xref: /dragonfly/sys/vfs/hammer2/hammer2_vfsops.c (revision fcf6efef)
1 /*
2  * Copyright (c) 2011-2018 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  * by Daniel Flores (GSOC 2013 - mentored by Matthew Dillon, compression)
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in
16  *    the documentation and/or other materials provided with the
17  *    distribution.
18  * 3. Neither the name of The DragonFly Project nor the names of its
19  *    contributors may be used to endorse or promote products derived
20  *    from this software without specific, prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
23  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
24  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
25  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
26  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
27  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
28  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
29  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
30  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
31  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
32  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/kernel.h>
38 #include <sys/nlookup.h>
39 #include <sys/vnode.h>
40 #include <sys/mount.h>
41 #include <sys/fcntl.h>
42 #include <sys/buf.h>
43 #include <sys/uuid.h>
44 #include <sys/vfsops.h>
45 #include <sys/sysctl.h>
46 #include <sys/socket.h>
47 #include <sys/objcache.h>
48 
49 #include <sys/proc.h>
50 #include <sys/namei.h>
51 #include <sys/mountctl.h>
52 #include <sys/dirent.h>
53 #include <sys/uio.h>
54 
55 #include <sys/mutex.h>
56 #include <sys/mutex2.h>
57 
58 #include "hammer2.h"
59 #include "hammer2_disk.h"
60 #include "hammer2_mount.h"
61 #include "hammer2_lz4.h"
62 
63 #include "zlib/hammer2_zlib.h"
64 
65 #define REPORT_REFS_ERRORS 1	/* XXX remove me */
66 
67 MALLOC_DEFINE(M_OBJCACHE, "objcache", "Object Cache");
68 
69 struct hammer2_sync_info {
70 	int error;
71 	int waitfor;
72 	int pass;
73 };
74 
75 TAILQ_HEAD(hammer2_mntlist, hammer2_dev);
76 static struct hammer2_mntlist hammer2_mntlist;
77 
78 struct hammer2_pfslist hammer2_pfslist;
79 struct hammer2_pfslist hammer2_spmplist;
80 struct lock hammer2_mntlk;
81 
82 int hammer2_supported_version = HAMMER2_VOL_VERSION_DEFAULT;
83 int hammer2_debug;
84 long hammer2_debug_inode;
85 int hammer2_cluster_meta_read = 1;	/* physical read-ahead */
86 int hammer2_cluster_data_read = 4;	/* physical read-ahead */
87 int hammer2_cluster_write = 0;		/* physical write clustering */
88 int hammer2_dedup_enable = 1;
89 int hammer2_always_compress = 0;	/* always try to compress */
90 int hammer2_inval_enable = 0;
91 int hammer2_flush_pipe = 100;
92 int hammer2_dio_count;
93 int hammer2_dio_limit = 256;
94 int hammer2_bulkfree_tps = 5000;
95 long hammer2_chain_allocs;
96 long hammer2_chain_frees;
97 long hammer2_limit_dirty_chains;
98 long hammer2_limit_dirty_inodes;
99 long hammer2_count_modified_chains;
100 long hammer2_iod_invals;
101 long hammer2_iod_file_read;
102 long hammer2_iod_meta_read;
103 long hammer2_iod_indr_read;
104 long hammer2_iod_fmap_read;
105 long hammer2_iod_volu_read;
106 long hammer2_iod_file_write;
107 long hammer2_iod_file_wembed;
108 long hammer2_iod_file_wzero;
109 long hammer2_iod_file_wdedup;
110 long hammer2_iod_meta_write;
111 long hammer2_iod_indr_write;
112 long hammer2_iod_fmap_write;
113 long hammer2_iod_volu_write;
114 long hammer2_iod_inode_creates;
115 long hammer2_iod_inode_deletes;
116 
117 MALLOC_DECLARE(M_HAMMER2_CBUFFER);
118 MALLOC_DEFINE(M_HAMMER2_CBUFFER, "HAMMER2-compbuffer",
119 		"Buffer used for compression.");
120 
121 MALLOC_DECLARE(M_HAMMER2_DEBUFFER);
122 MALLOC_DEFINE(M_HAMMER2_DEBUFFER, "HAMMER2-decompbuffer",
123 		"Buffer used for decompression.");
124 
125 SYSCTL_NODE(_vfs, OID_AUTO, hammer2, CTLFLAG_RW, 0, "HAMMER2 filesystem");
126 
127 SYSCTL_INT(_vfs_hammer2, OID_AUTO, supported_version, CTLFLAG_RD,
128 	   &hammer2_supported_version, 0, "");
129 SYSCTL_INT(_vfs_hammer2, OID_AUTO, debug, CTLFLAG_RW,
130 	   &hammer2_debug, 0, "");
131 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, debug_inode, CTLFLAG_RW,
132 	   &hammer2_debug_inode, 0, "");
133 SYSCTL_INT(_vfs_hammer2, OID_AUTO, cluster_meta_read, CTLFLAG_RW,
134 	   &hammer2_cluster_meta_read, 0, "");
135 SYSCTL_INT(_vfs_hammer2, OID_AUTO, cluster_data_read, CTLFLAG_RW,
136 	   &hammer2_cluster_data_read, 0, "");
137 SYSCTL_INT(_vfs_hammer2, OID_AUTO, cluster_write, CTLFLAG_RW,
138 	   &hammer2_cluster_write, 0, "");
139 SYSCTL_INT(_vfs_hammer2, OID_AUTO, dedup_enable, CTLFLAG_RW,
140 	   &hammer2_dedup_enable, 0, "");
141 SYSCTL_INT(_vfs_hammer2, OID_AUTO, always_compress, CTLFLAG_RW,
142 	   &hammer2_always_compress, 0, "");
143 SYSCTL_INT(_vfs_hammer2, OID_AUTO, inval_enable, CTLFLAG_RW,
144 	   &hammer2_inval_enable, 0, "");
145 SYSCTL_INT(_vfs_hammer2, OID_AUTO, flush_pipe, CTLFLAG_RW,
146 	   &hammer2_flush_pipe, 0, "");
147 SYSCTL_INT(_vfs_hammer2, OID_AUTO, bulkfree_tps, CTLFLAG_RW,
148 	   &hammer2_bulkfree_tps, 0, "");
149 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, chain_allocs, CTLFLAG_RW,
150 	   &hammer2_chain_allocs, 0, "");
151 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, chain_frees, CTLFLAG_RW,
152 	   &hammer2_chain_frees, 0, "");
153 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, limit_dirty_chains, CTLFLAG_RW,
154 	   &hammer2_limit_dirty_chains, 0, "");
155 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, limit_dirty_inodes, CTLFLAG_RW,
156 	   &hammer2_limit_dirty_inodes, 0, "");
157 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, count_modified_chains, CTLFLAG_RW,
158 	   &hammer2_count_modified_chains, 0, "");
159 SYSCTL_INT(_vfs_hammer2, OID_AUTO, dio_count, CTLFLAG_RD,
160 	   &hammer2_dio_count, 0, "");
161 SYSCTL_INT(_vfs_hammer2, OID_AUTO, dio_limit, CTLFLAG_RW,
162 	   &hammer2_dio_limit, 0, "");
163 
164 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_invals, CTLFLAG_RW,
165 	   &hammer2_iod_invals, 0, "");
166 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_file_read, CTLFLAG_RW,
167 	   &hammer2_iod_file_read, 0, "");
168 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_meta_read, CTLFLAG_RW,
169 	   &hammer2_iod_meta_read, 0, "");
170 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_indr_read, CTLFLAG_RW,
171 	   &hammer2_iod_indr_read, 0, "");
172 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_fmap_read, CTLFLAG_RW,
173 	   &hammer2_iod_fmap_read, 0, "");
174 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_volu_read, CTLFLAG_RW,
175 	   &hammer2_iod_volu_read, 0, "");
176 
177 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_file_write, CTLFLAG_RW,
178 	   &hammer2_iod_file_write, 0, "");
179 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_file_wembed, CTLFLAG_RW,
180 	   &hammer2_iod_file_wembed, 0, "");
181 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_file_wzero, CTLFLAG_RW,
182 	   &hammer2_iod_file_wzero, 0, "");
183 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_file_wdedup, CTLFLAG_RW,
184 	   &hammer2_iod_file_wdedup, 0, "");
185 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_meta_write, CTLFLAG_RW,
186 	   &hammer2_iod_meta_write, 0, "");
187 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_indr_write, CTLFLAG_RW,
188 	   &hammer2_iod_indr_write, 0, "");
189 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_fmap_write, CTLFLAG_RW,
190 	   &hammer2_iod_fmap_write, 0, "");
191 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_volu_write, CTLFLAG_RW,
192 	   &hammer2_iod_volu_write, 0, "");
193 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_inode_creates, CTLFLAG_RW,
194 	   &hammer2_iod_inode_creates, 0, "");
195 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_inode_deletes, CTLFLAG_RW,
196 	   &hammer2_iod_inode_deletes, 0, "");
197 
198 long hammer2_process_icrc32;
199 long hammer2_process_xxhash64;
200 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, process_icrc32, CTLFLAG_RW,
201 	   &hammer2_process_icrc32, 0, "");
202 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, process_xxhash64, CTLFLAG_RW,
203 	   &hammer2_process_xxhash64, 0, "");
204 
205 static int hammer2_vfs_init(struct vfsconf *conf);
206 static int hammer2_vfs_uninit(struct vfsconf *vfsp);
207 static int hammer2_vfs_mount(struct mount *mp, char *path, caddr_t data,
208 				struct ucred *cred);
209 static int hammer2_remount(hammer2_dev_t *, struct mount *, char *,
210 				struct vnode *, struct ucred *);
211 static int hammer2_recovery(hammer2_dev_t *hmp);
212 static int hammer2_vfs_unmount(struct mount *mp, int mntflags);
213 static int hammer2_vfs_root(struct mount *mp, struct vnode **vpp);
214 static int hammer2_vfs_statfs(struct mount *mp, struct statfs *sbp,
215 				struct ucred *cred);
216 static int hammer2_vfs_statvfs(struct mount *mp, struct statvfs *sbp,
217 				struct ucred *cred);
218 static int hammer2_vfs_fhtovp(struct mount *mp, struct vnode *rootvp,
219 				struct fid *fhp, struct vnode **vpp);
220 static int hammer2_vfs_vptofh(struct vnode *vp, struct fid *fhp);
221 static int hammer2_vfs_checkexp(struct mount *mp, struct sockaddr *nam,
222 				int *exflagsp, struct ucred **credanonp);
223 static void hammer2_vfs_modifying(struct mount *mp);
224 
225 static int hammer2_install_volume_header(hammer2_dev_t *hmp);
226 #if 0
227 static int hammer2_sync_scan2(struct mount *mp, struct vnode *vp, void *data);
228 #endif
229 
230 static void hammer2_update_pmps(hammer2_dev_t *hmp);
231 
232 static void hammer2_mount_helper(struct mount *mp, hammer2_pfs_t *pmp);
233 static void hammer2_unmount_helper(struct mount *mp, hammer2_pfs_t *pmp,
234 				hammer2_dev_t *hmp);
235 static int hammer2_fixup_pfses(hammer2_dev_t *hmp);
236 
237 /*
238  * HAMMER2 vfs operations.
239  */
240 static struct vfsops hammer2_vfsops = {
241 	.vfs_init	= hammer2_vfs_init,
242 	.vfs_uninit	= hammer2_vfs_uninit,
243 	.vfs_sync	= hammer2_vfs_sync,
244 	.vfs_mount	= hammer2_vfs_mount,
245 	.vfs_unmount	= hammer2_vfs_unmount,
246 	.vfs_root 	= hammer2_vfs_root,
247 	.vfs_statfs	= hammer2_vfs_statfs,
248 	.vfs_statvfs	= hammer2_vfs_statvfs,
249 	.vfs_vget	= hammer2_vfs_vget,
250 	.vfs_vptofh	= hammer2_vfs_vptofh,
251 	.vfs_fhtovp	= hammer2_vfs_fhtovp,
252 	.vfs_checkexp	= hammer2_vfs_checkexp,
253 	.vfs_modifying	= hammer2_vfs_modifying
254 };
255 
256 MALLOC_DEFINE(M_HAMMER2, "HAMMER2-mount", "");
257 
258 VFS_SET(hammer2_vfsops, hammer2, VFCF_MPSAFE);
259 MODULE_VERSION(hammer2, 1);
260 
261 static
262 int
263 hammer2_vfs_init(struct vfsconf *conf)
264 {
265 	static struct objcache_malloc_args margs_read;
266 	static struct objcache_malloc_args margs_write;
267 	static struct objcache_malloc_args margs_vop;
268 
269 	int error;
270 
271 	error = 0;
272 	kmalloc_raise_limit(M_HAMMER2, 0);	/* unlimited */
273 
274 	/*
275 	 * A large DIO cache is needed to retain dedup enablement masks.
276 	 * The bulkfree code clears related masks as part of the disk block
277 	 * recycling algorithm, preventing it from being used for a later
278 	 * dedup.
279 	 *
280 	 * NOTE: A large buffer cache can actually interfere with dedup
281 	 *	 operation because we dedup based on media physical buffers
282 	 *	 and not logical buffers.  Try to make the DIO case large
283 	 *	 enough to avoid this problem, but also cap it.
284 	 */
285 	hammer2_dio_limit = nbuf * 2;
286 	if (hammer2_dio_limit > 100000)
287 		hammer2_dio_limit = 100000;
288 
289 	if (HAMMER2_BLOCKREF_BYTES != sizeof(struct hammer2_blockref))
290 		error = EINVAL;
291 	if (HAMMER2_INODE_BYTES != sizeof(struct hammer2_inode_data))
292 		error = EINVAL;
293 	if (HAMMER2_VOLUME_BYTES != sizeof(struct hammer2_volume_data))
294 		error = EINVAL;
295 
296 	if (error)
297 		kprintf("HAMMER2 structure size mismatch; cannot continue.\n");
298 
299 	margs_read.objsize = 65536;
300 	margs_read.mtype = M_HAMMER2_DEBUFFER;
301 
302 	margs_write.objsize = 32768;
303 	margs_write.mtype = M_HAMMER2_CBUFFER;
304 
305 	margs_vop.objsize = sizeof(hammer2_xop_t);
306 	margs_vop.mtype = M_HAMMER2;
307 
308 	/*
309 	 * Note thaht for the XOPS cache we want backing store allocations
310 	 * to use M_ZERO.  This is not allowed in objcache_get() (to avoid
311 	 * confusion), so use the backing store function that does it.  This
312 	 * means that initial XOPS objects are zerod but REUSED objects are
313 	 * not.  So we are responsible for cleaning the object up sufficiently
314 	 * for our needs before objcache_put()ing it back (typically just the
315 	 * FIFO indices).
316 	 */
317 	cache_buffer_read = objcache_create(margs_read.mtype->ks_shortdesc,
318 				0, 1, NULL, NULL, NULL,
319 				objcache_malloc_alloc,
320 				objcache_malloc_free,
321 				&margs_read);
322 	cache_buffer_write = objcache_create(margs_write.mtype->ks_shortdesc,
323 				0, 1, NULL, NULL, NULL,
324 				objcache_malloc_alloc,
325 				objcache_malloc_free,
326 				&margs_write);
327 	cache_xops = objcache_create(margs_vop.mtype->ks_shortdesc,
328 				0, 1, NULL, NULL, NULL,
329 				objcache_malloc_alloc_zero,
330 				objcache_malloc_free,
331 				&margs_vop);
332 
333 
334 	lockinit(&hammer2_mntlk, "mntlk", 0, 0);
335 	TAILQ_INIT(&hammer2_mntlist);
336 	TAILQ_INIT(&hammer2_pfslist);
337 	TAILQ_INIT(&hammer2_spmplist);
338 
339 	hammer2_limit_dirty_chains = maxvnodes / 10;
340 	if (hammer2_limit_dirty_chains > HAMMER2_LIMIT_DIRTY_CHAINS)
341 		hammer2_limit_dirty_chains = HAMMER2_LIMIT_DIRTY_CHAINS;
342 	if (hammer2_limit_dirty_chains < 1000)
343 		hammer2_limit_dirty_chains = 1000;
344 
345 	hammer2_limit_dirty_inodes = maxvnodes / 25;
346 	if (hammer2_limit_dirty_inodes < 100)
347 		hammer2_limit_dirty_inodes = 100;
348 	if (hammer2_limit_dirty_inodes > HAMMER2_LIMIT_DIRTY_INODES)
349 		hammer2_limit_dirty_inodes = HAMMER2_LIMIT_DIRTY_INODES;
350 
351 	return (error);
352 }
353 
354 static
355 int
356 hammer2_vfs_uninit(struct vfsconf *vfsp __unused)
357 {
358 	objcache_destroy(cache_buffer_read);
359 	objcache_destroy(cache_buffer_write);
360 	objcache_destroy(cache_xops);
361 	return 0;
362 }
363 
364 /*
365  * Core PFS allocator.  Used to allocate or reference the pmp structure
366  * for PFS cluster mounts and the spmp structure for media (hmp) structures.
