xref: /dragonfly/sys/vfs/ufs/ffs_softdep.c (revision b7367ef6)
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 1.52 2007/08/13 17:31:56 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 
208 static struct bio_ops softdep_bioops = {
209 	softdep_disk_io_initiation,		/* io_start */
210 	softdep_disk_write_complete,		/* io_complete */
211 	softdep_deallocate_dependencies,	/* io_deallocate */
212 	softdep_fsync,				/* io_fsync */
213 	softdep_process_worklist,		/* io_sync */
214 	softdep_move_dependencies,		/* io_movedeps */
215 	softdep_count_dependencies,		/* io_countdeps */
216 };
217 
218 /*
219  * Locking primitives.
220  *
221  * For a uniprocessor, all we need to do is protect against disk
222  * interrupts. For a multiprocessor, this lock would have to be
223  * a mutex. A single mutex is used throughout this file, though
224  * finer grain locking could be used if contention warranted it.
225  *
226  * For a multiprocessor, the sleep call would accept a lock and
227  * release it after the sleep processing was complete. In a uniprocessor
228  * implementation there is no such interlock, so we simple mark
229  * the places where it needs to be done with the `interlocked' form
230  * of the lock calls. Since the uniprocessor sleep already interlocks
231  * the spl, there is nothing that really needs to be done.
232  */
233 #ifndef /* NOT */ DEBUG
234 static struct lockit {
235 } lk = { 0 };
236 #define ACQUIRE_LOCK(lk)		crit_enter_id("softupdates");
237 #define FREE_LOCK(lk)			crit_exit_id("softupdates");
238 
239 #else /* DEBUG */
240 #define NOHOLDER	((struct thread *)-1)
241 #define SPECIAL_FLAG	((struct thread *)-2)
242 static struct lockit {
243 	int	lkt_spl;
244 	struct thread *lkt_held;
245 } lk = { 0, NOHOLDER };
246 static int lockcnt;
247 
248 static	void acquire_lock(struct lockit *);
249 static	void free_lock(struct lockit *);
250 void	softdep_panic(char *);
251 
252 #define ACQUIRE_LOCK(lk)		acquire_lock(lk)
253 #define FREE_LOCK(lk)			free_lock(lk)
254 
255 static void
256 acquire_lock(struct lockit *lk)
257 {
258 	thread_t holder;
259 
260 	if (lk->lkt_held != NOHOLDER) {
261 		holder = lk->lkt_held;
262 		FREE_LOCK(lk);
263 		if (holder == curthread)
264 			panic("softdep_lock: locking against myself");
265 		else
266 			panic("softdep_lock: lock held by %p", holder);
267 	}
268 	crit_enter_id("softupdates");
269 	lk->lkt_held = curthread;
270 	lockcnt++;
271 }
272 
273 static void
274 free_lock(struct lockit *lk)
275 {
276 
277 	if (lk->lkt_held == NOHOLDER)
278 		panic("softdep_unlock: lock not held");
279 	lk->lkt_held = NOHOLDER;
280 	crit_exit_id("softupdates");
281 }
282 
283 /*
284  * Function to release soft updates lock and panic.
285  */
286 void
287 softdep_panic(char *msg)
288 {
289 
290 	if (lk.lkt_held != NOHOLDER)
291 		FREE_LOCK(&lk);
292 	panic(msg);
293 }
294 #endif /* DEBUG */
295 
296 static	int interlocked_sleep(struct lockit *, int, void *, int,
297 	    const char *, int);
298 
299 /*
300  * When going to sleep, we must save our SPL so that it does
301  * not get lost if some other process uses the lock while we
302  * are sleeping. We restore it after we have slept. This routine
303  * wraps the interlocking with functions that sleep. The list
304  * below enumerates the available set of operations.
305  */
306 #define	UNKNOWN		0
307 #define	SLEEP		1
308 #define	LOCKBUF		2
309 
310 static int
311 interlocked_sleep(struct lockit *lk, int op, void *ident, int flags,
312 		  const char *wmesg, int timo)
313 {
314 	thread_t holder;
315 	int s, retval;
316 
317 	s = lk->lkt_spl;
318 #	ifdef DEBUG
319 	if (lk->lkt_held == NOHOLDER)
320 		panic("interlocked_sleep: lock not held");
321 	lk->lkt_held = NOHOLDER;
322 #	endif /* DEBUG */
323 	switch (op) {
324 	case SLEEP:
325 		retval = tsleep(ident, flags, wmesg, timo);
326 		break;
327 	case LOCKBUF:
328 		retval = BUF_LOCK((struct buf *)ident, flags);
329 		break;
330 	default:
331 		panic("interlocked_sleep: unknown operation");
332 	}
333 #	ifdef DEBUG
334 	if (lk->lkt_held != NOHOLDER) {
335 		holder = lk->lkt_held;
336 		FREE_LOCK(lk);
337 		if (holder == curthread)
338 			panic("interlocked_sleep: locking against self");
339 		else
340 			panic("interlocked_sleep: lock held by %p", holder);
341 	}
342 	lk->lkt_held = curthread;
343 	lockcnt++;
344 #	endif /* DEBUG */
345 	lk->lkt_spl = s;
346 	return (retval);
347 }
348 
349 /*
350  * Place holder for real semaphores.
351  */
352 struct sema {
353 	int	value;
354 	thread_t holder;
355 	char	*name;
356 	int	prio;
357 	int	timo;
358 };
359 static	void sema_init(struct sema *, char *, int, int);
360 static	int sema_get(struct sema *, struct lockit *);
361 static	void sema_release(struct sema *);
362 
363 static void
364 sema_init(struct sema *semap, char *name, int prio, int timo)
365 {
366 
367 	semap->holder = NOHOLDER;
368 	semap->value = 0;
369 	semap->name = name;
370 	semap->prio = prio;
371 	semap->timo = timo;
372 }
373 
374 static int
375 sema_get(struct sema *semap, struct lockit *interlock)
376 {
377 
378 	if (semap->value++ > 0) {
379 		if (interlock != NULL) {
380 			interlocked_sleep(interlock, SLEEP, (caddr_t)semap,
381 			    semap->prio, semap->name, semap->timo);
382 			FREE_LOCK(interlock);
383 		} else {
384 			tsleep((caddr_t)semap, semap->prio, semap->name,
385 			    semap->timo);
386 		}
387 		return (0);
388 	}
389 	semap->holder = curthread;
390 	if (interlock != NULL)
391 		FREE_LOCK(interlock);
392 	return (1);
393 }
394 
395 static void
396 sema_release(struct sema *semap)
397 {
398 
399 	if (semap->value <= 0 || semap->holder != curthread) {
400 		if (lk.lkt_held != NOHOLDER)
401 			FREE_LOCK(&lk);
402 		panic("sema_release: not held");
403 	}
404 	if (--semap->value > 0) {
405 		semap->value = 0;
406 		wakeup(semap);
407 	}
408 	semap->holder = NOHOLDER;
409 }
410 
411 /*
412  * Worklist queue management.
413  * These routines require that the lock be held.
414  */
415 #ifndef /* NOT */ DEBUG
416 #define WORKLIST_INSERT(head, item) do {	\
417 	(item)->wk_state |= ONWORKLIST;		\
418 	LIST_INSERT_HEAD(head, item, wk_list);	\
419 } while (0)
420 #define WORKLIST_REMOVE(item) do {		\
421 	(item)->wk_state &= ~ONWORKLIST;	\
422 	LIST_REMOVE(item, wk_list);		\
423 } while (0)
424 #define WORKITEM_FREE(item, type) FREE(item, DtoM(type))
425 
426 #else /* DEBUG */
427 static	void worklist_insert(struct workhead *, struct worklist *);
428 static	void worklist_remove(struct worklist *);
429 static	void workitem_free(struct worklist *, int);
430 
431 #define WORKLIST_INSERT(head, item) worklist_insert(head, item)
432 #define WORKLIST_REMOVE(item) worklist_remove(item)
433 #define WORKITEM_FREE(item, type) workitem_free((struct worklist *)item, type)
434 
435 static void
436 worklist_insert(struct workhead *head, struct worklist *item)
437 {
438 
439 	if (lk.lkt_held == NOHOLDER)
440 		panic("worklist_insert: lock not held");
441 	if (item->wk_state & ONWORKLIST) {
442 		FREE_LOCK(&lk);
443 		panic("worklist_insert: already on list");
444 	}
445 	item->wk_state |= ONWORKLIST;
446 	LIST_INSERT_HEAD(head, item, wk_list);
447 }
448 
449 static void
450 worklist_remove(struct worklist *item)
451 {
452 
453 	if (lk.lkt_held == NOHOLDER)
454 		panic("worklist_remove: lock not held");
455 	if ((item->wk_state & ONWORKLIST) == 0) {
456 		FREE_LOCK(&lk);
457 		panic("worklist_remove: not on list");
458 	}
459 	item->wk_state &= ~ONWORKLIST;
460 	LIST_REMOVE(item, wk_list);
461 }
462 
463 static void
464 workitem_free(struct worklist *item, int type)
465 {
466 
467 	if (item->wk_state & ONWORKLIST) {
468 		if (lk.lkt_held != NOHOLDER)
469 			FREE_LOCK(&lk);
470 		panic("workitem_free: still on list");
471 	}
472 	if (item->wk_type != type) {
473 		if (lk.lkt_held != NOHOLDER)
474 			FREE_LOCK(&lk);
475 		panic("workitem_free: type mismatch");
476 	}
477 	FREE(item, DtoM(type));
478 }
479 #endif /* DEBUG */
480 
481 /*
482  * Workitem queue management
483  */
484 static struct workhead softdep_workitem_pending;
485 static int num_on_worklist;	/* number of worklist items to be processed */
486 static int softdep_worklist_busy; /* 1 => trying to do unmount */
487 static int softdep_worklist_req; /* serialized waiters */
488 static int max_softdeps;	/* maximum number of structs before slowdown */
489 static int tickdelay = 2;	/* number of ticks to pause during slowdown */
490 static int *stat_countp;	/* statistic to count in proc_waiting timeout */
491 static int proc_waiting;	/* tracks whether we have a timeout posted */
492 static struct callout handle; /* handle on posted proc_waiting timeout */
493 static struct thread *filesys_syncer; /* proc of filesystem syncer process */
494 static int req_clear_inodedeps;	/* syncer process flush some inodedeps */
495 #define FLUSH_INODES	1
496 static int req_clear_remove;	/* syncer process flush some freeblks */
497 #define FLUSH_REMOVE	2
498 /*
499  * runtime statistics
500  */
501 static int stat_worklist_push;	/* number of worklist cleanups */
502 static int stat_blk_limit_push;	/* number of times block limit neared */
503 static int stat_ino_limit_push;	/* number of times inode limit neared */
504 static int stat_blk_limit_hit;	/* number of times block slowdown imposed */
505 static int stat_ino_limit_hit;	/* number of times inode slowdown imposed */
506 static int stat_sync_limit_hit;	/* number of synchronous slowdowns imposed */
507 static int stat_indir_blk_ptrs;	/* bufs redirtied as indir ptrs not written */
508 static int stat_inode_bitmap;	/* bufs redirtied as inode bitmap not written */
509 static int stat_direct_blk_ptrs;/* bufs redirtied as direct ptrs not written */
510 static int stat_dir_entry;	/* bufs redirtied as dir entry cannot write */
511 #ifdef DEBUG
512 #include <vm/vm.h>
513 #include <sys/sysctl.h>
514 SYSCTL_INT(_debug, OID_AUTO, max_softdeps, CTLFLAG_RW, &max_softdeps, 0, "");
515 SYSCTL_INT(_debug, OID_AUTO, tickdelay, CTLFLAG_RW, &tickdelay, 0, "");
516 SYSCTL_INT(_debug, OID_AUTO, worklist_push, CTLFLAG_RW, &stat_worklist_push, 0,"");
517 SYSCTL_INT(_debug, OID_AUTO, blk_limit_push, CTLFLAG_RW, &stat_blk_limit_push, 0,"");
518 SYSCTL_INT(_debug, OID_AUTO, ino_limit_push, CTLFLAG_RW, &stat_ino_limit_push, 0,"");
519 SYSCTL_INT(_debug, OID_AUTO, blk_limit_hit, CTLFLAG_RW, &stat_blk_limit_hit, 0, "");
520 SYSCTL_INT(_debug, OID_AUTO, ino_limit_hit, CTLFLAG_RW, &stat_ino_limit_hit, 0, "");
521 SYSCTL_INT(_debug, OID_AUTO, sync_limit_hit, CTLFLAG_RW, &stat_sync_limit_hit, 0, "");
522 SYSCTL_INT(_debug, OID_AUTO, indir_blk_ptrs, CTLFLAG_RW, &stat_indir_blk_ptrs, 0, "");
523 SYSCTL_INT(_debug, OID_AUTO, inode_bitmap, CTLFLAG_RW, &stat_inode_bitmap, 0, "");
524 SYSCTL_INT(_debug, OID_AUTO, direct_blk_ptrs, CTLFLAG_RW, &stat_direct_blk_ptrs, 0, "");
525 SYSCTL_INT(_debug, OID_AUTO, dir_entry, CTLFLAG_RW, &stat_dir_entry, 0, "");
526 #endif /* DEBUG */
527 
528 /*
529  * Add an item to the end of the work queue.
530  * This routine requires that the lock be held.
531  * This is the only routine that adds items to the list.
532  * The following routine is the only one that removes items
533  * and does so in order from first to last.
534  */
535 static void
536 add_to_worklist(struct worklist *wk)
537 {
538 	static struct worklist *worklist_tail;
539 
540 	if (wk->wk_state & ONWORKLIST) {
541 		if (lk.lkt_held != NOHOLDER)
542 			FREE_LOCK(&lk);
543 		panic("add_to_worklist: already on list");
544 	}
545 	wk->wk_state |= ONWORKLIST;
546 	if (LIST_FIRST(&softdep_workitem_pending) == NULL)
547 		LIST_INSERT_HEAD(&softdep_workitem_pending, wk, wk_list);
548 	else
549 		LIST_INSERT_AFTER(worklist_tail, wk, wk_list);
550 	worklist_tail = wk;
551 	num_on_worklist += 1;
552 }
553 
554 /*
555  * Process that runs once per second to handle items in the background queue.
556  *
557  * Note that we ensure that everything is done in the order in which they
558  * appear in the queue. The code below depends on this property to ensure
559  * that blocks of a file are freed before the inode itself is freed. This
560  * ordering ensures that no new <vfsid, inum, lbn> triples will be generated
561  * until all the old ones have been purged from the dependency lists.
562  */
563 static int
564 softdep_process_worklist(struct mount *matchmnt)
565 {
566 	thread_t td = curthread;
567 	int matchcnt, loopcount;
568 	long starttime;
569 
570 	/*
571 	 * Record the process identifier of our caller so that we can give
572 	 * this process preferential treatment in request_cleanup below.
573 	 */
574 	filesys_syncer = td;
575 	matchcnt = 0;
576 
577 	/*
578 	 * There is no danger of having multiple processes run this
579 	 * code, but we have to single-thread it when softdep_flushfiles()
580 	 * is in operation to get an accurate count of the number of items
581 	 * related to its mount point that are in the list.
582 	 */
583 	if (matchmnt == NULL) {
584 		if (softdep_worklist_busy < 0)
585 			return(-1);
586 		softdep_worklist_busy += 1;
587 	}
588 
589 	/*
590 	 * If requested, try removing inode or removal dependencies.
591 	 */
592 	if (req_clear_inodedeps) {
593 		clear_inodedeps(td);
594 		req_clear_inodedeps -= 1;
595 		wakeup_one(&proc_waiting);
596 	}
597 	if (req_clear_remove) {
598 		clear_remove(td);
599 		req_clear_remove -= 1;
600 		wakeup_one(&proc_waiting);
601 	}
602 	loopcount = 1;
603 	starttime = time_second;
604 	while (num_on_worklist > 0) {
605 		matchcnt += process_worklist_item(matchmnt, 0);
606 
607 		/*
608 		 * If a umount operation wants to run the worklist
609 		 * accurately, abort.
610 		 */
611 		if (softdep_worklist_req && matchmnt == NULL) {
612 			matchcnt = -1;
613 			break;
614 		}
615 
616 		/*
617 		 * If requested, try removing inode or removal dependencies.
618 		 */
619 		if (req_clear_inodedeps) {
620 			clear_inodedeps(td);
621 			req_clear_inodedeps -= 1;
622 			wakeup_one(&proc_waiting);
623 		}
624 		if (req_clear_remove) {
625 			clear_remove(td);
626 			req_clear_remove -= 1;
627 			wakeup_one(&proc_waiting);
628 		}
629 		/*
630 		 * We do not generally want to stop for buffer space, but if
631 		 * we are really being a buffer hog, we will stop and wait.
632 		 */
633 		if (loopcount++ % 128 == 0)
634 			bwillwrite();
635 		/*
636 		 * Never allow processing to run for more than one
637 		 * second. Otherwise the other syncer tasks may get
638 		 * excessively backlogged.
639 		 */
640 		if (starttime != time_second && matchmnt == NULL) {
641 			matchcnt = -1;
642 			break;
643 		}
644 	}
645 	if (matchmnt == NULL) {
646 		--softdep_worklist_busy;
647 		if (softdep_worklist_req && softdep_worklist_busy == 0)
648 			wakeup(&softdep_worklist_req);
649 	}
650 	return (matchcnt);
651 }
652 
653 /*
654  * Process one item on the worklist.
655  */
656 static int
657 process_worklist_item(struct mount *matchmnt, int flags)
658 {
659 	struct worklist *wk;
660 	struct dirrem *dirrem;
661 	struct fs *matchfs;
662 	struct vnode *vp;
663 	int matchcnt = 0;
664 
665 	matchfs = NULL;
666 	if (matchmnt != NULL)
667 		matchfs = VFSTOUFS(matchmnt)->um_fs;
668 	ACQUIRE_LOCK(&lk);
669 	/*
670 	 * Normally we just process each item on the worklist in order.
671 	 * However, if we are in a situation where we cannot lock any
672 	 * inodes, we have to skip over any dirrem requests whose
673 	 * vnodes are resident and locked.
674 	 */
675 	LIST_FOREACH(wk, &softdep_workitem_pending, wk_list) {
676 		if ((flags & LK_NOWAIT) == 0 || wk->wk_type != D_DIRREM)
677 			break;
678 		dirrem = WK_DIRREM(wk);
679 		vp = ufs_ihashlookup(VFSTOUFS(dirrem->dm_mnt)->um_dev,
680 		    dirrem->dm_oldinum);
681 		if (vp == NULL || !vn_islocked(vp))
682 			break;
683 	}
684 	if (wk == 0) {
685 		FREE_LOCK(&lk);
686 		return (0);
687 	}
688 	WORKLIST_REMOVE(wk);
689 	num_on_worklist -= 1;
690 	FREE_LOCK(&lk);
691 	switch (wk->wk_type) {
692 
693 	case D_DIRREM:
694 		/* removal of a directory entry */
695 		if (WK_DIRREM(wk)->dm_mnt == matchmnt)
696 			matchcnt += 1;
697 		handle_workitem_remove(WK_DIRREM(wk));
698 		break;
699 
700 	case D_FREEBLKS:
701 		/* releasing blocks and/or fragments from a file */
702 		if (WK_FREEBLKS(wk)->fb_fs == matchfs)
703 			matchcnt += 1;
704 		handle_workitem_freeblocks(WK_FREEBLKS(wk));
705 		break;
706 
707 	case D_FREEFRAG:
708 		/* releasing a fragment when replaced as a file grows */
709 		if (WK_FREEFRAG(wk)->ff_fs == matchfs)
710 			matchcnt += 1;
711 		handle_workitem_freefrag(WK_FREEFRAG(wk));
712 		break;
713 
714 	case D_FREEFILE:
715 		/* releasing an inode when its link count drops to 0 */
716 		if (WK_FREEFILE(wk)->fx_fs == matchfs)
717 			matchcnt += 1;
718 		handle_workitem_freefile(WK_FREEFILE(wk));
719 		break;
720 
721 	default:
722 		panic("%s_process_worklist: Unknown type %s",
723 		    "softdep", TYPENAME(wk->wk_type));
724 		/* NOTREACHED */
725 	}
726 	return (matchcnt);
727 }
728 
729 /*
730  * Move dependencies from one buffer to another.
731  */
732 static void
733 softdep_move_dependencies(struct buf *oldbp, struct buf *newbp)
734 {
735 	struct worklist *wk, *wktail;
736 
737 	if (LIST_FIRST(&newbp->b_dep) != NULL)
738 		panic("softdep_move_dependencies: need merge code");
739 	wktail = 0;
740 	ACQUIRE_LOCK(&lk);
741 	while ((wk = LIST_FIRST(&oldbp->b_dep)) != NULL) {
742 		LIST_REMOVE(wk, wk_list);
743 		if (wktail == 0)
744 			LIST_INSERT_HEAD(&newbp->b_dep, wk, wk_list);
745 		else
746 			LIST_INSERT_AFTER(wktail, wk, wk_list);
747 		wktail = wk;
748 	}
749 	FREE_LOCK(&lk);
750 }
751 
752 /*
753  * Purge the work list of all items associated with a particular mount point.
754  */
755 int
756 softdep_flushfiles(struct mount *oldmnt, int flags)
757 {
758 	struct vnode *devvp;
759 	int error, loopcnt;
760 
761 	/*
762 	 * Await our turn to clear out the queue, then serialize access.
763 	 */
764 	while (softdep_worklist_busy != 0) {
765 		softdep_worklist_req += 1;
766 		tsleep(&softdep_worklist_req, 0, "softflush", 0);
767 		softdep_worklist_req -= 1;
768 	}
769 	softdep_worklist_busy = -1;
770 
771 	if ((error = ffs_flushfiles(oldmnt, flags)) != 0) {
772 		softdep_worklist_busy = 0;
773 		if (softdep_worklist_req)
774 			wakeup(&softdep_worklist_req);
775 		return (error);
776 	}
777 	/*
778 	 * Alternately flush the block device associated with the mount
779 	 * point and process any dependencies that the flushing
780 	 * creates. In theory, this loop can happen at most twice,
781 	 * but we give it a few extra just to be sure.
782 	 */
783 	devvp = VFSTOUFS(oldmnt)->um_devvp;
784 	for (loopcnt = 10; loopcnt > 0; ) {
785 		if (softdep_process_worklist(oldmnt) == 0) {
786 			loopcnt--;
787 			/*
788 			 * Do another flush in case any vnodes were brought in
789 			 * as part of the cleanup operations.
790 			 */
791 			if ((error = ffs_flushfiles(oldmnt, flags)) != 0)
792 				break;
793 			/*
794 			 * If we still found nothing to do, we are really done.
795 			 */
796 			if (softdep_process_worklist(oldmnt) == 0)
797 				break;
798 		}
799 		vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
800 		error = VOP_FSYNC(devvp, MNT_WAIT);
801 		vn_unlock(devvp);
802 		if (error)
803 			break;
804 	}
805 	softdep_worklist_busy = 0;
806 	if (softdep_worklist_req)
807 		wakeup(&softdep_worklist_req);
808 
809 	/*
810 	 * If we are unmounting then it is an error to fail. If we
811 	 * are simply trying to downgrade to read-only, then filesystem
812 	 * activity can keep us busy forever, so we just fail with EBUSY.
813 	 */
814 	if (loopcnt == 0) {
815 		if (oldmnt->mnt_kern_flag & MNTK_UNMOUNT)
816 			panic("softdep_flushfiles: looping");
817 		error = EBUSY;
818 	}
819 	return (error);
820 }
821 
822 /*
823  * Structure hashing.
824  *
825  * There are three types of structures that can be looked up:
826  *	1) pagedep structures identified by mount point, inode number,
827  *	   and logical block.
828  *	2) inodedep structures identified by mount point and inode number.
829  *	3) newblk structures identified by mount point and
830  *	   physical block number.
831  *
832  * The "pagedep" and "inodedep" dependency structures are hashed
833  * separately from the file blocks and inodes to which they correspond.
834  * This separation helps when the in-memory copy of an inode or
835  * file block must be replaced. It also obviates the need to access
836  * an inode or file page when simply updating (or de-allocating)
837  * dependency structures. Lookup of newblk structures is needed to
838  * find newly allocated blocks when trying to associate them with
839  * their allocdirect or allocindir structure.
840  *
841  * The lookup routines optionally create and hash a new instance when
842  * an existing entry is not found.
843  */
844 #define DEPALLOC	0x0001	/* allocate structure if lookup fails */
845 #define NODELAY		0x0002	/* cannot do background work */
846 
847 /*
848  * Structures and routines associated with pagedep caching.
849  */
850 LIST_HEAD(pagedep_hashhead, pagedep) *pagedep_hashtbl;
851 u_long	pagedep_hash;		/* size of hash table - 1 */
852 #define	PAGEDEP_HASH(mp, inum, lbn) \
853 	(&pagedep_hashtbl[((((register_t)(mp)) >> 13) + (inum) + (lbn)) & \
854 	    pagedep_hash])
855 static struct sema pagedep_in_progress;
856 
857 /*
858  * Helper routine for pagedep_lookup()
859  */
860 static __inline
861 struct pagedep *
862 pagedep_find(struct pagedep_hashhead *pagedephd, ino_t ino, ufs_lbn_t lbn,
863 	     struct mount *mp)
864 {
865 	struct pagedep *pagedep;
866 
867 	LIST_FOREACH(pagedep, pagedephd, pd_hash) {
868 		if (ino == pagedep->pd_ino &&
869 		    lbn == pagedep->pd_lbn &&
870 		    mp == pagedep->pd_mnt) {
871 			return (pagedep);
872 		}
873 	}
874 	return(NULL);
875 }
876 
877 /*
878  * Look up a pagedep. Return 1 if found, 0 if not found.
879  * If not found, allocate if DEPALLOC flag is passed.
880  * Found or allocated entry is returned in pagedeppp.
881  * This routine must be called with splbio interrupts blocked.
