xref: /freebsd/sys/kern/vfs_aio.c (revision a220d00e74dd245b4fca59c5eca0c53963686325)
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  * $FreeBSD$
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/bio.h>
26 #include <sys/buf.h>
27 #include <sys/sysproto.h>
28 #include <sys/filedesc.h>
29 #include <sys/kernel.h>
30 #include <sys/kthread.h>
31 #include <sys/fcntl.h>
32 #include <sys/file.h>
33 #include <sys/lock.h>
34 #include <sys/mutex.h>
35 #include <sys/unistd.h>
36 #include <sys/proc.h>
37 #include <sys/resourcevar.h>
38 #include <sys/signalvar.h>
39 #include <sys/protosw.h>
40 #include <sys/socketvar.h>
41 #include <sys/sysctl.h>
42 #include <sys/vnode.h>
43 #include <sys/conf.h>
44 #include <sys/event.h>
45 
46 #include <vm/vm.h>
47 #include <vm/vm_extern.h>
48 #include <vm/pmap.h>
49 #include <vm/vm_map.h>
50 #include <vm/vm_zone.h>
51 #include <sys/aio.h>
52 
53 #include <machine/limits.h>
54 
55 #include "opt_vfs_aio.h"
56 
57 #ifdef VFS_AIO
58 
59 static	long jobrefid;
60 
61 #define JOBST_NULL		0x0
62 #define	JOBST_JOBQPROC		0x1
63 #define JOBST_JOBQGLOBAL	0x2
64 #define JOBST_JOBRUNNING	0x3
65 #define JOBST_JOBFINISHED	0x4
66 #define	JOBST_JOBQBUF		0x5
67 #define	JOBST_JOBBFINISHED	0x6
68 
69 #ifndef MAX_AIO_PER_PROC
70 #define MAX_AIO_PER_PROC	32
71 #endif
72 
73 #ifndef MAX_AIO_QUEUE_PER_PROC
74 #define MAX_AIO_QUEUE_PER_PROC	256 /* Bigger than AIO_LISTIO_MAX */
75 #endif
76 
77 #ifndef MAX_AIO_PROCS
78 #define MAX_AIO_PROCS		32
79 #endif
80 
81 #ifndef MAX_AIO_QUEUE
82 #define	MAX_AIO_QUEUE		1024 /* Bigger than AIO_LISTIO_MAX */
83 #endif
84 
85 #ifndef TARGET_AIO_PROCS
86 #define TARGET_AIO_PROCS	4
87 #endif
88 
89 #ifndef MAX_BUF_AIO
90 #define MAX_BUF_AIO		16
91 #endif
92 
93 #ifndef AIOD_TIMEOUT_DEFAULT
94 #define	AIOD_TIMEOUT_DEFAULT	(10 * hz)
95 #endif
96 
97 #ifndef AIOD_LIFETIME_DEFAULT
98 #define AIOD_LIFETIME_DEFAULT	(30 * hz)
99 #endif
100 
101 static int max_aio_procs = MAX_AIO_PROCS;
102 static int num_aio_procs = 0;
103 static int target_aio_procs = TARGET_AIO_PROCS;
104 static int max_queue_count = MAX_AIO_QUEUE;
105 static int num_queue_count = 0;
106 static int num_buf_aio = 0;
107 static int num_aio_resv_start = 0;
108 static int aiod_timeout;
109 static int aiod_lifetime;
110 
111 static int max_aio_per_proc = MAX_AIO_PER_PROC;
112 static int max_aio_queue_per_proc = MAX_AIO_QUEUE_PER_PROC;
113 static int max_buf_aio = MAX_BUF_AIO;
114 
115 SYSCTL_NODE(_vfs, OID_AUTO, aio, CTLFLAG_RW, 0, "AIO mgmt");
116 
117 SYSCTL_INT(_vfs_aio, OID_AUTO, max_aio_per_proc,
118 	CTLFLAG_RW, &max_aio_per_proc, 0, "");
119 
120 SYSCTL_INT(_vfs_aio, OID_AUTO, max_aio_queue_per_proc,
121 	CTLFLAG_RW, &max_aio_queue_per_proc, 0, "");
122 
123 SYSCTL_INT(_vfs_aio, OID_AUTO, max_aio_procs,
124 	CTLFLAG_RW, &max_aio_procs, 0, "");
125 
126 SYSCTL_INT(_vfs_aio, OID_AUTO, num_aio_procs,
127 	CTLFLAG_RD, &num_aio_procs, 0, "");
128 
129 SYSCTL_INT(_vfs_aio, OID_AUTO, num_queue_count,
130 	CTLFLAG_RD, &num_queue_count, 0, "");
131 
132 SYSCTL_INT(_vfs_aio, OID_AUTO, max_aio_queue,
133 	CTLFLAG_RW, &max_queue_count, 0, "");
134 
135 SYSCTL_INT(_vfs_aio, OID_AUTO, target_aio_procs,
136 	CTLFLAG_RW, &target_aio_procs, 0, "");
137 
138 SYSCTL_INT(_vfs_aio, OID_AUTO, max_buf_aio,
139 	CTLFLAG_RW, &max_buf_aio, 0, "");
140 
141 SYSCTL_INT(_vfs_aio, OID_AUTO, num_buf_aio,
142 	CTLFLAG_RD, &num_buf_aio, 0, "");
143 
144 SYSCTL_INT(_vfs_aio, OID_AUTO, aiod_lifetime,
145 	CTLFLAG_RW, &aiod_lifetime, 0, "");
146 
147 SYSCTL_INT(_vfs_aio, OID_AUTO, aiod_timeout,
148 	CTLFLAG_RW, &aiod_timeout, 0, "");
149 
150 /*
151  * AIO process info
152  */
153 #define AIOP_FREE	0x1			/* proc on free queue */
154 #define AIOP_SCHED	0x2			/* proc explicitly scheduled */
155 
156 struct aiothreadlist {
157 	int aiothreadflags;			/* AIO proc flags */
158 	TAILQ_ENTRY(aiothreadlist) list;	/* List of processes */
159 	struct thread *aiothread;		/* The AIO thread */
160 	TAILQ_HEAD (,aiocblist) jobtorun;	/* suggested job to run */
161 };
162 
163 /*
164  * data-structure for lio signal management
165  */
166 struct aio_liojob {
167 	int	lioj_flags;
168 	int	lioj_buffer_count;
169 	int	lioj_buffer_finished_count;
170 	int	lioj_queue_count;
171 	int	lioj_queue_finished_count;
172 	struct	sigevent lioj_signal;	/* signal on all I/O done */
173 	TAILQ_ENTRY	(aio_liojob) lioj_list;
174 	struct	kaioinfo *lioj_ki;
175 };
176 #define	LIOJ_SIGNAL		0x1	/* signal on all done (lio) */
177 #define	LIOJ_SIGNAL_POSTED	0x2	/* signal has been posted */
178 
179 /*
180  * per process aio data structure
181  */
182 struct kaioinfo {
183 	int	kaio_flags;		/* per process kaio flags */
184 	int	kaio_maxactive_count;	/* maximum number of AIOs */
185 	int	kaio_active_count;	/* number of currently used AIOs */
186 	int	kaio_qallowed_count;	/* maxiumu size of AIO queue */
187 	int	kaio_queue_count;	/* size of AIO queue */
188 	int	kaio_ballowed_count;	/* maximum number of buffers */
189 	int	kaio_queue_finished_count; /* number of daemon jobs finished */
190 	int	kaio_buffer_count;	/* number of physio buffers */
191 	int	kaio_buffer_finished_count; /* count of I/O done */
192 	struct 	proc *kaio_p;		/* process that uses this kaio block */
193 	TAILQ_HEAD (,aio_liojob) kaio_liojoblist; /* list of lio jobs */
194 	TAILQ_HEAD (,aiocblist)	kaio_jobqueue;	/* job queue for process */
