xref: /dragonfly/sys/kern/vfs_aio.c (revision 984263bc)
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  */
18 
19 /*
20  * This file contains support for the POSIX 1003.1B AIO/LIO facility.
21  */
22 
23 #include <sys/param.h>
24 #include <sys/systm.h>
25 #include <sys/buf.h>
26 #include <sys/sysproto.h>
27 #include <sys/filedesc.h>
28 #include <sys/kernel.h>
29 #include <sys/fcntl.h>
30 #include <sys/file.h>
31 #include <sys/lock.h>
32 #include <sys/unistd.h>
33 #include <sys/proc.h>
34 #include <sys/resourcevar.h>
35 #include <sys/signalvar.h>
36 #include <sys/protosw.h>
37 #include <sys/socketvar.h>
38 #include <sys/sysctl.h>
39 #include <sys/vnode.h>
40 #include <sys/conf.h>
41 #include <sys/event.h>
42 
43 #include <vm/vm.h>
44 #include <vm/vm_extern.h>
45 #include <vm/pmap.h>
46 #include <vm/vm_map.h>
47 #include <vm/vm_zone.h>
48 #include <sys/aio.h>
49 
50 #include <machine/limits.h>
51 #include "opt_vfs_aio.h"
52 
53 #ifdef VFS_AIO
54 
55 /*
56  * Counter for allocating reference ids to new jobs.  Wrapped to 1 on
57  * overflow.
58  */
59 static	long jobrefid;
60 
61 #define JOBST_NULL		0x0
62 #define JOBST_JOBQGLOBAL	0x2
63 #define JOBST_JOBRUNNING	0x3
64 #define JOBST_JOBFINISHED	0x4
65 #define	JOBST_JOBQBUF		0x5
66 #define	JOBST_JOBBFINISHED	0x6
67 
68 #ifndef MAX_AIO_PER_PROC
69 #define MAX_AIO_PER_PROC	32
70 #endif
71 
72 #ifndef MAX_AIO_QUEUE_PER_PROC
73 #define MAX_AIO_QUEUE_PER_PROC	256 /* Bigger than AIO_LISTIO_MAX */
74 #endif
75 
76 #ifndef MAX_AIO_PROCS
77 #define MAX_AIO_PROCS		32
78 #endif
79 
80 #ifndef MAX_AIO_QUEUE
81 #define	MAX_AIO_QUEUE		1024 /* Bigger than AIO_LISTIO_MAX */
82 #endif
83 
84 #ifndef TARGET_AIO_PROCS
85 #define TARGET_AIO_PROCS	4
86 #endif
87 
88 #ifndef MAX_BUF_AIO
89 #define MAX_BUF_AIO		16
90 #endif
91 
92 #ifndef AIOD_TIMEOUT_DEFAULT
93 #define	AIOD_TIMEOUT_DEFAULT	(10 * hz)
94 #endif
95 
96 #ifndef AIOD_LIFETIME_DEFAULT
97 #define AIOD_LIFETIME_DEFAULT	(30 * hz)
98 #endif
99 
100 SYSCTL_NODE(_vfs, OID_AUTO, aio, CTLFLAG_RW, 0, "Async IO management");
101 
102 static int max_aio_procs = MAX_AIO_PROCS;
103 SYSCTL_INT(_vfs_aio, OID_AUTO, max_aio_procs,
104 	CTLFLAG_RW, &max_aio_procs, 0,
105 	"Maximum number of kernel threads to use for handling async IO");
106 
107 static int num_aio_procs = 0;
108 SYSCTL_INT(_vfs_aio, OID_AUTO, num_aio_procs,
109 	CTLFLAG_RD, &num_aio_procs, 0,
110 	"Number of presently active kernel threads for async IO");
111 
112 /*
113  * The code will adjust the actual number of AIO processes towards this
114  * number when it gets a chance.
115  */
116 static int target_aio_procs = TARGET_AIO_PROCS;
117 SYSCTL_INT(_vfs_aio, OID_AUTO, target_aio_procs, CTLFLAG_RW, &target_aio_procs,
118 	0, "Preferred number of ready kernel threads for async IO");
119 
120 static int max_queue_count = MAX_AIO_QUEUE;
121 SYSCTL_INT(_vfs_aio, OID_AUTO, max_aio_queue, CTLFLAG_RW, &max_queue_count, 0,
122     "Maximum number of aio requests to queue, globally");
123 
124 static int num_queue_count = 0;
125 SYSCTL_INT(_vfs_aio, OID_AUTO, num_queue_count, CTLFLAG_RD, &num_queue_count, 0,
126     "Number of queued aio requests");
127 
128 static int num_buf_aio = 0;
129 SYSCTL_INT(_vfs_aio, OID_AUTO, num_buf_aio, CTLFLAG_RD, &num_buf_aio, 0,
130     "Number of aio requests presently handled by the buf subsystem");
131 
132 /* Number of async I/O thread in the process of being started */
133 /* XXX This should be local to _aio_aqueue() */
134 static int num_aio_resv_start = 0;
135 
136 static int aiod_timeout;
137 SYSCTL_INT(_vfs_aio, OID_AUTO, aiod_timeout, CTLFLAG_RW, &aiod_timeout, 0,
138     "Timeout value for synchronous aio operations");
139 
140 static int aiod_lifetime;
141 SYSCTL_INT(_vfs_aio, OID_AUTO, aiod_lifetime, CTLFLAG_RW, &aiod_lifetime, 0,
142     "Maximum lifetime for idle aiod");
143 
144 static int max_aio_per_proc = MAX_AIO_PER_PROC;
145 SYSCTL_INT(_vfs_aio, OID_AUTO, max_aio_per_proc, CTLFLAG_RW, &max_aio_per_proc,
146     0, "Maximum active aio requests per process (stored in the process)");
147 
148 static int max_aio_queue_per_proc = MAX_AIO_QUEUE_PER_PROC;
149 SYSCTL_INT(_vfs_aio, OID_AUTO, max_aio_queue_per_proc, CTLFLAG_RW,
150     &max_aio_queue_per_proc, 0,
151     "Maximum queued aio requests per process (stored in the process)");
152 
153 static int max_buf_aio = MAX_BUF_AIO;
154 SYSCTL_INT(_vfs_aio, OID_AUTO, max_buf_aio, CTLFLAG_RW, &max_buf_aio, 0,
155     "Maximum buf aio requests per process (stored in the process)");
156 
157 /*
158  * AIO process info
159  */
160 #define AIOP_FREE	0x1			/* proc on free queue */
161 #define AIOP_SCHED	0x2			/* proc explicitly scheduled */
162 
163 struct aioproclist {
164 	int aioprocflags;			/* AIO proc flags */
165 	TAILQ_ENTRY(aioproclist) list;		/* List of processes */
166 	struct proc *aioproc;			/* The AIO thread */
167 };
168 
169 /*
170  * data-structure for lio signal management
171  */
172 struct aio_liojob {
173 	int	lioj_flags;
174 	int	lioj_buffer_count;
175 	int	lioj_buffer_finished_count;
176 	int	lioj_queue_count;
177 	int	lioj_queue_finished_count;
178 	struct	sigevent lioj_signal;	/* signal on all I/O done */
179 	TAILQ_ENTRY(aio_liojob) lioj_list;
180 	struct	kaioinfo *lioj_ki;
181 };
182 #define	LIOJ_SIGNAL		0x1	/* signal on all done (lio) */
183 #define	LIOJ_SIGNAL_POSTED	0x2	/* signal has been posted */
184 
185 /*
186  * per process aio data structure
187  */
188 struct kaioinfo {
189 	int	kaio_flags;		/* per process kaio flags */
190 	int	kaio_maxactive_count;	/* maximum number of AIOs */
191 	int	kaio_active_count;	/* number of currently used AIOs */
192 	int	kaio_qallowed_count;	/* maxiumu size of AIO queue */
193 	int	kaio_queue_count;	/* size of AIO queue */
194 	int	kaio_ballowed_count;	/* maximum number of buffers */
195 	int	kaio_queue_finished_count; /* number of daemon jobs finished */
196 	int	kaio_buffer_count;	/* number of physio buffers */
197 	int	kaio_buffer_finished_count; /* count of I/O done */
198 	struct 	proc *kaio_p;		/* process that uses this kaio block */
199 	TAILQ_HEAD(,aio_liojob) kaio_liojoblist; /* list of lio jobs */
200 	TAILQ_HEAD(,aiocblist) kaio_jobqueue;	/* job queue for process */
201 	TAILQ_HEAD(,aiocblist) kaio_jobdone;	/* done queue for process */
202 	TAILQ_HEAD(,aiocblist) kaio_bufqueue;	/* buffer job queue for process */
203 	TAILQ_HEAD(,aiocblist) kaio_bufdone;	/* buffer done queue for process */
204 	TAILQ_HEAD(,aiocblist) kaio_sockqueue;	/* queue for aios waiting on sockets */
205 };
206 
207 #define KAIO_RUNDOWN	0x1	/* process is being run down */
208 #define KAIO_WAKEUP	0x2	/* wakeup process when there is a significant event */
209 
210 static TAILQ_HEAD(,aioproclist) aio_freeproc, aio_activeproc;
211 static TAILQ_HEAD(,aiocblist) aio_jobs;			/* Async job list */
212 static TAILQ_HEAD(,aiocblist) aio_bufjobs;		/* Phys I/O job list */
213 static TAILQ_HEAD(,aiocblist) aio_freejobs;		/* Pool of free jobs */
214 
215 static void	aio_init_aioinfo(struct proc *p);
216 static void	aio_onceonly(void *);
217 static int	aio_free_entry(struct aiocblist *aiocbe);
218 static void	aio_process(struct aiocblist *aiocbe);
219 static int	aio_newproc(void);
220 static int	aio_aqueue(struct proc *p, struct aiocb *job, int type);
221 static void	aio_physwakeup(struct buf *bp);
222 static int	aio_fphysio(struct aiocblist *aiocbe);
223 static int	aio_qphysio(struct proc *p, struct aiocblist *iocb);
224 static void	aio_daemon(void *uproc);
225 static void	process_signal(void *aioj);
226 
227 SYSINIT(aio, SI_SUB_VFS, SI_ORDER_ANY, aio_onceonly, NULL);
228 
229 /*
230  * Zones for:
231  * 	kaio	Per process async io info
232  *	aiop	async io thread data
233  *	aiocb	async io jobs
234  *	aiol	list io job pointer - internal to aio_suspend XXX
235  *	aiolio	list io jobs
236  */
237 static vm_zone_t kaio_zone, aiop_zone, aiocb_zone, aiol_zone, aiolio_zone;
238 
239 /*
240  * Startup initialization
241  */
242 static void
243 aio_onceonly(void *na)
244 {
245 	TAILQ_INIT(&aio_freeproc);
246 	TAILQ_INIT(&aio_activeproc);
247 	TAILQ_INIT(&aio_jobs);
248 	TAILQ_INIT(&aio_bufjobs);
249 	TAILQ_INIT(&aio_freejobs);
250 	kaio_zone = zinit("AIO", sizeof(struct kaioinfo), 0, 0, 1);
251 	aiop_zone = zinit("AIOP", sizeof(struct aioproclist), 0, 0, 1);
252 	aiocb_zone = zinit("AIOCB", sizeof(struct aiocblist), 0, 0, 1);
253 	aiol_zone = zinit("AIOL", AIO_LISTIO_MAX*sizeof(intptr_t), 0, 0, 1);
254 	aiolio_zone = zinit("AIOLIO", sizeof(struct aio_liojob), 0, 0, 1);
255 	aiod_timeout = AIOD_TIMEOUT_DEFAULT;
256 	aiod_lifetime = AIOD_LIFETIME_DEFAULT;
257 	jobrefid = 1;
258 }
259 
260 /*
261  * Init the per-process aioinfo structure.  The aioinfo limits are set
262  * per-process for user limit (resource) management.
