xref: /linux/fs/nfs/inode.c (revision d67b569f5f620c0fb95d5212642746b7ba9d29e4)
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 	NFS_ATTRTIMEO(inode) = NFS_MINATTRTIMEO(inode);
619 	NFS_ATTRTIMEO_UPDATE(inode) = jiffies;
620 
621 	memset(NFS_COOKIEVERF(inode), 0, sizeof(NFS_COOKIEVERF(inode)));
622 	if (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))
623 		nfsi->flags |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL|NFS_INO_REVAL_PAGECACHE;
624 	else
625 		nfsi->flags |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL|NFS_INO_REVAL_PAGECACHE;
626 }
627 
628 static void nfs_zap_acl_cache(struct inode *inode)
629 {
630 	void (*clear_acl_cache)(struct inode *);
631 
632 	clear_acl_cache = NFS_PROTO(inode)->clear_acl_cache;
633 	if (clear_acl_cache != NULL)
634 		clear_acl_cache(inode);
635 	NFS_I(inode)->flags &= ~NFS_INO_INVALID_ACL;
636 }
637 
638 /*
639  * Invalidate, but do not unhash, the inode
640  */
641 static void
642 nfs_invalidate_inode(struct inode *inode)
643 {
644 	umode_t save_mode = inode->i_mode;
645 
646 	make_bad_inode(inode);
647 	inode->i_mode = save_mode;
648 	nfs_zap_caches(inode);
649 }
650 
651 struct nfs_find_desc {
652 	struct nfs_fh		*fh;
653 	struct nfs_fattr	*fattr;
654 };
655 
656 /*
657  * In NFSv3 we can have 64bit inode numbers. In order to support
658  * this, and re-exported directories (also seen in NFSv2)
659  * we are forced to allow 2 different inodes to have the same
660  * i_ino.
661  */
662 static int
663 nfs_find_actor(struct inode *inode, void *opaque)
664 {
665 	struct nfs_find_desc	*desc = (struct nfs_find_desc *)opaque;
666 	struct nfs_fh		*fh = desc->fh;
667 	struct nfs_fattr	*fattr = desc->fattr;
668 
669 	if (NFS_FILEID(inode) != fattr->fileid)
670 		return 0;
671 	if (nfs_compare_fh(NFS_FH(inode), fh))
672 		return 0;
673 	if (is_bad_inode(inode) || NFS_STALE(inode))
674 		return 0;
675 	return 1;
676 }
677 
678 static int
679 nfs_init_locked(struct inode *inode, void *opaque)
680 {
681 	struct nfs_find_desc	*desc = (struct nfs_find_desc *)opaque;
682 	struct nfs_fattr	*fattr = desc->fattr;
683 
684 	NFS_FILEID(inode) = fattr->fileid;
685 	nfs_copy_fh(NFS_FH(inode), desc->fh);
686 	return 0;
687 }
688 
689 /* Don't use READDIRPLUS on directories that we believe are too large */
690 #define NFS_LIMIT_READDIRPLUS (8*PAGE_SIZE)
691 
692 /*
693  * This is our front-end to iget that looks up inodes by file handle
694  * instead of inode number.
695  */
696 struct inode *
697 nfs_fhget(struct super_block *sb, struct nfs_fh *fh, struct nfs_fattr *fattr)
698 {
699 	struct nfs_find_desc desc = {
700 		.fh	= fh,
701 		.fattr	= fattr
702 	};
703 	struct inode *inode = NULL;
704 	unsigned long hash;
705 
706 	if ((fattr->valid & NFS_ATTR_FATTR) == 0)
707 		goto out_no_inode;
708 
709 	if (!fattr->nlink) {
710 		printk("NFS: Buggy server - nlink == 0!\n");
711 		goto out_no_inode;
712 	}
713 
714 	hash = nfs_fattr_to_ino_t(fattr);
715 
716 	if (!(inode = iget5_locked(sb, hash, nfs_find_actor, nfs_init_locked, &desc)))
717 		goto out_no_inode;
718 
719 	if (inode->i_state & I_NEW) {
720 		struct nfs_inode *nfsi = NFS_I(inode);
721 
722 		/* We set i_ino for the few things that still rely on it,
723 		 * such as stat(2) */
724 		inode->i_ino = hash;
725 
726 		/* We can't support update_atime(), since the server will reset it */
727 		inode->i_flags |= S_NOATIME|S_NOCMTIME;
728 		inode->i_mode = fattr->mode;
729 		/* Why so? Because we want revalidate for devices/FIFOs, and
730 		 * that's precisely what we have in nfs_file_inode_operations.
731 		 */
732 		inode->i_op = NFS_SB(sb)->rpc_ops->file_inode_ops;
733 		if (S_ISREG(inode->i_mode)) {
734 			inode->i_fop = &nfs_file_operations;
735 			inode->i_data.a_ops = &nfs_file_aops;
736 			inode->i_data.backing_dev_info = &NFS_SB(sb)->backing_dev_info;
737 		} else if (S_ISDIR(inode->i_mode)) {
738 			inode->i_op = NFS_SB(sb)->rpc_ops->dir_inode_ops;
739 			inode->i_fop = &nfs_dir_operations;
740 			if (nfs_server_capable(inode, NFS_CAP_READDIRPLUS)
741 			    && fattr->size <= NFS_LIMIT_READDIRPLUS)
742 				NFS_FLAGS(inode) |= NFS_INO_ADVISE_RDPLUS;
743 		} else if (S_ISLNK(inode->i_mode))
744 			inode->i_op = &nfs_symlink_inode_operations;
745 		else
746 			init_special_inode(inode, inode->i_mode, fattr->rdev);
747 
748 		nfsi->read_cache_jiffies = fattr->timestamp;
749 		inode->i_atime = fattr->atime;
750 		inode->i_mtime = fattr->mtime;
751 		inode->i_ctime = fattr->ctime;
752 		if (fattr->valid & NFS_ATTR_FATTR_V4)
753 			nfsi->change_attr = fattr->change_attr;
754 		inode->i_size = nfs_size_to_loff_t(fattr->size);
755 		inode->i_nlink = fattr->nlink;
756 		inode->i_uid = fattr->uid;
757 		inode->i_gid = fattr->gid;
758 		if (fattr->valid & (NFS_ATTR_FATTR_V3 | NFS_ATTR_FATTR_V4)) {
759 			/*
760 			 * report the blocks in 512byte units
761 			 */
762 			inode->i_blocks = nfs_calc_block_size(fattr->du.nfs3.used);
763 			inode->i_blksize = inode->i_sb->s_blocksize;
764 		} else {
765 			inode->i_blocks = fattr->du.nfs2.blocks;
766 			inode->i_blksize = fattr->du.nfs2.blocksize;
767 		}
768 		nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
769 		nfsi->attrtimeo_timestamp = jiffies;
770 		memset(nfsi->cookieverf, 0, sizeof(nfsi->cookieverf));
771 		nfsi->cache_access.cred = NULL;
772 
773 		unlock_new_inode(inode);
774 	} else
775 		nfs_refresh_inode(inode, fattr);
776 	dprintk("NFS: nfs_fhget(%s/%Ld ct=%d)\n",
777 		inode->i_sb->s_id,
778 		(long long)NFS_FILEID(inode),
779 		atomic_read(&inode->i_count));
780 
781 out:
782 	return inode;
783 
784 out_no_inode:
785 	printk("nfs_fhget: iget failed\n");
