1 /*
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 2022 Tomohiro Kusumi <tkusumi@netbsd.org>
5  * Copyright (c) 2011-2022 The DragonFly Project.  All rights reserved.
6  *
7  * This code is derived from software contributed to The DragonFly Project
8  * by Matthew Dillon <dillon@dragonflybsd.org>
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  *
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in
18  *    the documentation and/or other materials provided with the
19  *    distribution.
20  * 3. Neither the name of The DragonFly Project nor the names of its
21  *    contributors may be used to endorse or promote products derived
22  *    from this software without specific, prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
25  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
26  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
27  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
28  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
29  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
30  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
31  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
32  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
33  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
34  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35  * SUCH DAMAGE.
36  */
37 /*
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/kernel.h>
41 #include <sys/nlookup.h>
42 #include <sys/vnode.h>
43 #include <sys/mount.h>
44 #include <sys/fcntl.h>
45 #include <sys/vfsops.h>
46 #include <sys/sysctl.h>
47 #include <sys/socket.h>
48 #include <sys/objcache.h>
49 #include <sys/proc.h>
50 #include <sys/lock.h>
51 #include <sys/file.h>
52 */
53 
54 #include "hammer2.h"
55 
56 TAILQ_HEAD(hammer2_mntlist, hammer2_dev);
57 static struct hammer2_mntlist hammer2_mntlist;
58 
59 struct hammer2_pfslist hammer2_pfslist;
60 struct hammer2_pfslist hammer2_spmplist;
61 struct lock hammer2_mntlk;
62 
63 int hammer2_supported_version = HAMMER2_VOL_VERSION_DEFAULT;
64 int hammer2_debug;
65 int hammer2_aux_flags;
66 int hammer2_xop_nthreads;
67 int hammer2_xop_sgroups;
68 int hammer2_xop_xgroups;
69 int hammer2_xop_xbase;
70 int hammer2_xop_mod;
71 long hammer2_debug_inode;
72 int hammer2_cluster_meta_read = 1;	/* physical read-ahead */
73 int hammer2_cluster_data_read = 4;	/* physical read-ahead */
74 int hammer2_cluster_write = 0;		/* physical write clustering */
75 int hammer2_dedup_enable = 1;
76 int hammer2_always_compress = 0;	/* always try to compress */
77 int hammer2_flush_pipe = 100;
78 int hammer2_dio_count;
79 int hammer2_dio_limit = 256;
80 int hammer2_bulkfree_tps = 5000;
81 int hammer2_spread_workers;
82 int hammer2_limit_saved_depth;
83 long hammer2_chain_allocs;
84 long hammer2_limit_saved_chains;
85 long hammer2_limit_dirty_chains;
86 long hammer2_limit_dirty_inodes;
87 long hammer2_count_modified_chains;
88 long hammer2_iod_file_read;
89 long hammer2_iod_meta_read;
90 long hammer2_iod_indr_read;
91 long hammer2_iod_fmap_read;
92 long hammer2_iod_volu_read;
93 long hammer2_iod_file_write;
94 long hammer2_iod_file_wembed;
95 long hammer2_iod_file_wzero;
96 long hammer2_iod_file_wdedup;
97 long hammer2_iod_meta_write;
98 long hammer2_iod_indr_write;
99 long hammer2_iod_fmap_write;
100 long hammer2_iod_volu_write;
101 static long hammer2_iod_inode_creates;
102 static long hammer2_iod_inode_deletes;
103 
104 long hammer2_process_icrc32;
105 long hammer2_process_xxhash64;
106 
107 int hz;
108 int ticks;
109 int64_t vnode_count;
110 
111 MALLOC_DECLARE(M_HAMMER2_CBUFFER);
112 MALLOC_DEFINE(M_HAMMER2_CBUFFER, "HAMMER2-compbuffer",
113 		"Buffer used for compression.");
114 
115 MALLOC_DECLARE(M_HAMMER2_DEBUFFER);
116 MALLOC_DEFINE(M_HAMMER2_DEBUFFER, "HAMMER2-decompbuffer",
117 		"Buffer used for decompression.");
118 
119 SYSCTL_NODE(_vfs, OID_AUTO, hammer2, CTLFLAG_RW, 0, "HAMMER2 filesystem");
120 
121 SYSCTL_INT(_vfs_hammer2, OID_AUTO, supported_version, CTLFLAG_RD,
122 	   &hammer2_supported_version, 0, "");
123 SYSCTL_INT(_vfs_hammer2, OID_AUTO, aux_flags, CTLFLAG_RW,
124 	   &hammer2_aux_flags, 0, "");
125 SYSCTL_INT(_vfs_hammer2, OID_AUTO, debug, CTLFLAG_RW,
126 	   &hammer2_debug, 0, "");
127 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, debug_inode, CTLFLAG_RW,
128 	   &hammer2_debug_inode, 0, "");
129 SYSCTL_INT(_vfs_hammer2, OID_AUTO, spread_workers, CTLFLAG_RW,
130 	   &hammer2_spread_workers, 0, "");
131 SYSCTL_INT(_vfs_hammer2, OID_AUTO, cluster_meta_read, CTLFLAG_RW,
132 	   &hammer2_cluster_meta_read, 0, "");
133 SYSCTL_INT(_vfs_hammer2, OID_AUTO, cluster_data_read, CTLFLAG_RW,
134 	   &hammer2_cluster_data_read, 0, "");
135 SYSCTL_INT(_vfs_hammer2, OID_AUTO, cluster_write, CTLFLAG_RW,
136 	   &hammer2_cluster_write, 0, "");
137 SYSCTL_INT(_vfs_hammer2, OID_AUTO, dedup_enable, CTLFLAG_RW,
138 	   &hammer2_dedup_enable, 0, "");
139 SYSCTL_INT(_vfs_hammer2, OID_AUTO, always_compress, CTLFLAG_RW,
140 	   &hammer2_always_compress, 0, "");
141 SYSCTL_INT(_vfs_hammer2, OID_AUTO, flush_pipe, CTLFLAG_RW,
142 	   &hammer2_flush_pipe, 0, "");
143 SYSCTL_INT(_vfs_hammer2, OID_AUTO, bulkfree_tps, CTLFLAG_RW,
144 	   &hammer2_bulkfree_tps, 0, "");
145 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, chain_allocs, CTLFLAG_RD,
146 	   &hammer2_chain_allocs, 0, "");
147 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, limit_saved_chains, CTLFLAG_RW,
148 	   &hammer2_limit_saved_chains, 0, "");
149 SYSCTL_INT(_vfs_hammer2, OID_AUTO, limit_saved_depth, CTLFLAG_RW,
150 	   &hammer2_limit_saved_depth, 0, "");
151 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, limit_dirty_chains, CTLFLAG_RW,
152 	   &hammer2_limit_dirty_chains, 0, "");
153 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, limit_dirty_inodes, CTLFLAG_RW,
154 	   &hammer2_limit_dirty_inodes, 0, "");
155 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, count_modified_chains, CTLFLAG_RD,
156 	   &hammer2_count_modified_chains, 0, "");
157 SYSCTL_INT(_vfs_hammer2, OID_AUTO, dio_count, CTLFLAG_RD,
158 	   &hammer2_dio_count, 0, "");
159 SYSCTL_INT(_vfs_hammer2, OID_AUTO, dio_limit, CTLFLAG_RW,
160 	   &hammer2_dio_limit, 0, "");
161 
162 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_file_read, CTLFLAG_RD,
163 	   &hammer2_iod_file_read, 0, "");
164 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_meta_read, CTLFLAG_RD,
165 	   &hammer2_iod_meta_read, 0, "");
166 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_indr_read, CTLFLAG_RD,
167 	   &hammer2_iod_indr_read, 0, "");
168 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_fmap_read, CTLFLAG_RD,
169 	   &hammer2_iod_fmap_read, 0, "");
170 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_volu_read, CTLFLAG_RD,
171 	   &hammer2_iod_volu_read, 0, "");
172 
173 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_file_write, CTLFLAG_RD,
174 	   &hammer2_iod_file_write, 0, "");
175 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_file_wembed, CTLFLAG_RD,
176 	   &hammer2_iod_file_wembed, 0, "");
177 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_file_wzero, CTLFLAG_RD,
178 	   &hammer2_iod_file_wzero, 0, "");
179 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_file_wdedup, CTLFLAG_RD,
180 	   &hammer2_iod_file_wdedup, 0, "");
181 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_meta_write, CTLFLAG_RD,
182 	   &hammer2_iod_meta_write, 0, "");
183 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_indr_write, CTLFLAG_RD,
184 	   &hammer2_iod_indr_write, 0, "");
185 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_fmap_write, CTLFLAG_RD,
186 	   &hammer2_iod_fmap_write, 0, "");
187 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_volu_write, CTLFLAG_RD,
188 	   &hammer2_iod_volu_write, 0, "");
189 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_inode_creates, CTLFLAG_RD,
190 	   &hammer2_iod_inode_creates, 0, "");
191 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_inode_deletes, CTLFLAG_RD,
192 	   &hammer2_iod_inode_deletes, 0, "");
193 
194 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, process_icrc32, CTLFLAG_RD,
195 	   &hammer2_process_icrc32, 0, "");
196 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, process_xxhash64, CTLFLAG_RD,
197 	   &hammer2_process_xxhash64, 0, "");
198 
199 /*
200 static int hammer2_vfs_init(struct vfsconf *conf);
201 static int hammer2_vfs_uninit(struct vfsconf *vfsp);
202 static int hammer2_vfs_mount(struct mount *mp, char *path, caddr_t data,
203 				struct ucred *cred);
204 static int hammer2_remount(hammer2_dev_t *, struct mount *, char *,
205 				struct ucred *);
206 */
207 static int hammer2_recovery(hammer2_dev_t *hmp);
208 /*
209 static int hammer2_vfs_unmount(struct mount *mp, int mntflags);
210 static int hammer2_vfs_root(struct mount *mp, struct m_vnode **vpp);
211 */
212 static int hammer2_vfs_statfs(struct mount *mp, struct statfs *sbp,
213 				struct ucred *cred);
214 static int hammer2_vfs_statvfs(struct mount *mp, struct statvfs *sbp,
215 				struct ucred *cred);
216 /*
217 static int hammer2_vfs_fhtovp(struct mount *mp, struct m_vnode *rootvp,
218 				struct fid *fhp, struct m_vnode **vpp);
219 static int hammer2_vfs_vptofh(struct m_vnode *vp, struct fid *fhp);
220 static int hammer2_vfs_checkexp(struct mount *mp, struct sockaddr *nam,
221 				int *exflagsp, struct ucred **credanonp);
222 static int hammer2_vfs_modifying(struct mount *mp);
223 */
224 
225 static void hammer2_update_pmps(hammer2_dev_t *hmp);
226 
227 static void hammer2_mount_helper(struct mount *mp, hammer2_pfs_t *pmp);
228 static void hammer2_unmount_helper(struct mount *mp, hammer2_pfs_t *pmp,
229 				hammer2_dev_t *hmp);
230 static int hammer2_fixup_pfses(hammer2_dev_t *hmp);
231 
232 /*
233  * HAMMER2 vfs operations.
234  */
235 /*
236 static struct vfsops hammer2_vfsops = {
237 	.vfs_flags	= 0,
238 	.vfs_init	= hammer2_vfs_init,
239 	.vfs_uninit	= hammer2_vfs_uninit,
240 	.vfs_sync	= hammer2_vfs_sync,
241 	.vfs_mount	= hammer2_vfs_mount,
242 	.vfs_unmount	= hammer2_vfs_unmount,
243 	.vfs_root	= hammer2_vfs_root,
244 	.vfs_statfs	= hammer2_vfs_statfs,
245 	.vfs_statvfs	= hammer2_vfs_statvfs,
246 	.vfs_vget	= hammer2_vfs_vget,
247 	.vfs_vptofh	= hammer2_vfs_vptofh,
248 	.vfs_fhtovp	= hammer2_vfs_fhtovp,
249 	.vfs_checkexp	= hammer2_vfs_checkexp,
250 	.vfs_modifying	= hammer2_vfs_modifying
251 };
252 */
253 
254 MALLOC_DEFINE(M_HAMMER2, "HAMMER2-mount", "");
255 
256 VFS_SET(hammer2_vfsops, hammer2, VFCF_MPSAFE);
257 MODULE_VERSION(hammer2, 1);
258 
259 int
260 hammer2_vfs_init(void)
261 {
262 	/*
263 	static struct objcache_malloc_args margs_read;
264 	static struct objcache_malloc_args margs_write;
265 	static struct objcache_malloc_args margs_vop;
266 	*/
267 
268 	int error;
269 	int mod;
270 
271 	error = 0;
272 	kmalloc_raise_limit(M_HAMMER2, 0);	/* unlimited */
273 
274 	/*
275 	 * hammer2_xop_nthreads must be a multiple of ncpus,
276 	 * minimum 2 * ncpus.
277 	 */
278 	const int ncpus = 1;
279 	mod = ncpus;
280 	hammer2_xop_mod = mod;
281 	hammer2_xop_nthreads = mod * 2;
282 	/*
283 	while (hammer2_xop_nthreads / mod < HAMMER2_XOPGROUPS_MIN ||
284 	       hammer2_xop_nthreads < HAMMER2_XOPTHREADS_MIN)
285 	{
286 		hammer2_xop_nthreads += mod;
287 	}
288 	hammer2_xop_sgroups = hammer2_xop_nthreads / mod / 2;
289 	hammer2_xop_xgroups = hammer2_xop_nthreads / mod - hammer2_xop_sgroups;
290 	hammer2_xop_xbase = hammer2_xop_sgroups * mod;
291 	*/
292 
293 	/*
294 	 * A large DIO cache is needed to retain dedup enablement masks.
295 	 * The bulkfree code clears related masks as part of the disk block
296 	 * recycling algorithm, preventing it from being used for a later
297 	 * dedup.
298 	 *
299 	 * NOTE: A large buffer cache can actually interfere with dedup
300 	 *	 operation because we dedup based on media physical buffers
301 	 *	 and not logical buffers.  Try to make the DIO case large
302 	 *	 enough to avoid this problem, but also cap it.
303 	 */
304 	const long nbuf = 100000; /* XXX */
305 	hammer2_dio_limit = nbuf * 2;
306 	if (hammer2_dio_limit > 100000)
307 		hammer2_dio_limit = 100000;
308 
309 	if (HAMMER2_BLOCKREF_BYTES != sizeof(struct hammer2_blockref))
310 		error = EINVAL;
311 	if (HAMMER2_INODE_BYTES != sizeof(struct hammer2_inode_data))
312 		error = EINVAL;
313 	if (HAMMER2_VOLUME_BYTES != sizeof(struct hammer2_volume_data))
314 		error = EINVAL;
315 
316 	if (error) {
317 		kprintf("HAMMER2 structure size mismatch; cannot continue.\n");
318 		return (error);
319 	}
320 
321 #if 0
322 	margs_read.objsize = 65536;
323 	margs_read.mtype = M_HAMMER2_DEBUFFER;
324 
325 	margs_write.objsize = 32768;
326 	margs_write.mtype = M_HAMMER2_CBUFFER;
327 
328 	margs_vop.objsize = sizeof(hammer2_xop_t);
329 	margs_vop.mtype = M_HAMMER2;
330 
331 	/*
332 	 * Note thaht for the XOPS cache we want backing store allocations
333 	 * to use M_ZERO.  This is not allowed in objcache_get() (to avoid
334 	 * confusion), so use the backing store function that does it.  This
335 	 * means that initial XOPS objects are zerod but REUSED objects are
336 	 * not.  So we are responsible for cleaning the object up sufficiently
337 	 * for our needs before objcache_put()ing it back (typically just the
338 	 * FIFO indices).