263  */
264 static void
265 aio_init_aioinfo(struct proc *p)
266 {
267 	struct kaioinfo *ki;
268 	if (p->p_aioinfo == NULL) {
269 		ki = zalloc(kaio_zone);
270 		p->p_aioinfo = ki;
271 		ki->kaio_flags = 0;
272 		ki->kaio_maxactive_count = max_aio_per_proc;
273 		ki->kaio_active_count = 0;
274 		ki->kaio_qallowed_count = max_aio_queue_per_proc;
275 		ki->kaio_queue_count = 0;
276 		ki->kaio_ballowed_count = max_buf_aio;
277 		ki->kaio_buffer_count = 0;
278 		ki->kaio_buffer_finished_count = 0;
279 		ki->kaio_p = p;
280 		TAILQ_INIT(&ki->kaio_jobdone);
281 		TAILQ_INIT(&ki->kaio_jobqueue);
282 		TAILQ_INIT(&ki->kaio_bufdone);
283 		TAILQ_INIT(&ki->kaio_bufqueue);
284 		TAILQ_INIT(&ki->kaio_liojoblist);
285 		TAILQ_INIT(&ki->kaio_sockqueue);
286 	}
287 
288 	while (num_aio_procs < target_aio_procs)
289 		aio_newproc();
290 }
291 
292 /*
293  * Free a job entry.  Wait for completion if it is currently active, but don't
294  * delay forever.  If we delay, we return a flag that says that we have to
295  * restart the queue scan.
296  */
297 static int
298 aio_free_entry(struct aiocblist *aiocbe)
299 {
300 	struct kaioinfo *ki;
301 	struct aio_liojob *lj;
302 	struct proc *p;
303 	int error;
304 	int s;
305 
306 	if (aiocbe->jobstate == JOBST_NULL)
307 		panic("aio_free_entry: freeing already free job");
308 
309 	p = aiocbe->userproc;
310 	ki = p->p_aioinfo;
311 	lj = aiocbe->lio;
312 	if (ki == NULL)
313 		panic("aio_free_entry: missing p->p_aioinfo");
314 
315 	while (aiocbe->jobstate == JOBST_JOBRUNNING) {
316 		aiocbe->jobflags |= AIOCBLIST_RUNDOWN;
317 		tsleep(aiocbe, PRIBIO, "jobwai", 0);
318 	}
319 	if (aiocbe->bp == NULL) {
320 		if (ki->kaio_queue_count <= 0)
321 			panic("aio_free_entry: process queue size <= 0");
322 		if (num_queue_count <= 0)
323 			panic("aio_free_entry: system wide queue size <= 0");
324 
325 		if (lj) {
326 			lj->lioj_queue_count--;
327 			if (aiocbe->jobflags & AIOCBLIST_DONE)
328 				lj->lioj_queue_finished_count--;
329 		}
330 		ki->kaio_queue_count--;
331 		if (aiocbe->jobflags & AIOCBLIST_DONE)
332 			ki->kaio_queue_finished_count--;
333 		num_queue_count--;
334 	} else {
335 		if (lj) {
336 			lj->lioj_buffer_count--;
337 			if (aiocbe->jobflags & AIOCBLIST_DONE)
338 				lj->lioj_buffer_finished_count--;
339 		}
340 		if (aiocbe->jobflags & AIOCBLIST_DONE)
341 			ki->kaio_buffer_finished_count--;
342 		ki->kaio_buffer_count--;
343 		num_buf_aio--;
344 	}
345 
346 	/* aiocbe is going away, we need to destroy any knotes */
347 	knote_remove(p, &aiocbe->klist);
348 
349 	if ((ki->kaio_flags & KAIO_WAKEUP) || ((ki->kaio_flags & KAIO_RUNDOWN)
350 	    && ((ki->kaio_buffer_count == 0) && (ki->kaio_queue_count == 0)))) {
351 		ki->kaio_flags &= ~KAIO_WAKEUP;
352 		wakeup(p);
353 	}
354 
355 	if (aiocbe->jobstate == JOBST_JOBQBUF) {
356 		if ((error = aio_fphysio(aiocbe)) != 0)
357 			return error;
358 		if (aiocbe->jobstate != JOBST_JOBBFINISHED)
359 			panic("aio_free_entry: invalid physio finish-up state");
360 		s = splbio();
361 		TAILQ_REMOVE(&ki->kaio_bufdone, aiocbe, plist);
362 		splx(s);
363 	} else if (aiocbe->jobstate == JOBST_JOBQGLOBAL) {
364 		s = splnet();
365 		TAILQ_REMOVE(&aio_jobs, aiocbe, list);
366 		TAILQ_REMOVE(&ki->kaio_jobqueue, aiocbe, plist);
367 		splx(s);
368 	} else if (aiocbe->jobstate == JOBST_JOBFINISHED)
369 		TAILQ_REMOVE(&ki->kaio_jobdone, aiocbe, plist);
370 	else if (aiocbe->jobstate == JOBST_JOBBFINISHED) {
371 		s = splbio();
372 		TAILQ_REMOVE(&ki->kaio_bufdone, aiocbe, plist);
373 		splx(s);
374 		if (aiocbe->bp) {
375 			vunmapbuf(aiocbe->bp);
376 			relpbuf(aiocbe->bp, NULL);
377 			aiocbe->bp = NULL;
378 		}
379 	}
380 	if (lj && (lj->lioj_buffer_count == 0) && (lj->lioj_queue_count == 0)) {
381 		TAILQ_REMOVE(&ki->kaio_liojoblist, lj, lioj_list);
382 		zfree(aiolio_zone, lj);
383 	}
384 	aiocbe->jobstate = JOBST_NULL;
385 	untimeout(process_signal, aiocbe, aiocbe->timeouthandle);
386 	fdrop(aiocbe->fd_file, curproc);
387 	TAILQ_INSERT_HEAD(&aio_freejobs, aiocbe, list);
388 	return 0;
389 }
390 #endif /* VFS_AIO */
391 
392 /*
393  * Rundown the jobs for a given process.
394  */
395 void
396 aio_proc_rundown(struct proc *p)
397 {
398 #ifndef VFS_AIO
399 	return;
400 #else
401 	int s;
402 	struct kaioinfo *ki;
403 	struct aio_liojob *lj, *ljn;
404 	struct aiocblist *aiocbe, *aiocbn;
405 	struct file *fp;
406 	struct socket *so;
407 
408 	ki = p->p_aioinfo;
409 	if (ki == NULL)
410 		return;
411 
412 	ki->kaio_flags |= LIOJ_SIGNAL_POSTED;
413 	while ((ki->kaio_active_count > 0) || (ki->kaio_buffer_count >
414 	    ki->kaio_buffer_finished_count)) {
415 		ki->kaio_flags |= KAIO_RUNDOWN;
416 		if (tsleep(p, PRIBIO, "kaiowt", aiod_timeout))
417 			break;
418 	}
419 
420 	/*
421 	 * Move any aio ops that are waiting on socket I/O to the normal job
422 	 * queues so they are cleaned up with any others.
423 	 */
424 	s = splnet();
425 	for (aiocbe = TAILQ_FIRST(&ki->kaio_sockqueue); aiocbe; aiocbe =
426 	    aiocbn) {
427 		aiocbn = TAILQ_NEXT(aiocbe, plist);
428 		fp = aiocbe->fd_file;
429 		if (fp != NULL) {
430 			so = (struct socket *)fp->f_data;
431 			TAILQ_REMOVE(&so->so_aiojobq, aiocbe, list);
432 			if (TAILQ_EMPTY(&so->so_aiojobq)) {
433 				so->so_snd.sb_flags &= ~SB_AIO;
434 				so->so_rcv.sb_flags &= ~SB_AIO;
435 			}
436 		}
437 		TAILQ_REMOVE(&ki->kaio_sockqueue, aiocbe, plist);
438 		TAILQ_INSERT_HEAD(&aio_jobs, aiocbe, list);
439 		TAILQ_INSERT_HEAD(&ki->kaio_jobqueue, aiocbe, plist);
440 	}
441 	splx(s);
442 
443 restart1:
444 	for (aiocbe = TAILQ_FIRST(&ki->kaio_jobdone); aiocbe; aiocbe = aiocbn) {
445 		aiocbn = TAILQ_NEXT(aiocbe, plist);
446 		if (aio_free_entry(aiocbe))
447 			goto restart1;
448 	}
449 
450 restart2:
451 	for (aiocbe = TAILQ_FIRST(&ki->kaio_jobqueue); aiocbe; aiocbe =
452 	    aiocbn) {
453 		aiocbn = TAILQ_NEXT(aiocbe, plist);
454 		if (aio_free_entry(aiocbe))
455 			goto restart2;
456 	}
457 
458 /*
459  * Note the use of lots of splbio here, trying to avoid splbio for long chains
460  * of I/O.  Probably unnecessary.
461  */
462 restart3:
463 	s = splbio();
464 	while (TAILQ_FIRST(&ki->kaio_bufqueue)) {
465 		ki->kaio_flags |= KAIO_WAKEUP;
466 		tsleep(p, PRIBIO, "aioprn", 0);
467 		splx(s);
468 		goto restart3;
469 	}
470 	splx(s);
471 
472 restart4:
473 	s = splbio();
474 	for (aiocbe = TAILQ_FIRST(&ki->kaio_bufdone); aiocbe; aiocbe = aiocbn) {
475 		aiocbn = TAILQ_NEXT(aiocbe, plist);
476 		if (aio_free_entry(aiocbe)) {
477 			splx(s);
478 			goto restart4;
479 		}
480 	}
481 	splx(s);
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 			printf("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 	int s;
523 	struct aiocblist *aiocbe;
524 	struct kaioinfo *ki;
525 	struct proc *userp;
526 
527 	s = splnet();
528 	for (aiocbe = TAILQ_FIRST(&aio_jobs); aiocbe; aiocbe =
529 	    TAILQ_NEXT(aiocbe, list)) {
530 		userp = aiocbe->userproc;
531 		ki = userp->p_aioinfo;
532 
533 		if (ki->kaio_active_count < ki->kaio_maxactive_count) {
534 			TAILQ_REMOVE(&aio_jobs, aiocbe, list);
535 			splx(s);
536 			return aiocbe;
537 		}
538 	}
539 	splx(s);
540 
541 	return NULL;
542 }
543 
544 /*
545  * The AIO processing activity.  This is the code that does the I/O request for
546  * the non-physio version of the operations.  The normal vn operations are used,
547  * and this code should work in all instances for every type of file, including
548  * pipes, sockets, fifos, and regular files.
