xref: /dragonfly/sys/vfs/hammer2/hammer2_vfsops.c (revision 19b217af)
1 /*-
2  * Copyright (c) 2011-2013 The DragonFly Project.  All rights reserved.
3  *
4  * This code is derived from software contributed to The DragonFly Project
5  * by Matthew Dillon <dillon@backplane.com>
6  * by Daniel Flores (GSOC 2013 - mentored by Matthew Dillon, compression)
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in
16  *    the documentation and/or other materials provided with the
17  *    distribution.
18  * 3. Neither the name of The DragonFly Project nor the names of its
19  *    contributors may be used to endorse or promote products derived
20  *    from this software without specific, prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
23  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
24  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
25  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
26  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
27  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
28  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
29  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
30  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
31  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
32  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/kernel.h>
38 #include <sys/nlookup.h>
39 #include <sys/vnode.h>
40 #include <sys/mount.h>
41 #include <sys/fcntl.h>
42 #include <sys/buf.h>
43 #include <sys/uuid.h>
44 #include <sys/vfsops.h>
45 #include <sys/sysctl.h>
46 #include <sys/socket.h>
47 #include <sys/objcache.h>
48 
49 #include <sys/proc.h>
50 #include <sys/namei.h>
51 #include <sys/mountctl.h>
52 #include <sys/dirent.h>
53 #include <sys/uio.h>
54 
55 #include <sys/mutex.h>
56 #include <sys/mutex2.h>
57 
58 #include "hammer2.h"
59 #include "hammer2_disk.h"
60 #include "hammer2_mount.h"
61 
62 #include "hammer2.h"
63 #include "hammer2_lz4.h"
64 
65 #include "zlib/hammer2_zlib.h"
66 
67 #define REPORT_REFS_ERRORS 1	/* XXX remove me */
68 
69 MALLOC_DEFINE(M_OBJCACHE, "objcache", "Object Cache");
70 
71 struct hammer2_sync_info {
72 	hammer2_trans_t trans;
73 	int error;
74 	int waitfor;
75 };
76 
77 TAILQ_HEAD(hammer2_mntlist, hammer2_mount);
78 static struct hammer2_mntlist hammer2_mntlist;
79 static struct lock hammer2_mntlk;
80 
81 int hammer2_debug;
82 int hammer2_cluster_enable = 1;
83 int hammer2_hardlink_enable = 1;
84 int hammer2_flush_pipe = 100;
85 long hammer2_limit_dirty_chains;
86 long hammer2_iod_file_read;
87 long hammer2_iod_meta_read;
88 long hammer2_iod_indr_read;
89 long hammer2_iod_fmap_read;
90 long hammer2_iod_volu_read;
91 long hammer2_iod_file_write;
92 long hammer2_iod_meta_write;
93 long hammer2_iod_indr_write;
94 long hammer2_iod_fmap_write;
95 long hammer2_iod_volu_write;
96 long hammer2_ioa_file_read;
97 long hammer2_ioa_meta_read;
98 long hammer2_ioa_indr_read;
99 long hammer2_ioa_fmap_read;
100 long hammer2_ioa_volu_read;
101 long hammer2_ioa_fmap_write;
102 long hammer2_ioa_file_write;
103 long hammer2_ioa_meta_write;
104 long hammer2_ioa_indr_write;
105 long hammer2_ioa_volu_write;
106 
107 MALLOC_DECLARE(C_BUFFER);
108 MALLOC_DEFINE(C_BUFFER, "compbuffer", "Buffer used for compression.");
109 
110 MALLOC_DECLARE(D_BUFFER);
111 MALLOC_DEFINE(D_BUFFER, "decompbuffer", "Buffer used for decompression.");
112 
113 SYSCTL_NODE(_vfs, OID_AUTO, hammer2, CTLFLAG_RW, 0, "HAMMER2 filesystem");
114 
115 SYSCTL_INT(_vfs_hammer2, OID_AUTO, debug, CTLFLAG_RW,
116 	   &hammer2_debug, 0, "");
117 SYSCTL_INT(_vfs_hammer2, OID_AUTO, cluster_enable, CTLFLAG_RW,
118 	   &hammer2_cluster_enable, 0, "");
119 SYSCTL_INT(_vfs_hammer2, OID_AUTO, hardlink_enable, CTLFLAG_RW,
120 	   &hammer2_hardlink_enable, 0, "");
121 SYSCTL_INT(_vfs_hammer2, OID_AUTO, flush_pipe, CTLFLAG_RW,
122 	   &hammer2_flush_pipe, 0, "");
123 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, limit_dirty_chains, CTLFLAG_RW,
124 	   &hammer2_limit_dirty_chains, 0, "");
125 
126 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_file_read, CTLFLAG_RW,
127 	   &hammer2_iod_file_read, 0, "");
128 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_meta_read, CTLFLAG_RW,
129 	   &hammer2_iod_meta_read, 0, "");
130 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_indr_read, CTLFLAG_RW,
131 	   &hammer2_iod_indr_read, 0, "");
132 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_fmap_read, CTLFLAG_RW,
133 	   &hammer2_iod_fmap_read, 0, "");
134 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_volu_read, CTLFLAG_RW,
135 	   &hammer2_iod_volu_read, 0, "");
136 
137 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_file_write, CTLFLAG_RW,
138 	   &hammer2_iod_file_write, 0, "");
139 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_meta_write, CTLFLAG_RW,
140 	   &hammer2_iod_meta_write, 0, "");
141 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_indr_write, CTLFLAG_RW,
142 	   &hammer2_iod_indr_write, 0, "");
143 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_fmap_write, CTLFLAG_RW,
144 	   &hammer2_iod_fmap_write, 0, "");
145 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, iod_volu_write, CTLFLAG_RW,
146 	   &hammer2_iod_volu_write, 0, "");
147 
148 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, ioa_file_read, CTLFLAG_RW,
149 	   &hammer2_ioa_file_read, 0, "");
150 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, ioa_meta_read, CTLFLAG_RW,
151 	   &hammer2_ioa_meta_read, 0, "");
152 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, ioa_indr_read, CTLFLAG_RW,
153 	   &hammer2_ioa_indr_read, 0, "");
154 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, ioa_fmap_read, CTLFLAG_RW,
155 	   &hammer2_ioa_fmap_read, 0, "");
156 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, ioa_volu_read, CTLFLAG_RW,
157 	   &hammer2_ioa_volu_read, 0, "");
158 
159 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, ioa_file_write, CTLFLAG_RW,
160 	   &hammer2_ioa_file_write, 0, "");
161 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, ioa_meta_write, CTLFLAG_RW,
162 	   &hammer2_ioa_meta_write, 0, "");
163 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, ioa_indr_write, CTLFLAG_RW,
164 	   &hammer2_ioa_indr_write, 0, "");
165 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, ioa_fmap_write, CTLFLAG_RW,
166 	   &hammer2_ioa_fmap_write, 0, "");
167 SYSCTL_LONG(_vfs_hammer2, OID_AUTO, ioa_volu_write, CTLFLAG_RW,
168 	   &hammer2_ioa_volu_write, 0, "");
169 
170 static int hammer2_vfs_init(struct vfsconf *conf);
171 static int hammer2_vfs_uninit(struct vfsconf *vfsp);
172 static int hammer2_vfs_mount(struct mount *mp, char *path, caddr_t data,
173 				struct ucred *cred);
174 static int hammer2_remount(hammer2_mount_t *, struct mount *, char *,
175 				struct vnode *, struct ucred *);
176 static int hammer2_recovery(hammer2_mount_t *hmp);
177 static int hammer2_vfs_unmount(struct mount *mp, int mntflags);
178 static int hammer2_vfs_root(struct mount *mp, struct vnode **vpp);
179 static int hammer2_vfs_statfs(struct mount *mp, struct statfs *sbp,
180 				struct ucred *cred);
181 static int hammer2_vfs_statvfs(struct mount *mp, struct statvfs *sbp,
182 				struct ucred *cred);
183 static int hammer2_vfs_vget(struct mount *mp, struct vnode *dvp,
184 				ino_t ino, struct vnode **vpp);
185 static int hammer2_vfs_fhtovp(struct mount *mp, struct vnode *rootvp,
186 				struct fid *fhp, struct vnode **vpp);
187 static int hammer2_vfs_vptofh(struct vnode *vp, struct fid *fhp);
188 static int hammer2_vfs_checkexp(struct mount *mp, struct sockaddr *nam,
189 				int *exflagsp, struct ucred **credanonp);
190 
191 static int hammer2_install_volume_header(hammer2_mount_t *hmp);
192 static int hammer2_sync_scan2(struct mount *mp, struct vnode *vp, void *data);
193 
194 static void hammer2_write_thread(void *arg);
195 
196 static void hammer2_vfs_unmount_hmp1(struct mount *mp, hammer2_mount_t *hmp);
197 static void hammer2_vfs_unmount_hmp2(struct mount *mp, hammer2_mount_t *hmp);
198 
199 /*
200  * Functions for compression in threads,
201  * from hammer2_vnops.c
202  */
203 static void hammer2_write_file_core(struct buf *bp, hammer2_trans_t *trans,
204 				hammer2_inode_t *ip,
205 				hammer2_inode_data_t *ipdata,
206 				hammer2_chain_t **parentp,
207 				hammer2_key_t lbase, int ioflag, int pblksize,
208 				int *errorp);
209 static void hammer2_compress_and_write(struct buf *bp, hammer2_trans_t *trans,
210 				hammer2_inode_t *ip,
211 				hammer2_inode_data_t *ipdata,
212 				hammer2_chain_t **parentp,
213 				hammer2_key_t lbase, int ioflag,
214 				int pblksize, int *errorp, int comp_algo);
215 static void hammer2_zero_check_and_write(struct buf *bp,
216 				hammer2_trans_t *trans, hammer2_inode_t *ip,
217 				hammer2_inode_data_t *ipdata,
218 				hammer2_chain_t **parentp,
219 				hammer2_key_t lbase,
220 				int ioflag, int pblksize, int *errorp);
221 static int test_block_zeros(const char *buf, size_t bytes);
222 static void zero_write(struct buf *bp, hammer2_trans_t *trans,
223 				hammer2_inode_t *ip,
224 				hammer2_inode_data_t *ipdata,
225 				hammer2_chain_t **parentp,
226 				hammer2_key_t lbase,
227 				int *errorp);
228 static void hammer2_write_bp(hammer2_chain_t *chain, struct buf *bp,
229 				int ioflag, int pblksize, int *errorp);
230 
231 static int hammer2_rcvdmsg(kdmsg_msg_t *msg);
232 static void hammer2_autodmsg(kdmsg_msg_t *msg);
233 
234 
235 /*
236  * HAMMER2 vfs operations.