786 	goto out;
787 }
788 
789 #define NFS_VALID_ATTRS (ATTR_MODE|ATTR_UID|ATTR_GID|ATTR_SIZE|ATTR_ATIME|ATTR_ATIME_SET|ATTR_MTIME|ATTR_MTIME_SET)
790 
791 int
792 nfs_setattr(struct dentry *dentry, struct iattr *attr)
793 {
794 	struct inode *inode = dentry->d_inode;
795 	struct nfs_fattr fattr;
796 	int error;
797 
798 	if (attr->ia_valid & ATTR_SIZE) {
799 		if (!S_ISREG(inode->i_mode) || attr->ia_size == i_size_read(inode))
800 			attr->ia_valid &= ~ATTR_SIZE;
801 	}
802 
803 	/* Optimization: if the end result is no change, don't RPC */
804 	attr->ia_valid &= NFS_VALID_ATTRS;
805 	if (attr->ia_valid == 0)
806 		return 0;
807 
808 	lock_kernel();
809 	nfs_begin_data_update(inode);
810 	/* Write all dirty data if we're changing file permissions or size */
811 	if ((attr->ia_valid & (ATTR_MODE|ATTR_UID|ATTR_GID|ATTR_SIZE)) != 0) {
812 		if (filemap_fdatawrite(inode->i_mapping) == 0)
813 			filemap_fdatawait(inode->i_mapping);
814 		nfs_wb_all(inode);
815 	}
816 	error = NFS_PROTO(inode)->setattr(dentry, &fattr, attr);
817 	if (error == 0) {
818 		nfs_refresh_inode(inode, &fattr);
819 		if ((attr->ia_valid & ATTR_MODE) != 0) {
820 			int mode;
821 			mode = inode->i_mode & ~S_IALLUGO;
822 			mode |= attr->ia_mode & S_IALLUGO;
823 			inode->i_mode = mode;
824 		}
825 		if ((attr->ia_valid & ATTR_UID) != 0)
826 			inode->i_uid = attr->ia_uid;
827 		if ((attr->ia_valid & ATTR_GID) != 0)
828 			inode->i_gid = attr->ia_gid;
829 		if ((attr->ia_valid & ATTR_SIZE) != 0) {
830 			inode->i_size = attr->ia_size;
831 			vmtruncate(inode, attr->ia_size);
832 		}
833 	}
834 	if ((attr->ia_valid & (ATTR_MODE|ATTR_UID|ATTR_GID)) != 0)
835 		NFS_FLAGS(inode) |= NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
836 	nfs_end_data_update(inode);
837 	unlock_kernel();
838 	return error;
839 }
840 
841 /*
842  * Wait for the inode to get unlocked.
843  * (Used for NFS_INO_LOCKED and NFS_INO_REVALIDATING).
844  */
845 static int
846 nfs_wait_on_inode(struct inode *inode, int flag)
847 {
848 	struct rpc_clnt	*clnt = NFS_CLIENT(inode);
849 	struct nfs_inode *nfsi = NFS_I(inode);
850 
851 	int error;
852 	if (!(NFS_FLAGS(inode) & flag))
853 		return 0;
854 	atomic_inc(&inode->i_count);
855 	error = nfs_wait_event(clnt, nfsi->nfs_i_wait,
856 				!(NFS_FLAGS(inode) & flag));
857 	iput(inode);
858 	return error;
859 }
860 
861 int nfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
862 {
863 	struct inode *inode = dentry->d_inode;
864 	struct nfs_inode *nfsi = NFS_I(inode);
865 	int need_atime = nfsi->flags & NFS_INO_INVALID_ATIME;
866 	int err;
867 
868 	if (__IS_FLG(inode, MS_NOATIME))
869 		need_atime = 0;
870 	else if (__IS_FLG(inode, MS_NODIRATIME) && S_ISDIR(inode->i_mode))
871 		need_atime = 0;
872 	/* We may force a getattr if the user cares about atime */
873 	if (need_atime)
874 		err = __nfs_revalidate_inode(NFS_SERVER(inode), inode);
875 	else
876 		err = nfs_revalidate_inode(NFS_SERVER(inode), inode);
877 	if (!err)
878 		generic_fillattr(inode, stat);
879 	return err;
880 }
881 
882 struct nfs_open_context *alloc_nfs_open_context(struct dentry *dentry, struct rpc_cred *cred)
883 {
884 	struct nfs_open_context *ctx;
885 
886 	ctx = (struct nfs_open_context *)kmalloc(sizeof(*ctx), GFP_KERNEL);
887 	if (ctx != NULL) {
888 		atomic_set(&ctx->count, 1);
889 		ctx->dentry = dget(dentry);
890 		ctx->cred = get_rpccred(cred);
891 		ctx->state = NULL;
892 		ctx->lockowner = current->files;
893 		ctx->error = 0;
894 		ctx->dir_cookie = 0;
895 	}
896 	return ctx;
897 }
898 
899 struct nfs_open_context *get_nfs_open_context(struct nfs_open_context *ctx)
900 {
901 	if (ctx != NULL)
902 		atomic_inc(&ctx->count);
903 	return ctx;
904 }
905 
906 void put_nfs_open_context(struct nfs_open_context *ctx)
907 {
908 	if (atomic_dec_and_test(&ctx->count)) {
909 		if (!list_empty(&ctx->list)) {
910 			struct inode *inode = ctx->dentry->d_inode;
911 			spin_lock(&inode->i_lock);
912 			list_del(&ctx->list);
913 			spin_unlock(&inode->i_lock);
914 		}
915 		if (ctx->state != NULL)
916 			nfs4_close_state(ctx->state, ctx->mode);
917 		if (ctx->cred != NULL)
918 			put_rpccred(ctx->cred);
919 		dput(ctx->dentry);
920 		kfree(ctx);
921 	}
922 }
923 
924 /*
925  * Ensure that mmap has a recent RPC credential for use when writing out
926  * shared pages
927  */
928 void nfs_file_set_open_context(struct file *filp, struct nfs_open_context *ctx)
929 {
930 	struct inode *inode = filp->f_dentry->d_inode;
931 	struct nfs_inode *nfsi = NFS_I(inode);
932 
933 	filp->private_data = get_nfs_open_context(ctx);
934 	spin_lock(&inode->i_lock);
935 	list_add(&ctx->list, &nfsi->open_files);
936 	spin_unlock(&inode->i_lock);
937 }
938 
939 struct nfs_open_context *nfs_find_open_context(struct inode *inode, int mode)
940 {
941 	struct nfs_inode *nfsi = NFS_I(inode);
942 	struct nfs_open_context *pos, *ctx = NULL;
943 
944 	spin_lock(&inode->i_lock);
945 	list_for_each_entry(pos, &nfsi->open_files, list) {
946 		if ((pos->mode & mode) == mode) {
947 			ctx = get_nfs_open_context(pos);
948 			break;
949 		}
950 	}
951 	spin_unlock(&inode->i_lock);
952 	return ctx;
953 }
954 
955 void nfs_file_clear_open_context(struct file *filp)
956 {
957 	struct inode *inode = filp->f_dentry->d_inode;
958 	struct nfs_open_context *ctx = (struct nfs_open_context *)filp->private_data;
959 
960 	if (ctx) {
961 		filp->private_data = NULL;
962 		spin_lock(&inode->i_lock);
963 		list_move_tail(&ctx->list, &NFS_I(inode)->open_files);
964 		spin_unlock(&inode->i_lock);
965 		put_nfs_open_context(ctx);
966 	}
967 }
968 
969 /*
970  * These allocate and release file read/write context information.
