xref: /dflybsd-src/sys/vfs/hammer2/hammer2_vfsops.c (revision aa6ac96e01825b3efcab953441f85adbf9815e0f)
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_meta_write;
94 long hammer2_iod_indr_write;
95 long hammer2_iod_fmap_write;
96 long hammer2_iod_volu_write;
97 long hammer2_ioa_file_read;
98 long hammer2_ioa_meta_read;
99 long hammer2_ioa_indr_read;
100 long hammer2_ioa_fmap_read;
101 long hammer2_ioa_volu_read;
102 long hammer2_ioa_fmap_write;
103 long hammer2_ioa_file_write;
104 long hammer2_ioa_meta_write;
105 long hammer2_ioa_indr_write;
106 long hammer2_ioa_volu_write;
107 
108 MALLOC_DECLARE(M_HAMMER2_CBUFFER);
109 MALLOC_DEFINE(M_HAMMER2_CBUFFER, "HAMMER2-compbuffer",
110 		"Buffer used for compression.");
111 
112 MALLOC_DECLARE(M_HAMMER2_DEBUFFER);
113 MALLOC_DEFINE(M_HAMMER2_DEBUFFER, "HAMMER2-decompbuffer",
114 		"Buffer used for decompression.");
115 
116 SYSCTL_NODE(_vfs, OID_AUTO, hammer2, CTLFLAG_RW, 0, "HAMMER2 filesystem");
117 
118 SYSCTL_INT(_vfs_hammer2, OID_AUTO, debug, CTLFLAG_RW,
119 	   &hammer2_debug, 0, "");
120 SYSCTL_INT(_vfs_hammer2, OID_AUTO, cluster_enable, CTLFLAG_RW,
121 	   &hammer2_cluster_enable, 0, "");
122 SYSCTL_INT(_vfs_hammer2, OID_AUTO, hardlink_enable, CTLFLAG_RW,
123 	   &hammer2_hardlink_enable, 0, "");
124 SYSCTL_INT(_vfs_hammer2, OID_AUTO, flush_pipe, CTLFLAG_RW,
125 	   &hammer2_flush_pipe, 0, "");
126 SYSCTL_INT(_vfs_hammer2, OID_AUTO, synchronous_flush, CTLFLAG_RW,
127 	   &hammer2_synchronous_flush, 0, "");
128 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, limit_dirty_chains, CTLFLAG_RW,
129 	   &hammer2_limit_dirty_chains, 0, "");
130 SYSCTL_INT(_vfs_hammer2, OID_AUTO, dio_count, CTLFLAG_RD,
131 	   &hammer2_dio_count, 0, "");
132 
133 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_file_read, CTLFLAG_RW,
134 	   &hammer2_iod_file_read, 0, "");
135 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_meta_read, CTLFLAG_RW,
136 	   &hammer2_iod_meta_read, 0, "");
137 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_indr_read, CTLFLAG_RW,
138 	   &hammer2_iod_indr_read, 0, "");
139 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_fmap_read, CTLFLAG_RW,
140 	   &hammer2_iod_fmap_read, 0, "");
141 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_volu_read, CTLFLAG_RW,
142 	   &hammer2_iod_volu_read, 0, "");
143 
144 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_file_write, CTLFLAG_RW,
145 	   &hammer2_iod_file_write, 0, "");
146 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_meta_write, CTLFLAG_RW,
147 	   &hammer2_iod_meta_write, 0, "");
148 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_indr_write, CTLFLAG_RW,
149 	   &hammer2_iod_indr_write, 0, "");
150 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_fmap_write, CTLFLAG_RW,
151 	   &hammer2_iod_fmap_write, 0, "");
152 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_volu_write, CTLFLAG_RW,
153 	   &hammer2_iod_volu_write, 0, "");
154 
155 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, ioa_file_read, CTLFLAG_RW,
156 	   &hammer2_ioa_file_read, 0, "");
157 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, ioa_meta_read, CTLFLAG_RW,
158 	   &hammer2_ioa_meta_read, 0, "");
159 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, ioa_indr_read, CTLFLAG_RW,
160 	   &hammer2_ioa_indr_read, 0, "");
161 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, ioa_fmap_read, CTLFLAG_RW,
162 	   &hammer2_ioa_fmap_read, 0, "");
163 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, ioa_volu_read, CTLFLAG_RW,
164 	   &hammer2_ioa_volu_read, 0, "");
165 
166 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, ioa_file_write, CTLFLAG_RW,
167 	   &hammer2_ioa_file_write, 0, "");
168 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, ioa_meta_write, CTLFLAG_RW,
169 	   &hammer2_ioa_meta_write, 0, "");
170 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, ioa_indr_write, CTLFLAG_RW,
171 	   &hammer2_ioa_indr_write, 0, "");
172 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, ioa_fmap_write, CTLFLAG_RW,
173 	   &hammer2_ioa_fmap_write, 0, "");
174 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, ioa_volu_write, CTLFLAG_RW,
175 	   &hammer2_ioa_volu_write, 0, "");
176 
177 static int hammer2_vfs_init(struct vfsconf *conf);
178 static int hammer2_vfs_uninit(struct vfsconf *vfsp);
179 static int hammer2_vfs_mount(struct mount *mp, char *path, caddr_t data,
180 				struct ucred *cred);
181 static int hammer2_remount(hammer2_dev_t *, struct mount *, char *,
182 				struct vnode *, struct ucred *);
183 static int hammer2_recovery(hammer2_dev_t *hmp);
184 static int hammer2_vfs_unmount(struct mount *mp, int mntflags);
185 static int hammer2_vfs_root(struct mount *mp, struct vnode **vpp);
186 static int hammer2_vfs_statfs(struct mount *mp, struct statfs *sbp,
187 				struct ucred *cred);
188 static int hammer2_vfs_statvfs(struct mount *mp, struct statvfs *sbp,
189 				struct ucred *cred);
190 static int hammer2_vfs_vget(struct mount *mp, struct vnode *dvp,
191 				ino_t ino, struct vnode **vpp);
192 static int hammer2_vfs_fhtovp(struct mount *mp, struct vnode *rootvp,
193 				struct fid *fhp, struct vnode **vpp);
194 static int hammer2_vfs_vptofh(struct vnode *vp, struct fid *fhp);
195 static int hammer2_vfs_checkexp(struct mount *mp, struct sockaddr *nam,
196 				int *exflagsp, struct ucred **credanonp);
197 
198 static int hammer2_install_volume_header(hammer2_dev_t *hmp);
199 static int hammer2_sync_scan2(struct mount *mp, struct vnode *vp, void *data);
200 
201 static void hammer2_update_pmps(hammer2_dev_t *hmp);
202 
203 static void hammer2_mount_helper(struct mount *mp, hammer2_pfs_t *pmp);
204 static void hammer2_unmount_helper(struct mount *mp, hammer2_pfs_t *pmp,
205 				hammer2_dev_t *hmp);
206 
207 /*
208  * HAMMER2 vfs operations.
209  */
210 static struct vfsops hammer2_vfsops = {
211 	.vfs_init	= hammer2_vfs_init,
212 	.vfs_uninit	= hammer2_vfs_uninit,
213 	.vfs_sync	= hammer2_vfs_sync,
214 	.vfs_mount	= hammer2_vfs_mount,
215 	.vfs_unmount	= hammer2_vfs_unmount,
216 	.vfs_root 	= hammer2_vfs_root,
217 	.vfs_statfs	= hammer2_vfs_statfs,
218 	.vfs_statvfs	= hammer2_vfs_statvfs,
219 	.vfs_vget	= hammer2_vfs_vget,
220 	.vfs_vptofh	= hammer2_vfs_vptofh,
221 	.vfs_fhtovp	= hammer2_vfs_fhtovp,
222 	.vfs_checkexp	= hammer2_vfs_checkexp
223 };
224 
225 MALLOC_DEFINE(M_HAMMER2, "HAMMER2-mount", "");
226 
227 VFS_SET(hammer2_vfsops, hammer2, 0);
228 MODULE_VERSION(hammer2, 1);
229 
230 static
231 int
232 hammer2_vfs_init(struct vfsconf *conf)
233 {
234 	static struct objcache_malloc_args margs_read;
235 	static struct objcache_malloc_args margs_write;
236 	static struct objcache_malloc_args margs_vop;
237 
238 	int error;
239 
240 	error = 0;
241 
242 	if (HAMMER2_BLOCKREF_BYTES != sizeof(struct hammer2_blockref))
243 		error = EINVAL;
244 	if (HAMMER2_INODE_BYTES != sizeof(struct hammer2_inode_data))
245 		error = EINVAL;
246 	if (HAMMER2_VOLUME_BYTES != sizeof(struct hammer2_volume_data))
247 		error = EINVAL;
248 
249 	if (error)
250 		kprintf("HAMMER2 structure size mismatch; cannot continue.\n");
251 
252 	margs_read.objsize = 65536;
253 	margs_read.mtype = M_HAMMER2_DEBUFFER;
254 
255 	margs_write.objsize = 32768;
256 	margs_write.mtype = M_HAMMER2_CBUFFER;
257 
258 	margs_vop.objsize = sizeof(hammer2_xop_t);
259 	margs_vop.mtype = M_HAMMER2;
260 
261 	/*
262 	 * Note thaht for the XOPS cache we want backing store allocations
263 	 * to use M_ZERO.  This is not allowed in objcache_get() (to avoid
264 	 * confusion), so use the backing store function that does it.  This
265 	 * means that initial XOPS objects are zerod but REUSED objects are
266 	 * not.  So we are responsible for cleaning the object up sufficiently
267 	 * for our needs before objcache_put()ing it back (typically just the
268 	 * FIFO indices).
269 	 */
270 	cache_buffer_read = objcache_create(margs_read.mtype->ks_shortdesc,
271 				0, 1, NULL, NULL, NULL,
272 				objcache_malloc_alloc,
273 				objcache_malloc_free,
274 				&margs_read);
275 	cache_buffer_write = objcache_create(margs_write.mtype->ks_shortdesc,
276 				0, 1, NULL, NULL, NULL,
277 				objcache_malloc_alloc,
278 				objcache_malloc_free,
279 				&margs_write);
280 	cache_xops = objcache_create(margs_vop.mtype->ks_shortdesc,
281 				0, 1, NULL, NULL, NULL,
282 				objcache_malloc_alloc_zero,
283 				objcache_malloc_free,
284 				&margs_vop);
285 
286 
287 	lockinit(&hammer2_mntlk, "mntlk", 0, 0);
288 	TAILQ_INIT(&hammer2_mntlist);
289 	TAILQ_INIT(&hammer2_pfslist);
290 
291 	hammer2_limit_dirty_chains = desiredvnodes / 10;
292 
293 	return (error);
294 }
295 
296 static
297 int
298 hammer2_vfs_uninit(struct vfsconf *vfsp __unused)
299 {
300 	objcache_destroy(cache_buffer_read);
301 	objcache_destroy(cache_buffer_write);
302 	objcache_destroy(cache_xops);
303 	return 0;
304 }
305 
306 /*
307  * Core PFS allocator.  Used to allocate the pmp structure for PFS cluster
308  * mounts and the spmp structure for media (hmp) structures.
309  *
310  * pmp->modify_tid tracks new modify_tid transaction ids for front-end
311  * transactions.  Note that synchronization does not use this field.
312  * (typically frontend operations and synchronization cannot run on the
313  * same PFS node at the same time).
314  *
315  * XXX check locking
316  */
317 hammer2_pfs_t *
318 hammer2_pfsalloc(hammer2_chain_t *chain, const hammer2_inode_data_t *ripdata,
319 		 hammer2_tid_t modify_tid)
320 {
321 	hammer2_inode_t *iroot;
322 	hammer2_pfs_t *pmp;
323 	int count;
324 	int i;
325 	int j;
326 
327 	/*
328 	 * Locate or create the PFS based on the cluster id.  If ripdata
329 	 * is NULL this is a spmp which is unique and is always allocated.
