xref: /dflybsd-src/sys/vfs/hammer/hammer_vfsops.c (revision e8599db1ae18c0997db98e0ae59d5bd26d01a53c)
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 1.32 2008/05/03 20:21:20 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_inode;
52 int hammer_debug_locks;
53 int hammer_debug_btree;
54 int hammer_debug_tid;
55 int hammer_debug_recover;	/* -1 will disable, +1 will force */
56 int hammer_debug_recover_faults;
57 int hammer_count_inodes;
58 int hammer_count_records;
59 int hammer_count_record_datas;
60 int hammer_count_volumes;
61 int hammer_count_buffers;
62 int hammer_count_nodes;
63 int hammer_count_dirtybufs;		/* global */
64 int hammer_limit_dirtybufs = 100;	/* per-mount */
65 int hammer_bio_count;
66 int64_t hammer_contention_count;
67 int64_t hammer_zone_limit;
68 
69 SYSCTL_NODE(_vfs, OID_AUTO, hammer, CTLFLAG_RW, 0, "HAMMER filesystem");
70 SYSCTL_INT(_vfs_hammer, OID_AUTO, debug_general, CTLFLAG_RW,
71 	   &hammer_debug_general, 0, "");
72 SYSCTL_INT(_vfs_hammer, OID_AUTO, debug_inode, CTLFLAG_RW,
73 	   &hammer_debug_inode, 0, "");
74 SYSCTL_INT(_vfs_hammer, OID_AUTO, debug_locks, CTLFLAG_RW,
75 	   &hammer_debug_locks, 0, "");
76 SYSCTL_INT(_vfs_hammer, OID_AUTO, debug_btree, CTLFLAG_RW,
77 	   &hammer_debug_btree, 0, "");
78 SYSCTL_INT(_vfs_hammer, OID_AUTO, debug_tid, CTLFLAG_RW,
79 	   &hammer_debug_tid, 0, "");
80 SYSCTL_INT(_vfs_hammer, OID_AUTO, debug_recover, CTLFLAG_RW,
81 	   &hammer_debug_recover, 0, "");
82 SYSCTL_INT(_vfs_hammer, OID_AUTO, debug_recover_faults, CTLFLAG_RW,
83 	   &hammer_debug_recover_faults, 0, "");
84 
85 SYSCTL_INT(_vfs_hammer, OID_AUTO, limit_dirtybufs, CTLFLAG_RW,
86 	   &hammer_limit_dirtybufs, 0, "");
87 
88 SYSCTL_INT(_vfs_hammer, OID_AUTO, count_inodes, CTLFLAG_RD,
89 	   &hammer_count_inodes, 0, "");
90 SYSCTL_INT(_vfs_hammer, OID_AUTO, count_records, CTLFLAG_RD,
91 	   &hammer_count_records, 0, "");
92 SYSCTL_INT(_vfs_hammer, OID_AUTO, count_record_datas, CTLFLAG_RD,
93 	   &hammer_count_record_datas, 0, "");
94 SYSCTL_INT(_vfs_hammer, OID_AUTO, count_volumes, CTLFLAG_RD,
95 	   &hammer_count_volumes, 0, "");
96 SYSCTL_INT(_vfs_hammer, OID_AUTO, count_buffers, CTLFLAG_RD,
97 	   &hammer_count_buffers, 0, "");
98 SYSCTL_INT(_vfs_hammer, OID_AUTO, count_nodes, CTLFLAG_RD,
99 	   &hammer_count_nodes, 0, "");
100 SYSCTL_INT(_vfs_hammer, OID_AUTO, count_dirtybufs, CTLFLAG_RD,
101 	   &hammer_count_dirtybufs, 0, "");
102 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, zone_limit, CTLFLAG_RW,
103 	   &hammer_zone_limit, 0, "");
104 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, contention_count, CTLFLAG_RW,
105 	   &hammer_contention_count, 0, "");
106 
107 /*
108  * VFS ABI
109  */
110 static void	hammer_free_hmp(struct mount *mp);
111 
112 static int	hammer_vfs_mount(struct mount *mp, char *path, caddr_t data,
113 				struct ucred *cred);
114 static int	hammer_vfs_unmount(struct mount *mp, int mntflags);
115 static int	hammer_vfs_root(struct mount *mp, struct vnode **vpp);
116 static int	hammer_vfs_statfs(struct mount *mp, struct statfs *sbp,
117 				struct ucred *cred);