971  */
972 int nfs_open(struct inode *inode, struct file *filp)
973 {
974 	struct nfs_open_context *ctx;
975 	struct rpc_cred *cred;
976 
977 	cred = rpcauth_lookupcred(NFS_CLIENT(inode)->cl_auth, 0);
978 	if (IS_ERR(cred))
979 		return PTR_ERR(cred);
980 	ctx = alloc_nfs_open_context(filp->f_dentry, cred);
981 	put_rpccred(cred);
982 	if (ctx == NULL)
983 		return -ENOMEM;
984 	ctx->mode = filp->f_mode;
985 	nfs_file_set_open_context(filp, ctx);
986 	put_nfs_open_context(ctx);
987 	if ((filp->f_mode & FMODE_WRITE) != 0)
988 		nfs_begin_data_update(inode);
989 	return 0;
990 }
991 
992 int nfs_release(struct inode *inode, struct file *filp)
993 {
994 	if ((filp->f_mode & FMODE_WRITE) != 0)
995 		nfs_end_data_update(inode);
996 	nfs_file_clear_open_context(filp);
997 	return 0;
998 }
999 
1000 /*
1001  * This function is called whenever some part of NFS notices that
1002  * the cached attributes have to be refreshed.
1003  */
1004 int
1005 __nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
1006 {
1007 	int		 status = -ESTALE;
1008 	struct nfs_fattr fattr;
1009 	struct nfs_inode *nfsi = NFS_I(inode);
1010 	unsigned long verifier;
1011 	unsigned int flags;
1012 
1013 	dfprintk(PAGECACHE, "NFS: revalidating (%s/%Ld)\n",
1014 		inode->i_sb->s_id, (long long)NFS_FILEID(inode));
1015 
1016 	lock_kernel();
1017 	if (!inode || is_bad_inode(inode))
1018  		goto out_nowait;
1019 	if (NFS_STALE(inode))
1020  		goto out_nowait;
1021 
1022 	while (NFS_REVALIDATING(inode)) {
1023 		status = nfs_wait_on_inode(inode, NFS_INO_REVALIDATING);
1024 		if (status < 0)
1025 			goto out_nowait;
1026 		if (NFS_ATTRTIMEO(inode) == 0)
1027 			continue;
1028 		if (NFS_FLAGS(inode) & (NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA|NFS_INO_INVALID_ATIME))
1029 			continue;
1030 		status = NFS_STALE(inode) ? -ESTALE : 0;
1031 		goto out_nowait;
1032 	}
1033 	NFS_FLAGS(inode) |= NFS_INO_REVALIDATING;
1034 
1035 	/* Protect against RPC races by saving the change attribute */
1036 	verifier = nfs_save_change_attribute(inode);
1037 	status = NFS_PROTO(inode)->getattr(server, NFS_FH(inode), &fattr);
1038 	if (status != 0) {
1039 		dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Ld) getattr failed, error=%d\n",
1040 			 inode->i_sb->s_id,
1041 			 (long long)NFS_FILEID(inode), status);
1042 		if (status == -ESTALE) {
1043 			nfs_zap_caches(inode);
1044 			if (!S_ISDIR(inode->i_mode))
1045 				NFS_FLAGS(inode) |= NFS_INO_STALE;
1046 		}
1047 		goto out;
1048 	}
1049 
1050 	status = nfs_update_inode(inode, &fattr, verifier);
1051 	if (status) {
1052 		dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Ld) refresh failed, error=%d\n",
1053 			 inode->i_sb->s_id,
1054 			 (long long)NFS_FILEID(inode), status);
1055 		goto out;
1056 	}
1057 	flags = nfsi->flags;
1058 	nfsi->flags &= ~NFS_INO_REVAL_PAGECACHE;
1059 	/*
1060 	 * We may need to keep the attributes marked as invalid if
1061 	 * we raced with nfs_end_attr_update().
1062 	 */
1063 	if (verifier == nfsi->cache_change_attribute)
1064 		nfsi->flags &= ~(NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ATIME);
1065 	/* Do the page cache invalidation */
1066 	nfs_revalidate_mapping(inode, inode->i_mapping);
1067 	if (flags & NFS_INO_INVALID_ACL)
1068 		nfs_zap_acl_cache(inode);
1069 	dfprintk(PAGECACHE, "NFS: (%s/%Ld) revalidation complete\n",
1070 		inode->i_sb->s_id,
1071 		(long long)NFS_FILEID(inode));
1072 
1073 out:
1074 	NFS_FLAGS(inode) &= ~NFS_INO_REVALIDATING;
1075 	wake_up(&nfsi->nfs_i_wait);
1076  out_nowait:
1077 	unlock_kernel();
1078 	return status;
1079 }
1080 
1081 int nfs_attribute_timeout(struct inode *inode)
1082 {
1083 	struct nfs_inode *nfsi = NFS_I(inode);
1084 
1085 	if (nfs_have_delegation(inode, FMODE_READ))
1086 		return 0;
1087 	return time_after(jiffies, nfsi->read_cache_jiffies+nfsi->attrtimeo);
1088 }
1089 
1090 /**
1091  * nfs_revalidate_inode - Revalidate the inode attributes
1092  * @server - pointer to nfs_server struct
1093  * @inode - pointer to inode struct
1094  *
1095  * Updates inode attribute information by retrieving the data from the server.
1096  */
1097 int nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
1098 {
1099 	if (!(NFS_FLAGS(inode) & (NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA))
1100 			&& !nfs_attribute_timeout(inode))
1101 		return NFS_STALE(inode) ? -ESTALE : 0;
1102 	return __nfs_revalidate_inode(server, inode);
1103 }
1104 
1105 /**
1106  * nfs_revalidate_mapping - Revalidate the pagecache
1107  * @inode - pointer to host inode
1108  * @mapping - pointer to mapping
1109  */
1110 void nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping)
1111 {
1112 	struct nfs_inode *nfsi = NFS_I(inode);
1113 
1114 	if (nfsi->flags & NFS_INO_INVALID_DATA) {
1115 		if (S_ISREG(inode->i_mode)) {
1116 			if (filemap_fdatawrite(mapping) == 0)
1117 				filemap_fdatawait(mapping);
1118 			nfs_wb_all(inode);
1119 		}
1120 		invalidate_inode_pages2(mapping);
1121 		nfsi->flags &= ~NFS_INO_INVALID_DATA;
1122 		if (S_ISDIR(inode->i_mode)) {
1123 			memset(nfsi->cookieverf, 0, sizeof(nfsi->cookieverf));
1124 			/* This ensures we revalidate child dentries */
1125 			nfsi->cache_change_attribute++;
1126 		}
1127 		dfprintk(PAGECACHE, "NFS: (%s/%Ld) data cache invalidated\n",
1128 				inode->i_sb->s_id,
1129 				(long long)NFS_FILEID(inode));
1130 	}
1131 }
1132 
1133 /**
1134  * nfs_begin_data_update
1135  * @inode - pointer to inode
1136  * Declare that a set of operations will update file data on the server
1137  */
1138 void nfs_begin_data_update(struct inode *inode)
1139 {
1140 	atomic_inc(&NFS_I(inode)->data_updates);
1141 }
1142 
1143 /**
1144  * nfs_end_data_update
1145  * @inode - pointer to inode
1146  * Declare end of the operations that will update file data
1147  * This will mark the inode as immediately needing revalidation
1148  * of its attribute cache.
1149  */
1150 void nfs_end_data_update(struct inode *inode)
1151 {
1152 	struct nfs_inode *nfsi = NFS_I(inode);
1153 
1154 	if (!nfs_have_delegation(inode, FMODE_READ)) {
1155 		/* Mark the attribute cache for revalidation */
1156 		nfsi->flags |= NFS_INO_INVALID_ATTR;
1157 		/* Directories and symlinks: invalidate page cache too */
1158 		if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
1159 			nfsi->flags |= NFS_INO_INVALID_DATA;
1160 	}
1161 	nfsi->cache_change_attribute ++;
1162 	atomic_dec(&nfsi->data_updates);
1163 }
1164 
1165 /**
1166  * nfs_refresh_inode - verify consistency of the inode attribute cache
1167  * @inode - pointer to inode
1168  * @fattr - updated attributes
1169  *
1170  * Verifies the attribute cache. If we have just changed the attributes,
1171  * so that fattr carries weak cache consistency data, then it may
1172  * also update the ctime/mtime/change_attribute.
