xref: /dragonfly/sys/vfs/hammer/hammer_inode.c (revision 10cbe914)
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  * $DragonFly: src/sys/vfs/hammer/hammer_inode.c,v 1.114 2008/09/24 00:53:51 dillon Exp $
35  */
36 
37 #include "hammer.h"
38 #include <vm/vm_extern.h>
39 
40 static int	hammer_unload_inode(struct hammer_inode *ip);
41 static void	hammer_free_inode(hammer_inode_t ip);
42 static void	hammer_flush_inode_core(hammer_inode_t ip,
43 					hammer_flush_group_t flg, int flags);
44 static int	hammer_setup_child_callback(hammer_record_t rec, void *data);
45 #if 0
46 static int	hammer_syncgrp_child_callback(hammer_record_t rec, void *data);
47 #endif
48 static int	hammer_setup_parent_inodes(hammer_inode_t ip, int depth,
49 					hammer_flush_group_t flg);
50 static int	hammer_setup_parent_inodes_helper(hammer_record_t record,
51 					int depth, hammer_flush_group_t flg);
52 static void	hammer_inode_wakereclaims(hammer_inode_t ip);
53 static struct hammer_inostats *hammer_inode_inostats(hammer_mount_t hmp,
54 					pid_t pid);
55 
56 #ifdef DEBUG_TRUNCATE
57 extern struct hammer_inode *HammerTruncIp;
58 #endif
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 	u_int32_t localization = *(u_int32_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, u_int32_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_reclaiming;
241 			++hmp->inode_reclaims;
242 			ip->flags |= HAMMER_INODE_RECLAIM;
243 		}
244 		hammer_unlock(&ip->lock);
245 		hammer_rel_inode(ip, 1);
246 		lwkt_reltoken(&hmp->fs_token);
247 	}
248 	return(0);
249 }
250 
251 /*
252  * Return a locked vnode for the specified inode.  The inode must be
253  * referenced but NOT LOCKED on entry and will remain referenced on
254  * return.
255  *
256  * Called from the frontend.
257  */
258 int
259 hammer_get_vnode(struct hammer_inode *ip, struct vnode **vpp)
260 {
261 	hammer_mount_t hmp;
262 	struct vnode *vp;
263 	int error = 0;
264 	u_int8_t obj_type;
265 
266 	hmp = ip->hmp;
267 
268 	for (;;) {
269 		if ((vp = ip->vp) == NULL) {
270 			error = getnewvnode(VT_HAMMER, hmp->mp, vpp, 0, 0);
271 			if (error)
272 				break;
273 			hammer_lock_ex(&ip->lock);
274 			if (ip->vp != NULL) {
275 				hammer_unlock(&ip->lock);
276 				vp = *vpp;
277 				vp->v_type = VBAD;
278 				vx_put(vp);
279 				continue;
280 			}
281 			hammer_ref(&ip->lock);
282 			vp = *vpp;
283 			ip->vp = vp;
284 
285 			obj_type = ip->ino_data.obj_type;
286 			vp->v_type = hammer_get_vnode_type(obj_type);
287 
288 			hammer_inode_wakereclaims(ip);
289 
290 			switch(ip->ino_data.obj_type) {
291 			case HAMMER_OBJTYPE_CDEV:
292 			case HAMMER_OBJTYPE_BDEV:
293 				vp->v_ops = &hmp->mp->mnt_vn_spec_ops;
294 				addaliasu(vp, ip->ino_data.rmajor,
295 					  ip->ino_data.rminor);
296 				break;
297 			case HAMMER_OBJTYPE_FIFO:
298 				vp->v_ops = &hmp->mp->mnt_vn_fifo_ops;
299 				break;
300 			case HAMMER_OBJTYPE_REGFILE:
301 				break;
302 			default:
303 				break;
304 			}
305 
306 			/*
307 			 * Only mark as the root vnode if the ip is not
308 			 * historical, otherwise the VFS cache will get
309 			 * confused.  The other half of the special handling
310 			 * is in hammer_vop_nlookupdotdot().
311 			 *
312 			 * Pseudo-filesystem roots can be accessed via
313 			 * non-root filesystem paths and setting VROOT may
314 			 * confuse the namecache.  Set VPFSROOT instead.
315 			 */
316 			if (ip->obj_id == HAMMER_OBJID_ROOT &&
317 			    ip->obj_asof == hmp->asof) {
318 				if (ip->obj_localization == 0)
319 					vsetflags(vp, VROOT);
320 				else
321 					vsetflags(vp, VPFSROOT);
322 			}
323 
324 			vp->v_data = (void *)ip;
325 			/* vnode locked by getnewvnode() */
326 			/* make related vnode dirty if inode dirty? */
327 			hammer_unlock(&ip->lock);
328 			if (vp->v_type == VREG) {
329 				vinitvmio(vp, ip->ino_data.size,
330 					  hammer_blocksize(ip->ino_data.size),
331 					  hammer_blockoff(ip->ino_data.size));
332 			}
333 			break;
334 		}
335 
336 		/*
337 		 * Interlock vnode clearing.  This does not prevent the
338 		 * vnode from going into a reclaimed state but it does
339 		 * prevent it from being destroyed or reused so the vget()
340 		 * will properly fail.
341 		 */
342 		hammer_lock_ex(&ip->lock);
343 		if ((vp = ip->vp) == NULL) {
344 			hammer_unlock(&ip->lock);
345 			continue;
346 		}
347 		vhold_interlocked(vp);
348 		hammer_unlock(&ip->lock);
349 
350 		/*
351 		 * loop if the vget fails (aka races), or if the vp
352 		 * no longer matches ip->vp.
353 		 */
354 		if (vget(vp, LK_EXCLUSIVE) == 0) {
355 			if (vp == ip->vp) {
356 				vdrop(vp);
357 				break;
358 			}
359 			vput(vp);
360 		}
361 		vdrop(vp);
362 	}
363 	*vpp = vp;
364 	return(error);
365 }
366 
367 /*
368  * Locate all copies of the inode for obj_id compatible with the specified
369  * asof, reference, and issue the related call-back.  This routine is used
370  * for direct-io invalidation and does not create any new inodes.
371  */
372 void
373 hammer_scan_inode_snapshots(hammer_mount_t hmp, hammer_inode_info_t iinfo,
374 		            int (*callback)(hammer_inode_t ip, void *data),
375 			    void *data)
376 {
377 	hammer_ino_rb_tree_RB_SCAN(&hmp->rb_inos_root,
378 				   hammer_inode_info_cmp_all_history,
379 				   callback, iinfo);
380 }
381 
382 /*
383  * Acquire a HAMMER inode.  The returned inode is not locked.  These functions
384  * do not attach or detach the related vnode (use hammer_get_vnode() for
385  * that).
386  *
387  * The flags argument is only applied for newly created inodes, and only
388  * certain flags are inherited.
389  *
390  * Called from the frontend.
391  */
392 struct hammer_inode *
393 hammer_get_inode(hammer_transaction_t trans, hammer_inode_t dip,
394 		 int64_t obj_id, hammer_tid_t asof, u_int32_t localization,
395 		 int flags, int *errorp)
396 {
397 	hammer_mount_t hmp = trans->hmp;
398 	struct hammer_node_cache *cachep;
399 	struct hammer_inode_info iinfo;
400 	struct hammer_cursor cursor;
401 	struct hammer_inode *ip;
402 
403 
404 	/*
405 	 * Determine if we already have an inode cached.  If we do then
406 	 * we are golden.
407 	 *
408 	 * If we find an inode with no vnode we have to mark the
409 	 * transaction such that hammer_inode_waitreclaims() is
410 	 * called later on to avoid building up an infinite number
411 	 * of inodes.  Otherwise we can continue to * add new inodes
412 	 * faster then they can be disposed of, even with the tsleep
413 	 * delay.
414 	 *
415 	 * If we find a dummy inode we return a failure so dounlink
416 	 * (which does another lookup) doesn't try to mess with the
417 	 * link count.  hammer_vop_nresolve() uses hammer_get_dummy_inode()
418 	 * to ref dummy inodes.
419 	 */
420 	iinfo.obj_id = obj_id;
421 	iinfo.obj_asof = asof;
422 	iinfo.obj_localization = localization;
423 loop:
424 	ip = hammer_ino_rb_tree_RB_LOOKUP_INFO(&hmp->rb_inos_root, &iinfo);
425 	if (ip) {
426 		if (ip->flags & HAMMER_INODE_DUMMY) {
427 			*errorp = ENOENT;
428 			return(NULL);
429 		}
430 		hammer_ref(&ip->lock);
431 		*errorp = 0;
432 		return(ip);
433 	}
434 
435 	/*
436 	 * Allocate a new inode structure and deal with races later.
437 	 */
438 	ip = kmalloc(sizeof(*ip), hmp->m_inodes, M_WAITOK|M_ZERO);
439 	++hammer_count_inodes;
440 	++hmp->count_inodes;
441 	ip->obj_id = obj_id;
442 	ip->obj_asof = iinfo.obj_asof;
443 	ip->obj_localization = localization;
444 	ip->hmp = hmp;
445 	ip->flags = flags & HAMMER_INODE_RO;
446 	ip->cache[0].ip = ip;
447 	ip->cache[1].ip = ip;
448 	ip->cache[2].ip = ip;
449 	ip->cache[3].ip = ip;
450 	if (hmp->ronly)
451 		ip->flags |= HAMMER_INODE_RO;
452 	ip->sync_trunc_off = ip->trunc_off = ip->save_trunc_off =
453 		0x7FFFFFFFFFFFFFFFLL;
454 	RB_INIT(&ip->rec_tree);
455 	TAILQ_INIT(&ip->target_list);
456 	hammer_ref(&ip->lock);
457 
458 	/*
459 	 * Locate the on-disk inode.  If this is a PFS root we always
460 	 * access the current version of the root inode and (if it is not
461 	 * a master) always access information under it with a snapshot
462 	 * TID.
463 	 *
464 	 * We cache recent inode lookups in this directory in dip->cache[2].
465 	 * If we can't find it we assume the inode we are looking for is
466 	 * close to the directory inode.
467 	 */
468 retry:
469 	cachep = NULL;
470 	if (dip) {
471 		if (dip->cache[2].node)
472 			cachep = &dip->cache[2];
473 		else
474 			cachep = &dip->cache[0];
475 	}
476 	hammer_init_cursor(trans, &cursor, cachep, NULL);
477 	cursor.key_beg.localization = localization + HAMMER_LOCALIZE_INODE;
478 	cursor.key_beg.obj_id = ip->obj_id;
479 	cursor.key_beg.key = 0;
480 	cursor.key_beg.create_tid = 0;
481 	cursor.key_beg.delete_tid = 0;
482 	cursor.key_beg.rec_type = HAMMER_RECTYPE_INODE;
483 	cursor.key_beg.obj_type = 0;
484 
485 	cursor.asof = iinfo.obj_asof;
486 	cursor.flags = HAMMER_CURSOR_GET_LEAF | HAMMER_CURSOR_GET_DATA |
487 		       HAMMER_CURSOR_ASOF;
488 
489 	*errorp = hammer_btree_lookup(&cursor);
490 	if (*errorp == EDEADLK) {
491 		hammer_done_cursor(&cursor);
492 		goto retry;
493 	}
494 
495 	/*
496 	 * On success the B-Tree lookup will hold the appropriate
497 	 * buffer cache buffers and provide a pointer to the requested
498 	 * information.  Copy the information to the in-memory inode
499 	 * and cache the B-Tree node to improve future operations.
500 	 */
501 	if (*errorp == 0) {
502 		ip->ino_leaf = cursor.node->ondisk->elms[cursor.index].leaf;
503 		ip->ino_data = cursor.data->inode;
504 
505 		/*
506 		 * cache[0] tries to cache the location of the object inode.
507 		 * The assumption is that it is near the directory inode.
508 		 *
509 		 * cache[1] tries to cache the location of the object data.
510 		 * We might have something in the governing directory from
511 		 * scan optimizations (see the strategy code in
512 		 * hammer_vnops.c).
513 		 *
514 		 * We update dip->cache[2], if possible, with the location
515 		 * of the object inode for future directory shortcuts.
516 		 */
517 		hammer_cache_node(&ip->cache[0], cursor.node);
518 		if (dip) {
519 			if (dip->cache[3].node) {
520 				hammer_cache_node(&ip->cache[1],
521 						  dip->cache[3].node);
522 			}
523 			hammer_cache_node(&dip->cache[2], cursor.node);
524 		}
525 
526 		/*
527 		 * The file should not contain any data past the file size
528 		 * stored in the inode.  Setting save_trunc_off to the
529 		 * file size instead of max reduces B-Tree lookup overheads
530 		 * on append by allowing the flusher to avoid checking for
531 		 * record overwrites.
532 		 */
533 		ip->save_trunc_off = ip->ino_data.size;
534 
535 		/*
536 		 * Locate and assign the pseudofs management structure to
537 		 * the inode.
538 		 */
539 		if (dip && dip->obj_localization == ip->obj_localization) {
540 			ip->pfsm = dip->pfsm;
541 			hammer_ref(&ip->pfsm->lock);
542 		} else {
543 			ip->pfsm = hammer_load_pseudofs(trans,
544 							ip->obj_localization,
545 							errorp);
546 			*errorp = 0;	/* ignore ENOENT */
547 		}
548 	}
549 
550 	/*
551 	 * The inode is placed on the red-black tree and will be synced to
552 	 * the media when flushed or by the filesystem sync.  If this races
553 	 * another instantiation/lookup the insertion will fail.
554 	 */
555 	if (*errorp == 0) {
556 		if (RB_INSERT(hammer_ino_rb_tree, &hmp->rb_inos_root, ip)) {
557 			hammer_free_inode(ip);
558 			hammer_done_cursor(&cursor);
559 			goto loop;
560 		}
561 		ip->flags |= HAMMER_INODE_ONDISK;
562 	} else {
563 		if (ip->flags & HAMMER_INODE_RSV_INODES) {
564 			ip->flags &= ~HAMMER_INODE_RSV_INODES; /* sanity */
565 			--hmp->rsv_inodes;
566 		}
567 
568 		hammer_free_inode(ip);
569 		ip = NULL;
570 	}
571 	hammer_done_cursor(&cursor);
572 
573 	/*
574 	 * NEWINODE is only set if the inode becomes dirty later,
575 	 * setting it here just leads to unnecessary stalls.
576 	 *
577 	 * trans->flags |= HAMMER_TRANSF_NEWINODE;
578 	 */
579 	return (ip);
580 }
581 
582 /*
583  * Get a dummy inode to placemark a broken directory entry.
584  */
585 struct hammer_inode *
586 hammer_get_dummy_inode(hammer_transaction_t trans, hammer_inode_t dip,
587 		 int64_t obj_id, hammer_tid_t asof, u_int32_t localization,
588 		 int flags, int *errorp)
589 {
590 	hammer_mount_t hmp = trans->hmp;
591 	struct hammer_inode_info iinfo;
592 	struct hammer_inode *ip;
593 
594 	/*
595 	 * Determine if we already have an inode cached.  If we do then
596 	 * we are golden.
597 	 *
598 	 * If we find an inode with no vnode we have to mark the
599 	 * transaction such that hammer_inode_waitreclaims() is
600 	 * called later on to avoid building up an infinite number
601 	 * of inodes.  Otherwise we can continue to * add new inodes
602 	 * faster then they can be disposed of, even with the tsleep
603 	 * delay.
604 	 *
605 	 * If we find a non-fake inode we return an error.  Only fake
606 	 * inodes can be returned by this routine.
607 	 */
608 	iinfo.obj_id = obj_id;
609 	iinfo.obj_asof = asof;
610 	iinfo.obj_localization = localization;
611 loop:
612 	*errorp = 0;
613 	ip = hammer_ino_rb_tree_RB_LOOKUP_INFO(&hmp->rb_inos_root, &iinfo);
614 	if (ip) {
615 		if ((ip->flags & HAMMER_INODE_DUMMY) == 0) {
616 			*errorp = ENOENT;
617 			return(NULL);
618 		}
619 		hammer_ref(&ip->lock);
620 		return(ip);
621 	}
622 
623 	/*
624 	 * Allocate a new inode structure and deal with races later.
