xref: /dragonfly/sys/vfs/hammer/hammer_inode.c (revision f9602a12)
1 /*
2  * Copyright (c) 2007-2008 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  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  *
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in
15  *    the documentation and/or other materials provided with the
16  *    distribution.
17  * 3. Neither the name of The DragonFly Project nor the names of its
18  *    contributors may be used to endorse or promote products derived
19  *    from this software without specific, prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 #include <vm/vm_page2.h>
36 
37 #include "hammer.h"
38 
39 static int	hammer_unload_inode(struct hammer_inode *ip);
40 static void	hammer_free_inode(hammer_inode_t ip);
41 static void	hammer_flush_inode_core(hammer_inode_t ip,
42 					hammer_flush_group_t flg, int flags);
43 static int	hammer_setup_child_callback(hammer_record_t rec, void *data);
44 #if 0
45 static int	hammer_syncgrp_child_callback(hammer_record_t rec, void *data);
46 #endif
47 static int	hammer_setup_parent_inodes(hammer_inode_t ip, int depth,
48 					hammer_flush_group_t flg);
49 static int	hammer_setup_parent_inodes_helper(hammer_record_t record,
50 					int depth, hammer_flush_group_t flg);
51 static void	hammer_inode_wakereclaims(hammer_inode_t ip);
52 static struct hammer_inostats *hammer_inode_inostats(hammer_mount_t hmp,
53 					pid_t pid);
54 static struct hammer_inode *__hammer_find_inode(hammer_transaction_t trans,
55 					int64_t obj_id, hammer_tid_t asof,
56 					uint32_t localization);
57 
58 struct krate hammer_gen_krate = { 1 };
59 
60 /*
61  * RB-Tree support for inode structures
62  */
63 int
64 hammer_ino_rb_compare(hammer_inode_t ip1, hammer_inode_t ip2)
65 {
66 	if (ip1->obj_localization < ip2->obj_localization)
67 		return(-1);
68 	if (ip1->obj_localization > ip2->obj_localization)
69 		return(1);
70 	if (ip1->obj_id < ip2->obj_id)
71 		return(-1);
72 	if (ip1->obj_id > ip2->obj_id)
73 		return(1);
74 	if (ip1->obj_asof < ip2->obj_asof)
75 		return(-1);
76 	if (ip1->obj_asof > ip2->obj_asof)
77 		return(1);
78 	return(0);
79 }
80 
81 int
82 hammer_redo_rb_compare(hammer_inode_t ip1, hammer_inode_t ip2)
83 {
84 	if (ip1->redo_fifo_start < ip2->redo_fifo_start)
85 		return(-1);
86 	if (ip1->redo_fifo_start > ip2->redo_fifo_start)
87 		return(1);
88 	return(0);
89 }
90 
91 /*
92  * RB-Tree support for inode structures / special LOOKUP_INFO
93  */
94 static int
95 hammer_inode_info_cmp(hammer_inode_info_t info, hammer_inode_t ip)
96 {
97 	if (info->obj_localization < ip->obj_localization)
98 		return(-1);
99 	if (info->obj_localization > ip->obj_localization)
100 		return(1);
101 	if (info->obj_id < ip->obj_id)
102 		return(-1);
103 	if (info->obj_id > ip->obj_id)
104 		return(1);
105 	if (info->obj_asof < ip->obj_asof)
106 		return(-1);
107 	if (info->obj_asof > ip->obj_asof)
108 		return(1);
109 	return(0);
110 }
111 
112 /*
113  * Used by hammer_scan_inode_snapshots() to locate all of an object's
114  * snapshots.  Note that the asof field is not tested, which we can get
115  * away with because it is the lowest-priority field.
116  */
117 static int
118 hammer_inode_info_cmp_all_history(hammer_inode_t ip, void *data)
119 {
120 	hammer_inode_info_t info = data;
121 
122 	if (ip->obj_localization > info->obj_localization)
123 		return(1);
124 	if (ip->obj_localization < info->obj_localization)
125 		return(-1);
126 	if (ip->obj_id > info->obj_id)
127 		return(1);
128 	if (ip->obj_id < info->obj_id)
129 		return(-1);
130 	return(0);
131 }
132 
133 /*
134  * Used by hammer_unload_pseudofs() to locate all inodes associated with
135  * a particular PFS.
136  */
137 static int
138 hammer_inode_pfs_cmp(hammer_inode_t ip, void *data)
139 {
140 	uint32_t localization = *(uint32_t *)data;
141 	if (ip->obj_localization > localization)
142 		return(1);
143 	if (ip->obj_localization < localization)
144 		return(-1);
145 	return(0);
146 }
147 
148 /*
149  * RB-Tree support for pseudofs structures
150  */
151 static int
152 hammer_pfs_rb_compare(hammer_pseudofs_inmem_t p1, hammer_pseudofs_inmem_t p2)
153 {
154 	if (p1->localization < p2->localization)
155 		return(-1);
156 	if (p1->localization > p2->localization)
157 		return(1);
158 	return(0);
159 }
160 
161 
162 RB_GENERATE(hammer_ino_rb_tree, hammer_inode, rb_node, hammer_ino_rb_compare);
163 RB_GENERATE_XLOOKUP(hammer_ino_rb_tree, INFO, hammer_inode, rb_node,
164 		hammer_inode_info_cmp, hammer_inode_info_t);
165 RB_GENERATE2(hammer_pfs_rb_tree, hammer_pseudofs_inmem, rb_node,
166              hammer_pfs_rb_compare, uint32_t, localization);
167 
168 /*
169  * The kernel is not actively referencing this vnode but is still holding
170  * it cached.
171  *
172  * This is called from the frontend.
173  *
174  * MPALMOSTSAFE
175  */
176 int
177 hammer_vop_inactive(struct vop_inactive_args *ap)
178 {
179 	struct hammer_inode *ip = VTOI(ap->a_vp);
180 	hammer_mount_t hmp;
181 
182 	/*
183 	 * Degenerate case
184 	 */
185 	if (ip == NULL) {
186 		vrecycle(ap->a_vp);
187 		return(0);
188 	}
189 
190 	/*
191 	 * If the inode no longer has visibility in the filesystem try to
192 	 * recycle it immediately, even if the inode is dirty.  Recycling
193 	 * it quickly allows the system to reclaim buffer cache and VM
194 	 * resources which can matter a lot in a heavily loaded system.
195 	 *
196 	 * This can deadlock in vfsync() if we aren't careful.
197 	 *
198 	 * Do not queue the inode to the flusher if we still have visibility,
199 	 * otherwise namespace calls such as chmod will unnecessarily generate
200 	 * multiple inode updates.
201 	 */
202 	if (ip->ino_data.nlinks == 0) {
203 		hmp = ip->hmp;
204 		lwkt_gettoken(&hmp->fs_token);
205 		hammer_inode_unloadable_check(ip, 0);
206 		if (ip->flags & HAMMER_INODE_MODMASK)
207 			hammer_flush_inode(ip, 0);
208 		lwkt_reltoken(&hmp->fs_token);
209 		vrecycle(ap->a_vp);
210 	}
211 	return(0);
212 }
213 
214 /*
215  * Release the vnode association.  This is typically (but not always)
216  * the last reference on the inode.
217  *
218  * Once the association is lost we are on our own with regards to
219  * flushing the inode.
220  *
221  * We must interlock ip->vp so hammer_get_vnode() can avoid races.
222  */
223 int
224 hammer_vop_reclaim(struct vop_reclaim_args *ap)
225 {
226 	struct hammer_inode *ip;
227 	hammer_mount_t hmp;
228 	struct vnode *vp;
229 
230 	vp = ap->a_vp;
231 
232 	if ((ip = vp->v_data) != NULL) {
233 		hmp = ip->hmp;
234 		lwkt_gettoken(&hmp->fs_token);
235 		hammer_lock_ex(&ip->lock);
236 		vp->v_data = NULL;
237 		ip->vp = NULL;
238 
239 		if ((ip->flags & HAMMER_INODE_RECLAIM) == 0) {
240 			++hammer_count_reclaims;
241 			++hmp->count_reclaims;
242 			ip->flags |= HAMMER_INODE_RECLAIM;
243 		}
244 		hammer_unlock(&ip->lock);
245 		vclrisdirty(vp);
246 		hammer_rel_inode(ip, 1);
247 		lwkt_reltoken(&hmp->fs_token);
248 	}
249 	return(0);
250 }
251 
252 /*
253  * Inform the kernel that the inode is dirty.  This will be checked
254  * by vn_unlock().
255  *
256  * Theoretically in order to reclaim a vnode the hammer_vop_reclaim()
257  * must be called which will interlock against our inode lock, so
258  * if VRECLAIMED is not set vp->v_mount (as used by vsetisdirty())
259  * should be stable without having to acquire any new locks.
260  */
261 void
262 hammer_inode_dirty(struct hammer_inode *ip)
263 {
264 	struct vnode *vp;
265 
266 	if ((ip->flags & HAMMER_INODE_MODMASK) &&
267 	    (vp = ip->vp) != NULL &&
268 	    (vp->v_flag & (VRECLAIMED | VISDIRTY)) == 0) {
269 		vsetisdirty(vp);
270 	}
271 }
272 
273 /*
274  * Return a locked vnode for the specified inode.  The inode must be
275  * referenced but NOT LOCKED on entry and will remain referenced on
276  * return.
277  *
278  * Called from the frontend.
279  */
280 int
281 hammer_get_vnode(struct hammer_inode *ip, struct vnode **vpp)
282 {
283 	hammer_mount_t hmp;
284 	struct vnode *vp;
285 	int error = 0;
286 	uint8_t obj_type;
287 
288 	hmp = ip->hmp;
289 
290 	for (;;) {
291 		if ((vp = ip->vp) == NULL) {
292 			error = getnewvnode(VT_HAMMER, hmp->mp, vpp, 0, 0);
293 			if (error)
294 				break;
295 			hammer_lock_ex(&ip->lock);
296 			if (ip->vp != NULL) {
297 				hammer_unlock(&ip->lock);
298 				vp = *vpp;
299 				vp->v_type = VBAD;
300 				vx_put(vp);
301 				continue;
302 			}
303 			hammer_ref(&ip->lock);
304 			vp = *vpp;
305 			ip->vp = vp;
306 
307 			obj_type = ip->ino_data.obj_type;
308 			vp->v_type = hammer_get_vnode_type(obj_type);
309 
310 			hammer_inode_wakereclaims(ip);
311 
312 			switch(ip->ino_data.obj_type) {
313 			case HAMMER_OBJTYPE_CDEV:
314 			case HAMMER_OBJTYPE_BDEV:
315 				vp->v_ops = &hmp->mp->mnt_vn_spec_ops;
316 				addaliasu(vp, ip->ino_data.rmajor,
317 					  ip->ino_data.rminor);
318 				break;
319 			case HAMMER_OBJTYPE_FIFO:
320 				vp->v_ops = &hmp->mp->mnt_vn_fifo_ops;
321 				break;
322 			case HAMMER_OBJTYPE_REGFILE:
323 				break;
324 			default:
325 				break;
326 			}
327 
328 			/*
329 			 * Only mark as the root vnode if the ip is not
330 			 * historical, otherwise the VFS cache will get
331 			 * confused.  The other half of the special handling
332 			 * is in hammer_vop_nlookupdotdot().
333 			 *
334 			 * Pseudo-filesystem roots can be accessed via
335 			 * non-root filesystem paths and setting VROOT may
336 			 * confuse the namecache.  Set VPFSROOT instead.
337 			 */
338 			if (ip->obj_id == HAMMER_OBJID_ROOT) {
339 				if (ip->obj_asof == hmp->asof) {
340 					if (ip->obj_localization == 0)
341 						vsetflags(vp, VROOT);
342 					else
343 						vsetflags(vp, VPFSROOT);
344 				} else {
345 					vsetflags(vp, VPFSROOT);
346 				}
347 			}
348 
349 			vp->v_data = (void *)ip;
350 			/* vnode locked by getnewvnode() */
351 			/* make related vnode dirty if inode dirty? */
352 			hammer_unlock(&ip->lock);
353 			if (vp->v_type == VREG) {
354 				vinitvmio(vp, ip->ino_data.size,
355 					  hammer_blocksize(ip->ino_data.size),
356 					  hammer_blockoff(ip->ino_data.size));
357 			}
358 			break;
359 		}
360 
361 		/*
362 		 * Interlock vnode clearing.  This does not prevent the
363 		 * vnode from going into a reclaimed state but it does
364 		 * prevent it from being destroyed or reused so the vget()
365 		 * will properly fail.
366 		 */
367 		hammer_lock_ex(&ip->lock);
368 		if ((vp = ip->vp) == NULL) {
369 			hammer_unlock(&ip->lock);
370 			continue;
371 		}
372 		vhold(vp);
373 		hammer_unlock(&ip->lock);
374 
375 		/*
376 		 * loop if the vget fails (aka races), or if the vp
377 		 * no longer matches ip->vp.
378 		 */
379 		if (vget(vp, LK_EXCLUSIVE) == 0) {
380 			if (vp == ip->vp) {
381 				vdrop(vp);
382 				break;
383 			}
384 			vput(vp);
385 		}
386 		vdrop(vp);
387 	}
388 	*vpp = vp;
389 	return(error);
390 }
391 
392 /*
393  * Locate all copies of the inode for obj_id compatible with the specified
394  * asof, reference, and issue the related call-back.  This routine is used
395  * for direct-io invalidation and does not create any new inodes.
396  */
397 void
398 hammer_scan_inode_snapshots(hammer_mount_t hmp, hammer_inode_info_t iinfo,
399 		            int (*callback)(hammer_inode_t ip, void *data),
400 			    void *data)
401 {
402 	hammer_ino_rb_tree_RB_SCAN(&hmp->rb_inos_root,
403 				   hammer_inode_info_cmp_all_history,
404 				   callback, iinfo);
405 }
406 
407 /*
408  * Acquire a HAMMER inode.  The returned inode is not locked.  These functions
409  * do not attach or detach the related vnode (use hammer_get_vnode() for
410  * that).
411  *
412  * The flags argument is only applied for newly created inodes, and only
413  * certain flags are inherited.
414  *
415  * Called from the frontend.
416  */
417 struct hammer_inode *
418 hammer_get_inode(hammer_transaction_t trans, hammer_inode_t dip,
419 		 int64_t obj_id, hammer_tid_t asof, uint32_t localization,
420 		 int flags, int *errorp)
421 {
422 	hammer_mount_t hmp = trans->hmp;
423 	struct hammer_node_cache *cachep;
424 	struct hammer_cursor cursor;
425 	struct hammer_inode *ip;
426 
427 
428 	/*
429 	 * Determine if we already have an inode cached.  If we do then
430 	 * we are golden.
431 	 *
432 	 * If we find an inode with no vnode we have to mark the
433 	 * transaction such that hammer_inode_waitreclaims() is
434 	 * called later on to avoid building up an infinite number
435 	 * of inodes.  Otherwise we can continue to * add new inodes
436 	 * faster then they can be disposed of, even with the tsleep
437 	 * delay.
438 	 *
439 	 * If we find a dummy inode we return a failure so dounlink
440 	 * (which does another lookup) doesn't try to mess with the
441 	 * link count.  hammer_vop_nresolve() uses hammer_get_dummy_inode()
442 	 * to ref dummy inodes.
443 	 */
444 loop:
445 	*errorp = 0;
446 	ip = __hammer_find_inode(trans, obj_id, asof, localization);
447 	if (ip) {
448 		if (ip->flags & HAMMER_INODE_DUMMY) {
449 			*errorp = ENOENT;
450 			return(NULL);
451 		}
452 		hammer_ref(&ip->lock);
453 		return(ip);
454 	}
455 
456 	/*
457 	 * Allocate a new inode structure and deal with races later.
458 	 */
459 	ip = kmalloc(sizeof(*ip), hmp->m_inodes, M_WAITOK|M_ZERO);
460 	++hammer_count_inodes;
461 	++hmp->count_inodes;
462 	ip->obj_id = obj_id;
463 	ip->obj_asof = asof;
464 	ip->obj_localization = localization;
465 	ip->hmp = hmp;
466 	ip->flags = flags & HAMMER_INODE_RO;
467 	ip->cache[0].ip = ip;
468 	ip->cache[1].ip = ip;
469 	ip->cache[2].ip = ip;
470 	ip->cache[3].ip = ip;
471 	if (hmp->ronly)
472 		ip->flags |= HAMMER_INODE_RO;
473 	ip->sync_trunc_off = ip->trunc_off = ip->save_trunc_off =
474 		0x7FFFFFFFFFFFFFFFLL;
475 	RB_INIT(&ip->rec_tree);
476 	TAILQ_INIT(&ip->target_list);
477 	hammer_ref(&ip->lock);
478 
479 	/*
480 	 * Locate the on-disk inode.  If this is a PFS root we always
481 	 * access the current version of the root inode and (if it is not
482 	 * a master) always access information under it with a snapshot
483 	 * TID.
484 	 *
485 	 * We cache recent inode lookups in this directory in dip->cache[2].
486 	 * If we can't find it we assume the inode we are looking for is
487 	 * close to the directory inode.
