xref: /dragonfly/sys/vfs/hammer/hammer_inode.c (revision 73610d44)
1 /*
2  * Copyright (c) 2007-2008 The DragonFly Project.  All rights reserved.
3  *
4  * This code is derived from software contributed to The DragonFly Project
5  * by Matthew Dillon <dillon@backplane.com>
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  *
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in
15  *    the documentation and/or other materials provided with the
16  *    distribution.
17  * 3. Neither the name of The DragonFly Project nor the names of its
18  *    contributors may be used to endorse or promote products derived
19  *    from this software without specific, prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 #include <vm/vm_page2.h>
36 
37 #include "hammer.h"
38 
39 static int	hammer_unload_inode(struct hammer_inode *ip);
40 static void	hammer_free_inode(hammer_inode_t ip);
41 static void	hammer_flush_inode_core(hammer_inode_t ip,
42 					hammer_flush_group_t flg, int flags);
43 static int	hammer_setup_child_callback(hammer_record_t rec, void *data);
44 #if 0
45 static int	hammer_syncgrp_child_callback(hammer_record_t rec, void *data);
46 #endif
47 static int	hammer_setup_parent_inodes(hammer_inode_t ip, int depth,
48 					hammer_flush_group_t flg);
49 static int	hammer_setup_parent_inodes_helper(hammer_record_t record,
50 					int depth, hammer_flush_group_t flg);
51 static void	hammer_inode_wakereclaims(hammer_inode_t ip);
52 static struct hammer_inostats *hammer_inode_inostats(hammer_mount_t hmp,
53 					pid_t pid);
54 
55 #ifdef DEBUG_TRUNCATE
56 extern struct hammer_inode *HammerTruncIp;
57 #endif
58 
59 struct krate hammer_gen_krate = { 1 };
60 
61 /*
62  * RB-Tree support for inode structures
63  */
64 int
65 hammer_ino_rb_compare(hammer_inode_t ip1, hammer_inode_t ip2)
66 {
67 	if (ip1->obj_localization < ip2->obj_localization)
68 		return(-1);
69 	if (ip1->obj_localization > ip2->obj_localization)
70 		return(1);
71 	if (ip1->obj_id < ip2->obj_id)
72 		return(-1);
73 	if (ip1->obj_id > ip2->obj_id)
74 		return(1);
75 	if (ip1->obj_asof < ip2->obj_asof)
76 		return(-1);
77 	if (ip1->obj_asof > ip2->obj_asof)
78 		return(1);
79 	return(0);
80 }
81 
82 int
83 hammer_redo_rb_compare(hammer_inode_t ip1, hammer_inode_t ip2)
84 {
85 	if (ip1->redo_fifo_start < ip2->redo_fifo_start)
86 		return(-1);
87 	if (ip1->redo_fifo_start > ip2->redo_fifo_start)
88 		return(1);
89 	return(0);
90 }
91 
92 /*
93  * RB-Tree support for inode structures / special LOOKUP_INFO
94  */
95 static int
96 hammer_inode_info_cmp(hammer_inode_info_t info, hammer_inode_t ip)
97 {
98 	if (info->obj_localization < ip->obj_localization)
99 		return(-1);
100 	if (info->obj_localization > ip->obj_localization)
101 		return(1);
102 	if (info->obj_id < ip->obj_id)
103 		return(-1);
104 	if (info->obj_id > ip->obj_id)
105 		return(1);
106 	if (info->obj_asof < ip->obj_asof)
107 		return(-1);
108 	if (info->obj_asof > ip->obj_asof)
109 		return(1);
110 	return(0);
111 }
112 
113 /*
114  * Used by hammer_scan_inode_snapshots() to locate all of an object's
115  * snapshots.  Note that the asof field is not tested, which we can get
116  * away with because it is the lowest-priority field.
117  */
118 static int
119 hammer_inode_info_cmp_all_history(hammer_inode_t ip, void *data)
120 {
121 	hammer_inode_info_t info = data;
122 
123 	if (ip->obj_localization > info->obj_localization)
124 		return(1);
125 	if (ip->obj_localization < info->obj_localization)
126 		return(-1);
127 	if (ip->obj_id > info->obj_id)
128 		return(1);
129 	if (ip->obj_id < info->obj_id)
130 		return(-1);
131 	return(0);
132 }
133 
134 /*
135  * Used by hammer_unload_pseudofs() to locate all inodes associated with
136  * a particular PFS.
137  */
138 static int
139 hammer_inode_pfs_cmp(hammer_inode_t ip, void *data)
140 {
141 	u_int32_t localization = *(u_int32_t *)data;
142 	if (ip->obj_localization > localization)
143 		return(1);
144 	if (ip->obj_localization < localization)
145 		return(-1);
146 	return(0);
147 }
148 
149 /*
150  * RB-Tree support for pseudofs structures
151  */
152 static int
153 hammer_pfs_rb_compare(hammer_pseudofs_inmem_t p1, hammer_pseudofs_inmem_t p2)
154 {
155 	if (p1->localization < p2->localization)
156 		return(-1);
157 	if (p1->localization > p2->localization)
158 		return(1);
159 	return(0);
160 }
161 
162 
163 RB_GENERATE(hammer_ino_rb_tree, hammer_inode, rb_node, hammer_ino_rb_compare);
164 RB_GENERATE_XLOOKUP(hammer_ino_rb_tree, INFO, hammer_inode, rb_node,
165 		hammer_inode_info_cmp, hammer_inode_info_t);
166 RB_GENERATE2(hammer_pfs_rb_tree, hammer_pseudofs_inmem, rb_node,
167              hammer_pfs_rb_compare, u_int32_t, localization);
168 
169 /*
170  * The kernel is not actively referencing this vnode but is still holding
171  * it cached.
172  *
173  * This is called from the frontend.
174  *
175  * MPALMOSTSAFE
176  */
177 int
178 hammer_vop_inactive(struct vop_inactive_args *ap)
179 {
180 	struct hammer_inode *ip = VTOI(ap->a_vp);
181 	hammer_mount_t hmp;
182 
183 	/*
184 	 * Degenerate case
185 	 */
186 	if (ip == NULL) {
187 		vrecycle(ap->a_vp);
188 		return(0);
189 	}
190 
191 	/*
192 	 * If the inode no longer has visibility in the filesystem try to
193 	 * recycle it immediately, even if the inode is dirty.  Recycling
194 	 * it quickly allows the system to reclaim buffer cache and VM
195 	 * resources which can matter a lot in a heavily loaded system.
196 	 *
197 	 * This can deadlock in vfsync() if we aren't careful.
198 	 *
199 	 * Do not queue the inode to the flusher if we still have visibility,
200 	 * otherwise namespace calls such as chmod will unnecessarily generate
201 	 * multiple inode updates.
202 	 */
203 	if (ip->ino_data.nlinks == 0) {
204 		hmp = ip->hmp;
205 		lwkt_gettoken(&hmp->fs_token);
206 		hammer_inode_unloadable_check(ip, 0);
207 		if (ip->flags & HAMMER_INODE_MODMASK)
208 			hammer_flush_inode(ip, 0);
209 		lwkt_reltoken(&hmp->fs_token);
210 		vrecycle(ap->a_vp);
211 	}
212 	return(0);
213 }
214 
215 /*
216  * Release the vnode association.  This is typically (but not always)
217  * the last reference on the inode.
218  *
219  * Once the association is lost we are on our own with regards to
220  * flushing the inode.
221  *
222  * We must interlock ip->vp so hammer_get_vnode() can avoid races.
223  */
224 int
225 hammer_vop_reclaim(struct vop_reclaim_args *ap)
226 {
227 	struct hammer_inode *ip;
228 	hammer_mount_t hmp;
229 	struct vnode *vp;
230 
231 	vp = ap->a_vp;
232 
233 	if ((ip = vp->v_data) != NULL) {
234 		hmp = ip->hmp;
235 		lwkt_gettoken(&hmp->fs_token);
236 		hammer_lock_ex(&ip->lock);
237 		vp->v_data = NULL;
238 		ip->vp = NULL;
239 
240 		if ((ip->flags & HAMMER_INODE_RECLAIM) == 0) {
241 			++hammer_count_reclaims;
242 			++hmp->count_reclaims;
243 			ip->flags |= HAMMER_INODE_RECLAIM;
244 		}
245 		hammer_unlock(&ip->lock);
246 		vclrisdirty(vp);
247 		hammer_rel_inode(ip, 1);
248 		lwkt_reltoken(&hmp->fs_token);
249 	}
250 	return(0);
251 }
252 
253 /*
254  * Inform the kernel that the inode is dirty.  This will be checked
255  * by vn_unlock().
256  *
257  * Theoretically in order to reclaim a vnode the hammer_vop_reclaim()
258  * must be called which will interlock against our inode lock, so
259  * if VRECLAIMED is not set vp->v_mount (as used by vsetisdirty())
260  * should be stable without having to acquire any new locks.
261  */
262 void
263 hammer_inode_dirty(struct hammer_inode *ip)
264 {
265 	struct vnode *vp;
266 
267 	if ((ip->flags & HAMMER_INODE_MODMASK) &&
268 	    (vp = ip->vp) != NULL &&
269 	    (vp->v_flag & (VRECLAIMED | VISDIRTY)) == 0) {
270 		vsetisdirty(vp);
271 	}
272 }
273 
274 /*
275  * Return a locked vnode for the specified inode.  The inode must be
276  * referenced but NOT LOCKED on entry and will remain referenced on
277  * return.
278  *
279  * Called from the frontend.
280  */
281 int
282 hammer_get_vnode(struct hammer_inode *ip, struct vnode **vpp)
283 {
284 	hammer_mount_t hmp;
285 	struct vnode *vp;
286 	int error = 0;
287 	u_int8_t obj_type;
288 
289 	hmp = ip->hmp;
290 
291 	for (;;) {
292 		if ((vp = ip->vp) == NULL) {
293 			error = getnewvnode(VT_HAMMER, hmp->mp, vpp, 0, 0);
294 			if (error)
295 				break;
296 			hammer_lock_ex(&ip->lock);
297 			if (ip->vp != NULL) {
298 				hammer_unlock(&ip->lock);
299 				vp = *vpp;
300 				vp->v_type = VBAD;
301 				vx_put(vp);
302 				continue;
303 			}
304 			hammer_ref(&ip->lock);
305 			vp = *vpp;
306 			ip->vp = vp;
307 
308 			obj_type = ip->ino_data.obj_type;
309 			vp->v_type = hammer_get_vnode_type(obj_type);
310 
311 			hammer_inode_wakereclaims(ip);
312 
313 			switch(ip->ino_data.obj_type) {
314 			case HAMMER_OBJTYPE_CDEV:
315 			case HAMMER_OBJTYPE_BDEV:
316 				vp->v_ops = &hmp->mp->mnt_vn_spec_ops;
317 				addaliasu(vp, ip->ino_data.rmajor,
318 					  ip->ino_data.rminor);
319 				break;
320 			case HAMMER_OBJTYPE_FIFO:
321 				vp->v_ops = &hmp->mp->mnt_vn_fifo_ops;
322 				break;
323 			case HAMMER_OBJTYPE_REGFILE:
324 				break;
325 			default:
326 				break;
327 			}
328 
329 			/*
330 			 * Only mark as the root vnode if the ip is not
331 			 * historical, otherwise the VFS cache will get
332 			 * confused.  The other half of the special handling
333 			 * is in hammer_vop_nlookupdotdot().
334 			 *
335 			 * Pseudo-filesystem roots can be accessed via
336 			 * non-root filesystem paths and setting VROOT may
337 			 * confuse the namecache.  Set VPFSROOT instead.
338 			 */
339 			if (ip->obj_id == HAMMER_OBJID_ROOT) {
340 				if (ip->obj_asof == hmp->asof) {
341 					if (ip->obj_localization == 0)
342 						vsetflags(vp, VROOT);
343 					else
344 						vsetflags(vp, VPFSROOT);
345 				} else {
346 					vsetflags(vp, VPFSROOT);
347 				}
348 			}
349 
350 			vp->v_data = (void *)ip;
351 			/* vnode locked by getnewvnode() */
352 			/* make related vnode dirty if inode dirty? */
353 			hammer_unlock(&ip->lock);
354 			if (vp->v_type == VREG) {
355 				vinitvmio(vp, ip->ino_data.size,
356 					  hammer_blocksize(ip->ino_data.size),
357 					  hammer_blockoff(ip->ino_data.size));
358 			}
359 			break;
360 		}
361 
362 		/*
363 		 * Interlock vnode clearing.  This does not prevent the
364 		 * vnode from going into a reclaimed state but it does
365 		 * prevent it from being destroyed or reused so the vget()
366 		 * will properly fail.
367 		 */
368 		hammer_lock_ex(&ip->lock);
369 		if ((vp = ip->vp) == NULL) {
370 			hammer_unlock(&ip->lock);
371 			continue;
372 		}
373 		vhold(vp);
374 		hammer_unlock(&ip->lock);
375 
376 		/*
377 		 * loop if the vget fails (aka races), or if the vp
378 		 * no longer matches ip->vp.
379 		 */
380 		if (vget(vp, LK_EXCLUSIVE) == 0) {
381 			if (vp == ip->vp) {
382 				vdrop(vp);
383 				break;
384 			}
385 			vput(vp);
386 		}
387 		vdrop(vp);
388 	}
389 	*vpp = vp;
390 	return(error);
391 }
392 
393 /*
394  * Locate all copies of the inode for obj_id compatible with the specified
395  * asof, reference, and issue the related call-back.  This routine is used
396  * for direct-io invalidation and does not create any new inodes.
397  */
398 void
399 hammer_scan_inode_snapshots(hammer_mount_t hmp, hammer_inode_info_t iinfo,
400 		            int (*callback)(hammer_inode_t ip, void *data),
401 			    void *data)
402 {
403 	hammer_ino_rb_tree_RB_SCAN(&hmp->rb_inos_root,
404 				   hammer_inode_info_cmp_all_history,
405 				   callback, iinfo);
406 }
407 
408 /*
409  * Acquire a HAMMER inode.  The returned inode is not locked.  These functions
410  * do not attach or detach the related vnode (use hammer_get_vnode() for
411  * that).
412  *
413  * The flags argument is only applied for newly created inodes, and only
414  * certain flags are inherited.
415  *
416  * Called from the frontend.
417  */
418 struct hammer_inode *
419 hammer_get_inode(hammer_transaction_t trans, hammer_inode_t dip,
420 		 int64_t obj_id, hammer_tid_t asof, u_int32_t localization,
421 		 int flags, int *errorp)
422 {
423 	hammer_mount_t hmp = trans->hmp;
424 	struct hammer_node_cache *cachep;
425 	struct hammer_inode_info iinfo;
426 	struct hammer_cursor cursor;
427 	struct hammer_inode *ip;
428 
429 
430 	/*
431 	 * Determine if we already have an inode cached.  If we do then
432 	 * we are golden.
433 	 *
434 	 * If we find an inode with no vnode we have to mark the
435 	 * transaction such that hammer_inode_waitreclaims() is
436 	 * called later on to avoid building up an infinite number
437 	 * of inodes.  Otherwise we can continue to * add new inodes
438 	 * faster then they can be disposed of, even with the tsleep
439 	 * delay.
440 	 *
441 	 * If we find a dummy inode we return a failure so dounlink
442 	 * (which does another lookup) doesn't try to mess with the
443 	 * link count.  hammer_vop_nresolve() uses hammer_get_dummy_inode()
444 	 * to ref dummy inodes.
445 	 */
446 	iinfo.obj_id = obj_id;
447 	iinfo.obj_asof = asof;
448 	iinfo.obj_localization = localization;
449 loop:
450 	ip = hammer_ino_rb_tree_RB_LOOKUP_INFO(&hmp->rb_inos_root, &iinfo);
451 	if (ip) {
452 		if (ip->flags & HAMMER_INODE_DUMMY) {
453 			*errorp = ENOENT;
454 			return(NULL);
455 		}
456 		hammer_ref(&ip->lock);
457 		*errorp = 0;
458 		return(ip);
459 	}
460 
461 	/*
462 	 * Allocate a new inode structure and deal with races later.
463 	 */
464 	ip = kmalloc(sizeof(*ip), hmp->m_inodes, M_WAITOK|M_ZERO);
465 	++hammer_count_inodes;
466 	++hmp->count_inodes;
467 	ip->obj_id = obj_id;
468 	ip->obj_asof = iinfo.obj_asof;
469 	ip->obj_localization = localization;
470 	ip->hmp = hmp;
471 	ip->flags = flags & HAMMER_INODE_RO;
472 	ip->cache[0].ip = ip;
473 	ip->cache[1].ip = ip;
474 	ip->cache[2].ip = ip;
475 	ip->cache[3].ip = ip;
476 	if (hmp->ronly)
477 		ip->flags |= HAMMER_INODE_RO;
478 	ip->sync_trunc_off = ip->trunc_off = ip->save_trunc_off =
479 		0x7FFFFFFFFFFFFFFFLL;
480 	RB_INIT(&ip->rec_tree);
481 	TAILQ_INIT(&ip->target_list);
482 	hammer_ref(&ip->lock);
483 
484 	/*
485 	 * Locate the on-disk inode.  If this is a PFS root we always
486 	 * access the current version of the root inode and (if it is not
487 	 * a master) always access information under it with a snapshot
488 	 * TID.
489 	 *
490 	 * We cache recent inode lookups in this directory in dip->cache[2].
491 	 * If we can't find it we assume the inode we are looking for is
492 	 * close to the directory inode.
