xref: /dragonfly/sys/vfs/hammer2/hammer2_vfsops.c (revision 279dd846)
1 /*
2  * Copyright (c) 2011-2015 The DragonFly Project.  All rights reserved.
3  *
4  * This code is derived from software contributed to The DragonFly Project
5  * by Matthew Dillon <dillon@backplane.com>
6  * by Daniel Flores (GSOC 2013 - mentored by Matthew Dillon, compression)
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in
16  *    the documentation and/or other materials provided with the
17  *    distribution.
18  * 3. Neither the name of The DragonFly Project nor the names of its
19  *    contributors may be used to endorse or promote products derived
20  *    from this software without specific, prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
23  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
24  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
25  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
26  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
27  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
28  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
29  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
30  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
31  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
32  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/kernel.h>
38 #include <sys/nlookup.h>
39 #include <sys/vnode.h>
40 #include <sys/mount.h>
41 #include <sys/fcntl.h>
42 #include <sys/buf.h>
43 #include <sys/uuid.h>
44 #include <sys/vfsops.h>
45 #include <sys/sysctl.h>
46 #include <sys/socket.h>
47 #include <sys/objcache.h>
48 
49 #include <sys/proc.h>
50 #include <sys/namei.h>
51 #include <sys/mountctl.h>
52 #include <sys/dirent.h>
53 #include <sys/uio.h>
54 
55 #include <sys/mutex.h>
56 #include <sys/mutex2.h>
57 
58 #include "hammer2.h"
59 #include "hammer2_disk.h"
60 #include "hammer2_mount.h"
61 #include "hammer2_lz4.h"
62 
63 #include "zlib/hammer2_zlib.h"
64 
65 #define REPORT_REFS_ERRORS 1	/* XXX remove me */
66 
67 MALLOC_DEFINE(M_OBJCACHE, "objcache", "Object Cache");
68 
69 struct hammer2_sync_info {
70 	int error;
71 	int waitfor;
72 };
73 
74 TAILQ_HEAD(hammer2_mntlist, hammer2_dev);
75 TAILQ_HEAD(hammer2_pfslist, hammer2_pfs);
76 static struct hammer2_mntlist hammer2_mntlist;
77 static struct hammer2_pfslist hammer2_pfslist;
78 static struct lock hammer2_mntlk;
79 
80 int hammer2_debug;
81 int hammer2_cluster_enable = 1;
82 int hammer2_hardlink_enable = 1;
83 int hammer2_flush_pipe = 100;
84 int hammer2_synchronous_flush = 1;
85 int hammer2_dio_count;
86 long hammer2_limit_dirty_chains;
87 long hammer2_iod_file_read;
88 long hammer2_iod_meta_read;
89 long hammer2_iod_indr_read;
90 long hammer2_iod_fmap_read;
91 long hammer2_iod_volu_read;
92 long hammer2_iod_file_write;
93 long hammer2_iod_file_wembed;
94 long hammer2_iod_file_wzero;
95 long hammer2_iod_file_wdedup;
96 long hammer2_iod_meta_write;
97 long hammer2_iod_indr_write;
98 long hammer2_iod_fmap_write;
99 long hammer2_iod_volu_write;
100 long hammer2_ioa_file_read;
101 long hammer2_ioa_meta_read;
102 long hammer2_ioa_indr_read;
103 long hammer2_ioa_fmap_read;
104 long hammer2_ioa_volu_read;
105 long hammer2_ioa_fmap_write;
106 long hammer2_ioa_file_write;
107 long hammer2_ioa_meta_write;
108 long hammer2_ioa_indr_write;
109 long hammer2_ioa_volu_write;
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, debug, CTLFLAG_RW,
122 	   &hammer2_debug, 0, "");
123 SYSCTL_INT(_vfs_hammer2, OID_AUTO, cluster_enable, CTLFLAG_RW,
124 	   &hammer2_cluster_enable, 0, "");
125 SYSCTL_INT(_vfs_hammer2, OID_AUTO, hardlink_enable, CTLFLAG_RW,
126 	   &hammer2_hardlink_enable, 0, "");
127 SYSCTL_INT(_vfs_hammer2, OID_AUTO, flush_pipe, CTLFLAG_RW,
128 	   &hammer2_flush_pipe, 0, "");
129 SYSCTL_INT(_vfs_hammer2, OID_AUTO, synchronous_flush, CTLFLAG_RW,
130 	   &hammer2_synchronous_flush, 0, "");
131 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, limit_dirty_chains, CTLFLAG_RW,
132 	   &hammer2_limit_dirty_chains, 0, "");
133 SYSCTL_INT(_vfs_hammer2, OID_AUTO, dio_count, CTLFLAG_RD,
134 	   &hammer2_dio_count, 0, "");
135 
136 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_file_read, CTLFLAG_RW,
137 	   &hammer2_iod_file_read, 0, "");
138 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_meta_read, CTLFLAG_RW,
139 	   &hammer2_iod_meta_read, 0, "");
140 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_indr_read, CTLFLAG_RW,
141 	   &hammer2_iod_indr_read, 0, "");
142 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_fmap_read, CTLFLAG_RW,
143 	   &hammer2_iod_fmap_read, 0, "");
144 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_volu_read, CTLFLAG_RW,
145 	   &hammer2_iod_volu_read, 0, "");
146 
147 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_file_write, CTLFLAG_RW,
148 	   &hammer2_iod_file_write, 0, "");
149 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_file_wembed, CTLFLAG_RW,
150 	   &hammer2_iod_file_wembed, 0, "");
151 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_file_wzero, CTLFLAG_RW,
152 	   &hammer2_iod_file_wzero, 0, "");
153 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_file_wdedup, CTLFLAG_RW,
154 	   &hammer2_iod_file_wdedup, 0, "");
155 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_meta_write, CTLFLAG_RW,
156 	   &hammer2_iod_meta_write, 0, "");
157 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_indr_write, CTLFLAG_RW,
158 	   &hammer2_iod_indr_write, 0, "");
159 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_fmap_write, CTLFLAG_RW,
160 	   &hammer2_iod_fmap_write, 0, "");
161 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_volu_write, CTLFLAG_RW,
162 	   &hammer2_iod_volu_write, 0, "");
163 
164 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, ioa_file_read, CTLFLAG_RW,
165 	   &hammer2_ioa_file_read, 0, "");
166 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, ioa_meta_read, CTLFLAG_RW,
167 	   &hammer2_ioa_meta_read, 0, "");
168 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, ioa_indr_read, CTLFLAG_RW,
169 	   &hammer2_ioa_indr_read, 0, "");
170 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, ioa_fmap_read, CTLFLAG_RW,
171 	   &hammer2_ioa_fmap_read, 0, "");
172 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, ioa_volu_read, CTLFLAG_RW,
173 	   &hammer2_ioa_volu_read, 0, "");
174 
175 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, ioa_file_write, CTLFLAG_RW,
176 	   &hammer2_ioa_file_write, 0, "");
177 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, ioa_meta_write, CTLFLAG_RW,
178 	   &hammer2_ioa_meta_write, 0, "");
179 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, ioa_indr_write, CTLFLAG_RW,
180 	   &hammer2_ioa_indr_write, 0, "");
181 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, ioa_fmap_write, CTLFLAG_RW,
182 	   &hammer2_ioa_fmap_write, 0, "");
183 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, ioa_volu_write, CTLFLAG_RW,
184 	   &hammer2_ioa_volu_write, 0, "");
185 
186 static int hammer2_vfs_init(struct vfsconf *conf);
187 static int hammer2_vfs_uninit(struct vfsconf *vfsp);
188 static int hammer2_vfs_mount(struct mount *mp, char *path, caddr_t data,
189 				struct ucred *cred);
190 static int hammer2_remount(hammer2_dev_t *, struct mount *, char *,
191 				struct vnode *, struct ucred *);
192 static int hammer2_recovery(hammer2_dev_t *hmp);
193 static int hammer2_vfs_unmount(struct mount *mp, int mntflags);
194 static int hammer2_vfs_root(struct mount *mp, struct vnode **vpp);
195 static int hammer2_vfs_statfs(struct mount *mp, struct statfs *sbp,
196 				struct ucred *cred);
197 static int hammer2_vfs_statvfs(struct mount *mp, struct statvfs *sbp,
198 				struct ucred *cred);
199 static int hammer2_vfs_vget(struct mount *mp, struct vnode *dvp,
200 				ino_t ino, struct vnode **vpp);
201 static int hammer2_vfs_fhtovp(struct mount *mp, struct vnode *rootvp,
202 				struct fid *fhp, struct vnode **vpp);
203 static int hammer2_vfs_vptofh(struct vnode *vp, struct fid *fhp);
204 static int hammer2_vfs_checkexp(struct mount *mp, struct sockaddr *nam,
205 				int *exflagsp, struct ucred **credanonp);
206 
207 static int hammer2_install_volume_header(hammer2_dev_t *hmp);
208 static int hammer2_sync_scan2(struct mount *mp, struct vnode *vp, void *data);
209 
210 static void hammer2_update_pmps(hammer2_dev_t *hmp);
211 
212 static void hammer2_mount_helper(struct mount *mp, hammer2_pfs_t *pmp);
213 static void hammer2_unmount_helper(struct mount *mp, hammer2_pfs_t *pmp,
214 				hammer2_dev_t *hmp);
215 
216 /*
217  * HAMMER2 vfs operations.
218  */
219 static struct vfsops hammer2_vfsops = {
220 	.vfs_init	= hammer2_vfs_init,
221 	.vfs_uninit	= hammer2_vfs_uninit,
222 	.vfs_sync	= hammer2_vfs_sync,
223 	.vfs_mount	= hammer2_vfs_mount,
224 	.vfs_unmount	= hammer2_vfs_unmount,
225 	.vfs_root 	= hammer2_vfs_root,
226 	.vfs_statfs	= hammer2_vfs_statfs,
227 	.vfs_statvfs	= hammer2_vfs_statvfs,
228 	.vfs_vget	= hammer2_vfs_vget,
229 	.vfs_vptofh	= hammer2_vfs_vptofh,
230 	.vfs_fhtovp	= hammer2_vfs_fhtovp,
231 	.vfs_checkexp	= hammer2_vfs_checkexp
232 };
233 
234 MALLOC_DEFINE(M_HAMMER2, "HAMMER2-mount", "");
235 
236 VFS_SET(hammer2_vfsops, hammer2, 0);
237 MODULE_VERSION(hammer2, 1);
238 
239 static
240 int
241 hammer2_vfs_init(struct vfsconf *conf)
242 {
243 	static struct objcache_malloc_args margs_read;
244 	static struct objcache_malloc_args margs_write;
245 	static struct objcache_malloc_args margs_vop;
246 
247 	int error;
248 
249 	error = 0;
250 
251 	if (HAMMER2_BLOCKREF_BYTES != sizeof(struct hammer2_blockref))
252 		error = EINVAL;
253 	if (HAMMER2_INODE_BYTES != sizeof(struct hammer2_inode_data))
254 		error = EINVAL;
255 	if (HAMMER2_VOLUME_BYTES != sizeof(struct hammer2_volume_data))
256 		error = EINVAL;
257 
258 	if (error)
259 		kprintf("HAMMER2 structure size mismatch; cannot continue.\n");
260 
261 	margs_read.objsize = 65536;
262 	margs_read.mtype = M_HAMMER2_DEBUFFER;
263 
264 	margs_write.objsize = 32768;
265 	margs_write.mtype = M_HAMMER2_CBUFFER;
266 
267 	margs_vop.objsize = sizeof(hammer2_xop_t);
268 	margs_vop.mtype = M_HAMMER2;
269 
270 	/*
271 	 * Note thaht for the XOPS cache we want backing store allocations
272 	 * to use M_ZERO.  This is not allowed in objcache_get() (to avoid
273 	 * confusion), so use the backing store function that does it.  This
274 	 * means that initial XOPS objects are zerod but REUSED objects are
275 	 * not.  So we are responsible for cleaning the object up sufficiently
276 	 * for our needs before objcache_put()ing it back (typically just the
277 	 * FIFO indices).