488 	 */
489 retry:
490 	cachep = NULL;
491 	if (dip) {
492 		if (dip->cache[2].node)
493 			cachep = &dip->cache[2];
494 		else
495 			cachep = &dip->cache[0];
496 	}
497 	hammer_init_cursor(trans, &cursor, cachep, NULL);
498 	cursor.key_beg.localization = localization | HAMMER_LOCALIZE_INODE;
499 	cursor.key_beg.obj_id = ip->obj_id;
500 	cursor.key_beg.key = 0;
501 	cursor.key_beg.create_tid = 0;
502 	cursor.key_beg.delete_tid = 0;
503 	cursor.key_beg.rec_type = HAMMER_RECTYPE_INODE;
504 	cursor.key_beg.obj_type = 0;
505 
506 	cursor.asof = asof;
507 	cursor.flags = HAMMER_CURSOR_GET_LEAF | HAMMER_CURSOR_GET_DATA |
508 		       HAMMER_CURSOR_ASOF;
509 
510 	*errorp = hammer_btree_lookup(&cursor);
511 	if (*errorp == EDEADLK) {
512 		hammer_done_cursor(&cursor);
513 		goto retry;
514 	}
515 
516 	/*
517 	 * On success the B-Tree lookup will hold the appropriate
518 	 * buffer cache buffers and provide a pointer to the requested
519 	 * information.  Copy the information to the in-memory inode
520 	 * and cache the B-Tree node to improve future operations.
521 	 */
522 	if (*errorp == 0) {
523 		ip->ino_leaf = cursor.node->ondisk->elms[cursor.index].leaf;
524 		ip->ino_data = cursor.data->inode;
525 
526 		/*
527 		 * cache[0] tries to cache the location of the object inode.
528 		 * The assumption is that it is near the directory inode.
529 		 *
530 		 * cache[1] tries to cache the location of the object data.
531 		 * We might have something in the governing directory from
532 		 * scan optimizations (see the strategy code in
533 		 * hammer_vnops.c).
534 		 *
535 		 * We update dip->cache[2], if possible, with the location
536 		 * of the object inode for future directory shortcuts.
537 		 */
538 		hammer_cache_node(&ip->cache[0], cursor.node);
539 		if (dip) {
540 			if (dip->cache[3].node) {
541 				hammer_cache_node(&ip->cache[1],
542 						  dip->cache[3].node);
543 			}
544 			hammer_cache_node(&dip->cache[2], cursor.node);
545 		}
546 
547 		/*
548 		 * The file should not contain any data past the file size
549 		 * stored in the inode.  Setting save_trunc_off to the
550 		 * file size instead of max reduces B-Tree lookup overheads
551 		 * on append by allowing the flusher to avoid checking for
552 		 * record overwrites.
553 		 */
554 		ip->save_trunc_off = ip->ino_data.size;
555 
556 		/*
557 		 * Locate and assign the pseudofs management structure to
558 		 * the inode.
559 		 */
560 		if (dip && dip->obj_localization == ip->obj_localization) {
561 			ip->pfsm = dip->pfsm;
562 			hammer_ref(&ip->pfsm->lock);
563 		} else {
564 			ip->pfsm = hammer_load_pseudofs(trans,
565 							ip->obj_localization,
566 							errorp);
567 			*errorp = 0;	/* ignore ENOENT */
568 		}
569 	}
570 
571 	/*
572 	 * The inode is placed on the red-black tree and will be synced to
573 	 * the media when flushed or by the filesystem sync.  If this races
574 	 * another instantiation/lookup the insertion will fail.
575 	 */
576 	if (*errorp == 0) {
577 		if (RB_INSERT(hammer_ino_rb_tree, &hmp->rb_inos_root, ip)) {
578 			hammer_free_inode(ip);
579 			hammer_done_cursor(&cursor);
580 			goto loop;
581 		}
582 		ip->flags |= HAMMER_INODE_ONDISK;
583 	} else {
584 		if (ip->flags & HAMMER_INODE_RSV_INODES) {
585 			ip->flags &= ~HAMMER_INODE_RSV_INODES; /* sanity */
586 			--hmp->rsv_inodes;
587 		}
588 
589 		hammer_free_inode(ip);
590 		ip = NULL;
591 	}
592 	hammer_done_cursor(&cursor);
593 
594 	/*
595 	 * NEWINODE is only set if the inode becomes dirty later,
596 	 * setting it here just leads to unnecessary stalls.
597 	 *
598 	 * trans->flags |= HAMMER_TRANSF_NEWINODE;
599 	 */
600 	return (ip);
601 }
602 
603 /*
604  * Get a dummy inode to placemark a broken directory entry.
605  */
606 struct hammer_inode *
607 hammer_get_dummy_inode(hammer_transaction_t trans, hammer_inode_t dip,
608 		 int64_t obj_id, hammer_tid_t asof, uint32_t localization,
609 		 int flags, int *errorp)
610 {
611 	hammer_mount_t hmp = trans->hmp;
612 	struct hammer_inode *ip;
613 
614 	/*
615 	 * Determine if we already have an inode cached.  If we do then
616 	 * we are golden.
617 	 *
618 	 * If we find an inode with no vnode we have to mark the
619 	 * transaction such that hammer_inode_waitreclaims() is
620 	 * called later on to avoid building up an infinite number
621 	 * of inodes.  Otherwise we can continue to * add new inodes
622 	 * faster then they can be disposed of, even with the tsleep
623 	 * delay.
624 	 *
625 	 * If we find a non-fake inode we return an error.  Only fake
626 	 * inodes can be returned by this routine.
627 	 */
628 loop:
629 	*errorp = 0;
630 	ip = __hammer_find_inode(trans, obj_id, asof, localization);
631 	if (ip) {
632 		if ((ip->flags & HAMMER_INODE_DUMMY) == 0) {
633 			*errorp = ENOENT;
634 			return(NULL);
635 		}
636 		hammer_ref(&ip->lock);
637 		return(ip);
638 	}
639 
640 	/*
641 	 * Allocate a new inode structure and deal with races later.
642 	 */
643 	ip = kmalloc(sizeof(*ip), hmp->m_inodes, M_WAITOK|M_ZERO);
644 	++hammer_count_inodes;
645 	++hmp->count_inodes;
646 	ip->obj_id = obj_id;
647 	ip->obj_asof = asof;
648 	ip->obj_localization = localization;
649 	ip->hmp = hmp;
650 	ip->flags = flags | HAMMER_INODE_RO | HAMMER_INODE_DUMMY;
651 	ip->cache[0].ip = ip;
652 	ip->cache[1].ip = ip;
653 	ip->cache[2].ip = ip;
654 	ip->cache[3].ip = ip;
655 	ip->sync_trunc_off = ip->trunc_off = ip->save_trunc_off =
656 		0x7FFFFFFFFFFFFFFFLL;
657 	RB_INIT(&ip->rec_tree);
658 	TAILQ_INIT(&ip->target_list);
659 	hammer_ref(&ip->lock);
660 
661 	/*
662 	 * Populate the dummy inode.  Leave everything zero'd out.
663 	 *
664 	 * (ip->ino_leaf and ip->ino_data)
665 	 *
666 	 * Make the dummy inode a FIFO object which most copy programs
667 	 * will properly ignore.
668 	 */
669 	ip->save_trunc_off = ip->ino_data.size;
670 	ip->ino_data.obj_type = HAMMER_OBJTYPE_FIFO;
671 
672 	/*
673 	 * Locate and assign the pseudofs management structure to
674 	 * the inode.
675 	 */
676 	if (dip && dip->obj_localization == ip->obj_localization) {
677 		ip->pfsm = dip->pfsm;
678 		hammer_ref(&ip->pfsm->lock);
679 	} else {
680 		ip->pfsm = hammer_load_pseudofs(trans, ip->obj_localization,
681 						errorp);
682 		*errorp = 0;	/* ignore ENOENT */
683 	}
684 
685 	/*
686 	 * The inode is placed on the red-black tree and will be synced to
687 	 * the media when flushed or by the filesystem sync.  If this races
688 	 * another instantiation/lookup the insertion will fail.
689 	 *
690 	 * NOTE: Do not set HAMMER_INODE_ONDISK.  The inode is a fake.
691 	 */
692 	if (*errorp == 0) {
693 		if (RB_INSERT(hammer_ino_rb_tree, &hmp->rb_inos_root, ip)) {
694 			hammer_free_inode(ip);
695 			goto loop;
696 		}
697 	} else {
698 		if (ip->flags & HAMMER_INODE_RSV_INODES) {
699 			ip->flags &= ~HAMMER_INODE_RSV_INODES; /* sanity */
700 			--hmp->rsv_inodes;
701 		}
702 		hammer_free_inode(ip);
703 		ip = NULL;
704 	}
705 	trans->flags |= HAMMER_TRANSF_NEWINODE;
706 	return (ip);
707 }
708 
709 /*
710  * Return a referenced inode only if it is in our inode cache.
711  * Dummy inodes do not count.
712  */
713 struct hammer_inode *
714 hammer_find_inode(hammer_transaction_t trans, int64_t obj_id,
715 		  hammer_tid_t asof, uint32_t localization)
716 {
717 	struct hammer_inode *ip;
718 
719 	ip = __hammer_find_inode(trans, obj_id, asof, localization);
720 	if (ip) {
721 		if (ip->flags & HAMMER_INODE_DUMMY)
722 			ip = NULL;
723 		else
724 			hammer_ref(&ip->lock);
725 	}
726 	return(ip);
727 }
728 
729 /*
730  * Return a referenced inode only if it is in our inode cache.
731  * This function does not reference inode.
732  */
733 static struct hammer_inode *
734 __hammer_find_inode(hammer_transaction_t trans, int64_t obj_id,
735 		  hammer_tid_t asof, uint32_t localization)
736 {
737 	hammer_mount_t hmp = trans->hmp;
738 	struct hammer_inode_info iinfo;
739 	struct hammer_inode *ip;
740 
741 	iinfo.obj_id = obj_id;
742 	iinfo.obj_asof = asof;
743 	iinfo.obj_localization = localization;
744 
745 	ip = hammer_ino_rb_tree_RB_LOOKUP_INFO(&hmp->rb_inos_root, &iinfo);
746 
747 	return(ip);
748 }
749 
750 /*
751  * Create a new filesystem object, returning the inode in *ipp.  The
752  * returned inode will be referenced.  The inode is created in-memory.
753  *
754  * If pfsm is non-NULL the caller wishes to create the root inode for
755  * a master PFS.
756  */
757 int
758 hammer_create_inode(hammer_transaction_t trans, struct vattr *vap,
759 		    struct ucred *cred,
760 		    hammer_inode_t dip, const char *name, int namelen,
761 		    hammer_pseudofs_inmem_t pfsm, struct hammer_inode **ipp)
762 {
763 	hammer_mount_t hmp;
764 	hammer_inode_t ip;
765 	uid_t xuid;
766 	int error;
767 	int64_t namekey;
768 	uint32_t dummy;
769 
770 	hmp = trans->hmp;
771 
772 	/*
773 	 * Disallow the creation of new inodes in directories which
774 	 * have been deleted.  In HAMMER, this will cause a record
775 	 * syncing assertion later on in the flush code.
776 	 */
777 	if (dip && dip->ino_data.nlinks == 0) {
778 		*ipp = NULL;
779                 return (EINVAL);
780 	}
781 
782 	/*
783 	 * Allocate inode
784 	 */
785 	ip = kmalloc(sizeof(*ip), hmp->m_inodes, M_WAITOK|M_ZERO);
786 	++hammer_count_inodes;
787 	++hmp->count_inodes;
788 	trans->flags |= HAMMER_TRANSF_NEWINODE;
789 
790 	if (pfsm) {
791 		KKASSERT(pfsm->localization != 0);
792 		ip->obj_id = HAMMER_OBJID_ROOT;
793 		ip->obj_localization = pfsm->localization;
794 	} else {
795 		KKASSERT(dip != NULL);
796 		namekey = hammer_directory_namekey(dip, name, namelen, &dummy);
797 		ip->obj_id = hammer_alloc_objid(hmp, dip, namekey);
798 		ip->obj_localization = dip->obj_localization;
799 	}
800 
801 	KKASSERT(ip->obj_id != 0);
802 	ip->obj_asof = hmp->asof;
803 	ip->hmp = hmp;
804 	ip->flush_state = HAMMER_FST_IDLE;
805 	ip->flags = HAMMER_INODE_DDIRTY |
806 		    HAMMER_INODE_ATIME | HAMMER_INODE_MTIME;
807 	ip->cache[0].ip = ip;
808 	ip->cache[1].ip = ip;
809 	ip->cache[2].ip = ip;
810 	ip->cache[3].ip = ip;
811 
812 	ip->trunc_off = 0x7FFFFFFFFFFFFFFFLL;
813 	/* ip->save_trunc_off = 0; (already zero) */
814 	RB_INIT(&ip->rec_tree);
815 	TAILQ_INIT(&ip->target_list);
816 
817 	ip->ino_data.atime = trans->time;
818 	ip->ino_data.mtime = trans->time;
819 	ip->ino_data.size = 0;
820 	ip->ino_data.nlinks = 0;
821 
822 	/*
823 	 * A nohistory designator on the parent directory is inherited by
824 	 * the child.  We will do this even for pseudo-fs creation... the
825 	 * sysad can turn it off.
826 	 */
827 	if (dip) {
828 		ip->ino_data.uflags = dip->ino_data.uflags &
829 				      (SF_NOHISTORY|UF_NOHISTORY|UF_NODUMP);
830 	}
831 
832 	ip->ino_leaf.base.btype = HAMMER_BTREE_TYPE_RECORD;
833 	ip->ino_leaf.base.localization = ip->obj_localization |
834 					 HAMMER_LOCALIZE_INODE;
835 	ip->ino_leaf.base.obj_id = ip->obj_id;
836 	ip->ino_leaf.base.key = 0;
837 	ip->ino_leaf.base.create_tid = 0;
838 	ip->ino_leaf.base.delete_tid = 0;
839 	ip->ino_leaf.base.rec_type = HAMMER_RECTYPE_INODE;
840 	ip->ino_leaf.base.obj_type = hammer_get_obj_type(vap->va_type);
841 
842 	ip->ino_data.obj_type = ip->ino_leaf.base.obj_type;
843 	ip->ino_data.version = HAMMER_INODE_DATA_VERSION;
844 	ip->ino_data.mode = vap->va_mode;
845 	ip->ino_data.ctime = trans->time;
846 
847 	/*
848 	 * If we are running version 2 or greater directory entries are
849 	 * inode-localized instead of data-localized.
850 	 */
851 	if (trans->hmp->version >= HAMMER_VOL_VERSION_TWO) {
852 		if (ip->ino_leaf.base.obj_type == HAMMER_OBJTYPE_DIRECTORY) {
853 			ip->ino_data.cap_flags |=
854 				HAMMER_INODE_CAP_DIR_LOCAL_INO;
855 		}
856 	}
857 	if (trans->hmp->version >= HAMMER_VOL_VERSION_SIX) {
858 		if (ip->ino_leaf.base.obj_type == HAMMER_OBJTYPE_DIRECTORY) {
859 			ip->ino_data.cap_flags |=
860 				HAMMER_INODE_CAP_DIRHASH_ALG1;
861 		}
862 	}
863 
864 	/*
865 	 * Setup the ".." pointer.  This only needs to be done for directories
866 	 * but we do it for all objects as a recovery aid if dip exists.
867 	 * The inode is probably a PFS root if dip is NULL.
868 	 */
869 	if (dip)
870 		ip->ino_data.parent_obj_id = dip->ino_leaf.base.obj_id;
871 
872 	switch(ip->ino_leaf.base.obj_type) {
873 	case HAMMER_OBJTYPE_CDEV:
874 	case HAMMER_OBJTYPE_BDEV:
875 		ip->ino_data.rmajor = vap->va_rmajor;
876 		ip->ino_data.rminor = vap->va_rminor;
877 		break;
878 	default:
879 		break;
880 	}
881 
882 	/*
883 	 * Calculate default uid/gid and overwrite with information from
884 	 * the vap.
885 	 */
886 	if (dip) {
887 		xuid = hammer_to_unix_xid(&dip->ino_data.uid);
888 		xuid = vop_helper_create_uid(hmp->mp, dip->ino_data.mode,
889 					     xuid, cred, &vap->va_mode);
890 	} else {
891 		xuid = 0;
892 	}
893 	ip->ino_data.mode = vap->va_mode;
894 
895 	if (vap->va_vaflags & VA_UID_UUID_VALID)
896 		ip->ino_data.uid = vap->va_uid_uuid;
897 	else if (vap->va_uid != (uid_t)VNOVAL)
898 		hammer_guid_to_uuid(&ip->ino_data.uid, vap->va_uid);
899 	else
900 		hammer_guid_to_uuid(&ip->ino_data.uid, xuid);
901 
902 	if (vap->va_vaflags & VA_GID_UUID_VALID)
903 		ip->ino_data.gid = vap->va_gid_uuid;
904 	else if (vap->va_gid != (gid_t)VNOVAL)
905 		hammer_guid_to_uuid(&ip->ino_data.gid, vap->va_gid);
906 	else if (dip)
907 		ip->ino_data.gid = dip->ino_data.gid;
908 
909 	hammer_ref(&ip->lock);
910 
911 	if (pfsm) {
912 		ip->pfsm = pfsm;
913 		hammer_ref(&pfsm->lock);
914 		error = 0;
915 	} else if (dip->obj_localization == ip->obj_localization) {
916 		ip->pfsm = dip->pfsm;
917 		hammer_ref(&ip->pfsm->lock);
918 		error = 0;
919 	} else {
920 		ip->pfsm = hammer_load_pseudofs(trans,
921 						ip->obj_localization,
922 						&error);
923 		error = 0;	/* ignore ENOENT */
924 	}
925 
926 	if (error) {
927 		hammer_free_inode(ip);
928 		ip = NULL;
929 	} else if (RB_INSERT(hammer_ino_rb_tree, &hmp->rb_inos_root, ip)) {
930 		hpanic("duplicate obj_id %llx", (long long)ip->obj_id);
931 		/* not reached */
932 		hammer_free_inode(ip);
933 	}
934 	*ipp = ip;
935 	return(error);
936 }
937 
938 /*
939  * Final cleanup / freeing of an inode structure
940  */
941 static void
942 hammer_free_inode(hammer_inode_t ip)
943 {
944 	struct hammer_mount *hmp;
945 
946 	hmp = ip->hmp;
947 	KKASSERT(hammer_oneref(&ip->lock));
948 	hammer_uncache_node(&ip->cache[0]);
949 	hammer_uncache_node(&ip->cache[1]);
950 	hammer_uncache_node(&ip->cache[2]);
951 	hammer_uncache_node(&ip->cache[3]);
952 	hammer_inode_wakereclaims(ip);
953 	if (ip->objid_cache)
954 		hammer_clear_objid(ip);
955 	--hammer_count_inodes;
956 	--hmp->count_inodes;
957 	if (ip->pfsm) {
958 		hammer_rel_pseudofs(hmp, ip->pfsm);
959 		ip->pfsm = NULL;
960 	}
961 	kfree(ip, hmp->m_inodes);
962 }
963 
964 /*
965  * Retrieve pseudo-fs data.  NULL will never be returned.
