xref: /dragonfly/sys/kern/vfs_aio.c (revision 23265324)
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 1.35 2007/02/03 17:05:58 corecode Exp $
18  */
19 
20 /*
21  * This file contains support for the POSIX 1003.1B AIO/LIO facility.
22  */
23 
24 #include <sys/param.h>
25 #include <sys/systm.h>
26 #include <sys/buf.h>
27 #include <sys/sysproto.h>
28 #include <sys/filedesc.h>
29 #include <sys/kernel.h>
30 #include <sys/fcntl.h>
31 #include <sys/file.h>
32 #include <sys/lock.h>
33 #include <sys/unistd.h>
34 #include <sys/proc.h>
35 #include <sys/resourcevar.h>
36 #include <sys/signalvar.h>
37 #include <sys/protosw.h>
38 #include <sys/socketvar.h>
39 #include <sys/sysctl.h>
40 #include <sys/vnode.h>
41 #include <sys/conf.h>
42 #include <sys/event.h>
43 
44 #include <vm/vm.h>
45 #include <vm/vm_extern.h>
46 #include <vm/pmap.h>
47 #include <vm/vm_map.h>
48 #include <vm/vm_zone.h>
49 #include <sys/aio.h>
50 #include <sys/file2.h>
51 #include <sys/buf2.h>
52 #include <sys/thread2.h>
53 
54 #include <machine/limits.h>
55 #include "opt_vfs_aio.h"
56 
57 #ifdef VFS_AIO
58 
59 /*
60  * Counter for allocating reference ids to new jobs.  Wrapped to 1 on
61  * overflow.
62  */
63 static	long jobrefid;
64 
65 #define JOBST_NULL		0x0
66 #define JOBST_JOBQGLOBAL	0x2
67 #define JOBST_JOBRUNNING	0x3
68 #define JOBST_JOBFINISHED	0x4
69 #define	JOBST_JOBQBUF		0x5
70 #define	JOBST_JOBBFINISHED	0x6
71 
72 #ifndef MAX_AIO_PER_PROC
73 #define MAX_AIO_PER_PROC	32
74 #endif
75 
76 #ifndef MAX_AIO_QUEUE_PER_PROC
77 #define MAX_AIO_QUEUE_PER_PROC	256 /* Bigger than AIO_LISTIO_MAX */
78 #endif
79 
80 #ifndef MAX_AIO_PROCS
81 #define MAX_AIO_PROCS		32
82 #endif
83 
84 #ifndef MAX_AIO_QUEUE
85 #define	MAX_AIO_QUEUE		1024 /* Bigger than AIO_LISTIO_MAX */
86 #endif
87 
88 #ifndef TARGET_AIO_PROCS
89 #define TARGET_AIO_PROCS	4
90 #endif
91 
92 #ifndef MAX_BUF_AIO
93 #define MAX_BUF_AIO		16
94 #endif
95 
96 #ifndef AIOD_TIMEOUT_DEFAULT
97 #define	AIOD_TIMEOUT_DEFAULT	(10 * hz)
98 #endif
99 
100 #ifndef AIOD_LIFETIME_DEFAULT
101 #define AIOD_LIFETIME_DEFAULT	(30 * hz)
102 #endif
103 
104 SYSCTL_NODE(_vfs, OID_AUTO, aio, CTLFLAG_RW, 0, "Async IO management");
105 
106 static int max_aio_procs = MAX_AIO_PROCS;
107 SYSCTL_INT(_vfs_aio, OID_AUTO, max_aio_procs,
108 	CTLFLAG_RW, &max_aio_procs, 0,
109 	"Maximum number of kernel threads to use for handling async IO");
110 
111 static int num_aio_procs = 0;
112 SYSCTL_INT(_vfs_aio, OID_AUTO, num_aio_procs,
113 	CTLFLAG_RD, &num_aio_procs, 0,
114 	"Number of presently active kernel threads for async IO");
115 
116 /*
117  * The code will adjust the actual number of AIO processes towards this
118  * number when it gets a chance.
119  */
120 static int target_aio_procs = TARGET_AIO_PROCS;
121 SYSCTL_INT(_vfs_aio, OID_AUTO, target_aio_procs, CTLFLAG_RW, &target_aio_procs,
122 	0, "Preferred number of ready kernel threads for async IO");
123 
124 static int max_queue_count = MAX_AIO_QUEUE;
125 SYSCTL_INT(_vfs_aio, OID_AUTO, max_aio_queue, CTLFLAG_RW, &max_queue_count, 0,
126     "Maximum number of aio requests to queue, globally");
127 
128 static int num_queue_count = 0;
129 SYSCTL_INT(_vfs_aio, OID_AUTO, num_queue_count, CTLFLAG_RD, &num_queue_count, 0,
130     "Number of queued aio requests");
131 
132 static int num_buf_aio = 0;
133 SYSCTL_INT(_vfs_aio, OID_AUTO, num_buf_aio, CTLFLAG_RD, &num_buf_aio, 0,
134     "Number of aio requests presently handled by the buf subsystem");
135 
136 /* Number of async I/O thread in the process of being started */
137 /* XXX This should be local to _aio_aqueue() */
138 static int num_aio_resv_start = 0;
139 
140 static int aiod_timeout;
141 SYSCTL_INT(_vfs_aio, OID_AUTO, aiod_timeout, CTLFLAG_RW, &aiod_timeout, 0,
142     "Timeout value for synchronous aio operations");
143 
144 static int aiod_lifetime;
145 SYSCTL_INT(_vfs_aio, OID_AUTO, aiod_lifetime, CTLFLAG_RW, &aiod_lifetime, 0,
146     "Maximum lifetime for idle aiod");
147 
148 static int max_aio_per_proc = MAX_AIO_PER_PROC;
149 SYSCTL_INT(_vfs_aio, OID_AUTO, max_aio_per_proc, CTLFLAG_RW, &max_aio_per_proc,
150     0, "Maximum active aio requests per process (stored in the process)");
151 
152 static int max_aio_queue_per_proc = MAX_AIO_QUEUE_PER_PROC;
153 SYSCTL_INT(_vfs_aio, OID_AUTO, max_aio_queue_per_proc, CTLFLAG_RW,
154     &max_aio_queue_per_proc, 0,
155     "Maximum queued aio requests per process (stored in the process)");
156 
157 static int max_buf_aio = MAX_BUF_AIO;
158 SYSCTL_INT(_vfs_aio, OID_AUTO, max_buf_aio, CTLFLAG_RW, &max_buf_aio, 0,
159     "Maximum buf aio requests per process (stored in the process)");
160 
161 /*
162  * AIO process info
163  */
164 #define AIOP_FREE	0x1			/* proc on free queue */
165 #define AIOP_SCHED	0x2			/* proc explicitly scheduled */
166 
167 struct aioproclist {
168 	int aioprocflags;			/* AIO proc flags */
169 	TAILQ_ENTRY(aioproclist) list;		/* List of processes */
170 	struct proc *aioproc;			/* The AIO thread */
171 };
172 
173 /*
174  * data-structure for lio signal management
175  */
176 struct aio_liojob {
177 	int	lioj_flags;
178 	int	lioj_buffer_count;
179 	int	lioj_buffer_finished_count;
180 	int	lioj_queue_count;
181 	int	lioj_queue_finished_count;
182 	struct	sigevent lioj_signal;	/* signal on all I/O done */
183 	TAILQ_ENTRY(aio_liojob) lioj_list;
184 	struct	kaioinfo *lioj_ki;
185 };
186 #define	LIOJ_SIGNAL		0x1	/* signal on all done (lio) */
187 #define	LIOJ_SIGNAL_POSTED	0x2	/* signal has been posted */
188 
189 /*
190  * per process aio data structure
191  */
192 struct kaioinfo {
193 	int	kaio_flags;		/* per process kaio flags */
194 	int	kaio_maxactive_count;	/* maximum number of AIOs */
195 	int	kaio_active_count;	/* number of currently used AIOs */
196 	int	kaio_qallowed_count;	/* maxiumu size of AIO queue */
197 	int	kaio_queue_count;	/* size of AIO queue */
198 	int	kaio_ballowed_count;	/* maximum number of buffers */
199 	int	kaio_queue_finished_count; /* number of daemon jobs finished */
200 	int	kaio_buffer_count;	/* number of physio buffers */
201 	int	kaio_buffer_finished_count; /* count of I/O done */
202 	struct 	proc *kaio_p;		/* process that uses this kaio block */
203 	TAILQ_HEAD(,aio_liojob) kaio_liojoblist; /* list of lio jobs */
204 	TAILQ_HEAD(,aiocblist) kaio_jobqueue;	/* job queue for process */
205 	TAILQ_HEAD(,aiocblist) kaio_jobdone;	/* done queue for process */
206 	TAILQ_HEAD(,aiocblist) kaio_bufqueue;	/* buffer job queue for process */
207 	TAILQ_HEAD(,aiocblist) kaio_bufdone;	/* buffer done queue for process */
208 	TAILQ_HEAD(,aiocblist) kaio_sockqueue;	/* queue for aios waiting on sockets */
209 };
210 
211 #define KAIO_RUNDOWN	0x1	/* process is being run down */
212 #define KAIO_WAKEUP	0x2	/* wakeup process when there is a significant event */
213 
214 static TAILQ_HEAD(,aioproclist) aio_freeproc, aio_activeproc;
215 static TAILQ_HEAD(,aiocblist) aio_jobs;			/* Async job list */
216 static TAILQ_HEAD(,aiocblist) aio_bufjobs;		/* Phys I/O job list */
217 static TAILQ_HEAD(,aiocblist) aio_freejobs;		/* Pool of free jobs */
218 
219 static void	aio_init_aioinfo(struct proc *p);
220 static void	aio_onceonly(void *);
221 static int	aio_free_entry(struct aiocblist *aiocbe);
222 static void	aio_process(struct aiocblist *aiocbe);
223 static int	aio_newproc(void);
224 static int	aio_aqueue(struct aiocb *job, int type);
225 static void	aio_physwakeup(struct bio *bio);
226 static int	aio_fphysio(struct aiocblist *aiocbe);
227 static int	aio_qphysio(struct proc *p, struct aiocblist *iocb);
228 static void	aio_daemon(void *uproc);
229 static void	process_signal(void *aioj);
230 
231 SYSINIT(aio, SI_SUB_VFS, SI_ORDER_ANY, aio_onceonly, NULL);
232 
233 /*
234  * Zones for:
235  * 	kaio	Per process async io info
236  *	aiop	async io thread data
237  *	aiocb	async io jobs
238  *	aiol	list io job pointer - internal to aio_suspend XXX
239  *	aiolio	list io jobs
240  */
241 static vm_zone_t kaio_zone, aiop_zone, aiocb_zone, aiol_zone, aiolio_zone;
242 
243 /*
244  * Startup initialization
245  */
246 static void
247 aio_onceonly(void *na)
248 {
249 	TAILQ_INIT(&aio_freeproc);
250 	TAILQ_INIT(&aio_activeproc);
251 	TAILQ_INIT(&aio_jobs);
252 	TAILQ_INIT(&aio_bufjobs);
253 	TAILQ_INIT(&aio_freejobs);
254 	kaio_zone = zinit("AIO", sizeof(struct kaioinfo), 0, 0, 1);
255 	aiop_zone = zinit("AIOP", sizeof(struct aioproclist), 0, 0, 1);
256 	aiocb_zone = zinit("AIOCB", sizeof(struct aiocblist), 0, 0, 1);
257 	aiol_zone = zinit("AIOL", AIO_LISTIO_MAX*sizeof(intptr_t), 0, 0, 1);
258 	aiolio_zone = zinit("AIOLIO", sizeof(struct aio_liojob), 0, 0, 1);
259 	aiod_timeout = AIOD_TIMEOUT_DEFAULT;
260 	aiod_lifetime = AIOD_LIFETIME_DEFAULT;
261 	jobrefid = 1;
262 }
263 
264 /*
265  * Init the per-process aioinfo structure.  The aioinfo limits are set
266  * per-process for user limit (resource) management.