278 	 */
279 	cache_buffer_read = objcache_create(margs_read.mtype->ks_shortdesc,
280 				0, 1, NULL, NULL, NULL,
281 				objcache_malloc_alloc,
282 				objcache_malloc_free,
283 				&margs_read);
284 	cache_buffer_write = objcache_create(margs_write.mtype->ks_shortdesc,
285 				0, 1, NULL, NULL, NULL,
286 				objcache_malloc_alloc,
287 				objcache_malloc_free,
288 				&margs_write);
289 	cache_xops = objcache_create(margs_vop.mtype->ks_shortdesc,
290 				0, 1, NULL, NULL, NULL,
291 				objcache_malloc_alloc_zero,
292 				objcache_malloc_free,
293 				&margs_vop);
294 
295 
296 	lockinit(&hammer2_mntlk, "mntlk", 0, 0);
297 	TAILQ_INIT(&hammer2_mntlist);
298 	TAILQ_INIT(&hammer2_pfslist);
299 
300 	hammer2_limit_dirty_chains = desiredvnodes / 10;
301 
302 	return (error);
303 }
304 
305 static
306 int
307 hammer2_vfs_uninit(struct vfsconf *vfsp __unused)
308 {
309 	objcache_destroy(cache_buffer_read);
310 	objcache_destroy(cache_buffer_write);
311 	objcache_destroy(cache_xops);
312 	return 0;
313 }
314 
315 /*
316  * Core PFS allocator.  Used to allocate the pmp structure for PFS cluster
317  * mounts and the spmp structure for media (hmp) structures.
318  *
319  * pmp->modify_tid tracks new modify_tid transaction ids for front-end
320  * transactions.  Note that synchronization does not use this field.
321  * (typically frontend operations and synchronization cannot run on the
322  * same PFS node at the same time).
323  *
324  * XXX check locking
325  */
326 hammer2_pfs_t *
327 hammer2_pfsalloc(hammer2_chain_t *chain, const hammer2_inode_data_t *ripdata,
328 		 hammer2_tid_t modify_tid)
329 {
330 	hammer2_inode_t *iroot;
331 	hammer2_pfs_t *pmp;
332 	int count;
333 	int i;
334 	int j;
335 
336 	/*
337 	 * Locate or create the PFS based on the cluster id.  If ripdata
338 	 * is NULL this is a spmp which is unique and is always allocated.
339 	 */
340 	if (ripdata) {
341 		TAILQ_FOREACH(pmp, &hammer2_pfslist, mntentry) {
342 			if (bcmp(&pmp->pfs_clid, &ripdata->meta.pfs_clid,
343 				 sizeof(pmp->pfs_clid)) == 0) {
344 					break;
345 			}
346 		}
347 	} else {
348 		pmp = NULL;
349 	}
350 
351 	if (pmp == NULL) {
352 		pmp = kmalloc(sizeof(*pmp), M_HAMMER2, M_WAITOK | M_ZERO);
353 		hammer2_trans_manage_init(pmp);
354 		kmalloc_create(&pmp->minode, "HAMMER2-inodes");
355 		kmalloc_create(&pmp->mmsg, "HAMMER2-pfsmsg");
356 		lockinit(&pmp->lock, "pfslk", 0, 0);
357 		spin_init(&pmp->inum_spin, "hm2pfsalloc_inum");
358 		spin_init(&pmp->xop_spin, "h2xop");
359 		RB_INIT(&pmp->inum_tree);
360 		TAILQ_INIT(&pmp->sideq);
361 		spin_init(&pmp->list_spin, "hm2pfsalloc_list");
362 
363 		/*
364 		 * Distribute backend operations to threads
365 		 */
366 		for (j = 0; j < HAMMER2_MAXCLUSTER; ++j)
367 			TAILQ_INIT(&pmp->xopq[j]);
368 		for (j = 0; j < HAMMER2_XOPGROUPS; ++j)
369 			hammer2_xop_group_init(pmp, &pmp->xop_groups[j]);
370 
371 		/*
372 		 * Save the last media transaction id for the flusher.  Set
373 		 * initial
374 		 */
375 		if (ripdata)
376 			pmp->pfs_clid = ripdata->meta.pfs_clid;
377 		TAILQ_INSERT_TAIL(&hammer2_pfslist, pmp, mntentry);
378 
379 		/*
380 		 * The synchronization thread may start too early, make
381 		 * sure it stays frozen until we are ready to let it go.
382 		 * XXX
383 		 */
384 		/*
385 		pmp->primary_thr.flags = HAMMER2_THREAD_FROZEN |
386 					 HAMMER2_THREAD_REMASTER;
387 		*/
388 	}
389 
390 	/*
391 	 * Create the PFS's root inode.
392 	 */
393 	if ((iroot = pmp->iroot) == NULL) {
394 		iroot = hammer2_inode_get(pmp, NULL, NULL, -1);
395 		pmp->iroot = iroot;
396 		hammer2_inode_ref(iroot);
397 		hammer2_inode_unlock(iroot);
398 	}
399 
400 	/*
401 	 * Stop here if no chain is passed in.
402 	 */
403 	if (chain == NULL)
404 		goto done;
405 
406 	/*
407 	 * When a chain is passed in we must add it to the PFS's root
408 	 * inode, update pmp->pfs_types[], and update the syncronization
409 	 * threads.
410 	 *
411 	 * At the moment empty spots can develop due to removals or failures.
412 	 * Ultimately we want to re-fill these spots but doing so might
413 	 * confused running code. XXX
414 	 */
415 	hammer2_inode_ref(iroot);
416 	hammer2_mtx_ex(&iroot->lock);
417 	j = iroot->cluster.nchains;
418 
419 	kprintf("add PFS to pmp %p[%d]\n", pmp, j);
420 
421 	if (j == HAMMER2_MAXCLUSTER) {
422 		kprintf("hammer2_mount: cluster full!\n");
423 		/* XXX fatal error? */
424 	} else {
425 		KKASSERT(chain->pmp == NULL);
426 		chain->pmp = pmp;
427 		hammer2_chain_ref(chain);
428 		iroot->cluster.array[j].chain = chain;
429 		pmp->pfs_types[j] = ripdata->meta.pfs_type;
430 		pmp->pfs_names[j] = kstrdup(ripdata->filename, M_HAMMER2);
431 		pmp->pfs_hmps[j] = chain->hmp;
432 
433 		/*
434 		 * If the PFS is already mounted we must account
435 		 * for the mount_count here.
436 		 */
437 		if (pmp->mp)
438 			++chain->hmp->mount_count;
439 
440 		/*
441 		 * May have to fixup dirty chain tracking.  Previous
442 		 * pmp was NULL so nothing to undo.
443 		 */
444 		if (chain->flags & HAMMER2_CHAIN_MODIFIED)
445 			hammer2_pfs_memory_inc(pmp);
446 		++j;
447 	}
448 	iroot->cluster.nchains = j;
449 
450 	/*
451 	 * Update nmasters from any PFS inode which is part of the cluster.
452 	 * It is possible that this will result in a value which is too
453 	 * high.  MASTER PFSs are authoritative for pfs_nmasters and will
454 	 * override this value later on.
455 	 *
456 	 * (This informs us of masters that might not currently be
457 	 *  discoverable by this mount).
458 	 */
459 	if (ripdata && pmp->pfs_nmasters < ripdata->meta.pfs_nmasters) {
460 		pmp->pfs_nmasters = ripdata->meta.pfs_nmasters;
461 	}
462 
463 	/*
464 	 * Count visible masters.  Masters are usually added with
465 	 * ripdata->meta.pfs_nmasters set to 1.  This detects when there
466 	 * are more (XXX and must update the master inodes).
467 	 */
468 	count = 0;
469 	for (i = 0; i < iroot->cluster.nchains; ++i) {
470 		if (pmp->pfs_types[i] == HAMMER2_PFSTYPE_MASTER)
471 			++count;
472 	}
473 	if (pmp->pfs_nmasters < count)
474 		pmp->pfs_nmasters = count;
475 
476 	/*
477 	 * Create missing synchronization and support threads.
478 	 *
479 	 * Single-node masters (including snapshots) have nothing to
480 	 * synchronize and do not require this thread.
481 	 *
482 	 * Multi-node masters or any number of soft masters, slaves, copy,
483 	 * or other PFS types need the thread.
484 	 *
485 	 * Each thread is responsible for its particular cluster index.
486 	 * We use independent threads so stalls or mismatches related to
487 	 * any given target do not affect other targets.
488 	 */
489 	for (i = 0; i < iroot->cluster.nchains; ++i) {
490 		/*
491 		 * Single-node masters (including snapshots) have nothing
492 		 * to synchronize and will make direct xops support calls,
493 		 * thus they do not require this thread.
494 		 *
495 		 * Note that there can be thousands of snapshots.  We do not
496 		 * want to create thousands of threads.
497 		 */
498 		if (pmp->pfs_nmasters <= 1 &&
499 		    pmp->pfs_types[i] == HAMMER2_PFSTYPE_MASTER) {
500 			continue;
501 		}
502 
503 		/*
504 		 * Sync support thread
505 		 */
506 		if (pmp->sync_thrs[i].td == NULL) {
507 			hammer2_thr_create(&pmp->sync_thrs[i], pmp,
508 					   "h2nod", i, -1,
509 					   hammer2_primary_sync_thread);
510 		}
511 	}
512 
513 	/*
514 	 * Create missing Xop threads
515 	 */
516 	if (pmp->mp)
517 		hammer2_xop_helper_create(pmp);
518 
519 	hammer2_mtx_unlock(&iroot->lock);
520 	hammer2_inode_drop(iroot);
521 done:
522 	return pmp;
523 }
524 
525 /*
526  * Destroy a PFS, typically only occurs after the last mount on a device
527  * has gone away.
528  */
529 static void
530 hammer2_pfsfree(hammer2_pfs_t *pmp)
531 {
532 	hammer2_inode_t *iroot;
533 	int i;
534 	int j;
535 
536 	/*
537 	 * Cleanup our reference on iroot.  iroot is (should) not be needed
538 	 * by the flush code.
539 	 */
540 	TAILQ_REMOVE(&hammer2_pfslist, pmp, mntentry);
541 
542 	iroot = pmp->iroot;
543 	if (iroot) {
544 		for (i = 0; i < iroot->cluster.nchains; ++i) {
545 			hammer2_thr_delete(&pmp->sync_thrs[i]);
546 			for (j = 0; j < HAMMER2_XOPGROUPS; ++j)
547 				hammer2_thr_delete(&pmp->xop_groups[j].thrs[i]);
548 		}
549 #if REPORT_REFS_ERRORS
550 		if (pmp->iroot->refs != 1)
551 			kprintf("PMP->IROOT %p REFS WRONG %d\n",
552 				pmp->iroot, pmp->iroot->refs);
553 #else
554 		KKASSERT(pmp->iroot->refs == 1);
555 #endif
556 		/* ref for pmp->iroot */
557 		hammer2_inode_drop(pmp->iroot);
558 		pmp->iroot = NULL;
559 	}
560 
561 	kmalloc_destroy(&pmp->mmsg);
562 	kmalloc_destroy(&pmp->minode);
563 
564 	kfree(pmp, M_HAMMER2);
565 }
566 
567 /*
568  * Remove all references to hmp from the pfs list.  Any PFS which becomes
569  * empty is terminated and freed.
570  *
571  * XXX inefficient.
572  */
573 static void
574 hammer2_pfsfree_scan(hammer2_dev_t *hmp)
575 {
576 	hammer2_pfs_t *pmp;
577 	hammer2_inode_t *iroot;
578 	hammer2_chain_t *rchain;
579 	int didfreeze;
580 	int i;
581 	int j;
582 
583 again:
584 	TAILQ_FOREACH(pmp, &hammer2_pfslist, mntentry) {
585 		if ((iroot = pmp->iroot) == NULL)
586 			continue;
587 		if (hmp->spmp == pmp) {
588 			kprintf("unmount hmp %p remove spmp %p\n",
589 				hmp, pmp);
590 			hmp->spmp = NULL;
591 		}
592 
593 		/*
594 		 * Determine if this PFS is affected.  If it is we must
595 		 * freeze all management threads and lock its iroot.
596 		 *
597 		 * Freezing a management thread forces it idle, operations
598 		 * in-progress will be aborted and it will have to start
599 		 * over again when unfrozen, or exit if told to exit.