882  */
883 static int
884 pagedep_lookup(struct inode *ip, ufs_lbn_t lbn, int flags,
885 	       struct pagedep **pagedeppp)
886 {
887 	struct pagedep *pagedep;
888 	struct pagedep_hashhead *pagedephd;
889 	struct mount *mp;
890 	int i;
891 
892 #ifdef DEBUG
893 	if (lk.lkt_held == NOHOLDER)
894 		panic("pagedep_lookup: lock not held");
895 #endif
896 	mp = ITOV(ip)->v_mount;
897 	pagedephd = PAGEDEP_HASH(mp, ip->i_number, lbn);
898 top:
899 	*pagedeppp = pagedep_find(pagedephd, ip->i_number, lbn, mp);
900 	if (*pagedeppp)
901 		return(1);
902 	if ((flags & DEPALLOC) == 0)
903 		return (0);
904 	if (sema_get(&pagedep_in_progress, &lk) == 0) {
905 		ACQUIRE_LOCK(&lk);
906 		goto top;
907 	}
908 	MALLOC(pagedep, struct pagedep *, sizeof(struct pagedep), M_PAGEDEP,
909 		M_SOFTDEP_FLAGS | M_ZERO);
910 
911 	if (pagedep_find(pagedephd, ip->i_number, lbn, mp)) {
912 		kprintf("pagedep_lookup: blocking race avoided\n");
913 		ACQUIRE_LOCK(&lk);
914 		sema_release(&pagedep_in_progress);
915 		kfree(pagedep, M_PAGEDEP);
916 		goto top;
917 	}
918 
919 	pagedep->pd_list.wk_type = D_PAGEDEP;
920 	pagedep->pd_mnt = mp;
921 	pagedep->pd_ino = ip->i_number;
922 	pagedep->pd_lbn = lbn;
923 	LIST_INIT(&pagedep->pd_dirremhd);
924 	LIST_INIT(&pagedep->pd_pendinghd);
925 	for (i = 0; i < DAHASHSZ; i++)
926 		LIST_INIT(&pagedep->pd_diraddhd[i]);
927 	ACQUIRE_LOCK(&lk);
928 	LIST_INSERT_HEAD(pagedephd, pagedep, pd_hash);
929 	sema_release(&pagedep_in_progress);
930 	*pagedeppp = pagedep;
931 	return (0);
932 }
933 
934 /*
935  * Structures and routines associated with inodedep caching.
936  */
937 LIST_HEAD(inodedep_hashhead, inodedep) *inodedep_hashtbl;
938 static u_long	inodedep_hash;	/* size of hash table - 1 */
939 static long	num_inodedep;	/* number of inodedep allocated */
940 #define	INODEDEP_HASH(fs, inum) \
941       (&inodedep_hashtbl[((((register_t)(fs)) >> 13) + (inum)) & inodedep_hash])
942 static struct sema inodedep_in_progress;
943 
944 /*
945  * Helper routine for inodedep_lookup()
946  */
947 static __inline
948 struct inodedep *
949 inodedep_find(struct inodedep_hashhead *inodedephd, struct fs *fs, ino_t inum)
950 {
951 	struct inodedep *inodedep;
952 
953 	LIST_FOREACH(inodedep, inodedephd, id_hash) {
954 		if (inum == inodedep->id_ino && fs == inodedep->id_fs)
955 			return(inodedep);
956 	}
957 	return (NULL);
958 }
959 
960 /*
961  * Look up a inodedep. Return 1 if found, 0 if not found.
962  * If not found, allocate if DEPALLOC flag is passed.
963  * Found or allocated entry is returned in inodedeppp.
964  * This routine must be called with splbio interrupts blocked.
965  */
966 static int
967 inodedep_lookup(struct fs *fs, ino_t inum, int flags,
968 	        struct inodedep **inodedeppp)
969 {
970 	struct inodedep *inodedep;
971 	struct inodedep_hashhead *inodedephd;
972 	int firsttry;
973 
974 #ifdef DEBUG
975 	if (lk.lkt_held == NOHOLDER)
976 		panic("inodedep_lookup: lock not held");
977 #endif
978 	firsttry = 1;
979 	inodedephd = INODEDEP_HASH(fs, inum);
980 top:
981 	*inodedeppp = inodedep_find(inodedephd, fs, inum);
982 	if (*inodedeppp)
983 		return (1);
984 	if ((flags & DEPALLOC) == 0)
985 		return (0);
986 	/*
987 	 * If we are over our limit, try to improve the situation.
988 	 */
989 	if (num_inodedep > max_softdeps && firsttry &&
990 	    speedup_syncer() == 0 && (flags & NODELAY) == 0 &&
991 	    request_cleanup(FLUSH_INODES, 1)) {
992 		firsttry = 0;
993 		goto top;
994 	}
995 	if (sema_get(&inodedep_in_progress, &lk) == 0) {
996 		ACQUIRE_LOCK(&lk);
997 		goto top;
998 	}
999 	MALLOC(inodedep, struct inodedep *, sizeof(struct inodedep),
1000 		M_INODEDEP, M_SOFTDEP_FLAGS | M_ZERO);
1001 	if (inodedep_find(inodedephd, fs, inum)) {
1002 		kprintf("inodedep_lookup: blocking race avoided\n");
1003 		ACQUIRE_LOCK(&lk);
1004 		sema_release(&inodedep_in_progress);
1005 		kfree(inodedep, M_INODEDEP);
1006 		goto top;
1007 	}
1008 	inodedep->id_list.wk_type = D_INODEDEP;
1009 	inodedep->id_fs = fs;
1010 	inodedep->id_ino = inum;
1011 	inodedep->id_state = ALLCOMPLETE;
1012 	inodedep->id_nlinkdelta = 0;
1013 	inodedep->id_savedino = NULL;
1014 	inodedep->id_savedsize = -1;
1015 	inodedep->id_buf = NULL;
1016 	LIST_INIT(&inodedep->id_pendinghd);
1017 	LIST_INIT(&inodedep->id_inowait);
1018 	LIST_INIT(&inodedep->id_bufwait);
1019 	TAILQ_INIT(&inodedep->id_inoupdt);
1020 	TAILQ_INIT(&inodedep->id_newinoupdt);
1021 	ACQUIRE_LOCK(&lk);
1022 	num_inodedep += 1;
1023 	LIST_INSERT_HEAD(inodedephd, inodedep, id_hash);
1024 	sema_release(&inodedep_in_progress);
1025 	*inodedeppp = inodedep;
1026 	return (0);
1027 }
1028 
1029 /*
1030  * Structures and routines associated with newblk caching.
1031  */
1032 LIST_HEAD(newblk_hashhead, newblk) *newblk_hashtbl;
1033 u_long	newblk_hash;		/* size of hash table - 1 */
1034 #define	NEWBLK_HASH(fs, inum) \
1035 	(&newblk_hashtbl[((((register_t)(fs)) >> 13) + (inum)) & newblk_hash])
1036 static struct sema newblk_in_progress;
1037 
1038 /*
1039  * Helper routine for newblk_lookup()
1040  */
1041 static __inline
1042 struct newblk *
1043 newblk_find(struct newblk_hashhead *newblkhd, struct fs *fs,
1044 	    ufs_daddr_t newblkno)
1045 {
1046 	struct newblk *newblk;
1047 
1048 	LIST_FOREACH(newblk, newblkhd, nb_hash) {
1049 		if (newblkno == newblk->nb_newblkno && fs == newblk->nb_fs)
1050 			return (newblk);
1051 	}
1052 	return(NULL);
1053 }
1054 
1055 /*
1056  * Look up a newblk. Return 1 if found, 0 if not found.
1057  * If not found, allocate if DEPALLOC flag is passed.
1058  * Found or allocated entry is returned in newblkpp.
1059  */
1060 static int
1061 newblk_lookup(struct fs *fs, ufs_daddr_t newblkno, int flags,
1062 	      struct newblk **newblkpp)
1063 {
1064 	struct newblk *newblk;
1065 	struct newblk_hashhead *newblkhd;
1066 
1067 	newblkhd = NEWBLK_HASH(fs, newblkno);
1068 top:
1069 	*newblkpp = newblk_find(newblkhd, fs, newblkno);
1070 	if (*newblkpp)
1071 		return(1);
1072 	if ((flags & DEPALLOC) == 0)
1073 		return (0);
1074 	if (sema_get(&newblk_in_progress, 0) == 0)
1075 		goto top;
1076 	MALLOC(newblk, struct newblk *, sizeof(struct newblk),
1077 		M_NEWBLK, M_SOFTDEP_FLAGS | M_ZERO);
1078 
1079 	if (newblk_find(newblkhd, fs, newblkno)) {
1080 		kprintf("newblk_lookup: blocking race avoided\n");
1081 		sema_release(&pagedep_in_progress);
1082 		kfree(newblk, M_NEWBLK);
1083 		goto top;
1084 	}
1085 	newblk->nb_state = 0;
1086 	newblk->nb_fs = fs;
1087 	newblk->nb_newblkno = newblkno;
1088 	LIST_INSERT_HEAD(newblkhd, newblk, nb_hash);
1089 	sema_release(&newblk_in_progress);
1090 	*newblkpp = newblk;
1091 	return (0);
1092 }
1093 
1094 /*
1095  * Executed during filesystem system initialization before
1096  * mounting any filesystems.
1097  */
1098 void
1099 softdep_initialize(void)
1100 {
1101 	callout_init(&handle);
1102 	bioops = softdep_bioops;	/* XXX hack */
1103 
1104 	LIST_INIT(&mkdirlisthd);
1105 	LIST_INIT(&softdep_workitem_pending);
1106 	max_softdeps = min(desiredvnodes * 8,
1107 		M_INODEDEP->ks_limit / (2 * sizeof(struct inodedep)));
1108 	pagedep_hashtbl = hashinit(desiredvnodes / 5, M_PAGEDEP,
1109 	    &pagedep_hash);
1110 	sema_init(&pagedep_in_progress, "pagedep", 0, 0);
1111 	inodedep_hashtbl = hashinit(desiredvnodes, M_INODEDEP, &inodedep_hash);
1112 	sema_init(&inodedep_in_progress, "inodedep", 0, 0);
1113 	newblk_hashtbl = hashinit(64, M_NEWBLK, &newblk_hash);
1114 	sema_init(&newblk_in_progress, "newblk", 0, 0);
1115 }
1116 
1117 /*
1118  * Called at mount time to notify the dependency code that a
1119  * filesystem wishes to use it.
1120  */
1121 int
1122 softdep_mount(struct vnode *devvp, struct mount *mp, struct fs *fs)
1123 {
1124 	struct csum cstotal;
1125 	struct cg *cgp;
1126 	struct buf *bp;
1127 	int error, cyl;
1128 
1129 	mp->mnt_flag &= ~MNT_ASYNC;
1130 	mp->mnt_flag |= MNT_SOFTDEP;
1131 	/*
1132 	 * When doing soft updates, the counters in the
1133 	 * superblock may have gotten out of sync, so we have
1134 	 * to scan the cylinder groups and recalculate them.
1135 	 */
1136 	if (fs->fs_clean != 0)
1137 		return (0);
1138 	bzero(&cstotal, sizeof cstotal);
1139 	for (cyl = 0; cyl < fs->fs_ncg; cyl++) {
1140 		if ((error = bread(devvp, fsbtodoff(fs, cgtod(fs, cyl)),
1141 				   fs->fs_cgsize, &bp)) != 0) {
1142 			brelse(bp);
1143 			return (error);
1144 		}
1145 		cgp = (struct cg *)bp->b_data;
1146 		cstotal.cs_nffree += cgp->cg_cs.cs_nffree;
1147 		cstotal.cs_nbfree += cgp->cg_cs.cs_nbfree;
1148 		cstotal.cs_nifree += cgp->cg_cs.cs_nifree;
1149 		cstotal.cs_ndir += cgp->cg_cs.cs_ndir;
1150 		fs->fs_cs(fs, cyl) = cgp->cg_cs;
1151 		brelse(bp);
1152 	}
1153 #ifdef DEBUG
1154 	if (bcmp(&cstotal, &fs->fs_cstotal, sizeof cstotal))
1155 		kprintf("ffs_mountfs: superblock updated for soft updates\n");
1156 #endif
1157 	bcopy(&cstotal, &fs->fs_cstotal, sizeof cstotal);
1158 	return (0);
1159 }
1160 
1161 /*
1162  * Protecting the freemaps (or bitmaps).
1163  *
1164  * To eliminate the need to execute fsck before mounting a filesystem
1165  * after a power failure, one must (conservatively) guarantee that the
1166  * on-disk copy of the bitmaps never indicate that a live inode or block is
1167  * free.  So, when a block or inode is allocated, the bitmap should be
1168  * updated (on disk) before any new pointers.  When a block or inode is
1169  * freed, the bitmap should not be updated until all pointers have been
1170  * reset.  The latter dependency is handled by the delayed de-allocation
1171  * approach described below for block and inode de-allocation.  The former
1172  * dependency is handled by calling the following procedure when a block or
1173  * inode is allocated. When an inode is allocated an "inodedep" is created
1174  * with its DEPCOMPLETE flag cleared until its bitmap is written to disk.
1175  * Each "inodedep" is also inserted into the hash indexing structure so
1176  * that any additional link additions can be made dependent on the inode
1177  * allocation.
1178  *
1179  * The ufs filesystem maintains a number of free block counts (e.g., per
1180  * cylinder group, per cylinder and per <cylinder, rotational position> pair)
1181  * in addition to the bitmaps.  These counts are used to improve efficiency
1182  * during allocation and therefore must be consistent with the bitmaps.
1183  * There is no convenient way to guarantee post-crash consistency of these
1184  * counts with simple update ordering, for two main reasons: (1) The counts
1185  * and bitmaps for a single cylinder group block are not in the same disk
1186  * sector.  If a disk write is interrupted (e.g., by power failure), one may
1187  * be written and the other not.  (2) Some of the counts are located in the
1188  * superblock rather than the cylinder group block. So, we focus our soft
1189  * updates implementation on protecting the bitmaps. When mounting a
1190  * filesystem, we recompute the auxiliary counts from the bitmaps.
1191  */
1192 
1193 /*
1194  * Called just after updating the cylinder group block to allocate an inode.
1195  *
1196  * Parameters:
1197  *	bp:		buffer for cylgroup block with inode map
1198  *	ip:		inode related to allocation
1199  *	newinum:	new inode number being allocated
1200  */
1201 void
1202 softdep_setup_inomapdep(struct buf *bp, struct inode *ip, ino_t newinum)
1203 {
1204 	struct inodedep *inodedep;
1205 	struct bmsafemap *bmsafemap;
1206 
1207 	/*
1208 	 * Create a dependency for the newly allocated inode.
1209 	 * Panic if it already exists as something is seriously wrong.
1210 	 * Otherwise add it to the dependency list for the buffer holding
1211 	 * the cylinder group map from which it was allocated.
1212 	 */
1213 	ACQUIRE_LOCK(&lk);
1214 	if ((inodedep_lookup(ip->i_fs, newinum, DEPALLOC|NODELAY, &inodedep))) {
1215 		FREE_LOCK(&lk);
1216 		panic("softdep_setup_inomapdep: found inode");
1217 	}
1218 	inodedep->id_buf = bp;
1219 	inodedep->id_state &= ~DEPCOMPLETE;
1220 	bmsafemap = bmsafemap_lookup(bp);
1221 	LIST_INSERT_HEAD(&bmsafemap->sm_inodedephd, inodedep, id_deps);
1222 	FREE_LOCK(&lk);
1223 }
1224 
1225 /*
1226  * Called just after updating the cylinder group block to
1227  * allocate block or fragment.
1228  *
1229  * Parameters:
1230  *	bp:		buffer for cylgroup block with block map
1231  *	fs:		filesystem doing allocation
1232  *	newblkno:	number of newly allocated block
1233  */
1234 void
1235 softdep_setup_blkmapdep(struct buf *bp, struct fs *fs,
1236 			ufs_daddr_t newblkno)
1237 {
1238 	struct newblk *newblk;
1239 	struct bmsafemap *bmsafemap;
1240 
1241 	/*
1242 	 * Create a dependency for the newly allocated block.
1243 	 * Add it to the dependency list for the buffer holding
1244 	 * the cylinder group map from which it was allocated.
1245 	 */
1246 	if (newblk_lookup(fs, newblkno, DEPALLOC, &newblk) != 0)
1247 		panic("softdep_setup_blkmapdep: found block");
1248 	ACQUIRE_LOCK(&lk);
1249 	newblk->nb_bmsafemap = bmsafemap = bmsafemap_lookup(bp);
1250 	LIST_INSERT_HEAD(&bmsafemap->sm_newblkhd, newblk, nb_deps);
1251 	FREE_LOCK(&lk);
1252 }
1253 
1254 /*
1255  * Find the bmsafemap associated with a cylinder group buffer.
1256  * If none exists, create one. The buffer must be locked when
1257  * this routine is called and this routine must be called with
1258  * splbio interrupts blocked.
1259  */
1260 static struct bmsafemap *
1261 bmsafemap_lookup(struct buf *bp)
1262 {
1263 	struct bmsafemap *bmsafemap;
1264 	struct worklist *wk;
1265 
1266 #ifdef DEBUG
1267 	if (lk.lkt_held == NOHOLDER)
1268 		panic("bmsafemap_lookup: lock not held");
1269 #endif
1270 	LIST_FOREACH(wk, &bp->b_dep, wk_list)
1271 		if (wk->wk_type == D_BMSAFEMAP)
1272 			return (WK_BMSAFEMAP(wk));
1273 	FREE_LOCK(&lk);
1274 	MALLOC(bmsafemap, struct bmsafemap *, sizeof(struct bmsafemap),
1275 		M_BMSAFEMAP, M_SOFTDEP_FLAGS);
1276 	bmsafemap->sm_list.wk_type = D_BMSAFEMAP;
1277 	bmsafemap->sm_list.wk_state = 0;
1278 	bmsafemap->sm_buf = bp;
1279 	LIST_INIT(&bmsafemap->sm_allocdirecthd);
1280 	LIST_INIT(&bmsafemap->sm_allocindirhd);
1281 	LIST_INIT(&bmsafemap->sm_inodedephd);
1282 	LIST_INIT(&bmsafemap->sm_newblkhd);
1283 	ACQUIRE_LOCK(&lk);
1284 	WORKLIST_INSERT(&bp->b_dep, &bmsafemap->sm_list);
1285 	return (bmsafemap);
1286 }
1287 
1288 /*
1289  * Direct block allocation dependencies.
1290  *
1291  * When a new block is allocated, the corresponding disk locations must be
1292  * initialized (with zeros or new data) before the on-disk inode points to
1293  * them.  Also, the freemap from which the block was allocated must be
1294  * updated (on disk) before the inode's pointer. These two dependencies are
1295  * independent of each other and are needed for all file blocks and indirect
1296  * blocks that are pointed to directly by the inode.  Just before the
1297  * "in-core" version of the inode is updated with a newly allocated block
1298  * number, a procedure (below) is called to setup allocation dependency
1299  * structures.  These structures are removed when the corresponding
1300  * dependencies are satisfied or when the block allocation becomes obsolete
1301  * (i.e., the file is deleted, the block is de-allocated, or the block is a
1302  * fragment that gets upgraded).  All of these cases are handled in
1303  * procedures described later.
1304  *
1305  * When a file extension causes a fragment to be upgraded, either to a larger
1306  * fragment or to a full block, the on-disk location may change (if the
1307  * previous fragment could not simply be extended). In this case, the old
1308  * fragment must be de-allocated, but not until after the inode's pointer has
1309  * been updated. In most cases, this is handled by later procedures, which
1310  * will construct a "freefrag" structure to be added to the workitem queue
1311  * when the inode update is complete (or obsolete).  The main exception to
1312  * this is when an allocation occurs while a pending allocation dependency
1313  * (for the same block pointer) remains.  This case is handled in the main
1314  * allocation dependency setup procedure by immediately freeing the
1315  * unreferenced fragments.
1316  *
1317  * Parameters:
1318  *	ip:		inode to which block is being added
1319  *	lbn:		block pointer within inode
1320  *	newblkno:	disk block number being added
1321  *	oldblkno:	previous block number, 0 unless frag
1322  *	newsize:	size of new block
1323  *	oldsize:	size of new block
1324  *	bp:		bp for allocated block
1325  */
1326 void
1327 softdep_setup_allocdirect(struct inode *ip, ufs_lbn_t lbn, ufs_daddr_t newblkno,
1328 			  ufs_daddr_t oldblkno, long newsize, long oldsize,
1329 			  struct buf *bp)
1330 {
1331 	struct allocdirect *adp, *oldadp;
1332 	struct allocdirectlst *adphead;
1333 	struct bmsafemap *bmsafemap;
1334 	struct inodedep *inodedep;
1335 	struct pagedep *pagedep;
1336 	struct newblk *newblk;
1337 
1338 	MALLOC(adp, struct allocdirect *, sizeof(struct allocdirect),
1339 		M_ALLOCDIRECT, M_SOFTDEP_FLAGS);
1340 	bzero(adp, sizeof(struct allocdirect));
1341 	adp->ad_list.wk_type = D_ALLOCDIRECT;
1342 	adp->ad_lbn = lbn;
1343 	adp->ad_newblkno = newblkno;
1344 	adp->ad_oldblkno = oldblkno;
1345 	adp->ad_newsize = newsize;
1346 	adp->ad_oldsize = oldsize;
1347 	adp->ad_state = ATTACHED;
1348 	if (newblkno == oldblkno)
1349 		adp->ad_freefrag = NULL;
1350 	else
1351 		adp->ad_freefrag = newfreefrag(ip, oldblkno, oldsize);
1352 
1353 	if (newblk_lookup(ip->i_fs, newblkno, 0, &newblk) == 0)
1354 		panic("softdep_setup_allocdirect: lost block");
1355 
1356 	ACQUIRE_LOCK(&lk);
1357 	inodedep_lookup(ip->i_fs, ip->i_number, DEPALLOC | NODELAY, &inodedep);
1358 	adp->ad_inodedep = inodedep;
1359 
1360 	if (newblk->nb_state == DEPCOMPLETE) {
1361 		adp->ad_state |= DEPCOMPLETE;
1362 		adp->ad_buf = NULL;
1363 	} else {
1364 		bmsafemap = newblk->nb_bmsafemap;
1365 		adp->ad_buf = bmsafemap->sm_buf;
1366 		LIST_REMOVE(newblk, nb_deps);
1367 		LIST_INSERT_HEAD(&bmsafemap->sm_allocdirecthd, adp, ad_deps);
1368 	}
1369 	LIST_REMOVE(newblk, nb_hash);
1370 	FREE(newblk, M_NEWBLK);
1371 
1372 	WORKLIST_INSERT(&bp->b_dep, &adp->ad_list);
1373 	if (lbn >= NDADDR) {
1374 		/* allocating an indirect block */
1375 		if (oldblkno != 0) {
1376 			FREE_LOCK(&lk);
1377 			panic("softdep_setup_allocdirect: non-zero indir");
1378 		}
1379 	} else {
1380 		/*
1381 		 * Allocating a direct block.
1382 		 *
1383 		 * If we are allocating a directory block, then we must
1384 		 * allocate an associated pagedep to track additions and
1385 		 * deletions.
1386 		 */
1387 		if ((ip->i_mode & IFMT) == IFDIR &&
1388 		    pagedep_lookup(ip, lbn, DEPALLOC, &pagedep) == 0)
1389 			WORKLIST_INSERT(&bp->b_dep, &pagedep->pd_list);
1390 	}
1391 	/*
1392 	 * The list of allocdirects must be kept in sorted and ascending
1393 	 * order so that the rollback routines can quickly determine the
1394 	 * first uncommitted block (the size of the file stored on disk
1395 	 * ends at the end of the lowest committed fragment, or if there
1396 	 * are no fragments, at the end of the highest committed block).
1397 	 * Since files generally grow, the typical case is that the new
1398 	 * block is to be added at the end of the list. We speed this
1399 	 * special case by checking against the last allocdirect in the
1400 	 * list before laboriously traversing the list looking for the
1401 	 * insertion point.
1402 	 */
1403 	adphead = &inodedep->id_newinoupdt;
1404 	oldadp = TAILQ_LAST(adphead, allocdirectlst);
1405 	if (oldadp == NULL || oldadp->ad_lbn <= lbn) {
1406 		/* insert at end of list */
1407 		TAILQ_INSERT_TAIL(adphead, adp, ad_next);
1408 		if (oldadp != NULL && oldadp->ad_lbn == lbn)
1409 			allocdirect_merge(adphead, adp, oldadp);
1410 		FREE_LOCK(&lk);
1411 		return;
1412 	}
1413 	TAILQ_FOREACH(oldadp, adphead, ad_next) {
1414 		if (oldadp->ad_lbn >= lbn)
1415 			break;
1416 	}
1417 	if (oldadp == NULL) {
1418 		FREE_LOCK(&lk);
1419 		panic("softdep_setup_allocdirect: lost entry");
1420 	}
1421 	/* insert in middle of list */
1422 	TAILQ_INSERT_BEFORE(oldadp, adp, ad_next);
1423 	if (oldadp->ad_lbn == lbn)
1424 		allocdirect_merge(adphead, adp, oldadp);
1425 	FREE_LOCK(&lk);
1426 }
1427 
1428 /*
1429  * Replace an old allocdirect dependency with a newer one.
1430  * This routine must be called with splbio interrupts blocked.
1431  *
1432  * Parameters:
1433  *	adphead:	head of list holding allocdirects
1434  *	newadp:		allocdirect being added
1435  *	oldadp:		existing allocdirect being checked
1436  */
1437 static void
1438 allocdirect_merge(struct allocdirectlst *adphead,
1439 		  struct allocdirect *newadp,
1440 		  struct allocdirect *oldadp)
1441 {
1442 	struct freefrag *freefrag;
1443 
1444 #ifdef DEBUG
1445 	if (lk.lkt_held == NOHOLDER)
1446 		panic("allocdirect_merge: lock not held");
1447 #endif
1448 	if (newadp->ad_oldblkno != oldadp->ad_newblkno ||
1449 	    newadp->ad_oldsize != oldadp->ad_newsize ||
1450 	    newadp->ad_lbn >= NDADDR) {
1451 		FREE_LOCK(&lk);
1452 		panic("allocdirect_check: old %d != new %d || lbn %ld >= %d",
1453 		    newadp->ad_oldblkno, oldadp->ad_newblkno, newadp->ad_lbn,
1454 		    NDADDR);
1455 	}
1456 	newadp->ad_oldblkno = oldadp->ad_oldblkno;
1457 	newadp->ad_oldsize = oldadp->ad_oldsize;
1458 	/*
1459 	 * If the old dependency had a fragment to free or had never
1460 	 * previously had a block allocated, then the new dependency
1461 	 * can immediately post its freefrag and adopt the old freefrag.
