xref: /dragonfly/sys/vfs/hammer2/hammer2_vfsops.c (revision f984587a)
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/vfsops.h>
43 #include <sys/sysctl.h>
44 #include <sys/socket.h>
45 #include <sys/objcache.h>
46 #include <sys/proc.h>
47 #include <sys/lock.h>
48 #include <sys/file.h>
49 
50 #include "hammer2.h"
51 
52 TAILQ_HEAD(hammer2_mntlist, hammer2_dev);
53 static struct hammer2_mntlist hammer2_mntlist;
54 
55 struct hammer2_pfslist hammer2_pfslist;
56 struct hammer2_pfslist hammer2_spmplist;
57 struct lock hammer2_mntlk;
58 
59 int hammer2_supported_version = HAMMER2_VOL_VERSION_DEFAULT;
60 int hammer2_debug;
61 int hammer2_aux_flags;
62 int hammer2_xop_nthreads;
63 int hammer2_xop_sgroups;
64 int hammer2_xop_xgroups;
65 int hammer2_xop_xbase;
66 int hammer2_xop_mod;
67 long hammer2_debug_inode;
68 int hammer2_cluster_meta_read = 1;	/* physical read-ahead */
69 int hammer2_cluster_data_read = 4;	/* physical read-ahead */
70 int hammer2_cluster_write = 0;		/* physical write clustering */
71 int hammer2_dedup_enable = 1;
72 int hammer2_always_compress = 0;	/* always try to compress */
73 int hammer2_flush_pipe = 100;
74 int hammer2_dio_count;
75 int hammer2_dio_limit = 256;
76 int hammer2_bulkfree_tps = 5000;
77 int hammer2_spread_workers;
78 int hammer2_limit_saved_depth;
79 long hammer2_chain_allocs;
80 long hammer2_limit_saved_chains;
81 long hammer2_limit_dirty_chains;
82 long hammer2_limit_dirty_inodes;
83 long hammer2_count_modified_chains;
84 long hammer2_iod_file_read;
85 long hammer2_iod_meta_read;
86 long hammer2_iod_indr_read;
87 long hammer2_iod_fmap_read;
88 long hammer2_iod_volu_read;
89 long hammer2_iod_file_write;
90 long hammer2_iod_file_wembed;
91 long hammer2_iod_file_wzero;
92 long hammer2_iod_file_wdedup;
93 long hammer2_iod_meta_write;
94 long hammer2_iod_indr_write;
95 long hammer2_iod_fmap_write;
96 long hammer2_iod_volu_write;
97 static long hammer2_iod_inode_creates;
98 static long hammer2_iod_inode_deletes;
99 
100 long hammer2_process_icrc32;
101 long hammer2_process_xxhash64;
102 
103 MALLOC_DECLARE(M_HAMMER2_CBUFFER);
104 MALLOC_DEFINE(M_HAMMER2_CBUFFER, "HAMMER2-compbuffer",
105 		"Buffer used for compression.");
106 
107 MALLOC_DECLARE(M_HAMMER2_DEBUFFER);
108 MALLOC_DEFINE(M_HAMMER2_DEBUFFER, "HAMMER2-decompbuffer",
109 		"Buffer used for decompression.");
110 
111 SYSCTL_NODE(_vfs, OID_AUTO, hammer2, CTLFLAG_RW, 0, "HAMMER2 filesystem");
112 
113 SYSCTL_INT(_vfs_hammer2, OID_AUTO, supported_version, CTLFLAG_RD,
114 	   &hammer2_supported_version, 0, "");
115 SYSCTL_INT(_vfs_hammer2, OID_AUTO, aux_flags, CTLFLAG_RW,
116 	   &hammer2_aux_flags, 0, "");
117 SYSCTL_INT(_vfs_hammer2, OID_AUTO, debug, CTLFLAG_RW,
118 	   &hammer2_debug, 0, "");
119 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, debug_inode, CTLFLAG_RW,
120 	   &hammer2_debug_inode, 0, "");
121 SYSCTL_INT(_vfs_hammer2, OID_AUTO, spread_workers, CTLFLAG_RW,
122 	   &hammer2_spread_workers, 0, "");
123 SYSCTL_INT(_vfs_hammer2, OID_AUTO, cluster_meta_read, CTLFLAG_RW,
124 	   &hammer2_cluster_meta_read, 0, "");
125 SYSCTL_INT(_vfs_hammer2, OID_AUTO, cluster_data_read, CTLFLAG_RW,
126 	   &hammer2_cluster_data_read, 0, "");
127 SYSCTL_INT(_vfs_hammer2, OID_AUTO, cluster_write, CTLFLAG_RW,
128 	   &hammer2_cluster_write, 0, "");
129 SYSCTL_INT(_vfs_hammer2, OID_AUTO, dedup_enable, CTLFLAG_RW,
130 	   &hammer2_dedup_enable, 0, "");
131 SYSCTL_INT(_vfs_hammer2, OID_AUTO, always_compress, CTLFLAG_RW,
132 	   &hammer2_always_compress, 0, "");
133 SYSCTL_INT(_vfs_hammer2, OID_AUTO, flush_pipe, CTLFLAG_RW,
134 	   &hammer2_flush_pipe, 0, "");
135 SYSCTL_INT(_vfs_hammer2, OID_AUTO, bulkfree_tps, CTLFLAG_RW,
136 	   &hammer2_bulkfree_tps, 0, "");
137 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, chain_allocs, CTLFLAG_RD,
138 	   &hammer2_chain_allocs, 0, "");
139 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, limit_saved_chains, CTLFLAG_RW,
140 	   &hammer2_limit_saved_chains, 0, "");
141 SYSCTL_INT(_vfs_hammer2, OID_AUTO, limit_saved_depth, CTLFLAG_RW,
142 	   &hammer2_limit_saved_depth, 0, "");
143 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, limit_dirty_chains, CTLFLAG_RW,
144 	   &hammer2_limit_dirty_chains, 0, "");
145 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, limit_dirty_inodes, CTLFLAG_RW,
146 	   &hammer2_limit_dirty_inodes, 0, "");
147 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, count_modified_chains, CTLFLAG_RD,
148 	   &hammer2_count_modified_chains, 0, "");
149 SYSCTL_INT(_vfs_hammer2, OID_AUTO, dio_count, CTLFLAG_RD,
150 	   &hammer2_dio_count, 0, "");
151 SYSCTL_INT(_vfs_hammer2, OID_AUTO, dio_limit, CTLFLAG_RW,
152 	   &hammer2_dio_limit, 0, "");
153 
154 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_file_read, CTLFLAG_RD,
155 	   &hammer2_iod_file_read, 0, "");
156 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_meta_read, CTLFLAG_RD,
157 	   &hammer2_iod_meta_read, 0, "");
158 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_indr_read, CTLFLAG_RD,
159 	   &hammer2_iod_indr_read, 0, "");
160 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_fmap_read, CTLFLAG_RD,
161 	   &hammer2_iod_fmap_read, 0, "");
162 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_volu_read, CTLFLAG_RD,
163 	   &hammer2_iod_volu_read, 0, "");
164 
165 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_file_write, CTLFLAG_RD,
166 	   &hammer2_iod_file_write, 0, "");
167 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_file_wembed, CTLFLAG_RD,
168 	   &hammer2_iod_file_wembed, 0, "");
169 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_file_wzero, CTLFLAG_RD,
170 	   &hammer2_iod_file_wzero, 0, "");
171 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_file_wdedup, CTLFLAG_RD,
172 	   &hammer2_iod_file_wdedup, 0, "");
173 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_meta_write, CTLFLAG_RD,
174 	   &hammer2_iod_meta_write, 0, "");
175 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_indr_write, CTLFLAG_RD,
176 	   &hammer2_iod_indr_write, 0, "");
177 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_fmap_write, CTLFLAG_RD,
178 	   &hammer2_iod_fmap_write, 0, "");
179 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_volu_write, CTLFLAG_RD,
180 	   &hammer2_iod_volu_write, 0, "");
181 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_inode_creates, CTLFLAG_RD,
182 	   &hammer2_iod_inode_creates, 0, "");
183 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_inode_deletes, CTLFLAG_RD,
184 	   &hammer2_iod_inode_deletes, 0, "");
185 
186 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, process_icrc32, CTLFLAG_RD,
187 	   &hammer2_process_icrc32, 0, "");
188 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, process_xxhash64, CTLFLAG_RD,
189 	   &hammer2_process_xxhash64, 0, "");
190 
191 static int hammer2_vfs_init(struct vfsconf *conf);
192 static int hammer2_vfs_uninit(struct vfsconf *vfsp);
193 static int hammer2_vfs_mount(struct mount *mp, char *path, caddr_t data,
194 				struct ucred *cred);
195 static int hammer2_remount(hammer2_dev_t *, struct mount *, char *,
196 				struct ucred *);
197 static int hammer2_recovery(hammer2_dev_t *hmp);
198 static int hammer2_vfs_unmount(struct mount *mp, int mntflags);
199 static int hammer2_vfs_root(struct mount *mp, struct vnode **vpp);
200 static int hammer2_vfs_statfs(struct mount *mp, struct statfs *sbp,
201 				struct ucred *cred);
202 static int hammer2_vfs_statvfs(struct mount *mp, struct statvfs *sbp,
203 				struct ucred *cred);
204 static int hammer2_vfs_fhtovp(struct mount *mp, struct vnode *rootvp,
205 				struct fid *fhp, struct vnode **vpp);
206 static int hammer2_vfs_vptofh(struct vnode *vp, struct fid *fhp);
207 static int hammer2_vfs_checkexp(struct mount *mp, struct sockaddr *nam,
208 				int *exflagsp, struct ucred **credanonp);
209 static int hammer2_vfs_modifying(struct mount *mp);
210 
211 static void hammer2_update_pmps(hammer2_dev_t *hmp);
212 
213 static void hammer2_mount_helper(struct mount *mp, hammer2_pfs_t *pmp);
214 static void hammer2_unmount_helper(struct mount *mp, hammer2_pfs_t *pmp,
215 				hammer2_dev_t *hmp);
216 static int hammer2_fixup_pfses(hammer2_dev_t *hmp);
217 
218 /*
219  * HAMMER2 vfs operations.
220  */
221 static struct vfsops hammer2_vfsops = {
222 	.vfs_flags	= 0,
223 	.vfs_init	= hammer2_vfs_init,
224 	.vfs_uninit	= hammer2_vfs_uninit,
225 	.vfs_sync	= hammer2_vfs_sync,
226 	.vfs_mount	= hammer2_vfs_mount,
227 	.vfs_unmount	= hammer2_vfs_unmount,
228 	.vfs_root	= hammer2_vfs_root,
229 	.vfs_statfs	= hammer2_vfs_statfs,
230 	.vfs_statvfs	= hammer2_vfs_statvfs,
231 	.vfs_vget	= hammer2_vfs_vget,
232 	.vfs_vptofh	= hammer2_vfs_vptofh,
233 	.vfs_fhtovp	= hammer2_vfs_fhtovp,
234 	.vfs_checkexp	= hammer2_vfs_checkexp,
235 	.vfs_modifying	= hammer2_vfs_modifying
236 };
237 
238 MALLOC_DEFINE(M_HAMMER2, "HAMMER2-mount", "");
239 
240 VFS_SET(hammer2_vfsops, hammer2, VFCF_MPSAFE);
241 MODULE_VERSION(hammer2, 1);
242 
243 static
244 int
245 hammer2_vfs_init(struct vfsconf *conf)
246 {
247 	static struct objcache_malloc_args margs_read;
248 	static struct objcache_malloc_args margs_write;
249 	static struct objcache_malloc_args margs_vop;
250 
251 	int error;
252 	int mod;
253 
254 	error = 0;
255 	kmalloc_raise_limit(M_HAMMER2, 0);	/* unlimited */
256 
257 	/*
258 	 * hammer2_xop_nthreads must be a multiple of ncpus,
259 	 * minimum 2 * ncpus.
260 	 */
261 	mod = ncpus;
262 	hammer2_xop_mod = mod;
263 	hammer2_xop_nthreads = mod * 2;
264 	while (hammer2_xop_nthreads / mod < HAMMER2_XOPGROUPS_MIN ||
265 	       hammer2_xop_nthreads < HAMMER2_XOPTHREADS_MIN)
266 	{
267 		hammer2_xop_nthreads += mod;
268 	}
269 	hammer2_xop_sgroups = hammer2_xop_nthreads / mod / 2;
270 	hammer2_xop_xgroups = hammer2_xop_nthreads / mod - hammer2_xop_sgroups;
271 	hammer2_xop_xbase = hammer2_xop_sgroups * mod;
272 
273 	/*
274 	 * A large DIO cache is needed to retain dedup enablement masks.
275 	 * The bulkfree code clears related masks as part of the disk block
276 	 * recycling algorithm, preventing it from being used for a later
277 	 * dedup.
278 	 *
279 	 * NOTE: A large buffer cache can actually interfere with dedup
280 	 *	 operation because we dedup based on media physical buffers
281 	 *	 and not logical buffers.  Try to make the DIO case large
282 	 *	 enough to avoid this problem, but also cap it.
283 	 */
284 	hammer2_dio_limit = nbuf * 2;
285 	if (hammer2_dio_limit > 100000)
286 		hammer2_dio_limit = 100000;
287 
288 	if (HAMMER2_BLOCKREF_BYTES != sizeof(struct hammer2_blockref))
289 		error = EINVAL;
290 	if (HAMMER2_INODE_BYTES != sizeof(struct hammer2_inode_data))
291 		error = EINVAL;
292 	if (HAMMER2_VOLUME_BYTES != sizeof(struct hammer2_volume_data))
293 		error = EINVAL;
294 
295 	if (error)
296 		kprintf("HAMMER2 structure size mismatch; cannot continue.\n");
297 
298 	margs_read.objsize = 65536;
299 	margs_read.mtype = M_HAMMER2_DEBUFFER;
300 
301 	margs_write.objsize = 32768;
302 	margs_write.mtype = M_HAMMER2_CBUFFER;
303 
304 	margs_vop.objsize = sizeof(hammer2_xop_t);
305 	margs_vop.mtype = M_HAMMER2;
306 
307 	/*
308 	 * Note thaht for the XOPS cache we want backing store allocations
309 	 * to use M_ZERO.  This is not allowed in objcache_get() (to avoid
310 	 * confusion), so use the backing store function that does it.  This
311 	 * means that initial XOPS objects are zerod but REUSED objects are
312 	 * not.  So we are responsible for cleaning the object up sufficiently
313 	 * for our needs before objcache_put()ing it back (typically just the
314 	 * FIFO indices).
315 	 */
316 	cache_buffer_read = objcache_create(margs_read.mtype->ks_shortdesc,
317 				0, 1, NULL, NULL, NULL,
318 				objcache_malloc_alloc,
319 				objcache_malloc_free,
320 				&margs_read);
321 	cache_buffer_write = objcache_create(margs_write.mtype->ks_shortdesc,
322 				0, 1, NULL, NULL, NULL,
323 				objcache_malloc_alloc,
324 				objcache_malloc_free,
325 				&margs_write);
326 	cache_xops = objcache_create(margs_vop.mtype->ks_shortdesc,
327 				0, 1, NULL, NULL, NULL,
328 				objcache_malloc_alloc_zero,
329 				objcache_malloc_free,
330 				&margs_vop);
331 
332 
333 	lockinit(&hammer2_mntlk, "mntlk", 0, 0);
334 	TAILQ_INIT(&hammer2_mntlist);
335 	TAILQ_INIT(&hammer2_pfslist);
336 	TAILQ_INIT(&hammer2_spmplist);
337 
338 	hammer2_limit_dirty_chains = maxvnodes / 10;
339 	if (hammer2_limit_dirty_chains > HAMMER2_LIMIT_DIRTY_CHAINS)
340 		hammer2_limit_dirty_chains = HAMMER2_LIMIT_DIRTY_CHAINS;
341 	if (hammer2_limit_dirty_chains < 1000)
342 		hammer2_limit_dirty_chains = 1000;
343 
344 	hammer2_limit_dirty_inodes = maxvnodes / 25;
345 	if (hammer2_limit_dirty_inodes < 100)
346 		hammer2_limit_dirty_inodes = 100;
347 	if (hammer2_limit_dirty_inodes > HAMMER2_LIMIT_DIRTY_INODES)
348 		hammer2_limit_dirty_inodes = HAMMER2_LIMIT_DIRTY_INODES;
349 
350 	hammer2_limit_saved_chains = hammer2_limit_dirty_chains * 5;
351 
352 	return (error);
353 }
354 
355 static
356 int
357 hammer2_vfs_uninit(struct vfsconf *vfsp __unused)
358 {
359 	objcache_destroy(cache_buffer_read);
360 	objcache_destroy(cache_buffer_write);
361 	objcache_destroy(cache_xops);
362 	return 0;
363 }
364 
365 /*
366  * Core PFS allocator.  Used to allocate or reference the pmp structure
367  * for PFS cluster mounts and the spmp structure for media (hmp) structures.