493 	 */
494 retry:
495 	cachep = NULL;
496 	if (dip) {
497 		if (dip->cache[2].node)
498 			cachep = &dip->cache[2];
499 		else
500 			cachep = &dip->cache[0];
501 	}
502 	hammer_init_cursor(trans, &cursor, cachep, NULL);
503 	cursor.key_beg.localization = localization + HAMMER_LOCALIZE_INODE;
504 	cursor.key_beg.obj_id = ip->obj_id;
505 	cursor.key_beg.key = 0;
506 	cursor.key_beg.create_tid = 0;
507 	cursor.key_beg.delete_tid = 0;
508 	cursor.key_beg.rec_type = HAMMER_RECTYPE_INODE;
509 	cursor.key_beg.obj_type = 0;
510 
511 	cursor.asof = iinfo.obj_asof;
512 	cursor.flags = HAMMER_CURSOR_GET_LEAF | HAMMER_CURSOR_GET_DATA |
513 		       HAMMER_CURSOR_ASOF;
514 
515 	*errorp = hammer_btree_lookup(&cursor);
516 	if (*errorp == EDEADLK) {
517 		hammer_done_cursor(&cursor);
518 		goto retry;
519 	}
520 
521 	/*
522 	 * On success the B-Tree lookup will hold the appropriate
523 	 * buffer cache buffers and provide a pointer to the requested
524 	 * information.  Copy the information to the in-memory inode
525 	 * and cache the B-Tree node to improve future operations.
526 	 */
527 	if (*errorp == 0) {
528 		ip->ino_leaf = cursor.node->ondisk->elms[cursor.index].leaf;
529 		ip->ino_data = cursor.data->inode;
530 
531 		/*
532 		 * cache[0] tries to cache the location of the object inode.
533 		 * The assumption is that it is near the directory inode.
534 		 *
535 		 * cache[1] tries to cache the location of the object data.
536 		 * We might have something in the governing directory from
537 		 * scan optimizations (see the strategy code in
538 		 * hammer_vnops.c).
539 		 *
540 		 * We update dip->cache[2], if possible, with the location
541 		 * of the object inode for future directory shortcuts.
542 		 */
543 		hammer_cache_node(&ip->cache[0], cursor.node);
544 		if (dip) {
545 			if (dip->cache[3].node) {
546 				hammer_cache_node(&ip->cache[1],
547 						  dip->cache[3].node);
548 			}
549 			hammer_cache_node(&dip->cache[2], cursor.node);
550 		}
551 
552 		/*
553 		 * The file should not contain any data past the file size
554 		 * stored in the inode.  Setting save_trunc_off to the
555 		 * file size instead of max reduces B-Tree lookup overheads
556 		 * on append by allowing the flusher to avoid checking for
557 		 * record overwrites.
558 		 */
559 		ip->save_trunc_off = ip->ino_data.size;
560 
561 		/*
562 		 * Locate and assign the pseudofs management structure to
563 		 * the inode.
564 		 */
565 		if (dip && dip->obj_localization == ip->obj_localization) {
566 			ip->pfsm = dip->pfsm;
567 			hammer_ref(&ip->pfsm->lock);
568 		} else {
569 			ip->pfsm = hammer_load_pseudofs(trans,
570 							ip->obj_localization,
571 							errorp);
572 			*errorp = 0;	/* ignore ENOENT */
573 		}
574 	}
575 
576 	/*
577 	 * The inode is placed on the red-black tree and will be synced to
578 	 * the media when flushed or by the filesystem sync.  If this races
579 	 * another instantiation/lookup the insertion will fail.
580 	 */
581 	if (*errorp == 0) {
582 		if (RB_INSERT(hammer_ino_rb_tree, &hmp->rb_inos_root, ip)) {
583 			hammer_free_inode(ip);
584 			hammer_done_cursor(&cursor);
585 			goto loop;
586 		}
587 		ip->flags |= HAMMER_INODE_ONDISK;
588 	} else {
589 		if (ip->flags & HAMMER_INODE_RSV_INODES) {
590 			ip->flags &= ~HAMMER_INODE_RSV_INODES; /* sanity */
591 			--hmp->rsv_inodes;
592 		}
593 
594 		hammer_free_inode(ip);
595 		ip = NULL;
596 	}
597 	hammer_done_cursor(&cursor);
598 
599 	/*
600 	 * NEWINODE is only set if the inode becomes dirty later,
601 	 * setting it here just leads to unnecessary stalls.
602 	 *
603 	 * trans->flags |= HAMMER_TRANSF_NEWINODE;
604 	 */
605 	return (ip);
606 }
607 
608 /*
609  * Get a dummy inode to placemark a broken directory entry.
610  */
611 struct hammer_inode *
612 hammer_get_dummy_inode(hammer_transaction_t trans, hammer_inode_t dip,
613 		 int64_t obj_id, hammer_tid_t asof, u_int32_t localization,
614 		 int flags, int *errorp)
615 {
616 	hammer_mount_t hmp = trans->hmp;
617 	struct hammer_inode_info iinfo;
618 	struct hammer_inode *ip;
619 
620 	/*
621 	 * Determine if we already have an inode cached.  If we do then
622 	 * we are golden.
623 	 *
624 	 * If we find an inode with no vnode we have to mark the
625 	 * transaction such that hammer_inode_waitreclaims() is
626 	 * called later on to avoid building up an infinite number
627 	 * of inodes.  Otherwise we can continue to * add new inodes
628 	 * faster then they can be disposed of, even with the tsleep
629 	 * delay.
630 	 *
631 	 * If we find a non-fake inode we return an error.  Only fake
632 	 * inodes can be returned by this routine.
633 	 */
634 	iinfo.obj_id = obj_id;
635 	iinfo.obj_asof = asof;
636 	iinfo.obj_localization = localization;
637 loop:
638 	*errorp = 0;
639 	ip = hammer_ino_rb_tree_RB_LOOKUP_INFO(&hmp->rb_inos_root, &iinfo);
640 	if (ip) {
641 		if ((ip->flags & HAMMER_INODE_DUMMY) == 0) {
642 			*errorp = ENOENT;
643 			return(NULL);
644 		}
645 		hammer_ref(&ip->lock);
646 		return(ip);
647 	}
648 
649 	/*
650 	 * Allocate a new inode structure and deal with races later.
651 	 */
652 	ip = kmalloc(sizeof(*ip), hmp->m_inodes, M_WAITOK|M_ZERO);
653 	++hammer_count_inodes;
654 	++hmp->count_inodes;
655 	ip->obj_id = obj_id;
656 	ip->obj_asof = iinfo.obj_asof;
657 	ip->obj_localization = localization;
658 	ip->hmp = hmp;
659 	ip->flags = flags | HAMMER_INODE_RO | HAMMER_INODE_DUMMY;
660 	ip->cache[0].ip = ip;
661 	ip->cache[1].ip = ip;
662 	ip->cache[2].ip = ip;
663 	ip->cache[3].ip = ip;
664 	ip->sync_trunc_off = ip->trunc_off = ip->save_trunc_off =
665 		0x7FFFFFFFFFFFFFFFLL;
666 	RB_INIT(&ip->rec_tree);
667 	TAILQ_INIT(&ip->target_list);
668 	hammer_ref(&ip->lock);
669 
670 	/*
671 	 * Populate the dummy inode.  Leave everything zero'd out.
672 	 *
673 	 * (ip->ino_leaf and ip->ino_data)
674 	 *
675 	 * Make the dummy inode a FIFO object which most copy programs
676 	 * will properly ignore.
677 	 */
678 	ip->save_trunc_off = ip->ino_data.size;
679 	ip->ino_data.obj_type = HAMMER_OBJTYPE_FIFO;
680 
681 	/*
682 	 * Locate and assign the pseudofs management structure to
683 	 * the inode.
684 	 */
685 	if (dip && dip->obj_localization == ip->obj_localization) {
686 		ip->pfsm = dip->pfsm;
687 		hammer_ref(&ip->pfsm->lock);
688 	} else {
689 		ip->pfsm = hammer_load_pseudofs(trans, ip->obj_localization,
690 						errorp);
691 		*errorp = 0;	/* ignore ENOENT */
692 	}
693 
694 	/*
695 	 * The inode is placed on the red-black tree and will be synced to
696 	 * the media when flushed or by the filesystem sync.  If this races
697 	 * another instantiation/lookup the insertion will fail.
698 	 *
699 	 * NOTE: Do not set HAMMER_INODE_ONDISK.  The inode is a fake.
700 	 */
701 	if (*errorp == 0) {
702 		if (RB_INSERT(hammer_ino_rb_tree, &hmp->rb_inos_root, ip)) {
703 			hammer_free_inode(ip);
704 			goto loop;
705 		}
706 	} else {
707 		if (ip->flags & HAMMER_INODE_RSV_INODES) {
708 			ip->flags &= ~HAMMER_INODE_RSV_INODES; /* sanity */
709 			--hmp->rsv_inodes;
710 		}
711 		hammer_free_inode(ip);
712 		ip = NULL;
713 	}
714 	trans->flags |= HAMMER_TRANSF_NEWINODE;
715 	return (ip);
716 }
717 
718 /*
719  * Return a referenced inode only if it is in our inode cache.
720  *
721  * Dummy inodes do not count.
722  */
723 struct hammer_inode *
724 hammer_find_inode(hammer_transaction_t trans, int64_t obj_id,
725 		  hammer_tid_t asof, u_int32_t localization)
726 {
727 	hammer_mount_t hmp = trans->hmp;
728 	struct hammer_inode_info iinfo;
729 	struct hammer_inode *ip;
730 
731 	iinfo.obj_id = obj_id;
732 	iinfo.obj_asof = asof;
733 	iinfo.obj_localization = localization;
734 
735 	ip = hammer_ino_rb_tree_RB_LOOKUP_INFO(&hmp->rb_inos_root, &iinfo);
736 	if (ip) {
737 		if (ip->flags & HAMMER_INODE_DUMMY)
738 			ip = NULL;
739 		else
740 			hammer_ref(&ip->lock);
741 	}
742 	return(ip);
743 }
744 
745 /*
746  * Create a new filesystem object, returning the inode in *ipp.  The
747  * returned inode will be referenced.  The inode is created in-memory.
748  *
749  * If pfsm is non-NULL the caller wishes to create the root inode for
750  * a master PFS.
751  */
752 int
753 hammer_create_inode(hammer_transaction_t trans, struct vattr *vap,
754 		    struct ucred *cred,
755 		    hammer_inode_t dip, const char *name, int namelen,
756 		    hammer_pseudofs_inmem_t pfsm, struct hammer_inode **ipp)
757 {
758 	hammer_mount_t hmp;
759 	hammer_inode_t ip;
760 	uid_t xuid;
761 	int error;
762 	int64_t namekey;
763 	u_int32_t dummy;
764 
765 	hmp = trans->hmp;
766 
767 	/*
768 	 * Disallow the creation of new inodes in directories which
769 	 * have been deleted.  In HAMMER, this will cause a record
770 	 * syncing assertion later on in the flush code.
771 	 */
772 	if (dip && dip->ino_data.nlinks == 0) {
773 		*ipp = NULL;
774                 return (EINVAL);
775 	}
776 
777 	/*
778 	 * Allocate inode
779 	 */
780 	ip = kmalloc(sizeof(*ip), hmp->m_inodes, M_WAITOK|M_ZERO);
781 	++hammer_count_inodes;
782 	++hmp->count_inodes;
783 	trans->flags |= HAMMER_TRANSF_NEWINODE;
784 
785 	if (pfsm) {
786 		KKASSERT(pfsm->localization != 0);
787 		ip->obj_id = HAMMER_OBJID_ROOT;
788 		ip->obj_localization = pfsm->localization;
789 	} else {
790 		KKASSERT(dip != NULL);
791 		namekey = hammer_directory_namekey(dip, name, namelen, &dummy);
792 		ip->obj_id = hammer_alloc_objid(hmp, dip, namekey);
793 		ip->obj_localization = dip->obj_localization;
794 	}
795 
796 	KKASSERT(ip->obj_id != 0);
797 	ip->obj_asof = hmp->asof;
798 	ip->hmp = hmp;
799 	ip->flush_state = HAMMER_FST_IDLE;
800 	ip->flags = HAMMER_INODE_DDIRTY |
801 		    HAMMER_INODE_ATIME | HAMMER_INODE_MTIME;
802 	ip->cache[0].ip = ip;
803 	ip->cache[1].ip = ip;
804 	ip->cache[2].ip = ip;
805 	ip->cache[3].ip = ip;
806 
807 	ip->trunc_off = 0x7FFFFFFFFFFFFFFFLL;
808 	/* ip->save_trunc_off = 0; (already zero) */
809 	RB_INIT(&ip->rec_tree);
810 	TAILQ_INIT(&ip->target_list);
811 
812 	ip->ino_data.atime = trans->time;
813 	ip->ino_data.mtime = trans->time;
814 	ip->ino_data.size = 0;
815 	ip->ino_data.nlinks = 0;
816 
817 	/*
818 	 * A nohistory designator on the parent directory is inherited by
819 	 * the child.  We will do this even for pseudo-fs creation... the
820 	 * sysad can turn it off.
821 	 */
822 	if (dip) {
823 		ip->ino_data.uflags = dip->ino_data.uflags &
824 				      (SF_NOHISTORY|UF_NOHISTORY|UF_NODUMP);
825 	}
826 
827 	ip->ino_leaf.base.btype = HAMMER_BTREE_TYPE_RECORD;
828 	ip->ino_leaf.base.localization = ip->obj_localization +
829 					 HAMMER_LOCALIZE_INODE;
830 	ip->ino_leaf.base.obj_id = ip->obj_id;
831 	ip->ino_leaf.base.key = 0;
832 	ip->ino_leaf.base.create_tid = 0;
833 	ip->ino_leaf.base.delete_tid = 0;
834 	ip->ino_leaf.base.rec_type = HAMMER_RECTYPE_INODE;
835 	ip->ino_leaf.base.obj_type = hammer_get_obj_type(vap->va_type);
836 
837 	ip->ino_data.obj_type = ip->ino_leaf.base.obj_type;
838 	ip->ino_data.version = HAMMER_INODE_DATA_VERSION;
839 	ip->ino_data.mode = vap->va_mode;
840 	ip->ino_data.ctime = trans->time;
841 
842 	/*
843 	 * If we are running version 2 or greater directory entries are
844 	 * inode-localized instead of data-localized.
845 	 */
846 	if (trans->hmp->version >= HAMMER_VOL_VERSION_TWO) {
847 		if (ip->ino_leaf.base.obj_type == HAMMER_OBJTYPE_DIRECTORY) {
848 			ip->ino_data.cap_flags |=
849 				HAMMER_INODE_CAP_DIR_LOCAL_INO;
850 		}
851 	}
852 	if (trans->hmp->version >= HAMMER_VOL_VERSION_SIX) {
853 		if (ip->ino_leaf.base.obj_type == HAMMER_OBJTYPE_DIRECTORY) {
854 			ip->ino_data.cap_flags |=
855 				HAMMER_INODE_CAP_DIRHASH_ALG1;
856 		}
857 	}
858 
859 	/*
860 	 * Setup the ".." pointer.  This only needs to be done for directories
861 	 * but we do it for all objects as a recovery aid if dip exists.
862 	 * The inode is probably a PFS root if dip is NULL.
863 	 */
864 	if (dip)
865 		ip->ino_data.parent_obj_id = dip->ino_leaf.base.obj_id;
866 #if 0
867 	/*
868 	 * The parent_obj_localization field only applies to pseudo-fs roots.
869 	 * XXX this is no longer applicable, PFSs are no longer directly
870 	 * tied into the parent's directory structure.
871 	 */
872 	if (ip->ino_data.obj_type == HAMMER_OBJTYPE_DIRECTORY &&
873 	    ip->obj_id == HAMMER_OBJID_ROOT) {
874 		ip->ino_data.ext.obj.parent_obj_localization =
875 						dip->obj_localization;
876 	}
877 #endif
878 
879 	switch(ip->ino_leaf.base.obj_type) {
880 	case HAMMER_OBJTYPE_CDEV:
881 	case HAMMER_OBJTYPE_BDEV:
882 		ip->ino_data.rmajor = vap->va_rmajor;
883 		ip->ino_data.rminor = vap->va_rminor;
884 		break;
885 	default:
886 		break;
887 	}
888 
889 	/*
890 	 * Calculate default uid/gid and overwrite with information from
891 	 * the vap.
892 	 */
893 	if (dip) {
894 		xuid = hammer_to_unix_xid(&dip->ino_data.uid);
895 		xuid = vop_helper_create_uid(hmp->mp, dip->ino_data.mode,
896 					     xuid, cred, &vap->va_mode);
897 	} else {
898 		xuid = 0;
899 	}
900 	ip->ino_data.mode = vap->va_mode;
901 
902 	if (vap->va_vaflags & VA_UID_UUID_VALID)
903 		ip->ino_data.uid = vap->va_uid_uuid;
904 	else if (vap->va_uid != (uid_t)VNOVAL)
905 		hammer_guid_to_uuid(&ip->ino_data.uid, vap->va_uid);
906 	else
907 		hammer_guid_to_uuid(&ip->ino_data.uid, xuid);
908 
909 	if (vap->va_vaflags & VA_GID_UUID_VALID)
910 		ip->ino_data.gid = vap->va_gid_uuid;
911 	else if (vap->va_gid != (gid_t)VNOVAL)
912 		hammer_guid_to_uuid(&ip->ino_data.gid, vap->va_gid);
913 	else if (dip)
914 		ip->ino_data.gid = dip->ino_data.gid;
915 
916 	hammer_ref(&ip->lock);
917 
918 	if (pfsm) {
919 		ip->pfsm = pfsm;
920 		hammer_ref(&pfsm->lock);
921 		error = 0;
922 	} else if (dip->obj_localization == ip->obj_localization) {
923 		ip->pfsm = dip->pfsm;
924 		hammer_ref(&ip->pfsm->lock);
925 		error = 0;
926 	} else {
927 		ip->pfsm = hammer_load_pseudofs(trans,
928 						ip->obj_localization,
929 						&error);
930 		error = 0;	/* ignore ENOENT */
931 	}
932 
933 	if (error) {
934 		hammer_free_inode(ip);
935 		ip = NULL;
936 	} else if (RB_INSERT(hammer_ino_rb_tree, &hmp->rb_inos_root, ip)) {
937 		hpanic("duplicate obj_id %llx", (long long)ip->obj_id);
938 		/* not reached */
939 		hammer_free_inode(ip);
940 	}
941 	*ipp = ip;
942 	return(error);
943 }
944 
945 /*
946  * Final cleanup / freeing of an inode structure
947  */
948 static void
949 hammer_free_inode(hammer_inode_t ip)
950 {
951 	struct hammer_mount *hmp;
952 
953 	hmp = ip->hmp;
954 	KKASSERT(hammer_oneref(&ip->lock));
955 	hammer_uncache_node(&ip->cache[0]);
956 	hammer_uncache_node(&ip->cache[1]);
957 	hammer_uncache_node(&ip->cache[2]);
958 	hammer_uncache_node(&ip->cache[3]);
959 	hammer_inode_wakereclaims(ip);
960 	if (ip->objid_cache)
961 		hammer_clear_objid(ip);
962 	--hammer_count_inodes;
963 	--hmp->count_inodes;
964 	if (ip->pfsm) {
965 		hammer_rel_pseudofs(hmp, ip->pfsm);
966 		ip->pfsm = NULL;
967 	}
968 	kfree(ip, hmp->m_inodes);
969 }
970 
971 /*
972  * Retrieve pseudo-fs data.  NULL will never be returned.