625 	 */
626 	ip = kmalloc(sizeof(*ip), hmp->m_inodes, M_WAITOK|M_ZERO);
627 	++hammer_count_inodes;
628 	++hmp->count_inodes;
629 	ip->obj_id = obj_id;
630 	ip->obj_asof = iinfo.obj_asof;
631 	ip->obj_localization = localization;
632 	ip->hmp = hmp;
633 	ip->flags = flags | HAMMER_INODE_RO | HAMMER_INODE_DUMMY;
634 	ip->cache[0].ip = ip;
635 	ip->cache[1].ip = ip;
636 	ip->cache[2].ip = ip;
637 	ip->cache[3].ip = ip;
638 	ip->sync_trunc_off = ip->trunc_off = ip->save_trunc_off =
639 		0x7FFFFFFFFFFFFFFFLL;
640 	RB_INIT(&ip->rec_tree);
641 	TAILQ_INIT(&ip->target_list);
642 	hammer_ref(&ip->lock);
643 
644 	/*
645 	 * Populate the dummy inode.  Leave everything zero'd out.
646 	 *
647 	 * (ip->ino_leaf and ip->ino_data)
648 	 *
649 	 * Make the dummy inode a FIFO object which most copy programs
650 	 * will properly ignore.
651 	 */
652 	ip->save_trunc_off = ip->ino_data.size;
653 	ip->ino_data.obj_type = HAMMER_OBJTYPE_FIFO;
654 
655 	/*
656 	 * Locate and assign the pseudofs management structure to
657 	 * the inode.
658 	 */
659 	if (dip && dip->obj_localization == ip->obj_localization) {
660 		ip->pfsm = dip->pfsm;
661 		hammer_ref(&ip->pfsm->lock);
662 	} else {
663 		ip->pfsm = hammer_load_pseudofs(trans, ip->obj_localization,
664 						errorp);
665 		*errorp = 0;	/* ignore ENOENT */
666 	}
667 
668 	/*
669 	 * The inode is placed on the red-black tree and will be synced to
670 	 * the media when flushed or by the filesystem sync.  If this races
671 	 * another instantiation/lookup the insertion will fail.
672 	 *
673 	 * NOTE: Do not set HAMMER_INODE_ONDISK.  The inode is a fake.
674 	 */
675 	if (*errorp == 0) {
676 		if (RB_INSERT(hammer_ino_rb_tree, &hmp->rb_inos_root, ip)) {
677 			hammer_free_inode(ip);
678 			goto loop;
679 		}
680 	} else {
681 		if (ip->flags & HAMMER_INODE_RSV_INODES) {
682 			ip->flags &= ~HAMMER_INODE_RSV_INODES; /* sanity */
683 			--hmp->rsv_inodes;
684 		}
685 		hammer_free_inode(ip);
686 		ip = NULL;
687 	}
688 	trans->flags |= HAMMER_TRANSF_NEWINODE;
689 	return (ip);
690 }
691 
692 /*
693  * Return a referenced inode only if it is in our inode cache.
694  *
695  * Dummy inodes do not count.
696  */
697 struct hammer_inode *
698 hammer_find_inode(hammer_transaction_t trans, int64_t obj_id,
699 		  hammer_tid_t asof, u_int32_t localization)
700 {
701 	hammer_mount_t hmp = trans->hmp;
702 	struct hammer_inode_info iinfo;
703 	struct hammer_inode *ip;
704 
705 	iinfo.obj_id = obj_id;
706 	iinfo.obj_asof = asof;
707 	iinfo.obj_localization = localization;
708 
709 	ip = hammer_ino_rb_tree_RB_LOOKUP_INFO(&hmp->rb_inos_root, &iinfo);
710 	if (ip) {
711 		if (ip->flags & HAMMER_INODE_DUMMY)
712 			ip = NULL;
713 		else
714 			hammer_ref(&ip->lock);
715 	}
716 	return(ip);
717 }
718 
719 /*
720  * Create a new filesystem object, returning the inode in *ipp.  The
721  * returned inode will be referenced.  The inode is created in-memory.
722  *
723  * If pfsm is non-NULL the caller wishes to create the root inode for
724  * a master PFS.
725  */
726 int
727 hammer_create_inode(hammer_transaction_t trans, struct vattr *vap,
728 		    struct ucred *cred,
729 		    hammer_inode_t dip, const char *name, int namelen,
730 		    hammer_pseudofs_inmem_t pfsm, struct hammer_inode **ipp)
731 {
732 	hammer_mount_t hmp;
733 	hammer_inode_t ip;
734 	uid_t xuid;
735 	int error;
736 	int64_t namekey;
737 	u_int32_t dummy;
738 
739 	hmp = trans->hmp;
740 
741 	ip = kmalloc(sizeof(*ip), hmp->m_inodes, M_WAITOK|M_ZERO);
742 	++hammer_count_inodes;
743 	++hmp->count_inodes;
744 	trans->flags |= HAMMER_TRANSF_NEWINODE;
745 
746 	if (pfsm) {
747 		KKASSERT(pfsm->localization != 0);
748 		ip->obj_id = HAMMER_OBJID_ROOT;
749 		ip->obj_localization = pfsm->localization;
750 	} else {
751 		KKASSERT(dip != NULL);
752 		namekey = hammer_directory_namekey(dip, name, namelen, &dummy);
753 		ip->obj_id = hammer_alloc_objid(hmp, dip, namekey);
754 		ip->obj_localization = dip->obj_localization;
755 	}
756 
757 	KKASSERT(ip->obj_id != 0);
758 	ip->obj_asof = hmp->asof;
759 	ip->hmp = hmp;
760 	ip->flush_state = HAMMER_FST_IDLE;
761 	ip->flags = HAMMER_INODE_DDIRTY |
762 		    HAMMER_INODE_ATIME | HAMMER_INODE_MTIME;
763 	ip->cache[0].ip = ip;
764 	ip->cache[1].ip = ip;
765 	ip->cache[2].ip = ip;
766 	ip->cache[3].ip = ip;
767 
768 	ip->trunc_off = 0x7FFFFFFFFFFFFFFFLL;
769 	/* ip->save_trunc_off = 0; (already zero) */
770 	RB_INIT(&ip->rec_tree);
771 	TAILQ_INIT(&ip->target_list);
772 
773 	ip->ino_data.atime = trans->time;
774 	ip->ino_data.mtime = trans->time;
775 	ip->ino_data.size = 0;
776 	ip->ino_data.nlinks = 0;
777 
778 	/*
779 	 * A nohistory designator on the parent directory is inherited by
780 	 * the child.  We will do this even for pseudo-fs creation... the
781 	 * sysad can turn it off.
782 	 */
783 	if (dip) {
784 		ip->ino_data.uflags = dip->ino_data.uflags &
785 				      (SF_NOHISTORY|UF_NOHISTORY|UF_NODUMP);
786 	}
787 
788 	ip->ino_leaf.base.btype = HAMMER_BTREE_TYPE_RECORD;
789 	ip->ino_leaf.base.localization = ip->obj_localization +
790 					 HAMMER_LOCALIZE_INODE;
791 	ip->ino_leaf.base.obj_id = ip->obj_id;
792 	ip->ino_leaf.base.key = 0;
793 	ip->ino_leaf.base.create_tid = 0;
794 	ip->ino_leaf.base.delete_tid = 0;
795 	ip->ino_leaf.base.rec_type = HAMMER_RECTYPE_INODE;
796 	ip->ino_leaf.base.obj_type = hammer_get_obj_type(vap->va_type);
797 
798 	ip->ino_data.obj_type = ip->ino_leaf.base.obj_type;
799 	ip->ino_data.version = HAMMER_INODE_DATA_VERSION;
800 	ip->ino_data.mode = vap->va_mode;
801 	ip->ino_data.ctime = trans->time;
802 
803 	/*
804 	 * If we are running version 2 or greater directory entries are
805 	 * inode-localized instead of data-localized.
806 	 */
807 	if (trans->hmp->version >= HAMMER_VOL_VERSION_TWO) {
808 		if (ip->ino_leaf.base.obj_type == HAMMER_OBJTYPE_DIRECTORY) {
809 			ip->ino_data.cap_flags |=
810 				HAMMER_INODE_CAP_DIR_LOCAL_INO;
811 		}
812 	}
813 
814 	/*
815 	 * Setup the ".." pointer.  This only needs to be done for directories
816 	 * but we do it for all objects as a recovery aid.
817 	 */
818 	if (dip)
819 		ip->ino_data.parent_obj_id = dip->ino_leaf.base.obj_id;
820 #if 0
821 	/*
822 	 * The parent_obj_localization field only applies to pseudo-fs roots.
823 	 * XXX this is no longer applicable, PFSs are no longer directly
824 	 * tied into the parent's directory structure.
825 	 */
826 	if (ip->ino_data.obj_type == HAMMER_OBJTYPE_DIRECTORY &&
827 	    ip->obj_id == HAMMER_OBJID_ROOT) {
828 		ip->ino_data.ext.obj.parent_obj_localization =
829 						dip->obj_localization;
830 	}
831 #endif
832 
833 	switch(ip->ino_leaf.base.obj_type) {
834 	case HAMMER_OBJTYPE_CDEV:
835 	case HAMMER_OBJTYPE_BDEV:
836 		ip->ino_data.rmajor = vap->va_rmajor;
837 		ip->ino_data.rminor = vap->va_rminor;
838 		break;
839 	default:
840 		break;
841 	}
842 
843 	/*
844 	 * Calculate default uid/gid and overwrite with information from
845 	 * the vap.
846 	 */
847 	if (dip) {
848 		xuid = hammer_to_unix_xid(&dip->ino_data.uid);
849 		xuid = vop_helper_create_uid(hmp->mp, dip->ino_data.mode,
850 					     xuid, cred, &vap->va_mode);
851 	} else {
852 		xuid = 0;
853 	}
854 	ip->ino_data.mode = vap->va_mode;
855 
856 	if (vap->va_vaflags & VA_UID_UUID_VALID)
857 		ip->ino_data.uid = vap->va_uid_uuid;
858 	else if (vap->va_uid != (uid_t)VNOVAL)
859 		hammer_guid_to_uuid(&ip->ino_data.uid, vap->va_uid);
860 	else
861 		hammer_guid_to_uuid(&ip->ino_data.uid, xuid);
862 
863 	if (vap->va_vaflags & VA_GID_UUID_VALID)
864 		ip->ino_data.gid = vap->va_gid_uuid;
865 	else if (vap->va_gid != (gid_t)VNOVAL)
866 		hammer_guid_to_uuid(&ip->ino_data.gid, vap->va_gid);
867 	else if (dip)
868 		ip->ino_data.gid = dip->ino_data.gid;
869 
870 	hammer_ref(&ip->lock);
871 
872 	if (pfsm) {
873 		ip->pfsm = pfsm;
874 		hammer_ref(&pfsm->lock);
875 		error = 0;
876 	} else if (dip->obj_localization == ip->obj_localization) {
877 		ip->pfsm = dip->pfsm;
878 		hammer_ref(&ip->pfsm->lock);
879 		error = 0;
880 	} else {
881 		ip->pfsm = hammer_load_pseudofs(trans,
882 						ip->obj_localization,
883 						&error);
884 		error = 0;	/* ignore ENOENT */
885 	}
886 
887 	if (error) {
888 		hammer_free_inode(ip);
889 		ip = NULL;
890 	} else if (RB_INSERT(hammer_ino_rb_tree, &hmp->rb_inos_root, ip)) {
891 		panic("hammer_create_inode: duplicate obj_id %llx",
892 		      (long long)ip->obj_id);
893 		/* not reached */
894 		hammer_free_inode(ip);
895 	}
896 	*ipp = ip;
897 	return(error);
898 }
899 
900 /*
901  * Final cleanup / freeing of an inode structure
902  */
903 static void
904 hammer_free_inode(hammer_inode_t ip)
905 {
906 	struct hammer_mount *hmp;
907 
908 	hmp = ip->hmp;
909 	KKASSERT(hammer_oneref(&ip->lock));
910 	hammer_uncache_node(&ip->cache[0]);
911 	hammer_uncache_node(&ip->cache[1]);
912 	hammer_uncache_node(&ip->cache[2]);
913 	hammer_uncache_node(&ip->cache[3]);
914 	hammer_inode_wakereclaims(ip);
915 	if (ip->objid_cache)
916 		hammer_clear_objid(ip);
917 	--hammer_count_inodes;
918 	--hmp->count_inodes;
919 	if (ip->pfsm) {
920 		hammer_rel_pseudofs(hmp, ip->pfsm);
921 		ip->pfsm = NULL;
922 	}
923 	kfree(ip, hmp->m_inodes);
924 	ip = NULL;
925 }
926 
927 /*
928  * Retrieve pseudo-fs data.  NULL will never be returned.
929  *
930  * If an error occurs *errorp will be set and a default template is returned,
931  * otherwise *errorp is set to 0.  Typically when an error occurs it will
932  * be ENOENT.
933  */
934 hammer_pseudofs_inmem_t
935 hammer_load_pseudofs(hammer_transaction_t trans,
936 		     u_int32_t localization, int *errorp)
937 {
938 	hammer_mount_t hmp = trans->hmp;
939 	hammer_inode_t ip;
940 	hammer_pseudofs_inmem_t pfsm;
941 	struct hammer_cursor cursor;
942 	int bytes;
943 
944 retry:
945 	pfsm = RB_LOOKUP(hammer_pfs_rb_tree, &hmp->rb_pfsm_root, localization);
946 	if (pfsm) {
947 		hammer_ref(&pfsm->lock);
948 		*errorp = 0;
949 		return(pfsm);
950 	}
951 
952 	/*
953 	 * PFS records are stored in the root inode (not the PFS root inode,
954 	 * but the real root).  Avoid an infinite recursion if loading
955 	 * the PFS for the real root.
956 	 */
957 	if (localization) {
958 		ip = hammer_get_inode(trans, NULL, HAMMER_OBJID_ROOT,
959 				      HAMMER_MAX_TID,
960 				      HAMMER_DEF_LOCALIZATION, 0, errorp);
961 	} else {
962 		ip = NULL;
963 	}
964 
965 	pfsm = kmalloc(sizeof(*pfsm), hmp->m_misc, M_WAITOK | M_ZERO);
966 	pfsm->localization = localization;
967 	pfsm->pfsd.unique_uuid = trans->rootvol->ondisk->vol_fsid;
968 	pfsm->pfsd.shared_uuid = pfsm->pfsd.unique_uuid;
969 
970 	hammer_init_cursor(trans, &cursor, (ip ? &ip->cache[1] : NULL), ip);
971 	cursor.key_beg.localization = HAMMER_DEF_LOCALIZATION +
972 				      HAMMER_LOCALIZE_MISC;
973 	cursor.key_beg.obj_id = HAMMER_OBJID_ROOT;
974 	cursor.key_beg.create_tid = 0;
975 	cursor.key_beg.delete_tid = 0;
976 	cursor.key_beg.rec_type = HAMMER_RECTYPE_PFS;
977 	cursor.key_beg.obj_type = 0;
978 	cursor.key_beg.key = localization;
979 	cursor.asof = HAMMER_MAX_TID;
980 	cursor.flags |= HAMMER_CURSOR_ASOF;
981 
982 	if (ip)
983 		*errorp = hammer_ip_lookup(&cursor);
984 	else
985 		*errorp = hammer_btree_lookup(&cursor);
986 	if (*errorp == 0) {
987 		*errorp = hammer_ip_resolve_data(&cursor);
988 		if (*errorp == 0) {
989 			if (cursor.data->pfsd.mirror_flags &
990 			    HAMMER_PFSD_DELETED) {
991 				*errorp = ENOENT;
992 			} else {
993 				bytes = cursor.leaf->data_len;
994 				if (bytes > sizeof(pfsm->pfsd))
995 					bytes = sizeof(pfsm->pfsd);
996 				bcopy(cursor.data, &pfsm->pfsd, bytes);
997 			}
998 		}
999 	}
1000 	hammer_done_cursor(&cursor);
1001 
1002 	pfsm->fsid_udev = hammer_fsid_to_udev(&pfsm->pfsd.shared_uuid);
1003 	hammer_ref(&pfsm->lock);
1004 	if (ip)
1005 		hammer_rel_inode(ip, 0);
1006 	if (RB_INSERT(hammer_pfs_rb_tree, &hmp->rb_pfsm_root, pfsm)) {
1007 		kfree(pfsm, hmp->m_misc);
1008 		goto retry;
1009 	}
1010 	return(pfsm);
1011 }
1012 
1013 /*
1014  * Store pseudo-fs data.  The backend will automatically delete any prior
1015  * on-disk pseudo-fs data but we have to delete in-memory versions.
