xref: /dragonfly/sys/vfs/ufs/ffs_softdep.c (revision f746689a)
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 1.57 2008/06/28 17:59:51 dillon Exp $
41  */
42 
43 /*
44  * For now we want the safety net that the DIAGNOSTIC and DEBUG flags provide.
45  */
46 #ifndef DIAGNOSTIC
47 #define DIAGNOSTIC
48 #endif
49 #ifndef DEBUG
50 #define DEBUG
51 #endif
52 
53 #include <sys/param.h>
54 #include <sys/kernel.h>
55 #include <sys/systm.h>
56 #include <sys/buf.h>
57 #include <sys/malloc.h>
58 #include <sys/mount.h>
59 #include <sys/proc.h>
60 #include <sys/syslog.h>
61 #include <sys/vnode.h>
62 #include <sys/conf.h>
63 #include <sys/buf2.h>
64 #include <machine/inttypes.h>
65 #include "dir.h"
66 #include "quota.h"
67 #include "inode.h"
68 #include "ufsmount.h"
69 #include "fs.h"
70 #include "softdep.h"
71 #include "ffs_extern.h"
72 #include "ufs_extern.h"
73 
74 #include <sys/thread2.h>
75 
76 /*
77  * These definitions need to be adapted to the system to which
78  * this file is being ported.
79  */
80 /*
81  * malloc types defined for the softdep system.
82  */
83 MALLOC_DEFINE(M_PAGEDEP, "pagedep","File page dependencies");
84 MALLOC_DEFINE(M_INODEDEP, "inodedep","Inode dependencies");
85 MALLOC_DEFINE(M_NEWBLK, "newblk","New block allocation");
86 MALLOC_DEFINE(M_BMSAFEMAP, "bmsafemap","Block or frag allocated from cyl group map");
87 MALLOC_DEFINE(M_ALLOCDIRECT, "allocdirect","Block or frag dependency for an inode");
88 MALLOC_DEFINE(M_INDIRDEP, "indirdep","Indirect block dependencies");
89 MALLOC_DEFINE(M_ALLOCINDIR, "allocindir","Block dependency for an indirect block");
90 MALLOC_DEFINE(M_FREEFRAG, "freefrag","Previously used frag for an inode");
91 MALLOC_DEFINE(M_FREEBLKS, "freeblks","Blocks freed from an inode");
92 MALLOC_DEFINE(M_FREEFILE, "freefile","Inode deallocated");
93 MALLOC_DEFINE(M_DIRADD, "diradd","New directory entry");
94 MALLOC_DEFINE(M_MKDIR, "mkdir","New directory");
95 MALLOC_DEFINE(M_DIRREM, "dirrem","Directory entry deleted");
96 
97 #define M_SOFTDEP_FLAGS		(M_WAITOK | M_USE_RESERVE)
98 
99 #define	D_PAGEDEP	0
100 #define	D_INODEDEP	1
101 #define	D_NEWBLK	2
102 #define	D_BMSAFEMAP	3
103 #define	D_ALLOCDIRECT	4
104 #define	D_INDIRDEP	5
105 #define	D_ALLOCINDIR	6
106 #define	D_FREEFRAG	7
107 #define	D_FREEBLKS	8
108 #define	D_FREEFILE	9
109 #define	D_DIRADD	10
110 #define	D_MKDIR		11
111 #define	D_DIRREM	12
112 #define D_LAST		D_DIRREM
113 
114 /*
115  * translate from workitem type to memory type
116  * MUST match the defines above, such that memtype[D_XXX] == M_XXX
117  */
118 static struct malloc_type *memtype[] = {
119 	M_PAGEDEP,
120 	M_INODEDEP,
121 	M_NEWBLK,
122 	M_BMSAFEMAP,
123 	M_ALLOCDIRECT,
124 	M_INDIRDEP,
125 	M_ALLOCINDIR,
126 	M_FREEFRAG,
127 	M_FREEBLKS,
128 	M_FREEFILE,
129 	M_DIRADD,
130 	M_MKDIR,
131 	M_DIRREM
132 };
133 
134 #define DtoM(type) (memtype[type])
135 
136 /*
137  * Names of malloc types.
138  */
139 #define TYPENAME(type)  \
140 	((unsigned)(type) < D_LAST ? memtype[type]->ks_shortdesc : "???")
141 /*
142  * End system adaptaion definitions.
143  */
144 
145 /*
146  * Internal function prototypes.
147  */
148 static	void softdep_error(char *, int);
149 static	void drain_output(struct vnode *, int);
150 static	int getdirtybuf(struct buf **, int);
151 static	void clear_remove(struct thread *);
152 static	void clear_inodedeps(struct thread *);
153 static	int flush_pagedep_deps(struct vnode *, struct mount *,
154 	    struct diraddhd *);
155 static	int flush_inodedep_deps(struct fs *, ino_t);
156 static	int handle_written_filepage(struct pagedep *, struct buf *);
157 static  void diradd_inode_written(struct diradd *, struct inodedep *);
158 static	int handle_written_inodeblock(struct inodedep *, struct buf *);
159 static	void handle_allocdirect_partdone(struct allocdirect *);
160 static	void handle_allocindir_partdone(struct allocindir *);
161 static	void initiate_write_filepage(struct pagedep *, struct buf *);
162 static	void handle_written_mkdir(struct mkdir *, int);
163 static	void initiate_write_inodeblock(struct inodedep *, struct buf *);
164 static	void handle_workitem_freefile(struct freefile *);
165 static	void handle_workitem_remove(struct dirrem *);
166 static	struct dirrem *newdirrem(struct buf *, struct inode *,
167 	    struct inode *, int, struct dirrem **);
168 static	void free_diradd(struct diradd *);
169 static	void free_allocindir(struct allocindir *, struct inodedep *);
170 static	int indir_trunc (struct inode *, off_t, int, ufs_lbn_t, long *);
171 static	void deallocate_dependencies(struct buf *, struct inodedep *);
172 static	void free_allocdirect(struct allocdirectlst *,
173 	    struct allocdirect *, int);
174 static	int check_inode_unwritten(struct inodedep *);
175 static	int free_inodedep(struct inodedep *);
176 static	void handle_workitem_freeblocks(struct freeblks *);
177 static	void merge_inode_lists(struct inodedep *);
178 static	void setup_allocindir_phase2(struct buf *, struct inode *,
179 	    struct allocindir *);
180 static	struct allocindir *newallocindir(struct inode *, int, ufs_daddr_t,
181 	    ufs_daddr_t);
182 static	void handle_workitem_freefrag(struct freefrag *);
183 static	struct freefrag *newfreefrag(struct inode *, ufs_daddr_t, long);
184 static	void allocdirect_merge(struct allocdirectlst *,
185 	    struct allocdirect *, struct allocdirect *);
186 static	struct bmsafemap *bmsafemap_lookup(struct buf *);
187 static	int newblk_lookup(struct fs *, ufs_daddr_t, int,
188 	    struct newblk **);
189 static	int inodedep_lookup(struct fs *, ino_t, int, struct inodedep **);
190 static	int pagedep_lookup(struct inode *, ufs_lbn_t, int,
191 	    struct pagedep **);
192 static	void pause_timer(void *);
193 static	int request_cleanup(int, int);
194 static	int process_worklist_item(struct mount *, int);
195 static	void add_to_worklist(struct worklist *);
196 
197 /*
198  * Exported softdep operations.
199  */
200 static	void softdep_disk_io_initiation(struct buf *);
201 static	void softdep_disk_write_complete(struct buf *);
202 static	void softdep_deallocate_dependencies(struct buf *);
203 static	int softdep_fsync(struct vnode *);
204 static	int softdep_process_worklist(struct mount *);
205 static	void softdep_move_dependencies(struct buf *, struct buf *);
206 static	int softdep_count_dependencies(struct buf *bp, int);
207 static  int softdep_checkread(struct buf *bp);
208 static  int softdep_checkwrite(struct buf *bp);
209 
210 static struct bio_ops softdep_bioops = {
211 	.io_start = softdep_disk_io_initiation,
212 	.io_complete = softdep_disk_write_complete,
213 	.io_deallocate = softdep_deallocate_dependencies,
214 	.io_fsync = softdep_fsync,
215 	.io_sync = softdep_process_worklist,
216 	.io_movedeps = softdep_move_dependencies,
217 	.io_countdeps = softdep_count_dependencies,
218 	.io_checkread = softdep_checkread,
219 	.io_checkwrite = softdep_checkwrite
220 };
221 
222 /*
223  * Locking primitives.
224  *
225  * For a uniprocessor, all we need to do is protect against disk
226  * interrupts. For a multiprocessor, this lock would have to be
227  * a mutex. A single mutex is used throughout this file, though
228  * finer grain locking could be used if contention warranted it.
229  *
230  * For a multiprocessor, the sleep call would accept a lock and
231  * release it after the sleep processing was complete. In a uniprocessor
232  * implementation there is no such interlock, so we simple mark
233  * the places where it needs to be done with the `interlocked' form
234  * of the lock calls. Since the uniprocessor sleep already interlocks
235  * the spl, there is nothing that really needs to be done.
236  */
237 #ifndef /* NOT */ DEBUG
238 static struct lockit {
239 } lk = { 0 };
240 #define ACQUIRE_LOCK(lk)		crit_enter_id("softupdates");
241 #define FREE_LOCK(lk)			crit_exit_id("softupdates");
242 
243 #else /* DEBUG */
244 #define NOHOLDER	((struct thread *)-1)
245 #define SPECIAL_FLAG	((struct thread *)-2)
246 static struct lockit {
247 	int	lkt_spl;
248 	struct thread *lkt_held;
249 } lk = { 0, NOHOLDER };
250 static int lockcnt;
251 
252 static	void acquire_lock(struct lockit *);
253 static	void free_lock(struct lockit *);
254 void	softdep_panic(char *);
255 
256 #define ACQUIRE_LOCK(lk)		acquire_lock(lk)
257 #define FREE_LOCK(lk)			free_lock(lk)
258 
259 static void
260 acquire_lock(struct lockit *lk)
261 {
262 	thread_t holder;
263 
264 	if (lk->lkt_held != NOHOLDER) {
265 		holder = lk->lkt_held;
266 		FREE_LOCK(lk);
267 		if (holder == curthread)
268 			panic("softdep_lock: locking against myself");
269 		else
270 			panic("softdep_lock: lock held by %p", holder);
271 	}
272 	crit_enter_id("softupdates");
273 	lk->lkt_held = curthread;
274 	lockcnt++;
275 }
276 
277 static void
278 free_lock(struct lockit *lk)
279 {
280 
281 	if (lk->lkt_held == NOHOLDER)
282 		panic("softdep_unlock: lock not held");
283 	lk->lkt_held = NOHOLDER;
284 	crit_exit_id("softupdates");
285 }
286 
287 /*
288  * Function to release soft updates lock and panic.
289  */
290 void
291 softdep_panic(char *msg)
292 {
293 
294 	if (lk.lkt_held != NOHOLDER)
295 		FREE_LOCK(&lk);
296 	panic(msg);
297 }
298 #endif /* DEBUG */
299 
300 static	int interlocked_sleep(struct lockit *, int, void *, int,
301 	    const char *, int);
302 
303 /*
304  * When going to sleep, we must save our SPL so that it does
305  * not get lost if some other process uses the lock while we
306  * are sleeping. We restore it after we have slept. This routine
307  * wraps the interlocking with functions that sleep. The list
308  * below enumerates the available set of operations.
309  */
310 #define	UNKNOWN		0
311 #define	SLEEP		1
312 #define	LOCKBUF		2
313 
314 static int
315 interlocked_sleep(struct lockit *lk, int op, void *ident, int flags,
316 		  const char *wmesg, int timo)
317 {
318 	thread_t holder;
319 	int s, retval;
320 
321 	s = lk->lkt_spl;
322 #	ifdef DEBUG
323 	if (lk->lkt_held == NOHOLDER)
324 		panic("interlocked_sleep: lock not held");
325 	lk->lkt_held = NOHOLDER;
326 #	endif /* DEBUG */
327 	switch (op) {
328 	case SLEEP:
329 		retval = tsleep(ident, flags, wmesg, timo);
330 		break;
331 	case LOCKBUF:
332 		retval = BUF_LOCK((struct buf *)ident, flags);
333 		break;
334 	default:
335 		panic("interlocked_sleep: unknown operation");
336 	}
337 #	ifdef DEBUG
338 	if (lk->lkt_held != NOHOLDER) {
339 		holder = lk->lkt_held;
340 		FREE_LOCK(lk);
341 		if (holder == curthread)
342 			panic("interlocked_sleep: locking against self");
343 		else
344 			panic("interlocked_sleep: lock held by %p", holder);
345 	}
346 	lk->lkt_held = curthread;
347 	lockcnt++;
348 #	endif /* DEBUG */
349 	lk->lkt_spl = s;
350 	return (retval);
351 }
352 
353 /*
354  * Place holder for real semaphores.
355  */
356 struct sema {
357 	int	value;
358 	thread_t holder;
359 	char	*name;
360 	int	prio;
361 	int	timo;
362 };
363 static	void sema_init(struct sema *, char *, int, int);
364 static	int sema_get(struct sema *, struct lockit *);
365 static	void sema_release(struct sema *);
366 
367 static void
368 sema_init(struct sema *semap, char *name, int prio, int timo)
369 {
370 
371 	semap->holder = NOHOLDER;
372 	semap->value = 0;
373 	semap->name = name;
374 	semap->prio = prio;
375 	semap->timo = timo;
376 }
377 
378 static int
379 sema_get(struct sema *semap, struct lockit *interlock)
380 {
381 
382 	if (semap->value++ > 0) {
383 		if (interlock != NULL) {
384 			interlocked_sleep(interlock, SLEEP, (caddr_t)semap,
385 			    semap->prio, semap->name, semap->timo);
386 			FREE_LOCK(interlock);
387 		} else {
388 			tsleep((caddr_t)semap, semap->prio, semap->name,
389 			    semap->timo);
390 		}
391 		return (0);
392 	}
393 	semap->holder = curthread;
394 	if (interlock != NULL)
395 		FREE_LOCK(interlock);
396 	return (1);
397 }
398 
399 static void
400 sema_release(struct sema *semap)
401 {
402 
403 	if (semap->value <= 0 || semap->holder != curthread) {
404 		if (lk.lkt_held != NOHOLDER)
405 			FREE_LOCK(&lk);
406 		panic("sema_release: not held");
407 	}
408 	if (--semap->value > 0) {
409 		semap->value = 0;
410 		wakeup(semap);
411 	}
412 	semap->holder = NOHOLDER;
413 }
414 
415 /*
416  * Worklist queue management.
417  * These routines require that the lock be held.
418  */
419 #ifndef /* NOT */ DEBUG
420 #define WORKLIST_INSERT(head, item) do {	\
421 	(item)->wk_state |= ONWORKLIST;		\
422 	LIST_INSERT_HEAD(head, item, wk_list);	\
423 } while (0)
424 
425 #define WORKLIST_INSERT_BP(bp, item) do {	\
426 	(item)->wk_state |= ONWORKLIST;		\
427 	(bp)->b_ops = &softdep_bioops;		\
428 	LIST_INSERT_HEAD(&(bp)->b_dep, item, wk_list);	\
429 } while (0)
430 
431 #define WORKLIST_REMOVE(item) do {		\
432 	(item)->wk_state &= ~ONWORKLIST;	\
433 	LIST_REMOVE(item, wk_list);		\
434 } while (0)
435 
436 #define WORKITEM_FREE(item, type) FREE(item, DtoM(type))
437 
438 #else /* DEBUG */
439 static	void worklist_insert(struct workhead *, struct worklist *);
440 static	void worklist_remove(struct worklist *);
441 static	void workitem_free(struct worklist *, int);
442 
443 #define WORKLIST_INSERT_BP(bp, item) do {	\
444 	(bp)->b_ops = &softdep_bioops;		\
445 	worklist_insert(&(bp)->b_dep, item);	\
446 } while (0)
447 
448 #define WORKLIST_INSERT(head, item) worklist_insert(head, item)
449 #define WORKLIST_REMOVE(item) worklist_remove(item)
450 #define WORKITEM_FREE(item, type) workitem_free((struct worklist *)item, type)
451 
452 static void
453 worklist_insert(struct workhead *head, struct worklist *item)
454 {
455 
456 	if (lk.lkt_held == NOHOLDER)
457 		panic("worklist_insert: lock not held");
458 	if (item->wk_state & ONWORKLIST) {
459 		FREE_LOCK(&lk);
460 		panic("worklist_insert: already on list");
461 	}
462 	item->wk_state |= ONWORKLIST;
463 	LIST_INSERT_HEAD(head, item, wk_list);
464 }
465 
466 static void
467 worklist_remove(struct worklist *item)
468 {
469 
470 	if (lk.lkt_held == NOHOLDER)
471 		panic("worklist_remove: lock not held");
472 	if ((item->wk_state & ONWORKLIST) == 0) {
473 		FREE_LOCK(&lk);
474 		panic("worklist_remove: not on list");
475 	}
476 	item->wk_state &= ~ONWORKLIST;
477 	LIST_REMOVE(item, wk_list);
478 }
479 
480 static void
481 workitem_free(struct worklist *item, int type)
482 {
483 
484 	if (item->wk_state & ONWORKLIST) {
485 		if (lk.lkt_held != NOHOLDER)
486 			FREE_LOCK(&lk);
487 		panic("workitem_free: still on list");
488 	}
489 	if (item->wk_type != type) {
490 		if (lk.lkt_held != NOHOLDER)
491 			FREE_LOCK(&lk);
492 		panic("workitem_free: type mismatch");
493 	}
494 	FREE(item, DtoM(type));
495 }
496 #endif /* DEBUG */
497 
498 /*
499  * Workitem queue management
500  */
501 static struct workhead softdep_workitem_pending;
502 static int num_on_worklist;	/* number of worklist items to be processed */
503 static int softdep_worklist_busy; /* 1 => trying to do unmount */
504 static int softdep_worklist_req; /* serialized waiters */
505 static int max_softdeps;	/* maximum number of structs before slowdown */
506 static int tickdelay = 2;	/* number of ticks to pause during slowdown */
507 static int *stat_countp;	/* statistic to count in proc_waiting timeout */
508 static int proc_waiting;	/* tracks whether we have a timeout posted */
509 static struct callout handle; /* handle on posted proc_waiting timeout */
510 static struct thread *filesys_syncer; /* proc of filesystem syncer process */
511 static int req_clear_inodedeps;	/* syncer process flush some inodedeps */
512 #define FLUSH_INODES	1
513 static int req_clear_remove;	/* syncer process flush some freeblks */
514 #define FLUSH_REMOVE	2
515 /*
516  * runtime statistics
517  */
518 static int stat_worklist_push;	/* number of worklist cleanups */
519 static int stat_blk_limit_push;	/* number of times block limit neared */
520 static int stat_ino_limit_push;	/* number of times inode limit neared */
521 static int stat_blk_limit_hit;	/* number of times block slowdown imposed */
522 static int stat_ino_limit_hit;	/* number of times inode slowdown imposed */
523 static int stat_sync_limit_hit;	/* number of synchronous slowdowns imposed */
524 static int stat_indir_blk_ptrs;	/* bufs redirtied as indir ptrs not written */
525 static int stat_inode_bitmap;	/* bufs redirtied as inode bitmap not written */
526 static int stat_direct_blk_ptrs;/* bufs redirtied as direct ptrs not written */
527 static int stat_dir_entry;	/* bufs redirtied as dir entry cannot write */
528 #ifdef DEBUG
529 #include <vm/vm.h>
530 #include <sys/sysctl.h>
531 SYSCTL_INT(_debug, OID_AUTO, max_softdeps, CTLFLAG_RW, &max_softdeps, 0, "");
532 SYSCTL_INT(_debug, OID_AUTO, tickdelay, CTLFLAG_RW, &tickdelay, 0, "");
533 SYSCTL_INT(_debug, OID_AUTO, worklist_push, CTLFLAG_RW, &stat_worklist_push, 0,"");
534 SYSCTL_INT(_debug, OID_AUTO, blk_limit_push, CTLFLAG_RW, &stat_blk_limit_push, 0,"");
535 SYSCTL_INT(_debug, OID_AUTO, ino_limit_push, CTLFLAG_RW, &stat_ino_limit_push, 0,"");
536 SYSCTL_INT(_debug, OID_AUTO, blk_limit_hit, CTLFLAG_RW, &stat_blk_limit_hit, 0, "");
537 SYSCTL_INT(_debug, OID_AUTO, ino_limit_hit, CTLFLAG_RW, &stat_ino_limit_hit, 0, "");
538 SYSCTL_INT(_debug, OID_AUTO, sync_limit_hit, CTLFLAG_RW, &stat_sync_limit_hit, 0, "");
539 SYSCTL_INT(_debug, OID_AUTO, indir_blk_ptrs, CTLFLAG_RW, &stat_indir_blk_ptrs, 0, "");
540 SYSCTL_INT(_debug, OID_AUTO, inode_bitmap, CTLFLAG_RW, &stat_inode_bitmap, 0, "");
541 SYSCTL_INT(_debug, OID_AUTO, direct_blk_ptrs, CTLFLAG_RW, &stat_direct_blk_ptrs, 0, "");
542 SYSCTL_INT(_debug, OID_AUTO, dir_entry, CTLFLAG_RW, &stat_dir_entry, 0, "");
543 #endif /* DEBUG */
544 
545 /*
546  * Add an item to the end of the work queue.
547  * This routine requires that the lock be held.
548  * This is the only routine that adds items to the list.
549  * The following routine is the only one that removes items
550  * and does so in order from first to last.
551  */
552 static void
553 add_to_worklist(struct worklist *wk)
554 {
555 	static struct worklist *worklist_tail;
556 
557 	if (wk->wk_state & ONWORKLIST) {
558 		if (lk.lkt_held != NOHOLDER)
559 			FREE_LOCK(&lk);
560 		panic("add_to_worklist: already on list");
561 	}
562 	wk->wk_state |= ONWORKLIST;
563 	if (LIST_FIRST(&softdep_workitem_pending) == NULL)
564 		LIST_INSERT_HEAD(&softdep_workitem_pending, wk, wk_list);
565 	else
566 		LIST_INSERT_AFTER(worklist_tail, wk, wk_list);
567 	worklist_tail = wk;
568 	num_on_worklist += 1;
569 }
570 
571 /*
572  * Process that runs once per second to handle items in the background queue.
573  *
574  * Note that we ensure that everything is done in the order in which they
575  * appear in the queue. The code below depends on this property to ensure
576  * that blocks of a file are freed before the inode itself is freed. This
577  * ordering ensures that no new <vfsid, inum, lbn> triples will be generated
578  * until all the old ones have been purged from the dependency lists.
579  */
580 static int
581 softdep_process_worklist(struct mount *matchmnt)
582 {
583 	thread_t td = curthread;
584 	int matchcnt, loopcount;
585 	long starttime;
586 
587 	/*
588 	 * Record the process identifier of our caller so that we can give
589 	 * this process preferential treatment in request_cleanup below.
590 	 */
591 	filesys_syncer = td;
592 	matchcnt = 0;
593 
594 	/*
595 	 * There is no danger of having multiple processes run this
596 	 * code, but we have to single-thread it when softdep_flushfiles()
597 	 * is in operation to get an accurate count of the number of items
598 	 * related to its mount point that are in the list.
599 	 */
600 	if (matchmnt == NULL) {
601 		if (softdep_worklist_busy < 0)
602 			return(-1);
603 		softdep_worklist_busy += 1;
604 	}
605 
606 	/*
607 	 * If requested, try removing inode or removal dependencies.
608 	 */
609 	if (req_clear_inodedeps) {
610 		clear_inodedeps(td);
611 		req_clear_inodedeps -= 1;
612 		wakeup_one(&proc_waiting);
613 	}
614 	if (req_clear_remove) {
615 		clear_remove(td);
616 		req_clear_remove -= 1;
617 		wakeup_one(&proc_waiting);
618 	}
619 	loopcount = 1;
620 	starttime = time_second;
621 	while (num_on_worklist > 0) {
622 		matchcnt += process_worklist_item(matchmnt, 0);
623 
624 		/*
625 		 * If a umount operation wants to run the worklist
626 		 * accurately, abort.
627 		 */
628 		if (softdep_worklist_req && matchmnt == NULL) {
629 			matchcnt = -1;
630 			break;
631 		}
632 
633 		/*
634 		 * If requested, try removing inode or removal dependencies.
635 		 */
636 		if (req_clear_inodedeps) {
637 			clear_inodedeps(td);
638 			req_clear_inodedeps -= 1;
639 			wakeup_one(&proc_waiting);
640 		}
641 		if (req_clear_remove) {
642 			clear_remove(td);
643 			req_clear_remove -= 1;
644 			wakeup_one(&proc_waiting);
645 		}
646 		/*
647 		 * We do not generally want to stop for buffer space, but if
648 		 * we are really being a buffer hog, we will stop and wait.
649 		 */
650 		if (loopcount++ % 128 == 0)
651 			bwillinode(1);
652 		/*
653 		 * Never allow processing to run for more than one
654 		 * second. Otherwise the other syncer tasks may get
655 		 * excessively backlogged.
656 		 */
657 		if (starttime != time_second && matchmnt == NULL) {
658 			matchcnt = -1;
659 			break;
660 		}
661 	}
662 	if (matchmnt == NULL) {
663 		--softdep_worklist_busy;
664 		if (softdep_worklist_req && softdep_worklist_busy == 0)
665 			wakeup(&softdep_worklist_req);
666 	}
667 	return (matchcnt);
668 }
669 
670 /*
671  * Process one item on the worklist.
672  */
673 static int
674 process_worklist_item(struct mount *matchmnt, int flags)
675 {
676 	struct worklist *wk;
677 	struct dirrem *dirrem;
678 	struct fs *matchfs;
679 	struct vnode *vp;
680 	int matchcnt = 0;
681 
682 	matchfs = NULL;
683 	if (matchmnt != NULL)
684 		matchfs = VFSTOUFS(matchmnt)->um_fs;
685 	ACQUIRE_LOCK(&lk);
686 	/*
687 	 * Normally we just process each item on the worklist in order.
688 	 * However, if we are in a situation where we cannot lock any
689 	 * inodes, we have to skip over any dirrem requests whose
690 	 * vnodes are resident and locked.
691 	 */
692 	LIST_FOREACH(wk, &softdep_workitem_pending, wk_list) {
693 		if ((flags & LK_NOWAIT) == 0 || wk->wk_type != D_DIRREM)
694 			break;
695 		dirrem = WK_DIRREM(wk);
696 		vp = ufs_ihashlookup(VFSTOUFS(dirrem->dm_mnt)->um_dev,
697 		    dirrem->dm_oldinum);
698 		if (vp == NULL || !vn_islocked(vp))
699 			break;
700 	}
701 	if (wk == 0) {
702 		FREE_LOCK(&lk);
703 		return (0);
704 	}
705 	WORKLIST_REMOVE(wk);
706 	num_on_worklist -= 1;
707 	FREE_LOCK(&lk);
708 	switch (wk->wk_type) {
709 
710 	case D_DIRREM:
711 		/* removal of a directory entry */
712 		if (WK_DIRREM(wk)->dm_mnt == matchmnt)
713 			matchcnt += 1;
714 		handle_workitem_remove(WK_DIRREM(wk));
715 		break;
716 
717 	case D_FREEBLKS:
718 		/* releasing blocks and/or fragments from a file */
719 		if (WK_FREEBLKS(wk)->fb_fs == matchfs)
720 			matchcnt += 1;
721 		handle_workitem_freeblocks(WK_FREEBLKS(wk));
722 		break;
723 
724 	case D_FREEFRAG:
725 		/* releasing a fragment when replaced as a file grows */
726 		if (WK_FREEFRAG(wk)->ff_fs == matchfs)
727 			matchcnt += 1;
728 		handle_workitem_freefrag(WK_FREEFRAG(wk));
729 		break;
730 
731 	case D_FREEFILE:
732 		/* releasing an inode when its link count drops to 0 */
733 		if (WK_FREEFILE(wk)->fx_fs == matchfs)
734 			matchcnt += 1;
735 		handle_workitem_freefile(WK_FREEFILE(wk));
736 		break;
737 
738 	default:
739 		panic("%s_process_worklist: Unknown type %s",
740 		    "softdep", TYPENAME(wk->wk_type));
741 		/* NOTREACHED */
742 	}
743 	return (matchcnt);
744 }
745 
746 /*
747  * Move dependencies from one buffer to another.