339 	 */
340 	cache_buffer_read = objcache_create(margs_read.mtype->ks_shortdesc,
341 				0, 1, NULL, NULL, NULL,
342 				objcache_malloc_alloc,
343 				objcache_malloc_free,
344 				&margs_read);
345 	cache_buffer_write = objcache_create(margs_write.mtype->ks_shortdesc,
346 				0, 1, NULL, NULL, NULL,
347 				objcache_malloc_alloc,
348 				objcache_malloc_free,
349 				&margs_write);
350 	cache_xops = objcache_create(margs_vop.mtype->ks_shortdesc,
351 				0, 1, NULL, NULL, NULL,
352 				objcache_malloc_alloc_zero,
353 				objcache_malloc_free,
354 				&margs_vop);
355 #endif
356 
357 
358 	lockinit(&hammer2_mntlk, "mntlk", 0, 0);
359 	TAILQ_INIT(&hammer2_mntlist);
360 	TAILQ_INIT(&hammer2_pfslist);
361 	TAILQ_INIT(&hammer2_spmplist);
362 
363 	const int maxvnodes = 100000; /* XXX */
364 	hammer2_limit_dirty_chains = maxvnodes / 10;
365 	if (hammer2_limit_dirty_chains > HAMMER2_LIMIT_DIRTY_CHAINS)
366 		hammer2_limit_dirty_chains = HAMMER2_LIMIT_DIRTY_CHAINS;
367 	if (hammer2_limit_dirty_chains < 1000)
368 		hammer2_limit_dirty_chains = 1000;
369 
370 	hammer2_limit_dirty_inodes = maxvnodes / 25;
371 	if (hammer2_limit_dirty_inodes < 100)
372 		hammer2_limit_dirty_inodes = 100;
373 	if (hammer2_limit_dirty_inodes > HAMMER2_LIMIT_DIRTY_INODES)
374 		hammer2_limit_dirty_inodes = HAMMER2_LIMIT_DIRTY_INODES;
375 
376 	hammer2_limit_saved_chains = hammer2_limit_dirty_chains * 5;
377 
378 	return (error);
379 }
380 
381 int
382 hammer2_vfs_uninit(void)
383 {
384 	/*
385 	objcache_destroy(cache_buffer_read);
386 	objcache_destroy(cache_buffer_write);
387 	objcache_destroy(cache_xops);
388 	*/
389 	return 0;
390 }
391 
392 /*
393  * Core PFS allocator.  Used to allocate or reference the pmp structure
394  * for PFS cluster mounts and the spmp structure for media (hmp) structures.
395  * The pmp can be passed in or loaded by this function using the chain and
396  * inode data.
397  *
398  * pmp->modify_tid tracks new modify_tid transaction ids for front-end
399  * transactions.  Note that synchronization does not use this field.
400  * (typically frontend operations and synchronization cannot run on the
401  * same PFS node at the same time).
402  *
403  * XXX check locking
404  */
405 hammer2_pfs_t *
406 hammer2_pfsalloc(hammer2_chain_t *chain,
407 		 const hammer2_inode_data_t *ripdata,
408 		 hammer2_dev_t *force_local)
409 {
410 	hammer2_pfs_t *pmp;
411 	hammer2_inode_t *iroot;
412 	int count;
413 	int i;
414 	int j;
415 
416 	pmp = NULL;
417 
418 	/*
419 	 * Locate or create the PFS based on the cluster id.  If ripdata
420 	 * is NULL this is a spmp which is unique and is always allocated.
421 	 *
422 	 * If the device is mounted in local mode all PFSs are considered
423 	 * independent and not part of any cluster (for debugging only).
424 	 */
425 	if (ripdata) {
426 		TAILQ_FOREACH(pmp, &hammer2_pfslist, mntentry) {
427 			if (force_local != pmp->force_local)
428 				continue;
429 			if (force_local == NULL &&
430 			    bcmp(&pmp->pfs_clid, &ripdata->meta.pfs_clid,
431 				 sizeof(pmp->pfs_clid)) == 0) {
432 				break;
433 			} else if (force_local && pmp->pfs_names[0] &&
434 			    strcmp(pmp->pfs_names[0], (const char *)ripdata->filename) == 0) {
435 				break;
436 			}
437 		}
438 	}
439 
440 	if (pmp == NULL) {
441 		pmp = kmalloc(sizeof(*pmp), M_HAMMER2, M_WAITOK | M_ZERO);
442 		pmp->force_local = force_local;
443 		hammer2_trans_manage_init(pmp);
444 		kmalloc_create_obj(&pmp->minode, "HAMMER2-inodes",
445 				   sizeof(struct hammer2_inode));
446 		lockinit(&pmp->lock, "pfslk", 0, 0);
447 		hammer2_spin_init(&pmp->inum_spin, "hm2pfsalloc_inum");
448 		hammer2_spin_init(&pmp->xop_spin, "h2xop");
449 		hammer2_spin_init(&pmp->lru_spin, "h2lru");
450 		RB_INIT(&pmp->inum_tree);
451 		TAILQ_INIT(&pmp->syncq);
452 		TAILQ_INIT(&pmp->depq);
453 		TAILQ_INIT(&pmp->lru_list);
454 		hammer2_spin_init(&pmp->list_spin, "h2pfsalloc_list");
455 
456 		/*
457 		 * Save the last media transaction id for the flusher.  Set
458 		 * initial
459 		 */
460 		if (ripdata) {
461 			pmp->pfs_clid = ripdata->meta.pfs_clid;
462 			TAILQ_INSERT_TAIL(&hammer2_pfslist, pmp, mntentry);
463 		} else {
464 			pmp->flags |= HAMMER2_PMPF_SPMP;
465 			TAILQ_INSERT_TAIL(&hammer2_spmplist, pmp, mntentry);
466 		}
467 
468 		/*
469 		 * The synchronization thread may start too early, make
470 		 * sure it stays frozen until we are ready to let it go.
471 		 * XXX
472 		 */
473 		/*
474 		pmp->primary_thr.flags = HAMMER2_THREAD_FROZEN |
475 					 HAMMER2_THREAD_REMASTER;
476 		*/
477 	}
478 
479 	/*
480 	 * Create the PFS's root inode and any missing XOP helper threads.
481 	 */
482 	if ((iroot = pmp->iroot) == NULL) {
483 		iroot = hammer2_inode_get(pmp, NULL, 1, -1);
484 		if (ripdata)
485 			iroot->meta = ripdata->meta;
486 		pmp->iroot = iroot;
487 		hammer2_inode_ref(iroot);
488 		hammer2_inode_unlock(iroot);
489 	}
490 
491 	/*
492 	 * Stop here if no chain is passed in.
493 	 */
494 	if (chain == NULL)
495 		goto done;
496 
497 	/*
498 	 * When a chain is passed in we must add it to the PFS's root
499 	 * inode, update pmp->pfs_types[], and update the syncronization
500 	 * threads.
501 	 *
502 	 * When forcing local mode, mark the PFS as a MASTER regardless.
503 	 *
504 	 * At the moment empty spots can develop due to removals or failures.
505 	 * Ultimately we want to re-fill these spots but doing so might
506 	 * confused running code. XXX
507 	 */
508 	hammer2_inode_ref(iroot);
509 	hammer2_mtx_ex(&iroot->lock);
510 	j = iroot->cluster.nchains;
511 
512 	if (j == HAMMER2_MAXCLUSTER) {
513 		kprintf("hammer2_pfsalloc: cluster full!\n");
514 		/* XXX fatal error? */
515 	} else {
516 		KKASSERT(chain->pmp == NULL);
517 		chain->pmp = pmp;
518 		hammer2_chain_ref(chain);
519 		iroot->cluster.array[j].chain = chain;
520 		if (force_local)
521 			pmp->pfs_types[j] = HAMMER2_PFSTYPE_MASTER;
522 		else
523 			pmp->pfs_types[j] = ripdata->meta.pfs_type;
524 		pmp->pfs_names[j] = kstrdup((const char *)ripdata->filename, M_HAMMER2);
525 		pmp->pfs_hmps[j] = chain->hmp;
526 		hammer2_spin_ex(&pmp->inum_spin);
527 		pmp->pfs_iroot_blocksets[j] = chain->data->ipdata.u.blockset;
528 		hammer2_spin_unex(&pmp->inum_spin);
529 
530 		/*
531 		 * If the PFS is already mounted we must account
532 		 * for the mount_count here.
533 		 */
534 		if (pmp->mp)
535 			++chain->hmp->mount_count;
536 
537 		/*
538 		 * May have to fixup dirty chain tracking.  Previous
539 		 * pmp was NULL so nothing to undo.
540 		 */
541 		if (chain->flags & HAMMER2_CHAIN_MODIFIED)
542 			hammer2_pfs_memory_inc(pmp);
543 		++j;
544 	}
545 	iroot->cluster.nchains = j;
546 
547 	/*
548 	 * Update nmasters from any PFS inode which is part of the cluster.
549 	 * It is possible that this will result in a value which is too
550 	 * high.  MASTER PFSs are authoritative for pfs_nmasters and will
551 	 * override this value later on.
552 	 *
553 	 * (This informs us of masters that might not currently be
554 	 *  discoverable by this mount).
555 	 */
556 	if (ripdata && pmp->pfs_nmasters < ripdata->meta.pfs_nmasters) {
557 		pmp->pfs_nmasters = ripdata->meta.pfs_nmasters;
558 	}
559 
560 	/*
561 	 * Count visible masters.  Masters are usually added with
562 	 * ripdata->meta.pfs_nmasters set to 1.  This detects when there
563 	 * are more (XXX and must update the master inodes).
564 	 */
565 	count = 0;
566 	for (i = 0; i < iroot->cluster.nchains; ++i) {
567 		if (pmp->pfs_types[i] == HAMMER2_PFSTYPE_MASTER)
568 			++count;
569 	}
570 	if (pmp->pfs_nmasters < count)
571 		pmp->pfs_nmasters = count;
572 
573 	/*
574 	 * Create missing synchronization and support threads.
575 	 *
576 	 * Single-node masters (including snapshots) have nothing to
577 	 * synchronize and do not require this thread.
578 	 *
579 	 * Multi-node masters or any number of soft masters, slaves, copy,
580 	 * or other PFS types need the thread.
581 	 *
582 	 * Each thread is responsible for its particular cluster index.
583 	 * We use independent threads so stalls or mismatches related to
584 	 * any given target do not affect other targets.
585 	 */
586 	for (i = 0; i < iroot->cluster.nchains; ++i) {
587 		/*
588 		 * Single-node masters (including snapshots) have nothing
589 		 * to synchronize and will make direct xops support calls,
590 		 * thus they do not require this thread.
591 		 *
592 		 * Note that there can be thousands of snapshots.  We do not
593 		 * want to create thousands of threads.
594 		 */
595 		if (pmp->pfs_nmasters <= 1 &&
596 		    pmp->pfs_types[i] == HAMMER2_PFSTYPE_MASTER) {
597 			continue;
598 		}
599 
600 		/*
601 		 * Sync support thread
602 		 */
603 		/*
604 		if (pmp->sync_thrs[i].td == NULL) {
605 			hammer2_thr_create(&pmp->sync_thrs[i], pmp, NULL,
606 					   "h2nod", i, -1,
607 					   hammer2_primary_sync_thread);
608 		}
609 		*/
610 	}
611 
612 	/*
613 	 * Create missing Xop threads
614 	 *
615 	 * NOTE: We create helper threads for all mounted PFSs or any
616 	 *	 PFSs with 2+ nodes (so the sync thread can update them,
617 	 *	 even if not mounted).
618 	 */
619 	if (pmp->mp || iroot->cluster.nchains >= 2)
620 		hammer2_xop_helper_create(pmp);
621 
622 	hammer2_mtx_unlock(&iroot->lock);
623 	hammer2_inode_drop(iroot);
624 done:
625 	return pmp;
626 }
627 
628 /*
629  * Deallocate an element of a probed PFS.  If destroying and this is a
630  * MASTER, adjust nmasters.
631  *
632  * This function does not physically destroy the PFS element in its device
633  * under the super-root  (see hammer2_ioctl_pfs_delete()).
634  */
635 void
636 hammer2_pfsdealloc(hammer2_pfs_t *pmp, int clindex, int destroying)
637 {
638 	hammer2_inode_t *iroot;
639 	hammer2_chain_t *chain;
640 	int j;
641 
642 	/*
643 	 * Cleanup our reference on iroot.  iroot is (should) not be needed
644 	 * by the flush code.
645 	 */
646 	iroot = pmp->iroot;
647 	if (iroot) {
648 		/*
649 		 * Stop synchronizing
650 		 *
651 		 * XXX flush after acquiring the iroot lock.
652 		 * XXX clean out the cluster index from all inode structures.
653 		 */
654 		hammer2_thr_delete(&pmp->sync_thrs[clindex]);
655 
656 		/*
657 		 * Remove the cluster index from the group.  If destroying
658 		 * the PFS and this is a master, adjust pfs_nmasters.
659 		 */
660 		hammer2_mtx_ex(&iroot->lock);
661 		chain = iroot->cluster.array[clindex].chain;
662 		iroot->cluster.array[clindex].chain = NULL;
663 
664 		switch(pmp->pfs_types[clindex]) {
665 		case HAMMER2_PFSTYPE_MASTER:
666 			if (destroying && pmp->pfs_nmasters > 0)
667 				--pmp->pfs_nmasters;
668 			/* XXX adjust ripdata->meta.pfs_nmasters */
669 			break;
670 		default:
671 			break;
672 		}
673 		pmp->pfs_types[clindex] = HAMMER2_PFSTYPE_NONE;
674 
675 		hammer2_mtx_unlock(&iroot->lock);
676 
677 		/*
678 		 * Release the chain.
679 		 */
680 		if (chain) {
681 			atomic_set_int(&chain->flags, HAMMER2_CHAIN_RELEASE);
682 			hammer2_chain_drop(chain);
683 		}
684 
685 		/*
686 		 * Terminate all XOP threads for the cluster index.
687 		 */
688 		if (pmp->xop_groups) {
689 			for (j = 0; j < hammer2_xop_nthreads; ++j) {
690 				hammer2_thr_delete(
691 					&pmp->xop_groups[j].thrs[clindex]);
692 			}
693 		}
694 	}
695 }
696 
697 /*
698  * Destroy a PFS, typically only occurs after the last mount on a device
699  * has gone away.
700  */
701 static void
702 hammer2_pfsfree(hammer2_pfs_t *pmp)
703 {
704 	hammer2_inode_t *iroot;
705 	hammer2_chain_t *chain;
706 	int chains_still_present = 0;
707 	int i;
708 	//int j;
709 
710 	/*
711 	 * Cleanup our reference on iroot.  iroot is (should) not be needed
712 	 * by the flush code.
713 	 */
714 	if (pmp->flags & HAMMER2_PMPF_SPMP)
715 		TAILQ_REMOVE(&hammer2_spmplist, pmp, mntentry);
716 	else
717 		TAILQ_REMOVE(&hammer2_pfslist, pmp, mntentry);
718 
719 	/*
720 	 * Cleanup chains remaining on LRU list.
721 	 */
722 	hammer2_spin_ex(&pmp->lru_spin);
723 	while ((chain = TAILQ_FIRST(&pmp->lru_list)) != NULL) {
724 		KKASSERT(chain->flags & HAMMER2_CHAIN_ONLRU);
725 		atomic_add_int(&pmp->lru_count, -1);
726 		atomic_clear_int(&chain->flags, HAMMER2_CHAIN_ONLRU);
727 		TAILQ_REMOVE(&pmp->lru_list, chain, lru_node);
728 		hammer2_chain_ref(chain);
729 		hammer2_spin_unex(&pmp->lru_spin);
730 		atomic_set_int(&chain->flags, HAMMER2_CHAIN_RELEASE);
731 		hammer2_chain_drop(chain);
732 		hammer2_spin_ex(&pmp->lru_spin);
733 	}
734 	hammer2_spin_unex(&pmp->lru_spin);
735 
736 	/*
737 	 * Clean up iroot
738 	 */
739 	iroot = pmp->iroot;
740 	if (iroot) {
741 		for (i = 0; i < iroot->cluster.nchains; ++i) {
742 			/*
743 			hammer2_thr_delete(&pmp->sync_thrs[i]);
744 			if (pmp->xop_groups) {
745 				for (j = 0; j < hammer2_xop_nthreads; ++j)
746 					hammer2_thr_delete(
747 						&pmp->xop_groups[j].thrs[i]);
748 			}
749 			*/
750 			chain = iroot->cluster.array[i].chain;
751 			if (chain && !RB_EMPTY(&chain->core.rbtree)) {
752 				kprintf("hammer2: Warning pmp %p still "
753 					"has active chains\n", pmp);
754 				chains_still_present = 1;
755 			}
756 		}
757 		KASSERT(iroot->refs == 1,
758 			("PMP->IROOT %p REFS WRONG %d", iroot, iroot->refs));
759 
760 		/* ref for iroot */
761 		hammer2_inode_drop(iroot);
762 		pmp->iroot = NULL;
763 	}
764 
765 	/*
766 	 * Free remaining pmp resources
767 	 */
768 	if (chains_still_present) {
769 		kprintf("hammer2: cannot free pmp %p, still in use\n", pmp);
770 	} else {
771 		/*
772 		 * In makefs HAMMER2, all inodes must be gone at this point.