367  * The pmp can be passed in or loaded by this function using the chain and
368  * inode data.
369  *
370  * pmp->modify_tid tracks new modify_tid transaction ids for front-end
371  * transactions.  Note that synchronization does not use this field.
372  * (typically frontend operations and synchronization cannot run on the
373  * same PFS node at the same time).
374  *
375  * XXX check locking
376  */
377 hammer2_pfs_t *
378 hammer2_pfsalloc(hammer2_chain_t *chain,
379 		 const hammer2_inode_data_t *ripdata,
380 		 hammer2_tid_t modify_tid, hammer2_dev_t *force_local)
381 {
382 	hammer2_pfs_t *pmp;
383 	hammer2_inode_t *iroot;
384 	int count;
385 	int i;
386 	int j;
387 
388 	pmp = NULL;
389 
390 	/*
391 	 * Locate or create the PFS based on the cluster id.  If ripdata
392 	 * is NULL this is a spmp which is unique and is always allocated.
393 	 *
394 	 * If the device is mounted in local mode all PFSs are considered
395 	 * independent and not part of any cluster (for debugging only).
396 	 */
397 	if (ripdata) {
398 		TAILQ_FOREACH(pmp, &hammer2_pfslist, mntentry) {
399 			if (force_local != pmp->force_local)
400 				continue;
401 			if (force_local == NULL &&
402 			    bcmp(&pmp->pfs_clid, &ripdata->meta.pfs_clid,
403 				 sizeof(pmp->pfs_clid)) == 0) {
404 					break;
405 			} else if (force_local && pmp->pfs_names[0] &&
406 			    strcmp(pmp->pfs_names[0], ripdata->filename) == 0) {
407 					break;
408 			}
409 		}
410 	}
411 
412 	if (pmp == NULL) {
413 		pmp = kmalloc(sizeof(*pmp), M_HAMMER2, M_WAITOK | M_ZERO);
414 		pmp->force_local = force_local;
415 		hammer2_trans_manage_init(pmp);
416 		kmalloc_create(&pmp->minode, "HAMMER2-inodes");
417 		kmalloc_create(&pmp->mmsg, "HAMMER2-pfsmsg");
418 		lockinit(&pmp->lock, "pfslk", 0, 0);
419 		lockinit(&pmp->lock_nlink, "h2nlink", 0, 0);
420 		spin_init(&pmp->inum_spin, "hm2pfsalloc_inum");
421 		spin_init(&pmp->xop_spin, "h2xop");
422 		spin_init(&pmp->lru_spin, "h2lru");
423 		RB_INIT(&pmp->inum_tree);
424 		TAILQ_INIT(&pmp->syncq);
425 		TAILQ_INIT(&pmp->depq);
426 		TAILQ_INIT(&pmp->lru_list);
427 		spin_init(&pmp->list_spin, "h2pfsalloc_list");
428 
429 		/*
430 		 * Distribute backend operations to threads
431 		 */
432 		for (i = 0; i < HAMMER2_XOPGROUPS; ++i)
433 			hammer2_xop_group_init(pmp, &pmp->xop_groups[i]);
434 
435 		/*
436 		 * Save the last media transaction id for the flusher.  Set
437 		 * initial
438 		 */
439 		if (ripdata) {
440 			pmp->pfs_clid = ripdata->meta.pfs_clid;
441 			TAILQ_INSERT_TAIL(&hammer2_pfslist, pmp, mntentry);
442 		} else {
443 			pmp->flags |= HAMMER2_PMPF_SPMP;
444 			TAILQ_INSERT_TAIL(&hammer2_spmplist, pmp, mntentry);
445 		}
446 
447 		/*
448 		 * The synchronization thread may start too early, make
449 		 * sure it stays frozen until we are ready to let it go.
450 		 * XXX
451 		 */
452 		/*
453 		pmp->primary_thr.flags = HAMMER2_THREAD_FROZEN |
454 					 HAMMER2_THREAD_REMASTER;
455 		*/
456 	}
457 
458 	/*
459 	 * Create the PFS's root inode and any missing XOP helper threads.
460 	 */
461 	if ((iroot = pmp->iroot) == NULL) {
462 		iroot = hammer2_inode_get(pmp, NULL, 1, -1);
463 		if (ripdata)
464 			iroot->meta = ripdata->meta;
465 		pmp->iroot = iroot;
466 		hammer2_inode_ref(iroot);
467 		hammer2_inode_unlock(iroot);
468 	}
469 
470 	/*
471 	 * Stop here if no chain is passed in.
472 	 */
473 	if (chain == NULL)
474 		goto done;
475 
476 	/*
477 	 * When a chain is passed in we must add it to the PFS's root
478 	 * inode, update pmp->pfs_types[], and update the syncronization
479 	 * threads.
480 	 *
481 	 * When forcing local mode, mark the PFS as a MASTER regardless.
482 	 *
483 	 * At the moment empty spots can develop due to removals or failures.
484 	 * Ultimately we want to re-fill these spots but doing so might
485 	 * confused running code. XXX
486 	 */
487 	hammer2_inode_ref(iroot);
488 	hammer2_mtx_ex(&iroot->lock);
489 	j = iroot->cluster.nchains;
490 
491 	if (j == HAMMER2_MAXCLUSTER) {
492 		kprintf("hammer2_mount: cluster full!\n");
493 		/* XXX fatal error? */
494 	} else {
495 		KKASSERT(chain->pmp == NULL);
496 		chain->pmp = pmp;
497 		hammer2_chain_ref(chain);
498 		iroot->cluster.array[j].chain = chain;
499 		if (force_local)
500 			pmp->pfs_types[j] = HAMMER2_PFSTYPE_MASTER;
501 		else
502 			pmp->pfs_types[j] = ripdata->meta.pfs_type;
503 		pmp->pfs_names[j] = kstrdup(ripdata->filename, M_HAMMER2);
504 		pmp->pfs_hmps[j] = chain->hmp;
505 		hammer2_spin_ex(&pmp->inum_spin);
506 		pmp->pfs_iroot_blocksets[j] = chain->data->ipdata.u.blockset;
507 		hammer2_spin_unex(&pmp->inum_spin);
508 
509 		/*
510 		 * If the PFS is already mounted we must account
511 		 * for the mount_count here.
512 		 */
513 		if (pmp->mp)
514 			++chain->hmp->mount_count;
515 
516 		/*
517 		 * May have to fixup dirty chain tracking.  Previous
518 		 * pmp was NULL so nothing to undo.
519 		 */
520 		if (chain->flags & HAMMER2_CHAIN_MODIFIED)
521 			hammer2_pfs_memory_inc(pmp);
522 		++j;
523 	}
524 	iroot->cluster.nchains = j;
525 
526 	/*
527 	 * Update nmasters from any PFS inode which is part of the cluster.
528 	 * It is possible that this will result in a value which is too
529 	 * high.  MASTER PFSs are authoritative for pfs_nmasters and will
530 	 * override this value later on.
531 	 *
532 	 * (This informs us of masters that might not currently be
533 	 *  discoverable by this mount).
534 	 */
535 	if (ripdata && pmp->pfs_nmasters < ripdata->meta.pfs_nmasters) {
536 		pmp->pfs_nmasters = ripdata->meta.pfs_nmasters;
537 	}
538 
539 	/*
540 	 * Count visible masters.  Masters are usually added with
541 	 * ripdata->meta.pfs_nmasters set to 1.  This detects when there
542 	 * are more (XXX and must update the master inodes).
543 	 */
544 	count = 0;
545 	for (i = 0; i < iroot->cluster.nchains; ++i) {
546 		if (pmp->pfs_types[i] == HAMMER2_PFSTYPE_MASTER)
547 			++count;
548 	}
549 	if (pmp->pfs_nmasters < count)
550 		pmp->pfs_nmasters = count;
551 
552 	/*
553 	 * Create missing synchronization and support threads.
554 	 *
555 	 * Single-node masters (including snapshots) have nothing to
556 	 * synchronize and do not require this thread.
557 	 *
558 	 * Multi-node masters or any number of soft masters, slaves, copy,
559 	 * or other PFS types need the thread.
560 	 *
561 	 * Each thread is responsible for its particular cluster index.
562 	 * We use independent threads so stalls or mismatches related to
563 	 * any given target do not affect other targets.
564 	 */
565 	for (i = 0; i < iroot->cluster.nchains; ++i) {
566 		/*
567 		 * Single-node masters (including snapshots) have nothing
568 		 * to synchronize and will make direct xops support calls,
569 		 * thus they do not require this thread.
570 		 *
571 		 * Note that there can be thousands of snapshots.  We do not
572 		 * want to create thousands of threads.
573 		 */
574 		if (pmp->pfs_nmasters <= 1 &&
575 		    pmp->pfs_types[i] == HAMMER2_PFSTYPE_MASTER) {
576 			continue;
577 		}
578 
579 		/*
580 		 * Sync support thread
581 		 */
582 		if (pmp->sync_thrs[i].td == NULL) {
583 			hammer2_thr_create(&pmp->sync_thrs[i], pmp, NULL,
584 					   "h2nod", i, -1,
585 					   hammer2_primary_sync_thread);
586 		}
587 	}
588 
589 	/*
590 	 * Create missing Xop threads
591 	 *
592 	 * NOTE: We create helper threads for all mounted PFSs or any
593 	 *	 PFSs with 2+ nodes (so the sync thread can update them,
594 	 *	 even if not mounted).
595 	 */
596 	if (pmp->mp || iroot->cluster.nchains >= 2)
597 		hammer2_xop_helper_create(pmp);
598 
599 	hammer2_mtx_unlock(&iroot->lock);
600 	hammer2_inode_drop(iroot);
601 done:
602 	return pmp;
603 }
604 
605 /*
606  * Deallocate an element of a probed PFS.  If destroying and this is a
607  * MASTER, adjust nmasters.
608  *
609  * This function does not physically destroy the PFS element in its device
610  * under the super-root  (see hammer2_ioctl_pfs_delete()).
611  */
612 void
613 hammer2_pfsdealloc(hammer2_pfs_t *pmp, int clindex, int destroying)
614 {
615 	hammer2_inode_t *iroot;
616 	hammer2_chain_t *chain;
617 	int j;
618 
619 	/*
620 	 * Cleanup our reference on iroot.  iroot is (should) not be needed
621 	 * by the flush code.
622 	 */
623 	iroot = pmp->iroot;
624 	if (iroot) {
625 		/*
626 		 * Stop synchronizing
627 		 *
628 		 * XXX flush after acquiring the iroot lock.
629 		 * XXX clean out the cluster index from all inode structures.
630 		 */
631 		hammer2_thr_delete(&pmp->sync_thrs[clindex]);
632 
633 		/*
634 		 * Remove the cluster index from the group.  If destroying
635 		 * the PFS and this is a master, adjust pfs_nmasters.
636 		 */
637 		hammer2_mtx_ex(&iroot->lock);
638 		chain = iroot->cluster.array[clindex].chain;
639 		iroot->cluster.array[clindex].chain = NULL;
640 
641 		switch(pmp->pfs_types[clindex]) {
642 		case HAMMER2_PFSTYPE_MASTER:
643 			if (destroying && pmp->pfs_nmasters > 0)
644 				--pmp->pfs_nmasters;
645 			/* XXX adjust ripdata->meta.pfs_nmasters */
646 			break;
647 		default:
648 			break;
649 		}
650 		pmp->pfs_types[clindex] = HAMMER2_PFSTYPE_NONE;
651 
652 		hammer2_mtx_unlock(&iroot->lock);
653 
654 		/*
655 		 * Release the chain.
656 		 */
657 		if (chain) {
658 			atomic_set_int(&chain->flags, HAMMER2_CHAIN_RELEASE);
659 			hammer2_chain_drop(chain);
660 		}
661 
662 		/*
663 		 * Terminate all XOP threads for the cluster index.
664 		 */
665 		for (j = 0; j < HAMMER2_XOPGROUPS; ++j)
666 			hammer2_thr_delete(&pmp->xop_groups[j].thrs[clindex]);
667 	}
668 }
669 
670 /*
671  * Destroy a PFS, typically only occurs after the last mount on a device
672  * has gone away.
673  */
674 static void
675 hammer2_pfsfree(hammer2_pfs_t *pmp)
676 {
677 	hammer2_inode_t *iroot;
678 	hammer2_chain_t *chain;
679 	int chains_still_present = 0;
680 	int i;
681 	int j;
682 
683 	/*
684 	 * Cleanup our reference on iroot.  iroot is (should) not be needed
685 	 * by the flush code.
686 	 */
687 	if (pmp->flags & HAMMER2_PMPF_SPMP)
688 		TAILQ_REMOVE(&hammer2_spmplist, pmp, mntentry);
689 	else
690 		TAILQ_REMOVE(&hammer2_pfslist, pmp, mntentry);
691 
692 	/*
693 	 * Cleanup chains remaining on LRU list.
694 	 */
695 	hammer2_spin_ex(&pmp->lru_spin);
696 	while ((chain = TAILQ_FIRST(&pmp->lru_list)) != NULL) {
697 		KKASSERT(chain->flags & HAMMER2_CHAIN_ONLRU);
698 		atomic_add_int(&pmp->lru_count, -1);
699 		atomic_clear_int(&chain->flags, HAMMER2_CHAIN_ONLRU);
700 		TAILQ_REMOVE(&pmp->lru_list, chain, lru_node);
701 		hammer2_chain_ref(chain);
702 		hammer2_spin_unex(&pmp->lru_spin);
703 		atomic_set_int(&chain->flags, HAMMER2_CHAIN_RELEASE);
704 		hammer2_chain_drop(chain);
705 		hammer2_spin_ex(&pmp->lru_spin);
706 	}
707 	hammer2_spin_unex(&pmp->lru_spin);
708 
709 	/*
710 	 * Clean up iroot
711 	 */
712 	iroot = pmp->iroot;
713 	if (iroot) {
714 		for (i = 0; i < iroot->cluster.nchains; ++i) {
715 			hammer2_thr_delete(&pmp->sync_thrs[i]);
716 			for (j = 0; j < HAMMER2_XOPGROUPS; ++j)
717 				hammer2_thr_delete(&pmp->xop_groups[j].thrs[i]);
718 			chain = iroot->cluster.array[i].chain;
719 			if (chain && !RB_EMPTY(&chain->core.rbtree)) {
720 				kprintf("hammer2: Warning pmp %p still "
721 					"has active chains\n", pmp);
722 				chains_still_present = 1;
723 			}
724 		}
725 #if REPORT_REFS_ERRORS
726 		if (iroot->refs != 1)
727 			kprintf("PMP->IROOT %p REFS WRONG %d\n",
728 				iroot, iroot->refs);
729 #else
730 		KKASSERT(iroot->refs == 1);
731 #endif
732 		/* ref for iroot */
733 		hammer2_inode_drop(iroot);
734 		pmp->iroot = NULL;
735 	}
736 
737 	/*
738 	 * Free remaining pmp resources
739 	 */
740 	if (chains_still_present) {
741 		kprintf("hammer2: cannot free pmp %p, still in use\n", pmp);
742 	} else {
743 		kmalloc_destroy(&pmp->mmsg);
744 		kmalloc_destroy(&pmp->minode);
745 		kfree(pmp, M_HAMMER2);
746 	}
747 }
748 
749 /*
750  * Remove all references to hmp from the pfs list.  Any PFS which becomes
751  * empty is terminated and freed.
752  *
753  * XXX inefficient.
754  */
755 static void
756 hammer2_pfsfree_scan(hammer2_dev_t *hmp, int which)
757 {
758 	hammer2_pfs_t *pmp;
759 	hammer2_inode_t *iroot;
760 	hammer2_chain_t *rchain;
761 	int i;
762 	int j;
763 	struct hammer2_pfslist *wlist;
764 
765 	if (which == 0)
766 		wlist = &hammer2_pfslist;
767 	else
768 		wlist = &hammer2_spmplist;
769 again:
770 	TAILQ_FOREACH(pmp, wlist, mntentry) {
771 		if ((iroot = pmp->iroot) == NULL)
772 			continue;
773 
774 		/*
775 		 * Determine if this PFS is affected.  If it is we must
776 		 * freeze all management threads and lock its iroot.
777 		 *
778 		 * Freezing a management thread forces it idle, operations
779 		 * in-progress will be aborted and it will have to start
780 		 * over again when unfrozen, or exit if told to exit.
781 		 */
782 		for (i = 0; i < HAMMER2_MAXCLUSTER; ++i) {
783 			if (pmp->pfs_hmps[i] == hmp)
784 				break;
785 		}
786 		if (i == HAMMER2_MAXCLUSTER)
787 			continue;
788 
789 		hammer2_vfs_sync_pmp(pmp, MNT_WAIT);
790 
791 		/*
792 		 * Make sure all synchronization threads are locked
793 		 * down.
