xref: /dragonfly/sys/vfs/hammer2/hammer2_vfsops.c (revision 806343b9)
1 /*
2  * Copyright (c) 2011-2018 The DragonFly Project.  All rights reserved.
3  *
4  * This code is derived from software contributed to The DragonFly Project
5  * by Matthew Dillon <dillon@backplane.com>
6  * by Daniel Flores (GSOC 2013 - mentored by Matthew Dillon, compression)
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in
16  *    the documentation and/or other materials provided with the
17  *    distribution.
18  * 3. Neither the name of The DragonFly Project nor the names of its
19  *    contributors may be used to endorse or promote products derived
20  *    from this software without specific, prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
23  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
24  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
25  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
26  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
27  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
28  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
29  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
30  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
31  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
32  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/kernel.h>
38 #include <sys/nlookup.h>
39 #include <sys/vnode.h>
40 #include <sys/mount.h>
41 #include <sys/fcntl.h>
42 #include <sys/buf.h>
43 #include <sys/uuid.h>
44 #include <sys/vfsops.h>
45 #include <sys/sysctl.h>
46 #include <sys/socket.h>
47 #include <sys/objcache.h>
48 
49 #include <sys/proc.h>
50 #include <sys/namei.h>
51 #include <sys/mountctl.h>
52 #include <sys/dirent.h>
53 #include <sys/uio.h>
54 
55 #include <sys/mutex.h>
56 #include <sys/mutex2.h>
57 
58 #include "hammer2.h"
59 #include "hammer2_disk.h"
60 #include "hammer2_mount.h"
61 #include "hammer2_lz4.h"
62 
63 #include "zlib/hammer2_zlib.h"
64 
65 #define REPORT_REFS_ERRORS 1	/* XXX remove me */
66 
67 MALLOC_DEFINE(M_OBJCACHE, "objcache", "Object Cache");
68 
69 struct hammer2_sync_info {
70 	int error;
71 	int waitfor;
72 	int pass;
73 };
74 
75 TAILQ_HEAD(hammer2_mntlist, hammer2_dev);
76 static struct hammer2_mntlist hammer2_mntlist;
77 
78 struct hammer2_pfslist hammer2_pfslist;
79 struct hammer2_pfslist hammer2_spmplist;
80 struct lock hammer2_mntlk;
81 
82 int hammer2_supported_version = HAMMER2_VOL_VERSION_DEFAULT;
83 int hammer2_debug;
84 int hammer2_cluster_meta_read = 1;	/* physical read-ahead */
85 int hammer2_cluster_data_read = 4;	/* physical read-ahead */
86 int hammer2_cluster_write = 0;		/* physical write clustering */
87 int hammer2_dedup_enable = 1;
88 int hammer2_always_compress = 0;	/* always try to compress */
89 int hammer2_inval_enable = 0;
90 int hammer2_flush_pipe = 100;
91 int hammer2_dio_count;
92 int hammer2_dio_limit = 256;
93 int hammer2_bulkfree_tps = 5000;
94 long hammer2_chain_allocs;
95 long hammer2_chain_frees;
96 long hammer2_limit_dirty_chains;
97 long hammer2_limit_dirty_inodes;
98 long hammer2_count_modified_chains;
99 long hammer2_iod_invals;
100 long hammer2_iod_file_read;
101 long hammer2_iod_meta_read;
102 long hammer2_iod_indr_read;
103 long hammer2_iod_fmap_read;
104 long hammer2_iod_volu_read;
105 long hammer2_iod_file_write;
106 long hammer2_iod_file_wembed;
107 long hammer2_iod_file_wzero;
108 long hammer2_iod_file_wdedup;
109 long hammer2_iod_meta_write;
110 long hammer2_iod_indr_write;
111 long hammer2_iod_fmap_write;
112 long hammer2_iod_volu_write;
113 
114 MALLOC_DECLARE(M_HAMMER2_CBUFFER);
115 MALLOC_DEFINE(M_HAMMER2_CBUFFER, "HAMMER2-compbuffer",
116 		"Buffer used for compression.");
117 
118 MALLOC_DECLARE(M_HAMMER2_DEBUFFER);
119 MALLOC_DEFINE(M_HAMMER2_DEBUFFER, "HAMMER2-decompbuffer",
120 		"Buffer used for decompression.");
121 
122 SYSCTL_NODE(_vfs, OID_AUTO, hammer2, CTLFLAG_RW, 0, "HAMMER2 filesystem");
123 
124 SYSCTL_INT(_vfs_hammer2, OID_AUTO, supported_version, CTLFLAG_RD,
125 	   &hammer2_supported_version, 0, "");
126 SYSCTL_INT(_vfs_hammer2, OID_AUTO, debug, CTLFLAG_RW,
127 	   &hammer2_debug, 0, "");
128 SYSCTL_INT(_vfs_hammer2, OID_AUTO, cluster_meta_read, CTLFLAG_RW,
129 	   &hammer2_cluster_meta_read, 0, "");
130 SYSCTL_INT(_vfs_hammer2, OID_AUTO, cluster_data_read, CTLFLAG_RW,
131 	   &hammer2_cluster_data_read, 0, "");
132 SYSCTL_INT(_vfs_hammer2, OID_AUTO, cluster_write, CTLFLAG_RW,
133 	   &hammer2_cluster_write, 0, "");
134 SYSCTL_INT(_vfs_hammer2, OID_AUTO, dedup_enable, CTLFLAG_RW,
135 	   &hammer2_dedup_enable, 0, "");
136 SYSCTL_INT(_vfs_hammer2, OID_AUTO, always_compress, CTLFLAG_RW,
137 	   &hammer2_always_compress, 0, "");
138 SYSCTL_INT(_vfs_hammer2, OID_AUTO, inval_enable, CTLFLAG_RW,
139 	   &hammer2_inval_enable, 0, "");
140 SYSCTL_INT(_vfs_hammer2, OID_AUTO, flush_pipe, CTLFLAG_RW,
141 	   &hammer2_flush_pipe, 0, "");
142 SYSCTL_INT(_vfs_hammer2, OID_AUTO, bulkfree_tps, CTLFLAG_RW,
143 	   &hammer2_bulkfree_tps, 0, "");
144 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, chain_allocs, CTLFLAG_RW,
145 	   &hammer2_chain_allocs, 0, "");
146 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, chain_frees, CTLFLAG_RW,
147 	   &hammer2_chain_frees, 0, "");
148 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, limit_dirty_chains, CTLFLAG_RW,
149 	   &hammer2_limit_dirty_chains, 0, "");
150 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, limit_dirty_inodes, CTLFLAG_RW,
151 	   &hammer2_limit_dirty_inodes, 0, "");
152 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, count_modified_chains, CTLFLAG_RW,
153 	   &hammer2_count_modified_chains, 0, "");
154 SYSCTL_INT(_vfs_hammer2, OID_AUTO, dio_count, CTLFLAG_RD,
155 	   &hammer2_dio_count, 0, "");
156 SYSCTL_INT(_vfs_hammer2, OID_AUTO, dio_limit, CTLFLAG_RW,
157 	   &hammer2_dio_limit, 0, "");
158 
159 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_invals, CTLFLAG_RW,
160 	   &hammer2_iod_invals, 0, "");
161 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_file_read, CTLFLAG_RW,
162 	   &hammer2_iod_file_read, 0, "");
163 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_meta_read, CTLFLAG_RW,
164 	   &hammer2_iod_meta_read, 0, "");
165 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_indr_read, CTLFLAG_RW,
166 	   &hammer2_iod_indr_read, 0, "");
167 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_fmap_read, CTLFLAG_RW,
168 	   &hammer2_iod_fmap_read, 0, "");
169 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_volu_read, CTLFLAG_RW,
170 	   &hammer2_iod_volu_read, 0, "");
171 
172 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_file_write, CTLFLAG_RW,
173 	   &hammer2_iod_file_write, 0, "");
174 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_file_wembed, CTLFLAG_RW,
175 	   &hammer2_iod_file_wembed, 0, "");
176 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_file_wzero, CTLFLAG_RW,
177 	   &hammer2_iod_file_wzero, 0, "");
178 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_file_wdedup, CTLFLAG_RW,
179 	   &hammer2_iod_file_wdedup, 0, "");
180 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_meta_write, CTLFLAG_RW,
181 	   &hammer2_iod_meta_write, 0, "");
182 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_indr_write, CTLFLAG_RW,
183 	   &hammer2_iod_indr_write, 0, "");
184 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_fmap_write, CTLFLAG_RW,
185 	   &hammer2_iod_fmap_write, 0, "");
186 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_volu_write, CTLFLAG_RW,
187 	   &hammer2_iod_volu_write, 0, "");
188 
189 long hammer2_process_icrc32;
190 long hammer2_process_xxhash64;
191 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, process_icrc32, CTLFLAG_RW,
192 	   &hammer2_process_icrc32, 0, "");
193 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, process_xxhash64, CTLFLAG_RW,
194 	   &hammer2_process_xxhash64, 0, "");
195 
196 static int hammer2_vfs_init(struct vfsconf *conf);
197 static int hammer2_vfs_uninit(struct vfsconf *vfsp);
198 static int hammer2_vfs_mount(struct mount *mp, char *path, caddr_t data,
199 				struct ucred *cred);
200 static int hammer2_remount(hammer2_dev_t *, struct mount *, char *,
201 				struct vnode *, struct ucred *);
202 static int hammer2_recovery(hammer2_dev_t *hmp);
203 static int hammer2_vfs_unmount(struct mount *mp, int mntflags);
204 static int hammer2_vfs_root(struct mount *mp, struct vnode **vpp);
205 static int hammer2_vfs_statfs(struct mount *mp, struct statfs *sbp,
206 				struct ucred *cred);
207 static int hammer2_vfs_statvfs(struct mount *mp, struct statvfs *sbp,
208 				struct ucred *cred);
209 static int hammer2_vfs_fhtovp(struct mount *mp, struct vnode *rootvp,
210 				struct fid *fhp, struct vnode **vpp);
211 static int hammer2_vfs_vptofh(struct vnode *vp, struct fid *fhp);
212 static int hammer2_vfs_checkexp(struct mount *mp, struct sockaddr *nam,
213 				int *exflagsp, struct ucred **credanonp);
214 
215 static int hammer2_install_volume_header(hammer2_dev_t *hmp);
216 static int hammer2_sync_scan2(struct mount *mp, struct vnode *vp, void *data);
217 
218 static void hammer2_update_pmps(hammer2_dev_t *hmp);
219 
220 static void hammer2_mount_helper(struct mount *mp, hammer2_pfs_t *pmp);
221 static void hammer2_unmount_helper(struct mount *mp, hammer2_pfs_t *pmp,
222 				hammer2_dev_t *hmp);
223 static int hammer2_fixup_pfses(hammer2_dev_t *hmp);
224 
225 /*
226  * HAMMER2 vfs operations.
227  */
228 static struct vfsops hammer2_vfsops = {
229 	.vfs_init	= hammer2_vfs_init,
230 	.vfs_uninit	= hammer2_vfs_uninit,
231 	.vfs_sync	= hammer2_vfs_sync,
232 	.vfs_mount	= hammer2_vfs_mount,
233 	.vfs_unmount	= hammer2_vfs_unmount,
234 	.vfs_root 	= hammer2_vfs_root,
235 	.vfs_statfs	= hammer2_vfs_statfs,
236 	.vfs_statvfs	= hammer2_vfs_statvfs,
237 	.vfs_vget	= hammer2_vfs_vget,
238 	.vfs_vptofh	= hammer2_vfs_vptofh,
239 	.vfs_fhtovp	= hammer2_vfs_fhtovp,
240 	.vfs_checkexp	= hammer2_vfs_checkexp
241 };
242 
243 MALLOC_DEFINE(M_HAMMER2, "HAMMER2-mount", "");
244 
245 VFS_SET(hammer2_vfsops, hammer2, VFCF_MPSAFE);
246 MODULE_VERSION(hammer2, 1);
247 
248 static
249 int
250 hammer2_vfs_init(struct vfsconf *conf)
251 {
252 	static struct objcache_malloc_args margs_read;
253 	static struct objcache_malloc_args margs_write;
254 	static struct objcache_malloc_args margs_vop;
255 
256 	int error;
257 
258 	error = 0;
259 
260 	/*
261 	 * A large DIO cache is needed to retain dedup enablement masks.
262 	 * The bulkfree code clears related masks as part of the disk block
263 	 * recycling algorithm, preventing it from being used for a later
264 	 * dedup.
265 	 *
266 	 * NOTE: A large buffer cache can actually interfere with dedup
267 	 *	 operation because we dedup based on media physical buffers
268 	 *	 and not logical buffers.  Try to make the DIO case large
269 	 *	 enough to avoid this problem, but also cap it.
270 	 */
271 	hammer2_dio_limit = nbuf * 2;
272 	if (hammer2_dio_limit > 100000)
273 		hammer2_dio_limit = 100000;
274 
275 	if (HAMMER2_BLOCKREF_BYTES != sizeof(struct hammer2_blockref))
276 		error = EINVAL;
277 	if (HAMMER2_INODE_BYTES != sizeof(struct hammer2_inode_data))
278 		error = EINVAL;
279 	if (HAMMER2_VOLUME_BYTES != sizeof(struct hammer2_volume_data))
280 		error = EINVAL;
281 
282 	if (error)
283 		kprintf("HAMMER2 structure size mismatch; cannot continue.\n");
284 
285 	margs_read.objsize = 65536;
286 	margs_read.mtype = M_HAMMER2_DEBUFFER;
287 
288 	margs_write.objsize = 32768;
289 	margs_write.mtype = M_HAMMER2_CBUFFER;
290 
291 	margs_vop.objsize = sizeof(hammer2_xop_t);
292 	margs_vop.mtype = M_HAMMER2;
293 
294 	/*
295 	 * Note thaht for the XOPS cache we want backing store allocations
296 	 * to use M_ZERO.  This is not allowed in objcache_get() (to avoid
297 	 * confusion), so use the backing store function that does it.  This
298 	 * means that initial XOPS objects are zerod but REUSED objects are
299 	 * not.  So we are responsible for cleaning the object up sufficiently
300 	 * for our needs before objcache_put()ing it back (typically just the
301 	 * FIFO indices).
302 	 */
303 	cache_buffer_read = objcache_create(margs_read.mtype->ks_shortdesc,
304 				0, 1, NULL, NULL, NULL,
305 				objcache_malloc_alloc,
306 				objcache_malloc_free,
307 				&margs_read);
308 	cache_buffer_write = objcache_create(margs_write.mtype->ks_shortdesc,
309 				0, 1, NULL, NULL, NULL,
310 				objcache_malloc_alloc,
311 				objcache_malloc_free,
312 				&margs_write);
313 	cache_xops = objcache_create(margs_vop.mtype->ks_shortdesc,
314 				0, 1, NULL, NULL, NULL,
315 				objcache_malloc_alloc_zero,
316 				objcache_malloc_free,
317 				&margs_vop);
318 
319 
320 	lockinit(&hammer2_mntlk, "mntlk", 0, 0);
321 	TAILQ_INIT(&hammer2_mntlist);
322 	TAILQ_INIT(&hammer2_pfslist);
323 	TAILQ_INIT(&hammer2_spmplist);
324 
325 	hammer2_limit_dirty_chains = maxvnodes / 10;
326 	if (hammer2_limit_dirty_chains > HAMMER2_LIMIT_DIRTY_CHAINS)
327 		hammer2_limit_dirty_chains = HAMMER2_LIMIT_DIRTY_CHAINS;
328 
329 	hammer2_limit_dirty_inodes = maxvnodes / 100;
330 	if (hammer2_limit_dirty_inodes < 100)
331 		hammer2_limit_dirty_inodes = 100;
332 	if (hammer2_limit_dirty_inodes > HAMMER2_LIMIT_DIRTY_INODES)
333 		hammer2_limit_dirty_inodes = HAMMER2_LIMIT_DIRTY_INODES;
334 
335 	return (error);
336 }
337 
338 static
339 int
340 hammer2_vfs_uninit(struct vfsconf *vfsp __unused)
341 {
342 	objcache_destroy(cache_buffer_read);
343 	objcache_destroy(cache_buffer_write);
344 	objcache_destroy(cache_xops);
345 	return 0;
346 }
347 
348 /*
349  * Core PFS allocator.  Used to allocate or reference the pmp structure
350  * for PFS cluster mounts and the spmp structure for media (hmp) structures.
