xref: /dflybsd-src/sys/vfs/hammer/hammer_vfsops.c (revision 1f07f68660b83c5d87d56552b65ddc489b520a53)
1 /*
2  * Copyright (c) 2007-2008 The DragonFly Project.  All rights reserved.
3  *
4  * This code is derived from software contributed to The DragonFly Project
5  * by Matthew Dillon <dillon@backplane.com>
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  *
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in
15  *    the documentation and/or other materials provided with the
16  *    distribution.
17  * 3. Neither the name of The DragonFly Project nor the names of its
18  *    contributors may be used to endorse or promote products derived
19  *    from this software without specific, prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  * $DragonFly: src/sys/vfs/hammer/hammer_vfsops.c,v 1.31 2008/05/02 01:00:42 dillon Exp $
35  */
36 
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/kernel.h>
40 #include <sys/vnode.h>
41 #include <sys/mount.h>
42 #include <sys/malloc.h>
43 #include <sys/nlookup.h>
44 #include <sys/fcntl.h>
45 #include <sys/sysctl.h>
46 #include <sys/buf.h>
47 #include <sys/buf2.h>
48 #include "hammer.h"
49 
50 int hammer_debug_general;
51 int hammer_debug_locks;
52 int hammer_debug_btree;
53 int hammer_debug_tid;
54 int hammer_debug_recover;	/* -1 will disable, +1 will force */
55 int hammer_debug_recover_faults;
56 int hammer_count_inodes;
57 int hammer_count_records;
58 int hammer_count_record_datas;
59 int hammer_count_volumes;
60 int hammer_count_buffers;
61 int hammer_count_nodes;
62 int hammer_count_dirtybufs;		/* global */
63 int hammer_limit_dirtybufs = 100;	/* per-mount */
64 int hammer_bio_count;
65 int64_t hammer_contention_count;
66 int64_t hammer_zone_limit;
67 
68 SYSCTL_NODE(_vfs, OID_AUTO, hammer, CTLFLAG_RW, 0, "HAMMER filesystem");
69 SYSCTL_INT(_vfs_hammer, OID_AUTO, debug_general, CTLFLAG_RW,
70 	   &hammer_debug_general, 0, "");
71 SYSCTL_INT(_vfs_hammer, OID_AUTO, debug_locks, CTLFLAG_RW,
72 	   &hammer_debug_locks, 0, "");
73 SYSCTL_INT(_vfs_hammer, OID_AUTO, debug_btree, CTLFLAG_RW,
74 	   &hammer_debug_btree, 0, "");
75 SYSCTL_INT(_vfs_hammer, OID_AUTO, debug_tid, CTLFLAG_RW,
76 	   &hammer_debug_tid, 0, "");
77 SYSCTL_INT(_vfs_hammer, OID_AUTO, debug_recover, CTLFLAG_RW,
78 	   &hammer_debug_recover, 0, "");
79 SYSCTL_INT(_vfs_hammer, OID_AUTO, debug_recover_faults, CTLFLAG_RW,
80 	   &hammer_debug_recover_faults, 0, "");
81 
82 SYSCTL_INT(_vfs_hammer, OID_AUTO, limit_dirtybufs, CTLFLAG_RW,
83 	   &hammer_limit_dirtybufs, 0, "");
84 
85 SYSCTL_INT(_vfs_hammer, OID_AUTO, count_inodes, CTLFLAG_RD,
86 	   &hammer_count_inodes, 0, "");
87 SYSCTL_INT(_vfs_hammer, OID_AUTO, count_records, CTLFLAG_RD,
88 	   &hammer_count_records, 0, "");
89 SYSCTL_INT(_vfs_hammer, OID_AUTO, count_record_datas, CTLFLAG_RD,
90 	   &hammer_count_record_datas, 0, "");
91 SYSCTL_INT(_vfs_hammer, OID_AUTO, count_volumes, CTLFLAG_RD,
92 	   &hammer_count_volumes, 0, "");
93 SYSCTL_INT(_vfs_hammer, OID_AUTO, count_buffers, CTLFLAG_RD,
94 	   &hammer_count_buffers, 0, "");
95 SYSCTL_INT(_vfs_hammer, OID_AUTO, count_nodes, CTLFLAG_RD,
96 	   &hammer_count_nodes, 0, "");
97 SYSCTL_INT(_vfs_hammer, OID_AUTO, count_dirtybufs, CTLFLAG_RD,
98 	   &hammer_count_dirtybufs, 0, "");
99 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, zone_limit, CTLFLAG_RW,
100 	   &hammer_zone_limit, 0, "");
101 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, contention_count, CTLFLAG_RW,
102 	   &hammer_contention_count, 0, "");
103 
104 /*
