xref: /dragonfly/sys/vfs/hammer2/hammer2_vfsops.c (revision 62dc643e)
1 /*
2  * Copyright (c) 2011-2015 The DragonFly Project.  All rights reserved.
3  *
4  * This code is derived from software contributed to The DragonFly Project
5  * by Matthew Dillon <dillon@backplane.com>
6  * by Daniel Flores (GSOC 2013 - mentored by Matthew Dillon, compression)
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in
16  *    the documentation and/or other materials provided with the
17  *    distribution.
18  * 3. Neither the name of The DragonFly Project nor the names of its
19  *    contributors may be used to endorse or promote products derived
20  *    from this software without specific, prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
23  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
24  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
25  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
26  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
27  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
28  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
29  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
30  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
31  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
32  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/kernel.h>
38 #include <sys/nlookup.h>
39 #include <sys/vnode.h>
40 #include <sys/mount.h>
41 #include <sys/fcntl.h>
42 #include <sys/buf.h>
43 #include <sys/uuid.h>
44 #include <sys/vfsops.h>
45 #include <sys/sysctl.h>
46 #include <sys/socket.h>
47 #include <sys/objcache.h>
48 
49 #include <sys/proc.h>
50 #include <sys/namei.h>
51 #include <sys/mountctl.h>
52 #include <sys/dirent.h>
53 #include <sys/uio.h>
54 
55 #include <sys/mutex.h>
56 #include <sys/mutex2.h>
57 
58 #include "hammer2.h"
59 #include "hammer2_disk.h"
60 #include "hammer2_mount.h"
61 #include "hammer2_lz4.h"
62 
63 #include "zlib/hammer2_zlib.h"
64 
65 #define REPORT_REFS_ERRORS 1	/* XXX remove me */
66 
67 MALLOC_DEFINE(M_OBJCACHE, "objcache", "Object Cache");
68 
69 struct hammer2_sync_info {
70 	int error;
71 	int waitfor;
72 };
73 
74 TAILQ_HEAD(hammer2_mntlist, hammer2_dev);
75 static struct hammer2_mntlist hammer2_mntlist;
76 
77 struct hammer2_pfslist hammer2_pfslist;
78 struct lock hammer2_mntlk;
79 
80 int hammer2_debug;
81 int hammer2_cluster_read = 4;		/* physical read-ahead */
82 int hammer2_cluster_write = 0;		/* bdwrite() so later inval works */
83 int hammer2_dedup_enable = 1;
84 int hammer2_inval_enable = 0;
85 int hammer2_flush_pipe = 100;
86 int hammer2_synchronous_flush = 1;
87 int hammer2_dio_count;
88 long hammer2_chain_allocs;
89 long hammer2_chain_frees;
90 long hammer2_limit_dirty_chains;
91 long hammer2_count_modified_chains;
92 long hammer2_iod_invals;
93 long hammer2_iod_file_read;
94 long hammer2_iod_meta_read;
95 long hammer2_iod_indr_read;
96 long hammer2_iod_fmap_read;
97 long hammer2_iod_volu_read;
98 long hammer2_iod_file_write;
99 long hammer2_iod_file_wembed;
100 long hammer2_iod_file_wzero;
101 long hammer2_iod_file_wdedup;
102 long hammer2_iod_meta_write;
103 long hammer2_iod_indr_write;
104 long hammer2_iod_fmap_write;
105 long hammer2_iod_volu_write;
106 
107 MALLOC_DECLARE(M_HAMMER2_CBUFFER);
108 MALLOC_DEFINE(M_HAMMER2_CBUFFER, "HAMMER2-compbuffer",
109 		"Buffer used for compression.");
110 
111 MALLOC_DECLARE(M_HAMMER2_DEBUFFER);
112 MALLOC_DEFINE(M_HAMMER2_DEBUFFER, "HAMMER2-decompbuffer",
113 		"Buffer used for decompression.");
114 
115 SYSCTL_NODE(_vfs, OID_AUTO, hammer2, CTLFLAG_RW, 0, "HAMMER2 filesystem");
116 
117 SYSCTL_INT(_vfs_hammer2, OID_AUTO, debug, CTLFLAG_RW,
118 	   &hammer2_debug, 0, "");
119 SYSCTL_INT(_vfs_hammer2, OID_AUTO, cluster_read, CTLFLAG_RW,
120 	   &hammer2_cluster_read, 0, "");
121 SYSCTL_INT(_vfs_hammer2, OID_AUTO, cluster_write, CTLFLAG_RW,
122 	   &hammer2_cluster_write, 0, "");
123 SYSCTL_INT(_vfs_hammer2, OID_AUTO, dedup_enable, CTLFLAG_RW,
124 	   &hammer2_dedup_enable, 0, "");
125 SYSCTL_INT(_vfs_hammer2, OID_AUTO, inval_enable, CTLFLAG_RW,
126 	   &hammer2_inval_enable, 0, "");
127 SYSCTL_INT(_vfs_hammer2, OID_AUTO, flush_pipe, CTLFLAG_RW,
128 	   &hammer2_flush_pipe, 0, "");
129 SYSCTL_INT(_vfs_hammer2, OID_AUTO, synchronous_flush, CTLFLAG_RW,
130 	   &hammer2_synchronous_flush, 0, "");
131 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, chain_allocs, CTLFLAG_RW,
132 	   &hammer2_chain_allocs, 0, "");
133 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, chain_frees, CTLFLAG_RW,
134 	   &hammer2_chain_frees, 0, "");
135 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, limit_dirty_chains, CTLFLAG_RW,
136 	   &hammer2_limit_dirty_chains, 0, "");
137 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, count_modified_chains, CTLFLAG_RW,
138 	   &hammer2_count_modified_chains, 0, "");
139 SYSCTL_INT(_vfs_hammer2, OID_AUTO, dio_count, CTLFLAG_RD,
140 	   &hammer2_dio_count, 0, "");
141 
142 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_invals, CTLFLAG_RW,
143 	   &hammer2_iod_invals, 0, "");
144 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_file_read, CTLFLAG_RW,
145 	   &hammer2_iod_file_read, 0, "");
146 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_meta_read, CTLFLAG_RW,
147 	   &hammer2_iod_meta_read, 0, "");
148 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_indr_read, CTLFLAG_RW,
149 	   &hammer2_iod_indr_read, 0, "");
150 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_fmap_read, CTLFLAG_RW,
151 	   &hammer2_iod_fmap_read, 0, "");
152 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_volu_read, CTLFLAG_RW,
153 	   &hammer2_iod_volu_read, 0, "");
154 
155 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_file_write, CTLFLAG_RW,
156 	   &hammer2_iod_file_write, 0, "");
157 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_file_wembed, CTLFLAG_RW,
158 	   &hammer2_iod_file_wembed, 0, "");
159 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_file_wzero, CTLFLAG_RW,
160 	   &hammer2_iod_file_wzero, 0, "");
161 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_file_wdedup, CTLFLAG_RW,
162 	   &hammer2_iod_file_wdedup, 0, "");
163 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_meta_write, CTLFLAG_RW,
164 	   &hammer2_iod_meta_write, 0, "");
165 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_indr_write, CTLFLAG_RW,
166 	   &hammer2_iod_indr_write, 0, "");
167 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_fmap_write, CTLFLAG_RW,
168 	   &hammer2_iod_fmap_write, 0, "");
169 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_volu_write, CTLFLAG_RW,
170 	   &hammer2_iod_volu_write, 0, "");
171 
172 long hammer2_check_icrc32;
173 long hammer2_check_xxhash64;
174 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, check_icrc32, CTLFLAG_RW,
175 	   &hammer2_check_icrc32, 0, "");
176 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, check_xxhash64, CTLFLAG_RW,
177 	   &hammer2_check_xxhash64, 0, "");
178 
179 static int hammer2_vfs_init(struct vfsconf *conf);
180 static int hammer2_vfs_uninit(struct vfsconf *vfsp);
181 static int hammer2_vfs_mount(struct mount *mp, char *path, caddr_t data,
182 				struct ucred *cred);
183 static int hammer2_remount(hammer2_dev_t *, struct mount *, char *,
184 				struct vnode *, struct ucred *);
185 static int hammer2_recovery(hammer2_dev_t *hmp);
186 static int hammer2_vfs_unmount(struct mount *mp, int mntflags);
187 static int hammer2_vfs_root(struct mount *mp, struct vnode **vpp);
188 static int hammer2_vfs_statfs(struct mount *mp, struct statfs *sbp,
189 				struct ucred *cred);
190 static int hammer2_vfs_statvfs(struct mount *mp, struct statvfs *sbp,
191 				struct ucred *cred);
192 static int hammer2_vfs_fhtovp(struct mount *mp, struct vnode *rootvp,
193 				struct fid *fhp, struct vnode **vpp);
194 static int hammer2_vfs_vptofh(struct vnode *vp, struct fid *fhp);
195 static int hammer2_vfs_checkexp(struct mount *mp, struct sockaddr *nam,
196 				int *exflagsp, struct ucred **credanonp);
197 
198 static int hammer2_install_volume_header(hammer2_dev_t *hmp);
199 static int hammer2_sync_scan2(struct mount *mp, struct vnode *vp, void *data);
200 
201 static void hammer2_update_pmps(hammer2_dev_t *hmp);
202 
203 static void hammer2_mount_helper(struct mount *mp, hammer2_pfs_t *pmp);
204 static void hammer2_unmount_helper(struct mount *mp, hammer2_pfs_t *pmp,
205 				hammer2_dev_t *hmp);
206 
207 /*
208  * HAMMER2 vfs operations.
209  */
210 static struct vfsops hammer2_vfsops = {
211 	.vfs_init	= hammer2_vfs_init,
212 	.vfs_uninit	= hammer2_vfs_uninit,
213 	.vfs_sync	= hammer2_vfs_sync,
214 	.vfs_mount	= hammer2_vfs_mount,
215 	.vfs_unmount	= hammer2_vfs_unmount,
216 	.vfs_root 	= hammer2_vfs_root,
217 	.vfs_statfs	= hammer2_vfs_statfs,
218 	.vfs_statvfs	= hammer2_vfs_statvfs,
219 	.vfs_vget	= hammer2_vfs_vget,
220 	.vfs_vptofh	= hammer2_vfs_vptofh,
221 	.vfs_fhtovp	= hammer2_vfs_fhtovp,
222 	.vfs_checkexp	= hammer2_vfs_checkexp
223 };
224 
225 MALLOC_DEFINE(M_HAMMER2, "HAMMER2-mount", "");
226 
227 VFS_SET(hammer2_vfsops, hammer2, VFCF_MPSAFE);
228 MODULE_VERSION(hammer2, 1);
229 
230 static
231 int
232 hammer2_vfs_init(struct vfsconf *conf)
233 {
234 	static struct objcache_malloc_args margs_read;
235 	static struct objcache_malloc_args margs_write;
236 	static struct objcache_malloc_args margs_vop;
237 
238 	int error;
239 
240 	error = 0;
241 
242 	if (HAMMER2_BLOCKREF_BYTES != sizeof(struct hammer2_blockref))
243 		error = EINVAL;
244 	if (HAMMER2_INODE_BYTES != sizeof(struct hammer2_inode_data))
245 		error = EINVAL;
246 	if (HAMMER2_VOLUME_BYTES != sizeof(struct hammer2_volume_data))
247 		error = EINVAL;
248 
249 	if (error)
250 		kprintf("HAMMER2 structure size mismatch; cannot continue.\n");
251 
252 	margs_read.objsize = 65536;
253 	margs_read.mtype = M_HAMMER2_DEBUFFER;
254 
255 	margs_write.objsize = 32768;
256 	margs_write.mtype = M_HAMMER2_CBUFFER;
257 
258 	margs_vop.objsize = sizeof(hammer2_xop_t);
259 	margs_vop.mtype = M_HAMMER2;
260 
261 	/*
262 	 * Note thaht for the XOPS cache we want backing store allocations
263 	 * to use M_ZERO.  This is not allowed in objcache_get() (to avoid
264 	 * confusion), so use the backing store function that does it.  This
265 	 * means that initial XOPS objects are zerod but REUSED objects are
266 	 * not.  So we are responsible for cleaning the object up sufficiently
267 	 * for our needs before objcache_put()ing it back (typically just the
268 	 * FIFO indices).
269 	 */
270 	cache_buffer_read = objcache_create(margs_read.mtype->ks_shortdesc,
271 				0, 1, NULL, NULL, NULL,
272 				objcache_malloc_alloc,
273 				objcache_malloc_free,
274 				&margs_read);
275 	cache_buffer_write = objcache_create(margs_write.mtype->ks_shortdesc,
276 				0, 1, NULL, NULL, NULL,
277 				objcache_malloc_alloc,
278 				objcache_malloc_free,
279 				&margs_write);
280 	cache_xops = objcache_create(margs_vop.mtype->ks_shortdesc,
281 				0, 1, NULL, NULL, NULL,
282 				objcache_malloc_alloc_zero,
283 				objcache_malloc_free,
284 				&margs_vop);
285 
286 
287 	lockinit(&hammer2_mntlk, "mntlk", 0, 0);
288 	TAILQ_INIT(&hammer2_mntlist);
289 	TAILQ_INIT(&hammer2_pfslist);
290 
291 	hammer2_limit_dirty_chains = maxvnodes / 10;
292 	if (hammer2_limit_dirty_chains > HAMMER2_LIMIT_DIRTY_CHAINS)
293 		hammer2_limit_dirty_chains = HAMMER2_LIMIT_DIRTY_CHAINS;
294 
295 	return (error);
296 }
297 
298 static
299 int
300 hammer2_vfs_uninit(struct vfsconf *vfsp __unused)
301 {
302 	objcache_destroy(cache_buffer_read);
303 	objcache_destroy(cache_buffer_write);
304 	objcache_destroy(cache_xops);
305 	return 0;
306 }
307 
308 /*
309  * Core PFS allocator.  Used to allocate or reference the pmp structure
310  * for PFS cluster mounts and the spmp structure for media (hmp) structures.