351  * The pmp can be passed in or loaded by this function using the chain and
352  * inode data.
353  *
354  * pmp->modify_tid tracks new modify_tid transaction ids for front-end
355  * transactions.  Note that synchronization does not use this field.
356  * (typically frontend operations and synchronization cannot run on the
357  * same PFS node at the same time).
358  *
359  * XXX check locking
360  */
361 hammer2_pfs_t *
362 hammer2_pfsalloc(hammer2_chain_t *chain,
363 		 const hammer2_inode_data_t *ripdata,
364 		 hammer2_tid_t modify_tid, hammer2_dev_t *force_local)
365 {
366 	hammer2_pfs_t *pmp;
367 	hammer2_inode_t *iroot;
368 	int count;
369 	int i;
370 	int j;
371 
372 	pmp = NULL;
373 
374 	/*
375 	 * Locate or create the PFS based on the cluster id.  If ripdata
376 	 * is NULL this is a spmp which is unique and is always allocated.
377 	 *
378 	 * If the device is mounted in local mode all PFSs are considered
379 	 * independent and not part of any cluster (for debugging only).
380 	 */
381 	if (ripdata) {
382 		TAILQ_FOREACH(pmp, &hammer2_pfslist, mntentry) {
383 			if (force_local != pmp->force_local)
384 				continue;
385 			if (force_local == NULL &&
386 			    bcmp(&pmp->pfs_clid, &ripdata->meta.pfs_clid,
387 				 sizeof(pmp->pfs_clid)) == 0) {
388 					break;
389 			} else if (force_local && pmp->pfs_names[0] &&
390 			    strcmp(pmp->pfs_names[0], ripdata->filename) == 0) {
391 					break;
392 			}
393 		}
394 	}
395 
396 	if (pmp == NULL) {
397 		pmp = kmalloc(sizeof(*pmp), M_HAMMER2, M_WAITOK | M_ZERO);
398 		pmp->force_local = force_local;
399 		hammer2_trans_manage_init(pmp);
400 		kmalloc_create(&pmp->minode, "HAMMER2-inodes");
401 		kmalloc_create(&pmp->mmsg, "HAMMER2-pfsmsg");
402 		lockinit(&pmp->lock, "pfslk", 0, 0);
403 		lockinit(&pmp->lock_nlink, "h2nlink", 0, 0);
404 		spin_init(&pmp->inum_spin, "hm2pfsalloc_inum");
405 		spin_init(&pmp->xop_spin, "h2xop");
406 		spin_init(&pmp->lru_spin, "h2lru");
407 		RB_INIT(&pmp->inum_tree);
408 		TAILQ_INIT(&pmp->sideq);
409 		TAILQ_INIT(&pmp->lru_list);
410 		spin_init(&pmp->list_spin, "hm2pfsalloc_list");
411 
412 		/*
413 		 * Distribute backend operations to threads
414 		 */
415 		for (i = 0; i < HAMMER2_XOPGROUPS; ++i)
416 			hammer2_xop_group_init(pmp, &pmp->xop_groups[i]);
417 
418 		/*
419 		 * Save the last media transaction id for the flusher.  Set
420 		 * initial
421 		 */
422 		if (ripdata) {
423 			pmp->pfs_clid = ripdata->meta.pfs_clid;
424 			TAILQ_INSERT_TAIL(&hammer2_pfslist, pmp, mntentry);
425 		} else {
426 			pmp->flags |= HAMMER2_PMPF_SPMP;
427 			TAILQ_INSERT_TAIL(&hammer2_spmplist, pmp, mntentry);
428 		}
429 
430 		/*
431 		 * The synchronization thread may start too early, make
432 		 * sure it stays frozen until we are ready to let it go.
433 		 * XXX
434 		 */
435 		/*
436 		pmp->primary_thr.flags = HAMMER2_THREAD_FROZEN |
437 					 HAMMER2_THREAD_REMASTER;
438 		*/
439 	}
440 
441 	/*
442 	 * Create the PFS's root inode and any missing XOP helper threads.
443 	 */
444 	if ((iroot = pmp->iroot) == NULL) {
445 		iroot = hammer2_inode_get(pmp, NULL, NULL, -1);
446 		if (ripdata)
447 			iroot->meta = ripdata->meta;
448 		pmp->iroot = iroot;
449 		hammer2_inode_ref(iroot);
450 		hammer2_inode_unlock(iroot);
451 	}
452 
453 	/*
454 	 * Stop here if no chain is passed in.
455 	 */
456 	if (chain == NULL)
457 		goto done;
458 
459 	/*
460 	 * When a chain is passed in we must add it to the PFS's root
461 	 * inode, update pmp->pfs_types[], and update the syncronization
462 	 * threads.
463 	 *
464 	 * When forcing local mode, mark the PFS as a MASTER regardless.
465 	 *
466 	 * At the moment empty spots can develop due to removals or failures.
467 	 * Ultimately we want to re-fill these spots but doing so might
468 	 * confused running code. XXX
469 	 */
470 	hammer2_inode_ref(iroot);
471 	hammer2_mtx_ex(&iroot->lock);
472 	j = iroot->cluster.nchains;
473 
474 	if (j == HAMMER2_MAXCLUSTER) {
475 		kprintf("hammer2_mount: cluster full!\n");
476 		/* XXX fatal error? */
477 	} else {
478 		KKASSERT(chain->pmp == NULL);
479 		chain->pmp = pmp;
480 		hammer2_chain_ref(chain);
481 		iroot->cluster.array[j].chain = chain;
482 		if (force_local)
483 			pmp->pfs_types[j] = HAMMER2_PFSTYPE_MASTER;
484 		else
485 			pmp->pfs_types[j] = ripdata->meta.pfs_type;
486 		pmp->pfs_names[j] = kstrdup(ripdata->filename, M_HAMMER2);
487 		pmp->pfs_hmps[j] = chain->hmp;
488 
489 		/*
490 		 * If the PFS is already mounted we must account
491 		 * for the mount_count here.
492 		 */
493 		if (pmp->mp)
494 			++chain->hmp->mount_count;
495 
496 		/*
497 		 * May have to fixup dirty chain tracking.  Previous
498 		 * pmp was NULL so nothing to undo.
499 		 */
500 		if (chain->flags & HAMMER2_CHAIN_MODIFIED)
501 			hammer2_pfs_memory_inc(pmp);
502 		++j;
503 	}
504 	iroot->cluster.nchains = j;
505 
506 	/*
507 	 * Update nmasters from any PFS inode which is part of the cluster.
508 	 * It is possible that this will result in a value which is too
509 	 * high.  MASTER PFSs are authoritative for pfs_nmasters and will
510 	 * override this value later on.
511 	 *
512 	 * (This informs us of masters that might not currently be
513 	 *  discoverable by this mount).
514 	 */
515 	if (ripdata && pmp->pfs_nmasters < ripdata->meta.pfs_nmasters) {
516 		pmp->pfs_nmasters = ripdata->meta.pfs_nmasters;
517 	}
518 
519 	/*
520 	 * Count visible masters.  Masters are usually added with
521 	 * ripdata->meta.pfs_nmasters set to 1.  This detects when there
522 	 * are more (XXX and must update the master inodes).
523 	 */
524 	count = 0;
525 	for (i = 0; i < iroot->cluster.nchains; ++i) {
526 		if (pmp->pfs_types[i] == HAMMER2_PFSTYPE_MASTER)
527 			++count;
528 	}
529 	if (pmp->pfs_nmasters < count)
530 		pmp->pfs_nmasters = count;
531 
532 	/*
533 	 * Create missing synchronization and support threads.
534 	 *
535 	 * Single-node masters (including snapshots) have nothing to
536 	 * synchronize and do not require this thread.
537 	 *
538 	 * Multi-node masters or any number of soft masters, slaves, copy,
539 	 * or other PFS types need the thread.
540 	 *
541 	 * Each thread is responsible for its particular cluster index.
542 	 * We use independent threads so stalls or mismatches related to
543 	 * any given target do not affect other targets.
544 	 */
545 	for (i = 0; i < iroot->cluster.nchains; ++i) {
546 		/*
547 		 * Single-node masters (including snapshots) have nothing
548 		 * to synchronize and will make direct xops support calls,
549 		 * thus they do not require this thread.
550 		 *
551 		 * Note that there can be thousands of snapshots.  We do not
552 		 * want to create thousands of threads.
553 		 */
554 		if (pmp->pfs_nmasters <= 1 &&
555 		    pmp->pfs_types[i] == HAMMER2_PFSTYPE_MASTER) {
556 			continue;
557 		}
558 
559 		/*
560 		 * Sync support thread
561 		 */
562 		if (pmp->sync_thrs[i].td == NULL) {
563 			hammer2_thr_create(&pmp->sync_thrs[i], pmp, NULL,
564 					   "h2nod", i, -1,
565 					   hammer2_primary_sync_thread);
566 		}
567 	}
568 
569 	/*
570 	 * Create missing Xop threads
571 	 *
572 	 * NOTE: We create helper threads for all mounted PFSs or any
573 	 *	 PFSs with 2+ nodes (so the sync thread can update them,
574 	 *	 even if not mounted).
575 	 */
576 	if (pmp->mp || iroot->cluster.nchains >= 2)
577 		hammer2_xop_helper_create(pmp);
578 
579 	hammer2_mtx_unlock(&iroot->lock);
580 	hammer2_inode_drop(iroot);
581 done:
582 	return pmp;
583 }
584 
585 /*
586  * Deallocate an element of a probed PFS.  If destroying and this is a
587  * MASTER, adjust nmasters.
588  *
589  * This function does not physically destroy the PFS element in its device
590  * under the super-root  (see hammer2_ioctl_pfs_delete()).
591  */
592 void
593 hammer2_pfsdealloc(hammer2_pfs_t *pmp, int clindex, int destroying)
594 {
595 	hammer2_inode_t *iroot;
596 	hammer2_chain_t *chain;
597 	int j;
598 
599 	/*
600 	 * Cleanup our reference on iroot.  iroot is (should) not be needed
601 	 * by the flush code.
602 	 */
603 	iroot = pmp->iroot;
604 	if (iroot) {
605 		/*
606 		 * Stop synchronizing
607 		 *
608 		 * XXX flush after acquiring the iroot lock.
609 		 * XXX clean out the cluster index from all inode structures.
610 		 */
611 		hammer2_thr_delete(&pmp->sync_thrs[clindex]);
612 
613 		/*
614 		 * Remove the cluster index from the group.  If destroying
615 		 * the PFS and this is a master, adjust pfs_nmasters.
616 		 */
617 		hammer2_mtx_ex(&iroot->lock);
618 		chain = iroot->cluster.array[clindex].chain;
619 		iroot->cluster.array[clindex].chain = NULL;
620 
621 		switch(pmp->pfs_types[clindex]) {
622 		case HAMMER2_PFSTYPE_MASTER:
623 			if (destroying && pmp->pfs_nmasters > 0)
624 				--pmp->pfs_nmasters;
625 			/* XXX adjust ripdata->meta.pfs_nmasters */
626 			break;
627 		default:
628 			break;
629 		}
630 		pmp->pfs_types[clindex] = HAMMER2_PFSTYPE_NONE;
631 
632 		hammer2_mtx_unlock(&iroot->lock);
633 
634 		/*
635 		 * Release the chain.
636 		 */
637 		if (chain) {
638 			atomic_set_int(&chain->flags, HAMMER2_CHAIN_RELEASE);
639 			hammer2_chain_drop(chain);
640 		}
641 
642 		/*
643 		 * Terminate all XOP threads for the cluster index.
644 		 */
645 		for (j = 0; j < HAMMER2_XOPGROUPS; ++j)
646 			hammer2_thr_delete(&pmp->xop_groups[j].thrs[clindex]);
647 	}
648 }
649 
650 /*
651  * Destroy a PFS, typically only occurs after the last mount on a device
652  * has gone away.
653  */
654 static void
655 hammer2_pfsfree(hammer2_pfs_t *pmp)
656 {
657 	hammer2_inode_t *iroot;
658 	hammer2_chain_t *chain;
659 	int i;
660 	int j;
661 
662 	/*
663 	 * Cleanup our reference on iroot.  iroot is (should) not be needed
664 	 * by the flush code.
665 	 */
666 	if (pmp->flags & HAMMER2_PMPF_SPMP)
667 		TAILQ_REMOVE(&hammer2_spmplist, pmp, mntentry);
668 	else
669 		TAILQ_REMOVE(&hammer2_pfslist, pmp, mntentry);
670 
671 	iroot = pmp->iroot;
672 	if (iroot) {
673 		for (i = 0; i < iroot->cluster.nchains; ++i) {
674 			hammer2_thr_delete(&pmp->sync_thrs[i]);
675 			for (j = 0; j < HAMMER2_XOPGROUPS; ++j)
676 				hammer2_thr_delete(&pmp->xop_groups[j].thrs[i]);
677 		}
678 #if REPORT_REFS_ERRORS
679 		if (pmp->iroot->refs != 1)
680 			kprintf("PMP->IROOT %p REFS WRONG %d\n",
681 				pmp->iroot, pmp->iroot->refs);
682 #else
683 		KKASSERT(pmp->iroot->refs == 1);
684 #endif
685 		/* ref for pmp->iroot */
686 		hammer2_inode_drop(pmp->iroot);
687 		pmp->iroot = NULL;
688 	}
689 
690 	/*
691 	 * Cleanup chains remaining on LRU list.
692 	 */
693 	hammer2_spin_ex(&pmp->lru_spin);
694 	while ((chain = TAILQ_FIRST(&pmp->lru_list)) != NULL) {
695 		KKASSERT(chain->flags & HAMMER2_CHAIN_ONLRU);
696 		atomic_add_int(&pmp->lru_count, -1);
697 		atomic_clear_int(&chain->flags, HAMMER2_CHAIN_ONLRU);
698 		TAILQ_REMOVE(&pmp->lru_list, chain, lru_node);
699 		hammer2_chain_ref(chain);
700 		hammer2_spin_unex(&pmp->lru_spin);
701 		atomic_set_int(&chain->flags, HAMMER2_CHAIN_RELEASE);
702 		hammer2_chain_drop(chain);
703 		hammer2_spin_ex(&pmp->lru_spin);
704 	}
705 	hammer2_spin_unex(&pmp->lru_spin);
706 
707 	/*
708 	 * Free remaining pmp resources
709 	 */
710 	kmalloc_destroy(&pmp->mmsg);
711 	kmalloc_destroy(&pmp->minode);
712 
713 	kfree(pmp, M_HAMMER2);
714 }
715 
716 /*
717  * Remove all references to hmp from the pfs list.  Any PFS which becomes
718  * empty is terminated and freed.
719  *
720  * XXX inefficient.
