xref: /illumos-gate/usr/src/uts/common/fs/nfs/nfs_log.c (revision 64cfc8ed0c5da83f827c424588bfe709e3fb5a7a)
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 (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #pragma ident	"%Z%%M%	%I%	%E% SMI"
27 
28 #include <sys/cred.h>
29 #include <sys/cmn_err.h>
30 #include <sys/debug.h>
31 #include <sys/systm.h>
32 #include <sys/kmem.h>
33 #include <sys/disp.h>
34 #include <sys/atomic.h>
35 #include <rpc/types.h>
36 #include <nfs/nfs.h>
37 #include <nfs/nfssys.h>
38 #include <nfs/export.h>
39 #include <nfs/rnode.h>
40 #include <rpc/auth.h>
41 #include <rpc/svc.h>
42 #include <rpc/xdr.h>
43 #include <rpc/clnt.h>
44 #include <nfs/nfs_log.h>
45 
46 #define	NUM_RECORDS_TO_WRITE 256
47 #define	NUM_BYTES_TO_WRITE 65536
48 
49 extern krwlock_t exported_lock;
50 
51 static int nfslog_num_records_to_write = NUM_RECORDS_TO_WRITE;
52 static int nfslog_num_bytes_to_write = NUM_BYTES_TO_WRITE;
53 
54 /*
55  * This struct is used to 'hide' the details of managing the log
56  * records internally to the logging code.  Allocation routines
57  * are used to obtain pieces of memory for XDR encoding.  This struct
58  * is a 'header' to those areas and a opaque cookie is used to pass
59  * this data structure between the allocating function and the put
60  * function.
61  */
62 struct lr_alloc {
63 	struct lr_alloc		*next;		/* links for write queuing */
64 	struct lr_alloc		*prev;
65 #define	LR_ALLOC_NOFREE	0x1			/* not present, call free */
66 	int			lr_flags;
67 	caddr_t			log_record;	/* address to XDR encoding */
68 	size_t			size;		/* final size of encoding */
69 	struct kmem_cache	*alloc_cache;	/* keep track of cache ptr */
70 	struct exportinfo	*exi;		/* who are we related to? */
71 	struct log_buffer	*lb;
72 };
73 
74 struct flush_thread_params {
75 	struct nfsl_flush_args tp_args;
76 	int tp_error;
77 };
78 
79 static int log_file_create(caddr_t, struct log_file **);
80 static void log_file_rele(struct log_file *);
81 static struct log_buffer *log_buffer_create(caddr_t);
82 static void log_buffer_rele(struct log_buffer *);
83 static int nfslog_record_append2all(struct lr_alloc *);
84 static int nfslog_logbuffer_rename(struct log_buffer *);
85 static void nfslog_logfile_wait(struct log_file *);
86 static int nfslog_logfile_rename(char *, char *);
87 static void nfslog_do_flush(struct flush_thread_params *);
88 static void create_buffer_header(caddr_t *, size_t *, size_t *);
89 
90 static int nfslog_write_logrecords(struct log_file *, struct lr_alloc *, int);
91 static void nfslog_free_logrecords(struct lr_alloc *);
92 static int nfslog_records_flush_to_disk(struct log_buffer *);
93 static int nfslog_records_flush_to_disk_nolock(struct log_buffer *);
94 
95 /*
96  * Read/Write lock that protects 'nfslog_buffer_list'.
97  * This lock must be held when searching or modifying 'nfslog_buffer_list'.
98  */
99 static krwlock_t nfslog_buffer_list_lock;
100 
101 /*
102  * The list of "log_buffer" structures.
103  */
104 struct log_buffer *nfslog_buffer_list = NULL;
105 
106 
107 #define	LOG_BUFFER_HOLD(lbp)	{ \
108 	mutex_enter(&(lbp)->lb_lock); \
109 	(lbp)->lb_refcnt++; \
110 	mutex_exit(&(lbp)->lb_lock); \
111 }
112 
113 #define	LOG_FILE_HOLD(lfp)	{ \
114 	mutex_enter(&(lfp)->lf_lock); \
115 	(lfp)->lf_refcnt++; \
116 	mutex_exit(&(lfp)->lf_lock); \
117 }
118 
119 #define	LOG_FILE_RELE(lfp)	{ \
120 	log_file_rele(lfp); \
121 }
122 
123 /*
124  * These two macros are used to prep a logfile data structure and
125  * associated file for writing data.  Note that the lf_lock is
126  * held as a result of the call to the first macro.  This is used
127  * for serialization correctness between the logbuffer struct and
128  * the logfile struct.
129  */
130 #define	LOG_FILE_LOCK_TO_WRITE(lfp)	{ \
131 	mutex_enter(&(lfp)->lf_lock); \
132 	(lfp)->lf_refcnt++; \
133 	(lfp)->lf_writers++; \
134 }
135 
136 #define	LOG_FILE_UNLOCK_FROM_WRITE(lfp)	{ \
137 	(lfp)->lf_writers--; \
138 	if ((lfp)->lf_writers == 0 && ((lfp)->lf_flags & L_WAITING)) { \
139 		(lfp)->lf_flags &= ~L_WAITING; \
140 		cv_broadcast(&(lfp)->lf_cv_waiters); \
141 	} \
142 	mutex_exit(&(lfp)->lf_lock); \
143 	log_file_rele(lfp); \
144 }
145 
146 int rfsl_log_buffer = 0;
147 static int rfsl_log_file = 0;
148 
149 /* This array is used for memory allocation of record encoding spaces */
150 static struct {
151 	int	size;
152 	struct kmem_cache *mem_cache;
153 	char	*cache_name;
154 } nfslog_mem_alloc[] = {
155 #define	SMALL_INDX 0
156 	{ NFSLOG_SMALL_RECORD_SIZE - sizeof (struct lr_alloc),
157 	NULL, NFSLOG_SMALL_REC_NAME },
158 #define	MEDIUM_INDX 1
159 	{ NFSLOG_MEDIUM_RECORD_SIZE - sizeof (struct lr_alloc),
160 	NULL, NFSLOG_MEDIUM_REC_NAME },
161 #define	LARGE_INDX 2
162 	{ NFSLOG_LARGE_RECORD_SIZE - sizeof (struct lr_alloc),
163 	NULL, NFSLOG_LARGE_REC_NAME },
164 	{ (-1), NULL }
165 };
166 
167 /* Used to calculate the 'real' allocation size */
168 #define	ALLOC_SIZE(index) \
169 	(nfslog_mem_alloc[index].size + sizeof (struct lr_alloc))
170 
171 /*
172  * Initialize logging data buffer cache
173  */
174 void
175 nfslog_init()
176 {
177 	int indx;
178 
179 	rw_init(&nfslog_buffer_list_lock, NULL, RW_DEFAULT, NULL);
180 
181 	/*
182 	 * Initialize the kmem caches for encoding
183 	 */
184 	for (indx = 0; nfslog_mem_alloc[indx].size != (-1); indx++) {
185 		nfslog_mem_alloc[indx].mem_cache =
186 		    kmem_cache_create(nfslog_mem_alloc[indx].cache_name,
187 		    ALLOC_SIZE(indx), 0, NULL, NULL, NULL, NULL, NULL, 0);
188 	}
189 }
190 
191 /*
192  * Sets up the necessary log file and related buffers to enable logging
193  * on the given export point.
194  * Returns 0 on success, non-zero on failure.
195  */
196 int
197 nfslog_setup(struct exportinfo *exi)
198 {
199 	struct exportdata *kex;
200 	struct log_buffer *lbp;
201 	struct log_buffer *nlbp;
202 
203 	kex = &exi->exi_export;
204 	ASSERT(kex->ex_flags & EX_LOG);
205 
206 	/*
207 	 * Logging is enabled for the new export point, check
208 	 * the existing log_buffer structures to see if the
209 	 * desired buffer has already been opened. If so, point
210 	 * the new exportinfo's exi_logbuffer to the existing
211 	 * one.
212 	 */
213 	rw_enter(&nfslog_buffer_list_lock, RW_READER);
214 	for (lbp = nfslog_buffer_list; lbp != NULL; lbp = lbp->lb_next) {
215 		LOGGING_DPRINT((10,
216 		    "searching for buffer... found log_buffer '%s'\n",
217 		    lbp->lb_path));
218 		if (strcmp(lbp->lb_path, kex->ex_log_buffer) == 0) {
219 			/* Found our match. Ref it and return */
220 			LOG_BUFFER_HOLD(lbp);
221 			exi->exi_logbuffer = lbp;
222 			LOGGING_DPRINT((10,  "\tfound log_buffer for '%s'\n",
223 			    kex->ex_log_buffer));
224 			rw_exit(&nfslog_buffer_list_lock);
225 			return (0);
226 		}
227 	}
228 	rw_exit(&nfslog_buffer_list_lock);
229 
230 	/*
231 	 * New buffer needed, allocate it.
232 	 * The buffer list lock has been dropped so we will need to search
233 	 * the list again to ensure that another thread has not added
234 	 * a matching buffer.
235 	 */
236 	if ((nlbp = log_buffer_create(kex->ex_log_buffer)) == NULL) {
237 		/*
238 		 * Failed the buffer creation for some reason so we
239 		 * will need to return.
240 		 */
241 		return (EIO);
242 	}
243 
244 	rw_enter(&nfslog_buffer_list_lock, RW_WRITER);
245 	for (lbp = nfslog_buffer_list; lbp != NULL;
246 	    lbp = lbp->lb_next) {
247 		if (strcmp(lbp->lb_path, kex->ex_log_buffer) == 0) {
248 				/*
249 				 * A log_buffer already exists for the
250 				 * indicated buffer, use it instead.
