xref: /dragonfly/sys/vfs/ufs/ffs_softdep.c (revision 509221ae)
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 1.28 2005/08/02 13:03:55 joerg 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_blkno == bp->b_lblkno) {
1700 			VOP_BMAP(bp->b_vp, bp->b_lblkno, NULL, &bp->b_blkno,
1701 				NULL, NULL);
1702 		}
1703 		newindirdep->ir_savebp =
1704 		    getblk(ip->i_devvp, bp->b_blkno, bp->b_bcount, 0, 0);
1705 		BUF_KERNPROC(newindirdep->ir_savebp);
1706 		bcopy(bp->b_data, newindirdep->ir_savebp->b_data, bp->b_bcount);
1707 	}
1708 }
1709 
1710 /*
1711  * Block de-allocation dependencies.
1712  *
1713  * When blocks are de-allocated, the on-disk pointers must be nullified before
1714  * the blocks are made available for use by other files.  (The true
1715  * requirement is that old pointers must be nullified before new on-disk
1716  * pointers are set.  We chose this slightly more stringent requirement to
1717  * reduce complexity.) Our implementation handles this dependency by updating
1718  * the inode (or indirect block) appropriately but delaying the actual block
1719  * de-allocation (i.e., freemap and free space count manipulation) until
1720  * after the updated versions reach stable storage.  After the disk is
1721  * updated, the blocks can be safely de-allocated whenever it is convenient.
1722  * This implementation handles only the common case of reducing a file's
1723  * length to zero. Other cases are handled by the conventional synchronous
1724  * write approach.
1725  *
1726  * The ffs implementation with which we worked double-checks
1727  * the state of the block pointers and file size as it reduces
1728  * a file's length.  Some of this code is replicated here in our
1729  * soft updates implementation.  The freeblks->fb_chkcnt field is
1730  * used to transfer a part of this information to the procedure
1731  * that eventually de-allocates the blocks.
1732  *
1733  * This routine should be called from the routine that shortens
1734  * a file's length, before the inode's size or block pointers
1735  * are modified. It will save the block pointer information for
1736  * later release and zero the inode so that the calling routine
1737  * can release it.
1738  */
1739 struct softdep_setup_freeblocks_info {
1740 	struct fs *fs;
1741 	struct inode *ip;
1742 };
1743 
1744 static int softdep_setup_freeblocks_bp(struct buf *bp, void *data);
1745 
1746 void
1747 softdep_setup_freeblocks(ip, length)
1748 	struct inode *ip;	/* The inode whose length is to be reduced */
1749 	off_t length;		/* The new length for the file */
1750 {
1751 	struct softdep_setup_freeblocks_info info;
1752 	struct freeblks *freeblks;
1753 	struct inodedep *inodedep;
1754 	struct allocdirect *adp;
1755 	struct vnode *vp;
1756 	struct buf *bp;
1757 	struct fs *fs;
1758 	int i, error, delay;
1759 	int count;
1760 
1761 	fs = ip->i_fs;
1762 	if (length != 0)
1763 		panic("softde_setup_freeblocks: non-zero length");
1764 	MALLOC(freeblks, struct freeblks *, sizeof(struct freeblks),
1765 		M_FREEBLKS, M_SOFTDEP_FLAGS);
1766 	bzero(freeblks, sizeof(struct freeblks));
1767 	freeblks->fb_list.wk_type = D_FREEBLKS;
1768 	freeblks->fb_state = ATTACHED;
1769 	freeblks->fb_uid = ip->i_uid;
1770 	freeblks->fb_previousinum = ip->i_number;
1771 	freeblks->fb_devvp = ip->i_devvp;
1772 	freeblks->fb_fs = fs;
1773 	freeblks->fb_oldsize = ip->i_size;
1774 	freeblks->fb_newsize = length;
1775 	freeblks->fb_chkcnt = ip->i_blocks;
1776 	for (i = 0; i < NDADDR; i++) {
1777 		freeblks->fb_dblks[i] = ip->i_db[i];
1778 		ip->i_db[i] = 0;
1779 	}
1780 	for (i = 0; i < NIADDR; i++) {
1781 		freeblks->fb_iblks[i] = ip->i_ib[i];
1782 		ip->i_ib[i] = 0;
1783 	}
1784 	ip->i_blocks = 0;
1785 	ip->i_size = 0;
1786 	/*
1787 	 * Push the zero'ed inode to to its disk buffer so that we are free
1788 	 * to delete its dependencies below. Once the dependencies are gone
1789 	 * the buffer can be safely released.
1790 	 */
1791 	if ((error = bread(ip->i_devvp,
1792 	    fsbtodb(fs, ino_to_fsba(fs, ip->i_number)),
1793 	    (int)fs->fs_bsize, &bp)) != 0)
1794 		softdep_error("softdep_setup_freeblocks", error);
1795 	*((struct dinode *)bp->b_data + ino_to_fsbo(fs, ip->i_number)) =
1796 	    ip->i_din;
1797 	/*
1798 	 * Find and eliminate any inode dependencies.
1799 	 */
1800 	ACQUIRE_LOCK(&lk);
1801 	(void) inodedep_lookup(fs, ip->i_number, DEPALLOC, &inodedep);
1802 	if ((inodedep->id_state & IOSTARTED) != 0) {
1803 		FREE_LOCK(&lk);
1804 		panic("softdep_setup_freeblocks: inode busy");
1805 	}
1806 	/*
1807 	 * Add the freeblks structure to the list of operations that
1808 	 * must await the zero'ed inode being written to disk. If we
1809 	 * still have a bitmap dependency (delay == 0), then the inode
1810 	 * has never been written to disk, so we can process the
1811 	 * freeblks below once we have deleted the dependencies.
1812 	 */
1813 	delay = (inodedep->id_state & DEPCOMPLETE);
1814 	if (delay)
1815 		WORKLIST_INSERT(&inodedep->id_bufwait, &freeblks->fb_list);
1816 	/*
1817 	 * Because the file length has been truncated to zero, any
1818 	 * pending block allocation dependency structures associated
1819 	 * with this inode are obsolete and can simply be de-allocated.
1820 	 * We must first merge the two dependency lists to get rid of
1821 	 * any duplicate freefrag structures, then purge the merged list.
1822 	 */
1823 	merge_inode_lists(inodedep);
1824 	while ((adp = TAILQ_FIRST(&inodedep->id_inoupdt)) != 0)
1825 		free_allocdirect(&inodedep->id_inoupdt, adp, 1);
1826 	FREE_LOCK(&lk);
1827 	bdwrite(bp);
1828 	/*
1829 	 * We must wait for any I/O in progress to finish so that
1830 	 * all potential buffers on the dirty list will be visible.
1831 	 * Once they are all there, walk the list and get rid of
1832 	 * any dependencies.
1833 	 */
1834 	vp = ITOV(ip);
1835 	ACQUIRE_LOCK(&lk);
1836 	drain_output(vp, 1);
1837 
1838 	info.fs = fs;
1839 	info.ip = ip;
1840 	do {
1841 		count = RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree, NULL,
1842 				softdep_setup_freeblocks_bp, &info);
1843 	} while (count > 0);
1844 	if (inodedep_lookup(fs, ip->i_number, 0, &inodedep) != 0)
1845 		(void)free_inodedep(inodedep);
1846 
1847 	if (delay) {
1848 		freeblks->fb_state |= DEPCOMPLETE;
1849 		/*
1850 		 * If the inode with zeroed block pointers is now on disk
1851 		 * we can start freeing blocks. Add freeblks to the worklist
1852 		 * instead of calling  handle_workitem_freeblocks directly as
1853 		 * it is more likely that additional IO is needed to complete
1854 		 * the request here than in the !delay case.
1855 		 */
1856 		if ((freeblks->fb_state & ALLCOMPLETE) == ALLCOMPLETE)
1857 			add_to_worklist(&freeblks->fb_list);
1858 	}
1859 
1860 	FREE_LOCK(&lk);
1861 	/*
1862 	 * If the inode has never been written to disk (delay == 0),
1863 	 * then we can process the freeblks now that we have deleted
1864 	 * the dependencies.
1865 	 */
1866 	if (!delay)
1867 		handle_workitem_freeblocks(freeblks);
1868 }
1869 
1870 static int
1871 softdep_setup_freeblocks_bp(struct buf *bp, void *data)
1872 {
1873 	struct softdep_setup_freeblocks_info *info = data;
1874 	struct inodedep *inodedep;
1875 
1876 	if (getdirtybuf(&bp, MNT_WAIT) == 0)
1877 		return(-1);
1878 	(void) inodedep_lookup(info->fs, info->ip->i_number, 0, &inodedep);
1879 	deallocate_dependencies(bp, inodedep);
1880 	bp->b_flags |= B_INVAL | B_NOCACHE;
1881 	FREE_LOCK(&lk);
1882 	brelse(bp);
1883 	ACQUIRE_LOCK(&lk);
1884 	return(1);
1885 }
1886 
1887 /*
1888  * Reclaim any dependency structures from a buffer that is about to
1889  * be reallocated to a new vnode. The buffer must be locked, thus,
1890  * no I/O completion operations can occur while we are manipulating
1891  * its associated dependencies. The mutex is held so that other I/O's
1892  * associated with related dependencies do not occur.
1893  */
1894 static void
1895 deallocate_dependencies(bp, inodedep)
1896 	struct buf *bp;
1897 	struct inodedep *inodedep;
1898 {
1899 	struct worklist *wk;
1900 	struct indirdep *indirdep;
1901 	struct allocindir *aip;
1902 	struct pagedep *pagedep;
1903 	struct dirrem *dirrem;
1904 	struct diradd *dap;
1905 	int i;
1906 
1907 	while ((wk = LIST_FIRST(&bp->b_dep)) != NULL) {
1908 		switch (wk->wk_type) {
1909 
1910 		case D_INDIRDEP:
1911 			indirdep = WK_INDIRDEP(wk);
1912 			/*
1913 			 * None of the indirect pointers will ever be visible,
1914 			 * so they can simply be tossed. GOINGAWAY ensures
1915 			 * that allocated pointers will be saved in the buffer
1916 			 * cache until they are freed. Note that they will
1917 			 * only be able to be found by their physical address
1918 			 * since the inode mapping the logical address will
1919 			 * be gone. The save buffer used for the safe copy
1920 			 * was allocated in setup_allocindir_phase2 using
1921 			 * the physical address so it could be used for this
1922 			 * purpose. Hence we swap the safe copy with the real
1923 			 * copy, allowing the safe copy to be freed and holding
1924 			 * on to the real copy for later use in indir_trunc.
1925 			 */
1926 			if (indirdep->ir_state & GOINGAWAY) {
1927 				FREE_LOCK(&lk);
1928 				panic("deallocate_dependencies: already gone");
1929 			}
1930 			indirdep->ir_state |= GOINGAWAY;
1931 			while ((aip = LIST_FIRST(&indirdep->ir_deplisthd)) != 0)
1932 				free_allocindir(aip, inodedep);
1933 			if (bp->b_lblkno >= 0 ||
1934 			    bp->b_blkno != indirdep->ir_savebp->b_lblkno) {
1935 				FREE_LOCK(&lk);
1936 				panic("deallocate_dependencies: not indir");
1937 			}
1938 			bcopy(bp->b_data, indirdep->ir_savebp->b_data,
1939 			    bp->b_bcount);
1940 			WORKLIST_REMOVE(wk);
1941 			WORKLIST_INSERT(&indirdep->ir_savebp->b_dep, wk);
1942 			continue;
1943 
1944 		case D_PAGEDEP:
1945 			pagedep = WK_PAGEDEP(wk);
1946 			/*
1947 			 * None of the directory additions will ever be
1948 			 * visible, so they can simply be tossed.
1949 			 */
1950 			for (i = 0; i < DAHASHSZ; i++)
1951 				while ((dap =
1952 				    LIST_FIRST(&pagedep->pd_diraddhd[i])))
1953 					free_diradd(dap);
1954 			while ((dap = LIST_FIRST(&pagedep->pd_pendinghd)) != 0)
1955 				free_diradd(dap);
1956 			/*
1957 			 * Copy any directory remove dependencies to the list
1958 			 * to be processed after the zero'ed inode is written.
1959 			 * If the inode has already been written, then they
1960 			 * can be dumped directly onto the work list.
1961 			 */
1962 			LIST_FOREACH(dirrem, &pagedep->pd_dirremhd, dm_next) {
1963 				LIST_REMOVE(dirrem, dm_next);
1964 				dirrem->dm_dirinum = pagedep->pd_ino;
1965 				if (inodedep == NULL ||
1966 				    (inodedep->id_state & ALLCOMPLETE) ==
1967 				     ALLCOMPLETE)
1968 					add_to_worklist(&dirrem->dm_list);
1969 				else
1970 					WORKLIST_INSERT(&inodedep->id_bufwait,
1971 					    &dirrem->dm_list);
1972 			}
1973 			WORKLIST_REMOVE(&pagedep->pd_list);
1974 			LIST_REMOVE(pagedep, pd_hash);
1975 			WORKITEM_FREE(pagedep, D_PAGEDEP);
1976 			continue;
1977 
1978 		case D_ALLOCINDIR:
1979 			free_allocindir(WK_ALLOCINDIR(wk), inodedep);
1980 			continue;
1981 
1982 		case D_ALLOCDIRECT:
1983 		case D_INODEDEP:
1984 			FREE_LOCK(&lk);
1985 			panic("deallocate_dependencies: Unexpected type %s",
1986 			    TYPENAME(wk->wk_type));
1987 			/* NOTREACHED */
1988 
1989 		default:
1990 			FREE_LOCK(&lk);
1991 			panic("deallocate_dependencies: Unknown type %s",
1992 			    TYPENAME(wk->wk_type));
1993 			/* NOTREACHED */
1994 		}
1995 	}
1996 }
1997 
1998 /*
1999  * Free an allocdirect. Generate a new freefrag work request if appropriate.
2000  * This routine must be called with splbio interrupts blocked.
2001  */
2002 static void
2003 free_allocdirect(adphead, adp, delay)
2004 	struct allocdirectlst *adphead;
2005 	struct allocdirect *adp;
2006 	int delay;
2007 {
2008 
2009 #ifdef DEBUG
2010 	if (lk.lkt_held == NOHOLDER)
2011 		panic("free_allocdirect: lock not held");
2012 #endif
2013 	if ((adp->ad_state & DEPCOMPLETE) == 0)
2014 		LIST_REMOVE(adp, ad_deps);
2015 	TAILQ_REMOVE(adphead, adp, ad_next);
2016 	if ((adp->ad_state & COMPLETE) == 0)
2017 		WORKLIST_REMOVE(&adp->ad_list);
2018 	if (adp->ad_freefrag != NULL) {
2019 		if (delay)
2020 			WORKLIST_INSERT(&adp->ad_inodedep->id_bufwait,
2021 			    &adp->ad_freefrag->ff_list);
2022 		else
2023 			add_to_worklist(&adp->ad_freefrag->ff_list);
2024 	}
2025 	WORKITEM_FREE(adp, D_ALLOCDIRECT);
2026 }
2027 
2028 /*
2029  * Prepare an inode to be freed. The actual free operation is not
2030  * done until the zero'ed inode has been written to disk.
2031  */
2032 void
2033 softdep_freefile(pvp, ino, mode)
2034 		struct vnode *pvp;
2035 		ino_t ino;
2036 		int mode;
2037 {
2038 	struct inode *ip = VTOI(pvp);
2039 	struct inodedep *inodedep;
2040 	struct freefile *freefile;
2041 
2042 	/*
2043 	 * This sets up the inode de-allocation dependency.
2044 	 */
2045 	MALLOC(freefile, struct freefile *, sizeof(struct freefile),
2046 		M_FREEFILE, M_SOFTDEP_FLAGS);
2047 	freefile->fx_list.wk_type = D_FREEFILE;
2048 	freefile->fx_list.wk_state = 0;
2049 	freefile->fx_mode = mode;
2050 	freefile->fx_oldinum = ino;
2051 	freefile->fx_devvp = ip->i_devvp;
2052 	freefile->fx_fs = ip->i_fs;
2053 
2054 	/*
2055 	 * If the inodedep does not exist, then the zero'ed inode has
2056 	 * been written to disk. If the allocated inode has never been
2057 	 * written to disk, then the on-disk inode is zero'ed. In either
2058 	 * case we can free the file immediately.
2059 	 */
2060 	ACQUIRE_LOCK(&lk);
2061 	if (inodedep_lookup(ip->i_fs, ino, 0, &inodedep) == 0 ||
2062 	    check_inode_unwritten(inodedep)) {
2063 		FREE_LOCK(&lk);
2064 		handle_workitem_freefile(freefile);
2065 		return;
2066 	}
2067 	WORKLIST_INSERT(&inodedep->id_inowait, &freefile->fx_list);
2068 	FREE_LOCK(&lk);
2069 }
2070 
2071 /*
2072  * Check to see if an inode has never been written to disk. If
2073  * so free the inodedep and return success, otherwise return failure.
2074  * This routine must be called with splbio interrupts blocked.
2075  *
2076  * If we still have a bitmap dependency, then the inode has never
2077  * been written to disk. Drop the dependency as it is no longer
2078  * necessary since the inode is being deallocated. We set the
2079  * ALLCOMPLETE flags since the bitmap now properly shows that the
2080  * inode is not allocated. Even if the inode is actively being
2081  * written, it has been rolled back to its zero'ed state, so we
2082  * are ensured that a zero inode is what is on the disk. For short
2083  * lived files, this change will usually result in removing all the
2084  * dependencies from the inode so that it can be freed immediately.
