xref: /linux/fs/nfs/inode.c (revision 13abf8130139c2ccd4962a7e5a8902be5e6cb5a7)
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/nfs_fs.h>
30 #include <linux/nfs_mount.h>
31 #include <linux/nfs4_mount.h>
32 #include <linux/lockd/bind.h>
33 #include <linux/smp_lock.h>
34 #include <linux/seq_file.h>
35 #include <linux/mount.h>
36 #include <linux/nfs_idmap.h>
37 #include <linux/vfs.h>
38 
39 #include <asm/system.h>
40 #include <asm/uaccess.h>
41 
42 #include "nfs4_fs.h"
43 #include "delegation.h"
44 
45 #define NFSDBG_FACILITY		NFSDBG_VFS
46 #define NFS_PARANOIA 1
47 
48 /* Maximum number of readahead requests
49  * FIXME: this should really be a sysctl so that users may tune it to suit
50  *        their needs. People that do NFS over a slow network, might for
51  *        instance want to reduce it to something closer to 1 for improved
52  *        interactive response.
53  */
54 #define NFS_MAX_READAHEAD	(RPC_DEF_SLOT_TABLE - 1)
55 
56 static void nfs_invalidate_inode(struct inode *);
57 static int nfs_update_inode(struct inode *, struct nfs_fattr *, unsigned long);
58 
59 static struct inode *nfs_alloc_inode(struct super_block *sb);
60 static void nfs_destroy_inode(struct inode *);
61 static int nfs_write_inode(struct inode *,int);
62 static void nfs_delete_inode(struct inode *);
63 static void nfs_clear_inode(struct inode *);
64 static void nfs_umount_begin(struct super_block *);
65 static int  nfs_statfs(struct super_block *, struct kstatfs *);
66 static int  nfs_show_options(struct seq_file *, struct vfsmount *);
67 static void nfs_zap_acl_cache(struct inode *);
68 
69 static struct rpc_program	nfs_program;
70 
71 static struct super_operations nfs_sops = {
72 	.alloc_inode	= nfs_alloc_inode,
73 	.destroy_inode	= nfs_destroy_inode,
74 	.write_inode	= nfs_write_inode,
75 	.delete_inode	= nfs_delete_inode,
76 	.statfs		= nfs_statfs,
77 	.clear_inode	= nfs_clear_inode,
78 	.umount_begin	= nfs_umount_begin,
79 	.show_options	= nfs_show_options,
80 };
81 
82 /*
83  * RPC cruft for NFS
84  */
85 static struct rpc_stat		nfs_rpcstat = {
86 	.program		= &nfs_program
87 };
88 static struct rpc_version *	nfs_version[] = {
89 	NULL,
90 	NULL,
91 	&nfs_version2,
92 #if defined(CONFIG_NFS_V3)
93 	&nfs_version3,
94 #elif defined(CONFIG_NFS_V4)
95 	NULL,
96 #endif
97 #if defined(CONFIG_NFS_V4)
98 	&nfs_version4,
99 #endif
100 };
101 
102 static struct rpc_program	nfs_program = {
103 	.name			= "nfs",
104 	.number			= NFS_PROGRAM,
105 	.nrvers			= sizeof(nfs_version) / sizeof(nfs_version[0]),
106 	.version		= nfs_version,
107 	.stats			= &nfs_rpcstat,
108 	.pipe_dir_name		= "/nfs",
109 };
110 
111 #ifdef CONFIG_NFS_V3_ACL
112 static struct rpc_stat		nfsacl_rpcstat = { &nfsacl_program };
113 static struct rpc_version *	nfsacl_version[] = {
114 	[3]			= &nfsacl_version3,
115 };
116 
117 struct rpc_program		nfsacl_program = {
118 	.name =			"nfsacl",
119 	.number =		NFS_ACL_PROGRAM,
120 	.nrvers =		sizeof(nfsacl_version) / sizeof(nfsacl_version[0]),
121 	.version =		nfsacl_version,
122 	.stats =		&nfsacl_rpcstat,
123 };
124 #endif  /* CONFIG_NFS_V3_ACL */
125 
126 static inline unsigned long
127 nfs_fattr_to_ino_t(struct nfs_fattr *fattr)
128 {
129 	return nfs_fileid_to_ino_t(fattr->fileid);
130 }
131 
132 static int
133 nfs_write_inode(struct inode *inode, int sync)
134 {
135 	int flags = sync ? FLUSH_WAIT : 0;
136 	int ret;
137 
138 	ret = nfs_commit_inode(inode, flags);
139 	if (ret < 0)
140 		return ret;
141 	return 0;
142 }
143 
144 static void
145 nfs_delete_inode(struct inode * inode)
146 {
147 	dprintk("NFS: delete_inode(%s/%ld)\n", inode->i_sb->s_id, inode->i_ino);
148 
149 	nfs_wb_all(inode);
150 	/*
151 	 * The following should never happen...
152 	 */
153 	if (nfs_have_writebacks(inode)) {
154 		printk(KERN_ERR "nfs_delete_inode: inode %ld has pending RPC requests\n", inode->i_ino);
155 	}
156 
157 	clear_inode(inode);
158 }
159 
160 static void
161 nfs_clear_inode(struct inode *inode)
162 {
163 	struct nfs_inode *nfsi = NFS_I(inode);
164 	struct rpc_cred *cred;
165 
166 	nfs_wb_all(inode);
167 	BUG_ON (!list_empty(&nfsi->open_files));
168 	nfs_zap_acl_cache(inode);
169 	cred = nfsi->cache_access.cred;
170 	if (cred)
171 		put_rpccred(cred);
172 	BUG_ON(atomic_read(&nfsi->data_updates) != 0);
173 }
174 
175 void
176 nfs_umount_begin(struct super_block *sb)
177 {
178 	struct rpc_clnt	*rpc = NFS_SB(sb)->client;
179 
180 	/* -EIO all pending I/O */
181 	if (!IS_ERR(rpc))
182 		rpc_killall_tasks(rpc);
183 	rpc = NFS_SB(sb)->client_acl;
184 	if (!IS_ERR(rpc))
185 		rpc_killall_tasks(rpc);
186 }
187 
188 
189 static inline unsigned long
190 nfs_block_bits(unsigned long bsize, unsigned char *nrbitsp)
191 {
192 	/* make sure blocksize is a power of two */
193 	if ((bsize & (bsize - 1)) || nrbitsp) {
194 		unsigned char	nrbits;
195 
196 		for (nrbits = 31; nrbits && !(bsize & (1 << nrbits)); nrbits--)
197 			;
198 		bsize = 1 << nrbits;
199 		if (nrbitsp)
200 			*nrbitsp = nrbits;
201 	}
202 
203 	return bsize;
204 }
205 
206 /*
207  * Calculate the number of 512byte blocks used.
208  */
209 static inline unsigned long
210 nfs_calc_block_size(u64 tsize)
211 {
212 	loff_t used = (tsize + 511) >> 9;
213 	return (used > ULONG_MAX) ? ULONG_MAX : used;
214 }
215 
216 /*
217  * Compute and set NFS server blocksize
218  */
219 static inline unsigned long
220 nfs_block_size(unsigned long bsize, unsigned char *nrbitsp)
221 {
222 	if (bsize < 1024)
223 		bsize = NFS_DEF_FILE_IO_BUFFER_SIZE;
224 	else if (bsize >= NFS_MAX_FILE_IO_BUFFER_SIZE)
225 		bsize = NFS_MAX_FILE_IO_BUFFER_SIZE;
226 
227 	return nfs_block_bits(bsize, nrbitsp);
228 }
229 
230 /*
231  * Obtain the root inode of the file system.
232  */
233 static struct inode *
234 nfs_get_root(struct super_block *sb, struct nfs_fh *rootfh, struct nfs_fsinfo *fsinfo)
235 {
236 	struct nfs_server	*server = NFS_SB(sb);
237 	struct inode *rooti;
238 	int			error;
239 
240 	error = server->rpc_ops->getroot(server, rootfh, fsinfo);
241 	if (error < 0) {
242 		dprintk("nfs_get_root: getattr error = %d\n", -error);
243 		return ERR_PTR(error);
244 	}
245 
246 	rooti = nfs_fhget(sb, rootfh, fsinfo->fattr);
247 	if (!rooti)
248 		return ERR_PTR(-ENOMEM);
249 	return rooti;
250 }
251 
252 /*
253  * Do NFS version-independent mount processing, and sanity checking
254  */
255 static int
256 nfs_sb_init(struct super_block *sb, rpc_authflavor_t authflavor)
257 {
258 	struct nfs_server	*server;
259 	struct inode		*root_inode;
260 	struct nfs_fattr	fattr;
261 	struct nfs_fsinfo	fsinfo = {
262 					.fattr = &fattr,
263 				};
264 	struct nfs_pathconf pathinfo = {
265 			.fattr = &fattr,
266 	};
267 	int no_root_error = 0;
268 	unsigned long max_rpc_payload;
269 
270 	/* We probably want something more informative here */
271 	snprintf(sb->s_id, sizeof(sb->s_id), "%x:%x", MAJOR(sb->s_dev), MINOR(sb->s_dev));
272 
273 	server = NFS_SB(sb);
274 
275 	sb->s_magic      = NFS_SUPER_MAGIC;
276 
277 	root_inode = nfs_get_root(sb, &server->fh, &fsinfo);
278 	/* Did getting the root inode fail? */
279 	if (IS_ERR(root_inode)) {
280 		no_root_error = PTR_ERR(root_inode);
281 		goto out_no_root;
282 	}
283 	sb->s_root = d_alloc_root(root_inode);
284 	if (!sb->s_root) {
285 		no_root_error = -ENOMEM;
286 		goto out_no_root;
287 	}
288 	sb->s_root->d_op = server->rpc_ops->dentry_ops;
289 
290 	/* Get some general file system info */
291 	if (server->namelen == 0 &&
292 	    server->rpc_ops->pathconf(server, &server->fh, &pathinfo) >= 0)
293 		server->namelen = pathinfo.max_namelen;
294 	/* Work out a lot of parameters */
295 	if (server->rsize == 0)
296 		server->rsize = nfs_block_size(fsinfo.rtpref, NULL);
297 	if (server->wsize == 0)
298 		server->wsize = nfs_block_size(fsinfo.wtpref, NULL);
299 
300 	if (fsinfo.rtmax >= 512 && server->rsize > fsinfo.rtmax)
301 		server->rsize = nfs_block_size(fsinfo.rtmax, NULL);
302 	if (fsinfo.wtmax >= 512 && server->wsize > fsinfo.wtmax)
303 		server->wsize = nfs_block_size(fsinfo.wtmax, NULL);
304 
305 	max_rpc_payload = nfs_block_size(rpc_max_payload(server->client), NULL);
306 	if (server->rsize > max_rpc_payload)
307 		server->rsize = max_rpc_payload;
308 	if (server->wsize > max_rpc_payload)
309 		server->wsize = max_rpc_payload;
310 
311 	server->rpages = (server->rsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
312 	if (server->rpages > NFS_READ_MAXIOV) {
313 		server->rpages = NFS_READ_MAXIOV;
314 		server->rsize = server->rpages << PAGE_CACHE_SHIFT;
315 	}
316 
317 	server->wpages = (server->wsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
318         if (server->wpages > NFS_WRITE_MAXIOV) {
319 		server->wpages = NFS_WRITE_MAXIOV;
320                 server->wsize = server->wpages << PAGE_CACHE_SHIFT;
321 	}
322 
323 	if (sb->s_blocksize == 0)
324 		sb->s_blocksize = nfs_block_bits(server->wsize,
325 							 &sb->s_blocksize_bits);
326 	server->wtmult = nfs_block_bits(fsinfo.wtmult, NULL);
327 
328 	server->dtsize = nfs_block_size(fsinfo.dtpref, NULL);
329 	if (server->dtsize > PAGE_CACHE_SIZE)
330 		server->dtsize = PAGE_CACHE_SIZE;
331 	if (server->dtsize > server->rsize)
332 		server->dtsize = server->rsize;
333 
334 	if (server->flags & NFS_MOUNT_NOAC) {
335 		server->acregmin = server->acregmax = 0;
336 		server->acdirmin = server->acdirmax = 0;
337 		sb->s_flags |= MS_SYNCHRONOUS;
338 	}
339 	server->backing_dev_info.ra_pages = server->rpages * NFS_MAX_READAHEAD;
340 
341 	sb->s_maxbytes = fsinfo.maxfilesize;
342 	if (sb->s_maxbytes > MAX_LFS_FILESIZE)
343 		sb->s_maxbytes = MAX_LFS_FILESIZE;
344 
345 	server->client->cl_intr = (server->flags & NFS_MOUNT_INTR) ? 1 : 0;
346 	server->client->cl_softrtry = (server->flags & NFS_MOUNT_SOFT) ? 1 : 0;
347 
348 	/* We're airborne Set socket buffersize */
349 	rpc_setbufsize(server->client, server->wsize + 100, server->rsize + 100);
350 	return 0;
351 	/* Yargs. It didn't work out. */
352 out_no_root:
353 	dprintk("nfs_sb_init: get root inode failed: errno %d\n", -no_root_error);
354 	if (!IS_ERR(root_inode))
355 		iput(root_inode);
356 	return no_root_error;
357 }
358 
359 /*
360  * Create an RPC client handle.