549  */
550 static void
551 aio_process(struct aiocblist *aiocbe)
552 {
553 	struct proc *mycp;
554 	struct aiocb *cb;
555 	struct file *fp;
556 	struct uio auio;
557 	struct iovec aiov;
558 	int cnt;
559 	int error;
560 	int oublock_st, oublock_end;
561 	int inblock_st, inblock_end;
562 
563 	mycp = curproc;
564 	cb = &aiocbe->uaiocb;
565 	fp = aiocbe->fd_file;
566 
567 	aiov.iov_base = (void *)(uintptr_t)cb->aio_buf;
568 	aiov.iov_len = cb->aio_nbytes;
569 
570 	auio.uio_iov = &aiov;
571 	auio.uio_iovcnt = 1;
572 	auio.uio_offset = cb->aio_offset;
573 	auio.uio_resid = cb->aio_nbytes;
574 	cnt = cb->aio_nbytes;
575 	auio.uio_segflg = UIO_USERSPACE;
576 	auio.uio_procp = mycp;
577 
578 	inblock_st = mycp->p_stats->p_ru.ru_inblock;
579 	oublock_st = mycp->p_stats->p_ru.ru_oublock;
580 	/*
581 	 * _aio_aqueue() acquires a reference to the file that is
582 	 * released in aio_free_entry().
583 	 */
584 	if (cb->aio_lio_opcode == LIO_READ) {
585 		auio.uio_rw = UIO_READ;
586 		error = fo_read(fp, &auio, fp->f_cred, FOF_OFFSET, mycp);
587 	} else {
588 		auio.uio_rw = UIO_WRITE;
589 		error = fo_write(fp, &auio, fp->f_cred, FOF_OFFSET, mycp);
590 	}
591 	inblock_end = mycp->p_stats->p_ru.ru_inblock;
592 	oublock_end = mycp->p_stats->p_ru.ru_oublock;
593 
594 	aiocbe->inputcharge = inblock_end - inblock_st;
595 	aiocbe->outputcharge = oublock_end - oublock_st;
596 
597 	if ((error) && (auio.uio_resid != cnt)) {
598 		if (error == ERESTART || error == EINTR || error == EWOULDBLOCK)
599 			error = 0;
600 		if ((error == EPIPE) && (cb->aio_lio_opcode == LIO_WRITE))
601 			psignal(aiocbe->userproc, SIGPIPE);
602 	}
603 
604 	cnt -= auio.uio_resid;
605 	cb->_aiocb_private.error = error;
606 	cb->_aiocb_private.status = cnt;
607 }
608 
609 /*
610  * The AIO daemon, most of the actual work is done in aio_process,
611  * but the setup (and address space mgmt) is done in this routine.
612  */
613 static void
614 aio_daemon(void *uproc)
615 {
616 	int s;
617 	struct aio_liojob *lj;
618 	struct aiocb *cb;
619 	struct aiocblist *aiocbe;
620 	struct aioproclist *aiop;
621 	struct kaioinfo *ki;
622 	struct proc *curcp, *mycp, *userp;
623 	struct vmspace *myvm, *tmpvm;
624 
625 	/*
626 	 * Local copies of curproc (cp) and vmspace (myvm)
627 	 */
628 	mycp = curproc;
629 	myvm = mycp->p_vmspace;
630 
631 	if (mycp->p_textvp) {
632 		vrele(mycp->p_textvp);
633 		mycp->p_textvp = NULL;
634 	}
635 
636 	/*
637 	 * Allocate and ready the aio control info.  There is one aiop structure
638 	 * per daemon.
639 	 */
640 	aiop = zalloc(aiop_zone);
641 	aiop->aioproc = mycp;
642 	aiop->aioprocflags |= AIOP_FREE;
643 
644 	s = splnet();
645 
646 	/*
647 	 * Place thread (lightweight process) onto the AIO free thread list.
648 	 */
649 	if (TAILQ_EMPTY(&aio_freeproc))
650 		wakeup(&aio_freeproc);
651 	TAILQ_INSERT_HEAD(&aio_freeproc, aiop, list);
652 
653 	splx(s);
654 
655 	/* Make up a name for the daemon. */
656 	strcpy(mycp->p_comm, "aiod");
657 
658 	/*
659 	 * Get rid of our current filedescriptors.  AIOD's don't need any
660 	 * filedescriptors, except as temporarily inherited from the client.
661 	 * Credentials are also cloned, and made equivalent to "root".
662 	 */
663 	fdfree(mycp);
664 	mycp->p_fd = NULL;
665 	mycp->p_ucred = crcopy(mycp->p_ucred);
666 	mycp->p_ucred->cr_uid = 0;
667 	uifree(mycp->p_ucred->cr_uidinfo);
668 	mycp->p_ucred->cr_uidinfo = uifind(0);
669 	mycp->p_ucred->cr_ngroups = 1;
670 	mycp->p_ucred->cr_groups[0] = 1;
671 
672 	/* The daemon resides in its own pgrp. */
673 	enterpgrp(mycp, mycp->p_pid, 1);
674 
675 	/* Mark special process type. */
676 	mycp->p_flag |= P_SYSTEM | P_KTHREADP;
677 
678 	/*
679 	 * Wakeup parent process.  (Parent sleeps to keep from blasting away
680 	 * and creating too many daemons.)
681 	 */
682 	wakeup(mycp);
683 
684 	for (;;) {
685 		/*
686 		 * curcp is the current daemon process context.
687 		 * userp is the current user process context.
688 		 */
689 		curcp = mycp;
690 
691 		/*
692 		 * Take daemon off of free queue
693 		 */
694 		if (aiop->aioprocflags & AIOP_FREE) {
695 			s = splnet();
696 			TAILQ_REMOVE(&aio_freeproc, aiop, list);
697 			TAILQ_INSERT_TAIL(&aio_activeproc, aiop, list);
698 			aiop->aioprocflags &= ~AIOP_FREE;
699 			splx(s);
700 		}
701 		aiop->aioprocflags &= ~AIOP_SCHED;
702 
703 		/*
704 		 * Check for jobs.
705 		 */
706 		while ((aiocbe = aio_selectjob(aiop)) != NULL) {
707 			cb = &aiocbe->uaiocb;
708 			userp = aiocbe->userproc;
709 
710 			aiocbe->jobstate = JOBST_JOBRUNNING;
711 
712 			/*
713 			 * Connect to process address space for user program.
714 			 */
715 			if (userp != curcp) {
716 				/*
717 				 * Save the current address space that we are
718 				 * connected to.
719 				 */
720 				tmpvm = mycp->p_vmspace;
721 
722 				/*
723 				 * Point to the new user address space, and
724 				 * refer to it.
725 				 */
726 				mycp->p_vmspace = userp->p_vmspace;
727 				mycp->p_vmspace->vm_refcnt++;
728 
729 				/* Activate the new mapping. */
730 				pmap_activate(mycp);
731 
732 				/*
733 				 * If the old address space wasn't the daemons
734 				 * own address space, then we need to remove the
735 				 * daemon's reference from the other process
736 				 * that it was acting on behalf of.
737 				 */
738 				if (tmpvm != myvm) {
739 					vmspace_free(tmpvm);
740 				}
741 				curcp = userp;
742 			}
743 
744 			ki = userp->p_aioinfo;
745 			lj = aiocbe->lio;
746 
747 			/* Account for currently active jobs. */
748 			ki->kaio_active_count++;
749 
750 			/* Do the I/O function. */
751 			aio_process(aiocbe);
752 
753 			/* Decrement the active job count. */
754 			ki->kaio_active_count--;
755 
756 			/*
757 			 * Increment the completion count for wakeup/signal
758 			 * comparisons.
759 			 */
760 			aiocbe->jobflags |= AIOCBLIST_DONE;
761 			ki->kaio_queue_finished_count++;
762 			if (lj)
763 				lj->lioj_queue_finished_count++;
764 			if ((ki->kaio_flags & KAIO_WAKEUP) || ((ki->kaio_flags
765 			    & KAIO_RUNDOWN) && (ki->kaio_active_count == 0))) {
766 				ki->kaio_flags &= ~KAIO_WAKEUP;
767 				wakeup(userp);
768 			}
769 
770 			s = splbio();
771 			if (lj && (lj->lioj_flags &
772 			    (LIOJ_SIGNAL|LIOJ_SIGNAL_POSTED)) == LIOJ_SIGNAL) {
773 				if ((lj->lioj_queue_finished_count ==
774 				    lj->lioj_queue_count) &&
775 				    (lj->lioj_buffer_finished_count ==
776 				    lj->lioj_buffer_count)) {
777 						psignal(userp,
778 						    lj->lioj_signal.sigev_signo);
779 						lj->lioj_flags |=
780 						    LIOJ_SIGNAL_POSTED;
781 				}
782 			}
783 			splx(s);
784 
785 			aiocbe->jobstate = JOBST_JOBFINISHED;
786 
787 			s = splnet();
788 			TAILQ_REMOVE(&ki->kaio_jobqueue, aiocbe, plist);
789 			TAILQ_INSERT_TAIL(&ki->kaio_jobdone, aiocbe, plist);
790 			splx(s);
791 			KNOTE(&aiocbe->klist, 0);
792 
793 			if (aiocbe->jobflags & AIOCBLIST_RUNDOWN) {
794 				wakeup(aiocbe);
795 				aiocbe->jobflags &= ~AIOCBLIST_RUNDOWN;
796 			}
797 
798 			if (cb->aio_sigevent.sigev_notify == SIGEV_SIGNAL) {
799 				psignal(userp, cb->aio_sigevent.sigev_signo);
800 			}
801 		}
802 
803 		/*
804 		 * Disconnect from user address space.
805 		 */
806 		if (curcp != mycp) {
807 			/* Get the user address space to disconnect from. */
808 			tmpvm = mycp->p_vmspace;
809 
810 			/* Get original address space for daemon. */
811 			mycp->p_vmspace = myvm;
812 
813 			/* Activate the daemon's address space. */
814 			pmap_activate(mycp);
815 #ifdef DIAGNOSTIC
816 			if (tmpvm == myvm) {
817 				printf("AIOD: vmspace problem -- %d\n",
818 				    mycp->p_pid);
819 			}
820 #endif
821 			/* Remove our vmspace reference. */
822 			vmspace_free(tmpvm);
823 
824 			curcp = mycp;
825 		}
826 
827 		/*
828 		 * If we are the first to be put onto the free queue, wakeup
829 		 * anyone waiting for a daemon.
