xref: /dragonfly/sys/vfs/ufs/ffs_softdep.c (revision 1d1731fa)
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 1.11 2003/08/20 09:56:34 rob 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 "dir.h"
65 #include "quota.h"
66 #include "inode.h"
67 #include "ufsmount.h"
68 #include "fs.h"
69 #include "softdep.h"
70 #include "ffs_extern.h"
71 #include "ufs_extern.h"
72 
73 /*
74  * These definitions need to be adapted to the system to which
75  * this file is being ported.
76  */
77 /*
78  * malloc types defined for the softdep system.
79  */
80 MALLOC_DEFINE(M_PAGEDEP, "pagedep","File page dependencies");
81 MALLOC_DEFINE(M_INODEDEP, "inodedep","Inode dependencies");
82 MALLOC_DEFINE(M_NEWBLK, "newblk","New block allocation");
83 MALLOC_DEFINE(M_BMSAFEMAP, "bmsafemap","Block or frag allocated from cyl group map");
84 MALLOC_DEFINE(M_ALLOCDIRECT, "allocdirect","Block or frag dependency for an inode");
85 MALLOC_DEFINE(M_INDIRDEP, "indirdep","Indirect block dependencies");
86 MALLOC_DEFINE(M_ALLOCINDIR, "allocindir","Block dependency for an indirect block");
87 MALLOC_DEFINE(M_FREEFRAG, "freefrag","Previously used frag for an inode");
88 MALLOC_DEFINE(M_FREEBLKS, "freeblks","Blocks freed from an inode");
89 MALLOC_DEFINE(M_FREEFILE, "freefile","Inode deallocated");
90 MALLOC_DEFINE(M_DIRADD, "diradd","New directory entry");
91 MALLOC_DEFINE(M_MKDIR, "mkdir","New directory");
92 MALLOC_DEFINE(M_DIRREM, "dirrem","Directory entry deleted");
93 
94 #define M_SOFTDEP_FLAGS		(M_WAITOK | M_USE_RESERVE)
95 
96 #define	D_PAGEDEP	0
97 #define	D_INODEDEP	1
98 #define	D_NEWBLK	2
99 #define	D_BMSAFEMAP	3
100 #define	D_ALLOCDIRECT	4
101 #define	D_INDIRDEP	5
102 #define	D_ALLOCINDIR	6
103 #define	D_FREEFRAG	7
104 #define	D_FREEBLKS	8
105 #define	D_FREEFILE	9
106 #define	D_DIRADD	10
107 #define	D_MKDIR		11
108 #define	D_DIRREM	12
109 #define D_LAST		D_DIRREM
110 
111 /*
112  * translate from workitem type to memory type
113  * MUST match the defines above, such that memtype[D_XXX] == M_XXX
114  */
115 static struct malloc_type *memtype[] = {
116 	M_PAGEDEP,
117 	M_INODEDEP,
118 	M_NEWBLK,
119 	M_BMSAFEMAP,
120 	M_ALLOCDIRECT,
121 	M_INDIRDEP,
122 	M_ALLOCINDIR,
123 	M_FREEFRAG,
124 	M_FREEBLKS,
125 	M_FREEFILE,
126 	M_DIRADD,
127 	M_MKDIR,
128 	M_DIRREM
129 };
130 
131 #define DtoM(type) (memtype[type])
132 
133 /*
134  * Names of malloc types.
135  */
136 #define TYPENAME(type)  \
137 	((unsigned)(type) < D_LAST ? memtype[type]->ks_shortdesc : "???")
138 /*
139  * End system adaptaion definitions.
140  */
141 
142 /*
143  * Internal function prototypes.
144  */
145 static	void softdep_error (char *, int);
146 static	void drain_output (struct vnode *, int);
147 static	int getdirtybuf (struct buf **, int);
148 static	void clear_remove (struct thread *);
149 static	void clear_inodedeps (struct thread *);
150 static	int flush_pagedep_deps (struct vnode *, struct mount *,
151 	    struct diraddhd *);
152 static	int flush_inodedep_deps (struct fs *, ino_t);
153 static	int handle_written_filepage (struct pagedep *, struct buf *);
154 static  void diradd_inode_written (struct diradd *, struct inodedep *);
155 static	int handle_written_inodeblock (struct inodedep *, struct buf *);
156 static	void handle_allocdirect_partdone (struct allocdirect *);
157 static	void handle_allocindir_partdone (struct allocindir *);
158 static	void initiate_write_filepage (struct pagedep *, struct buf *);
159 static	void handle_written_mkdir (struct mkdir *, int);
160 static	void initiate_write_inodeblock (struct inodedep *, struct buf *);
161 static	void handle_workitem_freefile (struct freefile *);
162 static	void handle_workitem_remove (struct dirrem *);
163 static	struct dirrem *newdirrem (struct buf *, struct inode *,
164 	    struct inode *, int, struct dirrem **);
165 static	void free_diradd (struct diradd *);
166 static	void free_allocindir (struct allocindir *, struct inodedep *);
167 static	int indir_trunc (struct inode *, ufs_daddr_t, int, ufs_lbn_t,
168 	    long *);
169 static	void deallocate_dependencies (struct buf *, struct inodedep *);
170 static	void free_allocdirect (struct allocdirectlst *,
171 	    struct allocdirect *, int);
172 static	int check_inode_unwritten (struct inodedep *);
173 static	int free_inodedep (struct inodedep *);
174 static	void handle_workitem_freeblocks (struct freeblks *);
175 static	void merge_inode_lists (struct inodedep *);
176 static	void setup_allocindir_phase2 (struct buf *, struct inode *,
177 	    struct allocindir *);
178 static	struct allocindir *newallocindir (struct inode *, int, ufs_daddr_t,
179 	    ufs_daddr_t);
180 static	void handle_workitem_freefrag (struct freefrag *);
181 static	struct freefrag *newfreefrag (struct inode *, ufs_daddr_t, long);
182 static	void allocdirect_merge (struct allocdirectlst *,
183 	    struct allocdirect *, struct allocdirect *);
184 static	struct bmsafemap *bmsafemap_lookup (struct buf *);
185 static	int newblk_lookup (struct fs *, ufs_daddr_t, int,
186 	    struct newblk **);
187 static	int inodedep_lookup (struct fs *, ino_t, int, struct inodedep **);
188 static	int pagedep_lookup (struct inode *, ufs_lbn_t, int,
189 	    struct pagedep **);
190 static	void pause_timer (void *);
191 static	int request_cleanup (int, int);
192 static	int process_worklist_item (struct mount *, int);
193 static	void add_to_worklist (struct worklist *);
194 
195 /*
196  * Exported softdep operations.
197  */
198 static	void softdep_disk_io_initiation (struct buf *);
199 static	void softdep_disk_write_complete (struct buf *);
200 static	void softdep_deallocate_dependencies (struct buf *);
201 static	int softdep_fsync (struct vnode *);
202 static	int softdep_process_worklist (struct mount *);
203 static	void softdep_move_dependencies (struct buf *, struct buf *);
204 static	int softdep_count_dependencies (struct buf *bp, int);
205 
206 struct bio_ops bioops = {
207 	softdep_disk_io_initiation,		/* io_start */
208 	softdep_disk_write_complete,		/* io_complete */
209 	softdep_deallocate_dependencies,	/* io_deallocate */
210 	softdep_fsync,				/* io_fsync */
211 	softdep_process_worklist,		/* io_sync */
212 	softdep_move_dependencies,		/* io_movedeps */
213 	softdep_count_dependencies,		/* io_countdeps */
214 };
215 
216 /*
217  * Locking primitives.
218  *
219  * For a uniprocessor, all we need to do is protect against disk
220  * interrupts. For a multiprocessor, this lock would have to be
221  * a mutex. A single mutex is used throughout this file, though
222  * finer grain locking could be used if contention warranted it.
223  *
224  * For a multiprocessor, the sleep call would accept a lock and
225  * release it after the sleep processing was complete. In a uniprocessor
226  * implementation there is no such interlock, so we simple mark
227  * the places where it needs to be done with the `interlocked' form
228  * of the lock calls. Since the uniprocessor sleep already interlocks
229  * the spl, there is nothing that really needs to be done.
230  */
231 #ifndef /* NOT */ DEBUG
232 static struct lockit {
233 	int	lkt_spl;
234 } lk = { 0 };
235 #define ACQUIRE_LOCK(lk)		(lk)->lkt_spl = splbio()
236 #define FREE_LOCK(lk)			splx((lk)->lkt_spl)
237 
238 #else /* DEBUG */
239 #define NOHOLDER	((struct thread *)-1)
240 #define SPECIAL_FLAG	((struct thread *)-2)
241 static struct lockit {
242 	int	lkt_spl;
243 	struct thread *lkt_held;
244 } lk = { 0, NOHOLDER };
245 static int lockcnt;
246 
247 static	void acquire_lock (struct lockit *);
248 static	void free_lock (struct lockit *);
249 void	softdep_panic (char *);
250 
251 #define ACQUIRE_LOCK(lk)		acquire_lock(lk)
252 #define FREE_LOCK(lk)			free_lock(lk)
253 
254 static void
255 acquire_lock(lk)
256 	struct lockit *lk;
257 {
258 	thread_t holder;
259 
260 	if (lk->lkt_held != NOHOLDER) {
261 		holder = lk->lkt_held;
262 		FREE_LOCK(lk);
263 		if (holder == curthread)
264 			panic("softdep_lock: locking against myself");
265 		else
266 			panic("softdep_lock: lock held by %p", holder);
267 	}
268 	lk->lkt_spl = splbio();
269 	lk->lkt_held = curthread;
270 	lockcnt++;
271 }
272 
273 static void
274 free_lock(lk)
275 	struct lockit *lk;
276 {
277 
278 	if (lk->lkt_held == NOHOLDER)
279 		panic("softdep_unlock: lock not held");
280 	lk->lkt_held = NOHOLDER;
281 	splx(lk->lkt_spl);
282 }
283 
284 /*
285  * Function to release soft updates lock and panic.
286  */
287 void
288 softdep_panic(msg)
289 	char *msg;
290 {
291 
292 	if (lk.lkt_held != NOHOLDER)
293 		FREE_LOCK(&lk);
294 	panic(msg);
295 }
296 #endif /* DEBUG */
297 
298 static	int interlocked_sleep (struct lockit *, int, void *, int,
299 	    const char *, int);
300 
301 /*
302  * When going to sleep, we must save our SPL so that it does
303  * not get lost if some other process uses the lock while we
304  * are sleeping. We restore it after we have slept. This routine
305  * wraps the interlocking with functions that sleep. The list
306  * below enumerates the available set of operations.
307  */
308 #define	UNKNOWN		0
309 #define	SLEEP		1
310 #define	LOCKBUF		2
311 
312 static int
313 interlocked_sleep(lk, op, ident, flags, wmesg, timo)
314 	struct lockit *lk;
315 	int op;
316 	void *ident;
317 	int flags;
318 	const char *wmesg;
319 	int timo;
320 {
321 	thread_t holder;
322 	int s, retval;
323 
324 	s = lk->lkt_spl;
325 #	ifdef DEBUG
326 	if (lk->lkt_held == NOHOLDER)
327 		panic("interlocked_sleep: lock not held");
328 	lk->lkt_held = NOHOLDER;
329 #	endif /* DEBUG */
330 	switch (op) {
331 	case SLEEP:
332 		retval = tsleep(ident, flags, wmesg, timo);
333 		break;
334 	case LOCKBUF:
335 		retval = BUF_LOCK((struct buf *)ident, flags);
336 		break;
337 	default:
338 		panic("interlocked_sleep: unknown operation");
339 	}
340 #	ifdef DEBUG
341 	if (lk->lkt_held != NOHOLDER) {
342 		holder = lk->lkt_held;
343 		FREE_LOCK(lk);
344 		if (holder == curthread)
345 			panic("interlocked_sleep: locking against self");
346 		else
347 			panic("interlocked_sleep: lock held by %p", holder);
348 	}
349 	lk->lkt_held = curthread;
350 	lockcnt++;
351 #	endif /* DEBUG */
352 	lk->lkt_spl = s;
353 	return (retval);
354 }
355 
356 /*
357  * Place holder for real semaphores.
358  */
359 struct sema {
360 	int	value;
361 	thread_t holder;
362 	char	*name;
363 	int	prio;
364 	int	timo;
365 };
366 static	void sema_init (struct sema *, char *, int, int);
367 static	int sema_get (struct sema *, struct lockit *);
368 static	void sema_release (struct sema *);
369 
370 static void
371 sema_init(semap, name, prio, timo)
372 	struct sema *semap;
373 	char *name;
374 	int prio, timo;
375 {
376 
377 	semap->holder = NOHOLDER;
378 	semap->value = 0;
379 	semap->name = name;
380 	semap->prio = prio;
381 	semap->timo = timo;
382 }
383 
384 static int
385 sema_get(semap, interlock)
386 	struct sema *semap;
387 	struct lockit *interlock;
388 {
389 
390 	if (semap->value++ > 0) {
391 		if (interlock != NULL) {
392 			interlocked_sleep(interlock, SLEEP, (caddr_t)semap,
393 			    semap->prio, semap->name, semap->timo);
394 			FREE_LOCK(interlock);
395 		} else {
396 			tsleep((caddr_t)semap, semap->prio, semap->name,
397 			    semap->timo);
398 		}
399 		return (0);
400 	}
401 	semap->holder = curthread;
402 	if (interlock != NULL)
403 		FREE_LOCK(interlock);
404 	return (1);
405 }
406 
407 static void
408 sema_release(semap)
409 	struct sema *semap;
410 {
411 
412 	if (semap->value <= 0 || semap->holder != curthread) {
413 		if (lk.lkt_held != NOHOLDER)
414 			FREE_LOCK(&lk);
415 		panic("sema_release: not held");
416 	}
417 	if (--semap->value > 0) {
418 		semap->value = 0;
419 		wakeup(semap);
420 	}
421 	semap->holder = NOHOLDER;
422 }
423 
424 /*
425  * Worklist queue management.
426  * These routines require that the lock be held.
427  */
428 #ifndef /* NOT */ DEBUG
429 #define WORKLIST_INSERT(head, item) do {	\
430 	(item)->wk_state |= ONWORKLIST;		\
431 	LIST_INSERT_HEAD(head, item, wk_list);	\
432 } while (0)
433 #define WORKLIST_REMOVE(item) do {		\
434 	(item)->wk_state &= ~ONWORKLIST;	\
435 	LIST_REMOVE(item, wk_list);		\
436 } while (0)
437 #define WORKITEM_FREE(item, type) FREE(item, DtoM(type))
438 
439 #else /* DEBUG */
440 static	void worklist_insert (struct workhead *, struct worklist *);
441 static	void worklist_remove (struct worklist *);
442 static	void workitem_free (struct worklist *, int);
443 
444 #define WORKLIST_INSERT(head, item) worklist_insert(head, item)
445 #define WORKLIST_REMOVE(item) worklist_remove(item)
446 #define WORKITEM_FREE(item, type) workitem_free((struct worklist *)item, type)
447 
448 static void
449 worklist_insert(head, item)
450 	struct workhead *head;
451 	struct worklist *item;
452 {
453 
454 	if (lk.lkt_held == NOHOLDER)
455 		panic("worklist_insert: lock not held");
456 	if (item->wk_state & ONWORKLIST) {
457 		FREE_LOCK(&lk);
458 		panic("worklist_insert: already on list");
459 	}
460 	item->wk_state |= ONWORKLIST;
461 	LIST_INSERT_HEAD(head, item, wk_list);
462 }
463 
464 static void
465 worklist_remove(item)
466 	struct worklist *item;
467 {
468 
469 	if (lk.lkt_held == NOHOLDER)
470 		panic("worklist_remove: lock not held");
471 	if ((item->wk_state & ONWORKLIST) == 0) {
472 		FREE_LOCK(&lk);
473 		panic("worklist_remove: not on list");
474 	}
475 	item->wk_state &= ~ONWORKLIST;
476 	LIST_REMOVE(item, wk_list);
477 }
478 
479 static void
480 workitem_free(item, type)
481 	struct worklist *item;
482 	int type;
483 {
484 
485 	if (item->wk_state & ONWORKLIST) {
486 		if (lk.lkt_held != NOHOLDER)
487 			FREE_LOCK(&lk);
488 		panic("workitem_free: still on list");
489 	}
490 	if (item->wk_type != type) {
491 		if (lk.lkt_held != NOHOLDER)
492 			FREE_LOCK(&lk);
493 		panic("workitem_free: type mismatch");
494 	}
495 	FREE(item, DtoM(type));
496 }
497 #endif /* DEBUG */
498 
499 /*
500  * Workitem queue management
501  */
502 static struct workhead softdep_workitem_pending;
503 static int num_on_worklist;	/* number of worklist items to be processed */
504 static int softdep_worklist_busy; /* 1 => trying to do unmount */
505 static int softdep_worklist_req; /* serialized waiters */
506 static int max_softdeps;	/* maximum number of structs before slowdown */
507 static int tickdelay = 2;	/* number of ticks to pause during slowdown */
508 static int *stat_countp;	/* statistic to count in proc_waiting timeout */
509 static int proc_waiting;	/* tracks whether we have a timeout posted */
510 static struct callout_handle handle; /* handle on posted proc_waiting timeout */
511 static struct thread *filesys_syncer; /* proc of filesystem syncer process */
512 static int req_clear_inodedeps;	/* syncer process flush some inodedeps */
513 #define FLUSH_INODES	1
514 static int req_clear_remove;	/* syncer process flush some freeblks */
515 #define FLUSH_REMOVE	2
516 /*
517  * runtime statistics
518  */
519 static int stat_worklist_push;	/* number of worklist cleanups */
520 static int stat_blk_limit_push;	/* number of times block limit neared */
521 static int stat_ino_limit_push;	/* number of times inode limit neared */
522 static int stat_blk_limit_hit;	/* number of times block slowdown imposed */
523 static int stat_ino_limit_hit;	/* number of times inode slowdown imposed */
524 static int stat_sync_limit_hit;	/* number of synchronous slowdowns imposed */
525 static int stat_indir_blk_ptrs;	/* bufs redirtied as indir ptrs not written */
526 static int stat_inode_bitmap;	/* bufs redirtied as inode bitmap not written */
527 static int stat_direct_blk_ptrs;/* bufs redirtied as direct ptrs not written */
528 static int stat_dir_entry;	/* bufs redirtied as dir entry cannot write */
529 #ifdef DEBUG
530 #include <vm/vm.h>
531 #include <sys/sysctl.h>
532 SYSCTL_INT(_debug, OID_AUTO, max_softdeps, CTLFLAG_RW, &max_softdeps, 0, "");
533 SYSCTL_INT(_debug, OID_AUTO, tickdelay, CTLFLAG_RW, &tickdelay, 0, "");
534 SYSCTL_INT(_debug, OID_AUTO, worklist_push, CTLFLAG_RW, &stat_worklist_push, 0,"");
535 SYSCTL_INT(_debug, OID_AUTO, blk_limit_push, CTLFLAG_RW, &stat_blk_limit_push, 0,"");
536 SYSCTL_INT(_debug, OID_AUTO, ino_limit_push, CTLFLAG_RW, &stat_ino_limit_push, 0,"");
537 SYSCTL_INT(_debug, OID_AUTO, blk_limit_hit, CTLFLAG_RW, &stat_blk_limit_hit, 0, "");
538 SYSCTL_INT(_debug, OID_AUTO, ino_limit_hit, CTLFLAG_RW, &stat_ino_limit_hit, 0, "");
539 SYSCTL_INT(_debug, OID_AUTO, sync_limit_hit, CTLFLAG_RW, &stat_sync_limit_hit, 0, "");
540 SYSCTL_INT(_debug, OID_AUTO, indir_blk_ptrs, CTLFLAG_RW, &stat_indir_blk_ptrs, 0, "");
541 SYSCTL_INT(_debug, OID_AUTO, inode_bitmap, CTLFLAG_RW, &stat_inode_bitmap, 0, "");
542 SYSCTL_INT(_debug, OID_AUTO, direct_blk_ptrs, CTLFLAG_RW, &stat_direct_blk_ptrs, 0, "");
543 SYSCTL_INT(_debug, OID_AUTO, dir_entry, CTLFLAG_RW, &stat_dir_entry, 0, "");
544 #endif /* DEBUG */
545 
546 /*
547  * Add an item to the end of the work queue.
548  * This routine requires that the lock be held.
549  * This is the only routine that adds items to the list.
550  * The following routine is the only one that removes items
551  * and does so in order from first to last.
552  */
553 static void
554 add_to_worklist(wk)
555 	struct worklist *wk;
556 {
557 	static struct worklist *worklist_tail;
558 
559 	if (wk->wk_state & ONWORKLIST) {
560 		if (lk.lkt_held != NOHOLDER)
561 			FREE_LOCK(&lk);
562 		panic("add_to_worklist: already on list");
563 	}
564 	wk->wk_state |= ONWORKLIST;
565 	if (LIST_FIRST(&softdep_workitem_pending) == NULL)
566 		LIST_INSERT_HEAD(&softdep_workitem_pending, wk, wk_list);
567 	else
568 		LIST_INSERT_AFTER(worklist_tail, wk, wk_list);
569 	worklist_tail = wk;
570 	num_on_worklist += 1;
571 }
572 
573 /*
574  * Process that runs once per second to handle items in the background queue.
575  *
576  * Note that we ensure that everything is done in the order in which they
577  * appear in the queue. The code below depends on this property to ensure
578  * that blocks of a file are freed before the inode itself is freed. This
579  * ordering ensures that no new <vfsid, inum, lbn> triples will be generated
580  * until all the old ones have been purged from the dependency lists.
581  */
582 static int
583 softdep_process_worklist(matchmnt)
584 	struct mount *matchmnt;
585 {
586 	thread_t td = curthread;
587 	int matchcnt, loopcount;
588 	long starttime;
589 
590 	/*
591 	 * Record the process identifier of our caller so that we can give
592 	 * this process preferential treatment in request_cleanup below.
593 	 */
594 	filesys_syncer = td;
595 	matchcnt = 0;
596 
597 	/*
598 	 * There is no danger of having multiple processes run this
599 	 * code, but we have to single-thread it when softdep_flushfiles()
600 	 * is in operation to get an accurate count of the number of items
601 	 * related to its mount point that are in the list.
602 	 */
603 	if (matchmnt == NULL) {
604 		if (softdep_worklist_busy < 0)
605 			return(-1);
606 		softdep_worklist_busy += 1;
607 	}
608 
609 	/*
610 	 * If requested, try removing inode or removal dependencies.
611 	 */
612 	if (req_clear_inodedeps) {
613 		clear_inodedeps(td);
614 		req_clear_inodedeps -= 1;
615 		wakeup_one(&proc_waiting);
616 	}
617 	if (req_clear_remove) {
618 		clear_remove(td);
619 		req_clear_remove -= 1;
620 		wakeup_one(&proc_waiting);
621 	}
622 	loopcount = 1;
623 	starttime = time_second;
624 	while (num_on_worklist > 0) {
625 		matchcnt += process_worklist_item(matchmnt, 0);
626 
627 		/*
628 		 * If a umount operation wants to run the worklist
629 		 * accurately, abort.
630 		 */
631 		if (softdep_worklist_req && matchmnt == NULL) {
632 			matchcnt = -1;
633 			break;
634 		}
635 
636 		/*
637 		 * If requested, try removing inode or removal dependencies.
638 		 */
639 		if (req_clear_inodedeps) {
640 			clear_inodedeps(td);
641 			req_clear_inodedeps -= 1;
642 			wakeup_one(&proc_waiting);
643 		}
644 		if (req_clear_remove) {
645 			clear_remove(td);
646 			req_clear_remove -= 1;
647 			wakeup_one(&proc_waiting);
648 		}
649 		/*
650 		 * We do not generally want to stop for buffer space, but if
651 		 * we are really being a buffer hog, we will stop and wait.
652 		 */
653 		if (loopcount++ % 128 == 0)
654 			bwillwrite();
655 		/*
656 		 * Never allow processing to run for more than one
657 		 * second. Otherwise the other syncer tasks may get
658 		 * excessively backlogged.
659 		 */
660 		if (starttime != time_second && matchmnt == NULL) {
661 			matchcnt = -1;
662 			break;
663 		}
664 	}
665 	if (matchmnt == NULL) {
666 		--softdep_worklist_busy;
667 		if (softdep_worklist_req && softdep_worklist_busy == 0)
668 			wakeup(&softdep_worklist_req);
669 	}
670 	return (matchcnt);
671 }
672 
673 /*
674  * Process one item on the worklist.
675  */
676 static int
677 process_worklist_item(matchmnt, flags)
678 	struct mount *matchmnt;
679 	int flags;
680 {
681 	struct worklist *wk;
682 	struct dirrem *dirrem;
683 	struct fs *matchfs;
684 	struct vnode *vp;
685 	int matchcnt = 0;
686 
687 	matchfs = NULL;
688 	if (matchmnt != NULL)
689 		matchfs = VFSTOUFS(matchmnt)->um_fs;
690 	ACQUIRE_LOCK(&lk);
691 	/*
692 	 * Normally we just process each item on the worklist in order.
693 	 * However, if we are in a situation where we cannot lock any
694 	 * inodes, we have to skip over any dirrem requests whose
695 	 * vnodes are resident and locked.
696 	 */
697 	LIST_FOREACH(wk, &softdep_workitem_pending, wk_list) {
698 		if ((flags & LK_NOWAIT) == 0 || wk->wk_type != D_DIRREM)
699 			break;
700 		dirrem = WK_DIRREM(wk);
701 		vp = ufs_ihashlookup(VFSTOUFS(dirrem->dm_mnt)->um_dev,
702 		    dirrem->dm_oldinum);
703 		if (vp == NULL || !VOP_ISLOCKED(vp, curthread))
704 			break;
705 	}
706 	if (wk == 0) {
707 		FREE_LOCK(&lk);
708 		return (0);
709 	}
710 	WORKLIST_REMOVE(wk);
711 	num_on_worklist -= 1;
712 	FREE_LOCK(&lk);
713 	switch (wk->wk_type) {
714 
715 	case D_DIRREM:
716 		/* removal of a directory entry */
717 		if (WK_DIRREM(wk)->dm_mnt == matchmnt)
718 			matchcnt += 1;
719 		handle_workitem_remove(WK_DIRREM(wk));
720 		break;
721 
722 	case D_FREEBLKS:
723 		/* releasing blocks and/or fragments from a file */
724 		if (WK_FREEBLKS(wk)->fb_fs == matchfs)
725 			matchcnt += 1;
726 		handle_workitem_freeblocks(WK_FREEBLKS(wk));
727 		break;
728 
729 	case D_FREEFRAG:
730 		/* releasing a fragment when replaced as a file grows */
731 		if (WK_FREEFRAG(wk)->ff_fs == matchfs)
732 			matchcnt += 1;
733 		handle_workitem_freefrag(WK_FREEFRAG(wk));
734 		break;
735 
736 	case D_FREEFILE:
737 		/* releasing an inode when its link count drops to 0 */
738 		if (WK_FREEFILE(wk)->fx_fs == matchfs)
739 			matchcnt += 1;
740 		handle_workitem_freefile(WK_FREEFILE(wk));
741 		break;
742 
743 	default:
744 		panic("%s_process_worklist: Unknown type %s",
745 		    "softdep", TYPENAME(wk->wk_type));
746 		/* NOTREACHED */
747 	}
748 	return (matchcnt);
749 }
750 
751 /*
752  * Move dependencies from one buffer to another.