1462 	 * This action is done by swapping the freefrag dependencies.
1463 	 * The new dependency gains the old one's freefrag, and the
1464 	 * old one gets the new one and then immediately puts it on
1465 	 * the worklist when it is freed by free_allocdirect. It is
1466 	 * not possible to do this swap when the old dependency had a
1467 	 * non-zero size but no previous fragment to free. This condition
1468 	 * arises when the new block is an extension of the old block.
1469 	 * Here, the first part of the fragment allocated to the new
1470 	 * dependency is part of the block currently claimed on disk by
1471 	 * the old dependency, so cannot legitimately be freed until the
1472 	 * conditions for the new dependency are fulfilled.
1473 	 */
1474 	if (oldadp->ad_freefrag != NULL || oldadp->ad_oldblkno == 0) {
1475 		freefrag = newadp->ad_freefrag;
1476 		newadp->ad_freefrag = oldadp->ad_freefrag;
1477 		oldadp->ad_freefrag = freefrag;
1478 	}
1479 	free_allocdirect(adphead, oldadp, 0);
1480 }
1481 
1482 /*
1483  * Allocate a new freefrag structure if needed.
1484  */
1485 static struct freefrag *
1486 newfreefrag(struct inode *ip, ufs_daddr_t blkno, long size)
1487 {
1488 	struct freefrag *freefrag;
1489 	struct fs *fs;
1490 
1491 	if (blkno == 0)
1492 		return (NULL);
1493 	fs = ip->i_fs;
1494 	if (fragnum(fs, blkno) + numfrags(fs, size) > fs->fs_frag)
1495 		panic("newfreefrag: frag size");
1496 	MALLOC(freefrag, struct freefrag *, sizeof(struct freefrag),
1497 		M_FREEFRAG, M_SOFTDEP_FLAGS);
1498 	freefrag->ff_list.wk_type = D_FREEFRAG;
1499 	freefrag->ff_state = ip->i_uid & ~ONWORKLIST;	/* XXX - used below */
1500 	freefrag->ff_inum = ip->i_number;
1501 	freefrag->ff_fs = fs;
1502 	freefrag->ff_devvp = ip->i_devvp;
1503 	freefrag->ff_blkno = blkno;
1504 	freefrag->ff_fragsize = size;
1505 	return (freefrag);
1506 }
1507 
1508 /*
1509  * This workitem de-allocates fragments that were replaced during
1510  * file block allocation.
1511  */
1512 static void
1513 handle_workitem_freefrag(struct freefrag *freefrag)
1514 {
1515 	struct inode tip;
1516 
1517 	tip.i_fs = freefrag->ff_fs;
1518 	tip.i_devvp = freefrag->ff_devvp;
1519 	tip.i_dev = freefrag->ff_devvp->v_rdev;
1520 	tip.i_number = freefrag->ff_inum;
1521 	tip.i_uid = freefrag->ff_state & ~ONWORKLIST;	/* XXX - set above */
1522 	ffs_blkfree(&tip, freefrag->ff_blkno, freefrag->ff_fragsize);
1523 	FREE(freefrag, M_FREEFRAG);
1524 }
1525 
1526 /*
1527  * Indirect block allocation dependencies.
1528  *
1529  * The same dependencies that exist for a direct block also exist when
1530  * a new block is allocated and pointed to by an entry in a block of
1531  * indirect pointers. The undo/redo states described above are also
1532  * used here. Because an indirect block contains many pointers that
1533  * may have dependencies, a second copy of the entire in-memory indirect
1534  * block is kept. The buffer cache copy is always completely up-to-date.
1535  * The second copy, which is used only as a source for disk writes,
1536  * contains only the safe pointers (i.e., those that have no remaining
1537  * update dependencies). The second copy is freed when all pointers
1538  * are safe. The cache is not allowed to replace indirect blocks with
1539  * pending update dependencies. If a buffer containing an indirect
1540  * block with dependencies is written, these routines will mark it
1541  * dirty again. It can only be successfully written once all the
1542  * dependencies are removed. The ffs_fsync routine in conjunction with
1543  * softdep_sync_metadata work together to get all the dependencies
1544  * removed so that a file can be successfully written to disk. Three
1545  * procedures are used when setting up indirect block pointer
1546  * dependencies. The division is necessary because of the organization
1547  * of the "balloc" routine and because of the distinction between file
1548  * pages and file metadata blocks.
1549  */
1550 
1551 /*
1552  * Allocate a new allocindir structure.
1553  *
1554  * Parameters:
1555  *	ip:		inode for file being extended
1556  *	ptrno:		offset of pointer in indirect block
1557  *	newblkno:	disk block number being added
1558  *	oldblkno:	previous block number, 0 if none
1559  */
1560 static struct allocindir *
1561 newallocindir(struct inode *ip, int ptrno, ufs_daddr_t newblkno,
1562 	      ufs_daddr_t oldblkno)
1563 {
1564 	struct allocindir *aip;
1565 
1566 	MALLOC(aip, struct allocindir *, sizeof(struct allocindir),
1567 		M_ALLOCINDIR, M_SOFTDEP_FLAGS);
1568 	bzero(aip, sizeof(struct allocindir));
1569 	aip->ai_list.wk_type = D_ALLOCINDIR;
1570 	aip->ai_state = ATTACHED;
1571 	aip->ai_offset = ptrno;
1572 	aip->ai_newblkno = newblkno;
1573 	aip->ai_oldblkno = oldblkno;
1574 	aip->ai_freefrag = newfreefrag(ip, oldblkno, ip->i_fs->fs_bsize);
1575 	return (aip);
1576 }
1577 
1578 /*
1579  * Called just before setting an indirect block pointer
1580  * to a newly allocated file page.
1581  *
1582  * Parameters:
1583  *	ip:		inode for file being extended
1584  *	lbn:		allocated block number within file
1585  *	bp:		buffer with indirect blk referencing page
1586  *	ptrno:		offset of pointer in indirect block
1587  *	newblkno:	disk block number being added
1588  *	oldblkno:	previous block number, 0 if none
1589  *	nbp:		buffer holding allocated page
1590  */
1591 void
1592 softdep_setup_allocindir_page(struct inode *ip, ufs_lbn_t lbn,
1593 			      struct buf *bp, int ptrno,
1594 			      ufs_daddr_t newblkno, ufs_daddr_t oldblkno,
1595 			      struct buf *nbp)
1596 {
1597 	struct allocindir *aip;
1598 	struct pagedep *pagedep;
1599 
1600 	aip = newallocindir(ip, ptrno, newblkno, oldblkno);
1601 	ACQUIRE_LOCK(&lk);
1602 	/*
1603 	 * If we are allocating a directory page, then we must
1604 	 * allocate an associated pagedep to track additions and
1605 	 * deletions.
1606 	 */
1607 	if ((ip->i_mode & IFMT) == IFDIR &&
1608 	    pagedep_lookup(ip, lbn, DEPALLOC, &pagedep) == 0)
1609 		WORKLIST_INSERT(&nbp->b_dep, &pagedep->pd_list);
1610 	WORKLIST_INSERT(&nbp->b_dep, &aip->ai_list);
1611 	FREE_LOCK(&lk);
1612 	setup_allocindir_phase2(bp, ip, aip);
1613 }
1614 
1615 /*
1616  * Called just before setting an indirect block pointer to a
1617  * newly allocated indirect block.
1618  * Parameters:
1619  *	nbp:		newly allocated indirect block
1620  *	ip:		inode for file being extended
1621  *	bp:		indirect block referencing allocated block
1622  *	ptrno:		offset of pointer in indirect block
1623  *	newblkno:	disk block number being added
1624  */
1625 void
1626 softdep_setup_allocindir_meta(struct buf *nbp, struct inode *ip,
1627 			      struct buf *bp, int ptrno,
1628 			      ufs_daddr_t newblkno)
1629 {
1630 	struct allocindir *aip;
1631 
1632 	aip = newallocindir(ip, ptrno, newblkno, 0);
1633 	ACQUIRE_LOCK(&lk);
1634 	WORKLIST_INSERT(&nbp->b_dep, &aip->ai_list);
1635 	FREE_LOCK(&lk);
1636 	setup_allocindir_phase2(bp, ip, aip);
1637 }
1638 
1639 /*
1640  * Called to finish the allocation of the "aip" allocated
1641  * by one of the two routines above.
1642  *
1643  * Parameters:
1644  *	bp:	in-memory copy of the indirect block
1645  *	ip:	inode for file being extended
1646  *	aip:	allocindir allocated by the above routines
1647  */
1648 static void
1649 setup_allocindir_phase2(struct buf *bp, struct inode *ip,
1650 			struct allocindir *aip)
1651 {
1652 	struct worklist *wk;
1653 	struct indirdep *indirdep, *newindirdep;
1654 	struct bmsafemap *bmsafemap;
1655 	struct allocindir *oldaip;
1656 	struct freefrag *freefrag;
1657 	struct newblk *newblk;
1658 
1659 	if (bp->b_loffset >= 0)
1660 		panic("setup_allocindir_phase2: not indir blk");
1661 	for (indirdep = NULL, newindirdep = NULL; ; ) {
1662 		ACQUIRE_LOCK(&lk);
1663 		LIST_FOREACH(wk, &bp->b_dep, wk_list) {
1664 			if (wk->wk_type != D_INDIRDEP)
1665 				continue;
1666 			indirdep = WK_INDIRDEP(wk);
1667 			break;
1668 		}
1669 		if (indirdep == NULL && newindirdep) {
1670 			indirdep = newindirdep;
1671 			WORKLIST_INSERT(&bp->b_dep, &indirdep->ir_list);
1672 			newindirdep = NULL;
1673 		}
1674 		FREE_LOCK(&lk);
1675 		if (indirdep) {
1676 			if (newblk_lookup(ip->i_fs, aip->ai_newblkno, 0,
1677 			    &newblk) == 0)
1678 				panic("setup_allocindir: lost block");
1679 			ACQUIRE_LOCK(&lk);
1680 			if (newblk->nb_state == DEPCOMPLETE) {
1681 				aip->ai_state |= DEPCOMPLETE;
1682 				aip->ai_buf = NULL;
1683 			} else {
1684 				bmsafemap = newblk->nb_bmsafemap;
1685 				aip->ai_buf = bmsafemap->sm_buf;
1686 				LIST_REMOVE(newblk, nb_deps);
1687 				LIST_INSERT_HEAD(&bmsafemap->sm_allocindirhd,
1688 				    aip, ai_deps);
1689 			}
1690 			LIST_REMOVE(newblk, nb_hash);
1691 			FREE(newblk, M_NEWBLK);
1692 			aip->ai_indirdep = indirdep;
1693 			/*
1694 			 * Check to see if there is an existing dependency
1695 			 * for this block. If there is, merge the old
1696 			 * dependency into the new one.
1697 			 */
1698 			if (aip->ai_oldblkno == 0)
1699 				oldaip = NULL;
1700 			else
1701 
1702 				LIST_FOREACH(oldaip, &indirdep->ir_deplisthd, ai_next)
1703 					if (oldaip->ai_offset == aip->ai_offset)
1704 						break;
1705 			if (oldaip != NULL) {
1706 				if (oldaip->ai_newblkno != aip->ai_oldblkno) {
1707 					FREE_LOCK(&lk);
1708 					panic("setup_allocindir_phase2: blkno");
1709 				}
1710 				aip->ai_oldblkno = oldaip->ai_oldblkno;
1711 				freefrag = oldaip->ai_freefrag;
1712 				oldaip->ai_freefrag = aip->ai_freefrag;
1713 				aip->ai_freefrag = freefrag;
1714 				free_allocindir(oldaip, NULL);
1715 			}
1716 			LIST_INSERT_HEAD(&indirdep->ir_deplisthd, aip, ai_next);
1717 			((ufs_daddr_t *)indirdep->ir_savebp->b_data)
1718 			    [aip->ai_offset] = aip->ai_oldblkno;
1719 			FREE_LOCK(&lk);
1720 		}
1721 		if (newindirdep) {
1722 			/*
1723 			 * Avoid any possibility of data corruption by
1724 			 * ensuring that our old version is thrown away.
1725 			 */
1726 			newindirdep->ir_savebp->b_flags |= B_INVAL | B_NOCACHE;
1727 			brelse(newindirdep->ir_savebp);
1728 			WORKITEM_FREE((caddr_t)newindirdep, D_INDIRDEP);
1729 		}
1730 		if (indirdep)
1731 			break;
1732 		MALLOC(newindirdep, struct indirdep *, sizeof(struct indirdep),
1733 			M_INDIRDEP, M_SOFTDEP_FLAGS);
1734 		newindirdep->ir_list.wk_type = D_INDIRDEP;
1735 		newindirdep->ir_state = ATTACHED;
1736 		LIST_INIT(&newindirdep->ir_deplisthd);
1737 		LIST_INIT(&newindirdep->ir_donehd);
1738 		if (bp->b_bio2.bio_offset == NOOFFSET) {
1739 			VOP_BMAP(bp->b_vp, bp->b_bio1.bio_offset,
1740 				 &bp->b_bio2.bio_offset, NULL, NULL);
1741 		}
1742 		KKASSERT(bp->b_bio2.bio_offset != NOOFFSET);
1743 		newindirdep->ir_savebp = getblk(ip->i_devvp,
1744 						bp->b_bio2.bio_offset,
1745 					        bp->b_bcount, 0, 0);
1746 		BUF_KERNPROC(newindirdep->ir_savebp);
1747 		bcopy(bp->b_data, newindirdep->ir_savebp->b_data, bp->b_bcount);
1748 	}
1749 }
1750 
1751 /*
1752  * Block de-allocation dependencies.
1753  *
1754  * When blocks are de-allocated, the on-disk pointers must be nullified before
1755  * the blocks are made available for use by other files.  (The true
1756  * requirement is that old pointers must be nullified before new on-disk
1757  * pointers are set.  We chose this slightly more stringent requirement to
1758  * reduce complexity.) Our implementation handles this dependency by updating
1759  * the inode (or indirect block) appropriately but delaying the actual block
1760  * de-allocation (i.e., freemap and free space count manipulation) until
1761  * after the updated versions reach stable storage.  After the disk is
1762  * updated, the blocks can be safely de-allocated whenever it is convenient.
1763  * This implementation handles only the common case of reducing a file's
1764  * length to zero. Other cases are handled by the conventional synchronous
1765  * write approach.
1766  *
1767  * The ffs implementation with which we worked double-checks
1768  * the state of the block pointers and file size as it reduces
1769  * a file's length.  Some of this code is replicated here in our
1770  * soft updates implementation.  The freeblks->fb_chkcnt field is
1771  * used to transfer a part of this information to the procedure
1772  * that eventually de-allocates the blocks.
1773  *
1774  * This routine should be called from the routine that shortens
1775  * a file's length, before the inode's size or block pointers
1776  * are modified. It will save the block pointer information for
1777  * later release and zero the inode so that the calling routine
1778  * can release it.
1779  */
1780 struct softdep_setup_freeblocks_info {
1781 	struct fs *fs;
1782 	struct inode *ip;
1783 };
1784 
1785 static int softdep_setup_freeblocks_bp(struct buf *bp, void *data);
1786 
1787 /*
1788  * Parameters:
1789  *	ip:	The inode whose length is to be reduced
1790  *	length:	The new length for the file
1791  */
1792 void
1793 softdep_setup_freeblocks(struct inode *ip, off_t length)
1794 {
1795 	struct softdep_setup_freeblocks_info info;
1796 	struct freeblks *freeblks;
1797 	struct inodedep *inodedep;
1798 	struct allocdirect *adp;
1799 	struct vnode *vp;
1800 	struct buf *bp;
1801 	struct fs *fs;
1802 	int i, error, delay;
1803 	int count;
1804 
1805 	fs = ip->i_fs;
1806 	if (length != 0)
1807 		panic("softde_setup_freeblocks: non-zero length");
1808 	MALLOC(freeblks, struct freeblks *, sizeof(struct freeblks),
1809 		M_FREEBLKS, M_SOFTDEP_FLAGS);
1810 	bzero(freeblks, sizeof(struct freeblks));
1811 	freeblks->fb_list.wk_type = D_FREEBLKS;
1812 	freeblks->fb_state = ATTACHED;
1813 	freeblks->fb_uid = ip->i_uid;
1814 	freeblks->fb_previousinum = ip->i_number;
1815 	freeblks->fb_devvp = ip->i_devvp;
1816 	freeblks->fb_fs = fs;
1817 	freeblks->fb_oldsize = ip->i_size;
1818 	freeblks->fb_newsize = length;
1819 	freeblks->fb_chkcnt = ip->i_blocks;
1820 	for (i = 0; i < NDADDR; i++) {
1821 		freeblks->fb_dblks[i] = ip->i_db[i];
1822 		ip->i_db[i] = 0;
1823 	}
1824 	for (i = 0; i < NIADDR; i++) {
1825 		freeblks->fb_iblks[i] = ip->i_ib[i];
1826 		ip->i_ib[i] = 0;
1827 	}
1828 	ip->i_blocks = 0;
1829 	ip->i_size = 0;
1830 	/*
1831 	 * Push the zero'ed inode to to its disk buffer so that we are free
1832 	 * to delete its dependencies below. Once the dependencies are gone
1833 	 * the buffer can be safely released.
1834 	 */
1835 	if ((error = bread(ip->i_devvp,
1836 			    fsbtodoff(fs, ino_to_fsba(fs, ip->i_number)),
1837 	    (int)fs->fs_bsize, &bp)) != 0)
1838 		softdep_error("softdep_setup_freeblocks", error);
1839 	*((struct ufs1_dinode *)bp->b_data + ino_to_fsbo(fs, ip->i_number)) =
1840 	    ip->i_din;
1841 	/*
1842 	 * Find and eliminate any inode dependencies.
1843 	 */
1844 	ACQUIRE_LOCK(&lk);
1845 	(void) inodedep_lookup(fs, ip->i_number, DEPALLOC, &inodedep);
1846 	if ((inodedep->id_state & IOSTARTED) != 0) {
1847 		FREE_LOCK(&lk);
1848 		panic("softdep_setup_freeblocks: inode busy");
1849 	}
1850 	/*
1851 	 * Add the freeblks structure to the list of operations that
1852 	 * must await the zero'ed inode being written to disk. If we
1853 	 * still have a bitmap dependency (delay == 0), then the inode
1854 	 * has never been written to disk, so we can process the
1855 	 * freeblks below once we have deleted the dependencies.
1856 	 */
1857 	delay = (inodedep->id_state & DEPCOMPLETE);
1858 	if (delay)
1859 		WORKLIST_INSERT(&inodedep->id_bufwait, &freeblks->fb_list);
1860 	/*
1861 	 * Because the file length has been truncated to zero, any
1862 	 * pending block allocation dependency structures associated
1863 	 * with this inode are obsolete and can simply be de-allocated.
1864 	 * We must first merge the two dependency lists to get rid of
1865 	 * any duplicate freefrag structures, then purge the merged list.
1866 	 */
1867 	merge_inode_lists(inodedep);
1868 	while ((adp = TAILQ_FIRST(&inodedep->id_inoupdt)) != 0)
1869 		free_allocdirect(&inodedep->id_inoupdt, adp, 1);
1870 	FREE_LOCK(&lk);
1871 	bdwrite(bp);
1872 	/*
1873 	 * We must wait for any I/O in progress to finish so that
1874 	 * all potential buffers on the dirty list will be visible.
1875 	 * Once they are all there, walk the list and get rid of
1876 	 * any dependencies.
1877 	 */
1878 	vp = ITOV(ip);
1879 	ACQUIRE_LOCK(&lk);
1880 	drain_output(vp, 1);
1881 
1882 	info.fs = fs;
1883 	info.ip = ip;
1884 	do {
1885 		count = RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree, NULL,
1886 				softdep_setup_freeblocks_bp, &info);
1887 	} while (count != 0);
1888 	if (inodedep_lookup(fs, ip->i_number, 0, &inodedep) != 0)
1889 		(void)free_inodedep(inodedep);
1890 
1891 	if (delay) {
1892 		freeblks->fb_state |= DEPCOMPLETE;
1893 		/*
1894 		 * If the inode with zeroed block pointers is now on disk
1895 		 * we can start freeing blocks. Add freeblks to the worklist
1896 		 * instead of calling  handle_workitem_freeblocks directly as
1897 		 * it is more likely that additional IO is needed to complete
1898 		 * the request here than in the !delay case.
1899 		 */
1900 		if ((freeblks->fb_state & ALLCOMPLETE) == ALLCOMPLETE)
1901 			add_to_worklist(&freeblks->fb_list);
1902 	}
1903 
1904 	FREE_LOCK(&lk);
1905 	/*
1906 	 * If the inode has never been written to disk (delay == 0),
1907 	 * then we can process the freeblks now that we have deleted
1908 	 * the dependencies.
1909 	 */
1910 	if (!delay)
1911 		handle_workitem_freeblocks(freeblks);
1912 }
1913 
1914 static int
1915 softdep_setup_freeblocks_bp(struct buf *bp, void *data)
1916 {
1917 	struct softdep_setup_freeblocks_info *info = data;
1918 	struct inodedep *inodedep;
1919 
1920 	if (getdirtybuf(&bp, MNT_WAIT) == 0) {
1921 		kprintf("softdep_setup_freeblocks_bp(1): caught bp %p going away\n", bp);
1922 		return(-1);
1923 	}
1924 	if (bp->b_vp != ITOV(info->ip) || (bp->b_flags & B_DELWRI) == 0) {
1925 		kprintf("softdep_setup_freeblocks_bp(2): caught bp %p going away\n", bp);
1926 		BUF_UNLOCK(bp);
1927 		return(-1);
1928 	}
1929 	(void) inodedep_lookup(info->fs, info->ip->i_number, 0, &inodedep);
1930 	deallocate_dependencies(bp, inodedep);
1931 	bp->b_flags |= B_INVAL | B_NOCACHE;
1932 	FREE_LOCK(&lk);
1933 	brelse(bp);
1934 	ACQUIRE_LOCK(&lk);
1935 	return(1);
1936 }
1937 
1938 /*
1939  * Reclaim any dependency structures from a buffer that is about to
1940  * be reallocated to a new vnode. The buffer must be locked, thus,
1941  * no I/O completion operations can occur while we are manipulating
1942  * its associated dependencies. The mutex is held so that other I/O's
1943  * associated with related dependencies do not occur.
1944  */
1945 static void
1946 deallocate_dependencies(struct buf *bp, struct inodedep *inodedep)
1947 {
1948 	struct worklist *wk;
1949 	struct indirdep *indirdep;
1950 	struct allocindir *aip;
1951 	struct pagedep *pagedep;
1952 	struct dirrem *dirrem;
1953 	struct diradd *dap;
1954 	int i;
1955 
1956 	while ((wk = LIST_FIRST(&bp->b_dep)) != NULL) {
1957 		switch (wk->wk_type) {
1958 
1959 		case D_INDIRDEP:
1960 			indirdep = WK_INDIRDEP(wk);
1961 			/*
1962 			 * None of the indirect pointers will ever be visible,
1963 			 * so they can simply be tossed. GOINGAWAY ensures
1964 			 * that allocated pointers will be saved in the buffer
1965 			 * cache until they are freed. Note that they will
1966 			 * only be able to be found by their physical address
1967 			 * since the inode mapping the logical address will
1968 			 * be gone. The save buffer used for the safe copy
1969 			 * was allocated in setup_allocindir_phase2 using
1970 			 * the physical address so it could be used for this
1971 			 * purpose. Hence we swap the safe copy with the real
1972 			 * copy, allowing the safe copy to be freed and holding
1973 			 * on to the real copy for later use in indir_trunc.
1974 			 *
1975 			 * NOTE: ir_savebp is relative to the block device
1976 			 * so b_bio1 contains the device block number.
1977 			 */
1978 			if (indirdep->ir_state & GOINGAWAY) {
1979 				FREE_LOCK(&lk);
1980 				panic("deallocate_dependencies: already gone");
1981 			}
1982 			indirdep->ir_state |= GOINGAWAY;
1983 			while ((aip = LIST_FIRST(&indirdep->ir_deplisthd)) != 0)
1984 				free_allocindir(aip, inodedep);
1985 			if (bp->b_bio1.bio_offset >= 0 ||
1986 			    bp->b_bio2.bio_offset != indirdep->ir_savebp->b_bio1.bio_offset) {
1987 				FREE_LOCK(&lk);
1988 				panic("deallocate_dependencies: not indir");
1989 			}
1990 			bcopy(bp->b_data, indirdep->ir_savebp->b_data,
1991 			    bp->b_bcount);
1992 			WORKLIST_REMOVE(wk);
1993 			WORKLIST_INSERT(&indirdep->ir_savebp->b_dep, wk);
1994 			continue;
1995 
1996 		case D_PAGEDEP:
1997 			pagedep = WK_PAGEDEP(wk);
1998 			/*
1999 			 * None of the directory additions will ever be
2000 			 * visible, so they can simply be tossed.
2001 			 */
2002 			for (i = 0; i < DAHASHSZ; i++)
2003 				while ((dap =
2004 				    LIST_FIRST(&pagedep->pd_diraddhd[i])))
2005 					free_diradd(dap);
2006 			while ((dap = LIST_FIRST(&pagedep->pd_pendinghd)) != 0)
2007 				free_diradd(dap);
2008 			/*
2009 			 * Copy any directory remove dependencies to the list
2010 			 * to be processed after the zero'ed inode is written.
2011 			 * If the inode has already been written, then they
2012 			 * can be dumped directly onto the work list.