721  */
722 static void
723 hammer2_pfsfree_scan(hammer2_dev_t *hmp, int which)
724 {
725 	hammer2_pfs_t *pmp;
726 	hammer2_inode_t *iroot;
727 	hammer2_chain_t *rchain;
728 	int didfreeze;
729 	int i;
730 	int j;
731 	struct hammer2_pfslist *wlist;
732 
733 	if (which == 0)
734 		wlist = &hammer2_pfslist;
735 	else
736 		wlist = &hammer2_spmplist;
737 again:
738 	TAILQ_FOREACH(pmp, wlist, mntentry) {
739 		if ((iroot = pmp->iroot) == NULL)
740 			continue;
741 		hammer2_trans_init(pmp, HAMMER2_TRANS_ISFLUSH);
742 		hammer2_inode_run_sideq(pmp, 1);
743 		hammer2_bioq_sync(pmp);
744 		hammer2_trans_done(pmp, 0);
745 
746 		/*
747 		 * Determine if this PFS is affected.  If it is we must
748 		 * freeze all management threads and lock its iroot.
749 		 *
750 		 * Freezing a management thread forces it idle, operations
751 		 * in-progress will be aborted and it will have to start
752 		 * over again when unfrozen, or exit if told to exit.
753 		 */
754 		for (i = 0; i < HAMMER2_MAXCLUSTER; ++i) {
755 			if (pmp->pfs_hmps[i] == hmp)
756 				break;
757 		}
758 		if (i != HAMMER2_MAXCLUSTER) {
759 			/*
760 			 * Make sure all synchronization threads are locked
761 			 * down.
762 			 */
763 			for (i = 0; i < HAMMER2_MAXCLUSTER; ++i) {
764 				if (pmp->pfs_hmps[i] == NULL)
765 					continue;
766 				hammer2_thr_freeze_async(&pmp->sync_thrs[i]);
767 				for (j = 0; j < HAMMER2_XOPGROUPS; ++j) {
768 					hammer2_thr_freeze_async(
769 						&pmp->xop_groups[j].thrs[i]);
770 				}
771 			}
772 			for (i = 0; i < HAMMER2_MAXCLUSTER; ++i) {
773 				if (pmp->pfs_hmps[i] == NULL)
774 					continue;
775 				hammer2_thr_freeze(&pmp->sync_thrs[i]);
776 				for (j = 0; j < HAMMER2_XOPGROUPS; ++j) {
777 					hammer2_thr_freeze(
778 						&pmp->xop_groups[j].thrs[i]);
779 				}
780 			}
781 
782 			/*
783 			 * Lock the inode and clean out matching chains.
784 			 * Note that we cannot use hammer2_inode_lock_*()
785 			 * here because that would attempt to validate the
786 			 * cluster that we are in the middle of ripping
787 			 * apart.
788 			 *
789 			 * WARNING! We are working directly on the inodes
790 			 *	    embedded cluster.
791 			 */
792 			hammer2_mtx_ex(&iroot->lock);
793 
794 			/*
795 			 * Remove the chain from matching elements of the PFS.
796 			 */
797 			for (i = 0; i < HAMMER2_MAXCLUSTER; ++i) {
798 				if (pmp->pfs_hmps[i] != hmp)
799 					continue;
800 				hammer2_thr_delete(&pmp->sync_thrs[i]);
801 				for (j = 0; j < HAMMER2_XOPGROUPS; ++j) {
802 					hammer2_thr_delete(
803 						&pmp->xop_groups[j].thrs[i]);
804 				}
805 				rchain = iroot->cluster.array[i].chain;
806 				iroot->cluster.array[i].chain = NULL;
807 				pmp->pfs_types[i] = 0;
808 				if (pmp->pfs_names[i]) {
809 					kfree(pmp->pfs_names[i], M_HAMMER2);
810 					pmp->pfs_names[i] = NULL;
811 				}
812 				if (rchain) {
813 					hammer2_chain_drop(rchain);
814 					/* focus hint */
815 					if (iroot->cluster.focus == rchain)
816 						iroot->cluster.focus = NULL;
817 				}
818 				pmp->pfs_hmps[i] = NULL;
819 			}
820 			hammer2_mtx_unlock(&iroot->lock);
821 			didfreeze = 1;	/* remaster, unfreeze down below */
822 		} else {
823 			didfreeze = 0;
824 		}
825 
826 		/*
827 		 * Cleanup trailing chains.  Gaps may remain.
828 		 */
829 		for (i = HAMMER2_MAXCLUSTER - 1; i >= 0; --i) {
830 			if (pmp->pfs_hmps[i])
831 				break;
832 		}
833 		iroot->cluster.nchains = i + 1;
834 
835 		/*
836 		 * If the PMP has no elements remaining we can destroy it.
837 		 * (this will transition management threads from frozen->exit).
838 		 */
839 		if (iroot->cluster.nchains == 0) {
840 			/*
841 			 * If this was the hmp's spmp, we need to clean
842 			 * a little more stuff out.
843 			 */
844 			if (hmp->spmp == pmp) {
845 				hmp->spmp = NULL;
846 				hmp->vchain.pmp = NULL;
847 				hmp->fchain.pmp = NULL;
848 			}
849 
850 			/*
851 			 * Free the pmp and restart the loop
852 			 */
853 			hammer2_pfsfree(pmp);
854 			goto again;
855 		}
856 
857 		/*
858 		 * If elements still remain we need to set the REMASTER
859 		 * flag and unfreeze it.
860 		 */
861 		if (didfreeze) {
862 			for (i = 0; i < HAMMER2_MAXCLUSTER; ++i) {
863 				if (pmp->pfs_hmps[i] == NULL)
864 					continue;
865 				hammer2_thr_remaster(&pmp->sync_thrs[i]);
866 				hammer2_thr_unfreeze(&pmp->sync_thrs[i]);
867 				for (j = 0; j < HAMMER2_XOPGROUPS; ++j) {
868 					hammer2_thr_remaster(
869 						&pmp->xop_groups[j].thrs[i]);
870 					hammer2_thr_unfreeze(
871 						&pmp->xop_groups[j].thrs[i]);
872 				}
873 			}
874 		}
875 	}
876 }
877 
878 /*
879  * Mount or remount HAMMER2 fileystem from physical media
880  *
881  *	mountroot
882  *		mp		mount point structure
883  *		path		NULL
884  *		data		<unused>
885  *		cred		<unused>
886  *
887  *	mount
888  *		mp		mount point structure
889  *		path		path to mount point
890  *		data		pointer to argument structure in user space
891  *			volume	volume path (device@LABEL form)
892  *			hflags	user mount flags
893  *		cred		user credentials
894  *
895  * RETURNS:	0	Success
896  *		!0	error number
897  */
898 static
899 int
900 hammer2_vfs_mount(struct mount *mp, char *path, caddr_t data,
901 		  struct ucred *cred)
902 {
903 	struct hammer2_mount_info info;
904 	hammer2_pfs_t *pmp;
905 	hammer2_pfs_t *spmp;
906 	hammer2_dev_t *hmp;
907 	hammer2_dev_t *force_local;
908 	hammer2_key_t key_next;
909 	hammer2_key_t key_dummy;
910 	hammer2_key_t lhc;
911 	struct vnode *devvp;
912 	struct nlookupdata nd;
913 	hammer2_chain_t *parent;
914 	hammer2_chain_t *chain;
915 	const hammer2_inode_data_t *ripdata;
916 	hammer2_blockref_t bref;
917 	struct file *fp;
918 	char devstr[MNAMELEN];
919 	size_t size;
920 	size_t done;
921 	char *dev;
922 	char *label;
923 	int ronly = 1;
924 	int error;
925 	int i;
926 
927 	hmp = NULL;
928 	pmp = NULL;
929 	dev = NULL;
930 	label = NULL;
931 	devvp = NULL;
932 
933 	if (path == NULL) {
934 		/*
935 		 * Root mount
936 		 */
937 		bzero(&info, sizeof(info));
938 		info.cluster_fd = -1;
939 		ksnprintf(devstr, sizeof(devstr), "%s",
940 			  mp->mnt_stat.f_mntfromname);
941 		kprintf("hammer2_mount: root '%s'\n", devstr);
942 		done = strlen(devstr) + 1;
943 	} else {
944 		/*
945 		 * Non-root mount or updating a mount
946 		 */
947 		error = copyin(data, &info, sizeof(info));
948 		if (error)
949 			return (error);
950 
951 		error = copyinstr(info.volume, devstr, MNAMELEN - 1, &done);
952 		if (error)
953 			return (error);
954 		kprintf("hammer2_mount: '%s'\n", devstr);
955 	}
956 
957 	/*
958 	 * Extract device and label, automatically mount @BOOT, @ROOT, or @DATA
959 	 * if no label specified, based on the partition id.  Error out if no
960 	 * label or device (with partition id) is specified.  This is strictly
961 	 * a convenience to match the default label created by newfs_hammer2,
962 	 * our preference is that a label always be specified.
963 	 *
964 	 * NOTE: We allow 'mount @LABEL <blah>'... that is, a mount command
965 	 *	 that does not specify a device, as long as some H2 label
966 	 *	 has already been mounted from that device.  This makes
967 	 *	 mounting snapshots a lot easier.
968 	 */
969 	dev = devstr;
970 	label = strchr(devstr, '@');
971 	if (label && ((label + 1) - dev) > done) {
972 		kprintf("hammer2: mount: bad label %s/%zd\n",
973 			devstr, done);
974 		return (EINVAL);
975 	}
976 	if (label == NULL || label[1] == 0) {
977 		char slice;
978 
979 		if (label == NULL)
980 			label = devstr + strlen(devstr);
981 		else
982 			*label = '\0';		/* clean up trailing @ */
983 
984 		slice = label[-1];
985 		switch(slice) {
986 		case 'a':
987 			label = "BOOT";
988 			break;
989 		case 'd':
990 			label = "ROOT";
991 			break;
992 		default:
993 			label = "DATA";
994 			break;
995 		}
996 	} else {
997 		*label = '\0';
998 		label++;
999 	}
1000 
1001 	kprintf("hammer2_mount: dev=\"%s\" label=\"%s\" rdonly=%d\n",
1002 		dev, label, (mp->mnt_flag & MNT_RDONLY));
1003 
1004 	if (mp->mnt_flag & MNT_UPDATE) {
1005 		/*
1006 		 * Update mount.  Note that pmp->iroot->cluster is
1007 		 * an inode-embedded cluster and thus cannot be
1008 		 * directly locked.
1009 		 *
1010 		 * XXX HAMMER2 needs to implement NFS export via
1011 		 *     mountctl.
1012 		 */
1013 		hammer2_cluster_t *cluster;
1014 
1015 		pmp = MPTOPMP(mp);
1016 		pmp->hflags = info.hflags;
1017 		cluster = &pmp->iroot->cluster;
1018 		for (i = 0; i < cluster->nchains; ++i) {
1019 			if (cluster->array[i].chain == NULL)
1020 				continue;
1021 			hmp = cluster->array[i].chain->hmp;
1022 			devvp = hmp->devvp;
1023 			error = hammer2_remount(hmp, mp, path,
1024 						devvp, cred);
1025 			if (error)
1026 				break;
1027 		}
1028 
1029 		return error;
1030 	}
1031 
1032 	/*
1033 	 * HMP device mount
1034 	 *
1035 	 * If a path is specified and dev is not an empty string, lookup the
1036 	 * name and verify that it referes to a block device.
1037 	 *
1038 	 * If a path is specified and dev is an empty string we fall through
1039 	 * and locate the label in the hmp search.
1040 	 */
1041 	if (path && *dev != 0) {
1042 		error = nlookup_init(&nd, dev, UIO_SYSSPACE, NLC_FOLLOW);
1043 		if (error == 0)
1044 			error = nlookup(&nd);
1045 		if (error == 0)
1046 			error = cache_vref(&nd.nl_nch, nd.nl_cred, &devvp);
1047 		nlookup_done(&nd);
1048 	} else if (path == NULL) {
1049 		/* root mount */
1050 		cdev_t cdev = kgetdiskbyname(dev);
1051 		error = bdevvp(cdev, &devvp);
1052 		if (error)
1053 			kprintf("hammer2: cannot find '%s'\n", dev);
1054 	} else {
1055 		/*
1056 		 * We will locate the hmp using the label in the hmp loop.
1057 		 */
1058 		error = 0;
1059 	}
1060 
1061 	/*
1062 	 * Make sure its a block device.  Do not check to see if it is
1063 	 * already mounted until we determine that its a fresh H2 device.
1064 	 */
1065 	if (error == 0 && devvp) {
1066 		vn_isdisk(devvp, &error);
1067 	}
1068 
1069 	/*
1070 	 * Determine if the device has already been mounted.  After this
1071 	 * check hmp will be non-NULL if we are doing the second or more
1072 	 * hammer2 mounts from the same device.
1073 	 */
1074 	lockmgr(&hammer2_mntlk, LK_EXCLUSIVE);
1075 	if (devvp) {
1076 		/*
1077 		 * Match the device.  Due to the way devfs works,
1078 		 * we may not be able to directly match the vnode pointer,
1079 		 * so also check to see if the underlying device matches.
1080 		 */
1081 		TAILQ_FOREACH(hmp, &hammer2_mntlist, mntentry) {
1082 			if (hmp->devvp == devvp)
1083 				break;
1084 			if (devvp->v_rdev &&
1085 			    hmp->devvp->v_rdev == devvp->v_rdev) {
1086 				break;
1087 			}
1088 		}
1089 
1090 		/*
1091 		 * If no match this may be a fresh H2 mount, make sure
1092 		 * the device is not mounted on anything else.
1093 		 */
1094 		if (hmp == NULL)
1095 			error = vfs_mountedon(devvp);
1096 	} else if (error == 0) {
1097 		/*
1098 		 * Match the label to a pmp already probed.
1099 		 */
1100 		TAILQ_FOREACH(pmp, &hammer2_pfslist, mntentry) {
1101 			for (i = 0; i < HAMMER2_MAXCLUSTER; ++i) {
1102 				if (pmp->pfs_names[i] &&
1103 				    strcmp(pmp->pfs_names[i], label) == 0) {
1104 					hmp = pmp->pfs_hmps[i];
1105 					break;
1106 				}
1107 			}
1108 			if (hmp)
1109 				break;
1110 		}
1111 		if (hmp == NULL)
1112 			error = ENOENT;
1113 	}
1114 
1115 	/*
1116 	 * Open the device if this isn't a secondary mount and construct
1117 	 * the H2 device mount (hmp).
1118 	 */
1119 	if (hmp == NULL) {
1120 		hammer2_chain_t *schain;
1121 		hammer2_xid_t xid;
1122 		hammer2_xop_head_t xop;
1123 
1124 		if (error == 0 && vcount(devvp) > 0) {
1125 			kprintf("Primary device already has references\n");
1126 			error = EBUSY;
1127 		}
1128 
1129 		/*
1130 		 * Now open the device
1131 		 */
1132 		if (error == 0) {
1133 			ronly = ((mp->mnt_flag & MNT_RDONLY) != 0);
1134 			vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
1135 			error = vinvalbuf(devvp, V_SAVE, 0, 0);
1136 			if (error == 0) {
1137 				error = VOP_OPEN(devvp,
1138 					     (ronly ? FREAD : FREAD | FWRITE),
1139 					     FSCRED, NULL);
1140 			}
1141 			vn_unlock(devvp);
1142 		}
1143 		if (error && devvp) {
1144 			vrele(devvp);
1145 			devvp = NULL;
1146 		}
1147 		if (error) {
1148 			lockmgr(&hammer2_mntlk, LK_RELEASE);
1149 			return error;
1150 		}
1151 		hmp = kmalloc(sizeof(*hmp), M_HAMMER2, M_WAITOK | M_ZERO);
1152 		ksnprintf(hmp->devrepname, sizeof(hmp->devrepname), "%s", dev);
1153 		hmp->ronly = ronly;
1154 		hmp->devvp = devvp;
1155 		hmp->hflags = info.hflags & HMNT2_DEVFLAGS;
1156 		kmalloc_create(&hmp->mchain, "HAMMER2-chains");
1157 		TAILQ_INSERT_TAIL(&hammer2_mntlist, hmp, mntentry);
1158 		RB_INIT(&hmp->iotree);
1159 		spin_init(&hmp->io_spin, "hm2mount_io");
1160 		spin_init(&hmp->list_spin, "hm2mount_list");
1161 		TAILQ_INIT(&hmp->flushq);
1162 
1163 		lockinit(&hmp->vollk, "h2vol", 0, 0);
1164 		lockinit(&hmp->bulklk, "h2bulk", 0, 0);
1165 		lockinit(&hmp->bflock, "h2bflk", 0, 0);
1166 
1167 		/*
1168 		 * vchain setup. vchain.data is embedded.