195 	TAILQ_HEAD (,aiocblist)	kaio_jobdone;	/* done queue for process */
196 	TAILQ_HEAD (,aiocblist)	kaio_bufqueue;	/* buffer job queue for process */
197 	TAILQ_HEAD (,aiocblist)	kaio_bufdone;	/* buffer done queue for process */
198 	TAILQ_HEAD (,aiocblist) kaio_sockqueue; /* queue for aios waiting on sockets */
199 };
200 
201 #define KAIO_RUNDOWN	0x1	/* process is being run down */
202 #define KAIO_WAKEUP	0x2	/* wakeup process when there is a significant event */
203 
204 static TAILQ_HEAD(,aiothreadlist) aio_freeproc, aio_activeproc;
205 static TAILQ_HEAD(,aiocblist) aio_jobs;			/* Async job list */
206 static TAILQ_HEAD(,aiocblist) aio_bufjobs;		/* Phys I/O job list */
207 
208 static void	aio_init_aioinfo(struct proc *p);
209 static void	aio_onceonly(void *);
210 static int	aio_free_entry(struct aiocblist *aiocbe);
211 static void	aio_process(struct aiocblist *aiocbe);
212 static int	aio_newproc(void);
213 static int	aio_aqueue(struct thread *td, struct aiocb *job, int type);
214 static void	aio_physwakeup(struct buf *bp);
215 static int	aio_fphysio(struct proc *p, struct aiocblist *aiocbe);
216 static int	aio_qphysio(struct proc *p, struct aiocblist *iocb);
217 static void	aio_daemon(void *uproc);
218 static void	process_signal(void *aioj);
219 
220 SYSINIT(aio, SI_SUB_VFS, SI_ORDER_ANY, aio_onceonly, NULL);
221 
222 static vm_zone_t kaio_zone = 0, aiop_zone = 0, aiocb_zone = 0, aiol_zone = 0;
223 static vm_zone_t aiolio_zone = 0;
224 
225 /*
226  * Startup initialization
227  */
228 static void
229 aio_onceonly(void *na)
230 {
231 	TAILQ_INIT(&aio_freeproc);
232 	TAILQ_INIT(&aio_activeproc);
233 	TAILQ_INIT(&aio_jobs);
234 	TAILQ_INIT(&aio_bufjobs);
235 	kaio_zone = zinit("AIO", sizeof (struct kaioinfo), 0, 0, 1);
236 	aiop_zone = zinit("AIOP", sizeof (struct aiothreadlist), 0, 0, 1);
237 	aiocb_zone = zinit("AIOCB", sizeof (struct aiocblist), 0, 0, 1);
238 	aiol_zone = zinit("AIOL", AIO_LISTIO_MAX * sizeof (int), 0, 0, 1);
239 	aiolio_zone = zinit("AIOLIO", AIO_LISTIO_MAX * sizeof (struct
240 	    aio_liojob), 0, 0, 1);
241 	aiod_timeout = AIOD_TIMEOUT_DEFAULT;
242 	aiod_lifetime = AIOD_LIFETIME_DEFAULT;
243 	jobrefid = 1;
244 }
245 
246 /*
247  * Init the per-process aioinfo structure.  The aioinfo limits are set
248  * per-process for user limit (resource) management.
249  */
250 static void
251 aio_init_aioinfo(struct proc *p)
252 {
253 	struct kaioinfo *ki;
254 	if (p->p_aioinfo == NULL) {
255 		ki = zalloc(kaio_zone);
256 		p->p_aioinfo = ki;
257 		ki->kaio_flags = 0;
258 		ki->kaio_maxactive_count = max_aio_per_proc;
259 		ki->kaio_active_count = 0;
260 		ki->kaio_qallowed_count = max_aio_queue_per_proc;
261 		ki->kaio_queue_count = 0;
262 		ki->kaio_ballowed_count = max_buf_aio;
263 		ki->kaio_buffer_count = 0;
264 		ki->kaio_buffer_finished_count = 0;
265 		ki->kaio_p = p;
266 		TAILQ_INIT(&ki->kaio_jobdone);
267 		TAILQ_INIT(&ki->kaio_jobqueue);
268 		TAILQ_INIT(&ki->kaio_bufdone);
269 		TAILQ_INIT(&ki->kaio_bufqueue);
270 		TAILQ_INIT(&ki->kaio_liojoblist);
271 		TAILQ_INIT(&ki->kaio_sockqueue);
272 	}
273 
274 	while (num_aio_procs < target_aio_procs)
275 		aio_newproc();
276 }
277 
278 /*
279  * Free a job entry.  Wait for completion if it is currently active, but don't
280  * delay forever.  If we delay, we return a flag that says that we have to
281  * restart the queue scan.
282  */
283 static int
284 aio_free_entry(struct aiocblist *aiocbe)
285 {
286 	struct kaioinfo *ki;
287 	struct aiothreadlist *aiop;
288 	struct aio_liojob *lj;
289 	struct proc *p;
290 	int error;
291 	int s;
292 
293 	if (aiocbe->jobstate == JOBST_NULL)
294 		panic("aio_free_entry: freeing already free job");
295 
296 	p = aiocbe->userproc;
297 	ki = p->p_aioinfo;
298 	lj = aiocbe->lio;
299 	if (ki == NULL)
300 		panic("aio_free_entry: missing p->p_aioinfo");
301 
302 	while (aiocbe->jobstate == JOBST_JOBRUNNING) {
303 		if (aiocbe->jobflags & AIOCBLIST_ASYNCFREE)
304 			return 0;
305 		aiocbe->jobflags |= AIOCBLIST_RUNDOWN;
306 		tsleep(aiocbe, PRIBIO, "jobwai", 0);
307 	}
308 	aiocbe->jobflags &= ~AIOCBLIST_ASYNCFREE;
309 
310 	if (aiocbe->bp == NULL) {
311 		if (ki->kaio_queue_count <= 0)
312 			panic("aio_free_entry: process queue size <= 0");
313 		if (num_queue_count <= 0)
314 			panic("aio_free_entry: system wide queue size <= 0");
315 
316 		if (lj) {
317 			lj->lioj_queue_count--;
318 			if (aiocbe->jobflags & AIOCBLIST_DONE)
319 				lj->lioj_queue_finished_count--;
320 		}
321 		ki->kaio_queue_count--;
322 		if (aiocbe->jobflags & AIOCBLIST_DONE)
323 			ki->kaio_queue_finished_count--;
324 		num_queue_count--;
325 	} else {
326 		if (lj) {
327 			lj->lioj_buffer_count--;
328 			if (aiocbe->jobflags & AIOCBLIST_DONE)
329 				lj->lioj_buffer_finished_count--;
330 		}
331 		if (aiocbe->jobflags & AIOCBLIST_DONE)
332 			ki->kaio_buffer_finished_count--;
333 		ki->kaio_buffer_count--;
334 		num_buf_aio--;
335 	}
336 
337 	/* aiocbe is going away, we need to destroy any knotes */
338 	knote_remove(&p->p_thread, &aiocbe->klist); /* XXXKSE */
339 	/* XXXKSE Note the thread here is used to eventually find the
340 	 * owning process again, but it is also used to do a fo_close
341 	 * and that requires the thread. (but does it require the
342 	 * OWNING thread? (or maby the running thread?)