330 	 */
331 	if (ripdata) {
332 		TAILQ_FOREACH(pmp, &hammer2_pfslist, mntentry) {
333 			if (bcmp(&pmp->pfs_clid, &ripdata->meta.pfs_clid,
334 				 sizeof(pmp->pfs_clid)) == 0) {
335 					break;
336 			}
337 		}
338 	} else {
339 		pmp = NULL;
340 	}
341 
342 	if (pmp == NULL) {
343 		pmp = kmalloc(sizeof(*pmp), M_HAMMER2, M_WAITOK | M_ZERO);
344 		hammer2_trans_manage_init(pmp);
345 		kmalloc_create(&pmp->minode, "HAMMER2-inodes");
346 		kmalloc_create(&pmp->mmsg, "HAMMER2-pfsmsg");
347 		lockinit(&pmp->lock, "pfslk", 0, 0);
348 		spin_init(&pmp->inum_spin, "hm2pfsalloc_inum");
349 		spin_init(&pmp->xop_spin, "h2xop");
350 		RB_INIT(&pmp->inum_tree);
351 		TAILQ_INIT(&pmp->unlinkq);
352 		spin_init(&pmp->list_spin, "hm2pfsalloc_list");
353 
354 		/*
355 		 * Distribute backend operations to threads
356 		 */
357 		for (j = 0; j < HAMMER2_MAXCLUSTER; ++j)
358 			TAILQ_INIT(&pmp->xopq[j]);
359 		for (j = 0; j < HAMMER2_XOPGROUPS; ++j)
360 			hammer2_xop_group_init(pmp, &pmp->xop_groups[j]);
361 
362 		/*
363 		 * Save the last media transaction id for the flusher.  Set
364 		 * initial
365 		 */
366 		if (ripdata)
367 			pmp->pfs_clid = ripdata->meta.pfs_clid;
368 		TAILQ_INSERT_TAIL(&hammer2_pfslist, pmp, mntentry);
369 
370 		/*
371 		 * The synchronization thread may start too early, make
372 		 * sure it stays frozen until we are ready to let it go.
373 		 * XXX
374 		 */
375 		/*
376 		pmp->primary_thr.flags = HAMMER2_THREAD_FROZEN |
377 					 HAMMER2_THREAD_REMASTER;
378 		*/
379 	}
380 
381 	/*
382 	 * Create the PFS's root inode.
383 	 */
384 	if ((iroot = pmp->iroot) == NULL) {
385 		iroot = hammer2_inode_get(pmp, NULL, NULL, -1);
386 		pmp->iroot = iroot;
387 		hammer2_inode_ref(iroot);
388 		hammer2_inode_unlock(iroot);
389 	}
390 
391 	/*
392 	 * Stop here if no chain is passed in.
393 	 */
394 	if (chain == NULL)
395 		goto done;
396 
397 	/*
398 	 * When a chain is passed in we must add it to the PFS's root
399 	 * inode, update pmp->pfs_types[], and update the syncronization
400 	 * threads.
401 	 *
402 	 * At the moment empty spots can develop due to removals or failures.
403 	 * Ultimately we want to re-fill these spots but doing so might
404 	 * confused running code. XXX
405 	 */
406 	hammer2_inode_ref(iroot);
407 	hammer2_mtx_ex(&iroot->lock);
408 	j = iroot->cluster.nchains;
409 
410 	kprintf("add PFS to pmp %p[%d]\n", pmp, j);
411 
412 	if (j == HAMMER2_MAXCLUSTER) {
413 		kprintf("hammer2_mount: cluster full!\n");
414 		/* XXX fatal error? */
415 	} else {
416 		KKASSERT(chain->pmp == NULL);
417 		chain->pmp = pmp;
418 		hammer2_chain_ref(chain);
419 		iroot->cluster.array[j].chain = chain;
420 		pmp->pfs_types[j] = ripdata->meta.pfs_type;
421 		pmp->pfs_names[j] = kstrdup(ripdata->filename, M_HAMMER2);
422 		pmp->pfs_hmps[j] = chain->hmp;
423 
424 		/*
425 		 * If the PFS is already mounted we must account
426 		 * for the mount_count here.
427 		 */
428 		if (pmp->mp)
429 			++chain->hmp->mount_count;
430 
431 		/*
432 		 * May have to fixup dirty chain tracking.  Previous
433 		 * pmp was NULL so nothing to undo.
434 		 */
435 		if (chain->flags & HAMMER2_CHAIN_MODIFIED)
436 			hammer2_pfs_memory_inc(pmp);
437 		++j;
438 	}
439 	iroot->cluster.nchains = j;
440 
441 	/*
442 	 * Update nmasters from any PFS inode which is part of the cluster.
443 	 * It is possible that this will result in a value which is too
444 	 * high.  MASTER PFSs are authoritative for pfs_nmasters and will
445 	 * override this value later on.
446 	 *
447 	 * (This informs us of masters that might not currently be
448 	 *  discoverable by this mount).
449 	 */
450 	if (ripdata && pmp->pfs_nmasters < ripdata->meta.pfs_nmasters) {
451 		pmp->pfs_nmasters = ripdata->meta.pfs_nmasters;
452 	}
453 
454 	/*
455 	 * Count visible masters.  Masters are usually added with
456 	 * ripdata->meta.pfs_nmasters set to 1.  This detects when there
457 	 * are more (XXX and must update the master inodes).
458 	 */
459 	count = 0;
460 	for (i = 0; i < iroot->cluster.nchains; ++i) {
461 		if (pmp->pfs_types[i] == HAMMER2_PFSTYPE_MASTER)
462 			++count;
463 	}
464 	if (pmp->pfs_nmasters < count)
465 		pmp->pfs_nmasters = count;
466 
467 	/*
468 	 * Create missing synchronization and support threads.
469 	 *
470 	 * Single-node masters (including snapshots) have nothing to
471 	 * synchronize and do not require this thread.
472 	 *
473 	 * Multi-node masters or any number of soft masters, slaves, copy,
474 	 * or other PFS types need the thread.
475 	 *
476 	 * Each thread is responsible for its particular cluster index.
477 	 * We use independent threads so stalls or mismatches related to
478 	 * any given target do not affect other targets.
479 	 */
480 	for (i = 0; i < iroot->cluster.nchains; ++i) {
481 		/*
482 		 * Single-node masters (including snapshots) have nothing
483 		 * to synchronize and will make direct xops support calls,
484 		 * thus they do not require this thread.
485 		 *
486 		 * Note that there can be thousands of snapshots.  We do not
487 		 * want to create thousands of threads.
488 		 */
489 		if (pmp->pfs_nmasters <= 1 &&
490 		    pmp->pfs_types[i] == HAMMER2_PFSTYPE_MASTER) {
491 			continue;
492 		}
493 
494 		/*
495 		 * Sync support thread
496 		 */
497 		if (pmp->sync_thrs[i].td == NULL) {
498 			hammer2_thr_create(&pmp->sync_thrs[i], pmp,
499 					   "h2nod", i, -1,
500 					   hammer2_primary_sync_thread);
501 		}
502 	}
503 
504 	/*
505 	 * Create missing Xop threads
506 	 */
507 	if (pmp->mp)
508 		hammer2_xop_helper_create(pmp);
509 
510 	hammer2_mtx_unlock(&iroot->lock);
511 	hammer2_inode_drop(iroot);
512 done:
513 	return pmp;
514 }
515 
516 /*
517  * Destroy a PFS, typically only occurs after the last mount on a device
518  * has gone away.
519  */
520 static void
521 hammer2_pfsfree(hammer2_pfs_t *pmp)
522 {
523 	hammer2_inode_t *iroot;
524 	int i;
525 	int j;
526 
527 	/*
528 	 * Cleanup our reference on iroot.  iroot is (should) not be needed
529 	 * by the flush code.
530 	 */
531 	TAILQ_REMOVE(&hammer2_pfslist, pmp, mntentry);
532 
533 	iroot = pmp->iroot;
534 	if (iroot) {
535 		for (i = 0; i < iroot->cluster.nchains; ++i) {
536 			hammer2_thr_delete(&pmp->sync_thrs[i]);
537 			for (j = 0; j < HAMMER2_XOPGROUPS; ++j)
538 				hammer2_thr_delete(&pmp->xop_groups[j].thrs[i]);
539 		}
540 #if REPORT_REFS_ERRORS
541 		if (pmp->iroot->refs != 1)
542 			kprintf("PMP->IROOT %p REFS WRONG %d\n",
543 				pmp->iroot, pmp->iroot->refs);
544 #else
545 		KKASSERT(pmp->iroot->refs == 1);
546 #endif
547 		/* ref for pmp->iroot */
548 		hammer2_inode_drop(pmp->iroot);
549 		pmp->iroot = NULL;
550 	}
551 
552 	kmalloc_destroy(&pmp->mmsg);
553 	kmalloc_destroy(&pmp->minode);
554 
555 	kfree(pmp, M_HAMMER2);
556 }
557 
558 /*
559  * Remove all references to hmp from the pfs list.  Any PFS which becomes
560  * empty is terminated and freed.
561  *
562  * XXX inefficient.
563  */
564 static void
565 hammer2_pfsfree_scan(hammer2_dev_t *hmp)
566 {
567 	hammer2_pfs_t *pmp;
568 	hammer2_inode_t *iroot;
569 	hammer2_chain_t *rchain;
570 	int didfreeze;
571 	int i;
572 	int j;
573 
574 again:
575 	TAILQ_FOREACH(pmp, &hammer2_pfslist, mntentry) {
576 		if ((iroot = pmp->iroot) == NULL)
577 			continue;
578 		if (hmp->spmp == pmp) {
579 			kprintf("unmount hmp %p remove spmp %p\n",
580 				hmp, pmp);
581 			hmp->spmp = NULL;
582 		}
583 
584 		/*
585 		 * Determine if this PFS is affected.  If it is we must
586 		 * freeze all management threads and lock its iroot.
587 		 *
588 		 * Freezing a management thread forces it idle, operations
589 		 * in-progress will be aborted and it will have to start
590 		 * over again when unfrozen, or exit if told to exit.
591 		 */
592 		for (i = 0; i < HAMMER2_MAXCLUSTER; ++i) {
593 			if (pmp->pfs_hmps[i] == hmp)
594 				break;
595 		}
596 		if (i != HAMMER2_MAXCLUSTER) {
597 			/*
598 			 * Make sure all synchronization threads are locked
599 			 * down.
600 			 */
601 			for (i = 0; i < HAMMER2_MAXCLUSTER; ++i) {
602 				if (pmp->pfs_hmps[i] == NULL)
603 					continue;
604 				hammer2_thr_freeze_async(&pmp->sync_thrs[i]);
605 				for (j = 0; j < HAMMER2_XOPGROUPS; ++j) {
606 					hammer2_thr_freeze_async(
607 						&pmp->xop_groups[j].thrs[i]);
608 				}
609 			}
610 			for (i = 0; i < HAMMER2_MAXCLUSTER; ++i) {
611 				if (pmp->pfs_hmps[i] == NULL)
612 					continue;
613 				hammer2_thr_freeze(&pmp->sync_thrs[i]);
614 				for (j = 0; j < HAMMER2_XOPGROUPS; ++j) {
615 					hammer2_thr_freeze(
616 						&pmp->xop_groups[j].thrs[i]);
617 				}
618 			}
619 
620 			/*
621 			 * Lock the inode and clean out matching chains.
622 			 * Note that we cannot use hammer2_inode_lock_*()
623 			 * here because that would attempt to validate the
624 			 * cluster that we are in the middle of ripping
625 			 * apart.
626 			 *
627 			 * WARNING! We are working directly on the inodes
628 			 *	    embedded cluster.
629 			 */
630 			hammer2_mtx_ex(&iroot->lock);
631 
632 			/*
633 			 * Remove the chain from matching elements of the PFS.