2085  */
2086 static int
2087 check_inode_unwritten(inodedep)
2088 	struct inodedep *inodedep;
2089 {
2090 
2091 	if ((inodedep->id_state & DEPCOMPLETE) != 0 ||
2092 	    LIST_FIRST(&inodedep->id_pendinghd) != NULL ||
2093 	    LIST_FIRST(&inodedep->id_bufwait) != NULL ||
2094 	    LIST_FIRST(&inodedep->id_inowait) != NULL ||
2095 	    TAILQ_FIRST(&inodedep->id_inoupdt) != NULL ||
2096 	    TAILQ_FIRST(&inodedep->id_newinoupdt) != NULL ||
2097 	    inodedep->id_nlinkdelta != 0)
2098 		return (0);
2099 	inodedep->id_state |= ALLCOMPLETE;
2100 	LIST_REMOVE(inodedep, id_deps);
2101 	inodedep->id_buf = NULL;
2102 	if (inodedep->id_state & ONWORKLIST)
2103 		WORKLIST_REMOVE(&inodedep->id_list);
2104 	if (inodedep->id_savedino != NULL) {
2105 		FREE(inodedep->id_savedino, M_INODEDEP);
2106 		inodedep->id_savedino = NULL;
2107 	}
2108 	if (free_inodedep(inodedep) == 0) {
2109 		FREE_LOCK(&lk);
2110 		panic("check_inode_unwritten: busy inode");
2111 	}
2112 	return (1);
2113 }
2114 
2115 /*
2116  * Try to free an inodedep structure. Return 1 if it could be freed.
2117  */
2118 static int
2119 free_inodedep(inodedep)
2120 	struct inodedep *inodedep;
2121 {
2122 
2123 	if ((inodedep->id_state & ONWORKLIST) != 0 ||
2124 	    (inodedep->id_state & ALLCOMPLETE) != ALLCOMPLETE ||
2125 	    LIST_FIRST(&inodedep->id_pendinghd) != NULL ||
2126 	    LIST_FIRST(&inodedep->id_bufwait) != NULL ||
2127 	    LIST_FIRST(&inodedep->id_inowait) != NULL ||
2128 	    TAILQ_FIRST(&inodedep->id_inoupdt) != NULL ||
2129 	    TAILQ_FIRST(&inodedep->id_newinoupdt) != NULL ||
2130 	    inodedep->id_nlinkdelta != 0 || inodedep->id_savedino != NULL)
2131 		return (0);
2132 	LIST_REMOVE(inodedep, id_hash);
2133 	WORKITEM_FREE(inodedep, D_INODEDEP);
2134 	num_inodedep -= 1;
2135 	return (1);
2136 }
2137 
2138 /*
2139  * This workitem routine performs the block de-allocation.
2140  * The workitem is added to the pending list after the updated
2141  * inode block has been written to disk.  As mentioned above,
2142  * checks regarding the number of blocks de-allocated (compared
2143  * to the number of blocks allocated for the file) are also
2144  * performed in this function.
2145  */
2146 static void
2147 handle_workitem_freeblocks(freeblks)
2148 	struct freeblks *freeblks;
2149 {
2150 	struct inode tip;
2151 	ufs_daddr_t bn;
2152 	struct fs *fs;
2153 	int i, level, bsize;
2154 	long nblocks, blocksreleased = 0;
2155 	int error, allerror = 0;
2156 	ufs_lbn_t baselbns[NIADDR], tmpval;
2157 
2158 	tip.i_number = freeblks->fb_previousinum;
2159 	tip.i_devvp = freeblks->fb_devvp;
2160 	tip.i_dev = freeblks->fb_devvp->v_rdev;
2161 	tip.i_fs = freeblks->fb_fs;
2162 	tip.i_size = freeblks->fb_oldsize;
2163 	tip.i_uid = freeblks->fb_uid;
2164 	fs = freeblks->fb_fs;
2165 	tmpval = 1;
2166 	baselbns[0] = NDADDR;
2167 	for (i = 1; i < NIADDR; i++) {
2168 		tmpval *= NINDIR(fs);
2169 		baselbns[i] = baselbns[i - 1] + tmpval;
2170 	}
2171 	nblocks = btodb(fs->fs_bsize);
2172 	blocksreleased = 0;
2173 	/*
2174 	 * Indirect blocks first.
2175 	 */
2176 	for (level = (NIADDR - 1); level >= 0; level--) {
2177 		if ((bn = freeblks->fb_iblks[level]) == 0)
2178 			continue;
2179 		if ((error = indir_trunc(&tip, fsbtodb(fs, bn), level,
2180 		    baselbns[level], &blocksreleased)) == 0)
2181 			allerror = error;
2182 		ffs_blkfree(&tip, bn, fs->fs_bsize);
2183 		blocksreleased += nblocks;
2184 	}
2185 	/*
2186 	 * All direct blocks or frags.
2187 	 */
2188 	for (i = (NDADDR - 1); i >= 0; i--) {
2189 		if ((bn = freeblks->fb_dblks[i]) == 0)
2190 			continue;
2191 		bsize = blksize(fs, &tip, i);
2192 		ffs_blkfree(&tip, bn, bsize);
2193 		blocksreleased += btodb(bsize);
2194 	}
2195 
2196 #ifdef DIAGNOSTIC
2197 	if (freeblks->fb_chkcnt != blocksreleased)
2198 		printf("handle_workitem_freeblocks: block count\n");
2199 	if (allerror)
2200 		softdep_error("handle_workitem_freeblks", allerror);
2201 #endif /* DIAGNOSTIC */
2202 	WORKITEM_FREE(freeblks, D_FREEBLKS);
2203 }
2204 
2205 /*
2206  * Release blocks associated with the inode ip and stored in the indirect
2207  * block dbn. If level is greater than SINGLE, the block is an indirect block
2208  * and recursive calls to indirtrunc must be used to cleanse other indirect
2209  * blocks.
2210  */
2211 static int
2212 indir_trunc(ip, dbn, level, lbn, countp)
2213 	struct inode *ip;
2214 	ufs_daddr_t dbn;
2215 	int level;
2216 	ufs_lbn_t lbn;
2217 	long *countp;
2218 {
2219 	struct buf *bp;
2220 	ufs_daddr_t *bap;
2221 	ufs_daddr_t nb;
2222 	struct fs *fs;
2223 	struct worklist *wk;
2224 	struct indirdep *indirdep;
2225 	int i, lbnadd, nblocks;
2226 	int error, allerror = 0;
2227 
2228 	fs = ip->i_fs;
2229 	lbnadd = 1;
2230 	for (i = level; i > 0; i--)
2231 		lbnadd *= NINDIR(fs);
2232 	/*
2233 	 * Get buffer of block pointers to be freed. This routine is not
2234 	 * called until the zero'ed inode has been written, so it is safe
2235 	 * to free blocks as they are encountered. Because the inode has
2236 	 * been zero'ed, calls to bmap on these blocks will fail. So, we
2237 	 * have to use the on-disk address and the block device for the
2238 	 * filesystem to look them up. If the file was deleted before its
2239 	 * indirect blocks were all written to disk, the routine that set
2240 	 * us up (deallocate_dependencies) will have arranged to leave
2241 	 * a complete copy of the indirect block in memory for our use.
2242 	 * Otherwise we have to read the blocks in from the disk.
2243 	 */
2244 	ACQUIRE_LOCK(&lk);
2245 	if ((bp = incore(ip->i_devvp, dbn)) != NULL &&
2246 	    (wk = LIST_FIRST(&bp->b_dep)) != NULL) {
2247 		if (wk->wk_type != D_INDIRDEP ||
2248 		    (indirdep = WK_INDIRDEP(wk))->ir_savebp != bp ||
2249 		    (indirdep->ir_state & GOINGAWAY) == 0) {
2250 			FREE_LOCK(&lk);
2251 			panic("indir_trunc: lost indirdep");
2252 		}
2253 		WORKLIST_REMOVE(wk);
2254 		WORKITEM_FREE(indirdep, D_INDIRDEP);
2255 		if (LIST_FIRST(&bp->b_dep) != NULL) {
2256 			FREE_LOCK(&lk);
2257 			panic("indir_trunc: dangling dep");
2258 		}
2259 		FREE_LOCK(&lk);
2260 	} else {
2261 		FREE_LOCK(&lk);
2262 		error = bread(ip->i_devvp, dbn, (int)fs->fs_bsize, &bp);
2263 		if (error)
2264 			return (error);
2265 	}
2266 	/*
2267 	 * Recursively free indirect blocks.
2268 	 */
2269 	bap = (ufs_daddr_t *)bp->b_data;
2270 	nblocks = btodb(fs->fs_bsize);
2271 	for (i = NINDIR(fs) - 1; i >= 0; i--) {
2272 		if ((nb = bap[i]) == 0)
2273 			continue;
2274 		if (level != 0) {
2275 			if ((error = indir_trunc(ip, fsbtodb(fs, nb),
2276 			     level - 1, lbn + (i * lbnadd), countp)) != 0)
2277 				allerror = error;
2278 		}
2279 		ffs_blkfree(ip, nb, fs->fs_bsize);
2280 		*countp += nblocks;
2281 	}
2282 	bp->b_flags |= B_INVAL | B_NOCACHE;
2283 	brelse(bp);
2284 	return (allerror);
2285 }
2286 
2287 /*
2288  * Free an allocindir.
2289  * This routine must be called with splbio interrupts blocked.
2290  */
2291 static void
2292 free_allocindir(aip, inodedep)
2293 	struct allocindir *aip;
2294 	struct inodedep *inodedep;
2295 {
2296 	struct freefrag *freefrag;
2297 
2298 #ifdef DEBUG
2299 	if (lk.lkt_held == NOHOLDER)
2300 		panic("free_allocindir: lock not held");
2301 #endif
2302 	if ((aip->ai_state & DEPCOMPLETE) == 0)
2303 		LIST_REMOVE(aip, ai_deps);
2304 	if (aip->ai_state & ONWORKLIST)
2305 		WORKLIST_REMOVE(&aip->ai_list);
2306 	LIST_REMOVE(aip, ai_next);
2307 	if ((freefrag = aip->ai_freefrag) != NULL) {
2308 		if (inodedep == NULL)
2309 			add_to_worklist(&freefrag->ff_list);
2310 		else
2311 			WORKLIST_INSERT(&inodedep->id_bufwait,
2312 			    &freefrag->ff_list);
2313 	}
2314 	WORKITEM_FREE(aip, D_ALLOCINDIR);
2315 }
2316 
2317 /*
2318  * Directory entry addition dependencies.
2319  *
2320  * When adding a new directory entry, the inode (with its incremented link
2321  * count) must be written to disk before the directory entry's pointer to it.
2322  * Also, if the inode is newly allocated, the corresponding freemap must be
2323  * updated (on disk) before the directory entry's pointer. These requirements
2324  * are met via undo/redo on the directory entry's pointer, which consists
2325  * simply of the inode number.
2326  *
2327  * As directory entries are added and deleted, the free space within a
2328  * directory block can become fragmented.  The ufs filesystem will compact
2329  * a fragmented directory block to make space for a new entry. When this
2330  * occurs, the offsets of previously added entries change. Any "diradd"
2331  * dependency structures corresponding to these entries must be updated with
2332  * the new offsets.
2333  */
2334 
2335 /*
2336  * This routine is called after the in-memory inode's link
2337  * count has been incremented, but before the directory entry's
2338  * pointer to the inode has been set.
2339  */
2340 void
2341 softdep_setup_directory_add(bp, dp, diroffset, newinum, newdirbp)
2342 	struct buf *bp;		/* buffer containing directory block */
2343 	struct inode *dp;	/* inode for directory */
2344 	off_t diroffset;	/* offset of new entry in directory */
2345 	ino_t newinum;		/* inode referenced by new directory entry */
2346 	struct buf *newdirbp;	/* non-NULL => contents of new mkdir */
2347 {
2348 	int offset;		/* offset of new entry within directory block */
2349 	ufs_lbn_t lbn;		/* block in directory containing new entry */
2350 	struct fs *fs;
2351 	struct diradd *dap;
2352 	struct pagedep *pagedep;
2353 	struct inodedep *inodedep;
2354 	struct mkdir *mkdir1, *mkdir2;
2355 
2356 	/*
2357 	 * Whiteouts have no dependencies.
2358 	 */
2359 	if (newinum == WINO) {
2360 		if (newdirbp != NULL)
2361 			bdwrite(newdirbp);
2362 		return;
2363 	}
2364 
2365 	fs = dp->i_fs;
2366 	lbn = lblkno(fs, diroffset);
2367 	offset = blkoff(fs, diroffset);
2368 	MALLOC(dap, struct diradd *, sizeof(struct diradd), M_DIRADD,
2369 	    M_SOFTDEP_FLAGS);
2370 	bzero(dap, sizeof(struct diradd));
2371 	dap->da_list.wk_type = D_DIRADD;
2372 	dap->da_offset = offset;
2373 	dap->da_newinum = newinum;
2374 	dap->da_state = ATTACHED;
2375 	if (newdirbp == NULL) {
2376 		dap->da_state |= DEPCOMPLETE;
2377 		ACQUIRE_LOCK(&lk);
2378 	} else {
2379 		dap->da_state |= MKDIR_BODY | MKDIR_PARENT;
2380 		MALLOC(mkdir1, struct mkdir *, sizeof(struct mkdir), M_MKDIR,
2381 		    M_SOFTDEP_FLAGS);
2382 		mkdir1->md_list.wk_type = D_MKDIR;
2383 		mkdir1->md_state = MKDIR_BODY;
2384 		mkdir1->md_diradd = dap;
2385 		MALLOC(mkdir2, struct mkdir *, sizeof(struct mkdir), M_MKDIR,
2386 		    M_SOFTDEP_FLAGS);
2387 		mkdir2->md_list.wk_type = D_MKDIR;
2388 		mkdir2->md_state = MKDIR_PARENT;
2389 		mkdir2->md_diradd = dap;
2390 		/*
2391 		 * Dependency on "." and ".." being written to disk.
2392 		 */
2393 		mkdir1->md_buf = newdirbp;
2394 		ACQUIRE_LOCK(&lk);
2395 		LIST_INSERT_HEAD(&mkdirlisthd, mkdir1, md_mkdirs);
2396 		WORKLIST_INSERT(&newdirbp->b_dep, &mkdir1->md_list);
2397 		FREE_LOCK(&lk);
2398 		bdwrite(newdirbp);
2399 		/*
2400 		 * Dependency on link count increase for parent directory
2401 		 */
2402 		ACQUIRE_LOCK(&lk);
2403 		if (inodedep_lookup(dp->i_fs, dp->i_number, 0, &inodedep) == 0
2404 		    || (inodedep->id_state & ALLCOMPLETE) == ALLCOMPLETE) {
2405 			dap->da_state &= ~MKDIR_PARENT;
2406 			WORKITEM_FREE(mkdir2, D_MKDIR);
2407 		} else {
2408 			LIST_INSERT_HEAD(&mkdirlisthd, mkdir2, md_mkdirs);
2409 			WORKLIST_INSERT(&inodedep->id_bufwait,&mkdir2->md_list);
2410 		}
2411 	}
2412 	/*
2413 	 * Link into parent directory pagedep to await its being written.
2414 	 */
2415 	if (pagedep_lookup(dp, lbn, DEPALLOC, &pagedep) == 0)
2416 		WORKLIST_INSERT(&bp->b_dep, &pagedep->pd_list);
2417 	dap->da_pagedep = pagedep;
2418 	LIST_INSERT_HEAD(&pagedep->pd_diraddhd[DIRADDHASH(offset)], dap,
2419 	    da_pdlist);
2420 	/*
2421 	 * Link into its inodedep. Put it on the id_bufwait list if the inode
2422 	 * is not yet written. If it is written, do the post-inode write
2423 	 * processing to put it on the id_pendinghd list.
2424 	 */
2425 	(void) inodedep_lookup(fs, newinum, DEPALLOC, &inodedep);
2426 	if ((inodedep->id_state & ALLCOMPLETE) == ALLCOMPLETE)
2427 		diradd_inode_written(dap, inodedep);
2428 	else
2429 		WORKLIST_INSERT(&inodedep->id_bufwait, &dap->da_list);
2430 	FREE_LOCK(&lk);
2431 }
2432 
2433 /*
2434  * This procedure is called to change the offset of a directory
2435  * entry when compacting a directory block which must be owned
2436  * exclusively by the caller. Note that the actual entry movement
2437  * must be done in this procedure to ensure that no I/O completions
2438  * occur while the move is in progress.
2439  */
2440 void
2441 softdep_change_directoryentry_offset(dp, base, oldloc, newloc, entrysize)
2442 	struct inode *dp;	/* inode for directory */
2443 	caddr_t base;		/* address of dp->i_offset */
2444 	caddr_t oldloc;		/* address of old directory location */
2445 	caddr_t newloc;		/* address of new directory location */
2446 	int entrysize;		/* size of directory entry */
2447 {
2448 	int offset, oldoffset, newoffset;
2449 	struct pagedep *pagedep;
2450 	struct diradd *dap;
2451 	ufs_lbn_t lbn;
2452 
2453 	ACQUIRE_LOCK(&lk);
2454 	lbn = lblkno(dp->i_fs, dp->i_offset);
2455 	offset = blkoff(dp->i_fs, dp->i_offset);
2456 	if (pagedep_lookup(dp, lbn, 0, &pagedep) == 0)
2457 		goto done;
2458 	oldoffset = offset + (oldloc - base);
2459 	newoffset = offset + (newloc - base);
2460 
2461 	LIST_FOREACH(dap, &pagedep->pd_diraddhd[DIRADDHASH(oldoffset)], da_pdlist) {
2462 		if (dap->da_offset != oldoffset)
2463 			continue;
2464 		dap->da_offset = newoffset;
2465 		if (DIRADDHASH(newoffset) == DIRADDHASH(oldoffset))
2466 			break;
2467 		LIST_REMOVE(dap, da_pdlist);
2468 		LIST_INSERT_HEAD(&pagedep->pd_diraddhd[DIRADDHASH(newoffset)],
2469 		    dap, da_pdlist);
2470 		break;
2471 	}
2472 	if (dap == NULL) {
2473 
2474 		LIST_FOREACH(dap, &pagedep->pd_pendinghd, da_pdlist) {
2475 			if (dap->da_offset == oldoffset) {
2476 				dap->da_offset = newoffset;
2477 				break;
2478 			}
2479 		}
2480 	}
2481 done:
2482 	bcopy(oldloc, newloc, entrysize);
2483 	FREE_LOCK(&lk);
2484 }
2485 
2486 /*
2487  * Free a diradd dependency structure. This routine must be called
2488  * with splbio interrupts blocked.
