xref: /dragonfly/sys/kern/vfs_aio.c (revision 10cbe914)
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 
51 #include <sys/file2.h>
52 #include <sys/buf2.h>
53 #include <sys/sysref2.h>
54 #include <sys/thread2.h>
55 #include <sys/mplock2.h>
56 
57 #include <machine/limits.h>
58 #include "opt_vfs_aio.h"
59 
60 #ifdef VFS_AIO
61 
62 /*
63  * Counter for allocating reference ids to new jobs.  Wrapped to 1 on
64  * overflow.
65  */
66 static	long jobrefid;
67 
68 #define JOBST_NULL		0x0
69 #define JOBST_JOBQGLOBAL	0x2
70 #define JOBST_JOBRUNNING	0x3
71 #define JOBST_JOBFINISHED	0x4
72 #define	JOBST_JOBQBUF		0x5
73 #define	JOBST_JOBBFINISHED	0x6
74 
75 #ifndef MAX_AIO_PER_PROC
76 #define MAX_AIO_PER_PROC	32
77 #endif
78 
79 #ifndef MAX_AIO_QUEUE_PER_PROC
80 #define MAX_AIO_QUEUE_PER_PROC	256 /* Bigger than AIO_LISTIO_MAX */
81 #endif
82 
83 #ifndef MAX_AIO_PROCS
84 #define MAX_AIO_PROCS		32
85 #endif
86 
87 #ifndef MAX_AIO_QUEUE
88 #define	MAX_AIO_QUEUE		1024 /* Bigger than AIO_LISTIO_MAX */
89 #endif
90 
91 #ifndef TARGET_AIO_PROCS
92 #define TARGET_AIO_PROCS	4
93 #endif
94 
95 #ifndef MAX_BUF_AIO
96 #define MAX_BUF_AIO		16
97 #endif
98 
99 #ifndef AIOD_TIMEOUT_DEFAULT
100 #define	AIOD_TIMEOUT_DEFAULT	(10 * hz)
101 #endif
102 
103 #ifndef AIOD_LIFETIME_DEFAULT
104 #define AIOD_LIFETIME_DEFAULT	(30 * hz)
105 #endif
106 
107 SYSCTL_NODE(_vfs, OID_AUTO, aio, CTLFLAG_RW, 0, "Async IO management");
108 
109 static int max_aio_procs = MAX_AIO_PROCS;
110 SYSCTL_INT(_vfs_aio, OID_AUTO, max_aio_procs,
111 	CTLFLAG_RW, &max_aio_procs, 0,
112 	"Maximum number of kernel threads to use for handling async IO");
113 
114 static int num_aio_procs = 0;
115 SYSCTL_INT(_vfs_aio, OID_AUTO, num_aio_procs,
116 	CTLFLAG_RD, &num_aio_procs, 0,
117 	"Number of presently active kernel threads for async IO");
118 
119 /*
120  * The code will adjust the actual number of AIO processes towards this
121  * number when it gets a chance.
122  */
123 static int target_aio_procs = TARGET_AIO_PROCS;
124 SYSCTL_INT(_vfs_aio, OID_AUTO, target_aio_procs, CTLFLAG_RW, &target_aio_procs,
125 	0, "Preferred number of ready kernel threads for async IO");
126 
127 static int max_queue_count = MAX_AIO_QUEUE;
128 SYSCTL_INT(_vfs_aio, OID_AUTO, max_aio_queue, CTLFLAG_RW, &max_queue_count, 0,
129     "Maximum number of aio requests to queue, globally");
130 
131 static int num_queue_count = 0;
132 SYSCTL_INT(_vfs_aio, OID_AUTO, num_queue_count, CTLFLAG_RD, &num_queue_count, 0,
133     "Number of queued aio requests");
134 
135 static int num_buf_aio = 0;
136 SYSCTL_INT(_vfs_aio, OID_AUTO, num_buf_aio, CTLFLAG_RD, &num_buf_aio, 0,
137     "Number of aio requests presently handled by the buf subsystem");
138 
139 /* Number of async I/O thread in the process of being started */
140 /* XXX This should be local to _aio_aqueue() */
141 static int num_aio_resv_start = 0;
142 
143 static int aiod_timeout;
144 SYSCTL_INT(_vfs_aio, OID_AUTO, aiod_timeout, CTLFLAG_RW, &aiod_timeout, 0,
145     "Timeout value for synchronous aio operations");
146 
147 static int aiod_lifetime;
148 SYSCTL_INT(_vfs_aio, OID_AUTO, aiod_lifetime, CTLFLAG_RW, &aiod_lifetime, 0,
149     "Maximum lifetime for idle aiod");
150 
151 static int max_aio_per_proc = MAX_AIO_PER_PROC;
152 SYSCTL_INT(_vfs_aio, OID_AUTO, max_aio_per_proc, CTLFLAG_RW, &max_aio_per_proc,
153     0, "Maximum active aio requests per process (stored in the process)");
154 
155 static int max_aio_queue_per_proc = MAX_AIO_QUEUE_PER_PROC;
156 SYSCTL_INT(_vfs_aio, OID_AUTO, max_aio_queue_per_proc, CTLFLAG_RW,
157     &max_aio_queue_per_proc, 0,
158     "Maximum queued aio requests per process (stored in the process)");
159 
160 static int max_buf_aio = MAX_BUF_AIO;
161 SYSCTL_INT(_vfs_aio, OID_AUTO, max_buf_aio, CTLFLAG_RW, &max_buf_aio, 0,
162     "Maximum buf aio requests per process (stored in the process)");
163 
164 /*
165  * AIO process info
166  */
167 #define AIOP_FREE	0x1			/* proc on free queue */
168 #define AIOP_SCHED	0x2			/* proc explicitly scheduled */
169 
170 struct aioproclist {
171 	int aioprocflags;			/* AIO proc flags */
172 	TAILQ_ENTRY(aioproclist) list;		/* List of processes */
173 	struct proc *aioproc;			/* The AIO thread */
174 };
175 
176 /*
177  * data-structure for lio signal management
178  */
179 struct aio_liojob {
180 	int	lioj_flags;
181 	int	lioj_buffer_count;
182 	int	lioj_buffer_finished_count;
183 	int	lioj_queue_count;
184 	int	lioj_queue_finished_count;
185 	struct	sigevent lioj_signal;	/* signal on all I/O done */
186 	TAILQ_ENTRY(aio_liojob) lioj_list;
187 	struct	kaioinfo *lioj_ki;
188 };
189 #define	LIOJ_SIGNAL		0x1	/* signal on all done (lio) */
190 #define	LIOJ_SIGNAL_POSTED	0x2	/* signal has been posted */
191 
192 /*
193  * per process aio data structure
194  */
195 struct kaioinfo {
196 	int	kaio_flags;		/* per process kaio flags */
197 	int	kaio_maxactive_count;	/* maximum number of AIOs */
198 	int	kaio_active_count;	/* number of currently used AIOs */
199 	int	kaio_qallowed_count;	/* maxiumu size of AIO queue */
200 	int	kaio_queue_count;	/* size of AIO queue */
201 	int	kaio_ballowed_count;	/* maximum number of buffers */
202 	int	kaio_queue_finished_count; /* number of daemon jobs finished */
203 	int	kaio_buffer_count;	/* number of physio buffers */
204 	int	kaio_buffer_finished_count; /* count of I/O done */
205 	struct 	proc *kaio_p;		/* process that uses this kaio block */
206 	TAILQ_HEAD(,aio_liojob) kaio_liojoblist; /* list of lio jobs */
207 	TAILQ_HEAD(,aiocblist) kaio_jobqueue;	/* job queue for process */
208 	TAILQ_HEAD(,aiocblist) kaio_jobdone;	/* done queue for process */
209 	TAILQ_HEAD(,aiocblist) kaio_bufqueue;	/* buffer job queue for process */
210 	TAILQ_HEAD(,aiocblist) kaio_bufdone;	/* buffer done queue for process */
211 	TAILQ_HEAD(,aiocblist) kaio_sockqueue;	/* queue for aios waiting on sockets */
212 };
213 
214 #define KAIO_RUNDOWN	0x1	/* process is being run down */
215 #define KAIO_WAKEUP	0x2	/* wakeup process when there is a significant event */
216 
217 static TAILQ_HEAD(,aioproclist) aio_freeproc, aio_activeproc;
218 static TAILQ_HEAD(,aiocblist) aio_jobs;			/* Async job list */
219 static TAILQ_HEAD(,aiocblist) aio_bufjobs;		/* Phys I/O job list */
220 static TAILQ_HEAD(,aiocblist) aio_freejobs;		/* Pool of free jobs */
221 
222 static void	aio_init_aioinfo(struct proc *p);
223 static void	aio_onceonly(void *);
224 static int	aio_free_entry(struct aiocblist *aiocbe);
225 static void	aio_process(struct aiocblist *aiocbe);
226 static int	aio_newproc(void);
227 static int	aio_aqueue(struct aiocb *job, int type);
228 static void	aio_physwakeup(struct bio *bio);
229 static int	aio_fphysio(struct aiocblist *aiocbe);
230 static int	aio_qphysio(struct proc *p, struct aiocblist *iocb);
231 static void	aio_daemon(void *uproc, struct trapframe *frame);
232 static void	process_signal(void *aioj);
233 
234 SYSINIT(aio, SI_SUB_VFS, SI_ORDER_ANY, aio_onceonly, NULL);
235 
236 /*
237  * Zones for:
238  * 	kaio	Per process async io info
239  *	aiop	async io thread data
240  *	aiocb	async io jobs
241  *	aiol	list io job pointer - internal to aio_suspend XXX
242  *	aiolio	list io jobs
243  */
244 static vm_zone_t kaio_zone, aiop_zone, aiocb_zone, aiol_zone, aiolio_zone;
245 
246 /*
247  * Startup initialization
248  */
249 static void
250 aio_onceonly(void *na)
251 {
252 	TAILQ_INIT(&aio_freeproc);
253 	TAILQ_INIT(&aio_activeproc);
254 	TAILQ_INIT(&aio_jobs);
255 	TAILQ_INIT(&aio_bufjobs);
256 	TAILQ_INIT(&aio_freejobs);
257 	kaio_zone = zinit("AIO", sizeof(struct kaioinfo), 0, 0, 1);
258 	aiop_zone = zinit("AIOP", sizeof(struct aioproclist), 0, 0, 1);
259 	aiocb_zone = zinit("AIOCB", sizeof(struct aiocblist), 0, 0, 1);
260 	aiol_zone = zinit("AIOL", AIO_LISTIO_MAX*sizeof(intptr_t), 0, 0, 1);
261 	aiolio_zone = zinit("AIOLIO", sizeof(struct aio_liojob), 0, 0, 1);
262 	aiod_timeout = AIOD_TIMEOUT_DEFAULT;
263 	aiod_lifetime = AIOD_LIFETIME_DEFAULT;
264 	jobrefid = 1;
265 }
266 
267 /*
268  * Init the per-process aioinfo structure.  The aioinfo limits are set
269  * per-process for user limit (resource) management.