966  *
967  * If an error occurs *errorp will be set and a default template is returned,
968  * otherwise *errorp is set to 0.  Typically when an error occurs it will
969  * be ENOENT.
970  */
971 hammer_pseudofs_inmem_t
972 hammer_load_pseudofs(hammer_transaction_t trans,
973 		     uint32_t localization, int *errorp)
974 {
975 	hammer_mount_t hmp = trans->hmp;
976 	hammer_inode_t ip;
977 	hammer_pseudofs_inmem_t pfsm;
978 	struct hammer_cursor cursor;
979 	int bytes;
980 
981 retry:
982 	pfsm = RB_LOOKUP(hammer_pfs_rb_tree, &hmp->rb_pfsm_root, localization);
983 	if (pfsm) {
984 		hammer_ref(&pfsm->lock);
985 		*errorp = 0;
986 		return(pfsm);
987 	}
988 
989 	/*
990 	 * PFS records are associated with the root inode (not the PFS root
991 	 * inode, but the real root).  Avoid an infinite recursion if loading
992 	 * the PFS for the real root.
993 	 */
994 	if (localization) {
995 		ip = hammer_get_inode(trans, NULL, HAMMER_OBJID_ROOT,
996 				      HAMMER_MAX_TID,
997 				      HAMMER_DEF_LOCALIZATION, 0, errorp);
998 	} else {
999 		ip = NULL;
1000 	}
1001 
1002 	pfsm = kmalloc(sizeof(*pfsm), hmp->m_misc, M_WAITOK | M_ZERO);
1003 	pfsm->localization = localization;
1004 	pfsm->pfsd.unique_uuid = trans->rootvol->ondisk->vol_fsid;
1005 	pfsm->pfsd.shared_uuid = pfsm->pfsd.unique_uuid;
1006 
1007 	hammer_init_cursor(trans, &cursor, (ip ? &ip->cache[1] : NULL), ip);
1008 	cursor.key_beg.localization = HAMMER_DEF_LOCALIZATION |
1009 				      HAMMER_LOCALIZE_MISC;
1010 	cursor.key_beg.obj_id = HAMMER_OBJID_ROOT;
1011 	cursor.key_beg.create_tid = 0;
1012 	cursor.key_beg.delete_tid = 0;
1013 	cursor.key_beg.rec_type = HAMMER_RECTYPE_PFS;
1014 	cursor.key_beg.obj_type = 0;
1015 	cursor.key_beg.key = localization;
1016 	cursor.asof = HAMMER_MAX_TID;
1017 	cursor.flags |= HAMMER_CURSOR_ASOF;
1018 
1019 	if (ip)
1020 		*errorp = hammer_ip_lookup(&cursor);
1021 	else
1022 		*errorp = hammer_btree_lookup(&cursor);
1023 	if (*errorp == 0) {
1024 		*errorp = hammer_ip_resolve_data(&cursor);
1025 		if (*errorp == 0) {
1026 			if (cursor.data->pfsd.mirror_flags &
1027 			    HAMMER_PFSD_DELETED) {
1028 				*errorp = ENOENT;
1029 			} else {
1030 				bytes = cursor.leaf->data_len;
1031 				if (bytes > sizeof(pfsm->pfsd))
1032 					bytes = sizeof(pfsm->pfsd);
1033 				bcopy(cursor.data, &pfsm->pfsd, bytes);
1034 			}
1035 		}
1036 	}
1037 	hammer_done_cursor(&cursor);
1038 
1039 	pfsm->fsid_udev = hammer_fsid_to_udev(&pfsm->pfsd.shared_uuid);
1040 	hammer_ref(&pfsm->lock);
1041 	if (ip)
1042 		hammer_rel_inode(ip, 0);
1043 	if (RB_INSERT(hammer_pfs_rb_tree, &hmp->rb_pfsm_root, pfsm)) {
1044 		kfree(pfsm, hmp->m_misc);
1045 		goto retry;
1046 	}
1047 	return(pfsm);
1048 }
1049 
1050 /*
1051  * Store pseudo-fs data.  The backend will automatically delete any prior
1052  * on-disk pseudo-fs data but we have to delete in-memory versions.
1053  */
1054 int
1055 hammer_save_pseudofs(hammer_transaction_t trans, hammer_pseudofs_inmem_t pfsm)
1056 {
1057 	struct hammer_cursor cursor;
1058 	hammer_record_t record;
1059 	hammer_inode_t ip;
1060 	int error;
1061 
1062 	/*
1063 	 * PFS records are associated with the root inode (not the PFS root
1064 	 * inode, but the real root).
1065 	 */
1066 	ip = hammer_get_inode(trans, NULL, HAMMER_OBJID_ROOT, HAMMER_MAX_TID,
1067 			      HAMMER_DEF_LOCALIZATION, 0, &error);
1068 retry:
1069 	pfsm->fsid_udev = hammer_fsid_to_udev(&pfsm->pfsd.shared_uuid);
1070 	hammer_init_cursor(trans, &cursor, &ip->cache[1], ip);
1071 	cursor.key_beg.localization = ip->obj_localization |
1072 				      HAMMER_LOCALIZE_MISC;
1073 	cursor.key_beg.obj_id = HAMMER_OBJID_ROOT;
1074 	cursor.key_beg.create_tid = 0;
1075 	cursor.key_beg.delete_tid = 0;
1076 	cursor.key_beg.rec_type = HAMMER_RECTYPE_PFS;
1077 	cursor.key_beg.obj_type = 0;
1078 	cursor.key_beg.key = pfsm->localization;
1079 	cursor.asof = HAMMER_MAX_TID;
1080 	cursor.flags |= HAMMER_CURSOR_ASOF;
1081 
1082 	/*
1083 	 * Replace any in-memory version of the record.
1084 	 */
1085 	error = hammer_ip_lookup(&cursor);
1086 	if (error == 0 && hammer_cursor_inmem(&cursor)) {
1087 		record = cursor.iprec;
1088 		if (record->flags & HAMMER_RECF_INTERLOCK_BE) {
1089 			KKASSERT(cursor.deadlk_rec == NULL);
1090 			hammer_ref(&record->lock);
1091 			cursor.deadlk_rec = record;
1092 			error = EDEADLK;
1093 		} else {
1094 			record->flags |= HAMMER_RECF_DELETED_FE;
1095 			error = 0;
1096 		}
1097 	}
1098 
1099 	/*
1100 	 * Allocate replacement general record.  The backend flush will
1101 	 * delete any on-disk version of the record.
1102 	 */
1103 	if (error == 0 || error == ENOENT) {
1104 		record = hammer_alloc_mem_record(ip, sizeof(pfsm->pfsd));
1105 		record->type = HAMMER_MEM_RECORD_GENERAL;
1106 
1107 		record->leaf.base.localization = ip->obj_localization |
1108 						 HAMMER_LOCALIZE_MISC;
1109 		record->leaf.base.rec_type = HAMMER_RECTYPE_PFS;
1110 		record->leaf.base.key = pfsm->localization;
1111 		record->leaf.data_len = sizeof(pfsm->pfsd);
1112 		bcopy(&pfsm->pfsd, record->data, sizeof(pfsm->pfsd));
1113 		error = hammer_ip_add_record(trans, record);
1114 	}
1115 	hammer_done_cursor(&cursor);
1116 	if (error == EDEADLK)
1117 		goto retry;
1118 	hammer_rel_inode(ip, 0);
1119 	return(error);
1120 }
1121 
1122 /*
1123  * Create a root directory for a PFS if one does not alredy exist.
1124  *
1125  * The PFS root stands alone so we must also bump the nlinks count
1126  * to prevent it from being destroyed on release.
1127  */
1128 int
1129 hammer_mkroot_pseudofs(hammer_transaction_t trans, struct ucred *cred,
1130 		       hammer_pseudofs_inmem_t pfsm)
1131 {
1132 	hammer_inode_t ip;
1133 	struct vattr vap;
1134 	int error;
1135 
1136 	ip = hammer_get_inode(trans, NULL, HAMMER_OBJID_ROOT, HAMMER_MAX_TID,
1137 			      pfsm->localization, 0, &error);
1138 	if (ip == NULL) {
1139 		vattr_null(&vap);
1140 		vap.va_mode = 0755;
1141 		vap.va_type = VDIR;
1142 		error = hammer_create_inode(trans, &vap, cred,
1143 					    NULL, NULL, 0,
1144 					    pfsm, &ip);
1145 		if (error == 0) {
1146 			++ip->ino_data.nlinks;
1147 			hammer_modify_inode(trans, ip, HAMMER_INODE_DDIRTY);
1148 		}
1149 	}
1150 	if (ip)
1151 		hammer_rel_inode(ip, 0);
1152 	return(error);
1153 }
1154 
1155 /*
1156  * Unload any vnodes & inodes associated with a PFS, return ENOTEMPTY
1157  * if we are unable to disassociate all the inodes.
1158  */
1159 static
1160 int
1161 hammer_unload_pseudofs_callback(hammer_inode_t ip, void *data)
1162 {
1163 	int res;
1164 
1165 	hammer_ref(&ip->lock);
1166 	if (ip->vp && (ip->vp->v_flag & VPFSROOT)) {
1167 		/*
1168 		 * The hammer pfs-upgrade directive itself might have the
1169 		 * root of the pfs open.  Just allow it.
1170 		 */
1171 		res = 0;
1172 	} else {
1173 		/*
1174 		 * Don't allow any subdirectories or files to be open.
1175 		 */
1176 		if (hammer_isactive(&ip->lock) == 2 && ip->vp)
1177 			vclean_unlocked(ip->vp);
1178 		if (hammer_isactive(&ip->lock) == 1 && ip->vp == NULL)
1179 			res = 0;
1180 		else
1181 			res = -1;	/* stop, someone is using the inode */
1182 	}
1183 	hammer_rel_inode(ip, 0);
1184 	return(res);
1185 }
1186 
1187 int
1188 hammer_unload_pseudofs(hammer_transaction_t trans, uint32_t localization)
1189 {
1190 	int res;
1191 	int try;
1192 
1193 	for (try = res = 0; try < 4; ++try) {
1194 		res = hammer_ino_rb_tree_RB_SCAN(&trans->hmp->rb_inos_root,
1195 					   hammer_inode_pfs_cmp,
1196 					   hammer_unload_pseudofs_callback,
1197 					   &localization);
1198 		if (res == 0 && try > 1)
1199 			break;
1200 		hammer_flusher_sync(trans->hmp);
1201 	}
1202 	if (res != 0)
1203 		res = ENOTEMPTY;
1204 	return(res);
1205 }
1206 
1207 
1208 /*
1209  * Release a reference on a PFS
1210  */
1211 void
1212 hammer_rel_pseudofs(hammer_mount_t hmp, hammer_pseudofs_inmem_t pfsm)
1213 {
1214 	hammer_rel(&pfsm->lock);
1215 	if (hammer_norefs(&pfsm->lock)) {
1216 		RB_REMOVE(hammer_pfs_rb_tree, &hmp->rb_pfsm_root, pfsm);
1217 		kfree(pfsm, hmp->m_misc);
1218 	}
1219 }
1220 
1221 /*
1222  * Called by hammer_sync_inode().
1223  */
1224 static int
1225 hammer_update_inode(hammer_cursor_t cursor, hammer_inode_t ip)
1226 {
1227 	hammer_transaction_t trans = cursor->trans;
1228 	hammer_record_t record;
1229 	int error;
1230 	int redirty;
1231 
1232 retry:
1233 	error = 0;
1234 
1235 	/*
1236 	 * If the inode has a presence on-disk then locate it and mark
1237 	 * it deleted, setting DELONDISK.
1238 	 *
1239 	 * The record may or may not be physically deleted, depending on
1240 	 * the retention policy.
1241 	 */
1242 	if ((ip->flags & (HAMMER_INODE_ONDISK|HAMMER_INODE_DELONDISK)) ==
1243 	    HAMMER_INODE_ONDISK) {
1244 		hammer_normalize_cursor(cursor);
1245 		cursor->key_beg.localization = ip->obj_localization |
1246 					       HAMMER_LOCALIZE_INODE;
1247 		cursor->key_beg.obj_id = ip->obj_id;
1248 		cursor->key_beg.key = 0;
1249 		cursor->key_beg.create_tid = 0;
1250 		cursor->key_beg.delete_tid = 0;
1251 		cursor->key_beg.rec_type = HAMMER_RECTYPE_INODE;
1252 		cursor->key_beg.obj_type = 0;
1253 		cursor->asof = ip->obj_asof;
1254 		cursor->flags &= ~HAMMER_CURSOR_INITMASK;
1255 		cursor->flags |= HAMMER_CURSOR_GET_LEAF | HAMMER_CURSOR_ASOF;
1256 		cursor->flags |= HAMMER_CURSOR_BACKEND;
1257 
1258 		error = hammer_btree_lookup(cursor);
1259 		if (hammer_debug_inode)
1260 			hdkprintf("IPDEL %p %08x %d", ip, ip->flags, error);
1261 
1262 		if (error == 0) {
1263 			error = hammer_ip_delete_record(cursor, ip, trans->tid);
1264 			if (hammer_debug_inode)
1265 				hdkprintf("error %d\n", error);
1266 			if (error == 0) {
1267 				ip->flags |= HAMMER_INODE_DELONDISK;
1268 			}
1269 			if (cursor->node)
1270 				hammer_cache_node(&ip->cache[0], cursor->node);
1271 		}
1272 		if (error == EDEADLK) {
1273 			hammer_done_cursor(cursor);
1274 			error = hammer_init_cursor(trans, cursor,
1275 						   &ip->cache[0], ip);
1276 			if (hammer_debug_inode)
1277 				hdkprintf("IPDED %p %d\n", ip, error);
1278 			if (error == 0)
1279 				goto retry;
1280 		}
1281 	}
1282 
1283 	/*
1284 	 * Ok, write out the initial record or a new record (after deleting
1285 	 * the old one), unless the DELETED flag is set.  This routine will
1286 	 * clear DELONDISK if it writes out a record.
1287 	 *
1288 	 * Update our inode statistics if this is the first application of
1289 	 * the inode on-disk.
1290 	 */
1291 	if (error == 0 && (ip->flags & HAMMER_INODE_DELETED) == 0) {
1292 		/*
1293 		 * Generate a record and write it to the media.  We clean-up
1294 		 * the state before releasing so we do not have to set-up
1295 		 * a flush_group.
1296 		 */
1297 		record = hammer_alloc_mem_record(ip, 0);
1298 		record->type = HAMMER_MEM_RECORD_INODE;
1299 		record->flush_state = HAMMER_FST_FLUSH;
1300 		record->leaf = ip->sync_ino_leaf;
1301 		record->leaf.base.create_tid = trans->tid;
1302 		record->leaf.data_len = sizeof(ip->sync_ino_data);
1303 		record->leaf.create_ts = trans->time32;
1304 		record->data = (void *)&ip->sync_ino_data;
1305 		record->flags |= HAMMER_RECF_INTERLOCK_BE;
1306 
1307 		/*
1308 		 * If this flag is set we cannot sync the new file size
1309 		 * because we haven't finished related truncations.  The
1310 		 * inode will be flushed in another flush group to finish
1311 		 * the job.
1312 		 */
1313 		if ((ip->flags & HAMMER_INODE_WOULDBLOCK) &&
1314 		    ip->sync_ino_data.size != ip->ino_data.size) {
1315 			redirty = 1;
1316 			ip->sync_ino_data.size = ip->ino_data.size;
1317 		} else {
1318 			redirty = 0;
1319 		}
1320 
1321 		for (;;) {
1322 			error = hammer_ip_sync_record_cursor(cursor, record);
1323 			if (hammer_debug_inode)
1324 				hdkprintf("GENREC %p rec %08x %d\n",
1325 					ip, record->flags, error);
1326 			if (error != EDEADLK)
1327 				break;
1328 			hammer_done_cursor(cursor);
1329 			error = hammer_init_cursor(trans, cursor,
1330 						   &ip->cache[0], ip);
1331 			if (hammer_debug_inode)
1332 				hdkprintf("GENREC reinit %d\n", error);
1333 			if (error)
1334 				break;
1335 		}
1336 
1337 		/*
1338 		 * Note:  The record was never on the inode's record tree
1339 		 * so just wave our hands importantly and destroy it.
1340 		 */
1341 		record->flags |= HAMMER_RECF_COMMITTED;
1342 		record->flags &= ~HAMMER_RECF_INTERLOCK_BE;
1343 		record->flush_state = HAMMER_FST_IDLE;
1344 		++ip->rec_generation;
1345 		hammer_rel_mem_record(record);
1346 
1347 		/*
1348 		 * Finish up.
