xref: /linux/fs/nfs/super.c (revision 14b42963f64b98ab61fa9723c03d71aa5ef4f862)
1 /*
2  *  linux/fs/nfs/super.c
3  *
4  *  Copyright (C) 1992  Rick Sladkey
5  *
6  *  nfs 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  *  Split from inode.c by David Howells <dhowells@redhat.com>
15  *
16  */
17 
18 #include <linux/config.h>
19 #include <linux/module.h>
20 #include <linux/init.h>
21 
22 #include <linux/time.h>
23 #include <linux/kernel.h>
24 #include <linux/mm.h>
25 #include <linux/string.h>
26 #include <linux/stat.h>
27 #include <linux/errno.h>
28 #include <linux/unistd.h>
29 #include <linux/sunrpc/clnt.h>
30 #include <linux/sunrpc/stats.h>
31 #include <linux/sunrpc/metrics.h>
32 #include <linux/nfs_fs.h>
33 #include <linux/nfs_mount.h>
34 #include <linux/nfs4_mount.h>
35 #include <linux/lockd/bind.h>
36 #include <linux/smp_lock.h>
37 #include <linux/seq_file.h>
38 #include <linux/mount.h>
39 #include <linux/nfs_idmap.h>
40 #include <linux/vfs.h>
41 #include <linux/inet.h>
42 #include <linux/nfs_xdr.h>
43 
44 #include <asm/system.h>
45 #include <asm/uaccess.h>
46 
47 #include "nfs4_fs.h"
48 #include "callback.h"
49 #include "delegation.h"
50 #include "iostat.h"
51 #include "internal.h"
52 
53 #define NFSDBG_FACILITY		NFSDBG_VFS
54 
55 /* Maximum number of readahead requests
56  * FIXME: this should really be a sysctl so that users may tune it to suit
57  *        their needs. People that do NFS over a slow network, might for
58  *        instance want to reduce it to something closer to 1 for improved
59  *        interactive response.
60  */
61 #define NFS_MAX_READAHEAD	(RPC_DEF_SLOT_TABLE - 1)
62 
63 /*
64  * RPC cruft for NFS
65  */
66 static struct rpc_version * nfs_version[] = {
67 	NULL,
68 	NULL,
69 	&nfs_version2,
70 #if defined(CONFIG_NFS_V3)
71 	&nfs_version3,
72 #elif defined(CONFIG_NFS_V4)
73 	NULL,
74 #endif
75 #if defined(CONFIG_NFS_V4)
76 	&nfs_version4,
77 #endif
78 };
79 
80 static struct rpc_program nfs_program = {
81 	.name			= "nfs",
82 	.number			= NFS_PROGRAM,
83 	.nrvers			= ARRAY_SIZE(nfs_version),
84 	.version		= nfs_version,
85 	.stats			= &nfs_rpcstat,
86 	.pipe_dir_name		= "/nfs",
87 };
88 
89 struct rpc_stat nfs_rpcstat = {
90 	.program		= &nfs_program
91 };
92 
93 
94 #ifdef CONFIG_NFS_V3_ACL
95 static struct rpc_stat		nfsacl_rpcstat = { &nfsacl_program };
96 static struct rpc_version *	nfsacl_version[] = {
97 	[3]			= &nfsacl_version3,
98 };
99 
100 struct rpc_program		nfsacl_program = {
101 	.name =			"nfsacl",
102 	.number =		NFS_ACL_PROGRAM,
103 	.nrvers =		ARRAY_SIZE(nfsacl_version),
104 	.version =		nfsacl_version,
105 	.stats =		&nfsacl_rpcstat,
106 };
107 #endif  /* CONFIG_NFS_V3_ACL */
108 
109 static void nfs_umount_begin(struct vfsmount *, int);
110 static int  nfs_statfs(struct dentry *, struct kstatfs *);
111 static int  nfs_show_options(struct seq_file *, struct vfsmount *);
112 static int  nfs_show_stats(struct seq_file *, struct vfsmount *);
113 static int nfs_get_sb(struct file_system_type *, int, const char *, void *, struct vfsmount *);
114 static int nfs_clone_nfs_sb(struct file_system_type *fs_type,
115 		int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
116 static void nfs_kill_super(struct super_block *);
117 
118 static struct file_system_type nfs_fs_type = {
119 	.owner		= THIS_MODULE,
120 	.name		= "nfs",
121 	.get_sb		= nfs_get_sb,
122 	.kill_sb	= nfs_kill_super,
123 	.fs_flags	= FS_ODD_RENAME|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
124 };
125 
126 struct file_system_type clone_nfs_fs_type = {
127 	.owner		= THIS_MODULE,
128 	.name		= "nfs",
129 	.get_sb		= nfs_clone_nfs_sb,
130 	.kill_sb	= nfs_kill_super,
131 	.fs_flags	= FS_ODD_RENAME|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
132 };
133 
134 static struct super_operations nfs_sops = {
135 	.alloc_inode	= nfs_alloc_inode,
136 	.destroy_inode	= nfs_destroy_inode,
137 	.write_inode	= nfs_write_inode,
138 	.statfs		= nfs_statfs,
139 	.clear_inode	= nfs_clear_inode,
140 	.umount_begin	= nfs_umount_begin,
141 	.show_options	= nfs_show_options,
142 	.show_stats	= nfs_show_stats,
143 };
144 
145 #ifdef CONFIG_NFS_V4
146 static int nfs4_get_sb(struct file_system_type *fs_type,
147 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
148 static int nfs_clone_nfs4_sb(struct file_system_type *fs_type,
149 		int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
150 static int nfs_referral_nfs4_sb(struct file_system_type *fs_type,
151 		int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
152 static void nfs4_kill_super(struct super_block *sb);
153 
154 static struct file_system_type nfs4_fs_type = {
155 	.owner		= THIS_MODULE,
156 	.name		= "nfs4",
157 	.get_sb		= nfs4_get_sb,
158 	.kill_sb	= nfs4_kill_super,
159 	.fs_flags	= FS_ODD_RENAME|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
160 };
161 
162 struct file_system_type clone_nfs4_fs_type = {
163 	.owner		= THIS_MODULE,
164 	.name		= "nfs4",
165 	.get_sb		= nfs_clone_nfs4_sb,
166 	.kill_sb	= nfs4_kill_super,
167 	.fs_flags	= FS_ODD_RENAME|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
168 };
169 
170 struct file_system_type nfs_referral_nfs4_fs_type = {
171 	.owner		= THIS_MODULE,
172 	.name		= "nfs4",
173 	.get_sb		= nfs_referral_nfs4_sb,
174 	.kill_sb	= nfs4_kill_super,
175 	.fs_flags	= FS_ODD_RENAME|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
176 };
177 
178 static struct super_operations nfs4_sops = {
179 	.alloc_inode	= nfs_alloc_inode,
180 	.destroy_inode	= nfs_destroy_inode,
181 	.write_inode	= nfs_write_inode,
182 	.statfs		= nfs_statfs,
183 	.clear_inode	= nfs4_clear_inode,
184 	.umount_begin	= nfs_umount_begin,
185 	.show_options	= nfs_show_options,
186 	.show_stats	= nfs_show_stats,
187 };
188 #endif
189 
190 #ifdef CONFIG_NFS_V4
