_context(ctx);
955 		if (res == NULL) {
956 			new->open_context = get_nfs_open_context(ctx);
957 			if (new->open_context) {
958 				list_add_tail_rcu(&new->list,
959 						&ctx->lock_context.list);
960 				res = new;
961 				new = NULL;
962 			} else
963 				res = ERR_PTR(-EBADF);
964 		}
965 		spin_unlock(&inode->i_lock);
966 		kfree(new);
967 	}
968 	return res;
969 }
970 EXPORT_SYMBOL_GPL(nfs_get_lock_context);
971 
nfs_put_lock_context(struct nfs_lock_context * l_ctx)972 void nfs_put_lock_context(struct nfs_lock_context *l_ctx)
973 {
974 	struct nfs_open_context *ctx = l_ctx->open_context;
975 	struct inode *inode = d_inode(ctx->dentry);
976 
977 	if (!refcount_dec_and_lock(&l_ctx->count, &inode->i_lock))
978 		return;
979 	list_del_rcu(&l_ctx->list);
980 	spin_unlock(&inode->i_lock);
981 	put_nfs_open_context(ctx);
982 	kfree_rcu(l_ctx, rcu_head);
983 }
984 EXPORT_SYMBOL_GPL(nfs_put_lock_context);
985 
986 /**
987  * nfs_close_context - Common close_context() routine NFSv2/v3
988  * @ctx: pointer to context
989  * @is_sync: is this a synchronous close
990  *
991  * Ensure that the attributes are up to date if we're mounted
992  * with close-to-open semantics and we have cached data that will
993  * need to be revalidated on open.
994  */
nfs_close_context(struct nfs_open_context * ctx,int is_sync)995 void nfs_close_context(struct nfs_open_context *ctx, int is_sync)
996 {
997 	struct nfs_inode *nfsi;
998 	struct inode *inode;
999 
1000 	if (!(ctx->mode & FMODE_WRITE))
1001 		return;
1002 	if (!is_sync)
1003 		return;
1004 	inode = d_inode(ctx->dentry);
1005 	if (NFS_PROTO(inode)->have_delegation(inode, FMODE_READ))
1006 		return;
1007 	nfsi = NFS_I(inode);
1008 	if (inode->i_mapping->nrpages == 0)
1009 		return;
1010 	if (nfsi->cache_validity & NFS_INO_INVALID_DATA)
1011 		return;
1012 	if (!list_empty(&nfsi->open_files))
1013 		return;
1014 	if (NFS_SERVER(inode)->flags & NFS_MOUNT_NOCTO)
1015 		return;
1016 	nfs_revalidate_inode(inode,
1017 			     NFS_INO_INVALID_CHANGE | NFS_INO_INVALID_SIZE);
1018 }
1019 EXPORT_SYMBOL_GPL(nfs_close_context);
1020 
alloc_nfs_open_context(struct dentry * dentry,fmode_t f_mode,struct file * filp)1021 struct nfs_open_context *alloc_nfs_open_context(struct dentry *dentry,
1022 						fmode_t f_mode,
1023 						struct file *filp)
1024 {
1025 	struct nfs_open_context *ctx;
1026 
1027 	ctx = kmalloc(sizeof(*ctx), GFP_KERNEL_ACCOUNT);
1028 	if (!ctx)
1029 		return ERR_PTR(-ENOMEM);
1030 	nfs_sb_active(dentry->d_sb);
1031 	ctx->dentry = dget(dentry);
1032 	if (filp)
1033 		ctx->cred = get_cred(filp->f_cred);
1034 	else
1035 		ctx->cred = get_current_cred();
1036 	rcu_assign_pointer(ctx->ll_cred, NULL);
1037 	ctx->state = NULL;
1038 	ctx->mode = f_mode;
1039 	ctx->flags = 0;
1040 	ctx->error = 0;
1041 	ctx->flock_owner = (fl_owner_t)filp;
1042 	nfs_init_lock_context(&ctx->lock_context);
1043 	ctx->lock_context.open_context = ctx;
1044 	INIT_LIST_HEAD(&ctx->list);
1045 	ctx->mdsthreshold = NULL;
1046 	return ctx;
1047 }
1048 EXPORT_SYMBOL_GPL(alloc_nfs_open_context);
1049 
get_nfs_open_context(struct nfs_open_context * ctx)1050 struct nfs_open_context *get_nfs_open_context(struct nfs_open_context *ctx)
1051 {
1052 	if (ctx != NULL && refcount_inc_not_zero(&ctx->lock_context.count))
1053 		return ctx;
1054 	return NULL;
1055 }
1056 EXPORT_SYMBOL_GPL(get_nfs_open_context);
1057 
__put_nfs_open_context(struct nfs_open_context * ctx,int is_sync)1058 static void __put_nfs_open_context(struct nfs_open_context *ctx, int is_sync)
1059 {
1060 	struct inode *inode = d_inode(ctx->dentry);
1061 	struct super_block *sb = ctx->dentry->d_sb;
1062 
1063 	if (!refcount_dec_and_test(&ctx->lock_context.count))
1064 		return;
1065 	if (!list_empty(&ctx->list)) {
1066 		spin_lock(&inode->i_lock);
1067 		list_del_rcu(&ctx->list);
1068 		spin_unlock(&inode->i_lock);
1069 	}
1070 	if (inode != NULL)
1071 		NFS_PROTO(inode)->close_context(ctx, is_sync);
1072 	put_cred(ctx->cred);
1073 	dput(ctx->dentry);
1074 	nfs_sb_deactive(sb);
1075 	put_rpccred(rcu_dereference_protected(ctx->ll_cred, 1));
1076 	kfree(ctx->mdsthreshold);
1077 	kfree_rcu(ctx, rcu_head);
1078 }
1079 
put_nfs_open_context(struct nfs_open_context * ctx)1080 void put_nfs_open_context(struct nfs_open_context *ctx)
1081 {
1082 	__put_nfs_open_context(ctx, 0);
1083 }
1084 EXPORT_SYMBOL_GPL(put_nfs_open_context);
1085 
put_nfs_open_context_sync(struct nfs_open_context * ctx)1086 static void put_nfs_open_context_sync(struct nfs_open_context *ctx)
1087 {
1088 	__put_nfs_open_context(ctx, 1);
1089 }
1090 
1091 /*
1092  * Ensure that mmap has a recent RPC credential for use when writing out
1093  * shared pages
1094  */
nfs_inode_attach_open_context(struct nfs_open_context * ctx)1095 void nfs_inode_attach_open_context(struct nfs_open_context *ctx)
1096 {
1097 	struct inode *inode = d_inode(ctx->dentry);
1098 	struct nfs_inode *nfsi = NFS_I(inode);
1099 
1100 	spin_lock(&inode->i_lock);
1101 	if (list_empty(&nfsi->open_files) &&
1102 	    (nfsi->cache_validity & NFS_INO_DATA_INVAL_DEFER))
1103 		nfs_set_cache_invalid(inode, NFS_INO_INVALID_DATA |
1104 						     NFS_INO_REVAL_FORCED);
1105 	list_add_tail_rcu(&ctx->list, &nfsi->open_files);
1106 	spin_unlock(&inode->i_lock);
1107 }
1108 EXPORT_SYMBOL_GPL(nfs_inode_attach_open_context);
1109 
nfs_file_set_open_context(struct file * filp,struct nfs_open_context * ctx)1110 void nfs_file_set_open_context(struct file *filp, struct nfs_open_context *ctx)
1111 {
1112 	filp->private_data = get_nfs_open_context(ctx);
1113 	set_bit(NFS_CONTEXT_FILE_OPEN, &ctx->flags);
1114 	if (list_empty(&ctx->list))
1115 		nfs_inode_attach_open_context(ctx);
1116 }
1117 EXPORT_SYMBOL_GPL(nfs_file_set_open_context);
1118 
1119 /*
1120  * Given an inode, search for an open context with the desired characteristics
1121  */
nfs_find_open_context(struct inode * inode,const struct cred * cred,fmode_t mode)1122 struct nfs_open_context *nfs_find_open_context(struct inode *inode, const struct cred *cred, fmode_t mode)
1123 {
1124 	struct nfs_inode *nfsi = NFS_I(inode);
1125 	struct nfs_open_context *pos, *ctx = NULL;
1126 
1127 	rcu_read_lock();
1128 	list_for_each_entry_rcu(pos, &nfsi->open_files, list) {
1129 		if (cred != NULL && cred_fscmp(pos->cred, cred) != 0)
1130 			continue;
1131 		if ((pos->mode & (FMODE_READ|FMODE_WRITE)) != mode)
1132 			continue;
1133 		if (!test_bit(NFS_CONTEXT_FILE_OPEN, &pos->flags))
1134 			continue;
1135 		ctx = get_nfs_open_context(pos);
1136 		if (ctx)
1137 			break;
1138 	}
1139 	rcu_read_unlock();
1140 	return ctx;
1141 }
1142 
nfs_file_clear_open_context(struct file * filp)1143 void nfs_file_clear_open_context(struct file *filp)
1144 {
1145 	struct nfs_open_context *ctx = nfs_file_open_context(filp);
1146 
1147 	if (ctx) {
1148 		struct inode *inode = d_inode(ctx->dentry);
1149 
1150 		clear_bit(NFS_CONTEXT_FILE_OPEN, &ctx->flags);
1151 		/*
1152 		 * We fatal error on write before. Try to writeback
1153 		 * every page again.