753  */
754 static void
755 softdep_move_dependencies(oldbp, newbp)
756 	struct buf *oldbp;
757 	struct buf *newbp;
758 {
759 	struct worklist *wk, *wktail;
760 
761 	if (LIST_FIRST(&newbp->b_dep) != NULL)
762 		panic("softdep_move_dependencies: need merge code");
763 	wktail = 0;
764 	ACQUIRE_LOCK(&lk);
765 	while ((wk = LIST_FIRST(&oldbp->b_dep)) != NULL) {
766 		LIST_REMOVE(wk, wk_list);
767 		if (wktail == 0)
768 			LIST_INSERT_HEAD(&newbp->b_dep, wk, wk_list);
769 		else
770 			LIST_INSERT_AFTER(wktail, wk, wk_list);
771 		wktail = wk;
772 	}
773 	FREE_LOCK(&lk);
774 }
775 
776 /*
777  * Purge the work list of all items associated with a particular mount point.
778  */
779 int
780 softdep_flushfiles(struct mount *oldmnt, int flags, struct thread *td)
781 {
782 	struct vnode *devvp;
783 	int error, loopcnt;
784 
785 	/*
786 	 * Await our turn to clear out the queue, then serialize access.
787 	 */
788 	while (softdep_worklist_busy != 0) {
789 		softdep_worklist_req += 1;
790 		tsleep(&softdep_worklist_req, 0, "softflush", 0);
791 		softdep_worklist_req -= 1;
792 	}
793 	softdep_worklist_busy = -1;
794 
795 	if ((error = ffs_flushfiles(oldmnt, flags, td)) != 0) {
796 		softdep_worklist_busy = 0;
797 		if (softdep_worklist_req)
798 			wakeup(&softdep_worklist_req);
799 		return (error);
800 	}
801 	/*
802 	 * Alternately flush the block device associated with the mount
803 	 * point and process any dependencies that the flushing
804 	 * creates. In theory, this loop can happen at most twice,
805 	 * but we give it a few extra just to be sure.
806 	 */
807 	devvp = VFSTOUFS(oldmnt)->um_devvp;
808 	for (loopcnt = 10; loopcnt > 0; ) {
809 		if (softdep_process_worklist(oldmnt) == 0) {
810 			loopcnt--;
811 			/*
812 			 * Do another flush in case any vnodes were brought in
813 			 * as part of the cleanup operations.
814 			 */
815 			if ((error = ffs_flushfiles(oldmnt, flags, td)) != 0)
816 				break;
817 			/*
818 			 * If we still found nothing to do, we are really done.
819 			 */
820 			if (softdep_process_worklist(oldmnt) == 0)
821 				break;
822 		}
823 		vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY, td);
824 		error = VOP_FSYNC(devvp, MNT_WAIT, td);
825 		VOP_UNLOCK(devvp, 0, td);
826 		if (error)
827 			break;
828 	}
829 	softdep_worklist_busy = 0;
830 	if (softdep_worklist_req)
831 		wakeup(&softdep_worklist_req);
832 
833 	/*
834 	 * If we are unmounting then it is an error to fail. If we
835 	 * are simply trying to downgrade to read-only, then filesystem
836 	 * activity can keep us busy forever, so we just fail with EBUSY.
837 	 */
838 	if (loopcnt == 0) {
839 		if (oldmnt->mnt_kern_flag & MNTK_UNMOUNT)
840 			panic("softdep_flushfiles: looping");
841 		error = EBUSY;
842 	}
843 	return (error);
844 }
845 
846 /*
847  * Structure hashing.
848  *
849  * There are three types of structures that can be looked up:
850  *	1) pagedep structures identified by mount point, inode number,
851  *	   and logical block.
852  *	2) inodedep structures identified by mount point and inode number.
853  *	3) newblk structures identified by mount point and
854  *	   physical block number.
855  *
856  * The "pagedep" and "inodedep" dependency structures are hashed
857  * separately from the file blocks and inodes to which they correspond.
858  * This separation helps when the in-memory copy of an inode or
859  * file block must be replaced. It also obviates the need to access
860  * an inode or file page when simply updating (or de-allocating)
861  * dependency structures. Lookup of newblk structures is needed to
862  * find newly allocated blocks when trying to associate them with
863  * their allocdirect or allocindir structure.
864  *
865  * The lookup routines optionally create and hash a new instance when
866  * an existing entry is not found.
867  */
868 #define DEPALLOC	0x0001	/* allocate structure if lookup fails */
869 #define NODELAY		0x0002	/* cannot do background work */
870 
871 /*
872  * Structures and routines associated with pagedep caching.
873  */
874 LIST_HEAD(pagedep_hashhead, pagedep) *pagedep_hashtbl;
875 u_long	pagedep_hash;		/* size of hash table - 1 */
876 #define	PAGEDEP_HASH(mp, inum, lbn) \
877 	(&pagedep_hashtbl[((((register_t)(mp)) >> 13) + (inum) + (lbn)) & \
878 	    pagedep_hash])
879 static struct sema pagedep_in_progress;
880 
881 /*
882  * Look up a pagedep. Return 1 if found, 0 if not found.
883  * If not found, allocate if DEPALLOC flag is passed.
884  * Found or allocated entry is returned in pagedeppp.
885  * This routine must be called with splbio interrupts blocked.
886  */
887 static int
888 pagedep_lookup(ip, lbn, flags, pagedeppp)
889 	struct inode *ip;
890 	ufs_lbn_t lbn;
891 	int flags;
892 	struct pagedep **pagedeppp;
893 {
894 	struct pagedep *pagedep;
895 	struct pagedep_hashhead *pagedephd;
896 	struct mount *mp;
897 	int i;
898 
899 #ifdef DEBUG
900 	if (lk.lkt_held == NOHOLDER)
901 		panic("pagedep_lookup: lock not held");
902 #endif
903 	mp = ITOV(ip)->v_mount;
904 	pagedephd = PAGEDEP_HASH(mp, ip->i_number, lbn);
905 top:
906 	LIST_FOREACH(pagedep, pagedephd, pd_hash)
907 		if (ip->i_number == pagedep->pd_ino &&
908 		    lbn == pagedep->pd_lbn &&
909 		    mp == pagedep->pd_mnt)
910 			break;
911 	if (pagedep) {
912 		*pagedeppp = pagedep;
913 		return (1);
914 	}
915 	if ((flags & DEPALLOC) == 0) {
916 		*pagedeppp = NULL;
917 		return (0);
918 	}
919 	if (sema_get(&pagedep_in_progress, &lk) == 0) {
920 		ACQUIRE_LOCK(&lk);
921 		goto top;
922 	}
923 	MALLOC(pagedep, struct pagedep *, sizeof(struct pagedep), M_PAGEDEP,
924 		M_SOFTDEP_FLAGS);
925 	bzero(pagedep, sizeof(struct pagedep));
926 	pagedep->pd_list.wk_type = D_PAGEDEP;
927 	pagedep->pd_mnt = mp;
928 	pagedep->pd_ino = ip->i_number;
929 	pagedep->pd_lbn = lbn;
930 	LIST_INIT(&pagedep->pd_dirremhd);
931 	LIST_INIT(&pagedep->pd_pendinghd);
932 	for (i = 0; i < DAHASHSZ; i++)
933 		LIST_INIT(&pagedep->pd_diraddhd[i]);
934 	ACQUIRE_LOCK(&lk);
935 	LIST_INSERT_HEAD(pagedephd, pagedep, pd_hash);
936 	sema_release(&pagedep_in_progress);
937 	*pagedeppp = pagedep;
938 	return (0);
939 }
940 
941 /*
942  * Structures and routines associated with inodedep caching.
943  */
944 LIST_HEAD(inodedep_hashhead, inodedep) *inodedep_hashtbl;
945 static u_long	inodedep_hash;	/* size of hash table - 1 */
946 static long	num_inodedep;	/* number of inodedep allocated */
947 #define	INODEDEP_HASH(fs, inum) \
948       (&inodedep_hashtbl[((((register_t)(fs)) >> 13) + (inum)) & inodedep_hash])
949 static struct sema inodedep_in_progress;
950 
951 /*
952  * Look up a inodedep. Return 1 if found, 0 if not found.
953  * If not found, allocate if DEPALLOC flag is passed.
954  * Found or allocated entry is returned in inodedeppp.
955  * This routine must be called with splbio interrupts blocked.
956  */
957 static int
958 inodedep_lookup(fs, inum, flags, inodedeppp)
959 	struct fs *fs;
960 	ino_t inum;
961 	int flags;
962 	struct inodedep **inodedeppp;
963 {
964 	struct inodedep *inodedep;
965 	struct inodedep_hashhead *inodedephd;
966 	int firsttry;
967 
968 #ifdef DEBUG
969 	if (lk.lkt_held == NOHOLDER)
970 		panic("inodedep_lookup: lock not held");
971 #endif
972 	firsttry = 1;
973 	inodedephd = INODEDEP_HASH(fs, inum);
974 top:
975 	LIST_FOREACH(inodedep, inodedephd, id_hash)
976 		if (inum == inodedep->id_ino && fs == inodedep->id_fs)
977 			break;
978 	if (inodedep) {
979 		*inodedeppp = inodedep;
980 		return (1);
981 	}
982 	if ((flags & DEPALLOC) == 0) {
983 		*inodedeppp = NULL;
984 		return (0);
985 	}
986 	/*
987 	 * If we are over our limit, try to improve the situation.
988 	 */
989 	if (num_inodedep > max_softdeps && firsttry &&
990 	    speedup_syncer() == 0 && (flags & NODELAY) == 0 &&
991 	    request_cleanup(FLUSH_INODES, 1)) {
992 		firsttry = 0;
993 		goto top;
994 	}
995 	if (sema_get(&inodedep_in_progress, &lk) == 0) {
996 		ACQUIRE_LOCK(&lk);
997 		goto top;
998 	}
999 	num_inodedep += 1;
1000 	MALLOC(inodedep, struct inodedep *, sizeof(struct inodedep),
1001 		M_INODEDEP, M_SOFTDEP_FLAGS);
1002 	inodedep->id_list.wk_type = D_INODEDEP;
1003 	inodedep->id_fs = fs;
1004 	inodedep->id_ino = inum;
1005 	inodedep->id_state = ALLCOMPLETE;
1006 	inodedep->id_nlinkdelta = 0;
1007 	inodedep->id_savedino = NULL;
1008 	inodedep->id_savedsize = -1;
1009 	inodedep->id_buf = NULL;
1010 	LIST_INIT(&inodedep->id_pendinghd);
1011 	LIST_INIT(&inodedep->id_inowait);
1012 	LIST_INIT(&inodedep->id_bufwait);
1013 	TAILQ_INIT(&inodedep->id_inoupdt);
1014 	TAILQ_INIT(&inodedep->id_newinoupdt);
1015 	ACQUIRE_LOCK(&lk);
1016 	LIST_INSERT_HEAD(inodedephd, inodedep, id_hash);
1017 	sema_release(&inodedep_in_progress);
1018 	*inodedeppp = inodedep;
1019 	return (0);
1020 }
1021 
1022 /*
1023  * Structures and routines associated with newblk caching.
1024  */
1025 LIST_HEAD(newblk_hashhead, newblk) *newblk_hashtbl;
1026 u_long	newblk_hash;		/* size of hash table - 1 */
1027 #define	NEWBLK_HASH(fs, inum) \
1028 	(&newblk_hashtbl[((((register_t)(fs)) >> 13) + (inum)) & newblk_hash])
1029 static struct sema newblk_in_progress;
1030 
1031 /*
1032  * Look up a newblk. Return 1 if found, 0 if not found.
1033  * If not found, allocate if DEPALLOC flag is passed.
1034  * Found or allocated entry is returned in newblkpp.
1035  */
1036 static int
1037 newblk_lookup(fs, newblkno, flags, newblkpp)
1038 	struct fs *fs;
1039 	ufs_daddr_t newblkno;
1040 	int flags;
1041 	struct newblk **newblkpp;
1042 {
1043 	struct newblk *newblk;
1044 	struct newblk_hashhead *newblkhd;
1045 
1046 	newblkhd = NEWBLK_HASH(fs, newblkno);
1047 top:
1048 	LIST_FOREACH(newblk, newblkhd, nb_hash)
1049 		if (newblkno == newblk->nb_newblkno && fs == newblk->nb_fs)
1050 			break;
1051 	if (newblk) {
1052 		*newblkpp = newblk;
1053 		return (1);
1054 	}
1055 	if ((flags & DEPALLOC) == 0) {
1056 		*newblkpp = NULL;
1057 		return (0);
1058 	}
1059 	if (sema_get(&newblk_in_progress, 0) == 0)
1060 		goto top;
1061 	MALLOC(newblk, struct newblk *, sizeof(struct newblk),
1062 		M_NEWBLK, M_SOFTDEP_FLAGS);
1063 	newblk->nb_state = 0;
1064 	newblk->nb_fs = fs;
1065 	newblk->nb_newblkno = newblkno;
1066 	LIST_INSERT_HEAD(newblkhd, newblk, nb_hash);
1067 	sema_release(&newblk_in_progress);
1068 	*newblkpp = newblk;
1069 	return (0);
1070 }
1071 
1072 /*
1073  * Executed during filesystem system initialization before
1074  * mounting any file systems.
1075  */
1076 void
1077 softdep_initialize()
1078 {
1079 
1080 	LIST_INIT(&mkdirlisthd);
1081 	LIST_INIT(&softdep_workitem_pending);
1082 	max_softdeps = min(desiredvnodes * 8,
1083 		M_INODEDEP->ks_limit / (2 * sizeof(struct inodedep)));
1084 	pagedep_hashtbl = hashinit(desiredvnodes / 5, M_PAGEDEP,
1085 	    &pagedep_hash);
1086 	sema_init(&pagedep_in_progress, "pagedep", 0, 0);
1087 	inodedep_hashtbl = hashinit(desiredvnodes, M_INODEDEP, &inodedep_hash);
1088 	sema_init(&inodedep_in_progress, "inodedep", 0, 0);
1089 	newblk_hashtbl = hashinit(64, M_NEWBLK, &newblk_hash);
1090 	sema_init(&newblk_in_progress, "newblk", 0, 0);
1091 }
1092 
1093 /*
1094  * Called at mount time to notify the dependency code that a
1095  * filesystem wishes to use it.
1096  */
1097 int
1098 softdep_mount(devvp, mp, fs)
1099 	struct vnode *devvp;
1100 	struct mount *mp;
1101 	struct fs *fs;
1102 {
1103 	struct csum cstotal;
1104 	struct cg *cgp;
1105 	struct buf *bp;
1106 	int error, cyl;
1107 
1108 	mp->mnt_flag &= ~MNT_ASYNC;
1109 	mp->mnt_flag |= MNT_SOFTDEP;
1110 	/*
1111 	 * When doing soft updates, the counters in the
1112 	 * superblock may have gotten out of sync, so we have
1113 	 * to scan the cylinder groups and recalculate them.
1114 	 */
1115 	if (fs->fs_clean != 0)
1116 		return (0);
1117 	bzero(&cstotal, sizeof cstotal);
1118 	for (cyl = 0; cyl < fs->fs_ncg; cyl++) {
1119 		if ((error = bread(devvp, fsbtodb(fs, cgtod(fs, cyl)),
1120 		    fs->fs_cgsize, &bp)) != 0) {
1121 			brelse(bp);
1122 			return (error);
1123 		}
1124 		cgp = (struct cg *)bp->b_data;
1125 		cstotal.cs_nffree += cgp->cg_cs.cs_nffree;
1126 		cstotal.cs_nbfree += cgp->cg_cs.cs_nbfree;
1127 		cstotal.cs_nifree += cgp->cg_cs.cs_nifree;
1128 		cstotal.cs_ndir += cgp->cg_cs.cs_ndir;
1129 		fs->fs_cs(fs, cyl) = cgp->cg_cs;
1130 		brelse(bp);
1131 	}
1132 #ifdef DEBUG
1133 	if (bcmp(&cstotal, &fs->fs_cstotal, sizeof cstotal))
1134 		printf("ffs_mountfs: superblock updated for soft updates\n");
1135 #endif
1136 	bcopy(&cstotal, &fs->fs_cstotal, sizeof cstotal);
1137 	return (0);
1138 }
1139 
1140 /*
1141  * Protecting the freemaps (or bitmaps).
1142  *
1143  * To eliminate the need to execute fsck before mounting a file system
1144  * after a power failure, one must (conservatively) guarantee that the
1145  * on-disk copy of the bitmaps never indicate that a live inode or block is
1146  * free.  So, when a block or inode is allocated, the bitmap should be
1147  * updated (on disk) before any new pointers.  When a block or inode is
1148  * freed, the bitmap should not be updated until all pointers have been
1149  * reset.  The latter dependency is handled by the delayed de-allocation
1150  * approach described below for block and inode de-allocation.  The former
1151  * dependency is handled by calling the following procedure when a block or
1152  * inode is allocated. When an inode is allocated an "inodedep" is created
1153  * with its DEPCOMPLETE flag cleared until its bitmap is written to disk.
1154  * Each "inodedep" is also inserted into the hash indexing structure so
1155  * that any additional link additions can be made dependent on the inode
1156  * allocation.
1157  *
1158  * The ufs file system maintains a number of free block counts (e.g., per
1159  * cylinder group, per cylinder and per <cylinder, rotational position> pair)
1160  * in addition to the bitmaps.  These counts are used to improve efficiency
1161  * during allocation and therefore must be consistent with the bitmaps.
1162  * There is no convenient way to guarantee post-crash consistency of these
1163  * counts with simple update ordering, for two main reasons: (1) The counts
1164  * and bitmaps for a single cylinder group block are not in the same disk
1165  * sector.  If a disk write is interrupted (e.g., by power failure), one may
1166  * be written and the other not.  (2) Some of the counts are located in the
1167  * superblock rather than the cylinder group block. So, we focus our soft
1168  * updates implementation on protecting the bitmaps. When mounting a
1169  * filesystem, we recompute the auxiliary counts from the bitmaps.
1170  */
1171 
1172 /*
1173  * Called just after updating the cylinder group block to allocate an inode.
1174  */
1175 void
1176 softdep_setup_inomapdep(bp, ip, newinum)
1177 	struct buf *bp;		/* buffer for cylgroup block with inode map */
1178 	struct inode *ip;	/* inode related to allocation */
1179 	ino_t newinum;		/* new inode number being allocated */
1180 {
1181 	struct inodedep *inodedep;
1182 	struct bmsafemap *bmsafemap;
1183 
1184 	/*
1185 	 * Create a dependency for the newly allocated inode.
1186 	 * Panic if it already exists as something is seriously wrong.
1187 	 * Otherwise add it to the dependency list for the buffer holding
1188 	 * the cylinder group map from which it was allocated.
1189 	 */
1190 	ACQUIRE_LOCK(&lk);
1191 	if ((inodedep_lookup(ip->i_fs, newinum, DEPALLOC|NODELAY, &inodedep))) {
1192 		FREE_LOCK(&lk);
1193 		panic("softdep_setup_inomapdep: found inode");
1194 	}
1195 	inodedep->id_buf = bp;
1196 	inodedep->id_state &= ~DEPCOMPLETE;
1197 	bmsafemap = bmsafemap_lookup(bp);
1198 	LIST_INSERT_HEAD(&bmsafemap->sm_inodedephd, inodedep, id_deps);
1199 	FREE_LOCK(&lk);
1200 }
1201 
1202 /*
1203  * Called just after updating the cylinder group block to
1204  * allocate block or fragment.
1205  */
1206 void
1207 softdep_setup_blkmapdep(bp, fs, newblkno)
1208 	struct buf *bp;		/* buffer for cylgroup block with block map */
1209 	struct fs *fs;		/* filesystem doing allocation */
1210 	ufs_daddr_t newblkno;	/* number of newly allocated block */
1211 {
1212 	struct newblk *newblk;
1213 	struct bmsafemap *bmsafemap;
1214 
1215 	/*
1216 	 * Create a dependency for the newly allocated block.
1217 	 * Add it to the dependency list for the buffer holding
1218 	 * the cylinder group map from which it was allocated.
1219 	 */
1220 	if (newblk_lookup(fs, newblkno, DEPALLOC, &newblk) != 0)
1221 		panic("softdep_setup_blkmapdep: found block");
1222 	ACQUIRE_LOCK(&lk);
1223 	newblk->nb_bmsafemap = bmsafemap = bmsafemap_lookup(bp);
1224 	LIST_INSERT_HEAD(&bmsafemap->sm_newblkhd, newblk, nb_deps);
1225 	FREE_LOCK(&lk);
1226 }
1227 
1228 /*
1229  * Find the bmsafemap associated with a cylinder group buffer.
1230  * If none exists, create one. The buffer must be locked when
1231  * this routine is called and this routine must be called with
1232  * splbio interrupts blocked.
1233  */
1234 static struct bmsafemap *
1235 bmsafemap_lookup(bp)
1236 	struct buf *bp;
1237 {
1238 	struct bmsafemap *bmsafemap;
1239 	struct worklist *wk;
1240 
1241 #ifdef DEBUG
1242 	if (lk.lkt_held == NOHOLDER)
1243 		panic("bmsafemap_lookup: lock not held");
1244 #endif
1245 	LIST_FOREACH(wk, &bp->b_dep, wk_list)
1246 		if (wk->wk_type == D_BMSAFEMAP)
1247 			return (WK_BMSAFEMAP(wk));
1248 	FREE_LOCK(&lk);
1249 	MALLOC(bmsafemap, struct bmsafemap *, sizeof(struct bmsafemap),
1250 		M_BMSAFEMAP, M_SOFTDEP_FLAGS);
1251 	bmsafemap->sm_list.wk_type = D_BMSAFEMAP;
1252 	bmsafemap->sm_list.wk_state = 0;
1253 	bmsafemap->sm_buf = bp;
1254 	LIST_INIT(&bmsafemap->sm_allocdirecthd);
1255 	LIST_INIT(&bmsafemap->sm_allocindirhd);
1256 	LIST_INIT(&bmsafemap->sm_inodedephd);
1257 	LIST_INIT(&bmsafemap->sm_newblkhd);
1258 	ACQUIRE_LOCK(&lk);
1259 	WORKLIST_INSERT(&bp->b_dep, &bmsafemap->sm_list);
1260 	return (bmsafemap);
1261 }
1262 
1263 /*
1264  * Direct block allocation dependencies.
1265  *
1266  * When a new block is allocated, the corresponding disk locations must be
1267  * initialized (with zeros or new data) before the on-disk inode points to
1268  * them.  Also, the freemap from which the block was allocated must be
1269  * updated (on disk) before the inode's pointer. These two dependencies are
1270  * independent of each other and are needed for all file blocks and indirect
1271  * blocks that are pointed to directly by the inode.  Just before the
1272  * "in-core" version of the inode is updated with a newly allocated block
1273  * number, a procedure (below) is called to setup allocation dependency
1274  * structures.  These structures are removed when the corresponding
1275  * dependencies are satisfied or when the block allocation becomes obsolete
1276  * (i.e., the file is deleted, the block is de-allocated, or the block is a
1277  * fragment that gets upgraded).  All of these cases are handled in
1278  * procedures described later.
1279  *
1280  * When a file extension causes a fragment to be upgraded, either to a larger
1281  * fragment or to a full block, the on-disk location may change (if the
1282  * previous fragment could not simply be extended). In this case, the old
1283  * fragment must be de-allocated, but not until after the inode's pointer has
1284  * been updated. In most cases, this is handled by later procedures, which
1285  * will construct a "freefrag" structure to be added to the workitem queue
1286  * when the inode update is complete (or obsolete).  The main exception to
1287  * this is when an allocation occurs while a pending allocation dependency
1288  * (for the same block pointer) remains.  This case is handled in the main
1289  * allocation dependency setup procedure by immediately freeing the
1290  * unreferenced fragments.
1291  */
1292 void
1293 softdep_setup_allocdirect(ip, lbn, newblkno, oldblkno, newsize, oldsize, bp)
1294 	struct inode *ip;	/* inode to which block is being added */
1295 	ufs_lbn_t lbn;		/* block pointer within inode */
1296 	ufs_daddr_t newblkno;	/* disk block number being added */
1297 	ufs_daddr_t oldblkno;	/* previous block number, 0 unless frag */
1298 	long newsize;		/* size of new block */
1299 	long oldsize;		/* size of new block */
1300 	struct buf *bp;		/* bp for allocated block */
1301 {
1302 	struct allocdirect *adp, *oldadp;
1303 	struct allocdirectlst *adphead;
1304 	struct bmsafemap *bmsafemap;
1305 	struct inodedep *inodedep;
1306 	struct pagedep *pagedep;
1307 	struct newblk *newblk;
1308 
1309 	MALLOC(adp, struct allocdirect *, sizeof(struct allocdirect),
1310 		M_ALLOCDIRECT, M_SOFTDEP_FLAGS);
1311 	bzero(adp, sizeof(struct allocdirect));
1312 	adp->ad_list.wk_type = D_ALLOCDIRECT;
1313 	adp->ad_lbn = lbn;
1314 	adp->ad_newblkno = newblkno;
1315 	adp->ad_oldblkno = oldblkno;
1316 	adp->ad_newsize = newsize;
1317 	adp->ad_oldsize = oldsize;
1318 	adp->ad_state = ATTACHED;
1319 	if (newblkno == oldblkno)
1320 		adp->ad_freefrag = NULL;
1321 	else
1322 		adp->ad_freefrag = newfreefrag(ip, oldblkno, oldsize);
1323 
1324 	if (newblk_lookup(ip->i_fs, newblkno, 0, &newblk) == 0)
1325 		panic("softdep_setup_allocdirect: lost block");
1326 
1327 	ACQUIRE_LOCK(&lk);
1328 	inodedep_lookup(ip->i_fs, ip->i_number, DEPALLOC | NODELAY, &inodedep);
1329 	adp->ad_inodedep = inodedep;
1330 
1331 	if (newblk->nb_state == DEPCOMPLETE) {
1332 		adp->ad_state |= DEPCOMPLETE;
1333 		adp->ad_buf = NULL;
1334 	} else {
1335 		bmsafemap = newblk->nb_bmsafemap;
1336 		adp->ad_buf = bmsafemap->sm_buf;
1337 		LIST_REMOVE(newblk, nb_deps);
1338 		LIST_INSERT_HEAD(&bmsafemap->sm_allocdirecthd, adp, ad_deps);
1339 	}
1340 	LIST_REMOVE(newblk, nb_hash);
1341 	FREE(newblk, M_NEWBLK);
1342 
1343 	WORKLIST_INSERT(&bp->b_dep, &adp->ad_list);
1344 	if (lbn >= NDADDR) {
1345 		/* allocating an indirect block */
1346 		if (oldblkno != 0) {
1347 			FREE_LOCK(&lk);
1348 			panic("softdep_setup_allocdirect: non-zero indir");
1349 		}
1350 	} else {
1351 		/*
1352 		 * Allocating a direct block.