191 static const int nfs_set_port_min = 0;
192 static const int nfs_set_port_max = 65535;
193 
194 static int param_set_port(const char *val, struct kernel_param *kp)
195 {
196 	char *endp;
197 	int num = simple_strtol(val, &endp, 0);
198 	if (endp == val || *endp || num < nfs_set_port_min || num > nfs_set_port_max)
199 		return -EINVAL;
200 	*((int *)kp->arg) = num;
201 	return 0;
202 }
203 
204 module_param_call(callback_tcpport, param_set_port, param_get_int,
205 		 &nfs_callback_set_tcpport, 0644);
206 #endif
207 
208 #ifdef CONFIG_NFS_V4
209 static int param_set_idmap_timeout(const char *val, struct kernel_param *kp)
210 {
211 	char *endp;
212 	int num = simple_strtol(val, &endp, 0);
213 	int jif = num * HZ;
214 	if (endp == val || *endp || num < 0 || jif < num)
215 		return -EINVAL;
216 	*((int *)kp->arg) = jif;
217 	return 0;
218 }
219 
220 module_param_call(idmap_cache_timeout, param_set_idmap_timeout, param_get_int,
221 		 &nfs_idmap_cache_timeout, 0644);
222 #endif
223 
224 /*
225  * Register the NFS filesystems
226  */
227 int __init register_nfs_fs(void)
228 {
229 	int ret;
230 
231         ret = register_filesystem(&nfs_fs_type);
232 	if (ret < 0)
233 		goto error_0;
234 
235 #ifdef CONFIG_NFS_V4
236 	ret = nfs_register_sysctl();
237 	if (ret < 0)
238 		goto error_1;
239 	ret = register_filesystem(&nfs4_fs_type);
240 	if (ret < 0)
241 		goto error_2;
242 #endif
243 	return 0;
244 
245 #ifdef CONFIG_NFS_V4
246 error_2:
247 	nfs_unregister_sysctl();
248 error_1:
249 	unregister_filesystem(&nfs_fs_type);
250 #endif
251 error_0:
252 	return ret;
253 }
254 
255 /*
256  * Unregister the NFS filesystems
257  */
258 void __exit unregister_nfs_fs(void)
259 {
260 #ifdef CONFIG_NFS_V4
261 	unregister_filesystem(&nfs4_fs_type);
262 	nfs_unregister_sysctl();
263 #endif
264 	unregister_filesystem(&nfs_fs_type);
265 }
266 
267 /*
268  * Deliver file system statistics to userspace
269  */
270 static int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
271 {
272 	struct super_block *sb = dentry->d_sb;
273 	struct nfs_server *server = NFS_SB(sb);
274 	unsigned char blockbits;
275 	unsigned long blockres;
276 	struct nfs_fh *rootfh = NFS_FH(sb->s_root->d_inode);
277 	struct nfs_fattr fattr;
278 	struct nfs_fsstat res = {
279 			.fattr = &fattr,
280 	};
281 	int error;
282 
283 	lock_kernel();
284 
285 	error = server->rpc_ops->statfs(server, rootfh, &res);
286 	buf->f_type = NFS_SUPER_MAGIC;
287 	if (error < 0)
288 		goto out_err;
289 
290 	/*
291 	 * Current versions of glibc do not correctly handle the
292 	 * case where f_frsize != f_bsize.  Eventually we want to
293 	 * report the value of wtmult in this field.
294 	 */
295 	buf->f_frsize = sb->s_blocksize;
296 
297 	/*
298 	 * On most *nix systems, f_blocks, f_bfree, and f_bavail
299 	 * are reported in units of f_frsize.  Linux hasn't had
300 	 * an f_frsize field in its statfs struct until recently,
301 	 * thus historically Linux's sys_statfs reports these
302 	 * fields in units of f_bsize.
303 	 */
304 	buf->f_bsize = sb->s_blocksize;
305 	blockbits = sb->s_blocksize_bits;
306 	blockres = (1 << blockbits) - 1;
307 	buf->f_blocks = (res.tbytes + blockres) >> blockbits;
308 	buf->f_bfree = (res.fbytes + blockres) >> blockbits;
309 	buf->f_bavail = (res.abytes + blockres) >> blockbits;
310 
311 	buf->f_files = res.tfiles;
312 	buf->f_ffree = res.afiles;
313 
314 	buf->f_namelen = server->namelen;
315  out:
316 	unlock_kernel();
317 	return 0;
318 
319  out_err:
320 	dprintk("%s: statfs error = %d\n", __FUNCTION__, -error);
321 	buf->f_bsize = buf->f_blocks = buf->f_bfree = buf->f_bavail = -1;
322 	goto out;
323 
324 }
325 
326 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
327 {
328 	static struct {
329 		rpc_authflavor_t flavour;
330 		const char *str;
331 	} sec_flavours[] = {
332 		{ RPC_AUTH_NULL, "null" },
333 		{ RPC_AUTH_UNIX, "sys" },
334 		{ RPC_AUTH_GSS_KRB5, "krb5" },
335 		{ RPC_AUTH_GSS_KRB5I, "krb5i" },
336 		{ RPC_AUTH_GSS_KRB5P, "krb5p" },
337 		{ RPC_AUTH_GSS_LKEY, "lkey" },
338 		{ RPC_AUTH_GSS_LKEYI, "lkeyi" },
339 		{ RPC_AUTH_GSS_LKEYP, "lkeyp" },
340 		{ RPC_AUTH_GSS_SPKM, "spkm" },
341 		{ RPC_AUTH_GSS_SPKMI, "spkmi" },
342 		{ RPC_AUTH_GSS_SPKMP, "spkmp" },
343 		{ -1, "unknown" }
344 	};
345 	int i;
346 
347 	for (i=0; sec_flavours[i].flavour != -1; i++) {
348 		if (sec_flavours[i].flavour == flavour)
349 			break;
350 	}
351 	return sec_flavours[i].str;
352 }
353 
354 /*
355  * Describe the mount options in force on this server representation
356  */
357 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss, int showdefaults)
358 {
359 	static struct proc_nfs_info {
360 		int flag;
361 		char *str;
362 		char *nostr;
363 	} nfs_info[] = {
364 		{ NFS_MOUNT_SOFT, ",soft", ",hard" },
365 		{ NFS_MOUNT_INTR, ",intr", "" },
366 		{ NFS_MOUNT_NOCTO, ",nocto", "" },
367 		{ NFS_MOUNT_NOAC, ",noac", "" },
368 		{ NFS_MOUNT_NONLM, ",nolock", "" },
369 		{ NFS_MOUNT_NOACL, ",noacl", "" },
370 		{ 0, NULL, NULL }
371 	};
372 	struct proc_nfs_info *nfs_infop;
373 	char buf[12];
374 	char *proto;
375 
376 	seq_printf(m, ",vers=%d", nfss->rpc_ops->version);
377 	seq_printf(m, ",rsize=%d", nfss->rsize);
378 	seq_printf(m, ",wsize=%d", nfss->wsize);
379 	if (nfss->acregmin != 3*HZ || showdefaults)
380 		seq_printf(m, ",acregmin=%d", nfss->acregmin/HZ);
381 	if (nfss->acregmax != 60*HZ || showdefaults)
382 		seq_printf(m, ",acregmax=%d", nfss->acregmax/HZ);
383 	if (nfss->acdirmin != 30*HZ || showdefaults)
384 		seq_printf(m, ",acdirmin=%d", nfss->acdirmin/HZ);
385 	if (nfss->acdirmax != 60*HZ || showdefaults)
386 		seq_printf(m, ",acdirmax=%d", nfss->acdirmax/HZ);
387 	for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
388 		if (nfss->flags & nfs_infop->flag)
389 			seq_puts(m, nfs_infop->str);
390 		else