270  */
271 static void
272 aio_init_aioinfo(struct proc *p)
273 {
274 	struct kaioinfo *ki;
275 	if (p->p_aioinfo == NULL) {
276 		ki = zalloc(kaio_zone);
277 		p->p_aioinfo = ki;
278 		ki->kaio_flags = 0;
279 		ki->kaio_maxactive_count = max_aio_per_proc;
280 		ki->kaio_active_count = 0;
281 		ki->kaio_qallowed_count = max_aio_queue_per_proc;
282 		ki->kaio_queue_count = 0;
283 		ki->kaio_ballowed_count = max_buf_aio;
284 		ki->kaio_buffer_count = 0;
285 		ki->kaio_buffer_finished_count = 0;
286 		ki->kaio_p = p;
287 		TAILQ_INIT(&ki->kaio_jobdone);
288 		TAILQ_INIT(&ki->kaio_jobqueue);
289 		TAILQ_INIT(&ki->kaio_bufdone);
290 		TAILQ_INIT(&ki->kaio_bufqueue);
291 		TAILQ_INIT(&ki->kaio_liojoblist);
292 		TAILQ_INIT(&ki->kaio_sockqueue);
293 	}
294 
295 	while (num_aio_procs < target_aio_procs)
296 		aio_newproc();
297 }
298 
299 /*
300  * Free a job entry.  Wait for completion if it is currently active, but don't
301  * delay forever.  If we delay, we return a flag that says that we have to
302  * restart the queue scan.
303  */
304 static int
305 aio_free_entry(struct aiocblist *aiocbe)
306 {
307 	struct kaioinfo *ki;
308 	struct aio_liojob *lj;
309 	struct proc *p;
310 	int error;
311 
312 	if (aiocbe->jobstate == JOBST_NULL)
313 		panic("aio_free_entry: freeing already free job");
314 
315 	p = aiocbe->userproc;
316 	ki = p->p_aioinfo;
317 	lj = aiocbe->lio;
318 	if (ki == NULL)
319 		panic("aio_free_entry: missing p->p_aioinfo");
320 
321 	while (aiocbe->jobstate == JOBST_JOBRUNNING) {
322 		aiocbe->jobflags |= AIOCBLIST_RUNDOWN;
323 		tsleep(aiocbe, 0, "jobwai", 0);
324 	}
325 	if (aiocbe->bp == NULL) {
326 		if (ki->kaio_queue_count <= 0)
327 			panic("aio_free_entry: process queue size <= 0");
328 		if (num_queue_count <= 0)
329 			panic("aio_free_entry: system wide queue size <= 0");
330 
331 		if (lj) {
332 			lj->lioj_queue_count--;
333 			if (aiocbe->jobflags & AIOCBLIST_DONE)
334 				lj->lioj_queue_finished_count--;
335 		}
336 		ki->kaio_queue_count--;
337 		if (aiocbe->jobflags & AIOCBLIST_DONE)
338 			ki->kaio_queue_finished_count--;
339 		num_queue_count--;
340 	} else {
341 		if (lj) {
342 			lj->lioj_buffer_count--;
343 			if (aiocbe->jobflags & AIOCBLIST_DONE)
344 				lj->lioj_buffer_finished_count--;
345 		}
346 		if (aiocbe->jobflags & AIOCBLIST_DONE)
347 			ki->kaio_buffer_finished_count--;
348 		ki->kaio_buffer_count--;
349 		num_buf_aio--;
350 	}
351 
352 	/* aiocbe is going away, we need to destroy any knotes */
353 	/* XXX lwp knote wants a thread, but only cares about the process */
354 	knote_empty(&aiocbe->klist);
355 
356 	if ((ki->kaio_flags & KAIO_WAKEUP) || ((ki->kaio_flags & KAIO_RUNDOWN)
357 	    && ((ki->kaio_buffer_count == 0) && (ki->kaio_queue_count == 0)))) {
358 		ki->kaio_flags &= ~KAIO_WAKEUP;
359 		wakeup(p);
360 	}
361 
362 	if (aiocbe->jobstate == JOBST_JOBQBUF) {
363 		if ((error = aio_fphysio(aiocbe)) != 0)
364 			return error;
365 		if (aiocbe->jobstate != JOBST_JOBBFINISHED)
366 			panic("aio_free_entry: invalid physio finish-up state");
367 		crit_enter();
368 		TAILQ_REMOVE(&ki->kaio_bufdone, aiocbe, plist);
369 		crit_exit();
370 	} else if (aiocbe->jobstate == JOBST_JOBQGLOBAL) {
371 		crit_enter();
372 		TAILQ_REMOVE(&aio_jobs, aiocbe, list);
373 		TAILQ_REMOVE(&ki->kaio_jobqueue, aiocbe, plist);
374 		crit_exit();
375 	} else if (aiocbe->jobstate == JOBST_JOBFINISHED)
376 		TAILQ_REMOVE(&ki->kaio_jobdone, aiocbe, plist);
377 	else if (aiocbe->jobstate == JOBST_JOBBFINISHED) {
378 		crit_enter();
379 		TAILQ_REMOVE(&ki->kaio_bufdone, aiocbe, plist);
380 		crit_exit();
381 		if (aiocbe->bp) {
382 			vunmapbuf(aiocbe->bp);
383 			relpbuf(aiocbe->bp, NULL);
384 			aiocbe->bp = NULL;
385 		}
386 	}
387 	if (lj && (lj->lioj_buffer_count == 0) && (lj->lioj_queue_count == 0)) {
388 		TAILQ_REMOVE(&ki->kaio_liojoblist, lj, lioj_list);
389 		zfree(aiolio_zone, lj);
390 	}
391 	aiocbe->jobstate = JOBST_NULL;
392 	callout_stop(&aiocbe->timeout);
393 	fdrop(aiocbe->fd_file);
394 	TAILQ_INSERT_HEAD(&aio_freejobs, aiocbe, list);
395 	return 0;
396 }
397 #endif /* VFS_AIO */
398 
399 /*
400  * Rundown the jobs for a given process.
401  */
402 void
403 aio_proc_rundown(struct proc *p)
404 {
405 #ifndef VFS_AIO
406 	return;
407 #else
408 	struct kaioinfo *ki;
409 	struct aio_liojob *lj, *ljn;
410 	struct aiocblist *aiocbe, *aiocbn;
411 	struct file *fp;
412 	struct socket *so;
413 
414 	ki = p->p_aioinfo;
415 	if (ki == NULL)
416 		return;
417 
418 	ki->kaio_flags |= LIOJ_SIGNAL_POSTED;
419 	while ((ki->kaio_active_count > 0) || (ki->kaio_buffer_count >
420 	    ki->kaio_buffer_finished_count)) {
421 		ki->kaio_flags |= KAIO_RUNDOWN;
422 		if (tsleep(p, 0, "kaiowt", aiod_timeout))
423 			break;
424 	}
425 
426 	/*
427 	 * Move any aio ops that are waiting on socket I/O to the normal job
428 	 * queues so they are cleaned up with any others.
429 	 */
430 	crit_enter();
431 	for (aiocbe = TAILQ_FIRST(&ki->kaio_sockqueue); aiocbe; aiocbe =
432 	    aiocbn) {
433 		aiocbn = TAILQ_NEXT(aiocbe, plist);
434 		fp = aiocbe->fd_file;
435 		if (fp != NULL) {
436 			so = (struct socket *)fp->f_data;
437 			TAILQ_REMOVE(&so->so_aiojobq, aiocbe, list);
438 			if (TAILQ_EMPTY(&so->so_aiojobq)) {
439 				atomic_clear_int(&so->so_snd.ssb_flags,
440 						 SSB_AIO);
441 				atomic_clear_int(&so->so_rcv.ssb_flags,
442 						 SSB_AIO);
443 			}
444 		}
445 		TAILQ_REMOVE(&ki->kaio_sockqueue, aiocbe, plist);
446 		TAILQ_INSERT_HEAD(&aio_jobs, aiocbe, list);
447 		TAILQ_INSERT_HEAD(&ki->kaio_jobqueue, aiocbe, plist);
448 	}
449 	crit_exit();
450 
451 restart1:
452 	for (aiocbe = TAILQ_FIRST(&ki->kaio_jobdone); aiocbe; aiocbe = aiocbn) {
453 		aiocbn = TAILQ_NEXT(aiocbe, plist);
454 		if (aio_free_entry(aiocbe))
455 			goto restart1;
456 	}
457 
458 restart2:
459 	for (aiocbe = TAILQ_FIRST(&ki->kaio_jobqueue); aiocbe; aiocbe =
460 	    aiocbn) {
461 		aiocbn = TAILQ_NEXT(aiocbe, plist);
462 		if (aio_free_entry(aiocbe))
463 			goto restart2;
464 	}
465 
466 restart3:
467 	crit_enter();
468 	while (TAILQ_FIRST(&ki->kaio_bufqueue)) {
469 		ki->kaio_flags |= KAIO_WAKEUP;
470 		tsleep(p, 0, "aioprn", 0);
471 		crit_exit();
472 		goto restart3;
473 	}
474 	crit_exit();
475 
476 restart4:
477 	crit_enter();
478 	for (aiocbe = TAILQ_FIRST(&ki->kaio_bufdone); aiocbe; aiocbe = aiocbn) {
479 		aiocbn = TAILQ_NEXT(aiocbe, plist);
480 		if (aio_free_entry(aiocbe)) {
481 			crit_exit();
482 			goto restart4;
483 		}
484 	}
485 	crit_exit();
486 
487         /*
488          * If we've slept, jobs might have moved from one queue to another.
489          * Retry rundown if we didn't manage to empty the queues.
