xref: /dragonfly/sys/kern/vfs_aio.c (revision ed5d5720)
1 /*
2  * Copyright (c) 1997 John S. Dyson.  All rights reserved.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. John S. Dyson's name may not be used to endorse or promote products
10  *    derived from this software without specific prior written permission.
11  *
12  * DISCLAIMER:  This code isn't warranted to do anything useful.  Anything
13  * bad that happens because of using this software isn't the responsibility
14  * of the author.  This software is distributed AS-IS.
15  *
16  * $FreeBSD: src/sys/kern/vfs_aio.c,v 1.70.2.28 2003/05/29 06:15:35 alc Exp $
17  * $DragonFly: src/sys/kern/vfs_aio.c,v 1.42 2007/07/20 17:21:52 dillon Exp $
18  */
19 
20 /*
21  * This file contains support for the POSIX 1003.1B AIO/LIO facility.
22  */
23 
24 #include <sys/param.h>
25 #include <sys/systm.h>
26 #include <sys/buf.h>
27 #include <sys/sysproto.h>
28 #include <sys/filedesc.h>
29 #include <sys/kernel.h>
30 #include <sys/fcntl.h>
31 #include <sys/file.h>
32 #include <sys/lock.h>
33 #include <sys/unistd.h>
34 #include <sys/proc.h>
35 #include <sys/resourcevar.h>
36 #include <sys/signalvar.h>
37 #include <sys/protosw.h>
38 #include <sys/socketvar.h>
39 #include <sys/sysctl.h>
40 #include <sys/vnode.h>
41 #include <sys/conf.h>
42 #include <sys/event.h>
43 
44 #include <vm/vm.h>
45 #include <vm/vm_extern.h>
46 #include <vm/pmap.h>
47 #include <vm/vm_map.h>
48 #include <vm/vm_zone.h>
49 #include <sys/aio.h>
50 #include <sys/file2.h>
51 #include <sys/buf2.h>
52 #include <sys/sysref2.h>
53 #include <sys/thread2.h>
54 
55 #include <machine/limits.h>
56 #include "opt_vfs_aio.h"
57 
58 #ifdef VFS_AIO
59 
60 /*
61  * Counter for allocating reference ids to new jobs.  Wrapped to 1 on
62  * overflow.
63  */
64 static	long jobrefid;
65 
66 #define JOBST_NULL		0x0
67 #define JOBST_JOBQGLOBAL	0x2
68 #define JOBST_JOBRUNNING	0x3
69 #define JOBST_JOBFINISHED	0x4
70 #define	JOBST_JOBQBUF		0x5
71 #define	JOBST_JOBBFINISHED	0x6
72 
73 #ifndef MAX_AIO_PER_PROC
74 #define MAX_AIO_PER_PROC	32
75 #endif
76 
77 #ifndef MAX_AIO_QUEUE_PER_PROC
78 #define MAX_AIO_QUEUE_PER_PROC	256 /* Bigger than AIO_LISTIO_MAX */
79 #endif
80 
81 #ifndef MAX_AIO_PROCS
82 #define MAX_AIO_PROCS		32
83 #endif
84 
85 #ifndef MAX_AIO_QUEUE
86 #define	MAX_AIO_QUEUE		1024 /* Bigger than AIO_LISTIO_MAX */
87 #endif
88 
89 #ifndef TARGET_AIO_PROCS
90 #define TARGET_AIO_PROCS	4
91 #endif
92 
93 #ifndef MAX_BUF_AIO
94 #define MAX_BUF_AIO		16
95 #endif
96 
97 #ifndef AIOD_TIMEOUT_DEFAULT
98 #define	AIOD_TIMEOUT_DEFAULT	(10 * hz)
99 #endif
100 
101 #ifndef AIOD_LIFETIME_DEFAULT
102 #define AIOD_LIFETIME_DEFAULT	(30 * hz)
103 #endif
104 
105 SYSCTL_NODE(_vfs, OID_AUTO, aio, CTLFLAG_RW, 0, "Async IO management");
106 
107 static int max_aio_procs = MAX_AIO_PROCS;
108 SYSCTL_INT(_vfs_aio, OID_AUTO, max_aio_procs,
109 	CTLFLAG_RW, &max_aio_procs, 0,
110 	"Maximum number of kernel threads to use for handling async IO");
111 
112 static int num_aio_procs = 0;
113 SYSCTL_INT(_vfs_aio, OID_AUTO, num_aio_procs,
114 	CTLFLAG_RD, &num_aio_procs, 0,
115 	"Number of presently active kernel threads for async IO");
116 
117 /*
118  * The code will adjust the actual number of AIO processes towards this
119  * number when it gets a chance.
120  */
121 static int target_aio_procs = TARGET_AIO_PROCS;
122 SYSCTL_INT(_vfs_aio, OID_AUTO, target_aio_procs, CTLFLAG_RW, &target_aio_procs,
123 	0, "Preferred number of ready kernel threads for async IO");
124 
125 static int max_queue_count = MAX_AIO_QUEUE;
126 SYSCTL_INT(_vfs_aio, OID_AUTO, max_aio_queue, CTLFLAG_RW, &max_queue_count, 0,
127     "Maximum number of aio requests to queue, globally");
128 
129 static int num_queue_count = 0;
130 SYSCTL_INT(_vfs_aio, OID_AUTO, num_queue_count, CTLFLAG_RD, &num_queue_count, 0,
131     "Number of queued aio requests");
132 
133 static int num_buf_aio = 0;
134 SYSCTL_INT(_vfs_aio, OID_AUTO, num_buf_aio, CTLFLAG_RD, &num_buf_aio, 0,
135     "Number of aio requests presently handled by the buf subsystem");
136 
137 /* Number of async I/O thread in the process of being started */
138 /* XXX This should be local to _aio_aqueue() */
139 static int num_aio_resv_start = 0;
140 
141 static int aiod_timeout;
142 SYSCTL_INT(_vfs_aio, OID_AUTO, aiod_timeout, CTLFLAG_RW, &aiod_timeout, 0,
143     "Timeout value for synchronous aio operations");
144 
145 static int aiod_lifetime;
146 SYSCTL_INT(_vfs_aio, OID_AUTO, aiod_lifetime, CTLFLAG_RW, &aiod_lifetime, 0,
147     "Maximum lifetime for idle aiod");
148 
149 static int max_aio_per_proc = MAX_AIO_PER_PROC;
150 SYSCTL_INT(_vfs_aio, OID_AUTO, max_aio_per_proc, CTLFLAG_RW, &max_aio_per_proc,
151     0, "Maximum active aio requests per process (stored in the process)");
152 
153 static int max_aio_queue_per_proc = MAX_AIO_QUEUE_PER_PROC;
154 SYSCTL_INT(_vfs_aio, OID_AUTO, max_aio_queue_per_proc, CTLFLAG_RW,
155     &max_aio_queue_per_proc, 0,
156     "Maximum queued aio requests per process (stored in the process)");
157 
158 static int max_buf_aio = MAX_BUF_AIO;
159 SYSCTL_INT(_vfs_aio, OID_AUTO, max_buf_aio, CTLFLAG_RW, &max_buf_aio, 0,
160     "Maximum buf aio requests per process (stored in the process)");
161 
162 /*
163  * AIO process info
164  */
165 #define AIOP_FREE	0x1			/* proc on free queue */
166 #define AIOP_SCHED	0x2			/* proc explicitly scheduled */
167 
168 struct aioproclist {
169 	int aioprocflags;			/* AIO proc flags */
170 	TAILQ_ENTRY(aioproclist) list;		/* List of processes */
171 	struct proc *aioproc;			/* The AIO thread */
172 };
173 
174 /*
175  * data-structure for lio signal management
176  */
177 struct aio_liojob {
178 	int	lioj_flags;
179 	int	lioj_buffer_count;
180 	int	lioj_buffer_finished_count;
181 	int	lioj_queue_count;
182 	int	lioj_queue_finished_count;
183 	struct	sigevent lioj_signal;	/* signal on all I/O done */
184 	TAILQ_ENTRY(aio_liojob) lioj_list;
185 	struct	kaioinfo *lioj_ki;
186 };
187 #define	LIOJ_SIGNAL		0x1	/* signal on all done (lio) */
188 #define	LIOJ_SIGNAL_POSTED	0x2	/* signal has been posted */
189 
190 /*
191  * per process aio data structure
192  */
193 struct kaioinfo {
194 	int	kaio_flags;		/* per process kaio flags */
195 	int	kaio_maxactive_count;	/* maximum number of AIOs */
196 	int	kaio_active_count;	/* number of currently used AIOs */
197 	int	kaio_qallowed_count;	/* maxiumu size of AIO queue */
198 	int	kaio_queue_count;	/* size of AIO queue */
199 	int	kaio_ballowed_count;	/* maximum number of buffers */
200 	int	kaio_queue_finished_count; /* number of daemon jobs finished */
201 	int	kaio_buffer_count;	/* number of physio buffers */
202 	int	kaio_buffer_finished_count; /* count of I/O done */
203 	struct 	proc *kaio_p;		/* process that uses this kaio block */
204 	TAILQ_HEAD(,aio_liojob) kaio_liojoblist; /* list of lio jobs */
205 	TAILQ_HEAD(,aiocblist) kaio_jobqueue;	/* job queue for process */
206 	TAILQ_HEAD(,aiocblist) kaio_jobdone;	/* done queue for process */
207 	TAILQ_HEAD(,aiocblist) kaio_bufqueue;	/* buffer job queue for process */
208 	TAILQ_HEAD(,aiocblist) kaio_bufdone;	/* buffer done queue for process */
209 	TAILQ_HEAD(,aiocblist) kaio_sockqueue;	/* queue for aios waiting on sockets */
210 };
211 
212 #define KAIO_RUNDOWN	0x1	/* process is being run down */
213 #define KAIO_WAKEUP	0x2	/* wakeup process when there is a significant event */
214 
215 static TAILQ_HEAD(,aioproclist) aio_freeproc, aio_activeproc;
216 static TAILQ_HEAD(,aiocblist) aio_jobs;			/* Async job list */
217 static TAILQ_HEAD(,aiocblist) aio_bufjobs;		/* Phys I/O job list */
218 static TAILQ_HEAD(,aiocblist) aio_freejobs;		/* Pool of free jobs */
219 
220 static void	aio_init_aioinfo(struct proc *p);
221 static void	aio_onceonly(void *);
222 static int	aio_free_entry(struct aiocblist *aiocbe);
223 static void	aio_process(struct aiocblist *aiocbe);
224 static int	aio_newproc(void);
225 static int	aio_aqueue(struct aiocb *job, int type);
226 static void	aio_physwakeup(struct bio *bio);
227 static int	aio_fphysio(struct aiocblist *aiocbe);
228 static int	aio_qphysio(struct proc *p, struct aiocblist *iocb);
229 static void	aio_daemon(void *uproc, struct trapframe *frame);
230 static void	process_signal(void *aioj);
231 
232 SYSINIT(aio, SI_SUB_VFS, SI_ORDER_ANY, aio_onceonly, NULL);
233 
234 /*
235  * Zones for:
236  * 	kaio	Per process async io info
237  *	aiop	async io thread data
238  *	aiocb	async io jobs
239  *	aiol	list io job pointer - internal to aio_suspend XXX
240  *	aiolio	list io jobs
241  */
242 static vm_zone_t kaio_zone, aiop_zone, aiocb_zone, aiol_zone, aiolio_zone;
243 
244 /*
245  * Startup initialization
246  */
247 static void
248 aio_onceonly(void *na)
249 {
250 	TAILQ_INIT(&aio_freeproc);
251 	TAILQ_INIT(&aio_activeproc);
252 	TAILQ_INIT(&aio_jobs);
253 	TAILQ_INIT(&aio_bufjobs);
254 	TAILQ_INIT(&aio_freejobs);
255 	kaio_zone = zinit("AIO", sizeof(struct kaioinfo), 0, 0, 1);
256 	aiop_zone = zinit("AIOP", sizeof(struct aioproclist), 0, 0, 1);
257 	aiocb_zone = zinit("AIOCB", sizeof(struct aiocblist), 0, 0, 1);
258 	aiol_zone = zinit("AIOL", AIO_LISTIO_MAX*sizeof(intptr_t), 0, 0, 1);
259 	aiolio_zone = zinit("AIOLIO", sizeof(struct aio_liojob), 0, 0, 1);
260 	aiod_timeout = AIOD_TIMEOUT_DEFAULT;
261 	aiod_lifetime = AIOD_LIFETIME_DEFAULT;
262 	jobrefid = 1;
263 }
264 
265 /*
266  * Init the per-process aioinfo structure.  The aioinfo limits are set
267  * per-process for user limit (resource) management.
