xref: /titanic_41/usr/src/uts/common/nfs/nfs_clnt.h (revision ba2e4443695ee6a6f420a35cd4fc3d3346d22932)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T	*/
28 /*	  All Rights Reserved  	*/
29 
30 #ifndef	_NFS_NFS_CLNT_H
31 #define	_NFS_NFS_CLNT_H
32 
33 #pragma ident	"%Z%%M%	%I%	%E% SMI"
34 
35 #include <sys/utsname.h>
36 #include <sys/kstat.h>
37 #include <sys/time.h>
38 #include <vm/page.h>
39 #include <sys/thread.h>
40 #include <nfs/rnode.h>
41 #include <sys/list.h>
42 
43 #ifdef	__cplusplus
44 extern "C" {
45 #endif
46 
47 #define	HOSTNAMESZ	32
48 #define	ACREGMIN	3	/* min secs to hold cached file attr */
49 #define	ACREGMAX	60	/* max secs to hold cached file attr */
50 #define	ACDIRMIN	30	/* min secs to hold cached dir attr */
51 #define	ACDIRMAX	60	/* max secs to hold cached dir attr */
52 #define	ACMINMAX	3600	/* 1 hr is longest min timeout */
53 #define	ACMAXMAX	36000	/* 10 hr is longest max timeout */
54 
55 #define	NFS_CALLTYPES	3	/* Lookups, Reads, Writes */
56 
57 /*
58  * rfscall() flags
59  */
60 #define	RFSCALL_SOFT	0x00000001	/* Do op as if fs was soft-mounted */
61 
62 /*
63  * Fake errno passed back from rfscall to indicate transfer size adjustment
64  */
65 #define	ENFS_TRYAGAIN	999
66 
67 /*
68  * The NFS specific async_reqs structure.
69  */
70 
71 enum iotype {
72 	NFS_READ_AHEAD,
73 	NFS_PUTAPAGE,
74 	NFS_PAGEIO,
75 	NFS_READDIR,
76 	NFS_COMMIT,
77 	NFS_INACTIVE
78 };
79 #define	NFS_ASYNC_TYPES	(NFS_INACTIVE + 1)
80 
81 struct nfs_async_read_req {
82 	void (*readahead)();		/* pointer to readahead function */
83 	u_offset_t blkoff;		/* offset in file */
84 	struct seg *seg;		/* segment to do i/o to */
85 	caddr_t addr;			/* address to do i/o to */
86 };
87 
88 struct nfs_pageio_req {
89 	int (*pageio)();		/* pointer to pageio function */
90 	page_t *pp;			/* page list */
91 	u_offset_t io_off;		/* offset in file */
92 	uint_t io_len;			/* size of request */
93 	int flags;
94 };
95 
96 struct nfs_readdir_req {
97 	int (*readdir)();		/* pointer to readdir function */
98 	struct rddir_cache *rdc;	/* pointer to cache entry to fill */
99 };
100 
101 struct nfs_commit_req {
102 	void (*commit)();		/* pointer to commit function */
103 	page_t *plist;			/* page list */
104 	offset3 offset;			/* starting offset */
105 	count3 count;			/* size of range to be commited */
106 };
107 
108 struct nfs_inactive_req {
109 	void (*inactive)();		/* pointer to inactive function */
110 };
111 
112 struct nfs_async_reqs {
113 	struct nfs_async_reqs *a_next;	/* pointer to next arg struct */
114 #ifdef DEBUG
115 	kthread_t *a_queuer;		/* thread id of queueing thread */
116 #endif
117 	struct vnode *a_vp;		/* vnode pointer */
118 	struct cred *a_cred;		/* cred pointer */
119 	enum iotype a_io;		/* i/o type */
120 	union {
121 		struct nfs_async_read_req a_read_args;
122 		struct nfs_pageio_req a_pageio_args;
123 		struct nfs_readdir_req a_readdir_args;
124 		struct nfs_commit_req a_commit_args;
125 		struct nfs_inactive_req a_inactive_args;
126 	} a_args;
127 };
128 
129 #define	a_nfs_readahead a_args.a_read_args.readahead
130 #define	a_nfs_blkoff a_args.a_read_args.blkoff
131 #define	a_nfs_seg a_args.a_read_args.seg
132 #define	a_nfs_addr a_args.a_read_args.addr
133 
134 #define	a_nfs_putapage a_args.a_pageio_args.pageio
135 #define	a_nfs_pageio a_args.a_pageio_args.pageio
136 #define	a_nfs_pp a_args.a_pageio_args.pp
137 #define	a_nfs_off a_args.a_pageio_args.io_off
138 #define	a_nfs_len a_args.a_pageio_args.io_len
139 #define	a_nfs_flags a_args.a_pageio_args.flags
140 
141 #define	a_nfs_readdir a_args.a_readdir_args.readdir
142 #define	a_nfs_rdc a_args.a_readdir_args.rdc
143 
144 #define	a_nfs_commit a_args.a_commit_args.commit
145 #define	a_nfs_plist a_args.a_commit_args.plist
146 #define	a_nfs_offset a_args.a_commit_args.offset
147 #define	a_nfs_count a_args.a_commit_args.count
148 
149 #define	a_nfs_inactive a_args.a_inactive_args.inactive
150 
151 /*
152  * Due to the way the address space callbacks are used to execute a delmap,
153  * we must keep track of how many times the same thread has called
154  * VOP_DELMAP()->nfs_delmap()/nfs3_delmap().  This is done by having a list of
155  * nfs_delmapcall_t's associated with each rnode_t.  This list is protected
156  * by the rnode_t's r_statelock.  The individual elements do not need to be
157  * protected as they will only ever be created, modified and destroyed by
158  * one thread (the call_id).