311  * The pmp can be passed in or loaded by this function using the chain and
312  * inode data.
313  *
314  * pmp->modify_tid tracks new modify_tid transaction ids for front-end
315  * transactions.  Note that synchronization does not use this field.
316  * (typically frontend operations and synchronization cannot run on the
317  * same PFS node at the same time).
318  *
319  * XXX check locking
320  */
321 hammer2_pfs_t *
322 hammer2_pfsalloc(hammer2_chain_t *chain,
323 		 const hammer2_inode_data_t *ripdata,
324 		 hammer2_tid_t modify_tid, hammer2_dev_t *force_local)
325 {
326 	hammer2_pfs_t *pmp;
327 	hammer2_inode_t *iroot;
328 	int count;
329 	int i;
330 	int j;
331 
332 	pmp = NULL;
333 
334 	/*
335 	 * Locate or create the PFS based on the cluster id.  If ripdata
336 	 * is NULL this is a spmp which is unique and is always allocated.
337 	 *
338 	 * If the device is mounted in local mode all PFSs are considered
339 	 * independent and not part of any cluster (for debugging only).
340 	 */
341 	if (ripdata) {
342 		TAILQ_FOREACH(pmp, &hammer2_pfslist, mntentry) {
343 			if (force_local != pmp->force_local)
344 				continue;
345 			if (force_local == NULL &&
346 			    bcmp(&pmp->pfs_clid, &ripdata->meta.pfs_clid,
347 				 sizeof(pmp->pfs_clid)) == 0) {
348 					break;
349 			} else if (force_local && pmp->pfs_names[0] &&
350 			    strcmp(pmp->pfs_names[0], ripdata->filename) == 0) {
351 					break;
352 			}
353 		}
354 	}
355 
356 	if (pmp == NULL) {
357 		pmp = kmalloc(sizeof(*pmp), M_HAMMER2, M_WAITOK | M_ZERO);
358 		pmp->force_local = force_local;
359 		hammer2_trans_manage_init(pmp);
360 		kmalloc_create(&pmp->minode, "HAMMER2-inodes");
361 		kmalloc_create(&pmp->mmsg, "HAMMER2-pfsmsg");
362 		lockinit(&pmp->lock, "pfslk", 0, 0);
363 		lockinit(&pmp->lock_nlink, "h2nlink", 0, 0);
364 		spin_init(&pmp->inum_spin, "hm2pfsalloc_inum");
365 		spin_init(&pmp->xop_spin, "h2xop");
366 		spin_init(&pmp->lru_spin, "h2lru");
367 		RB_INIT(&pmp->inum_tree);
368 		TAILQ_INIT(&pmp->sideq);
369 		TAILQ_INIT(&pmp->lru_list);
370 		spin_init(&pmp->list_spin, "hm2pfsalloc_list");
371 
372 		/*
373 		 * Distribute backend operations to threads
374 		 */
375 		for (i = 0; i < HAMMER2_XOPGROUPS; ++i)
376 			hammer2_xop_group_init(pmp, &pmp->xop_groups[i]);
377 
378 		/*
379 		 * Save the last media transaction id for the flusher.  Set
380 		 * initial
381 		 */
382 		if (ripdata)
383 			pmp->pfs_clid = ripdata->meta.pfs_clid;
384 		TAILQ_INSERT_TAIL(&hammer2_pfslist, pmp, mntentry);
385 
386 		/*
387 		 * The synchronization thread may start too early, make
388 		 * sure it stays frozen until we are ready to let it go.
389 		 * XXX
390 		 */
391 		/*
392 		pmp->primary_thr.flags = HAMMER2_THREAD_FROZEN |
393 					 HAMMER2_THREAD_REMASTER;
394 		*/
395 	}
396 
397 	/*
398 	 * Create the PFS's root inode and any missing XOP helper threads.
399 	 */
400 	if ((iroot = pmp->iroot) == NULL) {
401 		iroot = hammer2_inode_get(pmp, NULL, NULL, -1);
402 		pmp->iroot = iroot;
403 		hammer2_inode_ref(iroot);
404 		hammer2_inode_unlock(iroot);
405 	}
406 
407 	/*
408 	 * Stop here if no chain is passed in.
409 	 */
410 	if (chain == NULL)
411 		goto done;
412 
413 	/*
414 	 * When a chain is passed in we must add it to the PFS's root
415 	 * inode, update pmp->pfs_types[], and update the syncronization
416 	 * threads.
417 	 *
418 	 * When forcing local mode, mark the PFS as a MASTER regardless.
419 	 *
420 	 * At the moment empty spots can develop due to removals or failures.
421 	 * Ultimately we want to re-fill these spots but doing so might
422 	 * confused running code. XXX
423 	 */
424 	hammer2_inode_ref(iroot);
425 	hammer2_mtx_ex(&iroot->lock);
426 	j = iroot->cluster.nchains;
427 
428 	kprintf("add PFS to pmp %p[%d]\n", pmp, j);
429 
430 	if (j == HAMMER2_MAXCLUSTER) {
431 		kprintf("hammer2_mount: cluster full!\n");
432 		/* XXX fatal error? */
433 	} else {
434 		KKASSERT(chain->pmp == NULL);
435 		chain->pmp = pmp;
436 		hammer2_chain_ref(chain);
437 		iroot->cluster.array[j].chain = chain;
438 		if (force_local)
439 			pmp->pfs_types[j] = HAMMER2_PFSTYPE_MASTER;
440 		else
441 			pmp->pfs_types[j] = ripdata->meta.pfs_type;
442 		pmp->pfs_names[j] = kstrdup(ripdata->filename, M_HAMMER2);
443 		pmp->pfs_hmps[j] = chain->hmp;
444 
445 		/*
446 		 * If the PFS is already mounted we must account
447 		 * for the mount_count here.
448 		 */
449 		if (pmp->mp)
450 			++chain->hmp->mount_count;
451 
452 		/*
453 		 * May have to fixup dirty chain tracking.  Previous
454 		 * pmp was NULL so nothing to undo.
455 		 */
456 		if (chain->flags & HAMMER2_CHAIN_MODIFIED)
457 			hammer2_pfs_memory_inc(pmp);
458 		++j;
459 	}
460 	iroot->cluster.nchains = j;
461 
462 	/*
463 	 * Update nmasters from any PFS inode which is part of the cluster.
464 	 * It is possible that this will result in a value which is too
465 	 * high.  MASTER PFSs are authoritative for pfs_nmasters and will
466 	 * override this value later on.
467 	 *
468 	 * (This informs us of masters that might not currently be
469 	 *  discoverable by this mount).
470 	 */
471 	if (ripdata && pmp->pfs_nmasters < ripdata->meta.pfs_nmasters) {
472 		pmp->pfs_nmasters = ripdata->meta.pfs_nmasters;
473 	}
474 
475 	/*
476 	 * Count visible masters.  Masters are usually added with
477 	 * ripdata->meta.pfs_nmasters set to 1.  This detects when there
478 	 * are more (XXX and must update the master inodes).
479 	 */
480 	count = 0;
481 	for (i = 0; i < iroot->cluster.nchains; ++i) {
482 		if (pmp->pfs_types[i] == HAMMER2_PFSTYPE_MASTER)
483 			++count;
484 	}
485 	if (pmp->pfs_nmasters < count)
486 		pmp->pfs_nmasters = count;
487 
488 	/*
489 	 * Create missing synchronization and support threads.
490 	 *
491 	 * Single-node masters (including snapshots) have nothing to
492 	 * synchronize and do not require this thread.
493 	 *
494 	 * Multi-node masters or any number of soft masters, slaves, copy,
495 	 * or other PFS types need the thread.
496 	 *
497 	 * Each thread is responsible for its particular cluster index.
498 	 * We use independent threads so stalls or mismatches related to
499 	 * any given target do not affect other targets.
500 	 */
501 	for (i = 0; i < iroot->cluster.nchains; ++i) {
502 		/*
503 		 * Single-node masters (including snapshots) have nothing
504 		 * to synchronize and will make direct xops support calls,
505 		 * thus they do not require this thread.
506 		 *
507 		 * Note that there can be thousands of snapshots.  We do not
508 		 * want to create thousands of threads.
509 		 */
510 		if (pmp->pfs_nmasters <= 1 &&
511 		    pmp->pfs_types[i] == HAMMER2_PFSTYPE_MASTER) {
512 			continue;
513 		}
514 
515 		/*
516 		 * Sync support thread
517 		 */
518 		if (pmp->sync_thrs[i].td == NULL) {
519 			hammer2_thr_create(&pmp->sync_thrs[i], pmp,
520 					   "h2nod", i, -1,
521 					   hammer2_primary_sync_thread);
522 		}
523 	}
524 
525 	/*
526 	 * Create missing Xop threads
527 	 *
528 	 * NOTE: We create helper threads for all mounted PFSs or any
529 	 *	 PFSs with 2+ nodes (so the sync thread can update them,
530 	 *	 even if not mounted).
531 	 */
532 	if (pmp->mp || iroot->cluster.nchains >= 2)
533 		hammer2_xop_helper_create(pmp);
534 
535 	hammer2_mtx_unlock(&iroot->lock);
536 	hammer2_inode_drop(iroot);
537 done:
538 	return pmp;
539 }
540 
541 /*
542  * Deallocate an element of a probed PFS.  If destroying and this is a
543  * MASTER, adjust nmasters.
544  *
545  * This function does not physically destroy the PFS element in its device
546  * under the super-root  (see hammer2_ioctl_pfs_delete()).
547  */
548 void
549 hammer2_pfsdealloc(hammer2_pfs_t *pmp, int clindex, int destroying)
550 {
551 	hammer2_inode_t *iroot;
552 	hammer2_chain_t *chain;
553 	int j;
554 
555 	/*
556 	 * Cleanup our reference on iroot.  iroot is (should) not be needed
557 	 * by the flush code.
558 	 */
559 	iroot = pmp->iroot;
560 	if (iroot) {
561 		/*
562 		 * Stop synchronizing
563 		 *
564 		 * XXX flush after acquiring the iroot lock.
565 		 * XXX clean out the cluster index from all inode structures.
566 		 */
567 		hammer2_thr_delete(&pmp->sync_thrs[clindex]);
568 
569 		/*
570 		 * Remove the cluster index from the group.  If destroying
571 		 * the PFS and this is a master, adjust pfs_nmasters.
572 		 */
573 		hammer2_mtx_ex(&iroot->lock);
574 		chain = iroot->cluster.array[clindex].chain;
575 		iroot->cluster.array[clindex].chain = NULL;
576 
577 		switch(pmp->pfs_types[clindex]) {
578 		case HAMMER2_PFSTYPE_MASTER:
579 			if (destroying && pmp->pfs_nmasters > 0)
580 				--pmp->pfs_nmasters;
581 			/* XXX adjust ripdata->meta.pfs_nmasters */
582 			break;
583 		default:
584 			break;
585 		}
586 		pmp->pfs_types[clindex] = HAMMER2_PFSTYPE_NONE;
587 
588 		hammer2_mtx_unlock(&iroot->lock);
589 
590 		/*
591 		 * Release the chain.
592 		 */
593 		if (chain) {
594 			atomic_set_int(&chain->flags, HAMMER2_CHAIN_RELEASE);
595 			hammer2_chain_drop(chain);
596 		}
597 
598 		/*
599 		 * Terminate all XOP threads for the cluster index.
600 		 */
601 		for (j = 0; j < HAMMER2_XOPGROUPS; ++j)
602 			hammer2_thr_delete(&pmp->xop_groups[j].thrs[clindex]);
603 	}
604 }
605 
606 /*
607  * Destroy a PFS, typically only occurs after the last mount on a device
608  * has gone away.
609  */
610 static void
611 hammer2_pfsfree(hammer2_pfs_t *pmp)
612 {
613 	hammer2_inode_t *iroot;
614 	hammer2_chain_t *chain;
615 	int i;
616 	int j;
617 
618 	/*
619 	 * Cleanup our reference on iroot.  iroot is (should) not be needed
620 	 * by the flush code.
621 	 */
622 	TAILQ_REMOVE(&hammer2_pfslist, pmp, mntentry);
623 
624 	iroot = pmp->iroot;
625 	if (iroot) {
626 		for (i = 0; i < iroot->cluster.nchains; ++i) {
627 			hammer2_thr_delete(&pmp->sync_thrs[i]);
628 			for (j = 0; j < HAMMER2_XOPGROUPS; ++j)
629 				hammer2_thr_delete(&pmp->xop_groups[j].thrs[i]);
630 		}
631 #if REPORT_REFS_ERRORS
632 		if (pmp->iroot->refs != 1)
633 			kprintf("PMP->IROOT %p REFS WRONG %d\n",
634 				pmp->iroot, pmp->iroot->refs);
635 #else
636 		KKASSERT(pmp->iroot->refs == 1);
637 #endif
638 		/* ref for pmp->iroot */
639 		hammer2_inode_drop(pmp->iroot);
640 		pmp->iroot = NULL;
641 	}
642 
643 	/*
644 	 * Cleanup chains remaining on LRU list.