1169 		 * vchain.refs is initialized and will never drop to 0.
1170 		 *
1171 		 * NOTE! voldata is not yet loaded.
1172 		 */
1173 		hmp->vchain.hmp = hmp;
1174 		hmp->vchain.refs = 1;
1175 		hmp->vchain.data = (void *)&hmp->voldata;
1176 		hmp->vchain.bref.type = HAMMER2_BREF_TYPE_VOLUME;
1177 		hmp->vchain.bref.data_off = 0 | HAMMER2_PBUFRADIX;
1178 		hmp->vchain.bref.mirror_tid = hmp->voldata.mirror_tid;
1179 
1180 		hammer2_chain_core_init(&hmp->vchain);
1181 		/* hmp->vchain.u.xxx is left NULL */
1182 
1183 		/*
1184 		 * fchain setup.  fchain.data is embedded.
1185 		 * fchain.refs is initialized and will never drop to 0.
1186 		 *
1187 		 * The data is not used but needs to be initialized to
1188 		 * pass assertion muster.  We use this chain primarily
1189 		 * as a placeholder for the freemap's top-level RBTREE
1190 		 * so it does not interfere with the volume's topology
1191 		 * RBTREE.
1192 		 */
1193 		hmp->fchain.hmp = hmp;
1194 		hmp->fchain.refs = 1;
1195 		hmp->fchain.data = (void *)&hmp->voldata.freemap_blockset;
1196 		hmp->fchain.bref.type = HAMMER2_BREF_TYPE_FREEMAP;
1197 		hmp->fchain.bref.data_off = 0 | HAMMER2_PBUFRADIX;
1198 		hmp->fchain.bref.mirror_tid = hmp->voldata.freemap_tid;
1199 		hmp->fchain.bref.methods =
1200 			HAMMER2_ENC_CHECK(HAMMER2_CHECK_FREEMAP) |
1201 			HAMMER2_ENC_COMP(HAMMER2_COMP_NONE);
1202 
1203 		hammer2_chain_core_init(&hmp->fchain);
1204 		/* hmp->fchain.u.xxx is left NULL */
1205 
1206 		/*
1207 		 * Install the volume header and initialize fields from
1208 		 * voldata.
1209 		 */
1210 		error = hammer2_install_volume_header(hmp);
1211 		if (error) {
1212 			hammer2_unmount_helper(mp, NULL, hmp);
1213 			lockmgr(&hammer2_mntlk, LK_RELEASE);
1214 			hammer2_vfs_unmount(mp, MNT_FORCE);
1215 			return error;
1216 		}
1217 
1218 		/*
1219 		 * Really important to get these right or flush will get
1220 		 * confused.
1221 		 */
1222 		hmp->spmp = hammer2_pfsalloc(NULL, NULL, 0, NULL);
1223 		spmp = hmp->spmp;
1224 
1225 		/*
1226 		 * Dummy-up vchain and fchain's modify_tid.  mirror_tid
1227 		 * is inherited from the volume header.
1228 		 */
1229 		xid = 0;
1230 		hmp->vchain.bref.mirror_tid = hmp->voldata.mirror_tid;
1231 		hmp->vchain.bref.modify_tid = hmp->vchain.bref.mirror_tid;
1232 		hmp->vchain.pmp = spmp;
1233 		hmp->fchain.bref.mirror_tid = hmp->voldata.freemap_tid;
1234 		hmp->fchain.bref.modify_tid = hmp->fchain.bref.mirror_tid;
1235 		hmp->fchain.pmp = spmp;
1236 
1237 		/*
1238 		 * First locate the super-root inode, which is key 0
1239 		 * relative to the volume header's blockset.
1240 		 *
1241 		 * Then locate the root inode by scanning the directory keyspace
1242 		 * represented by the label.
1243 		 */
1244 		parent = hammer2_chain_lookup_init(&hmp->vchain, 0);
1245 		schain = hammer2_chain_lookup(&parent, &key_dummy,
1246 				      HAMMER2_SROOT_KEY, HAMMER2_SROOT_KEY,
1247 				      &error, 0);
1248 		hammer2_chain_lookup_done(parent);
1249 		if (schain == NULL) {
1250 			kprintf("hammer2_mount: invalid super-root\n");
1251 			hammer2_unmount_helper(mp, NULL, hmp);
1252 			lockmgr(&hammer2_mntlk, LK_RELEASE);
1253 			hammer2_vfs_unmount(mp, MNT_FORCE);
1254 			return EINVAL;
1255 		}
1256 		if (schain->error) {
1257 			kprintf("hammer2_mount: error %s reading super-root\n",
1258 				hammer2_error_str(schain->error));
1259 			hammer2_chain_unlock(schain);
1260 			hammer2_chain_drop(schain);
1261 			schain = NULL;
1262 			hammer2_unmount_helper(mp, NULL, hmp);
1263 			lockmgr(&hammer2_mntlk, LK_RELEASE);
1264 			hammer2_vfs_unmount(mp, MNT_FORCE);
1265 			return EINVAL;
1266 		}
1267 
1268 		/*
1269 		 * The super-root always uses an inode_tid of 1 when
1270 		 * creating PFSs.
1271 		 */
1272 		spmp->inode_tid = 1;
1273 		spmp->modify_tid = schain->bref.modify_tid + 1;
1274 
1275 		/*
1276 		 * Sanity-check schain's pmp and finish initialization.
1277 		 * Any chain belonging to the super-root topology should
1278 		 * have a NULL pmp (not even set to spmp).
1279 		 */
1280 		ripdata = &hammer2_chain_rdata(schain)->ipdata;
1281 		KKASSERT(schain->pmp == NULL);
1282 		spmp->pfs_clid = ripdata->meta.pfs_clid;
1283 
1284 		/*
1285 		 * Replace the dummy spmp->iroot with a real one.  It's
1286 		 * easier to just do a wholesale replacement than to try
1287 		 * to update the chain and fixup the iroot fields.
1288 		 *
1289 		 * The returned inode is locked with the supplied cluster.
1290 		 */
1291 		hammer2_dummy_xop_from_chain(&xop, schain);
1292 		hammer2_inode_drop(spmp->iroot);
1293 		spmp->iroot = NULL;
1294 		spmp->iroot = hammer2_inode_get(spmp, NULL, &xop, -1);
1295 		spmp->spmp_hmp = hmp;
1296 		spmp->pfs_types[0] = ripdata->meta.pfs_type;
1297 		spmp->pfs_hmps[0] = hmp;
1298 		hammer2_inode_ref(spmp->iroot);
1299 		hammer2_inode_unlock(spmp->iroot);
1300 		hammer2_cluster_unlock(&xop.cluster);
1301 		hammer2_chain_drop(schain);
1302 		/* do not call hammer2_cluster_drop() on an embedded cluster */
1303 		schain = NULL;	/* now invalid */
1304 		/* leave spmp->iroot with one ref */
1305 
1306 		if ((mp->mnt_flag & MNT_RDONLY) == 0) {
1307 			error = hammer2_recovery(hmp);
1308 			if (error == 0)
1309 				error |= hammer2_fixup_pfses(hmp);
1310 			/* XXX do something with error */
1311 		}
1312 		hammer2_update_pmps(hmp);
1313 		hammer2_iocom_init(hmp);
1314 		hammer2_bulkfree_init(hmp);
1315 
1316 		/*
1317 		 * Ref the cluster management messaging descriptor.  The mount
1318 		 * program deals with the other end of the communications pipe.
1319 		 *
1320 		 * Root mounts typically do not supply one.
1321 		 */
1322 		if (info.cluster_fd >= 0) {
1323 			fp = holdfp(curthread, info.cluster_fd, -1);
1324 			if (fp) {
1325 				hammer2_cluster_reconnect(hmp, fp);
1326 			} else {
1327 				kprintf("hammer2_mount: bad cluster_fd!\n");
1328 			}
1329 		}
1330 	} else {
1331 		spmp = hmp->spmp;
1332 		if (info.hflags & HMNT2_DEVFLAGS) {
1333 			kprintf("hammer2: Warning: mount flags pertaining "
1334 				"to the whole device may only be specified "
1335 				"on the first mount of the device: %08x\n",
1336 				info.hflags & HMNT2_DEVFLAGS);
1337 		}
1338 	}
1339 
1340 	/*
1341 	 * Force local mount (disassociate all PFSs from their clusters).
1342 	 * Used primarily for debugging.
1343 	 */
1344 	force_local = (hmp->hflags & HMNT2_LOCAL) ? hmp : NULL;
1345 
1346 	/*
1347 	 * Lookup the mount point under the media-localized super-root.
1348 	 * Scanning hammer2_pfslist doesn't help us because it represents
1349 	 * PFS cluster ids which can aggregate several named PFSs together.
1350 	 *
1351 	 * cluster->pmp will incorrectly point to spmp and must be fixed
1352 	 * up later on.
1353 	 */
1354 	hammer2_inode_lock(spmp->iroot, 0);
1355 	parent = hammer2_inode_chain(spmp->iroot, 0, HAMMER2_RESOLVE_ALWAYS);
1356 	lhc = hammer2_dirhash(label, strlen(label));
1357 	chain = hammer2_chain_lookup(&parent, &key_next,
1358 				     lhc, lhc + HAMMER2_DIRHASH_LOMASK,
1359 				     &error, 0);
1360 	while (chain) {
1361 		if (chain->bref.type == HAMMER2_BREF_TYPE_INODE &&
1362 		    strcmp(label, chain->data->ipdata.filename) == 0) {
1363 			break;
1364 		}
1365 		chain = hammer2_chain_next(&parent, chain, &key_next,
1366 					    key_next,
1367 					    lhc + HAMMER2_DIRHASH_LOMASK,
1368 					    &error, 0);
1369 	}
1370 	if (parent) {
1371 		hammer2_chain_unlock(parent);
1372 		hammer2_chain_drop(parent);
1373 	}
1374 	hammer2_inode_unlock(spmp->iroot);
1375 
1376 	/*
1377 	 * PFS could not be found?
1378 	 */
1379 	if (chain == NULL) {
1380 		if (error)
1381 			kprintf("hammer2_mount: PFS label I/O error\n");
1382 		else
1383 			kprintf("hammer2_mount: PFS label not found\n");
1384 		hammer2_unmount_helper(mp, NULL, hmp);
1385 		lockmgr(&hammer2_mntlk, LK_RELEASE);
1386 		hammer2_vfs_unmount(mp, MNT_FORCE);
1387 
1388 		return EINVAL;
1389 	}
1390 
1391 	/*
1392 	 * Acquire the pmp structure (it should have already been allocated
1393 	 * via hammer2_update_pmps() so do not pass cluster in to add to
1394 	 * available chains).
1395 	 *
1396 	 * Check if the cluster has already been mounted.  A cluster can
1397 	 * only be mounted once, use null mounts to mount additional copies.
1398 	 */
1399 	if (chain->error) {
1400 		kprintf("hammer2_mount: PFS label I/O error\n");
1401 	} else {
1402 		ripdata = &chain->data->ipdata;
1403 		bref = chain->bref;
1404 		pmp = hammer2_pfsalloc(NULL, ripdata,
1405 				       bref.modify_tid, force_local);
1406 	}
1407 	hammer2_chain_unlock(chain);
1408 	hammer2_chain_drop(chain);
1409 
1410 	/*
1411 	 * Finish the mount
1412 	 */
1413         kprintf("hammer2_mount hmp=%p pmp=%p\n", hmp, pmp);
1414 
1415 	if (pmp->mp) {
1416 		kprintf("hammer2_mount: PFS already mounted!\n");
1417 		hammer2_unmount_helper(mp, NULL, hmp);
1418 		lockmgr(&hammer2_mntlk, LK_RELEASE);
1419 		hammer2_vfs_unmount(mp, MNT_FORCE);
1420 
1421 		return EBUSY;
1422 	}
1423 
1424 	pmp->hflags = info.hflags;
1425         mp->mnt_flag |= MNT_LOCAL;
1426         mp->mnt_kern_flag |= MNTK_ALL_MPSAFE;   /* all entry pts are SMP */
1427         mp->mnt_kern_flag |= MNTK_THR_SYNC;     /* new vsyncscan semantics */
1428 
1429         /*
1430          * required mount structure initializations
1431          */
1432         mp->mnt_stat.f_iosize = HAMMER2_PBUFSIZE;
1433         mp->mnt_stat.f_bsize = HAMMER2_PBUFSIZE;
1434 
1435         mp->mnt_vstat.f_frsize = HAMMER2_PBUFSIZE;
1436         mp->mnt_vstat.f_bsize = HAMMER2_PBUFSIZE;
1437 
1438         /*
1439          * Optional fields
1440          */
1441         mp->mnt_iosize_max = MAXPHYS;
1442 
1443 	/*
1444 	 * Connect up mount pointers.
1445 	 */
1446 	hammer2_mount_helper(mp, pmp);
1447 
1448         lockmgr(&hammer2_mntlk, LK_RELEASE);
1449 
1450 	/*
1451 	 * Finish setup
1452 	 */
1453 	vfs_getnewfsid(mp);
1454 	vfs_add_vnodeops(mp, &hammer2_vnode_vops, &mp->mnt_vn_norm_ops);
1455 	vfs_add_vnodeops(mp, &hammer2_spec_vops, &mp->mnt_vn_spec_ops);
1456 	vfs_add_vnodeops(mp, &hammer2_fifo_vops, &mp->mnt_vn_fifo_ops);
1457 
1458 	if (path) {
1459 		copyinstr(info.volume, mp->mnt_stat.f_mntfromname,
1460 			  MNAMELEN - 1, &size);
1461 		bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
1462 	} /* else root mount, already in there */
1463 
1464 	bzero(mp->mnt_stat.f_mntonname, sizeof(mp->mnt_stat.f_mntonname));
1465 	if (path) {
1466 		copyinstr(path, mp->mnt_stat.f_mntonname,
1467 			  sizeof(mp->mnt_stat.f_mntonname) - 1,
1468 			  &size);
1469 	} else {
1470 		/* root mount */
1471 		mp->mnt_stat.f_mntonname[0] = '/';
1472 	}
1473 
1474 	/*
1475 	 * Initial statfs to prime mnt_stat.
1476 	 */
1477 	hammer2_vfs_statfs(mp, &mp->mnt_stat, cred);
1478 
1479 	return 0;
1480 }
1481 
1482 /*
1483  * Scan PFSs under the super-root and create hammer2_pfs structures.
1484  */
1485 static
1486 void
1487 hammer2_update_pmps(hammer2_dev_t *hmp)
1488 {
1489 	const hammer2_inode_data_t *ripdata;
1490 	hammer2_chain_t *parent;
1491 	hammer2_chain_t *chain;
1492 	hammer2_blockref_t bref;
1493 	hammer2_dev_t *force_local;
1494 	hammer2_pfs_t *spmp;
1495 	hammer2_pfs_t *pmp;
1496 	hammer2_key_t key_next;
1497 	int error;
1498 
1499 	/*
1500 	 * Force local mount (disassociate all PFSs from their clusters).
1501 	 * Used primarily for debugging.
1502 	 */
1503 	force_local = (hmp->hflags & HMNT2_LOCAL) ? hmp : NULL;
1504 
1505 	/*
1506 	 * Lookup mount point under the media-localized super-root.