773 		 * XXX vnode_count may not be 0 at this point.
774 		 */
775 		assert(hammer2_pfs_inode_count(pmp) == 0);
776 
777 		kmalloc_destroy_obj(&pmp->minode);
778 		kfree(pmp, M_HAMMER2);
779 	}
780 }
781 
782 /*
783  * Remove all references to hmp from the pfs list.  Any PFS which becomes
784  * empty is terminated and freed.
785  *
786  * XXX inefficient.
787  */
788 static void
789 hammer2_pfsfree_scan(hammer2_dev_t *hmp, int which)
790 {
791 	hammer2_pfs_t *pmp;
792 	hammer2_inode_t *iroot;
793 	hammer2_chain_t *rchain;
794 	int i;
795 	//int j;
796 	struct hammer2_pfslist *wlist;
797 
798 	if (which == 0)
799 		wlist = &hammer2_pfslist;
800 	else
801 		wlist = &hammer2_spmplist;
802 again:
803 	TAILQ_FOREACH(pmp, wlist, mntentry) {
804 		if ((iroot = pmp->iroot) == NULL)
805 			continue;
806 
807 		/*
808 		 * Determine if this PFS is affected.  If it is we must
809 		 * freeze all management threads and lock its iroot.
810 		 *
811 		 * Freezing a management thread forces it idle, operations
812 		 * in-progress will be aborted and it will have to start
813 		 * over again when unfrozen, or exit if told to exit.
814 		 */
815 		for (i = 0; i < HAMMER2_MAXCLUSTER; ++i) {
816 			if (pmp->pfs_hmps[i] == hmp)
817 				break;
818 		}
819 		if (i == HAMMER2_MAXCLUSTER)
820 			continue;
821 
822 		hammer2_vfs_sync_pmp(pmp, MNT_WAIT);
823 
824 		/*
825 		 * Make sure all synchronization threads are locked
826 		 * down.
827 		 */
828 		/*
829 		for (i = 0; i < HAMMER2_MAXCLUSTER; ++i) {
830 			if (pmp->pfs_hmps[i] == NULL)
831 				continue;
832 			hammer2_thr_freeze_async(&pmp->sync_thrs[i]);
833 			if (pmp->xop_groups) {
834 				for (j = 0; j < hammer2_xop_nthreads; ++j) {
835 					hammer2_thr_freeze_async(
836 						&pmp->xop_groups[j].thrs[i]);
837 				}
838 			}
839 		}
840 		for (i = 0; i < HAMMER2_MAXCLUSTER; ++i) {
841 			if (pmp->pfs_hmps[i] == NULL)
842 				continue;
843 			hammer2_thr_freeze(&pmp->sync_thrs[i]);
844 			if (pmp->xop_groups) {
845 				for (j = 0; j < hammer2_xop_nthreads; ++j) {
846 					hammer2_thr_freeze(
847 						&pmp->xop_groups[j].thrs[i]);
848 				}
849 			}
850 		}
851 		*/
852 
853 		/*
854 		 * Lock the inode and clean out matching chains.
855 		 * Note that we cannot use hammer2_inode_lock_*()
856 		 * here because that would attempt to validate the
857 		 * cluster that we are in the middle of ripping
858 		 * apart.
859 		 *
860 		 * WARNING! We are working directly on the inodes
861 		 *	    embedded cluster.
862 		 */
863 		hammer2_mtx_ex(&iroot->lock);
864 
865 		/*
866 		 * Remove the chain from matching elements of the PFS.
867 		 */
868 		for (i = 0; i < HAMMER2_MAXCLUSTER; ++i) {
869 			if (pmp->pfs_hmps[i] != hmp)
870 				continue;
871 			/*
872 			hammer2_thr_delete(&pmp->sync_thrs[i]);
873 			if (pmp->xop_groups) {
874 				for (j = 0; j < hammer2_xop_nthreads; ++j) {
875 					hammer2_thr_delete(
876 						&pmp->xop_groups[j].thrs[i]);
877 				}
878 			}
879 			*/
880 			rchain = iroot->cluster.array[i].chain;
881 			iroot->cluster.array[i].chain = NULL;
882 			pmp->pfs_types[i] = HAMMER2_PFSTYPE_NONE;
883 			if (pmp->pfs_names[i]) {
884 				kfree(pmp->pfs_names[i], M_HAMMER2);
885 				pmp->pfs_names[i] = NULL;
886 			}
887 			if (rchain) {
888 				hammer2_chain_drop(rchain);
889 				/* focus hint */
890 				if (iroot->cluster.focus == rchain)
891 					iroot->cluster.focus = NULL;
892 			}
893 			pmp->pfs_hmps[i] = NULL;
894 		}
895 		hammer2_mtx_unlock(&iroot->lock);
896 
897 		/*
898 		 * Cleanup trailing chains.  Gaps may remain.
899 		 */
900 		for (i = HAMMER2_MAXCLUSTER - 1; i >= 0; --i) {
901 			if (pmp->pfs_hmps[i])
902 				break;
903 		}
904 		iroot->cluster.nchains = i + 1;
905 
906 		/*
907 		 * If the PMP has no elements remaining we can destroy it.
908 		 * (this will transition management threads from frozen->exit).
909 		 */
910 		if (iroot->cluster.nchains == 0) {
911 			/*
912 			 * If this was the hmp's spmp, we need to clean
913 			 * a little more stuff out.
914 			 */
915 			if (hmp->spmp == pmp) {
916 				hmp->spmp = NULL;
917 				hmp->vchain.pmp = NULL;
918 				hmp->fchain.pmp = NULL;
919 			}
920 
921 			/*
922 			 * Free the pmp and restart the loop
923 			 */
924 			KKASSERT(TAILQ_EMPTY(&pmp->syncq));
925 			KKASSERT(TAILQ_EMPTY(&pmp->depq));
926 			hammer2_pfsfree(pmp);
927 			goto again;
928 		}
929 
930 		/*
931 		 * If elements still remain we need to set the REMASTER
932 		 * flag and unfreeze it.
933 		 */
934 		for (i = 0; i < HAMMER2_MAXCLUSTER; ++i) {
935 			if (pmp->pfs_hmps[i] == NULL)
936 				continue;
937 			/*
938 			hammer2_thr_remaster(&pmp->sync_thrs[i]);
939 			hammer2_thr_unfreeze(&pmp->sync_thrs[i]);
940 			if (pmp->xop_groups) {
941 				for (j = 0; j < hammer2_xop_nthreads; ++j) {
942 					hammer2_thr_remaster(
943 						&pmp->xop_groups[j].thrs[i]);
944 					hammer2_thr_unfreeze(
945 						&pmp->xop_groups[j].thrs[i]);
946 				}
947 			}
948 			*/
949 		}
950 	}
951 }
952 
953 /*
954  * Mount or remount HAMMER2 fileystem from physical media
955  *
956  *	mountroot
957  *		mp		mount point structure
958  *		path		NULL
959  *		data		<unused>
960  *		cred		<unused>
961  *
962  *	mount
963  *		mp		mount point structure
964  *		path		path to mount point
965  *		data		pointer to argument structure in user space
966  *			volume	volume path (device@LABEL form)
967  *			hflags	user mount flags
968  *		cred		user credentials
969  *
970  * RETURNS:	0	Success
971  *		!0	error number
972  */
973 int
974 hammer2_vfs_mount(struct m_vnode *makefs_devvp, struct mount *mp,
975 		  const char *label, const struct hammer2_mount_info *mi)
976 {
977 	struct hammer2_mount_info info = *mi;
978 	hammer2_pfs_t *pmp;
979 	hammer2_pfs_t *spmp;
980 	hammer2_dev_t *hmp, *hmp_tmp;
981 	hammer2_dev_t *force_local;
982 	hammer2_key_t key_next;
983 	hammer2_key_t key_dummy;
984 	hammer2_key_t lhc;
985 	hammer2_chain_t *parent;
986 	hammer2_chain_t *chain;
987 	const hammer2_inode_data_t *ripdata;
988 	hammer2_devvp_list_t devvpl;
989 	hammer2_devvp_t *e, *e_tmp;
990 	char *devstr;
991 	int ronly = ((mp->mnt_flag & MNT_RDONLY) != 0);
992 	int error;
993 	int i;
994 
995 	hmp = NULL;
996 	pmp = NULL;
997 	devstr = NULL;
998 
999 	kprintf("hammer2_mount: device=\"%s\" label=\"%s\" rdonly=%d\n",
1000 		devstr, label, ronly);
1001 
1002 	/*
1003 	 * Initialize all device vnodes.
1004 	 */
1005 	TAILQ_INIT(&devvpl);
1006 	error = hammer2_init_devvp(makefs_devvp, &devvpl);
1007 	if (error) {
1008 		kprintf("hammer2: failed to initialize devvp in %s\n", devstr);
1009 		hammer2_cleanup_devvp(&devvpl);
1010 		return error;
1011 	}
1012 
1013 	/*
1014 	 * Determine if the device has already been mounted.  After this
1015 	 * check hmp will be non-NULL if we are doing the second or more
1016 	 * hammer2 mounts from the same device.
1017 	 */
1018 	lockmgr(&hammer2_mntlk, LK_EXCLUSIVE);
1019 	if (!TAILQ_EMPTY(&devvpl)) {
1020 		/*
1021 		 * Match the device.  Due to the way devfs works,
1022 		 * we may not be able to directly match the vnode pointer,
1023 		 * so also check to see if the underlying device matches.
1024 		 */
1025 		TAILQ_FOREACH(hmp_tmp, &hammer2_mntlist, mntentry) {
1026 			TAILQ_FOREACH(e_tmp, &hmp_tmp->devvpl, entry) {
1027 				int devvp_found = 0;
1028 				TAILQ_FOREACH(e, &devvpl, entry) {
1029 					KKASSERT(e->devvp);
1030 					if (e_tmp->devvp == e->devvp)
1031 						devvp_found = 1;
1032 					/*
1033 					if (e_tmp->devvp->v_rdev &&
1034 					    e_tmp->devvp->v_rdev == e->devvp->v_rdev)
1035 						devvp_found = 1;
1036 					*/
1037 				}
1038 				if (!devvp_found)
1039 					goto next_hmp;
1040 			}
1041 			hmp = hmp_tmp;
1042 			kprintf("hammer2_mount: hmp=%p matched\n", hmp);
1043 			break;
1044 next_hmp:
1045 			continue;
1046 		}
1047 
1048 		/*
1049 		 * If no match this may be a fresh H2 mount, make sure
1050 		 * the device is not mounted on anything else.
1051 		 */
1052 		if (hmp == NULL) {
1053 			TAILQ_FOREACH(e, &devvpl, entry) {
1054 				struct m_vnode *devvp = e->devvp;
1055 				KKASSERT(devvp);
1056 				error = vfs_mountedon(devvp);
1057 				if (error) {
1058 					kprintf("hammer2_mount: %s mounted %d\n",
1059 						e->path, error);
1060 					hammer2_cleanup_devvp(&devvpl);
1061 					lockmgr(&hammer2_mntlk, LK_RELEASE);
1062 					return error;
1063 				}
1064 			}
1065 		}
1066 	} else {
1067 		/*
1068 		 * Match the label to a pmp already probed.
1069 		 */
1070 		TAILQ_FOREACH(pmp, &hammer2_pfslist, mntentry) {
1071 			for (i = 0; i < HAMMER2_MAXCLUSTER; ++i) {
1072 				if (pmp->pfs_names[i] &&
1073 				    strcmp(pmp->pfs_names[i], label) == 0) {
1074 					hmp = pmp->pfs_hmps[i];
1075 					break;
1076 				}
1077 			}
1078 			if (hmp)
1079 				break;
1080 		}
1081 		if (hmp == NULL) {
1082 			kprintf("hammer2_mount: PFS label \"%s\" not found\n",
1083 				label);
1084 			hammer2_cleanup_devvp(&devvpl);
1085 			lockmgr(&hammer2_mntlk, LK_RELEASE);
1086 			return ENOENT;
1087 		}
1088 	}
1089 
1090 	/*
1091 	 * Open the device if this isn't a secondary mount and construct
1092 	 * the H2 device mount (hmp).
1093 	 */
1094 	if (hmp == NULL) {
1095 		hammer2_chain_t *schain;
1096 		hammer2_xop_head_t xop;
1097 
1098 		/*
1099 		 * Now open the device
1100 		 */
1101 		KKASSERT(!TAILQ_EMPTY(&devvpl));
1102 		error = hammer2_open_devvp(&devvpl, ronly);
1103 		if (error) {
1104 			hammer2_close_devvp(&devvpl, ronly);
1105 			hammer2_cleanup_devvp(&devvpl);
1106 			lockmgr(&hammer2_mntlk, LK_RELEASE);
1107 			return error;
1108 		}
1109 
1110 		/*
1111 		 * Construct volumes and link with device vnodes.
1112 		 */
1113 		hmp = kmalloc(sizeof(*hmp), M_HAMMER2, M_WAITOK | M_ZERO);
1114 		hmp->devvp = NULL;
1115 		error = hammer2_init_vfsvolumes(mp, &devvpl, hmp->volumes,
1116 					     &hmp->voldata, &hmp->volhdrno,
1117 					     &hmp->devvp);
1118 		if (error) {
1119 			hammer2_close_devvp(&devvpl, ronly);
1120 			hammer2_cleanup_devvp(&devvpl);
1121 			lockmgr(&hammer2_mntlk, LK_RELEASE);
1122 			kfree(hmp, M_HAMMER2);
1123 			return error;
1124 		}
1125 		if (!hmp->devvp) {
1126 			kprintf("hammer2: failed to initialize root volume\n");
1127 			hammer2_unmount_helper(mp, NULL, hmp);
1128 			lockmgr(&hammer2_mntlk, LK_RELEASE);
1129 			hammer2_vfs_unmount(mp, MNT_FORCE);
1130 			return EINVAL;
1131 		}
1132 
1133 		ksnprintf(hmp->devrepname, sizeof(hmp->devrepname), "%s", devstr);
1134 		hmp->ronly = ronly;
1135 		hmp->hflags = info.hflags & HMNT2_DEVFLAGS;
1136 		kmalloc_create_obj(&hmp->mchain, "HAMMER2-chains",
1137 				   sizeof(struct hammer2_chain));
1138 		kmalloc_create_obj(&hmp->mio, "HAMMER2-dio",
1139 				   sizeof(struct hammer2_io));
1140 		kmalloc_create(&hmp->mmsg, "HAMMER2-msg");
1141 		TAILQ_INSERT_TAIL(&hammer2_mntlist, hmp, mntentry);
1142 		RB_INIT(&hmp->iotree);
1143 		hammer2_spin_init(&hmp->io_spin, "h2mount_io");
1144 		hammer2_spin_init(&hmp->list_spin, "h2mount_list");
1145 
1146 		lockinit(&hmp->vollk, "h2vol", 0, 0);
1147 		lockinit(&hmp->bulklk, "h2bulk", 0, 0);
1148 		lockinit(&hmp->bflock, "h2bflk", 0, 0);
1149 
1150 		/*
1151 		 * vchain setup. vchain.data is embedded.
1152 		 * vchain.refs is initialized and will never drop to 0.