118 static int	hammer_vfs_sync(struct mount *mp, int waitfor);
119 static int	hammer_vfs_vget(struct mount *mp, ino_t ino,
120 				struct vnode **vpp);
121 static int	hammer_vfs_init(struct vfsconf *conf);
122 static int	hammer_vfs_fhtovp(struct mount *mp, struct fid *fhp,
123 				struct vnode **vpp);
124 static int	hammer_vfs_vptofh(struct vnode *vp, struct fid *fhp);
125 static int	hammer_vfs_checkexp(struct mount *mp, struct sockaddr *nam,
126 				int *exflagsp, struct ucred **credanonp);
127 
128 
129 static struct vfsops hammer_vfsops = {
130 	.vfs_mount	= hammer_vfs_mount,
131 	.vfs_unmount	= hammer_vfs_unmount,
132 	.vfs_root 	= hammer_vfs_root,
133 	.vfs_statfs	= hammer_vfs_statfs,
134 	.vfs_sync	= hammer_vfs_sync,
135 	.vfs_vget	= hammer_vfs_vget,
136 	.vfs_init	= hammer_vfs_init,
137 	.vfs_vptofh	= hammer_vfs_vptofh,
138 	.vfs_fhtovp	= hammer_vfs_fhtovp,
139 	.vfs_checkexp	= hammer_vfs_checkexp
140 };
141 
142 MALLOC_DEFINE(M_HAMMER, "hammer-mount", "hammer mount");
143 
144 VFS_SET(hammer_vfsops, hammer, 0);
145 MODULE_VERSION(hammer, 1);
146 
147 static int
148 hammer_vfs_init(struct vfsconf *conf)
149 {
150 	/*hammer_init_alist_config();*/
151 	return(0);
152 }
153 
154 static int
155 hammer_vfs_mount(struct mount *mp, char *mntpt, caddr_t data,
156 		 struct ucred *cred)
157 {
158 	struct hammer_mount_info info;
159 	hammer_mount_t hmp;
160 	hammer_volume_t rootvol;
161 	struct vnode *rootvp;
162 	const char *upath;	/* volume name in userspace */
163 	char *path;		/* volume name in system space */
164 	int error;
165 	int i;
166 
167 	if ((error = copyin(data, &info, sizeof(info))) != 0)
168 		return (error);
169 	if (info.nvolumes <= 0 || info.nvolumes >= 32768)
170 		return (EINVAL);
171 
172 	/*
173 	 * Interal mount data structure
174 	 */
175 	if (mp->mnt_flag & MNT_UPDATE) {
176 		hmp = (void *)mp->mnt_data;
177 		KKASSERT(hmp != NULL);
178 	} else {
179 		hmp = kmalloc(sizeof(*hmp), M_HAMMER, M_WAITOK | M_ZERO);
180 		mp->mnt_data = (qaddr_t)hmp;
181 		hmp->mp = mp;
182 		hmp->zbuf = kmalloc(HAMMER_BUFSIZE, M_HAMMER, M_WAITOK|M_ZERO);
183 		hmp->namekey_iterator = mycpu->gd_time_seconds;
184 		/*TAILQ_INIT(&hmp->recycle_list);*/
185 
186 		hmp->root_btree_beg.obj_id = -0x8000000000000000LL;
187 		hmp->root_btree_beg.key = -0x8000000000000000LL;
188 		hmp->root_btree_beg.create_tid = 1;
189 		hmp->root_btree_beg.delete_tid = 1;
190 		hmp->root_btree_beg.rec_type = 0;
191 		hmp->root_btree_beg.obj_type = 0;
192 
193 		hmp->root_btree_end.obj_id = 0x7FFFFFFFFFFFFFFFLL;
194 		hmp->root_btree_end.key = 0x7FFFFFFFFFFFFFFFLL;
195 		hmp->root_btree_end.create_tid = 0xFFFFFFFFFFFFFFFFULL;
196 		hmp->root_btree_end.delete_tid = 0;   /* special case */
197 		hmp->root_btree_end.rec_type = 0xFFFFU;
198 		hmp->root_btree_end.obj_type = 0;
199 		lockinit(&hmp->blockmap_lock, "blkmap", 0, 0);
200 
201 		hmp->sync_lock.refs = 1;
202 
203 		TAILQ_INIT(&hmp->flush_list);
204 		TAILQ_INIT(&hmp->objid_cache_list);
205 		TAILQ_INIT(&hmp->undo_lru_list);
206 
207 		/*
208 		 * Set default zone limits.  This value can be reduced
209 		 * further by the zone limit specified in the root volume.