159  * See nfs_delmap()/nfs3_delmap() for further explanation.
160  */
161 typedef struct nfs_delmapcall {
162 	kthread_t	*call_id;
163 	int		error;	/* error from delmap */
164 	list_node_t	call_node;
165 } nfs_delmapcall_t;
166 
167 /*
168  * delmap address space callback args
169  */
170 typedef struct nfs_delmap_args {
171 	vnode_t			*vp;
172 	offset_t		off;
173 	caddr_t			addr;
174 	size_t			len;
175 	uint_t			prot;
176 	uint_t			maxprot;
177 	uint_t			flags;
178 	cred_t			*cr;
179 	nfs_delmapcall_t	*caller; /* to retrieve errors from the cb */
180 } nfs_delmap_args_t;
181 
182 #ifdef _KERNEL
183 extern nfs_delmapcall_t	*nfs_init_delmapcall(void);
184 extern void	nfs_free_delmapcall(nfs_delmapcall_t *);
185 extern int	nfs_find_and_delete_delmapcall(rnode_t *, int *errp);
186 #endif /* _KERNEL */
187 
188 /*
189  * The following structures, chhead and chtab,  make up the client handle
190  * cache.  chhead represents a quadruple(RPC program, RPC version, Protocol
191  * Family, and Transport).  For example, a chhead entry could represent
192  * NFS/V3/IPv4/TCP requests.  chhead nodes are linked together as a singly
193  * linked list and is referenced from chtable.
194  *
195  * chtab represents an allocated client handle bound to a particular
196  * quadruple. These nodes chain down from a chhead node.  chtab
197  * entries which are on the chain are considered free, so a thread may simply
198  * unlink the first node without traversing the chain.  When the thread is
199  * completed with its request, it puts the chtab node back on the chain.
200  */
201 typedef struct chhead {
202 	struct chhead *ch_next;	/* next quadruple */
203 	struct chtab *ch_list;	/* pointer to free client handle(s) */
204 	uint64_t ch_timesused;	/* times this quadruple was requested */
205 	rpcprog_t ch_prog;	/* RPC program number */
206 	rpcvers_t ch_vers;	/* RPC version number */
207 	dev_t ch_dev;		/* pseudo device number (i.e. /dev/udp) */
208 	char *ch_protofmly;	/* protocol (i.e. NC_INET, NC_LOOPBACK) */
209 } chhead_t;
210 
211 typedef struct chtab {
212 	struct chtab *ch_list;	/* next free client handle */
213 	struct chhead *ch_head;	/* associated quadruple */
214 	time_t ch_freed;	/* timestamp when freed */
215 	CLIENT *ch_client;	/* pointer to client handle */
216 } chtab_t;
217 
218 /*
219  * clinfo is a structure which encapsulates data that is needed to
220  * obtain a client handle from the cache
221  */
222 typedef struct clinfo {
223 	rpcprog_t cl_prog;	/* RPC program number */
224 	rpcvers_t cl_vers;	/* RPC version number */
225 	uint_t cl_readsize;	/* transfer size */
226 	int cl_retrans;		/* times to retry request */
227 	uint_t cl_flags;	/* info flags */
228 } clinfo_t;
229 
230 /*
231  * Failover information, passed opaquely through rfscall()
232  */
233 typedef struct failinfo {
234 	struct vnode	*vp;
235 	caddr_t		fhp;
236 	void (*copyproc)(caddr_t, vnode_t *);
237 	int (*lookupproc)(vnode_t *, char *, vnode_t **, struct pathname *,
238 			int, vnode_t *, struct cred *, int);
239 	int (*xattrdirproc)(vnode_t *, vnode_t **, bool_t, cred_t *, int);
240 } failinfo_t;
241 
242 /*
243  * Static server information
244  *
245  * These fields are protected by sv_lock:
246  *	sv_flags
247  */
248 typedef struct servinfo {
249 	struct knetconfig *sv_knconf;   /* bound TLI fd */
250 	struct knetconfig *sv_origknconf;	/* For RDMA save orig knconf */
251 	struct netbuf	sv_addr;	/* server's address */
252 	nfs_fhandle	sv_fhandle;	/* this server's filehandle */
253 	struct sec_data *sv_secdata;	/* security data for rpcsec module */
254 	char	*sv_hostname;		/* server's hostname */
255 	int	sv_hostnamelen;		/* server's hostname length */
256 	uint_t	sv_flags;		/* see below */
257 	struct servinfo	*sv_next;	/* next in list */
258 	kmutex_t sv_lock;
259 } servinfo_t;
260 
261 /*
262  * The values for sv_flags.
263  */
264 #define	SV_ROOT_STALE	0x1		/* root vnode got ESTALE */
265 
266 /*
267  * Switch from RDMA knconf to original mount knconf
268  */
269 
270 #define	ORIG_KNCONF(mi) (mi->mi_curr_serv->sv_origknconf ? \
271 	mi->mi_curr_serv->sv_origknconf : mi->mi_curr_serv->sv_knconf)
272 
273 /*
274  * NFS private data per mounted file system
275  *	The mi_lock mutex protects the following fields:
276  *		mi_flags
277  *		mi_printed
278  *		mi_down
279  *		mi_tsize
280  *		mi_stsize
281  *		mi_curread
282  *		mi_curwrite
283  *		mi_timers
284  *		mi_curr_serv
285  *		mi_readers
286  *		mi_klmconfig
287  *
288  *	The mi_async_lock mutex protects the following fields:
289  *		mi_async_reqs
290  *		mi_async_req_count
291  *		mi_async_tail
292  *		mi_async_curr
293  *		mi_async_clusters
294  *		mi_async_init_clusters
295  *		mi_threads
296  *		mi_manager_thread
297  *
298  *	Normally the netconfig information for the mount comes from
299  *	mi_curr_serv and mi_klmconfig is NULL.  If NLM calls need to use a
300  *	different transport, mi_klmconfig contains the necessary netconfig
301  *	information.
302  *
303  *	'mi_zone' is initialized at structure creation time, and never
304  *	changes; it may be read without a lock.
305  *
306  *	mi_zone_node is linkage into the mi4_globals.mig_list, and is
307  *	protected by mi4_globals.mig_list_lock.
308  *
309  *	Locking order:
310  *	  mi_globals::mig_lock > mi_async_lock > mi_lock
311  */
312 typedef struct mntinfo {
313 	kmutex_t	mi_lock;	/* protects mntinfo fields */
314 	struct servinfo *mi_servers;    /* server list */
315 	struct servinfo *mi_curr_serv;  /* current server */
316 	kcondvar_t	mi_failover_cv;	/* failover synchronization */
317 	int		mi_readers;	/* failover - users of mi_curr_serv */
318 	struct vfs	*mi_vfsp;	/* back pointer to vfs */
319 	enum vtype	mi_type;	/* file type of the root vnode */
320 	uint_t		mi_flags;	/* see below */
321 	uint_t		mi_tsize;	/* max read transfer size (bytes) */
322 	uint_t		mi_stsize;	/* max write transfer size (bytes) */
323 	int		mi_timeo;	/* inital timeout in 10th sec */
324 	int		mi_retrans;	/* times to retry request */
325 	hrtime_t	mi_acregmin;	/* min time to hold cached file attr */
326 	hrtime_t	mi_acregmax;	/* max time to hold cached file attr */
327 	hrtime_t	mi_acdirmin;	/* min time to hold cached dir attr */
328 	hrtime_t	mi_acdirmax;	/* max time to hold cached dir attr */
329 	len_t		mi_maxfilesize; /* for pathconf _PC_FILESIZEBITS */
330 	/*
331 	 * Extra fields for congestion control, one per NFS call type,
332 	 * plus one global one.