343 	 * There is a semantic problem here...
344 	 */
345 
346 	if ((ki->kaio_flags & KAIO_WAKEUP) || ((ki->kaio_flags & KAIO_RUNDOWN)
347 	    && ((ki->kaio_buffer_count == 0) && (ki->kaio_queue_count == 0)))) {
348 		ki->kaio_flags &= ~KAIO_WAKEUP;
349 		wakeup(p);
350 	}
351 
352 	if (aiocbe->jobstate == JOBST_JOBQBUF) {
353 		if ((error = aio_fphysio(p, aiocbe)) != 0)
354 			return error;
355 		if (aiocbe->jobstate != JOBST_JOBBFINISHED)
356 			panic("aio_free_entry: invalid physio finish-up state");
357 		s = splbio();
358 		TAILQ_REMOVE(&ki->kaio_bufdone, aiocbe, plist);
359 		splx(s);
360 	} else if (aiocbe->jobstate == JOBST_JOBQPROC) {
361 		aiop = aiocbe->jobaiothread;
362 		TAILQ_REMOVE(&aiop->jobtorun, aiocbe, list);
363 	} else if (aiocbe->jobstate == JOBST_JOBQGLOBAL) {
364 		TAILQ_REMOVE(&aio_jobs, aiocbe, list);
365 		TAILQ_REMOVE(&ki->kaio_jobqueue, aiocbe, plist);
366 	} else if (aiocbe->jobstate == JOBST_JOBFINISHED)
367 		TAILQ_REMOVE(&ki->kaio_jobdone, aiocbe, plist);
368 	else if (aiocbe->jobstate == JOBST_JOBBFINISHED) {
369 		s = splbio();
370 		TAILQ_REMOVE(&ki->kaio_bufdone, aiocbe, plist);
371 		splx(s);
372 		if (aiocbe->bp) {
373 			vunmapbuf(aiocbe->bp);
374 			relpbuf(aiocbe->bp, NULL);
375 			aiocbe->bp = NULL;
376 		}
377 	}
378 	if (lj && (lj->lioj_buffer_count == 0) && (lj->lioj_queue_count == 0)) {
379 		TAILQ_REMOVE(&ki->kaio_liojoblist, lj, lioj_list);
380 		zfree(aiolio_zone, lj);
381 	}
382 	aiocbe->jobstate = JOBST_NULL;
383 	untimeout(process_signal, aiocbe, aiocbe->timeouthandle);
384 	zfree(aiocb_zone, aiocbe);
385 	return 0;
386 }
387 #endif /* VFS_AIO */
388 
389 /*
390  * Rundown the jobs for a given process.
391  */
392 void
393 aio_proc_rundown(struct proc *p)
394 {
395 #ifndef VFS_AIO
396 	return;
397 #else
398 	int s;
399 	struct kaioinfo *ki;
400 	struct aio_liojob *lj, *ljn;
401 	struct aiocblist *aiocbe, *aiocbn;
402 	struct file *fp;
403 	struct filedesc *fdp;
404 	struct socket *so;
405 
406 	ki = p->p_aioinfo;
407 	if (ki == NULL)
408 		return;
409 
410 	ki->kaio_flags |= LIOJ_SIGNAL_POSTED;
411 	while ((ki->kaio_active_count > 0) || (ki->kaio_buffer_count >
412 	    ki->kaio_buffer_finished_count)) {
413 		ki->kaio_flags |= KAIO_RUNDOWN;
414 		if (tsleep(p, PRIBIO, "kaiowt", aiod_timeout))
415 			break;
416 	}
417 
418 	/*
419 	 * Move any aio ops that are waiting on socket I/O to the normal job
420 	 * queues so they are cleaned up with any others.
421 	 */
422 	fdp = p->p_fd;
423 
424 	s = splnet();
425 	for (aiocbe = TAILQ_FIRST(&ki->kaio_sockqueue); aiocbe; aiocbe =
426 	    aiocbn) {
427 		aiocbn = TAILQ_NEXT(aiocbe, plist);
428 		fp = fdp->fd_ofiles[aiocbe->uaiocb.aio_fildes];
429 
430 		/*
431 		 * Under some circumstances, the aio_fildes and the file
432 		 * structure don't match.  This would leave aiocbe's in the
433 		 * TAILQ associated with the socket and cause a panic later.
434 		 *
435 		 * Detect and fix.
436 		 */
437 		if ((fp == NULL) || (fp != aiocbe->fd_file))
438 			fp = aiocbe->fd_file;
439 		if (fp) {
440 			so = (struct socket *)fp->f_data;
441 			TAILQ_REMOVE(&so->so_aiojobq, aiocbe, list);
442 			if (TAILQ_EMPTY(&so->so_aiojobq)) {
443 				so->so_snd.sb_flags &= ~SB_AIO;
444 				so->so_rcv.sb_flags &= ~SB_AIO;
445 			}
446 		}
447 		TAILQ_REMOVE(&ki->kaio_sockqueue, aiocbe, plist);
448 		TAILQ_INSERT_HEAD(&aio_jobs, aiocbe, list);
449 		TAILQ_INSERT_HEAD(&ki->kaio_jobqueue, aiocbe, plist);
450 	}
451 	splx(s);
452 
453 restart1:
454 	for (aiocbe = TAILQ_FIRST(&ki->kaio_jobdone); aiocbe; aiocbe = aiocbn) {
455 		aiocbn = TAILQ_NEXT(aiocbe, plist);
456 		if (aio_free_entry(aiocbe))
457 			goto restart1;
458 	}
459 
460 restart2:
461 	for (aiocbe = TAILQ_FIRST(&ki->kaio_jobqueue); aiocbe; aiocbe =
462 	    aiocbn) {
463 		aiocbn = TAILQ_NEXT(aiocbe, plist);
464 		if (aio_free_entry(aiocbe))
465 			goto restart2;
466 	}
467 
468 /*
469  * Note the use of lots of splbio here, trying to avoid splbio for long chains
470  * of I/O.  Probably unnecessary.
471  */
472 restart3:
473 	s = splbio();
474 	while (TAILQ_FIRST(&ki->kaio_bufqueue)) {
475 		ki->kaio_flags |= KAIO_WAKEUP;
476 		tsleep(p, PRIBIO, "aioprn", 0);
477 		splx(s);
478 		goto restart3;
479 	}
480 	splx(s);
481 
482 restart4:
483 	s = splbio();
484 	for (aiocbe = TAILQ_FIRST(&ki->kaio_bufdone); aiocbe; aiocbe = aiocbn) {
485 		aiocbn = TAILQ_NEXT(aiocbe, plist);
486 		if (aio_free_entry(aiocbe)) {
487 			splx(s);
488 			goto restart4;
489 		}
490 	}
491 	splx(s);
492 
493         /*
494          * If we've slept, jobs might have moved from one queue to another.
495          * Retry rundown if we didn't manage to empty the queues.