748  */
749 static void
750 softdep_move_dependencies(struct buf *oldbp, struct buf *newbp)
751 {
752 	struct worklist *wk, *wktail;
753 
754 	if (LIST_FIRST(&newbp->b_dep) != NULL)
755 		panic("softdep_move_dependencies: need merge code");
756 	wktail = NULL;
757 	ACQUIRE_LOCK(&lk);
758 	while ((wk = LIST_FIRST(&oldbp->b_dep)) != NULL) {
759 		LIST_REMOVE(wk, wk_list);
760 		if (wktail == NULL)
761 			LIST_INSERT_HEAD(&newbp->b_dep, wk, wk_list);
762 		else
763 			LIST_INSERT_AFTER(wktail, wk, wk_list);
764 		wktail = wk;
765 		newbp->b_ops = &softdep_bioops;
766 	}
767 	FREE_LOCK(&lk);
768 }
769 
770 /*
771  * Purge the work list of all items associated with a particular mount point.
772  */
773 int
774 softdep_flushfiles(struct mount *oldmnt, int flags)
775 {
776 	struct vnode *devvp;
777 	int error, loopcnt;
778 
779 	/*
780 	 * Await our turn to clear out the queue, then serialize access.
781 	 */
782 	while (softdep_worklist_busy != 0) {
783 		softdep_worklist_req += 1;
784 		tsleep(&softdep_worklist_req, 0, "softflush", 0);
785 		softdep_worklist_req -= 1;
786 	}
787 	softdep_worklist_busy = -1;
788 
789 	if ((error = ffs_flushfiles(oldmnt, flags)) != 0) {
790 		softdep_worklist_busy = 0;
791 		if (softdep_worklist_req)
792 			wakeup(&softdep_worklist_req);
793 		return (error);
794 	}
795 	/*
796 	 * Alternately flush the block device associated with the mount
797 	 * point and process any dependencies that the flushing
798 	 * creates. In theory, this loop can happen at most twice,
799 	 * but we give it a few extra just to be sure.
800 	 */
801 	devvp = VFSTOUFS(oldmnt)->um_devvp;
802 	for (loopcnt = 10; loopcnt > 0; ) {
803 		if (softdep_process_worklist(oldmnt) == 0) {
804 			loopcnt--;
805 			/*
806 			 * Do another flush in case any vnodes were brought in
807 			 * as part of the cleanup operations.
808 			 */
809 			if ((error = ffs_flushfiles(oldmnt, flags)) != 0)
810 				break;
811 			/*
812 			 * If we still found nothing to do, we are really done.
813 			 */
814 			if (softdep_process_worklist(oldmnt) == 0)
815 				break;
816 		}
817 		vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
818 		error = VOP_FSYNC(devvp, MNT_WAIT);
819 		vn_unlock(devvp);
820 		if (error)
821 			break;
822 	}
823 	softdep_worklist_busy = 0;
824 	if (softdep_worklist_req)
825 		wakeup(&softdep_worklist_req);
826 
827 	/*
828 	 * If we are unmounting then it is an error to fail. If we
829 	 * are simply trying to downgrade to read-only, then filesystem
830 	 * activity can keep us busy forever, so we just fail with EBUSY.
831 	 */
832 	if (loopcnt == 0) {
833 		if (oldmnt->mnt_kern_flag & MNTK_UNMOUNT)
834 			panic("softdep_flushfiles: looping");
835 		error = EBUSY;
836 	}
837 	return (error);
838 }
839 
840 /*
841  * Structure hashing.
842  *
843  * There are three types of structures that can be looked up:
844  *	1) pagedep structures identified by mount point, inode number,
845  *	   and logical block.
846  *	2) inodedep structures identified by mount point and inode number.
847  *	3) newblk structures identified by mount point and
848  *	   physical block number.
849  *
850  * The "pagedep" and "inodedep" dependency structures are hashed
851  * separately from the file blocks and inodes to which they correspond.
852  * This separation helps when the in-memory copy of an inode or
853  * file block must be replaced. It also obviates the need to access
854  * an inode or file page when simply updating (or de-allocating)
855  * dependency structures. Lookup of newblk structures is needed to
856  * find newly allocated blocks when trying to associate them with
857  * their allocdirect or allocindir structure.
858  *
859  * The lookup routines optionally create and hash a new instance when
860  * an existing entry is not found.
861  */
862 #define DEPALLOC	0x0001	/* allocate structure if lookup fails */
863 #define NODELAY		0x0002	/* cannot do background work */
864 
865 /*
866  * Structures and routines associated with pagedep caching.
867  */
868 LIST_HEAD(pagedep_hashhead, pagedep) *pagedep_hashtbl;
869 u_long	pagedep_hash;		/* size of hash table - 1 */
870 #define	PAGEDEP_HASH(mp, inum, lbn) \
871 	(&pagedep_hashtbl[((((register_t)(mp)) >> 13) + (inum) + (lbn)) & \
872 	    pagedep_hash])
873 static struct sema pagedep_in_progress;
874 
875 /*
876  * Helper routine for pagedep_lookup()
877  */
878 static __inline
879 struct pagedep *
880 pagedep_find(struct pagedep_hashhead *pagedephd, ino_t ino, ufs_lbn_t lbn,
881 	     struct mount *mp)
882 {
883 	struct pagedep *pagedep;
884 
885 	LIST_FOREACH(pagedep, pagedephd, pd_hash) {
886 		if (ino == pagedep->pd_ino &&
887 		    lbn == pagedep->pd_lbn &&
888 		    mp == pagedep->pd_mnt) {
889 			return (pagedep);
890 		}
891 	}
892 	return(NULL);
893 }
894 
895 /*
896  * Look up a pagedep. Return 1 if found, 0 if not found.
897  * If not found, allocate if DEPALLOC flag is passed.
898  * Found or allocated entry is returned in pagedeppp.
899  * This routine must be called with splbio interrupts blocked.
900  */
901 static int
902 pagedep_lookup(struct inode *ip, ufs_lbn_t lbn, int flags,
903 	       struct pagedep **pagedeppp)
904 {
905 	struct pagedep *pagedep;
906 	struct pagedep_hashhead *pagedephd;
907 	struct mount *mp;
908 	int i;
909 
910 #ifdef DEBUG
911 	if (lk.lkt_held == NOHOLDER)
912 		panic("pagedep_lookup: lock not held");
913 #endif
914 	mp = ITOV(ip)->v_mount;
915 	pagedephd = PAGEDEP_HASH(mp, ip->i_number, lbn);
916 top:
917 	*pagedeppp = pagedep_find(pagedephd, ip->i_number, lbn, mp);
918 	if (*pagedeppp)
919 		return(1);
920 	if ((flags & DEPALLOC) == 0)
921 		return (0);
922 	if (sema_get(&pagedep_in_progress, &lk) == 0) {
923 		ACQUIRE_LOCK(&lk);
924 		goto top;
925 	}
926 	MALLOC(pagedep, struct pagedep *, sizeof(struct pagedep), M_PAGEDEP,
927 		M_SOFTDEP_FLAGS | M_ZERO);
928 
929 	if (pagedep_find(pagedephd, ip->i_number, lbn, mp)) {
930 		kprintf("pagedep_lookup: blocking race avoided\n");
931 		ACQUIRE_LOCK(&lk);
932 		sema_release(&pagedep_in_progress);
933 		kfree(pagedep, M_PAGEDEP);
934 		goto top;
935 	}
936 
937 	pagedep->pd_list.wk_type = D_PAGEDEP;
938 	pagedep->pd_mnt = mp;
939 	pagedep->pd_ino = ip->i_number;
940 	pagedep->pd_lbn = lbn;
941 	LIST_INIT(&pagedep->pd_dirremhd);
942 	LIST_INIT(&pagedep->pd_pendinghd);
943 	for (i = 0; i < DAHASHSZ; i++)
944 		LIST_INIT(&pagedep->pd_diraddhd[i]);
945 	ACQUIRE_LOCK(&lk);
946 	LIST_INSERT_HEAD(pagedephd, pagedep, pd_hash);
947 	sema_release(&pagedep_in_progress);
948 	*pagedeppp = pagedep;
949 	return (0);
950 }
951 
952 /*
953  * Structures and routines associated with inodedep caching.
954  */
955 LIST_HEAD(inodedep_hashhead, inodedep) *inodedep_hashtbl;
956 static u_long	inodedep_hash;	/* size of hash table - 1 */
957 static long	num_inodedep;	/* number of inodedep allocated */
958 #define	INODEDEP_HASH(fs, inum) \
959       (&inodedep_hashtbl[((((register_t)(fs)) >> 13) + (inum)) & inodedep_hash])
960 static struct sema inodedep_in_progress;
961 
962 /*
963  * Helper routine for inodedep_lookup()
964  */
965 static __inline
966 struct inodedep *
967 inodedep_find(struct inodedep_hashhead *inodedephd, struct fs *fs, ino_t inum)
968 {
969 	struct inodedep *inodedep;
970 
971 	LIST_FOREACH(inodedep, inodedephd, id_hash) {
972 		if (inum == inodedep->id_ino && fs == inodedep->id_fs)
973 			return(inodedep);
974 	}
975 	return (NULL);
976 }
977 
978 /*
979  * Look up a inodedep. Return 1 if found, 0 if not found.
980  * If not found, allocate if DEPALLOC flag is passed.
981  * Found or allocated entry is returned in inodedeppp.
982  * This routine must be called with splbio interrupts blocked.
983  */
984 static int
985 inodedep_lookup(struct fs *fs, ino_t inum, int flags,
986 	        struct inodedep **inodedeppp)
987 {
988 	struct inodedep *inodedep;
989 	struct inodedep_hashhead *inodedephd;
990 	int firsttry;
991 
992 #ifdef DEBUG
993 	if (lk.lkt_held == NOHOLDER)
994 		panic("inodedep_lookup: lock not held");
995 #endif
996 	firsttry = 1;
997 	inodedephd = INODEDEP_HASH(fs, inum);
998 top:
999 	*inodedeppp = inodedep_find(inodedephd, fs, inum);
1000 	if (*inodedeppp)
1001 		return (1);
1002 	if ((flags & DEPALLOC) == 0)
1003 		return (0);
1004 	/*
1005 	 * If we are over our limit, try to improve the situation.
1006 	 */
1007 	if (num_inodedep > max_softdeps && firsttry &&
1008 	    speedup_syncer() == 0 && (flags & NODELAY) == 0 &&
1009 	    request_cleanup(FLUSH_INODES, 1)) {
1010 		firsttry = 0;
1011 		goto top;
1012 	}
1013 	if (sema_get(&inodedep_in_progress, &lk) == 0) {
1014 		ACQUIRE_LOCK(&lk);
1015 		goto top;
1016 	}
1017 	MALLOC(inodedep, struct inodedep *, sizeof(struct inodedep),
1018 		M_INODEDEP, M_SOFTDEP_FLAGS | M_ZERO);
1019 	if (inodedep_find(inodedephd, fs, inum)) {
1020 		kprintf("inodedep_lookup: blocking race avoided\n");
1021 		ACQUIRE_LOCK(&lk);
1022 		sema_release(&inodedep_in_progress);
1023 		kfree(inodedep, M_INODEDEP);
1024 		goto top;
1025 	}
1026 	inodedep->id_list.wk_type = D_INODEDEP;
1027 	inodedep->id_fs = fs;
1028 	inodedep->id_ino = inum;
1029 	inodedep->id_state = ALLCOMPLETE;
1030 	inodedep->id_nlinkdelta = 0;
1031 	inodedep->id_savedino = NULL;
1032 	inodedep->id_savedsize = -1;
1033 	inodedep->id_buf = NULL;
1034 	LIST_INIT(&inodedep->id_pendinghd);
1035 	LIST_INIT(&inodedep->id_inowait);
1036 	LIST_INIT(&inodedep->id_bufwait);
1037 	TAILQ_INIT(&inodedep->id_inoupdt);
1038 	TAILQ_INIT(&inodedep->id_newinoupdt);
1039 	ACQUIRE_LOCK(&lk);
1040 	num_inodedep += 1;
1041 	LIST_INSERT_HEAD(inodedephd, inodedep, id_hash);
1042 	sema_release(&inodedep_in_progress);
1043 	*inodedeppp = inodedep;
1044 	return (0);
1045 }
1046 
1047 /*
1048  * Structures and routines associated with newblk caching.
1049  */
1050 LIST_HEAD(newblk_hashhead, newblk) *newblk_hashtbl;
1051 u_long	newblk_hash;		/* size of hash table - 1 */
1052 #define	NEWBLK_HASH(fs, inum) \
1053 	(&newblk_hashtbl[((((register_t)(fs)) >> 13) + (inum)) & newblk_hash])
1054 static struct sema newblk_in_progress;
1055 
1056 /*
1057  * Helper routine for newblk_lookup()
1058  */
1059 static __inline
1060 struct newblk *
1061 newblk_find(struct newblk_hashhead *newblkhd, struct fs *fs,
1062 	    ufs_daddr_t newblkno)
1063 {
1064 	struct newblk *newblk;
1065 
1066 	LIST_FOREACH(newblk, newblkhd, nb_hash) {
1067 		if (newblkno == newblk->nb_newblkno && fs == newblk->nb_fs)
1068 			return (newblk);
1069 	}
1070 	return(NULL);
1071 }
1072 
1073 /*
1074  * Look up a newblk. Return 1 if found, 0 if not found.
1075  * If not found, allocate if DEPALLOC flag is passed.
1076  * Found or allocated entry is returned in newblkpp.
1077  */
1078 static int
1079 newblk_lookup(struct fs *fs, ufs_daddr_t newblkno, int flags,
1080 	      struct newblk **newblkpp)
1081 {
1082 	struct newblk *newblk;
1083 	struct newblk_hashhead *newblkhd;
1084 
1085 	newblkhd = NEWBLK_HASH(fs, newblkno);
1086 top:
1087 	*newblkpp = newblk_find(newblkhd, fs, newblkno);
1088 	if (*newblkpp)
1089 		return(1);
1090 	if ((flags & DEPALLOC) == 0)
1091 		return (0);
1092 	if (sema_get(&newblk_in_progress, 0) == 0)
1093 		goto top;
1094 	MALLOC(newblk, struct newblk *, sizeof(struct newblk),
1095 		M_NEWBLK, M_SOFTDEP_FLAGS | M_ZERO);
1096 
1097 	if (newblk_find(newblkhd, fs, newblkno)) {
1098 		kprintf("newblk_lookup: blocking race avoided\n");
1099 		sema_release(&pagedep_in_progress);
1100 		kfree(newblk, M_NEWBLK);
1101 		goto top;
1102 	}
1103 	newblk->nb_state = 0;
1104 	newblk->nb_fs = fs;
1105 	newblk->nb_newblkno = newblkno;
1106 	LIST_INSERT_HEAD(newblkhd, newblk, nb_hash);
1107 	sema_release(&newblk_in_progress);
1108 	*newblkpp = newblk;
1109 	return (0);
1110 }
1111 
1112 /*
1113  * Executed during filesystem system initialization before
1114  * mounting any filesystems.
1115  */
1116 void
1117 softdep_initialize(void)
1118 {
1119 	callout_init(&handle);
1120 
1121 	LIST_INIT(&mkdirlisthd);
1122 	LIST_INIT(&softdep_workitem_pending);
1123 	max_softdeps = min(desiredvnodes * 8,
1124 		M_INODEDEP->ks_limit / (2 * sizeof(struct inodedep)));
1125 	pagedep_hashtbl = hashinit(desiredvnodes / 5, M_PAGEDEP,
1126 	    &pagedep_hash);
1127 	sema_init(&pagedep_in_progress, "pagedep", 0, 0);
1128 	inodedep_hashtbl = hashinit(desiredvnodes, M_INODEDEP, &inodedep_hash);
1129 	sema_init(&inodedep_in_progress, "inodedep", 0, 0);
1130 	newblk_hashtbl = hashinit(64, M_NEWBLK, &newblk_hash);
1131 	sema_init(&newblk_in_progress, "newblk", 0, 0);
1132 	add_bio_ops(&softdep_bioops);
1133 }
1134 
1135 /*
1136  * Called at mount time to notify the dependency code that a
1137  * filesystem wishes to use it.
1138  */
1139 int
1140 softdep_mount(struct vnode *devvp, struct mount *mp, struct fs *fs)
1141 {
1142 	struct csum cstotal;
1143 	struct cg *cgp;
1144 	struct buf *bp;
1145 	int error, cyl;
1146 
1147 	mp->mnt_flag &= ~MNT_ASYNC;
1148 	mp->mnt_flag |= MNT_SOFTDEP;
1149 	mp->mnt_bioops = &softdep_bioops;
1150 	/*
1151 	 * When doing soft updates, the counters in the
1152 	 * superblock may have gotten out of sync, so we have
1153 	 * to scan the cylinder groups and recalculate them.
1154 	 */
1155 	if (fs->fs_clean != 0)
1156 		return (0);
1157 	bzero(&cstotal, sizeof cstotal);
1158 	for (cyl = 0; cyl < fs->fs_ncg; cyl++) {
1159 		if ((error = bread(devvp, fsbtodoff(fs, cgtod(fs, cyl)),
1160 				   fs->fs_cgsize, &bp)) != 0) {
1161 			brelse(bp);
1162 			return (error);
1163 		}
1164 		cgp = (struct cg *)bp->b_data;
1165 		cstotal.cs_nffree += cgp->cg_cs.cs_nffree;
1166 		cstotal.cs_nbfree += cgp->cg_cs.cs_nbfree;
1167 		cstotal.cs_nifree += cgp->cg_cs.cs_nifree;
1168 		cstotal.cs_ndir += cgp->cg_cs.cs_ndir;
1169 		fs->fs_cs(fs, cyl) = cgp->cg_cs;
1170 		brelse(bp);
1171 	}
1172 #ifdef DEBUG
1173 	if (bcmp(&cstotal, &fs->fs_cstotal, sizeof cstotal))
1174 		kprintf("ffs_mountfs: superblock updated for soft updates\n");
1175 #endif
1176 	bcopy(&cstotal, &fs->fs_cstotal, sizeof cstotal);
1177 	return (0);
1178 }
1179 
1180 /*
1181  * Protecting the freemaps (or bitmaps).
1182  *
1183  * To eliminate the need to execute fsck before mounting a filesystem
1184  * after a power failure, one must (conservatively) guarantee that the
1185  * on-disk copy of the bitmaps never indicate that a live inode or block is
1186  * free.  So, when a block or inode is allocated, the bitmap should be
1187  * updated (on disk) before any new pointers.  When a block or inode is
1188  * freed, the bitmap should not be updated until all pointers have been
1189  * reset.  The latter dependency is handled by the delayed de-allocation
1190  * approach described below for block and inode de-allocation.  The former
1191  * dependency is handled by calling the following procedure when a block or
1192  * inode is allocated. When an inode is allocated an "inodedep" is created
1193  * with its DEPCOMPLETE flag cleared until its bitmap is written to disk.
1194  * Each "inodedep" is also inserted into the hash indexing structure so
1195  * that any additional link additions can be made dependent on the inode
1196  * allocation.
1197  *
1198  * The ufs filesystem maintains a number of free block counts (e.g., per
1199  * cylinder group, per cylinder and per <cylinder, rotational position> pair)
1200  * in addition to the bitmaps.  These counts are used to improve efficiency
1201  * during allocation and therefore must be consistent with the bitmaps.
1202  * There is no convenient way to guarantee post-crash consistency of these
1203  * counts with simple update ordering, for two main reasons: (1) The counts
1204  * and bitmaps for a single cylinder group block are not in the same disk
1205  * sector.  If a disk write is interrupted (e.g., by power failure), one may
1206  * be written and the other not.  (2) Some of the counts are located in the
1207  * superblock rather than the cylinder group block. So, we focus our soft
1208  * updates implementation on protecting the bitmaps. When mounting a
1209  * filesystem, we recompute the auxiliary counts from the bitmaps.
1210  */
1211 
1212 /*
1213  * Called just after updating the cylinder group block to allocate an inode.
1214  *
1215  * Parameters:
1216  *	bp:		buffer for cylgroup block with inode map
1217  *	ip:		inode related to allocation
1218  *	newinum:	new inode number being allocated
1219  */
1220 void
1221 softdep_setup_inomapdep(struct buf *bp, struct inode *ip, ino_t newinum)
1222 {
1223 	struct inodedep *inodedep;
1224 	struct bmsafemap *bmsafemap;
1225 
1226 	/*
1227 	 * Create a dependency for the newly allocated inode.
1228 	 * Panic if it already exists as something is seriously wrong.
1229 	 * Otherwise add it to the dependency list for the buffer holding
1230 	 * the cylinder group map from which it was allocated.
1231 	 */
1232 	ACQUIRE_LOCK(&lk);
1233 	if ((inodedep_lookup(ip->i_fs, newinum, DEPALLOC|NODELAY, &inodedep))) {
1234 		FREE_LOCK(&lk);
1235 		panic("softdep_setup_inomapdep: found inode");
1236 	}
1237 	inodedep->id_buf = bp;
1238 	inodedep->id_state &= ~DEPCOMPLETE;
1239 	bmsafemap = bmsafemap_lookup(bp);
1240 	LIST_INSERT_HEAD(&bmsafemap->sm_inodedephd, inodedep, id_deps);
1241 	FREE_LOCK(&lk);
1242 }
1243 
1244 /*
1245  * Called just after updating the cylinder group block to
1246  * allocate block or fragment.
1247  *
1248  * Parameters:
1249  *	bp:		buffer for cylgroup block with block map
1250  *	fs:		filesystem doing allocation
1251  *	newblkno:	number of newly allocated block
1252  */
1253 void
1254 softdep_setup_blkmapdep(struct buf *bp, struct fs *fs,
1255 			ufs_daddr_t newblkno)
1256 {
1257 	struct newblk *newblk;
1258 	struct bmsafemap *bmsafemap;
1259 
1260 	/*
1261 	 * Create a dependency for the newly allocated block.
1262 	 * Add it to the dependency list for the buffer holding
1263 	 * the cylinder group map from which it was allocated.
1264 	 */
1265 	if (newblk_lookup(fs, newblkno, DEPALLOC, &newblk) != 0)
1266 		panic("softdep_setup_blkmapdep: found block");
1267 	ACQUIRE_LOCK(&lk);
1268 	newblk->nb_bmsafemap = bmsafemap = bmsafemap_lookup(bp);
1269 	LIST_INSERT_HEAD(&bmsafemap->sm_newblkhd, newblk, nb_deps);
1270 	FREE_LOCK(&lk);
1271 }
1272 
1273 /*
1274  * Find the bmsafemap associated with a cylinder group buffer.
1275  * If none exists, create one. The buffer must be locked when
1276  * this routine is called and this routine must be called with
1277  * splbio interrupts blocked.
1278  */
1279 static struct bmsafemap *
1280 bmsafemap_lookup(struct buf *bp)
1281 {
1282 	struct bmsafemap *bmsafemap;
1283 	struct worklist *wk;
1284 
1285 #ifdef DEBUG
1286 	if (lk.lkt_held == NOHOLDER)
1287 		panic("bmsafemap_lookup: lock not held");
1288 #endif
1289 	LIST_FOREACH(wk, &bp->b_dep, wk_list) {
1290 		if (wk->wk_type == D_BMSAFEMAP)
1291 			return (WK_BMSAFEMAP(wk));
1292 	}
1293 	FREE_LOCK(&lk);
1294 	MALLOC(bmsafemap, struct bmsafemap *, sizeof(struct bmsafemap),
1295 		M_BMSAFEMAP, M_SOFTDEP_FLAGS);
1296 	bmsafemap->sm_list.wk_type = D_BMSAFEMAP;
1297 	bmsafemap->sm_list.wk_state = 0;
1298 	bmsafemap->sm_buf = bp;
1299 	LIST_INIT(&bmsafemap->sm_allocdirecthd);
1300 	LIST_INIT(&bmsafemap->sm_allocindirhd);
1301 	LIST_INIT(&bmsafemap->sm_inodedephd);
1302 	LIST_INIT(&bmsafemap->sm_newblkhd);
1303 	ACQUIRE_LOCK(&lk);
1304 	WORKLIST_INSERT_BP(bp, &bmsafemap->sm_list);
1305 	return (bmsafemap);
1306 }
1307 
1308 /*
1309  * Direct block allocation dependencies.
1310  *
1311  * When a new block is allocated, the corresponding disk locations must be
1312  * initialized (with zeros or new data) before the on-disk inode points to
1313  * them.  Also, the freemap from which the block was allocated must be
1314  * updated (on disk) before the inode's pointer. These two dependencies are
1315  * independent of each other and are needed for all file blocks and indirect
1316  * blocks that are pointed to directly by the inode.  Just before the
1317  * "in-core" version of the inode is updated with a newly allocated block
1318  * number, a procedure (below) is called to setup allocation dependency
1319  * structures.  These structures are removed when the corresponding
1320  * dependencies are satisfied or when the block allocation becomes obsolete
1321  * (i.e., the file is deleted, the block is de-allocated, or the block is a
1322  * fragment that gets upgraded).  All of these cases are handled in
1323  * procedures described later.
1324  *
1325  * When a file extension causes a fragment to be upgraded, either to a larger
1326  * fragment or to a full block, the on-disk location may change (if the
1327  * previous fragment could not simply be extended). In this case, the old
1328  * fragment must be de-allocated, but not until after the inode's pointer has
1329  * been updated. In most cases, this is handled by later procedures, which
1330  * will construct a "freefrag" structure to be added to the workitem queue
1331  * when the inode update is complete (or obsolete).  The main exception to
1332  * this is when an allocation occurs while a pending allocation dependency
1333  * (for the same block pointer) remains.  This case is handled in the main
1334  * allocation dependency setup procedure by immediately freeing the
1335  * unreferenced fragments.
