xref: /dragonfly/sys/vfs/ufs/ffs_softdep.c (revision d600454b)
1 /*
2  * Copyright 1998, 2000 Marshall Kirk McKusick. All Rights Reserved.
3  *
4  * The soft updates code is derived from the appendix of a University
5  * of Michigan technical report (Gregory R. Ganger and Yale N. Patt,
6  * "Soft Updates: A Solution to the Metadata Update Problem in File
7  * Systems", CSE-TR-254-95, August 1995).
8  *
9  * Further information about soft updates can be obtained from:
10  *
11  *	Marshall Kirk McKusick		http://www.mckusick.com/softdep/
12  *	1614 Oxford Street		mckusick@mckusick.com
13  *	Berkeley, CA 94709-1608		+1-510-843-9542
14  *	USA
15  *
16  * Redistribution and use in source and binary forms, with or without
17  * modification, are permitted provided that the following conditions
18  * are met:
19  *
20  * 1. Redistributions of source code must retain the above copyright
21  *    notice, this list of conditions and the following disclaimer.
22  * 2. Redistributions in binary form must reproduce the above copyright
23  *    notice, this list of conditions and the following disclaimer in the
24  *    documentation and/or other materials provided with the distribution.
25  *
26  * THIS SOFTWARE IS PROVIDED BY MARSHALL KIRK MCKUSICK ``AS IS'' AND ANY
27  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
28  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
29  * DISCLAIMED.  IN NO EVENT SHALL MARSHALL KIRK MCKUSICK BE LIABLE FOR
30  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  *
38  *	from: @(#)ffs_softdep.c	9.59 (McKusick) 6/21/00
39  * $FreeBSD: src/sys/ufs/ffs/ffs_softdep.c,v 1.57.2.11 2002/02/05 18:46:53 dillon Exp $
40  * $DragonFly: src/sys/vfs/ufs/ffs_softdep.c,v 1.34 2006/02/17 19:18:08 dillon Exp $
41  */
42 
43 /*
44  * For now we want the safety net that the DIAGNOSTIC and DEBUG flags provide.
45  */
46 #ifndef DIAGNOSTIC
47 #define DIAGNOSTIC
48 #endif
49 #ifndef DEBUG
50 #define DEBUG
51 #endif
52 
53 #include <sys/param.h>
54 #include <sys/kernel.h>
55 #include <sys/systm.h>
56 #include <sys/buf.h>
57 #include <sys/malloc.h>
58 #include <sys/mount.h>
59 #include <sys/proc.h>
60 #include <sys/syslog.h>
61 #include <sys/vnode.h>
62 #include <sys/conf.h>
63 #include <sys/buf2.h>
64 #include <machine/inttypes.h>
65 #include "dir.h"
66 #include "quota.h"
67 #include "inode.h"
68 #include "ufsmount.h"
69 #include "fs.h"
70 #include "softdep.h"
71 #include "ffs_extern.h"
72 #include "ufs_extern.h"
73 
74 #include <sys/thread2.h>
75 
76 /*
77  * These definitions need to be adapted to the system to which
78  * this file is being ported.
79  */
80 /*
81  * malloc types defined for the softdep system.
82  */
83 MALLOC_DEFINE(M_PAGEDEP, "pagedep","File page dependencies");
84 MALLOC_DEFINE(M_INODEDEP, "inodedep","Inode dependencies");
85 MALLOC_DEFINE(M_NEWBLK, "newblk","New block allocation");
86 MALLOC_DEFINE(M_BMSAFEMAP, "bmsafemap","Block or frag allocated from cyl group map");
87 MALLOC_DEFINE(M_ALLOCDIRECT, "allocdirect","Block or frag dependency for an inode");
88 MALLOC_DEFINE(M_INDIRDEP, "indirdep","Indirect block dependencies");
89 MALLOC_DEFINE(M_ALLOCINDIR, "allocindir","Block dependency for an indirect block");
90 MALLOC_DEFINE(M_FREEFRAG, "freefrag","Previously used frag for an inode");
91 MALLOC_DEFINE(M_FREEBLKS, "freeblks","Blocks freed from an inode");
92 MALLOC_DEFINE(M_FREEFILE, "freefile","Inode deallocated");
93 MALLOC_DEFINE(M_DIRADD, "diradd","New directory entry");
94 MALLOC_DEFINE(M_MKDIR, "mkdir","New directory");
95 MALLOC_DEFINE(M_DIRREM, "dirrem","Directory entry deleted");
96 
97 #define M_SOFTDEP_FLAGS		(M_WAITOK | M_USE_RESERVE)
98 
99 #define	D_PAGEDEP	0
100 #define	D_INODEDEP	1
101 #define	D_NEWBLK	2
102 #define	D_BMSAFEMAP	3
103 #define	D_ALLOCDIRECT	4
104 #define	D_INDIRDEP	5
105 #define	D_ALLOCINDIR	6
106 #define	D_FREEFRAG	7
107 #define	D_FREEBLKS	8
108 #define	D_FREEFILE	9
109 #define	D_DIRADD	10
110 #define	D_MKDIR		11
111 #define	D_DIRREM	12
112 #define D_LAST		D_DIRREM
113 
114 /*
115  * translate from workitem type to memory type
116  * MUST match the defines above, such that memtype[D_XXX] == M_XXX
117  */
118 static struct malloc_type *memtype[] = {
119 	M_PAGEDEP,
120 	M_INODEDEP,
121 	M_NEWBLK,
122 	M_BMSAFEMAP,
123 	M_ALLOCDIRECT,
124 	M_INDIRDEP,
125 	M_ALLOCINDIR,
126 	M_FREEFRAG,
127 	M_FREEBLKS,
128 	M_FREEFILE,
129 	M_DIRADD,
130 	M_MKDIR,
131 	M_DIRREM
132 };
133 
134 #define DtoM(type) (memtype[type])
135 
136 /*
137  * Names of malloc types.
138  */
139 #define TYPENAME(type)  \
140 	((unsigned)(type) < D_LAST ? memtype[type]->ks_shortdesc : "???")
141 /*
142  * End system adaptaion definitions.
143  */
144 
145 /*
146  * Internal function prototypes.
147  */
148 static	void softdep_error(char *, int);
149 static	void drain_output(struct vnode *, int);
150 static	int getdirtybuf(struct buf **, int);
151 static	void clear_remove(struct thread *);
152 static	void clear_inodedeps(struct thread *);
153 static	int flush_pagedep_deps(struct vnode *, struct mount *,
154 	    struct diraddhd *);
155 static	int flush_inodedep_deps(struct fs *, ino_t);
156 static	int handle_written_filepage(struct pagedep *, struct buf *);
157 static  void diradd_inode_written(struct diradd *, struct inodedep *);
158 static	int handle_written_inodeblock(struct inodedep *, struct buf *);
159 static	void handle_allocdirect_partdone(struct allocdirect *);
160 static	void handle_allocindir_partdone(struct allocindir *);
161 static	void initiate_write_filepage(struct pagedep *, struct buf *);
162 static	void handle_written_mkdir(struct mkdir *, int);
163 static	void initiate_write_inodeblock(struct inodedep *, struct buf *);
164 static	void handle_workitem_freefile(struct freefile *);
165 static	void handle_workitem_remove(struct dirrem *);
166 static	struct dirrem *newdirrem(struct buf *, struct inode *,
167 	    struct inode *, int, struct dirrem **);
168 static	void free_diradd(struct diradd *);
169 static	void free_allocindir(struct allocindir *, struct inodedep *);
170 static	int indir_trunc (struct inode *, ufs_daddr_t, int, ufs_lbn_t,
171 	    long *);
172 static	void deallocate_dependencies(struct buf *, struct inodedep *);
173 static	void free_allocdirect(struct allocdirectlst *,
174 	    struct allocdirect *, int);
175 static	int check_inode_unwritten(struct inodedep *);
176 static	int free_inodedep(struct inodedep *);
177 static	void handle_workitem_freeblocks(struct freeblks *);
178 static	void merge_inode_lists(struct inodedep *);
179 static	void setup_allocindir_phase2(struct buf *, struct inode *,
180 	    struct allocindir *);
181 static	struct allocindir *newallocindir(struct inode *, int, ufs_daddr_t,
182 	    ufs_daddr_t);
183 static	void handle_workitem_freefrag(struct freefrag *);
184 static	struct freefrag *newfreefrag(struct inode *, ufs_daddr_t, long);
185 static	void allocdirect_merge(struct allocdirectlst *,
186 	    struct allocdirect *, struct allocdirect *);
187 static	struct bmsafemap *bmsafemap_lookup(struct buf *);
188 static	int newblk_lookup(struct fs *, ufs_daddr_t, int,
189 	    struct newblk **);
190 static	int inodedep_lookup(struct fs *, ino_t, int, struct inodedep **);
191 static	int pagedep_lookup(struct inode *, ufs_lbn_t, int,
192 	    struct pagedep **);
193 static	void pause_timer(void *);
194 static	int request_cleanup(int, int);
195 static	int process_worklist_item(struct mount *, int);
196 static	void add_to_worklist(struct worklist *);
197 
198 /*
199  * Exported softdep operations.
200  */
201 static	void softdep_disk_io_initiation(struct buf *);
202 static	void softdep_disk_write_complete(struct buf *);
203 static	void softdep_deallocate_dependencies(struct buf *);
204 static	int softdep_fsync(struct vnode *);
205 static	int softdep_process_worklist(struct mount *);
206 static	void softdep_move_dependencies(struct buf *, struct buf *);
207 static	int softdep_count_dependencies(struct buf *bp, int);
208 
209 static struct bio_ops softdep_bioops = {
210 	softdep_disk_io_initiation,		/* io_start */
211 	softdep_disk_write_complete,		/* io_complete */
212 	softdep_deallocate_dependencies,	/* io_deallocate */
213 	softdep_fsync,				/* io_fsync */
214 	softdep_process_worklist,		/* io_sync */
215 	softdep_move_dependencies,		/* io_movedeps */
216 	softdep_count_dependencies,		/* io_countdeps */
217 };
218 
219 /*
220  * Locking primitives.
221  *
222  * For a uniprocessor, all we need to do is protect against disk
223  * interrupts. For a multiprocessor, this lock would have to be
224  * a mutex. A single mutex is used throughout this file, though
225  * finer grain locking could be used if contention warranted it.
226  *
227  * For a multiprocessor, the sleep call would accept a lock and
228  * release it after the sleep processing was complete. In a uniprocessor
229  * implementation there is no such interlock, so we simple mark
230  * the places where it needs to be done with the `interlocked' form
231  * of the lock calls. Since the uniprocessor sleep already interlocks
232  * the spl, there is nothing that really needs to be done.
233  */
234 #ifndef /* NOT */ DEBUG
235 static struct lockit {
236 } lk = { 0 };
237 #define ACQUIRE_LOCK(lk)		crit_enter_id("softupdates");
238 #define FREE_LOCK(lk)			crit_exit_id("softupdates");
239 
240 #else /* DEBUG */
241 #define NOHOLDER	((struct thread *)-1)
242 #define SPECIAL_FLAG	((struct thread *)-2)
243 static struct lockit {
244 	int	lkt_spl;
245 	struct thread *lkt_held;
246 } lk = { 0, NOHOLDER };
247 static int lockcnt;
248 
249 static	void acquire_lock(struct lockit *);
250 static	void free_lock(struct lockit *);
251 void	softdep_panic(char *);
252 
253 #define ACQUIRE_LOCK(lk)		acquire_lock(lk)
254 #define FREE_LOCK(lk)			free_lock(lk)
255 
256 static void
257 acquire_lock(lk)
258 	struct lockit *lk;
259 {
260 	thread_t holder;
261 
262 	if (lk->lkt_held != NOHOLDER) {
263 		holder = lk->lkt_held;
264 		FREE_LOCK(lk);
265 		if (holder == curthread)
266 			panic("softdep_lock: locking against myself");
267 		else
268 			panic("softdep_lock: lock held by %p", holder);
269 	}
270 	crit_enter_id("softupdates");
271 	lk->lkt_held = curthread;
272 	lockcnt++;
273 }
274 
275 static void
276 free_lock(lk)
277 	struct lockit *lk;
278 {
279 
280 	if (lk->lkt_held == NOHOLDER)
281 		panic("softdep_unlock: lock not held");
282 	lk->lkt_held = NOHOLDER;
283 	crit_exit_id("softupdates");
284 }
285 
286 /*
287  * Function to release soft updates lock and panic.
288  */
289 void
290 softdep_panic(msg)
291 	char *msg;
292 {
293 
294 	if (lk.lkt_held != NOHOLDER)
295 		FREE_LOCK(&lk);
296 	panic(msg);
297 }
298 #endif /* DEBUG */
299 
300 static	int interlocked_sleep(struct lockit *, int, void *, int,
301 	    const char *, int);
302 
303 /*
304  * When going to sleep, we must save our SPL so that it does
305  * not get lost if some other process uses the lock while we
306  * are sleeping. We restore it after we have slept. This routine
307  * wraps the interlocking with functions that sleep. The list
308  * below enumerates the available set of operations.
309  */
310 #define	UNKNOWN		0
311 #define	SLEEP		1
312 #define	LOCKBUF		2
313 
314 static int
315 interlocked_sleep(lk, op, ident, flags, wmesg, timo)
316 	struct lockit *lk;
317 	int op;
318 	void *ident;
319 	int flags;
320 	const char *wmesg;
321 	int timo;
322 {
323 	thread_t holder;
324 	int s, retval;
325 
326 	s = lk->lkt_spl;
327 #	ifdef DEBUG
328 	if (lk->lkt_held == NOHOLDER)
329 		panic("interlocked_sleep: lock not held");
330 	lk->lkt_held = NOHOLDER;
331 #	endif /* DEBUG */
332 	switch (op) {
333 	case SLEEP:
334 		retval = tsleep(ident, flags, wmesg, timo);
335 		break;
336 	case LOCKBUF:
337 		retval = BUF_LOCK((struct buf *)ident, flags);
338 		break;
339 	default:
340 		panic("interlocked_sleep: unknown operation");
341 	}
342 #	ifdef DEBUG
343 	if (lk->lkt_held != NOHOLDER) {
344 		holder = lk->lkt_held;
345 		FREE_LOCK(lk);
346 		if (holder == curthread)
347 			panic("interlocked_sleep: locking against self");
348 		else
349 			panic("interlocked_sleep: lock held by %p", holder);
350 	}
351 	lk->lkt_held = curthread;
352 	lockcnt++;
353 #	endif /* DEBUG */
354 	lk->lkt_spl = s;
355 	return (retval);
356 }
357 
358 /*
359  * Place holder for real semaphores.
360  */
361 struct sema {
362 	int	value;
363 	thread_t holder;
364 	char	*name;
365 	int	prio;
366 	int	timo;
367 };
368 static	void sema_init(struct sema *, char *, int, int);
369 static	int sema_get(struct sema *, struct lockit *);
370 static	void sema_release(struct sema *);
371 
372 static void
373 sema_init(semap, name, prio, timo)
374 	struct sema *semap;
375 	char *name;
376 	int prio, timo;
377 {
378 
379 	semap->holder = NOHOLDER;
380 	semap->value = 0;
381 	semap->name = name;
382 	semap->prio = prio;
383 	semap->timo = timo;
384 }
385 
386 static int
387 sema_get(semap, interlock)
388 	struct sema *semap;
389 	struct lockit *interlock;
390 {
391 
392 	if (semap->value++ > 0) {
393 		if (interlock != NULL) {
394 			interlocked_sleep(interlock, SLEEP, (caddr_t)semap,
395 			    semap->prio, semap->name, semap->timo);
396 			FREE_LOCK(interlock);
397 		} else {
398 			tsleep((caddr_t)semap, semap->prio, semap->name,
399 			    semap->timo);
400 		}
401 		return (0);
402 	}
403 	semap->holder = curthread;
404 	if (interlock != NULL)
405 		FREE_LOCK(interlock);
406 	return (1);
407 }
408 
409 static void
410 sema_release(semap)
411 	struct sema *semap;
412 {
413 
414 	if (semap->value <= 0 || semap->holder != curthread) {
415 		if (lk.lkt_held != NOHOLDER)
416 			FREE_LOCK(&lk);
417 		panic("sema_release: not held");
418 	}
419 	if (--semap->value > 0) {
420 		semap->value = 0;
421 		wakeup(semap);
422 	}
423 	semap->holder = NOHOLDER;
424 }
425 
426 /*
427  * Worklist queue management.
428  * These routines require that the lock be held.
429  */
430 #ifndef /* NOT */ DEBUG
431 #define WORKLIST_INSERT(head, item) do {	\
432 	(item)->wk_state |= ONWORKLIST;		\
433 	LIST_INSERT_HEAD(head, item, wk_list);	\
434 } while (0)
435 #define WORKLIST_REMOVE(item) do {		\
436 	(item)->wk_state &= ~ONWORKLIST;	\
437 	LIST_REMOVE(item, wk_list);		\
438 } while (0)
439 #define WORKITEM_FREE(item, type) FREE(item, DtoM(type))
440 
441 #else /* DEBUG */
442 static	void worklist_insert(struct workhead *, struct worklist *);
443 static	void worklist_remove(struct worklist *);
444 static	void workitem_free(struct worklist *, int);
445 
446 #define WORKLIST_INSERT(head, item) worklist_insert(head, item)
447 #define WORKLIST_REMOVE(item) worklist_remove(item)
448 #define WORKITEM_FREE(item, type) workitem_free((struct worklist *)item, type)
449 
450 static void
451 worklist_insert(head, item)
452 	struct workhead *head;
453 	struct worklist *item;
454 {
455 
456 	if (lk.lkt_held == NOHOLDER)
457 		panic("worklist_insert: lock not held");
458 	if (item->wk_state & ONWORKLIST) {
459 		FREE_LOCK(&lk);
460 		panic("worklist_insert: already on list");
461 	}
462 	item->wk_state |= ONWORKLIST;
463 	LIST_INSERT_HEAD(head, item, wk_list);
464 }
465 
466 static void
467 worklist_remove(item)
468 	struct worklist *item;
469 {
470 
471 	if (lk.lkt_held == NOHOLDER)
472 		panic("worklist_remove: lock not held");
473 	if ((item->wk_state & ONWORKLIST) == 0) {
474 		FREE_LOCK(&lk);
475 		panic("worklist_remove: not on list");
476 	}
477 	item->wk_state &= ~ONWORKLIST;
478 	LIST_REMOVE(item, wk_list);
479 }
480 
481 static void
482 workitem_free(item, type)
483 	struct worklist *item;
484 	int type;
485 {
486 
487 	if (item->wk_state & ONWORKLIST) {
488 		if (lk.lkt_held != NOHOLDER)
489 			FREE_LOCK(&lk);
490 		panic("workitem_free: still on list");
491 	}
492 	if (item->wk_type != type) {
493 		if (lk.lkt_held != NOHOLDER)
494 			FREE_LOCK(&lk);
495 		panic("workitem_free: type mismatch");
496 	}
497 	FREE(item, DtoM(type));
498 }
499 #endif /* DEBUG */
500 
501 /*
502  * Workitem queue management
503  */
504 static struct workhead softdep_workitem_pending;
505 static int num_on_worklist;	/* number of worklist items to be processed */
506 static int softdep_worklist_busy; /* 1 => trying to do unmount */
507 static int softdep_worklist_req; /* serialized waiters */
508 static int max_softdeps;	/* maximum number of structs before slowdown */
509 static int tickdelay = 2;	/* number of ticks to pause during slowdown */
510 static int *stat_countp;	/* statistic to count in proc_waiting timeout */
511 static int proc_waiting;	/* tracks whether we have a timeout posted */
512 static struct callout handle; /* handle on posted proc_waiting timeout */
513 static struct thread *filesys_syncer; /* proc of filesystem syncer process */
514 static int req_clear_inodedeps;	/* syncer process flush some inodedeps */
515 #define FLUSH_INODES	1
516 static int req_clear_remove;	/* syncer process flush some freeblks */
517 #define FLUSH_REMOVE	2
518 /*
519  * runtime statistics
520  */
521 static int stat_worklist_push;	/* number of worklist cleanups */
522 static int stat_blk_limit_push;	/* number of times block limit neared */
523 static int stat_ino_limit_push;	/* number of times inode limit neared */
524 static int stat_blk_limit_hit;	/* number of times block slowdown imposed */
525 static int stat_ino_limit_hit;	/* number of times inode slowdown imposed */
526 static int stat_sync_limit_hit;	/* number of synchronous slowdowns imposed */
527 static int stat_indir_blk_ptrs;	/* bufs redirtied as indir ptrs not written */
528 static int stat_inode_bitmap;	/* bufs redirtied as inode bitmap not written */
529 static int stat_direct_blk_ptrs;/* bufs redirtied as direct ptrs not written */
530 static int stat_dir_entry;	/* bufs redirtied as dir entry cannot write */
531 #ifdef DEBUG
532 #include <vm/vm.h>
533 #include <sys/sysctl.h>
534 SYSCTL_INT(_debug, OID_AUTO, max_softdeps, CTLFLAG_RW, &max_softdeps, 0, "");
535 SYSCTL_INT(_debug, OID_AUTO, tickdelay, CTLFLAG_RW, &tickdelay, 0, "");
536 SYSCTL_INT(_debug, OID_AUTO, worklist_push, CTLFLAG_RW, &stat_worklist_push, 0,"");
537 SYSCTL_INT(_debug, OID_AUTO, blk_limit_push, CTLFLAG_RW, &stat_blk_limit_push, 0,"");
538 SYSCTL_INT(_debug, OID_AUTO, ino_limit_push, CTLFLAG_RW, &stat_ino_limit_push, 0,"");
539 SYSCTL_INT(_debug, OID_AUTO, blk_limit_hit, CTLFLAG_RW, &stat_blk_limit_hit, 0, "");
540 SYSCTL_INT(_debug, OID_AUTO, ino_limit_hit, CTLFLAG_RW, &stat_ino_limit_hit, 0, "");
541 SYSCTL_INT(_debug, OID_AUTO, sync_limit_hit, CTLFLAG_RW, &stat_sync_limit_hit, 0, "");
542 SYSCTL_INT(_debug, OID_AUTO, indir_blk_ptrs, CTLFLAG_RW, &stat_indir_blk_ptrs, 0, "");
543 SYSCTL_INT(_debug, OID_AUTO, inode_bitmap, CTLFLAG_RW, &stat_inode_bitmap, 0, "");
544 SYSCTL_INT(_debug, OID_AUTO, direct_blk_ptrs, CTLFLAG_RW, &stat_direct_blk_ptrs, 0, "");
545 SYSCTL_INT(_debug, OID_AUTO, dir_entry, CTLFLAG_RW, &stat_dir_entry, 0, "");
546 #endif /* DEBUG */
547 
548 /*
549  * Add an item to the end of the work queue.
550  * This routine requires that the lock be held.
551  * This is the only routine that adds items to the list.
552  * The following routine is the only one that removes items
553  * and does so in order from first to last.
554  */
555 static void
556 add_to_worklist(wk)
557 	struct worklist *wk;
558 {
559 	static struct worklist *worklist_tail;
560 
561 	if (wk->wk_state & ONWORKLIST) {
562 		if (lk.lkt_held != NOHOLDER)
563 			FREE_LOCK(&lk);
564 		panic("add_to_worklist: already on list");
565 	}
566 	wk->wk_state |= ONWORKLIST;
567 	if (LIST_FIRST(&softdep_workitem_pending) == NULL)
568 		LIST_INSERT_HEAD(&softdep_workitem_pending, wk, wk_list);
569 	else
570 		LIST_INSERT_AFTER(worklist_tail, wk, wk_list);
571 	worklist_tail = wk;
572 	num_on_worklist += 1;
573 }
574 
575 /*
576  * Process that runs once per second to handle items in the background queue.
577  *
578  * Note that we ensure that everything is done in the order in which they
579  * appear in the queue. The code below depends on this property to ensure
580  * that blocks of a file are freed before the inode itself is freed. This
581  * ordering ensures that no new <vfsid, inum, lbn> triples will be generated
582  * until all the old ones have been purged from the dependency lists.
583  */
584 static int
585 softdep_process_worklist(matchmnt)
586 	struct mount *matchmnt;
587 {
588 	thread_t td = curthread;
589 	int matchcnt, loopcount;
590 	long starttime;
591 
592 	/*
593 	 * Record the process identifier of our caller so that we can give
594 	 * this process preferential treatment in request_cleanup below.
595 	 */
596 	filesys_syncer = td;
597 	matchcnt = 0;
598 
599 	/*
600 	 * There is no danger of having multiple processes run this
601 	 * code, but we have to single-thread it when softdep_flushfiles()
602 	 * is in operation to get an accurate count of the number of items
603 	 * related to its mount point that are in the list.
604 	 */
605 	if (matchmnt == NULL) {
606 		if (softdep_worklist_busy < 0)
607 			return(-1);
608 		softdep_worklist_busy += 1;
609 	}
610 
611 	/*
612 	 * If requested, try removing inode or removal dependencies.
613 	 */
614 	if (req_clear_inodedeps) {
615 		clear_inodedeps(td);
616 		req_clear_inodedeps -= 1;
617 		wakeup_one(&proc_waiting);
618 	}
619 	if (req_clear_remove) {
620 		clear_remove(td);
621 		req_clear_remove -= 1;
622 		wakeup_one(&proc_waiting);
623 	}
624 	loopcount = 1;
625 	starttime = time_second;
626 	while (num_on_worklist > 0) {
627 		matchcnt += process_worklist_item(matchmnt, 0);
628 
629 		/*
630 		 * If a umount operation wants to run the worklist
631 		 * accurately, abort.
632 		 */
633 		if (softdep_worklist_req && matchmnt == NULL) {
634 			matchcnt = -1;
635 			break;
636 		}
637 
638 		/*
639 		 * If requested, try removing inode or removal dependencies.
640 		 */
641 		if (req_clear_inodedeps) {
642 			clear_inodedeps(td);
643 			req_clear_inodedeps -= 1;
644 			wakeup_one(&proc_waiting);
645 		}
646 		if (req_clear_remove) {
647 			clear_remove(td);
648 			req_clear_remove -= 1;
649 			wakeup_one(&proc_waiting);
650 		}
651 		/*
652 		 * We do not generally want to stop for buffer space, but if
653 		 * we are really being a buffer hog, we will stop and wait.
654 		 */
655 		if (loopcount++ % 128 == 0)
656 			bwillwrite();
657 		/*
658 		 * Never allow processing to run for more than one
659 		 * second. Otherwise the other syncer tasks may get
660 		 * excessively backlogged.
661 		 */
662 		if (starttime != time_second && matchmnt == NULL) {
663 			matchcnt = -1;
664 			break;
665 		}
666 	}
667 	if (matchmnt == NULL) {
668 		--softdep_worklist_busy;
669 		if (softdep_worklist_req && softdep_worklist_busy == 0)
670 			wakeup(&softdep_worklist_req);
671 	}
672 	return (matchcnt);
673 }
674 
675 /*
676  * Process one item on the worklist.
677  */
678 static int
679 process_worklist_item(matchmnt, flags)
680 	struct mount *matchmnt;
681 	int flags;
682 {
683 	struct worklist *wk;
684 	struct dirrem *dirrem;
685 	struct fs *matchfs;
686 	struct vnode *vp;
687 	int matchcnt = 0;
688 
689 	matchfs = NULL;
690 	if (matchmnt != NULL)
691 		matchfs = VFSTOUFS(matchmnt)->um_fs;
692 	ACQUIRE_LOCK(&lk);
693 	/*
694 	 * Normally we just process each item on the worklist in order.