973  *
974  * If an error occurs *errorp will be set and a default template is returned,
975  * otherwise *errorp is set to 0.  Typically when an error occurs it will
976  * be ENOENT.
977  */
978 hammer_pseudofs_inmem_t
979 hammer_load_pseudofs(hammer_transaction_t trans,
980 		     u_int32_t localization, int *errorp)
981 {
982 	hammer_mount_t hmp = trans->hmp;
983 	hammer_inode_t ip;
984 	hammer_pseudofs_inmem_t pfsm;
985 	struct hammer_cursor cursor;
986 	int bytes;
987 
988 retry:
989 	pfsm = RB_LOOKUP(hammer_pfs_rb_tree, &hmp->rb_pfsm_root, localization);
990 	if (pfsm) {
991 		hammer_ref(&pfsm->lock);
992 		*errorp = 0;
993 		return(pfsm);
994 	}
995 
996 	/*
997 	 * PFS records are associated with the root inode (not the PFS root
998 	 * inode, but the real root).  Avoid an infinite recursion if loading
999 	 * the PFS for the real root.
1000 	 */
1001 	if (localization) {
1002 		ip = hammer_get_inode(trans, NULL, HAMMER_OBJID_ROOT,
1003 				      HAMMER_MAX_TID,
1004 				      HAMMER_DEF_LOCALIZATION, 0, errorp);
1005 	} else {
1006 		ip = NULL;
1007 	}
1008 
1009 	pfsm = kmalloc(sizeof(*pfsm), hmp->m_misc, M_WAITOK | M_ZERO);
1010 	pfsm->localization = localization;
1011 	pfsm->pfsd.unique_uuid = trans->rootvol->ondisk->vol_fsid;
1012 	pfsm->pfsd.shared_uuid = pfsm->pfsd.unique_uuid;
1013 
1014 	hammer_init_cursor(trans, &cursor, (ip ? &ip->cache[1] : NULL), ip);
1015 	cursor.key_beg.localization = HAMMER_DEF_LOCALIZATION +
1016 				      HAMMER_LOCALIZE_MISC;
1017 	cursor.key_beg.obj_id = HAMMER_OBJID_ROOT;
1018 	cursor.key_beg.create_tid = 0;
1019 	cursor.key_beg.delete_tid = 0;
1020 	cursor.key_beg.rec_type = HAMMER_RECTYPE_PFS;
1021 	cursor.key_beg.obj_type = 0;
1022 	cursor.key_beg.key = localization;
1023 	cursor.asof = HAMMER_MAX_TID;
1024 	cursor.flags |= HAMMER_CURSOR_ASOF;
1025 
1026 	if (ip)
1027 		*errorp = hammer_ip_lookup(&cursor);
1028 	else
1029 		*errorp = hammer_btree_lookup(&cursor);
1030 	if (*errorp == 0) {
1031 		*errorp = hammer_ip_resolve_data(&cursor);
1032 		if (*errorp == 0) {
1033 			if (cursor.data->pfsd.mirror_flags &
1034 			    HAMMER_PFSD_DELETED) {
1035 				*errorp = ENOENT;
1036 			} else {
1037 				bytes = cursor.leaf->data_len;
1038 				if (bytes > sizeof(pfsm->pfsd))
1039 					bytes = sizeof(pfsm->pfsd);
1040 				bcopy(cursor.data, &pfsm->pfsd, bytes);
1041 			}
1042 		}
1043 	}
1044 	hammer_done_cursor(&cursor);
1045 
1046 	pfsm->fsid_udev = hammer_fsid_to_udev(&pfsm->pfsd.shared_uuid);
1047 	hammer_ref(&pfsm->lock);
1048 	if (ip)
1049 		hammer_rel_inode(ip, 0);
1050 	if (RB_INSERT(hammer_pfs_rb_tree, &hmp->rb_pfsm_root, pfsm)) {
1051 		kfree(pfsm, hmp->m_misc);
1052 		goto retry;
1053 	}
1054 	return(pfsm);
1055 }
1056 
1057 /*
1058  * Store pseudo-fs data.  The backend will automatically delete any prior
1059  * on-disk pseudo-fs data but we have to delete in-memory versions.
1060  */
1061 int
1062 hammer_save_pseudofs(hammer_transaction_t trans, hammer_pseudofs_inmem_t pfsm)
1063 {
1064 	struct hammer_cursor cursor;
1065 	hammer_record_t record;
1066 	hammer_inode_t ip;
1067 	int error;
1068 
1069 	/*
1070 	 * PFS records are associated with the root inode (not the PFS root
1071 	 * inode, but the real root).
1072 	 */
1073 	ip = hammer_get_inode(trans, NULL, HAMMER_OBJID_ROOT, HAMMER_MAX_TID,
1074 			      HAMMER_DEF_LOCALIZATION, 0, &error);
1075 retry:
1076 	pfsm->fsid_udev = hammer_fsid_to_udev(&pfsm->pfsd.shared_uuid);
1077 	hammer_init_cursor(trans, &cursor, &ip->cache[1], ip);
1078 	cursor.key_beg.localization = ip->obj_localization +
1079 				      HAMMER_LOCALIZE_MISC;
1080 	cursor.key_beg.obj_id = HAMMER_OBJID_ROOT;
1081 	cursor.key_beg.create_tid = 0;
1082 	cursor.key_beg.delete_tid = 0;
1083 	cursor.key_beg.rec_type = HAMMER_RECTYPE_PFS;
1084 	cursor.key_beg.obj_type = 0;
1085 	cursor.key_beg.key = pfsm->localization;
1086 	cursor.asof = HAMMER_MAX_TID;
1087 	cursor.flags |= HAMMER_CURSOR_ASOF;
1088 
1089 	/*
1090 	 * Replace any in-memory version of the record.
1091 	 */
1092 	error = hammer_ip_lookup(&cursor);
1093 	if (error == 0 && hammer_cursor_inmem(&cursor)) {
1094 		record = cursor.iprec;
1095 		if (record->flags & HAMMER_RECF_INTERLOCK_BE) {
1096 			KKASSERT(cursor.deadlk_rec == NULL);
1097 			hammer_ref(&record->lock);
1098 			cursor.deadlk_rec = record;
1099 			error = EDEADLK;
1100 		} else {
1101 			record->flags |= HAMMER_RECF_DELETED_FE;
1102 			error = 0;
1103 		}
1104 	}
1105 
1106 	/*
1107 	 * Allocate replacement general record.  The backend flush will
1108 	 * delete any on-disk version of the record.
1109 	 */
1110 	if (error == 0 || error == ENOENT) {
1111 		record = hammer_alloc_mem_record(ip, sizeof(pfsm->pfsd));
1112 		record->type = HAMMER_MEM_RECORD_GENERAL;
1113 
1114 		record->leaf.base.localization = ip->obj_localization +
1115 						 HAMMER_LOCALIZE_MISC;
1116 		record->leaf.base.rec_type = HAMMER_RECTYPE_PFS;
1117 		record->leaf.base.key = pfsm->localization;
1118 		record->leaf.data_len = sizeof(pfsm->pfsd);
1119 		bcopy(&pfsm->pfsd, record->data, sizeof(pfsm->pfsd));
1120 		error = hammer_ip_add_record(trans, record);
1121 	}
1122 	hammer_done_cursor(&cursor);
1123 	if (error == EDEADLK)
1124 		goto retry;
1125 	hammer_rel_inode(ip, 0);
1126 	return(error);
1127 }
1128 
1129 /*
1130  * Create a root directory for a PFS if one does not alredy exist.
1131  *
1132  * The PFS root stands alone so we must also bump the nlinks count
1133  * to prevent it from being destroyed on release.
1134  */
1135 int
1136 hammer_mkroot_pseudofs(hammer_transaction_t trans, struct ucred *cred,
1137 		       hammer_pseudofs_inmem_t pfsm)
1138 {
1139 	hammer_inode_t ip;
1140 	struct vattr vap;
1141 	int error;
1142 
1143 	ip = hammer_get_inode(trans, NULL, HAMMER_OBJID_ROOT, HAMMER_MAX_TID,
1144 			      pfsm->localization, 0, &error);
1145 	if (ip == NULL) {
1146 		vattr_null(&vap);
1147 		vap.va_mode = 0755;
1148 		vap.va_type = VDIR;
1149 		error = hammer_create_inode(trans, &vap, cred,
1150 					    NULL, NULL, 0,
1151 					    pfsm, &ip);
1152 		if (error == 0) {
1153 			++ip->ino_data.nlinks;
1154 			hammer_modify_inode(trans, ip, HAMMER_INODE_DDIRTY);
1155 		}
1156 	}
1157 	if (ip)
1158 		hammer_rel_inode(ip, 0);
1159 	return(error);
1160 }
1161 
1162 /*
1163  * Unload any vnodes & inodes associated with a PFS, return ENOTEMPTY
1164  * if we are unable to disassociate all the inodes.
1165  */
1166 static
1167 int
1168 hammer_unload_pseudofs_callback(hammer_inode_t ip, void *data)
1169 {
1170 	int res;
1171 
1172 	hammer_ref(&ip->lock);
1173 	if (ip->vp && (ip->vp->v_flag & VPFSROOT)) {
1174 		/*
1175 		 * The hammer pfs-upgrade directive itself might have the
1176 		 * root of the pfs open.  Just allow it.
1177 		 */
1178 		res = 0;
1179 	} else {
1180 		/*
1181 		 * Don't allow any subdirectories or files to be open.
1182 		 */
1183 		if (hammer_isactive(&ip->lock) == 2 && ip->vp)
1184 			vclean_unlocked(ip->vp);
1185 		if (hammer_isactive(&ip->lock) == 1 && ip->vp == NULL)
1186 			res = 0;
1187 		else
1188 			res = -1;	/* stop, someone is using the inode */
1189 	}
1190 	hammer_rel_inode(ip, 0);
1191 	return(res);
1192 }
1193 
1194 int
1195 hammer_unload_pseudofs(hammer_transaction_t trans, u_int32_t localization)
1196 {
1197 	int res;
1198 	int try;
1199 
1200 	for (try = res = 0; try < 4; ++try) {
1201 		res = hammer_ino_rb_tree_RB_SCAN(&trans->hmp->rb_inos_root,
1202 					   hammer_inode_pfs_cmp,
1203 					   hammer_unload_pseudofs_callback,
1204 					   &localization);
1205 		if (res == 0 && try > 1)
1206 			break;
1207 		hammer_flusher_sync(trans->hmp);
1208 	}
1209 	if (res != 0)
1210 		res = ENOTEMPTY;
1211 	return(res);
1212 }
1213 
1214 
1215 /*
1216  * Release a reference on a PFS
1217  */
1218 void
1219 hammer_rel_pseudofs(hammer_mount_t hmp, hammer_pseudofs_inmem_t pfsm)
1220 {
1221 	hammer_rel(&pfsm->lock);
1222 	if (hammer_norefs(&pfsm->lock)) {
1223 		RB_REMOVE(hammer_pfs_rb_tree, &hmp->rb_pfsm_root, pfsm);
1224 		kfree(pfsm, hmp->m_misc);
1225 	}
1226 }
1227 
1228 /*
1229  * Called by hammer_sync_inode().
1230  */
1231 static int
1232 hammer_update_inode(hammer_cursor_t cursor, hammer_inode_t ip)
1233 {
1234 	hammer_transaction_t trans = cursor->trans;
1235 	hammer_record_t record;
1236 	int error;
1237 	int redirty;
1238 
1239 retry:
1240 	error = 0;
1241 
1242 	/*
1243 	 * If the inode has a presence on-disk then locate it and mark
1244 	 * it deleted, setting DELONDISK.
1245 	 *
1246 	 * The record may or may not be physically deleted, depending on
1247 	 * the retention policy.
1248 	 */
1249 	if ((ip->flags & (HAMMER_INODE_ONDISK|HAMMER_INODE_DELONDISK)) ==
1250 	    HAMMER_INODE_ONDISK) {
1251 		hammer_normalize_cursor(cursor);
1252 		cursor->key_beg.localization = ip->obj_localization +
1253 					       HAMMER_LOCALIZE_INODE;
1254 		cursor->key_beg.obj_id = ip->obj_id;
1255 		cursor->key_beg.key = 0;
1256 		cursor->key_beg.create_tid = 0;
1257 		cursor->key_beg.delete_tid = 0;
1258 		cursor->key_beg.rec_type = HAMMER_RECTYPE_INODE;
1259 		cursor->key_beg.obj_type = 0;
1260 		cursor->asof = ip->obj_asof;
1261 		cursor->flags &= ~HAMMER_CURSOR_INITMASK;
1262 		cursor->flags |= HAMMER_CURSOR_GET_LEAF | HAMMER_CURSOR_ASOF;
1263 		cursor->flags |= HAMMER_CURSOR_BACKEND;
1264 
1265 		error = hammer_btree_lookup(cursor);
1266 		if (hammer_debug_inode)
1267 			hdkprintf("IPDEL %p %08x %d", ip, ip->flags, error);
1268 
1269 		if (error == 0) {
1270 			error = hammer_ip_delete_record(cursor, ip, trans->tid);
1271 			if (hammer_debug_inode)
1272 				hdkprintf("error %d\n", error);
1273 			if (error == 0) {
1274 				ip->flags |= HAMMER_INODE_DELONDISK;
1275 			}
1276 			if (cursor->node)
1277 				hammer_cache_node(&ip->cache[0], cursor->node);
1278 		}
1279 		if (error == EDEADLK) {
1280 			hammer_done_cursor(cursor);
1281 			error = hammer_init_cursor(trans, cursor,
1282 						   &ip->cache[0], ip);
1283 			if (hammer_debug_inode)
1284 				hdkprintf("IPDED %p %d\n", ip, error);
1285 			if (error == 0)
1286 				goto retry;
1287 		}
1288 	}
1289 
1290 	/*
1291 	 * Ok, write out the initial record or a new record (after deleting
1292 	 * the old one), unless the DELETED flag is set.  This routine will
1293 	 * clear DELONDISK if it writes out a record.
1294 	 *
1295 	 * Update our inode statistics if this is the first application of
1296 	 * the inode on-disk.
1297 	 */
1298 	if (error == 0 && (ip->flags & HAMMER_INODE_DELETED) == 0) {
1299 		/*
1300 		 * Generate a record and write it to the media.  We clean-up
1301 		 * the state before releasing so we do not have to set-up
1302 		 * a flush_group.
1303 		 */
1304 		record = hammer_alloc_mem_record(ip, 0);
1305 		record->type = HAMMER_MEM_RECORD_INODE;
1306 		record->flush_state = HAMMER_FST_FLUSH;
1307 		record->leaf = ip->sync_ino_leaf;
1308 		record->leaf.base.create_tid = trans->tid;
1309 		record->leaf.data_len = sizeof(ip->sync_ino_data);
1310 		record->leaf.create_ts = trans->time32;
1311 		record->data = (void *)&ip->sync_ino_data;
1312 		record->flags |= HAMMER_RECF_INTERLOCK_BE;
1313 
1314 		/*
1315 		 * If this flag is set we cannot sync the new file size
1316 		 * because we haven't finished related truncations.  The
1317 		 * inode will be flushed in another flush group to finish
1318 		 * the job.
1319 		 */
1320 		if ((ip->flags & HAMMER_INODE_WOULDBLOCK) &&
1321 		    ip->sync_ino_data.size != ip->ino_data.size) {
1322 			redirty = 1;
1323 			ip->sync_ino_data.size = ip->ino_data.size;
1324 		} else {
1325 			redirty = 0;
1326 		}
1327 
1328 		for (;;) {
1329 			error = hammer_ip_sync_record_cursor(cursor, record);
1330 			if (hammer_debug_inode)
1331 				hdkprintf("GENREC %p rec %08x %d\n",
1332 					ip, record->flags, error);
1333 			if (error != EDEADLK)
1334 				break;
1335 			hammer_done_cursor(cursor);
1336 			error = hammer_init_cursor(trans, cursor,
1337 						   &ip->cache[0], ip);
1338 			if (hammer_debug_inode)
1339 				hdkprintf("GENREC reinit %d\n", error);
1340 			if (error)
1341 				break;
1342 		}
1343 
1344 		/*
1345 		 * Note:  The record was never on the inode's record tree
1346 		 * so just wave our hands importantly and destroy it.
1347 		 */
1348 		record->flags |= HAMMER_RECF_COMMITTED;
1349 		record->flags &= ~HAMMER_RECF_INTERLOCK_BE;
1350 		record->flush_state = HAMMER_FST_IDLE;
1351 		++ip->rec_generation;
1352 		hammer_rel_mem_record(record);
1353 
1354 		/*
1355 		 * Finish up.