237  */
238 static struct vfsops hammer2_vfsops = {
239 	.vfs_init	= hammer2_vfs_init,
240 	.vfs_uninit = hammer2_vfs_uninit,
241 	.vfs_sync	= hammer2_vfs_sync,
242 	.vfs_mount	= hammer2_vfs_mount,
243 	.vfs_unmount	= hammer2_vfs_unmount,
244 	.vfs_root 	= hammer2_vfs_root,
245 	.vfs_statfs	= hammer2_vfs_statfs,
246 	.vfs_statvfs	= hammer2_vfs_statvfs,
247 	.vfs_vget	= hammer2_vfs_vget,
248 	.vfs_vptofh	= hammer2_vfs_vptofh,
249 	.vfs_fhtovp	= hammer2_vfs_fhtovp,
250 	.vfs_checkexp	= hammer2_vfs_checkexp
251 };
252 
253 MALLOC_DEFINE(M_HAMMER2, "HAMMER2-mount", "");
254 
255 VFS_SET(hammer2_vfsops, hammer2, 0);
256 MODULE_VERSION(hammer2, 1);
257 
258 static
259 int
260 hammer2_vfs_init(struct vfsconf *conf)
261 {
262 	static struct objcache_malloc_args margs_read;
263 	static struct objcache_malloc_args margs_write;
264 
265 	int error;
266 
267 	error = 0;
268 
269 	if (HAMMER2_BLOCKREF_BYTES != sizeof(struct hammer2_blockref))
270 		error = EINVAL;
271 	if (HAMMER2_INODE_BYTES != sizeof(struct hammer2_inode_data))
272 		error = EINVAL;
273 	if (HAMMER2_VOLUME_BYTES != sizeof(struct hammer2_volume_data))
274 		error = EINVAL;
275 
276 	if (error)
277 		kprintf("HAMMER2 structure size mismatch; cannot continue.\n");
278 
279 	margs_read.objsize = 65536;
280 	margs_read.mtype = D_BUFFER;
281 
282 	margs_write.objsize = 32768;
283 	margs_write.mtype = C_BUFFER;
284 
285 	cache_buffer_read = objcache_create(margs_read.mtype->ks_shortdesc,
286 				0, 1, NULL, NULL, NULL, objcache_malloc_alloc,
287 				objcache_malloc_free, &margs_read);
288 	cache_buffer_write = objcache_create(margs_write.mtype->ks_shortdesc,
289 				0, 1, NULL, NULL, NULL, objcache_malloc_alloc,
290 				objcache_malloc_free, &margs_write);
291 
292 	lockinit(&hammer2_mntlk, "mntlk", 0, 0);
293 	TAILQ_INIT(&hammer2_mntlist);
294 
295 	hammer2_limit_dirty_chains = desiredvnodes / 10;
296 
297 	return (error);
298 }
299 
300 static
301 int
302 hammer2_vfs_uninit(struct vfsconf *vfsp __unused)
303 {
304 	objcache_destroy(cache_buffer_read);
305 	objcache_destroy(cache_buffer_write);
306 	return 0;
307 }
308 
309 /*
310  * Mount or remount HAMMER2 fileystem from physical media
311  *
312  *	mountroot
313  *		mp		mount point structure
314  *		path		NULL
315  *		data		<unused>
316  *		cred		<unused>
317  *
318  *	mount
319  *		mp		mount point structure
320  *		path		path to mount point
321  *		data		pointer to argument structure in user space
322  *			volume	volume path (device@LABEL form)
323  *			hflags	user mount flags
324  *		cred		user credentials
325  *
326  * RETURNS:	0	Success
327  *		!0	error number
328  */
329 static
330 int
331 hammer2_vfs_mount(struct mount *mp, char *path, caddr_t data,
332 		  struct ucred *cred)
333 {
334 	struct hammer2_mount_info info;
335 	hammer2_pfsmount_t *pmp;
336 	hammer2_mount_t *hmp;
337 	hammer2_key_t key_next;
338 	hammer2_key_t key_dummy;
339 	hammer2_key_t lhc;
340 	struct vnode *devvp;
341 	struct nlookupdata nd;
342 	hammer2_chain_t *parent;
343 	hammer2_chain_t *schain;
344 	hammer2_chain_t *rchain;
345 	struct file *fp;
346 	char devstr[MNAMELEN];
347 	size_t size;
348 	size_t done;
349 	char *dev;
350 	char *label;
351 	int ronly = 1;
352 	int error;
353 	int cache_index;
354 	int i;
355 
356 	hmp = NULL;
357 	pmp = NULL;
358 	dev = NULL;
359 	label = NULL;
360 	devvp = NULL;
361 	cache_index = -1;
362 
363 	kprintf("hammer2_mount\n");
364 
365 	if (path == NULL) {
366 		/*
367 		 * Root mount
368 		 */
369 		bzero(&info, sizeof(info));
370 		info.cluster_fd = -1;
371 		return (EOPNOTSUPP);
372 	} else {
373 		/*
374 		 * Non-root mount or updating a mount
375 		 */
376 		error = copyin(data, &info, sizeof(info));
377 		if (error)
378 			return (error);
379 
380 		error = copyinstr(info.volume, devstr, MNAMELEN - 1, &done);
381 		if (error)
382 			return (error);
383 
384 		/* Extract device and label */
385 		dev = devstr;
386 		label = strchr(devstr, '@');
387 		if (label == NULL ||
388 		    ((label + 1) - dev) > done) {
389 			return (EINVAL);
390 		}
391 		*label = '\0';
392 		label++;
393 		if (*label == '\0')
394 			return (EINVAL);
395 
396 		if (mp->mnt_flag & MNT_UPDATE) {
397 			/* Update mount */
398 			/* HAMMER2 implements NFS export via mountctl */
399 			pmp = MPTOPMP(mp);
400 			for (i = 0; i < pmp->cluster.nchains; ++i) {
401 				hmp = pmp->cluster.chains[i]->hmp;
402 				devvp = hmp->devvp;
403 				error = hammer2_remount(hmp, mp, path,
404 							devvp, cred);
405 				if (error)
406 					break;
407 			}
408 			return error;
409 		}
410 	}
411 
412 	/*
413 	 * PFS mount
414 	 *
415 	 * Lookup name and verify it refers to a block device.
416 	 */
417 	error = nlookup_init(&nd, dev, UIO_SYSSPACE, NLC_FOLLOW);
418 	if (error == 0)
419 		error = nlookup(&nd);
420 	if (error == 0)
421 		error = cache_vref(&nd.nl_nch, nd.nl_cred, &devvp);
422 	nlookup_done(&nd);
423 
424 	if (error == 0) {
425 		if (vn_isdisk(devvp, &error))
426 			error = vfs_mountedon(devvp);
427 	}
428 
429 	/*
430 	 * Determine if the device has already been mounted.  After this
431 	 * check hmp will be non-NULL if we are doing the second or more
432 	 * hammer2 mounts from the same device.
433 	 */
434 	lockmgr(&hammer2_mntlk, LK_EXCLUSIVE);
435 	TAILQ_FOREACH(hmp, &hammer2_mntlist, mntentry) {
436 		if (hmp->devvp == devvp)
437 			break;
438 	}
439 
440 	/*
441 	 * Open the device if this isn't a secondary mount and construct
442 	 * the H2 device mount (hmp).
443 	 */
444 	if (hmp == NULL) {
445 		if (error == 0 && vcount(devvp) > 0)
446 			error = EBUSY;
447 
448 		/*
449 		 * Now open the device
450 		 */
451 		if (error == 0) {
452 			ronly = ((mp->mnt_flag & MNT_RDONLY) != 0);
453 			vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
454 			error = vinvalbuf(devvp, V_SAVE, 0, 0);
455 			if (error == 0) {
456 				error = VOP_OPEN(devvp,
457 						 ronly ? FREAD : FREAD | FWRITE,
458 						 FSCRED, NULL);
459 			}
460 			vn_unlock(devvp);
461 		}
462 		if (error && devvp) {
463 			vrele(devvp);
464 			devvp = NULL;
465 		}
466 		if (error) {
467 			lockmgr(&hammer2_mntlk, LK_RELEASE);
468 			return error;
469 		}
470 		hmp = kmalloc(sizeof(*hmp), M_HAMMER2, M_WAITOK | M_ZERO);
471 		hmp->ronly = ronly;
472 		hmp->devvp = devvp;
473 		kmalloc_create(&hmp->mchain, "HAMMER2-chains");
474 		TAILQ_INSERT_TAIL(&hammer2_mntlist, hmp, mntentry);
475 		RB_INIT(&hmp->iotree);
476 
477 		lockinit(&hmp->alloclk, "h2alloc", 0, 0);
478 		lockinit(&hmp->voldatalk, "voldata", 0, LK_CANRECURSE);
479 		TAILQ_INIT(&hmp->transq);
480 
481 		/*
482 		 * vchain setup. vchain.data is embedded.
483 		 * vchain.refs is initialized and will never drop to 0.
484 		 *
485 		 * NOTE! voldata is not yet loaded.
486 		 */
487 		hmp->vchain.hmp = hmp;
488 		hmp->vchain.refs = 1;
489 		hmp->vchain.data = (void *)&hmp->voldata;
490 		hmp->vchain.bref.type = HAMMER2_BREF_TYPE_VOLUME;
491 		hmp->vchain.bref.data_off = 0 | HAMMER2_PBUFRADIX;
492 		hmp->vchain.delete_tid = HAMMER2_MAX_TID;
493 
494 		hammer2_chain_core_alloc(NULL, &hmp->vchain, NULL);
495 		/* hmp->vchain.u.xxx is left NULL */
496 
497 		/*
498 		 * fchain setup.  fchain.data is embedded.
499 		 * fchain.refs is initialized and will never drop to 0.
500 		 *
501 		 * The data is not used but needs to be initialized to
502 		 * pass assertion muster.  We use this chain primarily
503 		 * as a placeholder for the freemap's top-level RBTREE
504 		 * so it does not interfere with the volume's topology
505 		 * RBTREE.
506 		 */
507 		hmp->fchain.hmp = hmp;
508 		hmp->fchain.refs = 1;
509 		hmp->fchain.data = (void *)&hmp->voldata.freemap_blockset;
510 		hmp->fchain.bref.type = HAMMER2_BREF_TYPE_FREEMAP;
511 		hmp->fchain.bref.data_off = 0 | HAMMER2_PBUFRADIX;
512 		hmp->fchain.bref.methods =
513 			HAMMER2_ENC_CHECK(HAMMER2_CHECK_FREEMAP) |
514 			HAMMER2_ENC_COMP(HAMMER2_COMP_NONE);
515 		hmp->fchain.delete_tid = HAMMER2_MAX_TID;
516 
517 		hammer2_chain_core_alloc(NULL, &hmp->fchain, NULL);
518 		/* hmp->fchain.u.xxx is left NULL */
519 
520 		/*
521 		 * Install the volume header and initialize fields from
522 		 * voldata.
523 		 */
524 		error = hammer2_install_volume_header(hmp);
525 		if (error) {
526 			++hmp->pmp_count;
527 			hammer2_vfs_unmount_hmp1(mp, hmp);
528 			hammer2_vfs_unmount_hmp2(mp, hmp);
529 			hammer2_vfs_unmount(mp, MNT_FORCE);
530 			return error;
531 		}
532 
533 		hmp->vchain.bref.mirror_tid = hmp->voldata.mirror_tid;
534 		hmp->vchain.modify_tid = hmp->voldata.mirror_tid;
535 		hmp->fchain.bref.mirror_tid = hmp->voldata.freemap_tid;
536 		hmp->fchain.modify_tid = hmp->voldata.freemap_tid;
537 
538 		/*
539 		 * First locate the super-root inode, which is key 0
540 		 * relative to the volume header's blockset.
541 		 *
542 		 * Then locate the root inode by scanning the directory keyspace
543 		 * represented by the label.
544 		 */
545 		parent = hammer2_chain_lookup_init(&hmp->vchain, 0);
546 		schain = hammer2_chain_lookup(&parent, &key_dummy,
547 				      HAMMER2_SROOT_KEY, HAMMER2_SROOT_KEY,
548 				      &cache_index, 0);
549 		hammer2_chain_lookup_done(parent);
550 		if (schain == NULL) {
551 			kprintf("hammer2_mount: invalid super-root\n");
552 			++hmp->pmp_count;
553 			hammer2_vfs_unmount_hmp1(mp, hmp);
554 			hammer2_vfs_unmount_hmp2(mp, hmp);
555 			hammer2_vfs_unmount(mp, MNT_FORCE);
556 			return EINVAL;
557 		}
558 
559 		/*
560 		 * NOTE: inode_get sucks up schain's lock.
561 		 */
562 		atomic_set_int(&schain->flags, HAMMER2_CHAIN_PFSROOT);
563 		hmp->sroot = hammer2_inode_get(NULL, NULL, schain);
564 		hammer2_inode_ref(hmp->sroot);
565 		hammer2_inode_unlock_ex(hmp->sroot, schain);
566 		schain = NULL;
567 		/* leave hmp->sroot with one ref */
568 
569 		if ((mp->mnt_flag & MNT_RDONLY) == 0) {
570 			error = hammer2_recovery(hmp);
571 			/* XXX do something with error */
572 		}
573 	}
574 
575 	/*
576 	 * Block device opened successfully, finish initializing the
577 	 * mount structure.
578 	 *
579 	 * From this point on we have to call hammer2_unmount() on failure.
580 	 */
581 	pmp = kmalloc(sizeof(*pmp), M_HAMMER2, M_WAITOK | M_ZERO);
582 
583 	kmalloc_create(&pmp->minode, "HAMMER2-inodes");
584 	kmalloc_create(&pmp->mmsg, "HAMMER2-pfsmsg");
585 
586 	spin_init(&pmp->inum_spin);
587 	RB_INIT(&pmp->inum_tree);
588 
589 	kdmsg_iocom_init(&pmp->iocom, pmp,
590 			 KDMSG_IOCOMF_AUTOCONN |
591 			 KDMSG_IOCOMF_AUTOSPAN |
592 			 KDMSG_IOCOMF_AUTOCIRC,
593 			 pmp->mmsg, hammer2_rcvdmsg);
594 
595 	ccms_domain_init(&pmp->ccms_dom);
596 	++hmp->pmp_count;
597 	lockmgr(&hammer2_mntlk, LK_RELEASE);
598 	kprintf("hammer2_mount hmp=%p pmp=%p pmpcnt=%d\n",
599 		hmp, pmp, hmp->pmp_count);
600 
601 	mp->mnt_flag = MNT_LOCAL;
602 	mp->mnt_kern_flag |= MNTK_ALL_MPSAFE;	/* all entry pts are SMP */
603 	mp->mnt_kern_flag |= MNTK_THR_SYNC;	/* new vsyncscan semantics */
604 
605 	/*
606 	 * required mount structure initializations
607 	 */
608 	mp->mnt_stat.f_iosize = HAMMER2_PBUFSIZE;
609 	mp->mnt_stat.f_bsize = HAMMER2_PBUFSIZE;
610 
611 	mp->mnt_vstat.f_frsize = HAMMER2_PBUFSIZE;
612 	mp->mnt_vstat.f_bsize = HAMMER2_PBUFSIZE;
613 
614 	/*
615 	 * Optional fields
616 	 */
617 	mp->mnt_iosize_max = MAXPHYS;
618 	mp->mnt_data = (qaddr_t)pmp;
619 	pmp->mp = mp;
620 
621 	/*
622 	 * Lookup mount point under the media-localized super-root.