391 			seq_puts(m, nfs_infop->nostr);
392 	}
393 	switch (nfss->client->cl_xprt->prot) {
394 		case IPPROTO_TCP:
395 			proto = "tcp";
396 			break;
397 		case IPPROTO_UDP:
398 			proto = "udp";
399 			break;
400 		default:
401 			snprintf(buf, sizeof(buf), "%u", nfss->client->cl_xprt->prot);
402 			proto = buf;
403 	}
404 	seq_printf(m, ",proto=%s", proto);
405 	seq_printf(m, ",timeo=%lu", 10U * nfss->retrans_timeo / HZ);
406 	seq_printf(m, ",retrans=%u", nfss->retrans_count);
407 	seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
408 }
409 
410 /*
411  * Describe the mount options on this VFS mountpoint
412  */
413 static int nfs_show_options(struct seq_file *m, struct vfsmount *mnt)
414 {
415 	struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
416 
417 	nfs_show_mount_options(m, nfss, 0);
418 
419 	seq_puts(m, ",addr=");
420 	seq_escape(m, nfss->hostname, " \t\n\\");
421 
422 	return 0;
423 }
424 
425 /*
426  * Present statistical information for this VFS mountpoint
427  */
428 static int nfs_show_stats(struct seq_file *m, struct vfsmount *mnt)
429 {
430 	int i, cpu;
431 	struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
432 	struct rpc_auth *auth = nfss->client->cl_auth;
433 	struct nfs_iostats totals = { };
434 
435 	seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
436 
437 	/*
438 	 * Display all mount option settings
439 	 */
440 	seq_printf(m, "\n\topts:\t");
441 	seq_puts(m, mnt->mnt_sb->s_flags & MS_RDONLY ? "ro" : "rw");
442 	seq_puts(m, mnt->mnt_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
443 	seq_puts(m, mnt->mnt_sb->s_flags & MS_NOATIME ? ",noatime" : "");
444 	seq_puts(m, mnt->mnt_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
445 	nfs_show_mount_options(m, nfss, 1);
446 
447 	seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
448 
449 	seq_printf(m, "\n\tcaps:\t");
450 	seq_printf(m, "caps=0x%x", nfss->caps);
451 	seq_printf(m, ",wtmult=%d", nfss->wtmult);
452 	seq_printf(m, ",dtsize=%d", nfss->dtsize);
453 	seq_printf(m, ",bsize=%d", nfss->bsize);
454 	seq_printf(m, ",namelen=%d", nfss->namelen);
455 
456 #ifdef CONFIG_NFS_V4
457 	if (nfss->rpc_ops->version == 4) {
458 		seq_printf(m, "\n\tnfsv4:\t");
459 		seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
460 		seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
461 		seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
462 	}
463 #endif
464 
465 	/*
466 	 * Display security flavor in effect for this mount
467 	 */
468 	seq_printf(m, "\n\tsec:\tflavor=%d", auth->au_ops->au_flavor);
469 	if (auth->au_flavor)
470 		seq_printf(m, ",pseudoflavor=%d", auth->au_flavor);
471 
472 	/*
473 	 * Display superblock I/O counters
474 	 */
475 	for_each_possible_cpu(cpu) {
476 		struct nfs_iostats *stats;
477 
478 		preempt_disable();
479 		stats = per_cpu_ptr(nfss->io_stats, cpu);
480 
481 		for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
482 			totals.events[i] += stats->events[i];
483 		for (i = 0; i < __NFSIOS_BYTESMAX; i++)
484 			totals.bytes[i] += stats->bytes[i];
485 
486 		preempt_enable();
487 	}
488 
489 	seq_printf(m, "\n\tevents:\t");
490 	for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
491 		seq_printf(m, "%lu ", totals.events[i]);
492 	seq_printf(m, "\n\tbytes:\t");
493 	for (i = 0; i < __NFSIOS_BYTESMAX; i++)
494 		seq_printf(m, "%Lu ", totals.bytes[i]);
495 	seq_printf(m, "\n");
496 
497 	rpc_print_iostats(m, nfss->client);
498 
499 	return 0;
500 }
501 
502 /*
503  * Begin unmount by attempting to remove all automounted mountpoints we added
504  * in response to traversals
505  */
506 static void nfs_umount_begin(struct vfsmount *vfsmnt, int flags)
507 {
508 	struct nfs_server *server;
509 	struct rpc_clnt	*rpc;
510 
511 	shrink_submounts(vfsmnt, &nfs_automount_list);
512 	if (!(flags & MNT_FORCE))
513 		return;
514 	/* -EIO all pending I/O */
515 	server = NFS_SB(vfsmnt->mnt_sb);
516 	rpc = server->client;
517 	if (!IS_ERR(rpc))
518 		rpc_killall_tasks(rpc);
519 	rpc = server->client_acl;
520 	if (!IS_ERR(rpc))
521 		rpc_killall_tasks(rpc);
522 }
523 
524 /*
525  * Obtain the root inode of the file system.
526  */
527 static struct inode *
528 nfs_get_root(struct super_block *sb, struct nfs_fh *rootfh, struct nfs_fsinfo *fsinfo)
529 {
530 	struct nfs_server	*server = NFS_SB(sb);
531 	int			error;
532 
533 	error = server->rpc_ops->getroot(server, rootfh, fsinfo);
534 	if (error < 0) {
535 		dprintk("nfs_get_root: getattr error = %d\n", -error);
536 		return ERR_PTR(error);
537 	}
538 
539 	server->fsid = fsinfo->fattr->fsid;
540 	return nfs_fhget(sb, rootfh, fsinfo->fattr);
541 }
542 
543 /*
544  * Do NFS version-independent mount processing, and sanity checking
545  */
546 static int
547 nfs_sb_init(struct super_block *sb, rpc_authflavor_t authflavor)
548 {
549 	struct nfs_server	*server;
550 	struct inode		*root_inode;
551 	struct nfs_fattr	fattr;
552 	struct nfs_fsinfo	fsinfo = {
553 					.fattr = &fattr,
554 				};
555 	struct nfs_pathconf pathinfo = {
556 			.fattr = &fattr,
557 	};
558 	int no_root_error = 0;
559 	unsigned long max_rpc_payload;
560 
561 	/* We probably want something more informative here */
562 	snprintf(sb->s_id, sizeof(sb->s_id), "%x:%x", MAJOR(sb->s_dev), MINOR(sb->s_dev));
563 
564 	server = NFS_SB(sb);
565 
566 	sb->s_magic      = NFS_SUPER_MAGIC;
567 
568 	server->io_stats = nfs_alloc_iostats();
569 	if (server->io_stats == NULL)
570 		return -ENOMEM;
571 
572 	root_inode = nfs_get_root(sb, &server->fh, &fsinfo);
573 	/* Did getting the root inode fail? */
574 	if (IS_ERR(root_inode)) {
575 		no_root_error = PTR_ERR(root_inode);
576 		goto out_no_root;
577 	}
578 	sb->s_root = d_alloc_root(root_inode);
579 	if (!sb->s_root) {
580 		no_root_error = -ENOMEM;
581 		goto out_no_root;
582 	}