2489  */
2490 static void
2491 free_diradd(dap)
2492 	struct diradd *dap;
2493 {
2494 	struct dirrem *dirrem;
2495 	struct pagedep *pagedep;
2496 	struct inodedep *inodedep;
2497 	struct mkdir *mkdir, *nextmd;
2498 
2499 #ifdef DEBUG
2500 	if (lk.lkt_held == NOHOLDER)
2501 		panic("free_diradd: lock not held");
2502 #endif
2503 	WORKLIST_REMOVE(&dap->da_list);
2504 	LIST_REMOVE(dap, da_pdlist);
2505 	if ((dap->da_state & DIRCHG) == 0) {
2506 		pagedep = dap->da_pagedep;
2507 	} else {
2508 		dirrem = dap->da_previous;
2509 		pagedep = dirrem->dm_pagedep;
2510 		dirrem->dm_dirinum = pagedep->pd_ino;
2511 		add_to_worklist(&dirrem->dm_list);
2512 	}
2513 	if (inodedep_lookup(VFSTOUFS(pagedep->pd_mnt)->um_fs, dap->da_newinum,
2514 	    0, &inodedep) != 0)
2515 		(void) free_inodedep(inodedep);
2516 	if ((dap->da_state & (MKDIR_PARENT | MKDIR_BODY)) != 0) {
2517 		for (mkdir = LIST_FIRST(&mkdirlisthd); mkdir; mkdir = nextmd) {
2518 			nextmd = LIST_NEXT(mkdir, md_mkdirs);
2519 			if (mkdir->md_diradd != dap)
2520 				continue;
2521 			dap->da_state &= ~mkdir->md_state;
2522 			WORKLIST_REMOVE(&mkdir->md_list);
2523 			LIST_REMOVE(mkdir, md_mkdirs);
2524 			WORKITEM_FREE(mkdir, D_MKDIR);
2525 		}
2526 		if ((dap->da_state & (MKDIR_PARENT | MKDIR_BODY)) != 0) {
2527 			FREE_LOCK(&lk);
2528 			panic("free_diradd: unfound ref");
2529 		}
2530 	}
2531 	WORKITEM_FREE(dap, D_DIRADD);
2532 }
2533 
2534 /*
2535  * Directory entry removal dependencies.
2536  *
2537  * When removing a directory entry, the entry's inode pointer must be
2538  * zero'ed on disk before the corresponding inode's link count is decremented
2539  * (possibly freeing the inode for re-use). This dependency is handled by
2540  * updating the directory entry but delaying the inode count reduction until
2541  * after the directory block has been written to disk. After this point, the
2542  * inode count can be decremented whenever it is convenient.
2543  */
2544 
2545 /*
2546  * This routine should be called immediately after removing
2547  * a directory entry.  The inode's link count should not be
2548  * decremented by the calling procedure -- the soft updates
2549  * code will do this task when it is safe.
2550  */
2551 void
2552 softdep_setup_remove(bp, dp, ip, isrmdir)
2553 	struct buf *bp;		/* buffer containing directory block */
2554 	struct inode *dp;	/* inode for the directory being modified */
2555 	struct inode *ip;	/* inode for directory entry being removed */
2556 	int isrmdir;		/* indicates if doing RMDIR */
2557 {
2558 	struct dirrem *dirrem, *prevdirrem;
2559 
2560 	/*
2561 	 * Allocate a new dirrem if appropriate and ACQUIRE_LOCK.
2562 	 */
2563 	dirrem = newdirrem(bp, dp, ip, isrmdir, &prevdirrem);
2564 
2565 	/*
2566 	 * If the COMPLETE flag is clear, then there were no active
2567 	 * entries and we want to roll back to a zeroed entry until
2568 	 * the new inode is committed to disk. If the COMPLETE flag is
2569 	 * set then we have deleted an entry that never made it to
2570 	 * disk. If the entry we deleted resulted from a name change,
2571 	 * then the old name still resides on disk. We cannot delete
2572 	 * its inode (returned to us in prevdirrem) until the zeroed
2573 	 * directory entry gets to disk. The new inode has never been
2574 	 * referenced on the disk, so can be deleted immediately.
2575 	 */
2576 	if ((dirrem->dm_state & COMPLETE) == 0) {
2577 		LIST_INSERT_HEAD(&dirrem->dm_pagedep->pd_dirremhd, dirrem,
2578 		    dm_next);
2579 		FREE_LOCK(&lk);
2580 	} else {
2581 		if (prevdirrem != NULL)
2582 			LIST_INSERT_HEAD(&dirrem->dm_pagedep->pd_dirremhd,
2583 			    prevdirrem, dm_next);
2584 		dirrem->dm_dirinum = dirrem->dm_pagedep->pd_ino;
2585 		FREE_LOCK(&lk);
2586 		handle_workitem_remove(dirrem);
2587 	}
2588 }
2589 
2590 /*
2591  * Allocate a new dirrem if appropriate and return it along with
2592  * its associated pagedep. Called without a lock, returns with lock.
2593  */
2594 static long num_dirrem;		/* number of dirrem allocated */
2595 static struct dirrem *
2596 newdirrem(bp, dp, ip, isrmdir, prevdirremp)
2597 	struct buf *bp;		/* buffer containing directory block */
2598 	struct inode *dp;	/* inode for the directory being modified */
2599 	struct inode *ip;	/* inode for directory entry being removed */
2600 	int isrmdir;		/* indicates if doing RMDIR */
2601 	struct dirrem **prevdirremp; /* previously referenced inode, if any */
2602 {
2603 	int offset;
2604 	ufs_lbn_t lbn;
2605 	struct diradd *dap;
2606 	struct dirrem *dirrem;
2607 	struct pagedep *pagedep;
2608 
2609 	/*
2610 	 * Whiteouts have no deletion dependencies.
2611 	 */
2612 	if (ip == NULL)
2613 		panic("newdirrem: whiteout");
2614 	/*
2615 	 * If we are over our limit, try to improve the situation.
2616 	 * Limiting the number of dirrem structures will also limit
2617 	 * the number of freefile and freeblks structures.
2618 	 */
2619 	if (num_dirrem > max_softdeps / 2 && speedup_syncer() == 0)
2620 		(void) request_cleanup(FLUSH_REMOVE, 0);
2621 	num_dirrem += 1;
2622 	MALLOC(dirrem, struct dirrem *, sizeof(struct dirrem),
2623 		M_DIRREM, M_SOFTDEP_FLAGS);
2624 	bzero(dirrem, sizeof(struct dirrem));
2625 	dirrem->dm_list.wk_type = D_DIRREM;
2626 	dirrem->dm_state = isrmdir ? RMDIR : 0;
2627 	dirrem->dm_mnt = ITOV(ip)->v_mount;
2628 	dirrem->dm_oldinum = ip->i_number;
2629 	*prevdirremp = NULL;
2630 
2631 	ACQUIRE_LOCK(&lk);
2632 	lbn = lblkno(dp->i_fs, dp->i_offset);
2633 	offset = blkoff(dp->i_fs, dp->i_offset);
2634 	if (pagedep_lookup(dp, lbn, DEPALLOC, &pagedep) == 0)
2635 		WORKLIST_INSERT(&bp->b_dep, &pagedep->pd_list);
2636 	dirrem->dm_pagedep = pagedep;
2637 	/*
2638 	 * Check for a diradd dependency for the same directory entry.
2639 	 * If present, then both dependencies become obsolete and can
2640 	 * be de-allocated. Check for an entry on both the pd_dirraddhd
2641 	 * list and the pd_pendinghd list.
2642 	 */
2643 
2644 	LIST_FOREACH(dap, &pagedep->pd_diraddhd[DIRADDHASH(offset)], da_pdlist)
2645 		if (dap->da_offset == offset)
2646 			break;
2647 	if (dap == NULL) {
2648 
2649 		LIST_FOREACH(dap, &pagedep->pd_pendinghd, da_pdlist)
2650 			if (dap->da_offset == offset)
2651 				break;
2652 		if (dap == NULL)
2653 			return (dirrem);
2654 	}
2655 	/*
2656 	 * Must be ATTACHED at this point.
2657 	 */
2658 	if ((dap->da_state & ATTACHED) == 0) {
2659 		FREE_LOCK(&lk);
2660 		panic("newdirrem: not ATTACHED");
2661 	}
2662 	if (dap->da_newinum != ip->i_number) {
2663 		FREE_LOCK(&lk);
2664 		panic("newdirrem: inum %"PRId64" should be %"PRId64,
2665 		    ip->i_number, dap->da_newinum);
2666 	}
2667 	/*
2668 	 * If we are deleting a changed name that never made it to disk,
2669 	 * then return the dirrem describing the previous inode (which
2670 	 * represents the inode currently referenced from this entry on disk).
2671 	 */
2672 	if ((dap->da_state & DIRCHG) != 0) {
2673 		*prevdirremp = dap->da_previous;
2674 		dap->da_state &= ~DIRCHG;
2675 		dap->da_pagedep = pagedep;
2676 	}
2677 	/*
2678 	 * We are deleting an entry that never made it to disk.
2679 	 * Mark it COMPLETE so we can delete its inode immediately.
2680 	 */
2681 	dirrem->dm_state |= COMPLETE;
2682 	free_diradd(dap);
2683 	return (dirrem);
2684 }
2685 
2686 /*
2687  * Directory entry change dependencies.
2688  *
2689  * Changing an existing directory entry requires that an add operation
2690  * be completed first followed by a deletion. The semantics for the addition
2691  * are identical to the description of adding a new entry above except
2692  * that the rollback is to the old inode number rather than zero. Once
2693  * the addition dependency is completed, the removal is done as described
2694  * in the removal routine above.
2695  */
2696 
2697 /*
2698  * This routine should be called immediately after changing
2699  * a directory entry.  The inode's link count should not be
2700  * decremented by the calling procedure -- the soft updates
2701  * code will perform this task when it is safe.
2702  */
2703 void
2704 softdep_setup_directory_change(bp, dp, ip, newinum, isrmdir)
2705 	struct buf *bp;		/* buffer containing directory block */
2706 	struct inode *dp;	/* inode for the directory being modified */
2707 	struct inode *ip;	/* inode for directory entry being removed */
2708 	ino_t newinum;		/* new inode number for changed entry */
2709 	int isrmdir;		/* indicates if doing RMDIR */
2710 {
2711 	int offset;
2712 	struct diradd *dap = NULL;
2713 	struct dirrem *dirrem, *prevdirrem;
2714 	struct pagedep *pagedep;
2715 	struct inodedep *inodedep;
2716 
2717 	offset = blkoff(dp->i_fs, dp->i_offset);
2718 
2719 	/*
2720 	 * Whiteouts do not need diradd dependencies.
2721 	 */
2722 	if (newinum != WINO) {
2723 		MALLOC(dap, struct diradd *, sizeof(struct diradd),
2724 		    M_DIRADD, M_SOFTDEP_FLAGS);
2725 		bzero(dap, sizeof(struct diradd));
2726 		dap->da_list.wk_type = D_DIRADD;
2727 		dap->da_state = DIRCHG | ATTACHED | DEPCOMPLETE;
2728 		dap->da_offset = offset;
2729 		dap->da_newinum = newinum;
2730 	}
2731 
2732 	/*
2733 	 * Allocate a new dirrem and ACQUIRE_LOCK.
2734 	 */
2735 	dirrem = newdirrem(bp, dp, ip, isrmdir, &prevdirrem);
2736 	pagedep = dirrem->dm_pagedep;
2737 	/*
2738 	 * The possible values for isrmdir:
2739 	 *	0 - non-directory file rename
2740 	 *	1 - directory rename within same directory
2741 	 *   inum - directory rename to new directory of given inode number
2742 	 * When renaming to a new directory, we are both deleting and
2743 	 * creating a new directory entry, so the link count on the new
2744 	 * directory should not change. Thus we do not need the followup
2745 	 * dirrem which is usually done in handle_workitem_remove. We set
2746 	 * the DIRCHG flag to tell handle_workitem_remove to skip the
2747 	 * followup dirrem.
2748 	 */
2749 	if (isrmdir > 1)
2750 		dirrem->dm_state |= DIRCHG;
2751 
2752 	/*
2753 	 * Whiteouts have no additional dependencies,
2754 	 * so just put the dirrem on the correct list.
2755 	 */
2756 	if (newinum == WINO) {
2757 		if ((dirrem->dm_state & COMPLETE) == 0) {
2758 			LIST_INSERT_HEAD(&pagedep->pd_dirremhd, dirrem,
2759 			    dm_next);
2760 		} else {
2761 			dirrem->dm_dirinum = pagedep->pd_ino;
2762 			add_to_worklist(&dirrem->dm_list);
2763 		}
2764 		FREE_LOCK(&lk);
2765 		return;
2766 	}
2767 
2768 	/*
2769 	 * If the COMPLETE flag is clear, then there were no active
2770 	 * entries and we want to roll back to the previous inode until
2771 	 * the new inode is committed to disk. If the COMPLETE flag is
2772 	 * set, then we have deleted an entry that never made it to disk.
2773 	 * If the entry we deleted resulted from a name change, then the old
2774 	 * inode reference still resides on disk. Any rollback that we do
2775 	 * needs to be to that old inode (returned to us in prevdirrem). If
2776 	 * the entry we deleted resulted from a create, then there is
2777 	 * no entry on the disk, so we want to roll back to zero rather
2778 	 * than the uncommitted inode. In either of the COMPLETE cases we
2779 	 * want to immediately free the unwritten and unreferenced inode.
2780 	 */
2781 	if ((dirrem->dm_state & COMPLETE) == 0) {
2782 		dap->da_previous = dirrem;
2783 	} else {
2784 		if (prevdirrem != NULL) {
2785 			dap->da_previous = prevdirrem;
2786 		} else {
2787 			dap->da_state &= ~DIRCHG;
2788 			dap->da_pagedep = pagedep;
2789 		}
2790 		dirrem->dm_dirinum = pagedep->pd_ino;
2791 		add_to_worklist(&dirrem->dm_list);
2792 	}
2793 	/*
2794 	 * Link into its inodedep. Put it on the id_bufwait list if the inode
2795 	 * is not yet written. If it is written, do the post-inode write
2796 	 * processing to put it on the id_pendinghd list.
2797 	 */
2798 	if (inodedep_lookup(dp->i_fs, newinum, DEPALLOC, &inodedep) == 0 ||
2799 	    (inodedep->id_state & ALLCOMPLETE) == ALLCOMPLETE) {
2800 		dap->da_state |= COMPLETE;
2801 		LIST_INSERT_HEAD(&pagedep->pd_pendinghd, dap, da_pdlist);
2802 		WORKLIST_INSERT(&inodedep->id_pendinghd, &dap->da_list);
2803 	} else {
2804 		LIST_INSERT_HEAD(&pagedep->pd_diraddhd[DIRADDHASH(offset)],
2805 		    dap, da_pdlist);
2806 		WORKLIST_INSERT(&inodedep->id_bufwait, &dap->da_list);
2807 	}
2808 	FREE_LOCK(&lk);
2809 }
2810 
2811 /*
2812  * Called whenever the link count on an inode is changed.
2813  * It creates an inode dependency so that the new reference(s)
2814  * to the inode cannot be committed to disk until the updated
2815  * inode has been written.
2816  */
2817 void
2818 softdep_change_linkcnt(ip)
2819 	struct inode *ip;	/* the inode with the increased link count */
2820 {
2821 	struct inodedep *inodedep;
2822 
2823 	ACQUIRE_LOCK(&lk);
2824 	(void) inodedep_lookup(ip->i_fs, ip->i_number, DEPALLOC, &inodedep);
2825 	if (ip->i_nlink < ip->i_effnlink) {
2826 		FREE_LOCK(&lk);
2827 		panic("softdep_change_linkcnt: bad delta");
2828 	}
2829 	inodedep->id_nlinkdelta = ip->i_nlink - ip->i_effnlink;
2830 	FREE_LOCK(&lk);
2831 }
2832 
2833 /*
2834  * This workitem decrements the inode's link count.
2835  * If the link count reaches zero, the file is removed.
2836  */
2837 static void
2838 handle_workitem_remove(dirrem)
2839 	struct dirrem *dirrem;
2840 {
2841 	struct thread *td = curthread;	/* XXX */
2842 	struct inodedep *inodedep;
2843 	struct vnode *vp;
2844 	struct inode *ip;
2845 	ino_t oldinum;
2846 	int error;
2847 
2848 	if ((error = VFS_VGET(dirrem->dm_mnt, dirrem->dm_oldinum, &vp)) != 0) {
2849 		softdep_error("handle_workitem_remove: vget", error);
2850 		return;
2851 	}
2852 	ip = VTOI(vp);
2853 	ACQUIRE_LOCK(&lk);
2854 	if ((inodedep_lookup(ip->i_fs, dirrem->dm_oldinum, 0, &inodedep)) == 0){
2855 		FREE_LOCK(&lk);
2856 		panic("handle_workitem_remove: lost inodedep");
2857 	}
2858 	/*
2859 	 * Normal file deletion.
2860 	 */
2861 	if ((dirrem->dm_state & RMDIR) == 0) {
2862 		ip->i_nlink--;
2863 		ip->i_flag |= IN_CHANGE;
2864 		if (ip->i_nlink < ip->i_effnlink) {
2865 			FREE_LOCK(&lk);
2866 			panic("handle_workitem_remove: bad file delta");
2867 		}
2868 		inodedep->id_nlinkdelta = ip->i_nlink - ip->i_effnlink;
2869 		FREE_LOCK(&lk);
2870 		vput(vp);
2871 		num_dirrem -= 1;
2872 		WORKITEM_FREE(dirrem, D_DIRREM);
2873 		return;
2874 	}
2875 	/*
2876 	 * Directory deletion. Decrement reference count for both the
2877 	 * just deleted parent directory entry and the reference for ".".
2878 	 * Next truncate the directory to length zero. When the
2879 	 * truncation completes, arrange to have the reference count on
2880 	 * the parent decremented to account for the loss of "..".
