xref: /dflybsd-src/sys/vfs/hammer/hammer_vfsops.c (revision f41d807a0c7c535d8f66f0593fb6e95fa20f82d4)
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 
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/kernel.h>
38 #include <sys/vnode.h>
39 #include <sys/mount.h>
40 #include <sys/malloc.h>
41 #include <sys/nlookup.h>
42 #include <sys/fcntl.h>
43 #include <sys/sysctl.h>
44 #include <sys/buf.h>
45 #include <sys/buf2.h>
46 #include "hammer.h"
47 
48 /*
49  * NOTE!  Global statistics may not be MPSAFE so HAMMER never uses them
50  *	  in conditionals.
51  */
52 int hammer_supported_version = HAMMER_VOL_VERSION_DEFAULT;
53 int hammer_debug_io;
54 int hammer_debug_general;
55 int hammer_debug_debug = 1;		/* medium-error panics */
56 int hammer_debug_inode;
57 int hammer_debug_locks;
58 int hammer_debug_btree;
59 int hammer_debug_tid;
60 int hammer_debug_recover;		/* -1 will disable, +1 will force */
61 int hammer_debug_recover_faults;
62 int hammer_debug_critical;		/* non-zero enter debugger on error */
63 int hammer_cluster_enable = 1;		/* enable read clustering by default */
64 int hammer_live_dedup = 0;
65 int hammer_tdmux_ticks;
66 int hammer_count_fsyncs;
67 int hammer_count_inodes;
68 int hammer_count_iqueued;
69 int hammer_count_reclaims;
70 int hammer_count_records;
71 int hammer_count_record_datas;
72 int hammer_count_volumes;
73 int hammer_count_buffers;
74 int hammer_count_nodes;
75 int64_t hammer_count_extra_space_used;
76 int64_t hammer_stats_btree_lookups;
77 int64_t hammer_stats_btree_searches;
78 int64_t hammer_stats_btree_inserts;
79 int64_t hammer_stats_btree_deletes;
80 int64_t hammer_stats_btree_elements;
81 int64_t hammer_stats_btree_splits;
82 int64_t hammer_stats_btree_iterations;
83 int64_t hammer_stats_btree_root_iterations;
84 int64_t hammer_stats_record_iterations;
85 
86 int64_t hammer_stats_file_read;
87 int64_t hammer_stats_file_write;
88 int64_t hammer_stats_file_iopsr;
89 int64_t hammer_stats_file_iopsw;
90 int64_t hammer_stats_disk_read;
91 int64_t hammer_stats_disk_write;
92 int64_t hammer_stats_inode_flushes;
93 int64_t hammer_stats_commits;
94 int64_t hammer_stats_undo;
95 int64_t hammer_stats_redo;
96 
97 int hammer_count_dirtybufspace;		/* global */
98 int hammer_count_refedbufs;		/* global */
99 int hammer_count_reservations;
100 int hammer_count_io_running_read;
101 int hammer_count_io_running_write;
102 int hammer_count_io_locked;
103 int hammer_limit_dirtybufspace;		/* per-mount */
104 int hammer_limit_running_io;		/* per-mount */
105 int hammer_limit_recs;			/* as a whole XXX */
106 int hammer_limit_inode_recs = 2048;	/* per inode */
107 int hammer_limit_reclaims;
108 int hammer_live_dedup_cache_size = DEDUP_CACHE_SIZE;
109 int hammer_limit_redo = 4096 * 1024;	/* per inode */
110 int hammer_autoflush = 500;		/* auto flush (typ on reclaim) */
111 int hammer_bio_count;
112 int hammer_verify_zone;
113 int hammer_verify_data = 1;
114 int hammer_write_mode;
115 int hammer_double_buffer;
116 int hammer_yield_check = 16;
117 int hammer_fsync_mode = 3;
118 int64_t hammer_contention_count;
119 int64_t hammer_zone_limit;
120 
121 /*
122  * Live dedup debug counters (sysctls are writable so that counters
123  * can be reset from userspace).
124  */
125 int64_t hammer_live_dedup_vnode_bcmps = 0;
126 int64_t hammer_live_dedup_device_bcmps = 0;
127 int64_t hammer_live_dedup_findblk_failures = 0;
128 int64_t hammer_live_dedup_bmap_saves = 0;
129 
130 
131 SYSCTL_NODE(_vfs, OID_AUTO, hammer, CTLFLAG_RW, 0, "HAMMER filesystem");
132 
133 SYSCTL_INT(_vfs_hammer, OID_AUTO, supported_version, CTLFLAG_RD,
134 	   &hammer_supported_version, 0, "");
135 SYSCTL_INT(_vfs_hammer, OID_AUTO, debug_general, CTLFLAG_RW,
136 	   &hammer_debug_general, 0, "");
137 SYSCTL_INT(_vfs_hammer, OID_AUTO, debug_io, CTLFLAG_RW,
138 	   &hammer_debug_io, 0, "");
139 SYSCTL_INT(_vfs_hammer, OID_AUTO, debug_debug, CTLFLAG_RW,
140 	   &hammer_debug_debug, 0, "");
141 SYSCTL_INT(_vfs_hammer, OID_AUTO, debug_inode, CTLFLAG_RW,
142 	   &hammer_debug_inode, 0, "");
143 SYSCTL_INT(_vfs_hammer, OID_AUTO, debug_locks, CTLFLAG_RW,
144 	   &hammer_debug_locks, 0, "");
145 SYSCTL_INT(_vfs_hammer, OID_AUTO, debug_btree, CTLFLAG_RW,
146 	   &hammer_debug_btree, 0, "");
147 SYSCTL_INT(_vfs_hammer, OID_AUTO, debug_tid, CTLFLAG_RW,
148 	   &hammer_debug_tid, 0, "");
149 SYSCTL_INT(_vfs_hammer, OID_AUTO, debug_recover, CTLFLAG_RW,
150 	   &hammer_debug_recover, 0, "");
151 SYSCTL_INT(_vfs_hammer, OID_AUTO, debug_recover_faults, CTLFLAG_RW,
152 	   &hammer_debug_recover_faults, 0, "");
153 SYSCTL_INT(_vfs_hammer, OID_AUTO, debug_critical, CTLFLAG_RW,
154 	   &hammer_debug_critical, 0, "");
155 SYSCTL_INT(_vfs_hammer, OID_AUTO, cluster_enable, CTLFLAG_RW,
156 	   &hammer_cluster_enable, 0, "");
157 /*
158  * 0 - live dedup is disabled
159  * 1 - dedup cache is populated on reads only
160  * 2 - dedup cache is populated on both reads and writes
161  */
162 SYSCTL_INT(_vfs_hammer, OID_AUTO, live_dedup, CTLFLAG_RW,
163 	   &hammer_live_dedup, 0, "Enable live dedup");
164 SYSCTL_INT(_vfs_hammer, OID_AUTO, tdmux_ticks, CTLFLAG_RW,
165 	   &hammer_tdmux_ticks, 0, "Hammer tdmux ticks");
166 
167 SYSCTL_INT(_vfs_hammer, OID_AUTO, limit_dirtybufspace, CTLFLAG_RW,
168 	   &hammer_limit_dirtybufspace, 0, "");