1153 		 */
1154 		hmp->vchain.hmp = hmp;
1155 		hmp->vchain.refs = 1;
1156 		hmp->vchain.data = (void *)&hmp->voldata;
1157 		hmp->vchain.bref.type = HAMMER2_BREF_TYPE_VOLUME;
1158 		hmp->vchain.bref.data_off = 0 | HAMMER2_PBUFRADIX;
1159 		hmp->vchain.bref.mirror_tid = hmp->voldata.mirror_tid;
1160 		hammer2_chain_init(&hmp->vchain);
1161 
1162 		/*
1163 		 * fchain setup.  fchain.data is embedded.
1164 		 * fchain.refs is initialized and will never drop to 0.
1165 		 *
1166 		 * The data is not used but needs to be initialized to
1167 		 * pass assertion muster.  We use this chain primarily
1168 		 * as a placeholder for the freemap's top-level radix tree
1169 		 * so it does not interfere with the volume's topology
1170 		 * radix tree.
1171 		 */
1172 		hmp->fchain.hmp = hmp;
1173 		hmp->fchain.refs = 1;
1174 		hmp->fchain.data = (void *)&hmp->voldata.freemap_blockset;
1175 		hmp->fchain.bref.type = HAMMER2_BREF_TYPE_FREEMAP;
1176 		hmp->fchain.bref.data_off = 0 | HAMMER2_PBUFRADIX;
1177 		hmp->fchain.bref.mirror_tid = hmp->voldata.freemap_tid;
1178 		hmp->fchain.bref.methods =
1179 			HAMMER2_ENC_CHECK(HAMMER2_CHECK_FREEMAP) |
1180 			HAMMER2_ENC_COMP(HAMMER2_COMP_NONE);
1181 		hammer2_chain_init(&hmp->fchain);
1182 
1183 		/*
1184 		 * Initialize volume header related fields.
1185 		 */
1186 		KKASSERT(hmp->voldata.magic == HAMMER2_VOLUME_ID_HBO ||
1187 			 hmp->voldata.magic == HAMMER2_VOLUME_ID_ABO);
1188 		hmp->volsync = hmp->voldata;
1189 		hmp->free_reserved = hmp->voldata.allocator_size / 20;
1190 		/*
1191 		 * Must use hmp instead of volume header for these two
1192 		 * in order to handle volume versions transparently.
1193 		 */
1194 		if (hmp->voldata.version >= HAMMER2_VOL_VERSION_MULTI_VOLUMES) {
1195 			hmp->nvolumes = hmp->voldata.nvolumes;
1196 			hmp->total_size = hmp->voldata.total_size;
1197 		} else {
1198 			hmp->nvolumes = 1;
1199 			hmp->total_size = hmp->voldata.volu_size;
1200 		}
1201 		KKASSERT(hmp->nvolumes > 0);
1202 
1203 		/*
1204 		 * Move devvpl entries to hmp.
1205 		 */
1206 		TAILQ_INIT(&hmp->devvpl);
1207 		while ((e = TAILQ_FIRST(&devvpl)) != NULL) {
1208 			TAILQ_REMOVE(&devvpl, e, entry);
1209 			TAILQ_INSERT_TAIL(&hmp->devvpl, e, entry);
1210 		}
1211 		KKASSERT(TAILQ_EMPTY(&devvpl));
1212 		KKASSERT(!TAILQ_EMPTY(&hmp->devvpl));
1213 
1214 		/*
1215 		 * Really important to get these right or the flush and
1216 		 * teardown code will get confused.
1217 		 */
1218 		hmp->spmp = hammer2_pfsalloc(NULL, NULL, NULL);
1219 		spmp = hmp->spmp;
1220 		spmp->pfs_hmps[0] = hmp;
1221 
1222 		/*
1223 		 * Dummy-up vchain and fchain's modify_tid.  mirror_tid
1224 		 * is inherited from the volume header.
1225 		 */
1226 		hmp->vchain.bref.mirror_tid = hmp->voldata.mirror_tid;
1227 		hmp->vchain.bref.modify_tid = hmp->vchain.bref.mirror_tid;
1228 		hmp->vchain.pmp = spmp;
1229 		hmp->fchain.bref.mirror_tid = hmp->voldata.freemap_tid;
1230 		hmp->fchain.bref.modify_tid = hmp->fchain.bref.mirror_tid;
1231 		hmp->fchain.pmp = spmp;
1232 
1233 		/*
1234 		 * First locate the super-root inode, which is key 0
1235 		 * relative to the volume header's blockset.
1236 		 *
1237 		 * Then locate the root inode by scanning the directory keyspace
1238 		 * represented by the label.
1239 		 */
1240 		parent = hammer2_chain_lookup_init(&hmp->vchain, 0);
1241 		schain = hammer2_chain_lookup(&parent, &key_dummy,
1242 				      HAMMER2_SROOT_KEY, HAMMER2_SROOT_KEY,
1243 				      &error, 0);
1244 		hammer2_chain_lookup_done(parent);
1245 		if (schain == NULL) {
1246 			kprintf("hammer2_mount: invalid super-root\n");
1247 			hammer2_unmount_helper(mp, NULL, hmp);
1248 			lockmgr(&hammer2_mntlk, LK_RELEASE);
1249 			hammer2_vfs_unmount(mp, MNT_FORCE);
1250 			return EINVAL;
1251 		}
1252 		if (schain->error) {
1253 			kprintf("hammer2_mount: error %s reading super-root\n",
1254 				hammer2_error_str(schain->error));
1255 			hammer2_chain_unlock(schain);
1256 			hammer2_chain_drop(schain);
1257 			schain = NULL;
1258 			hammer2_unmount_helper(mp, NULL, hmp);
1259 			lockmgr(&hammer2_mntlk, LK_RELEASE);
1260 			hammer2_vfs_unmount(mp, MNT_FORCE);
1261 			return EINVAL;
1262 		}
1263 
1264 		/*
1265 		 * The super-root always uses an inode_tid of 1 when
1266 		 * creating PFSs.
1267 		 */
1268 		spmp->inode_tid = 1;
1269 		spmp->modify_tid = schain->bref.modify_tid + 1;
1270 
1271 		/*
1272 		 * Sanity-check schain's pmp and finish initialization.
1273 		 * Any chain belonging to the super-root topology should
1274 		 * have a NULL pmp (not even set to spmp).
1275 		 */
1276 		ripdata = &schain->data->ipdata;
1277 		KKASSERT(schain->pmp == NULL);
1278 		spmp->pfs_clid = ripdata->meta.pfs_clid;
1279 
1280 		/*
1281 		 * Replace the dummy spmp->iroot with a real one.  It's
1282 		 * easier to just do a wholesale replacement than to try
1283 		 * to update the chain and fixup the iroot fields.
1284 		 *
1285 		 * The returned inode is locked with the supplied cluster.
1286 		 */
1287 		hammer2_dummy_xop_from_chain(&xop, schain);
1288 		hammer2_inode_drop(spmp->iroot);
1289 		spmp->iroot = hammer2_inode_get(spmp, &xop, -1, -1);
1290 		spmp->spmp_hmp = hmp;
1291 		spmp->pfs_types[0] = ripdata->meta.pfs_type;
1292 		spmp->pfs_hmps[0] = hmp;
1293 		hammer2_inode_ref(spmp->iroot);
1294 		hammer2_inode_unlock(spmp->iroot);
1295 		hammer2_cluster_unlock(&xop.cluster);
1296 		hammer2_chain_drop(schain);
1297 		/* do not call hammer2_cluster_drop() on an embedded cluster */
1298 		schain = NULL;	/* now invalid */
1299 		/* leave spmp->iroot with one ref */
1300 
1301 		if (!hmp->ronly) {
1302 			error = hammer2_recovery(hmp);
1303 			if (error == 0)
1304 				error |= hammer2_fixup_pfses(hmp);
1305 			/* XXX do something with error */
1306 		}
1307 		hammer2_update_pmps(hmp);
1308 		hammer2_iocom_init(hmp);
1309 		hammer2_bulkfree_init(hmp);
1310 
1311 		/*
1312 		 * Ref the cluster management messaging descriptor.  The mount
1313 		 * program deals with the other end of the communications pipe.
1314 		 *
1315 		 * Root mounts typically do not supply one.
1316 		 */
1317 		/*
1318 		if (info.cluster_fd >= 0) {
1319 			fp = holdfp(curthread, info.cluster_fd, -1);
1320 			if (fp) {
1321 				hammer2_cluster_reconnect(hmp, fp);
1322 			} else {
1323 				kprintf("hammer2_mount: bad cluster_fd!\n");
1324 			}
1325 		}
1326 		*/
1327 	} else {
1328 		/* hmp->devvp_list is already constructed. */
1329 		hammer2_cleanup_devvp(&devvpl);
1330 		spmp = hmp->spmp;
1331 		if (info.hflags & HMNT2_DEVFLAGS) {
1332 			kprintf("hammer2_mount: Warning: mount flags pertaining "
1333 				"to the whole device may only be specified "
1334 				"on the first mount of the device: %08x\n",
1335 				info.hflags & HMNT2_DEVFLAGS);
1336 		}
1337 	}
1338 
1339 	/*
1340 	 * Force local mount (disassociate all PFSs from their clusters).
1341 	 * Used primarily for debugging.
1342 	 */
1343 	force_local = (hmp->hflags & HMNT2_LOCAL) ? hmp : NULL;
1344 
1345 	/*
1346 	 * Lookup the mount point under the media-localized super-root.
1347 	 * Scanning hammer2_pfslist doesn't help us because it represents
1348 	 * PFS cluster ids which can aggregate several named PFSs together.
1349 	 *
1350 	 * cluster->pmp will incorrectly point to spmp and must be fixed
1351 	 * up later on.
1352 	 */
1353 	hammer2_inode_lock(spmp->iroot, 0);
1354 	parent = hammer2_inode_chain(spmp->iroot, 0, HAMMER2_RESOLVE_ALWAYS);
1355 	lhc = hammer2_dirhash(label, strlen(label));
1356 	chain = hammer2_chain_lookup(&parent, &key_next,
1357 				     lhc, lhc + HAMMER2_DIRHASH_LOMASK,
1358 				     &error, 0);
1359 	while (chain) {
1360 		if (chain->bref.type == HAMMER2_BREF_TYPE_INODE &&
1361 		    strcmp(label, (char *)chain->data->ipdata.filename) == 0) {
1362 			break;
1363 		}
1364 		chain = hammer2_chain_next(&parent, chain, &key_next,
1365 					    key_next,
1366 					    lhc + HAMMER2_DIRHASH_LOMASK,
1367 					    &error, 0);
1368 	}
1369 	if (parent) {
1370 		hammer2_chain_unlock(parent);
1371 		hammer2_chain_drop(parent);
1372 	}
1373 	hammer2_inode_unlock(spmp->iroot);
1374 
1375 	/*
1376 	 * PFS could not be found?
1377 	 */
1378 	if (chain == NULL) {
1379 		hammer2_unmount_helper(mp, NULL, hmp);
1380 		lockmgr(&hammer2_mntlk, LK_RELEASE);
1381 		hammer2_vfs_unmount(mp, MNT_FORCE);
1382 
1383 		if (error) {
1384 			kprintf("hammer2_mount: PFS label I/O error\n");
1385 			return EINVAL;
1386 		} else {
1387 			kprintf("hammer2_mount: PFS label \"%s\" not found\n",
1388 				label);
1389 			return ENOENT;
1390 		}
1391 	}
1392 
1393 	/*
1394 	 * Acquire the pmp structure (it should have already been allocated
1395 	 * via hammer2_update_pmps()).
1396 	 */
1397 	if (chain->error) {
1398 		kprintf("hammer2_mount: PFS label I/O error\n");
1399 	} else {
1400 		ripdata = &chain->data->ipdata;
1401 		pmp = hammer2_pfsalloc(NULL, ripdata, force_local);
1402 	}
1403 	hammer2_chain_unlock(chain);
1404 	hammer2_chain_drop(chain);
1405 
1406 	/*
1407 	 * PFS to mount must exist at this point.
1408 	 */
1409 	if (pmp == NULL) {
1410 		kprintf("hammer2_mount: Failed to acquire PFS structure\n");
1411 		hammer2_unmount_helper(mp, NULL, hmp);
1412 		lockmgr(&hammer2_mntlk, LK_RELEASE);
1413 		hammer2_vfs_unmount(mp, MNT_FORCE);
1414 		return EINVAL;
1415 	}
1416 
1417 	/*
1418 	 * Finish the mount
1419 	 */
1420 	kprintf("hammer2_mount: hmp=%p pmp=%p\n", hmp, pmp);
1421 
1422 	/* Check if the pmp has already been mounted. */
1423 	if (pmp->mp) {
1424 		kprintf("hammer2_mount: PFS already mounted!\n");
1425 		hammer2_unmount_helper(mp, NULL, hmp);
1426 		lockmgr(&hammer2_mntlk, LK_RELEASE);
1427 		hammer2_vfs_unmount(mp, MNT_FORCE);
1428 		return EBUSY;
1429 	}
1430 
1431 	pmp->hflags = info.hflags;
1432 	mp->mnt_flag |= MNT_LOCAL;
1433 	mp->mnt_kern_flag |= MNTK_ALL_MPSAFE;   /* all entry pts are SMP */
1434 	mp->mnt_kern_flag |= MNTK_THR_SYNC;     /* new vsyncscan semantics */
1435 
1436 	/*
1437 	 * required mount structure initializations
1438 	 */
1439 	mp->mnt_stat.f_iosize = HAMMER2_PBUFSIZE;
1440 	mp->mnt_stat.f_bsize = HAMMER2_PBUFSIZE;
1441 
1442 	mp->mnt_vstat.f_frsize = HAMMER2_PBUFSIZE;
1443 	mp->mnt_vstat.f_bsize = HAMMER2_PBUFSIZE;
1444 
1445 	/*
1446 	 * Optional fields
1447 	 */
1448 	mp->mnt_iosize_max = MAXPHYS;
1449 
1450 	/*
1451 	 * Connect up mount pointers.
1452 	 */
1453 	hammer2_mount_helper(mp, pmp);
1454 	lockmgr(&hammer2_mntlk, LK_RELEASE);
1455 
1456 #if 0
1457 	/*
1458 	 * Finish setup
1459 	 */
1460 	vfs_getnewfsid(mp);
1461 	vfs_add_vnodeops(mp, &hammer2_vnode_vops, &mp->mnt_vn_norm_ops);
1462 	vfs_add_vnodeops(mp, &hammer2_spec_vops, &mp->mnt_vn_spec_ops);
1463 	vfs_add_vnodeops(mp, &hammer2_fifo_vops, &mp->mnt_vn_fifo_ops);
1464 
1465 	if (path) {
1466 		copyinstr(info.volume, mp->mnt_stat.f_mntfromname,
1467 			  MNAMELEN - 1, &size);
1468 		bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
1469 	} /* else root mount, already in there */
1470 
1471 	bzero(mp->mnt_stat.f_mntonname, sizeof(mp->mnt_stat.f_mntonname));
1472 	if (path) {
1473 		copyinstr(path, mp->mnt_stat.f_mntonname,
1474 			  sizeof(mp->mnt_stat.f_mntonname) - 1,
1475 			  &size);
1476 	} else {
1477 		/* root mount */
1478 		mp->mnt_stat.f_mntonname[0] = '/';
1479 	}
1480 #endif
1481 
1482 	/*
1483 	 * Initial statfs to prime mnt_stat.
1484 	 */
1485 	hammer2_vfs_statfs(mp, &mp->mnt_stat, NULL);
1486 	hammer2_vfs_statvfs(mp, &mp->mnt_vstat, NULL);
1487 
1488 	return 0;
1489 }
1490 
1491 /*
1492  * Scan PFSs under the super-root and create hammer2_pfs structures.
1493  */
1494 static
1495 void
1496 hammer2_update_pmps(hammer2_dev_t *hmp)
1497 {
1498 	const hammer2_inode_data_t *ripdata;
1499 	hammer2_chain_t *parent;
1500 	hammer2_chain_t *chain;
1501 	hammer2_dev_t *force_local;
1502 	hammer2_pfs_t *spmp;
1503 	hammer2_key_t key_next;
1504 	int error;
1505 
1506 	/*
1507 	 * Force local mount (disassociate all PFSs from their clusters).
1508 	 * Used primarily for debugging.