1353 		 *
1354 		 * If we are allocating a directory block, then we must
1355 		 * allocate an associated pagedep to track additions and
1356 		 * deletions.
1357 		 */
1358 		if ((ip->i_mode & IFMT) == IFDIR &&
1359 		    pagedep_lookup(ip, lbn, DEPALLOC, &pagedep) == 0)
1360 			WORKLIST_INSERT(&bp->b_dep, &pagedep->pd_list);
1361 	}
1362 	/*
1363 	 * The list of allocdirects must be kept in sorted and ascending
1364 	 * order so that the rollback routines can quickly determine the
1365 	 * first uncommitted block (the size of the file stored on disk
1366 	 * ends at the end of the lowest committed fragment, or if there
1367 	 * are no fragments, at the end of the highest committed block).
1368 	 * Since files generally grow, the typical case is that the new
1369 	 * block is to be added at the end of the list. We speed this
1370 	 * special case by checking against the last allocdirect in the
1371 	 * list before laboriously traversing the list looking for the
1372 	 * insertion point.
1373 	 */
1374 	adphead = &inodedep->id_newinoupdt;
1375 	oldadp = TAILQ_LAST(adphead, allocdirectlst);
1376 	if (oldadp == NULL || oldadp->ad_lbn <= lbn) {
1377 		/* insert at end of list */
1378 		TAILQ_INSERT_TAIL(adphead, adp, ad_next);
1379 		if (oldadp != NULL && oldadp->ad_lbn == lbn)
1380 			allocdirect_merge(adphead, adp, oldadp);
1381 		FREE_LOCK(&lk);
1382 		return;
1383 	}
1384 	TAILQ_FOREACH(oldadp, adphead, ad_next) {
1385 		if (oldadp->ad_lbn >= lbn)
1386 			break;
1387 	}
1388 	if (oldadp == NULL) {
1389 		FREE_LOCK(&lk);
1390 		panic("softdep_setup_allocdirect: lost entry");
1391 	}
1392 	/* insert in middle of list */
1393 	TAILQ_INSERT_BEFORE(oldadp, adp, ad_next);
1394 	if (oldadp->ad_lbn == lbn)
1395 		allocdirect_merge(adphead, adp, oldadp);
1396 	FREE_LOCK(&lk);
1397 }
1398 
1399 /*
1400  * Replace an old allocdirect dependency with a newer one.
1401  * This routine must be called with splbio interrupts blocked.
1402  */
1403 static void
1404 allocdirect_merge(adphead, newadp, oldadp)
1405 	struct allocdirectlst *adphead;	/* head of list holding allocdirects */
1406 	struct allocdirect *newadp;	/* allocdirect being added */
1407 	struct allocdirect *oldadp;	/* existing allocdirect being checked */
1408 {
1409 	struct freefrag *freefrag;
1410 
1411 #ifdef DEBUG
1412 	if (lk.lkt_held == NOHOLDER)
1413 		panic("allocdirect_merge: lock not held");
1414 #endif
1415 	if (newadp->ad_oldblkno != oldadp->ad_newblkno ||
1416 	    newadp->ad_oldsize != oldadp->ad_newsize ||
1417 	    newadp->ad_lbn >= NDADDR) {
1418 		FREE_LOCK(&lk);
1419 		panic("allocdirect_check: old %d != new %d || lbn %ld >= %d",
1420 		    newadp->ad_oldblkno, oldadp->ad_newblkno, newadp->ad_lbn,
1421 		    NDADDR);
1422 	}
1423 	newadp->ad_oldblkno = oldadp->ad_oldblkno;
1424 	newadp->ad_oldsize = oldadp->ad_oldsize;
1425 	/*
1426 	 * If the old dependency had a fragment to free or had never
1427 	 * previously had a block allocated, then the new dependency
1428 	 * can immediately post its freefrag and adopt the old freefrag.
1429 	 * This action is done by swapping the freefrag dependencies.
1430 	 * The new dependency gains the old one's freefrag, and the
1431 	 * old one gets the new one and then immediately puts it on
1432 	 * the worklist when it is freed by free_allocdirect. It is
1433 	 * not possible to do this swap when the old dependency had a
1434 	 * non-zero size but no previous fragment to free. This condition
1435 	 * arises when the new block is an extension of the old block.
1436 	 * Here, the first part of the fragment allocated to the new
1437 	 * dependency is part of the block currently claimed on disk by
1438 	 * the old dependency, so cannot legitimately be freed until the
1439 	 * conditions for the new dependency are fulfilled.
1440 	 */
1441 	if (oldadp->ad_freefrag != NULL || oldadp->ad_oldblkno == 0) {
1442 		freefrag = newadp->ad_freefrag;
1443 		newadp->ad_freefrag = oldadp->ad_freefrag;
1444 		oldadp->ad_freefrag = freefrag;
1445 	}
1446 	free_allocdirect(adphead, oldadp, 0);
1447 }
1448 
1449 /*
1450  * Allocate a new freefrag structure if needed.
1451  */
1452 static struct freefrag *
1453 newfreefrag(ip, blkno, size)
1454 	struct inode *ip;
1455 	ufs_daddr_t blkno;
1456 	long size;
1457 {
1458 	struct freefrag *freefrag;
1459 	struct fs *fs;
1460 
1461 	if (blkno == 0)
1462 		return (NULL);
1463 	fs = ip->i_fs;
1464 	if (fragnum(fs, blkno) + numfrags(fs, size) > fs->fs_frag)
1465 		panic("newfreefrag: frag size");
1466 	MALLOC(freefrag, struct freefrag *, sizeof(struct freefrag),
1467 		M_FREEFRAG, M_SOFTDEP_FLAGS);
1468 	freefrag->ff_list.wk_type = D_FREEFRAG;
1469 	freefrag->ff_state = ip->i_uid & ~ONWORKLIST;	/* XXX - used below */
1470 	freefrag->ff_inum = ip->i_number;
1471 	freefrag->ff_fs = fs;
1472 	freefrag->ff_devvp = ip->i_devvp;
1473 	freefrag->ff_blkno = blkno;
1474 	freefrag->ff_fragsize = size;
1475 	return (freefrag);
1476 }
1477 
1478 /*
1479  * This workitem de-allocates fragments that were replaced during
1480  * file block allocation.
1481  */
1482 static void
1483 handle_workitem_freefrag(freefrag)
1484 	struct freefrag *freefrag;
1485 {
1486 	struct inode tip;
1487 
1488 	tip.i_fs = freefrag->ff_fs;
1489 	tip.i_devvp = freefrag->ff_devvp;
1490 	tip.i_dev = freefrag->ff_devvp->v_rdev;
1491 	tip.i_number = freefrag->ff_inum;
1492 	tip.i_uid = freefrag->ff_state & ~ONWORKLIST;	/* XXX - set above */
1493 	ffs_blkfree(&tip, freefrag->ff_blkno, freefrag->ff_fragsize);
1494 	FREE(freefrag, M_FREEFRAG);
1495 }
1496 
1497 /*
1498  * Indirect block allocation dependencies.
1499  *
1500  * The same dependencies that exist for a direct block also exist when
1501  * a new block is allocated and pointed to by an entry in a block of
1502  * indirect pointers. The undo/redo states described above are also
1503  * used here. Because an indirect block contains many pointers that
1504  * may have dependencies, a second copy of the entire in-memory indirect
1505  * block is kept. The buffer cache copy is always completely up-to-date.
1506  * The second copy, which is used only as a source for disk writes,
1507  * contains only the safe pointers (i.e., those that have no remaining
1508  * update dependencies). The second copy is freed when all pointers
1509  * are safe. The cache is not allowed to replace indirect blocks with
1510  * pending update dependencies. If a buffer containing an indirect
1511  * block with dependencies is written, these routines will mark it
1512  * dirty again. It can only be successfully written once all the
1513  * dependencies are removed. The ffs_fsync routine in conjunction with
1514  * softdep_sync_metadata work together to get all the dependencies
1515  * removed so that a file can be successfully written to disk. Three
1516  * procedures are used when setting up indirect block pointer
1517  * dependencies. The division is necessary because of the organization
1518  * of the "balloc" routine and because of the distinction between file
1519  * pages and file metadata blocks.
1520  */
1521 
1522 /*
1523  * Allocate a new allocindir structure.
1524  */
1525 static struct allocindir *
1526 newallocindir(ip, ptrno, newblkno, oldblkno)
1527 	struct inode *ip;	/* inode for file being extended */
1528 	int ptrno;		/* offset of pointer in indirect block */
1529 	ufs_daddr_t newblkno;	/* disk block number being added */
1530 	ufs_daddr_t oldblkno;	/* previous block number, 0 if none */
1531 {
1532 	struct allocindir *aip;
1533 
1534 	MALLOC(aip, struct allocindir *, sizeof(struct allocindir),
1535 		M_ALLOCINDIR, M_SOFTDEP_FLAGS);
1536 	bzero(aip, sizeof(struct allocindir));
1537 	aip->ai_list.wk_type = D_ALLOCINDIR;
1538 	aip->ai_state = ATTACHED;
1539 	aip->ai_offset = ptrno;
1540 	aip->ai_newblkno = newblkno;
1541 	aip->ai_oldblkno = oldblkno;
1542 	aip->ai_freefrag = newfreefrag(ip, oldblkno, ip->i_fs->fs_bsize);
1543 	return (aip);
1544 }
1545 
1546 /*
1547  * Called just before setting an indirect block pointer
1548  * to a newly allocated file page.
1549  */
1550 void
1551 softdep_setup_allocindir_page(ip, lbn, bp, ptrno, newblkno, oldblkno, nbp)
1552 	struct inode *ip;	/* inode for file being extended */
1553 	ufs_lbn_t lbn;		/* allocated block number within file */
1554 	struct buf *bp;		/* buffer with indirect blk referencing page */
1555 	int ptrno;		/* offset of pointer in indirect block */
1556 	ufs_daddr_t newblkno;	/* disk block number being added */
1557 	ufs_daddr_t oldblkno;	/* previous block number, 0 if none */
1558 	struct buf *nbp;	/* buffer holding allocated page */
1559 {
1560 	struct allocindir *aip;
1561 	struct pagedep *pagedep;
1562 
1563 	aip = newallocindir(ip, ptrno, newblkno, oldblkno);
1564 	ACQUIRE_LOCK(&lk);
1565 	/*
1566 	 * If we are allocating a directory page, then we must
1567 	 * allocate an associated pagedep to track additions and
1568 	 * deletions.
1569 	 */
1570 	if ((ip->i_mode & IFMT) == IFDIR &&
1571 	    pagedep_lookup(ip, lbn, DEPALLOC, &pagedep) == 0)
1572 		WORKLIST_INSERT(&nbp->b_dep, &pagedep->pd_list);
1573 	WORKLIST_INSERT(&nbp->b_dep, &aip->ai_list);
1574 	FREE_LOCK(&lk);
1575 	setup_allocindir_phase2(bp, ip, aip);
1576 }
1577 
1578 /*
1579  * Called just before setting an indirect block pointer to a
1580  * newly allocated indirect block.
1581  */
1582 void
1583 softdep_setup_allocindir_meta(nbp, ip, bp, ptrno, newblkno)
1584 	struct buf *nbp;	/* newly allocated indirect block */
1585 	struct inode *ip;	/* inode for file being extended */
1586 	struct buf *bp;		/* indirect block referencing allocated block */
1587 	int ptrno;		/* offset of pointer in indirect block */
1588 	ufs_daddr_t newblkno;	/* disk block number being added */
1589 {
1590 	struct allocindir *aip;
1591 
1592 	aip = newallocindir(ip, ptrno, newblkno, 0);
1593 	ACQUIRE_LOCK(&lk);
1594 	WORKLIST_INSERT(&nbp->b_dep, &aip->ai_list);
1595 	FREE_LOCK(&lk);
1596 	setup_allocindir_phase2(bp, ip, aip);
1597 }
1598 
1599 /*
1600  * Called to finish the allocation of the "aip" allocated
1601  * by one of the two routines above.
1602  */
1603 static void
1604 setup_allocindir_phase2(bp, ip, aip)
1605 	struct buf *bp;		/* in-memory copy of the indirect block */
1606 	struct inode *ip;	/* inode for file being extended */
1607 	struct allocindir *aip;	/* allocindir allocated by the above routines */
1608 {
1609 	struct worklist *wk;
1610 	struct indirdep *indirdep, *newindirdep;
1611 	struct bmsafemap *bmsafemap;
1612 	struct allocindir *oldaip;
1613 	struct freefrag *freefrag;
1614 	struct newblk *newblk;
1615 
1616 	if (bp->b_lblkno >= 0)
1617 		panic("setup_allocindir_phase2: not indir blk");
1618 	for (indirdep = NULL, newindirdep = NULL; ; ) {
1619 		ACQUIRE_LOCK(&lk);
1620 		LIST_FOREACH(wk, &bp->b_dep, wk_list) {
1621 			if (wk->wk_type != D_INDIRDEP)
1622 				continue;
1623 			indirdep = WK_INDIRDEP(wk);
1624 			break;
1625 		}
1626 		if (indirdep == NULL && newindirdep) {
1627 			indirdep = newindirdep;
1628 			WORKLIST_INSERT(&bp->b_dep, &indirdep->ir_list);
1629 			newindirdep = NULL;
1630 		}
1631 		FREE_LOCK(&lk);
1632 		if (indirdep) {
1633 			if (newblk_lookup(ip->i_fs, aip->ai_newblkno, 0,
1634 			    &newblk) == 0)
1635 				panic("setup_allocindir: lost block");
1636 			ACQUIRE_LOCK(&lk);
1637 			if (newblk->nb_state == DEPCOMPLETE) {
1638 				aip->ai_state |= DEPCOMPLETE;
1639 				aip->ai_buf = NULL;
1640 			} else {
1641 				bmsafemap = newblk->nb_bmsafemap;
1642 				aip->ai_buf = bmsafemap->sm_buf;
1643 				LIST_REMOVE(newblk, nb_deps);
1644 				LIST_INSERT_HEAD(&bmsafemap->sm_allocindirhd,
1645 				    aip, ai_deps);
1646 			}
1647 			LIST_REMOVE(newblk, nb_hash);
1648 			FREE(newblk, M_NEWBLK);
1649 			aip->ai_indirdep = indirdep;
1650 			/*
1651 			 * Check to see if there is an existing dependency
1652 			 * for this block. If there is, merge the old
1653 			 * dependency into the new one.
1654 			 */
1655 			if (aip->ai_oldblkno == 0)
1656 				oldaip = NULL;
1657 			else
1658 
1659 				LIST_FOREACH(oldaip, &indirdep->ir_deplisthd, ai_next)
1660 					if (oldaip->ai_offset == aip->ai_offset)
1661 						break;
1662 			if (oldaip != NULL) {
1663 				if (oldaip->ai_newblkno != aip->ai_oldblkno) {
1664 					FREE_LOCK(&lk);
1665 					panic("setup_allocindir_phase2: blkno");
1666 				}
1667 				aip->ai_oldblkno = oldaip->ai_oldblkno;
1668 				freefrag = oldaip->ai_freefrag;
1669 				oldaip->ai_freefrag = aip->ai_freefrag;
1670 				aip->ai_freefrag = freefrag;
1671 				free_allocindir(oldaip, NULL);
1672 			}
1673 			LIST_INSERT_HEAD(&indirdep->ir_deplisthd, aip, ai_next);
1674 			((ufs_daddr_t *)indirdep->ir_savebp->b_data)
1675 			    [aip->ai_offset] = aip->ai_oldblkno;
1676 			FREE_LOCK(&lk);
1677 		}
1678 		if (newindirdep) {
1679 			if (indirdep->ir_savebp != NULL)
1680 				brelse(newindirdep->ir_savebp);
1681 			WORKITEM_FREE((caddr_t)newindirdep, D_INDIRDEP);
1682 		}
1683 		if (indirdep)
1684 			break;
1685 		MALLOC(newindirdep, struct indirdep *, sizeof(struct indirdep),
1686 			M_INDIRDEP, M_SOFTDEP_FLAGS);
1687 		newindirdep->ir_list.wk_type = D_INDIRDEP;
1688 		newindirdep->ir_state = ATTACHED;
1689 		LIST_INIT(&newindirdep->ir_deplisthd);
1690 		LIST_INIT(&newindirdep->ir_donehd);
1691 		if (bp->b_blkno == bp->b_lblkno) {
1692 			VOP_BMAP(bp->b_vp, bp->b_lblkno, NULL, &bp->b_blkno,
1693 				NULL, NULL);
1694 		}
1695 		newindirdep->ir_savebp =
1696 		    getblk(ip->i_devvp, bp->b_blkno, bp->b_bcount, 0, 0);
1697 		BUF_KERNPROC(newindirdep->ir_savebp);
1698 		bcopy(bp->b_data, newindirdep->ir_savebp->b_data, bp->b_bcount);
1699 	}
1700 }
1701 
1702 /*
1703  * Block de-allocation dependencies.
1704  *
1705  * When blocks are de-allocated, the on-disk pointers must be nullified before
1706  * the blocks are made available for use by other files.  (The true
1707  * requirement is that old pointers must be nullified before new on-disk
1708  * pointers are set.  We chose this slightly more stringent requirement to
1709  * reduce complexity.) Our implementation handles this dependency by updating
1710  * the inode (or indirect block) appropriately but delaying the actual block
1711  * de-allocation (i.e., freemap and free space count manipulation) until
1712  * after the updated versions reach stable storage.  After the disk is
1713  * updated, the blocks can be safely de-allocated whenever it is convenient.
1714  * This implementation handles only the common case of reducing a file's
1715  * length to zero. Other cases are handled by the conventional synchronous
1716  * write approach.
1717  *
1718  * The ffs implementation with which we worked double-checks
1719  * the state of the block pointers and file size as it reduces
1720  * a file's length.  Some of this code is replicated here in our
1721  * soft updates implementation.  The freeblks->fb_chkcnt field is
1722  * used to transfer a part of this information to the procedure
1723  * that eventually de-allocates the blocks.
1724  *
1725  * This routine should be called from the routine that shortens
1726  * a file's length, before the inode's size or block pointers
1727  * are modified. It will save the block pointer information for
1728  * later release and zero the inode so that the calling routine
1729  * can release it.
1730  */
1731 void
1732 softdep_setup_freeblocks(ip, length)
1733 	struct inode *ip;	/* The inode whose length is to be reduced */
1734 	off_t length;		/* The new length for the file */
1735 {
1736 	struct freeblks *freeblks;
1737 	struct inodedep *inodedep;
1738 	struct allocdirect *adp;
1739 	struct vnode *vp;
1740 	struct buf *bp;
1741 	struct fs *fs;
1742 	int i, error, delay;
1743 
1744 	fs = ip->i_fs;
1745 	if (length != 0)
1746 		panic("softde_setup_freeblocks: non-zero length");
1747 	MALLOC(freeblks, struct freeblks *, sizeof(struct freeblks),
1748 		M_FREEBLKS, M_SOFTDEP_FLAGS);
1749 	bzero(freeblks, sizeof(struct freeblks));
1750 	freeblks->fb_list.wk_type = D_FREEBLKS;
1751 	freeblks->fb_uid = ip->i_uid;
1752 	freeblks->fb_previousinum = ip->i_number;
1753 	freeblks->fb_devvp = ip->i_devvp;
1754 	freeblks->fb_fs = fs;
1755 	freeblks->fb_oldsize = ip->i_size;
1756 	freeblks->fb_newsize = length;
1757 	freeblks->fb_chkcnt = ip->i_blocks;
1758 	for (i = 0; i < NDADDR; i++) {
1759 		freeblks->fb_dblks[i] = ip->i_db[i];
1760 		ip->i_db[i] = 0;
1761 	}
1762 	for (i = 0; i < NIADDR; i++) {
1763 		freeblks->fb_iblks[i] = ip->i_ib[i];
1764 		ip->i_ib[i] = 0;
1765 	}
1766 	ip->i_blocks = 0;
1767 	ip->i_size = 0;
1768 	/*
1769 	 * Push the zero'ed inode to to its disk buffer so that we are free
1770 	 * to delete its dependencies below. Once the dependencies are gone
1771 	 * the buffer can be safely released.
1772 	 */
1773 	if ((error = bread(ip->i_devvp,
1774 	    fsbtodb(fs, ino_to_fsba(fs, ip->i_number)),
1775 	    (int)fs->fs_bsize, &bp)) != 0)
1776 		softdep_error("softdep_setup_freeblocks", error);
1777 	*((struct dinode *)bp->b_data + ino_to_fsbo(fs, ip->i_number)) =
1778 	    ip->i_din;
1779 	/*
1780 	 * Find and eliminate any inode dependencies.
1781 	 */
1782 	ACQUIRE_LOCK(&lk);
1783 	(void) inodedep_lookup(fs, ip->i_number, DEPALLOC, &inodedep);
1784 	if ((inodedep->id_state & IOSTARTED) != 0) {
1785 		FREE_LOCK(&lk);
1786 		panic("softdep_setup_freeblocks: inode busy");
1787 	}
1788 	/*
1789 	 * Add the freeblks structure to the list of operations that
1790 	 * must await the zero'ed inode being written to disk. If we
1791 	 * still have a bitmap dependency (delay == 0), then the inode
1792 	 * has never been written to disk, so we can process the
1793 	 * freeblks below once we have deleted the dependencies.
1794 	 */
1795 	delay = (inodedep->id_state & DEPCOMPLETE);
1796 	if (delay)
1797 		WORKLIST_INSERT(&inodedep->id_bufwait, &freeblks->fb_list);
1798 	/*
1799 	 * Because the file length has been truncated to zero, any
1800 	 * pending block allocation dependency structures associated
1801 	 * with this inode are obsolete and can simply be de-allocated.
1802 	 * We must first merge the two dependency lists to get rid of
1803 	 * any duplicate freefrag structures, then purge the merged list.
1804 	 */
1805 	merge_inode_lists(inodedep);
1806 	while ((adp = TAILQ_FIRST(&inodedep->id_inoupdt)) != 0)
1807 		free_allocdirect(&inodedep->id_inoupdt, adp, 1);
1808 	FREE_LOCK(&lk);
1809 	bdwrite(bp);
1810 	/*
1811 	 * We must wait for any I/O in progress to finish so that
1812 	 * all potential buffers on the dirty list will be visible.
1813 	 * Once they are all there, walk the list and get rid of
1814 	 * any dependencies.
1815 	 */
1816 	vp = ITOV(ip);
1817 	ACQUIRE_LOCK(&lk);
1818 	drain_output(vp, 1);
1819 	while (getdirtybuf(&TAILQ_FIRST(&vp->v_dirtyblkhd), MNT_WAIT)) {
1820 		bp = TAILQ_FIRST(&vp->v_dirtyblkhd);
1821 		(void) inodedep_lookup(fs, ip->i_number, 0, &inodedep);
1822 		deallocate_dependencies(bp, inodedep);
1823 		bp->b_flags |= B_INVAL | B_NOCACHE;
1824 		FREE_LOCK(&lk);
1825 		brelse(bp);
1826 		ACQUIRE_LOCK(&lk);
1827 	}
1828 	if (inodedep_lookup(fs, ip->i_number, 0, &inodedep) != 0)
1829 		(void)free_inodedep(inodedep);
1830 	FREE_LOCK(&lk);
1831 	/*
1832 	 * If the inode has never been written to disk (delay == 0),
1833 	 * then we can process the freeblks now that we have deleted
1834 	 * the dependencies.
1835 	 */
1836 	if (!delay)
1837 		handle_workitem_freeblocks(freeblks);
1838 }
1839 
1840 /*
1841  * Reclaim any dependency structures from a buffer that is about to
1842  * be reallocated to a new vnode. The buffer must be locked, thus,
1843  * no I/O completion operations can occur while we are manipulating
1844  * its associated dependencies. The mutex is held so that other I/O's
1845  * associated with related dependencies do not occur.
1846  */
1847 static void
1848 deallocate_dependencies(bp, inodedep)
1849 	struct buf *bp;
1850 	struct inodedep *inodedep;
1851 {
1852 	struct worklist *wk;
1853 	struct indirdep *indirdep;
1854 	struct allocindir *aip;
1855 	struct pagedep *pagedep;
1856 	struct dirrem *dirrem;
1857 	struct diradd *dap;
1858 	int i;
1859 
1860 	while ((wk = LIST_FIRST(&bp->b_dep)) != NULL) {
1861 		switch (wk->wk_type) {
1862 
1863 		case D_INDIRDEP:
1864 			indirdep = WK_INDIRDEP(wk);
1865 			/*
1866 			 * None of the indirect pointers will ever be visible,
1867 			 * so they can simply be tossed. GOINGAWAY ensures
1868 			 * that allocated pointers will be saved in the buffer
1869 			 * cache until they are freed. Note that they will
1870 			 * only be able to be found by their physical address
1871 			 * since the inode mapping the logical address will
1872 			 * be gone. The save buffer used for the safe copy
1873 			 * was allocated in setup_allocindir_phase2 using
1874 			 * the physical address so it could be used for this
1875 			 * purpose. Hence we swap the safe copy with the real
1876 			 * copy, allowing the safe copy to be freed and holding
1877 			 * on to the real copy for later use in indir_trunc.