2881 	 */
2882 	ip->i_nlink -= 2;
2883 	ip->i_flag |= IN_CHANGE;
2884 	if (ip->i_nlink < ip->i_effnlink) {
2885 		FREE_LOCK(&lk);
2886 		panic("handle_workitem_remove: bad dir delta");
2887 	}
2888 	inodedep->id_nlinkdelta = ip->i_nlink - ip->i_effnlink;
2889 	FREE_LOCK(&lk);
2890 	if ((error = UFS_TRUNCATE(vp, (off_t)0, 0, proc0.p_ucred, td)) != 0)
2891 		softdep_error("handle_workitem_remove: truncate", error);
2892 	/*
2893 	 * Rename a directory to a new parent. Since, we are both deleting
2894 	 * and creating a new directory entry, the link count on the new
2895 	 * directory should not change. Thus we skip the followup dirrem.
2896 	 */
2897 	if (dirrem->dm_state & DIRCHG) {
2898 		vput(vp);
2899 		num_dirrem -= 1;
2900 		WORKITEM_FREE(dirrem, D_DIRREM);
2901 		return;
2902 	}
2903 	/*
2904 	 * If the inodedep does not exist, then the zero'ed inode has
2905 	 * been written to disk. If the allocated inode has never been
2906 	 * written to disk, then the on-disk inode is zero'ed. In either
2907 	 * case we can remove the file immediately.
2908 	 */
2909 	ACQUIRE_LOCK(&lk);
2910 	dirrem->dm_state = 0;
2911 	oldinum = dirrem->dm_oldinum;
2912 	dirrem->dm_oldinum = dirrem->dm_dirinum;
2913 	if (inodedep_lookup(ip->i_fs, oldinum, 0, &inodedep) == 0 ||
2914 	    check_inode_unwritten(inodedep)) {
2915 		FREE_LOCK(&lk);
2916 		vput(vp);
2917 		handle_workitem_remove(dirrem);
2918 		return;
2919 	}
2920 	WORKLIST_INSERT(&inodedep->id_inowait, &dirrem->dm_list);
2921 	FREE_LOCK(&lk);
2922 	vput(vp);
2923 }
2924 
2925 /*
2926  * Inode de-allocation dependencies.
2927  *
2928  * When an inode's link count is reduced to zero, it can be de-allocated. We
2929  * found it convenient to postpone de-allocation until after the inode is
2930  * written to disk with its new link count (zero).  At this point, all of the
2931  * on-disk inode's block pointers are nullified and, with careful dependency
2932  * list ordering, all dependencies related to the inode will be satisfied and
2933  * the corresponding dependency structures de-allocated.  So, if/when the
2934  * inode is reused, there will be no mixing of old dependencies with new
2935  * ones.  This artificial dependency is set up by the block de-allocation
2936  * procedure above (softdep_setup_freeblocks) and completed by the
2937  * following procedure.
2938  */
2939 static void
2940 handle_workitem_freefile(freefile)
2941 	struct freefile *freefile;
2942 {
2943 	struct vnode vp;
2944 	struct inode tip;
2945 	struct inodedep *idp;
2946 	int error;
2947 
2948 #ifdef DEBUG
2949 	ACQUIRE_LOCK(&lk);
2950 	error = inodedep_lookup(freefile->fx_fs, freefile->fx_oldinum, 0, &idp);
2951 	FREE_LOCK(&lk);
2952 	if (error)
2953 		panic("handle_workitem_freefile: inodedep survived");
2954 #endif
2955 	tip.i_devvp = freefile->fx_devvp;
2956 	tip.i_dev = freefile->fx_devvp->v_rdev;
2957 	tip.i_fs = freefile->fx_fs;
2958 	vp.v_data = &tip;
2959 	if ((error = ffs_freefile(&vp, freefile->fx_oldinum, freefile->fx_mode)) != 0)
2960 		softdep_error("handle_workitem_freefile", error);
2961 	WORKITEM_FREE(freefile, D_FREEFILE);
2962 }
2963 
2964 /*
2965  * Disk writes.
2966  *
2967  * The dependency structures constructed above are most actively used when file
2968  * system blocks are written to disk.  No constraints are placed on when a
2969  * block can be written, but unsatisfied update dependencies are made safe by
2970  * modifying (or replacing) the source memory for the duration of the disk
2971  * write.  When the disk write completes, the memory block is again brought
2972  * up-to-date.
2973  *
2974  * In-core inode structure reclamation.
2975  *
2976  * Because there are a finite number of "in-core" inode structures, they are
2977  * reused regularly.  By transferring all inode-related dependencies to the
2978  * in-memory inode block and indexing them separately (via "inodedep"s), we
2979  * can allow "in-core" inode structures to be reused at any time and avoid
2980  * any increase in contention.
2981  *
2982  * Called just before entering the device driver to initiate a new disk I/O.
2983  * The buffer must be locked, thus, no I/O completion operations can occur
2984  * while we are manipulating its associated dependencies.
2985  */
2986 static void
2987 softdep_disk_io_initiation(bp)
2988 	struct buf *bp;		/* structure describing disk write to occur */
2989 {
2990 	struct worklist *wk, *nextwk;
2991 	struct indirdep *indirdep;
2992 
2993 	/*
2994 	 * We only care about write operations. There should never
2995 	 * be dependencies for reads.
2996 	 */
2997 	if (bp->b_flags & B_READ)
2998 		panic("softdep_disk_io_initiation: read");
2999 	/*
3000 	 * Do any necessary pre-I/O processing.
3001 	 */
3002 	for (wk = LIST_FIRST(&bp->b_dep); wk; wk = nextwk) {
3003 		nextwk = LIST_NEXT(wk, wk_list);
3004 		switch (wk->wk_type) {
3005 
3006 		case D_PAGEDEP:
3007 			initiate_write_filepage(WK_PAGEDEP(wk), bp);
3008 			continue;
3009 
3010 		case D_INODEDEP:
3011 			initiate_write_inodeblock(WK_INODEDEP(wk), bp);
3012 			continue;
3013 
3014 		case D_INDIRDEP:
3015 			indirdep = WK_INDIRDEP(wk);
3016 			if (indirdep->ir_state & GOINGAWAY)
3017 				panic("disk_io_initiation: indirdep gone");
3018 			/*
3019 			 * If there are no remaining dependencies, this
3020 			 * will be writing the real pointers, so the
3021 			 * dependency can be freed.
3022 			 */
3023 			if (LIST_FIRST(&indirdep->ir_deplisthd) == NULL) {
3024 				indirdep->ir_savebp->b_flags |= B_INVAL | B_NOCACHE;
3025 				brelse(indirdep->ir_savebp);
3026 				/* inline expand WORKLIST_REMOVE(wk); */
3027 				wk->wk_state &= ~ONWORKLIST;
3028 				LIST_REMOVE(wk, wk_list);
3029 				WORKITEM_FREE(indirdep, D_INDIRDEP);
3030 				continue;
3031 			}
3032 			/*
3033 			 * Replace up-to-date version with safe version.
3034 			 */
3035 			MALLOC(indirdep->ir_saveddata, caddr_t, bp->b_bcount,
3036 			    M_INDIRDEP, M_SOFTDEP_FLAGS);
3037 			ACQUIRE_LOCK(&lk);
3038 			indirdep->ir_state &= ~ATTACHED;
3039 			indirdep->ir_state |= UNDONE;
3040 			bcopy(bp->b_data, indirdep->ir_saveddata, bp->b_bcount);
3041 			bcopy(indirdep->ir_savebp->b_data, bp->b_data,
3042 			    bp->b_bcount);
3043 			FREE_LOCK(&lk);
3044 			continue;
3045 
3046 		case D_MKDIR:
3047 		case D_BMSAFEMAP:
3048 		case D_ALLOCDIRECT:
3049 		case D_ALLOCINDIR:
3050 			continue;
3051 
3052 		default:
3053 			panic("handle_disk_io_initiation: Unexpected type %s",
3054 			    TYPENAME(wk->wk_type));
3055 			/* NOTREACHED */
3056 		}
3057 	}
3058 }
3059 
3060 /*
3061  * Called from within the procedure above to deal with unsatisfied
3062  * allocation dependencies in a directory. The buffer must be locked,
3063  * thus, no I/O completion operations can occur while we are
3064  * manipulating its associated dependencies.
3065  */
3066 static void
3067 initiate_write_filepage(pagedep, bp)
3068 	struct pagedep *pagedep;
3069 	struct buf *bp;
3070 {
3071 	struct diradd *dap;
3072 	struct direct *ep;
3073 	int i;
3074 
3075 	if (pagedep->pd_state & IOSTARTED) {
3076 		/*
3077 		 * This can only happen if there is a driver that does not
3078 		 * understand chaining. Here biodone will reissue the call
3079 		 * to strategy for the incomplete buffers.
3080 		 */
3081 		printf("initiate_write_filepage: already started\n");
3082 		return;
3083 	}
3084 	pagedep->pd_state |= IOSTARTED;
3085 	ACQUIRE_LOCK(&lk);
3086 	for (i = 0; i < DAHASHSZ; i++) {
3087 		LIST_FOREACH(dap, &pagedep->pd_diraddhd[i], da_pdlist) {
3088 			ep = (struct direct *)
3089 			    ((char *)bp->b_data + dap->da_offset);
3090 			if (ep->d_ino != dap->da_newinum) {
3091 				FREE_LOCK(&lk);
3092 				panic("%s: dir inum %d != new %"PRId64,
3093 				    "initiate_write_filepage",
3094 				    ep->d_ino, dap->da_newinum);
3095 			}
3096 			if (dap->da_state & DIRCHG)
3097 				ep->d_ino = dap->da_previous->dm_oldinum;
3098 			else
3099 				ep->d_ino = 0;
3100 			dap->da_state &= ~ATTACHED;
3101 			dap->da_state |= UNDONE;
3102 		}
3103 	}
3104 	FREE_LOCK(&lk);
3105 }
3106 
3107 /*
3108  * Called from within the procedure above to deal with unsatisfied
3109  * allocation dependencies in an inodeblock. The buffer must be
3110  * locked, thus, no I/O completion operations can occur while we
3111  * are manipulating its associated dependencies.
3112  */
3113 static void
3114 initiate_write_inodeblock(inodedep, bp)
3115 	struct inodedep *inodedep;
3116 	struct buf *bp;			/* The inode block */
3117 {
3118 	struct allocdirect *adp, *lastadp;
3119 	struct dinode *dp;
3120 	struct fs *fs;
3121 	ufs_lbn_t prevlbn = 0;
3122 	int i, deplist;
3123 
3124 	if (inodedep->id_state & IOSTARTED)
3125 		panic("initiate_write_inodeblock: already started");
3126 	inodedep->id_state |= IOSTARTED;
3127 	fs = inodedep->id_fs;
3128 	dp = (struct dinode *)bp->b_data +
3129 	    ino_to_fsbo(fs, inodedep->id_ino);
3130 	/*
3131 	 * If the bitmap is not yet written, then the allocated
3132 	 * inode cannot be written to disk.
3133 	 */
3134 	if ((inodedep->id_state & DEPCOMPLETE) == 0) {
3135 		if (inodedep->id_savedino != NULL)
3136 			panic("initiate_write_inodeblock: already doing I/O");
3137 		MALLOC(inodedep->id_savedino, struct dinode *,
3138 		    sizeof(struct dinode), M_INODEDEP, M_SOFTDEP_FLAGS);
3139 		*inodedep->id_savedino = *dp;
3140 		bzero((caddr_t)dp, sizeof(struct dinode));
3141 		return;
3142 	}
3143 	/*
3144 	 * If no dependencies, then there is nothing to roll back.
3145 	 */
3146 	inodedep->id_savedsize = dp->di_size;
3147 	if (TAILQ_FIRST(&inodedep->id_inoupdt) == NULL)
3148 		return;
3149 	/*
3150 	 * Set the dependencies to busy.
3151 	 */
3152 	ACQUIRE_LOCK(&lk);
3153 	for (deplist = 0, adp = TAILQ_FIRST(&inodedep->id_inoupdt); adp;
3154 	     adp = TAILQ_NEXT(adp, ad_next)) {
3155 #ifdef DIAGNOSTIC
3156 		if (deplist != 0 && prevlbn >= adp->ad_lbn) {
3157 			FREE_LOCK(&lk);
3158 			panic("softdep_write_inodeblock: lbn order");
3159 		}
3160 		prevlbn = adp->ad_lbn;
3161 		if (adp->ad_lbn < NDADDR &&
3162 		    dp->di_db[adp->ad_lbn] != adp->ad_newblkno) {
3163 			FREE_LOCK(&lk);
3164 			panic("%s: direct pointer #%ld mismatch %d != %d",
3165 			    "softdep_write_inodeblock", adp->ad_lbn,
3166 			    dp->di_db[adp->ad_lbn], adp->ad_newblkno);
3167 		}
3168 		if (adp->ad_lbn >= NDADDR &&
3169 		    dp->di_ib[adp->ad_lbn - NDADDR] != adp->ad_newblkno) {
3170 			FREE_LOCK(&lk);
3171 			panic("%s: indirect pointer #%ld mismatch %d != %d",
3172 			    "softdep_write_inodeblock", adp->ad_lbn - NDADDR,
3173 			    dp->di_ib[adp->ad_lbn - NDADDR], adp->ad_newblkno);
3174 		}
3175 		deplist |= 1 << adp->ad_lbn;
3176 		if ((adp->ad_state & ATTACHED) == 0) {
3177 			FREE_LOCK(&lk);
3178 			panic("softdep_write_inodeblock: Unknown state 0x%x",
3179 			    adp->ad_state);
3180 		}
3181 #endif /* DIAGNOSTIC */
3182 		adp->ad_state &= ~ATTACHED;
3183 		adp->ad_state |= UNDONE;
3184 	}
3185 	/*
3186 	 * The on-disk inode cannot claim to be any larger than the last
3187 	 * fragment that has been written. Otherwise, the on-disk inode
3188 	 * might have fragments that were not the last block in the file
3189 	 * which would corrupt the filesystem.
3190 	 */
3191 	for (lastadp = NULL, adp = TAILQ_FIRST(&inodedep->id_inoupdt); adp;
3192 	     lastadp = adp, adp = TAILQ_NEXT(adp, ad_next)) {
3193 		if (adp->ad_lbn >= NDADDR)
3194 			break;
3195 		dp->di_db[adp->ad_lbn] = adp->ad_oldblkno;
3196 		/* keep going until hitting a rollback to a frag */
3197 		if (adp->ad_oldsize == 0 || adp->ad_oldsize == fs->fs_bsize)
3198 			continue;
3199 		dp->di_size = fs->fs_bsize * adp->ad_lbn + adp->ad_oldsize;
3200 		for (i = adp->ad_lbn + 1; i < NDADDR; i++) {
3201 #ifdef DIAGNOSTIC
3202 			if (dp->di_db[i] != 0 && (deplist & (1 << i)) == 0) {
3203 				FREE_LOCK(&lk);
3204 				panic("softdep_write_inodeblock: lost dep1");
3205 			}
3206 #endif /* DIAGNOSTIC */
3207 			dp->di_db[i] = 0;
3208 		}
3209 		for (i = 0; i < NIADDR; i++) {
3210 #ifdef DIAGNOSTIC
3211 			if (dp->di_ib[i] != 0 &&
3212 			    (deplist & ((1 << NDADDR) << i)) == 0) {
3213 				FREE_LOCK(&lk);
3214 				panic("softdep_write_inodeblock: lost dep2");
3215 			}
3216 #endif /* DIAGNOSTIC */
3217 			dp->di_ib[i] = 0;
3218 		}
3219 		FREE_LOCK(&lk);
3220 		return;
3221 	}
3222 	/*
3223 	 * If we have zero'ed out the last allocated block of the file,
3224 	 * roll back the size to the last currently allocated block.
3225 	 * We know that this last allocated block is a full-sized as
3226 	 * we already checked for fragments in the loop above.
3227 	 */
3228 	if (lastadp != NULL &&
3229 	    dp->di_size <= (lastadp->ad_lbn + 1) * fs->fs_bsize) {
3230 		for (i = lastadp->ad_lbn; i >= 0; i--)
3231 			if (dp->di_db[i] != 0)
3232 				break;
3233 		dp->di_size = (i + 1) * fs->fs_bsize;
3234 	}
3235 	/*
3236 	 * The only dependencies are for indirect blocks.
3237 	 *
3238 	 * The file size for indirect block additions is not guaranteed.
3239 	 * Such a guarantee would be non-trivial to achieve. The conventional
3240 	 * synchronous write implementation also does not make this guarantee.
3241 	 * Fsck should catch and fix discrepancies. Arguably, the file size
3242 	 * can be over-estimated without destroying integrity when the file
3243 	 * moves into the indirect blocks (i.e., is large). If we want to
3244 	 * postpone fsck, we are stuck with this argument.
3245 	 */
3246 	for (; adp; adp = TAILQ_NEXT(adp, ad_next))
3247 		dp->di_ib[adp->ad_lbn - NDADDR] = 0;
3248 	FREE_LOCK(&lk);
3249 }
3250 
3251 /*
3252  * This routine is called during the completion interrupt
3253  * service routine for a disk write (from the procedure called
3254  * by the device driver to inform the filesystem caches of
3255  * a request completion).  It should be called early in this
3256  * procedure, before the block is made available to other
3257  * processes or other routines are called.