583 	sb->s_root->d_op = server->rpc_ops->dentry_ops;
584 
585 	/* mount time stamp, in seconds */
586 	server->mount_time = jiffies;
587 
588 	/* Get some general file system info */
589 	if (server->namelen == 0 &&
590 	    server->rpc_ops->pathconf(server, &server->fh, &pathinfo) >= 0)
591 		server->namelen = pathinfo.max_namelen;
592 	/* Work out a lot of parameters */
593 	if (server->rsize == 0)
594 		server->rsize = nfs_block_size(fsinfo.rtpref, NULL);
595 	if (server->wsize == 0)
596 		server->wsize = nfs_block_size(fsinfo.wtpref, NULL);
597 
598 	if (fsinfo.rtmax >= 512 && server->rsize > fsinfo.rtmax)
599 		server->rsize = nfs_block_size(fsinfo.rtmax, NULL);
600 	if (fsinfo.wtmax >= 512 && server->wsize > fsinfo.wtmax)
601 		server->wsize = nfs_block_size(fsinfo.wtmax, NULL);
602 
603 	max_rpc_payload = nfs_block_size(rpc_max_payload(server->client), NULL);
604 	if (server->rsize > max_rpc_payload)
605 		server->rsize = max_rpc_payload;
606 	if (server->rsize > NFS_MAX_FILE_IO_SIZE)
607 		server->rsize = NFS_MAX_FILE_IO_SIZE;
608 	server->rpages = (server->rsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
609 
610 	if (server->wsize > max_rpc_payload)
611 		server->wsize = max_rpc_payload;
612 	if (server->wsize > NFS_MAX_FILE_IO_SIZE)
613 		server->wsize = NFS_MAX_FILE_IO_SIZE;
614 	server->wpages = (server->wsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
615 
616 	if (sb->s_blocksize == 0)
617 		sb->s_blocksize = nfs_block_bits(server->wsize,
618 							 &sb->s_blocksize_bits);
619 	server->wtmult = nfs_block_bits(fsinfo.wtmult, NULL);
620 
621 	server->dtsize = nfs_block_size(fsinfo.dtpref, NULL);
622 	if (server->dtsize > PAGE_CACHE_SIZE)
623 		server->dtsize = PAGE_CACHE_SIZE;
624 	if (server->dtsize > server->rsize)
625 		server->dtsize = server->rsize;
626 
627 	if (server->flags & NFS_MOUNT_NOAC) {
628 		server->acregmin = server->acregmax = 0;
629 		server->acdirmin = server->acdirmax = 0;
630 		sb->s_flags |= MS_SYNCHRONOUS;
631 	}
632 	server->backing_dev_info.ra_pages = server->rpages * NFS_MAX_READAHEAD;
633 
634 	nfs_super_set_maxbytes(sb, fsinfo.maxfilesize);
635 
636 	server->client->cl_intr = (server->flags & NFS_MOUNT_INTR) ? 1 : 0;
637 	server->client->cl_softrtry = (server->flags & NFS_MOUNT_SOFT) ? 1 : 0;
638 
639 	/* We're airborne Set socket buffersize */
640 	rpc_setbufsize(server->client, server->wsize + 100, server->rsize + 100);
641 	return 0;
642 	/* Yargs. It didn't work out. */
643 out_no_root:
644 	dprintk("nfs_sb_init: get root inode failed: errno %d\n", -no_root_error);
645 	if (!IS_ERR(root_inode))
646 		iput(root_inode);
647 	return no_root_error;
648 }
649 
650 /*
651  * Initialise the timeout values for a connection
652  */
653 static void nfs_init_timeout_values(struct rpc_timeout *to, int proto, unsigned int timeo, unsigned int retrans)
654 {
655 	to->to_initval = timeo * HZ / 10;
656 	to->to_retries = retrans;
657 	if (!to->to_retries)
658 		to->to_retries = 2;
659 
660 	switch (proto) {
661 	case IPPROTO_TCP:
662 		if (!to->to_initval)
663 			to->to_initval = 60 * HZ;
664 		if (to->to_initval > NFS_MAX_TCP_TIMEOUT)
665 			to->to_initval = NFS_MAX_TCP_TIMEOUT;
666 		to->to_increment = to->to_initval;
667 		to->to_maxval = to->to_initval + (to->to_increment * to->to_retries);
668 		to->to_exponential = 0;
669 		break;
670 	case IPPROTO_UDP:
671 	default:
672 		if (!to->to_initval)
673 			to->to_initval = 11 * HZ / 10;
674 		if (to->to_initval > NFS_MAX_UDP_TIMEOUT)
675 			to->to_initval = NFS_MAX_UDP_TIMEOUT;
676 		to->to_maxval = NFS_MAX_UDP_TIMEOUT;
677 		to->to_exponential = 1;
678 		break;
679 	}
680 }
681 
682 /*
683  * Create an RPC client handle.
684  */
685 static struct rpc_clnt *
686 nfs_create_client(struct nfs_server *server, const struct nfs_mount_data *data)
687 {
688 	struct rpc_timeout	timeparms;
689 	struct rpc_xprt		*xprt = NULL;
690 	struct rpc_clnt		*clnt = NULL;
691 	int			proto = (data->flags & NFS_MOUNT_TCP) ? IPPROTO_TCP : IPPROTO_UDP;
692 
693 	nfs_init_timeout_values(&timeparms, proto, data->timeo, data->retrans);
694 
695 	server->retrans_timeo = timeparms.to_initval;
696 	server->retrans_count = timeparms.to_retries;
697 
698 	/* create transport and client */
699 	xprt = xprt_create_proto(proto, &server->addr, &timeparms);
700 	if (IS_ERR(xprt)) {
701 		dprintk("%s: cannot create RPC transport. Error = %ld\n",
702 				__FUNCTION__, PTR_ERR(xprt));
703 		return (struct rpc_clnt *)xprt;
704 	}
705 	clnt = rpc_create_client(xprt, server->hostname, &nfs_program,
706 				 server->rpc_ops->version, data->pseudoflavor);
707 	if (IS_ERR(clnt)) {
708 		dprintk("%s: cannot create RPC client. Error = %ld\n",
709 				__FUNCTION__, PTR_ERR(xprt));
710 		goto out_fail;
711 	}
712 
713 	clnt->cl_intr     = 1;
714 	clnt->cl_softrtry = 1;
715 
716 	return clnt;
717 
718 out_fail:
719 	return clnt;
720 }
721 
722 /*
723  * Clone a server record
724  */
725 static struct nfs_server *nfs_clone_server(struct super_block *sb, struct nfs_clone_mount *data)
726 {
727 	struct nfs_server *server = NFS_SB(sb);
728 	struct nfs_server *parent = NFS_SB(data->sb);
729 	struct inode *root_inode;
730 	struct nfs_fsinfo fsinfo;
731 	void *err = ERR_PTR(-ENOMEM);
732 
733 	sb->s_op = data->sb->s_op;
734 	sb->s_blocksize = data->sb->s_blocksize;
735 	sb->s_blocksize_bits = data->sb->s_blocksize_bits;
736 	sb->s_maxbytes = data->sb->s_maxbytes;
737 
738 	server->client_sys = server->client_acl = ERR_PTR(-EINVAL);
739 	server->io_stats = nfs_alloc_iostats();
740 	if (server->io_stats == NULL)
741 		goto out;
742 
743 	server->client = rpc_clone_client(parent->client);
744 	if (IS_ERR((err = server->client)))
745 		goto out;
746 
747 	if (!IS_ERR(parent->client_sys)) {
748 		server->client_sys = rpc_clone_client(parent->client_sys);