600 		 */
601 		for (i = 0; i < HAMMER2_MAXCLUSTER; ++i) {
602 			if (pmp->pfs_hmps[i] == hmp)
603 				break;
604 		}
605 		if (i != HAMMER2_MAXCLUSTER) {
606 			/*
607 			 * Make sure all synchronization threads are locked
608 			 * down.
609 			 */
610 			for (i = 0; i < HAMMER2_MAXCLUSTER; ++i) {
611 				if (pmp->pfs_hmps[i] == NULL)
612 					continue;
613 				hammer2_thr_freeze_async(&pmp->sync_thrs[i]);
614 				for (j = 0; j < HAMMER2_XOPGROUPS; ++j) {
615 					hammer2_thr_freeze_async(
616 						&pmp->xop_groups[j].thrs[i]);
617 				}
618 			}
619 			for (i = 0; i < HAMMER2_MAXCLUSTER; ++i) {
620 				if (pmp->pfs_hmps[i] == NULL)
621 					continue;
622 				hammer2_thr_freeze(&pmp->sync_thrs[i]);
623 				for (j = 0; j < HAMMER2_XOPGROUPS; ++j) {
624 					hammer2_thr_freeze(
625 						&pmp->xop_groups[j].thrs[i]);
626 				}
627 			}
628 
629 			/*
630 			 * Lock the inode and clean out matching chains.
631 			 * Note that we cannot use hammer2_inode_lock_*()
632 			 * here because that would attempt to validate the
633 			 * cluster that we are in the middle of ripping
634 			 * apart.
635 			 *
636 			 * WARNING! We are working directly on the inodes
637 			 *	    embedded cluster.
638 			 */
639 			hammer2_mtx_ex(&iroot->lock);
640 
641 			/*
642 			 * Remove the chain from matching elements of the PFS.
643 			 */
644 			for (i = 0; i < HAMMER2_MAXCLUSTER; ++i) {
645 				if (pmp->pfs_hmps[i] != hmp)
646 					continue;
647 				hammer2_thr_delete(&pmp->sync_thrs[i]);
648 				for (j = 0; j < HAMMER2_XOPGROUPS; ++j) {
649 					hammer2_thr_delete(
650 						&pmp->xop_groups[j].thrs[i]);
651 				}
652 				rchain = iroot->cluster.array[i].chain;
653 				iroot->cluster.array[i].chain = NULL;
654 				pmp->pfs_types[i] = 0;
655 				if (pmp->pfs_names[i]) {
656 					kfree(pmp->pfs_names[i], M_HAMMER2);
657 					pmp->pfs_names[i] = NULL;
658 				}
659 				if (rchain) {
660 					hammer2_chain_drop(rchain);
661 					/* focus hint */
662 					if (iroot->cluster.focus == rchain)
663 						iroot->cluster.focus = NULL;
664 				}
665 				pmp->pfs_hmps[i] = NULL;
666 			}
667 			hammer2_mtx_unlock(&iroot->lock);
668 			didfreeze = 1;	/* remaster, unfreeze down below */
669 		} else {
670 			didfreeze = 0;
671 		}
672 
673 		/*
674 		 * Cleanup trailing chains.  Gaps may remain.
675 		 */
676 		for (i = HAMMER2_MAXCLUSTER - 1; i >= 0; --i) {
677 			if (pmp->pfs_hmps[i])
678 				break;
679 		}
680 		iroot->cluster.nchains = i + 1;
681 
682 		/*
683 		 * If the PMP has no elements remaining we can destroy it.
684 		 * (this will transition management threads from frozen->exit).
685 		 */
686 		if (iroot->cluster.nchains == 0) {
687 			kprintf("unmount hmp %p last ref to PMP=%p\n",
688 				hmp, pmp);
689 			hammer2_pfsfree(pmp);
690 			goto again;
691 		}
692 
693 		/*
694 		 * If elements still remain we need to set the REMASTER
695 		 * flag and unfreeze it.
696 		 */
697 		if (didfreeze) {
698 			for (i = 0; i < HAMMER2_MAXCLUSTER; ++i) {
699 				if (pmp->pfs_hmps[i] == NULL)
700 					continue;
701 				hammer2_thr_remaster(&pmp->sync_thrs[i]);
702 				hammer2_thr_unfreeze(&pmp->sync_thrs[i]);
703 				for (j = 0; j < HAMMER2_XOPGROUPS; ++j) {
704 					hammer2_thr_remaster(
705 						&pmp->xop_groups[j].thrs[i]);
706 					hammer2_thr_unfreeze(
707 						&pmp->xop_groups[j].thrs[i]);
708 				}
709 			}
710 		}
711 	}
712 }
713 
714 /*
715  * Mount or remount HAMMER2 fileystem from physical media
716  *
717  *	mountroot
718  *		mp		mount point structure
719  *		path		NULL
720  *		data		<unused>
721  *		cred		<unused>
722  *
723  *	mount
724  *		mp		mount point structure
725  *		path		path to mount point
726  *		data		pointer to argument structure in user space
727  *			volume	volume path (device@LABEL form)
728  *			hflags	user mount flags
729  *		cred		user credentials
730  *
731  * RETURNS:	0	Success
732  *		!0	error number
733  */
734 static
735 int
736 hammer2_vfs_mount(struct mount *mp, char *path, caddr_t data,
737 		  struct ucred *cred)
738 {
739 	struct hammer2_mount_info info;
740 	hammer2_pfs_t *pmp;
741 	hammer2_pfs_t *spmp;
742 	hammer2_dev_t *hmp;
743 	hammer2_key_t key_next;
744 	hammer2_key_t key_dummy;
745 	hammer2_key_t lhc;
746 	struct vnode *devvp;
747 	struct nlookupdata nd;
748 	hammer2_chain_t *parent;
749 	hammer2_chain_t *chain;
750 	hammer2_cluster_t *cluster;
751 	const hammer2_inode_data_t *ripdata;
752 	hammer2_blockref_t bref;
753 	struct file *fp;
754 	char devstr[MNAMELEN];
755 	size_t size;
756 	size_t done;
757 	char *dev;
758 	char *label;
759 	int ronly = 1;
760 	int error;
761 	int cache_index;
762 	int i;
763 
764 	hmp = NULL;
765 	pmp = NULL;
766 	dev = NULL;
767 	label = NULL;
768 	devvp = NULL;
769 	cache_index = -1;
770 
771 	kprintf("hammer2_mount\n");
772 
773 	if (path == NULL) {
774 		/*
775 		 * Root mount
776 		 */
777 		bzero(&info, sizeof(info));
778 		info.cluster_fd = -1;
779 		ksnprintf(devstr, sizeof(devstr), "%s",
780 			  mp->mnt_stat.f_mntfromname);
781 		kprintf("hammer2_mount: root '%s'\n", devstr);
782 	} else {
783 		/*
784 		 * Non-root mount or updating a mount
785 		 */
786 		error = copyin(data, &info, sizeof(info));
787 		if (error)
788 			return (error);
789 
790 		error = copyinstr(info.volume, devstr, MNAMELEN - 1, &done);
791 		if (error)
792 			return (error);
793 	}
794 
795 	/* Extract device and label */
796 	dev = devstr;
797 	label = strchr(devstr, '@');
798 	if (label == NULL ||
799 	    ((label + 1) - dev) > done) {
800 		return (EINVAL);
801 	}
802 	*label = '\0';
803 	label++;
804 	if (*label == '\0')
805 		return (EINVAL);
806 
807 	if (mp->mnt_flag & MNT_UPDATE) {
808 		/*
809 		 * Update mount.  Note that pmp->iroot->cluster is
810 		 * an inode-embedded cluster and thus cannot be
811 		 * directly locked.
812 		 *
813 		 * XXX HAMMER2 needs to implement NFS export via
814 		 *     mountctl.
815 		 */
816 		pmp = MPTOPMP(mp);
817 		cluster = &pmp->iroot->cluster;
818 		for (i = 0; i < cluster->nchains; ++i) {
819 			if (cluster->array[i].chain == NULL)
820 				continue;
821 			hmp = cluster->array[i].chain->hmp;
822 			devvp = hmp->devvp;
823 			error = hammer2_remount(hmp, mp, path,
824 						devvp, cred);
825 			if (error)
826 				break;
827 		}
828 
829 		return error;
830 	}
831 
832 	/*
833 	 * HMP device mount
834 	 *
835 	 * Lookup name and verify it refers to a block device.
836 	 */
837 	if (path) {
838 		error = nlookup_init(&nd, dev, UIO_SYSSPACE, NLC_FOLLOW);
839 		if (error == 0)
840 			error = nlookup(&nd);
841 		if (error == 0)
842 			error = cache_vref(&nd.nl_nch, nd.nl_cred, &devvp);
843 		nlookup_done(&nd);
844 	} else {
845 		/* root mount */
846 		cdev_t cdev = kgetdiskbyname(dev);
847 		error = bdevvp(cdev, &devvp);
848 		if (error)
849 			kprintf("hammer2: cannot find '%s'\n", dev);
850 	}
851 
852 	if (error == 0) {
853 		if (vn_isdisk(devvp, &error))
854 			error = vfs_mountedon(devvp);
855 	}
856 
857 	/*
858 	 * Determine if the device has already been mounted.  After this
859 	 * check hmp will be non-NULL if we are doing the second or more
860 	 * hammer2 mounts from the same device.
861 	 */
862 	lockmgr(&hammer2_mntlk, LK_EXCLUSIVE);
863 	TAILQ_FOREACH(hmp, &hammer2_mntlist, mntentry) {
864 		if (hmp->devvp == devvp)
865 			break;
866 	}
867 
868 	/*
869 	 * Open the device if this isn't a secondary mount and construct
870 	 * the H2 device mount (hmp).
871 	 */
872 	if (hmp == NULL) {
873 		hammer2_chain_t *schain;
874 		hammer2_xid_t xid;
875 
876 		if (error == 0 && vcount(devvp) > 0)
877 			error = EBUSY;
878 
879 		/*
880 		 * Now open the device
881 		 */
882 		if (error == 0) {
883 			ronly = ((mp->mnt_flag & MNT_RDONLY) != 0);
884 			vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
885 			error = vinvalbuf(devvp, V_SAVE, 0, 0);
886 			if (error == 0) {
887 				error = VOP_OPEN(devvp,
888 						 ronly ? FREAD : FREAD | FWRITE,
889 						 FSCRED, NULL);
890 			}
891 			vn_unlock(devvp);
892 		}
893 		if (error && devvp) {
894 			vrele(devvp);
895 			devvp = NULL;
896 		}
897 		if (error) {
898 			lockmgr(&hammer2_mntlk, LK_RELEASE);
899 			return error;
900 		}
901 		hmp = kmalloc(sizeof(*hmp), M_HAMMER2, M_WAITOK | M_ZERO);
902 		ksnprintf(hmp->devrepname, sizeof(hmp->devrepname), "%s", dev);
903 		hmp->ronly = ronly;
904 		hmp->devvp = devvp;
905 		kmalloc_create(&hmp->mchain, "HAMMER2-chains");
906 		TAILQ_INSERT_TAIL(&hammer2_mntlist, hmp, mntentry);
907 		RB_INIT(&hmp->iotree);
908 		spin_init(&hmp->io_spin, "hm2mount_io");
909 		spin_init(&hmp->list_spin, "hm2mount_list");
910 		TAILQ_INIT(&hmp->flushq);
911 
912 		lockinit(&hmp->vollk, "h2vol", 0, 0);
913 		lockinit(&hmp->bulklk, "h2bulk", 0, 0);
914 
915 		/*
916 		 * vchain setup. vchain.data is embedded.
917 		 * vchain.refs is initialized and will never drop to 0.
918 		 *
919 		 * NOTE! voldata is not yet loaded.
920 		 */
921 		hmp->vchain.hmp = hmp;
922 		hmp->vchain.refs = 1;
923 		hmp->vchain.data = (void *)&hmp->voldata;
924 		hmp->vchain.bref.type = HAMMER2_BREF_TYPE_VOLUME;
925 		hmp->vchain.bref.data_off = 0 | HAMMER2_PBUFRADIX;
926 		hmp->vchain.bref.mirror_tid = hmp->voldata.mirror_tid;
927 
928 		hammer2_chain_core_init(&hmp->vchain);
929 		/* hmp->vchain.u.xxx is left NULL */
930 
931 		/*
932 		 * fchain setup.  fchain.data is embedded.