695 	 * However, if we are in a situation where we cannot lock any
696 	 * inodes, we have to skip over any dirrem requests whose
697 	 * vnodes are resident and locked.
698 	 */
699 	LIST_FOREACH(wk, &softdep_workitem_pending, wk_list) {
700 		if ((flags & LK_NOWAIT) == 0 || wk->wk_type != D_DIRREM)
701 			break;
702 		dirrem = WK_DIRREM(wk);
703 		vp = ufs_ihashlookup(VFSTOUFS(dirrem->dm_mnt)->um_dev,
704 		    dirrem->dm_oldinum);
705 		if (vp == NULL || !VOP_ISLOCKED(vp, curthread))
706 			break;
707 	}
708 	if (wk == 0) {
709 		FREE_LOCK(&lk);
710 		return (0);
711 	}
712 	WORKLIST_REMOVE(wk);
713 	num_on_worklist -= 1;
714 	FREE_LOCK(&lk);
715 	switch (wk->wk_type) {
716 
717 	case D_DIRREM:
718 		/* removal of a directory entry */
719 		if (WK_DIRREM(wk)->dm_mnt == matchmnt)
720 			matchcnt += 1;
721 		handle_workitem_remove(WK_DIRREM(wk));
722 		break;
723 
724 	case D_FREEBLKS:
725 		/* releasing blocks and/or fragments from a file */
726 		if (WK_FREEBLKS(wk)->fb_fs == matchfs)
727 			matchcnt += 1;
728 		handle_workitem_freeblocks(WK_FREEBLKS(wk));
729 		break;
730 
731 	case D_FREEFRAG:
732 		/* releasing a fragment when replaced as a file grows */
733 		if (WK_FREEFRAG(wk)->ff_fs == matchfs)
734 			matchcnt += 1;
735 		handle_workitem_freefrag(WK_FREEFRAG(wk));
736 		break;
737 
738 	case D_FREEFILE:
739 		/* releasing an inode when its link count drops to 0 */
740 		if (WK_FREEFILE(wk)->fx_fs == matchfs)
741 			matchcnt += 1;
742 		handle_workitem_freefile(WK_FREEFILE(wk));
743 		break;
744 
745 	default:
746 		panic("%s_process_worklist: Unknown type %s",
747 		    "softdep", TYPENAME(wk->wk_type));
748 		/* NOTREACHED */
749 	}
750 	return (matchcnt);
751 }
752 
753 /*
754  * Move dependencies from one buffer to another.
755  */
756 static void
757 softdep_move_dependencies(oldbp, newbp)
758 	struct buf *oldbp;
759 	struct buf *newbp;
760 {
761 	struct worklist *wk, *wktail;
762 
763 	if (LIST_FIRST(&newbp->b_dep) != NULL)
764 		panic("softdep_move_dependencies: need merge code");
765 	wktail = 0;
766 	ACQUIRE_LOCK(&lk);
767 	while ((wk = LIST_FIRST(&oldbp->b_dep)) != NULL) {
768 		LIST_REMOVE(wk, wk_list);
769 		if (wktail == 0)
770 			LIST_INSERT_HEAD(&newbp->b_dep, wk, wk_list);
771 		else
772 			LIST_INSERT_AFTER(wktail, wk, wk_list);
773 		wktail = wk;
774 	}
775 	FREE_LOCK(&lk);
776 }
777 
778 /*
779  * Purge the work list of all items associated with a particular mount point.
780  */
781 int
782 softdep_flushfiles(struct mount *oldmnt, int flags, struct thread *td)
783 {
784 	struct vnode *devvp;
785 	int error, loopcnt;
786 
787 	/*
788 	 * Await our turn to clear out the queue, then serialize access.
789 	 */
790 	while (softdep_worklist_busy != 0) {
791 		softdep_worklist_req += 1;
792 		tsleep(&softdep_worklist_req, 0, "softflush", 0);
793 		softdep_worklist_req -= 1;
794 	}
795 	softdep_worklist_busy = -1;
796 
797 	if ((error = ffs_flushfiles(oldmnt, flags, td)) != 0) {
798 		softdep_worklist_busy = 0;
799 		if (softdep_worklist_req)
800 			wakeup(&softdep_worklist_req);
801 		return (error);
802 	}
803 	/*
804 	 * Alternately flush the block device associated with the mount
805 	 * point and process any dependencies that the flushing
806 	 * creates. In theory, this loop can happen at most twice,
807 	 * but we give it a few extra just to be sure.
808 	 */
809 	devvp = VFSTOUFS(oldmnt)->um_devvp;
810 	for (loopcnt = 10; loopcnt > 0; ) {
811 		if (softdep_process_worklist(oldmnt) == 0) {
812 			loopcnt--;
813 			/*
814 			 * Do another flush in case any vnodes were brought in
815 			 * as part of the cleanup operations.
816 			 */
817 			if ((error = ffs_flushfiles(oldmnt, flags, td)) != 0)
818 				break;
819 			/*
820 			 * If we still found nothing to do, we are really done.
821 			 */
822 			if (softdep_process_worklist(oldmnt) == 0)
823 				break;
824 		}
825 		vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY, td);
826 		error = VOP_FSYNC(devvp, MNT_WAIT, td);
827 		VOP_UNLOCK(devvp, 0, td);
828 		if (error)
829 			break;
830 	}
831 	softdep_worklist_busy = 0;
832 	if (softdep_worklist_req)
833 		wakeup(&softdep_worklist_req);
834 
835 	/*
836 	 * If we are unmounting then it is an error to fail. If we
837 	 * are simply trying to downgrade to read-only, then filesystem
838 	 * activity can keep us busy forever, so we just fail with EBUSY.
839 	 */
840 	if (loopcnt == 0) {
841 		if (oldmnt->mnt_kern_flag & MNTK_UNMOUNT)
842 			panic("softdep_flushfiles: looping");
843 		error = EBUSY;
844 	}
845 	return (error);
846 }
847 
848 /*
849  * Structure hashing.
850  *
851  * There are three types of structures that can be looked up:
852  *	1) pagedep structures identified by mount point, inode number,
853  *	   and logical block.
854  *	2) inodedep structures identified by mount point and inode number.
855  *	3) newblk structures identified by mount point and
856  *	   physical block number.
857  *
858  * The "pagedep" and "inodedep" dependency structures are hashed
859  * separately from the file blocks and inodes to which they correspond.
860  * This separation helps when the in-memory copy of an inode or
861  * file block must be replaced. It also obviates the need to access
862  * an inode or file page when simply updating (or de-allocating)
863  * dependency structures. Lookup of newblk structures is needed to
864  * find newly allocated blocks when trying to associate them with
865  * their allocdirect or allocindir structure.
866  *
867  * The lookup routines optionally create and hash a new instance when
868  * an existing entry is not found.
869  */
870 #define DEPALLOC	0x0001	/* allocate structure if lookup fails */
871 #define NODELAY		0x0002	/* cannot do background work */
872 
873 /*
874  * Structures and routines associated with pagedep caching.
875  */
876 LIST_HEAD(pagedep_hashhead, pagedep) *pagedep_hashtbl;
877 u_long	pagedep_hash;		/* size of hash table - 1 */
878 #define	PAGEDEP_HASH(mp, inum, lbn) \
879 	(&pagedep_hashtbl[((((register_t)(mp)) >> 13) + (inum) + (lbn)) & \
880 	    pagedep_hash])
881 static struct sema pagedep_in_progress;
882 
883 /*
884  * Look up a pagedep. Return 1 if found, 0 if not found.
885  * If not found, allocate if DEPALLOC flag is passed.
886  * Found or allocated entry is returned in pagedeppp.
887  * This routine must be called with splbio interrupts blocked.
888  */
889 static int
890 pagedep_lookup(ip, lbn, flags, pagedeppp)
891 	struct inode *ip;
892 	ufs_lbn_t lbn;
893 	int flags;
894 	struct pagedep **pagedeppp;
895 {
896 	struct pagedep *pagedep;
897 	struct pagedep_hashhead *pagedephd;
898 	struct mount *mp;
899 	int i;
900 
901 #ifdef DEBUG
902 	if (lk.lkt_held == NOHOLDER)
903 		panic("pagedep_lookup: lock not held");
904 #endif
905 	mp = ITOV(ip)->v_mount;
906 	pagedephd = PAGEDEP_HASH(mp, ip->i_number, lbn);
907 top:
908 	LIST_FOREACH(pagedep, pagedephd, pd_hash)
909 		if (ip->i_number == pagedep->pd_ino &&
910 		    lbn == pagedep->pd_lbn &&
911 		    mp == pagedep->pd_mnt)
912 			break;
913 	if (pagedep) {
914 		*pagedeppp = pagedep;
915 		return (1);
916 	}
917 	if ((flags & DEPALLOC) == 0) {
918 		*pagedeppp = NULL;
919 		return (0);
920 	}
921 	if (sema_get(&pagedep_in_progress, &lk) == 0) {
922 		ACQUIRE_LOCK(&lk);
923 		goto top;
924 	}
925 	MALLOC(pagedep, struct pagedep *, sizeof(struct pagedep), M_PAGEDEP,
926 		M_SOFTDEP_FLAGS);
927 	bzero(pagedep, sizeof(struct pagedep));
928 	pagedep->pd_list.wk_type = D_PAGEDEP;
929 	pagedep->pd_mnt = mp;
930 	pagedep->pd_ino = ip->i_number;
931 	pagedep->pd_lbn = lbn;
932 	LIST_INIT(&pagedep->pd_dirremhd);
933 	LIST_INIT(&pagedep->pd_pendinghd);
934 	for (i = 0; i < DAHASHSZ; i++)
935 		LIST_INIT(&pagedep->pd_diraddhd[i]);
936 	ACQUIRE_LOCK(&lk);
937 	LIST_INSERT_HEAD(pagedephd, pagedep, pd_hash);
938 	sema_release(&pagedep_in_progress);
939 	*pagedeppp = pagedep;
940 	return (0);
941 }
942 
943 /*
944  * Structures and routines associated with inodedep caching.
945  */
946 LIST_HEAD(inodedep_hashhead, inodedep) *inodedep_hashtbl;
947 static u_long	inodedep_hash;	/* size of hash table - 1 */
948 static long	num_inodedep;	/* number of inodedep allocated */
949 #define	INODEDEP_HASH(fs, inum) \
950       (&inodedep_hashtbl[((((register_t)(fs)) >> 13) + (inum)) & inodedep_hash])
951 static struct sema inodedep_in_progress;
952 
953 /*
954  * Look up a inodedep. Return 1 if found, 0 if not found.
955  * If not found, allocate if DEPALLOC flag is passed.
956  * Found or allocated entry is returned in inodedeppp.
957  * This routine must be called with splbio interrupts blocked.
958  */
959 static int
960 inodedep_lookup(fs, inum, flags, inodedeppp)
961 	struct fs *fs;
962 	ino_t inum;
963 	int flags;
964 	struct inodedep **inodedeppp;
965 {
966 	struct inodedep *inodedep;
967 	struct inodedep_hashhead *inodedephd;
968 	int firsttry;
969 
970 #ifdef DEBUG
971 	if (lk.lkt_held == NOHOLDER)
972 		panic("inodedep_lookup: lock not held");
973 #endif
974 	firsttry = 1;
975 	inodedephd = INODEDEP_HASH(fs, inum);
976 top:
977 	LIST_FOREACH(inodedep, inodedephd, id_hash)
978 		if (inum == inodedep->id_ino && fs == inodedep->id_fs)
979 			break;
980 	if (inodedep) {
981 		*inodedeppp = inodedep;
982 		return (1);
983 	}
984 	if ((flags & DEPALLOC) == 0) {
985 		*inodedeppp = NULL;
986 		return (0);
987 	}
988 	/*
989 	 * If we are over our limit, try to improve the situation.
990 	 */
991 	if (num_inodedep > max_softdeps && firsttry &&
992 	    speedup_syncer() == 0 && (flags & NODELAY) == 0 &&
993 	    request_cleanup(FLUSH_INODES, 1)) {
994 		firsttry = 0;
995 		goto top;
996 	}
997 	if (sema_get(&inodedep_in_progress, &lk) == 0) {
998 		ACQUIRE_LOCK(&lk);
999 		goto top;
1000 	}
1001 	num_inodedep += 1;
1002 	MALLOC(inodedep, struct inodedep *, sizeof(struct inodedep),
1003 		M_INODEDEP, M_SOFTDEP_FLAGS);
1004 	inodedep->id_list.wk_type = D_INODEDEP;
1005 	inodedep->id_fs = fs;
1006 	inodedep->id_ino = inum;
1007 	inodedep->id_state = ALLCOMPLETE;
1008 	inodedep->id_nlinkdelta = 0;
1009 	inodedep->id_savedino = NULL;
1010 	inodedep->id_savedsize = -1;
1011 	inodedep->id_buf = NULL;
1012 	LIST_INIT(&inodedep->id_pendinghd);
1013 	LIST_INIT(&inodedep->id_inowait);
1014 	LIST_INIT(&inodedep->id_bufwait);
1015 	TAILQ_INIT(&inodedep->id_inoupdt);
1016 	TAILQ_INIT(&inodedep->id_newinoupdt);
1017 	ACQUIRE_LOCK(&lk);
1018 	LIST_INSERT_HEAD(inodedephd, inodedep, id_hash);
1019 	sema_release(&inodedep_in_progress);
1020 	*inodedeppp = inodedep;
1021 	return (0);
1022 }
1023 
1024 /*
1025  * Structures and routines associated with newblk caching.
1026  */
1027 LIST_HEAD(newblk_hashhead, newblk) *newblk_hashtbl;
1028 u_long	newblk_hash;		/* size of hash table - 1 */
1029 #define	NEWBLK_HASH(fs, inum) \
1030 	(&newblk_hashtbl[((((register_t)(fs)) >> 13) + (inum)) & newblk_hash])
1031 static struct sema newblk_in_progress;
1032 
1033 /*
1034  * Look up a newblk. Return 1 if found, 0 if not found.
1035  * If not found, allocate if DEPALLOC flag is passed.
1036  * Found or allocated entry is returned in newblkpp.
1037  */
1038 static int
1039 newblk_lookup(fs, newblkno, flags, newblkpp)
1040 	struct fs *fs;
1041 	ufs_daddr_t newblkno;
1042 	int flags;
1043 	struct newblk **newblkpp;
1044 {
1045 	struct newblk *newblk;
1046 	struct newblk_hashhead *newblkhd;
1047 
1048 	newblkhd = NEWBLK_HASH(fs, newblkno);
1049 top:
1050 	LIST_FOREACH(newblk, newblkhd, nb_hash)
1051 		if (newblkno == newblk->nb_newblkno && fs == newblk->nb_fs)
1052 			break;
1053 	if (newblk) {
1054 		*newblkpp = newblk;
1055 		return (1);
1056 	}
1057 	if ((flags & DEPALLOC) == 0) {
1058 		*newblkpp = NULL;
1059 		return (0);
1060 	}
1061 	if (sema_get(&newblk_in_progress, 0) == 0)
1062 		goto top;
1063 	MALLOC(newblk, struct newblk *, sizeof(struct newblk),
1064 		M_NEWBLK, M_SOFTDEP_FLAGS);
1065 	newblk->nb_state = 0;
1066 	newblk->nb_fs = fs;
1067 	newblk->nb_newblkno = newblkno;
1068 	LIST_INSERT_HEAD(newblkhd, newblk, nb_hash);
1069 	sema_release(&newblk_in_progress);
1070 	*newblkpp = newblk;
1071 	return (0);
1072 }
1073 
1074 /*
1075  * Executed during filesystem system initialization before
1076  * mounting any filesystems.
1077  */
1078 void
1079 softdep_initialize()
1080 {
1081 	callout_init(&handle);
1082 	bioops = softdep_bioops;	/* XXX hack */
1083 
1084 	LIST_INIT(&mkdirlisthd);
1085 	LIST_INIT(&softdep_workitem_pending);
1086 	max_softdeps = min(desiredvnodes * 8,
1087 		M_INODEDEP->ks_limit / (2 * sizeof(struct inodedep)));
1088 	pagedep_hashtbl = hashinit(desiredvnodes / 5, M_PAGEDEP,
1089 	    &pagedep_hash);
1090 	sema_init(&pagedep_in_progress, "pagedep", 0, 0);
1091 	inodedep_hashtbl = hashinit(desiredvnodes, M_INODEDEP, &inodedep_hash);
1092 	sema_init(&inodedep_in_progress, "inodedep", 0, 0);
1093 	newblk_hashtbl = hashinit(64, M_NEWBLK, &newblk_hash);
1094 	sema_init(&newblk_in_progress, "newblk", 0, 0);
1095 }
1096 
1097 /*
1098  * Called at mount time to notify the dependency code that a
1099  * filesystem wishes to use it.
1100  */
1101 int
1102 softdep_mount(devvp, mp, fs)
1103 	struct vnode *devvp;
1104 	struct mount *mp;
1105 	struct fs *fs;
1106 {
1107 	struct csum cstotal;
1108 	struct cg *cgp;
1109 	struct buf *bp;
1110 	int error, cyl;
1111 
1112 	mp->mnt_flag &= ~MNT_ASYNC;
1113 	mp->mnt_flag |= MNT_SOFTDEP;
1114 	/*
1115 	 * When doing soft updates, the counters in the
1116 	 * superblock may have gotten out of sync, so we have
1117 	 * to scan the cylinder groups and recalculate them.
1118 	 */
1119 	if (fs->fs_clean != 0)
1120 		return (0);
1121 	bzero(&cstotal, sizeof cstotal);
1122 	for (cyl = 0; cyl < fs->fs_ncg; cyl++) {
1123 		if ((error = bread(devvp, fsbtodb(fs, cgtod(fs, cyl)),
1124 		    fs->fs_cgsize, &bp)) != 0) {
1125 			brelse(bp);
1126 			return (error);
1127 		}
1128 		cgp = (struct cg *)bp->b_data;
1129 		cstotal.cs_nffree += cgp->cg_cs.cs_nffree;
1130 		cstotal.cs_nbfree += cgp->cg_cs.cs_nbfree;
1131 		cstotal.cs_nifree += cgp->cg_cs.cs_nifree;
1132 		cstotal.cs_ndir += cgp->cg_cs.cs_ndir;
1133 		fs->fs_cs(fs, cyl) = cgp->cg_cs;
1134 		brelse(bp);
1135 	}
1136 #ifdef DEBUG
1137 	if (bcmp(&cstotal, &fs->fs_cstotal, sizeof cstotal))
1138 		printf("ffs_mountfs: superblock updated for soft updates\n");
1139 #endif
1140 	bcopy(&cstotal, &fs->fs_cstotal, sizeof cstotal);
1141 	return (0);
1142 }
1143 
1144 /*
1145  * Protecting the freemaps (or bitmaps).
1146  *
1147  * To eliminate the need to execute fsck before mounting a filesystem
1148  * after a power failure, one must (conservatively) guarantee that the
1149  * on-disk copy of the bitmaps never indicate that a live inode or block is
1150  * free.  So, when a block or inode is allocated, the bitmap should be
1151  * updated (on disk) before any new pointers.  When a block or inode is
1152  * freed, the bitmap should not be updated until all pointers have been
1153  * reset.  The latter dependency is handled by the delayed de-allocation
1154  * approach described below for block and inode de-allocation.  The former
1155  * dependency is handled by calling the following procedure when a block or
1156  * inode is allocated. When an inode is allocated an "inodedep" is created
1157  * with its DEPCOMPLETE flag cleared until its bitmap is written to disk.
1158  * Each "inodedep" is also inserted into the hash indexing structure so
1159  * that any additional link additions can be made dependent on the inode
1160  * allocation.
1161  *
1162  * The ufs filesystem maintains a number of free block counts (e.g., per
1163  * cylinder group, per cylinder and per <cylinder, rotational position> pair)
1164  * in addition to the bitmaps.  These counts are used to improve efficiency
1165  * during allocation and therefore must be consistent with the bitmaps.
1166  * There is no convenient way to guarantee post-crash consistency of these
1167  * counts with simple update ordering, for two main reasons: (1) The counts
1168  * and bitmaps for a single cylinder group block are not in the same disk
1169  * sector.  If a disk write is interrupted (e.g., by power failure), one may
1170  * be written and the other not.  (2) Some of the counts are located in the
1171  * superblock rather than the cylinder group block. So, we focus our soft
1172  * updates implementation on protecting the bitmaps. When mounting a
1173  * filesystem, we recompute the auxiliary counts from the bitmaps.
1174  */
1175 
1176 /*
1177  * Called just after updating the cylinder group block to allocate an inode.
1178  */
1179 void
1180 softdep_setup_inomapdep(bp, ip, newinum)
1181 	struct buf *bp;		/* buffer for cylgroup block with inode map */
1182 	struct inode *ip;	/* inode related to allocation */
1183 	ino_t newinum;		/* new inode number being allocated */
1184 {
1185 	struct inodedep *inodedep;
1186 	struct bmsafemap *bmsafemap;
1187 
1188 	/*
1189 	 * Create a dependency for the newly allocated inode.
1190 	 * Panic if it already exists as something is seriously wrong.
1191 	 * Otherwise add it to the dependency list for the buffer holding
1192 	 * the cylinder group map from which it was allocated.
1193 	 */
1194 	ACQUIRE_LOCK(&lk);
1195 	if ((inodedep_lookup(ip->i_fs, newinum, DEPALLOC|NODELAY, &inodedep))) {
1196 		FREE_LOCK(&lk);
1197 		panic("softdep_setup_inomapdep: found inode");
1198 	}
1199 	inodedep->id_buf = bp;
1200 	inodedep->id_state &= ~DEPCOMPLETE;
1201 	bmsafemap = bmsafemap_lookup(bp);
1202 	LIST_INSERT_HEAD(&bmsafemap->sm_inodedephd, inodedep, id_deps);
1203 	FREE_LOCK(&lk);
1204 }
1205 
1206 /*
1207  * Called just after updating the cylinder group block to
1208  * allocate block or fragment.
1209  */
1210 void
1211 softdep_setup_blkmapdep(bp, fs, newblkno)
1212 	struct buf *bp;		/* buffer for cylgroup block with block map */
1213 	struct fs *fs;		/* filesystem doing allocation */
1214 	ufs_daddr_t newblkno;	/* number of newly allocated block */
1215 {
1216 	struct newblk *newblk;
1217 	struct bmsafemap *bmsafemap;
1218 
1219 	/*
1220 	 * Create a dependency for the newly allocated block.
1221 	 * Add it to the dependency list for the buffer holding
1222 	 * the cylinder group map from which it was allocated.
1223 	 */
1224 	if (newblk_lookup(fs, newblkno, DEPALLOC, &newblk) != 0)
1225 		panic("softdep_setup_blkmapdep: found block");
1226 	ACQUIRE_LOCK(&lk);
1227 	newblk->nb_bmsafemap = bmsafemap = bmsafemap_lookup(bp);
1228 	LIST_INSERT_HEAD(&bmsafemap->sm_newblkhd, newblk, nb_deps);
1229 	FREE_LOCK(&lk);
1230 }
1231 
1232 /*
1233  * Find the bmsafemap associated with a cylinder group buffer.
1234  * If none exists, create one. The buffer must be locked when
1235  * this routine is called and this routine must be called with
1236  * splbio interrupts blocked.
1237  */
1238 static struct bmsafemap *
1239 bmsafemap_lookup(bp)
1240 	struct buf *bp;
1241 {
1242 	struct bmsafemap *bmsafemap;
1243 	struct worklist *wk;
1244 
1245 #ifdef DEBUG
1246 	if (lk.lkt_held == NOHOLDER)
1247 		panic("bmsafemap_lookup: lock not held");
1248 #endif
1249 	LIST_FOREACH(wk, &bp->b_dep, wk_list)
1250 		if (wk->wk_type == D_BMSAFEMAP)
1251 			return (WK_BMSAFEMAP(wk));
1252 	FREE_LOCK(&lk);
1253 	MALLOC(bmsafemap, struct bmsafemap *, sizeof(struct bmsafemap),
1254 		M_BMSAFEMAP, M_SOFTDEP_FLAGS);
1255 	bmsafemap->sm_list.wk_type = D_BMSAFEMAP;
1256 	bmsafemap->sm_list.wk_state = 0;
1257 	bmsafemap->sm_buf = bp;
1258 	LIST_INIT(&bmsafemap->sm_allocdirecthd);
1259 	LIST_INIT(&bmsafemap->sm_allocindirhd);
1260 	LIST_INIT(&bmsafemap->sm_inodedephd);
1261 	LIST_INIT(&bmsafemap->sm_newblkhd);
1262 	ACQUIRE_LOCK(&lk);
1263 	WORKLIST_INSERT(&bp->b_dep, &bmsafemap->sm_list);
1264 	return (bmsafemap);
1265 }
1266 
1267 /*
1268  * Direct block allocation dependencies.
1269  *
1270  * When a new block is allocated, the corresponding disk locations must be
1271  * initialized (with zeros or new data) before the on-disk inode points to
1272  * them.  Also, the freemap from which the block was allocated must be
1273  * updated (on disk) before the inode's pointer. These two dependencies are
1274  * independent of each other and are needed for all file blocks and indirect
1275  * blocks that are pointed to directly by the inode.  Just before the
1276  * "in-core" version of the inode is updated with a newly allocated block
1277  * number, a procedure (below) is called to setup allocation dependency
1278  * structures.  These structures are removed when the corresponding
1279  * dependencies are satisfied or when the block allocation becomes obsolete
1280  * (i.e., the file is deleted, the block is de-allocated, or the block is a
1281  * fragment that gets upgraded).  All of these cases are handled in
1282  * procedures described later.
1283  *
1284  * When a file extension causes a fragment to be upgraded, either to a larger
1285  * fragment or to a full block, the on-disk location may change (if the
1286  * previous fragment could not simply be extended). In this case, the old
1287  * fragment must be de-allocated, but not until after the inode's pointer has
1288  * been updated. In most cases, this is handled by later procedures, which
1289  * will construct a "freefrag" structure to be added to the workitem queue
1290  * when the inode update is complete (or obsolete).  The main exception to
1291  * this is when an allocation occurs while a pending allocation dependency
1292  * (for the same block pointer) remains.  This case is handled in the main
1293  * allocation dependency setup procedure by immediately freeing the
1294  * unreferenced fragments.