1336  *
1337  * Parameters:
1338  *	ip:		inode to which block is being added
1339  *	lbn:		block pointer within inode
1340  *	newblkno:	disk block number being added
1341  *	oldblkno:	previous block number, 0 unless frag
1342  *	newsize:	size of new block
1343  *	oldsize:	size of new block
1344  *	bp:		bp for allocated block
1345  */
1346 void
1347 softdep_setup_allocdirect(struct inode *ip, ufs_lbn_t lbn, ufs_daddr_t newblkno,
1348 			  ufs_daddr_t oldblkno, long newsize, long oldsize,
1349 			  struct buf *bp)
1350 {
1351 	struct allocdirect *adp, *oldadp;
1352 	struct allocdirectlst *adphead;
1353 	struct bmsafemap *bmsafemap;
1354 	struct inodedep *inodedep;
1355 	struct pagedep *pagedep;
1356 	struct newblk *newblk;
1357 
1358 	MALLOC(adp, struct allocdirect *, sizeof(struct allocdirect),
1359 		M_ALLOCDIRECT, M_SOFTDEP_FLAGS | M_ZERO);
1360 	adp->ad_list.wk_type = D_ALLOCDIRECT;
1361 	adp->ad_lbn = lbn;
1362 	adp->ad_newblkno = newblkno;
1363 	adp->ad_oldblkno = oldblkno;
1364 	adp->ad_newsize = newsize;
1365 	adp->ad_oldsize = oldsize;
1366 	adp->ad_state = ATTACHED;
1367 	if (newblkno == oldblkno)
1368 		adp->ad_freefrag = NULL;
1369 	else
1370 		adp->ad_freefrag = newfreefrag(ip, oldblkno, oldsize);
1371 
1372 	if (newblk_lookup(ip->i_fs, newblkno, 0, &newblk) == 0)
1373 		panic("softdep_setup_allocdirect: lost block");
1374 
1375 	ACQUIRE_LOCK(&lk);
1376 	inodedep_lookup(ip->i_fs, ip->i_number, DEPALLOC | NODELAY, &inodedep);
1377 	adp->ad_inodedep = inodedep;
1378 
1379 	if (newblk->nb_state == DEPCOMPLETE) {
1380 		adp->ad_state |= DEPCOMPLETE;
1381 		adp->ad_buf = NULL;
1382 	} else {
1383 		bmsafemap = newblk->nb_bmsafemap;
1384 		adp->ad_buf = bmsafemap->sm_buf;
1385 		LIST_REMOVE(newblk, nb_deps);
1386 		LIST_INSERT_HEAD(&bmsafemap->sm_allocdirecthd, adp, ad_deps);
1387 	}
1388 	LIST_REMOVE(newblk, nb_hash);
1389 	FREE(newblk, M_NEWBLK);
1390 
1391 	WORKLIST_INSERT_BP(bp, &adp->ad_list);
1392 	if (lbn >= NDADDR) {
1393 		/* allocating an indirect block */
1394 		if (oldblkno != 0) {
1395 			FREE_LOCK(&lk);
1396 			panic("softdep_setup_allocdirect: non-zero indir");
1397 		}
1398 	} else {
1399 		/*
1400 		 * Allocating a direct block.
1401 		 *
1402 		 * If we are allocating a directory block, then we must
1403 		 * allocate an associated pagedep to track additions and
1404 		 * deletions.
1405 		 */
1406 		if ((ip->i_mode & IFMT) == IFDIR &&
1407 		    pagedep_lookup(ip, lbn, DEPALLOC, &pagedep) == 0) {
1408 			WORKLIST_INSERT_BP(bp, &pagedep->pd_list);
1409 		}
1410 	}
1411 	/*
1412 	 * The list of allocdirects must be kept in sorted and ascending
1413 	 * order so that the rollback routines can quickly determine the
1414 	 * first uncommitted block (the size of the file stored on disk
1415 	 * ends at the end of the lowest committed fragment, or if there
1416 	 * are no fragments, at the end of the highest committed block).
1417 	 * Since files generally grow, the typical case is that the new
1418 	 * block is to be added at the end of the list. We speed this
1419 	 * special case by checking against the last allocdirect in the
1420 	 * list before laboriously traversing the list looking for the
1421 	 * insertion point.
1422 	 */
1423 	adphead = &inodedep->id_newinoupdt;
1424 	oldadp = TAILQ_LAST(adphead, allocdirectlst);
1425 	if (oldadp == NULL || oldadp->ad_lbn <= lbn) {
1426 		/* insert at end of list */
1427 		TAILQ_INSERT_TAIL(adphead, adp, ad_next);
1428 		if (oldadp != NULL && oldadp->ad_lbn == lbn)
1429 			allocdirect_merge(adphead, adp, oldadp);
1430 		FREE_LOCK(&lk);
1431 		return;
1432 	}
1433 	TAILQ_FOREACH(oldadp, adphead, ad_next) {
1434 		if (oldadp->ad_lbn >= lbn)
1435 			break;
1436 	}
1437 	if (oldadp == NULL) {
1438 		FREE_LOCK(&lk);
1439 		panic("softdep_setup_allocdirect: lost entry");
1440 	}
1441 	/* insert in middle of list */
1442 	TAILQ_INSERT_BEFORE(oldadp, adp, ad_next);
1443 	if (oldadp->ad_lbn == lbn)
1444 		allocdirect_merge(adphead, adp, oldadp);
1445 	FREE_LOCK(&lk);
1446 }
1447 
1448 /*
1449  * Replace an old allocdirect dependency with a newer one.
1450  * This routine must be called with splbio interrupts blocked.
1451  *
1452  * Parameters:
1453  *	adphead:	head of list holding allocdirects
1454  *	newadp:		allocdirect being added
1455  *	oldadp:		existing allocdirect being checked
1456  */
1457 static void
1458 allocdirect_merge(struct allocdirectlst *adphead,
1459 		  struct allocdirect *newadp,
1460 		  struct allocdirect *oldadp)
1461 {
1462 	struct freefrag *freefrag;
1463 
1464 #ifdef DEBUG
1465 	if (lk.lkt_held == NOHOLDER)
1466 		panic("allocdirect_merge: lock not held");
1467 #endif
1468 	if (newadp->ad_oldblkno != oldadp->ad_newblkno ||
1469 	    newadp->ad_oldsize != oldadp->ad_newsize ||
1470 	    newadp->ad_lbn >= NDADDR) {
1471 		FREE_LOCK(&lk);
1472 		panic("allocdirect_check: old %d != new %d || lbn %ld >= %d",
1473 		    newadp->ad_oldblkno, oldadp->ad_newblkno, newadp->ad_lbn,
1474 		    NDADDR);
1475 	}
1476 	newadp->ad_oldblkno = oldadp->ad_oldblkno;
1477 	newadp->ad_oldsize = oldadp->ad_oldsize;
1478 	/*
1479 	 * If the old dependency had a fragment to free or had never
1480 	 * previously had a block allocated, then the new dependency
1481 	 * can immediately post its freefrag and adopt the old freefrag.
1482 	 * This action is done by swapping the freefrag dependencies.
1483 	 * The new dependency gains the old one's freefrag, and the
1484 	 * old one gets the new one and then immediately puts it on
1485 	 * the worklist when it is freed by free_allocdirect. It is
1486 	 * not possible to do this swap when the old dependency had a
1487 	 * non-zero size but no previous fragment to free. This condition
1488 	 * arises when the new block is an extension of the old block.
1489 	 * Here, the first part of the fragment allocated to the new
1490 	 * dependency is part of the block currently claimed on disk by
1491 	 * the old dependency, so cannot legitimately be freed until the
1492 	 * conditions for the new dependency are fulfilled.
1493 	 */
1494 	if (oldadp->ad_freefrag != NULL || oldadp->ad_oldblkno == 0) {
1495 		freefrag = newadp->ad_freefrag;
1496 		newadp->ad_freefrag = oldadp->ad_freefrag;
1497 		oldadp->ad_freefrag = freefrag;
1498 	}
1499 	free_allocdirect(adphead, oldadp, 0);
1500 }
1501 
1502 /*
1503  * Allocate a new freefrag structure if needed.
1504  */
1505 static struct freefrag *
1506 newfreefrag(struct inode *ip, ufs_daddr_t blkno, long size)
1507 {
1508 	struct freefrag *freefrag;
1509 	struct fs *fs;
1510 
1511 	if (blkno == 0)
1512 		return (NULL);
1513 	fs = ip->i_fs;
1514 	if (fragnum(fs, blkno) + numfrags(fs, size) > fs->fs_frag)
1515 		panic("newfreefrag: frag size");
1516 	MALLOC(freefrag, struct freefrag *, sizeof(struct freefrag),
1517 		M_FREEFRAG, M_SOFTDEP_FLAGS);
1518 	freefrag->ff_list.wk_type = D_FREEFRAG;
1519 	freefrag->ff_state = ip->i_uid & ~ONWORKLIST;	/* XXX - used below */
1520 	freefrag->ff_inum = ip->i_number;
1521 	freefrag->ff_fs = fs;
1522 	freefrag->ff_devvp = ip->i_devvp;
1523 	freefrag->ff_blkno = blkno;
1524 	freefrag->ff_fragsize = size;
1525 	return (freefrag);
1526 }
1527 
1528 /*
1529  * This workitem de-allocates fragments that were replaced during
1530  * file block allocation.
1531  */
1532 static void
1533 handle_workitem_freefrag(struct freefrag *freefrag)
1534 {
1535 	struct inode tip;
1536 
1537 	tip.i_fs = freefrag->ff_fs;
1538 	tip.i_devvp = freefrag->ff_devvp;
1539 	tip.i_dev = freefrag->ff_devvp->v_rdev;
1540 	tip.i_number = freefrag->ff_inum;
1541 	tip.i_uid = freefrag->ff_state & ~ONWORKLIST;	/* XXX - set above */
1542 	ffs_blkfree(&tip, freefrag->ff_blkno, freefrag->ff_fragsize);
1543 	FREE(freefrag, M_FREEFRAG);
1544 }
1545 
1546 /*
1547  * Indirect block allocation dependencies.
1548  *
1549  * The same dependencies that exist for a direct block also exist when
1550  * a new block is allocated and pointed to by an entry in a block of
1551  * indirect pointers. The undo/redo states described above are also
1552  * used here. Because an indirect block contains many pointers that
1553  * may have dependencies, a second copy of the entire in-memory indirect
1554  * block is kept. The buffer cache copy is always completely up-to-date.
1555  * The second copy, which is used only as a source for disk writes,
1556  * contains only the safe pointers (i.e., those that have no remaining
1557  * update dependencies). The second copy is freed when all pointers
1558  * are safe. The cache is not allowed to replace indirect blocks with
1559  * pending update dependencies. If a buffer containing an indirect
1560  * block with dependencies is written, these routines will mark it
1561  * dirty again. It can only be successfully written once all the
1562  * dependencies are removed. The ffs_fsync routine in conjunction with
1563  * softdep_sync_metadata work together to get all the dependencies
1564  * removed so that a file can be successfully written to disk. Three
1565  * procedures are used when setting up indirect block pointer
1566  * dependencies. The division is necessary because of the organization
1567  * of the "balloc" routine and because of the distinction between file
1568  * pages and file metadata blocks.
1569  */
1570 
1571 /*
1572  * Allocate a new allocindir structure.
1573  *
1574  * Parameters:
1575  *	ip:		inode for file being extended
1576  *	ptrno:		offset of pointer in indirect block
1577  *	newblkno:	disk block number being added
1578  *	oldblkno:	previous block number, 0 if none
1579  */
1580 static struct allocindir *
1581 newallocindir(struct inode *ip, int ptrno, ufs_daddr_t newblkno,
1582 	      ufs_daddr_t oldblkno)
1583 {
1584 	struct allocindir *aip;
1585 
1586 	MALLOC(aip, struct allocindir *, sizeof(struct allocindir),
1587 		M_ALLOCINDIR, M_SOFTDEP_FLAGS | M_ZERO);
1588 	aip->ai_list.wk_type = D_ALLOCINDIR;
1589 	aip->ai_state = ATTACHED;
1590 	aip->ai_offset = ptrno;
1591 	aip->ai_newblkno = newblkno;
1592 	aip->ai_oldblkno = oldblkno;
1593 	aip->ai_freefrag = newfreefrag(ip, oldblkno, ip->i_fs->fs_bsize);
1594 	return (aip);
1595 }
1596 
1597 /*
1598  * Called just before setting an indirect block pointer
1599  * to a newly allocated file page.
1600  *
1601  * Parameters:
1602  *	ip:		inode for file being extended
1603  *	lbn:		allocated block number within file
1604  *	bp:		buffer with indirect blk referencing page
1605  *	ptrno:		offset of pointer in indirect block
1606  *	newblkno:	disk block number being added
1607  *	oldblkno:	previous block number, 0 if none
1608  *	nbp:		buffer holding allocated page
1609  */
1610 void
1611 softdep_setup_allocindir_page(struct inode *ip, ufs_lbn_t lbn,
1612 			      struct buf *bp, int ptrno,
1613 			      ufs_daddr_t newblkno, ufs_daddr_t oldblkno,
1614 			      struct buf *nbp)
1615 {
1616 	struct allocindir *aip;
1617 	struct pagedep *pagedep;
1618 
1619 	aip = newallocindir(ip, ptrno, newblkno, oldblkno);
1620 	ACQUIRE_LOCK(&lk);
1621 	/*
1622 	 * If we are allocating a directory page, then we must
1623 	 * allocate an associated pagedep to track additions and
1624 	 * deletions.
1625 	 */
1626 	if ((ip->i_mode & IFMT) == IFDIR &&
1627 	    pagedep_lookup(ip, lbn, DEPALLOC, &pagedep) == 0)
1628 		WORKLIST_INSERT_BP(nbp, &pagedep->pd_list);
1629 	WORKLIST_INSERT_BP(nbp, &aip->ai_list);
1630 	FREE_LOCK(&lk);
1631 	setup_allocindir_phase2(bp, ip, aip);
1632 }
1633 
1634 /*
1635  * Called just before setting an indirect block pointer to a
1636  * newly allocated indirect block.
1637  * Parameters:
1638  *	nbp:		newly allocated indirect block
1639  *	ip:		inode for file being extended
1640  *	bp:		indirect block referencing allocated block
1641  *	ptrno:		offset of pointer in indirect block
1642  *	newblkno:	disk block number being added
1643  */
1644 void
1645 softdep_setup_allocindir_meta(struct buf *nbp, struct inode *ip,
1646 			      struct buf *bp, int ptrno,
1647 			      ufs_daddr_t newblkno)
1648 {
1649 	struct allocindir *aip;
1650 
1651 	aip = newallocindir(ip, ptrno, newblkno, 0);
1652 	ACQUIRE_LOCK(&lk);
1653 	WORKLIST_INSERT_BP(nbp, &aip->ai_list);
1654 	FREE_LOCK(&lk);
1655 	setup_allocindir_phase2(bp, ip, aip);
1656 }
1657 
1658 /*
1659  * Called to finish the allocation of the "aip" allocated
1660  * by one of the two routines above.
1661  *
1662  * Parameters:
1663  *	bp:	in-memory copy of the indirect block
1664  *	ip:	inode for file being extended
1665  *	aip:	allocindir allocated by the above routines
1666  */
1667 static void
1668 setup_allocindir_phase2(struct buf *bp, struct inode *ip,
1669 			struct allocindir *aip)
1670 {
1671 	struct worklist *wk;
1672 	struct indirdep *indirdep, *newindirdep;
1673 	struct bmsafemap *bmsafemap;
1674 	struct allocindir *oldaip;
1675 	struct freefrag *freefrag;
1676 	struct newblk *newblk;
1677 
1678 	if (bp->b_loffset >= 0)
1679 		panic("setup_allocindir_phase2: not indir blk");
1680 	for (indirdep = NULL, newindirdep = NULL; ; ) {
1681 		ACQUIRE_LOCK(&lk);
1682 		LIST_FOREACH(wk, &bp->b_dep, wk_list) {
1683 			if (wk->wk_type != D_INDIRDEP)
1684 				continue;
1685 			indirdep = WK_INDIRDEP(wk);
1686 			break;
1687 		}
1688 		if (indirdep == NULL && newindirdep) {
1689 			indirdep = newindirdep;
1690 			WORKLIST_INSERT_BP(bp, &indirdep->ir_list);
1691 			newindirdep = NULL;
1692 		}
1693 		FREE_LOCK(&lk);
1694 		if (indirdep) {
1695 			if (newblk_lookup(ip->i_fs, aip->ai_newblkno, 0,
1696 			    &newblk) == 0)
1697 				panic("setup_allocindir: lost block");
1698 			ACQUIRE_LOCK(&lk);
1699 			if (newblk->nb_state == DEPCOMPLETE) {
1700 				aip->ai_state |= DEPCOMPLETE;
1701 				aip->ai_buf = NULL;
1702 			} else {
1703 				bmsafemap = newblk->nb_bmsafemap;
1704 				aip->ai_buf = bmsafemap->sm_buf;
1705 				LIST_REMOVE(newblk, nb_deps);
1706 				LIST_INSERT_HEAD(&bmsafemap->sm_allocindirhd,
1707 				    aip, ai_deps);
1708 			}
1709 			LIST_REMOVE(newblk, nb_hash);
1710 			FREE(newblk, M_NEWBLK);
1711 			aip->ai_indirdep = indirdep;
1712 			/*
1713 			 * Check to see if there is an existing dependency
1714 			 * for this block. If there is, merge the old
1715 			 * dependency into the new one.
1716 			 */
1717 			if (aip->ai_oldblkno == 0)
1718 				oldaip = NULL;
1719 			else
1720 
1721 				LIST_FOREACH(oldaip, &indirdep->ir_deplisthd, ai_next)
1722 					if (oldaip->ai_offset == aip->ai_offset)
1723 						break;
1724 			if (oldaip != NULL) {
1725 				if (oldaip->ai_newblkno != aip->ai_oldblkno) {
1726 					FREE_LOCK(&lk);
1727 					panic("setup_allocindir_phase2: blkno");
1728 				}
1729 				aip->ai_oldblkno = oldaip->ai_oldblkno;
1730 				freefrag = oldaip->ai_freefrag;
1731 				oldaip->ai_freefrag = aip->ai_freefrag;
1732 				aip->ai_freefrag = freefrag;
1733 				free_allocindir(oldaip, NULL);
1734 			}
1735 			LIST_INSERT_HEAD(&indirdep->ir_deplisthd, aip, ai_next);
1736 			((ufs_daddr_t *)indirdep->ir_savebp->b_data)
1737 			    [aip->ai_offset] = aip->ai_oldblkno;
1738 			FREE_LOCK(&lk);
1739 		}
1740 		if (newindirdep) {
1741 			/*
1742 			 * Avoid any possibility of data corruption by
1743 			 * ensuring that our old version is thrown away.
1744 			 */
1745 			newindirdep->ir_savebp->b_flags |= B_INVAL | B_NOCACHE;
1746 			brelse(newindirdep->ir_savebp);
1747 			WORKITEM_FREE((caddr_t)newindirdep, D_INDIRDEP);
1748 		}
1749 		if (indirdep)
1750 			break;
1751 		MALLOC(newindirdep, struct indirdep *, sizeof(struct indirdep),
1752 			M_INDIRDEP, M_SOFTDEP_FLAGS);
1753 		newindirdep->ir_list.wk_type = D_INDIRDEP;
1754 		newindirdep->ir_state = ATTACHED;
1755 		LIST_INIT(&newindirdep->ir_deplisthd);
1756 		LIST_INIT(&newindirdep->ir_donehd);
1757 		if (bp->b_bio2.bio_offset == NOOFFSET) {
1758 			VOP_BMAP(bp->b_vp, bp->b_bio1.bio_offset,
1759 				 &bp->b_bio2.bio_offset, NULL, NULL,
1760 				 BUF_CMD_WRITE);
1761 		}
1762 		KKASSERT(bp->b_bio2.bio_offset != NOOFFSET);
1763 		newindirdep->ir_savebp = getblk(ip->i_devvp,
1764 						bp->b_bio2.bio_offset,
1765 					        bp->b_bcount, 0, 0);
1766 		BUF_KERNPROC(newindirdep->ir_savebp);
1767 		bcopy(bp->b_data, newindirdep->ir_savebp->b_data, bp->b_bcount);
1768 	}
1769 }
1770 
1771 /*
1772  * Block de-allocation dependencies.
1773  *
1774  * When blocks are de-allocated, the on-disk pointers must be nullified before
1775  * the blocks are made available for use by other files.  (The true
1776  * requirement is that old pointers must be nullified before new on-disk
1777  * pointers are set.  We chose this slightly more stringent requirement to
1778  * reduce complexity.) Our implementation handles this dependency by updating
1779  * the inode (or indirect block) appropriately but delaying the actual block
1780  * de-allocation (i.e., freemap and free space count manipulation) until
1781  * after the updated versions reach stable storage.  After the disk is
1782  * updated, the blocks can be safely de-allocated whenever it is convenient.
1783  * This implementation handles only the common case of reducing a file's
1784  * length to zero. Other cases are handled by the conventional synchronous
1785  * write approach.
1786  *
1787  * The ffs implementation with which we worked double-checks
1788  * the state of the block pointers and file size as it reduces
1789  * a file's length.  Some of this code is replicated here in our
1790  * soft updates implementation.  The freeblks->fb_chkcnt field is
1791  * used to transfer a part of this information to the procedure
1792  * that eventually de-allocates the blocks.
1793  *
1794  * This routine should be called from the routine that shortens
1795  * a file's length, before the inode's size or block pointers
1796  * are modified. It will save the block pointer information for
1797  * later release and zero the inode so that the calling routine
1798  * can release it.
1799  */
1800 struct softdep_setup_freeblocks_info {
1801 	struct fs *fs;
1802 	struct inode *ip;
1803 };
1804 
1805 static int softdep_setup_freeblocks_bp(struct buf *bp, void *data);
1806 
1807 /*
1808  * Parameters:
1809  *	ip:	The inode whose length is to be reduced
1810  *	length:	The new length for the file
1811  */
1812 void
1813 softdep_setup_freeblocks(struct inode *ip, off_t length)
1814 {
1815 	struct softdep_setup_freeblocks_info info;
1816 	struct freeblks *freeblks;
1817 	struct inodedep *inodedep;
1818 	struct allocdirect *adp;
1819 	struct vnode *vp;
1820 	struct buf *bp;
1821 	struct fs *fs;
1822 	int i, error, delay;
1823 	int count;
1824 
1825 	fs = ip->i_fs;
1826 	if (length != 0)
1827 		panic("softde_setup_freeblocks: non-zero length");
1828 	MALLOC(freeblks, struct freeblks *, sizeof(struct freeblks),
1829 		M_FREEBLKS, M_SOFTDEP_FLAGS | M_ZERO);
1830 	freeblks->fb_list.wk_type = D_FREEBLKS;
1831 	freeblks->fb_state = ATTACHED;
1832 	freeblks->fb_uid = ip->i_uid;
1833 	freeblks->fb_previousinum = ip->i_number;
1834 	freeblks->fb_devvp = ip->i_devvp;
1835 	freeblks->fb_fs = fs;
1836 	freeblks->fb_oldsize = ip->i_size;
1837 	freeblks->fb_newsize = length;
1838 	freeblks->fb_chkcnt = ip->i_blocks;
1839 	for (i = 0; i < NDADDR; i++) {
1840 		freeblks->fb_dblks[i] = ip->i_db[i];
1841 		ip->i_db[i] = 0;
1842 	}
1843 	for (i = 0; i < NIADDR; i++) {
1844 		freeblks->fb_iblks[i] = ip->i_ib[i];
1845 		ip->i_ib[i] = 0;
1846 	}
1847 	ip->i_blocks = 0;
1848 	ip->i_size = 0;
1849 	/*
1850 	 * Push the zero'ed inode to to its disk buffer so that we are free
1851 	 * to delete its dependencies below. Once the dependencies are gone
1852 	 * the buffer can be safely released.
1853 	 */
1854 	if ((error = bread(ip->i_devvp,
1855 			    fsbtodoff(fs, ino_to_fsba(fs, ip->i_number)),
1856 	    (int)fs->fs_bsize, &bp)) != 0)
1857 		softdep_error("softdep_setup_freeblocks", error);
1858 	*((struct ufs1_dinode *)bp->b_data + ino_to_fsbo(fs, ip->i_number)) =
1859 	    ip->i_din;
1860 	/*
1861 	 * Find and eliminate any inode dependencies.
1862 	 */
1863 	ACQUIRE_LOCK(&lk);
1864 	(void) inodedep_lookup(fs, ip->i_number, DEPALLOC, &inodedep);
1865 	if ((inodedep->id_state & IOSTARTED) != 0) {
1866 		FREE_LOCK(&lk);
1867 		panic("softdep_setup_freeblocks: inode busy");
1868 	}
1869 	/*
1870 	 * Add the freeblks structure to the list of operations that
1871 	 * must await the zero'ed inode being written to disk. If we
1872 	 * still have a bitmap dependency (delay == 0), then the inode
1873 	 * has never been written to disk, so we can process the
1874 	 * freeblks below once we have deleted the dependencies.
1875 	 */
1876 	delay = (inodedep->id_state & DEPCOMPLETE);
1877 	if (delay)
1878 		WORKLIST_INSERT(&inodedep->id_bufwait, &freeblks->fb_list);
1879 	/*
1880 	 * Because the file length has been truncated to zero, any
1881 	 * pending block allocation dependency structures associated
1882 	 * with this inode are obsolete and can simply be de-allocated.
1883 	 * We must first merge the two dependency lists to get rid of
1884 	 * any duplicate freefrag structures, then purge the merged list.
1885 	 */
1886 	merge_inode_lists(inodedep);
1887 	while ((adp = TAILQ_FIRST(&inodedep->id_inoupdt)) != 0)
1888 		free_allocdirect(&inodedep->id_inoupdt, adp, 1);
1889 	FREE_LOCK(&lk);
1890 	bdwrite(bp);
1891 	/*
1892 	 * We must wait for any I/O in progress to finish so that
1893 	 * all potential buffers on the dirty list will be visible.
1894 	 * Once they are all there, walk the list and get rid of
1895 	 * any dependencies.
1896 	 */
1897 	vp = ITOV(ip);
1898 	ACQUIRE_LOCK(&lk);
1899 	drain_output(vp, 1);
1900 
1901 	info.fs = fs;
1902 	info.ip = ip;
1903 	do {
1904 		count = RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree, NULL,
1905 				softdep_setup_freeblocks_bp, &info);
1906 	} while (count != 0);
1907 	if (inodedep_lookup(fs, ip->i_number, 0, &inodedep) != 0)
1908 		(void)free_inodedep(inodedep);
1909 
1910 	if (delay) {
1911 		freeblks->fb_state |= DEPCOMPLETE;
1912 		/*
1913 		 * If the inode with zeroed block pointers is now on disk
1914 		 * we can start freeing blocks. Add freeblks to the worklist
1915 		 * instead of calling  handle_workitem_freeblocks directly as
1916 		 * it is more likely that additional IO is needed to complete
1917 		 * the request here than in the !delay case.
1918 		 */
1919 		if ((freeblks->fb_state & ALLCOMPLETE) == ALLCOMPLETE)
1920 			add_to_worklist(&freeblks->fb_list);
1921 	}
1922 
1923 	FREE_LOCK(&lk);
1924 	/*
1925 	 * If the inode has never been written to disk (delay == 0),
1926 	 * then we can process the freeblks now that we have deleted
1927 	 * the dependencies.