794 		 */
795 		for (i = 0; i < HAMMER2_MAXCLUSTER; ++i) {
796 			if (pmp->pfs_hmps[i] == NULL)
797 				continue;
798 			hammer2_thr_freeze_async(&pmp->sync_thrs[i]);
799 			for (j = 0; j < HAMMER2_XOPGROUPS; ++j) {
800 				hammer2_thr_freeze_async(
801 					&pmp->xop_groups[j].thrs[i]);
802 			}
803 		}
804 		for (i = 0; i < HAMMER2_MAXCLUSTER; ++i) {
805 			if (pmp->pfs_hmps[i] == NULL)
806 				continue;
807 			hammer2_thr_freeze(&pmp->sync_thrs[i]);
808 			for (j = 0; j < HAMMER2_XOPGROUPS; ++j) {
809 				hammer2_thr_freeze(
810 					&pmp->xop_groups[j].thrs[i]);
811 			}
812 		}
813 
814 		/*
815 		 * Lock the inode and clean out matching chains.
816 		 * Note that we cannot use hammer2_inode_lock_*()
817 		 * here because that would attempt to validate the
818 		 * cluster that we are in the middle of ripping
819 		 * apart.
820 		 *
821 		 * WARNING! We are working directly on the inodes
822 		 *	    embedded cluster.
823 		 */
824 		hammer2_mtx_ex(&iroot->lock);
825 
826 		/*
827 		 * Remove the chain from matching elements of the PFS.
828 		 */
829 		for (i = 0; i < HAMMER2_MAXCLUSTER; ++i) {
830 			if (pmp->pfs_hmps[i] != hmp)
831 				continue;
832 			hammer2_thr_delete(&pmp->sync_thrs[i]);
833 			for (j = 0; j < HAMMER2_XOPGROUPS; ++j) {
834 				hammer2_thr_delete(
835 					&pmp->xop_groups[j].thrs[i]);
836 			}
837 			rchain = iroot->cluster.array[i].chain;
838 			iroot->cluster.array[i].chain = NULL;
839 			pmp->pfs_types[i] = 0;
840 			if (pmp->pfs_names[i]) {
841 				kfree(pmp->pfs_names[i], M_HAMMER2);
842 				pmp->pfs_names[i] = NULL;
843 			}
844 			if (rchain) {
845 				hammer2_chain_drop(rchain);
846 				/* focus hint */
847 				if (iroot->cluster.focus == rchain)
848 					iroot->cluster.focus = NULL;
849 			}
850 			pmp->pfs_hmps[i] = NULL;
851 		}
852 		hammer2_mtx_unlock(&iroot->lock);
853 
854 		/*
855 		 * Cleanup trailing chains.  Gaps may remain.
856 		 */
857 		for (i = HAMMER2_MAXCLUSTER - 1; i >= 0; --i) {
858 			if (pmp->pfs_hmps[i])
859 				break;
860 		}
861 		iroot->cluster.nchains = i + 1;
862 
863 		/*
864 		 * If the PMP has no elements remaining we can destroy it.
865 		 * (this will transition management threads from frozen->exit).
866 		 */
867 		if (iroot->cluster.nchains == 0) {
868 			/*
869 			 * If this was the hmp's spmp, we need to clean
870 			 * a little more stuff out.
871 			 */
872 			if (hmp->spmp == pmp) {
873 				hmp->spmp = NULL;
874 				hmp->vchain.pmp = NULL;
875 				hmp->fchain.pmp = NULL;
876 			}
877 
878 			/*
879 			 * Free the pmp and restart the loop
880 			 */
881 			KKASSERT(TAILQ_EMPTY(&pmp->syncq));
882 			KKASSERT(TAILQ_EMPTY(&pmp->depq));
883 			hammer2_pfsfree(pmp);
884 			goto again;
885 		}
886 
887 		/*
888 		 * If elements still remain we need to set the REMASTER
889 		 * flag and unfreeze it.
890 		 */
891 		for (i = 0; i < HAMMER2_MAXCLUSTER; ++i) {
892 			if (pmp->pfs_hmps[i] == NULL)
893 				continue;
894 			hammer2_thr_remaster(&pmp->sync_thrs[i]);
895 			hammer2_thr_unfreeze(&pmp->sync_thrs[i]);
896 			for (j = 0; j < HAMMER2_XOPGROUPS; ++j) {
897 				hammer2_thr_remaster(
898 					&pmp->xop_groups[j].thrs[i]);
899 				hammer2_thr_unfreeze(
900 					&pmp->xop_groups[j].thrs[i]);
901 			}
902 		}
903 	}
904 }
905 
906 /*
907  * Mount or remount HAMMER2 fileystem from physical media
908  *
909  *	mountroot
910  *		mp		mount point structure
911  *		path		NULL
912  *		data		<unused>
913  *		cred		<unused>
914  *
915  *	mount
916  *		mp		mount point structure
917  *		path		path to mount point
918  *		data		pointer to argument structure in user space
919  *			volume	volume path (device@LABEL form)
920  *			hflags	user mount flags
921  *		cred		user credentials
922  *
923  * RETURNS:	0	Success
924  *		!0	error number
925  */
926 static
927 int
928 hammer2_vfs_mount(struct mount *mp, char *path, caddr_t data,
929 		  struct ucred *cred)
930 {
931 	struct hammer2_mount_info info;
932 	hammer2_pfs_t *pmp;
933 	hammer2_pfs_t *spmp;
934 	hammer2_dev_t *hmp;
935 	hammer2_dev_t *force_local;
936 	hammer2_key_t key_next;
937 	hammer2_key_t key_dummy;
938 	hammer2_key_t lhc;
939 	struct vnode *devvp;
940 	struct nlookupdata nd;
941 	hammer2_chain_t *parent;
942 	hammer2_chain_t *chain;
943 	const hammer2_inode_data_t *ripdata;
944 	hammer2_blockref_t bref;
945 	struct file *fp;
946 	char devstr[MNAMELEN];
947 	size_t size;
948 	size_t done;
949 	char *dev;
950 	char *label;
951 	int ronly = 1;
952 	int error;
953 	int i;
954 
955 	hmp = NULL;
956 	pmp = NULL;
957 	dev = NULL;
958 	label = NULL;
959 	devvp = NULL;
960 
961 	if (path == NULL) {
962 		/*
963 		 * Root mount
964 		 */
965 		bzero(&info, sizeof(info));
966 		info.cluster_fd = -1;
967 		ksnprintf(devstr, sizeof(devstr), "%s",
968 			  mp->mnt_stat.f_mntfromname);
969 		kprintf("hammer2_mount: root '%s'\n", devstr);
970 		done = strlen(devstr) + 1;
971 	} else {
972 		/*
973 		 * Non-root mount or updating a mount
974 		 */
975 		error = copyin(data, &info, sizeof(info));
976 		if (error)
977 			return (error);
978 
979 		error = copyinstr(info.volume, devstr, MNAMELEN - 1, &done);
980 		if (error)
981 			return (error);
982 		kprintf("hammer2_mount: '%s'\n", devstr);
983 	}
984 
985 	/*
986 	 * Extract device and label, automatically mount @BOOT, @ROOT, or @DATA
987 	 * if no label specified, based on the partition id.  Error out if no
988 	 * label or device (with partition id) is specified.  This is strictly
989 	 * a convenience to match the default label created by newfs_hammer2,
990 	 * our preference is that a label always be specified.
991 	 *
992 	 * NOTE: We allow 'mount @LABEL <blah>'... that is, a mount command
993 	 *	 that does not specify a device, as long as some H2 label
994 	 *	 has already been mounted from that device.  This makes
995 	 *	 mounting snapshots a lot easier.
996 	 */
997 	dev = devstr;
998 	label = strchr(devstr, '@');
999 	if (label && ((label + 1) - dev) > done) {
1000 		kprintf("hammer2: mount: bad label %s/%zd\n",
1001 			devstr, done);
1002 		return (EINVAL);
1003 	}
1004 	if (label == NULL || label[1] == 0) {
1005 		char slice;
1006 
1007 		if (label == NULL)
1008 			label = devstr + strlen(devstr);
1009 		else
1010 			*label = '\0';		/* clean up trailing @ */
1011 
1012 		slice = label[-1];
1013 		switch(slice) {
1014 		case 'a':
1015 			label = "BOOT";
1016 			break;
1017 		case 'd':
1018 			label = "ROOT";
1019 			break;
1020 		default:
1021 			label = "DATA";
1022 			break;
1023 		}
1024 	} else {
1025 		*label = '\0';
1026 		label++;
1027 	}
1028 
1029 	kprintf("hammer2_mount: dev=\"%s\" label=\"%s\" rdonly=%d\n",
1030 		dev, label, (mp->mnt_flag & MNT_RDONLY));
1031 
1032 	if (mp->mnt_flag & MNT_UPDATE) {
1033 		/*
1034 		 * Update mount.  Note that pmp->iroot->cluster is
1035 		 * an inode-embedded cluster and thus cannot be
1036 		 * directly locked.
1037 		 *
1038 		 * XXX HAMMER2 needs to implement NFS export via
1039 		 *     mountctl.
1040 		 */
1041 		hammer2_cluster_t *cluster;
1042 
1043 		pmp = MPTOPMP(mp);
1044 		pmp->hflags = info.hflags;
1045 		cluster = &pmp->iroot->cluster;
1046 		for (i = 0; i < cluster->nchains; ++i) {
1047 			if (cluster->array[i].chain == NULL)
1048 				continue;
1049 			hmp = cluster->array[i].chain->hmp;
1050 			devvp = hmp->devvp;
1051 			error = hammer2_remount(hmp, mp, path,
1052 						devvp, cred);
1053 			if (error)
1054 				break;
1055 		}
1056 
1057 		return error;
1058 	}
1059 
1060 	/*
1061 	 * HMP device mount
1062 	 *
1063 	 * If a path is specified and dev is not an empty string, lookup the
1064 	 * name and verify that it referes to a block device.
1065 	 *
1066 	 * If a path is specified and dev is an empty string we fall through
1067 	 * and locate the label in the hmp search.
1068 	 */
1069 	if (path && *dev != 0) {
1070 		error = nlookup_init(&nd, dev, UIO_SYSSPACE, NLC_FOLLOW);
1071 		if (error == 0)
1072 			error = nlookup(&nd);
1073 		if (error == 0)
1074 			error = cache_vref(&nd.nl_nch, nd.nl_cred, &devvp);
1075 		nlookup_done(&nd);
1076 	} else if (path == NULL) {
1077 		/* root mount */
1078 		cdev_t cdev = kgetdiskbyname(dev);
1079 		error = bdevvp(cdev, &devvp);
1080 		if (error)
1081 			kprintf("hammer2: cannot find '%s'\n", dev);
1082 	} else {
1083 		/*
1084 		 * We will locate the hmp using the label in the hmp loop.
1085 		 */
1086 		error = 0;
1087 	}
1088 
1089 	/*
1090 	 * Make sure its a block device.  Do not check to see if it is
1091 	 * already mounted until we determine that its a fresh H2 device.
1092 	 */
1093 	if (error == 0 && devvp) {
1094 		vn_isdisk(devvp, &error);
1095 	}
1096 
1097 	/*
1098 	 * Determine if the device has already been mounted.  After this
1099 	 * check hmp will be non-NULL if we are doing the second or more
1100 	 * hammer2 mounts from the same device.
1101 	 */
1102 	lockmgr(&hammer2_mntlk, LK_EXCLUSIVE);
1103 	if (devvp) {
1104 		/*
1105 		 * Match the device.  Due to the way devfs works,
1106 		 * we may not be able to directly match the vnode pointer,
1107 		 * so also check to see if the underlying device matches.
1108 		 */
1109 		TAILQ_FOREACH(hmp, &hammer2_mntlist, mntentry) {
1110 			if (hmp->devvp == devvp)
1111 				break;
1112 			if (devvp->v_rdev &&
1113 			    hmp->devvp->v_rdev == devvp->v_rdev) {
1114 				break;
1115 			}
1116 		}
1117 
1118 		/*
1119 		 * If no match this may be a fresh H2 mount, make sure
1120 		 * the device is not mounted on anything else.
1121 		 */
1122 		if (hmp == NULL)
1123 			error = vfs_mountedon(devvp);
1124 	} else if (error == 0) {
1125 		/*
1126 		 * Match the label to a pmp already probed.
1127 		 */
1128 		TAILQ_FOREACH(pmp, &hammer2_pfslist, mntentry) {
1129 			for (i = 0; i < HAMMER2_MAXCLUSTER; ++i) {
1130 				if (pmp->pfs_names[i] &&
1131 				    strcmp(pmp->pfs_names[i], label) == 0) {
1132 					hmp = pmp->pfs_hmps[i];
1133 					break;
1134 				}
1135 			}
1136 			if (hmp)
1137 				break;
1138 		}
1139 		if (hmp == NULL)
1140 			error = ENOENT;
1141 	}
1142 
1143 	/*
1144 	 * Open the device if this isn't a secondary mount and construct
1145 	 * the H2 device mount (hmp).
1146 	 */
1147 	if (hmp == NULL) {
1148 		hammer2_chain_t *schain;
1149 		hammer2_xid_t xid;
1150 		hammer2_xop_head_t xop;
1151 
1152 		if (error == 0 && vcount(devvp) > 0) {
1153 			kprintf("Primary device already has references\n");
1154 			error = EBUSY;
1155 		}
1156 
1157 		/*
1158 		 * Now open the device
1159 		 */
1160 		if (error == 0) {
1161 			ronly = ((mp->mnt_flag & MNT_RDONLY) != 0);
1162 			vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
1163 			error = vinvalbuf(devvp, V_SAVE, 0, 0);
1164 			if (error == 0) {
1165 				error = VOP_OPEN(devvp,
1166 					     (ronly ? FREAD : FREAD | FWRITE),
1167 					     FSCRED, NULL);
1168 			}
1169 			vn_unlock(devvp);
1170 		}
1171 		if (error && devvp) {
1172 			vrele(devvp);
1173 			devvp = NULL;
1174 		}
1175 		if (error) {
1176 			lockmgr(&hammer2_mntlk, LK_RELEASE);
1177 			return error;
1178 		}
1179 		hmp = kmalloc(sizeof(*hmp), M_HAMMER2, M_WAITOK | M_ZERO);
1180 		ksnprintf(hmp->devrepname, sizeof(hmp->devrepname), "%s", dev);
1181 		hmp->ronly = ronly;
1182 		hmp->devvp = devvp;
1183 		hmp->hflags = info.hflags & HMNT2_DEVFLAGS;
1184 		kmalloc_create(&hmp->mchain, "HAMMER2-chains");
1185 		TAILQ_INSERT_TAIL(&hammer2_mntlist, hmp, mntentry);
1186 		RB_INIT(&hmp->iotree);
1187 		spin_init(&hmp->io_spin, "h2mount_io");
1188 		spin_init(&hmp->list_spin, "h2mount_list");
1189 
1190 		lockinit(&hmp->vollk, "h2vol", 0, 0);
1191 		lockinit(&hmp->bulklk, "h2bulk", 0, 0);
1192 		lockinit(&hmp->bflock, "h2bflk", 0, 0);
1193 
1194 		/*
1195 		 * vchain setup. vchain.data is embedded.
1196 		 * vchain.refs is initialized and will never drop to 0.
1197 		 *
1198 		 * NOTE! voldata is not yet loaded.
1199 		 */
1200 		hmp->vchain.hmp = hmp;
1201 		hmp->vchain.refs = 1;
1202 		hmp->vchain.data = (void *)&hmp->voldata;
1203 		hmp->vchain.bref.type = HAMMER2_BREF_TYPE_VOLUME;
1204 		hmp->vchain.bref.data_off = 0 | HAMMER2_PBUFRADIX;
1205 		hmp->vchain.bref.mirror_tid = hmp->voldata.mirror_tid;
1206 
1207 		hammer2_chain_core_init(&hmp->vchain);
1208 		/* hmp->vchain.u.xxx is left NULL */
1209 
1210 		/*
1211 		 * fchain setup.  fchain.data is embedded.
1212 		 * fchain.refs is initialized and will never drop to 0.
1213 		 *
1214 		 * The data is not used but needs to be initialized to
1215 		 * pass assertion muster.  We use this chain primarily
1216 		 * as a placeholder for the freemap's top-level RBTREE
1217 		 * so it does not interfere with the volume's topology
1218 		 * RBTREE.
1219 		 */
1220 		hmp->fchain.hmp = hmp;
1221 		hmp->fchain.refs = 1;
1222 		hmp->fchain.data = (void *)&hmp->voldata.freemap_blockset;
1223 		hmp->fchain.bref.type = HAMMER2_BREF_TYPE_FREEMAP;
1224 		hmp->fchain.bref.data_off = 0 | HAMMER2_PBUFRADIX;
1225 		hmp->fchain.bref.mirror_tid = hmp->voldata.freemap_tid;
1226 		hmp->fchain.bref.methods =
1227 			HAMMER2_ENC_CHECK(HAMMER2_CHECK_FREEMAP) |
1228 			HAMMER2_ENC_COMP(HAMMER2_COMP_NONE);
1229 
1230 		hammer2_chain_core_init(&hmp->fchain);
1231 		/* hmp->fchain.u.xxx is left NULL */
1232 
1233 		/*
1234 		 * Install the volume header and initialize fields from
1235 		 * voldata.