3258  */
3259 static void
3260 softdep_disk_write_complete(bp)
3261 	struct buf *bp;		/* describes the completed disk write */
3262 {
3263 	struct worklist *wk;
3264 	struct workhead reattach;
3265 	struct newblk *newblk;
3266 	struct allocindir *aip;
3267 	struct allocdirect *adp;
3268 	struct indirdep *indirdep;
3269 	struct inodedep *inodedep;
3270 	struct bmsafemap *bmsafemap;
3271 
3272 #ifdef DEBUG
3273 	if (lk.lkt_held != NOHOLDER)
3274 		panic("softdep_disk_write_complete: lock is held");
3275 	lk.lkt_held = SPECIAL_FLAG;
3276 #endif
3277 	LIST_INIT(&reattach);
3278 	while ((wk = LIST_FIRST(&bp->b_dep)) != NULL) {
3279 		WORKLIST_REMOVE(wk);
3280 		switch (wk->wk_type) {
3281 
3282 		case D_PAGEDEP:
3283 			if (handle_written_filepage(WK_PAGEDEP(wk), bp))
3284 				WORKLIST_INSERT(&reattach, wk);
3285 			continue;
3286 
3287 		case D_INODEDEP:
3288 			if (handle_written_inodeblock(WK_INODEDEP(wk), bp))
3289 				WORKLIST_INSERT(&reattach, wk);
3290 			continue;
3291 
3292 		case D_BMSAFEMAP:
3293 			bmsafemap = WK_BMSAFEMAP(wk);
3294 			while ((newblk = LIST_FIRST(&bmsafemap->sm_newblkhd))) {
3295 				newblk->nb_state |= DEPCOMPLETE;
3296 				newblk->nb_bmsafemap = NULL;
3297 				LIST_REMOVE(newblk, nb_deps);
3298 			}
3299 			while ((adp =
3300 			   LIST_FIRST(&bmsafemap->sm_allocdirecthd))) {
3301 				adp->ad_state |= DEPCOMPLETE;
3302 				adp->ad_buf = NULL;
3303 				LIST_REMOVE(adp, ad_deps);
3304 				handle_allocdirect_partdone(adp);
3305 			}
3306 			while ((aip =
3307 			    LIST_FIRST(&bmsafemap->sm_allocindirhd))) {
3308 				aip->ai_state |= DEPCOMPLETE;
3309 				aip->ai_buf = NULL;
3310 				LIST_REMOVE(aip, ai_deps);
3311 				handle_allocindir_partdone(aip);
3312 			}
3313 			while ((inodedep =
3314 			     LIST_FIRST(&bmsafemap->sm_inodedephd)) != NULL) {
3315 				inodedep->id_state |= DEPCOMPLETE;
3316 				LIST_REMOVE(inodedep, id_deps);
3317 				inodedep->id_buf = NULL;
3318 			}
3319 			WORKITEM_FREE(bmsafemap, D_BMSAFEMAP);
3320 			continue;
3321 
3322 		case D_MKDIR:
3323 			handle_written_mkdir(WK_MKDIR(wk), MKDIR_BODY);
3324 			continue;
3325 
3326 		case D_ALLOCDIRECT:
3327 			adp = WK_ALLOCDIRECT(wk);
3328 			adp->ad_state |= COMPLETE;
3329 			handle_allocdirect_partdone(adp);
3330 			continue;
3331 
3332 		case D_ALLOCINDIR:
3333 			aip = WK_ALLOCINDIR(wk);
3334 			aip->ai_state |= COMPLETE;
3335 			handle_allocindir_partdone(aip);
3336 			continue;
3337 
3338 		case D_INDIRDEP:
3339 			indirdep = WK_INDIRDEP(wk);
3340 			if (indirdep->ir_state & GOINGAWAY) {
3341 				lk.lkt_held = NOHOLDER;
3342 				panic("disk_write_complete: indirdep gone");
3343 			}
3344 			bcopy(indirdep->ir_saveddata, bp->b_data, bp->b_bcount);
3345 			FREE(indirdep->ir_saveddata, M_INDIRDEP);
3346 			indirdep->ir_saveddata = 0;
3347 			indirdep->ir_state &= ~UNDONE;
3348 			indirdep->ir_state |= ATTACHED;
3349 			while ((aip = LIST_FIRST(&indirdep->ir_donehd)) != 0) {
3350 				handle_allocindir_partdone(aip);
3351 				if (aip == LIST_FIRST(&indirdep->ir_donehd)) {
3352 					lk.lkt_held = NOHOLDER;
3353 					panic("disk_write_complete: not gone");
3354 				}
3355 			}
3356 			WORKLIST_INSERT(&reattach, wk);
3357 			if ((bp->b_flags & B_DELWRI) == 0)
3358 				stat_indir_blk_ptrs++;
3359 			bdirty(bp);
3360 			continue;
3361 
3362 		default:
3363 			lk.lkt_held = NOHOLDER;
3364 			panic("handle_disk_write_complete: Unknown type %s",
3365 			    TYPENAME(wk->wk_type));
3366 			/* NOTREACHED */
3367 		}
3368 	}
3369 	/*
3370 	 * Reattach any requests that must be redone.
3371 	 */
3372 	while ((wk = LIST_FIRST(&reattach)) != NULL) {
3373 		WORKLIST_REMOVE(wk);
3374 		WORKLIST_INSERT(&bp->b_dep, wk);
3375 	}
3376 #ifdef DEBUG
3377 	if (lk.lkt_held != SPECIAL_FLAG)
3378 		panic("softdep_disk_write_complete: lock lost");
3379 	lk.lkt_held = NOHOLDER;
3380 #endif
3381 }
3382 
3383 /*
3384  * Called from within softdep_disk_write_complete above. Note that
3385  * this routine is always called from interrupt level with further
3386  * splbio interrupts blocked.
3387  */
3388 static void
3389 handle_allocdirect_partdone(adp)
3390 	struct allocdirect *adp;	/* the completed allocdirect */
3391 {
3392 	struct allocdirect *listadp;
3393 	struct inodedep *inodedep;
3394 	long bsize;
3395 
3396 	if ((adp->ad_state & ALLCOMPLETE) != ALLCOMPLETE)
3397 		return;
3398 	if (adp->ad_buf != NULL) {
3399 		lk.lkt_held = NOHOLDER;
3400 		panic("handle_allocdirect_partdone: dangling dep");
3401 	}
3402 	/*
3403 	 * The on-disk inode cannot claim to be any larger than the last
3404 	 * fragment that has been written. Otherwise, the on-disk inode
3405 	 * might have fragments that were not the last block in the file
3406 	 * which would corrupt the filesystem. Thus, we cannot free any
3407 	 * allocdirects after one whose ad_oldblkno claims a fragment as
3408 	 * these blocks must be rolled back to zero before writing the inode.
3409 	 * We check the currently active set of allocdirects in id_inoupdt.
3410 	 */
3411 	inodedep = adp->ad_inodedep;
3412 	bsize = inodedep->id_fs->fs_bsize;
3413 	TAILQ_FOREACH(listadp, &inodedep->id_inoupdt, ad_next) {
3414 		/* found our block */
3415 		if (listadp == adp)
3416 			break;
3417 		/* continue if ad_oldlbn is not a fragment */
3418 		if (listadp->ad_oldsize == 0 ||
3419 		    listadp->ad_oldsize == bsize)
3420 			continue;
3421 		/* hit a fragment */
3422 		return;
3423 	}
3424 	/*
3425 	 * If we have reached the end of the current list without
3426 	 * finding the just finished dependency, then it must be
3427 	 * on the future dependency list. Future dependencies cannot
3428 	 * be freed until they are moved to the current list.
3429 	 */
3430 	if (listadp == NULL) {
3431 #ifdef DEBUG
3432 		TAILQ_FOREACH(listadp, &inodedep->id_newinoupdt, ad_next)
3433 			/* found our block */
3434 			if (listadp == adp)
3435 				break;
3436 		if (listadp == NULL) {
3437 			lk.lkt_held = NOHOLDER;
3438 			panic("handle_allocdirect_partdone: lost dep");
3439 		}
3440 #endif /* DEBUG */
3441 		return;
3442 	}
3443 	/*
3444 	 * If we have found the just finished dependency, then free
3445 	 * it along with anything that follows it that is complete.
3446 	 */
3447 	for (; adp; adp = listadp) {
3448 		listadp = TAILQ_NEXT(adp, ad_next);
3449 		if ((adp->ad_state & ALLCOMPLETE) != ALLCOMPLETE)
3450 			return;
3451 		free_allocdirect(&inodedep->id_inoupdt, adp, 1);
3452 	}
3453 }
3454 
3455 /*
3456  * Called from within softdep_disk_write_complete above. Note that
3457  * this routine is always called from interrupt level with further
3458  * splbio interrupts blocked.
3459  */
3460 static void
3461 handle_allocindir_partdone(aip)
3462 	struct allocindir *aip;		/* the completed allocindir */
3463 {
3464 	struct indirdep *indirdep;
3465 
3466 	if ((aip->ai_state & ALLCOMPLETE) != ALLCOMPLETE)
3467 		return;
3468 	if (aip->ai_buf != NULL) {
3469 		lk.lkt_held = NOHOLDER;
3470 		panic("handle_allocindir_partdone: dangling dependency");
3471 	}
3472 	indirdep = aip->ai_indirdep;
3473 	if (indirdep->ir_state & UNDONE) {
3474 		LIST_REMOVE(aip, ai_next);
3475 		LIST_INSERT_HEAD(&indirdep->ir_donehd, aip, ai_next);
3476 		return;
3477 	}
3478 	((ufs_daddr_t *)indirdep->ir_savebp->b_data)[aip->ai_offset] =
3479 	    aip->ai_newblkno;
3480 	LIST_REMOVE(aip, ai_next);
3481 	if (aip->ai_freefrag != NULL)
3482 		add_to_worklist(&aip->ai_freefrag->ff_list);
3483 	WORKITEM_FREE(aip, D_ALLOCINDIR);
3484 }
3485 
3486 /*
3487  * Called from within softdep_disk_write_complete above to restore
3488  * in-memory inode block contents to their most up-to-date state. Note
3489  * that this routine is always called from interrupt level with further
3490  * splbio interrupts blocked.
3491  */
3492 static int
3493 handle_written_inodeblock(inodedep, bp)
3494 	struct inodedep *inodedep;
3495 	struct buf *bp;		/* buffer containing the inode block */
3496 {
3497 	struct worklist *wk, *filefree;
3498 	struct allocdirect *adp, *nextadp;
3499 	struct dinode *dp;
3500 	int hadchanges;
3501 
3502 	if ((inodedep->id_state & IOSTARTED) == 0) {
3503 		lk.lkt_held = NOHOLDER;
3504 		panic("handle_written_inodeblock: not started");
3505 	}
3506 	inodedep->id_state &= ~IOSTARTED;
3507 	inodedep->id_state |= COMPLETE;
3508 	dp = (struct dinode *)bp->b_data +
3509 	    ino_to_fsbo(inodedep->id_fs, inodedep->id_ino);
3510 	/*
3511 	 * If we had to rollback the inode allocation because of
3512 	 * bitmaps being incomplete, then simply restore it.
3513 	 * Keep the block dirty so that it will not be reclaimed until
3514 	 * all associated dependencies have been cleared and the
3515 	 * corresponding updates written to disk.
3516 	 */
3517 	if (inodedep->id_savedino != NULL) {
3518 		*dp = *inodedep->id_savedino;
3519 		FREE(inodedep->id_savedino, M_INODEDEP);
3520 		inodedep->id_savedino = NULL;
3521 		if ((bp->b_flags & B_DELWRI) == 0)
3522 			stat_inode_bitmap++;
3523 		bdirty(bp);
3524 		return (1);
3525 	}
3526 	/*
3527 	 * Roll forward anything that had to be rolled back before
3528 	 * the inode could be updated.
3529 	 */
3530 	hadchanges = 0;
3531 	for (adp = TAILQ_FIRST(&inodedep->id_inoupdt); adp; adp = nextadp) {
3532 		nextadp = TAILQ_NEXT(adp, ad_next);
3533 		if (adp->ad_state & ATTACHED) {
3534 			lk.lkt_held = NOHOLDER;
3535 			panic("handle_written_inodeblock: new entry");
3536 		}
3537 		if (adp->ad_lbn < NDADDR) {
3538 			if (dp->di_db[adp->ad_lbn] != adp->ad_oldblkno) {
3539 				lk.lkt_held = NOHOLDER;
3540 				panic("%s: %s #%ld mismatch %d != %d",
3541 				    "handle_written_inodeblock",
3542 				    "direct pointer", adp->ad_lbn,
3543 				    dp->di_db[adp->ad_lbn], adp->ad_oldblkno);
3544 			}
3545 			dp->di_db[adp->ad_lbn] = adp->ad_newblkno;
3546 		} else {
3547 			if (dp->di_ib[adp->ad_lbn - NDADDR] != 0) {
3548 				lk.lkt_held = NOHOLDER;
3549 				panic("%s: %s #%ld allocated as %d",
3550 				    "handle_written_inodeblock",
3551 				    "indirect pointer", adp->ad_lbn - NDADDR,
3552 				    dp->di_ib[adp->ad_lbn - NDADDR]);
3553 			}
3554 			dp->di_ib[adp->ad_lbn - NDADDR] = adp->ad_newblkno;
3555 		}
3556 		adp->ad_state &= ~UNDONE;
3557 		adp->ad_state |= ATTACHED;
3558 		hadchanges = 1;
3559 	}
3560 	if (hadchanges && (bp->b_flags & B_DELWRI) == 0)
3561 		stat_direct_blk_ptrs++;
3562 	/*
3563 	 * Reset the file size to its most up-to-date value.
3564 	 */
3565 	if (inodedep->id_savedsize == -1) {
3566 		lk.lkt_held = NOHOLDER;
3567 		panic("handle_written_inodeblock: bad size");
3568 	}
3569 	if (dp->di_size != inodedep->id_savedsize) {
3570 		dp->di_size = inodedep->id_savedsize;
3571 		hadchanges = 1;
3572 	}
3573 	inodedep->id_savedsize = -1;
3574 	/*
3575 	 * If there were any rollbacks in the inode block, then it must be
3576 	 * marked dirty so that its will eventually get written back in
3577 	 * its correct form.
3578 	 */
3579 	if (hadchanges)
3580 		bdirty(bp);
3581 	/*
3582 	 * Process any allocdirects that completed during the update.
3583 	 */
3584 	if ((adp = TAILQ_FIRST(&inodedep->id_inoupdt)) != NULL)
3585 		handle_allocdirect_partdone(adp);
3586 	/*
3587 	 * Process deallocations that were held pending until the
3588 	 * inode had been written to disk. Freeing of the inode
3589 	 * is delayed until after all blocks have been freed to
3590 	 * avoid creation of new <vfsid, inum, lbn> triples
3591 	 * before the old ones have been deleted.
3592 	 */
3593 	filefree = NULL;
3594 	while ((wk = LIST_FIRST(&inodedep->id_bufwait)) != NULL) {
3595 		WORKLIST_REMOVE(wk);
3596 		switch (wk->wk_type) {
3597 
3598 		case D_FREEFILE:
3599 			/*
3600 			 * We defer adding filefree to the worklist until
3601 			 * all other additions have been made to ensure
3602 			 * that it will be done after all the old blocks
3603 			 * have been freed.
3604 			 */
3605 			if (filefree != NULL) {
3606 				lk.lkt_held = NOHOLDER;
3607 				panic("handle_written_inodeblock: filefree");
3608 			}
3609 			filefree = wk;
3610 			continue;
3611 
3612 		case D_MKDIR:
3613 			handle_written_mkdir(WK_MKDIR(wk), MKDIR_PARENT);
3614 			continue;
3615 
3616 		case D_DIRADD:
3617 			diradd_inode_written(WK_DIRADD(wk), inodedep);
3618 			continue;
3619 
3620 		case D_FREEBLKS:
3621 			wk->wk_state |= COMPLETE;
3622 			if ((wk->wk_state  & ALLCOMPLETE) != ALLCOMPLETE)
3623 				continue;
3624 			/* -- fall through -- */
3625 		case D_FREEFRAG:
3626 		case D_DIRREM:
3627 			add_to_worklist(wk);
3628 			continue;
3629 
3630 		default:
3631 			lk.lkt_held = NOHOLDER;
3632 			panic("handle_written_inodeblock: Unknown type %s",
3633 			    TYPENAME(wk->wk_type));
3634 			/* NOTREACHED */
3635 		}
3636 	}
3637 	if (filefree != NULL) {
3638 		if (free_inodedep(inodedep) == 0) {
3639 			lk.lkt_held = NOHOLDER;
3640 			panic("handle_written_inodeblock: live inodedep");
3641 		}
3642 		add_to_worklist(filefree);
3643 		return (0);
3644 	}
3645 
3646 	/*
3647 	 * If no outstanding dependencies, free it.
3648 	 */
3649 	if (free_inodedep(inodedep) || TAILQ_FIRST(&inodedep->id_inoupdt) == 0)
3650 		return (0);
3651 	return (hadchanges);
3652 }
3653 
3654 /*
3655  * Process a diradd entry after its dependent inode has been written.
3656  * This routine must be called with splbio interrupts blocked.
3657  */
3658 static void
3659 diradd_inode_written(dap, inodedep)
3660 	struct diradd *dap;
3661 	struct inodedep *inodedep;
3662 {
3663 	struct pagedep *pagedep;
3664 
3665 	dap->da_state |= COMPLETE;
3666 	if ((dap->da_state & ALLCOMPLETE) == ALLCOMPLETE) {
3667 		if (dap->da_state & DIRCHG)
3668 			pagedep = dap->da_previous->dm_pagedep;
3669 		else
3670 			pagedep = dap->da_pagedep;
3671 		LIST_REMOVE(dap, da_pdlist);
3672 		LIST_INSERT_HEAD(&pagedep->pd_pendinghd, dap, da_pdlist);
3673 	}
3674 	WORKLIST_INSERT(&inodedep->id_pendinghd, &dap->da_list);
3675 }
3676 
3677 /*
3678  * Handle the completion of a mkdir dependency.
3679  */
3680 static void
3681 handle_written_mkdir(mkdir, type)
3682 	struct mkdir *mkdir;
3683 	int type;
3684 {
3685 	struct diradd *dap;
3686 	struct pagedep *pagedep;
3687 
3688 	if (mkdir->md_state != type) {
3689 		lk.lkt_held = NOHOLDER;
3690 		panic("handle_written_mkdir: bad type");
3691 	}
3692 	dap = mkdir->md_diradd;
3693 	dap->da_state &= ~type;
3694 	if ((dap->da_state & (MKDIR_PARENT | MKDIR_BODY)) == 0)
3695 		dap->da_state |= DEPCOMPLETE;
3696 	if ((dap->da_state & ALLCOMPLETE) == ALLCOMPLETE) {
3697 		if (dap->da_state & DIRCHG)
3698 			pagedep = dap->da_previous->dm_pagedep;
3699 		else
3700 			pagedep = dap->da_pagedep;
3701 		LIST_REMOVE(dap, da_pdlist);
3702 		LIST_INSERT_HEAD(&pagedep->pd_pendinghd, dap, da_pdlist);
3703 	}
3704 	LIST_REMOVE(mkdir, md_mkdirs);
3705 	WORKITEM_FREE(mkdir, D_MKDIR);
3706 }
3707 
3708 /*
3709  * Called from within softdep_disk_write_complete above.