623 	 */
624 	parent = hammer2_inode_lock_ex(hmp->sroot);
625 	lhc = hammer2_dirhash(label, strlen(label));
626 	rchain = hammer2_chain_lookup(&parent, &key_next,
627 				      lhc, lhc + HAMMER2_DIRHASH_LOMASK,
628 				      &cache_index, 0);
629 	while (rchain) {
630 		if (rchain->bref.type == HAMMER2_BREF_TYPE_INODE &&
631 		    strcmp(label, rchain->data->ipdata.filename) == 0) {
632 			break;
633 		}
634 		rchain = hammer2_chain_next(&parent, rchain, &key_next,
635 					    key_next,
636 					    lhc + HAMMER2_DIRHASH_LOMASK,
637 					    &cache_index, 0);
638 	}
639 	hammer2_inode_unlock_ex(hmp->sroot, parent);
640 
641 	if (rchain == NULL) {
642 		kprintf("hammer2_mount: PFS label not found\n");
643 		hammer2_vfs_unmount_hmp1(mp, hmp);
644 		hammer2_vfs_unmount_hmp2(mp, hmp);
645 		hammer2_vfs_unmount(mp, MNT_FORCE);
646 		return EINVAL;
647 	}
648 	if (rchain->flags & HAMMER2_CHAIN_MOUNTED) {
649 		hammer2_chain_unlock(rchain);
650 		kprintf("hammer2_mount: PFS label already mounted!\n");
651 		hammer2_vfs_unmount_hmp1(mp, hmp);
652 		hammer2_vfs_unmount_hmp2(mp, hmp);
653 		hammer2_vfs_unmount(mp, MNT_FORCE);
654 		return EBUSY;
655 	}
656 #if 0
657 	if (rchain->flags & HAMMER2_CHAIN_RECYCLE) {
658 		kprintf("hammer2_mount: PFS label currently recycling\n");
659 		hammer2_vfs_unmount_hmp1(mp, hmp);
660 		hammer2_vfs_unmount_hmp2(mp, hmp);
661 		hammer2_vfs_unmount(mp, MNT_FORCE);
662 		return EBUSY;
663 	}
664 #endif
665 	/*
666 	 * After this point hammer2_vfs_unmount() has visibility on hmp
667 	 * and manual hmp1/hmp2 calls are not needed on fatal errors.
668 	 */
669 
670 	atomic_set_int(&rchain->flags, HAMMER2_CHAIN_MOUNTED);
671 
672 	/*
673 	 * NOTE: *_get() integrates chain's lock into the inode lock.
674 	 */
675 	hammer2_chain_ref(rchain);		/* for pmp->rchain */
676 	pmp->cluster.nchains = 1;
677 	pmp->cluster.chains[0] = rchain;
678 	pmp->iroot = hammer2_inode_get(pmp, NULL, rchain);
679 	hammer2_inode_ref(pmp->iroot);		/* ref for pmp->iroot */
680 
681 	KKASSERT(rchain->pmp == NULL);		/* tracking pmp for rchain */
682 	rchain->pmp = pmp;
683 
684 	hammer2_inode_unlock_ex(pmp->iroot, rchain);
685 
686 	kprintf("iroot %p\n", pmp->iroot);
687 
688 	/*
689 	 * The logical file buffer bio write thread handles things
690 	 * like physical block assignment and compression.
691 	 */
692 	mtx_init(&pmp->wthread_mtx);
693 	bioq_init(&pmp->wthread_bioq);
694 	pmp->wthread_destroy = 0;
695 	lwkt_create(hammer2_write_thread, pmp,
696 		    &pmp->wthread_td, NULL, 0, -1, "hwrite-%s", label);
697 
698 	/*
699 	 * Ref the cluster management messaging descriptor.  The mount
700 	 * program deals with the other end of the communications pipe.
701 	 */
702 	fp = holdfp(curproc->p_fd, info.cluster_fd, -1);
703 	if (fp == NULL) {
704 		kprintf("hammer2_mount: bad cluster_fd!\n");
705 		hammer2_vfs_unmount(mp, MNT_FORCE);
706 		return EBADF;
707 	}
708 	hammer2_cluster_reconnect(pmp, fp);
709 
710 	/*
711 	 * Finish setup
712 	 */
713 	vfs_getnewfsid(mp);
714 	vfs_add_vnodeops(mp, &hammer2_vnode_vops, &mp->mnt_vn_norm_ops);
715 	vfs_add_vnodeops(mp, &hammer2_spec_vops, &mp->mnt_vn_spec_ops);
716 	vfs_add_vnodeops(mp, &hammer2_fifo_vops, &mp->mnt_vn_fifo_ops);
717 
718 	copyinstr(info.volume, mp->mnt_stat.f_mntfromname, MNAMELEN - 1, &size);
719 	bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
720 	bzero(mp->mnt_stat.f_mntonname, sizeof(mp->mnt_stat.f_mntonname));
721 	copyinstr(path, mp->mnt_stat.f_mntonname,
722 		  sizeof(mp->mnt_stat.f_mntonname) - 1,
723 		  &size);
724 
725 	/*
726 	 * Initial statfs to prime mnt_stat.
727 	 */
728 	hammer2_vfs_statfs(mp, &mp->mnt_stat, cred);
729 
730 	return 0;
731 }
732 
733 /*
734  * Handle bioq for strategy write
735  */
736 static
737 void
738 hammer2_write_thread(void *arg)
739 {
740 	hammer2_pfsmount_t *pmp;
741 	struct bio *bio;
742 	struct buf *bp;
743 	hammer2_trans_t trans;
744 	struct vnode *vp;
745 	hammer2_inode_t *ip;
746 	hammer2_chain_t *parent;
747 	hammer2_chain_t **parentp;
748 	hammer2_inode_data_t *ipdata;
749 	hammer2_key_t lbase;
750 	int lblksize;
751 	int pblksize;
752 	int error;
753 
754 	pmp = arg;
755 
756 	mtx_lock(&pmp->wthread_mtx);
757 	while (pmp->wthread_destroy == 0) {
758 		if (bioq_first(&pmp->wthread_bioq) == NULL) {
759 			mtxsleep(&pmp->wthread_bioq, &pmp->wthread_mtx,
760 				 0, "h2bioqw", 0);
761 		}
762 		parent = NULL;
763 		parentp = &parent;
764 
765 		hammer2_trans_init(&trans, pmp, NULL, HAMMER2_TRANS_BUFCACHE);
766 
767 		while ((bio = bioq_takefirst(&pmp->wthread_bioq)) != NULL) {
768 			/*
769 			 * dummy bio for synchronization.  The transaction
770 			 * must be reinitialized.
771 			 */
772 			if (bio->bio_buf == NULL) {
773 				bio->bio_flags |= BIO_DONE;
774 				wakeup(bio);
775 				hammer2_trans_done(&trans);
776 				hammer2_trans_init(&trans, pmp, NULL,
777 						   HAMMER2_TRANS_BUFCACHE);
778 				continue;
779 			}
780 
781 			/*
782 			 * else normal bio processing
783 			 */
784 			mtx_unlock(&pmp->wthread_mtx);
785 
786 			hammer2_lwinprog_drop(pmp);
787 
788 			error = 0;
789 			bp = bio->bio_buf;
790 			vp = bp->b_vp;
791 			ip = VTOI(vp);
792 
793 			/*
794 			 * Inode is modified, flush size and mtime changes
795 			 * to ensure that the file size remains consistent
796 			 * with the buffers being flushed.
797 			 */
798 			parent = hammer2_inode_lock_ex(ip);
799 			if (ip->flags & (HAMMER2_INODE_RESIZED |
800 					 HAMMER2_INODE_MTIME)) {
801 				hammer2_inode_fsync(&trans, ip, parentp);
802 			}
803 			ipdata = hammer2_chain_modify_ip(&trans, ip,
804 							 parentp, 0);
805 			lblksize = hammer2_calc_logical(ip, bio->bio_offset,
806 							&lbase, NULL);
807 			pblksize = hammer2_calc_physical(ip, lbase);
808 			hammer2_write_file_core(bp, &trans, ip, ipdata,
809 						parentp,
810 						lbase, IO_ASYNC,
811 						pblksize, &error);
812 			hammer2_inode_unlock_ex(ip, parent);
813 			if (error) {
814 				kprintf("hammer2: error in buffer write\n");
815 				bp->b_flags |= B_ERROR;
816 				bp->b_error = EIO;
817 			}
818 			biodone(bio);
819 			mtx_lock(&pmp->wthread_mtx);
820 		}
821 		hammer2_trans_done(&trans);
822 	}
823 	pmp->wthread_destroy = -1;
824 	wakeup(&pmp->wthread_destroy);
825 
826 	mtx_unlock(&pmp->wthread_mtx);
827 }
828 
829 void
830 hammer2_bioq_sync(hammer2_pfsmount_t *pmp)
831 {
832 	struct bio sync_bio;
833 
834 	bzero(&sync_bio, sizeof(sync_bio));	/* dummy with no bio_buf */
835 	mtx_lock(&pmp->wthread_mtx);
836 	if (pmp->wthread_destroy == 0) {
837 		if (TAILQ_EMPTY(&pmp->wthread_bioq.queue)) {
838 		       bioq_insert_tail(&pmp->wthread_bioq, &sync_bio);
839 		       wakeup(&pmp->wthread_bioq);
840 		} else {
841 		       bioq_insert_tail(&pmp->wthread_bioq, &sync_bio);
842 		}
843 		while ((sync_bio.bio_flags & BIO_DONE) == 0)
844 			mtxsleep(&sync_bio, &pmp->wthread_mtx, 0, "h2bioq", 0);
845 	}
846 	mtx_unlock(&pmp->wthread_mtx);
847 }
848 
849 /*
850  * Return a chain suitable for I/O, creating the chain if necessary
851  * and assigning its physical block.
852  */
853 static
854 hammer2_chain_t *
855 hammer2_assign_physical(hammer2_trans_t *trans,
856 			hammer2_inode_t *ip, hammer2_chain_t **parentp,
857 			hammer2_key_t lbase, int pblksize, int *errorp)
858 {
859 	hammer2_chain_t *parent;
860 	hammer2_chain_t *chain;
861 	hammer2_off_t pbase;
862 	hammer2_key_t key_dummy;
863 	int pradix = hammer2_getradix(pblksize);
864 	int cache_index = -1;
865 
866 	/*
867 	 * Locate the chain associated with lbase, return a locked chain.
868 	 * However, do not instantiate any data reference (which utilizes a
869 	 * device buffer) because we will be using direct IO via the
870 	 * logical buffer cache buffer.
871 	 */
872 	*errorp = 0;
873 	KKASSERT(pblksize >= HAMMER2_MIN_ALLOC);
874 retry:
875 	parent = *parentp;
876 	hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS); /* extra lock */
877 	chain = hammer2_chain_lookup(&parent, &key_dummy,
878 				     lbase, lbase,
879 				     &cache_index, HAMMER2_LOOKUP_NODATA);
880 
881 	if (chain == NULL) {
882 		/*
883 		 * We found a hole, create a new chain entry.
884 		 *
885 		 * NOTE: DATA chains are created without device backing
886 		 *	 store (nor do we want any).
887 		 */
888 		*errorp = hammer2_chain_create(trans, &parent, &chain,
889 					       lbase, HAMMER2_PBUFRADIX,
890 					       HAMMER2_BREF_TYPE_DATA,
891 					       pblksize);
892 		if (chain == NULL) {
893 			hammer2_chain_lookup_done(parent);
894 			panic("hammer2_chain_create: par=%p error=%d\n",
895 				parent, *errorp);
896 			goto retry;
897 		}
898 
899 		pbase = chain->bref.data_off & ~HAMMER2_OFF_MASK_RADIX;
900 		/*ip->delta_dcount += pblksize;*/
901 	} else {
902 		switch (chain->bref.type) {
903 		case HAMMER2_BREF_TYPE_INODE:
904 			/*
905 			 * The data is embedded in the inode.  The
906 			 * caller is responsible for marking the inode
907 			 * modified and copying the data to the embedded
908 			 * area.
909 			 */
910 			pbase = NOOFFSET;
911 			break;
912 		case HAMMER2_BREF_TYPE_DATA:
913 			if (chain->bytes != pblksize) {
914 				hammer2_chain_resize(trans, ip,
915 						     parent, &chain,
916 						     pradix,
917 						     HAMMER2_MODIFY_OPTDATA);
918 			}
919 			hammer2_chain_modify(trans, &chain,
920 					     HAMMER2_MODIFY_OPTDATA);
921 			pbase = chain->bref.data_off & ~HAMMER2_OFF_MASK_RADIX;
922 			break;
923 		default:
924 			panic("hammer2_assign_physical: bad type");
925 			/* NOT REACHED */
926 			pbase = NOOFFSET;
927 			break;
928 		}
929 	}
930 
931 	/*
932 	 * Cleanup.  If chain wound up being the inode (i.e. DIRECTDATA),
933 	 * we might have to replace *parentp.