1349 		 */
1350 		if (error == 0) {
1351 			if (hammer_debug_inode)
1352 				hdkprintf("CLEANDELOND %p %08x\n", ip, ip->flags);
1353 			ip->sync_flags &= ~(HAMMER_INODE_DDIRTY |
1354 					    HAMMER_INODE_SDIRTY |
1355 					    HAMMER_INODE_ATIME |
1356 					    HAMMER_INODE_MTIME);
1357 			ip->flags &= ~HAMMER_INODE_DELONDISK;
1358 			if (redirty)
1359 				ip->sync_flags |= HAMMER_INODE_DDIRTY;
1360 
1361 			/*
1362 			 * Root volume count of inodes
1363 			 */
1364 			hammer_sync_lock_sh(trans);
1365 			if ((ip->flags & HAMMER_INODE_ONDISK) == 0) {
1366 				hammer_modify_volume_field(trans,
1367 							   trans->rootvol,
1368 							   vol0_stat_inodes);
1369 				++ip->hmp->rootvol->ondisk->vol0_stat_inodes;
1370 				hammer_modify_volume_done(trans->rootvol);
1371 				ip->flags |= HAMMER_INODE_ONDISK;
1372 				if (hammer_debug_inode)
1373 					hdkprintf("NOWONDISK %p\n", ip);
1374 			}
1375 			hammer_sync_unlock(trans);
1376 		}
1377 	}
1378 
1379 	/*
1380 	 * If the inode has been destroyed, clean out any left-over flags
1381 	 * that may have been set by the frontend.
1382 	 */
1383 	if (error == 0 && (ip->flags & HAMMER_INODE_DELETED)) {
1384 		ip->sync_flags &= ~(HAMMER_INODE_DDIRTY |
1385 				    HAMMER_INODE_SDIRTY |
1386 				    HAMMER_INODE_ATIME |
1387 				    HAMMER_INODE_MTIME);
1388 	}
1389 	return(error);
1390 }
1391 
1392 /*
1393  * Update only the itimes fields.
1394  *
1395  * ATIME can be updated without generating any UNDO.  MTIME is updated
1396  * with UNDO so it is guaranteed to be synchronized properly in case of
1397  * a crash.
1398  *
1399  * Neither field is included in the B-Tree leaf element's CRC, which is how
1400  * we can get away with updating ATIME the way we do.
1401  */
1402 static int
1403 hammer_update_itimes(hammer_cursor_t cursor, hammer_inode_t ip)
1404 {
1405 	hammer_transaction_t trans = cursor->trans;
1406 	int error;
1407 
1408 retry:
1409 	if ((ip->flags & (HAMMER_INODE_ONDISK|HAMMER_INODE_DELONDISK)) !=
1410 	    HAMMER_INODE_ONDISK) {
1411 		return(0);
1412 	}
1413 
1414 	hammer_normalize_cursor(cursor);
1415 	cursor->key_beg.localization = ip->obj_localization |
1416 				       HAMMER_LOCALIZE_INODE;
1417 	cursor->key_beg.obj_id = ip->obj_id;
1418 	cursor->key_beg.key = 0;
1419 	cursor->key_beg.create_tid = 0;
1420 	cursor->key_beg.delete_tid = 0;
1421 	cursor->key_beg.rec_type = HAMMER_RECTYPE_INODE;
1422 	cursor->key_beg.obj_type = 0;
1423 	cursor->asof = ip->obj_asof;
1424 	cursor->flags &= ~HAMMER_CURSOR_INITMASK;
1425 	cursor->flags |= HAMMER_CURSOR_ASOF;
1426 	cursor->flags |= HAMMER_CURSOR_GET_LEAF;
1427 	cursor->flags |= HAMMER_CURSOR_GET_DATA;
1428 	cursor->flags |= HAMMER_CURSOR_BACKEND;
1429 
1430 	error = hammer_btree_lookup(cursor);
1431 	if (error == 0) {
1432 		hammer_cache_node(&ip->cache[0], cursor->node);
1433 		if (ip->sync_flags & HAMMER_INODE_MTIME) {
1434 			/*
1435 			 * Updating MTIME requires an UNDO.  Just cover
1436 			 * both atime and mtime.
1437 			 */
1438 			hammer_sync_lock_sh(trans);
1439 			hammer_modify_buffer(trans, cursor->data_buffer,
1440 				&cursor->data->inode.mtime,
1441 				sizeof(cursor->data->inode.atime) +
1442 				sizeof(cursor->data->inode.mtime));
1443 			cursor->data->inode.atime = ip->sync_ino_data.atime;
1444 			cursor->data->inode.mtime = ip->sync_ino_data.mtime;
1445 			hammer_modify_buffer_done(cursor->data_buffer);
1446 			hammer_sync_unlock(trans);
1447 		} else if (ip->sync_flags & HAMMER_INODE_ATIME) {
1448 			/*
1449 			 * Updating atime only can be done in-place with
1450 			 * no UNDO.
1451 			 */
1452 			hammer_sync_lock_sh(trans);
1453 			hammer_modify_buffer_noundo(trans, cursor->data_buffer);
1454 			cursor->data->inode.atime = ip->sync_ino_data.atime;
1455 			hammer_modify_buffer_done(cursor->data_buffer);
1456 			hammer_sync_unlock(trans);
1457 		}
1458 		ip->sync_flags &= ~(HAMMER_INODE_ATIME | HAMMER_INODE_MTIME);
1459 	}
1460 	if (error == EDEADLK) {
1461 		hammer_done_cursor(cursor);
1462 		error = hammer_init_cursor(trans, cursor, &ip->cache[0], ip);
1463 		if (error == 0)
1464 			goto retry;
1465 	}
1466 	return(error);
1467 }
1468 
1469 /*
1470  * Release a reference on an inode, flush as requested.
1471  *
1472  * On the last reference we queue the inode to the flusher for its final
1473  * disposition.
1474  */
1475 void
1476 hammer_rel_inode(struct hammer_inode *ip, int flush)
1477 {
1478 	/*
1479 	 * Handle disposition when dropping the last ref.
1480 	 */
1481 	for (;;) {
1482 		if (hammer_oneref(&ip->lock)) {
1483 			/*
1484 			 * Determine whether on-disk action is needed for
1485 			 * the inode's final disposition.
1486 			 */
1487 			KKASSERT(ip->vp == NULL);
1488 			hammer_inode_unloadable_check(ip, 0);
1489 			if (ip->flags & HAMMER_INODE_MODMASK) {
1490 				hammer_flush_inode(ip, 0);
1491 			} else if (hammer_oneref(&ip->lock)) {
1492 				hammer_unload_inode(ip);
1493 				break;
1494 			}
1495 		} else {
1496 			if (flush)
1497 				hammer_flush_inode(ip, 0);
1498 
1499 			/*
1500 			 * The inode still has multiple refs, try to drop
1501 			 * one ref.
1502 			 */
1503 			KKASSERT(hammer_isactive(&ip->lock) >= 1);
1504 			if (hammer_isactive(&ip->lock) > 1) {
1505 				hammer_rel(&ip->lock);
1506 				break;
1507 			}
1508 		}
1509 	}
1510 }
1511 
1512 /*
1513  * Unload and destroy the specified inode.  Must be called with one remaining
1514  * reference.  The reference is disposed of.
1515  *
1516  * The inode must be completely clean.
1517  */
1518 static int
1519 hammer_unload_inode(struct hammer_inode *ip)
1520 {
1521 	hammer_mount_t hmp = ip->hmp;
1522 
1523 	KASSERT(hammer_oneref(&ip->lock),
1524 		("hammer_unload_inode: %d refs", hammer_isactive(&ip->lock)));
1525 	KKASSERT(ip->vp == NULL);
1526 	KKASSERT(ip->flush_state == HAMMER_FST_IDLE);
1527 	KKASSERT(ip->cursor_ip_refs == 0);
1528 	KKASSERT(hammer_notlocked(&ip->lock));
1529 	KKASSERT((ip->flags & HAMMER_INODE_MODMASK) == 0);
1530 
1531 	KKASSERT(RB_EMPTY(&ip->rec_tree));
1532 	KKASSERT(TAILQ_EMPTY(&ip->target_list));
1533 
1534 	if (ip->flags & HAMMER_INODE_RDIRTY) {
1535 		RB_REMOVE(hammer_redo_rb_tree, &hmp->rb_redo_root, ip);
1536 		ip->flags &= ~HAMMER_INODE_RDIRTY;
1537 	}
1538 	RB_REMOVE(hammer_ino_rb_tree, &hmp->rb_inos_root, ip);
1539 
1540 	hammer_free_inode(ip);
1541 	return(0);
1542 }
1543 
1544 /*
1545  * Called during unmounting if a critical error occured.  The in-memory
1546  * inode and all related structures are destroyed.
1547  *
1548  * If a critical error did not occur the unmount code calls the standard
1549  * release and asserts that the inode is gone.
1550  */
1551 int
1552 hammer_destroy_inode_callback(struct hammer_inode *ip, void *data __unused)
1553 {
1554 	hammer_record_t rec;
1555 
1556 	/*
1557 	 * Get rid of the inodes in-memory records, regardless of their
1558 	 * state, and clear the mod-mask.
1559 	 */
1560 	while ((rec = TAILQ_FIRST(&ip->target_list)) != NULL) {
1561 		TAILQ_REMOVE(&ip->target_list, rec, target_entry);
1562 		rec->target_ip = NULL;
1563 		if (rec->flush_state == HAMMER_FST_SETUP)
1564 			rec->flush_state = HAMMER_FST_IDLE;
1565 	}
1566 	while ((rec = RB_ROOT(&ip->rec_tree)) != NULL) {
1567 		if (rec->flush_state == HAMMER_FST_FLUSH)
1568 			--rec->flush_group->refs;
1569 		else
1570 			hammer_ref(&rec->lock);
1571 		KKASSERT(hammer_oneref(&rec->lock));
1572 		rec->flush_state = HAMMER_FST_IDLE;
1573 		rec->flush_group = NULL;
1574 		rec->flags |= HAMMER_RECF_DELETED_FE; /* wave hands */
1575 		rec->flags |= HAMMER_RECF_DELETED_BE; /* wave hands */
1576 		++ip->rec_generation;
1577 		hammer_rel_mem_record(rec);
1578 	}
1579 	ip->flags &= ~HAMMER_INODE_MODMASK;
1580 	ip->sync_flags &= ~HAMMER_INODE_MODMASK;
1581 	KKASSERT(ip->vp == NULL);
1582 
1583 	/*
1584 	 * Remove the inode from any flush group, force it idle.  FLUSH
1585 	 * and SETUP states have an inode ref.
1586 	 */
1587 	switch(ip->flush_state) {
1588 	case HAMMER_FST_FLUSH:
1589 		RB_REMOVE(hammer_fls_rb_tree, &ip->flush_group->flush_tree, ip);
1590 		--ip->flush_group->refs;
1591 		ip->flush_group = NULL;
1592 		/* fall through */
1593 	case HAMMER_FST_SETUP:
1594 		hammer_rel(&ip->lock);
1595 		ip->flush_state = HAMMER_FST_IDLE;
1596 		/* fall through */
1597 	case HAMMER_FST_IDLE:
1598 		break;
1599 	}
1600 
1601 	/*
1602 	 * There shouldn't be any associated vnode.  The unload needs at
1603 	 * least one ref, if we do have a vp steal its ip ref.
1604 	 */
1605 	if (ip->vp) {
1606 		hdkprintf("Unexpected vnode association ip %p vp %p\n",
1607 			ip, ip->vp);
1608 		ip->vp->v_data = NULL;
1609 		ip->vp = NULL;
1610 	} else {
1611 		hammer_ref(&ip->lock);
1612 	}
1613 	hammer_unload_inode(ip);
1614 	return(0);
1615 }
1616 
1617 /*
1618  * Called on mount -u when switching from RW to RO or vise-versa.  Adjust
1619  * the read-only flag for cached inodes.
1620  *
1621  * This routine is called from a RB_SCAN().
1622  */
1623 int
1624 hammer_reload_inode(hammer_inode_t ip, void *arg __unused)
1625 {
1626 	hammer_mount_t hmp = ip->hmp;
1627 
1628 	if (hmp->ronly || hmp->asof != HAMMER_MAX_TID)
1629 		ip->flags |= HAMMER_INODE_RO;
1630 	else
1631 		ip->flags &= ~HAMMER_INODE_RO;
1632 	return(0);
1633 }
1634 
1635 /*
1636  * A transaction has modified an inode, requiring updates as specified by
1637  * the passed flags.
1638  *
1639  * HAMMER_INODE_DDIRTY: Inode data has been updated, not incl mtime/atime,
1640  *			and not including size changes due to write-append
1641  *			(but other size changes are included).
1642  * HAMMER_INODE_SDIRTY: Inode data has been updated, size changes due to
1643  *			write-append.
1644  * HAMMER_INODE_XDIRTY: Dirty in-memory records
1645  * HAMMER_INODE_BUFS:   Dirty buffer cache buffers
1646  * HAMMER_INODE_DELETED: Inode record/data must be deleted
1647  * HAMMER_INODE_ATIME/MTIME: mtime/atime has been updated
1648  */
1649 void
1650 hammer_modify_inode(hammer_transaction_t trans, hammer_inode_t ip, int flags)
1651 {
1652 	/*
1653 	 * ronly of 0 or 2 does not trigger assertion.
1654 	 * 2 is a special error state
1655 	 */
1656 	KKASSERT(ip->hmp->ronly != 1 ||
1657 		  (flags & (HAMMER_INODE_DDIRTY | HAMMER_INODE_XDIRTY |
1658 			    HAMMER_INODE_SDIRTY |
1659 			    HAMMER_INODE_BUFS | HAMMER_INODE_DELETED |
1660 			    HAMMER_INODE_ATIME | HAMMER_INODE_MTIME)) == 0);
1661 	if ((ip->flags & HAMMER_INODE_RSV_INODES) == 0) {
1662 		ip->flags |= HAMMER_INODE_RSV_INODES;
1663 		++ip->hmp->rsv_inodes;
1664 	}
1665 
1666 	/*
1667 	 * Set the NEWINODE flag in the transaction if the inode
1668 	 * transitions to a dirty state.  This is used to track
1669 	 * the load on the inode cache.
1670 	 */
1671 	if (trans &&
1672 	    (ip->flags & HAMMER_INODE_MODMASK) == 0 &&
1673 	    (flags & HAMMER_INODE_MODMASK)) {
1674 		trans->flags |= HAMMER_TRANSF_NEWINODE;
1675 	}
1676 	if (flags & HAMMER_INODE_MODMASK)
1677 		hammer_inode_dirty(ip);
1678 	ip->flags |= flags;
1679 }
1680 
1681 /*
1682  * Attempt to quickly update the atime for a hammer inode.  Return 0 on
1683  * success, -1 on failure.
1684  *
1685  * We attempt to update the atime with only the ip lock and not the
1686  * whole filesystem lock in order to improve concurrency.  We can only
1687  * do this safely if the ATIME flag is already pending on the inode.
1688  *
1689  * This function is called via a vnops path (ip pointer is stable) without
1690  * fs_token held.
1691  */
1692 int
1693 hammer_update_atime_quick(hammer_inode_t ip)
1694 {
1695 	struct timeval tv;
1696 	int res = -1;
1697 
1698 	if ((ip->flags & HAMMER_INODE_RO) ||
1699 	    (ip->hmp->mp->mnt_flag & MNT_NOATIME)) {
1700 		/*
1701 		 * Silently indicate success on read-only mount/snap
1702 		 */
1703 		res = 0;
1704 	} else if (ip->flags & HAMMER_INODE_ATIME) {
1705 		/*
1706 		 * Double check with inode lock held against backend.  This
1707 		 * is only safe if all we need to do is update
1708 		 * ino_data.atime.
1709 		 */
1710 		getmicrotime(&tv);
1711 		hammer_lock_ex(&ip->lock);
1712 		if (ip->flags & HAMMER_INODE_ATIME) {
1713 			ip->ino_data.atime =
1714 			    (unsigned long)tv.tv_sec * 1000000ULL + tv.tv_usec;
1715 			res = 0;
1716 		}
1717 		hammer_unlock(&ip->lock);
1718 	}
1719 	return res;
1720 }
1721 
1722 /*
1723  * Request that an inode be flushed.  This whole mess cannot block and may
1724  * recurse (if not synchronous).  Once requested HAMMER will attempt to
1725  * actively flush the inode until the flush can be done.
1726  *
1727  * The inode may already be flushing, or may be in a setup state.  We can
1728  * place the inode in a flushing state if it is currently idle and flag it
1729  * to reflush if it is currently flushing.
1730  *
1731  * Upon return if the inode could not be flushed due to a setup
1732  * dependancy, then it will be automatically flushed when the dependancy
1733  * is satisfied.
1734  */
1735 void
1736 hammer_flush_inode(hammer_inode_t ip, int flags)
1737 {
1738 	hammer_mount_t hmp;
1739 	hammer_flush_group_t flg;
1740 	int good;
1741 
1742 	/*
1743 	 * fill_flush_group is the first flush group we may be able to
1744 	 * continue filling, it may be open or closed but it will always
1745 	 * be past the currently flushing (running) flg.
1746 	 *
1747 	 * next_flush_group is the next open flush group.
1748 	 */
1749 	hmp = ip->hmp;
1750 	while ((flg = hmp->fill_flush_group) != NULL) {
1751 		KKASSERT(flg->running == 0);
1752 		if (flg->total_count + flg->refs <= ip->hmp->undo_rec_limit &&
1753 		    flg->total_count <= hammer_autoflush) {
1754 			break;
1755 		}
1756 		hmp->fill_flush_group = TAILQ_NEXT(flg, flush_entry);
1757 		hammer_flusher_async(ip->hmp, flg);
1758 	}
1759 	if (flg == NULL) {
1760 		flg = kmalloc(sizeof(*flg), hmp->m_misc, M_WAITOK|M_ZERO);
1761 		flg->seq = hmp->flusher.next++;
1762 		if (hmp->next_flush_group == NULL)
1763 			hmp->next_flush_group = flg;
1764 		if (hmp->fill_flush_group == NULL)
1765 			hmp->fill_flush_group = flg;
1766 		RB_INIT(&flg->flush_tree);
1767 		TAILQ_INSERT_TAIL(&hmp->flush_group_list, flg, flush_entry);
1768 	}
1769 
1770 	/*
1771 	 * Trivial 'nothing to flush' case.  If the inode is in a SETUP
1772 	 * state we have to put it back into an IDLE state so we can
1773 	 * drop the extra ref.