1295  */
1296 void
1297 softdep_setup_allocdirect(ip, lbn, newblkno, oldblkno, newsize, oldsize, bp)
1298 	struct inode *ip;	/* inode to which block is being added */
1299 	ufs_lbn_t lbn;		/* block pointer within inode */
1300 	ufs_daddr_t newblkno;	/* disk block number being added */
1301 	ufs_daddr_t oldblkno;	/* previous block number, 0 unless frag */
1302 	long newsize;		/* size of new block */
1303 	long oldsize;		/* size of new block */
1304 	struct buf *bp;		/* bp for allocated block */
1305 {
1306 	struct allocdirect *adp, *oldadp;
1307 	struct allocdirectlst *adphead;
1308 	struct bmsafemap *bmsafemap;
1309 	struct inodedep *inodedep;
1310 	struct pagedep *pagedep;
1311 	struct newblk *newblk;
1312 
1313 	MALLOC(adp, struct allocdirect *, sizeof(struct allocdirect),
1314 		M_ALLOCDIRECT, M_SOFTDEP_FLAGS);
1315 	bzero(adp, sizeof(struct allocdirect));
1316 	adp->ad_list.wk_type = D_ALLOCDIRECT;
1317 	adp->ad_lbn = lbn;
1318 	adp->ad_newblkno = newblkno;
1319 	adp->ad_oldblkno = oldblkno;
1320 	adp->ad_newsize = newsize;
1321 	adp->ad_oldsize = oldsize;
1322 	adp->ad_state = ATTACHED;
1323 	if (newblkno == oldblkno)
1324 		adp->ad_freefrag = NULL;
1325 	else
1326 		adp->ad_freefrag = newfreefrag(ip, oldblkno, oldsize);
1327 
1328 	if (newblk_lookup(ip->i_fs, newblkno, 0, &newblk) == 0)
1329 		panic("softdep_setup_allocdirect: lost block");
1330 
1331 	ACQUIRE_LOCK(&lk);
1332 	inodedep_lookup(ip->i_fs, ip->i_number, DEPALLOC | NODELAY, &inodedep);
1333 	adp->ad_inodedep = inodedep;
1334 
1335 	if (newblk->nb_state == DEPCOMPLETE) {
1336 		adp->ad_state |= DEPCOMPLETE;
1337 		adp->ad_buf = NULL;
1338 	} else {
1339 		bmsafemap = newblk->nb_bmsafemap;
1340 		adp->ad_buf = bmsafemap->sm_buf;
1341 		LIST_REMOVE(newblk, nb_deps);
1342 		LIST_INSERT_HEAD(&bmsafemap->sm_allocdirecthd, adp, ad_deps);
1343 	}
1344 	LIST_REMOVE(newblk, nb_hash);
1345 	FREE(newblk, M_NEWBLK);
1346 
1347 	WORKLIST_INSERT(&bp->b_dep, &adp->ad_list);
1348 	if (lbn >= NDADDR) {
1349 		/* allocating an indirect block */
1350 		if (oldblkno != 0) {
1351 			FREE_LOCK(&lk);
1352 			panic("softdep_setup_allocdirect: non-zero indir");
1353 		}
1354 	} else {
1355 		/*
1356 		 * Allocating a direct block.
1357 		 *
1358 		 * If we are allocating a directory block, then we must
1359 		 * allocate an associated pagedep to track additions and
1360 		 * deletions.
1361 		 */
1362 		if ((ip->i_mode & IFMT) == IFDIR &&
1363 		    pagedep_lookup(ip, lbn, DEPALLOC, &pagedep) == 0)
1364 			WORKLIST_INSERT(&bp->b_dep, &pagedep->pd_list);
1365 	}
1366 	/*
1367 	 * The list of allocdirects must be kept in sorted and ascending
1368 	 * order so that the rollback routines can quickly determine the
1369 	 * first uncommitted block (the size of the file stored on disk
1370 	 * ends at the end of the lowest committed fragment, or if there
1371 	 * are no fragments, at the end of the highest committed block).
1372 	 * Since files generally grow, the typical case is that the new
1373 	 * block is to be added at the end of the list. We speed this
1374 	 * special case by checking against the last allocdirect in the
1375 	 * list before laboriously traversing the list looking for the
1376 	 * insertion point.
1377 	 */
1378 	adphead = &inodedep->id_newinoupdt;
1379 	oldadp = TAILQ_LAST(adphead, allocdirectlst);
1380 	if (oldadp == NULL || oldadp->ad_lbn <= lbn) {
1381 		/* insert at end of list */
1382 		TAILQ_INSERT_TAIL(adphead, adp, ad_next);
1383 		if (oldadp != NULL && oldadp->ad_lbn == lbn)
1384 			allocdirect_merge(adphead, adp, oldadp);
1385 		FREE_LOCK(&lk);
1386 		return;
1387 	}
1388 	TAILQ_FOREACH(oldadp, adphead, ad_next) {
1389 		if (oldadp->ad_lbn >= lbn)
1390 			break;
1391 	}
1392 	if (oldadp == NULL) {
1393 		FREE_LOCK(&lk);
1394 		panic("softdep_setup_allocdirect: lost entry");
1395 	}
1396 	/* insert in middle of list */
1397 	TAILQ_INSERT_BEFORE(oldadp, adp, ad_next);
1398 	if (oldadp->ad_lbn == lbn)
1399 		allocdirect_merge(adphead, adp, oldadp);
1400 	FREE_LOCK(&lk);
1401 }
1402 
1403 /*
1404  * Replace an old allocdirect dependency with a newer one.
1405  * This routine must be called with splbio interrupts blocked.
1406  */
1407 static void
1408 allocdirect_merge(adphead, newadp, oldadp)
1409 	struct allocdirectlst *adphead;	/* head of list holding allocdirects */
1410 	struct allocdirect *newadp;	/* allocdirect being added */
1411 	struct allocdirect *oldadp;	/* existing allocdirect being checked */
1412 {
1413 	struct freefrag *freefrag;
1414 
1415 #ifdef DEBUG
1416 	if (lk.lkt_held == NOHOLDER)
1417 		panic("allocdirect_merge: lock not held");
1418 #endif
1419 	if (newadp->ad_oldblkno != oldadp->ad_newblkno ||
1420 	    newadp->ad_oldsize != oldadp->ad_newsize ||
1421 	    newadp->ad_lbn >= NDADDR) {
1422 		FREE_LOCK(&lk);
1423 		panic("allocdirect_check: old %d != new %d || lbn %ld >= %d",
1424 		    newadp->ad_oldblkno, oldadp->ad_newblkno, newadp->ad_lbn,
1425 		    NDADDR);
1426 	}
1427 	newadp->ad_oldblkno = oldadp->ad_oldblkno;
1428 	newadp->ad_oldsize = oldadp->ad_oldsize;
1429 	/*
1430 	 * If the old dependency had a fragment to free or had never
1431 	 * previously had a block allocated, then the new dependency
1432 	 * can immediately post its freefrag and adopt the old freefrag.
1433 	 * This action is done by swapping the freefrag dependencies.
1434 	 * The new dependency gains the old one's freefrag, and the
1435 	 * old one gets the new one and then immediately puts it on
1436 	 * the worklist when it is freed by free_allocdirect. It is
1437 	 * not possible to do this swap when the old dependency had a
1438 	 * non-zero size but no previous fragment to free. This condition
1439 	 * arises when the new block is an extension of the old block.
1440 	 * Here, the first part of the fragment allocated to the new
1441 	 * dependency is part of the block currently claimed on disk by
1442 	 * the old dependency, so cannot legitimately be freed until the
1443 	 * conditions for the new dependency are fulfilled.
1444 	 */
1445 	if (oldadp->ad_freefrag != NULL || oldadp->ad_oldblkno == 0) {
1446 		freefrag = newadp->ad_freefrag;
1447 		newadp->ad_freefrag = oldadp->ad_freefrag;
1448 		oldadp->ad_freefrag = freefrag;
1449 	}
1450 	free_allocdirect(adphead, oldadp, 0);
1451 }
1452 
1453 /*
1454  * Allocate a new freefrag structure if needed.
1455  */
1456 static struct freefrag *
1457 newfreefrag(ip, blkno, size)
1458 	struct inode *ip;
1459 	ufs_daddr_t blkno;
1460 	long size;
1461 {
1462 	struct freefrag *freefrag;
1463 	struct fs *fs;
1464 
1465 	if (blkno == 0)
1466 		return (NULL);
1467 	fs = ip->i_fs;
1468 	if (fragnum(fs, blkno) + numfrags(fs, size) > fs->fs_frag)
1469 		panic("newfreefrag: frag size");
1470 	MALLOC(freefrag, struct freefrag *, sizeof(struct freefrag),
1471 		M_FREEFRAG, M_SOFTDEP_FLAGS);
1472 	freefrag->ff_list.wk_type = D_FREEFRAG;
1473 	freefrag->ff_state = ip->i_uid & ~ONWORKLIST;	/* XXX - used below */
1474 	freefrag->ff_inum = ip->i_number;
1475 	freefrag->ff_fs = fs;
1476 	freefrag->ff_devvp = ip->i_devvp;
1477 	freefrag->ff_blkno = blkno;
1478 	freefrag->ff_fragsize = size;
1479 	return (freefrag);
1480 }
1481 
1482 /*
1483  * This workitem de-allocates fragments that were replaced during
1484  * file block allocation.
1485  */
1486 static void
1487 handle_workitem_freefrag(freefrag)
1488 	struct freefrag *freefrag;
1489 {
1490 	struct inode tip;
1491 
1492 	tip.i_fs = freefrag->ff_fs;
1493 	tip.i_devvp = freefrag->ff_devvp;
1494 	tip.i_dev = freefrag->ff_devvp->v_rdev;
1495 	tip.i_number = freefrag->ff_inum;
1496 	tip.i_uid = freefrag->ff_state & ~ONWORKLIST;	/* XXX - set above */
1497 	ffs_blkfree(&tip, freefrag->ff_blkno, freefrag->ff_fragsize);
1498 	FREE(freefrag, M_FREEFRAG);
1499 }
1500 
1501 /*
1502  * Indirect block allocation dependencies.
1503  *
1504  * The same dependencies that exist for a direct block also exist when
1505  * a new block is allocated and pointed to by an entry in a block of
1506  * indirect pointers. The undo/redo states described above are also
1507  * used here. Because an indirect block contains many pointers that
1508  * may have dependencies, a second copy of the entire in-memory indirect
1509  * block is kept. The buffer cache copy is always completely up-to-date.
1510  * The second copy, which is used only as a source for disk writes,
1511  * contains only the safe pointers (i.e., those that have no remaining
1512  * update dependencies). The second copy is freed when all pointers
1513  * are safe. The cache is not allowed to replace indirect blocks with
1514  * pending update dependencies. If a buffer containing an indirect
1515  * block with dependencies is written, these routines will mark it
1516  * dirty again. It can only be successfully written once all the
1517  * dependencies are removed. The ffs_fsync routine in conjunction with
1518  * softdep_sync_metadata work together to get all the dependencies
1519  * removed so that a file can be successfully written to disk. Three
1520  * procedures are used when setting up indirect block pointer
1521  * dependencies. The division is necessary because of the organization
1522  * of the "balloc" routine and because of the distinction between file
1523  * pages and file metadata blocks.
1524  */
1525 
1526 /*
1527  * Allocate a new allocindir structure.
1528  */
1529 static struct allocindir *
1530 newallocindir(ip, ptrno, newblkno, oldblkno)
1531 	struct inode *ip;	/* inode for file being extended */
1532 	int ptrno;		/* offset of pointer in indirect block */
1533 	ufs_daddr_t newblkno;	/* disk block number being added */
1534 	ufs_daddr_t oldblkno;	/* previous block number, 0 if none */
1535 {
1536 	struct allocindir *aip;
1537 
1538 	MALLOC(aip, struct allocindir *, sizeof(struct allocindir),
1539 		M_ALLOCINDIR, M_SOFTDEP_FLAGS);
1540 	bzero(aip, sizeof(struct allocindir));
1541 	aip->ai_list.wk_type = D_ALLOCINDIR;
1542 	aip->ai_state = ATTACHED;
1543 	aip->ai_offset = ptrno;
1544 	aip->ai_newblkno = newblkno;
1545 	aip->ai_oldblkno = oldblkno;
1546 	aip->ai_freefrag = newfreefrag(ip, oldblkno, ip->i_fs->fs_bsize);
1547 	return (aip);
1548 }
1549 
1550 /*
1551  * Called just before setting an indirect block pointer
1552  * to a newly allocated file page.
1553  */
1554 void
1555 softdep_setup_allocindir_page(ip, lbn, bp, ptrno, newblkno, oldblkno, nbp)
1556 	struct inode *ip;	/* inode for file being extended */
1557 	ufs_lbn_t lbn;		/* allocated block number within file */
1558 	struct buf *bp;		/* buffer with indirect blk referencing page */
1559 	int ptrno;		/* offset of pointer in indirect block */
1560 	ufs_daddr_t newblkno;	/* disk block number being added */
1561 	ufs_daddr_t oldblkno;	/* previous block number, 0 if none */
1562 	struct buf *nbp;	/* buffer holding allocated page */
1563 {
1564 	struct allocindir *aip;
1565 	struct pagedep *pagedep;
1566 
1567 	aip = newallocindir(ip, ptrno, newblkno, oldblkno);
1568 	ACQUIRE_LOCK(&lk);
1569 	/*
1570 	 * If we are allocating a directory page, then we must
1571 	 * allocate an associated pagedep to track additions and
1572 	 * deletions.
1573 	 */
1574 	if ((ip->i_mode & IFMT) == IFDIR &&
1575 	    pagedep_lookup(ip, lbn, DEPALLOC, &pagedep) == 0)
1576 		WORKLIST_INSERT(&nbp->b_dep, &pagedep->pd_list);
1577 	WORKLIST_INSERT(&nbp->b_dep, &aip->ai_list);
1578 	FREE_LOCK(&lk);
1579 	setup_allocindir_phase2(bp, ip, aip);
1580 }
1581 
1582 /*
1583  * Called just before setting an indirect block pointer to a
1584  * newly allocated indirect block.
1585  */
1586 void
1587 softdep_setup_allocindir_meta(nbp, ip, bp, ptrno, newblkno)
1588 	struct buf *nbp;	/* newly allocated indirect block */
1589 	struct inode *ip;	/* inode for file being extended */
1590 	struct buf *bp;		/* indirect block referencing allocated block */
1591 	int ptrno;		/* offset of pointer in indirect block */
1592 	ufs_daddr_t newblkno;	/* disk block number being added */
1593 {
1594 	struct allocindir *aip;
1595 
1596 	aip = newallocindir(ip, ptrno, newblkno, 0);
1597 	ACQUIRE_LOCK(&lk);
1598 	WORKLIST_INSERT(&nbp->b_dep, &aip->ai_list);
1599 	FREE_LOCK(&lk);
1600 	setup_allocindir_phase2(bp, ip, aip);
1601 }
1602 
1603 /*
1604  * Called to finish the allocation of the "aip" allocated
1605  * by one of the two routines above.
1606  */
1607 static void
1608 setup_allocindir_phase2(bp, ip, aip)
1609 	struct buf *bp;		/* in-memory copy of the indirect block */
1610 	struct inode *ip;	/* inode for file being extended */
1611 	struct allocindir *aip;	/* allocindir allocated by the above routines */
1612 {
1613 	struct worklist *wk;
1614 	struct indirdep *indirdep, *newindirdep;
1615 	struct bmsafemap *bmsafemap;
1616 	struct allocindir *oldaip;
1617 	struct freefrag *freefrag;
1618 	struct newblk *newblk;
1619 
1620 	if (bp->b_lblkno >= 0)
1621 		panic("setup_allocindir_phase2: not indir blk");
1622 	for (indirdep = NULL, newindirdep = NULL; ; ) {
1623 		ACQUIRE_LOCK(&lk);
1624 		LIST_FOREACH(wk, &bp->b_dep, wk_list) {
1625 			if (wk->wk_type != D_INDIRDEP)
1626 				continue;
1627 			indirdep = WK_INDIRDEP(wk);
1628 			break;
1629 		}
1630 		if (indirdep == NULL && newindirdep) {
1631 			indirdep = newindirdep;
1632 			WORKLIST_INSERT(&bp->b_dep, &indirdep->ir_list);
1633 			newindirdep = NULL;
1634 		}
1635 		FREE_LOCK(&lk);
1636 		if (indirdep) {
1637 			if (newblk_lookup(ip->i_fs, aip->ai_newblkno, 0,
1638 			    &newblk) == 0)
1639 				panic("setup_allocindir: lost block");
1640 			ACQUIRE_LOCK(&lk);
1641 			if (newblk->nb_state == DEPCOMPLETE) {
1642 				aip->ai_state |= DEPCOMPLETE;
1643 				aip->ai_buf = NULL;
1644 			} else {
1645 				bmsafemap = newblk->nb_bmsafemap;
1646 				aip->ai_buf = bmsafemap->sm_buf;
1647 				LIST_REMOVE(newblk, nb_deps);
1648 				LIST_INSERT_HEAD(&bmsafemap->sm_allocindirhd,
1649 				    aip, ai_deps);
1650 			}
1651 			LIST_REMOVE(newblk, nb_hash);
1652 			FREE(newblk, M_NEWBLK);
1653 			aip->ai_indirdep = indirdep;
1654 			/*
1655 			 * Check to see if there is an existing dependency
1656 			 * for this block. If there is, merge the old
1657 			 * dependency into the new one.
1658 			 */
1659 			if (aip->ai_oldblkno == 0)
1660 				oldaip = NULL;
1661 			else
1662 
1663 				LIST_FOREACH(oldaip, &indirdep->ir_deplisthd, ai_next)
1664 					if (oldaip->ai_offset == aip->ai_offset)
1665 						break;
1666 			if (oldaip != NULL) {
1667 				if (oldaip->ai_newblkno != aip->ai_oldblkno) {
1668 					FREE_LOCK(&lk);
1669 					panic("setup_allocindir_phase2: blkno");
1670 				}
1671 				aip->ai_oldblkno = oldaip->ai_oldblkno;
1672 				freefrag = oldaip->ai_freefrag;
1673 				oldaip->ai_freefrag = aip->ai_freefrag;
1674 				aip->ai_freefrag = freefrag;
1675 				free_allocindir(oldaip, NULL);
1676 			}
1677 			LIST_INSERT_HEAD(&indirdep->ir_deplisthd, aip, ai_next);
1678 			((ufs_daddr_t *)indirdep->ir_savebp->b_data)
1679 			    [aip->ai_offset] = aip->ai_oldblkno;
1680 			FREE_LOCK(&lk);
1681 		}
1682 		if (newindirdep) {
1683 			/*
1684 			 * Avoid any possibility of data corruption by
1685 			 * ensuring that our old version is thrown away.
1686 			 */
1687 			newindirdep->ir_savebp->b_flags |= B_INVAL | B_NOCACHE;
1688 			brelse(newindirdep->ir_savebp);
1689 			WORKITEM_FREE((caddr_t)newindirdep, D_INDIRDEP);
1690 		}
1691 		if (indirdep)
1692 			break;
1693 		MALLOC(newindirdep, struct indirdep *, sizeof(struct indirdep),
1694 			M_INDIRDEP, M_SOFTDEP_FLAGS);
1695 		newindirdep->ir_list.wk_type = D_INDIRDEP;
1696 		newindirdep->ir_state = ATTACHED;
1697 		LIST_INIT(&newindirdep->ir_deplisthd);
1698 		LIST_INIT(&newindirdep->ir_donehd);
1699 		if (bp->b_bio2.bio_blkno == (daddr_t)-1) {
1700 			VOP_BMAP(bp->b_vp, bp->b_bio1.bio_blkno,
1701 				NULL, &bp->b_bio2.bio_blkno,
1702 				NULL, NULL);
1703 		}
1704 		KKASSERT(bp->b_bio2.bio_blkno != (daddr_t)-1);
1705 		newindirdep->ir_savebp =
1706 		    getblk(ip->i_devvp, bp->b_bio2.bio_blkno, bp->b_bcount,
1707 			   0, 0);
1708 		BUF_KERNPROC(newindirdep->ir_savebp);
1709 		bcopy(bp->b_data, newindirdep->ir_savebp->b_data, bp->b_bcount);
1710 	}
1711 }
1712 
1713 /*
1714  * Block de-allocation dependencies.
1715  *
1716  * When blocks are de-allocated, the on-disk pointers must be nullified before
1717  * the blocks are made available for use by other files.  (The true
1718  * requirement is that old pointers must be nullified before new on-disk
1719  * pointers are set.  We chose this slightly more stringent requirement to
1720  * reduce complexity.) Our implementation handles this dependency by updating
1721  * the inode (or indirect block) appropriately but delaying the actual block
1722  * de-allocation (i.e., freemap and free space count manipulation) until
1723  * after the updated versions reach stable storage.  After the disk is
1724  * updated, the blocks can be safely de-allocated whenever it is convenient.
1725  * This implementation handles only the common case of reducing a file's
1726  * length to zero. Other cases are handled by the conventional synchronous
1727  * write approach.
1728  *
1729  * The ffs implementation with which we worked double-checks
1730  * the state of the block pointers and file size as it reduces
1731  * a file's length.  Some of this code is replicated here in our
1732  * soft updates implementation.  The freeblks->fb_chkcnt field is
1733  * used to transfer a part of this information to the procedure
1734  * that eventually de-allocates the blocks.
1735  *
1736  * This routine should be called from the routine that shortens
1737  * a file's length, before the inode's size or block pointers
1738  * are modified. It will save the block pointer information for
1739  * later release and zero the inode so that the calling routine
1740  * can release it.
1741  */
1742 struct softdep_setup_freeblocks_info {
1743 	struct fs *fs;
1744 	struct inode *ip;
1745 };
1746 
1747 static int softdep_setup_freeblocks_bp(struct buf *bp, void *data);
1748 
1749 void
1750 softdep_setup_freeblocks(ip, length)
1751 	struct inode *ip;	/* The inode whose length is to be reduced */
1752 	off_t length;		/* The new length for the file */
1753 {
1754 	struct softdep_setup_freeblocks_info info;
1755 	struct freeblks *freeblks;
1756 	struct inodedep *inodedep;
1757 	struct allocdirect *adp;
1758 	struct vnode *vp;
1759 	struct buf *bp;
1760 	struct fs *fs;
1761 	int i, error, delay;
1762 	int count;
1763 
1764 	fs = ip->i_fs;
1765 	if (length != 0)
1766 		panic("softde_setup_freeblocks: non-zero length");
1767 	MALLOC(freeblks, struct freeblks *, sizeof(struct freeblks),
1768 		M_FREEBLKS, M_SOFTDEP_FLAGS);
1769 	bzero(freeblks, sizeof(struct freeblks));
1770 	freeblks->fb_list.wk_type = D_FREEBLKS;
1771 	freeblks->fb_state = ATTACHED;
1772 	freeblks->fb_uid = ip->i_uid;
1773 	freeblks->fb_previousinum = ip->i_number;
1774 	freeblks->fb_devvp = ip->i_devvp;
1775 	freeblks->fb_fs = fs;
1776 	freeblks->fb_oldsize = ip->i_size;
1777 	freeblks->fb_newsize = length;
1778 	freeblks->fb_chkcnt = ip->i_blocks;
1779 	for (i = 0; i < NDADDR; i++) {
1780 		freeblks->fb_dblks[i] = ip->i_db[i];
1781 		ip->i_db[i] = 0;
1782 	}
1783 	for (i = 0; i < NIADDR; i++) {
1784 		freeblks->fb_iblks[i] = ip->i_ib[i];
1785 		ip->i_ib[i] = 0;
1786 	}
1787 	ip->i_blocks = 0;
1788 	ip->i_size = 0;
1789 	/*
1790 	 * Push the zero'ed inode to to its disk buffer so that we are free
1791 	 * to delete its dependencies below. Once the dependencies are gone
1792 	 * the buffer can be safely released.
1793 	 */
1794 	if ((error = bread(ip->i_devvp,
1795 	    fsbtodb(fs, ino_to_fsba(fs, ip->i_number)),
1796 	    (int)fs->fs_bsize, &bp)) != 0)
1797 		softdep_error("softdep_setup_freeblocks", error);
1798 	*((struct dinode *)bp->b_data + ino_to_fsbo(fs, ip->i_number)) =
1799 	    ip->i_din;
1800 	/*
1801 	 * Find and eliminate any inode dependencies.
1802 	 */
1803 	ACQUIRE_LOCK(&lk);
1804 	(void) inodedep_lookup(fs, ip->i_number, DEPALLOC, &inodedep);
1805 	if ((inodedep->id_state & IOSTARTED) != 0) {
1806 		FREE_LOCK(&lk);
1807 		panic("softdep_setup_freeblocks: inode busy");
1808 	}
1809 	/*
1810 	 * Add the freeblks structure to the list of operations that
1811 	 * must await the zero'ed inode being written to disk. If we
1812 	 * still have a bitmap dependency (delay == 0), then the inode
1813 	 * has never been written to disk, so we can process the
1814 	 * freeblks below once we have deleted the dependencies.
1815 	 */
1816 	delay = (inodedep->id_state & DEPCOMPLETE);
1817 	if (delay)
1818 		WORKLIST_INSERT(&inodedep->id_bufwait, &freeblks->fb_list);
1819 	/*
1820 	 * Because the file length has been truncated to zero, any
1821 	 * pending block allocation dependency structures associated
1822 	 * with this inode are obsolete and can simply be de-allocated.
1823 	 * We must first merge the two dependency lists to get rid of
1824 	 * any duplicate freefrag structures, then purge the merged list.
1825 	 */
1826 	merge_inode_lists(inodedep);
1827 	while ((adp = TAILQ_FIRST(&inodedep->id_inoupdt)) != 0)
1828 		free_allocdirect(&inodedep->id_inoupdt, adp, 1);
1829 	FREE_LOCK(&lk);
1830 	bdwrite(bp);
1831 	/*
1832 	 * We must wait for any I/O in progress to finish so that
1833 	 * all potential buffers on the dirty list will be visible.
1834 	 * Once they are all there, walk the list and get rid of
1835 	 * any dependencies.
1836 	 */
1837 	vp = ITOV(ip);
1838 	ACQUIRE_LOCK(&lk);
1839 	drain_output(vp, 1);
1840 
1841 	info.fs = fs;
1842 	info.ip = ip;
1843 	crit_enter();
1844 	do {
1845 		count = RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree, NULL,
1846 				softdep_setup_freeblocks_bp, &info);
1847 	} while (count != 0);
1848 	crit_exit();
1849 	if (inodedep_lookup(fs, ip->i_number, 0, &inodedep) != 0)
1850 		(void)free_inodedep(inodedep);
1851 
1852 	if (delay) {
1853 		freeblks->fb_state |= DEPCOMPLETE;
1854 		/*
1855 		 * If the inode with zeroed block pointers is now on disk
1856 		 * we can start freeing blocks. Add freeblks to the worklist
1857 		 * instead of calling  handle_workitem_freeblocks directly as
1858 		 * it is more likely that additional IO is needed to complete
1859 		 * the request here than in the !delay case.
1860 		 */
1861 		if ((freeblks->fb_state & ALLCOMPLETE) == ALLCOMPLETE)
1862 			add_to_worklist(&freeblks->fb_list);
1863 	}
1864 
1865 	FREE_LOCK(&lk);
1866 	/*
1867 	 * If the inode has never been written to disk (delay == 0),
1868 	 * then we can process the freeblks now that we have deleted
1869 	 * the dependencies.
1870 	 */
1871 	if (!delay)
1872 		handle_workitem_freeblocks(freeblks);
1873 }
1874 
1875 static int
1876 softdep_setup_freeblocks_bp(struct buf *bp, void *data)
1877 {
1878 	struct softdep_setup_freeblocks_info *info = data;
1879 	struct inodedep *inodedep;
1880 
1881 	if (getdirtybuf(&bp, MNT_WAIT) == 0) {
1882 		printf("softdep_setup_freeblocks_bp(1): caught bp %p going away\n", bp);
1883 		return(-1);
1884 	}
1885 	if (bp->b_vp != ITOV(info->ip) || (bp->b_flags & B_DELWRI) == 0) {
1886 		printf("softdep_setup_freeblocks_bp(2): caught bp %p going away\n", bp);
1887 		BUF_UNLOCK(bp);
1888 		return(-1);
1889 	}
1890 	(void) inodedep_lookup(info->fs, info->ip->i_number, 0, &inodedep);
1891 	deallocate_dependencies(bp, inodedep);
1892 	bp->b_flags |= B_INVAL | B_NOCACHE;
1893 	FREE_LOCK(&lk);
1894 	brelse(bp);
1895 	ACQUIRE_LOCK(&lk);
1896 	return(1);
1897 }
1898 
1899 /*
1900  * Reclaim any dependency structures from a buffer that is about to
1901  * be reallocated to a new vnode. The buffer must be locked, thus,
1902  * no I/O completion operations can occur while we are manipulating
1903  * its associated dependencies. The mutex is held so that other I/O's
1904  * associated with related dependencies do not occur.