496          */
497         if (TAILQ_FIRST(&ki->kaio_jobdone) != NULL ||
498 	    TAILQ_FIRST(&ki->kaio_jobqueue) != NULL ||
499 	    TAILQ_FIRST(&ki->kaio_bufqueue) != NULL ||
500 	    TAILQ_FIRST(&ki->kaio_bufdone) != NULL)
501 		goto restart1;
502 
503 	for (lj = TAILQ_FIRST(&ki->kaio_liojoblist); lj; lj = ljn) {
504 		ljn = TAILQ_NEXT(lj, lioj_list);
505 		if ((lj->lioj_buffer_count == 0) && (lj->lioj_queue_count ==
506 		    0)) {
507 			TAILQ_REMOVE(&ki->kaio_liojoblist, lj, lioj_list);
508 			zfree(aiolio_zone, lj);
509 		} else {
510 #ifdef DIAGNOSTIC
511 			printf("LIO job not cleaned up: B:%d, BF:%d, Q:%d, "
512 			    "QF:%d\n", lj->lioj_buffer_count,
513 			    lj->lioj_buffer_finished_count,
514 			    lj->lioj_queue_count,
515 			    lj->lioj_queue_finished_count);
516 #endif
517 		}
518 	}
519 
520 	zfree(kaio_zone, ki);
521 	p->p_aioinfo = NULL;
522 #endif /* VFS_AIO */
523 }
524 
525 #ifdef VFS_AIO
526 /*
527  * Select a job to run (called by an AIO daemon).
528  */
529 static struct aiocblist *
530 aio_selectjob(struct aiothreadlist *aiop)
531 {
532 	int s;
533 	struct aiocblist *aiocbe;
534 	struct kaioinfo *ki;
535 	struct proc *userp;
536 
537 	aiocbe = TAILQ_FIRST(&aiop->jobtorun);
538 	if (aiocbe) {
539 		TAILQ_REMOVE(&aiop->jobtorun, aiocbe, list);
540 		return aiocbe;
541 	}
542 
543 	s = splnet();
544 	for (aiocbe = TAILQ_FIRST(&aio_jobs); aiocbe; aiocbe =
545 	    TAILQ_NEXT(aiocbe, list)) {
546 		userp = aiocbe->userproc;
547 		ki = userp->p_aioinfo;
548 
549 		if (ki->kaio_active_count < ki->kaio_maxactive_count) {
550 			TAILQ_REMOVE(&aio_jobs, aiocbe, list);
551 			splx(s);
552 			return aiocbe;
553 		}
554 	}
555 	splx(s);
556 
557 	return NULL;
558 }
559 
560 /*
561  * The AIO processing activity.  This is the code that does the I/O request for
562  * the non-physio version of the operations.  The normal vn operations are used,
563  * and this code should work in all instances for every type of file, including
564  * pipes, sockets, fifos, and regular files.
565  */
566 static void
567 aio_process(struct aiocblist *aiocbe)
568 {
569 	struct filedesc *fdp;
570 	struct thread *td;
571 	struct proc *userp;
572 	struct proc *mycp;
573 	struct aiocb *cb;
574 	struct file *fp;
575 	struct uio auio;
576 	struct iovec aiov;
577 	unsigned int fd;
578 	int cnt;
579 	int error;
580 	off_t offset;
581 	int oublock_st, oublock_end;
582 	int inblock_st, inblock_end;
583 
584 	userp = aiocbe->userproc;
585 	td = curthread;
586 	mycp = td->td_proc;
587 	cb = &aiocbe->uaiocb;
588 
589 	fdp = mycp->p_fd;
590 	fd = cb->aio_fildes;
591 	fp = fdp->fd_ofiles[fd];
592 
593 	if ((fp == NULL) || (fp != aiocbe->fd_file)) {
594 		cb->_aiocb_private.error = EBADF;
595 		cb->_aiocb_private.status = -1;
596 		return;
597 	}
598 
599 	aiov.iov_base = cb->aio_buf;
600 	aiov.iov_len = cb->aio_nbytes;
601 
602 	auio.uio_iov = &aiov;
603 	auio.uio_iovcnt = 1;
604 	auio.uio_offset = offset = cb->aio_offset;
605 	auio.uio_resid = cb->aio_nbytes;
606 	cnt = cb->aio_nbytes;
607 	auio.uio_segflg = UIO_USERSPACE;
608 	auio.uio_td = td;
609 
610 	inblock_st = mycp->p_stats->p_ru.ru_inblock;
611 	oublock_st = mycp->p_stats->p_ru.ru_oublock;
612 	/*
613 	 * Temporarily bump the ref count while reading to avoid the
614 	 * descriptor being ripped out from under us.
615 	 */
616 	fhold(fp);
617 	if (cb->aio_lio_opcode == LIO_READ) {
618 		auio.uio_rw = UIO_READ;
619 		error = fo_read(fp, &auio, fp->f_cred, FOF_OFFSET, td);
620 	} else {
621 		auio.uio_rw = UIO_WRITE;
622 		error = fo_write(fp, &auio, fp->f_cred, FOF_OFFSET, td);
623 	}
624 	fdrop(fp, td);
625 	inblock_end = mycp->p_stats->p_ru.ru_inblock;
626 	oublock_end = mycp->p_stats->p_ru.ru_oublock;
627 
628 	aiocbe->inputcharge = inblock_end - inblock_st;
629 	aiocbe->outputcharge = oublock_end - oublock_st;
630 
631 	if ((error) && (auio.uio_resid != cnt)) {
632 		if (error == ERESTART || error == EINTR || error == EWOULDBLOCK)
633 			error = 0;
634 		if ((error == EPIPE) && (cb->aio_lio_opcode == LIO_WRITE)) {
635 			PROC_LOCK(userp);
636 			psignal(userp, SIGPIPE);
637 			PROC_UNLOCK(userp);
638 		}
639 	}
640 
641 	cnt -= auio.uio_resid;
642 	cb->_aiocb_private.error = error;
643 	cb->_aiocb_private.status = cnt;
644 }
645 
646 /*
647  * The AIO daemon, most of the actual work is done in aio_process,
648  * but the setup (and address space mgmt) is done in this routine.
649  */
650 static void
651 aio_daemon(void *uproc)
652 {
653 	int s;
654 	struct aio_liojob *lj;
655 	struct aiocb *cb;
656 	struct aiocblist *aiocbe;
657 	struct aiothreadlist *aiop;
658 	struct kaioinfo *ki;
659 	struct proc *curcp, *mycp, *userp;
660 	struct vmspace *myvm, *tmpvm;
661 	struct thread *td = curthread;
662 
663 	mtx_lock(&Giant);
664 	/*
665 	 * Local copies of curproc (cp) and vmspace (myvm)
666 	 */
667 	mycp = td->td_proc;
668 	myvm = mycp->p_vmspace;
669 
670 	if (mycp->p_textvp) {
671 		vrele(mycp->p_textvp);
672 		mycp->p_textvp = NULL;
673 	}
674 
675 	/*
676 	 * Allocate and ready the aio control info.  There is one aiop structure
677 	 * per daemon.
678 	 */
679 	aiop = zalloc(aiop_zone);
680 	aiop->aiothread = td;
681 	aiop->aiothreadflags |= AIOP_FREE;
682 	TAILQ_INIT(&aiop->jobtorun);
683 
684 	s = splnet();
685 
686 	/*
687 	 * Place thread (lightweight process) onto the AIO free thread list.
688 	 */
689 	if (TAILQ_EMPTY(&aio_freeproc))
690 		wakeup(&aio_freeproc);
691 	TAILQ_INSERT_HEAD(&aio_freeproc, aiop, list);
692 
693 	splx(s);
694 
695 	/*
696 	 * Get rid of our current filedescriptors.  AIOD's don't need any
697 	 * filedescriptors, except as temporarily inherited from the client.