251 				 */
252 			LOG_BUFFER_HOLD(lbp);
253 
254 			exi->exi_logbuffer = lbp;
255 
256 			LOGGING_DPRINT((10, "found log_buffer for '%s' "
257 			    "after allocation\n", kex->ex_log_buffer));
258 
259 			rw_exit(&nfslog_buffer_list_lock);
260 
261 			log_buffer_rele(nlbp);
262 
263 			return (0);
264 		}
265 	}
266 	/*
267 	 * Didn't find an existing log_buffer for this buffer,
268 	 * use the the newly created one, and add to list.  We
269 	 * increment the reference count because the node is
270 	 * entered into the global list.
271 	 */
272 	LOGGING_DPRINT((10, "exportfs: adding nlbp=%p to list\n", nlbp));
273 
274 	nlbp->lb_next = nfslog_buffer_list;
275 	nfslog_buffer_list = nlbp;
276 
277 	LOG_BUFFER_HOLD(nlbp);	/* hold is for export entry */
278 	exi->exi_logbuffer = nlbp;
279 
280 	rw_exit(&nfslog_buffer_list_lock);
281 
282 	return (0);
283 }
284 
285 /*
286  * Disables logging for the given export point.
287  */
288 void
289 nfslog_disable(struct exportinfo *exi)
290 {
291 	log_buffer_rele(exi->exi_logbuffer);
292 }
293 
294 /*
295  * Creates the corresponding log_buffer and log_file structures
296  * for the the buffer named 'name'.
297  * Returns a pointer to the log_buffer structure with reference one.
298  */
299 static struct log_buffer *
300 log_buffer_create(caddr_t name)
301 {
302 	struct log_buffer *buffer;
303 	struct log_file *logfile;
304 	int namelen = strlen(name);
305 
306 	LOGGING_DPRINT((10,  "log_buffer_create: %s\n", name));
307 	if (log_file_create(name, &logfile))
308 		return (NULL);
309 
310 	buffer = (struct log_buffer *)kmem_alloc(sizeof (*buffer), KM_SLEEP);
311 	buffer->lb_refcnt = 1;
312 	buffer->lb_rec_id = 0;
313 	buffer->lb_path = (caddr_t)kmem_alloc(namelen + 1, KM_SLEEP);
314 	bcopy(name, buffer->lb_path, namelen + 1);
315 	buffer->lb_logfile = logfile;
316 	buffer->lb_records = NULL;
317 	buffer->lb_num_recs = 0;
318 	buffer->lb_size_queued = 0;
319 	mutex_init(&buffer->lb_lock, NULL, MUTEX_DEFAULT, NULL);
320 	rfsl_log_buffer++;
321 
322 	return (buffer);
323 }
324 
325 /*
326  * Release a log_buffer structure
327  */
328 static void
329 log_buffer_rele(struct log_buffer *lbp)
330 {
331 	int len;
332 
333 	mutex_enter(&lbp->lb_lock);
334 	if (--lbp->lb_refcnt > 1) {
335 		mutex_exit(&lbp->lb_lock);
336 		return;
337 	}
338 
339 	if (lbp->lb_refcnt < 0) {
340 		panic("log_rele: log_buffer refcnt < 0");
341 		/*NOTREACHED*/
342 	}
343 
344 	/*
345 	 * Need to drop the lb_lock before acquiring the
346 	 * nfslog_buffer_list_lock. To avoid double free we need
347 	 * to hold an additional reference to the log buffer.
348 	 * This will ensure that no two threads will simultaneously
349 	 * be trying to free the same log buffer.
350 	 */
351 
352 	if (lbp->lb_refcnt == 1) {
353 
354 		/*
355 		 * If the ref count is 1, then the last
356 		 * unshare/reference has been given up and we need to
357 		 * clean up the buffer and remove it from the buffer
358 		 * list.
359 		 */
360 		LOGGING_DPRINT((10,
361 		    "log_buffer_rele lbp=%p disconnecting\n", lbp));
362 		/*
363 		 * Hold additional reference before dropping the lb_lock
364 		 */
365 
366 		lbp->lb_refcnt++;
367 		mutex_exit(&lbp->lb_lock);
368 
369 		/*
370 		 * Make sure that all of the buffered records are written.
371 		 * Don't bother checking the write return value since there
372 		 * isn't much we can do at this point.
373 		 */
374 		(void) nfslog_records_flush_to_disk(lbp);
375 
376 		rw_enter(&nfslog_buffer_list_lock, RW_WRITER);
377 		mutex_enter(&lbp->lb_lock);
378 		/*
379 		 * Drop the reference count held above.
380 		 * If the ref count is still > 1 then someone has
381 		 * stepped in to use this log buffer.  unlock and return.
382 		 */
383 		if (--lbp->lb_refcnt > 1) {
384 			mutex_exit(&lbp->lb_lock);
385 			rw_exit(&nfslog_buffer_list_lock);
386 			return;
387 		}
388 
389 		if (lbp == nfslog_buffer_list) {
390 			nfslog_buffer_list = lbp->lb_next;
391 		} else {
392 			struct log_buffer *tlbp;
393 
394 			/* Drop the log_buffer from the master list */
395 			for (tlbp = nfslog_buffer_list; tlbp->lb_next != NULL;
396 			    tlbp = tlbp->lb_next) {
397 				if (tlbp->lb_next == lbp) {
398 					tlbp->lb_next = lbp->lb_next;
399 					break;
400 				}
401 			}
402 		}
403 
404 		mutex_exit(&lbp->lb_lock);
405 		rw_exit(&nfslog_buffer_list_lock);
406 	}
407 	/*
408 	 * ref count zero; finish clean up.
409 	 */
410 	LOGGING_DPRINT((10, "log_buffer_rele lbp=%p freeing\n", lbp));
411 
412 	log_file_rele(lbp->lb_logfile);
413 	len = strlen(lbp->lb_path) + 1;
414 	kmem_free(lbp->lb_path, len);
415 	kmem_free(lbp, sizeof (*lbp));
416 	rfsl_log_buffer--;
417 }
418 
419 /*
420  * Creates the corresponding log_file structure for the buffer
421  * named 'log_file_name'.
422  * 'log_file_name' is created by concatenating 'origname' and LOG_INPROG_STRING.
423  * 'logfile' is set to be the log_file structure with reference one.
424  */
425 static int
426 log_file_create(caddr_t origname, struct log_file **lfpp)
427 {
428 	vnode_t *vp = NULL;
429 	char *name;
430 	int namelen;
431 	int error;
432 	struct log_file *logfile = NULL;
433 	vattr_t va;
434 	caddr_t loghdr = NULL;
435 	size_t loghdr_len = 0;
436 	size_t loghdr_free = 0;
437 
438 	namelen = strlen(origname) + strlen(LOG_INPROG_STRING);
439 	name = (caddr_t)kmem_alloc(namelen + 1, KM_SLEEP);
440 	(void) sprintf(name, "%s%s", origname, LOG_INPROG_STRING);
441 
442 	LOGGING_DPRINT((3, "log_file_create: %s\n", name));
443 	if (error = vn_open(name, UIO_SYSSPACE, FCREAT|FWRITE|FOFFMAX,
444 	    LOG_MODE, &vp, CRCREAT, 0)) {
445 		nfs_cmn_err(error, CE_WARN,
446 		    "log_file_create: Can not open %s - error %m", name);
447 		goto out;
448 	}
449 	LOGGING_DPRINT((3, "log_file_create: %s vp=%p v_count=%d\n",
450 	    name, vp, vp->v_count));
451 
452 	logfile = (struct log_file *)kmem_zalloc(sizeof (*logfile), KM_SLEEP);
453 	logfile->lf_path = name;
454 	/*
455 	 * No need to bump the vnode reference count since it is set
456 	 * to one by vn_open().
457 	 */
458 	logfile->lf_vp = vp;
459 	logfile->lf_refcnt = 1;
460 	mutex_init(&logfile->lf_lock, NULL, MUTEX_DEFAULT, NULL);
461 	rfsl_log_file++;
462 
463 	va.va_mask = AT_SIZE;
464 	error = VOP_GETATTR(vp, &va, 0, CRED());
465 	if (error) {
466 		nfs_cmn_err(error, CE_WARN,
467 		    "log_file_create: Can not stat %s - error = %m",  name);
468 		goto out;
469 	}
470 
471 	if (va.va_size == 0) {
472 		struct lr_alloc lr;
473 
474 		/*
475 		 * Write Header.