1905  */
1906 static void
1907 deallocate_dependencies(bp, inodedep)
1908 	struct buf *bp;
1909 	struct inodedep *inodedep;
1910 {
1911 	struct worklist *wk;
1912 	struct indirdep *indirdep;
1913 	struct allocindir *aip;
1914 	struct pagedep *pagedep;
1915 	struct dirrem *dirrem;
1916 	struct diradd *dap;
1917 	int i;
1918 
1919 	while ((wk = LIST_FIRST(&bp->b_dep)) != NULL) {
1920 		switch (wk->wk_type) {
1921 
1922 		case D_INDIRDEP:
1923 			indirdep = WK_INDIRDEP(wk);
1924 			/*
1925 			 * None of the indirect pointers will ever be visible,
1926 			 * so they can simply be tossed. GOINGAWAY ensures
1927 			 * that allocated pointers will be saved in the buffer
1928 			 * cache until they are freed. Note that they will
1929 			 * only be able to be found by their physical address
1930 			 * since the inode mapping the logical address will
1931 			 * be gone. The save buffer used for the safe copy
1932 			 * was allocated in setup_allocindir_phase2 using
1933 			 * the physical address so it could be used for this
1934 			 * purpose. Hence we swap the safe copy with the real
1935 			 * copy, allowing the safe copy to be freed and holding
1936 			 * on to the real copy for later use in indir_trunc.
1937 			 *
1938 			 * NOTE: ir_savebp is relative to the block device
1939 			 * so b_bio1 contains the device block number.
1940 			 */
1941 			if (indirdep->ir_state & GOINGAWAY) {
1942 				FREE_LOCK(&lk);
1943 				panic("deallocate_dependencies: already gone");
1944 			}
1945 			indirdep->ir_state |= GOINGAWAY;
1946 			while ((aip = LIST_FIRST(&indirdep->ir_deplisthd)) != 0)
1947 				free_allocindir(aip, inodedep);
1948 			if (bp->b_bio1.bio_blkno >= 0 ||
1949 			    bp->b_bio2.bio_blkno != indirdep->ir_savebp->b_bio1.bio_blkno) {
1950 				FREE_LOCK(&lk);
1951 				panic("deallocate_dependencies: not indir");
1952 			}
1953 			bcopy(bp->b_data, indirdep->ir_savebp->b_data,
1954 			    bp->b_bcount);
1955 			WORKLIST_REMOVE(wk);
1956 			WORKLIST_INSERT(&indirdep->ir_savebp->b_dep, wk);
1957 			continue;
1958 
1959 		case D_PAGEDEP:
1960 			pagedep = WK_PAGEDEP(wk);
1961 			/*
1962 			 * None of the directory additions will ever be
1963 			 * visible, so they can simply be tossed.
1964 			 */
1965 			for (i = 0; i < DAHASHSZ; i++)
1966 				while ((dap =
1967 				    LIST_FIRST(&pagedep->pd_diraddhd[i])))
1968 					free_diradd(dap);
1969 			while ((dap = LIST_FIRST(&pagedep->pd_pendinghd)) != 0)
1970 				free_diradd(dap);
1971 			/*
1972 			 * Copy any directory remove dependencies to the list
1973 			 * to be processed after the zero'ed inode is written.
1974 			 * If the inode has already been written, then they
1975 			 * can be dumped directly onto the work list.
1976 			 */
1977 			LIST_FOREACH(dirrem, &pagedep->pd_dirremhd, dm_next) {
1978 				LIST_REMOVE(dirrem, dm_next);
1979 				dirrem->dm_dirinum = pagedep->pd_ino;
1980 				if (inodedep == NULL ||
1981 				    (inodedep->id_state & ALLCOMPLETE) ==
1982 				     ALLCOMPLETE)
1983 					add_to_worklist(&dirrem->dm_list);
1984 				else
1985 					WORKLIST_INSERT(&inodedep->id_bufwait,
1986 					    &dirrem->dm_list);
1987 			}
1988 			WORKLIST_REMOVE(&pagedep->pd_list);
1989 			LIST_REMOVE(pagedep, pd_hash);
1990 			WORKITEM_FREE(pagedep, D_PAGEDEP);
1991 			continue;
1992 
1993 		case D_ALLOCINDIR:
1994 			free_allocindir(WK_ALLOCINDIR(wk), inodedep);
1995 			continue;
1996 
1997 		case D_ALLOCDIRECT:
1998 		case D_INODEDEP:
1999 			FREE_LOCK(&lk);
2000 			panic("deallocate_dependencies: Unexpected type %s",
2001 			    TYPENAME(wk->wk_type));
2002 			/* NOTREACHED */
2003 
2004 		default:
2005 			FREE_LOCK(&lk);
2006 			panic("deallocate_dependencies: Unknown type %s",
2007 			    TYPENAME(wk->wk_type));
2008 			/* NOTREACHED */
2009 		}
2010 	}
2011 }
2012 
2013 /*
2014  * Free an allocdirect. Generate a new freefrag work request if appropriate.
2015  * This routine must be called with splbio interrupts blocked.
2016  */
2017 static void
2018 free_allocdirect(adphead, adp, delay)
2019 	struct allocdirectlst *adphead;
2020 	struct allocdirect *adp;
2021 	int delay;
2022 {
2023 
2024 #ifdef DEBUG
2025 	if (lk.lkt_held == NOHOLDER)
2026 		panic("free_allocdirect: lock not held");
2027 #endif
2028 	if ((adp->ad_state & DEPCOMPLETE) == 0)
2029 		LIST_REMOVE(adp, ad_deps);
2030 	TAILQ_REMOVE(adphead, adp, ad_next);
2031 	if ((adp->ad_state & COMPLETE) == 0)
2032 		WORKLIST_REMOVE(&adp->ad_list);
2033 	if (adp->ad_freefrag != NULL) {
2034 		if (delay)
2035 			WORKLIST_INSERT(&adp->ad_inodedep->id_bufwait,
2036 			    &adp->ad_freefrag->ff_list);
2037 		else
2038 			add_to_worklist(&adp->ad_freefrag->ff_list);
2039 	}
2040 	WORKITEM_FREE(adp, D_ALLOCDIRECT);
2041 }
2042 
2043 /*
2044  * Prepare an inode to be freed. The actual free operation is not
2045  * done until the zero'ed inode has been written to disk.
2046  */
2047 void
2048 softdep_freefile(pvp, ino, mode)
2049 		struct vnode *pvp;
2050 		ino_t ino;
2051 		int mode;
2052 {
2053 	struct inode *ip = VTOI(pvp);
2054 	struct inodedep *inodedep;
2055 	struct freefile *freefile;
2056 
2057 	/*
2058 	 * This sets up the inode de-allocation dependency.
2059 	 */
2060 	MALLOC(freefile, struct freefile *, sizeof(struct freefile),
2061 		M_FREEFILE, M_SOFTDEP_FLAGS);
2062 	freefile->fx_list.wk_type = D_FREEFILE;
2063 	freefile->fx_list.wk_state = 0;
2064 	freefile->fx_mode = mode;
2065 	freefile->fx_oldinum = ino;
2066 	freefile->fx_devvp = ip->i_devvp;
2067 	freefile->fx_fs = ip->i_fs;
2068 
2069 	/*
2070 	 * If the inodedep does not exist, then the zero'ed inode has
2071 	 * been written to disk. If the allocated inode has never been
2072 	 * written to disk, then the on-disk inode is zero'ed. In either
2073 	 * case we can free the file immediately.
2074 	 */
2075 	ACQUIRE_LOCK(&lk);
2076 	if (inodedep_lookup(ip->i_fs, ino, 0, &inodedep) == 0 ||
2077 	    check_inode_unwritten(inodedep)) {
2078 		FREE_LOCK(&lk);
2079 		handle_workitem_freefile(freefile);
2080 		return;
2081 	}
2082 	WORKLIST_INSERT(&inodedep->id_inowait, &freefile->fx_list);
2083 	FREE_LOCK(&lk);
2084 }
2085 
2086 /*
2087  * Check to see if an inode has never been written to disk. If
2088  * so free the inodedep and return success, otherwise return failure.
2089  * This routine must be called with splbio interrupts blocked.
2090  *
2091  * If we still have a bitmap dependency, then the inode has never
2092  * been written to disk. Drop the dependency as it is no longer
2093  * necessary since the inode is being deallocated. We set the
2094  * ALLCOMPLETE flags since the bitmap now properly shows that the
2095  * inode is not allocated. Even if the inode is actively being
2096  * written, it has been rolled back to its zero'ed state, so we
2097  * are ensured that a zero inode is what is on the disk. For short
2098  * lived files, this change will usually result in removing all the
2099  * dependencies from the inode so that it can be freed immediately.
2100  */
2101 static int
2102 check_inode_unwritten(inodedep)
2103 	struct inodedep *inodedep;
2104 {
2105 
2106 	if ((inodedep->id_state & DEPCOMPLETE) != 0 ||
2107 	    LIST_FIRST(&inodedep->id_pendinghd) != NULL ||
2108 	    LIST_FIRST(&inodedep->id_bufwait) != NULL ||
2109 	    LIST_FIRST(&inodedep->id_inowait) != NULL ||
2110 	    TAILQ_FIRST(&inodedep->id_inoupdt) != NULL ||
2111 	    TAILQ_FIRST(&inodedep->id_newinoupdt) != NULL ||
2112 	    inodedep->id_nlinkdelta != 0)
2113 		return (0);
2114 
2115 	/*
2116 	 * Another process might be in initiate_write_inodeblock
2117 	 * trying to allocate memory without holding "Softdep Lock".
2118 	 */
2119 	if ((inodedep->id_state & IOSTARTED) != 0 &&
2120 	    inodedep->id_savedino == NULL)
2121 		return(0);
2122 
2123 	inodedep->id_state |= ALLCOMPLETE;
2124 	LIST_REMOVE(inodedep, id_deps);
2125 	inodedep->id_buf = NULL;
2126 	if (inodedep->id_state & ONWORKLIST)
2127 		WORKLIST_REMOVE(&inodedep->id_list);
2128 	if (inodedep->id_savedino != NULL) {
2129 		FREE(inodedep->id_savedino, M_INODEDEP);
2130 		inodedep->id_savedino = NULL;
2131 	}
2132 	if (free_inodedep(inodedep) == 0) {
2133 		FREE_LOCK(&lk);
2134 		panic("check_inode_unwritten: busy inode");
2135 	}
2136 	return (1);
2137 }
2138 
2139 /*
2140  * Try to free an inodedep structure. Return 1 if it could be freed.
2141  */
2142 static int
2143 free_inodedep(inodedep)
2144 	struct inodedep *inodedep;
2145 {
2146 
2147 	if ((inodedep->id_state & ONWORKLIST) != 0 ||
2148 	    (inodedep->id_state & ALLCOMPLETE) != ALLCOMPLETE ||
2149 	    LIST_FIRST(&inodedep->id_pendinghd) != NULL ||
2150 	    LIST_FIRST(&inodedep->id_bufwait) != NULL ||
2151 	    LIST_FIRST(&inodedep->id_inowait) != NULL ||
2152 	    TAILQ_FIRST(&inodedep->id_inoupdt) != NULL ||
2153 	    TAILQ_FIRST(&inodedep->id_newinoupdt) != NULL ||
2154 	    inodedep->id_nlinkdelta != 0 || inodedep->id_savedino != NULL)
2155 		return (0);
2156 	LIST_REMOVE(inodedep, id_hash);
2157 	WORKITEM_FREE(inodedep, D_INODEDEP);
2158 	num_inodedep -= 1;
2159 	return (1);
2160 }
2161 
2162 /*
2163  * This workitem routine performs the block de-allocation.
2164  * The workitem is added to the pending list after the updated
2165  * inode block has been written to disk.  As mentioned above,
2166  * checks regarding the number of blocks de-allocated (compared
2167  * to the number of blocks allocated for the file) are also
2168  * performed in this function.
2169  */
2170 static void
2171 handle_workitem_freeblocks(freeblks)
2172 	struct freeblks *freeblks;
2173 {
2174 	struct inode tip;
2175 	ufs_daddr_t bn;
2176 	struct fs *fs;
2177 	int i, level, bsize;
2178 	long nblocks, blocksreleased = 0;
2179 	int error, allerror = 0;
2180 	ufs_lbn_t baselbns[NIADDR], tmpval;
2181 
2182 	tip.i_number = freeblks->fb_previousinum;
2183 	tip.i_devvp = freeblks->fb_devvp;
2184 	tip.i_dev = freeblks->fb_devvp->v_rdev;
2185 	tip.i_fs = freeblks->fb_fs;
2186 	tip.i_size = freeblks->fb_oldsize;
2187 	tip.i_uid = freeblks->fb_uid;
2188 	fs = freeblks->fb_fs;
2189 	tmpval = 1;
2190 	baselbns[0] = NDADDR;
2191 	for (i = 1; i < NIADDR; i++) {
2192 		tmpval *= NINDIR(fs);
2193 		baselbns[i] = baselbns[i - 1] + tmpval;
2194 	}
2195 	nblocks = btodb(fs->fs_bsize);
2196 	blocksreleased = 0;
2197 	/*
2198 	 * Indirect blocks first.
2199 	 */
2200 	for (level = (NIADDR - 1); level >= 0; level--) {
2201 		if ((bn = freeblks->fb_iblks[level]) == 0)
2202 			continue;
2203 		if ((error = indir_trunc(&tip, fsbtodb(fs, bn), level,
2204 		    baselbns[level], &blocksreleased)) == 0)
2205 			allerror = error;
2206 		ffs_blkfree(&tip, bn, fs->fs_bsize);
2207 		blocksreleased += nblocks;
2208 	}
2209 	/*
2210 	 * All direct blocks or frags.
2211 	 */
2212 	for (i = (NDADDR - 1); i >= 0; i--) {
2213 		if ((bn = freeblks->fb_dblks[i]) == 0)
2214 			continue;
2215 		bsize = blksize(fs, &tip, i);
2216 		ffs_blkfree(&tip, bn, bsize);
2217 		blocksreleased += btodb(bsize);
2218 	}
2219 
2220 #ifdef DIAGNOSTIC
2221 	if (freeblks->fb_chkcnt != blocksreleased)
2222 		printf("handle_workitem_freeblocks: block count\n");
2223 	if (allerror)
2224 		softdep_error("handle_workitem_freeblks", allerror);
2225 #endif /* DIAGNOSTIC */
2226 	WORKITEM_FREE(freeblks, D_FREEBLKS);
2227 }
2228 
2229 /*
2230  * Release blocks associated with the inode ip and stored in the indirect
2231  * block dbn. If level is greater than SINGLE, the block is an indirect block
2232  * and recursive calls to indirtrunc must be used to cleanse other indirect
2233  * blocks.
2234  */
2235 static int
2236 indir_trunc(ip, dbn, level, lbn, countp)
2237 	struct inode *ip;
2238 	ufs_daddr_t dbn;
2239 	int level;
2240 	ufs_lbn_t lbn;
2241 	long *countp;
2242 {
2243 	struct buf *bp;
2244 	ufs_daddr_t *bap;
2245 	ufs_daddr_t nb;
2246 	struct fs *fs;
2247 	struct worklist *wk;
2248 	struct indirdep *indirdep;
2249 	int i, lbnadd, nblocks;
2250 	int error, allerror = 0;
2251 
2252 	fs = ip->i_fs;
2253 	lbnadd = 1;
2254 	for (i = level; i > 0; i--)
2255 		lbnadd *= NINDIR(fs);
2256 	/*
2257 	 * Get buffer of block pointers to be freed. This routine is not
2258 	 * called until the zero'ed inode has been written, so it is safe
2259 	 * to free blocks as they are encountered. Because the inode has
2260 	 * been zero'ed, calls to bmap on these blocks will fail. So, we
2261 	 * have to use the on-disk address and the block device for the
2262 	 * filesystem to look them up. If the file was deleted before its
2263 	 * indirect blocks were all written to disk, the routine that set
2264 	 * us up (deallocate_dependencies) will have arranged to leave
2265 	 * a complete copy of the indirect block in memory for our use.
2266 	 * Otherwise we have to read the blocks in from the disk.
2267 	 */
2268 	ACQUIRE_LOCK(&lk);
2269 	if ((bp = incore(ip->i_devvp, dbn)) != NULL &&
2270 	    (wk = LIST_FIRST(&bp->b_dep)) != NULL) {
2271 		if (wk->wk_type != D_INDIRDEP ||
2272 		    (indirdep = WK_INDIRDEP(wk))->ir_savebp != bp ||
2273 		    (indirdep->ir_state & GOINGAWAY) == 0) {
2274 			FREE_LOCK(&lk);
2275 			panic("indir_trunc: lost indirdep");
2276 		}
2277 		WORKLIST_REMOVE(wk);
2278 		WORKITEM_FREE(indirdep, D_INDIRDEP);
2279 		if (LIST_FIRST(&bp->b_dep) != NULL) {
2280 			FREE_LOCK(&lk);
2281 			panic("indir_trunc: dangling dep");
2282 		}
2283 		FREE_LOCK(&lk);
2284 	} else {
2285 		FREE_LOCK(&lk);
2286 		error = bread(ip->i_devvp, dbn, (int)fs->fs_bsize, &bp);
2287 		if (error)
2288 			return (error);
2289 	}
2290 	/*
2291 	 * Recursively free indirect blocks.
2292 	 */
2293 	bap = (ufs_daddr_t *)bp->b_data;
2294 	nblocks = btodb(fs->fs_bsize);
2295 	for (i = NINDIR(fs) - 1; i >= 0; i--) {
2296 		if ((nb = bap[i]) == 0)
2297 			continue;
2298 		if (level != 0) {
2299 			if ((error = indir_trunc(ip, fsbtodb(fs, nb),
2300 			     level - 1, lbn + (i * lbnadd), countp)) != 0)
2301 				allerror = error;
2302 		}
2303 		ffs_blkfree(ip, nb, fs->fs_bsize);
2304 		*countp += nblocks;
2305 	}
2306 	bp->b_flags |= B_INVAL | B_NOCACHE;
2307 	brelse(bp);
2308 	return (allerror);
2309 }
2310 
2311 /*
2312  * Free an allocindir.
2313  * This routine must be called with splbio interrupts blocked.
2314  */
2315 static void
2316 free_allocindir(aip, inodedep)
2317 	struct allocindir *aip;
2318 	struct inodedep *inodedep;
2319 {
2320 	struct freefrag *freefrag;
2321 
2322 #ifdef DEBUG
2323 	if (lk.lkt_held == NOHOLDER)
2324 		panic("free_allocindir: lock not held");
2325 #endif
2326 	if ((aip->ai_state & DEPCOMPLETE) == 0)
2327 		LIST_REMOVE(aip, ai_deps);
2328 	if (aip->ai_state & ONWORKLIST)
2329 		WORKLIST_REMOVE(&aip->ai_list);
2330 	LIST_REMOVE(aip, ai_next);
2331 	if ((freefrag = aip->ai_freefrag) != NULL) {
2332 		if (inodedep == NULL)
2333 			add_to_worklist(&freefrag->ff_list);
2334 		else
2335 			WORKLIST_INSERT(&inodedep->id_bufwait,
2336 			    &freefrag->ff_list);
2337 	}
2338 	WORKITEM_FREE(aip, D_ALLOCINDIR);
2339 }
2340 
2341 /*
2342  * Directory entry addition dependencies.
2343  *
2344  * When adding a new directory entry, the inode (with its incremented link
2345  * count) must be written to disk before the directory entry's pointer to it.
2346  * Also, if the inode is newly allocated, the corresponding freemap must be
2347  * updated (on disk) before the directory entry's pointer. These requirements
2348  * are met via undo/redo on the directory entry's pointer, which consists
2349  * simply of the inode number.
2350  *
2351  * As directory entries are added and deleted, the free space within a
2352  * directory block can become fragmented.  The ufs filesystem will compact
2353  * a fragmented directory block to make space for a new entry. When this
2354  * occurs, the offsets of previously added entries change. Any "diradd"
2355  * dependency structures corresponding to these entries must be updated with
2356  * the new offsets.
2357  */
2358 
2359 /*
2360  * This routine is called after the in-memory inode's link
2361  * count has been incremented, but before the directory entry's
2362  * pointer to the inode has been set.
2363  */
2364 void
2365 softdep_setup_directory_add(bp, dp, diroffset, newinum, newdirbp)
2366 	struct buf *bp;		/* buffer containing directory block */
2367 	struct inode *dp;	/* inode for directory */
2368 	off_t diroffset;	/* offset of new entry in directory */
2369 	ino_t newinum;		/* inode referenced by new directory entry */
2370 	struct buf *newdirbp;	/* non-NULL => contents of new mkdir */
2371 {
2372 	int offset;		/* offset of new entry within directory block */
2373 	ufs_lbn_t lbn;		/* block in directory containing new entry */
2374 	struct fs *fs;
2375 	struct diradd *dap;
2376 	struct pagedep *pagedep;
2377 	struct inodedep *inodedep;
2378 	struct mkdir *mkdir1, *mkdir2;
2379 
2380 	/*
2381 	 * Whiteouts have no dependencies.
2382 	 */
2383 	if (newinum == WINO) {
2384 		if (newdirbp != NULL)
2385 			bdwrite(newdirbp);
2386 		return;
2387 	}
2388 
2389 	fs = dp->i_fs;
2390 	lbn = lblkno(fs, diroffset);
2391 	offset = blkoff(fs, diroffset);
2392 	MALLOC(dap, struct diradd *, sizeof(struct diradd), M_DIRADD,
2393 	    M_SOFTDEP_FLAGS);
2394 	bzero(dap, sizeof(struct diradd));
2395 	dap->da_list.wk_type = D_DIRADD;
2396 	dap->da_offset = offset;
2397 	dap->da_newinum = newinum;
2398 	dap->da_state = ATTACHED;
2399 	if (newdirbp == NULL) {
2400 		dap->da_state |= DEPCOMPLETE;
2401 		ACQUIRE_LOCK(&lk);
2402 	} else {
2403 		dap->da_state |= MKDIR_BODY | MKDIR_PARENT;
2404 		MALLOC(mkdir1, struct mkdir *, sizeof(struct mkdir), M_MKDIR,
2405 		    M_SOFTDEP_FLAGS);
2406 		mkdir1->md_list.wk_type = D_MKDIR;
2407 		mkdir1->md_state = MKDIR_BODY;
2408 		mkdir1->md_diradd = dap;
2409 		MALLOC(mkdir2, struct mkdir *, sizeof(struct mkdir), M_MKDIR,
2410 		    M_SOFTDEP_FLAGS);
2411 		mkdir2->md_list.wk_type = D_MKDIR;
2412 		mkdir2->md_state = MKDIR_PARENT;
2413 		mkdir2->md_diradd = dap;
2414 		/*
2415 		 * Dependency on "." and ".." being written to disk.
2416 		 */
2417 		mkdir1->md_buf = newdirbp;
2418 		ACQUIRE_LOCK(&lk);
2419 		LIST_INSERT_HEAD(&mkdirlisthd, mkdir1, md_mkdirs);
2420 		WORKLIST_INSERT(&newdirbp->b_dep, &mkdir1->md_list);
2421 		FREE_LOCK(&lk);
2422 		bdwrite(newdirbp);
2423 		/*
2424 		 * Dependency on link count increase for parent directory
2425 		 */
2426 		ACQUIRE_LOCK(&lk);
2427 		if (inodedep_lookup(dp->i_fs, dp->i_number, 0, &inodedep) == 0
2428 		    || (inodedep->id_state & ALLCOMPLETE) == ALLCOMPLETE) {
2429 			dap->da_state &= ~MKDIR_PARENT;
2430 			WORKITEM_FREE(mkdir2, D_MKDIR);
2431 		} else {
2432 			LIST_INSERT_HEAD(&mkdirlisthd, mkdir2, md_mkdirs);
2433 			WORKLIST_INSERT(&inodedep->id_bufwait,&mkdir2->md_list);
2434 		}
2435 	}
2436 	/*
2437 	 * Link into parent directory pagedep to await its being written.
2438 	 */
2439 	if (pagedep_lookup(dp, lbn, DEPALLOC, &pagedep) == 0)
2440 		WORKLIST_INSERT(&bp->b_dep, &pagedep->pd_list);
2441 	dap->da_pagedep = pagedep;
2442 	LIST_INSERT_HEAD(&pagedep->pd_diraddhd[DIRADDHASH(offset)], dap,
2443 	    da_pdlist);
2444 	/*
2445 	 * Link into its inodedep. Put it on the id_bufwait list if the inode
2446 	 * is not yet written. If it is written, do the post-inode write
2447 	 * processing to put it on the id_pendinghd list.
2448 	 */
2449 	(void) inodedep_lookup(fs, newinum, DEPALLOC, &inodedep);
2450 	if ((inodedep->id_state & ALLCOMPLETE) == ALLCOMPLETE)
2451 		diradd_inode_written(dap, inodedep);
2452 	else
2453 		WORKLIST_INSERT(&inodedep->id_bufwait, &dap->da_list);
2454 	FREE_LOCK(&lk);
2455 }
2456 
2457 /*
2458  * This procedure is called to change the offset of a directory
2459  * entry when compacting a directory block which must be owned
2460  * exclusively by the caller. Note that the actual entry movement
2461  * must be done in this procedure to ensure that no I/O completions
2462  * occur while the move is in progress.
2463  */
2464 void
2465 softdep_change_directoryentry_offset(dp, base, oldloc, newloc, entrysize)
2466 	struct inode *dp;	/* inode for directory */
2467 	caddr_t base;		/* address of dp->i_offset */
2468 	caddr_t oldloc;		/* address of old directory location */
2469 	caddr_t newloc;		/* address of new directory location */
2470 	int entrysize;		/* size of directory entry */
2471 {
2472 	int offset, oldoffset, newoffset;
2473 	struct pagedep *pagedep;
2474 	struct diradd *dap;
2475 	ufs_lbn_t lbn;
2476 
2477 	ACQUIRE_LOCK(&lk);
2478 	lbn = lblkno(dp->i_fs, dp->i_offset);
2479 	offset = blkoff(dp->i_fs, dp->i_offset);
2480 	if (pagedep_lookup(dp, lbn, 0, &pagedep) == 0)
2481 		goto done;
2482 	oldoffset = offset + (oldloc - base);
2483 	newoffset = offset + (newloc - base);
2484 
2485 	LIST_FOREACH(dap, &pagedep->pd_diraddhd[DIRADDHASH(oldoffset)], da_pdlist) {
2486 		if (dap->da_offset != oldoffset)
2487 			continue;
2488 		dap->da_offset = newoffset;
2489 		if (DIRADDHASH(newoffset) == DIRADDHASH(oldoffset))
2490 			break;
2491 		LIST_REMOVE(dap, da_pdlist);
2492 		LIST_INSERT_HEAD(&pagedep->pd_diraddhd[DIRADDHASH(newoffset)],
2493 		    dap, da_pdlist);
2494 		break;
2495 	}
2496 	if (dap == NULL) {
2497 
2498 		LIST_FOREACH(dap, &pagedep->pd_pendinghd, da_pdlist) {
2499 			if (dap->da_offset == oldoffset) {
2500 				dap->da_offset = newoffset;
2501 				break;
2502 			}
2503 		}
2504 	}
2505 done:
2506 	bcopy(oldloc, newloc, entrysize);
2507 	FREE_LOCK(&lk);
2508 }
2509 
2510 /*
2511  * Free a diradd dependency structure. This routine must be called
2512  * with splbio interrupts blocked.