1507 	 *
1508 	 * cluster->pmp will incorrectly point to spmp and must be fixed
1509 	 * up later on.
1510 	 */
1511 	spmp = hmp->spmp;
1512 	hammer2_inode_lock(spmp->iroot, 0);
1513 	parent = hammer2_inode_chain(spmp->iroot, 0, HAMMER2_RESOLVE_ALWAYS);
1514 	chain = hammer2_chain_lookup(&parent, &key_next,
1515 					 HAMMER2_KEY_MIN, HAMMER2_KEY_MAX,
1516 					 &error, 0);
1517 	while (chain) {
1518 		if (chain->bref.type != HAMMER2_BREF_TYPE_INODE)
1519 			continue;
1520 		if (chain->error) {
1521 			kprintf("I/O error scanning PFS labels\n");
1522 		} else {
1523 			ripdata = &chain->data->ipdata;
1524 			bref = chain->bref;
1525 
1526 			pmp = hammer2_pfsalloc(chain, ripdata,
1527 					       bref.modify_tid, force_local);
1528 		}
1529 		chain = hammer2_chain_next(&parent, chain, &key_next,
1530 					   key_next, HAMMER2_KEY_MAX,
1531 					   &error, 0);
1532 	}
1533 	if (parent) {
1534 		hammer2_chain_unlock(parent);
1535 		hammer2_chain_drop(parent);
1536 	}
1537 	hammer2_inode_unlock(spmp->iroot);
1538 }
1539 
1540 static
1541 int
1542 hammer2_remount(hammer2_dev_t *hmp, struct mount *mp, char *path __unused,
1543 		struct vnode *devvp, struct ucred *cred)
1544 {
1545 	int error;
1546 
1547 	if (hmp->ronly && (mp->mnt_kern_flag & MNTK_WANTRDWR)) {
1548 		vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
1549 		VOP_OPEN(devvp, FREAD | FWRITE, FSCRED, NULL);
1550 		vn_unlock(devvp);
1551 		error = hammer2_recovery(hmp);
1552 		if (error == 0)
1553 			error |= hammer2_fixup_pfses(hmp);
1554 		vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
1555 		if (error == 0) {
1556 			VOP_CLOSE(devvp, FREAD, NULL);
1557 			hmp->ronly = 0;
1558 		} else {
1559 			VOP_CLOSE(devvp, FREAD | FWRITE, NULL);
1560 		}
1561 		vn_unlock(devvp);
1562 	} else {
1563 		error = 0;
1564 	}
1565 	return error;
1566 }
1567 
1568 static
1569 int
1570 hammer2_vfs_unmount(struct mount *mp, int mntflags)
1571 {
1572 	hammer2_pfs_t *pmp;
1573 	int flags;
1574 	int error = 0;
1575 
1576 	pmp = MPTOPMP(mp);
1577 
1578 	if (pmp == NULL)
1579 		return(0);
1580 
1581 	lockmgr(&hammer2_mntlk, LK_EXCLUSIVE);
1582 
1583 	/*
1584 	 * If mount initialization proceeded far enough we must flush
1585 	 * its vnodes and sync the underlying mount points.  Three syncs
1586 	 * are required to fully flush the filesystem (freemap updates lag
1587 	 * by one flush, and one extra for safety).
1588 	 */
1589 	if (mntflags & MNT_FORCE)
1590 		flags = FORCECLOSE;
1591 	else
1592 		flags = 0;
1593 	if (pmp->iroot) {
1594 		error = vflush(mp, 0, flags);
1595 		if (error)
1596 			goto failed;
1597 		hammer2_vfs_sync(mp, MNT_WAIT);
1598 		hammer2_vfs_sync(mp, MNT_WAIT);
1599 		hammer2_vfs_sync(mp, MNT_WAIT);
1600 	}
1601 
1602 	/*
1603 	 * Cleanup the frontend support XOPS threads
1604 	 */
1605 	hammer2_xop_helper_cleanup(pmp);
1606 
1607 	if (pmp->mp)
1608 		hammer2_unmount_helper(mp, pmp, NULL);
1609 
1610 	error = 0;
1611 failed:
1612 	lockmgr(&hammer2_mntlk, LK_RELEASE);
1613 
1614 	return (error);
1615 }
1616 
1617 /*
1618  * Mount helper, hook the system mount into our PFS.
1619  * The mount lock is held.
1620  *
1621  * We must bump the mount_count on related devices for any
1622  * mounted PFSs.
1623  */
1624 static
1625 void
1626 hammer2_mount_helper(struct mount *mp, hammer2_pfs_t *pmp)
1627 {
1628 	hammer2_cluster_t *cluster;
1629 	hammer2_chain_t *rchain;
1630 	int i;
1631 
1632         mp->mnt_data = (qaddr_t)pmp;
1633 	pmp->mp = mp;
1634 
1635 	/*
1636 	 * After pmp->mp is set we have to adjust hmp->mount_count.
1637 	 */
1638 	cluster = &pmp->iroot->cluster;
1639 	for (i = 0; i < cluster->nchains; ++i) {
1640 		rchain = cluster->array[i].chain;
1641 		if (rchain == NULL)
1642 			continue;
1643 		++rchain->hmp->mount_count;
1644 	}
1645 
1646 	/*
1647 	 * Create missing Xop threads
1648 	 */
1649 	hammer2_xop_helper_create(pmp);
1650 }
1651 
1652 /*
1653  * Mount helper, unhook the system mount from our PFS.
1654  * The mount lock is held.
1655  *
1656  * If hmp is supplied a mount responsible for being the first to open
1657  * the block device failed and the block device and all PFSs using the
1658  * block device must be cleaned up.
1659  *
1660  * If pmp is supplied multiple devices might be backing the PFS and each
1661  * must be disconnected.  This might not be the last PFS using some of the
1662  * underlying devices.  Also, we have to adjust our hmp->mount_count
1663  * accounting for the devices backing the pmp which is now undergoing an
1664  * unmount.
1665  */
1666 static
1667 void
1668 hammer2_unmount_helper(struct mount *mp, hammer2_pfs_t *pmp, hammer2_dev_t *hmp)
1669 {
1670 	hammer2_cluster_t *cluster;
1671 	hammer2_chain_t *rchain;
1672 	struct vnode *devvp;
1673 	int dumpcnt;
1674 	int ronly;
1675 	int i;
1676 
1677 	/*
1678 	 * If no device supplied this is a high-level unmount and we have to
1679 	 * to disconnect the mount, adjust mount_count, and locate devices
1680 	 * that might now have no mounts.
1681 	 */
1682 	if (pmp) {
1683 		KKASSERT(hmp == NULL);
1684 		KKASSERT((void *)(intptr_t)mp->mnt_data == pmp);
1685 		pmp->mp = NULL;
1686 		mp->mnt_data = NULL;
1687 
1688 		/*
1689 		 * After pmp->mp is cleared we have to account for
1690 		 * mount_count.
1691 		 */
1692 		cluster = &pmp->iroot->cluster;
1693 		for (i = 0; i < cluster->nchains; ++i) {
1694 			rchain = cluster->array[i].chain;
1695 			if (rchain == NULL)
1696 				continue;
1697 			--rchain->hmp->mount_count;
1698 			/* scrapping hmp now may invalidate the pmp */
1699 		}
1700 again:
1701 		TAILQ_FOREACH(hmp, &hammer2_mntlist, mntentry) {
1702 			if (hmp->mount_count == 0) {
1703 				hammer2_unmount_helper(NULL, NULL, hmp);
1704 				goto again;
1705 			}
1706 		}
1707 		return;
1708 	}
1709 
1710 	/*
1711 	 * Try to terminate the block device.  We can't terminate it if
1712 	 * there are still PFSs referencing it.
1713 	 */
1714 	if (hmp->mount_count)
1715 		return;
1716 
1717 	/*
1718 	 * Decomission the network before we start messing with the
1719 	 * device and PFS.
1720 	 */
1721 	hammer2_iocom_uninit(hmp);
1722 
1723 	hammer2_bulkfree_uninit(hmp);
1724 	hammer2_pfsfree_scan(hmp, 0);
1725 	hammer2_dev_exlock(hmp);	/* XXX order */
1726 
1727 	/*
1728 	 * Cycle the volume data lock as a safety (probably not needed any
1729 	 * more).  To ensure everything is out we need to flush at least
1730 	 * three times.  (1) The running of the sideq can dirty the
1731 	 * filesystem, (2) A normal flush can dirty the freemap, and
1732 	 * (3) ensure that the freemap is fully synchronized.
1733 	 *
1734 	 * The next mount's recovery scan can clean everything up but we want
1735 	 * to leave the filesystem in a 100% clean state on a normal unmount.
1736 	 */
1737 #if 0
1738 	hammer2_voldata_lock(hmp);
1739 	hammer2_voldata_unlock(hmp);
1740 #endif
1741 
1742 	/*
1743 	 * Flush whatever is left.  Unmounted but modified PFS's might still
1744 	 * have some dirty chains on them.
1745 	 */
1746 	hammer2_chain_lock(&hmp->vchain, HAMMER2_RESOLVE_ALWAYS);
1747 	hammer2_chain_lock(&hmp->fchain, HAMMER2_RESOLVE_ALWAYS);
1748 
1749 	if (hmp->fchain.flags & HAMMER2_CHAIN_FLUSH_MASK) {
1750 		hammer2_voldata_modify(hmp);
1751 		hammer2_flush(&hmp->fchain, HAMMER2_FLUSH_TOP |
1752 					    HAMMER2_FLUSH_ALL);
1753 	}
1754 	hammer2_chain_unlock(&hmp->fchain);
1755 
1756 	if (hmp->vchain.flags & HAMMER2_CHAIN_FLUSH_MASK) {
1757 		hammer2_flush(&hmp->vchain, HAMMER2_FLUSH_TOP |
1758 					    HAMMER2_FLUSH_ALL);
1759 	}
1760 	hammer2_chain_unlock(&hmp->vchain);
1761 
1762 	if ((hmp->vchain.flags | hmp->fchain.flags) &
1763 	    HAMMER2_CHAIN_FLUSH_MASK) {
1764 		kprintf("hammer2_unmount: chains left over "
1765 			"after final sync\n");
1766 		kprintf("    vchain %08x\n", hmp->vchain.flags);
1767 		kprintf("    fchain %08x\n", hmp->fchain.flags);
1768 
1769 		if (hammer2_debug & 0x0010)
1770 			Debugger("entered debugger");
1771 	}
1772 
1773 	hammer2_pfsfree_scan(hmp, 1);
1774 
1775 	KKASSERT(hmp->spmp == NULL);
1776 
1777 	/*
1778 	 * Finish up with the device vnode
1779 	 */
1780 	if ((devvp = hmp->devvp) != NULL) {
1781 		ronly = hmp->ronly;
1782 		vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
1783 		kprintf("hammer2_unmount(A): devvp %s rbdirty %p ronly=%d\n",
1784 			hmp->devrepname, RB_ROOT(&devvp->v_rbdirty_tree),
1785 			ronly);
1786 		vinvalbuf(devvp, (ronly ? 0 : V_SAVE), 0, 0);
1787 		kprintf("hammer2_unmount(B): devvp %s rbdirty %p\n",
1788 			hmp->devrepname, RB_ROOT(&devvp->v_rbdirty_tree));
1789 		hmp->devvp = NULL;
1790 		VOP_CLOSE(devvp, (ronly ? FREAD : FREAD|FWRITE), NULL);
1791 		vn_unlock(devvp);
1792 		vrele(devvp);
1793 		devvp = NULL;
1794 	}
1795 
1796 	/*
1797 	 * Clear vchain/fchain flags that might prevent final cleanup
1798 	 * of these chains.
1799 	 */
1800 	if (hmp->vchain.flags & HAMMER2_CHAIN_MODIFIED) {
1801 		atomic_add_long(&hammer2_count_modified_chains, -1);
1802 		atomic_clear_int(&hmp->vchain.flags, HAMMER2_CHAIN_MODIFIED);
1803 		hammer2_pfs_memory_wakeup(hmp->vchain.pmp);
1804 	}
1805 	if (hmp->vchain.flags & HAMMER2_CHAIN_UPDATE) {
1806 		atomic_clear_int(&hmp->vchain.flags, HAMMER2_CHAIN_UPDATE);
1807 	}
1808 
1809 	if (hmp->fchain.flags & HAMMER2_CHAIN_MODIFIED) {
1810 		atomic_add_long(&hammer2_count_modified_chains, -1);
1811 		atomic_clear_int(&hmp->fchain.flags, HAMMER2_CHAIN_MODIFIED);
1812 		hammer2_pfs_memory_wakeup(hmp->fchain.pmp);
1813 	}
1814 	if (hmp->fchain.flags & HAMMER2_CHAIN_UPDATE) {
1815 		atomic_clear_int(&hmp->fchain.flags, HAMMER2_CHAIN_UPDATE);
1816 	}
1817 
1818 	/*
1819 	 * Final drop of embedded freemap root chain to
1820 	 * clean up fchain.core (fchain structure is not
1821 	 * flagged ALLOCATED so it is cleaned out and then
1822 	 * left to rot).
1823 	 */
1824 	hammer2_chain_drop(&hmp->fchain);
1825 
1826 	/*
1827 	 * Final drop of embedded volume root chain to clean
1828 	 * up vchain.core (vchain structure is not flagged
1829 	 * ALLOCATED so it is cleaned out and then left to
1830 	 * rot).