1356 		 */
1357 		if (error == 0) {
1358 			if (hammer_debug_inode)
1359 				hdkprintf("CLEANDELOND %p %08x\n", ip, ip->flags);
1360 			ip->sync_flags &= ~(HAMMER_INODE_DDIRTY |
1361 					    HAMMER_INODE_SDIRTY |
1362 					    HAMMER_INODE_ATIME |
1363 					    HAMMER_INODE_MTIME);
1364 			ip->flags &= ~HAMMER_INODE_DELONDISK;
1365 			if (redirty)
1366 				ip->sync_flags |= HAMMER_INODE_DDIRTY;
1367 
1368 			/*
1369 			 * Root volume count of inodes
1370 			 */
1371 			hammer_sync_lock_sh(trans);
1372 			if ((ip->flags & HAMMER_INODE_ONDISK) == 0) {
1373 				hammer_modify_volume_field(trans,
1374 							   trans->rootvol,
1375 							   vol0_stat_inodes);
1376 				++ip->hmp->rootvol->ondisk->vol0_stat_inodes;
1377 				hammer_modify_volume_done(trans->rootvol);
1378 				ip->flags |= HAMMER_INODE_ONDISK;
1379 				if (hammer_debug_inode)
1380 					hdkprintf("NOWONDISK %p\n", ip);
1381 			}
1382 			hammer_sync_unlock(trans);
1383 		}
1384 	}
1385 
1386 	/*
1387 	 * If the inode has been destroyed, clean out any left-over flags
1388 	 * that may have been set by the frontend.
1389 	 */
1390 	if (error == 0 && (ip->flags & HAMMER_INODE_DELETED)) {
1391 		ip->sync_flags &= ~(HAMMER_INODE_DDIRTY |
1392 				    HAMMER_INODE_SDIRTY |
1393 				    HAMMER_INODE_ATIME |
1394 				    HAMMER_INODE_MTIME);
1395 	}
1396 	return(error);
1397 }
1398 
1399 /*
1400  * Update only the itimes fields.
1401  *
1402  * ATIME can be updated without generating any UNDO.  MTIME is updated
1403  * with UNDO so it is guaranteed to be synchronized properly in case of
1404  * a crash.
1405  *
1406  * Neither field is included in the B-Tree leaf element's CRC, which is how
1407  * we can get away with updating ATIME the way we do.
1408  */
1409 static int
1410 hammer_update_itimes(hammer_cursor_t cursor, hammer_inode_t ip)
1411 {
1412 	hammer_transaction_t trans = cursor->trans;
1413 	int error;
1414 
1415 retry:
1416 	if ((ip->flags & (HAMMER_INODE_ONDISK|HAMMER_INODE_DELONDISK)) !=
1417 	    HAMMER_INODE_ONDISK) {
1418 		return(0);
1419 	}
1420 
1421 	hammer_normalize_cursor(cursor);
1422 	cursor->key_beg.localization = ip->obj_localization +
1423 				       HAMMER_LOCALIZE_INODE;
1424 	cursor->key_beg.obj_id = ip->obj_id;
1425 	cursor->key_beg.key = 0;
1426 	cursor->key_beg.create_tid = 0;
1427 	cursor->key_beg.delete_tid = 0;
1428 	cursor->key_beg.rec_type = HAMMER_RECTYPE_INODE;
1429 	cursor->key_beg.obj_type = 0;
1430 	cursor->asof = ip->obj_asof;
1431 	cursor->flags &= ~HAMMER_CURSOR_INITMASK;
1432 	cursor->flags |= HAMMER_CURSOR_ASOF;
1433 	cursor->flags |= HAMMER_CURSOR_GET_LEAF;
1434 	cursor->flags |= HAMMER_CURSOR_GET_DATA;
1435 	cursor->flags |= HAMMER_CURSOR_BACKEND;
1436 
1437 	error = hammer_btree_lookup(cursor);
1438 	if (error == 0) {
1439 		hammer_cache_node(&ip->cache[0], cursor->node);
1440 		if (ip->sync_flags & HAMMER_INODE_MTIME) {
1441 			/*
1442 			 * Updating MTIME requires an UNDO.  Just cover
1443 			 * both atime and mtime.
1444 			 */
1445 			hammer_sync_lock_sh(trans);
1446 			hammer_modify_buffer(trans, cursor->data_buffer,
1447 				     HAMMER_ITIMES_BASE(&cursor->data->inode),
1448 				     HAMMER_ITIMES_BYTES);
1449 			cursor->data->inode.atime = ip->sync_ino_data.atime;
1450 			cursor->data->inode.mtime = ip->sync_ino_data.mtime;
1451 			hammer_modify_buffer_done(cursor->data_buffer);
1452 			hammer_sync_unlock(trans);
1453 		} else if (ip->sync_flags & HAMMER_INODE_ATIME) {
1454 			/*
1455 			 * Updating atime only can be done in-place with
1456 			 * no UNDO.
1457 			 */
1458 			hammer_sync_lock_sh(trans);
1459 			hammer_modify_buffer(trans, cursor->data_buffer,
1460 					     NULL, 0);
1461 			cursor->data->inode.atime = ip->sync_ino_data.atime;
1462 			hammer_modify_buffer_done(cursor->data_buffer);
1463 			hammer_sync_unlock(trans);
1464 		}
1465 		ip->sync_flags &= ~(HAMMER_INODE_ATIME | HAMMER_INODE_MTIME);
1466 	}
1467 	if (error == EDEADLK) {
1468 		hammer_done_cursor(cursor);
1469 		error = hammer_init_cursor(trans, cursor, &ip->cache[0], ip);
1470 		if (error == 0)
1471 			goto retry;
1472 	}
1473 	return(error);
1474 }
1475 
1476 /*
1477  * Release a reference on an inode, flush as requested.
1478  *
1479  * On the last reference we queue the inode to the flusher for its final
1480  * disposition.
1481  */
1482 void
1483 hammer_rel_inode(struct hammer_inode *ip, int flush)
1484 {
1485 	/*
1486 	 * Handle disposition when dropping the last ref.
1487 	 */
1488 	for (;;) {
1489 		if (hammer_oneref(&ip->lock)) {
1490 			/*
1491 			 * Determine whether on-disk action is needed for
1492 			 * the inode's final disposition.
1493 			 */
1494 			KKASSERT(ip->vp == NULL);
1495 			hammer_inode_unloadable_check(ip, 0);
1496 			if (ip->flags & HAMMER_INODE_MODMASK) {
1497 				hammer_flush_inode(ip, 0);
1498 			} else if (hammer_oneref(&ip->lock)) {
1499 				hammer_unload_inode(ip);
1500 				break;
1501 			}
1502 		} else {
1503 			if (flush)
1504 				hammer_flush_inode(ip, 0);
1505 
1506 			/*
1507 			 * The inode still has multiple refs, try to drop
1508 			 * one ref.
1509 			 */
1510 			KKASSERT(hammer_isactive(&ip->lock) >= 1);
1511 			if (hammer_isactive(&ip->lock) > 1) {
1512 				hammer_rel(&ip->lock);
1513 				break;
1514 			}
1515 		}
1516 	}
1517 }
1518 
1519 /*
1520  * Unload and destroy the specified inode.  Must be called with one remaining
1521  * reference.  The reference is disposed of.
1522  *
1523  * The inode must be completely clean.
1524  */
1525 static int
1526 hammer_unload_inode(struct hammer_inode *ip)
1527 {
1528 	hammer_mount_t hmp = ip->hmp;
1529 
1530 	KASSERT(hammer_oneref(&ip->lock),
1531 		("hammer_unload_inode: %d refs", hammer_isactive(&ip->lock)));
1532 	KKASSERT(ip->vp == NULL);
1533 	KKASSERT(ip->flush_state == HAMMER_FST_IDLE);
1534 	KKASSERT(ip->cursor_ip_refs == 0);
1535 	KKASSERT(hammer_notlocked(&ip->lock));
1536 	KKASSERT((ip->flags & HAMMER_INODE_MODMASK) == 0);
1537 
1538 	KKASSERT(RB_EMPTY(&ip->rec_tree));
1539 	KKASSERT(TAILQ_EMPTY(&ip->target_list));
1540 
1541 	if (ip->flags & HAMMER_INODE_RDIRTY) {
1542 		RB_REMOVE(hammer_redo_rb_tree, &hmp->rb_redo_root, ip);
1543 		ip->flags &= ~HAMMER_INODE_RDIRTY;
1544 	}
1545 	RB_REMOVE(hammer_ino_rb_tree, &hmp->rb_inos_root, ip);
1546 
1547 	hammer_free_inode(ip);
1548 	return(0);
1549 }
1550 
1551 /*
1552  * Called during unmounting if a critical error occured.  The in-memory
1553  * inode and all related structures are destroyed.
1554  *
1555  * If a critical error did not occur the unmount code calls the standard
1556  * release and asserts that the inode is gone.
1557  */
1558 int
1559 hammer_destroy_inode_callback(struct hammer_inode *ip, void *data __unused)
1560 {
1561 	hammer_record_t rec;
1562 
1563 	/*
1564 	 * Get rid of the inodes in-memory records, regardless of their
1565 	 * state, and clear the mod-mask.
1566 	 */
1567 	while ((rec = TAILQ_FIRST(&ip->target_list)) != NULL) {
1568 		TAILQ_REMOVE(&ip->target_list, rec, target_entry);
1569 		rec->target_ip = NULL;
1570 		if (rec->flush_state == HAMMER_FST_SETUP)
1571 			rec->flush_state = HAMMER_FST_IDLE;
1572 	}
1573 	while ((rec = RB_ROOT(&ip->rec_tree)) != NULL) {
1574 		if (rec->flush_state == HAMMER_FST_FLUSH)
1575 			--rec->flush_group->refs;
1576 		else
1577 			hammer_ref(&rec->lock);
1578 		KKASSERT(hammer_oneref(&rec->lock));
1579 		rec->flush_state = HAMMER_FST_IDLE;
1580 		rec->flush_group = NULL;
1581 		rec->flags |= HAMMER_RECF_DELETED_FE; /* wave hands */
1582 		rec->flags |= HAMMER_RECF_DELETED_BE; /* wave hands */
1583 		++ip->rec_generation;
1584 		hammer_rel_mem_record(rec);
1585 	}
1586 	ip->flags &= ~HAMMER_INODE_MODMASK;
1587 	ip->sync_flags &= ~HAMMER_INODE_MODMASK;
1588 	KKASSERT(ip->vp == NULL);
1589 
1590 	/*
1591 	 * Remove the inode from any flush group, force it idle.  FLUSH
1592 	 * and SETUP states have an inode ref.
1593 	 */
1594 	switch(ip->flush_state) {
1595 	case HAMMER_FST_FLUSH:
1596 		RB_REMOVE(hammer_fls_rb_tree, &ip->flush_group->flush_tree, ip);
1597 		--ip->flush_group->refs;
1598 		ip->flush_group = NULL;
1599 		/* fall through */
1600 	case HAMMER_FST_SETUP:
1601 		hammer_rel(&ip->lock);
1602 		ip->flush_state = HAMMER_FST_IDLE;
1603 		/* fall through */
1604 	case HAMMER_FST_IDLE:
1605 		break;
1606 	}
1607 
1608 	/*
1609 	 * There shouldn't be any associated vnode.  The unload needs at
1610 	 * least one ref, if we do have a vp steal its ip ref.
1611 	 */
1612 	if (ip->vp) {
1613 		hdkprintf("Unexpected vnode association ip %p vp %p\n",
1614 			ip, ip->vp);
1615 		ip->vp->v_data = NULL;
1616 		ip->vp = NULL;
1617 	} else {
1618 		hammer_ref(&ip->lock);
1619 	}
1620 	hammer_unload_inode(ip);
1621 	return(0);
1622 }
1623 
1624 /*
1625  * Called on mount -u when switching from RW to RO or vise-versa.  Adjust
1626  * the read-only flag for cached inodes.
1627  *
1628  * This routine is called from a RB_SCAN().
1629  */
1630 int
1631 hammer_reload_inode(hammer_inode_t ip, void *arg __unused)
1632 {
1633 	hammer_mount_t hmp = ip->hmp;
1634 
1635 	if (hmp->ronly || hmp->asof != HAMMER_MAX_TID)
1636 		ip->flags |= HAMMER_INODE_RO;
1637 	else
1638 		ip->flags &= ~HAMMER_INODE_RO;
1639 	return(0);
1640 }
1641 
1642 /*
1643  * A transaction has modified an inode, requiring updates as specified by
1644  * the passed flags.
1645  *
1646  * HAMMER_INODE_DDIRTY: Inode data has been updated, not incl mtime/atime,
1647  *			and not including size changes due to write-append
1648  *			(but other size changes are included).
1649  * HAMMER_INODE_SDIRTY: Inode data has been updated, size changes due to
1650  *			write-append.
1651  * HAMMER_INODE_XDIRTY: Dirty in-memory records
1652  * HAMMER_INODE_BUFS:   Dirty buffer cache buffers
1653  * HAMMER_INODE_DELETED: Inode record/data must be deleted
1654  * HAMMER_INODE_ATIME/MTIME: mtime/atime has been updated
1655  */
1656 void
1657 hammer_modify_inode(hammer_transaction_t trans, hammer_inode_t ip, int flags)
1658 {
1659 	/*
1660 	 * ronly of 0 or 2 does not trigger assertion.
1661 	 * 2 is a special error state
1662 	 */
1663 	KKASSERT(ip->hmp->ronly != 1 ||
1664 		  (flags & (HAMMER_INODE_DDIRTY | HAMMER_INODE_XDIRTY |
1665 			    HAMMER_INODE_SDIRTY |
1666 			    HAMMER_INODE_BUFS | HAMMER_INODE_DELETED |
1667 			    HAMMER_INODE_ATIME | HAMMER_INODE_MTIME)) == 0);
1668 	if ((ip->flags & HAMMER_INODE_RSV_INODES) == 0) {
1669 		ip->flags |= HAMMER_INODE_RSV_INODES;
1670 		++ip->hmp->rsv_inodes;
1671 	}
1672 
1673 	/*
1674 	 * Set the NEWINODE flag in the transaction if the inode
1675 	 * transitions to a dirty state.  This is used to track
1676 	 * the load on the inode cache.
1677 	 */
1678 	if (trans &&
1679 	    (ip->flags & HAMMER_INODE_MODMASK) == 0 &&
1680 	    (flags & HAMMER_INODE_MODMASK)) {
1681 		trans->flags |= HAMMER_TRANSF_NEWINODE;
1682 	}
1683 	if (flags & HAMMER_INODE_MODMASK)
1684 		hammer_inode_dirty(ip);
1685 	ip->flags |= flags;
1686 }
1687 
1688 /*
1689  * Attempt to quickly update the atime for a hammer inode.  Return 0 on
1690  * success, -1 on failure.
1691  *
1692  * We attempt to update the atime with only the ip lock and not the
1693  * whole filesystem lock in order to improve concurrency.  We can only
1694  * do this safely if the ATIME flag is already pending on the inode.
1695  *
1696  * This function is called via a vnops path (ip pointer is stable) without
1697  * fs_token held.
1698  */
1699 int
1700 hammer_update_atime_quick(hammer_inode_t ip)
1701 {
1702 	struct timeval tv;
1703 	int res = -1;
1704 
1705 	if ((ip->flags & HAMMER_INODE_RO) ||
1706 	    (ip->hmp->mp->mnt_flag & MNT_NOATIME)) {
1707 		/*
1708 		 * Silently indicate success on read-only mount/snap
1709 		 */
1710 		res = 0;
1711 	} else if (ip->flags & HAMMER_INODE_ATIME) {
1712 		/*
1713 		 * Double check with inode lock held against backend.  This
1714 		 * is only safe if all we need to do is update
1715 		 * ino_data.atime.
1716 		 */
1717 		getmicrotime(&tv);
1718 		hammer_lock_ex(&ip->lock);
1719 		if (ip->flags & HAMMER_INODE_ATIME) {
1720 			ip->ino_data.atime =
1721 			    (unsigned long)tv.tv_sec * 1000000ULL + tv.tv_usec;
1722 			res = 0;
1723 		}
1724 		hammer_unlock(&ip->lock);
1725 	}
1726 	return res;
1727 }
1728 
1729 /*
1730  * Request that an inode be flushed.  This whole mess cannot block and may
1731  * recurse (if not synchronous).  Once requested HAMMER will attempt to
1732  * actively flush the inode until the flush can be done.
1733  *
1734  * The inode may already be flushing, or may be in a setup state.  We can
1735  * place the inode in a flushing state if it is currently idle and flag it
1736  * to reflush if it is currently flushing.
1737  *
1738  * Upon return if the inode could not be flushed due to a setup
1739  * dependancy, then it will be automatically flushed when the dependancy
1740  * is satisfied.
1741  */
1742 void
1743 hammer_flush_inode(hammer_inode_t ip, int flags)
1744 {
1745 	hammer_mount_t hmp;
1746 	hammer_flush_group_t flg;
1747 	int good;
1748 
1749 	/*
1750 	 * fill_flush_group is the first flush group we may be able to
1751 	 * continue filling, it may be open or closed but it will always
1752 	 * be past the currently flushing (running) flg.
1753 	 *
1754 	 * next_flush_group is the next open flush group.
1755 	 */
1756 	hmp = ip->hmp;
1757 	while ((flg = hmp->fill_flush_group) != NULL) {
1758 		KKASSERT(flg->running == 0);
1759 		if (flg->total_count + flg->refs <= ip->hmp->undo_rec_limit &&
1760 		    flg->total_count <= hammer_autoflush) {
1761 			break;
1762 		}
1763 		hmp->fill_flush_group = TAILQ_NEXT(flg, flush_entry);
1764 		hammer_flusher_async(ip->hmp, flg);
1765 	}
1766 	if (flg == NULL) {
1767 		flg = kmalloc(sizeof(*flg), hmp->m_misc, M_WAITOK|M_ZERO);
1768 		flg->seq = hmp->flusher.next++;
1769 		if (hmp->next_flush_group == NULL)
1770 			hmp->next_flush_group = flg;
1771 		if (hmp->fill_flush_group == NULL)
1772 			hmp->fill_flush_group = flg;
1773 		RB_INIT(&flg->flush_tree);
1774 		TAILQ_INSERT_TAIL(&hmp->flush_group_list, flg, flush_entry);
1775 	}
1776 
1777 	/*
1778 	 * Trivial 'nothing to flush' case.  If the inode is in a SETUP
1779 	 * state we have to put it back into an IDLE state so we can
1780 	 * drop the extra ref.
