xref: /linux/fs/nfs/inode.c (revision de2fe5e07d58424bc286fff3fd3c1b0bf933cd58)
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.Cox@linux.org>, 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/config.h>
17 #include <linux/module.h>
18 #include <linux/init.h>
19 
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/smp_lock.h>
35 #include <linux/seq_file.h>
36 #include <linux/mount.h>
37 #include <linux/nfs_idmap.h>
38 #include <linux/vfs.h>
39 
40 #include <asm/system.h>
41 #include <asm/uaccess.h>
42 
43 #include "nfs4_fs.h"
44 #include "callback.h"
45 #include "delegation.h"
46 #include "iostat.h"
47 
48 #define NFSDBG_FACILITY		NFSDBG_VFS
49 #define NFS_PARANOIA 1
50 
51 /* Maximum number of readahead requests
52  * FIXME: this should really be a sysctl so that users may tune it to suit
53  *        their needs. People that do NFS over a slow network, might for
54  *        instance want to reduce it to something closer to 1 for improved
55  *        interactive response.
56  */
57 #define NFS_MAX_READAHEAD	(RPC_DEF_SLOT_TABLE - 1)
58 
59 static void nfs_invalidate_inode(struct inode *);
60 static int nfs_update_inode(struct inode *, struct nfs_fattr *);
61 
62 static struct inode *nfs_alloc_inode(struct super_block *sb);
63 static void nfs_destroy_inode(struct inode *);
64 static int nfs_write_inode(struct inode *,int);
65 static void nfs_delete_inode(struct inode *);
66 static void nfs_clear_inode(struct inode *);
67 static void nfs_umount_begin(struct super_block *);
68 static int  nfs_statfs(struct super_block *, struct kstatfs *);
69 static int  nfs_show_options(struct seq_file *, struct vfsmount *);
70 static int  nfs_show_stats(struct seq_file *, struct vfsmount *);
71 static void nfs_zap_acl_cache(struct inode *);
72 
73 static struct rpc_program	nfs_program;
74 
75 static struct super_operations nfs_sops = {
76 	.alloc_inode	= nfs_alloc_inode,
77 	.destroy_inode	= nfs_destroy_inode,
78 	.write_inode	= nfs_write_inode,
79 	.delete_inode	= nfs_delete_inode,
80 	.statfs		= nfs_statfs,
81 	.clear_inode	= nfs_clear_inode,
82 	.umount_begin	= nfs_umount_begin,
83 	.show_options	= nfs_show_options,
84 	.show_stats	= nfs_show_stats,
85 };
86 
87 /*
88  * RPC cruft for NFS
89  */
90 static struct rpc_stat		nfs_rpcstat = {
91 	.program		= &nfs_program
92 };
93 static struct rpc_version *	nfs_version[] = {
94 	NULL,
95 	NULL,
96 	&nfs_version2,
97 #if defined(CONFIG_NFS_V3)
98 	&nfs_version3,
99 #elif defined(CONFIG_NFS_V4)
100 	NULL,
101 #endif
102 #if defined(CONFIG_NFS_V4)
103 	&nfs_version4,
104 #endif
105 };
106 
107 static struct rpc_program	nfs_program = {
108 	.name			= "nfs",
109 	.number			= NFS_PROGRAM,
110 	.nrvers			= ARRAY_SIZE(nfs_version),
111 	.version		= nfs_version,
112 	.stats			= &nfs_rpcstat,
113 	.pipe_dir_name		= "/nfs",
114 };
115 
116 #ifdef CONFIG_NFS_V3_ACL
117 static struct rpc_stat		nfsacl_rpcstat = { &nfsacl_program };
118 static struct rpc_version *	nfsacl_version[] = {
119 	[3]			= &nfsacl_version3,
120 };
121 
122 struct rpc_program		nfsacl_program = {
123 	.name =			"nfsacl",
124 	.number =		NFS_ACL_PROGRAM,
125 	.nrvers =		ARRAY_SIZE(nfsacl_version),
126 	.version =		nfsacl_version,
127 	.stats =		&nfsacl_rpcstat,
128 };
129 #endif  /* CONFIG_NFS_V3_ACL */
130 
131 static inline unsigned long
132 nfs_fattr_to_ino_t(struct nfs_fattr *fattr)
133 {
134 	return nfs_fileid_to_ino_t(fattr->fileid);
135 }
136 
137 static int
138 nfs_write_inode(struct inode *inode, int sync)
139 {
140 	int flags = sync ? FLUSH_SYNC : 0;
141 	int ret;
142 
143 	ret = nfs_commit_inode(inode, flags);
144 	if (ret < 0)
145 		return ret;
146 	return 0;
147 }
148 
149 static void
150 nfs_delete_inode(struct inode * inode)
151 {
152 	dprintk("NFS: delete_inode(%s/%ld)\n", inode->i_sb->s_id, inode->i_ino);
153 
154 	truncate_inode_pages(&inode->i_data, 0);
155 
156 	nfs_wb_all(inode);
157 	/*
158 	 * The following should never happen...
159 	 */
160 	if (nfs_have_writebacks(inode)) {
161 		printk(KERN_ERR "nfs_delete_inode: inode %ld has pending RPC requests\n", inode->i_ino);
162 	}
163 
164 	clear_inode(inode);
165 }
166 
167 static void
168 nfs_clear_inode(struct inode *inode)
169 {
170 	struct nfs_inode *nfsi = NFS_I(inode);
171 	struct rpc_cred *cred;
172 
173 	nfs_wb_all(inode);
174 	BUG_ON (!list_empty(&nfsi->open_files));
175 	nfs_zap_acl_cache(inode);
176 	cred = nfsi->cache_access.cred;
177 	if (cred)
178 		put_rpccred(cred);
179 	BUG_ON(atomic_read(&nfsi->data_updates) != 0);
180 }
181 
182 void
183 nfs_umount_begin(struct super_block *sb)
184 {
185 	struct rpc_clnt	*rpc = NFS_SB(sb)->client;
186 
187 	/* -EIO all pending I/O */
188 	if (!IS_ERR(rpc))
189 		rpc_killall_tasks(rpc);
190 	rpc = NFS_SB(sb)->client_acl;
191 	if (!IS_ERR(rpc))
192 		rpc_killall_tasks(rpc);
193 }
194 
195 
196 static inline unsigned long
197 nfs_block_bits(unsigned long bsize, unsigned char *nrbitsp)
198 {
199 	/* make sure blocksize is a power of two */
200 	if ((bsize & (bsize - 1)) || nrbitsp) {
201 		unsigned char	nrbits;
202 
203 		for (nrbits = 31; nrbits && !(bsize & (1 << nrbits)); nrbits--)
204 			;
205 		bsize = 1 << nrbits;
206 		if (nrbitsp)
207 			*nrbitsp = nrbits;
208 	}
209 
210 	return bsize;
211 }
212 
213 /*
214  * Calculate the number of 512byte blocks used.
215  */
216 static inline unsigned long
217 nfs_calc_block_size(u64 tsize)
218 {
219 	loff_t used = (tsize + 511) >> 9;
220 	return (used > ULONG_MAX) ? ULONG_MAX : used;
221 }
222 
223 /*
224  * Compute and set NFS server blocksize
225  */
226 static inline unsigned long
227 nfs_block_size(unsigned long bsize, unsigned char *nrbitsp)
228 {
229 	if (bsize < NFS_MIN_FILE_IO_SIZE)
230 		bsize = NFS_DEF_FILE_IO_SIZE;
231 	else if (bsize >= NFS_MAX_FILE_IO_SIZE)
232 		bsize = NFS_MAX_FILE_IO_SIZE;
233 
234 	return nfs_block_bits(bsize, nrbitsp);
235 }
236 
237 /*
238  * Obtain the root inode of the file system.
239  */
240 static struct inode *
241 nfs_get_root(struct super_block *sb, struct nfs_fh *rootfh, struct nfs_fsinfo *fsinfo)
242 {
243 	struct nfs_server	*server = NFS_SB(sb);
244 	int			error;
245 
246 	error = server->rpc_ops->getroot(server, rootfh, fsinfo);
247 	if (error < 0) {
248 		dprintk("nfs_get_root: getattr error = %d\n", -error);
249 		return ERR_PTR(error);
250 	}
251 
252 	return nfs_fhget(sb, rootfh, fsinfo->fattr);
253 }
254 
255 /*
256  * Do NFS version-independent mount processing, and sanity checking
257  */
258 static int
259 nfs_sb_init(struct super_block *sb, rpc_authflavor_t authflavor)
260 {
261 	struct nfs_server	*server;
262 	struct inode		*root_inode;
263 	struct nfs_fattr	fattr;
264 	struct nfs_fsinfo	fsinfo = {
265 					.fattr = &fattr,
266 				};
267 	struct nfs_pathconf pathinfo = {
268 			.fattr = &fattr,
269 	};
270 	int no_root_error = 0;
271 	unsigned long max_rpc_payload;
272 
273 	/* We probably want something more informative here */
274 	snprintf(sb->s_id, sizeof(sb->s_id), "%x:%x", MAJOR(sb->s_dev), MINOR(sb->s_dev));
275 
276 	server = NFS_SB(sb);
277 
278 	sb->s_magic      = NFS_SUPER_MAGIC;
279 
280 	server->io_stats = nfs_alloc_iostats();
281 	if (server->io_stats == NULL)
282 		return -ENOMEM;
283 
284 	root_inode = nfs_get_root(sb, &server->fh, &fsinfo);
285 	/* Did getting the root inode fail? */
286 	if (IS_ERR(root_inode)) {
287 		no_root_error = PTR_ERR(root_inode);
288 		goto out_no_root;
289 	}
290 	sb->s_root = d_alloc_root(root_inode);
291 	if (!sb->s_root) {
292 		no_root_error = -ENOMEM;
293 		goto out_no_root;
294 	}
295 	sb->s_root->d_op = server->rpc_ops->dentry_ops;
296 
297 	/* mount time stamp, in seconds */
298 	server->mount_time = jiffies;
299 
300 	/* Get some general file system info */
301 	if (server->namelen == 0 &&
302 	    server->rpc_ops->pathconf(server, &server->fh, &pathinfo) >= 0)
303 		server->namelen = pathinfo.max_namelen;
304 	/* Work out a lot of parameters */
305 	if (server->rsize == 0)
306 		server->rsize = nfs_block_size(fsinfo.rtpref, NULL);
307 	if (server->wsize == 0)
308 		server->wsize = nfs_block_size(fsinfo.wtpref, NULL);
309 
310 	if (fsinfo.rtmax >= 512 && server->rsize > fsinfo.rtmax)
311 		server->rsize = nfs_block_size(fsinfo.rtmax, NULL);
312 	if (fsinfo.wtmax >= 512 && server->wsize > fsinfo.wtmax)
313 		server->wsize = nfs_block_size(fsinfo.wtmax, NULL);
314 
315 	max_rpc_payload = nfs_block_size(rpc_max_payload(server->client), NULL);
316 	if (server->rsize > max_rpc_payload)
317 		server->rsize = max_rpc_payload;
318 	if (server->rsize > NFS_MAX_FILE_IO_SIZE)
319 		server->rsize = NFS_MAX_FILE_IO_SIZE;
320 	server->rpages = (server->rsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
321 
322 	if (server->wsize > max_rpc_payload)
323 		server->wsize = max_rpc_payload;
324 	if (server->wsize > NFS_MAX_FILE_IO_SIZE)
325 		server->wsize = NFS_MAX_FILE_IO_SIZE;
326 	server->wpages = (server->wsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
327 
328 	if (sb->s_blocksize == 0)
329 		sb->s_blocksize = nfs_block_bits(server->wsize,
330 							 &sb->s_blocksize_bits);
331 	server->wtmult = nfs_block_bits(fsinfo.wtmult, NULL);
332 
333 	server->dtsize = nfs_block_size(fsinfo.dtpref, NULL);
334 	if (server->dtsize > PAGE_CACHE_SIZE)
335 		server->dtsize = PAGE_CACHE_SIZE;
336 	if (server->dtsize > server->rsize)
337 		server->dtsize = server->rsize;
338 
339 	if (server->flags & NFS_MOUNT_NOAC) {
340 		server->acregmin = server->acregmax = 0;
341 		server->acdirmin = server->acdirmax = 0;
342 		sb->s_flags |= MS_SYNCHRONOUS;
343 	}
344 	server->backing_dev_info.ra_pages = server->rpages * NFS_MAX_READAHEAD;
345 
346 	sb->s_maxbytes = fsinfo.maxfilesize;
347 	if (sb->s_maxbytes > MAX_LFS_FILESIZE)
348 		sb->s_maxbytes = MAX_LFS_FILESIZE;
349 
350 	server->client->cl_intr = (server->flags & NFS_MOUNT_INTR) ? 1 : 0;
351 	server->client->cl_softrtry = (server->flags & NFS_MOUNT_SOFT) ? 1 : 0;
352 
353 	/* We're airborne Set socket buffersize */
354 	rpc_setbufsize(server->client, server->wsize + 100, server->rsize + 100);
355 	return 0;
356 	/* Yargs. It didn't work out. */
357 out_no_root:
358 	dprintk("nfs_sb_init: get root inode failed: errno %d\n", -no_root_error);
359 	if (!IS_ERR(root_inode))
360 		iput(root_inode);
361 	return no_root_error;
362 }
363 
364 static void nfs_init_timeout_values(struct rpc_timeout *to, int proto, unsigned int timeo, unsigned int retrans)
365 {
366 	to->to_initval = timeo * HZ / 10;
367 	to->to_retries = retrans;
368 	if (!to->to_retries)
369 		to->to_retries = 2;
370 
371 	switch (proto) {
372 	case IPPROTO_TCP:
373 		if (!to->to_initval)
374 			to->to_initval = 60 * HZ;
375 		if (to->to_initval > NFS_MAX_TCP_TIMEOUT)
376 			to->to_initval = NFS_MAX_TCP_TIMEOUT;
377 		to->to_increment = to->to_initval;
378 		to->to_maxval = to->to_initval + (to->to_increment * to->to_retries);
379 		to->to_exponential = 0;
380 		break;
381 	case IPPROTO_UDP:
382 	default:
383 		if (!to->to_initval)
384 			to->to_initval = 11 * HZ / 10;
385 		if (to->to_initval > NFS_MAX_UDP_TIMEOUT)
386 			to->to_initval = NFS_MAX_UDP_TIMEOUT;
387 		to->to_maxval = NFS_MAX_UDP_TIMEOUT;
388 		to->to_exponential = 1;
389 		break;
390 	}
391 }
392 
393 /*
394  * Create an RPC client handle.