2513  */
2514 static void
2515 free_diradd(dap)
2516 	struct diradd *dap;
2517 {
2518 	struct dirrem *dirrem;
2519 	struct pagedep *pagedep;
2520 	struct inodedep *inodedep;
2521 	struct mkdir *mkdir, *nextmd;
2522 
2523 #ifdef DEBUG
2524 	if (lk.lkt_held == NOHOLDER)
2525 		panic("free_diradd: lock not held");
2526 #endif
2527 	WORKLIST_REMOVE(&dap->da_list);
2528 	LIST_REMOVE(dap, da_pdlist);
2529 	if ((dap->da_state & DIRCHG) == 0) {
2530 		pagedep = dap->da_pagedep;
2531 	} else {
2532 		dirrem = dap->da_previous;
2533 		pagedep = dirrem->dm_pagedep;
2534 		dirrem->dm_dirinum = pagedep->pd_ino;
2535 		add_to_worklist(&dirrem->dm_list);
2536 	}
2537 	if (inodedep_lookup(VFSTOUFS(pagedep->pd_mnt)->um_fs, dap->da_newinum,
2538 	    0, &inodedep) != 0)
2539 		(void) free_inodedep(inodedep);
2540 	if ((dap->da_state & (MKDIR_PARENT | MKDIR_BODY)) != 0) {
2541 		for (mkdir = LIST_FIRST(&mkdirlisthd); mkdir; mkdir = nextmd) {
2542 			nextmd = LIST_NEXT(mkdir, md_mkdirs);
2543 			if (mkdir->md_diradd != dap)
2544 				continue;
2545 			dap->da_state &= ~mkdir->md_state;
2546 			WORKLIST_REMOVE(&mkdir->md_list);
2547 			LIST_REMOVE(mkdir, md_mkdirs);
2548 			WORKITEM_FREE(mkdir, D_MKDIR);
2549 		}
2550 		if ((dap->da_state & (MKDIR_PARENT | MKDIR_BODY)) != 0) {
2551 			FREE_LOCK(&lk);
2552 			panic("free_diradd: unfound ref");
2553 		}
2554 	}
2555 	WORKITEM_FREE(dap, D_DIRADD);
2556 }
2557 
2558 /*
2559  * Directory entry removal dependencies.
2560  *
2561  * When removing a directory entry, the entry's inode pointer must be
2562  * zero'ed on disk before the corresponding inode's link count is decremented
2563  * (possibly freeing the inode for re-use). This dependency is handled by
2564  * updating the directory entry but delaying the inode count reduction until
2565  * after the directory block has been written to disk. After this point, the
2566  * inode count can be decremented whenever it is convenient.
2567  */
2568 
2569 /*
2570  * This routine should be called immediately after removing
2571  * a directory entry.  The inode's link count should not be
2572  * decremented by the calling procedure -- the soft updates
2573  * code will do this task when it is safe.
2574  */
2575 void
2576 softdep_setup_remove(bp, dp, ip, isrmdir)
2577 	struct buf *bp;		/* buffer containing directory block */
2578 	struct inode *dp;	/* inode for the directory being modified */
2579 	struct inode *ip;	/* inode for directory entry being removed */
2580 	int isrmdir;		/* indicates if doing RMDIR */
2581 {
2582 	struct dirrem *dirrem, *prevdirrem;
2583 
2584 	/*
2585 	 * Allocate a new dirrem if appropriate and ACQUIRE_LOCK.
2586 	 */
2587 	dirrem = newdirrem(bp, dp, ip, isrmdir, &prevdirrem);
2588 
2589 	/*
2590 	 * If the COMPLETE flag is clear, then there were no active
2591 	 * entries and we want to roll back to a zeroed entry until
2592 	 * the new inode is committed to disk. If the COMPLETE flag is
2593 	 * set then we have deleted an entry that never made it to
2594 	 * disk. If the entry we deleted resulted from a name change,
2595 	 * then the old name still resides on disk. We cannot delete
2596 	 * its inode (returned to us in prevdirrem) until the zeroed
2597 	 * directory entry gets to disk. The new inode has never been
2598 	 * referenced on the disk, so can be deleted immediately.
2599 	 */
2600 	if ((dirrem->dm_state & COMPLETE) == 0) {
2601 		LIST_INSERT_HEAD(&dirrem->dm_pagedep->pd_dirremhd, dirrem,
2602 		    dm_next);
2603 		FREE_LOCK(&lk);
2604 	} else {
2605 		if (prevdirrem != NULL)
2606 			LIST_INSERT_HEAD(&dirrem->dm_pagedep->pd_dirremhd,
2607 			    prevdirrem, dm_next);
2608 		dirrem->dm_dirinum = dirrem->dm_pagedep->pd_ino;
2609 		FREE_LOCK(&lk);
2610 		handle_workitem_remove(dirrem);
2611 	}
2612 }
2613 
2614 /*
2615  * Allocate a new dirrem if appropriate and return it along with
2616  * its associated pagedep. Called without a lock, returns with lock.
2617  */
2618 static long num_dirrem;		/* number of dirrem allocated */
2619 static struct dirrem *
2620 newdirrem(bp, dp, ip, isrmdir, prevdirremp)
2621 	struct buf *bp;		/* buffer containing directory block */
2622 	struct inode *dp;	/* inode for the directory being modified */
2623 	struct inode *ip;	/* inode for directory entry being removed */
2624 	int isrmdir;		/* indicates if doing RMDIR */
2625 	struct dirrem **prevdirremp; /* previously referenced inode, if any */
2626 {
2627 	int offset;
2628 	ufs_lbn_t lbn;
2629 	struct diradd *dap;
2630 	struct dirrem *dirrem;
2631 	struct pagedep *pagedep;
2632 
2633 	/*
2634 	 * Whiteouts have no deletion dependencies.
2635 	 */
2636 	if (ip == NULL)
2637 		panic("newdirrem: whiteout");
2638 	/*
2639 	 * If we are over our limit, try to improve the situation.
2640 	 * Limiting the number of dirrem structures will also limit
2641 	 * the number of freefile and freeblks structures.
2642 	 */
2643 	if (num_dirrem > max_softdeps / 2 && speedup_syncer() == 0)
2644 		(void) request_cleanup(FLUSH_REMOVE, 0);
2645 	num_dirrem += 1;
2646 	MALLOC(dirrem, struct dirrem *, sizeof(struct dirrem),
2647 		M_DIRREM, M_SOFTDEP_FLAGS);
2648 	bzero(dirrem, sizeof(struct dirrem));
2649 	dirrem->dm_list.wk_type = D_DIRREM;
2650 	dirrem->dm_state = isrmdir ? RMDIR : 0;
2651 	dirrem->dm_mnt = ITOV(ip)->v_mount;
2652 	dirrem->dm_oldinum = ip->i_number;
2653 	*prevdirremp = NULL;
2654 
2655 	ACQUIRE_LOCK(&lk);
2656 	lbn = lblkno(dp->i_fs, dp->i_offset);
2657 	offset = blkoff(dp->i_fs, dp->i_offset);
2658 	if (pagedep_lookup(dp, lbn, DEPALLOC, &pagedep) == 0)
2659 		WORKLIST_INSERT(&bp->b_dep, &pagedep->pd_list);
2660 	dirrem->dm_pagedep = pagedep;
2661 	/*
2662 	 * Check for a diradd dependency for the same directory entry.
2663 	 * If present, then both dependencies become obsolete and can
2664 	 * be de-allocated. Check for an entry on both the pd_dirraddhd
2665 	 * list and the pd_pendinghd list.
2666 	 */
2667 
2668 	LIST_FOREACH(dap, &pagedep->pd_diraddhd[DIRADDHASH(offset)], da_pdlist)
2669 		if (dap->da_offset == offset)
2670 			break;
2671 	if (dap == NULL) {
2672 
2673 		LIST_FOREACH(dap, &pagedep->pd_pendinghd, da_pdlist)
2674 			if (dap->da_offset == offset)
2675 				break;
2676 		if (dap == NULL)
2677 			return (dirrem);
2678 	}
2679 	/*
2680 	 * Must be ATTACHED at this point.
2681 	 */
2682 	if ((dap->da_state & ATTACHED) == 0) {
2683 		FREE_LOCK(&lk);
2684 		panic("newdirrem: not ATTACHED");
2685 	}
2686 	if (dap->da_newinum != ip->i_number) {
2687 		FREE_LOCK(&lk);
2688 		panic("newdirrem: inum %"PRId64" should be %"PRId64,
2689 		    ip->i_number, dap->da_newinum);
2690 	}
2691 	/*
2692 	 * If we are deleting a changed name that never made it to disk,
2693 	 * then return the dirrem describing the previous inode (which
2694 	 * represents the inode currently referenced from this entry on disk).
2695 	 */
2696 	if ((dap->da_state & DIRCHG) != 0) {
2697 		*prevdirremp = dap->da_previous;
2698 		dap->da_state &= ~DIRCHG;
2699 		dap->da_pagedep = pagedep;
2700 	}
2701 	/*
2702 	 * We are deleting an entry that never made it to disk.
2703 	 * Mark it COMPLETE so we can delete its inode immediately.
2704 	 */
2705 	dirrem->dm_state |= COMPLETE;
2706 	free_diradd(dap);
2707 	return (dirrem);
2708 }
2709 
2710 /*
2711  * Directory entry change dependencies.
2712  *
2713  * Changing an existing directory entry requires that an add operation
2714  * be completed first followed by a deletion. The semantics for the addition
2715  * are identical to the description of adding a new entry above except
2716  * that the rollback is to the old inode number rather than zero. Once
2717  * the addition dependency is completed, the removal is done as described
2718  * in the removal routine above.
2719  */
2720 
2721 /*
2722  * This routine should be called immediately after changing
2723  * a directory entry.  The inode's link count should not be
2724  * decremented by the calling procedure -- the soft updates
2725  * code will perform this task when it is safe.
2726  */
2727 void
2728 softdep_setup_directory_change(bp, dp, ip, newinum, isrmdir)
2729 	struct buf *bp;		/* buffer containing directory block */
2730 	struct inode *dp;	/* inode for the directory being modified */
2731 	struct inode *ip;	/* inode for directory entry being removed */
2732 	ino_t newinum;		/* new inode number for changed entry */
2733 	int isrmdir;		/* indicates if doing RMDIR */
2734 {
2735 	int offset;
2736 	struct diradd *dap = NULL;
2737 	struct dirrem *dirrem, *prevdirrem;
2738 	struct pagedep *pagedep;
2739 	struct inodedep *inodedep;
2740 
2741 	offset = blkoff(dp->i_fs, dp->i_offset);
2742 
2743 	/*
2744 	 * Whiteouts do not need diradd dependencies.
2745 	 */
2746 	if (newinum != WINO) {
2747 		MALLOC(dap, struct diradd *, sizeof(struct diradd),
2748 		    M_DIRADD, M_SOFTDEP_FLAGS);
2749 		bzero(dap, sizeof(struct diradd));
2750 		dap->da_list.wk_type = D_DIRADD;
2751 		dap->da_state = DIRCHG | ATTACHED | DEPCOMPLETE;
2752 		dap->da_offset = offset;
2753 		dap->da_newinum = newinum;
2754 	}
2755 
2756 	/*
2757 	 * Allocate a new dirrem and ACQUIRE_LOCK.
2758 	 */
2759 	dirrem = newdirrem(bp, dp, ip, isrmdir, &prevdirrem);
2760 	pagedep = dirrem->dm_pagedep;
2761 	/*
2762 	 * The possible values for isrmdir:
2763 	 *	0 - non-directory file rename
2764 	 *	1 - directory rename within same directory
2765 	 *   inum - directory rename to new directory of given inode number
2766 	 * When renaming to a new directory, we are both deleting and
2767 	 * creating a new directory entry, so the link count on the new
2768 	 * directory should not change. Thus we do not need the followup
2769 	 * dirrem which is usually done in handle_workitem_remove. We set
2770 	 * the DIRCHG flag to tell handle_workitem_remove to skip the
2771 	 * followup dirrem.
2772 	 */
2773 	if (isrmdir > 1)
2774 		dirrem->dm_state |= DIRCHG;
2775 
2776 	/*
2777 	 * Whiteouts have no additional dependencies,
2778 	 * so just put the dirrem on the correct list.
2779 	 */
2780 	if (newinum == WINO) {
2781 		if ((dirrem->dm_state & COMPLETE) == 0) {
2782 			LIST_INSERT_HEAD(&pagedep->pd_dirremhd, dirrem,
2783 			    dm_next);
2784 		} else {
2785 			dirrem->dm_dirinum = pagedep->pd_ino;
2786 			add_to_worklist(&dirrem->dm_list);
2787 		}
2788 		FREE_LOCK(&lk);
2789 		return;
2790 	}
2791 
2792 	/*
2793 	 * If the COMPLETE flag is clear, then there were no active
2794 	 * entries and we want to roll back to the previous inode until
2795 	 * the new inode is committed to disk. If the COMPLETE flag is
2796 	 * set, then we have deleted an entry that never made it to disk.
2797 	 * If the entry we deleted resulted from a name change, then the old
2798 	 * inode reference still resides on disk. Any rollback that we do
2799 	 * needs to be to that old inode (returned to us in prevdirrem). If
2800 	 * the entry we deleted resulted from a create, then there is
2801 	 * no entry on the disk, so we want to roll back to zero rather
2802 	 * than the uncommitted inode. In either of the COMPLETE cases we
2803 	 * want to immediately free the unwritten and unreferenced inode.
2804 	 */
2805 	if ((dirrem->dm_state & COMPLETE) == 0) {
2806 		dap->da_previous = dirrem;
2807 	} else {
2808 		if (prevdirrem != NULL) {
2809 			dap->da_previous = prevdirrem;
2810 		} else {
2811 			dap->da_state &= ~DIRCHG;
2812 			dap->da_pagedep = pagedep;
2813 		}
2814 		dirrem->dm_dirinum = pagedep->pd_ino;
2815 		add_to_worklist(&dirrem->dm_list);
2816 	}
2817 	/*
2818 	 * Link into its inodedep. Put it on the id_bufwait list if the inode
2819 	 * is not yet written. If it is written, do the post-inode write
2820 	 * processing to put it on the id_pendinghd list.
2821 	 */
2822 	if (inodedep_lookup(dp->i_fs, newinum, DEPALLOC, &inodedep) == 0 ||
2823 	    (inodedep->id_state & ALLCOMPLETE) == ALLCOMPLETE) {
2824 		dap->da_state |= COMPLETE;
2825 		LIST_INSERT_HEAD(&pagedep->pd_pendinghd, dap, da_pdlist);
2826 		WORKLIST_INSERT(&inodedep->id_pendinghd, &dap->da_list);
2827 	} else {
2828 		LIST_INSERT_HEAD(&pagedep->pd_diraddhd[DIRADDHASH(offset)],
2829 		    dap, da_pdlist);
2830 		WORKLIST_INSERT(&inodedep->id_bufwait, &dap->da_list);
2831 	}
2832 	FREE_LOCK(&lk);
2833 }
2834 
2835 /*
2836  * Called whenever the link count on an inode is changed.
2837  * It creates an inode dependency so that the new reference(s)
2838  * to the inode cannot be committed to disk until the updated
2839  * inode has been written.
2840  */
2841 void
2842 softdep_change_linkcnt(ip)
2843 	struct inode *ip;	/* the inode with the increased link count */
2844 {
2845 	struct inodedep *inodedep;
2846 
2847 	ACQUIRE_LOCK(&lk);
2848 	(void) inodedep_lookup(ip->i_fs, ip->i_number, DEPALLOC, &inodedep);
2849 	if (ip->i_nlink < ip->i_effnlink) {
2850 		FREE_LOCK(&lk);
2851 		panic("softdep_change_linkcnt: bad delta");
2852 	}
2853 	inodedep->id_nlinkdelta = ip->i_nlink - ip->i_effnlink;
2854 	FREE_LOCK(&lk);
2855 }
2856 
2857 /*
2858  * This workitem decrements the inode's link count.
2859  * If the link count reaches zero, the file is removed.
2860  */
2861 static void
2862 handle_workitem_remove(dirrem)
2863 	struct dirrem *dirrem;
2864 {
2865 	struct thread *td = curthread;	/* XXX */
2866 	struct inodedep *inodedep;
2867 	struct vnode *vp;
2868 	struct inode *ip;
2869 	ino_t oldinum;
2870 	int error;
2871 
2872 	if ((error = VFS_VGET(dirrem->dm_mnt, dirrem->dm_oldinum, &vp)) != 0) {
2873 		softdep_error("handle_workitem_remove: vget", error);
2874 		return;
2875 	}
2876 	ip = VTOI(vp);
2877 	ACQUIRE_LOCK(&lk);
2878 	if ((inodedep_lookup(ip->i_fs, dirrem->dm_oldinum, 0, &inodedep)) == 0){
2879 		FREE_LOCK(&lk);
2880 		panic("handle_workitem_remove: lost inodedep");
2881 	}
2882 	/*
2883 	 * Normal file deletion.
2884 	 */
2885 	if ((dirrem->dm_state & RMDIR) == 0) {
2886 		ip->i_nlink--;
2887 		ip->i_flag |= IN_CHANGE;
2888 		if (ip->i_nlink < ip->i_effnlink) {
2889 			FREE_LOCK(&lk);
2890 			panic("handle_workitem_remove: bad file delta");
2891 		}
2892 		inodedep->id_nlinkdelta = ip->i_nlink - ip->i_effnlink;
2893 		FREE_LOCK(&lk);
2894 		vput(vp);
2895 		num_dirrem -= 1;
2896 		WORKITEM_FREE(dirrem, D_DIRREM);
2897 		return;
2898 	}
2899 	/*
2900 	 * Directory deletion. Decrement reference count for both the
2901 	 * just deleted parent directory entry and the reference for ".".
2902 	 * Next truncate the directory to length zero. When the
2903 	 * truncation completes, arrange to have the reference count on
2904 	 * the parent decremented to account for the loss of "..".
2905 	 */
2906 	ip->i_nlink -= 2;
2907 	ip->i_flag |= IN_CHANGE;
2908 	if (ip->i_nlink < ip->i_effnlink) {
2909 		FREE_LOCK(&lk);
2910 		panic("handle_workitem_remove: bad dir delta");
2911 	}
2912 	inodedep->id_nlinkdelta = ip->i_nlink - ip->i_effnlink;
2913 	FREE_LOCK(&lk);
2914 	if ((error = UFS_TRUNCATE(vp, (off_t)0, 0, proc0.p_ucred, td)) != 0)
2915 		softdep_error("handle_workitem_remove: truncate", error);
2916 	/*
2917 	 * Rename a directory to a new parent. Since, we are both deleting
2918 	 * and creating a new directory entry, the link count on the new
2919 	 * directory should not change. Thus we skip the followup dirrem.
2920 	 */
2921 	if (dirrem->dm_state & DIRCHG) {
2922 		vput(vp);
2923 		num_dirrem -= 1;
2924 		WORKITEM_FREE(dirrem, D_DIRREM);
2925 		return;
2926 	}
2927 	/*
2928 	 * If the inodedep does not exist, then the zero'ed inode has
2929 	 * been written to disk. If the allocated inode has never been
2930 	 * written to disk, then the on-disk inode is zero'ed. In either
2931 	 * case we can remove the file immediately.
2932 	 */
2933 	ACQUIRE_LOCK(&lk);
2934 	dirrem->dm_state = 0;
2935 	oldinum = dirrem->dm_oldinum;
2936 	dirrem->dm_oldinum = dirrem->dm_dirinum;
2937 	if (inodedep_lookup(ip->i_fs, oldinum, 0, &inodedep) == 0 ||
2938 	    check_inode_unwritten(inodedep)) {
2939 		FREE_LOCK(&lk);
2940 		vput(vp);
2941 		handle_workitem_remove(dirrem);
2942 		return;
2943 	}
2944 	WORKLIST_INSERT(&inodedep->id_inowait, &dirrem->dm_list);
2945 	FREE_LOCK(&lk);
2946 	ip->i_flag |= IN_CHANGE;
2947 	ffs_update(vp, 0);
2948 	vput(vp);
2949 }
2950 
2951 /*
2952  * Inode de-allocation dependencies.
2953  *
2954  * When an inode's link count is reduced to zero, it can be de-allocated. We
2955  * found it convenient to postpone de-allocation until after the inode is
2956  * written to disk with its new link count (zero).  At this point, all of the
2957  * on-disk inode's block pointers are nullified and, with careful dependency
2958  * list ordering, all dependencies related to the inode will be satisfied and
2959  * the corresponding dependency structures de-allocated.  So, if/when the
2960  * inode is reused, there will be no mixing of old dependencies with new
2961  * ones.  This artificial dependency is set up by the block de-allocation
2962  * procedure above (softdep_setup_freeblocks) and completed by the
2963  * following procedure.
2964  */
2965 static void
2966 handle_workitem_freefile(freefile)
2967 	struct freefile *freefile;
2968 {
2969 	struct vnode vp;
2970 	struct inode tip;
2971 	struct inodedep *idp;
2972 	int error;
2973 
2974 #ifdef DEBUG
2975 	ACQUIRE_LOCK(&lk);
2976 	error = inodedep_lookup(freefile->fx_fs, freefile->fx_oldinum, 0, &idp);
2977 	FREE_LOCK(&lk);
2978 	if (error)
2979 		panic("handle_workitem_freefile: inodedep survived");
2980 #endif
2981 	tip.i_devvp = freefile->fx_devvp;
2982 	tip.i_dev = freefile->fx_devvp->v_rdev;
2983 	tip.i_fs = freefile->fx_fs;
2984 	vp.v_data = &tip;
2985 	if ((error = ffs_freefile(&vp, freefile->fx_oldinum, freefile->fx_mode)) != 0)
2986 		softdep_error("handle_workitem_freefile", error);
2987 	WORKITEM_FREE(freefile, D_FREEFILE);
2988 }
2989 
2990 /*
2991  * Helper function which unlinks marker element from work list and returns
2992  * the next element on the list.
2993  */
2994 static __inline struct worklist *
2995 markernext(struct worklist *marker)
2996 {
2997 	struct worklist *next;
2998 
2999 	next = LIST_NEXT(marker, wk_list);
3000 	LIST_REMOVE(marker, wk_list);
3001 	return next;
3002 }
3003 
3004 /*
3005  * Disk writes.
3006  *
3007  * The dependency structures constructed above are most actively used when file
3008  * system blocks are written to disk.  No constraints are placed on when a
3009  * block can be written, but unsatisfied update dependencies are made safe by
3010  * modifying (or replacing) the source memory for the duration of the disk
3011  * write.  When the disk write completes, the memory block is again brought
3012  * up-to-date.
3013  *
3014  * In-core inode structure reclamation.
3015  *
3016  * Because there are a finite number of "in-core" inode structures, they are
3017  * reused regularly.  By transferring all inode-related dependencies to the
3018  * in-memory inode block and indexing them separately (via "inodedep"s), we
3019  * can allow "in-core" inode structures to be reused at any time and avoid
3020  * any increase in contention.
3021  *
3022  * Called just before entering the device driver to initiate a new disk I/O.
3023  * The buffer must be locked, thus, no I/O completion operations can occur
3024  * while we are manipulating its associated dependencies.
3025  */
3026 static void
3027 softdep_disk_io_initiation(bp)
3028 	struct buf *bp;		/* structure describing disk write to occur */
3029 {
3030 	struct worklist *wk;
3031 	struct worklist marker;
3032 	struct indirdep *indirdep;
3033 
3034 	/*
3035 	 * We only care about write operations. There should never
3036 	 * be dependencies for reads.
3037 	 */
3038 	if (bp->b_flags & B_READ)
3039 		panic("softdep_disk_io_initiation: read");
3040 
3041 	marker.wk_type = D_LAST + 1;	/* Not a normal workitem */
3042 
3043 	/*
3044 	 * Do any necessary pre-I/O processing.
3045 	 */
3046 	for (wk = LIST_FIRST(&bp->b_dep); wk; wk = markernext(&marker)) {
3047 		LIST_INSERT_AFTER(wk, &marker, wk_list);
3048 
3049 		switch (wk->wk_type) {
3050 
3051 		case D_PAGEDEP:
3052 			initiate_write_filepage(WK_PAGEDEP(wk), bp);
3053 			continue;
3054 
3055 		case D_INODEDEP:
3056 			initiate_write_inodeblock(WK_INODEDEP(wk), bp);
3057 			continue;
3058 
3059 		case D_INDIRDEP:
3060 			indirdep = WK_INDIRDEP(wk);
3061 			if (indirdep->ir_state & GOINGAWAY)
3062 				panic("disk_io_initiation: indirdep gone");
3063 			/*
3064 			 * If there are no remaining dependencies, this
3065 			 * will be writing the real pointers, so the
3066 			 * dependency can be freed.
3067 			 */
3068 			if (LIST_FIRST(&indirdep->ir_deplisthd) == NULL) {
3069 				indirdep->ir_savebp->b_flags |= B_INVAL | B_NOCACHE;
3070 				brelse(indirdep->ir_savebp);
3071 				/* inline expand WORKLIST_REMOVE(wk); */
3072 				wk->wk_state &= ~ONWORKLIST;
3073 				LIST_REMOVE(wk, wk_list);
3074 				WORKITEM_FREE(indirdep, D_INDIRDEP);
3075 				continue;
3076 			}
3077 			/*
3078 			 * Replace up-to-date version with safe version.
3079 			 */
3080 			MALLOC(indirdep->ir_saveddata, caddr_t, bp->b_bcount,
3081 			    M_INDIRDEP, M_SOFTDEP_FLAGS);
3082 			ACQUIRE_LOCK(&lk);
3083 			indirdep->ir_state &= ~ATTACHED;
3084 			indirdep->ir_state |= UNDONE;
3085 			bcopy(bp->b_data, indirdep->ir_saveddata, bp->b_bcount);
3086 			bcopy(indirdep->ir_savebp->b_data, bp->b_data,
3087 			    bp->b_bcount);
3088 			FREE_LOCK(&lk);
3089 			continue;
3090 
3091 		case D_MKDIR:
3092 		case D_BMSAFEMAP:
3093 		case D_ALLOCDIRECT:
3094 		case D_ALLOCINDIR:
3095 			continue;
3096 
3097 		default:
3098 			panic("handle_disk_io_initiation: Unexpected type %s",
3099 			    TYPENAME(wk->wk_type));
3100 			/* NOTREACHED */
3101 		}
3102 	}
3103 }
3104 
3105 /*
3106  * Called from within the procedure above to deal with unsatisfied
3107  * allocation dependencies in a directory. The buffer must be locked,
3108  * thus, no I/O completion operations can occur while we are
3109  * manipulating its associated dependencies.
3110  */
3111 static void
3112 initiate_write_filepage(pagedep, bp)
3113 	struct pagedep *pagedep;
3114 	struct buf *bp;
3115 {
3116 	struct diradd *dap;
3117 	struct direct *ep;
3118 	int i;
3119 
3120 	if (pagedep->pd_state & IOSTARTED) {
3121 		/*
3122 		 * This can only happen if there is a driver that does not
3123 		 * understand chaining. Here biodone will reissue the call
3124 		 * to strategy for the incomplete buffers.