476 		 */
477 		create_buffer_header(&loghdr, &loghdr_len, &loghdr_free);
478 		/*
479 		 * Dummy up a lr_alloc struct for the write
480 		 */
481 		lr.next = lr.prev = &lr;
482 		lr.lr_flags = 0;
483 		lr.log_record = loghdr;
484 		lr.size = loghdr_len;
485 		lr.alloc_cache = NULL;
486 		lr.exi = NULL;
487 		lr.lb = NULL;
488 
489 		mutex_enter(&logfile->lf_lock);
490 
491 		error = nfslog_write_logrecords(logfile, &lr, 1);
492 
493 		mutex_exit(&logfile->lf_lock);
494 
495 		if (error != 0) {
496 			nfs_cmn_err(error, CE_WARN,
497 			    "log_file_create: Can not write header "
498 			    "on %s - error = %m", name);
499 			goto out;
500 		}
501 	}
502 	*lfpp = logfile;
503 
504 	if (loghdr != NULL)
505 		kmem_free(loghdr, loghdr_free);
506 
507 	return (0);
508 
509 out:
510 	if (vp != NULL) {
511 		int error1;
512 		error1 = VOP_CLOSE(vp, FCREAT|FWRITE|FOFFMAX, 1, (offset_t)0,
513 		    CRED());
514 		if (error1) {
515 			nfs_cmn_err(error1, CE_WARN,
516 			    "log_file_create: Can not close %s - "
517 			    "error = %m", name);
518 		}
519 		VN_RELE(vp);
520 	}
521 
522 	kmem_free(name, namelen + 1);
523 	if (logfile != NULL) {
524 		mutex_destroy(&logfile->lf_lock);
525 		kmem_free(logfile, sizeof (*logfile));
526 		rfsl_log_file--;
527 	}
528 	if (loghdr != NULL)
529 		kmem_free(loghdr, loghdr_free);
530 
531 	return (error);
532 }
533 
534 /*
535  * Release a log_file structure
536  */
537 static void
538 log_file_rele(struct log_file *lfp)
539 {
540 	int len;
541 	int error;
542 
543 	mutex_enter(&lfp->lf_lock);
544 	if (--lfp->lf_refcnt > 0) {
545 		LOGGING_DPRINT((10,
546 		    "log_file_rele lfp=%p decremented refcnt to %d\n",
547 		    lfp, lfp->lf_refcnt));
548 		mutex_exit(&lfp->lf_lock);
549 		return;
550 	}
551 	if (lfp->lf_refcnt < 0) {
552 		panic("log_file_rele: log_file refcnt < 0");
553 		/*NOTREACHED*/
554 	}
555 
556 	LOGGING_DPRINT((10, "log_file_rele lfp=%p freeing node\n", lfp));
557 
558 	lfp->lf_flags &= ~(L_PRINTED | L_ERROR);
559 
560 	ASSERT(lfp->lf_flags == 0);
561 	ASSERT(lfp->lf_writers == 0);
562 
563 	if (error = VOP_CLOSE(lfp->lf_vp, FCREAT|FWRITE|FOFFMAX, 1, (offset_t)0,
564 	    CRED())) {
565 		nfs_cmn_err(error, CE_WARN,
566 		    "NFS: Could not close log buffer %s - error = %m",
567 		    lfp->lf_path);
568 #ifdef DEBUG
569 	} else {
570 		LOGGING_DPRINT((3,
571 		    "log_file_rele: %s has been closed vp=%p v_count=%d\n",
572 		    lfp->lf_path, lfp->lf_vp, lfp->lf_vp->v_count));
573 #endif
574 	}
575 	VN_RELE(lfp->lf_vp);
576 
577 	len = strlen(lfp->lf_path) + 1;
578 	kmem_free(lfp->lf_path, len);
579 	kmem_free(lfp, sizeof (*lfp));
580 	rfsl_log_file--;
581 }
582 
583 /*
584  * Allocates a record of the size specified.
585  * 'exi' identifies the exportinfo structure being logged.
586  * 'size' indicates how much memory should be allocated
587  * 'cookie' is used to store an opaque value for the caller for later use
588  * 'flags' currently ignored.
589  *
590  * Returns a pointer to the beginning of the allocated memory.
591  * 'cookie' is a pointer to the 'lr_alloc' struct; this will be used
592  * to keep track of the encoded record and contains all the info
593  * for enqueuing the record on the log buffer for later writing.
594  *
595  * nfslog_record_put() must be used to 'free' this record or allocation.
596  */
597 /* ARGSUSED */
598 void *
599 nfslog_record_alloc(
600 	struct exportinfo *exi,
601 	int alloc_indx,
602 	void **cookie,
603 	int flags)
604 {
605 	struct lr_alloc *lrp;
606 
607 	lrp = (struct lr_alloc *)
608 	    kmem_cache_alloc(nfslog_mem_alloc[alloc_indx].mem_cache,
609 	    KM_NOSLEEP);
610 
611 	if (lrp == NULL) {
612 		*cookie = NULL;
613 		return (NULL);
614 	}
615 
616 	lrp->next = lrp;
617 	lrp->prev = lrp;
618 	lrp->lr_flags = 0;
619 
620 	lrp->log_record = (caddr_t)((uintptr_t)lrp +
621 	    (uintptr_t)sizeof (struct lr_alloc));
622 	lrp->size = nfslog_mem_alloc[alloc_indx].size;
623 	lrp->alloc_cache = nfslog_mem_alloc[alloc_indx].mem_cache;
624 	lrp->exi = exi;
625 
626 	if (exi->exi_export.ex_flags & EX_LOG) {
627 		LOG_BUFFER_HOLD(exi->exi_logbuffer);
628 		lrp->lb = exi->exi_logbuffer;
629 	} else {
630 		lrp->lb = NULL;
631 	}
632 
633 	*cookie = (void *)lrp;
634 
635 	LOGGING_DPRINT((3,
636 	    "nfslog_record_alloc(log_buffer=%p mem=%p size=%lu)\n",
637 	    exi->exi_logbuffer, lrp->log_record, lrp->size));
638 	return (lrp->log_record);
639 }
640 
641 /*
642  * After the above nfslog_record_alloc() has been called and a record
643  * encoded into the buffer that was returned, this function is called
644  * to handle appropriate disposition of the newly created record.
645  * The cookie value is the one that was returned from nfslog_record_alloc().
646  * Size is the actual size of the record that was encoded.  This is
647  * passed in because the size used for the alloc was just an approximation.
648  * The sync parameter is used to tell us if we need to force this record
649  * to disk and if not it will be queued for later writing.
650  *
651  * Note that if the size parameter has a value of 0, then the record is
652  * not written to the log and the associated data structures are released.
653  */
654 void
655 nfslog_record_put(void *cookie, size_t size, bool_t sync,
656 	unsigned int which_buffers)
657 {
658 	struct lr_alloc *lrp = (struct lr_alloc *)cookie;
659 	struct log_buffer *lbp = lrp->lb;
660 
661 	/*
662 	 * If the caller has nothing to write or if there is
663 	 * an apparent error, rele the buffer and free.
664 	 */
665 	if (size == 0 || size > lrp->size) {
666 		nfslog_free_logrecords(lrp);
667 		return;
668 	}
669 
670 	/*
671 	 * Reset the size to what actually needs to be written
672 	 * This is used later on when the iovec is built for
673 	 * writing the records to the log file.
674 	 */
675 	lrp->size = size;
676 
677 	/* append to all if public exi */
678 	if (which_buffers == NFSLOG_ALL_BUFFERS) {
679 		(void) nfslog_record_append2all(lrp);
680 		nfslog_free_logrecords(lrp);
681 		return;
682 	}
683 
684 	/* Insert the record on the list to be written */
685 	mutex_enter(&lbp->lb_lock);
686 	if (lbp->lb_records == NULL) {
687 		lbp->lb_records = (caddr_t)lrp;
688 		lbp->lb_num_recs = 1;
689 		lbp->lb_size_queued = lrp->size;
690 	} else {
691 		insque(lrp, ((struct lr_alloc *)lbp->lb_records)->prev);
692 		lbp->lb_num_recs++;
693 		lbp->lb_size_queued += lrp->size;
694 	}
695 
696 	/*
697 	 * Determine if the queue for this log buffer should be flushed.
698 	 * This is done by either the number of records queued, the total
699 	 * size of all records queued or by the request of the caller
700 	 * via the sync parameter.
701 	 */
702 	if (lbp->lb_size_queued >= nfslog_num_bytes_to_write ||
703 	    lbp->lb_num_recs > nfslog_num_records_to_write || sync == TRUE) {
704 		mutex_exit(&lbp->lb_lock);
705 		(void) nfslog_records_flush_to_disk(lbp);
706 	} else {
707 		mutex_exit(&lbp->lb_lock);
708 	}
709 
710 }
711 
712 /*
713  * Examine the log_buffer struct to see if there are queue log records
714  * that need to be written to disk.  If some exist, pull them off of
715  * the log buffer and write them to the log file.
716  */
717 static int
718 nfslog_records_flush_to_disk(struct log_buffer *lbp)
719 {
720 
721 	mutex_enter(&lbp->lb_lock);
722 
723 	if (lbp->lb_records == NULL) {
724 		mutex_exit(&lbp->lb_lock);
725 		return (0);
726 	}
727 	return	(nfslog_records_flush_to_disk_nolock(lbp));
728 }
729 
730 /*
731  * Function requires that the caller holds lb_lock.
732  * Function flushes any records in the log buffer to the disk.
733  * Function drops the lb_lock on return.
734  */
735 
736 static int
737 nfslog_records_flush_to_disk_nolock(struct log_buffer *lbp)
738 {
739 	struct log_file *lfp = NULL;
740 	struct lr_alloc *lrp_writers;
741 	int num_recs;
742 	int error = 0;
743 
744 	ASSERT(MUTEX_HELD(&lbp->lb_lock));
745 
746 	lfp = lbp->lb_logfile;
747 
748 	LOG_FILE_LOCK_TO_WRITE(lfp);
749 	ASSERT(lbp->lb_records != NULL);
750 
751 	lrp_writers = (struct lr_alloc *)lbp->lb_records;
752 	lbp->lb_records = NULL;
753 	num_recs = lbp->lb_num_recs;
754 	lbp->lb_num_recs = 0;
755 	lbp->lb_size_queued = 0;
756 	mutex_exit(&lbp->lb_lock);
757 	error = nfslog_write_logrecords(lfp, lrp_writers, num_recs);
758 
759 	LOG_FILE_UNLOCK_FROM_WRITE(lfp);
760 
761 	nfslog_free_logrecords(lrp_writers);
762 	return (error);
763 }
764 
765 
766 /*
767  * Take care of writing the provided log record(s) to the log file.