3710  * A write operation was just completed. Removed inodes can
3711  * now be freed and associated block pointers may be committed.
3712  * Note that this routine is always called from interrupt level
3713  * with further splbio interrupts blocked.
3714  */
3715 static int
3716 handle_written_filepage(pagedep, bp)
3717 	struct pagedep *pagedep;
3718 	struct buf *bp;		/* buffer containing the written page */
3719 {
3720 	struct dirrem *dirrem;
3721 	struct diradd *dap, *nextdap;
3722 	struct direct *ep;
3723 	int i, chgs;
3724 
3725 	if ((pagedep->pd_state & IOSTARTED) == 0) {
3726 		lk.lkt_held = NOHOLDER;
3727 		panic("handle_written_filepage: not started");
3728 	}
3729 	pagedep->pd_state &= ~IOSTARTED;
3730 	/*
3731 	 * Process any directory removals that have been committed.
3732 	 */
3733 	while ((dirrem = LIST_FIRST(&pagedep->pd_dirremhd)) != NULL) {
3734 		LIST_REMOVE(dirrem, dm_next);
3735 		dirrem->dm_dirinum = pagedep->pd_ino;
3736 		add_to_worklist(&dirrem->dm_list);
3737 	}
3738 	/*
3739 	 * Free any directory additions that have been committed.
3740 	 */
3741 	while ((dap = LIST_FIRST(&pagedep->pd_pendinghd)) != NULL)
3742 		free_diradd(dap);
3743 	/*
3744 	 * Uncommitted directory entries must be restored.
3745 	 */
3746 	for (chgs = 0, i = 0; i < DAHASHSZ; i++) {
3747 		for (dap = LIST_FIRST(&pagedep->pd_diraddhd[i]); dap;
3748 		     dap = nextdap) {
3749 			nextdap = LIST_NEXT(dap, da_pdlist);
3750 			if (dap->da_state & ATTACHED) {
3751 				lk.lkt_held = NOHOLDER;
3752 				panic("handle_written_filepage: attached");
3753 			}
3754 			ep = (struct direct *)
3755 			    ((char *)bp->b_data + dap->da_offset);
3756 			ep->d_ino = dap->da_newinum;
3757 			dap->da_state &= ~UNDONE;
3758 			dap->da_state |= ATTACHED;
3759 			chgs = 1;
3760 			/*
3761 			 * If the inode referenced by the directory has
3762 			 * been written out, then the dependency can be
3763 			 * moved to the pending list.
3764 			 */
3765 			if ((dap->da_state & ALLCOMPLETE) == ALLCOMPLETE) {
3766 				LIST_REMOVE(dap, da_pdlist);
3767 				LIST_INSERT_HEAD(&pagedep->pd_pendinghd, dap,
3768 				    da_pdlist);
3769 			}
3770 		}
3771 	}
3772 	/*
3773 	 * If there were any rollbacks in the directory, then it must be
3774 	 * marked dirty so that its will eventually get written back in
3775 	 * its correct form.
3776 	 */
3777 	if (chgs) {
3778 		if ((bp->b_flags & B_DELWRI) == 0)
3779 			stat_dir_entry++;
3780 		bdirty(bp);
3781 	}
3782 	/*
3783 	 * If no dependencies remain, the pagedep will be freed.
3784 	 * Otherwise it will remain to update the page before it
3785 	 * is written back to disk.
3786 	 */
3787 	if (LIST_FIRST(&pagedep->pd_pendinghd) == 0) {
3788 		for (i = 0; i < DAHASHSZ; i++)
3789 			if (LIST_FIRST(&pagedep->pd_diraddhd[i]) != NULL)
3790 				break;
3791 		if (i == DAHASHSZ) {
3792 			LIST_REMOVE(pagedep, pd_hash);
3793 			WORKITEM_FREE(pagedep, D_PAGEDEP);
3794 			return (0);
3795 		}
3796 	}
3797 	return (1);
3798 }
3799 
3800 /*
3801  * Writing back in-core inode structures.
3802  *
3803  * The filesystem only accesses an inode's contents when it occupies an
3804  * "in-core" inode structure.  These "in-core" structures are separate from
3805  * the page frames used to cache inode blocks.  Only the latter are
3806  * transferred to/from the disk.  So, when the updated contents of the
3807  * "in-core" inode structure are copied to the corresponding in-memory inode
3808  * block, the dependencies are also transferred.  The following procedure is
3809  * called when copying a dirty "in-core" inode to a cached inode block.
3810  */
3811 
3812 /*
3813  * Called when an inode is loaded from disk. If the effective link count
3814  * differed from the actual link count when it was last flushed, then we
3815  * need to ensure that the correct effective link count is put back.
3816  */
3817 void
3818 softdep_load_inodeblock(ip)
3819 	struct inode *ip;	/* the "in_core" copy of the inode */
3820 {
3821 	struct inodedep *inodedep;
3822 
3823 	/*
3824 	 * Check for alternate nlink count.
3825 	 */
3826 	ip->i_effnlink = ip->i_nlink;
3827 	ACQUIRE_LOCK(&lk);
3828 	if (inodedep_lookup(ip->i_fs, ip->i_number, 0, &inodedep) == 0) {
3829 		FREE_LOCK(&lk);
3830 		return;
3831 	}
3832 	ip->i_effnlink -= inodedep->id_nlinkdelta;
3833 	FREE_LOCK(&lk);
3834 }
3835 
3836 /*
3837  * This routine is called just before the "in-core" inode
3838  * information is to be copied to the in-memory inode block.
3839  * Recall that an inode block contains several inodes. If
3840  * the force flag is set, then the dependencies will be
3841  * cleared so that the update can always be made. Note that
3842  * the buffer is locked when this routine is called, so we
3843  * will never be in the middle of writing the inode block
3844  * to disk.
3845  */
3846 void
3847 softdep_update_inodeblock(ip, bp, waitfor)
3848 	struct inode *ip;	/* the "in_core" copy of the inode */
3849 	struct buf *bp;		/* the buffer containing the inode block */
3850 	int waitfor;		/* nonzero => update must be allowed */
3851 {
3852 	struct inodedep *inodedep;
3853 	struct worklist *wk;
3854 	int error, gotit;
3855 
3856 	/*
3857 	 * If the effective link count is not equal to the actual link
3858 	 * count, then we must track the difference in an inodedep while
3859 	 * the inode is (potentially) tossed out of the cache. Otherwise,
3860 	 * if there is no existing inodedep, then there are no dependencies
3861 	 * to track.
3862 	 */
3863 	ACQUIRE_LOCK(&lk);
3864 	if (inodedep_lookup(ip->i_fs, ip->i_number, 0, &inodedep) == 0) {
3865 		FREE_LOCK(&lk);
3866 		if (ip->i_effnlink != ip->i_nlink)
3867 			panic("softdep_update_inodeblock: bad link count");
3868 		return;
3869 	}
3870 	if (inodedep->id_nlinkdelta != ip->i_nlink - ip->i_effnlink) {
3871 		FREE_LOCK(&lk);
3872 		panic("softdep_update_inodeblock: bad delta");
3873 	}
3874 	/*
3875 	 * Changes have been initiated. Anything depending on these
3876 	 * changes cannot occur until this inode has been written.
3877 	 */
3878 	inodedep->id_state &= ~COMPLETE;
3879 	if ((inodedep->id_state & ONWORKLIST) == 0)
3880 		WORKLIST_INSERT(&bp->b_dep, &inodedep->id_list);
3881 	/*
3882 	 * Any new dependencies associated with the incore inode must
3883 	 * now be moved to the list associated with the buffer holding
3884 	 * the in-memory copy of the inode. Once merged process any
3885 	 * allocdirects that are completed by the merger.
3886 	 */
3887 	merge_inode_lists(inodedep);
3888 	if (TAILQ_FIRST(&inodedep->id_inoupdt) != NULL)
3889 		handle_allocdirect_partdone(TAILQ_FIRST(&inodedep->id_inoupdt));
3890 	/*
3891 	 * Now that the inode has been pushed into the buffer, the
3892 	 * operations dependent on the inode being written to disk
3893 	 * can be moved to the id_bufwait so that they will be
3894 	 * processed when the buffer I/O completes.
3895 	 */
3896 	while ((wk = LIST_FIRST(&inodedep->id_inowait)) != NULL) {
3897 		WORKLIST_REMOVE(wk);
3898 		WORKLIST_INSERT(&inodedep->id_bufwait, wk);
3899 	}
3900 	/*
3901 	 * Newly allocated inodes cannot be written until the bitmap
3902 	 * that allocates them have been written (indicated by
3903 	 * DEPCOMPLETE being set in id_state). If we are doing a
3904 	 * forced sync (e.g., an fsync on a file), we force the bitmap
3905 	 * to be written so that the update can be done.
3906 	 */
3907 	if ((inodedep->id_state & DEPCOMPLETE) != 0 || waitfor == 0) {
3908 		FREE_LOCK(&lk);
3909 		return;
3910 	}
3911 	gotit = getdirtybuf(&inodedep->id_buf, MNT_WAIT);
3912 	FREE_LOCK(&lk);
3913 	if (gotit &&
3914 	    (error = VOP_BWRITE(inodedep->id_buf->b_vp, inodedep->id_buf)) != 0)
3915 		softdep_error("softdep_update_inodeblock: bwrite", error);
3916 	if ((inodedep->id_state & DEPCOMPLETE) == 0)
3917 		panic("softdep_update_inodeblock: update failed");
3918 }
3919 
3920 /*
3921  * Merge the new inode dependency list (id_newinoupdt) into the old
3922  * inode dependency list (id_inoupdt). This routine must be called
3923  * with splbio interrupts blocked.
3924  */
3925 static void
3926 merge_inode_lists(inodedep)
3927 	struct inodedep *inodedep;
3928 {
3929 	struct allocdirect *listadp, *newadp;
3930 
3931 	newadp = TAILQ_FIRST(&inodedep->id_newinoupdt);
3932 	for (listadp = TAILQ_FIRST(&inodedep->id_inoupdt); listadp && newadp;) {
3933 		if (listadp->ad_lbn < newadp->ad_lbn) {
3934 			listadp = TAILQ_NEXT(listadp, ad_next);
3935 			continue;
3936 		}
3937 		TAILQ_REMOVE(&inodedep->id_newinoupdt, newadp, ad_next);
3938 		TAILQ_INSERT_BEFORE(listadp, newadp, ad_next);
3939 		if (listadp->ad_lbn == newadp->ad_lbn) {
3940 			allocdirect_merge(&inodedep->id_inoupdt, newadp,
3941 			    listadp);
3942 			listadp = newadp;
3943 		}
3944 		newadp = TAILQ_FIRST(&inodedep->id_newinoupdt);
3945 	}
3946 	while ((newadp = TAILQ_FIRST(&inodedep->id_newinoupdt)) != NULL) {
3947 		TAILQ_REMOVE(&inodedep->id_newinoupdt, newadp, ad_next);
3948 		TAILQ_INSERT_TAIL(&inodedep->id_inoupdt, newadp, ad_next);
3949 	}
3950 }
3951 
3952 /*
3953  * If we are doing an fsync, then we must ensure that any directory
3954  * entries for the inode have been written after the inode gets to disk.
3955  */
3956 static int
3957 softdep_fsync(vp)
3958 	struct vnode *vp;	/* the "in_core" copy of the inode */
3959 {
3960 	struct inodedep *inodedep;
3961 	struct pagedep *pagedep;
3962 	struct worklist *wk;
3963 	struct diradd *dap;
3964 	struct mount *mnt;
3965 	struct vnode *pvp;
3966 	struct inode *ip;
3967 	struct buf *bp;
3968 	struct fs *fs;
3969 	struct thread *td = curthread;		/* XXX */
3970 	int error, flushparent;
3971 	ino_t parentino;
3972 	ufs_lbn_t lbn;
3973 
3974 	ip = VTOI(vp);
3975 	fs = ip->i_fs;
3976 	ACQUIRE_LOCK(&lk);
3977 	if (inodedep_lookup(fs, ip->i_number, 0, &inodedep) == 0) {
3978 		FREE_LOCK(&lk);
3979 		return (0);
3980 	}
3981 	if (LIST_FIRST(&inodedep->id_inowait) != NULL ||
3982 	    LIST_FIRST(&inodedep->id_bufwait) != NULL ||
3983 	    TAILQ_FIRST(&inodedep->id_inoupdt) != NULL ||
3984 	    TAILQ_FIRST(&inodedep->id_newinoupdt) != NULL) {
3985 		FREE_LOCK(&lk);
3986 		panic("softdep_fsync: pending ops");
3987 	}
3988 	for (error = 0, flushparent = 0; ; ) {
3989 		if ((wk = LIST_FIRST(&inodedep->id_pendinghd)) == NULL)
3990 			break;
3991 		if (wk->wk_type != D_DIRADD) {
3992 			FREE_LOCK(&lk);
3993 			panic("softdep_fsync: Unexpected type %s",
3994 			    TYPENAME(wk->wk_type));
3995 		}
3996 		dap = WK_DIRADD(wk);
3997 		/*
3998 		 * Flush our parent if this directory entry
3999 		 * has a MKDIR_PARENT dependency.
4000 		 */
4001 		if (dap->da_state & DIRCHG)
4002 			pagedep = dap->da_previous->dm_pagedep;
4003 		else
4004 			pagedep = dap->da_pagedep;
4005 		mnt = pagedep->pd_mnt;
4006 		parentino = pagedep->pd_ino;
4007 		lbn = pagedep->pd_lbn;
4008 		if ((dap->da_state & (MKDIR_BODY | COMPLETE)) != COMPLETE) {
4009 			FREE_LOCK(&lk);
4010 			panic("softdep_fsync: dirty");
4011 		}
4012 		flushparent = dap->da_state & MKDIR_PARENT;
4013 		/*
4014 		 * If we are being fsync'ed as part of vgone'ing this vnode,
4015 		 * then we will not be able to release and recover the
4016 		 * vnode below, so we just have to give up on writing its
4017 		 * directory entry out. It will eventually be written, just
4018 		 * not now, but then the user was not asking to have it
4019 		 * written, so we are not breaking any promises.
4020 		 */
4021 		if (vp->v_flag & VRECLAIMED)
4022 			break;
4023 		/*
4024 		 * We prevent deadlock by always fetching inodes from the
4025 		 * root, moving down the directory tree. Thus, when fetching
4026 		 * our parent directory, we must unlock ourselves before
4027 		 * requesting the lock on our parent. See the comment in
4028 		 * ufs_lookup for details on possible races.
4029 		 */
4030 		FREE_LOCK(&lk);
4031 		VOP_UNLOCK(vp, 0, td);
4032 		error = VFS_VGET(mnt, parentino, &pvp);
4033 		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
4034 		if (error != 0)
4035 			return (error);
4036 		if (flushparent) {
4037 			if ((error = UFS_UPDATE(pvp, 1)) != 0) {
4038 				vput(pvp);
4039 				return (error);
4040 			}
4041 		}
4042 		/*
4043 		 * Flush directory page containing the inode's name.
4044 		 */
4045 		error = bread(pvp, lbn, blksize(fs, VTOI(pvp), lbn), &bp);
4046 		if (error == 0)
4047 			error = VOP_BWRITE(bp->b_vp, bp);
4048 		vput(pvp);
4049 		if (error != 0)
4050 			return (error);
4051 		ACQUIRE_LOCK(&lk);
4052 		if (inodedep_lookup(fs, ip->i_number, 0, &inodedep) == 0)
4053 			break;
4054 	}
4055 	FREE_LOCK(&lk);
4056 	return (0);
4057 }
4058 
4059 /*
4060  * Flush all the dirty bitmaps associated with the block device
4061  * before flushing the rest of the dirty blocks so as to reduce
4062  * the number of dependencies that will have to be rolled back.
4063  */
4064 static int softdep_fsync_mountdev_bp(struct buf *bp, void *data);
4065 
4066 void
4067 softdep_fsync_mountdev(vp)
4068 	struct vnode *vp;
4069 {
4070 	if (!vn_isdisk(vp, NULL))
4071 		panic("softdep_fsync_mountdev: vnode not a disk");
4072 	ACQUIRE_LOCK(&lk);
4073 	RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree, NULL,
4074 		softdep_fsync_mountdev_bp, NULL);
4075 	drain_output(vp, 1);
4076 	FREE_LOCK(&lk);
4077 }
4078 
4079 static int
4080 softdep_fsync_mountdev_bp(struct buf *bp, void *data)
4081 {
4082 	struct worklist *wk;
4083 
4084 	/*
4085 	 * If it is already scheduled, skip to the next buffer.
4086 	 */
4087 	if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT))
4088 		return(0);
4089 	if ((bp->b_flags & B_DELWRI) == 0) {
4090 		FREE_LOCK(&lk);
4091 		panic("softdep_fsync_mountdev: not dirty");
4092 	}
4093 	/*
4094 	 * We are only interested in bitmaps with outstanding
4095 	 * dependencies.
4096 	 */
4097 	if ((wk = LIST_FIRST(&bp->b_dep)) == NULL ||
4098 	    wk->wk_type != D_BMSAFEMAP ||
4099 	    (bp->b_xflags & BX_BKGRDINPROG)) {
4100 		BUF_UNLOCK(bp);
4101 		return(0);
4102 	}
4103 	bremfree(bp);
4104 	FREE_LOCK(&lk);
4105 	(void) bawrite(bp);
4106 	ACQUIRE_LOCK(&lk);
4107 	return(0);
4108 }
4109 
4110 /*
4111  * This routine is called when we are trying to synchronously flush a
4112  * file. This routine must eliminate any filesystem metadata dependencies
4113  * so that the syncing routine can succeed by pushing the dirty blocks
4114  * associated with the file. If any I/O errors occur, they are returned.