1016  */
1017 int
1018 hammer_save_pseudofs(hammer_transaction_t trans, hammer_pseudofs_inmem_t pfsm)
1019 {
1020 	struct hammer_cursor cursor;
1021 	hammer_record_t record;
1022 	hammer_inode_t ip;
1023 	int error;
1024 
1025 	ip = hammer_get_inode(trans, NULL, HAMMER_OBJID_ROOT, HAMMER_MAX_TID,
1026 			      HAMMER_DEF_LOCALIZATION, 0, &error);
1027 retry:
1028 	pfsm->fsid_udev = hammer_fsid_to_udev(&pfsm->pfsd.shared_uuid);
1029 	hammer_init_cursor(trans, &cursor, &ip->cache[1], ip);
1030 	cursor.key_beg.localization = ip->obj_localization +
1031 				      HAMMER_LOCALIZE_MISC;
1032 	cursor.key_beg.obj_id = HAMMER_OBJID_ROOT;
1033 	cursor.key_beg.create_tid = 0;
1034 	cursor.key_beg.delete_tid = 0;
1035 	cursor.key_beg.rec_type = HAMMER_RECTYPE_PFS;
1036 	cursor.key_beg.obj_type = 0;
1037 	cursor.key_beg.key = pfsm->localization;
1038 	cursor.asof = HAMMER_MAX_TID;
1039 	cursor.flags |= HAMMER_CURSOR_ASOF;
1040 
1041 	/*
1042 	 * Replace any in-memory version of the record.
1043 	 */
1044 	error = hammer_ip_lookup(&cursor);
1045 	if (error == 0 && hammer_cursor_inmem(&cursor)) {
1046 		record = cursor.iprec;
1047 		if (record->flags & HAMMER_RECF_INTERLOCK_BE) {
1048 			KKASSERT(cursor.deadlk_rec == NULL);
1049 			hammer_ref(&record->lock);
1050 			cursor.deadlk_rec = record;
1051 			error = EDEADLK;
1052 		} else {
1053 			record->flags |= HAMMER_RECF_DELETED_FE;
1054 			error = 0;
1055 		}
1056 	}
1057 
1058 	/*
1059 	 * Allocate replacement general record.  The backend flush will
1060 	 * delete any on-disk version of the record.
1061 	 */
1062 	if (error == 0 || error == ENOENT) {
1063 		record = hammer_alloc_mem_record(ip, sizeof(pfsm->pfsd));
1064 		record->type = HAMMER_MEM_RECORD_GENERAL;
1065 
1066 		record->leaf.base.localization = ip->obj_localization +
1067 						 HAMMER_LOCALIZE_MISC;
1068 		record->leaf.base.rec_type = HAMMER_RECTYPE_PFS;
1069 		record->leaf.base.key = pfsm->localization;
1070 		record->leaf.data_len = sizeof(pfsm->pfsd);
1071 		bcopy(&pfsm->pfsd, record->data, sizeof(pfsm->pfsd));
1072 		error = hammer_ip_add_record(trans, record);
1073 	}
1074 	hammer_done_cursor(&cursor);
1075 	if (error == EDEADLK)
1076 		goto retry;
1077 	hammer_rel_inode(ip, 0);
1078 	return(error);
1079 }
1080 
1081 /*
1082  * Create a root directory for a PFS if one does not alredy exist.
1083  *
1084  * The PFS root stands alone so we must also bump the nlinks count
1085  * to prevent it from being destroyed on release.
1086  */
1087 int
1088 hammer_mkroot_pseudofs(hammer_transaction_t trans, struct ucred *cred,
1089 		       hammer_pseudofs_inmem_t pfsm)
1090 {
1091 	hammer_inode_t ip;
1092 	struct vattr vap;
1093 	int error;
1094 
1095 	ip = hammer_get_inode(trans, NULL, HAMMER_OBJID_ROOT, HAMMER_MAX_TID,
1096 			      pfsm->localization, 0, &error);
1097 	if (ip == NULL) {
1098 		vattr_null(&vap);
1099 		vap.va_mode = 0755;
1100 		vap.va_type = VDIR;
1101 		error = hammer_create_inode(trans, &vap, cred,
1102 					    NULL, NULL, 0,
1103 					    pfsm, &ip);
1104 		if (error == 0) {
1105 			++ip->ino_data.nlinks;
1106 			hammer_modify_inode(trans, ip, HAMMER_INODE_DDIRTY);
1107 		}
1108 	}
1109 	if (ip)
1110 		hammer_rel_inode(ip, 0);
1111 	return(error);
1112 }
1113 
1114 /*
1115  * Unload any vnodes & inodes associated with a PFS, return ENOTEMPTY
1116  * if we are unable to disassociate all the inodes.
1117  */
1118 static
1119 int
1120 hammer_unload_pseudofs_callback(hammer_inode_t ip, void *data)
1121 {
1122 	int res;
1123 
1124 	hammer_ref(&ip->lock);
1125 	if (hammer_isactive(&ip->lock) == 2 && ip->vp)
1126 		vclean_unlocked(ip->vp);
1127 	if (hammer_isactive(&ip->lock) == 1 && ip->vp == NULL)
1128 		res = 0;
1129 	else
1130 		res = -1;	/* stop, someone is using the inode */
1131 	hammer_rel_inode(ip, 0);
1132 	return(res);
1133 }
1134 
1135 int
1136 hammer_unload_pseudofs(hammer_transaction_t trans, u_int32_t localization)
1137 {
1138 	int res;
1139 	int try;
1140 
1141 	for (try = res = 0; try < 4; ++try) {
1142 		res = hammer_ino_rb_tree_RB_SCAN(&trans->hmp->rb_inos_root,
1143 					   hammer_inode_pfs_cmp,
1144 					   hammer_unload_pseudofs_callback,
1145 					   &localization);
1146 		if (res == 0 && try > 1)
1147 			break;
1148 		hammer_flusher_sync(trans->hmp);
1149 	}
1150 	if (res != 0)
1151 		res = ENOTEMPTY;
1152 	return(res);
1153 }
1154 
1155 
1156 /*
1157  * Release a reference on a PFS
1158  */
1159 void
1160 hammer_rel_pseudofs(hammer_mount_t hmp, hammer_pseudofs_inmem_t pfsm)
1161 {
1162 	hammer_rel(&pfsm->lock);
1163 	if (hammer_norefs(&pfsm->lock)) {
1164 		RB_REMOVE(hammer_pfs_rb_tree, &hmp->rb_pfsm_root, pfsm);
1165 		kfree(pfsm, hmp->m_misc);
1166 	}
1167 }
1168 
1169 /*
1170  * Called by hammer_sync_inode().
1171  */
1172 static int
1173 hammer_update_inode(hammer_cursor_t cursor, hammer_inode_t ip)
1174 {
1175 	hammer_transaction_t trans = cursor->trans;
1176 	hammer_record_t record;
1177 	int error;
1178 	int redirty;
1179 
1180 retry:
1181 	error = 0;
1182 
1183 	/*
1184 	 * If the inode has a presence on-disk then locate it and mark
1185 	 * it deleted, setting DELONDISK.
1186 	 *
1187 	 * The record may or may not be physically deleted, depending on
1188 	 * the retention policy.
1189 	 */
1190 	if ((ip->flags & (HAMMER_INODE_ONDISK|HAMMER_INODE_DELONDISK)) ==
1191 	    HAMMER_INODE_ONDISK) {
1192 		hammer_normalize_cursor(cursor);
1193 		cursor->key_beg.localization = ip->obj_localization +
1194 					       HAMMER_LOCALIZE_INODE;
1195 		cursor->key_beg.obj_id = ip->obj_id;
1196 		cursor->key_beg.key = 0;
1197 		cursor->key_beg.create_tid = 0;
1198 		cursor->key_beg.delete_tid = 0;
1199 		cursor->key_beg.rec_type = HAMMER_RECTYPE_INODE;
1200 		cursor->key_beg.obj_type = 0;
1201 		cursor->asof = ip->obj_asof;
1202 		cursor->flags &= ~HAMMER_CURSOR_INITMASK;
1203 		cursor->flags |= HAMMER_CURSOR_GET_LEAF | HAMMER_CURSOR_ASOF;
1204 		cursor->flags |= HAMMER_CURSOR_BACKEND;
1205 
1206 		error = hammer_btree_lookup(cursor);
1207 		if (hammer_debug_inode)
1208 			kprintf("IPDEL %p %08x %d", ip, ip->flags, error);
1209 
1210 		if (error == 0) {
1211 			error = hammer_ip_delete_record(cursor, ip, trans->tid);
1212 			if (hammer_debug_inode)
1213 				kprintf(" error %d\n", error);
1214 			if (error == 0) {
1215 				ip->flags |= HAMMER_INODE_DELONDISK;
1216 			}
1217 			if (cursor->node)
1218 				hammer_cache_node(&ip->cache[0], cursor->node);
1219 		}
1220 		if (error == EDEADLK) {
1221 			hammer_done_cursor(cursor);
1222 			error = hammer_init_cursor(trans, cursor,
1223 						   &ip->cache[0], ip);
1224 			if (hammer_debug_inode)
1225 				kprintf("IPDED %p %d\n", ip, error);
1226 			if (error == 0)
1227 				goto retry;
1228 		}
1229 	}
1230 
1231 	/*
1232 	 * Ok, write out the initial record or a new record (after deleting
1233 	 * the old one), unless the DELETED flag is set.  This routine will
1234 	 * clear DELONDISK if it writes out a record.
1235 	 *
1236 	 * Update our inode statistics if this is the first application of
1237 	 * the inode on-disk.
1238 	 */
1239 	if (error == 0 && (ip->flags & HAMMER_INODE_DELETED) == 0) {
1240 		/*
1241 		 * Generate a record and write it to the media.  We clean-up
1242 		 * the state before releasing so we do not have to set-up
1243 		 * a flush_group.
1244 		 */
1245 		record = hammer_alloc_mem_record(ip, 0);
1246 		record->type = HAMMER_MEM_RECORD_INODE;
1247 		record->flush_state = HAMMER_FST_FLUSH;
1248 		record->leaf = ip->sync_ino_leaf;
1249 		record->leaf.base.create_tid = trans->tid;
1250 		record->leaf.data_len = sizeof(ip->sync_ino_data);
1251 		record->leaf.create_ts = trans->time32;
1252 		record->data = (void *)&ip->sync_ino_data;
1253 		record->flags |= HAMMER_RECF_INTERLOCK_BE;
1254 
1255 		/*
1256 		 * If this flag is set we cannot sync the new file size
1257 		 * because we haven't finished related truncations.  The
1258 		 * inode will be flushed in another flush group to finish
1259 		 * the job.
1260 		 */
1261 		if ((ip->flags & HAMMER_INODE_WOULDBLOCK) &&
1262 		    ip->sync_ino_data.size != ip->ino_data.size) {
1263 			redirty = 1;
1264 			ip->sync_ino_data.size = ip->ino_data.size;
1265 		} else {
1266 			redirty = 0;
1267 		}
1268 
1269 		for (;;) {
1270 			error = hammer_ip_sync_record_cursor(cursor, record);
1271 			if (hammer_debug_inode)
1272 				kprintf("GENREC %p rec %08x %d\n",
1273 					ip, record->flags, error);
1274 			if (error != EDEADLK)
1275 				break;
1276 			hammer_done_cursor(cursor);
1277 			error = hammer_init_cursor(trans, cursor,
1278 						   &ip->cache[0], ip);
1279 			if (hammer_debug_inode)
1280 				kprintf("GENREC reinit %d\n", error);
1281 			if (error)
1282 				break;
1283 		}
1284 
1285 		/*
1286 		 * Note:  The record was never on the inode's record tree
1287 		 * so just wave our hands importantly and destroy it.
1288 		 */
1289 		record->flags |= HAMMER_RECF_COMMITTED;
1290 		record->flags &= ~HAMMER_RECF_INTERLOCK_BE;
1291 		record->flush_state = HAMMER_FST_IDLE;
1292 		++ip->rec_generation;
1293 		hammer_rel_mem_record(record);
1294 
1295 		/*
1296 		 * Finish up.
1297 		 */
1298 		if (error == 0) {
1299 			if (hammer_debug_inode)
1300 				kprintf("CLEANDELOND %p %08x\n", ip, ip->flags);
1301 			ip->sync_flags &= ~(HAMMER_INODE_DDIRTY |
1302 					    HAMMER_INODE_SDIRTY |
1303 					    HAMMER_INODE_ATIME |
1304 					    HAMMER_INODE_MTIME);
1305 			ip->flags &= ~HAMMER_INODE_DELONDISK;
1306 			if (redirty)
1307 				ip->sync_flags |= HAMMER_INODE_DDIRTY;
1308 
1309 			/*
1310 			 * Root volume count of inodes
1311 			 */
1312 			hammer_sync_lock_sh(trans);
1313 			if ((ip->flags & HAMMER_INODE_ONDISK) == 0) {
1314 				hammer_modify_volume_field(trans,
1315 							   trans->rootvol,
1316 							   vol0_stat_inodes);
1317 				++ip->hmp->rootvol->ondisk->vol0_stat_inodes;
1318 				hammer_modify_volume_done(trans->rootvol);
1319 				ip->flags |= HAMMER_INODE_ONDISK;
1320 				if (hammer_debug_inode)
1321 					kprintf("NOWONDISK %p\n", ip);
1322 			}
1323 			hammer_sync_unlock(trans);
1324 		}
1325 	}
1326 
1327 	/*
1328 	 * If the inode has been destroyed, clean out any left-over flags
1329 	 * that may have been set by the frontend.
1330 	 */
1331 	if (error == 0 && (ip->flags & HAMMER_INODE_DELETED)) {
1332 		ip->sync_flags &= ~(HAMMER_INODE_DDIRTY |
1333 				    HAMMER_INODE_SDIRTY |
1334 				    HAMMER_INODE_ATIME |
1335 				    HAMMER_INODE_MTIME);
1336 	}
1337 	return(error);
1338 }
1339 
1340 /*
1341  * Update only the itimes fields.
1342  *
1343  * ATIME can be updated without generating any UNDO.  MTIME is updated
1344  * with UNDO so it is guaranteed to be synchronized properly in case of
1345  * a crash.
1346  *
1347  * Neither field is included in the B-Tree leaf element's CRC, which is how
1348  * we can get away with updating ATIME the way we do.
1349  */
1350 static int
1351 hammer_update_itimes(hammer_cursor_t cursor, hammer_inode_t ip)
1352 {
1353 	hammer_transaction_t trans = cursor->trans;
1354 	int error;
1355 
1356 retry:
1357 	if ((ip->flags & (HAMMER_INODE_ONDISK|HAMMER_INODE_DELONDISK)) !=
1358 	    HAMMER_INODE_ONDISK) {
1359 		return(0);
1360 	}
1361 
1362 	hammer_normalize_cursor(cursor);
1363 	cursor->key_beg.localization = ip->obj_localization +
1364 				       HAMMER_LOCALIZE_INODE;
1365 	cursor->key_beg.obj_id = ip->obj_id;
1366 	cursor->key_beg.key = 0;
1367 	cursor->key_beg.create_tid = 0;
1368 	cursor->key_beg.delete_tid = 0;
1369 	cursor->key_beg.rec_type = HAMMER_RECTYPE_INODE;
1370 	cursor->key_beg.obj_type = 0;
1371 	cursor->asof = ip->obj_asof;
1372 	cursor->flags &= ~HAMMER_CURSOR_INITMASK;
1373 	cursor->flags |= HAMMER_CURSOR_ASOF;
1374 	cursor->flags |= HAMMER_CURSOR_GET_LEAF;
1375 	cursor->flags |= HAMMER_CURSOR_GET_DATA;
1376 	cursor->flags |= HAMMER_CURSOR_BACKEND;
1377 
1378 	error = hammer_btree_lookup(cursor);
1379 	if (error == 0) {
1380 		hammer_cache_node(&ip->cache[0], cursor->node);
1381 		if (ip->sync_flags & HAMMER_INODE_MTIME) {
1382 			/*
1383 			 * Updating MTIME requires an UNDO.  Just cover
1384 			 * both atime and mtime.