395  */
396 static struct rpc_clnt *
397 nfs_create_client(struct nfs_server *server, const struct nfs_mount_data *data)
398 {
399 	struct rpc_timeout	timeparms;
400 	struct rpc_xprt		*xprt = NULL;
401 	struct rpc_clnt		*clnt = NULL;
402 	int			proto = (data->flags & NFS_MOUNT_TCP) ? IPPROTO_TCP : IPPROTO_UDP;
403 
404 	nfs_init_timeout_values(&timeparms, proto, data->timeo, data->retrans);
405 
406 	server->retrans_timeo = timeparms.to_initval;
407 	server->retrans_count = timeparms.to_retries;
408 
409 	/* create transport and client */
410 	xprt = xprt_create_proto(proto, &server->addr, &timeparms);
411 	if (IS_ERR(xprt)) {
412 		dprintk("%s: cannot create RPC transport. Error = %ld\n",
413 				__FUNCTION__, PTR_ERR(xprt));
414 		return (struct rpc_clnt *)xprt;
415 	}
416 	clnt = rpc_create_client(xprt, server->hostname, &nfs_program,
417 				 server->rpc_ops->version, data->pseudoflavor);
418 	if (IS_ERR(clnt)) {
419 		dprintk("%s: cannot create RPC client. Error = %ld\n",
420 				__FUNCTION__, PTR_ERR(xprt));
421 		goto out_fail;
422 	}
423 
424 	clnt->cl_intr     = 1;
425 	clnt->cl_softrtry = 1;
426 
427 	return clnt;
428 
429 out_fail:
430 	return clnt;
431 }
432 
433 /*
434  * The way this works is that the mount process passes a structure
435  * in the data argument which contains the server's IP address
436  * and the root file handle obtained from the server's mount
437  * daemon. We stash these away in the private superblock fields.
438  */
439 static int
440 nfs_fill_super(struct super_block *sb, struct nfs_mount_data *data, int silent)
441 {
442 	struct nfs_server	*server;
443 	rpc_authflavor_t	authflavor;
444 
445 	server           = NFS_SB(sb);
446 	sb->s_blocksize_bits = 0;
447 	sb->s_blocksize = 0;
448 	if (data->bsize)
449 		sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
450 	if (data->rsize)
451 		server->rsize = nfs_block_size(data->rsize, NULL);
452 	if (data->wsize)
453 		server->wsize = nfs_block_size(data->wsize, NULL);
454 	server->flags    = data->flags & NFS_MOUNT_FLAGMASK;
455 
456 	server->acregmin = data->acregmin*HZ;
457 	server->acregmax = data->acregmax*HZ;
458 	server->acdirmin = data->acdirmin*HZ;
459 	server->acdirmax = data->acdirmax*HZ;
460 
461 	/* Start lockd here, before we might error out */
462 	if (!(server->flags & NFS_MOUNT_NONLM))
463 		lockd_up();
464 
465 	server->namelen  = data->namlen;
466 	server->hostname = kmalloc(strlen(data->hostname) + 1, GFP_KERNEL);
467 	if (!server->hostname)
468 		return -ENOMEM;
469 	strcpy(server->hostname, data->hostname);
470 
471 	/* Check NFS protocol revision and initialize RPC op vector
472 	 * and file handle pool. */
473 #ifdef CONFIG_NFS_V3
474 	if (server->flags & NFS_MOUNT_VER3) {
475 		server->rpc_ops = &nfs_v3_clientops;
476 		server->caps |= NFS_CAP_READDIRPLUS;
477 	} else {
478 		server->rpc_ops = &nfs_v2_clientops;
479 	}
480 #else
481 	server->rpc_ops = &nfs_v2_clientops;
482 #endif
483 
484 	/* Fill in pseudoflavor for mount version < 5 */
485 	if (!(data->flags & NFS_MOUNT_SECFLAVOUR))
486 		data->pseudoflavor = RPC_AUTH_UNIX;
487 	authflavor = data->pseudoflavor;	/* save for sb_init() */
488 	/* XXX maybe we want to add a server->pseudoflavor field */
489 
490 	/* Create RPC client handles */
491 	server->client = nfs_create_client(server, data);
492 	if (IS_ERR(server->client))
493 		return PTR_ERR(server->client);
494 	/* RFC 2623, sec 2.3.2 */
495 	if (authflavor != RPC_AUTH_UNIX) {
496 		struct rpc_auth *auth;
497 
498 		server->client_sys = rpc_clone_client(server->client);
499 		if (IS_ERR(server->client_sys))
500 			return PTR_ERR(server->client_sys);
501 		auth = rpcauth_create(RPC_AUTH_UNIX, server->client_sys);
502 		if (IS_ERR(auth))
503 			return PTR_ERR(auth);
504 	} else {
505 		atomic_inc(&server->client->cl_count);
506 		server->client_sys = server->client;
507 	}
508 	if (server->flags & NFS_MOUNT_VER3) {
509 #ifdef CONFIG_NFS_V3_ACL
510 		if (!(server->flags & NFS_MOUNT_NOACL)) {
511 			server->client_acl = rpc_bind_new_program(server->client, &nfsacl_program, 3);
512 			/* No errors! Assume that Sun nfsacls are supported */
513 			if (!IS_ERR(server->client_acl))
514 				server->caps |= NFS_CAP_ACLS;
515 		}
516 #else
517 		server->flags &= ~NFS_MOUNT_NOACL;
518 #endif /* CONFIG_NFS_V3_ACL */
519 		/*
520 		 * The VFS shouldn't apply the umask to mode bits. We will
521 		 * do so ourselves when necessary.
522 		 */
523 		sb->s_flags |= MS_POSIXACL;
524 		if (server->namelen == 0 || server->namelen > NFS3_MAXNAMLEN)
525 			server->namelen = NFS3_MAXNAMLEN;
526 		sb->s_time_gran = 1;
527 	} else {
528 		if (server->namelen == 0 || server->namelen > NFS2_MAXNAMLEN)
529 			server->namelen = NFS2_MAXNAMLEN;
530 	}
531 
532 	sb->s_op = &nfs_sops;
533 	return nfs_sb_init(sb, authflavor);
534 }
535 
536 static int
537 nfs_statfs(struct super_block *sb, struct kstatfs *buf)
538 {
539 	struct nfs_server *server = NFS_SB(sb);
540 	unsigned char blockbits;
541 	unsigned long blockres;
542 	struct nfs_fh *rootfh = NFS_FH(sb->s_root->d_inode);
543 	struct nfs_fattr fattr;
544 	struct nfs_fsstat res = {
545 			.fattr = &fattr,
546 	};
547 	int error;
548 
549 	lock_kernel();
550 
551 	error = server->rpc_ops->statfs(server, rootfh, &res);
552 	buf->f_type = NFS_SUPER_MAGIC;
553 	if (error < 0)
554 		goto out_err;
555 
556 	/*
557 	 * Current versions of glibc do not correctly handle the
558 	 * case where f_frsize != f_bsize.  Eventually we want to
559 	 * report the value of wtmult in this field.
560 	 */
561 	buf->f_frsize = sb->s_blocksize;
562 
563 	/*
564 	 * On most *nix systems, f_blocks, f_bfree, and f_bavail
565 	 * are reported in units of f_frsize.  Linux hasn't had
566 	 * an f_frsize field in its statfs struct until recently,
567 	 * thus historically Linux's sys_statfs reports these
568 	 * fields in units of f_bsize.