768  * We group the log records with an iovec and use VOP_WRITE to append
769  * them to the end of the log file.
770  */
771 static int
772 nfslog_write_logrecords(struct log_file *lfp,
773 	struct lr_alloc *lrp_writers, int num_recs)
774 {
775 	struct uio uio;
776 	struct iovec *iovp;
777 	int size_iovecs;
778 	vnode_t *vp;
779 	struct vattr va;
780 	struct lr_alloc *lrp;
781 	int i;
782 	ssize_t len;
783 	int ioflag = FAPPEND;
784 	int error = 0;
785 
786 	ASSERT(MUTEX_HELD(&lfp->lf_lock));
787 
788 	vp = lfp->lf_vp;
789 
790 	size_iovecs = sizeof (struct iovec) * num_recs;
791 	iovp = (struct iovec *)kmem_alloc(size_iovecs, KM_NOSLEEP);
792 
793 	if (iovp == NULL) {
794 		error = ENOMEM;
795 		goto out;
796 	}
797 
798 	/* Build the iovec based on the list of log records */
799 	i = 0;
800 	len = 0;
801 	lrp = lrp_writers;
802 	do {
803 		iovp[i].iov_base = lrp->log_record;
804 		iovp[i].iov_len = lrp->size;
805 		len += lrp->size;
806 		lrp = lrp->next;
807 		i++;
808 	} while (lrp != lrp_writers);
809 
810 	ASSERT(i == num_recs);
811 
812 	uio.uio_iov = iovp;
813 	uio.uio_iovcnt = num_recs;
814 	uio.uio_loffset = 0;
815 	uio.uio_segflg = (short)UIO_SYSSPACE;
816 	uio.uio_resid = len;
817 	uio.uio_llimit = (rlim64_t)MAXOFFSET_T;
818 	uio.uio_fmode = FWRITE;
819 	uio.uio_extflg = UIO_COPY_DEFAULT;
820 
821 	/*
822 	 * Save the size. If the write fails, reset the size to avoid
823 	 * corrupted log buffer files.
824 	 */
825 	va.va_mask = AT_SIZE;
826 
827 	(void) VOP_RWLOCK(vp, V_WRITELOCK_TRUE, NULL);  /* UIO_WRITE */
828 	if ((error = VOP_GETATTR(vp, &va, 0, CRED())) == 0) {
829 		if ((len + va.va_size) < (MAXOFF32_T)) {
830 			error = VOP_WRITE(vp, &uio, ioflag, CRED(), NULL);
831 			VOP_RWUNLOCK(vp, V_WRITELOCK_TRUE, NULL);
832 			if (uio.uio_resid)
833 				error = ENOSPC;
834 			if (error)
835 				(void) VOP_SETATTR(vp, &va, 0, CRED(), NULL);
836 		} else {
837 			VOP_RWUNLOCK(vp, V_WRITELOCK_TRUE, NULL);
838 			if (!(lfp->lf_flags & L_PRINTED)) {
839 				cmn_err(CE_WARN,
840 				    "NFS Logging: buffer file %s exceeds 2GB; "
841 				    "stopped writing buffer \n", lfp->lf_path);
842 			}
843 			error = ENOSPC;
844 		}
845 	} else {
846 		VOP_RWUNLOCK(vp, V_WRITELOCK_TRUE, NULL);
847 	}
848 
849 	kmem_free(iovp, size_iovecs);
850 
851 out:
852 	if (error) {
853 		if (!(lfp->lf_flags & L_PRINTED)) {
854 			nfs_cmn_err(error, CE_WARN,
855 			    "NFS Logging disabled for buffer %s - "
856 			    "write error = %m\n", lfp->lf_path);
857 			lfp->lf_flags |= L_PRINTED;
858 		}
859 	} else if (lfp->lf_flags & (L_ERROR | L_PRINTED)) {
860 		lfp->lf_flags &= ~(L_ERROR | L_PRINTED);
861 		cmn_err(CE_WARN,
862 		    "NFS Logging re-enabled for buffer %s\n", lfp->lf_path);
863 	}
864 
865 	return (error);
866 }
867 
868 static void
869 nfslog_free_logrecords(struct lr_alloc *lrp_writers)
870 {
871 	struct lr_alloc *lrp = lrp_writers;
872 	struct lr_alloc *lrp_free;
873 
874 	do {
875 		lrp_free = lrp;
876 
877 		lrp = lrp->next;
878 
879 		/*
880 		 * Check to see if we are supposed to free this structure
881 		 * and relese the log_buffer ref count.
882 		 * It may be the case that the caller does not want this
883 		 * structure and its record contents freed just yet.
884 		 */
885 		if ((lrp_free->lr_flags & LR_ALLOC_NOFREE) == 0) {
886 			if (lrp_free->lb != NULL)
887 				log_buffer_rele(lrp_free->lb);
888 			if (lrp_free->alloc_cache) /* double check */
889 				kmem_cache_free(lrp_free->alloc_cache,
890 				    (void *)lrp_free);
891 		} else {
892 			/*
893 			 * after being pulled from the list the
894 			 * pointers need to be reinitialized.
895 			 */
896 			lrp_free->next = lrp_free;
897 			lrp_free->prev = lrp_free;
898 		}
899 
900 	} while (lrp != lrp_writers);
901 }
902 
903 /*
904  * Rename lbp->lb_logfile to reflect the true name requested by 'share'
905  */
906 static int
907 nfslog_logbuffer_rename(struct log_buffer *lbp)
908 {
909 	struct log_file *lf;
910 	int error;
911 	struct log_file *logfile;
912 
913 	/*
914 	 * Try our best to get the cache records into the log file
915 	 * before the rename occurs.
916 	 */
917 	(void) nfslog_records_flush_to_disk(lbp);
918 
919 	/*
920 	 * Hold lb_lock before retrieving
921 	 * lb_logfile.
922 	 * Hold a reference to the
923 	 * "lf" structure. this is
924 	 * same as LOG_FILE_HOLD()
925 	 */
926 	mutex_enter(&(lbp)->lb_lock);
927 	lf = lbp->lb_logfile;
928 	mutex_enter(&(lf)->lf_lock);
929 	mutex_exit(&(lbp)->lb_lock);
930 	lf->lf_refcnt++;
931 	mutex_exit(&(lf)->lf_lock);
932 
933 	LOGGING_DPRINT((10, "nfslog_logbuffer_rename: renaming %s to %s\n",
934 	    lf->lf_path, lbp->lb_path));
935 
936 	/*
937 	 * rename the current buffer to what the daemon expects
938 	 */
939 	if (error = nfslog_logfile_rename(lf->lf_path, lbp->lb_path))
940 		goto out;
941 
942 	/*
943 	 * Create a new working buffer file and have all new data sent there.
944 	 */
945 	if (error = log_file_create(lbp->lb_path, &logfile)) {
946 		/* Attempt to rename to original */
947 		(void) nfslog_logfile_rename(lbp->lb_path, lf->lf_path);
948 		goto out;
949 	}
950 
951 	/*
952 	 * Hold the lb_lock here, this will make
953 	 * all the threads trying to access lb->logfile block
954 	 * and get a new logfile structure instead of old one.
955 	 */
956 	mutex_enter(&(lbp)->lb_lock);
957 	lbp->lb_logfile = logfile;
958 	mutex_exit(&(lbp)->lb_lock);
959 
960 	LOG_FILE_RELE(lf);	/* release log_buffer's reference */
961 
962 	/*
963 	 * Wait for log_file to be in a quiescent state before we
964 	 * return to our caller to let it proceed with the reading of
965 	 * this file.
966 	 */
967 	nfslog_logfile_wait(lf);
968 
969 out:
970 	/*
971 	 * Release our reference on "lf" in two different cases.
972 	 * 1. Error condition, release only the reference
973 	 *    that we held at the begining of this
974 	 *    routine on "lf" structure.
975 	 * 2. Fall through condition, no errors but the old
976 	 *    logfile structure "lf" has been replaced with
977 	 *    the new "logfile" structure, so release the
978 	 *    reference that was part of the creation of
979 	 *    "lf" structure to free up the resources.
980 	 */
981 
982 	LOG_FILE_RELE(lf);
983 
984 	return (error);
985 }
986 
987 /*
988  * Renames the 'from' file to 'new'.
989  */
990 static int
991 nfslog_logfile_rename(char *from, char *new)
992 {
993 	int error;
994 
995 	if (error = vn_rename(from, new, UIO_SYSSPACE)) {
996 		cmn_err(CE_WARN,
997 		    "nfslog_logfile_rename: couldn't rename %s to %s\n",
998 		    from, new);
999 	}
1000 	return (error);
1001 }
1002 
1003 /*
1004  * Wait for the log_file writers to finish before returning
1005  */
1006 static void
1007 nfslog_logfile_wait(struct log_file *lf)
1008 {
1009 	mutex_enter(&lf->lf_lock);
1010 	while (lf->lf_writers > 0) {
1011 		lf->lf_flags |= L_WAITING;
1012 		(void) cv_wait_sig(&lf->lf_cv_waiters, &lf->lf_lock);
1013 	}
1014 	mutex_exit(&lf->lf_lock);
1015 }
1016 
1017 static int
1018 nfslog_record_append2all(struct lr_alloc *lrp)
1019 {
1020 	struct log_buffer *lbp, *nlbp;
1021 	int error, ret_error = 0;
1022 	int lr_flags = lrp->lr_flags;
1023 
1024 	rw_enter(&nfslog_buffer_list_lock, RW_READER);
1025 	if ((lbp = nfslog_buffer_list) != NULL)
1026 		LOG_BUFFER_HOLD(lbp);
1027 	for (nlbp = NULL; lbp != NULL; lbp = nlbp) {
1028 		if ((nlbp = lbp->lb_next) != NULL) {
1029 			/*
1030 			 * Remember next element in the list
1031 			 */
1032 			LOG_BUFFER_HOLD(nlbp);
1033 		}
1034 		rw_exit(&nfslog_buffer_list_lock);
1035 
1036 		/*
1037 		 * Insert the record on the buffer's list to be written
1038 		 * and then flush the records to the log file.