1781 	 *
1782 	 * If we have a parent dependancy we must still fall through
1783 	 * so we can run it.
1784 	 */
1785 	if ((ip->flags & HAMMER_INODE_MODMASK) == 0) {
1786 		if (ip->flush_state == HAMMER_FST_SETUP &&
1787 		    TAILQ_EMPTY(&ip->target_list)) {
1788 			ip->flush_state = HAMMER_FST_IDLE;
1789 			hammer_rel_inode(ip, 0);
1790 		}
1791 		if (ip->flush_state == HAMMER_FST_IDLE)
1792 			return;
1793 	}
1794 
1795 	/*
1796 	 * Our flush action will depend on the current state.
1797 	 */
1798 	switch(ip->flush_state) {
1799 	case HAMMER_FST_IDLE:
1800 		/*
1801 		 * We have no dependancies and can flush immediately.  Some
1802 		 * our children may not be flushable so we have to re-test
1803 		 * with that additional knowledge.
1804 		 */
1805 		hammer_flush_inode_core(ip, flg, flags);
1806 		break;
1807 	case HAMMER_FST_SETUP:
1808 		/*
1809 		 * Recurse upwards through dependancies via target_list
1810 		 * and start their flusher actions going if possible.
1811 		 *
1812 		 * 'good' is our connectivity.  -1 means we have none and
1813 		 * can't flush, 0 means there weren't any dependancies, and
1814 		 * 1 means we have good connectivity.
1815 		 */
1816 		good = hammer_setup_parent_inodes(ip, 0, flg);
1817 
1818 		if (good >= 0) {
1819 			/*
1820 			 * We can continue if good >= 0.  Determine how
1821 			 * many records under our inode can be flushed (and
1822 			 * mark them).
1823 			 */
1824 			hammer_flush_inode_core(ip, flg, flags);
1825 		} else {
1826 			/*
1827 			 * Parent has no connectivity, tell it to flush
1828 			 * us as soon as it does.
1829 			 *
1830 			 * The REFLUSH flag is also needed to trigger
1831 			 * dependancy wakeups.
1832 			 */
1833 			ip->flags |= HAMMER_INODE_CONN_DOWN |
1834 				     HAMMER_INODE_REFLUSH;
1835 			if (flags & HAMMER_FLUSH_SIGNAL) {
1836 				ip->flags |= HAMMER_INODE_RESIGNAL;
1837 				hammer_flusher_async(ip->hmp, flg);
1838 			}
1839 		}
1840 		break;
1841 	case HAMMER_FST_FLUSH:
1842 		/*
1843 		 * We are already flushing, flag the inode to reflush
1844 		 * if needed after it completes its current flush.
1845 		 *
1846 		 * The REFLUSH flag is also needed to trigger
1847 		 * dependancy wakeups.
1848 		 */
1849 		if ((ip->flags & HAMMER_INODE_REFLUSH) == 0)
1850 			ip->flags |= HAMMER_INODE_REFLUSH;
1851 		if (flags & HAMMER_FLUSH_SIGNAL) {
1852 			ip->flags |= HAMMER_INODE_RESIGNAL;
1853 			hammer_flusher_async(ip->hmp, flg);
1854 		}
1855 		break;
1856 	}
1857 }
1858 
1859 /*
1860  * Scan ip->target_list, which is a list of records owned by PARENTS to our
1861  * ip which reference our ip.
1862  *
1863  * XXX This is a huge mess of recursive code, but not one bit of it blocks
1864  *     so for now do not ref/deref the structures.  Note that if we use the
1865  *     ref/rel code later, the rel CAN block.
1866  */
1867 static int
1868 hammer_setup_parent_inodes(hammer_inode_t ip, int depth,
1869 			   hammer_flush_group_t flg)
1870 {
1871 	hammer_record_t depend;
1872 	int good;
1873 	int r;
1874 
1875 	/*
1876 	 * If we hit our recursion limit and we have parent dependencies
1877 	 * We cannot continue.  Returning < 0 will cause us to be flagged
1878 	 * for reflush.  Returning -2 cuts off additional dependency checks
1879 	 * because they are likely to also hit the depth limit.
1880 	 *
1881 	 * We cannot return < 0 if there are no dependencies or there might
1882 	 * not be anything to wakeup (ip).
1883 	 */
1884 	if (depth == 20 && TAILQ_FIRST(&ip->target_list)) {
1885 		if (hammer_debug_general & 0x10000)
1886 			hkrateprintf(&hammer_gen_krate,
1887 			    "Warning: depth limit reached on "
1888 			    "setup recursion, inode %p %016llx\n",
1889 			    ip, (long long)ip->obj_id);
1890 		return(-2);
1891 	}
1892 
1893 	/*
1894 	 * Scan dependencies
1895 	 */
1896 	good = 0;
1897 	TAILQ_FOREACH(depend, &ip->target_list, target_entry) {
1898 		r = hammer_setup_parent_inodes_helper(depend, depth, flg);
1899 		KKASSERT(depend->target_ip == ip);
1900 		if (r < 0 && good == 0)
1901 			good = -1;
1902 		if (r > 0)
1903 			good = 1;
1904 
1905 		/*
1906 		 * If we failed due to the recursion depth limit then stop
1907 		 * now.
1908 		 */
1909 		if (r == -2)
1910 			break;
1911 	}
1912 	return(good);
1913 }
1914 
1915 /*
1916  * This helper function takes a record representing the dependancy between
1917  * the parent inode and child inode.
1918  *
1919  * record		= record in question (*rec in below)
1920  * record->ip		= parent inode (*pip in below)
1921  * record->target_ip	= child inode (*ip in below)
1922  *
1923  * *pip--------------\
1924  *    ^               \rec_tree
1925  *     \               \
1926  *      \ip            /\\\\\ rbtree of recs from parent inode's view
1927  *       \            //\\\\\\
1928  *        \          / ........
1929  *         \        /
1930  *          \------*rec------target_ip------>*ip
1931  *               ...target_entry<----...----->target_list<---...
1932  *                                            list of recs from inode's view
1933  *
1934  * We are asked to recurse upwards and convert the record from SETUP
1935  * to FLUSH if possible.
1936  *
1937  * Return 1 if the record gives us connectivity
1938  *
1939  * Return 0 if the record is not relevant
1940  *
1941  * Return -1 if we can't resolve the dependancy and there is no connectivity.
1942  */
1943 static int
1944 hammer_setup_parent_inodes_helper(hammer_record_t record, int depth,
1945 				  hammer_flush_group_t flg)
1946 {
1947 	hammer_inode_t pip;
1948 	int good;
1949 
1950 	KKASSERT(record->flush_state != HAMMER_FST_IDLE);
1951 	pip = record->ip;
1952 
1953 	/*
1954 	 * If the record is already flushing, is it in our flush group?
1955 	 *
1956 	 * If it is in our flush group but it is a general record or a
1957 	 * delete-on-disk, it does not improve our connectivity (return 0),
1958 	 * and if the target inode is not trying to destroy itself we can't
1959 	 * allow the operation yet anyway (the second return -1).
1960 	 */
1961 	if (record->flush_state == HAMMER_FST_FLUSH) {
1962 		/*
1963 		 * If not in our flush group ask the parent to reflush
1964 		 * us as soon as possible.
1965 		 */
1966 		if (record->flush_group != flg) {
1967 			pip->flags |= HAMMER_INODE_REFLUSH;
1968 			record->target_ip->flags |= HAMMER_INODE_CONN_DOWN;
1969 			return(-1);
1970 		}
1971 
1972 		/*
1973 		 * If in our flush group everything is already set up,
1974 		 * just return whether the record will improve our
1975 		 * visibility or not.
1976 		 */
1977 		if (record->type == HAMMER_MEM_RECORD_ADD)
1978 			return(1);
1979 		return(0);
1980 	}
1981 
1982 	/*
1983 	 * It must be a setup record.  Try to resolve the setup dependancies
1984 	 * by recursing upwards so we can place ip on the flush list.
1985 	 *
1986 	 * Limit ourselves to 20 levels of recursion to avoid blowing out
1987 	 * the kernel stack.  If we hit the recursion limit we can't flush
1988 	 * until the parent flushes.  The parent will flush independantly
1989 	 * on its own and ultimately a deep recursion will be resolved.
1990 	 */
1991 	KKASSERT(record->flush_state == HAMMER_FST_SETUP);
1992 
1993 	good = hammer_setup_parent_inodes(pip, depth + 1, flg);
1994 
1995 	/*
1996 	 * If good < 0 the parent has no connectivity and we cannot safely
1997 	 * flush the directory entry, which also means we can't flush our
1998 	 * ip.  Flag us for downward recursion once the parent's
1999 	 * connectivity is resolved.  Flag the parent for [re]flush or it
2000 	 * may not check for downward recursions.
2001 	 */
2002 	if (good < 0) {
2003 		pip->flags |= HAMMER_INODE_REFLUSH;
2004 		record->target_ip->flags |= HAMMER_INODE_CONN_DOWN;
2005 		return(good);
2006 	}
2007 
2008 	/*
2009 	 * We are go, place the parent inode in a flushing state so we can
2010 	 * place its record in a flushing state.  Note that the parent
2011 	 * may already be flushing.  The record must be in the same flush
2012 	 * group as the parent.
2013 	 */
2014 	if (pip->flush_state != HAMMER_FST_FLUSH)
2015 		hammer_flush_inode_core(pip, flg, HAMMER_FLUSH_RECURSION);
2016 	KKASSERT(pip->flush_state == HAMMER_FST_FLUSH);
2017 
2018 	/*
2019 	 * It is possible for a rename to create a loop in the recursion
2020 	 * and revisit a record.  This will result in the record being
2021 	 * placed in a flush state unexpectedly.  This check deals with
2022 	 * the case.
2023 	 */
2024 	if (record->flush_state == HAMMER_FST_FLUSH) {
2025 		if (record->type == HAMMER_MEM_RECORD_ADD)
2026 			return(1);
2027 		return(0);
2028 	}
2029 
2030 	KKASSERT(record->flush_state == HAMMER_FST_SETUP);
2031 
2032 #if 0
2033 	if (record->type == HAMMER_MEM_RECORD_DEL &&
2034 	    (record->target_ip->flags & (HAMMER_INODE_DELETED|HAMMER_INODE_DELONDISK)) == 0) {
2035 		/*
2036 		 * Regardless of flushing state we cannot sync this path if the
2037 		 * record represents a delete-on-disk but the target inode
2038 		 * is not ready to sync its own deletion.
2039 		 *
2040 		 * XXX need to count effective nlinks to determine whether
2041 		 * the flush is ok, otherwise removing a hardlink will
2042 		 * just leave the DEL record to rot.
2043 		 */
2044 		record->target_ip->flags |= HAMMER_INODE_REFLUSH;
2045 		return(-1);
2046 	} else
2047 #endif
2048 	if (pip->flush_group == flg) {
2049 		/*
2050 		 * Because we have not calculated nlinks yet we can just
2051 		 * set records to the flush state if the parent is in
2052 		 * the same flush group as we are.
2053 		 */
2054 		record->flush_state = HAMMER_FST_FLUSH;
2055 		record->flush_group = flg;
2056 		++record->flush_group->refs;
2057 		hammer_ref(&record->lock);
2058 
2059 		/*
2060 		 * A general directory-add contributes to our visibility.
2061 		 *
2062 		 * Otherwise it is probably a directory-delete or
2063 		 * delete-on-disk record and does not contribute to our
2064 		 * visbility (but we can still flush it).
2065 		 */
2066 		if (record->type == HAMMER_MEM_RECORD_ADD)
2067 			return(1);
2068 		return(0);
2069 	} else {
2070 		/*
2071 		 * If the parent is not in our flush group we cannot
2072 		 * flush this record yet, there is no visibility.
2073 		 * We tell the parent to reflush and mark ourselves
2074 		 * so the parent knows it should flush us too.
2075 		 */
2076 		pip->flags |= HAMMER_INODE_REFLUSH;
2077 		record->target_ip->flags |= HAMMER_INODE_CONN_DOWN;
2078 		return(-1);
2079 	}
2080 }
2081 
2082 /*
2083  * This is the core routine placing an inode into the FST_FLUSH state.
2084  */
2085 static void
2086 hammer_flush_inode_core(hammer_inode_t ip, hammer_flush_group_t flg, int flags)
2087 {
2088 	hammer_mount_t hmp = ip->hmp;
2089 	int go_count;
2090 
2091 	/*
2092 	 * Set flush state and prevent the flusher from cycling into
2093 	 * the next flush group.  Do not place the ip on the list yet.
2094 	 * Inodes not in the idle state get an extra reference.
2095 	 */
2096 	KKASSERT(ip->flush_state != HAMMER_FST_FLUSH);
2097 	if (ip->flush_state == HAMMER_FST_IDLE)
2098 		hammer_ref(&ip->lock);
2099 	ip->flush_state = HAMMER_FST_FLUSH;
2100 	ip->flush_group = flg;
2101 	++hmp->flusher.group_lock;
2102 	++hmp->count_iqueued;
2103 	++hammer_count_iqueued;
2104 	++flg->total_count;
2105 	hammer_redo_fifo_start_flush(ip);
2106 
2107 #if 0
2108 	/*
2109 	 * We need to be able to vfsync/truncate from the backend.
2110 	 *
2111 	 * XXX Any truncation from the backend will acquire the vnode
2112 	 *     independently.
2113 	 */
2114 	KKASSERT((ip->flags & HAMMER_INODE_VHELD) == 0);
2115 	if (ip->vp && (ip->vp->v_flag & VINACTIVE) == 0) {
2116 		ip->flags |= HAMMER_INODE_VHELD;
2117 		vref(ip->vp);
2118 	}
2119 #endif
2120 
2121 	/*
2122 	 * Figure out how many in-memory records we can actually flush
2123 	 * (not including inode meta-data, buffers, etc).
2124 	 */
2125 	KKASSERT((ip->flags & HAMMER_INODE_WOULDBLOCK) == 0);
2126 	if (flags & HAMMER_FLUSH_RECURSION) {
2127 		/*
2128 		 * If this is a upwards recursion we do not want to
2129 		 * recurse down again!
2130 		 */
2131 		go_count = 1;
2132 #if 0
2133 	} else if (ip->flags & HAMMER_INODE_WOULDBLOCK) {
2134 		/*
2135 		 * No new records are added if we must complete a flush
2136 		 * from a previous cycle, but we do have to move the records
2137 		 * from the previous cycle to the current one.
2138 		 */
2139 #if 0
2140 		go_count = RB_SCAN(hammer_rec_rb_tree, &ip->rec_tree, NULL,
2141 				   hammer_syncgrp_child_callback, NULL);
2142 #endif
2143 		go_count = 1;
2144 #endif
2145 	} else {
2146 		/*
2147 		 * Normal flush, scan records and bring them into the flush.
2148 		 * Directory adds and deletes are usually skipped (they are
2149 		 * grouped with the related inode rather then with the
2150 		 * directory).
2151 		 *
2152 		 * go_count can be negative, which means the scan aborted
2153 		 * due to the flush group being over-full and we should
2154 		 * flush what we have.
2155 		 */
2156 		go_count = RB_SCAN(hammer_rec_rb_tree, &ip->rec_tree, NULL,
2157 				   hammer_setup_child_callback, NULL);
2158 	}
2159 
2160 	/*
2161 	 * This is a more involved test that includes go_count.  If we
2162 	 * can't flush, flag the inode and return.  If go_count is 0 we
2163 	 * were are unable to flush any records in our rec_tree and
2164 	 * must ignore the XDIRTY flag.
2165 	 */
2166 	if (go_count == 0) {
2167 		if ((ip->flags & HAMMER_INODE_MODMASK_NOXDIRTY) == 0) {
2168 			--hmp->count_iqueued;
2169 			--hammer_count_iqueued;
2170 
2171 			--flg->total_count;
2172 			ip->flush_state = HAMMER_FST_SETUP;
2173 			ip->flush_group = NULL;
2174 			if (flags & HAMMER_FLUSH_SIGNAL) {
2175 				ip->flags |= HAMMER_INODE_REFLUSH |
2176 					     HAMMER_INODE_RESIGNAL;
2177 			} else {
2178 				ip->flags |= HAMMER_INODE_REFLUSH;
2179 			}
2180 #if 0
2181 			if (ip->flags & HAMMER_INODE_VHELD) {
2182 				ip->flags &= ~HAMMER_INODE_VHELD;
2183 				vrele(ip->vp);
2184 			}
2185 #endif
2186 
2187 			/*
2188 			 * REFLUSH is needed to trigger dependancy wakeups
2189 			 * when an inode is in SETUP.
2190 			 */
2191 			ip->flags |= HAMMER_INODE_REFLUSH;
2192 			if (--hmp->flusher.group_lock == 0)
2193 				wakeup(&hmp->flusher.group_lock);
2194 			return;
2195 		}
2196 	}
2197 
2198 	/*
2199 	 * Snapshot the state of the inode for the backend flusher.
2200 	 *
2201 	 * We continue to retain save_trunc_off even when all truncations
2202 	 * have been resolved as an optimization to determine if we can
2203 	 * skip the B-Tree lookup for overwrite deletions.
2204 	 *
2205 	 * NOTE: The DELETING flag is a mod flag, but it is also sticky,
2206 	 * and stays in ip->flags.  Once set, it stays set until the
2207 	 * inode is destroyed.