2013 			 */
2014 			LIST_FOREACH(dirrem, &pagedep->pd_dirremhd, dm_next) {
2015 				LIST_REMOVE(dirrem, dm_next);
2016 				dirrem->dm_dirinum = pagedep->pd_ino;
2017 				if (inodedep == NULL ||
2018 				    (inodedep->id_state & ALLCOMPLETE) ==
2019 				     ALLCOMPLETE)
2020 					add_to_worklist(&dirrem->dm_list);
2021 				else
2022 					WORKLIST_INSERT(&inodedep->id_bufwait,
2023 					    &dirrem->dm_list);
2024 			}
2025 			WORKLIST_REMOVE(&pagedep->pd_list);
2026 			LIST_REMOVE(pagedep, pd_hash);
2027 			WORKITEM_FREE(pagedep, D_PAGEDEP);
2028 			continue;
2029 
2030 		case D_ALLOCINDIR:
2031 			free_allocindir(WK_ALLOCINDIR(wk), inodedep);
2032 			continue;
2033 
2034 		case D_ALLOCDIRECT:
2035 		case D_INODEDEP:
2036 			FREE_LOCK(&lk);
2037 			panic("deallocate_dependencies: Unexpected type %s",
2038 			    TYPENAME(wk->wk_type));
2039 			/* NOTREACHED */
2040 
2041 		default:
2042 			FREE_LOCK(&lk);
2043 			panic("deallocate_dependencies: Unknown type %s",
2044 			    TYPENAME(wk->wk_type));
2045 			/* NOTREACHED */
2046 		}
2047 	}
2048 }
2049 
2050 /*
2051  * Free an allocdirect. Generate a new freefrag work request if appropriate.
2052  * This routine must be called with splbio interrupts blocked.
2053  */
2054 static void
2055 free_allocdirect(struct allocdirectlst *adphead,
2056 		 struct allocdirect *adp, int delay)
2057 {
2058 
2059 #ifdef DEBUG
2060 	if (lk.lkt_held == NOHOLDER)
2061 		panic("free_allocdirect: lock not held");
2062 #endif
2063 	if ((adp->ad_state & DEPCOMPLETE) == 0)
2064 		LIST_REMOVE(adp, ad_deps);
2065 	TAILQ_REMOVE(adphead, adp, ad_next);
2066 	if ((adp->ad_state & COMPLETE) == 0)
2067 		WORKLIST_REMOVE(&adp->ad_list);
2068 	if (adp->ad_freefrag != NULL) {
2069 		if (delay)
2070 			WORKLIST_INSERT(&adp->ad_inodedep->id_bufwait,
2071 			    &adp->ad_freefrag->ff_list);
2072 		else
2073 			add_to_worklist(&adp->ad_freefrag->ff_list);
2074 	}
2075 	WORKITEM_FREE(adp, D_ALLOCDIRECT);
2076 }
2077 
2078 /*
2079  * Prepare an inode to be freed. The actual free operation is not
2080  * done until the zero'ed inode has been written to disk.
2081  */
2082 void
2083 softdep_freefile(struct vnode *pvp, ino_t ino, int mode)
2084 {
2085 	struct inode *ip = VTOI(pvp);
2086 	struct inodedep *inodedep;
2087 	struct freefile *freefile;
2088 
2089 	/*
2090 	 * This sets up the inode de-allocation dependency.
2091 	 */
2092 	MALLOC(freefile, struct freefile *, sizeof(struct freefile),
2093 		M_FREEFILE, M_SOFTDEP_FLAGS);
2094 	freefile->fx_list.wk_type = D_FREEFILE;
2095 	freefile->fx_list.wk_state = 0;
2096 	freefile->fx_mode = mode;
2097 	freefile->fx_oldinum = ino;
2098 	freefile->fx_devvp = ip->i_devvp;
2099 	freefile->fx_fs = ip->i_fs;
2100 
2101 	/*
2102 	 * If the inodedep does not exist, then the zero'ed inode has
2103 	 * been written to disk. If the allocated inode has never been
2104 	 * written to disk, then the on-disk inode is zero'ed. In either
2105 	 * case we can free the file immediately.
2106 	 */
2107 	ACQUIRE_LOCK(&lk);
2108 	if (inodedep_lookup(ip->i_fs, ino, 0, &inodedep) == 0 ||
2109 	    check_inode_unwritten(inodedep)) {
2110 		FREE_LOCK(&lk);
2111 		handle_workitem_freefile(freefile);
2112 		return;
2113 	}
2114 	WORKLIST_INSERT(&inodedep->id_inowait, &freefile->fx_list);
2115 	FREE_LOCK(&lk);
2116 }
2117 
2118 /*
2119  * Check to see if an inode has never been written to disk. If
2120  * so free the inodedep and return success, otherwise return failure.
2121  * This routine must be called with splbio interrupts blocked.
2122  *
2123  * If we still have a bitmap dependency, then the inode has never
2124  * been written to disk. Drop the dependency as it is no longer
2125  * necessary since the inode is being deallocated. We set the
2126  * ALLCOMPLETE flags since the bitmap now properly shows that the
2127  * inode is not allocated. Even if the inode is actively being
2128  * written, it has been rolled back to its zero'ed state, so we
2129  * are ensured that a zero inode is what is on the disk. For short
2130  * lived files, this change will usually result in removing all the
2131  * dependencies from the inode so that it can be freed immediately.
2132  */
2133 static int
2134 check_inode_unwritten(struct inodedep *inodedep)
2135 {
2136 
2137 	if ((inodedep->id_state & DEPCOMPLETE) != 0 ||
2138 	    LIST_FIRST(&inodedep->id_pendinghd) != NULL ||
2139 	    LIST_FIRST(&inodedep->id_bufwait) != NULL ||
2140 	    LIST_FIRST(&inodedep->id_inowait) != NULL ||
2141 	    TAILQ_FIRST(&inodedep->id_inoupdt) != NULL ||
2142 	    TAILQ_FIRST(&inodedep->id_newinoupdt) != NULL ||
2143 	    inodedep->id_nlinkdelta != 0)
2144 		return (0);
2145 
2146 	/*
2147 	 * Another process might be in initiate_write_inodeblock
2148 	 * trying to allocate memory without holding "Softdep Lock".
2149 	 */
2150 	if ((inodedep->id_state & IOSTARTED) != 0 &&
2151 	    inodedep->id_savedino == NULL)
2152 		return(0);
2153 
2154 	inodedep->id_state |= ALLCOMPLETE;
2155 	LIST_REMOVE(inodedep, id_deps);
2156 	inodedep->id_buf = NULL;
2157 	if (inodedep->id_state & ONWORKLIST)
2158 		WORKLIST_REMOVE(&inodedep->id_list);
2159 	if (inodedep->id_savedino != NULL) {
2160 		FREE(inodedep->id_savedino, M_INODEDEP);
2161 		inodedep->id_savedino = NULL;
2162 	}
2163 	if (free_inodedep(inodedep) == 0) {
2164 		FREE_LOCK(&lk);
2165 		panic("check_inode_unwritten: busy inode");
2166 	}
2167 	return (1);
2168 }
2169 
2170 /*
2171  * Try to free an inodedep structure. Return 1 if it could be freed.
2172  */
2173 static int
2174 free_inodedep(struct inodedep *inodedep)
2175 {
2176 
2177 	if ((inodedep->id_state & ONWORKLIST) != 0 ||
2178 	    (inodedep->id_state & ALLCOMPLETE) != ALLCOMPLETE ||
2179 	    LIST_FIRST(&inodedep->id_pendinghd) != NULL ||
2180 	    LIST_FIRST(&inodedep->id_bufwait) != NULL ||
2181 	    LIST_FIRST(&inodedep->id_inowait) != NULL ||
2182 	    TAILQ_FIRST(&inodedep->id_inoupdt) != NULL ||
2183 	    TAILQ_FIRST(&inodedep->id_newinoupdt) != NULL ||
2184 	    inodedep->id_nlinkdelta != 0 || inodedep->id_savedino != NULL)
2185 		return (0);
2186 	LIST_REMOVE(inodedep, id_hash);
2187 	WORKITEM_FREE(inodedep, D_INODEDEP);
2188 	num_inodedep -= 1;
2189 	return (1);
2190 }
2191 
2192 /*
2193  * This workitem routine performs the block de-allocation.
2194  * The workitem is added to the pending list after the updated
2195  * inode block has been written to disk.  As mentioned above,
2196  * checks regarding the number of blocks de-allocated (compared
2197  * to the number of blocks allocated for the file) are also
2198  * performed in this function.
2199  */
2200 static void
2201 handle_workitem_freeblocks(struct freeblks *freeblks)
2202 {
2203 	struct inode tip;
2204 	ufs_daddr_t bn;
2205 	struct fs *fs;
2206 	int i, level, bsize;
2207 	long nblocks, blocksreleased = 0;
2208 	int error, allerror = 0;
2209 	ufs_lbn_t baselbns[NIADDR], tmpval;
2210 
2211 	tip.i_number = freeblks->fb_previousinum;
2212 	tip.i_devvp = freeblks->fb_devvp;
2213 	tip.i_dev = freeblks->fb_devvp->v_rdev;
2214 	tip.i_fs = freeblks->fb_fs;
2215 	tip.i_size = freeblks->fb_oldsize;
2216 	tip.i_uid = freeblks->fb_uid;
2217 	fs = freeblks->fb_fs;
2218 	tmpval = 1;
2219 	baselbns[0] = NDADDR;
2220 	for (i = 1; i < NIADDR; i++) {
2221 		tmpval *= NINDIR(fs);
2222 		baselbns[i] = baselbns[i - 1] + tmpval;
2223 	}
2224 	nblocks = btodb(fs->fs_bsize);
2225 	blocksreleased = 0;
2226 	/*
2227 	 * Indirect blocks first.
2228 	 */
2229 	for (level = (NIADDR - 1); level >= 0; level--) {
2230 		if ((bn = freeblks->fb_iblks[level]) == 0)
2231 			continue;
2232 		if ((error = indir_trunc(&tip, fsbtodoff(fs, bn), level,
2233 		    baselbns[level], &blocksreleased)) == 0)
2234 			allerror = error;
2235 		ffs_blkfree(&tip, bn, fs->fs_bsize);
2236 		blocksreleased += nblocks;
2237 	}
2238 	/*
2239 	 * All direct blocks or frags.
2240 	 */
2241 	for (i = (NDADDR - 1); i >= 0; i--) {
2242 		if ((bn = freeblks->fb_dblks[i]) == 0)
2243 			continue;
2244 		bsize = blksize(fs, &tip, i);
2245 		ffs_blkfree(&tip, bn, bsize);
2246 		blocksreleased += btodb(bsize);
2247 	}
2248 
2249 #ifdef DIAGNOSTIC
2250 	if (freeblks->fb_chkcnt != blocksreleased)
2251 		kprintf("handle_workitem_freeblocks: block count\n");
2252 	if (allerror)
2253 		softdep_error("handle_workitem_freeblks", allerror);
2254 #endif /* DIAGNOSTIC */
2255 	WORKITEM_FREE(freeblks, D_FREEBLKS);
2256 }
2257 
2258 /*
2259  * Release blocks associated with the inode ip and stored in the indirect
2260  * block at doffset. If level is greater than SINGLE, the block is an
2261  * indirect block and recursive calls to indirtrunc must be used to
2262  * cleanse other indirect blocks.
2263  */
2264 static int
2265 indir_trunc(struct inode *ip, off_t doffset, int level, ufs_lbn_t lbn,
2266 	    long *countp)
2267 {
2268 	struct buf *bp;
2269 	ufs_daddr_t *bap;
2270 	ufs_daddr_t nb;
2271 	struct fs *fs;
2272 	struct worklist *wk;
2273 	struct indirdep *indirdep;
2274 	int i, lbnadd, nblocks;
2275 	int error, allerror = 0;
2276 
2277 	fs = ip->i_fs;
2278 	lbnadd = 1;
2279 	for (i = level; i > 0; i--)
2280 		lbnadd *= NINDIR(fs);
2281 	/*
2282 	 * Get buffer of block pointers to be freed. This routine is not
2283 	 * called until the zero'ed inode has been written, so it is safe
2284 	 * to free blocks as they are encountered. Because the inode has
2285 	 * been zero'ed, calls to bmap on these blocks will fail. So, we
2286 	 * have to use the on-disk address and the block device for the
2287 	 * filesystem to look them up. If the file was deleted before its
2288 	 * indirect blocks were all written to disk, the routine that set
2289 	 * us up (deallocate_dependencies) will have arranged to leave
2290 	 * a complete copy of the indirect block in memory for our use.
2291 	 * Otherwise we have to read the blocks in from the disk.
2292 	 */
2293 	ACQUIRE_LOCK(&lk);
2294 	if ((bp = findblk(ip->i_devvp, doffset)) != NULL &&
2295 	    (wk = LIST_FIRST(&bp->b_dep)) != NULL) {
2296 		/*
2297 		 * bp must be ir_savebp, which is held locked for our use.
2298 		 */
2299 		if (wk->wk_type != D_INDIRDEP ||
2300 		    (indirdep = WK_INDIRDEP(wk))->ir_savebp != bp ||
2301 		    (indirdep->ir_state & GOINGAWAY) == 0) {
2302 			FREE_LOCK(&lk);
2303 			panic("indir_trunc: lost indirdep");
2304 		}
2305 		WORKLIST_REMOVE(wk);
2306 		WORKITEM_FREE(indirdep, D_INDIRDEP);
2307 		if (LIST_FIRST(&bp->b_dep) != NULL) {
2308 			FREE_LOCK(&lk);
2309 			panic("indir_trunc: dangling dep");
2310 		}
2311 		FREE_LOCK(&lk);
2312 	} else {
2313 		FREE_LOCK(&lk);
2314 		error = bread(ip->i_devvp, doffset, (int)fs->fs_bsize, &bp);
2315 		if (error)
2316 			return (error);
2317 	}
2318 	/*
2319 	 * Recursively free indirect blocks.
2320 	 */
2321 	bap = (ufs_daddr_t *)bp->b_data;
2322 	nblocks = btodb(fs->fs_bsize);
2323 	for (i = NINDIR(fs) - 1; i >= 0; i--) {
2324 		if ((nb = bap[i]) == 0)
2325 			continue;
2326 		if (level != 0) {
2327 			if ((error = indir_trunc(ip, fsbtodoff(fs, nb),
2328 			     level - 1, lbn + (i * lbnadd), countp)) != 0)
2329 				allerror = error;
2330 		}
2331 		ffs_blkfree(ip, nb, fs->fs_bsize);
2332 		*countp += nblocks;
2333 	}
2334 	bp->b_flags |= B_INVAL | B_NOCACHE;
2335 	brelse(bp);
2336 	return (allerror);
2337 }
2338 
2339 /*
2340  * Free an allocindir.
2341  * This routine must be called with splbio interrupts blocked.
2342  */
2343 static void
2344 free_allocindir(struct allocindir *aip, struct inodedep *inodedep)
2345 {
2346 	struct freefrag *freefrag;
2347 
2348 #ifdef DEBUG
2349 	if (lk.lkt_held == NOHOLDER)
2350 		panic("free_allocindir: lock not held");
2351 #endif
2352 	if ((aip->ai_state & DEPCOMPLETE) == 0)
2353 		LIST_REMOVE(aip, ai_deps);
2354 	if (aip->ai_state & ONWORKLIST)
2355 		WORKLIST_REMOVE(&aip->ai_list);
2356 	LIST_REMOVE(aip, ai_next);
2357 	if ((freefrag = aip->ai_freefrag) != NULL) {
2358 		if (inodedep == NULL)
2359 			add_to_worklist(&freefrag->ff_list);
2360 		else
2361 			WORKLIST_INSERT(&inodedep->id_bufwait,
2362 			    &freefrag->ff_list);
2363 	}
2364 	WORKITEM_FREE(aip, D_ALLOCINDIR);
2365 }
2366 
2367 /*
2368  * Directory entry addition dependencies.
2369  *
2370  * When adding a new directory entry, the inode (with its incremented link
2371  * count) must be written to disk before the directory entry's pointer to it.
2372  * Also, if the inode is newly allocated, the corresponding freemap must be
2373  * updated (on disk) before the directory entry's pointer. These requirements
2374  * are met via undo/redo on the directory entry's pointer, which consists
2375  * simply of the inode number.
2376  *
2377  * As directory entries are added and deleted, the free space within a
2378  * directory block can become fragmented.  The ufs filesystem will compact
2379  * a fragmented directory block to make space for a new entry. When this
2380  * occurs, the offsets of previously added entries change. Any "diradd"
2381  * dependency structures corresponding to these entries must be updated with
2382  * the new offsets.
2383  */
2384 
2385 /*
2386  * This routine is called after the in-memory inode's link
2387  * count has been incremented, but before the directory entry's
2388  * pointer to the inode has been set.
2389  *
2390  * Parameters:
2391  *	bp:		buffer containing directory block
2392  *	dp:		inode for directory
2393  *	diroffset:	offset of new entry in directory
2394  *	newinum:	inode referenced by new directory entry
2395  *	newdirbp:	non-NULL => contents of new mkdir
2396  */
2397 void
2398 softdep_setup_directory_add(struct buf *bp, struct inode *dp, off_t diroffset,
2399 			    ino_t newinum, struct buf *newdirbp)
2400 {
2401 	int offset;		/* offset of new entry within directory block */
2402 	ufs_lbn_t lbn;		/* block in directory containing new entry */
2403 	struct fs *fs;
2404 	struct diradd *dap;
2405 	struct pagedep *pagedep;
2406 	struct inodedep *inodedep;
2407 	struct mkdir *mkdir1, *mkdir2;
2408 
2409 	/*
2410 	 * Whiteouts have no dependencies.
2411 	 */
2412 	if (newinum == WINO) {
2413 		if (newdirbp != NULL)
2414 			bdwrite(newdirbp);
2415 		return;
2416 	}
2417 
2418 	fs = dp->i_fs;
2419 	lbn = lblkno(fs, diroffset);
2420 	offset = blkoff(fs, diroffset);
2421 	MALLOC(dap, struct diradd *, sizeof(struct diradd), M_DIRADD,
2422 	    M_SOFTDEP_FLAGS);
2423 	bzero(dap, sizeof(struct diradd));
2424 	dap->da_list.wk_type = D_DIRADD;
2425 	dap->da_offset = offset;
2426 	dap->da_newinum = newinum;
2427 	dap->da_state = ATTACHED;
2428 	if (newdirbp == NULL) {
2429 		dap->da_state |= DEPCOMPLETE;
2430 		ACQUIRE_LOCK(&lk);
2431 	} else {
2432 		dap->da_state |= MKDIR_BODY | MKDIR_PARENT;
2433 		MALLOC(mkdir1, struct mkdir *, sizeof(struct mkdir), M_MKDIR,
2434 		    M_SOFTDEP_FLAGS);
2435 		mkdir1->md_list.wk_type = D_MKDIR;
2436 		mkdir1->md_state = MKDIR_BODY;
2437 		mkdir1->md_diradd = dap;
2438 		MALLOC(mkdir2, struct mkdir *, sizeof(struct mkdir), M_MKDIR,
2439 		    M_SOFTDEP_FLAGS);
2440 		mkdir2->md_list.wk_type = D_MKDIR;
2441 		mkdir2->md_state = MKDIR_PARENT;
2442 		mkdir2->md_diradd = dap;
2443 		/*
2444 		 * Dependency on "." and ".." being written to disk.
2445 		 */
2446 		mkdir1->md_buf = newdirbp;
2447 		ACQUIRE_LOCK(&lk);
2448 		LIST_INSERT_HEAD(&mkdirlisthd, mkdir1, md_mkdirs);
2449 		WORKLIST_INSERT(&newdirbp->b_dep, &mkdir1->md_list);
2450 		FREE_LOCK(&lk);
2451 		bdwrite(newdirbp);
2452 		/*
2453 		 * Dependency on link count increase for parent directory
2454 		 */
2455 		ACQUIRE_LOCK(&lk);
2456 		if (inodedep_lookup(dp->i_fs, dp->i_number, 0, &inodedep) == 0
2457 		    || (inodedep->id_state & ALLCOMPLETE) == ALLCOMPLETE) {
2458 			dap->da_state &= ~MKDIR_PARENT;
2459 			WORKITEM_FREE(mkdir2, D_MKDIR);
2460 		} else {
2461 			LIST_INSERT_HEAD(&mkdirlisthd, mkdir2, md_mkdirs);
2462 			WORKLIST_INSERT(&inodedep->id_bufwait,&mkdir2->md_list);
2463 		}
2464 	}
2465 	/*
2466 	 * Link into parent directory pagedep to await its being written.
2467 	 */
2468 	if (pagedep_lookup(dp, lbn, DEPALLOC, &pagedep) == 0)
2469 		WORKLIST_INSERT(&bp->b_dep, &pagedep->pd_list);
2470 	dap->da_pagedep = pagedep;
2471 	LIST_INSERT_HEAD(&pagedep->pd_diraddhd[DIRADDHASH(offset)], dap,
2472 	    da_pdlist);
2473 	/*
2474 	 * Link into its inodedep. Put it on the id_bufwait list if the inode
2475 	 * is not yet written. If it is written, do the post-inode write
2476 	 * processing to put it on the id_pendinghd list.
2477 	 */
2478 	(void) inodedep_lookup(fs, newinum, DEPALLOC, &inodedep);
2479 	if ((inodedep->id_state & ALLCOMPLETE) == ALLCOMPLETE)
2480 		diradd_inode_written(dap, inodedep);
2481 	else
2482 		WORKLIST_INSERT(&inodedep->id_bufwait, &dap->da_list);
2483 	FREE_LOCK(&lk);
2484 }
2485 
2486 /*
2487  * This procedure is called to change the offset of a directory
2488  * entry when compacting a directory block which must be owned
2489  * exclusively by the caller. Note that the actual entry movement
2490  * must be done in this procedure to ensure that no I/O completions
2491  * occur while the move is in progress.
2492  *
2493  * Parameters:
2494  *	dp:	inode for directory
2495  *	base:		address of dp->i_offset
2496  *	oldloc:		address of old directory location
2497  *	newloc:		address of new directory location
2498  *	entrysize:	size of directory entry
2499  */
2500 void
2501 softdep_change_directoryentry_offset(struct inode *dp, caddr_t base,
2502 				     caddr_t oldloc, caddr_t newloc,
2503 				     int entrysize)
2504 {
2505 	int offset, oldoffset, newoffset;
2506 	struct pagedep *pagedep;
2507 	struct diradd *dap;
2508 	ufs_lbn_t lbn;
2509 
2510 	ACQUIRE_LOCK(&lk);
2511 	lbn = lblkno(dp->i_fs, dp->i_offset);
2512 	offset = blkoff(dp->i_fs, dp->i_offset);
2513 	if (pagedep_lookup(dp, lbn, 0, &pagedep) == 0)
2514 		goto done;
2515 	oldoffset = offset + (oldloc - base);
2516 	newoffset = offset + (newloc - base);
2517 
2518 	LIST_FOREACH(dap, &pagedep->pd_diraddhd[DIRADDHASH(oldoffset)], da_pdlist) {
2519 		if (dap->da_offset != oldoffset)
2520 			continue;
2521 		dap->da_offset = newoffset;
2522 		if (DIRADDHASH(newoffset) == DIRADDHASH(oldoffset))
2523 			break;
2524 		LIST_REMOVE(dap, da_pdlist);
2525 		LIST_INSERT_HEAD(&pagedep->pd_diraddhd[DIRADDHASH(newoffset)],
2526 		    dap, da_pdlist);
2527 		break;
2528 	}
2529 	if (dap == NULL) {
2530 
2531 		LIST_FOREACH(dap, &pagedep->pd_pendinghd, da_pdlist) {
2532 			if (dap->da_offset == oldoffset) {
2533 				dap->da_offset = newoffset;
2534 				break;
2535 			}
2536 		}
2537 	}
2538 done:
2539 	bcopy(oldloc, newloc, entrysize);
2540 	FREE_LOCK(&lk);
2541 }
2542 
2543 /*
2544  * Free a diradd dependency structure. This routine must be called
2545  * with splbio interrupts blocked.
2546  */
2547 static void
2548 free_diradd(struct diradd *dap)
2549 {
2550 	struct dirrem *dirrem;
2551 	struct pagedep *pagedep;
2552 	struct inodedep *inodedep;
2553 	struct mkdir *mkdir, *nextmd;
2554 
2555 #ifdef DEBUG
2556 	if (lk.lkt_held == NOHOLDER)
2557 		panic("free_diradd: lock not held");
2558 #endif
2559 	WORKLIST_REMOVE(&dap->da_list);
2560 	LIST_REMOVE(dap, da_pdlist);
2561 	if ((dap->da_state & DIRCHG) == 0) {
2562 		pagedep = dap->da_pagedep;
2563 	} else {
2564 		dirrem = dap->da_previous;
2565 		pagedep = dirrem->dm_pagedep;
2566 		dirrem->dm_dirinum = pagedep->pd_ino;
2567 		add_to_worklist(&dirrem->dm_list);
2568 	}
2569 	if (inodedep_lookup(VFSTOUFS(pagedep->pd_mnt)->um_fs, dap->da_newinum,
2570 	    0, &inodedep) != 0)
2571 		(void) free_inodedep(inodedep);
2572 	if ((dap->da_state & (MKDIR_PARENT | MKDIR_BODY)) != 0) {
2573 		for (mkdir = LIST_FIRST(&mkdirlisthd); mkdir; mkdir = nextmd) {
2574 			nextmd = LIST_NEXT(mkdir, md_mkdirs);
2575 			if (mkdir->md_diradd != dap)
2576 				continue;
2577 			dap->da_state &= ~mkdir->md_state;
2578 			WORKLIST_REMOVE(&mkdir->md_list);
2579 			LIST_REMOVE(mkdir, md_mkdirs);
2580 			WORKITEM_FREE(mkdir, D_MKDIR);
2581 		}
2582 		if ((dap->da_state & (MKDIR_PARENT | MKDIR_BODY)) != 0) {
2583 			FREE_LOCK(&lk);
2584 			panic("free_diradd: unfound ref");
2585 		}
2586 	}
2587 	WORKITEM_FREE(dap, D_DIRADD);
2588 }
2589 
2590 /*
2591  * Directory entry removal dependencies.
2592  *
2593  * When removing a directory entry, the entry's inode pointer must be
2594  * zero'ed on disk before the corresponding inode's link count is decremented
2595  * (possibly freeing the inode for re-use). This dependency is handled by
2596  * updating the directory entry but delaying the inode count reduction until
2597  * after the directory block has been written to disk. After this point, the
2598  * inode count can be decremented whenever it is convenient.
2599  */
2600 
2601 /*
2602  * This routine should be called immediately after removing
2603  * a directory entry.  The inode's link count should not be
2604  * decremented by the calling procedure -- the soft updates
2605  * code will do this task when it is safe.