210 		 *
211 		 * The sysctl can force a small zone limit for debugging
212 		 * purposes.
213 		 */
214 		for (i = 0; i < HAMMER_MAX_ZONES; ++i) {
215 			hmp->zone_limits[i] =
216 				HAMMER_ZONE_ENCODE(i, HAMMER_ZONE_LIMIT);
217 
218 			if (hammer_zone_limit) {
219 				hmp->zone_limits[i] =
220 				    HAMMER_ZONE_ENCODE(i, hammer_zone_limit);
221 			}
222 			hammer_init_holes(hmp, &hmp->holes[i]);
223 		}
224 	}
225 	hmp->hflags = info.hflags;
226 	if (info.asof) {
227 		mp->mnt_flag |= MNT_RDONLY;
228 		hmp->asof = info.asof;
229 	} else {
230 		hmp->asof = HAMMER_MAX_TID;
231 	}
232 
233 	/*
234 	 * Re-open read-write if originally read-only, or vise-versa XXX
235 	 */
236 	if (mp->mnt_flag & MNT_UPDATE) {
237 		if (hmp->ronly == 0 && (mp->mnt_flag & MNT_RDONLY)) {
238 			kprintf("HAMMER read-write -> read-only XXX\n");
239 			hmp->ronly = 1;
240 		} else if (hmp->ronly && (mp->mnt_flag & MNT_RDONLY) == 0) {
241 			kprintf("HAMMER read-only -> read-write XXX\n");
242 			hmp->ronly = 0;
243 		}
244 		return(0);
245 	}
246 
247 	RB_INIT(&hmp->rb_vols_root);
248 	RB_INIT(&hmp->rb_inos_root);
249 	RB_INIT(&hmp->rb_nods_root);
250 	RB_INIT(&hmp->rb_undo_root);
251 	hmp->ronly = ((mp->mnt_flag & MNT_RDONLY) != 0);
252 
253 	TAILQ_INIT(&hmp->volu_list);
254 	TAILQ_INIT(&hmp->undo_list);
255 	TAILQ_INIT(&hmp->data_list);
256 	TAILQ_INIT(&hmp->meta_list);
257 	TAILQ_INIT(&hmp->lose_list);
258 
259 	/*
260 	 * Load volumes
261 	 */
262 	path = objcache_get(namei_oc, M_WAITOK);
263 	hmp->nvolumes = info.nvolumes;
264 	for (i = 0; i < info.nvolumes; ++i) {
265 		error = copyin(&info.volumes[i], &upath, sizeof(char *));
266 		if (error == 0)
267 			error = copyinstr(upath, path, MAXPATHLEN, NULL);
268 		if (error == 0)
269 			error = hammer_install_volume(hmp, path);
270 		if (error)
271 			break;
272 	}
273 	objcache_put(namei_oc, path);
274 
275 	/*
276 	 * Make sure we found a root volume
277 	 */
278 	if (error == 0 && hmp->rootvol == NULL) {
279 		kprintf("hammer_mount: No root volume found!\n");
280 		error = EINVAL;
281 	}
282 	if (error) {
283 		hammer_free_hmp(mp);
284 		return (error);
285 	}
286 
287 	/*
288 	 * No errors, setup enough of the mount point so we can lookup the
289 	 * root vnode.
290 	 */
291 	mp->mnt_iosize_max = MAXPHYS;
292 	mp->mnt_kern_flag |= MNTK_FSMID;
293 
294 	/*
295 	 * note: f_iosize is used by vnode_pager_haspage() when constructing
296 	 * its VOP_BMAP call.