361  */
362 static struct rpc_clnt *
363 nfs_create_client(struct nfs_server *server, const struct nfs_mount_data *data)
364 {
365 	struct rpc_timeout	timeparms;
366 	struct rpc_xprt		*xprt = NULL;
367 	struct rpc_clnt		*clnt = NULL;
368 	int			tcp   = (data->flags & NFS_MOUNT_TCP);
369 
370 	/* Initialize timeout values */
371 	timeparms.to_initval = data->timeo * HZ / 10;
372 	timeparms.to_retries = data->retrans;
373 	timeparms.to_maxval  = tcp ? RPC_MAX_TCP_TIMEOUT : RPC_MAX_UDP_TIMEOUT;
374 	timeparms.to_exponential = 1;
375 
376 	if (!timeparms.to_initval)
377 		timeparms.to_initval = (tcp ? 600 : 11) * HZ / 10;
378 	if (!timeparms.to_retries)
379 		timeparms.to_retries = 5;
380 
381 	/* create transport and client */
382 	xprt = xprt_create_proto(tcp ? IPPROTO_TCP : IPPROTO_UDP,
383 				 &server->addr, &timeparms);
384 	if (IS_ERR(xprt)) {
385 		dprintk("%s: cannot create RPC transport. Error = %ld\n",
386 				__FUNCTION__, PTR_ERR(xprt));
387 		return (struct rpc_clnt *)xprt;
388 	}
389 	clnt = rpc_create_client(xprt, server->hostname, &nfs_program,
390 				 server->rpc_ops->version, data->pseudoflavor);
391 	if (IS_ERR(clnt)) {
392 		dprintk("%s: cannot create RPC client. Error = %ld\n",
393 				__FUNCTION__, PTR_ERR(xprt));
394 		goto out_fail;
395 	}
396 
397 	clnt->cl_intr     = 1;
398 	clnt->cl_softrtry = 1;
399 	clnt->cl_chatty   = 1;
400 
401 	return clnt;
402 
403 out_fail:
404 	return clnt;
405 }
406 
407 /*
408  * The way this works is that the mount process passes a structure
409  * in the data argument which contains the server's IP address
410  * and the root file handle obtained from the server's mount
411  * daemon. We stash these away in the private superblock fields.
412  */
413 static int
414 nfs_fill_super(struct super_block *sb, struct nfs_mount_data *data, int silent)
415 {
416 	struct nfs_server	*server;
417 	rpc_authflavor_t	authflavor;
418 
419 	server           = NFS_SB(sb);
420 	sb->s_blocksize_bits = 0;
421 	sb->s_blocksize = 0;
422 	if (data->bsize)
423 		sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
424 	if (data->rsize)
425 		server->rsize = nfs_block_size(data->rsize, NULL);
426 	if (data->wsize)
427 		server->wsize = nfs_block_size(data->wsize, NULL);
428 	server->flags    = data->flags & NFS_MOUNT_FLAGMASK;
429 
430 	server->acregmin = data->acregmin*HZ;
431 	server->acregmax = data->acregmax*HZ;
432 	server->acdirmin = data->acdirmin*HZ;
433 	server->acdirmax = data->acdirmax*HZ;
434 
435 	/* Start lockd here, before we might error out */
436 	if (!(server->flags & NFS_MOUNT_NONLM))
437 		lockd_up();
438 
439 	server->namelen  = data->namlen;
440 	server->hostname = kmalloc(strlen(data->hostname) + 1, GFP_KERNEL);
441 	if (!server->hostname)
442 		return -ENOMEM;
443 	strcpy(server->hostname, data->hostname);
444 
445 	/* Check NFS protocol revision and initialize RPC op vector
446 	 * and file handle pool. */
447 #ifdef CONFIG_NFS_V3
448 	if (server->flags & NFS_MOUNT_VER3) {
449 		server->rpc_ops = &nfs_v3_clientops;
450 		server->caps |= NFS_CAP_READDIRPLUS;
451 	} else {
452 		server->rpc_ops = &nfs_v2_clientops;
453 	}
454 #else
455 	server->rpc_ops = &nfs_v2_clientops;
456 #endif
457 
458 	/* Fill in pseudoflavor for mount version < 5 */
459 	if (!(data->flags & NFS_MOUNT_SECFLAVOUR))
460 		data->pseudoflavor = RPC_AUTH_UNIX;
461 	authflavor = data->pseudoflavor;	/* save for sb_init() */
462 	/* XXX maybe we want to add a server->pseudoflavor field */
463 
464 	/* Create RPC client handles */
465 	server->client = nfs_create_client(server, data);
466 	if (IS_ERR(server->client))
467 		return PTR_ERR(server->client);
468 	/* RFC 2623, sec 2.3.2 */
469 	if (authflavor != RPC_AUTH_UNIX) {
470 		struct rpc_auth *auth;
471 
472 		server->client_sys = rpc_clone_client(server->client);
473 		if (IS_ERR(server->client_sys))
474 			return PTR_ERR(server->client_sys);
475 		auth = rpcauth_create(RPC_AUTH_UNIX, server->client_sys);
476 		if (IS_ERR(auth))
477 			return PTR_ERR(auth);
478 	} else {
479 		atomic_inc(&server->client->cl_count);
480 		server->client_sys = server->client;
481 	}
482 	if (server->flags & NFS_MOUNT_VER3) {
483 #ifdef CONFIG_NFS_V3_ACL
484 		if (!(server->flags & NFS_MOUNT_NOACL)) {
485 			server->client_acl = rpc_bind_new_program(server->client, &nfsacl_program, 3);
486 			/* No errors! Assume that Sun nfsacls are supported */
487 			if (!IS_ERR(server->client_acl))
488 				server->caps |= NFS_CAP_ACLS;
489 		}
490 #else
491 		server->flags &= ~NFS_MOUNT_NOACL;
492 #endif /* CONFIG_NFS_V3_ACL */
493 		/*
494 		 * The VFS shouldn't apply the umask to mode bits. We will
495 		 * do so ourselves when necessary.
496 		 */
497 		sb->s_flags |= MS_POSIXACL;
498 		if (server->namelen == 0 || server->namelen > NFS3_MAXNAMLEN)
499 			server->namelen = NFS3_MAXNAMLEN;
500 		sb->s_time_gran = 1;
501 	} else {
502 		if (server->namelen == 0 || server->namelen > NFS2_MAXNAMLEN)
503 			server->namelen = NFS2_MAXNAMLEN;
504 	}
505 
506 	sb->s_op = &nfs_sops;
507 	return nfs_sb_init(sb, authflavor);
508 }
509 
510 static int
511 nfs_statfs(struct super_block *sb, struct kstatfs *buf)
512 {
513 	struct nfs_server *server = NFS_SB(sb);
514 	unsigned char blockbits;
515 	unsigned long blockres;
516 	struct nfs_fh *rootfh = NFS_FH(sb->s_root->d_inode);
517 	struct nfs_fattr fattr;
518 	struct nfs_fsstat res = {
519 			.fattr = &fattr,
520 	};
521 	int error;
522 
523 	lock_kernel();
524 
525 	error = server->rpc_ops->statfs(server, rootfh, &res);
526 	buf->f_type = NFS_SUPER_MAGIC;
527 	if (error < 0)
528 		goto out_err;
529 
530 	/*
531 	 * Current versions of glibc do not correctly handle the
532 	 * case where f_frsize != f_bsize.  Eventually we want to
533 	 * report the value of wtmult in this field.
534 	 */
535 	buf->f_frsize = sb->s_blocksize;
536 
537 	/*
538 	 * On most *nix systems, f_blocks, f_bfree, and f_bavail
539 	 * are reported in units of f_frsize.  Linux hasn't had
540 	 * an f_frsize field in its statfs struct until recently,
541 	 * thus historically Linux's sys_statfs reports these
542 	 * fields in units of f_bsize.