1774 	 *
1775 	 * If we have a parent dependancy we must still fall through
1776 	 * so we can run it.
1777 	 */
1778 	if ((ip->flags & HAMMER_INODE_MODMASK) == 0) {
1779 		if (ip->flush_state == HAMMER_FST_SETUP &&
1780 		    TAILQ_EMPTY(&ip->target_list)) {
1781 			ip->flush_state = HAMMER_FST_IDLE;
1782 			hammer_rel_inode(ip, 0);
1783 		}
1784 		if (ip->flush_state == HAMMER_FST_IDLE)
1785 			return;
1786 	}
1787 
1788 	/*
1789 	 * Our flush action will depend on the current state.
1790 	 */
1791 	switch(ip->flush_state) {
1792 	case HAMMER_FST_IDLE:
1793 		/*
1794 		 * We have no dependancies and can flush immediately.  Some
1795 		 * our children may not be flushable so we have to re-test
1796 		 * with that additional knowledge.
1797 		 */
1798 		hammer_flush_inode_core(ip, flg, flags);
1799 		break;
1800 	case HAMMER_FST_SETUP:
1801 		/*
1802 		 * Recurse upwards through dependancies via target_list
1803 		 * and start their flusher actions going if possible.
1804 		 *
1805 		 * 'good' is our connectivity.  -1 means we have none and
1806 		 * can't flush, 0 means there weren't any dependancies, and
1807 		 * 1 means we have good connectivity.
1808 		 */
1809 		good = hammer_setup_parent_inodes(ip, 0, flg);
1810 
1811 		if (good >= 0) {
1812 			/*
1813 			 * We can continue if good >= 0.  Determine how
1814 			 * many records under our inode can be flushed (and
1815 			 * mark them).
1816 			 */
1817 			hammer_flush_inode_core(ip, flg, flags);
1818 		} else {
1819 			/*
1820 			 * Parent has no connectivity, tell it to flush
1821 			 * us as soon as it does.
1822 			 *
1823 			 * The REFLUSH flag is also needed to trigger
1824 			 * dependancy wakeups.
1825 			 */
1826 			ip->flags |= HAMMER_INODE_CONN_DOWN |
1827 				     HAMMER_INODE_REFLUSH;
1828 			if (flags & HAMMER_FLUSH_SIGNAL) {
1829 				ip->flags |= HAMMER_INODE_RESIGNAL;
1830 				hammer_flusher_async(ip->hmp, flg);
1831 			}
1832 		}
1833 		break;
1834 	case HAMMER_FST_FLUSH:
1835 		/*
1836 		 * We are already flushing, flag the inode to reflush
1837 		 * if needed after it completes its current flush.
1838 		 *
1839 		 * The REFLUSH flag is also needed to trigger
1840 		 * dependancy wakeups.
1841 		 */
1842 		if ((ip->flags & HAMMER_INODE_REFLUSH) == 0)
1843 			ip->flags |= HAMMER_INODE_REFLUSH;
1844 		if (flags & HAMMER_FLUSH_SIGNAL) {
1845 			ip->flags |= HAMMER_INODE_RESIGNAL;
1846 			hammer_flusher_async(ip->hmp, flg);
1847 		}
1848 		break;
1849 	}
1850 }
1851 
1852 /*
1853  * Scan ip->target_list, which is a list of records owned by PARENTS to our
1854  * ip which reference our ip.
1855  *
1856  * XXX This is a huge mess of recursive code, but not one bit of it blocks
1857  *     so for now do not ref/deref the structures.  Note that if we use the
1858  *     ref/rel code later, the rel CAN block.
1859  */
1860 static int
1861 hammer_setup_parent_inodes(hammer_inode_t ip, int depth,
1862 			   hammer_flush_group_t flg)
1863 {
1864 	hammer_record_t depend;
1865 	int good;
1866 	int r;
1867 
1868 	/*
1869 	 * If we hit our recursion limit and we have parent dependencies
1870 	 * We cannot continue.  Returning < 0 will cause us to be flagged
1871 	 * for reflush.  Returning -2 cuts off additional dependency checks
1872 	 * because they are likely to also hit the depth limit.
1873 	 *
1874 	 * We cannot return < 0 if there are no dependencies or there might
1875 	 * not be anything to wakeup (ip).
1876 	 */
1877 	if (depth == 20 && TAILQ_FIRST(&ip->target_list)) {
1878 		if (hammer_debug_general & 0x10000)
1879 			hkrateprintf(&hammer_gen_krate,
1880 			    "Warning: depth limit reached on "
1881 			    "setup recursion, inode %p %016llx\n",
1882 			    ip, (long long)ip->obj_id);
1883 		return(-2);
1884 	}
1885 
1886 	/*
1887 	 * Scan dependencies
1888 	 */
1889 	good = 0;
1890 	TAILQ_FOREACH(depend, &ip->target_list, target_entry) {
1891 		r = hammer_setup_parent_inodes_helper(depend, depth, flg);
1892 		KKASSERT(depend->target_ip == ip);
1893 		if (r < 0 && good == 0)
1894 			good = -1;
1895 		if (r > 0)
1896 			good = 1;
1897 
1898 		/*
1899 		 * If we failed due to the recursion depth limit then stop
1900 		 * now.
1901 		 */
1902 		if (r == -2)
1903 			break;
1904 	}
1905 	return(good);
1906 }
1907 
1908 /*
1909  * This helper function takes a record representing the dependancy between
1910  * the parent inode and child inode.
1911  *
1912  * record		= record in question (*rec in below)
1913  * record->ip		= parent inode (*pip in below)
1914  * record->target_ip	= child inode (*ip in below)
1915  *
1916  * *pip--------------\
1917  *    ^               \rec_tree
1918  *     \               \
1919  *      \ip            /\\\\\ rbtree of recs from parent inode's view
1920  *       \            //\\\\\\
1921  *        \          / ........
1922  *         \        /
1923  *          \------*rec------target_ip------>*ip
1924  *               ...target_entry<----...----->target_list<---...
1925  *                                            list of recs from inode's view
1926  *
1927  * We are asked to recurse upwards and convert the record from SETUP
1928  * to FLUSH if possible.
1929  *
1930  * Return 1 if the record gives us connectivity
1931  *
1932  * Return 0 if the record is not relevant
1933  *
1934  * Return -1 if we can't resolve the dependancy and there is no connectivity.
1935  */
1936 static int
1937 hammer_setup_parent_inodes_helper(hammer_record_t record, int depth,
1938 				  hammer_flush_group_t flg)
1939 {
1940 	hammer_inode_t pip;
1941 	int good;
1942 
1943 	KKASSERT(record->flush_state != HAMMER_FST_IDLE);
1944 	pip = record->ip;
1945 
1946 	/*
1947 	 * If the record is already flushing, is it in our flush group?
1948 	 *
1949 	 * If it is in our flush group but it is a general record or a
1950 	 * delete-on-disk, it does not improve our connectivity (return 0),
1951 	 * and if the target inode is not trying to destroy itself we can't
1952 	 * allow the operation yet anyway (the second return -1).
1953 	 */
1954 	if (record->flush_state == HAMMER_FST_FLUSH) {
1955 		/*
1956 		 * If not in our flush group ask the parent to reflush
1957 		 * us as soon as possible.
1958 		 */
1959 		if (record->flush_group != flg) {
1960 			pip->flags |= HAMMER_INODE_REFLUSH;
1961 			record->target_ip->flags |= HAMMER_INODE_CONN_DOWN;
1962 			return(-1);
1963 		}
1964 
1965 		/*
1966 		 * If in our flush group everything is already set up,
1967 		 * just return whether the record will improve our
1968 		 * visibility or not.
1969 		 */
1970 		if (record->type == HAMMER_MEM_RECORD_ADD)
1971 			return(1);
1972 		return(0);
1973 	}
1974 
1975 	/*
1976 	 * It must be a setup record.  Try to resolve the setup dependancies
1977 	 * by recursing upwards so we can place ip on the flush list.
1978 	 *
1979 	 * Limit ourselves to 20 levels of recursion to avoid blowing out
1980 	 * the kernel stack.  If we hit the recursion limit we can't flush
1981 	 * until the parent flushes.  The parent will flush independantly
1982 	 * on its own and ultimately a deep recursion will be resolved.
1983 	 */
1984 	KKASSERT(record->flush_state == HAMMER_FST_SETUP);
1985 
1986 	good = hammer_setup_parent_inodes(pip, depth + 1, flg);
1987 
1988 	/*
1989 	 * If good < 0 the parent has no connectivity and we cannot safely
1990 	 * flush the directory entry, which also means we can't flush our
1991 	 * ip.  Flag us for downward recursion once the parent's
1992 	 * connectivity is resolved.  Flag the parent for [re]flush or it
1993 	 * may not check for downward recursions.
1994 	 */
1995 	if (good < 0) {
1996 		pip->flags |= HAMMER_INODE_REFLUSH;
1997 		record->target_ip->flags |= HAMMER_INODE_CONN_DOWN;
1998 		return(good);
1999 	}
2000 
2001 	/*
2002 	 * We are go, place the parent inode in a flushing state so we can
2003 	 * place its record in a flushing state.  Note that the parent
2004 	 * may already be flushing.  The record must be in the same flush
2005 	 * group as the parent.
2006 	 */
2007 	if (pip->flush_state != HAMMER_FST_FLUSH)
2008 		hammer_flush_inode_core(pip, flg, HAMMER_FLUSH_RECURSION);
2009 	KKASSERT(pip->flush_state == HAMMER_FST_FLUSH);
2010 
2011 	/*
2012 	 * It is possible for a rename to create a loop in the recursion
2013 	 * and revisit a record.  This will result in the record being
2014 	 * placed in a flush state unexpectedly.  This check deals with
2015 	 * the case.
2016 	 */
2017 	if (record->flush_state == HAMMER_FST_FLUSH) {
2018 		if (record->type == HAMMER_MEM_RECORD_ADD)
2019 			return(1);
2020 		return(0);
2021 	}
2022 
2023 	KKASSERT(record->flush_state == HAMMER_FST_SETUP);
2024 
2025 #if 0
2026 	if (record->type == HAMMER_MEM_RECORD_DEL &&
2027 	    (record->target_ip->flags & (HAMMER_INODE_DELETED|HAMMER_INODE_DELONDISK)) == 0) {
2028 		/*
2029 		 * Regardless of flushing state we cannot sync this path if the
2030 		 * record represents a delete-on-disk but the target inode
2031 		 * is not ready to sync its own deletion.
2032 		 *
2033 		 * XXX need to count effective nlinks to determine whether
2034 		 * the flush is ok, otherwise removing a hardlink will
2035 		 * just leave the DEL record to rot.
2036 		 */
2037 		record->target_ip->flags |= HAMMER_INODE_REFLUSH;
2038 		return(-1);
2039 	} else
2040 #endif
2041 	if (pip->flush_group == flg) {
2042 		/*
2043 		 * Because we have not calculated nlinks yet we can just
2044 		 * set records to the flush state if the parent is in
2045 		 * the same flush group as we are.
2046 		 */
2047 		record->flush_state = HAMMER_FST_FLUSH;
2048 		record->flush_group = flg;
2049 		++record->flush_group->refs;
2050 		hammer_ref(&record->lock);
2051 
2052 		/*
2053 		 * A general directory-add contributes to our visibility.
2054 		 *
2055 		 * Otherwise it is probably a directory-delete or
2056 		 * delete-on-disk record and does not contribute to our
2057 		 * visbility (but we can still flush it).
2058 		 */
2059 		if (record->type == HAMMER_MEM_RECORD_ADD)
2060 			return(1);
2061 		return(0);
2062 	} else {
2063 		/*
2064 		 * If the parent is not in our flush group we cannot
2065 		 * flush this record yet, there is no visibility.
2066 		 * We tell the parent to reflush and mark ourselves
2067 		 * so the parent knows it should flush us too.
2068 		 */
2069 		pip->flags |= HAMMER_INODE_REFLUSH;
2070 		record->target_ip->flags |= HAMMER_INODE_CONN_DOWN;
2071 		return(-1);
2072 	}
2073 }
2074 
2075 /*
2076  * This is the core routine placing an inode into the FST_FLUSH state.
2077  */
2078 static void
2079 hammer_flush_inode_core(hammer_inode_t ip, hammer_flush_group_t flg, int flags)
2080 {
2081 	hammer_mount_t hmp = ip->hmp;
2082 	int go_count;
2083 
2084 	/*
2085 	 * Set flush state and prevent the flusher from cycling into
2086 	 * the next flush group.  Do not place the ip on the list yet.
2087 	 * Inodes not in the idle state get an extra reference.
2088 	 */
2089 	KKASSERT(ip->flush_state != HAMMER_FST_FLUSH);
2090 	if (ip->flush_state == HAMMER_FST_IDLE)
2091 		hammer_ref(&ip->lock);
2092 	ip->flush_state = HAMMER_FST_FLUSH;
2093 	ip->flush_group = flg;
2094 	++hmp->flusher.group_lock;
2095 	++hmp->count_iqueued;
2096 	++hammer_count_iqueued;
2097 	++flg->total_count;
2098 	hammer_redo_fifo_start_flush(ip);
2099 
2100 #if 0
2101 	/*
2102 	 * We need to be able to vfsync/truncate from the backend.
2103 	 *
2104 	 * XXX Any truncation from the backend will acquire the vnode
2105 	 *     independently.
2106 	 */
2107 	KKASSERT((ip->flags & HAMMER_INODE_VHELD) == 0);
2108 	if (ip->vp && (ip->vp->v_flag & VINACTIVE) == 0) {
2109 		ip->flags |= HAMMER_INODE_VHELD;
2110 		vref(ip->vp);
2111 	}
2112 #endif
2113 
2114 	/*
2115 	 * Figure out how many in-memory records we can actually flush
2116 	 * (not including inode meta-data, buffers, etc).
2117 	 */
2118 	KKASSERT((ip->flags & HAMMER_INODE_WOULDBLOCK) == 0);
2119 	if (flags & HAMMER_FLUSH_RECURSION) {
2120 		/*
2121 		 * If this is a upwards recursion we do not want to
2122 		 * recurse down again!
2123 		 */
2124 		go_count = 1;
2125 #if 0
2126 	} else if (ip->flags & HAMMER_INODE_WOULDBLOCK) {
2127 		/*
2128 		 * No new records are added if we must complete a flush
2129 		 * from a previous cycle, but we do have to move the records
2130 		 * from the previous cycle to the current one.
2131 		 */
2132 #if 0
2133 		go_count = RB_SCAN(hammer_rec_rb_tree, &ip->rec_tree, NULL,
2134 				   hammer_syncgrp_child_callback, NULL);
2135 #endif
2136 		go_count = 1;
2137 #endif
2138 	} else {
2139 		/*
2140 		 * Normal flush, scan records and bring them into the flush.
2141 		 * Directory adds and deletes are usually skipped (they are
2142 		 * grouped with the related inode rather then with the
2143 		 * directory).
2144 		 *
2145 		 * go_count can be negative, which means the scan aborted
2146 		 * due to the flush group being over-full and we should
2147 		 * flush what we have.
2148 		 */
2149 		go_count = RB_SCAN(hammer_rec_rb_tree, &ip->rec_tree, NULL,
2150 				   hammer_setup_child_callback, NULL);
2151 	}
2152 
2153 	/*
2154 	 * This is a more involved test that includes go_count.  If we
2155 	 * can't flush, flag the inode and return.  If go_count is 0 we
2156 	 * were are unable to flush any records in our rec_tree and
2157 	 * must ignore the XDIRTY flag.
2158 	 */
2159 	if (go_count == 0) {
2160 		if ((ip->flags & HAMMER_INODE_MODMASK_NOXDIRTY) == 0) {
2161 			--hmp->count_iqueued;
2162 			--hammer_count_iqueued;
2163 
2164 			--flg->total_count;
2165 			ip->flush_state = HAMMER_FST_SETUP;
2166 			ip->flush_group = NULL;
2167 			if (flags & HAMMER_FLUSH_SIGNAL) {
2168 				ip->flags |= HAMMER_INODE_REFLUSH |
2169 					     HAMMER_INODE_RESIGNAL;
2170 			} else {
2171 				ip->flags |= HAMMER_INODE_REFLUSH;
2172 			}
2173 #if 0
2174 			if (ip->flags & HAMMER_INODE_VHELD) {
2175 				ip->flags &= ~HAMMER_INODE_VHELD;
2176 				vrele(ip->vp);
2177 			}
2178 #endif
2179 
2180 			/*
2181 			 * REFLUSH is needed to trigger dependancy wakeups
2182 			 * when an inode is in SETUP.
2183 			 */
2184 			ip->flags |= HAMMER_INODE_REFLUSH;
2185 			if (--hmp->flusher.group_lock == 0)
2186 				wakeup(&hmp->flusher.group_lock);
2187 			return;
2188 		}
2189 	}
2190 
2191 	/*
2192 	 * Snapshot the state of the inode for the backend flusher.
2193 	 *
2194 	 * We continue to retain save_trunc_off even when all truncations
2195 	 * have been resolved as an optimization to determine if we can
2196 	 * skip the B-Tree lookup for overwrite deletions.
2197 	 *
2198 	 * NOTE: The DELETING flag is a mod flag, but it is also sticky,
2199 	 * and stays in ip->flags.  Once set, it stays set until the
2200 	 * inode is destroyed.