169 SYSCTL_INT(_vfs_hammer, OID_AUTO, limit_running_io, CTLFLAG_RW,
170 	   &hammer_limit_running_io, 0, "");
171 SYSCTL_INT(_vfs_hammer, OID_AUTO, limit_recs, CTLFLAG_RW,
172 	   &hammer_limit_recs, 0, "");
173 SYSCTL_INT(_vfs_hammer, OID_AUTO, limit_inode_recs, CTLFLAG_RW,
174 	   &hammer_limit_inode_recs, 0, "");
175 SYSCTL_INT(_vfs_hammer, OID_AUTO, limit_reclaims, CTLFLAG_RW,
176 	   &hammer_limit_reclaims, 0, "");
177 SYSCTL_INT(_vfs_hammer, OID_AUTO, live_dedup_cache_size, CTLFLAG_RW,
178 	   &hammer_live_dedup_cache_size, 0,
179 	   "Number of cache entries");
180 SYSCTL_INT(_vfs_hammer, OID_AUTO, limit_redo, CTLFLAG_RW,
181 	   &hammer_limit_redo, 0, "");
182 
183 SYSCTL_INT(_vfs_hammer, OID_AUTO, count_fsyncs, CTLFLAG_RD,
184 	   &hammer_count_fsyncs, 0, "");
185 SYSCTL_INT(_vfs_hammer, OID_AUTO, count_inodes, CTLFLAG_RD,
186 	   &hammer_count_inodes, 0, "");
187 SYSCTL_INT(_vfs_hammer, OID_AUTO, count_iqueued, CTLFLAG_RD,
188 	   &hammer_count_iqueued, 0, "");
189 SYSCTL_INT(_vfs_hammer, OID_AUTO, count_reclaims, CTLFLAG_RD,
190 	   &hammer_count_reclaims, 0, "");
191 SYSCTL_INT(_vfs_hammer, OID_AUTO, count_records, CTLFLAG_RD,
192 	   &hammer_count_records, 0, "");
193 SYSCTL_INT(_vfs_hammer, OID_AUTO, count_record_datas, CTLFLAG_RD,
194 	   &hammer_count_record_datas, 0, "");
195 SYSCTL_INT(_vfs_hammer, OID_AUTO, count_volumes, CTLFLAG_RD,
196 	   &hammer_count_volumes, 0, "");
197 SYSCTL_INT(_vfs_hammer, OID_AUTO, count_buffers, CTLFLAG_RD,
198 	   &hammer_count_buffers, 0, "");
199 SYSCTL_INT(_vfs_hammer, OID_AUTO, count_nodes, CTLFLAG_RD,
200 	   &hammer_count_nodes, 0, "");
201 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, count_extra_space_used, CTLFLAG_RD,
202 	   &hammer_count_extra_space_used, 0, "");
203 
204 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, stats_btree_searches, CTLFLAG_RD,
205 	   &hammer_stats_btree_searches, 0, "");
206 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, stats_btree_lookups, CTLFLAG_RD,
207 	   &hammer_stats_btree_lookups, 0, "");
208 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, stats_btree_inserts, CTLFLAG_RD,
209 	   &hammer_stats_btree_inserts, 0, "");
210 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, stats_btree_deletes, CTLFLAG_RD,
211 	   &hammer_stats_btree_deletes, 0, "");
212 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, stats_btree_elements, CTLFLAG_RD,
213 	   &hammer_stats_btree_elements, 0, "");
214 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, stats_btree_splits, CTLFLAG_RD,
215 	   &hammer_stats_btree_splits, 0, "");
216 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, stats_btree_iterations, CTLFLAG_RD,
217 	   &hammer_stats_btree_iterations, 0, "");
218 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, stats_btree_root_iterations, CTLFLAG_RD,
219 	   &hammer_stats_btree_root_iterations, 0, "");
220 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, stats_record_iterations, CTLFLAG_RD,
221 	   &hammer_stats_record_iterations, 0, "");
222 
223 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, stats_file_read, CTLFLAG_RD,
224 	   &hammer_stats_file_read, 0, "");
225 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, stats_file_write, CTLFLAG_RD,
226 	   &hammer_stats_file_write, 0, "");
227 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, stats_file_iopsr, CTLFLAG_RD,
228 	   &hammer_stats_file_iopsr, 0, "");
229 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, stats_file_iopsw, CTLFLAG_RD,
230 	   &hammer_stats_file_iopsw, 0, "");
231 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, stats_disk_read, CTLFLAG_RD,
232 	   &hammer_stats_disk_read, 0, "");
233 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, stats_disk_write, CTLFLAG_RD,
234 	   &hammer_stats_disk_write, 0, "");
235 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, stats_inode_flushes, CTLFLAG_RD,
236 	   &hammer_stats_inode_flushes, 0, "");
237 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, stats_commits, CTLFLAG_RD,
238 	   &hammer_stats_commits, 0, "");
239 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, stats_undo, CTLFLAG_RD,
240 	   &hammer_stats_undo, 0, "");
241 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, stats_redo, CTLFLAG_RD,
242 	   &hammer_stats_redo, 0, "");
243 
244 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, live_dedup_vnode_bcmps, CTLFLAG_RW,
245 	    &hammer_live_dedup_vnode_bcmps, 0,
246 	    "successful vnode buffer comparisons");
247 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, live_dedup_device_bcmps, CTLFLAG_RW,
248 	    &hammer_live_dedup_device_bcmps, 0,
249 	    "successful device buffer comparisons");
250 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, live_dedup_findblk_failures, CTLFLAG_RW,
251 	    &hammer_live_dedup_findblk_failures, 0,
252 	    "block lookup failures for comparison");
253 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, live_dedup_bmap_saves, CTLFLAG_RW,
254 	    &hammer_live_dedup_bmap_saves, 0,
255 	    "useful physical block lookups");
256 
257 SYSCTL_INT(_vfs_hammer, OID_AUTO, count_dirtybufspace, CTLFLAG_RD,
258 	   &hammer_count_dirtybufspace, 0, "");
259 SYSCTL_INT(_vfs_hammer, OID_AUTO, count_refedbufs, CTLFLAG_RD,
