xref: /dragonfly/sys/vfs/hammer/hammer_inode.c (revision 6e278935)
1 /*
2  * Copyright (c) 2007-2008 The DragonFly Project.  All rights reserved.
3  *
4  * This code is derived from software contributed to The DragonFly Project
5  * by Matthew Dillon <dillon@backplane.com>
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  *
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in
15  *    the documentation and/or other materials provided with the
16  *    distribution.
17  * 3. Neither the name of The DragonFly Project nor the names of its
18  *    contributors may be used to endorse or promote products derived
19  *    from this software without specific, prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  * $DragonFly: src/sys/vfs/hammer/hammer_inode.c,v 1.114 2008/09/24 00:53:51 dillon Exp $
35  */
36 
37 #include "hammer.h"
38 #include <vm/vm_extern.h>
39 
40 static int	hammer_unload_inode(struct hammer_inode *ip);
41 static void	hammer_free_inode(hammer_inode_t ip);
42 static void	hammer_flush_inode_core(hammer_inode_t ip,
43 					hammer_flush_group_t flg, int flags);
44 static int	hammer_setup_child_callback(hammer_record_t rec, void *data);
45 #if 0
46 static int	hammer_syncgrp_child_callback(hammer_record_t rec, void *data);
47 #endif
48 static int	hammer_setup_parent_inodes(hammer_inode_t ip, int depth,
49 					hammer_flush_group_t flg);
50 static int	hammer_setup_parent_inodes_helper(hammer_record_t record,
51 					int depth, hammer_flush_group_t flg);
52 static void	hammer_inode_wakereclaims(hammer_inode_t ip);
53 static struct hammer_inostats *hammer_inode_inostats(hammer_mount_t hmp,
54 					pid_t pid);
55 
56 #ifdef DEBUG_TRUNCATE
57 extern struct hammer_inode *HammerTruncIp;
58 #endif
59 
60 /*
61  * RB-Tree support for inode structures
62  */
63 int
64 hammer_ino_rb_compare(hammer_inode_t ip1, hammer_inode_t ip2)
65 {
66 	if (ip1->obj_localization < ip2->obj_localization)
67 		return(-1);
68 	if (ip1->obj_localization > ip2->obj_localization)
69 		return(1);
70 	if (ip1->obj_id < ip2->obj_id)
71 		return(-1);
72 	if (ip1->obj_id > ip2->obj_id)
73 		return(1);
74 	if (ip1->obj_asof < ip2->obj_asof)
75 		return(-1);
76 	if (ip1->obj_asof > ip2->obj_asof)
77 		return(1);
78 	return(0);
79 }
80 
81 int
82 hammer_redo_rb_compare(hammer_inode_t ip1, hammer_inode_t ip2)
83 {
84 	if (ip1->redo_fifo_start < ip2->redo_fifo_start)
85 		return(-1);
86 	if (ip1->redo_fifo_start > ip2->redo_fifo_start)
87 		return(1);
88 	return(0);
89 }
90 
91 /*
92  * RB-Tree support for inode structures / special LOOKUP_INFO
93  */
94 static int
95 hammer_inode_info_cmp(hammer_inode_info_t info, hammer_inode_t ip)
96 {
97 	if (info->obj_localization < ip->obj_localization)
98 		return(-1);
99 	if (info->obj_localization > ip->obj_localization)
100 		return(1);
101 	if (info->obj_id < ip->obj_id)
102 		return(-1);
103 	if (info->obj_id > ip->obj_id)
104 		return(1);
105 	if (info->obj_asof < ip->obj_asof)
106 		return(-1);
107 	if (info->obj_asof > ip->obj_asof)
108 		return(1);
109 	return(0);
110 }
111 
112 /*
113  * Used by hammer_scan_inode_snapshots() to locate all of an object's
114  * snapshots.  Note that the asof field is not tested, which we can get
115  * away with because it is the lowest-priority field.
116  */
117 static int
118 hammer_inode_info_cmp_all_history(hammer_inode_t ip, void *data)
119 {
120 	hammer_inode_info_t info = data;
121 
122 	if (ip->obj_localization > info->obj_localization)
123 		return(1);
124 	if (ip->obj_localization < info->obj_localization)
125 		return(-1);
126 	if (ip->obj_id > info->obj_id)
127 		return(1);
128 	if (ip->obj_id < info->obj_id)
129 		return(-1);
130 	return(0);
131 }
132 
133 /*
134  * Used by hammer_unload_pseudofs() to locate all inodes associated with
135  * a particular PFS.
136  */
137 static int
138 hammer_inode_pfs_cmp(hammer_inode_t ip, void *data)
139 {
140 	u_int32_t localization = *(u_int32_t *)data;
141 	if (ip->obj_localization > localization)
142 		return(1);
143 	if (ip->obj_localization < localization)
144 		return(-1);
145 	return(0);
146 }
147 
148 /*
149  * RB-Tree support for pseudofs structures
150  */
151 static int
152 hammer_pfs_rb_compare(hammer_pseudofs_inmem_t p1, hammer_pseudofs_inmem_t p2)
153 {
154 	if (p1->localization < p2->localization)
155 		return(-1);
156 	if (p1->localization > p2->localization)
157 		return(1);
158 	return(0);
159 }
160 
161 
162 RB_GENERATE(hammer_ino_rb_tree, hammer_inode, rb_node, hammer_ino_rb_compare);
163 RB_GENERATE_XLOOKUP(hammer_ino_rb_tree, INFO, hammer_inode, rb_node,
164 		hammer_inode_info_cmp, hammer_inode_info_t);
165 RB_GENERATE2(hammer_pfs_rb_tree, hammer_pseudofs_inmem, rb_node,
166              hammer_pfs_rb_compare, u_int32_t, localization);
167 
168 /*
169  * The kernel is not actively referencing this vnode but is still holding
170  * it cached.
171  *
172  * This is called from the frontend.
173  *
174  * MPALMOSTSAFE
175  */
176 int
177 hammer_vop_inactive(struct vop_inactive_args *ap)
178 {
179 	struct hammer_inode *ip = VTOI(ap->a_vp);
180 	hammer_mount_t hmp;
181 
182 	/*
183 	 * Degenerate case
184 	 */
185 	if (ip == NULL) {
186 		vrecycle(ap->a_vp);
187 		return(0);
188 	}
189 
190 	/*
191 	 * If the inode no longer has visibility in the filesystem try to
192 	 * recycle it immediately, even if the inode is dirty.  Recycling
193 	 * it quickly allows the system to reclaim buffer cache and VM
194 	 * resources which can matter a lot in a heavily loaded system.
195 	 *
196 	 * This can deadlock in vfsync() if we aren't careful.
197 	 *
198 	 * Do not queue the inode to the flusher if we still have visibility,
199 	 * otherwise namespace calls such as chmod will unnecessarily generate
200 	 * multiple inode updates.
201 	 */
202 	if (ip->ino_data.nlinks == 0) {
203 		hmp = ip->hmp;
204 		lwkt_gettoken(&hmp->fs_token);
205 		hammer_inode_unloadable_check(ip, 0);
206 		if (ip->flags & HAMMER_INODE_MODMASK)
207 			hammer_flush_inode(ip, 0);
208 		lwkt_reltoken(&hmp->fs_token);
209 		vrecycle(ap->a_vp);
210 	}
211 	return(0);
212 }
213 
214 /*
215  * Release the vnode association.  This is typically (but not always)
216  * the last reference on the inode.
217  *
218  * Once the association is lost we are on our own with regards to
219  * flushing the inode.
220  *
221  * We must interlock ip->vp so hammer_get_vnode() can avoid races.
222  */
223 int
224 hammer_vop_reclaim(struct vop_reclaim_args *ap)
225 {
226 	struct hammer_inode *ip;
227 	hammer_mount_t hmp;
228 	struct vnode *vp;
229 
230 	vp = ap->a_vp;
231 
232 	if ((ip = vp->v_data) != NULL) {
233 		hmp = ip->hmp;
234 		lwkt_gettoken(&hmp->fs_token);
235 		hammer_lock_ex(&ip->lock);
236 		vp->v_data = NULL;
237 		ip->vp = NULL;
238 
239 		if ((ip->flags & HAMMER_INODE_RECLAIM) == 0) {
240 			++hammer_count_reclaims;
241 			++hmp->count_reclaims;
242 			ip->flags |= HAMMER_INODE_RECLAIM;
243 		}
244 		hammer_unlock(&ip->lock);
245 		hammer_rel_inode(ip, 1);
246 		lwkt_reltoken(&hmp->fs_token);
247 	}
248 	return(0);
249 }
250 
251 /*
252  * Return a locked vnode for the specified inode.  The inode must be
253  * referenced but NOT LOCKED on entry and will remain referenced on
254  * return.
255  *
256  * Called from the frontend.
257  */
258 int
259 hammer_get_vnode(struct hammer_inode *ip, struct vnode **vpp)
260 {
261 	hammer_mount_t hmp;
262 	struct vnode *vp;
263 	int error = 0;
264 	u_int8_t obj_type;
265 
266 	hmp = ip->hmp;
267 
268 	for (;;) {
269 		if ((vp = ip->vp) == NULL) {
270 			error = getnewvnode(VT_HAMMER, hmp->mp, vpp, 0, 0);
271 			if (error)
272 				break;
273 			hammer_lock_ex(&ip->lock);
274 			if (ip->vp != NULL) {
275 				hammer_unlock(&ip->lock);
276 				vp = *vpp;
277 				vp->v_type = VBAD;
278 				vx_put(vp);
279 				continue;
280 			}
281 			hammer_ref(&ip->lock);
282 			vp = *vpp;
283 			ip->vp = vp;
284 
285 			obj_type = ip->ino_data.obj_type;
286 			vp->v_type = hammer_get_vnode_type(obj_type);
287 
288 			hammer_inode_wakereclaims(ip);
289 
290 			switch(ip->ino_data.obj_type) {
291 			case HAMMER_OBJTYPE_CDEV:
292 			case HAMMER_OBJTYPE_BDEV:
293 				vp->v_ops = &hmp->mp->mnt_vn_spec_ops;
294 				addaliasu(vp, ip->ino_data.rmajor,
295 					  ip->ino_data.rminor);
296 				break;
297 			case HAMMER_OBJTYPE_FIFO:
298 				vp->v_ops = &hmp->mp->mnt_vn_fifo_ops;
299 				break;
300 			case HAMMER_OBJTYPE_REGFILE:
301 				break;
302 			default:
303 				break;
304 			}
305 
306 			/*
307 			 * Only mark as the root vnode if the ip is not
308 			 * historical, otherwise the VFS cache will get
309 			 * confused.  The other half of the special handling
310 			 * is in hammer_vop_nlookupdotdot().
311 			 *
312 			 * Pseudo-filesystem roots can be accessed via
313 			 * non-root filesystem paths and setting VROOT may
314 			 * confuse the namecache.  Set VPFSROOT instead.
315 			 */
316 			if (ip->obj_id == HAMMER_OBJID_ROOT &&
317 			    ip->obj_asof == hmp->asof) {
318 				if (ip->obj_localization == 0)
319 					vsetflags(vp, VROOT);
320 				else
321 					vsetflags(vp, VPFSROOT);
322 			}
323 
324 			vp->v_data = (void *)ip;
325 			/* vnode locked by getnewvnode() */
326 			/* make related vnode dirty if inode dirty? */
327 			hammer_unlock(&ip->lock);
328 			if (vp->v_type == VREG) {
329 				vinitvmio(vp, ip->ino_data.size,
330 					  hammer_blocksize(ip->ino_data.size),
331 					  hammer_blockoff(ip->ino_data.size));
332 			}
333 			break;
334 		}
335 
336 		/*
337 		 * Interlock vnode clearing.  This does not prevent the
338 		 * vnode from going into a reclaimed state but it does
339 		 * prevent it from being destroyed or reused so the vget()
340 		 * will properly fail.
341 		 */
342 		hammer_lock_ex(&ip->lock);
343 		if ((vp = ip->vp) == NULL) {
344 			hammer_unlock(&ip->lock);
345 			continue;
346 		}
347 		vhold_interlocked(vp);
348 		hammer_unlock(&ip->lock);
349 
350 		/*
351 		 * loop if the vget fails (aka races), or if the vp
352 		 * no longer matches ip->vp.
353 		 */
354 		if (vget(vp, LK_EXCLUSIVE) == 0) {
355 			if (vp == ip->vp) {
356 				vdrop(vp);
357 				break;
358 			}
359 			vput(vp);
360 		}
361 		vdrop(vp);
362 	}
363 	*vpp = vp;
364 	return(error);
365 }
366 
367 /*
368  * Locate all copies of the inode for obj_id compatible with the specified
369  * asof, reference, and issue the related call-back.  This routine is used
370  * for direct-io invalidation and does not create any new inodes.
371  */
372 void
373 hammer_scan_inode_snapshots(hammer_mount_t hmp, hammer_inode_info_t iinfo,
374 		            int (*callback)(hammer_inode_t ip, void *data),
375 			    void *data)
376 {
377 	hammer_ino_rb_tree_RB_SCAN(&hmp->rb_inos_root,
378 				   hammer_inode_info_cmp_all_history,
379 				   callback, iinfo);
380 }
381 
382 /*
383  * Acquire a HAMMER inode.  The returned inode is not locked.  These functions
384  * do not attach or detach the related vnode (use hammer_get_vnode() for
385  * that).
386  *
387  * The flags argument is only applied for newly created inodes, and only
388  * certain flags are inherited.
389  *
390  * Called from the frontend.
391  */
392 struct hammer_inode *
393 hammer_get_inode(hammer_transaction_t trans, hammer_inode_t dip,
394 		 int64_t obj_id, hammer_tid_t asof, u_int32_t localization,
395 		 int flags, int *errorp)
396 {
397 	hammer_mount_t hmp = trans->hmp;
398 	struct hammer_node_cache *cachep;
399 	struct hammer_inode_info iinfo;
400 	struct hammer_cursor cursor;
401 	struct hammer_inode *ip;
402 
403 
404 	/*
405 	 * Determine if we already have an inode cached.  If we do then
406 	 * we are golden.
407 	 *
408 	 * If we find an inode with no vnode we have to mark the
409 	 * transaction such that hammer_inode_waitreclaims() is
410 	 * called later on to avoid building up an infinite number
411 	 * of inodes.  Otherwise we can continue to * add new inodes
412 	 * faster then they can be disposed of, even with the tsleep
413 	 * delay.
414 	 *
415 	 * If we find a dummy inode we return a failure so dounlink
416 	 * (which does another lookup) doesn't try to mess with the
417 	 * link count.  hammer_vop_nresolve() uses hammer_get_dummy_inode()
418 	 * to ref dummy inodes.
419 	 */
420 	iinfo.obj_id = obj_id;
421 	iinfo.obj_asof = asof;
422 	iinfo.obj_localization = localization;
423 loop:
424 	ip = hammer_ino_rb_tree_RB_LOOKUP_INFO(&hmp->rb_inos_root, &iinfo);
425 	if (ip) {
426 		if (ip->flags & HAMMER_INODE_DUMMY) {
427 			*errorp = ENOENT;
428 			return(NULL);
429 		}
430 		hammer_ref(&ip->lock);
431 		*errorp = 0;
432 		return(ip);
433 	}
434 
435 	/*
436 	 * Allocate a new inode structure and deal with races later.
437 	 */
438 	ip = kmalloc(sizeof(*ip), hmp->m_inodes, M_WAITOK|M_ZERO);
439 	++hammer_count_inodes;
440 	++hmp->count_inodes;
441 	ip->obj_id = obj_id;
442 	ip->obj_asof = iinfo.obj_asof;
443 	ip->obj_localization = localization;
444 	ip->hmp = hmp;
445 	ip->flags = flags & HAMMER_INODE_RO;
446 	ip->cache[0].ip = ip;
447 	ip->cache[1].ip = ip;
448 	ip->cache[2].ip = ip;
449 	ip->cache[3].ip = ip;
450 	if (hmp->ronly)
451 		ip->flags |= HAMMER_INODE_RO;
452 	ip->sync_trunc_off = ip->trunc_off = ip->save_trunc_off =
453 		0x7FFFFFFFFFFFFFFFLL;
454 	RB_INIT(&ip->rec_tree);
455 	TAILQ_INIT(&ip->target_list);
456 	hammer_ref(&ip->lock);
457 
458 	/*
459 	 * Locate the on-disk inode.  If this is a PFS root we always
460 	 * access the current version of the root inode and (if it is not
461 	 * a master) always access information under it with a snapshot
462 	 * TID.
463 	 *
464 	 * We cache recent inode lookups in this directory in dip->cache[2].
465 	 * If we can't find it we assume the inode we are looking for is
466 	 * close to the directory inode.
467 	 */
468 retry:
469 	cachep = NULL;
470 	if (dip) {
471 		if (dip->cache[2].node)
472 			cachep = &dip->cache[2];
473 		else
474 			cachep = &dip->cache[0];
475 	}
476 	hammer_init_cursor(trans, &cursor, cachep, NULL);
477 	cursor.key_beg.localization = localization + HAMMER_LOCALIZE_INODE;
478 	cursor.key_beg.obj_id = ip->obj_id;
479 	cursor.key_beg.key = 0;
480 	cursor.key_beg.create_tid = 0;
481 	cursor.key_beg.delete_tid = 0;
482 	cursor.key_beg.rec_type = HAMMER_RECTYPE_INODE;
483 	cursor.key_beg.obj_type = 0;
484 
485 	cursor.asof = iinfo.obj_asof;
486 	cursor.flags = HAMMER_CURSOR_GET_LEAF | HAMMER_CURSOR_GET_DATA |
487 		       HAMMER_CURSOR_ASOF;
488 
489 	*errorp = hammer_btree_lookup(&cursor);
490 	if (*errorp == EDEADLK) {
491 		hammer_done_cursor(&cursor);
492 		goto retry;
493 	}
494 
495 	/*
496 	 * On success the B-Tree lookup will hold the appropriate
497 	 * buffer cache buffers and provide a pointer to the requested
498 	 * information.  Copy the information to the in-memory inode
499 	 * and cache the B-Tree node to improve future operations.