2606  *
2607  * Parameters:
2608  *	bp:		buffer containing directory block
2609  *	dp:		inode for the directory being modified
2610  *	ip:		inode for directory entry being removed
2611  *	isrmdir:	indicates if doing RMDIR
2612  */
2613 void
2614 softdep_setup_remove(struct buf *bp, struct inode *dp, struct inode *ip,
2615 		     int isrmdir)
2616 {
2617 	struct dirrem *dirrem, *prevdirrem;
2618 
2619 	/*
2620 	 * Allocate a new dirrem if appropriate and ACQUIRE_LOCK.
2621 	 */
2622 	dirrem = newdirrem(bp, dp, ip, isrmdir, &prevdirrem);
2623 
2624 	/*
2625 	 * If the COMPLETE flag is clear, then there were no active
2626 	 * entries and we want to roll back to a zeroed entry until
2627 	 * the new inode is committed to disk. If the COMPLETE flag is
2628 	 * set then we have deleted an entry that never made it to
2629 	 * disk. If the entry we deleted resulted from a name change,
2630 	 * then the old name still resides on disk. We cannot delete
2631 	 * its inode (returned to us in prevdirrem) until the zeroed
2632 	 * directory entry gets to disk. The new inode has never been
2633 	 * referenced on the disk, so can be deleted immediately.
2634 	 */
2635 	if ((dirrem->dm_state & COMPLETE) == 0) {
2636 		LIST_INSERT_HEAD(&dirrem->dm_pagedep->pd_dirremhd, dirrem,
2637 		    dm_next);
2638 		FREE_LOCK(&lk);
2639 	} else {
2640 		if (prevdirrem != NULL)
2641 			LIST_INSERT_HEAD(&dirrem->dm_pagedep->pd_dirremhd,
2642 			    prevdirrem, dm_next);
2643 		dirrem->dm_dirinum = dirrem->dm_pagedep->pd_ino;
2644 		FREE_LOCK(&lk);
2645 		handle_workitem_remove(dirrem);
2646 	}
2647 }
2648 
2649 /*
2650  * Allocate a new dirrem if appropriate and return it along with
2651  * its associated pagedep. Called without a lock, returns with lock.
2652  */
2653 static long num_dirrem;		/* number of dirrem allocated */
2654 
2655 /*
2656  * Parameters:
2657  *	bp:		buffer containing directory block
2658  *	dp:		inode for the directory being modified
2659  *	ip:		inode for directory entry being removed
2660  *	isrmdir:	indicates if doing RMDIR
2661  *	prevdirremp:	previously referenced inode, if any
2662  */
2663 static struct dirrem *
2664 newdirrem(struct buf *bp, struct inode *dp, struct inode *ip,
2665 	  int isrmdir, struct dirrem **prevdirremp)
2666 {
2667 	int offset;
2668 	ufs_lbn_t lbn;
2669 	struct diradd *dap;
2670 	struct dirrem *dirrem;
2671 	struct pagedep *pagedep;
2672 
2673 	/*
2674 	 * Whiteouts have no deletion dependencies.
2675 	 */
2676 	if (ip == NULL)
2677 		panic("newdirrem: whiteout");
2678 	/*
2679 	 * If we are over our limit, try to improve the situation.
2680 	 * Limiting the number of dirrem structures will also limit
2681 	 * the number of freefile and freeblks structures.
2682 	 */
2683 	if (num_dirrem > max_softdeps / 2 && speedup_syncer() == 0)
2684 		(void) request_cleanup(FLUSH_REMOVE, 0);
2685 	num_dirrem += 1;
2686 	MALLOC(dirrem, struct dirrem *, sizeof(struct dirrem),
2687 		M_DIRREM, M_SOFTDEP_FLAGS);
2688 	bzero(dirrem, sizeof(struct dirrem));
2689 	dirrem->dm_list.wk_type = D_DIRREM;
2690 	dirrem->dm_state = isrmdir ? RMDIR : 0;
2691 	dirrem->dm_mnt = ITOV(ip)->v_mount;
2692 	dirrem->dm_oldinum = ip->i_number;
2693 	*prevdirremp = NULL;
2694 
2695 	ACQUIRE_LOCK(&lk);
2696 	lbn = lblkno(dp->i_fs, dp->i_offset);
2697 	offset = blkoff(dp->i_fs, dp->i_offset);
2698 	if (pagedep_lookup(dp, lbn, DEPALLOC, &pagedep) == 0)
2699 		WORKLIST_INSERT(&bp->b_dep, &pagedep->pd_list);
2700 	dirrem->dm_pagedep = pagedep;
2701 	/*
2702 	 * Check for a diradd dependency for the same directory entry.
2703 	 * If present, then both dependencies become obsolete and can
2704 	 * be de-allocated. Check for an entry on both the pd_dirraddhd
2705 	 * list and the pd_pendinghd list.
2706 	 */
2707 
2708 	LIST_FOREACH(dap, &pagedep->pd_diraddhd[DIRADDHASH(offset)], da_pdlist)
2709 		if (dap->da_offset == offset)
2710 			break;
2711 	if (dap == NULL) {
2712 
2713 		LIST_FOREACH(dap, &pagedep->pd_pendinghd, da_pdlist)
2714 			if (dap->da_offset == offset)
2715 				break;
2716 		if (dap == NULL)
2717 			return (dirrem);
2718 	}
2719 	/*
2720 	 * Must be ATTACHED at this point.
2721 	 */
2722 	if ((dap->da_state & ATTACHED) == 0) {
2723 		FREE_LOCK(&lk);
2724 		panic("newdirrem: not ATTACHED");
2725 	}
2726 	if (dap->da_newinum != ip->i_number) {
2727 		FREE_LOCK(&lk);
2728 		panic("newdirrem: inum %"PRId64" should be %"PRId64,
2729 		    ip->i_number, dap->da_newinum);
2730 	}
2731 	/*
2732 	 * If we are deleting a changed name that never made it to disk,
2733 	 * then return the dirrem describing the previous inode (which
2734 	 * represents the inode currently referenced from this entry on disk).
2735 	 */
2736 	if ((dap->da_state & DIRCHG) != 0) {
2737 		*prevdirremp = dap->da_previous;
2738 		dap->da_state &= ~DIRCHG;
2739 		dap->da_pagedep = pagedep;
2740 	}
2741 	/*
2742 	 * We are deleting an entry that never made it to disk.
2743 	 * Mark it COMPLETE so we can delete its inode immediately.
2744 	 */
2745 	dirrem->dm_state |= COMPLETE;
2746 	free_diradd(dap);
2747 	return (dirrem);
2748 }
2749 
2750 /*
2751  * Directory entry change dependencies.
2752  *
2753  * Changing an existing directory entry requires that an add operation
2754  * be completed first followed by a deletion. The semantics for the addition
2755  * are identical to the description of adding a new entry above except
2756  * that the rollback is to the old inode number rather than zero. Once
2757  * the addition dependency is completed, the removal is done as described
2758  * in the removal routine above.
2759  */
2760 
2761 /*
2762  * This routine should be called immediately after changing
2763  * a directory entry.  The inode's link count should not be
2764  * decremented by the calling procedure -- the soft updates
2765  * code will perform this task when it is safe.
2766  *
2767  * Parameters:
2768  *	bp:		buffer containing directory block
2769  *	dp:		inode for the directory being modified
2770  *	ip:		inode for directory entry being removed
2771  *	newinum:	new inode number for changed entry
2772  *	isrmdir:	indicates if doing RMDIR
2773  */
2774 void
2775 softdep_setup_directory_change(struct buf *bp, struct inode *dp,
2776 			       struct inode *ip, ino_t newinum,
2777 			       int isrmdir)
2778 {
2779 	int offset;
2780 	struct diradd *dap = NULL;
2781 	struct dirrem *dirrem, *prevdirrem;
2782 	struct pagedep *pagedep;
2783 	struct inodedep *inodedep;
2784 
2785 	offset = blkoff(dp->i_fs, dp->i_offset);
2786 
2787 	/*
2788 	 * Whiteouts do not need diradd dependencies.
2789 	 */
2790 	if (newinum != WINO) {
2791 		MALLOC(dap, struct diradd *, sizeof(struct diradd),
2792 		    M_DIRADD, M_SOFTDEP_FLAGS);
2793 		bzero(dap, sizeof(struct diradd));
2794 		dap->da_list.wk_type = D_DIRADD;
2795 		dap->da_state = DIRCHG | ATTACHED | DEPCOMPLETE;
2796 		dap->da_offset = offset;
2797 		dap->da_newinum = newinum;
2798 	}
2799 
2800 	/*
2801 	 * Allocate a new dirrem and ACQUIRE_LOCK.
2802 	 */
2803 	dirrem = newdirrem(bp, dp, ip, isrmdir, &prevdirrem);
2804 	pagedep = dirrem->dm_pagedep;
2805 	/*
2806 	 * The possible values for isrmdir:
2807 	 *	0 - non-directory file rename
2808 	 *	1 - directory rename within same directory
2809 	 *   inum - directory rename to new directory of given inode number
2810 	 * When renaming to a new directory, we are both deleting and
2811 	 * creating a new directory entry, so the link count on the new
2812 	 * directory should not change. Thus we do not need the followup
2813 	 * dirrem which is usually done in handle_workitem_remove. We set
2814 	 * the DIRCHG flag to tell handle_workitem_remove to skip the
2815 	 * followup dirrem.
2816 	 */
2817 	if (isrmdir > 1)
2818 		dirrem->dm_state |= DIRCHG;
2819 
2820 	/*
2821 	 * Whiteouts have no additional dependencies,
2822 	 * so just put the dirrem on the correct list.
2823 	 */
2824 	if (newinum == WINO) {
2825 		if ((dirrem->dm_state & COMPLETE) == 0) {
2826 			LIST_INSERT_HEAD(&pagedep->pd_dirremhd, dirrem,
2827 			    dm_next);
2828 		} else {
2829 			dirrem->dm_dirinum = pagedep->pd_ino;
2830 			add_to_worklist(&dirrem->dm_list);
2831 		}
2832 		FREE_LOCK(&lk);
2833 		return;
2834 	}
2835 
2836 	/*
2837 	 * If the COMPLETE flag is clear, then there were no active
2838 	 * entries and we want to roll back to the previous inode until
2839 	 * the new inode is committed to disk. If the COMPLETE flag is
2840 	 * set, then we have deleted an entry that never made it to disk.
2841 	 * If the entry we deleted resulted from a name change, then the old
2842 	 * inode reference still resides on disk. Any rollback that we do
2843 	 * needs to be to that old inode (returned to us in prevdirrem). If
2844 	 * the entry we deleted resulted from a create, then there is
2845 	 * no entry on the disk, so we want to roll back to zero rather
2846 	 * than the uncommitted inode. In either of the COMPLETE cases we
2847 	 * want to immediately free the unwritten and unreferenced inode.
2848 	 */
2849 	if ((dirrem->dm_state & COMPLETE) == 0) {
2850 		dap->da_previous = dirrem;
2851 	} else {
2852 		if (prevdirrem != NULL) {
2853 			dap->da_previous = prevdirrem;
2854 		} else {
2855 			dap->da_state &= ~DIRCHG;
2856 			dap->da_pagedep = pagedep;
2857 		}
2858 		dirrem->dm_dirinum = pagedep->pd_ino;
2859 		add_to_worklist(&dirrem->dm_list);
2860 	}
2861 	/*
2862 	 * Link into its inodedep. Put it on the id_bufwait list if the inode
2863 	 * is not yet written. If it is written, do the post-inode write
2864 	 * processing to put it on the id_pendinghd list.
2865 	 */
2866 	if (inodedep_lookup(dp->i_fs, newinum, DEPALLOC, &inodedep) == 0 ||
2867 	    (inodedep->id_state & ALLCOMPLETE) == ALLCOMPLETE) {
2868 		dap->da_state |= COMPLETE;
2869 		LIST_INSERT_HEAD(&pagedep->pd_pendinghd, dap, da_pdlist);
2870 		WORKLIST_INSERT(&inodedep->id_pendinghd, &dap->da_list);
2871 	} else {
2872 		LIST_INSERT_HEAD(&pagedep->pd_diraddhd[DIRADDHASH(offset)],
2873 		    dap, da_pdlist);
2874 		WORKLIST_INSERT(&inodedep->id_bufwait, &dap->da_list);
2875 	}
2876 	FREE_LOCK(&lk);
2877 }
2878 
2879 /*
2880  * Called whenever the link count on an inode is changed.
2881  * It creates an inode dependency so that the new reference(s)
2882  * to the inode cannot be committed to disk until the updated
2883  * inode has been written.
2884  *
2885  * Parameters:
2886  *	ip:	the inode with the increased link count
2887  */
2888 void
2889 softdep_change_linkcnt(struct inode *ip)
2890 {
2891 	struct inodedep *inodedep;
2892 
2893 	ACQUIRE_LOCK(&lk);
2894 	(void) inodedep_lookup(ip->i_fs, ip->i_number, DEPALLOC, &inodedep);
2895 	if (ip->i_nlink < ip->i_effnlink) {
2896 		FREE_LOCK(&lk);
2897 		panic("softdep_change_linkcnt: bad delta");
2898 	}
2899 	inodedep->id_nlinkdelta = ip->i_nlink - ip->i_effnlink;
2900 	FREE_LOCK(&lk);
2901 }
2902 
2903 /*
2904  * This workitem decrements the inode's link count.
2905  * If the link count reaches zero, the file is removed.
2906  */
2907 static void
2908 handle_workitem_remove(struct dirrem *dirrem)
2909 {
2910 	struct inodedep *inodedep;
2911 	struct vnode *vp;
2912 	struct inode *ip;
2913 	ino_t oldinum;
2914 	int error;
2915 
2916 	if ((error = VFS_VGET(dirrem->dm_mnt, dirrem->dm_oldinum, &vp)) != 0) {
2917 		softdep_error("handle_workitem_remove: vget", error);
2918 		return;
2919 	}
2920 	ip = VTOI(vp);
2921 	ACQUIRE_LOCK(&lk);
2922 	if ((inodedep_lookup(ip->i_fs, dirrem->dm_oldinum, 0, &inodedep)) == 0){
2923 		FREE_LOCK(&lk);
2924 		panic("handle_workitem_remove: lost inodedep");
2925 	}
2926 	/*
2927 	 * Normal file deletion.
2928 	 */
2929 	if ((dirrem->dm_state & RMDIR) == 0) {
2930 		ip->i_nlink--;
2931 		ip->i_flag |= IN_CHANGE;
2932 		if (ip->i_nlink < ip->i_effnlink) {
2933 			FREE_LOCK(&lk);
2934 			panic("handle_workitem_remove: bad file delta");
2935 		}
2936 		inodedep->id_nlinkdelta = ip->i_nlink - ip->i_effnlink;
2937 		FREE_LOCK(&lk);
2938 		vput(vp);
2939 		num_dirrem -= 1;
2940 		WORKITEM_FREE(dirrem, D_DIRREM);
2941 		return;
2942 	}
2943 	/*
2944 	 * Directory deletion. Decrement reference count for both the
2945 	 * just deleted parent directory entry and the reference for ".".
2946 	 * Next truncate the directory to length zero. When the
2947 	 * truncation completes, arrange to have the reference count on
2948 	 * the parent decremented to account for the loss of "..".
2949 	 */
2950 	ip->i_nlink -= 2;
2951 	ip->i_flag |= IN_CHANGE;
2952 	if (ip->i_nlink < ip->i_effnlink) {
2953 		FREE_LOCK(&lk);
2954 		panic("handle_workitem_remove: bad dir delta");
2955 	}
2956 	inodedep->id_nlinkdelta = ip->i_nlink - ip->i_effnlink;
2957 	FREE_LOCK(&lk);
2958 	if ((error = ffs_truncate(vp, (off_t)0, 0, proc0.p_ucred)) != 0)
2959 		softdep_error("handle_workitem_remove: truncate", error);
2960 	/*
2961 	 * Rename a directory to a new parent. Since, we are both deleting
2962 	 * and creating a new directory entry, the link count on the new
2963 	 * directory should not change. Thus we skip the followup dirrem.
2964 	 */
2965 	if (dirrem->dm_state & DIRCHG) {
2966 		vput(vp);
2967 		num_dirrem -= 1;
2968 		WORKITEM_FREE(dirrem, D_DIRREM);
2969 		return;
2970 	}
2971 	/*
2972 	 * If the inodedep does not exist, then the zero'ed inode has
2973 	 * been written to disk. If the allocated inode has never been
2974 	 * written to disk, then the on-disk inode is zero'ed. In either
2975 	 * case we can remove the file immediately.
2976 	 */
2977 	ACQUIRE_LOCK(&lk);
2978 	dirrem->dm_state = 0;
2979 	oldinum = dirrem->dm_oldinum;
2980 	dirrem->dm_oldinum = dirrem->dm_dirinum;
2981 	if (inodedep_lookup(ip->i_fs, oldinum, 0, &inodedep) == 0 ||
2982 	    check_inode_unwritten(inodedep)) {
2983 		FREE_LOCK(&lk);
2984 		vput(vp);
2985 		handle_workitem_remove(dirrem);
2986 		return;
2987 	}
2988 	WORKLIST_INSERT(&inodedep->id_inowait, &dirrem->dm_list);
2989 	FREE_LOCK(&lk);
2990 	ip->i_flag |= IN_CHANGE;
2991 	ffs_update(vp, 0);
2992 	vput(vp);
2993 }
2994 
2995 /*
2996  * Inode de-allocation dependencies.
2997  *
2998  * When an inode's link count is reduced to zero, it can be de-allocated. We
2999  * found it convenient to postpone de-allocation until after the inode is
3000  * written to disk with its new link count (zero).  At this point, all of the
3001  * on-disk inode's block pointers are nullified and, with careful dependency
3002  * list ordering, all dependencies related to the inode will be satisfied and
3003  * the corresponding dependency structures de-allocated.  So, if/when the
3004  * inode is reused, there will be no mixing of old dependencies with new
3005  * ones.  This artificial dependency is set up by the block de-allocation
3006  * procedure above (softdep_setup_freeblocks) and completed by the
3007  * following procedure.
3008  */
3009 static void
3010 handle_workitem_freefile(struct freefile *freefile)
3011 {
3012 	struct vnode vp;
3013 	struct inode tip;
3014 	struct inodedep *idp;
3015 	int error;
3016 
3017 #ifdef DEBUG
3018 	ACQUIRE_LOCK(&lk);
3019 	error = inodedep_lookup(freefile->fx_fs, freefile->fx_oldinum, 0, &idp);
3020 	FREE_LOCK(&lk);
3021 	if (error)
3022 		panic("handle_workitem_freefile: inodedep survived");
3023 #endif
3024 	tip.i_devvp = freefile->fx_devvp;
3025 	tip.i_dev = freefile->fx_devvp->v_rdev;
3026 	tip.i_fs = freefile->fx_fs;
3027 	vp.v_data = &tip;
3028 	if ((error = ffs_freefile(&vp, freefile->fx_oldinum, freefile->fx_mode)) != 0)
3029 		softdep_error("handle_workitem_freefile", error);
3030 	WORKITEM_FREE(freefile, D_FREEFILE);
3031 }
3032 
3033 /*
3034  * Helper function which unlinks marker element from work list and returns
3035  * the next element on the list.
3036  */
3037 static __inline struct worklist *
3038 markernext(struct worklist *marker)
3039 {
3040 	struct worklist *next;
3041 
3042 	next = LIST_NEXT(marker, wk_list);
3043 	LIST_REMOVE(marker, wk_list);
3044 	return next;
3045 }
3046 
3047 /*
3048  * Disk writes.
3049  *
3050  * The dependency structures constructed above are most actively used when file
3051  * system blocks are written to disk.  No constraints are placed on when a
3052  * block can be written, but unsatisfied update dependencies are made safe by
3053  * modifying (or replacing) the source memory for the duration of the disk
3054  * write.  When the disk write completes, the memory block is again brought
3055  * up-to-date.
3056  *
3057  * In-core inode structure reclamation.
3058  *
3059  * Because there are a finite number of "in-core" inode structures, they are
3060  * reused regularly.  By transferring all inode-related dependencies to the
3061  * in-memory inode block and indexing them separately (via "inodedep"s), we
3062  * can allow "in-core" inode structures to be reused at any time and avoid
3063  * any increase in contention.
3064  *
3065  * Called just before entering the device driver to initiate a new disk I/O.
3066  * The buffer must be locked, thus, no I/O completion operations can occur
3067  * while we are manipulating its associated dependencies.
3068  *
3069  * Parameters:
3070  *	bp:	structure describing disk write to occur
3071  */
3072 static void
3073 softdep_disk_io_initiation(struct buf *bp)
3074 {
3075 	struct worklist *wk;
3076 	struct worklist marker;
3077 	struct indirdep *indirdep;
3078 
3079 	/*
3080 	 * We only care about write operations. There should never
3081 	 * be dependencies for reads.
3082 	 */
3083 	if (bp->b_cmd == BUF_CMD_READ)
3084 		panic("softdep_disk_io_initiation: read");
3085 
3086 	marker.wk_type = D_LAST + 1;	/* Not a normal workitem */
3087 
3088 	/*
3089 	 * Do any necessary pre-I/O processing.
3090 	 */
3091 	for (wk = LIST_FIRST(&bp->b_dep); wk; wk = markernext(&marker)) {
3092 		LIST_INSERT_AFTER(wk, &marker, wk_list);
3093 
3094 		switch (wk->wk_type) {
3095 
3096 		case D_PAGEDEP:
3097 			initiate_write_filepage(WK_PAGEDEP(wk), bp);
3098 			continue;
3099 
3100 		case D_INODEDEP:
3101 			initiate_write_inodeblock(WK_INODEDEP(wk), bp);
3102 			continue;
3103 
3104 		case D_INDIRDEP:
3105 			indirdep = WK_INDIRDEP(wk);
3106 			if (indirdep->ir_state & GOINGAWAY)
3107 				panic("disk_io_initiation: indirdep gone");
3108 			/*
3109 			 * If there are no remaining dependencies, this
3110 			 * will be writing the real pointers, so the
3111 			 * dependency can be freed.
3112 			 */
3113 			if (LIST_FIRST(&indirdep->ir_deplisthd) == NULL) {
3114 				indirdep->ir_savebp->b_flags |= B_INVAL | B_NOCACHE;
3115 				brelse(indirdep->ir_savebp);
3116 				/* inline expand WORKLIST_REMOVE(wk); */
3117 				wk->wk_state &= ~ONWORKLIST;
3118 				LIST_REMOVE(wk, wk_list);
3119 				WORKITEM_FREE(indirdep, D_INDIRDEP);
3120 				continue;
3121 			}
3122 			/*
3123 			 * Replace up-to-date version with safe version.
3124 			 */
3125 			MALLOC(indirdep->ir_saveddata, caddr_t, bp->b_bcount,
3126 			    M_INDIRDEP, M_SOFTDEP_FLAGS);
3127 			ACQUIRE_LOCK(&lk);
3128 			indirdep->ir_state &= ~ATTACHED;
3129 			indirdep->ir_state |= UNDONE;
3130 			bcopy(bp->b_data, indirdep->ir_saveddata, bp->b_bcount);
3131 			bcopy(indirdep->ir_savebp->b_data, bp->b_data,
3132 			    bp->b_bcount);
3133 			FREE_LOCK(&lk);
3134 			continue;
3135 
3136 		case D_MKDIR:
3137 		case D_BMSAFEMAP:
3138 		case D_ALLOCDIRECT:
3139 		case D_ALLOCINDIR:
3140 			continue;
3141 
3142 		default:
3143 			panic("handle_disk_io_initiation: Unexpected type %s",
3144 			    TYPENAME(wk->wk_type));
3145 			/* NOTREACHED */
3146 		}
3147 	}
3148 }
3149 
3150 /*
3151  * Called from within the procedure above to deal with unsatisfied
3152  * allocation dependencies in a directory. The buffer must be locked,
3153  * thus, no I/O completion operations can occur while we are
3154  * manipulating its associated dependencies.
3155  */
3156 static void
3157 initiate_write_filepage(struct pagedep *pagedep, struct buf *bp)
3158 {
3159 	struct diradd *dap;
3160 	struct direct *ep;
3161 	int i;
3162 
3163 	if (pagedep->pd_state & IOSTARTED) {
3164 		/*
3165 		 * This can only happen if there is a driver that does not
3166 		 * understand chaining. Here biodone will reissue the call
3167 		 * to strategy for the incomplete buffers.
3168 		 */
3169 		kprintf("initiate_write_filepage: already started\n");
3170 		return;
3171 	}
3172 	pagedep->pd_state |= IOSTARTED;
3173 	ACQUIRE_LOCK(&lk);
3174 	for (i = 0; i < DAHASHSZ; i++) {
3175 		LIST_FOREACH(dap, &pagedep->pd_diraddhd[i], da_pdlist) {
3176 			ep = (struct direct *)
3177 			    ((char *)bp->b_data + dap->da_offset);
3178 			if (ep->d_ino != dap->da_newinum) {
3179 				FREE_LOCK(&lk);
3180 				panic("%s: dir inum %d != new %"PRId64,
3181 				    "initiate_write_filepage",
3182 				    ep->d_ino, dap->da_newinum);
3183 			}
3184 			if (dap->da_state & DIRCHG)
3185 				ep->d_ino = dap->da_previous->dm_oldinum;
3186 			else
3187 				ep->d_ino = 0;
3188 			dap->da_state &= ~ATTACHED;
3189 			dap->da_state |= UNDONE;
3190 		}
3191 	}
3192 	FREE_LOCK(&lk);
3193 }
3194 
3195 /*
3196  * Called from within the procedure above to deal with unsatisfied
3197  * allocation dependencies in an inodeblock. The buffer must be
3198  * locked, thus, no I/O completion operations can occur while we
3199  * are manipulating its associated dependencies.
3200  *
3201  * Parameters:
3202  *	bp:	The inode block
3203  */
3204 static void
3205 initiate_write_inodeblock(struct inodedep *inodedep, struct buf *bp)
3206 {
3207 	struct allocdirect *adp, *lastadp;
3208 	struct ufs1_dinode *dp;
3209 	struct ufs1_dinode *sip;
3210 	struct fs *fs;
3211 	ufs_lbn_t prevlbn = 0;
3212 	int i, deplist;
3213 
3214 	if (inodedep->id_state & IOSTARTED)
3215 		panic("initiate_write_inodeblock: already started");
3216 	inodedep->id_state |= IOSTARTED;
3217 	fs = inodedep->id_fs;
3218 	dp = (struct ufs1_dinode *)bp->b_data +
3219 	    ino_to_fsbo(fs, inodedep->id_ino);
3220 	/*
3221 	 * If the bitmap is not yet written, then the allocated
3222 	 * inode cannot be written to disk.