698 	 */
699 	fdfree(td);
700 	mycp->p_fd = NULL;
701 
702 	/* The daemon resides in its own pgrp. */
703 	enterpgrp(mycp, mycp->p_pid, 1);
704 
705 	/* Mark special process type. */
706 	mycp->p_flag |= P_SYSTEM;
707 
708 	/*
709 	 * Wakeup parent process.  (Parent sleeps to keep from blasting away
710 	 * and creating too many daemons.)
711 	 */
712 	wakeup(mycp);
713 
714 	for (;;) {
715 		/*
716 		 * curcp is the current daemon process context.
717 		 * userp is the current user process context.
718 		 */
719 		curcp = mycp;
720 
721 		/*
722 		 * Take daemon off of free queue
723 		 */
724 		if (aiop->aiothreadflags & AIOP_FREE) {
725 			s = splnet();
726 			TAILQ_REMOVE(&aio_freeproc, aiop, list);
727 			TAILQ_INSERT_TAIL(&aio_activeproc, aiop, list);
728 			aiop->aiothreadflags &= ~AIOP_FREE;
729 			splx(s);
730 		}
731 		aiop->aiothreadflags &= ~AIOP_SCHED;
732 
733 		/*
734 		 * Check for jobs.
735 		 */
736 		while ((aiocbe = aio_selectjob(aiop)) != NULL) {
737 			cb = &aiocbe->uaiocb;
738 			userp = aiocbe->userproc;
739 
740 			aiocbe->jobstate = JOBST_JOBRUNNING;
741 
742 			/*
743 			 * Connect to process address space for user program.
744 			 */
745 			if (userp != curcp) {
746 				/*
747 				 * Save the current address space that we are
748 				 * connected to.
749 				 */
750 				tmpvm = mycp->p_vmspace;
751 
752 				/*
753 				 * Point to the new user address space, and
754 				 * refer to it.
755 				 */
756 				mycp->p_vmspace = userp->p_vmspace;
757 				mycp->p_vmspace->vm_refcnt++;
758 
759 				/* Activate the new mapping. */
760 				pmap_activate(&mycp->p_thread);
761 
762 				/*
763 				 * If the old address space wasn't the daemons
764 				 * own address space, then we need to remove the
765 				 * daemon's reference from the other process
766 				 * that it was acting on behalf of.
767 				 */
768 				if (tmpvm != myvm) {
769 					vmspace_free(tmpvm);
770 				}
771 
772 				/*
773 				 * Disassociate from previous clients file
774 				 * descriptors, and associate to the new clients
775 				 * descriptors.  Note that the daemon doesn't
776 				 * need to worry about its orginal descriptors,
777 				 * because they were originally freed.
778 				 */
779 				if (mycp->p_fd)
780 					fdfree(td);
781 				mycp->p_fd = fdshare(userp);
782 				curcp = userp;
783 			}
784 
785 			ki = userp->p_aioinfo;
786 			lj = aiocbe->lio;
787 
788 			/* Account for currently active jobs. */
789 			ki->kaio_active_count++;
790 
791 			/* Do the I/O function. */
792 			aiocbe->jobaiothread = aiop;
793 			aio_process(aiocbe);
794 
795 			/* Decrement the active job count. */
796 			ki->kaio_active_count--;
797 
798 			/*
799 			 * Increment the completion count for wakeup/signal
800 			 * comparisons.
801 			 */
802 			aiocbe->jobflags |= AIOCBLIST_DONE;
803 			ki->kaio_queue_finished_count++;
804 			if (lj)
805 				lj->lioj_queue_finished_count++;
806 			if ((ki->kaio_flags & KAIO_WAKEUP) || ((ki->kaio_flags
807 			    & KAIO_RUNDOWN) && (ki->kaio_active_count == 0))) {
808 				ki->kaio_flags &= ~KAIO_WAKEUP;
809 				wakeup(userp);
810 			}
811 
812 			s = splbio();
813 			if (lj && (lj->lioj_flags &
814 			    (LIOJ_SIGNAL|LIOJ_SIGNAL_POSTED)) == LIOJ_SIGNAL) {
815 				if ((lj->lioj_queue_finished_count ==
816 				    lj->lioj_queue_count) &&
817 				    (lj->lioj_buffer_finished_count ==
818 				    lj->lioj_buffer_count)) {
819 					PROC_LOCK(userp);
820 					psignal(userp,
821 					    lj->lioj_signal.sigev_signo);
822 					PROC_UNLOCK(userp);
823 					lj->lioj_flags |= LIOJ_SIGNAL_POSTED;
824 				}
825 			}
826 			splx(s);
827 
828 			aiocbe->jobstate = JOBST_JOBFINISHED;
829 
830 			/*
831 			 * If the I/O request should be automatically rundown,
832 			 * do the needed cleanup.  Otherwise, place the queue
833 			 * entry for the just finished I/O request into the done
834 			 * queue for the associated client.
835 			 */
836 			s = splnet();
837 			if (aiocbe->jobflags & AIOCBLIST_ASYNCFREE) {
838 				aiocbe->jobflags &= ~AIOCBLIST_ASYNCFREE;
839 				zfree(aiocb_zone, aiocbe);
840 			} else {
841 				TAILQ_REMOVE(&ki->kaio_jobqueue, aiocbe, plist);
842 				TAILQ_INSERT_TAIL(&ki->kaio_jobdone, aiocbe,
843 				    plist);
844 			}
845 			splx(s);
846 			KNOTE(&aiocbe->klist, 0);
847 
848 			if (aiocbe->jobflags & AIOCBLIST_RUNDOWN) {
849 				wakeup(aiocbe);
850 				aiocbe->jobflags &= ~AIOCBLIST_RUNDOWN;
851 			}
852 
853 			if (cb->aio_sigevent.sigev_notify == SIGEV_SIGNAL) {
854 				PROC_LOCK(userp);
855 				psignal(userp, cb->aio_sigevent.sigev_signo);
856 				PROC_UNLOCK(userp);
857 			}
858 		}
859 
860 		/*
861 		 * Disconnect from user address space.
862 		 */
863 		if (curcp != mycp) {
864 			/* Get the user address space to disconnect from. */
865 			tmpvm = mycp->p_vmspace;
866 
867 			/* Get original address space for daemon. */
868 			mycp->p_vmspace = myvm;
869 
870 			/* Activate the daemon's address space. */
871 			pmap_activate(&mycp->p_thread);
872 #ifdef DIAGNOSTIC
873 			if (tmpvm == myvm) {
874 				printf("AIOD: vmspace problem -- %d\n",
875 				    mycp->p_pid);
876 			}
877 #endif
878 			/* Remove our vmspace reference. */
879 			vmspace_free(tmpvm);
880 
881 			/*
882 			 * Disassociate from the user process's file
883 			 * descriptors.
884 			 */
885 			if (mycp->p_fd)
886 				fdfree(td);
887 			mycp->p_fd = NULL;
888 			curcp = mycp;
889 		}
890 
891 		/*
892 		 * If we are the first to be put onto the free queue, wakeup
893 		 * anyone waiting for a daemon.