490          */
491         if (TAILQ_FIRST(&ki->kaio_jobdone) != NULL ||
492 	    TAILQ_FIRST(&ki->kaio_jobqueue) != NULL ||
493 	    TAILQ_FIRST(&ki->kaio_bufqueue) != NULL ||
494 	    TAILQ_FIRST(&ki->kaio_bufdone) != NULL)
495 		goto restart1;
496 
497 	for (lj = TAILQ_FIRST(&ki->kaio_liojoblist); lj; lj = ljn) {
498 		ljn = TAILQ_NEXT(lj, lioj_list);
499 		if ((lj->lioj_buffer_count == 0) && (lj->lioj_queue_count ==
500 		    0)) {
501 			TAILQ_REMOVE(&ki->kaio_liojoblist, lj, lioj_list);
502 			zfree(aiolio_zone, lj);
503 		} else {
504 #ifdef DIAGNOSTIC
505 			kprintf("LIO job not cleaned up: B:%d, BF:%d, Q:%d, "
506 			    "QF:%d\n", lj->lioj_buffer_count,
507 			    lj->lioj_buffer_finished_count,
508 			    lj->lioj_queue_count,
509 			    lj->lioj_queue_finished_count);
510 #endif
511 		}
512 	}
513 
514 	zfree(kaio_zone, ki);
515 	p->p_aioinfo = NULL;
516 #endif /* VFS_AIO */
517 }
518 
519 #ifdef VFS_AIO
520 /*
521  * Select a job to run (called by an AIO daemon).
522  */
523 static struct aiocblist *
524 aio_selectjob(struct aioproclist *aiop)
525 {
526 	struct aiocblist *aiocbe;
527 	struct kaioinfo *ki;
528 	struct proc *userp;
529 
530 	crit_enter();
531 	for (aiocbe = TAILQ_FIRST(&aio_jobs); aiocbe; aiocbe =
532 	    TAILQ_NEXT(aiocbe, list)) {
533 		userp = aiocbe->userproc;
534 		ki = userp->p_aioinfo;
535 
536 		if (ki->kaio_active_count < ki->kaio_maxactive_count) {
537 			TAILQ_REMOVE(&aio_jobs, aiocbe, list);
538 			crit_exit();
539 			return aiocbe;
540 		}
541 	}
542 	crit_exit();
543 
544 	return NULL;
545 }
546 
547 /*
548  * The AIO processing activity.  This is the code that does the I/O request for
549  * the non-physio version of the operations.  The normal vn operations are used,
550  * and this code should work in all instances for every type of file, including
551  * pipes, sockets, fifos, and regular files.
552  */
553 static void
554 aio_process(struct aiocblist *aiocbe)
555 {
556 	struct thread *mytd;
557 	struct aiocb *cb;
558 	struct file *fp;
559 	struct uio auio;
560 	struct iovec aiov;
561 	int cnt;
562 	int error;
563 	int oublock_st, oublock_end;
564 	int inblock_st, inblock_end;
565 
566 	mytd = curthread;
567 	cb = &aiocbe->uaiocb;
568 	fp = aiocbe->fd_file;
569 
570 	aiov.iov_base = (void *)(uintptr_t)cb->aio_buf;
571 	aiov.iov_len = cb->aio_nbytes;
572 
573 	auio.uio_iov = &aiov;
574 	auio.uio_iovcnt = 1;
575 	auio.uio_offset = cb->aio_offset;
576 	auio.uio_resid = cb->aio_nbytes;
577 	cnt = cb->aio_nbytes;
578 	auio.uio_segflg = UIO_USERSPACE;
579 	auio.uio_td = mytd;
580 
581 	inblock_st = mytd->td_lwp->lwp_ru.ru_inblock;
582 	oublock_st = mytd->td_lwp->lwp_ru.ru_oublock;
583 	/*
584 	 * _aio_aqueue() acquires a reference to the file that is
585 	 * released in aio_free_entry().
586 	 */
587 	if (cb->aio_lio_opcode == LIO_READ) {
588 		auio.uio_rw = UIO_READ;
589 		error = fo_read(fp, &auio, fp->f_cred, O_FOFFSET);
590 	} else {
591 		auio.uio_rw = UIO_WRITE;
592 		error = fo_write(fp, &auio, fp->f_cred, O_FOFFSET);
593 	}
594 	inblock_end = mytd->td_lwp->lwp_ru.ru_inblock;
595 	oublock_end = mytd->td_lwp->lwp_ru.ru_oublock;
596 
597 	aiocbe->inputcharge = inblock_end - inblock_st;
598 	aiocbe->outputcharge = oublock_end - oublock_st;
599 
600 	if ((error) && (auio.uio_resid != cnt)) {
601 		if (error == ERESTART || error == EINTR || error == EWOULDBLOCK)
602 			error = 0;
603 		if ((error == EPIPE) && (cb->aio_lio_opcode == LIO_WRITE))
604 			ksignal(aiocbe->userproc, SIGPIPE);
605 	}
606 
607 	cnt -= auio.uio_resid;
608 	cb->_aiocb_private.error = error;
609 	cb->_aiocb_private.status = cnt;
610 }
611 
612 /*
613  * The AIO daemon, most of the actual work is done in aio_process,
614  * but the setup (and address space mgmt) is done in this routine.
615  */
616 static void
617 aio_daemon(void *uproc, struct trapframe *frame)
618 {
619 	struct aio_liojob *lj;
620 	struct aiocb *cb;
621 	struct aiocblist *aiocbe;
622 	struct aioproclist *aiop;
623 	struct kaioinfo *ki;
624 	struct proc *mycp, *userp;
625 	struct vmspace *curvm;
626 	struct lwp *mylwp;
627 	struct ucred *cr;
628 
629 	/*
630 	 * mplock not held on entry but we aren't mpsafe yet.
631 	 */
632 	get_mplock();
633 
634 	mylwp = curthread->td_lwp;
635 	mycp = mylwp->lwp_proc;
636 
637 	if (mycp->p_textvp) {
638 		vrele(mycp->p_textvp);
639 		mycp->p_textvp = NULL;
640 	}
641 
642 	/*
643 	 * Allocate and ready the aio control info.  There is one aiop structure
644 	 * per daemon.
645 	 */
646 	aiop = zalloc(aiop_zone);
647 	aiop->aioproc = mycp;
648 	aiop->aioprocflags |= AIOP_FREE;
649 
650 	crit_enter();
651 
652 	/*
653 	 * Place thread (lightweight process) onto the AIO free thread list.
654 	 */
655 	if (TAILQ_EMPTY(&aio_freeproc))
656 		wakeup(&aio_freeproc);
657 	TAILQ_INSERT_HEAD(&aio_freeproc, aiop, list);
658 
659 	crit_exit();
660 
661 	/* Make up a name for the daemon. */
662 	strcpy(mycp->p_comm, "aiod");
663 
664 	/*
665 	 * Get rid of our current filedescriptors.  AIOD's don't need any
666 	 * filedescriptors, except as temporarily inherited from the client.
667 	 * Credentials are also cloned, and made equivalent to "root".
668 	 */
669 	fdfree(mycp, NULL);
670 	cr = cratom(&mycp->p_ucred);
671 	cr->cr_uid = 0;
672 	uireplace(&cr->cr_uidinfo, uifind(0));
673 	cr->cr_ngroups = 1;
674 	cr->cr_groups[0] = 1;
675 
676 	/* The daemon resides in its own pgrp. */
677 	enterpgrp(mycp, mycp->p_pid, 1);
678 
679 	/* Mark special process type. */
680 	mycp->p_flag |= P_SYSTEM | P_KTHREADP;
681 
682 	/*
683 	 * Wakeup parent process.  (Parent sleeps to keep from blasting away
684 	 * and creating too many daemons.)
685 	 */
686 	wakeup(mycp);
687 	curvm = NULL;
688 
689 	for (;;) {
690 		/*
691 		 * Take daemon off of free queue
692 		 */
693 		if (aiop->aioprocflags & AIOP_FREE) {
694 			crit_enter();
695 			TAILQ_REMOVE(&aio_freeproc, aiop, list);
696 			TAILQ_INSERT_TAIL(&aio_activeproc, aiop, list);
697 			aiop->aioprocflags &= ~AIOP_FREE;
698 			crit_exit();
699 		}
700 		aiop->aioprocflags &= ~AIOP_SCHED;
701 
702 		/*
703 		 * Check for jobs.
704 		 */
705 		while ((aiocbe = aio_selectjob(aiop)) != NULL) {
706 			cb = &aiocbe->uaiocb;
707 			userp = aiocbe->userproc;
708 
709 			aiocbe->jobstate = JOBST_JOBRUNNING;
710 
711 			/*
712 			 * Connect to process address space for user program.
713 			 */
714 			if (curvm != userp->p_vmspace) {
715 				pmap_setlwpvm(mylwp, userp->p_vmspace);
716 				if (curvm)
717 					sysref_put(&curvm->vm_sysref);
718 				curvm = userp->p_vmspace;
719 				sysref_get(&curvm->vm_sysref);
720 			}
721 
722 			ki = userp->p_aioinfo;
723 			lj = aiocbe->lio;
724 
725 			/* Account for currently active jobs. */
726 			ki->kaio_active_count++;
727 
728 			/* Do the I/O function. */
729 			aio_process(aiocbe);
730 
731 			/* Decrement the active job count. */
732 			ki->kaio_active_count--;
733 
734 			/*
735 			 * Increment the completion count for wakeup/signal
736 			 * comparisons.
737 			 */
738 			aiocbe->jobflags |= AIOCBLIST_DONE;
739 			ki->kaio_queue_finished_count++;
740 			if (lj)
741 				lj->lioj_queue_finished_count++;
742 			if ((ki->kaio_flags & KAIO_WAKEUP) || ((ki->kaio_flags
743 			    & KAIO_RUNDOWN) && (ki->kaio_active_count == 0))) {
744 				ki->kaio_flags &= ~KAIO_WAKEUP;
745 				wakeup(userp);
746 			}
747 
748 			crit_enter();
749 			if (lj && (lj->lioj_flags &
750 			    (LIOJ_SIGNAL|LIOJ_SIGNAL_POSTED)) == LIOJ_SIGNAL) {
751 				if ((lj->lioj_queue_finished_count ==
752 				    lj->lioj_queue_count) &&
753 				    (lj->lioj_buffer_finished_count ==
754 				    lj->lioj_buffer_count)) {
755 						ksignal(userp,
756 						    lj->lioj_signal.sigev_signo);
757 						lj->lioj_flags |=
758 						    LIOJ_SIGNAL_POSTED;
759 				}
760 			}
761 			crit_exit();
762 
763 			aiocbe->jobstate = JOBST_JOBFINISHED;
764 
765 			crit_enter();
766 			TAILQ_REMOVE(&ki->kaio_jobqueue, aiocbe, plist);
767 			TAILQ_INSERT_TAIL(&ki->kaio_jobdone, aiocbe, plist);
768 			crit_exit();
769 			KNOTE(&aiocbe->klist, 0);
770 
771 			if (aiocbe->jobflags & AIOCBLIST_RUNDOWN) {
772 				wakeup(aiocbe);
773 				aiocbe->jobflags &= ~AIOCBLIST_RUNDOWN;
774 			}
775 
776 			if (cb->aio_sigevent.sigev_notify == SIGEV_SIGNAL) {
777 				ksignal(userp, cb->aio_sigevent.sigev_signo);
778 			}
779 		}
780 
781 		/*
782 		 * Disconnect from user address space.