3223 	 */
3224 	if ((inodedep->id_state & DEPCOMPLETE) == 0) {
3225 		if (inodedep->id_savedino != NULL)
3226 			panic("initiate_write_inodeblock: already doing I/O");
3227 		MALLOC(sip, struct ufs1_dinode *,
3228 		    sizeof(struct ufs1_dinode), M_INODEDEP, M_SOFTDEP_FLAGS);
3229 		inodedep->id_savedino = sip;
3230 		*inodedep->id_savedino = *dp;
3231 		bzero((caddr_t)dp, sizeof(struct ufs1_dinode));
3232 		dp->di_gen = inodedep->id_savedino->di_gen;
3233 		return;
3234 	}
3235 	/*
3236 	 * If no dependencies, then there is nothing to roll back.
3237 	 */
3238 	inodedep->id_savedsize = dp->di_size;
3239 	if (TAILQ_FIRST(&inodedep->id_inoupdt) == NULL)
3240 		return;
3241 	/*
3242 	 * Set the dependencies to busy.
3243 	 */
3244 	ACQUIRE_LOCK(&lk);
3245 	for (deplist = 0, adp = TAILQ_FIRST(&inodedep->id_inoupdt); adp;
3246 	     adp = TAILQ_NEXT(adp, ad_next)) {
3247 #ifdef DIAGNOSTIC
3248 		if (deplist != 0 && prevlbn >= adp->ad_lbn) {
3249 			FREE_LOCK(&lk);
3250 			panic("softdep_write_inodeblock: lbn order");
3251 		}
3252 		prevlbn = adp->ad_lbn;
3253 		if (adp->ad_lbn < NDADDR &&
3254 		    dp->di_db[adp->ad_lbn] != adp->ad_newblkno) {
3255 			FREE_LOCK(&lk);
3256 			panic("%s: direct pointer #%ld mismatch %d != %d",
3257 			    "softdep_write_inodeblock", adp->ad_lbn,
3258 			    dp->di_db[adp->ad_lbn], adp->ad_newblkno);
3259 		}
3260 		if (adp->ad_lbn >= NDADDR &&
3261 		    dp->di_ib[adp->ad_lbn - NDADDR] != adp->ad_newblkno) {
3262 			FREE_LOCK(&lk);
3263 			panic("%s: indirect pointer #%ld mismatch %d != %d",
3264 			    "softdep_write_inodeblock", adp->ad_lbn - NDADDR,
3265 			    dp->di_ib[adp->ad_lbn - NDADDR], adp->ad_newblkno);
3266 		}
3267 		deplist |= 1 << adp->ad_lbn;
3268 		if ((adp->ad_state & ATTACHED) == 0) {
3269 			FREE_LOCK(&lk);
3270 			panic("softdep_write_inodeblock: Unknown state 0x%x",
3271 			    adp->ad_state);
3272 		}
3273 #endif /* DIAGNOSTIC */
3274 		adp->ad_state &= ~ATTACHED;
3275 		adp->ad_state |= UNDONE;
3276 	}
3277 	/*
3278 	 * The on-disk inode cannot claim to be any larger than the last
3279 	 * fragment that has been written. Otherwise, the on-disk inode
3280 	 * might have fragments that were not the last block in the file
3281 	 * which would corrupt the filesystem.
3282 	 */
3283 	for (lastadp = NULL, adp = TAILQ_FIRST(&inodedep->id_inoupdt); adp;
3284 	     lastadp = adp, adp = TAILQ_NEXT(adp, ad_next)) {
3285 		if (adp->ad_lbn >= NDADDR)
3286 			break;
3287 		dp->di_db[adp->ad_lbn] = adp->ad_oldblkno;
3288 		/* keep going until hitting a rollback to a frag */
3289 		if (adp->ad_oldsize == 0 || adp->ad_oldsize == fs->fs_bsize)
3290 			continue;
3291 		dp->di_size = fs->fs_bsize * adp->ad_lbn + adp->ad_oldsize;
3292 		for (i = adp->ad_lbn + 1; i < NDADDR; i++) {
3293 #ifdef DIAGNOSTIC
3294 			if (dp->di_db[i] != 0 && (deplist & (1 << i)) == 0) {
3295 				FREE_LOCK(&lk);
3296 				panic("softdep_write_inodeblock: lost dep1");
3297 			}
3298 #endif /* DIAGNOSTIC */
3299 			dp->di_db[i] = 0;
3300 		}
3301 		for (i = 0; i < NIADDR; i++) {
3302 #ifdef DIAGNOSTIC
3303 			if (dp->di_ib[i] != 0 &&
3304 			    (deplist & ((1 << NDADDR) << i)) == 0) {
3305 				FREE_LOCK(&lk);
3306 				panic("softdep_write_inodeblock: lost dep2");
3307 			}
3308 #endif /* DIAGNOSTIC */
3309 			dp->di_ib[i] = 0;
3310 		}
3311 		FREE_LOCK(&lk);
3312 		return;
3313 	}
3314 	/*
3315 	 * If we have zero'ed out the last allocated block of the file,
3316 	 * roll back the size to the last currently allocated block.
3317 	 * We know that this last allocated block is a full-sized as
3318 	 * we already checked for fragments in the loop above.
3319 	 */
3320 	if (lastadp != NULL &&
3321 	    dp->di_size <= (lastadp->ad_lbn + 1) * fs->fs_bsize) {
3322 		for (i = lastadp->ad_lbn; i >= 0; i--)
3323 			if (dp->di_db[i] != 0)
3324 				break;
3325 		dp->di_size = (i + 1) * fs->fs_bsize;
3326 	}
3327 	/*
3328 	 * The only dependencies are for indirect blocks.
3329 	 *
3330 	 * The file size for indirect block additions is not guaranteed.
3331 	 * Such a guarantee would be non-trivial to achieve. The conventional
3332 	 * synchronous write implementation also does not make this guarantee.
3333 	 * Fsck should catch and fix discrepancies. Arguably, the file size
3334 	 * can be over-estimated without destroying integrity when the file
3335 	 * moves into the indirect blocks (i.e., is large). If we want to
3336 	 * postpone fsck, we are stuck with this argument.
3337 	 */
3338 	for (; adp; adp = TAILQ_NEXT(adp, ad_next))
3339 		dp->di_ib[adp->ad_lbn - NDADDR] = 0;
3340 	FREE_LOCK(&lk);
3341 }
3342 
3343 /*
3344  * This routine is called during the completion interrupt
3345  * service routine for a disk write (from the procedure called
3346  * by the device driver to inform the filesystem caches of
3347  * a request completion).  It should be called early in this
3348  * procedure, before the block is made available to other
3349  * processes or other routines are called.
3350  *
3351  * Parameters:
3352  *	bp:	describes the completed disk write
3353  */
3354 static void
3355 softdep_disk_write_complete(struct buf *bp)
3356 {
3357 	struct worklist *wk;
3358 	struct workhead reattach;
3359 	struct newblk *newblk;
3360 	struct allocindir *aip;
3361 	struct allocdirect *adp;
3362 	struct indirdep *indirdep;
3363 	struct inodedep *inodedep;
3364 	struct bmsafemap *bmsafemap;
3365 
3366 #ifdef DEBUG
3367 	if (lk.lkt_held != NOHOLDER)
3368 		panic("softdep_disk_write_complete: lock is held");
3369 	lk.lkt_held = SPECIAL_FLAG;
3370 #endif
3371 	LIST_INIT(&reattach);
3372 	while ((wk = LIST_FIRST(&bp->b_dep)) != NULL) {
3373 		WORKLIST_REMOVE(wk);
3374 		switch (wk->wk_type) {
3375 
3376 		case D_PAGEDEP:
3377 			if (handle_written_filepage(WK_PAGEDEP(wk), bp))
3378 				WORKLIST_INSERT(&reattach, wk);
3379 			continue;
3380 
3381 		case D_INODEDEP:
3382 			if (handle_written_inodeblock(WK_INODEDEP(wk), bp))
3383 				WORKLIST_INSERT(&reattach, wk);
3384 			continue;
3385 
3386 		case D_BMSAFEMAP:
3387 			bmsafemap = WK_BMSAFEMAP(wk);
3388 			while ((newblk = LIST_FIRST(&bmsafemap->sm_newblkhd))) {
3389 				newblk->nb_state |= DEPCOMPLETE;
3390 				newblk->nb_bmsafemap = NULL;
3391 				LIST_REMOVE(newblk, nb_deps);
3392 			}
3393 			while ((adp =
3394 			   LIST_FIRST(&bmsafemap->sm_allocdirecthd))) {
3395 				adp->ad_state |= DEPCOMPLETE;
3396 				adp->ad_buf = NULL;
3397 				LIST_REMOVE(adp, ad_deps);
3398 				handle_allocdirect_partdone(adp);
3399 			}
3400 			while ((aip =
3401 			    LIST_FIRST(&bmsafemap->sm_allocindirhd))) {
3402 				aip->ai_state |= DEPCOMPLETE;
3403 				aip->ai_buf = NULL;
3404 				LIST_REMOVE(aip, ai_deps);
3405 				handle_allocindir_partdone(aip);
3406 			}
3407 			while ((inodedep =
3408 			     LIST_FIRST(&bmsafemap->sm_inodedephd)) != NULL) {
3409 				inodedep->id_state |= DEPCOMPLETE;
3410 				LIST_REMOVE(inodedep, id_deps);
3411 				inodedep->id_buf = NULL;
3412 			}
3413 			WORKITEM_FREE(bmsafemap, D_BMSAFEMAP);
3414 			continue;
3415 
3416 		case D_MKDIR:
3417 			handle_written_mkdir(WK_MKDIR(wk), MKDIR_BODY);
3418 			continue;
3419 
3420 		case D_ALLOCDIRECT:
3421 			adp = WK_ALLOCDIRECT(wk);
3422 			adp->ad_state |= COMPLETE;
3423 			handle_allocdirect_partdone(adp);
3424 			continue;
3425 
3426 		case D_ALLOCINDIR:
3427 			aip = WK_ALLOCINDIR(wk);
3428 			aip->ai_state |= COMPLETE;
3429 			handle_allocindir_partdone(aip);
3430 			continue;
3431 
3432 		case D_INDIRDEP:
3433 			indirdep = WK_INDIRDEP(wk);
3434 			if (indirdep->ir_state & GOINGAWAY) {
3435 				lk.lkt_held = NOHOLDER;
3436 				panic("disk_write_complete: indirdep gone");
3437 			}
3438 			bcopy(indirdep->ir_saveddata, bp->b_data, bp->b_bcount);
3439 			FREE(indirdep->ir_saveddata, M_INDIRDEP);
3440 			indirdep->ir_saveddata = 0;
3441 			indirdep->ir_state &= ~UNDONE;
3442 			indirdep->ir_state |= ATTACHED;
3443 			while ((aip = LIST_FIRST(&indirdep->ir_donehd)) != 0) {
3444 				handle_allocindir_partdone(aip);
3445 				if (aip == LIST_FIRST(&indirdep->ir_donehd)) {
3446 					lk.lkt_held = NOHOLDER;
3447 					panic("disk_write_complete: not gone");
3448 				}
3449 			}
3450 			WORKLIST_INSERT(&reattach, wk);
3451 			if ((bp->b_flags & B_DELWRI) == 0)
3452 				stat_indir_blk_ptrs++;
3453 			bdirty(bp);
3454 			continue;
3455 
3456 		default:
3457 			lk.lkt_held = NOHOLDER;
3458 			panic("handle_disk_write_complete: Unknown type %s",
3459 			    TYPENAME(wk->wk_type));
3460 			/* NOTREACHED */
3461 		}
3462 	}
3463 	/*
3464 	 * Reattach any requests that must be redone.
3465 	 */
3466 	while ((wk = LIST_FIRST(&reattach)) != NULL) {
3467 		WORKLIST_REMOVE(wk);
3468 		WORKLIST_INSERT(&bp->b_dep, wk);
3469 	}
3470 #ifdef DEBUG
3471 	if (lk.lkt_held != SPECIAL_FLAG)
3472 		panic("softdep_disk_write_complete: lock lost");
3473 	lk.lkt_held = NOHOLDER;
3474 #endif
3475 }
3476 
3477 /*
3478  * Called from within softdep_disk_write_complete above. Note that
3479  * this routine is always called from interrupt level with further
3480  * splbio interrupts blocked.
3481  *
3482  * Parameters:
3483  *	adp:	the completed allocdirect
3484  */
3485 static void
3486 handle_allocdirect_partdone(struct allocdirect *adp)
3487 {
3488 	struct allocdirect *listadp;
3489 	struct inodedep *inodedep;
3490 	long bsize;
3491 
3492 	if ((adp->ad_state & ALLCOMPLETE) != ALLCOMPLETE)
3493 		return;
3494 	if (adp->ad_buf != NULL) {
3495 		lk.lkt_held = NOHOLDER;
3496 		panic("handle_allocdirect_partdone: dangling dep");
3497 	}
3498 	/*
3499 	 * The on-disk inode cannot claim to be any larger than the last
3500 	 * fragment that has been written. Otherwise, the on-disk inode
3501 	 * might have fragments that were not the last block in the file
3502 	 * which would corrupt the filesystem. Thus, we cannot free any
3503 	 * allocdirects after one whose ad_oldblkno claims a fragment as
3504 	 * these blocks must be rolled back to zero before writing the inode.
3505 	 * We check the currently active set of allocdirects in id_inoupdt.
3506 	 */
3507 	inodedep = adp->ad_inodedep;
3508 	bsize = inodedep->id_fs->fs_bsize;
3509 	TAILQ_FOREACH(listadp, &inodedep->id_inoupdt, ad_next) {
3510 		/* found our block */
3511 		if (listadp == adp)
3512 			break;
3513 		/* continue if ad_oldlbn is not a fragment */
3514 		if (listadp->ad_oldsize == 0 ||
3515 		    listadp->ad_oldsize == bsize)
3516 			continue;
3517 		/* hit a fragment */
3518 		return;
3519 	}
3520 	/*
3521 	 * If we have reached the end of the current list without
3522 	 * finding the just finished dependency, then it must be
3523 	 * on the future dependency list. Future dependencies cannot
3524 	 * be freed until they are moved to the current list.
3525 	 */
3526 	if (listadp == NULL) {
3527 #ifdef DEBUG
3528 		TAILQ_FOREACH(listadp, &inodedep->id_newinoupdt, ad_next)
3529 			/* found our block */
3530 			if (listadp == adp)
3531 				break;
3532 		if (listadp == NULL) {
3533 			lk.lkt_held = NOHOLDER;
3534 			panic("handle_allocdirect_partdone: lost dep");
3535 		}
3536 #endif /* DEBUG */
3537 		return;
3538 	}
3539 	/*
3540 	 * If we have found the just finished dependency, then free
3541 	 * it along with anything that follows it that is complete.
3542 	 */
3543 	for (; adp; adp = listadp) {
3544 		listadp = TAILQ_NEXT(adp, ad_next);
3545 		if ((adp->ad_state & ALLCOMPLETE) != ALLCOMPLETE)
3546 			return;
3547 		free_allocdirect(&inodedep->id_inoupdt, adp, 1);
3548 	}
3549 }
3550 
3551 /*
3552  * Called from within softdep_disk_write_complete above. Note that
3553  * this routine is always called from interrupt level with further
3554  * splbio interrupts blocked.
3555  *
3556  * Parameters:
3557  *	aip:	the completed allocindir
3558  */
3559 static void
3560 handle_allocindir_partdone(struct allocindir *aip)
3561 {
3562 	struct indirdep *indirdep;
3563 
3564 	if ((aip->ai_state & ALLCOMPLETE) != ALLCOMPLETE)
3565 		return;
3566 	if (aip->ai_buf != NULL) {
3567 		lk.lkt_held = NOHOLDER;
3568 		panic("handle_allocindir_partdone: dangling dependency");
3569 	}
3570 	indirdep = aip->ai_indirdep;
3571 	if (indirdep->ir_state & UNDONE) {
3572 		LIST_REMOVE(aip, ai_next);
3573 		LIST_INSERT_HEAD(&indirdep->ir_donehd, aip, ai_next);
3574 		return;
3575 	}
3576 	((ufs_daddr_t *)indirdep->ir_savebp->b_data)[aip->ai_offset] =
3577 	    aip->ai_newblkno;
3578 	LIST_REMOVE(aip, ai_next);
3579 	if (aip->ai_freefrag != NULL)
3580 		add_to_worklist(&aip->ai_freefrag->ff_list);
3581 	WORKITEM_FREE(aip, D_ALLOCINDIR);
3582 }
3583 
3584 /*
3585  * Called from within softdep_disk_write_complete above to restore
3586  * in-memory inode block contents to their most up-to-date state. Note
3587  * that this routine is always called from interrupt level with further
3588  * splbio interrupts blocked.
3589  *
3590  * Parameters:
3591  *	bp:	buffer containing the inode block
3592  */
3593 static int
3594 handle_written_inodeblock(struct inodedep *inodedep, struct buf *bp)
3595 {
3596 	struct worklist *wk, *filefree;
3597 	struct allocdirect *adp, *nextadp;
3598 	struct ufs1_dinode *dp;
3599 	int hadchanges;
3600 
3601 	if ((inodedep->id_state & IOSTARTED) == 0) {
3602 		lk.lkt_held = NOHOLDER;
3603 		panic("handle_written_inodeblock: not started");
3604 	}
3605 	inodedep->id_state &= ~IOSTARTED;
3606 	dp = (struct ufs1_dinode *)bp->b_data +
3607 	    ino_to_fsbo(inodedep->id_fs, inodedep->id_ino);
3608 	/*
3609 	 * If we had to rollback the inode allocation because of
3610 	 * bitmaps being incomplete, then simply restore it.
3611 	 * Keep the block dirty so that it will not be reclaimed until
3612 	 * all associated dependencies have been cleared and the
3613 	 * corresponding updates written to disk.
3614 	 */
3615 	if (inodedep->id_savedino != NULL) {
3616 		*dp = *inodedep->id_savedino;
3617 		FREE(inodedep->id_savedino, M_INODEDEP);
3618 		inodedep->id_savedino = NULL;
3619 		if ((bp->b_flags & B_DELWRI) == 0)
3620 			stat_inode_bitmap++;
3621 		bdirty(bp);
3622 		return (1);
3623 	}
3624 	inodedep->id_state |= COMPLETE;
3625 	/*
3626 	 * Roll forward anything that had to be rolled back before
3627 	 * the inode could be updated.
3628 	 */
3629 	hadchanges = 0;
3630 	for (adp = TAILQ_FIRST(&inodedep->id_inoupdt); adp; adp = nextadp) {
3631 		nextadp = TAILQ_NEXT(adp, ad_next);
3632 		if (adp->ad_state & ATTACHED) {
3633 			lk.lkt_held = NOHOLDER;
3634 			panic("handle_written_inodeblock: new entry");
3635 		}
3636 		if (adp->ad_lbn < NDADDR) {
3637 			if (dp->di_db[adp->ad_lbn] != adp->ad_oldblkno) {
3638 				lk.lkt_held = NOHOLDER;
3639 				panic("%s: %s #%ld mismatch %d != %d",
3640 				    "handle_written_inodeblock",
3641 				    "direct pointer", adp->ad_lbn,
3642 				    dp->di_db[adp->ad_lbn], adp->ad_oldblkno);
3643 			}
3644 			dp->di_db[adp->ad_lbn] = adp->ad_newblkno;
3645 		} else {
3646 			if (dp->di_ib[adp->ad_lbn - NDADDR] != 0) {
3647 				lk.lkt_held = NOHOLDER;
3648 				panic("%s: %s #%ld allocated as %d",
3649 				    "handle_written_inodeblock",
3650 				    "indirect pointer", adp->ad_lbn - NDADDR,
3651 				    dp->di_ib[adp->ad_lbn - NDADDR]);
3652 			}
3653 			dp->di_ib[adp->ad_lbn - NDADDR] = adp->ad_newblkno;
3654 		}
3655 		adp->ad_state &= ~UNDONE;
3656 		adp->ad_state |= ATTACHED;
3657 		hadchanges = 1;
3658 	}
3659 	if (hadchanges && (bp->b_flags & B_DELWRI) == 0)
3660 		stat_direct_blk_ptrs++;
3661 	/*
3662 	 * Reset the file size to its most up-to-date value.
3663 	 */
3664 	if (inodedep->id_savedsize == -1) {
3665 		lk.lkt_held = NOHOLDER;
3666 		panic("handle_written_inodeblock: bad size");
3667 	}
3668 	if (dp->di_size != inodedep->id_savedsize) {
3669 		dp->di_size = inodedep->id_savedsize;
3670 		hadchanges = 1;
3671 	}
3672 	inodedep->id_savedsize = -1;
3673 	/*
3674 	 * If there were any rollbacks in the inode block, then it must be
3675 	 * marked dirty so that its will eventually get written back in
3676 	 * its correct form.
3677 	 */
3678 	if (hadchanges)
3679 		bdirty(bp);
3680 	/*
3681 	 * Process any allocdirects that completed during the update.
3682 	 */
3683 	if ((adp = TAILQ_FIRST(&inodedep->id_inoupdt)) != NULL)
3684 		handle_allocdirect_partdone(adp);
3685 	/*
3686 	 * Process deallocations that were held pending until the
3687 	 * inode had been written to disk. Freeing of the inode
3688 	 * is delayed until after all blocks have been freed to
3689 	 * avoid creation of new <vfsid, inum, lbn> triples
3690 	 * before the old ones have been deleted.
3691 	 */
3692 	filefree = NULL;
3693 	while ((wk = LIST_FIRST(&inodedep->id_bufwait)) != NULL) {
3694 		WORKLIST_REMOVE(wk);
3695 		switch (wk->wk_type) {
3696 
3697 		case D_FREEFILE:
3698 			/*
3699 			 * We defer adding filefree to the worklist until
3700 			 * all other additions have been made to ensure
3701 			 * that it will be done after all the old blocks
3702 			 * have been freed.
3703 			 */
3704 			if (filefree != NULL) {
3705 				lk.lkt_held = NOHOLDER;
3706 				panic("handle_written_inodeblock: filefree");
3707 			}
3708 			filefree = wk;
3709 			continue;
3710 
3711 		case D_MKDIR:
3712 			handle_written_mkdir(WK_MKDIR(wk), MKDIR_PARENT);
3713 			continue;
3714 
3715 		case D_DIRADD:
3716 			diradd_inode_written(WK_DIRADD(wk), inodedep);
3717 			continue;
3718 
3719 		case D_FREEBLKS:
3720 			wk->wk_state |= COMPLETE;
3721 			if ((wk->wk_state  & ALLCOMPLETE) != ALLCOMPLETE)
3722 				continue;
3723 			/* -- fall through -- */
3724 		case D_FREEFRAG:
3725 		case D_DIRREM:
3726 			add_to_worklist(wk);
3727 			continue;
3728 
3729 		default:
3730 			lk.lkt_held = NOHOLDER;
3731 			panic("handle_written_inodeblock: Unknown type %s",
3732 			    TYPENAME(wk->wk_type));
3733 			/* NOTREACHED */
3734 		}
3735 	}
3736 	if (filefree != NULL) {
3737 		if (free_inodedep(inodedep) == 0) {
3738 			lk.lkt_held = NOHOLDER;
3739 			panic("handle_written_inodeblock: live inodedep");
3740 		}
3741 		add_to_worklist(filefree);
3742 		return (0);
3743 	}
3744 
3745 	/*
3746 	 * If no outstanding dependencies, free it.
3747 	 */
3748 	if (free_inodedep(inodedep) || TAILQ_FIRST(&inodedep->id_inoupdt) == 0)
3749 		return (0);
3750 	return (hadchanges);
3751 }
3752 
3753 /*
3754  * Process a diradd entry after its dependent inode has been written.
3755  * This routine must be called with splbio interrupts blocked.
3756  */
3757 static void
3758 diradd_inode_written(struct diradd *dap, struct inodedep *inodedep)
3759 {
3760 	struct pagedep *pagedep;
3761 
3762 	dap->da_state |= COMPLETE;
3763 	if ((dap->da_state & ALLCOMPLETE) == ALLCOMPLETE) {
3764 		if (dap->da_state & DIRCHG)
3765 			pagedep = dap->da_previous->dm_pagedep;
3766 		else
3767 			pagedep = dap->da_pagedep;
3768 		LIST_REMOVE(dap, da_pdlist);
3769 		LIST_INSERT_HEAD(&pagedep->pd_pendinghd, dap, da_pdlist);
3770 	}
3771 	WORKLIST_INSERT(&inodedep->id_pendinghd, &dap->da_list);
3772 }
3773 
3774 /*
3775  * Handle the completion of a mkdir dependency.
3776  */
3777 static void
3778 handle_written_mkdir(struct mkdir *mkdir, int type)
3779 {
3780 	struct diradd *dap;
3781 	struct pagedep *pagedep;
3782 
3783 	if (mkdir->md_state != type) {
3784 		lk.lkt_held = NOHOLDER;
3785 		panic("handle_written_mkdir: bad type");
3786 	}
3787 	dap = mkdir->md_diradd;
3788 	dap->da_state &= ~type;
3789 	if ((dap->da_state & (MKDIR_PARENT | MKDIR_BODY)) == 0)
3790 		dap->da_state |= DEPCOMPLETE;
3791 	if ((dap->da_state & ALLCOMPLETE) == ALLCOMPLETE) {
3792 		if (dap->da_state & DIRCHG)
3793 			pagedep = dap->da_previous->dm_pagedep;
3794 		else
3795 			pagedep = dap->da_pagedep;
3796 		LIST_REMOVE(dap, da_pdlist);
3797 		LIST_INSERT_HEAD(&pagedep->pd_pendinghd, dap, da_pdlist);
3798 	}
3799 	LIST_REMOVE(mkdir, md_mkdirs);
3800 	WORKITEM_FREE(mkdir, D_MKDIR);
3801 }
3802 
3803 /*
3804  * Called from within softdep_disk_write_complete above.
3805  * A write operation was just completed. Removed inodes can
3806  * now be freed and associated block pointers may be committed.
3807  * Note that this routine is always called from interrupt level
3808  * with further splbio interrupts blocked.