1236 		 */
1237 		error = hammer2_install_volume_header(hmp);
1238 		if (error) {
1239 			hammer2_unmount_helper(mp, NULL, hmp);
1240 			lockmgr(&hammer2_mntlk, LK_RELEASE);
1241 			hammer2_vfs_unmount(mp, MNT_FORCE);
1242 			return error;
1243 		}
1244 
1245 		/*
1246 		 * Really important to get these right or flush will get
1247 		 * confused.
1248 		 */
1249 		hmp->spmp = hammer2_pfsalloc(NULL, NULL, 0, NULL);
1250 		spmp = hmp->spmp;
1251 
1252 		/*
1253 		 * Dummy-up vchain and fchain's modify_tid.  mirror_tid
1254 		 * is inherited from the volume header.
1255 		 */
1256 		xid = 0;
1257 		hmp->vchain.bref.mirror_tid = hmp->voldata.mirror_tid;
1258 		hmp->vchain.bref.modify_tid = hmp->vchain.bref.mirror_tid;
1259 		hmp->vchain.pmp = spmp;
1260 		hmp->fchain.bref.mirror_tid = hmp->voldata.freemap_tid;
1261 		hmp->fchain.bref.modify_tid = hmp->fchain.bref.mirror_tid;
1262 		hmp->fchain.pmp = spmp;
1263 
1264 		/*
1265 		 * First locate the super-root inode, which is key 0
1266 		 * relative to the volume header's blockset.
1267 		 *
1268 		 * Then locate the root inode by scanning the directory keyspace
1269 		 * represented by the label.
1270 		 */
1271 		parent = hammer2_chain_lookup_init(&hmp->vchain, 0);
1272 		schain = hammer2_chain_lookup(&parent, &key_dummy,
1273 				      HAMMER2_SROOT_KEY, HAMMER2_SROOT_KEY,
1274 				      &error, 0);
1275 		hammer2_chain_lookup_done(parent);
1276 		if (schain == NULL) {
1277 			kprintf("hammer2_mount: invalid super-root\n");
1278 			hammer2_unmount_helper(mp, NULL, hmp);
1279 			lockmgr(&hammer2_mntlk, LK_RELEASE);
1280 			hammer2_vfs_unmount(mp, MNT_FORCE);
1281 			return EINVAL;
1282 		}
1283 		if (schain->error) {
1284 			kprintf("hammer2_mount: error %s reading super-root\n",
1285 				hammer2_error_str(schain->error));
1286 			hammer2_chain_unlock(schain);
1287 			hammer2_chain_drop(schain);
1288 			schain = NULL;
1289 			hammer2_unmount_helper(mp, NULL, hmp);
1290 			lockmgr(&hammer2_mntlk, LK_RELEASE);
1291 			hammer2_vfs_unmount(mp, MNT_FORCE);
1292 			return EINVAL;
1293 		}
1294 
1295 		/*
1296 		 * The super-root always uses an inode_tid of 1 when
1297 		 * creating PFSs.
1298 		 */
1299 		spmp->inode_tid = 1;
1300 		spmp->modify_tid = schain->bref.modify_tid + 1;
1301 
1302 		/*
1303 		 * Sanity-check schain's pmp and finish initialization.
1304 		 * Any chain belonging to the super-root topology should
1305 		 * have a NULL pmp (not even set to spmp).
1306 		 */
1307 		ripdata = &hammer2_chain_rdata(schain)->ipdata;
1308 		KKASSERT(schain->pmp == NULL);
1309 		spmp->pfs_clid = ripdata->meta.pfs_clid;
1310 
1311 		/*
1312 		 * Replace the dummy spmp->iroot with a real one.  It's
1313 		 * easier to just do a wholesale replacement than to try
1314 		 * to update the chain and fixup the iroot fields.
1315 		 *
1316 		 * The returned inode is locked with the supplied cluster.
1317 		 */
1318 		hammer2_dummy_xop_from_chain(&xop, schain);
1319 		hammer2_inode_drop(spmp->iroot);
1320 		spmp->iroot = NULL;
1321 		spmp->iroot = hammer2_inode_get(spmp, &xop, -1, -1);
1322 		spmp->spmp_hmp = hmp;
1323 		spmp->pfs_types[0] = ripdata->meta.pfs_type;
1324 		spmp->pfs_hmps[0] = hmp;
1325 		hammer2_inode_ref(spmp->iroot);
1326 		hammer2_inode_unlock(spmp->iroot);
1327 		hammer2_cluster_unlock(&xop.cluster);
1328 		hammer2_chain_drop(schain);
1329 		/* do not call hammer2_cluster_drop() on an embedded cluster */
1330 		schain = NULL;	/* now invalid */
1331 		/* leave spmp->iroot with one ref */
1332 
1333 		if ((mp->mnt_flag & MNT_RDONLY) == 0) {
1334 			error = hammer2_recovery(hmp);
1335 			if (error == 0)
1336 				error |= hammer2_fixup_pfses(hmp);
1337 			/* XXX do something with error */
1338 		}
1339 		hammer2_update_pmps(hmp);
1340 		hammer2_iocom_init(hmp);
1341 		hammer2_bulkfree_init(hmp);
1342 
1343 		/*
1344 		 * Ref the cluster management messaging descriptor.  The mount
1345 		 * program deals with the other end of the communications pipe.
1346 		 *
1347 		 * Root mounts typically do not supply one.
1348 		 */
1349 		if (info.cluster_fd >= 0) {
1350 			fp = holdfp(curthread, info.cluster_fd, -1);
1351 			if (fp) {
1352 				hammer2_cluster_reconnect(hmp, fp);
1353 			} else {
1354 				kprintf("hammer2_mount: bad cluster_fd!\n");
1355 			}
1356 		}
1357 	} else {
1358 		spmp = hmp->spmp;
1359 		if (info.hflags & HMNT2_DEVFLAGS) {
1360 			kprintf("hammer2: Warning: mount flags pertaining "
1361 				"to the whole device may only be specified "
1362 				"on the first mount of the device: %08x\n",
1363 				info.hflags & HMNT2_DEVFLAGS);
1364 		}
1365 	}
1366 
1367 	/*
1368 	 * Force local mount (disassociate all PFSs from their clusters).
1369 	 * Used primarily for debugging.
1370 	 */
1371 	force_local = (hmp->hflags & HMNT2_LOCAL) ? hmp : NULL;
1372 
1373 	/*
1374 	 * Lookup the mount point under the media-localized super-root.
1375 	 * Scanning hammer2_pfslist doesn't help us because it represents
1376 	 * PFS cluster ids which can aggregate several named PFSs together.
1377 	 *
1378 	 * cluster->pmp will incorrectly point to spmp and must be fixed
1379 	 * up later on.
1380 	 */
1381 	hammer2_inode_lock(spmp->iroot, 0);
1382 	parent = hammer2_inode_chain(spmp->iroot, 0, HAMMER2_RESOLVE_ALWAYS);
1383 	lhc = hammer2_dirhash(label, strlen(label));
1384 	chain = hammer2_chain_lookup(&parent, &key_next,
1385 				     lhc, lhc + HAMMER2_DIRHASH_LOMASK,
1386 				     &error, 0);
1387 	while (chain) {
1388 		if (chain->bref.type == HAMMER2_BREF_TYPE_INODE &&
1389 		    strcmp(label, chain->data->ipdata.filename) == 0) {
1390 			break;
1391 		}
1392 		chain = hammer2_chain_next(&parent, chain, &key_next,
1393 					    key_next,
1394 					    lhc + HAMMER2_DIRHASH_LOMASK,
1395 					    &error, 0);
1396 	}
1397 	if (parent) {
1398 		hammer2_chain_unlock(parent);
1399 		hammer2_chain_drop(parent);
1400 	}
1401 	hammer2_inode_unlock(spmp->iroot);
1402 
1403 	/*
1404 	 * PFS could not be found?
1405 	 */
1406 	if (chain == NULL) {
1407 		if (error)
1408 			kprintf("hammer2_mount: PFS label I/O error\n");
1409 		else
1410 			kprintf("hammer2_mount: PFS label not found\n");
1411 		hammer2_unmount_helper(mp, NULL, hmp);
1412 		lockmgr(&hammer2_mntlk, LK_RELEASE);
1413 		hammer2_vfs_unmount(mp, MNT_FORCE);
1414 
1415 		return EINVAL;
1416 	}
1417 
1418 	/*
1419 	 * Acquire the pmp structure (it should have already been allocated
1420 	 * via hammer2_update_pmps() so do not pass cluster in to add to
1421 	 * available chains).
1422 	 *
1423 	 * Check if the cluster has already been mounted.  A cluster can
1424 	 * only be mounted once, use null mounts to mount additional copies.
1425 	 */
1426 	if (chain->error) {
1427 		kprintf("hammer2_mount: PFS label I/O error\n");
1428 	} else {
1429 		ripdata = &chain->data->ipdata;
1430 		bref = chain->bref;
1431 		pmp = hammer2_pfsalloc(NULL, ripdata,
1432 				       bref.modify_tid, force_local);
1433 	}
1434 	hammer2_chain_unlock(chain);
1435 	hammer2_chain_drop(chain);
1436 
1437 	/*
1438 	 * Finish the mount
1439 	 */
1440         kprintf("hammer2_mount hmp=%p pmp=%p\n", hmp, pmp);
1441 
1442 	if (pmp->mp) {
1443 		kprintf("hammer2_mount: PFS already mounted!\n");
1444 		hammer2_unmount_helper(mp, NULL, hmp);
1445 		lockmgr(&hammer2_mntlk, LK_RELEASE);
1446 		hammer2_vfs_unmount(mp, MNT_FORCE);
1447 
1448 		return EBUSY;
1449 	}
1450 
1451 	pmp->hflags = info.hflags;
1452         mp->mnt_flag |= MNT_LOCAL;
1453         mp->mnt_kern_flag |= MNTK_ALL_MPSAFE;   /* all entry pts are SMP */
1454         mp->mnt_kern_flag |= MNTK_THR_SYNC;     /* new vsyncscan semantics */
1455 
1456         /*
1457          * required mount structure initializations
1458          */
1459         mp->mnt_stat.f_iosize = HAMMER2_PBUFSIZE;
1460         mp->mnt_stat.f_bsize = HAMMER2_PBUFSIZE;
1461 
1462         mp->mnt_vstat.f_frsize = HAMMER2_PBUFSIZE;
1463         mp->mnt_vstat.f_bsize = HAMMER2_PBUFSIZE;
1464 
1465         /*
1466          * Optional fields
1467          */
1468         mp->mnt_iosize_max = MAXPHYS;
1469 
1470 	/*
1471 	 * Connect up mount pointers.
1472 	 */
1473 	hammer2_mount_helper(mp, pmp);
1474 
1475         lockmgr(&hammer2_mntlk, LK_RELEASE);
1476 
1477 	/*
1478 	 * Finish setup
1479 	 */
1480 	vfs_getnewfsid(mp);
1481 	vfs_add_vnodeops(mp, &hammer2_vnode_vops, &mp->mnt_vn_norm_ops);
1482 	vfs_add_vnodeops(mp, &hammer2_spec_vops, &mp->mnt_vn_spec_ops);
1483 	vfs_add_vnodeops(mp, &hammer2_fifo_vops, &mp->mnt_vn_fifo_ops);
1484 
1485 	if (path) {
1486 		copyinstr(info.volume, mp->mnt_stat.f_mntfromname,
1487 			  MNAMELEN - 1, &size);
1488 		bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
1489 	} /* else root mount, already in there */
1490 
1491 	bzero(mp->mnt_stat.f_mntonname, sizeof(mp->mnt_stat.f_mntonname));
1492 	if (path) {
1493 		copyinstr(path, mp->mnt_stat.f_mntonname,
1494 			  sizeof(mp->mnt_stat.f_mntonname) - 1,
1495 			  &size);
1496 	} else {
1497 		/* root mount */
1498 		mp->mnt_stat.f_mntonname[0] = '/';
1499 	}
1500 
1501 	/*
1502 	 * Initial statfs to prime mnt_stat.
1503 	 */
1504 	hammer2_vfs_statfs(mp, &mp->mnt_stat, cred);
1505 
1506 	return 0;
1507 }
1508 
1509 /*
1510  * Scan PFSs under the super-root and create hammer2_pfs structures.
1511  */
1512 static
1513 void
1514 hammer2_update_pmps(hammer2_dev_t *hmp)
1515 {
1516 	const hammer2_inode_data_t *ripdata;
1517 	hammer2_chain_t *parent;
1518 	hammer2_chain_t *chain;
1519 	hammer2_blockref_t bref;
1520 	hammer2_dev_t *force_local;
1521 	hammer2_pfs_t *spmp;
1522 	hammer2_pfs_t *pmp;
1523 	hammer2_key_t key_next;
1524 	int error;
1525 
1526 	/*
1527 	 * Force local mount (disassociate all PFSs from their clusters).
1528 	 * Used primarily for debugging.
1529 	 */
1530 	force_local = (hmp->hflags & HMNT2_LOCAL) ? hmp : NULL;
1531 
1532 	/*
1533 	 * Lookup mount point under the media-localized super-root.
1534 	 *
1535 	 * cluster->pmp will incorrectly point to spmp and must be fixed
1536 	 * up later on.
1537 	 */
1538 	spmp = hmp->spmp;
1539 	hammer2_inode_lock(spmp->iroot, 0);
1540 	parent = hammer2_inode_chain(spmp->iroot, 0, HAMMER2_RESOLVE_ALWAYS);
1541 	chain = hammer2_chain_lookup(&parent, &key_next,
1542 					 HAMMER2_KEY_MIN, HAMMER2_KEY_MAX,
1543 					 &error, 0);
1544 	while (chain) {
1545 		if (chain->bref.type != HAMMER2_BREF_TYPE_INODE)
1546 			continue;
1547 		if (chain->error) {
1548 			kprintf("I/O error scanning PFS labels\n");
1549 		} else {
1550 			ripdata = &chain->data->ipdata;
1551 			bref = chain->bref;
1552 
1553 			pmp = hammer2_pfsalloc(chain, ripdata,
1554 					       bref.modify_tid, force_local);
1555 		}
1556 		chain = hammer2_chain_next(&parent, chain, &key_next,
1557 					   key_next, HAMMER2_KEY_MAX,
1558 					   &error, 0);
1559 	}
1560 	if (parent) {
1561 		hammer2_chain_unlock(parent);
1562 		hammer2_chain_drop(parent);
1563 	}
1564 	hammer2_inode_unlock(spmp->iroot);
1565 }
1566 
1567 static
1568 int
1569 hammer2_remount(hammer2_dev_t *hmp, struct mount *mp, char *path __unused,
1570 		struct vnode *devvp, struct ucred *cred)
1571 {
1572 	int error;
1573 
1574 	if (hmp->ronly && (mp->mnt_kern_flag & MNTK_WANTRDWR)) {
1575 		vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
1576 		VOP_OPEN(devvp, FREAD | FWRITE, FSCRED, NULL);
1577 		vn_unlock(devvp);
1578 		error = hammer2_recovery(hmp);
1579 		if (error == 0)
1580 			error |= hammer2_fixup_pfses(hmp);
1581 		vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
1582 		if (error == 0) {
1583 			VOP_CLOSE(devvp, FREAD, NULL);
1584 			hmp->ronly = 0;
1585 		} else {
1586 			VOP_CLOSE(devvp, FREAD | FWRITE, NULL);
1587 		}
1588 		vn_unlock(devvp);
1589 	} else {
1590 		error = 0;
1591 	}
1592 	return error;
1593 }
1594 
1595 static
1596 int
1597 hammer2_vfs_unmount(struct mount *mp, int mntflags)
1598 {
1599 	hammer2_pfs_t *pmp;
1600 	int flags;
1601 	int error = 0;
1602 
1603 	pmp = MPTOPMP(mp);
1604 
1605 	if (pmp == NULL)
1606 		return(0);
1607 
1608 	lockmgr(&hammer2_mntlk, LK_EXCLUSIVE);
1609 
1610 	/*
1611 	 * If mount initialization proceeded far enough we must flush
1612 	 * its vnodes and sync the underlying mount points.  Three syncs
1613 	 * are required to fully flush the filesystem (freemap updates lag
1614 	 * by one flush, and one extra for safety).
1615 	 */
1616 	if (mntflags & MNT_FORCE)
1617 		flags = FORCECLOSE;
1618 	else
1619 		flags = 0;
1620 	if (pmp->iroot) {
1621 		error = vflush(mp, 0, flags);
1622 		if (error)
1623 			goto failed;
1624 		hammer2_vfs_sync(mp, MNT_WAIT);
1625 		hammer2_vfs_sync(mp, MNT_WAIT);
1626 		hammer2_vfs_sync(mp, MNT_WAIT);
1627 	}
1628 
1629 	/*
1630 	 * Cleanup the frontend support XOPS threads
1631 	 */
1632 	hammer2_xop_helper_cleanup(pmp);
1633 
1634 	if (pmp->mp)
1635 		hammer2_unmount_helper(mp, pmp, NULL);
1636 
1637 	error = 0;
1638 failed:
1639 	lockmgr(&hammer2_mntlk, LK_RELEASE);
1640 
1641 	return (error);
1642 }
1643 
1644 /*
1645  * Mount helper, hook the system mount into our PFS.