1928 	 */
1929 	if (!delay)
1930 		handle_workitem_freeblocks(freeblks);
1931 }
1932 
1933 static int
1934 softdep_setup_freeblocks_bp(struct buf *bp, void *data)
1935 {
1936 	struct softdep_setup_freeblocks_info *info = data;
1937 	struct inodedep *inodedep;
1938 
1939 	if (getdirtybuf(&bp, MNT_WAIT) == 0) {
1940 		kprintf("softdep_setup_freeblocks_bp(1): caught bp %p going away\n", bp);
1941 		return(-1);
1942 	}
1943 	if (bp->b_vp != ITOV(info->ip) || (bp->b_flags & B_DELWRI) == 0) {
1944 		kprintf("softdep_setup_freeblocks_bp(2): caught bp %p going away\n", bp);
1945 		BUF_UNLOCK(bp);
1946 		return(-1);
1947 	}
1948 	(void) inodedep_lookup(info->fs, info->ip->i_number, 0, &inodedep);
1949 	deallocate_dependencies(bp, inodedep);
1950 	bp->b_flags |= B_INVAL | B_NOCACHE;
1951 	FREE_LOCK(&lk);
1952 	brelse(bp);
1953 	ACQUIRE_LOCK(&lk);
1954 	return(1);
1955 }
1956 
1957 /*
1958  * Reclaim any dependency structures from a buffer that is about to
1959  * be reallocated to a new vnode. The buffer must be locked, thus,
1960  * no I/O completion operations can occur while we are manipulating
1961  * its associated dependencies. The mutex is held so that other I/O's
1962  * associated with related dependencies do not occur.
1963  */
1964 static void
1965 deallocate_dependencies(struct buf *bp, struct inodedep *inodedep)
1966 {
1967 	struct worklist *wk;
1968 	struct indirdep *indirdep;
1969 	struct allocindir *aip;
1970 	struct pagedep *pagedep;
1971 	struct dirrem *dirrem;
1972 	struct diradd *dap;
1973 	int i;
1974 
1975 	while ((wk = LIST_FIRST(&bp->b_dep)) != NULL) {
1976 		switch (wk->wk_type) {
1977 
1978 		case D_INDIRDEP:
1979 			indirdep = WK_INDIRDEP(wk);
1980 			/*
1981 			 * None of the indirect pointers will ever be visible,
1982 			 * so they can simply be tossed. GOINGAWAY ensures
1983 			 * that allocated pointers will be saved in the buffer
1984 			 * cache until they are freed. Note that they will
1985 			 * only be able to be found by their physical address
1986 			 * since the inode mapping the logical address will
1987 			 * be gone. The save buffer used for the safe copy
1988 			 * was allocated in setup_allocindir_phase2 using
1989 			 * the physical address so it could be used for this
1990 			 * purpose. Hence we swap the safe copy with the real
1991 			 * copy, allowing the safe copy to be freed and holding
1992 			 * on to the real copy for later use in indir_trunc.
1993 			 *
1994 			 * NOTE: ir_savebp is relative to the block device
1995 			 * so b_bio1 contains the device block number.
1996 			 */
1997 			if (indirdep->ir_state & GOINGAWAY) {
1998 				FREE_LOCK(&lk);
1999 				panic("deallocate_dependencies: already gone");
2000 			}
2001 			indirdep->ir_state |= GOINGAWAY;
2002 			while ((aip = LIST_FIRST(&indirdep->ir_deplisthd)) != 0)
2003 				free_allocindir(aip, inodedep);
2004 			if (bp->b_bio1.bio_offset >= 0 ||
2005 			    bp->b_bio2.bio_offset != indirdep->ir_savebp->b_bio1.bio_offset) {
2006 				FREE_LOCK(&lk);
2007 				panic("deallocate_dependencies: not indir");
2008 			}
2009 			bcopy(bp->b_data, indirdep->ir_savebp->b_data,
2010 			    bp->b_bcount);
2011 			WORKLIST_REMOVE(wk);
2012 			WORKLIST_INSERT_BP(indirdep->ir_savebp, wk);
2013 			continue;
2014 
2015 		case D_PAGEDEP:
2016 			pagedep = WK_PAGEDEP(wk);
2017 			/*
2018 			 * None of the directory additions will ever be
2019 			 * visible, so they can simply be tossed.
2020 			 */
2021 			for (i = 0; i < DAHASHSZ; i++)
2022 				while ((dap =
2023 				    LIST_FIRST(&pagedep->pd_diraddhd[i])))
2024 					free_diradd(dap);
2025 			while ((dap = LIST_FIRST(&pagedep->pd_pendinghd)) != 0)
2026 				free_diradd(dap);
2027 			/*
2028 			 * Copy any directory remove dependencies to the list
2029 			 * to be processed after the zero'ed inode is written.
2030 			 * If the inode has already been written, then they
2031 			 * can be dumped directly onto the work list.
2032 			 */
2033 			LIST_FOREACH(dirrem, &pagedep->pd_dirremhd, dm_next) {
2034 				LIST_REMOVE(dirrem, dm_next);
2035 				dirrem->dm_dirinum = pagedep->pd_ino;
2036 				if (inodedep == NULL ||
2037 				    (inodedep->id_state & ALLCOMPLETE) ==
2038 				     ALLCOMPLETE)
2039 					add_to_worklist(&dirrem->dm_list);
2040 				else
2041 					WORKLIST_INSERT(&inodedep->id_bufwait,
2042 					    &dirrem->dm_list);
2043 			}
2044 			WORKLIST_REMOVE(&pagedep->pd_list);
2045 			LIST_REMOVE(pagedep, pd_hash);
2046 			WORKITEM_FREE(pagedep, D_PAGEDEP);
2047 			continue;
2048 
2049 		case D_ALLOCINDIR:
2050 			free_allocindir(WK_ALLOCINDIR(wk), inodedep);
2051 			continue;
2052 
2053 		case D_ALLOCDIRECT:
2054 		case D_INODEDEP:
2055 			FREE_LOCK(&lk);
2056 			panic("deallocate_dependencies: Unexpected type %s",
2057 			    TYPENAME(wk->wk_type));
2058 			/* NOTREACHED */
2059 
2060 		default:
2061 			FREE_LOCK(&lk);
2062 			panic("deallocate_dependencies: Unknown type %s",
2063 			    TYPENAME(wk->wk_type));
2064 			/* NOTREACHED */
2065 		}
2066 	}
2067 }
2068 
2069 /*
2070  * Free an allocdirect. Generate a new freefrag work request if appropriate.
2071  * This routine must be called with splbio interrupts blocked.
2072  */
2073 static void
2074 free_allocdirect(struct allocdirectlst *adphead,
2075 		 struct allocdirect *adp, int delay)
2076 {
2077 
2078 #ifdef DEBUG
2079 	if (lk.lkt_held == NOHOLDER)
2080 		panic("free_allocdirect: lock not held");
2081 #endif
2082 	if ((adp->ad_state & DEPCOMPLETE) == 0)
2083 		LIST_REMOVE(adp, ad_deps);
2084 	TAILQ_REMOVE(adphead, adp, ad_next);
2085 	if ((adp->ad_state & COMPLETE) == 0)
2086 		WORKLIST_REMOVE(&adp->ad_list);
2087 	if (adp->ad_freefrag != NULL) {
2088 		if (delay)
2089 			WORKLIST_INSERT(&adp->ad_inodedep->id_bufwait,
2090 			    &adp->ad_freefrag->ff_list);
2091 		else
2092 			add_to_worklist(&adp->ad_freefrag->ff_list);
2093 	}
2094 	WORKITEM_FREE(adp, D_ALLOCDIRECT);
2095 }
2096 
2097 /*
2098  * Prepare an inode to be freed. The actual free operation is not
2099  * done until the zero'ed inode has been written to disk.
2100  */
2101 void
2102 softdep_freefile(struct vnode *pvp, ino_t ino, int mode)
2103 {
2104 	struct inode *ip = VTOI(pvp);
2105 	struct inodedep *inodedep;
2106 	struct freefile *freefile;
2107 
2108 	/*
2109 	 * This sets up the inode de-allocation dependency.
2110 	 */
2111 	MALLOC(freefile, struct freefile *, sizeof(struct freefile),
2112 		M_FREEFILE, M_SOFTDEP_FLAGS);
2113 	freefile->fx_list.wk_type = D_FREEFILE;
2114 	freefile->fx_list.wk_state = 0;
2115 	freefile->fx_mode = mode;
2116 	freefile->fx_oldinum = ino;
2117 	freefile->fx_devvp = ip->i_devvp;
2118 	freefile->fx_fs = ip->i_fs;
2119 
2120 	/*
2121 	 * If the inodedep does not exist, then the zero'ed inode has
2122 	 * been written to disk. If the allocated inode has never been
2123 	 * written to disk, then the on-disk inode is zero'ed. In either
2124 	 * case we can free the file immediately.
2125 	 */
2126 	ACQUIRE_LOCK(&lk);
2127 	if (inodedep_lookup(ip->i_fs, ino, 0, &inodedep) == 0 ||
2128 	    check_inode_unwritten(inodedep)) {
2129 		FREE_LOCK(&lk);
2130 		handle_workitem_freefile(freefile);
2131 		return;
2132 	}
2133 	WORKLIST_INSERT(&inodedep->id_inowait, &freefile->fx_list);
2134 	FREE_LOCK(&lk);
2135 }
2136 
2137 /*
2138  * Check to see if an inode has never been written to disk. If
2139  * so free the inodedep and return success, otherwise return failure.
2140  * This routine must be called with splbio interrupts blocked.
2141  *
2142  * If we still have a bitmap dependency, then the inode has never
2143  * been written to disk. Drop the dependency as it is no longer
2144  * necessary since the inode is being deallocated. We set the
2145  * ALLCOMPLETE flags since the bitmap now properly shows that the
2146  * inode is not allocated. Even if the inode is actively being
2147  * written, it has been rolled back to its zero'ed state, so we
2148  * are ensured that a zero inode is what is on the disk. For short
2149  * lived files, this change will usually result in removing all the
2150  * dependencies from the inode so that it can be freed immediately.
2151  */
2152 static int
2153 check_inode_unwritten(struct inodedep *inodedep)
2154 {
2155 
2156 	if ((inodedep->id_state & DEPCOMPLETE) != 0 ||
2157 	    LIST_FIRST(&inodedep->id_pendinghd) != NULL ||
2158 	    LIST_FIRST(&inodedep->id_bufwait) != NULL ||
2159 	    LIST_FIRST(&inodedep->id_inowait) != NULL ||
2160 	    TAILQ_FIRST(&inodedep->id_inoupdt) != NULL ||
2161 	    TAILQ_FIRST(&inodedep->id_newinoupdt) != NULL ||
2162 	    inodedep->id_nlinkdelta != 0)
2163 		return (0);
2164 
2165 	/*
2166 	 * Another process might be in initiate_write_inodeblock
2167 	 * trying to allocate memory without holding "Softdep Lock".
2168 	 */
2169 	if ((inodedep->id_state & IOSTARTED) != 0 &&
2170 	    inodedep->id_savedino == NULL)
2171 		return(0);
2172 
2173 	inodedep->id_state |= ALLCOMPLETE;
2174 	LIST_REMOVE(inodedep, id_deps);
2175 	inodedep->id_buf = NULL;
2176 	if (inodedep->id_state & ONWORKLIST)
2177 		WORKLIST_REMOVE(&inodedep->id_list);
2178 	if (inodedep->id_savedino != NULL) {
2179 		FREE(inodedep->id_savedino, M_INODEDEP);
2180 		inodedep->id_savedino = NULL;
2181 	}
2182 	if (free_inodedep(inodedep) == 0) {
2183 		FREE_LOCK(&lk);
2184 		panic("check_inode_unwritten: busy inode");
2185 	}
2186 	return (1);
2187 }
2188 
2189 /*
2190  * Try to free an inodedep structure. Return 1 if it could be freed.
2191  */
2192 static int
2193 free_inodedep(struct inodedep *inodedep)
2194 {
2195 
2196 	if ((inodedep->id_state & ONWORKLIST) != 0 ||
2197 	    (inodedep->id_state & ALLCOMPLETE) != ALLCOMPLETE ||
2198 	    LIST_FIRST(&inodedep->id_pendinghd) != NULL ||
2199 	    LIST_FIRST(&inodedep->id_bufwait) != NULL ||
2200 	    LIST_FIRST(&inodedep->id_inowait) != NULL ||
2201 	    TAILQ_FIRST(&inodedep->id_inoupdt) != NULL ||
2202 	    TAILQ_FIRST(&inodedep->id_newinoupdt) != NULL ||
2203 	    inodedep->id_nlinkdelta != 0 || inodedep->id_savedino != NULL)
2204 		return (0);
2205 	LIST_REMOVE(inodedep, id_hash);
2206 	WORKITEM_FREE(inodedep, D_INODEDEP);
2207 	num_inodedep -= 1;
2208 	return (1);
2209 }
2210 
2211 /*
2212  * This workitem routine performs the block de-allocation.
2213  * The workitem is added to the pending list after the updated
2214  * inode block has been written to disk.  As mentioned above,
2215  * checks regarding the number of blocks de-allocated (compared
2216  * to the number of blocks allocated for the file) are also
2217  * performed in this function.
2218  */
2219 static void
2220 handle_workitem_freeblocks(struct freeblks *freeblks)
2221 {
2222 	struct inode tip;
2223 	ufs_daddr_t bn;
2224 	struct fs *fs;
2225 	int i, level, bsize;
2226 	long nblocks, blocksreleased = 0;
2227 	int error, allerror = 0;
2228 	ufs_lbn_t baselbns[NIADDR], tmpval;
2229 
2230 	tip.i_number = freeblks->fb_previousinum;
2231 	tip.i_devvp = freeblks->fb_devvp;
2232 	tip.i_dev = freeblks->fb_devvp->v_rdev;
2233 	tip.i_fs = freeblks->fb_fs;
2234 	tip.i_size = freeblks->fb_oldsize;
2235 	tip.i_uid = freeblks->fb_uid;
2236 	fs = freeblks->fb_fs;
2237 	tmpval = 1;
2238 	baselbns[0] = NDADDR;
2239 	for (i = 1; i < NIADDR; i++) {
2240 		tmpval *= NINDIR(fs);
2241 		baselbns[i] = baselbns[i - 1] + tmpval;
2242 	}
2243 	nblocks = btodb(fs->fs_bsize);
2244 	blocksreleased = 0;
2245 	/*
2246 	 * Indirect blocks first.
2247 	 */
2248 	for (level = (NIADDR - 1); level >= 0; level--) {
2249 		if ((bn = freeblks->fb_iblks[level]) == 0)
2250 			continue;
2251 		if ((error = indir_trunc(&tip, fsbtodoff(fs, bn), level,
2252 		    baselbns[level], &blocksreleased)) == 0)
2253 			allerror = error;
2254 		ffs_blkfree(&tip, bn, fs->fs_bsize);
2255 		blocksreleased += nblocks;
2256 	}
2257 	/*
2258 	 * All direct blocks or frags.
2259 	 */
2260 	for (i = (NDADDR - 1); i >= 0; i--) {
2261 		if ((bn = freeblks->fb_dblks[i]) == 0)
2262 			continue;
2263 		bsize = blksize(fs, &tip, i);
2264 		ffs_blkfree(&tip, bn, bsize);
2265 		blocksreleased += btodb(bsize);
2266 	}
2267 
2268 #ifdef DIAGNOSTIC
2269 	if (freeblks->fb_chkcnt != blocksreleased)
2270 		kprintf("handle_workitem_freeblocks: block count\n");
2271 	if (allerror)
2272 		softdep_error("handle_workitem_freeblks", allerror);
2273 #endif /* DIAGNOSTIC */
2274 	WORKITEM_FREE(freeblks, D_FREEBLKS);
2275 }
2276 
2277 /*
2278  * Release blocks associated with the inode ip and stored in the indirect
2279  * block at doffset. If level is greater than SINGLE, the block is an
2280  * indirect block and recursive calls to indirtrunc must be used to
2281  * cleanse other indirect blocks.
2282  */
2283 static int
2284 indir_trunc(struct inode *ip, off_t doffset, int level, ufs_lbn_t lbn,
2285 	    long *countp)
2286 {
2287 	struct buf *bp;
2288 	ufs_daddr_t *bap;
2289 	ufs_daddr_t nb;
2290 	struct fs *fs;
2291 	struct worklist *wk;
2292 	struct indirdep *indirdep;
2293 	int i, lbnadd, nblocks;
2294 	int error, allerror = 0;
2295 
2296 	fs = ip->i_fs;
2297 	lbnadd = 1;
2298 	for (i = level; i > 0; i--)
2299 		lbnadd *= NINDIR(fs);
2300 	/*
2301 	 * Get buffer of block pointers to be freed. This routine is not
2302 	 * called until the zero'ed inode has been written, so it is safe
2303 	 * to free blocks as they are encountered. Because the inode has
2304 	 * been zero'ed, calls to bmap on these blocks will fail. So, we
2305 	 * have to use the on-disk address and the block device for the
2306 	 * filesystem to look them up. If the file was deleted before its
2307 	 * indirect blocks were all written to disk, the routine that set
2308 	 * us up (deallocate_dependencies) will have arranged to leave
2309 	 * a complete copy of the indirect block in memory for our use.
2310 	 * Otherwise we have to read the blocks in from the disk.
2311 	 */
2312 	ACQUIRE_LOCK(&lk);
2313 	if ((bp = findblk(ip->i_devvp, doffset)) != NULL &&
2314 	    (wk = LIST_FIRST(&bp->b_dep)) != NULL) {
2315 		/*
2316 		 * bp must be ir_savebp, which is held locked for our use.
2317 		 */
2318 		if (wk->wk_type != D_INDIRDEP ||
2319 		    (indirdep = WK_INDIRDEP(wk))->ir_savebp != bp ||
2320 		    (indirdep->ir_state & GOINGAWAY) == 0) {
2321 			FREE_LOCK(&lk);
2322 			panic("indir_trunc: lost indirdep");
2323 		}
2324 		WORKLIST_REMOVE(wk);
2325 		WORKITEM_FREE(indirdep, D_INDIRDEP);
2326 		if (LIST_FIRST(&bp->b_dep) != NULL) {
2327 			FREE_LOCK(&lk);
2328 			panic("indir_trunc: dangling dep");
2329 		}
2330 		FREE_LOCK(&lk);
2331 	} else {
2332 		FREE_LOCK(&lk);
2333 		error = bread(ip->i_devvp, doffset, (int)fs->fs_bsize, &bp);
2334 		if (error)
2335 			return (error);
2336 	}
2337 	/*
2338 	 * Recursively free indirect blocks.
2339 	 */
2340 	bap = (ufs_daddr_t *)bp->b_data;
2341 	nblocks = btodb(fs->fs_bsize);
2342 	for (i = NINDIR(fs) - 1; i >= 0; i--) {
2343 		if ((nb = bap[i]) == 0)
2344 			continue;
2345 		if (level != 0) {
2346 			if ((error = indir_trunc(ip, fsbtodoff(fs, nb),
2347 			     level - 1, lbn + (i * lbnadd), countp)) != 0)
2348 				allerror = error;
2349 		}
2350 		ffs_blkfree(ip, nb, fs->fs_bsize);
2351 		*countp += nblocks;
2352 	}
2353 	bp->b_flags |= B_INVAL | B_NOCACHE;
2354 	brelse(bp);
2355 	return (allerror);
2356 }
2357 
2358 /*
2359  * Free an allocindir.
2360  * This routine must be called with splbio interrupts blocked.
2361  */
2362 static void
2363 free_allocindir(struct allocindir *aip, struct inodedep *inodedep)
2364 {
2365 	struct freefrag *freefrag;
2366 
2367 #ifdef DEBUG
2368 	if (lk.lkt_held == NOHOLDER)
2369 		panic("free_allocindir: lock not held");
2370 #endif
2371 	if ((aip->ai_state & DEPCOMPLETE) == 0)
2372 		LIST_REMOVE(aip, ai_deps);
2373 	if (aip->ai_state & ONWORKLIST)
2374 		WORKLIST_REMOVE(&aip->ai_list);
2375 	LIST_REMOVE(aip, ai_next);
2376 	if ((freefrag = aip->ai_freefrag) != NULL) {
2377 		if (inodedep == NULL)
2378 			add_to_worklist(&freefrag->ff_list);
2379 		else
2380 			WORKLIST_INSERT(&inodedep->id_bufwait,
2381 			    &freefrag->ff_list);
2382 	}
2383 	WORKITEM_FREE(aip, D_ALLOCINDIR);
2384 }
2385 
2386 /*
2387  * Directory entry addition dependencies.
2388  *
2389  * When adding a new directory entry, the inode (with its incremented link
2390  * count) must be written to disk before the directory entry's pointer to it.
2391  * Also, if the inode is newly allocated, the corresponding freemap must be
2392  * updated (on disk) before the directory entry's pointer. These requirements
2393  * are met via undo/redo on the directory entry's pointer, which consists
2394  * simply of the inode number.
2395  *
2396  * As directory entries are added and deleted, the free space within a
2397  * directory block can become fragmented.  The ufs filesystem will compact
2398  * a fragmented directory block to make space for a new entry. When this
2399  * occurs, the offsets of previously added entries change. Any "diradd"
2400  * dependency structures corresponding to these entries must be updated with
2401  * the new offsets.
2402  */
2403 
2404 /*
2405  * This routine is called after the in-memory inode's link
2406  * count has been incremented, but before the directory entry's
2407  * pointer to the inode has been set.
2408  *
2409  * Parameters:
2410  *	bp:		buffer containing directory block
2411  *	dp:		inode for directory
2412  *	diroffset:	offset of new entry in directory
2413  *	newinum:	inode referenced by new directory entry
2414  *	newdirbp:	non-NULL => contents of new mkdir
2415  */
2416 void
2417 softdep_setup_directory_add(struct buf *bp, struct inode *dp, off_t diroffset,
2418 			    ino_t newinum, struct buf *newdirbp)
2419 {
2420 	int offset;		/* offset of new entry within directory block */
2421 	ufs_lbn_t lbn;		/* block in directory containing new entry */
2422 	struct fs *fs;
2423 	struct diradd *dap;
2424 	struct pagedep *pagedep;
2425 	struct inodedep *inodedep;
2426 	struct mkdir *mkdir1, *mkdir2;
2427 
2428 	/*
2429 	 * Whiteouts have no dependencies.
2430 	 */
2431 	if (newinum == WINO) {
2432 		if (newdirbp != NULL)
2433 			bdwrite(newdirbp);
2434 		return;
2435 	}
2436 
2437 	fs = dp->i_fs;
2438 	lbn = lblkno(fs, diroffset);
2439 	offset = blkoff(fs, diroffset);
2440 	MALLOC(dap, struct diradd *, sizeof(struct diradd), M_DIRADD,
2441 	    M_SOFTDEP_FLAGS | M_ZERO);
2442 	dap->da_list.wk_type = D_DIRADD;
2443 	dap->da_offset = offset;
2444 	dap->da_newinum = newinum;
2445 	dap->da_state = ATTACHED;
2446 	if (newdirbp == NULL) {
2447 		dap->da_state |= DEPCOMPLETE;
2448 		ACQUIRE_LOCK(&lk);
2449 	} else {
2450 		dap->da_state |= MKDIR_BODY | MKDIR_PARENT;
2451 		MALLOC(mkdir1, struct mkdir *, sizeof(struct mkdir), M_MKDIR,
2452 		    M_SOFTDEP_FLAGS);
2453 		mkdir1->md_list.wk_type = D_MKDIR;
2454 		mkdir1->md_state = MKDIR_BODY;
2455 		mkdir1->md_diradd = dap;
2456 		MALLOC(mkdir2, struct mkdir *, sizeof(struct mkdir), M_MKDIR,
2457 		    M_SOFTDEP_FLAGS);
2458 		mkdir2->md_list.wk_type = D_MKDIR;
2459 		mkdir2->md_state = MKDIR_PARENT;
2460 		mkdir2->md_diradd = dap;
2461 		/*
2462 		 * Dependency on "." and ".." being written to disk.
2463 		 */
2464 		mkdir1->md_buf = newdirbp;
2465 		ACQUIRE_LOCK(&lk);
2466 		LIST_INSERT_HEAD(&mkdirlisthd, mkdir1, md_mkdirs);
2467 		WORKLIST_INSERT_BP(newdirbp, &mkdir1->md_list);
2468 		FREE_LOCK(&lk);
2469 		bdwrite(newdirbp);
2470 		/*
2471 		 * Dependency on link count increase for parent directory
2472 		 */
2473 		ACQUIRE_LOCK(&lk);
2474 		if (inodedep_lookup(dp->i_fs, dp->i_number, 0, &inodedep) == 0
2475 		    || (inodedep->id_state & ALLCOMPLETE) == ALLCOMPLETE) {
2476 			dap->da_state &= ~MKDIR_PARENT;
2477 			WORKITEM_FREE(mkdir2, D_MKDIR);
2478 		} else {
2479 			LIST_INSERT_HEAD(&mkdirlisthd, mkdir2, md_mkdirs);
2480 			WORKLIST_INSERT(&inodedep->id_bufwait,&mkdir2->md_list);
2481 		}
2482 	}
2483 	/*
2484 	 * Link into parent directory pagedep to await its being written.
2485 	 */
2486 	if (pagedep_lookup(dp, lbn, DEPALLOC, &pagedep) == 0)
2487 		WORKLIST_INSERT_BP(bp, &pagedep->pd_list);
2488 	dap->da_pagedep = pagedep;
2489 	LIST_INSERT_HEAD(&pagedep->pd_diraddhd[DIRADDHASH(offset)], dap,
2490 	    da_pdlist);
2491 	/*
2492 	 * Link into its inodedep. Put it on the id_bufwait list if the inode
2493 	 * is not yet written. If it is written, do the post-inode write
2494 	 * processing to put it on the id_pendinghd list.
2495 	 */
2496 	(void) inodedep_lookup(fs, newinum, DEPALLOC, &inodedep);
2497 	if ((inodedep->id_state & ALLCOMPLETE) == ALLCOMPLETE)
2498 		diradd_inode_written(dap, inodedep);
2499 	else
2500 		WORKLIST_INSERT(&inodedep->id_bufwait, &dap->da_list);
2501 	FREE_LOCK(&lk);
2502 }
2503 
2504 /*
2505  * This procedure is called to change the offset of a directory
2506  * entry when compacting a directory block which must be owned
2507  * exclusively by the caller. Note that the actual entry movement
2508  * must be done in this procedure to ensure that no I/O completions
2509  * occur while the move is in progress.
2510  *
2511  * Parameters:
2512  *	dp:	inode for directory
2513  *	base:		address of dp->i_offset
2514  *	oldloc:		address of old directory location
2515  *	newloc:		address of new directory location
2516  *	entrysize:	size of directory entry
2517  */
2518 void
2519 softdep_change_directoryentry_offset(struct inode *dp, caddr_t base,
2520 				     caddr_t oldloc, caddr_t newloc,
2521 				     int entrysize)
2522 {
2523 	int offset, oldoffset, newoffset;
2524 	struct pagedep *pagedep;
2525 	struct diradd *dap;
2526 	ufs_lbn_t lbn;
2527 
2528 	ACQUIRE_LOCK(&lk);
2529 	lbn = lblkno(dp->i_fs, dp->i_offset);
2530 	offset = blkoff(dp->i_fs, dp->i_offset);
2531 	if (pagedep_lookup(dp, lbn, 0, &pagedep) == 0)
2532 		goto done;
2533 	oldoffset = offset + (oldloc - base);
2534 	newoffset = offset + (newloc - base);
2535 
2536 	LIST_FOREACH(dap, &pagedep->pd_diraddhd[DIRADDHASH(oldoffset)], da_pdlist) {
2537 		if (dap->da_offset != oldoffset)
2538 			continue;
2539 		dap->da_offset = newoffset;
2540 		if (DIRADDHASH(newoffset) == DIRADDHASH(oldoffset))
2541 			break;
2542 		LIST_REMOVE(dap, da_pdlist);
2543 		LIST_INSERT_HEAD(&pagedep->pd_diraddhd[DIRADDHASH(newoffset)],
2544 		    dap, da_pdlist);
2545 		break;
2546 	}
2547 	if (dap == NULL) {
2548 
2549 		LIST_FOREACH(dap, &pagedep->pd_pendinghd, da_pdlist) {
2550 			if (dap->da_offset == oldoffset) {
2551 				dap->da_offset = newoffset;
2552 				break;
2553 			}
2554 		}
2555 	}
2556 done:
2557 	bcopy(oldloc, newloc, entrysize);
2558 	FREE_LOCK(&lk);
2559 }
2560 
2561 /*
2562  * Free a diradd dependency structure. This routine must be called
2563  * with splbio interrupts blocked.