1154 		 */
1155 		if (ctx->error < 0)
1156 			invalidate_inode_pages2(inode->i_mapping);
1157 		filp->private_data = NULL;
1158 		put_nfs_open_context_sync(ctx);
1159 	}
1160 }
1161 
1162 /*
1163  * These allocate and release file read/write context information.
1164  */
nfs_open(struct inode * inode,struct file * filp)1165 int nfs_open(struct inode *inode, struct file *filp)
1166 {
1167 	struct nfs_open_context *ctx;
1168 
1169 	ctx = alloc_nfs_open_context(file_dentry(filp), filp->f_mode, filp);
1170 	if (IS_ERR(ctx))
1171 		return PTR_ERR(ctx);
1172 	nfs_file_set_open_context(filp, ctx);
1173 	put_nfs_open_context(ctx);
1174 	nfs_fscache_open_file(inode, filp);
1175 	return 0;
1176 }
1177 
1178 /*
1179  * This function is called whenever some part of NFS notices that
1180  * the cached attributes have to be refreshed.
1181  */
1182 int
__nfs_revalidate_inode(struct nfs_server * server,struct inode * inode)1183 __nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
1184 {
1185 	int		 status = -ESTALE;
1186 	struct nfs_fattr *fattr = NULL;
1187 	struct nfs_inode *nfsi = NFS_I(inode);
1188 
1189 	dfprintk(PAGECACHE, "NFS: revalidating (%s/%Lu)\n",
1190 		inode->i_sb->s_id, (unsigned long long)NFS_FILEID(inode));
1191 
1192 	trace_nfs_revalidate_inode_enter(inode);
1193 
1194 	if (is_bad_inode(inode))
1195 		goto out;
1196 	if (NFS_STALE(inode))
1197 		goto out;
1198 
1199 	/* pNFS: Attributes aren't updated until we layoutcommit */
1200 	if (S_ISREG(inode->i_mode)) {
1201 		status = pnfs_sync_inode(inode, false);
1202 		if (status)
1203 			goto out;
1204 	}
1205 
1206 	status = -ENOMEM;
1207 	fattr = nfs_alloc_fattr_with_label(NFS_SERVER(inode));
1208 	if (fattr == NULL)
1209 		goto out;
1210 
1211 	nfs_inc_stats(inode, NFSIOS_INODEREVALIDATE);
1212 
1213 	status = NFS_PROTO(inode)->getattr(server, NFS_FH(inode), fattr, inode);
1214 	if (status != 0) {
1215 		dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Lu) getattr failed, error=%d\n",
1216 			 inode->i_sb->s_id,
1217 			 (unsigned long long)NFS_FILEID(inode), status);
1218 		switch (status) {
1219 		case -ETIMEDOUT:
1220 			/* A soft timeout occurred. Use cached information? */
1221 			if (server->flags & NFS_MOUNT_SOFTREVAL)
1222 				status = 0;
1223 			break;
1224 		case -ESTALE:
1225 			if (!S_ISDIR(inode->i_mode))
1226 				nfs_set_inode_stale(inode);
1227 			else
1228 				nfs_zap_caches(inode);
1229 		}
1230 		goto out;
1231 	}
1232 
1233 	status = nfs_refresh_inode(inode, fattr);
1234 	if (status) {
1235 		dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Lu) refresh failed, error=%d\n",
1236 			 inode->i_sb->s_id,
1237 			 (unsigned long long)NFS_FILEID(inode), status);
1238 		goto out;
1239 	}
1240 
1241 	if (nfsi->cache_validity & NFS_INO_INVALID_ACL)
1242 		nfs_zap_acl_cache(inode);
1243 
1244 	nfs_setsecurity(inode, fattr);
1245 
1246 	dfprintk(PAGECACHE, "NFS: (%s/%Lu) revalidation complete\n",
1247 		inode->i_sb->s_id,
1248 		(unsigned long long)NFS_FILEID(inode));
1249 
1250 out:
1251 	nfs_free_fattr(fattr);
1252 	trace_nfs_revalidate_inode_exit(inode, status);
1253 	return status;
1254 }
1255 
nfs_attribute_cache_expired(struct inode * inode)1256 int nfs_attribute_cache_expired(struct inode *inode)
1257 {
1258 	if (nfs_have_delegated_attributes(inode))
1259 		return 0;
1260 	return nfs_attribute_timeout(inode);
1261 }
1262 
1263 /**
1264  * nfs_revalidate_inode - Revalidate the inode attributes
1265  * @inode: pointer to inode struct
1266  * @flags: cache flags to check
1267  *
1268  * Updates inode attribute information by retrieving the data from the server.
1269  */
nfs_revalidate_inode(struct inode * inode,unsigned long flags)1270 int nfs_revalidate_inode(struct inode *inode, unsigned long flags)
1271 {
1272 	if (!nfs_check_cache_invalid(inode, flags))
1273 		return NFS_STALE(inode) ? -ESTALE : 0;
1274 	return __nfs_revalidate_inode(NFS_SERVER(inode), inode);
1275 }
1276 EXPORT_SYMBOL_GPL(nfs_revalidate_inode);
1277 
nfs_invalidate_mapping(struct inode * inode,struct address_space * mapping)1278 static int nfs_invalidate_mapping(struct inode *inode, struct address_space *mapping)
1279 {
1280 	int ret;
1281 
1282 	nfs_fscache_invalidate(inode, 0);
1283 	if (mapping->nrpages != 0) {
1284 		if (S_ISREG(inode->i_mode)) {
1285 			ret = nfs_sync_mapping(mapping);
1286 			if (ret < 0)
1287 				return ret;
1288 		}
1289 		ret = invalidate_inode_pages2(mapping);
1290 		if (ret < 0)
1291 			return ret;
1292 	}
1293 	nfs_inc_stats(inode, NFSIOS_DATAINVALIDATE);
1294 
1295 	dfprintk(PAGECACHE, "NFS: (%s/%Lu) data cache invalidated\n",
1296 			inode->i_sb->s_id,
1297 			(unsigned long long)NFS_FILEID(inode));
1298 	return 0;
1299 }
1300 
1301 /**
1302  * nfs_clear_invalid_mapping - Conditionally clear a mapping
1303  * @mapping: pointer to mapping
1304  *
1305  * If the NFS_INO_INVALID_DATA inode flag is set, clear the mapping.
1306  */
nfs_clear_invalid_mapping(struct address_space * mapping)1307 int nfs_clear_invalid_mapping(struct address_space *mapping)
1308 {
1309 	struct inode *inode = mapping->host;
1310 	struct nfs_inode *nfsi = NFS_I(inode);
1311 	unsigned long *bitlock = &nfsi->flags;
1312 	int ret = 0;
1313 
1314 	/*
1315 	 * We must clear NFS_INO_INVALID_DATA first to ensure that
1316 	 * invalidations that come in while we're shooting down the mappings
1317 	 * are respected. But, that leaves a race window where one revalidator
1318 	 * can clear the flag, and then another checks it before the mapping
1319 	 * gets invalidated. Fix that by serializing access to this part of
1320 	 * the function.
1321 	 *
1322 	 * At the same time, we need to allow other tasks to see whether we
1323 	 * might be in the middle of invalidating the pages, so we only set
1324 	 * the bit lock here if it looks like we're going to be doing that.