1831 	 */
1832 	dumpcnt = 50;
1833 	hammer2_dump_chain(&hmp->vchain, 0, &dumpcnt, 'v', (u_int)-1);
1834 	dumpcnt = 50;
1835 	hammer2_dump_chain(&hmp->fchain, 0, &dumpcnt, 'f', (u_int)-1);
1836 	hammer2_dev_unlock(hmp);
1837 	hammer2_chain_drop(&hmp->vchain);
1838 
1839 	hammer2_io_cleanup(hmp, &hmp->iotree);
1840 	if (hmp->iofree_count) {
1841 		kprintf("io_cleanup: %d I/O's left hanging\n",
1842 			hmp->iofree_count);
1843 	}
1844 
1845 	TAILQ_REMOVE(&hammer2_mntlist, hmp, mntentry);
1846 	kmalloc_destroy(&hmp->mchain);
1847 	kfree(hmp, M_HAMMER2);
1848 }
1849 
1850 int
1851 hammer2_vfs_vget(struct mount *mp, struct vnode *dvp,
1852 		 ino_t ino, struct vnode **vpp)
1853 {
1854 	hammer2_xop_lookup_t *xop;
1855 	hammer2_pfs_t *pmp;
1856 	hammer2_inode_t *ip;
1857 	hammer2_tid_t inum;
1858 	int error;
1859 
1860 	inum = (hammer2_tid_t)ino & HAMMER2_DIRHASH_USERMSK;
1861 
1862 	error = 0;
1863 	pmp = MPTOPMP(mp);
1864 
1865 	/*
1866 	 * Easy if we already have it cached
1867 	 */
1868 	ip = hammer2_inode_lookup(pmp, inum);
1869 	if (ip) {
1870 		hammer2_inode_lock(ip, HAMMER2_RESOLVE_SHARED);
1871 		*vpp = hammer2_igetv(ip, &error);
1872 		hammer2_inode_unlock(ip);
1873 		hammer2_inode_drop(ip);		/* from lookup */
1874 
1875 		return error;
1876 	}
1877 
1878 	/*
1879 	 * Otherwise we have to find the inode
1880 	 */
1881 	xop = hammer2_xop_alloc(pmp->iroot, 0);
1882 	xop->lhc = inum;
1883 	hammer2_xop_start(&xop->head, &hammer2_lookup_desc);
1884 	error = hammer2_xop_collect(&xop->head, 0);
1885 
1886 	if (error == 0)
1887 		ip = hammer2_inode_get(pmp, NULL, &xop->head, -1);
1888 	hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
1889 
1890 	if (ip) {
1891 		*vpp = hammer2_igetv(ip, &error);
1892 		hammer2_inode_unlock(ip);
1893 	} else {
1894 		*vpp = NULL;
1895 		error = ENOENT;
1896 	}
1897 	return (error);
1898 }
1899 
1900 static
1901 int
1902 hammer2_vfs_root(struct mount *mp, struct vnode **vpp)
1903 {
1904 	hammer2_pfs_t *pmp;
1905 	struct vnode *vp;
1906 	int error;
1907 
1908 	pmp = MPTOPMP(mp);
1909 	if (pmp->iroot == NULL) {
1910 		kprintf("hammer2 (%s): no root inode\n",
1911 			mp->mnt_stat.f_mntfromname);
1912 		*vpp = NULL;
1913 		return EINVAL;
1914 	}
1915 
1916 	error = 0;
1917 	hammer2_inode_lock(pmp->iroot, HAMMER2_RESOLVE_SHARED);
1918 
1919 	while (pmp->inode_tid == 0) {
1920 		hammer2_xop_ipcluster_t *xop;
1921 		const hammer2_inode_meta_t *meta;
1922 
1923 		xop = hammer2_xop_alloc(pmp->iroot, HAMMER2_XOP_MODIFYING);
1924 		hammer2_xop_start(&xop->head, &hammer2_ipcluster_desc);
1925 		error = hammer2_xop_collect(&xop->head, 0);
1926 
1927 		if (error == 0) {
1928 			meta = &hammer2_xop_gdata(&xop->head)->ipdata.meta;
1929 			pmp->iroot->meta = *meta;
1930 			pmp->inode_tid = meta->pfs_inum + 1;
1931 			hammer2_xop_pdata(&xop->head);
1932 			/* meta invalid */
1933 
1934 			if (pmp->inode_tid < HAMMER2_INODE_START)
1935 				pmp->inode_tid = HAMMER2_INODE_START;
1936 			pmp->modify_tid =
1937 				xop->head.cluster.focus->bref.modify_tid + 1;
1938 #if 0
1939 			kprintf("PFS: Starting inode %jd\n",
1940 				(intmax_t)pmp->inode_tid);
1941 			kprintf("PMP focus good set nextino=%ld mod=%016jx\n",
1942 				pmp->inode_tid, pmp->modify_tid);
1943 #endif
1944 			wakeup(&pmp->iroot);
1945 
1946 			hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
1947 
1948 			/*
1949 			 * Prime the mount info.
1950 			 */
1951 			hammer2_vfs_statfs(mp, &mp->mnt_stat, NULL);
1952 			break;
1953 		}
1954 
1955 		/*
1956 		 * Loop, try again
1957 		 */
1958 		hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
1959 		hammer2_inode_unlock(pmp->iroot);
1960 		error = tsleep(&pmp->iroot, PCATCH, "h2root", hz);
1961 		hammer2_inode_lock(pmp->iroot, HAMMER2_RESOLVE_SHARED);
1962 		if (error == EINTR)
1963 			break;
1964 	}
1965 
1966 	if (error) {
1967 		hammer2_inode_unlock(pmp->iroot);
1968 		*vpp = NULL;
1969 	} else {
1970 		vp = hammer2_igetv(pmp->iroot, &error);
1971 		hammer2_inode_unlock(pmp->iroot);
1972 		*vpp = vp;
1973 	}
1974 
1975 	return (error);
1976 }
1977 
1978 /*
1979  * Filesystem status
1980  *
1981  * XXX incorporate ipdata->meta.inode_quota and data_quota
1982  */
1983 static
1984 int
1985 hammer2_vfs_statfs(struct mount *mp, struct statfs *sbp, struct ucred *cred)
1986 {
1987 	hammer2_pfs_t *pmp;
1988 	hammer2_dev_t *hmp;
1989 	hammer2_blockref_t bref;
1990 	struct statfs tmp;
1991 	int i;
1992 
1993 	/*
1994 	 * NOTE: iroot might not have validated the cluster yet.
1995 	 */
1996 	pmp = MPTOPMP(mp);
1997 
1998 	bzero(&tmp, sizeof(tmp));
1999 
2000 	for (i = 0; i < pmp->iroot->cluster.nchains; ++i) {
2001 		hmp = pmp->pfs_hmps[i];
2002 		if (hmp == NULL)
2003 			continue;
2004 		if (pmp->iroot->cluster.array[i].chain)
2005 			bref = pmp->iroot->cluster.array[i].chain->bref;
2006 		else
2007 			bzero(&bref, sizeof(bref));
2008 
2009 		tmp.f_files = bref.embed.stats.inode_count;
2010 		tmp.f_ffree = 0;
2011 		tmp.f_blocks = hmp->voldata.allocator_size /
2012 			       mp->mnt_vstat.f_bsize;
2013 		tmp.f_bfree = hmp->voldata.allocator_free /
2014 			      mp->mnt_vstat.f_bsize;
2015 		tmp.f_bavail = tmp.f_bfree;
2016 
2017 		if (cred && cred->cr_uid != 0) {
2018 			uint64_t adj;
2019 
2020 			/* 5% */
2021 			adj = hmp->free_reserved / mp->mnt_vstat.f_bsize;
2022 			tmp.f_blocks -= adj;
2023 			tmp.f_bfree -= adj;
2024 			tmp.f_bavail -= adj;
2025 		}
2026 
2027 		mp->mnt_stat.f_blocks = tmp.f_blocks;
2028 		mp->mnt_stat.f_bfree = tmp.f_bfree;
2029 		mp->mnt_stat.f_bavail = tmp.f_bavail;
2030 		mp->mnt_stat.f_files = tmp.f_files;
2031 		mp->mnt_stat.f_ffree = tmp.f_ffree;
2032 
2033 		*sbp = mp->mnt_stat;
2034 	}
2035 	return (0);
2036 }
2037 
2038 static
2039 int
2040 hammer2_vfs_statvfs(struct mount *mp, struct statvfs *sbp, struct ucred *cred)
2041 {
2042 	hammer2_pfs_t *pmp;
2043 	hammer2_dev_t *hmp;
2044 	hammer2_blockref_t bref;
2045 	struct statvfs tmp;
2046 	int i;
2047 
2048 	/*
2049 	 * NOTE: iroot might not have validated the cluster yet.
2050 	 */
2051 	pmp = MPTOPMP(mp);
2052 	bzero(&tmp, sizeof(tmp));
2053 
2054 	for (i = 0; i < pmp->iroot->cluster.nchains; ++i) {
2055 		hmp = pmp->pfs_hmps[i];
2056 		if (hmp == NULL)
2057 			continue;
2058 		if (pmp->iroot->cluster.array[i].chain)
2059 			bref = pmp->iroot->cluster.array[i].chain->bref;
2060 		else
2061 			bzero(&bref, sizeof(bref));
2062 
2063 		tmp.f_files = bref.embed.stats.inode_count;
2064 		tmp.f_ffree = 0;
2065 		tmp.f_blocks = hmp->voldata.allocator_size /
2066 			       mp->mnt_vstat.f_bsize;
2067 		tmp.f_bfree = hmp->voldata.allocator_free /
2068 			      mp->mnt_vstat.f_bsize;
2069 		tmp.f_bavail = tmp.f_bfree;
2070 
2071 		if (cred && cred->cr_uid != 0) {
2072 			uint64_t adj;
2073 
2074 			/* 5% */
2075 			adj = hmp->free_reserved / mp->mnt_vstat.f_bsize;
2076 			tmp.f_blocks -= adj;
2077 			tmp.f_bfree -= adj;
2078 			tmp.f_bavail -= adj;
2079 		}
2080 
2081 		mp->mnt_vstat.f_blocks = tmp.f_blocks;
2082 		mp->mnt_vstat.f_bfree = tmp.f_bfree;
2083 		mp->mnt_vstat.f_bavail = tmp.f_bavail;
2084 		mp->mnt_vstat.f_files = tmp.f_files;
2085 		mp->mnt_vstat.f_ffree = tmp.f_ffree;
2086 
2087 		*sbp = mp->mnt_vstat;
2088 	}
2089 	return (0);
2090 }
2091 
2092 /*
2093  * Mount-time recovery (RW mounts)
2094  *
2095  * Updates to the free block table are allowed to lag flushes by one
2096  * transaction.  In case of a crash, then on a fresh mount we must do an
2097  * incremental scan of the last committed transaction id and make sure that
2098  * all related blocks have been marked allocated.
2099  *
2100  * The super-root topology and each PFS has its own transaction id domain,
2101  * so we must track PFS boundary transitions.
2102  */
2103 struct hammer2_recovery_elm {
2104 	TAILQ_ENTRY(hammer2_recovery_elm) entry;
2105 	hammer2_chain_t *chain;
2106 	hammer2_tid_t sync_tid;
2107 };
2108 
2109 TAILQ_HEAD(hammer2_recovery_list, hammer2_recovery_elm);
2110 
2111 struct hammer2_recovery_info {
2112 	struct hammer2_recovery_list list;
2113 	hammer2_tid_t	mtid;
2114 	int	depth;
2115 };
2116 
2117 static int hammer2_recovery_scan(hammer2_dev_t *hmp,
2118 			hammer2_chain_t *parent,
2119 			struct hammer2_recovery_info *info,
2120 			hammer2_tid_t sync_tid);
2121 
2122 #define HAMMER2_RECOVERY_MAXDEPTH	10
2123 
2124 static
2125 int
2126 hammer2_recovery(hammer2_dev_t *hmp)
2127 {
2128 	struct hammer2_recovery_info info;
2129 	struct hammer2_recovery_elm *elm;
2130 	hammer2_chain_t *parent;
2131 	hammer2_tid_t sync_tid;
2132 	hammer2_tid_t mirror_tid;
2133 	int error;
2134 
2135 	hammer2_trans_init(hmp->spmp, 0);
2136 
2137 	sync_tid = hmp->voldata.freemap_tid;
2138 	mirror_tid = hmp->voldata.mirror_tid;
2139 
2140 	kprintf("hammer2 mount \"%s\": ", hmp->devrepname);
2141 	if (sync_tid >= mirror_tid) {
2142 		kprintf(" no recovery needed\n");
2143 	} else {
2144 		kprintf(" freemap recovery %016jx-%016jx\n",
2145 			sync_tid + 1, mirror_tid);
2146 	}
2147 
2148 	TAILQ_INIT(&info.list);
2149 	info.depth = 0;
2150 	parent = hammer2_chain_lookup_init(&hmp->vchain, 0);
2151 	error = hammer2_recovery_scan(hmp, parent, &info, sync_tid);
2152 	hammer2_chain_lookup_done(parent);
2153 
2154 	while ((elm = TAILQ_FIRST(&info.list)) != NULL) {
2155 		TAILQ_REMOVE(&info.list, elm, entry);
2156 		parent = elm->chain;
2157 		sync_tid = elm->sync_tid;
2158 		kfree(elm, M_HAMMER2);
2159 
2160 		hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS);
2161 		error |= hammer2_recovery_scan(hmp, parent, &info,
2162 					      hmp->voldata.freemap_tid);
2163 		hammer2_chain_unlock(parent);
2164 		hammer2_chain_drop(parent);	/* drop elm->chain ref */
2165 	}
2166 
2167 	hammer2_trans_done(hmp->spmp, 0);
2168 
2169 	return error;
2170 }
2171 
2172 static
2173 int
2174 hammer2_recovery_scan(hammer2_dev_t *hmp, hammer2_chain_t *parent,
2175 		      struct hammer2_recovery_info *info,
2176 		      hammer2_tid_t sync_tid)
2177 {
2178 	const hammer2_inode_data_t *ripdata;
2179 	hammer2_chain_t *chain;
2180 	hammer2_blockref_t bref;
2181 	int tmp_error;
2182 	int rup_error;
2183 	int error;
2184 	int first;
2185 
2186 	/*
2187 	 * Adjust freemap to ensure that the block(s) are marked allocated.
2188 	 */
2189 	if (parent->bref.type != HAMMER2_BREF_TYPE_VOLUME) {
2190 		hammer2_freemap_adjust(hmp, &parent->bref,
2191 				       HAMMER2_FREEMAP_DORECOVER);
2192 	}
2193 
2194 	/*
2195 	 * Check type for recursive scan
2196 	 */
2197 	switch(parent->bref.type) {
2198 	case HAMMER2_BREF_TYPE_VOLUME:
2199 		/* data already instantiated */
2200 		break;
2201 	case HAMMER2_BREF_TYPE_INODE:
2202 		/*
2203 		 * Must instantiate data for DIRECTDATA test and also
2204 		 * for recursion.
2205 		 */
2206 		hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS);
2207 		ripdata = &hammer2_chain_rdata(parent)->ipdata;
2208 		if (ripdata->meta.op_flags & HAMMER2_OPFLAG_DIRECTDATA) {
2209 			/* not applicable to recovery scan */
2210 			hammer2_chain_unlock(parent);
2211 			return 0;
2212 		}
2213 		hammer2_chain_unlock(parent);
2214 		break;
2215 	case HAMMER2_BREF_TYPE_INDIRECT:
2216 		/*
2217 		 * Must instantiate data for recursion
2218 		 */
2219 		hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS);
2220 		hammer2_chain_unlock(parent);
2221 		break;
2222 	case HAMMER2_BREF_TYPE_DIRENT:
2223 	case HAMMER2_BREF_TYPE_DATA:
2224 	case HAMMER2_BREF_TYPE_FREEMAP:
2225 	case HAMMER2_BREF_TYPE_FREEMAP_NODE:
2226 	case HAMMER2_BREF_TYPE_FREEMAP_LEAF:
2227 		/* not applicable to recovery scan */
2228 		return 0;
2229 		break;
2230 	default:
2231 		return HAMMER2_ERROR_BADBREF;
2232 	}
2233 
2234 	/*
2235 	 * Defer operation if depth limit reached or if we are crossing a
2236 	 * PFS boundary.
2237 	 */
2238 	if (info->depth >= HAMMER2_RECOVERY_MAXDEPTH) {
2239 		struct hammer2_recovery_elm *elm;
2240 
2241 		elm = kmalloc(sizeof(*elm), M_HAMMER2, M_ZERO | M_WAITOK);
2242 		elm->chain = parent;
2243 		elm->sync_tid = sync_tid;
2244 		hammer2_chain_ref(parent);
2245 		TAILQ_INSERT_TAIL(&info->list, elm, entry);
2246 		/* unlocked by caller */
2247 
2248 		return(0);
2249 	}
2250 
2251 
2252 	/*
2253 	 * Recursive scan of the last flushed transaction only.  We are
2254 	 * doing this without pmp assignments so don't leave the chains
2255 	 * hanging around after we are done with them.
2256 	 *
2257 	 * error	Cumulative error this level only
2258 	 * rup_error	Cumulative error for recursion
2259 	 * tmp_error	Specific non-cumulative recursion error
2260 	 */
2261 	chain = NULL;
2262 	first = 1;
2263 	rup_error = 0;
2264 	error = 0;
2265 
2266 	for (;;) {
2267 		error |= hammer2_chain_scan(parent, &chain, &bref,
2268 					    &first,
2269 					    HAMMER2_LOOKUP_NODATA);
2270 
2271 		/*
2272 		 * Problem during scan or EOF
2273 		 */
2274 		if (error)
2275 			break;
2276 
2277 		/*
2278 		 * If this is a leaf
2279 		 */
2280 		if (chain == NULL) {
2281 			if (bref.mirror_tid > sync_tid) {
2282 				hammer2_freemap_adjust(hmp, &bref,
2283 						     HAMMER2_FREEMAP_DORECOVER);
2284 			}
2285 			continue;
2286 		}
2287 
2288 		/*
2289 		 * This may or may not be a recursive node.