634 			 */
635 			for (i = 0; i < HAMMER2_MAXCLUSTER; ++i) {
636 				if (pmp->pfs_hmps[i] != hmp)
637 					continue;
638 				hammer2_thr_delete(&pmp->sync_thrs[i]);
639 				for (j = 0; j < HAMMER2_XOPGROUPS; ++j) {
640 					hammer2_thr_delete(
641 						&pmp->xop_groups[j].thrs[i]);
642 				}
643 				rchain = iroot->cluster.array[i].chain;
644 				iroot->cluster.array[i].chain = NULL;
645 				pmp->pfs_types[i] = 0;
646 				if (pmp->pfs_names[i]) {
647 					kfree(pmp->pfs_names[i], M_HAMMER2);
648 					pmp->pfs_names[i] = NULL;
649 				}
650 				if (rchain) {
651 					hammer2_chain_drop(rchain);
652 					/* focus hint */
653 					if (iroot->cluster.focus == rchain)
654 						iroot->cluster.focus = NULL;
655 				}
656 				pmp->pfs_hmps[i] = NULL;
657 			}
658 			hammer2_mtx_unlock(&iroot->lock);
659 			didfreeze = 1;	/* remaster, unfreeze down below */
660 		} else {
661 			didfreeze = 0;
662 		}
663 
664 		/*
665 		 * Cleanup trailing chains.  Gaps may remain.
666 		 */
667 		for (i = HAMMER2_MAXCLUSTER - 1; i >= 0; --i) {
668 			if (pmp->pfs_hmps[i])
669 				break;
670 		}
671 		iroot->cluster.nchains = i + 1;
672 
673 		/*
674 		 * If the PMP has no elements remaining we can destroy it.
675 		 * (this will transition management threads from frozen->exit).
676 		 */
677 		if (iroot->cluster.nchains == 0) {
678 			kprintf("unmount hmp %p last ref to PMP=%p\n",
679 				hmp, pmp);
680 			hammer2_pfsfree(pmp);
681 			goto again;
682 		}
683 
684 		/*
685 		 * If elements still remain we need to set the REMASTER
686 		 * flag and unfreeze it.
687 		 */
688 		if (didfreeze) {
689 			for (i = 0; i < HAMMER2_MAXCLUSTER; ++i) {
690 				if (pmp->pfs_hmps[i] == NULL)
691 					continue;
692 				hammer2_thr_remaster(&pmp->sync_thrs[i]);
693 				hammer2_thr_unfreeze(&pmp->sync_thrs[i]);
694 				for (j = 0; j < HAMMER2_XOPGROUPS; ++j) {
695 					hammer2_thr_remaster(
696 						&pmp->xop_groups[j].thrs[i]);
697 					hammer2_thr_unfreeze(
698 						&pmp->xop_groups[j].thrs[i]);
699 				}
700 			}
701 		}
702 	}
703 }
704 
705 /*
706  * Mount or remount HAMMER2 fileystem from physical media
707  *
708  *	mountroot
709  *		mp		mount point structure
710  *		path		NULL
711  *		data		<unused>
712  *		cred		<unused>
713  *
714  *	mount
715  *		mp		mount point structure
716  *		path		path to mount point
717  *		data		pointer to argument structure in user space
718  *			volume	volume path (device@LABEL form)
719  *			hflags	user mount flags
720  *		cred		user credentials
721  *
722  * RETURNS:	0	Success
723  *		!0	error number
724  */
725 static
726 int
727 hammer2_vfs_mount(struct mount *mp, char *path, caddr_t data,
728 		  struct ucred *cred)
729 {
730 	struct hammer2_mount_info info;
731 	hammer2_pfs_t *pmp;
732 	hammer2_pfs_t *spmp;
733 	hammer2_dev_t *hmp;
734 	hammer2_key_t key_next;
735 	hammer2_key_t key_dummy;
736 	hammer2_key_t lhc;
737 	struct vnode *devvp;
738 	struct nlookupdata nd;
739 	hammer2_chain_t *parent;
740 	hammer2_chain_t *chain;
741 	hammer2_cluster_t *cluster;
742 	const hammer2_inode_data_t *ripdata;
743 	hammer2_blockref_t bref;
744 	struct file *fp;
745 	char devstr[MNAMELEN];
746 	size_t size;
747 	size_t done;
748 	char *dev;
749 	char *label;
750 	int ronly = 1;
751 	int error;
752 	int cache_index;
753 	int i;
754 
755 	hmp = NULL;
756 	pmp = NULL;
757 	dev = NULL;
758 	label = NULL;
759 	devvp = NULL;
760 	cache_index = -1;
761 
762 	kprintf("hammer2_mount\n");
763 
764 	if (path == NULL) {
765 		/*
766 		 * Root mount
767 		 */
768 		bzero(&info, sizeof(info));
769 		info.cluster_fd = -1;
770 		ksnprintf(devstr, sizeof(devstr), "%s",
771 			  mp->mnt_stat.f_mntfromname);
772 		kprintf("hammer2_mount: root '%s'\n", devstr);
773 	} else {
774 		/*
775 		 * Non-root mount or updating a mount
776 		 */
777 		error = copyin(data, &info, sizeof(info));
778 		if (error)
779 			return (error);
780 
781 		error = copyinstr(info.volume, devstr, MNAMELEN - 1, &done);
782 		if (error)
783 			return (error);
784 	}
785 
786 	/* Extract device and label */
787 	dev = devstr;
788 	label = strchr(devstr, '@');
789 	if (label == NULL ||
790 	    ((label + 1) - dev) > done) {
791 		return (EINVAL);
792 	}
793 	*label = '\0';
794 	label++;
795 	if (*label == '\0')
796 		return (EINVAL);
797 
798 	if (mp->mnt_flag & MNT_UPDATE) {
799 		/*
800 		 * Update mount.  Note that pmp->iroot->cluster is
801 		 * an inode-embedded cluster and thus cannot be
802 		 * directly locked.
803 		 *
804 		 * XXX HAMMER2 needs to implement NFS export via
805 		 *     mountctl.
806 		 */
807 		pmp = MPTOPMP(mp);
808 		cluster = &pmp->iroot->cluster;
809 		for (i = 0; i < cluster->nchains; ++i) {
810 			if (cluster->array[i].chain == NULL)
811 				continue;
812 			hmp = cluster->array[i].chain->hmp;
813 			devvp = hmp->devvp;
814 			error = hammer2_remount(hmp, mp, path,
815 						devvp, cred);
816 			if (error)
817 				break;
818 		}
819 
820 		return error;
821 	}
822 
823 	/*
824 	 * HMP device mount
825 	 *
826 	 * Lookup name and verify it refers to a block device.
827 	 */
828 	if (path) {
829 		error = nlookup_init(&nd, dev, UIO_SYSSPACE, NLC_FOLLOW);
830 		if (error == 0)
831 			error = nlookup(&nd);
832 		if (error == 0)
833 			error = cache_vref(&nd.nl_nch, nd.nl_cred, &devvp);
834 		nlookup_done(&nd);
835 	} else {
836 		/* root mount */
837 		cdev_t cdev = kgetdiskbyname(dev);
838 		error = bdevvp(cdev, &devvp);
839 		if (error)
840 			kprintf("hammer2: cannot find '%s'\n", dev);
841 	}
842 
843 	if (error == 0) {
844 		if (vn_isdisk(devvp, &error))
845 			error = vfs_mountedon(devvp);
846 	}
847 
848 	/*
849 	 * Determine if the device has already been mounted.  After this
850 	 * check hmp will be non-NULL if we are doing the second or more
851 	 * hammer2 mounts from the same device.
852 	 */
853 	lockmgr(&hammer2_mntlk, LK_EXCLUSIVE);
854 	TAILQ_FOREACH(hmp, &hammer2_mntlist, mntentry) {
855 		if (hmp->devvp == devvp)
856 			break;
857 	}
858 
859 	/*
860 	 * Open the device if this isn't a secondary mount and construct
861 	 * the H2 device mount (hmp).
862 	 */
863 	if (hmp == NULL) {
864 		hammer2_chain_t *schain;
865 		hammer2_xid_t xid;
866 
867 		if (error == 0 && vcount(devvp) > 0)
868 			error = EBUSY;
869 
870 		/*
871 		 * Now open the device
872 		 */
873 		if (error == 0) {
874 			ronly = ((mp->mnt_flag & MNT_RDONLY) != 0);
875 			vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
876 			error = vinvalbuf(devvp, V_SAVE, 0, 0);
877 			if (error == 0) {
878 				error = VOP_OPEN(devvp,
879 						 ronly ? FREAD : FREAD | FWRITE,
880 						 FSCRED, NULL);
881 			}
882 			vn_unlock(devvp);
883 		}
884 		if (error && devvp) {
885 			vrele(devvp);
886 			devvp = NULL;
887 		}
888 		if (error) {
889 			lockmgr(&hammer2_mntlk, LK_RELEASE);
890 			return error;
891 		}
892 		hmp = kmalloc(sizeof(*hmp), M_HAMMER2, M_WAITOK | M_ZERO);
893 		ksnprintf(hmp->devrepname, sizeof(hmp->devrepname), "%s", dev);
894 		hmp->ronly = ronly;
895 		hmp->devvp = devvp;
896 		kmalloc_create(&hmp->mchain, "HAMMER2-chains");
897 		TAILQ_INSERT_TAIL(&hammer2_mntlist, hmp, mntentry);
898 		RB_INIT(&hmp->iotree);
899 		spin_init(&hmp->io_spin, "hm2mount_io");
900 		spin_init(&hmp->list_spin, "hm2mount_list");
901 		TAILQ_INIT(&hmp->flushq);
902 
903 		lockinit(&hmp->vollk, "h2vol", 0, 0);
904 		lockinit(&hmp->bulklk, "h2bulk", 0, 0);
905 
906 		/*
907 		 * vchain setup. vchain.data is embedded.
908 		 * vchain.refs is initialized and will never drop to 0.
909 		 *
910 		 * NOTE! voldata is not yet loaded.
911 		 */
912 		hmp->vchain.hmp = hmp;
913 		hmp->vchain.refs = 1;
914 		hmp->vchain.data = (void *)&hmp->voldata;
915 		hmp->vchain.bref.type = HAMMER2_BREF_TYPE_VOLUME;
916 		hmp->vchain.bref.data_off = 0 | HAMMER2_PBUFRADIX;
917 		hmp->vchain.bref.mirror_tid = hmp->voldata.mirror_tid;
918 
919 		hammer2_chain_core_init(&hmp->vchain);
920 		/* hmp->vchain.u.xxx is left NULL */
921 
922 		/*
923 		 * fchain setup.  fchain.data is embedded.
924 		 * fchain.refs is initialized and will never drop to 0.
925 		 *
926 		 * The data is not used but needs to be initialized to
927 		 * pass assertion muster.  We use this chain primarily
928 		 * as a placeholder for the freemap's top-level RBTREE
929 		 * so it does not interfere with the volume's topology
930 		 * RBTREE.
931 		 */
932 		hmp->fchain.hmp = hmp;
933 		hmp->fchain.refs = 1;
934 		hmp->fchain.data = (void *)&hmp->voldata.freemap_blockset;
935 		hmp->fchain.bref.type = HAMMER2_BREF_TYPE_FREEMAP;
936 		hmp->fchain.bref.data_off = 0 | HAMMER2_PBUFRADIX;
937 		hmp->fchain.bref.mirror_tid = hmp->voldata.freemap_tid;
938 		hmp->fchain.bref.methods =
939 			HAMMER2_ENC_CHECK(HAMMER2_CHECK_FREEMAP) |
940 			HAMMER2_ENC_COMP(HAMMER2_COMP_NONE);
941 
942 		hammer2_chain_core_init(&hmp->fchain);
943 		/* hmp->fchain.u.xxx is left NULL */
944 
945 		/*
946 		 * Install the volume header and initialize fields from
947 		 * voldata.