2208 	 */
2209 	if (ip->flags & HAMMER_INODE_TRUNCATED) {
2210 		KKASSERT((ip->sync_flags & HAMMER_INODE_TRUNCATED) == 0);
2211 		ip->sync_trunc_off = ip->trunc_off;
2212 		ip->trunc_off = 0x7FFFFFFFFFFFFFFFLL;
2213 		ip->flags &= ~HAMMER_INODE_TRUNCATED;
2214 		ip->sync_flags |= HAMMER_INODE_TRUNCATED;
2215 
2216 		/*
2217 		 * The save_trunc_off used to cache whether the B-Tree
2218 		 * holds any records past that point is not used until
2219 		 * after the truncation has succeeded, so we can safely
2220 		 * set it now.
2221 		 */
2222 		if (ip->save_trunc_off > ip->sync_trunc_off)
2223 			ip->save_trunc_off = ip->sync_trunc_off;
2224 	}
2225 	ip->sync_flags |= (ip->flags & HAMMER_INODE_MODMASK &
2226 			   ~HAMMER_INODE_TRUNCATED);
2227 	ip->sync_ino_leaf = ip->ino_leaf;
2228 	ip->sync_ino_data = ip->ino_data;
2229 	ip->flags &= ~HAMMER_INODE_MODMASK | HAMMER_INODE_TRUNCATED;
2230 #ifdef DEBUG_TRUNCATE
2231 	if ((ip->sync_flags & HAMMER_INODE_TRUNCATED) && ip == HammerTruncIp)
2232 		hdkprintf("truncate %016llx\n", ip->sync_trunc_off);
2233 #endif
2234 
2235 	/*
2236 	 * The flusher list inherits our inode and reference.
2237 	 */
2238 	KKASSERT(flg->running == 0);
2239 	RB_INSERT(hammer_fls_rb_tree, &flg->flush_tree, ip);
2240 	if (--hmp->flusher.group_lock == 0)
2241 		wakeup(&hmp->flusher.group_lock);
2242 
2243 	/*
2244 	 * Auto-flush the group if it grows too large.  Make sure the
2245 	 * inode reclaim wait pipeline continues to work.
2246 	 */
2247 	if (flg->total_count >= hammer_autoflush ||
2248 	    flg->total_count >= hammer_limit_reclaims / 4) {
2249 		if (hmp->fill_flush_group == flg)
2250 			hmp->fill_flush_group = TAILQ_NEXT(flg, flush_entry);
2251 		hammer_flusher_async(hmp, flg);
2252 	}
2253 }
2254 
2255 /*
2256  * Callback for scan of ip->rec_tree.  Try to include each record in our
2257  * flush.  ip->flush_group has been set but the inode has not yet been
2258  * moved into a flushing state.
2259  *
2260  * If we get stuck on a record we have to set HAMMER_INODE_REFLUSH on
2261  * both inodes.
2262  *
2263  * We return 1 for any record placed or found in FST_FLUSH, which prevents
2264  * the caller from shortcutting the flush.
2265  */
2266 static int
2267 hammer_setup_child_callback(hammer_record_t rec, void *data)
2268 {
2269 	hammer_flush_group_t flg;
2270 	hammer_inode_t target_ip;
2271 	hammer_inode_t ip;
2272 	int r;
2273 
2274 	/*
2275 	 * Records deleted or committed by the backend are ignored.
2276 	 * Note that the flush detects deleted frontend records at
2277 	 * multiple points to deal with races.  This is just the first
2278 	 * line of defense.  The only time HAMMER_RECF_DELETED_FE cannot
2279 	 * be set is when HAMMER_RECF_INTERLOCK_BE is set, because it
2280 	 * messes up link-count calculations.
2281 	 *
2282 	 * NOTE: Don't get confused between record deletion and, say,
2283 	 * directory entry deletion.  The deletion of a directory entry
2284 	 * which is on-media has nothing to do with the record deletion
2285 	 * flags.
2286 	 */
2287 	if (rec->flags & (HAMMER_RECF_DELETED_FE | HAMMER_RECF_DELETED_BE |
2288 			  HAMMER_RECF_COMMITTED)) {
2289 		if (rec->flush_state == HAMMER_FST_FLUSH) {
2290 			KKASSERT(rec->flush_group == rec->ip->flush_group);
2291 			r = 1;
2292 		} else {
2293 			r = 0;
2294 		}
2295 		return(r);
2296 	}
2297 
2298 	/*
2299 	 * If the record is in an idle state it has no dependancies and
2300 	 * can be flushed.
2301 	 */
2302 	ip = rec->ip;
2303 	flg = ip->flush_group;
2304 	r = 0;
2305 
2306 	switch(rec->flush_state) {
2307 	case HAMMER_FST_IDLE:
2308 		/*
2309 		 * The record has no setup dependancy, we can flush it.
2310 		 */
2311 		KKASSERT(rec->target_ip == NULL);
2312 		rec->flush_state = HAMMER_FST_FLUSH;
2313 		rec->flush_group = flg;
2314 		++flg->refs;
2315 		hammer_ref(&rec->lock);
2316 		r = 1;
2317 		break;
2318 	case HAMMER_FST_SETUP:
2319 		/*
2320 		 * The record has a setup dependancy.  These are typically
2321 		 * directory entry adds and deletes.  Such entries will be
2322 		 * flushed when their inodes are flushed so we do not
2323 		 * usually have to add them to the flush here.  However,
2324 		 * if the target_ip has set HAMMER_INODE_CONN_DOWN then
2325 		 * it is asking us to flush this record (and it).
2326 		 */
2327 		target_ip = rec->target_ip;
2328 		KKASSERT(target_ip != NULL);
2329 		KKASSERT(target_ip->flush_state != HAMMER_FST_IDLE);
2330 
2331 		/*
2332 		 * If the target IP is already flushing in our group
2333 		 * we could associate the record, but target_ip has
2334 		 * already synced ino_data to sync_ino_data and we
2335 		 * would also have to adjust nlinks.   Plus there are
2336 		 * ordering issues for adds and deletes.
2337 		 *
2338 		 * Reflush downward if this is an ADD, and upward if
2339 		 * this is a DEL.
2340 		 */
2341 		if (target_ip->flush_state == HAMMER_FST_FLUSH) {
2342 			if (rec->type == HAMMER_MEM_RECORD_ADD)
2343 				ip->flags |= HAMMER_INODE_REFLUSH;
2344 			else
2345 				target_ip->flags |= HAMMER_INODE_REFLUSH;
2346 			break;
2347 		}
2348 
2349 		/*
2350 		 * Target IP is not yet flushing.  This can get complex
2351 		 * because we have to be careful about the recursion.
2352 		 *
2353 		 * Directories create an issue for us in that if a flush
2354 		 * of a directory is requested the expectation is to flush
2355 		 * any pending directory entries, but this will cause the
2356 		 * related inodes to recursively flush as well.  We can't
2357 		 * really defer the operation so just get as many as we
2358 		 * can and
2359 		 */
2360 #if 0
2361 		if ((target_ip->flags & HAMMER_INODE_RECLAIM) == 0 &&
2362 		    (target_ip->flags & HAMMER_INODE_CONN_DOWN) == 0) {
2363 			/*
2364 			 * We aren't reclaiming and the target ip was not
2365 			 * previously prevented from flushing due to this
2366 			 * record dependancy.  Do not flush this record.
2367 			 */
2368 			/*r = 0;*/
2369 		} else
2370 #endif
2371 		if (flg->total_count + flg->refs >
2372 			   ip->hmp->undo_rec_limit) {
2373 			/*
2374 			 * Our flush group is over-full and we risk blowing
2375 			 * out the UNDO FIFO.  Stop the scan, flush what we
2376 			 * have, then reflush the directory.
2377 			 *
2378 			 * The directory may be forced through multiple
2379 			 * flush groups before it can be completely
2380 			 * flushed.
2381 			 */
2382 			ip->flags |= HAMMER_INODE_RESIGNAL |
2383 				     HAMMER_INODE_REFLUSH;
2384 			r = -1;
2385 		} else if (rec->type == HAMMER_MEM_RECORD_ADD) {
2386 			/*
2387 			 * If the target IP is not flushing we can force
2388 			 * it to flush, even if it is unable to write out
2389 			 * any of its own records we have at least one in
2390 			 * hand that we CAN deal with.
2391 			 */
2392 			rec->flush_state = HAMMER_FST_FLUSH;
2393 			rec->flush_group = flg;
2394 			++flg->refs;
2395 			hammer_ref(&rec->lock);
2396 			hammer_flush_inode_core(target_ip, flg,
2397 						HAMMER_FLUSH_RECURSION);
2398 			r = 1;
2399 		} else {
2400 			/*
2401 			 * General or delete-on-disk record.
2402 			 *
2403 			 * XXX this needs help.  If a delete-on-disk we could
2404 			 * disconnect the target.  If the target has its own
2405 			 * dependancies they really need to be flushed.
2406 			 *
2407 			 * XXX
2408 			 */
2409 			rec->flush_state = HAMMER_FST_FLUSH;
2410 			rec->flush_group = flg;
2411 			++flg->refs;
2412 			hammer_ref(&rec->lock);
2413 			hammer_flush_inode_core(target_ip, flg,
2414 						HAMMER_FLUSH_RECURSION);
2415 			r = 1;
2416 		}
2417 		break;
2418 	case HAMMER_FST_FLUSH:
2419 		/*
2420 		 * The record could be part of a previous flush group if the
2421 		 * inode is a directory (the record being a directory entry).
2422 		 * Once the flush group was closed a hammer_test_inode()
2423 		 * function can cause a new flush group to be setup, placing
2424 		 * the directory inode itself in a new flush group.
2425 		 *
2426 		 * When associated with a previous flush group we count it
2427 		 * as if it were in our current flush group, since it will
2428 		 * effectively be flushed by the time we flush our current
2429 		 * flush group.
2430 		 */
2431 		KKASSERT(
2432 		    rec->ip->ino_data.obj_type == HAMMER_OBJTYPE_DIRECTORY ||
2433 		    rec->flush_group == flg);
2434 		r = 1;
2435 		break;
2436 	}
2437 	return(r);
2438 }
2439 
2440 #if 0
2441 /*
2442  * This version just moves records already in a flush state to the new
2443  * flush group and that is it.
2444  */
2445 static int
2446 hammer_syncgrp_child_callback(hammer_record_t rec, void *data)
2447 {
2448 	hammer_inode_t ip = rec->ip;
2449 
2450 	switch(rec->flush_state) {
2451 	case HAMMER_FST_FLUSH:
2452 		KKASSERT(rec->flush_group == ip->flush_group);
2453 		break;
2454 	default:
2455 		break;
2456 	}
2457 	return(0);
2458 }
2459 #endif
2460 
2461 /*
2462  * Wait for a previously queued flush to complete.
2463  *
2464  * If a critical error occured we don't try to wait.
2465  */
2466 void
2467 hammer_wait_inode(hammer_inode_t ip)
2468 {
2469 	/*
2470 	 * The inode can be in a SETUP state in which case RESIGNAL
2471 	 * should be set.  If RESIGNAL is not set then the previous
2472 	 * flush completed and a later operation placed the inode
2473 	 * in a passive setup state again, so we're done.
2474 	 *
2475 	 * The inode can be in a FLUSH state in which case we
2476 	 * can just wait for completion.
2477 	 */
2478 	while (ip->flush_state == HAMMER_FST_FLUSH ||
2479 	    (ip->flush_state == HAMMER_FST_SETUP &&
2480 	     (ip->flags & HAMMER_INODE_RESIGNAL))) {
2481 		/*
2482 		 * Don't try to flush on a critical error
2483 		 */
2484 		if (ip->hmp->flags & HAMMER_MOUNT_CRITICAL_ERROR)
2485 			break;
2486 
2487 		/*
2488 		 * If the inode was already being flushed its flg
2489 		 * may not have been queued to the backend.  We
2490 		 * have to make sure it gets queued or we can wind
2491 		 * up blocked or deadlocked (particularly if we are
2492 		 * the vnlru thread).
2493 		 */
2494 		if (ip->flush_state == HAMMER_FST_FLUSH) {
2495 			KKASSERT(ip->flush_group);
2496 			if (ip->flush_group->closed == 0) {
2497 				if (hammer_debug_inode) {
2498 					hkprintf("debug: forcing "
2499 						"async flush ip %016jx\n",
2500 						(intmax_t)ip->obj_id);
2501 				}
2502 				hammer_flusher_async(ip->hmp, ip->flush_group);
2503 				continue; /* retest */
2504 			}
2505 		}
2506 
2507 		/*
2508 		 * In a flush state with the flg queued to the backend
2509 		 * or in a setup state with RESIGNAL set, we can safely
2510 		 * wait.
2511 		 */
2512 		ip->flags |= HAMMER_INODE_FLUSHW;
2513 		tsleep(&ip->flags, 0, "hmrwin", 0);
2514 	}
2515 
2516 #if 0
2517 	/*
2518 	 * The inode may have been in a passive setup state,
2519 	 * call flush to make sure we get signaled.
2520 	 */
2521 	if (ip->flush_state == HAMMER_FST_SETUP)
2522 		hammer_flush_inode(ip, HAMMER_FLUSH_SIGNAL);
2523 #endif
2524 
2525 }
2526 
2527 /*
2528  * Called by the backend code when a flush has been completed.
2529  * The inode has already been removed from the flush list.
2530  *
2531  * A pipelined flush can occur, in which case we must re-enter the
2532  * inode on the list and re-copy its fields.
2533  */
2534 void
2535 hammer_flush_inode_done(hammer_inode_t ip, int error)
2536 {
2537 	hammer_mount_t hmp;
2538 	int dorel;
2539 
2540 	KKASSERT(ip->flush_state == HAMMER_FST_FLUSH);
2541 
2542 	hmp = ip->hmp;
2543 
2544 	/*
2545 	 * Auto-reflush if the backend could not completely flush
2546 	 * the inode.  This fixes a case where a deferred buffer flush
2547 	 * could cause fsync to return early.
2548 	 */
2549 	if (ip->sync_flags & HAMMER_INODE_MODMASK)
2550 		ip->flags |= HAMMER_INODE_REFLUSH;
2551 
2552 	/*
2553 	 * Merge left-over flags back into the frontend and fix the state.
2554 	 * Incomplete truncations are retained by the backend.
2555 	 */
2556 	ip->error = error;
2557 	ip->flags |= ip->sync_flags & ~HAMMER_INODE_TRUNCATED;
2558 	ip->sync_flags &= HAMMER_INODE_TRUNCATED;
2559 
2560 	/*
2561 	 * The backend may have adjusted nlinks, so if the adjusted nlinks
2562 	 * does not match the fronttend set the frontend's DDIRTY flag again.
2563 	 */
2564 	if (ip->ino_data.nlinks != ip->sync_ino_data.nlinks)
2565 		ip->flags |= HAMMER_INODE_DDIRTY;
2566 
2567 	/*
2568 	 * Fix up the dirty buffer status.
2569 	 */
2570 	if (ip->vp && RB_ROOT(&ip->vp->v_rbdirty_tree)) {
2571 		ip->flags |= HAMMER_INODE_BUFS;
2572 	}
2573 	hammer_redo_fifo_end_flush(ip);
2574 
2575 	/*
2576 	 * Re-set the XDIRTY flag if some of the inode's in-memory records
2577 	 * could not be flushed.
2578 	 */
2579 	KKASSERT((RB_EMPTY(&ip->rec_tree) &&
2580 		  (ip->flags & HAMMER_INODE_XDIRTY) == 0) ||
2581 		 (!RB_EMPTY(&ip->rec_tree) &&
2582 		  (ip->flags & HAMMER_INODE_XDIRTY) != 0));
2583 
2584 	/*
2585 	 * Do not lose track of inodes which no longer have vnode
2586 	 * assocations, otherwise they may never get flushed again.
2587 	 *
2588 	 * The reflush flag can be set superfluously, causing extra pain
2589 	 * for no reason.  If the inode is no longer modified it no longer
2590 	 * needs to be flushed.
2591 	 */
2592 	if (ip->flags & HAMMER_INODE_MODMASK) {
2593 		if (ip->vp == NULL)
2594 			ip->flags |= HAMMER_INODE_REFLUSH;
2595 	} else {
2596 		ip->flags &= ~HAMMER_INODE_REFLUSH;
2597 	}
2598 
2599 	/*
2600 	 * The fs token is held but the inode lock is not held.  Because this
2601 	 * is a backend flush it is possible that the vnode has no references
2602 	 * and cause a reclaim race inside vsetisdirty() if/when it blocks.
2603 	 *
2604 	 * Therefore, we must lock the inode around this particular dirtying
2605 	 * operation.  We don't have to around other dirtying operations
2606 	 * where the vnode is implicitly or explicitly held.
2607 	 */
2608 	if (ip->flags & HAMMER_INODE_MODMASK) {
2609 		hammer_lock_ex(&ip->lock);
2610 		hammer_inode_dirty(ip);
2611 		hammer_unlock(&ip->lock);
2612 	}
2613 
2614 	/*
2615 	 * Adjust the flush state.
2616 	 */
2617 	if (ip->flags & HAMMER_INODE_WOULDBLOCK) {
2618 		/*
2619 		 * We were unable to flush out all our records, leave the
2620 		 * inode in a flush state and in the current flush group.
2621 		 * The flush group will be re-run.
2622 		 *
2623 		 * This occurs if the UNDO block gets too full or there is
2624 		 * too much dirty meta-data and allows the flusher to
2625 		 * finalize the UNDO block and then re-flush.
2626 		 */
2627 		ip->flags &= ~HAMMER_INODE_WOULDBLOCK;
2628 		dorel = 0;
2629 	} else {
2630 		/*
2631 		 * Remove from the flush_group
2632 		 */
2633 		RB_REMOVE(hammer_fls_rb_tree, &ip->flush_group->flush_tree, ip);
2634 		ip->flush_group = NULL;
2635 
2636 #if 0
2637 		/*
2638 		 * Clean up the vnode ref and tracking counts.