1385 			 */
1386 			hammer_sync_lock_sh(trans);
1387 			hammer_modify_buffer(trans, cursor->data_buffer,
1388 				     HAMMER_ITIMES_BASE(&cursor->data->inode),
1389 				     HAMMER_ITIMES_BYTES);
1390 			cursor->data->inode.atime = ip->sync_ino_data.atime;
1391 			cursor->data->inode.mtime = ip->sync_ino_data.mtime;
1392 			hammer_modify_buffer_done(cursor->data_buffer);
1393 			hammer_sync_unlock(trans);
1394 		} else if (ip->sync_flags & HAMMER_INODE_ATIME) {
1395 			/*
1396 			 * Updating atime only can be done in-place with
1397 			 * no UNDO.
1398 			 */
1399 			hammer_sync_lock_sh(trans);
1400 			hammer_modify_buffer(trans, cursor->data_buffer,
1401 					     NULL, 0);
1402 			cursor->data->inode.atime = ip->sync_ino_data.atime;
1403 			hammer_modify_buffer_done(cursor->data_buffer);
1404 			hammer_sync_unlock(trans);
1405 		}
1406 		ip->sync_flags &= ~(HAMMER_INODE_ATIME | HAMMER_INODE_MTIME);
1407 	}
1408 	if (error == EDEADLK) {
1409 		hammer_done_cursor(cursor);
1410 		error = hammer_init_cursor(trans, cursor,
1411 					   &ip->cache[0], ip);
1412 		if (error == 0)
1413 			goto retry;
1414 	}
1415 	return(error);
1416 }
1417 
1418 /*
1419  * Release a reference on an inode, flush as requested.
1420  *
1421  * On the last reference we queue the inode to the flusher for its final
1422  * disposition.
1423  */
1424 void
1425 hammer_rel_inode(struct hammer_inode *ip, int flush)
1426 {
1427 	/*hammer_mount_t hmp = ip->hmp;*/
1428 
1429 	/*
1430 	 * Handle disposition when dropping the last ref.
1431 	 */
1432 	for (;;) {
1433 		if (hammer_oneref(&ip->lock)) {
1434 			/*
1435 			 * Determine whether on-disk action is needed for
1436 			 * the inode's final disposition.
1437 			 */
1438 			KKASSERT(ip->vp == NULL);
1439 			hammer_inode_unloadable_check(ip, 0);
1440 			if (ip->flags & HAMMER_INODE_MODMASK) {
1441 				hammer_flush_inode(ip, 0);
1442 			} else if (hammer_oneref(&ip->lock)) {
1443 				hammer_unload_inode(ip);
1444 				break;
1445 			}
1446 		} else {
1447 			if (flush)
1448 				hammer_flush_inode(ip, 0);
1449 
1450 			/*
1451 			 * The inode still has multiple refs, try to drop
1452 			 * one ref.
1453 			 */
1454 			KKASSERT(hammer_isactive(&ip->lock) >= 1);
1455 			if (hammer_isactive(&ip->lock) > 1) {
1456 				hammer_rel(&ip->lock);
1457 				break;
1458 			}
1459 		}
1460 	}
1461 }
1462 
1463 /*
1464  * Unload and destroy the specified inode.  Must be called with one remaining
1465  * reference.  The reference is disposed of.
1466  *
1467  * The inode must be completely clean.
1468  */
1469 static int
1470 hammer_unload_inode(struct hammer_inode *ip)
1471 {
1472 	hammer_mount_t hmp = ip->hmp;
1473 
1474 	KASSERT(hammer_oneref(&ip->lock),
1475 		("hammer_unload_inode: %d refs\n", hammer_isactive(&ip->lock)));
1476 	KKASSERT(ip->vp == NULL);
1477 	KKASSERT(ip->flush_state == HAMMER_FST_IDLE);
1478 	KKASSERT(ip->cursor_ip_refs == 0);
1479 	KKASSERT(hammer_notlocked(&ip->lock));
1480 	KKASSERT((ip->flags & HAMMER_INODE_MODMASK) == 0);
1481 
1482 	KKASSERT(RB_EMPTY(&ip->rec_tree));
1483 	KKASSERT(TAILQ_EMPTY(&ip->target_list));
1484 
1485 	if (ip->flags & HAMMER_INODE_RDIRTY) {
1486 		RB_REMOVE(hammer_redo_rb_tree, &hmp->rb_redo_root, ip);
1487 		ip->flags &= ~HAMMER_INODE_RDIRTY;
1488 	}
1489 	RB_REMOVE(hammer_ino_rb_tree, &hmp->rb_inos_root, ip);
1490 
1491 	hammer_free_inode(ip);
1492 	return(0);
1493 }
1494 
1495 /*
1496  * Called during unmounting if a critical error occured.  The in-memory
1497  * inode and all related structures are destroyed.
1498  *
1499  * If a critical error did not occur the unmount code calls the standard
1500  * release and asserts that the inode is gone.
1501  */
1502 int
1503 hammer_destroy_inode_callback(struct hammer_inode *ip, void *data __unused)
1504 {
1505 	hammer_record_t rec;
1506 
1507 	/*
1508 	 * Get rid of the inodes in-memory records, regardless of their
1509 	 * state, and clear the mod-mask.
1510 	 */
1511 	while ((rec = TAILQ_FIRST(&ip->target_list)) != NULL) {
1512 		TAILQ_REMOVE(&ip->target_list, rec, target_entry);
1513 		rec->target_ip = NULL;
1514 		if (rec->flush_state == HAMMER_FST_SETUP)
1515 			rec->flush_state = HAMMER_FST_IDLE;
1516 	}
1517 	while ((rec = RB_ROOT(&ip->rec_tree)) != NULL) {
1518 		if (rec->flush_state == HAMMER_FST_FLUSH)
1519 			--rec->flush_group->refs;
1520 		else
1521 			hammer_ref(&rec->lock);
1522 		KKASSERT(hammer_oneref(&rec->lock));
1523 		rec->flush_state = HAMMER_FST_IDLE;
1524 		rec->flush_group = NULL;
1525 		rec->flags |= HAMMER_RECF_DELETED_FE; /* wave hands */
1526 		rec->flags |= HAMMER_RECF_DELETED_BE; /* wave hands */
1527 		++ip->rec_generation;
1528 		hammer_rel_mem_record(rec);
1529 	}
1530 	ip->flags &= ~HAMMER_INODE_MODMASK;
1531 	ip->sync_flags &= ~HAMMER_INODE_MODMASK;
1532 	KKASSERT(ip->vp == NULL);
1533 
1534 	/*
1535 	 * Remove the inode from any flush group, force it idle.  FLUSH
1536 	 * and SETUP states have an inode ref.
1537 	 */
1538 	switch(ip->flush_state) {
1539 	case HAMMER_FST_FLUSH:
1540 		RB_REMOVE(hammer_fls_rb_tree, &ip->flush_group->flush_tree, ip);
1541 		--ip->flush_group->refs;
1542 		ip->flush_group = NULL;
1543 		/* fall through */
1544 	case HAMMER_FST_SETUP:
1545 		hammer_rel(&ip->lock);
1546 		ip->flush_state = HAMMER_FST_IDLE;
1547 		/* fall through */
1548 	case HAMMER_FST_IDLE:
1549 		break;
1550 	}
1551 
1552 	/*
1553 	 * There shouldn't be any associated vnode.  The unload needs at
1554 	 * least one ref, if we do have a vp steal its ip ref.
1555 	 */
1556 	if (ip->vp) {
1557 		kprintf("hammer_destroy_inode_callback: Unexpected "
1558 			"vnode association ip %p vp %p\n", ip, ip->vp);
1559 		ip->vp->v_data = NULL;
1560 		ip->vp = NULL;
1561 	} else {
1562 		hammer_ref(&ip->lock);
1563 	}
1564 	hammer_unload_inode(ip);
1565 	return(0);
1566 }
1567 
1568 /*
1569  * Called on mount -u when switching from RW to RO or vise-versa.  Adjust
1570  * the read-only flag for cached inodes.
1571  *
1572  * This routine is called from a RB_SCAN().
1573  */
1574 int
1575 hammer_reload_inode(hammer_inode_t ip, void *arg __unused)
1576 {
1577 	hammer_mount_t hmp = ip->hmp;
1578 
1579 	if (hmp->ronly || hmp->asof != HAMMER_MAX_TID)
1580 		ip->flags |= HAMMER_INODE_RO;
1581 	else
1582 		ip->flags &= ~HAMMER_INODE_RO;
1583 	return(0);
1584 }
1585 
1586 /*
1587  * A transaction has modified an inode, requiring updates as specified by
1588  * the passed flags.
1589  *
1590  * HAMMER_INODE_DDIRTY: Inode data has been updated, not incl mtime/atime,
1591  *			and not including size changes due to write-append
1592  *			(but other size changes are included).
1593  * HAMMER_INODE_SDIRTY: Inode data has been updated, size changes due to
1594  *			write-append.
1595  * HAMMER_INODE_XDIRTY: Dirty in-memory records
1596  * HAMMER_INODE_BUFS:   Dirty buffer cache buffers
1597  * HAMMER_INODE_DELETED: Inode record/data must be deleted
1598  * HAMMER_INODE_ATIME/MTIME: mtime/atime has been updated
1599  */
1600 void
1601 hammer_modify_inode(hammer_transaction_t trans, hammer_inode_t ip, int flags)
1602 {
1603 	/*
1604 	 * ronly of 0 or 2 does not trigger assertion.
1605 	 * 2 is a special error state
1606 	 */
1607 	KKASSERT(ip->hmp->ronly != 1 ||
1608 		  (flags & (HAMMER_INODE_DDIRTY | HAMMER_INODE_XDIRTY |
1609 			    HAMMER_INODE_SDIRTY |
1610 			    HAMMER_INODE_BUFS | HAMMER_INODE_DELETED |
1611 			    HAMMER_INODE_ATIME | HAMMER_INODE_MTIME)) == 0);
1612 	if ((ip->flags & HAMMER_INODE_RSV_INODES) == 0) {
1613 		ip->flags |= HAMMER_INODE_RSV_INODES;
1614 		++ip->hmp->rsv_inodes;
1615 	}
1616 
1617 	/*
1618 	 * Set the NEWINODE flag in the transaction if the inode
1619 	 * transitions to a dirty state.  This is used to track
1620 	 * the load on the inode cache.
1621 	 */
1622 	if (trans &&
1623 	    (ip->flags & HAMMER_INODE_MODMASK) == 0 &&
1624 	    (flags & HAMMER_INODE_MODMASK)) {
1625 		trans->flags |= HAMMER_TRANSF_NEWINODE;
1626 	}
1627 
1628 	ip->flags |= flags;
1629 }
1630 
1631 /*
1632  * Request that an inode be flushed.  This whole mess cannot block and may
1633  * recurse (if not synchronous).  Once requested HAMMER will attempt to
1634  * actively flush the inode until the flush can be done.
1635  *
1636  * The inode may already be flushing, or may be in a setup state.  We can
1637  * place the inode in a flushing state if it is currently idle and flag it
1638  * to reflush if it is currently flushing.
1639  *
1640  * Upon return if the inode could not be flushed due to a setup
1641  * dependancy, then it will be automatically flushed when the dependancy
1642  * is satisfied.
1643  */
1644 void
1645 hammer_flush_inode(hammer_inode_t ip, int flags)
1646 {
1647 	hammer_mount_t hmp;
1648 	hammer_flush_group_t flg;
1649 	int good;
1650 
1651 	/*
1652 	 * next_flush_group is the first flush group we can place the inode
1653 	 * in.  It may be NULL.  If it becomes full we append a new flush
1654 	 * group and make that the next_flush_group.
1655 	 */
1656 	hmp = ip->hmp;
1657 	while ((flg = hmp->next_flush_group) != NULL) {
1658 		KKASSERT(flg->running == 0);
1659 		if (flg->total_count + flg->refs <= ip->hmp->undo_rec_limit)
1660 			break;
1661 		hmp->next_flush_group = TAILQ_NEXT(flg, flush_entry);
1662 		hammer_flusher_async(ip->hmp, flg);
1663 	}
1664 	if (flg == NULL) {
1665 		flg = kmalloc(sizeof(*flg), hmp->m_misc, M_WAITOK|M_ZERO);
1666 		hmp->next_flush_group = flg;
1667 		RB_INIT(&flg->flush_tree);
1668 		TAILQ_INSERT_TAIL(&hmp->flush_group_list, flg, flush_entry);
1669 	}
1670 
1671 	/*
1672 	 * Trivial 'nothing to flush' case.  If the inode is in a SETUP
1673 	 * state we have to put it back into an IDLE state so we can
1674 	 * drop the extra ref.
1675 	 *
1676 	 * If we have a parent dependancy we must still fall through
1677 	 * so we can run it.
1678 	 */
1679 	if ((ip->flags & HAMMER_INODE_MODMASK) == 0) {
1680 		if (ip->flush_state == HAMMER_FST_SETUP &&
1681 		    TAILQ_EMPTY(&ip->target_list)) {
1682 			ip->flush_state = HAMMER_FST_IDLE;
1683 			hammer_rel_inode(ip, 0);
1684 		}
1685 		if (ip->flush_state == HAMMER_FST_IDLE)
1686 			return;
1687 	}
1688 
1689 	/*
1690 	 * Our flush action will depend on the current state.
1691 	 */
1692 	switch(ip->flush_state) {
1693 	case HAMMER_FST_IDLE:
1694 		/*
1695 		 * We have no dependancies and can flush immediately.  Some
1696 		 * our children may not be flushable so we have to re-test
1697 		 * with that additional knowledge.
1698 		 */
1699 		hammer_flush_inode_core(ip, flg, flags);
1700 		break;
1701 	case HAMMER_FST_SETUP:
1702 		/*
1703 		 * Recurse upwards through dependancies via target_list
1704 		 * and start their flusher actions going if possible.
1705 		 *
1706 		 * 'good' is our connectivity.  -1 means we have none and
1707 		 * can't flush, 0 means there weren't any dependancies, and
1708 		 * 1 means we have good connectivity.
1709 		 */
1710 		good = hammer_setup_parent_inodes(ip, 0, flg);
1711 
1712 		if (good >= 0) {
1713 			/*
1714 			 * We can continue if good >= 0.  Determine how
1715 			 * many records under our inode can be flushed (and
1716 			 * mark them).
1717 			 */
1718 			hammer_flush_inode_core(ip, flg, flags);
1719 		} else {
1720 			/*
1721 			 * Parent has no connectivity, tell it to flush
1722 			 * us as soon as it does.
1723 			 *
1724 			 * The REFLUSH flag is also needed to trigger
1725 			 * dependancy wakeups.
1726 			 */
1727 			ip->flags |= HAMMER_INODE_CONN_DOWN |
1728 				     HAMMER_INODE_REFLUSH;
1729 			if (flags & HAMMER_FLUSH_SIGNAL) {
1730 				ip->flags |= HAMMER_INODE_RESIGNAL;
1731 				hammer_flusher_async(ip->hmp, flg);
1732 			}
1733 		}
1734 		break;
1735 	case HAMMER_FST_FLUSH:
1736 		/*
1737 		 * We are already flushing, flag the inode to reflush
1738 		 * if needed after it completes its current flush.
1739 		 *
1740 		 * The REFLUSH flag is also needed to trigger
1741 		 * dependancy wakeups.
1742 		 */
1743 		if ((ip->flags & HAMMER_INODE_REFLUSH) == 0)
1744 			ip->flags |= HAMMER_INODE_REFLUSH;
1745 		if (flags & HAMMER_FLUSH_SIGNAL) {
1746 			ip->flags |= HAMMER_INODE_RESIGNAL;
1747 			hammer_flusher_async(ip->hmp, flg);
1748 		}
1749 		break;
1750 	}
1751 }
1752 
1753 /*
1754  * Scan ip->target_list, which is a list of records owned by PARENTS to our
1755  * ip which reference our ip.