783 		 */
784 		if (curvm) {
785 			/* swap our original address space back in */
786 			pmap_setlwpvm(mylwp, mycp->p_vmspace);
787 			sysref_put(&curvm->vm_sysref);
788 			curvm = NULL;
789 		}
790 
791 		/*
792 		 * If we are the first to be put onto the free queue, wakeup
793 		 * anyone waiting for a daemon.
794 		 */
795 		crit_enter();
796 		TAILQ_REMOVE(&aio_activeproc, aiop, list);
797 		if (TAILQ_EMPTY(&aio_freeproc))
798 			wakeup(&aio_freeproc);
799 		TAILQ_INSERT_HEAD(&aio_freeproc, aiop, list);
800 		aiop->aioprocflags |= AIOP_FREE;
801 		crit_exit();
802 
803 		/*
804 		 * If daemon is inactive for a long time, allow it to exit,
805 		 * thereby freeing resources.
806 		 */
807 		if (((aiop->aioprocflags & AIOP_SCHED) == 0) && tsleep(mycp,
808 		    0, "aiordy", aiod_lifetime)) {
809 			crit_enter();
810 			if (TAILQ_EMPTY(&aio_jobs)) {
811 				if ((aiop->aioprocflags & AIOP_FREE) &&
812 				    (num_aio_procs > target_aio_procs)) {
813 					TAILQ_REMOVE(&aio_freeproc, aiop, list);
814 					crit_exit();
815 					zfree(aiop_zone, aiop);
816 					num_aio_procs--;
817 #ifdef DIAGNOSTIC
818 					if (mycp->p_vmspace->vm_sysref.refcnt <= 1) {
819 						kprintf("AIOD: bad vm refcnt for"
820 						    " exiting daemon: %d\n",
821 						    mycp->p_vmspace->vm_sysref.refcnt);
822 					}
823 #endif
824 					exit1(0);
825 				}
826 			}
827 			crit_exit();
828 		}
829 	}
830 }
831 
832 /*
833  * Create a new AIO daemon.  This is mostly a kernel-thread fork routine.  The
834  * AIO daemon modifies its environment itself.
835  */
836 static int
837 aio_newproc(void)
838 {
839 	int error;
840 	struct lwp *lp, *nlp;
841 	struct proc *np;
842 
843 	lp = &lwp0;
844 	error = fork1(lp, RFPROC|RFMEM|RFNOWAIT, &np);
845 	if (error)
846 		return error;
847 	nlp = ONLY_LWP_IN_PROC(np);
848 	cpu_set_fork_handler(nlp, aio_daemon, curproc);
849 	start_forked_proc(lp, np);
850 
851 	/*
852 	 * Wait until daemon is started, but continue on just in case to
853 	 * handle error conditions.
854 	 */
855 	error = tsleep(np, 0, "aiosta", aiod_timeout);
856 	num_aio_procs++;
857 
858 	return error;
859 }
860 
861 /*
862  * Try the high-performance, low-overhead physio method for eligible
863  * VCHR devices.  This method doesn't use an aio helper thread, and
864  * thus has very low overhead.
865  *
866  * Assumes that the caller, _aio_aqueue(), has incremented the file
867  * structure's reference count, preventing its deallocation for the
868  * duration of this call.
869  */
870 static int
871 aio_qphysio(struct proc *p, struct aiocblist *aiocbe)
872 {
873 	int error;
874 	struct aiocb *cb;
875 	struct file *fp;
876 	struct buf *bp;
877 	struct vnode *vp;
878 	struct kaioinfo *ki;
879 	struct aio_liojob *lj;
880 	int notify;
881 
882 	cb = &aiocbe->uaiocb;
883 	fp = aiocbe->fd_file;
884 
885 	if (fp->f_type != DTYPE_VNODE)
886 		return (-1);
887 
888 	vp = (struct vnode *)fp->f_data;
889 
890 	/*
891 	 * If its not a disk, we don't want to return a positive error.
892 	 * It causes the aio code to not fall through to try the thread
893 	 * way when you're talking to a regular file.
894 	 */
895 	if (!vn_isdisk(vp, &error)) {
896 		if (error == ENOTBLK)
897 			return (-1);
898 		else
899 			return (error);
900 	}
901 
902  	if (cb->aio_nbytes % vp->v_rdev->si_bsize_phys)
903 		return (-1);
904 
905 	if (cb->aio_nbytes >
906 	    MAXPHYS - (((vm_offset_t) cb->aio_buf) & PAGE_MASK))
907 		return (-1);
908 
909 	ki = p->p_aioinfo;
910 	if (ki->kaio_buffer_count >= ki->kaio_ballowed_count)
911 		return (-1);
912 
913 	ki->kaio_buffer_count++;
914 
915 	lj = aiocbe->lio;
916 	if (lj)
917 		lj->lioj_buffer_count++;
918 
919 	/* Create and build a buffer header for a transfer. */
920 	bp = getpbuf_kva(NULL);
921 	BUF_KERNPROC(bp);
922 
923 	/*
924 	 * Get a copy of the kva from the physical buffer.
925 	 */
926 	bp->b_bio1.bio_caller_info1.ptr = p;
927 	error = 0;
928 
929 	bp->b_cmd = (cb->aio_lio_opcode == LIO_WRITE) ?
930 		    BUF_CMD_WRITE : BUF_CMD_READ;
931 	bp->b_bio1.bio_done = aio_physwakeup;
932 	bp->b_bio1.bio_flags |= BIO_SYNC;
933 	bp->b_bio1.bio_offset = cb->aio_offset;
934 
935 	/* Bring buffer into kernel space. */
936 	if (vmapbuf(bp, __DEVOLATILE(char *, cb->aio_buf), cb->aio_nbytes) < 0) {
937 		error = EFAULT;
938 		goto doerror;
939 	}
940 
941 	crit_enter();
942 
943 	aiocbe->bp = bp;
944 	bp->b_bio1.bio_caller_info2.ptr = aiocbe;
945 	TAILQ_INSERT_TAIL(&aio_bufjobs, aiocbe, list);
946 	TAILQ_INSERT_TAIL(&ki->kaio_bufqueue, aiocbe, plist);
947 	aiocbe->jobstate = JOBST_JOBQBUF;
948 	cb->_aiocb_private.status = cb->aio_nbytes;
949 	num_buf_aio++;
950 	bp->b_error = 0;
951 
952 	crit_exit();
953 
954 	/*
955 	 * Perform the transfer.  vn_strategy must be used even though we
956 	 * know we have a device in order to deal with requests which exceed
957 	 * device DMA limitations.
958 	 */
959 	vn_strategy(vp, &bp->b_bio1);
960 
961 	notify = 0;
962 	crit_enter();
963 
964 #if 0
965 	/*
966 	 * If we had an error invoking the request, or an error in processing
967 	 * the request before we have returned, we process it as an error in
968 	 * transfer.  Note that such an I/O error is not indicated immediately,
969 	 * but is returned using the aio_error mechanism.  In this case,
970 	 * aio_suspend will return immediately.
971 	 */
972 	if (bp->b_error || (bp->b_flags & B_ERROR)) {
973 		struct aiocb *job = aiocbe->uuaiocb;
974 
975 		aiocbe->uaiocb._aiocb_private.status = 0;
976 		suword(&job->_aiocb_private.status, 0);
977 		aiocbe->uaiocb._aiocb_private.error = bp->b_error;
978 		suword(&job->_aiocb_private.error, bp->b_error);
979 
980 		ki->kaio_buffer_finished_count++;
981 
982 		if (aiocbe->jobstate != JOBST_JOBBFINISHED) {
983 			aiocbe->jobstate = JOBST_JOBBFINISHED;
984 			aiocbe->jobflags |= AIOCBLIST_DONE;
985 			TAILQ_REMOVE(&aio_bufjobs, aiocbe, list);
986 			TAILQ_REMOVE(&ki->kaio_bufqueue, aiocbe, plist);
987 			TAILQ_INSERT_TAIL(&ki->kaio_bufdone, aiocbe, plist);
988 			notify = 1;
989 		}
990 	}
991 #endif
992 	crit_exit();
993 	if (notify)
994 		KNOTE(&aiocbe->klist, 0);
995 	return 0;
996 
997 doerror:
998 	ki->kaio_buffer_count--;
999 	if (lj)
1000 		lj->lioj_buffer_count--;
1001 	aiocbe->bp = NULL;
1002 	relpbuf(bp, NULL);
1003 	return error;
1004 }
1005 
1006 /*
1007  * This waits/tests physio completion.
1008  */
1009 static int
1010 aio_fphysio(struct aiocblist *iocb)
1011 {
1012 	struct buf *bp;
1013 	int error;
1014 
1015 	bp = iocb->bp;
1016 
1017 	error = biowait_timeout(&bp->b_bio1, "physstr", aiod_timeout);
1018 	if (error == EWOULDBLOCK)
1019 		return EINPROGRESS;
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 		atomic_clear_int(&so->so_snd.ssb_flags, SSB_AIO);
1054 	} else {
1055 		opcode = LIO_READ;
1056 		atomic_clear_int(&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 file *fp;
1095 	unsigned int fd;
1096 	struct socket *so;
1097 	int error;
1098 	int opcode, user_opcode;
1099 	struct aiocblist *aiocbe;
1100 	struct aioproclist *aiop;
1101 	struct kaioinfo *ki;
1102 	struct kevent kev;
1103 	struct kqueue *kq;
1104 	struct file *kq_fp;
1105 	int fflags;
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 	/*
1143 	 * Range check file descriptor.