3809  *
3810  * Parameters:
3811  *	bp:	buffer containing the written page
3812  */
3813 static int
3814 handle_written_filepage(struct pagedep *pagedep, struct buf *bp)
3815 {
3816 	struct dirrem *dirrem;
3817 	struct diradd *dap, *nextdap;
3818 	struct direct *ep;
3819 	int i, chgs;
3820 
3821 	if ((pagedep->pd_state & IOSTARTED) == 0) {
3822 		lk.lkt_held = NOHOLDER;
3823 		panic("handle_written_filepage: not started");
3824 	}
3825 	pagedep->pd_state &= ~IOSTARTED;
3826 	/*
3827 	 * Process any directory removals that have been committed.
3828 	 */
3829 	while ((dirrem = LIST_FIRST(&pagedep->pd_dirremhd)) != NULL) {
3830 		LIST_REMOVE(dirrem, dm_next);
3831 		dirrem->dm_dirinum = pagedep->pd_ino;
3832 		add_to_worklist(&dirrem->dm_list);
3833 	}
3834 	/*
3835 	 * Free any directory additions that have been committed.
3836 	 */
3837 	while ((dap = LIST_FIRST(&pagedep->pd_pendinghd)) != NULL)
3838 		free_diradd(dap);
3839 	/*
3840 	 * Uncommitted directory entries must be restored.
3841 	 */
3842 	for (chgs = 0, i = 0; i < DAHASHSZ; i++) {
3843 		for (dap = LIST_FIRST(&pagedep->pd_diraddhd[i]); dap;
3844 		     dap = nextdap) {
3845 			nextdap = LIST_NEXT(dap, da_pdlist);
3846 			if (dap->da_state & ATTACHED) {
3847 				lk.lkt_held = NOHOLDER;
3848 				panic("handle_written_filepage: attached");
3849 			}
3850 			ep = (struct direct *)
3851 			    ((char *)bp->b_data + dap->da_offset);
3852 			ep->d_ino = dap->da_newinum;
3853 			dap->da_state &= ~UNDONE;
3854 			dap->da_state |= ATTACHED;
3855 			chgs = 1;
3856 			/*
3857 			 * If the inode referenced by the directory has
3858 			 * been written out, then the dependency can be
3859 			 * moved to the pending list.
3860 			 */
3861 			if ((dap->da_state & ALLCOMPLETE) == ALLCOMPLETE) {
3862 				LIST_REMOVE(dap, da_pdlist);
3863 				LIST_INSERT_HEAD(&pagedep->pd_pendinghd, dap,
3864 				    da_pdlist);
3865 			}
3866 		}
3867 	}
3868 	/*
3869 	 * If there were any rollbacks in the directory, then it must be
3870 	 * marked dirty so that its will eventually get written back in
3871 	 * its correct form.
3872 	 */
3873 	if (chgs) {
3874 		if ((bp->b_flags & B_DELWRI) == 0)
3875 			stat_dir_entry++;
3876 		bdirty(bp);
3877 	}
3878 	/*
3879 	 * If no dependencies remain, the pagedep will be freed.
3880 	 * Otherwise it will remain to update the page before it
3881 	 * is written back to disk.
3882 	 */
3883 	if (LIST_FIRST(&pagedep->pd_pendinghd) == 0) {
3884 		for (i = 0; i < DAHASHSZ; i++)
3885 			if (LIST_FIRST(&pagedep->pd_diraddhd[i]) != NULL)
3886 				break;
3887 		if (i == DAHASHSZ) {
3888 			LIST_REMOVE(pagedep, pd_hash);
3889 			WORKITEM_FREE(pagedep, D_PAGEDEP);
3890 			return (0);
3891 		}
3892 	}
3893 	return (1);
3894 }
3895 
3896 /*
3897  * Writing back in-core inode structures.
3898  *
3899  * The filesystem only accesses an inode's contents when it occupies an
3900  * "in-core" inode structure.  These "in-core" structures are separate from
3901  * the page frames used to cache inode blocks.  Only the latter are
3902  * transferred to/from the disk.  So, when the updated contents of the
3903  * "in-core" inode structure are copied to the corresponding in-memory inode
3904  * block, the dependencies are also transferred.  The following procedure is
3905  * called when copying a dirty "in-core" inode to a cached inode block.
3906  */
3907 
3908 /*
3909  * Called when an inode is loaded from disk. If the effective link count
3910  * differed from the actual link count when it was last flushed, then we
3911  * need to ensure that the correct effective link count is put back.
3912  *
3913  * Parameters:
3914  *	ip:	the "in_core" copy of the inode
3915  */
3916 void
3917 softdep_load_inodeblock(struct inode *ip)
3918 {
3919 	struct inodedep *inodedep;
3920 
3921 	/*
3922 	 * Check for alternate nlink count.
3923 	 */
3924 	ip->i_effnlink = ip->i_nlink;
3925 	ACQUIRE_LOCK(&lk);
3926 	if (inodedep_lookup(ip->i_fs, ip->i_number, 0, &inodedep) == 0) {
3927 		FREE_LOCK(&lk);
3928 		return;
3929 	}
3930 	ip->i_effnlink -= inodedep->id_nlinkdelta;
3931 	FREE_LOCK(&lk);
3932 }
3933 
3934 /*
3935  * This routine is called just before the "in-core" inode
3936  * information is to be copied to the in-memory inode block.
3937  * Recall that an inode block contains several inodes. If
3938  * the force flag is set, then the dependencies will be
3939  * cleared so that the update can always be made. Note that
3940  * the buffer is locked when this routine is called, so we
3941  * will never be in the middle of writing the inode block
3942  * to disk.
3943  *
3944  * Parameters:
3945  *	ip:		the "in_core" copy of the inode
3946  *	bp:		the buffer containing the inode block
3947  *	waitfor:	nonzero => update must be allowed
3948  */
3949 void
3950 softdep_update_inodeblock(struct inode *ip, struct buf *bp,
3951 			  int waitfor)
3952 {
3953 	struct inodedep *inodedep;
3954 	struct worklist *wk;
3955 	int error, gotit;
3956 
3957 	/*
3958 	 * If the effective link count is not equal to the actual link
3959 	 * count, then we must track the difference in an inodedep while
3960 	 * the inode is (potentially) tossed out of the cache. Otherwise,
3961 	 * if there is no existing inodedep, then there are no dependencies
3962 	 * to track.
3963 	 */
3964 	ACQUIRE_LOCK(&lk);
3965 	if (inodedep_lookup(ip->i_fs, ip->i_number, 0, &inodedep) == 0) {
3966 		FREE_LOCK(&lk);
3967 		if (ip->i_effnlink != ip->i_nlink)
3968 			panic("softdep_update_inodeblock: bad link count");
3969 		return;
3970 	}
3971 	if (inodedep->id_nlinkdelta != ip->i_nlink - ip->i_effnlink) {
3972 		FREE_LOCK(&lk);
3973 		panic("softdep_update_inodeblock: bad delta");
3974 	}
3975 	/*
3976 	 * Changes have been initiated. Anything depending on these
3977 	 * changes cannot occur until this inode has been written.
3978 	 */
3979 	inodedep->id_state &= ~COMPLETE;
3980 	if ((inodedep->id_state & ONWORKLIST) == 0)
3981 		WORKLIST_INSERT(&bp->b_dep, &inodedep->id_list);
3982 	/*
3983 	 * Any new dependencies associated with the incore inode must
3984 	 * now be moved to the list associated with the buffer holding
3985 	 * the in-memory copy of the inode. Once merged process any
3986 	 * allocdirects that are completed by the merger.
3987 	 */
3988 	merge_inode_lists(inodedep);
3989 	if (TAILQ_FIRST(&inodedep->id_inoupdt) != NULL)
3990 		handle_allocdirect_partdone(TAILQ_FIRST(&inodedep->id_inoupdt));
3991 	/*
3992 	 * Now that the inode has been pushed into the buffer, the
3993 	 * operations dependent on the inode being written to disk
3994 	 * can be moved to the id_bufwait so that they will be
3995 	 * processed when the buffer I/O completes.
3996 	 */
3997 	while ((wk = LIST_FIRST(&inodedep->id_inowait)) != NULL) {
3998 		WORKLIST_REMOVE(wk);
3999 		WORKLIST_INSERT(&inodedep->id_bufwait, wk);
4000 	}
4001 	/*
4002 	 * Newly allocated inodes cannot be written until the bitmap
4003 	 * that allocates them have been written (indicated by
4004 	 * DEPCOMPLETE being set in id_state). If we are doing a
4005 	 * forced sync (e.g., an fsync on a file), we force the bitmap
4006 	 * to be written so that the update can be done.
4007 	 */
4008 	if ((inodedep->id_state & DEPCOMPLETE) != 0 || waitfor == 0) {
4009 		FREE_LOCK(&lk);
4010 		return;
4011 	}
4012 	gotit = getdirtybuf(&inodedep->id_buf, MNT_WAIT);
4013 	FREE_LOCK(&lk);
4014 	if (gotit &&
4015 	    (error = bwrite(inodedep->id_buf)) != 0)
4016 		softdep_error("softdep_update_inodeblock: bwrite", error);
4017 }
4018 
4019 /*
4020  * Merge the new inode dependency list (id_newinoupdt) into the old
4021  * inode dependency list (id_inoupdt). This routine must be called
4022  * with splbio interrupts blocked.
4023  */
4024 static void
4025 merge_inode_lists(struct inodedep *inodedep)
4026 {
4027 	struct allocdirect *listadp, *newadp;
4028 
4029 	newadp = TAILQ_FIRST(&inodedep->id_newinoupdt);
4030 	for (listadp = TAILQ_FIRST(&inodedep->id_inoupdt); listadp && newadp;) {
4031 		if (listadp->ad_lbn < newadp->ad_lbn) {
4032 			listadp = TAILQ_NEXT(listadp, ad_next);
4033 			continue;
4034 		}
4035 		TAILQ_REMOVE(&inodedep->id_newinoupdt, newadp, ad_next);
4036 		TAILQ_INSERT_BEFORE(listadp, newadp, ad_next);
4037 		if (listadp->ad_lbn == newadp->ad_lbn) {
4038 			allocdirect_merge(&inodedep->id_inoupdt, newadp,
4039 			    listadp);
4040 			listadp = newadp;
4041 		}
4042 		newadp = TAILQ_FIRST(&inodedep->id_newinoupdt);
4043 	}
4044 	while ((newadp = TAILQ_FIRST(&inodedep->id_newinoupdt)) != NULL) {
4045 		TAILQ_REMOVE(&inodedep->id_newinoupdt, newadp, ad_next);
4046 		TAILQ_INSERT_TAIL(&inodedep->id_inoupdt, newadp, ad_next);
4047 	}
4048 }
4049 
4050 /*
4051  * If we are doing an fsync, then we must ensure that any directory
4052  * entries for the inode have been written after the inode gets to disk.
4053  *
4054  * Parameters:
4055  *	vp:	the "in_core" copy of the inode
4056  */
4057 static int
4058 softdep_fsync(struct vnode *vp)
4059 {
4060 	struct inodedep *inodedep;
4061 	struct pagedep *pagedep;
4062 	struct worklist *wk;
4063 	struct diradd *dap;
4064 	struct mount *mnt;
4065 	struct vnode *pvp;
4066 	struct inode *ip;
4067 	struct buf *bp;
4068 	struct fs *fs;
4069 	int error, flushparent;
4070 	ino_t parentino;
4071 	ufs_lbn_t lbn;
4072 
4073 	ip = VTOI(vp);
4074 	fs = ip->i_fs;
4075 	ACQUIRE_LOCK(&lk);
4076 	if (inodedep_lookup(fs, ip->i_number, 0, &inodedep) == 0) {
4077 		FREE_LOCK(&lk);
4078 		return (0);
4079 	}
4080 	if (LIST_FIRST(&inodedep->id_inowait) != NULL ||
4081 	    LIST_FIRST(&inodedep->id_bufwait) != NULL ||
4082 	    TAILQ_FIRST(&inodedep->id_inoupdt) != NULL ||
4083 	    TAILQ_FIRST(&inodedep->id_newinoupdt) != NULL) {
4084 		FREE_LOCK(&lk);
4085 		panic("softdep_fsync: pending ops");
4086 	}
4087 	for (error = 0, flushparent = 0; ; ) {
4088 		if ((wk = LIST_FIRST(&inodedep->id_pendinghd)) == NULL)
4089 			break;
4090 		if (wk->wk_type != D_DIRADD) {
4091 			FREE_LOCK(&lk);
4092 			panic("softdep_fsync: Unexpected type %s",
4093 			    TYPENAME(wk->wk_type));
4094 		}
4095 		dap = WK_DIRADD(wk);
4096 		/*
4097 		 * Flush our parent if this directory entry
4098 		 * has a MKDIR_PARENT dependency.
4099 		 */
4100 		if (dap->da_state & DIRCHG)
4101 			pagedep = dap->da_previous->dm_pagedep;
4102 		else
4103 			pagedep = dap->da_pagedep;
4104 		mnt = pagedep->pd_mnt;
4105 		parentino = pagedep->pd_ino;
4106 		lbn = pagedep->pd_lbn;
4107 		if ((dap->da_state & (MKDIR_BODY | COMPLETE)) != COMPLETE) {
4108 			FREE_LOCK(&lk);
4109 			panic("softdep_fsync: dirty");
4110 		}
4111 		flushparent = dap->da_state & MKDIR_PARENT;
4112 		/*
4113 		 * If we are being fsync'ed as part of vgone'ing this vnode,
4114 		 * then we will not be able to release and recover the
4115 		 * vnode below, so we just have to give up on writing its
4116 		 * directory entry out. It will eventually be written, just
4117 		 * not now, but then the user was not asking to have it
4118 		 * written, so we are not breaking any promises.
4119 		 */
4120 		if (vp->v_flag & VRECLAIMED)
4121 			break;
4122 		/*
4123 		 * We prevent deadlock by always fetching inodes from the
4124 		 * root, moving down the directory tree. Thus, when fetching
4125 		 * our parent directory, we must unlock ourselves before
4126 		 * requesting the lock on our parent. See the comment in
4127 		 * ufs_lookup for details on possible races.
4128 		 */
4129 		FREE_LOCK(&lk);
4130 		vn_unlock(vp);
4131 		error = VFS_VGET(mnt, parentino, &pvp);
4132 		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
4133 		if (error != 0)
4134 			return (error);
4135 		if (flushparent) {
4136 			if ((error = ffs_update(pvp, 1)) != 0) {
4137 				vput(pvp);
4138 				return (error);
4139 			}
4140 		}
4141 		/*
4142 		 * Flush directory page containing the inode's name.
4143 		 */
4144 		error = bread(pvp, lblktodoff(fs, lbn), blksize(fs, VTOI(pvp), lbn), &bp);
4145 		if (error == 0)
4146 			error = bwrite(bp);
4147 		vput(pvp);
4148 		if (error != 0)
4149 			return (error);
4150 		ACQUIRE_LOCK(&lk);
4151 		if (inodedep_lookup(fs, ip->i_number, 0, &inodedep) == 0)
4152 			break;
4153 	}
4154 	FREE_LOCK(&lk);
4155 	return (0);
4156 }
4157 
4158 /*
4159  * Flush all the dirty bitmaps associated with the block device
4160  * before flushing the rest of the dirty blocks so as to reduce
4161  * the number of dependencies that will have to be rolled back.
4162  */
4163 static int softdep_fsync_mountdev_bp(struct buf *bp, void *data);
4164 
4165 void
4166 softdep_fsync_mountdev(struct vnode *vp)
4167 {
4168 	if (!vn_isdisk(vp, NULL))
4169 		panic("softdep_fsync_mountdev: vnode not a disk");
4170 	ACQUIRE_LOCK(&lk);
4171 	RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree, NULL,
4172 		softdep_fsync_mountdev_bp, vp);
4173 	drain_output(vp, 1);
4174 	FREE_LOCK(&lk);
4175 }
4176 
4177 static int
4178 softdep_fsync_mountdev_bp(struct buf *bp, void *data)
4179 {
4180 	struct worklist *wk;
4181 	struct vnode *vp = data;
4182 
4183 	/*
4184 	 * If it is already scheduled, skip to the next buffer.
4185 	 */
4186 	if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT))
4187 		return(0);
4188 	if (bp->b_vp != vp || (bp->b_flags & B_DELWRI) == 0) {
4189 		BUF_UNLOCK(bp);
4190 		kprintf("softdep_fsync_mountdev_bp: warning, buffer %p ripped out from under vnode %p\n", bp, vp);
4191 		return(0);
4192 	}
4193 	/*
4194 	 * We are only interested in bitmaps with outstanding
4195 	 * dependencies.
4196 	 */
4197 	if ((wk = LIST_FIRST(&bp->b_dep)) == NULL ||
4198 	    wk->wk_type != D_BMSAFEMAP) {
4199 		BUF_UNLOCK(bp);
4200 		return(0);
4201 	}
4202 	bremfree(bp);
4203 	FREE_LOCK(&lk);
4204 	(void) bawrite(bp);
4205 	ACQUIRE_LOCK(&lk);
4206 	return(0);
4207 }
4208 
4209 /*
4210  * This routine is called when we are trying to synchronously flush a
4211  * file. This routine must eliminate any filesystem metadata dependencies
4212  * so that the syncing routine can succeed by pushing the dirty blocks
4213  * associated with the file. If any I/O errors occur, they are returned.
4214  */
4215 struct softdep_sync_metadata_info {
4216 	struct vnode *vp;
4217 	int waitfor;
4218 };
4219 
4220 static int softdep_sync_metadata_bp(struct buf *bp, void *data);
4221 
4222 int
4223 softdep_sync_metadata(struct vnode *vp, struct thread *td)
4224 {
4225 	struct softdep_sync_metadata_info info;
4226 	int error, waitfor;
4227 
4228 	/*
4229 	 * Check whether this vnode is involved in a filesystem
4230 	 * that is doing soft dependency processing.
4231 	 */
4232 	if (!vn_isdisk(vp, NULL)) {
4233 		if (!DOINGSOFTDEP(vp))
4234 			return (0);
4235 	} else
4236 		if (vp->v_rdev->si_mountpoint == NULL ||
4237 		    (vp->v_rdev->si_mountpoint->mnt_flag & MNT_SOFTDEP) == 0)
4238 			return (0);
4239 	/*
4240 	 * Ensure that any direct block dependencies have been cleared.
4241 	 */
4242 	ACQUIRE_LOCK(&lk);
4243 	if ((error = flush_inodedep_deps(VTOI(vp)->i_fs, VTOI(vp)->i_number))) {
4244 		FREE_LOCK(&lk);
4245 		return (error);
4246 	}
4247 	/*
4248 	 * For most files, the only metadata dependencies are the
4249 	 * cylinder group maps that allocate their inode or blocks.
4250 	 * The block allocation dependencies can be found by traversing
4251 	 * the dependency lists for any buffers that remain on their
4252 	 * dirty buffer list. The inode allocation dependency will
4253 	 * be resolved when the inode is updated with MNT_WAIT.
4254 	 * This work is done in two passes. The first pass grabs most
4255 	 * of the buffers and begins asynchronously writing them. The
4256 	 * only way to wait for these asynchronous writes is to sleep
4257 	 * on the filesystem vnode which may stay busy for a long time
4258 	 * if the filesystem is active. So, instead, we make a second
4259 	 * pass over the dependencies blocking on each write. In the
4260 	 * usual case we will be blocking against a write that we
4261 	 * initiated, so when it is done the dependency will have been
4262 	 * resolved. Thus the second pass is expected to end quickly.
4263 	 */
4264 	waitfor = MNT_NOWAIT;
4265 top:
4266 	/*
4267 	 * We must wait for any I/O in progress to finish so that
4268 	 * all potential buffers on the dirty list will be visible.
4269 	 */
4270 	drain_output(vp, 1);
4271 	info.vp = vp;
4272 	info.waitfor = waitfor;
4273 	error = RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree, NULL,
4274 			softdep_sync_metadata_bp, &info);
4275 	if (error < 0) {
4276 		FREE_LOCK(&lk);
4277 		return(-error);	/* error code */
4278 	}
4279 
4280 	/*
4281 	 * The brief unlock is to allow any pent up dependency
4282 	 * processing to be done.  Then proceed with the second pass.
4283 	 */
4284 	if (waitfor == MNT_NOWAIT) {
4285 		waitfor = MNT_WAIT;
4286 		FREE_LOCK(&lk);
4287 		ACQUIRE_LOCK(&lk);
4288 		goto top;
4289 	}
4290 
4291 	/*
4292 	 * If we have managed to get rid of all the dirty buffers,
4293 	 * then we are done. For certain directories and block
4294 	 * devices, we may need to do further work.
4295 	 *
4296 	 * We must wait for any I/O in progress to finish so that
4297 	 * all potential buffers on the dirty list will be visible.
4298 	 */
4299 	drain_output(vp, 1);
4300 	if (RB_EMPTY(&vp->v_rbdirty_tree)) {
4301 		FREE_LOCK(&lk);
4302 		return (0);
4303 	}
4304 
4305 	FREE_LOCK(&lk);
4306 	/*
4307 	 * If we are trying to sync a block device, some of its buffers may
4308 	 * contain metadata that cannot be written until the contents of some
4309 	 * partially written files have been written to disk. The only easy
4310 	 * way to accomplish this is to sync the entire filesystem (luckily
4311 	 * this happens rarely).
4312 	 */
4313 	if (vn_isdisk(vp, NULL) &&
4314 	    vp->v_rdev &&
4315 	    vp->v_rdev->si_mountpoint && !vn_islocked(vp) &&
4316 	    (error = VFS_SYNC(vp->v_rdev->si_mountpoint, MNT_WAIT)) != 0)
4317 		return (error);
4318 	return (0);
4319 }
4320 
4321 static int
4322 softdep_sync_metadata_bp(struct buf *bp, void *data)
4323 {
4324 	struct softdep_sync_metadata_info *info = data;
4325 	struct pagedep *pagedep;
4326 	struct allocdirect *adp;
4327 	struct allocindir *aip;
4328 	struct worklist *wk;
4329 	struct buf *nbp;
4330 	int error;
4331 	int i;
4332 
4333 	if (getdirtybuf(&bp, MNT_WAIT) == 0) {
4334 		kprintf("softdep_sync_metadata_bp(1): caught buf %p going away\n", bp);
4335 		return (1);
4336 	}
4337 	if (bp->b_vp != info->vp || (bp->b_flags & B_DELWRI) == 0) {
4338 		kprintf("softdep_sync_metadata_bp(2): caught buf %p going away vp %p\n", bp, info->vp);
4339 		BUF_UNLOCK(bp);
4340 		return(1);
4341 	}
4342 
4343 	/*
4344 	 * As we hold the buffer locked, none of its dependencies
4345 	 * will disappear.
4346 	 */
4347 	LIST_FOREACH(wk, &bp->b_dep, wk_list) {
4348 		switch (wk->wk_type) {
4349 
4350 		case D_ALLOCDIRECT:
4351 			adp = WK_ALLOCDIRECT(wk);
4352 			if (adp->ad_state & DEPCOMPLETE)
4353 				break;
4354 			nbp = adp->ad_buf;
4355 			if (getdirtybuf(&nbp, info->waitfor) == 0)
4356 				break;
4357 			FREE_LOCK(&lk);
4358 			if (info->waitfor == MNT_NOWAIT) {
4359 				bawrite(nbp);
4360 			} else if ((error = bwrite(nbp)) != 0) {
4361 				bawrite(bp);
4362 				ACQUIRE_LOCK(&lk);
4363 				return (-error);
4364 			}
4365 			ACQUIRE_LOCK(&lk);
4366 			break;
4367 
4368 		case D_ALLOCINDIR:
4369 			aip = WK_ALLOCINDIR(wk);
4370 			if (aip->ai_state & DEPCOMPLETE)
4371 				break;
4372 			nbp = aip->ai_buf;
4373 			if (getdirtybuf(&nbp, info->waitfor) == 0)
4374 				break;
4375 			FREE_LOCK(&lk);
4376 			if (info->waitfor == MNT_NOWAIT) {
4377 				bawrite(nbp);
4378 			} else if ((error = bwrite(nbp)) != 0) {
4379 				bawrite(bp);
4380 				ACQUIRE_LOCK(&lk);
4381 				return (-error);
4382 			}
4383 			ACQUIRE_LOCK(&lk);
4384 			break;
4385 
4386 		case D_INDIRDEP:
4387 		restart:
4388 
4389 			LIST_FOREACH(aip, &WK_INDIRDEP(wk)->ir_deplisthd, ai_next) {
4390 				if (aip->ai_state & DEPCOMPLETE)
4391 					continue;
4392 				nbp = aip->ai_buf;
4393 				if (getdirtybuf(&nbp, MNT_WAIT) == 0)
4394 					goto restart;
4395 				FREE_LOCK(&lk);
4396 				if ((error = bwrite(nbp)) != 0) {
4397 					bawrite(bp);
4398 					ACQUIRE_LOCK(&lk);
4399 					return (-error);
4400 				}
4401 				ACQUIRE_LOCK(&lk);
4402 				goto restart;
4403 			}
4404 			break;
4405 
4406 		case D_INODEDEP:
4407 			if ((error = flush_inodedep_deps(WK_INODEDEP(wk)->id_fs,
4408 			    WK_INODEDEP(wk)->id_ino)) != 0) {
4409 				FREE_LOCK(&lk);
4410 				bawrite(bp);
4411 				ACQUIRE_LOCK(&lk);
4412 				return (-error);
4413 			}
4414 			break;
4415 
4416 		case D_PAGEDEP:
4417 			/*
4418 			 * We are trying to sync a directory that may
4419 			 * have dependencies on both its own metadata
4420 			 * and/or dependencies on the inodes of any
4421 			 * recently allocated files. We walk its diradd
4422 			 * lists pushing out the associated inode.
4423 			 */
4424 			pagedep = WK_PAGEDEP(wk);
4425 			for (i = 0; i < DAHASHSZ; i++) {
4426 				if (LIST_FIRST(&pagedep->pd_diraddhd[i]) == 0)
4427 					continue;
4428 				if ((error =
4429 				    flush_pagedep_deps(info->vp,
4430 						pagedep->pd_mnt,
4431 						&pagedep->pd_diraddhd[i]))) {
4432 					FREE_LOCK(&lk);
4433 					bawrite(bp);
4434 					ACQUIRE_LOCK(&lk);
4435 					return (-error);
4436 				}
4437 			}
4438 			break;
4439 
4440 		case D_MKDIR:
4441 			/*
4442 			 * This case should never happen if the vnode has
4443 			 * been properly sync'ed. However, if this function
4444 			 * is used at a place where the vnode has not yet
4445 			 * been sync'ed, this dependency can show up. So,
4446 			 * rather than panic, just flush it.