2564  */
2565 static void
2566 free_diradd(struct diradd *dap)
2567 {
2568 	struct dirrem *dirrem;
2569 	struct pagedep *pagedep;
2570 	struct inodedep *inodedep;
2571 	struct mkdir *mkdir, *nextmd;
2572 
2573 #ifdef DEBUG
2574 	if (lk.lkt_held == NOHOLDER)
2575 		panic("free_diradd: lock not held");
2576 #endif
2577 	WORKLIST_REMOVE(&dap->da_list);
2578 	LIST_REMOVE(dap, da_pdlist);
2579 	if ((dap->da_state & DIRCHG) == 0) {
2580 		pagedep = dap->da_pagedep;
2581 	} else {
2582 		dirrem = dap->da_previous;
2583 		pagedep = dirrem->dm_pagedep;
2584 		dirrem->dm_dirinum = pagedep->pd_ino;
2585 		add_to_worklist(&dirrem->dm_list);
2586 	}
2587 	if (inodedep_lookup(VFSTOUFS(pagedep->pd_mnt)->um_fs, dap->da_newinum,
2588 	    0, &inodedep) != 0)
2589 		(void) free_inodedep(inodedep);
2590 	if ((dap->da_state & (MKDIR_PARENT | MKDIR_BODY)) != 0) {
2591 		for (mkdir = LIST_FIRST(&mkdirlisthd); mkdir; mkdir = nextmd) {
2592 			nextmd = LIST_NEXT(mkdir, md_mkdirs);
2593 			if (mkdir->md_diradd != dap)
2594 				continue;
2595 			dap->da_state &= ~mkdir->md_state;
2596 			WORKLIST_REMOVE(&mkdir->md_list);
2597 			LIST_REMOVE(mkdir, md_mkdirs);
2598 			WORKITEM_FREE(mkdir, D_MKDIR);
2599 		}
2600 		if ((dap->da_state & (MKDIR_PARENT | MKDIR_BODY)) != 0) {
2601 			FREE_LOCK(&lk);
2602 			panic("free_diradd: unfound ref");
2603 		}
2604 	}
2605 	WORKITEM_FREE(dap, D_DIRADD);
2606 }
2607 
2608 /*
2609  * Directory entry removal dependencies.
2610  *
2611  * When removing a directory entry, the entry's inode pointer must be
2612  * zero'ed on disk before the corresponding inode's link count is decremented
2613  * (possibly freeing the inode for re-use). This dependency is handled by
2614  * updating the directory entry but delaying the inode count reduction until
2615  * after the directory block has been written to disk. After this point, the
2616  * inode count can be decremented whenever it is convenient.
2617  */
2618 
2619 /*
2620  * This routine should be called immediately after removing
2621  * a directory entry.  The inode's link count should not be
2622  * decremented by the calling procedure -- the soft updates
2623  * code will do this task when it is safe.
2624  *
2625  * Parameters:
2626  *	bp:		buffer containing directory block
2627  *	dp:		inode for the directory being modified
2628  *	ip:		inode for directory entry being removed
2629  *	isrmdir:	indicates if doing RMDIR
2630  */
2631 void
2632 softdep_setup_remove(struct buf *bp, struct inode *dp, struct inode *ip,
2633 		     int isrmdir)
2634 {
2635 	struct dirrem *dirrem, *prevdirrem;
2636 
2637 	/*
2638 	 * Allocate a new dirrem if appropriate and ACQUIRE_LOCK.
2639 	 */
2640 	dirrem = newdirrem(bp, dp, ip, isrmdir, &prevdirrem);
2641 
2642 	/*
2643 	 * If the COMPLETE flag is clear, then there were no active
2644 	 * entries and we want to roll back to a zeroed entry until
2645 	 * the new inode is committed to disk. If the COMPLETE flag is
2646 	 * set then we have deleted an entry that never made it to
2647 	 * disk. If the entry we deleted resulted from a name change,
2648 	 * then the old name still resides on disk. We cannot delete
2649 	 * its inode (returned to us in prevdirrem) until the zeroed
2650 	 * directory entry gets to disk. The new inode has never been
2651 	 * referenced on the disk, so can be deleted immediately.
2652 	 */
2653 	if ((dirrem->dm_state & COMPLETE) == 0) {
2654 		LIST_INSERT_HEAD(&dirrem->dm_pagedep->pd_dirremhd, dirrem,
2655 		    dm_next);
2656 		FREE_LOCK(&lk);
2657 	} else {
2658 		if (prevdirrem != NULL)
2659 			LIST_INSERT_HEAD(&dirrem->dm_pagedep->pd_dirremhd,
2660 			    prevdirrem, dm_next);
2661 		dirrem->dm_dirinum = dirrem->dm_pagedep->pd_ino;
2662 		FREE_LOCK(&lk);
2663 		handle_workitem_remove(dirrem);
2664 	}
2665 }
2666 
2667 /*
2668  * Allocate a new dirrem if appropriate and return it along with
2669  * its associated pagedep. Called without a lock, returns with lock.
2670  */
2671 static long num_dirrem;		/* number of dirrem allocated */
2672 
2673 /*
2674  * Parameters:
2675  *	bp:		buffer containing directory block
2676  *	dp:		inode for the directory being modified
2677  *	ip:		inode for directory entry being removed
2678  *	isrmdir:	indicates if doing RMDIR
2679  *	prevdirremp:	previously referenced inode, if any
2680  */
2681 static struct dirrem *
2682 newdirrem(struct buf *bp, struct inode *dp, struct inode *ip,
2683 	  int isrmdir, struct dirrem **prevdirremp)
2684 {
2685 	int offset;
2686 	ufs_lbn_t lbn;
2687 	struct diradd *dap;
2688 	struct dirrem *dirrem;
2689 	struct pagedep *pagedep;
2690 
2691 	/*
2692 	 * Whiteouts have no deletion dependencies.
2693 	 */
2694 	if (ip == NULL)
2695 		panic("newdirrem: whiteout");
2696 	/*
2697 	 * If we are over our limit, try to improve the situation.
2698 	 * Limiting the number of dirrem structures will also limit
2699 	 * the number of freefile and freeblks structures.
2700 	 */
2701 	if (num_dirrem > max_softdeps / 2 && speedup_syncer() == 0)
2702 		(void) request_cleanup(FLUSH_REMOVE, 0);
2703 	num_dirrem += 1;
2704 	MALLOC(dirrem, struct dirrem *, sizeof(struct dirrem),
2705 		M_DIRREM, M_SOFTDEP_FLAGS | M_ZERO);
2706 	dirrem->dm_list.wk_type = D_DIRREM;
2707 	dirrem->dm_state = isrmdir ? RMDIR : 0;
2708 	dirrem->dm_mnt = ITOV(ip)->v_mount;
2709 	dirrem->dm_oldinum = ip->i_number;
2710 	*prevdirremp = NULL;
2711 
2712 	ACQUIRE_LOCK(&lk);
2713 	lbn = lblkno(dp->i_fs, dp->i_offset);
2714 	offset = blkoff(dp->i_fs, dp->i_offset);
2715 	if (pagedep_lookup(dp, lbn, DEPALLOC, &pagedep) == 0)
2716 		WORKLIST_INSERT_BP(bp, &pagedep->pd_list);
2717 	dirrem->dm_pagedep = pagedep;
2718 	/*
2719 	 * Check for a diradd dependency for the same directory entry.
2720 	 * If present, then both dependencies become obsolete and can
2721 	 * be de-allocated. Check for an entry on both the pd_dirraddhd
2722 	 * list and the pd_pendinghd list.
2723 	 */
2724 
2725 	LIST_FOREACH(dap, &pagedep->pd_diraddhd[DIRADDHASH(offset)], da_pdlist)
2726 		if (dap->da_offset == offset)
2727 			break;
2728 	if (dap == NULL) {
2729 
2730 		LIST_FOREACH(dap, &pagedep->pd_pendinghd, da_pdlist)
2731 			if (dap->da_offset == offset)
2732 				break;
2733 		if (dap == NULL)
2734 			return (dirrem);
2735 	}
2736 	/*
2737 	 * Must be ATTACHED at this point.
2738 	 */
2739 	if ((dap->da_state & ATTACHED) == 0) {
2740 		FREE_LOCK(&lk);
2741 		panic("newdirrem: not ATTACHED");
2742 	}
2743 	if (dap->da_newinum != ip->i_number) {
2744 		FREE_LOCK(&lk);
2745 		panic("newdirrem: inum %"PRId64" should be %"PRId64,
2746 		    ip->i_number, dap->da_newinum);
2747 	}
2748 	/*
2749 	 * If we are deleting a changed name that never made it to disk,
2750 	 * then return the dirrem describing the previous inode (which
2751 	 * represents the inode currently referenced from this entry on disk).
2752 	 */
2753 	if ((dap->da_state & DIRCHG) != 0) {
2754 		*prevdirremp = dap->da_previous;
2755 		dap->da_state &= ~DIRCHG;
2756 		dap->da_pagedep = pagedep;
2757 	}
2758 	/*
2759 	 * We are deleting an entry that never made it to disk.
2760 	 * Mark it COMPLETE so we can delete its inode immediately.
2761 	 */
2762 	dirrem->dm_state |= COMPLETE;
2763 	free_diradd(dap);
2764 	return (dirrem);
2765 }
2766 
2767 /*
2768  * Directory entry change dependencies.
2769  *
2770  * Changing an existing directory entry requires that an add operation
2771  * be completed first followed by a deletion. The semantics for the addition
2772  * are identical to the description of adding a new entry above except
2773  * that the rollback is to the old inode number rather than zero. Once
2774  * the addition dependency is completed, the removal is done as described
2775  * in the removal routine above.
2776  */
2777 
2778 /*
2779  * This routine should be called immediately after changing
2780  * a directory entry.  The inode's link count should not be
2781  * decremented by the calling procedure -- the soft updates
2782  * code will perform this task when it is safe.
2783  *
2784  * Parameters:
2785  *	bp:		buffer containing directory block
2786  *	dp:		inode for the directory being modified
2787  *	ip:		inode for directory entry being removed
2788  *	newinum:	new inode number for changed entry
2789  *	isrmdir:	indicates if doing RMDIR
2790  */
2791 void
2792 softdep_setup_directory_change(struct buf *bp, struct inode *dp,
2793 			       struct inode *ip, ino_t newinum,
2794 			       int isrmdir)
2795 {
2796 	int offset;
2797 	struct diradd *dap = NULL;
2798 	struct dirrem *dirrem, *prevdirrem;
2799 	struct pagedep *pagedep;
2800 	struct inodedep *inodedep;
2801 
2802 	offset = blkoff(dp->i_fs, dp->i_offset);
2803 
2804 	/*
2805 	 * Whiteouts do not need diradd dependencies.
2806 	 */
2807 	if (newinum != WINO) {
2808 		MALLOC(dap, struct diradd *, sizeof(struct diradd),
2809 		    M_DIRADD, M_SOFTDEP_FLAGS | M_ZERO);
2810 		dap->da_list.wk_type = D_DIRADD;
2811 		dap->da_state = DIRCHG | ATTACHED | DEPCOMPLETE;
2812 		dap->da_offset = offset;
2813 		dap->da_newinum = newinum;
2814 	}
2815 
2816 	/*
2817 	 * Allocate a new dirrem and ACQUIRE_LOCK.
2818 	 */
2819 	dirrem = newdirrem(bp, dp, ip, isrmdir, &prevdirrem);
2820 	pagedep = dirrem->dm_pagedep;
2821 	/*
2822 	 * The possible values for isrmdir:
2823 	 *	0 - non-directory file rename
2824 	 *	1 - directory rename within same directory
2825 	 *   inum - directory rename to new directory of given inode number
2826 	 * When renaming to a new directory, we are both deleting and
2827 	 * creating a new directory entry, so the link count on the new
2828 	 * directory should not change. Thus we do not need the followup
2829 	 * dirrem which is usually done in handle_workitem_remove. We set
2830 	 * the DIRCHG flag to tell handle_workitem_remove to skip the
2831 	 * followup dirrem.
2832 	 */
2833 	if (isrmdir > 1)
2834 		dirrem->dm_state |= DIRCHG;
2835 
2836 	/*
2837 	 * Whiteouts have no additional dependencies,
2838 	 * so just put the dirrem on the correct list.
2839 	 */
2840 	if (newinum == WINO) {
2841 		if ((dirrem->dm_state & COMPLETE) == 0) {
2842 			LIST_INSERT_HEAD(&pagedep->pd_dirremhd, dirrem,
2843 			    dm_next);
2844 		} else {
2845 			dirrem->dm_dirinum = pagedep->pd_ino;
2846 			add_to_worklist(&dirrem->dm_list);
2847 		}
2848 		FREE_LOCK(&lk);
2849 		return;
2850 	}
2851 
2852 	/*
2853 	 * If the COMPLETE flag is clear, then there were no active
2854 	 * entries and we want to roll back to the previous inode until
2855 	 * the new inode is committed to disk. If the COMPLETE flag is
2856 	 * set, then we have deleted an entry that never made it to disk.
2857 	 * If the entry we deleted resulted from a name change, then the old
2858 	 * inode reference still resides on disk. Any rollback that we do
2859 	 * needs to be to that old inode (returned to us in prevdirrem). If
2860 	 * the entry we deleted resulted from a create, then there is
2861 	 * no entry on the disk, so we want to roll back to zero rather
2862 	 * than the uncommitted inode. In either of the COMPLETE cases we
2863 	 * want to immediately free the unwritten and unreferenced inode.
2864 	 */
2865 	if ((dirrem->dm_state & COMPLETE) == 0) {
2866 		dap->da_previous = dirrem;
2867 	} else {
2868 		if (prevdirrem != NULL) {
2869 			dap->da_previous = prevdirrem;
2870 		} else {
2871 			dap->da_state &= ~DIRCHG;
2872 			dap->da_pagedep = pagedep;
2873 		}
2874 		dirrem->dm_dirinum = pagedep->pd_ino;
2875 		add_to_worklist(&dirrem->dm_list);
2876 	}
2877 	/*
2878 	 * Link into its inodedep. Put it on the id_bufwait list if the inode
2879 	 * is not yet written. If it is written, do the post-inode write
2880 	 * processing to put it on the id_pendinghd list.
2881 	 */
2882 	if (inodedep_lookup(dp->i_fs, newinum, DEPALLOC, &inodedep) == 0 ||
2883 	    (inodedep->id_state & ALLCOMPLETE) == ALLCOMPLETE) {
2884 		dap->da_state |= COMPLETE;
2885 		LIST_INSERT_HEAD(&pagedep->pd_pendinghd, dap, da_pdlist);
2886 		WORKLIST_INSERT(&inodedep->id_pendinghd, &dap->da_list);
2887 	} else {
2888 		LIST_INSERT_HEAD(&pagedep->pd_diraddhd[DIRADDHASH(offset)],
2889 		    dap, da_pdlist);
2890 		WORKLIST_INSERT(&inodedep->id_bufwait, &dap->da_list);
2891 	}
2892 	FREE_LOCK(&lk);
2893 }
2894 
2895 /*
2896  * Called whenever the link count on an inode is changed.
2897  * It creates an inode dependency so that the new reference(s)
2898  * to the inode cannot be committed to disk until the updated
2899  * inode has been written.
2900  *
2901  * Parameters:
2902  *	ip:	the inode with the increased link count
2903  */
2904 void
2905 softdep_change_linkcnt(struct inode *ip)
2906 {
2907 	struct inodedep *inodedep;
2908 
2909 	ACQUIRE_LOCK(&lk);
2910 	(void) inodedep_lookup(ip->i_fs, ip->i_number, DEPALLOC, &inodedep);
2911 	if (ip->i_nlink < ip->i_effnlink) {
2912 		FREE_LOCK(&lk);
2913 		panic("softdep_change_linkcnt: bad delta");
2914 	}
2915 	inodedep->id_nlinkdelta = ip->i_nlink - ip->i_effnlink;
2916 	FREE_LOCK(&lk);
2917 }
2918 
2919 /*
2920  * This workitem decrements the inode's link count.
2921  * If the link count reaches zero, the file is removed.
2922  */
2923 static void
2924 handle_workitem_remove(struct dirrem *dirrem)
2925 {
2926 	struct inodedep *inodedep;
2927 	struct vnode *vp;
2928 	struct inode *ip;
2929 	ino_t oldinum;
2930 	int error;
2931 
2932 	if ((error = VFS_VGET(dirrem->dm_mnt, dirrem->dm_oldinum, &vp)) != 0) {
2933 		softdep_error("handle_workitem_remove: vget", error);
2934 		return;
2935 	}
2936 	ip = VTOI(vp);
2937 	ACQUIRE_LOCK(&lk);
2938 	if ((inodedep_lookup(ip->i_fs, dirrem->dm_oldinum, 0, &inodedep)) == 0){
2939 		FREE_LOCK(&lk);
2940 		panic("handle_workitem_remove: lost inodedep");
2941 	}
2942 	/*
2943 	 * Normal file deletion.
2944 	 */
2945 	if ((dirrem->dm_state & RMDIR) == 0) {
2946 		ip->i_nlink--;
2947 		ip->i_flag |= IN_CHANGE;
2948 		if (ip->i_nlink < ip->i_effnlink) {
2949 			FREE_LOCK(&lk);
2950 			panic("handle_workitem_remove: bad file delta");
2951 		}
2952 		inodedep->id_nlinkdelta = ip->i_nlink - ip->i_effnlink;
2953 		FREE_LOCK(&lk);
2954 		vput(vp);
2955 		num_dirrem -= 1;
2956 		WORKITEM_FREE(dirrem, D_DIRREM);
2957 		return;
2958 	}
2959 	/*
2960 	 * Directory deletion. Decrement reference count for both the
2961 	 * just deleted parent directory entry and the reference for ".".
2962 	 * Next truncate the directory to length zero. When the
2963 	 * truncation completes, arrange to have the reference count on
2964 	 * the parent decremented to account for the loss of "..".
2965 	 */
2966 	ip->i_nlink -= 2;
2967 	ip->i_flag |= IN_CHANGE;
2968 	if (ip->i_nlink < ip->i_effnlink) {
2969 		FREE_LOCK(&lk);
2970 		panic("handle_workitem_remove: bad dir delta");
2971 	}
2972 	inodedep->id_nlinkdelta = ip->i_nlink - ip->i_effnlink;
2973 	FREE_LOCK(&lk);
2974 	if ((error = ffs_truncate(vp, (off_t)0, 0, proc0.p_ucred)) != 0)
2975 		softdep_error("handle_workitem_remove: truncate", error);
2976 	/*
2977 	 * Rename a directory to a new parent. Since, we are both deleting
2978 	 * and creating a new directory entry, the link count on the new
2979 	 * directory should not change. Thus we skip the followup dirrem.
2980 	 */
2981 	if (dirrem->dm_state & DIRCHG) {
2982 		vput(vp);
2983 		num_dirrem -= 1;
2984 		WORKITEM_FREE(dirrem, D_DIRREM);
2985 		return;
2986 	}
2987 	/*
2988 	 * If the inodedep does not exist, then the zero'ed inode has
2989 	 * been written to disk. If the allocated inode has never been
2990 	 * written to disk, then the on-disk inode is zero'ed. In either
2991 	 * case we can remove the file immediately.
2992 	 */
2993 	ACQUIRE_LOCK(&lk);
2994 	dirrem->dm_state = 0;
2995 	oldinum = dirrem->dm_oldinum;
2996 	dirrem->dm_oldinum = dirrem->dm_dirinum;
2997 	if (inodedep_lookup(ip->i_fs, oldinum, 0, &inodedep) == 0 ||
2998 	    check_inode_unwritten(inodedep)) {
2999 		FREE_LOCK(&lk);
3000 		vput(vp);
3001 		handle_workitem_remove(dirrem);
3002 		return;
3003 	}
3004 	WORKLIST_INSERT(&inodedep->id_inowait, &dirrem->dm_list);
3005 	FREE_LOCK(&lk);
3006 	ip->i_flag |= IN_CHANGE;
3007 	ffs_update(vp, 0);
3008 	vput(vp);
3009 }
3010 
3011 /*
3012  * Inode de-allocation dependencies.
3013  *
3014  * When an inode's link count is reduced to zero, it can be de-allocated. We
3015  * found it convenient to postpone de-allocation until after the inode is
3016  * written to disk with its new link count (zero).  At this point, all of the
3017  * on-disk inode's block pointers are nullified and, with careful dependency
3018  * list ordering, all dependencies related to the inode will be satisfied and
3019  * the corresponding dependency structures de-allocated.  So, if/when the
3020  * inode is reused, there will be no mixing of old dependencies with new
3021  * ones.  This artificial dependency is set up by the block de-allocation
3022  * procedure above (softdep_setup_freeblocks) and completed by the
3023  * following procedure.
3024  */
3025 static void
3026 handle_workitem_freefile(struct freefile *freefile)
3027 {
3028 	struct vnode vp;
3029 	struct inode tip;
3030 	struct inodedep *idp;
3031 	int error;
3032 
3033 #ifdef DEBUG
3034 	ACQUIRE_LOCK(&lk);
3035 	error = inodedep_lookup(freefile->fx_fs, freefile->fx_oldinum, 0, &idp);
3036 	FREE_LOCK(&lk);
3037 	if (error)
3038 		panic("handle_workitem_freefile: inodedep survived");
3039 #endif
3040 	tip.i_devvp = freefile->fx_devvp;
3041 	tip.i_dev = freefile->fx_devvp->v_rdev;
3042 	tip.i_fs = freefile->fx_fs;
3043 	vp.v_data = &tip;
3044 	if ((error = ffs_freefile(&vp, freefile->fx_oldinum, freefile->fx_mode)) != 0)
3045 		softdep_error("handle_workitem_freefile", error);
3046 	WORKITEM_FREE(freefile, D_FREEFILE);
3047 }
3048 
3049 /*
3050  * Helper function which unlinks marker element from work list and returns
3051  * the next element on the list.
3052  */
3053 static __inline struct worklist *
3054 markernext(struct worklist *marker)
3055 {
3056 	struct worklist *next;
3057 
3058 	next = LIST_NEXT(marker, wk_list);
3059 	LIST_REMOVE(marker, wk_list);
3060 	return next;
3061 }
3062 
3063 /*
3064  * checkread, checkwrite
3065  *
3066  */
3067 static  int
3068 softdep_checkread(struct buf *bp)
3069 {
3070 	return(0);
3071 }
3072 
3073 static  int
3074 softdep_checkwrite(struct buf *bp)
3075 {
3076 	return(0);
3077 }
3078 
3079 /*
3080  * Disk writes.
3081  *
3082  * The dependency structures constructed above are most actively used when file
3083  * system blocks are written to disk.  No constraints are placed on when a
3084  * block can be written, but unsatisfied update dependencies are made safe by
3085  * modifying (or replacing) the source memory for the duration of the disk
3086  * write.  When the disk write completes, the memory block is again brought
3087  * up-to-date.
3088  *
3089  * In-core inode structure reclamation.
3090  *
3091  * Because there are a finite number of "in-core" inode structures, they are
3092  * reused regularly.  By transferring all inode-related dependencies to the
3093  * in-memory inode block and indexing them separately (via "inodedep"s), we
3094  * can allow "in-core" inode structures to be reused at any time and avoid
3095  * any increase in contention.
3096  *
3097  * Called just before entering the device driver to initiate a new disk I/O.
3098  * The buffer must be locked, thus, no I/O completion operations can occur
3099  * while we are manipulating its associated dependencies.
3100  *
3101  * Parameters:
3102  *	bp:	structure describing disk write to occur
3103  */
3104 static void
3105 softdep_disk_io_initiation(struct buf *bp)
3106 {
3107 	struct worklist *wk;
3108 	struct worklist marker;
3109 	struct indirdep *indirdep;
3110 
3111 	/*
3112 	 * We only care about write operations. There should never
3113 	 * be dependencies for reads.
3114 	 */
3115 	if (bp->b_cmd == BUF_CMD_READ)
3116 		panic("softdep_disk_io_initiation: read");
3117 
3118 	marker.wk_type = D_LAST + 1;	/* Not a normal workitem */
3119 
3120 	/*
3121 	 * Do any necessary pre-I/O processing.
3122 	 */
3123 	for (wk = LIST_FIRST(&bp->b_dep); wk; wk = markernext(&marker)) {
3124 		LIST_INSERT_AFTER(wk, &marker, wk_list);
3125 
3126 		switch (wk->wk_type) {
3127 
3128 		case D_PAGEDEP:
3129 			initiate_write_filepage(WK_PAGEDEP(wk), bp);
3130 			continue;
3131 
3132 		case D_INODEDEP:
3133 			initiate_write_inodeblock(WK_INODEDEP(wk), bp);
3134 			continue;
3135 
3136 		case D_INDIRDEP:
3137 			indirdep = WK_INDIRDEP(wk);
3138 			if (indirdep->ir_state & GOINGAWAY)
3139 				panic("disk_io_initiation: indirdep gone");
3140 			/*
3141 			 * If there are no remaining dependencies, this
3142 			 * will be writing the real pointers, so the
3143 			 * dependency can be freed.
3144 			 */
3145 			if (LIST_FIRST(&indirdep->ir_deplisthd) == NULL) {
3146 				indirdep->ir_savebp->b_flags |= B_INVAL | B_NOCACHE;
3147 				brelse(indirdep->ir_savebp);
3148 				/* inline expand WORKLIST_REMOVE(wk); */
3149 				wk->wk_state &= ~ONWORKLIST;
3150 				LIST_REMOVE(wk, wk_list);
3151 				WORKITEM_FREE(indirdep, D_INDIRDEP);
3152 				continue;
3153 			}
3154 			/*
3155 			 * Replace up-to-date version with safe version.
3156 			 */
3157 			MALLOC(indirdep->ir_saveddata, caddr_t, bp->b_bcount,
3158 			    M_INDIRDEP, M_SOFTDEP_FLAGS);
3159 			ACQUIRE_LOCK(&lk);
3160 			indirdep->ir_state &= ~ATTACHED;
3161 			indirdep->ir_state |= UNDONE;
3162 			bcopy(bp->b_data, indirdep->ir_saveddata, bp->b_bcount);
3163 			bcopy(indirdep->ir_savebp->b_data, bp->b_data,
3164 			    bp->b_bcount);
3165 			FREE_LOCK(&lk);
3166 			continue;
3167 
3168 		case D_MKDIR:
3169 		case D_BMSAFEMAP:
3170 		case D_ALLOCDIRECT:
3171 		case D_ALLOCINDIR:
3172 			continue;
3173 
3174 		default:
3175 			panic("handle_disk_io_initiation: Unexpected type %s",
3176 			    TYPENAME(wk->wk_type));
3177 			/* NOTREACHED */
3178 		}
3179 	}
3180 }
3181 
3182 /*
3183  * Called from within the procedure above to deal with unsatisfied
3184  * allocation dependencies in a directory. The buffer must be locked,
3185  * thus, no I/O completion operations can occur while we are
3186  * manipulating its associated dependencies.