749 		if (IS_ERR((err = server->client_sys)))
750 			goto out;
751 	}
752 	if (!IS_ERR(parent->client_acl)) {
753 		server->client_acl = rpc_clone_client(parent->client_acl);
754 		if (IS_ERR((err = server->client_acl)))
755 			goto out;
756 	}
757 	root_inode = nfs_fhget(sb, data->fh, data->fattr);
758 	if (!root_inode)
759 		goto out;
760 	sb->s_root = d_alloc_root(root_inode);
761 	if (!sb->s_root)
762 		goto out_put_root;
763 	fsinfo.fattr = data->fattr;
764 	if (NFS_PROTO(root_inode)->fsinfo(server, data->fh, &fsinfo) == 0)
765 		nfs_super_set_maxbytes(sb, fsinfo.maxfilesize);
766 	sb->s_root->d_op = server->rpc_ops->dentry_ops;
767 	sb->s_flags |= MS_ACTIVE;
768 	return server;
769 out_put_root:
770 	iput(root_inode);
771 out:
772 	return err;
773 }
774 
775 /*
776  * Copy an existing superblock and attach revised data
777  */
778 static int nfs_clone_generic_sb(struct nfs_clone_mount *data,
779 		struct super_block *(*fill_sb)(struct nfs_server *, struct nfs_clone_mount *),
780 		struct nfs_server *(*fill_server)(struct super_block *, struct nfs_clone_mount *),
781 		struct vfsmount *mnt)
782 {
783 	struct nfs_server *server;
784 	struct nfs_server *parent = NFS_SB(data->sb);
785 	struct super_block *sb = ERR_PTR(-EINVAL);
786 	char *hostname;
787 	int error = -ENOMEM;
788 	int len;
789 
790 	server = kmalloc(sizeof(struct nfs_server), GFP_KERNEL);
791 	if (server == NULL)
792 		goto out_err;
793 	memcpy(server, parent, sizeof(*server));
794 	hostname = (data->hostname != NULL) ? data->hostname : parent->hostname;
795 	len = strlen(hostname) + 1;
796 	server->hostname = kmalloc(len, GFP_KERNEL);
797 	if (server->hostname == NULL)
798 		goto free_server;
799 	memcpy(server->hostname, hostname, len);
800 	error = rpciod_up();
801 	if (error != 0)
802 		goto free_hostname;
803 
804 	sb = fill_sb(server, data);
805 	if (IS_ERR(sb)) {
806 		error = PTR_ERR(sb);
807 		goto kill_rpciod;
808 	}
809 
810 	if (sb->s_root)
811 		goto out_rpciod_down;
812 
813 	server = fill_server(sb, data);
814 	if (IS_ERR(server)) {
815 		error = PTR_ERR(server);
816 		goto out_deactivate;
817 	}
818 	return simple_set_mnt(mnt, sb);
819 out_deactivate:
820 	up_write(&sb->s_umount);
821 	deactivate_super(sb);
822 	return error;
823 out_rpciod_down:
824 	rpciod_down();
825 	kfree(server->hostname);
826 	kfree(server);
827 	return simple_set_mnt(mnt, sb);
828 kill_rpciod:
829 	rpciod_down();
830 free_hostname:
831 	kfree(server->hostname);
832 free_server:
833 	kfree(server);
834 out_err:
835 	return error;
836 }
837 
838 /*
839  * Set up an NFS2/3 superblock
840  *
841  * The way this works is that the mount process passes a structure
842  * in the data argument which contains the server's IP address
843  * and the root file handle obtained from the server's mount
844  * daemon. We stash these away in the private superblock fields.
845  */
846 static int
847 nfs_fill_super(struct super_block *sb, struct nfs_mount_data *data, int silent)
848 {
849 	struct nfs_server	*server;
850 	rpc_authflavor_t	authflavor;
851 
852 	server           = NFS_SB(sb);
853 	sb->s_blocksize_bits = 0;
854 	sb->s_blocksize = 0;
855 	if (data->bsize)
856 		sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
857 	if (data->rsize)
858 		server->rsize = nfs_block_size(data->rsize, NULL);
859 	if (data->wsize)
860 		server->wsize = nfs_block_size(data->wsize, NULL);
861 	server->flags    = data->flags & NFS_MOUNT_FLAGMASK;
862 
863 	server->acregmin = data->acregmin*HZ;
864 	server->acregmax = data->acregmax*HZ;
865 	server->acdirmin = data->acdirmin*HZ;
866 	server->acdirmax = data->acdirmax*HZ;
867 
868 	/* Start lockd here, before we might error out */
869 	if (!(server->flags & NFS_MOUNT_NONLM))
870 		lockd_up();
871 
872 	server->namelen  = data->namlen;
873 	server->hostname = kmalloc(strlen(data->hostname) + 1, GFP_KERNEL);
874 	if (!server->hostname)
875 		return -ENOMEM;
876 	strcpy(server->hostname, data->hostname);
877 
878 	/* Check NFS protocol revision and initialize RPC op vector
879 	 * and file handle pool. */
880 #ifdef CONFIG_NFS_V3
881 	if (server->flags & NFS_MOUNT_VER3) {
882 		server->rpc_ops = &nfs_v3_clientops;
883 		server->caps |= NFS_CAP_READDIRPLUS;
884 	} else {
885 		server->rpc_ops = &nfs_v2_clientops;
886 	}
887 #else
888 	server->rpc_ops = &nfs_v2_clientops;
889 #endif
890 
891 	/* Fill in pseudoflavor for mount version < 5 */
892 	if (!(data->flags & NFS_MOUNT_SECFLAVOUR))
893 		data->pseudoflavor = RPC_AUTH_UNIX;
894 	authflavor = data->pseudoflavor;	/* save for sb_init() */
895 	/* XXX maybe we want to add a server->pseudoflavor field */
896 
897 	/* Create RPC client handles */
898 	server->client = nfs_create_client(server, data);
899 	if (IS_ERR(server->client))
900 		return PTR_ERR(server->client);
901 	/* RFC 2623, sec 2.3.2 */
902 	if (authflavor != RPC_AUTH_UNIX) {
903 		struct rpc_auth *auth;
904 
905 		server->client_sys = rpc_clone_client(server->client);
906 		if (IS_ERR(server->client_sys))
907 			return PTR_ERR(server->client_sys);
908 		auth = rpcauth_create(RPC_AUTH_UNIX, server->client_sys);
909 		if (IS_ERR(auth))
910 			return PTR_ERR(auth);
911 	} else {
912 		atomic_inc(&server->client->cl_count);
913 		server->client_sys = server->client;
914 	}
915 	if (server->flags & NFS_MOUNT_VER3) {
916 #ifdef CONFIG_NFS_V3_ACL
917 		if (!(server->flags & NFS_MOUNT_NOACL)) {
918 			server->client_acl = rpc_bind_new_program(server->client, &nfsacl_program, 3);
919 			/* No errors! Assume that Sun nfsacls are supported */
920 			if (!IS_ERR(server->client_acl))
921 				server->caps |= NFS_CAP_ACLS;
922 		}
923 #else
924 		server->flags &= ~NFS_MOUNT_NOACL;
925 #endif /* CONFIG_NFS_V3_ACL */
926 		/*
927 		 * The VFS shouldn't apply the umask to mode bits. We will
928 		 * do so ourselves when necessary.