4447 			 */
4448 			nbp = WK_MKDIR(wk)->md_buf;
4449 			if (getdirtybuf(&nbp, info->waitfor) == 0)
4450 				break;
4451 			FREE_LOCK(&lk);
4452 			if (info->waitfor == MNT_NOWAIT) {
4453 				bawrite(nbp);
4454 			} else if ((error = bwrite(nbp)) != 0) {
4455 				bawrite(bp);
4456 				ACQUIRE_LOCK(&lk);
4457 				return (-error);
4458 			}
4459 			ACQUIRE_LOCK(&lk);
4460 			break;
4461 
4462 		case D_BMSAFEMAP:
4463 			/*
4464 			 * This case should never happen if the vnode has
4465 			 * been properly sync'ed. However, if this function
4466 			 * is used at a place where the vnode has not yet
4467 			 * been sync'ed, this dependency can show up. So,
4468 			 * rather than panic, just flush it.
4469 			 *
4470 			 * nbp can wind up == bp if a device node for the
4471 			 * same filesystem is being fsynced at the same time,
4472 			 * leading to a panic if we don't catch the case.
4473 			 */
4474 			nbp = WK_BMSAFEMAP(wk)->sm_buf;
4475 			if (nbp == bp)
4476 				break;
4477 			if (getdirtybuf(&nbp, info->waitfor) == 0)
4478 				break;
4479 			FREE_LOCK(&lk);
4480 			if (info->waitfor == MNT_NOWAIT) {
4481 				bawrite(nbp);
4482 			} else if ((error = bwrite(nbp)) != 0) {
4483 				bawrite(bp);
4484 				ACQUIRE_LOCK(&lk);
4485 				return (-error);
4486 			}
4487 			ACQUIRE_LOCK(&lk);
4488 			break;
4489 
4490 		default:
4491 			FREE_LOCK(&lk);
4492 			panic("softdep_sync_metadata: Unknown type %s",
4493 			    TYPENAME(wk->wk_type));
4494 			/* NOTREACHED */
4495 		}
4496 	}
4497 	FREE_LOCK(&lk);
4498 	bawrite(bp);
4499 	ACQUIRE_LOCK(&lk);
4500 	return(0);
4501 }
4502 
4503 /*
4504  * Flush the dependencies associated with an inodedep.
4505  * Called with splbio blocked.
4506  */
4507 static int
4508 flush_inodedep_deps(struct fs *fs, ino_t ino)
4509 {
4510 	struct inodedep *inodedep;
4511 	struct allocdirect *adp;
4512 	int error, waitfor;
4513 	struct buf *bp;
4514 
4515 	/*
4516 	 * This work is done in two passes. The first pass grabs most
4517 	 * of the buffers and begins asynchronously writing them. The
4518 	 * only way to wait for these asynchronous writes is to sleep
4519 	 * on the filesystem vnode which may stay busy for a long time
4520 	 * if the filesystem is active. So, instead, we make a second
4521 	 * pass over the dependencies blocking on each write. In the
4522 	 * usual case we will be blocking against a write that we
4523 	 * initiated, so when it is done the dependency will have been
4524 	 * resolved. Thus the second pass is expected to end quickly.
4525 	 * We give a brief window at the top of the loop to allow
4526 	 * any pending I/O to complete.
4527 	 */
4528 	for (waitfor = MNT_NOWAIT; ; ) {
4529 		FREE_LOCK(&lk);
4530 		ACQUIRE_LOCK(&lk);
4531 		if (inodedep_lookup(fs, ino, 0, &inodedep) == 0)
4532 			return (0);
4533 		TAILQ_FOREACH(adp, &inodedep->id_inoupdt, ad_next) {
4534 			if (adp->ad_state & DEPCOMPLETE)
4535 				continue;
4536 			bp = adp->ad_buf;
4537 			if (getdirtybuf(&bp, waitfor) == 0) {
4538 				if (waitfor == MNT_NOWAIT)
4539 					continue;
4540 				break;
4541 			}
4542 			FREE_LOCK(&lk);
4543 			if (waitfor == MNT_NOWAIT) {
4544 				bawrite(bp);
4545 			} else if ((error = bwrite(bp)) != 0) {
4546 				ACQUIRE_LOCK(&lk);
4547 				return (error);
4548 			}
4549 			ACQUIRE_LOCK(&lk);
4550 			break;
4551 		}
4552 		if (adp != NULL)
4553 			continue;
4554 		TAILQ_FOREACH(adp, &inodedep->id_newinoupdt, ad_next) {
4555 			if (adp->ad_state & DEPCOMPLETE)
4556 				continue;
4557 			bp = adp->ad_buf;
4558 			if (getdirtybuf(&bp, waitfor) == 0) {
4559 				if (waitfor == MNT_NOWAIT)
4560 					continue;
4561 				break;
4562 			}
4563 			FREE_LOCK(&lk);
4564 			if (waitfor == MNT_NOWAIT) {
4565 				bawrite(bp);
4566 			} else if ((error = bwrite(bp)) != 0) {
4567 				ACQUIRE_LOCK(&lk);
4568 				return (error);
4569 			}
4570 			ACQUIRE_LOCK(&lk);
4571 			break;
4572 		}
4573 		if (adp != NULL)
4574 			continue;
4575 		/*
4576 		 * If pass2, we are done, otherwise do pass 2.
4577 		 */
4578 		if (waitfor == MNT_WAIT)
4579 			break;
4580 		waitfor = MNT_WAIT;
4581 	}
4582 	/*
4583 	 * Try freeing inodedep in case all dependencies have been removed.
4584 	 */
4585 	if (inodedep_lookup(fs, ino, 0, &inodedep) != 0)
4586 		(void) free_inodedep(inodedep);
4587 	return (0);
4588 }
4589 
4590 /*
4591  * Eliminate a pagedep dependency by flushing out all its diradd dependencies.
4592  * Called with splbio blocked.
4593  */
4594 static int
4595 flush_pagedep_deps(struct vnode *pvp, struct mount *mp,
4596 		   struct diraddhd *diraddhdp)
4597 {
4598 	struct inodedep *inodedep;
4599 	struct ufsmount *ump;
4600 	struct diradd *dap;
4601 	struct vnode *vp;
4602 	int gotit, error = 0;
4603 	struct buf *bp;
4604 	ino_t inum;
4605 
4606 	ump = VFSTOUFS(mp);
4607 	while ((dap = LIST_FIRST(diraddhdp)) != NULL) {
4608 		/*
4609 		 * Flush ourselves if this directory entry
4610 		 * has a MKDIR_PARENT dependency.
4611 		 */
4612 		if (dap->da_state & MKDIR_PARENT) {
4613 			FREE_LOCK(&lk);
4614 			if ((error = ffs_update(pvp, 1)) != 0)
4615 				break;
4616 			ACQUIRE_LOCK(&lk);
4617 			/*
4618 			 * If that cleared dependencies, go on to next.
4619 			 */
4620 			if (dap != LIST_FIRST(diraddhdp))
4621 				continue;
4622 			if (dap->da_state & MKDIR_PARENT) {
4623 				FREE_LOCK(&lk);
4624 				panic("flush_pagedep_deps: MKDIR_PARENT");
4625 			}
4626 		}
4627 		/*
4628 		 * A newly allocated directory must have its "." and
4629 		 * ".." entries written out before its name can be
4630 		 * committed in its parent. We do not want or need
4631 		 * the full semantics of a synchronous VOP_FSYNC as
4632 		 * that may end up here again, once for each directory
4633 		 * level in the filesystem. Instead, we push the blocks
4634 		 * and wait for them to clear. We have to fsync twice
4635 		 * because the first call may choose to defer blocks
4636 		 * that still have dependencies, but deferral will
4637 		 * happen at most once.
4638 		 */
4639 		inum = dap->da_newinum;
4640 		if (dap->da_state & MKDIR_BODY) {
4641 			FREE_LOCK(&lk);
4642 			if ((error = VFS_VGET(mp, inum, &vp)) != 0)
4643 				break;
4644 			if ((error=VOP_FSYNC(vp, MNT_NOWAIT)) ||
4645 			    (error=VOP_FSYNC(vp, MNT_NOWAIT))) {
4646 				vput(vp);
4647 				break;
4648 			}
4649 			drain_output(vp, 0);
4650 			vput(vp);
4651 			ACQUIRE_LOCK(&lk);
4652 			/*
4653 			 * If that cleared dependencies, go on to next.
4654 			 */
4655 			if (dap != LIST_FIRST(diraddhdp))
4656 				continue;
4657 			if (dap->da_state & MKDIR_BODY) {
4658 				FREE_LOCK(&lk);
4659 				panic("flush_pagedep_deps: MKDIR_BODY");
4660 			}
4661 		}
4662 		/*
4663 		 * Flush the inode on which the directory entry depends.
4664 		 * Having accounted for MKDIR_PARENT and MKDIR_BODY above,
4665 		 * the only remaining dependency is that the updated inode
4666 		 * count must get pushed to disk. The inode has already
4667 		 * been pushed into its inode buffer (via VOP_UPDATE) at
4668 		 * the time of the reference count change. So we need only
4669 		 * locate that buffer, ensure that there will be no rollback
4670 		 * caused by a bitmap dependency, then write the inode buffer.
4671 		 */
4672 		if (inodedep_lookup(ump->um_fs, inum, 0, &inodedep) == 0) {
4673 			FREE_LOCK(&lk);
4674 			panic("flush_pagedep_deps: lost inode");
4675 		}
4676 		/*
4677 		 * If the inode still has bitmap dependencies,
4678 		 * push them to disk.
4679 		 */
4680 		if ((inodedep->id_state & DEPCOMPLETE) == 0) {
4681 			gotit = getdirtybuf(&inodedep->id_buf, MNT_WAIT);
4682 			FREE_LOCK(&lk);
4683 			if (gotit && (error = bwrite(inodedep->id_buf)) != 0)
4684 				break;
4685 			ACQUIRE_LOCK(&lk);
4686 			if (dap != LIST_FIRST(diraddhdp))
4687 				continue;
4688 		}
4689 		/*
4690 		 * If the inode is still sitting in a buffer waiting
4691 		 * to be written, push it to disk.
4692 		 */
4693 		FREE_LOCK(&lk);
4694 		if ((error = bread(ump->um_devvp,
4695 			fsbtodoff(ump->um_fs, ino_to_fsba(ump->um_fs, inum)),
4696 		    (int)ump->um_fs->fs_bsize, &bp)) != 0)
4697 			break;
4698 		if ((error = bwrite(bp)) != 0)
4699 			break;
4700 		ACQUIRE_LOCK(&lk);
4701 		/*
4702 		 * If we have failed to get rid of all the dependencies
4703 		 * then something is seriously wrong.
4704 		 */
4705 		if (dap == LIST_FIRST(diraddhdp)) {
4706 			FREE_LOCK(&lk);
4707 			panic("flush_pagedep_deps: flush failed");
4708 		}
4709 	}
4710 	if (error)
4711 		ACQUIRE_LOCK(&lk);
4712 	return (error);
4713 }
4714 
4715 /*
4716  * A large burst of file addition or deletion activity can drive the
4717  * memory load excessively high. First attempt to slow things down
4718  * using the techniques below. If that fails, this routine requests
4719  * the offending operations to fall back to running synchronously
4720  * until the memory load returns to a reasonable level.
4721  */
4722 int
4723 softdep_slowdown(struct vnode *vp)
4724 {
4725 	int max_softdeps_hard;
4726 
4727 	max_softdeps_hard = max_softdeps * 11 / 10;
4728 	if (num_dirrem < max_softdeps_hard / 2 &&
4729 	    num_inodedep < max_softdeps_hard)
4730 		return (0);
4731 	stat_sync_limit_hit += 1;
4732 	return (1);
4733 }
4734 
4735 /*
4736  * If memory utilization has gotten too high, deliberately slow things
4737  * down and speed up the I/O processing.
4738  */
4739 static int
4740 request_cleanup(int resource, int islocked)
4741 {
4742 	struct thread *td = curthread;		/* XXX */
4743 
4744 	/*
4745 	 * We never hold up the filesystem syncer process.
4746 	 */
4747 	if (td == filesys_syncer)
4748 		return (0);
4749 	/*
4750 	 * First check to see if the work list has gotten backlogged.
4751 	 * If it has, co-opt this process to help clean up two entries.
4752 	 * Because this process may hold inodes locked, we cannot
4753 	 * handle any remove requests that might block on a locked
4754 	 * inode as that could lead to deadlock.
4755 	 */
4756 	if (num_on_worklist > max_softdeps / 10) {
4757 		if (islocked)
4758 			FREE_LOCK(&lk);
4759 		process_worklist_item(NULL, LK_NOWAIT);
4760 		process_worklist_item(NULL, LK_NOWAIT);
4761 		stat_worklist_push += 2;
4762 		if (islocked)
4763 			ACQUIRE_LOCK(&lk);
4764 		return(1);
4765 	}
4766 
4767 	/*
4768 	 * If we are resource constrained on inode dependencies, try
4769 	 * flushing some dirty inodes. Otherwise, we are constrained
4770 	 * by file deletions, so try accelerating flushes of directories
4771 	 * with removal dependencies. We would like to do the cleanup
4772 	 * here, but we probably hold an inode locked at this point and
4773 	 * that might deadlock against one that we try to clean. So,
4774 	 * the best that we can do is request the syncer daemon to do
4775 	 * the cleanup for us.
4776 	 */
4777 	switch (resource) {
4778 
4779 	case FLUSH_INODES:
4780 		stat_ino_limit_push += 1;
4781 		req_clear_inodedeps += 1;
4782 		stat_countp = &stat_ino_limit_hit;
4783 		break;
4784 
4785 	case FLUSH_REMOVE:
4786 		stat_blk_limit_push += 1;
4787 		req_clear_remove += 1;
4788 		stat_countp = &stat_blk_limit_hit;
4789 		break;
4790 
4791 	default:
4792 		if (islocked)
4793 			FREE_LOCK(&lk);
4794 		panic("request_cleanup: unknown type");
4795 	}
4796 	/*
4797 	 * Hopefully the syncer daemon will catch up and awaken us.
4798 	 * We wait at most tickdelay before proceeding in any case.
4799 	 */
4800 	if (islocked == 0)
4801 		ACQUIRE_LOCK(&lk);
4802 	proc_waiting += 1;
4803 	if (!callout_active(&handle))
4804 		callout_reset(&handle, tickdelay > 2 ? tickdelay : 2,
4805 			      pause_timer, NULL);
4806 	interlocked_sleep(&lk, SLEEP, (caddr_t)&proc_waiting, 0,
4807 	    "softupdate", 0);
4808 	proc_waiting -= 1;
4809 	if (islocked == 0)
4810 		FREE_LOCK(&lk);
4811 	return (1);
4812 }
4813 
4814 /*
4815  * Awaken processes pausing in request_cleanup and clear proc_waiting
4816  * to indicate that there is no longer a timer running.
4817  */
4818 void
4819 pause_timer(void *arg)
4820 {
4821 	*stat_countp += 1;
4822 	wakeup_one(&proc_waiting);
4823 	if (proc_waiting > 0)
4824 		callout_reset(&handle, tickdelay > 2 ? tickdelay : 2,
4825 			      pause_timer, NULL);
4826 	else
4827 		callout_deactivate(&handle);
4828 }
4829 
4830 /*
4831  * Flush out a directory with at least one removal dependency in an effort to
4832  * reduce the number of dirrem, freefile, and freeblks dependency structures.
4833  */
4834 static void
4835 clear_remove(struct thread *td)
4836 {
4837 	struct pagedep_hashhead *pagedephd;
4838 	struct pagedep *pagedep;
4839 	static int next = 0;
4840 	struct mount *mp;
4841 	struct vnode *vp;
4842 	int error, cnt;
4843 	ino_t ino;
4844 
4845 	ACQUIRE_LOCK(&lk);
4846 	for (cnt = 0; cnt < pagedep_hash; cnt++) {
4847 		pagedephd = &pagedep_hashtbl[next++];
4848 		if (next >= pagedep_hash)
4849 			next = 0;
4850 		LIST_FOREACH(pagedep, pagedephd, pd_hash) {
4851 			if (LIST_FIRST(&pagedep->pd_dirremhd) == NULL)
4852 				continue;
4853 			mp = pagedep->pd_mnt;
4854 			ino = pagedep->pd_ino;
4855 			FREE_LOCK(&lk);
4856 			if ((error = VFS_VGET(mp, ino, &vp)) != 0) {
4857 				softdep_error("clear_remove: vget", error);
4858 				return;
4859 			}
4860 			if ((error = VOP_FSYNC(vp, MNT_NOWAIT)))
4861 				softdep_error("clear_remove: fsync", error);
4862 			drain_output(vp, 0);
4863 			vput(vp);
4864 			return;
4865 		}
4866 	}
4867 	FREE_LOCK(&lk);
4868 }
4869 
4870 /*
4871  * Clear out a block of dirty inodes in an effort to reduce
4872  * the number of inodedep dependency structures.
4873  */
4874 struct clear_inodedeps_info {
4875 	struct fs *fs;
4876 	struct mount *mp;
4877 };
4878 
4879 static int
4880 clear_inodedeps_mountlist_callback(struct mount *mp, void *data)
4881 {
4882 	struct clear_inodedeps_info *info = data;
4883 
4884 	if ((mp->mnt_flag & MNT_SOFTDEP) && info->fs == VFSTOUFS(mp)->um_fs) {
4885 		info->mp = mp;
4886 		return(-1);
4887 	}
4888 	return(0);
4889 }
4890 
4891 static void
4892 clear_inodedeps(struct thread *td)
4893 {
4894 	struct clear_inodedeps_info info;
4895 	struct inodedep_hashhead *inodedephd;
4896 	struct inodedep *inodedep;
4897 	static int next = 0;
4898 	struct vnode *vp;
4899 	struct fs *fs;
4900 	int error, cnt;
4901 	ino_t firstino, lastino, ino;
4902 
4903 	ACQUIRE_LOCK(&lk);
4904 	/*
4905 	 * Pick a random inode dependency to be cleared.
4906 	 * We will then gather up all the inodes in its block
4907 	 * that have dependencies and flush them out.
4908 	 */
4909 	for (cnt = 0; cnt < inodedep_hash; cnt++) {
4910 		inodedephd = &inodedep_hashtbl[next++];
4911 		if (next >= inodedep_hash)
4912 			next = 0;
4913 		if ((inodedep = LIST_FIRST(inodedephd)) != NULL)
4914 			break;
4915 	}
4916 	if (inodedep == NULL) {
4917 		FREE_LOCK(&lk);
4918 		return;
4919 	}
4920 	/*
4921 	 * Ugly code to find mount point given pointer to superblock.
4922 	 */
4923 	fs = inodedep->id_fs;
4924 	info.mp = NULL;
4925 	info.fs = fs;
4926 	mountlist_scan(clear_inodedeps_mountlist_callback,
4927 			&info, MNTSCAN_FORWARD|MNTSCAN_NOBUSY);
4928 	/*
4929 	 * Find the last inode in the block with dependencies.
4930 	 */
4931 	firstino = inodedep->id_ino & ~(INOPB(fs) - 1);
4932 	for (lastino = firstino + INOPB(fs) - 1; lastino > firstino; lastino--)
4933 		if (inodedep_lookup(fs, lastino, 0, &inodedep) != 0)
4934 			break;
4935 	/*
4936 	 * Asynchronously push all but the last inode with dependencies.
4937 	 * Synchronously push the last inode with dependencies to ensure
4938 	 * that the inode block gets written to free up the inodedeps.
4939 	 */
4940 	for (ino = firstino; ino <= lastino; ino++) {
4941 		if (inodedep_lookup(fs, ino, 0, &inodedep) == 0)
4942 			continue;
4943 		FREE_LOCK(&lk);
4944 		if ((error = VFS_VGET(info.mp, ino, &vp)) != 0) {
4945 			softdep_error("clear_inodedeps: vget", error);
4946 			return;
4947 		}
4948 		if (ino == lastino) {
4949 			if ((error = VOP_FSYNC(vp, MNT_WAIT)))
4950 				softdep_error("clear_inodedeps: fsync1", error);
4951 		} else {
4952 			if ((error = VOP_FSYNC(vp, MNT_NOWAIT)))
4953 				softdep_error("clear_inodedeps: fsync2", error);
4954 			drain_output(vp, 0);
4955 		}
4956 		vput(vp);
4957 		ACQUIRE_LOCK(&lk);
4958 	}
4959 	FREE_LOCK(&lk);
4960 }
4961 
4962 /*
4963  * Function to determine if the buffer has outstanding dependencies
4964  * that will cause a roll-back if the buffer is written. If wantcount
4965  * is set, return number of dependencies, otherwise just yes or no.
4966  */
4967 static int
4968 softdep_count_dependencies(struct buf *bp, int wantcount)
4969 {
4970 	struct worklist *wk;
4971 	struct inodedep *inodedep;
4972 	struct indirdep *indirdep;
4973 	struct allocindir *aip;
4974 	struct pagedep *pagedep;
4975 	struct diradd *dap;
4976 	int i, retval;
4977 
4978 	retval = 0;
4979 	ACQUIRE_LOCK(&lk);
4980 	LIST_FOREACH(wk, &bp->b_dep, wk_list) {
4981 		switch (wk->wk_type) {
4982 
4983 		case D_INODEDEP:
4984 			inodedep = WK_INODEDEP(wk);
4985 			if ((inodedep->id_state & DEPCOMPLETE) == 0) {
4986 				/* bitmap allocation dependency */
4987 				retval += 1;
4988 				if (!wantcount)
4989 					goto out;
4990 			}
4991 			if (TAILQ_FIRST(&inodedep->id_inoupdt)) {
4992 				/* direct block pointer dependency */
4993 				retval += 1;
4994 				if (!wantcount)
4995 					goto out;
4996 			}
4997 			continue;
4998 
4999 		case D_INDIRDEP:
5000 			indirdep = WK_INDIRDEP(wk);
5001 
5002 			LIST_FOREACH(aip, &indirdep->ir_deplisthd, ai_next) {
5003 				/* indirect block pointer dependency */
5004 				retval += 1;
5005 				if (!wantcount)
5006 					goto out;
5007 			}
5008 			continue;
5009 
5010 		case D_PAGEDEP:
5011 			pagedep = WK_PAGEDEP(wk);
5012 			for (i = 0; i < DAHASHSZ; i++) {
5013 
5014 				LIST_FOREACH(dap, &pagedep->pd_diraddhd[i], da_pdlist) {
5015 					/* directory entry dependency */
5016 					retval += 1;
5017 					if (!wantcount)
5018 						goto out;
5019 				}
5020 			}
5021 			continue;
5022 
5023 		case D_BMSAFEMAP:
5024 		case D_ALLOCDIRECT:
5025 		case D_ALLOCINDIR:
5026 		case D_MKDIR:
5027 			/* never a dependency on these blocks */
5028 			continue;
5029 
5030 		default:
5031 			FREE_LOCK(&lk);
5032 			panic("softdep_check_for_rollback: Unexpected type %s",
5033 			    TYPENAME(wk->wk_type));
5034 			/* NOTREACHED */
5035 		}
5036 	}
5037 out:
5038 	FREE_LOCK(&lk);
5039 	return retval;
5040 }
5041 
5042 /*
5043  * Acquire exclusive access to a buffer.
5044  * Must be called with splbio blocked.
5045  * Return 1 if buffer was acquired.
5046  */
5047 static int
5048 getdirtybuf(struct buf **bpp, int waitfor)
5049 {
5050 	struct buf *bp;
5051 	int error;
5052 
5053 	for (;;) {
5054 		if ((bp = *bpp) == NULL)
5055 			return (0);
5056 		if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT) == 0)
5057 			break;
5058 		if (waitfor != MNT_WAIT)
5059 			return (0);
5060 		error = interlocked_sleep(&lk, LOCKBUF, bp,
5061 		    LK_EXCLUSIVE | LK_SLEEPFAIL, 0, 0);
5062 		if (error != ENOLCK) {
5063 			FREE_LOCK(&lk);
5064 			panic("getdirtybuf: inconsistent lock");
5065 		}
5066 	}
5067 	if ((bp->b_flags & B_DELWRI) == 0) {
5068 		BUF_UNLOCK(bp);
5069 		return (0);
5070 	}
5071 	bremfree(bp);
5072 	return (1);
5073 }
5074 
5075 /*
5076  * Wait for pending output on a vnode to complete.
5077  * Must be called with vnode locked.
5078  */
5079 static void
5080 drain_output(struct vnode *vp, int islocked)
5081 {
5082 
5083 	if (!islocked)
5084 		ACQUIRE_LOCK(&lk);
5085 	while (vp->v_track_write.bk_active) {
5086 		vp->v_track_write.bk_waitflag = 1;
5087 		interlocked_sleep(&lk, SLEEP, &vp->v_track_write,
5088 				  0, "drainvp", 0);
5089 	}
5090 	if (!islocked)
5091 		FREE_LOCK(&lk);
5092 }
5093 
5094 /*
5095  * Called whenever a buffer that is being invalidated or reallocated
5096  * contains dependencies. This should only happen if an I/O error has
5097  * occurred. The routine is called with the buffer locked.
5098  */
5099 static void
5100 softdep_deallocate_dependencies(struct buf *bp)
5101 {
5102 
5103 	if ((bp->b_flags & B_ERROR) == 0)
5104 		panic("softdep_deallocate_dependencies: dangling deps");
5105 	softdep_error(bp->b_vp->v_mount->mnt_stat.f_mntfromname, bp->b_error);
5106 	panic("softdep_deallocate_dependencies: unrecovered I/O error");
5107 }
5108 
5109 /*
5110  * Function to handle asynchronous write errors in the filesystem.
5111  */
5112 void
5113 softdep_error(char *func, int error)
5114 {
5115 
5116 	/* XXX should do something better! */
5117 	kprintf("%s: got error %d while accessing filesystem\n", func, error);
5118 }
5119