260 	   &hammer_count_refedbufs, 0, "");
261 SYSCTL_INT(_vfs_hammer, OID_AUTO, count_reservations, CTLFLAG_RD,
262 	   &hammer_count_reservations, 0, "");
263 SYSCTL_INT(_vfs_hammer, OID_AUTO, count_io_running_read, CTLFLAG_RD,
264 	   &hammer_count_io_running_read, 0, "");
265 SYSCTL_INT(_vfs_hammer, OID_AUTO, count_io_locked, CTLFLAG_RD,
266 	   &hammer_count_io_locked, 0, "");
267 SYSCTL_INT(_vfs_hammer, OID_AUTO, count_io_running_write, CTLFLAG_RD,
268 	   &hammer_count_io_running_write, 0, "");
269 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, zone_limit, CTLFLAG_RW,
270 	   &hammer_zone_limit, 0, "");
271 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, contention_count, CTLFLAG_RW,
272 	   &hammer_contention_count, 0, "");
273 SYSCTL_INT(_vfs_hammer, OID_AUTO, autoflush, CTLFLAG_RW,
274 	   &hammer_autoflush, 0, "");
275 SYSCTL_INT(_vfs_hammer, OID_AUTO, verify_zone, CTLFLAG_RW,
276 	   &hammer_verify_zone, 0, "");
277 SYSCTL_INT(_vfs_hammer, OID_AUTO, verify_data, CTLFLAG_RW,
278 	   &hammer_verify_data, 0, "");
279 SYSCTL_INT(_vfs_hammer, OID_AUTO, write_mode, CTLFLAG_RW,
280 	   &hammer_write_mode, 0, "");
281 SYSCTL_INT(_vfs_hammer, OID_AUTO, double_buffer, CTLFLAG_RW,
282 	   &hammer_double_buffer, 0, "");
283 SYSCTL_INT(_vfs_hammer, OID_AUTO, yield_check, CTLFLAG_RW,
284 	   &hammer_yield_check, 0, "");
285 SYSCTL_INT(_vfs_hammer, OID_AUTO, fsync_mode, CTLFLAG_RW,
286 	   &hammer_fsync_mode, 0, "");
287 
288 /* KTR_INFO_MASTER(hammer); */
289 
290 /*
291  * VFS ABI
292  */
293 static void	hammer_free_hmp(struct mount *mp);
294 
295 static int	hammer_vfs_mount(struct mount *mp, char *path, caddr_t data,
296 				struct ucred *cred);
297 static int	hammer_vfs_unmount(struct mount *mp, int mntflags);
298 static int	hammer_vfs_root(struct mount *mp, struct vnode **vpp);
299 static int	hammer_vfs_statfs(struct mount *mp, struct statfs *sbp,
300 				struct ucred *cred);
301 static int	hammer_vfs_statvfs(struct mount *mp, struct statvfs *sbp,
302 				struct ucred *cred);
303 static int	hammer_vfs_sync(struct mount *mp, int waitfor);
304 static int	hammer_vfs_vget(struct mount *mp, struct vnode *dvp,
305 				ino_t ino, struct vnode **vpp);
306 static int	hammer_vfs_init(struct vfsconf *conf);
307 static int	hammer_vfs_fhtovp(struct mount *mp, struct vnode *rootvp,
308 				struct fid *fhp, struct vnode **vpp);
309 static int	hammer_vfs_vptofh(struct vnode *vp, struct fid *fhp);
310 static int	hammer_vfs_checkexp(struct mount *mp, struct sockaddr *nam,
311 				int *exflagsp, struct ucred **credanonp);
312 
313 
314 static struct vfsops hammer_vfsops = {
315 	.vfs_mount	= hammer_vfs_mount,
316 	.vfs_unmount	= hammer_vfs_unmount,
317 	.vfs_root 	= hammer_vfs_root,
318 	.vfs_statfs	= hammer_vfs_statfs,
319 	.vfs_statvfs	= hammer_vfs_statvfs,
320 	.vfs_sync	= hammer_vfs_sync,
321 	.vfs_vget	= hammer_vfs_vget,
322 	.vfs_init	= hammer_vfs_init,
323 	.vfs_vptofh	= hammer_vfs_vptofh,
324 	.vfs_fhtovp	= hammer_vfs_fhtovp,
325 	.vfs_checkexp	= hammer_vfs_checkexp
326 };
327 
328 MALLOC_DEFINE(M_HAMMER, "HAMMER-mount", "");
329 
330 VFS_SET(hammer_vfsops, hammer, 0);
331 MODULE_VERSION(hammer, 1);
332 
333 static int
334 hammer_vfs_init(struct vfsconf *conf)
335 {
336 	int n;
337 
338 	/*
339 	 * Wait up to this long for an exclusive deadlock to clear
340 	 * before acquiring a new shared lock on the ip.  The deadlock
341 	 * may have occured on a b-tree node related to the ip.
342 	 */
343 	if (hammer_tdmux_ticks == 0)
344 		hammer_tdmux_ticks = hz / 5;
345 
346 	/*
347 	 * Autosize
348 	 */
349 	if (hammer_limit_recs == 0) {
350 		hammer_limit_recs = nbuf * 25;
351 		n = kmalloc_limit(M_HAMMER) / 512;
352 		if (hammer_limit_recs > n)
353 			hammer_limit_recs = n;
354 	}
355 	if (hammer_limit_dirtybufspace == 0) {
356 		hammer_limit_dirtybufspace = hidirtybufspace / 2;
357 		if (hammer_limit_dirtybufspace < 100)
358 			hammer_limit_dirtybufspace = 100;
359 	}
360 
361 	/*
362 	 * Set reasonable limits to maintain an I/O pipeline.  This is
363 	 * used by the flush code which explicitly initiates I/O, and
364 	 * is per-mount.
365 	 *
366 	 * The system-driven buffer cache uses vfs.lorunningspace and
367 	 * vfs.hirunningspace globally.
368 	 */
369 	if (hammer_limit_running_io == 0)
370 		hammer_limit_running_io = hammer_limit_dirtybufspace;
371 
372 	if (hammer_limit_running_io > 10 * 1024 * 1024)
373 		hammer_limit_running_io = 10 * 1024 * 1024;
374 
375 	/*
376 	 * The hammer_inode structure detaches from the vnode on reclaim.
377 	 * This limits the number of inodes in this state to prevent a
378 	 * memory pool blowout.
379 	 */
380 	if (hammer_limit_reclaims == 0)
381 		hammer_limit_reclaims = desiredvnodes / 10;
382 
383 	return(0);
384 }
385 
386 static int
387 hammer_vfs_mount(struct mount *mp, char *mntpt, caddr_t data,
388 		 struct ucred *cred)
389 {
390 	struct hammer_mount_info info;
391 	hammer_mount_t hmp;
392 	hammer_volume_t rootvol;
393 	struct vnode *rootvp;
394 	struct vnode *devvp = NULL;
395 	const char *upath;	/* volume name in userspace */
396 	char *path;		/* volume name in system space */
397 	int error;
398 	int i;
399 	int master_id;
400 	char *next_volume_ptr = NULL;
401 
402 	/*
403 	 * Accept hammer_mount_info.  mntpt is NULL for root mounts at boot.