929 		 */
930 		sb->s_flags |= MS_POSIXACL;
931 		if (server->namelen == 0 || server->namelen > NFS3_MAXNAMLEN)
932 			server->namelen = NFS3_MAXNAMLEN;
933 		sb->s_time_gran = 1;
934 	} else {
935 		if (server->namelen == 0 || server->namelen > NFS2_MAXNAMLEN)
936 			server->namelen = NFS2_MAXNAMLEN;
937 	}
938 
939 	sb->s_op = &nfs_sops;
940 	return nfs_sb_init(sb, authflavor);
941 }
942 
943 static int nfs_set_super(struct super_block *s, void *data)
944 {
945 	s->s_fs_info = data;
946 	return set_anon_super(s, data);
947 }
948 
949 static int nfs_compare_super(struct super_block *sb, void *data)
950 {
951 	struct nfs_server *server = data;
952 	struct nfs_server *old = NFS_SB(sb);
953 
954 	if (old->addr.sin_addr.s_addr != server->addr.sin_addr.s_addr)
955 		return 0;
956 	if (old->addr.sin_port != server->addr.sin_port)
957 		return 0;
958 	return !nfs_compare_fh(&old->fh, &server->fh);
959 }
960 
961 static int nfs_get_sb(struct file_system_type *fs_type,
962 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
963 {
964 	int error;
965 	struct nfs_server *server = NULL;
966 	struct super_block *s;
967 	struct nfs_fh *root;
968 	struct nfs_mount_data *data = raw_data;
969 
970 	error = -EINVAL;
971 	if (data == NULL) {
972 		dprintk("%s: missing data argument\n", __FUNCTION__);
973 		goto out_err_noserver;
974 	}
975 	if (data->version <= 0 || data->version > NFS_MOUNT_VERSION) {
976 		dprintk("%s: bad mount version\n", __FUNCTION__);
977 		goto out_err_noserver;
978 	}
979 	switch (data->version) {
980 		case 1:
981 			data->namlen = 0;
982 		case 2:
983 			data->bsize  = 0;
984 		case 3:
985 			if (data->flags & NFS_MOUNT_VER3) {
986 				dprintk("%s: mount structure version %d does not support NFSv3\n",
987 						__FUNCTION__,
988 						data->version);
989 				goto out_err_noserver;
990 			}
991 			data->root.size = NFS2_FHSIZE;
992 			memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
993 		case 4:
994 			if (data->flags & NFS_MOUNT_SECFLAVOUR) {
995 				dprintk("%s: mount structure version %d does not support strong security\n",
996 						__FUNCTION__,
997 						data->version);
998 				goto out_err_noserver;
999 			}
1000 		case 5:
1001 			memset(data->context, 0, sizeof(data->context));
1002 	}
1003 #ifndef CONFIG_NFS_V3
1004 	/* If NFSv3 is not compiled in, return -EPROTONOSUPPORT */
1005 	error = -EPROTONOSUPPORT;
1006 	if (data->flags & NFS_MOUNT_VER3) {
1007 		dprintk("%s: NFSv3 not compiled into kernel\n", __FUNCTION__);
1008 		goto out_err_noserver;
1009 	}
1010 #endif /* CONFIG_NFS_V3 */
1011 
1012 	error = -ENOMEM;
1013 	server = kzalloc(sizeof(struct nfs_server), GFP_KERNEL);
1014 	if (!server)
1015 		goto out_err_noserver;
1016 	/* Zero out the NFS state stuff */
1017 	init_nfsv4_state(server);
1018 	server->client = server->client_sys = server->client_acl = ERR_PTR(-EINVAL);
1019 
1020 	root = &server->fh;
1021 	if (data->flags & NFS_MOUNT_VER3)
1022 		root->size = data->root.size;
1023 	else
1024 		root->size = NFS2_FHSIZE;
1025 	error = -EINVAL;
1026 	if (root->size > sizeof(root->data)) {
1027 		dprintk("%s: invalid root filehandle\n", __FUNCTION__);
1028 		goto out_err;
1029 	}
1030 	memcpy(root->data, data->root.data, root->size);
1031 
1032 	/* We now require that the mount process passes the remote address */
1033 	memcpy(&server->addr, &data->addr, sizeof(server->addr));
1034 	if (server->addr.sin_addr.s_addr == INADDR_ANY) {
1035 		dprintk("%s: mount program didn't pass remote address!\n",
1036 				__FUNCTION__);
1037 		goto out_err;
1038 	}
1039 
1040 	/* Fire up rpciod if not yet running */
1041 	error = rpciod_up();
1042 	if (error < 0) {
1043 		dprintk("%s: couldn't start rpciod! Error = %d\n",
1044 				__FUNCTION__, error);
1045 		goto out_err;
1046 	}
1047 
1048 	s = sget(fs_type, nfs_compare_super, nfs_set_super, server);
1049 	if (IS_ERR(s)) {
1050 		error = PTR_ERR(s);
1051 		goto out_err_rpciod;
1052 	}
1053 
1054 	if (s->s_root)
1055 		goto out_rpciod_down;
1056 
1057 	s->s_flags = flags;
1058 
1059 	error = nfs_fill_super(s, data, flags & MS_SILENT ? 1 : 0);
1060 	if (error) {
1061 		up_write(&s->s_umount);
1062 		deactivate_super(s);
1063 		return error;
1064 	}
1065 	s->s_flags |= MS_ACTIVE;
1066 	return simple_set_mnt(mnt, s);
1067 
1068 out_rpciod_down:
1069 	rpciod_down();
1070 	kfree(server);
1071 	return simple_set_mnt(mnt, s);
1072 
1073 out_err_rpciod:
1074 	rpciod_down();
1075 out_err:
1076 	kfree(server);
1077 out_err_noserver:
1078 	return error;
1079 }
1080 
1081 static void nfs_kill_super(struct super_block *s)
1082 {
1083 	struct nfs_server *server = NFS_SB(s);
1084 
1085 	kill_anon_super(s);
1086 
1087 	if (!IS_ERR(server->client))
1088 		rpc_shutdown_client(server->client);
1089 	if (!IS_ERR(server->client_sys))
1090 		rpc_shutdown_client(server->client_sys);
1091 	if (!IS_ERR(server->client_acl))
1092 		rpc_shutdown_client(server->client_acl);
1093 
1094 	if (!(server->flags & NFS_MOUNT_NONLM))
1095 		lockd_down();	/* release rpc.lockd */
1096 
1097 	rpciod_down();		/* release rpciod */
1098 
1099 	nfs_free_iostats(server->io_stats);
1100 	kfree(server->hostname);
1101 	kfree(server);
1102 	nfs_release_automount_timer();
1103 }
1104 
1105 static struct super_block *nfs_clone_sb(struct nfs_server *server, struct nfs_clone_mount *data)
1106 {
1107 	struct super_block *sb;
1108 
1109 	server->fsid = data->fattr->fsid;
1110 	nfs_copy_fh(&server->fh, data->fh);
1111 	sb = sget(&nfs_fs_type, nfs_compare_super, nfs_set_super, server);
1112 	if (!IS_ERR(sb) && sb->s_root == NULL && !(server->flags & NFS_MOUNT_NONLM))
1113 		lockd_up();
1114 	return sb;
1115 }
1116 
1117 static int nfs_clone_nfs_sb(struct file_system_type *fs_type,
1118 		int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
1119 {
1120 	struct nfs_clone_mount *data = raw_data;
1121 	return nfs_clone_generic_sb(data, nfs_clone_sb, nfs_clone_server, mnt);
1122 }
1123 
1124 #ifdef CONFIG_NFS_V4
1125 static struct rpc_clnt *nfs4_create_client(struct nfs_server *server,
1126 	struct rpc_timeout *timeparms, int proto, rpc_authflavor_t flavor)
1127 {
1128 	struct nfs4_client *clp;