933 		 * fchain.refs is initialized and will never drop to 0.
934 		 *
935 		 * The data is not used but needs to be initialized to
936 		 * pass assertion muster.  We use this chain primarily
937 		 * as a placeholder for the freemap's top-level RBTREE
938 		 * so it does not interfere with the volume's topology
939 		 * RBTREE.
940 		 */
941 		hmp->fchain.hmp = hmp;
942 		hmp->fchain.refs = 1;
943 		hmp->fchain.data = (void *)&hmp->voldata.freemap_blockset;
944 		hmp->fchain.bref.type = HAMMER2_BREF_TYPE_FREEMAP;
945 		hmp->fchain.bref.data_off = 0 | HAMMER2_PBUFRADIX;
946 		hmp->fchain.bref.mirror_tid = hmp->voldata.freemap_tid;
947 		hmp->fchain.bref.methods =
948 			HAMMER2_ENC_CHECK(HAMMER2_CHECK_FREEMAP) |
949 			HAMMER2_ENC_COMP(HAMMER2_COMP_NONE);
950 
951 		hammer2_chain_core_init(&hmp->fchain);
952 		/* hmp->fchain.u.xxx is left NULL */
953 
954 		/*
955 		 * Install the volume header and initialize fields from
956 		 * voldata.
957 		 */
958 		error = hammer2_install_volume_header(hmp);
959 		if (error) {
960 			hammer2_unmount_helper(mp, NULL, hmp);
961 			lockmgr(&hammer2_mntlk, LK_RELEASE);
962 			hammer2_vfs_unmount(mp, MNT_FORCE);
963 			return error;
964 		}
965 
966 		/*
967 		 * Really important to get these right or flush will get
968 		 * confused.
969 		 */
970 		hmp->spmp = hammer2_pfsalloc(NULL, NULL, 0);
971 		kprintf("alloc spmp %p tid %016jx\n",
972 			hmp->spmp, hmp->voldata.mirror_tid);
973 		spmp = hmp->spmp;
974 
975 		/*
976 		 * Dummy-up vchain and fchain's modify_tid.  mirror_tid
977 		 * is inherited from the volume header.
978 		 */
979 		xid = 0;
980 		hmp->vchain.bref.mirror_tid = hmp->voldata.mirror_tid;
981 		hmp->vchain.bref.modify_tid = hmp->vchain.bref.mirror_tid;
982 		hmp->vchain.pmp = spmp;
983 		hmp->fchain.bref.mirror_tid = hmp->voldata.freemap_tid;
984 		hmp->fchain.bref.modify_tid = hmp->fchain.bref.mirror_tid;
985 		hmp->fchain.pmp = spmp;
986 
987 		/*
988 		 * First locate the super-root inode, which is key 0
989 		 * relative to the volume header's blockset.
990 		 *
991 		 * Then locate the root inode by scanning the directory keyspace
992 		 * represented by the label.
993 		 */
994 		parent = hammer2_chain_lookup_init(&hmp->vchain, 0);
995 		schain = hammer2_chain_lookup(&parent, &key_dummy,
996 				      HAMMER2_SROOT_KEY, HAMMER2_SROOT_KEY,
997 				      &cache_index, 0);
998 		hammer2_chain_lookup_done(parent);
999 		if (schain == NULL) {
1000 			kprintf("hammer2_mount: invalid super-root\n");
1001 			hammer2_unmount_helper(mp, NULL, hmp);
1002 			lockmgr(&hammer2_mntlk, LK_RELEASE);
1003 			hammer2_vfs_unmount(mp, MNT_FORCE);
1004 			return EINVAL;
1005 		}
1006 		if (schain->error) {
1007 			kprintf("hammer2_mount: error %s reading super-root\n",
1008 				hammer2_error_str(schain->error));
1009 			hammer2_chain_unlock(schain);
1010 			hammer2_chain_drop(schain);
1011 			schain = NULL;
1012 			hammer2_unmount_helper(mp, NULL, hmp);
1013 			lockmgr(&hammer2_mntlk, LK_RELEASE);
1014 			hammer2_vfs_unmount(mp, MNT_FORCE);
1015 			return EINVAL;
1016 		}
1017 
1018 		/*
1019 		 * The super-root always uses an inode_tid of 1 when
1020 		 * creating PFSs.
1021 		 */
1022 		spmp->inode_tid = 1;
1023 		spmp->modify_tid = schain->bref.modify_tid + 1;
1024 
1025 		/*
1026 		 * Sanity-check schain's pmp and finish initialization.
1027 		 * Any chain belonging to the super-root topology should
1028 		 * have a NULL pmp (not even set to spmp).
1029 		 */
1030 		ripdata = &hammer2_chain_rdata(schain)->ipdata;
1031 		KKASSERT(schain->pmp == NULL);
1032 		spmp->pfs_clid = ripdata->meta.pfs_clid;
1033 
1034 		/*
1035 		 * Replace the dummy spmp->iroot with a real one.  It's
1036 		 * easier to just do a wholesale replacement than to try
1037 		 * to update the chain and fixup the iroot fields.
1038 		 *
1039 		 * The returned inode is locked with the supplied cluster.
1040 		 */
1041 		cluster = hammer2_cluster_from_chain(schain);
1042 		hammer2_inode_drop(spmp->iroot);
1043 		spmp->iroot = NULL;
1044 		spmp->iroot = hammer2_inode_get(spmp, NULL, cluster, -1);
1045 		spmp->spmp_hmp = hmp;
1046 		spmp->pfs_types[0] = ripdata->meta.pfs_type;
1047 		spmp->pfs_hmps[0] = hmp;
1048 		hammer2_inode_ref(spmp->iroot);
1049 		hammer2_inode_unlock(spmp->iroot);
1050 		hammer2_cluster_unlock(cluster);
1051 		hammer2_cluster_drop(cluster);
1052 		schain = NULL;
1053 		/* leave spmp->iroot with one ref */
1054 
1055 		if ((mp->mnt_flag & MNT_RDONLY) == 0) {
1056 			error = hammer2_recovery(hmp);
1057 			/* XXX do something with error */
1058 		}
1059 		hammer2_update_pmps(hmp);
1060 		hammer2_iocom_init(hmp);
1061 
1062 		/*
1063 		 * Ref the cluster management messaging descriptor.  The mount
1064 		 * program deals with the other end of the communications pipe.
1065 		 *
1066 		 * Root mounts typically do not supply one.
1067 		 */
1068 		if (info.cluster_fd >= 0) {
1069 			fp = holdfp(curproc->p_fd, info.cluster_fd, -1);
1070 			if (fp) {
1071 				hammer2_cluster_reconnect(hmp, fp);
1072 			} else {
1073 				kprintf("hammer2_mount: bad cluster_fd!\n");
1074 			}
1075 		}
1076 	} else {
1077 		spmp = hmp->spmp;
1078 	}
1079 
1080 	/*
1081 	 * Lookup the mount point under the media-localized super-root.
1082 	 * Scanning hammer2_pfslist doesn't help us because it represents
1083 	 * PFS cluster ids which can aggregate several named PFSs together.
1084 	 *
1085 	 * cluster->pmp will incorrectly point to spmp and must be fixed
1086 	 * up later on.
1087 	 */
1088 	hammer2_inode_lock(spmp->iroot, 0);
1089 	parent = hammer2_inode_chain(spmp->iroot, 0, HAMMER2_RESOLVE_ALWAYS);
1090 	lhc = hammer2_dirhash(label, strlen(label));
1091 	chain = hammer2_chain_lookup(&parent, &key_next,
1092 				     lhc, lhc + HAMMER2_DIRHASH_LOMASK,
1093 				     &cache_index, 0);
1094 	while (chain) {
1095 		if (chain->bref.type == HAMMER2_BREF_TYPE_INODE &&
1096 		    strcmp(label, chain->data->ipdata.filename) == 0) {
1097 			break;
1098 		}
1099 		chain = hammer2_chain_next(&parent, chain, &key_next,
1100 					    key_next,
1101 					    lhc + HAMMER2_DIRHASH_LOMASK,
1102 					    &cache_index, 0);
1103 	}
1104 	if (parent) {
1105 		hammer2_chain_unlock(parent);
1106 		hammer2_chain_drop(parent);
1107 	}
1108 	hammer2_inode_unlock(spmp->iroot);
1109 
1110 	/*
1111 	 * PFS could not be found?
1112 	 */
1113 	if (chain == NULL) {
1114 		kprintf("hammer2_mount: PFS label not found\n");
1115 		hammer2_unmount_helper(mp, NULL, hmp);
1116 		lockmgr(&hammer2_mntlk, LK_RELEASE);
1117 		hammer2_vfs_unmount(mp, MNT_FORCE);
1118 
1119 		return EINVAL;
1120 	}
1121 
1122 	/*
1123 	 * Acquire the pmp structure (it should have already been allocated
1124 	 * via hammer2_update_pmps() so do not pass cluster in to add to
1125 	 * available chains).
1126 	 *
1127 	 * Check if the cluster has already been mounted.  A cluster can
1128 	 * only be mounted once, use null mounts to mount additional copies.
1129 	 */
1130 	ripdata = &chain->data->ipdata;
1131 	bref = chain->bref;
1132 	pmp = hammer2_pfsalloc(NULL, ripdata, bref.modify_tid);
1133 	hammer2_chain_unlock(chain);
1134 	hammer2_chain_drop(chain);
1135 
1136 	if (pmp->mp) {
1137 		kprintf("hammer2_mount: PFS already mounted!\n");
1138 		hammer2_unmount_helper(mp, NULL, hmp);
1139 		lockmgr(&hammer2_mntlk, LK_RELEASE);
1140 		hammer2_vfs_unmount(mp, MNT_FORCE);
1141 
1142 		return EBUSY;
1143 	}
1144 
1145 	/*
1146 	 * Finish the mount
1147 	 */
1148         kprintf("hammer2_mount hmp=%p pmp=%p\n", hmp, pmp);
1149 
1150         mp->mnt_flag = MNT_LOCAL;
1151         mp->mnt_kern_flag |= MNTK_ALL_MPSAFE;   /* all entry pts are SMP */
1152         mp->mnt_kern_flag |= MNTK_THR_SYNC;     /* new vsyncscan semantics */
1153 
1154         /*
1155          * required mount structure initializations
1156          */
1157         mp->mnt_stat.f_iosize = HAMMER2_PBUFSIZE;
1158         mp->mnt_stat.f_bsize = HAMMER2_PBUFSIZE;
1159 
1160         mp->mnt_vstat.f_frsize = HAMMER2_PBUFSIZE;
1161         mp->mnt_vstat.f_bsize = HAMMER2_PBUFSIZE;
1162 
1163         /*
1164          * Optional fields
1165          */
1166         mp->mnt_iosize_max = MAXPHYS;
1167 
1168 	/*
1169 	 * Connect up mount pointers.
1170 	 */
1171 	hammer2_mount_helper(mp, pmp);
1172 
1173         lockmgr(&hammer2_mntlk, LK_RELEASE);
1174 
1175 	/*
1176 	 * Finish setup
1177 	 */
1178 	vfs_getnewfsid(mp);
1179 	vfs_add_vnodeops(mp, &hammer2_vnode_vops, &mp->mnt_vn_norm_ops);
1180 	vfs_add_vnodeops(mp, &hammer2_spec_vops, &mp->mnt_vn_spec_ops);
1181 	vfs_add_vnodeops(mp, &hammer2_fifo_vops, &mp->mnt_vn_fifo_ops);
1182 
1183 	if (path) {
1184 		copyinstr(info.volume, mp->mnt_stat.f_mntfromname,
1185 			  MNAMELEN - 1, &size);
1186 		bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
1187 	} /* else root mount, already in there */
1188 
1189 	bzero(mp->mnt_stat.f_mntonname, sizeof(mp->mnt_stat.f_mntonname));
1190 	if (path) {
1191 		copyinstr(path, mp->mnt_stat.f_mntonname,
1192 			  sizeof(mp->mnt_stat.f_mntonname) - 1,
1193 			  &size);
1194 	} else {
1195 		/* root mount */
1196 		mp->mnt_stat.f_mntonname[0] = '/';
1197 	}
1198 
1199 	/*
1200 	 * Initial statfs to prime mnt_stat.