105  * VFS ABI
106  */
107 static void	hammer_free_hmp(struct mount *mp);
108 
109 static int	hammer_vfs_mount(struct mount *mp, char *path, caddr_t data,
110 				struct ucred *cred);
111 static int	hammer_vfs_unmount(struct mount *mp, int mntflags);
112 static int	hammer_vfs_root(struct mount *mp, struct vnode **vpp);
113 static int	hammer_vfs_statfs(struct mount *mp, struct statfs *sbp,
114 				struct ucred *cred);
115 static int	hammer_vfs_sync(struct mount *mp, int waitfor);
116 static int	hammer_vfs_vget(struct mount *mp, ino_t ino,
117 				struct vnode **vpp);
118 static int	hammer_vfs_init(struct vfsconf *conf);
119 static int	hammer_vfs_fhtovp(struct mount *mp, struct fid *fhp,
120 				struct vnode **vpp);
121 static int	hammer_vfs_vptofh(struct vnode *vp, struct fid *fhp);
122 static int	hammer_vfs_checkexp(struct mount *mp, struct sockaddr *nam,
123 				int *exflagsp, struct ucred **credanonp);
124 
125 
126 static struct vfsops hammer_vfsops = {
127 	.vfs_mount	= hammer_vfs_mount,
128 	.vfs_unmount	= hammer_vfs_unmount,
129 	.vfs_root 	= hammer_vfs_root,
130 	.vfs_statfs	= hammer_vfs_statfs,
131 	.vfs_sync	= hammer_vfs_sync,
132 	.vfs_vget	= hammer_vfs_vget,
133 	.vfs_init	= hammer_vfs_init,
134 	.vfs_vptofh	= hammer_vfs_vptofh,
135 	.vfs_fhtovp	= hammer_vfs_fhtovp,
136 	.vfs_checkexp	= hammer_vfs_checkexp
137 };
138 
139 MALLOC_DEFINE(M_HAMMER, "hammer-mount", "hammer mount");
140 
141 VFS_SET(hammer_vfsops, hammer, 0);
142 MODULE_VERSION(hammer, 1);
143 
144 static int
145 hammer_vfs_init(struct vfsconf *conf)
146 {
147 	/*hammer_init_alist_config();*/
148 	return(0);
149 }
150 
151 static int
152 hammer_vfs_mount(struct mount *mp, char *mntpt, caddr_t data,
153 		 struct ucred *cred)
154 {
155 	struct hammer_mount_info info;
156 	hammer_mount_t hmp;
157 	hammer_volume_t rootvol;
158 	struct vnode *rootvp;
159 	const char *upath;	/* volume name in userspace */
160 	char *path;		/* volume name in system space */
161 	int error;
162 	int i;
163 
164 	if ((error = copyin(data, &info, sizeof(info))) != 0)
165 		return (error);
166 	if (info.nvolumes <= 0 || info.nvolumes >= 32768)
167 		return (EINVAL);
168 
169 	/*
170 	 * Interal mount data structure
171 	 */
172 	if (mp->mnt_flag & MNT_UPDATE) {
173 		hmp = (void *)mp->mnt_data;
174 		KKASSERT(hmp != NULL);
175 	} else {
176 		hmp = kmalloc(sizeof(*hmp), M_HAMMER, M_WAITOK | M_ZERO);
177 		mp->mnt_data = (qaddr_t)hmp;
178 		hmp->mp = mp;
179 		hmp->zbuf = kmalloc(HAMMER_BUFSIZE, M_HAMMER, M_WAITOK|M_ZERO);
180 		hmp->namekey_iterator = mycpu->gd_time_seconds;
181 		/*TAILQ_INIT(&hmp->recycle_list);*/
182 
183 		hmp->root_btree_beg.obj_id = -0x8000000000000000LL;
184 		hmp->root_btree_beg.key = -0x8000000000000000LL;
185 		hmp->root_btree_beg.create_tid = 1;
186 		hmp->root_btree_beg.delete_tid = 1;
187 		hmp->root_btree_beg.rec_type = 0;
188 		hmp->root_btree_beg.obj_type = 0;
189 
190 		hmp->root_btree_end.obj_id = 0x7FFFFFFFFFFFFFFFLL;
191 		hmp->root_btree_end.key = 0x7FFFFFFFFFFFFFFFLL;
192 		hmp->root_btree_end.create_tid = 0xFFFFFFFFFFFFFFFFULL;
193 		hmp->root_btree_end.delete_tid = 0;   /* special case */
194 		hmp->root_btree_end.rec_type = 0xFFFFU;
195 		hmp->root_btree_end.obj_type = 0;
196 		lockinit(&hmp->blockmap_lock, "blkmap", 0, 0);
197 
198 		hmp->sync_lock.refs = 1;
199 
200 		TAILQ_INIT(&hmp->flush_list);
201 		TAILQ_INIT(&hmp->objid_cache_list);
202 
203 		/*
204 		 * Set default zone limits.  This value can be reduced
205 		 * further by the zone limit specified in the root volume.