1129 	struct rpc_xprt *xprt = NULL;
1130 	struct rpc_clnt *clnt = NULL;
1131 	int err = -EIO;
1132 
1133 	clp = nfs4_get_client(&server->addr.sin_addr);
1134 	if (!clp) {
1135 		dprintk("%s: failed to create NFS4 client.\n", __FUNCTION__);
1136 		return ERR_PTR(err);
1137 	}
1138 
1139 	/* Now create transport and client */
1140 	down_write(&clp->cl_sem);
1141 	if (IS_ERR(clp->cl_rpcclient)) {
1142 		xprt = xprt_create_proto(proto, &server->addr, timeparms);
1143 		if (IS_ERR(xprt)) {
1144 			up_write(&clp->cl_sem);
1145 			err = PTR_ERR(xprt);
1146 			dprintk("%s: cannot create RPC transport. Error = %d\n",
1147 					__FUNCTION__, err);
1148 			goto out_fail;
1149 		}
1150 		/* Bind to a reserved port! */
1151 		xprt->resvport = 1;
1152 		clnt = rpc_create_client(xprt, server->hostname, &nfs_program,
1153 				server->rpc_ops->version, flavor);
1154 		if (IS_ERR(clnt)) {
1155 			up_write(&clp->cl_sem);
1156 			err = PTR_ERR(clnt);
1157 			dprintk("%s: cannot create RPC client. Error = %d\n",
1158 					__FUNCTION__, err);
1159 			goto out_fail;
1160 		}
1161 		clnt->cl_intr     = 1;
1162 		clnt->cl_softrtry = 1;
1163 		clp->cl_rpcclient = clnt;
1164 		memcpy(clp->cl_ipaddr, server->ip_addr, sizeof(clp->cl_ipaddr));
1165 		nfs_idmap_new(clp);
1166 	}
1167 	list_add_tail(&server->nfs4_siblings, &clp->cl_superblocks);
1168 	clnt = rpc_clone_client(clp->cl_rpcclient);
1169 	if (!IS_ERR(clnt))
1170 		server->nfs4_state = clp;
1171 	up_write(&clp->cl_sem);
1172 	clp = NULL;
1173 
1174 	if (IS_ERR(clnt)) {
1175 		dprintk("%s: cannot create RPC client. Error = %d\n",
1176 				__FUNCTION__, err);
1177 		return clnt;
1178 	}
1179 
1180 	if (server->nfs4_state->cl_idmap == NULL) {
1181 		dprintk("%s: failed to create idmapper.\n", __FUNCTION__);
1182 		return ERR_PTR(-ENOMEM);
1183 	}
1184 
1185 	if (clnt->cl_auth->au_flavor != flavor) {
1186 		struct rpc_auth *auth;
1187 
1188 		auth = rpcauth_create(flavor, clnt);
1189 		if (IS_ERR(auth)) {
1190 			dprintk("%s: couldn't create credcache!\n", __FUNCTION__);
1191 			return (struct rpc_clnt *)auth;
1192 		}
1193 	}
1194 	return clnt;
1195 
1196  out_fail:
1197 	if (clp)
1198 		nfs4_put_client(clp);
1199 	return ERR_PTR(err);
1200 }
1201 
1202 /*
1203  * Set up an NFS4 superblock
1204  */
1205 static int nfs4_fill_super(struct super_block *sb, struct nfs4_mount_data *data, int silent)
1206 {
1207 	struct nfs_server *server;
1208 	struct rpc_timeout timeparms;
1209 	rpc_authflavor_t authflavour;
1210 	int err = -EIO;
1211 
1212 	sb->s_blocksize_bits = 0;
1213 	sb->s_blocksize = 0;
1214 	server = NFS_SB(sb);
1215 	if (data->rsize != 0)
1216 		server->rsize = nfs_block_size(data->rsize, NULL);
1217 	if (data->wsize != 0)
1218 		server->wsize = nfs_block_size(data->wsize, NULL);
1219 	server->flags = data->flags & NFS_MOUNT_FLAGMASK;
1220 	server->caps = NFS_CAP_ATOMIC_OPEN;
1221 
1222 	server->acregmin = data->acregmin*HZ;
1223 	server->acregmax = data->acregmax*HZ;
1224 	server->acdirmin = data->acdirmin*HZ;
1225 	server->acdirmax = data->acdirmax*HZ;
1226 
1227 	server->rpc_ops = &nfs_v4_clientops;
1228 
1229 	nfs_init_timeout_values(&timeparms, data->proto, data->timeo, data->retrans);
1230 
1231 	server->retrans_timeo = timeparms.to_initval;
1232 	server->retrans_count = timeparms.to_retries;
1233 
1234 	/* Now create transport and client */
1235 	authflavour = RPC_AUTH_UNIX;
1236 	if (data->auth_flavourlen != 0) {
1237 		if (data->auth_flavourlen != 1) {
1238 			dprintk("%s: Invalid number of RPC auth flavours %d.\n",
1239 					__FUNCTION__, data->auth_flavourlen);
1240 			err = -EINVAL;
1241 			goto out_fail;
1242 		}
1243 		if (copy_from_user(&authflavour, data->auth_flavours, sizeof(authflavour))) {
1244 			err = -EFAULT;
1245 			goto out_fail;
1246 		}
1247 	}
1248 
1249 	server->client = nfs4_create_client(server, &timeparms, data->proto, authflavour);
1250 	if (IS_ERR(server->client)) {
1251 		err = PTR_ERR(server->client);
1252 			dprintk("%s: cannot create RPC client. Error = %d\n",
1253 					__FUNCTION__, err);
1254 			goto out_fail;
1255 	}
1256 
1257 	sb->s_time_gran = 1;
1258 
1259 	sb->s_op = &nfs4_sops;
1260 	err = nfs_sb_init(sb, authflavour);
1261 
1262  out_fail:
1263 	return err;
1264 }
1265 
1266 static int nfs4_compare_super(struct super_block *sb, void *data)
1267 {
1268 	struct nfs_server *server = data;
1269 	struct nfs_server *old = NFS_SB(sb);
1270 
1271 	if (strcmp(server->hostname, old->hostname) != 0)
1272 		return 0;
1273 	if (strcmp(server->mnt_path, old->mnt_path) != 0)
1274 		return 0;
1275 	return 1;
1276 }
1277 
1278 static void *
1279 nfs_copy_user_string(char *dst, struct nfs_string *src, int maxlen)
1280 {
1281 	void *p = NULL;
1282 
1283 	if (!src->len)
1284 		return ERR_PTR(-EINVAL);
1285 	if (src->len < maxlen)
1286 		maxlen = src->len;
1287 	if (dst == NULL) {
1288 		p = dst = kmalloc(maxlen + 1, GFP_KERNEL);
1289 		if (p == NULL)
1290 			return ERR_PTR(-ENOMEM);
1291 	}
1292 	if (copy_from_user(dst, src->data, maxlen)) {
1293 		kfree(p);
1294 		return ERR_PTR(-EFAULT);
1295 	}
1296 	dst[maxlen] = '\0';
1297 	return dst;
1298 }
1299 
1300 static int nfs4_get_sb(struct file_system_type *fs_type,
1301 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
1302 {
1303 	int error;
1304 	struct nfs_server *server;
1305 	struct super_block *s;
1306 	struct nfs4_mount_data *data = raw_data;
1307 	void *p;
1308 
1309 	if (data == NULL) {
1310 		dprintk("%s: missing data argument\n", __FUNCTION__);
1311 		return -EINVAL;
1312 	}
1313 	if (data->version <= 0 || data->version > NFS4_MOUNT_VERSION) {
1314 		dprintk("%s: bad mount version\n", __FUNCTION__);
1315 		return -EINVAL;
1316 	}
1317 
1318 	server = kzalloc(sizeof(struct nfs_server), GFP_KERNEL);
1319 	if (!server)
1320 		return -ENOMEM;
1321 	/* Zero out the NFS state stuff */
1322 	init_nfsv4_state(server);
1323 	server->client = server->client_sys = server->client_acl = ERR_PTR(-EINVAL);
1324 
1325 	p = nfs_copy_user_string(NULL, &data->hostname, 256);
1326 	if (IS_ERR(p))
1327 		goto out_err;
1328 	server->hostname = p;
1329 
1330 	p = nfs_copy_user_string(NULL, &data->mnt_path, 1024);