894 		 */
895 		s = splnet();
896 		TAILQ_REMOVE(&aio_activeproc, aiop, list);
897 		if (TAILQ_EMPTY(&aio_freeproc))
898 			wakeup(&aio_freeproc);
899 		TAILQ_INSERT_HEAD(&aio_freeproc, aiop, list);
900 		aiop->aiothreadflags |= AIOP_FREE;
901 		splx(s);
902 
903 		/*
904 		 * If daemon is inactive for a long time, allow it to exit,
905 		 * thereby freeing resources.
906 		 */
907 		if (((aiop->aiothreadflags & AIOP_SCHED) == 0) && tsleep(mycp,
908 		    PRIBIO, "aiordy", aiod_lifetime)) {
909 			s = splnet();
910 			if ((TAILQ_FIRST(&aio_jobs) == NULL) &&
911 			    (TAILQ_FIRST(&aiop->jobtorun) == NULL)) {
912 				if ((aiop->aiothreadflags & AIOP_FREE) &&
913 				    (num_aio_procs > target_aio_procs)) {
914 					TAILQ_REMOVE(&aio_freeproc, aiop, list);
915 					splx(s);
916 					zfree(aiop_zone, aiop);
917 					num_aio_procs--;
918 #ifdef DIAGNOSTIC
919 					if (mycp->p_vmspace->vm_refcnt <= 1) {
920 						printf("AIOD: bad vm refcnt for"
921 						    " exiting daemon: %d\n",
922 						    mycp->p_vmspace->vm_refcnt);
923 					}
924 #endif
925 					kthread_exit(0);
926 				}
927 			}
928 			splx(s);
929 		}
930 	}
931 }
932 
933 /*
934  * Create a new AIO daemon.  This is mostly a kernel-thread fork routine.  The
935  * AIO daemon modifies its environment itself.
936  */
937 static int
938 aio_newproc()
939 {
940 	int error;
941 	struct proc *p;
942 
943 	error = kthread_create(aio_daemon, curproc, &p, RFNOWAIT, "aiod%d",
944 			       num_aio_procs);
945 	if (error)
946 		return error;
947 
948 	/*
949 	 * Wait until daemon is started, but continue on just in case to
950 	 * handle error conditions.
951 	 */
952 	error = tsleep(p, PZERO, "aiosta", aiod_timeout);
953 
954 	num_aio_procs++;
955 
956 	return error;
957 }
958 
959 /*
960  * Try the high-performance, low-overhead physio method for eligible
961  * VCHR devices.  This method doesn't use an aio helper thread, and
962  * thus has very low overhead.
963  *
964  * Assumes that the caller, _aio_aqueue(), has incremented the file
965  * structure's reference count, preventing its deallocation for the
966  * duration of this call.
967  */
968 static int
969 aio_qphysio(struct proc *p, struct aiocblist *aiocbe)
970 {
971 	int error;
972 	struct aiocb *cb;
973 	struct file *fp;
974 	struct buf *bp;
975 	struct vnode *vp;
976 	struct kaioinfo *ki;
977 	struct filedesc *fdp;
978 	struct aio_liojob *lj;
979 	int fd;
980 	int s;
981 	int notify;
982 
983 	cb = &aiocbe->uaiocb;
984 	fdp = p->p_fd;
985 	fd = cb->aio_fildes;
986 	fp = fdp->fd_ofiles[fd];
987 
988 	if (fp->f_type != DTYPE_VNODE)
989 		return (-1);
990 
991 	vp = (struct vnode *)fp->f_data;
992 
993 	/*
994 	 * If its not a disk, we don't want to return a positive error.
995 	 * It causes the aio code to not fall through to try the thread
996 	 * way when you're talking to a regular file.
997 	 */
998 	if (!vn_isdisk(vp, &error)) {
999 		if (error == ENOTBLK)
1000 			return (-1);
1001 		else
1002 			return (error);
1003 	}
1004 
1005  	if (cb->aio_nbytes % vp->v_rdev->si_bsize_phys)
1006 		return (-1);
1007 
1008 	if (cb->aio_nbytes >
1009 	    MAXPHYS - (((vm_offset_t) cb->aio_buf) & PAGE_MASK))
1010 		return (-1);
1011 
1012 	ki = p->p_aioinfo;
1013 	if (ki->kaio_buffer_count >= ki->kaio_ballowed_count)
1014 		return (-1);
1015 
1016 	ki->kaio_buffer_count++;
1017 
1018 	lj = aiocbe->lio;
1019 	if (lj)
1020 		lj->lioj_buffer_count++;
1021 
1022 	/* Create and build a buffer header for a transfer. */
1023 	bp = (struct buf *)getpbuf(NULL);
1024 	BUF_KERNPROC(bp);
1025 
1026 	/*
1027 	 * Get a copy of the kva from the physical buffer.
1028 	 */
1029 	bp->b_caller1 = p;
1030 	bp->b_dev = vp->v_rdev;
1031 	error = bp->b_error = 0;
1032 
1033 	bp->b_bcount = cb->aio_nbytes;
1034 	bp->b_bufsize = cb->aio_nbytes;
1035 	bp->b_flags = B_PHYS;
1036 	bp->b_iodone = aio_physwakeup;
1037 	bp->b_saveaddr = bp->b_data;
1038 	bp->b_data = cb->aio_buf;
1039 	bp->b_blkno = btodb(cb->aio_offset);
1040 
1041 	if (cb->aio_lio_opcode == LIO_WRITE) {
1042 		bp->b_iocmd = BIO_WRITE;
1043 		if (!useracc(bp->b_data, bp->b_bufsize, VM_PROT_READ)) {
1044 			error = EFAULT;
1045 			goto doerror;
1046 		}
1047 	} else {
1048 		bp->b_iocmd = BIO_READ;
1049 		if (!useracc(bp->b_data, bp->b_bufsize, VM_PROT_WRITE)) {
1050 			error = EFAULT;
1051 			goto doerror;
1052 		}
1053 	}
1054 
1055 	/* Bring buffer into kernel space. */
1056 	vmapbuf(bp);
1057 
1058 	s = splbio();
1059 	aiocbe->bp = bp;
1060 	bp->b_spc = (void *)aiocbe;
1061 	TAILQ_INSERT_TAIL(&aio_bufjobs, aiocbe, list);
1062 	TAILQ_INSERT_TAIL(&ki->kaio_bufqueue, aiocbe, plist);
1063 	aiocbe->jobstate = JOBST_JOBQBUF;
1064 	cb->_aiocb_private.status = cb->aio_nbytes;
1065 	num_buf_aio++;
1066 	bp->b_error = 0;
1067 
1068 	splx(s);
1069 
1070 	/* Perform transfer. */
1071 	DEV_STRATEGY(bp, 0);
1072 
1073 	notify = 0;
1074 	s = splbio();
1075 
1076 	/*
1077 	 * If we had an error invoking the request, or an error in processing
1078 	 * the request before we have returned, we process it as an error in
1079 	 * transfer.  Note that such an I/O error is not indicated immediately,
1080 	 * but is returned using the aio_error mechanism.  In this case,
1081 	 * aio_suspend will return immediately.