297 	 */
298 	mp->mnt_stat.f_iosize = HAMMER_BUFSIZE;
299 	mp->mnt_stat.f_bsize = HAMMER_BUFSIZE;
300 	mp->mnt_maxsymlinklen = 255;
301 	mp->mnt_flag |= MNT_LOCAL;
302 
303 	vfs_add_vnodeops(mp, &hammer_vnode_vops, &mp->mnt_vn_norm_ops);
304 	vfs_add_vnodeops(mp, &hammer_spec_vops, &mp->mnt_vn_spec_ops);
305 	vfs_add_vnodeops(mp, &hammer_fifo_vops, &mp->mnt_vn_fifo_ops);
306 
307 	/*
308 	 * The root volume's ondisk pointer is only valid if we hold a
309 	 * reference to it.
310 	 */
311 	rootvol = hammer_get_root_volume(hmp, &error);
312 	if (error)
313 		goto failed;
314 
315 	/*
316 	 * Perform any necessary UNDO operations.  The recover code does
317 	 * call hammer_undo_lookup() so we have to pre-cache the blockmap,
318 	 * and then re-copy it again after recovery is complete.
319 	 */
320 	bcopy(rootvol->ondisk->vol0_blockmap, hmp->blockmap,
321 	      sizeof(hmp->blockmap));
322 	error = hammer_recover(hmp, rootvol);
323 	if (error) {
324 		kprintf("Failed to recover HAMMER filesystem on mount\n");
325 		goto done;
326 	}
327 
328 	/*
329 	 * Finish setup now that we have a good root volume
330 	 */
331 	ksnprintf(mp->mnt_stat.f_mntfromname,
332 		  sizeof(mp->mnt_stat.f_mntfromname), "%s",
333 		  rootvol->ondisk->vol_name);
334 	mp->mnt_stat.f_fsid.val[0] =
335 		crc32((char *)&rootvol->ondisk->vol_fsid + 0, 8);
336 	mp->mnt_stat.f_fsid.val[1] =
337 		crc32((char *)&rootvol->ondisk->vol_fsid + 8, 8);
338 
339 	/*
340 	 * Certain often-modified fields in the root volume are cached in
341 	 * the hammer_mount structure so we do not have to generate lots
342 	 * of little UNDO structures for them.
343 	 */
344 	hmp->next_tid = rootvol->ondisk->vol0_next_tid;
345 	bcopy(rootvol->ondisk->vol0_blockmap, hmp->blockmap,
346 	      sizeof(hmp->blockmap));
347 
348 	/*
349 	 * Use the zone limit set by newfs_hammer, or the zone limit set by
350 	 * sysctl (for debugging), whichever is smaller.
351 	 */
352 	if (rootvol->ondisk->vol0_zone_limit) {
353 		hammer_off_t vol0_zone_limit;
354 
355 		vol0_zone_limit = rootvol->ondisk->vol0_zone_limit;
356 		for (i = 0; i < HAMMER_MAX_ZONES; ++i) {
357 			if (hmp->zone_limits[i] > vol0_zone_limit)
358 				hmp->zone_limits[i] = vol0_zone_limit;
359 		}
360 	}
361 
362 	hammer_flusher_create(hmp);
363 
364 	/*
365 	 * Locate the root directory using the root cluster's B-Tree as a
366 	 * starting point.  The root directory uses an obj_id of 1.
367 	 *
368 	 * FUTURE: Leave the root directory cached referenced but unlocked
369 	 * in hmp->rootvp (need to flush it on unmount).
370 	 */
371 	error = hammer_vfs_vget(mp, 1, &rootvp);
372 	if (error)
373 		goto done;
374 	vput(rootvp);
375 	/*vn_unlock(hmp->rootvp);*/
376 
377 done:
378 	hammer_rel_volume(rootvol, 0);
379 failed:
380 	/*
381 	 * Cleanup and return.
382 	 */
383 	if (error)
384 		hammer_free_hmp(mp);
385 	return (error);
386 }
387 
388 static int
389 hammer_vfs_unmount(struct mount *mp, int mntflags)
390 {
391 #if 0
392 	struct hammer_mount *hmp = (void *)mp->mnt_data;
393 #endif
394 	int flags;
395 	int error;
396 
397 	/*
398 	 * Clean out the vnodes
399 	 */
400 	flags = 0;
401 	if (mntflags & MNT_FORCE)
402 		flags |= FORCECLOSE;
403 	if ((error = vflush(mp, 0, flags)) != 0)
404 		return (error);
405 
406 	/*
407 	 * Clean up the internal mount structure and related entities.  This
408 	 * may issue I/O.