1173  */
1174 int nfs_refresh_inode(struct inode *inode, struct nfs_fattr *fattr)
1175 {
1176 	struct nfs_inode *nfsi = NFS_I(inode);
1177 	loff_t cur_size, new_isize;
1178 	int data_unstable;
1179 
1180 	/* Do we hold a delegation? */
1181 	if (nfs_have_delegation(inode, FMODE_READ))
1182 		return 0;
1183 
1184 	/* Are we in the process of updating data on the server? */
1185 	data_unstable = nfs_caches_unstable(inode);
1186 
1187 	if (fattr->valid & NFS_ATTR_FATTR_V4) {
1188 		if ((fattr->valid & NFS_ATTR_PRE_CHANGE) != 0
1189 				&& nfsi->change_attr == fattr->pre_change_attr)
1190 			nfsi->change_attr = fattr->change_attr;
1191 		if (nfsi->change_attr != fattr->change_attr) {
1192 			nfsi->flags |= NFS_INO_INVALID_ATTR;
1193 			if (!data_unstable)
1194 				nfsi->flags |= NFS_INO_REVAL_PAGECACHE;
1195 		}
1196 	}
1197 
1198 	if ((fattr->valid & NFS_ATTR_FATTR) == 0)
1199 		return 0;
1200 
1201 	/* Has the inode gone and changed behind our back? */
1202 	if (nfsi->fileid != fattr->fileid
1203 			|| (inode->i_mode & S_IFMT) != (fattr->mode & S_IFMT))
1204 		return -EIO;
1205 
1206 	cur_size = i_size_read(inode);
1207  	new_isize = nfs_size_to_loff_t(fattr->size);
1208 
1209 	/* If we have atomic WCC data, we may update some attributes */
1210 	if ((fattr->valid & NFS_ATTR_WCC) != 0) {
1211 		if (timespec_equal(&inode->i_ctime, &fattr->pre_ctime))
1212 			memcpy(&inode->i_ctime, &fattr->ctime, sizeof(inode->i_ctime));
1213 		if (timespec_equal(&inode->i_mtime, &fattr->pre_mtime))
1214 			memcpy(&inode->i_mtime, &fattr->mtime, sizeof(inode->i_mtime));
1215 	}
1216 
1217 	/* Verify a few of the more important attributes */
1218 	if (!timespec_equal(&inode->i_mtime, &fattr->mtime)) {
1219 		nfsi->flags |= NFS_INO_INVALID_ATTR;
1220 		if (!data_unstable)
1221 			nfsi->flags |= NFS_INO_REVAL_PAGECACHE;
1222 	}
1223 	if (cur_size != new_isize) {
1224 		nfsi->flags |= NFS_INO_INVALID_ATTR;
1225 		if (nfsi->npages == 0)
1226 			nfsi->flags |= NFS_INO_REVAL_PAGECACHE;
1227 	}
1228 
1229 	/* Have any file permissions changed? */
1230 	if ((inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO)
1231 			|| inode->i_uid != fattr->uid
1232 			|| inode->i_gid != fattr->gid)
1233 		nfsi->flags |= NFS_INO_INVALID_ATTR | NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL;
1234 
1235 	/* Has the link count changed? */
1236 	if (inode->i_nlink != fattr->nlink)
1237 		nfsi->flags |= NFS_INO_INVALID_ATTR;
1238 
1239 	if (!timespec_equal(&inode->i_atime, &fattr->atime))
1240 		nfsi->flags |= NFS_INO_INVALID_ATIME;
1241 
1242 	nfsi->read_cache_jiffies = fattr->timestamp;
1243 	return 0;
1244 }
1245 
1246 /*
1247  * Many nfs protocol calls return the new file attributes after
1248  * an operation.  Here we update the inode to reflect the state
1249  * of the server's inode.
1250  *
1251  * This is a bit tricky because we have to make sure all dirty pages
1252  * have been sent off to the server before calling invalidate_inode_pages.
1253  * To make sure no other process adds more write requests while we try
1254  * our best to flush them, we make them sleep during the attribute refresh.
1255  *
1256  * A very similar scenario holds for the dir cache.
1257  */
1258 static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr, unsigned long verifier)
1259 {
1260 	struct nfs_inode *nfsi = NFS_I(inode);
1261 	loff_t cur_isize, new_isize;
1262 	unsigned int	invalid = 0;
1263 	int data_unstable;
1264 
1265 	dfprintk(VFS, "NFS: %s(%s/%ld ct=%d info=0x%x)\n",
1266 			__FUNCTION__, inode->i_sb->s_id, inode->i_ino,
1267 			atomic_read(&inode->i_count), fattr->valid);
1268 
1269 	if ((fattr->valid & NFS_ATTR_FATTR) == 0)
1270 		return 0;
1271 
1272 	if (nfsi->fileid != fattr->fileid) {
1273 		printk(KERN_ERR "%s: inode number mismatch\n"
1274 		       "expected (%s/0x%Lx), got (%s/0x%Lx)\n",
1275 		       __FUNCTION__,
1276 		       inode->i_sb->s_id, (long long)nfsi->fileid,
1277 		       inode->i_sb->s_id, (long long)fattr->fileid);
1278 		goto out_err;
1279 	}
1280 
1281 	/*
1282 	 * Make sure the inode's type hasn't changed.
1283 	 */
1284 	if ((inode->i_mode & S_IFMT) != (fattr->mode & S_IFMT))
1285 		goto out_changed;
1286 
1287 	/*
1288 	 * Update the read time so we don't revalidate too often.