268  */
269 static void
270 aio_init_aioinfo(struct proc *p)
271 {
272 	struct kaioinfo *ki;
273 	if (p->p_aioinfo == NULL) {
274 		ki = zalloc(kaio_zone);
275 		p->p_aioinfo = ki;
276 		ki->kaio_flags = 0;
277 		ki->kaio_maxactive_count = max_aio_per_proc;
278 		ki->kaio_active_count = 0;
279 		ki->kaio_qallowed_count = max_aio_queue_per_proc;
280 		ki->kaio_queue_count = 0;
281 		ki->kaio_ballowed_count = max_buf_aio;
282 		ki->kaio_buffer_count = 0;
283 		ki->kaio_buffer_finished_count = 0;
284 		ki->kaio_p = p;
285 		TAILQ_INIT(&ki->kaio_jobdone);
286 		TAILQ_INIT(&ki->kaio_jobqueue);
287 		TAILQ_INIT(&ki->kaio_bufdone);
288 		TAILQ_INIT(&ki->kaio_bufqueue);
289 		TAILQ_INIT(&ki->kaio_liojoblist);
290 		TAILQ_INIT(&ki->kaio_sockqueue);
291 	}
292 
293 	while (num_aio_procs < target_aio_procs)
294 		aio_newproc();
295 }
296 
297 /*
298  * Free a job entry.  Wait for completion if it is currently active, but don't
299  * delay forever.  If we delay, we return a flag that says that we have to
300  * restart the queue scan.
301  */
302 static int
303 aio_free_entry(struct aiocblist *aiocbe)
304 {
305 	struct kaioinfo *ki;
306 	struct aio_liojob *lj;
307 	struct proc *p;
308 	int error;
309 
310 	if (aiocbe->jobstate == JOBST_NULL)
311 		panic("aio_free_entry: freeing already free job");
312 
313 	p = aiocbe->userproc;
314 	ki = p->p_aioinfo;
315 	lj = aiocbe->lio;
316 	if (ki == NULL)
317 		panic("aio_free_entry: missing p->p_aioinfo");
318 
319 	while (aiocbe->jobstate == JOBST_JOBRUNNING) {
320 		aiocbe->jobflags |= AIOCBLIST_RUNDOWN;
321 		tsleep(aiocbe, 0, "jobwai", 0);
322 	}
323 	if (aiocbe->bp == NULL) {
324 		if (ki->kaio_queue_count <= 0)
325 			panic("aio_free_entry: process queue size <= 0");
326 		if (num_queue_count <= 0)
327 			panic("aio_free_entry: system wide queue size <= 0");
328 
329 		if (lj) {
330 			lj->lioj_queue_count--;
331 			if (aiocbe->jobflags & AIOCBLIST_DONE)
332 				lj->lioj_queue_finished_count--;
333 		}
334 		ki->kaio_queue_count--;
335 		if (aiocbe->jobflags & AIOCBLIST_DONE)
336 			ki->kaio_queue_finished_count--;
337 		num_queue_count--;
338 	} else {
339 		if (lj) {
340 			lj->lioj_buffer_count--;
341 			if (aiocbe->jobflags & AIOCBLIST_DONE)
342 				lj->lioj_buffer_finished_count--;
343 		}
344 		if (aiocbe->jobflags & AIOCBLIST_DONE)
345 			ki->kaio_buffer_finished_count--;
346 		ki->kaio_buffer_count--;
347 		num_buf_aio--;
348 	}
349 
350 	/* aiocbe is going away, we need to destroy any knotes */
351 	/* XXX lwp knote wants a thread, but only cares about the process */
352 	knote_remove(FIRST_LWP_IN_PROC(p)->lwp_thread, &aiocbe->klist);
353 
354 	if ((ki->kaio_flags & KAIO_WAKEUP) || ((ki->kaio_flags & KAIO_RUNDOWN)
355 	    && ((ki->kaio_buffer_count == 0) && (ki->kaio_queue_count == 0)))) {
356 		ki->kaio_flags &= ~KAIO_WAKEUP;
357 		wakeup(p);
358 	}
359 
360 	if (aiocbe->jobstate == JOBST_JOBQBUF) {
361 		if ((error = aio_fphysio(aiocbe)) != 0)
362 			return error;
363 		if (aiocbe->jobstate != JOBST_JOBBFINISHED)
364 			panic("aio_free_entry: invalid physio finish-up state");
365 		crit_enter();
366 		TAILQ_REMOVE(&ki->kaio_bufdone, aiocbe, plist);
367 		crit_exit();
368 	} else if (aiocbe->jobstate == JOBST_JOBQGLOBAL) {
369 		crit_enter();
370 		TAILQ_REMOVE(&aio_jobs, aiocbe, list);
371 		TAILQ_REMOVE(&ki->kaio_jobqueue, aiocbe, plist);
372 		crit_exit();
373 	} else if (aiocbe->jobstate == JOBST_JOBFINISHED)
374 		TAILQ_REMOVE(&ki->kaio_jobdone, aiocbe, plist);
375 	else if (aiocbe->jobstate == JOBST_JOBBFINISHED) {
376 		crit_enter();
377 		TAILQ_REMOVE(&ki->kaio_bufdone, aiocbe, plist);
378 		crit_exit();
379 		if (aiocbe->bp) {
380 			vunmapbuf(aiocbe->bp);
381 			relpbuf(aiocbe->bp, NULL);
382 			aiocbe->bp = NULL;
383 		}
384 	}
385 	if (lj && (lj->lioj_buffer_count == 0) && (lj->lioj_queue_count == 0)) {
386 		TAILQ_REMOVE(&ki->kaio_liojoblist, lj, lioj_list);
387 		zfree(aiolio_zone, lj);
388 	}
389 	aiocbe->jobstate = JOBST_NULL;
390 	callout_stop(&aiocbe->timeout);
391 	fdrop(aiocbe->fd_file);
392 	TAILQ_INSERT_HEAD(&aio_freejobs, aiocbe, list);
393 	return 0;
394 }
395 #endif /* VFS_AIO */
396 
397 /*
398  * Rundown the jobs for a given process.
399  */
400 void
401 aio_proc_rundown(struct proc *p)
402 {
403 #ifndef VFS_AIO
404 	return;
405 #else
406 	struct kaioinfo *ki;
407 	struct aio_liojob *lj, *ljn;
408 	struct aiocblist *aiocbe, *aiocbn;
409 	struct file *fp;
410 	struct socket *so;
411 
412 	ki = p->p_aioinfo;
413 	if (ki == NULL)
414 		return;
415 
416 	ki->kaio_flags |= LIOJ_SIGNAL_POSTED;
417 	while ((ki->kaio_active_count > 0) || (ki->kaio_buffer_count >
418 	    ki->kaio_buffer_finished_count)) {
419 		ki->kaio_flags |= KAIO_RUNDOWN;
420 		if (tsleep(p, 0, "kaiowt", aiod_timeout))
421 			break;
422 	}
423 
424 	/*
425 	 * Move any aio ops that are waiting on socket I/O to the normal job
426 	 * queues so they are cleaned up with any others.
427 	 */
428 	crit_enter();
429 	for (aiocbe = TAILQ_FIRST(&ki->kaio_sockqueue); aiocbe; aiocbe =
430 	    aiocbn) {
431 		aiocbn = TAILQ_NEXT(aiocbe, plist);
432 		fp = aiocbe->fd_file;
433 		if (fp != NULL) {
434 			so = (struct socket *)fp->f_data;
435 			TAILQ_REMOVE(&so->so_aiojobq, aiocbe, list);
436 			if (TAILQ_EMPTY(&so->so_aiojobq)) {
437 				so->so_snd.ssb_flags &= ~SSB_AIO;
438 				so->so_rcv.ssb_flags &= ~SSB_AIO;
439 			}
440 		}
441 		TAILQ_REMOVE(&ki->kaio_sockqueue, aiocbe, plist);
442 		TAILQ_INSERT_HEAD(&aio_jobs, aiocbe, list);
443 		TAILQ_INSERT_HEAD(&ki->kaio_jobqueue, aiocbe, plist);
444 	}
445 	crit_exit();
446 
447 restart1:
448 	for (aiocbe = TAILQ_FIRST(&ki->kaio_jobdone); aiocbe; aiocbe = aiocbn) {
449 		aiocbn = TAILQ_NEXT(aiocbe, plist);
450 		if (aio_free_entry(aiocbe))
451 			goto restart1;
452 	}
453 
454 restart2:
455 	for (aiocbe = TAILQ_FIRST(&ki->kaio_jobqueue); aiocbe; aiocbe =
456 	    aiocbn) {
457 		aiocbn = TAILQ_NEXT(aiocbe, plist);
458 		if (aio_free_entry(aiocbe))
459 			goto restart2;
460 	}
461 
462 restart3:
463 	crit_enter();
464 	while (TAILQ_FIRST(&ki->kaio_bufqueue)) {
465 		ki->kaio_flags |= KAIO_WAKEUP;
466 		tsleep(p, 0, "aioprn", 0);
467 		crit_exit();
468 		goto restart3;
469 	}
470 	crit_exit();
471 
472 restart4:
473 	crit_enter();
474 	for (aiocbe = TAILQ_FIRST(&ki->kaio_bufdone); aiocbe; aiocbe = aiocbn) {
475 		aiocbn = TAILQ_NEXT(aiocbe, plist);
476 		if (aio_free_entry(aiocbe)) {
477 			crit_exit();
478 			goto restart4;
479 		}
480 	}
481 	crit_exit();
482 
483         /*
484          * If we've slept, jobs might have moved from one queue to another.
485          * Retry rundown if we didn't manage to empty the queues.