934 	 */
935 	hammer2_chain_lookup_done(parent);
936 	if (chain) {
937 		if (*parentp != chain &&
938 		    (*parentp)->core == chain->core) {
939 			parent = *parentp;
940 			*parentp = chain;		/* eats lock */
941 			hammer2_chain_unlock(parent);
942 			hammer2_chain_lock(chain, 0);	/* need another */
943 		}
944 		/* else chain already locked for return */
945 	}
946 	return (chain);
947 }
948 
949 /*
950  * From hammer2_vnops.c.
951  * The core write function which determines which path to take
952  * depending on compression settings.
953  */
954 static
955 void
956 hammer2_write_file_core(struct buf *bp, hammer2_trans_t *trans,
957 			hammer2_inode_t *ip, hammer2_inode_data_t *ipdata,
958 			hammer2_chain_t **parentp,
959 			hammer2_key_t lbase, int ioflag, int pblksize,
960 			int *errorp)
961 {
962 	hammer2_chain_t *chain;
963 
964 	switch(HAMMER2_DEC_COMP(ipdata->comp_algo)) {
965 	case HAMMER2_COMP_NONE:
966 		/*
967 		 * We have to assign physical storage to the buffer
968 		 * we intend to dirty or write now to avoid deadlocks
969 		 * in the strategy code later.
970 		 *
971 		 * This can return NOOFFSET for inode-embedded data.
972 		 * The strategy code will take care of it in that case.
973 		 */
974 		chain = hammer2_assign_physical(trans, ip, parentp,
975 						lbase, pblksize,
976 						errorp);
977 		hammer2_write_bp(chain, bp, ioflag, pblksize, errorp);
978 		if (chain)
979 			hammer2_chain_unlock(chain);
980 		break;
981 	case HAMMER2_COMP_AUTOZERO:
982 		/*
983 		 * Check for zero-fill only
984 		 */
985 		hammer2_zero_check_and_write(bp, trans, ip,
986 				    ipdata, parentp, lbase,
987 				    ioflag, pblksize, errorp);
988 		break;
989 	case HAMMER2_COMP_LZ4:
990 	case HAMMER2_COMP_ZLIB:
991 	default:
992 		/*
993 		 * Check for zero-fill and attempt compression.
994 		 */
995 		hammer2_compress_and_write(bp, trans, ip,
996 					   ipdata, parentp,
997 					   lbase, ioflag,
998 					   pblksize, errorp,
999 					   ipdata->comp_algo);
1000 		break;
1001 	}
1002 	ipdata = &ip->chain->data->ipdata;	/* reload */
1003 }
1004 
1005 /*
1006  * From hammer2_vnops.c
1007  * Generic function that will perform the compression in compression
1008  * write path. The compression algorithm is determined by the settings
1009  * obtained from inode.
1010  */
1011 static
1012 void
1013 hammer2_compress_and_write(struct buf *bp, hammer2_trans_t *trans,
1014 	hammer2_inode_t *ip, hammer2_inode_data_t *ipdata,
1015 	hammer2_chain_t **parentp,
1016 	hammer2_key_t lbase, int ioflag, int pblksize,
1017 	int *errorp, int comp_algo)
1018 {
1019 	hammer2_chain_t *chain;
1020 	int comp_size;
1021 	int comp_block_size;
1022 	char *comp_buffer;
1023 
1024 	if (test_block_zeros(bp->b_data, pblksize)) {
1025 		zero_write(bp, trans, ip, ipdata, parentp, lbase, errorp);
1026 		return;
1027 	}
1028 
1029 	comp_size = 0;
1030 	comp_buffer = NULL;
1031 
1032 	KKASSERT(pblksize / 2 <= 32768);
1033 
1034 	if (ip->comp_heuristic < 8 || (ip->comp_heuristic & 7) == 0) {
1035 		z_stream strm_compress;
1036 		int comp_level;
1037 		int ret;
1038 
1039 		switch(HAMMER2_DEC_COMP(comp_algo)) {
1040 		case HAMMER2_COMP_LZ4:
1041 			comp_buffer = objcache_get(cache_buffer_write,
1042 						   M_INTWAIT);
1043 			comp_size = LZ4_compress_limitedOutput(
1044 					bp->b_data,
1045 					&comp_buffer[sizeof(int)],
1046 					pblksize,
1047 					pblksize / 2 - sizeof(int));
1048 			/*
1049 			 * We need to prefix with the size, LZ4
1050 			 * doesn't do it for us.  Add the related
1051 			 * overhead.
1052 			 */
1053 			*(int *)comp_buffer = comp_size;
1054 			if (comp_size)
1055 				comp_size += sizeof(int);
1056 			break;
1057 		case HAMMER2_COMP_ZLIB:
1058 			comp_level = HAMMER2_DEC_LEVEL(comp_algo);
1059 			if (comp_level == 0)
1060 				comp_level = 6;	/* default zlib compression */
1061 			else if (comp_level < 6)
1062 				comp_level = 6;
1063 			else if (comp_level > 9)
1064 				comp_level = 9;
1065 			ret = deflateInit(&strm_compress, comp_level);
1066 			if (ret != Z_OK) {
1067 				kprintf("HAMMER2 ZLIB: fatal error "
1068 					"on deflateInit.\n");
1069 			}
1070 
1071 			comp_buffer = objcache_get(cache_buffer_write,
1072 						   M_INTWAIT);
1073 			strm_compress.next_in = bp->b_data;
1074 			strm_compress.avail_in = pblksize;
1075 			strm_compress.next_out = comp_buffer;
1076 			strm_compress.avail_out = pblksize / 2;
1077 			ret = deflate(&strm_compress, Z_FINISH);
1078 			if (ret == Z_STREAM_END) {
1079 				comp_size = pblksize / 2 -
1080 					    strm_compress.avail_out;
1081 			} else {
1082 				comp_size = 0;
1083 			}
1084 			ret = deflateEnd(&strm_compress);
1085 			break;
1086 		default:
1087 			kprintf("Error: Unknown compression method.\n");
1088 			kprintf("Comp_method = %d.\n", comp_algo);
1089 			break;
1090 		}
1091 	}
1092 
1093 	if (comp_size == 0) {
1094 		/*
1095 		 * compression failed or turned off
1096 		 */
1097 		comp_block_size = pblksize;	/* safety */
1098 		if (++ip->comp_heuristic > 128)
1099 			ip->comp_heuristic = 8;
1100 	} else {
1101 		/*
1102 		 * compression succeeded
1103 		 */
1104 		ip->comp_heuristic = 0;
1105 		if (comp_size <= 1024) {
1106 			comp_block_size = 1024;
1107 		} else if (comp_size <= 2048) {
1108 			comp_block_size = 2048;
1109 		} else if (comp_size <= 4096) {
1110 			comp_block_size = 4096;
1111 		} else if (comp_size <= 8192) {
1112 			comp_block_size = 8192;
1113 		} else if (comp_size <= 16384) {
1114 			comp_block_size = 16384;
1115 		} else if (comp_size <= 32768) {
1116 			comp_block_size = 32768;
1117 		} else {
1118 			panic("hammer2: WRITE PATH: "
1119 			      "Weird comp_size value.");
1120 			/* NOT REACHED */
1121 			comp_block_size = pblksize;
1122 		}
1123 	}
1124 
1125 	chain = hammer2_assign_physical(trans, ip, parentp,
1126 					lbase, comp_block_size,
1127 					errorp);
1128 	ipdata = &ip->chain->data->ipdata;	/* RELOAD */
1129 
1130 	if (*errorp) {
1131 		kprintf("WRITE PATH: An error occurred while "
1132 			"assigning physical space.\n");
1133 		KKASSERT(chain == NULL);
1134 	} else {
1135 		/* Get device offset */
1136 		hammer2_io_t *dio;
1137 		char *bdata;
1138 		int temp_check;
1139 
1140 		KKASSERT(chain->flags & HAMMER2_CHAIN_MODIFIED);
1141 
1142 		switch(chain->bref.type) {
1143 		case HAMMER2_BREF_TYPE_INODE:
1144 			KKASSERT(chain->data->ipdata.op_flags &
1145 				 HAMMER2_OPFLAG_DIRECTDATA);
1146 			KKASSERT(bp->b_loffset == 0);
1147 			bcopy(bp->b_data, chain->data->ipdata.u.data,
1148 			      HAMMER2_EMBEDDED_BYTES);
1149 			break;
1150 		case HAMMER2_BREF_TYPE_DATA:
1151 			temp_check = HAMMER2_DEC_CHECK(chain->bref.methods);
1152 
1153 			/*
1154 			 * Optimize out the read-before-write
1155 			 * if possible.
1156 			 */
1157 			*errorp = hammer2_io_newnz(chain->hmp,
1158 						   chain->bref.data_off,
1159 						   chain->bytes,
1160 						   &dio);
1161 			if (*errorp) {
1162 				hammer2_io_brelse(&dio);
1163 				kprintf("hammer2: WRITE PATH: "
1164 					"dbp bread error\n");
1165 				break;
1166 			}
1167 			bdata = hammer2_io_data(dio, chain->bref.data_off);
1168 
1169 			/*
1170 			 * When loading the block make sure we don't
1171 			 * leave garbage after the compressed data.
1172 			 */
1173 			if (comp_size) {
1174 				chain->bref.methods =
1175 					HAMMER2_ENC_COMP(comp_algo) +
1176 					HAMMER2_ENC_CHECK(temp_check);
1177 				bcopy(comp_buffer, bdata, comp_size);
1178 				if (comp_size != comp_block_size) {
1179 					bzero(bdata + comp_size,
1180 					      comp_block_size - comp_size);
1181 				}
1182 			} else {
1183 				chain->bref.methods =
1184 					HAMMER2_ENC_COMP(
1185 						HAMMER2_COMP_NONE) +
1186 					HAMMER2_ENC_CHECK(temp_check);
1187 				bcopy(bp->b_data, bdata, pblksize);
1188 			}
1189 
1190 			/*
1191 			 * Device buffer is now valid, chain is no
1192 			 * longer in the initial state.
1193 			 */
1194 			atomic_clear_int(&chain->flags, HAMMER2_CHAIN_INITIAL);
1195 
1196 			/* Now write the related bdp. */
1197 			if (ioflag & IO_SYNC) {
1198 				/*
1199 				 * Synchronous I/O requested.
1200 				 */
1201 				hammer2_io_bwrite(&dio);
1202 			/*
1203 			} else if ((ioflag & IO_DIRECT) &&
1204 				   loff + n == pblksize) {
1205 				hammer2_io_bdwrite(&dio);
1206 			*/
1207 			} else if (ioflag & IO_ASYNC) {
1208 				hammer2_io_bawrite(&dio);
1209 			} else {
1210 				hammer2_io_bdwrite(&dio);
1211 			}
1212 			break;
1213 		default:
1214 			panic("hammer2_write_bp: bad chain type %d\n",
1215 				chain->bref.type);
1216 			/* NOT REACHED */
1217 			break;
1218 		}
1219 
1220 		hammer2_chain_unlock(chain);
1221 	}
1222 	if (comp_buffer)
1223 		objcache_put(cache_buffer_write, comp_buffer);
1224 }
1225 
1226 /*
1227  * Function that performs zero-checking and writing without compression,
1228  * it corresponds to default zero-checking path.
1229  */
1230 static
1231 void
1232 hammer2_zero_check_and_write(struct buf *bp, hammer2_trans_t *trans,
1233 	hammer2_inode_t *ip, hammer2_inode_data_t *ipdata,
1234 	hammer2_chain_t **parentp,
1235 	hammer2_key_t lbase, int ioflag, int pblksize, int *errorp)
1236 {
1237 	hammer2_chain_t *chain;
1238 
1239 	if (test_block_zeros(bp->b_data, pblksize)) {
1240 		zero_write(bp, trans, ip, ipdata, parentp, lbase, errorp);
1241 	} else {
1242 		chain = hammer2_assign_physical(trans, ip, parentp,
1243 						lbase, pblksize, errorp);
1244 		hammer2_write_bp(chain, bp, ioflag, pblksize, errorp);
1245 		if (chain)
1246 			hammer2_chain_unlock(chain);
1247 	}
1248 }
1249 
1250 /*
1251  * A function to test whether a block of data contains only zeros,
1252  * returns TRUE (non-zero) if the block is all zeros.
1253  */
1254 static
1255 int
1256 test_block_zeros(const char *buf, size_t bytes)
1257 {
1258 	size_t i;
1259 
1260 	for (i = 0; i < bytes; i += sizeof(long)) {
1261 		if (*(const long *)(buf + i) != 0)
1262 			return (0);
1263 	}
1264 	return (1);
1265 }
1266 
1267 /*
1268  * Function to "write" a block that contains only zeros.