2639 		 */
2640 		if (ip->flags & HAMMER_INODE_VHELD) {
2641 			ip->flags &= ~HAMMER_INODE_VHELD;
2642 			vrele(ip->vp);
2643 		}
2644 #endif
2645 		--hmp->count_iqueued;
2646 		--hammer_count_iqueued;
2647 
2648 		/*
2649 		 * And adjust the state.
2650 		 */
2651 		if (TAILQ_EMPTY(&ip->target_list) && RB_EMPTY(&ip->rec_tree)) {
2652 			ip->flush_state = HAMMER_FST_IDLE;
2653 			dorel = 1;
2654 		} else {
2655 			ip->flush_state = HAMMER_FST_SETUP;
2656 			dorel = 0;
2657 		}
2658 
2659 		/*
2660 		 * If the frontend is waiting for a flush to complete,
2661 		 * wake it up.
2662 		 */
2663 		if (ip->flags & HAMMER_INODE_FLUSHW) {
2664 			ip->flags &= ~HAMMER_INODE_FLUSHW;
2665 			wakeup(&ip->flags);
2666 		}
2667 
2668 		/*
2669 		 * If the frontend made more changes and requested another
2670 		 * flush, then try to get it running.
2671 		 *
2672 		 * Reflushes are aborted when the inode is errored out.
2673 		 */
2674 		if (ip->flags & HAMMER_INODE_REFLUSH) {
2675 			ip->flags &= ~HAMMER_INODE_REFLUSH;
2676 			if (ip->flags & HAMMER_INODE_RESIGNAL) {
2677 				ip->flags &= ~HAMMER_INODE_RESIGNAL;
2678 				hammer_flush_inode(ip, HAMMER_FLUSH_SIGNAL);
2679 			} else {
2680 				hammer_flush_inode(ip, 0);
2681 			}
2682 		}
2683 	}
2684 
2685 	/*
2686 	 * If we have no parent dependancies we can clear CONN_DOWN
2687 	 */
2688 	if (TAILQ_EMPTY(&ip->target_list))
2689 		ip->flags &= ~HAMMER_INODE_CONN_DOWN;
2690 
2691 	/*
2692 	 * If the inode is now clean drop the space reservation.
2693 	 */
2694 	if ((ip->flags & HAMMER_INODE_MODMASK) == 0 &&
2695 	    (ip->flags & HAMMER_INODE_RSV_INODES)) {
2696 		ip->flags &= ~HAMMER_INODE_RSV_INODES;
2697 		--hmp->rsv_inodes;
2698 	}
2699 
2700 	ip->flags &= ~HAMMER_INODE_SLAVEFLUSH;
2701 
2702 	if (dorel)
2703 		hammer_rel_inode(ip, 0);
2704 }
2705 
2706 /*
2707  * Called from hammer_sync_inode() to synchronize in-memory records
2708  * to the media.
2709  */
2710 static int
2711 hammer_sync_record_callback(hammer_record_t record, void *data)
2712 {
2713 	hammer_cursor_t cursor = data;
2714 	hammer_transaction_t trans = cursor->trans;
2715 	hammer_mount_t hmp = trans->hmp;
2716 	int error;
2717 
2718 	/*
2719 	 * Skip records that do not belong to the current flush.
2720 	 */
2721 	++hammer_stats_record_iterations;
2722 	if (record->flush_state != HAMMER_FST_FLUSH)
2723 		return(0);
2724 
2725 	if (record->flush_group != record->ip->flush_group) {
2726 		hdkprintf("rec %p ip %p bad flush group %p %p\n",
2727 			record,
2728 			record->ip,
2729 			record->flush_group,
2730 			record->ip->flush_group);
2731 		if (hammer_debug_critical)
2732 			Debugger("blah2");
2733 		return(0);
2734 	}
2735 	KKASSERT(record->flush_group == record->ip->flush_group);
2736 
2737 	/*
2738 	 * Interlock the record using the BE flag.  Once BE is set the
2739 	 * frontend cannot change the state of FE.
2740 	 *
2741 	 * NOTE: If FE is set prior to us setting BE we still sync the
2742 	 * record out, but the flush completion code converts it to
2743 	 * a delete-on-disk record instead of destroying it.
2744 	 */
2745 	KKASSERT((record->flags & HAMMER_RECF_INTERLOCK_BE) == 0);
2746 	record->flags |= HAMMER_RECF_INTERLOCK_BE;
2747 
2748 	/*
2749 	 * The backend has already disposed of the record.
2750 	 */
2751 	if (record->flags & (HAMMER_RECF_DELETED_BE | HAMMER_RECF_COMMITTED)) {
2752 		error = 0;
2753 		goto done;
2754 	}
2755 
2756 	/*
2757 	 * If the whole inode is being deleted and all on-disk records will
2758 	 * be deleted very soon, we can't sync any new records to disk
2759 	 * because they will be deleted in the same transaction they were
2760 	 * created in (delete_tid == create_tid), which will assert.
2761 	 *
2762 	 * XXX There may be a case with RECORD_ADD with DELETED_FE set
2763 	 * that we currently panic on.
2764 	 */
2765 	if (record->ip->sync_flags & HAMMER_INODE_DELETING) {
2766 		switch(record->type) {
2767 		case HAMMER_MEM_RECORD_DATA:
2768 			/*
2769 			 * We don't have to do anything, if the record was
2770 			 * committed the space will have been accounted for
2771 			 * in the blockmap.
2772 			 */
2773 			/* fall through */
2774 		case HAMMER_MEM_RECORD_GENERAL:
2775 			/*
2776 			 * Set deleted-by-backend flag.  Do not set the
2777 			 * backend committed flag, because we are throwing
2778 			 * the record away.
2779 			 */
2780 			record->flags |= HAMMER_RECF_DELETED_BE;
2781 			++record->ip->rec_generation;
2782 			error = 0;
2783 			goto done;
2784 		case HAMMER_MEM_RECORD_ADD:
2785 			hpanic("illegal add during inode deletion record %p",
2786 				record);
2787 			break; /* NOT REACHED */
2788 		case HAMMER_MEM_RECORD_INODE:
2789 			hpanic("attempt to sync inode record %p?", record);
2790 			break; /* NOT REACHED */
2791 		case HAMMER_MEM_RECORD_DEL:
2792 			/*
2793 			 * Follow through and issue the on-disk deletion
2794 			 */
2795 			break;
2796 		}
2797 	}
2798 
2799 	/*
2800 	 * If DELETED_FE is set special handling is needed for directory
2801 	 * entries.  Dependant pieces related to the directory entry may
2802 	 * have already been synced to disk.  If this occurs we have to
2803 	 * sync the directory entry and then change the in-memory record
2804 	 * from an ADD to a DELETE to cover the fact that it's been
2805 	 * deleted by the frontend.
2806 	 *
2807 	 * A directory delete covering record (MEM_RECORD_DEL) can never
2808 	 * be deleted by the frontend.
2809 	 *
2810 	 * Any other record type (aka DATA) can be deleted by the frontend.
2811 	 * XXX At the moment the flusher must skip it because there may
2812 	 * be another data record in the flush group for the same block,
2813 	 * meaning that some frontend data changes can leak into the backend's
2814 	 * synchronization point.
2815 	 */
2816 	if (record->flags & HAMMER_RECF_DELETED_FE) {
2817 		if (record->type == HAMMER_MEM_RECORD_ADD) {
2818 			/*
2819 			 * Convert a front-end deleted directory-add to
2820 			 * a directory-delete entry later.
2821 			 */
2822 			record->flags |= HAMMER_RECF_CONVERT_DELETE;
2823 		} else {
2824 			/*
2825 			 * Dispose of the record (race case).  Mark as
2826 			 * deleted by backend (and not committed).
2827 			 */
2828 			KKASSERT(record->type != HAMMER_MEM_RECORD_DEL);
2829 			record->flags |= HAMMER_RECF_DELETED_BE;
2830 			++record->ip->rec_generation;
2831 			error = 0;
2832 			goto done;
2833 		}
2834 	}
2835 
2836 	/*
2837 	 * Assign the create_tid for new records.  Deletions already
2838 	 * have the record's entire key properly set up.
2839 	 */
2840 	if (record->type != HAMMER_MEM_RECORD_DEL) {
2841 		record->leaf.base.create_tid = trans->tid;
2842 		record->leaf.create_ts = trans->time32;
2843 	}
2844 
2845 	/*
2846 	 * This actually moves the record to the on-media B-Tree.  We
2847 	 * must also generate REDO_TERM entries in the UNDO/REDO FIFO
2848 	 * indicating that the related REDO_WRITE(s) have been committed.
2849 	 *
2850 	 * During recovery any REDO_TERM's within the nominal recovery span
2851 	 * are ignored since the related meta-data is being undone, causing
2852 	 * any matching REDO_WRITEs to execute.  The REDO_TERMs outside
2853 	 * the nominal recovery span will match against REDO_WRITEs and
2854 	 * prevent them from being executed (because the meta-data has
2855 	 * already been synchronized).
2856 	 */
2857 	if (record->flags & HAMMER_RECF_REDO) {
2858 		KKASSERT(record->type == HAMMER_MEM_RECORD_DATA);
2859 		hammer_generate_redo(trans, record->ip,
2860 				     record->leaf.base.key -
2861 					 record->leaf.data_len,
2862 				     HAMMER_REDO_TERM_WRITE,
2863 				     NULL,
2864 				     record->leaf.data_len);
2865 	}
2866 
2867 	for (;;) {
2868 		error = hammer_ip_sync_record_cursor(cursor, record);
2869 		if (error != EDEADLK)
2870 			break;
2871 		hammer_done_cursor(cursor);
2872 		error = hammer_init_cursor(trans, cursor, &record->ip->cache[0],
2873 					   record->ip);
2874 		if (error)
2875 			break;
2876 	}
2877 	record->flags &= ~HAMMER_RECF_CONVERT_DELETE;
2878 
2879 	if (error)
2880 		error = -error;
2881 done:
2882 	hammer_flush_record_done(record, error);
2883 
2884 	/*
2885 	 * Do partial finalization if we have built up too many dirty
2886 	 * buffers.  Otherwise a buffer cache deadlock can occur when
2887 	 * doing things like creating tens of thousands of tiny files.
2888 	 *
2889 	 * We must release our cursor lock to avoid a 3-way deadlock
2890 	 * due to the exclusive sync lock the finalizer must get.
2891 	 *
2892 	 * WARNING: See warnings in hammer_unlock_cursor() function.
2893 	 */
2894         if (hammer_flusher_meta_limit(hmp) ||
2895 	    vm_page_count_severe()) {
2896 		hammer_unlock_cursor(cursor);
2897                 hammer_flusher_finalize(trans, 0);
2898 		hammer_lock_cursor(cursor);
2899 	}
2900 	return(error);
2901 }
2902 
2903 /*
2904  * Backend function called by the flusher to sync an inode to media.
2905  */
2906 int
2907 hammer_sync_inode(hammer_transaction_t trans, hammer_inode_t ip)
2908 {
2909 	struct hammer_cursor cursor;
2910 	hammer_node_t tmp_node;
2911 	hammer_record_t depend;
2912 	hammer_record_t next;
2913 	int error, tmp_error;
2914 	u_int64_t nlinks;
2915 
2916 	if ((ip->sync_flags & HAMMER_INODE_MODMASK) == 0)
2917 		return(0);
2918 
2919 	error = hammer_init_cursor(trans, &cursor, &ip->cache[1], ip);
2920 	if (error)
2921 		goto done;
2922 
2923 	/*
2924 	 * Any directory records referencing this inode which are not in
2925 	 * our current flush group must adjust our nlink count for the
2926 	 * purposes of synchronizating to disk.
2927 	 *
2928 	 * Records which are in our flush group can be unlinked from our
2929 	 * inode now, potentially allowing the inode to be physically
2930 	 * deleted.
2931 	 *
2932 	 * This cannot block.
2933 	 */
2934 	nlinks = ip->ino_data.nlinks;
2935 	next = TAILQ_FIRST(&ip->target_list);
2936 	while ((depend = next) != NULL) {
2937 		next = TAILQ_NEXT(depend, target_entry);
2938 		if (depend->flush_state == HAMMER_FST_FLUSH &&
2939 		    depend->flush_group == ip->flush_group) {
2940 			/*
2941 			 * If this is an ADD that was deleted by the frontend
2942 			 * the frontend nlinks count will have already been
2943 			 * decremented, but the backend is going to sync its
2944 			 * directory entry and must account for it.  The
2945 			 * record will be converted to a delete-on-disk when
2946 			 * it gets synced.
2947 			 *
2948 			 * If the ADD was not deleted by the frontend we
2949 			 * can remove the dependancy from our target_list.
2950 			 */
2951 			if (depend->flags & HAMMER_RECF_DELETED_FE) {
2952 				++nlinks;
2953 			} else {
2954 				TAILQ_REMOVE(&ip->target_list, depend,
2955 					     target_entry);
2956 				depend->target_ip = NULL;
2957 			}
2958 		} else if ((depend->flags & HAMMER_RECF_DELETED_FE) == 0) {
2959 			/*
2960 			 * Not part of our flush group and not deleted by
2961 			 * the front-end, adjust the link count synced to
2962 			 * the media (undo what the frontend did when it
2963 			 * queued the record).
2964 			 */
2965 			KKASSERT((depend->flags & HAMMER_RECF_DELETED_BE) == 0);
2966 			switch(depend->type) {
2967 			case HAMMER_MEM_RECORD_ADD:
2968 				--nlinks;
2969 				break;
2970 			case HAMMER_MEM_RECORD_DEL:
2971 				++nlinks;
2972 				break;
2973 			default:
2974 				break;
2975 			}
2976 		}
2977 	}
2978 
2979 	/*
2980 	 * Set dirty if we had to modify the link count.
2981 	 */
2982 	if (ip->sync_ino_data.nlinks != nlinks) {
2983 		KKASSERT((int64_t)nlinks >= 0);
2984 		ip->sync_ino_data.nlinks = nlinks;
2985 		ip->sync_flags |= HAMMER_INODE_DDIRTY;
2986 	}
2987 
2988 	/*
2989 	 * If there is a trunction queued destroy any data past the (aligned)
2990 	 * truncation point.  Userland will have dealt with the buffer
2991 	 * containing the truncation point for us.
2992 	 *
2993 	 * We don't flush pending frontend data buffers until after we've
2994 	 * dealt with the truncation.
2995 	 */
2996 	if (ip->sync_flags & HAMMER_INODE_TRUNCATED) {
2997 		/*
2998 		 * Interlock trunc_off.  The VOP front-end may continue to
2999 		 * make adjustments to it while we are blocked.
3000 		 */
3001 		off_t trunc_off;
3002 		off_t aligned_trunc_off;
3003 		int blkmask;
3004 
3005 		trunc_off = ip->sync_trunc_off;
3006 		blkmask = hammer_blocksize(trunc_off) - 1;
3007 		aligned_trunc_off = (trunc_off + blkmask) & ~(int64_t)blkmask;
3008 
3009 		/*
3010 		 * Delete any whole blocks on-media.  The front-end has
3011 		 * already cleaned out any partial block and made it
3012 		 * pending.  The front-end may have updated trunc_off
3013 		 * while we were blocked so we only use sync_trunc_off.
3014 		 *
3015 		 * This operation can blow out the buffer cache, EWOULDBLOCK
3016 		 * means we were unable to complete the deletion.  The
3017 		 * deletion will update sync_trunc_off in that case.
3018 		 */
3019 		error = hammer_ip_delete_range(&cursor, ip,
3020 						aligned_trunc_off,
3021 						0x7FFFFFFFFFFFFFFFLL, 2);
3022 		if (error == EWOULDBLOCK) {
3023 			ip->flags |= HAMMER_INODE_WOULDBLOCK;
3024 			error = 0;
3025 			goto defer_buffer_flush;
3026 		}
3027 
3028 		if (error)
3029 			goto done;
3030 
3031 		/*
3032 		 * Generate a REDO_TERM_TRUNC entry in the UNDO/REDO FIFO.
3033 		 *
3034 		 * XXX we do this even if we did not previously generate
3035 		 * a REDO_TRUNC record.  This operation may enclosed the
3036 		 * range for multiple prior truncation entries in the REDO
3037 		 * log.
3038 		 */
3039 		if (trans->hmp->version >= HAMMER_VOL_VERSION_FOUR &&
3040 		    (ip->flags & HAMMER_INODE_RDIRTY)) {
3041 			hammer_generate_redo(trans, ip, aligned_trunc_off,
3042 					     HAMMER_REDO_TERM_TRUNC,
3043 					     NULL, 0);
3044 		}
3045 
3046 		/*
3047 		 * Clear the truncation flag on the backend after we have
3048 		 * completed the deletions.  Backend data is now good again
3049 		 * (including new records we are about to sync, below).
3050 		 *
3051 		 * Leave sync_trunc_off intact.  As we write additional
3052 		 * records the backend will update sync_trunc_off.  This
3053 		 * tells the backend whether it can skip the overwrite
3054 		 * test.  This should work properly even when the backend
3055 		 * writes full blocks where the truncation point straddles
3056 		 * the block because the comparison is against the base
3057 		 * offset of the record.
3058 		 */
3059 		ip->sync_flags &= ~HAMMER_INODE_TRUNCATED;
3060 		/* ip->sync_trunc_off = 0x7FFFFFFFFFFFFFFFLL; */
3061 	} else {
3062 		error = 0;
3063 	}
3064 
3065 	/*
3066 	 * Now sync related records.  These will typically be directory
3067 	 * entries, records tracking direct-writes, or delete-on-disk records.