1878 			 */
1879 			if (indirdep->ir_state & GOINGAWAY) {
1880 				FREE_LOCK(&lk);
1881 				panic("deallocate_dependencies: already gone");
1882 			}
1883 			indirdep->ir_state |= GOINGAWAY;
1884 			while ((aip = LIST_FIRST(&indirdep->ir_deplisthd)) != 0)
1885 				free_allocindir(aip, inodedep);
1886 			if (bp->b_lblkno >= 0 ||
1887 			    bp->b_blkno != indirdep->ir_savebp->b_lblkno) {
1888 				FREE_LOCK(&lk);
1889 				panic("deallocate_dependencies: not indir");
1890 			}
1891 			bcopy(bp->b_data, indirdep->ir_savebp->b_data,
1892 			    bp->b_bcount);
1893 			WORKLIST_REMOVE(wk);
1894 			WORKLIST_INSERT(&indirdep->ir_savebp->b_dep, wk);
1895 			continue;
1896 
1897 		case D_PAGEDEP:
1898 			pagedep = WK_PAGEDEP(wk);
1899 			/*
1900 			 * None of the directory additions will ever be
1901 			 * visible, so they can simply be tossed.
1902 			 */
1903 			for (i = 0; i < DAHASHSZ; i++)
1904 				while ((dap =
1905 				    LIST_FIRST(&pagedep->pd_diraddhd[i])))
1906 					free_diradd(dap);
1907 			while ((dap = LIST_FIRST(&pagedep->pd_pendinghd)) != 0)
1908 				free_diradd(dap);
1909 			/*
1910 			 * Copy any directory remove dependencies to the list
1911 			 * to be processed after the zero'ed inode is written.
1912 			 * If the inode has already been written, then they
1913 			 * can be dumped directly onto the work list.
1914 			 */
1915 			LIST_FOREACH(dirrem, &pagedep->pd_dirremhd, dm_next) {
1916 				LIST_REMOVE(dirrem, dm_next);
1917 				dirrem->dm_dirinum = pagedep->pd_ino;
1918 				if (inodedep == NULL ||
1919 				    (inodedep->id_state & ALLCOMPLETE) ==
1920 				     ALLCOMPLETE)
1921 					add_to_worklist(&dirrem->dm_list);
1922 				else
1923 					WORKLIST_INSERT(&inodedep->id_bufwait,
1924 					    &dirrem->dm_list);
1925 			}
1926 			WORKLIST_REMOVE(&pagedep->pd_list);
1927 			LIST_REMOVE(pagedep, pd_hash);
1928 			WORKITEM_FREE(pagedep, D_PAGEDEP);
1929 			continue;
1930 
1931 		case D_ALLOCINDIR:
1932 			free_allocindir(WK_ALLOCINDIR(wk), inodedep);
1933 			continue;
1934 
1935 		case D_ALLOCDIRECT:
1936 		case D_INODEDEP:
1937 			FREE_LOCK(&lk);
1938 			panic("deallocate_dependencies: Unexpected type %s",
1939 			    TYPENAME(wk->wk_type));
1940 			/* NOTREACHED */
1941 
1942 		default:
1943 			FREE_LOCK(&lk);
1944 			panic("deallocate_dependencies: Unknown type %s",
1945 			    TYPENAME(wk->wk_type));
1946 			/* NOTREACHED */
1947 		}
1948 	}
1949 }
1950 
1951 /*
1952  * Free an allocdirect. Generate a new freefrag work request if appropriate.
1953  * This routine must be called with splbio interrupts blocked.
1954  */
1955 static void
1956 free_allocdirect(adphead, adp, delay)
1957 	struct allocdirectlst *adphead;
1958 	struct allocdirect *adp;
1959 	int delay;
1960 {
1961 
1962 #ifdef DEBUG
1963 	if (lk.lkt_held == NOHOLDER)
1964 		panic("free_allocdirect: lock not held");
1965 #endif
1966 	if ((adp->ad_state & DEPCOMPLETE) == 0)
1967 		LIST_REMOVE(adp, ad_deps);
1968 	TAILQ_REMOVE(adphead, adp, ad_next);
1969 	if ((adp->ad_state & COMPLETE) == 0)
1970 		WORKLIST_REMOVE(&adp->ad_list);
1971 	if (adp->ad_freefrag != NULL) {
1972 		if (delay)
1973 			WORKLIST_INSERT(&adp->ad_inodedep->id_bufwait,
1974 			    &adp->ad_freefrag->ff_list);
1975 		else
1976 			add_to_worklist(&adp->ad_freefrag->ff_list);
1977 	}
1978 	WORKITEM_FREE(adp, D_ALLOCDIRECT);
1979 }
1980 
1981 /*
1982  * Prepare an inode to be freed. The actual free operation is not
1983  * done until the zero'ed inode has been written to disk.
1984  */
1985 void
1986 softdep_freefile(pvp, ino, mode)
1987 		struct vnode *pvp;
1988 		ino_t ino;
1989 		int mode;
1990 {
1991 	struct inode *ip = VTOI(pvp);
1992 	struct inodedep *inodedep;
1993 	struct freefile *freefile;
1994 
1995 	/*
1996 	 * This sets up the inode de-allocation dependency.
1997 	 */
1998 	MALLOC(freefile, struct freefile *, sizeof(struct freefile),
1999 		M_FREEFILE, M_SOFTDEP_FLAGS);
2000 	freefile->fx_list.wk_type = D_FREEFILE;
2001 	freefile->fx_list.wk_state = 0;
2002 	freefile->fx_mode = mode;
2003 	freefile->fx_oldinum = ino;
2004 	freefile->fx_devvp = ip->i_devvp;
2005 	freefile->fx_fs = ip->i_fs;
2006 
2007 	/*
2008 	 * If the inodedep does not exist, then the zero'ed inode has
2009 	 * been written to disk. If the allocated inode has never been
2010 	 * written to disk, then the on-disk inode is zero'ed. In either
2011 	 * case we can free the file immediately.
2012 	 */
2013 	ACQUIRE_LOCK(&lk);
2014 	if (inodedep_lookup(ip->i_fs, ino, 0, &inodedep) == 0 ||
2015 	    check_inode_unwritten(inodedep)) {
2016 		FREE_LOCK(&lk);
2017 		handle_workitem_freefile(freefile);
2018 		return;
2019 	}
2020 	WORKLIST_INSERT(&inodedep->id_inowait, &freefile->fx_list);
2021 	FREE_LOCK(&lk);
2022 }
2023 
2024 /*
2025  * Check to see if an inode has never been written to disk. If
2026  * so free the inodedep and return success, otherwise return failure.
2027  * This routine must be called with splbio interrupts blocked.
2028  *
2029  * If we still have a bitmap dependency, then the inode has never
2030  * been written to disk. Drop the dependency as it is no longer
2031  * necessary since the inode is being deallocated. We set the
2032  * ALLCOMPLETE flags since the bitmap now properly shows that the
2033  * inode is not allocated. Even if the inode is actively being
2034  * written, it has been rolled back to its zero'ed state, so we
2035  * are ensured that a zero inode is what is on the disk. For short
2036  * lived files, this change will usually result in removing all the
2037  * dependencies from the inode so that it can be freed immediately.
2038  */
2039 static int
2040 check_inode_unwritten(inodedep)
2041 	struct inodedep *inodedep;
2042 {
2043 
2044 	if ((inodedep->id_state & DEPCOMPLETE) != 0 ||
2045 	    LIST_FIRST(&inodedep->id_pendinghd) != NULL ||
2046 	    LIST_FIRST(&inodedep->id_bufwait) != NULL ||
2047 	    LIST_FIRST(&inodedep->id_inowait) != NULL ||
2048 	    TAILQ_FIRST(&inodedep->id_inoupdt) != NULL ||
2049 	    TAILQ_FIRST(&inodedep->id_newinoupdt) != NULL ||
2050 	    inodedep->id_nlinkdelta != 0)
2051 		return (0);
2052 	inodedep->id_state |= ALLCOMPLETE;
2053 	LIST_REMOVE(inodedep, id_deps);
2054 	inodedep->id_buf = NULL;
2055 	if (inodedep->id_state & ONWORKLIST)
2056 		WORKLIST_REMOVE(&inodedep->id_list);
2057 	if (inodedep->id_savedino != NULL) {
2058 		FREE(inodedep->id_savedino, M_INODEDEP);
2059 		inodedep->id_savedino = NULL;
2060 	}
2061 	if (free_inodedep(inodedep) == 0) {
2062 		FREE_LOCK(&lk);
2063 		panic("check_inode_unwritten: busy inode");
2064 	}
2065 	return (1);
2066 }
2067 
2068 /*
2069  * Try to free an inodedep structure. Return 1 if it could be freed.
2070  */
2071 static int
2072 free_inodedep(inodedep)
2073 	struct inodedep *inodedep;
2074 {
2075 
2076 	if ((inodedep->id_state & ONWORKLIST) != 0 ||
2077 	    (inodedep->id_state & ALLCOMPLETE) != ALLCOMPLETE ||
2078 	    LIST_FIRST(&inodedep->id_pendinghd) != NULL ||
2079 	    LIST_FIRST(&inodedep->id_bufwait) != NULL ||
2080 	    LIST_FIRST(&inodedep->id_inowait) != NULL ||
2081 	    TAILQ_FIRST(&inodedep->id_inoupdt) != NULL ||
2082 	    TAILQ_FIRST(&inodedep->id_newinoupdt) != NULL ||
2083 	    inodedep->id_nlinkdelta != 0 || inodedep->id_savedino != NULL)
2084 		return (0);
2085 	LIST_REMOVE(inodedep, id_hash);
2086 	WORKITEM_FREE(inodedep, D_INODEDEP);
2087 	num_inodedep -= 1;
2088 	return (1);
2089 }
2090 
2091 /*
2092  * This workitem routine performs the block de-allocation.
2093  * The workitem is added to the pending list after the updated
2094  * inode block has been written to disk.  As mentioned above,
2095  * checks regarding the number of blocks de-allocated (compared
2096  * to the number of blocks allocated for the file) are also
2097  * performed in this function.
2098  */
2099 static void
2100 handle_workitem_freeblocks(freeblks)
2101 	struct freeblks *freeblks;
2102 {
2103 	struct inode tip;
2104 	ufs_daddr_t bn;
2105 	struct fs *fs;
2106 	int i, level, bsize;
2107 	long nblocks, blocksreleased = 0;
2108 	int error, allerror = 0;
2109 	ufs_lbn_t baselbns[NIADDR], tmpval;
2110 
2111 	tip.i_number = freeblks->fb_previousinum;
2112 	tip.i_devvp = freeblks->fb_devvp;
2113 	tip.i_dev = freeblks->fb_devvp->v_rdev;
2114 	tip.i_fs = freeblks->fb_fs;
2115 	tip.i_size = freeblks->fb_oldsize;
2116 	tip.i_uid = freeblks->fb_uid;
2117 	fs = freeblks->fb_fs;
2118 	tmpval = 1;
2119 	baselbns[0] = NDADDR;
2120 	for (i = 1; i < NIADDR; i++) {
2121 		tmpval *= NINDIR(fs);
2122 		baselbns[i] = baselbns[i - 1] + tmpval;
2123 	}
2124 	nblocks = btodb(fs->fs_bsize);
2125 	blocksreleased = 0;
2126 	/*
2127 	 * Indirect blocks first.
2128 	 */
2129 	for (level = (NIADDR - 1); level >= 0; level--) {
2130 		if ((bn = freeblks->fb_iblks[level]) == 0)
2131 			continue;
2132 		if ((error = indir_trunc(&tip, fsbtodb(fs, bn), level,
2133 		    baselbns[level], &blocksreleased)) == 0)
2134 			allerror = error;
2135 		ffs_blkfree(&tip, bn, fs->fs_bsize);
2136 		blocksreleased += nblocks;
2137 	}
2138 	/*
2139 	 * All direct blocks or frags.
2140 	 */
2141 	for (i = (NDADDR - 1); i >= 0; i--) {
2142 		if ((bn = freeblks->fb_dblks[i]) == 0)
2143 			continue;
2144 		bsize = blksize(fs, &tip, i);
2145 		ffs_blkfree(&tip, bn, bsize);
2146 		blocksreleased += btodb(bsize);
2147 	}
2148 
2149 #ifdef DIAGNOSTIC
2150 	if (freeblks->fb_chkcnt != blocksreleased)
2151 		printf("handle_workitem_freeblocks: block count\n");
2152 	if (allerror)
2153 		softdep_error("handle_workitem_freeblks", allerror);
2154 #endif /* DIAGNOSTIC */
2155 	WORKITEM_FREE(freeblks, D_FREEBLKS);
2156 }
2157 
2158 /*
2159  * Release blocks associated with the inode ip and stored in the indirect
2160  * block dbn. If level is greater than SINGLE, the block is an indirect block
2161  * and recursive calls to indirtrunc must be used to cleanse other indirect
2162  * blocks.
2163  */
2164 static int
2165 indir_trunc(ip, dbn, level, lbn, countp)
2166 	struct inode *ip;
2167 	ufs_daddr_t dbn;
2168 	int level;
2169 	ufs_lbn_t lbn;
2170 	long *countp;
2171 {
2172 	struct buf *bp;
2173 	ufs_daddr_t *bap;
2174 	ufs_daddr_t nb;
2175 	struct fs *fs;
2176 	struct worklist *wk;
2177 	struct indirdep *indirdep;
2178 	int i, lbnadd, nblocks;
2179 	int error, allerror = 0;
2180 
2181 	fs = ip->i_fs;
2182 	lbnadd = 1;
2183 	for (i = level; i > 0; i--)
2184 		lbnadd *= NINDIR(fs);
2185 	/*
2186 	 * Get buffer of block pointers to be freed. This routine is not
2187 	 * called until the zero'ed inode has been written, so it is safe
2188 	 * to free blocks as they are encountered. Because the inode has
2189 	 * been zero'ed, calls to bmap on these blocks will fail. So, we
2190 	 * have to use the on-disk address and the block device for the
2191 	 * filesystem to look them up. If the file was deleted before its
2192 	 * indirect blocks were all written to disk, the routine that set
2193 	 * us up (deallocate_dependencies) will have arranged to leave
2194 	 * a complete copy of the indirect block in memory for our use.
2195 	 * Otherwise we have to read the blocks in from the disk.
2196 	 */
2197 	ACQUIRE_LOCK(&lk);
2198 	if ((bp = incore(ip->i_devvp, dbn)) != NULL &&
2199 	    (wk = LIST_FIRST(&bp->b_dep)) != NULL) {
2200 		if (wk->wk_type != D_INDIRDEP ||
2201 		    (indirdep = WK_INDIRDEP(wk))->ir_savebp != bp ||
2202 		    (indirdep->ir_state & GOINGAWAY) == 0) {
2203 			FREE_LOCK(&lk);
2204 			panic("indir_trunc: lost indirdep");
2205 		}
2206 		WORKLIST_REMOVE(wk);
2207 		WORKITEM_FREE(indirdep, D_INDIRDEP);
2208 		if (LIST_FIRST(&bp->b_dep) != NULL) {
2209 			FREE_LOCK(&lk);
2210 			panic("indir_trunc: dangling dep");
2211 		}
2212 		FREE_LOCK(&lk);
2213 	} else {
2214 		FREE_LOCK(&lk);
2215 		error = bread(ip->i_devvp, dbn, (int)fs->fs_bsize, &bp);
2216 		if (error)
2217 			return (error);
2218 	}
2219 	/*
2220 	 * Recursively free indirect blocks.
2221 	 */
2222 	bap = (ufs_daddr_t *)bp->b_data;
2223 	nblocks = btodb(fs->fs_bsize);
2224 	for (i = NINDIR(fs) - 1; i >= 0; i--) {
2225 		if ((nb = bap[i]) == 0)
2226 			continue;
2227 		if (level != 0) {
2228 			if ((error = indir_trunc(ip, fsbtodb(fs, nb),
2229 			     level - 1, lbn + (i * lbnadd), countp)) != 0)
2230 				allerror = error;
2231 		}
2232 		ffs_blkfree(ip, nb, fs->fs_bsize);
2233 		*countp += nblocks;
2234 	}
2235 	bp->b_flags |= B_INVAL | B_NOCACHE;
2236 	brelse(bp);
2237 	return (allerror);
2238 }
2239 
2240 /*
2241  * Free an allocindir.
2242  * This routine must be called with splbio interrupts blocked.
2243  */
2244 static void
2245 free_allocindir(aip, inodedep)
2246 	struct allocindir *aip;
2247 	struct inodedep *inodedep;
2248 {
2249 	struct freefrag *freefrag;
2250 
2251 #ifdef DEBUG
2252 	if (lk.lkt_held == NOHOLDER)
2253 		panic("free_allocindir: lock not held");
2254 #endif
2255 	if ((aip->ai_state & DEPCOMPLETE) == 0)
2256 		LIST_REMOVE(aip, ai_deps);
2257 	if (aip->ai_state & ONWORKLIST)
2258 		WORKLIST_REMOVE(&aip->ai_list);
2259 	LIST_REMOVE(aip, ai_next);
2260 	if ((freefrag = aip->ai_freefrag) != NULL) {
2261 		if (inodedep == NULL)
2262 			add_to_worklist(&freefrag->ff_list);
2263 		else
2264 			WORKLIST_INSERT(&inodedep->id_bufwait,
2265 			    &freefrag->ff_list);
2266 	}
2267 	WORKITEM_FREE(aip, D_ALLOCINDIR);
2268 }
2269 
2270 /*
2271  * Directory entry addition dependencies.
2272  *
2273  * When adding a new directory entry, the inode (with its incremented link
2274  * count) must be written to disk before the directory entry's pointer to it.
2275  * Also, if the inode is newly allocated, the corresponding freemap must be
2276  * updated (on disk) before the directory entry's pointer. These requirements
2277  * are met via undo/redo on the directory entry's pointer, which consists
2278  * simply of the inode number.
2279  *
2280  * As directory entries are added and deleted, the free space within a
2281  * directory block can become fragmented.  The ufs file system will compact
2282  * a fragmented directory block to make space for a new entry. When this
2283  * occurs, the offsets of previously added entries change. Any "diradd"
2284  * dependency structures corresponding to these entries must be updated with
2285  * the new offsets.
2286  */
2287 
2288 /*
2289  * This routine is called after the in-memory inode's link
2290  * count has been incremented, but before the directory entry's
2291  * pointer to the inode has been set.
2292  */
2293 void
2294 softdep_setup_directory_add(bp, dp, diroffset, newinum, newdirbp)
2295 	struct buf *bp;		/* buffer containing directory block */
2296 	struct inode *dp;	/* inode for directory */
2297 	off_t diroffset;	/* offset of new entry in directory */
2298 	long newinum;		/* inode referenced by new directory entry */
2299 	struct buf *newdirbp;	/* non-NULL => contents of new mkdir */
2300 {
2301 	int offset;		/* offset of new entry within directory block */
2302 	ufs_lbn_t lbn;		/* block in directory containing new entry */
2303 	struct fs *fs;
2304 	struct diradd *dap;
2305 	struct pagedep *pagedep;
2306 	struct inodedep *inodedep;
2307 	struct mkdir *mkdir1, *mkdir2;
2308 
2309 	/*
2310 	 * Whiteouts have no dependencies.
2311 	 */
2312 	if (newinum == WINO) {
2313 		if (newdirbp != NULL)
2314 			bdwrite(newdirbp);
2315 		return;
2316 	}
2317 
2318 	fs = dp->i_fs;
2319 	lbn = lblkno(fs, diroffset);
2320 	offset = blkoff(fs, diroffset);
2321 	MALLOC(dap, struct diradd *, sizeof(struct diradd), M_DIRADD,
2322 	    M_SOFTDEP_FLAGS);
2323 	bzero(dap, sizeof(struct diradd));
2324 	dap->da_list.wk_type = D_DIRADD;
2325 	dap->da_offset = offset;
2326 	dap->da_newinum = newinum;
2327 	dap->da_state = ATTACHED;
2328 	if (newdirbp == NULL) {
2329 		dap->da_state |= DEPCOMPLETE;
2330 		ACQUIRE_LOCK(&lk);
2331 	} else {
2332 		dap->da_state |= MKDIR_BODY | MKDIR_PARENT;
2333 		MALLOC(mkdir1, struct mkdir *, sizeof(struct mkdir), M_MKDIR,
2334 		    M_SOFTDEP_FLAGS);
2335 		mkdir1->md_list.wk_type = D_MKDIR;
2336 		mkdir1->md_state = MKDIR_BODY;
2337 		mkdir1->md_diradd = dap;
2338 		MALLOC(mkdir2, struct mkdir *, sizeof(struct mkdir), M_MKDIR,
2339 		    M_SOFTDEP_FLAGS);
2340 		mkdir2->md_list.wk_type = D_MKDIR;
2341 		mkdir2->md_state = MKDIR_PARENT;
2342 		mkdir2->md_diradd = dap;
2343 		/*
2344 		 * Dependency on "." and ".." being written to disk.
2345 		 */
2346 		mkdir1->md_buf = newdirbp;
2347 		ACQUIRE_LOCK(&lk);
2348 		LIST_INSERT_HEAD(&mkdirlisthd, mkdir1, md_mkdirs);
2349 		WORKLIST_INSERT(&newdirbp->b_dep, &mkdir1->md_list);
2350 		FREE_LOCK(&lk);
2351 		bdwrite(newdirbp);
2352 		/*
2353 		 * Dependency on link count increase for parent directory
2354 		 */
2355 		ACQUIRE_LOCK(&lk);
2356 		if (inodedep_lookup(dp->i_fs, dp->i_number, 0, &inodedep) == 0
2357 		    || (inodedep->id_state & ALLCOMPLETE) == ALLCOMPLETE) {
2358 			dap->da_state &= ~MKDIR_PARENT;
2359 			WORKITEM_FREE(mkdir2, D_MKDIR);
2360 		} else {
2361 			LIST_INSERT_HEAD(&mkdirlisthd, mkdir2, md_mkdirs);
2362 			WORKLIST_INSERT(&inodedep->id_bufwait,&mkdir2->md_list);
2363 		}
2364 	}
2365 	/*
2366 	 * Link into parent directory pagedep to await its being written.
2367 	 */
2368 	if (pagedep_lookup(dp, lbn, DEPALLOC, &pagedep) == 0)
2369 		WORKLIST_INSERT(&bp->b_dep, &pagedep->pd_list);
2370 	dap->da_pagedep = pagedep;
2371 	LIST_INSERT_HEAD(&pagedep->pd_diraddhd[DIRADDHASH(offset)], dap,
2372 	    da_pdlist);
2373 	/*
2374 	 * Link into its inodedep. Put it on the id_bufwait list if the inode
2375 	 * is not yet written. If it is written, do the post-inode write
2376 	 * processing to put it on the id_pendinghd list.
2377 	 */
2378 	(void) inodedep_lookup(fs, newinum, DEPALLOC, &inodedep);
2379 	if ((inodedep->id_state & ALLCOMPLETE) == ALLCOMPLETE)
2380 		diradd_inode_written(dap, inodedep);
2381 	else
2382 		WORKLIST_INSERT(&inodedep->id_bufwait, &dap->da_list);
2383 	FREE_LOCK(&lk);
2384 }
2385 
2386 /*
2387  * This procedure is called to change the offset of a directory
2388  * entry when compacting a directory block which must be owned
2389  * exclusively by the caller. Note that the actual entry movement
2390  * must be done in this procedure to ensure that no I/O completions
2391  * occur while the move is in progress.
2392  */
2393 void
2394 softdep_change_directoryentry_offset(dp, base, oldloc, newloc, entrysize)
2395 	struct inode *dp;	/* inode for directory */
2396 	caddr_t base;		/* address of dp->i_offset */
2397 	caddr_t oldloc;		/* address of old directory location */
2398 	caddr_t newloc;		/* address of new directory location */
2399 	int entrysize;		/* size of directory entry */
2400 {
2401 	int offset, oldoffset, newoffset;
2402 	struct pagedep *pagedep;
2403 	struct diradd *dap;
2404 	ufs_lbn_t lbn;
2405 
2406 	ACQUIRE_LOCK(&lk);
2407 	lbn = lblkno(dp->i_fs, dp->i_offset);
2408 	offset = blkoff(dp->i_fs, dp->i_offset);
2409 	if (pagedep_lookup(dp, lbn, 0, &pagedep) == 0)
2410 		goto done;
2411 	oldoffset = offset + (oldloc - base);
2412 	newoffset = offset + (newloc - base);
2413 
2414 	LIST_FOREACH(dap, &pagedep->pd_diraddhd[DIRADDHASH(oldoffset)], da_pdlist) {
2415 		if (dap->da_offset != oldoffset)
2416 			continue;
2417 		dap->da_offset = newoffset;
2418 		if (DIRADDHASH(newoffset) == DIRADDHASH(oldoffset))
2419 			break;
2420 		LIST_REMOVE(dap, da_pdlist);
2421 		LIST_INSERT_HEAD(&pagedep->pd_diraddhd[DIRADDHASH(newoffset)],
2422 		    dap, da_pdlist);
2423 		break;
2424 	}
2425 	if (dap == NULL) {
2426 
2427 		LIST_FOREACH(dap, &pagedep->pd_pendinghd, da_pdlist) {
2428 			if (dap->da_offset == oldoffset) {
2429 				dap->da_offset = newoffset;
2430 				break;
2431 			}
2432 		}
2433 	}
2434 done:
2435 	bcopy(oldloc, newloc, entrysize);
2436 	FREE_LOCK(&lk);
2437 }
2438 
2439 /*
2440  * Free a diradd dependency structure. This routine must be called
2441  * with splbio interrupts blocked.