267  */
268 static void
269 aio_init_aioinfo(struct proc *p)
270 {
271 	struct kaioinfo *ki;
272 	if (p->p_aioinfo == NULL) {
273 		ki = zalloc(kaio_zone);
274 		p->p_aioinfo = ki;
275 		ki->kaio_flags = 0;
276 		ki->kaio_maxactive_count = max_aio_per_proc;
277 		ki->kaio_active_count = 0;
278 		ki->kaio_qallowed_count = max_aio_queue_per_proc;
279 		ki->kaio_queue_count = 0;
280 		ki->kaio_ballowed_count = max_buf_aio;
281 		ki->kaio_buffer_count = 0;
282 		ki->kaio_buffer_finished_count = 0;
283 		ki->kaio_p = p;
284 		TAILQ_INIT(&ki->kaio_jobdone);
285 		TAILQ_INIT(&ki->kaio_jobqueue);
286 		TAILQ_INIT(&ki->kaio_bufdone);
287 		TAILQ_INIT(&ki->kaio_bufqueue);
288 		TAILQ_INIT(&ki->kaio_liojoblist);
289 		TAILQ_INIT(&ki->kaio_sockqueue);
290 	}
291 
292 	while (num_aio_procs < target_aio_procs)
293 		aio_newproc();
294 }
295 
296 /*
297  * Free a job entry.  Wait for completion if it is currently active, but don't
298  * delay forever.  If we delay, we return a flag that says that we have to
299  * restart the queue scan.
300  */
301 static int
302 aio_free_entry(struct aiocblist *aiocbe)
303 {
304 	struct kaioinfo *ki;
305 	struct aio_liojob *lj;
306 	struct proc *p;
307 	int error;
308 
309 	if (aiocbe->jobstate == JOBST_NULL)
310 		panic("aio_free_entry: freeing already free job");
311 
312 	p = aiocbe->userproc;
313 	ki = p->p_aioinfo;
314 	lj = aiocbe->lio;
315 	if (ki == NULL)
316 		panic("aio_free_entry: missing p->p_aioinfo");
317 
318 	while (aiocbe->jobstate == JOBST_JOBRUNNING) {
319 		aiocbe->jobflags |= AIOCBLIST_RUNDOWN;
320 		tsleep(aiocbe, 0, "jobwai", 0);
321 	}
322 	if (aiocbe->bp == NULL) {
323 		if (ki->kaio_queue_count <= 0)
324 			panic("aio_free_entry: process queue size <= 0");
325 		if (num_queue_count <= 0)
326 			panic("aio_free_entry: system wide queue size <= 0");
327 
328 		if (lj) {
329 			lj->lioj_queue_count--;
330 			if (aiocbe->jobflags & AIOCBLIST_DONE)
331 				lj->lioj_queue_finished_count--;
332 		}
333 		ki->kaio_queue_count--;
334 		if (aiocbe->jobflags & AIOCBLIST_DONE)
335 			ki->kaio_queue_finished_count--;
336 		num_queue_count--;
337 	} else {
338 		if (lj) {
339 			lj->lioj_buffer_count--;
340 			if (aiocbe->jobflags & AIOCBLIST_DONE)
341 				lj->lioj_buffer_finished_count--;
342 		}
343 		if (aiocbe->jobflags & AIOCBLIST_DONE)
344 			ki->kaio_buffer_finished_count--;
345 		ki->kaio_buffer_count--;
346 		num_buf_aio--;
347 	}
348 
349 	/* aiocbe is going away, we need to destroy any knotes */
350 	/* XXX lwp knote wants a thread, but only cares about the process */
351 	knote_remove(FIRST_LWP_IN_PROC(p)->lwp_thread, &aiocbe->klist);
352 
353 	if ((ki->kaio_flags & KAIO_WAKEUP) || ((ki->kaio_flags & KAIO_RUNDOWN)
354 	    && ((ki->kaio_buffer_count == 0) && (ki->kaio_queue_count == 0)))) {
355 		ki->kaio_flags &= ~KAIO_WAKEUP;
356 		wakeup(p);
357 	}
358 
359 	if (aiocbe->jobstate == JOBST_JOBQBUF) {
360 		if ((error = aio_fphysio(aiocbe)) != 0)
361 			return error;
362 		if (aiocbe->jobstate != JOBST_JOBBFINISHED)
363 			panic("aio_free_entry: invalid physio finish-up state");
364 		crit_enter();
365 		TAILQ_REMOVE(&ki->kaio_bufdone, aiocbe, plist);
366 		crit_exit();
367 	} else if (aiocbe->jobstate == JOBST_JOBQGLOBAL) {
368 		crit_enter();
369 		TAILQ_REMOVE(&aio_jobs, aiocbe, list);
370 		TAILQ_REMOVE(&ki->kaio_jobqueue, aiocbe, plist);
371 		crit_exit();
372 	} else if (aiocbe->jobstate == JOBST_JOBFINISHED)
373 		TAILQ_REMOVE(&ki->kaio_jobdone, aiocbe, plist);
374 	else if (aiocbe->jobstate == JOBST_JOBBFINISHED) {
375 		crit_enter();
376 		TAILQ_REMOVE(&ki->kaio_bufdone, aiocbe, plist);
377 		crit_exit();
378 		if (aiocbe->bp) {
379 			vunmapbuf(aiocbe->bp);
380 			relpbuf(aiocbe->bp, NULL);
381 			aiocbe->bp = NULL;
382 		}
383 	}
384 	if (lj && (lj->lioj_buffer_count == 0) && (lj->lioj_queue_count == 0)) {
385 		TAILQ_REMOVE(&ki->kaio_liojoblist, lj, lioj_list);
386 		zfree(aiolio_zone, lj);
387 	}
388 	aiocbe->jobstate = JOBST_NULL;
389 	callout_stop(&aiocbe->timeout);
390 	fdrop(aiocbe->fd_file);
391 	TAILQ_INSERT_HEAD(&aio_freejobs, aiocbe, list);
392 	return 0;
393 }
394 #endif /* VFS_AIO */
395 
396 /*
397  * Rundown the jobs for a given process.
398  */
399 void
400 aio_proc_rundown(struct proc *p)
401 {
402 #ifndef VFS_AIO
403 	return;
404 #else
405 	struct kaioinfo *ki;
406 	struct aio_liojob *lj, *ljn;
407 	struct aiocblist *aiocbe, *aiocbn;
408 	struct file *fp;
409 	struct socket *so;
410 
411 	ki = p->p_aioinfo;
412 	if (ki == NULL)
413 		return;
414 
415 	ki->kaio_flags |= LIOJ_SIGNAL_POSTED;
416 	while ((ki->kaio_active_count > 0) || (ki->kaio_buffer_count >
417 	    ki->kaio_buffer_finished_count)) {
418 		ki->kaio_flags |= KAIO_RUNDOWN;
419 		if (tsleep(p, 0, "kaiowt", aiod_timeout))
420 			break;
421 	}
422 
423 	/*
424 	 * Move any aio ops that are waiting on socket I/O to the normal job
425 	 * queues so they are cleaned up with any others.
426 	 */
427 	crit_enter();
428 	for (aiocbe = TAILQ_FIRST(&ki->kaio_sockqueue); aiocbe; aiocbe =
429 	    aiocbn) {
430 		aiocbn = TAILQ_NEXT(aiocbe, plist);
431 		fp = aiocbe->fd_file;
432 		if (fp != NULL) {
433 			so = (struct socket *)fp->f_data;
434 			TAILQ_REMOVE(&so->so_aiojobq, aiocbe, list);
435 			if (TAILQ_EMPTY(&so->so_aiojobq)) {
436 				so->so_snd.sb_flags &= ~SB_AIO;
437 				so->so_rcv.sb_flags &= ~SB_AIO;
438 			}
439 		}
440 		TAILQ_REMOVE(&ki->kaio_sockqueue, aiocbe, plist);
441 		TAILQ_INSERT_HEAD(&aio_jobs, aiocbe, list);
442 		TAILQ_INSERT_HEAD(&ki->kaio_jobqueue, aiocbe, plist);
443 	}
444 	crit_exit();
445 
446 restart1:
447 	for (aiocbe = TAILQ_FIRST(&ki->kaio_jobdone); aiocbe; aiocbe = aiocbn) {
448 		aiocbn = TAILQ_NEXT(aiocbe, plist);
449 		if (aio_free_entry(aiocbe))
450 			goto restart1;
451 	}
452 
453 restart2:
454 	for (aiocbe = TAILQ_FIRST(&ki->kaio_jobqueue); aiocbe; aiocbe =
455 	    aiocbn) {
456 		aiocbn = TAILQ_NEXT(aiocbe, plist);
457 		if (aio_free_entry(aiocbe))
458 			goto restart2;
459 	}
460 
461 restart3:
462 	crit_enter();
463 	while (TAILQ_FIRST(&ki->kaio_bufqueue)) {
464 		ki->kaio_flags |= KAIO_WAKEUP;
465 		tsleep(p, 0, "aioprn", 0);
466 		crit_exit();
467 		goto restart3;
468 	}
469 	crit_exit();
470 
471 restart4:
472 	crit_enter();
473 	for (aiocbe = TAILQ_FIRST(&ki->kaio_bufdone); aiocbe; aiocbe = aiocbn) {
474 		aiocbn = TAILQ_NEXT(aiocbe, plist);
475 		if (aio_free_entry(aiocbe)) {
476 			crit_exit();
477 			goto restart4;
478 		}
479 	}
480 	crit_exit();
481 
482         /*
483          * If we've slept, jobs might have moved from one queue to another.