1756  *
1757  * XXX This is a huge mess of recursive code, but not one bit of it blocks
1758  *     so for now do not ref/deref the structures.  Note that if we use the
1759  *     ref/rel code later, the rel CAN block.
1760  */
1761 static int
1762 hammer_setup_parent_inodes(hammer_inode_t ip, int depth,
1763 			   hammer_flush_group_t flg)
1764 {
1765 	hammer_record_t depend;
1766 	int good;
1767 	int r;
1768 
1769 	/*
1770 	 * If we hit our recursion limit and we have parent dependencies
1771 	 * We cannot continue.  Returning < 0 will cause us to be flagged
1772 	 * for reflush.  Returning -2 cuts off additional dependency checks
1773 	 * because they are likely to also hit the depth limit.
1774 	 *
1775 	 * We cannot return < 0 if there are no dependencies or there might
1776 	 * not be anything to wakeup (ip).
1777 	 */
1778 	if (depth == 20 && TAILQ_FIRST(&ip->target_list)) {
1779 		kprintf("HAMMER Warning: depth limit reached on "
1780 			"setup recursion, inode %p %016llx\n",
1781 			ip, (long long)ip->obj_id);
1782 		return(-2);
1783 	}
1784 
1785 	/*
1786 	 * Scan dependencies
1787 	 */
1788 	good = 0;
1789 	TAILQ_FOREACH(depend, &ip->target_list, target_entry) {
1790 		r = hammer_setup_parent_inodes_helper(depend, depth, flg);
1791 		KKASSERT(depend->target_ip == ip);
1792 		if (r < 0 && good == 0)
1793 			good = -1;
1794 		if (r > 0)
1795 			good = 1;
1796 
1797 		/*
1798 		 * If we failed due to the recursion depth limit then stop
1799 		 * now.
1800 		 */
1801 		if (r == -2)
1802 			break;
1803 	}
1804 	return(good);
1805 }
1806 
1807 /*
1808  * This helper function takes a record representing the dependancy between
1809  * the parent inode and child inode.
1810  *
1811  * record->ip		= parent inode
1812  * record->target_ip	= child inode
1813  *
1814  * We are asked to recurse upwards and convert the record from SETUP
1815  * to FLUSH if possible.
1816  *
1817  * Return 1 if the record gives us connectivity
1818  *
1819  * Return 0 if the record is not relevant
1820  *
1821  * Return -1 if we can't resolve the dependancy and there is no connectivity.
1822  */
1823 static int
1824 hammer_setup_parent_inodes_helper(hammer_record_t record, int depth,
1825 				  hammer_flush_group_t flg)
1826 {
1827 	hammer_mount_t hmp;
1828 	hammer_inode_t pip;
1829 	int good;
1830 
1831 	KKASSERT(record->flush_state != HAMMER_FST_IDLE);
1832 	pip = record->ip;
1833 	hmp = pip->hmp;
1834 
1835 	/*
1836 	 * If the record is already flushing, is it in our flush group?
1837 	 *
1838 	 * If it is in our flush group but it is a general record or a
1839 	 * delete-on-disk, it does not improve our connectivity (return 0),
1840 	 * and if the target inode is not trying to destroy itself we can't
1841 	 * allow the operation yet anyway (the second return -1).
1842 	 */
1843 	if (record->flush_state == HAMMER_FST_FLUSH) {
1844 		/*
1845 		 * If not in our flush group ask the parent to reflush
1846 		 * us as soon as possible.
1847 		 */
1848 		if (record->flush_group != flg) {
1849 			pip->flags |= HAMMER_INODE_REFLUSH;
1850 			record->target_ip->flags |= HAMMER_INODE_CONN_DOWN;
1851 			return(-1);
1852 		}
1853 
1854 		/*
1855 		 * If in our flush group everything is already set up,
1856 		 * just return whether the record will improve our
1857 		 * visibility or not.
1858 		 */
1859 		if (record->type == HAMMER_MEM_RECORD_ADD)
1860 			return(1);
1861 		return(0);
1862 	}
1863 
1864 	/*
1865 	 * It must be a setup record.  Try to resolve the setup dependancies
1866 	 * by recursing upwards so we can place ip on the flush list.
1867 	 *
1868 	 * Limit ourselves to 20 levels of recursion to avoid blowing out
1869 	 * the kernel stack.  If we hit the recursion limit we can't flush
1870 	 * until the parent flushes.  The parent will flush independantly
1871 	 * on its own and ultimately a deep recursion will be resolved.
1872 	 */
1873 	KKASSERT(record->flush_state == HAMMER_FST_SETUP);
1874 
1875 	good = hammer_setup_parent_inodes(pip, depth + 1, flg);
1876 
1877 	/*
1878 	 * If good < 0 the parent has no connectivity and we cannot safely
1879 	 * flush the directory entry, which also means we can't flush our
1880 	 * ip.  Flag us for downward recursion once the parent's
1881 	 * connectivity is resolved.  Flag the parent for [re]flush or it
1882 	 * may not check for downward recursions.
1883 	 */
1884 	if (good < 0) {
1885 		pip->flags |= HAMMER_INODE_REFLUSH;
1886 		record->target_ip->flags |= HAMMER_INODE_CONN_DOWN;
1887 		return(good);
1888 	}
1889 
1890 	/*
1891 	 * We are go, place the parent inode in a flushing state so we can
1892 	 * place its record in a flushing state.  Note that the parent
1893 	 * may already be flushing.  The record must be in the same flush
1894 	 * group as the parent.
1895 	 */
1896 	if (pip->flush_state != HAMMER_FST_FLUSH)
1897 		hammer_flush_inode_core(pip, flg, HAMMER_FLUSH_RECURSION);
1898 	KKASSERT(pip->flush_state == HAMMER_FST_FLUSH);
1899 
1900 	/*
1901 	 * It is possible for a rename to create a loop in the recursion
1902 	 * and revisit a record.  This will result in the record being
1903 	 * placed in a flush state unexpectedly.  This check deals with
1904 	 * the case.
1905 	 */
1906 	if (record->flush_state == HAMMER_FST_FLUSH) {
1907 		if (record->type == HAMMER_MEM_RECORD_ADD)
1908 			return(1);
1909 		return(0);
1910 	}
1911 
1912 	KKASSERT(record->flush_state == HAMMER_FST_SETUP);
1913 
1914 #if 0
1915 	if (record->type == HAMMER_MEM_RECORD_DEL &&
1916 	    (record->target_ip->flags & (HAMMER_INODE_DELETED|HAMMER_INODE_DELONDISK)) == 0) {
1917 		/*
1918 		 * Regardless of flushing state we cannot sync this path if the
1919 		 * record represents a delete-on-disk but the target inode
1920 		 * is not ready to sync its own deletion.
1921 		 *
1922 		 * XXX need to count effective nlinks to determine whether
1923 		 * the flush is ok, otherwise removing a hardlink will
1924 		 * just leave the DEL record to rot.
1925 		 */
1926 		record->target_ip->flags |= HAMMER_INODE_REFLUSH;
1927 		return(-1);
1928 	} else
1929 #endif
1930 	if (pip->flush_group == flg) {
1931 		/*
1932 		 * Because we have not calculated nlinks yet we can just
1933 		 * set records to the flush state if the parent is in
1934 		 * the same flush group as we are.
1935 		 */
1936 		record->flush_state = HAMMER_FST_FLUSH;
1937 		record->flush_group = flg;
1938 		++record->flush_group->refs;
1939 		hammer_ref(&record->lock);
1940 
1941 		/*
1942 		 * A general directory-add contributes to our visibility.
1943 		 *
1944 		 * Otherwise it is probably a directory-delete or
1945 		 * delete-on-disk record and does not contribute to our
1946 		 * visbility (but we can still flush it).
1947 		 */
1948 		if (record->type == HAMMER_MEM_RECORD_ADD)
1949 			return(1);
1950 		return(0);
1951 	} else {
1952 		/*
1953 		 * If the parent is not in our flush group we cannot
1954 		 * flush this record yet, there is no visibility.
1955 		 * We tell the parent to reflush and mark ourselves
1956 		 * so the parent knows it should flush us too.
1957 		 */
1958 		pip->flags |= HAMMER_INODE_REFLUSH;
1959 		record->target_ip->flags |= HAMMER_INODE_CONN_DOWN;
1960 		return(-1);
1961 	}
1962 }
1963 
1964 /*
1965  * This is the core routine placing an inode into the FST_FLUSH state.
1966  */
1967 static void
1968 hammer_flush_inode_core(hammer_inode_t ip, hammer_flush_group_t flg, int flags)
1969 {
1970 	int go_count;
1971 
1972 	/*
1973 	 * Set flush state and prevent the flusher from cycling into
1974 	 * the next flush group.  Do not place the ip on the list yet.
1975 	 * Inodes not in the idle state get an extra reference.
1976 	 */
1977 	KKASSERT(ip->flush_state != HAMMER_FST_FLUSH);
1978 	if (ip->flush_state == HAMMER_FST_IDLE)
1979 		hammer_ref(&ip->lock);
1980 	ip->flush_state = HAMMER_FST_FLUSH;
1981 	ip->flush_group = flg;
1982 	++ip->hmp->flusher.group_lock;
1983 	++ip->hmp->count_iqueued;
1984 	++hammer_count_iqueued;
1985 	++flg->total_count;
1986 	hammer_redo_fifo_start_flush(ip);
1987 
1988 	/*
1989 	 * If the flush group reaches the autoflush limit we want to signal
1990 	 * the flusher.  This is particularly important for remove()s.
1991 	 *
1992 	 * If the default hammer_limit_reclaim is changed via sysctl
1993 	 * make sure we don't hit a degenerate case where we don't start
1994 	 * a flush but blocked on further inode ops.
1995 	 */
1996 	if (flg->total_count == hammer_autoflush ||
1997 	    flg->total_count >= hammer_limit_reclaim / 4)
1998 		flags |= HAMMER_FLUSH_SIGNAL;
1999 
2000 #if 0
2001 	/*
2002 	 * We need to be able to vfsync/truncate from the backend.
2003 	 *
2004 	 * XXX Any truncation from the backend will acquire the vnode
2005 	 *     independently.
2006 	 */
2007 	KKASSERT((ip->flags & HAMMER_INODE_VHELD) == 0);
2008 	if (ip->vp && (ip->vp->v_flag & VINACTIVE) == 0) {
2009 		ip->flags |= HAMMER_INODE_VHELD;
2010 		vref(ip->vp);
2011 	}
2012 #endif
2013 
2014 	/*
2015 	 * Figure out how many in-memory records we can actually flush
2016 	 * (not including inode meta-data, buffers, etc).
2017 	 */
2018 	KKASSERT((ip->flags & HAMMER_INODE_WOULDBLOCK) == 0);
2019 	if (flags & HAMMER_FLUSH_RECURSION) {
2020 		/*
2021 		 * If this is a upwards recursion we do not want to
2022 		 * recurse down again!
2023 		 */
2024 		go_count = 1;
2025 #if 0
2026 	} else if (ip->flags & HAMMER_INODE_WOULDBLOCK) {
2027 		/*
2028 		 * No new records are added if we must complete a flush
2029 		 * from a previous cycle, but we do have to move the records
2030 		 * from the previous cycle to the current one.
2031 		 */
2032 #if 0
2033 		go_count = RB_SCAN(hammer_rec_rb_tree, &ip->rec_tree, NULL,
2034 				   hammer_syncgrp_child_callback, NULL);
2035 #endif
2036 		go_count = 1;
2037 #endif
2038 	} else {
2039 		/*
2040 		 * Normal flush, scan records and bring them into the flush.
2041 		 * Directory adds and deletes are usually skipped (they are
2042 		 * grouped with the related inode rather then with the
2043 		 * directory).
2044 		 *
2045 		 * go_count can be negative, which means the scan aborted
2046 		 * due to the flush group being over-full and we should
2047 		 * flush what we have.
2048 		 */
2049 		go_count = RB_SCAN(hammer_rec_rb_tree, &ip->rec_tree, NULL,
2050 				   hammer_setup_child_callback, NULL);
2051 	}
2052 
2053 	/*
2054 	 * This is a more involved test that includes go_count.  If we
2055 	 * can't flush, flag the inode and return.  If go_count is 0 we
2056 	 * were are unable to flush any records in our rec_tree and
2057 	 * must ignore the XDIRTY flag.
2058 	 */
2059 	if (go_count == 0) {
2060 		if ((ip->flags & HAMMER_INODE_MODMASK_NOXDIRTY) == 0) {
2061 			--ip->hmp->count_iqueued;
2062 			--hammer_count_iqueued;
2063 
2064 			--flg->total_count;
2065 			ip->flush_state = HAMMER_FST_SETUP;
2066 			ip->flush_group = NULL;
2067 #if 0
2068 			if (ip->flags & HAMMER_INODE_VHELD) {
2069 				ip->flags &= ~HAMMER_INODE_VHELD;
2070 				vrele(ip->vp);
2071 			}
2072 #endif
2073 
2074 			/*
2075 			 * REFLUSH is needed to trigger dependancy wakeups
2076 			 * when an inode is in SETUP.
2077 			 */
2078 			ip->flags |= HAMMER_INODE_REFLUSH;
2079 			if (flags & HAMMER_FLUSH_SIGNAL) {
2080 				ip->flags |= HAMMER_INODE_RESIGNAL;
2081 				hammer_flusher_async(ip->hmp, flg);
2082 			}
2083 			if (--ip->hmp->flusher.group_lock == 0)
2084 				wakeup(&ip->hmp->flusher.group_lock);
2085 			return;
2086 		}
2087 	}
2088 
2089 	/*
2090 	 * Snapshot the state of the inode for the backend flusher.
2091 	 *
2092 	 * We continue to retain save_trunc_off even when all truncations
2093 	 * have been resolved as an optimization to determine if we can
2094 	 * skip the B-Tree lookup for overwrite deletions.
2095 	 *
2096 	 * NOTE: The DELETING flag is a mod flag, but it is also sticky,
2097 	 * and stays in ip->flags.  Once set, it stays set until the
2098 	 * inode is destroyed.
2099 	 */
2100 	if (ip->flags & HAMMER_INODE_TRUNCATED) {
2101 		KKASSERT((ip->sync_flags & HAMMER_INODE_TRUNCATED) == 0);
2102 		ip->sync_trunc_off = ip->trunc_off;
2103 		ip->trunc_off = 0x7FFFFFFFFFFFFFFFLL;
2104 		ip->flags &= ~HAMMER_INODE_TRUNCATED;
2105 		ip->sync_flags |= HAMMER_INODE_TRUNCATED;
2106 
2107 		/*
2108 		 * The save_trunc_off used to cache whether the B-Tree
2109 		 * holds any records past that point is not used until
2110 		 * after the truncation has succeeded, so we can safely
2111 		 * set it now.
2112 		 */
2113 		if (ip->save_trunc_off > ip->sync_trunc_off)
2114 			ip->save_trunc_off = ip->sync_trunc_off;
2115 	}
2116 	ip->sync_flags |= (ip->flags & HAMMER_INODE_MODMASK &
2117 			   ~HAMMER_INODE_TRUNCATED);
2118 	ip->sync_ino_leaf = ip->ino_leaf;
2119 	ip->sync_ino_data = ip->ino_data;
2120 	ip->flags &= ~HAMMER_INODE_MODMASK | HAMMER_INODE_TRUNCATED;
2121 #ifdef DEBUG_TRUNCATE
2122 	if ((ip->sync_flags & HAMMER_INODE_TRUNCATED) && ip == HammerTruncIp)
2123 		kprintf("truncateS %016llx\n", ip->sync_trunc_off);
2124 #endif
2125 
2126 	/*
2127 	 * The flusher list inherits our inode and reference.
2128 	 */
2129 	KKASSERT(flg->running == 0);
2130 	RB_INSERT(hammer_fls_rb_tree, &flg->flush_tree, ip);
2131 	if (--ip->hmp->flusher.group_lock == 0)
2132 		wakeup(&ip->hmp->flusher.group_lock);
2133 
2134 	if (flags & HAMMER_FLUSH_SIGNAL) {
2135 		hammer_flusher_async(ip->hmp, flg);
2136 	}
2137 }
2138 
2139 /*
2140  * Callback for scan of ip->rec_tree.  Try to include each record in our
2141  * flush.  ip->flush_group has been set but the inode has not yet been
2142  * moved into a flushing state.