206 		 *
207 		 * The sysctl can force a small zone limit for debugging
208 		 * purposes.
209 		 */
210 		for (i = 0; i < HAMMER_MAX_ZONES; ++i) {
211 			hmp->zone_limits[i] =
212 				HAMMER_ZONE_ENCODE(i, HAMMER_ZONE_LIMIT);
213 
214 			if (hammer_zone_limit) {
215 				hmp->zone_limits[i] =
216 				    HAMMER_ZONE_ENCODE(i, hammer_zone_limit);
217 			}
218 			hammer_init_holes(hmp, &hmp->holes[i]);
219 		}
220 	}
221 	hmp->hflags = info.hflags;
222 	if (info.asof) {
223 		mp->mnt_flag |= MNT_RDONLY;
224 		hmp->asof = info.asof;
225 	} else {
226 		hmp->asof = HAMMER_MAX_TID;
227 	}
228 
229 	/*
230 	 * Re-open read-write if originally read-only, or vise-versa XXX
231 	 */
232 	if (mp->mnt_flag & MNT_UPDATE) {
233 		if (hmp->ronly == 0 && (mp->mnt_flag & MNT_RDONLY)) {
234 			kprintf("HAMMER read-write -> read-only XXX\n");
235 			hmp->ronly = 1;
236 		} else if (hmp->ronly && (mp->mnt_flag & MNT_RDONLY) == 0) {
237 			kprintf("HAMMER read-only -> read-write XXX\n");
238 			hmp->ronly = 0;
239 		}
240 		return(0);
241 	}
242 
243 	RB_INIT(&hmp->rb_vols_root);
244 	RB_INIT(&hmp->rb_inos_root);
245 	RB_INIT(&hmp->rb_nods_root);
246 	hmp->ronly = ((mp->mnt_flag & MNT_RDONLY) != 0);
247 
248 	TAILQ_INIT(&hmp->volu_list);
249 	TAILQ_INIT(&hmp->undo_list);
250 	TAILQ_INIT(&hmp->data_list);
251 	TAILQ_INIT(&hmp->meta_list);
252 	TAILQ_INIT(&hmp->lose_list);
253 
254 	/*
255 	 * Load volumes
256 	 */
257 	path = objcache_get(namei_oc, M_WAITOK);
258 	hmp->nvolumes = info.nvolumes;
259 	for (i = 0; i < info.nvolumes; ++i) {
260 		error = copyin(&info.volumes[i], &upath, sizeof(char *));
261 		if (error == 0)
262 			error = copyinstr(upath, path, MAXPATHLEN, NULL);
263 		if (error == 0)
264 			error = hammer_install_volume(hmp, path);
265 		if (error)
266 			break;
267 	}
268 	objcache_put(namei_oc, path);
269 
270 	/*
271 	 * Make sure we found a root volume
272 	 */
273 	if (error == 0 && hmp->rootvol == NULL) {
274 		kprintf("hammer_mount: No root volume found!\n");
275 		error = EINVAL;
276 	}
277 	if (error) {
278 		hammer_free_hmp(mp);
279 		return (error);
280 	}
281 
282 	/*
283 	 * No errors, setup enough of the mount point so we can lookup the
284 	 * root vnode.
285 	 */
286 	mp->mnt_iosize_max = MAXPHYS;
287 	mp->mnt_kern_flag |= MNTK_FSMID;
288 
289 	/*
290 	 * note: f_iosize is used by vnode_pager_haspage() when constructing
291 	 * its VOP_BMAP call.