1509 	 */
1510 	force_local = (hmp->hflags & HMNT2_LOCAL) ? hmp : NULL;
1511 
1512 	/*
1513 	 * Lookup mount point under the media-localized super-root.
1514 	 *
1515 	 * cluster->pmp will incorrectly point to spmp and must be fixed
1516 	 * up later on.
1517 	 */
1518 	spmp = hmp->spmp;
1519 	hammer2_inode_lock(spmp->iroot, 0);
1520 	parent = hammer2_inode_chain(spmp->iroot, 0, HAMMER2_RESOLVE_ALWAYS);
1521 	chain = hammer2_chain_lookup(&parent, &key_next,
1522 					 HAMMER2_KEY_MIN, HAMMER2_KEY_MAX,
1523 					 &error, 0);
1524 	while (chain) {
1525 		if (chain->error) {
1526 			kprintf("I/O error scanning PFS labels\n");
1527 		} else if (chain->bref.type != HAMMER2_BREF_TYPE_INODE) {
1528 			kprintf("Non inode chain type %d under super-root\n",
1529 				chain->bref.type);
1530 		} else {
1531 			ripdata = &chain->data->ipdata;
1532 			hammer2_pfsalloc(chain, ripdata, force_local);
1533 		}
1534 		chain = hammer2_chain_next(&parent, chain, &key_next,
1535 					   key_next, HAMMER2_KEY_MAX,
1536 					   &error, 0);
1537 	}
1538 	if (parent) {
1539 		hammer2_chain_unlock(parent);
1540 		hammer2_chain_drop(parent);
1541 	}
1542 	hammer2_inode_unlock(spmp->iroot);
1543 }
1544 
1545 #if 0
1546 static
1547 int
1548 hammer2_remount(hammer2_dev_t *hmp, struct mount *mp, char *path __unused,
1549 		struct ucred *cred)
1550 {
1551 	hammer2_volume_t *vol;
1552 	struct m_vnode *devvp;
1553 	int i, error, result = 0;
1554 
1555 	if (!(hmp->ronly && (mp->mnt_kern_flag & MNTK_WANTRDWR)))
1556 		return 0;
1557 
1558 	for (i = 0; i < hmp->nvolumes; ++i) {
1559 		vol = &hmp->volumes[i];
1560 		devvp = vol->dev->devvp;
1561 		KKASSERT(devvp);
1562 		vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
1563 		VOP_OPEN(devvp, FREAD | FWRITE, FSCRED, NULL);
1564 		vn_unlock(devvp);
1565 		error = 0;
1566 		if (vol->id == HAMMER2_ROOT_VOLUME) {
1567 			error = hammer2_recovery(hmp);
1568 			if (error == 0)
1569 				error |= hammer2_fixup_pfses(hmp);
1570 		}
1571 		vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
1572 		if (error == 0) {
1573 			VOP_CLOSE(devvp, FREAD, NULL);
1574 		} else {
1575 			VOP_CLOSE(devvp, FREAD | FWRITE, NULL);
1576 		}
1577 		vn_unlock(devvp);
1578 		result |= error;
1579 	}
1580 	if (result == 0) {
1581 		kprintf("hammer2: enable read/write\n");
1582 		hmp->ronly = 0;
1583 	}
1584 
1585 	return result;
1586 }
1587 #endif
1588 
1589 int
1590 hammer2_vfs_unmount(struct mount *mp, int mntflags)
1591 {
1592 	hammer2_pfs_t *pmp;
1593 	int flags;
1594 	int error = 0;
1595 
1596 	pmp = MPTOPMP(mp);
1597 
1598 	if (pmp == NULL)
1599 		return(0);
1600 
1601 	lockmgr(&hammer2_mntlk, LK_EXCLUSIVE);
1602 
1603 	/*
1604 	 * If mount initialization proceeded far enough we must flush
1605 	 * its vnodes and sync the underlying mount points.  Three syncs
1606 	 * are required to fully flush the filesystem (freemap updates lag
1607 	 * by one flush, and one extra for safety).
1608 	 */
1609 	if (mntflags & MNT_FORCE)
1610 		flags = FORCECLOSE;
1611 	else
1612 		flags = 0;
1613 	if (pmp->iroot) {
1614 		error = vflush(mp, 0, flags);
1615 		if (error)
1616 			goto failed;
1617 		hammer2_vfs_sync(mp, MNT_WAIT);
1618 		hammer2_vfs_sync(mp, MNT_WAIT);
1619 		hammer2_vfs_sync(mp, MNT_WAIT);
1620 	}
1621 
1622 	/*
1623 	 * Cleanup the frontend support XOPS threads
1624 	 */
1625 	hammer2_xop_helper_cleanup(pmp);
1626 
1627 	if (pmp->mp)
1628 		hammer2_unmount_helper(mp, pmp, NULL);
1629 
1630 	error = 0;
1631 failed:
1632 	lockmgr(&hammer2_mntlk, LK_RELEASE);
1633 
1634 	return (error);
1635 }
1636 
1637 /*
1638  * Mount helper, hook the system mount into our PFS.
1639  * The mount lock is held.
1640  *
1641  * We must bump the mount_count on related devices for any
1642  * mounted PFSs.
1643  */
1644 static
1645 void
1646 hammer2_mount_helper(struct mount *mp, hammer2_pfs_t *pmp)
1647 {
1648 	hammer2_cluster_t *cluster;
1649 	hammer2_chain_t *rchain;
1650 	int i;
1651 
1652 	mp->mnt_data = (qaddr_t)pmp;
1653 	pmp->mp = mp;
1654 
1655 	/*
1656 	 * After pmp->mp is set we have to adjust hmp->mount_count.
1657 	 */
1658 	cluster = &pmp->iroot->cluster;
1659 	for (i = 0; i < cluster->nchains; ++i) {
1660 		rchain = cluster->array[i].chain;
1661 		if (rchain == NULL)
1662 			continue;
1663 		++rchain->hmp->mount_count;
1664 	}
1665 
1666 	/*
1667 	 * Create missing Xop threads
1668 	 */
1669 	hammer2_xop_helper_create(pmp);
1670 }
1671 
1672 /*
1673  * Unmount helper, unhook the system mount from our PFS.
1674  * The mount lock is held.
1675  *
1676  * If hmp is supplied a mount responsible for being the first to open
1677  * the block device failed and the block device and all PFSs using the
1678  * block device must be cleaned up.
1679  *
1680  * If pmp is supplied multiple devices might be backing the PFS and each
1681  * must be disconnected.  This might not be the last PFS using some of the
1682  * underlying devices.  Also, we have to adjust our hmp->mount_count
1683  * accounting for the devices backing the pmp which is now undergoing an
1684  * unmount.
1685  */
1686 static
1687 void
1688 hammer2_unmount_helper(struct mount *mp, hammer2_pfs_t *pmp, hammer2_dev_t *hmp)
1689 {
1690 	hammer2_cluster_t *cluster;
1691 	hammer2_chain_t *rchain;
1692 	int dumpcnt;
1693 	int i;
1694 
1695 	/*
1696 	 * If no device supplied this is a high-level unmount and we have to
1697 	 * to disconnect the mount, adjust mount_count, and locate devices
1698 	 * that might now have no mounts.
1699 	 */
1700 	if (pmp) {
1701 		KKASSERT(hmp == NULL);
1702 		KKASSERT(MPTOPMP(mp) == pmp);
1703 		pmp->mp = NULL;
1704 		mp->mnt_data = NULL;
1705 
1706 		/*
1707 		 * After pmp->mp is cleared we have to account for
1708 		 * mount_count.
1709 		 */
1710 		cluster = &pmp->iroot->cluster;
1711 		for (i = 0; i < cluster->nchains; ++i) {
1712 			rchain = cluster->array[i].chain;
1713 			if (rchain == NULL)
1714 				continue;
1715 			--rchain->hmp->mount_count;
1716 			/* scrapping hmp now may invalidate the pmp */
1717 		}
1718 again:
1719 		TAILQ_FOREACH(hmp, &hammer2_mntlist, mntentry) {
1720 			if (hmp->mount_count == 0) {
1721 				hammer2_unmount_helper(NULL, NULL, hmp);
1722 				goto again;
1723 			}
1724 		}
1725 		return;
1726 	}
1727 
1728 	/*
1729 	 * Try to terminate the block device.  We can't terminate it if
1730 	 * there are still PFSs referencing it.
1731 	 */
1732 	if (hmp->mount_count)
1733 		return;
1734 
1735 	/*
1736 	 * Decomission the network before we start messing with the
1737 	 * device and PFS.
1738 	 */
1739 	hammer2_iocom_uninit(hmp);
1740 
1741 	hammer2_bulkfree_uninit(hmp);
1742 	hammer2_pfsfree_scan(hmp, 0);
1743 
1744 	/*
1745 	 * Cycle the volume data lock as a safety (probably not needed any
1746 	 * more).  To ensure everything is out we need to flush at least
1747 	 * three times.  (1) The running of the sideq can dirty the
1748 	 * filesystem, (2) A normal flush can dirty the freemap, and
1749 	 * (3) ensure that the freemap is fully synchronized.
1750 	 *
1751 	 * The next mount's recovery scan can clean everything up but we want
1752 	 * to leave the filesystem in a 100% clean state on a normal unmount.
1753 	 */
1754 #if 0
1755 	hammer2_voldata_lock(hmp);
1756 	hammer2_voldata_unlock(hmp);
1757 #endif
1758 
1759 	/*
1760 	 * Flush whatever is left.  Unmounted but modified PFS's might still
1761 	 * have some dirty chains on them.
1762 	 */
1763 	hammer2_chain_lock(&hmp->vchain, HAMMER2_RESOLVE_ALWAYS);
1764 	hammer2_chain_lock(&hmp->fchain, HAMMER2_RESOLVE_ALWAYS);
1765 
1766 	if (hmp->fchain.flags & HAMMER2_CHAIN_FLUSH_MASK) {
1767 		hammer2_voldata_modify(hmp);
1768 		hammer2_flush(&hmp->fchain, HAMMER2_FLUSH_TOP |
1769 					    HAMMER2_FLUSH_ALL);
1770 	}
1771 	hammer2_chain_unlock(&hmp->fchain);
1772 
1773 	if (hmp->vchain.flags & HAMMER2_CHAIN_FLUSH_MASK) {
1774 		hammer2_flush(&hmp->vchain, HAMMER2_FLUSH_TOP |
1775 					    HAMMER2_FLUSH_ALL);
1776 	}
1777 	hammer2_chain_unlock(&hmp->vchain);
1778 
1779 	if ((hmp->vchain.flags | hmp->fchain.flags) &
1780 	    HAMMER2_CHAIN_FLUSH_MASK) {
1781 		kprintf("hammer2_unmount: chains left over after final sync\n");
1782 		kprintf("    vchain %08x\n", hmp->vchain.flags);
1783 		kprintf("    fchain %08x\n", hmp->fchain.flags);
1784 
1785 		if (hammer2_debug & 0x0010)
1786 			Debugger("entered debugger");
1787 	}
1788 
1789 	hammer2_pfsfree_scan(hmp, 1);
1790 
1791 	KKASSERT(hmp->spmp == NULL);
1792 
1793 	/*
1794 	 * Finish up with the device vnode
1795 	 */
1796 	if (!TAILQ_EMPTY(&hmp->devvpl)) {
1797 		hammer2_close_devvp(&hmp->devvpl, hmp->ronly);
1798 		hammer2_cleanup_devvp(&hmp->devvpl);
1799 	}
1800 	KKASSERT(TAILQ_EMPTY(&hmp->devvpl));
1801 
1802 	/*
1803 	 * Clear vchain/fchain flags that might prevent final cleanup
1804 	 * of these chains.
1805 	 */
1806 	if (hmp->vchain.flags & HAMMER2_CHAIN_MODIFIED) {
1807 		atomic_add_long(&hammer2_count_modified_chains, -1);
1808 		atomic_clear_int(&hmp->vchain.flags, HAMMER2_CHAIN_MODIFIED);
1809 		hammer2_pfs_memory_wakeup(hmp->vchain.pmp, -1);
1810 	}
1811 	if (hmp->vchain.flags & HAMMER2_CHAIN_UPDATE) {
1812 		atomic_clear_int(&hmp->vchain.flags, HAMMER2_CHAIN_UPDATE);
1813 	}
1814 
1815 	if (hmp->fchain.flags & HAMMER2_CHAIN_MODIFIED) {
1816 		atomic_add_long(&hammer2_count_modified_chains, -1);
1817 		atomic_clear_int(&hmp->fchain.flags, HAMMER2_CHAIN_MODIFIED);
1818 		hammer2_pfs_memory_wakeup(hmp->fchain.pmp, -1);
1819 	}
1820 	if (hmp->fchain.flags & HAMMER2_CHAIN_UPDATE) {
1821 		atomic_clear_int(&hmp->fchain.flags, HAMMER2_CHAIN_UPDATE);
1822 	}
1823 
1824 	dumpcnt = 50;
1825 	hammer2_dump_chain(&hmp->vchain, 0, 0, &dumpcnt, 'v', (u_int)-1);
1826 	dumpcnt = 50;
1827 	hammer2_dump_chain(&hmp->fchain, 0, 0, &dumpcnt, 'f', (u_int)-1);
1828 
1829 	/*
1830 	 * Final drop of embedded freemap root chain to
1831 	 * clean up fchain.core (fchain structure is not
1832 	 * flagged ALLOCATED so it is cleaned out and then
1833 	 * left to rot).
1834 	 */
1835 	hammer2_chain_drop(&hmp->fchain);
1836 
1837 	/*
1838 	 * Final drop of embedded volume root chain to clean
1839 	 * up vchain.core (vchain structure is not flagged
1840 	 * ALLOCATED so it is cleaned out and then left to
1841 	 * rot).
1842 	 */
1843 	hammer2_chain_drop(&hmp->vchain);
1844 
1845 	hammer2_io_cleanup(hmp, &hmp->iotree);
1846 	if (hmp->iofree_count) {
1847 		kprintf("io_cleanup: %d I/O's left hanging\n",
1848 			hmp->iofree_count);
1849 	}
1850 
1851 	TAILQ_REMOVE(&hammer2_mntlist, hmp, mntentry);
1852 	kmalloc_destroy_obj(&hmp->mchain);
1853 	kmalloc_destroy_obj(&hmp->mio);
1854 	kmalloc_destroy(&hmp->mmsg);
1855 	kfree(hmp, M_HAMMER2);
1856 }
1857 
1858 int
1859 hammer2_vfs_vget(struct mount *mp, struct m_vnode *dvp,
1860 		 ino_t ino, struct m_vnode **vpp)
1861 {
1862 	hammer2_xop_lookup_t *xop;
1863 	hammer2_pfs_t *pmp;
1864 	hammer2_inode_t *ip;
1865 	hammer2_tid_t inum;
1866 	int error;
1867 
1868 	inum = (hammer2_tid_t)ino & HAMMER2_DIRHASH_USERMSK;
1869 
1870 	error = 0;
1871 	pmp = MPTOPMP(mp);
1872 
1873 	/*
1874 	 * Easy if we already have it cached
1875 	 */
1876 	ip = hammer2_inode_lookup(pmp, inum);
1877 	if (ip) {
1878 		hammer2_inode_lock(ip, HAMMER2_RESOLVE_SHARED);
1879 		*vpp = hammer2_igetv(ip, &error);
1880 		hammer2_inode_unlock(ip);
1881 		hammer2_inode_drop(ip);		/* from lookup */
1882 
1883 		return error;
1884 	}
1885 
1886 	/*
1887 	 * Otherwise we have to find the inode
1888 	 */
1889 	xop = hammer2_xop_alloc(pmp->iroot, 0);
1890 	xop->lhc = inum;
1891 	hammer2_xop_start(&xop->head, &hammer2_lookup_desc);
1892 	error = hammer2_xop_collect(&xop->head, 0);
1893 
1894 	if (error == 0)
1895 		ip = hammer2_inode_get(pmp, &xop->head, -1, -1);
1896 	hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
1897 
1898 	if (ip) {
1899 		*vpp = hammer2_igetv(ip, &error);
1900 		hammer2_inode_unlock(ip);
1901 	} else {
1902 		*vpp = NULL;
1903 		error = ENOENT;
1904 	}
1905 	return (error);
1906 }
1907 
1908 int
1909 hammer2_vfs_root(struct mount *mp, struct m_vnode **vpp)
1910 {
1911 	hammer2_pfs_t *pmp;
1912 	struct m_vnode *vp;
1913 	int error;
1914 
1915 	pmp = MPTOPMP(mp);
1916 	if (pmp->iroot == NULL) {
1917 		kprintf("hammer2 (%s): no root inode\n",
1918 			mp->mnt_stat.f_mntfromname);
1919 		*vpp = NULL;
1920 		return EINVAL;
1921 	}
1922 
1923 	error = 0;
1924 	hammer2_inode_lock(pmp->iroot, HAMMER2_RESOLVE_SHARED);
1925 
1926 	while (pmp->inode_tid == 0) {
1927 		hammer2_xop_ipcluster_t *xop;
1928 		const hammer2_inode_meta_t *meta;
1929 
1930 		xop = hammer2_xop_alloc(pmp->iroot, HAMMER2_XOP_MODIFYING);
1931 		hammer2_xop_start(&xop->head, &hammer2_ipcluster_desc);
1932 		error = hammer2_xop_collect(&xop->head, 0);
1933 
1934 		if (error == 0) {
1935 			meta = &hammer2_xop_gdata(&xop->head)->ipdata.meta;
1936 			pmp->iroot->meta = *meta;
1937 			pmp->inode_tid = meta->pfs_inum + 1;
1938 			hammer2_xop_pdata(&xop->head);
1939 			/* meta invalid */
1940 
1941 			if (pmp->inode_tid < HAMMER2_INODE_START)
1942 				pmp->inode_tid = HAMMER2_INODE_START;
1943 			pmp->modify_tid =
1944 				xop->head.cluster.focus->bref.modify_tid + 1;
1945 #if 0
1946 			kprintf("PFS: Starting inode %jd\n",
1947 				(intmax_t)pmp->inode_tid);
1948 			kprintf("PMP focus good set nextino=%ld mod=%016jx\n",
1949 				pmp->inode_tid, pmp->modify_tid);
1950 #endif
1951 			//wakeup(&pmp->iroot); XXX
1952 
1953 			hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
1954 
1955 			/*
1956 			 * Prime the mount info.