1325 	 */
1326 	for (;;) {
1327 		ret = wait_on_bit_action(bitlock, NFS_INO_INVALIDATING,
1328 					 nfs_wait_bit_killable,
1329 					 TASK_KILLABLE|TASK_FREEZABLE_UNSAFE);
1330 		if (ret)
1331 			goto out;
1332 		spin_lock(&inode->i_lock);
1333 		if (test_bit(NFS_INO_INVALIDATING, bitlock)) {
1334 			spin_unlock(&inode->i_lock);
1335 			continue;
1336 		}
1337 		if (nfsi->cache_validity & NFS_INO_INVALID_DATA)
1338 			break;
1339 		spin_unlock(&inode->i_lock);
1340 		goto out;
1341 	}
1342 
1343 	set_bit(NFS_INO_INVALIDATING, bitlock);
1344 	smp_wmb();
1345 	nfsi->cache_validity &=
1346 		~(NFS_INO_INVALID_DATA | NFS_INO_DATA_INVAL_DEFER);
1347 	spin_unlock(&inode->i_lock);
1348 	trace_nfs_invalidate_mapping_enter(inode);
1349 	ret = nfs_invalidate_mapping(inode, mapping);
1350 	trace_nfs_invalidate_mapping_exit(inode, ret);
1351 
1352 	clear_bit_unlock(NFS_INO_INVALIDATING, bitlock);
1353 	smp_mb__after_atomic();
1354 	wake_up_bit(bitlock, NFS_INO_INVALIDATING);
1355 out:
1356 	return ret;
1357 }
1358 
nfs_mapping_need_revalidate_inode(struct inode * inode)1359 bool nfs_mapping_need_revalidate_inode(struct inode *inode)
1360 {
1361 	return nfs_check_cache_invalid(inode, NFS_INO_INVALID_CHANGE) ||
1362 		NFS_STALE(inode);
1363 }
1364 
nfs_revalidate_mapping_rcu(struct inode * inode)1365 int nfs_revalidate_mapping_rcu(struct inode *inode)
1366 {
1367 	struct nfs_inode *nfsi = NFS_I(inode);
1368 	unsigned long *bitlock = &nfsi->flags;
1369 	int ret = 0;
1370 
1371 	if (IS_SWAPFILE(inode))
1372 		goto out;
1373 	if (nfs_mapping_need_revalidate_inode(inode)) {
1374 		ret = -ECHILD;
1375 		goto out;
1376 	}
1377 	spin_lock(&inode->i_lock);
1378 	if (test_bit(NFS_INO_INVALIDATING, bitlock) ||
1379 	    (nfsi->cache_validity & NFS_INO_INVALID_DATA))
1380 		ret = -ECHILD;
1381 	spin_unlock(&inode->i_lock);
1382 out:
1383 	return ret;
1384 }
1385 
1386 /**
1387  * nfs_revalidate_mapping - Revalidate the pagecache
1388  * @inode: pointer to host inode
1389  * @mapping: pointer to mapping
1390  */
nfs_revalidate_mapping(struct inode * inode,struct address_space * mapping)1391 int nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping)
1392 {
1393 	/* swapfiles are not supposed to be shared. */
1394 	if (IS_SWAPFILE(inode))
1395 		return 0;
1396 
1397 	if (nfs_mapping_need_revalidate_inode(inode)) {
1398 		int ret = __nfs_revalidate_inode(NFS_SERVER(inode), inode);
1399 		if (ret < 0)
1400 			return ret;
1401 	}
1402 
1403 	return nfs_clear_invalid_mapping(mapping);
1404 }
1405 
nfs_file_has_writers(struct nfs_inode * nfsi)1406 static bool nfs_file_has_writers(struct nfs_inode *nfsi)
1407 {
1408 	struct inode *inode = &nfsi->vfs_inode;
1409 
1410 	if (!S_ISREG(inode->i_mode))
1411 		return false;
1412 	if (list_empty(&nfsi->open_files))
1413 		return false;
1414 	return inode_is_open_for_write(inode);
1415 }
1416 
nfs_file_has_buffered_writers(struct nfs_inode * nfsi)1417 static bool nfs_file_has_buffered_writers(struct nfs_inode *nfsi)
1418 {
1419 	return nfs_file_has_writers(nfsi) && nfs_file_io_is_buffered(nfsi);
1420 }
1421 
nfs_wcc_update_inode(struct inode * inode,struct nfs_fattr * fattr)1422 static void nfs_wcc_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1423 {
1424 	struct timespec64 ts;
1425 
1426 	if ((fattr->valid & NFS_ATTR_FATTR_PRECHANGE)
1427 			&& (fattr->valid & NFS_ATTR_FATTR_CHANGE)
1428 			&& inode_eq_iversion_raw(inode, fattr->pre_change_attr)) {
1429 		inode_set_iversion_raw(inode, fattr->change_attr);
1430 		if (S_ISDIR(inode->i_mode))
1431 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_DATA);
1432 		else if (nfs_server_capable(inode, NFS_CAP_XATTR))
1433 			nfs_set_cache_invalid(inode, NFS_INO_INVALID_XATTR);
1434 	}
1435 	/* If we have atomic WCC data, we may update some attributes */
1436 	ts = inode->i_ctime;
1437 	if ((fattr->valid & NFS_ATTR_FATTR_PRECTIME)
1438 			&& (fattr->valid & NFS_ATTR_FATTR_CTIME)
1439 			&& timespec64_equal(&ts, &fattr->pre_ctime)) {
1440 		inode->i_ctime = fattr->ctime;
1441 	}
1442 
1443 	ts = inode->i_mtime;
1444 	if ((fattr->valid & NFS_ATTR_FATTR_PREMTIME)
1445 			&& (fattr->valid & NFS_ATTR_FATTR_MTIME)
1446 			&& timespec64_equal(&ts, &fattr->pre_mtime)) {
1447 		inode->i_mtime = fattr->mtime;
1448 	}
1449 	if ((fattr->valid & NFS_ATTR_FATTR_PRESIZE)
1450 			&& (fattr->valid & NFS_ATTR_FATTR_SIZE)
1451 			&& i_size_read(inode) == nfs_size_to_loff_t(fattr->pre_size)
1452 			&& !nfs_have_writebacks(inode)) {
1453 		trace_nfs_size_wcc(inode, fattr->size);
1454 		i_size_write(inode, nfs_size_to_loff_t(fattr->size));
1455 	}
1456 }
1457 
1458 /**
1459  * nfs_check_inode_attributes - verify consistency of the inode attribute cache
1460  * @inode: pointer to inode
1461  * @fattr: updated attributes
1462  *
1463  * Verifies the attribute cache. If we have just changed the attributes,
1464  * so that fattr carries weak cache consistency data, then it may
1465  * also update the ctime/mtime/change_attribute.
1466  */
nfs_check_inode_attributes(struct inode * inode,struct nfs_fattr * fattr)1467 static int nfs_check_inode_attributes(struct inode *inode, struct nfs_fattr *fattr)
1468 {
1469 	struct nfs_inode *nfsi = NFS_I(inode);
1470 	loff_t cur_size, new_isize;
1471 	unsigned long invalid = 0;
1472 	struct timespec64 ts;
1473 
1474 	if (NFS_PROTO(inode)->have_delegation(inode, FMODE_READ))
1475 		return 0;
1476 
1477 	if (!(fattr->valid & NFS_ATTR_FATTR_FILEID)) {
1478 		/* Only a mounted-on-fileid? Just exit */
1479 		if (fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID)
1480 			return 0;
1481 	/* Has the inode gone and changed behind our back? */
1482 	} else if (nfsi->fileid != fattr->fileid) {
1483 		/* Is this perhaps the mounted-on fileid? */
1484 		if ((fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID) &&
1485 		    nfsi->fileid == fattr->mounted_on_fileid)
1486 			return 0;
1487 		return -ESTALE;
1488 	}
1489 	if ((fattr->valid & NFS_ATTR_FATTR_TYPE) && inode_wrong_type(inode, fattr->mode))
1490 		return -ESTALE;
1491 
1492 
1493 	if (!nfs_file_has_buffered_writers(nfsi)) {
1494 		/* Verify a few of the more important attributes */
1495 		if ((fattr->valid & NFS_ATTR_FATTR_CHANGE) != 0 && !inode_eq_iversion_raw(inode, fattr->change_attr))
1496 			invalid |= NFS_INO_INVALID_CHANGE;
1497 
1498 		ts = inode->i_mtime;
1499 		if ((fattr->valid & NFS_ATTR_FATTR_MTIME) && !timespec64_equal(&ts, &fattr->mtime))
1500 			invalid |= NFS_INO_INVALID_MTIME;
1501 
1502 		ts = inode->i_ctime;
1503 		if ((fattr->valid & NFS_ATTR_FATTR_CTIME) && !timespec64_equal(&ts, &fattr->ctime))
1504 			invalid |= NFS_INO_INVALID_CTIME;
1505 
1506 		if (fattr->valid & NFS_ATTR_FATTR_SIZE) {
1507 			cur_size = i_size_read(inode);
1508 			new_isize = nfs_size_to_loff_t(fattr->size);
1509 			if (cur_size != new_isize)
1510 				invalid |= NFS_INO_INVALID_SIZE;
1511 		}
1512 	}
1513 
1514 	/* Have any file permissions changed? */
1515 	if ((fattr->valid & NFS_ATTR_FATTR_MODE) && (inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO))
1516 		invalid |= NFS_INO_INVALID_MODE;
1517 	if ((fattr->valid & NFS_ATTR_FATTR_OWNER) && !uid_eq(inode->i_uid, fattr->uid))
1518 		invalid |= NFS_INO_INVALID_OTHER;
1519 	if ((fattr->valid & NFS_ATTR_FATTR_GROUP) && !gid_eq(inode->i_gid, fattr->gid))
1520 		invalid |= NFS_INO_INVALID_OTHER;
1521 
1522 	/* Has the link count changed? */
1523 	if ((fattr->valid & NFS_ATTR_FATTR_NLINK) && inode->i_nlink != fattr->nlink)
1524 		invalid |= NFS_INO_INVALID_NLINK;
1525 
1526 	ts = inode->i_atime;
1527 	if ((fattr->valid & NFS_ATTR_FATTR_ATIME) && !timespec64_equal(&ts, &fattr->atime))
1528 		invalid |= NFS_INO_INVALID_ATIME;
1529 
1530 	if (invalid != 0)
1531 		nfs_set_cache_invalid(inode, invalid);
1532 
1533 	nfsi->read_cache_jiffies = fattr->time_start;
1534 	return 0;
1535 }
1536 
1537 static atomic_long_t nfs_attr_generation_counter;
1538 
nfs_read_attr_generation_counter(void)1539 static unsigned long nfs_read_attr_generation_counter(void)
1540 {
1541 	return atomic_long_read(&nfs_attr_generation_counter);
1542 }
1543 
nfs_inc_attr_generation_counter(void)1544 unsigned long nfs_inc_attr_generation_counter(void)
1545 {
1546 	return atomic_long_inc_return(&nfs_attr_generation_counter);
1547 }
1548 EXPORT_SYMBOL_GPL(nfs_inc_attr_generation_counter);
1549 
nfs_fattr_init(struct nfs_fattr * fattr)1550 void nfs_fattr_init(struct nfs_fattr *fattr)
1551 {
1552 	fattr->valid = 0;
1553 	fattr->time_start = jiffies;
1554 	fattr->gencount = nfs_inc_attr_generation_counter();
1555 	fattr->owner_name = NULL;
1556 	fattr->group_name = NULL;
1557 }
1558 EXPORT_SYMBOL_GPL(nfs_fattr_init);
1559 
1560 /**
1561  * nfs_fattr_set_barrier
1562  * @fattr: attributes
1563  *
1564  * Used to set a barrier after an attribute was updated. This
1565  * barrier ensures that older attributes from RPC calls that may
1566  * have raced with our update cannot clobber these new values.