292 	 */
293 	mp->mnt_stat.f_iosize = HAMMER_BUFSIZE;
294 	mp->mnt_stat.f_bsize = HAMMER_BUFSIZE;
295 	mp->mnt_maxsymlinklen = 255;
296 	mp->mnt_flag |= MNT_LOCAL;
297 
298 	vfs_add_vnodeops(mp, &hammer_vnode_vops, &mp->mnt_vn_norm_ops);
299 	vfs_add_vnodeops(mp, &hammer_spec_vops, &mp->mnt_vn_spec_ops);
300 	vfs_add_vnodeops(mp, &hammer_fifo_vops, &mp->mnt_vn_fifo_ops);
301 
302 	/*
303 	 * The root volume's ondisk pointer is only valid if we hold a
304 	 * reference to it.
305 	 */
306 	rootvol = hammer_get_root_volume(hmp, &error);
307 	if (error)
308 		goto failed;
309 
310 	/*
311 	 * Perform any necessary UNDO operations.  The recover code does
312 	 * call hammer_undo_lookup() so we have to pre-cache the blockmap,
313 	 * and then re-copy it again after recovery is complete.
314 	 */
315 	bcopy(rootvol->ondisk->vol0_blockmap, hmp->blockmap,
316 	      sizeof(hmp->blockmap));
317 	error = hammer_recover(hmp, rootvol);
318 	if (error) {
319 		kprintf("Failed to recover HAMMER filesystem on mount\n");
320 		goto done;
321 	}
322 
323 	/*
324 	 * Finish setup now that we have a good root volume
325 	 */
326 	ksnprintf(mp->mnt_stat.f_mntfromname,
327 		  sizeof(mp->mnt_stat.f_mntfromname), "%s",
328 		  rootvol->ondisk->vol_name);
329 	mp->mnt_stat.f_fsid.val[0] =
330 		crc32((char *)&rootvol->ondisk->vol_fsid + 0, 8);
331 	mp->mnt_stat.f_fsid.val[1] =
332 		crc32((char *)&rootvol->ondisk->vol_fsid + 8, 8);
333 
334 	/*
335 	 * Certain often-modified fields in the root volume are cached in
336 	 * the hammer_mount structure so we do not have to generate lots
337 	 * of little UNDO structures for them.
338 	 */
339 	hmp->next_tid = rootvol->ondisk->vol0_next_tid;
340 	bcopy(rootvol->ondisk->vol0_blockmap, hmp->blockmap,
341 	      sizeof(hmp->blockmap));
342 
343 	/*
344 	 * Use the zone limit set by newfs_hammer, or the zone limit set by
345 	 * sysctl (for debugging), whichever is smaller.
346 	 */
347 	if (rootvol->ondisk->vol0_zone_limit) {
348 		hammer_off_t vol0_zone_limit;
349 
350 		vol0_zone_limit = rootvol->ondisk->vol0_zone_limit;
351 		for (i = 0; i < HAMMER_MAX_ZONES; ++i) {
352 			if (hmp->zone_limits[i] > vol0_zone_limit)
353 				hmp->zone_limits[i] = vol0_zone_limit;
354 		}
355 	}
356 
357 	hammer_flusher_create(hmp);
358 
359 	/*
360 	 * Locate the root directory using the root cluster's B-Tree as a
361 	 * starting point.  The root directory uses an obj_id of 1.
362 	 *
363 	 * FUTURE: Leave the root directory cached referenced but unlocked
364 	 * in hmp->rootvp (need to flush it on unmount).
365 	 */
366 	error = hammer_vfs_vget(mp, 1, &rootvp);
367 	if (error)
368 		goto done;
369 	vput(rootvp);
370 	/*vn_unlock(hmp->rootvp);*/
371 
372 done:
373 	hammer_rel_volume(rootvol, 0);
374 failed:
375 	/*
376 	 * Cleanup and return.
377 	 */
378 	if (error)
379 		hammer_free_hmp(mp);
380 	return (error);
381 }
382 
383 static int
384 hammer_vfs_unmount(struct mount *mp, int mntflags)
385 {
386 #if 0
387 	struct hammer_mount *hmp = (void *)mp->mnt_data;
388 #endif
389 	int flags;
390 	int error;
391 
392 	/*
393 	 * Clean out the vnodes
394 	 */
395 	flags = 0;
396 	if (mntflags & MNT_FORCE)
397 		flags |= FORCECLOSE;
398 	if ((error = vflush(mp, 0, flags)) != 0)
399 		return (error);
400 
401 	/*
402 	 * Clean up the internal mount structure and related entities.  This
403 	 * may issue I/O.