645 	 */
646 	kprintf("pfsfree: %p lrucount=%d\n", pmp, pmp->lru_count);
647 	while ((chain = TAILQ_FIRST(&pmp->lru_list)) != NULL) {
648 		hammer2_chain_ref(chain);
649 		atomic_set_int(&chain->flags, HAMMER2_CHAIN_RELEASE);
650 		hammer2_chain_drop(chain);
651 	}
652 
653 	/*
654 	 * Free remaining pmp resources
655 	 */
656 	kmalloc_destroy(&pmp->mmsg);
657 	kmalloc_destroy(&pmp->minode);
658 
659 	kfree(pmp, M_HAMMER2);
660 }
661 
662 /*
663  * Remove all references to hmp from the pfs list.  Any PFS which becomes
664  * empty is terminated and freed.
665  *
666  * XXX inefficient.
667  */
668 static void
669 hammer2_pfsfree_scan(hammer2_dev_t *hmp)
670 {
671 	hammer2_pfs_t *pmp;
672 	hammer2_inode_t *iroot;
673 	hammer2_chain_t *rchain;
674 	int didfreeze;
675 	int i;
676 	int j;
677 
678 again:
679 	TAILQ_FOREACH(pmp, &hammer2_pfslist, mntentry) {
680 		if ((iroot = pmp->iroot) == NULL)
681 			continue;
682 		if (hmp->spmp == pmp) {
683 			kprintf("unmount hmp %p remove spmp %p\n",
684 				hmp, pmp);
685 			hmp->spmp = NULL;
686 		}
687 
688 		/*
689 		 * Determine if this PFS is affected.  If it is we must
690 		 * freeze all management threads and lock its iroot.
691 		 *
692 		 * Freezing a management thread forces it idle, operations
693 		 * in-progress will be aborted and it will have to start
694 		 * over again when unfrozen, or exit if told to exit.
695 		 */
696 		for (i = 0; i < HAMMER2_MAXCLUSTER; ++i) {
697 			if (pmp->pfs_hmps[i] == hmp)
698 				break;
699 		}
700 		if (i != HAMMER2_MAXCLUSTER) {
701 			/*
702 			 * Make sure all synchronization threads are locked
703 			 * down.
704 			 */
705 			for (i = 0; i < HAMMER2_MAXCLUSTER; ++i) {
706 				if (pmp->pfs_hmps[i] == NULL)
707 					continue;
708 				hammer2_thr_freeze_async(&pmp->sync_thrs[i]);
709 				for (j = 0; j < HAMMER2_XOPGROUPS; ++j) {
710 					hammer2_thr_freeze_async(
711 						&pmp->xop_groups[j].thrs[i]);
712 				}
713 			}
714 			for (i = 0; i < HAMMER2_MAXCLUSTER; ++i) {
715 				if (pmp->pfs_hmps[i] == NULL)
716 					continue;
717 				hammer2_thr_freeze(&pmp->sync_thrs[i]);
718 				for (j = 0; j < HAMMER2_XOPGROUPS; ++j) {
719 					hammer2_thr_freeze(
720 						&pmp->xop_groups[j].thrs[i]);
721 				}
722 			}
723 
724 			/*
725 			 * Lock the inode and clean out matching chains.
726 			 * Note that we cannot use hammer2_inode_lock_*()
727 			 * here because that would attempt to validate the
728 			 * cluster that we are in the middle of ripping
729 			 * apart.
730 			 *
731 			 * WARNING! We are working directly on the inodes
732 			 *	    embedded cluster.
733 			 */
734 			hammer2_mtx_ex(&iroot->lock);
735 
736 			/*
737 			 * Remove the chain from matching elements of the PFS.
738 			 */
739 			for (i = 0; i < HAMMER2_MAXCLUSTER; ++i) {
740 				if (pmp->pfs_hmps[i] != hmp)
741 					continue;
742 				hammer2_thr_delete(&pmp->sync_thrs[i]);
743 				for (j = 0; j < HAMMER2_XOPGROUPS; ++j) {
744 					hammer2_thr_delete(
745 						&pmp->xop_groups[j].thrs[i]);
746 				}
747 				rchain = iroot->cluster.array[i].chain;
748 				iroot->cluster.array[i].chain = NULL;
749 				pmp->pfs_types[i] = 0;
750 				if (pmp->pfs_names[i]) {
751 					kfree(pmp->pfs_names[i], M_HAMMER2);
752 					pmp->pfs_names[i] = NULL;
753 				}
754 				if (rchain) {
755 					hammer2_chain_drop(rchain);
756 					/* focus hint */
757 					if (iroot->cluster.focus == rchain)
758 						iroot->cluster.focus = NULL;
759 				}
760 				pmp->pfs_hmps[i] = NULL;
761 			}
762 			hammer2_mtx_unlock(&iroot->lock);
763 			didfreeze = 1;	/* remaster, unfreeze down below */
764 		} else {
765 			didfreeze = 0;
766 		}
767 
768 		/*
769 		 * Cleanup trailing chains.  Gaps may remain.
770 		 */
771 		for (i = HAMMER2_MAXCLUSTER - 1; i >= 0; --i) {
772 			if (pmp->pfs_hmps[i])
773 				break;
774 		}
775 		iroot->cluster.nchains = i + 1;
776 
777 		/*
778 		 * If the PMP has no elements remaining we can destroy it.
779 		 * (this will transition management threads from frozen->exit).
780 		 */
781 		if (iroot->cluster.nchains == 0) {
782 			kprintf("unmount hmp %p last ref to PMP=%p\n",
783 				hmp, pmp);
784 			hammer2_pfsfree(pmp);
785 			goto again;
786 		}
787 
788 		/*
789 		 * If elements still remain we need to set the REMASTER
790 		 * flag and unfreeze it.
791 		 */
792 		if (didfreeze) {
793 			for (i = 0; i < HAMMER2_MAXCLUSTER; ++i) {
794 				if (pmp->pfs_hmps[i] == NULL)
795 					continue;
796 				hammer2_thr_remaster(&pmp->sync_thrs[i]);
797 				hammer2_thr_unfreeze(&pmp->sync_thrs[i]);
798 				for (j = 0; j < HAMMER2_XOPGROUPS; ++j) {
799 					hammer2_thr_remaster(
800 						&pmp->xop_groups[j].thrs[i]);
801 					hammer2_thr_unfreeze(
802 						&pmp->xop_groups[j].thrs[i]);
803 				}
804 			}
805 		}
806 	}
807 }
808 
809 /*
810  * Mount or remount HAMMER2 fileystem from physical media
811  *
812  *	mountroot
813  *		mp		mount point structure
814  *		path		NULL
815  *		data		<unused>
816  *		cred		<unused>
817  *
818  *	mount
819  *		mp		mount point structure
820  *		path		path to mount point
821  *		data		pointer to argument structure in user space
822  *			volume	volume path (device@LABEL form)
823  *			hflags	user mount flags
824  *		cred		user credentials
825  *
826  * RETURNS:	0	Success
827  *		!0	error number
828  */
829 static
830 int
831 hammer2_vfs_mount(struct mount *mp, char *path, caddr_t data,
832 		  struct ucred *cred)
833 {
834 	struct hammer2_mount_info info;
835 	hammer2_pfs_t *pmp;
836 	hammer2_pfs_t *spmp;
837 	hammer2_dev_t *hmp;
838 	hammer2_dev_t *force_local;
839 	hammer2_key_t key_next;
840 	hammer2_key_t key_dummy;
841 	hammer2_key_t lhc;
842 	struct vnode *devvp;
843 	struct nlookupdata nd;
844 	hammer2_chain_t *parent;
845 	hammer2_chain_t *chain;
846 	hammer2_cluster_t *cluster;
847 	const hammer2_inode_data_t *ripdata;
848 	hammer2_blockref_t bref;
849 	struct file *fp;
850 	char devstr[MNAMELEN];
851 	size_t size;
852 	size_t done;
853 	char *dev;
854 	char *label;
855 	int ronly = 1;
856 	int error;
857 	int cache_index;
858 	int i;
859 
860 	hmp = NULL;
861 	pmp = NULL;
862 	dev = NULL;
863 	label = NULL;
864 	devvp = NULL;
865 	cache_index = -1;
866 
867 	kprintf("hammer2_mount\n");
868 
869 	if (path == NULL) {
870 		/*
871 		 * Root mount
872 		 */
873 		bzero(&info, sizeof(info));
874 		info.cluster_fd = -1;
875 		ksnprintf(devstr, sizeof(devstr), "%s",
876 			  mp->mnt_stat.f_mntfromname);
877 		kprintf("hammer2_mount: root '%s'\n", devstr);
878 	} else {
879 		/*
880 		 * Non-root mount or updating a mount
881 		 */
882 		error = copyin(data, &info, sizeof(info));
883 		if (error)
884 			return (error);
885 
886 		error = copyinstr(info.volume, devstr, MNAMELEN - 1, &done);
887 		if (error)
888 			return (error);
889 	}
890 
891 	/* Extract device and label */
892 	dev = devstr;
893 	label = strchr(devstr, '@');
894 	if (label == NULL ||
895 	    ((label + 1) - dev) > done) {
896 		return (EINVAL);
897 	}
898 	*label = '\0';
899 	label++;
900 	if (*label == '\0')
901 		return (EINVAL);
902 
903 	kprintf("hammer2_mount: dev=\"%s\" label=\"%s\"\n",
904 		dev, label);
905 
906 	if (mp->mnt_flag & MNT_UPDATE) {
907 		/*
908 		 * Update mount.  Note that pmp->iroot->cluster is
909 		 * an inode-embedded cluster and thus cannot be
910 		 * directly locked.
911 		 *
912 		 * XXX HAMMER2 needs to implement NFS export via
913 		 *     mountctl.
914 		 */
915 		pmp = MPTOPMP(mp);
916 		pmp->hflags = info.hflags;
917 		cluster = &pmp->iroot->cluster;
918 		for (i = 0; i < cluster->nchains; ++i) {
919 			if (cluster->array[i].chain == NULL)
920 				continue;
921 			hmp = cluster->array[i].chain->hmp;
922 			devvp = hmp->devvp;
923 			error = hammer2_remount(hmp, mp, path,
924 						devvp, cred);
925 			if (error)
926 				break;
927 		}
928 
929 		return error;
930 	}
931 
932 	/*
933 	 * HMP device mount
934 	 *
935 	 * If a path is specified and dev is not an empty string, lookup the
936 	 * name and verify that it referes to a block device.
937 	 *
938 	 * If a path is specified and dev is an empty string we fall through
939 	 * and locate the label in the hmp search.
940 	 */
941 	if (path && *dev != 0) {
942 		error = nlookup_init(&nd, dev, UIO_SYSSPACE, NLC_FOLLOW);
943 		if (error == 0)
944 			error = nlookup(&nd);
945 		if (error == 0)
946 			error = cache_vref(&nd.nl_nch, nd.nl_cred, &devvp);
947 		nlookup_done(&nd);
948 	} else if (path == NULL) {
949 		/* root mount */
950 		cdev_t cdev = kgetdiskbyname(dev);
951 		error = bdevvp(cdev, &devvp);
952 		if (error)
953 			kprintf("hammer2: cannot find '%s'\n", dev);
954 	} else {
955 		/*
956 		 * We will locate the hmp using the label in the hmp loop.
957 		 */
958 		error = 0;
959 	}
960 
961 	if (error == 0 && devvp) {
962 		if (vn_isdisk(devvp, &error))
963 			error = vfs_mountedon(devvp);
964 	}
965 
966 	/*
967 	 * Determine if the device has already been mounted.  After this
968 	 * check hmp will be non-NULL if we are doing the second or more
969 	 * hammer2 mounts from the same device.
970 	 */
971 	lockmgr(&hammer2_mntlk, LK_EXCLUSIVE);
972 	if (devvp) {
973 		/*
974 		 * Match the device
975 		 */
976 		TAILQ_FOREACH(hmp, &hammer2_mntlist, mntentry) {
977 			if (hmp->devvp == devvp)
978 				break;
979 		}
980 	} else if (error == 0) {
981 		/*
982 		 * Match the label to a pmp already probed.
983 		 */
984 		TAILQ_FOREACH(pmp, &hammer2_pfslist, mntentry) {
985 			for (i = 0; i < HAMMER2_MAXCLUSTER; ++i) {
986 				if (pmp->pfs_names[i] &&
987 				    strcmp(pmp->pfs_names[i], label) == 0) {
988 					hmp = pmp->pfs_hmps[i];
989 					break;
990 				}
991 			}
992 			if (hmp)
993 				break;
994 		}
995 		if (hmp == NULL)
996 			error = ENOENT;
997 	}
998 
999 	/*
1000 	 * Open the device if this isn't a secondary mount and construct
1001 	 * the H2 device mount (hmp).