333 	 */
334 	struct rpc_timers mi_timers[NFS_CALLTYPES+1];
335 	int		mi_curread;	/* current read size */
336 	int		mi_curwrite;	/* current write size */
337 	/*
338 	 * async I/O management
339 	 */
340 	struct nfs_async_reqs *mi_async_reqs[NFS_ASYNC_TYPES];
341 	struct nfs_async_reqs *mi_async_tail[NFS_ASYNC_TYPES];
342 	struct nfs_async_reqs **mi_async_curr;	/* current async queue */
343 	uint_t		mi_async_clusters[NFS_ASYNC_TYPES];
344 	uint_t		mi_async_init_clusters;
345 	uint_t		mi_async_req_count; /* # outstanding work requests */
346 	kcondvar_t	mi_async_reqs_cv; /* signaled when there's work */
347 	ushort_t	mi_threads;	/* number of active async threads */
348 	ushort_t	mi_max_threads;	/* max number of async worker threads */
349 	kthread_t	*mi_manager_thread;  /* async manager thread */
350 	kcondvar_t	mi_async_cv; /* signaled when the last worker dies */
351 	kcondvar_t	mi_async_work_cv; /* tell workers to work */
352 	kmutex_t	mi_async_lock;	/* lock to protect async list */
353 	/*
354 	 * Other stuff
355 	 */
356 	struct pathcnf *mi_pathconf;	/* static pathconf kludge */
357 	rpcprog_t	mi_prog;	/* RPC program number */
358 	rpcvers_t	mi_vers;	/* RPC program version number */
359 	char		**mi_rfsnames;	/* mapping to proc names */
360 	kstat_named_t	*mi_reqs;	/* count of requests */
361 	uchar_t		*mi_call_type;	/* dynamic retrans call types */
362 	uchar_t		*mi_ss_call_type;	/* semisoft call type */
363 	uchar_t		*mi_timer_type;	/* dynamic retrans timer types */
364 	clock_t		mi_printftime;	/* last error printf time */
365 	/*
366 	 * ACL entries
367 	 */
368 	char		**mi_aclnames;	/* mapping to proc names */
369 	kstat_named_t	*mi_aclreqs;	/* count of acl requests */
370 	uchar_t		*mi_acl_call_type; /* dynamic retrans call types */
371 	uchar_t		*mi_acl_ss_call_type; /* semisoft call types */
372 	uchar_t		*mi_acl_timer_type; /* dynamic retrans timer types */
373 	/*
374 	 * Client Side Failover stats
375 	 */
376 	uint_t		mi_noresponse;	/* server not responding count */
377 	uint_t		mi_failover; 	/* failover to new server count */
378 	uint_t		mi_remap;	/* remap to new server count */
379 	/*
380 	 * Kstat statistics
381 	 */
382 	struct kstat	*mi_io_kstats;
383 	struct kstat	*mi_ro_kstats;
384 	struct knetconfig *mi_klmconfig;
385 	/*
386 	 * Zones support.
387 	 */
388 	struct zone	*mi_zone;	/* Zone mounted in */
389 	list_node_t	mi_zone_node;	/* Linkage into per-zone mi list */
390 	/*
391 	 * Serializes threads in failover_remap.
392 	 * Need to acquire this lock first in failover_remap() function
393 	 * before acquiring any other rnode lock.
394 	 */
395 	kmutex_t	mi_remap_lock;
396 } mntinfo_t;
397 
398 /*
399  * vfs pointer to mount info
400  */
401 #define	VFTOMI(vfsp)	((mntinfo_t *)((vfsp)->vfs_data))
402 
403 /*
404  * vnode pointer to mount info
405  */
406 #define	VTOMI(vp)	((mntinfo_t *)(((vp)->v_vfsp)->vfs_data))
407 
408 /*
409  * The values for mi_flags.