484          * Retry rundown if we didn't manage to empty the queues.
485          */
486         if (TAILQ_FIRST(&ki->kaio_jobdone) != NULL ||
487 	    TAILQ_FIRST(&ki->kaio_jobqueue) != NULL ||
488 	    TAILQ_FIRST(&ki->kaio_bufqueue) != NULL ||
489 	    TAILQ_FIRST(&ki->kaio_bufdone) != NULL)
490 		goto restart1;
491 
492 	for (lj = TAILQ_FIRST(&ki->kaio_liojoblist); lj; lj = ljn) {
493 		ljn = TAILQ_NEXT(lj, lioj_list);
494 		if ((lj->lioj_buffer_count == 0) && (lj->lioj_queue_count ==
495 		    0)) {
496 			TAILQ_REMOVE(&ki->kaio_liojoblist, lj, lioj_list);
497 			zfree(aiolio_zone, lj);
498 		} else {
499 #ifdef DIAGNOSTIC
500 			kprintf("LIO job not cleaned up: B:%d, BF:%d, Q:%d, "
501 			    "QF:%d\n", lj->lioj_buffer_count,
502 			    lj->lioj_buffer_finished_count,
503 			    lj->lioj_queue_count,
504 			    lj->lioj_queue_finished_count);
505 #endif
506 		}
507 	}
508 
509 	zfree(kaio_zone, ki);
510 	p->p_aioinfo = NULL;
511 #endif /* VFS_AIO */
512 }
513 
514 #ifdef VFS_AIO
515 /*
516  * Select a job to run (called by an AIO daemon).
517  */
518 static struct aiocblist *
519 aio_selectjob(struct aioproclist *aiop)
520 {
521 	struct aiocblist *aiocbe;
522 	struct kaioinfo *ki;
523 	struct proc *userp;
524 
525 	crit_enter();
526 	for (aiocbe = TAILQ_FIRST(&aio_jobs); aiocbe; aiocbe =
527 	    TAILQ_NEXT(aiocbe, list)) {
528 		userp = aiocbe->userproc;
529 		ki = userp->p_aioinfo;
530 
531 		if (ki->kaio_active_count < ki->kaio_maxactive_count) {
532 			TAILQ_REMOVE(&aio_jobs, aiocbe, list);
533 			crit_exit();
534 			return aiocbe;
535 		}
536 	}
537 	crit_exit();
538 
539 	return NULL;
540 }
541 
542 /*
543  * The AIO processing activity.  This is the code that does the I/O request for
544  * the non-physio version of the operations.  The normal vn operations are used,
545  * and this code should work in all instances for every type of file, including
546  * pipes, sockets, fifos, and regular files.
547  */
548 static void
549 aio_process(struct aiocblist *aiocbe)
550 {
551 	struct thread *mytd;
552 	struct aiocb *cb;
553 	struct file *fp;
554 	struct uio auio;
555 	struct iovec aiov;
556 	int cnt;
557 	int error;
558 	int oublock_st, oublock_end;
559 	int inblock_st, inblock_end;
560 
561 	mytd = curthread;
562 	cb = &aiocbe->uaiocb;
563 	fp = aiocbe->fd_file;
564 
565 	aiov.iov_base = (void *)(uintptr_t)cb->aio_buf;
566 	aiov.iov_len = cb->aio_nbytes;
567 
568 	auio.uio_iov = &aiov;
569 	auio.uio_iovcnt = 1;
570 	auio.uio_offset = cb->aio_offset;
571 	auio.uio_resid = cb->aio_nbytes;
572 	cnt = cb->aio_nbytes;
573 	auio.uio_segflg = UIO_USERSPACE;
574 	auio.uio_td = mytd;
575 
576 	inblock_st = mytd->td_lwp->lwp_ru.ru_inblock;
577 	oublock_st = mytd->td_lwp->lwp_ru.ru_oublock;
578 	/*
579 	 * _aio_aqueue() acquires a reference to the file that is
580 	 * released in aio_free_entry().
581 	 */
582 	if (cb->aio_lio_opcode == LIO_READ) {
583 		auio.uio_rw = UIO_READ;
584 		error = fo_read(fp, &auio, fp->f_cred, O_FOFFSET);
585 	} else {
586 		auio.uio_rw = UIO_WRITE;
587 		error = fo_write(fp, &auio, fp->f_cred, O_FOFFSET);
588 	}
589 	inblock_end = mytd->td_lwp->lwp_ru.ru_inblock;
590 	oublock_end = mytd->td_lwp->lwp_ru.ru_oublock;
591 
592 	aiocbe->inputcharge = inblock_end - inblock_st;
593 	aiocbe->outputcharge = oublock_end - oublock_st;
594 
595 	if ((error) && (auio.uio_resid != cnt)) {
596 		if (error == ERESTART || error == EINTR || error == EWOULDBLOCK)
597 			error = 0;
598 		if ((error == EPIPE) && (cb->aio_lio_opcode == LIO_WRITE))
599 			ksignal(aiocbe->userproc, SIGPIPE);
600 	}
601 
602 	cnt -= auio.uio_resid;
603 	cb->_aiocb_private.error = error;
604 	cb->_aiocb_private.status = cnt;
605 }
606 
607 /*
608  * The AIO daemon, most of the actual work is done in aio_process,
609  * but the setup (and address space mgmt) is done in this routine.
610  *
611  * The MP lock is held on entry.
612  */
613 static void
614 aio_daemon(void *uproc)
615 {
616 	struct aio_liojob *lj;
617 	struct aiocb *cb;
618 	struct aiocblist *aiocbe;
619 	struct aioproclist *aiop;
620 	struct kaioinfo *ki;
621 	struct proc *curcp, *mycp, *userp;
622 	struct vmspace *myvm, *tmpvm;
623 	struct ucred *cr;
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 	crit_enter();
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 	crit_exit();
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 	cr = cratom(&mycp->p_ucred);
666 	cr->cr_uid = 0;
667 	uireplace(&cr->cr_uidinfo, uifind(0));
668 	cr->cr_ngroups = 1;
669 	cr->cr_groups[0] = 1;
670 
671 	/* The daemon resides in its own pgrp. */
672 	enterpgrp(mycp, mycp->p_pid, 1);
673 
674 	/* Mark special process type. */
675 	mycp->p_flag |= P_SYSTEM | P_KTHREADP;
676 
677 	/*
678 	 * Wakeup parent process.  (Parent sleeps to keep from blasting away
679 	 * and creating too many daemons.)
680 	 */
681 	wakeup(mycp);
682 
683 	for (;;) {
684 		/*
685 		 * curcp is the current daemon process context.
686 		 * userp is the current user process context.
687 		 */
688 		curcp = mycp;
689 
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 (userp != curcp) {
715 				/*
716 				 * Save the current address space that we are
717 				 * connected to.
718 				 */
719 				tmpvm = mycp->p_vmspace;
720 
721 				/*
722 				 * Point to the new user address space, and
723 				 * refer to it.
724 				 */
725 				mycp->p_vmspace = userp->p_vmspace;
726 				mycp->p_vmspace->vm_refcnt++;
727 
728 				/* Activate the new mapping. */
729 				pmap_activate(mycp);
730 
731 				/*
732 				 * If the old address space wasn't the daemons
733 				 * own address space, then we need to remove the
734 				 * daemon's reference from the other process
735 				 * that it was acting on behalf of.
736 				 */
737 				if (tmpvm != myvm) {
738 					vmspace_free(tmpvm);
739 				}
740 				curcp = userp;
741 			}
742 
743 			ki = userp->p_aioinfo;
744 			lj = aiocbe->lio;
745 
746 			/* Account for currently active jobs. */
747 			ki->kaio_active_count++;
748 
749 			/* Do the I/O function. */
750 			aio_process(aiocbe);
751 
752 			/* Decrement the active job count. */
753 			ki->kaio_active_count--;
754 
755 			/*
756 			 * Increment the completion count for wakeup/signal
757 			 * comparisons.
758 			 */
759 			aiocbe->jobflags |= AIOCBLIST_DONE;
760 			ki->kaio_queue_finished_count++;
761 			if (lj)
762 				lj->lioj_queue_finished_count++;
763 			if ((ki->kaio_flags & KAIO_WAKEUP) || ((ki->kaio_flags
764 			    & KAIO_RUNDOWN) && (ki->kaio_active_count == 0))) {
765 				ki->kaio_flags &= ~KAIO_WAKEUP;
766 				wakeup(userp);
767 			}
768 
769 			crit_enter();
770 			if (lj && (lj->lioj_flags &
771 			    (LIOJ_SIGNAL|LIOJ_SIGNAL_POSTED)) == LIOJ_SIGNAL) {
772 				if ((lj->lioj_queue_finished_count ==
773 				    lj->lioj_queue_count) &&
774 				    (lj->lioj_buffer_finished_count ==
775 				    lj->lioj_buffer_count)) {
776 						ksignal(userp,
777 						    lj->lioj_signal.sigev_signo);
778 						lj->lioj_flags |=
779 						    LIOJ_SIGNAL_POSTED;
780 				}
781 			}
782 			crit_exit();
783 
784 			aiocbe->jobstate = JOBST_JOBFINISHED;
785 
786 			crit_enter();
787 			TAILQ_REMOVE(&ki->kaio_jobqueue, aiocbe, plist);
788 			TAILQ_INSERT_TAIL(&ki->kaio_jobdone, aiocbe, plist);
789 			crit_exit();
790 			KNOTE(&aiocbe->klist, 0);
791 
792 			if (aiocbe->jobflags & AIOCBLIST_RUNDOWN) {
793 				wakeup(aiocbe);
794 				aiocbe->jobflags &= ~AIOCBLIST_RUNDOWN;
795 			}
796 
797 			if (cb->aio_sigevent.sigev_notify == SIGEV_SIGNAL) {
798 				ksignal(userp, cb->aio_sigevent.sigev_signo);
799 			}
800 		}
801 
802 		/*
803 		 * Disconnect from user address space.