543 	 */
544 	buf->f_bsize = sb->s_blocksize;
545 	blockbits = sb->s_blocksize_bits;
546 	blockres = (1 << blockbits) - 1;
547 	buf->f_blocks = (res.tbytes + blockres) >> blockbits;
548 	buf->f_bfree = (res.fbytes + blockres) >> blockbits;
549 	buf->f_bavail = (res.abytes + blockres) >> blockbits;
550 
551 	buf->f_files = res.tfiles;
552 	buf->f_ffree = res.afiles;
553 
554 	buf->f_namelen = server->namelen;
555  out:
556 	unlock_kernel();
557 
558 	return 0;
559 
560  out_err:
561 	printk(KERN_WARNING "nfs_statfs: statfs error = %d\n", -error);
562 	buf->f_bsize = buf->f_blocks = buf->f_bfree = buf->f_bavail = -1;
563 	goto out;
564 
565 }
566 
567 static int nfs_show_options(struct seq_file *m, struct vfsmount *mnt)
568 {
569 	static struct proc_nfs_info {
570 		int flag;
571 		char *str;
572 		char *nostr;
573 	} nfs_info[] = {
574 		{ NFS_MOUNT_SOFT, ",soft", ",hard" },
575 		{ NFS_MOUNT_INTR, ",intr", "" },
576 		{ NFS_MOUNT_POSIX, ",posix", "" },
577 		{ NFS_MOUNT_TCP, ",tcp", ",udp" },
578 		{ NFS_MOUNT_NOCTO, ",nocto", "" },
579 		{ NFS_MOUNT_NOAC, ",noac", "" },
580 		{ NFS_MOUNT_NONLM, ",nolock", ",lock" },
581 		{ NFS_MOUNT_NOACL, ",noacl", "" },
582 		{ 0, NULL, NULL }
583 	};
584 	struct proc_nfs_info *nfs_infop;
585 	struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
586 
587 	seq_printf(m, ",v%d", nfss->rpc_ops->version);
588 	seq_printf(m, ",rsize=%d", nfss->rsize);
589 	seq_printf(m, ",wsize=%d", nfss->wsize);
590 	if (nfss->acregmin != 3*HZ)
591 		seq_printf(m, ",acregmin=%d", nfss->acregmin/HZ);
592 	if (nfss->acregmax != 60*HZ)
593 		seq_printf(m, ",acregmax=%d", nfss->acregmax/HZ);
594 	if (nfss->acdirmin != 30*HZ)
595 		seq_printf(m, ",acdirmin=%d", nfss->acdirmin/HZ);
596 	if (nfss->acdirmax != 60*HZ)
597 		seq_printf(m, ",acdirmax=%d", nfss->acdirmax/HZ);
598 	for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
599 		if (nfss->flags & nfs_infop->flag)
600 			seq_puts(m, nfs_infop->str);
601 		else
602 			seq_puts(m, nfs_infop->nostr);
603 	}
604 	seq_puts(m, ",addr=");
605 	seq_escape(m, nfss->hostname, " \t\n\\");
606 	return 0;
607 }
608 
609 /*
610  * Invalidate the local caches
611  */
612 void
613 nfs_zap_caches(struct inode *inode)
614 {
615 	struct nfs_inode *nfsi = NFS_I(inode);
616 	int mode = inode->i_mode;
617 
618 	spin_lock(&inode->i_lock);
619 
620 	NFS_ATTRTIMEO(inode) = NFS_MINATTRTIMEO(inode);
621 	NFS_ATTRTIMEO_UPDATE(inode) = jiffies;
622 
623 	memset(NFS_COOKIEVERF(inode), 0, sizeof(NFS_COOKIEVERF(inode)));
624 	if (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))
625 		nfsi->cache_validity |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL|NFS_INO_REVAL_PAGECACHE;
626 	else
627 		nfsi->cache_validity |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL|NFS_INO_REVAL_PAGECACHE;
628 
629 	spin_unlock(&inode->i_lock);
630 }
631 
632 static void nfs_zap_acl_cache(struct inode *inode)
633 {
634 	void (*clear_acl_cache)(struct inode *);
635 
636 	clear_acl_cache = NFS_PROTO(inode)->clear_acl_cache;
637 	if (clear_acl_cache != NULL)
638 		clear_acl_cache(inode);
639 	spin_lock(&inode->i_lock);
640 	NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_ACL;
641 	spin_unlock(&inode->i_lock);
642 }
643 
644 /*
645  * Invalidate, but do not unhash, the inode
646  */
647 static void
648 nfs_invalidate_inode(struct inode *inode)
649 {
650 	umode_t save_mode = inode->i_mode;
651 
652 	make_bad_inode(inode);
653 	inode->i_mode = save_mode;
654 	nfs_zap_caches(inode);
655 }
656 
657 struct nfs_find_desc {
658 	struct nfs_fh		*fh;
659 	struct nfs_fattr	*fattr;
660 };
661 
662 /*
663  * In NFSv3 we can have 64bit inode numbers. In order to support
664  * this, and re-exported directories (also seen in NFSv2)
665  * we are forced to allow 2 different inodes to have the same
666  * i_ino.
667  */
668 static int
669 nfs_find_actor(struct inode *inode, void *opaque)
670 {
671 	struct nfs_find_desc	*desc = (struct nfs_find_desc *)opaque;
672 	struct nfs_fh		*fh = desc->fh;
673 	struct nfs_fattr	*fattr = desc->fattr;
674 
675 	if (NFS_FILEID(inode) != fattr->fileid)
676 		return 0;
677 	if (nfs_compare_fh(NFS_FH(inode), fh))
678 		return 0;
679 	if (is_bad_inode(inode) || NFS_STALE(inode))
680 		return 0;
681 	return 1;
682 }
683 
684 static int
685 nfs_init_locked(struct inode *inode, void *opaque)
686 {
687 	struct nfs_find_desc	*desc = (struct nfs_find_desc *)opaque;
688 	struct nfs_fattr	*fattr = desc->fattr;
689 
690 	NFS_FILEID(inode) = fattr->fileid;
691 	nfs_copy_fh(NFS_FH(inode), desc->fh);
692 	return 0;
693 }
694 
695 /* Don't use READDIRPLUS on directories that we believe are too large */
696 #define NFS_LIMIT_READDIRPLUS (8*PAGE_SIZE)
697 
698 /*
699  * This is our front-end to iget that looks up inodes by file handle
700  * instead of inode number.
701  */
702 struct inode *
703 nfs_fhget(struct super_block *sb, struct nfs_fh *fh, struct nfs_fattr *fattr)
704 {
705 	struct nfs_find_desc desc = {
706 		.fh	= fh,
707 		.fattr	= fattr
708 	};
709 	struct inode *inode = NULL;
710 	unsigned long hash;
711 
712 	if ((fattr->valid & NFS_ATTR_FATTR) == 0)
713 		goto out_no_inode;
714 
715 	if (!fattr->nlink) {
716 		printk("NFS: Buggy server - nlink == 0!\n");
717 		goto out_no_inode;
718 	}
719 
720 	hash = nfs_fattr_to_ino_t(fattr);
721 
722 	if (!(inode = iget5_locked(sb, hash, nfs_find_actor, nfs_init_locked, &desc)))
723 		goto out_no_inode;
724 
725 	if (inode->i_state & I_NEW) {
726 		struct nfs_inode *nfsi = NFS_I(inode);
727 
728 		/* We set i_ino for the few things that still rely on it,
729 		 * such as stat(2) */
730 		inode->i_ino = hash;
731 
732 		/* We can't support update_atime(), since the server will reset it */
733 		inode->i_flags |= S_NOATIME|S_NOCMTIME;
734 		inode->i_mode = fattr->mode;
735 		/* Why so? Because we want revalidate for devices/FIFOs, and
736 		 * that's precisely what we have in nfs_file_inode_operations.
737 		 */
738 		inode->i_op = NFS_SB(sb)->rpc_ops->file_inode_ops;
739 		if (S_ISREG(inode->i_mode)) {
740 			inode->i_fop = &nfs_file_operations;
741 			inode->i_data.a_ops = &nfs_file_aops;
742 			inode->i_data.backing_dev_info = &NFS_SB(sb)->backing_dev_info;
743 		} else if (S_ISDIR(inode->i_mode)) {
744 			inode->i_op = NFS_SB(sb)->rpc_ops->dir_inode_ops;
745 			inode->i_fop = &nfs_dir_operations;
746 			if (nfs_server_capable(inode, NFS_CAP_READDIRPLUS)
747 			    && fattr->size <= NFS_LIMIT_READDIRPLUS)
748 				set_bit(NFS_INO_ADVISE_RDPLUS, &NFS_FLAGS(inode));
749 		} else if (S_ISLNK(inode->i_mode))
750 			inode->i_op = &nfs_symlink_inode_operations;
751 		else
752 			init_special_inode(inode, inode->i_mode, fattr->rdev);
753 
754 		nfsi->read_cache_jiffies = fattr->timestamp;
755 		inode->i_atime = fattr->atime;
756 		inode->i_mtime = fattr->mtime;
757 		inode->i_ctime = fattr->ctime;
758 		if (fattr->valid & NFS_ATTR_FATTR_V4)
759 			nfsi->change_attr = fattr->change_attr;
760 		inode->i_size = nfs_size_to_loff_t(fattr->size);
761 		inode->i_nlink = fattr->nlink;
762 		inode->i_uid = fattr->uid;
763 		inode->i_gid = fattr->gid;
764 		if (fattr->valid & (NFS_ATTR_FATTR_V3 | NFS_ATTR_FATTR_V4)) {
765 			/*
766 			 * report the blocks in 512byte units
767 			 */
768 			inode->i_blocks = nfs_calc_block_size(fattr->du.nfs3.used);
769 			inode->i_blksize = inode->i_sb->s_blocksize;
770 		} else {
771 			inode->i_blocks = fattr->du.nfs2.blocks;
772 			inode->i_blksize = fattr->du.nfs2.blocksize;
773 		}
774 		nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
775 		nfsi->attrtimeo_timestamp = jiffies;
776 		memset(nfsi->cookieverf, 0, sizeof(nfsi->cookieverf));
777 		nfsi->cache_access.cred = NULL;
778 
779 		unlock_new_inode(inode);
780 	} else
781 		nfs_refresh_inode(inode, fattr);
782 	dprintk("NFS: nfs_fhget(%s/%Ld ct=%d)\n",
783 		inode->i_sb->s_id,
784 		(long long)NFS_FILEID(inode),
785 		atomic_read(&inode->i_count));
786 
787 out:
788 	return inode;
789 
790 out_no_inode:
791 	printk("nfs_fhget: iget failed\n");
792 	goto out;
793 }
794 
795 #define NFS_VALID_ATTRS (ATTR_MODE|ATTR_UID|ATTR_GID|ATTR_SIZE|ATTR_ATIME|ATTR_ATIME_SET|ATTR_MTIME|ATTR_MTIME_SET)
796 
797 int
798 nfs_setattr(struct dentry *dentry, struct iattr *attr)
799 {
800 	struct inode *inode = dentry->d_inode;
801 	struct nfs_fattr fattr;
802 	int error;
803 
804 	if (attr->ia_valid & ATTR_SIZE) {
805 		if (!S_ISREG(inode->i_mode) || attr->ia_size == i_size_read(inode))
806 			attr->ia_valid &= ~ATTR_SIZE;
807 	}
808 
809 	/* Optimization: if the end result is no change, don't RPC */
810 	attr->ia_valid &= NFS_VALID_ATTRS;
811 	if (attr->ia_valid == 0)
812 		return 0;
813 
814 	lock_kernel();
815 	nfs_begin_data_update(inode);
816 	/* Write all dirty data if we're changing file permissions or size */
817 	if ((attr->ia_valid & (ATTR_MODE|ATTR_UID|ATTR_GID|ATTR_SIZE)) != 0) {
818 		if (filemap_fdatawrite(inode->i_mapping) == 0)
819 			filemap_fdatawait(inode->i_mapping);
820 		nfs_wb_all(inode);
821 	}
822 	error = NFS_PROTO(inode)->setattr(dentry, &fattr, attr);
823 	if (error == 0)
824 		nfs_refresh_inode(inode, &fattr);
825 	nfs_end_data_update(inode);
826 	unlock_kernel();
827 	return error;
828 }
829 
830 /**
831  * nfs_setattr_update_inode - Update inode metadata after a setattr call.