948 		 */
949 		error = hammer2_install_volume_header(hmp);
950 		if (error) {
951 			hammer2_unmount_helper(mp, NULL, hmp);
952 			lockmgr(&hammer2_mntlk, LK_RELEASE);
953 			hammer2_vfs_unmount(mp, MNT_FORCE);
954 			return error;
955 		}
956 
957 		/*
958 		 * Really important to get these right or flush will get
959 		 * confused.
960 		 */
961 		hmp->spmp = hammer2_pfsalloc(NULL, NULL, 0);
962 		kprintf("alloc spmp %p tid %016jx\n",
963 			hmp->spmp, hmp->voldata.mirror_tid);
964 		spmp = hmp->spmp;
965 
966 		/*
967 		 * Dummy-up vchain and fchain's modify_tid.  mirror_tid
968 		 * is inherited from the volume header.
969 		 */
970 		xid = 0;
971 		hmp->vchain.bref.mirror_tid = hmp->voldata.mirror_tid;
972 		hmp->vchain.bref.modify_tid = hmp->vchain.bref.mirror_tid;
973 		hmp->vchain.pmp = spmp;
974 		hmp->fchain.bref.mirror_tid = hmp->voldata.freemap_tid;
975 		hmp->fchain.bref.modify_tid = hmp->fchain.bref.mirror_tid;
976 		hmp->fchain.pmp = spmp;
977 
978 		/*
979 		 * First locate the super-root inode, which is key 0
980 		 * relative to the volume header's blockset.
981 		 *
982 		 * Then locate the root inode by scanning the directory keyspace
983 		 * represented by the label.
984 		 */
985 		parent = hammer2_chain_lookup_init(&hmp->vchain, 0);
986 		schain = hammer2_chain_lookup(&parent, &key_dummy,
987 				      HAMMER2_SROOT_KEY, HAMMER2_SROOT_KEY,
988 				      &cache_index, 0);
989 		hammer2_chain_lookup_done(parent);
990 		if (schain == NULL) {
991 			kprintf("hammer2_mount: invalid super-root\n");
992 			hammer2_unmount_helper(mp, NULL, hmp);
993 			lockmgr(&hammer2_mntlk, LK_RELEASE);
994 			hammer2_vfs_unmount(mp, MNT_FORCE);
995 			return EINVAL;
996 		}
997 		if (schain->error) {
998 			kprintf("hammer2_mount: error %s reading super-root\n",
999 				hammer2_error_str(schain->error));
1000 			hammer2_chain_unlock(schain);
1001 			hammer2_chain_drop(schain);
1002 			schain = NULL;
1003 			hammer2_unmount_helper(mp, NULL, hmp);
1004 			lockmgr(&hammer2_mntlk, LK_RELEASE);
1005 			hammer2_vfs_unmount(mp, MNT_FORCE);
1006 			return EINVAL;
1007 		}
1008 
1009 		/*
1010 		 * The super-root always uses an inode_tid of 1 when
1011 		 * creating PFSs.
1012 		 */
1013 		spmp->inode_tid = 1;
1014 		spmp->modify_tid = schain->bref.modify_tid + 1;
1015 
1016 		/*
1017 		 * Sanity-check schain's pmp and finish initialization.
1018 		 * Any chain belonging to the super-root topology should
1019 		 * have a NULL pmp (not even set to spmp).
1020 		 */
1021 		ripdata = &hammer2_chain_rdata(schain)->ipdata;
1022 		KKASSERT(schain->pmp == NULL);
1023 		spmp->pfs_clid = ripdata->meta.pfs_clid;
1024 
1025 		/*
1026 		 * Replace the dummy spmp->iroot with a real one.  It's
1027 		 * easier to just do a wholesale replacement than to try
1028 		 * to update the chain and fixup the iroot fields.
1029 		 *
1030 		 * The returned inode is locked with the supplied cluster.
1031 		 */
1032 		cluster = hammer2_cluster_from_chain(schain);
1033 		hammer2_inode_drop(spmp->iroot);
1034 		spmp->iroot = NULL;
1035 		spmp->iroot = hammer2_inode_get(spmp, NULL, cluster, -1);
1036 		spmp->spmp_hmp = hmp;
1037 		spmp->pfs_types[0] = ripdata->meta.pfs_type;
1038 		spmp->pfs_hmps[0] = hmp;
1039 		hammer2_inode_ref(spmp->iroot);
1040 		hammer2_inode_unlock(spmp->iroot);
1041 		hammer2_cluster_unlock(cluster);
1042 		hammer2_cluster_drop(cluster);
1043 		schain = NULL;
1044 		/* leave spmp->iroot with one ref */
1045 
1046 		if ((mp->mnt_flag & MNT_RDONLY) == 0) {
1047 			error = hammer2_recovery(hmp);
1048 			/* XXX do something with error */
1049 		}
1050 		hammer2_update_pmps(hmp);
1051 		hammer2_iocom_init(hmp);
1052 
1053 		/*
1054 		 * Ref the cluster management messaging descriptor.  The mount
1055 		 * program deals with the other end of the communications pipe.
1056 		 *
1057 		 * Root mounts typically do not supply one.
1058 		 */
1059 		if (info.cluster_fd >= 0) {
1060 			fp = holdfp(curproc->p_fd, info.cluster_fd, -1);
1061 			if (fp) {
1062 				hammer2_cluster_reconnect(hmp, fp);
1063 			} else {
1064 				kprintf("hammer2_mount: bad cluster_fd!\n");
1065 			}
1066 		}
1067 	} else {
1068 		spmp = hmp->spmp;
1069 	}
1070 
1071 	/*
1072 	 * Lookup the mount point under the media-localized super-root.
1073 	 * Scanning hammer2_pfslist doesn't help us because it represents
1074 	 * PFS cluster ids which can aggregate several named PFSs together.
1075 	 *
1076 	 * cluster->pmp will incorrectly point to spmp and must be fixed
1077 	 * up later on.
1078 	 */
1079 	hammer2_inode_lock(spmp->iroot, 0);
1080 	parent = hammer2_inode_chain(spmp->iroot, 0, HAMMER2_RESOLVE_ALWAYS);
1081 	lhc = hammer2_dirhash(label, strlen(label));
1082 	chain = hammer2_chain_lookup(&parent, &key_next,
1083 				     lhc, lhc + HAMMER2_DIRHASH_LOMASK,
1084 				     &cache_index, 0);
1085 	while (chain) {
1086 		if (chain->bref.type == HAMMER2_BREF_TYPE_INODE &&
1087 		    strcmp(label, chain->data->ipdata.filename) == 0) {
1088 			break;
1089 		}
1090 		chain = hammer2_chain_next(&parent, chain, &key_next,
1091 					    key_next,
1092 					    lhc + HAMMER2_DIRHASH_LOMASK,
1093 					    &cache_index, 0);
1094 	}
1095 	if (parent) {
1096 		hammer2_chain_unlock(parent);
1097 		hammer2_chain_drop(parent);
1098 	}
1099 	hammer2_inode_unlock(spmp->iroot);
1100 
1101 	/*
1102 	 * PFS could not be found?
1103 	 */
1104 	if (chain == NULL) {
1105 		kprintf("hammer2_mount: PFS label not found\n");
1106 		hammer2_unmount_helper(mp, NULL, hmp);
1107 		lockmgr(&hammer2_mntlk, LK_RELEASE);
1108 		hammer2_vfs_unmount(mp, MNT_FORCE);
1109 
1110 		return EINVAL;
1111 	}
1112 
1113 	/*
1114 	 * Acquire the pmp structure (it should have already been allocated
1115 	 * via hammer2_update_pmps() so do not pass cluster in to add to
1116 	 * available chains).
1117 	 *
1118 	 * Check if the cluster has already been mounted.  A cluster can
1119 	 * only be mounted once, use null mounts to mount additional copies.
1120 	 */
1121 	ripdata = &chain->data->ipdata;
1122 	bref = chain->bref;
1123 	pmp = hammer2_pfsalloc(NULL, ripdata, bref.modify_tid);
1124 	hammer2_chain_unlock(chain);
1125 	hammer2_chain_drop(chain);
1126 
1127 	if (pmp->mp) {
1128 		kprintf("hammer2_mount: PFS already mounted!\n");
1129 		hammer2_unmount_helper(mp, NULL, hmp);
1130 		lockmgr(&hammer2_mntlk, LK_RELEASE);
1131 		hammer2_vfs_unmount(mp, MNT_FORCE);
1132 
1133 		return EBUSY;
1134 	}
1135 
1136 	/*
1137 	 * Finish the mount
1138 	 */
1139         kprintf("hammer2_mount hmp=%p pmp=%p\n", hmp, pmp);
1140 
1141         mp->mnt_flag = MNT_LOCAL;
1142         mp->mnt_kern_flag |= MNTK_ALL_MPSAFE;   /* all entry pts are SMP */
1143         mp->mnt_kern_flag |= MNTK_THR_SYNC;     /* new vsyncscan semantics */
1144 
1145         /*
1146          * required mount structure initializations
1147          */
1148         mp->mnt_stat.f_iosize = HAMMER2_PBUFSIZE;
1149         mp->mnt_stat.f_bsize = HAMMER2_PBUFSIZE;
1150 
1151         mp->mnt_vstat.f_frsize = HAMMER2_PBUFSIZE;
1152         mp->mnt_vstat.f_bsize = HAMMER2_PBUFSIZE;
1153 
1154         /*
1155          * Optional fields
1156          */
1157         mp->mnt_iosize_max = MAXPHYS;
1158 
1159 	/*
1160 	 * Connect up mount pointers.
1161 	 */
1162 	hammer2_mount_helper(mp, pmp);
1163 
1164         lockmgr(&hammer2_mntlk, LK_RELEASE);
1165 
1166 	/*
1167 	 * Finish setup
1168 	 */
1169 	vfs_getnewfsid(mp);
1170 	vfs_add_vnodeops(mp, &hammer2_vnode_vops, &mp->mnt_vn_norm_ops);
1171 	vfs_add_vnodeops(mp, &hammer2_spec_vops, &mp->mnt_vn_spec_ops);
1172 	vfs_add_vnodeops(mp, &hammer2_fifo_vops, &mp->mnt_vn_fifo_ops);
1173 
1174 	if (path) {
1175 		copyinstr(info.volume, mp->mnt_stat.f_mntfromname,
1176 			  MNAMELEN - 1, &size);
1177 		bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
1178 	} /* else root mount, already in there */
1179 
1180 	bzero(mp->mnt_stat.f_mntonname, sizeof(mp->mnt_stat.f_mntonname));
1181 	if (path) {
1182 		copyinstr(path, mp->mnt_stat.f_mntonname,
1183 			  sizeof(mp->mnt_stat.f_mntonname) - 1,
1184 			  &size);
1185 	} else {
1186 		/* root mount */
1187 		mp->mnt_stat.f_mntonname[0] = '/';
1188 	}
1189 
1190 	/*
1191 	 * Initial statfs to prime mnt_stat.
1192 	 */
1193 	hammer2_vfs_statfs(mp, &mp->mnt_stat, cred);
1194 
1195 	return 0;
1196 }
1197 
1198 /*
1199  * Scan PFSs under the super-root and create hammer2_pfs structures.
1200  */
1201 static
1202 void
1203 hammer2_update_pmps(hammer2_dev_t *hmp)
1204 {
1205 	const hammer2_inode_data_t *ripdata;
1206 	hammer2_chain_t *parent;
1207 	hammer2_chain_t *chain;
1208 	hammer2_blockref_t bref;
1209 	hammer2_pfs_t *spmp;
1210 	hammer2_pfs_t *pmp;
1211 	hammer2_key_t key_next;
1212 	int cache_index = -1;
1213 
1214 	/*
1215 	 * Lookup mount point under the media-localized super-root.
1216 	 *
1217 	 * cluster->pmp will incorrectly point to spmp and must be fixed
1218 	 * up later on.