1201 	 */
1202 	hammer2_vfs_statfs(mp, &mp->mnt_stat, cred);
1203 
1204 	return 0;
1205 }
1206 
1207 /*
1208  * Scan PFSs under the super-root and create hammer2_pfs structures.
1209  */
1210 static
1211 void
1212 hammer2_update_pmps(hammer2_dev_t *hmp)
1213 {
1214 	const hammer2_inode_data_t *ripdata;
1215 	hammer2_chain_t *parent;
1216 	hammer2_chain_t *chain;
1217 	hammer2_blockref_t bref;
1218 	hammer2_pfs_t *spmp;
1219 	hammer2_pfs_t *pmp;
1220 	hammer2_key_t key_next;
1221 	int cache_index = -1;
1222 
1223 	/*
1224 	 * Lookup mount point under the media-localized super-root.
1225 	 *
1226 	 * cluster->pmp will incorrectly point to spmp and must be fixed
1227 	 * up later on.
1228 	 */
1229 	spmp = hmp->spmp;
1230 	hammer2_inode_lock(spmp->iroot, 0);
1231 	parent = hammer2_inode_chain(spmp->iroot, 0, HAMMER2_RESOLVE_ALWAYS);
1232 	chain = hammer2_chain_lookup(&parent, &key_next,
1233 					 HAMMER2_KEY_MIN, HAMMER2_KEY_MAX,
1234 					 &cache_index, 0);
1235 	while (chain) {
1236 		if (chain->bref.type != HAMMER2_BREF_TYPE_INODE)
1237 			continue;
1238 		ripdata = &chain->data->ipdata;
1239 		bref = chain->bref;
1240 		kprintf("ADD LOCAL PFS: %s\n", ripdata->filename);
1241 
1242 		pmp = hammer2_pfsalloc(chain, ripdata, bref.modify_tid);
1243 		chain = hammer2_chain_next(&parent, chain, &key_next,
1244 					   key_next, HAMMER2_KEY_MAX,
1245 					   &cache_index, 0);
1246 	}
1247 	if (parent) {
1248 		hammer2_chain_unlock(parent);
1249 		hammer2_chain_drop(parent);
1250 	}
1251 	hammer2_inode_unlock(spmp->iroot);
1252 }
1253 
1254 static
1255 int
1256 hammer2_remount(hammer2_dev_t *hmp, struct mount *mp, char *path __unused,
1257 		struct vnode *devvp, struct ucred *cred)
1258 {
1259 	int error;
1260 
1261 	if (hmp->ronly && (mp->mnt_kern_flag & MNTK_WANTRDWR)) {
1262 		error = hammer2_recovery(hmp);
1263 	} else {
1264 		error = 0;
1265 	}
1266 	return error;
1267 }
1268 
1269 static
1270 int
1271 hammer2_vfs_unmount(struct mount *mp, int mntflags)
1272 {
1273 	hammer2_pfs_t *pmp;
1274 	int flags;
1275 	int error = 0;
1276 
1277 	pmp = MPTOPMP(mp);
1278 
1279 	if (pmp == NULL)
1280 		return(0);
1281 
1282 	lockmgr(&hammer2_mntlk, LK_EXCLUSIVE);
1283 
1284 	/*
1285 	 * If mount initialization proceeded far enough we must flush
1286 	 * its vnodes and sync the underlying mount points.  Three syncs
1287 	 * are required to fully flush the filesystem (freemap updates lag
1288 	 * by one flush, and one extra for safety).
1289 	 */
1290 	if (mntflags & MNT_FORCE)
1291 		flags = FORCECLOSE;
1292 	else
1293 		flags = 0;
1294 	if (pmp->iroot) {
1295 		error = vflush(mp, 0, flags);
1296 		if (error)
1297 			goto failed;
1298 		hammer2_vfs_sync(mp, MNT_WAIT);
1299 		hammer2_vfs_sync(mp, MNT_WAIT);
1300 		hammer2_vfs_sync(mp, MNT_WAIT);
1301 	}
1302 
1303 	/*
1304 	 * Cleanup the frontend support XOPS threads
1305 	 */
1306 	hammer2_xop_helper_cleanup(pmp);
1307 
1308 	/*
1309 	 * Cleanup our reference on ihidden.
1310 	 */
1311 	if (pmp->ihidden) {
1312 		hammer2_inode_drop(pmp->ihidden);
1313 		pmp->ihidden = NULL;
1314 	}
1315 	if (pmp->mp)
1316 		hammer2_unmount_helper(mp, pmp, NULL);
1317 
1318 	error = 0;
1319 failed:
1320 	lockmgr(&hammer2_mntlk, LK_RELEASE);
1321 
1322 	return (error);
1323 }
1324 
1325 /*
1326  * Mount helper, hook the system mount into our PFS.
1327  * The mount lock is held.
1328  *
1329  * We must bump the mount_count on related devices for any
1330  * mounted PFSs.
1331  */
1332 static
1333 void
1334 hammer2_mount_helper(struct mount *mp, hammer2_pfs_t *pmp)
1335 {
1336 	hammer2_cluster_t *cluster;
1337 	hammer2_chain_t *rchain;
1338 	int i;
1339 
1340         mp->mnt_data = (qaddr_t)pmp;
1341 	pmp->mp = mp;
1342 
1343 	/*
1344 	 * After pmp->mp is set we have to adjust hmp->mount_count.
1345 	 */
1346 	cluster = &pmp->iroot->cluster;
1347 	for (i = 0; i < cluster->nchains; ++i) {
1348 		rchain = cluster->array[i].chain;
1349 		if (rchain == NULL)
1350 			continue;
1351 		++rchain->hmp->mount_count;
1352 		kprintf("hammer2_mount hmp=%p ++mount_count=%d\n",
1353 			rchain->hmp, rchain->hmp->mount_count);
1354 	}
1355 
1356 	/*
1357 	 * Create missing Xop threads
1358 	 */
1359 	hammer2_xop_helper_create(pmp);
1360 }
1361 
1362 /*
1363  * Mount helper, unhook the system mount from our PFS.
1364  * The mount lock is held.
1365  *
1366  * If hmp is supplied a mount responsible for being the first to open
1367  * the block device failed and the block device and all PFSs using the
1368  * block device must be cleaned up.
1369  *
1370  * If pmp is supplied multiple devices might be backing the PFS and each
1371  * must be disconnect.  This might not be the last PFS using some of the
1372  * underlying devices.  Also, we have to adjust our hmp->mount_count
1373  * accounting for the devices backing the pmp which is now undergoing an
1374  * unmount.
1375  */
1376 static
1377 void
1378 hammer2_unmount_helper(struct mount *mp, hammer2_pfs_t *pmp, hammer2_dev_t *hmp)
1379 {
1380 	hammer2_cluster_t *cluster;
1381 	hammer2_chain_t *rchain;
1382 	struct vnode *devvp;
1383 	int dumpcnt;
1384 	int ronly = 0;
1385 	int i;
1386 
1387 	/*
1388 	 * If no device supplied this is a high-level unmount and we have to
1389 	 * to disconnect the mount, adjust mount_count, and locate devices
1390 	 * that might now have no mounts.
1391 	 */
1392 	if (pmp) {
1393 		KKASSERT(hmp == NULL);
1394 		KKASSERT((void *)(intptr_t)mp->mnt_data == pmp);
1395 		pmp->mp = NULL;
1396 		mp->mnt_data = NULL;
1397 
1398 		/*
1399 		 * After pmp->mp is cleared we have to account for
1400 		 * mount_count.
1401 		 */
1402 		cluster = &pmp->iroot->cluster;
1403 		for (i = 0; i < cluster->nchains; ++i) {
1404 			rchain = cluster->array[i].chain;
1405 			if (rchain == NULL)
1406 				continue;
1407 			--rchain->hmp->mount_count;
1408 			kprintf("hammer2_unmount hmp=%p --mount_count=%d\n",
1409 				rchain->hmp, rchain->hmp->mount_count);
1410 			/* scrapping hmp now may invalidate the pmp */
1411 		}
1412 again:
1413 		TAILQ_FOREACH(hmp, &hammer2_mntlist, mntentry) {
1414 			if (hmp->mount_count == 0) {
1415 				hammer2_unmount_helper(NULL, NULL, hmp);
1416 				goto again;
1417 			}
1418 		}
1419 		return;
1420 	}
1421 
1422 	/*
1423 	 * Try to terminate the block device.  We can't terminate it if
1424 	 * there are still PFSs referencing it.
1425 	 */
1426 	kprintf("hammer2_unmount hmp=%p mount_count=%d\n",
1427 		hmp, hmp->mount_count);
1428 	if (hmp->mount_count)
1429 		return;
1430 
1431 	hammer2_pfsfree_scan(hmp);
1432 	hammer2_dev_exlock(hmp);	/* XXX order */
1433 
1434 	/*
1435 	 * Cycle the volume data lock as a safety (probably not needed any
1436 	 * more).  To ensure everything is out we need to flush at least
1437 	 * three times.  (1) The running of the sideq can dirty the
1438 	 * filesystem, (2) A normal flush can dirty the freemap, and
1439 	 * (3) ensure that the freemap is fully synchronized.
1440 	 *
1441 	 * The next mount's recovery scan can clean everything up but we want
1442 	 * to leave the filesystem in a 100% clean state on a normal unmount.
1443 	 */
1444 #if 0
1445 	hammer2_voldata_lock(hmp);
1446 	hammer2_voldata_unlock(hmp);
1447 #endif
1448 	hammer2_iocom_uninit(hmp);
1449 
1450 	if ((hmp->vchain.flags | hmp->fchain.flags) &
1451 	    HAMMER2_CHAIN_FLUSH_MASK) {
1452 		kprintf("hammer2_unmount: chains left over "
1453 			"after final sync\n");
1454 		kprintf("    vchain %08x\n", hmp->vchain.flags);
1455 		kprintf("    fchain %08x\n", hmp->fchain.flags);
1456 
1457 		if (hammer2_debug & 0x0010)
1458 			Debugger("entered debugger");
1459 	}
1460 
1461 	KKASSERT(hmp->spmp == NULL);
1462 
1463 	/*
1464 	 * Finish up with the device vnode
1465 	 */
1466 	if ((devvp = hmp->devvp) != NULL) {
1467 		vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
1468 		vinvalbuf(devvp, (ronly ? 0 : V_SAVE), 0, 0);
1469 		hmp->devvp = NULL;
1470 		VOP_CLOSE(devvp, (ronly ? FREAD : FREAD|FWRITE), NULL);
1471 		vn_unlock(devvp);
1472 		vrele(devvp);
1473 		devvp = NULL;
1474 	}
1475 
1476 	/*
1477 	 * Clear vchain/fchain flags that might prevent final cleanup
1478 	 * of these chains.
1479 	 */
1480 	if (hmp->vchain.flags & HAMMER2_CHAIN_MODIFIED) {
1481 		atomic_clear_int(&hmp->vchain.flags,
1482 				 HAMMER2_CHAIN_MODIFIED);
1483 		hammer2_pfs_memory_wakeup(hmp->vchain.pmp);
1484 		hammer2_chain_drop(&hmp->vchain);
1485 	}
1486 	if (hmp->vchain.flags & HAMMER2_CHAIN_UPDATE) {
1487 		atomic_clear_int(&hmp->vchain.flags,
1488 				 HAMMER2_CHAIN_UPDATE);
1489 		hammer2_chain_drop(&hmp->vchain);
1490 	}
1491 
1492 	if (hmp->fchain.flags & HAMMER2_CHAIN_MODIFIED) {
1493 		atomic_clear_int(&hmp->fchain.flags,
1494 				 HAMMER2_CHAIN_MODIFIED);
1495 		hammer2_pfs_memory_wakeup(hmp->fchain.pmp);
1496 		hammer2_chain_drop(&hmp->fchain);
1497 	}
1498 	if (hmp->fchain.flags & HAMMER2_CHAIN_UPDATE) {
1499 		atomic_clear_int(&hmp->fchain.flags,
1500 				 HAMMER2_CHAIN_UPDATE);
1501 		hammer2_chain_drop(&hmp->fchain);
1502 	}
1503 
1504 	/*
1505 	 * Final drop of embedded freemap root chain to
1506 	 * clean up fchain.core (fchain structure is not
1507 	 * flagged ALLOCATED so it is cleaned out and then
1508 	 * left to rot).