2201 	 */
2202 	if (ip->flags & HAMMER_INODE_TRUNCATED) {
2203 		KKASSERT((ip->sync_flags & HAMMER_INODE_TRUNCATED) == 0);
2204 		ip->sync_trunc_off = ip->trunc_off;
2205 		ip->trunc_off = 0x7FFFFFFFFFFFFFFFLL;
2206 		ip->flags &= ~HAMMER_INODE_TRUNCATED;
2207 		ip->sync_flags |= HAMMER_INODE_TRUNCATED;
2208 
2209 		/*
2210 		 * The save_trunc_off used to cache whether the B-Tree
2211 		 * holds any records past that point is not used until
2212 		 * after the truncation has succeeded, so we can safely
2213 		 * set it now.
2214 		 */
2215 		if (ip->save_trunc_off > ip->sync_trunc_off)
2216 			ip->save_trunc_off = ip->sync_trunc_off;
2217 	}
2218 	ip->sync_flags |= (ip->flags & HAMMER_INODE_MODMASK &
2219 			   ~HAMMER_INODE_TRUNCATED);
2220 	ip->sync_ino_leaf = ip->ino_leaf;
2221 	ip->sync_ino_data = ip->ino_data;
2222 	ip->flags &= ~HAMMER_INODE_MODMASK | HAMMER_INODE_TRUNCATED;
2223 
2224 	/*
2225 	 * The flusher list inherits our inode and reference.
2226 	 */
2227 	KKASSERT(flg->running == 0);
2228 	RB_INSERT(hammer_fls_rb_tree, &flg->flush_tree, ip);
2229 	if (--hmp->flusher.group_lock == 0)
2230 		wakeup(&hmp->flusher.group_lock);
2231 
2232 	/*
2233 	 * Auto-flush the group if it grows too large.  Make sure the
2234 	 * inode reclaim wait pipeline continues to work.
2235 	 */
2236 	if (flg->total_count >= hammer_autoflush ||
2237 	    flg->total_count >= hammer_limit_reclaims / 4) {
2238 		if (hmp->fill_flush_group == flg)
2239 			hmp->fill_flush_group = TAILQ_NEXT(flg, flush_entry);
2240 		hammer_flusher_async(hmp, flg);
2241 	}
2242 }
2243 
2244 /*
2245  * Callback for scan of ip->rec_tree.  Try to include each record in our
2246  * flush.  ip->flush_group has been set but the inode has not yet been
2247  * moved into a flushing state.
2248  *
2249  * If we get stuck on a record we have to set HAMMER_INODE_REFLUSH on
2250  * both inodes.
2251  *
2252  * We return 1 for any record placed or found in FST_FLUSH, which prevents
2253  * the caller from shortcutting the flush.
2254  */
2255 static int
2256 hammer_setup_child_callback(hammer_record_t rec, void *data)
2257 {
2258 	hammer_flush_group_t flg;
2259 	hammer_inode_t target_ip;
2260 	hammer_inode_t ip;
2261 	int r;
2262 
2263 	/*
2264 	 * Records deleted or committed by the backend are ignored.
2265 	 * Note that the flush detects deleted frontend records at
2266 	 * multiple points to deal with races.  This is just the first
2267 	 * line of defense.  The only time HAMMER_RECF_DELETED_FE cannot
2268 	 * be set is when HAMMER_RECF_INTERLOCK_BE is set, because it
2269 	 * messes up link-count calculations.
2270 	 *
2271 	 * NOTE: Don't get confused between record deletion and, say,
2272 	 * directory entry deletion.  The deletion of a directory entry
2273 	 * which is on-media has nothing to do with the record deletion
2274 	 * flags.
2275 	 */
2276 	if (rec->flags & (HAMMER_RECF_DELETED_FE | HAMMER_RECF_DELETED_BE |
2277 			  HAMMER_RECF_COMMITTED)) {
2278 		if (rec->flush_state == HAMMER_FST_FLUSH) {
2279 			KKASSERT(rec->flush_group == rec->ip->flush_group);
2280 			r = 1;
2281 		} else {
2282 			r = 0;
2283 		}
2284 		return(r);
2285 	}
2286 
2287 	/*
2288 	 * If the record is in an idle state it has no dependancies and
2289 	 * can be flushed.
2290 	 */
2291 	ip = rec->ip;
2292 	flg = ip->flush_group;
2293 	r = 0;
2294 
2295 	switch(rec->flush_state) {
2296 	case HAMMER_FST_IDLE:
2297 		/*
2298 		 * The record has no setup dependancy, we can flush it.
2299 		 */
2300 		KKASSERT(rec->target_ip == NULL);
2301 		rec->flush_state = HAMMER_FST_FLUSH;
2302 		rec->flush_group = flg;
2303 		++flg->refs;
2304 		hammer_ref(&rec->lock);
2305 		r = 1;
2306 		break;
2307 	case HAMMER_FST_SETUP:
2308 		/*
2309 		 * The record has a setup dependancy.  These are typically
2310 		 * directory entry adds and deletes.  Such entries will be
2311 		 * flushed when their inodes are flushed so we do not
2312 		 * usually have to add them to the flush here.  However,
2313 		 * if the target_ip has set HAMMER_INODE_CONN_DOWN then
2314 		 * it is asking us to flush this record (and it).
2315 		 */
2316 		target_ip = rec->target_ip;
2317 		KKASSERT(target_ip != NULL);
2318 		KKASSERT(target_ip->flush_state != HAMMER_FST_IDLE);
2319 
2320 		/*
2321 		 * If the target IP is already flushing in our group
2322 		 * we could associate the record, but target_ip has
2323 		 * already synced ino_data to sync_ino_data and we
2324 		 * would also have to adjust nlinks.   Plus there are
2325 		 * ordering issues for adds and deletes.
2326 		 *
2327 		 * Reflush downward if this is an ADD, and upward if
2328 		 * this is a DEL.
2329 		 */
2330 		if (target_ip->flush_state == HAMMER_FST_FLUSH) {
2331 			if (rec->type == HAMMER_MEM_RECORD_ADD)
2332 				ip->flags |= HAMMER_INODE_REFLUSH;
2333 			else
2334 				target_ip->flags |= HAMMER_INODE_REFLUSH;
2335 			break;
2336 		}
2337 
2338 		/*
2339 		 * Target IP is not yet flushing.  This can get complex
2340 		 * because we have to be careful about the recursion.
2341 		 *
2342 		 * Directories create an issue for us in that if a flush
2343 		 * of a directory is requested the expectation is to flush
2344 		 * any pending directory entries, but this will cause the
2345 		 * related inodes to recursively flush as well.  We can't
2346 		 * really defer the operation so just get as many as we
2347 		 * can and
2348 		 */
2349 #if 0
2350 		if ((target_ip->flags & HAMMER_INODE_RECLAIM) == 0 &&
2351 		    (target_ip->flags & HAMMER_INODE_CONN_DOWN) == 0) {
2352 			/*
2353 			 * We aren't reclaiming and the target ip was not
2354 			 * previously prevented from flushing due to this
2355 			 * record dependancy.  Do not flush this record.
2356 			 */
2357 			/*r = 0;*/
2358 		} else
2359 #endif
2360 		if (flg->total_count + flg->refs >
2361 			   ip->hmp->undo_rec_limit) {
2362 			/*
2363 			 * Our flush group is over-full and we risk blowing
2364 			 * out the UNDO FIFO.  Stop the scan, flush what we
2365 			 * have, then reflush the directory.
2366 			 *
2367 			 * The directory may be forced through multiple
2368 			 * flush groups before it can be completely
2369 			 * flushed.
2370 			 */
2371 			ip->flags |= HAMMER_INODE_RESIGNAL |
2372 				     HAMMER_INODE_REFLUSH;
2373 			r = -1;
2374 		} else if (rec->type == HAMMER_MEM_RECORD_ADD) {
2375 			/*
2376 			 * If the target IP is not flushing we can force
2377 			 * it to flush, even if it is unable to write out
2378 			 * any of its own records we have at least one in
2379 			 * hand that we CAN deal with.
2380 			 */
2381 			rec->flush_state = HAMMER_FST_FLUSH;
2382 			rec->flush_group = flg;
2383 			++flg->refs;
2384 			hammer_ref(&rec->lock);
2385 			hammer_flush_inode_core(target_ip, flg,
2386 						HAMMER_FLUSH_RECURSION);
2387 			r = 1;
2388 		} else {
2389 			/*
2390 			 * General or delete-on-disk record.
2391 			 *
2392 			 * XXX this needs help.  If a delete-on-disk we could
2393 			 * disconnect the target.  If the target has its own
2394 			 * dependancies they really need to be flushed.
2395 			 *
2396 			 * XXX
2397 			 */
2398 			rec->flush_state = HAMMER_FST_FLUSH;
2399 			rec->flush_group = flg;
2400 			++flg->refs;
2401 			hammer_ref(&rec->lock);
2402 			hammer_flush_inode_core(target_ip, flg,
2403 						HAMMER_FLUSH_RECURSION);
2404 			r = 1;
2405 		}
2406 		break;
2407 	case HAMMER_FST_FLUSH:
2408 		/*
2409 		 * The record could be part of a previous flush group if the
2410 		 * inode is a directory (the record being a directory entry).
2411 		 * Once the flush group was closed a hammer_test_inode()
2412 		 * function can cause a new flush group to be setup, placing
2413 		 * the directory inode itself in a new flush group.
2414 		 *
2415 		 * When associated with a previous flush group we count it
2416 		 * as if it were in our current flush group, since it will
2417 		 * effectively be flushed by the time we flush our current
2418 		 * flush group.
2419 		 */
2420 		KKASSERT(
2421 		    rec->ip->ino_data.obj_type == HAMMER_OBJTYPE_DIRECTORY ||
2422 		    rec->flush_group == flg);
2423 		r = 1;
2424 		break;
2425 	}
2426 	return(r);
2427 }
2428 
2429 #if 0
2430 /*
2431  * This version just moves records already in a flush state to the new
2432  * flush group and that is it.
2433  */
2434 static int
2435 hammer_syncgrp_child_callback(hammer_record_t rec, void *data)
2436 {
2437 	hammer_inode_t ip = rec->ip;
2438 
2439 	switch(rec->flush_state) {
2440 	case HAMMER_FST_FLUSH:
2441 		KKASSERT(rec->flush_group == ip->flush_group);
2442 		break;
2443 	default:
2444 		break;
2445 	}
2446 	return(0);
2447 }
2448 #endif
2449 
2450 /*
2451  * Wait for a previously queued flush to complete.
2452  *
2453  * If a critical error occured we don't try to wait.
2454  */
2455 void
2456 hammer_wait_inode(hammer_inode_t ip)
2457 {
2458 	/*
2459 	 * The inode can be in a SETUP state in which case RESIGNAL
2460 	 * should be set.  If RESIGNAL is not set then the previous
2461 	 * flush completed and a later operation placed the inode
2462 	 * in a passive setup state again, so we're done.
2463 	 *
2464 	 * The inode can be in a FLUSH state in which case we
2465 	 * can just wait for completion.
2466 	 */
2467 	while (ip->flush_state == HAMMER_FST_FLUSH ||
2468 	    (ip->flush_state == HAMMER_FST_SETUP &&
2469 	     (ip->flags & HAMMER_INODE_RESIGNAL))) {
2470 		/*
2471 		 * Don't try to flush on a critical error
2472 		 */
2473 		if (ip->hmp->flags & HAMMER_MOUNT_CRITICAL_ERROR)
2474 			break;
2475 
2476 		/*
2477 		 * If the inode was already being flushed its flg
2478 		 * may not have been queued to the backend.  We
2479 		 * have to make sure it gets queued or we can wind
2480 		 * up blocked or deadlocked (particularly if we are
2481 		 * the vnlru thread).
2482 		 */
2483 		if (ip->flush_state == HAMMER_FST_FLUSH) {
2484 			KKASSERT(ip->flush_group);
2485 			if (ip->flush_group->closed == 0) {
2486 				if (hammer_debug_inode) {
2487 					hkprintf("debug: forcing "
2488 						"async flush ip %016jx\n",
2489 						(intmax_t)ip->obj_id);
2490 				}
2491 				hammer_flusher_async(ip->hmp, ip->flush_group);
2492 				continue; /* retest */
2493 			}
2494 		}
2495 
2496 		/*
2497 		 * In a flush state with the flg queued to the backend
2498 		 * or in a setup state with RESIGNAL set, we can safely
2499 		 * wait.
2500 		 */
2501 		ip->flags |= HAMMER_INODE_FLUSHW;
2502 		tsleep(&ip->flags, 0, "hmrwin", 0);
2503 	}
2504 
2505 #if 0
2506 	/*
2507 	 * The inode may have been in a passive setup state,
2508 	 * call flush to make sure we get signaled.
2509 	 */
2510 	if (ip->flush_state == HAMMER_FST_SETUP)
2511 		hammer_flush_inode(ip, HAMMER_FLUSH_SIGNAL);
2512 #endif
2513 
2514 }
2515 
2516 /*
2517  * Called by the backend code when a flush has been completed.
2518  * The inode has already been removed from the flush list.
2519  *
2520  * A pipelined flush can occur, in which case we must re-enter the
2521  * inode on the list and re-copy its fields.
2522  */
2523 void
2524 hammer_flush_inode_done(hammer_inode_t ip, int error)
2525 {
2526 	hammer_mount_t hmp;
2527 	int dorel;
2528 
2529 	KKASSERT(ip->flush_state == HAMMER_FST_FLUSH);
2530 
2531 	hmp = ip->hmp;
2532 
2533 	/*
2534 	 * Auto-reflush if the backend could not completely flush
2535 	 * the inode.  This fixes a case where a deferred buffer flush
2536 	 * could cause fsync to return early.
2537 	 */
2538 	if (ip->sync_flags & HAMMER_INODE_MODMASK)
2539 		ip->flags |= HAMMER_INODE_REFLUSH;
2540 
2541 	/*
2542 	 * Merge left-over flags back into the frontend and fix the state.
2543 	 * Incomplete truncations are retained by the backend.
2544 	 */
2545 	ip->error = error;
2546 	ip->flags |= ip->sync_flags & ~HAMMER_INODE_TRUNCATED;
2547 	ip->sync_flags &= HAMMER_INODE_TRUNCATED;
2548 
2549 	/*
2550 	 * The backend may have adjusted nlinks, so if the adjusted nlinks
2551 	 * does not match the fronttend set the frontend's DDIRTY flag again.
2552 	 */
2553 	if (ip->ino_data.nlinks != ip->sync_ino_data.nlinks)
2554 		ip->flags |= HAMMER_INODE_DDIRTY;
2555 
2556 	/*
2557 	 * Fix up the dirty buffer status.
2558 	 */
2559 	if (ip->vp && RB_ROOT(&ip->vp->v_rbdirty_tree)) {
2560 		ip->flags |= HAMMER_INODE_BUFS;
2561 	}
2562 	hammer_redo_fifo_end_flush(ip);
2563 
2564 	/*
2565 	 * Re-set the XDIRTY flag if some of the inode's in-memory records
2566 	 * could not be flushed.
2567 	 */
2568 	KKASSERT((RB_EMPTY(&ip->rec_tree) &&
2569 		  (ip->flags & HAMMER_INODE_XDIRTY) == 0) ||
2570 		 (!RB_EMPTY(&ip->rec_tree) &&
2571 		  (ip->flags & HAMMER_INODE_XDIRTY) != 0));
2572 
2573 	/*
2574 	 * Do not lose track of inodes which no longer have vnode
2575 	 * assocations, otherwise they may never get flushed again.
2576 	 *
2577 	 * The reflush flag can be set superfluously, causing extra pain
2578 	 * for no reason.  If the inode is no longer modified it no longer
2579 	 * needs to be flushed.
2580 	 */
2581 	if (ip->flags & HAMMER_INODE_MODMASK) {
2582 		if (ip->vp == NULL)
2583 			ip->flags |= HAMMER_INODE_REFLUSH;
2584 	} else {
2585 		ip->flags &= ~HAMMER_INODE_REFLUSH;
2586 	}
2587 
2588 	/*
2589 	 * The fs token is held but the inode lock is not held.  Because this
2590 	 * is a backend flush it is possible that the vnode has no references
2591 	 * and cause a reclaim race inside vsetisdirty() if/when it blocks.
2592 	 *
2593 	 * Therefore, we must lock the inode around this particular dirtying
2594 	 * operation.  We don't have to around other dirtying operations
2595 	 * where the vnode is implicitly or explicitly held.
2596 	 */
2597 	if (ip->flags & HAMMER_INODE_MODMASK) {
2598 		hammer_lock_ex(&ip->lock);
2599 		hammer_inode_dirty(ip);
2600 		hammer_unlock(&ip->lock);
2601 	}
2602 
2603 	/*
2604 	 * Adjust the flush state.
2605 	 */
2606 	if (ip->flags & HAMMER_INODE_WOULDBLOCK) {
2607 		/*
2608 		 * We were unable to flush out all our records, leave the
2609 		 * inode in a flush state and in the current flush group.
2610 		 * The flush group will be re-run.
2611 		 *
2612 		 * This occurs if the UNDO block gets too full or there is
2613 		 * too much dirty meta-data and allows the flusher to
2614 		 * finalize the UNDO block and then re-flush.
2615 		 */
2616 		ip->flags &= ~HAMMER_INODE_WOULDBLOCK;
2617 		dorel = 0;
2618 	} else {
2619 		/*
2620 		 * Remove from the flush_group
2621 		 */
2622 		RB_REMOVE(hammer_fls_rb_tree, &ip->flush_group->flush_tree, ip);
2623 		ip->flush_group = NULL;
2624 
2625 #if 0
2626 		/*
2627 		 * Clean up the vnode ref and tracking counts.