1567  * Note that you are still responsible for ensuring that other
1568  * operations which change the attribute on the server do not
1569  * collide.
1570  */
nfs_fattr_set_barrier(struct nfs_fattr * fattr)1571 void nfs_fattr_set_barrier(struct nfs_fattr *fattr)
1572 {
1573 	fattr->gencount = nfs_inc_attr_generation_counter();
1574 }
1575 
nfs_alloc_fattr(void)1576 struct nfs_fattr *nfs_alloc_fattr(void)
1577 {
1578 	struct nfs_fattr *fattr;
1579 
1580 	fattr = kmalloc(sizeof(*fattr), GFP_KERNEL);
1581 	if (fattr != NULL) {
1582 		nfs_fattr_init(fattr);
1583 		fattr->label = NULL;
1584 	}
1585 	return fattr;
1586 }
1587 EXPORT_SYMBOL_GPL(nfs_alloc_fattr);
1588 
nfs_alloc_fattr_with_label(struct nfs_server * server)1589 struct nfs_fattr *nfs_alloc_fattr_with_label(struct nfs_server *server)
1590 {
1591 	struct nfs_fattr *fattr = nfs_alloc_fattr();
1592 
1593 	if (!fattr)
1594 		return NULL;
1595 
1596 	fattr->label = nfs4_label_alloc(server, GFP_KERNEL);
1597 	if (IS_ERR(fattr->label)) {
1598 		kfree(fattr);
1599 		return NULL;
1600 	}
1601 
1602 	return fattr;
1603 }
1604 EXPORT_SYMBOL_GPL(nfs_alloc_fattr_with_label);
1605 
nfs_alloc_fhandle(void)1606 struct nfs_fh *nfs_alloc_fhandle(void)
1607 {
1608 	struct nfs_fh *fh;
1609 
1610 	fh = kmalloc(sizeof(struct nfs_fh), GFP_KERNEL);
1611 	if (fh != NULL)
1612 		fh->size = 0;
1613 	return fh;
1614 }
1615 EXPORT_SYMBOL_GPL(nfs_alloc_fhandle);
1616 
1617 #ifdef NFS_DEBUG
1618 /*
1619  * _nfs_display_fhandle_hash - calculate the crc32 hash for the filehandle
1620  *                             in the same way that wireshark does
1621  *
1622  * @fh: file handle
1623  *
1624  * For debugging only.
1625  */
_nfs_display_fhandle_hash(const struct nfs_fh * fh)1626 u32 _nfs_display_fhandle_hash(const struct nfs_fh *fh)
1627 {
1628 	/* wireshark uses 32-bit AUTODIN crc and does a bitwise
1629 	 * not on the result */
1630 	return nfs_fhandle_hash(fh);
1631 }
1632 EXPORT_SYMBOL_GPL(_nfs_display_fhandle_hash);
1633 
1634 /*
1635  * _nfs_display_fhandle - display an NFS file handle on the console
1636  *
1637  * @fh: file handle to display
1638  * @caption: display caption
1639  *
1640  * For debugging only.
1641  */
_nfs_display_fhandle(const struct nfs_fh * fh,const char * caption)1642 void _nfs_display_fhandle(const struct nfs_fh *fh, const char *caption)
1643 {
1644 	unsigned short i;
1645 
1646 	if (fh == NULL || fh->size == 0) {
1647 		printk(KERN_DEFAULT "%s at %p is empty\n", caption, fh);
1648 		return;
1649 	}
1650 
1651 	printk(KERN_DEFAULT "%s at %p is %u bytes, crc: 0x%08x:\n",
1652 	       caption, fh, fh->size, _nfs_display_fhandle_hash(fh));
1653 	for (i = 0; i < fh->size; i += 16) {
1654 		__be32 *pos = (__be32 *)&fh->data[i];
1655 
1656 		switch ((fh->size - i - 1) >> 2) {
1657 		case 0:
1658 			printk(KERN_DEFAULT " %08x\n",
1659 				be32_to_cpup(pos));
1660 			break;
1661 		case 1:
1662 			printk(KERN_DEFAULT " %08x %08x\n",
1663 				be32_to_cpup(pos), be32_to_cpup(pos + 1));
1664 			break;
1665 		case 2:
1666 			printk(KERN_DEFAULT " %08x %08x %08x\n",
1667 				be32_to_cpup(pos), be32_to_cpup(pos + 1),
1668 				be32_to_cpup(pos + 2));
1669 			break;
1670 		default:
1671 			printk(KERN_DEFAULT " %08x %08x %08x %08x\n",
1672 				be32_to_cpup(pos), be32_to_cpup(pos + 1),
1673 				be32_to_cpup(pos + 2), be32_to_cpup(pos + 3));
1674 		}
1675 	}
1676 }
1677 EXPORT_SYMBOL_GPL(_nfs_display_fhandle);
1678 #endif
1679 
1680 /**
1681  * nfs_inode_attrs_cmp_generic - compare attributes
1682  * @fattr: attributes
1683  * @inode: pointer to inode
1684  *
1685  * Attempt to divine whether or not an RPC call reply carrying stale
1686  * attributes got scheduled after another call carrying updated ones.
1687  * Note also the check for wraparound of 'attr_gencount'
1688  *
1689  * The function returns '1' if it thinks the attributes in @fattr are
1690  * more recent than the ones cached in @inode. Otherwise it returns
1691  * the value '0'.
1692  */
nfs_inode_attrs_cmp_generic(const struct nfs_fattr * fattr,const struct inode * inode)1693 static int nfs_inode_attrs_cmp_generic(const struct nfs_fattr *fattr,
1694 				       const struct inode *inode)
1695 {
1696 	unsigned long attr_gencount = NFS_I(inode)->attr_gencount;
1697 
1698 	return (long)(fattr->gencount - attr_gencount) > 0 ||
1699 	       (long)(attr_gencount - nfs_read_attr_generation_counter()) > 0;
1700 }
1701 
1702 /**
1703  * nfs_inode_attrs_cmp_monotonic - compare attributes
1704  * @fattr: attributes
1705  * @inode: pointer to inode
1706  *
1707  * Attempt to divine whether or not an RPC call reply carrying stale
1708  * attributes got scheduled after another call carrying updated ones.