2442  */
2443 static void
2444 free_diradd(dap)
2445 	struct diradd *dap;
2446 {
2447 	struct dirrem *dirrem;
2448 	struct pagedep *pagedep;
2449 	struct inodedep *inodedep;
2450 	struct mkdir *mkdir, *nextmd;
2451 
2452 #ifdef DEBUG
2453 	if (lk.lkt_held == NOHOLDER)
2454 		panic("free_diradd: lock not held");
2455 #endif
2456 	WORKLIST_REMOVE(&dap->da_list);
2457 	LIST_REMOVE(dap, da_pdlist);
2458 	if ((dap->da_state & DIRCHG) == 0) {
2459 		pagedep = dap->da_pagedep;
2460 	} else {
2461 		dirrem = dap->da_previous;
2462 		pagedep = dirrem->dm_pagedep;
2463 		dirrem->dm_dirinum = pagedep->pd_ino;
2464 		add_to_worklist(&dirrem->dm_list);
2465 	}
2466 	if (inodedep_lookup(VFSTOUFS(pagedep->pd_mnt)->um_fs, dap->da_newinum,
2467 	    0, &inodedep) != 0)
2468 		(void) free_inodedep(inodedep);
2469 	if ((dap->da_state & (MKDIR_PARENT | MKDIR_BODY)) != 0) {
2470 		for (mkdir = LIST_FIRST(&mkdirlisthd); mkdir; mkdir = nextmd) {
2471 			nextmd = LIST_NEXT(mkdir, md_mkdirs);
2472 			if (mkdir->md_diradd != dap)
2473 				continue;
2474 			dap->da_state &= ~mkdir->md_state;
2475 			WORKLIST_REMOVE(&mkdir->md_list);
2476 			LIST_REMOVE(mkdir, md_mkdirs);
2477 			WORKITEM_FREE(mkdir, D_MKDIR);
2478 		}
2479 		if ((dap->da_state & (MKDIR_PARENT | MKDIR_BODY)) != 0) {
2480 			FREE_LOCK(&lk);
2481 			panic("free_diradd: unfound ref");
2482 		}
2483 	}
2484 	WORKITEM_FREE(dap, D_DIRADD);
2485 }
2486 
2487 /*
2488  * Directory entry removal dependencies.
2489  *
2490  * When removing a directory entry, the entry's inode pointer must be
2491  * zero'ed on disk before the corresponding inode's link count is decremented
2492  * (possibly freeing the inode for re-use). This dependency is handled by
2493  * updating the directory entry but delaying the inode count reduction until
2494  * after the directory block has been written to disk. After this point, the
2495  * inode count can be decremented whenever it is convenient.
2496  */
2497 
2498 /*
2499  * This routine should be called immediately after removing
2500  * a directory entry.  The inode's link count should not be
2501  * decremented by the calling procedure -- the soft updates
2502  * code will do this task when it is safe.
2503  */
2504 void
2505 softdep_setup_remove(bp, dp, ip, isrmdir)
2506 	struct buf *bp;		/* buffer containing directory block */
2507 	struct inode *dp;	/* inode for the directory being modified */
2508 	struct inode *ip;	/* inode for directory entry being removed */
2509 	int isrmdir;		/* indicates if doing RMDIR */
2510 {
2511 	struct dirrem *dirrem, *prevdirrem;
2512 
2513 	/*
2514 	 * Allocate a new dirrem if appropriate and ACQUIRE_LOCK.
2515 	 */
2516 	dirrem = newdirrem(bp, dp, ip, isrmdir, &prevdirrem);
2517 
2518 	/*
2519 	 * If the COMPLETE flag is clear, then there were no active
2520 	 * entries and we want to roll back to a zeroed entry until
2521 	 * the new inode is committed to disk. If the COMPLETE flag is
2522 	 * set then we have deleted an entry that never made it to
2523 	 * disk. If the entry we deleted resulted from a name change,
2524 	 * then the old name still resides on disk. We cannot delete
2525 	 * its inode (returned to us in prevdirrem) until the zeroed
2526 	 * directory entry gets to disk. The new inode has never been
2527 	 * referenced on the disk, so can be deleted immediately.
2528 	 */
2529 	if ((dirrem->dm_state & COMPLETE) == 0) {
2530 		LIST_INSERT_HEAD(&dirrem->dm_pagedep->pd_dirremhd, dirrem,
2531 		    dm_next);
2532 		FREE_LOCK(&lk);
2533 	} else {
2534 		if (prevdirrem != NULL)
2535 			LIST_INSERT_HEAD(&dirrem->dm_pagedep->pd_dirremhd,
2536 			    prevdirrem, dm_next);
2537 		dirrem->dm_dirinum = dirrem->dm_pagedep->pd_ino;
2538 		FREE_LOCK(&lk);
2539 		handle_workitem_remove(dirrem);
2540 	}
2541 }
2542 
2543 /*
2544  * Allocate a new dirrem if appropriate and return it along with
2545  * its associated pagedep. Called without a lock, returns with lock.
2546  */
2547 static long num_dirrem;		/* number of dirrem allocated */
2548 static struct dirrem *
2549 newdirrem(bp, dp, ip, isrmdir, prevdirremp)
2550 	struct buf *bp;		/* buffer containing directory block */
2551 	struct inode *dp;	/* inode for the directory being modified */
2552 	struct inode *ip;	/* inode for directory entry being removed */
2553 	int isrmdir;		/* indicates if doing RMDIR */
2554 	struct dirrem **prevdirremp; /* previously referenced inode, if any */
2555 {
2556 	int offset;
2557 	ufs_lbn_t lbn;
2558 	struct diradd *dap;
2559 	struct dirrem *dirrem;
2560 	struct pagedep *pagedep;
2561 
2562 	/*
2563 	 * Whiteouts have no deletion dependencies.
2564 	 */
2565 	if (ip == NULL)
2566 		panic("newdirrem: whiteout");
2567 	/*
2568 	 * If we are over our limit, try to improve the situation.
2569 	 * Limiting the number of dirrem structures will also limit
2570 	 * the number of freefile and freeblks structures.
2571 	 */
2572 	if (num_dirrem > max_softdeps / 2 && speedup_syncer() == 0)
2573 		(void) request_cleanup(FLUSH_REMOVE, 0);
2574 	num_dirrem += 1;
2575 	MALLOC(dirrem, struct dirrem *, sizeof(struct dirrem),
2576 		M_DIRREM, M_SOFTDEP_FLAGS);
2577 	bzero(dirrem, sizeof(struct dirrem));
2578 	dirrem->dm_list.wk_type = D_DIRREM;
2579 	dirrem->dm_state = isrmdir ? RMDIR : 0;
2580 	dirrem->dm_mnt = ITOV(ip)->v_mount;
2581 	dirrem->dm_oldinum = ip->i_number;
2582 	*prevdirremp = NULL;
2583 
2584 	ACQUIRE_LOCK(&lk);
2585 	lbn = lblkno(dp->i_fs, dp->i_offset);
2586 	offset = blkoff(dp->i_fs, dp->i_offset);
2587 	if (pagedep_lookup(dp, lbn, DEPALLOC, &pagedep) == 0)
2588 		WORKLIST_INSERT(&bp->b_dep, &pagedep->pd_list);
2589 	dirrem->dm_pagedep = pagedep;
2590 	/*
2591 	 * Check for a diradd dependency for the same directory entry.
2592 	 * If present, then both dependencies become obsolete and can
2593 	 * be de-allocated. Check for an entry on both the pd_dirraddhd
2594 	 * list and the pd_pendinghd list.
2595 	 */
2596 
2597 	LIST_FOREACH(dap, &pagedep->pd_diraddhd[DIRADDHASH(offset)], da_pdlist)
2598 		if (dap->da_offset == offset)
2599 			break;
2600 	if (dap == NULL) {
2601 
2602 		LIST_FOREACH(dap, &pagedep->pd_pendinghd, da_pdlist)
2603 			if (dap->da_offset == offset)
2604 				break;
2605 		if (dap == NULL)
2606 			return (dirrem);
2607 	}
2608 	/*
2609 	 * Must be ATTACHED at this point.
2610 	 */
2611 	if ((dap->da_state & ATTACHED) == 0) {
2612 		FREE_LOCK(&lk);
2613 		panic("newdirrem: not ATTACHED");
2614 	}
2615 	if (dap->da_newinum != ip->i_number) {
2616 		FREE_LOCK(&lk);
2617 		panic("newdirrem: inum %d should be %d",
2618 		    ip->i_number, dap->da_newinum);
2619 	}
2620 	/*
2621 	 * If we are deleting a changed name that never made it to disk,
2622 	 * then return the dirrem describing the previous inode (which
2623 	 * represents the inode currently referenced from this entry on disk).
2624 	 */
2625 	if ((dap->da_state & DIRCHG) != 0) {
2626 		*prevdirremp = dap->da_previous;
2627 		dap->da_state &= ~DIRCHG;
2628 		dap->da_pagedep = pagedep;
2629 	}
2630 	/*
2631 	 * We are deleting an entry that never made it to disk.
2632 	 * Mark it COMPLETE so we can delete its inode immediately.
2633 	 */
2634 	dirrem->dm_state |= COMPLETE;
2635 	free_diradd(dap);
2636 	return (dirrem);
2637 }
2638 
2639 /*
2640  * Directory entry change dependencies.
2641  *
2642  * Changing an existing directory entry requires that an add operation
2643  * be completed first followed by a deletion. The semantics for the addition
2644  * are identical to the description of adding a new entry above except
2645  * that the rollback is to the old inode number rather than zero. Once
2646  * the addition dependency is completed, the removal is done as described
2647  * in the removal routine above.
2648  */
2649 
2650 /*
2651  * This routine should be called immediately after changing
2652  * a directory entry.  The inode's link count should not be
2653  * decremented by the calling procedure -- the soft updates
2654  * code will perform this task when it is safe.
2655  */
2656 void
2657 softdep_setup_directory_change(bp, dp, ip, newinum, isrmdir)
2658 	struct buf *bp;		/* buffer containing directory block */
2659 	struct inode *dp;	/* inode for the directory being modified */
2660 	struct inode *ip;	/* inode for directory entry being removed */
2661 	long newinum;		/* new inode number for changed entry */
2662 	int isrmdir;		/* indicates if doing RMDIR */
2663 {
2664 	int offset;
2665 	struct diradd *dap = NULL;
2666 	struct dirrem *dirrem, *prevdirrem;
2667 	struct pagedep *pagedep;
2668 	struct inodedep *inodedep;
2669 
2670 	offset = blkoff(dp->i_fs, dp->i_offset);
2671 
2672 	/*
2673 	 * Whiteouts do not need diradd dependencies.
2674 	 */
2675 	if (newinum != WINO) {
2676 		MALLOC(dap, struct diradd *, sizeof(struct diradd),
2677 		    M_DIRADD, M_SOFTDEP_FLAGS);
2678 		bzero(dap, sizeof(struct diradd));
2679 		dap->da_list.wk_type = D_DIRADD;
2680 		dap->da_state = DIRCHG | ATTACHED | DEPCOMPLETE;
2681 		dap->da_offset = offset;
2682 		dap->da_newinum = newinum;
2683 	}
2684 
2685 	/*
2686 	 * Allocate a new dirrem and ACQUIRE_LOCK.
2687 	 */
2688 	dirrem = newdirrem(bp, dp, ip, isrmdir, &prevdirrem);
2689 	pagedep = dirrem->dm_pagedep;
2690 	/*
2691 	 * The possible values for isrmdir:
2692 	 *	0 - non-directory file rename
2693 	 *	1 - directory rename within same directory
2694 	 *   inum - directory rename to new directory of given inode number
2695 	 * When renaming to a new directory, we are both deleting and
2696 	 * creating a new directory entry, so the link count on the new
2697 	 * directory should not change. Thus we do not need the followup
2698 	 * dirrem which is usually done in handle_workitem_remove. We set
2699 	 * the DIRCHG flag to tell handle_workitem_remove to skip the
2700 	 * followup dirrem.
2701 	 */
2702 	if (isrmdir > 1)
2703 		dirrem->dm_state |= DIRCHG;
2704 
2705 	/*
2706 	 * Whiteouts have no additional dependencies,
2707 	 * so just put the dirrem on the correct list.
2708 	 */
2709 	if (newinum == WINO) {
2710 		if ((dirrem->dm_state & COMPLETE) == 0) {
2711 			LIST_INSERT_HEAD(&pagedep->pd_dirremhd, dirrem,
2712 			    dm_next);
2713 		} else {
2714 			dirrem->dm_dirinum = pagedep->pd_ino;
2715 			add_to_worklist(&dirrem->dm_list);
2716 		}
2717 		FREE_LOCK(&lk);
2718 		return;
2719 	}
2720 
2721 	/*
2722 	 * If the COMPLETE flag is clear, then there were no active
2723 	 * entries and we want to roll back to the previous inode until
2724 	 * the new inode is committed to disk. If the COMPLETE flag is
2725 	 * set, then we have deleted an entry that never made it to disk.
2726 	 * If the entry we deleted resulted from a name change, then the old
2727 	 * inode reference still resides on disk. Any rollback that we do
2728 	 * needs to be to that old inode (returned to us in prevdirrem). If
2729 	 * the entry we deleted resulted from a create, then there is
2730 	 * no entry on the disk, so we want to roll back to zero rather
2731 	 * than the uncommitted inode. In either of the COMPLETE cases we
2732 	 * want to immediately free the unwritten and unreferenced inode.
2733 	 */
2734 	if ((dirrem->dm_state & COMPLETE) == 0) {
2735 		dap->da_previous = dirrem;
2736 	} else {
2737 		if (prevdirrem != NULL) {
2738 			dap->da_previous = prevdirrem;
2739 		} else {
2740 			dap->da_state &= ~DIRCHG;
2741 			dap->da_pagedep = pagedep;
2742 		}
2743 		dirrem->dm_dirinum = pagedep->pd_ino;
2744 		add_to_worklist(&dirrem->dm_list);
2745 	}
2746 	/*
2747 	 * Link into its inodedep. Put it on the id_bufwait list if the inode
2748 	 * is not yet written. If it is written, do the post-inode write
2749 	 * processing to put it on the id_pendinghd list.
2750 	 */
2751 	if (inodedep_lookup(dp->i_fs, newinum, DEPALLOC, &inodedep) == 0 ||
2752 	    (inodedep->id_state & ALLCOMPLETE) == ALLCOMPLETE) {
2753 		dap->da_state |= COMPLETE;
2754 		LIST_INSERT_HEAD(&pagedep->pd_pendinghd, dap, da_pdlist);
2755 		WORKLIST_INSERT(&inodedep->id_pendinghd, &dap->da_list);
2756 	} else {
2757 		LIST_INSERT_HEAD(&pagedep->pd_diraddhd[DIRADDHASH(offset)],
2758 		    dap, da_pdlist);
2759 		WORKLIST_INSERT(&inodedep->id_bufwait, &dap->da_list);
2760 	}
2761 	FREE_LOCK(&lk);
2762 }
2763 
2764 /*
2765  * Called whenever the link count on an inode is changed.
2766  * It creates an inode dependency so that the new reference(s)
2767  * to the inode cannot be committed to disk until the updated
2768  * inode has been written.
2769  */
2770 void
2771 softdep_change_linkcnt(ip)
2772 	struct inode *ip;	/* the inode with the increased link count */
2773 {
2774 	struct inodedep *inodedep;
2775 
2776 	ACQUIRE_LOCK(&lk);
2777 	(void) inodedep_lookup(ip->i_fs, ip->i_number, DEPALLOC, &inodedep);
2778 	if (ip->i_nlink < ip->i_effnlink) {
2779 		FREE_LOCK(&lk);
2780 		panic("softdep_change_linkcnt: bad delta");
2781 	}
2782 	inodedep->id_nlinkdelta = ip->i_nlink - ip->i_effnlink;
2783 	FREE_LOCK(&lk);
2784 }
2785 
2786 /*
2787  * This workitem decrements the inode's link count.
2788  * If the link count reaches zero, the file is removed.
2789  */
2790 static void
2791 handle_workitem_remove(dirrem)
2792 	struct dirrem *dirrem;
2793 {
2794 	struct thread *td = curthread;	/* XXX */
2795 	struct inodedep *inodedep;
2796 	struct vnode *vp;
2797 	struct inode *ip;
2798 	ino_t oldinum;
2799 	int error;
2800 
2801 	if ((error = VFS_VGET(dirrem->dm_mnt, dirrem->dm_oldinum, &vp)) != 0) {
2802 		softdep_error("handle_workitem_remove: vget", error);
2803 		return;
2804 	}
2805 	ip = VTOI(vp);
2806 	ACQUIRE_LOCK(&lk);
2807 	if ((inodedep_lookup(ip->i_fs, dirrem->dm_oldinum, 0, &inodedep)) == 0){
2808 		FREE_LOCK(&lk);
2809 		panic("handle_workitem_remove: lost inodedep");
2810 	}
2811 	/*
2812 	 * Normal file deletion.
2813 	 */
2814 	if ((dirrem->dm_state & RMDIR) == 0) {
2815 		ip->i_nlink--;
2816 		ip->i_flag |= IN_CHANGE;
2817 		if (ip->i_nlink < ip->i_effnlink) {
2818 			FREE_LOCK(&lk);
2819 			panic("handle_workitem_remove: bad file delta");
2820 		}
2821 		inodedep->id_nlinkdelta = ip->i_nlink - ip->i_effnlink;
2822 		FREE_LOCK(&lk);
2823 		vput(vp);
2824 		num_dirrem -= 1;
2825 		WORKITEM_FREE(dirrem, D_DIRREM);
2826 		return;
2827 	}
2828 	/*
2829 	 * Directory deletion. Decrement reference count for both the
2830 	 * just deleted parent directory entry and the reference for ".".
2831 	 * Next truncate the directory to length zero. When the
2832 	 * truncation completes, arrange to have the reference count on
2833 	 * the parent decremented to account for the loss of "..".
2834 	 */
2835 	ip->i_nlink -= 2;
2836 	ip->i_flag |= IN_CHANGE;
2837 	if (ip->i_nlink < ip->i_effnlink) {
2838 		FREE_LOCK(&lk);
2839 		panic("handle_workitem_remove: bad dir delta");
2840 	}
2841 	inodedep->id_nlinkdelta = ip->i_nlink - ip->i_effnlink;
2842 	FREE_LOCK(&lk);
2843 	if ((error = UFS_TRUNCATE(vp, (off_t)0, 0, proc0.p_ucred, td)) != 0)
2844 		softdep_error("handle_workitem_remove: truncate", error);
2845 	/*
2846 	 * Rename a directory to a new parent. Since, we are both deleting
2847 	 * and creating a new directory entry, the link count on the new
2848 	 * directory should not change. Thus we skip the followup dirrem.
2849 	 */
2850 	if (dirrem->dm_state & DIRCHG) {
2851 		vput(vp);
2852 		num_dirrem -= 1;
2853 		WORKITEM_FREE(dirrem, D_DIRREM);
2854 		return;
2855 	}
2856 	/*
2857 	 * If the inodedep does not exist, then the zero'ed inode has
2858 	 * been written to disk. If the allocated inode has never been
2859 	 * written to disk, then the on-disk inode is zero'ed. In either
2860 	 * case we can remove the file immediately.
2861 	 */
2862 	ACQUIRE_LOCK(&lk);
2863 	dirrem->dm_state = 0;
2864 	oldinum = dirrem->dm_oldinum;
2865 	dirrem->dm_oldinum = dirrem->dm_dirinum;
2866 	if (inodedep_lookup(ip->i_fs, oldinum, 0, &inodedep) == 0 ||
2867 	    check_inode_unwritten(inodedep)) {
2868 		FREE_LOCK(&lk);
2869 		vput(vp);
2870 		handle_workitem_remove(dirrem);
2871 		return;
2872 	}
2873 	WORKLIST_INSERT(&inodedep->id_inowait, &dirrem->dm_list);
2874 	FREE_LOCK(&lk);
2875 	vput(vp);
2876 }
2877 
2878 /*
2879  * Inode de-allocation dependencies.
2880  *
2881  * When an inode's link count is reduced to zero, it can be de-allocated. We
2882  * found it convenient to postpone de-allocation until after the inode is
2883  * written to disk with its new link count (zero).  At this point, all of the
2884  * on-disk inode's block pointers are nullified and, with careful dependency
2885  * list ordering, all dependencies related to the inode will be satisfied and
2886  * the corresponding dependency structures de-allocated.  So, if/when the
2887  * inode is reused, there will be no mixing of old dependencies with new
2888  * ones.  This artificial dependency is set up by the block de-allocation
2889  * procedure above (softdep_setup_freeblocks) and completed by the
2890  * following procedure.
2891  */
2892 static void
2893 handle_workitem_freefile(freefile)
2894 	struct freefile *freefile;
2895 {
2896 	struct vnode vp;
2897 	struct inode tip;
2898 	struct inodedep *idp;
2899 	int error;
2900 
2901 #ifdef DEBUG
2902 	ACQUIRE_LOCK(&lk);
2903 	error = inodedep_lookup(freefile->fx_fs, freefile->fx_oldinum, 0, &idp);
2904 	FREE_LOCK(&lk);
2905 	if (error)
2906 		panic("handle_workitem_freefile: inodedep survived");
2907 #endif
2908 	tip.i_devvp = freefile->fx_devvp;
2909 	tip.i_dev = freefile->fx_devvp->v_rdev;
2910 	tip.i_fs = freefile->fx_fs;
2911 	vp.v_data = &tip;
2912 	if ((error = ffs_freefile(&vp, freefile->fx_oldinum, freefile->fx_mode)) != 0)
2913 		softdep_error("handle_workitem_freefile", error);
2914 	WORKITEM_FREE(freefile, D_FREEFILE);
2915 }
2916 
2917 /*
2918  * Disk writes.
2919  *
2920  * The dependency structures constructed above are most actively used when file
2921  * system blocks are written to disk.  No constraints are placed on when a
2922  * block can be written, but unsatisfied update dependencies are made safe by
2923  * modifying (or replacing) the source memory for the duration of the disk
2924  * write.  When the disk write completes, the memory block is again brought
2925  * up-to-date.
2926  *
2927  * In-core inode structure reclamation.
2928  *
2929  * Because there are a finite number of "in-core" inode structures, they are
2930  * reused regularly.  By transferring all inode-related dependencies to the
2931  * in-memory inode block and indexing them separately (via "inodedep"s), we
2932  * can allow "in-core" inode structures to be reused at any time and avoid
2933  * any increase in contention.
2934  *
2935  * Called just before entering the device driver to initiate a new disk I/O.
2936  * The buffer must be locked, thus, no I/O completion operations can occur
2937  * while we are manipulating its associated dependencies.
2938  */
2939 static void
2940 softdep_disk_io_initiation(bp)
2941 	struct buf *bp;		/* structure describing disk write to occur */
2942 {
2943 	struct worklist *wk, *nextwk;
2944 	struct indirdep *indirdep;
2945 
2946 	/*
2947 	 * We only care about write operations. There should never
2948 	 * be dependencies for reads.
2949 	 */
2950 	if (bp->b_flags & B_READ)
2951 		panic("softdep_disk_io_initiation: read");
2952 	/*
2953 	 * Do any necessary pre-I/O processing.
2954 	 */
2955 	for (wk = LIST_FIRST(&bp->b_dep); wk; wk = nextwk) {
2956 		nextwk = LIST_NEXT(wk, wk_list);
2957 		switch (wk->wk_type) {
2958 
2959 		case D_PAGEDEP:
2960 			initiate_write_filepage(WK_PAGEDEP(wk), bp);
2961 			continue;
2962 
2963 		case D_INODEDEP:
2964 			initiate_write_inodeblock(WK_INODEDEP(wk), bp);
2965 			continue;
2966 
2967 		case D_INDIRDEP:
2968 			indirdep = WK_INDIRDEP(wk);
2969 			if (indirdep->ir_state & GOINGAWAY)
2970 				panic("disk_io_initiation: indirdep gone");
2971 			/*
2972 			 * If there are no remaining dependencies, this
2973 			 * will be writing the real pointers, so the
2974 			 * dependency can be freed.
2975 			 */
2976 			if (LIST_FIRST(&indirdep->ir_deplisthd) == NULL) {
2977 				indirdep->ir_savebp->b_flags |= B_INVAL | B_NOCACHE;
2978 				brelse(indirdep->ir_savebp);
2979 				/* inline expand WORKLIST_REMOVE(wk); */
2980 				wk->wk_state &= ~ONWORKLIST;
2981 				LIST_REMOVE(wk, wk_list);
2982 				WORKITEM_FREE(indirdep, D_INDIRDEP);
2983 				continue;
2984 			}
2985 			/*
2986 			 * Replace up-to-date version with safe version.
2987 			 */
2988 			MALLOC(indirdep->ir_saveddata, caddr_t, bp->b_bcount,
2989 			    M_INDIRDEP, M_SOFTDEP_FLAGS);
2990 			ACQUIRE_LOCK(&lk);
2991 			indirdep->ir_state &= ~ATTACHED;
2992 			indirdep->ir_state |= UNDONE;
2993 			bcopy(bp->b_data, indirdep->ir_saveddata, bp->b_bcount);
2994 			bcopy(indirdep->ir_savebp->b_data, bp->b_data,
2995 			    bp->b_bcount);
2996 			FREE_LOCK(&lk);
2997 			continue;
2998 
2999 		case D_MKDIR:
3000 		case D_BMSAFEMAP:
3001 		case D_ALLOCDIRECT:
3002 		case D_ALLOCINDIR:
3003 			continue;
3004 
3005 		default:
3006 			panic("handle_disk_io_initiation: Unexpected type %s",
3007 			    TYPENAME(wk->wk_type));
3008 			/* NOTREACHED */
3009 		}
3010 	}
3011 }
3012 
3013 /*
3014  * Called from within the procedure above to deal with unsatisfied
3015  * allocation dependencies in a directory. The buffer must be locked,
3016  * thus, no I/O completion operations can occur while we are
3017  * manipulating its associated dependencies.
3018  */
3019 static void
3020 initiate_write_filepage(pagedep, bp)
3021 	struct pagedep *pagedep;
3022 	struct buf *bp;
3023 {
3024 	struct diradd *dap;
3025 	struct direct *ep;
3026 	int i;
3027 
3028 	if (pagedep->pd_state & IOSTARTED) {
3029 		/*
3030 		 * This can only happen if there is a driver that does not
3031 		 * understand chaining. Here biodone will reissue the call
3032 		 * to strategy for the incomplete buffers.