1039 		 * Make sure to set the no free flag so that the
1040 		 * record can be used for the next write
1041 		 */
1042 		lrp->lr_flags = LR_ALLOC_NOFREE;
1043 
1044 		ASSERT(lbp != NULL);
1045 		mutex_enter(&lbp->lb_lock);
1046 		if (lbp->lb_records == NULL) {
1047 			lbp->lb_records = (caddr_t)lrp;
1048 			lbp->lb_num_recs = 1;
1049 			lbp->lb_size_queued = lrp->size;
1050 		} else {
1051 			insque(lrp, ((struct lr_alloc *)lbp->lb_records)->prev);
1052 			lbp->lb_num_recs++;
1053 			lbp->lb_size_queued += lrp->size;
1054 		}
1055 
1056 		/*
1057 		 * Flush log records to disk.
1058 		 * Function is called with lb_lock held.
1059 		 * Function drops the lb_lock on return.
1060 		 */
1061 		error = nfslog_records_flush_to_disk_nolock(lbp);
1062 
1063 		if (error) {
1064 			ret_error = -1;
1065 			nfs_cmn_err(error, CE_WARN,
1066 			    "rfsl_log_pubfh: could not append record to "
1067 			    "\"%s\" error = %m\n", lbp->lb_path);
1068 		}
1069 		log_buffer_rele(lbp);
1070 		rw_enter(&nfslog_buffer_list_lock, RW_READER);
1071 	}
1072 	rw_exit(&nfslog_buffer_list_lock);
1073 
1074 	lrp->lr_flags = lr_flags;
1075 
1076 	return (ret_error);
1077 }
1078 
1079 #ifdef DEBUG
1080 static int logging_debug = 0;
1081 
1082 /*
1083  * 0) no debugging
1084  * 3) current test software
1085  * 10) random stuff
1086  */
1087 void
1088 nfslog_dprint(const int level, const char *fmt, ...)
1089 {
1090 	va_list args;
1091 
1092 	if (logging_debug == level ||
1093 	    (logging_debug > 10 && (logging_debug - 10) >= level)) {
1094 		va_start(args, fmt);
1095 		(void) vprintf(fmt, args);
1096 		va_end(args);
1097 	}
1098 }
1099 
1100 #endif /* DEBUG */
1101 
1102 /*
1103  * NFS Log Flush system call
1104  * Caller must check privileges.
1105  */
1106 /* ARGSUSED */
1107 int
1108 nfsl_flush(struct nfsl_flush_args *args, model_t model)
1109 {
1110 	struct flush_thread_params *tparams;
1111 	struct nfsl_flush_args *nfsl_args;
1112 	int error = 0;
1113 	ulong_t buffer_len;
1114 	STRUCT_HANDLE(nfsl_flush_args, uap);
1115 
1116 	STRUCT_SET_HANDLE(uap, model, args);
1117 
1118 	tparams = (struct flush_thread_params *)
1119 	    kmem_zalloc(sizeof (*tparams), KM_SLEEP);
1120 
1121 	nfsl_args = &tparams->tp_args;
1122 	nfsl_args->version =  STRUCT_FGET(uap, version);
1123 	if (nfsl_args->version != NFSL_FLUSH_ARGS_VERS) {
1124 		cmn_err(CE_WARN, "nfsl_flush: exected version %d, got %d",
1125 		    NFSL_FLUSH_ARGS_VERS, nfsl_args->version);
1126 		return (EIO);
1127 	}
1128 
1129 	nfsl_args->directive = STRUCT_FGET(uap, directive);
1130 	if ((nfsl_args->directive & NFSL_ALL) == 0) {
1131 		/*
1132 		 * Process a specific buffer
1133 		 */
1134 		nfsl_args->buff_len = STRUCT_FGET(uap, buff_len);
1135 
1136 		nfsl_args->buff = (char *)
1137 		    kmem_alloc(nfsl_args->buff_len, KM_NOSLEEP);
1138 		if (nfsl_args->buff == NULL)
1139 			return (ENOMEM);
1140 
1141 		error = copyinstr((const char *)STRUCT_FGETP(uap, buff),
1142 		    nfsl_args->buff, nfsl_args->buff_len, &buffer_len);
1143 		if (error)
1144 			return (EFAULT);
1145 
1146 		if (nfsl_args->buff_len != buffer_len)
1147 			return (EFAULT);
1148 	}
1149 
1150 	LOGGING_DPRINT((10, "nfsl_flush: Flushing %s buffer(s)\n",
1151 	    nfsl_args->directive & NFSL_ALL ? "all" : nfsl_args->buff));
1152 
1153 	if (nfsl_args->directive & NFSL_SYNC) {
1154 		/*
1155 		 * Do the work synchronously
1156 		 */
1157 		nfslog_do_flush(tparams);
1158 		error = tparams->tp_error;
1159 		kmem_free(nfsl_args->buff, nfsl_args->buff_len);
1160 		kmem_free(tparams, sizeof (*tparams));
1161 	} else {
1162 		/*
1163 		 * Do the work asynchronously
1164 		 */
1165 		(void) thread_create(NULL, 0, nfslog_do_flush,
1166 		    tparams, 0, &p0, TS_RUN, minclsyspri);
1167 	}
1168 
1169 	return (error);
1170 }
1171 
1172 /*
1173  * This is where buffer flushing would occur, but there is no buffering
1174  * at this time.
1175  * Possibly rename the log buffer for processing.
1176  * Sets tparams->ta_error equal to the value of the error that occured,
1177  * 0 otherwise.
1178  * Returns ENOENT if the buffer is not found.
1179  */
1180 static void
1181 nfslog_do_flush(struct flush_thread_params *tparams)
1182 {
1183 	struct nfsl_flush_args *args;
1184 	struct log_buffer *lbp, *nlbp;
1185 	int error = ENOENT;
1186 	int found = 0;
1187 	char *buf_inprog;	/* name of buff in progress */
1188 	int buf_inprog_len;
1189 
1190 	/*
1191 	 * Sanity check on the arguments.
1192 	 */
1193 	if (!tparams)
1194 		return;
1195 	args = &tparams->tp_args;
1196 	if (!args)
1197 		return;
1198 
1199 	rw_enter(&nfslog_buffer_list_lock, RW_READER);
1200 	if ((lbp = nfslog_buffer_list) != NULL) {
1201 		LOG_BUFFER_HOLD(lbp);
1202 	}
1203 	for (nlbp = NULL; lbp != NULL; lbp = nlbp) {
1204 		if ((nlbp = lbp->lb_next) != NULL) {
1205 			LOG_BUFFER_HOLD(nlbp);
1206 		}
1207 		rw_exit(&nfslog_buffer_list_lock);
1208 		if (args->directive & NFSL_ALL) {
1209 			(void) nfslog_records_flush_to_disk(lbp);
1210 		} else {
1211 			if ((strcmp(lbp->lb_path, args->buff) == 0) &&
1212 			    (args->directive & NFSL_RENAME)) {
1213 				error = nfslog_logbuffer_rename(lbp);
1214 				found++;
1215 				if (nlbp != NULL)
1216 					log_buffer_rele(nlbp);
1217 				log_buffer_rele(lbp);
1218 				break;
1219 			}
1220 		}
1221 		log_buffer_rele(lbp);
1222 		rw_enter(&nfslog_buffer_list_lock, RW_READER);
1223 	}
1224 	if (!found)
1225 		rw_exit(&nfslog_buffer_list_lock);
1226 
1227 	if (!found && ((args->directive & NFSL_ALL) == 0) &&
1228 	    (args->directive & NFSL_RENAME)) {
1229 		/*
1230 		 * The specified buffer is not currently in use,
1231 		 * simply rename the file indicated.
1232 		 */
1233 		buf_inprog_len = strlen(args->buff) +
1234 		    strlen(LOG_INPROG_STRING) + 1;
1235 		buf_inprog = (caddr_t)kmem_alloc(buf_inprog_len, KM_SLEEP);
1236 		(void) sprintf(buf_inprog, "%s%s",
1237 		    args->buff, LOG_INPROG_STRING);
1238 
1239 		error = nfslog_logfile_rename(buf_inprog, args->buff);
1240 
1241 		kmem_free(buf_inprog, buf_inprog_len);
1242 	}
1243 
1244 out:
1245 	if ((args->directive & NFSL_SYNC) == 0) {
1246 		/*
1247 		 * Work was performed asynchronously, the caller is
1248 		 * no longer waiting for us.
1249 		 * Free the thread arguments and exit.
1250 		 */
1251 		kmem_free(args->buff, args->buff_len);
1252 		kmem_free(tparams, sizeof (*tparams));
1253 		thread_exit();
1254 		/* NOTREACHED */
1255 	}
1256 
1257 	tparams->tp_error = error;
1258 }
1259 
1260 /*
1261  * Generate buffer_header.