1509 	 */
1510 	hammer2_chain_drop(&hmp->fchain);
1511 
1512 	/*
1513 	 * Final drop of embedded volume root chain to clean
1514 	 * up vchain.core (vchain structure is not flagged
1515 	 * ALLOCATED so it is cleaned out and then left to
1516 	 * rot).
1517 	 */
1518 	dumpcnt = 50;
1519 	hammer2_dump_chain(&hmp->vchain, 0, &dumpcnt, 'v');
1520 	dumpcnt = 50;
1521 	hammer2_dump_chain(&hmp->fchain, 0, &dumpcnt, 'f');
1522 	hammer2_dev_unlock(hmp);
1523 	hammer2_chain_drop(&hmp->vchain);
1524 
1525 	hammer2_io_cleanup(hmp, &hmp->iotree);
1526 	if (hmp->iofree_count) {
1527 		kprintf("io_cleanup: %d I/O's left hanging\n",
1528 			hmp->iofree_count);
1529 	}
1530 
1531 	TAILQ_REMOVE(&hammer2_mntlist, hmp, mntentry);
1532 	kmalloc_destroy(&hmp->mchain);
1533 	kfree(hmp, M_HAMMER2);
1534 }
1535 
1536 static
1537 int
1538 hammer2_vfs_vget(struct mount *mp, struct vnode *dvp,
1539 	     ino_t ino, struct vnode **vpp)
1540 {
1541 	kprintf("hammer2_vget\n");
1542 	return (EOPNOTSUPP);
1543 }
1544 
1545 static
1546 int
1547 hammer2_vfs_root(struct mount *mp, struct vnode **vpp)
1548 {
1549 	hammer2_pfs_t *pmp;
1550 	int error;
1551 	struct vnode *vp;
1552 
1553 	pmp = MPTOPMP(mp);
1554 	if (pmp->iroot == NULL) {
1555 		*vpp = NULL;
1556 		return EINVAL;
1557 	}
1558 
1559 	error = 0;
1560 	hammer2_inode_lock(pmp->iroot, HAMMER2_RESOLVE_SHARED);
1561 
1562 	while (pmp->inode_tid == 0) {
1563 		hammer2_xop_ipcluster_t *xop;
1564 		hammer2_inode_meta_t *meta;
1565 
1566 		xop = hammer2_xop_alloc(pmp->iroot, HAMMER2_XOP_MODIFYING);
1567 		hammer2_xop_start(&xop->head, hammer2_xop_ipcluster);
1568 		error = hammer2_xop_collect(&xop->head, 0);
1569 
1570 		if (error == 0) {
1571 			meta = &xop->head.cluster.focus->data->ipdata.meta;
1572 			pmp->iroot->meta = *meta;
1573 			pmp->inode_tid = meta->pfs_inum + 1;
1574 			if (pmp->inode_tid < HAMMER2_INODE_START)
1575 				pmp->inode_tid = HAMMER2_INODE_START;
1576 			pmp->modify_tid =
1577 				xop->head.cluster.focus->bref.modify_tid + 1;
1578 			kprintf("PFS: Starting inode %jd\n",
1579 				(intmax_t)pmp->inode_tid);
1580 			kprintf("PMP focus good set nextino=%ld mod=%016jx\n",
1581 				pmp->inode_tid, pmp->modify_tid);
1582 			wakeup(&pmp->iroot);
1583 
1584 			hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
1585 
1586 			/*
1587 			 * Prime the mount info.
1588 			 */
1589 			hammer2_vfs_statfs(mp, &mp->mnt_stat, NULL);
1590 
1591 			/*
1592 			 * With the cluster operational, check for and
1593 			 * install ihidden if needed.  The install_hidden
1594 			 * code needs to get a transaction so we must unlock
1595 			 * iroot around it.
1596 			 *
1597 			 * This is only applicable PFS mounts, there is no
1598 			 * hidden directory in the spmp.
1599 			 */
1600 			hammer2_inode_unlock(pmp->iroot);
1601 			hammer2_inode_install_hidden(pmp);
1602 			hammer2_inode_lock(pmp->iroot, HAMMER2_RESOLVE_SHARED);
1603 
1604 			break;
1605 		}
1606 
1607 		/*
1608 		 * Loop, try again
1609 		 */
1610 		hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
1611 		hammer2_inode_unlock(pmp->iroot);
1612 		error = tsleep(&pmp->iroot, PCATCH, "h2root", hz);
1613 		hammer2_inode_lock(pmp->iroot, HAMMER2_RESOLVE_SHARED);
1614 		if (error == EINTR)
1615 			break;
1616 	}
1617 
1618 	if (error) {
1619 		hammer2_inode_unlock(pmp->iroot);
1620 		*vpp = NULL;
1621 	} else {
1622 		vp = hammer2_igetv(pmp->iroot, &error);
1623 		hammer2_inode_unlock(pmp->iroot);
1624 		*vpp = vp;
1625 	}
1626 
1627 	return (error);
1628 }
1629 
1630 /*
1631  * Filesystem status
1632  *
1633  * XXX incorporate ipdata->meta.inode_quota and data_quota
1634  */
1635 static
1636 int
1637 hammer2_vfs_statfs(struct mount *mp, struct statfs *sbp, struct ucred *cred)
1638 {
1639 	hammer2_pfs_t *pmp;
1640 	hammer2_dev_t *hmp;
1641 	hammer2_blockref_t bref;
1642 	int i;
1643 
1644 	/*
1645 	 * NOTE: iroot might not have validated the cluster yet.
1646 	 */
1647 	pmp = MPTOPMP(mp);
1648 
1649 	mp->mnt_stat.f_files = 0;
1650 	mp->mnt_stat.f_ffree = 0;
1651 	mp->mnt_stat.f_blocks = 0;
1652 	mp->mnt_stat.f_bfree = 0;
1653 	mp->mnt_stat.f_bavail = 0;
1654 
1655 	for (i = 0; i < pmp->iroot->cluster.nchains; ++i) {
1656 		hmp = pmp->pfs_hmps[i];
1657 		if (hmp == NULL)
1658 			continue;
1659 		if (pmp->iroot->cluster.array[i].chain)
1660 			bref = pmp->iroot->cluster.array[i].chain->bref;
1661 		else
1662 			bzero(&bref, sizeof(bref));
1663 
1664 		mp->mnt_stat.f_files = bref.inode_count;
1665 		mp->mnt_stat.f_ffree = 0;
1666 		mp->mnt_stat.f_blocks = (bref.data_count +
1667 					 hmp->voldata.allocator_free) /
1668 					mp->mnt_vstat.f_bsize;
1669 		mp->mnt_stat.f_bfree =  hmp->voldata.allocator_free /
1670 					mp->mnt_vstat.f_bsize;
1671 		mp->mnt_stat.f_bavail = mp->mnt_stat.f_bfree;
1672 
1673 		*sbp = mp->mnt_stat;
1674 	}
1675 	return (0);
1676 }
1677 
1678 static
1679 int
1680 hammer2_vfs_statvfs(struct mount *mp, struct statvfs *sbp, struct ucred *cred)
1681 {
1682 	hammer2_pfs_t *pmp;
1683 	hammer2_dev_t *hmp;
1684 	hammer2_blockref_t bref;
1685 	int i;
1686 
1687 	/*
1688 	 * NOTE: iroot might not have validated the cluster yet.
1689 	 */
1690 	pmp = MPTOPMP(mp);
1691 
1692 	mp->mnt_vstat.f_bsize = 0;
1693 	mp->mnt_vstat.f_files = 0;
1694 	mp->mnt_vstat.f_ffree = 0;
1695 	mp->mnt_vstat.f_blocks = 0;
1696 	mp->mnt_vstat.f_bfree = 0;
1697 	mp->mnt_vstat.f_bavail = 0;
1698 
1699 	for (i = 0; i < pmp->iroot->cluster.nchains; ++i) {
1700 		hmp = pmp->pfs_hmps[i];
1701 		if (hmp == NULL)
1702 			continue;
1703 		if (pmp->iroot->cluster.array[i].chain)
1704 			bref = pmp->iroot->cluster.array[i].chain->bref;
1705 		else
1706 			bzero(&bref, sizeof(bref));
1707 
1708 		mp->mnt_vstat.f_bsize = HAMMER2_PBUFSIZE;
1709 		mp->mnt_vstat.f_files = bref.inode_count;
1710 		mp->mnt_vstat.f_ffree = 0;
1711 		mp->mnt_vstat.f_blocks = (bref.data_count +
1712 					 hmp->voldata.allocator_free) /
1713 					mp->mnt_vstat.f_bsize;
1714 		mp->mnt_vstat.f_bfree = hmp->voldata.allocator_free /
1715 					mp->mnt_vstat.f_bsize;
1716 		mp->mnt_vstat.f_bavail = mp->mnt_vstat.f_bfree;
1717 
1718 		*sbp = mp->mnt_vstat;
1719 	}
1720 	return (0);
1721 }
1722 
1723 /*
1724  * Mount-time recovery (RW mounts)
1725  *
1726  * Updates to the free block table are allowed to lag flushes by one
1727  * transaction.  In case of a crash, then on a fresh mount we must do an
1728  * incremental scan of the last committed transaction id and make sure that
1729  * all related blocks have been marked allocated.
1730  *
1731  * The super-root topology and each PFS has its own transaction id domain,
1732  * so we must track PFS boundary transitions.
1733  */
1734 struct hammer2_recovery_elm {
1735 	TAILQ_ENTRY(hammer2_recovery_elm) entry;
1736 	hammer2_chain_t *chain;
1737 	hammer2_tid_t sync_tid;
1738 };
1739 
1740 TAILQ_HEAD(hammer2_recovery_list, hammer2_recovery_elm);
1741 
1742 struct hammer2_recovery_info {
1743 	struct hammer2_recovery_list list;
1744 	hammer2_tid_t	mtid;
1745 	int	depth;
1746 };
1747 
1748 static int hammer2_recovery_scan(hammer2_dev_t *hmp,
1749 			hammer2_chain_t *parent,
1750 			struct hammer2_recovery_info *info,
1751 			hammer2_tid_t sync_tid);
1752 
1753 #define HAMMER2_RECOVERY_MAXDEPTH	10
1754 
1755 static
1756 int
1757 hammer2_recovery(hammer2_dev_t *hmp)
1758 {
1759 	struct hammer2_recovery_info info;
1760 	struct hammer2_recovery_elm *elm;
1761 	hammer2_chain_t *parent;
1762 	hammer2_tid_t sync_tid;
1763 	hammer2_tid_t mirror_tid;
1764 	int error;
1765 	int cumulative_error = 0;
1766 
1767 	hammer2_trans_init(hmp->spmp, 0);
1768 
1769 	sync_tid = hmp->voldata.freemap_tid;
1770 	mirror_tid = hmp->voldata.mirror_tid;
1771 
1772 	kprintf("hammer2 mount \"%s\": ", hmp->devrepname);
1773 	if (sync_tid >= mirror_tid) {
1774 		kprintf(" no recovery needed\n");
1775 	} else {
1776 		kprintf(" freemap recovery %016jx-%016jx\n",
1777 			sync_tid + 1, mirror_tid);
1778 	}
1779 
1780 	TAILQ_INIT(&info.list);
1781 	info.depth = 0;
1782 	parent = hammer2_chain_lookup_init(&hmp->vchain, 0);
1783 	cumulative_error = hammer2_recovery_scan(hmp, parent, &info, sync_tid);
1784 	hammer2_chain_lookup_done(parent);
1785 
1786 	while ((elm = TAILQ_FIRST(&info.list)) != NULL) {
1787 		TAILQ_REMOVE(&info.list, elm, entry);
1788 		parent = elm->chain;
1789 		sync_tid = elm->sync_tid;
1790 		kfree(elm, M_HAMMER2);
1791 
1792 		hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS);
1793 		error = hammer2_recovery_scan(hmp, parent, &info,
1794 					      hmp->voldata.freemap_tid);
1795 		hammer2_chain_unlock(parent);
1796 		hammer2_chain_drop(parent);	/* drop elm->chain ref */
1797 		if (error)
1798 			cumulative_error = error;
1799 	}
1800 	hammer2_trans_done(hmp->spmp);
1801 
1802 	return cumulative_error;
1803 }
1804 
1805 static
1806 int
1807 hammer2_recovery_scan(hammer2_dev_t *hmp, hammer2_chain_t *parent,
1808 		      struct hammer2_recovery_info *info,
1809 		      hammer2_tid_t sync_tid)
1810 {
1811 	const hammer2_inode_data_t *ripdata;
1812 	hammer2_chain_t *chain;
1813 	hammer2_blockref_t bref;
1814 	int cache_index;
1815 	int cumulative_error = 0;
1816 	int error;
1817 	int first;
1818 
1819 	/*
1820 	 * Adjust freemap to ensure that the block(s) are marked allocated.