3033 		 */
3034 		printf("initiate_write_filepage: already started\n");
3035 		return;
3036 	}
3037 	pagedep->pd_state |= IOSTARTED;
3038 	ACQUIRE_LOCK(&lk);
3039 	for (i = 0; i < DAHASHSZ; i++) {
3040 		LIST_FOREACH(dap, &pagedep->pd_diraddhd[i], da_pdlist) {
3041 			ep = (struct direct *)
3042 			    ((char *)bp->b_data + dap->da_offset);
3043 			if (ep->d_ino != dap->da_newinum) {
3044 				FREE_LOCK(&lk);
3045 				panic("%s: dir inum %d != new %d",
3046 				    "initiate_write_filepage",
3047 				    ep->d_ino, dap->da_newinum);
3048 			}
3049 			if (dap->da_state & DIRCHG)
3050 				ep->d_ino = dap->da_previous->dm_oldinum;
3051 			else
3052 				ep->d_ino = 0;
3053 			dap->da_state &= ~ATTACHED;
3054 			dap->da_state |= UNDONE;
3055 		}
3056 	}
3057 	FREE_LOCK(&lk);
3058 }
3059 
3060 /*
3061  * Called from within the procedure above to deal with unsatisfied
3062  * allocation dependencies in an inodeblock. The buffer must be
3063  * locked, thus, no I/O completion operations can occur while we
3064  * are manipulating its associated dependencies.
3065  */
3066 static void
3067 initiate_write_inodeblock(inodedep, bp)
3068 	struct inodedep *inodedep;
3069 	struct buf *bp;			/* The inode block */
3070 {
3071 	struct allocdirect *adp, *lastadp;
3072 	struct dinode *dp;
3073 	struct fs *fs;
3074 	ufs_lbn_t prevlbn = 0;
3075 	int i, deplist;
3076 
3077 	if (inodedep->id_state & IOSTARTED)
3078 		panic("initiate_write_inodeblock: already started");
3079 	inodedep->id_state |= IOSTARTED;
3080 	fs = inodedep->id_fs;
3081 	dp = (struct dinode *)bp->b_data +
3082 	    ino_to_fsbo(fs, inodedep->id_ino);
3083 	/*
3084 	 * If the bitmap is not yet written, then the allocated
3085 	 * inode cannot be written to disk.
3086 	 */
3087 	if ((inodedep->id_state & DEPCOMPLETE) == 0) {
3088 		if (inodedep->id_savedino != NULL)
3089 			panic("initiate_write_inodeblock: already doing I/O");
3090 		MALLOC(inodedep->id_savedino, struct dinode *,
3091 		    sizeof(struct dinode), M_INODEDEP, M_SOFTDEP_FLAGS);
3092 		*inodedep->id_savedino = *dp;
3093 		bzero((caddr_t)dp, sizeof(struct dinode));
3094 		return;
3095 	}
3096 	/*
3097 	 * If no dependencies, then there is nothing to roll back.
3098 	 */
3099 	inodedep->id_savedsize = dp->di_size;
3100 	if (TAILQ_FIRST(&inodedep->id_inoupdt) == NULL)
3101 		return;
3102 	/*
3103 	 * Set the dependencies to busy.
3104 	 */
3105 	ACQUIRE_LOCK(&lk);
3106 	for (deplist = 0, adp = TAILQ_FIRST(&inodedep->id_inoupdt); adp;
3107 	     adp = TAILQ_NEXT(adp, ad_next)) {
3108 #ifdef DIAGNOSTIC
3109 		if (deplist != 0 && prevlbn >= adp->ad_lbn) {
3110 			FREE_LOCK(&lk);
3111 			panic("softdep_write_inodeblock: lbn order");
3112 		}
3113 		prevlbn = adp->ad_lbn;
3114 		if (adp->ad_lbn < NDADDR &&
3115 		    dp->di_db[adp->ad_lbn] != adp->ad_newblkno) {
3116 			FREE_LOCK(&lk);
3117 			panic("%s: direct pointer #%ld mismatch %d != %d",
3118 			    "softdep_write_inodeblock", adp->ad_lbn,
3119 			    dp->di_db[adp->ad_lbn], adp->ad_newblkno);
3120 		}
3121 		if (adp->ad_lbn >= NDADDR &&
3122 		    dp->di_ib[adp->ad_lbn - NDADDR] != adp->ad_newblkno) {
3123 			FREE_LOCK(&lk);
3124 			panic("%s: indirect pointer #%ld mismatch %d != %d",
3125 			    "softdep_write_inodeblock", adp->ad_lbn - NDADDR,
3126 			    dp->di_ib[adp->ad_lbn - NDADDR], adp->ad_newblkno);
3127 		}
3128 		deplist |= 1 << adp->ad_lbn;
3129 		if ((adp->ad_state & ATTACHED) == 0) {
3130 			FREE_LOCK(&lk);
3131 			panic("softdep_write_inodeblock: Unknown state 0x%x",
3132 			    adp->ad_state);
3133 		}
3134 #endif /* DIAGNOSTIC */
3135 		adp->ad_state &= ~ATTACHED;
3136 		adp->ad_state |= UNDONE;
3137 	}
3138 	/*
3139 	 * The on-disk inode cannot claim to be any larger than the last
3140 	 * fragment that has been written. Otherwise, the on-disk inode
3141 	 * might have fragments that were not the last block in the file
3142 	 * which would corrupt the filesystem.
3143 	 */
3144 	for (lastadp = NULL, adp = TAILQ_FIRST(&inodedep->id_inoupdt); adp;
3145 	     lastadp = adp, adp = TAILQ_NEXT(adp, ad_next)) {
3146 		if (adp->ad_lbn >= NDADDR)
3147 			break;
3148 		dp->di_db[adp->ad_lbn] = adp->ad_oldblkno;
3149 		/* keep going until hitting a rollback to a frag */
3150 		if (adp->ad_oldsize == 0 || adp->ad_oldsize == fs->fs_bsize)
3151 			continue;
3152 		dp->di_size = fs->fs_bsize * adp->ad_lbn + adp->ad_oldsize;
3153 		for (i = adp->ad_lbn + 1; i < NDADDR; i++) {
3154 #ifdef DIAGNOSTIC
3155 			if (dp->di_db[i] != 0 && (deplist & (1 << i)) == 0) {
3156 				FREE_LOCK(&lk);
3157 				panic("softdep_write_inodeblock: lost dep1");
3158 			}
3159 #endif /* DIAGNOSTIC */
3160 			dp->di_db[i] = 0;
3161 		}
3162 		for (i = 0; i < NIADDR; i++) {
3163 #ifdef DIAGNOSTIC
3164 			if (dp->di_ib[i] != 0 &&
3165 			    (deplist & ((1 << NDADDR) << i)) == 0) {
3166 				FREE_LOCK(&lk);
3167 				panic("softdep_write_inodeblock: lost dep2");
3168 			}
3169 #endif /* DIAGNOSTIC */
3170 			dp->di_ib[i] = 0;
3171 		}
3172 		FREE_LOCK(&lk);
3173 		return;
3174 	}
3175 	/*
3176 	 * If we have zero'ed out the last allocated block of the file,
3177 	 * roll back the size to the last currently allocated block.
3178 	 * We know that this last allocated block is a full-sized as
3179 	 * we already checked for fragments in the loop above.
3180 	 */
3181 	if (lastadp != NULL &&
3182 	    dp->di_size <= (lastadp->ad_lbn + 1) * fs->fs_bsize) {
3183 		for (i = lastadp->ad_lbn; i >= 0; i--)
3184 			if (dp->di_db[i] != 0)
3185 				break;
3186 		dp->di_size = (i + 1) * fs->fs_bsize;
3187 	}
3188 	/*
3189 	 * The only dependencies are for indirect blocks.
3190 	 *
3191 	 * The file size for indirect block additions is not guaranteed.
3192 	 * Such a guarantee would be non-trivial to achieve. The conventional
3193 	 * synchronous write implementation also does not make this guarantee.
3194 	 * Fsck should catch and fix discrepancies. Arguably, the file size
3195 	 * can be over-estimated without destroying integrity when the file
3196 	 * moves into the indirect blocks (i.e., is large). If we want to
3197 	 * postpone fsck, we are stuck with this argument.
3198 	 */
3199 	for (; adp; adp = TAILQ_NEXT(adp, ad_next))
3200 		dp->di_ib[adp->ad_lbn - NDADDR] = 0;
3201 	FREE_LOCK(&lk);
3202 }
3203 
3204 /*
3205  * This routine is called during the completion interrupt
3206  * service routine for a disk write (from the procedure called
3207  * by the device driver to inform the file system caches of
3208  * a request completion).  It should be called early in this
3209  * procedure, before the block is made available to other
3210  * processes or other routines are called.
3211  */
3212 static void
3213 softdep_disk_write_complete(bp)
3214 	struct buf *bp;		/* describes the completed disk write */
3215 {
3216 	struct worklist *wk;
3217 	struct workhead reattach;
3218 	struct newblk *newblk;
3219 	struct allocindir *aip;
3220 	struct allocdirect *adp;
3221 	struct indirdep *indirdep;
3222 	struct inodedep *inodedep;
3223 	struct bmsafemap *bmsafemap;
3224 
3225 #ifdef DEBUG
3226 	if (lk.lkt_held != NOHOLDER)
3227 		panic("softdep_disk_write_complete: lock is held");
3228 	lk.lkt_held = SPECIAL_FLAG;
3229 #endif
3230 	LIST_INIT(&reattach);
3231 	while ((wk = LIST_FIRST(&bp->b_dep)) != NULL) {
3232 		WORKLIST_REMOVE(wk);
3233 		switch (wk->wk_type) {
3234 
3235 		case D_PAGEDEP:
3236 			if (handle_written_filepage(WK_PAGEDEP(wk), bp))
3237 				WORKLIST_INSERT(&reattach, wk);
3238 			continue;
3239 
3240 		case D_INODEDEP:
3241 			if (handle_written_inodeblock(WK_INODEDEP(wk), bp))
3242 				WORKLIST_INSERT(&reattach, wk);
3243 			continue;
3244 
3245 		case D_BMSAFEMAP:
3246 			bmsafemap = WK_BMSAFEMAP(wk);
3247 			while ((newblk = LIST_FIRST(&bmsafemap->sm_newblkhd))) {
3248 				newblk->nb_state |= DEPCOMPLETE;
3249 				newblk->nb_bmsafemap = NULL;
3250 				LIST_REMOVE(newblk, nb_deps);
3251 			}
3252 			while ((adp =
3253 			   LIST_FIRST(&bmsafemap->sm_allocdirecthd))) {
3254 				adp->ad_state |= DEPCOMPLETE;
3255 				adp->ad_buf = NULL;
3256 				LIST_REMOVE(adp, ad_deps);
3257 				handle_allocdirect_partdone(adp);
3258 			}
3259 			while ((aip =
3260 			    LIST_FIRST(&bmsafemap->sm_allocindirhd))) {
3261 				aip->ai_state |= DEPCOMPLETE;
3262 				aip->ai_buf = NULL;
3263 				LIST_REMOVE(aip, ai_deps);
3264 				handle_allocindir_partdone(aip);
3265 			}
3266 			while ((inodedep =
3267 			     LIST_FIRST(&bmsafemap->sm_inodedephd)) != NULL) {
3268 				inodedep->id_state |= DEPCOMPLETE;
3269 				LIST_REMOVE(inodedep, id_deps);
3270 				inodedep->id_buf = NULL;
3271 			}
3272 			WORKITEM_FREE(bmsafemap, D_BMSAFEMAP);
3273 			continue;
3274 
3275 		case D_MKDIR:
3276 			handle_written_mkdir(WK_MKDIR(wk), MKDIR_BODY);
3277 			continue;
3278 
3279 		case D_ALLOCDIRECT:
3280 			adp = WK_ALLOCDIRECT(wk);
3281 			adp->ad_state |= COMPLETE;
3282 			handle_allocdirect_partdone(adp);
3283 			continue;
3284 
3285 		case D_ALLOCINDIR:
3286 			aip = WK_ALLOCINDIR(wk);
3287 			aip->ai_state |= COMPLETE;
3288 			handle_allocindir_partdone(aip);
3289 			continue;
3290 
3291 		case D_INDIRDEP:
3292 			indirdep = WK_INDIRDEP(wk);
3293 			if (indirdep->ir_state & GOINGAWAY) {
3294 				lk.lkt_held = NOHOLDER;
3295 				panic("disk_write_complete: indirdep gone");
3296 			}
3297 			bcopy(indirdep->ir_saveddata, bp->b_data, bp->b_bcount);
3298 			FREE(indirdep->ir_saveddata, M_INDIRDEP);
3299 			indirdep->ir_saveddata = 0;
3300 			indirdep->ir_state &= ~UNDONE;
3301 			indirdep->ir_state |= ATTACHED;
3302 			while ((aip = LIST_FIRST(&indirdep->ir_donehd)) != 0) {
3303 				handle_allocindir_partdone(aip);
3304 				if (aip == LIST_FIRST(&indirdep->ir_donehd)) {
3305 					lk.lkt_held = NOHOLDER;
3306 					panic("disk_write_complete: not gone");
3307 				}
3308 			}
3309 			WORKLIST_INSERT(&reattach, wk);
3310 			if ((bp->b_flags & B_DELWRI) == 0)
3311 				stat_indir_blk_ptrs++;
3312 			bdirty(bp);
3313 			continue;
3314 
3315 		default:
3316 			lk.lkt_held = NOHOLDER;
3317 			panic("handle_disk_write_complete: Unknown type %s",
3318 			    TYPENAME(wk->wk_type));
3319 			/* NOTREACHED */
3320 		}
3321 	}
3322 	/*
3323 	 * Reattach any requests that must be redone.
3324 	 */
3325 	while ((wk = LIST_FIRST(&reattach)) != NULL) {
3326 		WORKLIST_REMOVE(wk);
3327 		WORKLIST_INSERT(&bp->b_dep, wk);
3328 	}
3329 #ifdef DEBUG
3330 	if (lk.lkt_held != SPECIAL_FLAG)
3331 		panic("softdep_disk_write_complete: lock lost");
3332 	lk.lkt_held = NOHOLDER;
3333 #endif
3334 }
3335 
3336 /*
3337  * Called from within softdep_disk_write_complete above. Note that
3338  * this routine is always called from interrupt level with further
3339  * splbio interrupts blocked.
3340  */
3341 static void
3342 handle_allocdirect_partdone(adp)
3343 	struct allocdirect *adp;	/* the completed allocdirect */
3344 {
3345 	struct allocdirect *listadp;
3346 	struct inodedep *inodedep;
3347 	long bsize;
3348 
3349 	if ((adp->ad_state & ALLCOMPLETE) != ALLCOMPLETE)
3350 		return;
3351 	if (adp->ad_buf != NULL) {
3352 		lk.lkt_held = NOHOLDER;
3353 		panic("handle_allocdirect_partdone: dangling dep");
3354 	}
3355 	/*
3356 	 * The on-disk inode cannot claim to be any larger than the last
3357 	 * fragment that has been written. Otherwise, the on-disk inode
3358 	 * might have fragments that were not the last block in the file
3359 	 * which would corrupt the filesystem. Thus, we cannot free any
3360 	 * allocdirects after one whose ad_oldblkno claims a fragment as
3361 	 * these blocks must be rolled back to zero before writing the inode.
3362 	 * We check the currently active set of allocdirects in id_inoupdt.
3363 	 */
3364 	inodedep = adp->ad_inodedep;
3365 	bsize = inodedep->id_fs->fs_bsize;
3366 	TAILQ_FOREACH(listadp, &inodedep->id_inoupdt, ad_next) {
3367 		/* found our block */
3368 		if (listadp == adp)
3369 			break;
3370 		/* continue if ad_oldlbn is not a fragment */
3371 		if (listadp->ad_oldsize == 0 ||
3372 		    listadp->ad_oldsize == bsize)
3373 			continue;
3374 		/* hit a fragment */
3375 		return;
3376 	}
3377 	/*
3378 	 * If we have reached the end of the current list without
3379 	 * finding the just finished dependency, then it must be
3380 	 * on the future dependency list. Future dependencies cannot
3381 	 * be freed until they are moved to the current list.
3382 	 */
3383 	if (listadp == NULL) {
3384 #ifdef DEBUG
3385 		TAILQ_FOREACH(listadp, &inodedep->id_newinoupdt, ad_next)
3386 			/* found our block */
3387 			if (listadp == adp)
3388 				break;
3389 		if (listadp == NULL) {
3390 			lk.lkt_held = NOHOLDER;
3391 			panic("handle_allocdirect_partdone: lost dep");
3392 		}
3393 #endif /* DEBUG */
3394 		return;
3395 	}
3396 	/*
3397 	 * If we have found the just finished dependency, then free
3398 	 * it along with anything that follows it that is complete.
3399 	 */
3400 	for (; adp; adp = listadp) {
3401 		listadp = TAILQ_NEXT(adp, ad_next);
3402 		if ((adp->ad_state & ALLCOMPLETE) != ALLCOMPLETE)
3403 			return;
3404 		free_allocdirect(&inodedep->id_inoupdt, adp, 1);
3405 	}
3406 }
3407 
3408 /*
3409  * Called from within softdep_disk_write_complete above. Note that
3410  * this routine is always called from interrupt level with further
3411  * splbio interrupts blocked.
3412  */
3413 static void
3414 handle_allocindir_partdone(aip)
3415 	struct allocindir *aip;		/* the completed allocindir */
3416 {
3417 	struct indirdep *indirdep;
3418 
3419 	if ((aip->ai_state & ALLCOMPLETE) != ALLCOMPLETE)
3420 		return;
3421 	if (aip->ai_buf != NULL) {
3422 		lk.lkt_held = NOHOLDER;
3423 		panic("handle_allocindir_partdone: dangling dependency");
3424 	}
3425 	indirdep = aip->ai_indirdep;
3426 	if (indirdep->ir_state & UNDONE) {
3427 		LIST_REMOVE(aip, ai_next);
3428 		LIST_INSERT_HEAD(&indirdep->ir_donehd, aip, ai_next);
3429 		return;
3430 	}
3431 	((ufs_daddr_t *)indirdep->ir_savebp->b_data)[aip->ai_offset] =
3432 	    aip->ai_newblkno;
3433 	LIST_REMOVE(aip, ai_next);
3434 	if (aip->ai_freefrag != NULL)
3435 		add_to_worklist(&aip->ai_freefrag->ff_list);
3436 	WORKITEM_FREE(aip, D_ALLOCINDIR);
3437 }
3438 
3439 /*
3440  * Called from within softdep_disk_write_complete above to restore
3441  * in-memory inode block contents to their most up-to-date state. Note
3442  * that this routine is always called from interrupt level with further
3443  * splbio interrupts blocked.
3444  */
3445 static int
3446 handle_written_inodeblock(inodedep, bp)
3447 	struct inodedep *inodedep;
3448 	struct buf *bp;		/* buffer containing the inode block */
3449 {
3450 	struct worklist *wk, *filefree;
3451 	struct allocdirect *adp, *nextadp;
3452 	struct dinode *dp;
3453 	int hadchanges;
3454 
3455 	if ((inodedep->id_state & IOSTARTED) == 0) {
3456 		lk.lkt_held = NOHOLDER;
3457 		panic("handle_written_inodeblock: not started");
3458 	}
3459 	inodedep->id_state &= ~IOSTARTED;
3460 	inodedep->id_state |= COMPLETE;
3461 	dp = (struct dinode *)bp->b_data +
3462 	    ino_to_fsbo(inodedep->id_fs, inodedep->id_ino);
3463 	/*
3464 	 * If we had to rollback the inode allocation because of
3465 	 * bitmaps being incomplete, then simply restore it.
3466 	 * Keep the block dirty so that it will not be reclaimed until
3467 	 * all associated dependencies have been cleared and the
3468 	 * corresponding updates written to disk.
3469 	 */
3470 	if (inodedep->id_savedino != NULL) {
3471 		*dp = *inodedep->id_savedino;
3472 		FREE(inodedep->id_savedino, M_INODEDEP);
3473 		inodedep->id_savedino = NULL;
3474 		if ((bp->b_flags & B_DELWRI) == 0)
3475 			stat_inode_bitmap++;
3476 		bdirty(bp);
3477 		return (1);
3478 	}
3479 	/*
3480 	 * Roll forward anything that had to be rolled back before
3481 	 * the inode could be updated.
3482 	 */
3483 	hadchanges = 0;
3484 	for (adp = TAILQ_FIRST(&inodedep->id_inoupdt); adp; adp = nextadp) {
3485 		nextadp = TAILQ_NEXT(adp, ad_next);
3486 		if (adp->ad_state & ATTACHED) {
3487 			lk.lkt_held = NOHOLDER;
3488 			panic("handle_written_inodeblock: new entry");
3489 		}
3490 		if (adp->ad_lbn < NDADDR) {
3491 			if (dp->di_db[adp->ad_lbn] != adp->ad_oldblkno) {
3492 				lk.lkt_held = NOHOLDER;
3493 				panic("%s: %s #%ld mismatch %d != %d",
3494 				    "handle_written_inodeblock",
3495 				    "direct pointer", adp->ad_lbn,
3496 				    dp->di_db[adp->ad_lbn], adp->ad_oldblkno);
3497 			}
3498 			dp->di_db[adp->ad_lbn] = adp->ad_newblkno;
3499 		} else {
3500 			if (dp->di_ib[adp->ad_lbn - NDADDR] != 0) {
3501 				lk.lkt_held = NOHOLDER;
3502 				panic("%s: %s #%ld allocated as %d",
3503 				    "handle_written_inodeblock",
3504 				    "indirect pointer", adp->ad_lbn - NDADDR,
3505 				    dp->di_ib[adp->ad_lbn - NDADDR]);
3506 			}
3507 			dp->di_ib[adp->ad_lbn - NDADDR] = adp->ad_newblkno;
3508 		}
3509 		adp->ad_state &= ~UNDONE;
3510 		adp->ad_state |= ATTACHED;
3511 		hadchanges = 1;
3512 	}
3513 	if (hadchanges && (bp->b_flags & B_DELWRI) == 0)
3514 		stat_direct_blk_ptrs++;
3515 	/*
3516 	 * Reset the file size to its most up-to-date value.
3517 	 */
3518 	if (inodedep->id_savedsize == -1) {
3519 		lk.lkt_held = NOHOLDER;
3520 		panic("handle_written_inodeblock: bad size");
3521 	}
3522 	if (dp->di_size != inodedep->id_savedsize) {
3523 		dp->di_size = inodedep->id_savedsize;
3524 		hadchanges = 1;
3525 	}
3526 	inodedep->id_savedsize = -1;
3527 	/*
3528 	 * If there were any rollbacks in the inode block, then it must be
3529 	 * marked dirty so that its will eventually get written back in
3530 	 * its correct form.
3531 	 */
3532 	if (hadchanges)
3533 		bdirty(bp);
3534 	/*
3535 	 * Process any allocdirects that completed during the update.
3536 	 */
3537 	if ((adp = TAILQ_FIRST(&inodedep->id_inoupdt)) != NULL)
3538 		handle_allocdirect_partdone(adp);
3539 	/*
3540 	 * Process deallocations that were held pending until the
3541 	 * inode had been written to disk. Freeing of the inode
3542 	 * is delayed until after all blocks have been freed to
3543 	 * avoid creation of new <vfsid, inum, lbn> triples
3544 	 * before the old ones have been deleted.
3545 	 */
3546 	filefree = NULL;
3547 	while ((wk = LIST_FIRST(&inodedep->id_bufwait)) != NULL) {
3548 		WORKLIST_REMOVE(wk);
3549 		switch (wk->wk_type) {
3550 
3551 		case D_FREEFILE:
3552 			/*
3553 			 * We defer adding filefree to the worklist until
3554 			 * all other additions have been made to ensure
3555 			 * that it will be done after all the old blocks
3556 			 * have been freed.
3557 			 */
3558 			if (filefree != NULL) {
3559 				lk.lkt_held = NOHOLDER;
3560 				panic("handle_written_inodeblock: filefree");
3561 			}
3562 			filefree = wk;
3563 			continue;
3564 
3565 		case D_MKDIR:
3566 			handle_written_mkdir(WK_MKDIR(wk), MKDIR_PARENT);
3567 			continue;
3568 
3569 		case D_DIRADD:
3570 			diradd_inode_written(WK_DIRADD(wk), inodedep);
3571 			continue;
3572 
3573 		case D_FREEBLKS:
3574 		case D_FREEFRAG:
3575 		case D_DIRREM:
3576 			add_to_worklist(wk);
3577 			continue;
3578 
3579 		default:
3580 			lk.lkt_held = NOHOLDER;
3581 			panic("handle_written_inodeblock: Unknown type %s",
3582 			    TYPENAME(wk->wk_type));
3583 			/* NOTREACHED */
3584 		}
3585 	}
3586 	if (filefree != NULL) {
3587 		if (free_inodedep(inodedep) == 0) {
3588 			lk.lkt_held = NOHOLDER;
3589 			panic("handle_written_inodeblock: live inodedep");
3590 		}
3591 		add_to_worklist(filefree);
3592 		return (0);
3593 	}
3594 
3595 	/*
3596 	 * If no outstanding dependencies, free it.
3597 	 */
3598 	if (free_inodedep(inodedep) || TAILQ_FIRST(&inodedep->id_inoupdt) == 0)
3599 		return (0);
3600 	return (hadchanges);
3601 }
3602 
3603 /*
3604  * Process a diradd entry after its dependent inode has been written.
3605  * This routine must be called with splbio interrupts blocked.
3606  */
3607 static void
3608 diradd_inode_written(dap, inodedep)
3609 	struct diradd *dap;
3610 	struct inodedep *inodedep;
3611 {
3612 	struct pagedep *pagedep;
3613 
3614 	dap->da_state |= COMPLETE;
3615 	if ((dap->da_state & ALLCOMPLETE) == ALLCOMPLETE) {
3616 		if (dap->da_state & DIRCHG)
3617 			pagedep = dap->da_previous->dm_pagedep;
3618 		else
3619 			pagedep = dap->da_pagedep;
3620 		LIST_REMOVE(dap, da_pdlist);
3621 		LIST_INSERT_HEAD(&pagedep->pd_pendinghd, dap, da_pdlist);
3622 	}
3623 	WORKLIST_INSERT(&inodedep->id_pendinghd, &dap->da_list);
3624 }
3625 
3626 /*
3627  * Handle the completion of a mkdir dependency.
3628  */
3629 static void
3630 handle_written_mkdir(mkdir, type)
3631 	struct mkdir *mkdir;
3632 	int type;
3633 {
3634 	struct diradd *dap;
3635 	struct pagedep *pagedep;
3636 
3637 	if (mkdir->md_state != type) {
3638 		lk.lkt_held = NOHOLDER;
3639 		panic("handle_written_mkdir: bad type");
3640 	}
3641 	dap = mkdir->md_diradd;
3642 	dap->da_state &= ~type;
3643 	if ((dap->da_state & (MKDIR_PARENT | MKDIR_BODY)) == 0)
3644 		dap->da_state |= DEPCOMPLETE;
3645 	if ((dap->da_state & ALLCOMPLETE) == ALLCOMPLETE) {
3646 		if (dap->da_state & DIRCHG)
3647 			pagedep = dap->da_previous->dm_pagedep;
3648 		else
3649 			pagedep = dap->da_pagedep;
3650 		LIST_REMOVE(dap, da_pdlist);
3651 		LIST_INSERT_HEAD(&pagedep->pd_pendinghd, dap, da_pdlist);
3652 	}
3653 	LIST_REMOVE(mkdir, md_mkdirs);
3654 	WORKITEM_FREE(mkdir, D_MKDIR);
3655 }
3656 
3657 /*
3658  * Called from within softdep_disk_write_complete above.