1957 			 */
1958 			hammer2_vfs_statfs(mp, &mp->mnt_stat, NULL);
1959 			break;
1960 		}
1961 
1962 		/*
1963 		 * Loop, try again
1964 		 */
1965 		hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
1966 		hammer2_inode_unlock(pmp->iroot);
1967 		error = tsleep(&pmp->iroot, PCATCH, "h2root", hz);
1968 		hammer2_inode_lock(pmp->iroot, HAMMER2_RESOLVE_SHARED);
1969 		if (error == EINTR)
1970 			break;
1971 	}
1972 
1973 	if (error) {
1974 		hammer2_inode_unlock(pmp->iroot);
1975 		*vpp = NULL;
1976 	} else {
1977 		vp = hammer2_igetv(pmp->iroot, &error);
1978 		hammer2_inode_unlock(pmp->iroot);
1979 		*vpp = vp;
1980 	}
1981 
1982 	return (error);
1983 }
1984 
1985 /*
1986  * Filesystem status
1987  *
1988  * XXX incorporate ipdata->meta.inode_quota and data_quota
1989  */
1990 static
1991 int
1992 hammer2_vfs_statfs(struct mount *mp, struct statfs *sbp, struct ucred *cred)
1993 {
1994 	hammer2_pfs_t *pmp;
1995 	hammer2_dev_t *hmp;
1996 	hammer2_blockref_t bref;
1997 	struct statfs tmp;
1998 	int i;
1999 
2000 	/*
2001 	 * NOTE: iroot might not have validated the cluster yet.
2002 	 */
2003 	pmp = MPTOPMP(mp);
2004 
2005 	bzero(&tmp, sizeof(tmp));
2006 
2007 	for (i = 0; i < pmp->iroot->cluster.nchains; ++i) {
2008 		hmp = pmp->pfs_hmps[i];
2009 		if (hmp == NULL)
2010 			continue;
2011 		if (pmp->iroot->cluster.array[i].chain)
2012 			bref = pmp->iroot->cluster.array[i].chain->bref;
2013 		else
2014 			bzero(&bref, sizeof(bref));
2015 
2016 		tmp.f_files = bref.embed.stats.inode_count;
2017 		tmp.f_ffree = 0;
2018 		tmp.f_blocks = hmp->voldata.allocator_size /
2019 			       mp->mnt_vstat.f_bsize;
2020 		tmp.f_bfree = hmp->voldata.allocator_free /
2021 			      mp->mnt_vstat.f_bsize;
2022 		tmp.f_bavail = tmp.f_bfree;
2023 
2024 		if (cred && cred->cr_uid != 0) {
2025 			uint64_t adj;
2026 
2027 			/* 5% */
2028 			adj = hmp->free_reserved / mp->mnt_vstat.f_bsize;
2029 			tmp.f_blocks -= adj;
2030 			tmp.f_bfree -= adj;
2031 			tmp.f_bavail -= adj;
2032 		}
2033 
2034 		mp->mnt_stat.f_blocks = tmp.f_blocks;
2035 		mp->mnt_stat.f_bfree = tmp.f_bfree;
2036 		mp->mnt_stat.f_bavail = tmp.f_bavail;
2037 		mp->mnt_stat.f_files = tmp.f_files;
2038 		mp->mnt_stat.f_ffree = tmp.f_ffree;
2039 
2040 		*sbp = mp->mnt_stat;
2041 	}
2042 	return (0);
2043 }
2044 
2045 static
2046 int
2047 hammer2_vfs_statvfs(struct mount *mp, struct statvfs *sbp, struct ucred *cred)
2048 {
2049 	hammer2_pfs_t *pmp;
2050 	hammer2_dev_t *hmp;
2051 	hammer2_blockref_t bref;
2052 	struct statvfs tmp;
2053 	int i;
2054 
2055 	/*
2056 	 * NOTE: iroot might not have validated the cluster yet.
2057 	 */
2058 	pmp = MPTOPMP(mp);
2059 	bzero(&tmp, sizeof(tmp));
2060 
2061 	for (i = 0; i < pmp->iroot->cluster.nchains; ++i) {
2062 		hmp = pmp->pfs_hmps[i];
2063 		if (hmp == NULL)
2064 			continue;
2065 		if (pmp->iroot->cluster.array[i].chain)
2066 			bref = pmp->iroot->cluster.array[i].chain->bref;
2067 		else
2068 			bzero(&bref, sizeof(bref));
2069 
2070 		tmp.f_files = bref.embed.stats.inode_count;
2071 		tmp.f_ffree = 0;
2072 		tmp.f_blocks = hmp->voldata.allocator_size /
2073 			       mp->mnt_vstat.f_bsize;
2074 		tmp.f_bfree = hmp->voldata.allocator_free /
2075 			      mp->mnt_vstat.f_bsize;
2076 		tmp.f_bavail = tmp.f_bfree;
2077 
2078 		if (cred && cred->cr_uid != 0) {
2079 			uint64_t adj;
2080 
2081 			/* 5% */
2082 			adj = hmp->free_reserved / mp->mnt_vstat.f_bsize;
2083 			tmp.f_blocks -= adj;
2084 			tmp.f_bfree -= adj;
2085 			tmp.f_bavail -= adj;
2086 		}
2087 
2088 		mp->mnt_vstat.f_blocks = tmp.f_blocks;
2089 		mp->mnt_vstat.f_bfree = tmp.f_bfree;
2090 		mp->mnt_vstat.f_bavail = tmp.f_bavail;
2091 		mp->mnt_vstat.f_files = tmp.f_files;
2092 		mp->mnt_vstat.f_ffree = tmp.f_ffree;
2093 
2094 		*sbp = mp->mnt_vstat;
2095 	}
2096 	return (0);
2097 }
2098 
2099 /*
2100  * Mount-time recovery (RW mounts)
2101  *
2102  * Updates to the free block table are allowed to lag flushes by one
2103  * transaction.  In case of a crash, then on a fresh mount we must do an
2104  * incremental scan of the last committed transaction id and make sure that
2105  * all related blocks have been marked allocated.
2106  */
2107 struct hammer2_recovery_elm {
2108 	TAILQ_ENTRY(hammer2_recovery_elm) entry;
2109 	hammer2_chain_t *chain;
2110 	hammer2_tid_t sync_tid;
2111 };
2112 
2113 TAILQ_HEAD(hammer2_recovery_list, hammer2_recovery_elm);
2114 
2115 struct hammer2_recovery_info {
2116 	struct hammer2_recovery_list list;
2117 	hammer2_tid_t	mtid;
2118 	int	depth;
2119 };
2120 
2121 static int hammer2_recovery_scan(hammer2_dev_t *hmp,
2122 			hammer2_chain_t *parent,
2123 			struct hammer2_recovery_info *info,
2124 			hammer2_tid_t sync_tid);
2125 
2126 #define HAMMER2_RECOVERY_MAXDEPTH	10
2127 
2128 static
2129 int
2130 hammer2_recovery(hammer2_dev_t *hmp)
2131 {
2132 	struct hammer2_recovery_info info;
2133 	struct hammer2_recovery_elm *elm;
2134 	hammer2_chain_t *parent;
2135 	hammer2_tid_t sync_tid;
2136 	hammer2_tid_t mirror_tid;
2137 	int error;
2138 
2139 	hammer2_trans_init(hmp->spmp, 0);
2140 
2141 	sync_tid = hmp->voldata.freemap_tid;
2142 	mirror_tid = hmp->voldata.mirror_tid;
2143 
2144 	kprintf("hammer2_mount: \"%s\": ", hmp->devrepname);
2145 	if (sync_tid >= mirror_tid) {
2146 		kprintf("no recovery needed\n");
2147 	} else {
2148 		kprintf("freemap recovery %016jx-%016jx\n",
2149 			sync_tid + 1, mirror_tid);
2150 	}
2151 
2152 	TAILQ_INIT(&info.list);
2153 	info.depth = 0;
2154 	parent = hammer2_chain_lookup_init(&hmp->vchain, 0);
2155 	error = hammer2_recovery_scan(hmp, parent, &info, sync_tid);
2156 	hammer2_chain_lookup_done(parent);
2157 
2158 	while ((elm = TAILQ_FIRST(&info.list)) != NULL) {
2159 		TAILQ_REMOVE(&info.list, elm, entry);
2160 		parent = elm->chain;
2161 		sync_tid = elm->sync_tid;
2162 		kfree(elm, M_HAMMER2);
2163 
2164 		hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS);
2165 		error |= hammer2_recovery_scan(hmp, parent, &info,
2166 					      hmp->voldata.freemap_tid);
2167 		hammer2_chain_unlock(parent);
2168 		hammer2_chain_drop(parent);	/* drop elm->chain ref */
2169 	}
2170 
2171 	hammer2_trans_done(hmp->spmp, 0);
2172 
2173 	return error;
2174 }
2175 
2176 static
2177 int
2178 hammer2_recovery_scan(hammer2_dev_t *hmp, hammer2_chain_t *parent,
2179 		      struct hammer2_recovery_info *info,
2180 		      hammer2_tid_t sync_tid)
2181 {
2182 	const hammer2_inode_data_t *ripdata;
2183 	hammer2_chain_t *chain;
2184 	hammer2_blockref_t bref;
2185 	int tmp_error;
2186 	int rup_error;
2187 	int error;
2188 	int first;
2189 
2190 	/*
2191 	 * Adjust freemap to ensure that the block(s) are marked allocated.
2192 	 */
2193 	if (parent->bref.type != HAMMER2_BREF_TYPE_VOLUME) {
2194 		hammer2_freemap_adjust(hmp, &parent->bref,
2195 				       HAMMER2_FREEMAP_DORECOVER);
2196 	}
2197 
2198 	/*
2199 	 * Check type for recursive scan
2200 	 */
2201 	switch(parent->bref.type) {
2202 	case HAMMER2_BREF_TYPE_VOLUME:
2203 		/* data already instantiated */
2204 		break;
2205 	case HAMMER2_BREF_TYPE_INODE:
2206 		/*
2207 		 * Must instantiate data for DIRECTDATA test and also
2208 		 * for recursion.
2209 		 */
2210 		hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS);
2211 		ripdata = &parent->data->ipdata;
2212 		if (ripdata->meta.op_flags & HAMMER2_OPFLAG_DIRECTDATA) {
2213 			/* not applicable to recovery scan */
2214 			hammer2_chain_unlock(parent);
2215 			return 0;
2216 		}
2217 		hammer2_chain_unlock(parent);
2218 		break;
2219 	case HAMMER2_BREF_TYPE_INDIRECT:
2220 		/*
2221 		 * Must instantiate data for recursion
2222 		 */
2223 		hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS);
2224 		hammer2_chain_unlock(parent);
2225 		break;
2226 	case HAMMER2_BREF_TYPE_DIRENT:
2227 	case HAMMER2_BREF_TYPE_DATA:
2228 	case HAMMER2_BREF_TYPE_FREEMAP:
2229 	case HAMMER2_BREF_TYPE_FREEMAP_NODE:
2230 	case HAMMER2_BREF_TYPE_FREEMAP_LEAF:
2231 		/* not applicable to recovery scan */
2232 		return 0;
2233 		break;
2234 	default:
2235 		return HAMMER2_ERROR_BADBREF;
2236 	}
2237 
2238 	/*
2239 	 * Defer operation if depth limit reached.
2240 	 */
2241 	if (info->depth >= HAMMER2_RECOVERY_MAXDEPTH) {
2242 		struct hammer2_recovery_elm *elm;
2243 
2244 		elm = kmalloc(sizeof(*elm), M_HAMMER2, M_ZERO | M_WAITOK);
2245 		elm->chain = parent;
2246 		elm->sync_tid = sync_tid;
2247 		hammer2_chain_ref(parent);
2248 		TAILQ_INSERT_TAIL(&info->list, elm, entry);
2249 		/* unlocked by caller */
2250 
2251 		return(0);
2252 	}
2253 
2254 
2255 	/*
2256 	 * Recursive scan of the last flushed transaction only.  We are
2257 	 * doing this without pmp assignments so don't leave the chains
2258 	 * hanging around after we are done with them.
2259 	 *
2260 	 * error	Cumulative error this level only
2261 	 * rup_error	Cumulative error for recursion
2262 	 * tmp_error	Specific non-cumulative recursion error
2263 	 */
2264 	chain = NULL;
2265 	first = 1;
2266 	rup_error = 0;
2267 	error = 0;
2268 
2269 	for (;;) {
2270 		error |= hammer2_chain_scan(parent, &chain, &bref,
2271 					    &first,
2272 					    HAMMER2_LOOKUP_NODATA);
2273 
2274 		/*
2275 		 * Problem during scan or EOF
2276 		 */
2277 		if (error)
2278 			break;
2279 
2280 		/*
2281 		 * If this is a leaf
2282 		 */
2283 		if (chain == NULL) {
2284 			if (bref.mirror_tid > sync_tid) {
2285 				hammer2_freemap_adjust(hmp, &bref,
2286 						     HAMMER2_FREEMAP_DORECOVER);
2287 			}
2288 			continue;
2289 		}
2290 
2291 		/*
2292 		 * This may or may not be a recursive node.
2293 		 */
2294 		atomic_set_int(&chain->flags, HAMMER2_CHAIN_RELEASE);
2295 		if (bref.mirror_tid > sync_tid) {
2296 			++info->depth;
2297 			tmp_error = hammer2_recovery_scan(hmp, chain,
2298 							   info, sync_tid);
2299 			--info->depth;
2300 		} else {
2301 			tmp_error = 0;
2302 		}
2303 
2304 		/*
2305 		 * Flush the recovery at the PFS boundary to stage it for
2306 		 * the final flush of the super-root topology.