404 	 */
405 	if (mntpt == NULL) {
406 		bzero(&info, sizeof(info));
407 		info.asof = 0;
408 		info.hflags = 0;
409 		info.nvolumes = 1;
410 
411 		next_volume_ptr = mp->mnt_stat.f_mntfromname;
412 
413 		/* Count number of volumes separated by ':' */
414 		for (char *p = next_volume_ptr; *p != '\0'; ++p) {
415 			if (*p == ':') {
416 				++info.nvolumes;
417 			}
418 		}
419 
420 		mp->mnt_flag &= ~MNT_RDONLY; /* mount R/W */
421 	} else {
422 		if ((error = copyin(data, &info, sizeof(info))) != 0)
423 			return (error);
424 	}
425 
426 	/*
427 	 * updating or new mount
428 	 */
429 	if (mp->mnt_flag & MNT_UPDATE) {
430 		hmp = (void *)mp->mnt_data;
431 		KKASSERT(hmp != NULL);
432 	} else {
433 		if (info.nvolumes <= 0 || info.nvolumes >= 32768)
434 			return (EINVAL);
435 		hmp = NULL;
436 	}
437 
438 	/*
439 	 * master-id validation.  The master id may not be changed by a
440 	 * mount update.
441 	 */
442 	if (info.hflags & HMNT_MASTERID) {
443 		if (hmp && hmp->master_id != info.master_id) {
444 			kprintf("hammer: cannot change master id "
445 				"with mount update\n");
446 			return(EINVAL);
447 		}
448 		master_id = info.master_id;
449 		if (master_id < -1 || master_id >= HAMMER_MAX_MASTERS)
450 			return (EINVAL);
451 	} else {
452 		if (hmp)
453 			master_id = hmp->master_id;
454 		else
455 			master_id = 0;
456 	}
457 
458 	/*
459 	 * Internal mount data structure
460 	 */
461 	if (hmp == NULL) {
462 		hmp = kmalloc(sizeof(*hmp), M_HAMMER, M_WAITOK | M_ZERO);
463 		mp->mnt_data = (qaddr_t)hmp;
464 		hmp->mp = mp;
465 		/*TAILQ_INIT(&hmp->recycle_list);*/
466 
467 		/*
468 		 * Make sure kmalloc type limits are set appropriately.
469 		 *
470 		 * Our inode kmalloc group is sized based on maxvnodes
471 		 * (controlled by the system, not us).
472 		 */
473 		kmalloc_create(&hmp->m_misc, "HAMMER-others");
474 		kmalloc_create(&hmp->m_inodes, "HAMMER-inodes");
475 
476 		kmalloc_raise_limit(hmp->m_inodes, 0);	/* unlimited */
477 
478 		hmp->root_btree_beg.localization = 0x00000000U;
479 		hmp->root_btree_beg.obj_id = -0x8000000000000000LL;
480 		hmp->root_btree_beg.key = -0x8000000000000000LL;
481 		hmp->root_btree_beg.create_tid = 1;
482 		hmp->root_btree_beg.delete_tid = 1;
483 		hmp->root_btree_beg.rec_type = 0;
484 		hmp->root_btree_beg.obj_type = 0;
485 
486 		hmp->root_btree_end.localization = 0xFFFFFFFFU;
487 		hmp->root_btree_end.obj_id = 0x7FFFFFFFFFFFFFFFLL;
488 		hmp->root_btree_end.key = 0x7FFFFFFFFFFFFFFFLL;
489 		hmp->root_btree_end.create_tid = 0xFFFFFFFFFFFFFFFFULL;
490 		hmp->root_btree_end.delete_tid = 0;   /* special case */
491 		hmp->root_btree_end.rec_type = 0xFFFFU;
492 		hmp->root_btree_end.obj_type = 0;
493 
494 		hmp->krate.freq = 1;	/* maximum reporting rate (hz) */
495 		hmp->krate.count = -16;	/* initial burst */
496 
497 		hmp->sync_lock.refs = 1;
498 		hmp->free_lock.refs = 1;
499 		hmp->undo_lock.refs = 1;
500 		hmp->blkmap_lock.refs = 1;
501 		hmp->snapshot_lock.refs = 1;
502 		hmp->volume_lock.refs = 1;
503 
504 		TAILQ_INIT(&hmp->delay_list);
505 		TAILQ_INIT(&hmp->flush_group_list);
506 		TAILQ_INIT(&hmp->objid_cache_list);
507 		TAILQ_INIT(&hmp->undo_lru_list);
508 		TAILQ_INIT(&hmp->reclaim_list);
509 
510 		RB_INIT(&hmp->rb_dedup_crc_root);
511 		RB_INIT(&hmp->rb_dedup_off_root);
512 		TAILQ_INIT(&hmp->dedup_lru_list);
513 	}
514 	hmp->hflags &= ~HMNT_USERFLAGS;
515 	hmp->hflags |= info.hflags & HMNT_USERFLAGS;
516 
517 	hmp->master_id = master_id;
518 
519 	if (info.asof) {
520 		mp->mnt_flag |= MNT_RDONLY;
521 		hmp->asof = info.asof;
522 	} else {
523 		hmp->asof = HAMMER_MAX_TID;
524 	}
525 
526 	hmp->volume_to_remove = -1;
527 
528 	/*
529 	 * Re-open read-write if originally read-only, or vise-versa.
530 	 *
531 	 * When going from read-only to read-write execute the stage2
532 	 * recovery if it has not already been run.