2143  *
2144  * If we get stuck on a record we have to set HAMMER_INODE_REFLUSH on
2145  * both inodes.
2146  *
2147  * We return 1 for any record placed or found in FST_FLUSH, which prevents
2148  * the caller from shortcutting the flush.
2149  */
2150 static int
2151 hammer_setup_child_callback(hammer_record_t rec, void *data)
2152 {
2153 	hammer_flush_group_t flg;
2154 	hammer_inode_t target_ip;
2155 	hammer_inode_t ip;
2156 	int r;
2157 
2158 	/*
2159 	 * Records deleted or committed by the backend are ignored.
2160 	 * Note that the flush detects deleted frontend records at
2161 	 * multiple points to deal with races.  This is just the first
2162 	 * line of defense.  The only time HAMMER_RECF_DELETED_FE cannot
2163 	 * be set is when HAMMER_RECF_INTERLOCK_BE is set, because it
2164 	 * messes up link-count calculations.
2165 	 *
2166 	 * NOTE: Don't get confused between record deletion and, say,
2167 	 * directory entry deletion.  The deletion of a directory entry
2168 	 * which is on-media has nothing to do with the record deletion
2169 	 * flags.
2170 	 */
2171 	if (rec->flags & (HAMMER_RECF_DELETED_FE | HAMMER_RECF_DELETED_BE |
2172 			  HAMMER_RECF_COMMITTED)) {
2173 		if (rec->flush_state == HAMMER_FST_FLUSH) {
2174 			KKASSERT(rec->flush_group == rec->ip->flush_group);
2175 			r = 1;
2176 		} else {
2177 			r = 0;
2178 		}
2179 		return(r);
2180 	}
2181 
2182 	/*
2183 	 * If the record is in an idle state it has no dependancies and
2184 	 * can be flushed.
2185 	 */
2186 	ip = rec->ip;
2187 	flg = ip->flush_group;
2188 	r = 0;
2189 
2190 	switch(rec->flush_state) {
2191 	case HAMMER_FST_IDLE:
2192 		/*
2193 		 * The record has no setup dependancy, we can flush it.
2194 		 */
2195 		KKASSERT(rec->target_ip == NULL);
2196 		rec->flush_state = HAMMER_FST_FLUSH;
2197 		rec->flush_group = flg;
2198 		++flg->refs;
2199 		hammer_ref(&rec->lock);
2200 		r = 1;
2201 		break;
2202 	case HAMMER_FST_SETUP:
2203 		/*
2204 		 * The record has a setup dependancy.  These are typically
2205 		 * directory entry adds and deletes.  Such entries will be
2206 		 * flushed when their inodes are flushed so we do not
2207 		 * usually have to add them to the flush here.  However,
2208 		 * if the target_ip has set HAMMER_INODE_CONN_DOWN then
2209 		 * it is asking us to flush this record (and it).
2210 		 */
2211 		target_ip = rec->target_ip;
2212 		KKASSERT(target_ip != NULL);
2213 		KKASSERT(target_ip->flush_state != HAMMER_FST_IDLE);
2214 
2215 		/*
2216 		 * If the target IP is already flushing in our group
2217 		 * we could associate the record, but target_ip has
2218 		 * already synced ino_data to sync_ino_data and we
2219 		 * would also have to adjust nlinks.   Plus there are
2220 		 * ordering issues for adds and deletes.
2221 		 *
2222 		 * Reflush downward if this is an ADD, and upward if
2223 		 * this is a DEL.
2224 		 */
2225 		if (target_ip->flush_state == HAMMER_FST_FLUSH) {
2226 			if (rec->flush_state == HAMMER_MEM_RECORD_ADD)
2227 				ip->flags |= HAMMER_INODE_REFLUSH;
2228 			else
2229 				target_ip->flags |= HAMMER_INODE_REFLUSH;
2230 			break;
2231 		}
2232 
2233 		/*
2234 		 * Target IP is not yet flushing.  This can get complex
2235 		 * because we have to be careful about the recursion.
2236 		 *
2237 		 * Directories create an issue for us in that if a flush
2238 		 * of a directory is requested the expectation is to flush
2239 		 * any pending directory entries, but this will cause the
2240 		 * related inodes to recursively flush as well.  We can't
2241 		 * really defer the operation so just get as many as we
2242 		 * can and
2243 		 */
2244 #if 0
2245 		if ((target_ip->flags & HAMMER_INODE_RECLAIM) == 0 &&
2246 		    (target_ip->flags & HAMMER_INODE_CONN_DOWN) == 0) {
2247 			/*
2248 			 * We aren't reclaiming and the target ip was not
2249 			 * previously prevented from flushing due to this
2250 			 * record dependancy.  Do not flush this record.
2251 			 */
2252 			/*r = 0;*/
2253 		} else
2254 #endif
2255 		if (flg->total_count + flg->refs >
2256 			   ip->hmp->undo_rec_limit) {
2257 			/*
2258 			 * Our flush group is over-full and we risk blowing
2259 			 * out the UNDO FIFO.  Stop the scan, flush what we
2260 			 * have, then reflush the directory.
2261 			 *
2262 			 * The directory may be forced through multiple
2263 			 * flush groups before it can be completely
2264 			 * flushed.
2265 			 */
2266 			ip->flags |= HAMMER_INODE_RESIGNAL |
2267 				     HAMMER_INODE_REFLUSH;
2268 			r = -1;
2269 		} else if (rec->type == HAMMER_MEM_RECORD_ADD) {
2270 			/*
2271 			 * If the target IP is not flushing we can force
2272 			 * it to flush, even if it is unable to write out
2273 			 * any of its own records we have at least one in
2274 			 * hand that we CAN deal with.
2275 			 */
2276 			rec->flush_state = HAMMER_FST_FLUSH;
2277 			rec->flush_group = flg;
2278 			++flg->refs;
2279 			hammer_ref(&rec->lock);
2280 			hammer_flush_inode_core(target_ip, flg,
2281 						HAMMER_FLUSH_RECURSION);
2282 			r = 1;
2283 		} else {
2284 			/*
2285 			 * General or delete-on-disk record.
2286 			 *
2287 			 * XXX this needs help.  If a delete-on-disk we could
2288 			 * disconnect the target.  If the target has its own
2289 			 * dependancies they really need to be flushed.
2290 			 *
2291 			 * XXX
2292 			 */
2293 			rec->flush_state = HAMMER_FST_FLUSH;
2294 			rec->flush_group = flg;
2295 			++flg->refs;
2296 			hammer_ref(&rec->lock);
2297 			hammer_flush_inode_core(target_ip, flg,
2298 						HAMMER_FLUSH_RECURSION);
2299 			r = 1;
2300 		}
2301 		break;
2302 	case HAMMER_FST_FLUSH:
2303 		/*
2304 		 * The record could be part of a previous flush group if the
2305 		 * inode is a directory (the record being a directory entry).
2306 		 * Once the flush group was closed a hammer_test_inode()
2307 		 * function can cause a new flush group to be setup, placing
2308 		 * the directory inode itself in a new flush group.
2309 		 *
2310 		 * When associated with a previous flush group we count it
2311 		 * as if it were in our current flush group, since it will
2312 		 * effectively be flushed by the time we flush our current
2313 		 * flush group.
2314 		 */
2315 		KKASSERT(
2316 		    rec->ip->ino_data.obj_type == HAMMER_OBJTYPE_DIRECTORY ||
2317 		    rec->flush_group == flg);
2318 		r = 1;
2319 		break;
2320 	}
2321 	return(r);
2322 }
2323 
2324 #if 0
2325 /*
2326  * This version just moves records already in a flush state to the new
2327  * flush group and that is it.
2328  */
2329 static int
2330 hammer_syncgrp_child_callback(hammer_record_t rec, void *data)
2331 {
2332 	hammer_inode_t ip = rec->ip;
2333 
2334 	switch(rec->flush_state) {
2335 	case HAMMER_FST_FLUSH:
2336 		KKASSERT(rec->flush_group == ip->flush_group);
2337 		break;
2338 	default:
2339 		break;
2340 	}
2341 	return(0);
2342 }
2343 #endif
2344 
2345 /*
2346  * Wait for a previously queued flush to complete.
2347  *
2348  * If a critical error occured we don't try to wait.
2349  */
2350 void
2351 hammer_wait_inode(hammer_inode_t ip)
2352 {
2353 	hammer_flush_group_t flg;
2354 
2355 	flg = NULL;
2356 	if ((ip->hmp->flags & HAMMER_MOUNT_CRITICAL_ERROR) == 0) {
2357 		while (ip->flush_state != HAMMER_FST_IDLE &&
2358 		       (ip->hmp->flags & HAMMER_MOUNT_CRITICAL_ERROR) == 0) {
2359 			if (ip->flush_state == HAMMER_FST_SETUP)
2360 				hammer_flush_inode(ip, HAMMER_FLUSH_SIGNAL);
2361 			if (ip->flush_state != HAMMER_FST_IDLE) {
2362 				ip->flags |= HAMMER_INODE_FLUSHW;
2363 				tsleep(&ip->flags, 0, "hmrwin", 0);
2364 			}
2365 		}
2366 	}
2367 }
2368 
2369 /*
2370  * Called by the backend code when a flush has been completed.
2371  * The inode has already been removed from the flush list.
2372  *
2373  * A pipelined flush can occur, in which case we must re-enter the
2374  * inode on the list and re-copy its fields.
2375  */
2376 void
2377 hammer_flush_inode_done(hammer_inode_t ip, int error)
2378 {
2379 	hammer_mount_t hmp;
2380 	int dorel;
2381 
2382 	KKASSERT(ip->flush_state == HAMMER_FST_FLUSH);
2383 
2384 	hmp = ip->hmp;
2385 
2386 	/*
2387 	 * Auto-reflush if the backend could not completely flush
2388 	 * the inode.  This fixes a case where a deferred buffer flush
2389 	 * could cause fsync to return early.
2390 	 */
2391 	if (ip->sync_flags & HAMMER_INODE_MODMASK)
2392 		ip->flags |= HAMMER_INODE_REFLUSH;
2393 
2394 	/*
2395 	 * Merge left-over flags back into the frontend and fix the state.
2396 	 * Incomplete truncations are retained by the backend.
2397 	 */
2398 	ip->error = error;
2399 	ip->flags |= ip->sync_flags & ~HAMMER_INODE_TRUNCATED;
2400 	ip->sync_flags &= HAMMER_INODE_TRUNCATED;
2401 
2402 	/*
2403 	 * The backend may have adjusted nlinks, so if the adjusted nlinks
2404 	 * does not match the fronttend set the frontend's DDIRTY flag again.
2405 	 */
2406 	if (ip->ino_data.nlinks != ip->sync_ino_data.nlinks)
2407 		ip->flags |= HAMMER_INODE_DDIRTY;
2408 
2409 	/*
2410 	 * Fix up the dirty buffer status.
2411 	 */
2412 	if (ip->vp && RB_ROOT(&ip->vp->v_rbdirty_tree)) {
2413 		ip->flags |= HAMMER_INODE_BUFS;
2414 	}
2415 	hammer_redo_fifo_end_flush(ip);
2416 
2417 	/*
2418 	 * Re-set the XDIRTY flag if some of the inode's in-memory records
2419 	 * could not be flushed.
2420 	 */
2421 	KKASSERT((RB_EMPTY(&ip->rec_tree) &&
2422 		  (ip->flags & HAMMER_INODE_XDIRTY) == 0) ||
2423 		 (!RB_EMPTY(&ip->rec_tree) &&
2424 		  (ip->flags & HAMMER_INODE_XDIRTY) != 0));
2425 
2426 	/*
2427 	 * Do not lose track of inodes which no longer have vnode
2428 	 * assocations, otherwise they may never get flushed again.
2429 	 *
2430 	 * The reflush flag can be set superfluously, causing extra pain
2431 	 * for no reason.  If the inode is no longer modified it no longer
2432 	 * needs to be flushed.
2433 	 */
2434 	if (ip->flags & HAMMER_INODE_MODMASK) {
2435 		if (ip->vp == NULL)
2436 			ip->flags |= HAMMER_INODE_REFLUSH;
2437 	} else {
2438 		ip->flags &= ~HAMMER_INODE_REFLUSH;
2439 	}
2440 
2441 	/*
2442 	 * Adjust the flush state.
2443 	 */
2444 	if (ip->flags & HAMMER_INODE_WOULDBLOCK) {
2445 		/*
2446 		 * We were unable to flush out all our records, leave the
2447 		 * inode in a flush state and in the current flush group.
2448 		 * The flush group will be re-run.
2449 		 *
2450 		 * This occurs if the UNDO block gets too full or there is
2451 		 * too much dirty meta-data and allows the flusher to
2452 		 * finalize the UNDO block and then re-flush.
2453 		 */
2454 		ip->flags &= ~HAMMER_INODE_WOULDBLOCK;
2455 		dorel = 0;
2456 	} else {
2457 		/*
2458 		 * Remove from the flush_group
2459 		 */
2460 		RB_REMOVE(hammer_fls_rb_tree, &ip->flush_group->flush_tree, ip);
2461 		ip->flush_group = NULL;
2462 
2463 #if 0
2464 		/*
2465 		 * Clean up the vnode ref and tracking counts.
2466 		 */
2467 		if (ip->flags & HAMMER_INODE_VHELD) {
2468 			ip->flags &= ~HAMMER_INODE_VHELD;
2469 			vrele(ip->vp);
2470 		}
2471 #endif
2472 		--hmp->count_iqueued;
2473 		--hammer_count_iqueued;
2474 
2475 		/*
2476 		 * And adjust the state.
2477 		 */
2478 		if (TAILQ_EMPTY(&ip->target_list) && RB_EMPTY(&ip->rec_tree)) {
2479 			ip->flush_state = HAMMER_FST_IDLE;
2480 			dorel = 1;
2481 		} else {
2482 			ip->flush_state = HAMMER_FST_SETUP;
2483 			dorel = 0;
2484 		}
2485 
2486 		/*
2487 		 * If the frontend is waiting for a flush to complete,
2488 		 * wake it up.
2489 		 */
2490 		if (ip->flags & HAMMER_INODE_FLUSHW) {
2491 			ip->flags &= ~HAMMER_INODE_FLUSHW;
2492 			wakeup(&ip->flags);
2493 		}
2494 
2495 		/*
2496 		 * If the frontend made more changes and requested another
2497 		 * flush, then try to get it running.
2498 		 *
2499 		 * Reflushes are aborted when the inode is errored out.
2500 		 */
2501 		if (ip->flags & HAMMER_INODE_REFLUSH) {
2502 			ip->flags &= ~HAMMER_INODE_REFLUSH;
2503 			if (ip->flags & HAMMER_INODE_RESIGNAL) {
2504 				ip->flags &= ~HAMMER_INODE_RESIGNAL;
2505 				hammer_flush_inode(ip, HAMMER_FLUSH_SIGNAL);
2506 			} else {
2507 				hammer_flush_inode(ip, 0);
2508 			}
2509 		}
2510 	}
2511 
2512 	/*
2513 	 * If we have no parent dependancies we can clear CONN_DOWN
2514 	 */
2515 	if (TAILQ_EMPTY(&ip->target_list))
2516 		ip->flags &= ~HAMMER_INODE_CONN_DOWN;
2517 
2518 	/*
2519 	 * If the inode is now clean drop the space reservation.
2520 	 */
2521 	if ((ip->flags & HAMMER_INODE_MODMASK) == 0 &&
2522 	    (ip->flags & HAMMER_INODE_RSV_INODES)) {
2523 		ip->flags &= ~HAMMER_INODE_RSV_INODES;
2524 		--hmp->rsv_inodes;
2525 	}
2526 
2527 	if (dorel)
2528 		hammer_rel_inode(ip, 0);
2529 }
2530 
2531 /*
2532  * Called from hammer_sync_inode() to synchronize in-memory records
2533  * to the media.