4115  */
4116 struct softdep_sync_metadata_info {
4117 	struct vnode *vp;
4118 	int waitfor;
4119 };
4120 
4121 static int softdep_sync_metadata_bp(struct buf *bp, void *data);
4122 
4123 int
4124 softdep_sync_metadata(struct vnode *vp, struct thread *td)
4125 {
4126 	struct softdep_sync_metadata_info info;
4127 	int error, waitfor;
4128 
4129 	/*
4130 	 * Check whether this vnode is involved in a filesystem
4131 	 * that is doing soft dependency processing.
4132 	 */
4133 	if (!vn_isdisk(vp, NULL)) {
4134 		if (!DOINGSOFTDEP(vp))
4135 			return (0);
4136 	} else
4137 		if (vp->v_rdev->si_mountpoint == NULL ||
4138 		    (vp->v_rdev->si_mountpoint->mnt_flag & MNT_SOFTDEP) == 0)
4139 			return (0);
4140 	/*
4141 	 * Ensure that any direct block dependencies have been cleared.
4142 	 */
4143 	ACQUIRE_LOCK(&lk);
4144 	if ((error = flush_inodedep_deps(VTOI(vp)->i_fs, VTOI(vp)->i_number))) {
4145 		FREE_LOCK(&lk);
4146 		return (error);
4147 	}
4148 	/*
4149 	 * For most files, the only metadata dependencies are the
4150 	 * cylinder group maps that allocate their inode or blocks.
4151 	 * The block allocation dependencies can be found by traversing
4152 	 * the dependency lists for any buffers that remain on their
4153 	 * dirty buffer list. The inode allocation dependency will
4154 	 * be resolved when the inode is updated with MNT_WAIT.
4155 	 * This work is done in two passes. The first pass grabs most
4156 	 * of the buffers and begins asynchronously writing them. The
4157 	 * only way to wait for these asynchronous writes is to sleep
4158 	 * on the filesystem vnode which may stay busy for a long time
4159 	 * if the filesystem is active. So, instead, we make a second
4160 	 * pass over the dependencies blocking on each write. In the
4161 	 * usual case we will be blocking against a write that we
4162 	 * initiated, so when it is done the dependency will have been
4163 	 * resolved. Thus the second pass is expected to end quickly.
4164 	 */
4165 	waitfor = MNT_NOWAIT;
4166 top:
4167 	/*
4168 	 * We must wait for any I/O in progress to finish so that
4169 	 * all potential buffers on the dirty list will be visible.
4170 	 */
4171 	drain_output(vp, 1);
4172 	info.vp = vp;
4173 	info.waitfor = waitfor;
4174 	error = RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree, NULL,
4175 			softdep_sync_metadata_bp, &info);
4176 	if (error < 0) {
4177 		FREE_LOCK(&lk);
4178 		return(-error);	/* error code */
4179 	}
4180 
4181 	/*
4182 	 * The brief unlock is to allow any pent up dependency
4183 	 * processing to be done.  Then proceed with the second pass.
4184 	 */
4185 	if (waitfor == MNT_NOWAIT) {
4186 		waitfor = MNT_WAIT;
4187 		FREE_LOCK(&lk);
4188 		ACQUIRE_LOCK(&lk);
4189 		goto top;
4190 	}
4191 
4192 	/*
4193 	 * If we have managed to get rid of all the dirty buffers,
4194 	 * then we are done. For certain directories and block
4195 	 * devices, we may need to do further work.
4196 	 *
4197 	 * We must wait for any I/O in progress to finish so that
4198 	 * all potential buffers on the dirty list will be visible.
4199 	 */
4200 	drain_output(vp, 1);
4201 	if (RB_EMPTY(&vp->v_rbdirty_tree)) {
4202 		FREE_LOCK(&lk);
4203 		return (0);
4204 	}
4205 
4206 	FREE_LOCK(&lk);
4207 	/*
4208 	 * If we are trying to sync a block device, some of its buffers may
4209 	 * contain metadata that cannot be written until the contents of some
4210 	 * partially written files have been written to disk. The only easy
4211 	 * way to accomplish this is to sync the entire filesystem (luckily
4212 	 * this happens rarely).
4213 	 */
4214 	if (vn_isdisk(vp, NULL) &&
4215 	    vp->v_rdev &&
4216 	    vp->v_rdev->si_mountpoint && !VOP_ISLOCKED(vp, NULL) &&
4217 	    (error = VFS_SYNC(vp->v_rdev->si_mountpoint, MNT_WAIT, td)) != 0)
4218 		return (error);
4219 	return (0);
4220 }
4221 
4222 static int
4223 softdep_sync_metadata_bp(struct buf *bp, void *data)
4224 {
4225 	struct softdep_sync_metadata_info *info = data;
4226 	struct pagedep *pagedep;
4227 	struct allocdirect *adp;
4228 	struct allocindir *aip;
4229 	struct worklist *wk;
4230 	struct buf *nbp;
4231 	int error;
4232 	int i;
4233 
4234 	if (getdirtybuf(&bp, MNT_WAIT) == 0)
4235 		return (0);
4236 
4237 	/*
4238 	 * As we hold the buffer locked, none of its dependencies
4239 	 * will disappear.
4240 	 */
4241 	LIST_FOREACH(wk, &bp->b_dep, wk_list) {
4242 		switch (wk->wk_type) {
4243 
4244 		case D_ALLOCDIRECT:
4245 			adp = WK_ALLOCDIRECT(wk);
4246 			if (adp->ad_state & DEPCOMPLETE)
4247 				break;
4248 			nbp = adp->ad_buf;
4249 			if (getdirtybuf(&nbp, info->waitfor) == 0)
4250 				break;
4251 			FREE_LOCK(&lk);
4252 			if (info->waitfor == MNT_NOWAIT) {
4253 				bawrite(nbp);
4254 			} else if ((error = VOP_BWRITE(nbp->b_vp, nbp)) != 0) {
4255 				bawrite(bp);
4256 				ACQUIRE_LOCK(&lk);
4257 				return (-error);
4258 			}
4259 			ACQUIRE_LOCK(&lk);
4260 			break;
4261 
4262 		case D_ALLOCINDIR:
4263 			aip = WK_ALLOCINDIR(wk);
4264 			if (aip->ai_state & DEPCOMPLETE)
4265 				break;
4266 			nbp = aip->ai_buf;
4267 			if (getdirtybuf(&nbp, info->waitfor) == 0)
4268 				break;
4269 			FREE_LOCK(&lk);
4270 			if (info->waitfor == MNT_NOWAIT) {
4271 				bawrite(nbp);
4272 			} else if ((error = VOP_BWRITE(nbp->b_vp, nbp)) != 0) {
4273 				bawrite(bp);
4274 				ACQUIRE_LOCK(&lk);
4275 				return (-error);
4276 			}
4277 			ACQUIRE_LOCK(&lk);
4278 			break;
4279 
4280 		case D_INDIRDEP:
4281 		restart:
4282 
4283 			LIST_FOREACH(aip, &WK_INDIRDEP(wk)->ir_deplisthd, ai_next) {
4284 				if (aip->ai_state & DEPCOMPLETE)
4285 					continue;
4286 				nbp = aip->ai_buf;
4287 				if (getdirtybuf(&nbp, MNT_WAIT) == 0)
4288 					goto restart;
4289 				FREE_LOCK(&lk);
4290 				if ((error = VOP_BWRITE(nbp->b_vp, nbp)) != 0) {
4291 					bawrite(bp);
4292 					ACQUIRE_LOCK(&lk);
4293 					return (-error);
4294 				}
4295 				ACQUIRE_LOCK(&lk);
4296 				goto restart;
4297 			}
4298 			break;
4299 
4300 		case D_INODEDEP:
4301 			if ((error = flush_inodedep_deps(WK_INODEDEP(wk)->id_fs,
4302 			    WK_INODEDEP(wk)->id_ino)) != 0) {
4303 				FREE_LOCK(&lk);
4304 				bawrite(bp);
4305 				ACQUIRE_LOCK(&lk);
4306 				return (-error);
4307 			}
4308 			break;
4309 
4310 		case D_PAGEDEP:
4311 			/*
4312 			 * We are trying to sync a directory that may
4313 			 * have dependencies on both its own metadata
4314 			 * and/or dependencies on the inodes of any
4315 			 * recently allocated files. We walk its diradd
4316 			 * lists pushing out the associated inode.
4317 			 */
4318 			pagedep = WK_PAGEDEP(wk);
4319 			for (i = 0; i < DAHASHSZ; i++) {
4320 				if (LIST_FIRST(&pagedep->pd_diraddhd[i]) == 0)
4321 					continue;
4322 				if ((error =
4323 				    flush_pagedep_deps(info->vp,
4324 						pagedep->pd_mnt,
4325 						&pagedep->pd_diraddhd[i]))) {
4326 					FREE_LOCK(&lk);
4327 					bawrite(bp);
4328 					ACQUIRE_LOCK(&lk);
4329 					return (-error);
4330 				}
4331 			}
4332 			break;
4333 
4334 		case D_MKDIR:
4335 			/*
4336 			 * This case should never happen if the vnode has
4337 			 * been properly sync'ed. However, if this function
4338 			 * is used at a place where the vnode has not yet
4339 			 * been sync'ed, this dependency can show up. So,
4340 			 * rather than panic, just flush it.
4341 			 */
4342 			nbp = WK_MKDIR(wk)->md_buf;
4343 			if (getdirtybuf(&nbp, info->waitfor) == 0)
4344 				break;
4345 			FREE_LOCK(&lk);
4346 			if (info->waitfor == MNT_NOWAIT) {
4347 				bawrite(nbp);
4348 			} else if ((error = VOP_BWRITE(nbp->b_vp, nbp)) != 0) {
4349 				bawrite(bp);
4350 				ACQUIRE_LOCK(&lk);
4351 				return (-error);
4352 			}
4353 			ACQUIRE_LOCK(&lk);
4354 			break;
4355 
4356 		case D_BMSAFEMAP:
4357 			/*
4358 			 * This case should never happen if the vnode has
4359 			 * been properly sync'ed. However, if this function
4360 			 * is used at a place where the vnode has not yet
4361 			 * been sync'ed, this dependency can show up. So,
4362 			 * rather than panic, just flush it.
4363 			 */
4364 			nbp = WK_BMSAFEMAP(wk)->sm_buf;
4365 			if (getdirtybuf(&nbp, info->waitfor) == 0)
4366 				break;
4367 			FREE_LOCK(&lk);
4368 			if (info->waitfor == MNT_NOWAIT) {
4369 				bawrite(nbp);
4370 			} else if ((error = VOP_BWRITE(nbp->b_vp, nbp)) != 0) {
4371 				bawrite(bp);
4372 				ACQUIRE_LOCK(&lk);
4373 				return (-error);
4374 			}
4375 			ACQUIRE_LOCK(&lk);
4376 			break;
4377 
4378 		default:
4379 			FREE_LOCK(&lk);
4380 			panic("softdep_sync_metadata: Unknown type %s",
4381 			    TYPENAME(wk->wk_type));
4382 			/* NOTREACHED */
4383 		}
4384 	}
4385 	FREE_LOCK(&lk);
4386 	bawrite(bp);
4387 	ACQUIRE_LOCK(&lk);
4388 	return(0);
4389 }
4390 
4391 /*
4392  * Flush the dependencies associated with an inodedep.
4393  * Called with splbio blocked.
4394  */
4395 static int
4396 flush_inodedep_deps(fs, ino)
4397 	struct fs *fs;
4398 	ino_t ino;
4399 {
4400 	struct inodedep *inodedep;
4401 	struct allocdirect *adp;
4402 	int error, waitfor;
4403 	struct buf *bp;
4404 
4405 	/*
4406 	 * This work is done in two passes. The first pass grabs most
4407 	 * of the buffers and begins asynchronously writing them. The
4408 	 * only way to wait for these asynchronous writes is to sleep
4409 	 * on the filesystem vnode which may stay busy for a long time
4410 	 * if the filesystem is active. So, instead, we make a second
4411 	 * pass over the dependencies blocking on each write. In the
4412 	 * usual case we will be blocking against a write that we
4413 	 * initiated, so when it is done the dependency will have been
4414 	 * resolved. Thus the second pass is expected to end quickly.
4415 	 * We give a brief window at the top of the loop to allow
4416 	 * any pending I/O to complete.
4417 	 */
4418 	for (waitfor = MNT_NOWAIT; ; ) {
4419 		FREE_LOCK(&lk);
4420 		ACQUIRE_LOCK(&lk);
4421 		if (inodedep_lookup(fs, ino, 0, &inodedep) == 0)
4422 			return (0);
4423 		TAILQ_FOREACH(adp, &inodedep->id_inoupdt, ad_next) {
4424 			if (adp->ad_state & DEPCOMPLETE)
4425 				continue;
4426 			bp = adp->ad_buf;
4427 			if (getdirtybuf(&bp, waitfor) == 0) {
4428 				if (waitfor == MNT_NOWAIT)
4429 					continue;
4430 				break;
4431 			}
4432 			FREE_LOCK(&lk);
4433 			if (waitfor == MNT_NOWAIT) {
4434 				bawrite(bp);
4435 			} else if ((error = VOP_BWRITE(bp->b_vp, bp)) != 0) {
4436 				ACQUIRE_LOCK(&lk);
4437 				return (error);
4438 			}
4439 			ACQUIRE_LOCK(&lk);
4440 			break;
4441 		}
4442 		if (adp != NULL)
4443 			continue;
4444 		TAILQ_FOREACH(adp, &inodedep->id_newinoupdt, ad_next) {
4445 			if (adp->ad_state & DEPCOMPLETE)
4446 				continue;
4447 			bp = adp->ad_buf;
4448 			if (getdirtybuf(&bp, waitfor) == 0) {
4449 				if (waitfor == MNT_NOWAIT)
4450 					continue;
4451 				break;
4452 			}
4453 			FREE_LOCK(&lk);
4454 			if (waitfor == MNT_NOWAIT) {
4455 				bawrite(bp);
4456 			} else if ((error = VOP_BWRITE(bp->b_vp, bp)) != 0) {
4457 				ACQUIRE_LOCK(&lk);
4458 				return (error);
4459 			}
4460 			ACQUIRE_LOCK(&lk);
4461 			break;
4462 		}
4463 		if (adp != NULL)
4464 			continue;
4465 		/*
4466 		 * If pass2, we are done, otherwise do pass 2.
4467 		 */
4468 		if (waitfor == MNT_WAIT)
4469 			break;
4470 		waitfor = MNT_WAIT;
4471 	}
4472 	/*
4473 	 * Try freeing inodedep in case all dependencies have been removed.
4474 	 */
4475 	if (inodedep_lookup(fs, ino, 0, &inodedep) != 0)
4476 		(void) free_inodedep(inodedep);
4477 	return (0);
4478 }
4479 
4480 /*
4481  * Eliminate a pagedep dependency by flushing out all its diradd dependencies.
4482  * Called with splbio blocked.
4483  */
4484 static int
4485 flush_pagedep_deps(pvp, mp, diraddhdp)
4486 	struct vnode *pvp;
4487 	struct mount *mp;
4488 	struct diraddhd *diraddhdp;
4489 {
4490 	struct thread *td = curthread;		/* XXX */
4491 	struct inodedep *inodedep;
4492 	struct ufsmount *ump;
4493 	struct diradd *dap;
4494 	struct vnode *vp;
4495 	int gotit, error = 0;
4496 	struct buf *bp;
4497 	ino_t inum;
4498 
4499 	ump = VFSTOUFS(mp);
4500 	while ((dap = LIST_FIRST(diraddhdp)) != NULL) {
4501 		/*
4502 		 * Flush ourselves if this directory entry
4503 		 * has a MKDIR_PARENT dependency.
4504 		 */
4505 		if (dap->da_state & MKDIR_PARENT) {
4506 			FREE_LOCK(&lk);
4507 			if ((error = UFS_UPDATE(pvp, 1)) != 0)
4508 				break;
4509 			ACQUIRE_LOCK(&lk);
4510 			/*
4511 			 * If that cleared dependencies, go on to next.
4512 			 */
4513 			if (dap != LIST_FIRST(diraddhdp))
4514 				continue;
4515 			if (dap->da_state & MKDIR_PARENT) {
4516 				FREE_LOCK(&lk);
4517 				panic("flush_pagedep_deps: MKDIR_PARENT");
4518 			}
4519 		}
4520 		/*
4521 		 * A newly allocated directory must have its "." and
4522 		 * ".." entries written out before its name can be
4523 		 * committed in its parent. We do not want or need
4524 		 * the full semantics of a synchronous VOP_FSYNC as
4525 		 * that may end up here again, once for each directory
4526 		 * level in the filesystem. Instead, we push the blocks
4527 		 * and wait for them to clear. We have to fsync twice
4528 		 * because the first call may choose to defer blocks
4529 		 * that still have dependencies, but deferral will
4530 		 * happen at most once.
4531 		 */
4532 		inum = dap->da_newinum;
4533 		if (dap->da_state & MKDIR_BODY) {
4534 			FREE_LOCK(&lk);
4535 			if ((error = VFS_VGET(mp, inum, &vp)) != 0)
4536 				break;
4537 			if ((error=VOP_FSYNC(vp, MNT_NOWAIT, td)) ||
4538 			    (error=VOP_FSYNC(vp, MNT_NOWAIT, td))) {
4539 				vput(vp);
4540 				break;
4541 			}
4542 			drain_output(vp, 0);
4543 			vput(vp);
4544 			ACQUIRE_LOCK(&lk);
4545 			/*
4546 			 * If that cleared dependencies, go on to next.
4547 			 */
4548 			if (dap != LIST_FIRST(diraddhdp))
4549 				continue;
4550 			if (dap->da_state & MKDIR_BODY) {
4551 				FREE_LOCK(&lk);
4552 				panic("flush_pagedep_deps: MKDIR_BODY");
4553 			}
4554 		}
4555 		/*
4556 		 * Flush the inode on which the directory entry depends.