2307 		 */
2308 		if (tmp_error == 0 &&
2309 		    (bref.flags & HAMMER2_BREF_FLAG_PFSROOT) &&
2310 		    (chain->flags & HAMMER2_CHAIN_ONFLUSH)) {
2311 			hammer2_flush(chain, HAMMER2_FLUSH_TOP |
2312 					     HAMMER2_FLUSH_ALL);
2313 		}
2314 		rup_error |= tmp_error;
2315 	}
2316 	return ((error | rup_error) & ~HAMMER2_ERROR_EOF);
2317 }
2318 
2319 /*
2320  * This fixes up an error introduced in earlier H2 implementations where
2321  * moving a PFS inode into an indirect block wound up causing the
2322  * HAMMER2_BREF_FLAG_PFSROOT flag in the bref to get cleared.
2323  */
2324 static
2325 int
2326 hammer2_fixup_pfses(hammer2_dev_t *hmp)
2327 {
2328 	const hammer2_inode_data_t *ripdata;
2329 	hammer2_chain_t *parent;
2330 	hammer2_chain_t *chain;
2331 	hammer2_key_t key_next;
2332 	hammer2_pfs_t *spmp;
2333 	int error;
2334 
2335 	error = 0;
2336 
2337 	/*
2338 	 * Lookup mount point under the media-localized super-root.
2339 	 *
2340 	 * cluster->pmp will incorrectly point to spmp and must be fixed
2341 	 * up later on.
2342 	 */
2343 	spmp = hmp->spmp;
2344 	hammer2_inode_lock(spmp->iroot, 0);
2345 	parent = hammer2_inode_chain(spmp->iroot, 0, HAMMER2_RESOLVE_ALWAYS);
2346 	chain = hammer2_chain_lookup(&parent, &key_next,
2347 					 HAMMER2_KEY_MIN, HAMMER2_KEY_MAX,
2348 					 &error, 0);
2349 	while (chain) {
2350 		if (chain->bref.type != HAMMER2_BREF_TYPE_INODE)
2351 			continue;
2352 		if (chain->error) {
2353 			kprintf("I/O error scanning PFS labels\n");
2354 			error |= chain->error;
2355 		} else if ((chain->bref.flags &
2356 			    HAMMER2_BREF_FLAG_PFSROOT) == 0) {
2357 			int error2;
2358 
2359 			ripdata = &chain->data->ipdata;
2360 			hammer2_trans_init(hmp->spmp, 0);
2361 			error2 = hammer2_chain_modify(chain,
2362 						      chain->bref.modify_tid,
2363 						      0, 0);
2364 			if (error2 == 0) {
2365 				kprintf("hammer2: Correct mis-flagged PFS %s\n",
2366 					ripdata->filename);
2367 				chain->bref.flags |= HAMMER2_BREF_FLAG_PFSROOT;
2368 			} else {
2369 				error |= error2;
2370 			}
2371 			hammer2_flush(chain, HAMMER2_FLUSH_TOP |
2372 					     HAMMER2_FLUSH_ALL);
2373 			hammer2_trans_done(hmp->spmp, 0);
2374 		}
2375 		chain = hammer2_chain_next(&parent, chain, &key_next,
2376 					   key_next, HAMMER2_KEY_MAX,
2377 					   &error, 0);
2378 	}
2379 	if (parent) {
2380 		hammer2_chain_unlock(parent);
2381 		hammer2_chain_drop(parent);
2382 	}
2383 	hammer2_inode_unlock(spmp->iroot);
2384 
2385 	return error;
2386 }
2387 
2388 /*
2389  * Sync a mount point; this is called periodically on a per-mount basis from
2390  * the filesystem syncer, and whenever a user issues a sync.
2391  */
2392 int
2393 hammer2_vfs_sync(struct mount *mp, int waitfor)
2394 {
2395 	int error;
2396 
2397 	error = hammer2_vfs_sync_pmp(MPTOPMP(mp), waitfor);
2398 
2399 	return error;
2400 }
2401 
2402 /*
2403  * Because frontend operations lock vnodes before we get a chance to
2404  * lock the related inode, we can't just acquire a vnode lock without
2405  * risking a deadlock.  The frontend may be holding a vnode lock while
2406  * also blocked on our SYNCQ flag while trying to get the inode lock.
2407  *
2408  * To deal with this situation we can check the vnode lock situation
2409  * after locking the inode and perform a work-around.
2410  */
2411 int
2412 hammer2_vfs_sync_pmp(hammer2_pfs_t *pmp, int waitfor)
2413 {
2414 	hammer2_inode_t *ip;
2415 	hammer2_depend_t *depend;
2416 	hammer2_depend_t *depend_next;
2417 	struct m_vnode *vp;
2418 	uint32_t pass2;
2419 	int error;
2420 	int wakecount;
2421 	int dorestart;
2422 
2423 	/*
2424 	 * Move all inodes on sideq to syncq.  This will clear sideq.
2425 	 * This should represent all flushable inodes.  These inodes
2426 	 * will already have refs due to being on syncq or sideq.  We
2427 	 * must do this all at once with the spinlock held to ensure that
2428 	 * all inode dependencies are part of the same flush.
2429 	 *
2430 	 * We should be able to do this asynchronously from frontend
2431 	 * operations because we will be locking the inodes later on
2432 	 * to actually flush them, and that will partition any frontend
2433 	 * op using the same inode.  Either it has already locked the
2434 	 * inode and we will block, or it has not yet locked the inode
2435 	 * and it will block until we are finished flushing that inode.
2436 	 *
2437 	 * When restarting, only move the inodes flagged as PASS2 from
2438 	 * SIDEQ to SYNCQ.  PASS2 propagation by inode_lock4() and
2439 	 * inode_depend() are atomic with the spin-lock.
2440 	 */
2441 	hammer2_trans_init(pmp, HAMMER2_TRANS_ISFLUSH);
2442 #ifdef HAMMER2_DEBUG_SYNC
2443 	kprintf("FILESYSTEM SYNC BOUNDARY\n");
2444 #endif
2445 	dorestart = 0;
2446 
2447 	/*
2448 	 * Move inodes from depq to syncq, releasing the related
2449 	 * depend structures.
2450 	 */
2451 restart:
2452 #ifdef HAMMER2_DEBUG_SYNC
2453 	kprintf("FILESYSTEM SYNC RESTART (%d)\n", dorestart);
2454 #endif
2455 	hammer2_trans_setflags(pmp, 0/*HAMMER2_TRANS_COPYQ*/);
2456 	hammer2_trans_clearflags(pmp, HAMMER2_TRANS_RESCAN);
2457 
2458 	/*
2459 	 * Move inodes from depq to syncq.  When restarting, only depq's
2460 	 * marked pass2 are moved.
2461 	 */
2462 	hammer2_spin_ex(&pmp->list_spin);
2463 	depend_next = TAILQ_FIRST(&pmp->depq);
2464 	wakecount = 0;
2465 
2466 	while ((depend = depend_next) != NULL) {
2467 		depend_next = TAILQ_NEXT(depend, entry);
2468 		if (dorestart && depend->pass2 == 0)
2469 			continue;
2470 		TAILQ_FOREACH(ip, &depend->sideq, entry) {
2471 			KKASSERT(ip->flags & HAMMER2_INODE_SIDEQ);
2472 			atomic_set_int(&ip->flags, HAMMER2_INODE_SYNCQ);
2473 			atomic_clear_int(&ip->flags, HAMMER2_INODE_SIDEQ);
2474 			ip->depend = NULL;
2475 		}
2476 
2477 		/*
2478 		 * NOTE: pmp->sideq_count includes both sideq and syncq
2479 		 */
2480 		TAILQ_CONCAT(&pmp->syncq, &depend->sideq, entry);
2481 
2482 		depend->count = 0;
2483 		depend->pass2 = 0;
2484 		TAILQ_REMOVE(&pmp->depq, depend, entry);
2485 	}
2486 
2487 	hammer2_spin_unex(&pmp->list_spin);
2488 	hammer2_trans_clearflags(pmp, /*HAMMER2_TRANS_COPYQ |*/
2489 				      HAMMER2_TRANS_WAITING);
2490 	dorestart = 0;
2491 
2492 	/*
2493 	 * sideq_count may have dropped enough to allow us to unstall
2494 	 * the frontend.
2495 	 */
2496 	hammer2_pfs_memory_wakeup(pmp, 0);
2497 
2498 	/*
2499 	 * Now run through all inodes on syncq.
2500 	 *
2501 	 * Flush transactions only interlock with other flush transactions.
2502 	 * Any conflicting frontend operations will block on the inode, but
2503 	 * may hold a vnode lock while doing so.
2504 	 */
2505 	hammer2_spin_ex(&pmp->list_spin);
2506 	while ((ip = TAILQ_FIRST(&pmp->syncq)) != NULL) {
2507 		/*
2508 		 * Remove the inode from the SYNCQ, transfer the syncq ref
2509 		 * to us.  We must clear SYNCQ to allow any potential
2510 		 * front-end deadlock to proceed.  We must set PASS2 so
2511 		 * the dependency code knows what to do.
2512 		 */
2513 		pass2 = ip->flags;
2514 		cpu_ccfence();
2515 		if (atomic_cmpset_int(&ip->flags,
2516 			      pass2,
2517 			      (pass2 & ~(HAMMER2_INODE_SYNCQ |
2518 					 HAMMER2_INODE_SYNCQ_WAKEUP)) |
2519 			      HAMMER2_INODE_SYNCQ_PASS2) == 0)
2520 		{
2521 			continue;
2522 		}
2523 		TAILQ_REMOVE(&pmp->syncq, ip, entry);
2524 		--pmp->sideq_count;
2525 		hammer2_spin_unex(&pmp->list_spin);
2526 
2527 		/*
2528 		 * Tickle anyone waiting on ip->flags or the hysteresis
2529 		 * on the dirty inode count.
2530 		 */
2531 		if (pass2 & HAMMER2_INODE_SYNCQ_WAKEUP)
2532 			wakeup(&ip->flags);
2533 		if (++wakecount >= hammer2_limit_dirty_inodes / 20 + 1) {
2534 			wakecount = 0;
2535 			hammer2_pfs_memory_wakeup(pmp, 0);
2536 		}
2537 
2538 		/*
2539 		 * Relock the inode, and we inherit a ref from the above.
2540 		 * We will check for a race after we acquire the vnode.
2541 		 */
2542 		hammer2_mtx_ex(&ip->lock);
2543 
2544 		/*
2545 		 * We need the vp in order to vfsync() dirty buffers, so if
2546 		 * one isn't attached we can skip it.
2547 		 *
2548 		 * Ordering the inode lock and then the vnode lock has the
2549 		 * potential to deadlock.  If we had left SYNCQ set that could
2550 		 * also deadlock us against the frontend even if we don't hold
2551 		 * any locks, but the latter is not a problem now since we
2552 		 * cleared it.  igetv will temporarily release the inode lock
2553 		 * in a safe manner to work-around the deadlock.
2554 		 *
2555 		 * Unfortunately it is still possible to deadlock when the
2556 		 * frontend obtains multiple inode locks, because all the
2557 		 * related vnodes are already locked (nor can the vnode locks
2558 		 * be released and reacquired without messing up RECLAIM and
2559 		 * INACTIVE sequencing).
2560 		 *
2561 		 * The solution for now is to move the vp back onto SIDEQ
2562 		 * and set dorestart, which will restart the flush after we
2563 		 * exhaust the current SYNCQ.  Note that additional
2564 		 * dependencies may build up, so we definitely need to move
2565 		 * the whole SIDEQ back to SYNCQ when we restart.
2566 		 */
2567 		vp = ip->vp;
2568 		if (vp) {
2569 			if (vget(vp, LK_EXCLUSIVE|LK_NOWAIT)) {
2570 				/*
2571 				 * Failed to get the vnode, requeue the inode
2572 				 * (PASS2 is already set so it will be found
2573 				 * again on the restart).
2574 				 *
2575 				 * Then unlock, possibly sleep, and retry
2576 				 * later.  We sleep if PASS2 was *previously*
2577 				 * set, before we set it again above.
2578 				 */
2579 				vp = NULL;
2580 				dorestart = 1;
2581 #ifdef HAMMER2_DEBUG_SYNC
2582 				kprintf("inum %ld (sync delayed by vnode)\n",
2583 					(long)ip->meta.inum);
2584 #endif
2585 				hammer2_inode_delayed_sideq(ip);
2586 
2587 				hammer2_mtx_unlock(&ip->lock);
2588 				hammer2_inode_drop(ip);
2589 
2590 				if (pass2 & HAMMER2_INODE_SYNCQ_PASS2) {
2591 					tsleep(&dorestart, 0, "h2syndel", 2);
2592 				}
2593 				hammer2_spin_ex(&pmp->list_spin);
2594 				continue;
2595 			}
2596 		} else {
2597 			vp = NULL;
2598 		}
2599 
2600 		/*
2601 		 * If the inode wound up on a SIDEQ again it will already be
2602 		 * prepped for another PASS2.  In this situation if we flush
2603 		 * it now we will just wind up flushing it again in the same
2604 		 * syncer run, so we might as well not flush it now.
2605 		 */
2606 		if (ip->flags & HAMMER2_INODE_SIDEQ) {
2607 			hammer2_mtx_unlock(&ip->lock);
2608 			hammer2_inode_drop(ip);
2609 			if (vp)
2610 				vput(vp);
2611 			dorestart = 1;
2612 			hammer2_spin_ex(&pmp->list_spin);
2613 			continue;
2614 		}
2615 
2616 		/*
2617 		 * Ok we have the inode exclusively locked and if vp is
2618 		 * not NULL that will also be exclusively locked.  Do the
2619 		 * meat of the flush.
2620 		 *
2621 		 * vp token needed for v_rbdirty_tree check / vclrisdirty
2622 		 * sequencing.  Though we hold the vnode exclusively so
2623 		 * we shouldn't need to hold the token also in this case.
2624 		 */
2625 		if (vp) {
2626 			vfsync(vp, MNT_WAIT, 1, NULL, NULL);
2627 			bio_track_wait(NULL, 0, 0); /* XXX */
2628 		}
2629 
2630 		/*
2631 		 * If the inode has not yet been inserted into the tree
2632 		 * we must do so.  Then sync and flush it.  The flush should
2633 		 * update the parent.
2634 		 */
2635 		if (ip->flags & HAMMER2_INODE_DELETING) {
2636 #ifdef HAMMER2_DEBUG_SYNC
2637 			kprintf("inum %ld destroy\n", (long)ip->meta.inum);
2638 #endif
2639 			hammer2_inode_chain_des(ip);
2640 			atomic_add_long(&hammer2_iod_inode_deletes, 1);
2641 		} else if (ip->flags & HAMMER2_INODE_CREATING) {
2642 #ifdef HAMMER2_DEBUG_SYNC
2643 			kprintf("inum %ld insert\n", (long)ip->meta.inum);
2644 #endif
2645 			hammer2_inode_chain_ins(ip);
2646 			atomic_add_long(&hammer2_iod_inode_creates, 1);
2647 		}
2648 #ifdef HAMMER2_DEBUG_SYNC
2649 		kprintf("inum %ld chain-sync\n", (long)ip->meta.inum);
2650 #endif
2651 
2652 		/*
2653 		 * Because I kinda messed up the design and index the inodes
2654 		 * under the root inode, along side the directory entries,
2655 		 * we can't flush the inode index under the iroot until the
2656 		 * end.  If we do it now we might miss effects created by
2657 		 * other inodes on the SYNCQ.
2658 		 *
2659 		 * Do a normal (non-FSSYNC) flush instead, which allows the
2660 		 * vnode code to work the same.  We don't want to force iroot
2661 		 * back onto the SIDEQ, and we also don't want the flush code
2662 		 * to update pfs_iroot_blocksets until the final flush later.
2663 		 *
2664 		 * XXX at the moment this will likely result in a double-flush
2665 		 * of the iroot chain.