3125 		 */
3126 		printf("initiate_write_filepage: already started\n");
3127 		return;
3128 	}
3129 	pagedep->pd_state |= IOSTARTED;
3130 	ACQUIRE_LOCK(&lk);
3131 	for (i = 0; i < DAHASHSZ; i++) {
3132 		LIST_FOREACH(dap, &pagedep->pd_diraddhd[i], da_pdlist) {
3133 			ep = (struct direct *)
3134 			    ((char *)bp->b_data + dap->da_offset);
3135 			if (ep->d_ino != dap->da_newinum) {
3136 				FREE_LOCK(&lk);
3137 				panic("%s: dir inum %d != new %"PRId64,
3138 				    "initiate_write_filepage",
3139 				    ep->d_ino, dap->da_newinum);
3140 			}
3141 			if (dap->da_state & DIRCHG)
3142 				ep->d_ino = dap->da_previous->dm_oldinum;
3143 			else
3144 				ep->d_ino = 0;
3145 			dap->da_state &= ~ATTACHED;
3146 			dap->da_state |= UNDONE;
3147 		}
3148 	}
3149 	FREE_LOCK(&lk);
3150 }
3151 
3152 /*
3153  * Called from within the procedure above to deal with unsatisfied
3154  * allocation dependencies in an inodeblock. The buffer must be
3155  * locked, thus, no I/O completion operations can occur while we
3156  * are manipulating its associated dependencies.
3157  */
3158 static void
3159 initiate_write_inodeblock(inodedep, bp)
3160 	struct inodedep *inodedep;
3161 	struct buf *bp;			/* The inode block */
3162 {
3163 	struct allocdirect *adp, *lastadp;
3164 	struct dinode *dp;
3165 	struct dinode *sip;
3166 	struct fs *fs;
3167 	ufs_lbn_t prevlbn = 0;
3168 	int i, deplist;
3169 
3170 	if (inodedep->id_state & IOSTARTED)
3171 		panic("initiate_write_inodeblock: already started");
3172 	inodedep->id_state |= IOSTARTED;
3173 	fs = inodedep->id_fs;
3174 	dp = (struct dinode *)bp->b_data +
3175 	    ino_to_fsbo(fs, inodedep->id_ino);
3176 	/*
3177 	 * If the bitmap is not yet written, then the allocated
3178 	 * inode cannot be written to disk.
3179 	 */
3180 	if ((inodedep->id_state & DEPCOMPLETE) == 0) {
3181 		if (inodedep->id_savedino != NULL)
3182 			panic("initiate_write_inodeblock: already doing I/O");
3183 		MALLOC(sip, struct dinode *,
3184 		    sizeof(struct dinode), M_INODEDEP, M_SOFTDEP_FLAGS);
3185 		inodedep->id_savedino = sip;
3186 		*inodedep->id_savedino = *dp;
3187 		bzero((caddr_t)dp, sizeof(struct dinode));
3188 		dp->di_gen = inodedep->id_savedino->di_gen;
3189 		return;
3190 	}
3191 	/*
3192 	 * If no dependencies, then there is nothing to roll back.
3193 	 */
3194 	inodedep->id_savedsize = dp->di_size;
3195 	if (TAILQ_FIRST(&inodedep->id_inoupdt) == NULL)
3196 		return;
3197 	/*
3198 	 * Set the dependencies to busy.
3199 	 */
3200 	ACQUIRE_LOCK(&lk);
3201 	for (deplist = 0, adp = TAILQ_FIRST(&inodedep->id_inoupdt); adp;
3202 	     adp = TAILQ_NEXT(adp, ad_next)) {
3203 #ifdef DIAGNOSTIC
3204 		if (deplist != 0 && prevlbn >= adp->ad_lbn) {
3205 			FREE_LOCK(&lk);
3206 			panic("softdep_write_inodeblock: lbn order");
3207 		}
3208 		prevlbn = adp->ad_lbn;
3209 		if (adp->ad_lbn < NDADDR &&
3210 		    dp->di_db[adp->ad_lbn] != adp->ad_newblkno) {
3211 			FREE_LOCK(&lk);
3212 			panic("%s: direct pointer #%ld mismatch %d != %d",
3213 			    "softdep_write_inodeblock", adp->ad_lbn,
3214 			    dp->di_db[adp->ad_lbn], adp->ad_newblkno);
3215 		}
3216 		if (adp->ad_lbn >= NDADDR &&
3217 		    dp->di_ib[adp->ad_lbn - NDADDR] != adp->ad_newblkno) {
3218 			FREE_LOCK(&lk);
3219 			panic("%s: indirect pointer #%ld mismatch %d != %d",
3220 			    "softdep_write_inodeblock", adp->ad_lbn - NDADDR,
3221 			    dp->di_ib[adp->ad_lbn - NDADDR], adp->ad_newblkno);
3222 		}
3223 		deplist |= 1 << adp->ad_lbn;
3224 		if ((adp->ad_state & ATTACHED) == 0) {
3225 			FREE_LOCK(&lk);
3226 			panic("softdep_write_inodeblock: Unknown state 0x%x",
3227 			    adp->ad_state);
3228 		}
3229 #endif /* DIAGNOSTIC */
3230 		adp->ad_state &= ~ATTACHED;
3231 		adp->ad_state |= UNDONE;
3232 	}
3233 	/*
3234 	 * The on-disk inode cannot claim to be any larger than the last
3235 	 * fragment that has been written. Otherwise, the on-disk inode
3236 	 * might have fragments that were not the last block in the file
3237 	 * which would corrupt the filesystem.
3238 	 */
3239 	for (lastadp = NULL, adp = TAILQ_FIRST(&inodedep->id_inoupdt); adp;
3240 	     lastadp = adp, adp = TAILQ_NEXT(adp, ad_next)) {
3241 		if (adp->ad_lbn >= NDADDR)
3242 			break;
3243 		dp->di_db[adp->ad_lbn] = adp->ad_oldblkno;
3244 		/* keep going until hitting a rollback to a frag */
3245 		if (adp->ad_oldsize == 0 || adp->ad_oldsize == fs->fs_bsize)
3246 			continue;
3247 		dp->di_size = fs->fs_bsize * adp->ad_lbn + adp->ad_oldsize;
3248 		for (i = adp->ad_lbn + 1; i < NDADDR; i++) {
3249 #ifdef DIAGNOSTIC
3250 			if (dp->di_db[i] != 0 && (deplist & (1 << i)) == 0) {
3251 				FREE_LOCK(&lk);
3252 				panic("softdep_write_inodeblock: lost dep1");
3253 			}
3254 #endif /* DIAGNOSTIC */
3255 			dp->di_db[i] = 0;
3256 		}
3257 		for (i = 0; i < NIADDR; i++) {
3258 #ifdef DIAGNOSTIC
3259 			if (dp->di_ib[i] != 0 &&
3260 			    (deplist & ((1 << NDADDR) << i)) == 0) {
3261 				FREE_LOCK(&lk);
3262 				panic("softdep_write_inodeblock: lost dep2");
3263 			}
3264 #endif /* DIAGNOSTIC */
3265 			dp->di_ib[i] = 0;
3266 		}
3267 		FREE_LOCK(&lk);
3268 		return;
3269 	}
3270 	/*
3271 	 * If we have zero'ed out the last allocated block of the file,
3272 	 * roll back the size to the last currently allocated block.
3273 	 * We know that this last allocated block is a full-sized as
3274 	 * we already checked for fragments in the loop above.
3275 	 */
3276 	if (lastadp != NULL &&
3277 	    dp->di_size <= (lastadp->ad_lbn + 1) * fs->fs_bsize) {
3278 		for (i = lastadp->ad_lbn; i >= 0; i--)
3279 			if (dp->di_db[i] != 0)
3280 				break;
3281 		dp->di_size = (i + 1) * fs->fs_bsize;
3282 	}
3283 	/*
3284 	 * The only dependencies are for indirect blocks.
3285 	 *
3286 	 * The file size for indirect block additions is not guaranteed.
3287 	 * Such a guarantee would be non-trivial to achieve. The conventional
3288 	 * synchronous write implementation also does not make this guarantee.
3289 	 * Fsck should catch and fix discrepancies. Arguably, the file size
3290 	 * can be over-estimated without destroying integrity when the file
3291 	 * moves into the indirect blocks (i.e., is large). If we want to
3292 	 * postpone fsck, we are stuck with this argument.
3293 	 */
3294 	for (; adp; adp = TAILQ_NEXT(adp, ad_next))
3295 		dp->di_ib[adp->ad_lbn - NDADDR] = 0;
3296 	FREE_LOCK(&lk);
3297 }
3298 
3299 /*
3300  * This routine is called during the completion interrupt
3301  * service routine for a disk write (from the procedure called
3302  * by the device driver to inform the filesystem caches of
3303  * a request completion).  It should be called early in this
3304  * procedure, before the block is made available to other
3305  * processes or other routines are called.
3306  */
3307 static void
3308 softdep_disk_write_complete(bp)
3309 	struct buf *bp;		/* describes the completed disk write */
3310 {
3311 	struct worklist *wk;
3312 	struct workhead reattach;
3313 	struct newblk *newblk;
3314 	struct allocindir *aip;
3315 	struct allocdirect *adp;
3316 	struct indirdep *indirdep;
3317 	struct inodedep *inodedep;
3318 	struct bmsafemap *bmsafemap;
3319 
3320 #ifdef DEBUG
3321 	if (lk.lkt_held != NOHOLDER)
3322 		panic("softdep_disk_write_complete: lock is held");
3323 	lk.lkt_held = SPECIAL_FLAG;
3324 #endif
3325 	LIST_INIT(&reattach);
3326 	while ((wk = LIST_FIRST(&bp->b_dep)) != NULL) {
3327 		WORKLIST_REMOVE(wk);
3328 		switch (wk->wk_type) {
3329 
3330 		case D_PAGEDEP:
3331 			if (handle_written_filepage(WK_PAGEDEP(wk), bp))
3332 				WORKLIST_INSERT(&reattach, wk);
3333 			continue;
3334 
3335 		case D_INODEDEP:
3336 			if (handle_written_inodeblock(WK_INODEDEP(wk), bp))
3337 				WORKLIST_INSERT(&reattach, wk);
3338 			continue;
3339 
3340 		case D_BMSAFEMAP:
3341 			bmsafemap = WK_BMSAFEMAP(wk);
3342 			while ((newblk = LIST_FIRST(&bmsafemap->sm_newblkhd))) {
3343 				newblk->nb_state |= DEPCOMPLETE;
3344 				newblk->nb_bmsafemap = NULL;
3345 				LIST_REMOVE(newblk, nb_deps);
3346 			}
3347 			while ((adp =
3348 			   LIST_FIRST(&bmsafemap->sm_allocdirecthd))) {
3349 				adp->ad_state |= DEPCOMPLETE;
3350 				adp->ad_buf = NULL;
3351 				LIST_REMOVE(adp, ad_deps);
3352 				handle_allocdirect_partdone(adp);
3353 			}
3354 			while ((aip =
3355 			    LIST_FIRST(&bmsafemap->sm_allocindirhd))) {
3356 				aip->ai_state |= DEPCOMPLETE;
3357 				aip->ai_buf = NULL;
3358 				LIST_REMOVE(aip, ai_deps);
3359 				handle_allocindir_partdone(aip);
3360 			}
3361 			while ((inodedep =
3362 			     LIST_FIRST(&bmsafemap->sm_inodedephd)) != NULL) {
3363 				inodedep->id_state |= DEPCOMPLETE;
3364 				LIST_REMOVE(inodedep, id_deps);
3365 				inodedep->id_buf = NULL;
3366 			}
3367 			WORKITEM_FREE(bmsafemap, D_BMSAFEMAP);
3368 			continue;
3369 
3370 		case D_MKDIR:
3371 			handle_written_mkdir(WK_MKDIR(wk), MKDIR_BODY);
3372 			continue;
3373 
3374 		case D_ALLOCDIRECT:
3375 			adp = WK_ALLOCDIRECT(wk);
3376 			adp->ad_state |= COMPLETE;
3377 			handle_allocdirect_partdone(adp);
3378 			continue;
3379 
3380 		case D_ALLOCINDIR:
3381 			aip = WK_ALLOCINDIR(wk);
3382 			aip->ai_state |= COMPLETE;
3383 			handle_allocindir_partdone(aip);
3384 			continue;
3385 
3386 		case D_INDIRDEP:
3387 			indirdep = WK_INDIRDEP(wk);
3388 			if (indirdep->ir_state & GOINGAWAY) {
3389 				lk.lkt_held = NOHOLDER;
3390 				panic("disk_write_complete: indirdep gone");
3391 			}
3392 			bcopy(indirdep->ir_saveddata, bp->b_data, bp->b_bcount);
3393 			FREE(indirdep->ir_saveddata, M_INDIRDEP);
3394 			indirdep->ir_saveddata = 0;
3395 			indirdep->ir_state &= ~UNDONE;
3396 			indirdep->ir_state |= ATTACHED;
3397 			while ((aip = LIST_FIRST(&indirdep->ir_donehd)) != 0) {
3398 				handle_allocindir_partdone(aip);
3399 				if (aip == LIST_FIRST(&indirdep->ir_donehd)) {
3400 					lk.lkt_held = NOHOLDER;
3401 					panic("disk_write_complete: not gone");
3402 				}
3403 			}
3404 			WORKLIST_INSERT(&reattach, wk);
3405 			if ((bp->b_flags & B_DELWRI) == 0)
3406 				stat_indir_blk_ptrs++;
3407 			bdirty(bp);
3408 			continue;
3409 
3410 		default:
3411 			lk.lkt_held = NOHOLDER;
3412 			panic("handle_disk_write_complete: Unknown type %s",
3413 			    TYPENAME(wk->wk_type));
3414 			/* NOTREACHED */
3415 		}
3416 	}
3417 	/*
3418 	 * Reattach any requests that must be redone.
3419 	 */
3420 	while ((wk = LIST_FIRST(&reattach)) != NULL) {
3421 		WORKLIST_REMOVE(wk);
3422 		WORKLIST_INSERT(&bp->b_dep, wk);
3423 	}
3424 #ifdef DEBUG
3425 	if (lk.lkt_held != SPECIAL_FLAG)
3426 		panic("softdep_disk_write_complete: lock lost");
3427 	lk.lkt_held = NOHOLDER;
3428 #endif
3429 }
3430 
3431 /*
3432  * Called from within softdep_disk_write_complete above. Note that
3433  * this routine is always called from interrupt level with further
3434  * splbio interrupts blocked.
3435  */
3436 static void
3437 handle_allocdirect_partdone(adp)
3438 	struct allocdirect *adp;	/* the completed allocdirect */
3439 {
3440 	struct allocdirect *listadp;
3441 	struct inodedep *inodedep;
3442 	long bsize;
3443 
3444 	if ((adp->ad_state & ALLCOMPLETE) != ALLCOMPLETE)
3445 		return;
3446 	if (adp->ad_buf != NULL) {
3447 		lk.lkt_held = NOHOLDER;
3448 		panic("handle_allocdirect_partdone: dangling dep");
3449 	}
3450 	/*
3451 	 * The on-disk inode cannot claim to be any larger than the last
3452 	 * fragment that has been written. Otherwise, the on-disk inode
3453 	 * might have fragments that were not the last block in the file
3454 	 * which would corrupt the filesystem. Thus, we cannot free any
3455 	 * allocdirects after one whose ad_oldblkno claims a fragment as
3456 	 * these blocks must be rolled back to zero before writing the inode.
3457 	 * We check the currently active set of allocdirects in id_inoupdt.
3458 	 */
3459 	inodedep = adp->ad_inodedep;
3460 	bsize = inodedep->id_fs->fs_bsize;
3461 	TAILQ_FOREACH(listadp, &inodedep->id_inoupdt, ad_next) {
3462 		/* found our block */
3463 		if (listadp == adp)
3464 			break;
3465 		/* continue if ad_oldlbn is not a fragment */
3466 		if (listadp->ad_oldsize == 0 ||
3467 		    listadp->ad_oldsize == bsize)
3468 			continue;
3469 		/* hit a fragment */
3470 		return;
3471 	}
3472 	/*
3473 	 * If we have reached the end of the current list without
3474 	 * finding the just finished dependency, then it must be
3475 	 * on the future dependency list. Future dependencies cannot
3476 	 * be freed until they are moved to the current list.
3477 	 */
3478 	if (listadp == NULL) {
3479 #ifdef DEBUG
3480 		TAILQ_FOREACH(listadp, &inodedep->id_newinoupdt, ad_next)
3481 			/* found our block */
3482 			if (listadp == adp)
3483 				break;
3484 		if (listadp == NULL) {
3485 			lk.lkt_held = NOHOLDER;
3486 			panic("handle_allocdirect_partdone: lost dep");
3487 		}
3488 #endif /* DEBUG */
3489 		return;
3490 	}
3491 	/*
3492 	 * If we have found the just finished dependency, then free
3493 	 * it along with anything that follows it that is complete.
3494 	 */
3495 	for (; adp; adp = listadp) {
3496 		listadp = TAILQ_NEXT(adp, ad_next);
3497 		if ((adp->ad_state & ALLCOMPLETE) != ALLCOMPLETE)
3498 			return;
3499 		free_allocdirect(&inodedep->id_inoupdt, adp, 1);
3500 	}
3501 }
3502 
3503 /*
3504  * Called from within softdep_disk_write_complete above. Note that
3505  * this routine is always called from interrupt level with further
3506  * splbio interrupts blocked.
3507  */
3508 static void
3509 handle_allocindir_partdone(aip)
3510 	struct allocindir *aip;		/* the completed allocindir */
3511 {
3512 	struct indirdep *indirdep;
3513 
3514 	if ((aip->ai_state & ALLCOMPLETE) != ALLCOMPLETE)
3515 		return;
3516 	if (aip->ai_buf != NULL) {
3517 		lk.lkt_held = NOHOLDER;
3518 		panic("handle_allocindir_partdone: dangling dependency");
3519 	}
3520 	indirdep = aip->ai_indirdep;
3521 	if (indirdep->ir_state & UNDONE) {
3522 		LIST_REMOVE(aip, ai_next);
3523 		LIST_INSERT_HEAD(&indirdep->ir_donehd, aip, ai_next);
3524 		return;
3525 	}
3526 	((ufs_daddr_t *)indirdep->ir_savebp->b_data)[aip->ai_offset] =
3527 	    aip->ai_newblkno;
3528 	LIST_REMOVE(aip, ai_next);
3529 	if (aip->ai_freefrag != NULL)
3530 		add_to_worklist(&aip->ai_freefrag->ff_list);
3531 	WORKITEM_FREE(aip, D_ALLOCINDIR);
3532 }
3533 
3534 /*
3535  * Called from within softdep_disk_write_complete above to restore
3536  * in-memory inode block contents to their most up-to-date state. Note
3537  * that this routine is always called from interrupt level with further
3538  * splbio interrupts blocked.
3539  */
3540 static int
3541 handle_written_inodeblock(inodedep, bp)
3542 	struct inodedep *inodedep;
3543 	struct buf *bp;		/* buffer containing the inode block */
3544 {
3545 	struct worklist *wk, *filefree;
3546 	struct allocdirect *adp, *nextadp;
3547 	struct dinode *dp;
3548 	int hadchanges;
3549 
3550 	if ((inodedep->id_state & IOSTARTED) == 0) {
3551 		lk.lkt_held = NOHOLDER;
3552 		panic("handle_written_inodeblock: not started");
3553 	}
3554 	inodedep->id_state &= ~IOSTARTED;
3555 	dp = (struct dinode *)bp->b_data +
3556 	    ino_to_fsbo(inodedep->id_fs, inodedep->id_ino);
3557 	/*
3558 	 * If we had to rollback the inode allocation because of
3559 	 * bitmaps being incomplete, then simply restore it.
3560 	 * Keep the block dirty so that it will not be reclaimed until
3561 	 * all associated dependencies have been cleared and the
3562 	 * corresponding updates written to disk.
3563 	 */
3564 	if (inodedep->id_savedino != NULL) {
3565 		*dp = *inodedep->id_savedino;
3566 		FREE(inodedep->id_savedino, M_INODEDEP);
3567 		inodedep->id_savedino = NULL;
3568 		if ((bp->b_flags & B_DELWRI) == 0)
3569 			stat_inode_bitmap++;
3570 		bdirty(bp);
3571 		return (1);
3572 	}
3573 	inodedep->id_state |= COMPLETE;
3574 	/*
3575 	 * Roll forward anything that had to be rolled back before
3576 	 * the inode could be updated.
3577 	 */
3578 	hadchanges = 0;
3579 	for (adp = TAILQ_FIRST(&inodedep->id_inoupdt); adp; adp = nextadp) {
3580 		nextadp = TAILQ_NEXT(adp, ad_next);
3581 		if (adp->ad_state & ATTACHED) {
3582 			lk.lkt_held = NOHOLDER;
3583 			panic("handle_written_inodeblock: new entry");
3584 		}
3585 		if (adp->ad_lbn < NDADDR) {
3586 			if (dp->di_db[adp->ad_lbn] != adp->ad_oldblkno) {
3587 				lk.lkt_held = NOHOLDER;
3588 				panic("%s: %s #%ld mismatch %d != %d",
3589 				    "handle_written_inodeblock",
3590 				    "direct pointer", adp->ad_lbn,
3591 				    dp->di_db[adp->ad_lbn], adp->ad_oldblkno);
3592 			}
3593 			dp->di_db[adp->ad_lbn] = adp->ad_newblkno;
3594 		} else {
3595 			if (dp->di_ib[adp->ad_lbn - NDADDR] != 0) {
3596 				lk.lkt_held = NOHOLDER;
3597 				panic("%s: %s #%ld allocated as %d",
3598 				    "handle_written_inodeblock",
3599 				    "indirect pointer", adp->ad_lbn - NDADDR,
3600 				    dp->di_ib[adp->ad_lbn - NDADDR]);
3601 			}
3602 			dp->di_ib[adp->ad_lbn - NDADDR] = adp->ad_newblkno;
3603 		}
3604 		adp->ad_state &= ~UNDONE;
3605 		adp->ad_state |= ATTACHED;
3606 		hadchanges = 1;
3607 	}
3608 	if (hadchanges && (bp->b_flags & B_DELWRI) == 0)
3609 		stat_direct_blk_ptrs++;
3610 	/*
3611 	 * Reset the file size to its most up-to-date value.
3612 	 */
3613 	if (inodedep->id_savedsize == -1) {
3614 		lk.lkt_held = NOHOLDER;
3615 		panic("handle_written_inodeblock: bad size");
3616 	}
3617 	if (dp->di_size != inodedep->id_savedsize) {
3618 		dp->di_size = inodedep->id_savedsize;
3619 		hadchanges = 1;
3620 	}
3621 	inodedep->id_savedsize = -1;
3622 	/*
3623 	 * If there were any rollbacks in the inode block, then it must be
3624 	 * marked dirty so that its will eventually get written back in
3625 	 * its correct form.
3626 	 */
3627 	if (hadchanges)
3628 		bdirty(bp);
3629 	/*
3630 	 * Process any allocdirects that completed during the update.
3631 	 */
3632 	if ((adp = TAILQ_FIRST(&inodedep->id_inoupdt)) != NULL)
3633 		handle_allocdirect_partdone(adp);
3634 	/*
3635 	 * Process deallocations that were held pending until the
3636 	 * inode had been written to disk. Freeing of the inode
3637 	 * is delayed until after all blocks have been freed to
3638 	 * avoid creation of new <vfsid, inum, lbn> triples
3639 	 * before the old ones have been deleted.
3640 	 */
3641 	filefree = NULL;
3642 	while ((wk = LIST_FIRST(&inodedep->id_bufwait)) != NULL) {
3643 		WORKLIST_REMOVE(wk);
3644 		switch (wk->wk_type) {
3645 
3646 		case D_FREEFILE:
3647 			/*
3648 			 * We defer adding filefree to the worklist until
3649 			 * all other additions have been made to ensure
3650 			 * that it will be done after all the old blocks
3651 			 * have been freed.
3652 			 */
3653 			if (filefree != NULL) {
3654 				lk.lkt_held = NOHOLDER;
3655 				panic("handle_written_inodeblock: filefree");
3656 			}
3657 			filefree = wk;
3658 			continue;
3659 
3660 		case D_MKDIR:
3661 			handle_written_mkdir(WK_MKDIR(wk), MKDIR_PARENT);
3662 			continue;
3663 
3664 		case D_DIRADD:
3665 			diradd_inode_written(WK_DIRADD(wk), inodedep);
3666 			continue;
3667 
3668 		case D_FREEBLKS:
3669 			wk->wk_state |= COMPLETE;
3670 			if ((wk->wk_state  & ALLCOMPLETE) != ALLCOMPLETE)
3671 				continue;
3672 			/* -- fall through -- */
3673 		case D_FREEFRAG:
3674 		case D_DIRREM:
3675 			add_to_worklist(wk);
3676 			continue;
3677 
3678 		default:
3679 			lk.lkt_held = NOHOLDER;
3680 			panic("handle_written_inodeblock: Unknown type %s",
3681 			    TYPENAME(wk->wk_type));
3682 			/* NOTREACHED */
3683 		}
3684 	}
3685 	if (filefree != NULL) {
3686 		if (free_inodedep(inodedep) == 0) {
3687 			lk.lkt_held = NOHOLDER;
3688 			panic("handle_written_inodeblock: live inodedep");
3689 		}
3690 		add_to_worklist(filefree);
3691 		return (0);
3692 	}
3693 
3694 	/*
3695 	 * If no outstanding dependencies, free it.
3696 	 */
3697 	if (free_inodedep(inodedep) || TAILQ_FIRST(&inodedep->id_inoupdt) == 0)
3698 		return (0);
3699 	return (hadchanges);
3700 }
3701 
3702 /*
3703  * Process a diradd entry after its dependent inode has been written.
3704  * This routine must be called with splbio interrupts blocked.
3705  */
3706 static void
3707 diradd_inode_written(dap, inodedep)
3708 	struct diradd *dap;
3709 	struct inodedep *inodedep;
3710 {
3711 	struct pagedep *pagedep;
3712 
3713 	dap->da_state |= COMPLETE;
3714 	if ((dap->da_state & ALLCOMPLETE) == ALLCOMPLETE) {
3715 		if (dap->da_state & DIRCHG)
3716 			pagedep = dap->da_previous->dm_pagedep;
3717 		else
3718 			pagedep = dap->da_pagedep;
3719 		LIST_REMOVE(dap, da_pdlist);
3720 		LIST_INSERT_HEAD(&pagedep->pd_pendinghd, dap, da_pdlist);
3721 	}
3722 	WORKLIST_INSERT(&inodedep->id_pendinghd, &dap->da_list);
3723 }
3724 
3725 /*
3726  * Handle the completion of a mkdir dependency.
3727  */
3728 static void
3729 handle_written_mkdir(mkdir, type)
3730 	struct mkdir *mkdir;
3731 	int type;
3732 {
3733 	struct diradd *dap;
3734 	struct pagedep *pagedep;
3735 
3736 	if (mkdir->md_state != type) {
3737 		lk.lkt_held = NOHOLDER;
3738 		panic("handle_written_mkdir: bad type");
3739 	}
3740 	dap = mkdir->md_diradd;
3741 	dap->da_state &= ~type;
3742 	if ((dap->da_state & (MKDIR_PARENT | MKDIR_BODY)) == 0)
3743 		dap->da_state |= DEPCOMPLETE;
3744 	if ((dap->da_state & ALLCOMPLETE) == ALLCOMPLETE) {
3745 		if (dap->da_state & DIRCHG)
3746 			pagedep = dap->da_previous->dm_pagedep;
3747 		else
3748 			pagedep = dap->da_pagedep;
3749 		LIST_REMOVE(dap, da_pdlist);
3750 		LIST_INSERT_HEAD(&pagedep->pd_pendinghd, dap, da_pdlist);
3751 	}
3752 	LIST_REMOVE(mkdir, md_mkdirs);
3753 	WORKITEM_FREE(mkdir, D_MKDIR);
3754 }
3755 
3756 /*
3757  * Called from within softdep_disk_write_complete above.