404 	 */
405 	hammer_free_hmp(mp);
406 	return(0);
407 }
408 
409 /*
410  * Clean up the internal mount structure and disassociate it from the mount.
411  * This may issue I/O.
412  */
413 static void
414 hammer_free_hmp(struct mount *mp)
415 {
416 	struct hammer_mount *hmp = (void *)mp->mnt_data;
417 	int i;
418 
419 #if 0
420 	/*
421 	 * Clean up the root vnode
422 	 */
423 	if (hmp->rootvp) {
424 		vrele(hmp->rootvp);
425 		hmp->rootvp = NULL;
426 	}
427 #endif
428 	hammer_flusher_sync(hmp);
429 	hammer_flusher_sync(hmp);
430 	hammer_flusher_destroy(hmp);
431 
432 	KKASSERT(RB_EMPTY(&hmp->rb_inos_root));
433 
434 #if 0
435 	/*
436 	 * Unload & flush inodes
437 	 *
438 	 * XXX illegal to call this from here, it can only be done from
439 	 * the flusher.
440 	 */
441 	RB_SCAN(hammer_ino_rb_tree, &hmp->rb_inos_root, NULL,
442 		hammer_unload_inode, (void *)MNT_WAIT);
443 
444 	/*
445 	 * Unload & flush volumes
446 	 */
447 #endif
448 	/*
449 	 * Unload the volumes
450 	 */
451 	RB_SCAN(hammer_vol_rb_tree, &hmp->rb_vols_root, NULL,
452 		hammer_unload_volume, NULL);
453 
454 	mp->mnt_data = NULL;
455 	mp->mnt_flag &= ~MNT_LOCAL;
456 	hmp->mp = NULL;
457 	hammer_destroy_objid_cache(hmp);
458 	kfree(hmp->zbuf, M_HAMMER);
459 	lockuninit(&hmp->blockmap_lock);
460 
461 	for (i = 0; i < HAMMER_MAX_ZONES; ++i)
462 		hammer_free_holes(hmp, &hmp->holes[i]);
463 
464 	kfree(hmp, M_HAMMER);
465 }
466 
467 /*
468  * Obtain a vnode for the specified inode number.  An exclusively locked
469  * vnode is returned.
470  */
471 int
472 hammer_vfs_vget(struct mount *mp, ino_t ino, struct vnode **vpp)
473 {
474 	struct hammer_transaction trans;
475 	struct hammer_mount *hmp = (void *)mp->mnt_data;
476 	struct hammer_inode *ip;
477 	int error;
478 
479 	hammer_simple_transaction(&trans, hmp);
480 
481 	/*
482 	 * Lookup the requested HAMMER inode.  The structure must be
483 	 * left unlocked while we manipulate the related vnode to avoid
484 	 * a deadlock.
485 	 */
486 	ip = hammer_get_inode(&trans, NULL, ino, hmp->asof, 0, &error);
487 	if (ip == NULL) {
488 		*vpp = NULL;
489 		return(error);
490 	}
491 	error = hammer_get_vnode(ip, LK_EXCLUSIVE, vpp);
492 	hammer_rel_inode(ip, 0);
493 	hammer_done_transaction(&trans);
494 	return (error);
495 }
496 
497 /*
498  * Return the root vnode for the filesystem.
499  *
500  * HAMMER stores the root vnode in the hammer_mount structure so
501  * getting it is easy.