569 	 */
570 	buf->f_bsize = sb->s_blocksize;
571 	blockbits = sb->s_blocksize_bits;
572 	blockres = (1 << blockbits) - 1;
573 	buf->f_blocks = (res.tbytes + blockres) >> blockbits;
574 	buf->f_bfree = (res.fbytes + blockres) >> blockbits;
575 	buf->f_bavail = (res.abytes + blockres) >> blockbits;
576 
577 	buf->f_files = res.tfiles;
578 	buf->f_ffree = res.afiles;
579 
580 	buf->f_namelen = server->namelen;
581  out:
582 	unlock_kernel();
583 	return 0;
584 
585  out_err:
586 	dprintk("%s: statfs error = %d\n", __FUNCTION__, -error);
587 	buf->f_bsize = buf->f_blocks = buf->f_bfree = buf->f_bavail = -1;
588 	goto out;
589 
590 }
591 
592 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss, int showdefaults)
593 {
594 	static struct proc_nfs_info {
595 		int flag;
596 		char *str;
597 		char *nostr;
598 	} nfs_info[] = {
599 		{ NFS_MOUNT_SOFT, ",soft", ",hard" },
600 		{ NFS_MOUNT_INTR, ",intr", "" },
601 		{ NFS_MOUNT_NOCTO, ",nocto", "" },
602 		{ NFS_MOUNT_NOAC, ",noac", "" },
603 		{ NFS_MOUNT_NONLM, ",nolock", "" },
604 		{ NFS_MOUNT_NOACL, ",noacl", "" },
605 		{ 0, NULL, NULL }
606 	};
607 	struct proc_nfs_info *nfs_infop;
608 	char buf[12];
609 	char *proto;
610 
611 	seq_printf(m, ",vers=%d", nfss->rpc_ops->version);
612 	seq_printf(m, ",rsize=%d", nfss->rsize);
613 	seq_printf(m, ",wsize=%d", nfss->wsize);
614 	if (nfss->acregmin != 3*HZ || showdefaults)
615 		seq_printf(m, ",acregmin=%d", nfss->acregmin/HZ);
616 	if (nfss->acregmax != 60*HZ || showdefaults)
617 		seq_printf(m, ",acregmax=%d", nfss->acregmax/HZ);
618 	if (nfss->acdirmin != 30*HZ || showdefaults)
619 		seq_printf(m, ",acdirmin=%d", nfss->acdirmin/HZ);
620 	if (nfss->acdirmax != 60*HZ || showdefaults)
621 		seq_printf(m, ",acdirmax=%d", nfss->acdirmax/HZ);
622 	for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
623 		if (nfss->flags & nfs_infop->flag)
624 			seq_puts(m, nfs_infop->str);
625 		else
626 			seq_puts(m, nfs_infop->nostr);
627 	}
628 	switch (nfss->client->cl_xprt->prot) {
629 		case IPPROTO_TCP:
630 			proto = "tcp";
631 			break;
632 		case IPPROTO_UDP:
633 			proto = "udp";
634 			break;
635 		default:
636 			snprintf(buf, sizeof(buf), "%u", nfss->client->cl_xprt->prot);
637 			proto = buf;
638 	}
639 	seq_printf(m, ",proto=%s", proto);
640 	seq_printf(m, ",timeo=%lu", 10U * nfss->retrans_timeo / HZ);
641 	seq_printf(m, ",retrans=%u", nfss->retrans_count);
642 }
643 
644 static int nfs_show_options(struct seq_file *m, struct vfsmount *mnt)
645 {
646 	struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
647 
648 	nfs_show_mount_options(m, nfss, 0);
649 
650 	seq_puts(m, ",addr=");
651 	seq_escape(m, nfss->hostname, " \t\n\\");
652 
653 	return 0;
654 }
655 
656 static int nfs_show_stats(struct seq_file *m, struct vfsmount *mnt)
657 {
658 	int i, cpu;
659 	struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
660 	struct rpc_auth *auth = nfss->client->cl_auth;
661 	struct nfs_iostats totals = { };
662 
663 	seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
664 
665 	/*
666 	 * Display all mount option settings
667 	 */
668 	seq_printf(m, "\n\topts:\t");
669 	seq_puts(m, mnt->mnt_sb->s_flags & MS_RDONLY ? "ro" : "rw");
670 	seq_puts(m, mnt->mnt_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
671 	seq_puts(m, mnt->mnt_sb->s_flags & MS_NOATIME ? ",noatime" : "");
672 	seq_puts(m, mnt->mnt_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
673 	nfs_show_mount_options(m, nfss, 1);
674 
675 	seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
676 
677 	seq_printf(m, "\n\tcaps:\t");
678 	seq_printf(m, "caps=0x%x", nfss->caps);
679 	seq_printf(m, ",wtmult=%d", nfss->wtmult);
680 	seq_printf(m, ",dtsize=%d", nfss->dtsize);
681 	seq_printf(m, ",bsize=%d", nfss->bsize);
682 	seq_printf(m, ",namelen=%d", nfss->namelen);
683 
684 #ifdef CONFIG_NFS_V4
685 	if (nfss->rpc_ops->version == 4) {
686 		seq_printf(m, "\n\tnfsv4:\t");
687 		seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
688 		seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
689 		seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
690 	}
691 #endif
692 
693 	/*
694 	 * Display security flavor in effect for this mount
695 	 */
696 	seq_printf(m, "\n\tsec:\tflavor=%d", auth->au_ops->au_flavor);
697 	if (auth->au_flavor)
698 		seq_printf(m, ",pseudoflavor=%d", auth->au_flavor);
699 
700 	/*
701 	 * Display superblock I/O counters
702 	 */
703 	for (cpu = 0; cpu < NR_CPUS; cpu++) {
704 		struct nfs_iostats *stats;
705 
706 		if (!cpu_possible(cpu))
707 			continue;
708 
709 		preempt_disable();
710 		stats = per_cpu_ptr(nfss->io_stats, cpu);
711 
712 		for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
713 			totals.events[i] += stats->events[i];
714 		for (i = 0; i < __NFSIOS_BYTESMAX; i++)
715 			totals.bytes[i] += stats->bytes[i];
716 
717 		preempt_enable();
718 	}
719 
720 	seq_printf(m, "\n\tevents:\t");
721 	for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
722 		seq_printf(m, "%lu ", totals.events[i]);
723 	seq_printf(m, "\n\tbytes:\t");
724 	for (i = 0; i < __NFSIOS_BYTESMAX; i++)
725 		seq_printf(m, "%Lu ", totals.bytes[i]);
726 	seq_printf(m, "\n");
727 
728 	rpc_print_iostats(m, nfss->client);
729 
730 	return 0;
731 }
732 
733 /**
734  * nfs_sync_mapping - helper to flush all mmapped dirty data to disk
735  */
736 int nfs_sync_mapping(struct address_space *mapping)
737 {
738 	int ret;
739 
740 	if (mapping->nrpages == 0)
741 		return 0;
742 	unmap_mapping_range(mapping, 0, 0, 0);
743 	ret = filemap_write_and_wait(mapping);
744 	if (ret != 0)
745 		goto out;
746 	ret = nfs_wb_all(mapping->host);
747 out:
748 	return ret;
749 }
750 
751 /*
752  * Invalidate the local caches
753  */
754 static void nfs_zap_caches_locked(struct inode *inode)
755 {
756 	struct nfs_inode *nfsi = NFS_I(inode);
757 	int mode = inode->i_mode;
758 
759 	nfs_inc_stats(inode, NFSIOS_ATTRINVALIDATE);
760 
761 	NFS_ATTRTIMEO(inode) = NFS_MINATTRTIMEO(inode);
762 	NFS_ATTRTIMEO_UPDATE(inode) = jiffies;
763 
764 	memset(NFS_COOKIEVERF(inode), 0, sizeof(NFS_COOKIEVERF(inode)));
765 	if (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))
766 		nfsi->cache_validity |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL|NFS_INO_REVAL_PAGECACHE;
767 	else
768 		nfsi->cache_validity |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL|NFS_INO_REVAL_PAGECACHE;
769 }
770 
771 void nfs_zap_caches(struct inode *inode)
772 {
773 	spin_lock(&inode->i_lock);
774 	nfs_zap_caches_locked(inode);
775 	spin_unlock(&inode->i_lock);
776 }
777 
778 static void nfs_zap_acl_cache(struct inode *inode)
779 {
780 	void (*clear_acl_cache)(struct inode *);
781 
782 	clear_acl_cache = NFS_PROTO(inode)->clear_acl_cache;
783 	if (clear_acl_cache != NULL)
784 		clear_acl_cache(inode);
785 	spin_lock(&inode->i_lock);
786 	NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_ACL;
787 	spin_unlock(&inode->i_lock);
788 }
789 
790 /*
791  * Invalidate, but do not unhash, the inode.
792  * NB: must be called with inode->i_lock held!
793  */
794 static void nfs_invalidate_inode(struct inode *inode)
795 {
796 	set_bit(NFS_INO_STALE, &NFS_FLAGS(inode));
797 	nfs_zap_caches_locked(inode);
798 }
799 
800 struct nfs_find_desc {
801 	struct nfs_fh		*fh;
802 	struct nfs_fattr	*fattr;
803 };
804 
805 /*
806  * In NFSv3 we can have 64bit inode numbers. In order to support
807  * this, and re-exported directories (also seen in NFSv2)
808  * we are forced to allow 2 different inodes to have the same
809  * i_ino.
810  */
811 static int
812 nfs_find_actor(struct inode *inode, void *opaque)
813 {
814 	struct nfs_find_desc	*desc = (struct nfs_find_desc *)opaque;
815 	struct nfs_fh		*fh = desc->fh;
816 	struct nfs_fattr	*fattr = desc->fattr;
817 
818 	if (NFS_FILEID(inode) != fattr->fileid)
819 		return 0;
820 	if (nfs_compare_fh(NFS_FH(inode), fh))
821 		return 0;
822 	if (is_bad_inode(inode) || NFS_STALE(inode))
823 		return 0;
824 	return 1;
825 }
826 
827 static int
828 nfs_init_locked(struct inode *inode, void *opaque)
829 {
830 	struct nfs_find_desc	*desc = (struct nfs_find_desc *)opaque;
831 	struct nfs_fattr	*fattr = desc->fattr;
832 
833 	NFS_FILEID(inode) = fattr->fileid;
834 	nfs_copy_fh(NFS_FH(inode), desc->fh);
835 	return 0;
836 }
837 
838 /* Don't use READDIRPLUS on directories that we believe are too large */
839 #define NFS_LIMIT_READDIRPLUS (8*PAGE_SIZE)
840 
841 /*
842  * This is our front-end to iget that looks up inodes by file handle
843  * instead of inode number.
844  */
845 struct inode *
846 nfs_fhget(struct super_block *sb, struct nfs_fh *fh, struct nfs_fattr *fattr)
847 {
848 	struct nfs_find_desc desc = {
849 		.fh	= fh,
850 		.fattr	= fattr
851 	};
852 	struct inode *inode = ERR_PTR(-ENOENT);
853 	unsigned long hash;
854 
855 	if ((fattr->valid & NFS_ATTR_FATTR) == 0)
856 		goto out_no_inode;
857 
858 	if (!fattr->nlink) {
859 		printk("NFS: Buggy server - nlink == 0!\n");
860 		goto out_no_inode;
861 	}
862 
863 	hash = nfs_fattr_to_ino_t(fattr);
864 
865 	inode = iget5_locked(sb, hash, nfs_find_actor, nfs_init_locked, &desc);
866 	if (inode == NULL) {
867 		inode = ERR_PTR(-ENOMEM);
868 		goto out_no_inode;
869 	}
870 
871 	if (inode->i_state & I_NEW) {
872 		struct nfs_inode *nfsi = NFS_I(inode);
873 
874 		/* We set i_ino for the few things that still rely on it,
875 		 * such as stat(2) */
876 		inode->i_ino = hash;
877 
878 		/* We can't support update_atime(), since the server will reset it */
879 		inode->i_flags |= S_NOATIME|S_NOCMTIME;
880 		inode->i_mode = fattr->mode;
881 		/* Why so? Because we want revalidate for devices/FIFOs, and
882 		 * that's precisely what we have in nfs_file_inode_operations.