1269  */
1270 static
1271 void
1272 zero_write(struct buf *bp, hammer2_trans_t *trans, hammer2_inode_t *ip,
1273 	hammer2_inode_data_t *ipdata, hammer2_chain_t **parentp,
1274 	hammer2_key_t lbase, int *errorp __unused)
1275 {
1276 	hammer2_chain_t *parent;
1277 	hammer2_chain_t *chain;
1278 	hammer2_key_t key_dummy;
1279 	int cache_index = -1;
1280 
1281 	parent = hammer2_chain_lookup_init(*parentp, 0);
1282 
1283 	chain = hammer2_chain_lookup(&parent, &key_dummy, lbase, lbase,
1284 				     &cache_index, HAMMER2_LOOKUP_NODATA);
1285 	if (chain) {
1286 		if (chain->bref.type == HAMMER2_BREF_TYPE_INODE) {
1287 			bzero(chain->data->ipdata.u.data,
1288 			      HAMMER2_EMBEDDED_BYTES);
1289 		} else {
1290 			hammer2_chain_delete(trans, chain, 0);
1291 		}
1292 		hammer2_chain_unlock(chain);
1293 	}
1294 	hammer2_chain_lookup_done(parent);
1295 }
1296 
1297 /*
1298  * Function to write the data as it is, without performing any sort of
1299  * compression. This function is used in path without compression and
1300  * default zero-checking path.
1301  */
1302 static
1303 void
1304 hammer2_write_bp(hammer2_chain_t *chain, struct buf *bp, int ioflag,
1305 				int pblksize, int *errorp)
1306 {
1307 	hammer2_io_t *dio;
1308 	char *bdata;
1309 	int error;
1310 	int temp_check = HAMMER2_DEC_CHECK(chain->bref.methods);
1311 
1312 	KKASSERT(chain->flags & HAMMER2_CHAIN_MODIFIED);
1313 
1314 	switch(chain->bref.type) {
1315 	case HAMMER2_BREF_TYPE_INODE:
1316 		KKASSERT(chain->data->ipdata.op_flags &
1317 			 HAMMER2_OPFLAG_DIRECTDATA);
1318 		KKASSERT(bp->b_loffset == 0);
1319 		bcopy(bp->b_data, chain->data->ipdata.u.data,
1320 		      HAMMER2_EMBEDDED_BYTES);
1321 		error = 0;
1322 		break;
1323 	case HAMMER2_BREF_TYPE_DATA:
1324 		error = hammer2_io_newnz(chain->hmp, chain->bref.data_off,
1325 					 chain->bytes, &dio);
1326 		if (error) {
1327 			hammer2_io_bqrelse(&dio);
1328 			kprintf("hammer2: WRITE PATH: dbp bread error\n");
1329 			break;
1330 		}
1331 		bdata = hammer2_io_data(dio, chain->bref.data_off);
1332 
1333 		chain->bref.methods = HAMMER2_ENC_COMP(HAMMER2_COMP_NONE) +
1334 				      HAMMER2_ENC_CHECK(temp_check);
1335 		bcopy(bp->b_data, bdata, chain->bytes);
1336 
1337 		/*
1338 		 * Device buffer is now valid, chain is no
1339 		 * longer in the initial state.
1340 		 */
1341 		atomic_clear_int(&chain->flags, HAMMER2_CHAIN_INITIAL);
1342 
1343 		if (ioflag & IO_SYNC) {
1344 			/*
1345 			 * Synchronous I/O requested.
1346 			 */
1347 			hammer2_io_bwrite(&dio);
1348 		/*
1349 		} else if ((ioflag & IO_DIRECT) && loff + n == pblksize) {
1350 			hammer2_io_bdwrite(&dio);
1351 		*/
1352 		} else if (ioflag & IO_ASYNC) {
1353 			hammer2_io_bawrite(&dio);
1354 		} else {
1355 			hammer2_io_bdwrite(&dio);
1356 		}
1357 		break;
1358 	default:
1359 		panic("hammer2_write_bp: bad chain type %d\n",
1360 		      chain->bref.type);
1361 		/* NOT REACHED */
1362 		error = 0;
1363 		break;
1364 	}
1365 	*errorp = error;
1366 }
1367 
1368 static
1369 int
1370 hammer2_remount(hammer2_mount_t *hmp, struct mount *mp, char *path,
1371 		struct vnode *devvp, struct ucred *cred)
1372 {
1373 	int error;
1374 
1375 	if (hmp->ronly && (mp->mnt_kern_flag & MNTK_WANTRDWR)) {
1376 		error = hammer2_recovery(hmp);
1377 	} else {
1378 		error = 0;
1379 	}
1380 	return error;
1381 }
1382 
1383 static
1384 int
1385 hammer2_vfs_unmount(struct mount *mp, int mntflags)
1386 {
1387 	hammer2_pfsmount_t *pmp;
1388 	hammer2_mount_t *hmp;
1389 	hammer2_chain_t *rchain;
1390 	int flags;
1391 	int error = 0;
1392 	int i;
1393 
1394 	pmp = MPTOPMP(mp);
1395 
1396 	if (pmp == NULL)
1397 		return(0);
1398 
1399 	ccms_domain_uninit(&pmp->ccms_dom);
1400 	kdmsg_iocom_uninit(&pmp->iocom);	/* XXX chain dependency */
1401 
1402 	lockmgr(&hammer2_mntlk, LK_EXCLUSIVE);
1403 
1404 	/*
1405 	 * If mount initialization proceeded far enough we must flush
1406 	 * its vnodes.
1407 	 */
1408 	if (mntflags & MNT_FORCE)
1409 		flags = FORCECLOSE;
1410 	else
1411 		flags = 0;
1412 	if (pmp->iroot) {
1413 		error = vflush(mp, 0, flags);
1414 		if (error)
1415 			goto failed;
1416 	}
1417 
1418 	if (pmp->wthread_td) {
1419 		mtx_lock(&pmp->wthread_mtx);
1420 		pmp->wthread_destroy = 1;
1421 		wakeup(&pmp->wthread_bioq);
1422 		while (pmp->wthread_destroy != -1) {
1423 			mtxsleep(&pmp->wthread_destroy,
1424 				&pmp->wthread_mtx, 0,
1425 				"umount-sleep",	0);
1426 		}
1427 		mtx_unlock(&pmp->wthread_mtx);
1428 		pmp->wthread_td = NULL;
1429 	}
1430 
1431 	for (i = 0; i < pmp->cluster.nchains; ++i) {
1432 		hmp = pmp->cluster.chains[i]->hmp;
1433 
1434 		hammer2_vfs_unmount_hmp1(mp, hmp);
1435 
1436 		/*
1437 		 * Cleanup the root and super-root chain elements
1438 		 * (which should be clean).
1439 		 */
1440 		if (pmp->iroot) {
1441 #if REPORT_REFS_ERRORS
1442 			if (pmp->iroot->refs != 1)
1443 				kprintf("PMP->IROOT %p REFS WRONG %d\n",
1444 					pmp->iroot, pmp->iroot->refs);
1445 #else
1446 			KKASSERT(pmp->iroot->refs == 1);
1447 #endif
1448 			/* ref for pmp->iroot */
1449 			hammer2_inode_drop(pmp->iroot);
1450 			pmp->iroot = NULL;
1451 		}
1452 
1453 		rchain = pmp->cluster.chains[i];
1454 		if (rchain) {
1455 			atomic_clear_int(&rchain->flags, HAMMER2_CHAIN_MOUNTED);
1456 #if REPORT_REFS_ERRORS
1457 			if (rchain->refs != 1)
1458 				kprintf("PMP->RCHAIN %p REFS WRONG %d\n",
1459 					rchain, rchain->refs);
1460 #else
1461 			KKASSERT(rchain->refs == 1);
1462 #endif
1463 			hammer2_chain_drop(rchain);
1464 			pmp->cluster.chains[i] = NULL;
1465 		}
1466 
1467 		hammer2_vfs_unmount_hmp2(mp, hmp);
1468 	}
1469 
1470 	pmp->mp = NULL;
1471 	mp->mnt_data = NULL;
1472 
1473 	kmalloc_destroy(&pmp->mmsg);
1474 	kmalloc_destroy(&pmp->minode);
1475 
1476 	kfree(pmp, M_HAMMER2);
1477 	error = 0;
1478 
1479 failed:
1480 	lockmgr(&hammer2_mntlk, LK_RELEASE);
1481 
1482 	return (error);
1483 }
1484 
1485 static
1486 void
1487 hammer2_vfs_unmount_hmp1(struct mount *mp, hammer2_mount_t *hmp)
1488 {
1489 	hammer2_mount_exlock(hmp);
1490 	--hmp->pmp_count;
1491 
1492 	kprintf("hammer2_unmount hmp=%p pmpcnt=%d\n", hmp, hmp->pmp_count);
1493 
1494 	/*
1495 	 * Flush any left over chains.  The voldata lock is only used
1496 	 * to synchronize against HAMMER2_CHAIN_MODIFIED_AUX.
1497 	 *
1498 	 * Flush twice to ensure that the freemap is completely
1499 	 * synchronized.  If we only do it once the next mount's
1500 	 * recovery scan will have to do some fixups (which isn't
1501 	 * bad, but we don't want it to have to do it except when
1502 	 * recovering from a crash).
1503 	 */
1504 	hammer2_voldata_lock(hmp);
1505 	if (((hmp->vchain.flags | hmp->fchain.flags) &
1506 	     HAMMER2_CHAIN_MODIFIED) ||
1507 	    hmp->vchain.core->update_hi > hmp->voldata.mirror_tid ||
1508 	    hmp->fchain.core->update_hi > hmp->voldata.freemap_tid) {
1509 		hammer2_voldata_unlock(hmp, 0);
1510 		hammer2_vfs_sync(mp, MNT_WAIT);
1511 		/*hammer2_vfs_sync(mp, MNT_WAIT);*/
1512 	} else {
1513 		hammer2_voldata_unlock(hmp, 0);
1514 	}
1515 	if (hmp->pmp_count == 0) {
1516 		if (((hmp->vchain.flags | hmp->fchain.flags) &
1517 		     HAMMER2_CHAIN_MODIFIED) ||
1518 		    (hmp->vchain.core->update_hi >
1519 		     hmp->voldata.mirror_tid) ||
1520 		    (hmp->fchain.core->update_hi >
1521 		     hmp->voldata.freemap_tid)) {
1522 			kprintf("hammer2_unmount: chains left over "
1523 				"after final sync\n");
1524 			kprintf("    vchain %08x update_hi %jx/%jx\n",
1525 				hmp->vchain.flags,
1526 				hmp->voldata.mirror_tid,
1527 				hmp->vchain.core->update_hi);
1528 			kprintf("    fchain %08x update_hi %jx/%jx\n",
1529 				hmp->fchain.flags,
1530 				hmp->voldata.freemap_tid,
1531 				hmp->fchain.core->update_hi);
1532 
1533 			if (hammer2_debug & 0x0010)
1534 				Debugger("entered debugger");
1535 		}
1536 	}
1537 }
1538 
1539 static
1540 void
1541 hammer2_vfs_unmount_hmp2(struct mount *mp, hammer2_mount_t *hmp)
1542 {
1543 	struct vnode *devvp;
1544 	int dumpcnt;
1545 	int ronly = ((mp->mnt_flag & MNT_RDONLY) != 0);
1546 
1547 	/*
1548 	 * If no PFS's left drop the master hammer2_mount for the
1549 	 * device.
1550 	 */
1551 	if (hmp->pmp_count == 0) {
1552 		if (hmp->sroot) {
1553 			hammer2_inode_drop(hmp->sroot);
1554 			hmp->sroot = NULL;
1555 		}
1556 
1557 		/*
1558 		 * Finish up with the device vnode
1559 		 */
1560 		if ((devvp = hmp->devvp) != NULL) {
1561 			vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
1562 			vinvalbuf(devvp, (ronly ? 0 : V_SAVE), 0, 0);
1563 			hmp->devvp = NULL;
1564 			VOP_CLOSE(devvp,
1565 				  (ronly ? FREAD : FREAD|FWRITE));
1566 			vn_unlock(devvp);
1567 			vrele(devvp);
1568 			devvp = NULL;
1569 		}
1570 
1571 		/*
1572 		 * Final drop of embedded freemap root chain to
1573 		 * clean up fchain.core (fchain structure is not
1574 		 * flagged ALLOCATED so it is cleaned out and then
1575 		 * left to rot).
1576 		 */
1577 		hammer2_chain_drop(&hmp->fchain);
1578 
1579 		/*
1580 		 * Final drop of embedded volume root chain to clean
1581 		 * up vchain.core (vchain structure is not flagged
1582 		 * ALLOCATED so it is cleaned out and then left to
1583 		 * rot).