830 		 */
831 		s = splnet();
832 		TAILQ_REMOVE(&aio_activeproc, aiop, list);
833 		if (TAILQ_EMPTY(&aio_freeproc))
834 			wakeup(&aio_freeproc);
835 		TAILQ_INSERT_HEAD(&aio_freeproc, aiop, list);
836 		aiop->aioprocflags |= AIOP_FREE;
837 		splx(s);
838 
839 		/*
840 		 * If daemon is inactive for a long time, allow it to exit,
841 		 * thereby freeing resources.
842 		 */
843 		if (((aiop->aioprocflags & AIOP_SCHED) == 0) && tsleep(mycp,
844 		    PRIBIO, "aiordy", aiod_lifetime)) {
845 			s = splnet();
846 			if (TAILQ_EMPTY(&aio_jobs)) {
847 				if ((aiop->aioprocflags & AIOP_FREE) &&
848 				    (num_aio_procs > target_aio_procs)) {
849 					TAILQ_REMOVE(&aio_freeproc, aiop, list);
850 					splx(s);
851 					zfree(aiop_zone, aiop);
852 					num_aio_procs--;
853 #ifdef DIAGNOSTIC
854 					if (mycp->p_vmspace->vm_refcnt <= 1) {
855 						printf("AIOD: bad vm refcnt for"
856 						    " exiting daemon: %d\n",
857 						    mycp->p_vmspace->vm_refcnt);
858 					}
859 #endif
860 					exit1(mycp, 0);
861 				}
862 			}
863 			splx(s);
864 		}
865 	}
866 }
867 
868 /*
869  * Create a new AIO daemon.  This is mostly a kernel-thread fork routine.  The
870  * AIO daemon modifies its environment itself.
871  */
872 static int
873 aio_newproc()
874 {
875 	int error;
876 	struct proc *p, *np;
877 
878 	p = &proc0;
879 	error = fork1(p, RFPROC|RFMEM|RFNOWAIT, &np);
880 	if (error)
881 		return error;
882 	cpu_set_fork_handler(np, aio_daemon, curproc);
883 
884 	/*
885 	 * Wait until daemon is started, but continue on just in case to
886 	 * handle error conditions.
887 	 */
888 	error = tsleep(np, PZERO, "aiosta", aiod_timeout);
889 	num_aio_procs++;
890 
891 	return error;
892 }
893 
894 /*
895  * Try the high-performance, low-overhead physio method for eligible
896  * VCHR devices.  This method doesn't use an aio helper thread, and
897  * thus has very low overhead.
898  *
899  * Assumes that the caller, _aio_aqueue(), has incremented the file
900  * structure's reference count, preventing its deallocation for the
901  * duration of this call.
902  */
903 static int
904 aio_qphysio(struct proc *p, struct aiocblist *aiocbe)
905 {
906 	int error;
907 	struct aiocb *cb;
908 	struct file *fp;
909 	struct buf *bp;
910 	struct vnode *vp;
911 	struct kaioinfo *ki;
912 	struct aio_liojob *lj;
913 	int s;
914 	int notify;
915 
916 	cb = &aiocbe->uaiocb;
917 	fp = aiocbe->fd_file;
918 
919 	if (fp->f_type != DTYPE_VNODE)
920 		return (-1);
921 
922 	vp = (struct vnode *)fp->f_data;
923 
924 	/*
925 	 * If its not a disk, we don't want to return a positive error.
926 	 * It causes the aio code to not fall through to try the thread
927 	 * way when you're talking to a regular file.
928 	 */
929 	if (!vn_isdisk(vp, &error)) {
930 		if (error == ENOTBLK)
931 			return (-1);
932 		else
933 			return (error);
934 	}
935 
936  	if (cb->aio_nbytes % vp->v_rdev->si_bsize_phys)
937 		return (-1);
938 
939 	if (cb->aio_nbytes >
940 	    MAXPHYS - (((vm_offset_t) cb->aio_buf) & PAGE_MASK))
941 		return (-1);
942 
943 	ki = p->p_aioinfo;
944 	if (ki->kaio_buffer_count >= ki->kaio_ballowed_count)
945 		return (-1);
946 
947 	ki->kaio_buffer_count++;
948 
949 	lj = aiocbe->lio;
950 	if (lj)
951 		lj->lioj_buffer_count++;
952 
953 	/* Create and build a buffer header for a transfer. */
954 	bp = (struct buf *)getpbuf(NULL);
955 	BUF_KERNPROC(bp);
956 
957 	/*
958 	 * Get a copy of the kva from the physical buffer.
959 	 */
960 	bp->b_caller1 = p;
961 	bp->b_dev = vp->v_rdev;
962 	error = 0;
963 
964 	bp->b_bcount = cb->aio_nbytes;
965 	bp->b_bufsize = cb->aio_nbytes;
966 	bp->b_flags = B_PHYS | B_CALL | (cb->aio_lio_opcode == LIO_WRITE ?
967 	    B_WRITE : B_READ);
968 	bp->b_iodone = aio_physwakeup;
969 	bp->b_saveaddr = bp->b_data;
970 	bp->b_data = (void *)(uintptr_t)cb->aio_buf;
971 	bp->b_blkno = btodb(cb->aio_offset);
972 
973 	/* Bring buffer into kernel space. */
974 	if (vmapbuf(bp) < 0) {
975 		error = EFAULT;
976 		goto doerror;
977 	}
978 
979 	s = splbio();
980 	aiocbe->bp = bp;
981 	bp->b_spc = (void *)aiocbe;
982 	TAILQ_INSERT_TAIL(&aio_bufjobs, aiocbe, list);
983 	TAILQ_INSERT_TAIL(&ki->kaio_bufqueue, aiocbe, plist);
984 	aiocbe->jobstate = JOBST_JOBQBUF;
985 	cb->_aiocb_private.status = cb->aio_nbytes;
986 	num_buf_aio++;
987 	bp->b_error = 0;
988 
989 	splx(s);
990 
991 	/* Perform transfer. */
992 	BUF_STRATEGY(bp, 0);
993 
994 	notify = 0;
995 	s = splbio();
996 
997 	/*
998 	 * If we had an error invoking the request, or an error in processing
999 	 * the request before we have returned, we process it as an error in
1000 	 * transfer.  Note that such an I/O error is not indicated immediately,
1001 	 * but is returned using the aio_error mechanism.  In this case,
1002 	 * aio_suspend will return immediately.
1003 	 */
1004 	if (bp->b_error || (bp->b_flags & B_ERROR)) {
1005 		struct aiocb *job = aiocbe->uuaiocb;
1006 
1007 		aiocbe->uaiocb._aiocb_private.status = 0;
1008 		suword(&job->_aiocb_private.status, 0);
1009 		aiocbe->uaiocb._aiocb_private.error = bp->b_error;
1010 		suword(&job->_aiocb_private.error, bp->b_error);
1011 
1012 		ki->kaio_buffer_finished_count++;
1013 
1014 		if (aiocbe->jobstate != JOBST_JOBBFINISHED) {
1015 			aiocbe->jobstate = JOBST_JOBBFINISHED;
1016 			aiocbe->jobflags |= AIOCBLIST_DONE;
1017 			TAILQ_REMOVE(&aio_bufjobs, aiocbe, list);
1018 			TAILQ_REMOVE(&ki->kaio_bufqueue, aiocbe, plist);
1019 			TAILQ_INSERT_TAIL(&ki->kaio_bufdone, aiocbe, plist);
1020 			notify = 1;
1021 		}
1022 	}
1023 	splx(s);
1024 	if (notify)
1025 		KNOTE(&aiocbe->klist, 0);
1026 	return 0;
1027 
1028 doerror:
1029 	ki->kaio_buffer_count--;
1030 	if (lj)
1031 		lj->lioj_buffer_count--;
1032 	aiocbe->bp = NULL;
1033 	relpbuf(bp, NULL);
1034 	return error;
1035 }
1036 
1037 /*
1038  * This waits/tests physio completion.
1039  */
1040 static int
1041 aio_fphysio(struct aiocblist *iocb)
1042 {
1043 	int s;
1044 	struct buf *bp;
1045 	int error;
1046 
1047 	bp = iocb->bp;
1048 
1049 	s = splbio();
1050 	while ((bp->b_flags & B_DONE) == 0) {
1051 		if (tsleep(bp, PRIBIO, "physstr", aiod_timeout)) {
1052 			if ((bp->b_flags & B_DONE) == 0) {
1053 				splx(s);
1054 				return EINPROGRESS;
1055 			} else
1056 				break;
1057 		}
1058 	}
1059 	splx(s);
1060 
1061 	/* Release mapping into kernel space. */
1062 	vunmapbuf(bp);
1063 	iocb->bp = 0;
1064 
1065 	error = 0;
1066 
1067 	/* Check for an error. */
1068 	if (bp->b_flags & B_ERROR)
1069 		error = bp->b_error;
1070 
1071 	relpbuf(bp, NULL);
1072 	return (error);
1073 }
1074 #endif /* VFS_AIO */
1075 
1076 /*
1077  * Wake up aio requests that may be serviceable now.
1078  */
1079 void
1080 aio_swake(struct socket *so, struct sockbuf *sb)
1081 {
1082 #ifndef VFS_AIO
1083 	return;
1084 #else
1085 	struct aiocblist *cb,*cbn;
1086 	struct proc *p;
1087 	struct kaioinfo *ki = NULL;
1088 	int opcode, wakecount = 0;
1089 	struct aioproclist *aiop;
1090 
1091 	if (sb == &so->so_snd) {
1092 		opcode = LIO_WRITE;
1093 		so->so_snd.sb_flags &= ~SB_AIO;
1094 	} else {
1095 		opcode = LIO_READ;
1096 		so->so_rcv.sb_flags &= ~SB_AIO;
1097 	}
1098 
1099 	for (cb = TAILQ_FIRST(&so->so_aiojobq); cb; cb = cbn) {
1100 		cbn = TAILQ_NEXT(cb, list);
1101 		if (opcode == cb->uaiocb.aio_lio_opcode) {
1102 			p = cb->userproc;
1103 			ki = p->p_aioinfo;
1104 			TAILQ_REMOVE(&so->so_aiojobq, cb, list);
1105 			TAILQ_REMOVE(&ki->kaio_sockqueue, cb, plist);
1106 			TAILQ_INSERT_TAIL(&aio_jobs, cb, list);
1107 			TAILQ_INSERT_TAIL(&ki->kaio_jobqueue, cb, plist);
1108 			wakecount++;
1109 			if (cb->jobstate != JOBST_JOBQGLOBAL)
1110 				panic("invalid queue value");
1111 		}
1112 	}
1113 
1114 	while (wakecount--) {
1115 		if ((aiop = TAILQ_FIRST(&aio_freeproc)) != 0) {
1116 			TAILQ_REMOVE(&aio_freeproc, aiop, list);
1117 			TAILQ_INSERT_TAIL(&aio_activeproc, aiop, list);
1118 			aiop->aioprocflags &= ~AIOP_FREE;
1119 			wakeup(aiop->aioproc);
1120 		}
1121 	}
1122 #endif /* VFS_AIO */
1123 }
1124 
1125 #ifdef VFS_AIO
1126 /*
1127  * Queue a new AIO request.  Choosing either the threaded or direct physio VCHR
1128  * technique is done in this code.