3758  * A write operation was just completed. Removed inodes can
3759  * now be freed and associated block pointers may be committed.
3760  * Note that this routine is always called from interrupt level
3761  * with further splbio interrupts blocked.
3762  */
3763 static int
3764 handle_written_filepage(pagedep, bp)
3765 	struct pagedep *pagedep;
3766 	struct buf *bp;		/* buffer containing the written page */
3767 {
3768 	struct dirrem *dirrem;
3769 	struct diradd *dap, *nextdap;
3770 	struct direct *ep;
3771 	int i, chgs;
3772 
3773 	if ((pagedep->pd_state & IOSTARTED) == 0) {
3774 		lk.lkt_held = NOHOLDER;
3775 		panic("handle_written_filepage: not started");
3776 	}
3777 	pagedep->pd_state &= ~IOSTARTED;
3778 	/*
3779 	 * Process any directory removals that have been committed.
3780 	 */
3781 	while ((dirrem = LIST_FIRST(&pagedep->pd_dirremhd)) != NULL) {
3782 		LIST_REMOVE(dirrem, dm_next);
3783 		dirrem->dm_dirinum = pagedep->pd_ino;
3784 		add_to_worklist(&dirrem->dm_list);
3785 	}
3786 	/*
3787 	 * Free any directory additions that have been committed.
3788 	 */
3789 	while ((dap = LIST_FIRST(&pagedep->pd_pendinghd)) != NULL)
3790 		free_diradd(dap);
3791 	/*
3792 	 * Uncommitted directory entries must be restored.
3793 	 */
3794 	for (chgs = 0, i = 0; i < DAHASHSZ; i++) {
3795 		for (dap = LIST_FIRST(&pagedep->pd_diraddhd[i]); dap;
3796 		     dap = nextdap) {
3797 			nextdap = LIST_NEXT(dap, da_pdlist);
3798 			if (dap->da_state & ATTACHED) {
3799 				lk.lkt_held = NOHOLDER;
3800 				panic("handle_written_filepage: attached");
3801 			}
3802 			ep = (struct direct *)
3803 			    ((char *)bp->b_data + dap->da_offset);
3804 			ep->d_ino = dap->da_newinum;
3805 			dap->da_state &= ~UNDONE;
3806 			dap->da_state |= ATTACHED;
3807 			chgs = 1;
3808 			/*
3809 			 * If the inode referenced by the directory has
3810 			 * been written out, then the dependency can be
3811 			 * moved to the pending list.
3812 			 */
3813 			if ((dap->da_state & ALLCOMPLETE) == ALLCOMPLETE) {
3814 				LIST_REMOVE(dap, da_pdlist);
3815 				LIST_INSERT_HEAD(&pagedep->pd_pendinghd, dap,
3816 				    da_pdlist);
3817 			}
3818 		}
3819 	}
3820 	/*
3821 	 * If there were any rollbacks in the directory, then it must be
3822 	 * marked dirty so that its will eventually get written back in
3823 	 * its correct form.
3824 	 */
3825 	if (chgs) {
3826 		if ((bp->b_flags & B_DELWRI) == 0)
3827 			stat_dir_entry++;
3828 		bdirty(bp);
3829 	}
3830 	/*
3831 	 * If no dependencies remain, the pagedep will be freed.
3832 	 * Otherwise it will remain to update the page before it
3833 	 * is written back to disk.
3834 	 */
3835 	if (LIST_FIRST(&pagedep->pd_pendinghd) == 0) {
3836 		for (i = 0; i < DAHASHSZ; i++)
3837 			if (LIST_FIRST(&pagedep->pd_diraddhd[i]) != NULL)
3838 				break;
3839 		if (i == DAHASHSZ) {
3840 			LIST_REMOVE(pagedep, pd_hash);
3841 			WORKITEM_FREE(pagedep, D_PAGEDEP);
3842 			return (0);
3843 		}
3844 	}
3845 	return (1);
3846 }
3847 
3848 /*
3849  * Writing back in-core inode structures.
3850  *
3851  * The filesystem only accesses an inode's contents when it occupies an
3852  * "in-core" inode structure.  These "in-core" structures are separate from
3853  * the page frames used to cache inode blocks.  Only the latter are
3854  * transferred to/from the disk.  So, when the updated contents of the
3855  * "in-core" inode structure are copied to the corresponding in-memory inode
3856  * block, the dependencies are also transferred.  The following procedure is
3857  * called when copying a dirty "in-core" inode to a cached inode block.
3858  */
3859 
3860 /*
3861  * Called when an inode is loaded from disk. If the effective link count
3862  * differed from the actual link count when it was last flushed, then we
3863  * need to ensure that the correct effective link count is put back.
3864  */
3865 void
3866 softdep_load_inodeblock(ip)
3867 	struct inode *ip;	/* the "in_core" copy of the inode */
3868 {
3869 	struct inodedep *inodedep;
3870 
3871 	/*
3872 	 * Check for alternate nlink count.
3873 	 */
3874 	ip->i_effnlink = ip->i_nlink;
3875 	ACQUIRE_LOCK(&lk);
3876 	if (inodedep_lookup(ip->i_fs, ip->i_number, 0, &inodedep) == 0) {
3877 		FREE_LOCK(&lk);
3878 		return;
3879 	}
3880 	ip->i_effnlink -= inodedep->id_nlinkdelta;
3881 	FREE_LOCK(&lk);
3882 }
3883 
3884 /*
3885  * This routine is called just before the "in-core" inode
3886  * information is to be copied to the in-memory inode block.
3887  * Recall that an inode block contains several inodes. If
3888  * the force flag is set, then the dependencies will be
3889  * cleared so that the update can always be made. Note that
3890  * the buffer is locked when this routine is called, so we
3891  * will never be in the middle of writing the inode block
3892  * to disk.
3893  */
3894 void
3895 softdep_update_inodeblock(ip, bp, waitfor)
3896 	struct inode *ip;	/* the "in_core" copy of the inode */
3897 	struct buf *bp;		/* the buffer containing the inode block */
3898 	int waitfor;		/* nonzero => update must be allowed */
3899 {
3900 	struct inodedep *inodedep;
3901 	struct worklist *wk;
3902 	int error, gotit;
3903 
3904 	/*
3905 	 * If the effective link count is not equal to the actual link
3906 	 * count, then we must track the difference in an inodedep while
3907 	 * the inode is (potentially) tossed out of the cache. Otherwise,
3908 	 * if there is no existing inodedep, then there are no dependencies
3909 	 * to track.
3910 	 */
3911 	ACQUIRE_LOCK(&lk);
3912 	if (inodedep_lookup(ip->i_fs, ip->i_number, 0, &inodedep) == 0) {
3913 		FREE_LOCK(&lk);
3914 		if (ip->i_effnlink != ip->i_nlink)
3915 			panic("softdep_update_inodeblock: bad link count");
3916 		return;
3917 	}
3918 	if (inodedep->id_nlinkdelta != ip->i_nlink - ip->i_effnlink) {
3919 		FREE_LOCK(&lk);
3920 		panic("softdep_update_inodeblock: bad delta");
3921 	}
3922 	/*
3923 	 * Changes have been initiated. Anything depending on these
3924 	 * changes cannot occur until this inode has been written.
3925 	 */
3926 	inodedep->id_state &= ~COMPLETE;
3927 	if ((inodedep->id_state & ONWORKLIST) == 0)
3928 		WORKLIST_INSERT(&bp->b_dep, &inodedep->id_list);
3929 	/*
3930 	 * Any new dependencies associated with the incore inode must
3931 	 * now be moved to the list associated with the buffer holding
3932 	 * the in-memory copy of the inode. Once merged process any
3933 	 * allocdirects that are completed by the merger.
3934 	 */
3935 	merge_inode_lists(inodedep);
3936 	if (TAILQ_FIRST(&inodedep->id_inoupdt) != NULL)
3937 		handle_allocdirect_partdone(TAILQ_FIRST(&inodedep->id_inoupdt));
3938 	/*
3939 	 * Now that the inode has been pushed into the buffer, the
3940 	 * operations dependent on the inode being written to disk
3941 	 * can be moved to the id_bufwait so that they will be
3942 	 * processed when the buffer I/O completes.
3943 	 */
3944 	while ((wk = LIST_FIRST(&inodedep->id_inowait)) != NULL) {
3945 		WORKLIST_REMOVE(wk);
3946 		WORKLIST_INSERT(&inodedep->id_bufwait, wk);
3947 	}
3948 	/*
3949 	 * Newly allocated inodes cannot be written until the bitmap
3950 	 * that allocates them have been written (indicated by
3951 	 * DEPCOMPLETE being set in id_state). If we are doing a
3952 	 * forced sync (e.g., an fsync on a file), we force the bitmap
3953 	 * to be written so that the update can be done.
3954 	 */
3955 	if ((inodedep->id_state & DEPCOMPLETE) != 0 || waitfor == 0) {
3956 		FREE_LOCK(&lk);
3957 		return;
3958 	}
3959 	gotit = getdirtybuf(&inodedep->id_buf, MNT_WAIT);
3960 	FREE_LOCK(&lk);
3961 	if (gotit &&
3962 	    (error = VOP_BWRITE(inodedep->id_buf->b_vp, inodedep->id_buf)) != 0)
3963 		softdep_error("softdep_update_inodeblock: bwrite", error);
3964 	if ((inodedep->id_state & DEPCOMPLETE) == 0)
3965 		panic("softdep_update_inodeblock: update failed");
3966 }
3967 
3968 /*
3969  * Merge the new inode dependency list (id_newinoupdt) into the old
3970  * inode dependency list (id_inoupdt). This routine must be called
3971  * with splbio interrupts blocked.
3972  */
3973 static void
3974 merge_inode_lists(inodedep)
3975 	struct inodedep *inodedep;
3976 {
3977 	struct allocdirect *listadp, *newadp;
3978 
3979 	newadp = TAILQ_FIRST(&inodedep->id_newinoupdt);
3980 	for (listadp = TAILQ_FIRST(&inodedep->id_inoupdt); listadp && newadp;) {
3981 		if (listadp->ad_lbn < newadp->ad_lbn) {
3982 			listadp = TAILQ_NEXT(listadp, ad_next);
3983 			continue;
3984 		}
3985 		TAILQ_REMOVE(&inodedep->id_newinoupdt, newadp, ad_next);
3986 		TAILQ_INSERT_BEFORE(listadp, newadp, ad_next);
3987 		if (listadp->ad_lbn == newadp->ad_lbn) {
3988 			allocdirect_merge(&inodedep->id_inoupdt, newadp,
3989 			    listadp);
3990 			listadp = newadp;
3991 		}
3992 		newadp = TAILQ_FIRST(&inodedep->id_newinoupdt);
3993 	}
3994 	while ((newadp = TAILQ_FIRST(&inodedep->id_newinoupdt)) != NULL) {
3995 		TAILQ_REMOVE(&inodedep->id_newinoupdt, newadp, ad_next);
3996 		TAILQ_INSERT_TAIL(&inodedep->id_inoupdt, newadp, ad_next);
3997 	}
3998 }
3999 
4000 /*
4001  * If we are doing an fsync, then we must ensure that any directory
4002  * entries for the inode have been written after the inode gets to disk.
4003  */
4004 static int
4005 softdep_fsync(vp)
4006 	struct vnode *vp;	/* the "in_core" copy of the inode */
4007 {
4008 	struct inodedep *inodedep;
4009 	struct pagedep *pagedep;
4010 	struct worklist *wk;
4011 	struct diradd *dap;
4012 	struct mount *mnt;
4013 	struct vnode *pvp;
4014 	struct inode *ip;
4015 	struct buf *bp;
4016 	struct fs *fs;
4017 	struct thread *td = curthread;		/* XXX */
4018 	int error, flushparent;
4019 	ino_t parentino;
4020 	ufs_lbn_t lbn;
4021 
4022 	ip = VTOI(vp);
4023 	fs = ip->i_fs;
4024 	ACQUIRE_LOCK(&lk);
4025 	if (inodedep_lookup(fs, ip->i_number, 0, &inodedep) == 0) {
4026 		FREE_LOCK(&lk);
4027 		return (0);
4028 	}
4029 	if (LIST_FIRST(&inodedep->id_inowait) != NULL ||
4030 	    LIST_FIRST(&inodedep->id_bufwait) != NULL ||
4031 	    TAILQ_FIRST(&inodedep->id_inoupdt) != NULL ||
4032 	    TAILQ_FIRST(&inodedep->id_newinoupdt) != NULL) {
4033 		FREE_LOCK(&lk);
4034 		panic("softdep_fsync: pending ops");
4035 	}
4036 	for (error = 0, flushparent = 0; ; ) {
4037 		if ((wk = LIST_FIRST(&inodedep->id_pendinghd)) == NULL)
4038 			break;
4039 		if (wk->wk_type != D_DIRADD) {
4040 			FREE_LOCK(&lk);
4041 			panic("softdep_fsync: Unexpected type %s",
4042 			    TYPENAME(wk->wk_type));
4043 		}
4044 		dap = WK_DIRADD(wk);
4045 		/*
4046 		 * Flush our parent if this directory entry
4047 		 * has a MKDIR_PARENT dependency.
4048 		 */
4049 		if (dap->da_state & DIRCHG)
4050 			pagedep = dap->da_previous->dm_pagedep;
4051 		else
4052 			pagedep = dap->da_pagedep;
4053 		mnt = pagedep->pd_mnt;
4054 		parentino = pagedep->pd_ino;
4055 		lbn = pagedep->pd_lbn;
4056 		if ((dap->da_state & (MKDIR_BODY | COMPLETE)) != COMPLETE) {
4057 			FREE_LOCK(&lk);
4058 			panic("softdep_fsync: dirty");
4059 		}
4060 		flushparent = dap->da_state & MKDIR_PARENT;
4061 		/*
4062 		 * If we are being fsync'ed as part of vgone'ing this vnode,
4063 		 * then we will not be able to release and recover the
4064 		 * vnode below, so we just have to give up on writing its
4065 		 * directory entry out. It will eventually be written, just
4066 		 * not now, but then the user was not asking to have it
4067 		 * written, so we are not breaking any promises.
4068 		 */
4069 		if (vp->v_flag & VRECLAIMED)
4070 			break;
4071 		/*
4072 		 * We prevent deadlock by always fetching inodes from the
4073 		 * root, moving down the directory tree. Thus, when fetching
4074 		 * our parent directory, we must unlock ourselves before
4075 		 * requesting the lock on our parent. See the comment in
4076 		 * ufs_lookup for details on possible races.
4077 		 */
4078 		FREE_LOCK(&lk);
4079 		VOP_UNLOCK(vp, 0, td);
4080 		error = VFS_VGET(mnt, parentino, &pvp);
4081 		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
4082 		if (error != 0)
4083 			return (error);
4084 		if (flushparent) {
4085 			if ((error = UFS_UPDATE(pvp, 1)) != 0) {
4086 				vput(pvp);
4087 				return (error);
4088 			}
4089 		}
4090 		/*
4091 		 * Flush directory page containing the inode's name.
4092 		 */
4093 		error = bread(pvp, lbn, blksize(fs, VTOI(pvp), lbn), &bp);
4094 		if (error == 0)
4095 			error = VOP_BWRITE(bp->b_vp, bp);
4096 		vput(pvp);
4097 		if (error != 0)
4098 			return (error);
4099 		ACQUIRE_LOCK(&lk);
4100 		if (inodedep_lookup(fs, ip->i_number, 0, &inodedep) == 0)
4101 			break;
4102 	}
4103 	FREE_LOCK(&lk);
4104 	return (0);
4105 }
4106 
4107 /*
4108  * Flush all the dirty bitmaps associated with the block device
4109  * before flushing the rest of the dirty blocks so as to reduce
4110  * the number of dependencies that will have to be rolled back.
4111  */
4112 static int softdep_fsync_mountdev_bp(struct buf *bp, void *data);
4113 
4114 void
4115 softdep_fsync_mountdev(vp)
4116 	struct vnode *vp;
4117 {
4118 	if (!vn_isdisk(vp, NULL))
4119 		panic("softdep_fsync_mountdev: vnode not a disk");
4120 	ACQUIRE_LOCK(&lk);
4121 	crit_enter();
4122 	RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree, NULL,
4123 		softdep_fsync_mountdev_bp, vp);
4124 	crit_exit();
4125 	drain_output(vp, 1);
4126 	FREE_LOCK(&lk);
4127 }
4128 
4129 static int
4130 softdep_fsync_mountdev_bp(struct buf *bp, void *data)
4131 {
4132 	struct worklist *wk;
4133 	struct vnode *vp = data;
4134 
4135 	/*
4136 	 * If it is already scheduled, skip to the next buffer.
4137 	 */
4138 	if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT))
4139 		return(0);
4140 	if (bp->b_vp != vp || (bp->b_flags & B_DELWRI) == 0) {
4141 		BUF_UNLOCK(bp);
4142 		printf("softdep_fsync_mountdev_bp: warning, buffer %p ripped out from under vnode %p\n", bp, vp);
4143 		return(0);
4144 	}
4145 	/*
4146 	 * We are only interested in bitmaps with outstanding
4147 	 * dependencies.
4148 	 */
4149 	if ((wk = LIST_FIRST(&bp->b_dep)) == NULL ||
4150 	    wk->wk_type != D_BMSAFEMAP ||
4151 	    (bp->b_xflags & BX_BKGRDINPROG)) {
4152 		BUF_UNLOCK(bp);
4153 		return(0);
4154 	}
4155 	bremfree(bp);
4156 	FREE_LOCK(&lk);
4157 	(void) bawrite(bp);
4158 	ACQUIRE_LOCK(&lk);
4159 	return(0);
4160 }
4161 
4162 /*
4163  * This routine is called when we are trying to synchronously flush a
4164  * file. This routine must eliminate any filesystem metadata dependencies
4165  * so that the syncing routine can succeed by pushing the dirty blocks
4166  * associated with the file. If any I/O errors occur, they are returned.
4167  */
4168 struct softdep_sync_metadata_info {
4169 	struct vnode *vp;
4170 	int waitfor;
4171 };
4172 
4173 static int softdep_sync_metadata_bp(struct buf *bp, void *data);
4174 
4175 int
4176 softdep_sync_metadata(struct vnode *vp, struct thread *td)
4177 {
4178 	struct softdep_sync_metadata_info info;
4179 	int error, waitfor;
4180 
4181 	/*
4182 	 * Check whether this vnode is involved in a filesystem
4183 	 * that is doing soft dependency processing.
4184 	 */
4185 	if (!vn_isdisk(vp, NULL)) {
4186 		if (!DOINGSOFTDEP(vp))
4187 			return (0);
4188 	} else
4189 		if (vp->v_rdev->si_mountpoint == NULL ||
4190 		    (vp->v_rdev->si_mountpoint->mnt_flag & MNT_SOFTDEP) == 0)
4191 			return (0);
4192 	/*
4193 	 * Ensure that any direct block dependencies have been cleared.
4194 	 */
4195 	ACQUIRE_LOCK(&lk);
4196 	if ((error = flush_inodedep_deps(VTOI(vp)->i_fs, VTOI(vp)->i_number))) {
4197 		FREE_LOCK(&lk);
4198 		return (error);
4199 	}
4200 	/*
4201 	 * For most files, the only metadata dependencies are the
4202 	 * cylinder group maps that allocate their inode or blocks.
4203 	 * The block allocation dependencies can be found by traversing
4204 	 * the dependency lists for any buffers that remain on their
4205 	 * dirty buffer list. The inode allocation dependency will
4206 	 * be resolved when the inode is updated with MNT_WAIT.
4207 	 * This work is done in two passes. The first pass grabs most
4208 	 * of the buffers and begins asynchronously writing them. The
4209 	 * only way to wait for these asynchronous writes is to sleep
4210 	 * on the filesystem vnode which may stay busy for a long time
4211 	 * if the filesystem is active. So, instead, we make a second
4212 	 * pass over the dependencies blocking on each write. In the
4213 	 * usual case we will be blocking against a write that we
4214 	 * initiated, so when it is done the dependency will have been
4215 	 * resolved. Thus the second pass is expected to end quickly.
4216 	 */
4217 	waitfor = MNT_NOWAIT;
4218 top:
4219 	/*
4220 	 * We must wait for any I/O in progress to finish so that
4221 	 * all potential buffers on the dirty list will be visible.
4222 	 */
4223 	drain_output(vp, 1);
4224 	info.vp = vp;
4225 	info.waitfor = waitfor;
4226 	crit_enter();
4227 	error = RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree, NULL,
4228 			softdep_sync_metadata_bp, &info);
4229 	crit_exit();
4230 	if (error < 0) {
4231 		FREE_LOCK(&lk);
4232 		return(-error);	/* error code */
4233 	}
4234 
4235 	/*
4236 	 * The brief unlock is to allow any pent up dependency
4237 	 * processing to be done.  Then proceed with the second pass.
4238 	 */
4239 	if (waitfor == MNT_NOWAIT) {
4240 		waitfor = MNT_WAIT;
4241 		FREE_LOCK(&lk);
4242 		ACQUIRE_LOCK(&lk);
4243 		goto top;
4244 	}
4245 
4246 	/*
4247 	 * If we have managed to get rid of all the dirty buffers,
4248 	 * then we are done. For certain directories and block
4249 	 * devices, we may need to do further work.
4250 	 *
4251 	 * We must wait for any I/O in progress to finish so that
4252 	 * all potential buffers on the dirty list will be visible.
4253 	 */
4254 	drain_output(vp, 1);
4255 	if (RB_EMPTY(&vp->v_rbdirty_tree)) {
4256 		FREE_LOCK(&lk);
4257 		return (0);
4258 	}
4259 
4260 	FREE_LOCK(&lk);
4261 	/*
4262 	 * If we are trying to sync a block device, some of its buffers may
4263 	 * contain metadata that cannot be written until the contents of some
4264 	 * partially written files have been written to disk. The only easy
4265 	 * way to accomplish this is to sync the entire filesystem (luckily
4266 	 * this happens rarely).
4267 	 */
4268 	if (vn_isdisk(vp, NULL) &&
4269 	    vp->v_rdev &&
4270 	    vp->v_rdev->si_mountpoint && !VOP_ISLOCKED(vp, NULL) &&
4271 	    (error = VFS_SYNC(vp->v_rdev->si_mountpoint, MNT_WAIT, td)) != 0)
4272 		return (error);
4273 	return (0);
4274 }
4275 
4276 static int
4277 softdep_sync_metadata_bp(struct buf *bp, void *data)
4278 {
4279 	struct softdep_sync_metadata_info *info = data;
4280 	struct pagedep *pagedep;
4281 	struct allocdirect *adp;
4282 	struct allocindir *aip;
4283 	struct worklist *wk;
4284 	struct buf *nbp;
4285 	int error;
4286 	int i;
4287 
4288 	if (getdirtybuf(&bp, MNT_WAIT) == 0) {
4289 		printf("softdep_sync_metadata_bp(1): caught buf %p going away\n", bp);
4290 		return (1);
4291 	}
4292 	if (bp->b_vp != info->vp || (bp->b_flags & B_DELWRI) == 0) {
4293 		printf("softdep_sync_metadata_bp(2): caught buf %p going away vp %p\n", bp, info->vp);
4294 		BUF_UNLOCK(bp);
4295 		return(1);
4296 	}
4297 
4298 	/*
4299 	 * As we hold the buffer locked, none of its dependencies
4300 	 * will disappear.
4301 	 */
4302 	LIST_FOREACH(wk, &bp->b_dep, wk_list) {
4303 		switch (wk->wk_type) {
4304 
4305 		case D_ALLOCDIRECT:
4306 			adp = WK_ALLOCDIRECT(wk);
4307 			if (adp->ad_state & DEPCOMPLETE)
4308 				break;
4309 			nbp = adp->ad_buf;
4310 			if (getdirtybuf(&nbp, info->waitfor) == 0)
4311 				break;
4312 			FREE_LOCK(&lk);
4313 			if (info->waitfor == MNT_NOWAIT) {
4314 				bawrite(nbp);
4315 			} else if ((error = VOP_BWRITE(nbp->b_vp, nbp)) != 0) {
4316 				bawrite(bp);
4317 				ACQUIRE_LOCK(&lk);
4318 				return (-error);
4319 			}
4320 			ACQUIRE_LOCK(&lk);
4321 			break;
4322 
4323 		case D_ALLOCINDIR:
4324 			aip = WK_ALLOCINDIR(wk);
4325 			if (aip->ai_state & DEPCOMPLETE)
4326 				break;
4327 			nbp = aip->ai_buf;
4328 			if (getdirtybuf(&nbp, info->waitfor) == 0)
4329 				break;
4330 			FREE_LOCK(&lk);
4331 			if (info->waitfor == MNT_NOWAIT) {
4332 				bawrite(nbp);
4333 			} else if ((error = VOP_BWRITE(nbp->b_vp, nbp)) != 0) {
4334 				bawrite(bp);
4335 				ACQUIRE_LOCK(&lk);
4336 				return (-error);
4337 			}
4338 			ACQUIRE_LOCK(&lk);
4339 			break;
4340 
4341 		case D_INDIRDEP:
4342 		restart:
4343 
4344 			LIST_FOREACH(aip, &WK_INDIRDEP(wk)->ir_deplisthd, ai_next) {
4345 				if (aip->ai_state & DEPCOMPLETE)
4346 					continue;
4347 				nbp = aip->ai_buf;
4348 				if (getdirtybuf(&nbp, MNT_WAIT) == 0)
4349 					goto restart;
4350 				FREE_LOCK(&lk);
4351 				if ((error = VOP_BWRITE(nbp->b_vp, nbp)) != 0) {
4352 					bawrite(bp);
4353 					ACQUIRE_LOCK(&lk);
4354 					return (-error);
4355 				}
4356 				ACQUIRE_LOCK(&lk);
4357 				goto restart;
4358 			}
4359 			break;
4360 
4361 		case D_INODEDEP:
4362 			if ((error = flush_inodedep_deps(WK_INODEDEP(wk)->id_fs,
4363 			    WK_INODEDEP(wk)->id_ino)) != 0) {
4364 				FREE_LOCK(&lk);
4365 				bawrite(bp);
4366 				ACQUIRE_LOCK(&lk);
4367 				return (-error);
4368 			}
4369 			break;
4370 
4371 		case D_PAGEDEP:
4372 			/*
4373 			 * We are trying to sync a directory that may
4374 			 * have dependencies on both its own metadata
4375 			 * and/or dependencies on the inodes of any
4376 			 * recently allocated files. We walk its diradd
4377 			 * lists pushing out the associated inode.