533 	 */
534 	if (mp->mnt_flag & MNT_UPDATE) {
535 		lwkt_gettoken(&hmp->fs_token);
536 		error = 0;
537 		if (hmp->ronly && (mp->mnt_kern_flag & MNTK_WANTRDWR)) {
538 			kprintf("HAMMER read-only -> read-write\n");
539 			hmp->ronly = 0;
540 			RB_SCAN(hammer_vol_rb_tree, &hmp->rb_vols_root, NULL,
541 				hammer_adjust_volume_mode, NULL);
542 			rootvol = hammer_get_root_volume(hmp, &error);
543 			if (rootvol) {
544 				hammer_recover_flush_buffers(hmp, rootvol, 1);
545 				error = hammer_recover_stage2(hmp, rootvol);
546 				bcopy(rootvol->ondisk->vol0_blockmap,
547 				      hmp->blockmap,
548 				      sizeof(hmp->blockmap));
549 				hammer_rel_volume(rootvol, 0);
550 			}
551 			RB_SCAN(hammer_ino_rb_tree, &hmp->rb_inos_root, NULL,
552 				hammer_reload_inode, NULL);
553 			/* kernel clears MNT_RDONLY */
554 		} else if (hmp->ronly == 0 && (mp->mnt_flag & MNT_RDONLY)) {
555 			kprintf("HAMMER read-write -> read-only\n");
556 			hmp->ronly = 1;	/* messy */
557 			RB_SCAN(hammer_ino_rb_tree, &hmp->rb_inos_root, NULL,
558 				hammer_reload_inode, NULL);
559 			hmp->ronly = 0;
560 			hammer_flusher_sync(hmp);
561 			hammer_flusher_sync(hmp);
562 			hammer_flusher_sync(hmp);
563 			hmp->ronly = 1;
564 			RB_SCAN(hammer_vol_rb_tree, &hmp->rb_vols_root, NULL,
565 				hammer_adjust_volume_mode, NULL);
566 		}
567 		lwkt_reltoken(&hmp->fs_token);
568 		return(error);
569 	}
570 
571 	RB_INIT(&hmp->rb_vols_root);
572 	RB_INIT(&hmp->rb_inos_root);
573 	RB_INIT(&hmp->rb_redo_root);
574 	RB_INIT(&hmp->rb_nods_root);
575 	RB_INIT(&hmp->rb_undo_root);
576 	RB_INIT(&hmp->rb_resv_root);
577 	RB_INIT(&hmp->rb_bufs_root);
578 	RB_INIT(&hmp->rb_pfsm_root);
579 
580 	hmp->ronly = ((mp->mnt_flag & MNT_RDONLY) != 0);
581 
582 	RB_INIT(&hmp->volu_root);
583 	RB_INIT(&hmp->undo_root);
584 	RB_INIT(&hmp->data_root);
585 	RB_INIT(&hmp->meta_root);
586 	RB_INIT(&hmp->lose_root);
587 	TAILQ_INIT(&hmp->iorun_list);
588 
589 	lwkt_token_init(&hmp->fs_token, "hammerfs");
590 	lwkt_token_init(&hmp->io_token, "hammerio");
591 
592 	lwkt_gettoken(&hmp->fs_token);
593 
594 	/*
595 	 * Load volumes
596 	 */
597 	path = objcache_get(namei_oc, M_WAITOK);
598 	hmp->nvolumes = -1;
599 	for (i = 0; i < info.nvolumes; ++i) {
600 		if (mntpt == NULL) {
601 			/*
602 			 * Root mount.
603 			 */
604 			KKASSERT(next_volume_ptr != NULL);
605 			strcpy(path, "");
606 			if (*next_volume_ptr != '/') {
607 				/* relative path */
608 				strcpy(path, "/dev/");
609 			}
610 			int k;
611 			for (k = strlen(path); k < MAXPATHLEN-1; ++k) {
612 				if (*next_volume_ptr == '\0') {
613 					break;
614 				} else if (*next_volume_ptr == ':') {
615 					++next_volume_ptr;
616 					break;
617 				} else {
618 					path[k] = *next_volume_ptr;
619 					++next_volume_ptr;
620 				}
621 			}
622 			path[k] = '\0';
623 
624 			error = 0;
625 			cdev_t dev = kgetdiskbyname(path);
626 			error = bdevvp(dev, &devvp);
627 			if (error) {
628 				kprintf("hammer_mountroot: can't find devvp\n");
629 			}
630 		} else {
631 			error = copyin(&info.volumes[i], &upath,
632 				       sizeof(char *));
633 			if (error == 0)
634 				error = copyinstr(upath, path,
635 						  MAXPATHLEN, NULL);
636 		}
637 		if (error == 0)
638 			error = hammer_install_volume(hmp, path, devvp);
639 		if (error)
640 			break;
641 	}
642 	objcache_put(namei_oc, path);
643 
644 	/*
645 	 * Make sure we found a root volume
646 	 */
647 	if (error == 0 && hmp->rootvol == NULL) {
648 		kprintf("hammer_mount: No root volume found!\n");
649 		error = EINVAL;
650 	}
651 
652 	/*
653 	 * Check that all required volumes are available
654 	 */
655 	if (error == 0 && hammer_mountcheck_volumes(hmp)) {
656 		kprintf("hammer_mount: Missing volumes, cannot mount!\n");
657 		error = EINVAL;
658 	}
659 
660 	if (error) {
661 		/* called with fs_token held */
662 		hammer_free_hmp(mp);
663 		return (error);
664 	}
665 
666 	/*
667 	 * No errors, setup enough of the mount point so we can lookup the
668 	 * root vnode.
669 	 */
670 	mp->mnt_iosize_max = MAXPHYS;
671 	mp->mnt_kern_flag |= MNTK_FSMID;
672 
673 	/*
674 	 * MPSAFE code.  Note that VOPs and VFSops which are not MPSAFE
675 	 * will acquire a per-mount token prior to entry and release it
676 	 * on return, so even if we do not specify it we no longer get
677 	 * the BGL regardlless of how we are flagged.
678 	 */
679 	mp->mnt_kern_flag |= MNTK_ALL_MPSAFE;
680 	/*MNTK_RD_MPSAFE | MNTK_GA_MPSAFE | MNTK_IN_MPSAFE;*/
681 
682 	/*
683 	 * note: f_iosize is used by vnode_pager_haspage() when constructing
684 	 * its VOP_BMAP call.
685 	 */
686 	mp->mnt_stat.f_iosize = HAMMER_BUFSIZE;
687 	mp->mnt_stat.f_bsize = HAMMER_BUFSIZE;
688 
689 	mp->mnt_vstat.f_frsize = HAMMER_BUFSIZE;
690 	mp->mnt_vstat.f_bsize = HAMMER_BUFSIZE;
691 
692 	mp->mnt_maxsymlinklen = 255;
693 	mp->mnt_flag |= MNT_LOCAL;
694 
695 	vfs_add_vnodeops(mp, &hammer_vnode_vops, &mp->mnt_vn_norm_ops);
696 	vfs_add_vnodeops(mp, &hammer_spec_vops, &mp->mnt_vn_spec_ops);
697 	vfs_add_vnodeops(mp, &hammer_fifo_vops, &mp->mnt_vn_fifo_ops);
698 
699 	/*
700 	 * The root volume's ondisk pointer is only valid if we hold a
701 	 * reference to it.
702 	 */
703 	rootvol = hammer_get_root_volume(hmp, &error);
704 	if (error)
705 		goto failed;
706 
707 	/*
708 	 * Perform any necessary UNDO operations.  The recovery code does
709 	 * call hammer_undo_lookup() so we have to pre-cache the blockmap,
710 	 * and then re-copy it again after recovery is complete.
711 	 *
712 	 * If this is a read-only mount the UNDO information is retained
713 	 * in memory in the form of dirty buffer cache buffers, and not
714 	 * written back to the media.
715 	 */
716 	bcopy(rootvol->ondisk->vol0_blockmap, hmp->blockmap,
717 	      sizeof(hmp->blockmap));
718 
719 	/*
720 	 * Check filesystem version
721 	 */
722 	hmp->version = rootvol->ondisk->vol_version;
723 	if (hmp->version < HAMMER_VOL_VERSION_MIN ||
724 	    hmp->version > HAMMER_VOL_VERSION_MAX) {
725 		kprintf("HAMMER: mount unsupported fs version %d\n",
726 			hmp->version);
727 		error = ERANGE;
728 		goto done;
729 	}
730 
731 	/*
732 	 * The undo_rec_limit limits the size of flush groups to avoid
733 	 * blowing out the UNDO FIFO.  This calculation is typically in
734 	 * the tens of thousands and is designed primarily when small
735 	 * HAMMER filesystems are created.