832  * @inode: pointer to struct inode
833  * @attr: pointer to struct iattr
834  *
835  * Note: we do this in the *proc.c in order to ensure that
836  *       it works for things like exclusive creates too.
837  */
838 void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr)
839 {
840 	if ((attr->ia_valid & (ATTR_MODE|ATTR_UID|ATTR_GID)) != 0) {
841 		if ((attr->ia_valid & ATTR_MODE) != 0) {
842 			int mode = attr->ia_mode & S_IALLUGO;
843 			mode |= inode->i_mode & ~S_IALLUGO;
844 			inode->i_mode = mode;
845 		}
846 		if ((attr->ia_valid & ATTR_UID) != 0)
847 			inode->i_uid = attr->ia_uid;
848 		if ((attr->ia_valid & ATTR_GID) != 0)
849 			inode->i_gid = attr->ia_gid;
850 		spin_lock(&inode->i_lock);
851 		NFS_I(inode)->cache_validity |= NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
852 		spin_unlock(&inode->i_lock);
853 	}
854 	if ((attr->ia_valid & ATTR_SIZE) != 0) {
855 		inode->i_size = attr->ia_size;
856 		vmtruncate(inode, attr->ia_size);
857 	}
858 }
859 
860 static int nfs_wait_schedule(void *word)
861 {
862 	if (signal_pending(current))
863 		return -ERESTARTSYS;
864 	schedule();
865 	return 0;
866 }
867 
868 /*
869  * Wait for the inode to get unlocked.
870  */
871 static int nfs_wait_on_inode(struct inode *inode)
872 {
873 	struct rpc_clnt	*clnt = NFS_CLIENT(inode);
874 	struct nfs_inode *nfsi = NFS_I(inode);
875 	sigset_t oldmask;
876 	int error;
877 
878 	atomic_inc(&inode->i_count);
879 	rpc_clnt_sigmask(clnt, &oldmask);
880 	error = wait_on_bit_lock(&nfsi->flags, NFS_INO_REVALIDATING,
881 					nfs_wait_schedule, TASK_INTERRUPTIBLE);
882 	rpc_clnt_sigunmask(clnt, &oldmask);
883 	iput(inode);
884 
885 	return error;
886 }
887 
888 static void nfs_wake_up_inode(struct inode *inode)
889 {
890 	struct nfs_inode *nfsi = NFS_I(inode);
891 
892 	clear_bit(NFS_INO_REVALIDATING, &nfsi->flags);
893 	smp_mb__after_clear_bit();
894 	wake_up_bit(&nfsi->flags, NFS_INO_REVALIDATING);
895 }
896 
897 int nfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
898 {
899 	struct inode *inode = dentry->d_inode;
900 	int need_atime = NFS_I(inode)->cache_validity & NFS_INO_INVALID_ATIME;
901 	int err;
902 
903 	if (__IS_FLG(inode, MS_NOATIME))
904 		need_atime = 0;
905 	else if (__IS_FLG(inode, MS_NODIRATIME) && S_ISDIR(inode->i_mode))
906 		need_atime = 0;
907 	/* We may force a getattr if the user cares about atime */
908 	if (need_atime)
909 		err = __nfs_revalidate_inode(NFS_SERVER(inode), inode);
910 	else
911 		err = nfs_revalidate_inode(NFS_SERVER(inode), inode);
912 	if (!err)
913 		generic_fillattr(inode, stat);
914 	return err;
915 }
916 
917 struct nfs_open_context *alloc_nfs_open_context(struct dentry *dentry, struct rpc_cred *cred)
918 {
919 	struct nfs_open_context *ctx;
920 
921 	ctx = (struct nfs_open_context *)kmalloc(sizeof(*ctx), GFP_KERNEL);
922 	if (ctx != NULL) {
923 		atomic_set(&ctx->count, 1);
924 		ctx->dentry = dget(dentry);
925 		ctx->cred = get_rpccred(cred);
926 		ctx->state = NULL;
927 		ctx->lockowner = current->files;
928 		ctx->error = 0;
929 		ctx->dir_cookie = 0;
930 	}
931 	return ctx;
932 }
933 
934 struct nfs_open_context *get_nfs_open_context(struct nfs_open_context *ctx)
935 {
936 	if (ctx != NULL)
937 		atomic_inc(&ctx->count);
938 	return ctx;
939 }
940 
941 void put_nfs_open_context(struct nfs_open_context *ctx)
942 {
943 	if (atomic_dec_and_test(&ctx->count)) {
944 		if (!list_empty(&ctx->list)) {
945 			struct inode *inode = ctx->dentry->d_inode;
946 			spin_lock(&inode->i_lock);
947 			list_del(&ctx->list);
948 			spin_unlock(&inode->i_lock);
949 		}
950 		if (ctx->state != NULL)
951 			nfs4_close_state(ctx->state, ctx->mode);
952 		if (ctx->cred != NULL)
953 			put_rpccred(ctx->cred);
954 		dput(ctx->dentry);
955 		kfree(ctx);
956 	}
957 }
958 
959 /*
960  * Ensure that mmap has a recent RPC credential for use when writing out
961  * shared pages
962  */
963 void nfs_file_set_open_context(struct file *filp, struct nfs_open_context *ctx)
964 {
965 	struct inode *inode = filp->f_dentry->d_inode;
966 	struct nfs_inode *nfsi = NFS_I(inode);
967 
968 	filp->private_data = get_nfs_open_context(ctx);
969 	spin_lock(&inode->i_lock);
970 	list_add(&ctx->list, &nfsi->open_files);
971 	spin_unlock(&inode->i_lock);
972 }
973 
974 struct nfs_open_context *nfs_find_open_context(struct inode *inode, int mode)
975 {
976 	struct nfs_inode *nfsi = NFS_I(inode);
977 	struct nfs_open_context *pos, *ctx = NULL;
978 
979 	spin_lock(&inode->i_lock);
980 	list_for_each_entry(pos, &nfsi->open_files, list) {
981 		if ((pos->mode & mode) == mode) {
982 			ctx = get_nfs_open_context(pos);
983 			break;
984 		}
985 	}
986 	spin_unlock(&inode->i_lock);
987 	return ctx;
988 }
989 
990 void nfs_file_clear_open_context(struct file *filp)
991 {
992 	struct inode *inode = filp->f_dentry->d_inode;
993 	struct nfs_open_context *ctx = (struct nfs_open_context *)filp->private_data;
994 
995 	if (ctx) {
996 		filp->private_data = NULL;
997 		spin_lock(&inode->i_lock);
998 		list_move_tail(&ctx->list, &NFS_I(inode)->open_files);
999 		spin_unlock(&inode->i_lock);
1000 		put_nfs_open_context(ctx);
1001 	}
1002 }
1003 
1004 /*
1005  * These allocate and release file read/write context information.
1006  */
1007 int nfs_open(struct inode *inode, struct file *filp)
1008 {
1009 	struct nfs_open_context *ctx;
1010 	struct rpc_cred *cred;
1011 
1012 	cred = rpcauth_lookupcred(NFS_CLIENT(inode)->cl_auth, 0);
1013 	if (IS_ERR(cred))
1014 		return PTR_ERR(cred);
1015 	ctx = alloc_nfs_open_context(filp->f_dentry, cred);
1016 	put_rpccred(cred);
1017 	if (ctx == NULL)
1018 		return -ENOMEM;
1019 	ctx->mode = filp->f_mode;
1020 	nfs_file_set_open_context(filp, ctx);
1021 	put_nfs_open_context(ctx);
1022 	if ((filp->f_mode & FMODE_WRITE) != 0)
1023 		nfs_begin_data_update(inode);
1024 	return 0;
1025 }
1026 
1027 int nfs_release(struct inode *inode, struct file *filp)
1028 {
1029 	if ((filp->f_mode & FMODE_WRITE) != 0)
1030 		nfs_end_data_update(inode);
1031 	nfs_file_clear_open_context(filp);
1032 	return 0;
1033 }
1034 
1035 /*
1036  * This function is called whenever some part of NFS notices that
1037  * the cached attributes have to be refreshed.
1038  */
1039 int
1040 __nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
1041 {
1042 	int		 status = -ESTALE;
1043 	struct nfs_fattr fattr;
1044 	struct nfs_inode *nfsi = NFS_I(inode);
1045 	unsigned long verifier;
1046 	unsigned long cache_validity;
1047 
1048 	dfprintk(PAGECACHE, "NFS: revalidating (%s/%Ld)\n",
1049 		inode->i_sb->s_id, (long long)NFS_FILEID(inode));
1050 
1051 	lock_kernel();
1052 	if (!inode || is_bad_inode(inode))
1053  		goto out_nowait;
1054 	if (NFS_STALE(inode))
1055  		goto out_nowait;
1056 
1057 	status = nfs_wait_on_inode(inode);
1058 	if (status < 0)
1059 		goto out;
1060 	if (NFS_STALE(inode)) {
1061 		status = -ESTALE;
1062 		/* Do we trust the cached ESTALE? */
1063 		if (NFS_ATTRTIMEO(inode) != 0) {
1064 			if (nfsi->cache_validity & (NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA|NFS_INO_INVALID_ATIME)) {
1065 				/* no */
1066 			} else
1067 				goto out;
1068 		}
1069 	}
1070 
1071 	/* Protect against RPC races by saving the change attribute */
1072 	verifier = nfs_save_change_attribute(inode);
1073 	status = NFS_PROTO(inode)->getattr(server, NFS_FH(inode), &fattr);
1074 	if (status != 0) {
1075 		dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Ld) getattr failed, error=%d\n",
1076 			 inode->i_sb->s_id,
1077 			 (long long)NFS_FILEID(inode), status);
1078 		if (status == -ESTALE) {
1079 			nfs_zap_caches(inode);
1080 			if (!S_ISDIR(inode->i_mode))
1081 				set_bit(NFS_INO_STALE, &NFS_FLAGS(inode));
1082 		}
1083 		goto out;
1084 	}
1085 
1086 	status = nfs_update_inode(inode, &fattr, verifier);
1087 	if (status) {
1088 		dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Ld) refresh failed, error=%d\n",
1089 			 inode->i_sb->s_id,
1090 			 (long long)NFS_FILEID(inode), status);
1091 		goto out;
1092 	}
1093 	spin_lock(&inode->i_lock);
1094 	cache_validity = nfsi->cache_validity;
1095 	nfsi->cache_validity &= ~NFS_INO_REVAL_PAGECACHE;
1096 
1097 	/*
1098 	 * We may need to keep the attributes marked as invalid if
1099 	 * we raced with nfs_end_attr_update().