2290 		 */
2291 		atomic_set_int(&chain->flags, HAMMER2_CHAIN_RELEASE);
2292 		if (bref.mirror_tid > sync_tid) {
2293 			++info->depth;
2294 			tmp_error = hammer2_recovery_scan(hmp, chain,
2295 							   info, sync_tid);
2296 			--info->depth;
2297 		} else {
2298 			tmp_error = 0;
2299 		}
2300 
2301 		/*
2302 		 * Flush the recovery at the PFS boundary to stage it for
2303 		 * the final flush of the super-root topology.
2304 		 */
2305 		if (tmp_error == 0 &&
2306 		    (bref.flags & HAMMER2_BREF_FLAG_PFSROOT) &&
2307 		    (chain->flags & HAMMER2_CHAIN_ONFLUSH)) {
2308 			hammer2_flush(chain, HAMMER2_FLUSH_TOP |
2309 					     HAMMER2_FLUSH_ALL);
2310 		}
2311 		rup_error |= tmp_error;
2312 	}
2313 	return ((error | rup_error) & ~HAMMER2_ERROR_EOF);
2314 }
2315 
2316 /*
2317  * This fixes up an error introduced in earlier H2 implementations where
2318  * moving a PFS inode into an indirect block wound up causing the
2319  * HAMMER2_BREF_FLAG_PFSROOT flag in the bref to get cleared.
2320  */
2321 static
2322 int
2323 hammer2_fixup_pfses(hammer2_dev_t *hmp)
2324 {
2325 	const hammer2_inode_data_t *ripdata;
2326 	hammer2_chain_t *parent;
2327 	hammer2_chain_t *chain;
2328 	hammer2_key_t key_next;
2329 	hammer2_pfs_t *spmp;
2330 	int error;
2331 
2332 	error = 0;
2333 
2334 	/*
2335 	 * Lookup mount point under the media-localized super-root.
2336 	 *
2337 	 * cluster->pmp will incorrectly point to spmp and must be fixed
2338 	 * up later on.
2339 	 */
2340 	spmp = hmp->spmp;
2341 	hammer2_inode_lock(spmp->iroot, 0);
2342 	parent = hammer2_inode_chain(spmp->iroot, 0, HAMMER2_RESOLVE_ALWAYS);
2343 	chain = hammer2_chain_lookup(&parent, &key_next,
2344 					 HAMMER2_KEY_MIN, HAMMER2_KEY_MAX,
2345 					 &error, 0);
2346 	while (chain) {
2347 		if (chain->bref.type != HAMMER2_BREF_TYPE_INODE)
2348 			continue;
2349 		if (chain->error) {
2350 			kprintf("I/O error scanning PFS labels\n");
2351 			error |= chain->error;
2352 		} else if ((chain->bref.flags &
2353 			    HAMMER2_BREF_FLAG_PFSROOT) == 0) {
2354 			int error2;
2355 
2356 			ripdata = &chain->data->ipdata;
2357 			hammer2_trans_init(hmp->spmp, 0);
2358 			error2 = hammer2_chain_modify(chain,
2359 						      chain->bref.modify_tid,
2360 						      0, 0);
2361 			if (error2 == 0) {
2362 				kprintf("hammer2: Correct mis-flagged PFS %s\n",
2363 					ripdata->filename);
2364 				chain->bref.flags |= HAMMER2_BREF_FLAG_PFSROOT;
2365 			} else {
2366 				error |= error2;
2367 			}
2368 			hammer2_flush(chain, HAMMER2_FLUSH_TOP |
2369 					     HAMMER2_FLUSH_ALL);
2370 			hammer2_trans_done(hmp->spmp, 0);
2371 		}
2372 		chain = hammer2_chain_next(&parent, chain, &key_next,
2373 					   key_next, HAMMER2_KEY_MAX,
2374 					   &error, 0);
2375 	}
2376 	if (parent) {
2377 		hammer2_chain_unlock(parent);
2378 		hammer2_chain_drop(parent);
2379 	}
2380 	hammer2_inode_unlock(spmp->iroot);
2381 
2382 	return error;
2383 }
2384 
2385 /*
2386  * Sync a mount point; this is called periodically on a per-mount basis from
2387  * the filesystem syncer, and whenever a user issues a sync.
2388  */
2389 int
2390 hammer2_vfs_sync(struct mount *mp, int waitfor)
2391 {
2392 	hammer2_xop_flush_t *xop;
2393 	struct hammer2_sync_info info;
2394 	hammer2_inode_t *iroot;
2395 	hammer2_pfs_t *pmp;
2396 	int flags;
2397 	int error;
2398 
2399 	pmp = MPTOPMP(mp);
2400 	iroot = pmp->iroot;
2401 	KKASSERT(iroot);
2402 	KKASSERT(iroot->pmp == pmp);
2403 
2404 	/*
2405 	 * We can't acquire locks on existing vnodes while in a transaction
2406 	 * without risking a deadlock.  This assumes that vfsync() can be
2407 	 * called without the vnode locked (which it can in DragonFly).
2408 	 * Otherwise we'd have to implement a multi-pass or flag the lock
2409 	 * failures and retry.
2410 	 *
2411 	 * The reclamation code interlocks with the sync list's token
2412 	 * (by removing the vnode from the scan list) before unlocking
2413 	 * the inode, giving us time to ref the inode.
2414 	 */
2415 	/*flags = VMSC_GETVP;*/
2416 	flags = 0;
2417 	if (waitfor & MNT_LAZY)
2418 		flags |= VMSC_ONEPASS;
2419 
2420 	/*
2421 	 * Flush vnodes individually using a normal transaction to avoid
2422 	 * stalling any concurrent operations.  This will flush the related
2423 	 * buffer cache buffers and inodes to the media.
2424 	 *
2425 	 * For efficiency do an async pass before making sure with a
2426 	 * synchronous pass on all related buffer cache buffers.
2427 	 */
2428 	hammer2_trans_init(pmp, 0);
2429 
2430 	info.error = 0;
2431 
2432 	info.waitfor = MNT_NOWAIT;
2433 	info.pass = 1;
2434 	vsyncscan(mp, flags | VMSC_NOWAIT, hammer2_sync_scan2, &info);
2435 
2436 	/*
2437 	 * Now do two passes making sure we get everything.  The first pass
2438 	 * vfsync()s dirty vnodes.  The second pass waits for their I/O's
2439 	 * to finish and cleans up the dirty flag on the vnode.
2440 	 */
2441 	info.pass = 1;
2442 	info.waitfor = MNT_WAIT;
2443 	vsyncscan(mp, flags, hammer2_sync_scan2, &info);
2444 
2445 	info.pass = 2;
2446 	info.waitfor = MNT_WAIT;
2447 	vsyncscan(mp, flags, hammer2_sync_scan2, &info);
2448 
2449 	/*
2450 	 * We must also run the sideq to handle any disconnected inodes
2451 	 * as the vnode scan will not see these.
2452 	 */
2453 	hammer2_inode_run_sideq(pmp, 1);
2454 	hammer2_trans_done(pmp, 0);
2455 
2456 	/*
2457 	 * Start our flush transaction and flush the root topology down to
2458 	 * the inodes, but not the inodes themselves (which we already flushed
2459 	 * above).  Any concurrent activity effecting inode contents will not
2460 	 *
2461 	 * The flush sequence will
2462 	 *
2463 	 * NOTE! It is still possible for the paging code to push pages
2464 	 *	 out via a UIO_NOCOPY hammer2_vop_write() during the main
2465 	 *	 flush.
2466 	 */
2467 	hammer2_trans_init(pmp, HAMMER2_TRANS_ISFLUSH);
2468 
2469 	/*
2470 	 * sync dirty vnodes again while in the flush transaction.  This is
2471 	 * currently an expensive shim to makre sure the logical topology is
2472 	 * completely consistent before we flush the volume header.
2473 	 */
2474 	info.pass = 1;
2475 	info.waitfor = MNT_WAIT;
2476 	vsyncscan(mp, flags, hammer2_sync_scan2, &info);
2477 
2478 	info.pass = 2;
2479 	info.waitfor = MNT_WAIT;
2480 	vsyncscan(mp, flags, hammer2_sync_scan2, &info);
2481 
2482 	/*
2483 	 * Use the XOP interface to concurrently flush all nodes to
2484 	 * synchronize the PFSROOT subtopology to the media.  A standard
2485 	 * end-of-scan ENOENT error indicates cluster sufficiency.
2486 	 *
2487 	 * Note that this flush will not be visible on crash recovery until
2488 	 * we flush the super-root topology in the next loop.
2489 	 *
2490 	 * XXX For now wait for all flushes to complete.
2491 	 */
2492 	if (iroot) {
2493 		/*
2494 		 * If unmounting try to flush everything including any
2495 		 * sub-trees under inodes, just in case there is dangling
2496 		 * modified data, as a safety.  Otherwise just flush up to
2497 		 * the inodes in this stage.
2498 		 */
2499 		if (mp->mnt_kern_flag & MNTK_UNMOUNT) {
2500 			xop = hammer2_xop_alloc(iroot, HAMMER2_XOP_MODIFYING |
2501 						       HAMMER2_XOP_VOLHDR);
2502 		} else {
2503 			xop = hammer2_xop_alloc(iroot, HAMMER2_XOP_MODIFYING |
2504 						       HAMMER2_XOP_INODE_STOP |
2505 						       HAMMER2_XOP_VOLHDR);
2506 		}
2507 		hammer2_xop_start(&xop->head, &hammer2_inode_flush_desc);
2508 		error = hammer2_xop_collect(&xop->head,
2509 					    HAMMER2_XOP_COLLECT_WAITALL);
2510 		hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
2511 		if (error == HAMMER2_ERROR_ENOENT)
2512 			error = 0;
2513 		else
2514 			error = hammer2_error_to_errno(error);
2515 	} else {
2516 		error = 0;
2517 	}
2518 	hammer2_trans_done(pmp, 0);
2519 
2520 	return (error);
2521 }
2522 
2523 /*
2524  * Sync passes.
2525  *
2526  * Note that we ignore the tranasction mtid we got above.  Instead,
2527  * each vfsync below will ultimately get its own via TRANS_BUFCACHE
2528  * transactions.
2529  *
2530  * WARNING! The frontend might be waiting on chnmem (limit_dirty_chains)
2531  * while holding a vnode locked.  When this situation occurs we cannot
2532  * safely test whether it is ok to clear the dirty bit on the vnode.
2533  * However, we can still flush the inode's topology.
2534  */
2535 static int
2536 hammer2_sync_scan2(struct mount *mp, struct vnode *vp, void *data)
2537 {
2538 	struct hammer2_sync_info *info = data;
2539 	hammer2_inode_t *ip;
2540 	int error;
2541 
2542 	/*
2543 	 * Degenerate cases.  Note that ip == NULL typically means the
2544 	 * syncer vnode itself and we don't want to vclrisdirty() in that
2545 	 * situation.
2546 	 */
2547 	ip = VTOI(vp);
2548 	if (ip == NULL) {
2549 		return(0);
2550 	}
2551 	if (vp->v_type == VNON || vp->v_type == VBAD) {
2552 		vclrisdirty(vp);
2553 		return(0);
2554 	}
2555 
2556 	/*
2557 	 * Synchronize the buffer cche and inode meta-data to the backing
2558 	 * chain topology.
2559 	 *
2560 	 * vfsync is not necessarily synchronous, so it is best NOT to try
2561 	 * to flush the backing topology to media at this point.
2562 	 */
2563 	hammer2_inode_ref(ip);
2564 	if ((ip->flags & (HAMMER2_INODE_RESIZED|HAMMER2_INODE_MODIFIED)) ||
2565 	    !RB_EMPTY(&vp->v_rbdirty_tree)) {
2566 		if (info->pass == 1)
2567 			vfsync(vp, info->waitfor, 1, NULL, NULL);
2568 		else
2569 			bio_track_wait(&vp->v_track_write, 0, 0);
2570 	}
2571 	if (info->pass == 2 && (vp->v_flag & VISDIRTY)) {
2572 		/*
2573 		 * v_token is needed to interlock v_rbdirty_tree.
2574 		 */
2575 		lwkt_gettoken(&vp->v_token);
2576 		hammer2_inode_lock(ip, 0);
2577 		hammer2_inode_chain_sync(ip);
2578 		hammer2_inode_chain_flush(ip);
2579 		if ((ip->flags & (HAMMER2_INODE_MODIFIED |
2580 				  HAMMER2_INODE_RESIZED |
2581 				  HAMMER2_INODE_DIRTYDATA)) == 0 &&
2582 		    RB_EMPTY(&vp->v_rbdirty_tree) &&
2583 		    !bio_track_active(&vp->v_track_write)) {
2584 			vclrisdirty(vp);
2585 		}
2586 		hammer2_inode_unlock(ip);
2587 		lwkt_reltoken(&vp->v_token);
2588 	}
2589 	hammer2_inode_drop(ip);
2590 #if 1
2591 	error = 0;
2592 	if (error)
2593 		info->error = error;
2594 #endif
2595 	return(0);
2596 }
2597 
2598 static
2599 int
2600 hammer2_vfs_vptofh(struct vnode *vp, struct fid *fhp)
2601 {
2602 	hammer2_inode_t *ip;
2603 
2604 	KKASSERT(MAXFIDSZ >= 16);
2605 	ip = VTOI(vp);
2606 	fhp->fid_len = offsetof(struct fid, fid_data[16]);
2607 	fhp->fid_ext = 0;
2608 	((hammer2_tid_t *)fhp->fid_data)[0] = ip->meta.inum;
2609 	((hammer2_tid_t *)fhp->fid_data)[1] = 0;
2610 
2611 	return 0;
2612 }
2613 
2614 static
2615 int
2616 hammer2_vfs_fhtovp(struct mount *mp, struct vnode *rootvp,
2617 	       struct fid *fhp, struct vnode **vpp)
2618 {
2619 	hammer2_pfs_t *pmp;
2620 	hammer2_tid_t inum;
2621 	int error;
2622 
2623 	pmp = MPTOPMP(mp);
2624 	inum = ((hammer2_tid_t *)fhp->fid_data)[0] & HAMMER2_DIRHASH_USERMSK;
2625 	if (vpp) {
2626 		if (inum == 1)
2627 			error = hammer2_vfs_root(mp, vpp);
2628 		else
2629 			error = hammer2_vfs_vget(mp, NULL, inum, vpp);
2630 	} else {
2631 		error = 0;
2632 	}
2633 	if (error)
2634 		kprintf("fhtovp: %016jx -> %p, %d\n", inum, *vpp, error);
2635 	return error;
2636 }
2637 
2638 static
2639 int
2640 hammer2_vfs_checkexp(struct mount *mp, struct sockaddr *nam,
2641 		 int *exflagsp, struct ucred **credanonp)
2642 {
2643 	hammer2_pfs_t *pmp;
2644 	struct netcred *np;
2645 	int error;
2646 
2647 	pmp = MPTOPMP(mp);
2648 	np = vfs_export_lookup(mp, &pmp->export, nam);
2649 	if (np) {
2650 		*exflagsp = np->netc_exflags;
2651 		*credanonp = &np->netc_anon;
2652 		error = 0;
2653 	} else {
2654 		error = EACCES;
2655 	}
2656 	return error;
2657 }
2658 
2659 /*
2660  * Support code for hammer2_vfs_mount().  Read, verify, and install the volume
2661  * header into the HMP
2662  *
2663  * XXX read four volhdrs and use the one with the highest TID whos CRC
2664  *     matches.
2665  *
2666  * XXX check iCRCs.
2667  *
2668  * XXX For filesystems w/ less than 4 volhdrs, make sure to not write to
2669  *     nonexistant locations.