486          */
487         if (TAILQ_FIRST(&ki->kaio_jobdone) != NULL ||
488 	    TAILQ_FIRST(&ki->kaio_jobqueue) != NULL ||
489 	    TAILQ_FIRST(&ki->kaio_bufqueue) != NULL ||
490 	    TAILQ_FIRST(&ki->kaio_bufdone) != NULL)
491 		goto restart1;
492 
493 	for (lj = TAILQ_FIRST(&ki->kaio_liojoblist); lj; lj = ljn) {
494 		ljn = TAILQ_NEXT(lj, lioj_list);
495 		if ((lj->lioj_buffer_count == 0) && (lj->lioj_queue_count ==
496 		    0)) {
497 			TAILQ_REMOVE(&ki->kaio_liojoblist, lj, lioj_list);
498 			zfree(aiolio_zone, lj);
499 		} else {
500 #ifdef DIAGNOSTIC
501 			kprintf("LIO job not cleaned up: B:%d, BF:%d, Q:%d, "
502 			    "QF:%d\n", lj->lioj_buffer_count,
503 			    lj->lioj_buffer_finished_count,
504 			    lj->lioj_queue_count,
505 			    lj->lioj_queue_finished_count);
506 #endif
507 		}
508 	}
509 
510 	zfree(kaio_zone, ki);
511 	p->p_aioinfo = NULL;
512 #endif /* VFS_AIO */
513 }
514 
515 #ifdef VFS_AIO
516 /*
517  * Select a job to run (called by an AIO daemon).
518  */
519 static struct aiocblist *
520 aio_selectjob(struct aioproclist *aiop)
521 {
522 	struct aiocblist *aiocbe;
523 	struct kaioinfo *ki;
524 	struct proc *userp;
525 
526 	crit_enter();
527 	for (aiocbe = TAILQ_FIRST(&aio_jobs); aiocbe; aiocbe =
528 	    TAILQ_NEXT(aiocbe, list)) {
529 		userp = aiocbe->userproc;
530 		ki = userp->p_aioinfo;
531 
532 		if (ki->kaio_active_count < ki->kaio_maxactive_count) {
533 			TAILQ_REMOVE(&aio_jobs, aiocbe, list);
534 			crit_exit();
535 			return aiocbe;
536 		}
537 	}
538 	crit_exit();
539 
540 	return NULL;
541 }
542 
543 /*
544  * The AIO processing activity.  This is the code that does the I/O request for
545  * the non-physio version of the operations.  The normal vn operations are used,
546  * and this code should work in all instances for every type of file, including
547  * pipes, sockets, fifos, and regular files.
548  */
549 static void
550 aio_process(struct aiocblist *aiocbe)
551 {
552 	struct thread *mytd;
553 	struct aiocb *cb;
554 	struct file *fp;
555 	struct uio auio;
556 	struct iovec aiov;
557 	int cnt;
558 	int error;
559 	int oublock_st, oublock_end;
560 	int inblock_st, inblock_end;
561 
562 	mytd = curthread;
563 	cb = &aiocbe->uaiocb;
564 	fp = aiocbe->fd_file;
565 
566 	aiov.iov_base = (void *)(uintptr_t)cb->aio_buf;
567 	aiov.iov_len = cb->aio_nbytes;
568 
569 	auio.uio_iov = &aiov;
570 	auio.uio_iovcnt = 1;
571 	auio.uio_offset = cb->aio_offset;
572 	auio.uio_resid = cb->aio_nbytes;
573 	cnt = cb->aio_nbytes;
574 	auio.uio_segflg = UIO_USERSPACE;
575 	auio.uio_td = mytd;
576 
577 	inblock_st = mytd->td_lwp->lwp_ru.ru_inblock;
578 	oublock_st = mytd->td_lwp->lwp_ru.ru_oublock;
579 	/*
580 	 * _aio_aqueue() acquires a reference to the file that is
581 	 * released in aio_free_entry().
582 	 */
583 	if (cb->aio_lio_opcode == LIO_READ) {
584 		auio.uio_rw = UIO_READ;
585 		error = fo_read(fp, &auio, fp->f_cred, O_FOFFSET);
586 	} else {
587 		auio.uio_rw = UIO_WRITE;
588 		error = fo_write(fp, &auio, fp->f_cred, O_FOFFSET);
589 	}
590 	inblock_end = mytd->td_lwp->lwp_ru.ru_inblock;
591 	oublock_end = mytd->td_lwp->lwp_ru.ru_oublock;
592 
593 	aiocbe->inputcharge = inblock_end - inblock_st;
594 	aiocbe->outputcharge = oublock_end - oublock_st;
595 
596 	if ((error) && (auio.uio_resid != cnt)) {
597 		if (error == ERESTART || error == EINTR || error == EWOULDBLOCK)
598 			error = 0;
599 		if ((error == EPIPE) && (cb->aio_lio_opcode == LIO_WRITE))
600 			ksignal(aiocbe->userproc, SIGPIPE);
601 	}
602 
603 	cnt -= auio.uio_resid;
604 	cb->_aiocb_private.error = error;
605 	cb->_aiocb_private.status = cnt;
606 }
607 
608 /*
609  * The AIO daemon, most of the actual work is done in aio_process,
610  * but the setup (and address space mgmt) is done in this routine.
611  *
612  * The MP lock is held on entry.
613  */
614 static void
615 aio_daemon(void *uproc, struct trapframe *frame)
616 {
617 	struct aio_liojob *lj;
618 	struct aiocb *cb;
619 	struct aiocblist *aiocbe;
620 	struct aioproclist *aiop;
621 	struct kaioinfo *ki;
622 	struct proc *mycp, *userp;
623 	struct vmspace *curvm;
624 	struct lwp *mylwp;
625 	struct ucred *cr;
626 
627 	mylwp = curthread->td_lwp;
628 	mycp = mylwp->lwp_proc;
629 
630 	if (mycp->p_textvp) {
631 		vrele(mycp->p_textvp);
632 		mycp->p_textvp = NULL;
633 	}
634 
635 	/*
636 	 * Allocate and ready the aio control info.  There is one aiop structure
637 	 * per daemon.
638 	 */
639 	aiop = zalloc(aiop_zone);
640 	aiop->aioproc = mycp;
641 	aiop->aioprocflags |= AIOP_FREE;
642 
643 	crit_enter();
644 
645 	/*
646 	 * Place thread (lightweight process) onto the AIO free thread list.
647 	 */
648 	if (TAILQ_EMPTY(&aio_freeproc))
649 		wakeup(&aio_freeproc);
650 	TAILQ_INSERT_HEAD(&aio_freeproc, aiop, list);
651 
652 	crit_exit();
653 
654 	/* Make up a name for the daemon. */
655 	strcpy(mycp->p_comm, "aiod");
656 
657 	/*
658 	 * Get rid of our current filedescriptors.  AIOD's don't need any
659 	 * filedescriptors, except as temporarily inherited from the client.
660 	 * Credentials are also cloned, and made equivalent to "root".
661 	 */
662 	fdfree(mycp);
663 	mycp->p_fd = NULL;
664 	cr = cratom(&mycp->p_ucred);
665 	cr->cr_uid = 0;
666 	uireplace(&cr->cr_uidinfo, uifind(0));
667 	cr->cr_ngroups = 1;
668 	cr->cr_groups[0] = 1;
669 
670 	/* The daemon resides in its own pgrp. */
671 	enterpgrp(mycp, mycp->p_pid, 1);
672 
673 	/* Mark special process type. */
674 	mycp->p_flag |= P_SYSTEM | P_KTHREADP;
675 
676 	/*
677 	 * Wakeup parent process.  (Parent sleeps to keep from blasting away
678 	 * and creating too many daemons.)
679 	 */
680 	wakeup(mycp);
681 	curvm = NULL;
682 
683 	for (;;) {
684 		/*
685 		 * Take daemon off of free queue
686 		 */
687 		if (aiop->aioprocflags & AIOP_FREE) {
688 			crit_enter();
689 			TAILQ_REMOVE(&aio_freeproc, aiop, list);
690 			TAILQ_INSERT_TAIL(&aio_activeproc, aiop, list);
691 			aiop->aioprocflags &= ~AIOP_FREE;
692 			crit_exit();
693 		}
694 		aiop->aioprocflags &= ~AIOP_SCHED;
695 
696 		/*
697 		 * Check for jobs.
698 		 */
699 		while ((aiocbe = aio_selectjob(aiop)) != NULL) {
700 			cb = &aiocbe->uaiocb;
701 			userp = aiocbe->userproc;
702 
703 			aiocbe->jobstate = JOBST_JOBRUNNING;
704 
705 			/*
706 			 * Connect to process address space for user program.
707 			 */
708 			if (curvm != userp->p_vmspace) {
709 				pmap_setlwpvm(mylwp, userp->p_vmspace);
710 				if (curvm)
711 					sysref_put(&curvm->vm_sysref);
712 				curvm = userp->p_vmspace;
713 				sysref_get(&curvm->vm_sysref);
714 			}
715 
716 			ki = userp->p_aioinfo;
717 			lj = aiocbe->lio;
718 
719 			/* Account for currently active jobs. */
720 			ki->kaio_active_count++;
721 
722 			/* Do the I/O function. */
723 			aio_process(aiocbe);
724 
725 			/* Decrement the active job count. */
726 			ki->kaio_active_count--;
727 
728 			/*
729 			 * Increment the completion count for wakeup/signal
730 			 * comparisons.
731 			 */
732 			aiocbe->jobflags |= AIOCBLIST_DONE;
733 			ki->kaio_queue_finished_count++;
734 			if (lj)
735 				lj->lioj_queue_finished_count++;
736 			if ((ki->kaio_flags & KAIO_WAKEUP) || ((ki->kaio_flags
737 			    & KAIO_RUNDOWN) && (ki->kaio_active_count == 0))) {
738 				ki->kaio_flags &= ~KAIO_WAKEUP;
739 				wakeup(userp);
740 			}
741 
742 			crit_enter();
743 			if (lj && (lj->lioj_flags &
744 			    (LIOJ_SIGNAL|LIOJ_SIGNAL_POSTED)) == LIOJ_SIGNAL) {
745 				if ((lj->lioj_queue_finished_count ==
746 				    lj->lioj_queue_count) &&
747 				    (lj->lioj_buffer_finished_count ==
748 				    lj->lioj_buffer_count)) {
749 						ksignal(userp,
750 						    lj->lioj_signal.sigev_signo);
751 						lj->lioj_flags |=
752 						    LIOJ_SIGNAL_POSTED;
753 				}
754 			}
755 			crit_exit();
756 
757 			aiocbe->jobstate = JOBST_JOBFINISHED;
758 
759 			crit_enter();
760 			TAILQ_REMOVE(&ki->kaio_jobqueue, aiocbe, plist);
761 			TAILQ_INSERT_TAIL(&ki->kaio_jobdone, aiocbe, plist);
762 			crit_exit();
763 			KNOTE(&aiocbe->klist, 0);
764 
765 			if (aiocbe->jobflags & AIOCBLIST_RUNDOWN) {
766 				wakeup(aiocbe);
767 				aiocbe->jobflags &= ~AIOCBLIST_RUNDOWN;
768 			}
769 
770 			if (cb->aio_sigevent.sigev_notify == SIGEV_SIGNAL) {
771 				ksignal(userp, cb->aio_sigevent.sigev_signo);
772 			}
773 		}
774 
775 		/*
776 		 * Disconnect from user address space.