1821 	 */
1822 	if (parent->bref.type != HAMMER2_BREF_TYPE_VOLUME) {
1823 		hammer2_freemap_adjust(hmp, &parent->bref,
1824 				       HAMMER2_FREEMAP_DORECOVER);
1825 	}
1826 
1827 	/*
1828 	 * Check type for recursive scan
1829 	 */
1830 	switch(parent->bref.type) {
1831 	case HAMMER2_BREF_TYPE_VOLUME:
1832 		/* data already instantiated */
1833 		break;
1834 	case HAMMER2_BREF_TYPE_INODE:
1835 		/*
1836 		 * Must instantiate data for DIRECTDATA test and also
1837 		 * for recursion.
1838 		 */
1839 		hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS);
1840 		ripdata = &hammer2_chain_rdata(parent)->ipdata;
1841 		if (ripdata->meta.op_flags & HAMMER2_OPFLAG_DIRECTDATA) {
1842 			/* not applicable to recovery scan */
1843 			hammer2_chain_unlock(parent);
1844 			return 0;
1845 		}
1846 		hammer2_chain_unlock(parent);
1847 		break;
1848 	case HAMMER2_BREF_TYPE_INDIRECT:
1849 		/*
1850 		 * Must instantiate data for recursion
1851 		 */
1852 		hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS);
1853 		hammer2_chain_unlock(parent);
1854 		break;
1855 	case HAMMER2_BREF_TYPE_DATA:
1856 	case HAMMER2_BREF_TYPE_FREEMAP:
1857 	case HAMMER2_BREF_TYPE_FREEMAP_NODE:
1858 	case HAMMER2_BREF_TYPE_FREEMAP_LEAF:
1859 		/* not applicable to recovery scan */
1860 		return 0;
1861 		break;
1862 	default:
1863 		return EDOM;
1864 	}
1865 
1866 	/*
1867 	 * Defer operation if depth limit reached or if we are crossing a
1868 	 * PFS boundary.
1869 	 */
1870 	if (info->depth >= HAMMER2_RECOVERY_MAXDEPTH) {
1871 		struct hammer2_recovery_elm *elm;
1872 
1873 		elm = kmalloc(sizeof(*elm), M_HAMMER2, M_ZERO | M_WAITOK);
1874 		elm->chain = parent;
1875 		elm->sync_tid = sync_tid;
1876 		hammer2_chain_ref(parent);
1877 		TAILQ_INSERT_TAIL(&info->list, elm, entry);
1878 		/* unlocked by caller */
1879 
1880 		return(0);
1881 	}
1882 
1883 
1884 	/*
1885 	 * Recursive scan of the last flushed transaction only.  We are
1886 	 * doing this without pmp assignments so don't leave the chains
1887 	 * hanging around after we are done with them.
1888 	 */
1889 	cache_index = 0;
1890 	chain = NULL;
1891 	first = 1;
1892 
1893 	while (hammer2_chain_scan(parent, &chain, &bref,
1894 				  &first, &cache_index,
1895 				  HAMMER2_LOOKUP_NODATA) != NULL) {
1896 		/*
1897 		 * If this is a leaf
1898 		 */
1899 		if (chain == NULL) {
1900 			if (bref.mirror_tid > sync_tid) {
1901 				hammer2_freemap_adjust(hmp, &bref,
1902 						     HAMMER2_FREEMAP_DORECOVER);
1903 			}
1904 			continue;
1905 		}
1906 
1907 		/*
1908 		 * This may or may not be a recursive node.
1909 		 */
1910 		atomic_set_int(&chain->flags, HAMMER2_CHAIN_RELEASE);
1911 		if (bref.mirror_tid > sync_tid) {
1912 			++info->depth;
1913 			error = hammer2_recovery_scan(hmp, chain,
1914 						      info, sync_tid);
1915 			--info->depth;
1916 			if (error)
1917 				cumulative_error = error;
1918 		}
1919 
1920 		/*
1921 		 * Flush the recovery at the PFS boundary to stage it for
1922 		 * the final flush of the super-root topology.
1923 		 */
1924 		if ((bref.flags & HAMMER2_BREF_FLAG_PFSROOT) &&
1925 		    (chain->flags & HAMMER2_CHAIN_ONFLUSH)) {
1926 			hammer2_flush(chain, HAMMER2_FLUSH_TOP);
1927 		}
1928 	}
1929 
1930 	return cumulative_error;
1931 }
1932 
1933 /*
1934  * Sync a mount point; this is called on a per-mount basis from the
1935  * filesystem syncer process periodically and whenever a user issues
1936  * a sync.
1937  */
1938 int
1939 hammer2_vfs_sync(struct mount *mp, int waitfor)
1940 {
1941 	hammer2_xop_flush_t *xop;
1942 	struct hammer2_sync_info info;
1943 	hammer2_inode_t *iroot;
1944 	hammer2_pfs_t *pmp;
1945 	int flags;
1946 	int error;
1947 
1948 	pmp = MPTOPMP(mp);
1949 	iroot = pmp->iroot;
1950 	KKASSERT(iroot);
1951 	KKASSERT(iroot->pmp == pmp);
1952 
1953 	/*
1954 	 * We can't acquire locks on existing vnodes while in a transaction
1955 	 * without risking a deadlock.  This assumes that vfsync() can be
1956 	 * called without the vnode locked (which it can in DragonFly).
1957 	 * Otherwise we'd have to implement a multi-pass or flag the lock
1958 	 * failures and retry.
1959 	 *
1960 	 * The reclamation code interlocks with the sync list's token
1961 	 * (by removing the vnode from the scan list) before unlocking
1962 	 * the inode, giving us time to ref the inode.
1963 	 */
1964 	/*flags = VMSC_GETVP;*/
1965 	flags = 0;
1966 	if (waitfor & MNT_LAZY)
1967 		flags |= VMSC_ONEPASS;
1968 
1969 #if 0
1970 	/*
1971 	 * Preflush the vnodes using a normal transaction before interlocking
1972 	 * with a flush transaction.
1973 	 */
1974 	hammer2_trans_init(pmp, 0);
1975 	info.error = 0;
1976 	info.waitfor = MNT_NOWAIT;
1977 	vsyncscan(mp, flags | VMSC_NOWAIT, hammer2_sync_scan2, &info);
1978 	hammer2_trans_done(pmp);
1979 #endif
1980 
1981 	/*
1982 	 * Start our flush transaction.  This does not return until all
1983 	 * concurrent transactions have completed and will prevent any
1984 	 * new transactions from running concurrently, except for the
1985 	 * buffer cache transactions.
1986 	 *
1987 	 * For efficiency do an async pass before making sure with a
1988 	 * synchronous pass on all related buffer cache buffers.  It
1989 	 * should theoretically not be possible for any new file buffers
1990 	 * to be instantiated during this sequence.
1991 	 */
1992 	hammer2_trans_init(pmp, HAMMER2_TRANS_ISFLUSH |
1993 			        HAMMER2_TRANS_PREFLUSH);
1994 	hammer2_inode_run_sideq(pmp);
1995 
1996 	info.error = 0;
1997 	info.waitfor = MNT_NOWAIT;
1998 	vsyncscan(mp, flags | VMSC_NOWAIT, hammer2_sync_scan2, &info);
1999 	info.waitfor = MNT_WAIT;
2000 	vsyncscan(mp, flags, hammer2_sync_scan2, &info);
2001 
2002 	/*
2003 	 * Clear PREFLUSH.  This prevents (or asserts on) any new logical
2004 	 * buffer cache flushes which occur during the flush.  Device buffers
2005 	 * are not affected.
2006 	 */
2007 	hammer2_bioq_sync(pmp);
2008 	hammer2_trans_clear_preflush(pmp);
2009 
2010 	/*
2011 	 * Use the XOP interface to concurrently flush all nodes to
2012 	 * synchronize the PFSROOT subtopology to the media.  A standard
2013 	 * end-of-scan ENOENT error indicates cluster sufficiency.
2014 	 *
2015 	 * Note that this flush will not be visible on crash recovery until
2016 	 * we flush the super-root topology in the next loop.
2017 	 *
2018 	 * XXX For now wait for all flushes to complete.
2019 	 */
2020 	if (iroot) {
2021 		xop = hammer2_xop_alloc(iroot, HAMMER2_XOP_MODIFYING);
2022 		hammer2_xop_start(&xop->head, hammer2_inode_xop_flush);
2023 		error = hammer2_xop_collect(&xop->head,
2024 					    HAMMER2_XOP_COLLECT_WAITALL);
2025 		hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
2026 		if (error == ENOENT)
2027 			error = 0;
2028 	} else {
2029 		error = 0;
2030 	}
2031 	hammer2_trans_done(pmp);
2032 
2033 	return (error);
2034 }
2035 
2036 /*
2037  * Sync passes.
2038  *
2039  * Note that we ignore the tranasction mtid we got above.  Instead,
2040  * each vfsync below will ultimately get its own via TRANS_BUFCACHE
2041  * transactions.
2042  */
2043 static int
2044 hammer2_sync_scan2(struct mount *mp, struct vnode *vp, void *data)
2045 {
2046 	struct hammer2_sync_info *info = data;
2047 	hammer2_inode_t *ip;
2048 	int error;
2049 
2050 	/*
2051 	 * Degenerate cases.  Note that ip == NULL typically means the
2052 	 * syncer vnode itself and we don't want to vclrisdirty() in that
2053 	 * situation.
2054 	 */
2055 	ip = VTOI(vp);
2056 	if (ip == NULL) {
2057 		return(0);
2058 	}
2059 	if (vp->v_type == VNON || vp->v_type == VBAD) {
2060 		vclrisdirty(vp);
2061 		return(0);
2062 	}
2063 
2064 	/*
2065 	 * VOP_FSYNC will start a new transaction so replicate some code
2066 	 * here to do it inline (see hammer2_vop_fsync()).
2067 	 *
2068 	 * WARNING: The vfsync interacts with the buffer cache and might
2069 	 *          block, we can't hold the inode lock at that time.
2070 	 *	    However, we MUST ref ip before blocking to ensure that
2071 	 *	    it isn't ripped out from under us (since we do not
2072 	 *	    hold a lock on the vnode).
2073 	 */
2074 	hammer2_inode_ref(ip);
2075 	if ((ip->flags & HAMMER2_INODE_MODIFIED) ||
2076 	    !RB_EMPTY(&vp->v_rbdirty_tree)) {
2077 		vfsync(vp, info->waitfor, 1, NULL, NULL);
2078 		if (ip->flags & (HAMMER2_INODE_RESIZED |
2079 				 HAMMER2_INODE_MODIFIED)) {
2080 			hammer2_inode_lock(ip, 0);
2081 			hammer2_inode_chain_sync(ip);
2082 			hammer2_inode_unlock(ip);
2083 		}
2084 	}
2085 	if ((ip->flags & HAMMER2_INODE_MODIFIED) == 0 &&
2086 	    RB_EMPTY(&vp->v_rbdirty_tree)) {
2087 		vclrisdirty(vp);
2088 	}
2089 
2090 	hammer2_inode_drop(ip);
2091 #if 1
2092 	error = 0;
2093 	if (error)
2094 		info->error = error;
2095 #endif
2096 	return(0);
2097 }
2098 
2099 static
2100 int
2101 hammer2_vfs_vptofh(struct vnode *vp, struct fid *fhp)
2102 {
2103 	return (0);
2104 }
2105 
2106 static
2107 int
2108 hammer2_vfs_fhtovp(struct mount *mp, struct vnode *rootvp,
2109 	       struct fid *fhp, struct vnode **vpp)
2110 {
2111 	return (0);
2112 }
2113 
2114 static
2115 int
2116 hammer2_vfs_checkexp(struct mount *mp, struct sockaddr *nam,
2117 		 int *exflagsp, struct ucred **credanonp)
2118 {
2119 	return (0);
2120 }
2121 
2122 /*
2123  * Support code for hammer2_vfs_mount().  Read, verify, and install the volume
2124  * header into the HMP
2125  *
2126  * XXX read four volhdrs and use the one with the highest TID whos CRC
2127  *     matches.