2534  */
2535 static int
2536 hammer_sync_record_callback(hammer_record_t record, void *data)
2537 {
2538 	hammer_cursor_t cursor = data;
2539 	hammer_transaction_t trans = cursor->trans;
2540 	hammer_mount_t hmp = trans->hmp;
2541 	int error;
2542 
2543 	/*
2544 	 * Skip records that do not belong to the current flush.
2545 	 */
2546 	++hammer_stats_record_iterations;
2547 	if (record->flush_state != HAMMER_FST_FLUSH)
2548 		return(0);
2549 
2550 #if 1
2551 	if (record->flush_group != record->ip->flush_group) {
2552 		kprintf("sync_record %p ip %p bad flush group %p %p\n", record, record->ip, record->flush_group ,record->ip->flush_group);
2553 		if (hammer_debug_critical)
2554 			Debugger("blah2");
2555 		return(0);
2556 	}
2557 #endif
2558 	KKASSERT(record->flush_group == record->ip->flush_group);
2559 
2560 	/*
2561 	 * Interlock the record using the BE flag.  Once BE is set the
2562 	 * frontend cannot change the state of FE.
2563 	 *
2564 	 * NOTE: If FE is set prior to us setting BE we still sync the
2565 	 * record out, but the flush completion code converts it to
2566 	 * a delete-on-disk record instead of destroying it.
2567 	 */
2568 	KKASSERT((record->flags & HAMMER_RECF_INTERLOCK_BE) == 0);
2569 	record->flags |= HAMMER_RECF_INTERLOCK_BE;
2570 
2571 	/*
2572 	 * The backend has already disposed of the record.
2573 	 */
2574 	if (record->flags & (HAMMER_RECF_DELETED_BE | HAMMER_RECF_COMMITTED)) {
2575 		error = 0;
2576 		goto done;
2577 	}
2578 
2579 	/*
2580 	 * If the whole inode is being deleting all on-disk records will
2581 	 * be deleted very soon, we can't sync any new records to disk
2582 	 * because they will be deleted in the same transaction they were
2583 	 * created in (delete_tid == create_tid), which will assert.
2584 	 *
2585 	 * XXX There may be a case with RECORD_ADD with DELETED_FE set
2586 	 * that we currently panic on.
2587 	 */
2588 	if (record->ip->sync_flags & HAMMER_INODE_DELETING) {
2589 		switch(record->type) {
2590 		case HAMMER_MEM_RECORD_DATA:
2591 			/*
2592 			 * We don't have to do anything, if the record was
2593 			 * committed the space will have been accounted for
2594 			 * in the blockmap.
2595 			 */
2596 			/* fall through */
2597 		case HAMMER_MEM_RECORD_GENERAL:
2598 			/*
2599 			 * Set deleted-by-backend flag.  Do not set the
2600 			 * backend committed flag, because we are throwing
2601 			 * the record away.
2602 			 */
2603 			record->flags |= HAMMER_RECF_DELETED_BE;
2604 			++record->ip->rec_generation;
2605 			error = 0;
2606 			goto done;
2607 		case HAMMER_MEM_RECORD_ADD:
2608 			panic("hammer_sync_record_callback: illegal add "
2609 			      "during inode deletion record %p", record);
2610 			break; /* NOT REACHED */
2611 		case HAMMER_MEM_RECORD_INODE:
2612 			panic("hammer_sync_record_callback: attempt to "
2613 			      "sync inode record %p?", record);
2614 			break; /* NOT REACHED */
2615 		case HAMMER_MEM_RECORD_DEL:
2616 			/*
2617 			 * Follow through and issue the on-disk deletion
2618 			 */
2619 			break;
2620 		}
2621 	}
2622 
2623 	/*
2624 	 * If DELETED_FE is set special handling is needed for directory
2625 	 * entries.  Dependant pieces related to the directory entry may
2626 	 * have already been synced to disk.  If this occurs we have to
2627 	 * sync the directory entry and then change the in-memory record
2628 	 * from an ADD to a DELETE to cover the fact that it's been
2629 	 * deleted by the frontend.
2630 	 *
2631 	 * A directory delete covering record (MEM_RECORD_DEL) can never
2632 	 * be deleted by the frontend.
2633 	 *
2634 	 * Any other record type (aka DATA) can be deleted by the frontend.
2635 	 * XXX At the moment the flusher must skip it because there may
2636 	 * be another data record in the flush group for the same block,
2637 	 * meaning that some frontend data changes can leak into the backend's
2638 	 * synchronization point.
2639 	 */
2640 	if (record->flags & HAMMER_RECF_DELETED_FE) {
2641 		if (record->type == HAMMER_MEM_RECORD_ADD) {
2642 			/*
2643 			 * Convert a front-end deleted directory-add to
2644 			 * a directory-delete entry later.
2645 			 */
2646 			record->flags |= HAMMER_RECF_CONVERT_DELETE;
2647 		} else {
2648 			/*
2649 			 * Dispose of the record (race case).  Mark as
2650 			 * deleted by backend (and not committed).
2651 			 */
2652 			KKASSERT(record->type != HAMMER_MEM_RECORD_DEL);
2653 			record->flags |= HAMMER_RECF_DELETED_BE;
2654 			++record->ip->rec_generation;
2655 			error = 0;
2656 			goto done;
2657 		}
2658 	}
2659 
2660 	/*
2661 	 * Assign the create_tid for new records.  Deletions already
2662 	 * have the record's entire key properly set up.
2663 	 */
2664 	if (record->type != HAMMER_MEM_RECORD_DEL) {
2665 		record->leaf.base.create_tid = trans->tid;
2666 		record->leaf.create_ts = trans->time32;
2667 	}
2668 
2669 	/*
2670 	 * This actually moves the record to the on-media B-Tree.  We
2671 	 * must also generate REDO_TERM entries in the UNDO/REDO FIFO
2672 	 * indicating that the related REDO_WRITE(s) have been committed.
2673 	 *
2674 	 * During recovery any REDO_TERM's within the nominal recovery span
2675 	 * are ignored since the related meta-data is being undone, causing
2676 	 * any matching REDO_WRITEs to execute.  The REDO_TERMs outside
2677 	 * the nominal recovery span will match against REDO_WRITEs and
2678 	 * prevent them from being executed (because the meta-data has
2679 	 * already been synchronized).
2680 	 */
2681 	if (record->flags & HAMMER_RECF_REDO) {
2682 		KKASSERT(record->type == HAMMER_MEM_RECORD_DATA);
2683 		hammer_generate_redo(trans, record->ip,
2684 				     record->leaf.base.key -
2685 					 record->leaf.data_len,
2686 				     HAMMER_REDO_TERM_WRITE,
2687 				     NULL,
2688 				     record->leaf.data_len);
2689 	}
2690 	for (;;) {
2691 		error = hammer_ip_sync_record_cursor(cursor, record);
2692 		if (error != EDEADLK)
2693 			break;
2694 		hammer_done_cursor(cursor);
2695 		error = hammer_init_cursor(trans, cursor, &record->ip->cache[0],
2696 					   record->ip);
2697 		if (error)
2698 			break;
2699 	}
2700 	record->flags &= ~HAMMER_RECF_CONVERT_DELETE;
2701 
2702 	if (error)
2703 		error = -error;
2704 done:
2705 	hammer_flush_record_done(record, error);
2706 
2707 	/*
2708 	 * Do partial finalization if we have built up too many dirty
2709 	 * buffers.  Otherwise a buffer cache deadlock can occur when
2710 	 * doing things like creating tens of thousands of tiny files.
2711 	 *
2712 	 * We must release our cursor lock to avoid a 3-way deadlock
2713 	 * due to the exclusive sync lock the finalizer must get.
2714 	 *
2715 	 * WARNING: See warnings in hammer_unlock_cursor() function.
2716 	 */
2717         if (hammer_flusher_meta_limit(hmp)) {
2718 		hammer_unlock_cursor(cursor);
2719                 hammer_flusher_finalize(trans, 0);
2720 		hammer_lock_cursor(cursor);
2721 	}
2722 
2723 	return(error);
2724 }
2725 
2726 /*
2727  * Backend function called by the flusher to sync an inode to media.
2728  */
2729 int
2730 hammer_sync_inode(hammer_transaction_t trans, hammer_inode_t ip)
2731 {
2732 	struct hammer_cursor cursor;
2733 	hammer_node_t tmp_node;
2734 	hammer_record_t depend;
2735 	hammer_record_t next;
2736 	int error, tmp_error;
2737 	u_int64_t nlinks;
2738 
2739 	if ((ip->sync_flags & HAMMER_INODE_MODMASK) == 0)
2740 		return(0);
2741 
2742 	error = hammer_init_cursor(trans, &cursor, &ip->cache[1], ip);
2743 	if (error)
2744 		goto done;
2745 
2746 	/*
2747 	 * Any directory records referencing this inode which are not in
2748 	 * our current flush group must adjust our nlink count for the
2749 	 * purposes of synchronizating to disk.
2750 	 *
2751 	 * Records which are in our flush group can be unlinked from our
2752 	 * inode now, potentially allowing the inode to be physically
2753 	 * deleted.
2754 	 *
2755 	 * This cannot block.
2756 	 */
2757 	nlinks = ip->ino_data.nlinks;
2758 	next = TAILQ_FIRST(&ip->target_list);
2759 	while ((depend = next) != NULL) {
2760 		next = TAILQ_NEXT(depend, target_entry);
2761 		if (depend->flush_state == HAMMER_FST_FLUSH &&
2762 		    depend->flush_group == ip->flush_group) {
2763 			/*
2764 			 * If this is an ADD that was deleted by the frontend
2765 			 * the frontend nlinks count will have already been
2766 			 * decremented, but the backend is going to sync its
2767 			 * directory entry and must account for it.  The
2768 			 * record will be converted to a delete-on-disk when
2769 			 * it gets synced.
2770 			 *
2771 			 * If the ADD was not deleted by the frontend we
2772 			 * can remove the dependancy from our target_list.
2773 			 */
2774 			if (depend->flags & HAMMER_RECF_DELETED_FE) {
2775 				++nlinks;
2776 			} else {
2777 				TAILQ_REMOVE(&ip->target_list, depend,
2778 					     target_entry);
2779 				depend->target_ip = NULL;
2780 			}
2781 		} else if ((depend->flags & HAMMER_RECF_DELETED_FE) == 0) {
2782 			/*
2783 			 * Not part of our flush group and not deleted by
2784 			 * the front-end, adjust the link count synced to
2785 			 * the media (undo what the frontend did when it
2786 			 * queued the record).
2787 			 */
2788 			KKASSERT((depend->flags & HAMMER_RECF_DELETED_BE) == 0);
2789 			switch(depend->type) {
2790 			case HAMMER_MEM_RECORD_ADD:
2791 				--nlinks;
2792 				break;
2793 			case HAMMER_MEM_RECORD_DEL:
2794 				++nlinks;
2795 				break;
2796 			default:
2797 				break;
2798 			}
2799 		}
2800 	}
2801 
2802 	/*
2803 	 * Set dirty if we had to modify the link count.
2804 	 */
2805 	if (ip->sync_ino_data.nlinks != nlinks) {
2806 		KKASSERT((int64_t)nlinks >= 0);
2807 		ip->sync_ino_data.nlinks = nlinks;
2808 		ip->sync_flags |= HAMMER_INODE_DDIRTY;
2809 	}
2810 
2811 	/*
2812 	 * If there is a trunction queued destroy any data past the (aligned)
2813 	 * truncation point.  Userland will have dealt with the buffer
2814 	 * containing the truncation point for us.
2815 	 *
2816 	 * We don't flush pending frontend data buffers until after we've
2817 	 * dealt with the truncation.
2818 	 */
2819 	if (ip->sync_flags & HAMMER_INODE_TRUNCATED) {
2820 		/*
2821 		 * Interlock trunc_off.  The VOP front-end may continue to
2822 		 * make adjustments to it while we are blocked.
2823 		 */
2824 		off_t trunc_off;
2825 		off_t aligned_trunc_off;
2826 		int blkmask;
2827 
2828 		trunc_off = ip->sync_trunc_off;
2829 		blkmask = hammer_blocksize(trunc_off) - 1;
2830 		aligned_trunc_off = (trunc_off + blkmask) & ~(int64_t)blkmask;
2831 
2832 		/*
2833 		 * Delete any whole blocks on-media.  The front-end has
2834 		 * already cleaned out any partial block and made it
2835 		 * pending.  The front-end may have updated trunc_off
2836 		 * while we were blocked so we only use sync_trunc_off.
2837 		 *
2838 		 * This operation can blow out the buffer cache, EWOULDBLOCK
2839 		 * means we were unable to complete the deletion.  The
2840 		 * deletion will update sync_trunc_off in that case.
2841 		 */
2842 		error = hammer_ip_delete_range(&cursor, ip,
2843 						aligned_trunc_off,
2844 						0x7FFFFFFFFFFFFFFFLL, 2);
2845 		if (error == EWOULDBLOCK) {
2846 			ip->flags |= HAMMER_INODE_WOULDBLOCK;
2847 			error = 0;
2848 			goto defer_buffer_flush;
2849 		}
2850 
2851 		if (error)
2852 			goto done;
2853 
2854 		/*
2855 		 * Generate a REDO_TERM_TRUNC entry in the UNDO/REDO FIFO.
2856 		 *
2857 		 * XXX we do this even if we did not previously generate
2858 		 * a REDO_TRUNC record.  This operation may enclosed the
2859 		 * range for multiple prior truncation entries in the REDO
2860 		 * log.
2861 		 */
2862 		if (trans->hmp->version >= HAMMER_VOL_VERSION_FOUR &&
2863 		    (ip->flags & HAMMER_INODE_RDIRTY)) {
2864 			hammer_generate_redo(trans, ip, aligned_trunc_off,
2865 					     HAMMER_REDO_TERM_TRUNC,
2866 					     NULL, 0);
2867 		}
2868 
2869 		/*
2870 		 * Clear the truncation flag on the backend after we have
2871 		 * completed the deletions.  Backend data is now good again
2872 		 * (including new records we are about to sync, below).
2873 		 *
2874 		 * Leave sync_trunc_off intact.  As we write additional
2875 		 * records the backend will update sync_trunc_off.  This
2876 		 * tells the backend whether it can skip the overwrite
2877 		 * test.  This should work properly even when the backend
2878 		 * writes full blocks where the truncation point straddles
2879 		 * the block because the comparison is against the base
2880 		 * offset of the record.
2881 		 */
2882 		ip->sync_flags &= ~HAMMER_INODE_TRUNCATED;
2883 		/* ip->sync_trunc_off = 0x7FFFFFFFFFFFFFFFLL; */
2884 	} else {
2885 		error = 0;
2886 	}
2887 
2888 	/*
2889 	 * Now sync related records.  These will typically be directory
2890 	 * entries, records tracking direct-writes, or delete-on-disk records.
2891 	 */
2892 	if (error == 0) {
2893 		tmp_error = RB_SCAN(hammer_rec_rb_tree, &ip->rec_tree, NULL,
2894 				    hammer_sync_record_callback, &cursor);
2895 		if (tmp_error < 0)
2896 			tmp_error = -error;
2897 		if (tmp_error)
2898 			error = tmp_error;
2899 	}
2900 	hammer_cache_node(&ip->cache[1], cursor.node);
2901 
2902 	/*
2903 	 * Re-seek for inode update, assuming our cache hasn't been ripped
2904 	 * out from under us.
2905 	 */
2906 	if (error == 0) {
2907 		tmp_node = hammer_ref_node_safe(trans, &ip->cache[0], &error);
2908 		if (tmp_node) {
2909 			hammer_cursor_downgrade(&cursor);
2910 			hammer_lock_sh(&tmp_node->lock);
2911 			if ((tmp_node->flags & HAMMER_NODE_DELETED) == 0)
2912 				hammer_cursor_seek(&cursor, tmp_node, 0);
2913 			hammer_unlock(&tmp_node->lock);
2914 			hammer_rel_node(tmp_node);
2915 		}
2916 		error = 0;
2917 	}
2918 
2919 	/*
2920 	 * If we are deleting the inode the frontend had better not have
2921 	 * any active references on elements making up the inode.
2922 	 *
2923 	 * The call to hammer_ip_delete_clean() cleans up auxillary records
2924 	 * but not DB or DATA records.  Those must have already been deleted
2925 	 * by the normal truncation mechanic.