777 		 */
778 		if (curvm) {
779 			/* swap our original address space back in */
780 			pmap_setlwpvm(mylwp, mycp->p_vmspace);
781 			sysref_put(&curvm->vm_sysref);
782 			curvm = NULL;
783 		}
784 
785 		/*
786 		 * If we are the first to be put onto the free queue, wakeup
787 		 * anyone waiting for a daemon.
788 		 */
789 		crit_enter();
790 		TAILQ_REMOVE(&aio_activeproc, aiop, list);
791 		if (TAILQ_EMPTY(&aio_freeproc))
792 			wakeup(&aio_freeproc);
793 		TAILQ_INSERT_HEAD(&aio_freeproc, aiop, list);
794 		aiop->aioprocflags |= AIOP_FREE;
795 		crit_exit();
796 
797 		/*
798 		 * If daemon is inactive for a long time, allow it to exit,
799 		 * thereby freeing resources.
800 		 */
801 		if (((aiop->aioprocflags & AIOP_SCHED) == 0) && tsleep(mycp,
802 		    0, "aiordy", aiod_lifetime)) {
803 			crit_enter();
804 			if (TAILQ_EMPTY(&aio_jobs)) {
805 				if ((aiop->aioprocflags & AIOP_FREE) &&
806 				    (num_aio_procs > target_aio_procs)) {
807 					TAILQ_REMOVE(&aio_freeproc, aiop, list);
808 					crit_exit();
809 					zfree(aiop_zone, aiop);
810 					num_aio_procs--;
811 #ifdef DIAGNOSTIC
812 					if (mycp->p_vmspace->vm_sysref.refcnt <= 1) {
813 						kprintf("AIOD: bad vm refcnt for"
814 						    " exiting daemon: %d\n",
815 						    mycp->p_vmspace->vm_sysref.refcnt);
816 					}
817 #endif
818 					exit1(0);
819 				}
820 			}
821 			crit_exit();
822 		}
823 	}
824 }
825 
826 /*
827  * Create a new AIO daemon.  This is mostly a kernel-thread fork routine.  The
828  * AIO daemon modifies its environment itself.
829  */
830 static int
831 aio_newproc(void)
832 {
833 	int error;
834 	struct lwp *lp, *nlp;
835 	struct proc *np;
836 
837 	lp = &lwp0;
838 	error = fork1(lp, RFPROC|RFMEM|RFNOWAIT, &np);
839 	if (error)
840 		return error;
841 	nlp = ONLY_LWP_IN_PROC(np);
842 	cpu_set_fork_handler(nlp, aio_daemon, curproc);
843 	start_forked_proc(lp, np);
844 
845 	/*
846 	 * Wait until daemon is started, but continue on just in case to
847 	 * handle error conditions.
848 	 */
849 	error = tsleep(np, 0, "aiosta", aiod_timeout);
850 	num_aio_procs++;
851 
852 	return error;
853 }
854 
855 /*
856  * Try the high-performance, low-overhead physio method for eligible
857  * VCHR devices.  This method doesn't use an aio helper thread, and
858  * thus has very low overhead.
859  *
860  * Assumes that the caller, _aio_aqueue(), has incremented the file
861  * structure's reference count, preventing its deallocation for the
862  * duration of this call.
863  */
864 static int
865 aio_qphysio(struct proc *p, struct aiocblist *aiocbe)
866 {
867 	int error;
868 	struct aiocb *cb;
869 	struct file *fp;
870 	struct buf *bp;
871 	struct vnode *vp;
872 	struct kaioinfo *ki;
873 	struct aio_liojob *lj;
874 	int notify;
875 
876 	cb = &aiocbe->uaiocb;
877 	fp = aiocbe->fd_file;
878 
879 	if (fp->f_type != DTYPE_VNODE)
880 		return (-1);
881 
882 	vp = (struct vnode *)fp->f_data;
883 
884 	/*
885 	 * If its not a disk, we don't want to return a positive error.
886 	 * It causes the aio code to not fall through to try the thread
887 	 * way when you're talking to a regular file.
888 	 */
889 	if (!vn_isdisk(vp, &error)) {
890 		if (error == ENOTBLK)
891 			return (-1);
892 		else
893 			return (error);
894 	}
895 
896  	if (cb->aio_nbytes % vp->v_rdev->si_bsize_phys)
897 		return (-1);
898 
899 	if (cb->aio_nbytes >
900 	    MAXPHYS - (((vm_offset_t) cb->aio_buf) & PAGE_MASK))
901 		return (-1);
902 
903 	ki = p->p_aioinfo;
904 	if (ki->kaio_buffer_count >= ki->kaio_ballowed_count)
905 		return (-1);
906 
907 	ki->kaio_buffer_count++;
908 
909 	lj = aiocbe->lio;
910 	if (lj)
911 		lj->lioj_buffer_count++;
912 
913 	/* Create and build a buffer header for a transfer. */
914 	bp = getpbuf(NULL);
915 	BUF_KERNPROC(bp);
916 
917 	/*
918 	 * Get a copy of the kva from the physical buffer.
919 	 */
920 	bp->b_bio1.bio_caller_info1.ptr = p;
921 	error = 0;
922 
923 	bp->b_cmd = (cb->aio_lio_opcode == LIO_WRITE) ?
924 		    BUF_CMD_WRITE : BUF_CMD_READ;
925 	bp->b_bio1.bio_done = aio_physwakeup;
926 	bp->b_bio1.bio_offset = cb->aio_offset;
927 
928 	/* Bring buffer into kernel space. */
929 	if (vmapbuf(bp, __DEVOLATILE(char *, cb->aio_buf), cb->aio_nbytes) < 0) {
930 		error = EFAULT;
931 		goto doerror;
932 	}
933 
934 	crit_enter();
935 
936 	aiocbe->bp = bp;
937 	bp->b_bio1.bio_caller_info2.ptr = aiocbe;
938 	TAILQ_INSERT_TAIL(&aio_bufjobs, aiocbe, list);
939 	TAILQ_INSERT_TAIL(&ki->kaio_bufqueue, aiocbe, plist);
940 	aiocbe->jobstate = JOBST_JOBQBUF;
941 	cb->_aiocb_private.status = cb->aio_nbytes;
942 	num_buf_aio++;
943 	bp->b_error = 0;
944 
945 	crit_exit();
946 
947 	/*
948 	 * Perform the transfer.  vn_strategy must be used even though we
949 	 * know we have a device in order to deal with requests which exceed
950 	 * device DMA limitations.
951 	 */
952 	vn_strategy(vp, &bp->b_bio1);
953 
954 	notify = 0;
955 	crit_enter();
956 
957 	/*
958 	 * If we had an error invoking the request, or an error in processing
959 	 * the request before we have returned, we process it as an error in
960 	 * transfer.  Note that such an I/O error is not indicated immediately,
961 	 * but is returned using the aio_error mechanism.  In this case,
962 	 * aio_suspend will return immediately.
963 	 */
964 	if (bp->b_error || (bp->b_flags & B_ERROR)) {
965 		struct aiocb *job = aiocbe->uuaiocb;
966 
967 		aiocbe->uaiocb._aiocb_private.status = 0;
968 		suword(&job->_aiocb_private.status, 0);
969 		aiocbe->uaiocb._aiocb_private.error = bp->b_error;
970 		suword(&job->_aiocb_private.error, bp->b_error);
971 
972 		ki->kaio_buffer_finished_count++;
973 
974 		if (aiocbe->jobstate != JOBST_JOBBFINISHED) {
975 			aiocbe->jobstate = JOBST_JOBBFINISHED;
976 			aiocbe->jobflags |= AIOCBLIST_DONE;
977 			TAILQ_REMOVE(&aio_bufjobs, aiocbe, list);
978 			TAILQ_REMOVE(&ki->kaio_bufqueue, aiocbe, plist);
979 			TAILQ_INSERT_TAIL(&ki->kaio_bufdone, aiocbe, plist);
980 			notify = 1;
981 		}
982 	}
983 	crit_exit();
984 	if (notify)
985 		KNOTE(&aiocbe->klist, 0);
986 	return 0;
987 
988 doerror:
989 	ki->kaio_buffer_count--;
990 	if (lj)
991 		lj->lioj_buffer_count--;
992 	aiocbe->bp = NULL;
993 	relpbuf(bp, NULL);
994 	return error;
995 }
996 
997 /*
998  * This waits/tests physio completion.
999  */
1000 static int
1001 aio_fphysio(struct aiocblist *iocb)
1002 {
1003 	struct buf *bp;
1004 	int error;
1005 
1006 	bp = iocb->bp;
1007 
1008 	crit_enter();
1009 	while (bp->b_cmd != BUF_CMD_DONE) {
1010 		if (tsleep(bp, 0, "physstr", aiod_timeout)) {
1011 			if (bp->b_cmd != BUF_CMD_DONE) {
1012 				crit_exit();
1013 				return EINPROGRESS;
1014 			} else {
1015 				break;
1016 			}
1017 		}
1018 	}
1019 	crit_exit();
1020 
1021 	/* Release mapping into kernel space. */
1022 	vunmapbuf(bp);
1023 	iocb->bp = 0;
1024 
1025 	error = 0;
1026 
1027 	/* Check for an error. */
1028 	if (bp->b_flags & B_ERROR)
1029 		error = bp->b_error;
1030 
1031 	relpbuf(bp, NULL);
1032 	return (error);
1033 }
1034 #endif /* VFS_AIO */
1035 
1036 /*
1037  * Wake up aio requests that may be serviceable now.
1038  */
1039 void
1040 aio_swake(struct socket *so, struct signalsockbuf *ssb)
1041 {
1042 #ifndef VFS_AIO
1043 	return;
1044 #else
1045 	struct aiocblist *cb,*cbn;
1046 	struct proc *p;
1047 	struct kaioinfo *ki = NULL;
1048 	int opcode, wakecount = 0;
1049 	struct aioproclist *aiop;
1050 
1051 	if (ssb == &so->so_snd) {
1052 		opcode = LIO_WRITE;
1053 		so->so_snd.ssb_flags &= ~SSB_AIO;
1054 	} else {
1055 		opcode = LIO_READ;
1056 		so->so_rcv.ssb_flags &= ~SSB_AIO;
1057 	}
1058 
1059 	for (cb = TAILQ_FIRST(&so->so_aiojobq); cb; cb = cbn) {
1060 		cbn = TAILQ_NEXT(cb, list);
1061 		if (opcode == cb->uaiocb.aio_lio_opcode) {
1062 			p = cb->userproc;
1063 			ki = p->p_aioinfo;
1064 			TAILQ_REMOVE(&so->so_aiojobq, cb, list);
1065 			TAILQ_REMOVE(&ki->kaio_sockqueue, cb, plist);
1066 			TAILQ_INSERT_TAIL(&aio_jobs, cb, list);
1067 			TAILQ_INSERT_TAIL(&ki->kaio_jobqueue, cb, plist);
1068 			wakecount++;
1069 			if (cb->jobstate != JOBST_JOBQGLOBAL)
1070 				panic("invalid queue value");
1071 		}
1072 	}
1073 
1074 	while (wakecount--) {
1075 		if ((aiop = TAILQ_FIRST(&aio_freeproc)) != 0) {
1076 			TAILQ_REMOVE(&aio_freeproc, aiop, list);
1077 			TAILQ_INSERT_TAIL(&aio_activeproc, aiop, list);
1078 			aiop->aioprocflags &= ~AIOP_FREE;
1079 			wakeup(aiop->aioproc);
1080 		}
1081 	}
1082 #endif /* VFS_AIO */
1083 }
1084 
1085 #ifdef VFS_AIO
1086 /*
1087  * Queue a new AIO request.  Choosing either the threaded or direct physio VCHR
1088  * technique is done in this code.