1584 		 */
1585 		dumpcnt = 50;
1586 		hammer2_dump_chain(&hmp->vchain, 0, &dumpcnt);
1587 		dumpcnt = 50;
1588 		hammer2_dump_chain(&hmp->fchain, 0, &dumpcnt);
1589 		hammer2_mount_unlock(hmp);
1590 		hammer2_chain_drop(&hmp->vchain);
1591 
1592 		hammer2_io_cleanup(hmp, &hmp->iotree);
1593 		if (hmp->iofree_count) {
1594 			kprintf("io_cleanup: %d I/O's left hanging\n",
1595 				hmp->iofree_count);
1596 		}
1597 
1598 		TAILQ_REMOVE(&hammer2_mntlist, hmp, mntentry);
1599 		kmalloc_destroy(&hmp->mchain);
1600 		kfree(hmp, M_HAMMER2);
1601 	} else {
1602 		hammer2_mount_unlock(hmp);
1603 	}
1604 }
1605 
1606 static
1607 int
1608 hammer2_vfs_vget(struct mount *mp, struct vnode *dvp,
1609 	     ino_t ino, struct vnode **vpp)
1610 {
1611 	kprintf("hammer2_vget\n");
1612 	return (EOPNOTSUPP);
1613 }
1614 
1615 static
1616 int
1617 hammer2_vfs_root(struct mount *mp, struct vnode **vpp)
1618 {
1619 	hammer2_pfsmount_t *pmp;
1620 	hammer2_chain_t *parent;
1621 	int error;
1622 	struct vnode *vp;
1623 
1624 	pmp = MPTOPMP(mp);
1625 	if (pmp->iroot == NULL) {
1626 		*vpp = NULL;
1627 		error = EINVAL;
1628 	} else {
1629 		parent = hammer2_inode_lock_sh(pmp->iroot);
1630 		vp = hammer2_igetv(pmp->iroot, &error);
1631 		hammer2_inode_unlock_sh(pmp->iroot, parent);
1632 		*vpp = vp;
1633 		if (vp == NULL)
1634 			kprintf("vnodefail\n");
1635 	}
1636 
1637 	return (error);
1638 }
1639 
1640 /*
1641  * Filesystem status
1642  *
1643  * XXX incorporate ipdata->inode_quota and data_quota
1644  */
1645 static
1646 int
1647 hammer2_vfs_statfs(struct mount *mp, struct statfs *sbp, struct ucred *cred)
1648 {
1649 	hammer2_pfsmount_t *pmp;
1650 	hammer2_mount_t *hmp;
1651 
1652 	pmp = MPTOPMP(mp);
1653 	KKASSERT(pmp->cluster.nchains >= 1);
1654 	hmp = pmp->cluster.chains[0]->hmp;	/* XXX */
1655 
1656 	mp->mnt_stat.f_files = pmp->inode_count;
1657 	mp->mnt_stat.f_ffree = 0;
1658 	mp->mnt_stat.f_blocks = hmp->voldata.allocator_size / HAMMER2_PBUFSIZE;
1659 	mp->mnt_stat.f_bfree =  hmp->voldata.allocator_free / HAMMER2_PBUFSIZE;
1660 	mp->mnt_stat.f_bavail = mp->mnt_stat.f_bfree;
1661 
1662 	*sbp = mp->mnt_stat;
1663 	return (0);
1664 }
1665 
1666 static
1667 int
1668 hammer2_vfs_statvfs(struct mount *mp, struct statvfs *sbp, struct ucred *cred)
1669 {
1670 	hammer2_pfsmount_t *pmp;
1671 	hammer2_mount_t *hmp;
1672 
1673 	pmp = MPTOPMP(mp);
1674 	KKASSERT(pmp->cluster.nchains >= 1);
1675 	hmp = pmp->cluster.chains[0]->hmp;	/* XXX */
1676 
1677 	mp->mnt_vstat.f_bsize = HAMMER2_PBUFSIZE;
1678 	mp->mnt_vstat.f_files = pmp->inode_count;
1679 	mp->mnt_vstat.f_ffree = 0;
1680 	mp->mnt_vstat.f_blocks = hmp->voldata.allocator_size / HAMMER2_PBUFSIZE;
1681 	mp->mnt_vstat.f_bfree =  hmp->voldata.allocator_free / HAMMER2_PBUFSIZE;
1682 	mp->mnt_vstat.f_bavail = mp->mnt_vstat.f_bfree;
1683 
1684 	*sbp = mp->mnt_vstat;
1685 	return (0);
1686 }
1687 
1688 /*
1689  * Mount-time recovery (RW mounts)
1690  *
1691  * Updates to the free block table are allowed to lag flushes by one
1692  * transaction.  In case of a crash, then on a fresh mount we must do an
1693  * incremental scan of transaction id voldata.mirror_tid and make sure the
1694  * related blocks have been marked allocated.
1695  *
1696  */
1697 struct hammer2_recovery_elm {
1698 	TAILQ_ENTRY(hammer2_recovery_elm) entry;
1699 	hammer2_chain_t *chain;
1700 };
1701 
1702 TAILQ_HEAD(hammer2_recovery_list, hammer2_recovery_elm);
1703 
1704 static int hammer2_recovery_scan(hammer2_trans_t *trans, hammer2_mount_t *hmp,
1705 			hammer2_chain_t *parent,
1706 			struct hammer2_recovery_list *list, int depth);
1707 
1708 #define HAMMER2_RECOVERY_MAXDEPTH	10
1709 
1710 static
1711 int
1712 hammer2_recovery(hammer2_mount_t *hmp)
1713 {
1714 	hammer2_trans_t trans;
1715 	struct hammer2_recovery_list list;
1716 	struct hammer2_recovery_elm *elm;
1717 	hammer2_chain_t *parent;
1718 	int error;
1719 	int cumulative_error = 0;
1720 
1721 	hammer2_trans_init(&trans, NULL, hmp, 0);
1722 
1723 	TAILQ_INIT(&list);
1724 	parent = hammer2_chain_lookup_init(&hmp->vchain, 0);
1725 	cumulative_error = hammer2_recovery_scan(&trans, hmp, parent, &list, 0);
1726 	hammer2_chain_lookup_done(parent);
1727 
1728 	while ((elm = TAILQ_FIRST(&list)) != NULL) {
1729 		TAILQ_REMOVE(&list, elm, entry);
1730 		parent = elm->chain;
1731 		kfree(elm, M_HAMMER2);
1732 
1733 		hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS |
1734 					   HAMMER2_RESOLVE_NOREF);
1735 		error = hammer2_recovery_scan(&trans, hmp, parent, &list, 0);
1736 		hammer2_chain_unlock(parent);
1737 		if (error)
1738 			cumulative_error = error;
1739 	}
1740 	hammer2_trans_done(&trans);
1741 
1742 	return cumulative_error;
1743 }
1744 
1745 static
1746 int
1747 hammer2_recovery_scan(hammer2_trans_t *trans, hammer2_mount_t *hmp,
1748 		      hammer2_chain_t *parent,
1749 		      struct hammer2_recovery_list *list, int depth)
1750 {
1751 	hammer2_chain_t *chain;
1752 	int cache_index;
1753 	int cumulative_error = 0;
1754 	int error;
1755 
1756 	/*
1757 	 * Defer operation if depth limit reached.
1758 	 */
1759 	if (depth >= HAMMER2_RECOVERY_MAXDEPTH) {
1760 		struct hammer2_recovery_elm *elm;
1761 
1762 		elm = kmalloc(sizeof(*elm), M_HAMMER2, M_ZERO | M_WAITOK);
1763 		elm->chain = parent;
1764 		hammer2_chain_ref(parent);
1765 		TAILQ_INSERT_TAIL(list, elm, entry);
1766 		/* unlocked by caller */
1767 
1768 		return(0);
1769 	}
1770 
1771 	/*
1772 	 * Adjust freemap to ensure that the block(s) are marked allocated.
1773 	 */
1774 	if (parent->bref.type != HAMMER2_BREF_TYPE_VOLUME) {
1775 		hammer2_freemap_adjust(trans, hmp, &parent->bref,
1776 				       HAMMER2_FREEMAP_DORECOVER);
1777 	}
1778 
1779 	/*
1780 	 * Check type for recursive scan
1781 	 */
1782 	switch(parent->bref.type) {
1783 	case HAMMER2_BREF_TYPE_VOLUME:
1784 		/* data already instantiated */
1785 		break;
1786 	case HAMMER2_BREF_TYPE_INODE:
1787 		/*
1788 		 * Must instantiate data for DIRECTDATA test and also
1789 		 * for recursion.
1790 		 */
1791 		hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS);
1792 		hammer2_chain_unlock(parent);
1793 		if (parent->data->ipdata.op_flags & HAMMER2_OPFLAG_DIRECTDATA) {
1794 			/* not applicable to recovery scan */
1795 			return 0;
1796 		}
1797 		break;
1798 	case HAMMER2_BREF_TYPE_INDIRECT:
1799 		/*
1800 		 * Must instantiate data for recursion
1801 		 */
1802 		hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS);
1803 		hammer2_chain_unlock(parent);
1804 		break;
1805 	case HAMMER2_BREF_TYPE_DATA:
1806 	case HAMMER2_BREF_TYPE_FREEMAP:
1807 	case HAMMER2_BREF_TYPE_FREEMAP_NODE:
1808 	case HAMMER2_BREF_TYPE_FREEMAP_LEAF:
1809 		/* not applicable to recovery scan */
1810 		return 0;
1811 		break;
1812 	default:
1813 		return EDOM;
1814 	}
1815 
1816 	/*
1817 	 * Recursive scan of the last flushed transaction only.  We are
1818 	 * doing this without pmp assignments so don't leave the chains
1819 	 * hanging around after we are done with them.
1820 	 */
1821 	cache_index = 0;
1822 	chain = hammer2_chain_scan(parent, NULL, &cache_index,
1823 				   HAMMER2_LOOKUP_NODATA);
1824 	while (chain) {
1825 		atomic_set_int(&chain->flags, HAMMER2_CHAIN_RELEASE);
1826 		if (chain->bref.mirror_tid >= hmp->voldata.mirror_tid) {
1827 			error = hammer2_recovery_scan(trans, hmp, chain,
1828 						      list, depth + 1);
1829 			if (error)
1830 				cumulative_error = error;
1831 		}
1832 		chain = hammer2_chain_scan(parent, chain, &cache_index,
1833 					   HAMMER2_LOOKUP_NODATA);
1834 	}
1835 
1836 	return cumulative_error;
1837 }
1838 
1839 /*
1840  * Sync the entire filesystem; this is called from the filesystem syncer
1841  * process periodically and whenever a user calls sync(1) on the hammer
1842  * mountpoint.
1843  *
1844  * Currently is actually called from the syncer! \o/
1845  *
1846  * This task will have to snapshot the state of the dirty inode chain.
1847  * From that, it will have to make sure all of the inodes on the dirty
1848  * chain have IO initiated. We make sure that io is initiated for the root
1849  * block.
1850  *
1851  * If waitfor is set, we wait for media to acknowledge the new rootblock.
1852  *
1853  * THINKS: side A vs side B, to have sync not stall all I/O?
1854  */
1855 int
1856 hammer2_vfs_sync(struct mount *mp, int waitfor)
1857 {
1858 	struct hammer2_sync_info info;
1859 	hammer2_chain_t *chain;
1860 	hammer2_pfsmount_t *pmp;
1861 	hammer2_mount_t *hmp;
1862 	int flags;
1863 	int error;
1864 	int total_error;
1865 	int force_fchain;
1866 	int i;
1867 
1868 	pmp = MPTOPMP(mp);
1869 
1870 	/*
1871 	 * We can't acquire locks on existing vnodes while in a transaction
1872 	 * without risking a deadlock.  This assumes that vfsync() can be
1873 	 * called without the vnode locked (which it can in DragonFly).
1874 	 * Otherwise we'd have to implement a multi-pass or flag the lock
1875 	 * failures and retry.
1876 	 *
1877 	 * The reclamation code interlocks with the sync list's token
1878 	 * (by removing the vnode from the scan list) before unlocking
1879 	 * the inode, giving us time to ref the inode.
1880 	 */
1881 	/*flags = VMSC_GETVP;*/
1882 	flags = 0;
1883 	if (waitfor & MNT_LAZY)
1884 		flags |= VMSC_ONEPASS;
1885 
1886 	/*
1887 	 * Initialize a normal transaction and sync everything out, then
1888 	 * wait for pending I/O to finish (so it gets a transaction id
1889 	 * that the meta-data flush will catch).
1890 	 */
1891 	hammer2_trans_init(&info.trans, pmp, NULL, 0);
1892 	info.error = 0;
1893 	info.waitfor = MNT_NOWAIT;
1894 	vsyncscan(mp, flags | VMSC_NOWAIT, hammer2_sync_scan2, &info);
1895 
1896 	if (info.error == 0 && (waitfor & MNT_WAIT)) {
1897 		info.waitfor = waitfor;
1898 		    vsyncscan(mp, flags, hammer2_sync_scan2, &info);
1899 
1900 	}
1901 	hammer2_trans_done(&info.trans);
1902 	hammer2_bioq_sync(info.trans.pmp);
1903 
1904 	/*
1905 	 * Start the flush transaction and flush all meta-data.
1906 	 */
1907 	hammer2_trans_init(&info.trans, pmp, NULL, HAMMER2_TRANS_ISFLUSH);
1908 
1909 	total_error = 0;
1910 	for (i = 0; i < pmp->cluster.nchains; ++i) {
1911 		hmp = pmp->cluster.chains[i]->hmp;
1912 
1913 		/*
1914 		 * Media mounts have two 'roots', vchain for the topology
1915 		 * and fchain for the free block table.  Flush both.
1916 		 *
1917 		 * Note that the topology and free block table are handled
1918 		 * independently, so the free block table can wind up being
1919 		 * ahead of the topology.  We depend on the bulk free scan
1920 		 * code to deal with any loose ends.