368  * The pmp can be passed in or loaded by this function using the chain and
369  * inode data.
370  *
371  * pmp->modify_tid tracks new modify_tid transaction ids for front-end
372  * transactions.  Note that synchronization does not use this field.
373  * (typically frontend operations and synchronization cannot run on the
374  * same PFS node at the same time).
375  *
376  * XXX check locking
377  */
378 hammer2_pfs_t *
379 hammer2_pfsalloc(hammer2_chain_t *chain,
380 		 const hammer2_inode_data_t *ripdata,
381 		 hammer2_dev_t *force_local)
382 {
383 	hammer2_pfs_t *pmp;
384 	hammer2_inode_t *iroot;
385 	int count;
386 	int i;
387 	int j;
388 
389 	pmp = NULL;
390 
391 	/*
392 	 * Locate or create the PFS based on the cluster id.  If ripdata
393 	 * is NULL this is a spmp which is unique and is always allocated.
394 	 *
395 	 * If the device is mounted in local mode all PFSs are considered
396 	 * independent and not part of any cluster (for debugging only).
397 	 */
398 	if (ripdata) {
399 		TAILQ_FOREACH(pmp, &hammer2_pfslist, mntentry) {
400 			if (force_local != pmp->force_local)
401 				continue;
402 			if (force_local == NULL &&
403 			    bcmp(&pmp->pfs_clid, &ripdata->meta.pfs_clid,
404 				 sizeof(pmp->pfs_clid)) == 0) {
405 				break;
406 			} else if (force_local && pmp->pfs_names[0] &&
407 			    strcmp(pmp->pfs_names[0], (const char *)ripdata->filename) == 0) {
408 				break;
409 			}
410 		}
411 	}
412 
413 	if (pmp == NULL) {
414 		pmp = kmalloc(sizeof(*pmp), M_HAMMER2, M_WAITOK | M_ZERO);
415 		pmp->force_local = force_local;
416 		hammer2_trans_manage_init(pmp);
417 		kmalloc_create_obj(&pmp->minode, "HAMMER2-inodes",
418 				   sizeof(struct hammer2_inode));
419 		lockinit(&pmp->lock, "pfslk", 0, 0);
420 		hammer2_spin_init(&pmp->inum_spin, "hm2pfsalloc_inum");
421 		hammer2_spin_init(&pmp->xop_spin, "h2xop");
422 		hammer2_spin_init(&pmp->lru_spin, "h2lru");
423 		RB_INIT(&pmp->inum_tree);
424 		TAILQ_INIT(&pmp->syncq);
425 		TAILQ_INIT(&pmp->depq);
426 		TAILQ_INIT(&pmp->lru_list);
427 		hammer2_spin_init(&pmp->list_spin, "h2pfsalloc_list");
428 
429 		/*
430 		 * Save the last media transaction id for the flusher.  Set
431 		 * initial
432 		 */
433 		if (ripdata) {
434 			pmp->pfs_clid = ripdata->meta.pfs_clid;
435 			TAILQ_INSERT_TAIL(&hammer2_pfslist, pmp, mntentry);
436 		} else {
437 			pmp->flags |= HAMMER2_PMPF_SPMP;
438 			TAILQ_INSERT_TAIL(&hammer2_spmplist, pmp, mntentry);
439 		}
440 
441 		/*
442 		 * The synchronization thread may start too early, make
443 		 * sure it stays frozen until we are ready to let it go.
444 		 * XXX
445 		 */
446 		/*
447 		pmp->primary_thr.flags = HAMMER2_THREAD_FROZEN |
448 					 HAMMER2_THREAD_REMASTER;
449 		*/
450 	}
451 
452 	/*
453 	 * Create the PFS's root inode and any missing XOP helper threads.
454 	 */
455 	if ((iroot = pmp->iroot) == NULL) {
456 		iroot = hammer2_inode_get(pmp, NULL, 1, -1);
457 		if (ripdata)
458 			iroot->meta = ripdata->meta;
459 		pmp->iroot = iroot;
460 		hammer2_inode_ref(iroot);
461 		hammer2_inode_unlock(iroot);
462 	}
463 
464 	/*
465 	 * Stop here if no chain is passed in.
466 	 */
467 	if (chain == NULL)
468 		goto done;
469 
470 	/*
471 	 * When a chain is passed in we must add it to the PFS's root
472 	 * inode, update pmp->pfs_types[], and update the syncronization
473 	 * threads.
474 	 *
475 	 * When forcing local mode, mark the PFS as a MASTER regardless.
476 	 *
477 	 * At the moment empty spots can develop due to removals or failures.
478 	 * Ultimately we want to re-fill these spots but doing so might
479 	 * confused running code. XXX
480 	 */
481 	hammer2_inode_ref(iroot);
482 	hammer2_mtx_ex(&iroot->lock);
483 	j = iroot->cluster.nchains;
484 
485 	if (j == HAMMER2_MAXCLUSTER) {
486 		kprintf("hammer2_pfsalloc: cluster full!\n");
487 		/* XXX fatal error? */
488 	} else {
489 		KKASSERT(chain->pmp == NULL);
490 		chain->pmp = pmp;
491 		hammer2_chain_ref(chain);
492 		iroot->cluster.array[j].chain = chain;
493 		if (force_local)
494 			pmp->pfs_types[j] = HAMMER2_PFSTYPE_MASTER;
495 		else
496 			pmp->pfs_types[j] = ripdata->meta.pfs_type;
497 		pmp->pfs_names[j] = kstrdup((const char *)ripdata->filename, M_HAMMER2);
498 		pmp->pfs_hmps[j] = chain->hmp;
499 		hammer2_spin_ex(&pmp->inum_spin);
500 		pmp->pfs_iroot_blocksets[j] = chain->data->ipdata.u.blockset;
501 		hammer2_spin_unex(&pmp->inum_spin);
502 
503 		/*
504 		 * If the PFS is already mounted we must account
505 		 * for the mount_count here.
506 		 */
507 		if (pmp->mp)
508 			++chain->hmp->mount_count;
509 
510 		/*
511 		 * May have to fixup dirty chain tracking.  Previous
512 		 * pmp was NULL so nothing to undo.
513 		 */
514 		if (chain->flags & HAMMER2_CHAIN_MODIFIED)
515 			hammer2_pfs_memory_inc(pmp);
516 		++j;
517 	}
518 	iroot->cluster.nchains = j;
519 
520 	/*
521 	 * Update nmasters from any PFS inode which is part of the cluster.
522 	 * It is possible that this will result in a value which is too
523 	 * high.  MASTER PFSs are authoritative for pfs_nmasters and will
524 	 * override this value later on.
525 	 *
526 	 * (This informs us of masters that might not currently be
527 	 *  discoverable by this mount).
528 	 */
529 	if (ripdata && pmp->pfs_nmasters < ripdata->meta.pfs_nmasters) {
530 		pmp->pfs_nmasters = ripdata->meta.pfs_nmasters;
531 	}
532 
533 	/*
534 	 * Count visible masters.  Masters are usually added with
535 	 * ripdata->meta.pfs_nmasters set to 1.  This detects when there
536 	 * are more (XXX and must update the master inodes).
537 	 */
538 	count = 0;
539 	for (i = 0; i < iroot->cluster.nchains; ++i) {
540 		if (pmp->pfs_types[i] == HAMMER2_PFSTYPE_MASTER)
541 			++count;
542 	}
543 	if (pmp->pfs_nmasters < count)
544 		pmp->pfs_nmasters = count;
545 
546 	/*
547 	 * Create missing synchronization and support threads.
548 	 *
549 	 * Single-node masters (including snapshots) have nothing to
550 	 * synchronize and do not require this thread.
551 	 *
552 	 * Multi-node masters or any number of soft masters, slaves, copy,
553 	 * or other PFS types need the thread.
554 	 *
555 	 * Each thread is responsible for its particular cluster index.
556 	 * We use independent threads so stalls or mismatches related to
557 	 * any given target do not affect other targets.
558 	 */
559 	for (i = 0; i < iroot->cluster.nchains; ++i) {
560 		/*
561 		 * Single-node masters (including snapshots) have nothing
562 		 * to synchronize and will make direct xops support calls,
563 		 * thus they do not require this thread.
564 		 *
565 		 * Note that there can be thousands of snapshots.  We do not
566 		 * want to create thousands of threads.
567 		 */
568 		if (pmp->pfs_nmasters <= 1 &&
569 		    pmp->pfs_types[i] == HAMMER2_PFSTYPE_MASTER) {
570 			continue;
571 		}
572 
573 		/*
574 		 * Sync support thread
575 		 */
576 		if (pmp->sync_thrs[i].td == NULL) {
577 			hammer2_thr_create(&pmp->sync_thrs[i], pmp, NULL,
578 					   "h2nod", i, -1,
579 					   hammer2_primary_sync_thread);
580 		}
581 	}
582 
583 	/*
584 	 * Create missing Xop threads
585 	 *
586 	 * NOTE: We create helper threads for all mounted PFSs or any
587 	 *	 PFSs with 2+ nodes (so the sync thread can update them,
588 	 *	 even if not mounted).
589 	 */
590 	if (pmp->mp || iroot->cluster.nchains >= 2)
591 		hammer2_xop_helper_create(pmp);
592 
593 	hammer2_mtx_unlock(&iroot->lock);
594 	hammer2_inode_drop(iroot);
595 done:
596 	return pmp;
597 }
598 
599 /*
600  * Deallocate an element of a probed PFS.  If destroying and this is a
601  * MASTER, adjust nmasters.
602  *
603  * This function does not physically destroy the PFS element in its device
604  * under the super-root  (see hammer2_ioctl_pfs_delete()).
605  */
606 void
607 hammer2_pfsdealloc(hammer2_pfs_t *pmp, int clindex, int destroying)
608 {
609 	hammer2_inode_t *iroot;
610 	hammer2_chain_t *chain;
611 	int j;
612 
613 	/*
614 	 * Cleanup our reference on iroot.  iroot is (should) not be needed
615 	 * by the flush code.
616 	 */
617 	iroot = pmp->iroot;
618 	if (iroot) {
619 		/*
620 		 * Stop synchronizing
621 		 *
622 		 * XXX flush after acquiring the iroot lock.
623 		 * XXX clean out the cluster index from all inode structures.
624 		 */
625 		hammer2_thr_delete(&pmp->sync_thrs[clindex]);
626 
627 		/*
628 		 * Remove the cluster index from the group.  If destroying
629 		 * the PFS and this is a master, adjust pfs_nmasters.
630 		 */
631 		hammer2_mtx_ex(&iroot->lock);
632 		chain = iroot->cluster.array[clindex].chain;
633 		iroot->cluster.array[clindex].chain = NULL;
634 
635 		switch(pmp->pfs_types[clindex]) {
636 		case HAMMER2_PFSTYPE_MASTER:
637 			if (destroying && pmp->pfs_nmasters > 0)
638 				--pmp->pfs_nmasters;
639 			/* XXX adjust ripdata->meta.pfs_nmasters */
640 			break;
641 		default:
642 			break;
643 		}
644 		pmp->pfs_types[clindex] = HAMMER2_PFSTYPE_NONE;
645 
646 		hammer2_mtx_unlock(&iroot->lock);
647 
648 		/*
649 		 * Release the chain.
650 		 */
651 		if (chain) {
652 			atomic_set_int(&chain->flags, HAMMER2_CHAIN_RELEASE);
653 			hammer2_chain_drop(chain);
654 		}
655 
656 		/*
657 		 * Terminate all XOP threads for the cluster index.
658 		 */
659 		if (pmp->xop_groups) {
660 			for (j = 0; j < hammer2_xop_nthreads; ++j) {
661 				hammer2_thr_delete(
662 					&pmp->xop_groups[j].thrs[clindex]);
663 			}
664 		}
665 	}
666 }
667 
668 /*
669  * Destroy a PFS, typically only occurs after the last mount on a device
670  * has gone away.
671  */
672 static void
673 hammer2_pfsfree(hammer2_pfs_t *pmp)
674 {
675 	hammer2_inode_t *iroot;
676 	hammer2_chain_t *chain;
677 	int chains_still_present = 0;
678 	int i;
679 	int j;
680 
681 	/*
682 	 * Cleanup our reference on iroot.  iroot is (should) not be needed
683 	 * by the flush code.
684 	 */
685 	if (pmp->flags & HAMMER2_PMPF_SPMP)
686 		TAILQ_REMOVE(&hammer2_spmplist, pmp, mntentry);
687 	else
688 		TAILQ_REMOVE(&hammer2_pfslist, pmp, mntentry);
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 	 * Clean up iroot
709 	 */
710 	iroot = pmp->iroot;
711 	if (iroot) {
712 		for (i = 0; i < iroot->cluster.nchains; ++i) {
713 			hammer2_thr_delete(&pmp->sync_thrs[i]);
714 			if (pmp->xop_groups) {
715 				for (j = 0; j < hammer2_xop_nthreads; ++j)
716 					hammer2_thr_delete(
717 						&pmp->xop_groups[j].thrs[i]);
718 			}
719 			chain = iroot->cluster.array[i].chain;
720 			if (chain && !RB_EMPTY(&chain->core.rbtree)) {
721 				kprintf("hammer2: Warning pmp %p still "
722 					"has active chains\n", pmp);
723 				chains_still_present = 1;
724 			}
725 		}
726 		KASSERT(iroot->refs == 1,
727 			("PMP->IROOT %p REFS WRONG %d", iroot, iroot->refs));
728 
729 		/* ref for iroot */
730 		hammer2_inode_drop(iroot);
731 		pmp->iroot = NULL;
732 	}
733 
734 	/*
735 	 * Free remaining pmp resources
736 	 */
737 	if (chains_still_present) {
738 		kprintf("hammer2: cannot free pmp %p, still in use\n", pmp);
739 	} else {
740 		kmalloc_destroy_obj(&pmp->minode);
741 		kfree(pmp, M_HAMMER2);
742 	}
743 }
744 
745 /*
746  * Remove all references to hmp from the pfs list.  Any PFS which becomes
747  * empty is terminated and freed.
748  *
749  * XXX inefficient.
750  */
751 static void
752 hammer2_pfsfree_scan(hammer2_dev_t *hmp, int which)
753 {
754 	hammer2_pfs_t *pmp;
755 	hammer2_inode_t *iroot;
756 	hammer2_chain_t *rchain;
757 	int i;
758 	int j;
759 	struct hammer2_pfslist *wlist;
760 
761 	if (which == 0)
762 		wlist = &hammer2_pfslist;
763 	else
764 		wlist = &hammer2_spmplist;
765 again:
766 	TAILQ_FOREACH(pmp, wlist, mntentry) {
767 		if ((iroot = pmp->iroot) == NULL)
768 			continue;
769 
770 		/*
771 		 * Determine if this PFS is affected.  If it is we must
772 		 * freeze all management threads and lock its iroot.
773 		 *
774 		 * Freezing a management thread forces it idle, operations
775 		 * in-progress will be aborted and it will have to start
776 		 * over again when unfrozen, or exit if told to exit.
777 		 */
778 		for (i = 0; i < HAMMER2_MAXCLUSTER; ++i) {
779 			if (pmp->pfs_hmps[i] == hmp)
780 				break;
781 		}
782 		if (i == HAMMER2_MAXCLUSTER)
783 			continue;
784 
785 		hammer2_vfs_sync_pmp(pmp, MNT_WAIT);
786 
787 		/*
788 		 * Make sure all synchronization threads are locked
789 		 * down.