1219 	 */
1220 	spmp = hmp->spmp;
1221 	hammer2_inode_lock(spmp->iroot, 0);
1222 	parent = hammer2_inode_chain(spmp->iroot, 0, HAMMER2_RESOLVE_ALWAYS);
1223 	chain = hammer2_chain_lookup(&parent, &key_next,
1224 					 HAMMER2_KEY_MIN, HAMMER2_KEY_MAX,
1225 					 &cache_index, 0);
1226 	while (chain) {
1227 		if (chain->bref.type != HAMMER2_BREF_TYPE_INODE)
1228 			continue;
1229 		ripdata = &chain->data->ipdata;
1230 		bref = chain->bref;
1231 		kprintf("ADD LOCAL PFS: %s\n", ripdata->filename);
1232 
1233 		pmp = hammer2_pfsalloc(chain, ripdata, bref.modify_tid);
1234 		chain = hammer2_chain_next(&parent, chain, &key_next,
1235 					   key_next, HAMMER2_KEY_MAX,
1236 					   &cache_index, 0);
1237 	}
1238 	if (parent) {
1239 		hammer2_chain_unlock(parent);
1240 		hammer2_chain_drop(parent);
1241 	}
1242 	hammer2_inode_unlock(spmp->iroot);
1243 }
1244 
1245 static
1246 int
1247 hammer2_remount(hammer2_dev_t *hmp, struct mount *mp, char *path __unused,
1248 		struct vnode *devvp, struct ucred *cred)
1249 {
1250 	int error;
1251 
1252 	if (hmp->ronly && (mp->mnt_kern_flag & MNTK_WANTRDWR)) {
1253 		error = hammer2_recovery(hmp);
1254 	} else {
1255 		error = 0;
1256 	}
1257 	return error;
1258 }
1259 
1260 static
1261 int
1262 hammer2_vfs_unmount(struct mount *mp, int mntflags)
1263 {
1264 	hammer2_pfs_t *pmp;
1265 	int flags;
1266 	int error = 0;
1267 
1268 	pmp = MPTOPMP(mp);
1269 
1270 	if (pmp == NULL)
1271 		return(0);
1272 
1273 	lockmgr(&hammer2_mntlk, LK_EXCLUSIVE);
1274 
1275 	/*
1276 	 * If mount initialization proceeded far enough we must flush
1277 	 * its vnodes and sync the underlying mount points.  Three syncs
1278 	 * are required to fully flush the filesystem (freemap updates lag
1279 	 * by one flush, and one extra for safety).
1280 	 */
1281 	if (mntflags & MNT_FORCE)
1282 		flags = FORCECLOSE;
1283 	else
1284 		flags = 0;
1285 	if (pmp->iroot) {
1286 		error = vflush(mp, 0, flags);
1287 		if (error)
1288 			goto failed;
1289 		hammer2_vfs_sync(mp, MNT_WAIT);
1290 		hammer2_vfs_sync(mp, MNT_WAIT);
1291 		hammer2_vfs_sync(mp, MNT_WAIT);
1292 	}
1293 
1294 	/*
1295 	 * Cleanup the frontend support XOPS threads
1296 	 */
1297 	hammer2_xop_helper_cleanup(pmp);
1298 
1299 	/*
1300 	 * Cleanup our reference on ihidden.
1301 	 */
1302 	if (pmp->ihidden) {
1303 		hammer2_inode_drop(pmp->ihidden);
1304 		pmp->ihidden = NULL;
1305 	}
1306 	if (pmp->mp)
1307 		hammer2_unmount_helper(mp, pmp, NULL);
1308 
1309 	error = 0;
1310 failed:
1311 	lockmgr(&hammer2_mntlk, LK_RELEASE);
1312 
1313 	return (error);
1314 }
1315 
1316 /*
1317  * Mount helper, hook the system mount into our PFS.
1318  * The mount lock is held.
1319  *
1320  * We must bump the mount_count on related devices for any
1321  * mounted PFSs.
1322  */
1323 static
1324 void
1325 hammer2_mount_helper(struct mount *mp, hammer2_pfs_t *pmp)
1326 {
1327 	hammer2_cluster_t *cluster;
1328 	hammer2_chain_t *rchain;
1329 	int i;
1330 
1331         mp->mnt_data = (qaddr_t)pmp;
1332 	pmp->mp = mp;
1333 
1334 	/*
1335 	 * After pmp->mp is set we have to adjust hmp->mount_count.
1336 	 */
1337 	cluster = &pmp->iroot->cluster;
1338 	for (i = 0; i < cluster->nchains; ++i) {
1339 		rchain = cluster->array[i].chain;
1340 		if (rchain == NULL)
1341 			continue;
1342 		++rchain->hmp->mount_count;
1343 		kprintf("hammer2_mount hmp=%p ++mount_count=%d\n",
1344 			rchain->hmp, rchain->hmp->mount_count);
1345 	}
1346 
1347 	/*
1348 	 * Create missing Xop threads
1349 	 */
1350 	hammer2_xop_helper_create(pmp);
1351 }
1352 
1353 /*
1354  * Mount helper, unhook the system mount from our PFS.
1355  * The mount lock is held.
1356  *
1357  * If hmp is supplied a mount responsible for being the first to open
1358  * the block device failed and the block device and all PFSs using the
1359  * block device must be cleaned up.
1360  *
1361  * If pmp is supplied multiple devices might be backing the PFS and each
1362  * must be disconnect.  This might not be the last PFS using some of the
1363  * underlying devices.  Also, we have to adjust our hmp->mount_count
1364  * accounting for the devices backing the pmp which is now undergoing an
1365  * unmount.
1366  */
1367 static
1368 void
1369 hammer2_unmount_helper(struct mount *mp, hammer2_pfs_t *pmp, hammer2_dev_t *hmp)
1370 {
1371 	hammer2_cluster_t *cluster;
1372 	hammer2_chain_t *rchain;
1373 	struct vnode *devvp;
1374 	int dumpcnt;
1375 	int ronly = 0;
1376 	int i;
1377 
1378 	/*
1379 	 * If no device supplied this is a high-level unmount and we have to
1380 	 * to disconnect the mount, adjust mount_count, and locate devices
1381 	 * that might now have no mounts.
1382 	 */
1383 	if (pmp) {
1384 		KKASSERT(hmp == NULL);
1385 		KKASSERT((void *)(intptr_t)mp->mnt_data == pmp);
1386 		pmp->mp = NULL;
1387 		mp->mnt_data = NULL;
1388 
1389 		/*
1390 		 * After pmp->mp is cleared we have to account for
1391 		 * mount_count.
1392 		 */
1393 		cluster = &pmp->iroot->cluster;
1394 		for (i = 0; i < cluster->nchains; ++i) {
1395 			rchain = cluster->array[i].chain;
1396 			if (rchain == NULL)
1397 				continue;
1398 			--rchain->hmp->mount_count;
1399 			kprintf("hammer2_unmount hmp=%p --mount_count=%d\n",
1400 				rchain->hmp, rchain->hmp->mount_count);
1401 			/* scrapping hmp now may invalidate the pmp */
1402 		}
1403 again:
1404 		TAILQ_FOREACH(hmp, &hammer2_mntlist, mntentry) {
1405 			if (hmp->mount_count == 0) {
1406 				hammer2_unmount_helper(NULL, NULL, hmp);
1407 				goto again;
1408 			}
1409 		}
1410 		return;
1411 	}
1412 
1413 	/*
1414 	 * Try to terminate the block device.  We can't terminate it if
1415 	 * there are still PFSs referencing it.
1416 	 */
1417 	kprintf("hammer2_unmount hmp=%p mount_count=%d\n",
1418 		hmp, hmp->mount_count);
1419 	if (hmp->mount_count)
1420 		return;
1421 
1422 	hammer2_pfsfree_scan(hmp);
1423 	hammer2_dev_exlock(hmp);	/* XXX order */
1424 
1425 	/*
1426 	 * Cycle the volume data lock as a safety (probably not needed any
1427 	 * more).  To ensure everything is out we need to flush at least
1428 	 * three times.  (1) The running of the unlinkq can dirty the
1429 	 * filesystem, (2) A normal flush can dirty the freemap, and
1430 	 * (3) ensure that the freemap is fully synchronized.
1431 	 *
1432 	 * The next mount's recovery scan can clean everything up but we want
1433 	 * to leave the filesystem in a 100% clean state on a normal unmount.
1434 	 */
1435 #if 0
1436 	hammer2_voldata_lock(hmp);
1437 	hammer2_voldata_unlock(hmp);
1438 #endif
1439 	hammer2_iocom_uninit(hmp);
1440 
1441 	if ((hmp->vchain.flags | hmp->fchain.flags) &
1442 	    HAMMER2_CHAIN_FLUSH_MASK) {
1443 		kprintf("hammer2_unmount: chains left over "
1444 			"after final sync\n");
1445 		kprintf("    vchain %08x\n", hmp->vchain.flags);
1446 		kprintf("    fchain %08x\n", hmp->fchain.flags);
1447 
1448 		if (hammer2_debug & 0x0010)
1449 			Debugger("entered debugger");
1450 	}
1451 
1452 	KKASSERT(hmp->spmp == NULL);
1453 
1454 	/*
1455 	 * Finish up with the device vnode
1456 	 */
1457 	if ((devvp = hmp->devvp) != NULL) {
1458 		vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
1459 		vinvalbuf(devvp, (ronly ? 0 : V_SAVE), 0, 0);
1460 		hmp->devvp = NULL;
1461 		VOP_CLOSE(devvp, (ronly ? FREAD : FREAD|FWRITE), NULL);
1462 		vn_unlock(devvp);
1463 		vrele(devvp);
1464 		devvp = NULL;
1465 	}
1466 
1467 	/*
1468 	 * Clear vchain/fchain flags that might prevent final cleanup
1469 	 * of these chains.
1470 	 */
1471 	if (hmp->vchain.flags & HAMMER2_CHAIN_MODIFIED) {
1472 		atomic_clear_int(&hmp->vchain.flags,
1473 				 HAMMER2_CHAIN_MODIFIED);
1474 		hammer2_pfs_memory_wakeup(hmp->vchain.pmp);
1475 		hammer2_chain_drop(&hmp->vchain);
1476 	}
1477 	if (hmp->vchain.flags & HAMMER2_CHAIN_UPDATE) {
1478 		atomic_clear_int(&hmp->vchain.flags,
1479 				 HAMMER2_CHAIN_UPDATE);
1480 		hammer2_chain_drop(&hmp->vchain);
1481 	}
1482 
1483 	if (hmp->fchain.flags & HAMMER2_CHAIN_MODIFIED) {
1484 		atomic_clear_int(&hmp->fchain.flags,
1485 				 HAMMER2_CHAIN_MODIFIED);
1486 		hammer2_pfs_memory_wakeup(hmp->fchain.pmp);
1487 		hammer2_chain_drop(&hmp->fchain);
1488 	}
1489 	if (hmp->fchain.flags & HAMMER2_CHAIN_UPDATE) {
1490 		atomic_clear_int(&hmp->fchain.flags,
1491 				 HAMMER2_CHAIN_UPDATE);
1492 		hammer2_chain_drop(&hmp->fchain);
1493 	}
1494 
1495 	/*
1496 	 * Final drop of embedded freemap root chain to
1497 	 * clean up fchain.core (fchain structure is not
1498 	 * flagged ALLOCATED so it is cleaned out and then
1499 	 * left to rot).
1500 	 */
1501 	hammer2_chain_drop(&hmp->fchain);
1502 
1503 	/*
1504 	 * Final drop of embedded volume root chain to clean
1505 	 * up vchain.core (vchain structure is not flagged
1506 	 * ALLOCATED so it is cleaned out and then left to
1507 	 * rot).