2128  *
2129  * XXX check iCRCs.
2130  *
2131  * XXX For filesystems w/ less than 4 volhdrs, make sure to not write to
2132  *     nonexistant locations.
2133  *
2134  * XXX Record selected volhdr and ring updates to each of 4 volhdrs
2135  */
2136 static
2137 int
2138 hammer2_install_volume_header(hammer2_dev_t *hmp)
2139 {
2140 	hammer2_volume_data_t *vd;
2141 	struct buf *bp;
2142 	hammer2_crc32_t crc0, crc, bcrc0, bcrc;
2143 	int error_reported;
2144 	int error;
2145 	int valid;
2146 	int i;
2147 
2148 	error_reported = 0;
2149 	error = 0;
2150 	valid = 0;
2151 	bp = NULL;
2152 
2153 	/*
2154 	 * There are up to 4 copies of the volume header (syncs iterate
2155 	 * between them so there is no single master).  We don't trust the
2156 	 * volu_size field so we don't know precisely how large the filesystem
2157 	 * is, so depend on the OS to return an error if we go beyond the
2158 	 * block device's EOF.
2159 	 */
2160 	for (i = 0; i < HAMMER2_NUM_VOLHDRS; i++) {
2161 		error = bread(hmp->devvp, i * HAMMER2_ZONE_BYTES64,
2162 			      HAMMER2_VOLUME_BYTES, &bp);
2163 		if (error) {
2164 			brelse(bp);
2165 			bp = NULL;
2166 			continue;
2167 		}
2168 
2169 		vd = (struct hammer2_volume_data *) bp->b_data;
2170 		if ((vd->magic != HAMMER2_VOLUME_ID_HBO) &&
2171 		    (vd->magic != HAMMER2_VOLUME_ID_ABO)) {
2172 			brelse(bp);
2173 			bp = NULL;
2174 			continue;
2175 		}
2176 
2177 		if (vd->magic == HAMMER2_VOLUME_ID_ABO) {
2178 			/* XXX: Reversed-endianness filesystem */
2179 			kprintf("hammer2: reverse-endian filesystem detected");
2180 			brelse(bp);
2181 			bp = NULL;
2182 			continue;
2183 		}
2184 
2185 		crc = vd->icrc_sects[HAMMER2_VOL_ICRC_SECT0];
2186 		crc0 = hammer2_icrc32(bp->b_data + HAMMER2_VOLUME_ICRC0_OFF,
2187 				      HAMMER2_VOLUME_ICRC0_SIZE);
2188 		bcrc = vd->icrc_sects[HAMMER2_VOL_ICRC_SECT1];
2189 		bcrc0 = hammer2_icrc32(bp->b_data + HAMMER2_VOLUME_ICRC1_OFF,
2190 				       HAMMER2_VOLUME_ICRC1_SIZE);
2191 		if ((crc0 != crc) || (bcrc0 != bcrc)) {
2192 			kprintf("hammer2 volume header crc "
2193 				"mismatch copy #%d %08x/%08x\n",
2194 				i, crc0, crc);
2195 			error_reported = 1;
2196 			brelse(bp);
2197 			bp = NULL;
2198 			continue;
2199 		}
2200 		if (valid == 0 || hmp->voldata.mirror_tid < vd->mirror_tid) {
2201 			valid = 1;
2202 			hmp->voldata = *vd;
2203 			hmp->volhdrno = i;
2204 		}
2205 		brelse(bp);
2206 		bp = NULL;
2207 	}
2208 	if (valid) {
2209 		hmp->volsync = hmp->voldata;
2210 		error = 0;
2211 		if (error_reported || bootverbose || 1) { /* 1/DEBUG */
2212 			kprintf("hammer2: using volume header #%d\n",
2213 				hmp->volhdrno);
2214 		}
2215 	} else {
2216 		error = EINVAL;
2217 		kprintf("hammer2: no valid volume headers found!\n");
2218 	}
2219 	return (error);
2220 }
2221 
2222 /*
2223  * This handles hysteresis on regular file flushes.  Because the BIOs are
2224  * routed to a thread it is possible for an excessive number to build up
2225  * and cause long front-end stalls long before the runningbuffspace limit
2226  * is hit, so we implement hammer2_flush_pipe to control the
2227  * hysteresis.
2228  *
2229  * This is a particular problem when compression is used.
2230  */
2231 void
2232 hammer2_lwinprog_ref(hammer2_pfs_t *pmp)
2233 {
2234 	atomic_add_int(&pmp->count_lwinprog, 1);
2235 }
2236 
2237 void
2238 hammer2_lwinprog_drop(hammer2_pfs_t *pmp)
2239 {
2240 	int lwinprog;
2241 
2242 	lwinprog = atomic_fetchadd_int(&pmp->count_lwinprog, -1);
2243 	if ((lwinprog & HAMMER2_LWINPROG_WAITING) &&
2244 	    (lwinprog & HAMMER2_LWINPROG_MASK) <= hammer2_flush_pipe * 2 / 3) {
2245 		atomic_clear_int(&pmp->count_lwinprog,
2246 				 HAMMER2_LWINPROG_WAITING);
2247 		wakeup(&pmp->count_lwinprog);
2248 	}
2249 	if ((lwinprog & HAMMER2_LWINPROG_WAITING0) &&
2250 	    (lwinprog & HAMMER2_LWINPROG_MASK) <= 0) {
2251 		atomic_clear_int(&pmp->count_lwinprog,
2252 				 HAMMER2_LWINPROG_WAITING0);
2253 		wakeup(&pmp->count_lwinprog);
2254 	}
2255 }
2256 
2257 void
2258 hammer2_lwinprog_wait(hammer2_pfs_t *pmp, int flush_pipe)
2259 {
2260 	int lwinprog;
2261 	int lwflag = (flush_pipe) ? HAMMER2_LWINPROG_WAITING :
2262 				    HAMMER2_LWINPROG_WAITING0;
2263 
2264 	for (;;) {
2265 		lwinprog = pmp->count_lwinprog;
2266 		cpu_ccfence();
2267 		if ((lwinprog & HAMMER2_LWINPROG_MASK) <= flush_pipe)
2268 			break;
2269 		tsleep_interlock(&pmp->count_lwinprog, 0);
2270 		atomic_set_int(&pmp->count_lwinprog, lwflag);
2271 		lwinprog = pmp->count_lwinprog;
2272 		if ((lwinprog & HAMMER2_LWINPROG_MASK) <= flush_pipe)
2273 			break;
2274 		tsleep(&pmp->count_lwinprog, PINTERLOCKED, "h2wpipe", hz);
2275 	}
2276 }
2277 
2278 /*
2279  * Manage excessive memory resource use for chain and related
2280  * structures.
2281  */
2282 void
2283 hammer2_pfs_memory_wait(hammer2_pfs_t *pmp)
2284 {
2285 	uint32_t waiting;
2286 	uint32_t count;
2287 	uint32_t limit;
2288 #if 0
2289 	static int zzticks;
2290 #endif
2291 
2292 	/*
2293 	 * Atomic check condition and wait.  Also do an early speedup of
2294 	 * the syncer to try to avoid hitting the wait.
2295 	 */
2296 	for (;;) {
2297 		waiting = pmp->inmem_dirty_chains;
2298 		cpu_ccfence();
2299 		count = waiting & HAMMER2_DIRTYCHAIN_MASK;
2300 
2301 		limit = pmp->mp->mnt_nvnodelistsize / 10;
2302 		if (limit < hammer2_limit_dirty_chains)
2303 			limit = hammer2_limit_dirty_chains;
2304 		if (limit < 1000)
2305 			limit = 1000;
2306 
2307 #if 0
2308 		if ((int)(ticks - zzticks) > hz) {
2309 			zzticks = ticks;
2310 			kprintf("count %ld %ld\n", count, limit);
2311 		}
2312 #endif
2313 
2314 		/*
2315 		 * Block if there are too many dirty chains present, wait
2316 		 * for the flush to clean some out.
2317 		 */
2318 		if (count > limit) {
2319 			tsleep_interlock(&pmp->inmem_dirty_chains, 0);
2320 			if (atomic_cmpset_int(&pmp->inmem_dirty_chains,
2321 					       waiting,
2322 				       waiting | HAMMER2_DIRTYCHAIN_WAITING)) {
2323 				speedup_syncer(pmp->mp);
2324 				tsleep(&pmp->inmem_dirty_chains, PINTERLOCKED,
2325 				       "chnmem", hz);
2326 			}
2327 			continue;	/* loop on success or fail */
2328 		}
2329 
2330 		/*
2331 		 * Try to start an early flush before we are forced to block.
2332 		 */
2333 		if (count > limit * 7 / 10)
2334 			speedup_syncer(pmp->mp);
2335 		break;
2336 	}
2337 }
2338 
2339 void
2340 hammer2_pfs_memory_inc(hammer2_pfs_t *pmp)
2341 {
2342 	if (pmp) {
2343 		atomic_add_int(&pmp->inmem_dirty_chains, 1);
2344 	}
2345 }
2346 
2347 void
2348 hammer2_pfs_memory_wakeup(hammer2_pfs_t *pmp)
2349 {
2350 	uint32_t waiting;
2351 
2352 	if (pmp == NULL)
2353 		return;
2354 
2355 	for (;;) {
2356 		waiting = pmp->inmem_dirty_chains;
2357 		cpu_ccfence();
2358 		if (atomic_cmpset_int(&pmp->inmem_dirty_chains,
2359 				       waiting,
2360 				       (waiting - 1) &
2361 					~HAMMER2_DIRTYCHAIN_WAITING)) {
2362 			break;
2363 		}
2364 	}
2365 
2366 	if (waiting & HAMMER2_DIRTYCHAIN_WAITING)
2367 		wakeup(&pmp->inmem_dirty_chains);
2368 }
2369 
2370 /*
2371  * Debugging
2372  */
2373 void
2374 hammer2_dump_chain(hammer2_chain_t *chain, int tab, int *countp, char pfx)
2375 {
2376 	hammer2_chain_t *scan;
2377 	hammer2_chain_t *parent;
2378 
2379 	--*countp;
2380 	if (*countp == 0) {
2381 		kprintf("%*.*s...\n", tab, tab, "");
2382 		return;
2383 	}
2384 	if (*countp < 0)
2385 		return;
2386 	kprintf("%*.*s%c-chain %p.%d %016jx/%d mir=%016jx\n",
2387 		tab, tab, "", pfx,
2388 		chain, chain->bref.type,
2389 		chain->bref.key, chain->bref.keybits,
2390 		chain->bref.mirror_tid);
2391 
2392 	kprintf("%*.*s      [%08x] (%s) refs=%d",
2393 		tab, tab, "",
2394 		chain->flags,
2395 		((chain->bref.type == HAMMER2_BREF_TYPE_INODE &&
2396 		chain->data) ?  (char *)chain->data->ipdata.filename : "?"),
2397 		chain->refs);
2398 
2399 	parent = chain->parent;
2400 	if (parent)
2401 		kprintf("\n%*.*s      p=%p [pflags %08x prefs %d",
2402 			tab, tab, "",
2403 			parent, parent->flags, parent->refs);
2404 	if (RB_EMPTY(&chain->core.rbtree)) {
2405 		kprintf("\n");
2406 	} else {
2407 		kprintf(" {\n");
2408 		RB_FOREACH(scan, hammer2_chain_tree, &chain->core.rbtree)
2409 			hammer2_dump_chain(scan, tab + 4, countp, 'a');
2410 		if (chain->bref.type == HAMMER2_BREF_TYPE_INODE && chain->data)
2411 			kprintf("%*.*s}(%s)\n", tab, tab, "",
2412 				chain->data->ipdata.filename);
2413 		else
2414 			kprintf("%*.*s}\n", tab, tab, "");
2415 	}
2416 }
2417