1002 	 */
1003 	if (hmp == NULL) {
1004 		hammer2_chain_t *schain;
1005 		hammer2_xid_t xid;
1006 
1007 		if (error == 0 && vcount(devvp) > 0)
1008 			error = EBUSY;
1009 
1010 		/*
1011 		 * Now open the device
1012 		 */
1013 		if (error == 0) {
1014 			ronly = ((mp->mnt_flag & MNT_RDONLY) != 0);
1015 			vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
1016 			error = vinvalbuf(devvp, V_SAVE, 0, 0);
1017 			if (error == 0) {
1018 				error = VOP_OPEN(devvp,
1019 						 ronly ? FREAD : FREAD | FWRITE,
1020 						 FSCRED, NULL);
1021 			}
1022 			vn_unlock(devvp);
1023 		}
1024 		if (error && devvp) {
1025 			vrele(devvp);
1026 			devvp = NULL;
1027 		}
1028 		if (error) {
1029 			lockmgr(&hammer2_mntlk, LK_RELEASE);
1030 			return error;
1031 		}
1032 		hmp = kmalloc(sizeof(*hmp), M_HAMMER2, M_WAITOK | M_ZERO);
1033 		ksnprintf(hmp->devrepname, sizeof(hmp->devrepname), "%s", dev);
1034 		hmp->ronly = ronly;
1035 		hmp->devvp = devvp;
1036 		hmp->hflags = info.hflags & HMNT2_DEVFLAGS;
1037 		kmalloc_create(&hmp->mchain, "HAMMER2-chains");
1038 		TAILQ_INSERT_TAIL(&hammer2_mntlist, hmp, mntentry);
1039 		RB_INIT(&hmp->iotree);
1040 		spin_init(&hmp->io_spin, "hm2mount_io");
1041 		spin_init(&hmp->list_spin, "hm2mount_list");
1042 		TAILQ_INIT(&hmp->flushq);
1043 
1044 		lockinit(&hmp->vollk, "h2vol", 0, 0);
1045 		lockinit(&hmp->bulklk, "h2bulk", 0, 0);
1046 
1047 		/*
1048 		 * vchain setup. vchain.data is embedded.
1049 		 * vchain.refs is initialized and will never drop to 0.
1050 		 *
1051 		 * NOTE! voldata is not yet loaded.
1052 		 */
1053 		hmp->vchain.hmp = hmp;
1054 		hmp->vchain.refs = 1;
1055 		hmp->vchain.data = (void *)&hmp->voldata;
1056 		hmp->vchain.bref.type = HAMMER2_BREF_TYPE_VOLUME;
1057 		hmp->vchain.bref.data_off = 0 | HAMMER2_PBUFRADIX;
1058 		hmp->vchain.bref.mirror_tid = hmp->voldata.mirror_tid;
1059 
1060 		hammer2_chain_core_init(&hmp->vchain);
1061 		/* hmp->vchain.u.xxx is left NULL */
1062 
1063 		/*
1064 		 * fchain setup.  fchain.data is embedded.
1065 		 * fchain.refs is initialized and will never drop to 0.
1066 		 *
1067 		 * The data is not used but needs to be initialized to
1068 		 * pass assertion muster.  We use this chain primarily
1069 		 * as a placeholder for the freemap's top-level RBTREE
1070 		 * so it does not interfere with the volume's topology
1071 		 * RBTREE.
1072 		 */
1073 		hmp->fchain.hmp = hmp;
1074 		hmp->fchain.refs = 1;
1075 		hmp->fchain.data = (void *)&hmp->voldata.freemap_blockset;
1076 		hmp->fchain.bref.type = HAMMER2_BREF_TYPE_FREEMAP;
1077 		hmp->fchain.bref.data_off = 0 | HAMMER2_PBUFRADIX;
1078 		hmp->fchain.bref.mirror_tid = hmp->voldata.freemap_tid;
1079 		hmp->fchain.bref.methods =
1080 			HAMMER2_ENC_CHECK(HAMMER2_CHECK_FREEMAP) |
1081 			HAMMER2_ENC_COMP(HAMMER2_COMP_NONE);
1082 
1083 		hammer2_chain_core_init(&hmp->fchain);
1084 		/* hmp->fchain.u.xxx is left NULL */
1085 
1086 		/*
1087 		 * Install the volume header and initialize fields from
1088 		 * voldata.
1089 		 */
1090 		error = hammer2_install_volume_header(hmp);
1091 		if (error) {
1092 			hammer2_unmount_helper(mp, NULL, hmp);
1093 			lockmgr(&hammer2_mntlk, LK_RELEASE);
1094 			hammer2_vfs_unmount(mp, MNT_FORCE);
1095 			return error;
1096 		}
1097 
1098 		/*
1099 		 * Really important to get these right or flush will get
1100 		 * confused.
1101 		 */
1102 		hmp->spmp = hammer2_pfsalloc(NULL, NULL, 0, NULL);
1103 		kprintf("alloc spmp %p tid %016jx\n",
1104 			hmp->spmp, hmp->voldata.mirror_tid);
1105 		spmp = hmp->spmp;
1106 
1107 		/*
1108 		 * Dummy-up vchain and fchain's modify_tid.  mirror_tid
1109 		 * is inherited from the volume header.
1110 		 */
1111 		xid = 0;
1112 		hmp->vchain.bref.mirror_tid = hmp->voldata.mirror_tid;
1113 		hmp->vchain.bref.modify_tid = hmp->vchain.bref.mirror_tid;
1114 		hmp->vchain.pmp = spmp;
1115 		hmp->fchain.bref.mirror_tid = hmp->voldata.freemap_tid;
1116 		hmp->fchain.bref.modify_tid = hmp->fchain.bref.mirror_tid;
1117 		hmp->fchain.pmp = spmp;
1118 
1119 		/*
1120 		 * First locate the super-root inode, which is key 0
1121 		 * relative to the volume header's blockset.
1122 		 *
1123 		 * Then locate the root inode by scanning the directory keyspace
1124 		 * represented by the label.
1125 		 */
1126 		parent = hammer2_chain_lookup_init(&hmp->vchain, 0);
1127 		schain = hammer2_chain_lookup(&parent, &key_dummy,
1128 				      HAMMER2_SROOT_KEY, HAMMER2_SROOT_KEY,
1129 				      &cache_index, 0);
1130 		hammer2_chain_lookup_done(parent);
1131 		if (schain == NULL) {
1132 			kprintf("hammer2_mount: invalid super-root\n");
1133 			hammer2_unmount_helper(mp, NULL, hmp);
1134 			lockmgr(&hammer2_mntlk, LK_RELEASE);
1135 			hammer2_vfs_unmount(mp, MNT_FORCE);
1136 			return EINVAL;
1137 		}
1138 		if (schain->error) {
1139 			kprintf("hammer2_mount: error %s reading super-root\n",
1140 				hammer2_error_str(schain->error));
1141 			hammer2_chain_unlock(schain);
1142 			hammer2_chain_drop(schain);
1143 			schain = NULL;
1144 			hammer2_unmount_helper(mp, NULL, hmp);
1145 			lockmgr(&hammer2_mntlk, LK_RELEASE);
1146 			hammer2_vfs_unmount(mp, MNT_FORCE);
1147 			return EINVAL;
1148 		}
1149 
1150 		/*
1151 		 * The super-root always uses an inode_tid of 1 when
1152 		 * creating PFSs.
1153 		 */
1154 		spmp->inode_tid = 1;
1155 		spmp->modify_tid = schain->bref.modify_tid + 1;
1156 
1157 		/*
1158 		 * Sanity-check schain's pmp and finish initialization.
1159 		 * Any chain belonging to the super-root topology should
1160 		 * have a NULL pmp (not even set to spmp).
1161 		 */
1162 		ripdata = &hammer2_chain_rdata(schain)->ipdata;
1163 		KKASSERT(schain->pmp == NULL);
1164 		spmp->pfs_clid = ripdata->meta.pfs_clid;
1165 
1166 		/*
1167 		 * Replace the dummy spmp->iroot with a real one.  It's
1168 		 * easier to just do a wholesale replacement than to try
1169 		 * to update the chain and fixup the iroot fields.
1170 		 *
1171 		 * The returned inode is locked with the supplied cluster.
1172 		 */
1173 		cluster = hammer2_cluster_from_chain(schain);
1174 		hammer2_inode_drop(spmp->iroot);
1175 		spmp->iroot = NULL;
1176 		spmp->iroot = hammer2_inode_get(spmp, NULL, cluster, -1);
1177 		spmp->spmp_hmp = hmp;
1178 		spmp->pfs_types[0] = ripdata->meta.pfs_type;
1179 		spmp->pfs_hmps[0] = hmp;
1180 		hammer2_inode_ref(spmp->iroot);
1181 		hammer2_inode_unlock(spmp->iroot);
1182 		hammer2_cluster_unlock(cluster);
1183 		hammer2_cluster_drop(cluster);
1184 		schain = NULL;
1185 		/* leave spmp->iroot with one ref */
1186 
1187 		if ((mp->mnt_flag & MNT_RDONLY) == 0) {
1188 			error = hammer2_recovery(hmp);
1189 			/* XXX do something with error */
1190 		}
1191 		hammer2_update_pmps(hmp);
1192 		hammer2_iocom_init(hmp);
1193 
1194 		/*
1195 		 * Ref the cluster management messaging descriptor.  The mount
1196 		 * program deals with the other end of the communications pipe.
1197 		 *
1198 		 * Root mounts typically do not supply one.
1199 		 */
1200 		if (info.cluster_fd >= 0) {
1201 			fp = holdfp(curproc->p_fd, info.cluster_fd, -1);
1202 			if (fp) {
1203 				hammer2_cluster_reconnect(hmp, fp);
1204 			} else {
1205 				kprintf("hammer2_mount: bad cluster_fd!\n");
1206 			}
1207 		}
1208 	} else {
1209 		spmp = hmp->spmp;
1210 		if (info.hflags & HMNT2_DEVFLAGS) {
1211 			kprintf("hammer2: Warning: mount flags pertaining "
1212 				"to the whole device may only be specified "
1213 				"on the first mount of the device: %08x\n",
1214 				info.hflags & HMNT2_DEVFLAGS);
1215 		}
1216 	}
1217 
1218 	/*
1219 	 * Force local mount (disassociate all PFSs from their clusters).
1220 	 * Used primarily for debugging.
1221 	 */
1222 	force_local = (hmp->hflags & HMNT2_LOCAL) ? hmp : NULL;
1223 
1224 	/*
1225 	 * Lookup the mount point under the media-localized super-root.
1226 	 * Scanning hammer2_pfslist doesn't help us because it represents
1227 	 * PFS cluster ids which can aggregate several named PFSs together.
1228 	 *
1229 	 * cluster->pmp will incorrectly point to spmp and must be fixed
1230 	 * up later on.
1231 	 */
1232 	hammer2_inode_lock(spmp->iroot, 0);
1233 	parent = hammer2_inode_chain(spmp->iroot, 0, HAMMER2_RESOLVE_ALWAYS);
1234 	lhc = hammer2_dirhash(label, strlen(label));
1235 	chain = hammer2_chain_lookup(&parent, &key_next,
1236 				     lhc, lhc + HAMMER2_DIRHASH_LOMASK,
1237 				     &cache_index, 0);
1238 	while (chain) {
1239 		if (chain->bref.type == HAMMER2_BREF_TYPE_INODE &&
1240 		    strcmp(label, chain->data->ipdata.filename) == 0) {
1241 			break;
1242 		}
1243 		chain = hammer2_chain_next(&parent, chain, &key_next,
1244 					    key_next,
1245 					    lhc + HAMMER2_DIRHASH_LOMASK,
1246 					    &cache_index, 0);
1247 	}
1248 	if (parent) {
1249 		hammer2_chain_unlock(parent);
1250 		hammer2_chain_drop(parent);
1251 	}
1252 	hammer2_inode_unlock(spmp->iroot);
1253 
1254 	/*
1255 	 * PFS could not be found?
1256 	 */
1257 	if (chain == NULL) {
1258 		kprintf("hammer2_mount: PFS label not found\n");
1259 		hammer2_unmount_helper(mp, NULL, hmp);
1260 		lockmgr(&hammer2_mntlk, LK_RELEASE);
1261 		hammer2_vfs_unmount(mp, MNT_FORCE);
1262 
1263 		return EINVAL;
1264 	}
1265 
1266 	/*
1267 	 * Acquire the pmp structure (it should have already been allocated
1268 	 * via hammer2_update_pmps() so do not pass cluster in to add to
1269 	 * available chains).
1270 	 *
1271 	 * Check if the cluster has already been mounted.  A cluster can
1272 	 * only be mounted once, use null mounts to mount additional copies.
1273 	 */
1274 	ripdata = &chain->data->ipdata;
1275 	bref = chain->bref;
1276 	pmp = hammer2_pfsalloc(NULL, ripdata,
1277 			       bref.modify_tid, force_local);
1278 	hammer2_chain_unlock(chain);
1279 	hammer2_chain_drop(chain);
1280 
1281 	/*
1282 	 * Finish the mount
1283 	 */
1284         kprintf("hammer2_mount hmp=%p pmp=%p\n", hmp, pmp);
1285 
1286 	if (pmp->mp) {
1287 		kprintf("hammer2_mount: PFS already mounted!\n");
1288 		hammer2_unmount_helper(mp, NULL, hmp);
1289 		lockmgr(&hammer2_mntlk, LK_RELEASE);
1290 		hammer2_vfs_unmount(mp, MNT_FORCE);
1291 
1292 		return EBUSY;
1293 	}
1294 
1295 	pmp->hflags = info.hflags;
1296         mp->mnt_flag = MNT_LOCAL;
1297         mp->mnt_kern_flag |= MNTK_ALL_MPSAFE;   /* all entry pts are SMP */
1298         mp->mnt_kern_flag |= MNTK_THR_SYNC;     /* new vsyncscan semantics */
1299 
1300         /*
1301          * required mount structure initializations
1302          */
1303         mp->mnt_stat.f_iosize = HAMMER2_PBUFSIZE;
1304         mp->mnt_stat.f_bsize = HAMMER2_PBUFSIZE;
1305 
1306         mp->mnt_vstat.f_frsize = HAMMER2_PBUFSIZE;
1307         mp->mnt_vstat.f_bsize = HAMMER2_PBUFSIZE;
1308 
1309         /*
1310          * Optional fields
1311          */
1312         mp->mnt_iosize_max = MAXPHYS;
1313 
1314 	/*
1315 	 * Connect up mount pointers.