790 		 */
791 		for (i = 0; i < HAMMER2_MAXCLUSTER; ++i) {
792 			if (pmp->pfs_hmps[i] == NULL)
793 				continue;
794 			hammer2_thr_freeze_async(&pmp->sync_thrs[i]);
795 			if (pmp->xop_groups) {
796 				for (j = 0; j < hammer2_xop_nthreads; ++j) {
797 					hammer2_thr_freeze_async(
798 						&pmp->xop_groups[j].thrs[i]);
799 				}
800 			}
801 		}
802 		for (i = 0; i < HAMMER2_MAXCLUSTER; ++i) {
803 			if (pmp->pfs_hmps[i] == NULL)
804 				continue;
805 			hammer2_thr_freeze(&pmp->sync_thrs[i]);
806 			if (pmp->xop_groups) {
807 				for (j = 0; j < hammer2_xop_nthreads; ++j) {
808 					hammer2_thr_freeze(
809 						&pmp->xop_groups[j].thrs[i]);
810 				}
811 			}
812 		}
813 
814 		/*
815 		 * Lock the inode and clean out matching chains.
816 		 * Note that we cannot use hammer2_inode_lock_*()
817 		 * here because that would attempt to validate the
818 		 * cluster that we are in the middle of ripping
819 		 * apart.
820 		 *
821 		 * WARNING! We are working directly on the inodes
822 		 *	    embedded cluster.
823 		 */
824 		hammer2_mtx_ex(&iroot->lock);
825 
826 		/*
827 		 * Remove the chain from matching elements of the PFS.
828 		 */
829 		for (i = 0; i < HAMMER2_MAXCLUSTER; ++i) {
830 			if (pmp->pfs_hmps[i] != hmp)
831 				continue;
832 			hammer2_thr_delete(&pmp->sync_thrs[i]);
833 			if (pmp->xop_groups) {
834 				for (j = 0; j < hammer2_xop_nthreads; ++j) {
835 					hammer2_thr_delete(
836 						&pmp->xop_groups[j].thrs[i]);
837 				}
838 			}
839 			rchain = iroot->cluster.array[i].chain;
840 			iroot->cluster.array[i].chain = NULL;
841 			pmp->pfs_types[i] = HAMMER2_PFSTYPE_NONE;
842 			if (pmp->pfs_names[i]) {
843 				kfree(pmp->pfs_names[i], M_HAMMER2);
844 				pmp->pfs_names[i] = NULL;
845 			}
846 			if (rchain) {
847 				hammer2_chain_drop(rchain);
848 				/* focus hint */
849 				if (iroot->cluster.focus == rchain)
850 					iroot->cluster.focus = NULL;
851 			}
852 			pmp->pfs_hmps[i] = NULL;
853 		}
854 		hammer2_mtx_unlock(&iroot->lock);
855 
856 		/*
857 		 * Cleanup trailing chains.  Gaps may remain.
858 		 */
859 		for (i = HAMMER2_MAXCLUSTER - 1; i >= 0; --i) {
860 			if (pmp->pfs_hmps[i])
861 				break;
862 		}
863 		iroot->cluster.nchains = i + 1;
864 
865 		/*
866 		 * If the PMP has no elements remaining we can destroy it.
867 		 * (this will transition management threads from frozen->exit).
868 		 */
869 		if (iroot->cluster.nchains == 0) {
870 			/*
871 			 * If this was the hmp's spmp, we need to clean
872 			 * a little more stuff out.
873 			 */
874 			if (hmp->spmp == pmp) {
875 				hmp->spmp = NULL;
876 				hmp->vchain.pmp = NULL;
877 				hmp->fchain.pmp = NULL;
878 			}
879 
880 			/*
881 			 * Free the pmp and restart the loop
882 			 */
883 			KKASSERT(TAILQ_EMPTY(&pmp->syncq));
884 			KKASSERT(TAILQ_EMPTY(&pmp->depq));
885 			hammer2_pfsfree(pmp);
886 			goto again;
887 		}
888 
889 		/*
890 		 * If elements still remain we need to set the REMASTER
891 		 * flag and unfreeze it.
892 		 */
893 		for (i = 0; i < HAMMER2_MAXCLUSTER; ++i) {
894 			if (pmp->pfs_hmps[i] == NULL)
895 				continue;
896 			hammer2_thr_remaster(&pmp->sync_thrs[i]);
897 			hammer2_thr_unfreeze(&pmp->sync_thrs[i]);
898 			if (pmp->xop_groups) {
899 				for (j = 0; j < hammer2_xop_nthreads; ++j) {
900 					hammer2_thr_remaster(
901 						&pmp->xop_groups[j].thrs[i]);
902 					hammer2_thr_unfreeze(
903 						&pmp->xop_groups[j].thrs[i]);
904 				}
905 			}
906 		}
907 	}
908 }
909 
910 /*
911  * Mount or remount HAMMER2 fileystem from physical media
912  *
913  *	mountroot
914  *		mp		mount point structure
915  *		path		NULL
916  *		data		<unused>
917  *		cred		<unused>
918  *
919  *	mount
920  *		mp		mount point structure
921  *		path		path to mount point
922  *		data		pointer to argument structure in user space
923  *			volume	volume path (device@LABEL form)
924  *			hflags	user mount flags
925  *		cred		user credentials
926  *
927  * RETURNS:	0	Success
928  *		!0	error number
929  */
930 static
931 int
932 hammer2_vfs_mount(struct mount *mp, char *path, caddr_t data,
933 		  struct ucred *cred)
934 {
935 	struct hammer2_mount_info info;
936 	hammer2_pfs_t *pmp;
937 	hammer2_pfs_t *spmp;
938 	hammer2_dev_t *hmp, *hmp_tmp;
939 	hammer2_dev_t *force_local;
940 	hammer2_key_t key_next;
941 	hammer2_key_t key_dummy;
942 	hammer2_key_t lhc;
943 	hammer2_chain_t *parent;
944 	hammer2_chain_t *chain;
945 	const hammer2_inode_data_t *ripdata;
946 	hammer2_devvp_list_t devvpl;
947 	hammer2_devvp_t *e, *e_tmp;
948 	struct file *fp;
949 	char devstr[MNAMELEN];
950 	size_t size;
951 	size_t done;
952 	char *label;
953 	int ronly = ((mp->mnt_flag & MNT_RDONLY) != 0);
954 	int error;
955 	int i;
956 
957 	hmp = NULL;
958 	pmp = NULL;
959 	label = NULL;
960 	bzero(&info, sizeof(info));
961 
962 	if (path) {
963 		/*
964 		 * Non-root mount or updating a mount
965 		 */
966 		error = copyin(data, &info, sizeof(info));
967 		if (error)
968 			return (error);
969 	}
970 
971 	if (mp->mnt_flag & MNT_UPDATE) {
972 		/*
973 		 * Update mount.  Note that pmp->iroot->cluster is
974 		 * an inode-embedded cluster and thus cannot be
975 		 * directly locked.
976 		 *
977 		 * XXX HAMMER2 needs to implement NFS export via
978 		 *     mountctl.
979 		 */
980 		hammer2_cluster_t *cluster;
981 
982 		error = 0;
983 		pmp = MPTOPMP(mp);
984 		pmp->hflags = info.hflags;
985 		cluster = &pmp->iroot->cluster;
986 		for (i = 0; i < cluster->nchains; ++i) {
987 			if (cluster->array[i].chain == NULL)
988 				continue;
989 			hmp = cluster->array[i].chain->hmp;
990 			error = hammer2_remount(hmp, mp, path, cred);
991 			if (error)
992 				break;
993 		}
994 
995 		return error;
996 	}
997 
998 	if (path == NULL) {
999 		/*
1000 		 * Root mount
1001 		 */
1002 		info.cluster_fd = -1;
1003 		ksnprintf(devstr, sizeof(devstr), "%s",
1004 			  mp->mnt_stat.f_mntfromname);
1005 		done = strlen(devstr) + 1;
1006 		kprintf("hammer2_mount: root devstr=\"%s\"\n", devstr);
1007 	} else {
1008 		error = copyinstr(info.volume, devstr, MNAMELEN - 1, &done);
1009 		if (error)
1010 			return (error);
1011 		kprintf("hammer2_mount: devstr=\"%s\"\n", devstr);
1012 	}
1013 
1014 	/*
1015 	 * Extract device and label, automatically mount @BOOT, @ROOT, or @DATA
1016 	 * if no label specified, based on the partition id.  Error out if no
1017 	 * label or device (with partition id) is specified.  This is strictly
1018 	 * a convenience to match the default label created by newfs_hammer2,
1019 	 * our preference is that a label always be specified.
1020 	 *
1021 	 * NOTE: We allow 'mount @LABEL <blah>'... that is, a mount command
1022 	 *	 that does not specify a device, as long as some H2 label
1023 	 *	 has already been mounted from that device.  This makes
1024 	 *	 mounting snapshots a lot easier.
1025 	 */
1026 	label = strchr(devstr, '@');
1027 	if (label && ((label + 1) - devstr) > done) {
1028 		kprintf("hammer2_mount: bad label %s/%zd\n", devstr, done);
1029 		return (EINVAL);
1030 	}
1031 	if (label == NULL || label[1] == 0) {
1032 		char slice;
1033 
1034 		if (label == NULL)
1035 			label = devstr + strlen(devstr);
1036 		else
1037 			*label = '\0';		/* clean up trailing @ */
1038 
1039 		slice = label[-1];
1040 		switch(slice) {
1041 		case 'a':
1042 			label = "BOOT";
1043 			break;
1044 		case 'd':
1045 			label = "ROOT";
1046 			break;
1047 		default:
1048 			label = "DATA";
1049 			break;
1050 		}
1051 	} else {
1052 		*label = '\0';
1053 		label++;
1054 	}
1055 
1056 	kprintf("hammer2_mount: device=\"%s\" label=\"%s\" rdonly=%d\n",
1057 		devstr, label, ronly);
1058 
1059 	/*
1060 	 * Initialize all device vnodes.
1061 	 */
1062 	TAILQ_INIT(&devvpl);
1063 	error = hammer2_init_devvp(devstr, path == NULL, &devvpl);
1064 	if (error) {
1065 		kprintf("hammer2: failed to initialize devvp in %s\n", devstr);
1066 		hammer2_cleanup_devvp(&devvpl);
1067 		return error;
1068 	}
1069 
1070 	/*
1071 	 * Determine if the device has already been mounted.  After this
1072 	 * check hmp will be non-NULL if we are doing the second or more
1073 	 * hammer2 mounts from the same device.
1074 	 */
1075 	lockmgr(&hammer2_mntlk, LK_EXCLUSIVE);
1076 	if (!TAILQ_EMPTY(&devvpl)) {
1077 		/*
1078 		 * Match the device.  Due to the way devfs works,
1079 		 * we may not be able to directly match the vnode pointer,
1080 		 * so also check to see if the underlying device matches.
1081 		 */
1082 		TAILQ_FOREACH(hmp_tmp, &hammer2_mntlist, mntentry) {
1083 			TAILQ_FOREACH(e_tmp, &hmp_tmp->devvpl, entry) {
1084 				int devvp_found = 0;
1085 				TAILQ_FOREACH(e, &devvpl, entry) {
1086 					KKASSERT(e->devvp);
1087 					if (e_tmp->devvp == e->devvp)
1088 						devvp_found = 1;
1089 					if (e_tmp->devvp->v_rdev &&
1090 					    e_tmp->devvp->v_rdev == e->devvp->v_rdev)
1091 						devvp_found = 1;
1092 				}
1093 				if (!devvp_found)
1094 					goto next_hmp;
1095 			}
1096 			hmp = hmp_tmp;
1097 			kprintf("hammer2_mount: hmp=%p matched\n", hmp);
1098 			break;
1099 next_hmp:
1100 			continue;
1101 		}
1102 
1103 		/*
1104 		 * If no match this may be a fresh H2 mount, make sure
1105 		 * the device is not mounted on anything else.
1106 		 */
1107 		if (hmp == NULL) {
1108 			TAILQ_FOREACH(e, &devvpl, entry) {
1109 				struct vnode *devvp = e->devvp;
1110 				KKASSERT(devvp);
1111 				error = vfs_mountedon(devvp);
1112 				if (error) {
1113 					kprintf("hammer2_mount: %s mounted %d\n",
1114 						e->path, error);
1115 					hammer2_cleanup_devvp(&devvpl);
1116 					lockmgr(&hammer2_mntlk, LK_RELEASE);
1117 					return error;
1118 				}
1119 			}
1120 		}
1121 	} else {
1122 		/*
1123 		 * Match the label to a pmp already probed.
1124 		 */
1125 		TAILQ_FOREACH(pmp, &hammer2_pfslist, mntentry) {
1126 			for (i = 0; i < HAMMER2_MAXCLUSTER; ++i) {
1127 				if (pmp->pfs_names[i] &&
1128 				    strcmp(pmp->pfs_names[i], label) == 0) {
1129 					hmp = pmp->pfs_hmps[i];
1130 					break;
1131 				}
1132 			}
1133 			if (hmp)
1134 				break;
1135 		}
1136 		if (hmp == NULL) {
1137 			kprintf("hammer2_mount: PFS label \"%s\" not found\n",
1138 				label);
1139 			hammer2_cleanup_devvp(&devvpl);
1140 			lockmgr(&hammer2_mntlk, LK_RELEASE);
1141 			return ENOENT;
1142 		}
1143 	}
1144 
1145 	/*
1146 	 * Open the device if this isn't a secondary mount and construct
1147 	 * the H2 device mount (hmp).
1148 	 */
1149 	if (hmp == NULL) {
1150 		hammer2_chain_t *schain;
1151 		hammer2_xop_head_t xop;
1152 
1153 		/*
1154 		 * Now open the device
1155 		 */
1156 		KKASSERT(!TAILQ_EMPTY(&devvpl));
1157 		error = hammer2_open_devvp(&devvpl, ronly);
1158 		if (error) {
1159 			hammer2_close_devvp(&devvpl, ronly);
1160 			hammer2_cleanup_devvp(&devvpl);
1161 			lockmgr(&hammer2_mntlk, LK_RELEASE);
1162 			return error;
1163 		}
1164 
1165 		/*
1166 		 * Construct volumes and link with device vnodes.
1167 		 */
1168 		hmp = kmalloc(sizeof(*hmp), M_HAMMER2, M_WAITOK | M_ZERO);
1169 		hmp->devvp = NULL;
1170 		error = hammer2_init_volumes(mp, &devvpl, hmp->volumes,
1171 					     &hmp->voldata, &hmp->volhdrno,
1172 					     &hmp->devvp);
1173 		if (error) {
1174 			hammer2_close_devvp(&devvpl, ronly);
1175 			hammer2_cleanup_devvp(&devvpl);
1176 			lockmgr(&hammer2_mntlk, LK_RELEASE);
1177 			kfree(hmp, M_HAMMER2);
1178 			return error;
1179 		}
1180 		if (!hmp->devvp) {
1181 			kprintf("hammer2: failed to initialize root volume\n");
1182 			hammer2_unmount_helper(mp, NULL, hmp);
1183 			lockmgr(&hammer2_mntlk, LK_RELEASE);
1184 			hammer2_vfs_unmount(mp, MNT_FORCE);
1185 			return EINVAL;
1186 		}
1187 
1188 		ksnprintf(hmp->devrepname, sizeof(hmp->devrepname), "%s", devstr);
1189 		hmp->ronly = ronly;
1190 		hmp->hflags = info.hflags & HMNT2_DEVFLAGS;
1191 		kmalloc_create_obj(&hmp->mchain, "HAMMER2-chains",
1192 				   sizeof(struct hammer2_chain));
1193 		kmalloc_create_obj(&hmp->mio, "HAMMER2-dio",
1194 				   sizeof(struct hammer2_io));
1195 		kmalloc_create(&hmp->mmsg, "HAMMER2-msg");
1196 		TAILQ_INSERT_TAIL(&hammer2_mntlist, hmp, mntentry);
1197 		RB_INIT(&hmp->iotree);
1198 		hammer2_spin_init(&hmp->io_spin, "h2mount_io");
1199 		hammer2_spin_init(&hmp->list_spin, "h2mount_list");
1200 
1201 		lockinit(&hmp->vollk, "h2vol", 0, 0);
1202 		lockinit(&hmp->bulklk, "h2bulk", 0, 0);
1203 		lockinit(&hmp->bflock, "h2bflk", 0, 0);
1204 
1205 		/*
1206 		 * vchain setup. vchain.data is embedded.