1508 	 */
1509 	dumpcnt = 50;
1510 	hammer2_dump_chain(&hmp->vchain, 0, &dumpcnt, 'v');
1511 	dumpcnt = 50;
1512 	hammer2_dump_chain(&hmp->fchain, 0, &dumpcnt, 'f');
1513 	hammer2_dev_unlock(hmp);
1514 	hammer2_chain_drop(&hmp->vchain);
1515 
1516 	hammer2_io_cleanup(hmp, &hmp->iotree);
1517 	if (hmp->iofree_count) {
1518 		kprintf("io_cleanup: %d I/O's left hanging\n",
1519 			hmp->iofree_count);
1520 	}
1521 
1522 	TAILQ_REMOVE(&hammer2_mntlist, hmp, mntentry);
1523 	kmalloc_destroy(&hmp->mchain);
1524 	kfree(hmp, M_HAMMER2);
1525 }
1526 
1527 static
1528 int
1529 hammer2_vfs_vget(struct mount *mp, struct vnode *dvp,
1530 	     ino_t ino, struct vnode **vpp)
1531 {
1532 	kprintf("hammer2_vget\n");
1533 	return (EOPNOTSUPP);
1534 }
1535 
1536 static
1537 int
1538 hammer2_vfs_root(struct mount *mp, struct vnode **vpp)
1539 {
1540 	hammer2_pfs_t *pmp;
1541 	int error;
1542 	struct vnode *vp;
1543 
1544 	pmp = MPTOPMP(mp);
1545 	if (pmp->iroot == NULL) {
1546 		*vpp = NULL;
1547 		return EINVAL;
1548 	}
1549 
1550 	error = 0;
1551 	hammer2_inode_lock(pmp->iroot, HAMMER2_RESOLVE_SHARED);
1552 
1553 	while (pmp->inode_tid == 0) {
1554 		hammer2_xop_ipcluster_t *xop;
1555 		hammer2_inode_meta_t *meta;
1556 
1557 		xop = hammer2_xop_alloc(pmp->iroot, HAMMER2_XOP_MODIFYING);
1558 		hammer2_xop_start(&xop->head, hammer2_xop_ipcluster);
1559 		error = hammer2_xop_collect(&xop->head, 0);
1560 
1561 		if (error == 0) {
1562 			meta = &xop->head.cluster.focus->data->ipdata.meta;
1563 			pmp->iroot->meta = *meta;
1564 			pmp->inode_tid = meta->pfs_inum + 1;
1565 			if (pmp->inode_tid < HAMMER2_INODE_START)
1566 				pmp->inode_tid = HAMMER2_INODE_START;
1567 			pmp->modify_tid =
1568 				xop->head.cluster.focus->bref.modify_tid + 1;
1569 			kprintf("PFS: Starting inode %jd\n",
1570 				(intmax_t)pmp->inode_tid);
1571 			kprintf("PMP focus good set nextino=%ld mod=%016jx\n",
1572 				pmp->inode_tid, pmp->modify_tid);
1573 			wakeup(&pmp->iroot);
1574 
1575 			hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
1576 
1577 			/*
1578 			 * Prime the mount info.
1579 			 */
1580 			hammer2_vfs_statfs(mp, &mp->mnt_stat, NULL);
1581 
1582 			/*
1583 			 * With the cluster operational, check for and
1584 			 * install ihidden if needed.  The install_hidden
1585 			 * code needs to get a transaction so we must unlock
1586 			 * iroot around it.
1587 			 *
1588 			 * This is only applicable PFS mounts, there is no
1589 			 * hidden directory in the spmp.
1590 			 */
1591 			hammer2_inode_unlock(pmp->iroot);
1592 			hammer2_inode_install_hidden(pmp);
1593 			hammer2_inode_lock(pmp->iroot, HAMMER2_RESOLVE_SHARED);
1594 
1595 			break;
1596 		}
1597 
1598 		/*
1599 		 * Loop, try again
1600 		 */
1601 		hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
1602 		hammer2_inode_unlock(pmp->iroot);
1603 		error = tsleep(&pmp->iroot, PCATCH, "h2root", hz);
1604 		hammer2_inode_lock(pmp->iroot, HAMMER2_RESOLVE_SHARED);
1605 		if (error == EINTR)
1606 			break;
1607 	}
1608 
1609 	if (error) {
1610 		hammer2_inode_unlock(pmp->iroot);
1611 		*vpp = NULL;
1612 	} else {
1613 		vp = hammer2_igetv(pmp->iroot, &error);
1614 		hammer2_inode_unlock(pmp->iroot);
1615 		*vpp = vp;
1616 	}
1617 
1618 	return (error);
1619 }
1620 
1621 /*
1622  * Filesystem status
1623  *
1624  * XXX incorporate ipdata->meta.inode_quota and data_quota
1625  */
1626 static
1627 int
1628 hammer2_vfs_statfs(struct mount *mp, struct statfs *sbp, struct ucred *cred)
1629 {
1630 	hammer2_pfs_t *pmp;
1631 	hammer2_dev_t *hmp;
1632 	hammer2_blockref_t bref;
1633 	int i;
1634 
1635 	/*
1636 	 * NOTE: iroot might not have validated the cluster yet.
1637 	 */
1638 	pmp = MPTOPMP(mp);
1639 
1640 	mp->mnt_stat.f_files = 0;
1641 	mp->mnt_stat.f_ffree = 0;
1642 	mp->mnt_stat.f_blocks = 0;
1643 	mp->mnt_stat.f_bfree = 0;
1644 	mp->mnt_stat.f_bavail = 0;
1645 
1646 	for (i = 0; i < pmp->iroot->cluster.nchains; ++i) {
1647 		hmp = pmp->pfs_hmps[i];
1648 		if (hmp == NULL)
1649 			continue;
1650 		if (pmp->iroot->cluster.array[i].chain)
1651 			bref = pmp->iroot->cluster.array[i].chain->bref;
1652 		else
1653 			bzero(&bref, sizeof(bref));
1654 
1655 		mp->mnt_stat.f_files = bref.inode_count;
1656 		mp->mnt_stat.f_ffree = 0;
1657 		mp->mnt_stat.f_blocks = (bref.data_count +
1658 					 hmp->voldata.allocator_free) /
1659 					mp->mnt_vstat.f_bsize;
1660 		mp->mnt_stat.f_bfree =  hmp->voldata.allocator_free /
1661 					mp->mnt_vstat.f_bsize;
1662 		mp->mnt_stat.f_bavail = mp->mnt_stat.f_bfree;
1663 
1664 		*sbp = mp->mnt_stat;
1665 	}
1666 	return (0);
1667 }
1668 
1669 static
1670 int
1671 hammer2_vfs_statvfs(struct mount *mp, struct statvfs *sbp, struct ucred *cred)
1672 {
1673 	hammer2_pfs_t *pmp;
1674 	hammer2_dev_t *hmp;
1675 	hammer2_blockref_t bref;
1676 	int i;
1677 
1678 	/*
1679 	 * NOTE: iroot might not have validated the cluster yet.
1680 	 */
1681 	pmp = MPTOPMP(mp);
1682 
1683 	mp->mnt_vstat.f_bsize = 0;
1684 	mp->mnt_vstat.f_files = 0;
1685 	mp->mnt_vstat.f_ffree = 0;
1686 	mp->mnt_vstat.f_blocks = 0;
1687 	mp->mnt_vstat.f_bfree = 0;
1688 	mp->mnt_vstat.f_bavail = 0;
1689 
1690 	for (i = 0; i < pmp->iroot->cluster.nchains; ++i) {
1691 		hmp = pmp->pfs_hmps[i];
1692 		if (hmp == NULL)
1693 			continue;
1694 		if (pmp->iroot->cluster.array[i].chain)
1695 			bref = pmp->iroot->cluster.array[i].chain->bref;
1696 		else
1697 			bzero(&bref, sizeof(bref));
1698 
1699 		mp->mnt_vstat.f_bsize = HAMMER2_PBUFSIZE;
1700 		mp->mnt_vstat.f_files = bref.inode_count;
1701 		mp->mnt_vstat.f_ffree = 0;
1702 		mp->mnt_vstat.f_blocks = (bref.data_count +
1703 					 hmp->voldata.allocator_free) /
1704 					mp->mnt_vstat.f_bsize;
1705 		mp->mnt_vstat.f_bfree = hmp->voldata.allocator_free /
1706 					mp->mnt_vstat.f_bsize;
1707 		mp->mnt_vstat.f_bavail = mp->mnt_vstat.f_bfree;
1708 
1709 		*sbp = mp->mnt_vstat;
1710 	}
1711 	return (0);
1712 }
1713 
1714 /*
1715  * Mount-time recovery (RW mounts)
1716  *
1717  * Updates to the free block table are allowed to lag flushes by one
1718  * transaction.  In case of a crash, then on a fresh mount we must do an
1719  * incremental scan of the last committed transaction id and make sure that
1720  * all related blocks have been marked allocated.
1721  *
1722  * The super-root topology and each PFS has its own transaction id domain,
1723  * so we must track PFS boundary transitions.
1724  */
1725 struct hammer2_recovery_elm {
1726 	TAILQ_ENTRY(hammer2_recovery_elm) entry;
1727 	hammer2_chain_t *chain;
1728 	hammer2_tid_t sync_tid;
1729 };
1730 
1731 TAILQ_HEAD(hammer2_recovery_list, hammer2_recovery_elm);
1732 
1733 struct hammer2_recovery_info {
1734 	struct hammer2_recovery_list list;
1735 	hammer2_tid_t	mtid;
1736 	int	depth;
1737 };
1738 
1739 static int hammer2_recovery_scan(hammer2_dev_t *hmp,
1740 			hammer2_chain_t *parent,
1741 			struct hammer2_recovery_info *info,
1742 			hammer2_tid_t sync_tid);
1743 
1744 #define HAMMER2_RECOVERY_MAXDEPTH	10
1745 
1746 static
1747 int
1748 hammer2_recovery(hammer2_dev_t *hmp)
1749 {
1750 	struct hammer2_recovery_info info;
1751 	struct hammer2_recovery_elm *elm;
1752 	hammer2_chain_t *parent;
1753 	hammer2_tid_t sync_tid;
1754 	hammer2_tid_t mirror_tid;
1755 	int error;
1756 	int cumulative_error = 0;
1757 
1758 	hammer2_trans_init(hmp->spmp, 0);
1759 
1760 	sync_tid = hmp->voldata.freemap_tid;
1761 	mirror_tid = hmp->voldata.mirror_tid;
1762 
1763 	kprintf("hammer2 mount \"%s\": ", hmp->devrepname);
1764 	if (sync_tid >= mirror_tid) {
1765 		kprintf(" no recovery needed\n");
1766 	} else {
1767 		kprintf(" freemap recovery %016jx-%016jx\n",
1768 			sync_tid + 1, mirror_tid);
1769 	}
1770 
1771 	TAILQ_INIT(&info.list);
1772 	info.depth = 0;
1773 	parent = hammer2_chain_lookup_init(&hmp->vchain, 0);
1774 	cumulative_error = hammer2_recovery_scan(hmp, parent,
1775 						 &info, sync_tid);
1776 	hammer2_chain_lookup_done(parent);
1777 
1778 	while ((elm = TAILQ_FIRST(&info.list)) != NULL) {
1779 		TAILQ_REMOVE(&info.list, elm, entry);
1780 		parent = elm->chain;
1781 		sync_tid = elm->sync_tid;
1782 		kfree(elm, M_HAMMER2);
1783 
1784 		hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS);
1785 		error = hammer2_recovery_scan(hmp, parent,
1786 					      &info, hmp->voldata.freemap_tid);
1787 		hammer2_chain_unlock(parent);
1788 		hammer2_chain_drop(parent);	/* drop elm->chain ref */
1789 		if (error)
1790 			cumulative_error = error;
1791 	}
1792 	hammer2_trans_done(hmp->spmp);
1793 
1794 	return cumulative_error;
1795 }
1796 
1797 static
1798 int
1799 hammer2_recovery_scan(hammer2_dev_t *hmp, hammer2_chain_t *parent,
1800 		      struct hammer2_recovery_info *info,
1801 		      hammer2_tid_t sync_tid)
1802 {
1803 	const hammer2_inode_data_t *ripdata;
1804 	hammer2_chain_t *chain;
1805 	int cache_index;
1806 	int cumulative_error = 0;
1807 	int error;
1808 
1809 	/*
1810 	 * Adjust freemap to ensure that the block(s) are marked allocated.