883 		 */
884 		inode->i_op = NFS_SB(sb)->rpc_ops->file_inode_ops;
885 		if (S_ISREG(inode->i_mode)) {
886 			inode->i_fop = &nfs_file_operations;
887 			inode->i_data.a_ops = &nfs_file_aops;
888 			inode->i_data.backing_dev_info = &NFS_SB(sb)->backing_dev_info;
889 		} else if (S_ISDIR(inode->i_mode)) {
890 			inode->i_op = NFS_SB(sb)->rpc_ops->dir_inode_ops;
891 			inode->i_fop = &nfs_dir_operations;
892 			if (nfs_server_capable(inode, NFS_CAP_READDIRPLUS)
893 			    && fattr->size <= NFS_LIMIT_READDIRPLUS)
894 				set_bit(NFS_INO_ADVISE_RDPLUS, &NFS_FLAGS(inode));
895 		} else if (S_ISLNK(inode->i_mode))
896 			inode->i_op = &nfs_symlink_inode_operations;
897 		else
898 			init_special_inode(inode, inode->i_mode, fattr->rdev);
899 
900 		nfsi->read_cache_jiffies = fattr->time_start;
901 		nfsi->last_updated = jiffies;
902 		inode->i_atime = fattr->atime;
903 		inode->i_mtime = fattr->mtime;
904 		inode->i_ctime = fattr->ctime;
905 		if (fattr->valid & NFS_ATTR_FATTR_V4)
906 			nfsi->change_attr = fattr->change_attr;
907 		inode->i_size = nfs_size_to_loff_t(fattr->size);
908 		inode->i_nlink = fattr->nlink;
909 		inode->i_uid = fattr->uid;
910 		inode->i_gid = fattr->gid;
911 		if (fattr->valid & (NFS_ATTR_FATTR_V3 | NFS_ATTR_FATTR_V4)) {
912 			/*
913 			 * report the blocks in 512byte units
914 			 */
915 			inode->i_blocks = nfs_calc_block_size(fattr->du.nfs3.used);
916 			inode->i_blksize = inode->i_sb->s_blocksize;
917 		} else {
918 			inode->i_blocks = fattr->du.nfs2.blocks;
919 			inode->i_blksize = fattr->du.nfs2.blocksize;
920 		}
921 		nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
922 		nfsi->attrtimeo_timestamp = jiffies;
923 		memset(nfsi->cookieverf, 0, sizeof(nfsi->cookieverf));
924 		nfsi->cache_access.cred = NULL;
925 
926 		unlock_new_inode(inode);
927 	} else
928 		nfs_refresh_inode(inode, fattr);
929 	dprintk("NFS: nfs_fhget(%s/%Ld ct=%d)\n",
930 		inode->i_sb->s_id,
931 		(long long)NFS_FILEID(inode),
932 		atomic_read(&inode->i_count));
933 
934 out:
935 	return inode;
936 
937 out_no_inode:
938 	dprintk("nfs_fhget: iget failed with error %ld\n", PTR_ERR(inode));
939 	goto out;
940 }
941 
942 #define NFS_VALID_ATTRS (ATTR_MODE|ATTR_UID|ATTR_GID|ATTR_SIZE|ATTR_ATIME|ATTR_ATIME_SET|ATTR_MTIME|ATTR_MTIME_SET)
943 
944 int
945 nfs_setattr(struct dentry *dentry, struct iattr *attr)
946 {
947 	struct inode *inode = dentry->d_inode;
948 	struct nfs_fattr fattr;
949 	int error;
950 
951 	nfs_inc_stats(inode, NFSIOS_VFSSETATTR);
952 
953 	if (attr->ia_valid & ATTR_SIZE) {
954 		if (!S_ISREG(inode->i_mode) || attr->ia_size == i_size_read(inode))
955 			attr->ia_valid &= ~ATTR_SIZE;
956 	}
957 
958 	/* Optimization: if the end result is no change, don't RPC */
959 	attr->ia_valid &= NFS_VALID_ATTRS;
960 	if (attr->ia_valid == 0)
961 		return 0;
962 
963 	lock_kernel();
964 	nfs_begin_data_update(inode);
965 	/* Write all dirty data */
966 	filemap_write_and_wait(inode->i_mapping);
967 	nfs_wb_all(inode);
968 	/*
969 	 * Return any delegations if we're going to change ACLs
970 	 */
971 	if ((attr->ia_valid & (ATTR_MODE|ATTR_UID|ATTR_GID)) != 0)
972 		nfs_inode_return_delegation(inode);
973 	error = NFS_PROTO(inode)->setattr(dentry, &fattr, attr);
974 	if (error == 0)
975 		nfs_refresh_inode(inode, &fattr);
976 	nfs_end_data_update(inode);
977 	unlock_kernel();
978 	return error;
979 }
980 
981 /**
982  * nfs_setattr_update_inode - Update inode metadata after a setattr call.
983  * @inode: pointer to struct inode
984  * @attr: pointer to struct iattr
985  *
986  * Note: we do this in the *proc.c in order to ensure that
987  *       it works for things like exclusive creates too.
988  */
989 void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr)
990 {
991 	if ((attr->ia_valid & (ATTR_MODE|ATTR_UID|ATTR_GID)) != 0) {
992 		if ((attr->ia_valid & ATTR_MODE) != 0) {
993 			int mode = attr->ia_mode & S_IALLUGO;
994 			mode |= inode->i_mode & ~S_IALLUGO;
995 			inode->i_mode = mode;
996 		}
997 		if ((attr->ia_valid & ATTR_UID) != 0)
998 			inode->i_uid = attr->ia_uid;
999 		if ((attr->ia_valid & ATTR_GID) != 0)
1000 			inode->i_gid = attr->ia_gid;
1001 		spin_lock(&inode->i_lock);
1002 		NFS_I(inode)->cache_validity |= NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1003 		spin_unlock(&inode->i_lock);
1004 	}
1005 	if ((attr->ia_valid & ATTR_SIZE) != 0) {
1006 		nfs_inc_stats(inode, NFSIOS_SETATTRTRUNC);
1007 		inode->i_size = attr->ia_size;
1008 		vmtruncate(inode, attr->ia_size);
1009 	}
1010 }
1011 
1012 static int nfs_wait_schedule(void *word)
1013 {
1014 	if (signal_pending(current))
1015 		return -ERESTARTSYS;
1016 	schedule();
1017 	return 0;
1018 }
1019 
1020 /*
1021  * Wait for the inode to get unlocked.
1022  */
1023 static int nfs_wait_on_inode(struct inode *inode)
1024 {
1025 	struct rpc_clnt	*clnt = NFS_CLIENT(inode);
1026 	struct nfs_inode *nfsi = NFS_I(inode);
1027 	sigset_t oldmask;
1028 	int error;
1029 
1030 	rpc_clnt_sigmask(clnt, &oldmask);
1031 	error = wait_on_bit_lock(&nfsi->flags, NFS_INO_REVALIDATING,
1032 					nfs_wait_schedule, TASK_INTERRUPTIBLE);
1033 	rpc_clnt_sigunmask(clnt, &oldmask);
1034 
1035 	return error;
1036 }
1037 
1038 static void nfs_wake_up_inode(struct inode *inode)
1039 {
1040 	struct nfs_inode *nfsi = NFS_I(inode);
1041 
1042 	clear_bit(NFS_INO_REVALIDATING, &nfsi->flags);
1043 	smp_mb__after_clear_bit();
1044 	wake_up_bit(&nfsi->flags, NFS_INO_REVALIDATING);
1045 }
1046 
1047 int nfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
1048 {
1049 	struct inode *inode = dentry->d_inode;
1050 	int need_atime = NFS_I(inode)->cache_validity & NFS_INO_INVALID_ATIME;
1051 	int err;
1052 
1053 	/* Flush out writes to the server in order to update c/mtime */
1054 	nfs_sync_inode_wait(inode, 0, 0, FLUSH_NOCOMMIT);
1055 
1056 	/*
1057 	 * We may force a getattr if the user cares about atime.
1058 	 *
1059 	 * Note that we only have to check the vfsmount flags here:
1060 	 *  - NFS always sets S_NOATIME by so checking it would give a
1061 	 *    bogus result
1062 	 *  - NFS never sets MS_NOATIME or MS_NODIRATIME so there is
1063 	 *    no point in checking those.
1064 	 */
1065  	if ((mnt->mnt_flags & MNT_NOATIME) ||
1066  	    ((mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode)))
1067 		need_atime = 0;
1068 
1069 	if (need_atime)
1070 		err = __nfs_revalidate_inode(NFS_SERVER(inode), inode);
1071 	else
1072 		err = nfs_revalidate_inode(NFS_SERVER(inode), inode);
1073 	if (!err)
1074 		generic_fillattr(inode, stat);
1075 	return err;
1076 }
1077 
1078 static struct nfs_open_context *alloc_nfs_open_context(struct vfsmount *mnt, struct dentry *dentry, struct rpc_cred *cred)
1079 {
1080 	struct nfs_open_context *ctx;
1081 
1082 	ctx = (struct nfs_open_context *)kmalloc(sizeof(*ctx), GFP_KERNEL);
1083 	if (ctx != NULL) {
1084 		atomic_set(&ctx->count, 1);
1085 		ctx->dentry = dget(dentry);
1086 		ctx->vfsmnt = mntget(mnt);
1087 		ctx->cred = get_rpccred(cred);
1088 		ctx->state = NULL;
1089 		ctx->lockowner = current->files;
1090 		ctx->error = 0;
1091 		ctx->dir_cookie = 0;
1092 	}
1093 	return ctx;
1094 }
1095 
1096 struct nfs_open_context *get_nfs_open_context(struct nfs_open_context *ctx)
1097 {
1098 	if (ctx != NULL)
1099 		atomic_inc(&ctx->count);
1100 	return ctx;
1101 }
1102 
1103 void put_nfs_open_context(struct nfs_open_context *ctx)
1104 {
1105 	if (atomic_dec_and_test(&ctx->count)) {
1106 		if (!list_empty(&ctx->list)) {
1107 			struct inode *inode = ctx->dentry->d_inode;
1108 			spin_lock(&inode->i_lock);
1109 			list_del(&ctx->list);
1110 			spin_unlock(&inode->i_lock);
1111 		}
1112 		if (ctx->state != NULL)
1113 			nfs4_close_state(ctx->state, ctx->mode);
1114 		if (ctx->cred != NULL)
1115 			put_rpccred(ctx->cred);
1116 		dput(ctx->dentry);
1117 		mntput(ctx->vfsmnt);
1118 		kfree(ctx);
1119 	}
1120 }
1121 
1122 /*
1123  * Ensure that mmap has a recent RPC credential for use when writing out
1124  * shared pages
1125  */
1126 static void nfs_file_set_open_context(struct file *filp, struct nfs_open_context *ctx)
1127 {
1128 	struct inode *inode = filp->f_dentry->d_inode;
1129 	struct nfs_inode *nfsi = NFS_I(inode);
1130 
1131 	filp->private_data = get_nfs_open_context(ctx);
1132 	spin_lock(&inode->i_lock);
1133 	list_add(&ctx->list, &nfsi->open_files);
1134 	spin_unlock(&inode->i_lock);
1135 }
1136 
1137 /*
1138  * Given an inode, search for an open context with the desired characteristics
1139  */
1140 struct nfs_open_context *nfs_find_open_context(struct inode *inode, struct rpc_cred *cred, int mode)
1141 {
1142 	struct nfs_inode *nfsi = NFS_I(inode);
1143 	struct nfs_open_context *pos, *ctx = NULL;
1144 
1145 	spin_lock(&inode->i_lock);
1146 	list_for_each_entry(pos, &nfsi->open_files, list) {
1147 		if (cred != NULL && pos->cred != cred)
1148 			continue;
1149 		if ((pos->mode & mode) == mode) {
1150 			ctx = get_nfs_open_context(pos);
1151 			break;
1152 		}
1153 	}
1154 	spin_unlock(&inode->i_lock);
1155 	return ctx;
1156 }
1157 
1158 static void nfs_file_clear_open_context(struct file *filp)
1159 {
1160 	struct inode *inode = filp->f_dentry->d_inode;
1161 	struct nfs_open_context *ctx = (struct nfs_open_context *)filp->private_data;
1162 
1163 	if (ctx) {
1164 		filp->private_data = NULL;
1165 		spin_lock(&inode->i_lock);
1166 		list_move_tail(&ctx->list, &NFS_I(inode)->open_files);
1167 		spin_unlock(&inode->i_lock);
1168 		put_nfs_open_context(ctx);
1169 	}
1170 }
1171 
1172 /*
1173  * These allocate and release file read/write context information.
1174  */
1175 int nfs_open(struct inode *inode, struct file *filp)
1176 {
1177 	struct nfs_open_context *ctx;
1178 	struct rpc_cred *cred;
1179 
1180 	cred = rpcauth_lookupcred(NFS_CLIENT(inode)->cl_auth, 0);
1181 	if (IS_ERR(cred))
1182 		return PTR_ERR(cred);
1183 	ctx = alloc_nfs_open_context(filp->f_vfsmnt, filp->f_dentry, cred);
1184 	put_rpccred(cred);
1185 	if (ctx == NULL)
1186 		return -ENOMEM;
1187 	ctx->mode = filp->f_mode;
1188 	nfs_file_set_open_context(filp, ctx);
1189 	put_nfs_open_context(ctx);
1190 	return 0;
1191 }
1192 
1193 int nfs_release(struct inode *inode, struct file *filp)
1194 {
1195 	nfs_file_clear_open_context(filp);
1196 	return 0;
1197 }
1198 
1199 /*
1200  * This function is called whenever some part of NFS notices that
1201  * the cached attributes have to be refreshed.