1089  */
1090 static int
1091 _aio_aqueue(struct aiocb *job, struct aio_liojob *lj, int type)
1092 {
1093 	struct proc *p = curproc;
1094 	struct filedesc *fdp;
1095 	struct file *fp;
1096 	unsigned int fd;
1097 	struct socket *so;
1098 	int error;
1099 	int opcode, user_opcode;
1100 	struct aiocblist *aiocbe;
1101 	struct aioproclist *aiop;
1102 	struct kaioinfo *ki;
1103 	struct kevent kev;
1104 	struct kqueue *kq;
1105 	struct file *kq_fp;
1106 
1107 	if ((aiocbe = TAILQ_FIRST(&aio_freejobs)) != NULL)
1108 		TAILQ_REMOVE(&aio_freejobs, aiocbe, list);
1109 	else
1110 		aiocbe = zalloc (aiocb_zone);
1111 
1112 	aiocbe->inputcharge = 0;
1113 	aiocbe->outputcharge = 0;
1114 	callout_init(&aiocbe->timeout);
1115 	SLIST_INIT(&aiocbe->klist);
1116 
1117 	suword(&job->_aiocb_private.status, -1);
1118 	suword(&job->_aiocb_private.error, 0);
1119 	suword(&job->_aiocb_private.kernelinfo, -1);
1120 
1121 	error = copyin(job, &aiocbe->uaiocb, sizeof(aiocbe->uaiocb));
1122 	if (error) {
1123 		suword(&job->_aiocb_private.error, error);
1124 		TAILQ_INSERT_HEAD(&aio_freejobs, aiocbe, list);
1125 		return error;
1126 	}
1127 	if (aiocbe->uaiocb.aio_sigevent.sigev_notify == SIGEV_SIGNAL &&
1128 	    !_SIG_VALID(aiocbe->uaiocb.aio_sigevent.sigev_signo)) {
1129 		TAILQ_INSERT_HEAD(&aio_freejobs, aiocbe, list);
1130 		return EINVAL;
1131 	}
1132 
1133 	/* Save userspace address of the job info. */
1134 	aiocbe->uuaiocb = job;
1135 
1136 	/* Get the opcode. */
1137 	user_opcode = aiocbe->uaiocb.aio_lio_opcode;
1138 	if (type != LIO_NOP)
1139 		aiocbe->uaiocb.aio_lio_opcode = type;
1140 	opcode = aiocbe->uaiocb.aio_lio_opcode;
1141 
1142 	/* Get the fd info for process. */
1143 	fdp = p->p_fd;
1144 
1145 	/*
1146 	 * Range check file descriptor.
1147 	 */
1148 	fd = aiocbe->uaiocb.aio_fildes;
1149 	if (fd >= fdp->fd_nfiles) {
1150 		TAILQ_INSERT_HEAD(&aio_freejobs, aiocbe, list);
1151 		if (type == 0)
1152 			suword(&job->_aiocb_private.error, EBADF);
1153 		return EBADF;
1154 	}
1155 
1156 	fp = aiocbe->fd_file = fdp->fd_files[fd].fp;
1157 	if ((fp == NULL) || ((opcode == LIO_WRITE) && ((fp->f_flag & FWRITE) ==
1158 	    0))) {
1159 		TAILQ_INSERT_HEAD(&aio_freejobs, aiocbe, list);
1160 		if (type == 0)
1161 			suword(&job->_aiocb_private.error, EBADF);
1162 		return EBADF;
1163 	}
1164 	fhold(fp);
1165 
1166 	if (aiocbe->uaiocb.aio_offset == -1LL) {
1167 		error = EINVAL;
1168 		goto aqueue_fail;
1169 	}
1170 	error = suword(&job->_aiocb_private.kernelinfo, jobrefid);
1171 	if (error) {
1172 		error = EINVAL;
1173 		goto aqueue_fail;
1174 	}
1175 	aiocbe->uaiocb._aiocb_private.kernelinfo = (void *)(intptr_t)jobrefid;
1176 	if (jobrefid == LONG_MAX)
1177 		jobrefid = 1;
1178 	else
1179 		jobrefid++;
1180 
1181 	if (opcode == LIO_NOP) {
1182 		fdrop(fp);
1183 		TAILQ_INSERT_HEAD(&aio_freejobs, aiocbe, list);
1184 		if (type == 0) {
1185 			suword(&job->_aiocb_private.error, 0);
1186 			suword(&job->_aiocb_private.status, 0);
1187 			suword(&job->_aiocb_private.kernelinfo, 0);
1188 		}
1189 		return 0;
1190 	}
1191 	if ((opcode != LIO_READ) && (opcode != LIO_WRITE)) {
1192 		if (type == 0)
1193 			suword(&job->_aiocb_private.status, 0);
1194 		error = EINVAL;
1195 		goto aqueue_fail;
1196 	}
1197 
1198 	if (aiocbe->uaiocb.aio_sigevent.sigev_notify == SIGEV_KEVENT) {
1199 		kev.ident = aiocbe->uaiocb.aio_sigevent.sigev_notify_kqueue;
1200 		kev.udata = aiocbe->uaiocb.aio_sigevent.sigev_value.sigval_ptr;
1201 	}
1202 	else {
1203 		/*
1204 		 * This method for requesting kevent-based notification won't
1205 		 * work on the alpha, since we're passing in a pointer
1206 		 * via aio_lio_opcode, which is an int.  Use the SIGEV_KEVENT-
1207 		 * based method instead.
1208 		 */
1209 		if (user_opcode == LIO_NOP || user_opcode == LIO_READ ||
1210 		    user_opcode == LIO_WRITE)
1211 			goto no_kqueue;
1212 
1213 		error = copyin((struct kevent *)(uintptr_t)user_opcode,
1214 		    &kev, sizeof(kev));
1215 		if (error)
1216 			goto aqueue_fail;
1217 	}
1218 	if ((u_int)kev.ident >= fdp->fd_nfiles ||
1219 	    (kq_fp = fdp->fd_files[kev.ident].fp) == NULL ||
1220 	    (kq_fp->f_type != DTYPE_KQUEUE)) {
1221 		error = EBADF;
1222 		goto aqueue_fail;
1223 	}
1224 	kq = (struct kqueue *)kq_fp->f_data;
1225 	kev.ident = (uintptr_t)aiocbe->uuaiocb;
1226 	kev.filter = EVFILT_AIO;
1227 	kev.flags = EV_ADD | EV_ENABLE | EV_FLAG1;
1228 	kev.data = (intptr_t)aiocbe;
1229 	/* XXX lwp kqueue_register takes a thread, but only uses its proc */
1230 	error = kqueue_register(kq, &kev, FIRST_LWP_IN_PROC(p)->lwp_thread);
1231 aqueue_fail:
1232 	if (error) {
1233 		fdrop(fp);
1234 		TAILQ_INSERT_HEAD(&aio_freejobs, aiocbe, list);
1235 		if (type == 0)
1236 			suword(&job->_aiocb_private.error, error);
1237 		goto done;
1238 	}
1239 no_kqueue:
1240 
1241 	suword(&job->_aiocb_private.error, EINPROGRESS);
1242 	aiocbe->uaiocb._aiocb_private.error = EINPROGRESS;
1243 	aiocbe->userproc = p;
1244 	aiocbe->jobflags = 0;
1245 	aiocbe->lio = lj;
1246 	ki = p->p_aioinfo;
1247 
1248 	if (fp->f_type == DTYPE_SOCKET) {
1249 		/*
1250 		 * Alternate queueing for socket ops: Reach down into the
1251 		 * descriptor to get the socket data.  Then check to see if the
1252 		 * socket is ready to be read or written (based on the requested
1253 		 * operation).
1254 		 *
1255 		 * If it is not ready for io, then queue the aiocbe on the
1256 		 * socket, and set the flags so we get a call when ssb_notify()
1257 		 * happens.
1258 		 */
1259 		so = (struct socket *)fp->f_data;
1260 		crit_enter();
1261 		if (((opcode == LIO_READ) && (!soreadable(so))) || ((opcode ==
1262 		    LIO_WRITE) && (!sowriteable(so)))) {
1263 			TAILQ_INSERT_TAIL(&so->so_aiojobq, aiocbe, list);
1264 			TAILQ_INSERT_TAIL(&ki->kaio_sockqueue, aiocbe, plist);
1265 			if (opcode == LIO_READ)
1266 				so->so_rcv.ssb_flags |= SSB_AIO;
1267 			else
1268 				so->so_snd.ssb_flags |= SSB_AIO;
1269 			aiocbe->jobstate = JOBST_JOBQGLOBAL; /* XXX */
1270 			ki->kaio_queue_count++;
1271 			num_queue_count++;
1272 			crit_exit();
1273 			error = 0;
1274 			goto done;
1275 		}
1276 		crit_exit();
1277 	}
1278 
1279 	if ((error = aio_qphysio(p, aiocbe)) == 0)
1280 		goto done;
1281 	if (error > 0) {
1282 		suword(&job->_aiocb_private.status, 0);
1283 		aiocbe->uaiocb._aiocb_private.error = error;
1284 		suword(&job->_aiocb_private.error, error);
1285 		goto done;
1286 	}
1287 
1288 	/* No buffer for daemon I/O. */
1289 	aiocbe->bp = NULL;
1290 
1291 	ki->kaio_queue_count++;
1292 	if (lj)
1293 		lj->lioj_queue_count++;
1294 	crit_enter();
1295 	TAILQ_INSERT_TAIL(&ki->kaio_jobqueue, aiocbe, plist);
1296 	TAILQ_INSERT_TAIL(&aio_jobs, aiocbe, list);
1297 	crit_exit();
1298 	aiocbe->jobstate = JOBST_JOBQGLOBAL;
1299 
1300 	num_queue_count++;
1301 	error = 0;
1302 
1303 	/*
1304 	 * If we don't have a free AIO process, and we are below our quota, then
1305 	 * start one.  Otherwise, depend on the subsequent I/O completions to
1306 	 * pick-up this job.  If we don't successfully create the new process
1307 	 * (thread) due to resource issues, we return an error for now (EAGAIN),
1308 	 * which is likely not the correct thing to do.