804 		 */
805 		if (curcp != mycp) {
806 			/* Get the user address space to disconnect from. */
807 			tmpvm = mycp->p_vmspace;
808 
809 			/* Get original address space for daemon. */
810 			mycp->p_vmspace = myvm;
811 
812 			/* Activate the daemon's address space. */
813 			pmap_activate(mycp);
814 #ifdef DIAGNOSTIC
815 			if (tmpvm == myvm) {
816 				kprintf("AIOD: vmspace problem -- %d\n",
817 				    mycp->p_pid);
818 			}
819 #endif
820 			/* Remove our vmspace reference. */
821 			vmspace_free(tmpvm);
822 
823 			curcp = mycp;
824 		}
825 
826 		/*
827 		 * If we are the first to be put onto the free queue, wakeup
828 		 * anyone waiting for a daemon.
829 		 */
830 		crit_enter();
831 		TAILQ_REMOVE(&aio_activeproc, aiop, list);
832 		if (TAILQ_EMPTY(&aio_freeproc))
833 			wakeup(&aio_freeproc);
834 		TAILQ_INSERT_HEAD(&aio_freeproc, aiop, list);
835 		aiop->aioprocflags |= AIOP_FREE;
836 		crit_exit();
837 
838 		/*
839 		 * If daemon is inactive for a long time, allow it to exit,
840 		 * thereby freeing resources.
841 		 */
842 		if (((aiop->aioprocflags & AIOP_SCHED) == 0) && tsleep(mycp,
843 		    0, "aiordy", aiod_lifetime)) {
844 			crit_enter();
845 			if (TAILQ_EMPTY(&aio_jobs)) {
846 				if ((aiop->aioprocflags & AIOP_FREE) &&
847 				    (num_aio_procs > target_aio_procs)) {
848 					TAILQ_REMOVE(&aio_freeproc, aiop, list);
849 					crit_exit();
850 					zfree(aiop_zone, aiop);
851 					num_aio_procs--;
852 #ifdef DIAGNOSTIC
853 					if (mycp->p_vmspace->vm_refcnt <= 1) {
854 						kprintf("AIOD: bad vm refcnt for"
855 						    " exiting daemon: %d\n",
856 						    mycp->p_vmspace->vm_refcnt);
857 					}
858 #endif
859 					exit1(0);
860 				}
861 			}
862 			crit_exit();
863 		}
864 	}
865 }
866 
867 /*
868  * Create a new AIO daemon.  This is mostly a kernel-thread fork routine.  The
869  * AIO daemon modifies its environment itself.
870  */
871 static int
872 aio_newproc(void)
873 {
874 	int error;
875 	struct lwp *lp, *nlp;
876 	struct proc *np;
877 
878 	lp = &lwp0;
879 	error = fork1(lp, RFPROC|RFMEM|RFNOWAIT, &np);
880 	if (error)
881 		return error;
882 	nlp = ONLY_LWP_IN_PROC(np);
883 	cpu_set_fork_handler(nlp, aio_daemon, curproc);
884 	start_forked_proc(lp, np);
885 
886 	/*
887 	 * Wait until daemon is started, but continue on just in case to
888 	 * handle error conditions.
889 	 */
890 	error = tsleep(np, 0, "aiosta", aiod_timeout);
891 	num_aio_procs++;
892 
893 	return error;
894 }
895 
896 /*
897  * Try the high-performance, low-overhead physio method for eligible
898  * VCHR devices.  This method doesn't use an aio helper thread, and
899  * thus has very low overhead.
900  *
901  * Assumes that the caller, _aio_aqueue(), has incremented the file
902  * structure's reference count, preventing its deallocation for the
903  * duration of this call.
904  */
905 static int
906 aio_qphysio(struct proc *p, struct aiocblist *aiocbe)
907 {
908 	int error;
909 	struct aiocb *cb;
910 	struct file *fp;
911 	struct buf *bp;
912 	struct vnode *vp;
913 	struct kaioinfo *ki;
914 	struct aio_liojob *lj;
915 	int notify;
916 
917 	cb = &aiocbe->uaiocb;
918 	fp = aiocbe->fd_file;
919 
920 	if (fp->f_type != DTYPE_VNODE)
921 		return (-1);
922 
923 	vp = (struct vnode *)fp->f_data;
924 
925 	/*
926 	 * If its not a disk, we don't want to return a positive error.
927 	 * It causes the aio code to not fall through to try the thread
928 	 * way when you're talking to a regular file.
929 	 */
930 	if (!vn_isdisk(vp, &error)) {
931 		if (error == ENOTBLK)
932 			return (-1);
933 		else
934 			return (error);
935 	}
936 
937  	if (cb->aio_nbytes % vp->v_rdev->si_bsize_phys)
938 		return (-1);
939 
940 	if (cb->aio_nbytes >
941 	    MAXPHYS - (((vm_offset_t) cb->aio_buf) & PAGE_MASK))
942 		return (-1);
943 
944 	ki = p->p_aioinfo;
945 	if (ki->kaio_buffer_count >= ki->kaio_ballowed_count)
946 		return (-1);
947 
948 	ki->kaio_buffer_count++;
949 
950 	lj = aiocbe->lio;
951 	if (lj)
952 		lj->lioj_buffer_count++;
953 
954 	/* Create and build a buffer header for a transfer. */
955 	bp = getpbuf(NULL);
956 	BUF_KERNPROC(bp);
957 
958 	/*
959 	 * Get a copy of the kva from the physical buffer.
960 	 */
961 	bp->b_bio1.bio_caller_info1.ptr = p;
962 	error = 0;
963 
964 	bp->b_cmd = (cb->aio_lio_opcode == LIO_WRITE) ?
965 		    BUF_CMD_WRITE : BUF_CMD_READ;
966 	bp->b_bio1.bio_done = aio_physwakeup;
967 	bp->b_bio1.bio_offset = cb->aio_offset;
968 
969 	/* Bring buffer into kernel space. */
970 	if (vmapbuf(bp, __DEVOLATILE(char *, cb->aio_buf), cb->aio_nbytes) < 0) {
971 		error = EFAULT;
972 		goto doerror;
973 	}
974 
975 	crit_enter();
976 
977 	aiocbe->bp = bp;
978 	bp->b_bio1.bio_caller_info2.ptr = aiocbe;
979 	TAILQ_INSERT_TAIL(&aio_bufjobs, aiocbe, list);
980 	TAILQ_INSERT_TAIL(&ki->kaio_bufqueue, aiocbe, plist);
981 	aiocbe->jobstate = JOBST_JOBQBUF;
982 	cb->_aiocb_private.status = cb->aio_nbytes;
983 	num_buf_aio++;
984 	bp->b_error = 0;
985 
986 	crit_exit();
987 
988 	/* Perform transfer. */
989 	dev_dstrategy(vp->v_rdev, &bp->b_bio1);
990 
991 	notify = 0;
992 	crit_enter();
993 
994 	/*
995 	 * If we had an error invoking the request, or an error in processing
996 	 * the request before we have returned, we process it as an error in
997 	 * transfer.  Note that such an I/O error is not indicated immediately,
998 	 * but is returned using the aio_error mechanism.  In this case,
999 	 * aio_suspend will return immediately.
1000 	 */
1001 	if (bp->b_error || (bp->b_flags & B_ERROR)) {
1002 		struct aiocb *job = aiocbe->uuaiocb;
1003 
1004 		aiocbe->uaiocb._aiocb_private.status = 0;
1005 		suword(&job->_aiocb_private.status, 0);
1006 		aiocbe->uaiocb._aiocb_private.error = bp->b_error;
1007 		suword(&job->_aiocb_private.error, bp->b_error);
1008 
1009 		ki->kaio_buffer_finished_count++;
1010 
1011 		if (aiocbe->jobstate != JOBST_JOBBFINISHED) {
1012 			aiocbe->jobstate = JOBST_JOBBFINISHED;
1013 			aiocbe->jobflags |= AIOCBLIST_DONE;
1014 			TAILQ_REMOVE(&aio_bufjobs, aiocbe, list);
1015 			TAILQ_REMOVE(&ki->kaio_bufqueue, aiocbe, plist);
1016 			TAILQ_INSERT_TAIL(&ki->kaio_bufdone, aiocbe, plist);
1017 			notify = 1;
1018 		}
1019 	}
1020 	crit_exit();
1021 	if (notify)
1022 		KNOTE(&aiocbe->klist, 0);
1023 	return 0;
1024 
1025 doerror:
1026 	ki->kaio_buffer_count--;
1027 	if (lj)
1028 		lj->lioj_buffer_count--;
1029 	aiocbe->bp = NULL;
1030 	relpbuf(bp, NULL);
1031 	return error;
1032 }
1033 
1034 /*
1035  * This waits/tests physio completion.
1036  */
1037 static int
1038 aio_fphysio(struct aiocblist *iocb)
1039 {
1040 	struct buf *bp;
1041 	int error;
1042 
1043 	bp = iocb->bp;
1044 
1045 	crit_enter();
1046 	while (bp->b_cmd != BUF_CMD_DONE) {
1047 		if (tsleep(bp, 0, "physstr", aiod_timeout)) {
1048 			if (bp->b_cmd != BUF_CMD_DONE) {
1049 				crit_exit();
1050 				return EINPROGRESS;
1051 			} else {
1052 				break;
1053 			}
1054 		}
1055 	}
1056 	crit_exit();
1057 
1058 	/* Release mapping into kernel space. */
1059 	vunmapbuf(bp);
1060 	iocb->bp = 0;
1061 
1062 	error = 0;
1063 
1064 	/* Check for an error. */
1065 	if (bp->b_flags & B_ERROR)
1066 		error = bp->b_error;
1067 
1068 	relpbuf(bp, NULL);
1069 	return (error);
1070 }
1071 #endif /* VFS_AIO */
1072 
1073 /*
1074  * Wake up aio requests that may be serviceable now.