1646  * The mount lock is held.
1647  *
1648  * We must bump the mount_count on related devices for any
1649  * mounted PFSs.
1650  */
1651 static
1652 void
1653 hammer2_mount_helper(struct mount *mp, hammer2_pfs_t *pmp)
1654 {
1655 	hammer2_cluster_t *cluster;
1656 	hammer2_chain_t *rchain;
1657 	int i;
1658 
1659         mp->mnt_data = (qaddr_t)pmp;
1660 	pmp->mp = mp;
1661 
1662 	/*
1663 	 * After pmp->mp is set we have to adjust hmp->mount_count.
1664 	 */
1665 	cluster = &pmp->iroot->cluster;
1666 	for (i = 0; i < cluster->nchains; ++i) {
1667 		rchain = cluster->array[i].chain;
1668 		if (rchain == NULL)
1669 			continue;
1670 		++rchain->hmp->mount_count;
1671 	}
1672 
1673 	/*
1674 	 * Create missing Xop threads
1675 	 */
1676 	hammer2_xop_helper_create(pmp);
1677 }
1678 
1679 /*
1680  * Mount helper, unhook the system mount from our PFS.
1681  * The mount lock is held.
1682  *
1683  * If hmp is supplied a mount responsible for being the first to open
1684  * the block device failed and the block device and all PFSs using the
1685  * block device must be cleaned up.
1686  *
1687  * If pmp is supplied multiple devices might be backing the PFS and each
1688  * must be disconnected.  This might not be the last PFS using some of the
1689  * underlying devices.  Also, we have to adjust our hmp->mount_count
1690  * accounting for the devices backing the pmp which is now undergoing an
1691  * unmount.
1692  */
1693 static
1694 void
1695 hammer2_unmount_helper(struct mount *mp, hammer2_pfs_t *pmp, hammer2_dev_t *hmp)
1696 {
1697 	hammer2_cluster_t *cluster;
1698 	hammer2_chain_t *rchain;
1699 	struct vnode *devvp;
1700 	int dumpcnt;
1701 	int ronly;
1702 	int i;
1703 
1704 	/*
1705 	 * If no device supplied this is a high-level unmount and we have to
1706 	 * to disconnect the mount, adjust mount_count, and locate devices
1707 	 * that might now have no mounts.
1708 	 */
1709 	if (pmp) {
1710 		KKASSERT(hmp == NULL);
1711 		KKASSERT((void *)(intptr_t)mp->mnt_data == pmp);
1712 		pmp->mp = NULL;
1713 		mp->mnt_data = NULL;
1714 
1715 		/*
1716 		 * After pmp->mp is cleared we have to account for
1717 		 * mount_count.
1718 		 */
1719 		cluster = &pmp->iroot->cluster;
1720 		for (i = 0; i < cluster->nchains; ++i) {
1721 			rchain = cluster->array[i].chain;
1722 			if (rchain == NULL)
1723 				continue;
1724 			--rchain->hmp->mount_count;
1725 			/* scrapping hmp now may invalidate the pmp */
1726 		}
1727 again:
1728 		TAILQ_FOREACH(hmp, &hammer2_mntlist, mntentry) {
1729 			if (hmp->mount_count == 0) {
1730 				hammer2_unmount_helper(NULL, NULL, hmp);
1731 				goto again;
1732 			}
1733 		}
1734 		return;
1735 	}
1736 
1737 	/*
1738 	 * Try to terminate the block device.  We can't terminate it if
1739 	 * there are still PFSs referencing it.
1740 	 */
1741 	if (hmp->mount_count)
1742 		return;
1743 
1744 	/*
1745 	 * Decomission the network before we start messing with the
1746 	 * device and PFS.
1747 	 */
1748 	hammer2_iocom_uninit(hmp);
1749 
1750 	hammer2_bulkfree_uninit(hmp);
1751 	hammer2_pfsfree_scan(hmp, 0);
1752 #if 0
1753 	hammer2_dev_exlock(hmp);	/* XXX order */
1754 #endif
1755 
1756 	/*
1757 	 * Cycle the volume data lock as a safety (probably not needed any
1758 	 * more).  To ensure everything is out we need to flush at least
1759 	 * three times.  (1) The running of the sideq can dirty the
1760 	 * filesystem, (2) A normal flush can dirty the freemap, and
1761 	 * (3) ensure that the freemap is fully synchronized.
1762 	 *
1763 	 * The next mount's recovery scan can clean everything up but we want
1764 	 * to leave the filesystem in a 100% clean state on a normal unmount.
1765 	 */
1766 #if 0
1767 	hammer2_voldata_lock(hmp);
1768 	hammer2_voldata_unlock(hmp);
1769 #endif
1770 
1771 	/*
1772 	 * Flush whatever is left.  Unmounted but modified PFS's might still
1773 	 * have some dirty chains on them.
1774 	 */
1775 	hammer2_chain_lock(&hmp->vchain, HAMMER2_RESOLVE_ALWAYS);
1776 	hammer2_chain_lock(&hmp->fchain, HAMMER2_RESOLVE_ALWAYS);
1777 
1778 	if (hmp->fchain.flags & HAMMER2_CHAIN_FLUSH_MASK) {
1779 		hammer2_voldata_modify(hmp);
1780 		hammer2_flush(&hmp->fchain, HAMMER2_FLUSH_TOP |
1781 					    HAMMER2_FLUSH_ALL);
1782 	}
1783 	hammer2_chain_unlock(&hmp->fchain);
1784 
1785 	if (hmp->vchain.flags & HAMMER2_CHAIN_FLUSH_MASK) {
1786 		hammer2_flush(&hmp->vchain, HAMMER2_FLUSH_TOP |
1787 					    HAMMER2_FLUSH_ALL);
1788 	}
1789 	hammer2_chain_unlock(&hmp->vchain);
1790 
1791 	if ((hmp->vchain.flags | hmp->fchain.flags) &
1792 	    HAMMER2_CHAIN_FLUSH_MASK) {
1793 		kprintf("hammer2_unmount: chains left over "
1794 			"after final sync\n");
1795 		kprintf("    vchain %08x\n", hmp->vchain.flags);
1796 		kprintf("    fchain %08x\n", hmp->fchain.flags);
1797 
1798 		if (hammer2_debug & 0x0010)
1799 			Debugger("entered debugger");
1800 	}
1801 
1802 	hammer2_pfsfree_scan(hmp, 1);
1803 
1804 	KKASSERT(hmp->spmp == NULL);
1805 
1806 	/*
1807 	 * Finish up with the device vnode
1808 	 */
1809 	if ((devvp = hmp->devvp) != NULL) {
1810 		ronly = hmp->ronly;
1811 		vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
1812 		kprintf("hammer2_unmount(A): devvp %s rbdirty %p ronly=%d\n",
1813 			hmp->devrepname, RB_ROOT(&devvp->v_rbdirty_tree),
1814 			ronly);
1815 		vinvalbuf(devvp, (ronly ? 0 : V_SAVE), 0, 0);
1816 		kprintf("hammer2_unmount(B): devvp %s rbdirty %p\n",
1817 			hmp->devrepname, RB_ROOT(&devvp->v_rbdirty_tree));
1818 		hmp->devvp = NULL;
1819 		VOP_CLOSE(devvp, (ronly ? FREAD : FREAD|FWRITE), NULL);
1820 		vn_unlock(devvp);
1821 		vrele(devvp);
1822 		devvp = NULL;
1823 	}
1824 
1825 	/*
1826 	 * Clear vchain/fchain flags that might prevent final cleanup
1827 	 * of these chains.
1828 	 */
1829 	if (hmp->vchain.flags & HAMMER2_CHAIN_MODIFIED) {
1830 		atomic_add_long(&hammer2_count_modified_chains, -1);
1831 		atomic_clear_int(&hmp->vchain.flags, HAMMER2_CHAIN_MODIFIED);
1832 		hammer2_pfs_memory_wakeup(hmp->vchain.pmp);
1833 	}
1834 	if (hmp->vchain.flags & HAMMER2_CHAIN_UPDATE) {
1835 		atomic_clear_int(&hmp->vchain.flags, HAMMER2_CHAIN_UPDATE);
1836 	}
1837 
1838 	if (hmp->fchain.flags & HAMMER2_CHAIN_MODIFIED) {
1839 		atomic_add_long(&hammer2_count_modified_chains, -1);
1840 		atomic_clear_int(&hmp->fchain.flags, HAMMER2_CHAIN_MODIFIED);
1841 		hammer2_pfs_memory_wakeup(hmp->fchain.pmp);
1842 	}
1843 	if (hmp->fchain.flags & HAMMER2_CHAIN_UPDATE) {
1844 		atomic_clear_int(&hmp->fchain.flags, HAMMER2_CHAIN_UPDATE);
1845 	}
1846 
1847 	/*
1848 	 * Final drop of embedded freemap root chain to
1849 	 * clean up fchain.core (fchain structure is not
1850 	 * flagged ALLOCATED so it is cleaned out and then
1851 	 * left to rot).
1852 	 */
1853 	hammer2_chain_drop(&hmp->fchain);
1854 
1855 	/*
1856 	 * Final drop of embedded volume root chain to clean
1857 	 * up vchain.core (vchain structure is not flagged
1858 	 * ALLOCATED so it is cleaned out and then left to
1859 	 * rot).
1860 	 */
1861 	dumpcnt = 50;
1862 	hammer2_dump_chain(&hmp->vchain, 0, &dumpcnt, 'v', (u_int)-1);
1863 	dumpcnt = 50;
1864 	hammer2_dump_chain(&hmp->fchain, 0, &dumpcnt, 'f', (u_int)-1);
1865 #if 0
1866 	hammer2_dev_unlock(hmp);
1867 #endif
1868 	hammer2_chain_drop(&hmp->vchain);
1869 
1870 	hammer2_io_cleanup(hmp, &hmp->iotree);
1871 	if (hmp->iofree_count) {
1872 		kprintf("io_cleanup: %d I/O's left hanging\n",
1873 			hmp->iofree_count);
1874 	}
1875 
1876 	TAILQ_REMOVE(&hammer2_mntlist, hmp, mntentry);
1877 	kmalloc_destroy(&hmp->mchain);
1878 	kfree(hmp, M_HAMMER2);
1879 }
1880 
1881 int
1882 hammer2_vfs_vget(struct mount *mp, struct vnode *dvp,
1883 		 ino_t ino, struct vnode **vpp)
1884 {
1885 	hammer2_xop_lookup_t *xop;
1886 	hammer2_pfs_t *pmp;
1887 	hammer2_inode_t *ip;
1888 	hammer2_tid_t inum;
1889 	int error;
1890 
1891 	inum = (hammer2_tid_t)ino & HAMMER2_DIRHASH_USERMSK;
1892 
1893 	error = 0;
1894 	pmp = MPTOPMP(mp);
1895 
1896 	/*
1897 	 * Easy if we already have it cached
1898 	 */
1899 	ip = hammer2_inode_lookup(pmp, inum);
1900 	if (ip) {
1901 		hammer2_inode_lock(ip, HAMMER2_RESOLVE_SHARED);
1902 		*vpp = hammer2_igetv(ip, &error);
1903 		hammer2_inode_unlock(ip);
1904 		hammer2_inode_drop(ip);		/* from lookup */
1905 
1906 		return error;
1907 	}
1908 
1909 	/*
1910 	 * Otherwise we have to find the inode
1911 	 */
1912 	xop = hammer2_xop_alloc(pmp->iroot, 0);
1913 	xop->lhc = inum;
1914 	hammer2_xop_start(&xop->head, &hammer2_lookup_desc);
1915 	error = hammer2_xop_collect(&xop->head, 0);
1916 
1917 	if (error == 0)
1918 		ip = hammer2_inode_get(pmp, &xop->head, -1, -1);
1919 	hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
1920 
1921 	if (ip) {
1922 		*vpp = hammer2_igetv(ip, &error);
1923 		hammer2_inode_unlock(ip);
1924 	} else {
1925 		*vpp = NULL;
1926 		error = ENOENT;
1927 	}
1928 	return (error);
1929 }
1930 
1931 static
1932 int
1933 hammer2_vfs_root(struct mount *mp, struct vnode **vpp)
1934 {
1935 	hammer2_pfs_t *pmp;
1936 	struct vnode *vp;
1937 	int error;
1938 
1939 	pmp = MPTOPMP(mp);
1940 	if (pmp->iroot == NULL) {
1941 		kprintf("hammer2 (%s): no root inode\n",
1942 			mp->mnt_stat.f_mntfromname);
1943 		*vpp = NULL;
1944 		return EINVAL;
1945 	}
1946 
1947 	error = 0;
1948 	hammer2_inode_lock(pmp->iroot, HAMMER2_RESOLVE_SHARED);
1949 
1950 	while (pmp->inode_tid == 0) {
1951 		hammer2_xop_ipcluster_t *xop;
1952 		const hammer2_inode_meta_t *meta;
1953 
1954 		xop = hammer2_xop_alloc(pmp->iroot, HAMMER2_XOP_MODIFYING);
1955 		hammer2_xop_start(&xop->head, &hammer2_ipcluster_desc);
1956 		error = hammer2_xop_collect(&xop->head, 0);
1957 
1958 		if (error == 0) {
1959 			meta = &hammer2_xop_gdata(&xop->head)->ipdata.meta;
1960 			pmp->iroot->meta = *meta;
1961 			pmp->inode_tid = meta->pfs_inum + 1;
1962 			hammer2_xop_pdata(&xop->head);
1963 			/* meta invalid */
1964 
1965 			if (pmp->inode_tid < HAMMER2_INODE_START)
1966 				pmp->inode_tid = HAMMER2_INODE_START;
1967 			pmp->modify_tid =
1968 				xop->head.cluster.focus->bref.modify_tid + 1;
1969 #if 0
1970 			kprintf("PFS: Starting inode %jd\n",
1971 				(intmax_t)pmp->inode_tid);
1972 			kprintf("PMP focus good set nextino=%ld mod=%016jx\n",
1973 				pmp->inode_tid, pmp->modify_tid);
1974 #endif
1975 			wakeup(&pmp->iroot);
1976 
1977 			hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
1978 
1979 			/*
1980 			 * Prime the mount info.
1981 			 */
1982 			hammer2_vfs_statfs(mp, &mp->mnt_stat, NULL);
1983 			break;
1984 		}
1985 
1986 		/*
1987 		 * Loop, try again
1988 		 */
1989 		hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
1990 		hammer2_inode_unlock(pmp->iroot);
1991 		error = tsleep(&pmp->iroot, PCATCH, "h2root", hz);
1992 		hammer2_inode_lock(pmp->iroot, HAMMER2_RESOLVE_SHARED);
1993 		if (error == EINTR)
1994 			break;
1995 	}
1996 
1997 	if (error) {
1998 		hammer2_inode_unlock(pmp->iroot);
1999 		*vpp = NULL;
2000 	} else {
2001 		vp = hammer2_igetv(pmp->iroot, &error);
2002 		hammer2_inode_unlock(pmp->iroot);
2003 		*vpp = vp;
2004 	}
2005 
2006 	return (error);
2007 }
2008 
2009 /*
2010  * Filesystem status
2011  *
2012  * XXX incorporate ipdata->meta.inode_quota and data_quota
2013  */
2014 static
2015 int
2016 hammer2_vfs_statfs(struct mount *mp, struct statfs *sbp, struct ucred *cred)
2017 {
2018 	hammer2_pfs_t *pmp;
2019 	hammer2_dev_t *hmp;
2020 	hammer2_blockref_t bref;
2021 	struct statfs tmp;
2022 	int i;
2023 
2024 	/*
2025 	 * NOTE: iroot might not have validated the cluster yet.
2026 	 */
2027 	pmp = MPTOPMP(mp);
2028 
2029 	bzero(&tmp, sizeof(tmp));
2030 
2031 	for (i = 0; i < pmp->iroot->cluster.nchains; ++i) {
2032 		hmp = pmp->pfs_hmps[i];
2033 		if (hmp == NULL)
2034 			continue;
2035 		if (pmp->iroot->cluster.array[i].chain)
2036 			bref = pmp->iroot->cluster.array[i].chain->bref;
2037 		else
2038 			bzero(&bref, sizeof(bref));
2039 
2040 		tmp.f_files = bref.embed.stats.inode_count;
2041 		tmp.f_ffree = 0;
2042 		tmp.f_blocks = hmp->voldata.allocator_size /
2043 			       mp->mnt_vstat.f_bsize;
2044 		tmp.f_bfree = hmp->voldata.allocator_free /
2045 			      mp->mnt_vstat.f_bsize;
2046 		tmp.f_bavail = tmp.f_bfree;
2047 
2048 		if (cred && cred->cr_uid != 0) {
2049 			uint64_t adj;
2050 
2051 			/* 5% */
2052 			adj = hmp->free_reserved / mp->mnt_vstat.f_bsize;
2053 			tmp.f_blocks -= adj;
2054 			tmp.f_bfree -= adj;
2055 			tmp.f_bavail -= adj;
2056 		}
2057 
2058 		mp->mnt_stat.f_blocks = tmp.f_blocks;
2059 		mp->mnt_stat.f_bfree = tmp.f_bfree;
2060 		mp->mnt_stat.f_bavail = tmp.f_bavail;
2061 		mp->mnt_stat.f_files = tmp.f_files;
2062 		mp->mnt_stat.f_ffree = tmp.f_ffree;
2063 
2064 		*sbp = mp->mnt_stat;
2065 	}
2066 	return (0);
2067 }
2068 
2069 static
2070 int
2071 hammer2_vfs_statvfs(struct mount *mp, struct statvfs *sbp, struct ucred *cred)
2072 {
2073 	hammer2_pfs_t *pmp;
2074 	hammer2_dev_t *hmp;
2075 	hammer2_blockref_t bref;
2076 	struct statvfs tmp;
2077 	int i;
2078 
2079 	/*
2080 	 * NOTE: iroot might not have validated the cluster yet.