1709  *
1710  * We assume that the server observes monotonic semantics for
1711  * the change attribute, so a larger value means that the attributes in
1712  * @fattr are more recent, in which case the function returns the
1713  * value '1'.
1714  * A return value of '0' indicates no measurable change
1715  * A return value of '-1' means that the attributes in @inode are
1716  * more recent.
1717  */
nfs_inode_attrs_cmp_monotonic(const struct nfs_fattr * fattr,const struct inode * inode)1718 static int nfs_inode_attrs_cmp_monotonic(const struct nfs_fattr *fattr,
1719 					 const struct inode *inode)
1720 {
1721 	s64 diff = fattr->change_attr - inode_peek_iversion_raw(inode);
1722 	if (diff > 0)
1723 		return 1;
1724 	return diff == 0 ? 0 : -1;
1725 }
1726 
1727 /**
1728  * nfs_inode_attrs_cmp_strict_monotonic - compare attributes
1729  * @fattr: attributes
1730  * @inode: pointer to inode
1731  *
1732  * Attempt to divine whether or not an RPC call reply carrying stale
1733  * attributes got scheduled after another call carrying updated ones.
1734  *
1735  * We assume that the server observes strictly monotonic semantics for
1736  * the change attribute, so a larger value means that the attributes in
1737  * @fattr are more recent, in which case the function returns the
1738  * value '1'.
1739  * A return value of '-1' means that the attributes in @inode are
1740  * more recent or unchanged.
1741  */
nfs_inode_attrs_cmp_strict_monotonic(const struct nfs_fattr * fattr,const struct inode * inode)1742 static int nfs_inode_attrs_cmp_strict_monotonic(const struct nfs_fattr *fattr,
1743 						const struct inode *inode)
1744 {
1745 	return  nfs_inode_attrs_cmp_monotonic(fattr, inode) > 0 ? 1 : -1;
1746 }
1747 
1748 /**
1749  * nfs_inode_attrs_cmp - compare attributes
1750  * @fattr: attributes
1751  * @inode: pointer to inode
1752  *
1753  * This function returns '1' if it thinks the attributes in @fattr are
1754  * more recent than the ones cached in @inode. It returns '-1' if
1755  * the attributes in @inode are more recent than the ones in @fattr,
1756  * and it returns 0 if not sure.
1757  */
nfs_inode_attrs_cmp(const struct nfs_fattr * fattr,const struct inode * inode)1758 static int nfs_inode_attrs_cmp(const struct nfs_fattr *fattr,
1759 			       const struct inode *inode)
1760 {
1761 	if (nfs_inode_attrs_cmp_generic(fattr, inode) > 0)
1762 		return 1;
1763 	switch (NFS_SERVER(inode)->change_attr_type) {
1764 	case NFS4_CHANGE_TYPE_IS_UNDEFINED:
1765 		break;
1766 	case NFS4_CHANGE_TYPE_IS_TIME_METADATA:
1767 		if (!(fattr->valid & NFS_ATTR_FATTR_CHANGE))
1768 			break;
1769 		return nfs_inode_attrs_cmp_monotonic(fattr, inode);
1770 	default:
1771 		if (!(fattr->valid & NFS_ATTR_FATTR_CHANGE))
1772 			break;
1773 		return nfs_inode_attrs_cmp_strict_monotonic(fattr, inode);
1774 	}
1775 	return 0;
1776 }
1777 
1778 /**
1779  * nfs_inode_finish_partial_attr_update - complete a previous inode update
1780  * @fattr: attributes
1781  * @inode: pointer to inode
1782  *
1783  * Returns '1' if the last attribute update left the inode cached
1784  * attributes in a partially unrevalidated state, and @fattr
1785  * matches the change attribute of that partial update.
1786  * Otherwise returns '0'.
1787  */
nfs_inode_finish_partial_attr_update(const struct nfs_fattr * fattr,const struct inode * inode)1788 static int nfs_inode_finish_partial_attr_update(const struct nfs_fattr *fattr,
1789 						const struct inode *inode)
1790 {
1791 	const unsigned long check_valid =
1792 		NFS_INO_INVALID_ATIME | NFS_INO_INVALID_CTIME |
1793 		NFS_INO_INVALID_MTIME | NFS_INO_INVALID_SIZE |
1794 		NFS_INO_INVALID_BLOCKS | NFS_INO_INVALID_OTHER |
1795 		NFS_INO_INVALID_NLINK;
1796 	unsigned long cache_validity = NFS_I(inode)->cache_validity;
1797 	enum nfs4_change_attr_type ctype = NFS_SERVER(inode)->change_attr_type;
1798 
1799 	if (ctype != NFS4_CHANGE_TYPE_IS_UNDEFINED &&
1800 	    !(cache_validity & NFS_INO_INVALID_CHANGE) &&
1801 	    (cache_validity & check_valid) != 0 &&
1802 	    (fattr->valid & NFS_ATTR_FATTR_CHANGE) != 0 &&
1803 	    nfs_inode_attrs_cmp_monotonic(fattr, inode) == 0)
1804 		return 1;
1805 	return 0;
1806 }
1807 
nfs_refresh_inode_locked(struct inode * inode,struct nfs_fattr * fattr)1808 static int nfs_refresh_inode_locked(struct inode *inode,
1809 				    struct nfs_fattr *fattr)
1810 {
1811 	int attr_cmp = nfs_inode_attrs_cmp(fattr, inode);
1812 	int ret = 0;
1813 
1814 	trace_nfs_refresh_inode_enter(inode);
1815 
1816 	if (attr_cmp > 0 || nfs_inode_finish_partial_attr_update(fattr, inode))
1817 		ret = nfs_update_inode(inode, fattr);
1818 	else if (attr_cmp == 0)
1819 		ret = nfs_check_inode_attributes(inode, fattr);
1820 
1821 	trace_nfs_refresh_inode_exit(inode, ret);
1822 	return ret;
1823 }
1824 
1825 /**
1826  * nfs_refresh_inode - try to update the inode attribute cache
1827  * @inode: pointer to inode
1828  * @fattr: updated attributes
1829  *
1830  * Check that an RPC call that returned attributes has not overlapped with
1831  * other recent updates of the inode metadata, then decide whether it is
1832  * safe to do a full update of the inode attributes, or whether just to
1833  * call nfs_check_inode_attributes.
1834  */
nfs_refresh_inode(struct inode * inode,struct nfs_fattr * fattr)1835 int nfs_refresh_inode(struct inode *inode, struct nfs_fattr *fattr)
1836 {
1837 	int status;
1838 
1839 	if ((fattr->valid & NFS_ATTR_FATTR) == 0)
1840 		return 0;
1841 	spin_lock(&inode->i_lock);
1842 	status = nfs_refresh_inode_locked(inode, fattr);
1843 	spin_unlock(&inode->i_lock);
1844 
1845 	return status;
1846 }
1847 EXPORT_SYMBOL_GPL(nfs_refresh_inode);
1848 
nfs_post_op_update_inode_locked(struct inode * inode,struct nfs_fattr * fattr,unsigned int invalid)1849 static int nfs_post_op_update_inode_locked(struct inode *inode,
1850 		struct nfs_fattr *fattr, unsigned int invalid)
1851 {
1852 	if (S_ISDIR(inode->i_mode))
1853 		invalid |= NFS_INO_INVALID_DATA;
1854 	nfs_set_cache_invalid(inode, invalid);
1855 	if ((fattr->valid & NFS_ATTR_FATTR) == 0)
1856 		return 0;
1857 	return nfs_refresh_inode_locked(inode, fattr);
1858 }
1859 
1860 /**
1861  * nfs_post_op_update_inode - try to update the inode attribute cache
1862  * @inode: pointer to inode
1863  * @fattr: updated attributes
1864  *
1865  * After an operation that has changed the inode metadata, mark the
1866  * attribute cache as being invalid, then try to update it.
1867  *
1868  * NB: if the server didn't return any post op attributes, this
1869  * function will force the retrieval of attributes before the next
1870  * NFS request.  Thus it should be used only for operations that
1871  * are expected to change one or more attributes, to avoid
1872  * unnecessary NFS requests and trips through nfs_update_inode().