1075  */
1076 void
1077 aio_swake(struct socket *so, struct sockbuf *sb)
1078 {
1079 #ifndef VFS_AIO
1080 	return;
1081 #else
1082 	struct aiocblist *cb,*cbn;
1083 	struct proc *p;
1084 	struct kaioinfo *ki = NULL;
1085 	int opcode, wakecount = 0;
1086 	struct aioproclist *aiop;
1087 
1088 	if (sb == &so->so_snd) {
1089 		opcode = LIO_WRITE;
1090 		so->so_snd.sb_flags &= ~SB_AIO;
1091 	} else {
1092 		opcode = LIO_READ;
1093 		so->so_rcv.sb_flags &= ~SB_AIO;
1094 	}
1095 
1096 	for (cb = TAILQ_FIRST(&so->so_aiojobq); cb; cb = cbn) {
1097 		cbn = TAILQ_NEXT(cb, list);
1098 		if (opcode == cb->uaiocb.aio_lio_opcode) {
1099 			p = cb->userproc;
1100 			ki = p->p_aioinfo;
1101 			TAILQ_REMOVE(&so->so_aiojobq, cb, list);
1102 			TAILQ_REMOVE(&ki->kaio_sockqueue, cb, plist);
1103 			TAILQ_INSERT_TAIL(&aio_jobs, cb, list);
1104 			TAILQ_INSERT_TAIL(&ki->kaio_jobqueue, cb, plist);
1105 			wakecount++;
1106 			if (cb->jobstate != JOBST_JOBQGLOBAL)
1107 				panic("invalid queue value");
1108 		}
1109 	}
1110 
1111 	while (wakecount--) {
1112 		if ((aiop = TAILQ_FIRST(&aio_freeproc)) != 0) {
1113 			TAILQ_REMOVE(&aio_freeproc, aiop, list);
1114 			TAILQ_INSERT_TAIL(&aio_activeproc, aiop, list);
1115 			aiop->aioprocflags &= ~AIOP_FREE;
1116 			wakeup(aiop->aioproc);
1117 		}
1118 	}
1119 #endif /* VFS_AIO */
1120 }
1121 
1122 #ifdef VFS_AIO
1123 /*
1124  * Queue a new AIO request.  Choosing either the threaded or direct physio VCHR
1125  * technique is done in this code.
1126  */
1127 static int
1128 _aio_aqueue(struct aiocb *job, struct aio_liojob *lj, int type)
1129 {
1130 	struct proc *p = curproc;
1131 	struct filedesc *fdp;
1132 	struct file *fp;
1133 	unsigned int fd;
1134 	struct socket *so;
1135 	int error;
1136 	int opcode, user_opcode;
1137 	struct aiocblist *aiocbe;
1138 	struct aioproclist *aiop;
1139 	struct kaioinfo *ki;
1140 	struct kevent kev;
1141 	struct kqueue *kq;
1142 	struct file *kq_fp;
1143 
1144 	if ((aiocbe = TAILQ_FIRST(&aio_freejobs)) != NULL)
1145 		TAILQ_REMOVE(&aio_freejobs, aiocbe, list);
1146 	else
1147 		aiocbe = zalloc (aiocb_zone);
1148 
1149 	aiocbe->inputcharge = 0;
1150 	aiocbe->outputcharge = 0;
1151 	callout_init(&aiocbe->timeout);
1152 	SLIST_INIT(&aiocbe->klist);
1153 
1154 	suword(&job->_aiocb_private.status, -1);
1155 	suword(&job->_aiocb_private.error, 0);
1156 	suword(&job->_aiocb_private.kernelinfo, -1);
1157 
1158 	error = copyin(job, &aiocbe->uaiocb, sizeof(aiocbe->uaiocb));
1159 	if (error) {
1160 		suword(&job->_aiocb_private.error, error);
1161 		TAILQ_INSERT_HEAD(&aio_freejobs, aiocbe, list);
1162 		return error;
1163 	}
1164 	if (aiocbe->uaiocb.aio_sigevent.sigev_notify == SIGEV_SIGNAL &&
1165 	    !_SIG_VALID(aiocbe->uaiocb.aio_sigevent.sigev_signo)) {
1166 		TAILQ_INSERT_HEAD(&aio_freejobs, aiocbe, list);
1167 		return EINVAL;
1168 	}
1169 
1170 	/* Save userspace address of the job info. */
1171 	aiocbe->uuaiocb = job;
1172 
1173 	/* Get the opcode. */
1174 	user_opcode = aiocbe->uaiocb.aio_lio_opcode;
1175 	if (type != LIO_NOP)
1176 		aiocbe->uaiocb.aio_lio_opcode = type;
1177 	opcode = aiocbe->uaiocb.aio_lio_opcode;
1178 
1179 	/* Get the fd info for process. */
1180 	fdp = p->p_fd;
1181 
1182 	/*
1183 	 * Range check file descriptor.
1184 	 */
1185 	fd = aiocbe->uaiocb.aio_fildes;
1186 	if (fd >= fdp->fd_nfiles) {
1187 		TAILQ_INSERT_HEAD(&aio_freejobs, aiocbe, list);
1188 		if (type == 0)
1189 			suword(&job->_aiocb_private.error, EBADF);
1190 		return EBADF;
1191 	}
1192 
1193 	fp = aiocbe->fd_file = fdp->fd_files[fd].fp;
1194 	if ((fp == NULL) || ((opcode == LIO_WRITE) && ((fp->f_flag & FWRITE) ==
1195 	    0))) {
1196 		TAILQ_INSERT_HEAD(&aio_freejobs, aiocbe, list);
1197 		if (type == 0)
1198 			suword(&job->_aiocb_private.error, EBADF);
1199 		return EBADF;
1200 	}
1201 	fhold(fp);
1202 
1203 	if (aiocbe->uaiocb.aio_offset == -1LL) {
1204 		error = EINVAL;
1205 		goto aqueue_fail;
1206 	}
1207 	error = suword(&job->_aiocb_private.kernelinfo, jobrefid);
1208 	if (error) {
1209 		error = EINVAL;
1210 		goto aqueue_fail;
1211 	}
1212 	aiocbe->uaiocb._aiocb_private.kernelinfo = (void *)(intptr_t)jobrefid;
1213 	if (jobrefid == LONG_MAX)
1214 		jobrefid = 1;
1215 	else
1216 		jobrefid++;
1217 
1218 	if (opcode == LIO_NOP) {
1219 		fdrop(fp);
1220 		TAILQ_INSERT_HEAD(&aio_freejobs, aiocbe, list);
1221 		if (type == 0) {
1222 			suword(&job->_aiocb_private.error, 0);
1223 			suword(&job->_aiocb_private.status, 0);
1224 			suword(&job->_aiocb_private.kernelinfo, 0);
1225 		}
1226 		return 0;
1227 	}
1228 	if ((opcode != LIO_READ) && (opcode != LIO_WRITE)) {
1229 		if (type == 0)
1230 			suword(&job->_aiocb_private.status, 0);
1231 		error = EINVAL;
1232 		goto aqueue_fail;
1233 	}
1234 
1235 	if (aiocbe->uaiocb.aio_sigevent.sigev_notify == SIGEV_KEVENT) {
1236 		kev.ident = aiocbe->uaiocb.aio_sigevent.sigev_notify_kqueue;
1237 		kev.udata = aiocbe->uaiocb.aio_sigevent.sigev_value.sigval_ptr;
1238 	}
1239 	else {
1240 		/*
1241 		 * This method for requesting kevent-based notification won't
1242 		 * work on the alpha, since we're passing in a pointer
1243 		 * via aio_lio_opcode, which is an int.  Use the SIGEV_KEVENT-
1244 		 * based method instead.
1245 		 */
1246 		if (user_opcode == LIO_NOP || user_opcode == LIO_READ ||
1247 		    user_opcode == LIO_WRITE)
1248 			goto no_kqueue;
1249 
1250 		error = copyin((struct kevent *)(uintptr_t)user_opcode,
1251 		    &kev, sizeof(kev));
1252 		if (error)
1253 			goto aqueue_fail;
1254 	}
1255 	if ((u_int)kev.ident >= fdp->fd_nfiles ||
1256 	    (kq_fp = fdp->fd_files[kev.ident].fp) == NULL ||
1257 	    (kq_fp->f_type != DTYPE_KQUEUE)) {
1258 		error = EBADF;
1259 		goto aqueue_fail;
1260 	}
1261 	kq = (struct kqueue *)kq_fp->f_data;
1262 	kev.ident = (uintptr_t)aiocbe->uuaiocb;
1263 	kev.filter = EVFILT_AIO;
1264 	kev.flags = EV_ADD | EV_ENABLE | EV_FLAG1;
1265 	kev.data = (intptr_t)aiocbe;
1266 	/* XXX lwp kqueue_register takes a thread, but only uses its proc */
1267 	error = kqueue_register(kq, &kev, FIRST_LWP_IN_PROC(p)->lwp_thread);
1268 aqueue_fail:
1269 	if (error) {
1270 		fdrop(fp);
1271 		TAILQ_INSERT_HEAD(&aio_freejobs, aiocbe, list);
1272 		if (type == 0)
1273 			suword(&job->_aiocb_private.error, error);
1274 		goto done;
1275 	}
1276 no_kqueue:
1277 
1278 	suword(&job->_aiocb_private.error, EINPROGRESS);
1279 	aiocbe->uaiocb._aiocb_private.error = EINPROGRESS;
1280 	aiocbe->userproc = p;
1281 	aiocbe->jobflags = 0;
1282 	aiocbe->lio = lj;
1283 	ki = p->p_aioinfo;
1284 
1285 	if (fp->f_type == DTYPE_SOCKET) {
1286 		/*
1287 		 * Alternate queueing for socket ops: Reach down into the
1288 		 * descriptor to get the socket data.  Then check to see if the
1289 		 * socket is ready to be read or written (based on the requested
1290 		 * operation).