1289 	 */
1290 	nfsi->read_cache_jiffies = fattr->timestamp;
1291 
1292 	/* Are we racing with known updates of the metadata on the server? */
1293 	data_unstable = ! nfs_verify_change_attribute(inode, verifier);
1294 
1295 	/* Check if our cached file size is stale */
1296  	new_isize = nfs_size_to_loff_t(fattr->size);
1297 	cur_isize = i_size_read(inode);
1298 	if (new_isize != cur_isize) {
1299 		/* Do we perhaps have any outstanding writes? */
1300 		if (nfsi->npages == 0) {
1301 			/* No, but did we race with nfs_end_data_update()? */
1302 			if (verifier  ==  nfsi->cache_change_attribute) {
1303 				inode->i_size = new_isize;
1304 				invalid |= NFS_INO_INVALID_DATA;
1305 			}
1306 			invalid |= NFS_INO_INVALID_ATTR;
1307 		} else if (new_isize > cur_isize) {
1308 			inode->i_size = new_isize;
1309 			invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA;
1310 		}
1311 		dprintk("NFS: isize change on server for file %s/%ld\n",
1312 				inode->i_sb->s_id, inode->i_ino);
1313 	}
1314 
1315 	/* Check if the mtime agrees */
1316 	if (!timespec_equal(&inode->i_mtime, &fattr->mtime)) {
1317 		memcpy(&inode->i_mtime, &fattr->mtime, sizeof(inode->i_mtime));
1318 		dprintk("NFS: mtime change on server for file %s/%ld\n",
1319 				inode->i_sb->s_id, inode->i_ino);
1320 		if (!data_unstable)
1321 			invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA;
1322 	}
1323 
1324 	if ((fattr->valid & NFS_ATTR_FATTR_V4)
1325 	    && nfsi->change_attr != fattr->change_attr) {
1326 		dprintk("NFS: change_attr change on server for file %s/%ld\n",
1327 		       inode->i_sb->s_id, inode->i_ino);
1328 		nfsi->change_attr = fattr->change_attr;
1329 		if (!data_unstable)
1330 			invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1331 	}
1332 
1333 	/* If ctime has changed we should definitely clear access+acl caches */
1334 	if (!timespec_equal(&inode->i_ctime, &fattr->ctime)) {
1335 		if (!data_unstable)
1336 			invalid |= NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1337 		memcpy(&inode->i_ctime, &fattr->ctime, sizeof(inode->i_ctime));
1338 	}
1339 	memcpy(&inode->i_atime, &fattr->atime, sizeof(inode->i_atime));
1340 
1341 	if ((inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO) ||
1342 	    inode->i_uid != fattr->uid ||
1343 	    inode->i_gid != fattr->gid)
1344 		invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
1345 
1346 	inode->i_mode = fattr->mode;
1347 	inode->i_nlink = fattr->nlink;
1348 	inode->i_uid = fattr->uid;
1349 	inode->i_gid = fattr->gid;
1350 
1351 	if (fattr->valid & (NFS_ATTR_FATTR_V3 | NFS_ATTR_FATTR_V4)) {
1352 		/*
1353 		 * report the blocks in 512byte units
1354 		 */
1355 		inode->i_blocks = nfs_calc_block_size(fattr->du.nfs3.used);
1356 		inode->i_blksize = inode->i_sb->s_blocksize;
1357  	} else {
1358  		inode->i_blocks = fattr->du.nfs2.blocks;
1359  		inode->i_blksize = fattr->du.nfs2.blocksize;
1360  	}
1361 
1362 	/* Update attrtimeo value if we're out of the unstable period */
1363 	if (invalid & NFS_INO_INVALID_ATTR) {
1364 		nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
1365 		nfsi->attrtimeo_timestamp = jiffies;
1366 	} else if (time_after(jiffies, nfsi->attrtimeo_timestamp+nfsi->attrtimeo)) {
1367 		if ((nfsi->attrtimeo <<= 1) > NFS_MAXATTRTIMEO(inode))
1368 			nfsi->attrtimeo = NFS_MAXATTRTIMEO(inode);
1369 		nfsi->attrtimeo_timestamp = jiffies;
1370 	}
1371 	/* Don't invalidate the data if we were to blame */
1372 	if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)
1373 				|| S_ISLNK(inode->i_mode)))
1374 		invalid &= ~NFS_INO_INVALID_DATA;
1375 	if (!nfs_have_delegation(inode, FMODE_READ))
1376 		nfsi->flags |= invalid;
1377 
1378 	return 0;
1379  out_changed:
1380 	/*
1381 	 * Big trouble! The inode has become a different object.
1382 	 */
1383 #ifdef NFS_PARANOIA
1384 	printk(KERN_DEBUG "%s: inode %ld mode changed, %07o to %07o\n",
1385 			__FUNCTION__, inode->i_ino, inode->i_mode, fattr->mode);
1386 #endif
1387 	/*
1388 	 * No need to worry about unhashing the dentry, as the
1389 	 * lookup validation will know that the inode is bad.
1390 	 * (But we fall through to invalidate the caches.)
1391 	 */
1392 	nfs_invalidate_inode(inode);
1393  out_err:
1394 	NFS_FLAGS(inode) |= NFS_INO_STALE;
1395 	return -ESTALE;
1396 }
1397 
1398 /*
1399  * File system information
1400  */
1401 
1402 static int nfs_set_super(struct super_block *s, void *data)
1403 {
1404 	s->s_fs_info = data;
1405 	return set_anon_super(s, data);
1406 }
1407 
1408 static int nfs_compare_super(struct super_block *sb, void *data)
1409 {
1410 	struct nfs_server *server = data;
1411 	struct nfs_server *old = NFS_SB(sb);
1412 
1413 	if (old->addr.sin_addr.s_addr != server->addr.sin_addr.s_addr)
1414 		return 0;
1415 	if (old->addr.sin_port != server->addr.sin_port)
1416 		return 0;
1417 	return !nfs_compare_fh(&old->fh, &server->fh);
1418 }
1419 
1420 static struct super_block *nfs_get_sb(struct file_system_type *fs_type,
1421 	int flags, const char *dev_name, void *raw_data)
1422 {
1423 	int error;
1424 	struct nfs_server *server = NULL;
1425 	struct super_block *s;
1426 	struct nfs_fh *root;
1427 	struct nfs_mount_data *data = raw_data;
1428 
1429 	s = ERR_PTR(-EINVAL);
1430 	if (data == NULL) {
1431 		dprintk("%s: missing data argument\n", __FUNCTION__);
1432 		goto out_err;
1433 	}
1434 	if (data->version <= 0 || data->version > NFS_MOUNT_VERSION) {
1435 		dprintk("%s: bad mount version\n", __FUNCTION__);
1436 		goto out_err;
1437 	}
1438 	switch (data->version) {
1439 		case 1:
1440 			data->namlen = 0;
1441 		case 2:
1442 			data->bsize  = 0;
1443 		case 3:
1444 			if (data->flags & NFS_MOUNT_VER3) {
1445 				dprintk("%s: mount structure version %d does not support NFSv3\n",
1446 						__FUNCTION__,
1447 						data->version);
1448 				goto out_err;
1449 			}
1450 			data->root.size = NFS2_FHSIZE;
1451 			memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1452 		case 4:
1453 			if (data->flags & NFS_MOUNT_SECFLAVOUR) {
1454 				dprintk("%s: mount structure version %d does not support strong security\n",
1455 						__FUNCTION__,
1456 						data->version);
1457 				goto out_err;
1458 			}
1459 		case 5:
1460 			memset(data->context, 0, sizeof(data->context));
1461 	}
1462 #ifndef CONFIG_NFS_V3
1463 	/* If NFSv3 is not compiled in, return -EPROTONOSUPPORT */
1464 	s = ERR_PTR(-EPROTONOSUPPORT);
1465 	if (data->flags & NFS_MOUNT_VER3) {
1466 		dprintk("%s: NFSv3 not compiled into kernel\n", __FUNCTION__);
1467 		goto out_err;
1468 	}
1469 #endif /* CONFIG_NFS_V3 */
1470 
1471 	s = ERR_PTR(-ENOMEM);
1472 	server = kmalloc(sizeof(struct nfs_server), GFP_KERNEL);
1473 	if (!server)
1474 		goto out_err;
1475 	memset(server, 0, sizeof(struct nfs_server));
1476 	/* Zero out the NFS state stuff */
1477 	init_nfsv4_state(server);
1478 	server->client = server->client_sys = server->client_acl = ERR_PTR(-EINVAL);
1479 
1480 	root = &server->fh;
1481 	if (data->flags & NFS_MOUNT_VER3)
1482 		root->size = data->root.size;
1483 	else
1484 		root->size = NFS2_FHSIZE;
1485 	s = ERR_PTR(-EINVAL);
1486 	if (root->size > sizeof(root->data)) {
1487 		dprintk("%s: invalid root filehandle\n", __FUNCTION__);
1488 		goto out_err;
1489 	}
1490 	memcpy(root->data, data->root.data, root->size);
1491 
1492 	/* We now require that the mount process passes the remote address */
1493 	memcpy(&server->addr, &data->addr, sizeof(server->addr));
1494 	if (server->addr.sin_addr.s_addr == INADDR_ANY) {
1495 		dprintk("%s: mount program didn't pass remote address!\n",
1496 				__FUNCTION__);
1497 		goto out_err;
1498 	}
1499 
1500 	/* Fire up rpciod if not yet running */
1501 	s = ERR_PTR(rpciod_up());
1502 	if (IS_ERR(s)) {
1503 		dprintk("%s: couldn't start rpciod! Error = %ld\n",
1504 				__FUNCTION__, PTR_ERR(s));
1505 		goto out_err;
1506 	}
1507 
1508 	s = sget(fs_type, nfs_compare_super, nfs_set_super, server);
1509 	if (IS_ERR(s) || s->s_root)
1510 		goto out_rpciod_down;
1511 
1512 	s->s_flags = flags;
1513 
1514 	error = nfs_fill_super(s, data, flags & MS_VERBOSE ? 1 : 0);
1515 	if (error) {
1516 		up_write(&s->s_umount);
1517 		deactivate_super(s);
1518 		return ERR_PTR(error);
1519 	}
1520 	s->s_flags |= MS_ACTIVE;
1521 	return s;
1522 out_rpciod_down:
1523 	rpciod_down();
1524 out_err:
1525 	kfree(server);
1526 	return s;
1527 }
1528 
1529 static void nfs_kill_super(struct super_block *s)
1530 {
1531 	struct nfs_server *server = NFS_SB(s);
1532 
1533 	kill_anon_super(s);
1534 
1535 	if (!IS_ERR(server->client))
1536 		rpc_shutdown_client(server->client);
1537 	if (!IS_ERR(server->client_sys))
1538 		rpc_shutdown_client(server->client_sys);
1539 	if (!IS_ERR(server->client_acl))
1540 		rpc_shutdown_client(server->client_acl);
1541 
1542 	if (!(server->flags & NFS_MOUNT_NONLM))
1543 		lockd_down();	/* release rpc.lockd */
1544 
1545 	rpciod_down();		/* release rpciod */
1546 
1547 	if (server->hostname != NULL)
1548 		kfree(server->hostname);
1549 	kfree(server);
1550 }
1551 
1552 static struct file_system_type nfs_fs_type = {
1553 	.owner		= THIS_MODULE,
1554 	.name		= "nfs",
1555 	.get_sb		= nfs_get_sb,
1556 	.kill_sb	= nfs_kill_super,
1557 	.fs_flags	= FS_ODD_RENAME|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
1558 };
1559 
1560 #ifdef CONFIG_NFS_V4
1561 
1562 static void nfs4_clear_inode(struct inode *);
1563 
1564 
1565 static struct super_operations nfs4_sops = {
1566 	.alloc_inode	= nfs_alloc_inode,
1567 	.destroy_inode	= nfs_destroy_inode,
1568 	.write_inode	= nfs_write_inode,
1569 	.delete_inode	= nfs_delete_inode,
1570 	.statfs		= nfs_statfs,
1571 	.clear_inode	= nfs4_clear_inode,
1572 	.umount_begin	= nfs_umount_begin,
1573 	.show_options	= nfs_show_options,
1574 };
1575 
1576 /*
1577  * Clean out any remaining NFSv4 state that might be left over due
1578  * to open() calls that passed nfs_atomic_lookup, but failed to call
1579  * nfs_open().
1580  */
1581 static void nfs4_clear_inode(struct inode *inode)
1582 {
1583 	struct nfs_inode *nfsi = NFS_I(inode);
1584 
1585 	/* If we are holding a delegation, return it! */
1586 	if (nfsi->delegation != NULL)
1587 		nfs_inode_return_delegation(inode);
1588 	/* First call standard NFS clear_inode() code */
1589 	nfs_clear_inode(inode);
1590 	/* Now clear out any remaining state */
1591 	while (!list_empty(&nfsi->open_states)) {
1592 		struct nfs4_state *state;
1593 
1594 		state = list_entry(nfsi->open_states.next,
1595 				struct nfs4_state,
1596 				inode_states);
1597 		dprintk("%s(%s/%Ld): found unclaimed NFSv4 state %p\n",
1598 				__FUNCTION__,
1599 				inode->i_sb->s_id,
1600 				(long long)NFS_FILEID(inode),
1601 				state);
1602 		BUG_ON(atomic_read(&state->count) != 1);
1603 		nfs4_close_state(state, state->state);
1604 	}
1605 }
1606 
1607 
1608 static int nfs4_fill_super(struct super_block *sb, struct nfs4_mount_data *data, int silent)
1609 {
1610 	struct nfs_server *server;
1611 	struct nfs4_client *clp = NULL;
1612 	struct rpc_xprt *xprt = NULL;
1613 	struct rpc_clnt *clnt = NULL;
1614 	struct rpc_timeout timeparms;
1615 	rpc_authflavor_t authflavour;
1616 	int proto, err = -EIO;
1617 
1618 	sb->s_blocksize_bits = 0;
1619 	sb->s_blocksize = 0;
1620 	server = NFS_SB(sb);
1621 	if (data->rsize != 0)
1622 		server->rsize = nfs_block_size(data->rsize, NULL);
1623 	if (data->wsize != 0)
1624 		server->wsize = nfs_block_size(data->wsize, NULL);
1625 	server->flags = data->flags & NFS_MOUNT_FLAGMASK;
1626 	server->caps = NFS_CAP_ATOMIC_OPEN;
1627 
1628 	server->acregmin = data->acregmin*HZ;
1629 	server->acregmax = data->acregmax*HZ;
1630 	server->acdirmin = data->acdirmin*HZ;
1631 	server->acdirmax = data->acdirmax*HZ;
1632 
1633 	server->rpc_ops = &nfs_v4_clientops;
1634 	/* Initialize timeout values */
1635 
1636 	timeparms.to_initval = data->timeo * HZ / 10;
1637 	timeparms.to_retries = data->retrans;
1638 	timeparms.to_exponential = 1;
1639 	if (!timeparms.to_retries)
1640 		timeparms.to_retries = 5;
1641 
1642 	proto = data->proto;
1643 	/* Which IP protocol do we use? */
1644 	switch (proto) {
1645 	case IPPROTO_TCP:
1646 		timeparms.to_maxval  = RPC_MAX_TCP_TIMEOUT;
1647 		if (!timeparms.to_initval)
1648 			timeparms.to_initval = 600 * HZ / 10;
1649 		break;
1650 	case IPPROTO_UDP:
1651 		timeparms.to_maxval  = RPC_MAX_UDP_TIMEOUT;
1652 		if (!timeparms.to_initval)