1207 		 * vchain.refs is initialized and will never drop to 0.
1208 		 */
1209 		hmp->vchain.hmp = hmp;
1210 		hmp->vchain.refs = 1;
1211 		hmp->vchain.data = (void *)&hmp->voldata;
1212 		hmp->vchain.bref.type = HAMMER2_BREF_TYPE_VOLUME;
1213 		hmp->vchain.bref.data_off = 0 | HAMMER2_PBUFRADIX;
1214 		hmp->vchain.bref.mirror_tid = hmp->voldata.mirror_tid;
1215 		hammer2_chain_init(&hmp->vchain);
1216 
1217 		/*
1218 		 * fchain setup.  fchain.data is embedded.
1219 		 * fchain.refs is initialized and will never drop to 0.
1220 		 *
1221 		 * The data is not used but needs to be initialized to
1222 		 * pass assertion muster.  We use this chain primarily
1223 		 * as a placeholder for the freemap's top-level radix tree
1224 		 * so it does not interfere with the volume's topology
1225 		 * radix tree.
1226 		 */
1227 		hmp->fchain.hmp = hmp;
1228 		hmp->fchain.refs = 1;
1229 		hmp->fchain.data = (void *)&hmp->voldata.freemap_blockset;
1230 		hmp->fchain.bref.type = HAMMER2_BREF_TYPE_FREEMAP;
1231 		hmp->fchain.bref.data_off = 0 | HAMMER2_PBUFRADIX;
1232 		hmp->fchain.bref.mirror_tid = hmp->voldata.freemap_tid;
1233 		hmp->fchain.bref.methods =
1234 			HAMMER2_ENC_CHECK(HAMMER2_CHECK_FREEMAP) |
1235 			HAMMER2_ENC_COMP(HAMMER2_COMP_NONE);
1236 		hammer2_chain_init(&hmp->fchain);
1237 
1238 		/*
1239 		 * Initialize volume header related fields.
1240 		 */
1241 		KKASSERT(hmp->voldata.magic == HAMMER2_VOLUME_ID_HBO ||
1242 			 hmp->voldata.magic == HAMMER2_VOLUME_ID_ABO);
1243 		hmp->volsync = hmp->voldata;
1244 		hmp->free_reserved = hmp->voldata.allocator_size / 20;
1245 		/*
1246 		 * Must use hmp instead of volume header for these two
1247 		 * in order to handle volume versions transparently.
1248 		 */
1249 		if (hmp->voldata.version >= HAMMER2_VOL_VERSION_MULTI_VOLUMES) {
1250 			hmp->nvolumes = hmp->voldata.nvolumes;
1251 			hmp->total_size = hmp->voldata.total_size;
1252 		} else {
1253 			hmp->nvolumes = 1;
1254 			hmp->total_size = hmp->voldata.volu_size;
1255 		}
1256 		KKASSERT(hmp->nvolumes > 0);
1257 
1258 		/*
1259 		 * Move devvpl entries to hmp.
1260 		 */
1261 		TAILQ_INIT(&hmp->devvpl);
1262 		while ((e = TAILQ_FIRST(&devvpl)) != NULL) {
1263 			TAILQ_REMOVE(&devvpl, e, entry);
1264 			TAILQ_INSERT_TAIL(&hmp->devvpl, e, entry);
1265 		}
1266 		KKASSERT(TAILQ_EMPTY(&devvpl));
1267 		KKASSERT(!TAILQ_EMPTY(&hmp->devvpl));
1268 
1269 		/*
1270 		 * Really important to get these right or the flush and
1271 		 * teardown code will get confused.
1272 		 */
1273 		hmp->spmp = hammer2_pfsalloc(NULL, NULL, NULL);
1274 		spmp = hmp->spmp;
1275 		spmp->pfs_hmps[0] = hmp;
1276 
1277 		/*
1278 		 * Dummy-up vchain and fchain's modify_tid.  mirror_tid
1279 		 * is inherited from the volume header.
1280 		 */
1281 		hmp->vchain.bref.mirror_tid = hmp->voldata.mirror_tid;
1282 		hmp->vchain.bref.modify_tid = hmp->vchain.bref.mirror_tid;
1283 		hmp->vchain.pmp = spmp;
1284 		hmp->fchain.bref.mirror_tid = hmp->voldata.freemap_tid;
1285 		hmp->fchain.bref.modify_tid = hmp->fchain.bref.mirror_tid;
1286 		hmp->fchain.pmp = spmp;
1287 
1288 		/*
1289 		 * First locate the super-root inode, which is key 0
1290 		 * relative to the volume header's blockset.
1291 		 *
1292 		 * Then locate the root inode by scanning the directory keyspace
1293 		 * represented by the label.
1294 		 */
1295 		parent = hammer2_chain_lookup_init(&hmp->vchain, 0);
1296 		schain = hammer2_chain_lookup(&parent, &key_dummy,
1297 				      HAMMER2_SROOT_KEY, HAMMER2_SROOT_KEY,
1298 				      &error, 0);
1299 		hammer2_chain_lookup_done(parent);
1300 		if (schain == NULL) {
1301 			kprintf("hammer2_mount: invalid super-root\n");
1302 			hammer2_unmount_helper(mp, NULL, hmp);
1303 			lockmgr(&hammer2_mntlk, LK_RELEASE);
1304 			hammer2_vfs_unmount(mp, MNT_FORCE);
1305 			return EINVAL;
1306 		}
1307 		if (schain->error) {
1308 			kprintf("hammer2_mount: error %s reading super-root\n",
1309 				hammer2_error_str(schain->error));
1310 			hammer2_chain_unlock(schain);
1311 			hammer2_chain_drop(schain);
1312 			schain = NULL;
1313 			hammer2_unmount_helper(mp, NULL, hmp);
1314 			lockmgr(&hammer2_mntlk, LK_RELEASE);
1315 			hammer2_vfs_unmount(mp, MNT_FORCE);
1316 			return EINVAL;
1317 		}
1318 
1319 		/*
1320 		 * The super-root always uses an inode_tid of 1 when
1321 		 * creating PFSs.
1322 		 */
1323 		spmp->inode_tid = 1;
1324 		spmp->modify_tid = schain->bref.modify_tid + 1;
1325 
1326 		/*
1327 		 * Sanity-check schain's pmp and finish initialization.
1328 		 * Any chain belonging to the super-root topology should
1329 		 * have a NULL pmp (not even set to spmp).
1330 		 */
1331 		ripdata = &schain->data->ipdata;
1332 		KKASSERT(schain->pmp == NULL);
1333 		spmp->pfs_clid = ripdata->meta.pfs_clid;
1334 
1335 		/*
1336 		 * Replace the dummy spmp->iroot with a real one.  It's
1337 		 * easier to just do a wholesale replacement than to try
1338 		 * to update the chain and fixup the iroot fields.
1339 		 *
1340 		 * The returned inode is locked with the supplied cluster.
1341 		 */
1342 		hammer2_dummy_xop_from_chain(&xop, schain);
1343 		hammer2_inode_drop(spmp->iroot);
1344 		spmp->iroot = hammer2_inode_get(spmp, &xop, -1, -1);
1345 		spmp->spmp_hmp = hmp;
1346 		spmp->pfs_types[0] = ripdata->meta.pfs_type;
1347 		spmp->pfs_hmps[0] = hmp;
1348 		hammer2_inode_ref(spmp->iroot);
1349 		hammer2_inode_unlock(spmp->iroot);
1350 		hammer2_cluster_unlock(&xop.cluster);
1351 		hammer2_chain_drop(schain);
1352 		/* do not call hammer2_cluster_drop() on an embedded cluster */
1353 		schain = NULL;	/* now invalid */
1354 		/* leave spmp->iroot with one ref */
1355 
1356 		if (!hmp->ronly) {
1357 			error = hammer2_recovery(hmp);
1358 			if (error == 0)
1359 				error |= hammer2_fixup_pfses(hmp);
1360 			/* XXX do something with error */
1361 		}
1362 		hammer2_update_pmps(hmp);
1363 		hammer2_iocom_init(hmp);
1364 		hammer2_bulkfree_init(hmp);
1365 
1366 		/*
1367 		 * Ref the cluster management messaging descriptor.  The mount
1368 		 * program deals with the other end of the communications pipe.
1369 		 *
1370 		 * Root mounts typically do not supply one.
1371 		 */
1372 		if (info.cluster_fd >= 0) {
1373 			fp = holdfp(curthread, info.cluster_fd, -1);
1374 			if (fp) {
1375 				hammer2_cluster_reconnect(hmp, fp);
1376 			} else {
1377 				kprintf("hammer2_mount: bad cluster_fd!\n");
1378 			}
1379 		}
1380 	} else {
1381 		/* hmp->devvp_list is already constructed. */
1382 		hammer2_cleanup_devvp(&devvpl);
1383 		spmp = hmp->spmp;
1384 		if (info.hflags & HMNT2_DEVFLAGS) {
1385 			kprintf("hammer2_mount: Warning: mount flags pertaining "
1386 				"to the whole device may only be specified "
1387 				"on the first mount of the device: %08x\n",
1388 				info.hflags & HMNT2_DEVFLAGS);
1389 		}
1390 	}
1391 
1392 	/*
1393 	 * Force local mount (disassociate all PFSs from their clusters).
1394 	 * Used primarily for debugging.
1395 	 */
1396 	force_local = (hmp->hflags & HMNT2_LOCAL) ? hmp : NULL;
1397 
1398 	/*
1399 	 * Lookup the mount point under the media-localized super-root.
1400 	 * Scanning hammer2_pfslist doesn't help us because it represents
1401 	 * PFS cluster ids which can aggregate several named PFSs together.
1402 	 *
1403 	 * cluster->pmp will incorrectly point to spmp and must be fixed
1404 	 * up later on.
1405 	 */
1406 	hammer2_inode_lock(spmp->iroot, 0);
1407 	parent = hammer2_inode_chain(spmp->iroot, 0, HAMMER2_RESOLVE_ALWAYS);
1408 	lhc = hammer2_dirhash(label, strlen(label));
1409 	chain = hammer2_chain_lookup(&parent, &key_next,
1410 				     lhc, lhc + HAMMER2_DIRHASH_LOMASK,
1411 				     &error, 0);
1412 	while (chain) {
1413 		if (chain->bref.type == HAMMER2_BREF_TYPE_INODE &&
1414 		    strcmp(label, (char *)chain->data->ipdata.filename) == 0) {
1415 			break;
1416 		}
1417 		chain = hammer2_chain_next(&parent, chain, &key_next,
1418 					    key_next,
1419 					    lhc + HAMMER2_DIRHASH_LOMASK,
1420 					    &error, 0);
1421 	}
1422 	if (parent) {
1423 		hammer2_chain_unlock(parent);
1424 		hammer2_chain_drop(parent);
1425 	}
1426 	hammer2_inode_unlock(spmp->iroot);
1427 
1428 	/*
1429 	 * PFS could not be found?
1430 	 */
1431 	if (chain == NULL) {
1432 		hammer2_unmount_helper(mp, NULL, hmp);
1433 		lockmgr(&hammer2_mntlk, LK_RELEASE);
1434 		hammer2_vfs_unmount(mp, MNT_FORCE);
1435 
1436 		if (error) {
1437 			kprintf("hammer2_mount: PFS label I/O error\n");
1438 			return EINVAL;
1439 		} else {
1440 			kprintf("hammer2_mount: PFS label \"%s\" not found\n",
1441 				label);
1442 			return ENOENT;
1443 		}
1444 	}
1445 
1446 	/*
1447 	 * Acquire the pmp structure (it should have already been allocated
1448 	 * via hammer2_update_pmps()).
1449 	 */
1450 	if (chain->error) {
1451 		kprintf("hammer2_mount: PFS label I/O error\n");
1452 	} else {
1453 		ripdata = &chain->data->ipdata;
1454 		pmp = hammer2_pfsalloc(NULL, ripdata, force_local);
1455 	}
1456 	hammer2_chain_unlock(chain);
1457 	hammer2_chain_drop(chain);
1458 
1459 	/*
1460 	 * PFS to mount must exist at this point.
1461 	 */
1462 	if (pmp == NULL) {
1463 		kprintf("hammer2_mount: Failed to acquire PFS structure\n");
1464 		hammer2_unmount_helper(mp, NULL, hmp);
1465 		lockmgr(&hammer2_mntlk, LK_RELEASE);
1466 		hammer2_vfs_unmount(mp, MNT_FORCE);
1467 		return EINVAL;
1468 	}
1469 
1470 	/*
1471 	 * Finish the mount
1472 	 */
1473 	kprintf("hammer2_mount: hmp=%p pmp=%p\n", hmp, pmp);
1474 
1475 	/* Check if the pmp has already been mounted. */
1476 	if (pmp->mp) {
1477 		kprintf("hammer2_mount: PFS already mounted!\n");
1478 		hammer2_unmount_helper(mp, NULL, hmp);
1479 		lockmgr(&hammer2_mntlk, LK_RELEASE);
1480 		hammer2_vfs_unmount(mp, MNT_FORCE);
1481 		return EBUSY;
1482 	}
1483 
1484 	pmp->hflags = info.hflags;
1485 	mp->mnt_flag |= MNT_LOCAL;
1486 	mp->mnt_kern_flag |= MNTK_ALL_MPSAFE;   /* all entry pts are SMP */
1487 	mp->mnt_kern_flag |= MNTK_THR_SYNC;     /* new vsyncscan semantics */
1488 
1489 	/*
1490 	 * required mount structure initializations
1491 	 */
1492 	mp->mnt_stat.f_iosize = HAMMER2_PBUFSIZE;
1493 	mp->mnt_stat.f_bsize = HAMMER2_PBUFSIZE;
1494 
1495 	mp->mnt_vstat.f_frsize = HAMMER2_PBUFSIZE;
1496 	mp->mnt_vstat.f_bsize = HAMMER2_PBUFSIZE;
1497 
1498 	/*
1499 	 * Optional fields
1500 	 */
1501 	mp->mnt_iosize_max = MAXPHYS;
1502 
1503 	/*
1504 	 * Connect up mount pointers.
1505 	 */
1506 	hammer2_mount_helper(mp, pmp);
1507 	lockmgr(&hammer2_mntlk, LK_RELEASE);
1508 
1509 	/*
1510 	 * Finish setup
1511 	 */
1512 	vfs_getnewfsid(mp);
1513 	vfs_add_vnodeops(mp, &hammer2_vnode_vops, &mp->mnt_vn_norm_ops);
1514 	vfs_add_vnodeops(mp, &hammer2_spec_vops, &mp->mnt_vn_spec_ops);
1515 	vfs_add_vnodeops(mp, &hammer2_fifo_vops, &mp->mnt_vn_fifo_ops);
1516 
1517 	if (path) {
1518 		copyinstr(info.volume, mp->mnt_stat.f_mntfromname,
1519 			  MNAMELEN - 1, &size);
1520 		bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
1521 	} /* else root mount, already in there */
1522 
1523 	bzero(mp->mnt_stat.f_mntonname, sizeof(mp->mnt_stat.f_mntonname));
1524 	if (path) {
1525 		copyinstr(path, mp->mnt_stat.f_mntonname,
1526 			  sizeof(mp->mnt_stat.f_mntonname) - 1,
1527 			  &size);
1528 	} else {
1529 		/* root mount */
1530 		mp->mnt_stat.f_mntonname[0] = '/';
1531 	}
1532 
1533 	/*
1534 	 * Initial statfs to prime mnt_stat.
1535 	 */
1536 	hammer2_vfs_statfs(mp, &mp->mnt_stat, cred);
1537 
1538 	return 0;
1539 }
1540 
1541 /*
1542  * Scan PFSs under the super-root and create hammer2_pfs structures.