1100 	 */
1101 	if (verifier == nfsi->cache_change_attribute)
1102 		nfsi->cache_validity &= ~(NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ATIME);
1103 	spin_unlock(&inode->i_lock);
1104 
1105 	nfs_revalidate_mapping(inode, inode->i_mapping);
1106 
1107 	if (cache_validity & NFS_INO_INVALID_ACL)
1108 		nfs_zap_acl_cache(inode);
1109 
1110 	dfprintk(PAGECACHE, "NFS: (%s/%Ld) revalidation complete\n",
1111 		inode->i_sb->s_id,
1112 		(long long)NFS_FILEID(inode));
1113 
1114  out:
1115 	nfs_wake_up_inode(inode);
1116 
1117  out_nowait:
1118 	unlock_kernel();
1119 	return status;
1120 }
1121 
1122 int nfs_attribute_timeout(struct inode *inode)
1123 {
1124 	struct nfs_inode *nfsi = NFS_I(inode);
1125 
1126 	if (nfs_have_delegation(inode, FMODE_READ))
1127 		return 0;
1128 	return time_after(jiffies, nfsi->read_cache_jiffies+nfsi->attrtimeo);
1129 }
1130 
1131 /**
1132  * nfs_revalidate_inode - Revalidate the inode attributes
1133  * @server - pointer to nfs_server struct
1134  * @inode - pointer to inode struct
1135  *
1136  * Updates inode attribute information by retrieving the data from the server.
1137  */
1138 int nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
1139 {
1140 	if (!(NFS_I(inode)->cache_validity & (NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA))
1141 			&& !nfs_attribute_timeout(inode))
1142 		return NFS_STALE(inode) ? -ESTALE : 0;
1143 	return __nfs_revalidate_inode(server, inode);
1144 }
1145 
1146 /**
1147  * nfs_revalidate_mapping - Revalidate the pagecache
1148  * @inode - pointer to host inode
1149  * @mapping - pointer to mapping
1150  */
1151 void nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping)
1152 {
1153 	struct nfs_inode *nfsi = NFS_I(inode);
1154 
1155 	if (nfsi->cache_validity & NFS_INO_INVALID_DATA) {
1156 		if (S_ISREG(inode->i_mode)) {
1157 			if (filemap_fdatawrite(mapping) == 0)
1158 				filemap_fdatawait(mapping);
1159 			nfs_wb_all(inode);
1160 		}
1161 		invalidate_inode_pages2(mapping);
1162 
1163 		spin_lock(&inode->i_lock);
1164 		nfsi->cache_validity &= ~NFS_INO_INVALID_DATA;
1165 		if (S_ISDIR(inode->i_mode)) {
1166 			memset(nfsi->cookieverf, 0, sizeof(nfsi->cookieverf));
1167 			/* This ensures we revalidate child dentries */
1168 			nfsi->cache_change_attribute++;
1169 		}
1170 		spin_unlock(&inode->i_lock);
1171 
1172 		dfprintk(PAGECACHE, "NFS: (%s/%Ld) data cache invalidated\n",
1173 				inode->i_sb->s_id,
1174 				(long long)NFS_FILEID(inode));
1175 	}
1176 }
1177 
1178 /**
1179  * nfs_begin_data_update
1180  * @inode - pointer to inode
1181  * Declare that a set of operations will update file data on the server
1182  */
1183 void nfs_begin_data_update(struct inode *inode)
1184 {
1185 	atomic_inc(&NFS_I(inode)->data_updates);
1186 }
1187 
1188 /**
1189  * nfs_end_data_update
1190  * @inode - pointer to inode
1191  * Declare end of the operations that will update file data
1192  * This will mark the inode as immediately needing revalidation
1193  * of its attribute cache.
1194  */
1195 void nfs_end_data_update(struct inode *inode)
1196 {
1197 	struct nfs_inode *nfsi = NFS_I(inode);
1198 
1199 	if (!nfs_have_delegation(inode, FMODE_READ)) {
1200 		/* Mark the attribute cache for revalidation */
1201 		spin_lock(&inode->i_lock);
1202 		nfsi->cache_validity |= NFS_INO_INVALID_ATTR;
1203 		/* Directories and symlinks: invalidate page cache too */
1204 		if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
1205 			nfsi->cache_validity |= NFS_INO_INVALID_DATA;
1206 		spin_unlock(&inode->i_lock);
1207 	}
1208 	nfsi->cache_change_attribute ++;
1209 	atomic_dec(&nfsi->data_updates);
1210 }
1211 
1212 /**
1213  * nfs_refresh_inode - verify consistency of the inode attribute cache
1214  * @inode - pointer to inode
1215  * @fattr - updated attributes
1216  *
1217  * Verifies the attribute cache. If we have just changed the attributes,
1218  * so that fattr carries weak cache consistency data, then it may
1219  * also update the ctime/mtime/change_attribute.
1220  */
1221 int nfs_refresh_inode(struct inode *inode, struct nfs_fattr *fattr)
1222 {
1223 	struct nfs_inode *nfsi = NFS_I(inode);
1224 	loff_t cur_size, new_isize;
1225 	int data_unstable;
1226 
1227 	/* Do we hold a delegation? */
1228 	if (nfs_have_delegation(inode, FMODE_READ))
1229 		return 0;
1230 
1231 	spin_lock(&inode->i_lock);
1232 
1233 	/* Are we in the process of updating data on the server? */
1234 	data_unstable = nfs_caches_unstable(inode);
1235 
1236 	if (fattr->valid & NFS_ATTR_FATTR_V4) {
1237 		if ((fattr->valid & NFS_ATTR_PRE_CHANGE) != 0
1238 				&& nfsi->change_attr == fattr->pre_change_attr)
1239 			nfsi->change_attr = fattr->change_attr;
1240 		if (nfsi->change_attr != fattr->change_attr) {
1241 			nfsi->cache_validity |= NFS_INO_INVALID_ATTR;
1242 			if (!data_unstable)
1243 				nfsi->cache_validity |= NFS_INO_REVAL_PAGECACHE;
1244 		}
1245 	}
1246 
1247 	if ((fattr->valid & NFS_ATTR_FATTR) == 0) {
1248 		spin_unlock(&inode->i_lock);
1249 		return 0;
1250 	}
1251 
1252 	/* Has the inode gone and changed behind our back? */
1253 	if (nfsi->fileid != fattr->fileid
1254 			|| (inode->i_mode & S_IFMT) != (fattr->mode & S_IFMT)) {
1255 		spin_unlock(&inode->i_lock);
1256 		return -EIO;
1257 	}
1258 
1259 	cur_size = i_size_read(inode);
1260  	new_isize = nfs_size_to_loff_t(fattr->size);
1261 
1262 	/* If we have atomic WCC data, we may update some attributes */
1263 	if ((fattr->valid & NFS_ATTR_WCC) != 0) {
1264 		if (timespec_equal(&inode->i_ctime, &fattr->pre_ctime))
1265 			memcpy(&inode->i_ctime, &fattr->ctime, sizeof(inode->i_ctime));
1266 		if (timespec_equal(&inode->i_mtime, &fattr->pre_mtime))
1267 			memcpy(&inode->i_mtime, &fattr->mtime, sizeof(inode->i_mtime));
1268 	}
1269 
1270 	/* Verify a few of the more important attributes */
1271 	if (!timespec_equal(&inode->i_mtime, &fattr->mtime)) {
1272 		nfsi->cache_validity |= NFS_INO_INVALID_ATTR;
1273 		if (!data_unstable)
1274 			nfsi->cache_validity |= NFS_INO_REVAL_PAGECACHE;
1275 	}
1276 	if (cur_size != new_isize) {
1277 		nfsi->cache_validity |= NFS_INO_INVALID_ATTR;
1278 		if (nfsi->npages == 0)
1279 			nfsi->cache_validity |= NFS_INO_REVAL_PAGECACHE;
1280 	}
1281 
1282 	/* Have any file permissions changed? */
1283 	if ((inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO)
1284 			|| inode->i_uid != fattr->uid
1285 			|| inode->i_gid != fattr->gid)
1286 		nfsi->cache_validity |= NFS_INO_INVALID_ATTR | NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL;
1287 
1288 	/* Has the link count changed? */
1289 	if (inode->i_nlink != fattr->nlink)
1290 		nfsi->cache_validity |= NFS_INO_INVALID_ATTR;
1291 
1292 	if (!timespec_equal(&inode->i_atime, &fattr->atime))
1293 		nfsi->cache_validity |= NFS_INO_INVALID_ATIME;
1294 
1295 	nfsi->read_cache_jiffies = fattr->timestamp;
1296 	spin_unlock(&inode->i_lock);
1297 	return 0;
1298 }
1299 
1300 /*
1301  * Many nfs protocol calls return the new file attributes after
1302  * an operation.  Here we update the inode to reflect the state
1303  * of the server's inode.
1304  *
1305  * This is a bit tricky because we have to make sure all dirty pages
1306  * have been sent off to the server before calling invalidate_inode_pages.
1307  * To make sure no other process adds more write requests while we try
1308  * our best to flush them, we make them sleep during the attribute refresh.
1309  *
1310  * A very similar scenario holds for the dir cache.
1311  */
1312 static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr, unsigned long verifier)
1313 {
1314 	struct nfs_inode *nfsi = NFS_I(inode);
1315 	loff_t cur_isize, new_isize;
1316 	unsigned int	invalid = 0;
1317 	int data_unstable;
1318 
1319 	dfprintk(VFS, "NFS: %s(%s/%ld ct=%d info=0x%x)\n",
1320 			__FUNCTION__, inode->i_sb->s_id, inode->i_ino,
1321 			atomic_read(&inode->i_count), fattr->valid);
1322 
1323 	if ((fattr->valid & NFS_ATTR_FATTR) == 0)
1324 		return 0;
1325 
1326 	if (nfsi->fileid != fattr->fileid) {
1327 		printk(KERN_ERR "%s: inode number mismatch\n"
1328 		       "expected (%s/0x%Lx), got (%s/0x%Lx)\n",
1329 		       __FUNCTION__,
1330 		       inode->i_sb->s_id, (long long)nfsi->fileid,
1331 		       inode->i_sb->s_id, (long long)fattr->fileid);
1332 		goto out_err;
1333 	}
1334 
1335 	spin_lock(&inode->i_lock);
1336 
1337 	/*
1338 	 * Make sure the inode's type hasn't changed.
1339 	 */
1340 	if ((inode->i_mode & S_IFMT) != (fattr->mode & S_IFMT)) {
1341 		spin_unlock(&inode->i_lock);
1342 		goto out_changed;
1343 	}
1344 
1345 	/*
1346 	 * Update the read time so we don't revalidate too often.