2081 	 */
2082 	pmp = MPTOPMP(mp);
2083 	bzero(&tmp, sizeof(tmp));
2084 
2085 	for (i = 0; i < pmp->iroot->cluster.nchains; ++i) {
2086 		hmp = pmp->pfs_hmps[i];
2087 		if (hmp == NULL)
2088 			continue;
2089 		if (pmp->iroot->cluster.array[i].chain)
2090 			bref = pmp->iroot->cluster.array[i].chain->bref;
2091 		else
2092 			bzero(&bref, sizeof(bref));
2093 
2094 		tmp.f_files = bref.embed.stats.inode_count;
2095 		tmp.f_ffree = 0;
2096 		tmp.f_blocks = hmp->voldata.allocator_size /
2097 			       mp->mnt_vstat.f_bsize;
2098 		tmp.f_bfree = hmp->voldata.allocator_free /
2099 			      mp->mnt_vstat.f_bsize;
2100 		tmp.f_bavail = tmp.f_bfree;
2101 
2102 		if (cred && cred->cr_uid != 0) {
2103 			uint64_t adj;
2104 
2105 			/* 5% */
2106 			adj = hmp->free_reserved / mp->mnt_vstat.f_bsize;
2107 			tmp.f_blocks -= adj;
2108 			tmp.f_bfree -= adj;
2109 			tmp.f_bavail -= adj;
2110 		}
2111 
2112 		mp->mnt_vstat.f_blocks = tmp.f_blocks;
2113 		mp->mnt_vstat.f_bfree = tmp.f_bfree;
2114 		mp->mnt_vstat.f_bavail = tmp.f_bavail;
2115 		mp->mnt_vstat.f_files = tmp.f_files;
2116 		mp->mnt_vstat.f_ffree = tmp.f_ffree;
2117 
2118 		*sbp = mp->mnt_vstat;
2119 	}
2120 	return (0);
2121 }
2122 
2123 /*
2124  * Mount-time recovery (RW mounts)
2125  *
2126  * Updates to the free block table are allowed to lag flushes by one
2127  * transaction.  In case of a crash, then on a fresh mount we must do an
2128  * incremental scan of the last committed transaction id and make sure that
2129  * all related blocks have been marked allocated.
2130  *
2131  * The super-root topology and each PFS has its own transaction id domain,
2132  * so we must track PFS boundary transitions.
2133  */
2134 struct hammer2_recovery_elm {
2135 	TAILQ_ENTRY(hammer2_recovery_elm) entry;
2136 	hammer2_chain_t *chain;
2137 	hammer2_tid_t sync_tid;
2138 };
2139 
2140 TAILQ_HEAD(hammer2_recovery_list, hammer2_recovery_elm);
2141 
2142 struct hammer2_recovery_info {
2143 	struct hammer2_recovery_list list;
2144 	hammer2_tid_t	mtid;
2145 	int	depth;
2146 };
2147 
2148 static int hammer2_recovery_scan(hammer2_dev_t *hmp,
2149 			hammer2_chain_t *parent,
2150 			struct hammer2_recovery_info *info,
2151 			hammer2_tid_t sync_tid);
2152 
2153 #define HAMMER2_RECOVERY_MAXDEPTH	10
2154 
2155 static
2156 int
2157 hammer2_recovery(hammer2_dev_t *hmp)
2158 {
2159 	struct hammer2_recovery_info info;
2160 	struct hammer2_recovery_elm *elm;
2161 	hammer2_chain_t *parent;
2162 	hammer2_tid_t sync_tid;
2163 	hammer2_tid_t mirror_tid;
2164 	int error;
2165 
2166 	hammer2_trans_init(hmp->spmp, 0);
2167 
2168 	sync_tid = hmp->voldata.freemap_tid;
2169 	mirror_tid = hmp->voldata.mirror_tid;
2170 
2171 	kprintf("hammer2 mount \"%s\": ", hmp->devrepname);
2172 	if (sync_tid >= mirror_tid) {
2173 		kprintf(" no recovery needed\n");
2174 	} else {
2175 		kprintf(" freemap recovery %016jx-%016jx\n",
2176 			sync_tid + 1, mirror_tid);
2177 	}
2178 
2179 	TAILQ_INIT(&info.list);
2180 	info.depth = 0;
2181 	parent = hammer2_chain_lookup_init(&hmp->vchain, 0);
2182 	error = hammer2_recovery_scan(hmp, parent, &info, sync_tid);
2183 	hammer2_chain_lookup_done(parent);
2184 
2185 	while ((elm = TAILQ_FIRST(&info.list)) != NULL) {
2186 		TAILQ_REMOVE(&info.list, elm, entry);
2187 		parent = elm->chain;
2188 		sync_tid = elm->sync_tid;
2189 		kfree(elm, M_HAMMER2);
2190 
2191 		hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS);
2192 		error |= hammer2_recovery_scan(hmp, parent, &info,
2193 					      hmp->voldata.freemap_tid);
2194 		hammer2_chain_unlock(parent);
2195 		hammer2_chain_drop(parent);	/* drop elm->chain ref */
2196 	}
2197 
2198 	hammer2_trans_done(hmp->spmp, 0);
2199 
2200 	return error;
2201 }
2202 
2203 static
2204 int
2205 hammer2_recovery_scan(hammer2_dev_t *hmp, hammer2_chain_t *parent,
2206 		      struct hammer2_recovery_info *info,
2207 		      hammer2_tid_t sync_tid)
2208 {
2209 	const hammer2_inode_data_t *ripdata;
2210 	hammer2_chain_t *chain;
2211 	hammer2_blockref_t bref;
2212 	int tmp_error;
2213 	int rup_error;
2214 	int error;
2215 	int first;
2216 
2217 	/*
2218 	 * Adjust freemap to ensure that the block(s) are marked allocated.
2219 	 */
2220 	if (parent->bref.type != HAMMER2_BREF_TYPE_VOLUME) {
2221 		hammer2_freemap_adjust(hmp, &parent->bref,
2222 				       HAMMER2_FREEMAP_DORECOVER);
2223 	}
2224 
2225 	/*
2226 	 * Check type for recursive scan
2227 	 */
2228 	switch(parent->bref.type) {
2229 	case HAMMER2_BREF_TYPE_VOLUME:
2230 		/* data already instantiated */
2231 		break;
2232 	case HAMMER2_BREF_TYPE_INODE:
2233 		/*
2234 		 * Must instantiate data for DIRECTDATA test and also
2235 		 * for recursion.
2236 		 */
2237 		hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS);
2238 		ripdata = &hammer2_chain_rdata(parent)->ipdata;
2239 		if (ripdata->meta.op_flags & HAMMER2_OPFLAG_DIRECTDATA) {
2240 			/* not applicable to recovery scan */
2241 			hammer2_chain_unlock(parent);
2242 			return 0;
2243 		}
2244 		hammer2_chain_unlock(parent);
2245 		break;
2246 	case HAMMER2_BREF_TYPE_INDIRECT:
2247 		/*
2248 		 * Must instantiate data for recursion
2249 		 */
2250 		hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS);
2251 		hammer2_chain_unlock(parent);
2252 		break;
2253 	case HAMMER2_BREF_TYPE_DIRENT:
2254 	case HAMMER2_BREF_TYPE_DATA:
2255 	case HAMMER2_BREF_TYPE_FREEMAP:
2256 	case HAMMER2_BREF_TYPE_FREEMAP_NODE:
2257 	case HAMMER2_BREF_TYPE_FREEMAP_LEAF:
2258 		/* not applicable to recovery scan */
2259 		return 0;
2260 		break;
2261 	default:
2262 		return HAMMER2_ERROR_BADBREF;
2263 	}
2264 
2265 	/*
2266 	 * Defer operation if depth limit reached or if we are crossing a
2267 	 * PFS boundary.
2268 	 */
2269 	if (info->depth >= HAMMER2_RECOVERY_MAXDEPTH) {
2270 		struct hammer2_recovery_elm *elm;
2271 
2272 		elm = kmalloc(sizeof(*elm), M_HAMMER2, M_ZERO | M_WAITOK);
2273 		elm->chain = parent;
2274 		elm->sync_tid = sync_tid;
2275 		hammer2_chain_ref(parent);
2276 		TAILQ_INSERT_TAIL(&info->list, elm, entry);
2277 		/* unlocked by caller */
2278 
2279 		return(0);
2280 	}
2281 
2282 
2283 	/*
2284 	 * Recursive scan of the last flushed transaction only.  We are
2285 	 * doing this without pmp assignments so don't leave the chains
2286 	 * hanging around after we are done with them.
2287 	 *
2288 	 * error	Cumulative error this level only
2289 	 * rup_error	Cumulative error for recursion
2290 	 * tmp_error	Specific non-cumulative recursion error
2291 	 */
2292 	chain = NULL;
2293 	first = 1;
2294 	rup_error = 0;
2295 	error = 0;
2296 
2297 	for (;;) {
2298 		error |= hammer2_chain_scan(parent, &chain, &bref,
2299 					    &first,
2300 					    HAMMER2_LOOKUP_NODATA);
2301 
2302 		/*
2303 		 * Problem during scan or EOF
2304 		 */
2305 		if (error)
2306 			break;
2307 
2308 		/*
2309 		 * If this is a leaf
2310 		 */
2311 		if (chain == NULL) {
2312 			if (bref.mirror_tid > sync_tid) {
2313 				hammer2_freemap_adjust(hmp, &bref,
2314 						     HAMMER2_FREEMAP_DORECOVER);
2315 			}
2316 			continue;
2317 		}
2318 
2319 		/*
2320 		 * This may or may not be a recursive node.
2321 		 */
2322 		atomic_set_int(&chain->flags, HAMMER2_CHAIN_RELEASE);
2323 		if (bref.mirror_tid > sync_tid) {
2324 			++info->depth;
2325 			tmp_error = hammer2_recovery_scan(hmp, chain,
2326 							   info, sync_tid);
2327 			--info->depth;
2328 		} else {
2329 			tmp_error = 0;
2330 		}
2331 
2332 		/*
2333 		 * Flush the recovery at the PFS boundary to stage it for
2334 		 * the final flush of the super-root topology.
2335 		 */
2336 		if (tmp_error == 0 &&
2337 		    (bref.flags & HAMMER2_BREF_FLAG_PFSROOT) &&
2338 		    (chain->flags & HAMMER2_CHAIN_ONFLUSH)) {
2339 			hammer2_flush(chain, HAMMER2_FLUSH_TOP |
2340 					     HAMMER2_FLUSH_ALL);
2341 		}
2342 		rup_error |= tmp_error;
2343 	}
2344 	return ((error | rup_error) & ~HAMMER2_ERROR_EOF);
2345 }
2346 
2347 /*
2348  * This fixes up an error introduced in earlier H2 implementations where
2349  * moving a PFS inode into an indirect block wound up causing the
2350  * HAMMER2_BREF_FLAG_PFSROOT flag in the bref to get cleared.
2351  */
2352 static
2353 int
2354 hammer2_fixup_pfses(hammer2_dev_t *hmp)
2355 {
2356 	const hammer2_inode_data_t *ripdata;
2357 	hammer2_chain_t *parent;
2358 	hammer2_chain_t *chain;
2359 	hammer2_key_t key_next;
2360 	hammer2_pfs_t *spmp;
2361 	int error;
2362 
2363 	error = 0;
2364 
2365 	/*
2366 	 * Lookup mount point under the media-localized super-root.
2367 	 *
2368 	 * cluster->pmp will incorrectly point to spmp and must be fixed
2369 	 * up later on.
2370 	 */
2371 	spmp = hmp->spmp;
2372 	hammer2_inode_lock(spmp->iroot, 0);
2373 	parent = hammer2_inode_chain(spmp->iroot, 0, HAMMER2_RESOLVE_ALWAYS);
2374 	chain = hammer2_chain_lookup(&parent, &key_next,
2375 					 HAMMER2_KEY_MIN, HAMMER2_KEY_MAX,
2376 					 &error, 0);
2377 	while (chain) {
2378 		if (chain->bref.type != HAMMER2_BREF_TYPE_INODE)
2379 			continue;
2380 		if (chain->error) {
2381 			kprintf("I/O error scanning PFS labels\n");
2382 			error |= chain->error;
2383 		} else if ((chain->bref.flags &
2384 			    HAMMER2_BREF_FLAG_PFSROOT) == 0) {
2385 			int error2;
2386 
2387 			ripdata = &chain->data->ipdata;
2388 			hammer2_trans_init(hmp->spmp, 0);
2389 			error2 = hammer2_chain_modify(chain,
2390 						      chain->bref.modify_tid,
2391 						      0, 0);
2392 			if (error2 == 0) {
2393 				kprintf("hammer2: Correct mis-flagged PFS %s\n",
2394 					ripdata->filename);
2395 				chain->bref.flags |= HAMMER2_BREF_FLAG_PFSROOT;
2396 			} else {
2397 				error |= error2;
2398 			}
2399 			hammer2_flush(chain, HAMMER2_FLUSH_TOP |
2400 					     HAMMER2_FLUSH_ALL);
2401 			hammer2_trans_done(hmp->spmp, 0);
2402 		}
2403 		chain = hammer2_chain_next(&parent, chain, &key_next,
2404 					   key_next, HAMMER2_KEY_MAX,
2405 					   &error, 0);
2406 	}
2407 	if (parent) {
2408 		hammer2_chain_unlock(parent);
2409 		hammer2_chain_drop(parent);
2410 	}
2411 	hammer2_inode_unlock(spmp->iroot);
2412 
2413 	return error;
2414 }
2415 
2416 /*
2417  * Sync a mount point; this is called periodically on a per-mount basis from
2418  * the filesystem syncer, and whenever a user issues a sync.
2419  */
2420 int
2421 hammer2_vfs_sync(struct mount *mp, int waitfor)
2422 {
2423 	int error;
2424 
2425 	error = hammer2_vfs_sync_pmp(MPTOPMP(mp), waitfor);
2426 
2427 	return error;
2428 }
2429 
2430 /*
2431  * Because frontend operations lock vnodes before we get a chance to
2432  * lock the related inode, we can't just acquire a vnode lock without
2433  * risking a deadlock.  The frontend may be holding a vnode lock while
2434  * also blocked on our SYNCQ flag while trying to get the inode lock.
2435  *
2436  * To deal with this situation we can check the vnode lock situation
2437  * after locking the inode and perform a work-around.
2438  */
2439 int
2440 hammer2_vfs_sync_pmp(hammer2_pfs_t *pmp, int waitfor)
2441 {
2442 	struct mount *mp;
2443 	/*hammer2_xop_flush_t *xop;*/
2444 	/*struct hammer2_sync_info info;*/
2445 	hammer2_inode_t *ip;
2446 	hammer2_depend_t *depend;
2447 	hammer2_depend_t *depend_next;
2448 	struct vnode *vp;
2449 	uint32_t pass2;
2450 	int error;
2451 	int dorestart;
2452 
2453 	mp = pmp->mp;
2454 
2455 	/*
2456 	 * Move all inodes on sideq to syncq.  This will clear sideq.
2457 	 * This should represent all flushable inodes.  These inodes
2458 	 * will already have refs due to being on syncq or sideq.  We
2459 	 * must do this all at once with the spinlock held to ensure that
2460 	 * all inode dependencies are part of the same flush.
2461 	 *
2462 	 * We should be able to do this asynchronously from frontend
2463 	 * operations because we will be locking the inodes later on
2464 	 * to actually flush them, and that will partition any frontend
2465 	 * op using the same inode.  Either it has already locked the
2466 	 * inode and we will block, or it has not yet locked the inode
2467 	 * and it will block until we are finished flushing that inode.
2468 	 *
2469 	 * When restarting, only move the inodes flagged as PASS2 from
2470 	 * SIDEQ to SYNCQ.  PASS2 propagation by inode_lock4() and
2471 	 * inode_depend() are atomic with the spin-lock.
2472 	 */
2473 	hammer2_trans_init(pmp, HAMMER2_TRANS_ISFLUSH);
2474 #ifdef HAMMER2_DEBUG_SYNC
2475 	kprintf("FILESYSTEM SYNC BOUNDARY\n");
2476 #endif
2477 	dorestart = 0;
2478 
2479 	/*
2480 	 * Move inodes from depq to syncq, releasing the related
2481 	 * depend structures.