3659  * A write operation was just completed. Removed inodes can
3660  * now be freed and associated block pointers may be committed.
3661  * Note that this routine is always called from interrupt level
3662  * with further splbio interrupts blocked.
3663  */
3664 static int
3665 handle_written_filepage(pagedep, bp)
3666 	struct pagedep *pagedep;
3667 	struct buf *bp;		/* buffer containing the written page */
3668 {
3669 	struct dirrem *dirrem;
3670 	struct diradd *dap, *nextdap;
3671 	struct direct *ep;
3672 	int i, chgs;
3673 
3674 	if ((pagedep->pd_state & IOSTARTED) == 0) {
3675 		lk.lkt_held = NOHOLDER;
3676 		panic("handle_written_filepage: not started");
3677 	}
3678 	pagedep->pd_state &= ~IOSTARTED;
3679 	/*
3680 	 * Process any directory removals that have been committed.
3681 	 */
3682 	while ((dirrem = LIST_FIRST(&pagedep->pd_dirremhd)) != NULL) {
3683 		LIST_REMOVE(dirrem, dm_next);
3684 		dirrem->dm_dirinum = pagedep->pd_ino;
3685 		add_to_worklist(&dirrem->dm_list);
3686 	}
3687 	/*
3688 	 * Free any directory additions that have been committed.
3689 	 */
3690 	while ((dap = LIST_FIRST(&pagedep->pd_pendinghd)) != NULL)
3691 		free_diradd(dap);
3692 	/*
3693 	 * Uncommitted directory entries must be restored.
3694 	 */
3695 	for (chgs = 0, i = 0; i < DAHASHSZ; i++) {
3696 		for (dap = LIST_FIRST(&pagedep->pd_diraddhd[i]); dap;
3697 		     dap = nextdap) {
3698 			nextdap = LIST_NEXT(dap, da_pdlist);
3699 			if (dap->da_state & ATTACHED) {
3700 				lk.lkt_held = NOHOLDER;
3701 				panic("handle_written_filepage: attached");
3702 			}
3703 			ep = (struct direct *)
3704 			    ((char *)bp->b_data + dap->da_offset);
3705 			ep->d_ino = dap->da_newinum;
3706 			dap->da_state &= ~UNDONE;
3707 			dap->da_state |= ATTACHED;
3708 			chgs = 1;
3709 			/*
3710 			 * If the inode referenced by the directory has
3711 			 * been written out, then the dependency can be
3712 			 * moved to the pending list.
3713 			 */
3714 			if ((dap->da_state & ALLCOMPLETE) == ALLCOMPLETE) {
3715 				LIST_REMOVE(dap, da_pdlist);
3716 				LIST_INSERT_HEAD(&pagedep->pd_pendinghd, dap,
3717 				    da_pdlist);
3718 			}
3719 		}
3720 	}
3721 	/*
3722 	 * If there were any rollbacks in the directory, then it must be
3723 	 * marked dirty so that its will eventually get written back in
3724 	 * its correct form.
3725 	 */
3726 	if (chgs) {
3727 		if ((bp->b_flags & B_DELWRI) == 0)
3728 			stat_dir_entry++;
3729 		bdirty(bp);
3730 	}
3731 	/*
3732 	 * If no dependencies remain, the pagedep will be freed.
3733 	 * Otherwise it will remain to update the page before it
3734 	 * is written back to disk.
3735 	 */
3736 	if (LIST_FIRST(&pagedep->pd_pendinghd) == 0) {
3737 		for (i = 0; i < DAHASHSZ; i++)
3738 			if (LIST_FIRST(&pagedep->pd_diraddhd[i]) != NULL)
3739 				break;
3740 		if (i == DAHASHSZ) {
3741 			LIST_REMOVE(pagedep, pd_hash);
3742 			WORKITEM_FREE(pagedep, D_PAGEDEP);
3743 			return (0);
3744 		}
3745 	}
3746 	return (1);
3747 }
3748 
3749 /*
3750  * Writing back in-core inode structures.
3751  *
3752  * The file system only accesses an inode's contents when it occupies an
3753  * "in-core" inode structure.  These "in-core" structures are separate from
3754  * the page frames used to cache inode blocks.  Only the latter are
3755  * transferred to/from the disk.  So, when the updated contents of the
3756  * "in-core" inode structure are copied to the corresponding in-memory inode
3757  * block, the dependencies are also transferred.  The following procedure is
3758  * called when copying a dirty "in-core" inode to a cached inode block.
3759  */
3760 
3761 /*
3762  * Called when an inode is loaded from disk. If the effective link count
3763  * differed from the actual link count when it was last flushed, then we
3764  * need to ensure that the correct effective link count is put back.
3765  */
3766 void
3767 softdep_load_inodeblock(ip)
3768 	struct inode *ip;	/* the "in_core" copy of the inode */
3769 {
3770 	struct inodedep *inodedep;
3771 
3772 	/*
3773 	 * Check for alternate nlink count.
3774 	 */
3775 	ip->i_effnlink = ip->i_nlink;
3776 	ACQUIRE_LOCK(&lk);
3777 	if (inodedep_lookup(ip->i_fs, ip->i_number, 0, &inodedep) == 0) {
3778 		FREE_LOCK(&lk);
3779 		return;
3780 	}
3781 	ip->i_effnlink -= inodedep->id_nlinkdelta;
3782 	FREE_LOCK(&lk);
3783 }
3784 
3785 /*
3786  * This routine is called just before the "in-core" inode
3787  * information is to be copied to the in-memory inode block.
3788  * Recall that an inode block contains several inodes. If
3789  * the force flag is set, then the dependencies will be
3790  * cleared so that the update can always be made. Note that
3791  * the buffer is locked when this routine is called, so we
3792  * will never be in the middle of writing the inode block
3793  * to disk.
3794  */
3795 void
3796 softdep_update_inodeblock(ip, bp, waitfor)
3797 	struct inode *ip;	/* the "in_core" copy of the inode */
3798 	struct buf *bp;		/* the buffer containing the inode block */
3799 	int waitfor;		/* nonzero => update must be allowed */
3800 {
3801 	struct inodedep *inodedep;
3802 	struct worklist *wk;
3803 	int error, gotit;
3804 
3805 	/*
3806 	 * If the effective link count is not equal to the actual link
3807 	 * count, then we must track the difference in an inodedep while
3808 	 * the inode is (potentially) tossed out of the cache. Otherwise,
3809 	 * if there is no existing inodedep, then there are no dependencies
3810 	 * to track.
3811 	 */
3812 	ACQUIRE_LOCK(&lk);
3813 	if (inodedep_lookup(ip->i_fs, ip->i_number, 0, &inodedep) == 0) {
3814 		FREE_LOCK(&lk);
3815 		if (ip->i_effnlink != ip->i_nlink)
3816 			panic("softdep_update_inodeblock: bad link count");
3817 		return;
3818 	}
3819 	if (inodedep->id_nlinkdelta != ip->i_nlink - ip->i_effnlink) {
3820 		FREE_LOCK(&lk);
3821 		panic("softdep_update_inodeblock: bad delta");
3822 	}
3823 	/*
3824 	 * Changes have been initiated. Anything depending on these
3825 	 * changes cannot occur until this inode has been written.
3826 	 */
3827 	inodedep->id_state &= ~COMPLETE;
3828 	if ((inodedep->id_state & ONWORKLIST) == 0)
3829 		WORKLIST_INSERT(&bp->b_dep, &inodedep->id_list);
3830 	/*
3831 	 * Any new dependencies associated with the incore inode must
3832 	 * now be moved to the list associated with the buffer holding
3833 	 * the in-memory copy of the inode. Once merged process any
3834 	 * allocdirects that are completed by the merger.
3835 	 */
3836 	merge_inode_lists(inodedep);
3837 	if (TAILQ_FIRST(&inodedep->id_inoupdt) != NULL)
3838 		handle_allocdirect_partdone(TAILQ_FIRST(&inodedep->id_inoupdt));
3839 	/*
3840 	 * Now that the inode has been pushed into the buffer, the
3841 	 * operations dependent on the inode being written to disk
3842 	 * can be moved to the id_bufwait so that they will be
3843 	 * processed when the buffer I/O completes.
3844 	 */
3845 	while ((wk = LIST_FIRST(&inodedep->id_inowait)) != NULL) {
3846 		WORKLIST_REMOVE(wk);
3847 		WORKLIST_INSERT(&inodedep->id_bufwait, wk);
3848 	}
3849 	/*
3850 	 * Newly allocated inodes cannot be written until the bitmap
3851 	 * that allocates them have been written (indicated by
3852 	 * DEPCOMPLETE being set in id_state). If we are doing a
3853 	 * forced sync (e.g., an fsync on a file), we force the bitmap
3854 	 * to be written so that the update can be done.
3855 	 */
3856 	if ((inodedep->id_state & DEPCOMPLETE) != 0 || waitfor == 0) {
3857 		FREE_LOCK(&lk);
3858 		return;
3859 	}
3860 	gotit = getdirtybuf(&inodedep->id_buf, MNT_WAIT);
3861 	FREE_LOCK(&lk);
3862 	if (gotit &&
3863 	    (error = VOP_BWRITE(inodedep->id_buf->b_vp, inodedep->id_buf)) != 0)
3864 		softdep_error("softdep_update_inodeblock: bwrite", error);
3865 	if ((inodedep->id_state & DEPCOMPLETE) == 0)
3866 		panic("softdep_update_inodeblock: update failed");
3867 }
3868 
3869 /*
3870  * Merge the new inode dependency list (id_newinoupdt) into the old
3871  * inode dependency list (id_inoupdt). This routine must be called
3872  * with splbio interrupts blocked.
3873  */
3874 static void
3875 merge_inode_lists(inodedep)
3876 	struct inodedep *inodedep;
3877 {
3878 	struct allocdirect *listadp, *newadp;
3879 
3880 	newadp = TAILQ_FIRST(&inodedep->id_newinoupdt);
3881 	for (listadp = TAILQ_FIRST(&inodedep->id_inoupdt); listadp && newadp;) {
3882 		if (listadp->ad_lbn < newadp->ad_lbn) {
3883 			listadp = TAILQ_NEXT(listadp, ad_next);
3884 			continue;
3885 		}
3886 		TAILQ_REMOVE(&inodedep->id_newinoupdt, newadp, ad_next);
3887 		TAILQ_INSERT_BEFORE(listadp, newadp, ad_next);
3888 		if (listadp->ad_lbn == newadp->ad_lbn) {
3889 			allocdirect_merge(&inodedep->id_inoupdt, newadp,
3890 			    listadp);
3891 			listadp = newadp;
3892 		}
3893 		newadp = TAILQ_FIRST(&inodedep->id_newinoupdt);
3894 	}
3895 	while ((newadp = TAILQ_FIRST(&inodedep->id_newinoupdt)) != NULL) {
3896 		TAILQ_REMOVE(&inodedep->id_newinoupdt, newadp, ad_next);
3897 		TAILQ_INSERT_TAIL(&inodedep->id_inoupdt, newadp, ad_next);
3898 	}
3899 }
3900 
3901 /*
3902  * If we are doing an fsync, then we must ensure that any directory
3903  * entries for the inode have been written after the inode gets to disk.
3904  */
3905 static int
3906 softdep_fsync(vp)
3907 	struct vnode *vp;	/* the "in_core" copy of the inode */
3908 {
3909 	struct inodedep *inodedep;
3910 	struct pagedep *pagedep;
3911 	struct worklist *wk;
3912 	struct diradd *dap;
3913 	struct mount *mnt;
3914 	struct vnode *pvp;
3915 	struct inode *ip;
3916 	struct buf *bp;
3917 	struct fs *fs;
3918 	struct thread *td = curthread;		/* XXX */
3919 	int error, flushparent;
3920 	ino_t parentino;
3921 	ufs_lbn_t lbn;
3922 
3923 	ip = VTOI(vp);
3924 	fs = ip->i_fs;
3925 	ACQUIRE_LOCK(&lk);
3926 	if (inodedep_lookup(fs, ip->i_number, 0, &inodedep) == 0) {
3927 		FREE_LOCK(&lk);
3928 		return (0);
3929 	}
3930 	if (LIST_FIRST(&inodedep->id_inowait) != NULL ||
3931 	    LIST_FIRST(&inodedep->id_bufwait) != NULL ||
3932 	    TAILQ_FIRST(&inodedep->id_inoupdt) != NULL ||
3933 	    TAILQ_FIRST(&inodedep->id_newinoupdt) != NULL) {
3934 		FREE_LOCK(&lk);
3935 		panic("softdep_fsync: pending ops");
3936 	}
3937 	for (error = 0, flushparent = 0; ; ) {
3938 		if ((wk = LIST_FIRST(&inodedep->id_pendinghd)) == NULL)
3939 			break;
3940 		if (wk->wk_type != D_DIRADD) {
3941 			FREE_LOCK(&lk);
3942 			panic("softdep_fsync: Unexpected type %s",
3943 			    TYPENAME(wk->wk_type));
3944 		}
3945 		dap = WK_DIRADD(wk);
3946 		/*
3947 		 * Flush our parent if this directory entry
3948 		 * has a MKDIR_PARENT dependency.
3949 		 */
3950 		if (dap->da_state & DIRCHG)
3951 			pagedep = dap->da_previous->dm_pagedep;
3952 		else
3953 			pagedep = dap->da_pagedep;
3954 		mnt = pagedep->pd_mnt;
3955 		parentino = pagedep->pd_ino;
3956 		lbn = pagedep->pd_lbn;
3957 		if ((dap->da_state & (MKDIR_BODY | COMPLETE)) != COMPLETE) {
3958 			FREE_LOCK(&lk);
3959 			panic("softdep_fsync: dirty");
3960 		}
3961 		flushparent = dap->da_state & MKDIR_PARENT;
3962 		/*
3963 		 * If we are being fsync'ed as part of vgone'ing this vnode,
3964 		 * then we will not be able to release and recover the
3965 		 * vnode below, so we just have to give up on writing its
3966 		 * directory entry out. It will eventually be written, just
3967 		 * not now, but then the user was not asking to have it
3968 		 * written, so we are not breaking any promises.
3969 		 */
3970 		if (vp->v_flag & VXLOCK)
3971 			break;
3972 		/*
3973 		 * We prevent deadlock by always fetching inodes from the
3974 		 * root, moving down the directory tree. Thus, when fetching
3975 		 * our parent directory, we must unlock ourselves before
3976 		 * requesting the lock on our parent. See the comment in
3977 		 * ufs_lookup for details on possible races.
3978 		 */
3979 		FREE_LOCK(&lk);
3980 		VOP_UNLOCK(vp, 0, td);
3981 		error = VFS_VGET(mnt, parentino, &pvp);
3982 		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
3983 		if (error != 0)
3984 			return (error);
3985 		if (flushparent) {
3986 			if ((error = UFS_UPDATE(pvp, 1)) != 0) {
3987 				vput(pvp);
3988 				return (error);
3989 			}
3990 		}
3991 		/*
3992 		 * Flush directory page containing the inode's name.
3993 		 */
3994 		error = bread(pvp, lbn, blksize(fs, VTOI(pvp), lbn), &bp);
3995 		if (error == 0)
3996 			error = VOP_BWRITE(bp->b_vp, bp);
3997 		vput(pvp);
3998 		if (error != 0)
3999 			return (error);
4000 		ACQUIRE_LOCK(&lk);
4001 		if (inodedep_lookup(fs, ip->i_number, 0, &inodedep) == 0)
4002 			break;
4003 	}
4004 	FREE_LOCK(&lk);
4005 	return (0);
4006 }
4007 
4008 /*
4009  * Flush all the dirty bitmaps associated with the block device
4010  * before flushing the rest of the dirty blocks so as to reduce
4011  * the number of dependencies that will have to be rolled back.
4012  */
4013 void
4014 softdep_fsync_mountdev(vp)
4015 	struct vnode *vp;
4016 {
4017 	struct buf *bp, *nbp;
4018 	struct worklist *wk;
4019 
4020 	if (!vn_isdisk(vp, NULL))
4021 		panic("softdep_fsync_mountdev: vnode not a disk");
4022 	ACQUIRE_LOCK(&lk);
4023 	for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) {
4024 		nbp = TAILQ_NEXT(bp, b_vnbufs);
4025 		/*
4026 		 * If it is already scheduled, skip to the next buffer.
4027 		 */
4028 		if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT))
4029 			continue;
4030 		if ((bp->b_flags & B_DELWRI) == 0) {
4031 			FREE_LOCK(&lk);
4032 			panic("softdep_fsync_mountdev: not dirty");
4033 		}
4034 		/*
4035 		 * We are only interested in bitmaps with outstanding
4036 		 * dependencies.
4037 		 */
4038 		if ((wk = LIST_FIRST(&bp->b_dep)) == NULL ||
4039 		    wk->wk_type != D_BMSAFEMAP ||
4040 		    (bp->b_xflags & BX_BKGRDINPROG)) {
4041 			BUF_UNLOCK(bp);
4042 			continue;
4043 		}
4044 		bremfree(bp);
4045 		FREE_LOCK(&lk);
4046 		(void) bawrite(bp);
4047 		ACQUIRE_LOCK(&lk);
4048 		/*
4049 		 * Since we may have slept during the I/O, we need
4050 		 * to start from a known point.
4051 		 */
4052 		nbp = TAILQ_FIRST(&vp->v_dirtyblkhd);
4053 	}
4054 	drain_output(vp, 1);
4055 	FREE_LOCK(&lk);
4056 }
4057 
4058 /*
4059  * This routine is called when we are trying to synchronously flush a
4060  * file. This routine must eliminate any filesystem metadata dependencies
4061  * so that the syncing routine can succeed by pushing the dirty blocks
4062  * associated with the file. If any I/O errors occur, they are returned.
4063  */
4064 int
4065 softdep_sync_metadata(ap)
4066 	struct vop_fsync_args /* {
4067 		struct vnode *a_vp;
4068 		struct ucred *a_cred;
4069 		int a_waitfor;
4070 		struct proc *a_p;
4071 	} */ *ap;
4072 {
4073 	struct vnode *vp = ap->a_vp;
4074 	struct pagedep *pagedep;
4075 	struct allocdirect *adp;
4076 	struct allocindir *aip;
4077 	struct buf *bp, *nbp;
4078 	struct worklist *wk;
4079 	int i, error, waitfor;
4080 
4081 	/*
4082 	 * Check whether this vnode is involved in a filesystem
4083 	 * that is doing soft dependency processing.
4084 	 */
4085 	if (!vn_isdisk(vp, NULL)) {
4086 		if (!DOINGSOFTDEP(vp))
4087 			return (0);
4088 	} else
4089 		if (vp->v_specmountpoint == NULL ||
4090 		    (vp->v_specmountpoint->mnt_flag & MNT_SOFTDEP) == 0)
4091 			return (0);
4092 	/*
4093 	 * Ensure that any direct block dependencies have been cleared.
4094 	 */
4095 	ACQUIRE_LOCK(&lk);
4096 	if ((error = flush_inodedep_deps(VTOI(vp)->i_fs, VTOI(vp)->i_number))) {
4097 		FREE_LOCK(&lk);
4098 		return (error);
4099 	}
4100 	/*
4101 	 * For most files, the only metadata dependencies are the
4102 	 * cylinder group maps that allocate their inode or blocks.
4103 	 * The block allocation dependencies can be found by traversing
4104 	 * the dependency lists for any buffers that remain on their
4105 	 * dirty buffer list. The inode allocation dependency will
4106 	 * be resolved when the inode is updated with MNT_WAIT.
4107 	 * This work is done in two passes. The first pass grabs most
4108 	 * of the buffers and begins asynchronously writing them. The
4109 	 * only way to wait for these asynchronous writes is to sleep
4110 	 * on the filesystem vnode which may stay busy for a long time
4111 	 * if the filesystem is active. So, instead, we make a second
4112 	 * pass over the dependencies blocking on each write. In the
4113 	 * usual case we will be blocking against a write that we
4114 	 * initiated, so when it is done the dependency will have been
4115 	 * resolved. Thus the second pass is expected to end quickly.
4116 	 */
4117 	waitfor = MNT_NOWAIT;
4118 top:
4119 	/*
4120 	 * We must wait for any I/O in progress to finish so that
4121 	 * all potential buffers on the dirty list will be visible.
4122 	 */
4123 	drain_output(vp, 1);
4124 	if (getdirtybuf(&TAILQ_FIRST(&vp->v_dirtyblkhd), MNT_WAIT) == 0) {
4125 		FREE_LOCK(&lk);
4126 		return (0);
4127 	}
4128 	bp = TAILQ_FIRST(&vp->v_dirtyblkhd);
4129 loop:
4130 	/*
4131 	 * As we hold the buffer locked, none of its dependencies
4132 	 * will disappear.
4133 	 */
4134 	LIST_FOREACH(wk, &bp->b_dep, wk_list) {
4135 		switch (wk->wk_type) {
4136 
4137 		case D_ALLOCDIRECT:
4138 			adp = WK_ALLOCDIRECT(wk);
4139 			if (adp->ad_state & DEPCOMPLETE)
4140 				break;
4141 			nbp = adp->ad_buf;
4142 			if (getdirtybuf(&nbp, waitfor) == 0)
4143 				break;
4144 			FREE_LOCK(&lk);
4145 			if (waitfor == MNT_NOWAIT) {
4146 				bawrite(nbp);
4147 			} else if ((error = VOP_BWRITE(nbp->b_vp, nbp)) != 0) {
4148 				bawrite(bp);
4149 				return (error);
4150 			}
4151 			ACQUIRE_LOCK(&lk);
4152 			break;
4153 
4154 		case D_ALLOCINDIR:
4155 			aip = WK_ALLOCINDIR(wk);
4156 			if (aip->ai_state & DEPCOMPLETE)
4157 				break;
4158 			nbp = aip->ai_buf;
4159 			if (getdirtybuf(&nbp, waitfor) == 0)
4160 				break;
4161 			FREE_LOCK(&lk);
4162 			if (waitfor == MNT_NOWAIT) {
4163 				bawrite(nbp);
4164 			} else if ((error = VOP_BWRITE(nbp->b_vp, nbp)) != 0) {
4165 				bawrite(bp);
4166 				return (error);
4167 			}
4168 			ACQUIRE_LOCK(&lk);
4169 			break;
4170 
4171 		case D_INDIRDEP:
4172 		restart:
4173 
4174 			LIST_FOREACH(aip, &WK_INDIRDEP(wk)->ir_deplisthd, ai_next) {
4175 				if (aip->ai_state & DEPCOMPLETE)
4176 					continue;
4177 				nbp = aip->ai_buf;
4178 				if (getdirtybuf(&nbp, MNT_WAIT) == 0)
4179 					goto restart;
4180 				FREE_LOCK(&lk);
4181 				if ((error = VOP_BWRITE(nbp->b_vp, nbp)) != 0) {
4182 					bawrite(bp);
4183 					return (error);
4184 				}
4185 				ACQUIRE_LOCK(&lk);
4186 				goto restart;
4187 			}
4188 			break;
4189 
4190 		case D_INODEDEP:
4191 			if ((error = flush_inodedep_deps(WK_INODEDEP(wk)->id_fs,
4192 			    WK_INODEDEP(wk)->id_ino)) != 0) {
4193 				FREE_LOCK(&lk);
4194 				bawrite(bp);
4195 				return (error);
4196 			}
4197 			break;
4198 
4199 		case D_PAGEDEP:
4200 			/*
4201 			 * We are trying to sync a directory that may
4202 			 * have dependencies on both its own metadata
4203 			 * and/or dependencies on the inodes of any
4204 			 * recently allocated files. We walk its diradd
4205 			 * lists pushing out the associated inode.
4206 			 */
4207 			pagedep = WK_PAGEDEP(wk);
4208 			for (i = 0; i < DAHASHSZ; i++) {
4209 				if (LIST_FIRST(&pagedep->pd_diraddhd[i]) == 0)
4210 					continue;
4211 				if ((error =
4212 				    flush_pagedep_deps(vp, pagedep->pd_mnt,
4213 						&pagedep->pd_diraddhd[i]))) {
4214 					FREE_LOCK(&lk);
4215 					bawrite(bp);
4216 					return (error);
4217 				}
4218 			}
4219 			break;
4220 
4221 		case D_MKDIR:
4222 			/*
4223 			 * This case should never happen if the vnode has
4224 			 * been properly sync'ed. However, if this function
4225 			 * is used at a place where the vnode has not yet
4226 			 * been sync'ed, this dependency can show up. So,
4227 			 * rather than panic, just flush it.
4228 			 */
4229 			nbp = WK_MKDIR(wk)->md_buf;
4230 			if (getdirtybuf(&nbp, waitfor) == 0)
4231 				break;
4232 			FREE_LOCK(&lk);
4233 			if (waitfor == MNT_NOWAIT) {
4234 				bawrite(nbp);
4235 			} else if ((error = VOP_BWRITE(nbp->b_vp, nbp)) != 0) {
4236 				bawrite(bp);
4237 				return (error);
4238 			}
4239 			ACQUIRE_LOCK(&lk);
4240 			break;
4241 
4242 		case D_BMSAFEMAP:
4243 			/*
4244 			 * This case should never happen if the vnode has
4245 			 * been properly sync'ed. However, if this function
4246 			 * is used at a place where the vnode has not yet
4247 			 * been sync'ed, this dependency can show up. So,
4248 			 * rather than panic, just flush it.