1309 	 */
1310 	crit_enter();
1311 retryproc:
1312 	if ((aiop = TAILQ_FIRST(&aio_freeproc)) != NULL) {
1313 		TAILQ_REMOVE(&aio_freeproc, aiop, list);
1314 		TAILQ_INSERT_TAIL(&aio_activeproc, aiop, list);
1315 		aiop->aioprocflags &= ~AIOP_FREE;
1316 		wakeup(aiop->aioproc);
1317 	} else if (((num_aio_resv_start + num_aio_procs) < max_aio_procs) &&
1318 	    ((ki->kaio_active_count + num_aio_resv_start) <
1319 	    ki->kaio_maxactive_count)) {
1320 		num_aio_resv_start++;
1321 		if ((error = aio_newproc()) == 0) {
1322 			num_aio_resv_start--;
1323 			goto retryproc;
1324 		}
1325 		num_aio_resv_start--;
1326 	}
1327 	crit_exit();
1328 done:
1329 	return error;
1330 }
1331 
1332 /*
1333  * This routine queues an AIO request, checking for quotas.
1334  */
1335 static int
1336 aio_aqueue(struct aiocb *job, int type)
1337 {
1338 	struct proc *p = curproc;
1339 	struct kaioinfo *ki;
1340 
1341 	if (p->p_aioinfo == NULL)
1342 		aio_init_aioinfo(p);
1343 
1344 	if (num_queue_count >= max_queue_count)
1345 		return EAGAIN;
1346 
1347 	ki = p->p_aioinfo;
1348 	if (ki->kaio_queue_count >= ki->kaio_qallowed_count)
1349 		return EAGAIN;
1350 
1351 	return _aio_aqueue(job, NULL, type);
1352 }
1353 #endif /* VFS_AIO */
1354 
1355 /*
1356  * Support the aio_return system call, as a side-effect, kernel resources are
1357  * released.
1358  */
1359 int
1360 sys_aio_return(struct aio_return_args *uap)
1361 {
1362 #ifndef VFS_AIO
1363 	return ENOSYS;
1364 #else
1365 	struct proc *p = curproc;
1366 	struct lwp *lp = curthread->td_lwp;
1367 	long jobref;
1368 	struct aiocblist *cb, *ncb;
1369 	struct aiocb *ujob;
1370 	struct kaioinfo *ki;
1371 
1372 	ki = p->p_aioinfo;
1373 	if (ki == NULL)
1374 		return EINVAL;
1375 
1376 	ujob = uap->aiocbp;
1377 
1378 	jobref = fuword(&ujob->_aiocb_private.kernelinfo);
1379 	if (jobref == -1 || jobref == 0)
1380 		return EINVAL;
1381 
1382 	TAILQ_FOREACH(cb, &ki->kaio_jobdone, plist) {
1383 		if (((intptr_t) cb->uaiocb._aiocb_private.kernelinfo) ==
1384 		    jobref) {
1385 			if (ujob == cb->uuaiocb) {
1386 				uap->sysmsg_result =
1387 				    cb->uaiocb._aiocb_private.status;
1388 			} else
1389 				uap->sysmsg_result = EFAULT;
1390 			if (cb->uaiocb.aio_lio_opcode == LIO_WRITE) {
1391 				lp->lwp_ru.ru_oublock += cb->outputcharge;
1392 				cb->outputcharge = 0;
1393 			} else if (cb->uaiocb.aio_lio_opcode == LIO_READ) {
1394 				lp->lwp_ru.ru_inblock += cb->inputcharge;
1395 				cb->inputcharge = 0;
1396 			}
1397 			aio_free_entry(cb);
1398 			return 0;
1399 		}
1400 	}
1401 	crit_enter();
1402 	for (cb = TAILQ_FIRST(&ki->kaio_bufdone); cb; cb = ncb) {
1403 		ncb = TAILQ_NEXT(cb, plist);
1404 		if (((intptr_t) cb->uaiocb._aiocb_private.kernelinfo)
1405 		    == jobref) {
1406 			crit_exit();
1407 			if (ujob == cb->uuaiocb) {
1408 				uap->sysmsg_result =
1409 				    cb->uaiocb._aiocb_private.status;
1410 			} else
1411 				uap->sysmsg_result = EFAULT;
1412 			aio_free_entry(cb);
1413 			return 0;
1414 		}
1415 	}
1416 	crit_exit();
1417 
1418 	return (EINVAL);
1419 #endif /* VFS_AIO */
1420 }
1421 
1422 /*
1423  * Allow a process to wakeup when any of the I/O requests are completed.
1424  */
1425 int
1426 sys_aio_suspend(struct aio_suspend_args *uap)
1427 {
1428 #ifndef VFS_AIO
1429 	return ENOSYS;
1430 #else
1431 	struct proc *p = curproc;
1432 	struct timeval atv;
1433 	struct timespec ts;
1434 	struct aiocb *const *cbptr, *cbp;
1435 	struct kaioinfo *ki;
1436 	struct aiocblist *cb;
1437 	int i;
1438 	int njoblist;
1439 	int error, timo;
1440 	long *ijoblist;
1441 	struct aiocb **ujoblist;
1442 
1443 	if (uap->nent > AIO_LISTIO_MAX)
1444 		return EINVAL;
1445 
1446 	timo = 0;
1447 	if (uap->timeout) {
1448 		/* Get timespec struct. */
1449 		if ((error = copyin(uap->timeout, &ts, sizeof(ts))) != 0)
1450 			return error;
1451 
1452 		if (ts.tv_nsec < 0 || ts.tv_nsec >= 1000000000)
1453 			return (EINVAL);
1454 
1455 		TIMESPEC_TO_TIMEVAL(&atv, &ts);
1456 		if (itimerfix(&atv))
1457 			return (EINVAL);
1458 		timo = tvtohz_high(&atv);
1459 	}
1460 
1461 	ki = p->p_aioinfo;
1462 	if (ki == NULL)
1463 		return EAGAIN;
1464 
1465 	njoblist = 0;
1466 	ijoblist = zalloc(aiol_zone);
1467 	ujoblist = zalloc(aiol_zone);
1468 	cbptr = uap->aiocbp;
1469 
1470 	for (i = 0; i < uap->nent; i++) {
1471 		cbp = (struct aiocb *)(intptr_t)fuword(&cbptr[i]);
1472 		if (cbp == 0)
1473 			continue;
1474 		ujoblist[njoblist] = cbp;
1475 		ijoblist[njoblist] = fuword(&cbp->_aiocb_private.kernelinfo);
1476 		njoblist++;
1477 	}
1478 
1479 	if (njoblist == 0) {
1480 		zfree(aiol_zone, ijoblist);
1481 		zfree(aiol_zone, ujoblist);
1482 		return 0;
1483 	}
1484 
1485 	error = 0;
1486 	for (;;) {
1487 		TAILQ_FOREACH(cb, &ki->kaio_jobdone, plist) {
1488 			for (i = 0; i < njoblist; i++) {
1489 				if (((intptr_t)
1490 				    cb->uaiocb._aiocb_private.kernelinfo) ==
1491 				    ijoblist[i]) {
1492 					if (ujoblist[i] != cb->uuaiocb)
1493 						error = EINVAL;
1494 					zfree(aiol_zone, ijoblist);
1495 					zfree(aiol_zone, ujoblist);
1496 					return error;
1497 				}
1498 			}
1499 		}
1500 
1501 		crit_enter();
1502 		for (cb = TAILQ_FIRST(&ki->kaio_bufdone); cb; cb =
1503 		    TAILQ_NEXT(cb, plist)) {
1504 			for (i = 0; i < njoblist; i++) {
1505 				if (((intptr_t)
1506 				    cb->uaiocb._aiocb_private.kernelinfo) ==
1507 				    ijoblist[i]) {
1508 					crit_exit();
1509 					if (ujoblist[i] != cb->uuaiocb)
1510 						error = EINVAL;
1511 					zfree(aiol_zone, ijoblist);
1512 					zfree(aiol_zone, ujoblist);
1513 					return error;
1514 				}
1515 			}
1516 		}
1517 
1518 		ki->kaio_flags |= KAIO_WAKEUP;
1519 		error = tsleep(p, PCATCH, "aiospn", timo);
1520 		crit_exit();
1521 
1522 		if (error == ERESTART || error == EINTR) {
1523 			zfree(aiol_zone, ijoblist);
1524 			zfree(aiol_zone, ujoblist);
1525 			return EINTR;
1526 		} else if (error == EWOULDBLOCK) {
1527 			zfree(aiol_zone, ijoblist);
1528 			zfree(aiol_zone, ujoblist);
1529 			return EAGAIN;
1530 		}
1531 	}
1532 
1533 /* NOTREACHED */
1534 	return EINVAL;
1535 #endif /* VFS_AIO */
1536 }
1537 
1538 /*
1539  * aio_cancel cancels any non-physio aio operations not currently in
1540  * progress.
1541  */
1542 int
1543 sys_aio_cancel(struct aio_cancel_args *uap)
1544 {
1545 #ifndef VFS_AIO
1546 	return ENOSYS;
1547 #else
1548 	struct proc *p = curproc;
1549 	struct kaioinfo *ki;
1550 	struct aiocblist *cbe, *cbn;
1551 	struct file *fp;
1552 	struct filedesc *fdp;
1553 	struct socket *so;
1554 	struct proc *po;
1555 	int error;
1556 	int cancelled=0;
1557 	int notcancelled=0;
1558 	struct vnode *vp;
1559 
1560 	fdp = p->p_fd;
1561 	if ((u_int)uap->fd >= fdp->fd_nfiles ||
1562 	    (fp = fdp->fd_files[uap->fd].fp) == NULL)
1563 		return (EBADF);
1564 
1565         if (fp->f_type == DTYPE_VNODE) {
1566 		vp = (struct vnode *)fp->f_data;
1567 
1568 		if (vn_isdisk(vp,&error)) {
1569 			uap->sysmsg_result = AIO_NOTCANCELED;
1570         	        return 0;
1571 		}
1572 	} else if (fp->f_type == DTYPE_SOCKET) {
1573 		so = (struct socket *)fp->f_data;
1574 
1575 		crit_enter();
1576 
1577 		for (cbe = TAILQ_FIRST(&so->so_aiojobq); cbe; cbe = cbn) {
1578 			cbn = TAILQ_NEXT(cbe, list);
1579 			if ((uap->aiocbp == NULL) ||
1580 				(uap->aiocbp == cbe->uuaiocb) ) {
1581 				po = cbe->userproc;
1582 				ki = po->p_aioinfo;
1583 				TAILQ_REMOVE(&so->so_aiojobq, cbe, list);
1584 				TAILQ_REMOVE(&ki->kaio_sockqueue, cbe, plist);
1585 				TAILQ_INSERT_TAIL(&ki->kaio_jobdone, cbe, plist);
1586 				if (ki->kaio_flags & KAIO_WAKEUP) {
1587 					wakeup(po);
1588 				}
1589 				cbe->jobstate = JOBST_JOBFINISHED;
1590 				cbe->uaiocb._aiocb_private.status=-1;
1591 				cbe->uaiocb._aiocb_private.error=ECANCELED;
1592 				cancelled++;
1593 /* XXX cancelled, knote? */
1594 			        if (cbe->uaiocb.aio_sigevent.sigev_notify ==
1595 				    SIGEV_SIGNAL)
1596 					ksignal(cbe->userproc, cbe->uaiocb.aio_sigevent.sigev_signo);
1597 				if (uap->aiocbp)
1598 					break;
1599 			}
1600 		}
1601 		crit_exit();
1602 
1603 		if ((cancelled) && (uap->aiocbp)) {
1604 			uap->sysmsg_result = AIO_CANCELED;
1605 			return 0;
1606 		}
1607 	}
1608 	ki=p->p_aioinfo;
1609 	if (ki == NULL)
1610 		goto done;
1611 	crit_enter();
1612 
1613 	for (cbe = TAILQ_FIRST(&ki->kaio_jobqueue); cbe; cbe = cbn) {
1614 		cbn = TAILQ_NEXT(cbe, plist);
1615 
1616 		if ((uap->fd == cbe->uaiocb.aio_fildes) &&
1617 		    ((uap->aiocbp == NULL ) ||
1618 		     (uap->aiocbp == cbe->uuaiocb))) {
1619 
1620 			if (cbe->jobstate == JOBST_JOBQGLOBAL) {
1621 				TAILQ_REMOVE(&aio_jobs, cbe, list);
1622                                 TAILQ_REMOVE(&ki->kaio_jobqueue, cbe, plist);
1623                                 TAILQ_INSERT_TAIL(&ki->kaio_jobdone, cbe,
1624                                     plist);
1625 				cancelled++;
1626 				ki->kaio_queue_finished_count++;
1627 				cbe->jobstate = JOBST_JOBFINISHED;
1628 				cbe->uaiocb._aiocb_private.status = -1;
1629 				cbe->uaiocb._aiocb_private.error = ECANCELED;
1630 /* XXX cancelled, knote? */
1631 			        if (cbe->uaiocb.aio_sigevent.sigev_notify ==
1632 				    SIGEV_SIGNAL)
1633 					ksignal(cbe->userproc, cbe->uaiocb.aio_sigevent.sigev_signo);
1634 			} else {
1635 				notcancelled++;
1636 			}
1637 		}
1638 	}
1639 	crit_exit();
1640 done:
1641 	if (notcancelled) {
1642 		uap->sysmsg_result = AIO_NOTCANCELED;
1643 		return 0;
1644 	}
1645 	if (cancelled) {
1646 		uap->sysmsg_result = AIO_CANCELED;
1647 		return 0;
1648 	}
1649 	uap->sysmsg_result = AIO_ALLDONE;
1650 
1651 	return 0;
1652 #endif /* VFS_AIO */
1653 }
1654 
1655 /*
1656  * aio_error is implemented in the kernel level for compatibility purposes only.