1316 	 */
1317 	hammer2_mount_helper(mp, pmp);
1318 
1319         lockmgr(&hammer2_mntlk, LK_RELEASE);
1320 
1321 	/*
1322 	 * Finish setup
1323 	 */
1324 	vfs_getnewfsid(mp);
1325 	vfs_add_vnodeops(mp, &hammer2_vnode_vops, &mp->mnt_vn_norm_ops);
1326 	vfs_add_vnodeops(mp, &hammer2_spec_vops, &mp->mnt_vn_spec_ops);
1327 	vfs_add_vnodeops(mp, &hammer2_fifo_vops, &mp->mnt_vn_fifo_ops);
1328 
1329 	if (path) {
1330 		copyinstr(info.volume, mp->mnt_stat.f_mntfromname,
1331 			  MNAMELEN - 1, &size);
1332 		bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
1333 	} /* else root mount, already in there */
1334 
1335 	bzero(mp->mnt_stat.f_mntonname, sizeof(mp->mnt_stat.f_mntonname));
1336 	if (path) {
1337 		copyinstr(path, mp->mnt_stat.f_mntonname,
1338 			  sizeof(mp->mnt_stat.f_mntonname) - 1,
1339 			  &size);
1340 	} else {
1341 		/* root mount */
1342 		mp->mnt_stat.f_mntonname[0] = '/';
1343 	}
1344 
1345 	/*
1346 	 * Initial statfs to prime mnt_stat.
1347 	 */
1348 	hammer2_vfs_statfs(mp, &mp->mnt_stat, cred);
1349 
1350 	return 0;
1351 }
1352 
1353 /*
1354  * Scan PFSs under the super-root and create hammer2_pfs structures.
1355  */
1356 static
1357 void
1358 hammer2_update_pmps(hammer2_dev_t *hmp)
1359 {
1360 	const hammer2_inode_data_t *ripdata;
1361 	hammer2_chain_t *parent;
1362 	hammer2_chain_t *chain;
1363 	hammer2_blockref_t bref;
1364 	hammer2_dev_t *force_local;
1365 	hammer2_pfs_t *spmp;
1366 	hammer2_pfs_t *pmp;
1367 	hammer2_key_t key_next;
1368 	int cache_index = -1;
1369 
1370 	/*
1371 	 * Force local mount (disassociate all PFSs from their clusters).
1372 	 * Used primarily for debugging.
1373 	 */
1374 	force_local = (hmp->hflags & HMNT2_LOCAL) ? hmp : NULL;
1375 
1376 	/*
1377 	 * Lookup mount point under the media-localized super-root.
1378 	 *
1379 	 * cluster->pmp will incorrectly point to spmp and must be fixed
1380 	 * up later on.
1381 	 */
1382 	spmp = hmp->spmp;
1383 	hammer2_inode_lock(spmp->iroot, 0);
1384 	parent = hammer2_inode_chain(spmp->iroot, 0, HAMMER2_RESOLVE_ALWAYS);
1385 	chain = hammer2_chain_lookup(&parent, &key_next,
1386 					 HAMMER2_KEY_MIN, HAMMER2_KEY_MAX,
1387 					 &cache_index, 0);
1388 	while (chain) {
1389 		if (chain->bref.type != HAMMER2_BREF_TYPE_INODE)
1390 			continue;
1391 		ripdata = &chain->data->ipdata;
1392 		bref = chain->bref;
1393 		kprintf("ADD LOCAL PFS: %s\n", ripdata->filename);
1394 
1395 		pmp = hammer2_pfsalloc(chain, ripdata,
1396 				       bref.modify_tid, force_local);
1397 		chain = hammer2_chain_next(&parent, chain, &key_next,
1398 					   key_next, HAMMER2_KEY_MAX,
1399 					   &cache_index, 0);
1400 	}
1401 	if (parent) {
1402 		hammer2_chain_unlock(parent);
1403 		hammer2_chain_drop(parent);
1404 	}
1405 	hammer2_inode_unlock(spmp->iroot);
1406 }
1407 
1408 static
1409 int
1410 hammer2_remount(hammer2_dev_t *hmp, struct mount *mp, char *path __unused,
1411 		struct vnode *devvp, struct ucred *cred)
1412 {
1413 	int error;
1414 
1415 	if (hmp->ronly && (mp->mnt_kern_flag & MNTK_WANTRDWR)) {
1416 		error = hammer2_recovery(hmp);
1417 	} else {
1418 		error = 0;
1419 	}
1420 	return error;
1421 }
1422 
1423 static
1424 int
1425 hammer2_vfs_unmount(struct mount *mp, int mntflags)
1426 {
1427 	hammer2_pfs_t *pmp;
1428 	int flags;
1429 	int error = 0;
1430 
1431 	pmp = MPTOPMP(mp);
1432 
1433 	if (pmp == NULL)
1434 		return(0);
1435 
1436 	lockmgr(&hammer2_mntlk, LK_EXCLUSIVE);
1437 
1438 	/*
1439 	 * If mount initialization proceeded far enough we must flush
1440 	 * its vnodes and sync the underlying mount points.  Three syncs
1441 	 * are required to fully flush the filesystem (freemap updates lag
1442 	 * by one flush, and one extra for safety).
1443 	 */
1444 	if (mntflags & MNT_FORCE)
1445 		flags = FORCECLOSE;
1446 	else
1447 		flags = 0;
1448 	if (pmp->iroot) {
1449 		error = vflush(mp, 0, flags);
1450 		if (error)
1451 			goto failed;
1452 		hammer2_vfs_sync(mp, MNT_WAIT);
1453 		hammer2_vfs_sync(mp, MNT_WAIT);
1454 		hammer2_vfs_sync(mp, MNT_WAIT);
1455 	}
1456 
1457 	/*
1458 	 * Cleanup the frontend support XOPS threads
1459 	 */
1460 	hammer2_xop_helper_cleanup(pmp);
1461 
1462 	if (pmp->mp)
1463 		hammer2_unmount_helper(mp, pmp, NULL);
1464 
1465 	error = 0;
1466 failed:
1467 	lockmgr(&hammer2_mntlk, LK_RELEASE);
1468 
1469 	return (error);
1470 }
1471 
1472 /*
1473  * Mount helper, hook the system mount into our PFS.
1474  * The mount lock is held.
1475  *
1476  * We must bump the mount_count on related devices for any
1477  * mounted PFSs.
1478  */
1479 static
1480 void
1481 hammer2_mount_helper(struct mount *mp, hammer2_pfs_t *pmp)
1482 {
1483 	hammer2_cluster_t *cluster;
1484 	hammer2_chain_t *rchain;
1485 	int i;
1486 
1487         mp->mnt_data = (qaddr_t)pmp;
1488 	pmp->mp = mp;
1489 
1490 	/*
1491 	 * After pmp->mp is set we have to adjust hmp->mount_count.
1492 	 */
1493 	cluster = &pmp->iroot->cluster;
1494 	for (i = 0; i < cluster->nchains; ++i) {
1495 		rchain = cluster->array[i].chain;
1496 		if (rchain == NULL)
1497 			continue;
1498 		++rchain->hmp->mount_count;
1499 		kprintf("hammer2_mount hmp=%p ++mount_count=%d\n",
1500 			rchain->hmp, rchain->hmp->mount_count);
1501 	}
1502 
1503 	/*
1504 	 * Create missing Xop threads
1505 	 */
1506 	hammer2_xop_helper_create(pmp);
1507 }
1508 
1509 /*
1510  * Mount helper, unhook the system mount from our PFS.
1511  * The mount lock is held.
1512  *
1513  * If hmp is supplied a mount responsible for being the first to open
1514  * the block device failed and the block device and all PFSs using the
1515  * block device must be cleaned up.
1516  *
1517  * If pmp is supplied multiple devices might be backing the PFS and each
1518  * must be disconnected.  This might not be the last PFS using some of the
1519  * underlying devices.  Also, we have to adjust our hmp->mount_count
1520  * accounting for the devices backing the pmp which is now undergoing an
1521  * unmount.
1522  */
1523 static
1524 void
1525 hammer2_unmount_helper(struct mount *mp, hammer2_pfs_t *pmp, hammer2_dev_t *hmp)
1526 {
1527 	hammer2_cluster_t *cluster;
1528 	hammer2_chain_t *rchain;
1529 	struct vnode *devvp;
1530 	int dumpcnt;
1531 	int ronly = 0;
1532 	int i;
1533 
1534 	/*
1535 	 * If no device supplied this is a high-level unmount and we have to
1536 	 * to disconnect the mount, adjust mount_count, and locate devices
1537 	 * that might now have no mounts.
1538 	 */
1539 	if (pmp) {
1540 		KKASSERT(hmp == NULL);
1541 		KKASSERT((void *)(intptr_t)mp->mnt_data == pmp);
1542 		pmp->mp = NULL;
1543 		mp->mnt_data = NULL;
1544 
1545 		/*
1546 		 * After pmp->mp is cleared we have to account for
1547 		 * mount_count.
1548 		 */
1549 		cluster = &pmp->iroot->cluster;
1550 		for (i = 0; i < cluster->nchains; ++i) {
1551 			rchain = cluster->array[i].chain;
1552 			if (rchain == NULL)
1553 				continue;
1554 			--rchain->hmp->mount_count;
1555 			kprintf("hammer2_unmount hmp=%p --mount_count=%d\n",
1556 				rchain->hmp, rchain->hmp->mount_count);
1557 			/* scrapping hmp now may invalidate the pmp */
1558 		}
1559 again:
1560 		TAILQ_FOREACH(hmp, &hammer2_mntlist, mntentry) {
1561 			if (hmp->mount_count == 0) {
1562 				hammer2_unmount_helper(NULL, NULL, hmp);
1563 				goto again;
1564 			}
1565 		}
1566 		return;
1567 	}
1568 
1569 	/*
1570 	 * Try to terminate the block device.  We can't terminate it if
1571 	 * there are still PFSs referencing it.
1572 	 */
1573 	kprintf("hammer2_unmount hmp=%p mount_count=%d\n",
1574 		hmp, hmp->mount_count);
1575 	if (hmp->mount_count)
1576 		return;
1577 
1578 	hammer2_pfsfree_scan(hmp);
1579 	hammer2_dev_exlock(hmp);	/* XXX order */
1580 
1581 	/*
1582 	 * Cycle the volume data lock as a safety (probably not needed any
1583 	 * more).  To ensure everything is out we need to flush at least
1584 	 * three times.  (1) The running of the sideq can dirty the
1585 	 * filesystem, (2) A normal flush can dirty the freemap, and
1586 	 * (3) ensure that the freemap is fully synchronized.
1587 	 *
1588 	 * The next mount's recovery scan can clean everything up but we want
1589 	 * to leave the filesystem in a 100% clean state on a normal unmount.
1590 	 */
1591 #if 0
1592 	hammer2_voldata_lock(hmp);
1593 	hammer2_voldata_unlock(hmp);
1594 #endif
1595 	hammer2_iocom_uninit(hmp);
1596 
1597 	if ((hmp->vchain.flags | hmp->fchain.flags) &
1598 	    HAMMER2_CHAIN_FLUSH_MASK) {
1599 		kprintf("hammer2_unmount: chains left over "
1600 			"after final sync\n");
1601 		kprintf("    vchain %08x\n", hmp->vchain.flags);
1602 		kprintf("    fchain %08x\n", hmp->fchain.flags);
1603 
1604 		if (hammer2_debug & 0x0010)
1605 			Debugger("entered debugger");
1606 	}
1607 
1608 	KKASSERT(hmp->spmp == NULL);
1609 
1610 	/*
1611 	 * Finish up with the device vnode
1612 	 */
1613 	if ((devvp = hmp->devvp) != NULL) {
1614 		vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
1615 		vinvalbuf(devvp, (ronly ? 0 : V_SAVE), 0, 0);
1616 		hmp->devvp = NULL;
1617 		VOP_CLOSE(devvp, (ronly ? FREAD : FREAD|FWRITE), NULL);
1618 		vn_unlock(devvp);
1619 		vrele(devvp);
1620 		devvp = NULL;
1621 	}
1622 
1623 	/*
1624 	 * Clear vchain/fchain flags that might prevent final cleanup
1625 	 * of these chains.
1626 	 */
1627 	if (hmp->vchain.flags & HAMMER2_CHAIN_MODIFIED) {
1628 		atomic_add_long(&hammer2_count_modified_chains, -1);
1629 		atomic_clear_int(&hmp->vchain.flags, HAMMER2_CHAIN_MODIFIED);
1630 		hammer2_pfs_memory_wakeup(hmp->vchain.pmp);
1631 	}
1632 	if (hmp->vchain.flags & HAMMER2_CHAIN_UPDATE) {
1633 		atomic_clear_int(&hmp->vchain.flags, HAMMER2_CHAIN_UPDATE);
1634 	}
1635 
1636 	if (hmp->fchain.flags & HAMMER2_CHAIN_MODIFIED) {
1637 		atomic_add_long(&hammer2_count_modified_chains, -1);
1638 		atomic_clear_int(&hmp->fchain.flags, HAMMER2_CHAIN_MODIFIED);
1639 		hammer2_pfs_memory_wakeup(hmp->fchain.pmp);
1640 	}
1641 	if (hmp->fchain.flags & HAMMER2_CHAIN_UPDATE) {
1642 		atomic_clear_int(&hmp->fchain.flags, HAMMER2_CHAIN_UPDATE);
1643 	}
1644 
1645 	/*
1646 	 * Final drop of embedded freemap root chain to
1647 	 * clean up fchain.core (fchain structure is not
1648 	 * flagged ALLOCATED so it is cleaned out and then
1649 	 * left to rot).