500 	 */
501 	if (*errorp == 0) {
502 		ip->ino_leaf = cursor.node->ondisk->elms[cursor.index].leaf;
503 		ip->ino_data = cursor.data->inode;
504 
505 		/*
506 		 * cache[0] tries to cache the location of the object inode.
507 		 * The assumption is that it is near the directory inode.
508 		 *
509 		 * cache[1] tries to cache the location of the object data.
510 		 * We might have something in the governing directory from
511 		 * scan optimizations (see the strategy code in
512 		 * hammer_vnops.c).
513 		 *
514 		 * We update dip->cache[2], if possible, with the location
515 		 * of the object inode for future directory shortcuts.
516 		 */
517 		hammer_cache_node(&ip->cache[0], cursor.node);
518 		if (dip) {
519 			if (dip->cache[3].node) {
520 				hammer_cache_node(&ip->cache[1],
521 						  dip->cache[3].node);
522 			}
523 			hammer_cache_node(&dip->cache[2], cursor.node);
524 		}
525 
526 		/*
527 		 * The file should not contain any data past the file size
528 		 * stored in the inode.  Setting save_trunc_off to the
529 		 * file size instead of max reduces B-Tree lookup overheads
530 		 * on append by allowing the flusher to avoid checking for
531 		 * record overwrites.
532 		 */
533 		ip->save_trunc_off = ip->ino_data.size;
534 
535 		/*
536 		 * Locate and assign the pseudofs management structure to
537 		 * the inode.
538 		 */
539 		if (dip && dip->obj_localization == ip->obj_localization) {
540 			ip->pfsm = dip->pfsm;
541 			hammer_ref(&ip->pfsm->lock);
542 		} else {
543 			ip->pfsm = hammer_load_pseudofs(trans,
544 							ip->obj_localization,
545 							errorp);
546 			*errorp = 0;	/* ignore ENOENT */
547 		}
548 	}
549 
550 	/*
551 	 * The inode is placed on the red-black tree and will be synced to
552 	 * the media when flushed or by the filesystem sync.  If this races
553 	 * another instantiation/lookup the insertion will fail.
554 	 */
555 	if (*errorp == 0) {
556 		if (RB_INSERT(hammer_ino_rb_tree, &hmp->rb_inos_root, ip)) {
557 			hammer_free_inode(ip);
558 			hammer_done_cursor(&cursor);
559 			goto loop;
560 		}
561 		ip->flags |= HAMMER_INODE_ONDISK;
562 	} else {
563 		if (ip->flags & HAMMER_INODE_RSV_INODES) {
564 			ip->flags &= ~HAMMER_INODE_RSV_INODES; /* sanity */
565 			--hmp->rsv_inodes;
566 		}
567 
568 		hammer_free_inode(ip);
569 		ip = NULL;
570 	}
571 	hammer_done_cursor(&cursor);
572 
573 	/*
574 	 * NEWINODE is only set if the inode becomes dirty later,
575 	 * setting it here just leads to unnecessary stalls.
576 	 *
577 	 * trans->flags |= HAMMER_TRANSF_NEWINODE;
578 	 */
579 	return (ip);
580 }
581 
582 /*
583  * Get a dummy inode to placemark a broken directory entry.
584  */
585 struct hammer_inode *
586 hammer_get_dummy_inode(hammer_transaction_t trans, hammer_inode_t dip,
587 		 int64_t obj_id, hammer_tid_t asof, u_int32_t localization,
588 		 int flags, int *errorp)
589 {
590 	hammer_mount_t hmp = trans->hmp;
591 	struct hammer_inode_info iinfo;
592 	struct hammer_inode *ip;
593 
594 	/*
595 	 * Determine if we already have an inode cached.  If we do then
596 	 * we are golden.
597 	 *
598 	 * If we find an inode with no vnode we have to mark the
599 	 * transaction such that hammer_inode_waitreclaims() is
600 	 * called later on to avoid building up an infinite number
601 	 * of inodes.  Otherwise we can continue to * add new inodes
602 	 * faster then they can be disposed of, even with the tsleep
603 	 * delay.
604 	 *
605 	 * If we find a non-fake inode we return an error.  Only fake
606 	 * inodes can be returned by this routine.
607 	 */
608 	iinfo.obj_id = obj_id;
609 	iinfo.obj_asof = asof;
610 	iinfo.obj_localization = localization;
611 loop:
612 	*errorp = 0;
613 	ip = hammer_ino_rb_tree_RB_LOOKUP_INFO(&hmp->rb_inos_root, &iinfo);
614 	if (ip) {
615 		if ((ip->flags & HAMMER_INODE_DUMMY) == 0) {
616 			*errorp = ENOENT;
617 			return(NULL);
618 		}
619 		hammer_ref(&ip->lock);
620 		return(ip);
621 	}
622 
623 	/*
624 	 * Allocate a new inode structure and deal with races later.
625 	 */
626 	ip = kmalloc(sizeof(*ip), hmp->m_inodes, M_WAITOK|M_ZERO);
627 	++hammer_count_inodes;
628 	++hmp->count_inodes;
629 	ip->obj_id = obj_id;
630 	ip->obj_asof = iinfo.obj_asof;
631 	ip->obj_localization = localization;
632 	ip->hmp = hmp;
633 	ip->flags = flags | HAMMER_INODE_RO | HAMMER_INODE_DUMMY;
634 	ip->cache[0].ip = ip;
635 	ip->cache[1].ip = ip;
636 	ip->cache[2].ip = ip;
637 	ip->cache[3].ip = ip;
638 	ip->sync_trunc_off = ip->trunc_off = ip->save_trunc_off =
639 		0x7FFFFFFFFFFFFFFFLL;
640 	RB_INIT(&ip->rec_tree);
641 	TAILQ_INIT(&ip->target_list);
642 	hammer_ref(&ip->lock);
643 
644 	/*
645 	 * Populate the dummy inode.  Leave everything zero'd out.
646 	 *
647 	 * (ip->ino_leaf and ip->ino_data)
648 	 *
649 	 * Make the dummy inode a FIFO object which most copy programs
650 	 * will properly ignore.
651 	 */
652 	ip->save_trunc_off = ip->ino_data.size;
653 	ip->ino_data.obj_type = HAMMER_OBJTYPE_FIFO;
654 
655 	/*
656 	 * Locate and assign the pseudofs management structure to
657 	 * the inode.
658 	 */
659 	if (dip && dip->obj_localization == ip->obj_localization) {
660 		ip->pfsm = dip->pfsm;
661 		hammer_ref(&ip->pfsm->lock);
662 	} else {
663 		ip->pfsm = hammer_load_pseudofs(trans, ip->obj_localization,
664 						errorp);
665 		*errorp = 0;	/* ignore ENOENT */
666 	}
667 
668 	/*
669 	 * The inode is placed on the red-black tree and will be synced to
670 	 * the media when flushed or by the filesystem sync.  If this races
671 	 * another instantiation/lookup the insertion will fail.
672 	 *
673 	 * NOTE: Do not set HAMMER_INODE_ONDISK.  The inode is a fake.
674 	 */
675 	if (*errorp == 0) {
676 		if (RB_INSERT(hammer_ino_rb_tree, &hmp->rb_inos_root, ip)) {
677 			hammer_free_inode(ip);
678 			goto loop;
679 		}
680 	} else {
681 		if (ip->flags & HAMMER_INODE_RSV_INODES) {
682 			ip->flags &= ~HAMMER_INODE_RSV_INODES; /* sanity */
683 			--hmp->rsv_inodes;
684 		}
685 		hammer_free_inode(ip);
686 		ip = NULL;
687 	}
688 	trans->flags |= HAMMER_TRANSF_NEWINODE;
689 	return (ip);
690 }
691 
692 /*
693  * Return a referenced inode only if it is in our inode cache.
694  *
695  * Dummy inodes do not count.
696  */
697 struct hammer_inode *
698 hammer_find_inode(hammer_transaction_t trans, int64_t obj_id,
699 		  hammer_tid_t asof, u_int32_t localization)
700 {
701 	hammer_mount_t hmp = trans->hmp;
702 	struct hammer_inode_info iinfo;
703 	struct hammer_inode *ip;
704 
705 	iinfo.obj_id = obj_id;
706 	iinfo.obj_asof = asof;
707 	iinfo.obj_localization = localization;
708 
709 	ip = hammer_ino_rb_tree_RB_LOOKUP_INFO(&hmp->rb_inos_root, &iinfo);
710 	if (ip) {
711 		if (ip->flags & HAMMER_INODE_DUMMY)
712 			ip = NULL;
713 		else
714 			hammer_ref(&ip->lock);
715 	}
716 	return(ip);
717 }
718 
719 /*
720  * Create a new filesystem object, returning the inode in *ipp.  The
721  * returned inode will be referenced.  The inode is created in-memory.
722  *
723  * If pfsm is non-NULL the caller wishes to create the root inode for
724  * a master PFS.
725  */
726 int
727 hammer_create_inode(hammer_transaction_t trans, struct vattr *vap,
728 		    struct ucred *cred,
729 		    hammer_inode_t dip, const char *name, int namelen,
730 		    hammer_pseudofs_inmem_t pfsm, struct hammer_inode **ipp)
731 {
732 	hammer_mount_t hmp;
733 	hammer_inode_t ip;
734 	uid_t xuid;
735 	int error;
736 	int64_t namekey;
737 	u_int32_t dummy;
738 
739 	hmp = trans->hmp;
740 
741 	ip = kmalloc(sizeof(*ip), hmp->m_inodes, M_WAITOK|M_ZERO);
742 	++hammer_count_inodes;
743 	++hmp->count_inodes;
744 	trans->flags |= HAMMER_TRANSF_NEWINODE;
745 
746 	if (pfsm) {
747 		KKASSERT(pfsm->localization != 0);
748 		ip->obj_id = HAMMER_OBJID_ROOT;
749 		ip->obj_localization = pfsm->localization;
750 	} else {
751 		KKASSERT(dip != NULL);
752 		namekey = hammer_directory_namekey(dip, name, namelen, &dummy);
753 		ip->obj_id = hammer_alloc_objid(hmp, dip, namekey);
754 		ip->obj_localization = dip->obj_localization;
755 	}
756 
757 	KKASSERT(ip->obj_id != 0);
758 	ip->obj_asof = hmp->asof;
759 	ip->hmp = hmp;
760 	ip->flush_state = HAMMER_FST_IDLE;
761 	ip->flags = HAMMER_INODE_DDIRTY |
762 		    HAMMER_INODE_ATIME | HAMMER_INODE_MTIME;
763 	ip->cache[0].ip = ip;
764 	ip->cache[1].ip = ip;
765 	ip->cache[2].ip = ip;
766 	ip->cache[3].ip = ip;
767 
768 	ip->trunc_off = 0x7FFFFFFFFFFFFFFFLL;
769 	/* ip->save_trunc_off = 0; (already zero) */
770 	RB_INIT(&ip->rec_tree);
771 	TAILQ_INIT(&ip->target_list);
772 
773 	ip->ino_data.atime = trans->time;
774 	ip->ino_data.mtime = trans->time;
775 	ip->ino_data.size = 0;
776 	ip->ino_data.nlinks = 0;
777 
778 	/*
779 	 * A nohistory designator on the parent directory is inherited by
780 	 * the child.  We will do this even for pseudo-fs creation... the
781 	 * sysad can turn it off.
782 	 */
783 	if (dip) {
784 		ip->ino_data.uflags = dip->ino_data.uflags &
785 				      (SF_NOHISTORY|UF_NOHISTORY|UF_NODUMP);
786 	}
787 
788 	ip->ino_leaf.base.btype = HAMMER_BTREE_TYPE_RECORD;
789 	ip->ino_leaf.base.localization = ip->obj_localization +
790 					 HAMMER_LOCALIZE_INODE;
791 	ip->ino_leaf.base.obj_id = ip->obj_id;
792 	ip->ino_leaf.base.key = 0;
793 	ip->ino_leaf.base.create_tid = 0;
794 	ip->ino_leaf.base.delete_tid = 0;
795 	ip->ino_leaf.base.rec_type = HAMMER_RECTYPE_INODE;
796 	ip->ino_leaf.base.obj_type = hammer_get_obj_type(vap->va_type);
797 
798 	ip->ino_data.obj_type = ip->ino_leaf.base.obj_type;
799 	ip->ino_data.version = HAMMER_INODE_DATA_VERSION;
800 	ip->ino_data.mode = vap->va_mode;
801 	ip->ino_data.ctime = trans->time;
802 
803 	/*
804 	 * If we are running version 2 or greater directory entries are
805 	 * inode-localized instead of data-localized.
806 	 */
807 	if (trans->hmp->version >= HAMMER_VOL_VERSION_TWO) {
808 		if (ip->ino_leaf.base.obj_type == HAMMER_OBJTYPE_DIRECTORY) {
809 			ip->ino_data.cap_flags |=
810 				HAMMER_INODE_CAP_DIR_LOCAL_INO;
811 		}
812 	}
813 	if (trans->hmp->version >= HAMMER_VOL_VERSION_SIX) {
814 		if (ip->ino_leaf.base.obj_type == HAMMER_OBJTYPE_DIRECTORY) {
815 			ip->ino_data.cap_flags |=
816 				HAMMER_INODE_CAP_DIRHASH_ALG1;
817 		}
818 	}
819 
820 	/*
821 	 * Setup the ".." pointer.  This only needs to be done for directories
822 	 * but we do it for all objects as a recovery aid.
823 	 */
824 	if (dip)
825 		ip->ino_data.parent_obj_id = dip->ino_leaf.base.obj_id;
826 #if 0
827 	/*
828 	 * The parent_obj_localization field only applies to pseudo-fs roots.
829 	 * XXX this is no longer applicable, PFSs are no longer directly
830 	 * tied into the parent's directory structure.
831 	 */
832 	if (ip->ino_data.obj_type == HAMMER_OBJTYPE_DIRECTORY &&
833 	    ip->obj_id == HAMMER_OBJID_ROOT) {
834 		ip->ino_data.ext.obj.parent_obj_localization =
835 						dip->obj_localization;
836 	}
837 #endif
838 
839 	switch(ip->ino_leaf.base.obj_type) {
840 	case HAMMER_OBJTYPE_CDEV:
841 	case HAMMER_OBJTYPE_BDEV:
842 		ip->ino_data.rmajor = vap->va_rmajor;
843 		ip->ino_data.rminor = vap->va_rminor;
844 		break;
845 	default:
846 		break;
847 	}
848 
849 	/*
850 	 * Calculate default uid/gid and overwrite with information from
851 	 * the vap.
852 	 */
853 	if (dip) {
854 		xuid = hammer_to_unix_xid(&dip->ino_data.uid);
855 		xuid = vop_helper_create_uid(hmp->mp, dip->ino_data.mode,
856 					     xuid, cred, &vap->va_mode);
857 	} else {
858 		xuid = 0;
859 	}
860 	ip->ino_data.mode = vap->va_mode;
861 
862 	if (vap->va_vaflags & VA_UID_UUID_VALID)
863 		ip->ino_data.uid = vap->va_uid_uuid;
864 	else if (vap->va_uid != (uid_t)VNOVAL)
865 		hammer_guid_to_uuid(&ip->ino_data.uid, vap->va_uid);
866 	else
867 		hammer_guid_to_uuid(&ip->ino_data.uid, xuid);
868 
869 	if (vap->va_vaflags & VA_GID_UUID_VALID)
870 		ip->ino_data.gid = vap->va_gid_uuid;
871 	else if (vap->va_gid != (gid_t)VNOVAL)
872 		hammer_guid_to_uuid(&ip->ino_data.gid, vap->va_gid);
873 	else if (dip)
874 		ip->ino_data.gid = dip->ino_data.gid;
875 
876 	hammer_ref(&ip->lock);
877 
878 	if (pfsm) {
879 		ip->pfsm = pfsm;
880 		hammer_ref(&pfsm->lock);
881 		error = 0;
882 	} else if (dip->obj_localization == ip->obj_localization) {
883 		ip->pfsm = dip->pfsm;
884 		hammer_ref(&ip->pfsm->lock);
885 		error = 0;
886 	} else {
887 		ip->pfsm = hammer_load_pseudofs(trans,
888 						ip->obj_localization,
889 						&error);
890 		error = 0;	/* ignore ENOENT */
891 	}
892 
893 	if (error) {
894 		hammer_free_inode(ip);
895 		ip = NULL;
896 	} else if (RB_INSERT(hammer_ino_rb_tree, &hmp->rb_inos_root, ip)) {
897 		panic("hammer_create_inode: duplicate obj_id %llx",
898 		      (long long)ip->obj_id);
899 		/* not reached */
900 		hammer_free_inode(ip);
901 	}
902 	*ipp = ip;
903 	return(error);
904 }
905 
906 /*
907  * Final cleanup / freeing of an inode structure
908  */
909 static void
910 hammer_free_inode(hammer_inode_t ip)
911 {
912 	struct hammer_mount *hmp;
913 
914 	hmp = ip->hmp;
915 	KKASSERT(hammer_oneref(&ip->lock));
916 	hammer_uncache_node(&ip->cache[0]);
917 	hammer_uncache_node(&ip->cache[1]);
918 	hammer_uncache_node(&ip->cache[2]);
919 	hammer_uncache_node(&ip->cache[3]);
920 	hammer_inode_wakereclaims(ip);
921 	if (ip->objid_cache)
922 		hammer_clear_objid(ip);
923 	--hammer_count_inodes;
924 	--hmp->count_inodes;
925 	if (ip->pfsm) {
926 		hammer_rel_pseudofs(hmp, ip->pfsm);
927 		ip->pfsm = NULL;
928 	}
929 	kfree(ip, hmp->m_inodes);
930 	ip = NULL;
931 }
932 
933 /*
934  * Retrieve pseudo-fs data.  NULL will never be returned.