1129  */
1130 static int
1131 _aio_aqueue(struct proc *p, struct aiocb *job, struct aio_liojob *lj, int type)
1132 {
1133 	struct filedesc *fdp;
1134 	struct file *fp;
1135 	unsigned int fd;
1136 	struct socket *so;
1137 	int s;
1138 	int error;
1139 	int opcode, user_opcode;
1140 	struct aiocblist *aiocbe;
1141 	struct aioproclist *aiop;
1142 	struct kaioinfo *ki;
1143 	struct kevent kev;
1144 	struct kqueue *kq;
1145 	struct file *kq_fp;
1146 
1147 	if ((aiocbe = TAILQ_FIRST(&aio_freejobs)) != NULL)
1148 		TAILQ_REMOVE(&aio_freejobs, aiocbe, list);
1149 	else
1150 		aiocbe = zalloc (aiocb_zone);
1151 
1152 	aiocbe->inputcharge = 0;
1153 	aiocbe->outputcharge = 0;
1154 	callout_handle_init(&aiocbe->timeouthandle);
1155 	SLIST_INIT(&aiocbe->klist);
1156 
1157 	suword(&job->_aiocb_private.status, -1);
1158 	suword(&job->_aiocb_private.error, 0);
1159 	suword(&job->_aiocb_private.kernelinfo, -1);
1160 
1161 	error = copyin(job, &aiocbe->uaiocb, sizeof(aiocbe->uaiocb));
1162 	if (error) {
1163 		suword(&job->_aiocb_private.error, error);
1164 		TAILQ_INSERT_HEAD(&aio_freejobs, aiocbe, list);
1165 		return error;
1166 	}
1167 	if (aiocbe->uaiocb.aio_sigevent.sigev_notify == SIGEV_SIGNAL &&
1168 	    !_SIG_VALID(aiocbe->uaiocb.aio_sigevent.sigev_signo)) {
1169 		TAILQ_INSERT_HEAD(&aio_freejobs, aiocbe, list);
1170 		return EINVAL;
1171 	}
1172 
1173 	/* Save userspace address of the job info. */
1174 	aiocbe->uuaiocb = job;
1175 
1176 	/* Get the opcode. */
1177 	user_opcode = aiocbe->uaiocb.aio_lio_opcode;
1178 	if (type != LIO_NOP)
1179 		aiocbe->uaiocb.aio_lio_opcode = type;
1180 	opcode = aiocbe->uaiocb.aio_lio_opcode;
1181 
1182 	/* Get the fd info for process. */
1183 	fdp = p->p_fd;
1184 
1185 	/*
1186 	 * Range check file descriptor.
1187 	 */
1188 	fd = aiocbe->uaiocb.aio_fildes;
1189 	if (fd >= fdp->fd_nfiles) {
1190 		TAILQ_INSERT_HEAD(&aio_freejobs, aiocbe, list);
1191 		if (type == 0)
1192 			suword(&job->_aiocb_private.error, EBADF);
1193 		return EBADF;
1194 	}
1195 
1196 	fp = aiocbe->fd_file = fdp->fd_ofiles[fd];
1197 	if ((fp == NULL) || ((opcode == LIO_WRITE) && ((fp->f_flag & FWRITE) ==
1198 	    0))) {
1199 		TAILQ_INSERT_HEAD(&aio_freejobs, aiocbe, list);
1200 		if (type == 0)
1201 			suword(&job->_aiocb_private.error, EBADF);
1202 		return EBADF;
1203 	}
1204 	fhold(fp);
1205 
1206 	if (aiocbe->uaiocb.aio_offset == -1LL) {
1207 		error = EINVAL;
1208 		goto aqueue_fail;
1209 	}
1210 	error = suword(&job->_aiocb_private.kernelinfo, jobrefid);
1211 	if (error) {
1212 		error = EINVAL;
1213 		goto aqueue_fail;
1214 	}
1215 	aiocbe->uaiocb._aiocb_private.kernelinfo = (void *)(intptr_t)jobrefid;
1216 	if (jobrefid == LONG_MAX)
1217 		jobrefid = 1;
1218 	else
1219 		jobrefid++;
1220 
1221 	if (opcode == LIO_NOP) {
1222 		fdrop(fp, p);
1223 		TAILQ_INSERT_HEAD(&aio_freejobs, aiocbe, list);
1224 		if (type == 0) {
1225 			suword(&job->_aiocb_private.error, 0);
1226 			suword(&job->_aiocb_private.status, 0);
1227 			suword(&job->_aiocb_private.kernelinfo, 0);
1228 		}
1229 		return 0;
1230 	}
1231 	if ((opcode != LIO_READ) && (opcode != LIO_WRITE)) {
1232 		if (type == 0)
1233 			suword(&job->_aiocb_private.status, 0);
1234 		error = EINVAL;
1235 		goto aqueue_fail;
1236 	}
1237 
1238 	if (aiocbe->uaiocb.aio_sigevent.sigev_notify == SIGEV_KEVENT) {
1239 		kev.ident = aiocbe->uaiocb.aio_sigevent.sigev_notify_kqueue;
1240 		kev.udata = aiocbe->uaiocb.aio_sigevent.sigev_value.sigval_ptr;
1241 	}
1242 	else {
1243 		/*
1244 		 * This method for requesting kevent-based notification won't
1245 		 * work on the alpha, since we're passing in a pointer
1246 		 * via aio_lio_opcode, which is an int.  Use the SIGEV_KEVENT-
1247 		 * based method instead.
1248 		 */
1249 		if (user_opcode == LIO_NOP || user_opcode == LIO_READ ||
1250 		    user_opcode == LIO_WRITE)
1251 			goto no_kqueue;
1252 
1253 		error = copyin((struct kevent *)(uintptr_t)user_opcode,
1254 		    &kev, sizeof(kev));
1255 		if (error)
1256 			goto aqueue_fail;
1257 	}
1258 	if ((u_int)kev.ident >= fdp->fd_nfiles ||
1259 	    (kq_fp = fdp->fd_ofiles[kev.ident]) == NULL ||
1260 	    (kq_fp->f_type != DTYPE_KQUEUE)) {
1261 		error = EBADF;
1262 		goto aqueue_fail;
1263 	}
1264 	kq = (struct kqueue *)kq_fp->f_data;
1265 	kev.ident = (uintptr_t)aiocbe->uuaiocb;
1266 	kev.filter = EVFILT_AIO;
1267 	kev.flags = EV_ADD | EV_ENABLE | EV_FLAG1;
1268 	kev.data = (intptr_t)aiocbe;
1269 	error = kqueue_register(kq, &kev, p);
1270 aqueue_fail:
1271 	if (error) {
1272 		fdrop(fp, p);
1273 		TAILQ_INSERT_HEAD(&aio_freejobs, aiocbe, list);
1274 		if (type == 0)
1275 			suword(&job->_aiocb_private.error, error);
1276 		goto done;
1277 	}
1278 no_kqueue:
1279 
1280 	suword(&job->_aiocb_private.error, EINPROGRESS);
1281 	aiocbe->uaiocb._aiocb_private.error = EINPROGRESS;
1282 	aiocbe->userproc = p;
1283 	aiocbe->jobflags = 0;
1284 	aiocbe->lio = lj;
1285 	ki = p->p_aioinfo;
1286 
1287 	if (fp->f_type == DTYPE_SOCKET) {
1288 		/*
1289 		 * Alternate queueing for socket ops: Reach down into the
1290 		 * descriptor to get the socket data.  Then check to see if the
1291 		 * socket is ready to be read or written (based on the requested
1292 		 * operation).
1293 		 *
1294 		 * If it is not ready for io, then queue the aiocbe on the
1295 		 * socket, and set the flags so we get a call when sbnotify()
1296 		 * happens.
1297 		 */
1298 		so = (struct socket *)fp->f_data;
1299 		s = splnet();
1300 		if (((opcode == LIO_READ) && (!soreadable(so))) || ((opcode ==
1301 		    LIO_WRITE) && (!sowriteable(so)))) {
1302 			TAILQ_INSERT_TAIL(&so->so_aiojobq, aiocbe, list);
1303 			TAILQ_INSERT_TAIL(&ki->kaio_sockqueue, aiocbe, plist);
1304 			if (opcode == LIO_READ)
1305 				so->so_rcv.sb_flags |= SB_AIO;
1306 			else
1307 				so->so_snd.sb_flags |= SB_AIO;
1308 			aiocbe->jobstate = JOBST_JOBQGLOBAL; /* XXX */
1309 			ki->kaio_queue_count++;
1310 			num_queue_count++;
1311 			splx(s);
1312 			error = 0;
1313 			goto done;
1314 		}
1315 		splx(s);
1316 	}
1317 
1318 	if ((error = aio_qphysio(p, aiocbe)) == 0)
1319 		goto done;
1320 	if (error > 0) {
1321 		suword(&job->_aiocb_private.status, 0);
1322 		aiocbe->uaiocb._aiocb_private.error = error;
1323 		suword(&job->_aiocb_private.error, error);
1324 		goto done;
1325 	}
1326 
1327 	/* No buffer for daemon I/O. */
1328 	aiocbe->bp = NULL;
1329 
1330 	ki->kaio_queue_count++;
1331 	if (lj)
1332 		lj->lioj_queue_count++;
1333 	s = splnet();
1334 	TAILQ_INSERT_TAIL(&ki->kaio_jobqueue, aiocbe, plist);
1335 	TAILQ_INSERT_TAIL(&aio_jobs, aiocbe, list);
1336 	splx(s);
1337 	aiocbe->jobstate = JOBST_JOBQGLOBAL;
1338 
1339 	num_queue_count++;
1340 	error = 0;
1341 
1342 	/*
1343 	 * If we don't have a free AIO process, and we are below our quota, then
1344 	 * start one.  Otherwise, depend on the subsequent I/O completions to
1345 	 * pick-up this job.  If we don't sucessfully create the new process
1346 	 * (thread) due to resource issues, we return an error for now (EAGAIN),
1347 	 * which is likely not the correct thing to do.
1348 	 */
1349 	s = splnet();
1350 retryproc:
1351 	if ((aiop = TAILQ_FIRST(&aio_freeproc)) != NULL) {
1352 		TAILQ_REMOVE(&aio_freeproc, aiop, list);
1353 		TAILQ_INSERT_TAIL(&aio_activeproc, aiop, list);
1354 		aiop->aioprocflags &= ~AIOP_FREE;
1355 		wakeup(aiop->aioproc);
1356 	} else if (((num_aio_resv_start + num_aio_procs) < max_aio_procs) &&
1357 	    ((ki->kaio_active_count + num_aio_resv_start) <
1358 	    ki->kaio_maxactive_count)) {
1359 		num_aio_resv_start++;
1360 		if ((error = aio_newproc()) == 0) {
1361 			num_aio_resv_start--;
1362 			goto retryproc;
1363 		}
1364 		num_aio_resv_start--;
1365 	}
1366 	splx(s);
1367 done:
1368 	return error;
1369 }
1370 
1371 /*
1372  * This routine queues an AIO request, checking for quotas.