1543  */
1544 static
1545 void
1546 hammer2_update_pmps(hammer2_dev_t *hmp)
1547 {
1548 	const hammer2_inode_data_t *ripdata;
1549 	hammer2_chain_t *parent;
1550 	hammer2_chain_t *chain;
1551 	hammer2_dev_t *force_local;
1552 	hammer2_pfs_t *spmp;
1553 	hammer2_key_t key_next;
1554 	int error;
1555 
1556 	/*
1557 	 * Force local mount (disassociate all PFSs from their clusters).
1558 	 * Used primarily for debugging.
1559 	 */
1560 	force_local = (hmp->hflags & HMNT2_LOCAL) ? hmp : NULL;
1561 
1562 	/*
1563 	 * Lookup mount point under the media-localized super-root.
1564 	 *
1565 	 * cluster->pmp will incorrectly point to spmp and must be fixed
1566 	 * up later on.
1567 	 */
1568 	spmp = hmp->spmp;
1569 	hammer2_inode_lock(spmp->iroot, 0);
1570 	parent = hammer2_inode_chain(spmp->iroot, 0, HAMMER2_RESOLVE_ALWAYS);
1571 	chain = hammer2_chain_lookup(&parent, &key_next,
1572 					 HAMMER2_KEY_MIN, HAMMER2_KEY_MAX,
1573 					 &error, 0);
1574 	while (chain) {
1575 		if (chain->error) {
1576 			kprintf("I/O error scanning PFS labels\n");
1577 		} else if (chain->bref.type != HAMMER2_BREF_TYPE_INODE) {
1578 			kprintf("Non inode chain type %d under super-root\n",
1579 				chain->bref.type);
1580 		} else {
1581 			ripdata = &chain->data->ipdata;
1582 			hammer2_pfsalloc(chain, ripdata, force_local);
1583 		}
1584 		chain = hammer2_chain_next(&parent, chain, &key_next,
1585 					   key_next, HAMMER2_KEY_MAX,
1586 					   &error, 0);
1587 	}
1588 	if (parent) {
1589 		hammer2_chain_unlock(parent);
1590 		hammer2_chain_drop(parent);
1591 	}
1592 	hammer2_inode_unlock(spmp->iroot);
1593 }
1594 
1595 static
1596 int
1597 hammer2_remount(hammer2_dev_t *hmp, struct mount *mp, char *path __unused,
1598 		struct ucred *cred)
1599 {
1600 	hammer2_volume_t *vol;
1601 	struct vnode *devvp;
1602 	int i, error, result = 0;
1603 
1604 	if (!(hmp->ronly && (mp->mnt_kern_flag & MNTK_WANTRDWR)))
1605 		return 0;
1606 
1607 	for (i = 0; i < hmp->nvolumes; ++i) {
1608 		vol = &hmp->volumes[i];
1609 		devvp = vol->dev->devvp;
1610 		KKASSERT(devvp);
1611 		vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
1612 		VOP_OPEN(devvp, FREAD | FWRITE, FSCRED, NULL);
1613 		vn_unlock(devvp);
1614 		error = 0;
1615 		if (vol->id == HAMMER2_ROOT_VOLUME) {
1616 			error = hammer2_recovery(hmp);
1617 			if (error == 0)
1618 				error |= hammer2_fixup_pfses(hmp);
1619 		}
1620 		vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
1621 		if (error == 0) {
1622 			VOP_CLOSE(devvp, FREAD, NULL);
1623 		} else {
1624 			VOP_CLOSE(devvp, FREAD | FWRITE, NULL);
1625 		}
1626 		vn_unlock(devvp);
1627 		result |= error;
1628 	}
1629 	if (result == 0) {
1630 		kprintf("hammer2: enable read/write\n");
1631 		hmp->ronly = 0;
1632 	}
1633 
1634 	return result;
1635 }
1636 
1637 static
1638 int
1639 hammer2_vfs_unmount(struct mount *mp, int mntflags)
1640 {
1641 	hammer2_pfs_t *pmp;
1642 	int flags;
1643 	int error = 0;
1644 
1645 	pmp = MPTOPMP(mp);
1646 
1647 	if (pmp == NULL)
1648 		return(0);
1649 
1650 	lockmgr(&hammer2_mntlk, LK_EXCLUSIVE);
1651 
1652 	/*
1653 	 * If mount initialization proceeded far enough we must flush
1654 	 * its vnodes and sync the underlying mount points.  Three syncs
1655 	 * are required to fully flush the filesystem (freemap updates lag
1656 	 * by one flush, and one extra for safety).
1657 	 */
1658 	if (mntflags & MNT_FORCE)
1659 		flags = FORCECLOSE;
1660 	else
1661 		flags = 0;
1662 	if (pmp->iroot) {
1663 		error = vflush(mp, 0, flags);
1664 		if (error)
1665 			goto failed;
1666 		hammer2_vfs_sync(mp, MNT_WAIT);
1667 		hammer2_vfs_sync(mp, MNT_WAIT);
1668 		hammer2_vfs_sync(mp, MNT_WAIT);
1669 	}
1670 
1671 	/*
1672 	 * Cleanup the frontend support XOPS threads
1673 	 */
1674 	hammer2_xop_helper_cleanup(pmp);
1675 
1676 	if (pmp->mp)
1677 		hammer2_unmount_helper(mp, pmp, NULL);
1678 
1679 	error = 0;
1680 failed:
1681 	lockmgr(&hammer2_mntlk, LK_RELEASE);
1682 
1683 	return (error);
1684 }
1685 
1686 /*
1687  * Mount helper, hook the system mount into our PFS.
1688  * The mount lock is held.
1689  *
1690  * We must bump the mount_count on related devices for any
1691  * mounted PFSs.
1692  */
1693 static
1694 void
1695 hammer2_mount_helper(struct mount *mp, hammer2_pfs_t *pmp)
1696 {
1697 	hammer2_cluster_t *cluster;
1698 	hammer2_chain_t *rchain;
1699 	int i;
1700 
1701 	mp->mnt_data = (qaddr_t)pmp;
1702 	pmp->mp = mp;
1703 
1704 	/*
1705 	 * After pmp->mp is set we have to adjust hmp->mount_count.
1706 	 */
1707 	cluster = &pmp->iroot->cluster;
1708 	for (i = 0; i < cluster->nchains; ++i) {
1709 		rchain = cluster->array[i].chain;
1710 		if (rchain == NULL)
1711 			continue;
1712 		++rchain->hmp->mount_count;
1713 	}
1714 
1715 	/*
1716 	 * Create missing Xop threads
1717 	 */
1718 	hammer2_xop_helper_create(pmp);
1719 }
1720 
1721 /*
1722  * Unmount helper, unhook the system mount from our PFS.
1723  * The mount lock is held.
1724  *
1725  * If hmp is supplied a mount responsible for being the first to open
1726  * the block device failed and the block device and all PFSs using the
1727  * block device must be cleaned up.
1728  *
1729  * If pmp is supplied multiple devices might be backing the PFS and each
1730  * must be disconnected.  This might not be the last PFS using some of the
1731  * underlying devices.  Also, we have to adjust our hmp->mount_count
1732  * accounting for the devices backing the pmp which is now undergoing an
1733  * unmount.
1734  */
1735 static
1736 void
1737 hammer2_unmount_helper(struct mount *mp, hammer2_pfs_t *pmp, hammer2_dev_t *hmp)
1738 {
1739 	hammer2_cluster_t *cluster;
1740 	hammer2_chain_t *rchain;
1741 	int dumpcnt;
1742 	int i;
1743 
1744 	/*
1745 	 * If no device supplied this is a high-level unmount and we have to
1746 	 * to disconnect the mount, adjust mount_count, and locate devices
1747 	 * that might now have no mounts.
1748 	 */
1749 	if (pmp) {
1750 		KKASSERT(hmp == NULL);
1751 		KKASSERT(MPTOPMP(mp) == pmp);
1752 		pmp->mp = NULL;
1753 		mp->mnt_data = NULL;
1754 
1755 		/*
1756 		 * After pmp->mp is cleared we have to account for
1757 		 * mount_count.
1758 		 */
1759 		cluster = &pmp->iroot->cluster;
1760 		for (i = 0; i < cluster->nchains; ++i) {
1761 			rchain = cluster->array[i].chain;
1762 			if (rchain == NULL)
1763 				continue;
1764 			--rchain->hmp->mount_count;
1765 			/* scrapping hmp now may invalidate the pmp */
1766 		}
1767 again:
1768 		TAILQ_FOREACH(hmp, &hammer2_mntlist, mntentry) {
1769 			if (hmp->mount_count == 0) {
1770 				hammer2_unmount_helper(NULL, NULL, hmp);
1771 				goto again;
1772 			}
1773 		}
1774 		return;
1775 	}
1776 
1777 	/*
1778 	 * Try to terminate the block device.  We can't terminate it if
1779 	 * there are still PFSs referencing it.
1780 	 */
1781 	if (hmp->mount_count)
1782 		return;
1783 
1784 	/*
1785 	 * Decomission the network before we start messing with the
1786 	 * device and PFS.
1787 	 */
1788 	hammer2_iocom_uninit(hmp);
1789 
1790 	hammer2_bulkfree_uninit(hmp);
1791 	hammer2_pfsfree_scan(hmp, 0);
1792 
1793 	/*
1794 	 * Cycle the volume data lock as a safety (probably not needed any
1795 	 * more).  To ensure everything is out we need to flush at least
1796 	 * three times.  (1) The running of the sideq can dirty the
1797 	 * filesystem, (2) A normal flush can dirty the freemap, and
1798 	 * (3) ensure that the freemap is fully synchronized.
1799 	 *
1800 	 * The next mount's recovery scan can clean everything up but we want
1801 	 * to leave the filesystem in a 100% clean state on a normal unmount.
1802 	 */
1803 #if 0
1804 	hammer2_voldata_lock(hmp);
1805 	hammer2_voldata_unlock(hmp);
1806 #endif
1807 
1808 	/*
1809 	 * Flush whatever is left.  Unmounted but modified PFS's might still
1810 	 * have some dirty chains on them.
1811 	 */
1812 	hammer2_chain_lock(&hmp->vchain, HAMMER2_RESOLVE_ALWAYS);
1813 	hammer2_chain_lock(&hmp->fchain, HAMMER2_RESOLVE_ALWAYS);
1814 
1815 	if (hmp->fchain.flags & HAMMER2_CHAIN_FLUSH_MASK) {
1816 		hammer2_voldata_modify(hmp);
1817 		hammer2_flush(&hmp->fchain, HAMMER2_FLUSH_TOP |
1818 					    HAMMER2_FLUSH_ALL);
1819 	}
1820 	hammer2_chain_unlock(&hmp->fchain);
1821 
1822 	if (hmp->vchain.flags & HAMMER2_CHAIN_FLUSH_MASK) {
1823 		hammer2_flush(&hmp->vchain, HAMMER2_FLUSH_TOP |
1824 					    HAMMER2_FLUSH_ALL);
1825 	}
1826 	hammer2_chain_unlock(&hmp->vchain);
1827 
1828 	if ((hmp->vchain.flags | hmp->fchain.flags) &
1829 	    HAMMER2_CHAIN_FLUSH_MASK) {
1830 		kprintf("hammer2_unmount: chains left over after final sync\n");
1831 		kprintf("    vchain %08x\n", hmp->vchain.flags);
1832 		kprintf("    fchain %08x\n", hmp->fchain.flags);
1833 
1834 		if (hammer2_debug & 0x0010)
1835 			Debugger("entered debugger");
1836 	}
1837 
1838 	hammer2_pfsfree_scan(hmp, 1);
1839 
1840 	KKASSERT(hmp->spmp == NULL);
1841 
1842 	/*
1843 	 * Finish up with the device vnode
1844 	 */
1845 	if (!TAILQ_EMPTY(&hmp->devvpl)) {
1846 		hammer2_close_devvp(&hmp->devvpl, hmp->ronly);
1847 		hammer2_cleanup_devvp(&hmp->devvpl);
1848 	}
1849 	KKASSERT(TAILQ_EMPTY(&hmp->devvpl));
1850 
1851 	/*
1852 	 * Clear vchain/fchain flags that might prevent final cleanup
1853 	 * of these chains.
1854 	 */
1855 	if (hmp->vchain.flags & HAMMER2_CHAIN_MODIFIED) {
1856 		atomic_add_long(&hammer2_count_modified_chains, -1);
1857 		atomic_clear_int(&hmp->vchain.flags, HAMMER2_CHAIN_MODIFIED);
1858 		hammer2_pfs_memory_wakeup(hmp->vchain.pmp, -1);
1859 	}
1860 	if (hmp->vchain.flags & HAMMER2_CHAIN_UPDATE) {
1861 		atomic_clear_int(&hmp->vchain.flags, HAMMER2_CHAIN_UPDATE);
1862 	}
1863 
1864 	if (hmp->fchain.flags & HAMMER2_CHAIN_MODIFIED) {
1865 		atomic_add_long(&hammer2_count_modified_chains, -1);
1866 		atomic_clear_int(&hmp->fchain.flags, HAMMER2_CHAIN_MODIFIED);
1867 		hammer2_pfs_memory_wakeup(hmp->fchain.pmp, -1);
1868 	}
1869 	if (hmp->fchain.flags & HAMMER2_CHAIN_UPDATE) {
1870 		atomic_clear_int(&hmp->fchain.flags, HAMMER2_CHAIN_UPDATE);
1871 	}
1872 
1873 	dumpcnt = 50;
1874 	hammer2_dump_chain(&hmp->vchain, 0, 0, &dumpcnt, 'v', (u_int)-1);
1875 	dumpcnt = 50;
1876 	hammer2_dump_chain(&hmp->fchain, 0, 0, &dumpcnt, 'f', (u_int)-1);
1877 
1878 	/*
1879 	 * Final drop of embedded freemap root chain to
1880 	 * clean up fchain.core (fchain structure is not
1881 	 * flagged ALLOCATED so it is cleaned out and then
1882 	 * left to rot).
1883 	 */
1884 	hammer2_chain_drop(&hmp->fchain);
1885 
1886 	/*
1887 	 * Final drop of embedded volume root chain to clean
1888 	 * up vchain.core (vchain structure is not flagged
1889 	 * ALLOCATED so it is cleaned out and then left to
1890 	 * rot).