935  *
936  * If an error occurs *errorp will be set and a default template is returned,
937  * otherwise *errorp is set to 0.  Typically when an error occurs it will
938  * be ENOENT.
939  */
940 hammer_pseudofs_inmem_t
941 hammer_load_pseudofs(hammer_transaction_t trans,
942 		     u_int32_t localization, int *errorp)
943 {
944 	hammer_mount_t hmp = trans->hmp;
945 	hammer_inode_t ip;
946 	hammer_pseudofs_inmem_t pfsm;
947 	struct hammer_cursor cursor;
948 	int bytes;
949 
950 retry:
951 	pfsm = RB_LOOKUP(hammer_pfs_rb_tree, &hmp->rb_pfsm_root, localization);
952 	if (pfsm) {
953 		hammer_ref(&pfsm->lock);
954 		*errorp = 0;
955 		return(pfsm);
956 	}
957 
958 	/*
959 	 * PFS records are stored in the root inode (not the PFS root inode,
960 	 * but the real root).  Avoid an infinite recursion if loading
961 	 * the PFS for the real root.
962 	 */
963 	if (localization) {
964 		ip = hammer_get_inode(trans, NULL, HAMMER_OBJID_ROOT,
965 				      HAMMER_MAX_TID,
966 				      HAMMER_DEF_LOCALIZATION, 0, errorp);
967 	} else {
968 		ip = NULL;
969 	}
970 
971 	pfsm = kmalloc(sizeof(*pfsm), hmp->m_misc, M_WAITOK | M_ZERO);
972 	pfsm->localization = localization;
973 	pfsm->pfsd.unique_uuid = trans->rootvol->ondisk->vol_fsid;
974 	pfsm->pfsd.shared_uuid = pfsm->pfsd.unique_uuid;
975 
976 	hammer_init_cursor(trans, &cursor, (ip ? &ip->cache[1] : NULL), ip);
977 	cursor.key_beg.localization = HAMMER_DEF_LOCALIZATION +
978 				      HAMMER_LOCALIZE_MISC;
979 	cursor.key_beg.obj_id = HAMMER_OBJID_ROOT;
980 	cursor.key_beg.create_tid = 0;
981 	cursor.key_beg.delete_tid = 0;
982 	cursor.key_beg.rec_type = HAMMER_RECTYPE_PFS;
983 	cursor.key_beg.obj_type = 0;
984 	cursor.key_beg.key = localization;
985 	cursor.asof = HAMMER_MAX_TID;
986 	cursor.flags |= HAMMER_CURSOR_ASOF;
987 
988 	if (ip)
989 		*errorp = hammer_ip_lookup(&cursor);
990 	else
991 		*errorp = hammer_btree_lookup(&cursor);
992 	if (*errorp == 0) {
993 		*errorp = hammer_ip_resolve_data(&cursor);
994 		if (*errorp == 0) {
995 			if (cursor.data->pfsd.mirror_flags &
996 			    HAMMER_PFSD_DELETED) {
997 				*errorp = ENOENT;
998 			} else {
999 				bytes = cursor.leaf->data_len;
1000 				if (bytes > sizeof(pfsm->pfsd))
1001 					bytes = sizeof(pfsm->pfsd);
1002 				bcopy(cursor.data, &pfsm->pfsd, bytes);
1003 			}
1004 		}
1005 	}
1006 	hammer_done_cursor(&cursor);
1007 
1008 	pfsm->fsid_udev = hammer_fsid_to_udev(&pfsm->pfsd.shared_uuid);
1009 	hammer_ref(&pfsm->lock);
1010 	if (ip)
1011 		hammer_rel_inode(ip, 0);
1012 	if (RB_INSERT(hammer_pfs_rb_tree, &hmp->rb_pfsm_root, pfsm)) {
1013 		kfree(pfsm, hmp->m_misc);
1014 		goto retry;
1015 	}
1016 	return(pfsm);
1017 }
1018 
1019 /*
1020  * Store pseudo-fs data.  The backend will automatically delete any prior
1021  * on-disk pseudo-fs data but we have to delete in-memory versions.
1022  */
1023 int
1024 hammer_save_pseudofs(hammer_transaction_t trans, hammer_pseudofs_inmem_t pfsm)
1025 {
1026 	struct hammer_cursor cursor;
1027 	hammer_record_t record;
1028 	hammer_inode_t ip;
1029 	int error;
1030 
1031 	ip = hammer_get_inode(trans, NULL, HAMMER_OBJID_ROOT, HAMMER_MAX_TID,
1032 			      HAMMER_DEF_LOCALIZATION, 0, &error);
1033 retry:
1034 	pfsm->fsid_udev = hammer_fsid_to_udev(&pfsm->pfsd.shared_uuid);
1035 	hammer_init_cursor(trans, &cursor, &ip->cache[1], ip);
1036 	cursor.key_beg.localization = ip->obj_localization +
1037 				      HAMMER_LOCALIZE_MISC;
1038 	cursor.key_beg.obj_id = HAMMER_OBJID_ROOT;
1039 	cursor.key_beg.create_tid = 0;
1040 	cursor.key_beg.delete_tid = 0;
1041 	cursor.key_beg.rec_type = HAMMER_RECTYPE_PFS;
1042 	cursor.key_beg.obj_type = 0;
1043 	cursor.key_beg.key = pfsm->localization;
1044 	cursor.asof = HAMMER_MAX_TID;
1045 	cursor.flags |= HAMMER_CURSOR_ASOF;
1046 
1047 	/*
1048 	 * Replace any in-memory version of the record.
1049 	 */
1050 	error = hammer_ip_lookup(&cursor);
1051 	if (error == 0 && hammer_cursor_inmem(&cursor)) {
1052 		record = cursor.iprec;
1053 		if (record->flags & HAMMER_RECF_INTERLOCK_BE) {
1054 			KKASSERT(cursor.deadlk_rec == NULL);
1055 			hammer_ref(&record->lock);
1056 			cursor.deadlk_rec = record;
1057 			error = EDEADLK;
1058 		} else {
1059 			record->flags |= HAMMER_RECF_DELETED_FE;
1060 			error = 0;
1061 		}
1062 	}
1063 
1064 	/*
1065 	 * Allocate replacement general record.  The backend flush will
1066 	 * delete any on-disk version of the record.
1067 	 */
1068 	if (error == 0 || error == ENOENT) {
1069 		record = hammer_alloc_mem_record(ip, sizeof(pfsm->pfsd));
1070 		record->type = HAMMER_MEM_RECORD_GENERAL;
1071 
1072 		record->leaf.base.localization = ip->obj_localization +
1073 						 HAMMER_LOCALIZE_MISC;
1074 		record->leaf.base.rec_type = HAMMER_RECTYPE_PFS;
1075 		record->leaf.base.key = pfsm->localization;
1076 		record->leaf.data_len = sizeof(pfsm->pfsd);
1077 		bcopy(&pfsm->pfsd, record->data, sizeof(pfsm->pfsd));
1078 		error = hammer_ip_add_record(trans, record);
1079 	}
1080 	hammer_done_cursor(&cursor);
1081 	if (error == EDEADLK)
1082 		goto retry;
1083 	hammer_rel_inode(ip, 0);
1084 	return(error);
1085 }
1086 
1087 /*
1088  * Create a root directory for a PFS if one does not alredy exist.
1089  *
1090  * The PFS root stands alone so we must also bump the nlinks count
1091  * to prevent it from being destroyed on release.
1092  */
1093 int
1094 hammer_mkroot_pseudofs(hammer_transaction_t trans, struct ucred *cred,
1095 		       hammer_pseudofs_inmem_t pfsm)
1096 {
1097 	hammer_inode_t ip;
1098 	struct vattr vap;
1099 	int error;
1100 
1101 	ip = hammer_get_inode(trans, NULL, HAMMER_OBJID_ROOT, HAMMER_MAX_TID,
1102 			      pfsm->localization, 0, &error);
1103 	if (ip == NULL) {
1104 		vattr_null(&vap);
1105 		vap.va_mode = 0755;
1106 		vap.va_type = VDIR;
1107 		error = hammer_create_inode(trans, &vap, cred,
1108 					    NULL, NULL, 0,
1109 					    pfsm, &ip);
1110 		if (error == 0) {
1111 			++ip->ino_data.nlinks;
1112 			hammer_modify_inode(trans, ip, HAMMER_INODE_DDIRTY);
1113 		}
1114 	}
1115 	if (ip)
1116 		hammer_rel_inode(ip, 0);
1117 	return(error);
1118 }
1119 
1120 /*
1121  * Unload any vnodes & inodes associated with a PFS, return ENOTEMPTY
1122  * if we are unable to disassociate all the inodes.
1123  */
1124 static
1125 int
1126 hammer_unload_pseudofs_callback(hammer_inode_t ip, void *data)
1127 {
1128 	int res;
1129 
1130 	hammer_ref(&ip->lock);
1131 	if (hammer_isactive(&ip->lock) == 2 && ip->vp)
1132 		vclean_unlocked(ip->vp);
1133 	if (hammer_isactive(&ip->lock) == 1 && ip->vp == NULL)
1134 		res = 0;
1135 	else
1136 		res = -1;	/* stop, someone is using the inode */
1137 	hammer_rel_inode(ip, 0);
1138 	return(res);
1139 }
1140 
1141 int
1142 hammer_unload_pseudofs(hammer_transaction_t trans, u_int32_t localization)
1143 {
1144 	int res;
1145 	int try;
1146 
1147 	for (try = res = 0; try < 4; ++try) {
1148 		res = hammer_ino_rb_tree_RB_SCAN(&trans->hmp->rb_inos_root,
1149 					   hammer_inode_pfs_cmp,
1150 					   hammer_unload_pseudofs_callback,
1151 					   &localization);
1152 		if (res == 0 && try > 1)
1153 			break;
1154 		hammer_flusher_sync(trans->hmp);
1155 	}
1156 	if (res != 0)
1157 		res = ENOTEMPTY;
1158 	return(res);
1159 }
1160 
1161 
1162 /*
1163  * Release a reference on a PFS
1164  */
1165 void
1166 hammer_rel_pseudofs(hammer_mount_t hmp, hammer_pseudofs_inmem_t pfsm)
1167 {
1168 	hammer_rel(&pfsm->lock);
1169 	if (hammer_norefs(&pfsm->lock)) {
1170 		RB_REMOVE(hammer_pfs_rb_tree, &hmp->rb_pfsm_root, pfsm);
1171 		kfree(pfsm, hmp->m_misc);
1172 	}
1173 }
1174 
1175 /*
1176  * Called by hammer_sync_inode().
1177  */
1178 static int
1179 hammer_update_inode(hammer_cursor_t cursor, hammer_inode_t ip)
1180 {
1181 	hammer_transaction_t trans = cursor->trans;
1182 	hammer_record_t record;
1183 	int error;
1184 	int redirty;
1185 
1186 retry:
1187 	error = 0;
1188 
1189 	/*
1190 	 * If the inode has a presence on-disk then locate it and mark
1191 	 * it deleted, setting DELONDISK.
1192 	 *
1193 	 * The record may or may not be physically deleted, depending on
1194 	 * the retention policy.
1195 	 */
1196 	if ((ip->flags & (HAMMER_INODE_ONDISK|HAMMER_INODE_DELONDISK)) ==
1197 	    HAMMER_INODE_ONDISK) {
1198 		hammer_normalize_cursor(cursor);
1199 		cursor->key_beg.localization = ip->obj_localization +
1200 					       HAMMER_LOCALIZE_INODE;
1201 		cursor->key_beg.obj_id = ip->obj_id;
1202 		cursor->key_beg.key = 0;
1203 		cursor->key_beg.create_tid = 0;
1204 		cursor->key_beg.delete_tid = 0;
1205 		cursor->key_beg.rec_type = HAMMER_RECTYPE_INODE;
1206 		cursor->key_beg.obj_type = 0;
1207 		cursor->asof = ip->obj_asof;
1208 		cursor->flags &= ~HAMMER_CURSOR_INITMASK;
1209 		cursor->flags |= HAMMER_CURSOR_GET_LEAF | HAMMER_CURSOR_ASOF;
1210 		cursor->flags |= HAMMER_CURSOR_BACKEND;
1211 
1212 		error = hammer_btree_lookup(cursor);
1213 		if (hammer_debug_inode)
1214 			kprintf("IPDEL %p %08x %d", ip, ip->flags, error);
1215 
1216 		if (error == 0) {
1217 			error = hammer_ip_delete_record(cursor, ip, trans->tid);
1218 			if (hammer_debug_inode)
1219 				kprintf(" error %d\n", error);
1220 			if (error == 0) {
1221 				ip->flags |= HAMMER_INODE_DELONDISK;
1222 			}
1223 			if (cursor->node)
1224 				hammer_cache_node(&ip->cache[0], cursor->node);
1225 		}
1226 		if (error == EDEADLK) {
1227 			hammer_done_cursor(cursor);
1228 			error = hammer_init_cursor(trans, cursor,
1229 						   &ip->cache[0], ip);
1230 			if (hammer_debug_inode)
1231 				kprintf("IPDED %p %d\n", ip, error);
1232 			if (error == 0)
1233 				goto retry;
1234 		}
1235 	}
1236 
1237 	/*
1238 	 * Ok, write out the initial record or a new record (after deleting
1239 	 * the old one), unless the DELETED flag is set.  This routine will
1240 	 * clear DELONDISK if it writes out a record.
1241 	 *
1242 	 * Update our inode statistics if this is the first application of
1243 	 * the inode on-disk.
1244 	 */
1245 	if (error == 0 && (ip->flags & HAMMER_INODE_DELETED) == 0) {
1246 		/*
1247 		 * Generate a record and write it to the media.  We clean-up
1248 		 * the state before releasing so we do not have to set-up
1249 		 * a flush_group.
1250 		 */
1251 		record = hammer_alloc_mem_record(ip, 0);
1252 		record->type = HAMMER_MEM_RECORD_INODE;
1253 		record->flush_state = HAMMER_FST_FLUSH;
1254 		record->leaf = ip->sync_ino_leaf;
1255 		record->leaf.base.create_tid = trans->tid;
1256 		record->leaf.data_len = sizeof(ip->sync_ino_data);
1257 		record->leaf.create_ts = trans->time32;
1258 		record->data = (void *)&ip->sync_ino_data;
1259 		record->flags |= HAMMER_RECF_INTERLOCK_BE;
1260 
1261 		/*
1262 		 * If this flag is set we cannot sync the new file size
1263 		 * because we haven't finished related truncations.  The
1264 		 * inode will be flushed in another flush group to finish
1265 		 * the job.
1266 		 */
1267 		if ((ip->flags & HAMMER_INODE_WOULDBLOCK) &&
1268 		    ip->sync_ino_data.size != ip->ino_data.size) {
1269 			redirty = 1;
1270 			ip->sync_ino_data.size = ip->ino_data.size;
1271 		} else {
1272 			redirty = 0;
1273 		}
1274 
1275 		for (;;) {
1276 			error = hammer_ip_sync_record_cursor(cursor, record);
1277 			if (hammer_debug_inode)
1278 				kprintf("GENREC %p rec %08x %d\n",
1279 					ip, record->flags, error);
1280 			if (error != EDEADLK)
1281 				break;
1282 			hammer_done_cursor(cursor);
1283 			error = hammer_init_cursor(trans, cursor,
1284 						   &ip->cache[0], ip);
1285 			if (hammer_debug_inode)
1286 				kprintf("GENREC reinit %d\n", error);
1287 			if (error)
1288 				break;
1289 		}
1290 
1291 		/*
1292 		 * Note:  The record was never on the inode's record tree
1293 		 * so just wave our hands importantly and destroy it.
1294 		 */
1295 		record->flags |= HAMMER_RECF_COMMITTED;
1296 		record->flags &= ~HAMMER_RECF_INTERLOCK_BE;
1297 		record->flush_state = HAMMER_FST_IDLE;
1298 		++ip->rec_generation;
1299 		hammer_rel_mem_record(record);
1300 
1301 		/*
1302 		 * Finish up.