2670  *
2671  * XXX Record selected volhdr and ring updates to each of 4 volhdrs
2672  */
2673 static
2674 int
2675 hammer2_install_volume_header(hammer2_dev_t *hmp)
2676 {
2677 	hammer2_volume_data_t *vd;
2678 	struct buf *bp;
2679 	hammer2_crc32_t crc0, crc, bcrc0, bcrc;
2680 	int error_reported;
2681 	int error;
2682 	int valid;
2683 	int i;
2684 
2685 	error_reported = 0;
2686 	error = 0;
2687 	valid = 0;
2688 	bp = NULL;
2689 
2690 	/*
2691 	 * There are up to 4 copies of the volume header (syncs iterate
2692 	 * between them so there is no single master).  We don't trust the
2693 	 * volu_size field so we don't know precisely how large the filesystem
2694 	 * is, so depend on the OS to return an error if we go beyond the
2695 	 * block device's EOF.
2696 	 */
2697 	for (i = 0; i < HAMMER2_NUM_VOLHDRS; i++) {
2698 		error = bread(hmp->devvp, i * HAMMER2_ZONE_BYTES64,
2699 			      HAMMER2_VOLUME_BYTES, &bp);
2700 		if (error) {
2701 			brelse(bp);
2702 			bp = NULL;
2703 			continue;
2704 		}
2705 
2706 		vd = (struct hammer2_volume_data *) bp->b_data;
2707 		if ((vd->magic != HAMMER2_VOLUME_ID_HBO) &&
2708 		    (vd->magic != HAMMER2_VOLUME_ID_ABO)) {
2709 			brelse(bp);
2710 			bp = NULL;
2711 			continue;
2712 		}
2713 
2714 		if (vd->magic == HAMMER2_VOLUME_ID_ABO) {
2715 			/* XXX: Reversed-endianness filesystem */
2716 			kprintf("hammer2: reverse-endian filesystem detected");
2717 			brelse(bp);
2718 			bp = NULL;
2719 			continue;
2720 		}
2721 
2722 		crc = vd->icrc_sects[HAMMER2_VOL_ICRC_SECT0];
2723 		crc0 = hammer2_icrc32(bp->b_data + HAMMER2_VOLUME_ICRC0_OFF,
2724 				      HAMMER2_VOLUME_ICRC0_SIZE);
2725 		bcrc = vd->icrc_sects[HAMMER2_VOL_ICRC_SECT1];
2726 		bcrc0 = hammer2_icrc32(bp->b_data + HAMMER2_VOLUME_ICRC1_OFF,
2727 				       HAMMER2_VOLUME_ICRC1_SIZE);
2728 		if ((crc0 != crc) || (bcrc0 != bcrc)) {
2729 			kprintf("hammer2 volume header crc "
2730 				"mismatch copy #%d %08x/%08x\n",
2731 				i, crc0, crc);
2732 			error_reported = 1;
2733 			brelse(bp);
2734 			bp = NULL;
2735 			continue;
2736 		}
2737 		if (valid == 0 || hmp->voldata.mirror_tid < vd->mirror_tid) {
2738 			valid = 1;
2739 			hmp->voldata = *vd;
2740 			hmp->volhdrno = i;
2741 		}
2742 		brelse(bp);
2743 		bp = NULL;
2744 	}
2745 	if (valid) {
2746 		hmp->volsync = hmp->voldata;
2747 		hmp->free_reserved = hmp->voldata.allocator_size / 20;
2748 		error = 0;
2749 		if (error_reported || bootverbose || 1) { /* 1/DEBUG */
2750 			kprintf("hammer2: using volume header #%d\n",
2751 				hmp->volhdrno);
2752 		}
2753 	} else {
2754 		error = EINVAL;
2755 		kprintf("hammer2: no valid volume headers found!\n");
2756 	}
2757 	return (error);
2758 }
2759 
2760 /*
2761  * This handles hysteresis on regular file flushes.  Because the BIOs are
2762  * routed to a thread it is possible for an excessive number to build up
2763  * and cause long front-end stalls long before the runningbuffspace limit
2764  * is hit, so we implement hammer2_flush_pipe to control the
2765  * hysteresis.
2766  *
2767  * This is a particular problem when compression is used.
2768  */
2769 void
2770 hammer2_lwinprog_ref(hammer2_pfs_t *pmp)
2771 {
2772 	atomic_add_int(&pmp->count_lwinprog, 1);
2773 }
2774 
2775 void
2776 hammer2_lwinprog_drop(hammer2_pfs_t *pmp)
2777 {
2778 	int lwinprog;
2779 
2780 	lwinprog = atomic_fetchadd_int(&pmp->count_lwinprog, -1);
2781 	if ((lwinprog & HAMMER2_LWINPROG_WAITING) &&
2782 	    (lwinprog & HAMMER2_LWINPROG_MASK) <= hammer2_flush_pipe * 2 / 3) {
2783 		atomic_clear_int(&pmp->count_lwinprog,
2784 				 HAMMER2_LWINPROG_WAITING);
2785 		wakeup(&pmp->count_lwinprog);
2786 	}
2787 	if ((lwinprog & HAMMER2_LWINPROG_WAITING0) &&
2788 	    (lwinprog & HAMMER2_LWINPROG_MASK) <= 0) {
2789 		atomic_clear_int(&pmp->count_lwinprog,
2790 				 HAMMER2_LWINPROG_WAITING0);
2791 		wakeup(&pmp->count_lwinprog);
2792 	}
2793 }
2794 
2795 void
2796 hammer2_lwinprog_wait(hammer2_pfs_t *pmp, int flush_pipe)
2797 {
2798 	int lwinprog;
2799 	int lwflag = (flush_pipe) ? HAMMER2_LWINPROG_WAITING :
2800 				    HAMMER2_LWINPROG_WAITING0;
2801 
2802 	for (;;) {
2803 		lwinprog = pmp->count_lwinprog;
2804 		cpu_ccfence();
2805 		if ((lwinprog & HAMMER2_LWINPROG_MASK) <= flush_pipe)
2806 			break;
2807 		tsleep_interlock(&pmp->count_lwinprog, 0);
2808 		atomic_set_int(&pmp->count_lwinprog, lwflag);
2809 		lwinprog = pmp->count_lwinprog;
2810 		if ((lwinprog & HAMMER2_LWINPROG_MASK) <= flush_pipe)
2811 			break;
2812 		tsleep(&pmp->count_lwinprog, PINTERLOCKED, "h2wpipe", hz);
2813 	}
2814 }
2815 
2816 /*
2817  * Attempt to proactively fsync dirty vnodes if we have too many.  This
2818  * solves an issue where the kernel syncer thread can get seriously behind
2819  * when multiple user processes/threads are furiously modifying inodes.
2820  * This situation can occur on slow storage and is only limited by
2821  * kern.maxvnodes without the moderation code below.  It is made worse
2822  * when the device buffers underlying the modified inodes (which are clean)
2823  * get evicted before the flush can occur, forcing a re-read.
2824  *
2825  * We do not want sysads to feel that they have to torpedo kern.maxvnodes
2826  * to solve this problem, so we implement vfs.hammer2.limit_dirty_inodes
2827  * (per-mount-basis) and default it to something reasonable.
2828  */
2829 static void
2830 hammer2_pfs_moderate(hammer2_inode_t *ip, int always_moderate)
2831 {
2832 	hammer2_pfs_t *pmp = ip->pmp;
2833 	struct mount *mp = pmp->mp;
2834 
2835 	if (mp && vn_syncer_count(mp) > hammer2_limit_dirty_inodes) {
2836 		vn_syncer_one(mp);
2837 	}
2838 }
2839 
2840 /*
2841  * Manage excessive memory resource use for chain and related
2842  * structures.
2843  *
2844  * Called without any inode locks or transaction locks.  VNodes
2845  * might be locked by the kernel in the call stack.
2846  */
2847 void
2848 hammer2_pfs_memory_wait(hammer2_inode_t *ip, int always_moderate)
2849 {
2850 	hammer2_pfs_t *pmp = ip->pmp;
2851 	uint32_t waiting;
2852 	uint32_t count;
2853 	uint32_t limit;
2854 #if 0
2855 	static int zzticks;
2856 #endif
2857 
2858 	/*
2859 	 * Moderate the number of dirty inodes
2860 	 */
2861 	hammer2_pfs_moderate(ip, always_moderate);
2862 
2863 	/*
2864 	 * Atomic check condition and wait.  Also do an early speedup of
2865 	 * the syncer to try to avoid hitting the wait.
2866 	 */
2867 	for (;;) {
2868 		waiting = pmp->inmem_dirty_chains;
2869 		cpu_ccfence();
2870 		count = waiting & HAMMER2_DIRTYCHAIN_MASK;
2871 
2872 		limit = pmp->mp->mnt_nvnodelistsize / 10;
2873 		if (limit < hammer2_limit_dirty_chains)
2874 			limit = hammer2_limit_dirty_chains;
2875 		if (limit < 1000)
2876 			limit = 1000;
2877 
2878 #if 0
2879 		if ((int)(ticks - zzticks) > hz) {
2880 			zzticks = ticks;
2881 			kprintf("count %ld %ld\n", count, limit);
2882 		}
2883 #endif
2884 
2885 		/*
2886 		 * Block if there are too many dirty chains present, wait
2887 		 * for the flush to clean some out.
2888 		 */
2889 		if (count > limit) {
2890 			hammer2_pfs_moderate(ip, always_moderate);
2891 			tsleep_interlock(&pmp->inmem_dirty_chains, 0);
2892 			if (atomic_cmpset_int(&pmp->inmem_dirty_chains,
2893 					       waiting,
2894 				       waiting | HAMMER2_DIRTYCHAIN_WAITING)) {
2895 				if (ticks != pmp->speedup_ticks) {
2896 					pmp->speedup_ticks = ticks;
2897 					speedup_syncer(pmp->mp);
2898 				}
2899 				tsleep(&pmp->inmem_dirty_chains, PINTERLOCKED,
2900 				       "chnmem", hz);
2901 			}
2902 			continue;	/* loop on success or fail */
2903 		}
2904 
2905 		/*
2906 		 * Try to start an early flush before we are forced to block.
2907 		 */
2908 		if (count > limit * 5 / 10 &&
2909 		    ticks != pmp->speedup_ticks) {
2910 			pmp->speedup_ticks = ticks;
2911 			speedup_syncer(pmp->mp);
2912 		}
2913 		break;
2914 	}
2915 }
2916 
2917 void
2918 hammer2_pfs_memory_inc(hammer2_pfs_t *pmp)
2919 {
2920 	if (pmp) {
2921 		atomic_add_int(&pmp->inmem_dirty_chains, 1);
2922 	}
2923 }
2924 
2925 void
2926 hammer2_pfs_memory_wakeup(hammer2_pfs_t *pmp)
2927 {
2928 	uint32_t waiting;
2929 
2930 	if (pmp) {
2931 		waiting = atomic_fetchadd_int(&pmp->inmem_dirty_chains, -1);
2932 		/* don't need --waiting to test flag */
2933 		if (waiting & HAMMER2_DIRTYCHAIN_WAITING) {
2934 			atomic_clear_int(&pmp->inmem_dirty_chains,
2935 					 HAMMER2_DIRTYCHAIN_WAITING);
2936 			wakeup(&pmp->inmem_dirty_chains);
2937 		}
2938 	}
2939 }
2940 
2941 /*
2942  * Returns 0 if the filesystem has tons of free space
2943  * Returns 1 if the filesystem has less than 10% remaining
2944  * Returns 2 if the filesystem has less than 2%/5% (user/root) remaining.
2945  */
2946 int
2947 hammer2_vfs_enospace(hammer2_inode_t *ip, off_t bytes, struct ucred *cred)
2948 {
2949 	hammer2_pfs_t *pmp;
2950 	hammer2_dev_t *hmp;
2951 	hammer2_off_t free_reserved;
2952 	hammer2_off_t free_nominal;
2953 	int i;
2954 
2955 	pmp = ip->pmp;
2956 
2957 	if (pmp->free_ticks == 0 || pmp->free_ticks != ticks) {
2958 		free_reserved = HAMMER2_SEGSIZE;
2959 		free_nominal = 0x7FFFFFFFFFFFFFFFLLU;
2960 		for (i = 0; i < pmp->iroot->cluster.nchains; ++i) {
2961 			hmp = pmp->pfs_hmps[i];
2962 			if (hmp == NULL)
2963 				continue;
2964 			if (pmp->pfs_types[i] != HAMMER2_PFSTYPE_MASTER &&
2965 			    pmp->pfs_types[i] != HAMMER2_PFSTYPE_SOFT_MASTER)
2966 				continue;
2967 
2968 			if (free_nominal > hmp->voldata.allocator_free)
2969 				free_nominal = hmp->voldata.allocator_free;
2970 			if (free_reserved < hmp->free_reserved)
2971 				free_reserved = hmp->free_reserved;
2972 		}
2973 
2974 		/*
2975 		 * SMP races ok
2976 		 */
2977 		pmp->free_reserved = free_reserved;
2978 		pmp->free_nominal = free_nominal;
2979 		pmp->free_ticks = ticks;
2980 	} else {
2981 		free_reserved = pmp->free_reserved;
2982 		free_nominal = pmp->free_nominal;
2983 	}
2984 	if (cred && cred->cr_uid != 0) {
2985 		if ((int64_t)(free_nominal - bytes) <
2986 		    (int64_t)free_reserved) {
2987 			return 2;
2988 		}
2989 	} else {
2990 		if ((int64_t)(free_nominal - bytes) <
2991 		    (int64_t)free_reserved / 2) {
2992 			return 2;
2993 		}
2994 	}
2995 	if ((int64_t)(free_nominal - bytes) < (int64_t)free_reserved * 2)
2996 		return 1;
2997 	return 0;
2998 }
2999 
3000 /*
3001  * Debugging
3002  */
3003 void
3004 hammer2_dump_chain(hammer2_chain_t *chain, int tab, int *countp, char pfx,
3005 		   u_int flags)
3006 {
3007 	hammer2_chain_t *scan;
3008 	hammer2_chain_t *parent;
3009 
3010 	--*countp;
3011 	if (*countp == 0) {
3012 		kprintf("%*.*s...\n", tab, tab, "");
3013 		return;
3014 	}
3015 	if (*countp < 0)
3016 		return;
3017 	kprintf("%*.*s%c-chain %p.%d %016jx/%d mir=%016jx\n",
3018 		tab, tab, "", pfx,
3019 		chain, chain->bref.type,
3020 		chain->bref.key, chain->bref.keybits,
3021 		chain->bref.mirror_tid);
3022 
3023 	kprintf("%*.*s      [%08x] (%s) refs=%d",
3024 		tab, tab, "",
3025 		chain->flags,
3026 		((chain->bref.type == HAMMER2_BREF_TYPE_INODE &&
3027 		chain->data) ?  (char *)chain->data->ipdata.filename : "?"),
3028 		chain->refs);
3029 
3030 	parent = chain->parent;
3031 	if (parent)
3032 		kprintf("\n%*.*s      p=%p [pflags %08x prefs %d",
3033 			tab, tab, "",
3034 			parent, parent->flags, parent->refs);
3035 	if (RB_EMPTY(&chain->core.rbtree)) {
3036 		kprintf("\n");
3037 	} else {
3038 		kprintf(" {\n");
3039 		RB_FOREACH(scan, hammer2_chain_tree, &chain->core.rbtree) {
3040 			if ((scan->flags & flags) || flags == (u_int)-1) {
3041 				hammer2_dump_chain(scan, tab + 4, countp, 'a',
3042 						   flags);
3043 			}
3044 		}
3045 		if (chain->bref.type == HAMMER2_BREF_TYPE_INODE && chain->data)
3046 			kprintf("%*.*s}(%s)\n", tab, tab, "",
3047 				chain->data->ipdata.filename);
3048 		else
3049 			kprintf("%*.*s}\n", tab, tab, "");
3050 	}
3051 }
3052