1291 		 *
1292 		 * If it is not ready for io, then queue the aiocbe on the
1293 		 * socket, and set the flags so we get a call when sbnotify()
1294 		 * happens.
1295 		 */
1296 		so = (struct socket *)fp->f_data;
1297 		crit_enter();
1298 		if (((opcode == LIO_READ) && (!soreadable(so))) || ((opcode ==
1299 		    LIO_WRITE) && (!sowriteable(so)))) {
1300 			TAILQ_INSERT_TAIL(&so->so_aiojobq, aiocbe, list);
1301 			TAILQ_INSERT_TAIL(&ki->kaio_sockqueue, aiocbe, plist);
1302 			if (opcode == LIO_READ)
1303 				so->so_rcv.sb_flags |= SB_AIO;
1304 			else
1305 				so->so_snd.sb_flags |= SB_AIO;
1306 			aiocbe->jobstate = JOBST_JOBQGLOBAL; /* XXX */
1307 			ki->kaio_queue_count++;
1308 			num_queue_count++;
1309 			crit_exit();
1310 			error = 0;
1311 			goto done;
1312 		}
1313 		crit_exit();
1314 	}
1315 
1316 	if ((error = aio_qphysio(p, aiocbe)) == 0)
1317 		goto done;
1318 	if (error > 0) {
1319 		suword(&job->_aiocb_private.status, 0);
1320 		aiocbe->uaiocb._aiocb_private.error = error;
1321 		suword(&job->_aiocb_private.error, error);
1322 		goto done;
1323 	}
1324 
1325 	/* No buffer for daemon I/O. */
1326 	aiocbe->bp = NULL;
1327 
1328 	ki->kaio_queue_count++;
1329 	if (lj)
1330 		lj->lioj_queue_count++;
1331 	crit_enter();
1332 	TAILQ_INSERT_TAIL(&ki->kaio_jobqueue, aiocbe, plist);
1333 	TAILQ_INSERT_TAIL(&aio_jobs, aiocbe, list);
1334 	crit_exit();
1335 	aiocbe->jobstate = JOBST_JOBQGLOBAL;
1336 
1337 	num_queue_count++;
1338 	error = 0;
1339 
1340 	/*
1341 	 * If we don't have a free AIO process, and we are below our quota, then
1342 	 * start one.  Otherwise, depend on the subsequent I/O completions to
1343 	 * pick-up this job.  If we don't successfully create the new process
1344 	 * (thread) due to resource issues, we return an error for now (EAGAIN),
1345 	 * which is likely not the correct thing to do.
1346 	 */
1347 	crit_enter();
1348 retryproc:
1349 	if ((aiop = TAILQ_FIRST(&aio_freeproc)) != NULL) {
1350 		TAILQ_REMOVE(&aio_freeproc, aiop, list);
1351 		TAILQ_INSERT_TAIL(&aio_activeproc, aiop, list);
1352 		aiop->aioprocflags &= ~AIOP_FREE;
1353 		wakeup(aiop->aioproc);
1354 	} else if (((num_aio_resv_start + num_aio_procs) < max_aio_procs) &&
1355 	    ((ki->kaio_active_count + num_aio_resv_start) <
1356 	    ki->kaio_maxactive_count)) {
1357 		num_aio_resv_start++;
1358 		if ((error = aio_newproc()) == 0) {
1359 			num_aio_resv_start--;
1360 			goto retryproc;
1361 		}
1362 		num_aio_resv_start--;
1363 	}
1364 	crit_exit();
1365 done:
1366 	return error;
1367 }
1368 
1369 /*
1370  * This routine queues an AIO request, checking for quotas.
1371  */
1372 static int
1373 aio_aqueue(struct aiocb *job, int type)
1374 {
1375 	struct proc *p = curproc;
1376 	struct kaioinfo *ki;
1377 
1378 	if (p->p_aioinfo == NULL)
1379 		aio_init_aioinfo(p);
1380 
1381 	if (num_queue_count >= max_queue_count)
1382 		return EAGAIN;
1383 
1384 	ki = p->p_aioinfo;
1385 	if (ki->kaio_queue_count >= ki->kaio_qallowed_count)
1386 		return EAGAIN;
1387 
1388 	return _aio_aqueue(job, NULL, type);
1389 }
1390 #endif /* VFS_AIO */
1391 
1392 /*
1393  * Support the aio_return system call, as a side-effect, kernel resources are
1394  * released.
1395  */
1396 int
1397 sys_aio_return(struct aio_return_args *uap)
1398 {
1399 #ifndef VFS_AIO
1400 	return ENOSYS;
1401 #else
1402 	struct proc *p = curproc;
1403 	struct lwp *lp = curthread->td_lwp;
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 				uap->sysmsg_result =
1424 				    cb->uaiocb._aiocb_private.status;
1425 			} else
1426 				uap->sysmsg_result = EFAULT;
1427 			if (cb->uaiocb.aio_lio_opcode == LIO_WRITE) {
1428 				lp->lwp_ru.ru_oublock += cb->outputcharge;
1429 				cb->outputcharge = 0;
1430 			} else if (cb->uaiocb.aio_lio_opcode == LIO_READ) {
1431 				lp->lwp_ru.ru_inblock += cb->inputcharge;
1432 				cb->inputcharge = 0;
1433 			}
1434 			aio_free_entry(cb);
1435 			return 0;
1436 		}
1437 	}
1438 	crit_enter();
1439 	for (cb = TAILQ_FIRST(&ki->kaio_bufdone); cb; cb = ncb) {
1440 		ncb = TAILQ_NEXT(cb, plist);
1441 		if (((intptr_t) cb->uaiocb._aiocb_private.kernelinfo)
1442 		    == jobref) {
1443 			crit_exit();
1444 			if (ujob == cb->uuaiocb) {
1445 				uap->sysmsg_result =
1446 				    cb->uaiocb._aiocb_private.status;
1447 			} else
1448 				uap->sysmsg_result = EFAULT;
1449 			aio_free_entry(cb);
1450 			return 0;
1451 		}
1452 	}
1453 	crit_exit();
1454 
1455 	return (EINVAL);
1456 #endif /* VFS_AIO */
1457 }
1458 
1459 /*
1460  * Allow a process to wakeup when any of the I/O requests are completed.
1461  */
1462 int
1463 sys_aio_suspend(struct aio_suspend_args *uap)
1464 {
1465 #ifndef VFS_AIO
1466 	return ENOSYS;
1467 #else
1468 	struct proc *p = curproc;
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, 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_high(&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 		crit_enter();
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 					crit_exit();
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, PCATCH, "aiospn", timo);
1557 		crit_exit();
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 sys_aio_cancel(struct aio_cancel_args *uap)
1581 {
1582 #ifndef VFS_AIO
1583 	return ENOSYS;
1584 #else
1585 	struct proc *p = curproc;
1586 	struct kaioinfo *ki;
1587 	struct aiocblist *cbe, *cbn;
1588 	struct file *fp;
1589 	struct filedesc *fdp;
1590 	struct socket *so;
1591 	struct proc *po;
1592 	int error;
1593 	int cancelled=0;
1594 	int notcancelled=0;
1595 	struct vnode *vp;
1596 
1597 	fdp = p->p_fd;
1598 	if ((u_int)uap->fd >= fdp->fd_nfiles ||
1599 	    (fp = fdp->fd_files[uap->fd].fp) == NULL)
1600 		return (EBADF);
1601 
1602         if (fp->f_type == DTYPE_VNODE) {
1603 		vp = (struct vnode *)fp->f_data;
1604 
1605 		if (vn_isdisk(vp,&error)) {
1606 			uap->sysmsg_result = AIO_NOTCANCELED;
1607         	        return 0;
1608 		}
1609 	} else if (fp->f_type == DTYPE_SOCKET) {
1610 		so = (struct socket *)fp->f_data;
1611 
1612 		crit_enter();
1613 
1614 		for (cbe = TAILQ_FIRST(&so->so_aiojobq); cbe; cbe = cbn) {
1615 			cbn = TAILQ_NEXT(cbe, list);
1616 			if ((uap->aiocbp == NULL) ||
1617 				(uap->aiocbp == cbe->uuaiocb) ) {
1618 				po = cbe->userproc;
1619 				ki = po->p_aioinfo;
1620 				TAILQ_REMOVE(&so->so_aiojobq, cbe, list);
1621 				TAILQ_REMOVE(&ki->kaio_sockqueue, cbe, plist);
1622 				TAILQ_INSERT_TAIL(&ki->kaio_jobdone, cbe, plist);
1623 				if (ki->kaio_flags & KAIO_WAKEUP) {
1624 					wakeup(po);
1625 				}
1626 				cbe->jobstate = JOBST_JOBFINISHED;
1627 				cbe->uaiocb._aiocb_private.status=-1;
1628 				cbe->uaiocb._aiocb_private.error=ECANCELED;
1629 				cancelled++;
1630 /* XXX cancelled, knote? */
1631 			        if (cbe->uaiocb.aio_sigevent.sigev_notify ==
1632 				    SIGEV_SIGNAL)
1633 					ksignal(cbe->userproc, cbe->uaiocb.aio_sigevent.sigev_signo);
1634 				if (uap->aiocbp)
1635 					break;
1636 			}
1637 		}
1638 		crit_exit();
1639 
1640 		if ((cancelled) && (uap->aiocbp)) {
1641 			uap->sysmsg_result = AIO_CANCELED;
1642 			return 0;
1643 		}
1644 	}
1645 	ki=p->p_aioinfo;
1646 	if (ki == NULL)
1647 		goto done;
1648 	crit_enter();
1649 
1650 	for (cbe = TAILQ_FIRST(&ki->kaio_jobqueue); cbe; cbe = cbn) {
1651 		cbn = TAILQ_NEXT(cbe, plist);
1652 
1653 		if ((uap->fd == cbe->uaiocb.aio_fildes) &&
1654 		    ((uap->aiocbp == NULL ) ||
1655 		     (uap->aiocbp == cbe->uuaiocb))) {
1656 
1657 			if (cbe->jobstate == JOBST_JOBQGLOBAL) {
1658 				TAILQ_REMOVE(&aio_jobs, cbe, list);
1659                                 TAILQ_REMOVE(&ki->kaio_jobqueue, cbe, plist);
1660                                 TAILQ_INSERT_TAIL(&ki->kaio_jobdone, cbe,
1661                                     plist);
1662 				cancelled++;
1663 				ki->kaio_queue_finished_count++;
1664 				cbe->jobstate = JOBST_JOBFINISHED;
1665 				cbe->uaiocb._aiocb_private.status = -1;
1666 				cbe->uaiocb._aiocb_private.error = ECANCELED;
1667 /* XXX cancelled, knote? */
1668 			        if (cbe->uaiocb.aio_sigevent.sigev_notify ==
1669 				    SIGEV_SIGNAL)
1670 					ksignal(cbe->userproc, cbe->uaiocb.aio_sigevent.sigev_signo);
1671 			} else {
1672 				notcancelled++;
1673 			}
1674 		}
1675 	}
1676 	crit_exit();
1677 done:
1678 	if (notcancelled) {
1679 		uap->sysmsg_result = AIO_NOTCANCELED;
1680 		return 0;
1681 	}
1682 	if (cancelled) {
1683 		uap->sysmsg_result = AIO_CANCELED;
1684 		return 0;
1685 	}
1686 	uap->sysmsg_result = AIO_ALLDONE;
1687 
1688 	return 0;
1689 #endif /* VFS_AIO */
1690 }
1691 
1692 /*
1693  * aio_error is implemented in the kernel level for compatibility purposes only.