1650 	 */
1651 	hammer2_chain_drop(&hmp->fchain);
1652 
1653 	/*
1654 	 * Final drop of embedded volume root chain to clean
1655 	 * up vchain.core (vchain structure is not flagged
1656 	 * ALLOCATED so it is cleaned out and then left to
1657 	 * rot).
1658 	 */
1659 	dumpcnt = 50;
1660 	hammer2_dump_chain(&hmp->vchain, 0, &dumpcnt, 'v');
1661 	dumpcnt = 50;
1662 	hammer2_dump_chain(&hmp->fchain, 0, &dumpcnt, 'f');
1663 	hammer2_dev_unlock(hmp);
1664 	hammer2_chain_drop(&hmp->vchain);
1665 
1666 	hammer2_io_cleanup(hmp, &hmp->iotree);
1667 	if (hmp->iofree_count) {
1668 		kprintf("io_cleanup: %d I/O's left hanging\n",
1669 			hmp->iofree_count);
1670 	}
1671 
1672 	TAILQ_REMOVE(&hammer2_mntlist, hmp, mntentry);
1673 	kmalloc_destroy(&hmp->mchain);
1674 	kfree(hmp, M_HAMMER2);
1675 }
1676 
1677 int
1678 hammer2_vfs_vget(struct mount *mp, struct vnode *dvp,
1679 		 ino_t ino, struct vnode **vpp)
1680 {
1681 	hammer2_xop_lookup_t *xop;
1682 	hammer2_pfs_t *pmp;
1683 	hammer2_inode_t *ip;
1684 	hammer2_tid_t inum;
1685 	int error;
1686 
1687 	inum = (hammer2_tid_t)ino & HAMMER2_DIRHASH_USERMSK;
1688 
1689 	error = 0;
1690 	pmp = MPTOPMP(mp);
1691 
1692 	/*
1693 	 * Easy if we already have it cached
1694 	 */
1695 	ip = hammer2_inode_lookup(pmp, inum);
1696 	if (ip) {
1697 		hammer2_inode_lock(ip, HAMMER2_RESOLVE_SHARED);
1698 		*vpp = hammer2_igetv(ip, &error);
1699 		hammer2_inode_unlock(ip);
1700 		hammer2_inode_drop(ip);		/* from lookup */
1701 
1702 		return error;
1703 	}
1704 
1705 	/*
1706 	 * Otherwise we have to find the inode
1707 	 */
1708 	xop = hammer2_xop_alloc(pmp->iroot, 0);
1709 	xop->lhc = inum;
1710 	hammer2_xop_start(&xop->head, hammer2_xop_lookup);
1711 	error = hammer2_xop_collect(&xop->head, 0);
1712 
1713 	if (error == 0) {
1714 		if (hammer2_cluster_rdata(&xop->head.cluster) == NULL) {
1715 			kprintf("vget: no collect error but also no rdata\n");
1716 			kprintf("xop %p\n", xop);
1717 			while ((hammer2_debug & 0x80000) == 0) {
1718 				tsleep(xop, PCATCH, "wait", hz * 10);
1719 			}
1720 			ip = NULL;
1721 		} else {
1722 			ip = hammer2_inode_get(pmp, NULL, &xop->head.cluster, -1);
1723 		}
1724 	}
1725 	hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
1726 
1727 	if (ip) {
1728 		*vpp = hammer2_igetv(ip, &error);
1729 		hammer2_inode_unlock(ip);
1730 	} else {
1731 		*vpp = NULL;
1732 		error = ENOENT;
1733 	}
1734 	return (error);
1735 }
1736 
1737 static
1738 int
1739 hammer2_vfs_root(struct mount *mp, struct vnode **vpp)
1740 {
1741 	hammer2_pfs_t *pmp;
1742 	struct vnode *vp;
1743 	int error;
1744 
1745 	pmp = MPTOPMP(mp);
1746 	if (pmp->iroot == NULL) {
1747 		*vpp = NULL;
1748 		return EINVAL;
1749 	}
1750 
1751 	error = 0;
1752 	hammer2_inode_lock(pmp->iroot, HAMMER2_RESOLVE_SHARED);
1753 
1754 	while (pmp->inode_tid == 0) {
1755 		hammer2_xop_ipcluster_t *xop;
1756 		hammer2_inode_meta_t *meta;
1757 
1758 		xop = hammer2_xop_alloc(pmp->iroot, HAMMER2_XOP_MODIFYING);
1759 		hammer2_xop_start(&xop->head, hammer2_xop_ipcluster);
1760 		error = hammer2_xop_collect(&xop->head, 0);
1761 
1762 		if (error == 0) {
1763 			meta = &xop->head.cluster.focus->data->ipdata.meta;
1764 			pmp->iroot->meta = *meta;
1765 			pmp->inode_tid = meta->pfs_inum + 1;
1766 			if (pmp->inode_tid < HAMMER2_INODE_START)
1767 				pmp->inode_tid = HAMMER2_INODE_START;
1768 			pmp->modify_tid =
1769 				xop->head.cluster.focus->bref.modify_tid + 1;
1770 			kprintf("PFS: Starting inode %jd\n",
1771 				(intmax_t)pmp->inode_tid);
1772 			kprintf("PMP focus good set nextino=%ld mod=%016jx\n",
1773 				pmp->inode_tid, pmp->modify_tid);
1774 			wakeup(&pmp->iroot);
1775 
1776 			hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
1777 
1778 			/*
1779 			 * Prime the mount info.
1780 			 */
1781 			hammer2_vfs_statfs(mp, &mp->mnt_stat, NULL);
1782 			break;
1783 		}
1784 
1785 		/*
1786 		 * Loop, try again
1787 		 */
1788 		hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
1789 		hammer2_inode_unlock(pmp->iroot);
1790 		error = tsleep(&pmp->iroot, PCATCH, "h2root", hz);
1791 		hammer2_inode_lock(pmp->iroot, HAMMER2_RESOLVE_SHARED);
1792 		if (error == EINTR)
1793 			break;
1794 	}
1795 
1796 	if (error) {
1797 		hammer2_inode_unlock(pmp->iroot);
1798 		*vpp = NULL;
1799 	} else {
1800 		vp = hammer2_igetv(pmp->iroot, &error);
1801 		hammer2_inode_unlock(pmp->iroot);
1802 		*vpp = vp;
1803 	}
1804 
1805 	return (error);
1806 }
1807 
1808 /*
1809  * Filesystem status
1810  *
1811  * XXX incorporate ipdata->meta.inode_quota and data_quota
1812  */
1813 static
1814 int
1815 hammer2_vfs_statfs(struct mount *mp, struct statfs *sbp, struct ucred *cred)
1816 {
1817 	hammer2_pfs_t *pmp;
1818 	hammer2_dev_t *hmp;
1819 	hammer2_blockref_t bref;
1820 	int i;
1821 
1822 	/*
1823 	 * NOTE: iroot might not have validated the cluster yet.
1824 	 */
1825 	pmp = MPTOPMP(mp);
1826 
1827 	mp->mnt_stat.f_files = 0;
1828 	mp->mnt_stat.f_ffree = 0;
1829 	mp->mnt_stat.f_blocks = 0;
1830 	mp->mnt_stat.f_bfree = 0;
1831 	mp->mnt_stat.f_bavail = 0;
1832 
1833 	for (i = 0; i < pmp->iroot->cluster.nchains; ++i) {
1834 		hmp = pmp->pfs_hmps[i];
1835 		if (hmp == NULL)
1836 			continue;
1837 		if (pmp->iroot->cluster.array[i].chain)
1838 			bref = pmp->iroot->cluster.array[i].chain->bref;
1839 		else
1840 			bzero(&bref, sizeof(bref));
1841 
1842 		mp->mnt_stat.f_files = bref.inode_count;
1843 		mp->mnt_stat.f_ffree = 0;
1844 #if 0
1845 		mp->mnt_stat.f_blocks = (bref.data_count +
1846 					 hmp->voldata.allocator_free) /
1847 					mp->mnt_vstat.f_bsize;
1848 		mp->mnt_stat.f_bfree =  hmp->voldata.allocator_free /
1849 					mp->mnt_vstat.f_bsize;
1850 #endif
1851 		mp->mnt_stat.f_blocks = hmp->voldata.allocator_size /
1852 					mp->mnt_vstat.f_bsize;
1853 		mp->mnt_stat.f_bfree = hmp->voldata.allocator_free /
1854 					mp->mnt_vstat.f_bsize;
1855 		mp->mnt_stat.f_bavail = mp->mnt_stat.f_bfree;
1856 
1857 		*sbp = mp->mnt_stat;
1858 	}
1859 	return (0);
1860 }
1861 
1862 static
1863 int
1864 hammer2_vfs_statvfs(struct mount *mp, struct statvfs *sbp, struct ucred *cred)
1865 {
1866 	hammer2_pfs_t *pmp;
1867 	hammer2_dev_t *hmp;
1868 	hammer2_blockref_t bref;
1869 	int i;
1870 
1871 	/*
1872 	 * NOTE: iroot might not have validated the cluster yet.
1873 	 */
1874 	pmp = MPTOPMP(mp);
1875 
1876 	mp->mnt_vstat.f_bsize = 0;
1877 	mp->mnt_vstat.f_files = 0;
1878 	mp->mnt_vstat.f_ffree = 0;
1879 	mp->mnt_vstat.f_blocks = 0;
1880 	mp->mnt_vstat.f_bfree = 0;
1881 	mp->mnt_vstat.f_bavail = 0;
1882 
1883 	for (i = 0; i < pmp->iroot->cluster.nchains; ++i) {
1884 		hmp = pmp->pfs_hmps[i];
1885 		if (hmp == NULL)
1886 			continue;
1887 		if (pmp->iroot->cluster.array[i].chain)
1888 			bref = pmp->iroot->cluster.array[i].chain->bref;
1889 		else
1890 			bzero(&bref, sizeof(bref));
1891 
1892 		mp->mnt_vstat.f_bsize = HAMMER2_PBUFSIZE;
1893 		mp->mnt_vstat.f_files = bref.inode_count;
1894 		mp->mnt_vstat.f_ffree = 0;
1895 #if 0
1896 		mp->mnt_vstat.f_blocks = (bref.data_count +
1897 					 hmp->voldata.allocator_free) /
1898 					mp->mnt_vstat.f_bsize;
1899 		mp->mnt_vstat.f_bfree = hmp->voldata.allocator_free /
1900 					mp->mnt_vstat.f_bsize;
1901 #endif
1902 		mp->mnt_vstat.f_blocks = hmp->voldata.allocator_size /
1903 					mp->mnt_vstat.f_bsize;
1904 		mp->mnt_vstat.f_bfree = hmp->voldata.allocator_free /
1905 					mp->mnt_vstat.f_bsize;
1906 		mp->mnt_vstat.f_bavail = mp->mnt_vstat.f_bfree;
1907 
1908 		*sbp = mp->mnt_vstat;
1909 	}
1910 	return (0);
1911 }
1912 
1913 /*
1914  * Mount-time recovery (RW mounts)
1915  *
1916  * Updates to the free block table are allowed to lag flushes by one
1917  * transaction.  In case of a crash, then on a fresh mount we must do an
1918  * incremental scan of the last committed transaction id and make sure that
1919  * all related blocks have been marked allocated.
1920  *
1921  * The super-root topology and each PFS has its own transaction id domain,
1922  * so we must track PFS boundary transitions.
1923  */
1924 struct hammer2_recovery_elm {
1925 	TAILQ_ENTRY(hammer2_recovery_elm) entry;
1926 	hammer2_chain_t *chain;
1927 	hammer2_tid_t sync_tid;
1928 };
1929 
1930 TAILQ_HEAD(hammer2_recovery_list, hammer2_recovery_elm);
1931 
1932 struct hammer2_recovery_info {
1933 	struct hammer2_recovery_list list;
1934 	hammer2_tid_t	mtid;
1935 	int	depth;
1936 };
1937 
1938 static int hammer2_recovery_scan(hammer2_dev_t *hmp,
1939 			hammer2_chain_t *parent,
1940 			struct hammer2_recovery_info *info,
1941 			hammer2_tid_t sync_tid);
1942 
1943 #define HAMMER2_RECOVERY_MAXDEPTH	10
1944 
1945 static
1946 int
1947 hammer2_recovery(hammer2_dev_t *hmp)
1948 {
1949 	struct hammer2_recovery_info info;
1950 	struct hammer2_recovery_elm *elm;
1951 	hammer2_chain_t *parent;
1952 	hammer2_tid_t sync_tid;
1953 	hammer2_tid_t mirror_tid;
1954 	int error;
1955 	int cumulative_error = 0;
1956 
1957 	hammer2_trans_init(hmp->spmp, 0);
1958 
1959 	sync_tid = hmp->voldata.freemap_tid;
1960 	mirror_tid = hmp->voldata.mirror_tid;
1961 
1962 	kprintf("hammer2 mount \"%s\": ", hmp->devrepname);
1963 	if (sync_tid >= mirror_tid) {
1964 		kprintf(" no recovery needed\n");
1965 	} else {
1966 		kprintf(" freemap recovery %016jx-%016jx\n",
1967 			sync_tid + 1, mirror_tid);
1968 	}
1969 
1970 	TAILQ_INIT(&info.list);
1971 	info.depth = 0;
1972 	parent = hammer2_chain_lookup_init(&hmp->vchain, 0);
1973 	cumulative_error = hammer2_recovery_scan(hmp, parent, &info, sync_tid);
1974 	hammer2_chain_lookup_done(parent);
1975 
1976 	while ((elm = TAILQ_FIRST(&info.list)) != NULL) {
1977 		TAILQ_REMOVE(&info.list, elm, entry);
1978 		parent = elm->chain;
1979 		sync_tid = elm->sync_tid;
1980 		kfree(elm, M_HAMMER2);
1981 
1982 		hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS);
1983 		error = hammer2_recovery_scan(hmp, parent, &info,
1984 					      hmp->voldata.freemap_tid);
1985 		hammer2_chain_unlock(parent);
1986 		hammer2_chain_drop(parent);	/* drop elm->chain ref */
1987 		if (error)
1988 			cumulative_error = error;
1989 	}
1990 	hammer2_trans_done(hmp->spmp);
1991 
1992 	return cumulative_error;
1993 }
1994 
1995 static
1996 int
1997 hammer2_recovery_scan(hammer2_dev_t *hmp, hammer2_chain_t *parent,
1998 		      struct hammer2_recovery_info *info,
1999 		      hammer2_tid_t sync_tid)
2000 {
2001 	const hammer2_inode_data_t *ripdata;
2002 	hammer2_chain_t *chain;
2003 	hammer2_blockref_t bref;
2004 	int cache_index;
2005 	int cumulative_error = 0;
2006 	int error;
2007 	int first;
2008 
2009 	/*
2010 	 * Adjust freemap to ensure that the block(s) are marked allocated.