1347 	 */
1348 	nfsi->read_cache_jiffies = fattr->timestamp;
1349 
1350 	/* Are we racing with known updates of the metadata on the server? */
1351 	data_unstable = ! nfs_verify_change_attribute(inode, verifier);
1352 
1353 	/* Check if our cached file size is stale */
1354  	new_isize = nfs_size_to_loff_t(fattr->size);
1355 	cur_isize = i_size_read(inode);
1356 	if (new_isize != cur_isize) {
1357 		/* Do we perhaps have any outstanding writes? */
1358 		if (nfsi->npages == 0) {
1359 			/* No, but did we race with nfs_end_data_update()? */
1360 			if (verifier  ==  nfsi->cache_change_attribute) {
1361 				inode->i_size = new_isize;
1362 				invalid |= NFS_INO_INVALID_DATA;
1363 			}
1364 			invalid |= NFS_INO_INVALID_ATTR;
1365 		} else if (new_isize > cur_isize) {
1366 			inode->i_size = new_isize;
1367 			invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA;
1368 		}
1369 		dprintk("NFS: isize change on server for file %s/%ld\n",
1370 				inode->i_sb->s_id, inode->i_ino);
1371 	}
1372 
1373 	/* Check if the mtime agrees */
1374 	if (!timespec_equal(&inode->i_mtime, &fattr->mtime)) {
1375 		memcpy(&inode->i_mtime, &fattr->mtime, sizeof(inode->i_mtime));
1376 		dprintk("NFS: mtime change on server for file %s/%ld\n",
1377 				inode->i_sb->s_id, inode->i_ino);
1378 		if (!data_unstable)
1379 			invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA;
1380 	}
1381 
1382 	if ((fattr->valid & NFS_ATTR_FATTR_V4)
1383 	    && nfsi->change_attr != fattr->change_attr) {
1384 		dprintk("NFS: change_attr change on server for file %s/%ld\n",
1385 		       inode->i_sb->s_id, inode->i_ino);
1386 		nfsi->change_attr = fattr->change_attr;
1387 		if (!data_unstable)
1388 			invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1389 	}
1390 
1391 	/* If ctime has changed we should definitely clear access+acl caches */
1392 	if (!timespec_equal(&inode->i_ctime, &fattr->ctime)) {
1393 		if (!data_unstable)
1394 			invalid |= NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1395 		memcpy(&inode->i_ctime, &fattr->ctime, sizeof(inode->i_ctime));
1396 	}
1397 	memcpy(&inode->i_atime, &fattr->atime, sizeof(inode->i_atime));
1398 
1399 	if ((inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO) ||
1400 	    inode->i_uid != fattr->uid ||
1401 	    inode->i_gid != fattr->gid)
1402 		invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1403 
1404 	inode->i_mode = fattr->mode;
1405 	inode->i_nlink = fattr->nlink;
1406 	inode->i_uid = fattr->uid;
1407 	inode->i_gid = fattr->gid;
1408 
1409 	if (fattr->valid & (NFS_ATTR_FATTR_V3 | NFS_ATTR_FATTR_V4)) {
1410 		/*
1411 		 * report the blocks in 512byte units
1412 		 */
1413 		inode->i_blocks = nfs_calc_block_size(fattr->du.nfs3.used);
1414 		inode->i_blksize = inode->i_sb->s_blocksize;
1415  	} else {
1416  		inode->i_blocks = fattr->du.nfs2.blocks;
1417  		inode->i_blksize = fattr->du.nfs2.blocksize;
1418  	}
1419 
1420 	/* Update attrtimeo value if we're out of the unstable period */
1421 	if (invalid & NFS_INO_INVALID_ATTR) {
1422 		nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
1423 		nfsi->attrtimeo_timestamp = jiffies;
1424 	} else if (time_after(jiffies, nfsi->attrtimeo_timestamp+nfsi->attrtimeo)) {
1425 		if ((nfsi->attrtimeo <<= 1) > NFS_MAXATTRTIMEO(inode))
1426 			nfsi->attrtimeo = NFS_MAXATTRTIMEO(inode);
1427 		nfsi->attrtimeo_timestamp = jiffies;
1428 	}
1429 	/* Don't invalidate the data if we were to blame */
1430 	if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)
1431 				|| S_ISLNK(inode->i_mode)))
1432 		invalid &= ~NFS_INO_INVALID_DATA;
1433 	if (!nfs_have_delegation(inode, FMODE_READ))
1434 		nfsi->cache_validity |= invalid;
1435 
1436 	spin_unlock(&inode->i_lock);
1437 	return 0;
1438  out_changed:
1439 	/*
1440 	 * Big trouble! The inode has become a different object.
1441 	 */
1442 #ifdef NFS_PARANOIA
1443 	printk(KERN_DEBUG "%s: inode %ld mode changed, %07o to %07o\n",
1444 			__FUNCTION__, inode->i_ino, inode->i_mode, fattr->mode);
1445 #endif
1446 	/*
1447 	 * No need to worry about unhashing the dentry, as the
1448 	 * lookup validation will know that the inode is bad.
1449 	 * (But we fall through to invalidate the caches.)
1450 	 */
1451 	nfs_invalidate_inode(inode);
1452  out_err:
1453 	set_bit(NFS_INO_STALE, &NFS_FLAGS(inode));
1454 	return -ESTALE;
1455 }
1456 
1457 /*
1458  * File system information
1459  */
1460 
1461 static int nfs_set_super(struct super_block *s, void *data)
1462 {
1463 	s->s_fs_info = data;
1464 	return set_anon_super(s, data);
1465 }
1466 
1467 static int nfs_compare_super(struct super_block *sb, void *data)
1468 {
1469 	struct nfs_server *server = data;
1470 	struct nfs_server *old = NFS_SB(sb);
1471 
1472 	if (old->addr.sin_addr.s_addr != server->addr.sin_addr.s_addr)
1473 		return 0;
1474 	if (old->addr.sin_port != server->addr.sin_port)
1475 		return 0;
1476 	return !nfs_compare_fh(&old->fh, &server->fh);
1477 }
1478 
1479 static struct super_block *nfs_get_sb(struct file_system_type *fs_type,
1480 	int flags, const char *dev_name, void *raw_data)
1481 {
1482 	int error;
1483 	struct nfs_server *server = NULL;
1484 	struct super_block *s;
1485 	struct nfs_fh *root;
1486 	struct nfs_mount_data *data = raw_data;
1487 
1488 	s = ERR_PTR(-EINVAL);
1489 	if (data == NULL) {
1490 		dprintk("%s: missing data argument\n", __FUNCTION__);
1491 		goto out_err;
1492 	}
1493 	if (data->version <= 0 || data->version > NFS_MOUNT_VERSION) {
1494 		dprintk("%s: bad mount version\n", __FUNCTION__);
1495 		goto out_err;
1496 	}
1497 	switch (data->version) {
1498 		case 1:
1499 			data->namlen = 0;
1500 		case 2:
1501 			data->bsize  = 0;
1502 		case 3:
1503 			if (data->flags & NFS_MOUNT_VER3) {
1504 				dprintk("%s: mount structure version %d does not support NFSv3\n",
1505 						__FUNCTION__,
1506 						data->version);
1507 				goto out_err;
1508 			}
1509 			data->root.size = NFS2_FHSIZE;
1510 			memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1511 		case 4:
1512 			if (data->flags & NFS_MOUNT_SECFLAVOUR) {
1513 				dprintk("%s: mount structure version %d does not support strong security\n",
1514 						__FUNCTION__,
1515 						data->version);
1516 				goto out_err;
1517 			}
1518 		case 5:
1519 			memset(data->context, 0, sizeof(data->context));
1520 	}
1521 #ifndef CONFIG_NFS_V3
1522 	/* If NFSv3 is not compiled in, return -EPROTONOSUPPORT */
1523 	s = ERR_PTR(-EPROTONOSUPPORT);
1524 	if (data->flags & NFS_MOUNT_VER3) {
1525 		dprintk("%s: NFSv3 not compiled into kernel\n", __FUNCTION__);
1526 		goto out_err;
1527 	}
1528 #endif /* CONFIG_NFS_V3 */
1529 
1530 	s = ERR_PTR(-ENOMEM);
1531 	server = kmalloc(sizeof(struct nfs_server), GFP_KERNEL);
1532 	if (!server)
1533 		goto out_err;
1534 	memset(server, 0, sizeof(struct nfs_server));
1535 	/* Zero out the NFS state stuff */
1536 	init_nfsv4_state(server);
1537 	server->client = server->client_sys = server->client_acl = ERR_PTR(-EINVAL);
1538 
1539 	root = &server->fh;
1540 	if (data->flags & NFS_MOUNT_VER3)
1541 		root->size = data->root.size;
1542 	else
1543 		root->size = NFS2_FHSIZE;
1544 	s = ERR_PTR(-EINVAL);
1545 	if (root->size > sizeof(root->data)) {
1546 		dprintk("%s: invalid root filehandle\n", __FUNCTION__);
1547 		goto out_err;
1548 	}
1549 	memcpy(root->data, data->root.data, root->size);
1550 
1551 	/* We now require that the mount process passes the remote address */
1552 	memcpy(&server->addr, &data->addr, sizeof(server->addr));
1553 	if (server->addr.sin_addr.s_addr == INADDR_ANY) {
1554 		dprintk("%s: mount program didn't pass remote address!\n",
1555 				__FUNCTION__);
1556 		goto out_err;
1557 	}
1558 
1559 	/* Fire up rpciod if not yet running */
1560 	s = ERR_PTR(rpciod_up());
1561 	if (IS_ERR(s)) {
1562 		dprintk("%s: couldn't start rpciod! Error = %ld\n",
1563 				__FUNCTION__, PTR_ERR(s));
1564 		goto out_err;
1565 	}
1566 
1567 	s = sget(fs_type, nfs_compare_super, nfs_set_super, server);
1568 	if (IS_ERR(s) || s->s_root)
1569 		goto out_rpciod_down;
1570 
1571 	s->s_flags = flags;
1572 
1573 	error = nfs_fill_super(s, data, flags & MS_VERBOSE ? 1 : 0);
1574 	if (error) {
1575 		up_write(&s->s_umount);
1576 		deactivate_super(s);
1577 		return ERR_PTR(error);
1578 	}
1579 	s->s_flags |= MS_ACTIVE;
1580 	return s;
1581 out_rpciod_down:
1582 	rpciod_down();
1583 out_err:
1584 	kfree(server);
1585 	return s;
1586 }
1587 
1588 static void nfs_kill_super(struct super_block *s)
1589 {
1590 	struct nfs_server *server = NFS_SB(s);
1591 
1592 	kill_anon_super(s);
1593 
1594 	if (!IS_ERR(server->client))
1595 		rpc_shutdown_client(server->client);
1596 	if (!IS_ERR(server->client_sys))
1597 		rpc_shutdown_client(server->client_sys);
1598 	if (!IS_ERR(server->client_acl))
1599 		rpc_shutdown_client(server->client_acl);
1600 
1601 	if (!(server->flags & NFS_MOUNT_NONLM))
1602 		lockd_down();	/* release rpc.lockd */
1603 
1604 	rpciod_down();		/* release rpciod */
1605 
1606 	if (server->hostname != NULL)
1607 		kfree(server->hostname);
1608 	kfree(server);
1609 }
1610 
1611 static struct file_system_type nfs_fs_type = {
1612 	.owner		= THIS_MODULE,
1613 	.name		= "nfs",
1614 	.get_sb		= nfs_get_sb,
1615 	.kill_sb	= nfs_kill_super,
1616 	.fs_flags	= FS_ODD_RENAME|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
1617 };
1618 
1619 #ifdef CONFIG_NFS_V4
1620 
1621 static void nfs4_clear_inode(struct inode *);
1622 
1623 
1624 static struct super_operations nfs4_sops = {
1625 	.alloc_inode	= nfs_alloc_inode,
1626 	.destroy_inode	= nfs_destroy_inode,
1627 	.write_inode	= nfs_write_inode,
1628 	.delete_inode	= nfs_delete_inode,
1629 	.statfs		= nfs_statfs,
1630 	.clear_inode	= nfs4_clear_inode,
1631 	.umount_begin	= nfs_umount_begin,
1632 	.show_options	= nfs_show_options,
1633 };
1634 
1635 /*
1636  * Clean out any remaining NFSv4 state that might be left over due
1637  * to open() calls that passed nfs_atomic_lookup, but failed to call
1638  * nfs_open().