736 	 */
737 	hmp->undo_rec_limit = hammer_undo_max(hmp) / 8192 + 100;
738 	if (hammer_debug_general & 0x0001)
739 		kprintf("HAMMER: undo_rec_limit %d\n", hmp->undo_rec_limit);
740 
741 	/*
742 	 * NOTE: Recover stage1 not only handles meta-data recovery, it
743 	 * 	 also sets hmp->undo_seqno for HAMMER VERSION 4+ filesystems.
744 	 */
745 	error = hammer_recover_stage1(hmp, rootvol);
746 	if (error) {
747 		kprintf("Failed to recover HAMMER filesystem on mount\n");
748 		goto done;
749 	}
750 
751 	/*
752 	 * Finish setup now that we have a good root volume.
753 	 *
754 	 * The top 16 bits of fsid.val[1] is a pfs id.
755 	 */
756 	ksnprintf(mp->mnt_stat.f_mntfromname,
757 		  sizeof(mp->mnt_stat.f_mntfromname), "%s",
758 		  rootvol->ondisk->vol_name);
759 	mp->mnt_stat.f_fsid.val[0] =
760 		crc32((char *)&rootvol->ondisk->vol_fsid + 0, 8);
761 	mp->mnt_stat.f_fsid.val[1] =
762 		crc32((char *)&rootvol->ondisk->vol_fsid + 8, 8);
763 	mp->mnt_stat.f_fsid.val[1] &= 0x0000FFFF;
764 
765 	mp->mnt_vstat.f_fsid_uuid = rootvol->ondisk->vol_fsid;
766 	mp->mnt_vstat.f_fsid = crc32(&mp->mnt_vstat.f_fsid_uuid,
767 				     sizeof(mp->mnt_vstat.f_fsid_uuid));
768 
769 	/*
770 	 * Certain often-modified fields in the root volume are cached in
771 	 * the hammer_mount structure so we do not have to generate lots
772 	 * of little UNDO structures for them.
773 	 *
774 	 * Recopy after recovery.  This also has the side effect of
775 	 * setting our cached undo FIFO's first_offset, which serves to
776 	 * placemark the FIFO start for the NEXT flush cycle while the
777 	 * on-disk first_offset represents the LAST flush cycle.
778 	 */
779 	hmp->next_tid = rootvol->ondisk->vol0_next_tid;
780 	hmp->flush_tid1 = hmp->next_tid;
781 	hmp->flush_tid2 = hmp->next_tid;
782 	bcopy(rootvol->ondisk->vol0_blockmap, hmp->blockmap,
783 	      sizeof(hmp->blockmap));
784 	hmp->copy_stat_freebigblocks = rootvol->ondisk->vol0_stat_freebigblocks;
785 
786 	hammer_flusher_create(hmp);
787 
788 	/*
789 	 * Locate the root directory using the root cluster's B-Tree as a
790 	 * starting point.  The root directory uses an obj_id of 1.
791 	 *
792 	 * FUTURE: Leave the root directory cached referenced but unlocked
793 	 * in hmp->rootvp (need to flush it on unmount).
794 	 */
795 	error = hammer_vfs_vget(mp, NULL, 1, &rootvp);
796 	if (error)
797 		goto done;
798 	vput(rootvp);
799 	/*vn_unlock(hmp->rootvp);*/
800 	if (hmp->ronly == 0)
801 		error = hammer_recover_stage2(hmp, rootvol);
802 
803 	/*
804 	 * If the stage2 recovery fails be sure to clean out all cached
805 	 * vnodes before throwing away the mount structure or bad things
806 	 * will happen.
807 	 */
808 	if (error)
809 		vflush(mp, 0, 0);
810 
811 done:
812 	hammer_rel_volume(rootvol, 0);
813 failed:
814 	/*
815 	 * Cleanup and return.
816 	 */
817 	if (error) {
818 		/* called with fs_token held */
819 		hammer_free_hmp(mp);
820 	} else {
821 		lwkt_reltoken(&hmp->fs_token);
822 	}
823 	return (error);
824 }
825 
826 static int
827 hammer_vfs_unmount(struct mount *mp, int mntflags)
828 {
829 	hammer_mount_t hmp = (void *)mp->mnt_data;
830 	int flags;
831 	int error;
832 
833 	/*
834 	 * Clean out the vnodes
835 	 */
836 	lwkt_gettoken(&hmp->fs_token);
837 	flags = 0;
838 	if (mntflags & MNT_FORCE)
839 		flags |= FORCECLOSE;
840 	error = vflush(mp, 0, flags);
841 
842 	/*
843 	 * Clean up the internal mount structure and related entities.  This
844 	 * may issue I/O.
845 	 */
846 	if (error == 0) {
847 		/* called with fs_token held */
848 		hammer_free_hmp(mp);
849 	} else {
850 		lwkt_reltoken(&hmp->fs_token);
851 	}
852 	return(error);
853 }
854 
855 /*
856  * Clean up the internal mount structure and disassociate it from the mount.
857  * This may issue I/O.
858  *
859  * Called with fs_token held.
860  */
861 static void
862 hammer_free_hmp(struct mount *mp)
863 {
864 	hammer_mount_t hmp = (void *)mp->mnt_data;
865 	hammer_flush_group_t flg;
866 	int count;
867 	int dummy;
868 
869 	/*
870 	 * Flush anything dirty.  This won't even run if the
871 	 * filesystem errored-out.
872 	 */
873 	count = 0;
874 	while (hammer_flusher_haswork(hmp)) {
875 		hammer_flusher_sync(hmp);
876 		++count;
877 		if (count >= 5) {
878 			if (count == 5)
879 				kprintf("HAMMER: umount flushing.");
880 			else
881 				kprintf(".");
882 			tsleep(&dummy, 0, "hmrufl", hz);
883 		}
884 		if (count == 30) {
885 			kprintf("giving up\n");
886 			break;
887 		}
888 	}
889 	if (count >= 5 && count < 30)
890 		kprintf("\n");
891 
892 	/*
893 	 * If the mount had a critical error we have to destroy any
894 	 * remaining inodes before we can finish cleaning up the flusher.
895 	 */
896 	if (hmp->flags & HAMMER_MOUNT_CRITICAL_ERROR) {
897 		RB_SCAN(hammer_ino_rb_tree, &hmp->rb_inos_root, NULL,
898 			hammer_destroy_inode_callback, NULL);
899 	}
900 
901 	/*
902 	 * There shouldn't be any inodes left now and any left over
903 	 * flush groups should now be empty.