1891 	 */
1892 	hammer2_chain_drop(&hmp->vchain);
1893 
1894 	hammer2_io_cleanup(hmp, &hmp->iotree);
1895 	if (hmp->iofree_count) {
1896 		kprintf("io_cleanup: %d I/O's left hanging\n",
1897 			hmp->iofree_count);
1898 	}
1899 
1900 	TAILQ_REMOVE(&hammer2_mntlist, hmp, mntentry);
1901 	kmalloc_destroy_obj(&hmp->mchain);
1902 	kmalloc_destroy_obj(&hmp->mio);
1903 	kmalloc_destroy(&hmp->mmsg);
1904 	kfree(hmp, M_HAMMER2);
1905 }
1906 
1907 int
1908 hammer2_vfs_vget(struct mount *mp, struct vnode *dvp,
1909 		 ino_t ino, struct vnode **vpp)
1910 {
1911 	hammer2_xop_lookup_t *xop;
1912 	hammer2_pfs_t *pmp;
1913 	hammer2_inode_t *ip;
1914 	hammer2_tid_t inum;
1915 	int error;
1916 
1917 	inum = (hammer2_tid_t)ino & HAMMER2_DIRHASH_USERMSK;
1918 
1919 	error = 0;
1920 	pmp = MPTOPMP(mp);
1921 
1922 	/*
1923 	 * Easy if we already have it cached
1924 	 */
1925 	ip = hammer2_inode_lookup(pmp, inum);
1926 	if (ip) {
1927 		hammer2_inode_lock(ip, HAMMER2_RESOLVE_SHARED);
1928 		*vpp = hammer2_igetv(ip, &error);
1929 		hammer2_inode_unlock(ip);
1930 		hammer2_inode_drop(ip);		/* from lookup */
1931 
1932 		return error;
1933 	}
1934 
1935 	/*
1936 	 * Otherwise we have to find the inode
1937 	 */
1938 	xop = hammer2_xop_alloc(pmp->iroot, 0);
1939 	xop->lhc = inum;
1940 	hammer2_xop_start(&xop->head, &hammer2_lookup_desc);
1941 	error = hammer2_xop_collect(&xop->head, 0);
1942 
1943 	if (error == 0)
1944 		ip = hammer2_inode_get(pmp, &xop->head, -1, -1);
1945 	hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
1946 
1947 	if (ip) {
1948 		*vpp = hammer2_igetv(ip, &error);
1949 		hammer2_inode_unlock(ip);
1950 	} else {
1951 		*vpp = NULL;
1952 		error = ENOENT;
1953 	}
1954 	return (error);
1955 }
1956 
1957 static
1958 int
1959 hammer2_vfs_root(struct mount *mp, struct vnode **vpp)
1960 {
1961 	hammer2_pfs_t *pmp;
1962 	struct vnode *vp;
1963 	int error;
1964 
1965 	pmp = MPTOPMP(mp);
1966 	if (pmp->iroot == NULL) {
1967 		kprintf("hammer2 (%s): no root inode\n",
1968 			mp->mnt_stat.f_mntfromname);
1969 		*vpp = NULL;
1970 		return EINVAL;
1971 	}
1972 
1973 	error = 0;
1974 	hammer2_inode_lock(pmp->iroot, HAMMER2_RESOLVE_SHARED);
1975 
1976 	while (pmp->inode_tid == 0) {
1977 		hammer2_xop_ipcluster_t *xop;
1978 		const hammer2_inode_meta_t *meta;
1979 
1980 		xop = hammer2_xop_alloc(pmp->iroot, HAMMER2_XOP_MODIFYING);
1981 		hammer2_xop_start(&xop->head, &hammer2_ipcluster_desc);
1982 		error = hammer2_xop_collect(&xop->head, 0);
1983 
1984 		if (error == 0) {
1985 			meta = &hammer2_xop_gdata(&xop->head)->ipdata.meta;
1986 			pmp->iroot->meta = *meta;
1987 			pmp->inode_tid = meta->pfs_inum + 1;
1988 			hammer2_xop_pdata(&xop->head);
1989 			/* meta invalid */
1990 
1991 			if (pmp->inode_tid < HAMMER2_INODE_START)
1992 				pmp->inode_tid = HAMMER2_INODE_START;
1993 			pmp->modify_tid =
1994 				xop->head.cluster.focus->bref.modify_tid + 1;
1995 #if 0
1996 			kprintf("PFS: Starting inode %jd\n",
1997 				(intmax_t)pmp->inode_tid);
1998 			kprintf("PMP focus good set nextino=%ld mod=%016jx\n",
1999 				pmp->inode_tid, pmp->modify_tid);
2000 #endif
2001 			wakeup(&pmp->iroot);
2002 
2003 			hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
2004 
2005 			/*
2006 			 * Prime the mount info.
2007 			 */
2008 			hammer2_vfs_statfs(mp, &mp->mnt_stat, NULL);
2009 			break;
2010 		}
2011 
2012 		/*
2013 		 * Loop, try again
2014 		 */
2015 		hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
2016 		hammer2_inode_unlock(pmp->iroot);
2017 		error = tsleep(&pmp->iroot, PCATCH, "h2root", hz);
2018 		hammer2_inode_lock(pmp->iroot, HAMMER2_RESOLVE_SHARED);
2019 		if (error == EINTR)
2020 			break;
2021 	}
2022 
2023 	if (error) {
2024 		hammer2_inode_unlock(pmp->iroot);
2025 		*vpp = NULL;
2026 	} else {
2027 		vp = hammer2_igetv(pmp->iroot, &error);
2028 		hammer2_inode_unlock(pmp->iroot);
2029 		*vpp = vp;
2030 	}
2031 
2032 	return (error);
2033 }
2034 
2035 /*
2036  * Filesystem status
2037  *
2038  * XXX incorporate ipdata->meta.inode_quota and data_quota
2039  */
2040 static
2041 int
2042 hammer2_vfs_statfs(struct mount *mp, struct statfs *sbp, struct ucred *cred)
2043 {
2044 	hammer2_pfs_t *pmp;
2045 	hammer2_dev_t *hmp;
2046 	hammer2_blockref_t bref;
2047 	struct statfs tmp;
2048 	int i;
2049 
2050 	/*
2051 	 * NOTE: iroot might not have validated the cluster yet.
2052 	 */
2053 	pmp = MPTOPMP(mp);
2054 
2055 	bzero(&tmp, sizeof(tmp));
2056 
2057 	for (i = 0; i < pmp->iroot->cluster.nchains; ++i) {
2058 		hmp = pmp->pfs_hmps[i];
2059 		if (hmp == NULL)
2060 			continue;
2061 		if (pmp->iroot->cluster.array[i].chain)
2062 			bref = pmp->iroot->cluster.array[i].chain->bref;
2063 		else
2064 			bzero(&bref, sizeof(bref));
2065 
2066 		tmp.f_files = bref.embed.stats.inode_count;
2067 		tmp.f_ffree = 0;
2068 		tmp.f_blocks = hmp->voldata.allocator_size /
2069 			       mp->mnt_vstat.f_bsize;
2070 		tmp.f_bfree = hmp->voldata.allocator_free /
2071 			      mp->mnt_vstat.f_bsize;
2072 		tmp.f_bavail = tmp.f_bfree;
2073 
2074 		if (cred && cred->cr_uid != 0) {
2075 			uint64_t adj;
2076 
2077 			/* 5% */
2078 			adj = hmp->free_reserved / mp->mnt_vstat.f_bsize;
2079 			tmp.f_blocks -= adj;
2080 			tmp.f_bfree -= adj;
2081 			tmp.f_bavail -= adj;
2082 		}
2083 
2084 		mp->mnt_stat.f_blocks = tmp.f_blocks;
2085 		mp->mnt_stat.f_bfree = tmp.f_bfree;
2086 		mp->mnt_stat.f_bavail = tmp.f_bavail;
2087 		mp->mnt_stat.f_files = tmp.f_files;
2088 		mp->mnt_stat.f_ffree = tmp.f_ffree;
2089 
2090 		*sbp = mp->mnt_stat;
2091 	}
2092 	return (0);
2093 }
2094 
2095 static
2096 int
2097 hammer2_vfs_statvfs(struct mount *mp, struct statvfs *sbp, struct ucred *cred)
2098 {
2099 	hammer2_pfs_t *pmp;
2100 	hammer2_dev_t *hmp;
2101 	hammer2_blockref_t bref;
2102 	struct statvfs tmp;
2103 	int i;
2104 
2105 	/*
2106 	 * NOTE: iroot might not have validated the cluster yet.
2107 	 */
2108 	pmp = MPTOPMP(mp);
2109 	bzero(&tmp, sizeof(tmp));
2110 
2111 	for (i = 0; i < pmp->iroot->cluster.nchains; ++i) {
2112 		hmp = pmp->pfs_hmps[i];
2113 		if (hmp == NULL)
2114 			continue;
2115 		if (pmp->iroot->cluster.array[i].chain)
2116 			bref = pmp->iroot->cluster.array[i].chain->bref;
2117 		else
2118 			bzero(&bref, sizeof(bref));
2119 
2120 		tmp.f_files = bref.embed.stats.inode_count;
2121 		tmp.f_ffree = 0;
2122 		tmp.f_blocks = hmp->voldata.allocator_size /
2123 			       mp->mnt_vstat.f_bsize;
2124 		tmp.f_bfree = hmp->voldata.allocator_free /
2125 			      mp->mnt_vstat.f_bsize;
2126 		tmp.f_bavail = tmp.f_bfree;
2127 
2128 		if (cred && cred->cr_uid != 0) {
2129 			uint64_t adj;
2130 
2131 			/* 5% */
2132 			adj = hmp->free_reserved / mp->mnt_vstat.f_bsize;
2133 			tmp.f_blocks -= adj;
2134 			tmp.f_bfree -= adj;
2135 			tmp.f_bavail -= adj;
2136 		}
2137 
2138 		mp->mnt_vstat.f_blocks = tmp.f_blocks;
2139 		mp->mnt_vstat.f_bfree = tmp.f_bfree;
2140 		mp->mnt_vstat.f_bavail = tmp.f_bavail;
2141 		mp->mnt_vstat.f_files = tmp.f_files;
2142 		mp->mnt_vstat.f_ffree = tmp.f_ffree;
2143 
2144 		*sbp = mp->mnt_vstat;
2145 	}
2146 	return (0);
2147 }
2148 
2149 /*
2150  * Mount-time recovery (RW mounts)
2151  *
2152  * Updates to the free block table are allowed to lag flushes by one
2153  * transaction.  In case of a crash, then on a fresh mount we must do an
2154  * incremental scan of the last committed transaction id and make sure that
2155  * all related blocks have been marked allocated.
2156  */
2157 struct hammer2_recovery_elm {
2158 	TAILQ_ENTRY(hammer2_recovery_elm) entry;
2159 	hammer2_chain_t *chain;
2160 	hammer2_tid_t sync_tid;
2161 };
2162 
2163 TAILQ_HEAD(hammer2_recovery_list, hammer2_recovery_elm);
2164 
2165 struct hammer2_recovery_info {
2166 	struct hammer2_recovery_list list;
2167 	hammer2_tid_t	mtid;
2168 	int	depth;
2169 };
2170 
2171 static int hammer2_recovery_scan(hammer2_dev_t *hmp,
2172 			hammer2_chain_t *parent,
2173 			struct hammer2_recovery_info *info,
2174 			hammer2_tid_t sync_tid);
2175 
2176 #define HAMMER2_RECOVERY_MAXDEPTH	10
2177 
2178 static
2179 int
2180 hammer2_recovery(hammer2_dev_t *hmp)
2181 {
2182 	struct hammer2_recovery_info info;
2183 	struct hammer2_recovery_elm *elm;
2184 	hammer2_chain_t *parent;
2185 	hammer2_tid_t sync_tid;
2186 	hammer2_tid_t mirror_tid;
2187 	int error;
2188 
2189 	hammer2_trans_init(hmp->spmp, 0);
2190 
2191 	sync_tid = hmp->voldata.freemap_tid;
2192 	mirror_tid = hmp->voldata.mirror_tid;
2193 
2194 	kprintf("hammer2_mount: \"%s\": ", hmp->devrepname);
2195 	if (sync_tid >= mirror_tid) {
2196 		kprintf("no recovery needed\n");
2197 	} else {
2198 		kprintf("freemap recovery %016jx-%016jx\n",
2199 			sync_tid + 1, mirror_tid);
2200 	}
2201 
2202 	TAILQ_INIT(&info.list);
2203 	info.depth = 0;
2204 	parent = hammer2_chain_lookup_init(&hmp->vchain, 0);
2205 	error = hammer2_recovery_scan(hmp, parent, &info, sync_tid);
2206 	hammer2_chain_lookup_done(parent);
2207 
2208 	while ((elm = TAILQ_FIRST(&info.list)) != NULL) {
2209 		TAILQ_REMOVE(&info.list, elm, entry);
2210 		parent = elm->chain;
2211 		sync_tid = elm->sync_tid;
2212 		kfree(elm, M_HAMMER2);
2213 
2214 		hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS);
2215 		error |= hammer2_recovery_scan(hmp, parent, &info,
2216 					      hmp->voldata.freemap_tid);
2217 		hammer2_chain_unlock(parent);
2218 		hammer2_chain_drop(parent);	/* drop elm->chain ref */
2219 	}
2220 
2221 	hammer2_trans_done(hmp->spmp, 0);
2222 
2223 	return error;
2224 }
2225 
2226 static
2227 int
2228 hammer2_recovery_scan(hammer2_dev_t *hmp, hammer2_chain_t *parent,
2229 		      struct hammer2_recovery_info *info,
2230 		      hammer2_tid_t sync_tid)
2231 {
2232 	const hammer2_inode_data_t *ripdata;
2233 	hammer2_chain_t *chain;
2234 	hammer2_blockref_t bref;
2235 	int tmp_error;
2236 	int rup_error;
2237 	int error;
2238 	int first;
2239 
2240 	/*
2241 	 * Adjust freemap to ensure that the block(s) are marked allocated.
2242 	 */
2243 	if (parent->bref.type != HAMMER2_BREF_TYPE_VOLUME) {
2244 		hammer2_freemap_adjust(hmp, &parent->bref,
2245 				       HAMMER2_FREEMAP_DORECOVER);
2246 	}
2247 
2248 	/*
2249 	 * Check type for recursive scan
2250 	 */
2251 	switch(parent->bref.type) {
2252 	case HAMMER2_BREF_TYPE_VOLUME:
2253 		/* data already instantiated */
2254 		break;
2255 	case HAMMER2_BREF_TYPE_INODE:
2256 		/*
2257 		 * Must instantiate data for DIRECTDATA test and also
2258 		 * for recursion.
2259 		 */
2260 		hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS);
2261 		ripdata = &parent->data->ipdata;
2262 		if (ripdata->meta.op_flags & HAMMER2_OPFLAG_DIRECTDATA) {
2263 			/* not applicable to recovery scan */
2264 			hammer2_chain_unlock(parent);
2265 			return 0;
2266 		}
2267 		hammer2_chain_unlock(parent);
2268 		break;
2269 	case HAMMER2_BREF_TYPE_INDIRECT:
2270 		/*
2271 		 * Must instantiate data for recursion
2272 		 */
2273 		hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS);
2274 		hammer2_chain_unlock(parent);
2275 		break;
2276 	case HAMMER2_BREF_TYPE_DIRENT:
2277 	case HAMMER2_BREF_TYPE_DATA:
2278 	case HAMMER2_BREF_TYPE_FREEMAP:
2279 	case HAMMER2_BREF_TYPE_FREEMAP_NODE:
2280 	case HAMMER2_BREF_TYPE_FREEMAP_LEAF:
2281 		/* not applicable to recovery scan */
2282 		return 0;
2283 		break;
2284 	default:
2285 		return HAMMER2_ERROR_BADBREF;
2286 	}
2287 
2288 	/*
2289 	 * Defer operation if depth limit reached.
2290 	 */
2291 	if (info->depth >= HAMMER2_RECOVERY_MAXDEPTH) {
2292 		struct hammer2_recovery_elm *elm;
2293 
2294 		elm = kmalloc(sizeof(*elm), M_HAMMER2, M_ZERO | M_WAITOK);
2295 		elm->chain = parent;
2296 		elm->sync_tid = sync_tid;
2297 		hammer2_chain_ref(parent);
2298 		TAILQ_INSERT_TAIL(&info->list, elm, entry);
2299 		/* unlocked by caller */
2300 
2301 		return(0);
2302 	}
2303 
2304 
2305 	/*
2306 	 * Recursive scan of the last flushed transaction only.  We are
2307 	 * doing this without pmp assignments so don't leave the chains
2308 	 * hanging around after we are done with them.
2309 	 *
2310 	 * error	Cumulative error this level only
2311 	 * rup_error	Cumulative error for recursion
2312 	 * tmp_error	Specific non-cumulative recursion error
2313 	 */
2314 	chain = NULL;
2315 	first = 1;
2316 	rup_error = 0;
2317 	error = 0;
2318 
2319 	for (;;) {
2320 		error |= hammer2_chain_scan(parent, &chain, &bref,
2321 					    &first,
2322 					    HAMMER2_LOOKUP_NODATA);
2323 
2324 		/*
2325 		 * Problem during scan or EOF
2326 		 */
2327 		if (error)
2328 			break;
2329 
2330 		/*
2331 		 * If this is a leaf
2332 		 */
2333 		if (chain == NULL) {
2334 			if (bref.mirror_tid > sync_tid) {
2335 				hammer2_freemap_adjust(hmp, &bref,
2336 						     HAMMER2_FREEMAP_DORECOVER);
2337 			}
2338 			continue;
2339 		}
2340 
2341 		/*
2342 		 * This may or may not be a recursive node.
2343 		 */
2344 		atomic_set_int(&chain->flags, HAMMER2_CHAIN_RELEASE);
2345 		if (bref.mirror_tid > sync_tid) {
2346 			++info->depth;
2347 			tmp_error = hammer2_recovery_scan(hmp, chain,
2348 							   info, sync_tid);
2349 			--info->depth;
2350 		} else {
2351 			tmp_error = 0;
2352 		}
2353 
2354 		/*
2355 		 * Flush the recovery at the PFS boundary to stage it for
2356 		 * the final flush of the super-root topology.