1921 		 */
1922 #if 1
1923 		hammer2_chain_lock(&hmp->fchain, HAMMER2_RESOLVE_ALWAYS);
1924 		if ((hmp->fchain.flags & HAMMER2_CHAIN_MODIFIED) ||
1925 		    hmp->fchain.core->update_hi > hmp->voldata.freemap_tid) {
1926 			/* this will also modify vchain as a side effect */
1927 			chain = &hmp->fchain;
1928 			hammer2_chain_flush(&info.trans, &chain);
1929 			KKASSERT(chain == &hmp->fchain);
1930 		}
1931 		hammer2_chain_unlock(&hmp->fchain);
1932 #endif
1933 
1934 		hammer2_chain_lock(&hmp->vchain, HAMMER2_RESOLVE_ALWAYS);
1935 		if ((hmp->vchain.flags & HAMMER2_CHAIN_MODIFIED) ||
1936 		    hmp->vchain.core->update_hi > hmp->voldata.mirror_tid) {
1937 			chain = &hmp->vchain;
1938 			hammer2_chain_flush(&info.trans, &chain);
1939 			KKASSERT(chain == &hmp->vchain);
1940 			force_fchain = 1;
1941 		} else {
1942 			force_fchain = 0;
1943 		}
1944 		hammer2_chain_unlock(&hmp->vchain);
1945 
1946 #if 0
1947 		hammer2_chain_lock(&hmp->fchain, HAMMER2_RESOLVE_ALWAYS);
1948 		if ((hmp->fchain.flags & HAMMER2_CHAIN_MODIFIED) ||
1949 		    hmp->fchain.core->update_hi > hmp->voldata.freemap_tid ||
1950 		    force_fchain) {
1951 			/* this will also modify vchain as a side effect */
1952 			chain = &hmp->fchain;
1953 			hammer2_chain_flush(&info.trans, &chain);
1954 			KKASSERT(chain == &hmp->fchain);
1955 		}
1956 		hammer2_chain_unlock(&hmp->fchain);
1957 #endif
1958 
1959 		error = 0;
1960 
1961 		/*
1962 		 * We can't safely flush the volume header until we have
1963 		 * flushed any device buffers which have built up.
1964 		 *
1965 		 * XXX this isn't being incremental
1966 		 */
1967 		vn_lock(hmp->devvp, LK_EXCLUSIVE | LK_RETRY);
1968 		error = VOP_FSYNC(hmp->devvp, MNT_WAIT, 0);
1969 		vn_unlock(hmp->devvp);
1970 
1971 		/*
1972 		 * The flush code sets CHAIN_VOLUMESYNC to indicate that the
1973 		 * volume header needs synchronization via hmp->volsync.
1974 		 *
1975 		 * XXX synchronize the flag & data with only this flush XXX
1976 		 */
1977 		if (error == 0 &&
1978 		    (hmp->vchain.flags & HAMMER2_CHAIN_VOLUMESYNC)) {
1979 			struct buf *bp;
1980 
1981 			/*
1982 			 * Synchronize the disk before flushing the volume
1983 			 * header.
1984 			 */
1985 			bp = getpbuf(NULL);
1986 			bp->b_bio1.bio_offset = 0;
1987 			bp->b_bufsize = 0;
1988 			bp->b_bcount = 0;
1989 			bp->b_cmd = BUF_CMD_FLUSH;
1990 			bp->b_bio1.bio_done = biodone_sync;
1991 			bp->b_bio1.bio_flags |= BIO_SYNC;
1992 			vn_strategy(hmp->devvp, &bp->b_bio1);
1993 			biowait(&bp->b_bio1, "h2vol");
1994 			relpbuf(bp, NULL);
1995 
1996 			/*
1997 			 * Then we can safely flush the version of the
1998 			 * volume header synchronized by the flush code.
1999 			 */
2000 			i = hmp->volhdrno + 1;
2001 			if (i >= HAMMER2_NUM_VOLHDRS)
2002 				i = 0;
2003 			if (i * HAMMER2_ZONE_BYTES64 + HAMMER2_SEGSIZE >
2004 			    hmp->volsync.volu_size) {
2005 				i = 0;
2006 			}
2007 			kprintf("sync volhdr %d %jd\n",
2008 				i, (intmax_t)hmp->volsync.volu_size);
2009 			bp = getblk(hmp->devvp, i * HAMMER2_ZONE_BYTES64,
2010 				    HAMMER2_PBUFSIZE, 0, 0);
2011 			atomic_clear_int(&hmp->vchain.flags,
2012 					 HAMMER2_CHAIN_VOLUMESYNC);
2013 			bcopy(&hmp->volsync, bp->b_data, HAMMER2_PBUFSIZE);
2014 			bawrite(bp);
2015 			hmp->volhdrno = i;
2016 		}
2017 		if (error)
2018 			total_error = error;
2019 	}
2020 	hammer2_trans_done(&info.trans);
2021 
2022 	return (total_error);
2023 }
2024 
2025 /*
2026  * Sync passes.
2027  *
2028  * NOTE: We don't test update_lo/update_hi or MOVED here because the fsync
2029  *	 code won't flush on those flags.  The syncer code above will do a
2030  *	 general meta-data flush globally that will catch these flags.
2031  */
2032 
2033 static int
2034 hammer2_sync_scan2(struct mount *mp, struct vnode *vp, void *data)
2035 {
2036 	struct hammer2_sync_info *info = data;
2037 	hammer2_inode_t *ip;
2038 	int error;
2039 
2040 	/*
2041 	 *
2042 	 */
2043 	ip = VTOI(vp);
2044 	if (ip == NULL)
2045 		return(0);
2046 	if (vp->v_type == VNON || vp->v_type == VBAD) {
2047 		vclrisdirty(vp);
2048 		return(0);
2049 	}
2050 	if ((ip->flags & HAMMER2_INODE_MODIFIED) == 0 &&
2051 	    RB_EMPTY(&vp->v_rbdirty_tree)) {
2052 		vclrisdirty(vp);
2053 		return(0);
2054 	}
2055 
2056 	/*
2057 	 * VOP_FSYNC will start a new transaction so replicate some code
2058 	 * here to do it inline (see hammer2_vop_fsync()).
2059 	 *
2060 	 * WARNING: The vfsync interacts with the buffer cache and might
2061 	 *          block, we can't hold the inode lock at that time.
2062 	 *	    However, we MUST ref ip before blocking to ensure that
2063 	 *	    it isn't ripped out from under us (since we do not
2064 	 *	    hold a lock on the vnode).
2065 	 */
2066 	hammer2_inode_ref(ip);
2067 	atomic_clear_int(&ip->flags, HAMMER2_INODE_MODIFIED);
2068 	if (vp)
2069 		vfsync(vp, MNT_NOWAIT, 1, NULL, NULL);
2070 
2071 #if 0
2072 	/*
2073 	 * XXX this interferes with flush operations mainly because the
2074 	 *     same transaction id is being used by asynchronous buffer
2075 	 *     operations above and can be reordered after the flush
2076 	 *     below.
2077 	 */
2078 	parent = hammer2_inode_lock_ex(ip);
2079 	hammer2_chain_flush(&info->trans, &parent);
2080 	hammer2_inode_unlock_ex(ip, parent);
2081 #endif
2082 	hammer2_inode_drop(ip);
2083 	error = 0;
2084 #if 0
2085 	error = VOP_FSYNC(vp, MNT_NOWAIT, 0);
2086 #endif
2087 	if (error)
2088 		info->error = error;
2089 	return(0);
2090 }
2091 
2092 static
2093 int
2094 hammer2_vfs_vptofh(struct vnode *vp, struct fid *fhp)
2095 {
2096 	return (0);
2097 }
2098 
2099 static
2100 int
2101 hammer2_vfs_fhtovp(struct mount *mp, struct vnode *rootvp,
2102 	       struct fid *fhp, struct vnode **vpp)
2103 {
2104 	return (0);
2105 }
2106 
2107 static
2108 int
2109 hammer2_vfs_checkexp(struct mount *mp, struct sockaddr *nam,
2110 		 int *exflagsp, struct ucred **credanonp)
2111 {
2112 	return (0);
2113 }
2114 
2115 /*
2116  * Support code for hammer2_mount().  Read, verify, and install the volume
2117  * header into the HMP
2118  *
2119  * XXX read four volhdrs and use the one with the highest TID whos CRC
2120  *     matches.
2121  *
2122  * XXX check iCRCs.
2123  *
2124  * XXX For filesystems w/ less than 4 volhdrs, make sure to not write to
2125  *     nonexistant locations.
2126  *
2127  * XXX Record selected volhdr and ring updates to each of 4 volhdrs
2128  */
2129 static
2130 int
2131 hammer2_install_volume_header(hammer2_mount_t *hmp)
2132 {
2133 	hammer2_volume_data_t *vd;
2134 	struct buf *bp;
2135 	hammer2_crc32_t crc0, crc, bcrc0, bcrc;
2136 	int error_reported;
2137 	int error;
2138 	int valid;
2139 	int i;
2140 
2141 	error_reported = 0;
2142 	error = 0;
2143 	valid = 0;
2144 	bp = NULL;
2145 
2146 	/*
2147 	 * There are up to 4 copies of the volume header (syncs iterate
2148 	 * between them so there is no single master).  We don't trust the
2149 	 * volu_size field so we don't know precisely how large the filesystem
2150 	 * is, so depend on the OS to return an error if we go beyond the
2151 	 * block device's EOF.
2152 	 */
2153 	for (i = 0; i < HAMMER2_NUM_VOLHDRS; i++) {
2154 		error = bread(hmp->devvp, i * HAMMER2_ZONE_BYTES64,
2155 			      HAMMER2_VOLUME_BYTES, &bp);
2156 		if (error) {
2157 			brelse(bp);
2158 			bp = NULL;
2159 			continue;
2160 		}
2161 
2162 		vd = (struct hammer2_volume_data *) bp->b_data;
2163 		if ((vd->magic != HAMMER2_VOLUME_ID_HBO) &&
2164 		    (vd->magic != HAMMER2_VOLUME_ID_ABO)) {
2165 			brelse(bp);
2166 			bp = NULL;
2167 			continue;
2168 		}
2169 
2170 		if (vd->magic == HAMMER2_VOLUME_ID_ABO) {
2171 			/* XXX: Reversed-endianness filesystem */
2172 			kprintf("hammer2: reverse-endian filesystem detected");
2173 			brelse(bp);
2174 			bp = NULL;
2175 			continue;
2176 		}
2177 
2178 		crc = vd->icrc_sects[HAMMER2_VOL_ICRC_SECT0];
2179 		crc0 = hammer2_icrc32(bp->b_data + HAMMER2_VOLUME_ICRC0_OFF,
2180 				      HAMMER2_VOLUME_ICRC0_SIZE);
2181 		bcrc = vd->icrc_sects[HAMMER2_VOL_ICRC_SECT1];
2182 		bcrc0 = hammer2_icrc32(bp->b_data + HAMMER2_VOLUME_ICRC1_OFF,
2183 				       HAMMER2_VOLUME_ICRC1_SIZE);
2184 		if ((crc0 != crc) || (bcrc0 != bcrc)) {
2185 			kprintf("hammer2 volume header crc "
2186 				"mismatch copy #%d %08x/%08x\n",
2187 				i, crc0, crc);
2188 			error_reported = 1;
2189 			brelse(bp);
2190 			bp = NULL;
2191 			continue;
2192 		}
2193 		if (valid == 0 || hmp->voldata.mirror_tid < vd->mirror_tid) {
2194 			valid = 1;
2195 			hmp->voldata = *vd;
2196 			hmp->volhdrno = i;
2197 		}
2198 		brelse(bp);
2199 		bp = NULL;
2200 	}
2201 	if (valid) {
2202 		hmp->volsync = hmp->voldata;
2203 		error = 0;
2204 		if (error_reported || bootverbose || 1) { /* 1/DEBUG */
2205 			kprintf("hammer2: using volume header #%d\n",
2206 				hmp->volhdrno);
2207 		}
2208 	} else {
2209 		error = EINVAL;
2210 		kprintf("hammer2: no valid volume headers found!\n");
2211 	}
2212 	return (error);
2213 }
2214 
2215 /*
2216  * Reconnect using the passed file pointer.  The caller must ref the
2217  * fp for us.
2218  */
2219 void
2220 hammer2_cluster_reconnect(hammer2_pfsmount_t *pmp, struct file *fp)
2221 {
2222 	hammer2_inode_data_t *ipdata;
2223 	hammer2_chain_t *parent;
2224 	hammer2_mount_t *hmp;
2225 	size_t name_len;
2226 
2227 	hmp = pmp->cluster.chains[0]->hmp;	/* XXX */
2228 
2229 	/*
2230 	 * Closes old comm descriptor, kills threads, cleans up
2231 	 * states, then installs the new descriptor and creates
2232 	 * new threads.