3187  */
3188 static void
3189 initiate_write_filepage(struct pagedep *pagedep, struct buf *bp)
3190 {
3191 	struct diradd *dap;
3192 	struct direct *ep;
3193 	int i;
3194 
3195 	if (pagedep->pd_state & IOSTARTED) {
3196 		/*
3197 		 * This can only happen if there is a driver that does not
3198 		 * understand chaining. Here biodone will reissue the call
3199 		 * to strategy for the incomplete buffers.
3200 		 */
3201 		kprintf("initiate_write_filepage: already started\n");
3202 		return;
3203 	}
3204 	pagedep->pd_state |= IOSTARTED;
3205 	ACQUIRE_LOCK(&lk);
3206 	for (i = 0; i < DAHASHSZ; i++) {
3207 		LIST_FOREACH(dap, &pagedep->pd_diraddhd[i], da_pdlist) {
3208 			ep = (struct direct *)
3209 			    ((char *)bp->b_data + dap->da_offset);
3210 			if (ep->d_ino != dap->da_newinum) {
3211 				FREE_LOCK(&lk);
3212 				panic("%s: dir inum %d != new %"PRId64,
3213 				    "initiate_write_filepage",
3214 				    ep->d_ino, dap->da_newinum);
3215 			}
3216 			if (dap->da_state & DIRCHG)
3217 				ep->d_ino = dap->da_previous->dm_oldinum;
3218 			else
3219 				ep->d_ino = 0;
3220 			dap->da_state &= ~ATTACHED;
3221 			dap->da_state |= UNDONE;
3222 		}
3223 	}
3224 	FREE_LOCK(&lk);
3225 }
3226 
3227 /*
3228  * Called from within the procedure above to deal with unsatisfied
3229  * allocation dependencies in an inodeblock. The buffer must be
3230  * locked, thus, no I/O completion operations can occur while we
3231  * are manipulating its associated dependencies.
3232  *
3233  * Parameters:
3234  *	bp:	The inode block
3235  */
3236 static void
3237 initiate_write_inodeblock(struct inodedep *inodedep, struct buf *bp)
3238 {
3239 	struct allocdirect *adp, *lastadp;
3240 	struct ufs1_dinode *dp;
3241 	struct ufs1_dinode *sip;
3242 	struct fs *fs;
3243 	ufs_lbn_t prevlbn = 0;
3244 	int i, deplist;
3245 
3246 	if (inodedep->id_state & IOSTARTED)
3247 		panic("initiate_write_inodeblock: already started");
3248 	inodedep->id_state |= IOSTARTED;
3249 	fs = inodedep->id_fs;
3250 	dp = (struct ufs1_dinode *)bp->b_data +
3251 	    ino_to_fsbo(fs, inodedep->id_ino);
3252 	/*
3253 	 * If the bitmap is not yet written, then the allocated
3254 	 * inode cannot be written to disk.
3255 	 */
3256 	if ((inodedep->id_state & DEPCOMPLETE) == 0) {
3257 		if (inodedep->id_savedino != NULL)
3258 			panic("initiate_write_inodeblock: already doing I/O");
3259 		MALLOC(sip, struct ufs1_dinode *,
3260 		    sizeof(struct ufs1_dinode), M_INODEDEP, M_SOFTDEP_FLAGS);
3261 		inodedep->id_savedino = sip;
3262 		*inodedep->id_savedino = *dp;
3263 		bzero((caddr_t)dp, sizeof(struct ufs1_dinode));
3264 		dp->di_gen = inodedep->id_savedino->di_gen;
3265 		return;
3266 	}
3267 	/*
3268 	 * If no dependencies, then there is nothing to roll back.
3269 	 */
3270 	inodedep->id_savedsize = dp->di_size;
3271 	if (TAILQ_FIRST(&inodedep->id_inoupdt) == NULL)
3272 		return;
3273 	/*
3274 	 * Set the dependencies to busy.
3275 	 */
3276 	ACQUIRE_LOCK(&lk);
3277 	for (deplist = 0, adp = TAILQ_FIRST(&inodedep->id_inoupdt); adp;
3278 	     adp = TAILQ_NEXT(adp, ad_next)) {
3279 #ifdef DIAGNOSTIC
3280 		if (deplist != 0 && prevlbn >= adp->ad_lbn) {
3281 			FREE_LOCK(&lk);
3282 			panic("softdep_write_inodeblock: lbn order");
3283 		}
3284 		prevlbn = adp->ad_lbn;
3285 		if (adp->ad_lbn < NDADDR &&
3286 		    dp->di_db[adp->ad_lbn] != adp->ad_newblkno) {
3287 			FREE_LOCK(&lk);
3288 			panic("%s: direct pointer #%ld mismatch %d != %d",
3289 			    "softdep_write_inodeblock", adp->ad_lbn,
3290 			    dp->di_db[adp->ad_lbn], adp->ad_newblkno);
3291 		}
3292 		if (adp->ad_lbn >= NDADDR &&
3293 		    dp->di_ib[adp->ad_lbn - NDADDR] != adp->ad_newblkno) {
3294 			FREE_LOCK(&lk);
3295 			panic("%s: indirect pointer #%ld mismatch %d != %d",
3296 			    "softdep_write_inodeblock", adp->ad_lbn - NDADDR,
3297 			    dp->di_ib[adp->ad_lbn - NDADDR], adp->ad_newblkno);
3298 		}
3299 		deplist |= 1 << adp->ad_lbn;
3300 		if ((adp->ad_state & ATTACHED) == 0) {
3301 			FREE_LOCK(&lk);
3302 			panic("softdep_write_inodeblock: Unknown state 0x%x",
3303 			    adp->ad_state);
3304 		}
3305 #endif /* DIAGNOSTIC */
3306 		adp->ad_state &= ~ATTACHED;
3307 		adp->ad_state |= UNDONE;
3308 	}
3309 	/*
3310 	 * The on-disk inode cannot claim to be any larger than the last
3311 	 * fragment that has been written. Otherwise, the on-disk inode
3312 	 * might have fragments that were not the last block in the file
3313 	 * which would corrupt the filesystem.
3314 	 */
3315 	for (lastadp = NULL, adp = TAILQ_FIRST(&inodedep->id_inoupdt); adp;
3316 	     lastadp = adp, adp = TAILQ_NEXT(adp, ad_next)) {
3317 		if (adp->ad_lbn >= NDADDR)
3318 			break;
3319 		dp->di_db[adp->ad_lbn] = adp->ad_oldblkno;
3320 		/* keep going until hitting a rollback to a frag */
3321 		if (adp->ad_oldsize == 0 || adp->ad_oldsize == fs->fs_bsize)
3322 			continue;
3323 		dp->di_size = fs->fs_bsize * adp->ad_lbn + adp->ad_oldsize;
3324 		for (i = adp->ad_lbn + 1; i < NDADDR; i++) {
3325 #ifdef DIAGNOSTIC
3326 			if (dp->di_db[i] != 0 && (deplist & (1 << i)) == 0) {
3327 				FREE_LOCK(&lk);
3328 				panic("softdep_write_inodeblock: lost dep1");
3329 			}
3330 #endif /* DIAGNOSTIC */
3331 			dp->di_db[i] = 0;
3332 		}
3333 		for (i = 0; i < NIADDR; i++) {
3334 #ifdef DIAGNOSTIC
3335 			if (dp->di_ib[i] != 0 &&
3336 			    (deplist & ((1 << NDADDR) << i)) == 0) {
3337 				FREE_LOCK(&lk);
3338 				panic("softdep_write_inodeblock: lost dep2");
3339 			}
3340 #endif /* DIAGNOSTIC */
3341 			dp->di_ib[i] = 0;
3342 		}
3343 		FREE_LOCK(&lk);
3344 		return;
3345 	}
3346 	/*
3347 	 * If we have zero'ed out the last allocated block of the file,
3348 	 * roll back the size to the last currently allocated block.
3349 	 * We know that this last allocated block is a full-sized as
3350 	 * we already checked for fragments in the loop above.
3351 	 */
3352 	if (lastadp != NULL &&
3353 	    dp->di_size <= (lastadp->ad_lbn + 1) * fs->fs_bsize) {
3354 		for (i = lastadp->ad_lbn; i >= 0; i--)
3355 			if (dp->di_db[i] != 0)
3356 				break;
3357 		dp->di_size = (i + 1) * fs->fs_bsize;
3358 	}
3359 	/*
3360 	 * The only dependencies are for indirect blocks.
3361 	 *
3362 	 * The file size for indirect block additions is not guaranteed.
3363 	 * Such a guarantee would be non-trivial to achieve. The conventional
3364 	 * synchronous write implementation also does not make this guarantee.
3365 	 * Fsck should catch and fix discrepancies. Arguably, the file size
3366 	 * can be over-estimated without destroying integrity when the file
3367 	 * moves into the indirect blocks (i.e., is large). If we want to
3368 	 * postpone fsck, we are stuck with this argument.
3369 	 */
3370 	for (; adp; adp = TAILQ_NEXT(adp, ad_next))
3371 		dp->di_ib[adp->ad_lbn - NDADDR] = 0;
3372 	FREE_LOCK(&lk);
3373 }
3374 
3375 /*
3376  * This routine is called during the completion interrupt
3377  * service routine for a disk write (from the procedure called
3378  * by the device driver to inform the filesystem caches of
3379  * a request completion).  It should be called early in this
3380  * procedure, before the block is made available to other
3381  * processes or other routines are called.
3382  *
3383  * Parameters:
3384  *	bp:	describes the completed disk write
3385  */
3386 static void
3387 softdep_disk_write_complete(struct buf *bp)
3388 {
3389 	struct worklist *wk;
3390 	struct workhead reattach;
3391 	struct newblk *newblk;
3392 	struct allocindir *aip;
3393 	struct allocdirect *adp;
3394 	struct indirdep *indirdep;
3395 	struct inodedep *inodedep;
3396 	struct bmsafemap *bmsafemap;
3397 
3398 #ifdef DEBUG
3399 	if (lk.lkt_held != NOHOLDER)
3400 		panic("softdep_disk_write_complete: lock is held");
3401 	lk.lkt_held = SPECIAL_FLAG;
3402 #endif
3403 	LIST_INIT(&reattach);
3404 	while ((wk = LIST_FIRST(&bp->b_dep)) != NULL) {
3405 		WORKLIST_REMOVE(wk);
3406 		switch (wk->wk_type) {
3407 
3408 		case D_PAGEDEP:
3409 			if (handle_written_filepage(WK_PAGEDEP(wk), bp))
3410 				WORKLIST_INSERT(&reattach, wk);
3411 			continue;
3412 
3413 		case D_INODEDEP:
3414 			if (handle_written_inodeblock(WK_INODEDEP(wk), bp))
3415 				WORKLIST_INSERT(&reattach, wk);
3416 			continue;
3417 
3418 		case D_BMSAFEMAP:
3419 			bmsafemap = WK_BMSAFEMAP(wk);
3420 			while ((newblk = LIST_FIRST(&bmsafemap->sm_newblkhd))) {
3421 				newblk->nb_state |= DEPCOMPLETE;
3422 				newblk->nb_bmsafemap = NULL;
3423 				LIST_REMOVE(newblk, nb_deps);
3424 			}
3425 			while ((adp =
3426 			   LIST_FIRST(&bmsafemap->sm_allocdirecthd))) {
3427 				adp->ad_state |= DEPCOMPLETE;
3428 				adp->ad_buf = NULL;
3429 				LIST_REMOVE(adp, ad_deps);
3430 				handle_allocdirect_partdone(adp);
3431 			}
3432 			while ((aip =
3433 			    LIST_FIRST(&bmsafemap->sm_allocindirhd))) {
3434 				aip->ai_state |= DEPCOMPLETE;
3435 				aip->ai_buf = NULL;
3436 				LIST_REMOVE(aip, ai_deps);
3437 				handle_allocindir_partdone(aip);
3438 			}
3439 			while ((inodedep =
3440 			     LIST_FIRST(&bmsafemap->sm_inodedephd)) != NULL) {
3441 				inodedep->id_state |= DEPCOMPLETE;
3442 				LIST_REMOVE(inodedep, id_deps);
3443 				inodedep->id_buf = NULL;
3444 			}
3445 			WORKITEM_FREE(bmsafemap, D_BMSAFEMAP);
3446 			continue;
3447 
3448 		case D_MKDIR:
3449 			handle_written_mkdir(WK_MKDIR(wk), MKDIR_BODY);
3450 			continue;
3451 
3452 		case D_ALLOCDIRECT:
3453 			adp = WK_ALLOCDIRECT(wk);
3454 			adp->ad_state |= COMPLETE;
3455 			handle_allocdirect_partdone(adp);
3456 			continue;
3457 
3458 		case D_ALLOCINDIR:
3459 			aip = WK_ALLOCINDIR(wk);
3460 			aip->ai_state |= COMPLETE;
3461 			handle_allocindir_partdone(aip);
3462 			continue;
3463 
3464 		case D_INDIRDEP:
3465 			indirdep = WK_INDIRDEP(wk);
3466 			if (indirdep->ir_state & GOINGAWAY) {
3467 				lk.lkt_held = NOHOLDER;
3468 				panic("disk_write_complete: indirdep gone");
3469 			}
3470 			bcopy(indirdep->ir_saveddata, bp->b_data, bp->b_bcount);
3471 			FREE(indirdep->ir_saveddata, M_INDIRDEP);
3472 			indirdep->ir_saveddata = 0;
3473 			indirdep->ir_state &= ~UNDONE;
3474 			indirdep->ir_state |= ATTACHED;
3475 			while ((aip = LIST_FIRST(&indirdep->ir_donehd)) != 0) {
3476 				handle_allocindir_partdone(aip);
3477 				if (aip == LIST_FIRST(&indirdep->ir_donehd)) {
3478 					lk.lkt_held = NOHOLDER;
3479 					panic("disk_write_complete: not gone");
3480 				}
3481 			}
3482 			WORKLIST_INSERT(&reattach, wk);
3483 			if ((bp->b_flags & B_DELWRI) == 0)
3484 				stat_indir_blk_ptrs++;
3485 			bdirty(bp);
3486 			continue;
3487 
3488 		default:
3489 			lk.lkt_held = NOHOLDER;
3490 			panic("handle_disk_write_complete: Unknown type %s",
3491 			    TYPENAME(wk->wk_type));
3492 			/* NOTREACHED */
3493 		}
3494 	}
3495 	/*
3496 	 * Reattach any requests that must be redone.
3497 	 */
3498 	while ((wk = LIST_FIRST(&reattach)) != NULL) {
3499 		WORKLIST_REMOVE(wk);
3500 		WORKLIST_INSERT_BP(bp, wk);
3501 	}
3502 #ifdef DEBUG
3503 	if (lk.lkt_held != SPECIAL_FLAG)
3504 		panic("softdep_disk_write_complete: lock lost");
3505 	lk.lkt_held = NOHOLDER;
3506 #endif
3507 }
3508 
3509 /*
3510  * Called from within softdep_disk_write_complete above. Note that
3511  * this routine is always called from interrupt level with further
3512  * splbio interrupts blocked.
3513  *
3514  * Parameters:
3515  *	adp:	the completed allocdirect
3516  */
3517 static void
3518 handle_allocdirect_partdone(struct allocdirect *adp)
3519 {
3520 	struct allocdirect *listadp;
3521 	struct inodedep *inodedep;
3522 	long bsize;
3523 
3524 	if ((adp->ad_state & ALLCOMPLETE) != ALLCOMPLETE)
3525 		return;
3526 	if (adp->ad_buf != NULL) {
3527 		lk.lkt_held = NOHOLDER;
3528 		panic("handle_allocdirect_partdone: dangling dep");
3529 	}
3530 	/*
3531 	 * The on-disk inode cannot claim to be any larger than the last
3532 	 * fragment that has been written. Otherwise, the on-disk inode
3533 	 * might have fragments that were not the last block in the file
3534 	 * which would corrupt the filesystem. Thus, we cannot free any
3535 	 * allocdirects after one whose ad_oldblkno claims a fragment as
3536 	 * these blocks must be rolled back to zero before writing the inode.
3537 	 * We check the currently active set of allocdirects in id_inoupdt.
3538 	 */
3539 	inodedep = adp->ad_inodedep;
3540 	bsize = inodedep->id_fs->fs_bsize;
3541 	TAILQ_FOREACH(listadp, &inodedep->id_inoupdt, ad_next) {
3542 		/* found our block */
3543 		if (listadp == adp)
3544 			break;
3545 		/* continue if ad_oldlbn is not a fragment */
3546 		if (listadp->ad_oldsize == 0 ||
3547 		    listadp->ad_oldsize == bsize)
3548 			continue;
3549 		/* hit a fragment */
3550 		return;
3551 	}
3552 	/*
3553 	 * If we have reached the end of the current list without
3554 	 * finding the just finished dependency, then it must be
3555 	 * on the future dependency list. Future dependencies cannot
3556 	 * be freed until they are moved to the current list.
3557 	 */
3558 	if (listadp == NULL) {
3559 #ifdef DEBUG
3560 		TAILQ_FOREACH(listadp, &inodedep->id_newinoupdt, ad_next)
3561 			/* found our block */
3562 			if (listadp == adp)
3563 				break;
3564 		if (listadp == NULL) {
3565 			lk.lkt_held = NOHOLDER;
3566 			panic("handle_allocdirect_partdone: lost dep");
3567 		}
3568 #endif /* DEBUG */
3569 		return;
3570 	}
3571 	/*
3572 	 * If we have found the just finished dependency, then free
3573 	 * it along with anything that follows it that is complete.
3574 	 */
3575 	for (; adp; adp = listadp) {
3576 		listadp = TAILQ_NEXT(adp, ad_next);
3577 		if ((adp->ad_state & ALLCOMPLETE) != ALLCOMPLETE)
3578 			return;
3579 		free_allocdirect(&inodedep->id_inoupdt, adp, 1);
3580 	}
3581 }
3582 
3583 /*
3584  * Called from within softdep_disk_write_complete above. Note that
3585  * this routine is always called from interrupt level with further
3586  * splbio interrupts blocked.
3587  *
3588  * Parameters:
3589  *	aip:	the completed allocindir
3590  */
3591 static void
3592 handle_allocindir_partdone(struct allocindir *aip)
3593 {
3594 	struct indirdep *indirdep;
3595 
3596 	if ((aip->ai_state & ALLCOMPLETE) != ALLCOMPLETE)
3597 		return;
3598 	if (aip->ai_buf != NULL) {
3599 		lk.lkt_held = NOHOLDER;
3600 		panic("handle_allocindir_partdone: dangling dependency");
3601 	}
3602 	indirdep = aip->ai_indirdep;
3603 	if (indirdep->ir_state & UNDONE) {
3604 		LIST_REMOVE(aip, ai_next);
3605 		LIST_INSERT_HEAD(&indirdep->ir_donehd, aip, ai_next);
3606 		return;
3607 	}
3608 	((ufs_daddr_t *)indirdep->ir_savebp->b_data)[aip->ai_offset] =
3609 	    aip->ai_newblkno;
3610 	LIST_REMOVE(aip, ai_next);
3611 	if (aip->ai_freefrag != NULL)
3612 		add_to_worklist(&aip->ai_freefrag->ff_list);
3613 	WORKITEM_FREE(aip, D_ALLOCINDIR);
3614 }
3615 
3616 /*
3617  * Called from within softdep_disk_write_complete above to restore
3618  * in-memory inode block contents to their most up-to-date state. Note
3619  * that this routine is always called from interrupt level with further
3620  * splbio interrupts blocked.
3621  *
3622  * Parameters:
3623  *	bp:	buffer containing the inode block
3624  */
3625 static int
3626 handle_written_inodeblock(struct inodedep *inodedep, struct buf *bp)
3627 {
3628 	struct worklist *wk, *filefree;
3629 	struct allocdirect *adp, *nextadp;
3630 	struct ufs1_dinode *dp;
3631 	int hadchanges;
3632 
3633 	if ((inodedep->id_state & IOSTARTED) == 0) {
3634 		lk.lkt_held = NOHOLDER;
3635 		panic("handle_written_inodeblock: not started");
3636 	}
3637 	inodedep->id_state &= ~IOSTARTED;
3638 	dp = (struct ufs1_dinode *)bp->b_data +
3639 	    ino_to_fsbo(inodedep->id_fs, inodedep->id_ino);
3640 	/*
3641 	 * If we had to rollback the inode allocation because of
3642 	 * bitmaps being incomplete, then simply restore it.
3643 	 * Keep the block dirty so that it will not be reclaimed until
3644 	 * all associated dependencies have been cleared and the
3645 	 * corresponding updates written to disk.
3646 	 */
3647 	if (inodedep->id_savedino != NULL) {
3648 		*dp = *inodedep->id_savedino;
3649 		FREE(inodedep->id_savedino, M_INODEDEP);
3650 		inodedep->id_savedino = NULL;
3651 		if ((bp->b_flags & B_DELWRI) == 0)
3652 			stat_inode_bitmap++;
3653 		bdirty(bp);
3654 		return (1);
3655 	}
3656 	inodedep->id_state |= COMPLETE;
3657 	/*
3658 	 * Roll forward anything that had to be rolled back before
3659 	 * the inode could be updated.
3660 	 */
3661 	hadchanges = 0;
3662 	for (adp = TAILQ_FIRST(&inodedep->id_inoupdt); adp; adp = nextadp) {
3663 		nextadp = TAILQ_NEXT(adp, ad_next);
3664 		if (adp->ad_state & ATTACHED) {
3665 			lk.lkt_held = NOHOLDER;
3666 			panic("handle_written_inodeblock: new entry");
3667 		}
3668 		if (adp->ad_lbn < NDADDR) {
3669 			if (dp->di_db[adp->ad_lbn] != adp->ad_oldblkno) {
3670 				lk.lkt_held = NOHOLDER;
3671 				panic("%s: %s #%ld mismatch %d != %d",
3672 				    "handle_written_inodeblock",
3673 				    "direct pointer", adp->ad_lbn,
3674 				    dp->di_db[adp->ad_lbn], adp->ad_oldblkno);
3675 			}
3676 			dp->di_db[adp->ad_lbn] = adp->ad_newblkno;
3677 		} else {
3678 			if (dp->di_ib[adp->ad_lbn - NDADDR] != 0) {
3679 				lk.lkt_held = NOHOLDER;
3680 				panic("%s: %s #%ld allocated as %d",
3681 				    "handle_written_inodeblock",
3682 				    "indirect pointer", adp->ad_lbn - NDADDR,
3683 				    dp->di_ib[adp->ad_lbn - NDADDR]);
3684 			}
3685 			dp->di_ib[adp->ad_lbn - NDADDR] = adp->ad_newblkno;
3686 		}
3687 		adp->ad_state &= ~UNDONE;
3688 		adp->ad_state |= ATTACHED;
3689 		hadchanges = 1;
3690 	}
3691 	if (hadchanges && (bp->b_flags & B_DELWRI) == 0)
3692 		stat_direct_blk_ptrs++;
3693 	/*
3694 	 * Reset the file size to its most up-to-date value.
3695 	 */
3696 	if (inodedep->id_savedsize == -1) {
3697 		lk.lkt_held = NOHOLDER;
3698 		panic("handle_written_inodeblock: bad size");
3699 	}
3700 	if (dp->di_size != inodedep->id_savedsize) {
3701 		dp->di_size = inodedep->id_savedsize;
3702 		hadchanges = 1;
3703 	}
3704 	inodedep->id_savedsize = -1;
3705 	/*
3706 	 * If there were any rollbacks in the inode block, then it must be
3707 	 * marked dirty so that its will eventually get written back in
3708 	 * its correct form.
3709 	 */
3710 	if (hadchanges)
3711 		bdirty(bp);
3712 	/*
3713 	 * Process any allocdirects that completed during the update.
3714 	 */
3715 	if ((adp = TAILQ_FIRST(&inodedep->id_inoupdt)) != NULL)
3716 		handle_allocdirect_partdone(adp);
3717 	/*
3718 	 * Process deallocations that were held pending until the
3719 	 * inode had been written to disk. Freeing of the inode
3720 	 * is delayed until after all blocks have been freed to
3721 	 * avoid creation of new <vfsid, inum, lbn> triples
3722 	 * before the old ones have been deleted.
3723 	 */
3724 	filefree = NULL;
3725 	while ((wk = LIST_FIRST(&inodedep->id_bufwait)) != NULL) {
3726 		WORKLIST_REMOVE(wk);
3727 		switch (wk->wk_type) {
3728 
3729 		case D_FREEFILE:
3730 			/*
3731 			 * We defer adding filefree to the worklist until
3732 			 * all other additions have been made to ensure
3733 			 * that it will be done after all the old blocks
3734 			 * have been freed.
3735 			 */
3736 			if (filefree != NULL) {
3737 				lk.lkt_held = NOHOLDER;
3738 				panic("handle_written_inodeblock: filefree");
3739 			}
3740 			filefree = wk;
3741 			continue;
3742 
3743 		case D_MKDIR:
3744 			handle_written_mkdir(WK_MKDIR(wk), MKDIR_PARENT);
3745 			continue;
3746 
3747 		case D_DIRADD:
3748 			diradd_inode_written(WK_DIRADD(wk), inodedep);
3749 			continue;
3750 
3751 		case D_FREEBLKS:
3752 			wk->wk_state |= COMPLETE;
3753 			if ((wk->wk_state  & ALLCOMPLETE) != ALLCOMPLETE)
3754 				continue;
3755 			/* -- fall through -- */
3756 		case D_FREEFRAG:
3757 		case D_DIRREM:
3758 			add_to_worklist(wk);
3759 			continue;
3760 
3761 		default:
3762 			lk.lkt_held = NOHOLDER;
3763 			panic("handle_written_inodeblock: Unknown type %s",
3764 			    TYPENAME(wk->wk_type));
3765 			/* NOTREACHED */
3766 		}
3767 	}
3768 	if (filefree != NULL) {
3769 		if (free_inodedep(inodedep) == 0) {
3770 			lk.lkt_held = NOHOLDER;
3771 			panic("handle_written_inodeblock: live inodedep");
3772 		}
3773 		add_to_worklist(filefree);
3774 		return (0);
3775 	}
3776 
3777 	/*
3778 	 * If no outstanding dependencies, free it.
3779 	 */
3780 	if (free_inodedep(inodedep) || TAILQ_FIRST(&inodedep->id_inoupdt) == 0)
3781 		return (0);
3782 	return (hadchanges);
3783 }
3784 
3785 /*
3786  * Process a diradd entry after its dependent inode has been written.
3787  * This routine must be called with splbio interrupts blocked.