1202  */
1203 int
1204 __nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
1205 {
1206 	int		 status = -ESTALE;
1207 	struct nfs_fattr fattr;
1208 	struct nfs_inode *nfsi = NFS_I(inode);
1209 
1210 	dfprintk(PAGECACHE, "NFS: revalidating (%s/%Ld)\n",
1211 		inode->i_sb->s_id, (long long)NFS_FILEID(inode));
1212 
1213 	lock_kernel();
1214 	if (!inode || is_bad_inode(inode))
1215  		goto out_nowait;
1216 	if (NFS_STALE(inode))
1217  		goto out_nowait;
1218 
1219 	status = nfs_wait_on_inode(inode);
1220 	if (status < 0)
1221 		goto out;
1222 	if (NFS_STALE(inode)) {
1223 		status = -ESTALE;
1224 		/* Do we trust the cached ESTALE? */
1225 		if (NFS_ATTRTIMEO(inode) != 0) {
1226 			if (nfsi->cache_validity & (NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA|NFS_INO_INVALID_ATIME)) {
1227 				/* no */
1228 			} else
1229 				goto out;
1230 		}
1231 	}
1232 
1233 	status = NFS_PROTO(inode)->getattr(server, NFS_FH(inode), &fattr);
1234 	if (status != 0) {
1235 		dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Ld) getattr failed, error=%d\n",
1236 			 inode->i_sb->s_id,
1237 			 (long long)NFS_FILEID(inode), status);
1238 		if (status == -ESTALE) {
1239 			nfs_zap_caches(inode);
1240 			if (!S_ISDIR(inode->i_mode))
1241 				set_bit(NFS_INO_STALE, &NFS_FLAGS(inode));
1242 		}
1243 		goto out;
1244 	}
1245 
1246 	spin_lock(&inode->i_lock);
1247 	status = nfs_update_inode(inode, &fattr);
1248 	if (status) {
1249 		spin_unlock(&inode->i_lock);
1250 		dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Ld) refresh failed, error=%d\n",
1251 			 inode->i_sb->s_id,
1252 			 (long long)NFS_FILEID(inode), status);
1253 		goto out;
1254 	}
1255 	spin_unlock(&inode->i_lock);
1256 
1257 	nfs_revalidate_mapping(inode, inode->i_mapping);
1258 
1259 	if (nfsi->cache_validity & NFS_INO_INVALID_ACL)
1260 		nfs_zap_acl_cache(inode);
1261 
1262 	dfprintk(PAGECACHE, "NFS: (%s/%Ld) revalidation complete\n",
1263 		inode->i_sb->s_id,
1264 		(long long)NFS_FILEID(inode));
1265 
1266  out:
1267 	nfs_wake_up_inode(inode);
1268 
1269  out_nowait:
1270 	unlock_kernel();
1271 	return status;
1272 }
1273 
1274 int nfs_attribute_timeout(struct inode *inode)
1275 {
1276 	struct nfs_inode *nfsi = NFS_I(inode);
1277 
1278 	if (nfs_have_delegation(inode, FMODE_READ))
1279 		return 0;
1280 	return time_after(jiffies, nfsi->read_cache_jiffies+nfsi->attrtimeo);
1281 }
1282 
1283 /**
1284  * nfs_revalidate_inode - Revalidate the inode attributes
1285  * @server - pointer to nfs_server struct
1286  * @inode - pointer to inode struct
1287  *
1288  * Updates inode attribute information by retrieving the data from the server.
1289  */
1290 int nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
1291 {
1292 	nfs_inc_stats(inode, NFSIOS_INODEREVALIDATE);
1293 	if (!(NFS_I(inode)->cache_validity & (NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA))
1294 			&& !nfs_attribute_timeout(inode))
1295 		return NFS_STALE(inode) ? -ESTALE : 0;
1296 	return __nfs_revalidate_inode(server, inode);
1297 }
1298 
1299 /**
1300  * nfs_revalidate_mapping - Revalidate the pagecache
1301  * @inode - pointer to host inode
1302  * @mapping - pointer to mapping
1303  */
1304 void nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping)
1305 {
1306 	struct nfs_inode *nfsi = NFS_I(inode);
1307 
1308 	if (nfsi->cache_validity & NFS_INO_INVALID_DATA) {
1309 		nfs_inc_stats(inode, NFSIOS_DATAINVALIDATE);
1310 		if (S_ISREG(inode->i_mode))
1311 			nfs_sync_mapping(mapping);
1312 		invalidate_inode_pages2(mapping);
1313 
1314 		spin_lock(&inode->i_lock);
1315 		nfsi->cache_validity &= ~NFS_INO_INVALID_DATA;
1316 		if (S_ISDIR(inode->i_mode)) {
1317 			memset(nfsi->cookieverf, 0, sizeof(nfsi->cookieverf));
1318 			/* This ensures we revalidate child dentries */
1319 			nfsi->cache_change_attribute = jiffies;
1320 		}
1321 		spin_unlock(&inode->i_lock);
1322 
1323 		dfprintk(PAGECACHE, "NFS: (%s/%Ld) data cache invalidated\n",
1324 				inode->i_sb->s_id,
1325 				(long long)NFS_FILEID(inode));
1326 	}
1327 }
1328 
1329 /**
1330  * nfs_begin_data_update
1331  * @inode - pointer to inode
1332  * Declare that a set of operations will update file data on the server
1333  */
1334 void nfs_begin_data_update(struct inode *inode)
1335 {
1336 	atomic_inc(&NFS_I(inode)->data_updates);
1337 }
1338 
1339 /**
1340  * nfs_end_data_update
1341  * @inode - pointer to inode
1342  * Declare end of the operations that will update file data
1343  * This will mark the inode as immediately needing revalidation
1344  * of its attribute cache.
1345  */
1346 void nfs_end_data_update(struct inode *inode)
1347 {
1348 	struct nfs_inode *nfsi = NFS_I(inode);
1349 
1350 	if (!nfs_have_delegation(inode, FMODE_READ)) {
1351 		/* Directories and symlinks: invalidate page cache */
1352 		if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) {
1353 			spin_lock(&inode->i_lock);
1354 			nfsi->cache_validity |= NFS_INO_INVALID_DATA;
1355 			spin_unlock(&inode->i_lock);
1356 		}
1357 	}
1358 	nfsi->cache_change_attribute = jiffies;
1359 	atomic_dec(&nfsi->data_updates);
1360 }
1361 
1362 static void nfs_wcc_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1363 {
1364 	struct nfs_inode *nfsi = NFS_I(inode);
1365 
1366 	if ((fattr->valid & NFS_ATTR_PRE_CHANGE) != 0
1367 			&& nfsi->change_attr == fattr->pre_change_attr) {
1368 		nfsi->change_attr = fattr->change_attr;
1369 		nfsi->cache_change_attribute = jiffies;
1370 	}
1371 
1372 	/* If we have atomic WCC data, we may update some attributes */
1373 	if ((fattr->valid & NFS_ATTR_WCC) != 0) {
1374 		if (timespec_equal(&inode->i_ctime, &fattr->pre_ctime)) {
1375 			memcpy(&inode->i_ctime, &fattr->ctime, sizeof(inode->i_ctime));
1376 			nfsi->cache_change_attribute = jiffies;
1377 		}
1378 		if (timespec_equal(&inode->i_mtime, &fattr->pre_mtime)) {
1379 			memcpy(&inode->i_mtime, &fattr->mtime, sizeof(inode->i_mtime));
1380 			nfsi->cache_change_attribute = jiffies;
1381 		}
1382 		if (inode->i_size == fattr->pre_size && nfsi->npages == 0) {
1383 			inode->i_size = fattr->size;
1384 			nfsi->cache_change_attribute = jiffies;
1385 		}
1386 	}
1387 }
1388 
1389 /**
1390  * nfs_check_inode_attributes - verify consistency of the inode attribute cache
1391  * @inode - pointer to inode
1392  * @fattr - updated attributes
1393  *
1394  * Verifies the attribute cache. If we have just changed the attributes,
1395  * so that fattr carries weak cache consistency data, then it may
1396  * also update the ctime/mtime/change_attribute.
1397  */
1398 static int nfs_check_inode_attributes(struct inode *inode, struct nfs_fattr *fattr)
1399 {
1400 	struct nfs_inode *nfsi = NFS_I(inode);
1401 	loff_t cur_size, new_isize;
1402 	int data_unstable;
1403 
1404 
1405 	if ((fattr->valid & NFS_ATTR_FATTR) == 0)
1406 		return 0;
1407 
1408 	/* Has the inode gone and changed behind our back? */
1409 	if (nfsi->fileid != fattr->fileid
1410 			|| (inode->i_mode & S_IFMT) != (fattr->mode & S_IFMT)) {
1411 		return -EIO;
1412 	}
1413 
1414 	/* Are we in the process of updating data on the server? */
1415 	data_unstable = nfs_caches_unstable(inode);
1416 
1417 	/* Do atomic weak cache consistency updates */
1418 	nfs_wcc_update_inode(inode, fattr);
1419 
1420 	if ((fattr->valid & NFS_ATTR_FATTR_V4) != 0) {
1421 		if (nfsi->change_attr == fattr->change_attr)
1422 			goto out;
1423 		nfsi->cache_validity |= NFS_INO_INVALID_ATTR;
1424 		if (!data_unstable)
1425 			nfsi->cache_validity |= NFS_INO_REVAL_PAGECACHE;
1426 	}
1427 
1428 	/* Verify a few of the more important attributes */
1429 	if (!timespec_equal(&inode->i_mtime, &fattr->mtime)) {
1430 		nfsi->cache_validity |= NFS_INO_INVALID_ATTR;
1431 		if (!data_unstable)
1432 			nfsi->cache_validity |= NFS_INO_REVAL_PAGECACHE;
1433 	}
1434 
1435 	cur_size = i_size_read(inode);
1436  	new_isize = nfs_size_to_loff_t(fattr->size);
1437 	if (cur_size != new_isize && nfsi->npages == 0)
1438 		nfsi->cache_validity |= NFS_INO_INVALID_ATTR|NFS_INO_REVAL_PAGECACHE;
1439 
1440 	/* Have any file permissions changed? */
1441 	if ((inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO)
1442 			|| inode->i_uid != fattr->uid
1443 			|| inode->i_gid != fattr->gid)
1444 		nfsi->cache_validity |= NFS_INO_INVALID_ATTR | NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL;
1445 
1446 	/* Has the link count changed? */
1447 	if (inode->i_nlink != fattr->nlink)
1448 		nfsi->cache_validity |= NFS_INO_INVALID_ATTR;
1449 
1450 out:
1451 	if (!timespec_equal(&inode->i_atime, &fattr->atime))
1452 		nfsi->cache_validity |= NFS_INO_INVALID_ATIME;
1453 
1454 	nfsi->read_cache_jiffies = fattr->time_start;
1455 	return 0;
1456 }
1457 
1458 /**
1459  * nfs_refresh_inode - try to update the inode attribute cache
1460  * @inode - pointer to inode
1461  * @fattr - updated attributes
1462  *
1463  * Check that an RPC call that returned attributes has not overlapped with
1464  * other recent updates of the inode metadata, then decide whether it is
1465  * safe to do a full update of the inode attributes, or whether just to
1466  * call nfs_check_inode_attributes.
1467  */
1468 int nfs_refresh_inode(struct inode *inode, struct nfs_fattr *fattr)
1469 {
1470 	struct nfs_inode *nfsi = NFS_I(inode);
1471 	int status;
1472 
1473 	if ((fattr->valid & NFS_ATTR_FATTR) == 0)
1474 		return 0;
1475 	spin_lock(&inode->i_lock);
1476 	nfsi->cache_validity &= ~NFS_INO_REVAL_PAGECACHE;
1477 	if (time_after(fattr->time_start, nfsi->last_updated))
1478 		status = nfs_update_inode(inode, fattr);
1479 	else
1480 		status = nfs_check_inode_attributes(inode, fattr);
1481 
1482 	spin_unlock(&inode->i_lock);
1483 	return status;
1484 }
1485 
1486 /**
1487  * nfs_post_op_update_inode - try to update the inode attribute cache
1488  * @inode - pointer to inode
1489  * @fattr - updated attributes
1490  *
1491  * After an operation that has changed the inode metadata, mark the
1492  * attribute cache as being invalid, then try to update it.