1082 	 */
1083 	if (bp->b_error || (bp->b_ioflags & BIO_ERROR)) {
1084 		struct aiocb *job = aiocbe->uuaiocb;
1085 
1086 		aiocbe->uaiocb._aiocb_private.status = 0;
1087 		suword(&job->_aiocb_private.status, 0);
1088 		aiocbe->uaiocb._aiocb_private.error = bp->b_error;
1089 		suword(&job->_aiocb_private.error, bp->b_error);
1090 
1091 		ki->kaio_buffer_finished_count++;
1092 
1093 		if (aiocbe->jobstate != JOBST_JOBBFINISHED) {
1094 			aiocbe->jobstate = JOBST_JOBBFINISHED;
1095 			aiocbe->jobflags |= AIOCBLIST_DONE;
1096 			TAILQ_REMOVE(&aio_bufjobs, aiocbe, list);
1097 			TAILQ_REMOVE(&ki->kaio_bufqueue, aiocbe, plist);
1098 			TAILQ_INSERT_TAIL(&ki->kaio_bufdone, aiocbe, plist);
1099 			notify = 1;
1100 		}
1101 	}
1102 	splx(s);
1103 	if (notify)
1104 		KNOTE(&aiocbe->klist, 0);
1105 	return 0;
1106 
1107 doerror:
1108 	ki->kaio_buffer_count--;
1109 	if (lj)
1110 		lj->lioj_buffer_count--;
1111 	aiocbe->bp = NULL;
1112 	relpbuf(bp, NULL);
1113 	return error;
1114 }
1115 
1116 /*
1117  * This waits/tests physio completion.
1118  */
1119 static int
1120 aio_fphysio(struct proc *p, struct aiocblist *iocb)
1121 {
1122 	int s;
1123 	struct buf *bp;
1124 	int error;
1125 
1126 	bp = iocb->bp;
1127 
1128 	s = splbio();
1129 	while ((bp->b_flags & B_DONE) == 0) {
1130 		if (tsleep(bp, PRIBIO, "physstr", aiod_timeout)) {
1131 			if ((bp->b_flags & B_DONE) == 0) {
1132 				splx(s);
1133 				return EINPROGRESS;
1134 			} else
1135 				break;
1136 		}
1137 	}
1138 	splx(s);
1139 
1140 	/* Release mapping into kernel space. */
1141 	vunmapbuf(bp);
1142 	iocb->bp = 0;
1143 
1144 	error = 0;
1145 
1146 	/* Check for an error. */
1147 	if (bp->b_ioflags & BIO_ERROR)
1148 		error = bp->b_error;
1149 
1150 	relpbuf(bp, NULL);
1151 	return (error);
1152 }
1153 #endif /* VFS_AIO */
1154 
1155 /*
1156  * Wake up aio requests that may be serviceable now.
1157  */
1158 void
1159 aio_swake(struct socket *so, struct sockbuf *sb)
1160 {
1161 #ifndef VFS_AIO
1162 	return;
1163 #else
1164 	struct aiocblist *cb,*cbn;
1165 	struct proc *p;
1166 	struct kaioinfo *ki = NULL;
1167 	int opcode, wakecount = 0;
1168 	struct aiothreadlist *aiop;
1169 
1170 	if (sb == &so->so_snd) {
1171 		opcode = LIO_WRITE;
1172 		so->so_snd.sb_flags &= ~SB_AIO;
1173 	} else {
1174 		opcode = LIO_READ;
1175 		so->so_rcv.sb_flags &= ~SB_AIO;
1176 	}
1177 
1178 	for (cb = TAILQ_FIRST(&so->so_aiojobq); cb; cb = cbn) {
1179 		cbn = TAILQ_NEXT(cb, list);
1180 		if (opcode == cb->uaiocb.aio_lio_opcode) {
1181 			p = cb->userproc;
1182 			ki = p->p_aioinfo;
1183 			TAILQ_REMOVE(&so->so_aiojobq, cb, list);
1184 			TAILQ_REMOVE(&ki->kaio_sockqueue, cb, plist);
1185 			TAILQ_INSERT_TAIL(&aio_jobs, cb, list);
1186 			TAILQ_INSERT_TAIL(&ki->kaio_jobqueue, cb, plist);
1187 			wakecount++;
1188 			if (cb->jobstate != JOBST_JOBQGLOBAL)
1189 				panic("invalid queue value");
1190 		}
1191 	}
1192 
1193 	while (wakecount--) {
1194 		if ((aiop = TAILQ_FIRST(&aio_freeproc)) != 0) {
1195 			TAILQ_REMOVE(&aio_freeproc, aiop, list);
1196 			TAILQ_INSERT_TAIL(&aio_activeproc, aiop, list);
1197 			aiop->aiothreadflags &= ~AIOP_FREE;
1198 			wakeup(aiop->aiothread);
1199 		}
1200 	}
1201 #endif /* VFS_AIO */
1202 }
1203 
1204 #ifdef VFS_AIO
1205 /*
1206  * Queue a new AIO request.  Choosing either the threaded or direct physio VCHR
1207  * technique is done in this code.
1208  */
1209 static int
1210 _aio_aqueue(struct thread *td, struct aiocb *job, struct aio_liojob *lj, int type)
1211 {
1212 	struct proc *p = td->td_proc;
1213 	struct filedesc *fdp;
1214 	struct file *fp;
1215 	unsigned int fd;
1216 	struct socket *so;
1217 	int s;
1218 	int error;
1219 	int opcode;
1220 	struct aiocblist *aiocbe;
1221 	struct aiothreadlist *aiop;
1222 	struct kaioinfo *ki;
1223 	struct kevent kev;
1224 	struct kqueue *kq;
1225 	struct file *kq_fp;
1226 
1227 	aiocbe = zalloc(aiocb_zone);
1228 	aiocbe->inputcharge = 0;
1229 	aiocbe->outputcharge = 0;
1230 	callout_handle_init(&aiocbe->timeouthandle);
1231 	SLIST_INIT(&aiocbe->klist);
1232 
1233 	suword(&job->_aiocb_private.status, -1);
1234 	suword(&job->_aiocb_private.error, 0);
1235 	suword(&job->_aiocb_private.kernelinfo, -1);
1236 
1237 	error = copyin(job, &aiocbe->uaiocb, sizeof(aiocbe->uaiocb));
1238 	if (error) {
1239 		suword(&job->_aiocb_private.error, error);
1240 		zfree(aiocb_zone, aiocbe);
1241 		return error;
1242 	}
1243 	if (aiocbe->uaiocb.aio_sigevent.sigev_notify == SIGEV_SIGNAL &&
1244 		!_SIG_VALID(aiocbe->uaiocb.aio_sigevent.sigev_signo)) {
1245 		zfree(aiocb_zone, aiocbe);
1246 		return EINVAL;
1247 	}
1248 
1249 	/* Save userspace address of the job info. */
1250 	aiocbe->uuaiocb = job;
1251 
1252 	/* Get the opcode. */
1253 	if (type != LIO_NOP)
1254 		aiocbe->uaiocb.aio_lio_opcode = type;
1255 	opcode = aiocbe->uaiocb.aio_lio_opcode;
1256 
1257 	/* Get the fd info for process. */
1258 	fdp = p->p_fd;
1259 
1260 	/*
1261 	 * Range check file descriptor.