3788  */
3789 static void
3790 diradd_inode_written(struct diradd *dap, struct inodedep *inodedep)
3791 {
3792 	struct pagedep *pagedep;
3793 
3794 	dap->da_state |= COMPLETE;
3795 	if ((dap->da_state & ALLCOMPLETE) == ALLCOMPLETE) {
3796 		if (dap->da_state & DIRCHG)
3797 			pagedep = dap->da_previous->dm_pagedep;
3798 		else
3799 			pagedep = dap->da_pagedep;
3800 		LIST_REMOVE(dap, da_pdlist);
3801 		LIST_INSERT_HEAD(&pagedep->pd_pendinghd, dap, da_pdlist);
3802 	}
3803 	WORKLIST_INSERT(&inodedep->id_pendinghd, &dap->da_list);
3804 }
3805 
3806 /*
3807  * Handle the completion of a mkdir dependency.
3808  */
3809 static void
3810 handle_written_mkdir(struct mkdir *mkdir, int type)
3811 {
3812 	struct diradd *dap;
3813 	struct pagedep *pagedep;
3814 
3815 	if (mkdir->md_state != type) {
3816 		lk.lkt_held = NOHOLDER;
3817 		panic("handle_written_mkdir: bad type");
3818 	}
3819 	dap = mkdir->md_diradd;
3820 	dap->da_state &= ~type;
3821 	if ((dap->da_state & (MKDIR_PARENT | MKDIR_BODY)) == 0)
3822 		dap->da_state |= DEPCOMPLETE;
3823 	if ((dap->da_state & ALLCOMPLETE) == ALLCOMPLETE) {
3824 		if (dap->da_state & DIRCHG)
3825 			pagedep = dap->da_previous->dm_pagedep;
3826 		else
3827 			pagedep = dap->da_pagedep;
3828 		LIST_REMOVE(dap, da_pdlist);
3829 		LIST_INSERT_HEAD(&pagedep->pd_pendinghd, dap, da_pdlist);
3830 	}
3831 	LIST_REMOVE(mkdir, md_mkdirs);
3832 	WORKITEM_FREE(mkdir, D_MKDIR);
3833 }
3834 
3835 /*
3836  * Called from within softdep_disk_write_complete above.
3837  * A write operation was just completed. Removed inodes can
3838  * now be freed and associated block pointers may be committed.
3839  * Note that this routine is always called from interrupt level
3840  * with further splbio interrupts blocked.
3841  *
3842  * Parameters:
3843  *	bp:	buffer containing the written page
3844  */
3845 static int
3846 handle_written_filepage(struct pagedep *pagedep, struct buf *bp)
3847 {
3848 	struct dirrem *dirrem;
3849 	struct diradd *dap, *nextdap;
3850 	struct direct *ep;
3851 	int i, chgs;
3852 
3853 	if ((pagedep->pd_state & IOSTARTED) == 0) {
3854 		lk.lkt_held = NOHOLDER;
3855 		panic("handle_written_filepage: not started");
3856 	}
3857 	pagedep->pd_state &= ~IOSTARTED;
3858 	/*
3859 	 * Process any directory removals that have been committed.
3860 	 */
3861 	while ((dirrem = LIST_FIRST(&pagedep->pd_dirremhd)) != NULL) {
3862 		LIST_REMOVE(dirrem, dm_next);
3863 		dirrem->dm_dirinum = pagedep->pd_ino;
3864 		add_to_worklist(&dirrem->dm_list);
3865 	}
3866 	/*
3867 	 * Free any directory additions that have been committed.
3868 	 */
3869 	while ((dap = LIST_FIRST(&pagedep->pd_pendinghd)) != NULL)
3870 		free_diradd(dap);
3871 	/*
3872 	 * Uncommitted directory entries must be restored.
3873 	 */
3874 	for (chgs = 0, i = 0; i < DAHASHSZ; i++) {
3875 		for (dap = LIST_FIRST(&pagedep->pd_diraddhd[i]); dap;
3876 		     dap = nextdap) {
3877 			nextdap = LIST_NEXT(dap, da_pdlist);
3878 			if (dap->da_state & ATTACHED) {
3879 				lk.lkt_held = NOHOLDER;
3880 				panic("handle_written_filepage: attached");
3881 			}
3882 			ep = (struct direct *)
3883 			    ((char *)bp->b_data + dap->da_offset);
3884 			ep->d_ino = dap->da_newinum;
3885 			dap->da_state &= ~UNDONE;
3886 			dap->da_state |= ATTACHED;
3887 			chgs = 1;
3888 			/*
3889 			 * If the inode referenced by the directory has
3890 			 * been written out, then the dependency can be
3891 			 * moved to the pending list.
3892 			 */
3893 			if ((dap->da_state & ALLCOMPLETE) == ALLCOMPLETE) {
3894 				LIST_REMOVE(dap, da_pdlist);
3895 				LIST_INSERT_HEAD(&pagedep->pd_pendinghd, dap,
3896 				    da_pdlist);
3897 			}
3898 		}
3899 	}
3900 	/*
3901 	 * If there were any rollbacks in the directory, then it must be
3902 	 * marked dirty so that its will eventually get written back in
3903 	 * its correct form.
3904 	 */
3905 	if (chgs) {
3906 		if ((bp->b_flags & B_DELWRI) == 0)
3907 			stat_dir_entry++;
3908 		bdirty(bp);
3909 	}
3910 	/*
3911 	 * If no dependencies remain, the pagedep will be freed.
3912 	 * Otherwise it will remain to update the page before it
3913 	 * is written back to disk.
3914 	 */
3915 	if (LIST_FIRST(&pagedep->pd_pendinghd) == 0) {
3916 		for (i = 0; i < DAHASHSZ; i++)
3917 			if (LIST_FIRST(&pagedep->pd_diraddhd[i]) != NULL)
3918 				break;
3919 		if (i == DAHASHSZ) {
3920 			LIST_REMOVE(pagedep, pd_hash);
3921 			WORKITEM_FREE(pagedep, D_PAGEDEP);
3922 			return (0);
3923 		}
3924 	}
3925 	return (1);
3926 }
3927 
3928 /*
3929  * Writing back in-core inode structures.
3930  *
3931  * The filesystem only accesses an inode's contents when it occupies an
3932  * "in-core" inode structure.  These "in-core" structures are separate from
3933  * the page frames used to cache inode blocks.  Only the latter are
3934  * transferred to/from the disk.  So, when the updated contents of the
3935  * "in-core" inode structure are copied to the corresponding in-memory inode
3936  * block, the dependencies are also transferred.  The following procedure is
3937  * called when copying a dirty "in-core" inode to a cached inode block.
3938  */
3939 
3940 /*
3941  * Called when an inode is loaded from disk. If the effective link count
3942  * differed from the actual link count when it was last flushed, then we
3943  * need to ensure that the correct effective link count is put back.
3944  *
3945  * Parameters:
3946  *	ip:	the "in_core" copy of the inode
3947  */
3948 void
3949 softdep_load_inodeblock(struct inode *ip)
3950 {
3951 	struct inodedep *inodedep;
3952 
3953 	/*
3954 	 * Check for alternate nlink count.
3955 	 */
3956 	ip->i_effnlink = ip->i_nlink;
3957 	ACQUIRE_LOCK(&lk);
3958 	if (inodedep_lookup(ip->i_fs, ip->i_number, 0, &inodedep) == 0) {
3959 		FREE_LOCK(&lk);
3960 		return;
3961 	}
3962 	ip->i_effnlink -= inodedep->id_nlinkdelta;
3963 	FREE_LOCK(&lk);
3964 }
3965 
3966 /*
3967  * This routine is called just before the "in-core" inode
3968  * information is to be copied to the in-memory inode block.
3969  * Recall that an inode block contains several inodes. If
3970  * the force flag is set, then the dependencies will be
3971  * cleared so that the update can always be made. Note that
3972  * the buffer is locked when this routine is called, so we
3973  * will never be in the middle of writing the inode block
3974  * to disk.
3975  *
3976  * Parameters:
3977  *	ip:		the "in_core" copy of the inode
3978  *	bp:		the buffer containing the inode block
3979  *	waitfor:	nonzero => update must be allowed
3980  */
3981 void
3982 softdep_update_inodeblock(struct inode *ip, struct buf *bp,
3983 			  int waitfor)
3984 {
3985 	struct inodedep *inodedep;
3986 	struct worklist *wk;
3987 	int error, gotit;
3988 
3989 	/*
3990 	 * If the effective link count is not equal to the actual link
3991 	 * count, then we must track the difference in an inodedep while
3992 	 * the inode is (potentially) tossed out of the cache. Otherwise,
3993 	 * if there is no existing inodedep, then there are no dependencies
3994 	 * to track.
3995 	 */
3996 	ACQUIRE_LOCK(&lk);
3997 	if (inodedep_lookup(ip->i_fs, ip->i_number, 0, &inodedep) == 0) {
3998 		FREE_LOCK(&lk);
3999 		if (ip->i_effnlink != ip->i_nlink)
4000 			panic("softdep_update_inodeblock: bad link count");
4001 		return;
4002 	}
4003 	if (inodedep->id_nlinkdelta != ip->i_nlink - ip->i_effnlink) {
4004 		FREE_LOCK(&lk);
4005 		panic("softdep_update_inodeblock: bad delta");
4006 	}
4007 	/*
4008 	 * Changes have been initiated. Anything depending on these
4009 	 * changes cannot occur until this inode has been written.
4010 	 */
4011 	inodedep->id_state &= ~COMPLETE;
4012 	if ((inodedep->id_state & ONWORKLIST) == 0)
4013 		WORKLIST_INSERT_BP(bp, &inodedep->id_list);
4014 	/*
4015 	 * Any new dependencies associated with the incore inode must
4016 	 * now be moved to the list associated with the buffer holding
4017 	 * the in-memory copy of the inode. Once merged process any
4018 	 * allocdirects that are completed by the merger.
4019 	 */
4020 	merge_inode_lists(inodedep);
4021 	if (TAILQ_FIRST(&inodedep->id_inoupdt) != NULL)
4022 		handle_allocdirect_partdone(TAILQ_FIRST(&inodedep->id_inoupdt));
4023 	/*
4024 	 * Now that the inode has been pushed into the buffer, the
4025 	 * operations dependent on the inode being written to disk
4026 	 * can be moved to the id_bufwait so that they will be
4027 	 * processed when the buffer I/O completes.
4028 	 */
4029 	while ((wk = LIST_FIRST(&inodedep->id_inowait)) != NULL) {
4030 		WORKLIST_REMOVE(wk);
4031 		WORKLIST_INSERT(&inodedep->id_bufwait, wk);
4032 	}
4033 	/*
4034 	 * Newly allocated inodes cannot be written until the bitmap
4035 	 * that allocates them have been written (indicated by
4036 	 * DEPCOMPLETE being set in id_state). If we are doing a
4037 	 * forced sync (e.g., an fsync on a file), we force the bitmap
4038 	 * to be written so that the update can be done.
4039 	 */
4040 	if ((inodedep->id_state & DEPCOMPLETE) != 0 || waitfor == 0) {
4041 		FREE_LOCK(&lk);
4042 		return;
4043 	}
4044 	gotit = getdirtybuf(&inodedep->id_buf, MNT_WAIT);
4045 	FREE_LOCK(&lk);
4046 	if (gotit &&
4047 	    (error = bwrite(inodedep->id_buf)) != 0)
4048 		softdep_error("softdep_update_inodeblock: bwrite", error);
4049 }
4050 
4051 /*
4052  * Merge the new inode dependency list (id_newinoupdt) into the old
4053  * inode dependency list (id_inoupdt). This routine must be called
4054  * with splbio interrupts blocked.
4055  */
4056 static void
4057 merge_inode_lists(struct inodedep *inodedep)
4058 {
4059 	struct allocdirect *listadp, *newadp;
4060 
4061 	newadp = TAILQ_FIRST(&inodedep->id_newinoupdt);
4062 	for (listadp = TAILQ_FIRST(&inodedep->id_inoupdt); listadp && newadp;) {
4063 		if (listadp->ad_lbn < newadp->ad_lbn) {
4064 			listadp = TAILQ_NEXT(listadp, ad_next);
4065 			continue;
4066 		}
4067 		TAILQ_REMOVE(&inodedep->id_newinoupdt, newadp, ad_next);
4068 		TAILQ_INSERT_BEFORE(listadp, newadp, ad_next);
4069 		if (listadp->ad_lbn == newadp->ad_lbn) {
4070 			allocdirect_merge(&inodedep->id_inoupdt, newadp,
4071 			    listadp);
4072 			listadp = newadp;
4073 		}
4074 		newadp = TAILQ_FIRST(&inodedep->id_newinoupdt);
4075 	}
4076 	while ((newadp = TAILQ_FIRST(&inodedep->id_newinoupdt)) != NULL) {
4077 		TAILQ_REMOVE(&inodedep->id_newinoupdt, newadp, ad_next);
4078 		TAILQ_INSERT_TAIL(&inodedep->id_inoupdt, newadp, ad_next);
4079 	}
4080 }
4081 
4082 /*
4083  * If we are doing an fsync, then we must ensure that any directory
4084  * entries for the inode have been written after the inode gets to disk.
4085  *
4086  * Parameters:
4087  *	vp:	the "in_core" copy of the inode
4088  */
4089 static int
4090 softdep_fsync(struct vnode *vp)
4091 {
4092 	struct inodedep *inodedep;
4093 	struct pagedep *pagedep;
4094 	struct worklist *wk;
4095 	struct diradd *dap;
4096 	struct mount *mnt;
4097 	struct vnode *pvp;
4098 	struct inode *ip;
4099 	struct buf *bp;
4100 	struct fs *fs;
4101 	int error, flushparent;
4102 	ino_t parentino;
4103 	ufs_lbn_t lbn;
4104 
4105 	/*
4106 	 * Move check from original kernel code, possibly not needed any
4107 	 * more with the per-mount bioops.
4108 	 */
4109 	if ((vp->v_mount->mnt_flag & MNT_SOFTDEP) == 0)
4110 		return (0);
4111 
4112 	ip = VTOI(vp);
4113 	fs = ip->i_fs;
4114 	ACQUIRE_LOCK(&lk);
4115 	if (inodedep_lookup(fs, ip->i_number, 0, &inodedep) == 0) {
4116 		FREE_LOCK(&lk);
4117 		return (0);
4118 	}
4119 	if (LIST_FIRST(&inodedep->id_inowait) != NULL ||
4120 	    LIST_FIRST(&inodedep->id_bufwait) != NULL ||
4121 	    TAILQ_FIRST(&inodedep->id_inoupdt) != NULL ||
4122 	    TAILQ_FIRST(&inodedep->id_newinoupdt) != NULL) {
4123 		FREE_LOCK(&lk);
4124 		panic("softdep_fsync: pending ops");
4125 	}
4126 	for (error = 0, flushparent = 0; ; ) {
4127 		if ((wk = LIST_FIRST(&inodedep->id_pendinghd)) == NULL)
4128 			break;
4129 		if (wk->wk_type != D_DIRADD) {
4130 			FREE_LOCK(&lk);
4131 			panic("softdep_fsync: Unexpected type %s",
4132 			    TYPENAME(wk->wk_type));
4133 		}
4134 		dap = WK_DIRADD(wk);
4135 		/*
4136 		 * Flush our parent if this directory entry
4137 		 * has a MKDIR_PARENT dependency.
4138 		 */
4139 		if (dap->da_state & DIRCHG)
4140 			pagedep = dap->da_previous->dm_pagedep;
4141 		else
4142 			pagedep = dap->da_pagedep;
4143 		mnt = pagedep->pd_mnt;
4144 		parentino = pagedep->pd_ino;
4145 		lbn = pagedep->pd_lbn;
4146 		if ((dap->da_state & (MKDIR_BODY | COMPLETE)) != COMPLETE) {
4147 			FREE_LOCK(&lk);
4148 			panic("softdep_fsync: dirty");
4149 		}
4150 		flushparent = dap->da_state & MKDIR_PARENT;
4151 		/*
4152 		 * If we are being fsync'ed as part of vgone'ing this vnode,
4153 		 * then we will not be able to release and recover the
4154 		 * vnode below, so we just have to give up on writing its
4155 		 * directory entry out. It will eventually be written, just
4156 		 * not now, but then the user was not asking to have it
4157 		 * written, so we are not breaking any promises.
4158 		 */
4159 		if (vp->v_flag & VRECLAIMED)
4160 			break;
4161 		/*
4162 		 * We prevent deadlock by always fetching inodes from the
4163 		 * root, moving down the directory tree. Thus, when fetching
4164 		 * our parent directory, we must unlock ourselves before
4165 		 * requesting the lock on our parent. See the comment in
4166 		 * ufs_lookup for details on possible races.
4167 		 */
4168 		FREE_LOCK(&lk);
4169 		vn_unlock(vp);
4170 		error = VFS_VGET(mnt, parentino, &pvp);
4171 		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
4172 		if (error != 0)
4173 			return (error);
4174 		if (flushparent) {
4175 			if ((error = ffs_update(pvp, 1)) != 0) {
4176 				vput(pvp);
4177 				return (error);
4178 			}
4179 		}
4180 		/*
4181 		 * Flush directory page containing the inode's name.
4182 		 */
4183 		error = bread(pvp, lblktodoff(fs, lbn), blksize(fs, VTOI(pvp), lbn), &bp);
4184 		if (error == 0)
4185 			error = bwrite(bp);
4186 		vput(pvp);
4187 		if (error != 0)
4188 			return (error);
4189 		ACQUIRE_LOCK(&lk);
4190 		if (inodedep_lookup(fs, ip->i_number, 0, &inodedep) == 0)
4191 			break;
4192 	}
4193 	FREE_LOCK(&lk);
4194 	return (0);
4195 }
4196 
4197 /*
4198  * Flush all the dirty bitmaps associated with the block device
4199  * before flushing the rest of the dirty blocks so as to reduce
4200  * the number of dependencies that will have to be rolled back.
4201  */
4202 static int softdep_fsync_mountdev_bp(struct buf *bp, void *data);
4203 
4204 void
4205 softdep_fsync_mountdev(struct vnode *vp)
4206 {
4207 	if (!vn_isdisk(vp, NULL))
4208 		panic("softdep_fsync_mountdev: vnode not a disk");
4209 	ACQUIRE_LOCK(&lk);
4210 	RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree, NULL,
4211 		softdep_fsync_mountdev_bp, vp);
4212 	drain_output(vp, 1);
4213 	FREE_LOCK(&lk);
4214 }
4215 
4216 static int
4217 softdep_fsync_mountdev_bp(struct buf *bp, void *data)
4218 {
4219 	struct worklist *wk;
4220 	struct vnode *vp = data;
4221 
4222 	/*
4223 	 * If it is already scheduled, skip to the next buffer.
4224 	 */
4225 	if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT))
4226 		return(0);
4227 	if (bp->b_vp != vp || (bp->b_flags & B_DELWRI) == 0) {
4228 		BUF_UNLOCK(bp);
4229 		kprintf("softdep_fsync_mountdev_bp: warning, buffer %p ripped out from under vnode %p\n", bp, vp);
4230 		return(0);
4231 	}
4232 	/*
4233 	 * We are only interested in bitmaps with outstanding
4234 	 * dependencies.
4235 	 */
4236 	if ((wk = LIST_FIRST(&bp->b_dep)) == NULL ||
4237 	    wk->wk_type != D_BMSAFEMAP) {
4238 		BUF_UNLOCK(bp);
4239 		return(0);
4240 	}
4241 	bremfree(bp);
4242 	FREE_LOCK(&lk);
4243 	(void) bawrite(bp);
4244 	ACQUIRE_LOCK(&lk);
4245 	return(0);
4246 }
4247 
4248 /*
4249  * This routine is called when we are trying to synchronously flush a
4250  * file. This routine must eliminate any filesystem metadata dependencies
4251  * so that the syncing routine can succeed by pushing the dirty blocks
4252  * associated with the file. If any I/O errors occur, they are returned.
4253  */
4254 struct softdep_sync_metadata_info {
4255 	struct vnode *vp;
4256 	int waitfor;
4257 };
4258 
4259 static int softdep_sync_metadata_bp(struct buf *bp, void *data);
4260 
4261 int
4262 softdep_sync_metadata(struct vnode *vp, struct thread *td)
4263 {
4264 	struct softdep_sync_metadata_info info;
4265 	int error, waitfor;
4266 
4267 	/*
4268 	 * Check whether this vnode is involved in a filesystem
4269 	 * that is doing soft dependency processing.
4270 	 */
4271 	if (!vn_isdisk(vp, NULL)) {
4272 		if (!DOINGSOFTDEP(vp))
4273 			return (0);
4274 	} else
4275 		if (vp->v_rdev->si_mountpoint == NULL ||
4276 		    (vp->v_rdev->si_mountpoint->mnt_flag & MNT_SOFTDEP) == 0)
4277 			return (0);
4278 	/*
4279 	 * Ensure that any direct block dependencies have been cleared.
4280 	 */
4281 	ACQUIRE_LOCK(&lk);
4282 	if ((error = flush_inodedep_deps(VTOI(vp)->i_fs, VTOI(vp)->i_number))) {
4283 		FREE_LOCK(&lk);
4284 		return (error);
4285 	}
4286 	/*
4287 	 * For most files, the only metadata dependencies are the
4288 	 * cylinder group maps that allocate their inode or blocks.
4289 	 * The block allocation dependencies can be found by traversing
4290 	 * the dependency lists for any buffers that remain on their
4291 	 * dirty buffer list. The inode allocation dependency will
4292 	 * be resolved when the inode is updated with MNT_WAIT.
4293 	 * This work is done in two passes. The first pass grabs most
4294 	 * of the buffers and begins asynchronously writing them. The
4295 	 * only way to wait for these asynchronous writes is to sleep
4296 	 * on the filesystem vnode which may stay busy for a long time
4297 	 * if the filesystem is active. So, instead, we make a second
4298 	 * pass over the dependencies blocking on each write. In the
4299 	 * usual case we will be blocking against a write that we
4300 	 * initiated, so when it is done the dependency will have been
4301 	 * resolved. Thus the second pass is expected to end quickly.
4302 	 */
4303 	waitfor = MNT_NOWAIT;
4304 top:
4305 	/*
4306 	 * We must wait for any I/O in progress to finish so that
4307 	 * all potential buffers on the dirty list will be visible.
4308 	 */
4309 	drain_output(vp, 1);
4310 	info.vp = vp;
4311 	info.waitfor = waitfor;
4312 	error = RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree, NULL,
4313 			softdep_sync_metadata_bp, &info);
4314 	if (error < 0) {
4315 		FREE_LOCK(&lk);
4316 		return(-error);	/* error code */
4317 	}
4318 
4319 	/*
4320 	 * The brief unlock is to allow any pent up dependency
4321 	 * processing to be done.  Then proceed with the second pass.
4322 	 */
4323 	if (waitfor == MNT_NOWAIT) {
4324 		waitfor = MNT_WAIT;
4325 		FREE_LOCK(&lk);
4326 		ACQUIRE_LOCK(&lk);
4327 		goto top;
4328 	}
4329 
4330 	/*
4331 	 * If we have managed to get rid of all the dirty buffers,
4332 	 * then we are done. For certain directories and block
4333 	 * devices, we may need to do further work.
4334 	 *
4335 	 * We must wait for any I/O in progress to finish so that
4336 	 * all potential buffers on the dirty list will be visible.
4337 	 */
4338 	drain_output(vp, 1);
4339 	if (RB_EMPTY(&vp->v_rbdirty_tree)) {
4340 		FREE_LOCK(&lk);
4341 		return (0);
4342 	}
4343 
4344 	FREE_LOCK(&lk);
4345 	/*
4346 	 * If we are trying to sync a block device, some of its buffers may
4347 	 * contain metadata that cannot be written until the contents of some
4348 	 * partially written files have been written to disk. The only easy
4349 	 * way to accomplish this is to sync the entire filesystem (luckily
4350 	 * this happens rarely).
4351 	 */
4352 	if (vn_isdisk(vp, NULL) &&
4353 	    vp->v_rdev &&
4354 	    vp->v_rdev->si_mountpoint && !vn_islocked(vp) &&
4355 	    (error = VFS_SYNC(vp->v_rdev->si_mountpoint, MNT_WAIT)) != 0)
4356 		return (error);
4357 	return (0);
4358 }
4359 
4360 static int
4361 softdep_sync_metadata_bp(struct buf *bp, void *data)
4362 {
4363 	struct softdep_sync_metadata_info *info = data;
4364 	struct pagedep *pagedep;
4365 	struct allocdirect *adp;
4366 	struct allocindir *aip;
4367 	struct worklist *wk;
4368 	struct buf *nbp;
4369 	int error;
4370 	int i;
4371 
4372 	if (getdirtybuf(&bp, MNT_WAIT) == 0) {
4373 		kprintf("softdep_sync_metadata_bp(1): caught buf %p going away\n", bp);
4374 		return (1);
4375 	}
4376 	if (bp->b_vp != info->vp || (bp->b_flags & B_DELWRI) == 0) {
4377 		kprintf("softdep_sync_metadata_bp(2): caught buf %p going away vp %p\n", bp, info->vp);
4378 		BUF_UNLOCK(bp);
4379 		return(1);
4380 	}
4381 
4382 	/*
4383 	 * As we hold the buffer locked, none of its dependencies
4384 	 * will disappear.
4385 	 */
4386 	LIST_FOREACH(wk, &bp->b_dep, wk_list) {
4387 		switch (wk->wk_type) {
4388 
4389 		case D_ALLOCDIRECT:
4390 			adp = WK_ALLOCDIRECT(wk);
4391 			if (adp->ad_state & DEPCOMPLETE)
4392 				break;
4393 			nbp = adp->ad_buf;
4394 			if (getdirtybuf(&nbp, info->waitfor) == 0)
4395 				break;
4396 			FREE_LOCK(&lk);
4397 			if (info->waitfor == MNT_NOWAIT) {
4398 				bawrite(nbp);
4399 			} else if ((error = bwrite(nbp)) != 0) {
4400 				bawrite(bp);
4401 				ACQUIRE_LOCK(&lk);
4402 				return (-error);
4403 			}
4404 			ACQUIRE_LOCK(&lk);
4405 			break;
4406 
4407 		case D_ALLOCINDIR:
4408 			aip = WK_ALLOCINDIR(wk);
4409 			if (aip->ai_state & DEPCOMPLETE)
4410 				break;
4411 			nbp = aip->ai_buf;
4412 			if (getdirtybuf(&nbp, info->waitfor) == 0)
4413 				break;
4414 			FREE_LOCK(&lk);
4415 			if (info->waitfor == MNT_NOWAIT) {
4416 				bawrite(nbp);
4417 			} else if ((error = bwrite(nbp)) != 0) {
4418 				bawrite(bp);
4419 				ACQUIRE_LOCK(&lk);
4420 				return (-error);
4421 			}
4422 			ACQUIRE_LOCK(&lk);
4423 			break;
4424 
4425 		case D_INDIRDEP:
4426 		restart:
4427 
4428 			LIST_FOREACH(aip, &WK_INDIRDEP(wk)->ir_deplisthd, ai_next) {
4429 				if (aip->ai_state & DEPCOMPLETE)
4430 					continue;
4431 				nbp = aip->ai_buf;
4432 				if (getdirtybuf(&nbp, MNT_WAIT) == 0)
4433 					goto restart;
4434 				FREE_LOCK(&lk);
4435 				if ((error = bwrite(nbp)) != 0) {
4436 					bawrite(bp);
4437 					ACQUIRE_LOCK(&lk);
4438 					return (-error);
4439 				}
4440 				ACQUIRE_LOCK(&lk);
4441 				goto restart;
4442 			}
4443 			break;
4444 
4445 		case D_INODEDEP:
4446 			if ((error = flush_inodedep_deps(WK_INODEDEP(wk)->id_fs,
4447 			    WK_INODEDEP(wk)->id_ino)) != 0) {
4448 				FREE_LOCK(&lk);
4449 				bawrite(bp);
4450 				ACQUIRE_LOCK(&lk);
4451 				return (-error);
4452 			}
4453 			break;
4454 
4455 		case D_PAGEDEP:
4456 			/*
4457 			 * We are trying to sync a directory that may
4458 			 * have dependencies on both its own metadata
4459 			 * and/or dependencies on the inodes of any
4460 			 * recently allocated files. We walk its diradd
4461 			 * lists pushing out the associated inode.