1331 	if (IS_ERR(p))
1332 		goto out_err;
1333 	server->mnt_path = p;
1334 
1335 	p = nfs_copy_user_string(server->ip_addr, &data->client_addr,
1336 			sizeof(server->ip_addr) - 1);
1337 	if (IS_ERR(p))
1338 		goto out_err;
1339 
1340 	/* We now require that the mount process passes the remote address */
1341 	if (data->host_addrlen != sizeof(server->addr)) {
1342 		error = -EINVAL;
1343 		goto out_free;
1344 	}
1345 	if (copy_from_user(&server->addr, data->host_addr, sizeof(server->addr))) {
1346 		error = -EFAULT;
1347 		goto out_free;
1348 	}
1349 	if (server->addr.sin_family != AF_INET ||
1350 	    server->addr.sin_addr.s_addr == INADDR_ANY) {
1351 		dprintk("%s: mount program didn't pass remote IP address!\n",
1352 				__FUNCTION__);
1353 		error = -EINVAL;
1354 		goto out_free;
1355 	}
1356 
1357 	/* Fire up rpciod if not yet running */
1358 	error = rpciod_up();
1359 	if (error < 0) {
1360 		dprintk("%s: couldn't start rpciod! Error = %d\n",
1361 				__FUNCTION__, error);
1362 		goto out_free;
1363 	}
1364 
1365 	s = sget(fs_type, nfs4_compare_super, nfs_set_super, server);
1366 
1367 	if (IS_ERR(s)) {
1368 		error = PTR_ERR(s);
1369 		goto out_free;
1370 	}
1371 
1372 	if (s->s_root) {
1373 		kfree(server->mnt_path);
1374 		kfree(server->hostname);
1375 		kfree(server);
1376 		return simple_set_mnt(mnt, s);
1377 	}
1378 
1379 	s->s_flags = flags;
1380 
1381 	error = nfs4_fill_super(s, data, flags & MS_SILENT ? 1 : 0);
1382 	if (error) {
1383 		up_write(&s->s_umount);
1384 		deactivate_super(s);
1385 		return error;
1386 	}
1387 	s->s_flags |= MS_ACTIVE;
1388 	return simple_set_mnt(mnt, s);
1389 out_err:
1390 	error = PTR_ERR(p);
1391 out_free:
1392 	kfree(server->mnt_path);
1393 	kfree(server->hostname);
1394 	kfree(server);
1395 	return error;
1396 }
1397 
1398 static void nfs4_kill_super(struct super_block *sb)
1399 {
1400 	struct nfs_server *server = NFS_SB(sb);
1401 
1402 	nfs_return_all_delegations(sb);
1403 	kill_anon_super(sb);
1404 
1405 	nfs4_renewd_prepare_shutdown(server);
1406 
1407 	if (server->client != NULL && !IS_ERR(server->client))
1408 		rpc_shutdown_client(server->client);
1409 
1410 	destroy_nfsv4_state(server);
1411 
1412 	rpciod_down();
1413 
1414 	nfs_free_iostats(server->io_stats);
1415 	kfree(server->hostname);
1416 	kfree(server);
1417 	nfs_release_automount_timer();
1418 }
1419 
1420 /*
1421  * Constructs the SERVER-side path
1422  */
1423 static inline char *nfs4_dup_path(const struct dentry *dentry)
1424 {
1425 	char *page = (char *) __get_free_page(GFP_USER);
1426 	char *path;
1427 
1428 	path = nfs4_path(dentry, page, PAGE_SIZE);
1429 	if (!IS_ERR(path)) {
1430 		int len = PAGE_SIZE + page - path;
1431 		char *tmp = path;
1432 
1433 		path = kmalloc(len, GFP_KERNEL);
1434 		if (path)
1435 			memcpy(path, tmp, len);
1436 		else
1437 			path = ERR_PTR(-ENOMEM);
1438 	}
1439 	free_page((unsigned long)page);
1440 	return path;
1441 }
1442 
1443 static struct super_block *nfs4_clone_sb(struct nfs_server *server, struct nfs_clone_mount *data)
1444 {
1445 	const struct dentry *dentry = data->dentry;
1446 	struct nfs4_client *clp = server->nfs4_state;
1447 	struct super_block *sb;
1448 
1449 	server->fsid = data->fattr->fsid;
1450 	nfs_copy_fh(&server->fh, data->fh);
1451 	server->mnt_path = nfs4_dup_path(dentry);
1452 	if (IS_ERR(server->mnt_path)) {
1453 		sb = (struct super_block *)server->mnt_path;
1454 		goto err;
1455 	}
1456 	sb = sget(&nfs4_fs_type, nfs4_compare_super, nfs_set_super, server);
1457 	if (IS_ERR(sb) || sb->s_root)
1458 		goto free_path;
1459 	nfs4_server_capabilities(server, &server->fh);
1460 
1461 	down_write(&clp->cl_sem);
1462 	atomic_inc(&clp->cl_count);
1463 	list_add_tail(&server->nfs4_siblings, &clp->cl_superblocks);
1464 	up_write(&clp->cl_sem);
1465 	return sb;
1466 free_path:
1467 	kfree(server->mnt_path);
1468 err:
1469 	server->mnt_path = NULL;
1470 	return sb;
1471 }
1472 
1473 static int nfs_clone_nfs4_sb(struct file_system_type *fs_type,
1474 		int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
1475 {
1476 	struct nfs_clone_mount *data = raw_data;
1477 	return nfs_clone_generic_sb(data, nfs4_clone_sb, nfs_clone_server, mnt);
1478 }
1479 
1480 static struct super_block *nfs4_referral_sb(struct nfs_server *server, struct nfs_clone_mount *data)
1481 {
1482 	struct super_block *sb = ERR_PTR(-ENOMEM);
1483 	int len;
1484 
1485 	len = strlen(data->mnt_path) + 1;
1486 	server->mnt_path = kmalloc(len, GFP_KERNEL);
1487 	if (server->mnt_path == NULL)
1488 		goto err;
1489 	memcpy(server->mnt_path, data->mnt_path, len);
1490 	memcpy(&server->addr, data->addr, sizeof(struct sockaddr_in));
1491 
1492 	sb = sget(&nfs4_fs_type, nfs4_compare_super, nfs_set_super, server);
1493 	if (IS_ERR(sb) || sb->s_root)
1494 		goto free_path;
1495 	return sb;
1496 free_path:
1497 	kfree(server->mnt_path);
1498 err:
1499 	server->mnt_path = NULL;
1500 	return sb;
1501 }
1502 
1503 static struct nfs_server *nfs4_referral_server(struct super_block *sb, struct nfs_clone_mount *data)
1504 {
1505 	struct nfs_server *server = NFS_SB(sb);
1506 	struct rpc_timeout timeparms;
1507 	int proto, timeo, retrans;
1508 	void *err;
1509 
1510 	proto = IPPROTO_TCP;
1511 	/* Since we are following a referral and there may be alternatives,
1512 	   set the timeouts and retries to low values */
1513 	timeo = 2;
1514 	retrans = 1;
1515 	nfs_init_timeout_values(&timeparms, proto, timeo, retrans);
1516 
1517 	server->client = nfs4_create_client(server, &timeparms, proto, data->authflavor);
1518 	if (IS_ERR((err = server->client)))
1519 		goto out_err;
1520 
1521 	sb->s_time_gran = 1;
1522 	sb->s_op = &nfs4_sops;
1523 	err = ERR_PTR(nfs_sb_init(sb, data->authflavor));
1524 	if (!IS_ERR(err))
1525 		return server;
1526 out_err:
1527 	return (struct nfs_server *)err;
1528 }
1529 
1530 static int nfs_referral_nfs4_sb(struct file_system_type *fs_type,
1531 		int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
1532 {
1533 	struct nfs_clone_mount *data = raw_data;
1534 	return nfs_clone_generic_sb(data, nfs4_referral_sb, nfs4_referral_server, mnt);
1535 }
1536 
1537 #endif
1538