502  */
503 static int
504 hammer_vfs_root(struct mount *mp, struct vnode **vpp)
505 {
506 #if 0
507 	struct hammer_mount *hmp = (void *)mp->mnt_data;
508 #endif
509 	int error;
510 
511 	error = hammer_vfs_vget(mp, 1, vpp);
512 	return (error);
513 }
514 
515 static int
516 hammer_vfs_statfs(struct mount *mp, struct statfs *sbp, struct ucred *cred)
517 {
518 	struct hammer_mount *hmp = (void *)mp->mnt_data;
519 	hammer_volume_t volume;
520 	hammer_volume_ondisk_t ondisk;
521 	int error;
522 	int64_t bfree;
523 
524 	volume = hammer_get_root_volume(hmp, &error);
525 	if (error)
526 		return(error);
527 	ondisk = volume->ondisk;
528 
529 	/*
530 	 * Basic stats
531 	 */
532 	mp->mnt_stat.f_files = ondisk->vol0_stat_inodes;
533 	bfree = ondisk->vol0_stat_freebigblocks * HAMMER_LARGEBLOCK_SIZE;
534 	hammer_rel_volume(volume, 0);
535 
536 	mp->mnt_stat.f_bfree = bfree / HAMMER_BUFSIZE;
537 	mp->mnt_stat.f_bavail = mp->mnt_stat.f_bfree;
538 	if (mp->mnt_stat.f_files < 0)
539 		mp->mnt_stat.f_files = 0;
540 
541 	*sbp = mp->mnt_stat;
542 	return(0);
543 }
544 
545 /*
546  * Sync the filesystem.  Currently we have to run it twice, the second
547  * one will advance the undo start index to the end index, so if a crash
548  * occurs no undos will be run on mount.
549  */
550 static int
551 hammer_vfs_sync(struct mount *mp, int waitfor)
552 {
553 	struct hammer_mount *hmp = (void *)mp->mnt_data;
554 	int error;
555 
556 	error = hammer_sync_hmp(hmp, waitfor);
557 	if (error == 0)
558 		error = hammer_sync_hmp(hmp, waitfor);
559 	return (error);
560 }
561 
562 /*
563  * Convert a vnode to a file handle.
564  */
565 static int
566 hammer_vfs_vptofh(struct vnode *vp, struct fid *fhp)
567 {
568 	hammer_inode_t ip;
569 
570 	KKASSERT(MAXFIDSZ >= 16);
571 	ip = VTOI(vp);
572 	fhp->fid_len = offsetof(struct fid, fid_data[16]);
573 	fhp->fid_reserved = 0;
574 	bcopy(&ip->obj_id, fhp->fid_data + 0, sizeof(ip->obj_id));
575 	bcopy(&ip->obj_asof, fhp->fid_data + 8, sizeof(ip->obj_asof));
576 	return(0);
577 }
578 
579 
580 /*
581  * Convert a file handle back to a vnode.
582  */
583 static int
584 hammer_vfs_fhtovp(struct mount *mp, struct fid *fhp, struct vnode **vpp)
585 {
586 	struct hammer_transaction trans;
587 	struct hammer_inode *ip;
588 	struct hammer_inode_info info;
589 	int error;
590 
591 	bcopy(fhp->fid_data + 0, &info.obj_id, sizeof(info.obj_id));
592 	bcopy(fhp->fid_data + 8, &info.obj_asof, sizeof(info.obj_asof));
593 
594 	hammer_simple_transaction(&trans, (void *)mp->mnt_data);
595 
596 	/*
597 	 * Get/allocate the hammer_inode structure.  The structure must be
598 	 * unlocked while we manipulate the related vnode to avoid a
599 	 * deadlock.
600 	 */
601 	ip = hammer_get_inode(&trans, NULL, info.obj_id, info.obj_asof,
602 			      0, &error);
603 	if (ip == NULL) {
604 		*vpp = NULL;
605 		return(error);
606 	}
607 	error = hammer_get_vnode(ip, LK_EXCLUSIVE, vpp);
608 	hammer_rel_inode(ip, 0);
609 	hammer_done_transaction(&trans);
610 	return (error);
611 }
612 
613 static int
614 hammer_vfs_checkexp(struct mount *mp, struct sockaddr *nam,
615 		    int *exflagsp, struct ucred **credanonp)
616 {
617 	hammer_mount_t hmp = (void *)mp->mnt_data;
618 	struct netcred *np;
619 	int error;
620 
621 	np = vfs_export_lookup(mp, &hmp->export, nam);
622 	if (np) {
623 		*exflagsp = np->netc_exflags;
624 		*credanonp = &np->netc_anon;
625 		error = 0;
626 	} else {
627 		error = EACCES;
628 	}
629 	return (error);
630 
631 }
632 
633 int
634 hammer_vfs_export(struct mount *mp, int op, const struct export_args *export)
635 {
636 	hammer_mount_t hmp = (void *)mp->mnt_data;
637 	int error;
638 
639 	switch(op) {
640 	case MOUNTCTL_SET_EXPORT:
641 		error = vfs_export(mp, &hmp->export, export);
642 		break;
643 	default:
644 		error = EOPNOTSUPP;
645 		break;
646 	}
647 	return(error);
648 }
649 
650