2628 		 */
2629 		if (ip->flags & HAMMER_INODE_VHELD) {
2630 			ip->flags &= ~HAMMER_INODE_VHELD;
2631 			vrele(ip->vp);
2632 		}
2633 #endif
2634 		--hmp->count_iqueued;
2635 		--hammer_count_iqueued;
2636 
2637 		/*
2638 		 * And adjust the state.
2639 		 */
2640 		if (TAILQ_EMPTY(&ip->target_list) && RB_EMPTY(&ip->rec_tree)) {
2641 			ip->flush_state = HAMMER_FST_IDLE;
2642 			dorel = 1;
2643 		} else {
2644 			ip->flush_state = HAMMER_FST_SETUP;
2645 			dorel = 0;
2646 		}
2647 
2648 		/*
2649 		 * If the frontend is waiting for a flush to complete,
2650 		 * wake it up.
2651 		 */
2652 		if (ip->flags & HAMMER_INODE_FLUSHW) {
2653 			ip->flags &= ~HAMMER_INODE_FLUSHW;
2654 			wakeup(&ip->flags);
2655 		}
2656 
2657 		/*
2658 		 * If the frontend made more changes and requested another
2659 		 * flush, then try to get it running.
2660 		 *
2661 		 * Reflushes are aborted when the inode is errored out.
2662 		 */
2663 		if (ip->flags & HAMMER_INODE_REFLUSH) {
2664 			ip->flags &= ~HAMMER_INODE_REFLUSH;
2665 			if (ip->flags & HAMMER_INODE_RESIGNAL) {
2666 				ip->flags &= ~HAMMER_INODE_RESIGNAL;
2667 				hammer_flush_inode(ip, HAMMER_FLUSH_SIGNAL);
2668 			} else {
2669 				hammer_flush_inode(ip, 0);
2670 			}
2671 		}
2672 	}
2673 
2674 	/*
2675 	 * If we have no parent dependancies we can clear CONN_DOWN
2676 	 */
2677 	if (TAILQ_EMPTY(&ip->target_list))
2678 		ip->flags &= ~HAMMER_INODE_CONN_DOWN;
2679 
2680 	/*
2681 	 * If the inode is now clean drop the space reservation.
2682 	 */
2683 	if ((ip->flags & HAMMER_INODE_MODMASK) == 0 &&
2684 	    (ip->flags & HAMMER_INODE_RSV_INODES)) {
2685 		ip->flags &= ~HAMMER_INODE_RSV_INODES;
2686 		--hmp->rsv_inodes;
2687 	}
2688 
2689 	ip->flags &= ~HAMMER_INODE_SLAVEFLUSH;
2690 
2691 	if (dorel)
2692 		hammer_rel_inode(ip, 0);
2693 }
2694 
2695 /*
2696  * Called from hammer_sync_inode() to synchronize in-memory records
2697  * to the media.
2698  */
2699 static int
2700 hammer_sync_record_callback(hammer_record_t record, void *data)
2701 {
2702 	hammer_cursor_t cursor = data;
2703 	hammer_transaction_t trans = cursor->trans;
2704 	hammer_mount_t hmp = trans->hmp;
2705 	int error;
2706 
2707 	/*
2708 	 * Skip records that do not belong to the current flush.
2709 	 */
2710 	++hammer_stats_record_iterations;
2711 	if (record->flush_state != HAMMER_FST_FLUSH)
2712 		return(0);
2713 
2714 	if (record->flush_group != record->ip->flush_group) {
2715 		hdkprintf("rec %p ip %p bad flush group %p %p\n",
2716 			record,
2717 			record->ip,
2718 			record->flush_group,
2719 			record->ip->flush_group);
2720 		if (hammer_debug_critical)
2721 			Debugger("blah2");
2722 		return(0);
2723 	}
2724 	KKASSERT(record->flush_group == record->ip->flush_group);
2725 
2726 	/*
2727 	 * Interlock the record using the BE flag.  Once BE is set the
2728 	 * frontend cannot change the state of FE.
2729 	 *
2730 	 * NOTE: If FE is set prior to us setting BE we still sync the
2731 	 * record out, but the flush completion code converts it to
2732 	 * a delete-on-disk record instead of destroying it.
2733 	 */
2734 	KKASSERT((record->flags & HAMMER_RECF_INTERLOCK_BE) == 0);
2735 	record->flags |= HAMMER_RECF_INTERLOCK_BE;
2736 
2737 	/*
2738 	 * The backend has already disposed of the record.
2739 	 */
2740 	if (record->flags & (HAMMER_RECF_DELETED_BE | HAMMER_RECF_COMMITTED)) {
2741 		error = 0;
2742 		goto done;
2743 	}
2744 
2745 	/*
2746 	 * If the whole inode is being deleted and all on-disk records will
2747 	 * be deleted very soon, we can't sync any new records to disk
2748 	 * because they will be deleted in the same transaction they were
2749 	 * created in (delete_tid == create_tid), which will assert.
2750 	 *
2751 	 * XXX There may be a case with RECORD_ADD with DELETED_FE set
2752 	 * that we currently panic on.
2753 	 */
2754 	if (record->ip->sync_flags & HAMMER_INODE_DELETING) {
2755 		switch(record->type) {
2756 		case HAMMER_MEM_RECORD_DATA:
2757 			/*
2758 			 * We don't have to do anything, if the record was
2759 			 * committed the space will have been accounted for
2760 			 * in the blockmap.
2761 			 */
2762 			/* fall through */
2763 		case HAMMER_MEM_RECORD_GENERAL:
2764 			/*
2765 			 * Set deleted-by-backend flag.  Do not set the
2766 			 * backend committed flag, because we are throwing
2767 			 * the record away.
2768 			 */
2769 			record->flags |= HAMMER_RECF_DELETED_BE;
2770 			++record->ip->rec_generation;
2771 			error = 0;
2772 			goto done;
2773 		case HAMMER_MEM_RECORD_ADD:
2774 			hpanic("illegal add during inode deletion record %p",
2775 				record);
2776 			break; /* NOT REACHED */
2777 		case HAMMER_MEM_RECORD_INODE:
2778 			hpanic("attempt to sync inode record %p?", record);
2779 			break; /* NOT REACHED */
2780 		case HAMMER_MEM_RECORD_DEL:
2781 			/*
2782 			 * Follow through and issue the on-disk deletion
2783 			 */
2784 			break;
2785 		}
2786 	}
2787 
2788 	/*
2789 	 * If DELETED_FE is set special handling is needed for directory
2790 	 * entries.  Dependant pieces related to the directory entry may
2791 	 * have already been synced to disk.  If this occurs we have to
2792 	 * sync the directory entry and then change the in-memory record
2793 	 * from an ADD to a DELETE to cover the fact that it's been
2794 	 * deleted by the frontend.
2795 	 *
2796 	 * A directory delete covering record (MEM_RECORD_DEL) can never
2797 	 * be deleted by the frontend.
2798 	 *
2799 	 * Any other record type (aka DATA) can be deleted by the frontend.
2800 	 * XXX At the moment the flusher must skip it because there may
2801 	 * be another data record in the flush group for the same block,
2802 	 * meaning that some frontend data changes can leak into the backend's
2803 	 * synchronization point.
2804 	 */
2805 	if (record->flags & HAMMER_RECF_DELETED_FE) {
2806 		if (record->type == HAMMER_MEM_RECORD_ADD) {
2807 			/*
2808 			 * Convert a front-end deleted directory-add to
2809 			 * a directory-delete entry later.
2810 			 */
2811 			record->flags |= HAMMER_RECF_CONVERT_DELETE;
2812 		} else {
2813 			/*
2814 			 * Dispose of the record (race case).  Mark as
2815 			 * deleted by backend (and not committed).
2816 			 */
2817 			KKASSERT(record->type != HAMMER_MEM_RECORD_DEL);
2818 			record->flags |= HAMMER_RECF_DELETED_BE;
2819 			++record->ip->rec_generation;
2820 			error = 0;
2821 			goto done;
2822 		}
2823 	}
2824 
2825 	/*
2826 	 * Assign the create_tid for new records.  Deletions already
2827 	 * have the record's entire key properly set up.
2828 	 */
2829 	if (record->type != HAMMER_MEM_RECORD_DEL) {
2830 		record->leaf.base.create_tid = trans->tid;
2831 		record->leaf.create_ts = trans->time32;
2832 	}
2833 
2834 	/*
2835 	 * This actually moves the record to the on-media B-Tree.  We
2836 	 * must also generate REDO_TERM entries in the UNDO/REDO FIFO
2837 	 * indicating that the related REDO_WRITE(s) have been committed.
2838 	 *
2839 	 * During recovery any REDO_TERM's within the nominal recovery span
2840 	 * are ignored since the related meta-data is being undone, causing
2841 	 * any matching REDO_WRITEs to execute.  The REDO_TERMs outside
2842 	 * the nominal recovery span will match against REDO_WRITEs and
2843 	 * prevent them from being executed (because the meta-data has
2844 	 * already been synchronized).
2845 	 */
2846 	if (record->flags & HAMMER_RECF_REDO) {
2847 		KKASSERT(record->type == HAMMER_MEM_RECORD_DATA);
2848 		hammer_generate_redo(trans, record->ip,
2849 				     record->leaf.base.key -
2850 					 record->leaf.data_len,
2851 				     HAMMER_REDO_TERM_WRITE,
2852 				     NULL,
2853 				     record->leaf.data_len);
2854 	}
2855 
2856 	for (;;) {
2857 		error = hammer_ip_sync_record_cursor(cursor, record);
2858 		if (error != EDEADLK)
2859 			break;
2860 		hammer_done_cursor(cursor);
2861 		error = hammer_init_cursor(trans, cursor, &record->ip->cache[0],
2862 					   record->ip);
2863 		if (error)
2864 			break;
2865 	}
2866 	record->flags &= ~HAMMER_RECF_CONVERT_DELETE;
2867 
2868 	if (error)
2869 		error = -error;
2870 done:
2871 	hammer_flush_record_done(record, error);
2872 
2873 	/*
2874 	 * Do partial finalization if we have built up too many dirty
2875 	 * buffers.  Otherwise a buffer cache deadlock can occur when
2876 	 * doing things like creating tens of thousands of tiny files.
2877 	 *
2878 	 * We must release our cursor lock to avoid a 3-way deadlock
2879 	 * due to the exclusive sync lock the finalizer must get.
2880 	 *
2881 	 * WARNING: See warnings in hammer_unlock_cursor() function.
2882 	 */
2883         if (hammer_flusher_meta_limit(hmp) ||
2884 	    vm_page_count_severe()) {
2885 		hammer_unlock_cursor(cursor);
2886                 hammer_flusher_finalize(trans, 0);
2887 		hammer_lock_cursor(cursor);
2888 	}
2889 	return(error);
2890 }
2891 
2892 /*
2893  * Backend function called by the flusher to sync an inode to media.
2894  */
2895 int
2896 hammer_sync_inode(hammer_transaction_t trans, hammer_inode_t ip)
2897 {
2898 	struct hammer_cursor cursor;
2899 	hammer_node_t tmp_node;
2900 	hammer_record_t depend;
2901 	hammer_record_t next;
2902 	int error, tmp_error;
2903 	uint64_t nlinks;
2904 
2905 	if ((ip->sync_flags & HAMMER_INODE_MODMASK) == 0)
2906 		return(0);
2907 
2908 	error = hammer_init_cursor(trans, &cursor, &ip->cache[1], ip);
2909 	if (error)
2910 		goto done;
2911 
2912 	/*
2913 	 * Any directory records referencing this inode which are not in
2914 	 * our current flush group must adjust our nlink count for the
2915 	 * purposes of synchronizating to disk.
2916 	 *
2917 	 * Records which are in our flush group can be unlinked from our
2918 	 * inode now, potentially allowing the inode to be physically
2919 	 * deleted.
2920 	 *
2921 	 * This cannot block.
2922 	 */
2923 	nlinks = ip->ino_data.nlinks;
2924 	next = TAILQ_FIRST(&ip->target_list);
2925 	while ((depend = next) != NULL) {
2926 		next = TAILQ_NEXT(depend, target_entry);
2927 		if (depend->flush_state == HAMMER_FST_FLUSH &&
2928 		    depend->flush_group == ip->flush_group) {
2929 			/*
2930 			 * If this is an ADD that was deleted by the frontend
2931 			 * the frontend nlinks count will have already been
2932 			 * decremented, but the backend is going to sync its
2933 			 * directory entry and must account for it.  The
2934 			 * record will be converted to a delete-on-disk when
2935 			 * it gets synced.
2936 			 *
2937 			 * If the ADD was not deleted by the frontend we
2938 			 * can remove the dependancy from our target_list.
2939 			 */
2940 			if (depend->flags & HAMMER_RECF_DELETED_FE) {
2941 				++nlinks;
2942 			} else {
2943 				TAILQ_REMOVE(&ip->target_list, depend,
2944 					     target_entry);
2945 				depend->target_ip = NULL;
2946 			}
2947 		} else if ((depend->flags & HAMMER_RECF_DELETED_FE) == 0) {
2948 			/*
2949 			 * Not part of our flush group and not deleted by
2950 			 * the front-end, adjust the link count synced to
2951 			 * the media (undo what the frontend did when it
2952 			 * queued the record).
2953 			 */
2954 			KKASSERT((depend->flags & HAMMER_RECF_DELETED_BE) == 0);
2955 			switch(depend->type) {
2956 			case HAMMER_MEM_RECORD_ADD:
2957 				--nlinks;
2958 				break;
2959 			case HAMMER_MEM_RECORD_DEL:
2960 				++nlinks;
2961 				break;
2962 			default:
2963 				break;
2964 			}
2965 		}
2966 	}
2967 
2968 	/*
2969 	 * Set dirty if we had to modify the link count.
2970 	 */
2971 	if (ip->sync_ino_data.nlinks != nlinks) {
2972 		KKASSERT((int64_t)nlinks >= 0);
2973 		ip->sync_ino_data.nlinks = nlinks;
2974 		ip->sync_flags |= HAMMER_INODE_DDIRTY;
2975 	}
2976 
2977 	/*
2978 	 * If there is a trunction queued destroy any data past the (aligned)
2979 	 * truncation point.  Userland will have dealt with the buffer
2980 	 * containing the truncation point for us.
2981 	 *
2982 	 * We don't flush pending frontend data buffers until after we've
2983 	 * dealt with the truncation.
2984 	 */
2985 	if (ip->sync_flags & HAMMER_INODE_TRUNCATED) {
2986 		/*
2987 		 * Interlock trunc_off.  The VOP front-end may continue to
2988 		 * make adjustments to it while we are blocked.
2989 		 */
2990 		off_t trunc_off;
2991 		off_t aligned_trunc_off;
2992 		int blkmask;
2993 
2994 		trunc_off = ip->sync_trunc_off;
2995 		blkmask = hammer_blocksize(trunc_off) - 1;
2996 		aligned_trunc_off = (trunc_off + blkmask) & ~(int64_t)blkmask;
2997 
2998 		/*
2999 		 * Delete any whole blocks on-media.  The front-end has
3000 		 * already cleaned out any partial block and made it
3001 		 * pending.  The front-end may have updated trunc_off
3002 		 * while we were blocked so we only use sync_trunc_off.
3003 		 *
3004 		 * This operation can blow out the buffer cache, EWOULDBLOCK
3005 		 * means we were unable to complete the deletion.  The
3006 		 * deletion will update sync_trunc_off in that case.
3007 		 */
3008 		error = hammer_ip_delete_range(&cursor, ip,
3009 						aligned_trunc_off,
3010 						0x7FFFFFFFFFFFFFFFLL, 2);
3011 		if (error == EWOULDBLOCK) {
3012 			ip->flags |= HAMMER_INODE_WOULDBLOCK;
3013 			error = 0;
3014 			goto defer_buffer_flush;
3015 		}
3016 
3017 		if (error)
3018 			goto done;
3019 
3020 		/*
3021 		 * Generate a REDO_TERM_TRUNC entry in the UNDO/REDO FIFO.
3022 		 *
3023 		 * XXX we do this even if we did not previously generate
3024 		 * a REDO_TRUNC record.  This operation may enclosed the
3025 		 * range for multiple prior truncation entries in the REDO
3026 		 * log.
3027 		 */
3028 		if (trans->hmp->version >= HAMMER_VOL_VERSION_FOUR &&
3029 		    (ip->flags & HAMMER_INODE_RDIRTY)) {
3030 			hammer_generate_redo(trans, ip, aligned_trunc_off,
3031 					     HAMMER_REDO_TERM_TRUNC,
3032 					     NULL, 0);
3033 		}
3034 
3035 		/*
3036 		 * Clear the truncation flag on the backend after we have
3037 		 * completed the deletions.  Backend data is now good again
3038 		 * (including new records we are about to sync, below).
3039 		 *
3040 		 * Leave sync_trunc_off intact.  As we write additional
3041 		 * records the backend will update sync_trunc_off.  This
3042 		 * tells the backend whether it can skip the overwrite
3043 		 * test.  This should work properly even when the backend
3044 		 * writes full blocks where the truncation point straddles
3045 		 * the block because the comparison is against the base
3046 		 * offset of the record.
3047 		 */
3048 		ip->sync_flags &= ~HAMMER_INODE_TRUNCATED;
3049 		/* ip->sync_trunc_off = 0x7FFFFFFFFFFFFFFFLL; */
3050 	} else {
3051 		error = 0;
3052 	}
3053 
3054 	/*
3055 	 * Now sync related records.  These will typically be directory
3056 	 * entries, records tracking direct-writes, or delete-on-disk records.
