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