1873  */
nfs_post_op_update_inode(struct inode * inode,struct nfs_fattr * fattr)1874 int nfs_post_op_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1875 {
1876 	int status;
1877 
1878 	spin_lock(&inode->i_lock);
1879 	nfs_fattr_set_barrier(fattr);
1880 	status = nfs_post_op_update_inode_locked(inode, fattr,
1881 			NFS_INO_INVALID_CHANGE
1882 			| NFS_INO_INVALID_CTIME
1883 			| NFS_INO_REVAL_FORCED);
1884 	spin_unlock(&inode->i_lock);
1885 
1886 	return status;
1887 }
1888 EXPORT_SYMBOL_GPL(nfs_post_op_update_inode);
1889 
1890 /**
1891  * nfs_post_op_update_inode_force_wcc_locked - update the inode attribute cache
1892  * @inode: pointer to inode
1893  * @fattr: updated attributes
1894  *
1895  * After an operation that has changed the inode metadata, mark the
1896  * attribute cache as being invalid, then try to update it. Fake up
1897  * weak cache consistency data, if none exist.
1898  *
1899  * This function is mainly designed to be used by the ->write_done() functions.
1900  */
nfs_post_op_update_inode_force_wcc_locked(struct inode * inode,struct nfs_fattr * fattr)1901 int nfs_post_op_update_inode_force_wcc_locked(struct inode *inode, struct nfs_fattr *fattr)
1902 {
1903 	int attr_cmp = nfs_inode_attrs_cmp(fattr, inode);
1904 	int status;
1905 
1906 	/* Don't do a WCC update if these attributes are already stale */
1907 	if (attr_cmp < 0)
1908 		return 0;
1909 	if ((fattr->valid & NFS_ATTR_FATTR) == 0 || !attr_cmp) {
1910 		fattr->valid &= ~(NFS_ATTR_FATTR_PRECHANGE
1911 				| NFS_ATTR_FATTR_PRESIZE
1912 				| NFS_ATTR_FATTR_PREMTIME
1913 				| NFS_ATTR_FATTR_PRECTIME);
1914 		goto out_noforce;
1915 	}
1916 	if ((fattr->valid & NFS_ATTR_FATTR_CHANGE) != 0 &&
1917 			(fattr->valid & NFS_ATTR_FATTR_PRECHANGE) == 0) {
1918 		fattr->pre_change_attr = inode_peek_iversion_raw(inode);
1919 		fattr->valid |= NFS_ATTR_FATTR_PRECHANGE;
1920 	}
1921 	if ((fattr->valid & NFS_ATTR_FATTR_CTIME) != 0 &&
1922 			(fattr->valid & NFS_ATTR_FATTR_PRECTIME) == 0) {
1923 		fattr->pre_ctime = inode->i_ctime;
1924 		fattr->valid |= NFS_ATTR_FATTR_PRECTIME;
1925 	}
1926 	if ((fattr->valid & NFS_ATTR_FATTR_MTIME) != 0 &&
1927 			(fattr->valid & NFS_ATTR_FATTR_PREMTIME) == 0) {
1928 		fattr->pre_mtime = inode->i_mtime;
1929 		fattr->valid |= NFS_ATTR_FATTR_PREMTIME;
1930 	}
1931 	if ((fattr->valid & NFS_ATTR_FATTR_SIZE) != 0 &&
1932 			(fattr->valid & NFS_ATTR_FATTR_PRESIZE) == 0) {
1933 		fattr->pre_size = i_size_read(inode);
1934 		fattr->valid |= NFS_ATTR_FATTR_PRESIZE;
1935 	}
1936 out_noforce:
1937 	status = nfs_post_op_update_inode_locked(inode, fattr,
1938 			NFS_INO_INVALID_CHANGE
1939 			| NFS_INO_INVALID_CTIME
1940 			| NFS_INO_INVALID_MTIME
1941 			| NFS_INO_INVALID_BLOCKS);
1942 	return status;
1943 }
1944 
1945 /**
1946  * nfs_post_op_update_inode_force_wcc - try to update the inode attribute cache
1947  * @inode: pointer to inode
1948  * @fattr: updated attributes
1949  *
1950  * After an operation that has changed the inode metadata, mark the
1951  * attribute cache as being invalid, then try to update it. Fake up
1952  * weak cache consistency data, if none exist.
1953  *
1954  * This function is mainly designed to be used by the ->write_done() functions.
1955  */
nfs_post_op_update_inode_force_wcc(struct inode * inode,struct nfs_fattr * fattr)1956 int nfs_post_op_update_inode_force_wcc(struct inode *inode, struct nfs_fattr *fattr)
1957 {
1958 	int status;
1959 
1960 	spin_lock(&inode->i_lock);
1961 	nfs_fattr_set_barrier(fattr);
1962 	status = nfs_post_op_update_inode_force_wcc_locked(inode, fattr);
1963 	spin_unlock(&inode->i_lock);
1964 	return status;
1965 }
1966 EXPORT_SYMBOL_GPL(nfs_post_op_update_inode_force_wcc);
1967 
1968 
1969 /*
1970  * Many nfs protocol calls return the new file attributes after
1971  * an operation.  Here we update the inode to reflect the state
1972  * of the server's inode.
1973  *
1974  * This is a bit tricky because we have to make sure all dirty pages
1975  * have been sent off to the server before calling invalidate_inode_pages.
1976  * To make sure no other process adds more write requests while we try
1977  * our best to flush them, we make them sleep during the attribute refresh.
1978  *
1979  * A very similar scenario holds for the dir cache.
1980  */
nfs_update_inode(struct inode * inode,struct nfs_fattr * fattr)1981 static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1982 {
1983 	struct nfs_server *server = NFS_SERVER(inode);
1984 	struct nfs_inode *nfsi = NFS_I(inode);
1985 	loff_t cur_isize, new_isize;
1986 	u64 fattr_supported = server->fattr_valid;
1987 	unsigned long invalid = 0;
1988 	unsigned long now = jiffies;
1989 	unsigned long save_cache_validity;
1990 	bool have_writers = nfs_file_has_buffered_writers(nfsi);
1991 	bool cache_revalidated = true;
1992 	bool attr_changed = false;
1993 	bool have_delegation;
1994 
1995 	dfprintk(VFS, "NFS: %s(%s/%lu fh_crc=0x%08x ct=%d info=0x%x)\n",
1996 			__func__, inode->i_sb->s_id, inode->i_ino,
1997 			nfs_display_fhandle_hash(NFS_FH(inode)),
1998 			atomic_read(&inode->i_count), fattr->valid);
1999 
2000 	if (!(fattr->valid & NFS_ATTR_FATTR_FILEID)) {
2001 		/* Only a mounted-on-fileid? Just exit */
2002 		if (fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID)
2003 			return 0;
2004 	/* Has the inode gone and changed behind our back? */
2005 	} else if (nfsi->fileid != fattr->fileid) {
2006 		/* Is this perhaps the mounted-on fileid? */
2007 		if ((fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID) &&
2008 		    nfsi->fileid == fattr->mounted_on_fileid)
2009 			return 0;
2010 		printk(KERN_ERR "NFS: server %s error: fileid changed\n"
2011 			"fsid %s: expected fileid 0x%Lx, got 0x%Lx\n",
2012 			NFS_SERVER(inode)->nfs_client->cl_hostname,
2013 			inode->i_sb->s_id, (long long)nfsi->fileid,
2014 			(long long)fattr->fileid);
2015 		goto out_err;
2016 	}
2017 
2018 	/*
2019 	 * Make sure the inode's type hasn't changed.
2020 	 */
2021 	if ((fattr->valid & NFS_ATTR_FATTR_TYPE) && inode_wrong_type(inode, fattr->mode)) {
2022 		/*
2023 		* Big trouble! The inode has become a different object.
2024 		*/
2025 		printk(KERN_DEBUG "NFS: %s: inode %lu mode changed, %07o to %07o\n",
2026 				__func__, inode->i_ino, inode->i_mode, fattr->mode);
2027 		goto out_err;
2028 	}
2029 
2030 	/* Update the fsid? */
2031 	if (S_ISDIR(inode->i_mode) && (fattr->valid & NFS_ATTR_FATTR_FSID) &&
2032 			!nfs_fsid_equal(&server->fsid, &fattr->fsid) &&
2033 			!IS_AUTOMOUNT(inode))
2034 		server->fsid = fattr->fsid;
2035 
2036 	/* Save the delegation state before clearing cache_validity */
2037 	have_delegation = nfs_have_delegated_attributes(inode);
2038 
2039 	/*
2040 	 * Update the read time so we don't revalidate too often.