1653 			timeparms.to_initval = 11 * HZ / 10;
1654 		break;
1655 	default:
1656 		return -EINVAL;
1657 	}
1658 
1659 	clp = nfs4_get_client(&server->addr.sin_addr);
1660 	if (!clp) {
1661 		dprintk("%s: failed to create NFS4 client.\n", __FUNCTION__);
1662 		return -EIO;
1663 	}
1664 
1665 	/* Now create transport and client */
1666 	authflavour = RPC_AUTH_UNIX;
1667 	if (data->auth_flavourlen != 0) {
1668 		if (data->auth_flavourlen != 1) {
1669 			dprintk("%s: Invalid number of RPC auth flavours %d.\n",
1670 					__FUNCTION__, data->auth_flavourlen);
1671 			err = -EINVAL;
1672 			goto out_fail;
1673 		}
1674 		if (copy_from_user(&authflavour, data->auth_flavours, sizeof(authflavour))) {
1675 			err = -EFAULT;
1676 			goto out_fail;
1677 		}
1678 	}
1679 
1680 	down_write(&clp->cl_sem);
1681 	if (IS_ERR(clp->cl_rpcclient)) {
1682 		xprt = xprt_create_proto(proto, &server->addr, &timeparms);
1683 		if (IS_ERR(xprt)) {
1684 			up_write(&clp->cl_sem);
1685 			err = PTR_ERR(xprt);
1686 			dprintk("%s: cannot create RPC transport. Error = %d\n",
1687 					__FUNCTION__, err);
1688 			goto out_fail;
1689 		}
1690 		clnt = rpc_create_client(xprt, server->hostname, &nfs_program,
1691 				server->rpc_ops->version, authflavour);
1692 		if (IS_ERR(clnt)) {
1693 			up_write(&clp->cl_sem);
1694 			err = PTR_ERR(clnt);
1695 			dprintk("%s: cannot create RPC client. Error = %d\n",
1696 					__FUNCTION__, err);
1697 			goto out_fail;
1698 		}
1699 		clnt->cl_intr     = 1;
1700 		clnt->cl_softrtry = 1;
1701 		clnt->cl_chatty   = 1;
1702 		clp->cl_rpcclient = clnt;
1703 		clp->cl_cred = rpcauth_lookupcred(clnt->cl_auth, 0);
1704 		if (IS_ERR(clp->cl_cred)) {
1705 			up_write(&clp->cl_sem);
1706 			err = PTR_ERR(clp->cl_cred);
1707 			clp->cl_cred = NULL;
1708 			goto out_fail;
1709 		}
1710 		memcpy(clp->cl_ipaddr, server->ip_addr, sizeof(clp->cl_ipaddr));
1711 		nfs_idmap_new(clp);
1712 	}
1713 	if (list_empty(&clp->cl_superblocks)) {
1714 		err = nfs4_init_client(clp);
1715 		if (err != 0) {
1716 			up_write(&clp->cl_sem);
1717 			goto out_fail;
1718 		}
1719 	}
1720 	list_add_tail(&server->nfs4_siblings, &clp->cl_superblocks);
1721 	clnt = rpc_clone_client(clp->cl_rpcclient);
1722 	if (!IS_ERR(clnt))
1723 			server->nfs4_state = clp;
1724 	up_write(&clp->cl_sem);
1725 	clp = NULL;
1726 
1727 	if (IS_ERR(clnt)) {
1728 		err = PTR_ERR(clnt);
1729 		dprintk("%s: cannot create RPC client. Error = %d\n",
1730 				__FUNCTION__, err);
1731 		return err;
1732 	}
1733 
1734 	server->client    = clnt;
1735 
1736 	if (server->nfs4_state->cl_idmap == NULL) {
1737 		dprintk("%s: failed to create idmapper.\n", __FUNCTION__);
1738 		return -ENOMEM;
1739 	}
1740 
1741 	if (clnt->cl_auth->au_flavor != authflavour) {
1742 		struct rpc_auth *auth;
1743 
1744 		auth = rpcauth_create(authflavour, clnt);
1745 		if (IS_ERR(auth)) {
1746 			dprintk("%s: couldn't create credcache!\n", __FUNCTION__);
1747 			return PTR_ERR(auth);
1748 		}
1749 	}
1750 
1751 	sb->s_time_gran = 1;
1752 
1753 	sb->s_op = &nfs4_sops;
1754 	err = nfs_sb_init(sb, authflavour);
1755 	if (err == 0)
1756 		return 0;
1757 out_fail:
1758 	if (clp)
1759 		nfs4_put_client(clp);
1760 	return err;
1761 }
1762 
1763 static int nfs4_compare_super(struct super_block *sb, void *data)
1764 {
1765 	struct nfs_server *server = data;
1766 	struct nfs_server *old = NFS_SB(sb);
1767 
1768 	if (strcmp(server->hostname, old->hostname) != 0)
1769 		return 0;
1770 	if (strcmp(server->mnt_path, old->mnt_path) != 0)
1771 		return 0;
1772 	return 1;
1773 }
1774 
1775 static void *
1776 nfs_copy_user_string(char *dst, struct nfs_string *src, int maxlen)
1777 {
1778 	void *p = NULL;
1779 
1780 	if (!src->len)
1781 		return ERR_PTR(-EINVAL);
1782 	if (src->len < maxlen)
1783 		maxlen = src->len;
1784 	if (dst == NULL) {
1785 		p = dst = kmalloc(maxlen + 1, GFP_KERNEL);
1786 		if (p == NULL)
1787 			return ERR_PTR(-ENOMEM);
1788 	}
1789 	if (copy_from_user(dst, src->data, maxlen)) {
1790 		if (p != NULL)
1791 			kfree(p);
1792 		return ERR_PTR(-EFAULT);
1793 	}
1794 	dst[maxlen] = '\0';
1795 	return dst;
1796 }
1797 
1798 static struct super_block *nfs4_get_sb(struct file_system_type *fs_type,
1799 	int flags, const char *dev_name, void *raw_data)
1800 {
1801 	int error;
1802 	struct nfs_server *server;
1803 	struct super_block *s;
1804 	struct nfs4_mount_data *data = raw_data;
1805 	void *p;
1806 
1807 	if (data == NULL) {
1808 		dprintk("%s: missing data argument\n", __FUNCTION__);
1809 		return ERR_PTR(-EINVAL);
1810 	}
1811 	if (data->version <= 0 || data->version > NFS4_MOUNT_VERSION) {
1812 		dprintk("%s: bad mount version\n", __FUNCTION__);
1813 		return ERR_PTR(-EINVAL);
1814 	}
1815 
1816 	server = kmalloc(sizeof(struct nfs_server), GFP_KERNEL);
1817 	if (!server)
1818 		return ERR_PTR(-ENOMEM);
1819 	memset(server, 0, sizeof(struct nfs_server));
1820 	/* Zero out the NFS state stuff */
1821 	init_nfsv4_state(server);
1822 	server->client = server->client_sys = server->client_acl = ERR_PTR(-EINVAL);
1823 
1824 	p = nfs_copy_user_string(NULL, &data->hostname, 256);
1825 	if (IS_ERR(p))
1826 		goto out_err;
1827 	server->hostname = p;
1828 
1829 	p = nfs_copy_user_string(NULL, &data->mnt_path, 1024);
1830 	if (IS_ERR(p))
1831 		goto out_err;
1832 	server->mnt_path = p;
1833 
1834 	p = nfs_copy_user_string(server->ip_addr, &data->client_addr,
1835 			sizeof(server->ip_addr) - 1);
1836 	if (IS_ERR(p))
1837 		goto out_err;
1838 
1839 	/* We now require that the mount process passes the remote address */
1840 	if (data->host_addrlen != sizeof(server->addr)) {
1841 		s = ERR_PTR(-EINVAL);
1842 		goto out_free;
1843 	}
1844 	if (copy_from_user(&server->addr, data->host_addr, sizeof(server->addr))) {
1845 		s = ERR_PTR(-EFAULT);
1846 		goto out_free;
1847 	}
1848 	if (server->addr.sin_family != AF_INET ||
1849 	    server->addr.sin_addr.s_addr == INADDR_ANY) {
1850 		dprintk("%s: mount program didn't pass remote IP address!\n",
1851 				__FUNCTION__);
1852 		s = ERR_PTR(-EINVAL);
1853 		goto out_free;
1854 	}
1855 
1856 	/* Fire up rpciod if not yet running */
1857 	s = ERR_PTR(rpciod_up());
1858 	if (IS_ERR(s)) {
1859 		dprintk("%s: couldn't start rpciod! Error = %ld\n",