4378 			 */
4379 			pagedep = WK_PAGEDEP(wk);
4380 			for (i = 0; i < DAHASHSZ; i++) {
4381 				if (LIST_FIRST(&pagedep->pd_diraddhd[i]) == 0)
4382 					continue;
4383 				if ((error =
4384 				    flush_pagedep_deps(info->vp,
4385 						pagedep->pd_mnt,
4386 						&pagedep->pd_diraddhd[i]))) {
4387 					FREE_LOCK(&lk);
4388 					bawrite(bp);
4389 					ACQUIRE_LOCK(&lk);
4390 					return (-error);
4391 				}
4392 			}
4393 			break;
4394 
4395 		case D_MKDIR:
4396 			/*
4397 			 * This case should never happen if the vnode has
4398 			 * been properly sync'ed. However, if this function
4399 			 * is used at a place where the vnode has not yet
4400 			 * been sync'ed, this dependency can show up. So,
4401 			 * rather than panic, just flush it.
4402 			 */
4403 			nbp = WK_MKDIR(wk)->md_buf;
4404 			if (getdirtybuf(&nbp, info->waitfor) == 0)
4405 				break;
4406 			FREE_LOCK(&lk);
4407 			if (info->waitfor == MNT_NOWAIT) {
4408 				bawrite(nbp);
4409 			} else if ((error = VOP_BWRITE(nbp->b_vp, nbp)) != 0) {
4410 				bawrite(bp);
4411 				ACQUIRE_LOCK(&lk);
4412 				return (-error);
4413 			}
4414 			ACQUIRE_LOCK(&lk);
4415 			break;
4416 
4417 		case D_BMSAFEMAP:
4418 			/*
4419 			 * This case should never happen if the vnode has
4420 			 * been properly sync'ed. However, if this function
4421 			 * is used at a place where the vnode has not yet
4422 			 * been sync'ed, this dependency can show up. So,
4423 			 * rather than panic, just flush it.
4424 			 *
4425 			 * nbp can wind up == bp if a device node for the
4426 			 * same filesystem is being fsynced at the same time,
4427 			 * leading to a panic if we don't catch the case.
4428 			 */
4429 			nbp = WK_BMSAFEMAP(wk)->sm_buf;
4430 			if (nbp == bp)
4431 				break;
4432 			if (getdirtybuf(&nbp, info->waitfor) == 0)
4433 				break;
4434 			FREE_LOCK(&lk);
4435 			if (info->waitfor == MNT_NOWAIT) {
4436 				bawrite(nbp);
4437 			} else if ((error = VOP_BWRITE(nbp->b_vp, nbp)) != 0) {
4438 				bawrite(bp);
4439 				ACQUIRE_LOCK(&lk);
4440 				return (-error);
4441 			}
4442 			ACQUIRE_LOCK(&lk);
4443 			break;
4444 
4445 		default:
4446 			FREE_LOCK(&lk);
4447 			panic("softdep_sync_metadata: Unknown type %s",
4448 			    TYPENAME(wk->wk_type));
4449 			/* NOTREACHED */
4450 		}
4451 	}
4452 	FREE_LOCK(&lk);
4453 	bawrite(bp);
4454 	ACQUIRE_LOCK(&lk);
4455 	return(0);
4456 }
4457 
4458 /*
4459  * Flush the dependencies associated with an inodedep.
4460  * Called with splbio blocked.
4461  */
4462 static int
4463 flush_inodedep_deps(fs, ino)
4464 	struct fs *fs;
4465 	ino_t ino;
4466 {
4467 	struct inodedep *inodedep;
4468 	struct allocdirect *adp;
4469 	int error, waitfor;
4470 	struct buf *bp;
4471 
4472 	/*
4473 	 * This work is done in two passes. The first pass grabs most
4474 	 * of the buffers and begins asynchronously writing them. The
4475 	 * only way to wait for these asynchronous writes is to sleep
4476 	 * on the filesystem vnode which may stay busy for a long time
4477 	 * if the filesystem is active. So, instead, we make a second
4478 	 * pass over the dependencies blocking on each write. In the
4479 	 * usual case we will be blocking against a write that we
4480 	 * initiated, so when it is done the dependency will have been
4481 	 * resolved. Thus the second pass is expected to end quickly.
4482 	 * We give a brief window at the top of the loop to allow
4483 	 * any pending I/O to complete.
4484 	 */
4485 	for (waitfor = MNT_NOWAIT; ; ) {
4486 		FREE_LOCK(&lk);
4487 		ACQUIRE_LOCK(&lk);
4488 		if (inodedep_lookup(fs, ino, 0, &inodedep) == 0)
4489 			return (0);
4490 		TAILQ_FOREACH(adp, &inodedep->id_inoupdt, ad_next) {
4491 			if (adp->ad_state & DEPCOMPLETE)
4492 				continue;
4493 			bp = adp->ad_buf;
4494 			if (getdirtybuf(&bp, waitfor) == 0) {
4495 				if (waitfor == MNT_NOWAIT)
4496 					continue;
4497 				break;
4498 			}
4499 			FREE_LOCK(&lk);
4500 			if (waitfor == MNT_NOWAIT) {
4501 				bawrite(bp);
4502 			} else if ((error = VOP_BWRITE(bp->b_vp, bp)) != 0) {
4503 				ACQUIRE_LOCK(&lk);
4504 				return (error);
4505 			}
4506 			ACQUIRE_LOCK(&lk);
4507 			break;
4508 		}
4509 		if (adp != NULL)
4510 			continue;
4511 		TAILQ_FOREACH(adp, &inodedep->id_newinoupdt, ad_next) {
4512 			if (adp->ad_state & DEPCOMPLETE)
4513 				continue;
4514 			bp = adp->ad_buf;
4515 			if (getdirtybuf(&bp, waitfor) == 0) {
4516 				if (waitfor == MNT_NOWAIT)
4517 					continue;
4518 				break;
4519 			}
4520 			FREE_LOCK(&lk);
4521 			if (waitfor == MNT_NOWAIT) {
4522 				bawrite(bp);
4523 			} else if ((error = VOP_BWRITE(bp->b_vp, bp)) != 0) {
4524 				ACQUIRE_LOCK(&lk);
4525 				return (error);
4526 			}
4527 			ACQUIRE_LOCK(&lk);
4528 			break;
4529 		}
4530 		if (adp != NULL)
4531 			continue;
4532 		/*
4533 		 * If pass2, we are done, otherwise do pass 2.
4534 		 */
4535 		if (waitfor == MNT_WAIT)
4536 			break;
4537 		waitfor = MNT_WAIT;
4538 	}
4539 	/*
4540 	 * Try freeing inodedep in case all dependencies have been removed.
4541 	 */
4542 	if (inodedep_lookup(fs, ino, 0, &inodedep) != 0)
4543 		(void) free_inodedep(inodedep);
4544 	return (0);
4545 }
4546 
4547 /*
4548  * Eliminate a pagedep dependency by flushing out all its diradd dependencies.
4549  * Called with splbio blocked.
4550  */
4551 static int
4552 flush_pagedep_deps(pvp, mp, diraddhdp)
4553 	struct vnode *pvp;
4554 	struct mount *mp;
4555 	struct diraddhd *diraddhdp;
4556 {
4557 	struct thread *td = curthread;		/* XXX */
4558 	struct inodedep *inodedep;
4559 	struct ufsmount *ump;
4560 	struct diradd *dap;
4561 	struct vnode *vp;
4562 	int gotit, error = 0;
4563 	struct buf *bp;
4564 	ino_t inum;
4565 
4566 	ump = VFSTOUFS(mp);
4567 	while ((dap = LIST_FIRST(diraddhdp)) != NULL) {
4568 		/*
4569 		 * Flush ourselves if this directory entry
4570 		 * has a MKDIR_PARENT dependency.
4571 		 */
4572 		if (dap->da_state & MKDIR_PARENT) {
4573 			FREE_LOCK(&lk);
4574 			if ((error = UFS_UPDATE(pvp, 1)) != 0)
4575 				break;
4576 			ACQUIRE_LOCK(&lk);
4577 			/*
4578 			 * If that cleared dependencies, go on to next.
4579 			 */
4580 			if (dap != LIST_FIRST(diraddhdp))
4581 				continue;
4582 			if (dap->da_state & MKDIR_PARENT) {
4583 				FREE_LOCK(&lk);
4584 				panic("flush_pagedep_deps: MKDIR_PARENT");
4585 			}
4586 		}
4587 		/*
4588 		 * A newly allocated directory must have its "." and
4589 		 * ".." entries written out before its name can be
4590 		 * committed in its parent. We do not want or need
4591 		 * the full semantics of a synchronous VOP_FSYNC as
4592 		 * that may end up here again, once for each directory
4593 		 * level in the filesystem. Instead, we push the blocks
4594 		 * and wait for them to clear. We have to fsync twice
4595 		 * because the first call may choose to defer blocks
4596 		 * that still have dependencies, but deferral will
4597 		 * happen at most once.
4598 		 */
4599 		inum = dap->da_newinum;
4600 		if (dap->da_state & MKDIR_BODY) {
4601 			FREE_LOCK(&lk);
4602 			if ((error = VFS_VGET(mp, inum, &vp)) != 0)
4603 				break;
4604 			if ((error=VOP_FSYNC(vp, MNT_NOWAIT, td)) ||
4605 			    (error=VOP_FSYNC(vp, MNT_NOWAIT, td))) {
4606 				vput(vp);
4607 				break;
4608 			}
4609 			drain_output(vp, 0);
4610 			vput(vp);
4611 			ACQUIRE_LOCK(&lk);
4612 			/*
4613 			 * If that cleared dependencies, go on to next.
4614 			 */
4615 			if (dap != LIST_FIRST(diraddhdp))
4616 				continue;
4617 			if (dap->da_state & MKDIR_BODY) {
4618 				FREE_LOCK(&lk);
4619 				panic("flush_pagedep_deps: MKDIR_BODY");
4620 			}
4621 		}
4622 		/*
4623 		 * Flush the inode on which the directory entry depends.
4624 		 * Having accounted for MKDIR_PARENT and MKDIR_BODY above,
4625 		 * the only remaining dependency is that the updated inode
4626 		 * count must get pushed to disk. The inode has already
4627 		 * been pushed into its inode buffer (via VOP_UPDATE) at
4628 		 * the time of the reference count change. So we need only
4629 		 * locate that buffer, ensure that there will be no rollback
4630 		 * caused by a bitmap dependency, then write the inode buffer.
4631 		 */
4632 		if (inodedep_lookup(ump->um_fs, inum, 0, &inodedep) == 0) {
4633 			FREE_LOCK(&lk);
4634 			panic("flush_pagedep_deps: lost inode");
4635 		}
4636 		/*
4637 		 * If the inode still has bitmap dependencies,
4638 		 * push them to disk.
4639 		 */
4640 		if ((inodedep->id_state & DEPCOMPLETE) == 0) {
4641 			gotit = getdirtybuf(&inodedep->id_buf, MNT_WAIT);
4642 			FREE_LOCK(&lk);
4643 			if (gotit &&
4644 			    (error = VOP_BWRITE(inodedep->id_buf->b_vp,
4645 			     inodedep->id_buf)) != 0)
4646 				break;
4647 			ACQUIRE_LOCK(&lk);
4648 			if (dap != LIST_FIRST(diraddhdp))
4649 				continue;
4650 		}
4651 		/*
4652 		 * If the inode is still sitting in a buffer waiting
4653 		 * to be written, push it to disk.
4654 		 */
4655 		FREE_LOCK(&lk);
4656 		if ((error = bread(ump->um_devvp,
4657 		    fsbtodb(ump->um_fs, ino_to_fsba(ump->um_fs, inum)),
4658 		    (int)ump->um_fs->fs_bsize, &bp)) != 0)
4659 			break;
4660 		if ((error = VOP_BWRITE(bp->b_vp, bp)) != 0)
4661 			break;
4662 		ACQUIRE_LOCK(&lk);
4663 		/*
4664 		 * If we have failed to get rid of all the dependencies
4665 		 * then something is seriously wrong.
4666 		 */
4667 		if (dap == LIST_FIRST(diraddhdp)) {
4668 			FREE_LOCK(&lk);
4669 			panic("flush_pagedep_deps: flush failed");
4670 		}
4671 	}
4672 	if (error)
4673 		ACQUIRE_LOCK(&lk);
4674 	return (error);
4675 }
4676 
4677 /*
4678  * A large burst of file addition or deletion activity can drive the
4679  * memory load excessively high. First attempt to slow things down
4680  * using the techniques below. If that fails, this routine requests
4681  * the offending operations to fall back to running synchronously
4682  * until the memory load returns to a reasonable level.
4683  */
4684 int
4685 softdep_slowdown(vp)
4686 	struct vnode *vp;
4687 {
4688 	int max_softdeps_hard;
4689 
4690 	max_softdeps_hard = max_softdeps * 11 / 10;
4691 	if (num_dirrem < max_softdeps_hard / 2 &&
4692 	    num_inodedep < max_softdeps_hard)
4693 		return (0);
4694 	stat_sync_limit_hit += 1;
4695 	return (1);
4696 }
4697 
4698 /*
4699  * If memory utilization has gotten too high, deliberately slow things
4700  * down and speed up the I/O processing.
4701  */
4702 static int
4703 request_cleanup(resource, islocked)
4704 	int resource;
4705 	int islocked;
4706 {
4707 	struct thread *td = curthread;		/* XXX */
4708 
4709 	/*
4710 	 * We never hold up the filesystem syncer process.
4711 	 */
4712 	if (td == filesys_syncer)
4713 		return (0);
4714 	/*
4715 	 * First check to see if the work list has gotten backlogged.
4716 	 * If it has, co-opt this process to help clean up two entries.
4717 	 * Because this process may hold inodes locked, we cannot
4718 	 * handle any remove requests that might block on a locked
4719 	 * inode as that could lead to deadlock.
4720 	 */
4721 	if (num_on_worklist > max_softdeps / 10) {
4722 		if (islocked)
4723 			FREE_LOCK(&lk);
4724 		process_worklist_item(NULL, LK_NOWAIT);
4725 		process_worklist_item(NULL, LK_NOWAIT);
4726 		stat_worklist_push += 2;
4727 		if (islocked)
4728 			ACQUIRE_LOCK(&lk);
4729 		return(1);
4730 	}
4731 
4732 	/*
4733 	 * If we are resource constrained on inode dependencies, try
4734 	 * flushing some dirty inodes. Otherwise, we are constrained
4735 	 * by file deletions, so try accelerating flushes of directories
4736 	 * with removal dependencies. We would like to do the cleanup
4737 	 * here, but we probably hold an inode locked at this point and
4738 	 * that might deadlock against one that we try to clean. So,
4739 	 * the best that we can do is request the syncer daemon to do
4740 	 * the cleanup for us.
4741 	 */
4742 	switch (resource) {
4743 
4744 	case FLUSH_INODES:
4745 		stat_ino_limit_push += 1;
4746 		req_clear_inodedeps += 1;
4747 		stat_countp = &stat_ino_limit_hit;
4748 		break;
4749 
4750 	case FLUSH_REMOVE:
4751 		stat_blk_limit_push += 1;
4752 		req_clear_remove += 1;
4753 		stat_countp = &stat_blk_limit_hit;
4754 		break;
4755 
4756 	default:
4757 		if (islocked)
4758 			FREE_LOCK(&lk);
4759 		panic("request_cleanup: unknown type");
4760 	}
4761 	/*
4762 	 * Hopefully the syncer daemon will catch up and awaken us.
4763 	 * We wait at most tickdelay before proceeding in any case.
4764 	 */
4765 	if (islocked == 0)
4766 		ACQUIRE_LOCK(&lk);
4767 	crit_enter();
4768 	proc_waiting += 1;
4769 	if (!callout_active(&handle))
4770 		callout_reset(&handle, tickdelay > 2 ? tickdelay : 2,
4771 			      pause_timer, NULL);
4772 	interlocked_sleep(&lk, SLEEP, (caddr_t)&proc_waiting, 0,
4773 	    "softupdate", 0);
4774 	proc_waiting -= 1;
4775 	crit_exit();
4776 	if (islocked == 0)
4777 		FREE_LOCK(&lk);
4778 	return (1);
4779 }
4780 
4781 /*
4782  * Awaken processes pausing in request_cleanup and clear proc_waiting
4783  * to indicate that there is no longer a timer running.
4784  */
4785 void
4786 pause_timer(arg)
4787 	void *arg;
4788 {
4789 	*stat_countp += 1;
4790 	wakeup_one(&proc_waiting);
4791 	if (proc_waiting > 0)
4792 		callout_reset(&handle, tickdelay > 2 ? tickdelay : 2,
4793 			      pause_timer, NULL);
4794 	else
4795 		callout_deactivate(&handle);
4796 }
4797 
4798 /*
4799  * Flush out a directory with at least one removal dependency in an effort to
4800  * reduce the number of dirrem, freefile, and freeblks dependency structures.
4801  */
4802 static void
4803 clear_remove(struct thread *td)
4804 {
4805 	struct pagedep_hashhead *pagedephd;
4806 	struct pagedep *pagedep;
4807 	static int next = 0;
4808 	struct mount *mp;
4809 	struct vnode *vp;
4810 	int error, cnt;
4811 	ino_t ino;
4812 
4813 	ACQUIRE_LOCK(&lk);
4814 	for (cnt = 0; cnt < pagedep_hash; cnt++) {
4815 		pagedephd = &pagedep_hashtbl[next++];
4816 		if (next >= pagedep_hash)
4817 			next = 0;
4818 		LIST_FOREACH(pagedep, pagedephd, pd_hash) {
4819 			if (LIST_FIRST(&pagedep->pd_dirremhd) == NULL)
4820 				continue;
4821 			mp = pagedep->pd_mnt;
4822 			ino = pagedep->pd_ino;
4823 			FREE_LOCK(&lk);
4824 			if ((error = VFS_VGET(mp, ino, &vp)) != 0) {
4825 				softdep_error("clear_remove: vget", error);
4826 				return;
4827 			}
4828 			if ((error = VOP_FSYNC(vp, MNT_NOWAIT, td)))
4829 				softdep_error("clear_remove: fsync", error);
4830 			drain_output(vp, 0);
4831 			vput(vp);
4832 			return;
4833 		}
4834 	}
4835 	FREE_LOCK(&lk);
4836 }
4837 
4838 /*
4839  * Clear out a block of dirty inodes in an effort to reduce
4840  * the number of inodedep dependency structures.
4841  */
4842 struct clear_inodedeps_info {
4843 	struct fs *fs;
4844 	struct mount *mp;
4845 };
4846 
4847 static int
4848 clear_inodedeps_mountlist_callback(struct mount *mp, void *data)
4849 {
4850 	struct clear_inodedeps_info *info = data;
4851 
4852 	if ((mp->mnt_flag & MNT_SOFTDEP) && info->fs == VFSTOUFS(mp)->um_fs) {
4853 		info->mp = mp;
4854 		return(-1);
4855 	}
4856 	return(0);
4857 }
4858 
4859 static void
4860 clear_inodedeps(struct thread *td)
4861 {
4862 	struct clear_inodedeps_info info;
4863 	struct inodedep_hashhead *inodedephd;
4864 	struct inodedep *inodedep;
4865 	static int next = 0;
4866 	struct vnode *vp;
4867 	struct fs *fs;
4868 	int error, cnt;
4869 	ino_t firstino, lastino, ino;
4870 
4871 	ACQUIRE_LOCK(&lk);
4872 	/*
4873 	 * Pick a random inode dependency to be cleared.
4874 	 * We will then gather up all the inodes in its block
4875 	 * that have dependencies and flush them out.
4876 	 */
4877 	for (cnt = 0; cnt < inodedep_hash; cnt++) {
4878 		inodedephd = &inodedep_hashtbl[next++];
4879 		if (next >= inodedep_hash)
4880 			next = 0;
4881 		if ((inodedep = LIST_FIRST(inodedephd)) != NULL)
4882 			break;
4883 	}
4884 	if (inodedep == NULL) {
4885 		FREE_LOCK(&lk);
4886 		return;
4887 	}
4888 	/*
4889 	 * Ugly code to find mount point given pointer to superblock.
4890 	 */
4891 	fs = inodedep->id_fs;
4892 	info.mp = NULL;
4893 	info.fs = fs;
4894 	mountlist_scan(clear_inodedeps_mountlist_callback,
4895 			&info, MNTSCAN_FORWARD|MNTSCAN_NOBUSY);
4896 	/*
4897 	 * Find the last inode in the block with dependencies.
4898 	 */
4899 	firstino = inodedep->id_ino & ~(INOPB(fs) - 1);
4900 	for (lastino = firstino + INOPB(fs) - 1; lastino > firstino; lastino--)
4901 		if (inodedep_lookup(fs, lastino, 0, &inodedep) != 0)
4902 			break;
4903 	/*
4904 	 * Asynchronously push all but the last inode with dependencies.
4905 	 * Synchronously push the last inode with dependencies to ensure
4906 	 * that the inode block gets written to free up the inodedeps.
4907 	 */
4908 	for (ino = firstino; ino <= lastino; ino++) {
4909 		if (inodedep_lookup(fs, ino, 0, &inodedep) == 0)
4910 			continue;
4911 		FREE_LOCK(&lk);
4912 		if ((error = VFS_VGET(info.mp, ino, &vp)) != 0) {
4913 			softdep_error("clear_inodedeps: vget", error);
4914 			return;
4915 		}
4916 		if (ino == lastino) {
4917 			if ((error = VOP_FSYNC(vp, MNT_WAIT, td)))
4918 				softdep_error("clear_inodedeps: fsync1", error);
4919 		} else {
4920 			if ((error = VOP_FSYNC(vp, MNT_NOWAIT, td)))
4921 				softdep_error("clear_inodedeps: fsync2", error);
4922 			drain_output(vp, 0);
4923 		}
4924 		vput(vp);
4925 		ACQUIRE_LOCK(&lk);
4926 	}
4927 	FREE_LOCK(&lk);
4928 }
4929 
4930 /*
4931  * Function to determine if the buffer has outstanding dependencies
4932  * that will cause a roll-back if the buffer is written. If wantcount
4933  * is set, return number of dependencies, otherwise just yes or no.
4934  */
4935 static int
4936 softdep_count_dependencies(bp, wantcount)
4937 	struct buf *bp;
4938 	int wantcount;
4939 {
4940 	struct worklist *wk;
4941 	struct inodedep *inodedep;
4942 	struct indirdep *indirdep;
4943 	struct allocindir *aip;
4944 	struct pagedep *pagedep;
4945 	struct diradd *dap;
4946 	int i, retval;
4947 
4948 	retval = 0;
4949 	ACQUIRE_LOCK(&lk);
4950 	LIST_FOREACH(wk, &bp->b_dep, wk_list) {
4951 		switch (wk->wk_type) {
4952 
4953 		case D_INODEDEP:
4954 			inodedep = WK_INODEDEP(wk);
4955 			if ((inodedep->id_state & DEPCOMPLETE) == 0) {
4956 				/* bitmap allocation dependency */
4957 				retval += 1;
4958 				if (!wantcount)
4959 					goto out;
4960 			}
4961 			if (TAILQ_FIRST(&inodedep->id_inoupdt)) {
4962 				/* direct block pointer dependency */
4963 				retval += 1;
4964 				if (!wantcount)
4965 					goto out;
4966 			}
4967 			continue;
4968 
4969 		case D_INDIRDEP:
4970 			indirdep = WK_INDIRDEP(wk);
4971 
4972 			LIST_FOREACH(aip, &indirdep->ir_deplisthd, ai_next) {
4973 				/* indirect block pointer dependency */
4974 				retval += 1;
4975 				if (!wantcount)
4976 					goto out;
4977 			}
4978 			continue;
4979 
4980 		case D_PAGEDEP:
4981 			pagedep = WK_PAGEDEP(wk);
4982 			for (i = 0; i < DAHASHSZ; i++) {
4983 
4984 				LIST_FOREACH(dap, &pagedep->pd_diraddhd[i], da_pdlist) {
4985 					/* directory entry dependency */
4986 					retval += 1;
4987 					if (!wantcount)
4988 						goto out;
4989 				}
4990 			}
4991 			continue;
4992 
4993 		case D_BMSAFEMAP:
4994 		case D_ALLOCDIRECT:
4995 		case D_ALLOCINDIR:
4996 		case D_MKDIR:
4997 			/* never a dependency on these blocks */
4998 			continue;
4999 
5000 		default:
5001 			FREE_LOCK(&lk);
5002 			panic("softdep_check_for_rollback: Unexpected type %s",
5003 			    TYPENAME(wk->wk_type));
5004 			/* NOTREACHED */
5005 		}
5006 	}
5007 out:
5008 	FREE_LOCK(&lk);
5009 	return retval;
5010 }
5011 
5012 /*
5013  * Acquire exclusive access to a buffer.
5014  * Must be called with splbio blocked.
5015  * Return 1 if buffer was acquired.
5016  */
5017 static int
5018 getdirtybuf(bpp, waitfor)
5019 	struct buf **bpp;
5020 	int waitfor;
5021 {
5022 	struct buf *bp;
5023 	int error;
5024 
5025 	for (;;) {
5026 		if ((bp = *bpp) == NULL)
5027 			return (0);
5028 		if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT) == 0) {
5029 			if ((bp->b_xflags & BX_BKGRDINPROG) == 0)
5030 				break;
5031 			BUF_UNLOCK(bp);
5032 			if (waitfor != MNT_WAIT)
5033 				return (0);
5034 			bp->b_xflags |= BX_BKGRDWAIT;
5035 			interlocked_sleep(&lk, SLEEP, &bp->b_xflags, 0,
5036 			    "getbuf", 0);
5037 			continue;
5038 		}
5039 		if (waitfor != MNT_WAIT)
5040 			return (0);
5041 		error = interlocked_sleep(&lk, LOCKBUF, bp,
5042 		    LK_EXCLUSIVE | LK_SLEEPFAIL, 0, 0);
5043 		if (error != ENOLCK) {
5044 			FREE_LOCK(&lk);
5045 			panic("getdirtybuf: inconsistent lock");
5046 		}
5047 	}
5048 	if ((bp->b_flags & B_DELWRI) == 0) {
5049 		BUF_UNLOCK(bp);
5050 		return (0);
5051 	}
5052 	bremfree(bp);
5053 	return (1);
5054 }
5055 
5056 /*
5057  * Wait for pending output on a vnode to complete.
5058  * Must be called with vnode locked.
5059  */
5060 static void
5061 drain_output(vp, islocked)
5062 	struct vnode *vp;
5063 	int islocked;
5064 {
5065 
5066 	if (!islocked)
5067 		ACQUIRE_LOCK(&lk);
5068 	while (vp->v_track_write.bk_active) {
5069 		vp->v_track_write.bk_waitflag = 1;
5070 		interlocked_sleep(&lk, SLEEP, &vp->v_track_write,
5071 				  0, "drainvp", 0);
5072 	}
5073 	if (!islocked)
5074 		FREE_LOCK(&lk);
5075 }
5076 
5077 /*
5078  * Called whenever a buffer that is being invalidated or reallocated
5079  * contains dependencies. This should only happen if an I/O error has
5080  * occurred. The routine is called with the buffer locked.
5081  */
5082 static void
5083 softdep_deallocate_dependencies(bp)
5084 	struct buf *bp;
5085 {
5086 
5087 	if ((bp->b_flags & B_ERROR) == 0)
5088 		panic("softdep_deallocate_dependencies: dangling deps");
5089 	softdep_error(bp->b_vp->v_mount->mnt_stat.f_mntfromname, bp->b_error);
5090 	panic("softdep_deallocate_dependencies: unrecovered I/O error");
5091 }
5092 
5093 /*
5094  * Function to handle asynchronous write errors in the filesystem.
5095  */
5096 void
5097 softdep_error(func, error)
5098 	char *func;
5099 	int error;
5100 {
5101 
5102 	/* XXX should do something better! */
5103 	printf("%s: got error %d while accessing filesystem\n", func, error);
5104 }
5105