1694  * For a user mode async implementation, it would be best to do it in a userland
1695  * subroutine.
1696  */
1697 int
1698 sys_aio_error(struct aio_error_args *uap)
1699 {
1700 #ifndef VFS_AIO
1701 	return ENOSYS;
1702 #else
1703 	struct proc *p = curproc;
1704 	struct aiocblist *cb;
1705 	struct kaioinfo *ki;
1706 	long jobref;
1707 
1708 	ki = p->p_aioinfo;
1709 	if (ki == NULL)
1710 		return EINVAL;
1711 
1712 	jobref = fuword(&uap->aiocbp->_aiocb_private.kernelinfo);
1713 	if ((jobref == -1) || (jobref == 0))
1714 		return EINVAL;
1715 
1716 	TAILQ_FOREACH(cb, &ki->kaio_jobdone, plist) {
1717 		if (((intptr_t)cb->uaiocb._aiocb_private.kernelinfo) ==
1718 		    jobref) {
1719 			uap->sysmsg_result = cb->uaiocb._aiocb_private.error;
1720 			return 0;
1721 		}
1722 	}
1723 
1724 	crit_enter();
1725 
1726 	for (cb = TAILQ_FIRST(&ki->kaio_jobqueue); cb; cb = TAILQ_NEXT(cb,
1727 	    plist)) {
1728 		if (((intptr_t)cb->uaiocb._aiocb_private.kernelinfo) ==
1729 		    jobref) {
1730 			uap->sysmsg_result = EINPROGRESS;
1731 			crit_exit();
1732 			return 0;
1733 		}
1734 	}
1735 
1736 	for (cb = TAILQ_FIRST(&ki->kaio_sockqueue); cb; cb = TAILQ_NEXT(cb,
1737 	    plist)) {
1738 		if (((intptr_t)cb->uaiocb._aiocb_private.kernelinfo) ==
1739 		    jobref) {
1740 			uap->sysmsg_result = EINPROGRESS;
1741 			crit_exit();
1742 			return 0;
1743 		}
1744 	}
1745 	crit_exit();
1746 
1747 	crit_enter();
1748 	for (cb = TAILQ_FIRST(&ki->kaio_bufdone); cb; cb = TAILQ_NEXT(cb,
1749 	    plist)) {
1750 		if (((intptr_t)cb->uaiocb._aiocb_private.kernelinfo) ==
1751 		    jobref) {
1752 			uap->sysmsg_result = cb->uaiocb._aiocb_private.error;
1753 			crit_exit();
1754 			return 0;
1755 		}
1756 	}
1757 
1758 	for (cb = TAILQ_FIRST(&ki->kaio_bufqueue); cb; cb = TAILQ_NEXT(cb,
1759 	    plist)) {
1760 		if (((intptr_t)cb->uaiocb._aiocb_private.kernelinfo) ==
1761 		    jobref) {
1762 			uap->sysmsg_result = EINPROGRESS;
1763 			crit_exit();
1764 			return 0;
1765 		}
1766 	}
1767 	crit_exit();
1768 
1769 #if (0)
1770 	/*
1771 	 * Hack for lio.
1772 	 */
1773 	status = fuword(&uap->aiocbp->_aiocb_private.status);
1774 	if (status == -1)
1775 		return fuword(&uap->aiocbp->_aiocb_private.error);
1776 #endif
1777 	return EINVAL;
1778 #endif /* VFS_AIO */
1779 }
1780 
1781 /* syscall - asynchronous read from a file (REALTIME) */
1782 int
1783 sys_aio_read(struct aio_read_args *uap)
1784 {
1785 #ifndef VFS_AIO
1786 	return ENOSYS;
1787 #else
1788 	return aio_aqueue(uap->aiocbp, LIO_READ);
1789 #endif /* VFS_AIO */
1790 }
1791 
1792 /* syscall - asynchronous write to a file (REALTIME) */
1793 int
1794 sys_aio_write(struct aio_write_args *uap)
1795 {
1796 #ifndef VFS_AIO
1797 	return ENOSYS;
1798 #else
1799 	return aio_aqueue(uap->aiocbp, LIO_WRITE);
1800 #endif /* VFS_AIO */
1801 }
1802 
1803 /* syscall - XXX undocumented */
1804 int
1805 sys_lio_listio(struct lio_listio_args *uap)
1806 {
1807 #ifndef VFS_AIO
1808 	return ENOSYS;
1809 #else
1810 	struct proc *p = curproc;
1811 	struct lwp *lp = curthread->td_lwp;
1812 	int nent, nentqueued;
1813 	struct aiocb *iocb, * const *cbptr;
1814 	struct aiocblist *cb;
1815 	struct kaioinfo *ki;
1816 	struct aio_liojob *lj;
1817 	int error, runningcode;
1818 	int nerror;
1819 	int i;
1820 
1821 	if ((uap->mode != LIO_NOWAIT) && (uap->mode != LIO_WAIT))
1822 		return EINVAL;
1823 
1824 	nent = uap->nent;
1825 	if (nent > AIO_LISTIO_MAX)
1826 		return EINVAL;
1827 
1828 	if (p->p_aioinfo == NULL)
1829 		aio_init_aioinfo(p);
1830 
1831 	if ((nent + num_queue_count) > max_queue_count)
1832 		return EAGAIN;
1833 
1834 	ki = p->p_aioinfo;
1835 	if ((nent + ki->kaio_queue_count) > ki->kaio_qallowed_count)
1836 		return EAGAIN;
1837 
1838 	lj = zalloc(aiolio_zone);
1839 	if (!lj)
1840 		return EAGAIN;
1841 
1842 	lj->lioj_flags = 0;
1843 	lj->lioj_buffer_count = 0;
1844 	lj->lioj_buffer_finished_count = 0;
1845 	lj->lioj_queue_count = 0;
1846 	lj->lioj_queue_finished_count = 0;
1847 	lj->lioj_ki = ki;
1848 
1849 	/*
1850 	 * Setup signal.
1851 	 */
1852 	if (uap->sig && (uap->mode == LIO_NOWAIT)) {
1853 		error = copyin(uap->sig, &lj->lioj_signal,
1854 		    sizeof(lj->lioj_signal));
1855 		if (error) {
1856 			zfree(aiolio_zone, lj);
1857 			return error;
1858 		}
1859 		if (!_SIG_VALID(lj->lioj_signal.sigev_signo)) {
1860 			zfree(aiolio_zone, lj);
1861 			return EINVAL;
1862 		}
1863 		lj->lioj_flags |= LIOJ_SIGNAL;
1864 		lj->lioj_flags &= ~LIOJ_SIGNAL_POSTED;
1865 	} else
1866 		lj->lioj_flags &= ~LIOJ_SIGNAL;
1867 
1868 	TAILQ_INSERT_TAIL(&ki->kaio_liojoblist, lj, lioj_list);
1869 	/*
1870 	 * Get pointers to the list of I/O requests.
1871 	 */
1872 	nerror = 0;
1873 	nentqueued = 0;
1874 	cbptr = uap->acb_list;
1875 	for (i = 0; i < uap->nent; i++) {
1876 		iocb = (struct aiocb *)(intptr_t)fuword(&cbptr[i]);
1877 		if (((intptr_t)iocb != -1) && ((intptr_t)iocb != 0)) {
1878 			error = _aio_aqueue(iocb, lj, 0);
1879 			if (error == 0)
1880 				nentqueued++;
1881 			else
1882 				nerror++;
1883 		}
1884 	}
1885 
1886 	/*
1887 	 * If we haven't queued any, then just return error.
1888 	 */
1889 	if (nentqueued == 0)
1890 		return 0;
1891 
1892 	/*
1893 	 * Calculate the appropriate error return.
1894 	 */
1895 	runningcode = 0;
1896 	if (nerror)
1897 		runningcode = EIO;
1898 
1899 	if (uap->mode == LIO_WAIT) {
1900 		int command, found, jobref;
1901 
1902 		for (;;) {
1903 			found = 0;
1904 			for (i = 0; i < uap->nent; i++) {
1905 				/*
1906 				 * Fetch address of the control buf pointer in
1907 				 * user space.
1908 				 */
1909 				iocb = (struct aiocb *)
1910 				    (intptr_t)fuword(&cbptr[i]);
1911 				if (((intptr_t)iocb == -1) || ((intptr_t)iocb
1912 				    == 0))
1913 					continue;
1914 
1915 				/*
1916 				 * Fetch the associated command from user space.