4249 			 */
4250 			nbp = WK_BMSAFEMAP(wk)->sm_buf;
4251 			if (getdirtybuf(&nbp, waitfor) == 0)
4252 				break;
4253 			FREE_LOCK(&lk);
4254 			if (waitfor == MNT_NOWAIT) {
4255 				bawrite(nbp);
4256 			} else if ((error = VOP_BWRITE(nbp->b_vp, nbp)) != 0) {
4257 				bawrite(bp);
4258 				return (error);
4259 			}
4260 			ACQUIRE_LOCK(&lk);
4261 			break;
4262 
4263 		default:
4264 			FREE_LOCK(&lk);
4265 			panic("softdep_sync_metadata: Unknown type %s",
4266 			    TYPENAME(wk->wk_type));
4267 			/* NOTREACHED */
4268 		}
4269 	}
4270 	(void) getdirtybuf(&TAILQ_NEXT(bp, b_vnbufs), MNT_WAIT);
4271 	nbp = TAILQ_NEXT(bp, b_vnbufs);
4272 	FREE_LOCK(&lk);
4273 	bawrite(bp);
4274 	ACQUIRE_LOCK(&lk);
4275 	if (nbp != NULL) {
4276 		bp = nbp;
4277 		goto loop;
4278 	}
4279 	/*
4280 	 * The brief unlock is to allow any pent up dependency
4281 	 * processing to be done.  Then proceed with the second pass.
4282 	 */
4283 	if (waitfor == MNT_NOWAIT) {
4284 		waitfor = MNT_WAIT;
4285 		FREE_LOCK(&lk);
4286 		ACQUIRE_LOCK(&lk);
4287 		goto top;
4288 	}
4289 
4290 	/*
4291 	 * If we have managed to get rid of all the dirty buffers,
4292 	 * then we are done. For certain directories and block
4293 	 * devices, we may need to do further work.
4294 	 */
4295 	if (TAILQ_FIRST(&vp->v_dirtyblkhd) == NULL) {
4296 		FREE_LOCK(&lk);
4297 		return (0);
4298 	}
4299 
4300 	FREE_LOCK(&lk);
4301 	/*
4302 	 * If we are trying to sync a block device, some of its buffers may
4303 	 * contain metadata that cannot be written until the contents of some
4304 	 * partially written files have been written to disk. The only easy
4305 	 * way to accomplish this is to sync the entire filesystem (luckily
4306 	 * this happens rarely).
4307 	 *
4308 	 * We must wait for any I/O in progress to finish so that
4309 	 * all potential buffers on the dirty list will be visible.
4310 	 */
4311 	drain_output(vp, 1);
4312 	if (vn_isdisk(vp, NULL) &&
4313 	    vp->v_specmountpoint && !VOP_ISLOCKED(vp, NULL) &&
4314 	    (error = VFS_SYNC(vp->v_specmountpoint, MNT_WAIT, ap->a_td)) != 0)
4315 		return (error);
4316 	return (0);
4317 }
4318 
4319 /*
4320  * Flush the dependencies associated with an inodedep.
4321  * Called with splbio blocked.
4322  */
4323 static int
4324 flush_inodedep_deps(fs, ino)
4325 	struct fs *fs;
4326 	ino_t ino;
4327 {
4328 	struct inodedep *inodedep;
4329 	struct allocdirect *adp;
4330 	int error, waitfor;
4331 	struct buf *bp;
4332 
4333 	/*
4334 	 * This work is done in two passes. The first pass grabs most
4335 	 * of the buffers and begins asynchronously writing them. The
4336 	 * only way to wait for these asynchronous writes is to sleep
4337 	 * on the filesystem vnode which may stay busy for a long time
4338 	 * if the filesystem is active. So, instead, we make a second
4339 	 * pass over the dependencies blocking on each write. In the
4340 	 * usual case we will be blocking against a write that we
4341 	 * initiated, so when it is done the dependency will have been
4342 	 * resolved. Thus the second pass is expected to end quickly.
4343 	 * We give a brief window at the top of the loop to allow
4344 	 * any pending I/O to complete.
4345 	 */
4346 	for (waitfor = MNT_NOWAIT; ; ) {
4347 		FREE_LOCK(&lk);
4348 		ACQUIRE_LOCK(&lk);
4349 		if (inodedep_lookup(fs, ino, 0, &inodedep) == 0)
4350 			return (0);
4351 		TAILQ_FOREACH(adp, &inodedep->id_inoupdt, ad_next) {
4352 			if (adp->ad_state & DEPCOMPLETE)
4353 				continue;
4354 			bp = adp->ad_buf;
4355 			if (getdirtybuf(&bp, waitfor) == 0) {
4356 				if (waitfor == MNT_NOWAIT)
4357 					continue;
4358 				break;
4359 			}
4360 			FREE_LOCK(&lk);
4361 			if (waitfor == MNT_NOWAIT) {
4362 				bawrite(bp);
4363 			} else if ((error = VOP_BWRITE(bp->b_vp, bp)) != 0) {
4364 				ACQUIRE_LOCK(&lk);
4365 				return (error);
4366 			}
4367 			ACQUIRE_LOCK(&lk);
4368 			break;
4369 		}
4370 		if (adp != NULL)
4371 			continue;
4372 		TAILQ_FOREACH(adp, &inodedep->id_newinoupdt, ad_next) {
4373 			if (adp->ad_state & DEPCOMPLETE)
4374 				continue;
4375 			bp = adp->ad_buf;
4376 			if (getdirtybuf(&bp, waitfor) == 0) {
4377 				if (waitfor == MNT_NOWAIT)
4378 					continue;
4379 				break;
4380 			}
4381 			FREE_LOCK(&lk);
4382 			if (waitfor == MNT_NOWAIT) {
4383 				bawrite(bp);
4384 			} else if ((error = VOP_BWRITE(bp->b_vp, bp)) != 0) {
4385 				ACQUIRE_LOCK(&lk);
4386 				return (error);
4387 			}
4388 			ACQUIRE_LOCK(&lk);
4389 			break;
4390 		}
4391 		if (adp != NULL)
4392 			continue;
4393 		/*
4394 		 * If pass2, we are done, otherwise do pass 2.
4395 		 */
4396 		if (waitfor == MNT_WAIT)
4397 			break;
4398 		waitfor = MNT_WAIT;
4399 	}
4400 	/*
4401 	 * Try freeing inodedep in case all dependencies have been removed.
4402 	 */
4403 	if (inodedep_lookup(fs, ino, 0, &inodedep) != 0)
4404 		(void) free_inodedep(inodedep);
4405 	return (0);
4406 }
4407 
4408 /*
4409  * Eliminate a pagedep dependency by flushing out all its diradd dependencies.
4410  * Called with splbio blocked.
4411  */
4412 static int
4413 flush_pagedep_deps(pvp, mp, diraddhdp)
4414 	struct vnode *pvp;
4415 	struct mount *mp;
4416 	struct diraddhd *diraddhdp;
4417 {
4418 	struct thread *td = curthread;		/* XXX */
4419 	struct inodedep *inodedep;
4420 	struct ufsmount *ump;
4421 	struct diradd *dap;
4422 	struct vnode *vp;
4423 	int gotit, error = 0;
4424 	struct buf *bp;
4425 	ino_t inum;
4426 
4427 	ump = VFSTOUFS(mp);
4428 	while ((dap = LIST_FIRST(diraddhdp)) != NULL) {
4429 		/*
4430 		 * Flush ourselves if this directory entry
4431 		 * has a MKDIR_PARENT dependency.
4432 		 */
4433 		if (dap->da_state & MKDIR_PARENT) {
4434 			FREE_LOCK(&lk);
4435 			if ((error = UFS_UPDATE(pvp, 1)) != 0)
4436 				break;
4437 			ACQUIRE_LOCK(&lk);
4438 			/*
4439 			 * If that cleared dependencies, go on to next.
4440 			 */
4441 			if (dap != LIST_FIRST(diraddhdp))
4442 				continue;
4443 			if (dap->da_state & MKDIR_PARENT) {
4444 				FREE_LOCK(&lk);
4445 				panic("flush_pagedep_deps: MKDIR_PARENT");
4446 			}
4447 		}
4448 		/*
4449 		 * A newly allocated directory must have its "." and
4450 		 * ".." entries written out before its name can be
4451 		 * committed in its parent. We do not want or need
4452 		 * the full semantics of a synchronous VOP_FSYNC as
4453 		 * that may end up here again, once for each directory
4454 		 * level in the filesystem. Instead, we push the blocks
4455 		 * and wait for them to clear. We have to fsync twice
4456 		 * because the first call may choose to defer blocks
4457 		 * that still have dependencies, but deferral will
4458 		 * happen at most once.
4459 		 */
4460 		inum = dap->da_newinum;
4461 		if (dap->da_state & MKDIR_BODY) {
4462 			FREE_LOCK(&lk);
4463 			if ((error = VFS_VGET(mp, inum, &vp)) != 0)
4464 				break;
4465 			if ((error=VOP_FSYNC(vp, MNT_NOWAIT, td)) ||
4466 			    (error=VOP_FSYNC(vp, MNT_NOWAIT, td))) {
4467 				vput(vp);
4468 				break;
4469 			}
4470 			drain_output(vp, 0);
4471 			vput(vp);
4472 			ACQUIRE_LOCK(&lk);
4473 			/*
4474 			 * If that cleared dependencies, go on to next.
4475 			 */
4476 			if (dap != LIST_FIRST(diraddhdp))
4477 				continue;
4478 			if (dap->da_state & MKDIR_BODY) {
4479 				FREE_LOCK(&lk);
4480 				panic("flush_pagedep_deps: MKDIR_BODY");
4481 			}
4482 		}
4483 		/*
4484 		 * Flush the inode on which the directory entry depends.
4485 		 * Having accounted for MKDIR_PARENT and MKDIR_BODY above,
4486 		 * the only remaining dependency is that the updated inode
4487 		 * count must get pushed to disk. The inode has already
4488 		 * been pushed into its inode buffer (via VOP_UPDATE) at
4489 		 * the time of the reference count change. So we need only
4490 		 * locate that buffer, ensure that there will be no rollback
4491 		 * caused by a bitmap dependency, then write the inode buffer.
4492 		 */
4493 		if (inodedep_lookup(ump->um_fs, inum, 0, &inodedep) == 0) {
4494 			FREE_LOCK(&lk);
4495 			panic("flush_pagedep_deps: lost inode");
4496 		}
4497 		/*
4498 		 * If the inode still has bitmap dependencies,
4499 		 * push them to disk.
4500 		 */
4501 		if ((inodedep->id_state & DEPCOMPLETE) == 0) {
4502 			gotit = getdirtybuf(&inodedep->id_buf, MNT_WAIT);
4503 			FREE_LOCK(&lk);
4504 			if (gotit &&
4505 			    (error = VOP_BWRITE(inodedep->id_buf->b_vp,
4506 			     inodedep->id_buf)) != 0)
4507 				break;
4508 			ACQUIRE_LOCK(&lk);
4509 			if (dap != LIST_FIRST(diraddhdp))
4510 				continue;
4511 		}
4512 		/*
4513 		 * If the inode is still sitting in a buffer waiting
4514 		 * to be written, push it to disk.
4515 		 */
4516 		FREE_LOCK(&lk);
4517 		if ((error = bread(ump->um_devvp,
4518 		    fsbtodb(ump->um_fs, ino_to_fsba(ump->um_fs, inum)),
4519 		    (int)ump->um_fs->fs_bsize, &bp)) != 0)
4520 			break;
4521 		if ((error = VOP_BWRITE(bp->b_vp, bp)) != 0)
4522 			break;
4523 		ACQUIRE_LOCK(&lk);
4524 		/*
4525 		 * If we have failed to get rid of all the dependencies
4526 		 * then something is seriously wrong.
4527 		 */
4528 		if (dap == LIST_FIRST(diraddhdp)) {
4529 			FREE_LOCK(&lk);
4530 			panic("flush_pagedep_deps: flush failed");
4531 		}
4532 	}
4533 	if (error)
4534 		ACQUIRE_LOCK(&lk);
4535 	return (error);
4536 }
4537 
4538 /*
4539  * A large burst of file addition or deletion activity can drive the
4540  * memory load excessively high. First attempt to slow things down
4541  * using the techniques below. If that fails, this routine requests
4542  * the offending operations to fall back to running synchronously
4543  * until the memory load returns to a reasonable level.
4544  */
4545 int
4546 softdep_slowdown(vp)
4547 	struct vnode *vp;
4548 {
4549 	int max_softdeps_hard;
4550 
4551 	max_softdeps_hard = max_softdeps * 11 / 10;
4552 	if (num_dirrem < max_softdeps_hard / 2 &&
4553 	    num_inodedep < max_softdeps_hard)
4554 		return (0);
4555 	stat_sync_limit_hit += 1;
4556 	return (1);
4557 }
4558 
4559 /*
4560  * If memory utilization has gotten too high, deliberately slow things
4561  * down and speed up the I/O processing.
4562  */
4563 static int
4564 request_cleanup(resource, islocked)
4565 	int resource;
4566 	int islocked;
4567 {
4568 	struct thread *td = curthread;		/* XXX */
4569 
4570 	/*
4571 	 * We never hold up the filesystem syncer process.
4572 	 */
4573 	if (td == filesys_syncer)
4574 		return (0);
4575 	/*
4576 	 * First check to see if the work list has gotten backlogged.
4577 	 * If it has, co-opt this process to help clean up two entries.
4578 	 * Because this process may hold inodes locked, we cannot
4579 	 * handle any remove requests that might block on a locked
4580 	 * inode as that could lead to deadlock.
4581 	 */
4582 	if (num_on_worklist > max_softdeps / 10) {
4583 		if (islocked)
4584 			FREE_LOCK(&lk);
4585 		process_worklist_item(NULL, LK_NOWAIT);
4586 		process_worklist_item(NULL, LK_NOWAIT);
4587 		stat_worklist_push += 2;
4588 		if (islocked)
4589 			ACQUIRE_LOCK(&lk);
4590 		return(1);
4591 	}
4592 
4593 	/*
4594 	 * If we are resource constrained on inode dependencies, try
4595 	 * flushing some dirty inodes. Otherwise, we are constrained
4596 	 * by file deletions, so try accelerating flushes of directories
4597 	 * with removal dependencies. We would like to do the cleanup
4598 	 * here, but we probably hold an inode locked at this point and
4599 	 * that might deadlock against one that we try to clean. So,
4600 	 * the best that we can do is request the syncer daemon to do
4601 	 * the cleanup for us.
4602 	 */
4603 	switch (resource) {
4604 
4605 	case FLUSH_INODES:
4606 		stat_ino_limit_push += 1;
4607 		req_clear_inodedeps += 1;
4608 		stat_countp = &stat_ino_limit_hit;
4609 		break;
4610 
4611 	case FLUSH_REMOVE:
4612 		stat_blk_limit_push += 1;
4613 		req_clear_remove += 1;
4614 		stat_countp = &stat_blk_limit_hit;
4615 		break;
4616 
4617 	default:
4618 		if (islocked)
4619 			FREE_LOCK(&lk);
4620 		panic("request_cleanup: unknown type");
4621 	}
4622 	/*
4623 	 * Hopefully the syncer daemon will catch up and awaken us.
4624 	 * We wait at most tickdelay before proceeding in any case.
4625 	 */
4626 	if (islocked == 0)
4627 		ACQUIRE_LOCK(&lk);
4628 	proc_waiting += 1;
4629 	if (handle.callout == NULL)
4630 		handle = timeout(pause_timer, 0, tickdelay > 2 ? tickdelay : 2);
4631 	interlocked_sleep(&lk, SLEEP, (caddr_t)&proc_waiting, 0,
4632 	    "softupdate", 0);
4633 	proc_waiting -= 1;
4634 	if (islocked == 0)
4635 		FREE_LOCK(&lk);
4636 	return (1);
4637 }
4638 
4639 /*
4640  * Awaken processes pausing in request_cleanup and clear proc_waiting
4641  * to indicate that there is no longer a timer running.
4642  */
4643 void
4644 pause_timer(arg)
4645 	void *arg;
4646 {
4647 
4648 	*stat_countp += 1;
4649 	wakeup_one(&proc_waiting);
4650 	if (proc_waiting > 0)
4651 		handle = timeout(pause_timer, 0, tickdelay > 2 ? tickdelay : 2);
4652 	else
4653 		handle.callout = NULL;
4654 }
4655 
4656 /*
4657  * Flush out a directory with at least one removal dependency in an effort to
4658  * reduce the number of dirrem, freefile, and freeblks dependency structures.
4659  */
4660 static void
4661 clear_remove(struct thread *td)
4662 {
4663 	struct pagedep_hashhead *pagedephd;
4664 	struct pagedep *pagedep;
4665 	static int next = 0;
4666 	struct mount *mp;
4667 	struct vnode *vp;
4668 	int error, cnt;
4669 	ino_t ino;
4670 
4671 	ACQUIRE_LOCK(&lk);
4672 	for (cnt = 0; cnt < pagedep_hash; cnt++) {
4673 		pagedephd = &pagedep_hashtbl[next++];
4674 		if (next >= pagedep_hash)
4675 			next = 0;
4676 		LIST_FOREACH(pagedep, pagedephd, pd_hash) {
4677 			if (LIST_FIRST(&pagedep->pd_dirremhd) == NULL)
4678 				continue;
4679 			mp = pagedep->pd_mnt;
4680 			ino = pagedep->pd_ino;
4681 			FREE_LOCK(&lk);
4682 			if ((error = VFS_VGET(mp, ino, &vp)) != 0) {
4683 				softdep_error("clear_remove: vget", error);
4684 				return;
4685 			}
4686 			if ((error = VOP_FSYNC(vp, MNT_NOWAIT, td)))
4687 				softdep_error("clear_remove: fsync", error);
4688 			drain_output(vp, 0);
4689 			vput(vp);
4690 			return;
4691 		}
4692 	}
4693 	FREE_LOCK(&lk);
4694 }
4695 
4696 /*
4697  * Clear out a block of dirty inodes in an effort to reduce
4698  * the number of inodedep dependency structures.
4699  */
4700 static void
4701 clear_inodedeps(struct thread *td)
4702 {
4703 	struct inodedep_hashhead *inodedephd;
4704 	struct inodedep *inodedep;
4705 	static int next = 0;
4706 	struct mount *mp;
4707 	struct vnode *vp;
4708 	struct fs *fs;
4709 	int error, cnt;
4710 	ino_t firstino, lastino, ino;
4711 
4712 	ACQUIRE_LOCK(&lk);
4713 	/*
4714 	 * Pick a random inode dependency to be cleared.
4715 	 * We will then gather up all the inodes in its block
4716 	 * that have dependencies and flush them out.
4717 	 */
4718 	for (cnt = 0; cnt < inodedep_hash; cnt++) {
4719 		inodedephd = &inodedep_hashtbl[next++];
4720 		if (next >= inodedep_hash)
4721 			next = 0;
4722 		if ((inodedep = LIST_FIRST(inodedephd)) != NULL)
4723 			break;
4724 	}
4725 	if (inodedep == NULL)
4726 		return;
4727 	/*
4728 	 * Ugly code to find mount point given pointer to superblock.
4729 	 */
4730 	fs = inodedep->id_fs;
4731 	TAILQ_FOREACH(mp, &mountlist, mnt_list)
4732 		if ((mp->mnt_flag & MNT_SOFTDEP) && fs == VFSTOUFS(mp)->um_fs)
4733 			break;
4734 	/*
4735 	 * Find the last inode in the block with dependencies.
4736 	 */
4737 	firstino = inodedep->id_ino & ~(INOPB(fs) - 1);
4738 	for (lastino = firstino + INOPB(fs) - 1; lastino > firstino; lastino--)
4739 		if (inodedep_lookup(fs, lastino, 0, &inodedep) != 0)
4740 			break;
4741 	/*
4742 	 * Asynchronously push all but the last inode with dependencies.
4743 	 * Synchronously push the last inode with dependencies to ensure
4744 	 * that the inode block gets written to free up the inodedeps.
4745 	 */
4746 	for (ino = firstino; ino <= lastino; ino++) {
4747 		if (inodedep_lookup(fs, ino, 0, &inodedep) == 0)
4748 			continue;
4749 		FREE_LOCK(&lk);
4750 		if ((error = VFS_VGET(mp, ino, &vp)) != 0) {
4751 			softdep_error("clear_inodedeps: vget", error);
4752 			return;
4753 		}
4754 		if (ino == lastino) {
4755 			if ((error = VOP_FSYNC(vp, MNT_WAIT, td)))
4756 				softdep_error("clear_inodedeps: fsync1", error);
4757 		} else {
4758 			if ((error = VOP_FSYNC(vp, MNT_NOWAIT, td)))
4759 				softdep_error("clear_inodedeps: fsync2", error);
4760 			drain_output(vp, 0);
4761 		}
4762 		vput(vp);
4763 		ACQUIRE_LOCK(&lk);
4764 	}
4765 	FREE_LOCK(&lk);
4766 }
4767 
4768 /*
4769  * Function to determine if the buffer has outstanding dependencies
4770  * that will cause a roll-back if the buffer is written. If wantcount
4771  * is set, return number of dependencies, otherwise just yes or no.
4772  */
4773 static int
4774 softdep_count_dependencies(bp, wantcount)
4775 	struct buf *bp;
4776 	int wantcount;
4777 {
4778 	struct worklist *wk;
4779 	struct inodedep *inodedep;
4780 	struct indirdep *indirdep;
4781 	struct allocindir *aip;
4782 	struct pagedep *pagedep;
4783 	struct diradd *dap;
4784 	int i, retval;
4785 
4786 	retval = 0;
4787 	ACQUIRE_LOCK(&lk);
4788 	LIST_FOREACH(wk, &bp->b_dep, wk_list) {
4789 		switch (wk->wk_type) {
4790 
4791 		case D_INODEDEP:
4792 			inodedep = WK_INODEDEP(wk);
4793 			if ((inodedep->id_state & DEPCOMPLETE) == 0) {
4794 				/* bitmap allocation dependency */
4795 				retval += 1;
4796 				if (!wantcount)
4797 					goto out;
4798 			}
4799 			if (TAILQ_FIRST(&inodedep->id_inoupdt)) {
4800 				/* direct block pointer dependency */
4801 				retval += 1;
4802 				if (!wantcount)
4803 					goto out;
4804 			}
4805 			continue;
4806 
4807 		case D_INDIRDEP:
4808 			indirdep = WK_INDIRDEP(wk);
4809 
4810 			LIST_FOREACH(aip, &indirdep->ir_deplisthd, ai_next) {
4811 				/* indirect block pointer dependency */
4812 				retval += 1;
4813 				if (!wantcount)
4814 					goto out;
4815 			}
4816 			continue;
4817 
4818 		case D_PAGEDEP:
4819 			pagedep = WK_PAGEDEP(wk);
4820 			for (i = 0; i < DAHASHSZ; i++) {
4821 
4822 				LIST_FOREACH(dap, &pagedep->pd_diraddhd[i], da_pdlist) {
4823 					/* directory entry dependency */
4824 					retval += 1;
4825 					if (!wantcount)
4826 						goto out;
4827 				}
4828 			}
4829 			continue;
4830 
4831 		case D_BMSAFEMAP:
4832 		case D_ALLOCDIRECT:
4833 		case D_ALLOCINDIR:
4834 		case D_MKDIR:
4835 			/* never a dependency on these blocks */
4836 			continue;
4837 
4838 		default:
4839 			FREE_LOCK(&lk);
4840 			panic("softdep_check_for_rollback: Unexpected type %s",
4841 			    TYPENAME(wk->wk_type));
4842 			/* NOTREACHED */
4843 		}
4844 	}
4845 out:
4846 	FREE_LOCK(&lk);
4847 	return retval;
4848 }
4849 
4850 /*
4851  * Acquire exclusive access to a buffer.
4852  * Must be called with splbio blocked.
4853  * Return 1 if buffer was acquired.
4854  */
4855 static int
4856 getdirtybuf(bpp, waitfor)
4857 	struct buf **bpp;
4858 	int waitfor;
4859 {
4860 	struct buf *bp;
4861 	int error;
4862 
4863 	for (;;) {
4864 		if ((bp = *bpp) == NULL)
4865 			return (0);
4866 		if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT) == 0) {
4867 			if ((bp->b_xflags & BX_BKGRDINPROG) == 0)
4868 				break;
4869 			BUF_UNLOCK(bp);
4870 			if (waitfor != MNT_WAIT)
4871 				return (0);
4872 			bp->b_xflags |= BX_BKGRDWAIT;
4873 			interlocked_sleep(&lk, SLEEP, &bp->b_xflags, 0,
4874 			    "getbuf", 0);
4875 			continue;
4876 		}
4877 		if (waitfor != MNT_WAIT)
4878 			return (0);
4879 		error = interlocked_sleep(&lk, LOCKBUF, bp,
4880 		    LK_EXCLUSIVE | LK_SLEEPFAIL, 0, 0);
4881 		if (error != ENOLCK) {
4882 			FREE_LOCK(&lk);
4883 			panic("getdirtybuf: inconsistent lock");
4884 		}
4885 	}
4886 	if ((bp->b_flags & B_DELWRI) == 0) {
4887 		BUF_UNLOCK(bp);
4888 		return (0);
4889 	}
4890 	bremfree(bp);
4891 	return (1);
4892 }
4893 
4894 /*
4895  * Wait for pending output on a vnode to complete.
4896  * Must be called with vnode locked.
4897  */
4898 static void
4899 drain_output(vp, islocked)
4900 	struct vnode *vp;
4901 	int islocked;
4902 {
4903 
4904 	if (!islocked)
4905 		ACQUIRE_LOCK(&lk);
4906 	while (vp->v_numoutput) {
4907 		vp->v_flag |= VBWAIT;
4908 		interlocked_sleep(&lk, SLEEP, (caddr_t)&vp->v_numoutput,
4909 		    0, "drainvp", 0);
4910 	}
4911 	if (!islocked)
4912 		FREE_LOCK(&lk);
4913 }
4914 
4915 /*
4916  * Called whenever a buffer that is being invalidated or reallocated
4917  * contains dependencies. This should only happen if an I/O error has
4918  * occurred. The routine is called with the buffer locked.
4919  */
4920 static void
4921 softdep_deallocate_dependencies(bp)
4922 	struct buf *bp;
4923 {
4924 
4925 	if ((bp->b_flags & B_ERROR) == 0)
4926 		panic("softdep_deallocate_dependencies: dangling deps");
4927 	softdep_error(bp->b_vp->v_mount->mnt_stat.f_mntonname, bp->b_error);
4928 	panic("softdep_deallocate_dependencies: unrecovered I/O error");
4929 }
4930 
4931 /*
4932  * Function to handle asynchronous write errors in the filesystem.
4933  */
4934 void
4935 softdep_error(func, error)
4936 	char *func;
4937 	int error;
4938 {
4939 
4940 	/* XXX should do something better! */
4941 	printf("%s: got error %d while accessing filesystem\n", func, error);
4942 }
4943