1639  */
1640 static void nfs4_clear_inode(struct inode *inode)
1641 {
1642 	struct nfs_inode *nfsi = NFS_I(inode);
1643 
1644 	/* If we are holding a delegation, return it! */
1645 	if (nfsi->delegation != NULL)
1646 		nfs_inode_return_delegation(inode);
1647 	/* First call standard NFS clear_inode() code */
1648 	nfs_clear_inode(inode);
1649 	/* Now clear out any remaining state */
1650 	while (!list_empty(&nfsi->open_states)) {
1651 		struct nfs4_state *state;
1652 
1653 		state = list_entry(nfsi->open_states.next,
1654 				struct nfs4_state,
1655 				inode_states);
1656 		dprintk("%s(%s/%Ld): found unclaimed NFSv4 state %p\n",
1657 				__FUNCTION__,
1658 				inode->i_sb->s_id,
1659 				(long long)NFS_FILEID(inode),
1660 				state);
1661 		BUG_ON(atomic_read(&state->count) != 1);
1662 		nfs4_close_state(state, state->state);
1663 	}
1664 }
1665 
1666 
1667 static int nfs4_fill_super(struct super_block *sb, struct nfs4_mount_data *data, int silent)
1668 {
1669 	struct nfs_server *server;
1670 	struct nfs4_client *clp = NULL;
1671 	struct rpc_xprt *xprt = NULL;
1672 	struct rpc_clnt *clnt = NULL;
1673 	struct rpc_timeout timeparms;
1674 	rpc_authflavor_t authflavour;
1675 	int proto, err = -EIO;
1676 
1677 	sb->s_blocksize_bits = 0;
1678 	sb->s_blocksize = 0;
1679 	server = NFS_SB(sb);
1680 	if (data->rsize != 0)
1681 		server->rsize = nfs_block_size(data->rsize, NULL);
1682 	if (data->wsize != 0)
1683 		server->wsize = nfs_block_size(data->wsize, NULL);
1684 	server->flags = data->flags & NFS_MOUNT_FLAGMASK;
1685 	server->caps = NFS_CAP_ATOMIC_OPEN;
1686 
1687 	server->acregmin = data->acregmin*HZ;
1688 	server->acregmax = data->acregmax*HZ;
1689 	server->acdirmin = data->acdirmin*HZ;
1690 	server->acdirmax = data->acdirmax*HZ;
1691 
1692 	server->rpc_ops = &nfs_v4_clientops;
1693 	/* Initialize timeout values */
1694 
1695 	timeparms.to_initval = data->timeo * HZ / 10;
1696 	timeparms.to_retries = data->retrans;
1697 	timeparms.to_exponential = 1;
1698 	if (!timeparms.to_retries)
1699 		timeparms.to_retries = 5;
1700 
1701 	proto = data->proto;
1702 	/* Which IP protocol do we use? */
1703 	switch (proto) {
1704 	case IPPROTO_TCP:
1705 		timeparms.to_maxval  = RPC_MAX_TCP_TIMEOUT;
1706 		if (!timeparms.to_initval)
1707 			timeparms.to_initval = 600 * HZ / 10;
1708 		break;
1709 	case IPPROTO_UDP:
1710 		timeparms.to_maxval  = RPC_MAX_UDP_TIMEOUT;
1711 		if (!timeparms.to_initval)
1712 			timeparms.to_initval = 11 * HZ / 10;
1713 		break;
1714 	default:
1715 		return -EINVAL;
1716 	}
1717 
1718 	clp = nfs4_get_client(&server->addr.sin_addr);
1719 	if (!clp) {
1720 		dprintk("%s: failed to create NFS4 client.\n", __FUNCTION__);
1721 		return -EIO;
1722 	}
1723 
1724 	/* Now create transport and client */
1725 	authflavour = RPC_AUTH_UNIX;
1726 	if (data->auth_flavourlen != 0) {
1727 		if (data->auth_flavourlen != 1) {
1728 			dprintk("%s: Invalid number of RPC auth flavours %d.\n",
1729 					__FUNCTION__, data->auth_flavourlen);
1730 			err = -EINVAL;
1731 			goto out_fail;
1732 		}
1733 		if (copy_from_user(&authflavour, data->auth_flavours, sizeof(authflavour))) {
1734 			err = -EFAULT;
1735 			goto out_fail;
1736 		}
1737 	}
1738 
1739 	down_write(&clp->cl_sem);
1740 	if (IS_ERR(clp->cl_rpcclient)) {
1741 		xprt = xprt_create_proto(proto, &server->addr, &timeparms);
1742 		if (IS_ERR(xprt)) {
1743 			up_write(&clp->cl_sem);
1744 			err = PTR_ERR(xprt);
1745 			dprintk("%s: cannot create RPC transport. Error = %d\n",
1746 					__FUNCTION__, err);
1747 			goto out_fail;
1748 		}
1749 		clnt = rpc_create_client(xprt, server->hostname, &nfs_program,
1750 				server->rpc_ops->version, authflavour);
1751 		if (IS_ERR(clnt)) {
1752 			up_write(&clp->cl_sem);
1753 			err = PTR_ERR(clnt);
1754 			dprintk("%s: cannot create RPC client. Error = %d\n",
1755 					__FUNCTION__, err);
1756 			goto out_fail;
1757 		}
1758 		clnt->cl_intr     = 1;
1759 		clnt->cl_softrtry = 1;
1760 		clnt->cl_chatty   = 1;
1761 		clp->cl_rpcclient = clnt;
1762 		clp->cl_cred = rpcauth_lookupcred(clnt->cl_auth, 0);
1763 		if (IS_ERR(clp->cl_cred)) {
1764 			up_write(&clp->cl_sem);
1765 			err = PTR_ERR(clp->cl_cred);
1766 			clp->cl_cred = NULL;
1767 			goto out_fail;
1768 		}
1769 		memcpy(clp->cl_ipaddr, server->ip_addr, sizeof(clp->cl_ipaddr));
1770 		nfs_idmap_new(clp);
1771 	}
1772 	if (list_empty(&clp->cl_superblocks)) {
1773 		err = nfs4_init_client(clp);
1774 		if (err != 0) {
1775 			up_write(&clp->cl_sem);
1776 			goto out_fail;
1777 		}
1778 	}
1779 	list_add_tail(&server->nfs4_siblings, &clp->cl_superblocks);
1780 	clnt = rpc_clone_client(clp->cl_rpcclient);
1781 	if (!IS_ERR(clnt))
1782 			server->nfs4_state = clp;
1783 	up_write(&clp->cl_sem);
1784 	clp = NULL;
1785 
1786 	if (IS_ERR(clnt)) {
1787 		err = PTR_ERR(clnt);
1788 		dprintk("%s: cannot create RPC client. Error = %d\n",
1789 				__FUNCTION__, err);
1790 		return err;
1791 	}
1792 
1793 	server->client    = clnt;
1794 
1795 	if (server->nfs4_state->cl_idmap == NULL) {
1796 		dprintk("%s: failed to create idmapper.\n", __FUNCTION__);
1797 		return -ENOMEM;
1798 	}
1799 
1800 	if (clnt->cl_auth->au_flavor != authflavour) {
1801 		struct rpc_auth *auth;
1802 
1803 		auth = rpcauth_create(authflavour, clnt);
1804 		if (IS_ERR(auth)) {
1805 			dprintk("%s: couldn't create credcache!\n", __FUNCTION__);
1806 			return PTR_ERR(auth);
1807 		}
1808 	}
1809 
1810 	sb->s_time_gran = 1;
1811 
1812 	sb->s_op = &nfs4_sops;
1813 	err = nfs_sb_init(sb, authflavour);
1814 	if (err == 0)
1815 		return 0;
1816 out_fail:
1817 	if (clp)
1818 		nfs4_put_client(clp);
1819 	return err;
1820 }
1821 
1822 static int nfs4_compare_super(struct super_block *sb, void *data)
1823 {
1824 	struct nfs_server *server = data;
1825 	struct nfs_server *old = NFS_SB(sb);
1826 
1827 	if (strcmp(server->hostname, old->hostname) != 0)
1828 		return 0;
1829 	if (strcmp(server->mnt_path, old->mnt_path) != 0)
1830 		return 0;
1831 	return 1;
1832 }
1833 
1834 static void *
1835 nfs_copy_user_string(char *dst, struct nfs_string *src, int maxlen)
1836 {
1837 	void *p = NULL;
1838 
1839 	if (!src->len)
1840 		return ERR_PTR(-EINVAL);
1841 	if (src->len < maxlen)
1842 		maxlen = src->len;
1843 	if (dst == NULL) {
1844 		p = dst = kmalloc(maxlen + 1, GFP_KERNEL);
1845 		if (p == NULL)
1846 			return ERR_PTR(-ENOMEM);
1847 	}
1848 	if (copy_from_user(dst, src->data, maxlen)) {
1849 		if (p != NULL)
1850 			kfree(p);
1851 		return ERR_PTR(-EFAULT);
1852 	}
1853 	dst[maxlen] = '\0';
1854 	return dst;
1855 }
1856 
1857 static struct super_block *nfs4_get_sb(struct file_system_type *fs_type,
1858 	int flags, const char *dev_name, void *raw_data)
1859 {
1860 	int error;
1861 	struct nfs_server *server;
1862 	struct super_block *s;
1863 	struct nfs4_mount_data *data = raw_data;
1864 	void *p;
1865 
1866 	if (data == NULL) {
1867 		dprintk("%s: missing data argument\n", __FUNCTION__);
1868 		return ERR_PTR(-EINVAL);
1869 	}
1870 	if (data->version <= 0 || data->version > NFS4_MOUNT_VERSION) {
1871 		dprintk("%s: bad mount version\n", __FUNCTION__);
1872 		return ERR_PTR(-EINVAL);
1873 	}
1874 
1875 	server = kmalloc(sizeof(struct nfs_server), GFP_KERNEL);
1876 	if (!server)
1877 		return ERR_PTR(-ENOMEM);
1878 	memset(server, 0, sizeof(struct nfs_server));
1879 	/* Zero out the NFS state stuff */
1880 	init_nfsv4_state(server);