410  */
411 #define	MI_HARD		0x1		/* hard or soft mount */
412 #define	MI_PRINTED	0x2		/* not responding message printed */
413 #define	MI_INT		0x4		/* interrupts allowed on hard mount */
414 #define	MI_DOWN		0x8		/* server is down */
415 #define	MI_NOAC		0x10		/* don't cache attributes */
416 #define	MI_NOCTO	0x20		/* no close-to-open consistency */
417 #define	MI_DYNAMIC	0x40		/* dynamic transfer size adjustment */
418 #define	MI_LLOCK	0x80		/* local locking only (no lockmgr) */
419 #define	MI_GRPID	0x100		/* System V group id inheritance */
420 #define	MI_RPCTIMESYNC	0x200		/* RPC time sync */
421 #define	MI_LINK		0x400		/* server supports link */
422 #define	MI_SYMLINK	0x800		/* server supports symlink */
423 #define	MI_READDIRONLY	0x1000		/* use readdir instead of readdirplus */
424 #define	MI_ACL		0x2000		/* server supports NFS_ACL */
425 #define	MI_BINDINPROG	0x4000		/* binding to server is changing */
426 #define	MI_LOOPBACK	0x8000		/* Set if this is a loopback mount */
427 #define	MI_SEMISOFT	0x10000		/* soft reads, hard modify */
428 #define	MI_NOPRINT	0x20000		/* don't print messages */
429 #define	MI_DIRECTIO	0x40000		/* do direct I/O */
430 #define	MI_EXTATTR	0x80000		/* server supports extended attrs */
431 #define	MI_ASYNC_MGR_STOP	0x100000	/* tell async mgr to die */
432 #define	MI_DEAD		0x200000	/* mount has been terminated */
433 
434 /*
435  * Read-only mntinfo statistics
436  */
437 struct mntinfo_kstat {
438 	char		mik_proto[KNC_STRSIZE];
439 	uint32_t	mik_vers;
440 	uint_t		mik_flags;
441 	uint_t		mik_secmod;
442 	uint32_t	mik_curread;
443 	uint32_t	mik_curwrite;
444 	int		mik_timeo;
445 	int		mik_retrans;
446 	uint_t		mik_acregmin;
447 	uint_t		mik_acregmax;
448 	uint_t		mik_acdirmin;
449 	uint_t		mik_acdirmax;
450 	struct {
451 		uint32_t srtt;
452 		uint32_t deviate;
453 		uint32_t rtxcur;
454 	} mik_timers[NFS_CALLTYPES+1];
455 	uint32_t	mik_noresponse;
456 	uint32_t	mik_failover;
457 	uint32_t	mik_remap;
458 	char		mik_curserver[SYS_NMLN];
459 };
460 
461 /*
462  * Mark cached attributes as timed out
463  *
464  * The caller must not be holding the rnode r_statelock mutex.
465  */
466 #define	PURGE_ATTRCACHE(vp)	{				\
467 	rnode_t *rp = VTOR(vp);					\
468 	mutex_enter(&rp->r_statelock);				\
469 	PURGE_ATTRCACHE_LOCKED(rp);				\
470 	mutex_exit(&rp->r_statelock);				\
471 }
472 
473 #define	PURGE_ATTRCACHE_LOCKED(rp)	{			\
474 	ASSERT(MUTEX_HELD(&rp->r_statelock));			\
475 	rp->r_attrtime = gethrtime();				\
476 	rp->r_mtime = rp->r_attrtime;				\
477 }
478 
479 /*
480  * Is the attribute cache valid?
481  */
482 #define	ATTRCACHE_VALID(vp)	(gethrtime() < VTOR(vp)->r_attrtime)
483 
484 /*
485  * Flags to indicate whether to purge the DNLC for non-directory vnodes
486  * in a call to nfs_purge_caches.
487  */
488 #define	NFS_NOPURGE_DNLC	0
489 #define	NFS_PURGE_DNLC		1
490 
491 /*
492  * If returned error is ESTALE flush all caches.
493  */
494 #define	PURGE_STALE_FH(error, vp, cr)				\
495 	if ((error) == ESTALE) {				\
496 		struct rnode *rp = VTOR(vp);			\
497 		if (vp->v_flag & VROOT) {			\
498 			servinfo_t *svp = rp->r_server;		\
499 			mutex_enter(&svp->sv_lock);		\
500 			svp->sv_flags |= SV_ROOT_STALE;		\
501 			mutex_exit(&svp->sv_lock);		\
502 		}						\
503 		mutex_enter(&rp->r_statelock);			\
504 		rp->r_flags |= RSTALE;				\
505 		if (!rp->r_error)				\
506 			rp->r_error = (error);			\
507 		mutex_exit(&rp->r_statelock);			\
508 		if (vn_has_cached_data(vp))			\
509 			nfs_invalidate_pages((vp), (u_offset_t)0, (cr)); \
510 		nfs_purge_caches((vp), NFS_PURGE_DNLC, (cr));	\
511 	}
512 
513 /*
514  * Is cache valid?