1303 		 */
1304 		if (error == 0) {
1305 			if (hammer_debug_inode)
1306 				kprintf("CLEANDELOND %p %08x\n", ip, ip->flags);
1307 			ip->sync_flags &= ~(HAMMER_INODE_DDIRTY |
1308 					    HAMMER_INODE_SDIRTY |
1309 					    HAMMER_INODE_ATIME |
1310 					    HAMMER_INODE_MTIME);
1311 			ip->flags &= ~HAMMER_INODE_DELONDISK;
1312 			if (redirty)
1313 				ip->sync_flags |= HAMMER_INODE_DDIRTY;
1314 
1315 			/*
1316 			 * Root volume count of inodes
1317 			 */
1318 			hammer_sync_lock_sh(trans);
1319 			if ((ip->flags & HAMMER_INODE_ONDISK) == 0) {
1320 				hammer_modify_volume_field(trans,
1321 							   trans->rootvol,
1322 							   vol0_stat_inodes);
1323 				++ip->hmp->rootvol->ondisk->vol0_stat_inodes;
1324 				hammer_modify_volume_done(trans->rootvol);
1325 				ip->flags |= HAMMER_INODE_ONDISK;
1326 				if (hammer_debug_inode)
1327 					kprintf("NOWONDISK %p\n", ip);
1328 			}
1329 			hammer_sync_unlock(trans);
1330 		}
1331 	}
1332 
1333 	/*
1334 	 * If the inode has been destroyed, clean out any left-over flags
1335 	 * that may have been set by the frontend.
1336 	 */
1337 	if (error == 0 && (ip->flags & HAMMER_INODE_DELETED)) {
1338 		ip->sync_flags &= ~(HAMMER_INODE_DDIRTY |
1339 				    HAMMER_INODE_SDIRTY |
1340 				    HAMMER_INODE_ATIME |
1341 				    HAMMER_INODE_MTIME);
1342 	}
1343 	return(error);
1344 }
1345 
1346 /*
1347  * Update only the itimes fields.
1348  *
1349  * ATIME can be updated without generating any UNDO.  MTIME is updated
1350  * with UNDO so it is guaranteed to be synchronized properly in case of
1351  * a crash.
1352  *
1353  * Neither field is included in the B-Tree leaf element's CRC, which is how
1354  * we can get away with updating ATIME the way we do.
1355  */
1356 static int
1357 hammer_update_itimes(hammer_cursor_t cursor, hammer_inode_t ip)
1358 {
1359 	hammer_transaction_t trans = cursor->trans;
1360 	int error;
1361 
1362 retry:
1363 	if ((ip->flags & (HAMMER_INODE_ONDISK|HAMMER_INODE_DELONDISK)) !=
1364 	    HAMMER_INODE_ONDISK) {
1365 		return(0);
1366 	}
1367 
1368 	hammer_normalize_cursor(cursor);
1369 	cursor->key_beg.localization = ip->obj_localization +
1370 				       HAMMER_LOCALIZE_INODE;
1371 	cursor->key_beg.obj_id = ip->obj_id;
1372 	cursor->key_beg.key = 0;
1373 	cursor->key_beg.create_tid = 0;
1374 	cursor->key_beg.delete_tid = 0;
1375 	cursor->key_beg.rec_type = HAMMER_RECTYPE_INODE;
1376 	cursor->key_beg.obj_type = 0;
1377 	cursor->asof = ip->obj_asof;
1378 	cursor->flags &= ~HAMMER_CURSOR_INITMASK;
1379 	cursor->flags |= HAMMER_CURSOR_ASOF;
1380 	cursor->flags |= HAMMER_CURSOR_GET_LEAF;
1381 	cursor->flags |= HAMMER_CURSOR_GET_DATA;
1382 	cursor->flags |= HAMMER_CURSOR_BACKEND;
1383 
1384 	error = hammer_btree_lookup(cursor);
1385 	if (error == 0) {
1386 		hammer_cache_node(&ip->cache[0], cursor->node);
1387 		if (ip->sync_flags & HAMMER_INODE_MTIME) {
1388 			/*
1389 			 * Updating MTIME requires an UNDO.  Just cover
1390 			 * both atime and mtime.
1391 			 */
1392 			hammer_sync_lock_sh(trans);
1393 			hammer_modify_buffer(trans, cursor->data_buffer,
1394 				     HAMMER_ITIMES_BASE(&cursor->data->inode),
1395 				     HAMMER_ITIMES_BYTES);
1396 			cursor->data->inode.atime = ip->sync_ino_data.atime;
1397 			cursor->data->inode.mtime = ip->sync_ino_data.mtime;
1398 			hammer_modify_buffer_done(cursor->data_buffer);
1399 			hammer_sync_unlock(trans);
1400 		} else if (ip->sync_flags & HAMMER_INODE_ATIME) {
1401 			/*
1402 			 * Updating atime only can be done in-place with
1403 			 * no UNDO.
1404 			 */
1405 			hammer_sync_lock_sh(trans);
1406 			hammer_modify_buffer(trans, cursor->data_buffer,
1407 					     NULL, 0);
1408 			cursor->data->inode.atime = ip->sync_ino_data.atime;
1409 			hammer_modify_buffer_done(cursor->data_buffer);
1410 			hammer_sync_unlock(trans);
1411 		}
1412 		ip->sync_flags &= ~(HAMMER_INODE_ATIME | HAMMER_INODE_MTIME);
1413 	}
1414 	if (error == EDEADLK) {
1415 		hammer_done_cursor(cursor);
1416 		error = hammer_init_cursor(trans, cursor,
1417 					   &ip->cache[0], ip);
1418 		if (error == 0)
1419 			goto retry;
1420 	}
1421 	return(error);
1422 }
1423 
1424 /*
1425  * Release a reference on an inode, flush as requested.
1426  *
1427  * On the last reference we queue the inode to the flusher for its final
1428  * disposition.
1429  */
1430 void
1431 hammer_rel_inode(struct hammer_inode *ip, int flush)
1432 {
1433 	/*hammer_mount_t hmp = ip->hmp;*/
1434 
1435 	/*
1436 	 * Handle disposition when dropping the last ref.
1437 	 */
1438 	for (;;) {
1439 		if (hammer_oneref(&ip->lock)) {
1440 			/*
1441 			 * Determine whether on-disk action is needed for
1442 			 * the inode's final disposition.
1443 			 */
1444 			KKASSERT(ip->vp == NULL);
1445 			hammer_inode_unloadable_check(ip, 0);
1446 			if (ip->flags & HAMMER_INODE_MODMASK) {
1447 				hammer_flush_inode(ip, 0);
1448 			} else if (hammer_oneref(&ip->lock)) {
1449 				hammer_unload_inode(ip);
1450 				break;
1451 			}
1452 		} else {
1453 			if (flush)
1454 				hammer_flush_inode(ip, 0);
1455 
1456 			/*
1457 			 * The inode still has multiple refs, try to drop
1458 			 * one ref.
1459 			 */
1460 			KKASSERT(hammer_isactive(&ip->lock) >= 1);
1461 			if (hammer_isactive(&ip->lock) > 1) {
1462 				hammer_rel(&ip->lock);
1463 				break;
1464 			}
1465 		}
1466 	}
1467 }
1468 
1469 /*
1470  * Unload and destroy the specified inode.  Must be called with one remaining
1471  * reference.  The reference is disposed of.
1472  *
1473  * The inode must be completely clean.
1474  */
1475 static int
1476 hammer_unload_inode(struct hammer_inode *ip)
1477 {
1478 	hammer_mount_t hmp = ip->hmp;
1479 
1480 	KASSERT(hammer_oneref(&ip->lock),
1481 		("hammer_unload_inode: %d refs\n", hammer_isactive(&ip->lock)));
1482 	KKASSERT(ip->vp == NULL);
1483 	KKASSERT(ip->flush_state == HAMMER_FST_IDLE);
1484 	KKASSERT(ip->cursor_ip_refs == 0);
1485 	KKASSERT(hammer_notlocked(&ip->lock));
1486 	KKASSERT((ip->flags & HAMMER_INODE_MODMASK) == 0);
1487 
1488 	KKASSERT(RB_EMPTY(&ip->rec_tree));
1489 	KKASSERT(TAILQ_EMPTY(&ip->target_list));
1490 
1491 	if (ip->flags & HAMMER_INODE_RDIRTY) {
1492 		RB_REMOVE(hammer_redo_rb_tree, &hmp->rb_redo_root, ip);
1493 		ip->flags &= ~HAMMER_INODE_RDIRTY;
1494 	}
1495 	RB_REMOVE(hammer_ino_rb_tree, &hmp->rb_inos_root, ip);
1496 
1497 	hammer_free_inode(ip);
1498 	return(0);
1499 }
1500 
1501 /*
1502  * Called during unmounting if a critical error occured.  The in-memory
1503  * inode and all related structures are destroyed.
1504  *
1505  * If a critical error did not occur the unmount code calls the standard
1506  * release and asserts that the inode is gone.
1507  */
1508 int
1509 hammer_destroy_inode_callback(struct hammer_inode *ip, void *data __unused)
1510 {
1511 	hammer_record_t rec;
1512 
1513 	/*
1514 	 * Get rid of the inodes in-memory records, regardless of their
1515 	 * state, and clear the mod-mask.
1516 	 */
1517 	while ((rec = TAILQ_FIRST(&ip->target_list)) != NULL) {
1518 		TAILQ_REMOVE(&ip->target_list, rec, target_entry);
1519 		rec->target_ip = NULL;
1520 		if (rec->flush_state == HAMMER_FST_SETUP)
1521 			rec->flush_state = HAMMER_FST_IDLE;
1522 	}
1523 	while ((rec = RB_ROOT(&ip->rec_tree)) != NULL) {
1524 		if (rec->flush_state == HAMMER_FST_FLUSH)
1525 			--rec->flush_group->refs;
1526 		else
1527 			hammer_ref(&rec->lock);
1528 		KKASSERT(hammer_oneref(&rec->lock));
1529 		rec->flush_state = HAMMER_FST_IDLE;
1530 		rec->flush_group = NULL;
1531 		rec->flags |= HAMMER_RECF_DELETED_FE; /* wave hands */
1532 		rec->flags |= HAMMER_RECF_DELETED_BE; /* wave hands */
1533 		++ip->rec_generation;
1534 		hammer_rel_mem_record(rec);
1535 	}
1536 	ip->flags &= ~HAMMER_INODE_MODMASK;
1537 	ip->sync_flags &= ~HAMMER_INODE_MODMASK;
1538 	KKASSERT(ip->vp == NULL);
1539 
1540 	/*
1541 	 * Remove the inode from any flush group, force it idle.  FLUSH
1542 	 * and SETUP states have an inode ref.
1543 	 */
1544 	switch(ip->flush_state) {
1545 	case HAMMER_FST_FLUSH:
1546 		RB_REMOVE(hammer_fls_rb_tree, &ip->flush_group->flush_tree, ip);
1547 		--ip->flush_group->refs;
1548 		ip->flush_group = NULL;
1549 		/* fall through */
1550 	case HAMMER_FST_SETUP:
1551 		hammer_rel(&ip->lock);
1552 		ip->flush_state = HAMMER_FST_IDLE;
1553 		/* fall through */
1554 	case HAMMER_FST_IDLE:
1555 		break;
1556 	}
1557 
1558 	/*
1559 	 * There shouldn't be any associated vnode.  The unload needs at
1560 	 * least one ref, if we do have a vp steal its ip ref.
1561 	 */
1562 	if (ip->vp) {
1563 		kprintf("hammer_destroy_inode_callback: Unexpected "
1564 			"vnode association ip %p vp %p\n", ip, ip->vp);
1565 		ip->vp->v_data = NULL;
1566 		ip->vp = NULL;
1567 	} else {
1568 		hammer_ref(&ip->lock);
1569 	}
1570 	hammer_unload_inode(ip);
1571 	return(0);
1572 }
1573 
1574 /*
1575  * Called on mount -u when switching from RW to RO or vise-versa.  Adjust
1576  * the read-only flag for cached inodes.
1577  *
1578  * This routine is called from a RB_SCAN().
1579  */
1580 int
1581 hammer_reload_inode(hammer_inode_t ip, void *arg __unused)
1582 {
1583 	hammer_mount_t hmp = ip->hmp;
1584 
1585 	if (hmp->ronly || hmp->asof != HAMMER_MAX_TID)
1586 		ip->flags |= HAMMER_INODE_RO;
1587 	else
1588 		ip->flags &= ~HAMMER_INODE_RO;
1589 	return(0);
1590 }
1591 
1592 /*
1593  * A transaction has modified an inode, requiring updates as specified by
1594  * the passed flags.
1595  *
1596  * HAMMER_INODE_DDIRTY: Inode data has been updated, not incl mtime/atime,
1597  *			and not including size changes due to write-append
1598  *			(but other size changes are included).
1599  * HAMMER_INODE_SDIRTY: Inode data has been updated, size changes due to
1600  *			write-append.
1601  * HAMMER_INODE_XDIRTY: Dirty in-memory records
1602  * HAMMER_INODE_BUFS:   Dirty buffer cache buffers
1603  * HAMMER_INODE_DELETED: Inode record/data must be deleted
1604  * HAMMER_INODE_ATIME/MTIME: mtime/atime has been updated
1605  */
1606 void
1607 hammer_modify_inode(hammer_transaction_t trans, hammer_inode_t ip, int flags)
1608 {
1609 	/*
1610 	 * ronly of 0 or 2 does not trigger assertion.
1611 	 * 2 is a special error state
1612 	 */
1613 	KKASSERT(ip->hmp->ronly != 1 ||
1614 		  (flags & (HAMMER_INODE_DDIRTY | HAMMER_INODE_XDIRTY |
1615 			    HAMMER_INODE_SDIRTY |
1616 			    HAMMER_INODE_BUFS | HAMMER_INODE_DELETED |
1617 			    HAMMER_INODE_ATIME | HAMMER_INODE_MTIME)) == 0);
1618 	if ((ip->flags & HAMMER_INODE_RSV_INODES) == 0) {
1619 		ip->flags |= HAMMER_INODE_RSV_INODES;
1620 		++ip->hmp->rsv_inodes;
1621 	}
1622 
1623 	/*
1624 	 * Set the NEWINODE flag in the transaction if the inode
1625 	 * transitions to a dirty state.  This is used to track
1626 	 * the load on the inode cache.
1627 	 */
1628 	if (trans &&
1629 	    (ip->flags & HAMMER_INODE_MODMASK) == 0 &&
1630 	    (flags & HAMMER_INODE_MODMASK)) {
1631 		trans->flags |= HAMMER_TRANSF_NEWINODE;
1632 	}
1633 
1634 	ip->flags |= flags;
1635 }
1636 
1637 /*
1638  * Attempt to quickly update the atime for a hammer inode.  Return 0 on
1639  * success, -1 on failure.
1640  *
1641  * We attempt to update the atime with only the ip lock and not the
1642  * whole filesystem lock in order to improve concurrency.  We can only
1643  * do this safely if the ATIME flag is already pending on the inode.
1644  *
1645  * This function is called via a vnops path (ip pointer is stable) without
1646  * fs_token held.
1647  */
1648 int
1649 hammer_update_atime_quick(hammer_inode_t ip)
1650 {
1651 	struct timeval tv;
1652 	int res = -1;
1653 
1654 	if ((ip->flags & HAMMER_INODE_RO) ||
1655 	    (ip->hmp->mp->mnt_flag & MNT_NOATIME)) {
1656 		/*
1657 		 * Silently indicate success on read-only mount/snap
1658 		 */
1659 		res = 0;
1660 	} else if (ip->flags & HAMMER_INODE_ATIME) {
1661 		/*
1662 		 * Double check with inode lock held against backend.  This
1663 		 * is only safe if all we need to do is update
1664 		 * ino_data.atime.
1665 		 */
1666 		getmicrotime(&tv);
1667 		hammer_lock_ex(&ip->lock);
1668 		if (ip->flags & HAMMER_INODE_ATIME) {
1669 			ip->ino_data.atime =
1670 			    (unsigned long)tv.tv_sec * 1000000ULL + tv.tv_usec;
1671 			res = 0;
1672 		}
1673 		hammer_unlock(&ip->lock);
1674 	}
1675 	return res;
1676 }
1677 
1678 /*
1679  * Request that an inode be flushed.  This whole mess cannot block and may
1680  * recurse (if not synchronous).  Once requested HAMMER will attempt to
1681  * actively flush the inode until the flush can be done.
1682  *
1683  * The inode may already be flushing, or may be in a setup state.  We can
1684  * place the inode in a flushing state if it is currently idle and flag it
1685  * to reflush if it is currently flushing.
1686  *
1687  * Upon return if the inode could not be flushed due to a setup
1688  * dependancy, then it will be automatically flushed when the dependancy
1689  * is satisfied.
1690  */
1691 void
1692 hammer_flush_inode(hammer_inode_t ip, int flags)
1693 {
1694 	hammer_mount_t hmp;
1695 	hammer_flush_group_t flg;
1696 	int good;
1697 
1698 	/*
1699 	 * fill_flush_group is the first flush group we may be able to
1700 	 * continue filling, it may be open or closed but it will always
1701 	 * be past the currently flushing (running) flg.
1702 	 *
1703 	 * next_flush_group is the next open flush group.
1704 	 */
1705 	hmp = ip->hmp;
1706 	while ((flg = hmp->fill_flush_group) != NULL) {
1707 		KKASSERT(flg->running == 0);
1708 		if (flg->total_count + flg->refs <= ip->hmp->undo_rec_limit &&
1709 		    flg->total_count <= hammer_autoflush) {
1710 			break;
1711 		}
1712 		hmp->fill_flush_group = TAILQ_NEXT(flg, flush_entry);
1713 		hammer_flusher_async(ip->hmp, flg);
1714 	}
1715 	if (flg == NULL) {
1716 		flg = kmalloc(sizeof(*flg), hmp->m_misc, M_WAITOK|M_ZERO);
1717 		flg->seq = hmp->flusher.next++;
1718 		if (hmp->next_flush_group == NULL)
1719 			hmp->next_flush_group = flg;
1720 		if (hmp->fill_flush_group == NULL)
1721 			hmp->fill_flush_group = flg;
1722 		RB_INIT(&flg->flush_tree);
1723 		TAILQ_INSERT_TAIL(&hmp->flush_group_list, flg, flush_entry);
1724 	}
1725 
1726 	/*
1727 	 * Trivial 'nothing to flush' case.  If the inode is in a SETUP
1728 	 * state we have to put it back into an IDLE state so we can
1729 	 * drop the extra ref.