1373  */
1374 static int
1375 aio_aqueue(struct proc *p, struct aiocb *job, int type)
1376 {
1377 	struct kaioinfo *ki;
1378 
1379 	if (p->p_aioinfo == NULL)
1380 		aio_init_aioinfo(p);
1381 
1382 	if (num_queue_count >= max_queue_count)
1383 		return EAGAIN;
1384 
1385 	ki = p->p_aioinfo;
1386 	if (ki->kaio_queue_count >= ki->kaio_qallowed_count)
1387 		return EAGAIN;
1388 
1389 	return _aio_aqueue(p, job, NULL, type);
1390 }
1391 #endif /* VFS_AIO */
1392 
1393 /*
1394  * Support the aio_return system call, as a side-effect, kernel resources are
1395  * released.
1396  */
1397 int
1398 aio_return(struct proc *p, struct aio_return_args *uap)
1399 {
1400 #ifndef VFS_AIO
1401 	return ENOSYS;
1402 #else
1403 	int s;
1404 	long jobref;
1405 	struct aiocblist *cb, *ncb;
1406 	struct aiocb *ujob;
1407 	struct kaioinfo *ki;
1408 
1409 	ki = p->p_aioinfo;
1410 	if (ki == NULL)
1411 		return EINVAL;
1412 
1413 	ujob = uap->aiocbp;
1414 
1415 	jobref = fuword(&ujob->_aiocb_private.kernelinfo);
1416 	if (jobref == -1 || jobref == 0)
1417 		return EINVAL;
1418 
1419 	TAILQ_FOREACH(cb, &ki->kaio_jobdone, plist) {
1420 		if (((intptr_t) cb->uaiocb._aiocb_private.kernelinfo) ==
1421 		    jobref) {
1422 			if (ujob == cb->uuaiocb) {
1423 				p->p_retval[0] =
1424 				    cb->uaiocb._aiocb_private.status;
1425 			} else
1426 				p->p_retval[0] = EFAULT;
1427 			if (cb->uaiocb.aio_lio_opcode == LIO_WRITE) {
1428 				p->p_stats->p_ru.ru_oublock +=
1429 				    cb->outputcharge;
1430 				cb->outputcharge = 0;
1431 			} else if (cb->uaiocb.aio_lio_opcode == LIO_READ) {
1432 				p->p_stats->p_ru.ru_inblock += cb->inputcharge;
1433 				cb->inputcharge = 0;
1434 			}
1435 			aio_free_entry(cb);
1436 			return 0;
1437 		}
1438 	}
1439 	s = splbio();
1440 	for (cb = TAILQ_FIRST(&ki->kaio_bufdone); cb; cb = ncb) {
1441 		ncb = TAILQ_NEXT(cb, plist);
1442 		if (((intptr_t) cb->uaiocb._aiocb_private.kernelinfo)
1443 		    == jobref) {
1444 			splx(s);
1445 			if (ujob == cb->uuaiocb) {
1446 				p->p_retval[0] =
1447 				    cb->uaiocb._aiocb_private.status;
1448 			} else
1449 				p->p_retval[0] = EFAULT;
1450 			aio_free_entry(cb);
1451 			return 0;
1452 		}
1453 	}
1454 	splx(s);
1455 
1456 	return (EINVAL);
1457 #endif /* VFS_AIO */
1458 }
1459 
1460 /*
1461  * Allow a process to wakeup when any of the I/O requests are completed.
1462  */
1463 int
1464 aio_suspend(struct proc *p, struct aio_suspend_args *uap)
1465 {
1466 #ifndef VFS_AIO
1467 	return ENOSYS;
1468 #else
1469 	struct timeval atv;
1470 	struct timespec ts;
1471 	struct aiocb *const *cbptr, *cbp;
1472 	struct kaioinfo *ki;
1473 	struct aiocblist *cb;
1474 	int i;
1475 	int njoblist;
1476 	int error, s, timo;
1477 	long *ijoblist;
1478 	struct aiocb **ujoblist;
1479 
1480 	if (uap->nent > AIO_LISTIO_MAX)
1481 		return EINVAL;
1482 
1483 	timo = 0;
1484 	if (uap->timeout) {
1485 		/* Get timespec struct. */
1486 		if ((error = copyin(uap->timeout, &ts, sizeof(ts))) != 0)
1487 			return error;
1488 
1489 		if (ts.tv_nsec < 0 || ts.tv_nsec >= 1000000000)
1490 			return (EINVAL);
1491 
1492 		TIMESPEC_TO_TIMEVAL(&atv, &ts);
1493 		if (itimerfix(&atv))
1494 			return (EINVAL);
1495 		timo = tvtohz(&atv);
1496 	}
1497 
1498 	ki = p->p_aioinfo;
1499 	if (ki == NULL)
1500 		return EAGAIN;
1501 
1502 	njoblist = 0;
1503 	ijoblist = zalloc(aiol_zone);
1504 	ujoblist = zalloc(aiol_zone);
1505 	cbptr = uap->aiocbp;
1506 
1507 	for (i = 0; i < uap->nent; i++) {
1508 		cbp = (struct aiocb *)(intptr_t)fuword(&cbptr[i]);
1509 		if (cbp == 0)
1510 			continue;
1511 		ujoblist[njoblist] = cbp;
1512 		ijoblist[njoblist] = fuword(&cbp->_aiocb_private.kernelinfo);
1513 		njoblist++;
1514 	}
1515 
1516 	if (njoblist == 0) {
1517 		zfree(aiol_zone, ijoblist);
1518 		zfree(aiol_zone, ujoblist);
1519 		return 0;
1520 	}
1521 
1522 	error = 0;
1523 	for (;;) {
1524 		TAILQ_FOREACH(cb, &ki->kaio_jobdone, plist) {
1525 			for (i = 0; i < njoblist; i++) {
1526 				if (((intptr_t)
1527 				    cb->uaiocb._aiocb_private.kernelinfo) ==
1528 				    ijoblist[i]) {
1529 					if (ujoblist[i] != cb->uuaiocb)
1530 						error = EINVAL;
1531 					zfree(aiol_zone, ijoblist);
1532 					zfree(aiol_zone, ujoblist);
1533 					return error;
1534 				}
1535 			}
1536 		}
1537 
1538 		s = splbio();
1539 		for (cb = TAILQ_FIRST(&ki->kaio_bufdone); cb; cb =
1540 		    TAILQ_NEXT(cb, plist)) {
1541 			for (i = 0; i < njoblist; i++) {
1542 				if (((intptr_t)
1543 				    cb->uaiocb._aiocb_private.kernelinfo) ==
1544 				    ijoblist[i]) {
1545 					splx(s);
1546 					if (ujoblist[i] != cb->uuaiocb)
1547 						error = EINVAL;
1548 					zfree(aiol_zone, ijoblist);
1549 					zfree(aiol_zone, ujoblist);
1550 					return error;
1551 				}
1552 			}
1553 		}
1554 
1555 		ki->kaio_flags |= KAIO_WAKEUP;
1556 		error = tsleep(p, PRIBIO | PCATCH, "aiospn", timo);
1557 		splx(s);
1558 
1559 		if (error == ERESTART || error == EINTR) {
1560 			zfree(aiol_zone, ijoblist);
1561 			zfree(aiol_zone, ujoblist);
1562 			return EINTR;
1563 		} else if (error == EWOULDBLOCK) {
1564 			zfree(aiol_zone, ijoblist);
1565 			zfree(aiol_zone, ujoblist);
1566 			return EAGAIN;
1567 		}
1568 	}
1569 
1570 /* NOTREACHED */
1571 	return EINVAL;
1572 #endif /* VFS_AIO */
1573 }
1574 
1575 /*
1576  * aio_cancel cancels any non-physio aio operations not currently in
1577  * progress.
1578  */
1579 int
1580 aio_cancel(struct proc *p, struct aio_cancel_args *uap)
1581 {
1582 #ifndef VFS_AIO
1583 	return ENOSYS;
1584 #else
1585 	struct kaioinfo *ki;
1586 	struct aiocblist *cbe, *cbn;
1587 	struct file *fp;
1588 	struct filedesc *fdp;
1589 	struct socket *so;
1590 	struct proc *po;
1591 	int s,error;
1592 	int cancelled=0;
1593 	int notcancelled=0;
1594 	struct vnode *vp;
1595 
1596 	fdp = p->p_fd;
1597 	if ((u_int)uap->fd >= fdp->fd_nfiles ||
1598 	    (fp = fdp->fd_ofiles[uap->fd]) == NULL)
1599 		return (EBADF);
1600 
1601         if (fp->f_type == DTYPE_VNODE) {
1602 		vp = (struct vnode *)fp->f_data;
1603 
1604 		if (vn_isdisk(vp,&error)) {
1605 			p->p_retval[0] = AIO_NOTCANCELED;
1606         	        return 0;
1607 		}
1608 	} else if (fp->f_type == DTYPE_SOCKET) {
1609 		so = (struct socket *)fp->f_data;
1610 
1611 		s = splnet();
1612 
1613 		for (cbe = TAILQ_FIRST(&so->so_aiojobq); cbe; cbe = cbn) {
1614 			cbn = TAILQ_NEXT(cbe, list);
1615 			if ((uap->aiocbp == NULL) ||
1616 				(uap->aiocbp == cbe->uuaiocb) ) {
1617 				po = cbe->userproc;
1618 				ki = po->p_aioinfo;
1619 				TAILQ_REMOVE(&so->so_aiojobq, cbe, list);
1620 				TAILQ_REMOVE(&ki->kaio_sockqueue, cbe, plist);
1621 				TAILQ_INSERT_TAIL(&ki->kaio_jobdone, cbe, plist);
1622 				if (ki->kaio_flags & KAIO_WAKEUP) {
1623 					wakeup(po);
1624 				}
1625 				cbe->jobstate = JOBST_JOBFINISHED;
1626 				cbe->uaiocb._aiocb_private.status=-1;
1627 				cbe->uaiocb._aiocb_private.error=ECANCELED;
1628 				cancelled++;
1629 /* XXX cancelled, knote? */
1630 			        if (cbe->uaiocb.aio_sigevent.sigev_notify ==
1631 				    SIGEV_SIGNAL)
1632 					psignal(cbe->userproc, cbe->uaiocb.aio_sigevent.sigev_signo);
1633 				if (uap->aiocbp)
1634 					break;
1635 			}
1636 		}
1637 		splx(s);
1638 
1639 		if ((cancelled) && (uap->aiocbp)) {
1640 			p->p_retval[0] = AIO_CANCELED;
1641 			return 0;
1642 		}
1643 	}
1644 	ki=p->p_aioinfo;
1645 	if (ki == NULL)
1646 		goto done;
1647 	s = splnet();
1648 
1649 	for (cbe = TAILQ_FIRST(&ki->kaio_jobqueue); cbe; cbe = cbn) {
1650 		cbn = TAILQ_NEXT(cbe, plist);
1651 
1652 		if ((uap->fd == cbe->uaiocb.aio_fildes) &&
1653 		    ((uap->aiocbp == NULL ) ||
1654 		     (uap->aiocbp == cbe->uuaiocb))) {
1655 
1656 			if (cbe->jobstate == JOBST_JOBQGLOBAL) {
1657 				TAILQ_REMOVE(&aio_jobs, cbe, list);
1658                                 TAILQ_REMOVE(&ki->kaio_jobqueue, cbe, plist);
1659                                 TAILQ_INSERT_TAIL(&ki->kaio_jobdone, cbe,
1660                                     plist);
1661 				cancelled++;
1662 				ki->kaio_queue_finished_count++;
1663 				cbe->jobstate = JOBST_JOBFINISHED;
1664 				cbe->uaiocb._aiocb_private.status = -1;
1665 				cbe->uaiocb._aiocb_private.error = ECANCELED;
1666 /* XXX cancelled, knote? */
1667 			        if (cbe->uaiocb.aio_sigevent.sigev_notify ==
1668 				    SIGEV_SIGNAL)
1669 					psignal(cbe->userproc, cbe->uaiocb.aio_sigevent.sigev_signo);
1670 			} else {
1671 				notcancelled++;
1672 			}
1673 		}
1674 	}
1675 	splx(s);
1676 done:
1677 	if (notcancelled) {
1678 		p->p_retval[0] = AIO_NOTCANCELED;
1679 		return 0;
1680 	}
1681 	if (cancelled) {
1682 		p->p_retval[0] = AIO_CANCELED;
1683 		return 0;
1684 	}
1685 	p->p_retval[0] = AIO_ALLDONE;
1686 
1687 	return 0;
1688 #endif /* VFS_AIO */
1689 }
1690 
1691 /*
1692  * aio_error is implemented in the kernel level for compatibility purposes only.