2233 	 */
2234 	kdmsg_iocom_reconnect(&pmp->iocom, fp, "hammer2");
2235 
2236 	/*
2237 	 * Setup LNK_CONN fields for autoinitiated state machine
2238 	 */
2239 	parent = hammer2_inode_lock_ex(pmp->iroot);
2240 	ipdata = &parent->data->ipdata;
2241 	pmp->iocom.auto_lnk_conn.pfs_clid = ipdata->pfs_clid;
2242 	pmp->iocom.auto_lnk_conn.pfs_fsid = ipdata->pfs_fsid;
2243 	pmp->iocom.auto_lnk_conn.pfs_type = ipdata->pfs_type;
2244 	pmp->iocom.auto_lnk_conn.proto_version = DMSG_SPAN_PROTO_1;
2245 	pmp->iocom.auto_lnk_conn.peer_type = hmp->voldata.peer_type;
2246 
2247 	/*
2248 	 * Filter adjustment.  Clients do not need visibility into other
2249 	 * clients (otherwise millions of clients would present a serious
2250 	 * problem).  The fs_label also serves to restrict the namespace.
2251 	 */
2252 	pmp->iocom.auto_lnk_conn.peer_mask = 1LLU << HAMMER2_PEER_HAMMER2;
2253 	pmp->iocom.auto_lnk_conn.pfs_mask = (uint64_t)-1;
2254 	switch (ipdata->pfs_type) {
2255 	case DMSG_PFSTYPE_CLIENT:
2256 		pmp->iocom.auto_lnk_conn.peer_mask &=
2257 				~(1LLU << DMSG_PFSTYPE_CLIENT);
2258 		break;
2259 	default:
2260 		break;
2261 	}
2262 
2263 	name_len = ipdata->name_len;
2264 	if (name_len >= sizeof(pmp->iocom.auto_lnk_conn.fs_label))
2265 		name_len = sizeof(pmp->iocom.auto_lnk_conn.fs_label) - 1;
2266 	bcopy(ipdata->filename,
2267 	      pmp->iocom.auto_lnk_conn.fs_label,
2268 	      name_len);
2269 	pmp->iocom.auto_lnk_conn.fs_label[name_len] = 0;
2270 
2271 	/*
2272 	 * Setup LNK_SPAN fields for autoinitiated state machine
2273 	 */
2274 	pmp->iocom.auto_lnk_span.pfs_clid = ipdata->pfs_clid;
2275 	pmp->iocom.auto_lnk_span.pfs_fsid = ipdata->pfs_fsid;
2276 	pmp->iocom.auto_lnk_span.pfs_type = ipdata->pfs_type;
2277 	pmp->iocom.auto_lnk_span.peer_type = hmp->voldata.peer_type;
2278 	pmp->iocom.auto_lnk_span.proto_version = DMSG_SPAN_PROTO_1;
2279 	name_len = ipdata->name_len;
2280 	if (name_len >= sizeof(pmp->iocom.auto_lnk_span.fs_label))
2281 		name_len = sizeof(pmp->iocom.auto_lnk_span.fs_label) - 1;
2282 	bcopy(ipdata->filename,
2283 	      pmp->iocom.auto_lnk_span.fs_label,
2284 	      name_len);
2285 	pmp->iocom.auto_lnk_span.fs_label[name_len] = 0;
2286 	hammer2_inode_unlock_ex(pmp->iroot, parent);
2287 
2288 	kdmsg_iocom_autoinitiate(&pmp->iocom, hammer2_autodmsg);
2289 }
2290 
2291 static int
2292 hammer2_rcvdmsg(kdmsg_msg_t *msg)
2293 {
2294 	switch(msg->any.head.cmd & DMSGF_TRANSMASK) {
2295 	case DMSG_DBG_SHELL:
2296 		/*
2297 		 * (non-transaction)
2298 		 * Execute shell command (not supported atm)
2299 		 */
2300 		kdmsg_msg_reply(msg, DMSG_ERR_NOSUPP);
2301 		break;
2302 	case DMSG_DBG_SHELL | DMSGF_REPLY:
2303 		/*
2304 		 * (non-transaction)
2305 		 */
2306 		if (msg->aux_data) {
2307 			msg->aux_data[msg->aux_size - 1] = 0;
2308 			kprintf("HAMMER2 DBG: %s\n", msg->aux_data);
2309 		}
2310 		break;
2311 	default:
2312 		/*
2313 		 * Unsupported message received.  We only need to
2314 		 * reply if it's a transaction in order to close our end.
2315 		 * Ignore any one-way messages are any further messages
2316 		 * associated with the transaction.
2317 		 *
2318 		 * NOTE: This case also includes DMSG_LNK_ERROR messages
2319 		 *	 which might be one-way, replying to those would
2320 		 *	 cause an infinite ping-pong.
2321 		 */
2322 		if (msg->any.head.cmd & DMSGF_CREATE)
2323 			kdmsg_msg_reply(msg, DMSG_ERR_NOSUPP);
2324 		break;
2325 	}
2326 	return(0);
2327 }
2328 
2329 /*
2330  * This function is called after KDMSG has automatically handled processing
2331  * of a LNK layer message (typically CONN, SPAN, or CIRC).
2332  *
2333  * We tag off the LNK_CONN to trigger our LNK_VOLCONF messages which
2334  * advertises all available hammer2 super-root volumes.
2335  */
2336 static void
2337 hammer2_autodmsg(kdmsg_msg_t *msg)
2338 {
2339 	hammer2_pfsmount_t *pmp = msg->iocom->handle;
2340 	hammer2_mount_t *hmp = pmp->cluster.chains[0]->hmp; /* XXX */
2341 	int copyid;
2342 
2343 	/*
2344 	 * We only care about replies to our LNK_CONN auto-request.  kdmsg
2345 	 * has already processed the reply, we use this calback as a shim
2346 	 * to know when we can advertise available super-root volumes.
2347 	 */
2348 	if ((msg->any.head.cmd & DMSGF_TRANSMASK) !=
2349 	    (DMSG_LNK_CONN | DMSGF_CREATE | DMSGF_REPLY) ||
2350 	    msg->state == NULL) {
2351 		return;
2352 	}
2353 
2354 	kprintf("LNK_CONN REPLY RECEIVED CMD %08x\n", msg->any.head.cmd);
2355 
2356 	if (msg->any.head.cmd & DMSGF_CREATE) {
2357 		kprintf("HAMMER2: VOLDATA DUMP\n");
2358 
2359 		/*
2360 		 * Dump the configuration stored in the volume header
2361 		 */
2362 		hammer2_voldata_lock(hmp);
2363 		for (copyid = 0; copyid < HAMMER2_COPYID_COUNT; ++copyid) {
2364 			if (hmp->voldata.copyinfo[copyid].copyid == 0)
2365 				continue;
2366 			hammer2_volconf_update(pmp, copyid);
2367 		}
2368 		hammer2_voldata_unlock(hmp, 0);
2369 	}
2370 	if ((msg->any.head.cmd & DMSGF_DELETE) &&
2371 	    msg->state && (msg->state->txcmd & DMSGF_DELETE) == 0) {
2372 		kprintf("HAMMER2: CONN WAS TERMINATED\n");
2373 	}
2374 }
2375 
2376 /*
2377  * Volume configuration updates are passed onto the userland service
2378  * daemon via the open LNK_CONN transaction.
2379  */
2380 void
2381 hammer2_volconf_update(hammer2_pfsmount_t *pmp, int index)
2382 {
2383 	hammer2_mount_t *hmp = pmp->cluster.chains[0]->hmp;	/* XXX */
2384 	kdmsg_msg_t *msg;
2385 
2386 	/* XXX interlock against connection state termination */
2387 	kprintf("volconf update %p\n", pmp->iocom.conn_state);
2388 	if (pmp->iocom.conn_state) {
2389 		kprintf("TRANSMIT VOLCONF VIA OPEN CONN TRANSACTION\n");
2390 		msg = kdmsg_msg_alloc_state(pmp->iocom.conn_state,
2391 					    DMSG_LNK_VOLCONF, NULL, NULL);
2392 		msg->any.lnk_volconf.copy = hmp->voldata.copyinfo[index];
2393 		msg->any.lnk_volconf.mediaid = hmp->voldata.fsid;
2394 		msg->any.lnk_volconf.index = index;
2395 		kdmsg_msg_write(msg);
2396 	}
2397 }
2398 
2399 /*
2400  * This handles hysteresis on regular file flushes.  Because the BIOs are
2401  * routed to a thread it is possible for an excessive number to build up
2402  * and cause long front-end stalls long before the runningbuffspace limit
2403  * is hit, so we implement hammer2_flush_pipe to control the
2404  * hysteresis.
2405  *
2406  * This is a particular problem when compression is used.
2407  */
2408 void
2409 hammer2_lwinprog_ref(hammer2_pfsmount_t *pmp)
2410 {
2411 	atomic_add_int(&pmp->count_lwinprog, 1);
2412 }
2413 
2414 void
2415 hammer2_lwinprog_drop(hammer2_pfsmount_t *pmp)
2416 {
2417 	int lwinprog;
2418 
2419 	lwinprog = atomic_fetchadd_int(&pmp->count_lwinprog, -1);
2420 	if ((lwinprog & HAMMER2_LWINPROG_WAITING) &&
2421 	    (lwinprog & HAMMER2_LWINPROG_MASK) <= hammer2_flush_pipe * 2 / 3) {
2422 		atomic_clear_int(&pmp->count_lwinprog,
2423 				 HAMMER2_LWINPROG_WAITING);
2424 		wakeup(&pmp->count_lwinprog);
2425 	}
2426 }
2427 
2428 void
2429 hammer2_lwinprog_wait(hammer2_pfsmount_t *pmp)
2430 {
2431 	int lwinprog;
2432 
2433 	for (;;) {
2434 		lwinprog = pmp->count_lwinprog;
2435 		cpu_ccfence();
2436 		if ((lwinprog & HAMMER2_LWINPROG_MASK) < hammer2_flush_pipe)
2437 			break;
2438 		tsleep_interlock(&pmp->count_lwinprog, 0);
2439 		atomic_set_int(&pmp->count_lwinprog, HAMMER2_LWINPROG_WAITING);
2440 		lwinprog = pmp->count_lwinprog;
2441 		if ((lwinprog & HAMMER2_LWINPROG_MASK) < hammer2_flush_pipe)
2442 			break;
2443 		tsleep(&pmp->count_lwinprog, PINTERLOCKED, "h2wpipe", hz);
2444 	}
2445 }
2446 
2447 void
2448 hammer2_dump_chain(hammer2_chain_t *chain, int tab, int *countp)
2449 {
2450 	hammer2_chain_layer_t *layer;
2451 	hammer2_chain_t *scan;
2452 	hammer2_chain_t *first_parent;
2453 
2454 	--*countp;
2455 	if (*countp == 0) {
2456 		kprintf("%*.*s...\n", tab, tab, "");
2457 		return;
2458 	}
2459 	if (*countp < 0)
2460 		return;
2461 	first_parent = chain->core ? TAILQ_FIRST(&chain->core->ownerq) : NULL;
2462 	kprintf("%*.*schain %p.%d %016jx/%d mir=%016jx\n",
2463 		tab, tab, "",
2464 		chain, chain->bref.type,
2465 		chain->bref.key, chain->bref.keybits,
2466 		chain->bref.mirror_tid);
2467 
2468 	kprintf("%*.*s      [%08x] (%s) dt=%016jx refs=%d\n",
2469 		tab, tab, "",
2470 		chain->flags,
2471 		((chain->bref.type == HAMMER2_BREF_TYPE_INODE &&
2472 		chain->data) ?  (char *)chain->data->ipdata.filename : "?"),
2473 		chain->delete_tid,
2474 		chain->refs);
2475 
2476 	kprintf("%*.*s      core %p [%08x] lo=%08jx hi=%08jx fp=%p np=%p",
2477 		tab, tab, "",
2478 		chain->core, (chain->core ? chain->core->flags : 0),
2479 		(chain->core ? chain->core->update_lo : -1),
2480 		(chain->core ? chain->core->update_hi : -1),
2481 		first_parent,
2482 		(first_parent ? TAILQ_NEXT(chain, core_entry) : NULL));
2483 
2484 	if (first_parent)
2485 		kprintf(" [fpflags %08x fprefs %d\n",
2486 			first_parent->flags,
2487 			first_parent->refs);
2488 	if (chain->core == NULL || TAILQ_EMPTY(&chain->core->layerq))
2489 		kprintf("\n");
2490 	else
2491 		kprintf(" {\n");
2492 	if (chain->core) {
2493 		TAILQ_FOREACH(layer, &chain->core->layerq, entry) {
2494 			RB_FOREACH(scan, hammer2_chain_tree, &layer->rbtree) {
2495 				hammer2_dump_chain(scan, tab + 4, countp);
2496 			}
2497 		}
2498 	}
2499 	if (chain->core && !TAILQ_EMPTY(&chain->core->layerq)) {
2500 		if (chain->bref.type == HAMMER2_BREF_TYPE_INODE && chain->data)
2501 			kprintf("%*.*s}(%s)\n", tab, tab, "",
2502 				chain->data->ipdata.filename);
2503 		else
2504 			kprintf("%*.*s}\n", tab, tab, "");
2505 	}
2506 }
2507