2357 		 */
2358 		if (tmp_error == 0 &&
2359 		    (bref.flags & HAMMER2_BREF_FLAG_PFSROOT) &&
2360 		    (chain->flags & HAMMER2_CHAIN_ONFLUSH)) {
2361 			hammer2_flush(chain, HAMMER2_FLUSH_TOP |
2362 					     HAMMER2_FLUSH_ALL);
2363 		}
2364 		rup_error |= tmp_error;
2365 	}
2366 	return ((error | rup_error) & ~HAMMER2_ERROR_EOF);
2367 }
2368 
2369 /*
2370  * This fixes up an error introduced in earlier H2 implementations where
2371  * moving a PFS inode into an indirect block wound up causing the
2372  * HAMMER2_BREF_FLAG_PFSROOT flag in the bref to get cleared.
2373  */
2374 static
2375 int
2376 hammer2_fixup_pfses(hammer2_dev_t *hmp)
2377 {
2378 	const hammer2_inode_data_t *ripdata;
2379 	hammer2_chain_t *parent;
2380 	hammer2_chain_t *chain;
2381 	hammer2_key_t key_next;
2382 	hammer2_pfs_t *spmp;
2383 	int error;
2384 
2385 	error = 0;
2386 
2387 	/*
2388 	 * Lookup mount point under the media-localized super-root.
2389 	 *
2390 	 * cluster->pmp will incorrectly point to spmp and must be fixed
2391 	 * up later on.
2392 	 */
2393 	spmp = hmp->spmp;
2394 	hammer2_inode_lock(spmp->iroot, 0);
2395 	parent = hammer2_inode_chain(spmp->iroot, 0, HAMMER2_RESOLVE_ALWAYS);
2396 	chain = hammer2_chain_lookup(&parent, &key_next,
2397 					 HAMMER2_KEY_MIN, HAMMER2_KEY_MAX,
2398 					 &error, 0);
2399 	while (chain) {
2400 		if (chain->bref.type != HAMMER2_BREF_TYPE_INODE)
2401 			continue;
2402 		if (chain->error) {
2403 			kprintf("I/O error scanning PFS labels\n");
2404 			error |= chain->error;
2405 		} else if ((chain->bref.flags &
2406 			    HAMMER2_BREF_FLAG_PFSROOT) == 0) {
2407 			int error2;
2408 
2409 			ripdata = &chain->data->ipdata;
2410 			hammer2_trans_init(hmp->spmp, 0);
2411 			error2 = hammer2_chain_modify(chain,
2412 						      chain->bref.modify_tid,
2413 						      0, 0);
2414 			if (error2 == 0) {
2415 				kprintf("hammer2: Correct mis-flagged PFS %s\n",
2416 					ripdata->filename);
2417 				chain->bref.flags |= HAMMER2_BREF_FLAG_PFSROOT;
2418 			} else {
2419 				error |= error2;
2420 			}
2421 			hammer2_flush(chain, HAMMER2_FLUSH_TOP |
2422 					     HAMMER2_FLUSH_ALL);
2423 			hammer2_trans_done(hmp->spmp, 0);
2424 		}
2425 		chain = hammer2_chain_next(&parent, chain, &key_next,
2426 					   key_next, HAMMER2_KEY_MAX,
2427 					   &error, 0);
2428 	}
2429 	if (parent) {
2430 		hammer2_chain_unlock(parent);
2431 		hammer2_chain_drop(parent);
2432 	}
2433 	hammer2_inode_unlock(spmp->iroot);
2434 
2435 	return error;
2436 }
2437 
2438 /*
2439  * Sync a mount point; this is called periodically on a per-mount basis from
2440  * the filesystem syncer, and whenever a user issues a sync.
2441  */
2442 int
2443 hammer2_vfs_sync(struct mount *mp, int waitfor)
2444 {
2445 	int error;
2446 
2447 	error = hammer2_vfs_sync_pmp(MPTOPMP(mp), waitfor);
2448 
2449 	return error;
2450 }
2451 
2452 /*
2453  * Because frontend operations lock vnodes before we get a chance to
2454  * lock the related inode, we can't just acquire a vnode lock without
2455  * risking a deadlock.  The frontend may be holding a vnode lock while
2456  * also blocked on our SYNCQ flag while trying to get the inode lock.
2457  *
2458  * To deal with this situation we can check the vnode lock situation
2459  * after locking the inode and perform a work-around.
2460  */
2461 int
2462 hammer2_vfs_sync_pmp(hammer2_pfs_t *pmp, int waitfor)
2463 {
2464 	hammer2_inode_t *ip;
2465 	hammer2_depend_t *depend;
2466 	hammer2_depend_t *depend_next;
2467 	struct vnode *vp;
2468 	uint32_t pass2;
2469 	int error;
2470 	int wakecount;
2471 	int dorestart;
2472 
2473 	/*
2474 	 * Move all inodes on sideq to syncq.  This will clear sideq.
2475 	 * This should represent all flushable inodes.  These inodes
2476 	 * will already have refs due to being on syncq or sideq.  We
2477 	 * must do this all at once with the spinlock held to ensure that
2478 	 * all inode dependencies are part of the same flush.
2479 	 *
2480 	 * We should be able to do this asynchronously from frontend
2481 	 * operations because we will be locking the inodes later on
2482 	 * to actually flush them, and that will partition any frontend
2483 	 * op using the same inode.  Either it has already locked the
2484 	 * inode and we will block, or it has not yet locked the inode
2485 	 * and it will block until we are finished flushing that inode.
2486 	 *
2487 	 * When restarting, only move the inodes flagged as PASS2 from
2488 	 * SIDEQ to SYNCQ.  PASS2 propagation by inode_lock4() and
2489 	 * inode_depend() are atomic with the spin-lock.
2490 	 */
2491 	hammer2_trans_init(pmp, HAMMER2_TRANS_ISFLUSH);
2492 #ifdef HAMMER2_DEBUG_SYNC
2493 	kprintf("FILESYSTEM SYNC BOUNDARY\n");
2494 #endif
2495 	dorestart = 0;
2496 
2497 	/*
2498 	 * Move inodes from depq to syncq, releasing the related
2499 	 * depend structures.
2500 	 */
2501 restart:
2502 #ifdef HAMMER2_DEBUG_SYNC
2503 	kprintf("FILESYSTEM SYNC RESTART (%d)\n", dorestart);
2504 #endif
2505 	hammer2_trans_setflags(pmp, 0/*HAMMER2_TRANS_COPYQ*/);
2506 	hammer2_trans_clearflags(pmp, HAMMER2_TRANS_RESCAN);
2507 
2508 	/*
2509 	 * Move inodes from depq to syncq.  When restarting, only depq's
2510 	 * marked pass2 are moved.
2511 	 */
2512 	hammer2_spin_ex(&pmp->list_spin);
2513 	depend_next = TAILQ_FIRST(&pmp->depq);
2514 	wakecount = 0;
2515 
2516 	while ((depend = depend_next) != NULL) {
2517 		depend_next = TAILQ_NEXT(depend, entry);
2518 		if (dorestart && depend->pass2 == 0)
2519 			continue;
2520 		TAILQ_FOREACH(ip, &depend->sideq, entry) {
2521 			KKASSERT(ip->flags & HAMMER2_INODE_SIDEQ);
2522 			atomic_set_int(&ip->flags, HAMMER2_INODE_SYNCQ);
2523 			atomic_clear_int(&ip->flags, HAMMER2_INODE_SIDEQ);
2524 			ip->depend = NULL;
2525 		}
2526 
2527 		/*
2528 		 * NOTE: pmp->sideq_count includes both sideq and syncq
2529 		 */
2530 		TAILQ_CONCAT(&pmp->syncq, &depend->sideq, entry);
2531 
2532 		depend->count = 0;
2533 		depend->pass2 = 0;
2534 		TAILQ_REMOVE(&pmp->depq, depend, entry);
2535 	}
2536 
2537 	hammer2_spin_unex(&pmp->list_spin);
2538 	hammer2_trans_clearflags(pmp, /*HAMMER2_TRANS_COPYQ |*/
2539 				      HAMMER2_TRANS_WAITING);
2540 	dorestart = 0;
2541 
2542 	/*
2543 	 * sideq_count may have dropped enough to allow us to unstall
2544 	 * the frontend.
2545 	 */
2546 	hammer2_pfs_memory_wakeup(pmp, 0);
2547 
2548 	/*
2549 	 * Now run through all inodes on syncq.
2550 	 *
2551 	 * Flush transactions only interlock with other flush transactions.
2552 	 * Any conflicting frontend operations will block on the inode, but
2553 	 * may hold a vnode lock while doing so.
2554 	 */
2555 	hammer2_spin_ex(&pmp->list_spin);
2556 	while ((ip = TAILQ_FIRST(&pmp->syncq)) != NULL) {
2557 		/*
2558 		 * Remove the inode from the SYNCQ, transfer the syncq ref
2559 		 * to us.  We must clear SYNCQ to allow any potential
2560 		 * front-end deadlock to proceed.  We must set PASS2 so
2561 		 * the dependency code knows what to do.
2562 		 */
2563 		pass2 = ip->flags;
2564 		cpu_ccfence();
2565 		if (atomic_cmpset_int(&ip->flags,
2566 			      pass2,
2567 			      (pass2 & ~(HAMMER2_INODE_SYNCQ |
2568 					 HAMMER2_INODE_SYNCQ_WAKEUP)) |
2569 			      HAMMER2_INODE_SYNCQ_PASS2) == 0)
2570 		{
2571 			continue;
2572 		}
2573 		TAILQ_REMOVE(&pmp->syncq, ip, entry);
2574 		--pmp->sideq_count;
2575 		hammer2_spin_unex(&pmp->list_spin);
2576 
2577 		/*
2578 		 * Tickle anyone waiting on ip->flags or the hysteresis
2579 		 * on the dirty inode count.
2580 		 */
2581 		if (pass2 & HAMMER2_INODE_SYNCQ_WAKEUP)
2582 			wakeup(&ip->flags);
2583 		if (++wakecount >= hammer2_limit_dirty_inodes / 20 + 1) {
2584 			wakecount = 0;
2585 			hammer2_pfs_memory_wakeup(pmp, 0);
2586 		}
2587 
2588 		/*
2589 		 * Relock the inode, and we inherit a ref from the above.
2590 		 * We will check for a race after we acquire the vnode.
2591 		 */
2592 		hammer2_mtx_ex(&ip->lock);
2593 
2594 		/*
2595 		 * We need the vp in order to vfsync() dirty buffers, so if
2596 		 * one isn't attached we can skip it.
2597 		 *
2598 		 * Ordering the inode lock and then the vnode lock has the
2599 		 * potential to deadlock.  If we had left SYNCQ set that could
2600 		 * also deadlock us against the frontend even if we don't hold
2601 		 * any locks, but the latter is not a problem now since we
2602 		 * cleared it.  igetv will temporarily release the inode lock
2603 		 * in a safe manner to work-around the deadlock.
2604 		 *
2605 		 * Unfortunately it is still possible to deadlock when the
2606 		 * frontend obtains multiple inode locks, because all the
2607 		 * related vnodes are already locked (nor can the vnode locks
2608 		 * be released and reacquired without messing up RECLAIM and
2609 		 * INACTIVE sequencing).
2610 		 *
2611 		 * The solution for now is to move the vp back onto SIDEQ
2612 		 * and set dorestart, which will restart the flush after we
2613 		 * exhaust the current SYNCQ.  Note that additional
2614 		 * dependencies may build up, so we definitely need to move
2615 		 * the whole SIDEQ back to SYNCQ when we restart.
2616 		 */
2617 		vp = ip->vp;
2618 		if (vp) {
2619 			if (vget(vp, LK_EXCLUSIVE|LK_NOWAIT)) {
2620 				/*
2621 				 * Failed to get the vnode, requeue the inode
2622 				 * (PASS2 is already set so it will be found
2623 				 * again on the restart).
2624 				 *
2625 				 * Then unlock, possibly sleep, and retry
2626 				 * later.  We sleep if PASS2 was *previously*
2627 				 * set, before we set it again above.
2628 				 */
2629 				vp = NULL;
2630 				dorestart = 1;
2631 #ifdef HAMMER2_DEBUG_SYNC
2632 				kprintf("inum %ld (sync delayed by vnode)\n",
2633 					(long)ip->meta.inum);
2634 #endif
2635 				hammer2_inode_delayed_sideq(ip);
2636 
2637 				hammer2_mtx_unlock(&ip->lock);
2638 				hammer2_inode_drop(ip);
2639 
2640 				if (pass2 & HAMMER2_INODE_SYNCQ_PASS2) {
2641 					tsleep(&dorestart, 0, "h2syndel", 2);
2642 				}
2643 				hammer2_spin_ex(&pmp->list_spin);
2644 				continue;
2645 			}
2646 		} else {
2647 			vp = NULL;
2648 		}
2649 
2650 		/*
2651 		 * If the inode wound up on a SIDEQ again it will already be
2652 		 * prepped for another PASS2.  In this situation if we flush
2653 		 * it now we will just wind up flushing it again in the same
2654 		 * syncer run, so we might as well not flush it now.
2655 		 */
2656 		if (ip->flags & HAMMER2_INODE_SIDEQ) {
2657 			hammer2_mtx_unlock(&ip->lock);
2658 			hammer2_inode_drop(ip);
2659 			if (vp)
2660 				vput(vp);
2661 			dorestart = 1;
2662 			hammer2_spin_ex(&pmp->list_spin);
2663 			continue;
2664 		}
2665 
2666 		/*
2667 		 * Ok we have the inode exclusively locked and if vp is
2668 		 * not NULL that will also be exclusively locked.  Do the
2669 		 * meat of the flush.
2670 		 *
2671 		 * vp token needed for v_rbdirty_tree check / vclrisdirty
2672 		 * sequencing.  Though we hold the vnode exclusively so
2673 		 * we shouldn't need to hold the token also in this case.
2674 		 */
2675 		if (vp) {
2676 			vfsync(vp, MNT_WAIT, 1, NULL, NULL);
2677 			bio_track_wait(&vp->v_track_write, 0, 0); /* XXX */
2678 		}
2679 
2680 		/*
2681 		 * If the inode has not yet been inserted into the tree
2682 		 * we must do so.  Then sync and flush it.  The flush should
2683 		 * update the parent.
2684 		 */
2685 		if (ip->flags & HAMMER2_INODE_DELETING) {
2686 #ifdef HAMMER2_DEBUG_SYNC
2687 			kprintf("inum %ld destroy\n", (long)ip->meta.inum);
2688 #endif
2689 			hammer2_inode_chain_des(ip);
2690 			atomic_add_long(&hammer2_iod_inode_deletes, 1);
2691 		} else if (ip->flags & HAMMER2_INODE_CREATING) {
2692 #ifdef HAMMER2_DEBUG_SYNC
2693 			kprintf("inum %ld insert\n", (long)ip->meta.inum);
2694 #endif
2695 			hammer2_inode_chain_ins(ip);
2696 			atomic_add_long(&hammer2_iod_inode_creates, 1);
2697 		}
2698 #ifdef HAMMER2_DEBUG_SYNC
2699 		kprintf("inum %ld chain-sync\n", (long)ip->meta.inum);
2700 #endif
2701 
2702 		/*
2703 		 * Because I kinda messed up the design and index the inodes
2704 		 * under the root inode, along side the directory entries,
2705 		 * we can't flush the inode index under the iroot until the
2706 		 * end.  If we do it now we might miss effects created by
2707 		 * other inodes on the SYNCQ.
2708 		 *
2709 		 * Do a normal (non-FSSYNC) flush instead, which allows the
2710 		 * vnode code to work the same.  We don't want to force iroot
2711 		 * back onto the SIDEQ, and we also don't want the flush code
2712 		 * to update pfs_iroot_blocksets until the final flush later.
2713 		 *
2714 		 * XXX at the moment this will likely result in a double-flush
2715 		 * of the iroot chain.