3068 	 */
3069 	if (error == 0) {
3070 		tmp_error = RB_SCAN(hammer_rec_rb_tree, &ip->rec_tree, NULL,
3071 				    hammer_sync_record_callback, &cursor);
3072 		if (tmp_error < 0)
3073 			tmp_error = -error;
3074 		if (tmp_error)
3075 			error = tmp_error;
3076 	}
3077 	hammer_cache_node(&ip->cache[1], cursor.node);
3078 
3079 	/*
3080 	 * Re-seek for inode update, assuming our cache hasn't been ripped
3081 	 * out from under us.
3082 	 */
3083 	if (error == 0) {
3084 		tmp_node = hammer_ref_node_safe(trans, &ip->cache[0], &error);
3085 		if (tmp_node) {
3086 			hammer_cursor_downgrade(&cursor);
3087 			hammer_lock_sh(&tmp_node->lock);
3088 			if ((tmp_node->flags & HAMMER_NODE_DELETED) == 0)
3089 				hammer_cursor_seek(&cursor, tmp_node, 0);
3090 			hammer_unlock(&tmp_node->lock);
3091 			hammer_rel_node(tmp_node);
3092 		}
3093 		error = 0;
3094 	}
3095 
3096 	/*
3097 	 * If we are deleting the inode the frontend had better not have
3098 	 * any active references on elements making up the inode.
3099 	 *
3100 	 * The call to hammer_ip_delete_clean() cleans up auxillary records
3101 	 * but not DB or DATA records.  Those must have already been deleted
3102 	 * by the normal truncation mechanic.
3103 	 */
3104 	if (error == 0 && ip->sync_ino_data.nlinks == 0 &&
3105 		RB_EMPTY(&ip->rec_tree)  &&
3106 	    (ip->sync_flags & HAMMER_INODE_DELETING) &&
3107 	    (ip->flags & HAMMER_INODE_DELETED) == 0) {
3108 		int count1 = 0;
3109 
3110 		error = hammer_ip_delete_clean(&cursor, ip, &count1);
3111 		if (error == 0) {
3112 			ip->flags |= HAMMER_INODE_DELETED;
3113 			ip->sync_flags &= ~HAMMER_INODE_DELETING;
3114 			ip->sync_flags &= ~HAMMER_INODE_TRUNCATED;
3115 			KKASSERT(RB_EMPTY(&ip->rec_tree));
3116 
3117 			/*
3118 			 * Set delete_tid in both the frontend and backend
3119 			 * copy of the inode record.  The DELETED flag handles
3120 			 * this, do not set DDIRTY.
3121 			 */
3122 			ip->ino_leaf.base.delete_tid = trans->tid;
3123 			ip->sync_ino_leaf.base.delete_tid = trans->tid;
3124 			ip->ino_leaf.delete_ts = trans->time32;
3125 			ip->sync_ino_leaf.delete_ts = trans->time32;
3126 
3127 
3128 			/*
3129 			 * Adjust the inode count in the volume header
3130 			 */
3131 			hammer_sync_lock_sh(trans);
3132 			if (ip->flags & HAMMER_INODE_ONDISK) {
3133 				hammer_modify_volume_field(trans,
3134 							   trans->rootvol,
3135 							   vol0_stat_inodes);
3136 				--ip->hmp->rootvol->ondisk->vol0_stat_inodes;
3137 				hammer_modify_volume_done(trans->rootvol);
3138 			}
3139 			hammer_sync_unlock(trans);
3140 		}
3141 	}
3142 
3143 	if (error)
3144 		goto done;
3145 	ip->sync_flags &= ~HAMMER_INODE_BUFS;
3146 
3147 defer_buffer_flush:
3148 	/*
3149 	 * Now update the inode's on-disk inode-data and/or on-disk record.
3150 	 * DELETED and ONDISK are managed only in ip->flags.
3151 	 *
3152 	 * In the case of a defered buffer flush we still update the on-disk
3153 	 * inode to satisfy visibility requirements if there happen to be
3154 	 * directory dependancies.
3155 	 */
3156 	switch(ip->flags & (HAMMER_INODE_DELETED | HAMMER_INODE_ONDISK)) {
3157 	case HAMMER_INODE_DELETED|HAMMER_INODE_ONDISK:
3158 		/*
3159 		 * If deleted and on-disk, don't set any additional flags.
3160 		 * the delete flag takes care of things.
3161 		 *
3162 		 * Clear flags which may have been set by the frontend.
3163 		 */
3164 		ip->sync_flags &= ~(HAMMER_INODE_DDIRTY | HAMMER_INODE_XDIRTY |
3165 				    HAMMER_INODE_SDIRTY |
3166 				    HAMMER_INODE_ATIME | HAMMER_INODE_MTIME |
3167 				    HAMMER_INODE_DELETING);
3168 		break;
3169 	case HAMMER_INODE_DELETED:
3170 		/*
3171 		 * Take care of the case where a deleted inode was never
3172 		 * flushed to the disk in the first place.
3173 		 *
3174 		 * Clear flags which may have been set by the frontend.
3175 		 */
3176 		ip->sync_flags &= ~(HAMMER_INODE_DDIRTY | HAMMER_INODE_XDIRTY |
3177 				    HAMMER_INODE_SDIRTY |
3178 				    HAMMER_INODE_ATIME | HAMMER_INODE_MTIME |
3179 				    HAMMER_INODE_DELETING);
3180 		while (RB_ROOT(&ip->rec_tree)) {
3181 			hammer_record_t record = RB_ROOT(&ip->rec_tree);
3182 			hammer_ref(&record->lock);
3183 			KKASSERT(hammer_oneref(&record->lock));
3184 			record->flags |= HAMMER_RECF_DELETED_BE;
3185 			++record->ip->rec_generation;
3186 			hammer_rel_mem_record(record);
3187 		}
3188 		break;
3189 	case HAMMER_INODE_ONDISK:
3190 		/*
3191 		 * If already on-disk, do not set any additional flags.
3192 		 */
3193 		break;
3194 	default:
3195 		/*
3196 		 * If not on-disk and not deleted, set DDIRTY to force
3197 		 * an initial record to be written.
3198 		 *
3199 		 * Also set the create_tid in both the frontend and backend
3200 		 * copy of the inode record.
3201 		 */
3202 		ip->ino_leaf.base.create_tid = trans->tid;
3203 		ip->ino_leaf.create_ts = trans->time32;
3204 		ip->sync_ino_leaf.base.create_tid = trans->tid;
3205 		ip->sync_ino_leaf.create_ts = trans->time32;
3206 		ip->sync_flags |= HAMMER_INODE_DDIRTY;
3207 		break;
3208 	}
3209 
3210 	/*
3211 	 * If DDIRTY or SDIRTY is set, write out a new record.
3212 	 * If the inode is already on-disk the old record is marked as
3213 	 * deleted.
3214 	 *
3215 	 * If DELETED is set hammer_update_inode() will delete the existing
3216 	 * record without writing out a new one.
3217 	 *
3218 	 * If *ONLY* the ITIMES flag is set we can update the record in-place.
3219 	 */
3220 	if (ip->flags & HAMMER_INODE_DELETED) {
3221 		error = hammer_update_inode(&cursor, ip);
3222 	} else
3223 	if (!(ip->sync_flags & (HAMMER_INODE_DDIRTY | HAMMER_INODE_SDIRTY)) &&
3224 	    (ip->sync_flags & (HAMMER_INODE_ATIME | HAMMER_INODE_MTIME))) {
3225 		error = hammer_update_itimes(&cursor, ip);
3226 	} else
3227 	if (ip->sync_flags & (HAMMER_INODE_DDIRTY | HAMMER_INODE_SDIRTY |
3228 			      HAMMER_INODE_ATIME | HAMMER_INODE_MTIME)) {
3229 		error = hammer_update_inode(&cursor, ip);
3230 	}
3231 done:
3232 	if (ip->flags & HAMMER_INODE_MODMASK)
3233 		hammer_inode_dirty(ip);
3234 	if (error) {
3235 		hammer_critical_error(ip->hmp, ip, error,
3236 				      "while syncing inode");
3237 	}
3238 	hammer_done_cursor(&cursor);
3239 	return(error);
3240 }
3241 
3242 /*
3243  * This routine is called when the OS is no longer actively referencing
3244  * the inode (but might still be keeping it cached), or when releasing
3245  * the last reference to an inode.
3246  *
3247  * At this point if the inode's nlinks count is zero we want to destroy
3248  * it, which may mean destroying it on-media too.
3249  */
3250 void
3251 hammer_inode_unloadable_check(hammer_inode_t ip, int getvp)
3252 {
3253 	struct vnode *vp;
3254 
3255 	/*
3256 	 * Set the DELETING flag when the link count drops to 0 and the
3257 	 * OS no longer has any opens on the inode.
3258 	 *
3259 	 * The backend will clear DELETING (a mod flag) and set DELETED
3260 	 * (a state flag) when it is actually able to perform the
3261 	 * operation.
3262 	 *
3263 	 * Don't reflag the deletion if the flusher is currently syncing
3264 	 * one that was already flagged.  A previously set DELETING flag
3265 	 * may bounce around flags and sync_flags until the operation is
3266 	 * completely done.
3267 	 *
3268 	 * Do not attempt to modify a snapshot inode (one set to read-only).
3269 	 */
3270 	if (ip->ino_data.nlinks == 0 &&
3271 	    ((ip->flags | ip->sync_flags) & (HAMMER_INODE_RO|HAMMER_INODE_DELETING|HAMMER_INODE_DELETED)) == 0) {
3272 		ip->flags |= HAMMER_INODE_DELETING;
3273 		ip->flags |= HAMMER_INODE_TRUNCATED;
3274 		ip->trunc_off = 0;
3275 		vp = NULL;
3276 		if (getvp) {
3277 			if (hammer_get_vnode(ip, &vp) != 0)
3278 				return;
3279 		}
3280 
3281 		/*
3282 		 * Final cleanup
3283 		 */
3284 		if (ip->vp)
3285 			nvtruncbuf(ip->vp, 0, HAMMER_BUFSIZE, 0, 0);
3286 		if (ip->flags & HAMMER_INODE_MODMASK)
3287 			hammer_inode_dirty(ip);
3288 		if (getvp)
3289 			vput(vp);
3290 	}
3291 }
3292 
3293 /*
3294  * After potentially resolving a dependancy the inode is tested
3295  * to determine whether it needs to be reflushed.
3296  */
3297 void
3298 hammer_test_inode(hammer_inode_t ip)
3299 {
3300 	if (ip->flags & HAMMER_INODE_REFLUSH) {
3301 		ip->flags &= ~HAMMER_INODE_REFLUSH;
3302 		hammer_ref(&ip->lock);
3303 		if (ip->flags & HAMMER_INODE_RESIGNAL) {
3304 			ip->flags &= ~HAMMER_INODE_RESIGNAL;
3305 			hammer_flush_inode(ip, HAMMER_FLUSH_SIGNAL);
3306 		} else {
3307 			hammer_flush_inode(ip, 0);
3308 		}
3309 		hammer_rel_inode(ip, 0);
3310 	}
3311 }
3312 
3313 /*
3314  * Clear the RECLAIM flag on an inode.  This occurs when the inode is
3315  * reassociated with a vp or just before it gets freed.
3316  *
3317  * Pipeline wakeups to threads blocked due to an excessive number of
3318  * detached inodes.  This typically occurs when atime updates accumulate
3319  * while scanning a directory tree.
3320  */
3321 static void
3322 hammer_inode_wakereclaims(hammer_inode_t ip)
3323 {
3324 	struct hammer_reclaim *reclaim;
3325 	hammer_mount_t hmp = ip->hmp;
3326 
3327 	if ((ip->flags & HAMMER_INODE_RECLAIM) == 0)
3328 		return;
3329 
3330 	--hammer_count_reclaims;
3331 	--hmp->count_reclaims;
3332 	ip->flags &= ~HAMMER_INODE_RECLAIM;
3333 
3334 	if ((reclaim = TAILQ_FIRST(&hmp->reclaim_list)) != NULL) {
3335 		KKASSERT(reclaim->count > 0);
3336 		if (--reclaim->count == 0) {
3337 			TAILQ_REMOVE(&hmp->reclaim_list, reclaim, entry);
3338 			wakeup(reclaim);
3339 		}
3340 	}
3341 }
3342 
3343 /*
3344  * Setup our reclaim pipeline.  We only let so many detached (and dirty)
3345  * inodes build up before we start blocking.  This routine is called
3346  * if a new inode is created or an inode is loaded from media.
3347  *
3348  * When we block we don't care *which* inode has finished reclaiming,
3349  * as long as one does.
3350  *
3351  * The reclaim pipeline is primarily governed by the auto-flush which is
3352  * 1/4 hammer_limit_reclaims.  We don't want to block if the count is
3353  * less than 1/2 hammer_limit_reclaims.  From 1/2 to full count is
3354  * dynamically governed.
3355  */
3356 void
3357 hammer_inode_waitreclaims(hammer_transaction_t trans)
3358 {
3359 	hammer_mount_t hmp = trans->hmp;
3360 	struct hammer_reclaim reclaim;
3361 	int lower_limit;
3362 
3363 	/*
3364 	 * Track inode load, delay if the number of reclaiming inodes is
3365 	 * between 2/4 and 4/4 hammer_limit_reclaims, depending.
3366 	 */
3367 	if (curthread->td_proc) {
3368 		struct hammer_inostats *stats;
3369 
3370 		stats = hammer_inode_inostats(hmp, curthread->td_proc->p_pid);
3371 		++stats->count;
3372 
3373 		if (stats->count > hammer_limit_reclaims / 2)
3374 			stats->count = hammer_limit_reclaims / 2;
3375 		lower_limit = hammer_limit_reclaims - stats->count;
3376 		if (hammer_debug_general & 0x10000) {
3377 			hdkprintf("pid %5d limit %d\n",
3378 				(int)curthread->td_proc->p_pid, lower_limit);
3379 		}
3380 	} else {
3381 		lower_limit = hammer_limit_reclaims * 3 / 4;
3382 	}
3383 	if (hmp->count_reclaims >= lower_limit) {
3384 		reclaim.count = 1;
3385 		TAILQ_INSERT_TAIL(&hmp->reclaim_list, &reclaim, entry);
3386 		tsleep(&reclaim, 0, "hmrrcm", hz);
3387 		if (reclaim.count > 0)
3388 			TAILQ_REMOVE(&hmp->reclaim_list, &reclaim, entry);
3389 	}
3390 }
3391 
3392 /*
3393  * Keep track of reclaim statistics on a per-pid basis using a loose
3394  * 4-way set associative hash table.  Collisions inherit the count of
3395  * the previous entry.
3396  *
3397  * NOTE: We want to be careful here to limit the chain size.  If the chain
3398  *	 size is too large a pid will spread its stats out over too many
3399  *	 entries under certain types of heavy filesystem activity and
3400  *	 wind up not delaying long enough.
3401  */
3402 static
3403 struct hammer_inostats *
3404 hammer_inode_inostats(hammer_mount_t hmp, pid_t pid)
3405 {
3406 	struct hammer_inostats *stats;
3407 	int delta;
3408 	int chain;
3409 	static volatile int iterator;	/* we don't care about MP races */
3410 
3411 	/*
3412 	 * Chain up to 4 times to find our entry.
3413 	 */
3414 	for (chain = 0; chain < 4; ++chain) {
3415 		stats = &hmp->inostats[(pid + chain) & HAMMER_INOSTATS_HMASK];
3416 		if (stats->pid == pid)
3417 			break;
3418 	}
3419 
3420 	/*
3421 	 * Replace one of the four chaining entries with our new entry.
3422 	 */
3423 	if (chain == 4) {
3424 		stats = &hmp->inostats[(pid + (iterator++ & 3)) &
3425 				       HAMMER_INOSTATS_HMASK];
3426 		stats->pid = pid;
3427 	}
3428 
3429 	/*
3430 	 * Decay the entry
3431 	 */
3432 	if (stats->count && stats->ltick != ticks) {
3433 		delta = ticks - stats->ltick;
3434 		stats->ltick = ticks;
3435 		if (delta <= 0 || delta > hz * 60)
3436 			stats->count = 0;
3437 		else
3438 			stats->count = stats->count * hz / (hz + delta);
3439 	}
3440 	if (hammer_debug_general & 0x10000)
3441 		hdkprintf("pid %5d stats %d\n", (int)pid, stats->count);
3442 	return (stats);
3443 }
3444 
3445 #if 0
3446 
3447 /*
3448  * XXX not used, doesn't work very well due to the large batching nature
3449  * of flushes.
3450  *
3451  * A larger then normal backlog of inodes is sitting in the flusher,
3452  * enforce a general slowdown to let it catch up.  This routine is only
3453  * called on completion of a non-flusher-related transaction which
3454  * performed B-Tree node I/O.
3455  *
3456  * It is possible for the flusher to stall in a continuous load.
3457  * blogbench -i1000 -o seems to do a good job generating this sort of load.
3458  * If the flusher is unable to catch up the inode count can bloat until
3459  * we run out of kvm.
3460  *
3461  * This is a bit of a hack.
3462  */
3463 void
3464 hammer_inode_waithard(hammer_mount_t hmp)
3465 {
3466 	/*
3467 	 * Hysteresis.
3468 	 */
3469 	if (hmp->flags & HAMMER_MOUNT_FLUSH_RECOVERY) {
3470 		if (hmp->count_reclaims < hammer_limit_reclaims / 2 &&
3471 		    hmp->count_iqueued < hmp->count_inodes / 20) {
3472 			hmp->flags &= ~HAMMER_MOUNT_FLUSH_RECOVERY;
3473 			return;
3474 		}
3475 	} else {
3476 		if (hmp->count_reclaims < hammer_limit_reclaims ||
3477 		    hmp->count_iqueued < hmp->count_inodes / 10) {
3478 			return;
3479 		}
3480 		hmp->flags |= HAMMER_MOUNT_FLUSH_RECOVERY;
3481 	}
3482 
3483 	/*
3484 	 * Block for one flush cycle.
3485 	 */
3486 	hammer_flusher_wait_next(hmp);
3487 }
3488 
3489 #endif
3490