4462 			 */
4463 			pagedep = WK_PAGEDEP(wk);
4464 			for (i = 0; i < DAHASHSZ; i++) {
4465 				if (LIST_FIRST(&pagedep->pd_diraddhd[i]) == 0)
4466 					continue;
4467 				if ((error =
4468 				    flush_pagedep_deps(info->vp,
4469 						pagedep->pd_mnt,
4470 						&pagedep->pd_diraddhd[i]))) {
4471 					FREE_LOCK(&lk);
4472 					bawrite(bp);
4473 					ACQUIRE_LOCK(&lk);
4474 					return (-error);
4475 				}
4476 			}
4477 			break;
4478 
4479 		case D_MKDIR:
4480 			/*
4481 			 * This case should never happen if the vnode has
4482 			 * been properly sync'ed. However, if this function
4483 			 * is used at a place where the vnode has not yet
4484 			 * been sync'ed, this dependency can show up. So,
4485 			 * rather than panic, just flush it.
4486 			 */
4487 			nbp = WK_MKDIR(wk)->md_buf;
4488 			if (getdirtybuf(&nbp, info->waitfor) == 0)
4489 				break;
4490 			FREE_LOCK(&lk);
4491 			if (info->waitfor == MNT_NOWAIT) {
4492 				bawrite(nbp);
4493 			} else if ((error = bwrite(nbp)) != 0) {
4494 				bawrite(bp);
4495 				ACQUIRE_LOCK(&lk);
4496 				return (-error);
4497 			}
4498 			ACQUIRE_LOCK(&lk);
4499 			break;
4500 
4501 		case D_BMSAFEMAP:
4502 			/*
4503 			 * This case should never happen if the vnode has
4504 			 * been properly sync'ed. However, if this function
4505 			 * is used at a place where the vnode has not yet
4506 			 * been sync'ed, this dependency can show up. So,
4507 			 * rather than panic, just flush it.
4508 			 *
4509 			 * nbp can wind up == bp if a device node for the
4510 			 * same filesystem is being fsynced at the same time,
4511 			 * leading to a panic if we don't catch the case.
4512 			 */
4513 			nbp = WK_BMSAFEMAP(wk)->sm_buf;
4514 			if (nbp == bp)
4515 				break;
4516 			if (getdirtybuf(&nbp, info->waitfor) == 0)
4517 				break;
4518 			FREE_LOCK(&lk);
4519 			if (info->waitfor == MNT_NOWAIT) {
4520 				bawrite(nbp);
4521 			} else if ((error = bwrite(nbp)) != 0) {
4522 				bawrite(bp);
4523 				ACQUIRE_LOCK(&lk);
4524 				return (-error);
4525 			}
4526 			ACQUIRE_LOCK(&lk);
4527 			break;
4528 
4529 		default:
4530 			FREE_LOCK(&lk);
4531 			panic("softdep_sync_metadata: Unknown type %s",
4532 			    TYPENAME(wk->wk_type));
4533 			/* NOTREACHED */
4534 		}
4535 	}
4536 	FREE_LOCK(&lk);
4537 	bawrite(bp);
4538 	ACQUIRE_LOCK(&lk);
4539 	return(0);
4540 }
4541 
4542 /*
4543  * Flush the dependencies associated with an inodedep.
4544  * Called with splbio blocked.
4545  */
4546 static int
4547 flush_inodedep_deps(struct fs *fs, ino_t ino)
4548 {
4549 	struct inodedep *inodedep;
4550 	struct allocdirect *adp;
4551 	int error, waitfor;
4552 	struct buf *bp;
4553 
4554 	/*
4555 	 * This work is done in two passes. The first pass grabs most
4556 	 * of the buffers and begins asynchronously writing them. The
4557 	 * only way to wait for these asynchronous writes is to sleep
4558 	 * on the filesystem vnode which may stay busy for a long time
4559 	 * if the filesystem is active. So, instead, we make a second
4560 	 * pass over the dependencies blocking on each write. In the
4561 	 * usual case we will be blocking against a write that we
4562 	 * initiated, so when it is done the dependency will have been
4563 	 * resolved. Thus the second pass is expected to end quickly.
4564 	 * We give a brief window at the top of the loop to allow
4565 	 * any pending I/O to complete.
4566 	 */
4567 	for (waitfor = MNT_NOWAIT; ; ) {
4568 		FREE_LOCK(&lk);
4569 		ACQUIRE_LOCK(&lk);
4570 		if (inodedep_lookup(fs, ino, 0, &inodedep) == 0)
4571 			return (0);
4572 		TAILQ_FOREACH(adp, &inodedep->id_inoupdt, ad_next) {
4573 			if (adp->ad_state & DEPCOMPLETE)
4574 				continue;
4575 			bp = adp->ad_buf;
4576 			if (getdirtybuf(&bp, waitfor) == 0) {
4577 				if (waitfor == MNT_NOWAIT)
4578 					continue;
4579 				break;
4580 			}
4581 			FREE_LOCK(&lk);
4582 			if (waitfor == MNT_NOWAIT) {
4583 				bawrite(bp);
4584 			} else if ((error = bwrite(bp)) != 0) {
4585 				ACQUIRE_LOCK(&lk);
4586 				return (error);
4587 			}
4588 			ACQUIRE_LOCK(&lk);
4589 			break;
4590 		}
4591 		if (adp != NULL)
4592 			continue;
4593 		TAILQ_FOREACH(adp, &inodedep->id_newinoupdt, ad_next) {
4594 			if (adp->ad_state & DEPCOMPLETE)
4595 				continue;
4596 			bp = adp->ad_buf;
4597 			if (getdirtybuf(&bp, waitfor) == 0) {
4598 				if (waitfor == MNT_NOWAIT)
4599 					continue;
4600 				break;
4601 			}
4602 			FREE_LOCK(&lk);
4603 			if (waitfor == MNT_NOWAIT) {
4604 				bawrite(bp);
4605 			} else if ((error = bwrite(bp)) != 0) {
4606 				ACQUIRE_LOCK(&lk);
4607 				return (error);
4608 			}
4609 			ACQUIRE_LOCK(&lk);
4610 			break;
4611 		}
4612 		if (adp != NULL)
4613 			continue;
4614 		/*
4615 		 * If pass2, we are done, otherwise do pass 2.
4616 		 */
4617 		if (waitfor == MNT_WAIT)
4618 			break;
4619 		waitfor = MNT_WAIT;
4620 	}
4621 	/*
4622 	 * Try freeing inodedep in case all dependencies have been removed.
4623 	 */
4624 	if (inodedep_lookup(fs, ino, 0, &inodedep) != 0)
4625 		(void) free_inodedep(inodedep);
4626 	return (0);
4627 }
4628 
4629 /*
4630  * Eliminate a pagedep dependency by flushing out all its diradd dependencies.
4631  * Called with splbio blocked.
4632  */
4633 static int
4634 flush_pagedep_deps(struct vnode *pvp, struct mount *mp,
4635 		   struct diraddhd *diraddhdp)
4636 {
4637 	struct inodedep *inodedep;
4638 	struct ufsmount *ump;
4639 	struct diradd *dap;
4640 	struct vnode *vp;
4641 	int gotit, error = 0;
4642 	struct buf *bp;
4643 	ino_t inum;
4644 
4645 	ump = VFSTOUFS(mp);
4646 	while ((dap = LIST_FIRST(diraddhdp)) != NULL) {
4647 		/*
4648 		 * Flush ourselves if this directory entry
4649 		 * has a MKDIR_PARENT dependency.
4650 		 */
4651 		if (dap->da_state & MKDIR_PARENT) {
4652 			FREE_LOCK(&lk);
4653 			if ((error = ffs_update(pvp, 1)) != 0)
4654 				break;
4655 			ACQUIRE_LOCK(&lk);
4656 			/*
4657 			 * If that cleared dependencies, go on to next.
4658 			 */
4659 			if (dap != LIST_FIRST(diraddhdp))
4660 				continue;
4661 			if (dap->da_state & MKDIR_PARENT) {
4662 				FREE_LOCK(&lk);
4663 				panic("flush_pagedep_deps: MKDIR_PARENT");
4664 			}
4665 		}
4666 		/*
4667 		 * A newly allocated directory must have its "." and
4668 		 * ".." entries written out before its name can be
4669 		 * committed in its parent. We do not want or need
4670 		 * the full semantics of a synchronous VOP_FSYNC as
4671 		 * that may end up here again, once for each directory
4672 		 * level in the filesystem. Instead, we push the blocks
4673 		 * and wait for them to clear. We have to fsync twice
4674 		 * because the first call may choose to defer blocks
4675 		 * that still have dependencies, but deferral will
4676 		 * happen at most once.
4677 		 */
4678 		inum = dap->da_newinum;
4679 		if (dap->da_state & MKDIR_BODY) {
4680 			FREE_LOCK(&lk);
4681 			if ((error = VFS_VGET(mp, inum, &vp)) != 0)
4682 				break;
4683 			if ((error=VOP_FSYNC(vp, MNT_NOWAIT)) ||
4684 			    (error=VOP_FSYNC(vp, MNT_NOWAIT))) {
4685 				vput(vp);
4686 				break;
4687 			}
4688 			drain_output(vp, 0);
4689 			vput(vp);
4690 			ACQUIRE_LOCK(&lk);
4691 			/*
4692 			 * If that cleared dependencies, go on to next.
4693 			 */
4694 			if (dap != LIST_FIRST(diraddhdp))
4695 				continue;
4696 			if (dap->da_state & MKDIR_BODY) {
4697 				FREE_LOCK(&lk);
4698 				panic("flush_pagedep_deps: MKDIR_BODY");
4699 			}
4700 		}
4701 		/*
4702 		 * Flush the inode on which the directory entry depends.
4703 		 * Having accounted for MKDIR_PARENT and MKDIR_BODY above,
4704 		 * the only remaining dependency is that the updated inode
4705 		 * count must get pushed to disk. The inode has already
4706 		 * been pushed into its inode buffer (via VOP_UPDATE) at
4707 		 * the time of the reference count change. So we need only
4708 		 * locate that buffer, ensure that there will be no rollback
4709 		 * caused by a bitmap dependency, then write the inode buffer.
4710 		 */
4711 		if (inodedep_lookup(ump->um_fs, inum, 0, &inodedep) == 0) {
4712 			FREE_LOCK(&lk);
4713 			panic("flush_pagedep_deps: lost inode");
4714 		}
4715 		/*
4716 		 * If the inode still has bitmap dependencies,
4717 		 * push them to disk.
4718 		 */
4719 		if ((inodedep->id_state & DEPCOMPLETE) == 0) {
4720 			gotit = getdirtybuf(&inodedep->id_buf, MNT_WAIT);
4721 			FREE_LOCK(&lk);
4722 			if (gotit && (error = bwrite(inodedep->id_buf)) != 0)
4723 				break;
4724 			ACQUIRE_LOCK(&lk);
4725 			if (dap != LIST_FIRST(diraddhdp))
4726 				continue;
4727 		}
4728 		/*
4729 		 * If the inode is still sitting in a buffer waiting
4730 		 * to be written, push it to disk.
4731 		 */
4732 		FREE_LOCK(&lk);
4733 		if ((error = bread(ump->um_devvp,
4734 			fsbtodoff(ump->um_fs, ino_to_fsba(ump->um_fs, inum)),
4735 		    (int)ump->um_fs->fs_bsize, &bp)) != 0)
4736 			break;
4737 		if ((error = bwrite(bp)) != 0)
4738 			break;
4739 		ACQUIRE_LOCK(&lk);
4740 		/*
4741 		 * If we have failed to get rid of all the dependencies
4742 		 * then something is seriously wrong.
4743 		 */
4744 		if (dap == LIST_FIRST(diraddhdp)) {
4745 			FREE_LOCK(&lk);
4746 			panic("flush_pagedep_deps: flush failed");
4747 		}
4748 	}
4749 	if (error)
4750 		ACQUIRE_LOCK(&lk);
4751 	return (error);
4752 }
4753 
4754 /*
4755  * A large burst of file addition or deletion activity can drive the
4756  * memory load excessively high. First attempt to slow things down
4757  * using the techniques below. If that fails, this routine requests
4758  * the offending operations to fall back to running synchronously
4759  * until the memory load returns to a reasonable level.
4760  */
4761 int
4762 softdep_slowdown(struct vnode *vp)
4763 {
4764 	int max_softdeps_hard;
4765 
4766 	max_softdeps_hard = max_softdeps * 11 / 10;
4767 	if (num_dirrem < max_softdeps_hard / 2 &&
4768 	    num_inodedep < max_softdeps_hard)
4769 		return (0);
4770 	stat_sync_limit_hit += 1;
4771 	return (1);
4772 }
4773 
4774 /*
4775  * If memory utilization has gotten too high, deliberately slow things
4776  * down and speed up the I/O processing.
4777  */
4778 static int
4779 request_cleanup(int resource, int islocked)
4780 {
4781 	struct thread *td = curthread;		/* XXX */
4782 
4783 	/*
4784 	 * We never hold up the filesystem syncer process.
4785 	 */
4786 	if (td == filesys_syncer)
4787 		return (0);
4788 	/*
4789 	 * First check to see if the work list has gotten backlogged.
4790 	 * If it has, co-opt this process to help clean up two entries.
4791 	 * Because this process may hold inodes locked, we cannot
4792 	 * handle any remove requests that might block on a locked
4793 	 * inode as that could lead to deadlock.
4794 	 */
4795 	if (num_on_worklist > max_softdeps / 10) {
4796 		if (islocked)
4797 			FREE_LOCK(&lk);
4798 		process_worklist_item(NULL, LK_NOWAIT);
4799 		process_worklist_item(NULL, LK_NOWAIT);
4800 		stat_worklist_push += 2;
4801 		if (islocked)
4802 			ACQUIRE_LOCK(&lk);
4803 		return(1);
4804 	}
4805 
4806 	/*
4807 	 * If we are resource constrained on inode dependencies, try
4808 	 * flushing some dirty inodes. Otherwise, we are constrained
4809 	 * by file deletions, so try accelerating flushes of directories
4810 	 * with removal dependencies. We would like to do the cleanup
4811 	 * here, but we probably hold an inode locked at this point and
4812 	 * that might deadlock against one that we try to clean. So,
4813 	 * the best that we can do is request the syncer daemon to do
4814 	 * the cleanup for us.
4815 	 */
4816 	switch (resource) {
4817 
4818 	case FLUSH_INODES:
4819 		stat_ino_limit_push += 1;
4820 		req_clear_inodedeps += 1;
4821 		stat_countp = &stat_ino_limit_hit;
4822 		break;
4823 
4824 	case FLUSH_REMOVE:
4825 		stat_blk_limit_push += 1;
4826 		req_clear_remove += 1;
4827 		stat_countp = &stat_blk_limit_hit;
4828 		break;
4829 
4830 	default:
4831 		if (islocked)
4832 			FREE_LOCK(&lk);
4833 		panic("request_cleanup: unknown type");
4834 	}
4835 	/*
4836 	 * Hopefully the syncer daemon will catch up and awaken us.
4837 	 * We wait at most tickdelay before proceeding in any case.
4838 	 */
4839 	if (islocked == 0)
4840 		ACQUIRE_LOCK(&lk);
4841 	proc_waiting += 1;
4842 	if (!callout_active(&handle))
4843 		callout_reset(&handle, tickdelay > 2 ? tickdelay : 2,
4844 			      pause_timer, NULL);
4845 	interlocked_sleep(&lk, SLEEP, (caddr_t)&proc_waiting, 0,
4846 	    "softupdate", 0);
4847 	proc_waiting -= 1;
4848 	if (islocked == 0)
4849 		FREE_LOCK(&lk);
4850 	return (1);
4851 }
4852 
4853 /*
4854  * Awaken processes pausing in request_cleanup and clear proc_waiting
4855  * to indicate that there is no longer a timer running.
4856  */
4857 void
4858 pause_timer(void *arg)
4859 {
4860 	*stat_countp += 1;
4861 	wakeup_one(&proc_waiting);
4862 	if (proc_waiting > 0)
4863 		callout_reset(&handle, tickdelay > 2 ? tickdelay : 2,
4864 			      pause_timer, NULL);
4865 	else
4866 		callout_deactivate(&handle);
4867 }
4868 
4869 /*
4870  * Flush out a directory with at least one removal dependency in an effort to
4871  * reduce the number of dirrem, freefile, and freeblks dependency structures.
4872  */
4873 static void
4874 clear_remove(struct thread *td)
4875 {
4876 	struct pagedep_hashhead *pagedephd;
4877 	struct pagedep *pagedep;
4878 	static int next = 0;
4879 	struct mount *mp;
4880 	struct vnode *vp;
4881 	int error, cnt;
4882 	ino_t ino;
4883 
4884 	ACQUIRE_LOCK(&lk);
4885 	for (cnt = 0; cnt < pagedep_hash; cnt++) {
4886 		pagedephd = &pagedep_hashtbl[next++];
4887 		if (next >= pagedep_hash)
4888 			next = 0;
4889 		LIST_FOREACH(pagedep, pagedephd, pd_hash) {
4890 			if (LIST_FIRST(&pagedep->pd_dirremhd) == NULL)
4891 				continue;
4892 			mp = pagedep->pd_mnt;
4893 			ino = pagedep->pd_ino;
4894 			FREE_LOCK(&lk);
4895 			if ((error = VFS_VGET(mp, ino, &vp)) != 0) {
4896 				softdep_error("clear_remove: vget", error);
4897 				return;
4898 			}
4899 			if ((error = VOP_FSYNC(vp, MNT_NOWAIT)))
4900 				softdep_error("clear_remove: fsync", error);
4901 			drain_output(vp, 0);
4902 			vput(vp);
4903 			return;
4904 		}
4905 	}
4906 	FREE_LOCK(&lk);
4907 }
4908 
4909 /*
4910  * Clear out a block of dirty inodes in an effort to reduce
4911  * the number of inodedep dependency structures.
4912  */
4913 struct clear_inodedeps_info {
4914 	struct fs *fs;
4915 	struct mount *mp;
4916 };
4917 
4918 static int
4919 clear_inodedeps_mountlist_callback(struct mount *mp, void *data)
4920 {
4921 	struct clear_inodedeps_info *info = data;
4922 
4923 	if ((mp->mnt_flag & MNT_SOFTDEP) && info->fs == VFSTOUFS(mp)->um_fs) {
4924 		info->mp = mp;
4925 		return(-1);
4926 	}
4927 	return(0);
4928 }
4929 
4930 static void
4931 clear_inodedeps(struct thread *td)
4932 {
4933 	struct clear_inodedeps_info info;
4934 	struct inodedep_hashhead *inodedephd;
4935 	struct inodedep *inodedep;
4936 	static int next = 0;
4937 	struct vnode *vp;
4938 	struct fs *fs;
4939 	int error, cnt;
4940 	ino_t firstino, lastino, ino;
4941 
4942 	ACQUIRE_LOCK(&lk);
4943 	/*
4944 	 * Pick a random inode dependency to be cleared.
4945 	 * We will then gather up all the inodes in its block
4946 	 * that have dependencies and flush them out.
4947 	 */
4948 	for (cnt = 0; cnt < inodedep_hash; cnt++) {
4949 		inodedephd = &inodedep_hashtbl[next++];
4950 		if (next >= inodedep_hash)
4951 			next = 0;
4952 		if ((inodedep = LIST_FIRST(inodedephd)) != NULL)
4953 			break;
4954 	}
4955 	if (inodedep == NULL) {
4956 		FREE_LOCK(&lk);
4957 		return;
4958 	}
4959 	/*
4960 	 * Ugly code to find mount point given pointer to superblock.
4961 	 */
4962 	fs = inodedep->id_fs;
4963 	info.mp = NULL;
4964 	info.fs = fs;
4965 	mountlist_scan(clear_inodedeps_mountlist_callback,
4966 			&info, MNTSCAN_FORWARD|MNTSCAN_NOBUSY);
4967 	/*
4968 	 * Find the last inode in the block with dependencies.
4969 	 */
4970 	firstino = inodedep->id_ino & ~(INOPB(fs) - 1);
4971 	for (lastino = firstino + INOPB(fs) - 1; lastino > firstino; lastino--)
4972 		if (inodedep_lookup(fs, lastino, 0, &inodedep) != 0)
4973 			break;
4974 	/*
4975 	 * Asynchronously push all but the last inode with dependencies.
4976 	 * Synchronously push the last inode with dependencies to ensure
4977 	 * that the inode block gets written to free up the inodedeps.
4978 	 */
4979 	for (ino = firstino; ino <= lastino; ino++) {
4980 		if (inodedep_lookup(fs, ino, 0, &inodedep) == 0)
4981 			continue;
4982 		FREE_LOCK(&lk);
4983 		if ((error = VFS_VGET(info.mp, ino, &vp)) != 0) {
4984 			softdep_error("clear_inodedeps: vget", error);
4985 			return;
4986 		}
4987 		if (ino == lastino) {
4988 			if ((error = VOP_FSYNC(vp, MNT_WAIT)))
4989 				softdep_error("clear_inodedeps: fsync1", error);
4990 		} else {
4991 			if ((error = VOP_FSYNC(vp, MNT_NOWAIT)))
4992 				softdep_error("clear_inodedeps: fsync2", error);
4993 			drain_output(vp, 0);
4994 		}
4995 		vput(vp);
4996 		ACQUIRE_LOCK(&lk);
4997 	}
4998 	FREE_LOCK(&lk);
4999 }
5000 
5001 /*
5002  * Function to determine if the buffer has outstanding dependencies
5003  * that will cause a roll-back if the buffer is written. If wantcount
5004  * is set, return number of dependencies, otherwise just yes or no.
5005  */
5006 static int
5007 softdep_count_dependencies(struct buf *bp, int wantcount)
5008 {
5009 	struct worklist *wk;
5010 	struct inodedep *inodedep;
5011 	struct indirdep *indirdep;
5012 	struct allocindir *aip;
5013 	struct pagedep *pagedep;
5014 	struct diradd *dap;
5015 	int i, retval;
5016 
5017 	retval = 0;
5018 	ACQUIRE_LOCK(&lk);
5019 	LIST_FOREACH(wk, &bp->b_dep, wk_list) {
5020 		switch (wk->wk_type) {
5021 
5022 		case D_INODEDEP:
5023 			inodedep = WK_INODEDEP(wk);
5024 			if ((inodedep->id_state & DEPCOMPLETE) == 0) {
5025 				/* bitmap allocation dependency */
5026 				retval += 1;
5027 				if (!wantcount)
5028 					goto out;
5029 			}
5030 			if (TAILQ_FIRST(&inodedep->id_inoupdt)) {
5031 				/* direct block pointer dependency */
5032 				retval += 1;
5033 				if (!wantcount)
5034 					goto out;
5035 			}
5036 			continue;
5037 
5038 		case D_INDIRDEP:
5039 			indirdep = WK_INDIRDEP(wk);
5040 
5041 			LIST_FOREACH(aip, &indirdep->ir_deplisthd, ai_next) {
5042 				/* indirect block pointer dependency */
5043 				retval += 1;
5044 				if (!wantcount)
5045 					goto out;
5046 			}
5047 			continue;
5048 
5049 		case D_PAGEDEP:
5050 			pagedep = WK_PAGEDEP(wk);
5051 			for (i = 0; i < DAHASHSZ; i++) {
5052 
5053 				LIST_FOREACH(dap, &pagedep->pd_diraddhd[i], da_pdlist) {
5054 					/* directory entry dependency */
5055 					retval += 1;
5056 					if (!wantcount)
5057 						goto out;
5058 				}
5059 			}
5060 			continue;
5061 
5062 		case D_BMSAFEMAP:
5063 		case D_ALLOCDIRECT:
5064 		case D_ALLOCINDIR:
5065 		case D_MKDIR:
5066 			/* never a dependency on these blocks */
5067 			continue;
5068 
5069 		default:
5070 			FREE_LOCK(&lk);
5071 			panic("softdep_check_for_rollback: Unexpected type %s",
5072 			    TYPENAME(wk->wk_type));
5073 			/* NOTREACHED */
5074 		}
5075 	}
5076 out:
5077 	FREE_LOCK(&lk);
5078 	return retval;
5079 }
5080 
5081 /*
5082  * Acquire exclusive access to a buffer.
5083  * Must be called with splbio blocked.
5084  * Return 1 if buffer was acquired.
5085  */
5086 static int
5087 getdirtybuf(struct buf **bpp, int waitfor)
5088 {
5089 	struct buf *bp;
5090 	int error;
5091 
5092 	for (;;) {
5093 		if ((bp = *bpp) == NULL)
5094 			return (0);
5095 		if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT) == 0)
5096 			break;
5097 		if (waitfor != MNT_WAIT)
5098 			return (0);
5099 		error = interlocked_sleep(&lk, LOCKBUF, bp,
5100 		    LK_EXCLUSIVE | LK_SLEEPFAIL, 0, 0);
5101 		if (error != ENOLCK) {
5102 			FREE_LOCK(&lk);
5103 			panic("getdirtybuf: inconsistent lock");
5104 		}
5105 	}
5106 	if ((bp->b_flags & B_DELWRI) == 0) {
5107 		BUF_UNLOCK(bp);
5108 		return (0);
5109 	}
5110 	bremfree(bp);
5111 	return (1);
5112 }
5113 
5114 /*
5115  * Wait for pending output on a vnode to complete.
5116  * Must be called with vnode locked.
5117  */
5118 static void
5119 drain_output(struct vnode *vp, int islocked)
5120 {
5121 
5122 	if (!islocked)
5123 		ACQUIRE_LOCK(&lk);
5124 	while (vp->v_track_write.bk_active) {
5125 		vp->v_track_write.bk_waitflag = 1;
5126 		interlocked_sleep(&lk, SLEEP, &vp->v_track_write,
5127 				  0, "drainvp", 0);
5128 	}
5129 	if (!islocked)
5130 		FREE_LOCK(&lk);
5131 }
5132 
5133 /*
5134  * Called whenever a buffer that is being invalidated or reallocated
5135  * contains dependencies. This should only happen if an I/O error has
5136  * occurred. The routine is called with the buffer locked.
5137  */
5138 static void
5139 softdep_deallocate_dependencies(struct buf *bp)
5140 {
5141 	if ((bp->b_flags & B_ERROR) == 0)
5142 		panic("softdep_deallocate_dependencies: dangling deps");
5143 	softdep_error(bp->b_vp->v_mount->mnt_stat.f_mntfromname, bp->b_error);
5144 	panic("softdep_deallocate_dependencies: unrecovered I/O error");
5145 }
5146 
5147 /*
5148  * Function to handle asynchronous write errors in the filesystem.
5149  */
5150 void
5151 softdep_error(char *func, int error)
5152 {
5153 
5154 	/* XXX should do something better! */
5155 	kprintf("%s: got error %d while accessing filesystem\n", func, error);
5156 }
5157