1144 	 */
1145 	fflags = (opcode == LIO_WRITE) ? FWRITE : FREAD;
1146 	fd = aiocbe->uaiocb.aio_fildes;
1147 	fp = holdfp(p->p_fd, fd, fflags);
1148 	if (fp == NULL) {
1149 		TAILQ_INSERT_HEAD(&aio_freejobs, aiocbe, list);
1150 		if (type == 0)
1151 			suword(&job->_aiocb_private.error, EBADF);
1152 		return EBADF;
1153 	}
1154 
1155 	aiocbe->fd_file = fp;
1156 
1157 	if (aiocbe->uaiocb.aio_offset == -1LL) {
1158 		error = EINVAL;
1159 		goto aqueue_fail;
1160 	}
1161 	error = suword(&job->_aiocb_private.kernelinfo, jobrefid);
1162 	if (error) {
1163 		error = EINVAL;
1164 		goto aqueue_fail;
1165 	}
1166 	aiocbe->uaiocb._aiocb_private.kernelinfo = (void *)(intptr_t)jobrefid;
1167 	if (jobrefid == LONG_MAX)
1168 		jobrefid = 1;
1169 	else
1170 		jobrefid++;
1171 
1172 	if (opcode == LIO_NOP) {
1173 		fdrop(fp);
1174 		TAILQ_INSERT_HEAD(&aio_freejobs, aiocbe, list);
1175 		if (type == 0) {
1176 			suword(&job->_aiocb_private.error, 0);
1177 			suword(&job->_aiocb_private.status, 0);
1178 			suword(&job->_aiocb_private.kernelinfo, 0);
1179 		}
1180 		return 0;
1181 	}
1182 	if ((opcode != LIO_READ) && (opcode != LIO_WRITE)) {
1183 		if (type == 0)
1184 			suword(&job->_aiocb_private.status, 0);
1185 		error = EINVAL;
1186 		goto aqueue_fail;
1187 	}
1188 
1189 	if (aiocbe->uaiocb.aio_sigevent.sigev_notify == SIGEV_KEVENT) {
1190 		kev.ident = aiocbe->uaiocb.aio_sigevent.sigev_notify_kqueue;
1191 		kev.udata = aiocbe->uaiocb.aio_sigevent.sigev_value.sival_ptr;
1192 	}
1193 	else {
1194 		/*
1195 		 * This method for requesting kevent-based notification won't
1196 		 * work on the alpha, since we're passing in a pointer
1197 		 * via aio_lio_opcode, which is an int.  Use the SIGEV_KEVENT-
1198 		 * based method instead.
1199 		 */
1200 		if (user_opcode == LIO_NOP || user_opcode == LIO_READ ||
1201 		    user_opcode == LIO_WRITE)
1202 			goto no_kqueue;
1203 
1204 		error = copyin((struct kevent *)(uintptr_t)user_opcode,
1205 		    &kev, sizeof(kev));
1206 		if (error)
1207 			goto aqueue_fail;
1208 	}
1209 	kq_fp = holdfp(p->p_fd, (int)kev.ident, -1);
1210 	if (kq_fp == NULL || kq_fp->f_type != DTYPE_KQUEUE) {
1211 		if (kq_fp) {
1212 			fdrop(kq_fp);
1213 			kq_fp = NULL;
1214 		}
1215 		error = EBADF;
1216 		goto aqueue_fail;
1217 	}
1218 	kq = (struct kqueue *)kq_fp->f_data;
1219 	kev.ident = (uintptr_t)aiocbe->uuaiocb;
1220 	kev.filter = EVFILT_AIO;
1221 	kev.flags = EV_ADD | EV_ENABLE | EV_FLAG1;
1222 	kev.data = (intptr_t)aiocbe;
1223 	error = kqueue_register(kq, &kev);
1224 	fdrop(kq_fp);
1225 aqueue_fail:
1226 	if (error) {
1227 		fdrop(fp);
1228 		TAILQ_INSERT_HEAD(&aio_freejobs, aiocbe, list);
1229 		if (type == 0)
1230 			suword(&job->_aiocb_private.error, error);
1231 		goto done;
1232 	}
1233 no_kqueue:
1234 
1235 	suword(&job->_aiocb_private.error, EINPROGRESS);
1236 	aiocbe->uaiocb._aiocb_private.error = EINPROGRESS;
1237 	aiocbe->userproc = p;
1238 	aiocbe->jobflags = 0;
1239 	aiocbe->lio = lj;
1240 	ki = p->p_aioinfo;
1241 
1242 	if (fp->f_type == DTYPE_SOCKET) {
1243 		/*
1244 		 * Alternate queueing for socket ops: Reach down into the
1245 		 * descriptor to get the socket data.  Then check to see if the
1246 		 * socket is ready to be read or written (based on the requested
1247 		 * operation).
1248 		 *
1249 		 * If it is not ready for io, then queue the aiocbe on the
1250 		 * socket, and set the flags so we get a call when ssb_notify()
1251 		 * happens.
1252 		 */
1253 		so = (struct socket *)fp->f_data;
1254 		crit_enter();
1255 		if (((opcode == LIO_READ) && (!soreadable(so))) || ((opcode ==
1256 		    LIO_WRITE) && (!sowriteable(so)))) {
1257 			TAILQ_INSERT_TAIL(&so->so_aiojobq, aiocbe, list);
1258 			TAILQ_INSERT_TAIL(&ki->kaio_sockqueue, aiocbe, plist);
1259 			if (opcode == LIO_READ)
1260 				atomic_set_int(&so->so_rcv.ssb_flags, SSB_AIO);
1261 			else
1262 				atomic_set_int(&so->so_snd.ssb_flags, SSB_AIO);
1263 			aiocbe->jobstate = JOBST_JOBQGLOBAL; /* XXX */
1264 			ki->kaio_queue_count++;
1265 			num_queue_count++;
1266 			crit_exit();
1267 			error = 0;
1268 			goto done;
1269 		}
1270 		crit_exit();
1271 	}
1272 
1273 	if ((error = aio_qphysio(p, aiocbe)) == 0)
1274 		goto done;
1275 	if (error > 0) {
1276 		suword(&job->_aiocb_private.status, 0);
1277 		aiocbe->uaiocb._aiocb_private.error = error;
1278 		suword(&job->_aiocb_private.error, error);
1279 		goto done;
1280 	}
1281 
1282 	/* No buffer for daemon I/O. */
1283 	aiocbe->bp = NULL;
1284 
1285 	ki->kaio_queue_count++;
1286 	if (lj)
1287 		lj->lioj_queue_count++;
1288 	crit_enter();
1289 	TAILQ_INSERT_TAIL(&ki->kaio_jobqueue, aiocbe, plist);
1290 	TAILQ_INSERT_TAIL(&aio_jobs, aiocbe, list);
1291 	crit_exit();
1292 	aiocbe->jobstate = JOBST_JOBQGLOBAL;
1293 
1294 	num_queue_count++;
1295 	error = 0;
1296 
1297 	/*
1298 	 * If we don't have a free AIO process, and we are below our quota, then
1299 	 * start one.  Otherwise, depend on the subsequent I/O completions to
1300 	 * pick-up this job.  If we don't successfully create the new process
1301 	 * (thread) due to resource issues, we return an error for now (EAGAIN),
1302 	 * which is likely not the correct thing to do.
1303 	 */
1304 	crit_enter();
1305 retryproc:
1306 	if ((aiop = TAILQ_FIRST(&aio_freeproc)) != NULL) {
1307 		TAILQ_REMOVE(&aio_freeproc, aiop, list);
1308 		TAILQ_INSERT_TAIL(&aio_activeproc, aiop, list);
1309 		aiop->aioprocflags &= ~AIOP_FREE;
1310 		wakeup(aiop->aioproc);
1311 	} else if (((num_aio_resv_start + num_aio_procs) < max_aio_procs) &&
1312 	    ((ki->kaio_active_count + num_aio_resv_start) <
1313 	    ki->kaio_maxactive_count)) {
1314 		num_aio_resv_start++;
1315 		if ((error = aio_newproc()) == 0) {
1316 			num_aio_resv_start--;
1317 			goto retryproc;
1318 		}
1319 		num_aio_resv_start--;
1320 	}
1321 	crit_exit();
1322 done:
1323 	return error;
1324 }
1325 
1326 /*
1327  * This routine queues an AIO request, checking for quotas.
1328  */
1329 static int
1330 aio_aqueue(struct aiocb *job, int type)
1331 {
1332 	struct proc *p = curproc;
1333 	struct kaioinfo *ki;
1334 
1335 	if (p->p_aioinfo == NULL)
1336 		aio_init_aioinfo(p);
1337 
1338 	if (num_queue_count >= max_queue_count)
1339 		return EAGAIN;
1340 
1341 	ki = p->p_aioinfo;
1342 	if (ki->kaio_queue_count >= ki->kaio_qallowed_count)
1343 		return EAGAIN;
1344 
1345 	return _aio_aqueue(job, NULL, type);
1346 }
1347 #endif /* VFS_AIO */
1348 
1349 /*
1350  * Support the aio_return system call, as a side-effect, kernel resources are
1351  * released.
1352  *
1353  * MPALMOSTSAFE
1354  */
1355 int
1356 sys_aio_return(struct aio_return_args *uap)
1357 {
1358 #ifndef VFS_AIO
1359 	return (ENOSYS);
1360 #else
1361 	struct proc *p = curproc;
1362 	struct lwp *lp = curthread->td_lwp;
1363 	long jobref;
1364 	struct aiocblist *cb, *ncb;
1365 	struct aiocb *ujob;
1366 	struct kaioinfo *ki;
1367 	int error;
1368 
1369 	ki = p->p_aioinfo;
1370 	if (ki == NULL)
1371 		return EINVAL;
1372 
1373 	ujob = uap->aiocbp;
1374 
1375 	jobref = fuword(&ujob->_aiocb_private.kernelinfo);
1376 	if (jobref == -1 || jobref == 0)
1377 		return EINVAL;
1378 
1379 	get_mplock();
1380 	TAILQ_FOREACH(cb, &ki->kaio_jobdone, plist) {
1381 		if (((intptr_t) cb->uaiocb._aiocb_private.kernelinfo) ==
1382 		    jobref) {
1383 			if (ujob == cb->uuaiocb) {
1384 				uap->sysmsg_result =
1385 				    cb->uaiocb._aiocb_private.status;
1386 			} else {
1387 				uap->sysmsg_result = EFAULT;
1388 			}
1389 			if (cb->uaiocb.aio_lio_opcode == LIO_WRITE) {
1390 				lp->lwp_ru.ru_oublock += cb->outputcharge;
1391 				cb->outputcharge = 0;
1392 			} else if (cb->uaiocb.aio_lio_opcode == LIO_READ) {
1393 				lp->lwp_ru.ru_inblock += cb->inputcharge;
1394 				cb->inputcharge = 0;
1395 			}
1396 			aio_free_entry(cb);
1397 			error = 0;
1398 			goto done;
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 			}
1413 			aio_free_entry(cb);
1414 			error = 0;
1415 			goto done;
1416 		}
1417 	}
1418 	crit_exit();
1419 	error = EINVAL;
1420 done:
1421 	rel_mplock();
1422 	return (error);
1423 #endif /* VFS_AIO */
1424 }
1425 
1426 /*
1427  * Allow a process to wakeup when any of the I/O requests are completed.