904 	 */
905 	KKASSERT(RB_EMPTY(&hmp->rb_inos_root));
906 	while ((flg = TAILQ_FIRST(&hmp->flush_group_list)) != NULL) {
907 		TAILQ_REMOVE(&hmp->flush_group_list, flg, flush_entry);
908 		KKASSERT(RB_EMPTY(&flg->flush_tree));
909 		if (flg->refs) {
910 			kprintf("HAMMER: Warning, flush_group %p was "
911 				"not empty on umount!\n", flg);
912 		}
913 		kfree(flg, hmp->m_misc);
914 	}
915 
916 	/*
917 	 * We can finally destroy the flusher
918 	 */
919 	hammer_flusher_destroy(hmp);
920 
921 	/*
922 	 * We may have held recovered buffers due to a read-only mount.
923 	 * These must be discarded.
924 	 */
925 	if (hmp->ronly)
926 		hammer_recover_flush_buffers(hmp, NULL, -1);
927 
928 	/*
929 	 * Unload buffers and then volumes
930 	 */
931         RB_SCAN(hammer_buf_rb_tree, &hmp->rb_bufs_root, NULL,
932 		hammer_unload_buffer, NULL);
933 	RB_SCAN(hammer_vol_rb_tree, &hmp->rb_vols_root, NULL,
934 		hammer_unload_volume, NULL);
935 
936 	mp->mnt_data = NULL;
937 	mp->mnt_flag &= ~MNT_LOCAL;
938 	hmp->mp = NULL;
939 	hammer_destroy_objid_cache(hmp);
940 	hammer_destroy_dedup_cache(hmp);
941 	if (hmp->dedup_free_cache != NULL) {
942 		kfree(hmp->dedup_free_cache, hmp->m_misc);
943 		hmp->dedup_free_cache = NULL;
944 	}
945 	kmalloc_destroy(&hmp->m_misc);
946 	kmalloc_destroy(&hmp->m_inodes);
947 	lwkt_reltoken(&hmp->fs_token);
948 	kfree(hmp, M_HAMMER);
949 }
950 
951 /*
952  * Report critical errors.  ip may be NULL.
953  */
954 void
955 hammer_critical_error(hammer_mount_t hmp, hammer_inode_t ip,
956 		      int error, const char *msg)
957 {
958 	hmp->flags |= HAMMER_MOUNT_CRITICAL_ERROR;
959 
960 	krateprintf(&hmp->krate,
961 		    "HAMMER(%s): Critical error inode=%jd error=%d %s\n",
962 		    hmp->mp->mnt_stat.f_mntfromname,
963 		    (intmax_t)(ip ? ip->obj_id : -1),
964 		    error, msg);
965 
966 	if (hmp->ronly == 0) {
967 		hmp->ronly = 2;		/* special errored read-only mode */
968 		hmp->mp->mnt_flag |= MNT_RDONLY;
969 		RB_SCAN(hammer_vol_rb_tree, &hmp->rb_vols_root, NULL,
970 			hammer_adjust_volume_mode, NULL);
971 		kprintf("HAMMER(%s): Forcing read-only mode\n",
972 			hmp->mp->mnt_stat.f_mntfromname);
973 	}
974 	hmp->error = error;
975 	if (hammer_debug_critical)
976 		Debugger("Entering debugger");
977 }
978 
979 
980 /*
981  * Obtain a vnode for the specified inode number.  An exclusively locked
982  * vnode is returned.
983  */
984 int
985 hammer_vfs_vget(struct mount *mp, struct vnode *dvp,
986 		ino_t ino, struct vnode **vpp)
987 {
988 	struct hammer_transaction trans;
989 	struct hammer_mount *hmp = (void *)mp->mnt_data;
990 	struct hammer_inode *ip;
991 	int error;
992 	u_int32_t localization;
993 
994 	lwkt_gettoken(&hmp->fs_token);
995 	hammer_simple_transaction(&trans, hmp);
996 
997 	/*
998 	 * If a directory vnode is supplied (mainly NFS) then we can acquire
999 	 * the PFS domain from it.  Otherwise we would only be able to vget
1000 	 * inodes in the root PFS.
1001 	 */
1002 	if (dvp) {
1003 		localization = HAMMER_DEF_LOCALIZATION +
1004 				VTOI(dvp)->obj_localization;
1005 	} else {
1006 		localization = HAMMER_DEF_LOCALIZATION;
1007 	}
1008 
1009 	/*
1010 	 * Lookup the requested HAMMER inode.  The structure must be
1011 	 * left unlocked while we manipulate the related vnode to avoid
1012 	 * a deadlock.
1013 	 */
1014 	ip = hammer_get_inode(&trans, NULL, ino,
1015 			      hmp->asof, localization,
1016 			      0, &error);
1017 	if (ip == NULL) {
1018 		*vpp = NULL;
1019 	} else {
1020 		error = hammer_get_vnode(ip, vpp);
1021 		hammer_rel_inode(ip, 0);
1022 	}
1023 	hammer_done_transaction(&trans);
1024 	lwkt_reltoken(&hmp->fs_token);
1025 	return (error);
1026 }
1027 
1028 /*
1029  * Return the root vnode for the filesystem.
1030  *
1031  * HAMMER stores the root vnode in the hammer_mount structure so
1032  * getting it is easy.