409 	 */
410 	hammer_free_hmp(mp);
411 	return(0);
412 }
413 
414 /*
415  * Clean up the internal mount structure and disassociate it from the mount.
416  * This may issue I/O.
417  */
418 static void
419 hammer_free_hmp(struct mount *mp)
420 {
421 	struct hammer_mount *hmp = (void *)mp->mnt_data;
422 	int i;
423 
424 #if 0
425 	/*
426 	 * Clean up the root vnode
427 	 */
428 	if (hmp->rootvp) {
429 		vrele(hmp->rootvp);
430 		hmp->rootvp = NULL;
431 	}
432 #endif
433 	hammer_flusher_sync(hmp);
434 	hammer_flusher_sync(hmp);
435 	hammer_flusher_destroy(hmp);
436 
437 	KKASSERT(RB_EMPTY(&hmp->rb_inos_root));
438 
439 #if 0
440 	/*
441 	 * Unload & flush inodes
442 	 *
443 	 * XXX illegal to call this from here, it can only be done from
444 	 * the flusher.
445 	 */
446 	RB_SCAN(hammer_ino_rb_tree, &hmp->rb_inos_root, NULL,
447 		hammer_unload_inode, (void *)MNT_WAIT);
448 
449 	/*
450 	 * Unload & flush volumes
451 	 */
452 #endif
453 	/*
454 	 * Unload the volumes
455 	 */
456 	RB_SCAN(hammer_vol_rb_tree, &hmp->rb_vols_root, NULL,
457 		hammer_unload_volume, NULL);
458 
459 	mp->mnt_data = NULL;
460 	mp->mnt_flag &= ~MNT_LOCAL;
461 	hmp->mp = NULL;
462 	hammer_destroy_objid_cache(hmp);
463 	kfree(hmp->zbuf, M_HAMMER);
464 	lockuninit(&hmp->blockmap_lock);
465 
466 	for (i = 0; i < HAMMER_MAX_ZONES; ++i)
467 		hammer_free_holes(hmp, &hmp->holes[i]);
468 
469 	kfree(hmp, M_HAMMER);
470 }
471 
472 /*
473  * Obtain a vnode for the specified inode number.  An exclusively locked
474  * vnode is returned.
475  */
476 int
477 hammer_vfs_vget(struct mount *mp, ino_t ino, struct vnode **vpp)
478 {
479 	struct hammer_transaction trans;
480 	struct hammer_mount *hmp = (void *)mp->mnt_data;
481 	struct hammer_inode *ip;
482 	int error;
483 
484 	hammer_simple_transaction(&trans, hmp);
485 
486 	/*
487 	 * Lookup the requested HAMMER inode.  The structure must be
488 	 * left unlocked while we manipulate the related vnode to avoid
489 	 * a deadlock.
490 	 */
491 	ip = hammer_get_inode(&trans, NULL, ino, hmp->asof, 0, &error);
492 	if (ip == NULL) {
493 		*vpp = NULL;
494 		return(error);
495 	}
496 	error = hammer_get_vnode(ip, vpp);
497 	hammer_rel_inode(ip, 0);
498 	hammer_done_transaction(&trans);
499 	return (error);
500 }
501 
502 /*
503  * Return the root vnode for the filesystem.
504  *
505  * HAMMER stores the root vnode in the hammer_mount structure so
506  * getting it is easy.
507  */
508 static int
509 hammer_vfs_root(struct mount *mp, struct vnode **vpp)
510 {
511 #if 0
512 	struct hammer_mount *hmp = (void *)mp->mnt_data;
513 #endif
514 	int error;
515 
516 	error = hammer_vfs_vget(mp, 1, vpp);
517 	return (error);
518 }
519 
520 static int
521 hammer_vfs_statfs(struct mount *mp, struct statfs *sbp, struct ucred *cred)
522 {
523 	struct hammer_mount *hmp = (void *)mp->mnt_data;
524 	hammer_volume_t volume;
525 	hammer_volume_ondisk_t ondisk;
526 	int error;
527 	int64_t bfree;
528 
529 	volume = hammer_get_root_volume(hmp, &error);
530 	if (error)
531 		return(error);
532 	ondisk = volume->ondisk;
533 
534 	/*
535 	 * Basic stats
536 	 */
537 	mp->mnt_stat.f_files = ondisk->vol0_stat_inodes;
538 	bfree = ondisk->vol0_stat_freebigblocks * HAMMER_LARGEBLOCK_SIZE;
539 	hammer_rel_volume(volume, 0);
540 
541 	mp->mnt_stat.f_bfree = bfree / HAMMER_BUFSIZE;
542 	mp->mnt_stat.f_bavail = mp->mnt_stat.f_bfree;
543 	if (mp->mnt_stat.f_files < 0)
544 		mp->mnt_stat.f_files = 0;
545 
546 	*sbp = mp->mnt_stat;
547 	return(0);
548 }
549 
550 /*
551  * Sync the filesystem.  Currently we have to run it twice, the second
552  * one will advance the undo start index to the end index, so if a crash
553  * occurs no undos will be run on mount.