1428  *
1429  * MPALMOSTSAFE
1430  */
1431 int
1432 sys_aio_suspend(struct aio_suspend_args *uap)
1433 {
1434 #ifndef VFS_AIO
1435 	return ENOSYS;
1436 #else
1437 	struct proc *p = curproc;
1438 	struct timeval atv;
1439 	struct timespec ts;
1440 	struct aiocb *const *cbptr, *cbp;
1441 	struct kaioinfo *ki;
1442 	struct aiocblist *cb;
1443 	int i;
1444 	int njoblist;
1445 	int error, timo;
1446 	long *ijoblist;
1447 	struct aiocb **ujoblist;
1448 
1449 	if ((u_int)uap->nent > AIO_LISTIO_MAX)
1450 		return EINVAL;
1451 
1452 	timo = 0;
1453 	if (uap->timeout) {
1454 		/* Get timespec struct. */
1455 		if ((error = copyin(uap->timeout, &ts, sizeof(ts))) != 0)
1456 			return error;
1457 
1458 		if (ts.tv_nsec < 0 || ts.tv_nsec >= 1000000000)
1459 			return (EINVAL);
1460 
1461 		TIMESPEC_TO_TIMEVAL(&atv, &ts);
1462 		if (itimerfix(&atv))
1463 			return (EINVAL);
1464 		timo = tvtohz_high(&atv);
1465 	}
1466 
1467 	ki = p->p_aioinfo;
1468 	if (ki == NULL)
1469 		return EAGAIN;
1470 
1471 	get_mplock();
1472 
1473 	njoblist = 0;
1474 	ijoblist = zalloc(aiol_zone);
1475 	ujoblist = zalloc(aiol_zone);
1476 	cbptr = uap->aiocbp;
1477 
1478 	for (i = 0; i < uap->nent; i++) {
1479 		cbp = (struct aiocb *)(intptr_t)fuword(&cbptr[i]);
1480 		if (cbp == 0)
1481 			continue;
1482 		ujoblist[njoblist] = cbp;
1483 		ijoblist[njoblist] = fuword(&cbp->_aiocb_private.kernelinfo);
1484 		njoblist++;
1485 	}
1486 
1487 	if (njoblist == 0) {
1488 		zfree(aiol_zone, ijoblist);
1489 		zfree(aiol_zone, ujoblist);
1490 		error = 0;
1491 		goto done;
1492 	}
1493 
1494 	error = 0;
1495 	for (;;) {
1496 		TAILQ_FOREACH(cb, &ki->kaio_jobdone, plist) {
1497 			for (i = 0; i < njoblist; i++) {
1498 				if (((intptr_t)
1499 				    cb->uaiocb._aiocb_private.kernelinfo) ==
1500 				    ijoblist[i]) {
1501 					if (ujoblist[i] != cb->uuaiocb)
1502 						error = EINVAL;
1503 					zfree(aiol_zone, ijoblist);
1504 					zfree(aiol_zone, ujoblist);
1505 					goto done;
1506 				}
1507 			}
1508 		}
1509 
1510 		crit_enter();
1511 		for (cb = TAILQ_FIRST(&ki->kaio_bufdone); cb; cb =
1512 		    TAILQ_NEXT(cb, plist)) {
1513 			for (i = 0; i < njoblist; i++) {
1514 				if (((intptr_t)
1515 				    cb->uaiocb._aiocb_private.kernelinfo) ==
1516 				    ijoblist[i]) {
1517 					crit_exit();
1518 					if (ujoblist[i] != cb->uuaiocb)
1519 						error = EINVAL;
1520 					zfree(aiol_zone, ijoblist);
1521 					zfree(aiol_zone, ujoblist);
1522 					goto done;
1523 				}
1524 			}
1525 		}
1526 
1527 		ki->kaio_flags |= KAIO_WAKEUP;
1528 		error = tsleep(p, PCATCH, "aiospn", timo);
1529 		crit_exit();
1530 
1531 		if (error == ERESTART || error == EINTR) {
1532 			zfree(aiol_zone, ijoblist);
1533 			zfree(aiol_zone, ujoblist);
1534 			error = EINTR;
1535 			goto done;
1536 		} else if (error == EWOULDBLOCK) {
1537 			zfree(aiol_zone, ijoblist);
1538 			zfree(aiol_zone, ujoblist);
1539 			error = EAGAIN;
1540 			goto done;
1541 		}
1542 	}
1543 
1544 /* NOTREACHED */
1545 	error = EINVAL;
1546 done:
1547 	rel_mplock();
1548 	return (error);
1549 #endif /* VFS_AIO */
1550 }
1551 
1552 /*
1553  * aio_cancel cancels any non-physio aio operations not currently in
1554  * progress.
1555  *
1556  * MPALMOSTSAFE
1557  */
1558 int
1559 sys_aio_cancel(struct aio_cancel_args *uap)
1560 {
1561 #ifndef VFS_AIO
1562 	return ENOSYS;
1563 #else
1564 	struct proc *p = curproc;
1565 	struct kaioinfo *ki;
1566 	struct aiocblist *cbe, *cbn;
1567 	struct file *fp;
1568 	struct socket *so;
1569 	struct proc *po;
1570 	int error;
1571 	int cancelled=0;
1572 	int notcancelled=0;
1573 	struct vnode *vp;
1574 
1575 	fp = holdfp(p->p_fd, uap->fd, -1);
1576 	if (fp == NULL)
1577 		return (EBADF);
1578 
1579 	get_mplock();
1580 
1581         if (fp->f_type == DTYPE_VNODE) {
1582 		vp = (struct vnode *)fp->f_data;
1583 
1584 		if (vn_isdisk(vp,&error)) {
1585 			uap->sysmsg_result = AIO_NOTCANCELED;
1586 			error = 0;
1587 			goto done2;
1588 		}
1589 	} else if (fp->f_type == DTYPE_SOCKET) {
1590 		so = (struct socket *)fp->f_data;
1591 
1592 		crit_enter();
1593 
1594 		for (cbe = TAILQ_FIRST(&so->so_aiojobq); cbe; cbe = cbn) {
1595 			cbn = TAILQ_NEXT(cbe, list);
1596 			if ((uap->aiocbp == NULL) ||
1597 				(uap->aiocbp == cbe->uuaiocb) ) {
1598 				po = cbe->userproc;
1599 				ki = po->p_aioinfo;
1600 				TAILQ_REMOVE(&so->so_aiojobq, cbe, list);
1601 				TAILQ_REMOVE(&ki->kaio_sockqueue, cbe, plist);
1602 				TAILQ_INSERT_TAIL(&ki->kaio_jobdone, cbe, plist);
1603 				if (ki->kaio_flags & KAIO_WAKEUP) {
1604 					wakeup(po);
1605 				}
1606 				cbe->jobstate = JOBST_JOBFINISHED;
1607 				cbe->uaiocb._aiocb_private.status=-1;
1608 				cbe->uaiocb._aiocb_private.error=ECANCELED;
1609 				cancelled++;
1610 /* XXX cancelled, knote? */
1611 			        if (cbe->uaiocb.aio_sigevent.sigev_notify ==
1612 				    SIGEV_SIGNAL)
1613 					ksignal(cbe->userproc, cbe->uaiocb.aio_sigevent.sigev_signo);
1614 				if (uap->aiocbp)
1615 					break;
1616 			}
1617 		}
1618 		crit_exit();
1619 
1620 		if ((cancelled) && (uap->aiocbp)) {
1621 			uap->sysmsg_result = AIO_CANCELED;
1622 			error = 0;
1623 			goto done2;
1624 		}
1625 	}
1626 	ki=p->p_aioinfo;
1627 	if (ki == NULL)
1628 		goto done;
1629 	crit_enter();
1630 
1631 	for (cbe = TAILQ_FIRST(&ki->kaio_jobqueue); cbe; cbe = cbn) {
1632 		cbn = TAILQ_NEXT(cbe, plist);
1633 
1634 		if ((uap->fd == cbe->uaiocb.aio_fildes) &&
1635 		    ((uap->aiocbp == NULL ) ||
1636 		     (uap->aiocbp == cbe->uuaiocb))) {
1637 
1638 			if (cbe->jobstate == JOBST_JOBQGLOBAL) {
1639 				TAILQ_REMOVE(&aio_jobs, cbe, list);
1640                                 TAILQ_REMOVE(&ki->kaio_jobqueue, cbe, plist);
1641                                 TAILQ_INSERT_TAIL(&ki->kaio_jobdone, cbe,
1642                                     plist);
1643 				cancelled++;
1644 				ki->kaio_queue_finished_count++;
1645 				cbe->jobstate = JOBST_JOBFINISHED;
1646 				cbe->uaiocb._aiocb_private.status = -1;
1647 				cbe->uaiocb._aiocb_private.error = ECANCELED;
1648 /* XXX cancelled, knote? */
1649 			        if (cbe->uaiocb.aio_sigevent.sigev_notify ==
1650 				    SIGEV_SIGNAL)
1651 					ksignal(cbe->userproc, cbe->uaiocb.aio_sigevent.sigev_signo);
1652 			} else {
1653 				notcancelled++;
1654 			}
1655 		}
1656 	}
1657 	crit_exit();
1658 done:
1659 	if (notcancelled)
1660 		uap->sysmsg_result = AIO_NOTCANCELED;
1661 	else if (cancelled)
1662 		uap->sysmsg_result = AIO_CANCELED;
1663 	else
1664 		uap->sysmsg_result = AIO_ALLDONE;
1665 	error = 0;
1666 done2:
1667 	rel_mplock();
1668 	fdrop(fp);
1669 	return error;
1670 #endif /* VFS_AIO */
1671 }
1672 
1673 /*
1674  * aio_error is implemented in the kernel level for compatibility purposes only.