2482 	 */
2483 restart:
2484 #ifdef HAMMER2_DEBUG_SYNC
2485 	kprintf("FILESYSTEM SYNC RESTART (%d)\n", dorestart);
2486 #endif
2487 	hammer2_trans_setflags(pmp, 0/*HAMMER2_TRANS_COPYQ*/);
2488 	hammer2_trans_clearflags(pmp, HAMMER2_TRANS_RESCAN);
2489 
2490 	/*
2491 	 * Move inodes from depq to syncq.  When restarting, only depq's
2492 	 * marked pass2 are moved.
2493 	 */
2494 	hammer2_spin_ex(&pmp->list_spin);
2495 	depend_next = TAILQ_FIRST(&pmp->depq);
2496 
2497 	while ((depend = depend_next) != NULL) {
2498 		depend_next = TAILQ_NEXT(depend, entry);
2499 		if (dorestart && depend->pass2 == 0)
2500 			continue;
2501 		TAILQ_FOREACH(ip, &depend->sideq, entry) {
2502 			KKASSERT(ip->flags & HAMMER2_INODE_SIDEQ);
2503 			atomic_set_int(&ip->flags, HAMMER2_INODE_SYNCQ);
2504 			atomic_clear_int(&ip->flags, HAMMER2_INODE_SIDEQ);
2505 			ip->depend = NULL;
2506 		}
2507 		TAILQ_CONCAT(&pmp->syncq, &depend->sideq, entry);
2508 		pmp->sideq_count -= depend->count;
2509 		depend->count = 0;
2510 		depend->pass2 = 0;
2511 		TAILQ_REMOVE(&pmp->depq, depend, entry);
2512 	}
2513 
2514 	hammer2_spin_unex(&pmp->list_spin);
2515 	hammer2_trans_clearflags(pmp, /*HAMMER2_TRANS_COPYQ |*/
2516 				      HAMMER2_TRANS_WAITING);
2517 	dorestart = 0;
2518 
2519 	/*
2520 	 * sideq_count may have dropped enough to allow us to unstall
2521 	 * the frontend.
2522 	 */
2523 	hammer2_pfs_memory_inc(pmp);
2524 	hammer2_pfs_memory_wakeup(pmp);
2525 
2526 	/*
2527 	 * Now run through all inodes on syncq.
2528 	 *
2529 	 * Flush transactions only interlock with other flush transactions.
2530 	 * Any conflicting frontend operations will block on the inode, but
2531 	 * may hold a vnode lock while doing so.
2532 	 */
2533 	hammer2_spin_ex(&pmp->list_spin);
2534 	while ((ip = TAILQ_FIRST(&pmp->syncq)) != NULL) {
2535 		/*
2536 		 * Remove the inode from the SYNCQ, transfer the syncq ref
2537 		 * to us.  We must clear SYNCQ to allow any potential
2538 		 * front-end deadlock to proceed.  We must set PASS2 so
2539 		 * the dependency code knows what to do.
2540 		 */
2541 		pass2 = ip->flags;
2542 		cpu_ccfence();
2543 		if (atomic_cmpset_int(&ip->flags,
2544 			      pass2,
2545 			      (pass2 & ~(HAMMER2_INODE_SYNCQ |
2546 					 HAMMER2_INODE_SYNCQ_WAKEUP)) |
2547 			      HAMMER2_INODE_SYNCQ_PASS2) == 0) {
2548 			continue;
2549 		}
2550 		TAILQ_REMOVE(&pmp->syncq, ip, entry);
2551 		hammer2_spin_unex(&pmp->list_spin);
2552 		if (pass2 & HAMMER2_INODE_SYNCQ_WAKEUP)
2553 			wakeup(&ip->flags);
2554 
2555 		/*
2556 		 * Relock the inode, and we inherit a ref from the above.
2557 		 * We will check for a race after we acquire the vnode.
2558 		 */
2559 		hammer2_mtx_ex(&ip->lock);
2560 
2561 		/*
2562 		 * We need the vp in order to vfsync() dirty buffers, so if
2563 		 * one isn't attached we can skip it.
2564 		 *
2565 		 * Ordering the inode lock and then the vnode lock has the
2566 		 * potential to deadlock.  If we had left SYNCQ set that could
2567 		 * also deadlock us against the frontend even if we don't hold
2568 		 * any locks, but the latter is not a problem now since we
2569 		 * cleared it.  igetv will temporarily release the inode lock
2570 		 * in a safe manner to work-around the deadlock.
2571 		 *
2572 		 * Unfortunately it is still possible to deadlock when the
2573 		 * frontend obtains multiple inode locks, because all the
2574 		 * related vnodes are already locked (nor can the vnode locks
2575 		 * be released and reacquired without messing up RECLAIM and
2576 		 * INACTIVE sequencing).
2577 		 *
2578 		 * The solution for now is to move the vp back onto SIDEQ
2579 		 * and set dorestart, which will restart the flush after we
2580 		 * exhaust the current SYNCQ.  Note that additional
2581 		 * dependencies may build up, so we definitely need to move
2582 		 * the whole SIDEQ back to SYNCQ when we restart.
2583 		 */
2584 		vp = ip->vp;
2585 		if (vp) {
2586 			if (vget(vp, LK_EXCLUSIVE|LK_NOWAIT)) {
2587 				/*
2588 				 * Failed to get the vnode, requeue the inode
2589 				 * (PASS2 is already set so it will be found
2590 				 * again on the restart).
2591 				 *
2592 				 * Then unlock, possibly sleep, and retry
2593 				 * later.  We sleep if PASS2 was *previously*
2594 				 * set, before we set it again above.
2595 				 */
2596 				vp = NULL;
2597 				dorestart = 1;
2598 #ifdef HAMMER2_DEBUG_SYNC
2599 				kprintf("inum %ld (sync delayed by vnode)\n",
2600 					(long)ip->meta.inum);
2601 #endif
2602 				hammer2_inode_delayed_sideq(ip);
2603 
2604 				hammer2_mtx_unlock(&ip->lock);
2605 				hammer2_inode_drop(ip);
2606 
2607 				if (pass2 & HAMMER2_INODE_SYNCQ_PASS2) {
2608 					tsleep(&dorestart, 0, "h2syndel", 2);
2609 				}
2610 				hammer2_spin_ex(&pmp->list_spin);
2611 				continue;
2612 			}
2613 		} else {
2614 			vp = NULL;
2615 		}
2616 
2617 		/*
2618 		 * If the inode wound up on a SIDEQ again it will already be
2619 		 * prepped for another PASS2.  In this situation if we flush
2620 		 * it now we will just wind up flushing it again in the same
2621 		 * syncer run, so we might as well not flush it now.
2622 		 */
2623 		if (ip->flags & HAMMER2_INODE_SIDEQ) {
2624 			hammer2_mtx_unlock(&ip->lock);
2625 			hammer2_inode_drop(ip);
2626 			if (vp)
2627 				vput(vp);
2628 			dorestart = 1;
2629 			hammer2_spin_ex(&pmp->list_spin);
2630 			continue;
2631 		}
2632 
2633 		/*
2634 		 * Ok we have the inode exclusively locked and if vp is
2635 		 * not NULL that will also be exclusively locked.  Do the
2636 		 * meat of the flush.
2637 		 *
2638 		 * vp token needed for v_rbdirty_tree check / vclrisdirty
2639 		 * sequencing.  Though we hold the vnode exclusively so
2640 		 * we shouldn't need to hold the token also in this case.
2641 		 */
2642 		if (vp) {
2643 			vfsync(vp, MNT_WAIT, 1, NULL, NULL);
2644 			bio_track_wait(&vp->v_track_write, 0, 0); /* XXX */
2645 		}
2646 
2647 		/*
2648 		 * If the inode has not yet been inserted into the tree
2649 		 * we must do so.  Then sync and flush it.  The flush should
2650 		 * update the parent.
2651 		 */
2652 		if (ip->flags & HAMMER2_INODE_DELETING) {
2653 #ifdef HAMMER2_DEBUG_SYNC
2654 			kprintf("inum %ld destroy\n", (long)ip->meta.inum);
2655 #endif
2656 			hammer2_inode_chain_des(ip);
2657 			atomic_add_long(&hammer2_iod_inode_deletes, 1);
2658 		} else if (ip->flags & HAMMER2_INODE_CREATING) {
2659 #ifdef HAMMER2_DEBUG_SYNC
2660 			kprintf("inum %ld insert\n", (long)ip->meta.inum);
2661 #endif
2662 			hammer2_inode_chain_ins(ip);
2663 			atomic_add_long(&hammer2_iod_inode_creates, 1);
2664 		}
2665 #ifdef HAMMER2_DEBUG_SYNC
2666 		kprintf("inum %ld chain-sync\n", (long)ip->meta.inum);
2667 #endif
2668 
2669 		/*
2670 		 * Because I kinda messed up the design and index the inodes
2671 		 * under the root inode, along side the directory entries,
2672 		 * we can't flush the inode index under the iroot until the
2673 		 * end.  If we do it now we might miss effects created by
2674 		 * other inodes on the SYNCQ.
2675 		 *
2676 		 * Do a normal (non-FSSYNC) flush instead, which allows the
2677 		 * vnode code to work the same.  We don't want to force iroot
2678 		 * back onto the SIDEQ, and we also don't want the flush code
2679 		 * to update pfs_iroot_blocksets until the final flush later.
2680 		 *
2681 		 * XXX at the moment this will likely result in a double-flush
2682 		 * of the iroot chain.
2683 		 */
2684 		hammer2_inode_chain_sync(ip);
2685 		if (ip == pmp->iroot) {
2686 			hammer2_inode_chain_flush(ip, HAMMER2_XOP_INODE_STOP);
2687 		} else {
2688 			hammer2_inode_chain_flush(ip, HAMMER2_XOP_INODE_STOP |
2689 						      HAMMER2_XOP_FSSYNC);
2690 		}
2691 		if (vp) {
2692 			lwkt_gettoken(&vp->v_token);
2693 			if ((ip->flags & (HAMMER2_INODE_MODIFIED |
2694 					  HAMMER2_INODE_RESIZED |
2695 					  HAMMER2_INODE_DIRTYDATA)) == 0 &&
2696 			    RB_EMPTY(&vp->v_rbdirty_tree) &&
2697 			    !bio_track_active(&vp->v_track_write)) {
2698 				vclrisdirty(vp);
2699 			} else {
2700 				hammer2_inode_delayed_sideq(ip);
2701 			}
2702 			lwkt_reltoken(&vp->v_token);
2703 			vput(vp);
2704 			vp = NULL;	/* safety */
2705 		}
2706 		atomic_clear_int(&ip->flags, HAMMER2_INODE_SYNCQ_PASS2);
2707 		hammer2_inode_unlock(ip);	/* unlock+drop */
2708 		/* ip pointer invalid */
2709 
2710 		/*
2711 		 * If the inode got dirted after we dropped our locks,
2712 		 * it will have already been moved back to the SIDEQ.
2713 		 */
2714 		hammer2_spin_ex(&pmp->list_spin);
2715 	}
2716 	hammer2_spin_unex(&pmp->list_spin);
2717 	if (dorestart || (pmp->trans.flags & HAMMER2_TRANS_RESCAN)) {
2718 #ifdef HAMMER2_DEBUG_SYNC
2719 		kprintf("FILESYSTEM SYNC STAGE 1 RESTART\n");
2720 		/*tsleep(&dorestart, 0, "h2STG1-R", hz*20);*/
2721 #endif
2722 		dorestart = 1;
2723 		goto restart;
2724 	}
2725 #ifdef HAMMER2_DEBUG_SYNC
2726 	kprintf("FILESYSTEM SYNC STAGE 2 BEGIN\n");
2727 	/*tsleep(&dorestart, 0, "h2STG2", hz*20);*/
2728 #endif
2729 
2730 	/*
2731 	 * We have to flush the PFS root last, even if it does not appear to
2732 	 * be dirty, because all the inodes in the PFS are indexed under it.
2733 	 * The normal flushing of iroot above would only occur if directory
2734 	 * entries under the root were changed.
2735 	 *
2736 	 * Specifying VOLHDR will cause an additionl flush of hmp->spmp
2737 	 * for the media making up the cluster.
2738 	 */
2739 	if ((ip = pmp->iroot) != NULL) {
2740 		hammer2_inode_ref(ip);
2741 		hammer2_mtx_ex(&ip->lock);
2742 		hammer2_inode_chain_sync(ip);
2743 		hammer2_inode_chain_flush(ip, HAMMER2_XOP_INODE_STOP |
2744 					      HAMMER2_XOP_FSSYNC |
2745 					      HAMMER2_XOP_VOLHDR);
2746 		hammer2_inode_unlock(ip);	/* unlock+drop */
2747 	}
2748 #ifdef HAMMER2_DEBUG_SYNC
2749 	kprintf("FILESYSTEM SYNC STAGE 2 DONE\n");
2750 #endif
2751 
2752 	/*
2753 	 * device bioq sync
2754 	 */
2755 	hammer2_bioq_sync(pmp);
2756 
2757 #if 0
2758 	info.pass = 1;
2759 	info.waitfor = MNT_WAIT;
2760 	vsyncscan(mp, flags, hammer2_sync_scan2, &info);
2761 
2762 	info.pass = 2;
2763 	info.waitfor = MNT_WAIT;
2764 	vsyncscan(mp, flags, hammer2_sync_scan2, &info);
2765 #endif
2766 #if 0
2767 	/*
2768 	 * Generally speaking we now want to flush the media topology from
2769 	 * the iroot through to the inodes.  The flush stops at any inode
2770 	 * boundary, which allows the frontend to continue running concurrent
2771 	 * modifying operations on inodes (including kernel flushes of
2772 	 * buffers) without interfering with the main sync.
2773 	 *
2774 	 * Use the XOP interface to concurrently flush all nodes to
2775 	 * synchronize the PFSROOT subtopology to the media.  A standard
2776 	 * end-of-scan ENOENT error indicates cluster sufficiency.
2777 	 *
2778 	 * Note that this flush will not be visible on crash recovery until
2779 	 * we flush the super-root topology in the next loop.
2780 	 *
2781 	 * XXX For now wait for all flushes to complete.
2782 	 */
2783 	if (mp && (ip = pmp->iroot) != NULL) {
2784 		/*
2785 		 * If unmounting try to flush everything including any
2786 		 * sub-trees under inodes, just in case there is dangling
2787 		 * modified data, as a safety.  Otherwise just flush up to
2788 		 * the inodes in this stage.
2789 		 */
2790 		kprintf("MP & IROOT\n");
2791 #ifdef HAMMER2_DEBUG_SYNC
2792 		kprintf("FILESYSTEM SYNC STAGE 3 IROOT BEGIN\n");
2793 #endif
2794 		if (mp->mnt_kern_flag & MNTK_UNMOUNT) {
2795 			xop = hammer2_xop_alloc(ip, HAMMER2_XOP_MODIFYING |
2796 						    HAMMER2_XOP_VOLHDR |
2797 						    HAMMER2_XOP_FSSYNC |
2798 						    HAMMER2_XOP_INODE_STOP);
2799 		} else {
2800 			xop = hammer2_xop_alloc(ip, HAMMER2_XOP_MODIFYING |
2801 						    HAMMER2_XOP_INODE_STOP |
2802 						    HAMMER2_XOP_VOLHDR |
2803 						    HAMMER2_XOP_FSSYNC |
2804 						    HAMMER2_XOP_INODE_STOP);
2805 		}
2806 		hammer2_xop_start(&xop->head, &hammer2_inode_flush_desc);
2807 		error = hammer2_xop_collect(&xop->head,
2808 					    HAMMER2_XOP_COLLECT_WAITALL);
2809 		hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
2810 #ifdef HAMMER2_DEBUG_SYNC
2811 		kprintf("FILESYSTEM SYNC STAGE 3 IROOT END\n");
2812 #endif
2813 		if (error == HAMMER2_ERROR_ENOENT)
2814 			error = 0;
2815 		else
2816 			error = hammer2_error_to_errno(error);
2817 	} else {
2818 		error = 0;
2819 	}
2820 #endif
2821 	error = 0;	/* XXX */
2822 	hammer2_trans_done(pmp, HAMMER2_TRANS_ISFLUSH);
2823 
2824 	return (error);
2825 }
2826 
2827 static
2828 int
2829 hammer2_vfs_vptofh(struct vnode *vp, struct fid *fhp)
2830 {
2831 	hammer2_inode_t *ip;
2832 
2833 	KKASSERT(MAXFIDSZ >= 16);
2834 	ip = VTOI(vp);
2835 	fhp->fid_len = offsetof(struct fid, fid_data[16]);
2836 	fhp->fid_ext = 0;
2837 	((hammer2_tid_t *)fhp->fid_data)[0] = ip->meta.inum;
2838 	((hammer2_tid_t *)fhp->fid_data)[1] = 0;
2839 
2840 	return 0;
2841 }
2842 
2843 static
2844 int
2845 hammer2_vfs_fhtovp(struct mount *mp, struct vnode *rootvp,
2846 	       struct fid *fhp, struct vnode **vpp)
2847 {
2848 	hammer2_pfs_t *pmp;
2849 	hammer2_tid_t inum;
2850 	int error;
2851 
2852 	pmp = MPTOPMP(mp);
2853 	inum = ((hammer2_tid_t *)fhp->fid_data)[0] & HAMMER2_DIRHASH_USERMSK;
2854 	if (vpp) {
2855 		if (inum == 1)
2856 			error = hammer2_vfs_root(mp, vpp);
2857 		else
2858 			error = hammer2_vfs_vget(mp, NULL, inum, vpp);
2859 	} else {
2860 		error = 0;
2861 	}
2862 	if (error)
2863 		kprintf("fhtovp: %016jx -> %p, %d\n", inum, *vpp, error);
2864 	return error;
2865 }
2866 
2867 static
2868 int
2869 hammer2_vfs_checkexp(struct mount *mp, struct sockaddr *nam,
2870 		 int *exflagsp, struct ucred **credanonp)
2871 {
2872 	hammer2_pfs_t *pmp;
2873 	struct netcred *np;
2874 	int error;
2875 
2876 	pmp = MPTOPMP(mp);
2877 	np = vfs_export_lookup(mp, &pmp->export, nam);
2878 	if (np) {
2879 		*exflagsp = np->netc_exflags;
2880 		*credanonp = &np->netc_anon;
2881 		error = 0;
2882 	} else {
2883 		error = EACCES;
2884 	}
2885 	return error;
2886 }
2887 
2888 /*
2889  * Support code for hammer2_vfs_mount().  Read, verify, and install the volume
2890  * header into the HMP
2891  *
2892  * XXX read four volhdrs and use the one with the highest TID whos CRC
2893  *     matches.