1730 	 *
1731 	 * If we have a parent dependancy we must still fall through
1732 	 * so we can run it.
1733 	 */
1734 	if ((ip->flags & HAMMER_INODE_MODMASK) == 0) {
1735 		if (ip->flush_state == HAMMER_FST_SETUP &&
1736 		    TAILQ_EMPTY(&ip->target_list)) {
1737 			ip->flush_state = HAMMER_FST_IDLE;
1738 			hammer_rel_inode(ip, 0);
1739 		}
1740 		if (ip->flush_state == HAMMER_FST_IDLE)
1741 			return;
1742 	}
1743 
1744 	/*
1745 	 * Our flush action will depend on the current state.
1746 	 */
1747 	switch(ip->flush_state) {
1748 	case HAMMER_FST_IDLE:
1749 		/*
1750 		 * We have no dependancies and can flush immediately.  Some
1751 		 * our children may not be flushable so we have to re-test
1752 		 * with that additional knowledge.
1753 		 */
1754 		hammer_flush_inode_core(ip, flg, flags);
1755 		break;
1756 	case HAMMER_FST_SETUP:
1757 		/*
1758 		 * Recurse upwards through dependancies via target_list
1759 		 * and start their flusher actions going if possible.
1760 		 *
1761 		 * 'good' is our connectivity.  -1 means we have none and
1762 		 * can't flush, 0 means there weren't any dependancies, and
1763 		 * 1 means we have good connectivity.
1764 		 */
1765 		good = hammer_setup_parent_inodes(ip, 0, flg);
1766 
1767 		if (good >= 0) {
1768 			/*
1769 			 * We can continue if good >= 0.  Determine how
1770 			 * many records under our inode can be flushed (and
1771 			 * mark them).
1772 			 */
1773 			hammer_flush_inode_core(ip, flg, flags);
1774 		} else {
1775 			/*
1776 			 * Parent has no connectivity, tell it to flush
1777 			 * us as soon as it does.
1778 			 *
1779 			 * The REFLUSH flag is also needed to trigger
1780 			 * dependancy wakeups.
1781 			 */
1782 			ip->flags |= HAMMER_INODE_CONN_DOWN |
1783 				     HAMMER_INODE_REFLUSH;
1784 			if (flags & HAMMER_FLUSH_SIGNAL) {
1785 				ip->flags |= HAMMER_INODE_RESIGNAL;
1786 				hammer_flusher_async(ip->hmp, flg);
1787 			}
1788 		}
1789 		break;
1790 	case HAMMER_FST_FLUSH:
1791 		/*
1792 		 * We are already flushing, flag the inode to reflush
1793 		 * if needed after it completes its current flush.
1794 		 *
1795 		 * The REFLUSH flag is also needed to trigger
1796 		 * dependancy wakeups.
1797 		 */
1798 		if ((ip->flags & HAMMER_INODE_REFLUSH) == 0)
1799 			ip->flags |= HAMMER_INODE_REFLUSH;
1800 		if (flags & HAMMER_FLUSH_SIGNAL) {
1801 			ip->flags |= HAMMER_INODE_RESIGNAL;
1802 			hammer_flusher_async(ip->hmp, flg);
1803 		}
1804 		break;
1805 	}
1806 }
1807 
1808 /*
1809  * Scan ip->target_list, which is a list of records owned by PARENTS to our
1810  * ip which reference our ip.
1811  *
1812  * XXX This is a huge mess of recursive code, but not one bit of it blocks
1813  *     so for now do not ref/deref the structures.  Note that if we use the
1814  *     ref/rel code later, the rel CAN block.
1815  */
1816 static int
1817 hammer_setup_parent_inodes(hammer_inode_t ip, int depth,
1818 			   hammer_flush_group_t flg)
1819 {
1820 	hammer_record_t depend;
1821 	int good;
1822 	int r;
1823 
1824 	/*
1825 	 * If we hit our recursion limit and we have parent dependencies
1826 	 * We cannot continue.  Returning < 0 will cause us to be flagged
1827 	 * for reflush.  Returning -2 cuts off additional dependency checks
1828 	 * because they are likely to also hit the depth limit.
1829 	 *
1830 	 * We cannot return < 0 if there are no dependencies or there might
1831 	 * not be anything to wakeup (ip).
1832 	 */
1833 	if (depth == 20 && TAILQ_FIRST(&ip->target_list)) {
1834 		kprintf("HAMMER Warning: depth limit reached on "
1835 			"setup recursion, inode %p %016llx\n",
1836 			ip, (long long)ip->obj_id);
1837 		return(-2);
1838 	}
1839 
1840 	/*
1841 	 * Scan dependencies
1842 	 */
1843 	good = 0;
1844 	TAILQ_FOREACH(depend, &ip->target_list, target_entry) {
1845 		r = hammer_setup_parent_inodes_helper(depend, depth, flg);
1846 		KKASSERT(depend->target_ip == ip);
1847 		if (r < 0 && good == 0)
1848 			good = -1;
1849 		if (r > 0)
1850 			good = 1;
1851 
1852 		/*
1853 		 * If we failed due to the recursion depth limit then stop
1854 		 * now.
1855 		 */
1856 		if (r == -2)
1857 			break;
1858 	}
1859 	return(good);
1860 }
1861 
1862 /*
1863  * This helper function takes a record representing the dependancy between
1864  * the parent inode and child inode.
1865  *
1866  * record->ip		= parent inode
1867  * record->target_ip	= child inode
1868  *
1869  * We are asked to recurse upwards and convert the record from SETUP
1870  * to FLUSH if possible.
1871  *
1872  * Return 1 if the record gives us connectivity
1873  *
1874  * Return 0 if the record is not relevant
1875  *
1876  * Return -1 if we can't resolve the dependancy and there is no connectivity.
1877  */
1878 static int
1879 hammer_setup_parent_inodes_helper(hammer_record_t record, int depth,
1880 				  hammer_flush_group_t flg)
1881 {
1882 	hammer_mount_t hmp;
1883 	hammer_inode_t pip;
1884 	int good;
1885 
1886 	KKASSERT(record->flush_state != HAMMER_FST_IDLE);
1887 	pip = record->ip;
1888 	hmp = pip->hmp;
1889 
1890 	/*
1891 	 * If the record is already flushing, is it in our flush group?
1892 	 *
1893 	 * If it is in our flush group but it is a general record or a
1894 	 * delete-on-disk, it does not improve our connectivity (return 0),
1895 	 * and if the target inode is not trying to destroy itself we can't
1896 	 * allow the operation yet anyway (the second return -1).
1897 	 */
1898 	if (record->flush_state == HAMMER_FST_FLUSH) {
1899 		/*
1900 		 * If not in our flush group ask the parent to reflush
1901 		 * us as soon as possible.
1902 		 */
1903 		if (record->flush_group != flg) {
1904 			pip->flags |= HAMMER_INODE_REFLUSH;
1905 			record->target_ip->flags |= HAMMER_INODE_CONN_DOWN;
1906 			return(-1);
1907 		}
1908 
1909 		/*
1910 		 * If in our flush group everything is already set up,
1911 		 * just return whether the record will improve our
1912 		 * visibility or not.
1913 		 */
1914 		if (record->type == HAMMER_MEM_RECORD_ADD)
1915 			return(1);
1916 		return(0);
1917 	}
1918 
1919 	/*
1920 	 * It must be a setup record.  Try to resolve the setup dependancies
1921 	 * by recursing upwards so we can place ip on the flush list.
1922 	 *
1923 	 * Limit ourselves to 20 levels of recursion to avoid blowing out
1924 	 * the kernel stack.  If we hit the recursion limit we can't flush
1925 	 * until the parent flushes.  The parent will flush independantly
1926 	 * on its own and ultimately a deep recursion will be resolved.
1927 	 */
1928 	KKASSERT(record->flush_state == HAMMER_FST_SETUP);
1929 
1930 	good = hammer_setup_parent_inodes(pip, depth + 1, flg);
1931 
1932 	/*
1933 	 * If good < 0 the parent has no connectivity and we cannot safely
1934 	 * flush the directory entry, which also means we can't flush our
1935 	 * ip.  Flag us for downward recursion once the parent's
1936 	 * connectivity is resolved.  Flag the parent for [re]flush or it
1937 	 * may not check for downward recursions.
1938 	 */
1939 	if (good < 0) {
1940 		pip->flags |= HAMMER_INODE_REFLUSH;
1941 		record->target_ip->flags |= HAMMER_INODE_CONN_DOWN;
1942 		return(good);
1943 	}
1944 
1945 	/*
1946 	 * We are go, place the parent inode in a flushing state so we can
1947 	 * place its record in a flushing state.  Note that the parent
1948 	 * may already be flushing.  The record must be in the same flush
1949 	 * group as the parent.
1950 	 */
1951 	if (pip->flush_state != HAMMER_FST_FLUSH)
1952 		hammer_flush_inode_core(pip, flg, HAMMER_FLUSH_RECURSION);
1953 	KKASSERT(pip->flush_state == HAMMER_FST_FLUSH);
1954 
1955 	/*
1956 	 * It is possible for a rename to create a loop in the recursion
1957 	 * and revisit a record.  This will result in the record being
1958 	 * placed in a flush state unexpectedly.  This check deals with
1959 	 * the case.
1960 	 */
1961 	if (record->flush_state == HAMMER_FST_FLUSH) {
1962 		if (record->type == HAMMER_MEM_RECORD_ADD)
1963 			return(1);
1964 		return(0);
1965 	}
1966 
1967 	KKASSERT(record->flush_state == HAMMER_FST_SETUP);
1968 
1969 #if 0
1970 	if (record->type == HAMMER_MEM_RECORD_DEL &&
1971 	    (record->target_ip->flags & (HAMMER_INODE_DELETED|HAMMER_INODE_DELONDISK)) == 0) {
1972 		/*
1973 		 * Regardless of flushing state we cannot sync this path if the
1974 		 * record represents a delete-on-disk but the target inode
1975 		 * is not ready to sync its own deletion.
1976 		 *
1977 		 * XXX need to count effective nlinks to determine whether
1978 		 * the flush is ok, otherwise removing a hardlink will
1979 		 * just leave the DEL record to rot.
1980 		 */
1981 		record->target_ip->flags |= HAMMER_INODE_REFLUSH;
1982 		return(-1);
1983 	} else
1984 #endif
1985 	if (pip->flush_group == flg) {
1986 		/*
1987 		 * Because we have not calculated nlinks yet we can just
1988 		 * set records to the flush state if the parent is in
1989 		 * the same flush group as we are.
1990 		 */
1991 		record->flush_state = HAMMER_FST_FLUSH;
1992 		record->flush_group = flg;
1993 		++record->flush_group->refs;
1994 		hammer_ref(&record->lock);
1995 
1996 		/*
1997 		 * A general directory-add contributes to our visibility.
1998 		 *
1999 		 * Otherwise it is probably a directory-delete or
2000 		 * delete-on-disk record and does not contribute to our
2001 		 * visbility (but we can still flush it).
2002 		 */
2003 		if (record->type == HAMMER_MEM_RECORD_ADD)
2004 			return(1);
2005 		return(0);
2006 	} else {
2007 		/*
2008 		 * If the parent is not in our flush group we cannot
2009 		 * flush this record yet, there is no visibility.
2010 		 * We tell the parent to reflush and mark ourselves
2011 		 * so the parent knows it should flush us too.
2012 		 */
2013 		pip->flags |= HAMMER_INODE_REFLUSH;
2014 		record->target_ip->flags |= HAMMER_INODE_CONN_DOWN;
2015 		return(-1);
2016 	}
2017 }
2018 
2019 /*
2020  * This is the core routine placing an inode into the FST_FLUSH state.
2021  */
2022 static void
2023 hammer_flush_inode_core(hammer_inode_t ip, hammer_flush_group_t flg, int flags)
2024 {
2025 	hammer_mount_t hmp = ip->hmp;
2026 	int go_count;
2027 
2028 	/*
2029 	 * Set flush state and prevent the flusher from cycling into
2030 	 * the next flush group.  Do not place the ip on the list yet.
2031 	 * Inodes not in the idle state get an extra reference.
2032 	 */
2033 	KKASSERT(ip->flush_state != HAMMER_FST_FLUSH);
2034 	if (ip->flush_state == HAMMER_FST_IDLE)
2035 		hammer_ref(&ip->lock);
2036 	ip->flush_state = HAMMER_FST_FLUSH;
2037 	ip->flush_group = flg;
2038 	++hmp->flusher.group_lock;
2039 	++hmp->count_iqueued;
2040 	++hammer_count_iqueued;
2041 	++flg->total_count;
2042 	hammer_redo_fifo_start_flush(ip);
2043 
2044 #if 0
2045 	/*
2046 	 * We need to be able to vfsync/truncate from the backend.
2047 	 *
2048 	 * XXX Any truncation from the backend will acquire the vnode
2049 	 *     independently.
2050 	 */
2051 	KKASSERT((ip->flags & HAMMER_INODE_VHELD) == 0);
2052 	if (ip->vp && (ip->vp->v_flag & VINACTIVE) == 0) {
2053 		ip->flags |= HAMMER_INODE_VHELD;
2054 		vref(ip->vp);
2055 	}
2056 #endif
2057 
2058 	/*
2059 	 * Figure out how many in-memory records we can actually flush
2060 	 * (not including inode meta-data, buffers, etc).
2061 	 */
2062 	KKASSERT((ip->flags & HAMMER_INODE_WOULDBLOCK) == 0);
2063 	if (flags & HAMMER_FLUSH_RECURSION) {
2064 		/*
2065 		 * If this is a upwards recursion we do not want to
2066 		 * recurse down again!
2067 		 */
2068 		go_count = 1;
2069 #if 0
2070 	} else if (ip->flags & HAMMER_INODE_WOULDBLOCK) {
2071 		/*
2072 		 * No new records are added if we must complete a flush
2073 		 * from a previous cycle, but we do have to move the records
2074 		 * from the previous cycle to the current one.
2075 		 */
2076 #if 0
2077 		go_count = RB_SCAN(hammer_rec_rb_tree, &ip->rec_tree, NULL,
2078 				   hammer_syncgrp_child_callback, NULL);
2079 #endif
2080 		go_count = 1;
2081 #endif
2082 	} else {
2083 		/*
2084 		 * Normal flush, scan records and bring them into the flush.
2085 		 * Directory adds and deletes are usually skipped (they are
2086 		 * grouped with the related inode rather then with the
2087 		 * directory).
2088 		 *
2089 		 * go_count can be negative, which means the scan aborted
2090 		 * due to the flush group being over-full and we should
2091 		 * flush what we have.
2092 		 */
2093 		go_count = RB_SCAN(hammer_rec_rb_tree, &ip->rec_tree, NULL,
2094 				   hammer_setup_child_callback, NULL);
2095 	}
2096 
2097 	/*
2098 	 * This is a more involved test that includes go_count.  If we
2099 	 * can't flush, flag the inode and return.  If go_count is 0 we
2100 	 * were are unable to flush any records in our rec_tree and
2101 	 * must ignore the XDIRTY flag.
2102 	 */
2103 	if (go_count == 0) {
2104 		if ((ip->flags & HAMMER_INODE_MODMASK_NOXDIRTY) == 0) {
2105 			--hmp->count_iqueued;
2106 			--hammer_count_iqueued;
2107 
2108 			--flg->total_count;
2109 			ip->flush_state = HAMMER_FST_SETUP;
2110 			ip->flush_group = NULL;
2111 			if (flags & HAMMER_FLUSH_SIGNAL) {
2112 				ip->flags |= HAMMER_INODE_REFLUSH |
2113 					     HAMMER_INODE_RESIGNAL;
2114 			} else {
2115 				ip->flags |= HAMMER_INODE_REFLUSH;
2116 			}
2117 #if 0
2118 			if (ip->flags & HAMMER_INODE_VHELD) {
2119 				ip->flags &= ~HAMMER_INODE_VHELD;
2120 				vrele(ip->vp);
2121 			}
2122 #endif
2123 
2124 			/*
2125 			 * REFLUSH is needed to trigger dependancy wakeups
2126 			 * when an inode is in SETUP.
2127 			 */
2128 			ip->flags |= HAMMER_INODE_REFLUSH;
2129 			if (--hmp->flusher.group_lock == 0)
2130 				wakeup(&hmp->flusher.group_lock);
2131 			return;
2132 		}
2133 	}
2134 
2135 	/*
2136 	 * Snapshot the state of the inode for the backend flusher.
2137 	 *
2138 	 * We continue to retain save_trunc_off even when all truncations
2139 	 * have been resolved as an optimization to determine if we can
2140 	 * skip the B-Tree lookup for overwrite deletions.
2141 	 *
2142 	 * NOTE: The DELETING flag is a mod flag, but it is also sticky,
2143 	 * and stays in ip->flags.  Once set, it stays set until the
2144 	 * inode is destroyed.