4557 		 * Having accounted for MKDIR_PARENT and MKDIR_BODY above,
4558 		 * the only remaining dependency is that the updated inode
4559 		 * count must get pushed to disk. The inode has already
4560 		 * been pushed into its inode buffer (via VOP_UPDATE) at
4561 		 * the time of the reference count change. So we need only
4562 		 * locate that buffer, ensure that there will be no rollback
4563 		 * caused by a bitmap dependency, then write the inode buffer.
4564 		 */
4565 		if (inodedep_lookup(ump->um_fs, inum, 0, &inodedep) == 0) {
4566 			FREE_LOCK(&lk);
4567 			panic("flush_pagedep_deps: lost inode");
4568 		}
4569 		/*
4570 		 * If the inode still has bitmap dependencies,
4571 		 * push them to disk.
4572 		 */
4573 		if ((inodedep->id_state & DEPCOMPLETE) == 0) {
4574 			gotit = getdirtybuf(&inodedep->id_buf, MNT_WAIT);
4575 			FREE_LOCK(&lk);
4576 			if (gotit &&
4577 			    (error = VOP_BWRITE(inodedep->id_buf->b_vp,
4578 			     inodedep->id_buf)) != 0)
4579 				break;
4580 			ACQUIRE_LOCK(&lk);
4581 			if (dap != LIST_FIRST(diraddhdp))
4582 				continue;
4583 		}
4584 		/*
4585 		 * If the inode is still sitting in a buffer waiting
4586 		 * to be written, push it to disk.
4587 		 */
4588 		FREE_LOCK(&lk);
4589 		if ((error = bread(ump->um_devvp,
4590 		    fsbtodb(ump->um_fs, ino_to_fsba(ump->um_fs, inum)),
4591 		    (int)ump->um_fs->fs_bsize, &bp)) != 0)
4592 			break;
4593 		if ((error = VOP_BWRITE(bp->b_vp, bp)) != 0)
4594 			break;
4595 		ACQUIRE_LOCK(&lk);
4596 		/*
4597 		 * If we have failed to get rid of all the dependencies
4598 		 * then something is seriously wrong.
4599 		 */
4600 		if (dap == LIST_FIRST(diraddhdp)) {
4601 			FREE_LOCK(&lk);
4602 			panic("flush_pagedep_deps: flush failed");
4603 		}
4604 	}
4605 	if (error)
4606 		ACQUIRE_LOCK(&lk);
4607 	return (error);
4608 }
4609 
4610 /*
4611  * A large burst of file addition or deletion activity can drive the
4612  * memory load excessively high. First attempt to slow things down
4613  * using the techniques below. If that fails, this routine requests
4614  * the offending operations to fall back to running synchronously
4615  * until the memory load returns to a reasonable level.
4616  */
4617 int
4618 softdep_slowdown(vp)
4619 	struct vnode *vp;
4620 {
4621 	int max_softdeps_hard;
4622 
4623 	max_softdeps_hard = max_softdeps * 11 / 10;
4624 	if (num_dirrem < max_softdeps_hard / 2 &&
4625 	    num_inodedep < max_softdeps_hard)
4626 		return (0);
4627 	stat_sync_limit_hit += 1;
4628 	return (1);
4629 }
4630 
4631 /*
4632  * If memory utilization has gotten too high, deliberately slow things
4633  * down and speed up the I/O processing.
4634  */
4635 static int
4636 request_cleanup(resource, islocked)
4637 	int resource;
4638 	int islocked;
4639 {
4640 	struct thread *td = curthread;		/* XXX */
4641 
4642 	/*
4643 	 * We never hold up the filesystem syncer process.
4644 	 */
4645 	if (td == filesys_syncer)
4646 		return (0);
4647 	/*
4648 	 * First check to see if the work list has gotten backlogged.
4649 	 * If it has, co-opt this process to help clean up two entries.
4650 	 * Because this process may hold inodes locked, we cannot
4651 	 * handle any remove requests that might block on a locked
4652 	 * inode as that could lead to deadlock.
4653 	 */
4654 	if (num_on_worklist > max_softdeps / 10) {
4655 		if (islocked)
4656 			FREE_LOCK(&lk);
4657 		process_worklist_item(NULL, LK_NOWAIT);
4658 		process_worklist_item(NULL, LK_NOWAIT);
4659 		stat_worklist_push += 2;
4660 		if (islocked)
4661 			ACQUIRE_LOCK(&lk);
4662 		return(1);
4663 	}
4664 
4665 	/*
4666 	 * If we are resource constrained on inode dependencies, try
4667 	 * flushing some dirty inodes. Otherwise, we are constrained
4668 	 * by file deletions, so try accelerating flushes of directories
4669 	 * with removal dependencies. We would like to do the cleanup
4670 	 * here, but we probably hold an inode locked at this point and
4671 	 * that might deadlock against one that we try to clean. So,
4672 	 * the best that we can do is request the syncer daemon to do
4673 	 * the cleanup for us.
4674 	 */
4675 	switch (resource) {
4676 
4677 	case FLUSH_INODES:
4678 		stat_ino_limit_push += 1;
4679 		req_clear_inodedeps += 1;
4680 		stat_countp = &stat_ino_limit_hit;
4681 		break;
4682 
4683 	case FLUSH_REMOVE:
4684 		stat_blk_limit_push += 1;
4685 		req_clear_remove += 1;
4686 		stat_countp = &stat_blk_limit_hit;
4687 		break;
4688 
4689 	default:
4690 		if (islocked)
4691 			FREE_LOCK(&lk);
4692 		panic("request_cleanup: unknown type");
4693 	}
4694 	/*
4695 	 * Hopefully the syncer daemon will catch up and awaken us.
4696 	 * We wait at most tickdelay before proceeding in any case.
4697 	 */
4698 	if (islocked == 0)
4699 		ACQUIRE_LOCK(&lk);
4700 	crit_enter();
4701 	proc_waiting += 1;
4702 	if (!callout_active(&handle))
4703 		callout_reset(&handle, tickdelay > 2 ? tickdelay : 2,
4704 			      pause_timer, NULL);
4705 	interlocked_sleep(&lk, SLEEP, (caddr_t)&proc_waiting, 0,
4706 	    "softupdate", 0);
4707 	proc_waiting -= 1;
4708 	crit_exit();
4709 	if (islocked == 0)
4710 		FREE_LOCK(&lk);
4711 	return (1);
4712 }
4713 
4714 /*
4715  * Awaken processes pausing in request_cleanup and clear proc_waiting
4716  * to indicate that there is no longer a timer running.
4717  */
4718 void
4719 pause_timer(arg)
4720 	void *arg;
4721 {
4722 	*stat_countp += 1;
4723 	wakeup_one(&proc_waiting);
4724 	if (proc_waiting > 0)
4725 		callout_reset(&handle, tickdelay > 2 ? tickdelay : 2,
4726 			      pause_timer, NULL);
4727 	else
4728 		callout_deactivate(&handle);
4729 }
4730 
4731 /*
4732  * Flush out a directory with at least one removal dependency in an effort to
4733  * reduce the number of dirrem, freefile, and freeblks dependency structures.
4734  */
4735 static void
4736 clear_remove(struct thread *td)
4737 {
4738 	struct pagedep_hashhead *pagedephd;
4739 	struct pagedep *pagedep;
4740 	static int next = 0;
4741 	struct mount *mp;
4742 	struct vnode *vp;
4743 	int error, cnt;
4744 	ino_t ino;
4745 
4746 	ACQUIRE_LOCK(&lk);
4747 	for (cnt = 0; cnt < pagedep_hash; cnt++) {
4748 		pagedephd = &pagedep_hashtbl[next++];
4749 		if (next >= pagedep_hash)
4750 			next = 0;
4751 		LIST_FOREACH(pagedep, pagedephd, pd_hash) {
4752 			if (LIST_FIRST(&pagedep->pd_dirremhd) == NULL)
4753 				continue;
4754 			mp = pagedep->pd_mnt;
4755 			ino = pagedep->pd_ino;
4756 			FREE_LOCK(&lk);
4757 			if ((error = VFS_VGET(mp, ino, &vp)) != 0) {
4758 				softdep_error("clear_remove: vget", error);
4759 				return;
4760 			}
4761 			if ((error = VOP_FSYNC(vp, MNT_NOWAIT, td)))
4762 				softdep_error("clear_remove: fsync", error);
4763 			drain_output(vp, 0);
4764 			vput(vp);
4765 			return;
4766 		}
4767 	}
4768 	FREE_LOCK(&lk);
4769 }
4770 
4771 /*
4772  * Clear out a block of dirty inodes in an effort to reduce
4773  * the number of inodedep dependency structures.
4774  */
4775 struct clear_inodedeps_info {
4776 	struct fs *fs;
4777 	struct mount *mp;
4778 };
4779 
4780 static int
4781 clear_inodedeps_mountlist_callback(struct mount *mp, void *data)
4782 {
4783 	struct clear_inodedeps_info *info = data;
4784 
4785 	if ((mp->mnt_flag & MNT_SOFTDEP) && info->fs == VFSTOUFS(mp)->um_fs) {
4786 		info->mp = mp;
4787 		return(-1);
4788 	}
4789 	return(0);
4790 }
4791 
4792 static void
4793 clear_inodedeps(struct thread *td)
4794 {
4795 	struct clear_inodedeps_info info;
4796 	struct inodedep_hashhead *inodedephd;
4797 	struct inodedep *inodedep;
4798 	static int next = 0;
4799 	struct vnode *vp;
4800 	struct fs *fs;
4801 	int error, cnt;
4802 	ino_t firstino, lastino, ino;
4803 
4804 	ACQUIRE_LOCK(&lk);
4805 	/*
4806 	 * Pick a random inode dependency to be cleared.
4807 	 * We will then gather up all the inodes in its block
4808 	 * that have dependencies and flush them out.
4809 	 */
4810 	for (cnt = 0; cnt < inodedep_hash; cnt++) {
4811 		inodedephd = &inodedep_hashtbl[next++];
4812 		if (next >= inodedep_hash)
4813 			next = 0;
4814 		if ((inodedep = LIST_FIRST(inodedephd)) != NULL)
4815 			break;
4816 	}
4817 	if (inodedep == NULL) {
4818 		FREE_LOCK(&lk);
4819 		return;
4820 	}
4821 	/*
4822 	 * Ugly code to find mount point given pointer to superblock.
4823 	 */
4824 	fs = inodedep->id_fs;
4825 	info.mp = NULL;
4826 	info.fs = fs;
4827 	mountlist_scan(clear_inodedeps_mountlist_callback,
4828 			&info, MNTSCAN_FORWARD|MNTSCAN_NOBUSY);
4829 	/*
4830 	 * Find the last inode in the block with dependencies.
4831 	 */
4832 	firstino = inodedep->id_ino & ~(INOPB(fs) - 1);
4833 	for (lastino = firstino + INOPB(fs) - 1; lastino > firstino; lastino--)
4834 		if (inodedep_lookup(fs, lastino, 0, &inodedep) != 0)
4835 			break;
4836 	/*
4837 	 * Asynchronously push all but the last inode with dependencies.
4838 	 * Synchronously push the last inode with dependencies to ensure
4839 	 * that the inode block gets written to free up the inodedeps.
4840 	 */
4841 	for (ino = firstino; ino <= lastino; ino++) {
4842 		if (inodedep_lookup(fs, ino, 0, &inodedep) == 0)
4843 			continue;
4844 		FREE_LOCK(&lk);
4845 		if ((error = VFS_VGET(info.mp, ino, &vp)) != 0) {
4846 			softdep_error("clear_inodedeps: vget", error);
4847 			return;
4848 		}
4849 		if (ino == lastino) {
4850 			if ((error = VOP_FSYNC(vp, MNT_WAIT, td)))
4851 				softdep_error("clear_inodedeps: fsync1", error);
4852 		} else {
4853 			if ((error = VOP_FSYNC(vp, MNT_NOWAIT, td)))
4854 				softdep_error("clear_inodedeps: fsync2", error);
4855 			drain_output(vp, 0);
4856 		}
4857 		vput(vp);
4858 		ACQUIRE_LOCK(&lk);
4859 	}
4860 	FREE_LOCK(&lk);
4861 }
4862 
4863 /*
4864  * Function to determine if the buffer has outstanding dependencies
4865  * that will cause a roll-back if the buffer is written. If wantcount
4866  * is set, return number of dependencies, otherwise just yes or no.
4867  */
4868 static int
4869 softdep_count_dependencies(bp, wantcount)
4870 	struct buf *bp;
4871 	int wantcount;
4872 {
4873 	struct worklist *wk;
4874 	struct inodedep *inodedep;
4875 	struct indirdep *indirdep;
4876 	struct allocindir *aip;
4877 	struct pagedep *pagedep;
4878 	struct diradd *dap;
4879 	int i, retval;
4880 
4881 	retval = 0;
4882 	ACQUIRE_LOCK(&lk);
4883 	LIST_FOREACH(wk, &bp->b_dep, wk_list) {
4884 		switch (wk->wk_type) {
4885 
4886 		case D_INODEDEP:
4887 			inodedep = WK_INODEDEP(wk);
4888 			if ((inodedep->id_state & DEPCOMPLETE) == 0) {
4889 				/* bitmap allocation dependency */
4890 				retval += 1;
4891 				if (!wantcount)
4892 					goto out;
4893 			}
4894 			if (TAILQ_FIRST(&inodedep->id_inoupdt)) {
4895 				/* direct block pointer dependency */
4896 				retval += 1;
4897 				if (!wantcount)
4898 					goto out;
4899 			}
4900 			continue;
4901 
4902 		case D_INDIRDEP:
4903 			indirdep = WK_INDIRDEP(wk);
4904 
4905 			LIST_FOREACH(aip, &indirdep->ir_deplisthd, ai_next) {
4906 				/* indirect block pointer dependency */
4907 				retval += 1;
4908 				if (!wantcount)
4909 					goto out;
4910 			}
4911 			continue;
4912 
4913 		case D_PAGEDEP:
4914 			pagedep = WK_PAGEDEP(wk);
4915 			for (i = 0; i < DAHASHSZ; i++) {
4916 
4917 				LIST_FOREACH(dap, &pagedep->pd_diraddhd[i], da_pdlist) {
4918 					/* directory entry dependency */
4919 					retval += 1;
4920 					if (!wantcount)
4921 						goto out;
4922 				}
4923 			}
4924 			continue;
4925 
4926 		case D_BMSAFEMAP:
4927 		case D_ALLOCDIRECT:
4928 		case D_ALLOCINDIR:
4929 		case D_MKDIR:
4930 			/* never a dependency on these blocks */
4931 			continue;
4932 
4933 		default:
4934 			FREE_LOCK(&lk);
4935 			panic("softdep_check_for_rollback: Unexpected type %s",
4936 			    TYPENAME(wk->wk_type));
4937 			/* NOTREACHED */
4938 		}
4939 	}
4940 out:
4941 	FREE_LOCK(&lk);
4942 	return retval;
4943 }
4944 
4945 /*
4946  * Acquire exclusive access to a buffer.
4947  * Must be called with splbio blocked.
4948  * Return 1 if buffer was acquired.
4949  */
4950 static int
4951 getdirtybuf(bpp, waitfor)
4952 	struct buf **bpp;
4953 	int waitfor;
4954 {
4955 	struct buf *bp;
4956 	int error;
4957 
4958 	for (;;) {
4959 		if ((bp = *bpp) == NULL)
4960 			return (0);
4961 		if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT) == 0) {
4962 			if ((bp->b_xflags & BX_BKGRDINPROG) == 0)
4963 				break;
4964 			BUF_UNLOCK(bp);
4965 			if (waitfor != MNT_WAIT)
4966 				return (0);
4967 			bp->b_xflags |= BX_BKGRDWAIT;
4968 			interlocked_sleep(&lk, SLEEP, &bp->b_xflags, 0,
4969 			    "getbuf", 0);
4970 			continue;
4971 		}
4972 		if (waitfor != MNT_WAIT)
4973 			return (0);
4974 		error = interlocked_sleep(&lk, LOCKBUF, bp,
4975 		    LK_EXCLUSIVE | LK_SLEEPFAIL, 0, 0);
4976 		if (error != ENOLCK) {
4977 			FREE_LOCK(&lk);
4978 			panic("getdirtybuf: inconsistent lock");
4979 		}
4980 	}
4981 	if ((bp->b_flags & B_DELWRI) == 0) {
4982 		BUF_UNLOCK(bp);
4983 		return (0);
4984 	}
4985 	bremfree(bp);
4986 	return (1);
4987 }
4988 
4989 /*
4990  * Wait for pending output on a vnode to complete.
4991  * Must be called with vnode locked.
4992  */
4993 static void
4994 drain_output(vp, islocked)
4995 	struct vnode *vp;
4996 	int islocked;
4997 {
4998 
4999 	if (!islocked)
5000 		ACQUIRE_LOCK(&lk);
5001 	while (vp->v_numoutput) {
5002 		vp->v_flag |= VBWAIT;
5003 		interlocked_sleep(&lk, SLEEP, (caddr_t)&vp->v_numoutput,
5004 		    0, "drainvp", 0);
5005 	}
5006 	if (!islocked)
5007 		FREE_LOCK(&lk);
5008 }
5009 
5010 /*
5011  * Called whenever a buffer that is being invalidated or reallocated
5012  * contains dependencies. This should only happen if an I/O error has
5013  * occurred. The routine is called with the buffer locked.
5014  */
5015 static void
5016 softdep_deallocate_dependencies(bp)
5017 	struct buf *bp;
5018 {
5019 
5020 	if ((bp->b_flags & B_ERROR) == 0)
5021 		panic("softdep_deallocate_dependencies: dangling deps");
5022 	softdep_error(bp->b_vp->v_mount->mnt_stat.f_mntfromname, bp->b_error);
5023 	panic("softdep_deallocate_dependencies: unrecovered I/O error");
5024 }
5025 
5026 /*
5027  * Function to handle asynchronous write errors in the filesystem.
5028  */
5029 void
5030 softdep_error(func, error)
5031 	char *func;
5032 	int error;
5033 {
5034 
5035 	/* XXX should do something better! */
5036 	printf("%s: got error %d while accessing filesystem\n", func, error);
5037 }
5038