2011 	 */
2012 	if (parent->bref.type != HAMMER2_BREF_TYPE_VOLUME) {
2013 		hammer2_freemap_adjust(hmp, &parent->bref,
2014 				       HAMMER2_FREEMAP_DORECOVER);
2015 	}
2016 
2017 	/*
2018 	 * Check type for recursive scan
2019 	 */
2020 	switch(parent->bref.type) {
2021 	case HAMMER2_BREF_TYPE_VOLUME:
2022 		/* data already instantiated */
2023 		break;
2024 	case HAMMER2_BREF_TYPE_INODE:
2025 		/*
2026 		 * Must instantiate data for DIRECTDATA test and also
2027 		 * for recursion.
2028 		 */
2029 		hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS);
2030 		ripdata = &hammer2_chain_rdata(parent)->ipdata;
2031 		if (ripdata->meta.op_flags & HAMMER2_OPFLAG_DIRECTDATA) {
2032 			/* not applicable to recovery scan */
2033 			hammer2_chain_unlock(parent);
2034 			return 0;
2035 		}
2036 		hammer2_chain_unlock(parent);
2037 		break;
2038 	case HAMMER2_BREF_TYPE_INDIRECT:
2039 		/*
2040 		 * Must instantiate data for recursion
2041 		 */
2042 		hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS);
2043 		hammer2_chain_unlock(parent);
2044 		break;
2045 	case HAMMER2_BREF_TYPE_DATA:
2046 	case HAMMER2_BREF_TYPE_FREEMAP:
2047 	case HAMMER2_BREF_TYPE_FREEMAP_NODE:
2048 	case HAMMER2_BREF_TYPE_FREEMAP_LEAF:
2049 		/* not applicable to recovery scan */
2050 		return 0;
2051 		break;
2052 	default:
2053 		return EDOM;
2054 	}
2055 
2056 	/*
2057 	 * Defer operation if depth limit reached or if we are crossing a
2058 	 * PFS boundary.
2059 	 */
2060 	if (info->depth >= HAMMER2_RECOVERY_MAXDEPTH) {
2061 		struct hammer2_recovery_elm *elm;
2062 
2063 		elm = kmalloc(sizeof(*elm), M_HAMMER2, M_ZERO | M_WAITOK);
2064 		elm->chain = parent;
2065 		elm->sync_tid = sync_tid;
2066 		hammer2_chain_ref(parent);
2067 		TAILQ_INSERT_TAIL(&info->list, elm, entry);
2068 		/* unlocked by caller */
2069 
2070 		return(0);
2071 	}
2072 
2073 
2074 	/*
2075 	 * Recursive scan of the last flushed transaction only.  We are
2076 	 * doing this without pmp assignments so don't leave the chains
2077 	 * hanging around after we are done with them.
2078 	 */
2079 	cache_index = 0;
2080 	chain = NULL;
2081 	first = 1;
2082 
2083 	while (hammer2_chain_scan(parent, &chain, &bref,
2084 				  &first, &cache_index,
2085 				  HAMMER2_LOOKUP_NODATA) != NULL) {
2086 		/*
2087 		 * If this is a leaf
2088 		 */
2089 		if (chain == NULL) {
2090 			if (bref.mirror_tid > sync_tid) {
2091 				hammer2_freemap_adjust(hmp, &bref,
2092 						     HAMMER2_FREEMAP_DORECOVER);
2093 			}
2094 			continue;
2095 		}
2096 
2097 		/*
2098 		 * This may or may not be a recursive node.
2099 		 */
2100 		atomic_set_int(&chain->flags, HAMMER2_CHAIN_RELEASE);
2101 		if (bref.mirror_tid > sync_tid) {
2102 			++info->depth;
2103 			error = hammer2_recovery_scan(hmp, chain,
2104 						      info, sync_tid);
2105 			--info->depth;
2106 			if (error)
2107 				cumulative_error = error;
2108 		}
2109 
2110 		/*
2111 		 * Flush the recovery at the PFS boundary to stage it for
2112 		 * the final flush of the super-root topology.
2113 		 */
2114 		if ((bref.flags & HAMMER2_BREF_FLAG_PFSROOT) &&
2115 		    (chain->flags & HAMMER2_CHAIN_ONFLUSH)) {
2116 			hammer2_flush(chain, HAMMER2_FLUSH_TOP);
2117 		}
2118 	}
2119 
2120 	return cumulative_error;
2121 }
2122 
2123 /*
2124  * Sync a mount point; this is called on a per-mount basis from the
2125  * filesystem syncer process periodically and whenever a user issues
2126  * a sync.
2127  */
2128 int
2129 hammer2_vfs_sync(struct mount *mp, int waitfor)
2130 {
2131 	hammer2_xop_flush_t *xop;
2132 	struct hammer2_sync_info info;
2133 	hammer2_inode_t *iroot;
2134 	hammer2_pfs_t *pmp;
2135 	int flags;
2136 	int error;
2137 
2138 	pmp = MPTOPMP(mp);
2139 	iroot = pmp->iroot;
2140 	KKASSERT(iroot);
2141 	KKASSERT(iroot->pmp == pmp);
2142 
2143 	/*
2144 	 * We can't acquire locks on existing vnodes while in a transaction
2145 	 * without risking a deadlock.  This assumes that vfsync() can be
2146 	 * called without the vnode locked (which it can in DragonFly).
2147 	 * Otherwise we'd have to implement a multi-pass or flag the lock
2148 	 * failures and retry.
2149 	 *
2150 	 * The reclamation code interlocks with the sync list's token
2151 	 * (by removing the vnode from the scan list) before unlocking
2152 	 * the inode, giving us time to ref the inode.
2153 	 */
2154 	/*flags = VMSC_GETVP;*/
2155 	flags = 0;
2156 	if (waitfor & MNT_LAZY)
2157 		flags |= VMSC_ONEPASS;
2158 
2159 	/*
2160 	 * Preflush the vnodes using a normal transaction before interlocking
2161 	 * with a flush transaction.  We do this to try to run as much of
2162 	 * the compression as possible outside the flush transaction.
2163 	 *
2164 	 * For efficiency do an async pass before making sure with a
2165 	 * synchronous pass on all related buffer cache buffers.
2166 	 */
2167 	hammer2_trans_init(pmp, 0);
2168 	info.error = 0;
2169 	info.waitfor = MNT_NOWAIT;
2170 	vsyncscan(mp, flags | VMSC_NOWAIT, hammer2_sync_scan2, &info);
2171 	info.waitfor = MNT_WAIT;
2172 	vsyncscan(mp, flags, hammer2_sync_scan2, &info);
2173 	hammer2_trans_done(pmp);
2174 
2175 	/*
2176 	 * Start our flush transaction.  This does not return until all
2177 	 * concurrent transactions have completed and will prevent any
2178 	 * new transactions from running concurrently, except for the
2179 	 * buffer cache transactions.
2180 	 *
2181 	 * NOTE!  It is still possible for the paging code to push pages
2182 	 *	  out via a UIO_NOCOPY hammer2_vop_write() during the main
2183 	 *	  flush.
2184 	 */
2185 	hammer2_trans_init(pmp, HAMMER2_TRANS_ISFLUSH);
2186 	hammer2_inode_run_sideq(pmp);
2187 
2188 	info.error = 0;
2189 	info.waitfor = MNT_NOWAIT;
2190 	vsyncscan(mp, flags | VMSC_NOWAIT, hammer2_sync_scan2, &info);
2191 	info.waitfor = MNT_WAIT;
2192 	vsyncscan(mp, flags, hammer2_sync_scan2, &info);
2193 	hammer2_bioq_sync(pmp);
2194 
2195 	/*
2196 	 * Use the XOP interface to concurrently flush all nodes to
2197 	 * synchronize the PFSROOT subtopology to the media.  A standard
2198 	 * end-of-scan ENOENT error indicates cluster sufficiency.
2199 	 *
2200 	 * Note that this flush will not be visible on crash recovery until
2201 	 * we flush the super-root topology in the next loop.
2202 	 *
2203 	 * XXX For now wait for all flushes to complete.
2204 	 */
2205 	if (iroot) {
2206 		xop = hammer2_xop_alloc(iroot, HAMMER2_XOP_MODIFYING);
2207 		hammer2_xop_start(&xop->head, hammer2_inode_xop_flush);
2208 		error = hammer2_xop_collect(&xop->head,
2209 					    HAMMER2_XOP_COLLECT_WAITALL);
2210 		hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
2211 		if (error == ENOENT)
2212 			error = 0;
2213 	} else {
2214 		error = 0;
2215 	}
2216 	hammer2_trans_done(pmp);
2217 
2218 	return (error);
2219 }
2220 
2221 /*
2222  * Sync passes.
2223  *
2224  * Note that we ignore the tranasction mtid we got above.  Instead,
2225  * each vfsync below will ultimately get its own via TRANS_BUFCACHE
2226  * transactions.
2227  */
2228 static int
2229 hammer2_sync_scan2(struct mount *mp, struct vnode *vp, void *data)
2230 {
2231 	struct hammer2_sync_info *info = data;
2232 	hammer2_inode_t *ip;
2233 	int error;
2234 
2235 	/*
2236 	 * Degenerate cases.  Note that ip == NULL typically means the
2237 	 * syncer vnode itself and we don't want to vclrisdirty() in that
2238 	 * situation.
2239 	 */
2240 	ip = VTOI(vp);
2241 	if (ip == NULL) {
2242 		return(0);
2243 	}
2244 	if (vp->v_type == VNON || vp->v_type == VBAD) {
2245 		vclrisdirty(vp);
2246 		return(0);
2247 	}
2248 
2249 	/*
2250 	 * VOP_FSYNC will start a new transaction so replicate some code
2251 	 * here to do it inline (see hammer2_vop_fsync()).
2252 	 *
2253 	 * WARNING: The vfsync interacts with the buffer cache and might
2254 	 *          block, we can't hold the inode lock at that time.
2255 	 *	    However, we MUST ref ip before blocking to ensure that
2256 	 *	    it isn't ripped out from under us (since we do not
2257 	 *	    hold a lock on the vnode).