1860 				__FUNCTION__, PTR_ERR(s));
1861 		goto out_free;
1862 	}
1863 
1864 	s = sget(fs_type, nfs4_compare_super, nfs_set_super, server);
1865 
1866 	if (IS_ERR(s) || s->s_root)
1867 		goto out_free;
1868 
1869 	s->s_flags = flags;
1870 
1871 	error = nfs4_fill_super(s, data, flags & MS_VERBOSE ? 1 : 0);
1872 	if (error) {
1873 		up_write(&s->s_umount);
1874 		deactivate_super(s);
1875 		return ERR_PTR(error);
1876 	}
1877 	s->s_flags |= MS_ACTIVE;
1878 	return s;
1879 out_err:
1880 	s = (struct super_block *)p;
1881 out_free:
1882 	if (server->mnt_path)
1883 		kfree(server->mnt_path);
1884 	if (server->hostname)
1885 		kfree(server->hostname);
1886 	kfree(server);
1887 	return s;
1888 }
1889 
1890 static void nfs4_kill_super(struct super_block *sb)
1891 {
1892 	struct nfs_server *server = NFS_SB(sb);
1893 
1894 	nfs_return_all_delegations(sb);
1895 	kill_anon_super(sb);
1896 
1897 	nfs4_renewd_prepare_shutdown(server);
1898 
1899 	if (server->client != NULL && !IS_ERR(server->client))
1900 		rpc_shutdown_client(server->client);
1901 	rpciod_down();		/* release rpciod */
1902 
1903 	destroy_nfsv4_state(server);
1904 
1905 	if (server->hostname != NULL)
1906 		kfree(server->hostname);
1907 	kfree(server);
1908 }
1909 
1910 static struct file_system_type nfs4_fs_type = {
1911 	.owner		= THIS_MODULE,
1912 	.name		= "nfs4",
1913 	.get_sb		= nfs4_get_sb,
1914 	.kill_sb	= nfs4_kill_super,
1915 	.fs_flags	= FS_ODD_RENAME|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
1916 };
1917 
1918 #define nfs4_init_once(nfsi) \
1919 	do { \
1920 		INIT_LIST_HEAD(&(nfsi)->open_states); \
1921 		nfsi->delegation = NULL; \
1922 		nfsi->delegation_state = 0; \
1923 		init_rwsem(&nfsi->rwsem); \
1924 	} while(0)
1925 #define register_nfs4fs() register_filesystem(&nfs4_fs_type)
1926 #define unregister_nfs4fs() unregister_filesystem(&nfs4_fs_type)
1927 #else
1928 #define nfs4_init_once(nfsi) \
1929 	do { } while (0)
1930 #define register_nfs4fs() (0)
1931 #define unregister_nfs4fs()
1932 #endif
1933 
1934 extern int nfs_init_nfspagecache(void);
1935 extern void nfs_destroy_nfspagecache(void);
1936 extern int nfs_init_readpagecache(void);
1937 extern void nfs_destroy_readpagecache(void);
1938 extern int nfs_init_writepagecache(void);
1939 extern void nfs_destroy_writepagecache(void);
1940 #ifdef CONFIG_NFS_DIRECTIO
1941 extern int nfs_init_directcache(void);
1942 extern void nfs_destroy_directcache(void);
1943 #endif
1944 
1945 static kmem_cache_t * nfs_inode_cachep;
1946 
1947 static struct inode *nfs_alloc_inode(struct super_block *sb)
1948 {
1949 	struct nfs_inode *nfsi;
1950 	nfsi = (struct nfs_inode *)kmem_cache_alloc(nfs_inode_cachep, SLAB_KERNEL);
1951 	if (!nfsi)
1952 		return NULL;
1953 	nfsi->flags = 0;
1954 #ifdef CONFIG_NFS_V3_ACL
1955 	nfsi->acl_access = ERR_PTR(-EAGAIN);
1956 	nfsi->acl_default = ERR_PTR(-EAGAIN);
1957 #endif
1958 #ifdef CONFIG_NFS_V4
1959 	nfsi->nfs4_acl = NULL;
1960 #endif /* CONFIG_NFS_V4 */
1961 	return &nfsi->vfs_inode;
1962 }
1963 
1964 static void nfs_destroy_inode(struct inode *inode)
1965 {
1966 	kmem_cache_free(nfs_inode_cachep, NFS_I(inode));
1967 }
1968 
1969 static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
1970 {
1971 	struct nfs_inode *nfsi = (struct nfs_inode *) foo;
1972 
1973 	if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
1974 	    SLAB_CTOR_CONSTRUCTOR) {
1975 		inode_init_once(&nfsi->vfs_inode);
1976 		spin_lock_init(&nfsi->req_lock);
1977 		INIT_LIST_HEAD(&nfsi->dirty);
1978 		INIT_LIST_HEAD(&nfsi->commit);
1979 		INIT_LIST_HEAD(&nfsi->open_files);
1980 		INIT_RADIX_TREE(&nfsi->nfs_page_tree, GFP_ATOMIC);
1981 		atomic_set(&nfsi->data_updates, 0);
1982 		nfsi->ndirty = 0;
1983 		nfsi->ncommit = 0;
1984 		nfsi->npages = 0;
1985 		init_waitqueue_head(&nfsi->nfs_i_wait);
1986 		nfs4_init_once(nfsi);
1987 	}
1988 }
1989 
1990 static int nfs_init_inodecache(void)
1991 {
1992 	nfs_inode_cachep = kmem_cache_create("nfs_inode_cache",
1993 					     sizeof(struct nfs_inode),
1994 					     0, SLAB_RECLAIM_ACCOUNT,
1995 					     init_once, NULL);
1996 	if (nfs_inode_cachep == NULL)
1997 		return -ENOMEM;
1998 
1999 	return 0;
2000 }
2001 
2002 static void nfs_destroy_inodecache(void)
2003 {
2004 	if (kmem_cache_destroy(nfs_inode_cachep))
2005 		printk(KERN_INFO "nfs_inode_cache: not all structures were freed\n");
2006 }
2007 
2008 /*
2009  * Initialize NFS
2010  */
2011 static int __init init_nfs_fs(void)
2012 {
2013 	int err;
2014 
2015 	err = nfs_init_nfspagecache();
2016 	if (err)
2017 		goto out4;
2018 
2019 	err = nfs_init_inodecache();
2020 	if (err)
2021 		goto out3;
2022 
2023 	err = nfs_init_readpagecache();
2024 	if (err)
2025 		goto out2;
2026 
2027 	err = nfs_init_writepagecache();
2028 	if (err)
2029 		goto out1;
2030 
2031 #ifdef CONFIG_NFS_DIRECTIO
2032 	err = nfs_init_directcache();
2033 	if (err)
2034 		goto out0;
2035 #endif
2036 
2037 #ifdef CONFIG_PROC_FS
2038 	rpc_proc_register(&nfs_rpcstat);
2039 #endif
2040         err = register_filesystem(&nfs_fs_type);
2041 	if (err)
2042 		goto out;
2043 	if ((err = register_nfs4fs()) != 0)
2044 		goto out;
2045 	return 0;
2046 out:
2047 #ifdef CONFIG_PROC_FS
2048 	rpc_proc_unregister("nfs");
2049 #endif
2050 	nfs_destroy_writepagecache();
2051 #ifdef CONFIG_NFS_DIRECTIO
2052 out0:
2053 	nfs_destroy_directcache();
2054 #endif
2055 out1:
2056 	nfs_destroy_readpagecache();
2057 out2:
2058 	nfs_destroy_inodecache();
2059 out3:
2060 	nfs_destroy_nfspagecache();
2061 out4:
2062 	return err;
2063 }
2064 
2065 static void __exit exit_nfs_fs(void)
2066 {
2067 #ifdef CONFIG_NFS_DIRECTIO
2068 	nfs_destroy_directcache();
2069 #endif
2070 	nfs_destroy_writepagecache();
2071 	nfs_destroy_readpagecache();
2072 	nfs_destroy_inodecache();
2073 	nfs_destroy_nfspagecache();
2074 #ifdef CONFIG_PROC_FS
2075 	rpc_proc_unregister("nfs");
2076 #endif
2077 	unregister_filesystem(&nfs_fs_type);
2078 	unregister_nfs4fs();
2079 }
2080 
2081 /* Not quite true; I just maintain it */
2082 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
2083 MODULE_LICENSE("GPL");
2084 
2085 module_init(init_nfs_fs)
2086 module_exit(exit_nfs_fs)
2087