1811 	 */
1812 	if (parent->bref.type != HAMMER2_BREF_TYPE_VOLUME) {
1813 		hammer2_freemap_adjust(hmp, &parent->bref,
1814 				       HAMMER2_FREEMAP_DORECOVER);
1815 	}
1816 
1817 	/*
1818 	 * Check type for recursive scan
1819 	 */
1820 	switch(parent->bref.type) {
1821 	case HAMMER2_BREF_TYPE_VOLUME:
1822 		/* data already instantiated */
1823 		break;
1824 	case HAMMER2_BREF_TYPE_INODE:
1825 		/*
1826 		 * Must instantiate data for DIRECTDATA test and also
1827 		 * for recursion.
1828 		 */
1829 		hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS);
1830 		ripdata = &hammer2_chain_rdata(parent)->ipdata;
1831 		if (ripdata->meta.op_flags & HAMMER2_OPFLAG_DIRECTDATA) {
1832 			/* not applicable to recovery scan */
1833 			hammer2_chain_unlock(parent);
1834 			return 0;
1835 		}
1836 		hammer2_chain_unlock(parent);
1837 		break;
1838 	case HAMMER2_BREF_TYPE_INDIRECT:
1839 		/*
1840 		 * Must instantiate data for recursion
1841 		 */
1842 		hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS);
1843 		hammer2_chain_unlock(parent);
1844 		break;
1845 	case HAMMER2_BREF_TYPE_DATA:
1846 	case HAMMER2_BREF_TYPE_FREEMAP:
1847 	case HAMMER2_BREF_TYPE_FREEMAP_NODE:
1848 	case HAMMER2_BREF_TYPE_FREEMAP_LEAF:
1849 		/* not applicable to recovery scan */
1850 		return 0;
1851 		break;
1852 	default:
1853 		return EDOM;
1854 	}
1855 
1856 	/*
1857 	 * Defer operation if depth limit reached or if we are crossing a
1858 	 * PFS boundary.
1859 	 */
1860 	if (info->depth >= HAMMER2_RECOVERY_MAXDEPTH) {
1861 		struct hammer2_recovery_elm *elm;
1862 
1863 		elm = kmalloc(sizeof(*elm), M_HAMMER2, M_ZERO | M_WAITOK);
1864 		elm->chain = parent;
1865 		elm->sync_tid = sync_tid;
1866 		hammer2_chain_ref(parent);
1867 		TAILQ_INSERT_TAIL(&info->list, elm, entry);
1868 		/* unlocked by caller */
1869 
1870 		return(0);
1871 	}
1872 
1873 
1874 	/*
1875 	 * Recursive scan of the last flushed transaction only.  We are
1876 	 * doing this without pmp assignments so don't leave the chains
1877 	 * hanging around after we are done with them.
1878 	 */
1879 	cache_index = 0;
1880 	chain = hammer2_chain_scan(parent, NULL, &cache_index,
1881 				   HAMMER2_LOOKUP_NODATA);
1882 	while (chain) {
1883 		atomic_set_int(&chain->flags, HAMMER2_CHAIN_RELEASE);
1884 		if (chain->bref.mirror_tid > sync_tid) {
1885 			++info->depth;
1886 			error = hammer2_recovery_scan(hmp, chain,
1887 						      info, sync_tid);
1888 			--info->depth;
1889 			if (error)
1890 				cumulative_error = error;
1891 		}
1892 
1893 		/*
1894 		 * Flush the recovery at the PFS boundary to stage it for
1895 		 * the final flush of the super-root topology.
1896 		 */
1897 		if ((chain->bref.flags & HAMMER2_BREF_FLAG_PFSROOT) &&
1898 		    (chain->flags & HAMMER2_CHAIN_ONFLUSH)) {
1899 			hammer2_flush(chain, HAMMER2_FLUSH_TOP);
1900 		}
1901 		chain = hammer2_chain_scan(parent, chain, &cache_index,
1902 					   HAMMER2_LOOKUP_NODATA);
1903 	}
1904 
1905 	return cumulative_error;
1906 }
1907 
1908 /*
1909  * Sync a mount point; this is called on a per-mount basis from the
1910  * filesystem syncer process periodically and whenever a user issues
1911  * a sync.
1912  */
1913 int
1914 hammer2_vfs_sync(struct mount *mp, int waitfor)
1915 {
1916 	hammer2_xop_flush_t *xop;
1917 	struct hammer2_sync_info info;
1918 	hammer2_inode_t *iroot;
1919 	hammer2_pfs_t *pmp;
1920 	int flags;
1921 	int error;
1922 
1923 	pmp = MPTOPMP(mp);
1924 	iroot = pmp->iroot;
1925 	KKASSERT(iroot);
1926 	KKASSERT(iroot->pmp == pmp);
1927 
1928 	/*
1929 	 * We can't acquire locks on existing vnodes while in a transaction
1930 	 * without risking a deadlock.  This assumes that vfsync() can be
1931 	 * called without the vnode locked (which it can in DragonFly).
1932 	 * Otherwise we'd have to implement a multi-pass or flag the lock
1933 	 * failures and retry.
1934 	 *
1935 	 * The reclamation code interlocks with the sync list's token
1936 	 * (by removing the vnode from the scan list) before unlocking
1937 	 * the inode, giving us time to ref the inode.
1938 	 */
1939 	/*flags = VMSC_GETVP;*/
1940 	flags = 0;
1941 	if (waitfor & MNT_LAZY)
1942 		flags |= VMSC_ONEPASS;
1943 
1944 #if 0
1945 	/*
1946 	 * Preflush the vnodes using a normal transaction before interlocking
1947 	 * with a flush transaction.
1948 	 */
1949 	hammer2_trans_init(pmp, 0);
1950 	info.error = 0;
1951 	info.waitfor = MNT_NOWAIT;
1952 	vsyncscan(mp, flags | VMSC_NOWAIT, hammer2_sync_scan2, &info);
1953 	hammer2_trans_done(pmp);
1954 #endif
1955 
1956 	/*
1957 	 * Start our flush transaction.  This does not return until all
1958 	 * concurrent transactions have completed and will prevent any
1959 	 * new transactions from running concurrently, except for the
1960 	 * buffer cache transactions.
1961 	 *
1962 	 * For efficiency do an async pass before making sure with a
1963 	 * synchronous pass on all related buffer cache buffers.  It
1964 	 * should theoretically not be possible for any new file buffers
1965 	 * to be instantiated during this sequence.
1966 	 */
1967 	hammer2_trans_init(pmp, HAMMER2_TRANS_ISFLUSH |
1968 			        HAMMER2_TRANS_PREFLUSH);
1969 	hammer2_inode_run_unlinkq(pmp);
1970 
1971 	info.error = 0;
1972 	info.waitfor = MNT_NOWAIT;
1973 	vsyncscan(mp, flags | VMSC_NOWAIT, hammer2_sync_scan2, &info);
1974 	info.waitfor = MNT_WAIT;
1975 	vsyncscan(mp, flags, hammer2_sync_scan2, &info);
1976 
1977 	/*
1978 	 * Clear PREFLUSH.  This prevents (or asserts on) any new logical
1979 	 * buffer cache flushes which occur during the flush.  Device buffers
1980 	 * are not affected.
1981 	 */
1982 	hammer2_bioq_sync(pmp);
1983 	hammer2_trans_clear_preflush(pmp);
1984 
1985 	/*
1986 	 * Use the XOP interface to concurrently flush all nodes to
1987 	 * synchronize the PFSROOT subtopology to the media.  A standard
1988 	 * end-of-scan ENOENT error indicates cluster sufficiency.
1989 	 *
1990 	 * Note that this flush will not be visible on crash recovery until
1991 	 * we flush the super-root topology in the next loop.
1992 	 *
1993 	 * XXX For now wait for all flushes to complete.
1994 	 */
1995 	if (iroot) {
1996 		xop = hammer2_xop_alloc(iroot, HAMMER2_XOP_MODIFYING);
1997 		hammer2_xop_start(&xop->head, hammer2_inode_xop_flush);
1998 		error = hammer2_xop_collect(&xop->head,
1999 					    HAMMER2_XOP_COLLECT_WAITALL);
2000 		hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
2001 		if (error == ENOENT)
2002 			error = 0;
2003 	} else {
2004 		error = 0;
2005 	}
2006 	hammer2_trans_done(pmp);
2007 
2008 	return (error);
2009 }
2010 
2011 /*
2012  * Sync passes.
2013  *
2014  * Note that we ignore the tranasction mtid we got above.  Instead,
2015  * each vfsync below will ultimately get its own via TRANS_BUFCACHE
2016  * transactions.
2017  */
2018 static int
2019 hammer2_sync_scan2(struct mount *mp, struct vnode *vp, void *data)
2020 {
2021 	struct hammer2_sync_info *info = data;
2022 	hammer2_inode_t *ip;
2023 	int error;
2024 
2025 	/*
2026 	 * Degenerate cases.  Note that ip == NULL typically means the
2027 	 * syncer vnode itself and we don't want to vclrisdirty() in that
2028 	 * situation.
2029 	 */
2030 	ip = VTOI(vp);
2031 	if (ip == NULL) {
2032 		return(0);
2033 	}
2034 	if (vp->v_type == VNON || vp->v_type == VBAD) {
2035 		vclrisdirty(vp);
2036 		return(0);
2037 	}
2038 
2039 	/*
2040 	 * VOP_FSYNC will start a new transaction so replicate some code
2041 	 * here to do it inline (see hammer2_vop_fsync()).
2042 	 *
2043 	 * WARNING: The vfsync interacts with the buffer cache and might
2044 	 *          block, we can't hold the inode lock at that time.
2045 	 *	    However, we MUST ref ip before blocking to ensure that
2046 	 *	    it isn't ripped out from under us (since we do not
2047 	 *	    hold a lock on the vnode).
2048 	 */
2049 	hammer2_inode_ref(ip);
2050 	if ((ip->flags & HAMMER2_INODE_MODIFIED) ||
2051 	    !RB_EMPTY(&vp->v_rbdirty_tree)) {
2052 		vfsync(vp, info->waitfor, 1, NULL, NULL);
2053 		if (ip->flags & (HAMMER2_INODE_RESIZED |
2054 				 HAMMER2_INODE_MODIFIED)) {
2055 			hammer2_inode_lock(ip, 0);
2056 			hammer2_inode_chain_sync(ip);
2057 			hammer2_inode_unlock(ip);
2058 		}
2059 	}
2060 	if ((ip->flags & HAMMER2_INODE_MODIFIED) == 0 &&
2061 	    RB_EMPTY(&vp->v_rbdirty_tree)) {
2062 		vclrisdirty(vp);
2063 	}
2064 
2065 	hammer2_inode_drop(ip);
2066 #if 1
2067 	error = 0;
2068 	if (error)
2069 		info->error = error;
2070 #endif
2071 	return(0);
2072 }
2073 
2074 static
2075 int
2076 hammer2_vfs_vptofh(struct vnode *vp, struct fid *fhp)
2077 {
2078 	return (0);
2079 }
2080 
2081 static
2082 int
2083 hammer2_vfs_fhtovp(struct mount *mp, struct vnode *rootvp,
2084 	       struct fid *fhp, struct vnode **vpp)
2085 {
2086 	return (0);
2087 }
2088 
2089 static
2090 int
2091 hammer2_vfs_checkexp(struct mount *mp, struct sockaddr *nam,
2092 		 int *exflagsp, struct ucred **credanonp)
2093 {
2094 	return (0);
2095 }
2096 
2097 /*
2098  * Support code for hammer2_vfs_mount().  Read, verify, and install the volume
2099  * header into the HMP
2100  *
2101  * XXX read four volhdrs and use the one with the highest TID whos CRC
2102  *     matches.