1033  */
1034 static int
1035 hammer_vfs_root(struct mount *mp, struct vnode **vpp)
1036 {
1037 	int error;
1038 
1039 	error = hammer_vfs_vget(mp, NULL, 1, vpp);
1040 	return (error);
1041 }
1042 
1043 static int
1044 hammer_vfs_statfs(struct mount *mp, struct statfs *sbp, struct ucred *cred)
1045 {
1046 	struct hammer_mount *hmp = (void *)mp->mnt_data;
1047 	hammer_volume_t volume;
1048 	hammer_volume_ondisk_t ondisk;
1049 	int error;
1050 	int64_t bfree;
1051 	int64_t breserved;
1052 
1053 	lwkt_gettoken(&hmp->fs_token);
1054 	volume = hammer_get_root_volume(hmp, &error);
1055 	if (error) {
1056 		lwkt_reltoken(&hmp->fs_token);
1057 		return(error);
1058 	}
1059 	ondisk = volume->ondisk;
1060 
1061 	/*
1062 	 * Basic stats
1063 	 */
1064 	_hammer_checkspace(hmp, HAMMER_CHKSPC_WRITE, &breserved);
1065 	mp->mnt_stat.f_files = ondisk->vol0_stat_inodes;
1066 	bfree = ondisk->vol0_stat_freebigblocks * HAMMER_LARGEBLOCK_SIZE;
1067 	hammer_rel_volume(volume, 0);
1068 
1069 	mp->mnt_stat.f_bfree = (bfree - breserved) / HAMMER_BUFSIZE;
1070 	mp->mnt_stat.f_bavail = mp->mnt_stat.f_bfree;
1071 	if (mp->mnt_stat.f_files < 0)
1072 		mp->mnt_stat.f_files = 0;
1073 
1074 	*sbp = mp->mnt_stat;
1075 	lwkt_reltoken(&hmp->fs_token);
1076 	return(0);
1077 }
1078 
1079 static int
1080 hammer_vfs_statvfs(struct mount *mp, struct statvfs *sbp, struct ucred *cred)
1081 {
1082 	struct hammer_mount *hmp = (void *)mp->mnt_data;
1083 	hammer_volume_t volume;
1084 	hammer_volume_ondisk_t ondisk;
1085 	int error;
1086 	int64_t bfree;
1087 	int64_t breserved;
1088 
1089 	lwkt_gettoken(&hmp->fs_token);
1090 	volume = hammer_get_root_volume(hmp, &error);
1091 	if (error) {
1092 		lwkt_reltoken(&hmp->fs_token);
1093 		return(error);
1094 	}
1095 	ondisk = volume->ondisk;
1096 
1097 	/*
1098 	 * Basic stats
1099 	 */
1100 	_hammer_checkspace(hmp, HAMMER_CHKSPC_WRITE, &breserved);
1101 	mp->mnt_vstat.f_files = ondisk->vol0_stat_inodes;
1102 	bfree = ondisk->vol0_stat_freebigblocks * HAMMER_LARGEBLOCK_SIZE;
1103 	hammer_rel_volume(volume, 0);
1104 
1105 	mp->mnt_vstat.f_bfree = (bfree - breserved) / HAMMER_BUFSIZE;
1106 	mp->mnt_vstat.f_bavail = mp->mnt_vstat.f_bfree;
1107 	if (mp->mnt_vstat.f_files < 0)
1108 		mp->mnt_vstat.f_files = 0;
1109 	*sbp = mp->mnt_vstat;
1110 	lwkt_reltoken(&hmp->fs_token);
1111 	return(0);
1112 }
1113 
1114 /*
1115  * Sync the filesystem.  Currently we have to run it twice, the second
1116  * one will advance the undo start index to the end index, so if a crash
1117  * occurs no undos will be run on mount.
1118  *
1119  * We do not sync the filesystem if we are called from a panic.  If we did
1120  * we might end up blowing up a sync that was already in progress.
1121  */
1122 static int
1123 hammer_vfs_sync(struct mount *mp, int waitfor)
1124 {
1125 	struct hammer_mount *hmp = (void *)mp->mnt_data;
1126 	int error;
1127 
1128 	lwkt_gettoken(&hmp->fs_token);
1129 	if (panicstr == NULL) {
1130 		error = hammer_sync_hmp(hmp, waitfor);
1131 	} else {
1132 		error = EIO;
1133 	}
1134 	lwkt_reltoken(&hmp->fs_token);
1135 	return (error);
1136 }
1137 
1138 /*
1139  * Convert a vnode to a file handle.
1140  *
1141  * Accesses read-only fields on already-referenced structures so
1142  * no token is needed.
1143  */
1144 static int
1145 hammer_vfs_vptofh(struct vnode *vp, struct fid *fhp)
1146 {
1147 	hammer_inode_t ip;
1148 
1149 	KKASSERT(MAXFIDSZ >= 16);
1150 	ip = VTOI(vp);
1151 	fhp->fid_len = offsetof(struct fid, fid_data[16]);
1152 	fhp->fid_ext = ip->obj_localization >> 16;
1153 	bcopy(&ip->obj_id, fhp->fid_data + 0, sizeof(ip->obj_id));
1154 	bcopy(&ip->obj_asof, fhp->fid_data + 8, sizeof(ip->obj_asof));
1155 	return(0);
1156 }
1157 
1158 
1159 /*
1160  * Convert a file handle back to a vnode.
1161  *
1162  * Use rootvp to enforce PFS isolation when a PFS is exported via a
1163  * null mount.
1164  */
1165 static int
1166 hammer_vfs_fhtovp(struct mount *mp, struct vnode *rootvp,
1167 		  struct fid *fhp, struct vnode **vpp)
1168 {
1169 	hammer_mount_t hmp = (void *)mp->mnt_data;
1170 	struct hammer_transaction trans;
1171 	struct hammer_inode *ip;
1172 	struct hammer_inode_info info;
1173 	int error;
1174 	u_int32_t localization;
1175 
1176 	bcopy(fhp->fid_data + 0, &info.obj_id, sizeof(info.obj_id));
1177 	bcopy(fhp->fid_data + 8, &info.obj_asof, sizeof(info.obj_asof));
1178 	if (rootvp)
1179 		localization = VTOI(rootvp)->obj_localization;
1180 	else
1181 		localization = (u_int32_t)fhp->fid_ext << 16;
1182 
1183 	lwkt_gettoken(&hmp->fs_token);
1184 	hammer_simple_transaction(&trans, hmp);
1185 
1186 	/*
1187 	 * Get/allocate the hammer_inode structure.  The structure must be
1188 	 * unlocked while we manipulate the related vnode to avoid a
1189 	 * deadlock.
1190 	 */
1191 	ip = hammer_get_inode(&trans, NULL, info.obj_id,
1192 			      info.obj_asof, localization, 0, &error);
1193 	if (ip) {
1194 		error = hammer_get_vnode(ip, vpp);
1195 		hammer_rel_inode(ip, 0);
1196 	} else {
1197 		*vpp = NULL;
1198 	}
1199 	hammer_done_transaction(&trans);
1200 	lwkt_reltoken(&hmp->fs_token);
1201 	return (error);
1202 }
1203 
1204 static int
1205 hammer_vfs_checkexp(struct mount *mp, struct sockaddr *nam,
1206 		    int *exflagsp, struct ucred **credanonp)
1207 {
1208 	hammer_mount_t hmp = (void *)mp->mnt_data;
1209 	struct netcred *np;
1210 	int error;
1211 
1212 	lwkt_gettoken(&hmp->fs_token);
1213 	np = vfs_export_lookup(mp, &hmp->export, nam);
1214 	if (np) {
1215 		*exflagsp = np->netc_exflags;
1216 		*credanonp = &np->netc_anon;
1217 		error = 0;
1218 	} else {
1219 		error = EACCES;
1220 	}
1221 	lwkt_reltoken(&hmp->fs_token);
1222 	return (error);
1223 
1224 }
1225 
1226 int
1227 hammer_vfs_export(struct mount *mp, int op, const struct export_args *export)
1228 {
1229 	hammer_mount_t hmp = (void *)mp->mnt_data;
1230 	int error;
1231 
1232 	lwkt_gettoken(&hmp->fs_token);
1233 
1234 	switch(op) {
1235 	case MOUNTCTL_SET_EXPORT:
1236 		error = vfs_export(mp, &hmp->export, export);
1237 		break;
1238 	default:
1239 		error = EOPNOTSUPP;
1240 		break;
1241 	}
1242 	lwkt_reltoken(&hmp->fs_token);
1243 
1244 	return(error);
1245 }
1246 
1247