2145 	 */
2146 	if (ip->flags & HAMMER_INODE_TRUNCATED) {
2147 		KKASSERT((ip->sync_flags & HAMMER_INODE_TRUNCATED) == 0);
2148 		ip->sync_trunc_off = ip->trunc_off;
2149 		ip->trunc_off = 0x7FFFFFFFFFFFFFFFLL;
2150 		ip->flags &= ~HAMMER_INODE_TRUNCATED;
2151 		ip->sync_flags |= HAMMER_INODE_TRUNCATED;
2152 
2153 		/*
2154 		 * The save_trunc_off used to cache whether the B-Tree
2155 		 * holds any records past that point is not used until
2156 		 * after the truncation has succeeded, so we can safely
2157 		 * set it now.
2158 		 */
2159 		if (ip->save_trunc_off > ip->sync_trunc_off)
2160 			ip->save_trunc_off = ip->sync_trunc_off;
2161 	}
2162 	ip->sync_flags |= (ip->flags & HAMMER_INODE_MODMASK &
2163 			   ~HAMMER_INODE_TRUNCATED);
2164 	ip->sync_ino_leaf = ip->ino_leaf;
2165 	ip->sync_ino_data = ip->ino_data;
2166 	ip->flags &= ~HAMMER_INODE_MODMASK | HAMMER_INODE_TRUNCATED;
2167 #ifdef DEBUG_TRUNCATE
2168 	if ((ip->sync_flags & HAMMER_INODE_TRUNCATED) && ip == HammerTruncIp)
2169 		kprintf("truncateS %016llx\n", ip->sync_trunc_off);
2170 #endif
2171 
2172 	/*
2173 	 * The flusher list inherits our inode and reference.
2174 	 */
2175 	KKASSERT(flg->running == 0);
2176 	RB_INSERT(hammer_fls_rb_tree, &flg->flush_tree, ip);
2177 	if (--hmp->flusher.group_lock == 0)
2178 		wakeup(&hmp->flusher.group_lock);
2179 
2180 	/*
2181 	 * Auto-flush the group if it grows too large.  Make sure the
2182 	 * inode reclaim wait pipeline continues to work.
2183 	 */
2184 	if (flg->total_count >= hammer_autoflush ||
2185 	    flg->total_count >= hammer_limit_reclaims / 4) {
2186 		if (hmp->fill_flush_group == flg)
2187 			hmp->fill_flush_group = TAILQ_NEXT(flg, flush_entry);
2188 		hammer_flusher_async(hmp, flg);
2189 	}
2190 }
2191 
2192 /*
2193  * Callback for scan of ip->rec_tree.  Try to include each record in our
2194  * flush.  ip->flush_group has been set but the inode has not yet been
2195  * moved into a flushing state.
2196  *
2197  * If we get stuck on a record we have to set HAMMER_INODE_REFLUSH on
2198  * both inodes.
2199  *
2200  * We return 1 for any record placed or found in FST_FLUSH, which prevents
2201  * the caller from shortcutting the flush.
2202  */
2203 static int
2204 hammer_setup_child_callback(hammer_record_t rec, void *data)
2205 {
2206 	hammer_flush_group_t flg;
2207 	hammer_inode_t target_ip;
2208 	hammer_inode_t ip;
2209 	int r;
2210 
2211 	/*
2212 	 * Records deleted or committed by the backend are ignored.
2213 	 * Note that the flush detects deleted frontend records at
2214 	 * multiple points to deal with races.  This is just the first
2215 	 * line of defense.  The only time HAMMER_RECF_DELETED_FE cannot
2216 	 * be set is when HAMMER_RECF_INTERLOCK_BE is set, because it
2217 	 * messes up link-count calculations.
2218 	 *
2219 	 * NOTE: Don't get confused between record deletion and, say,
2220 	 * directory entry deletion.  The deletion of a directory entry
2221 	 * which is on-media has nothing to do with the record deletion
2222 	 * flags.
2223 	 */
2224 	if (rec->flags & (HAMMER_RECF_DELETED_FE | HAMMER_RECF_DELETED_BE |
2225 			  HAMMER_RECF_COMMITTED)) {
2226 		if (rec->flush_state == HAMMER_FST_FLUSH) {
2227 			KKASSERT(rec->flush_group == rec->ip->flush_group);
2228 			r = 1;
2229 		} else {
2230 			r = 0;
2231 		}
2232 		return(r);
2233 	}
2234 
2235 	/*
2236 	 * If the record is in an idle state it has no dependancies and
2237 	 * can be flushed.
2238 	 */
2239 	ip = rec->ip;
2240 	flg = ip->flush_group;
2241 	r = 0;
2242 
2243 	switch(rec->flush_state) {
2244 	case HAMMER_FST_IDLE:
2245 		/*
2246 		 * The record has no setup dependancy, we can flush it.
2247 		 */
2248 		KKASSERT(rec->target_ip == NULL);
2249 		rec->flush_state = HAMMER_FST_FLUSH;
2250 		rec->flush_group = flg;
2251 		++flg->refs;
2252 		hammer_ref(&rec->lock);
2253 		r = 1;
2254 		break;
2255 	case HAMMER_FST_SETUP:
2256 		/*
2257 		 * The record has a setup dependancy.  These are typically
2258 		 * directory entry adds and deletes.  Such entries will be
2259 		 * flushed when their inodes are flushed so we do not
2260 		 * usually have to add them to the flush here.  However,
2261 		 * if the target_ip has set HAMMER_INODE_CONN_DOWN then
2262 		 * it is asking us to flush this record (and it).
2263 		 */
2264 		target_ip = rec->target_ip;
2265 		KKASSERT(target_ip != NULL);
2266 		KKASSERT(target_ip->flush_state != HAMMER_FST_IDLE);
2267 
2268 		/*
2269 		 * If the target IP is already flushing in our group
2270 		 * we could associate the record, but target_ip has
2271 		 * already synced ino_data to sync_ino_data and we
2272 		 * would also have to adjust nlinks.   Plus there are
2273 		 * ordering issues for adds and deletes.
2274 		 *
2275 		 * Reflush downward if this is an ADD, and upward if
2276 		 * this is a DEL.
2277 		 */
2278 		if (target_ip->flush_state == HAMMER_FST_FLUSH) {
2279 			if (rec->type == HAMMER_MEM_RECORD_ADD)
2280 				ip->flags |= HAMMER_INODE_REFLUSH;
2281 			else
2282 				target_ip->flags |= HAMMER_INODE_REFLUSH;
2283 			break;
2284 		}
2285 
2286 		/*
2287 		 * Target IP is not yet flushing.  This can get complex
2288 		 * because we have to be careful about the recursion.
2289 		 *
2290 		 * Directories create an issue for us in that if a flush
2291 		 * of a directory is requested the expectation is to flush
2292 		 * any pending directory entries, but this will cause the
2293 		 * related inodes to recursively flush as well.  We can't
2294 		 * really defer the operation so just get as many as we
2295 		 * can and
2296 		 */
2297 #if 0
2298 		if ((target_ip->flags & HAMMER_INODE_RECLAIM) == 0 &&
2299 		    (target_ip->flags & HAMMER_INODE_CONN_DOWN) == 0) {
2300 			/*
2301 			 * We aren't reclaiming and the target ip was not
2302 			 * previously prevented from flushing due to this
2303 			 * record dependancy.  Do not flush this record.
2304 			 */
2305 			/*r = 0;*/
2306 		} else
2307 #endif
2308 		if (flg->total_count + flg->refs >
2309 			   ip->hmp->undo_rec_limit) {
2310 			/*
2311 			 * Our flush group is over-full and we risk blowing
2312 			 * out the UNDO FIFO.  Stop the scan, flush what we
2313 			 * have, then reflush the directory.
2314 			 *
2315 			 * The directory may be forced through multiple
2316 			 * flush groups before it can be completely
2317 			 * flushed.
2318 			 */
2319 			ip->flags |= HAMMER_INODE_RESIGNAL |
2320 				     HAMMER_INODE_REFLUSH;
2321 			r = -1;
2322 		} else if (rec->type == HAMMER_MEM_RECORD_ADD) {
2323 			/*
2324 			 * If the target IP is not flushing we can force
2325 			 * it to flush, even if it is unable to write out
2326 			 * any of its own records we have at least one in
2327 			 * hand that we CAN deal with.
2328 			 */
2329 			rec->flush_state = HAMMER_FST_FLUSH;
2330 			rec->flush_group = flg;
2331 			++flg->refs;
2332 			hammer_ref(&rec->lock);
2333 			hammer_flush_inode_core(target_ip, flg,
2334 						HAMMER_FLUSH_RECURSION);
2335 			r = 1;
2336 		} else {
2337 			/*
2338 			 * General or delete-on-disk record.
2339 			 *
2340 			 * XXX this needs help.  If a delete-on-disk we could
2341 			 * disconnect the target.  If the target has its own
2342 			 * dependancies they really need to be flushed.
2343 			 *
2344 			 * XXX
2345 			 */
2346 			rec->flush_state = HAMMER_FST_FLUSH;
2347 			rec->flush_group = flg;
2348 			++flg->refs;
2349 			hammer_ref(&rec->lock);
2350 			hammer_flush_inode_core(target_ip, flg,
2351 						HAMMER_FLUSH_RECURSION);
2352 			r = 1;
2353 		}
2354 		break;
2355 	case HAMMER_FST_FLUSH:
2356 		/*
2357 		 * The record could be part of a previous flush group if the
2358 		 * inode is a directory (the record being a directory entry).
2359 		 * Once the flush group was closed a hammer_test_inode()
2360 		 * function can cause a new flush group to be setup, placing
2361 		 * the directory inode itself in a new flush group.
2362 		 *
2363 		 * When associated with a previous flush group we count it
2364 		 * as if it were in our current flush group, since it will
2365 		 * effectively be flushed by the time we flush our current
2366 		 * flush group.
2367 		 */
2368 		KKASSERT(
2369 		    rec->ip->ino_data.obj_type == HAMMER_OBJTYPE_DIRECTORY ||
2370 		    rec->flush_group == flg);
2371 		r = 1;
2372 		break;
2373 	}
2374 	return(r);
2375 }
2376 
2377 #if 0
2378 /*
2379  * This version just moves records already in a flush state to the new
2380  * flush group and that is it.
2381  */
2382 static int
2383 hammer_syncgrp_child_callback(hammer_record_t rec, void *data)
2384 {
2385 	hammer_inode_t ip = rec->ip;
2386 
2387 	switch(rec->flush_state) {
2388 	case HAMMER_FST_FLUSH:
2389 		KKASSERT(rec->flush_group == ip->flush_group);
2390 		break;
2391 	default:
2392 		break;
2393 	}
2394 	return(0);
2395 }
2396 #endif
2397 
2398 /*
2399  * Wait for a previously queued flush to complete.
2400  *
2401  * If a critical error occured we don't try to wait.
2402  */
2403 void
2404 hammer_wait_inode(hammer_inode_t ip)
2405 {
2406 	hammer_flush_group_t flg;
2407 
2408 	flg = NULL;
2409 
2410 	/*
2411 	 * The inode can be in a SETUP state in which case RESIGNAL
2412 	 * should be set.  If RESIGNAL is not set then the previous
2413 	 * flush completed and a later operation placed the inode
2414 	 * in a passive setup state again, so we're done.
2415 	 *
2416 	 * The inode can be in a FLUSH state in which case we
2417 	 * can just wait for completion.
2418 	 */
2419 	while (ip->flush_state == HAMMER_FST_FLUSH ||
2420 	    (ip->flush_state == HAMMER_FST_SETUP &&
2421 	     (ip->flags & HAMMER_INODE_RESIGNAL))) {
2422 		/*
2423 		 * Don't try to flush on a critical error
2424 		 */
2425 		if (ip->hmp->flags & HAMMER_MOUNT_CRITICAL_ERROR)
2426 			break;
2427 
2428 		/*
2429 		 * If the inode was already being flushed its flg
2430 		 * may not have been queued to the backend.  We
2431 		 * have to make sure it gets queued or we can wind
2432 		 * up blocked or deadlocked (particularly if we are
2433 		 * the vnlru thread).
2434 		 */
2435 		if (ip->flush_state == HAMMER_FST_FLUSH) {
2436 			KKASSERT(ip->flush_group);
2437 			if (ip->flush_group->closed == 0) {
2438 				kprintf("hammer: debug: forcing async "
2439 					"flush ip %016jx\n",
2440 					(intmax_t)ip->obj_id);
2441 				hammer_flusher_async(ip->hmp,
2442 						     ip->flush_group);
2443 				continue; /* retest */
2444 			}
2445 		}
2446 
2447 		/*
2448 		 * In a flush state with the flg queued to the backend
2449 		 * or in a setup state with RESIGNAL set, we can safely
2450 		 * wait.
2451 		 */
2452 		ip->flags |= HAMMER_INODE_FLUSHW;
2453 		tsleep(&ip->flags, 0, "hmrwin", 0);
2454 	}
2455 
2456 #if 0
2457 	/*
2458 	 * The inode may have been in a passive setup state,
2459 	 * call flush to make sure we get signaled.
2460 	 */
2461 	if (ip->flush_state == HAMMER_FST_SETUP)
2462 		hammer_flush_inode(ip, HAMMER_FLUSH_SIGNAL);
2463 #endif
2464 
2465 }
2466 
2467 /*
2468  * Called by the backend code when a flush has been completed.
2469  * The inode has already been removed from the flush list.
2470  *
2471  * A pipelined flush can occur, in which case we must re-enter the
2472  * inode on the list and re-copy its fields.
2473  */
2474 void
2475 hammer_flush_inode_done(hammer_inode_t ip, int error)
2476 {
2477 	hammer_mount_t hmp;
2478 	int dorel;
2479 
2480 	KKASSERT(ip->flush_state == HAMMER_FST_FLUSH);
2481 
2482 	hmp = ip->hmp;
2483 
2484 	/*
2485 	 * Auto-reflush if the backend could not completely flush
2486 	 * the inode.  This fixes a case where a deferred buffer flush
2487 	 * could cause fsync to return early.
2488 	 */
2489 	if (ip->sync_flags & HAMMER_INODE_MODMASK)
2490 		ip->flags |= HAMMER_INODE_REFLUSH;
2491 
2492 	/*
2493 	 * Merge left-over flags back into the frontend and fix the state.
2494 	 * Incomplete truncations are retained by the backend.
2495 	 */
2496 	ip->error = error;
2497 	ip->flags |= ip->sync_flags & ~HAMMER_INODE_TRUNCATED;
2498 	ip->sync_flags &= HAMMER_INODE_TRUNCATED;
2499 
2500 	/*
2501 	 * The backend may have adjusted nlinks, so if the adjusted nlinks
2502 	 * does not match the fronttend set the frontend's DDIRTY flag again.
2503 	 */
2504 	if (ip->ino_data.nlinks != ip->sync_ino_data.nlinks)
2505 		ip->flags |= HAMMER_INODE_DDIRTY;
2506 
2507 	/*
2508 	 * Fix up the dirty buffer status.
2509 	 */
2510 	if (ip->vp && RB_ROOT(&ip->vp->v_rbdirty_tree)) {
2511 		ip->flags |= HAMMER_INODE_BUFS;
2512 	}
2513 	hammer_redo_fifo_end_flush(ip);
2514 
2515 	/*
2516 	 * Re-set the XDIRTY flag if some of the inode's in-memory records
2517 	 * could not be flushed.
2518 	 */
2519 	KKASSERT((RB_EMPTY(&ip->rec_tree) &&
2520 		  (ip->flags & HAMMER_INODE_XDIRTY) == 0) ||
2521 		 (!RB_EMPTY(&ip->rec_tree) &&
2522 		  (ip->flags & HAMMER_INODE_XDIRTY) != 0));
2523 
2524 	/*
2525 	 * Do not lose track of inodes which no longer have vnode
2526 	 * assocations, otherwise they may never get flushed again.
2527 	 *
2528 	 * The reflush flag can be set superfluously, causing extra pain
2529 	 * for no reason.  If the inode is no longer modified it no longer
2530 	 * needs to be flushed.
2531 	 */
2532 	if (ip->flags & HAMMER_INODE_MODMASK) {
2533 		if (ip->vp == NULL)
2534 			ip->flags |= HAMMER_INODE_REFLUSH;
2535 	} else {
2536 		ip->flags &= ~HAMMER_INODE_REFLUSH;
2537 	}
2538 
2539 	/*
2540 	 * Adjust the flush state.
2541 	 */
2542 	if (ip->flags & HAMMER_INODE_WOULDBLOCK) {
2543 		/*
2544 		 * We were unable to flush out all our records, leave the
2545 		 * inode in a flush state and in the current flush group.
2546 		 * The flush group will be re-run.
2547 		 *
2548 		 * This occurs if the UNDO block gets too full or there is
2549 		 * too much dirty meta-data and allows the flusher to
2550 		 * finalize the UNDO block and then re-flush.
2551 		 */
2552 		ip->flags &= ~HAMMER_INODE_WOULDBLOCK;
2553 		dorel = 0;
2554 	} else {
2555 		/*
2556 		 * Remove from the flush_group
2557 		 */
2558 		RB_REMOVE(hammer_fls_rb_tree, &ip->flush_group->flush_tree, ip);
2559 		ip->flush_group = NULL;
2560 
2561 #if 0
2562 		/*
2563 		 * Clean up the vnode ref and tracking counts.
2564 		 */
2565 		if (ip->flags & HAMMER_INODE_VHELD) {
2566 			ip->flags &= ~HAMMER_INODE_VHELD;
2567 			vrele(ip->vp);
2568 		}
2569 #endif
2570 		--hmp->count_iqueued;
2571 		--hammer_count_iqueued;
2572 
2573 		/*
2574 		 * And adjust the state.