554  */
555 static int
556 hammer_vfs_sync(struct mount *mp, int waitfor)
557 {
558 	struct hammer_mount *hmp = (void *)mp->mnt_data;
559 	int error;
560 
561 	error = hammer_sync_hmp(hmp, waitfor);
562 	if (error == 0)
563 		error = hammer_sync_hmp(hmp, waitfor);
564 	return (error);
565 }
566 
567 /*
568  * Convert a vnode to a file handle.
569  */
570 static int
571 hammer_vfs_vptofh(struct vnode *vp, struct fid *fhp)
572 {
573 	hammer_inode_t ip;
574 
575 	KKASSERT(MAXFIDSZ >= 16);
576 	ip = VTOI(vp);
577 	fhp->fid_len = offsetof(struct fid, fid_data[16]);
578 	fhp->fid_reserved = 0;
579 	bcopy(&ip->obj_id, fhp->fid_data + 0, sizeof(ip->obj_id));
580 	bcopy(&ip->obj_asof, fhp->fid_data + 8, sizeof(ip->obj_asof));
581 	return(0);
582 }
583 
584 
585 /*
586  * Convert a file handle back to a vnode.
587  */
588 static int
589 hammer_vfs_fhtovp(struct mount *mp, struct fid *fhp, struct vnode **vpp)
590 {
591 	struct hammer_transaction trans;
592 	struct hammer_inode *ip;
593 	struct hammer_inode_info info;
594 	int error;
595 
596 	bcopy(fhp->fid_data + 0, &info.obj_id, sizeof(info.obj_id));
597 	bcopy(fhp->fid_data + 8, &info.obj_asof, sizeof(info.obj_asof));
598 
599 	hammer_simple_transaction(&trans, (void *)mp->mnt_data);
600 
601 	/*
602 	 * Get/allocate the hammer_inode structure.  The structure must be
603 	 * unlocked while we manipulate the related vnode to avoid a
604 	 * deadlock.
605 	 */
606 	ip = hammer_get_inode(&trans, NULL, info.obj_id, info.obj_asof,
607 			      0, &error);
608 	if (ip == NULL) {
609 		*vpp = NULL;
610 		return(error);
611 	}
612 	error = hammer_get_vnode(ip, vpp);
613 	hammer_rel_inode(ip, 0);
614 	hammer_done_transaction(&trans);
615 	return (error);
616 }
617 
618 static int
619 hammer_vfs_checkexp(struct mount *mp, struct sockaddr *nam,
620 		    int *exflagsp, struct ucred **credanonp)
621 {
622 	hammer_mount_t hmp = (void *)mp->mnt_data;
623 	struct netcred *np;
624 	int error;
625 
626 	np = vfs_export_lookup(mp, &hmp->export, nam);
627 	if (np) {
628 		*exflagsp = np->netc_exflags;
629 		*credanonp = &np->netc_anon;
630 		error = 0;
631 	} else {
632 		error = EACCES;
633 	}
634 	return (error);
635 
636 }
637 
638 int
639 hammer_vfs_export(struct mount *mp, int op, const struct export_args *export)
640 {
641 	hammer_mount_t hmp = (void *)mp->mnt_data;
642 	int error;
643 
644 	switch(op) {
645 	case MOUNTCTL_SET_EXPORT:
646 		error = vfs_export(mp, &hmp->export, export);
647 		break;
648 	default:
649 		error = EOPNOTSUPP;
650 		break;
651 	}
652 	return(error);
653 }
654 
655