1262  * 'loghdr' points the the buffer_header, and *reclen
1263  * contains the length of the buffer.
1264  */
1265 static void
1266 create_buffer_header(caddr_t *loghdr, size_t *reclen, size_t *freesize)
1267 {
1268 	timestruc_t		now;
1269 	nfslog_buffer_header	lh;
1270 	XDR			xdrs;
1271 	unsigned int		final_size;
1272 
1273 
1274 	/* pick some size that will hold the buffer_header */
1275 	*freesize = NFSLOG_SMALL_RECORD_SIZE;
1276 
1277 	/*
1278 	 * Fill header
1279 	 */
1280 	lh.bh_length = 0;	/* don't know yet how large it will be */
1281 	lh.bh_version = NFSLOG_BUF_VERSION;
1282 	lh.bh_flags = 0;
1283 	lh.bh_offset = 0;
1284 	gethrestime(&now);
1285 	TIMESPEC_TO_TIMESPEC32(&lh.bh_timestamp, &now);
1286 
1287 	/*
1288 	 * Encode the header
1289 	 */
1290 	*loghdr = (caddr_t)kmem_alloc(*freesize, KM_SLEEP);
1291 	xdrmem_create(&xdrs, *loghdr, *freesize, XDR_ENCODE);
1292 
1293 	(void) xdr_nfslog_buffer_header(&xdrs, &lh);
1294 
1295 	/*
1296 	 * Reset with final size of the encoded data
1297 	 */
1298 	final_size = xdr_getpos(&xdrs);
1299 	xdr_setpos(&xdrs, 0);
1300 	(void) xdr_u_int(&xdrs, &final_size);
1301 
1302 	*reclen = (size_t)final_size;
1303 }
1304 
1305 /*
1306  * ****************************************************************
1307  * RPC dispatch table for logging
1308  * Indexed by program, version, proc
1309  * Based on NFS dispatch table.
1310  */
1311 struct nfslog_proc_disp {
1312 	bool_t	(*xdrargs)();
1313 	bool_t	(*xdrres)();
1314 	bool_t	affects_transactions;	/* Operation affects transaction */
1315 					/* processing */
1316 };
1317 
1318 struct nfslog_vers_disp {
1319 	int	nfslog_dis_nprocs;			/* number of procs */
1320 	struct nfslog_proc_disp	*nfslog_dis_proc_table;	/* proc array */
1321 };
1322 
1323 struct nfslog_prog_disp {
1324 	int	nfslog_dis_prog;		/* program number */
1325 	int	nfslog_dis_versmin;		/* Minimum version value */
1326 	int	nfslog_dis_nvers;		/* Number of version values */
1327 	struct nfslog_vers_disp	*nfslog_dis_vers_table;	/* versions array */
1328 };
1329 
1330 static int rfs_log_bad = 0;	/* incremented on bad log attempts */
1331 static int rfs_log_good = 0;	/* incremented on successful log attempts */
1332 
1333 /*
1334  * Define the actions taken per prog/vers/proc:
1335  *
1336  * In some cases, the nl types are the same as the nfs types and a simple
1337  * bcopy should suffice. Rather that define tens of identical procedures,
1338  * simply define these to bcopy. Similarly this takes care of different
1339  * procs that use same parameter struct.
1340  */
1341 
1342 static struct nfslog_proc_disp nfslog_proc_v2[] = {
1343 	/*
1344 	 * NFS VERSION 2
1345 	 */
1346 
1347 	/* RFS_NULL = 0 */
1348 	{xdr_void, xdr_void, FALSE},
1349 
1350 	/* RFS_GETATTR = 1 */
1351 	{xdr_fhandle, xdr_nfslog_getattrres, FALSE},
1352 
1353 	/* RFS_SETATTR = 2 */
1354 	{xdr_nfslog_setattrargs, xdr_nfsstat, TRUE},
1355 
1356 	/* RFS_ROOT = 3 *** NO LONGER SUPPORTED *** */
1357 	{xdr_void, xdr_void, FALSE},
1358 
1359 	/* RFS_LOOKUP = 4 */
1360 	{xdr_nfslog_diropargs, xdr_nfslog_diropres, TRUE},
1361 
1362 	/* RFS_READLINK = 5 */
1363 	{xdr_fhandle, xdr_nfslog_rdlnres, FALSE},
1364 
1365 	/* RFS_READ = 6 */
1366 	{xdr_nfslog_nfsreadargs, xdr_nfslog_rdresult, TRUE},
1367 
1368 	/* RFS_WRITECACHE = 7 *** NO LONGER SUPPORTED *** */
1369 	{xdr_void, xdr_void, FALSE},
1370 
1371 	/* RFS_WRITE = 8 */
1372 	{xdr_nfslog_writeargs, xdr_nfslog_writeresult, TRUE},
1373 
1374 	/* RFS_CREATE = 9 */
1375 	{xdr_nfslog_createargs, xdr_nfslog_diropres, TRUE},
1376 
1377 	/* RFS_REMOVE = 10 */
1378 	{xdr_nfslog_diropargs, xdr_nfsstat, TRUE},
1379 
1380 	/* RFS_RENAME = 11 */
1381 	{xdr_nfslog_rnmargs, xdr_nfsstat, TRUE},
1382 
1383 	/* RFS_LINK = 12 */
1384 	{xdr_nfslog_linkargs, xdr_nfsstat, TRUE},
1385 
1386 	/* RFS_SYMLINK = 13 */
1387 	{xdr_nfslog_symlinkargs, xdr_nfsstat, TRUE},
1388 
1389 	/* RFS_MKDIR = 14 */
1390 	{xdr_nfslog_createargs, xdr_nfslog_diropres, TRUE},
1391 
1392 	/* RFS_RMDIR = 15 */
1393 	{xdr_nfslog_diropargs, xdr_nfsstat, TRUE},
1394 
1395 	/* RFS_READDIR = 16 */
1396 	{xdr_nfslog_rddirargs, xdr_nfslog_rddirres, TRUE},
1397 
1398 	/* RFS_STATFS = 17 */
1399 	{xdr_fhandle, xdr_nfslog_statfs, FALSE},
1400 };
1401 
1402 
1403 /*
1404  * NFS VERSION 3
1405  */
1406 
1407 static struct nfslog_proc_disp nfslog_proc_v3[] = {
1408 
1409 	/* NFSPROC3_NULL = 0 */
1410 	{xdr_void, xdr_void, FALSE},
1411 
1412 	/* NFSPROC3_GETATTR = 1 */
1413 	{xdr_nfslog_nfs_fh3, xdr_nfslog_GETATTR3res, FALSE},
1414 
1415 	/* NFSPROC3_SETATTR = 2 */
1416 	{xdr_nfslog_SETATTR3args, xdr_nfslog_SETATTR3res, TRUE},
1417 
1418 	/* NFSPROC3_LOOKUP = 3 */
1419 	{xdr_nfslog_diropargs3, xdr_nfslog_LOOKUP3res, TRUE},
1420 
1421 	/* NFSPROC3_ACCESS = 4 */
1422 	{xdr_nfslog_ACCESS3args, xdr_nfslog_ACCESS3res, FALSE},
1423 
1424 	/* NFSPROC3_READLINK = 5 */
1425 	{xdr_nfslog_nfs_fh3, xdr_nfslog_READLINK3res, FALSE},
1426 
1427 	/* NFSPROC3_READ = 6 */
1428 	{xdr_nfslog_READ3args, xdr_nfslog_READ3res, TRUE},
1429 
1430 	/* NFSPROC3_WRITE = 7 */
1431 	{xdr_nfslog_WRITE3args, xdr_nfslog_WRITE3res, TRUE},
1432 
1433 	/* NFSPROC3_CREATE = 8 */
1434 	{xdr_nfslog_CREATE3args, xdr_nfslog_CREATE3res, TRUE},
1435 
1436 	/* NFSPROC3_MKDIR = 9 */
1437 	{xdr_nfslog_MKDIR3args, xdr_nfslog_MKDIR3res, TRUE},
1438 
1439 	/* NFSPROC3_SYMLINK = 10 */
1440 	{xdr_nfslog_SYMLINK3args, xdr_nfslog_SYMLINK3res, TRUE},
1441 
1442 	/* NFSPROC3_MKNOD = 11 */
1443 	{xdr_nfslog_MKNOD3args, xdr_nfslog_MKNOD3res, TRUE},
1444 
1445 	/* NFSPROC3_REMOVE = 12 */
1446 	{xdr_nfslog_REMOVE3args, xdr_nfslog_REMOVE3res, TRUE},
1447 
1448 	/* NFSPROC3_RMDIR = 13 */
1449 	{xdr_nfslog_RMDIR3args, xdr_nfslog_RMDIR3res, TRUE},
1450 
1451 	/* NFSPROC3_RENAME = 14 */
1452 	{xdr_nfslog_RENAME3args, xdr_nfslog_RENAME3res, TRUE},
1453 
1454 	/* NFSPROC3_LINK = 15 */
1455 	{xdr_nfslog_LINK3args, xdr_nfslog_LINK3res, TRUE},
1456 
1457 	/* NFSPROC3_READDIR = 16 */
1458 	{xdr_nfslog_READDIR3args, xdr_nfslog_READDIR3res, TRUE},
1459 
1460 	/* NFSPROC3_READDIRPLUS = 17 */
1461 	{xdr_nfslog_READDIRPLUS3args, xdr_nfslog_READDIRPLUS3res, TRUE},
1462 
1463 	/* NFSPROC3_FSSTAT = 18 */
1464 	{xdr_nfslog_FSSTAT3args, xdr_nfslog_FSSTAT3res, FALSE},
1465 
1466 	/* NFSPROC3_FSINFO = 19 */
1467 	{xdr_nfslog_FSINFO3args, xdr_nfslog_FSINFO3res, FALSE},
1468 
1469 	/* NFSPROC3_PATHCONF = 20 */
1470 	{xdr_nfslog_PATHCONF3args, xdr_nfslog_PATHCONF3res, FALSE},
1471 
1472 	/* NFSPROC3_COMMIT = 21 */
1473 	{xdr_nfslog_COMMIT3args, xdr_nfslog_COMMIT3res, FALSE},
1474 };
1475 
1476 static struct nfslog_proc_disp nfslog_proc_v1[] = {
1477 	/*
1478 	 * NFSLOG VERSION 1
1479 	 */
1480 