2041 	 */
2042 	nfsi->read_cache_jiffies = fattr->time_start;
2043 
2044 	save_cache_validity = nfsi->cache_validity;
2045 	nfsi->cache_validity &= ~(NFS_INO_INVALID_ATTR
2046 			| NFS_INO_INVALID_ATIME
2047 			| NFS_INO_REVAL_FORCED
2048 			| NFS_INO_INVALID_BLOCKS);
2049 
2050 	/* Do atomic weak cache consistency updates */
2051 	nfs_wcc_update_inode(inode, fattr);
2052 
2053 	if (pnfs_layoutcommit_outstanding(inode)) {
2054 		nfsi->cache_validity |=
2055 			save_cache_validity &
2056 			(NFS_INO_INVALID_CHANGE | NFS_INO_INVALID_CTIME |
2057 			 NFS_INO_INVALID_MTIME | NFS_INO_INVALID_SIZE |
2058 			 NFS_INO_INVALID_BLOCKS);
2059 		cache_revalidated = false;
2060 	}
2061 
2062 	/* More cache consistency checks */
2063 	if (fattr->valid & NFS_ATTR_FATTR_CHANGE) {
2064 		if (!inode_eq_iversion_raw(inode, fattr->change_attr)) {
2065 			/* Could it be a race with writeback? */
2066 			if (!(have_writers || have_delegation)) {
2067 				invalid |= NFS_INO_INVALID_DATA
2068 					| NFS_INO_INVALID_ACCESS
2069 					| NFS_INO_INVALID_ACL
2070 					| NFS_INO_INVALID_XATTR;
2071 				/* Force revalidate of all attributes */
2072 				save_cache_validity |= NFS_INO_INVALID_CTIME
2073 					| NFS_INO_INVALID_MTIME
2074 					| NFS_INO_INVALID_SIZE
2075 					| NFS_INO_INVALID_BLOCKS
2076 					| NFS_INO_INVALID_NLINK
2077 					| NFS_INO_INVALID_MODE
2078 					| NFS_INO_INVALID_OTHER;
2079 				if (S_ISDIR(inode->i_mode))
2080 					nfs_force_lookup_revalidate(inode);
2081 				attr_changed = true;
2082 				dprintk("NFS: change_attr change on server for file %s/%ld\n",
2083 						inode->i_sb->s_id,
2084 						inode->i_ino);
2085 			} else if (!have_delegation)
2086 				nfsi->cache_validity |= NFS_INO_DATA_INVAL_DEFER;
2087 			inode_set_iversion_raw(inode, fattr->change_attr);
2088 		}
2089 	} else {
2090 		nfsi->cache_validity |=
2091 			save_cache_validity & NFS_INO_INVALID_CHANGE;
2092 		if (!have_delegation ||
2093 		    (nfsi->cache_validity & NFS_INO_INVALID_CHANGE) != 0)
2094 			cache_revalidated = false;
2095 	}
2096 
2097 	if (fattr->valid & NFS_ATTR_FATTR_MTIME)
2098 		inode->i_mtime = fattr->mtime;
2099 	else if (fattr_supported & NFS_ATTR_FATTR_MTIME)
2100 		nfsi->cache_validity |=
2101 			save_cache_validity & NFS_INO_INVALID_MTIME;
2102 
2103 	if (fattr->valid & NFS_ATTR_FATTR_CTIME)
2104 		inode->i_ctime = fattr->ctime;
2105 	else if (fattr_supported & NFS_ATTR_FATTR_CTIME)
2106 		nfsi->cache_validity |=
2107 			save_cache_validity & NFS_INO_INVALID_CTIME;
2108 
2109 	/* Check if our cached file size is stale */
2110 	if (fattr->valid & NFS_ATTR_FATTR_SIZE) {
2111 		new_isize = nfs_size_to_loff_t(fattr->size);
2112 		cur_isize = i_size_read(inode);
2113 		if (new_isize != cur_isize && !have_delegation) {
2114 			/* Do we perhaps have any outstanding writes, or has
2115 			 * the file grown beyond our last write? */
2116 			if (!nfs_have_writebacks(inode) || new_isize > cur_isize) {
2117 				trace_nfs_size_update(inode, new_isize);
2118 				i_size_write(inode, new_isize);
2119 				if (!have_writers)
2120 					invalid |= NFS_INO_INVALID_DATA;
2121 			}
2122 		}
2123 		if (new_isize == 0 &&
2124 		    !(fattr->valid & (NFS_ATTR_FATTR_SPACE_USED |
2125 				      NFS_ATTR_FATTR_BLOCKS_USED))) {
2126 			fattr->du.nfs3.used = 0;
2127 			fattr->valid |= NFS_ATTR_FATTR_SPACE_USED;
2128 		}
2129 	} else
2130 		nfsi->cache_validity |=
2131 			save_cache_validity & NFS_INO_INVALID_SIZE;
2132 
2133 	if (fattr->valid & NFS_ATTR_FATTR_ATIME)
2134 		inode->i_atime = fattr->atime;
2135 	else if (fattr_supported & NFS_ATTR_FATTR_ATIME)
2136 		nfsi->cache_validity |=
2137 			save_cache_validity & NFS_INO_INVALID_ATIME;
2138 
2139 	if (fattr->valid & NFS_ATTR_FATTR_MODE) {
2140 		if ((inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO)) {
2141 			umode_t newmode = inode->i_mode & S_IFMT;
2142 			newmode |= fattr->mode & S_IALLUGO;
2143 			inode->i_mode = newmode;
2144 			invalid |= NFS_INO_INVALID_ACCESS
2145 				| NFS_INO_INVALID_ACL;
2146 		}
2147 	} else if (fattr_supported & NFS_ATTR_FATTR_MODE)
2148 		nfsi->cache_validity |=
2149 			save_cache_validity & NFS_INO_INVALID_MODE;
2150 
2151 	if (fattr->valid & NFS_ATTR_FATTR_OWNER) {
2152 		if (!uid_eq(inode->i_uid, fattr->uid)) {
2153 			invalid |= NFS_INO_INVALID_ACCESS
2154 				| NFS_INO_INVALID_ACL;
2155 			inode->i_uid = fattr->uid;
2156 		}
2157 	} else if (fattr_supported & NFS_ATTR_FATTR_OWNER)
2158 		nfsi->cache_validity |=
2159 			save_cache_validity & NFS_INO_INVALID_OTHER;
2160 
2161 	if (fattr->valid & NFS_ATTR_FATTR_GROUP) {
2162 		if (!gid_eq(inode->i_gid, fattr->gid)) {
2163 			invalid |= NFS_INO_INVALID_ACCESS
2164 				| NFS_INO_INVALID_ACL;
2165 			inode->i_gid = fattr->gid;
2166 		}
2167 	} else if (fattr_supported & NFS_ATTR_FATTR_GROUP)
2168 		nfsi->cache_validity |=
2169 			save_cache_validity & NFS_INO_INVALID_OTHER;
2170 
2171 	if (fattr->valid & NFS_ATTR_FATTR_NLINK) {
2172 		if (inode->i_nlink != fattr->nlink)
2173 			set_nlink(inode, fattr->nlink);
2174 	} else if (fattr_supported & NFS_ATTR_FATTR_NLINK)
2175 		nfsi->cache_validity |=
2176 			save_cache_validity & NFS_INO_INVALID_NLINK;
2177 
2178 	if (fattr->valid & NFS_ATTR_FATTR_SPACE_USED) {
2179 		/*
2180 		 * report the blocks in 512byte units
2181 		 */
2182 		inode->i_blocks = nfs_calc_block_size(fattr->du.nfs3.used);
2183 	} else if (fattr_supported & NFS_ATTR_FATTR_SPACE_USED)
2184 		nfsi->cache_validity |=
2185 			save_cache_validity & NFS_INO_INVALID_BLOCKS;
2186 
2187 	if (fattr->valid & NFS_ATTR_FATTR_BLOCKS_USED)
2188 		inode->i_blocks = fattr->du.nfs2.blocks;
2189 	else if (fattr_supported & NFS_ATTR_FATTR_BLOCKS_USED)
2190 		nfsi->cache_validity |=
2191 			save_cache_validity & NFS_INO_INVALID_BLOCKS;
2192 
2193 	/* Update attrtimeo value if we're out of the unstable period */
2194 	if (attr_changed) {
2195 		nfs_inc_stats(inode, NFSIOS_ATTRINVALIDATE);
2196 		nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
2197 		nfsi->attrtimeo_timestamp = now;
2198 		/* Set barrier to be more recent than all outstanding updates */
2199 		nfsi->attr_gencount = nfs_inc_attr_generation_counter();
2200 	} else {
2201 		if (cache_revalidated) {
2202 			if (!time_in_range_open(now, nfsi->attrtimeo_timestamp,
2203 				nfsi->attrtimeo_timestamp + nfsi->attrtimeo)) {
2204 				nfsi->attrtimeo <<= 1;
2205 				if (nfsi->attrtimeo > NFS_MAXATTRTIMEO(inode))
2206 					nfsi->attrtimeo = NFS_MAXATTRTIMEO(inode);
2207 			}
2208 			nfsi->attrtimeo_timestamp = now;
2209 		}
2210 		/* Set the barrier to be more recent than this fattr */
2211 		if ((long)(fattr->gencount - nfsi->attr_gencount) > 0)
2212 			nfsi->attr_gencount = fattr->gencount;
2213 	}
2214 
2215 	/* Don't invalidate the data if we were to blame */
2216 	if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)
2217 				|| S_ISLNK(inode->i_mode)))
2218 		invalid &= ~NFS_INO_INVALID_DATA;
2219 	nfs_set_cache_invalid(inode, invalid);
2220 
2221 	return 0;
2222  out_err:
2223 	/*
2224 	 * No need to worry about unhashing the dentry, as the
2225 	 * lookup validation will know that the inode is bad.