1693  * For a user mode async implementation, it would be best to do it in a userland
1694  * subroutine.
1695  */
1696 int
1697 aio_error(struct proc *p, struct aio_error_args *uap)
1698 {
1699 #ifndef VFS_AIO
1700 	return ENOSYS;
1701 #else
1702 	int s;
1703 	struct aiocblist *cb;
1704 	struct kaioinfo *ki;
1705 	long jobref;
1706 
1707 	ki = p->p_aioinfo;
1708 	if (ki == NULL)
1709 		return EINVAL;
1710 
1711 	jobref = fuword(&uap->aiocbp->_aiocb_private.kernelinfo);
1712 	if ((jobref == -1) || (jobref == 0))
1713 		return EINVAL;
1714 
1715 	TAILQ_FOREACH(cb, &ki->kaio_jobdone, plist) {
1716 		if (((intptr_t)cb->uaiocb._aiocb_private.kernelinfo) ==
1717 		    jobref) {
1718 			p->p_retval[0] = cb->uaiocb._aiocb_private.error;
1719 			return 0;
1720 		}
1721 	}
1722 
1723 	s = splnet();
1724 
1725 	for (cb = TAILQ_FIRST(&ki->kaio_jobqueue); cb; cb = TAILQ_NEXT(cb,
1726 	    plist)) {
1727 		if (((intptr_t)cb->uaiocb._aiocb_private.kernelinfo) ==
1728 		    jobref) {
1729 			p->p_retval[0] = EINPROGRESS;
1730 			splx(s);
1731 			return 0;
1732 		}
1733 	}
1734 
1735 	for (cb = TAILQ_FIRST(&ki->kaio_sockqueue); cb; cb = TAILQ_NEXT(cb,
1736 	    plist)) {
1737 		if (((intptr_t)cb->uaiocb._aiocb_private.kernelinfo) ==
1738 		    jobref) {
1739 			p->p_retval[0] = EINPROGRESS;
1740 			splx(s);
1741 			return 0;
1742 		}
1743 	}
1744 	splx(s);
1745 
1746 	s = splbio();
1747 	for (cb = TAILQ_FIRST(&ki->kaio_bufdone); cb; cb = TAILQ_NEXT(cb,
1748 	    plist)) {
1749 		if (((intptr_t)cb->uaiocb._aiocb_private.kernelinfo) ==
1750 		    jobref) {
1751 			p->p_retval[0] = cb->uaiocb._aiocb_private.error;
1752 			splx(s);
1753 			return 0;
1754 		}
1755 	}
1756 
1757 	for (cb = TAILQ_FIRST(&ki->kaio_bufqueue); cb; cb = TAILQ_NEXT(cb,
1758 	    plist)) {
1759 		if (((intptr_t)cb->uaiocb._aiocb_private.kernelinfo) ==
1760 		    jobref) {
1761 			p->p_retval[0] = EINPROGRESS;
1762 			splx(s);
1763 			return 0;
1764 		}
1765 	}
1766 	splx(s);
1767 
1768 #if (0)
1769 	/*
1770 	 * Hack for lio.
1771 	 */
1772 	status = fuword(&uap->aiocbp->_aiocb_private.status);
1773 	if (status == -1)
1774 		return fuword(&uap->aiocbp->_aiocb_private.error);
1775 #endif
1776 	return EINVAL;
1777 #endif /* VFS_AIO */
1778 }
1779 
1780 /* syscall - asynchronous read from a file (REALTIME) */
1781 int
1782 aio_read(struct proc *p, struct aio_read_args *uap)
1783 {
1784 #ifndef VFS_AIO
1785 	return ENOSYS;
1786 #else
1787 	return aio_aqueue(p, uap->aiocbp, LIO_READ);
1788 #endif /* VFS_AIO */
1789 }
1790 
1791 /* syscall - asynchronous write to a file (REALTIME) */
1792 int
1793 aio_write(struct proc *p, struct aio_write_args *uap)
1794 {
1795 #ifndef VFS_AIO
1796 	return ENOSYS;
1797 #else
1798 	return aio_aqueue(p, uap->aiocbp, LIO_WRITE);
1799 #endif /* VFS_AIO */
1800 }
1801 
1802 /* syscall - XXX undocumented */
1803 int
1804 lio_listio(struct proc *p, struct lio_listio_args *uap)
1805 {
1806 #ifndef VFS_AIO
1807 	return ENOSYS;
1808 #else
1809 	int nent, nentqueued;
1810 	struct aiocb *iocb, * const *cbptr;
1811 	struct aiocblist *cb;
1812 	struct kaioinfo *ki;
1813 	struct aio_liojob *lj;
1814 	int error, runningcode;
1815 	int nerror;
1816 	int i;
1817 	int s;
1818 
1819 	if ((uap->mode != LIO_NOWAIT) && (uap->mode != LIO_WAIT))
1820 		return EINVAL;
1821 
1822 	nent = uap->nent;
1823 	if (nent > AIO_LISTIO_MAX)
1824 		return EINVAL;
1825 
1826 	if (p->p_aioinfo == NULL)
1827 		aio_init_aioinfo(p);
1828 
1829 	if ((nent + num_queue_count) > max_queue_count)
1830 		return EAGAIN;
1831 
1832 	ki = p->p_aioinfo;
1833 	if ((nent + ki->kaio_queue_count) > ki->kaio_qallowed_count)
1834 		return EAGAIN;
1835 
1836 	lj = zalloc(aiolio_zone);
1837 	if (!lj)
1838 		return EAGAIN;
1839 
1840 	lj->lioj_flags = 0;
1841 	lj->lioj_buffer_count = 0;
1842 	lj->lioj_buffer_finished_count = 0;
1843 	lj->lioj_queue_count = 0;
1844 	lj->lioj_queue_finished_count = 0;
1845 	lj->lioj_ki = ki;
1846 
1847 	/*
1848 	 * Setup signal.
1849 	 */
1850 	if (uap->sig && (uap->mode == LIO_NOWAIT)) {
1851 		error = copyin(uap->sig, &lj->lioj_signal,
1852 		    sizeof(lj->lioj_signal));
1853 		if (error) {
1854 			zfree(aiolio_zone, lj);
1855 			return error;
1856 		}
1857 		if (!_SIG_VALID(lj->lioj_signal.sigev_signo)) {
1858 			zfree(aiolio_zone, lj);
1859 			return EINVAL;
1860 		}
1861 		lj->lioj_flags |= LIOJ_SIGNAL;
1862 		lj->lioj_flags &= ~LIOJ_SIGNAL_POSTED;
1863 	} else
1864 		lj->lioj_flags &= ~LIOJ_SIGNAL;
1865 
1866 	TAILQ_INSERT_TAIL(&ki->kaio_liojoblist, lj, lioj_list);
1867 	/*
1868 	 * Get pointers to the list of I/O requests.
1869 	 */
1870 	nerror = 0;
1871 	nentqueued = 0;
1872 	cbptr = uap->acb_list;
1873 	for (i = 0; i < uap->nent; i++) {
1874 		iocb = (struct aiocb *)(intptr_t)fuword(&cbptr[i]);
1875 		if (((intptr_t)iocb != -1) && ((intptr_t)iocb != 0)) {
1876 			error = _aio_aqueue(p, iocb, lj, 0);
1877 			if (error == 0)
1878 				nentqueued++;
1879 			else
1880 				nerror++;
1881 		}
1882 	}
1883 
1884 	/*
1885 	 * If we haven't queued any, then just return error.
1886 	 */
1887 	if (nentqueued == 0)
1888 		return 0;
1889 
1890 	/*
1891 	 * Calculate the appropriate error return.
1892 	 */
1893 	runningcode = 0;
1894 	if (nerror)
1895 		runningcode = EIO;
1896 
1897 	if (uap->mode == LIO_WAIT) {
1898 		int command, found, jobref;
1899 
1900 		for (;;) {
1901 			found = 0;
1902 			for (i = 0; i < uap->nent; i++) {
1903 				/*
1904 				 * Fetch address of the control buf pointer in
1905 				 * user space.
1906 				 */
1907 				iocb = (struct aiocb *)
1908 				    (intptr_t)fuword(&cbptr[i]);
1909 				if (((intptr_t)iocb == -1) || ((intptr_t)iocb
1910 				    == 0))
1911 					continue;
1912 
1913 				/*
1914 				 * Fetch the associated command from user space.