2258 	 */
2259 	hammer2_inode_ref(ip);
2260 	if ((ip->flags & HAMMER2_INODE_MODIFIED) ||
2261 	    !RB_EMPTY(&vp->v_rbdirty_tree)) {
2262 		vfsync(vp, info->waitfor, 1, NULL, NULL);
2263 		if (ip->flags & (HAMMER2_INODE_RESIZED |
2264 				 HAMMER2_INODE_MODIFIED)) {
2265 			hammer2_inode_lock(ip, 0);
2266 			hammer2_inode_chain_sync(ip);
2267 			hammer2_inode_unlock(ip);
2268 		}
2269 	}
2270 	if ((ip->flags & HAMMER2_INODE_MODIFIED) == 0 &&
2271 	    RB_EMPTY(&vp->v_rbdirty_tree)) {
2272 		vclrisdirty(vp);
2273 	}
2274 
2275 	hammer2_inode_drop(ip);
2276 #if 1
2277 	error = 0;
2278 	if (error)
2279 		info->error = error;
2280 #endif
2281 	return(0);
2282 }
2283 
2284 static
2285 int
2286 hammer2_vfs_vptofh(struct vnode *vp, struct fid *fhp)
2287 {
2288 	hammer2_inode_t *ip;
2289 
2290 	KKASSERT(MAXFIDSZ >= 16);
2291 	ip = VTOI(vp);
2292 	fhp->fid_len = offsetof(struct fid, fid_data[16]);
2293 	fhp->fid_ext = 0;
2294 	((hammer2_tid_t *)fhp->fid_data)[0] = ip->meta.inum;
2295 	((hammer2_tid_t *)fhp->fid_data)[1] = 0;
2296 
2297 	return 0;
2298 }
2299 
2300 static
2301 int
2302 hammer2_vfs_fhtovp(struct mount *mp, struct vnode *rootvp,
2303 	       struct fid *fhp, struct vnode **vpp)
2304 {
2305 	hammer2_pfs_t *pmp;
2306 	hammer2_tid_t inum;
2307 	int error;
2308 
2309 	pmp = MPTOPMP(mp);
2310 	inum = ((hammer2_tid_t *)fhp->fid_data)[0] & HAMMER2_DIRHASH_USERMSK;
2311 	if (vpp) {
2312 		if (inum == 1)
2313 			error = hammer2_vfs_root(mp, vpp);
2314 		else
2315 			error = hammer2_vfs_vget(mp, NULL, inum, vpp);
2316 	} else {
2317 		error = 0;
2318 	}
2319 	if (error)
2320 		kprintf("fhtovp: %016jx -> %p, %d\n", inum, *vpp, error);
2321 	return error;
2322 }
2323 
2324 static
2325 int
2326 hammer2_vfs_checkexp(struct mount *mp, struct sockaddr *nam,
2327 		 int *exflagsp, struct ucred **credanonp)
2328 {
2329 	hammer2_pfs_t *pmp;
2330 	struct netcred *np;
2331 	int error;
2332 
2333 	pmp = MPTOPMP(mp);
2334 	np = vfs_export_lookup(mp, &pmp->export, nam);
2335 	if (np) {
2336 		*exflagsp = np->netc_exflags;
2337 		*credanonp = &np->netc_anon;
2338 		error = 0;
2339 	} else {
2340 		error = EACCES;
2341 	}
2342 	return error;
2343 }
2344 
2345 /*
2346  * Support code for hammer2_vfs_mount().  Read, verify, and install the volume
2347  * header into the HMP
2348  *
2349  * XXX read four volhdrs and use the one with the highest TID whos CRC
2350  *     matches.
2351  *
2352  * XXX check iCRCs.
2353  *
2354  * XXX For filesystems w/ less than 4 volhdrs, make sure to not write to
2355  *     nonexistant locations.
2356  *
2357  * XXX Record selected volhdr and ring updates to each of 4 volhdrs
2358  */
2359 static
2360 int
2361 hammer2_install_volume_header(hammer2_dev_t *hmp)
2362 {
2363 	hammer2_volume_data_t *vd;
2364 	struct buf *bp;
2365 	hammer2_crc32_t crc0, crc, bcrc0, bcrc;
2366 	int error_reported;
2367 	int error;
2368 	int valid;
2369 	int i;
2370 
2371 	error_reported = 0;
2372 	error = 0;
2373 	valid = 0;
2374 	bp = NULL;
2375 
2376 	/*
2377 	 * There are up to 4 copies of the volume header (syncs iterate
2378 	 * between them so there is no single master).  We don't trust the
2379 	 * volu_size field so we don't know precisely how large the filesystem
2380 	 * is, so depend on the OS to return an error if we go beyond the
2381 	 * block device's EOF.
2382 	 */
2383 	for (i = 0; i < HAMMER2_NUM_VOLHDRS; i++) {
2384 		error = bread(hmp->devvp, i * HAMMER2_ZONE_BYTES64,
2385 			      HAMMER2_VOLUME_BYTES, &bp);
2386 		if (error) {
2387 			brelse(bp);
2388 			bp = NULL;
2389 			continue;
2390 		}
2391 
2392 		vd = (struct hammer2_volume_data *) bp->b_data;
2393 		if ((vd->magic != HAMMER2_VOLUME_ID_HBO) &&
2394 		    (vd->magic != HAMMER2_VOLUME_ID_ABO)) {
2395 			brelse(bp);
2396 			bp = NULL;
2397 			continue;
2398 		}
2399 
2400 		if (vd->magic == HAMMER2_VOLUME_ID_ABO) {
2401 			/* XXX: Reversed-endianness filesystem */
2402 			kprintf("hammer2: reverse-endian filesystem detected");
2403 			brelse(bp);
2404 			bp = NULL;
2405 			continue;
2406 		}
2407 
2408 		crc = vd->icrc_sects[HAMMER2_VOL_ICRC_SECT0];
2409 		crc0 = hammer2_icrc32(bp->b_data + HAMMER2_VOLUME_ICRC0_OFF,
2410 				      HAMMER2_VOLUME_ICRC0_SIZE);
2411 		bcrc = vd->icrc_sects[HAMMER2_VOL_ICRC_SECT1];
2412 		bcrc0 = hammer2_icrc32(bp->b_data + HAMMER2_VOLUME_ICRC1_OFF,
2413 				       HAMMER2_VOLUME_ICRC1_SIZE);
2414 		if ((crc0 != crc) || (bcrc0 != bcrc)) {
2415 			kprintf("hammer2 volume header crc "
2416 				"mismatch copy #%d %08x/%08x\n",
2417 				i, crc0, crc);
2418 			error_reported = 1;
2419 			brelse(bp);
2420 			bp = NULL;
2421 			continue;
2422 		}
2423 		if (valid == 0 || hmp->voldata.mirror_tid < vd->mirror_tid) {
2424 			valid = 1;
2425 			hmp->voldata = *vd;
2426 			hmp->volhdrno = i;
2427 		}
2428 		brelse(bp);
2429 		bp = NULL;
2430 	}
2431 	if (valid) {
2432 		hmp->volsync = hmp->voldata;
2433 		error = 0;
2434 		if (error_reported || bootverbose || 1) { /* 1/DEBUG */
2435 			kprintf("hammer2: using volume header #%d\n",
2436 				hmp->volhdrno);
2437 		}
2438 	} else {
2439 		error = EINVAL;
2440 		kprintf("hammer2: no valid volume headers found!\n");
2441 	}
2442 	return (error);
2443 }
2444 
2445 /*
2446  * This handles hysteresis on regular file flushes.  Because the BIOs are
2447  * routed to a thread it is possible for an excessive number to build up
2448  * and cause long front-end stalls long before the runningbuffspace limit
2449  * is hit, so we implement hammer2_flush_pipe to control the
2450  * hysteresis.
2451  *
2452  * This is a particular problem when compression is used.
2453  */
2454 void
2455 hammer2_lwinprog_ref(hammer2_pfs_t *pmp)
2456 {
2457 	atomic_add_int(&pmp->count_lwinprog, 1);
2458 }
2459 
2460 void
2461 hammer2_lwinprog_drop(hammer2_pfs_t *pmp)
2462 {
2463 	int lwinprog;
2464 
2465 	lwinprog = atomic_fetchadd_int(&pmp->count_lwinprog, -1);
2466 	if ((lwinprog & HAMMER2_LWINPROG_WAITING) &&
2467 	    (lwinprog & HAMMER2_LWINPROG_MASK) <= hammer2_flush_pipe * 2 / 3) {
2468 		atomic_clear_int(&pmp->count_lwinprog,
2469 				 HAMMER2_LWINPROG_WAITING);
2470 		wakeup(&pmp->count_lwinprog);
2471 	}
2472 	if ((lwinprog & HAMMER2_LWINPROG_WAITING0) &&
2473 	    (lwinprog & HAMMER2_LWINPROG_MASK) <= 0) {
2474 		atomic_clear_int(&pmp->count_lwinprog,
2475 				 HAMMER2_LWINPROG_WAITING0);
2476 		wakeup(&pmp->count_lwinprog);
2477 	}
2478 }
2479 
2480 void
2481 hammer2_lwinprog_wait(hammer2_pfs_t *pmp, int flush_pipe)
2482 {
2483 	int lwinprog;
2484 	int lwflag = (flush_pipe) ? HAMMER2_LWINPROG_WAITING :
2485 				    HAMMER2_LWINPROG_WAITING0;
2486 
2487 	for (;;) {
2488 		lwinprog = pmp->count_lwinprog;
2489 		cpu_ccfence();
2490 		if ((lwinprog & HAMMER2_LWINPROG_MASK) <= flush_pipe)
2491 			break;
2492 		tsleep_interlock(&pmp->count_lwinprog, 0);
2493 		atomic_set_int(&pmp->count_lwinprog, lwflag);
2494 		lwinprog = pmp->count_lwinprog;
2495 		if ((lwinprog & HAMMER2_LWINPROG_MASK) <= flush_pipe)
2496 			break;
2497 		tsleep(&pmp->count_lwinprog, PINTERLOCKED, "h2wpipe", hz);
2498 	}
2499 }
2500 
2501 /*
2502  * Manage excessive memory resource use for chain and related
2503  * structures.
2504  */
2505 void
2506 hammer2_pfs_memory_wait(hammer2_pfs_t *pmp)
2507 {
2508 	uint32_t waiting;
2509 	uint32_t count;
2510 	uint32_t limit;
2511 #if 0
2512 	static int zzticks;
2513 #endif
2514 
2515 	/*
2516 	 * Atomic check condition and wait.  Also do an early speedup of
2517 	 * the syncer to try to avoid hitting the wait.
2518 	 */
2519 	for (;;) {
2520 		waiting = pmp->inmem_dirty_chains;
2521 		cpu_ccfence();
2522 		count = waiting & HAMMER2_DIRTYCHAIN_MASK;
2523 
2524 		limit = pmp->mp->mnt_nvnodelistsize / 10;
2525 		if (limit < hammer2_limit_dirty_chains)
2526 			limit = hammer2_limit_dirty_chains;
2527 		if (limit < 1000)
2528 			limit = 1000;
2529 
2530 #if 0
2531 		if ((int)(ticks - zzticks) > hz) {
2532 			zzticks = ticks;
2533 			kprintf("count %ld %ld\n", count, limit);
2534 		}
2535 #endif
2536 
2537 		/*
2538 		 * Block if there are too many dirty chains present, wait
2539 		 * for the flush to clean some out.
2540 		 */
2541 		if (count > limit) {
2542 			tsleep_interlock(&pmp->inmem_dirty_chains, 0);
2543 			if (atomic_cmpset_int(&pmp->inmem_dirty_chains,
2544 					       waiting,
2545 				       waiting | HAMMER2_DIRTYCHAIN_WAITING)) {
2546 				speedup_syncer(pmp->mp);
2547 				tsleep(&pmp->inmem_dirty_chains, PINTERLOCKED,
2548 				       "chnmem", hz);
2549 			}
2550 			continue;	/* loop on success or fail */
2551 		}
2552 
2553 		/*
2554 		 * Try to start an early flush before we are forced to block.
2555 		 */
2556 		if (count > limit * 7 / 10)
2557 			speedup_syncer(pmp->mp);
2558 		break;
2559 	}
2560 }
2561 
2562 void
2563 hammer2_pfs_memory_inc(hammer2_pfs_t *pmp)
2564 {
2565 	if (pmp) {
2566 		atomic_add_int(&pmp->inmem_dirty_chains, 1);
2567 	}
2568 }
2569 
2570 void
2571 hammer2_pfs_memory_wakeup(hammer2_pfs_t *pmp)
2572 {
2573 	uint32_t waiting;
2574 
2575 	if (pmp == NULL)
2576 		return;
2577 
2578 	for (;;) {
2579 		waiting = pmp->inmem_dirty_chains;
2580 		cpu_ccfence();
2581 		if (atomic_cmpset_int(&pmp->inmem_dirty_chains,
2582 				       waiting,
2583 				       (waiting - 1) &
2584 					~HAMMER2_DIRTYCHAIN_WAITING)) {
2585 			break;
2586 		}
2587 	}
2588 
2589 	if (waiting & HAMMER2_DIRTYCHAIN_WAITING)
2590 		wakeup(&pmp->inmem_dirty_chains);
2591 }
2592 
2593 /*
2594  * Debugging
2595  */
2596 void
2597 hammer2_dump_chain(hammer2_chain_t *chain, int tab, int *countp, char pfx)
2598 {
2599 	hammer2_chain_t *scan;
2600 	hammer2_chain_t *parent;
2601 
2602 	--*countp;
2603 	if (*countp == 0) {
2604 		kprintf("%*.*s...\n", tab, tab, "");
2605 		return;
2606 	}
2607 	if (*countp < 0)
2608 		return;
2609 	kprintf("%*.*s%c-chain %p.%d %016jx/%d mir=%016jx\n",
2610 		tab, tab, "", pfx,
2611 		chain, chain->bref.type,
2612 		chain->bref.key, chain->bref.keybits,
2613 		chain->bref.mirror_tid);
2614 
2615 	kprintf("%*.*s      [%08x] (%s) refs=%d",
2616 		tab, tab, "",
2617 		chain->flags,
2618 		((chain->bref.type == HAMMER2_BREF_TYPE_INODE &&
2619 		chain->data) ?  (char *)chain->data->ipdata.filename : "?"),
2620 		chain->refs);
2621 
2622 	parent = chain->parent;
2623 	if (parent)
2624 		kprintf("\n%*.*s      p=%p [pflags %08x prefs %d",
2625 			tab, tab, "",
2626 			parent, parent->flags, parent->refs);
2627 	if (RB_EMPTY(&chain->core.rbtree)) {
2628 		kprintf("\n");
2629 	} else {
2630 		kprintf(" {\n");
2631 		RB_FOREACH(scan, hammer2_chain_tree, &chain->core.rbtree)
2632 			hammer2_dump_chain(scan, tab + 4, countp, 'a');
2633 		if (chain->bref.type == HAMMER2_BREF_TYPE_INODE && chain->data)
2634 			kprintf("%*.*s}(%s)\n", tab, tab, "",
2635 				chain->data->ipdata.filename);
2636 		else
2637 			kprintf("%*.*s}\n", tab, tab, "");
2638 	}
2639 }
2640