2103  *
2104  * XXX check iCRCs.
2105  *
2106  * XXX For filesystems w/ less than 4 volhdrs, make sure to not write to
2107  *     nonexistant locations.
2108  *
2109  * XXX Record selected volhdr and ring updates to each of 4 volhdrs
2110  */
2111 static
2112 int
2113 hammer2_install_volume_header(hammer2_dev_t *hmp)
2114 {
2115 	hammer2_volume_data_t *vd;
2116 	struct buf *bp;
2117 	hammer2_crc32_t crc0, crc, bcrc0, bcrc;
2118 	int error_reported;
2119 	int error;
2120 	int valid;
2121 	int i;
2122 
2123 	error_reported = 0;
2124 	error = 0;
2125 	valid = 0;
2126 	bp = NULL;
2127 
2128 	/*
2129 	 * There are up to 4 copies of the volume header (syncs iterate
2130 	 * between them so there is no single master).  We don't trust the
2131 	 * volu_size field so we don't know precisely how large the filesystem
2132 	 * is, so depend on the OS to return an error if we go beyond the
2133 	 * block device's EOF.
2134 	 */
2135 	for (i = 0; i < HAMMER2_NUM_VOLHDRS; i++) {
2136 		error = bread(hmp->devvp, i * HAMMER2_ZONE_BYTES64,
2137 			      HAMMER2_VOLUME_BYTES, &bp);
2138 		if (error) {
2139 			brelse(bp);
2140 			bp = NULL;
2141 			continue;
2142 		}
2143 
2144 		vd = (struct hammer2_volume_data *) bp->b_data;
2145 		if ((vd->magic != HAMMER2_VOLUME_ID_HBO) &&
2146 		    (vd->magic != HAMMER2_VOLUME_ID_ABO)) {
2147 			brelse(bp);
2148 			bp = NULL;
2149 			continue;
2150 		}
2151 
2152 		if (vd->magic == HAMMER2_VOLUME_ID_ABO) {
2153 			/* XXX: Reversed-endianness filesystem */
2154 			kprintf("hammer2: reverse-endian filesystem detected");
2155 			brelse(bp);
2156 			bp = NULL;
2157 			continue;
2158 		}
2159 
2160 		crc = vd->icrc_sects[HAMMER2_VOL_ICRC_SECT0];
2161 		crc0 = hammer2_icrc32(bp->b_data + HAMMER2_VOLUME_ICRC0_OFF,
2162 				      HAMMER2_VOLUME_ICRC0_SIZE);
2163 		bcrc = vd->icrc_sects[HAMMER2_VOL_ICRC_SECT1];
2164 		bcrc0 = hammer2_icrc32(bp->b_data + HAMMER2_VOLUME_ICRC1_OFF,
2165 				       HAMMER2_VOLUME_ICRC1_SIZE);
2166 		if ((crc0 != crc) || (bcrc0 != bcrc)) {
2167 			kprintf("hammer2 volume header crc "
2168 				"mismatch copy #%d %08x/%08x\n",
2169 				i, crc0, crc);
2170 			error_reported = 1;
2171 			brelse(bp);
2172 			bp = NULL;
2173 			continue;
2174 		}
2175 		if (valid == 0 || hmp->voldata.mirror_tid < vd->mirror_tid) {
2176 			valid = 1;
2177 			hmp->voldata = *vd;
2178 			hmp->volhdrno = i;
2179 		}
2180 		brelse(bp);
2181 		bp = NULL;
2182 	}
2183 	if (valid) {
2184 		hmp->volsync = hmp->voldata;
2185 		error = 0;
2186 		if (error_reported || bootverbose || 1) { /* 1/DEBUG */
2187 			kprintf("hammer2: using volume header #%d\n",
2188 				hmp->volhdrno);
2189 		}
2190 	} else {
2191 		error = EINVAL;
2192 		kprintf("hammer2: no valid volume headers found!\n");
2193 	}
2194 	return (error);
2195 }
2196 
2197 /*
2198  * This handles hysteresis on regular file flushes.  Because the BIOs are
2199  * routed to a thread it is possible for an excessive number to build up
2200  * and cause long front-end stalls long before the runningbuffspace limit
2201  * is hit, so we implement hammer2_flush_pipe to control the
2202  * hysteresis.
2203  *
2204  * This is a particular problem when compression is used.
2205  */
2206 void
2207 hammer2_lwinprog_ref(hammer2_pfs_t *pmp)
2208 {
2209 	atomic_add_int(&pmp->count_lwinprog, 1);
2210 }
2211 
2212 void
2213 hammer2_lwinprog_drop(hammer2_pfs_t *pmp)
2214 {
2215 	int lwinprog;
2216 
2217 	lwinprog = atomic_fetchadd_int(&pmp->count_lwinprog, -1);
2218 	if ((lwinprog & HAMMER2_LWINPROG_WAITING) &&
2219 	    (lwinprog & HAMMER2_LWINPROG_MASK) <= hammer2_flush_pipe * 2 / 3) {
2220 		atomic_clear_int(&pmp->count_lwinprog,
2221 				 HAMMER2_LWINPROG_WAITING);
2222 		wakeup(&pmp->count_lwinprog);
2223 	}
2224 	if ((lwinprog & HAMMER2_LWINPROG_WAITING0) &&
2225 	    (lwinprog & HAMMER2_LWINPROG_MASK) <= 0) {
2226 		atomic_clear_int(&pmp->count_lwinprog,
2227 				 HAMMER2_LWINPROG_WAITING0);
2228 		wakeup(&pmp->count_lwinprog);
2229 	}
2230 }
2231 
2232 void
2233 hammer2_lwinprog_wait(hammer2_pfs_t *pmp, int flush_pipe)
2234 {
2235 	int lwinprog;
2236 	int lwflag = (flush_pipe) ? HAMMER2_LWINPROG_WAITING :
2237 				    HAMMER2_LWINPROG_WAITING0;
2238 
2239 	for (;;) {
2240 		lwinprog = pmp->count_lwinprog;
2241 		cpu_ccfence();
2242 		if ((lwinprog & HAMMER2_LWINPROG_MASK) <= flush_pipe)
2243 			break;
2244 		tsleep_interlock(&pmp->count_lwinprog, 0);
2245 		atomic_set_int(&pmp->count_lwinprog, lwflag);
2246 		lwinprog = pmp->count_lwinprog;
2247 		if ((lwinprog & HAMMER2_LWINPROG_MASK) <= flush_pipe)
2248 			break;
2249 		tsleep(&pmp->count_lwinprog, PINTERLOCKED, "h2wpipe", hz);
2250 	}
2251 }
2252 
2253 /*
2254  * Manage excessive memory resource use for chain and related
2255  * structures.
2256  */
2257 void
2258 hammer2_pfs_memory_wait(hammer2_pfs_t *pmp)
2259 {
2260 	uint32_t waiting;
2261 	uint32_t count;
2262 	uint32_t limit;
2263 #if 0
2264 	static int zzticks;
2265 #endif
2266 
2267 	/*
2268 	 * Atomic check condition and wait.  Also do an early speedup of
2269 	 * the syncer to try to avoid hitting the wait.
2270 	 */
2271 	for (;;) {
2272 		waiting = pmp->inmem_dirty_chains;
2273 		cpu_ccfence();
2274 		count = waiting & HAMMER2_DIRTYCHAIN_MASK;
2275 
2276 		limit = pmp->mp->mnt_nvnodelistsize / 10;
2277 		if (limit < hammer2_limit_dirty_chains)
2278 			limit = hammer2_limit_dirty_chains;
2279 		if (limit < 1000)
2280 			limit = 1000;
2281 
2282 #if 0
2283 		if ((int)(ticks - zzticks) > hz) {
2284 			zzticks = ticks;
2285 			kprintf("count %ld %ld\n", count, limit);
2286 		}
2287 #endif
2288 
2289 		/*
2290 		 * Block if there are too many dirty chains present, wait
2291 		 * for the flush to clean some out.
2292 		 */
2293 		if (count > limit) {
2294 			tsleep_interlock(&pmp->inmem_dirty_chains, 0);
2295 			if (atomic_cmpset_int(&pmp->inmem_dirty_chains,
2296 					       waiting,
2297 				       waiting | HAMMER2_DIRTYCHAIN_WAITING)) {
2298 				speedup_syncer(pmp->mp);
2299 				tsleep(&pmp->inmem_dirty_chains, PINTERLOCKED,
2300 				       "chnmem", hz);
2301 			}
2302 			continue;	/* loop on success or fail */
2303 		}
2304 
2305 		/*
2306 		 * Try to start an early flush before we are forced to block.
2307 		 */
2308 		if (count > limit * 7 / 10)
2309 			speedup_syncer(pmp->mp);
2310 		break;
2311 	}
2312 }
2313 
2314 void
2315 hammer2_pfs_memory_inc(hammer2_pfs_t *pmp)
2316 {
2317 	if (pmp) {
2318 		atomic_add_int(&pmp->inmem_dirty_chains, 1);
2319 	}
2320 }
2321 
2322 void
2323 hammer2_pfs_memory_wakeup(hammer2_pfs_t *pmp)
2324 {
2325 	uint32_t waiting;
2326 
2327 	if (pmp == NULL)
2328 		return;
2329 
2330 	for (;;) {
2331 		waiting = pmp->inmem_dirty_chains;
2332 		cpu_ccfence();
2333 		if (atomic_cmpset_int(&pmp->inmem_dirty_chains,
2334 				       waiting,
2335 				       (waiting - 1) &
2336 					~HAMMER2_DIRTYCHAIN_WAITING)) {
2337 			break;
2338 		}
2339 	}
2340 
2341 	if (waiting & HAMMER2_DIRTYCHAIN_WAITING)
2342 		wakeup(&pmp->inmem_dirty_chains);
2343 }
2344 
2345 /*
2346  * Debugging
2347  */
2348 void
2349 hammer2_dump_chain(hammer2_chain_t *chain, int tab, int *countp, char pfx)
2350 {
2351 	hammer2_chain_t *scan;
2352 	hammer2_chain_t *parent;
2353 
2354 	--*countp;
2355 	if (*countp == 0) {
2356 		kprintf("%*.*s...\n", tab, tab, "");
2357 		return;
2358 	}
2359 	if (*countp < 0)
2360 		return;
2361 	kprintf("%*.*s%c-chain %p.%d %016jx/%d mir=%016jx\n",
2362 		tab, tab, "", pfx,
2363 		chain, chain->bref.type,
2364 		chain->bref.key, chain->bref.keybits,
2365 		chain->bref.mirror_tid);
2366 
2367 	kprintf("%*.*s      [%08x] (%s) refs=%d",
2368 		tab, tab, "",
2369 		chain->flags,
2370 		((chain->bref.type == HAMMER2_BREF_TYPE_INODE &&
2371 		chain->data) ?  (char *)chain->data->ipdata.filename : "?"),
2372 		chain->refs);
2373 
2374 	parent = chain->parent;
2375 	if (parent)
2376 		kprintf("\n%*.*s      p=%p [pflags %08x prefs %d",
2377 			tab, tab, "",
2378 			parent, parent->flags, parent->refs);
2379 	if (RB_EMPTY(&chain->core.rbtree)) {
2380 		kprintf("\n");
2381 	} else {
2382 		kprintf(" {\n");
2383 		RB_FOREACH(scan, hammer2_chain_tree, &chain->core.rbtree)
2384 			hammer2_dump_chain(scan, tab + 4, countp, 'a');
2385 		if (chain->bref.type == HAMMER2_BREF_TYPE_INODE && chain->data)
2386 			kprintf("%*.*s}(%s)\n", tab, tab, "",
2387 				chain->data->ipdata.filename);
2388 		else
2389 			kprintf("%*.*s}\n", tab, tab, "");
2390 	}
2391 }
2392