1481 	/* NFSLOG_NULL = 0 */
1482 	{xdr_void, xdr_void, TRUE},
1483 
1484 	/* NFSLOG_SHARE = 1 */
1485 	{xdr_nfslog_sharefsargs, xdr_nfslog_sharefsres, TRUE},
1486 
1487 	/* NFSLOG_UNSHARE = 2 */
1488 	{xdr_nfslog_sharefsargs, xdr_nfslog_sharefsres, TRUE},
1489 
1490 	/* NFSLOG_LOOKUP = 3 */
1491 	{xdr_nfslog_diropargs3, xdr_nfslog_LOOKUP3res, TRUE},
1492 
1493 	/* NFSLOG_GETFH = 4 */
1494 	{xdr_nfslog_getfhargs, xdr_nfsstat, TRUE},
1495 };
1496 
1497 static struct nfslog_vers_disp nfslog_vers_disptable[] = {
1498 	{sizeof (nfslog_proc_v2) / sizeof (nfslog_proc_v2[0]),
1499 	    nfslog_proc_v2},
1500 	{sizeof (nfslog_proc_v3) / sizeof (nfslog_proc_v3[0]),
1501 	    nfslog_proc_v3},
1502 };
1503 
1504 static struct nfslog_vers_disp nfslog_nfslog_vers_disptable[] = {
1505 	{sizeof (nfslog_proc_v1) / sizeof (nfslog_proc_v1[0]),
1506 	    nfslog_proc_v1},
1507 };
1508 
1509 static struct nfslog_prog_disp nfslog_dispatch_table[] = {
1510 	{NFS_PROGRAM, NFS_VERSMIN,
1511 		(sizeof (nfslog_vers_disptable) /
1512 		sizeof (nfslog_vers_disptable[0])),
1513 		nfslog_vers_disptable},
1514 
1515 	{NFSLOG_PROGRAM, NFSLOG_VERSMIN,
1516 		(sizeof (nfslog_nfslog_vers_disptable) /
1517 		sizeof (nfslog_nfslog_vers_disptable[0])),
1518 		nfslog_nfslog_vers_disptable},
1519 };
1520 
1521 static int	nfslog_dispatch_table_arglen = sizeof (nfslog_dispatch_table) /
1522 					sizeof (nfslog_dispatch_table[0]);
1523 
1524 /*
1525  * This function will determine the appropriate export info struct to use
1526  * and allocate a record id to be used in the written log buffer.
1527  * Usually this is a straightforward operation but the existence of the
1528  * multicomponent lookup and its semantics of crossing file system
1529  * boundaries add to the complexity.  See the comments below...
1530  */
1531 struct exportinfo *
1532 nfslog_get_exi(
1533 	struct exportinfo *exi,
1534 	struct svc_req *req,
1535 	caddr_t res,
1536 	unsigned int *nfslog_rec_id)
1537 {
1538 	struct log_buffer *lb;
1539 	struct exportinfo *exi_ret = NULL;
1540 	fhandle_t		*fh;
1541 	nfs_fh3			*fh3;
1542 
1543 	if (exi == NULL)
1544 		return (NULL);
1545 
1546 	/*
1547 	 * If the exi is marked for logging, allocate a record id and return
1548 	 */
1549 	if (exi->exi_export.ex_flags & EX_LOG) {
1550 		lb = exi->exi_logbuffer;
1551 
1552 		/* obtain the unique record id for the caller */
1553 		*nfslog_rec_id = atomic_add_32_nv(&lb->lb_rec_id, (int32_t)1);
1554 
1555 		/*
1556 		 * The caller will expect to be able to exi_rele() it,
1557 		 * so exi->exi_count must be incremented before it can
1558 		 * be returned, to make it uniform with exi_ret->exi_count
1559 		 */
1560 		mutex_enter(&exi->exi_lock);
1561 		exi->exi_count++;
1562 		mutex_exit(&exi->exi_lock);
1563 
1564 		return (exi);
1565 	}
1566 
1567 	if (exi != exi_public)
1568 		return (NULL);
1569 
1570 	/*
1571 	 * Here we have an exi that is not marked for logging.
1572 	 * It is possible that this request is a multicomponent lookup
1573 	 * that was done from the public file handle (not logged) and
1574 	 * the resulting file handle being returned to the client exists
1575 	 * in a file system that is being logged.  If this is the case
1576 	 * we need to log this multicomponent lookup to the appropriate
1577 	 * log buffer.  This will allow for the appropriate path name
1578 	 * mapping to occur at user level.
1579 	 */
1580 	if (req->rq_prog == NFS_PROGRAM) {
1581 		switch (req->rq_vers) {
1582 		case NFS_V3:
1583 			if ((req->rq_proc == NFSPROC3_LOOKUP) &&
1584 			    (((LOOKUP3res *)res)->status == NFS3_OK)) {
1585 				fh3 = &((LOOKUP3res *)res)->res_u.ok.object;
1586 				exi_ret = checkexport(&fh3->fh3_fsid,
1587 				    FH3TOXFIDP(fh3));
1588 			}
1589 			break;
1590 
1591 		case NFS_VERSION:
1592 			if ((req->rq_proc == RFS_LOOKUP) &&
1593 			    (((struct nfsdiropres *)
1594 			    res)->dr_status == NFS_OK)) {
1595 				fh =  &((struct nfsdiropres *)res)->
1596 				    dr_u.dr_drok_u.drok_fhandle;
1597 				exi_ret = checkexport(&fh->fh_fsid,
1598 				    (fid_t *)&fh->fh_xlen);
1599 			}
1600 			break;
1601 		default:
1602 			break;
1603 		}
1604 	}
1605 
1606 	if (exi_ret != NULL && exi_ret->exi_export.ex_flags & EX_LOG) {
1607 		lb = exi_ret->exi_logbuffer;
1608 		/* obtain the unique record id for the caller */
1609 		*nfslog_rec_id = atomic_add_32_nv(&lb->lb_rec_id, (int32_t)1);
1610 
1611 		return (exi_ret);
1612 	}
1613 	return (NULL);
1614 }
1615 
1616 #ifdef DEBUG
1617 static long long rfslog_records_ignored = 0;
1618 #endif
1619 
1620 /*
1621  * nfslog_write_record - Fill in the record buffer for writing out.
1622  * If logrecp is null, log it, otherwise, malloc the record and return it.
1623  *
1624  * It is the responsibility of the caller to check whether this exportinfo
1625  * has logging enabled.
1626  * Note that nfslog_share_public_record() only needs to check for the
1627  * existence of at least one logbuffer to which the public filehandle record
1628  * needs to be logged.
1629  */
1630 void
1631 nfslog_write_record(struct exportinfo *exi, struct svc_req *req,
1632 	caddr_t args, caddr_t res, cred_t *cr, struct netbuf *pnb,
1633 	unsigned int record_id, unsigned int which_buffers)
1634 {
1635 	struct nfslog_prog_disp	*progtable;	/* prog struct */
1636 	struct nfslog_vers_disp	*verstable;	/* version struct */
1637 	struct nfslog_proc_disp	*disp = NULL;	/* proc struct */
1638 	int			i, vers;
1639 	void			*log_cookie;	/* for logrecord if */
1640 	caddr_t			buffer;
1641 	XDR			xdrs;
1642 	unsigned int		final_size;
1643 	int			encode_ok;
1644 	int			alloc_indx;
1645 
1646 	ASSERT(exi != NULL); ASSERT(req != NULL); ASSERT(args != NULL);
1647 	ASSERT(res != NULL); ASSERT(cr != NULL);
1648 
1649 	/*
1650 	 * Find program element
1651 	 * Search the list since program can not be used as index
1652 	 */
1653 	for (i = 0; (i < nfslog_dispatch_table_arglen); i++) {
1654 		if (req->rq_prog == nfslog_dispatch_table[i].nfslog_dis_prog)
1655 			break;
1656 	}
1657 	if (i >= nfslog_dispatch_table_arglen) {	/* program not logged */
1658 		/* not an error */
1659 		return;
1660 	}
1661 
1662 	/*
1663 	 * Extract the dispatch functions based on program/version
1664 	 */
1665 	progtable = &nfslog_dispatch_table[i];
1666 	vers = req->rq_vers - progtable->nfslog_dis_versmin;
1667 	verstable = &progtable->nfslog_dis_vers_table[vers];
1668 	disp = &verstable->nfslog_dis_proc_table[req->rq_proc];
1669 
1670 	if (!(exi->exi_export.ex_flags & EX_LOG_ALLOPS) &&
1671 	    !disp->affects_transactions) {
1672 		/*
1673 		 * Only interested in logging operations affecting
1674 		 * transaction generation. This is not one of them.