2575 		 */
2576 		if (TAILQ_EMPTY(&ip->target_list) && RB_EMPTY(&ip->rec_tree)) {
2577 			ip->flush_state = HAMMER_FST_IDLE;
2578 			dorel = 1;
2579 		} else {
2580 			ip->flush_state = HAMMER_FST_SETUP;
2581 			dorel = 0;
2582 		}
2583 
2584 		/*
2585 		 * If the frontend is waiting for a flush to complete,
2586 		 * wake it up.
2587 		 */
2588 		if (ip->flags & HAMMER_INODE_FLUSHW) {
2589 			ip->flags &= ~HAMMER_INODE_FLUSHW;
2590 			wakeup(&ip->flags);
2591 		}
2592 
2593 		/*
2594 		 * If the frontend made more changes and requested another
2595 		 * flush, then try to get it running.
2596 		 *
2597 		 * Reflushes are aborted when the inode is errored out.
2598 		 */
2599 		if (ip->flags & HAMMER_INODE_REFLUSH) {
2600 			ip->flags &= ~HAMMER_INODE_REFLUSH;
2601 			if (ip->flags & HAMMER_INODE_RESIGNAL) {
2602 				ip->flags &= ~HAMMER_INODE_RESIGNAL;
2603 				hammer_flush_inode(ip, HAMMER_FLUSH_SIGNAL);
2604 			} else {
2605 				hammer_flush_inode(ip, 0);
2606 			}
2607 		}
2608 	}
2609 
2610 	/*
2611 	 * If we have no parent dependancies we can clear CONN_DOWN
2612 	 */
2613 	if (TAILQ_EMPTY(&ip->target_list))
2614 		ip->flags &= ~HAMMER_INODE_CONN_DOWN;
2615 
2616 	/*
2617 	 * If the inode is now clean drop the space reservation.
2618 	 */
2619 	if ((ip->flags & HAMMER_INODE_MODMASK) == 0 &&
2620 	    (ip->flags & HAMMER_INODE_RSV_INODES)) {
2621 		ip->flags &= ~HAMMER_INODE_RSV_INODES;
2622 		--hmp->rsv_inodes;
2623 	}
2624 
2625 	ip->flags &= ~HAMMER_INODE_SLAVEFLUSH;
2626 
2627 	if (dorel)
2628 		hammer_rel_inode(ip, 0);
2629 }
2630 
2631 /*
2632  * Called from hammer_sync_inode() to synchronize in-memory records
2633  * to the media.
2634  */
2635 static int
2636 hammer_sync_record_callback(hammer_record_t record, void *data)
2637 {
2638 	hammer_cursor_t cursor = data;
2639 	hammer_transaction_t trans = cursor->trans;
2640 	hammer_mount_t hmp = trans->hmp;
2641 	int error;
2642 
2643 	/*
2644 	 * Skip records that do not belong to the current flush.
2645 	 */
2646 	++hammer_stats_record_iterations;
2647 	if (record->flush_state != HAMMER_FST_FLUSH)
2648 		return(0);
2649 
2650 #if 1
2651 	if (record->flush_group != record->ip->flush_group) {
2652 		kprintf("sync_record %p ip %p bad flush group %p %p\n", record, record->ip, record->flush_group ,record->ip->flush_group);
2653 		if (hammer_debug_critical)
2654 			Debugger("blah2");
2655 		return(0);
2656 	}
2657 #endif
2658 	KKASSERT(record->flush_group == record->ip->flush_group);
2659 
2660 	/*
2661 	 * Interlock the record using the BE flag.  Once BE is set the
2662 	 * frontend cannot change the state of FE.
2663 	 *
2664 	 * NOTE: If FE is set prior to us setting BE we still sync the
2665 	 * record out, but the flush completion code converts it to
2666 	 * a delete-on-disk record instead of destroying it.
2667 	 */
2668 	KKASSERT((record->flags & HAMMER_RECF_INTERLOCK_BE) == 0);
2669 	record->flags |= HAMMER_RECF_INTERLOCK_BE;
2670 
2671 	/*
2672 	 * The backend has already disposed of the record.
2673 	 */
2674 	if (record->flags & (HAMMER_RECF_DELETED_BE | HAMMER_RECF_COMMITTED)) {
2675 		error = 0;
2676 		goto done;
2677 	}
2678 
2679 	/*
2680 	 * If the whole inode is being deleted and all on-disk records will
2681 	 * be deleted very soon, we can't sync any new records to disk
2682 	 * because they will be deleted in the same transaction they were
2683 	 * created in (delete_tid == create_tid), which will assert.
2684 	 *
2685 	 * XXX There may be a case with RECORD_ADD with DELETED_FE set
2686 	 * that we currently panic on.
2687 	 */
2688 	if (record->ip->sync_flags & HAMMER_INODE_DELETING) {
2689 		switch(record->type) {
2690 		case HAMMER_MEM_RECORD_DATA:
2691 			/*
2692 			 * We don't have to do anything, if the record was
2693 			 * committed the space will have been accounted for
2694 			 * in the blockmap.
2695 			 */
2696 			/* fall through */
2697 		case HAMMER_MEM_RECORD_GENERAL:
2698 			/*
2699 			 * Set deleted-by-backend flag.  Do not set the
2700 			 * backend committed flag, because we are throwing
2701 			 * the record away.
2702 			 */
2703 			record->flags |= HAMMER_RECF_DELETED_BE;
2704 			++record->ip->rec_generation;
2705 			error = 0;
2706 			goto done;
2707 		case HAMMER_MEM_RECORD_ADD:
2708 			panic("hammer_sync_record_callback: illegal add "
2709 			      "during inode deletion record %p", record);
2710 			break; /* NOT REACHED */
2711 		case HAMMER_MEM_RECORD_INODE:
2712 			panic("hammer_sync_record_callback: attempt to "
2713 			      "sync inode record %p?", record);
2714 			break; /* NOT REACHED */
2715 		case HAMMER_MEM_RECORD_DEL:
2716 			/*
2717 			 * Follow through and issue the on-disk deletion
2718 			 */
2719 			break;
2720 		}
2721 	}
2722 
2723 	/*
2724 	 * If DELETED_FE is set special handling is needed for directory
2725 	 * entries.  Dependant pieces related to the directory entry may
2726 	 * have already been synced to disk.  If this occurs we have to
2727 	 * sync the directory entry and then change the in-memory record
2728 	 * from an ADD to a DELETE to cover the fact that it's been
2729 	 * deleted by the frontend.
2730 	 *
2731 	 * A directory delete covering record (MEM_RECORD_DEL) can never
2732 	 * be deleted by the frontend.
2733 	 *
2734 	 * Any other record type (aka DATA) can be deleted by the frontend.
2735 	 * XXX At the moment the flusher must skip it because there may
2736 	 * be another data record in the flush group for the same block,
2737 	 * meaning that some frontend data changes can leak into the backend's
2738 	 * synchronization point.
2739 	 */
2740 	if (record->flags & HAMMER_RECF_DELETED_FE) {
2741 		if (record->type == HAMMER_MEM_RECORD_ADD) {
2742 			/*
2743 			 * Convert a front-end deleted directory-add to
2744 			 * a directory-delete entry later.
2745 			 */
2746 			record->flags |= HAMMER_RECF_CONVERT_DELETE;
2747 		} else {
2748 			/*
2749 			 * Dispose of the record (race case).  Mark as
2750 			 * deleted by backend (and not committed).
2751 			 */
2752 			KKASSERT(record->type != HAMMER_MEM_RECORD_DEL);
2753 			record->flags |= HAMMER_RECF_DELETED_BE;
2754 			++record->ip->rec_generation;
2755 			error = 0;
2756 			goto done;
2757 		}
2758 	}
2759 
2760 	/*
2761 	 * Assign the create_tid for new records.  Deletions already
2762 	 * have the record's entire key properly set up.
2763 	 */
2764 	if (record->type != HAMMER_MEM_RECORD_DEL) {
2765 		record->leaf.base.create_tid = trans->tid;
2766 		record->leaf.create_ts = trans->time32;
2767 	}
2768 
2769 	/*
2770 	 * This actually moves the record to the on-media B-Tree.  We
2771 	 * must also generate REDO_TERM entries in the UNDO/REDO FIFO
2772 	 * indicating that the related REDO_WRITE(s) have been committed.
2773 	 *
2774 	 * During recovery any REDO_TERM's within the nominal recovery span
2775 	 * are ignored since the related meta-data is being undone, causing
2776 	 * any matching REDO_WRITEs to execute.  The REDO_TERMs outside
2777 	 * the nominal recovery span will match against REDO_WRITEs and
2778 	 * prevent them from being executed (because the meta-data has
2779 	 * already been synchronized).
2780 	 */
2781 	if (record->flags & HAMMER_RECF_REDO) {
2782 		KKASSERT(record->type == HAMMER_MEM_RECORD_DATA);
2783 		hammer_generate_redo(trans, record->ip,
2784 				     record->leaf.base.key -
2785 					 record->leaf.data_len,
2786 				     HAMMER_REDO_TERM_WRITE,
2787 				     NULL,
2788 				     record->leaf.data_len);
2789 	}
2790 	for (;;) {
2791 		error = hammer_ip_sync_record_cursor(cursor, record);
2792 		if (error != EDEADLK)
2793 			break;
2794 		hammer_done_cursor(cursor);
2795 		error = hammer_init_cursor(trans, cursor, &record->ip->cache[0],
2796 					   record->ip);
2797 		if (error)
2798 			break;
2799 	}
2800 	record->flags &= ~HAMMER_RECF_CONVERT_DELETE;
2801 
2802 	if (error)
2803 		error = -error;
2804 done:
2805 	hammer_flush_record_done(record, error);
2806 
2807 	/*
2808 	 * Do partial finalization if we have built up too many dirty
2809 	 * buffers.  Otherwise a buffer cache deadlock can occur when
2810 	 * doing things like creating tens of thousands of tiny files.
2811 	 *
2812 	 * We must release our cursor lock to avoid a 3-way deadlock
2813 	 * due to the exclusive sync lock the finalizer must get.
2814 	 *
2815 	 * WARNING: See warnings in hammer_unlock_cursor() function.
2816 	 */
2817         if (hammer_flusher_meta_limit(hmp)) {
2818 		hammer_unlock_cursor(cursor);
2819                 hammer_flusher_finalize(trans, 0);
2820 		hammer_lock_cursor(cursor);
2821 	}
2822 
2823 	return(error);
2824 }
2825 
2826 /*
2827  * Backend function called by the flusher to sync an inode to media.
2828  */
2829 int
2830 hammer_sync_inode(hammer_transaction_t trans, hammer_inode_t ip)
2831 {
2832 	struct hammer_cursor cursor;
2833 	hammer_node_t tmp_node;
2834 	hammer_record_t depend;
2835 	hammer_record_t next;
2836 	int error, tmp_error;
2837 	u_int64_t nlinks;
2838 
2839 	if ((ip->sync_flags & HAMMER_INODE_MODMASK) == 0)
2840 		return(0);
2841 
2842 	error = hammer_init_cursor(trans, &cursor, &ip->cache[1], ip);
2843 	if (error)
2844 		goto done;
2845 
2846 	/*
2847 	 * Any directory records referencing this inode which are not in
2848 	 * our current flush group must adjust our nlink count for the
2849 	 * purposes of synchronizating to disk.
2850 	 *
2851 	 * Records which are in our flush group can be unlinked from our
2852 	 * inode now, potentially allowing the inode to be physically
2853 	 * deleted.
2854 	 *
2855 	 * This cannot block.
2856 	 */
2857 	nlinks = ip->ino_data.nlinks;
2858 	next = TAILQ_FIRST(&ip->target_list);
2859 	while ((depend = next) != NULL) {
2860 		next = TAILQ_NEXT(depend, target_entry);
2861 		if (depend->flush_state == HAMMER_FST_FLUSH &&
2862 		    depend->flush_group == ip->flush_group) {
2863 			/*
2864 			 * If this is an ADD that was deleted by the frontend
2865 			 * the frontend nlinks count will have already been
2866 			 * decremented, but the backend is going to sync its
2867 			 * directory entry and must account for it.  The
2868 			 * record will be converted to a delete-on-disk when
2869 			 * it gets synced.
2870 			 *
2871 			 * If the ADD was not deleted by the frontend we
2872 			 * can remove the dependancy from our target_list.
2873 			 */
2874 			if (depend->flags & HAMMER_RECF_DELETED_FE) {
2875 				++nlinks;
2876 			} else {
2877 				TAILQ_REMOVE(&ip->target_list, depend,
2878 					     target_entry);
2879 				depend->target_ip = NULL;
2880 			}
2881 		} else if ((depend->flags & HAMMER_RECF_DELETED_FE) == 0) {
2882 			/*
2883 			 * Not part of our flush group and not deleted by
2884 			 * the front-end, adjust the link count synced to
2885 			 * the media (undo what the frontend did when it
2886 			 * queued the record).
2887 			 */
2888 			KKASSERT((depend->flags & HAMMER_RECF_DELETED_BE) == 0);
2889 			switch(depend->type) {
2890 			case HAMMER_MEM_RECORD_ADD:
2891 				--nlinks;
2892 				break;
2893 			case HAMMER_MEM_RECORD_DEL:
2894 				++nlinks;
2895 				break;
2896 			default:
2897 				break;
2898 			}
2899 		}
2900 	}
2901 
2902 	/*
2903 	 * Set dirty if we had to modify the link count.
2904 	 */
2905 	if (ip->sync_ino_data.nlinks != nlinks) {
2906 		KKASSERT((int64_t)nlinks >= 0);
2907 		ip->sync_ino_data.nlinks = nlinks;
2908 		ip->sync_flags |= HAMMER_INODE_DDIRTY;
2909 	}
2910 
2911 	/*
2912 	 * If there is a trunction queued destroy any data past the (aligned)
2913 	 * truncation point.  Userland will have dealt with the buffer
2914 	 * containing the truncation point for us.
2915 	 *
2916 	 * We don't flush pending frontend data buffers until after we've
2917 	 * dealt with the truncation.
2918 	 */
2919 	if (ip->sync_flags & HAMMER_INODE_TRUNCATED) {
2920 		/*
2921 		 * Interlock trunc_off.  The VOP front-end may continue to
2922 		 * make adjustments to it while we are blocked.
2923 		 */
2924 		off_t trunc_off;
2925 		off_t aligned_trunc_off;
2926 		int blkmask;
2927 
2928 		trunc_off = ip->sync_trunc_off;
2929 		blkmask = hammer_blocksize(trunc_off) - 1;
2930 		aligned_trunc_off = (trunc_off + blkmask) & ~(int64_t)blkmask;
2931 
2932 		/*
2933 		 * Delete any whole blocks on-media.  The front-end has
2934 		 * already cleaned out any partial block and made it
2935 		 * pending.  The front-end may have updated trunc_off
2936 		 * while we were blocked so we only use sync_trunc_off.
2937 		 *
2938 		 * This operation can blow out the buffer cache, EWOULDBLOCK
2939 		 * means we were unable to complete the deletion.  The
2940 		 * deletion will update sync_trunc_off in that case.
2941 		 */
2942 		error = hammer_ip_delete_range(&cursor, ip,
2943 						aligned_trunc_off,
2944 						0x7FFFFFFFFFFFFFFFLL, 2);
2945 		if (error == EWOULDBLOCK) {
2946 			ip->flags |= HAMMER_INODE_WOULDBLOCK;
2947 			error = 0;
2948 			goto defer_buffer_flush;
2949 		}
2950 
2951 		if (error)
2952 			goto done;
2953 
2954 		/*
2955 		 * Generate a REDO_TERM_TRUNC entry in the UNDO/REDO FIFO.
2956 		 *
2957 		 * XXX we do this even if we did not previously generate
2958 		 * a REDO_TRUNC record.  This operation may enclosed the
2959 		 * range for multiple prior truncation entries in the REDO
2960 		 * log.
2961 		 */
2962 		if (trans->hmp->version >= HAMMER_VOL_VERSION_FOUR &&
2963 		    (ip->flags & HAMMER_INODE_RDIRTY)) {
2964 			hammer_generate_redo(trans, ip, aligned_trunc_off,
2965 					     HAMMER_REDO_TERM_TRUNC,
2966 					     NULL, 0);
2967 		}
2968 
2969 		/*
2970 		 * Clear the truncation flag on the backend after we have
2971 		 * completed the deletions.  Backend data is now good again
2972 		 * (including new records we are about to sync, below).
2973 		 *
2974 		 * Leave sync_trunc_off intact.  As we write additional
2975 		 * records the backend will update sync_trunc_off.  This
2976 		 * tells the backend whether it can skip the overwrite
2977 		 * test.  This should work properly even when the backend
2978 		 * writes full blocks where the truncation point straddles
2979 		 * the block because the comparison is against the base
2980 		 * offset of the record.
2981 		 */
2982 		ip->sync_flags &= ~HAMMER_INODE_TRUNCATED;
2983 		/* ip->sync_trunc_off = 0x7FFFFFFFFFFFFFFFLL; */
2984 	} else {
2985 		error = 0;
2986 	}
2987 
2988 	/*
2989 	 * Now sync related records.  These will typically be directory
2990 	 * entries, records tracking direct-writes, or delete-on-disk records.
2991 	 */
2992 	if (error == 0) {
2993 		tmp_error = RB_SCAN(hammer_rec_rb_tree, &ip->rec_tree, NULL,
2994 				    hammer_sync_record_callback, &cursor);
2995 		if (tmp_error < 0)
2996 			tmp_error = -error;
2997 		if (tmp_error)
2998 			error = tmp_error;
2999 	}
3000 	hammer_cache_node(&ip->cache[1], cursor.node);
3001 
3002 	/*
3003 	 * Re-seek for inode update, assuming our cache hasn't been ripped
3004 	 * out from under us.