2666 		 */
2667 		hammer2_inode_chain_sync(ip);
2668 		if (ip == pmp->iroot) {
2669 			hammer2_inode_chain_flush(ip, HAMMER2_XOP_INODE_STOP);
2670 		} else {
2671 			hammer2_inode_chain_flush(ip, HAMMER2_XOP_INODE_STOP |
2672 						      HAMMER2_XOP_FSSYNC);
2673 		}
2674 		if (vp) {
2675 			lwkt_gettoken(NULL);
2676 			if ((ip->flags & (HAMMER2_INODE_MODIFIED |
2677 					  HAMMER2_INODE_RESIZED |
2678 					  HAMMER2_INODE_DIRTYDATA)) == 0) {
2679 			    //RB_EMPTY(&vp->v_rbdirty_tree) &&
2680 			    //!bio_track_active(&vp->v_track_write)) {
2681 				vclrisdirty(vp);
2682 			} else {
2683 				hammer2_inode_delayed_sideq(ip);
2684 			}
2685 			lwkt_reltoken(NULL);
2686 			vput(vp);
2687 			vp = NULL;	/* safety */
2688 		}
2689 		atomic_clear_int(&ip->flags, HAMMER2_INODE_SYNCQ_PASS2);
2690 		hammer2_inode_unlock(ip);	/* unlock+drop */
2691 		/* ip pointer invalid */
2692 
2693 		/*
2694 		 * If the inode got dirted after we dropped our locks,
2695 		 * it will have already been moved back to the SIDEQ.
2696 		 */
2697 		hammer2_spin_ex(&pmp->list_spin);
2698 	}
2699 	hammer2_spin_unex(&pmp->list_spin);
2700 	hammer2_pfs_memory_wakeup(pmp, 0);
2701 
2702 	if (dorestart || (pmp->trans.flags & HAMMER2_TRANS_RESCAN)) {
2703 #ifdef HAMMER2_DEBUG_SYNC
2704 		kprintf("FILESYSTEM SYNC STAGE 1 RESTART\n");
2705 		/*tsleep(&dorestart, 0, "h2STG1-R", hz*20);*/
2706 #endif
2707 		dorestart = 1;
2708 		goto restart;
2709 	}
2710 #ifdef HAMMER2_DEBUG_SYNC
2711 	kprintf("FILESYSTEM SYNC STAGE 2 BEGIN\n");
2712 	/*tsleep(&dorestart, 0, "h2STG2", hz*20);*/
2713 #endif
2714 
2715 	/*
2716 	 * We have to flush the PFS root last, even if it does not appear to
2717 	 * be dirty, because all the inodes in the PFS are indexed under it.
2718 	 * The normal flushing of iroot above would only occur if directory
2719 	 * entries under the root were changed.
2720 	 *
2721 	 * Specifying VOLHDR will cause an additionl flush of hmp->spmp
2722 	 * for the media making up the cluster.
2723 	 */
2724 	if ((ip = pmp->iroot) != NULL) {
2725 		hammer2_inode_ref(ip);
2726 		hammer2_mtx_ex(&ip->lock);
2727 		hammer2_inode_chain_sync(ip);
2728 		hammer2_inode_chain_flush(ip, HAMMER2_XOP_INODE_STOP |
2729 					      HAMMER2_XOP_FSSYNC |
2730 					      HAMMER2_XOP_VOLHDR);
2731 		hammer2_inode_unlock(ip);	/* unlock+drop */
2732 	}
2733 #ifdef HAMMER2_DEBUG_SYNC
2734 	kprintf("FILESYSTEM SYNC STAGE 2 DONE\n");
2735 #endif
2736 
2737 	/*
2738 	 * device bioq sync
2739 	 */
2740 	hammer2_bioq_sync(pmp);
2741 
2742 	error = 0;	/* XXX */
2743 	hammer2_trans_done(pmp, HAMMER2_TRANS_ISFLUSH);
2744 
2745 	return (error);
2746 }
2747 
2748 #if 0
2749 static
2750 int
2751 hammer2_vfs_vptofh(struct m_vnode *vp, struct fid *fhp)
2752 {
2753 	hammer2_inode_t *ip;
2754 
2755 	KKASSERT(MAXFIDSZ >= 16);
2756 	ip = VTOI(vp);
2757 	fhp->fid_len = offsetof(struct fid, fid_data[16]);
2758 	fhp->fid_ext = 0;
2759 	((hammer2_tid_t *)fhp->fid_data)[0] = ip->meta.inum;
2760 	((hammer2_tid_t *)fhp->fid_data)[1] = 0;
2761 
2762 	return 0;
2763 }
2764 
2765 static
2766 int
2767 hammer2_vfs_fhtovp(struct mount *mp, struct m_vnode *rootvp,
2768 	       struct fid *fhp, struct m_vnode **vpp)
2769 {
2770 	hammer2_tid_t inum;
2771 	int error;
2772 
2773 	inum = ((hammer2_tid_t *)fhp->fid_data)[0] & HAMMER2_DIRHASH_USERMSK;
2774 	if (vpp) {
2775 		if (inum == 1)
2776 			error = hammer2_vfs_root(mp, vpp);
2777 		else
2778 			error = hammer2_vfs_vget(mp, NULL, inum, vpp);
2779 	} else {
2780 		error = 0;
2781 	}
2782 	return error;
2783 }
2784 
2785 static
2786 int
2787 hammer2_vfs_checkexp(struct mount *mp, struct sockaddr *nam,
2788 		 int *exflagsp, struct ucred **credanonp)
2789 {
2790 	hammer2_pfs_t *pmp;
2791 	struct netcred *np;
2792 	int error;
2793 
2794 	pmp = MPTOPMP(mp);
2795 	np = vfs_export_lookup(mp, &pmp->export, nam);
2796 	if (np) {
2797 		*exflagsp = np->netc_exflags;
2798 		*credanonp = &np->netc_anon;
2799 		error = 0;
2800 	} else {
2801 		error = EACCES;
2802 	}
2803 	return error;
2804 }
2805 #endif
2806 
2807 /*
2808  * This handles hysteresis on regular file flushes.  Because the BIOs are
2809  * routed to a thread it is possible for an excessive number to build up
2810  * and cause long front-end stalls long before the runningbuffspace limit
2811  * is hit, so we implement hammer2_flush_pipe to control the
2812  * hysteresis.
2813  *
2814  * This is a particular problem when compression is used.
2815  */
2816 void
2817 hammer2_lwinprog_ref(hammer2_pfs_t *pmp)
2818 {
2819 	atomic_add_int(&pmp->count_lwinprog, 1);
2820 }
2821 
2822 void
2823 hammer2_lwinprog_drop(hammer2_pfs_t *pmp)
2824 {
2825 #if 0
2826 	int lwinprog;
2827 
2828 	lwinprog = atomic_fetchadd_int(&pmp->count_lwinprog, -1);
2829 	if ((lwinprog & HAMMER2_LWINPROG_WAITING) &&
2830 	    (lwinprog & HAMMER2_LWINPROG_MASK) <= hammer2_flush_pipe * 2 / 3) {
2831 		atomic_clear_int(&pmp->count_lwinprog,
2832 				 HAMMER2_LWINPROG_WAITING);
2833 		wakeup(&pmp->count_lwinprog);
2834 	}
2835 	if ((lwinprog & HAMMER2_LWINPROG_WAITING0) &&
2836 	    (lwinprog & HAMMER2_LWINPROG_MASK) <= 0) {
2837 		atomic_clear_int(&pmp->count_lwinprog,
2838 				 HAMMER2_LWINPROG_WAITING0);
2839 		wakeup(&pmp->count_lwinprog);
2840 	}
2841 #endif
2842 }
2843 
2844 void
2845 hammer2_lwinprog_wait(hammer2_pfs_t *pmp, int flush_pipe)
2846 {
2847 #if 0
2848 	int lwinprog;
2849 	int lwflag = (flush_pipe) ? HAMMER2_LWINPROG_WAITING :
2850 				    HAMMER2_LWINPROG_WAITING0;
2851 
2852 	for (;;) {
2853 		lwinprog = pmp->count_lwinprog;
2854 		cpu_ccfence();
2855 		if ((lwinprog & HAMMER2_LWINPROG_MASK) <= flush_pipe)
2856 			break;
2857 		tsleep_interlock(&pmp->count_lwinprog, 0);
2858 		atomic_set_int(&pmp->count_lwinprog, lwflag);
2859 		lwinprog = pmp->count_lwinprog;
2860 		if ((lwinprog & HAMMER2_LWINPROG_MASK) <= flush_pipe)
2861 			break;
2862 		tsleep(&pmp->count_lwinprog, PINTERLOCKED, "h2wpipe", hz);
2863 	}
2864 #endif
2865 }
2866 
2867 #if 0
2868 /*
2869  * It is possible for an excessive number of dirty chains or dirty inodes
2870  * to build up.  When this occurs we start an asynchronous filesystem sync.
2871  * If the level continues to build up, we stall, waiting for it to drop,
2872  * with some hysteresis.
2873  *
2874  * This relies on the kernel calling hammer2_vfs_modifying() prior to
2875  * obtaining any vnode locks before making a modifying VOP call.
2876  */
2877 static int
2878 hammer2_vfs_modifying(struct mount *mp)
2879 {
2880 	if (mp->mnt_flag & MNT_RDONLY)
2881 		return EROFS;
2882 	hammer2_pfs_memory_wait(MPTOPMP(mp));
2883 
2884 	return 0;
2885 }
2886 #endif
2887 
2888 /*
2889  * Initiate an asynchronous filesystem sync and, with hysteresis,
2890  * stall if the internal data structure count becomes too bloated.
2891  */
2892 void
2893 hammer2_pfs_memory_wait(hammer2_pfs_t *pmp)
2894 {
2895 	uint32_t waiting;
2896 	int pcatch;
2897 	int error;
2898 
2899 	if (pmp == NULL || pmp->mp == NULL)
2900 		return;
2901 
2902 	for (;;) {
2903 		waiting = pmp->inmem_dirty_chains & HAMMER2_DIRTYCHAIN_MASK;
2904 		cpu_ccfence();
2905 
2906 		/*
2907 		 * Start the syncer running at 1/2 the limit
2908 		 */
2909 		if (waiting > hammer2_limit_dirty_chains / 2 ||
2910 		    pmp->sideq_count > hammer2_limit_dirty_inodes / 2) {
2911 			trigger_syncer(pmp->mp);
2912 		}
2913 
2914 		/*
2915 		 * Stall at the limit waiting for the counts to drop.
2916 		 * This code will typically be woken up once the count
2917 		 * drops below 3/4 the limit, or in one second.
2918 		 */
2919 		if (waiting < hammer2_limit_dirty_chains &&
2920 		    pmp->sideq_count < hammer2_limit_dirty_inodes) {
2921 			break;
2922 		}
2923 
2924 		pcatch = curthread->td_proc ? PCATCH : 0;
2925 
2926 		tsleep_interlock(&pmp->inmem_dirty_chains, pcatch);
2927 		atomic_set_int(&pmp->inmem_dirty_chains,
2928 			       HAMMER2_DIRTYCHAIN_WAITING);
2929 		if (waiting < hammer2_limit_dirty_chains &&
2930 		    pmp->sideq_count < hammer2_limit_dirty_inodes) {
2931 			break;
2932 		}
2933 		trigger_syncer(pmp->mp);
2934 		error = tsleep(&pmp->inmem_dirty_chains, PINTERLOCKED | pcatch,
2935 			       "h2memw", hz);
2936 		if (error == ERESTART)
2937 			break;
2938 	}
2939 }
2940 
2941 /*
2942  * Wake up any stalled frontend ops waiting, with hysteresis, using
2943  * 2/3 of the limit.
2944  */
2945 void
2946 hammer2_pfs_memory_wakeup(hammer2_pfs_t *pmp, int count)
2947 {
2948 	uint32_t waiting;
2949 
2950 	if (pmp) {
2951 		waiting = atomic_fetchadd_int(&pmp->inmem_dirty_chains, count);
2952 		/* don't need --waiting to test flag */
2953 
2954 		if ((waiting & HAMMER2_DIRTYCHAIN_WAITING) &&
2955 		    (pmp->inmem_dirty_chains & HAMMER2_DIRTYCHAIN_MASK) <=
2956 		    hammer2_limit_dirty_chains * 2 / 3 &&
2957 		    pmp->sideq_count <= hammer2_limit_dirty_inodes * 2 / 3) {
2958 			atomic_clear_int(&pmp->inmem_dirty_chains,
2959 					 HAMMER2_DIRTYCHAIN_WAITING);
2960 			wakeup(&pmp->inmem_dirty_chains);
2961 		}
2962 	}
2963 }
2964 
2965 void
2966 hammer2_pfs_memory_inc(hammer2_pfs_t *pmp)
2967 {
2968 	if (pmp) {
2969 		atomic_add_int(&pmp->inmem_dirty_chains, 1);
2970 	}
2971 }
2972 
2973 /*
2974  * Volume header data locks
2975  */
2976 void
2977 hammer2_voldata_lock(hammer2_dev_t *hmp)
2978 {
2979 	lockmgr(&hmp->vollk, LK_EXCLUSIVE);
2980 }
2981 
2982 void
2983 hammer2_voldata_unlock(hammer2_dev_t *hmp)
2984 {
2985 	lockmgr(&hmp->vollk, LK_RELEASE);
2986 }
2987 
2988 /*
2989  * Caller indicates that the volume header is being modified.  Flag
2990  * the related chain and adjust its transaction id.
2991  *
2992  * The transaction id is set to voldata.mirror_tid + 1, similar to
2993  * what hammer2_chain_modify() does.  Be very careful here, volume
2994  * data can be updated independently of the rest of the filesystem.
2995  */
2996 void
2997 hammer2_voldata_modify(hammer2_dev_t *hmp)
2998 {
2999 	if ((hmp->vchain.flags & HAMMER2_CHAIN_MODIFIED) == 0) {
3000 		atomic_add_long(&hammer2_count_modified_chains, 1);
3001 		atomic_set_int(&hmp->vchain.flags, HAMMER2_CHAIN_MODIFIED);
3002 		hammer2_pfs_memory_inc(hmp->vchain.pmp);
3003 		hmp->vchain.bref.mirror_tid = hmp->voldata.mirror_tid + 1;
3004 	}
3005 }
3006 
3007 /*
3008  * Returns 0 if the filesystem has tons of free space
3009  * Returns 1 if the filesystem has less than 10% remaining
3010  * Returns 2 if the filesystem has less than 2%/5% (user/root) remaining.
3011  */
3012 int
3013 hammer2_vfs_enospace(hammer2_inode_t *ip, off_t bytes, struct ucred *cred)
3014 {
3015 	hammer2_pfs_t *pmp;
3016 	hammer2_dev_t *hmp;
3017 	hammer2_off_t free_reserved;
3018 	hammer2_off_t free_nominal;
3019 	int i;
3020 
3021 	pmp = ip->pmp;
3022 
3023 	if (/*XXX*/ 1 || pmp->free_ticks == 0 || pmp->free_ticks != ticks) {
3024 		free_reserved = HAMMER2_SEGSIZE;
3025 		free_nominal = 0x7FFFFFFFFFFFFFFFLLU;
3026 		for (i = 0; i < pmp->iroot->cluster.nchains; ++i) {
3027 			hmp = pmp->pfs_hmps[i];
3028 			if (hmp == NULL)
3029 				continue;
3030 			if (pmp->pfs_types[i] != HAMMER2_PFSTYPE_MASTER &&
3031 			    pmp->pfs_types[i] != HAMMER2_PFSTYPE_SOFT_MASTER)
3032 				continue;
3033 
3034 			if (free_nominal > hmp->voldata.allocator_free)
3035 				free_nominal = hmp->voldata.allocator_free;
3036 			if (free_reserved < hmp->free_reserved)
3037 				free_reserved = hmp->free_reserved;
3038 		}
3039 
3040 		/*
3041 		 * SMP races ok
3042 		 */
3043 		pmp->free_reserved = free_reserved;
3044 		pmp->free_nominal = free_nominal;
3045 		pmp->free_ticks = ticks;
3046 	} else {
3047 		free_reserved = pmp->free_reserved;
3048 		free_nominal = pmp->free_nominal;
3049 	}
3050 	if (cred && cred->cr_uid != 0) {
3051 		if ((int64_t)(free_nominal - bytes) <
3052 		    (int64_t)free_reserved) {
3053 			return 2;
3054 		}
3055 	} else {
3056 		if ((int64_t)(free_nominal - bytes) <
3057 		    (int64_t)free_reserved / 2) {
3058 			return 2;
3059 		}
3060 	}
3061 	if ((int64_t)(free_nominal - bytes) < (int64_t)free_reserved * 2)
3062 		return 1;
3063 	return 0;
3064 }
3065