1881 	server->client = server->client_sys = server->client_acl = ERR_PTR(-EINVAL);
1882 
1883 	p = nfs_copy_user_string(NULL, &data->hostname, 256);
1884 	if (IS_ERR(p))
1885 		goto out_err;
1886 	server->hostname = p;
1887 
1888 	p = nfs_copy_user_string(NULL, &data->mnt_path, 1024);
1889 	if (IS_ERR(p))
1890 		goto out_err;
1891 	server->mnt_path = p;
1892 
1893 	p = nfs_copy_user_string(server->ip_addr, &data->client_addr,
1894 			sizeof(server->ip_addr) - 1);
1895 	if (IS_ERR(p))
1896 		goto out_err;
1897 
1898 	/* We now require that the mount process passes the remote address */
1899 	if (data->host_addrlen != sizeof(server->addr)) {
1900 		s = ERR_PTR(-EINVAL);
1901 		goto out_free;
1902 	}
1903 	if (copy_from_user(&server->addr, data->host_addr, sizeof(server->addr))) {
1904 		s = ERR_PTR(-EFAULT);
1905 		goto out_free;
1906 	}
1907 	if (server->addr.sin_family != AF_INET ||
1908 	    server->addr.sin_addr.s_addr == INADDR_ANY) {
1909 		dprintk("%s: mount program didn't pass remote IP address!\n",
1910 				__FUNCTION__);
1911 		s = ERR_PTR(-EINVAL);
1912 		goto out_free;
1913 	}
1914 
1915 	/* Fire up rpciod if not yet running */
1916 	s = ERR_PTR(rpciod_up());
1917 	if (IS_ERR(s)) {
1918 		dprintk("%s: couldn't start rpciod! Error = %ld\n",
1919 				__FUNCTION__, PTR_ERR(s));
1920 		goto out_free;
1921 	}
1922 
1923 	s = sget(fs_type, nfs4_compare_super, nfs_set_super, server);
1924 
1925 	if (IS_ERR(s) || s->s_root)
1926 		goto out_free;
1927 
1928 	s->s_flags = flags;
1929 
1930 	error = nfs4_fill_super(s, data, flags & MS_VERBOSE ? 1 : 0);
1931 	if (error) {
1932 		up_write(&s->s_umount);
1933 		deactivate_super(s);
1934 		return ERR_PTR(error);
1935 	}
1936 	s->s_flags |= MS_ACTIVE;
1937 	return s;
1938 out_err:
1939 	s = (struct super_block *)p;
1940 out_free:
1941 	if (server->mnt_path)
1942 		kfree(server->mnt_path);
1943 	if (server->hostname)
1944 		kfree(server->hostname);
1945 	kfree(server);
1946 	return s;
1947 }
1948 
1949 static void nfs4_kill_super(struct super_block *sb)
1950 {
1951 	struct nfs_server *server = NFS_SB(sb);
1952 
1953 	nfs_return_all_delegations(sb);
1954 	kill_anon_super(sb);
1955 
1956 	nfs4_renewd_prepare_shutdown(server);
1957 
1958 	if (server->client != NULL && !IS_ERR(server->client))
1959 		rpc_shutdown_client(server->client);
1960 	rpciod_down();		/* release rpciod */
1961 
1962 	destroy_nfsv4_state(server);
1963 
1964 	if (server->hostname != NULL)
1965 		kfree(server->hostname);
1966 	kfree(server);
1967 }
1968 
1969 static struct file_system_type nfs4_fs_type = {
1970 	.owner		= THIS_MODULE,
1971 	.name		= "nfs4",
1972 	.get_sb		= nfs4_get_sb,
1973 	.kill_sb	= nfs4_kill_super,
1974 	.fs_flags	= FS_ODD_RENAME|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
1975 };
1976 
1977 #define nfs4_init_once(nfsi) \
1978 	do { \
1979 		INIT_LIST_HEAD(&(nfsi)->open_states); \
1980 		nfsi->delegation = NULL; \
1981 		nfsi->delegation_state = 0; \
1982 		init_rwsem(&nfsi->rwsem); \
1983 	} while(0)
1984 #define register_nfs4fs() register_filesystem(&nfs4_fs_type)
1985 #define unregister_nfs4fs() unregister_filesystem(&nfs4_fs_type)
1986 #else
1987 #define nfs4_init_once(nfsi) \
1988 	do { } while (0)
1989 #define register_nfs4fs() (0)
1990 #define unregister_nfs4fs()
1991 #endif
1992 
1993 extern int nfs_init_nfspagecache(void);
1994 extern void nfs_destroy_nfspagecache(void);
1995 extern int nfs_init_readpagecache(void);
1996 extern void nfs_destroy_readpagecache(void);
1997 extern int nfs_init_writepagecache(void);
1998 extern void nfs_destroy_writepagecache(void);
1999 #ifdef CONFIG_NFS_DIRECTIO
2000 extern int nfs_init_directcache(void);
2001 extern void nfs_destroy_directcache(void);
2002 #endif
2003 
2004 static kmem_cache_t * nfs_inode_cachep;
2005 
2006 static struct inode *nfs_alloc_inode(struct super_block *sb)
2007 {
2008 	struct nfs_inode *nfsi;
2009 	nfsi = (struct nfs_inode *)kmem_cache_alloc(nfs_inode_cachep, SLAB_KERNEL);
2010 	if (!nfsi)
2011 		return NULL;
2012 	nfsi->flags = 0UL;
2013 	nfsi->cache_validity = 0UL;
2014 #ifdef CONFIG_NFS_V3_ACL
2015 	nfsi->acl_access = ERR_PTR(-EAGAIN);
2016 	nfsi->acl_default = ERR_PTR(-EAGAIN);
2017 #endif
2018 #ifdef CONFIG_NFS_V4
2019 	nfsi->nfs4_acl = NULL;
2020 #endif /* CONFIG_NFS_V4 */
2021 	return &nfsi->vfs_inode;
2022 }
2023 
2024 static void nfs_destroy_inode(struct inode *inode)
2025 {
2026 	kmem_cache_free(nfs_inode_cachep, NFS_I(inode));
2027 }
2028 
2029 static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
2030 {
2031 	struct nfs_inode *nfsi = (struct nfs_inode *) foo;
2032 
2033 	if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
2034 	    SLAB_CTOR_CONSTRUCTOR) {
2035 		inode_init_once(&nfsi->vfs_inode);
2036 		spin_lock_init(&nfsi->req_lock);
2037 		INIT_LIST_HEAD(&nfsi->dirty);
2038 		INIT_LIST_HEAD(&nfsi->commit);
2039 		INIT_LIST_HEAD(&nfsi->open_files);
2040 		INIT_RADIX_TREE(&nfsi->nfs_page_tree, GFP_ATOMIC);
2041 		atomic_set(&nfsi->data_updates, 0);
2042 		nfsi->ndirty = 0;
2043 		nfsi->ncommit = 0;
2044 		nfsi->npages = 0;
2045 		nfs4_init_once(nfsi);
2046 	}
2047 }
2048 
2049 static int nfs_init_inodecache(void)
2050 {
2051 	nfs_inode_cachep = kmem_cache_create("nfs_inode_cache",
2052 					     sizeof(struct nfs_inode),
2053 					     0, SLAB_RECLAIM_ACCOUNT,
2054 					     init_once, NULL);
2055 	if (nfs_inode_cachep == NULL)
2056 		return -ENOMEM;
2057 
2058 	return 0;
2059 }
2060 
2061 static void nfs_destroy_inodecache(void)
2062 {
2063 	if (kmem_cache_destroy(nfs_inode_cachep))
2064 		printk(KERN_INFO "nfs_inode_cache: not all structures were freed\n");
2065 }
2066 
2067 /*
2068  * Initialize NFS
2069  */
2070 static int __init init_nfs_fs(void)
2071 {
2072 	int err;
2073 
2074 	err = nfs_init_nfspagecache();
2075 	if (err)
2076 		goto out4;
2077 
2078 	err = nfs_init_inodecache();
2079 	if (err)
2080 		goto out3;
2081 
2082 	err = nfs_init_readpagecache();
2083 	if (err)
2084 		goto out2;
2085 
2086 	err = nfs_init_writepagecache();
2087 	if (err)
2088 		goto out1;
2089 
2090 #ifdef CONFIG_NFS_DIRECTIO
2091 	err = nfs_init_directcache();
2092 	if (err)
2093 		goto out0;
2094 #endif
2095 
2096 #ifdef CONFIG_PROC_FS
2097 	rpc_proc_register(&nfs_rpcstat);
2098 #endif
2099         err = register_filesystem(&nfs_fs_type);
2100 	if (err)
2101 		goto out;
2102 	if ((err = register_nfs4fs()) != 0)
2103 		goto out;
2104 	return 0;
2105 out:
2106 #ifdef CONFIG_PROC_FS
2107 	rpc_proc_unregister("nfs");
2108 #endif
2109 	nfs_destroy_writepagecache();
2110 #ifdef CONFIG_NFS_DIRECTIO
2111 out0:
2112 	nfs_destroy_directcache();
2113 #endif
2114 out1:
2115 	nfs_destroy_readpagecache();
2116 out2:
2117 	nfs_destroy_inodecache();
2118 out3:
2119 	nfs_destroy_nfspagecache();
2120 out4:
2121 	return err;
2122 }
2123 
2124 static void __exit exit_nfs_fs(void)
2125 {
2126 #ifdef CONFIG_NFS_DIRECTIO
2127 	nfs_destroy_directcache();
2128 #endif
2129 	nfs_destroy_writepagecache();
2130 	nfs_destroy_readpagecache();
2131 	nfs_destroy_inodecache();
2132 	nfs_destroy_nfspagecache();
2133 #ifdef CONFIG_PROC_FS
2134 	rpc_proc_unregister("nfs");
2135 #endif
2136 	unregister_filesystem(&nfs_fs_type);
2137 	unregister_nfs4fs();
2138 }
2139 
2140 /* Not quite true; I just maintain it */
2141 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
2142 MODULE_LICENSE("GPL");
2143 
2144 module_init(init_nfs_fs)
2145 module_exit(exit_nfs_fs)
2146