3057 	 */
3058 	if (error == 0) {
3059 		tmp_error = RB_SCAN(hammer_rec_rb_tree, &ip->rec_tree, NULL,
3060 				    hammer_sync_record_callback, &cursor);
3061 		if (tmp_error < 0)
3062 			tmp_error = -error;
3063 		if (tmp_error)
3064 			error = tmp_error;
3065 	}
3066 	hammer_cache_node(&ip->cache[1], cursor.node);
3067 
3068 	/*
3069 	 * Re-seek for inode update, assuming our cache hasn't been ripped
3070 	 * out from under us.
3071 	 */
3072 	if (error == 0) {
3073 		tmp_node = hammer_ref_node_safe(trans, &ip->cache[0], &error);
3074 		if (tmp_node) {
3075 			hammer_cursor_downgrade(&cursor);
3076 			hammer_lock_sh(&tmp_node->lock);
3077 			if ((tmp_node->flags & HAMMER_NODE_DELETED) == 0)
3078 				hammer_cursor_seek(&cursor, tmp_node, 0);
3079 			hammer_unlock(&tmp_node->lock);
3080 			hammer_rel_node(tmp_node);
3081 		}
3082 		error = 0;
3083 	}
3084 
3085 	/*
3086 	 * If we are deleting the inode the frontend had better not have
3087 	 * any active references on elements making up the inode.
3088 	 *
3089 	 * The call to hammer_ip_delete_clean() cleans up auxillary records
3090 	 * but not DB or DATA records.  Those must have already been deleted
3091 	 * by the normal truncation mechanic.
3092 	 */
3093 	if (error == 0 && ip->sync_ino_data.nlinks == 0 &&
3094 		RB_EMPTY(&ip->rec_tree)  &&
3095 	    (ip->sync_flags & HAMMER_INODE_DELETING) &&
3096 	    (ip->flags & HAMMER_INODE_DELETED) == 0) {
3097 		int count1 = 0;
3098 
3099 		error = hammer_ip_delete_clean(&cursor, ip, &count1);
3100 		if (error == 0) {
3101 			ip->flags |= HAMMER_INODE_DELETED;
3102 			ip->sync_flags &= ~HAMMER_INODE_DELETING;
3103 			ip->sync_flags &= ~HAMMER_INODE_TRUNCATED;
3104 			KKASSERT(RB_EMPTY(&ip->rec_tree));
3105 
3106 			/*
3107 			 * Set delete_tid in both the frontend and backend
3108 			 * copy of the inode record.  The DELETED flag handles
3109 			 * this, do not set DDIRTY.
3110 			 */
3111 			ip->ino_leaf.base.delete_tid = trans->tid;
3112 			ip->sync_ino_leaf.base.delete_tid = trans->tid;
3113 			ip->ino_leaf.delete_ts = trans->time32;
3114 			ip->sync_ino_leaf.delete_ts = trans->time32;
3115 
3116 
3117 			/*
3118 			 * Adjust the inode count in the volume header
3119 			 */
3120 			hammer_sync_lock_sh(trans);
3121 			if (ip->flags & HAMMER_INODE_ONDISK) {
3122 				hammer_modify_volume_field(trans,
3123 							   trans->rootvol,
3124 							   vol0_stat_inodes);
3125 				--ip->hmp->rootvol->ondisk->vol0_stat_inodes;
3126 				hammer_modify_volume_done(trans->rootvol);
3127 			}
3128 			hammer_sync_unlock(trans);
3129 		}
3130 	}
3131 
3132 	if (error)
3133 		goto done;
3134 	ip->sync_flags &= ~HAMMER_INODE_BUFS;
3135 
3136 defer_buffer_flush:
3137 	/*
3138 	 * Now update the inode's on-disk inode-data and/or on-disk record.
3139 	 * DELETED and ONDISK are managed only in ip->flags.
3140 	 *
3141 	 * In the case of a defered buffer flush we still update the on-disk
3142 	 * inode to satisfy visibility requirements if there happen to be
3143 	 * directory dependancies.
3144 	 */
3145 	switch(ip->flags & (HAMMER_INODE_DELETED | HAMMER_INODE_ONDISK)) {
3146 	case HAMMER_INODE_DELETED|HAMMER_INODE_ONDISK:
3147 		/*
3148 		 * If deleted and on-disk, don't set any additional flags.
3149 		 * the delete flag takes care of things.
3150 		 *
3151 		 * Clear flags which may have been set by the frontend.
3152 		 */
3153 		ip->sync_flags &= ~(HAMMER_INODE_DDIRTY | HAMMER_INODE_XDIRTY |
3154 				    HAMMER_INODE_SDIRTY |
3155 				    HAMMER_INODE_ATIME | HAMMER_INODE_MTIME |
3156 				    HAMMER_INODE_DELETING);
3157 		break;
3158 	case HAMMER_INODE_DELETED:
3159 		/*
3160 		 * Take care of the case where a deleted inode was never
3161 		 * flushed to the disk in the first place.
3162 		 *
3163 		 * Clear flags which may have been set by the frontend.
3164 		 */
3165 		ip->sync_flags &= ~(HAMMER_INODE_DDIRTY | HAMMER_INODE_XDIRTY |
3166 				    HAMMER_INODE_SDIRTY |
3167 				    HAMMER_INODE_ATIME | HAMMER_INODE_MTIME |
3168 				    HAMMER_INODE_DELETING);
3169 		while (RB_ROOT(&ip->rec_tree)) {
3170 			hammer_record_t record = RB_ROOT(&ip->rec_tree);
3171 			hammer_ref(&record->lock);
3172 			KKASSERT(hammer_oneref(&record->lock));
3173 			record->flags |= HAMMER_RECF_DELETED_BE;
3174 			++record->ip->rec_generation;
3175 			hammer_rel_mem_record(record);
3176 		}
3177 		break;
3178 	case HAMMER_INODE_ONDISK:
3179 		/*
3180 		 * If already on-disk, do not set any additional flags.
3181 		 */
3182 		break;
3183 	default:
3184 		/*
3185 		 * If not on-disk and not deleted, set DDIRTY to force
3186 		 * an initial record to be written.
3187 		 *
3188 		 * Also set the create_tid in both the frontend and backend
3189 		 * copy of the inode record.
3190 		 */
3191 		ip->ino_leaf.base.create_tid = trans->tid;
3192 		ip->ino_leaf.create_ts = trans->time32;
3193 		ip->sync_ino_leaf.base.create_tid = trans->tid;
3194 		ip->sync_ino_leaf.create_ts = trans->time32;
3195 		ip->sync_flags |= HAMMER_INODE_DDIRTY;
3196 		break;
3197 	}
3198 
3199 	/*
3200 	 * If DDIRTY or SDIRTY is set, write out a new record.
3201 	 * If the inode is already on-disk the old record is marked as
3202 	 * deleted.
3203 	 *
3204 	 * If DELETED is set hammer_update_inode() will delete the existing
3205 	 * record without writing out a new one.
3206 	 */
3207 	if (ip->flags & HAMMER_INODE_DELETED) {
3208 		error = hammer_update_inode(&cursor, ip);
3209 	} else
3210 	if (!(ip->sync_flags & (HAMMER_INODE_DDIRTY | HAMMER_INODE_SDIRTY)) &&
3211 	    (ip->sync_flags & (HAMMER_INODE_ATIME | HAMMER_INODE_MTIME))) {
3212 		error = hammer_update_itimes(&cursor, ip);
3213 	} else
3214 	if (ip->sync_flags & (HAMMER_INODE_DDIRTY | HAMMER_INODE_SDIRTY |
3215 			      HAMMER_INODE_ATIME | HAMMER_INODE_MTIME)) {
3216 		error = hammer_update_inode(&cursor, ip);
3217 	}
3218 done:
3219 	if (ip->flags & HAMMER_INODE_MODMASK)
3220 		hammer_inode_dirty(ip);
3221 	if (error) {
3222 		hammer_critical_error(ip->hmp, ip, error,
3223 				      "while syncing inode");
3224 	}
3225 	hammer_done_cursor(&cursor);
3226 	return(error);
3227 }
3228 
3229 /*
3230  * This routine is called when the OS is no longer actively referencing
3231  * the inode (but might still be keeping it cached), or when releasing
3232  * the last reference to an inode.
3233  *
3234  * At this point if the inode's nlinks count is zero we want to destroy
3235  * it, which may mean destroying it on-media too.
3236  */
3237 void
3238 hammer_inode_unloadable_check(hammer_inode_t ip, int getvp)
3239 {
3240 	struct vnode *vp;
3241 
3242 	/*
3243 	 * Set the DELETING flag when the link count drops to 0 and the
3244 	 * OS no longer has any opens on the inode.
3245 	 *
3246 	 * The backend will clear DELETING (a mod flag) and set DELETED
3247 	 * (a state flag) when it is actually able to perform the
3248 	 * operation.
3249 	 *
3250 	 * Don't reflag the deletion if the flusher is currently syncing
3251 	 * one that was already flagged.  A previously set DELETING flag
3252 	 * may bounce around flags and sync_flags until the operation is
3253 	 * completely done.
3254 	 *
3255 	 * Do not attempt to modify a snapshot inode (one set to read-only).
3256 	 */
3257 	if (ip->ino_data.nlinks == 0 &&
3258 	    ((ip->flags | ip->sync_flags) & (HAMMER_INODE_RO|HAMMER_INODE_DELETING|HAMMER_INODE_DELETED)) == 0) {
3259 		ip->flags |= HAMMER_INODE_DELETING;
3260 		ip->flags |= HAMMER_INODE_TRUNCATED;
3261 		ip->trunc_off = 0;
3262 		vp = NULL;
3263 		if (getvp) {
3264 			if (hammer_get_vnode(ip, &vp) != 0)
3265 				return;
3266 		}
3267 
3268 		/*
3269 		 * Final cleanup
3270 		 */
3271 		if (ip->vp)
3272 			nvtruncbuf(ip->vp, 0, HAMMER_BUFSIZE, 0, 0);
3273 		if (ip->flags & HAMMER_INODE_MODMASK)
3274 			hammer_inode_dirty(ip);
3275 		if (getvp)
3276 			vput(vp);
3277 	}
3278 }
3279 
3280 /*
3281  * After potentially resolving a dependancy the inode is tested
3282  * to determine whether it needs to be reflushed.
3283  */
3284 void
3285 hammer_test_inode(hammer_inode_t ip)
3286 {
3287 	if (ip->flags & HAMMER_INODE_REFLUSH) {
3288 		ip->flags &= ~HAMMER_INODE_REFLUSH;
3289 		hammer_ref(&ip->lock);
3290 		if (ip->flags & HAMMER_INODE_RESIGNAL) {
3291 			ip->flags &= ~HAMMER_INODE_RESIGNAL;
3292 			hammer_flush_inode(ip, HAMMER_FLUSH_SIGNAL);
3293 		} else {
3294 			hammer_flush_inode(ip, 0);
3295 		}
3296 		hammer_rel_inode(ip, 0);
3297 	}
3298 }
3299 
3300 /*
3301  * Clear the RECLAIM flag on an inode.  This occurs when the inode is
3302  * reassociated with a vp or just before it gets freed.
3303  *
3304  * Pipeline wakeups to threads blocked due to an excessive number of
3305  * detached inodes.  This typically occurs when atime updates accumulate
3306  * while scanning a directory tree.
3307  */
3308 static void
3309 hammer_inode_wakereclaims(hammer_inode_t ip)
3310 {
3311 	struct hammer_reclaim *reclaim;
3312 	hammer_mount_t hmp = ip->hmp;
3313 
3314 	if ((ip->flags & HAMMER_INODE_RECLAIM) == 0)
3315 		return;
3316 
3317 	--hammer_count_reclaims;
3318 	--hmp->count_reclaims;
3319 	ip->flags &= ~HAMMER_INODE_RECLAIM;
3320 
3321 	if ((reclaim = TAILQ_FIRST(&hmp->reclaim_list)) != NULL) {
3322 		KKASSERT(reclaim->count > 0);
3323 		if (--reclaim->count == 0) {
3324 			TAILQ_REMOVE(&hmp->reclaim_list, reclaim, entry);
3325 			wakeup(reclaim);
3326 		}
3327 	}
3328 }
3329 
3330 /*
3331  * Setup our reclaim pipeline.  We only let so many detached (and dirty)
3332  * inodes build up before we start blocking.  This routine is called
3333  * if a new inode is created or an inode is loaded from media.
3334  *
3335  * When we block we don't care *which* inode has finished reclaiming,
3336  * as long as one does.
3337  *
3338  * The reclaim pipeline is primarily governed by the auto-flush which is
3339  * 1/4 hammer_limit_reclaims.  We don't want to block if the count is
3340  * less than 1/2 hammer_limit_reclaims.  From 1/2 to full count is
3341  * dynamically governed.
3342  */
3343 void
3344 hammer_inode_waitreclaims(hammer_transaction_t trans)
3345 {
3346 	hammer_mount_t hmp = trans->hmp;
3347 	struct hammer_reclaim reclaim;
3348 	int lower_limit;
3349 
3350 	/*
3351 	 * Track inode load, delay if the number of reclaiming inodes is
3352 	 * between 2/4 and 4/4 hammer_limit_reclaims, depending.
3353 	 */
3354 	if (curthread->td_proc) {
3355 		struct hammer_inostats *stats;
3356 
3357 		stats = hammer_inode_inostats(hmp, curthread->td_proc->p_pid);
3358 		++stats->count;
3359 
3360 		if (stats->count > hammer_limit_reclaims / 2)
3361 			stats->count = hammer_limit_reclaims / 2;
3362 		lower_limit = hammer_limit_reclaims - stats->count;
3363 		if (hammer_debug_general & 0x10000) {
3364 			hdkprintf("pid %5d limit %d\n",
3365 				(int)curthread->td_proc->p_pid, lower_limit);
3366 		}
3367 	} else {
3368 		lower_limit = hammer_limit_reclaims * 3 / 4;
3369 	}
3370 	if (hmp->count_reclaims >= lower_limit) {
3371 		reclaim.count = 1;
3372 		TAILQ_INSERT_TAIL(&hmp->reclaim_list, &reclaim, entry);
3373 		tsleep(&reclaim, 0, "hmrrcm", hz);
3374 		if (reclaim.count > 0)
3375 			TAILQ_REMOVE(&hmp->reclaim_list, &reclaim, entry);
3376 	}
3377 }
3378 
3379 /*
3380  * Keep track of reclaim statistics on a per-pid basis using a loose
3381  * 4-way set associative hash table.  Collisions inherit the count of
3382  * the previous entry.
3383  *
3384  * NOTE: We want to be careful here to limit the chain size.  If the chain
3385  *	 size is too large a pid will spread its stats out over too many
3386  *	 entries under certain types of heavy filesystem activity and
3387  *	 wind up not delaying long enough.
3388  */
3389 static
3390 struct hammer_inostats *
3391 hammer_inode_inostats(hammer_mount_t hmp, pid_t pid)
3392 {
3393 	struct hammer_inostats *stats;
3394 	int delta;
3395 	int chain;
3396 	static volatile int iterator;	/* we don't care about MP races */
3397 
3398 	/*
3399 	 * Chain up to 4 times to find our entry.
3400 	 */
3401 	for (chain = 0; chain < 4; ++chain) {
3402 		stats = &hmp->inostats[(pid + chain) & HAMMER_INOSTATS_HMASK];
3403 		if (stats->pid == pid)
3404 			break;
3405 	}
3406 
3407 	/*
3408 	 * Replace one of the four chaining entries with our new entry.
3409 	 */
3410 	if (chain == 4) {
3411 		stats = &hmp->inostats[(pid + (iterator++ & 3)) &
3412 				       HAMMER_INOSTATS_HMASK];
3413 		stats->pid = pid;
3414 	}
3415 
3416 	/*
3417 	 * Decay the entry
3418 	 */
3419 	if (stats->count && stats->ltick != ticks) {
3420 		delta = ticks - stats->ltick;
3421 		stats->ltick = ticks;
3422 		if (delta <= 0 || delta > hz * 60)
3423 			stats->count = 0;
3424 		else
3425 			stats->count = stats->count * hz / (hz + delta);
3426 	}
3427 	if (hammer_debug_general & 0x10000)
3428 		hdkprintf("pid %5d stats %d\n", (int)pid, stats->count);
3429 	return (stats);
3430 }
3431 
3432 #if 0
3433 
3434 /*
3435  * XXX not used, doesn't work very well due to the large batching nature
3436  * of flushes.
3437  *
3438  * A larger then normal backlog of inodes is sitting in the flusher,
3439  * enforce a general slowdown to let it catch up.  This routine is only
3440  * called on completion of a non-flusher-related transaction which
3441  * performed B-Tree node I/O.
3442  *
3443  * It is possible for the flusher to stall in a continuous load.
3444  * blogbench -i1000 -o seems to do a good job generating this sort of load.
3445  * If the flusher is unable to catch up the inode count can bloat until
3446  * we run out of kvm.
3447  *
3448  * This is a bit of a hack.
3449  */
3450 void
3451 hammer_inode_waithard(hammer_mount_t hmp)
3452 {
3453 	/*
3454 	 * Hysteresis.
3455 	 */
3456 	if (hmp->flags & HAMMER_MOUNT_FLUSH_RECOVERY) {
3457 		if (hmp->count_reclaims < hammer_limit_reclaims / 2 &&
3458 		    hmp->count_iqueued < hmp->count_inodes / 20) {
3459 			hmp->flags &= ~HAMMER_MOUNT_FLUSH_RECOVERY;
3460 			return;
3461 		}
3462 	} else {
3463 		if (hmp->count_reclaims < hammer_limit_reclaims ||
3464 		    hmp->count_iqueued < hmp->count_inodes / 10) {
3465 			return;
3466 		}
3467 		hmp->flags |= HAMMER_MOUNT_FLUSH_RECOVERY;
3468 	}
3469 
3470 	/*
3471 	 * Block for one flush cycle.
3472 	 */
3473 	hammer_flusher_wait_next(hmp);
3474 }
3475 
3476 #endif
3477