2226 	 * (But we fall through to invalidate the caches.)
2227 	 */
2228 	nfs_set_inode_stale_locked(inode);
2229 	return -ESTALE;
2230 }
2231 
nfs_alloc_inode(struct super_block * sb)2232 struct inode *nfs_alloc_inode(struct super_block *sb)
2233 {
2234 	struct nfs_inode *nfsi;
2235 	nfsi = alloc_inode_sb(sb, nfs_inode_cachep, GFP_KERNEL);
2236 	if (!nfsi)
2237 		return NULL;
2238 	nfsi->flags = 0UL;
2239 	nfsi->cache_validity = 0UL;
2240 #if IS_ENABLED(CONFIG_NFS_V4)
2241 	nfsi->nfs4_acl = NULL;
2242 #endif /* CONFIG_NFS_V4 */
2243 #ifdef CONFIG_NFS_V4_2
2244 	nfsi->xattr_cache = NULL;
2245 #endif
2246 	return &nfsi->vfs_inode;
2247 }
2248 EXPORT_SYMBOL_GPL(nfs_alloc_inode);
2249 
nfs_free_inode(struct inode * inode)2250 void nfs_free_inode(struct inode *inode)
2251 {
2252 	kmem_cache_free(nfs_inode_cachep, NFS_I(inode));
2253 }
2254 EXPORT_SYMBOL_GPL(nfs_free_inode);
2255 
nfs4_init_once(struct nfs_inode * nfsi)2256 static inline void nfs4_init_once(struct nfs_inode *nfsi)
2257 {
2258 #if IS_ENABLED(CONFIG_NFS_V4)
2259 	INIT_LIST_HEAD(&nfsi->open_states);
2260 	nfsi->delegation = NULL;
2261 	init_rwsem(&nfsi->rwsem);
2262 	nfsi->layout = NULL;
2263 #endif
2264 }
2265 
init_once(void * foo)2266 static void init_once(void *foo)
2267 {
2268 	struct nfs_inode *nfsi = foo;
2269 
2270 	inode_init_once(&nfsi->vfs_inode);
2271 	INIT_LIST_HEAD(&nfsi->open_files);
2272 	INIT_LIST_HEAD(&nfsi->access_cache_entry_lru);
2273 	INIT_LIST_HEAD(&nfsi->access_cache_inode_lru);
2274 	nfs4_init_once(nfsi);
2275 }
2276 
nfs_init_inodecache(void)2277 static int __init nfs_init_inodecache(void)
2278 {
2279 	nfs_inode_cachep = kmem_cache_create("nfs_inode_cache",
2280 					     sizeof(struct nfs_inode),
2281 					     0, (SLAB_RECLAIM_ACCOUNT|
2282 						SLAB_MEM_SPREAD|SLAB_ACCOUNT),
2283 					     init_once);
2284 	if (nfs_inode_cachep == NULL)
2285 		return -ENOMEM;
2286 
2287 	return 0;
2288 }
2289 
nfs_destroy_inodecache(void)2290 static void nfs_destroy_inodecache(void)
2291 {
2292 	/*
2293 	 * Make sure all delayed rcu free inodes are flushed before we
2294 	 * destroy cache.
2295 	 */
2296 	rcu_barrier();
2297 	kmem_cache_destroy(nfs_inode_cachep);
2298 }
2299 
2300 struct workqueue_struct *nfsiod_workqueue;
2301 EXPORT_SYMBOL_GPL(nfsiod_workqueue);
2302 
2303 /*
2304  * start up the nfsiod workqueue
2305  */
nfsiod_start(void)2306 static int nfsiod_start(void)
2307 {
2308 	struct workqueue_struct *wq;
2309 	dprintk("RPC:       creating workqueue nfsiod\n");
2310 	wq = alloc_workqueue("nfsiod", WQ_MEM_RECLAIM | WQ_UNBOUND, 0);
2311 	if (wq == NULL)
2312 		return -ENOMEM;
2313 	nfsiod_workqueue = wq;
2314 	return 0;
2315 }
2316 
2317 /*
2318  * Destroy the nfsiod workqueue
2319  */
nfsiod_stop(void)2320 static void nfsiod_stop(void)
2321 {
2322 	struct workqueue_struct *wq;
2323 
2324 	wq = nfsiod_workqueue;
2325 	if (wq == NULL)
2326 		return;
2327 	nfsiod_workqueue = NULL;
2328 	destroy_workqueue(wq);
2329 }
2330 
2331 unsigned int nfs_net_id;
2332 EXPORT_SYMBOL_GPL(nfs_net_id);
2333 
nfs_net_init(struct net * net)2334 static int nfs_net_init(struct net *net)
2335 {
2336 	nfs_clients_init(net);
2337 	return nfs_fs_proc_net_init(net);
2338 }
2339 
nfs_net_exit(struct net * net)2340 static void nfs_net_exit(struct net *net)
2341 {
2342 	nfs_fs_proc_net_exit(net);
2343 	nfs_clients_exit(net);
2344 }
2345 
2346 static struct pernet_operations nfs_net_ops = {
2347 	.init = nfs_net_init,
2348 	.exit = nfs_net_exit,
2349 	.id   = &nfs_net_id,
2350 	.size = sizeof(struct nfs_net),
2351 };
2352 
2353 /*
2354  * Initialize NFS
2355  */
init_nfs_fs(void)2356 static int __init init_nfs_fs(void)
2357 {
2358 	int err;
2359 
2360 	err = nfs_sysfs_init();
2361 	if (err < 0)
2362 		goto out10;
2363 
2364 	err = register_pernet_subsys(&nfs_net_ops);
2365 	if (err < 0)
2366 		goto out9;
2367 
2368 	err = nfsiod_start();
2369 	if (err)
2370 		goto out7;
2371 
2372 	err = nfs_fs_proc_init();
2373 	if (err)
2374 		goto out6;
2375 
2376 	err = nfs_init_nfspagecache();
2377 	if (err)
2378 		goto out5;
2379 
2380 	err = nfs_init_inodecache();
2381 	if (err)
2382 		goto out4;
2383 
2384 	err = nfs_init_readpagecache();
2385 	if (err)
2386 		goto out3;
2387 
2388 	err = nfs_init_writepagecache();
2389 	if (err)
2390 		goto out2;
2391 
2392 	err = nfs_init_directcache();
2393 	if (err)
2394 		goto out1;
2395 
2396 	rpc_proc_register(&init_net, &nfs_rpcstat);
2397 
2398 	err = register_nfs_fs();
2399 	if (err)
2400 		goto out0;
2401 
2402 	return 0;
2403 out0:
2404 	rpc_proc_unregister(&init_net, "nfs");
2405 	nfs_destroy_directcache();
2406 out1:
2407 	nfs_destroy_writepagecache();
2408 out2:
2409 	nfs_destroy_readpagecache();
2410 out3:
2411 	nfs_destroy_inodecache();
2412 out4:
2413 	nfs_destroy_nfspagecache();
2414 out5:
2415 	nfs_fs_proc_exit();
2416 out6:
2417 	nfsiod_stop();
2418 out7:
2419 	unregister_pernet_subsys(&nfs_net_ops);
2420 out9:
2421 	nfs_sysfs_exit();
2422 out10:
2423 	return err;
2424 }
2425 
exit_nfs_fs(void)2426 static void __exit exit_nfs_fs(void)
2427 {
2428 	nfs_destroy_directcache();
2429 	nfs_destroy_writepagecache();
2430 	nfs_destroy_readpagecache();
2431 	nfs_destroy_inodecache();
2432 	nfs_destroy_nfspagecache();
2433 	unregister_pernet_subsys(&nfs_net_ops);
2434 	rpc_proc_unregister(&init_net, "nfs");
2435 	unregister_nfs_fs();
2436 	nfs_fs_proc_exit();
2437 	nfsiod_stop();
2438 	nfs_sysfs_exit();
2439 }
2440 
2441 /* Not quite true; I just maintain it */
2442 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
2443 MODULE_LICENSE("GPL");
2444 module_param(enable_ino64, bool, 0644);
2445 
2446 module_init(init_nfs_fs)
2447 module_exit(exit_nfs_fs)
2448