1675 		 */
1676 #ifdef DEBUG
1677 		rfslog_records_ignored++;
1678 #endif
1679 		return;
1680 	}
1681 
1682 	switch (req->rq_prog) {
1683 	case NFS_PROGRAM:
1684 		switch (req->rq_vers) {
1685 		case NFS_V3:
1686 			switch (req->rq_proc) {
1687 			case NFSPROC3_READDIRPLUS:
1688 				alloc_indx = MEDIUM_INDX;
1689 				break;
1690 			default:
1691 				alloc_indx = SMALL_INDX;
1692 				break;
1693 			}
1694 			break;
1695 		default:
1696 			alloc_indx = SMALL_INDX;
1697 			break;
1698 		}
1699 		break;
1700 	case NFSLOG_PROGRAM:
1701 		alloc_indx = MEDIUM_INDX;
1702 		break;
1703 	default:
1704 		alloc_indx = SMALL_INDX;
1705 		break;
1706 	}
1707 
1708 	do {
1709 		encode_ok = FALSE;
1710 
1711 		/* Pick the size to alloc; end of the road - return */
1712 		if (nfslog_mem_alloc[alloc_indx].size == (-1)) {
1713 			cmn_err(CE_WARN,
1714 			    "NFSLOG: unable to encode record - prog=%d "
1715 			    "proc = %d", req->rq_prog, req->rq_proc);
1716 			return;
1717 		}
1718 
1719 		buffer = nfslog_record_alloc(exi, alloc_indx, &log_cookie, 0);
1720 		if (buffer == NULL) {
1721 			/* Error processing - no space alloced */
1722 			rfs_log_bad++;
1723 			cmn_err(CE_WARN, "NFSLOG: can't get record");
1724 			return;
1725 		}
1726 
1727 		xdrmem_create(&xdrs, buffer,
1728 		    nfslog_mem_alloc[alloc_indx].size, XDR_ENCODE);
1729 
1730 		/*
1731 		 * Encode the header, args and results of the record
1732 		 */
1733 		if (xdr_nfslog_request_record(&xdrs, exi, req, cr, pnb,
1734 		    nfslog_mem_alloc[alloc_indx].size, record_id) &&
1735 		    (*disp->xdrargs)(&xdrs, args) &&
1736 		    (*disp->xdrres)(&xdrs, res)) {
1737 				encode_ok = TRUE;
1738 
1739 				rfs_log_good++;
1740 				/*
1741 				 * Get the final size of the encoded
1742 				 * data and insert that length at the
1743 				 * beginning.
1744 				 */
1745 				final_size = xdr_getpos(&xdrs);
1746 				xdr_setpos(&xdrs, 0);
1747 				(void) xdr_u_int(&xdrs, &final_size);
1748 		} else {
1749 			/* Oops, the encode failed so we need to free memory */
1750 			nfslog_record_put(log_cookie, 0, FALSE, which_buffers);
1751 			alloc_indx++;
1752 		}
1753 
1754 	} while (encode_ok == FALSE);
1755 
1756 
1757 	/*
1758 	 * Take the final log record and put it in the log file.
1759 	 * This may be queued to the file internally and written
1760 	 * later unless the last parameter is TRUE.
1761 	 * If the record_id is 0 then this is most likely a share/unshare
1762 	 * request and it should be written synchronously to the log file.
1763 	 */
1764 	nfslog_record_put(log_cookie,
1765 	    final_size, (record_id == 0), which_buffers);
1766 }
1767 
1768 static char *
1769 get_publicfh_path(int *alloc_length)
1770 {
1771 	extern struct exportinfo *exi_public;
1772 	char *pubpath;
1773 
1774 	rw_enter(&exported_lock, RW_READER);
1775 
1776 	*alloc_length = exi_public->exi_export.ex_pathlen + 1;
1777 	pubpath = kmem_alloc(*alloc_length, KM_SLEEP);
1778 
1779 	(void) strcpy(pubpath, exi_public->exi_export.ex_path);
1780 
1781 	rw_exit(&exported_lock);
1782 
1783 	return (pubpath);
1784 }
1785 
1786 static void
1787 log_public_record(struct exportinfo *exi, cred_t *cr)
1788 {
1789 	struct svc_req	req;
1790 	struct netbuf	nb = {0, 0, NULL};
1791 	int free_length = 0;
1792 	diropargs3 args;
1793 	LOOKUP3res res;
1794 
1795 	bzero(&req, sizeof (req));
1796 	req.rq_prog = NFSLOG_PROGRAM;
1797 	req.rq_vers = NFSLOG_VERSION;
1798 	req.rq_proc = NFSLOG_LOOKUP;
1799 	req.rq_cred.oa_flavor = AUTH_NONE;
1800 
1801 	bzero(&args, sizeof (diropargs3));
1802 	bzero(&res, sizeof (LOOKUP3res));
1803 
1804 	args.dir.fh3_length = 0;
1805 	if ((args.name = get_publicfh_path(&free_length)) == NULL)
1806 		return;
1807 	args.dirp = &args.dir;
1808 
1809 	res.status = NFS3_OK;
1810 	res.res_u.ok.object.fh3_length = 0;
1811 
1812 	/*
1813 	 * Calling this function with the exi_public
1814 	 * will have the effect of appending the record
1815 	 * to each of the open log buffers
1816 	 */
1817 	nfslog_write_record(exi, &req,
1818 	    (caddr_t)&args, (caddr_t)&res, cr, &nb, 0, NFSLOG_ALL_BUFFERS);
1819 
1820 	kmem_free(args.name, free_length);
1821 }
1822 
1823 /*
1824  * nfslog_share_record - logs a share request.
1825  * This is not an NFS request, but we pretend here...
1826  */
1827 void
1828 nfslog_share_record(struct exportinfo *exi, cred_t *cr)
1829 {
1830 	struct svc_req	req;
1831 	int		res = 0;
1832 	struct netbuf	nb = {0, 0, NULL};
1833 
1834 	ASSERT(exi != NULL);
1835 
1836 	if (nfslog_buffer_list == NULL)
1837 		return;
1838 
1839 	if (exi->exi_export.ex_flags & EX_LOG) {
1840 		bzero(&req, sizeof (req));
1841 		req.rq_prog = NFSLOG_PROGRAM;
1842 		req.rq_vers = NFSLOG_VERSION;
1843 		req.rq_proc = NFSLOG_SHARE;
1844 		req.rq_cred.oa_flavor = AUTH_NONE;
1845 		nfslog_write_record(exi, &req, (caddr_t)exi, (caddr_t)&res, cr,
1846 		    &nb, 0, NFSLOG_ONE_BUFFER);
1847 	}
1848 
1849 	log_public_record(exi, cr);
1850 }
1851 
1852 /*
1853  * nfslog_unshare_record - logs an unshare request.
1854  * This is not an NFS request, but we pretend here...
1855  */
1856 void
1857 nfslog_unshare_record(struct exportinfo *exi, cred_t *cr)
1858 {
1859 	struct svc_req	req;
1860 	int		res = 0;
1861 	struct netbuf	nb = {0, 0, NULL};
1862 
1863 	ASSERT(exi != NULL);
1864 	ASSERT(exi->exi_export.ex_flags & EX_LOG);
1865 
1866 	bzero(&req, sizeof (req));
1867 	req.rq_prog = NFSLOG_PROGRAM;
1868 	req.rq_vers = NFSLOG_VERSION;
1869 	req.rq_proc = NFSLOG_UNSHARE;
1870 	req.rq_cred.oa_flavor = AUTH_NONE;
1871 	nfslog_write_record(exi, &req,
1872 	    (caddr_t)exi, (caddr_t)&res, cr, &nb, 0, NFSLOG_ONE_BUFFER);
1873 }
1874 
1875 
1876 void
1877 nfslog_getfh(struct exportinfo *exi,
1878 	fhandle *fh,
1879 	char *fname,
1880 	enum uio_seg seg,
1881 	cred_t *cr)
1882 {
1883 	struct svc_req	req;
1884 	int		res = 0;
1885 	struct netbuf	nb = {0, 0, NULL};
1886 	int		error = 0;
1887 	char		*namebuf;
1888 	size_t		len;
1889 	nfslog_getfhargs gfh;
1890 
1891 	ASSERT(exi != NULL);
1892 	ASSERT(exi->exi_export.ex_flags & EX_LOG);
1893 
1894 	bzero(&req, sizeof (req));
1895 	req.rq_prog = NFSLOG_PROGRAM;
1896 	req.rq_vers = NFSLOG_VERSION;
1897 	req.rq_proc = NFSLOG_GETFH;
1898 	req.rq_cred.oa_flavor = AUTH_NONE;
1899 
1900 	namebuf = kmem_alloc(MAXPATHLEN + 4, KM_SLEEP);
1901 	if (seg == UIO_USERSPACE) {
1902 		error = copyinstr(fname, namebuf, MAXPATHLEN, &len);
1903 	} else {
1904 		error = copystr(fname, namebuf, MAXPATHLEN, &len);
1905 	}
1906 
1907 	if (!error) {
1908 		gfh.gfh_fh_buf = *fh;
1909 		gfh.gfh_path = namebuf;
1910 
1911 		nfslog_write_record(exi, &req, (caddr_t)&gfh, (caddr_t)&res,
1912 		    cr, &nb, 0, NFSLOG_ONE_BUFFER);
1913 	}
1914 	kmem_free(namebuf, MAXPATHLEN + 4);
1915 }
1916