2926 	 */
2927 	if (error == 0 && ip->sync_ino_data.nlinks == 0 &&
2928 		RB_EMPTY(&ip->rec_tree)  &&
2929 	    (ip->sync_flags & HAMMER_INODE_DELETING) &&
2930 	    (ip->flags & HAMMER_INODE_DELETED) == 0) {
2931 		int count1 = 0;
2932 
2933 		error = hammer_ip_delete_clean(&cursor, ip, &count1);
2934 		if (error == 0) {
2935 			ip->flags |= HAMMER_INODE_DELETED;
2936 			ip->sync_flags &= ~HAMMER_INODE_DELETING;
2937 			ip->sync_flags &= ~HAMMER_INODE_TRUNCATED;
2938 			KKASSERT(RB_EMPTY(&ip->rec_tree));
2939 
2940 			/*
2941 			 * Set delete_tid in both the frontend and backend
2942 			 * copy of the inode record.  The DELETED flag handles
2943 			 * this, do not set DDIRTY.
2944 			 */
2945 			ip->ino_leaf.base.delete_tid = trans->tid;
2946 			ip->sync_ino_leaf.base.delete_tid = trans->tid;
2947 			ip->ino_leaf.delete_ts = trans->time32;
2948 			ip->sync_ino_leaf.delete_ts = trans->time32;
2949 
2950 
2951 			/*
2952 			 * Adjust the inode count in the volume header
2953 			 */
2954 			hammer_sync_lock_sh(trans);
2955 			if (ip->flags & HAMMER_INODE_ONDISK) {
2956 				hammer_modify_volume_field(trans,
2957 							   trans->rootvol,
2958 							   vol0_stat_inodes);
2959 				--ip->hmp->rootvol->ondisk->vol0_stat_inodes;
2960 				hammer_modify_volume_done(trans->rootvol);
2961 			}
2962 			hammer_sync_unlock(trans);
2963 		}
2964 	}
2965 
2966 	if (error)
2967 		goto done;
2968 	ip->sync_flags &= ~HAMMER_INODE_BUFS;
2969 
2970 defer_buffer_flush:
2971 	/*
2972 	 * Now update the inode's on-disk inode-data and/or on-disk record.
2973 	 * DELETED and ONDISK are managed only in ip->flags.
2974 	 *
2975 	 * In the case of a defered buffer flush we still update the on-disk
2976 	 * inode to satisfy visibility requirements if there happen to be
2977 	 * directory dependancies.
2978 	 */
2979 	switch(ip->flags & (HAMMER_INODE_DELETED | HAMMER_INODE_ONDISK)) {
2980 	case HAMMER_INODE_DELETED|HAMMER_INODE_ONDISK:
2981 		/*
2982 		 * If deleted and on-disk, don't set any additional flags.
2983 		 * the delete flag takes care of things.
2984 		 *
2985 		 * Clear flags which may have been set by the frontend.
2986 		 */
2987 		ip->sync_flags &= ~(HAMMER_INODE_DDIRTY | HAMMER_INODE_XDIRTY |
2988 				    HAMMER_INODE_SDIRTY |
2989 				    HAMMER_INODE_ATIME | HAMMER_INODE_MTIME |
2990 				    HAMMER_INODE_DELETING);
2991 		break;
2992 	case HAMMER_INODE_DELETED:
2993 		/*
2994 		 * Take care of the case where a deleted inode was never
2995 		 * flushed to the disk in the first place.
2996 		 *
2997 		 * Clear flags which may have been set by the frontend.
2998 		 */
2999 		ip->sync_flags &= ~(HAMMER_INODE_DDIRTY | HAMMER_INODE_XDIRTY |
3000 				    HAMMER_INODE_SDIRTY |
3001 				    HAMMER_INODE_ATIME | HAMMER_INODE_MTIME |
3002 				    HAMMER_INODE_DELETING);
3003 		while (RB_ROOT(&ip->rec_tree)) {
3004 			hammer_record_t record = RB_ROOT(&ip->rec_tree);
3005 			hammer_ref(&record->lock);
3006 			KKASSERT(hammer_oneref(&record->lock));
3007 			record->flags |= HAMMER_RECF_DELETED_BE;
3008 			++record->ip->rec_generation;
3009 			hammer_rel_mem_record(record);
3010 		}
3011 		break;
3012 	case HAMMER_INODE_ONDISK:
3013 		/*
3014 		 * If already on-disk, do not set any additional flags.
3015 		 */
3016 		break;
3017 	default:
3018 		/*
3019 		 * If not on-disk and not deleted, set DDIRTY to force
3020 		 * an initial record to be written.
3021 		 *
3022 		 * Also set the create_tid in both the frontend and backend
3023 		 * copy of the inode record.
3024 		 */
3025 		ip->ino_leaf.base.create_tid = trans->tid;
3026 		ip->ino_leaf.create_ts = trans->time32;
3027 		ip->sync_ino_leaf.base.create_tid = trans->tid;
3028 		ip->sync_ino_leaf.create_ts = trans->time32;
3029 		ip->sync_flags |= HAMMER_INODE_DDIRTY;
3030 		break;
3031 	}
3032 
3033 	/*
3034 	 * If DDIRTY or SDIRTY is set, write out a new record.
3035 	 * If the inode is already on-disk the old record is marked as
3036 	 * deleted.
3037 	 *
3038 	 * If DELETED is set hammer_update_inode() will delete the existing
3039 	 * record without writing out a new one.
3040 	 *
3041 	 * If *ONLY* the ITIMES flag is set we can update the record in-place.
3042 	 */
3043 	if (ip->flags & HAMMER_INODE_DELETED) {
3044 		error = hammer_update_inode(&cursor, ip);
3045 	} else
3046 	if (!(ip->sync_flags & (HAMMER_INODE_DDIRTY | HAMMER_INODE_SDIRTY)) &&
3047 	    (ip->sync_flags & (HAMMER_INODE_ATIME | HAMMER_INODE_MTIME))) {
3048 		error = hammer_update_itimes(&cursor, ip);
3049 	} else
3050 	if (ip->sync_flags & (HAMMER_INODE_DDIRTY | HAMMER_INODE_SDIRTY |
3051 			      HAMMER_INODE_ATIME | HAMMER_INODE_MTIME)) {
3052 		error = hammer_update_inode(&cursor, ip);
3053 	}
3054 done:
3055 	if (error) {
3056 		hammer_critical_error(ip->hmp, ip, error,
3057 				      "while syncing inode");
3058 	}
3059 	hammer_done_cursor(&cursor);
3060 	return(error);
3061 }
3062 
3063 /*
3064  * This routine is called when the OS is no longer actively referencing
3065  * the inode (but might still be keeping it cached), or when releasing
3066  * the last reference to an inode.
3067  *
3068  * At this point if the inode's nlinks count is zero we want to destroy
3069  * it, which may mean destroying it on-media too.
3070  */
3071 void
3072 hammer_inode_unloadable_check(hammer_inode_t ip, int getvp)
3073 {
3074 	struct vnode *vp;
3075 
3076 	/*
3077 	 * Set the DELETING flag when the link count drops to 0 and the
3078 	 * OS no longer has any opens on the inode.
3079 	 *
3080 	 * The backend will clear DELETING (a mod flag) and set DELETED
3081 	 * (a state flag) when it is actually able to perform the
3082 	 * operation.
3083 	 *
3084 	 * Don't reflag the deletion if the flusher is currently syncing
3085 	 * one that was already flagged.  A previously set DELETING flag
3086 	 * may bounce around flags and sync_flags until the operation is
3087 	 * completely done.
3088 	 *
3089 	 * Do not attempt to modify a snapshot inode (one set to read-only).
3090 	 */
3091 	if (ip->ino_data.nlinks == 0 &&
3092 	    ((ip->flags | ip->sync_flags) & (HAMMER_INODE_RO|HAMMER_INODE_DELETING|HAMMER_INODE_DELETED)) == 0) {
3093 		ip->flags |= HAMMER_INODE_DELETING;
3094 		ip->flags |= HAMMER_INODE_TRUNCATED;
3095 		ip->trunc_off = 0;
3096 		vp = NULL;
3097 		if (getvp) {
3098 			if (hammer_get_vnode(ip, &vp) != 0)
3099 				return;
3100 		}
3101 
3102 		/*
3103 		 * Final cleanup
3104 		 */
3105 		if (ip->vp)
3106 			nvtruncbuf(ip->vp, 0, HAMMER_BUFSIZE, 0);
3107 		if (getvp)
3108 			vput(vp);
3109 	}
3110 }
3111 
3112 /*
3113  * After potentially resolving a dependancy the inode is tested
3114  * to determine whether it needs to be reflushed.
3115  */
3116 void
3117 hammer_test_inode(hammer_inode_t ip)
3118 {
3119 	if (ip->flags & HAMMER_INODE_REFLUSH) {
3120 		ip->flags &= ~HAMMER_INODE_REFLUSH;
3121 		hammer_ref(&ip->lock);
3122 		if (ip->flags & HAMMER_INODE_RESIGNAL) {
3123 			ip->flags &= ~HAMMER_INODE_RESIGNAL;
3124 			hammer_flush_inode(ip, HAMMER_FLUSH_SIGNAL);
3125 		} else {
3126 			hammer_flush_inode(ip, 0);
3127 		}
3128 		hammer_rel_inode(ip, 0);
3129 	}
3130 }
3131 
3132 /*
3133  * Clear the RECLAIM flag on an inode.  This occurs when the inode is
3134  * reassociated with a vp or just before it gets freed.
3135  *
3136  * Pipeline wakeups to threads blocked due to an excessive number of
3137  * detached inodes.  This typically occurs when atime updates accumulate
3138  * while scanning a directory tree.
3139  */
3140 static void
3141 hammer_inode_wakereclaims(hammer_inode_t ip)
3142 {
3143 	struct hammer_reclaim *reclaim;
3144 	hammer_mount_t hmp = ip->hmp;
3145 
3146 	if ((ip->flags & HAMMER_INODE_RECLAIM) == 0)
3147 		return;
3148 
3149 	--hammer_count_reclaiming;
3150 	--hmp->inode_reclaims;
3151 	ip->flags &= ~HAMMER_INODE_RECLAIM;
3152 
3153 	while ((reclaim = TAILQ_FIRST(&hmp->reclaim_list)) != NULL) {
3154 		if (reclaim->count > 0 && --reclaim->count == 0) {
3155 			TAILQ_REMOVE(&hmp->reclaim_list, reclaim, entry);
3156 			wakeup(reclaim);
3157 		}
3158 		if (hmp->inode_reclaims > hammer_limit_reclaim / 2)
3159 			break;
3160 	}
3161 }
3162 
3163 /*
3164  * Setup our reclaim pipeline.  We only let so many detached (and dirty)
3165  * inodes build up before we start blocking.  This routine is called
3166  * if a new inode is created or an inode is loaded from media.
3167  *
3168  * When we block we don't care *which* inode has finished reclaiming,
3169  * as lone as one does.
3170  */
3171 void
3172 hammer_inode_waitreclaims(hammer_transaction_t trans)
3173 {
3174 	hammer_mount_t hmp = trans->hmp;
3175 	struct hammer_reclaim reclaim;
3176 
3177 	/*
3178 	 * Track inode load
3179 	 */
3180 	if (curthread->td_proc) {
3181 		struct hammer_inostats *stats;
3182 		int lower_limit;
3183 
3184 		stats = hammer_inode_inostats(hmp, curthread->td_proc->p_pid);
3185 		++stats->count;
3186 
3187 		if (stats->count > hammer_limit_reclaim / 2)
3188 			stats->count = hammer_limit_reclaim / 2;
3189 		lower_limit = hammer_limit_reclaim - stats->count;
3190 		if (hammer_debug_general & 0x10000)
3191 			kprintf("pid %5d limit %d\n", (int)curthread->td_proc->p_pid, lower_limit);
3192 
3193 		if (hmp->inode_reclaims < lower_limit)
3194 			return;
3195 	} else {
3196 		/*
3197 		 * Default mode
3198 		 */
3199 		if (hmp->inode_reclaims < hammer_limit_reclaim)
3200 			return;
3201 	}
3202 	reclaim.count = 1;
3203 	TAILQ_INSERT_TAIL(&hmp->reclaim_list, &reclaim, entry);
3204 	tsleep(&reclaim, 0, "hmrrcm", hz);
3205 	if (reclaim.count > 0)
3206 		TAILQ_REMOVE(&hmp->reclaim_list, &reclaim, entry);
3207 }
3208 
3209 /*
3210  * Keep track of reclaim statistics on a per-pid basis using a loose
3211  * 4-way set associative hash table.  Collisions inherit the count of
3212  * the previous entry.
3213  *
3214  * NOTE: We want to be careful here to limit the chain size.  If the chain
3215  *	 size is too large a pid will spread its stats out over too many
3216  *	 entries under certain types of heavy filesystem activity and
3217  *	 wind up not delaying long enough.
3218  */
3219 static
3220 struct hammer_inostats *
3221 hammer_inode_inostats(hammer_mount_t hmp, pid_t pid)
3222 {
3223 	struct hammer_inostats *stats;
3224 	int delta;
3225 	int chain;
3226 	static volatile int iterator;	/* we don't care about MP races */
3227 
3228 	/*
3229 	 * Chain up to 4 times to find our entry.
3230 	 */
3231 	for (chain = 0; chain < 4; ++chain) {
3232 		stats = &hmp->inostats[(pid + chain) & HAMMER_INOSTATS_HMASK];
3233 		if (stats->pid == pid)
3234 			break;
3235 	}
3236 
3237 	/*
3238 	 * Replace one of the four chaining entries with our new entry.
3239 	 */
3240 	if (chain == 4) {
3241 		stats = &hmp->inostats[(pid + (iterator++ & 3)) &
3242 				       HAMMER_INOSTATS_HMASK];
3243 		stats->pid = pid;
3244 	}
3245 
3246 	/*
3247 	 * Decay the entry
3248 	 */
3249 	if (stats->count && stats->ltick != ticks) {
3250 		delta = ticks - stats->ltick;
3251 		stats->ltick = ticks;
3252 		if (delta <= 0 || delta > hz * 60)
3253 			stats->count = 0;
3254 		else
3255 			stats->count = stats->count * hz / (hz + delta);
3256 	}
3257 	if (hammer_debug_general & 0x10000)
3258 		kprintf("pid %5d stats %d\n", (int)pid, stats->count);
3259 	return (stats);
3260 }
3261 
3262 #if 0
3263 
3264 /*
3265  * XXX not used, doesn't work very well due to the large batching nature
3266  * of flushes.
3267  *
3268  * A larger then normal backlog of inodes is sitting in the flusher,
3269  * enforce a general slowdown to let it catch up.  This routine is only
3270  * called on completion of a non-flusher-related transaction which
3271  * performed B-Tree node I/O.
3272  *
3273  * It is possible for the flusher to stall in a continuous load.
3274  * blogbench -i1000 -o seems to do a good job generating this sort of load.
3275  * If the flusher is unable to catch up the inode count can bloat until
3276  * we run out of kvm.
3277  *
3278  * This is a bit of a hack.
3279  */
3280 void
3281 hammer_inode_waithard(hammer_mount_t hmp)
3282 {
3283 	/*
3284 	 * Hysteresis.
3285 	 */
3286 	if (hmp->flags & HAMMER_MOUNT_FLUSH_RECOVERY) {
3287 		if (hmp->inode_reclaims < hammer_limit_reclaim / 2 &&
3288 		    hmp->count_iqueued < hmp->count_inodes / 20) {
3289 			hmp->flags &= ~HAMMER_MOUNT_FLUSH_RECOVERY;
3290 			return;
3291 		}
3292 	} else {
3293 		if (hmp->inode_reclaims < hammer_limit_reclaim ||
3294 		    hmp->count_iqueued < hmp->count_inodes / 10) {
3295 			return;
3296 		}
3297 		hmp->flags |= HAMMER_MOUNT_FLUSH_RECOVERY;
3298 	}
3299 
3300 	/*
3301 	 * Block for one flush cycle.
3302 	 */
3303 	hammer_flusher_wait_next(hmp);
3304 }
3305 
3306 #endif
3307