1493  */
1494 int nfs_post_op_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1495 {
1496 	struct nfs_inode *nfsi = NFS_I(inode);
1497 	int status = 0;
1498 
1499 	spin_lock(&inode->i_lock);
1500 	if (unlikely((fattr->valid & NFS_ATTR_FATTR) == 0)) {
1501 		nfsi->cache_validity |= NFS_INO_INVALID_ATTR | NFS_INO_INVALID_ACCESS;
1502 		goto out;
1503 	}
1504 	status = nfs_update_inode(inode, fattr);
1505 out:
1506 	spin_unlock(&inode->i_lock);
1507 	return status;
1508 }
1509 
1510 /*
1511  * Many nfs protocol calls return the new file attributes after
1512  * an operation.  Here we update the inode to reflect the state
1513  * of the server's inode.
1514  *
1515  * This is a bit tricky because we have to make sure all dirty pages
1516  * have been sent off to the server before calling invalidate_inode_pages.
1517  * To make sure no other process adds more write requests while we try
1518  * our best to flush them, we make them sleep during the attribute refresh.
1519  *
1520  * A very similar scenario holds for the dir cache.
1521  */
1522 static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1523 {
1524 	struct nfs_inode *nfsi = NFS_I(inode);
1525 	loff_t cur_isize, new_isize;
1526 	unsigned int	invalid = 0;
1527 	int data_stable;
1528 
1529 	dfprintk(VFS, "NFS: %s(%s/%ld ct=%d info=0x%x)\n",
1530 			__FUNCTION__, inode->i_sb->s_id, inode->i_ino,
1531 			atomic_read(&inode->i_count), fattr->valid);
1532 
1533 	if ((fattr->valid & NFS_ATTR_FATTR) == 0)
1534 		return 0;
1535 
1536 	if (nfsi->fileid != fattr->fileid)
1537 		goto out_fileid;
1538 
1539 	/*
1540 	 * Make sure the inode's type hasn't changed.
1541 	 */
1542 	if ((inode->i_mode & S_IFMT) != (fattr->mode & S_IFMT))
1543 		goto out_changed;
1544 
1545 	/*
1546 	 * Update the read time so we don't revalidate too often.
1547 	 */
1548 	nfsi->read_cache_jiffies = fattr->time_start;
1549 	nfsi->last_updated = jiffies;
1550 
1551 	/* Are we racing with known updates of the metadata on the server? */
1552 	data_stable = nfs_verify_change_attribute(inode, fattr->time_start);
1553 	if (data_stable)
1554 		nfsi->cache_validity &= ~(NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ATIME);
1555 
1556 	/* Do atomic weak cache consistency updates */
1557 	nfs_wcc_update_inode(inode, fattr);
1558 
1559 	/* Check if our cached file size is stale */
1560  	new_isize = nfs_size_to_loff_t(fattr->size);
1561 	cur_isize = i_size_read(inode);
1562 	if (new_isize != cur_isize) {
1563 		/* Do we perhaps have any outstanding writes? */
1564 		if (nfsi->npages == 0) {
1565 			/* No, but did we race with nfs_end_data_update()? */
1566 			if (data_stable) {
1567 				inode->i_size = new_isize;
1568 				invalid |= NFS_INO_INVALID_DATA;
1569 			}
1570 			invalid |= NFS_INO_INVALID_ATTR;
1571 		} else if (new_isize > cur_isize) {
1572 			inode->i_size = new_isize;
1573 			invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA;
1574 		}
1575 		nfsi->cache_change_attribute = jiffies;
1576 		dprintk("NFS: isize change on server for file %s/%ld\n",
1577 				inode->i_sb->s_id, inode->i_ino);
1578 	}
1579 
1580 	/* Check if the mtime agrees */
1581 	if (!timespec_equal(&inode->i_mtime, &fattr->mtime)) {
1582 		memcpy(&inode->i_mtime, &fattr->mtime, sizeof(inode->i_mtime));
1583 		dprintk("NFS: mtime change on server for file %s/%ld\n",
1584 				inode->i_sb->s_id, inode->i_ino);
1585 		invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA;
1586 		nfsi->cache_change_attribute = jiffies;
1587 	}
1588 
1589 	/* If ctime has changed we should definitely clear access+acl caches */
1590 	if (!timespec_equal(&inode->i_ctime, &fattr->ctime)) {
1591 		invalid |= NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1592 		memcpy(&inode->i_ctime, &fattr->ctime, sizeof(inode->i_ctime));
1593 		nfsi->cache_change_attribute = jiffies;
1594 	}
1595 	memcpy(&inode->i_atime, &fattr->atime, sizeof(inode->i_atime));
1596 
1597 	if ((inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO) ||
1598 	    inode->i_uid != fattr->uid ||
1599 	    inode->i_gid != fattr->gid)
1600 		invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1601 
1602 	inode->i_mode = fattr->mode;
1603 	inode->i_nlink = fattr->nlink;
1604 	inode->i_uid = fattr->uid;
1605 	inode->i_gid = fattr->gid;
1606 
1607 	if (fattr->valid & (NFS_ATTR_FATTR_V3 | NFS_ATTR_FATTR_V4)) {
1608 		/*
1609 		 * report the blocks in 512byte units
1610 		 */
1611 		inode->i_blocks = nfs_calc_block_size(fattr->du.nfs3.used);
1612 		inode->i_blksize = inode->i_sb->s_blocksize;
1613  	} else {
1614  		inode->i_blocks = fattr->du.nfs2.blocks;
1615  		inode->i_blksize = fattr->du.nfs2.blocksize;
1616  	}
1617 
1618 	if ((fattr->valid & NFS_ATTR_FATTR_V4)) {
1619 		if (nfsi->change_attr != fattr->change_attr) {
1620 			dprintk("NFS: change_attr change on server for file %s/%ld\n",
1621 					inode->i_sb->s_id, inode->i_ino);
1622 			nfsi->change_attr = fattr->change_attr;
1623 			invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1624 			nfsi->cache_change_attribute = jiffies;
1625 		} else
1626 			invalid &= ~(NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA);
1627 	}
1628 
1629 	/* Update attrtimeo value if we're out of the unstable period */
1630 	if (invalid & NFS_INO_INVALID_ATTR) {
1631 		nfs_inc_stats(inode, NFSIOS_ATTRINVALIDATE);
1632 		nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
1633 		nfsi->attrtimeo_timestamp = jiffies;
1634 	} else if (time_after(jiffies, nfsi->attrtimeo_timestamp+nfsi->attrtimeo)) {
1635 		if ((nfsi->attrtimeo <<= 1) > NFS_MAXATTRTIMEO(inode))
1636 			nfsi->attrtimeo = NFS_MAXATTRTIMEO(inode);
1637 		nfsi->attrtimeo_timestamp = jiffies;
1638 	}
1639 	/* Don't invalidate the data if we were to blame */
1640 	if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)
1641 				|| S_ISLNK(inode->i_mode)))
1642 		invalid &= ~NFS_INO_INVALID_DATA;
1643 	if (data_stable)
1644 		invalid &= ~(NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ATIME|NFS_INO_REVAL_PAGECACHE);
1645 	if (!nfs_have_delegation(inode, FMODE_READ))
1646 		nfsi->cache_validity |= invalid;
1647 
1648 	return 0;
1649  out_changed:
1650 	/*
1651 	 * Big trouble! The inode has become a different object.
1652 	 */
1653 #ifdef NFS_PARANOIA
1654 	printk(KERN_DEBUG "%s: inode %ld mode changed, %07o to %07o\n",
1655 			__FUNCTION__, inode->i_ino, inode->i_mode, fattr->mode);
1656 #endif
1657  out_err:
1658 	/*
1659 	 * No need to worry about unhashing the dentry, as the
1660 	 * lookup validation will know that the inode is bad.
1661 	 * (But we fall through to invalidate the caches.)
1662 	 */
1663 	nfs_invalidate_inode(inode);
1664 	return -ESTALE;
1665 
1666  out_fileid:
1667 	printk(KERN_ERR "NFS: server %s error: fileid changed\n"
1668 		"fsid %s: expected fileid 0x%Lx, got 0x%Lx\n",
1669 		NFS_SERVER(inode)->hostname, inode->i_sb->s_id,
1670 		(long long)nfsi->fileid, (long long)fattr->fileid);
1671 	goto out_err;
1672 }
1673 
1674 /*
1675  * File system information
1676  */
1677 
1678 static int nfs_set_super(struct super_block *s, void *data)
1679 {
1680 	s->s_fs_info = data;
1681 	return set_anon_super(s, data);
1682 }
1683 
1684 static int nfs_compare_super(struct super_block *sb, void *data)
1685 {
1686 	struct nfs_server *server = data;
1687 	struct nfs_server *old = NFS_SB(sb);
1688 
1689 	if (old->addr.sin_addr.s_addr != server->addr.sin_addr.s_addr)
1690 		return 0;
1691 	if (old->addr.sin_port != server->addr.sin_port)
1692 		return 0;
1693 	return !nfs_compare_fh(&old->fh, &server->fh);
1694 }
1695 
1696 static struct super_block *nfs_get_sb(struct file_system_type *fs_type,
1697 	int flags, const char *dev_name, void *raw_data)
1698 {
1699 	int error;
1700 	struct nfs_server *server = NULL;
1701 	struct super_block *s;
1702 	struct nfs_fh *root;
1703 	struct nfs_mount_data *data = raw_data;
1704 
1705 	s = ERR_PTR(-EINVAL);
1706 	if (data == NULL) {
1707 		dprintk("%s: missing data argument\n", __FUNCTION__);
1708 		goto out_err;
1709 	}
1710 	if (data->version <= 0 || data->version > NFS_MOUNT_VERSION) {
1711 		dprintk("%s: bad mount version\n", __FUNCTION__);
1712 		goto out_err;
1713 	}
1714 	switch (data->version) {
1715 		case 1:
1716 			data->namlen = 0;
1717 		case 2:
1718 			data->bsize  = 0;
1719 		case 3:
1720 			if (data->flags & NFS_MOUNT_VER3) {
1721 				dprintk("%s: mount structure version %d does not support NFSv3\n",
1722 						__FUNCTION__,
1723 						data->version);
1724 				goto out_err;
1725 			}
1726 			data->root.size = NFS2_FHSIZE;
1727 			memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1728 		case 4:
1729 			if (data->flags & NFS_MOUNT_SECFLAVOUR) {
1730 				dprintk("%s: mount structure version %d does not support strong security\n",
1731 						__FUNCTION__,
1732 						data->version);
1733 				goto out_err;
1734 			}
1735 		case 5:
1736 			memset(data->context, 0, sizeof(data->context));
1737 	}
1738 #ifndef CONFIG_NFS_V3
1739 	/* If NFSv3 is not compiled in, return -EPROTONOSUPPORT */
1740 	s = ERR_PTR(-EPROTONOSUPPORT);
1741 	if (data->flags & NFS_MOUNT_VER3) {
1742 		dprintk("%s: NFSv3 not compiled into kernel\n", __FUNCTION__);
1743 		goto out_err;