2894  *
2895  * XXX check iCRCs.
2896  *
2897  * XXX For filesystems w/ less than 4 volhdrs, make sure to not write to
2898  *     nonexistant locations.
2899  *
2900  * XXX Record selected volhdr and ring updates to each of 4 volhdrs
2901  */
2902 static
2903 int
2904 hammer2_install_volume_header(hammer2_dev_t *hmp)
2905 {
2906 	hammer2_volume_data_t *vd;
2907 	struct buf *bp;
2908 	hammer2_crc32_t crc0, crc, bcrc0, bcrc;
2909 	int error_reported;
2910 	int error;
2911 	int valid;
2912 	int i;
2913 
2914 	error_reported = 0;
2915 	error = 0;
2916 	valid = 0;
2917 	bp = NULL;
2918 
2919 	/*
2920 	 * There are up to 4 copies of the volume header (syncs iterate
2921 	 * between them so there is no single master).  We don't trust the
2922 	 * volu_size field so we don't know precisely how large the filesystem
2923 	 * is, so depend on the OS to return an error if we go beyond the
2924 	 * block device's EOF.
2925 	 */
2926 	for (i = 0; i < HAMMER2_NUM_VOLHDRS; i++) {
2927 		error = bread(hmp->devvp, i * HAMMER2_ZONE_BYTES64,
2928 			      HAMMER2_VOLUME_BYTES, &bp);
2929 		if (error) {
2930 			brelse(bp);
2931 			bp = NULL;
2932 			continue;
2933 		}
2934 
2935 		vd = (struct hammer2_volume_data *) bp->b_data;
2936 		if ((vd->magic != HAMMER2_VOLUME_ID_HBO) &&
2937 		    (vd->magic != HAMMER2_VOLUME_ID_ABO)) {
2938 			brelse(bp);
2939 			bp = NULL;
2940 			continue;
2941 		}
2942 
2943 		if (vd->magic == HAMMER2_VOLUME_ID_ABO) {
2944 			/* XXX: Reversed-endianness filesystem */
2945 			kprintf("hammer2: reverse-endian filesystem detected");
2946 			brelse(bp);
2947 			bp = NULL;
2948 			continue;
2949 		}
2950 
2951 		crc = vd->icrc_sects[HAMMER2_VOL_ICRC_SECT0];
2952 		crc0 = hammer2_icrc32(bp->b_data + HAMMER2_VOLUME_ICRC0_OFF,
2953 				      HAMMER2_VOLUME_ICRC0_SIZE);
2954 		bcrc = vd->icrc_sects[HAMMER2_VOL_ICRC_SECT1];
2955 		bcrc0 = hammer2_icrc32(bp->b_data + HAMMER2_VOLUME_ICRC1_OFF,
2956 				       HAMMER2_VOLUME_ICRC1_SIZE);
2957 		if ((crc0 != crc) || (bcrc0 != bcrc)) {
2958 			kprintf("hammer2 volume header crc "
2959 				"mismatch copy #%d %08x/%08x\n",
2960 				i, crc0, crc);
2961 			error_reported = 1;
2962 			brelse(bp);
2963 			bp = NULL;
2964 			continue;
2965 		}
2966 		if (valid == 0 || hmp->voldata.mirror_tid < vd->mirror_tid) {
2967 			valid = 1;
2968 			hmp->voldata = *vd;
2969 			hmp->volhdrno = i;
2970 		}
2971 		brelse(bp);
2972 		bp = NULL;
2973 	}
2974 	if (valid) {
2975 		hmp->volsync = hmp->voldata;
2976 		hmp->free_reserved = hmp->voldata.allocator_size / 20;
2977 		error = 0;
2978 		if (error_reported || bootverbose || 1) { /* 1/DEBUG */
2979 			kprintf("hammer2: using volume header #%d\n",
2980 				hmp->volhdrno);
2981 		}
2982 	} else {
2983 		error = EINVAL;
2984 		kprintf("hammer2: no valid volume headers found!\n");
2985 	}
2986 	return (error);
2987 }
2988 
2989 /*
2990  * This handles hysteresis on regular file flushes.  Because the BIOs are
2991  * routed to a thread it is possible for an excessive number to build up
2992  * and cause long front-end stalls long before the runningbuffspace limit
2993  * is hit, so we implement hammer2_flush_pipe to control the
2994  * hysteresis.
2995  *
2996  * This is a particular problem when compression is used.
2997  */
2998 void
2999 hammer2_lwinprog_ref(hammer2_pfs_t *pmp)
3000 {
3001 	atomic_add_int(&pmp->count_lwinprog, 1);
3002 }
3003 
3004 void
3005 hammer2_lwinprog_drop(hammer2_pfs_t *pmp)
3006 {
3007 	int lwinprog;
3008 
3009 	lwinprog = atomic_fetchadd_int(&pmp->count_lwinprog, -1);
3010 	if ((lwinprog & HAMMER2_LWINPROG_WAITING) &&
3011 	    (lwinprog & HAMMER2_LWINPROG_MASK) <= hammer2_flush_pipe * 2 / 3) {
3012 		atomic_clear_int(&pmp->count_lwinprog,
3013 				 HAMMER2_LWINPROG_WAITING);
3014 		wakeup(&pmp->count_lwinprog);
3015 	}
3016 	if ((lwinprog & HAMMER2_LWINPROG_WAITING0) &&
3017 	    (lwinprog & HAMMER2_LWINPROG_MASK) <= 0) {
3018 		atomic_clear_int(&pmp->count_lwinprog,
3019 				 HAMMER2_LWINPROG_WAITING0);
3020 		wakeup(&pmp->count_lwinprog);
3021 	}
3022 }
3023 
3024 void
3025 hammer2_lwinprog_wait(hammer2_pfs_t *pmp, int flush_pipe)
3026 {
3027 	int lwinprog;
3028 	int lwflag = (flush_pipe) ? HAMMER2_LWINPROG_WAITING :
3029 				    HAMMER2_LWINPROG_WAITING0;
3030 
3031 	for (;;) {
3032 		lwinprog = pmp->count_lwinprog;
3033 		cpu_ccfence();
3034 		if ((lwinprog & HAMMER2_LWINPROG_MASK) <= flush_pipe)
3035 			break;
3036 		tsleep_interlock(&pmp->count_lwinprog, 0);
3037 		atomic_set_int(&pmp->count_lwinprog, lwflag);
3038 		lwinprog = pmp->count_lwinprog;
3039 		if ((lwinprog & HAMMER2_LWINPROG_MASK) <= flush_pipe)
3040 			break;
3041 		tsleep(&pmp->count_lwinprog, PINTERLOCKED, "h2wpipe", hz);
3042 	}
3043 }
3044 
3045 /*
3046  * It is possible for an excessive number of dirty chains or dirty inodes
3047  * to build up.  When this occurs we start an asynchronous filesystem sync.
3048  * If the level continues to build up, we stall, waiting for it to drop,
3049  * with some hysteresis.
3050  *
3051  * We limit the stall to two seconds per call.
3052  *
3053  * This relies on the kernel calling hammer2_vfs_modifying() prior to
3054  * obtaining any vnode locks before making a modifying VOP call.
3055  */
3056 static void
3057 hammer2_vfs_modifying(struct mount *mp)
3058 {
3059 	hammer2_pfs_memory_wait(MPTOPMP(mp));
3060 }
3061 
3062 /*
3063  * Initiate an asynchronous filesystem sync and, with hysteresis,
3064  * stall if the internal data structure count becomes too bloated.
3065  */
3066 void
3067 hammer2_pfs_memory_wait(hammer2_pfs_t *pmp)
3068 {
3069 	uint32_t waiting;
3070 	int loops;
3071 
3072 	if (pmp == NULL || pmp->mp == NULL)
3073 		return;
3074 
3075 	for (loops = 0; loops < 2; ++loops) {
3076 		waiting = pmp->inmem_dirty_chains & HAMMER2_DIRTYCHAIN_MASK;
3077 		cpu_ccfence();
3078 
3079 		/*
3080 		 * Start the syncer running at 1/2 the limit
3081 		 */
3082 		if (waiting > hammer2_limit_dirty_chains / 2 ||
3083 		    pmp->sideq_count > hammer2_limit_dirty_inodes / 2) {
3084 			trigger_syncer(pmp->mp);
3085 		}
3086 
3087 		/*
3088 		 * Stall at the limit waiting for the counts to drop.
3089 		 * This code will typically be woken up once the count
3090 		 * drops below 3/4 the limit, or in one second.
3091 		 */
3092 		if (waiting < hammer2_limit_dirty_chains &&
3093 		    pmp->sideq_count < hammer2_limit_dirty_inodes) {
3094 			break;
3095 		}
3096 		tsleep_interlock(&pmp->inmem_dirty_chains, 0);
3097 		atomic_set_int(&pmp->inmem_dirty_chains,
3098 			       HAMMER2_DIRTYCHAIN_WAITING);
3099 		if (waiting < hammer2_limit_dirty_chains &&
3100 		    pmp->sideq_count < hammer2_limit_dirty_inodes) {
3101 			break;
3102 		}
3103 		trigger_syncer(pmp->mp);
3104 		tsleep(&pmp->inmem_dirty_chains, PINTERLOCKED, "h2memw", hz);
3105 #if 0
3106 		limit = pmp->mp->mnt_nvnodelistsize / 10;
3107 		if (limit < hammer2_limit_dirty_chains)
3108 			limit = hammer2_limit_dirty_chains;
3109 		if (limit < 1000)
3110 			limit = 1000;
3111 #endif
3112 	}
3113 }
3114 
3115 void
3116 hammer2_pfs_memory_inc(hammer2_pfs_t *pmp)
3117 {
3118 	if (pmp) {
3119 		atomic_add_int(&pmp->inmem_dirty_chains, 1);
3120 	}
3121 }
3122 
3123 void
3124 hammer2_pfs_memory_wakeup(hammer2_pfs_t *pmp)
3125 {
3126 	uint32_t waiting;
3127 
3128 	if (pmp) {
3129 		waiting = atomic_fetchadd_int(&pmp->inmem_dirty_chains, -1);
3130 		/* don't need --waiting to test flag */
3131 
3132 		if ((waiting & HAMMER2_DIRTYCHAIN_WAITING) &&
3133 		    (pmp->inmem_dirty_chains & HAMMER2_DIRTYCHAIN_MASK) <=
3134 		    hammer2_limit_dirty_chains * 2 / 3 &&
3135 		    pmp->sideq_count <= hammer2_limit_dirty_inodes * 2 / 3) {
3136 			atomic_clear_int(&pmp->inmem_dirty_chains,
3137 					 HAMMER2_DIRTYCHAIN_WAITING);
3138 			wakeup(&pmp->inmem_dirty_chains);
3139 		}
3140 	}
3141 }
3142 
3143 /*
3144  * Returns 0 if the filesystem has tons of free space
3145  * Returns 1 if the filesystem has less than 10% remaining
3146  * Returns 2 if the filesystem has less than 2%/5% (user/root) remaining.
3147  */
3148 int
3149 hammer2_vfs_enospace(hammer2_inode_t *ip, off_t bytes, struct ucred *cred)
3150 {
3151 	hammer2_pfs_t *pmp;
3152 	hammer2_dev_t *hmp;
3153 	hammer2_off_t free_reserved;
3154 	hammer2_off_t free_nominal;
3155 	int i;
3156 
3157 	pmp = ip->pmp;
3158 
3159 	if (pmp->free_ticks == 0 || pmp->free_ticks != ticks) {
3160 		free_reserved = HAMMER2_SEGSIZE;
3161 		free_nominal = 0x7FFFFFFFFFFFFFFFLLU;
3162 		for (i = 0; i < pmp->iroot->cluster.nchains; ++i) {
3163 			hmp = pmp->pfs_hmps[i];
3164 			if (hmp == NULL)
3165 				continue;
3166 			if (pmp->pfs_types[i] != HAMMER2_PFSTYPE_MASTER &&
3167 			    pmp->pfs_types[i] != HAMMER2_PFSTYPE_SOFT_MASTER)
3168 				continue;
3169 
3170 			if (free_nominal > hmp->voldata.allocator_free)
3171 				free_nominal = hmp->voldata.allocator_free;
3172 			if (free_reserved < hmp->free_reserved)
3173 				free_reserved = hmp->free_reserved;
3174 		}
3175 
3176 		/*
3177 		 * SMP races ok
3178 		 */
3179 		pmp->free_reserved = free_reserved;
3180 		pmp->free_nominal = free_nominal;
3181 		pmp->free_ticks = ticks;
3182 	} else {
3183 		free_reserved = pmp->free_reserved;
3184 		free_nominal = pmp->free_nominal;
3185 	}
3186 	if (cred && cred->cr_uid != 0) {
3187 		if ((int64_t)(free_nominal - bytes) <
3188 		    (int64_t)free_reserved) {
3189 			return 2;
3190 		}
3191 	} else {
3192 		if ((int64_t)(free_nominal - bytes) <
3193 		    (int64_t)free_reserved / 2) {
3194 			return 2;
3195 		}
3196 	}
3197 	if ((int64_t)(free_nominal - bytes) < (int64_t)free_reserved * 2)
3198 		return 1;
3199 	return 0;
3200 }
3201 
3202 /*
3203  * Debugging
3204  */
3205 void
3206 hammer2_dump_chain(hammer2_chain_t *chain, int tab, int *countp, char pfx,
3207 		   u_int flags)
3208 {
3209 	hammer2_chain_t *scan;
3210 	hammer2_chain_t *parent;
3211 
3212 	--*countp;
3213 	if (*countp == 0) {
3214 		kprintf("%*.*s...\n", tab, tab, "");
3215 		return;
3216 	}
3217 	if (*countp < 0)
3218 		return;
3219 	kprintf("%*.*s%c-chain %p.%d %016jx/%d mir=%016jx\n",
3220 		tab, tab, "", pfx,
3221 		chain, chain->bref.type,
3222 		chain->bref.key, chain->bref.keybits,
3223 		chain->bref.mirror_tid);
3224 
3225 	kprintf("%*.*s      [%08x] (%s) refs=%d",
3226 		tab, tab, "",
3227 		chain->flags,
3228 		((chain->bref.type == HAMMER2_BREF_TYPE_INODE &&
3229 		chain->data) ?  (char *)chain->data->ipdata.filename : "?"),
3230 		chain->refs);
3231 
3232 	parent = chain->parent;
3233 	if (parent)
3234 		kprintf("\n%*.*s      p=%p [pflags %08x prefs %d",
3235 			tab, tab, "",
3236 			parent, parent->flags, parent->refs);
3237 	if (RB_EMPTY(&chain->core.rbtree)) {
3238 		kprintf("\n");
3239 	} else {
3240 		kprintf(" {\n");
3241 		RB_FOREACH(scan, hammer2_chain_tree, &chain->core.rbtree) {
3242 			if ((scan->flags & flags) || flags == (u_int)-1) {
3243 				hammer2_dump_chain(scan, tab + 4, countp, 'a',
3244 						   flags);
3245 			}
3246 		}
3247 		if (chain->bref.type == HAMMER2_BREF_TYPE_INODE && chain->data)
3248 			kprintf("%*.*s}(%s)\n", tab, tab, "",
3249 				chain->data->ipdata.filename);
3250 		else
3251 			kprintf("%*.*s}\n", tab, tab, "");
3252 	}
3253 }
3254