2716 		 */
2717 		hammer2_inode_chain_sync(ip);
2718 		if (ip == pmp->iroot) {
2719 			hammer2_inode_chain_flush(ip, HAMMER2_XOP_INODE_STOP);
2720 		} else {
2721 			hammer2_inode_chain_flush(ip, HAMMER2_XOP_INODE_STOP |
2722 						      HAMMER2_XOP_FSSYNC);
2723 		}
2724 		if (vp) {
2725 			lwkt_gettoken(&vp->v_token);
2726 			if ((ip->flags & (HAMMER2_INODE_MODIFIED |
2727 					  HAMMER2_INODE_RESIZED |
2728 					  HAMMER2_INODE_DIRTYDATA)) == 0 &&
2729 			    RB_EMPTY(&vp->v_rbdirty_tree) &&
2730 			    !bio_track_active(&vp->v_track_write)) {
2731 				vclrisdirty(vp);
2732 			} else {
2733 				hammer2_inode_delayed_sideq(ip);
2734 			}
2735 			lwkt_reltoken(&vp->v_token);
2736 			vput(vp);
2737 			vp = NULL;	/* safety */
2738 		}
2739 		atomic_clear_int(&ip->flags, HAMMER2_INODE_SYNCQ_PASS2);
2740 		hammer2_inode_unlock(ip);	/* unlock+drop */
2741 		/* ip pointer invalid */
2742 
2743 		/*
2744 		 * If the inode got dirted after we dropped our locks,
2745 		 * it will have already been moved back to the SIDEQ.
2746 		 */
2747 		hammer2_spin_ex(&pmp->list_spin);
2748 	}
2749 	hammer2_spin_unex(&pmp->list_spin);
2750 	hammer2_pfs_memory_wakeup(pmp, 0);
2751 
2752 	if (dorestart || (pmp->trans.flags & HAMMER2_TRANS_RESCAN)) {
2753 #ifdef HAMMER2_DEBUG_SYNC
2754 		kprintf("FILESYSTEM SYNC STAGE 1 RESTART\n");
2755 		/*tsleep(&dorestart, 0, "h2STG1-R", hz*20);*/
2756 #endif
2757 		dorestart = 1;
2758 		goto restart;
2759 	}
2760 #ifdef HAMMER2_DEBUG_SYNC
2761 	kprintf("FILESYSTEM SYNC STAGE 2 BEGIN\n");
2762 	/*tsleep(&dorestart, 0, "h2STG2", hz*20);*/
2763 #endif
2764 
2765 	/*
2766 	 * We have to flush the PFS root last, even if it does not appear to
2767 	 * be dirty, because all the inodes in the PFS are indexed under it.
2768 	 * The normal flushing of iroot above would only occur if directory
2769 	 * entries under the root were changed.
2770 	 *
2771 	 * Specifying VOLHDR will cause an additionl flush of hmp->spmp
2772 	 * for the media making up the cluster.
2773 	 */
2774 	if ((ip = pmp->iroot) != NULL) {
2775 		hammer2_inode_ref(ip);
2776 		hammer2_mtx_ex(&ip->lock);
2777 		hammer2_inode_chain_sync(ip);
2778 		hammer2_inode_chain_flush(ip, HAMMER2_XOP_INODE_STOP |
2779 					      HAMMER2_XOP_FSSYNC |
2780 					      HAMMER2_XOP_VOLHDR);
2781 		hammer2_inode_unlock(ip);	/* unlock+drop */
2782 	}
2783 #ifdef HAMMER2_DEBUG_SYNC
2784 	kprintf("FILESYSTEM SYNC STAGE 2 DONE\n");
2785 #endif
2786 
2787 	/*
2788 	 * device bioq sync
2789 	 */
2790 	hammer2_bioq_sync(pmp);
2791 
2792 	error = 0;	/* XXX */
2793 	hammer2_trans_done(pmp, HAMMER2_TRANS_ISFLUSH);
2794 
2795 	return (error);
2796 }
2797 
2798 static
2799 int
2800 hammer2_vfs_vptofh(struct vnode *vp, struct fid *fhp)
2801 {
2802 	hammer2_inode_t *ip;
2803 
2804 	KKASSERT(MAXFIDSZ >= 16);
2805 	ip = VTOI(vp);
2806 	fhp->fid_len = offsetof(struct fid, fid_data[16]);
2807 	fhp->fid_ext = 0;
2808 	((hammer2_tid_t *)fhp->fid_data)[0] = ip->meta.inum;
2809 	((hammer2_tid_t *)fhp->fid_data)[1] = 0;
2810 
2811 	return 0;
2812 }
2813 
2814 static
2815 int
2816 hammer2_vfs_fhtovp(struct mount *mp, struct vnode *rootvp,
2817 	       struct fid *fhp, struct vnode **vpp)
2818 {
2819 	hammer2_tid_t inum;
2820 	int error;
2821 
2822 	inum = ((hammer2_tid_t *)fhp->fid_data)[0] & HAMMER2_DIRHASH_USERMSK;
2823 	if (vpp) {
2824 		if (inum == 1)
2825 			error = hammer2_vfs_root(mp, vpp);
2826 		else
2827 			error = hammer2_vfs_vget(mp, NULL, inum, vpp);
2828 	} else {
2829 		error = 0;
2830 	}
2831 	return error;
2832 }
2833 
2834 static
2835 int
2836 hammer2_vfs_checkexp(struct mount *mp, struct sockaddr *nam,
2837 		 int *exflagsp, struct ucred **credanonp)
2838 {
2839 	hammer2_pfs_t *pmp;
2840 	struct netcred *np;
2841 	int error;
2842 
2843 	pmp = MPTOPMP(mp);
2844 	np = vfs_export_lookup(mp, &pmp->export, nam);
2845 	if (np) {
2846 		*exflagsp = np->netc_exflags;
2847 		*credanonp = &np->netc_anon;
2848 		error = 0;
2849 	} else {
2850 		error = EACCES;
2851 	}
2852 	return error;
2853 }
2854 
2855 /*
2856  * This handles hysteresis on regular file flushes.  Because the BIOs are
2857  * routed to a thread it is possible for an excessive number to build up
2858  * and cause long front-end stalls long before the runningbuffspace limit
2859  * is hit, so we implement hammer2_flush_pipe to control the
2860  * hysteresis.
2861  *
2862  * This is a particular problem when compression is used.
2863  */
2864 void
2865 hammer2_lwinprog_ref(hammer2_pfs_t *pmp)
2866 {
2867 	atomic_add_int(&pmp->count_lwinprog, 1);
2868 }
2869 
2870 void
2871 hammer2_lwinprog_drop(hammer2_pfs_t *pmp)
2872 {
2873 	int lwinprog;
2874 
2875 	lwinprog = atomic_fetchadd_int(&pmp->count_lwinprog, -1);
2876 	if ((lwinprog & HAMMER2_LWINPROG_WAITING) &&
2877 	    (lwinprog & HAMMER2_LWINPROG_MASK) <= hammer2_flush_pipe * 2 / 3) {
2878 		atomic_clear_int(&pmp->count_lwinprog,
2879 				 HAMMER2_LWINPROG_WAITING);
2880 		wakeup(&pmp->count_lwinprog);
2881 	}
2882 	if ((lwinprog & HAMMER2_LWINPROG_WAITING0) &&
2883 	    (lwinprog & HAMMER2_LWINPROG_MASK) <= 0) {
2884 		atomic_clear_int(&pmp->count_lwinprog,
2885 				 HAMMER2_LWINPROG_WAITING0);
2886 		wakeup(&pmp->count_lwinprog);
2887 	}
2888 }
2889 
2890 void
2891 hammer2_lwinprog_wait(hammer2_pfs_t *pmp, int flush_pipe)
2892 {
2893 	int lwinprog;
2894 	int lwflag = (flush_pipe) ? HAMMER2_LWINPROG_WAITING :
2895 				    HAMMER2_LWINPROG_WAITING0;
2896 
2897 	for (;;) {
2898 		lwinprog = pmp->count_lwinprog;
2899 		cpu_ccfence();
2900 		if ((lwinprog & HAMMER2_LWINPROG_MASK) <= flush_pipe)
2901 			break;
2902 		tsleep_interlock(&pmp->count_lwinprog, 0);
2903 		atomic_set_int(&pmp->count_lwinprog, lwflag);
2904 		lwinprog = pmp->count_lwinprog;
2905 		if ((lwinprog & HAMMER2_LWINPROG_MASK) <= flush_pipe)
2906 			break;
2907 		tsleep(&pmp->count_lwinprog, PINTERLOCKED, "h2wpipe", hz);
2908 	}
2909 }
2910 
2911 /*
2912  * It is possible for an excessive number of dirty chains or dirty inodes
2913  * to build up.  When this occurs we start an asynchronous filesystem sync.
2914  * If the level continues to build up, we stall, waiting for it to drop,
2915  * with some hysteresis.
2916  *
2917  * This relies on the kernel calling hammer2_vfs_modifying() prior to
2918  * obtaining any vnode locks before making a modifying VOP call.
2919  */
2920 static int
2921 hammer2_vfs_modifying(struct mount *mp)
2922 {
2923 	if (mp->mnt_flag & MNT_RDONLY)
2924 		return EROFS;
2925 	hammer2_pfs_memory_wait(MPTOPMP(mp));
2926 
2927 	return 0;
2928 }
2929 
2930 /*
2931  * Initiate an asynchronous filesystem sync and, with hysteresis,
2932  * stall if the internal data structure count becomes too bloated.
2933  */
2934 void
2935 hammer2_pfs_memory_wait(hammer2_pfs_t *pmp)
2936 {
2937 	uint32_t waiting;
2938 	int pcatch;
2939 	int error;
2940 
2941 	if (pmp == NULL || pmp->mp == NULL)
2942 		return;
2943 
2944 	for (;;) {
2945 		waiting = pmp->inmem_dirty_chains & HAMMER2_DIRTYCHAIN_MASK;
2946 		cpu_ccfence();
2947 
2948 		/*
2949 		 * Start the syncer running at 1/2 the limit
2950 		 */
2951 		if (waiting > hammer2_limit_dirty_chains / 2 ||
2952 		    pmp->sideq_count > hammer2_limit_dirty_inodes / 2) {
2953 			trigger_syncer(pmp->mp);
2954 		}
2955 
2956 		/*
2957 		 * Stall at the limit waiting for the counts to drop.
2958 		 * This code will typically be woken up once the count
2959 		 * drops below 3/4 the limit, or in one second.
2960 		 */
2961 		if (waiting < hammer2_limit_dirty_chains &&
2962 		    pmp->sideq_count < hammer2_limit_dirty_inodes) {
2963 			break;
2964 		}
2965 
2966 		pcatch = curthread->td_proc ? PCATCH : 0;
2967 
2968 		tsleep_interlock(&pmp->inmem_dirty_chains, pcatch);
2969 		atomic_set_int(&pmp->inmem_dirty_chains,
2970 			       HAMMER2_DIRTYCHAIN_WAITING);
2971 		if (waiting < hammer2_limit_dirty_chains &&
2972 		    pmp->sideq_count < hammer2_limit_dirty_inodes) {
2973 			break;
2974 		}
2975 		trigger_syncer(pmp->mp);
2976 		error = tsleep(&pmp->inmem_dirty_chains, PINTERLOCKED | pcatch,
2977 			       "h2memw", hz);
2978 		if (error == ERESTART)
2979 			break;
2980 	}
2981 }
2982 
2983 /*
2984  * Wake up any stalled frontend ops waiting, with hysteresis, using
2985  * 2/3 of the limit.
2986  */
2987 void
2988 hammer2_pfs_memory_wakeup(hammer2_pfs_t *pmp, int count)
2989 {
2990 	uint32_t waiting;
2991 
2992 	if (pmp) {
2993 		waiting = atomic_fetchadd_int(&pmp->inmem_dirty_chains, count);
2994 		/* don't need --waiting to test flag */
2995 
2996 		if ((waiting & HAMMER2_DIRTYCHAIN_WAITING) &&
2997 		    (pmp->inmem_dirty_chains & HAMMER2_DIRTYCHAIN_MASK) <=
2998 		    hammer2_limit_dirty_chains * 2 / 3 &&
2999 		    pmp->sideq_count <= hammer2_limit_dirty_inodes * 2 / 3) {
3000 			atomic_clear_int(&pmp->inmem_dirty_chains,
3001 					 HAMMER2_DIRTYCHAIN_WAITING);
3002 			wakeup(&pmp->inmem_dirty_chains);
3003 		}
3004 	}
3005 }
3006 
3007 void
3008 hammer2_pfs_memory_inc(hammer2_pfs_t *pmp)
3009 {
3010 	if (pmp) {
3011 		atomic_add_int(&pmp->inmem_dirty_chains, 1);
3012 	}
3013 }
3014 
3015 /*
3016  * Volume header data locks
3017  */
3018 void
3019 hammer2_voldata_lock(hammer2_dev_t *hmp)
3020 {
3021 	lockmgr(&hmp->vollk, LK_EXCLUSIVE);
3022 }
3023 
3024 void
3025 hammer2_voldata_unlock(hammer2_dev_t *hmp)
3026 {
3027 	lockmgr(&hmp->vollk, LK_RELEASE);
3028 }
3029 
3030 /*
3031  * Caller indicates that the volume header is being modified.  Flag
3032  * the related chain and adjust its transaction id.
3033  *
3034  * The transaction id is set to voldata.mirror_tid + 1, similar to
3035  * what hammer2_chain_modify() does.  Be very careful here, volume
3036  * data can be updated independently of the rest of the filesystem.
3037  */
3038 void
3039 hammer2_voldata_modify(hammer2_dev_t *hmp)
3040 {
3041 	if ((hmp->vchain.flags & HAMMER2_CHAIN_MODIFIED) == 0) {
3042 		atomic_add_long(&hammer2_count_modified_chains, 1);
3043 		atomic_set_int(&hmp->vchain.flags, HAMMER2_CHAIN_MODIFIED);
3044 		hammer2_pfs_memory_inc(hmp->vchain.pmp);
3045 		hmp->vchain.bref.mirror_tid = hmp->voldata.mirror_tid + 1;
3046 	}
3047 }
3048 
3049 /*
3050  * Returns 0 if the filesystem has tons of free space
3051  * Returns 1 if the filesystem has less than 10% remaining
3052  * Returns 2 if the filesystem has less than 2%/5% (user/root) remaining.
3053  */
3054 int
3055 hammer2_vfs_enospace(hammer2_inode_t *ip, off_t bytes, struct ucred *cred)
3056 {
3057 	hammer2_pfs_t *pmp;
3058 	hammer2_dev_t *hmp;
3059 	hammer2_off_t free_reserved;
3060 	hammer2_off_t free_nominal;
3061 	int i;
3062 
3063 	pmp = ip->pmp;
3064 
3065 	if (pmp->free_ticks == 0 || pmp->free_ticks != ticks) {
3066 		free_reserved = HAMMER2_SEGSIZE;
3067 		free_nominal = 0x7FFFFFFFFFFFFFFFLLU;
3068 		for (i = 0; i < pmp->iroot->cluster.nchains; ++i) {
3069 			hmp = pmp->pfs_hmps[i];
3070 			if (hmp == NULL)
3071 				continue;
3072 			if (pmp->pfs_types[i] != HAMMER2_PFSTYPE_MASTER &&
3073 			    pmp->pfs_types[i] != HAMMER2_PFSTYPE_SOFT_MASTER)
3074 				continue;
3075 
3076 			if (free_nominal > hmp->voldata.allocator_free)
3077 				free_nominal = hmp->voldata.allocator_free;
3078 			if (free_reserved < hmp->free_reserved)
3079 				free_reserved = hmp->free_reserved;
3080 		}
3081 
3082 		/*
3083 		 * SMP races ok
3084 		 */
3085 		pmp->free_reserved = free_reserved;
3086 		pmp->free_nominal = free_nominal;
3087 		pmp->free_ticks = ticks;
3088 	} else {
3089 		free_reserved = pmp->free_reserved;
3090 		free_nominal = pmp->free_nominal;
3091 	}
3092 	if (cred && cred->cr_uid != 0) {
3093 		if ((int64_t)(free_nominal - bytes) <
3094 		    (int64_t)free_reserved) {
3095 			return 2;
3096 		}
3097 	} else {
3098 		if ((int64_t)(free_nominal - bytes) <
3099 		    (int64_t)free_reserved / 2) {
3100 			return 2;
3101 		}
3102 	}
3103 	if ((int64_t)(free_nominal - bytes) < (int64_t)free_reserved * 2)
3104 		return 1;
3105 	return 0;
3106 }
3107