1744 	}
1745 #endif /* CONFIG_NFS_V3 */
1746 
1747 	s = ERR_PTR(-ENOMEM);
1748 	server = kzalloc(sizeof(struct nfs_server), GFP_KERNEL);
1749 	if (!server)
1750 		goto out_err;
1751 	/* Zero out the NFS state stuff */
1752 	init_nfsv4_state(server);
1753 	server->client = server->client_sys = server->client_acl = ERR_PTR(-EINVAL);
1754 
1755 	root = &server->fh;
1756 	if (data->flags & NFS_MOUNT_VER3)
1757 		root->size = data->root.size;
1758 	else
1759 		root->size = NFS2_FHSIZE;
1760 	s = ERR_PTR(-EINVAL);
1761 	if (root->size > sizeof(root->data)) {
1762 		dprintk("%s: invalid root filehandle\n", __FUNCTION__);
1763 		goto out_err;
1764 	}
1765 	memcpy(root->data, data->root.data, root->size);
1766 
1767 	/* We now require that the mount process passes the remote address */
1768 	memcpy(&server->addr, &data->addr, sizeof(server->addr));
1769 	if (server->addr.sin_addr.s_addr == INADDR_ANY) {
1770 		dprintk("%s: mount program didn't pass remote address!\n",
1771 				__FUNCTION__);
1772 		goto out_err;
1773 	}
1774 
1775 	/* Fire up rpciod if not yet running */
1776 	s = ERR_PTR(rpciod_up());
1777 	if (IS_ERR(s)) {
1778 		dprintk("%s: couldn't start rpciod! Error = %ld\n",
1779 				__FUNCTION__, PTR_ERR(s));
1780 		goto out_err;
1781 	}
1782 
1783 	s = sget(fs_type, nfs_compare_super, nfs_set_super, server);
1784 	if (IS_ERR(s) || s->s_root)
1785 		goto out_rpciod_down;
1786 
1787 	s->s_flags = flags;
1788 
1789 	error = nfs_fill_super(s, data, flags & MS_SILENT ? 1 : 0);
1790 	if (error) {
1791 		up_write(&s->s_umount);
1792 		deactivate_super(s);
1793 		return ERR_PTR(error);
1794 	}
1795 	s->s_flags |= MS_ACTIVE;
1796 	return s;
1797 out_rpciod_down:
1798 	rpciod_down();
1799 out_err:
1800 	kfree(server);
1801 	return s;
1802 }
1803 
1804 static void nfs_kill_super(struct super_block *s)
1805 {
1806 	struct nfs_server *server = NFS_SB(s);
1807 
1808 	kill_anon_super(s);
1809 
1810 	if (!IS_ERR(server->client))
1811 		rpc_shutdown_client(server->client);
1812 	if (!IS_ERR(server->client_sys))
1813 		rpc_shutdown_client(server->client_sys);
1814 	if (!IS_ERR(server->client_acl))
1815 		rpc_shutdown_client(server->client_acl);
1816 
1817 	if (!(server->flags & NFS_MOUNT_NONLM))
1818 		lockd_down();	/* release rpc.lockd */
1819 
1820 	rpciod_down();		/* release rpciod */
1821 
1822 	nfs_free_iostats(server->io_stats);
1823 	kfree(server->hostname);
1824 	kfree(server);
1825 }
1826 
1827 static struct file_system_type nfs_fs_type = {
1828 	.owner		= THIS_MODULE,
1829 	.name		= "nfs",
1830 	.get_sb		= nfs_get_sb,
1831 	.kill_sb	= nfs_kill_super,
1832 	.fs_flags	= FS_ODD_RENAME|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
1833 };
1834 
1835 #ifdef CONFIG_NFS_V4
1836 
1837 static void nfs4_clear_inode(struct inode *);
1838 
1839 
1840 static struct super_operations nfs4_sops = {
1841 	.alloc_inode	= nfs_alloc_inode,
1842 	.destroy_inode	= nfs_destroy_inode,
1843 	.write_inode	= nfs_write_inode,
1844 	.delete_inode	= nfs_delete_inode,
1845 	.statfs		= nfs_statfs,
1846 	.clear_inode	= nfs4_clear_inode,
1847 	.umount_begin	= nfs_umount_begin,
1848 	.show_options	= nfs_show_options,
1849 	.show_stats	= nfs_show_stats,
1850 };
1851 
1852 /*
1853  * Clean out any remaining NFSv4 state that might be left over due
1854  * to open() calls that passed nfs_atomic_lookup, but failed to call
1855  * nfs_open().
1856  */
1857 static void nfs4_clear_inode(struct inode *inode)
1858 {
1859 	struct nfs_inode *nfsi = NFS_I(inode);
1860 
1861 	/* If we are holding a delegation, return it! */
1862 	nfs_inode_return_delegation(inode);
1863 	/* First call standard NFS clear_inode() code */
1864 	nfs_clear_inode(inode);
1865 	/* Now clear out any remaining state */
1866 	while (!list_empty(&nfsi->open_states)) {
1867 		struct nfs4_state *state;
1868 
1869 		state = list_entry(nfsi->open_states.next,
1870 				struct nfs4_state,
1871 				inode_states);
1872 		dprintk("%s(%s/%Ld): found unclaimed NFSv4 state %p\n",
1873 				__FUNCTION__,
1874 				inode->i_sb->s_id,
1875 				(long long)NFS_FILEID(inode),
1876 				state);
1877 		BUG_ON(atomic_read(&state->count) != 1);
1878 		nfs4_close_state(state, state->state);
1879 	}
1880 }
1881 
1882 
1883 static int nfs4_fill_super(struct super_block *sb, struct nfs4_mount_data *data, int silent)
1884 {
1885 	struct nfs_server *server;
1886 	struct nfs4_client *clp = NULL;
1887 	struct rpc_xprt *xprt = NULL;
1888 	struct rpc_clnt *clnt = NULL;
1889 	struct rpc_timeout timeparms;
1890 	rpc_authflavor_t authflavour;
1891 	int err = -EIO;
1892 
1893 	sb->s_blocksize_bits = 0;
1894 	sb->s_blocksize = 0;
1895 	server = NFS_SB(sb);
1896 	if (data->rsize != 0)
1897 		server->rsize = nfs_block_size(data->rsize, NULL);
1898 	if (data->wsize != 0)
1899 		server->wsize = nfs_block_size(data->wsize, NULL);
1900 	server->flags = data->flags & NFS_MOUNT_FLAGMASK;
1901 	server->caps = NFS_CAP_ATOMIC_OPEN;
1902 
1903 	server->acregmin = data->acregmin*HZ;
1904 	server->acregmax = data->acregmax*HZ;
1905 	server->acdirmin = data->acdirmin*HZ;
1906 	server->acdirmax = data->acdirmax*HZ;
1907 
1908 	server->rpc_ops = &nfs_v4_clientops;
1909 
1910 	nfs_init_timeout_values(&timeparms, data->proto, data->timeo, data->retrans);
1911 
1912 	server->retrans_timeo = timeparms.to_initval;
1913 	server->retrans_count = timeparms.to_retries;
1914 
1915 	clp = nfs4_get_client(&server->addr.sin_addr);
1916 	if (!clp) {
1917 		dprintk("%s: failed to create NFS4 client.\n", __FUNCTION__);
1918 		return -EIO;
1919 	}
1920 
1921 	/* Now create transport and client */
1922 	authflavour = RPC_AUTH_UNIX;
1923 	if (data->auth_flavourlen != 0) {
1924 		if (data->auth_flavourlen != 1) {
1925 			dprintk("%s: Invalid number of RPC auth flavours %d.\n",
1926 					__FUNCTION__, data->auth_flavourlen);
1927 			err = -EINVAL;
1928 			goto out_fail;
1929 		}
1930 		if (copy_from_user(&authflavour, data->auth_flavours, sizeof(authflavour))) {
1931 			err = -EFAULT;
1932 			goto out_fail;
1933 		}
1934 	}
1935 
1936 	down_write(&clp->cl_sem);
1937 	if (IS_ERR(clp->cl_rpcclient)) {
1938 		xprt = xprt_create_proto(data->proto, &server->addr, &timeparms);
1939 		if (IS_ERR(xprt)) {
1940 			up_write(&clp->cl_sem);
1941 			err = PTR_ERR(xprt);
1942 			dprintk("%s: cannot create RPC transport. Error = %d\n",
1943 					__FUNCTION__, err);
1944 			goto out_fail;
1945 		}
1946 		clnt = rpc_create_client(xprt, server->hostname, &nfs_program,
1947 				server->rpc_ops->version, authflavour);
1948 		if (IS_ERR(clnt)) {
1949 			up_write(&clp->cl_sem);
1950 			err = PTR_ERR(clnt);
1951 			dprintk("%s: cannot create RPC client. Error = %d\n",
1952 					__FUNCTION__, err);
1953 			goto out_fail;
1954 		}
1955 		clnt->cl_intr     = 1;
1956 		clnt->cl_softrtry = 1;
1957 		clp->cl_rpcclient = clnt;
1958 		memcpy(clp->cl_ipaddr, server->ip_addr, sizeof(clp->cl_ipaddr));
1959 		nfs_idmap_new(clp);
1960 	}
1961 	list_add_tail(&server->nfs4_siblings, &clp->cl_superblocks);
1962 	clnt = rpc_clone_client(clp->cl_rpcclient);
1963 	if (!IS_ERR(clnt))
1964 			server->nfs4_state = clp;
1965 	up_write(&clp->cl_sem);
1966 	clp = NULL;
1967 
1968 	if (IS_ERR(clnt)) {
1969 		err = PTR_ERR(clnt);
1970 		dprintk("%s: cannot create RPC client. Error = %d\n",
1971 				__FUNCTION__, err);
1972 		return err;
1973 	}
1974 
1975 	server->client    = clnt;
1976 
1977 	if (server->nfs4_state->cl_idmap == NULL) {
1978 		dprintk("%s: failed to create idmapper.\n", __FUNCTION__);
1979 		return -ENOMEM;
1980 	}
1981 
1982 	if (clnt->cl_auth->au_flavor != authflavour) {
1983 		struct rpc_auth *auth;
1984 
1985 		auth = rpcauth_create(authflavour, clnt);
1986 		if (IS_ERR(auth)) {
1987 			dprintk("%s: couldn't create credcache!\n", __FUNCTION__);
1988 			return PTR_ERR(auth);
1989 		}
1990 	}
1991 
1992 	sb->s_time_gran = 1;
1993 
1994 	sb->s_op = &nfs4_sops;
1995 	err = nfs_sb_init(sb, authflavour);
1996 	if (err == 0)
1997 		return 0;
1998 out_fail:
1999 	if (clp)
2000 		nfs4_put_client(clp);
2001 	return err;
2002 }
2003 
2004 static int nfs4_compare_super(struct super_block *sb, void *data)
2005 {
2006 	struct nfs_server *server = data;
2007 	struct nfs_server *old = NFS_SB(sb);
2008 
2009 	if (strcmp(server->hostname, old->hostname) != 0)
2010 		return 0;
2011 	if (strcmp(server->mnt_path, old->mnt_path) != 0)
2012 		return 0;
2013 	return 1;
2014 }
2015 
2016 static void *
2017 nfs_copy_user_string(char *dst, struct nfs_string *src, int maxlen)
2018 {
2019 	void *p = NULL;
2020 
2021 	if (!src->len)
2022 		return ERR_PTR(-EINVAL);
2023 	if (src->len < maxlen)
2024 		maxlen = src->len;
2025 	if (dst == NULL) {
2026 		p = dst = kmalloc(maxlen + 1, GFP_KERNEL);
2027 		if (p == NULL)
2028 			return ERR_PTR(-ENOMEM);
2029 	}
2030 	if (copy_from_user(dst, src->data, maxlen)) {
2031 		kfree(p);
2032 		return ERR_PTR(-EFAULT);
2033 	}
2034 	dst[maxlen] = '\0';
2035 	return dst;
2036 }
2037 
2038 static struct super_block *nfs4_get_sb(struct file_system_type *fs_type,
2039 	int flags, const char *dev_name, void *raw_data)
2040 {
2041 	int error;
2042 	struct nfs_server *server;
2043 	struct super_block *s;
2044 	struct nfs4_mount_data *data = raw_data;