1675  * For a user mode async implementation, it would be best to do it in a userland
1676  * subroutine.
1677  *
1678  * MPALMOSTSAFE
1679  */
1680 int
1681 sys_aio_error(struct aio_error_args *uap)
1682 {
1683 #ifndef VFS_AIO
1684 	return ENOSYS;
1685 #else
1686 	struct proc *p = curproc;
1687 	struct aiocblist *cb;
1688 	struct kaioinfo *ki;
1689 	long jobref;
1690 	int error;
1691 
1692 	ki = p->p_aioinfo;
1693 	if (ki == NULL)
1694 		return EINVAL;
1695 
1696 	jobref = fuword(&uap->aiocbp->_aiocb_private.kernelinfo);
1697 	if ((jobref == -1) || (jobref == 0))
1698 		return EINVAL;
1699 
1700 	get_mplock();
1701 	error = 0;
1702 
1703 	TAILQ_FOREACH(cb, &ki->kaio_jobdone, plist) {
1704 		if (((intptr_t)cb->uaiocb._aiocb_private.kernelinfo) ==
1705 		    jobref) {
1706 			uap->sysmsg_result = cb->uaiocb._aiocb_private.error;
1707 			goto done;
1708 		}
1709 	}
1710 
1711 	crit_enter();
1712 
1713 	for (cb = TAILQ_FIRST(&ki->kaio_jobqueue); cb; cb = TAILQ_NEXT(cb,
1714 	    plist)) {
1715 		if (((intptr_t)cb->uaiocb._aiocb_private.kernelinfo) ==
1716 		    jobref) {
1717 			uap->sysmsg_result = EINPROGRESS;
1718 			crit_exit();
1719 			goto done;
1720 		}
1721 	}
1722 
1723 	for (cb = TAILQ_FIRST(&ki->kaio_sockqueue); cb; cb = TAILQ_NEXT(cb,
1724 	    plist)) {
1725 		if (((intptr_t)cb->uaiocb._aiocb_private.kernelinfo) ==
1726 		    jobref) {
1727 			uap->sysmsg_result = EINPROGRESS;
1728 			crit_exit();
1729 			goto done;
1730 		}
1731 	}
1732 	crit_exit();
1733 
1734 	crit_enter();
1735 	for (cb = TAILQ_FIRST(&ki->kaio_bufdone); cb; cb = TAILQ_NEXT(cb,
1736 	    plist)) {
1737 		if (((intptr_t)cb->uaiocb._aiocb_private.kernelinfo) ==
1738 		    jobref) {
1739 			uap->sysmsg_result = cb->uaiocb._aiocb_private.error;
1740 			crit_exit();
1741 			goto done;
1742 		}
1743 	}
1744 
1745 	for (cb = TAILQ_FIRST(&ki->kaio_bufqueue); cb; cb = TAILQ_NEXT(cb,
1746 	    plist)) {
1747 		if (((intptr_t)cb->uaiocb._aiocb_private.kernelinfo) ==
1748 		    jobref) {
1749 			uap->sysmsg_result = EINPROGRESS;
1750 			crit_exit();
1751 			goto done;
1752 		}
1753 	}
1754 	crit_exit();
1755 	error = EINVAL;
1756 done:
1757 	rel_mplock();
1758 	return (error);
1759 #endif /* VFS_AIO */
1760 }
1761 
1762 /*
1763  * syscall - asynchronous read from a file (REALTIME)
1764  *
1765  * MPALMOSTSAFE
1766  */
1767 int
1768 sys_aio_read(struct aio_read_args *uap)
1769 {
1770 #ifndef VFS_AIO
1771 	return ENOSYS;
1772 #else
1773 	int error;
1774 
1775 	get_mplock();
1776 	error =  aio_aqueue(uap->aiocbp, LIO_READ);
1777 	rel_mplock();
1778 	return (error);
1779 #endif /* VFS_AIO */
1780 }
1781 
1782 /*
1783  * syscall - asynchronous write to a file (REALTIME)
1784  *
1785  * MPALMOSTSAFE
1786  */
1787 int
1788 sys_aio_write(struct aio_write_args *uap)
1789 {
1790 #ifndef VFS_AIO
1791 	return ENOSYS;
1792 #else
1793 	int error;
1794 
1795 	get_mplock();
1796 	error = aio_aqueue(uap->aiocbp, LIO_WRITE);
1797 	rel_mplock();
1798 	return (error);
1799 #endif /* VFS_AIO */
1800 }
1801 
1802 /*
1803  * syscall - XXX undocumented
1804  *
1805  * MPALMOSTSAFE
1806  */
1807 int
1808 sys_lio_listio(struct lio_listio_args *uap)
1809 {
1810 #ifndef VFS_AIO
1811 	return ENOSYS;
1812 #else
1813 	struct proc *p = curproc;
1814 	struct lwp *lp = curthread->td_lwp;
1815 	int nent, nentqueued;
1816 	struct aiocb *iocb, * const *cbptr;
1817 	struct aiocblist *cb;
1818 	struct kaioinfo *ki;
1819 	struct aio_liojob *lj;
1820 	int error, runningcode;
1821 	int nerror;
1822 	int i;
1823 
1824 	if ((uap->mode != LIO_NOWAIT) && (uap->mode != LIO_WAIT))
1825 		return EINVAL;
1826 
1827 	nent = uap->nent;
1828 	if (nent > AIO_LISTIO_MAX)
1829 		return EINVAL;
1830 
1831 	get_mplock();
1832 
1833 	if (p->p_aioinfo == NULL)
1834 		aio_init_aioinfo(p);
1835 
1836 	if ((nent + num_queue_count) > max_queue_count) {
1837 		error = EAGAIN;
1838 		goto done;
1839 	}
1840 
1841 	ki = p->p_aioinfo;
1842 	if ((nent + ki->kaio_queue_count) > ki->kaio_qallowed_count) {
1843 		error = EAGAIN;
1844 		goto done;
1845 	}
1846 
1847 	lj = zalloc(aiolio_zone);
1848 	if (lj == NULL) {
1849 		error = EAGAIN;
1850 		goto done;
1851 	}
1852 
1853 	lj->lioj_flags = 0;
1854 	lj->lioj_buffer_count = 0;
1855 	lj->lioj_buffer_finished_count = 0;
1856 	lj->lioj_queue_count = 0;
1857 	lj->lioj_queue_finished_count = 0;
1858 	lj->lioj_ki = ki;
1859 
1860 	/*
1861 	 * Setup signal.
1862 	 */
1863 	if (uap->sig && (uap->mode == LIO_NOWAIT)) {
1864 		error = copyin(uap->sig, &lj->lioj_signal,
1865 		    sizeof(lj->lioj_signal));
1866 		if (error) {
1867 			zfree(aiolio_zone, lj);
1868 			goto done;
1869 		}
1870 		if (!_SIG_VALID(lj->lioj_signal.sigev_signo)) {
1871 			zfree(aiolio_zone, lj);
1872 			error = EINVAL;
1873 			goto done;
1874 		}
1875 		lj->lioj_flags |= LIOJ_SIGNAL;
1876 		lj->lioj_flags &= ~LIOJ_SIGNAL_POSTED;
1877 	} else
1878 		lj->lioj_flags &= ~LIOJ_SIGNAL;
1879 
1880 	TAILQ_INSERT_TAIL(&ki->kaio_liojoblist, lj, lioj_list);
1881 	/*
1882 	 * Get pointers to the list of I/O requests.
1883 	 */
1884 	nerror = 0;
1885 	nentqueued = 0;
1886 	cbptr = uap->acb_list;
1887 	for (i = 0; i < uap->nent; i++) {
1888 		iocb = (struct aiocb *)(intptr_t)fuword(&cbptr[i]);
1889 		if (((intptr_t)iocb != -1) && ((intptr_t)iocb != 0)) {
1890 			error = _aio_aqueue(iocb, lj, 0);
1891 			if (error == 0)
1892 				nentqueued++;
1893 			else
1894 				nerror++;
1895 		}
1896 	}
1897 
1898 	/*
1899 	 * If we haven't queued any, then just return error.
1900 	 */
1901 	if (nentqueued == 0) {
1902 		error = 0;
1903 		goto done;
1904 	}
1905 
1906 	/*
1907 	 * Calculate the appropriate error return.
1908 	 */
1909 	runningcode = 0;
1910 	if (nerror)
1911 		runningcode = EIO;
1912 
1913 	if (uap->mode == LIO_WAIT) {
1914 		int command, found, jobref;
1915 
1916 		for (;;) {
1917 			found = 0;
1918 			for (i = 0; i < uap->nent; i++) {
1919 				/*
1920 				 * Fetch address of the control buf pointer in
1921 				 * user space.
1922 				 */
1923 				iocb = (struct aiocb *)
1924 				    (intptr_t)fuword(&cbptr[i]);
1925 				if (((intptr_t)iocb == -1) || ((intptr_t)iocb
1926 				    == 0))
1927 					continue;
1928 
1929 				/*
1930 				 * Fetch the associated command from user space.
1931 				 */
1932 				command = fuword(&iocb->aio_lio_opcode);
1933 				if (command == LIO_NOP) {
1934 					found++;
1935 					continue;
1936 				}
1937 
1938 				jobref = fuword(&iocb->_aiocb_private.kernelinfo);
1939 
1940 				TAILQ_FOREACH(cb, &ki->kaio_jobdone, plist) {
1941 					if (((intptr_t)cb->uaiocb._aiocb_private.kernelinfo)
1942 					    == jobref) {
1943 						if (cb->uaiocb.aio_lio_opcode
1944 						    == LIO_WRITE) {
1945 							lp->lwp_ru.ru_oublock +=
1946 							    cb->outputcharge;
1947 							cb->outputcharge = 0;
1948 						} else if (cb->uaiocb.aio_lio_opcode
1949 						    == LIO_READ) {
1950 							lp->lwp_ru.ru_inblock +=
1951 							    cb->inputcharge;
1952 							cb->inputcharge = 0;
1953 						}
1954 						found++;
1955 						break;
1956 					}
1957 				}
1958 
1959 				crit_enter();
1960 				TAILQ_FOREACH(cb, &ki->kaio_bufdone, plist) {
1961 					if (((intptr_t)cb->uaiocb._aiocb_private.kernelinfo)
1962 					    == jobref) {
1963 						found++;
1964 						break;
1965 					}
1966 				}
1967 				crit_exit();
1968 			}
1969 
1970 			/*
1971 			 * If all I/Os have been disposed of, then we can
1972 			 * return.