1917 				 */
1918 				command = fuword(&iocb->aio_lio_opcode);
1919 				if (command == LIO_NOP) {
1920 					found++;
1921 					continue;
1922 				}
1923 
1924 				jobref = fuword(&iocb->_aiocb_private.kernelinfo);
1925 
1926 				TAILQ_FOREACH(cb, &ki->kaio_jobdone, plist) {
1927 					if (((intptr_t)cb->uaiocb._aiocb_private.kernelinfo)
1928 					    == jobref) {
1929 						if (cb->uaiocb.aio_lio_opcode
1930 						    == LIO_WRITE) {
1931 							lp->lwp_ru.ru_oublock +=
1932 							    cb->outputcharge;
1933 							cb->outputcharge = 0;
1934 						} else if (cb->uaiocb.aio_lio_opcode
1935 						    == LIO_READ) {
1936 							lp->lwp_ru.ru_inblock +=
1937 							    cb->inputcharge;
1938 							cb->inputcharge = 0;
1939 						}
1940 						found++;
1941 						break;
1942 					}
1943 				}
1944 
1945 				crit_enter();
1946 				TAILQ_FOREACH(cb, &ki->kaio_bufdone, plist) {
1947 					if (((intptr_t)cb->uaiocb._aiocb_private.kernelinfo)
1948 					    == jobref) {
1949 						found++;
1950 						break;
1951 					}
1952 				}
1953 				crit_exit();
1954 			}
1955 
1956 			/*
1957 			 * If all I/Os have been disposed of, then we can
1958 			 * return.
1959 			 */
1960 			if (found == nentqueued)
1961 				return runningcode;
1962 
1963 			ki->kaio_flags |= KAIO_WAKEUP;
1964 			error = tsleep(p, PCATCH, "aiospn", 0);
1965 
1966 			if (error == EINTR)
1967 				return EINTR;
1968 			else if (error == EWOULDBLOCK)
1969 				return EAGAIN;
1970 		}
1971 	}
1972 
1973 	return runningcode;
1974 #endif /* VFS_AIO */
1975 }
1976 
1977 #ifdef VFS_AIO
1978 /*
1979  * This is a weird hack so that we can post a signal.  It is safe to do so from
1980  * a timeout routine, but *not* from an interrupt routine.
1981  */
1982 static void
1983 process_signal(void *aioj)
1984 {
1985 	struct aiocblist *aiocbe = aioj;
1986 	struct aio_liojob *lj = aiocbe->lio;
1987 	struct aiocb *cb = &aiocbe->uaiocb;
1988 
1989 	if ((lj) && (lj->lioj_signal.sigev_notify == SIGEV_SIGNAL) &&
1990 	    (lj->lioj_queue_count == lj->lioj_queue_finished_count)) {
1991 		ksignal(lj->lioj_ki->kaio_p, lj->lioj_signal.sigev_signo);
1992 		lj->lioj_flags |= LIOJ_SIGNAL_POSTED;
1993 	}
1994 
1995 	if (cb->aio_sigevent.sigev_notify == SIGEV_SIGNAL)
1996 		ksignal(aiocbe->userproc, cb->aio_sigevent.sigev_signo);
1997 }
1998 
1999 /*
2000  * Interrupt handler for physio, performs the necessary process wakeups, and
2001  * signals.
2002  */
2003 static void
2004 aio_physwakeup(struct bio *bio)
2005 {
2006 	struct buf *bp = bio->bio_buf;
2007 	struct aiocblist *aiocbe;
2008 	struct proc *p;
2009 	struct kaioinfo *ki;
2010 	struct aio_liojob *lj;
2011 
2012 	aiocbe = bio->bio_caller_info2.ptr;
2013 
2014 	if (aiocbe) {
2015 		p = bio->bio_caller_info1.ptr;
2016 
2017 		aiocbe->jobstate = JOBST_JOBBFINISHED;
2018 		aiocbe->uaiocb._aiocb_private.status -= bp->b_resid;
2019 		aiocbe->uaiocb._aiocb_private.error = 0;
2020 		aiocbe->jobflags |= AIOCBLIST_DONE;
2021 
2022 		if (bp->b_flags & B_ERROR)
2023 			aiocbe->uaiocb._aiocb_private.error = bp->b_error;
2024 
2025 		lj = aiocbe->lio;
2026 		if (lj) {
2027 			lj->lioj_buffer_finished_count++;
2028 
2029 			/*
2030 			 * wakeup/signal if all of the interrupt jobs are done.
2031 			 */
2032 			if (lj->lioj_buffer_finished_count ==
2033 			    lj->lioj_buffer_count) {
2034 				/*
2035 				 * Post a signal if it is called for.
2036 				 */
2037 				if ((lj->lioj_flags &
2038 				    (LIOJ_SIGNAL|LIOJ_SIGNAL_POSTED)) ==
2039 				    LIOJ_SIGNAL) {
2040 					lj->lioj_flags |= LIOJ_SIGNAL_POSTED;
2041 					callout_reset(&aiocbe->timeout, 0,
2042 							process_signal, aiocbe);
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 			callout_reset(&aiocbe->timeout, 0,
2064 					process_signal, aiocbe);
2065 		}
2066 	}
2067 	bp->b_cmd = BUF_CMD_DONE;
2068 	wakeup(bp);
2069 }
2070 #endif /* VFS_AIO */
2071 
2072 /* syscall - wait for the next completion of an aio request */
2073 int
2074 sys_aio_waitcomplete(struct aio_waitcomplete_args *uap)
2075 {
2076 #ifndef VFS_AIO
2077 	return ENOSYS;
2078 #else
2079 	struct proc *p = curproc;
2080 	struct lwp *lp = curthread->td_lwp;
2081 	struct timeval atv;
2082 	struct timespec ts;
2083 	struct kaioinfo *ki;
2084 	struct aiocblist *cb = NULL;
2085 	int error, timo;
2086 
2087 	suword(uap->aiocbp, (int)NULL);
2088 
2089 	timo = 0;
2090 	if (uap->timeout) {
2091 		/* Get timespec struct. */
2092 		error = copyin(uap->timeout, &ts, sizeof(ts));
2093 		if (error)
2094 			return error;
2095 
2096 		if ((ts.tv_nsec < 0) || (ts.tv_nsec >= 1000000000))
2097 			return (EINVAL);
2098 
2099 		TIMESPEC_TO_TIMEVAL(&atv, &ts);
2100 		if (itimerfix(&atv))
2101 			return (EINVAL);
2102 		timo = tvtohz_high(&atv);
2103 	}
2104 
2105 	ki = p->p_aioinfo;
2106 	if (ki == NULL)
2107 		return EAGAIN;
2108 
2109 	for (;;) {
2110 		if ((cb = TAILQ_FIRST(&ki->kaio_jobdone)) != 0) {
2111 			suword(uap->aiocbp, (uintptr_t)cb->uuaiocb);
2112 			uap->sysmsg_result = cb->uaiocb._aiocb_private.status;
2113 			if (cb->uaiocb.aio_lio_opcode == LIO_WRITE) {
2114 				lp->lwp_ru.ru_oublock +=
2115 				    cb->outputcharge;
2116 				cb->outputcharge = 0;
2117 			} else if (cb->uaiocb.aio_lio_opcode == LIO_READ) {
2118 				lp->lwp_ru.ru_inblock += cb->inputcharge;
2119 				cb->inputcharge = 0;
2120 			}
2121 			aio_free_entry(cb);
2122 			return cb->uaiocb._aiocb_private.error;
2123 		}
2124 
2125 		crit_enter();
2126  		if ((cb = TAILQ_FIRST(&ki->kaio_bufdone)) != 0 ) {
2127 			crit_exit();
2128 			suword(uap->aiocbp, (uintptr_t)cb->uuaiocb);
2129 			uap->sysmsg_result = cb->uaiocb._aiocb_private.status;
2130 			aio_free_entry(cb);
2131 			return cb->uaiocb._aiocb_private.error;
2132 		}
2133 
2134 		ki->kaio_flags |= KAIO_WAKEUP;
2135 		error = tsleep(p, PCATCH, "aiowc", timo);
2136 		crit_exit();
2137 
2138 		if (error == ERESTART)
2139 			return EINTR;
2140 		else if (error < 0)
2141 			return error;
2142 		else if (error == EINTR)
2143 			return EINTR;
2144 		else if (error == EWOULDBLOCK)
2145 			return EAGAIN;
2146 	}
2147 #endif /* VFS_AIO */
2148 }
2149 
2150 #ifndef VFS_AIO
2151 static int
2152 filt_aioattach(struct knote *kn)
2153 {
2154 
2155 	return (ENXIO);
2156 }
2157 
2158 struct filterops aio_filtops =
2159 	{ 0, filt_aioattach, NULL, NULL };
2160 
2161 #else
2162 /* kqueue attach function */
2163 static int
2164 filt_aioattach(struct knote *kn)
2165 {
2166 	struct aiocblist *aiocbe = (struct aiocblist *)kn->kn_sdata;
2167 
2168 	/*
2169 	 * The aiocbe pointer must be validated before using it, so
2170 	 * registration is restricted to the kernel; the user cannot
2171 	 * set EV_FLAG1.
2172 	 */
2173 	if ((kn->kn_flags & EV_FLAG1) == 0)
2174 		return (EPERM);
2175 	kn->kn_flags &= ~EV_FLAG1;
2176 
2177 	SLIST_INSERT_HEAD(&aiocbe->klist, kn, kn_selnext);
2178 
2179 	return (0);
2180 }
2181 
2182 /* kqueue detach function */
2183 static void
2184 filt_aiodetach(struct knote *kn)
2185 {
2186 	struct aiocblist *aiocbe = (struct aiocblist *)kn->kn_sdata;
2187 
2188 	SLIST_REMOVE(&aiocbe->klist, kn, knote, kn_selnext);
2189 }
2190 
2191 /* kqueue filter function */
2192 /*ARGSUSED*/
2193 static int
2194 filt_aio(struct knote *kn, long hint)
2195 {
2196 	struct aiocblist *aiocbe = (struct aiocblist *)kn->kn_sdata;
2197 
2198 	kn->kn_data = aiocbe->uaiocb._aiocb_private.error;
2199 	if (aiocbe->jobstate != JOBST_JOBFINISHED &&
2200 	    aiocbe->jobstate != JOBST_JOBBFINISHED)
2201 		return (0);
2202 	kn->kn_flags |= EV_EOF;
2203 	return (1);
2204 }
2205 
2206 struct filterops aio_filtops =
2207 	{ 0, filt_aioattach, filt_aiodetach, filt_aio };
2208 #endif /* VFS_AIO */
2209