1915 				 */
1916 				command = fuword(&iocb->aio_lio_opcode);
1917 				if (command == LIO_NOP) {
1918 					found++;
1919 					continue;
1920 				}
1921 
1922 				jobref = fuword(&iocb->_aiocb_private.kernelinfo);
1923 
1924 				TAILQ_FOREACH(cb, &ki->kaio_jobdone, plist) {
1925 					if (((intptr_t)cb->uaiocb._aiocb_private.kernelinfo)
1926 					    == jobref) {
1927 						if (cb->uaiocb.aio_lio_opcode
1928 						    == LIO_WRITE) {
1929 							p->p_stats->p_ru.ru_oublock
1930 							    +=
1931 							    cb->outputcharge;
1932 							cb->outputcharge = 0;
1933 						} else if (cb->uaiocb.aio_lio_opcode
1934 						    == LIO_READ) {
1935 							p->p_stats->p_ru.ru_inblock
1936 							    += cb->inputcharge;
1937 							cb->inputcharge = 0;
1938 						}
1939 						found++;
1940 						break;
1941 					}
1942 				}
1943 
1944 				s = splbio();
1945 				TAILQ_FOREACH(cb, &ki->kaio_bufdone, plist) {
1946 					if (((intptr_t)cb->uaiocb._aiocb_private.kernelinfo)
1947 					    == jobref) {
1948 						found++;
1949 						break;
1950 					}
1951 				}
1952 				splx(s);
1953 			}
1954 
1955 			/*
1956 			 * If all I/Os have been disposed of, then we can
1957 			 * return.
1958 			 */
1959 			if (found == nentqueued)
1960 				return runningcode;
1961 
1962 			ki->kaio_flags |= KAIO_WAKEUP;
1963 			error = tsleep(p, PRIBIO | PCATCH, "aiospn", 0);
1964 
1965 			if (error == EINTR)
1966 				return EINTR;
1967 			else if (error == EWOULDBLOCK)
1968 				return EAGAIN;
1969 		}
1970 	}
1971 
1972 	return runningcode;
1973 #endif /* VFS_AIO */
1974 }
1975 
1976 #ifdef VFS_AIO
1977 /*
1978  * This is a weird hack so that we can post a signal.  It is safe to do so from
1979  * a timeout routine, but *not* from an interrupt routine.
1980  */
1981 static void
1982 process_signal(void *aioj)
1983 {
1984 	struct aiocblist *aiocbe = aioj;
1985 	struct aio_liojob *lj = aiocbe->lio;
1986 	struct aiocb *cb = &aiocbe->uaiocb;
1987 
1988 	if ((lj) && (lj->lioj_signal.sigev_notify == SIGEV_SIGNAL) &&
1989 	    (lj->lioj_queue_count == lj->lioj_queue_finished_count)) {
1990 		psignal(lj->lioj_ki->kaio_p, lj->lioj_signal.sigev_signo);
1991 		lj->lioj_flags |= LIOJ_SIGNAL_POSTED;
1992 	}
1993 
1994 	if (cb->aio_sigevent.sigev_notify == SIGEV_SIGNAL)
1995 		psignal(aiocbe->userproc, cb->aio_sigevent.sigev_signo);
1996 }
1997 
1998 /*
1999  * Interrupt handler for physio, performs the necessary process wakeups, and
2000  * signals.
2001  */
2002 static void
2003 aio_physwakeup(struct buf *bp)
2004 {
2005 	struct aiocblist *aiocbe;
2006 	struct proc *p;
2007 	struct kaioinfo *ki;
2008 	struct aio_liojob *lj;
2009 
2010 	wakeup(bp);
2011 
2012 	aiocbe = (struct aiocblist *)bp->b_spc;
2013 	if (aiocbe) {
2014 		p = bp->b_caller1;
2015 
2016 		aiocbe->jobstate = JOBST_JOBBFINISHED;
2017 		aiocbe->uaiocb._aiocb_private.status -= bp->b_resid;
2018 		aiocbe->uaiocb._aiocb_private.error = 0;
2019 		aiocbe->jobflags |= AIOCBLIST_DONE;
2020 
2021 		if (bp->b_flags & B_ERROR)
2022 			aiocbe->uaiocb._aiocb_private.error = bp->b_error;
2023 
2024 		lj = aiocbe->lio;
2025 		if (lj) {
2026 			lj->lioj_buffer_finished_count++;
2027 
2028 			/*
2029 			 * wakeup/signal if all of the interrupt jobs are done.
2030 			 */
2031 			if (lj->lioj_buffer_finished_count ==
2032 			    lj->lioj_buffer_count) {
2033 				/*
2034 				 * Post a signal if it is called for.
2035 				 */
2036 				if ((lj->lioj_flags &
2037 				    (LIOJ_SIGNAL|LIOJ_SIGNAL_POSTED)) ==
2038 				    LIOJ_SIGNAL) {
2039 					lj->lioj_flags |= LIOJ_SIGNAL_POSTED;
2040 					aiocbe->timeouthandle =
2041 						timeout(process_signal,
2042 							aiocbe, 0);
2043 				}
2044 			}
2045 		}
2046 
2047 		ki = p->p_aioinfo;
2048 		if (ki) {
2049 			ki->kaio_buffer_finished_count++;
2050 			TAILQ_REMOVE(&aio_bufjobs, aiocbe, list);
2051 			TAILQ_REMOVE(&ki->kaio_bufqueue, aiocbe, plist);
2052 			TAILQ_INSERT_TAIL(&ki->kaio_bufdone, aiocbe, plist);
2053 
2054 			KNOTE(&aiocbe->klist, 0);
2055 			/* Do the wakeup. */
2056 			if (ki->kaio_flags & (KAIO_RUNDOWN|KAIO_WAKEUP)) {
2057 				ki->kaio_flags &= ~KAIO_WAKEUP;
2058 				wakeup(p);
2059 			}
2060 		}
2061 
2062 		if (aiocbe->uaiocb.aio_sigevent.sigev_notify == SIGEV_SIGNAL)
2063 			aiocbe->timeouthandle =
2064 				timeout(process_signal, aiocbe, 0);
2065 	}
2066 }
2067 #endif /* VFS_AIO */
2068 
2069 /* syscall - wait for the next completion of an aio request */
2070 int
2071 aio_waitcomplete(struct proc *p, struct aio_waitcomplete_args *uap)
2072 {
2073 #ifndef VFS_AIO
2074 	return ENOSYS;
2075 #else
2076 	struct timeval atv;
2077 	struct timespec ts;
2078 	struct kaioinfo *ki;
2079 	struct aiocblist *cb = NULL;
2080 	int error, s, timo;
2081 
2082 	suword(uap->aiocbp, (int)NULL);
2083 
2084 	timo = 0;
2085 	if (uap->timeout) {
2086 		/* Get timespec struct. */
2087 		error = copyin(uap->timeout, &ts, sizeof(ts));
2088 		if (error)
2089 			return error;
2090 
2091 		if ((ts.tv_nsec < 0) || (ts.tv_nsec >= 1000000000))
2092 			return (EINVAL);
2093 
2094 		TIMESPEC_TO_TIMEVAL(&atv, &ts);
2095 		if (itimerfix(&atv))
2096 			return (EINVAL);
2097 		timo = tvtohz(&atv);
2098 	}
2099 
2100 	ki = p->p_aioinfo;
2101 	if (ki == NULL)
2102 		return EAGAIN;
2103 
2104 	for (;;) {
2105 		if ((cb = TAILQ_FIRST(&ki->kaio_jobdone)) != 0) {
2106 			suword(uap->aiocbp, (uintptr_t)cb->uuaiocb);
2107 			p->p_retval[0] = cb->uaiocb._aiocb_private.status;
2108 			if (cb->uaiocb.aio_lio_opcode == LIO_WRITE) {
2109 				p->p_stats->p_ru.ru_oublock +=
2110 				    cb->outputcharge;
2111 				cb->outputcharge = 0;
2112 			} else if (cb->uaiocb.aio_lio_opcode == LIO_READ) {
2113 				p->p_stats->p_ru.ru_inblock += cb->inputcharge;
2114 				cb->inputcharge = 0;
2115 			}
2116 			aio_free_entry(cb);
2117 			return cb->uaiocb._aiocb_private.error;
2118 		}
2119 
2120 		s = splbio();
2121  		if ((cb = TAILQ_FIRST(&ki->kaio_bufdone)) != 0 ) {
2122 			splx(s);
2123 			suword(uap->aiocbp, (uintptr_t)cb->uuaiocb);
2124 			p->p_retval[0] = cb->uaiocb._aiocb_private.status;
2125 			aio_free_entry(cb);
2126 			return cb->uaiocb._aiocb_private.error;
2127 		}
2128 
2129 		ki->kaio_flags |= KAIO_WAKEUP;
2130 		error = tsleep(p, PRIBIO | PCATCH, "aiowc", timo);
2131 		splx(s);
2132 
2133 		if (error == ERESTART)
2134 			return EINTR;
2135 		else if (error < 0)
2136 			return error;
2137 		else if (error == EINTR)
2138 			return EINTR;
2139 		else if (error == EWOULDBLOCK)
2140 			return EAGAIN;
2141 	}
2142 #endif /* VFS_AIO */
2143 }
2144 
2145 #ifndef VFS_AIO
2146 static int
2147 filt_aioattach(struct knote *kn)
2148 {
2149 
2150 	return (ENXIO);
2151 }
2152 
2153 struct filterops aio_filtops =
2154 	{ 0, filt_aioattach, NULL, NULL };
2155 
2156 #else
2157 /* kqueue attach function */
2158 static int
2159 filt_aioattach(struct knote *kn)
2160 {
2161 	struct aiocblist *aiocbe = (struct aiocblist *)kn->kn_sdata;
2162 
2163 	/*
2164 	 * The aiocbe pointer must be validated before using it, so
2165 	 * registration is restricted to the kernel; the user cannot
2166 	 * set EV_FLAG1.
2167 	 */
2168 	if ((kn->kn_flags & EV_FLAG1) == 0)
2169 		return (EPERM);
2170 	kn->kn_flags &= ~EV_FLAG1;
2171 
2172 	SLIST_INSERT_HEAD(&aiocbe->klist, kn, kn_selnext);
2173 
2174 	return (0);
2175 }
2176 
2177 /* kqueue detach function */
2178 static void
2179 filt_aiodetach(struct knote *kn)
2180 {
2181 	struct aiocblist *aiocbe = (struct aiocblist *)kn->kn_sdata;
2182 
2183 	SLIST_REMOVE(&aiocbe->klist, kn, knote, kn_selnext);
2184 }
2185 
2186 /* kqueue filter function */
2187 /*ARGSUSED*/
2188 static int
2189 filt_aio(struct knote *kn, long hint)
2190 {
2191 	struct aiocblist *aiocbe = (struct aiocblist *)kn->kn_sdata;
2192 
2193 	kn->kn_data = aiocbe->uaiocb._aiocb_private.error;
2194 	if (aiocbe->jobstate != JOBST_JOBFINISHED &&
2195 	    aiocbe->jobstate != JOBST_JOBBFINISHED)
2196 		return (0);
2197 	kn->kn_flags |= EV_EOF;
2198 	return (1);
2199 }
2200 
2201 struct filterops aio_filtops =
2202 	{ 0, filt_aioattach, filt_aiodetach, filt_aio };
2203 #endif /* VFS_AIO */
2204