2045 	void *p;
2046 
2047 	if (data == NULL) {
2048 		dprintk("%s: missing data argument\n", __FUNCTION__);
2049 		return ERR_PTR(-EINVAL);
2050 	}
2051 	if (data->version <= 0 || data->version > NFS4_MOUNT_VERSION) {
2052 		dprintk("%s: bad mount version\n", __FUNCTION__);
2053 		return ERR_PTR(-EINVAL);
2054 	}
2055 
2056 	server = kzalloc(sizeof(struct nfs_server), GFP_KERNEL);
2057 	if (!server)
2058 		return ERR_PTR(-ENOMEM);
2059 	/* Zero out the NFS state stuff */
2060 	init_nfsv4_state(server);
2061 	server->client = server->client_sys = server->client_acl = ERR_PTR(-EINVAL);
2062 
2063 	p = nfs_copy_user_string(NULL, &data->hostname, 256);
2064 	if (IS_ERR(p))
2065 		goto out_err;
2066 	server->hostname = p;
2067 
2068 	p = nfs_copy_user_string(NULL, &data->mnt_path, 1024);
2069 	if (IS_ERR(p))
2070 		goto out_err;
2071 	server->mnt_path = p;
2072 
2073 	p = nfs_copy_user_string(server->ip_addr, &data->client_addr,
2074 			sizeof(server->ip_addr) - 1);
2075 	if (IS_ERR(p))
2076 		goto out_err;
2077 
2078 	/* We now require that the mount process passes the remote address */
2079 	if (data->host_addrlen != sizeof(server->addr)) {
2080 		s = ERR_PTR(-EINVAL);
2081 		goto out_free;
2082 	}
2083 	if (copy_from_user(&server->addr, data->host_addr, sizeof(server->addr))) {
2084 		s = ERR_PTR(-EFAULT);
2085 		goto out_free;
2086 	}
2087 	if (server->addr.sin_family != AF_INET ||
2088 	    server->addr.sin_addr.s_addr == INADDR_ANY) {
2089 		dprintk("%s: mount program didn't pass remote IP address!\n",
2090 				__FUNCTION__);
2091 		s = ERR_PTR(-EINVAL);
2092 		goto out_free;
2093 	}
2094 
2095 	/* Fire up rpciod if not yet running */
2096 	s = ERR_PTR(rpciod_up());
2097 	if (IS_ERR(s)) {
2098 		dprintk("%s: couldn't start rpciod! Error = %ld\n",
2099 				__FUNCTION__, PTR_ERR(s));
2100 		goto out_free;
2101 	}
2102 
2103 	s = sget(fs_type, nfs4_compare_super, nfs_set_super, server);
2104 
2105 	if (IS_ERR(s) || s->s_root)
2106 		goto out_free;
2107 
2108 	s->s_flags = flags;
2109 
2110 	error = nfs4_fill_super(s, data, flags & MS_SILENT ? 1 : 0);
2111 	if (error) {
2112 		up_write(&s->s_umount);
2113 		deactivate_super(s);
2114 		return ERR_PTR(error);
2115 	}
2116 	s->s_flags |= MS_ACTIVE;
2117 	return s;
2118 out_err:
2119 	s = (struct super_block *)p;
2120 out_free:
2121 	kfree(server->mnt_path);
2122 	kfree(server->hostname);
2123 	kfree(server);
2124 	return s;
2125 }
2126 
2127 static void nfs4_kill_super(struct super_block *sb)
2128 {
2129 	struct nfs_server *server = NFS_SB(sb);
2130 
2131 	nfs_return_all_delegations(sb);
2132 	kill_anon_super(sb);
2133 
2134 	nfs4_renewd_prepare_shutdown(server);
2135 
2136 	if (server->client != NULL && !IS_ERR(server->client))
2137 		rpc_shutdown_client(server->client);
2138 
2139 	destroy_nfsv4_state(server);
2140 
2141 	rpciod_down();
2142 
2143 	nfs_free_iostats(server->io_stats);
2144 	kfree(server->hostname);
2145 	kfree(server);
2146 }
2147 
2148 static struct file_system_type nfs4_fs_type = {
2149 	.owner		= THIS_MODULE,
2150 	.name		= "nfs4",
2151 	.get_sb		= nfs4_get_sb,
2152 	.kill_sb	= nfs4_kill_super,
2153 	.fs_flags	= FS_ODD_RENAME|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
2154 };
2155 
2156 static const int nfs_set_port_min = 0;
2157 static const int nfs_set_port_max = 65535;
2158 static int param_set_port(const char *val, struct kernel_param *kp)
2159 {
2160 	char *endp;
2161 	int num = simple_strtol(val, &endp, 0);
2162 	if (endp == val || *endp || num < nfs_set_port_min || num > nfs_set_port_max)
2163 		return -EINVAL;
2164 	*((int *)kp->arg) = num;
2165 	return 0;
2166 }
2167 
2168 module_param_call(callback_tcpport, param_set_port, param_get_int,
2169 		 &nfs_callback_set_tcpport, 0644);
2170 
2171 static int param_set_idmap_timeout(const char *val, struct kernel_param *kp)
2172 {
2173 	char *endp;
2174 	int num = simple_strtol(val, &endp, 0);
2175 	int jif = num * HZ;
2176 	if (endp == val || *endp || num < 0 || jif < num)
2177 		return -EINVAL;
2178 	*((int *)kp->arg) = jif;
2179 	return 0;
2180 }
2181 
2182 module_param_call(idmap_cache_timeout, param_set_idmap_timeout, param_get_int,
2183 		 &nfs_idmap_cache_timeout, 0644);
2184 
2185 #define nfs4_init_once(nfsi) \
2186 	do { \
2187 		INIT_LIST_HEAD(&(nfsi)->open_states); \
2188 		nfsi->delegation = NULL; \
2189 		nfsi->delegation_state = 0; \
2190 		init_rwsem(&nfsi->rwsem); \
2191 	} while(0)
2192 
2193 static inline int register_nfs4fs(void)
2194 {
2195 	int ret;
2196 
2197 	ret = nfs_register_sysctl();
2198 	if (ret != 0)
2199 		return ret;
2200 	ret = register_filesystem(&nfs4_fs_type);
2201 	if (ret != 0)
2202 		nfs_unregister_sysctl();
2203 	return ret;
2204 }
2205 
2206 static inline void unregister_nfs4fs(void)
2207 {
2208 	unregister_filesystem(&nfs4_fs_type);
2209 	nfs_unregister_sysctl();
2210 }
2211 #else
2212 #define nfs4_init_once(nfsi) \
2213 	do { } while (0)
2214 #define register_nfs4fs() (0)
2215 #define unregister_nfs4fs()
2216 #endif
2217 
2218 extern int nfs_init_nfspagecache(void);
2219 extern void nfs_destroy_nfspagecache(void);
2220 extern int nfs_init_readpagecache(void);
2221 extern void nfs_destroy_readpagecache(void);
2222 extern int nfs_init_writepagecache(void);
2223 extern void nfs_destroy_writepagecache(void);
2224 #ifdef CONFIG_NFS_DIRECTIO
2225 extern int nfs_init_directcache(void);
2226 extern void nfs_destroy_directcache(void);
2227 #endif
2228 
2229 static kmem_cache_t * nfs_inode_cachep;
2230 
2231 static struct inode *nfs_alloc_inode(struct super_block *sb)
2232 {
2233 	struct nfs_inode *nfsi;
2234 	nfsi = (struct nfs_inode *)kmem_cache_alloc(nfs_inode_cachep, SLAB_KERNEL);
2235 	if (!nfsi)
2236 		return NULL;
2237 	nfsi->flags = 0UL;
2238 	nfsi->cache_validity = 0UL;
2239 	nfsi->cache_change_attribute = jiffies;
2240 #ifdef CONFIG_NFS_V3_ACL
2241 	nfsi->acl_access = ERR_PTR(-EAGAIN);
2242 	nfsi->acl_default = ERR_PTR(-EAGAIN);
2243 #endif
2244 #ifdef CONFIG_NFS_V4
2245 	nfsi->nfs4_acl = NULL;
2246 #endif /* CONFIG_NFS_V4 */
2247 	return &nfsi->vfs_inode;
2248 }
2249 
2250 static void nfs_destroy_inode(struct inode *inode)
2251 {
2252 	kmem_cache_free(nfs_inode_cachep, NFS_I(inode));
2253 }
2254 
2255 static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
2256 {
2257 	struct nfs_inode *nfsi = (struct nfs_inode *) foo;
2258 
2259 	if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
2260 	    SLAB_CTOR_CONSTRUCTOR) {
2261 		inode_init_once(&nfsi->vfs_inode);
2262 		spin_lock_init(&nfsi->req_lock);
2263 		INIT_LIST_HEAD(&nfsi->dirty);
2264 		INIT_LIST_HEAD(&nfsi->commit);
2265 		INIT_LIST_HEAD(&nfsi->open_files);
2266 		INIT_RADIX_TREE(&nfsi->nfs_page_tree, GFP_ATOMIC);
2267 		atomic_set(&nfsi->data_updates, 0);
2268 		nfsi->ndirty = 0;
2269 		nfsi->ncommit = 0;
2270 		nfsi->npages = 0;
2271 		nfs4_init_once(nfsi);
2272 	}
2273 }
2274 
2275 static int nfs_init_inodecache(void)
2276 {
2277 	nfs_inode_cachep = kmem_cache_create("nfs_inode_cache",
2278 					     sizeof(struct nfs_inode),
2279 					     0, (SLAB_RECLAIM_ACCOUNT|
2280 						SLAB_MEM_SPREAD),
2281 					     init_once, NULL);
2282 	if (nfs_inode_cachep == NULL)
2283 		return -ENOMEM;
2284 
2285 	return 0;
2286 }
2287 
2288 static void nfs_destroy_inodecache(void)
2289 {
2290 	if (kmem_cache_destroy(nfs_inode_cachep))
2291 		printk(KERN_INFO "nfs_inode_cache: not all structures were freed\n");
2292 }
2293 
2294 /*
2295  * Initialize NFS
2296  */
2297 static int __init init_nfs_fs(void)
2298 {
2299 	int err;
2300 
2301 	err = nfs_init_nfspagecache();
2302 	if (err)
2303 		goto out4;
2304 
2305 	err = nfs_init_inodecache();
2306 	if (err)
2307 		goto out3;
2308 
2309 	err = nfs_init_readpagecache();
2310 	if (err)
2311 		goto out2;
2312 
2313 	err = nfs_init_writepagecache();
2314 	if (err)
2315 		goto out1;
2316 
2317 #ifdef CONFIG_NFS_DIRECTIO
2318 	err = nfs_init_directcache();
2319 	if (err)
2320 		goto out0;
2321 #endif
2322 
2323 #ifdef CONFIG_PROC_FS
2324 	rpc_proc_register(&nfs_rpcstat);
2325 #endif
2326         err = register_filesystem(&nfs_fs_type);
2327 	if (err)
2328 		goto out;
2329 	if ((err = register_nfs4fs()) != 0)
2330 		goto out;
2331 	return 0;
2332 out:
2333 #ifdef CONFIG_PROC_FS
2334 	rpc_proc_unregister("nfs");
2335 #endif
2336 #ifdef CONFIG_NFS_DIRECTIO
2337 	nfs_destroy_directcache();
2338 out0:
2339 #endif
2340 	nfs_destroy_writepagecache();
2341 out1:
2342 	nfs_destroy_readpagecache();
2343 out2:
2344 	nfs_destroy_inodecache();
2345 out3:
2346 	nfs_destroy_nfspagecache();
2347 out4:
2348 	return err;
2349 }
2350 
2351 static void __exit exit_nfs_fs(void)
2352 {
2353 #ifdef CONFIG_NFS_DIRECTIO
2354 	nfs_destroy_directcache();
2355 #endif
2356 	nfs_destroy_writepagecache();
2357 	nfs_destroy_readpagecache();
2358 	nfs_destroy_inodecache();
2359 	nfs_destroy_nfspagecache();
2360 #ifdef CONFIG_PROC_FS
2361 	rpc_proc_unregister("nfs");
2362 #endif
2363 	unregister_filesystem(&nfs_fs_type);
2364 	unregister_nfs4fs();
2365 }
2366 
2367 /* Not quite true; I just maintain it */
2368 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
2369 MODULE_LICENSE("GPL");
2370 
2371 module_init(init_nfs_fs)
2372 module_exit(exit_nfs_fs)
2373