3005 	 */
3006 	if (error == 0) {
3007 		tmp_node = hammer_ref_node_safe(trans, &ip->cache[0], &error);
3008 		if (tmp_node) {
3009 			hammer_cursor_downgrade(&cursor);
3010 			hammer_lock_sh(&tmp_node->lock);
3011 			if ((tmp_node->flags & HAMMER_NODE_DELETED) == 0)
3012 				hammer_cursor_seek(&cursor, tmp_node, 0);
3013 			hammer_unlock(&tmp_node->lock);
3014 			hammer_rel_node(tmp_node);
3015 		}
3016 		error = 0;
3017 	}
3018 
3019 	/*
3020 	 * If we are deleting the inode the frontend had better not have
3021 	 * any active references on elements making up the inode.
3022 	 *
3023 	 * The call to hammer_ip_delete_clean() cleans up auxillary records
3024 	 * but not DB or DATA records.  Those must have already been deleted
3025 	 * by the normal truncation mechanic.
3026 	 */
3027 	if (error == 0 && ip->sync_ino_data.nlinks == 0 &&
3028 		RB_EMPTY(&ip->rec_tree)  &&
3029 	    (ip->sync_flags & HAMMER_INODE_DELETING) &&
3030 	    (ip->flags & HAMMER_INODE_DELETED) == 0) {
3031 		int count1 = 0;
3032 
3033 		error = hammer_ip_delete_clean(&cursor, ip, &count1);
3034 		if (error == 0) {
3035 			ip->flags |= HAMMER_INODE_DELETED;
3036 			ip->sync_flags &= ~HAMMER_INODE_DELETING;
3037 			ip->sync_flags &= ~HAMMER_INODE_TRUNCATED;
3038 			KKASSERT(RB_EMPTY(&ip->rec_tree));
3039 
3040 			/*
3041 			 * Set delete_tid in both the frontend and backend
3042 			 * copy of the inode record.  The DELETED flag handles
3043 			 * this, do not set DDIRTY.
3044 			 */
3045 			ip->ino_leaf.base.delete_tid = trans->tid;
3046 			ip->sync_ino_leaf.base.delete_tid = trans->tid;
3047 			ip->ino_leaf.delete_ts = trans->time32;
3048 			ip->sync_ino_leaf.delete_ts = trans->time32;
3049 
3050 
3051 			/*
3052 			 * Adjust the inode count in the volume header
3053 			 */
3054 			hammer_sync_lock_sh(trans);
3055 			if (ip->flags & HAMMER_INODE_ONDISK) {
3056 				hammer_modify_volume_field(trans,
3057 							   trans->rootvol,
3058 							   vol0_stat_inodes);
3059 				--ip->hmp->rootvol->ondisk->vol0_stat_inodes;
3060 				hammer_modify_volume_done(trans->rootvol);
3061 			}
3062 			hammer_sync_unlock(trans);
3063 		}
3064 	}
3065 
3066 	if (error)
3067 		goto done;
3068 	ip->sync_flags &= ~HAMMER_INODE_BUFS;
3069 
3070 defer_buffer_flush:
3071 	/*
3072 	 * Now update the inode's on-disk inode-data and/or on-disk record.
3073 	 * DELETED and ONDISK are managed only in ip->flags.
3074 	 *
3075 	 * In the case of a defered buffer flush we still update the on-disk
3076 	 * inode to satisfy visibility requirements if there happen to be
3077 	 * directory dependancies.
3078 	 */
3079 	switch(ip->flags & (HAMMER_INODE_DELETED | HAMMER_INODE_ONDISK)) {
3080 	case HAMMER_INODE_DELETED|HAMMER_INODE_ONDISK:
3081 		/*
3082 		 * If deleted and on-disk, don't set any additional flags.
3083 		 * the delete flag takes care of things.
3084 		 *
3085 		 * Clear flags which may have been set by the frontend.
3086 		 */
3087 		ip->sync_flags &= ~(HAMMER_INODE_DDIRTY | HAMMER_INODE_XDIRTY |
3088 				    HAMMER_INODE_SDIRTY |
3089 				    HAMMER_INODE_ATIME | HAMMER_INODE_MTIME |
3090 				    HAMMER_INODE_DELETING);
3091 		break;
3092 	case HAMMER_INODE_DELETED:
3093 		/*
3094 		 * Take care of the case where a deleted inode was never
3095 		 * flushed to the disk in the first place.
3096 		 *
3097 		 * Clear flags which may have been set by the frontend.
3098 		 */
3099 		ip->sync_flags &= ~(HAMMER_INODE_DDIRTY | HAMMER_INODE_XDIRTY |
3100 				    HAMMER_INODE_SDIRTY |
3101 				    HAMMER_INODE_ATIME | HAMMER_INODE_MTIME |
3102 				    HAMMER_INODE_DELETING);
3103 		while (RB_ROOT(&ip->rec_tree)) {
3104 			hammer_record_t record = RB_ROOT(&ip->rec_tree);
3105 			hammer_ref(&record->lock);
3106 			KKASSERT(hammer_oneref(&record->lock));
3107 			record->flags |= HAMMER_RECF_DELETED_BE;
3108 			++record->ip->rec_generation;
3109 			hammer_rel_mem_record(record);
3110 		}
3111 		break;
3112 	case HAMMER_INODE_ONDISK:
3113 		/*
3114 		 * If already on-disk, do not set any additional flags.
3115 		 */
3116 		break;
3117 	default:
3118 		/*
3119 		 * If not on-disk and not deleted, set DDIRTY to force
3120 		 * an initial record to be written.
3121 		 *
3122 		 * Also set the create_tid in both the frontend and backend
3123 		 * copy of the inode record.
3124 		 */
3125 		ip->ino_leaf.base.create_tid = trans->tid;
3126 		ip->ino_leaf.create_ts = trans->time32;
3127 		ip->sync_ino_leaf.base.create_tid = trans->tid;
3128 		ip->sync_ino_leaf.create_ts = trans->time32;
3129 		ip->sync_flags |= HAMMER_INODE_DDIRTY;
3130 		break;
3131 	}
3132 
3133 	/*
3134 	 * If DDIRTY or SDIRTY is set, write out a new record.
3135 	 * If the inode is already on-disk the old record is marked as
3136 	 * deleted.
3137 	 *
3138 	 * If DELETED is set hammer_update_inode() will delete the existing
3139 	 * record without writing out a new one.
3140 	 *
3141 	 * If *ONLY* the ITIMES flag is set we can update the record in-place.
3142 	 */
3143 	if (ip->flags & HAMMER_INODE_DELETED) {
3144 		error = hammer_update_inode(&cursor, ip);
3145 	} else
3146 	if (!(ip->sync_flags & (HAMMER_INODE_DDIRTY | HAMMER_INODE_SDIRTY)) &&
3147 	    (ip->sync_flags & (HAMMER_INODE_ATIME | HAMMER_INODE_MTIME))) {
3148 		error = hammer_update_itimes(&cursor, ip);
3149 	} else
3150 	if (ip->sync_flags & (HAMMER_INODE_DDIRTY | HAMMER_INODE_SDIRTY |
3151 			      HAMMER_INODE_ATIME | HAMMER_INODE_MTIME)) {
3152 		error = hammer_update_inode(&cursor, ip);
3153 	}
3154 done:
3155 	if (error) {
3156 		hammer_critical_error(ip->hmp, ip, error,
3157 				      "while syncing inode");
3158 	}
3159 	hammer_done_cursor(&cursor);
3160 	return(error);
3161 }
3162 
3163 /*
3164  * This routine is called when the OS is no longer actively referencing
3165  * the inode (but might still be keeping it cached), or when releasing
3166  * the last reference to an inode.
3167  *
3168  * At this point if the inode's nlinks count is zero we want to destroy
3169  * it, which may mean destroying it on-media too.
3170  */
3171 void
3172 hammer_inode_unloadable_check(hammer_inode_t ip, int getvp)
3173 {
3174 	struct vnode *vp;
3175 
3176 	/*
3177 	 * Set the DELETING flag when the link count drops to 0 and the
3178 	 * OS no longer has any opens on the inode.
3179 	 *
3180 	 * The backend will clear DELETING (a mod flag) and set DELETED
3181 	 * (a state flag) when it is actually able to perform the
3182 	 * operation.
3183 	 *
3184 	 * Don't reflag the deletion if the flusher is currently syncing
3185 	 * one that was already flagged.  A previously set DELETING flag
3186 	 * may bounce around flags and sync_flags until the operation is
3187 	 * completely done.
3188 	 *
3189 	 * Do not attempt to modify a snapshot inode (one set to read-only).
3190 	 */
3191 	if (ip->ino_data.nlinks == 0 &&
3192 	    ((ip->flags | ip->sync_flags) & (HAMMER_INODE_RO|HAMMER_INODE_DELETING|HAMMER_INODE_DELETED)) == 0) {
3193 		ip->flags |= HAMMER_INODE_DELETING;
3194 		ip->flags |= HAMMER_INODE_TRUNCATED;
3195 		ip->trunc_off = 0;
3196 		vp = NULL;
3197 		if (getvp) {
3198 			if (hammer_get_vnode(ip, &vp) != 0)
3199 				return;
3200 		}
3201 
3202 		/*
3203 		 * Final cleanup
3204 		 */
3205 		if (ip->vp)
3206 			nvtruncbuf(ip->vp, 0, HAMMER_BUFSIZE, 0);
3207 		if (getvp)
3208 			vput(vp);
3209 	}
3210 }
3211 
3212 /*
3213  * After potentially resolving a dependancy the inode is tested
3214  * to determine whether it needs to be reflushed.
3215  */
3216 void
3217 hammer_test_inode(hammer_inode_t ip)
3218 {
3219 	if (ip->flags & HAMMER_INODE_REFLUSH) {
3220 		ip->flags &= ~HAMMER_INODE_REFLUSH;
3221 		hammer_ref(&ip->lock);
3222 		if (ip->flags & HAMMER_INODE_RESIGNAL) {
3223 			ip->flags &= ~HAMMER_INODE_RESIGNAL;
3224 			hammer_flush_inode(ip, HAMMER_FLUSH_SIGNAL);
3225 		} else {
3226 			hammer_flush_inode(ip, 0);
3227 		}
3228 		hammer_rel_inode(ip, 0);
3229 	}
3230 }
3231 
3232 /*
3233  * Clear the RECLAIM flag on an inode.  This occurs when the inode is
3234  * reassociated with a vp or just before it gets freed.
3235  *
3236  * Pipeline wakeups to threads blocked due to an excessive number of
3237  * detached inodes.  This typically occurs when atime updates accumulate
3238  * while scanning a directory tree.
3239  */
3240 static void
3241 hammer_inode_wakereclaims(hammer_inode_t ip)
3242 {
3243 	struct hammer_reclaim *reclaim;
3244 	hammer_mount_t hmp = ip->hmp;
3245 
3246 	if ((ip->flags & HAMMER_INODE_RECLAIM) == 0)
3247 		return;
3248 
3249 	--hammer_count_reclaims;
3250 	--hmp->count_reclaims;
3251 	ip->flags &= ~HAMMER_INODE_RECLAIM;
3252 
3253 	if ((reclaim = TAILQ_FIRST(&hmp->reclaim_list)) != NULL) {
3254 		KKASSERT(reclaim->count > 0);
3255 		if (--reclaim->count == 0) {
3256 			TAILQ_REMOVE(&hmp->reclaim_list, reclaim, entry);
3257 			wakeup(reclaim);
3258 		}
3259 	}
3260 }
3261 
3262 /*
3263  * Setup our reclaim pipeline.  We only let so many detached (and dirty)
3264  * inodes build up before we start blocking.  This routine is called
3265  * if a new inode is created or an inode is loaded from media.
3266  *
3267  * When we block we don't care *which* inode has finished reclaiming,
3268  * as long as one does.
3269  *
3270  * The reclaim pipeline is primarily governed by the auto-flush which is
3271  * 1/4 hammer_limit_reclaims.  We don't want to block if the count is
3272  * less than 1/2 hammer_limit_reclaims.  From 1/2 to full count is
3273  * dynamically governed.
3274  */
3275 void
3276 hammer_inode_waitreclaims(hammer_transaction_t trans)
3277 {
3278 	hammer_mount_t hmp = trans->hmp;
3279 	struct hammer_reclaim reclaim;
3280 	int lower_limit;
3281 
3282 	/*
3283 	 * Track inode load, delay if the number of reclaiming inodes is
3284 	 * between 2/4 and 4/4 hammer_limit_reclaims, depending.
3285 	 */
3286 	if (curthread->td_proc) {
3287 		struct hammer_inostats *stats;
3288 
3289 		stats = hammer_inode_inostats(hmp, curthread->td_proc->p_pid);
3290 		++stats->count;
3291 
3292 		if (stats->count > hammer_limit_reclaims / 2)
3293 			stats->count = hammer_limit_reclaims / 2;
3294 		lower_limit = hammer_limit_reclaims - stats->count;
3295 		if (hammer_debug_general & 0x10000) {
3296 			kprintf("pid %5d limit %d\n",
3297 				(int)curthread->td_proc->p_pid, lower_limit);
3298 		}
3299 	} else {
3300 		lower_limit = hammer_limit_reclaims * 3 / 4;
3301 	}
3302 	if (hmp->count_reclaims >= lower_limit) {
3303 		reclaim.count = 1;
3304 		TAILQ_INSERT_TAIL(&hmp->reclaim_list, &reclaim, entry);
3305 		tsleep(&reclaim, 0, "hmrrcm", hz);
3306 		if (reclaim.count > 0)
3307 			TAILQ_REMOVE(&hmp->reclaim_list, &reclaim, entry);
3308 	}
3309 }
3310 
3311 /*
3312  * Keep track of reclaim statistics on a per-pid basis using a loose
3313  * 4-way set associative hash table.  Collisions inherit the count of
3314  * the previous entry.
3315  *
3316  * NOTE: We want to be careful here to limit the chain size.  If the chain
3317  *	 size is too large a pid will spread its stats out over too many
3318  *	 entries under certain types of heavy filesystem activity and
3319  *	 wind up not delaying long enough.
3320  */
3321 static
3322 struct hammer_inostats *
3323 hammer_inode_inostats(hammer_mount_t hmp, pid_t pid)
3324 {
3325 	struct hammer_inostats *stats;
3326 	int delta;
3327 	int chain;
3328 	static volatile int iterator;	/* we don't care about MP races */
3329 
3330 	/*
3331 	 * Chain up to 4 times to find our entry.
3332 	 */
3333 	for (chain = 0; chain < 4; ++chain) {
3334 		stats = &hmp->inostats[(pid + chain) & HAMMER_INOSTATS_HMASK];
3335 		if (stats->pid == pid)
3336 			break;
3337 	}
3338 
3339 	/*
3340 	 * Replace one of the four chaining entries with our new entry.
3341 	 */
3342 	if (chain == 4) {
3343 		stats = &hmp->inostats[(pid + (iterator++ & 3)) &
3344 				       HAMMER_INOSTATS_HMASK];
3345 		stats->pid = pid;
3346 	}
3347 
3348 	/*
3349 	 * Decay the entry
3350 	 */
3351 	if (stats->count && stats->ltick != ticks) {
3352 		delta = ticks - stats->ltick;
3353 		stats->ltick = ticks;
3354 		if (delta <= 0 || delta > hz * 60)
3355 			stats->count = 0;
3356 		else
3357 			stats->count = stats->count * hz / (hz + delta);
3358 	}
3359 	if (hammer_debug_general & 0x10000)
3360 		kprintf("pid %5d stats %d\n", (int)pid, stats->count);
3361 	return (stats);
3362 }
3363 
3364 #if 0
3365 
3366 /*
3367  * XXX not used, doesn't work very well due to the large batching nature
3368  * of flushes.
3369  *
3370  * A larger then normal backlog of inodes is sitting in the flusher,
3371  * enforce a general slowdown to let it catch up.  This routine is only
3372  * called on completion of a non-flusher-related transaction which
3373  * performed B-Tree node I/O.
3374  *
3375  * It is possible for the flusher to stall in a continuous load.
3376  * blogbench -i1000 -o seems to do a good job generating this sort of load.
3377  * If the flusher is unable to catch up the inode count can bloat until
3378  * we run out of kvm.
3379  *
3380  * This is a bit of a hack.
3381  */
3382 void
3383 hammer_inode_waithard(hammer_mount_t hmp)
3384 {
3385 	/*
3386 	 * Hysteresis.
3387 	 */
3388 	if (hmp->flags & HAMMER_MOUNT_FLUSH_RECOVERY) {
3389 		if (hmp->count_reclaims < hammer_limit_reclaims / 2 &&
3390 		    hmp->count_iqueued < hmp->count_inodes / 20) {
3391 			hmp->flags &= ~HAMMER_MOUNT_FLUSH_RECOVERY;
3392 			return;
3393 		}
3394 	} else {
3395 		if (hmp->count_reclaims < hammer_limit_reclaims ||
3396 		    hmp->count_iqueued < hmp->count_inodes / 10) {
3397 			return;
3398 		}
3399 		hmp->flags |= HAMMER_MOUNT_FLUSH_RECOVERY;
3400 	}
3401 
3402 	/*
3403 	 * Block for one flush cycle.
3404 	 */
3405 	hammer_flusher_wait_next(hmp);
3406 }
3407 
3408 #endif
3409