1657  * For a user mode async implementation, it would be best to do it in a userland
1658  * subroutine.
1659  */
1660 int
1661 sys_aio_error(struct aio_error_args *uap)
1662 {
1663 #ifndef VFS_AIO
1664 	return ENOSYS;
1665 #else
1666 	struct proc *p = curproc;
1667 	struct aiocblist *cb;
1668 	struct kaioinfo *ki;
1669 	long jobref;
1670 
1671 	ki = p->p_aioinfo;
1672 	if (ki == NULL)
1673 		return EINVAL;
1674 
1675 	jobref = fuword(&uap->aiocbp->_aiocb_private.kernelinfo);
1676 	if ((jobref == -1) || (jobref == 0))
1677 		return EINVAL;
1678 
1679 	TAILQ_FOREACH(cb, &ki->kaio_jobdone, plist) {
1680 		if (((intptr_t)cb->uaiocb._aiocb_private.kernelinfo) ==
1681 		    jobref) {
1682 			uap->sysmsg_result = cb->uaiocb._aiocb_private.error;
1683 			return 0;
1684 		}
1685 	}
1686 
1687 	crit_enter();
1688 
1689 	for (cb = TAILQ_FIRST(&ki->kaio_jobqueue); cb; cb = TAILQ_NEXT(cb,
1690 	    plist)) {
1691 		if (((intptr_t)cb->uaiocb._aiocb_private.kernelinfo) ==
1692 		    jobref) {
1693 			uap->sysmsg_result = EINPROGRESS;
1694 			crit_exit();
1695 			return 0;
1696 		}
1697 	}
1698 
1699 	for (cb = TAILQ_FIRST(&ki->kaio_sockqueue); cb; cb = TAILQ_NEXT(cb,
1700 	    plist)) {
1701 		if (((intptr_t)cb->uaiocb._aiocb_private.kernelinfo) ==
1702 		    jobref) {
1703 			uap->sysmsg_result = EINPROGRESS;
1704 			crit_exit();
1705 			return 0;
1706 		}
1707 	}
1708 	crit_exit();
1709 
1710 	crit_enter();
1711 	for (cb = TAILQ_FIRST(&ki->kaio_bufdone); cb; cb = TAILQ_NEXT(cb,
1712 	    plist)) {
1713 		if (((intptr_t)cb->uaiocb._aiocb_private.kernelinfo) ==
1714 		    jobref) {
1715 			uap->sysmsg_result = cb->uaiocb._aiocb_private.error;
1716 			crit_exit();
1717 			return 0;
1718 		}
1719 	}
1720 
1721 	for (cb = TAILQ_FIRST(&ki->kaio_bufqueue); cb; cb = TAILQ_NEXT(cb,
1722 	    plist)) {
1723 		if (((intptr_t)cb->uaiocb._aiocb_private.kernelinfo) ==
1724 		    jobref) {
1725 			uap->sysmsg_result = EINPROGRESS;
1726 			crit_exit();
1727 			return 0;
1728 		}
1729 	}
1730 	crit_exit();
1731 
1732 #if (0)
1733 	/*
1734 	 * Hack for lio.
1735 	 */
1736 	status = fuword(&uap->aiocbp->_aiocb_private.status);
1737 	if (status == -1)
1738 		return fuword(&uap->aiocbp->_aiocb_private.error);
1739 #endif
1740 	return EINVAL;
1741 #endif /* VFS_AIO */
1742 }
1743 
1744 /* syscall - asynchronous read from a file (REALTIME) */
1745 int
1746 sys_aio_read(struct aio_read_args *uap)
1747 {
1748 #ifndef VFS_AIO
1749 	return ENOSYS;
1750 #else
1751 	return aio_aqueue(uap->aiocbp, LIO_READ);
1752 #endif /* VFS_AIO */
1753 }
1754 
1755 /* syscall - asynchronous write to a file (REALTIME) */
1756 int
1757 sys_aio_write(struct aio_write_args *uap)
1758 {
1759 #ifndef VFS_AIO
1760 	return ENOSYS;
1761 #else
1762 	return aio_aqueue(uap->aiocbp, LIO_WRITE);
1763 #endif /* VFS_AIO */
1764 }
1765 
1766 /* syscall - XXX undocumented */
1767 int
1768 sys_lio_listio(struct lio_listio_args *uap)
1769 {
1770 #ifndef VFS_AIO
1771 	return ENOSYS;
1772 #else
1773 	struct proc *p = curproc;
1774 	struct lwp *lp = curthread->td_lwp;
1775 	int nent, nentqueued;
1776 	struct aiocb *iocb, * const *cbptr;
1777 	struct aiocblist *cb;
1778 	struct kaioinfo *ki;
1779 	struct aio_liojob *lj;
1780 	int error, runningcode;
1781 	int nerror;
1782 	int i;
1783 
1784 	if ((uap->mode != LIO_NOWAIT) && (uap->mode != LIO_WAIT))
1785 		return EINVAL;
1786 
1787 	nent = uap->nent;
1788 	if (nent > AIO_LISTIO_MAX)
1789 		return EINVAL;
1790 
1791 	if (p->p_aioinfo == NULL)
1792 		aio_init_aioinfo(p);
1793 
1794 	if ((nent + num_queue_count) > max_queue_count)
1795 		return EAGAIN;
1796 
1797 	ki = p->p_aioinfo;
1798 	if ((nent + ki->kaio_queue_count) > ki->kaio_qallowed_count)
1799 		return EAGAIN;
1800 
1801 	lj = zalloc(aiolio_zone);
1802 	if (!lj)
1803 		return EAGAIN;
1804 
1805 	lj->lioj_flags = 0;
1806 	lj->lioj_buffer_count = 0;
1807 	lj->lioj_buffer_finished_count = 0;
1808 	lj->lioj_queue_count = 0;
1809 	lj->lioj_queue_finished_count = 0;
1810 	lj->lioj_ki = ki;
1811 
1812 	/*
1813 	 * Setup signal.
1814 	 */
1815 	if (uap->sig && (uap->mode == LIO_NOWAIT)) {
1816 		error = copyin(uap->sig, &lj->lioj_signal,
1817 		    sizeof(lj->lioj_signal));
1818 		if (error) {
1819 			zfree(aiolio_zone, lj);
1820 			return error;
1821 		}
1822 		if (!_SIG_VALID(lj->lioj_signal.sigev_signo)) {
1823 			zfree(aiolio_zone, lj);
1824 			return EINVAL;
1825 		}
1826 		lj->lioj_flags |= LIOJ_SIGNAL;
1827 		lj->lioj_flags &= ~LIOJ_SIGNAL_POSTED;
1828 	} else
1829 		lj->lioj_flags &= ~LIOJ_SIGNAL;
1830 
1831 	TAILQ_INSERT_TAIL(&ki->kaio_liojoblist, lj, lioj_list);
1832 	/*
1833 	 * Get pointers to the list of I/O requests.
1834 	 */
1835 	nerror = 0;
1836 	nentqueued = 0;
1837 	cbptr = uap->acb_list;
1838 	for (i = 0; i < uap->nent; i++) {
1839 		iocb = (struct aiocb *)(intptr_t)fuword(&cbptr[i]);
1840 		if (((intptr_t)iocb != -1) && ((intptr_t)iocb != 0)) {
1841 			error = _aio_aqueue(iocb, lj, 0);
1842 			if (error == 0)
1843 				nentqueued++;
1844 			else
1845 				nerror++;
1846 		}
1847 	}
1848 
1849 	/*
1850 	 * If we haven't queued any, then just return error.
1851 	 */
1852 	if (nentqueued == 0)
1853 		return 0;
1854 
1855 	/*
1856 	 * Calculate the appropriate error return.
1857 	 */
1858 	runningcode = 0;
1859 	if (nerror)
1860 		runningcode = EIO;
1861 
1862 	if (uap->mode == LIO_WAIT) {
1863 		int command, found, jobref;
1864 
1865 		for (;;) {
1866 			found = 0;
1867 			for (i = 0; i < uap->nent; i++) {
1868 				/*
1869 				 * Fetch address of the control buf pointer in
1870 				 * user space.
1871 				 */
1872 				iocb = (struct aiocb *)
1873 				    (intptr_t)fuword(&cbptr[i]);
1874 				if (((intptr_t)iocb == -1) || ((intptr_t)iocb
1875 				    == 0))
1876 					continue;
1877 
1878 				/*
1879 				 * Fetch the associated command from user space.