1973 			 */
1974 			if (found == nentqueued) {
1975 				error = runningcode;
1976 				goto done;
1977 			}
1978 
1979 			ki->kaio_flags |= KAIO_WAKEUP;
1980 			error = tsleep(p, PCATCH, "aiospn", 0);
1981 
1982 			if (error == EINTR) {
1983 				goto done;
1984 			} else if (error == EWOULDBLOCK) {
1985 				error = EAGAIN;
1986 				goto done;
1987 			}
1988 		}
1989 	}
1990 
1991 	error = runningcode;
1992 done:
1993 	rel_mplock();
1994 	return (error);
1995 #endif /* VFS_AIO */
1996 }
1997 
1998 #ifdef VFS_AIO
1999 /*
2000  * This is a weird hack so that we can post a signal.  It is safe to do so from
2001  * a timeout routine, but *not* from an interrupt routine.
2002  */
2003 static void
2004 process_signal(void *aioj)
2005 {
2006 	struct aiocblist *aiocbe = aioj;
2007 	struct aio_liojob *lj = aiocbe->lio;
2008 	struct aiocb *cb = &aiocbe->uaiocb;
2009 
2010 	if ((lj) && (lj->lioj_signal.sigev_notify == SIGEV_SIGNAL) &&
2011 	    (lj->lioj_queue_count == lj->lioj_queue_finished_count)) {
2012 		ksignal(lj->lioj_ki->kaio_p, lj->lioj_signal.sigev_signo);
2013 		lj->lioj_flags |= LIOJ_SIGNAL_POSTED;
2014 	}
2015 
2016 	if (cb->aio_sigevent.sigev_notify == SIGEV_SIGNAL)
2017 		ksignal(aiocbe->userproc, cb->aio_sigevent.sigev_signo);
2018 }
2019 
2020 /*
2021  * Interrupt handler for physio, performs the necessary process wakeups, and
2022  * signals.
2023  */
2024 static void
2025 aio_physwakeup(struct bio *bio)
2026 {
2027 	struct buf *bp = bio->bio_buf;
2028 	struct aiocblist *aiocbe;
2029 	struct proc *p;
2030 	struct kaioinfo *ki;
2031 	struct aio_liojob *lj;
2032 
2033 	aiocbe = bio->bio_caller_info2.ptr;
2034 	get_mplock();
2035 
2036 	if (aiocbe) {
2037 		p = bio->bio_caller_info1.ptr;
2038 
2039 		aiocbe->jobstate = JOBST_JOBBFINISHED;
2040 		aiocbe->uaiocb._aiocb_private.status -= bp->b_resid;
2041 		aiocbe->uaiocb._aiocb_private.error = 0;
2042 		aiocbe->jobflags |= AIOCBLIST_DONE;
2043 
2044 		if (bp->b_flags & B_ERROR)
2045 			aiocbe->uaiocb._aiocb_private.error = bp->b_error;
2046 
2047 		lj = aiocbe->lio;
2048 		if (lj) {
2049 			lj->lioj_buffer_finished_count++;
2050 
2051 			/*
2052 			 * wakeup/signal if all of the interrupt jobs are done.
2053 			 */
2054 			if (lj->lioj_buffer_finished_count ==
2055 			    lj->lioj_buffer_count) {
2056 				/*
2057 				 * Post a signal if it is called for.
2058 				 */
2059 				if ((lj->lioj_flags &
2060 				    (LIOJ_SIGNAL|LIOJ_SIGNAL_POSTED)) ==
2061 				    LIOJ_SIGNAL) {
2062 					lj->lioj_flags |= LIOJ_SIGNAL_POSTED;
2063 					callout_reset(&aiocbe->timeout, 0,
2064 							process_signal, aiocbe);
2065 				}
2066 			}
2067 		}
2068 
2069 		ki = p->p_aioinfo;
2070 		if (ki) {
2071 			ki->kaio_buffer_finished_count++;
2072 			TAILQ_REMOVE(&aio_bufjobs, aiocbe, list);
2073 			TAILQ_REMOVE(&ki->kaio_bufqueue, aiocbe, plist);
2074 			TAILQ_INSERT_TAIL(&ki->kaio_bufdone, aiocbe, plist);
2075 
2076 			KNOTE(&aiocbe->klist, 0);
2077 			/* Do the wakeup. */
2078 			if (ki->kaio_flags & (KAIO_RUNDOWN|KAIO_WAKEUP)) {
2079 				ki->kaio_flags &= ~KAIO_WAKEUP;
2080 				wakeup(p);
2081 			}
2082 		}
2083 
2084 		if (aiocbe->uaiocb.aio_sigevent.sigev_notify == SIGEV_SIGNAL) {
2085 			callout_reset(&aiocbe->timeout, 0,
2086 					process_signal, aiocbe);
2087 		}
2088 	}
2089 	biodone_sync(bio);
2090 	rel_mplock();
2091 }
2092 #endif /* VFS_AIO */
2093 
2094 /*
2095  * syscall - wait for the next completion of an aio request
2096  *
2097  * MPALMOSTSAFE
2098  */
2099 int
2100 sys_aio_waitcomplete(struct aio_waitcomplete_args *uap)
2101 {
2102 #ifndef VFS_AIO
2103 	return ENOSYS;
2104 #else
2105 	struct proc *p = curproc;
2106 	struct lwp *lp = curthread->td_lwp;
2107 	struct timeval atv;
2108 	struct timespec ts;
2109 	struct kaioinfo *ki;
2110 	struct aiocblist *cb = NULL;
2111 	int error, timo;
2112 
2113 	suword(uap->aiocbp, (int)NULL);
2114 
2115 	timo = 0;
2116 	if (uap->timeout) {
2117 		/* Get timespec struct. */
2118 		error = copyin(uap->timeout, &ts, sizeof(ts));
2119 		if (error)
2120 			return error;
2121 
2122 		if ((ts.tv_nsec < 0) || (ts.tv_nsec >= 1000000000))
2123 			return (EINVAL);
2124 
2125 		TIMESPEC_TO_TIMEVAL(&atv, &ts);
2126 		if (itimerfix(&atv))
2127 			return (EINVAL);
2128 		timo = tvtohz_high(&atv);
2129 	}
2130 
2131 	ki = p->p_aioinfo;
2132 	if (ki == NULL)
2133 		return EAGAIN;
2134 
2135 	get_mplock();
2136 
2137 	for (;;) {
2138 		if ((cb = TAILQ_FIRST(&ki->kaio_jobdone)) != 0) {
2139 			suword(uap->aiocbp, (uintptr_t)cb->uuaiocb);
2140 			uap->sysmsg_result = cb->uaiocb._aiocb_private.status;
2141 			if (cb->uaiocb.aio_lio_opcode == LIO_WRITE) {
2142 				lp->lwp_ru.ru_oublock +=
2143 				    cb->outputcharge;
2144 				cb->outputcharge = 0;
2145 			} else if (cb->uaiocb.aio_lio_opcode == LIO_READ) {
2146 				lp->lwp_ru.ru_inblock += cb->inputcharge;
2147 				cb->inputcharge = 0;
2148 			}
2149 			aio_free_entry(cb);
2150 			error = cb->uaiocb._aiocb_private.error;
2151 			break;
2152 		}
2153 
2154 		crit_enter();
2155  		if ((cb = TAILQ_FIRST(&ki->kaio_bufdone)) != 0 ) {
2156 			crit_exit();
2157 			suword(uap->aiocbp, (uintptr_t)cb->uuaiocb);
2158 			uap->sysmsg_result = cb->uaiocb._aiocb_private.status;
2159 			aio_free_entry(cb);
2160 			error = cb->uaiocb._aiocb_private.error;
2161 			break;
2162 		}
2163 
2164 		ki->kaio_flags |= KAIO_WAKEUP;
2165 		error = tsleep(p, PCATCH, "aiowc", timo);
2166 		crit_exit();
2167 
2168 		if (error == ERESTART) {
2169 			error = EINTR;
2170 			break;
2171 		}
2172 		if (error < 0)
2173 			break;
2174 		if (error == EINTR)
2175 			break;
2176 		if (error == EWOULDBLOCK) {
2177 			error = EAGAIN;
2178 			break;
2179 		}
2180 	}
2181 	rel_mplock();
2182 	return (error);
2183 #endif /* VFS_AIO */
2184 }
2185 
2186 #ifndef VFS_AIO
2187 static int
2188 filt_aioattach(struct knote *kn)
2189 {
2190 
2191 	return (ENXIO);
2192 }
2193 
2194 struct filterops aio_filtops =
2195 	{ 0, filt_aioattach, NULL, NULL };
2196 
2197 #else
2198 /* kqueue attach function */
2199 static int
2200 filt_aioattach(struct knote *kn)
2201 {
2202 	struct aiocblist *aiocbe = (struct aiocblist *)kn->kn_sdata;
2203 
2204 	/*
2205 	 * The aiocbe pointer must be validated before using it, so
2206 	 * registration is restricted to the kernel; the user cannot
2207 	 * set EV_FLAG1.
2208 	 */
2209 	if ((kn->kn_flags & EV_FLAG1) == 0)
2210 		return (EPERM);
2211 	kn->kn_flags &= ~EV_FLAG1;
2212 
2213 	knote_insert(&aiocbe->klist, kn);
2214 
2215 	return (0);
2216 }
2217 
2218 /* kqueue detach function */
2219 static void
2220 filt_aiodetach(struct knote *kn)
2221 {
2222 	struct aiocblist *aiocbe = (struct aiocblist *)kn->kn_sdata;
2223 
2224 	knote_remove(&aiocbe->klist, kn);
2225 }
2226 
2227 /* kqueue filter function */
2228 /*ARGSUSED*/
2229 static int
2230 filt_aio(struct knote *kn, long hint)
2231 {
2232 	struct aiocblist *aiocbe = (struct aiocblist *)kn->kn_sdata;
2233 
2234 	kn->kn_data = aiocbe->uaiocb._aiocb_private.error;
2235 	if (aiocbe->jobstate != JOBST_JOBFINISHED &&
2236 	    aiocbe->jobstate != JOBST_JOBBFINISHED)
2237 		return (0);
2238 	kn->kn_flags |= EV_EOF;
2239 	return (1);
2240 }
2241 
2242 struct filterops aio_filtops =
2243 	{ 0, filt_aioattach, filt_aiodetach, filt_aio };
2244 #endif /* VFS_AIO */
2245