515  * Swap is always valid, if no attributes (attrtime == 0) or
516  * if mtime matches cached mtime it is valid
517  * NOTE: mtime is now a timestruc_t.
518  * Caller should be holding the rnode r_statelock mutex.
519  */
520 #define	CACHE_VALID(rp, mtime, fsize)				\
521 	((RTOV(rp)->v_flag & VISSWAP) == VISSWAP ||		\
522 	(((mtime).tv_sec == (rp)->r_attr.va_mtime.tv_sec &&	\
523 	(mtime).tv_nsec == (rp)->r_attr.va_mtime.tv_nsec) &&	\
524 	((fsize) == (rp)->r_attr.va_size)))
525 
526 /*
527  * Macro to detect forced unmount or a zone shutdown.
528  */
529 #define	FS_OR_ZONE_GONE(vfsp) \
530 	(((vfsp)->vfs_flag & VFS_UNMOUNTED) || \
531 	zone_status_get(curproc->p_zone) >= ZONE_IS_SHUTTING_DOWN)
532 
533 /*
534  * Convert NFS tunables to hrtime_t units, seconds to nanoseconds.
535  */
536 #define	SEC2HR(sec)	((sec) * (long long)NANOSEC)
537 #define	HR2SEC(hr)	((hr) / (long long)NANOSEC)
538 
539 /*
540  * Structure to identify owner of a PC file share reservation.
541  */
542 struct nfs_owner {
543 	int	magic;		/* magic uniquifying number */
544 	char	hname[16];	/* first 16 bytes of hostname */
545 	char	lowner[8];	/* local owner from fcntl */
546 };
547 
548 /*
549  * Values for magic.
550  */
551 #define	NFS_OWNER_MAGIC	0x1D81E
552 
553 /*
554  * Support for extended attributes
555  */
556 #define	XATTR_DIR_NAME	"/@/"		/* used for DNLC entries */
557 #define	XATTR_RPATH	"ExTaTtR"	/* used for r_path for failover */
558 
559 /*
560  * Short hand for checking to see whether the file system was mounted
561  * interruptible or not.
562  */
563 #define	INTR(vp)	(VTOMI(vp)->mi_flags & MI_INT)
564 
565 /*
566  * Short hand for checking whether failover is enabled or not
567  */
568 #define	FAILOVER_MOUNT(mi)	(mi->mi_servers->sv_next)
569 
570 /*
571  * How long will async threads wait for additional work.
572  */
573 #define	NFS_ASYNC_TIMEOUT	(60 * 1 * hz)	/* 1 minute */
574 
575 #ifdef _KERNEL
576 extern int	clget(clinfo_t *, servinfo_t *, cred_t *, CLIENT **,
577 		    struct chtab **);
578 extern void	clfree(CLIENT *, struct chtab *);
579 extern void	nfs_mi_zonelist_add(mntinfo_t *);
580 extern void	nfs_free_mi(mntinfo_t *);
581 extern void	nfs_mnt_kstat_init(struct vfs *);
582 #endif
583 
584 /*
585  * Per-zone data for managing client handles.  Included here solely for the
586  * benefit of MDB.
587  */
588 /*
589  * client side statistics
590  */
591 struct clstat {
592 	kstat_named_t	calls;			/* client requests */
593 	kstat_named_t	badcalls;		/* rpc failures */
594 	kstat_named_t	clgets;			/* client handle gets */
595 	kstat_named_t	cltoomany;		/* client handle cache misses */
596 #ifdef DEBUG
597 	kstat_named_t	clalloc;		/* number of client handles */
598 	kstat_named_t	noresponse;		/* server not responding cnt */
599 	kstat_named_t	failover;		/* server failover count */
600 	kstat_named_t	remap;			/* server remap count */
601 #endif
602 };
603 
604 struct nfs_clnt {
605 	struct chhead	*nfscl_chtable;
606 	kmutex_t	nfscl_chtable_lock;
607 	zoneid_t	nfscl_zoneid;
608 	list_node_t	nfscl_node;
609 	struct clstat	nfscl_stat;
610 };
611 
612 #ifdef	__cplusplus
613 }
614 #endif
615 
616 #endif	/* _NFS_NFS_CLNT_H */
617