1880 				 */
1881 				command = fuword(&iocb->aio_lio_opcode);
1882 				if (command == LIO_NOP) {
1883 					found++;
1884 					continue;
1885 				}
1886 
1887 				jobref = fuword(&iocb->_aiocb_private.kernelinfo);
1888 
1889 				TAILQ_FOREACH(cb, &ki->kaio_jobdone, plist) {
1890 					if (((intptr_t)cb->uaiocb._aiocb_private.kernelinfo)
1891 					    == jobref) {
1892 						if (cb->uaiocb.aio_lio_opcode
1893 						    == LIO_WRITE) {
1894 							lp->lwp_ru.ru_oublock +=
1895 							    cb->outputcharge;
1896 							cb->outputcharge = 0;
1897 						} else if (cb->uaiocb.aio_lio_opcode
1898 						    == LIO_READ) {
1899 							lp->lwp_ru.ru_inblock +=
1900 							    cb->inputcharge;
1901 							cb->inputcharge = 0;
1902 						}
1903 						found++;
1904 						break;
1905 					}
1906 				}
1907 
1908 				crit_enter();
1909 				TAILQ_FOREACH(cb, &ki->kaio_bufdone, plist) {
1910 					if (((intptr_t)cb->uaiocb._aiocb_private.kernelinfo)
1911 					    == jobref) {
1912 						found++;
1913 						break;
1914 					}
1915 				}
1916 				crit_exit();
1917 			}
1918 
1919 			/*
1920 			 * If all I/Os have been disposed of, then we can
1921 			 * return.
1922 			 */
1923 			if (found == nentqueued)
1924 				return runningcode;
1925 
1926 			ki->kaio_flags |= KAIO_WAKEUP;
1927 			error = tsleep(p, PCATCH, "aiospn", 0);
1928 
1929 			if (error == EINTR)
1930 				return EINTR;
1931 			else if (error == EWOULDBLOCK)
1932 				return EAGAIN;
1933 		}
1934 	}
1935 
1936 	return runningcode;
1937 #endif /* VFS_AIO */
1938 }
1939 
1940 #ifdef VFS_AIO
1941 /*
1942  * This is a weird hack so that we can post a signal.  It is safe to do so from
1943  * a timeout routine, but *not* from an interrupt routine.
1944  */
1945 static void
1946 process_signal(void *aioj)
1947 {
1948 	struct aiocblist *aiocbe = aioj;
1949 	struct aio_liojob *lj = aiocbe->lio;
1950 	struct aiocb *cb = &aiocbe->uaiocb;
1951 
1952 	if ((lj) && (lj->lioj_signal.sigev_notify == SIGEV_SIGNAL) &&
1953 	    (lj->lioj_queue_count == lj->lioj_queue_finished_count)) {
1954 		ksignal(lj->lioj_ki->kaio_p, lj->lioj_signal.sigev_signo);
1955 		lj->lioj_flags |= LIOJ_SIGNAL_POSTED;
1956 	}
1957 
1958 	if (cb->aio_sigevent.sigev_notify == SIGEV_SIGNAL)
1959 		ksignal(aiocbe->userproc, cb->aio_sigevent.sigev_signo);
1960 }
1961 
1962 /*
1963  * Interrupt handler for physio, performs the necessary process wakeups, and
1964  * signals.
1965  */
1966 static void
1967 aio_physwakeup(struct bio *bio)
1968 {
1969 	struct buf *bp = bio->bio_buf;
1970 	struct aiocblist *aiocbe;
1971 	struct proc *p;
1972 	struct kaioinfo *ki;
1973 	struct aio_liojob *lj;
1974 
1975 	aiocbe = bio->bio_caller_info2.ptr;
1976 
1977 	if (aiocbe) {
1978 		p = bio->bio_caller_info1.ptr;
1979 
1980 		aiocbe->jobstate = JOBST_JOBBFINISHED;
1981 		aiocbe->uaiocb._aiocb_private.status -= bp->b_resid;
1982 		aiocbe->uaiocb._aiocb_private.error = 0;
1983 		aiocbe->jobflags |= AIOCBLIST_DONE;
1984 
1985 		if (bp->b_flags & B_ERROR)
1986 			aiocbe->uaiocb._aiocb_private.error = bp->b_error;
1987 
1988 		lj = aiocbe->lio;
1989 		if (lj) {
1990 			lj->lioj_buffer_finished_count++;
1991 
1992 			/*
1993 			 * wakeup/signal if all of the interrupt jobs are done.
1994 			 */
1995 			if (lj->lioj_buffer_finished_count ==
1996 			    lj->lioj_buffer_count) {
1997 				/*
1998 				 * Post a signal if it is called for.
1999 				 */
2000 				if ((lj->lioj_flags &
2001 				    (LIOJ_SIGNAL|LIOJ_SIGNAL_POSTED)) ==
2002 				    LIOJ_SIGNAL) {
2003 					lj->lioj_flags |= LIOJ_SIGNAL_POSTED;
2004 					callout_reset(&aiocbe->timeout, 0,
2005 							process_signal, aiocbe);
2006 				}
2007 			}
2008 		}
2009 
2010 		ki = p->p_aioinfo;
2011 		if (ki) {
2012 			ki->kaio_buffer_finished_count++;
2013 			TAILQ_REMOVE(&aio_bufjobs, aiocbe, list);
2014 			TAILQ_REMOVE(&ki->kaio_bufqueue, aiocbe, plist);
2015 			TAILQ_INSERT_TAIL(&ki->kaio_bufdone, aiocbe, plist);
2016 
2017 			KNOTE(&aiocbe->klist, 0);
2018 			/* Do the wakeup. */
2019 			if (ki->kaio_flags & (KAIO_RUNDOWN|KAIO_WAKEUP)) {
2020 				ki->kaio_flags &= ~KAIO_WAKEUP;
2021 				wakeup(p);
2022 			}
2023 		}
2024 
2025 		if (aiocbe->uaiocb.aio_sigevent.sigev_notify == SIGEV_SIGNAL) {
2026 			callout_reset(&aiocbe->timeout, 0,
2027 					process_signal, aiocbe);
2028 		}
2029 	}
2030 	bp->b_cmd = BUF_CMD_DONE;
2031 	wakeup(bp);
2032 }
2033 #endif /* VFS_AIO */
2034 
2035 /* syscall - wait for the next completion of an aio request */
2036 int
2037 sys_aio_waitcomplete(struct aio_waitcomplete_args *uap)
2038 {
2039 #ifndef VFS_AIO
2040 	return ENOSYS;
2041 #else
2042 	struct proc *p = curproc;
2043 	struct lwp *lp = curthread->td_lwp;
2044 	struct timeval atv;
2045 	struct timespec ts;
2046 	struct kaioinfo *ki;
2047 	struct aiocblist *cb = NULL;
2048 	int error, timo;
2049 
2050 	suword(uap->aiocbp, (int)NULL);
2051 
2052 	timo = 0;
2053 	if (uap->timeout) {
2054 		/* Get timespec struct. */
2055 		error = copyin(uap->timeout, &ts, sizeof(ts));
2056 		if (error)
2057 			return error;
2058 
2059 		if ((ts.tv_nsec < 0) || (ts.tv_nsec >= 1000000000))
2060 			return (EINVAL);
2061 
2062 		TIMESPEC_TO_TIMEVAL(&atv, &ts);
2063 		if (itimerfix(&atv))
2064 			return (EINVAL);
2065 		timo = tvtohz_high(&atv);
2066 	}
2067 
2068 	ki = p->p_aioinfo;
2069 	if (ki == NULL)
2070 		return EAGAIN;
2071 
2072 	for (;;) {
2073 		if ((cb = TAILQ_FIRST(&ki->kaio_jobdone)) != 0) {
2074 			suword(uap->aiocbp, (uintptr_t)cb->uuaiocb);
2075 			uap->sysmsg_result = cb->uaiocb._aiocb_private.status;
2076 			if (cb->uaiocb.aio_lio_opcode == LIO_WRITE) {
2077 				lp->lwp_ru.ru_oublock +=
2078 				    cb->outputcharge;
2079 				cb->outputcharge = 0;
2080 			} else if (cb->uaiocb.aio_lio_opcode == LIO_READ) {
2081 				lp->lwp_ru.ru_inblock += cb->inputcharge;
2082 				cb->inputcharge = 0;
2083 			}
2084 			aio_free_entry(cb);
2085 			return cb->uaiocb._aiocb_private.error;
2086 		}
2087 
2088 		crit_enter();
2089  		if ((cb = TAILQ_FIRST(&ki->kaio_bufdone)) != 0 ) {
2090 			crit_exit();
2091 			suword(uap->aiocbp, (uintptr_t)cb->uuaiocb);
2092 			uap->sysmsg_result = cb->uaiocb._aiocb_private.status;
2093 			aio_free_entry(cb);
2094 			return cb->uaiocb._aiocb_private.error;
2095 		}
2096 
2097 		ki->kaio_flags |= KAIO_WAKEUP;
2098 		error = tsleep(p, PCATCH, "aiowc", timo);
2099 		crit_exit();
2100 
2101 		if (error == ERESTART)
2102 			return EINTR;
2103 		else if (error < 0)
2104 			return error;
2105 		else if (error == EINTR)
2106 			return EINTR;
2107 		else if (error == EWOULDBLOCK)
2108 			return EAGAIN;
2109 	}
2110 #endif /* VFS_AIO */
2111 }
2112 
2113 #ifndef VFS_AIO
2114 static int
2115 filt_aioattach(struct knote *kn)
2116 {
2117 
2118 	return (ENXIO);
2119 }
2120 
2121 struct filterops aio_filtops =
2122 	{ 0, filt_aioattach, NULL, NULL };
2123 
2124 #else
2125 /* kqueue attach function */
2126 static int
2127 filt_aioattach(struct knote *kn)
2128 {
2129 	struct aiocblist *aiocbe = (struct aiocblist *)kn->kn_sdata;
2130 
2131 	/*
2132 	 * The aiocbe pointer must be validated before using it, so
2133 	 * registration is restricted to the kernel; the user cannot
2134 	 * set EV_FLAG1.
2135 	 */
2136 	if ((kn->kn_flags & EV_FLAG1) == 0)
2137 		return (EPERM);
2138 	kn->kn_flags &= ~EV_FLAG1;
2139 
2140 	SLIST_INSERT_HEAD(&aiocbe->klist, kn, kn_selnext);
2141 
2142 	return (0);
2143 }
2144 
2145 /* kqueue detach function */
2146 static void
2147 filt_aiodetach(struct knote *kn)
2148 {
2149 	struct aiocblist *aiocbe = (struct aiocblist *)kn->kn_sdata;
2150 
2151 	SLIST_REMOVE(&aiocbe->klist, kn, knote, kn_selnext);
2152 }
2153 
2154 /* kqueue filter function */
2155 /*ARGSUSED*/
2156 static int
2157 filt_aio(struct knote *kn, long hint)
2158 {
2159 	struct aiocblist *aiocbe = (struct aiocblist *)kn->kn_sdata;
2160 
2161 	kn->kn_data = aiocbe->uaiocb._aiocb_private.error;
2162 	if (aiocbe->jobstate != JOBST_JOBFINISHED &&
2163 	    aiocbe->jobstate != JOBST_JOBBFINISHED)
2164 		return (0);
2165 	kn->kn_flags |= EV_EOF;
2166 	return (1);
2167 }
2168 
2169 struct filterops aio_filtops =
2170 	{ 0, filt_aioattach, filt_aiodetach, filt_aio };
2171 #endif /* VFS_AIO */
2172