1262 	 */
1263 	fd = aiocbe->uaiocb.aio_fildes;
1264 	if (fd >= fdp->fd_nfiles) {
1265 		zfree(aiocb_zone, aiocbe);
1266 		if (type == 0)
1267 			suword(&job->_aiocb_private.error, EBADF);
1268 		return EBADF;
1269 	}
1270 
1271 	fp = aiocbe->fd_file = fdp->fd_ofiles[fd];
1272 	if ((fp == NULL) || ((opcode == LIO_WRITE) && ((fp->f_flag & FWRITE) ==
1273 	    0))) {
1274 		zfree(aiocb_zone, aiocbe);
1275 		if (type == 0)
1276 			suword(&job->_aiocb_private.error, EBADF);
1277 		return EBADF;
1278 	}
1279 
1280 	if (aiocbe->uaiocb.aio_offset == -1LL) {
1281 		zfree(aiocb_zone, aiocbe);
1282 		if (type == 0)
1283 			suword(&job->_aiocb_private.error, EINVAL);
1284 		return EINVAL;
1285 	}
1286 
1287 	error = suword(&job->_aiocb_private.kernelinfo, jobrefid);
1288 	if (error) {
1289 		zfree(aiocb_zone, aiocbe);
1290 		if (type == 0)
1291 			suword(&job->_aiocb_private.error, EINVAL);
1292 		return error;
1293 	}
1294 
1295 	aiocbe->uaiocb._aiocb_private.kernelinfo = (void *)(intptr_t)jobrefid;
1296 	if (jobrefid == LONG_MAX)
1297 		jobrefid = 1;
1298 	else
1299 		jobrefid++;
1300 
1301 	if (opcode == LIO_NOP) {
1302 		zfree(aiocb_zone, aiocbe);
1303 		if (type == 0) {
1304 			suword(&job->_aiocb_private.error, 0);
1305 			suword(&job->_aiocb_private.status, 0);
1306 			suword(&job->_aiocb_private.kernelinfo, 0);
1307 		}
1308 		return 0;
1309 	}
1310 
1311 	if ((opcode != LIO_READ) && (opcode != LIO_WRITE)) {
1312 		zfree(aiocb_zone, aiocbe);
1313 		if (type == 0) {
1314 			suword(&job->_aiocb_private.status, 0);
1315 			suword(&job->_aiocb_private.error, EINVAL);
1316 		}
1317 		return EINVAL;
1318 	}
1319 
1320 	fhold(fp);
1321 
1322 	if (aiocbe->uaiocb.aio_sigevent.sigev_notify == SIGEV_KEVENT) {
1323 		kev.ident = aiocbe->uaiocb.aio_sigevent.sigev_notify_kqueue;
1324 		kev.udata = aiocbe->uaiocb.aio_sigevent.sigev_value.sigval_ptr;
1325 	}
1326 	else {
1327 		/*
1328 		 * This method for requesting kevent-based notification won't
1329 		 * work on the alpha, since we're passing in a pointer
1330 		 * via aio_lio_opcode, which is an int.  Use the SIGEV_KEVENT-
1331 		 * based method instead.
1332 		 */
1333 		struct kevent *kevp;
1334 
1335 		kevp = (struct kevent *)job->aio_lio_opcode;
1336 		if (kevp == NULL)
1337 			goto no_kqueue;
1338 
1339 		error = copyin(kevp, &kev, sizeof(kev));
1340 		if (error)
1341 			goto aqueue_fail;
1342 	}
1343 	if ((u_int)kev.ident >= fdp->fd_nfiles ||
1344 	    (kq_fp = fdp->fd_ofiles[kev.ident]) == NULL ||
1345 	    (kq_fp->f_type != DTYPE_KQUEUE)) {
1346 		error = EBADF;
1347 		goto aqueue_fail;
1348 	}
1349 	kq = (struct kqueue *)kq_fp->f_data;
1350 	kev.ident = (uintptr_t)aiocbe;
1351 	kev.filter = EVFILT_AIO;
1352 	kev.flags = EV_ADD | EV_ENABLE | EV_FLAG1;
1353 	error = kqueue_register(kq, &kev, td);
1354 aqueue_fail:
1355 	if (error) {
1356 		zfree(aiocb_zone, aiocbe);
1357 		if (type == 0)
1358 			suword(&job->_aiocb_private.error, error);
1359 		goto done;
1360 	}
1361 no_kqueue:
1362 
1363 	suword(&job->_aiocb_private.error, EINPROGRESS);
1364 	aiocbe->uaiocb._aiocb_private.error = EINPROGRESS;
1365 	aiocbe->userproc = p;
1366 	aiocbe->jobflags = 0;
1367 	aiocbe->lio = lj;
1368 	ki = p->p_aioinfo;
1369 
1370 	if (fp->f_type == DTYPE_SOCKET) {
1371 		/*
1372 		 * Alternate queueing for socket ops: Reach down into the
1373 		 * descriptor to get the socket data.  Then check to see if the
1374 		 * socket is ready to be read or written (based on the requested
1375 		 * operation).
1376 		 *
1377 		 * If it is not ready for io, then queue the aiocbe on the
1378 		 * socket, and set the flags so we get a call when sbnotify()
1379 		 * happens.
1380 		 */
1381 		so = (struct socket *)fp->f_data;
1382 		s = splnet();
1383 		if (((opcode == LIO_READ) && (!soreadable(so))) || ((opcode ==
1384 		    LIO_WRITE) && (!sowriteable(so)))) {
1385 			TAILQ_INSERT_TAIL(&so->so_aiojobq, aiocbe, list);
1386 			TAILQ_INSERT_TAIL(&ki->kaio_sockqueue, aiocbe, plist);
1387 			if (opcode == LIO_READ)
1388 				so->so_rcv.sb_flags |= SB_AIO;
1389 			else
1390 				so->so_snd.sb_flags |= SB_AIO;
1391 			aiocbe->jobstate = JOBST_JOBQGLOBAL; /* XXX */
1392 			ki->kaio_queue_count++;
1393 			num_queue_count++;
1394 			splx(s);
1395 			error = 0;
1396 			goto done;
1397 		}
1398 		splx(s);
1399 	}
1400 
1401 	if ((error = aio_qphysio(p, aiocbe)) == 0)
1402 		goto done;
1403 	if (error > 0) {
1404 		suword(&job->_aiocb_private.status, 0);
1405 		aiocbe->uaiocb._aiocb_private.error = error;
1406 		suword(&job->_aiocb_private.error, error);
1407 		goto done;
1408 	}
1409 
1410 	/* No buffer for daemon I/O. */
1411 	aiocbe->bp = NULL;
1412 
1413 	ki->kaio_queue_count++;
1414 	if (lj)
1415 		lj->lioj_queue_count++;
1416 	s = splnet();
1417 	TAILQ_INSERT_TAIL(&ki->kaio_jobqueue, aiocbe, plist);
1418 	TAILQ_INSERT_TAIL(&aio_jobs, aiocbe, list);
1419 	splx(s);
1420 	aiocbe->jobstate = JOBST_JOBQGLOBAL;
1421 
1422 	num_queue_count++;
1423 	error = 0;
1424 
1425 	/*
1426 	 * If we don't have a free AIO process, and we are below our quota, then
1427 	 * start one.  Otherwise, depend on the subsequent I/O completions to
1428 	 * pick-up this job.  If we don't sucessfully create the new process
1429 	 * (thread) due to resource issues, we return an error for now (EAGAIN),
1430 	 * which is likely not the correct thing to do.
1431 	 */
1432 retryproc:
1433 	s = splnet();
1434 	if ((aiop = TAILQ_FIRST(&aio_freeproc)) != NULL) {
1435 		TAILQ_REMOVE(&aio_freeproc, aiop, list);
1436 		TAILQ_INSERT_TAIL(&aio_activeproc, aiop, list);
1437 		aiop->aiothreadflags &= ~AIOP_FREE;
1438 		wakeup(aiop->aiothread);
1439 	} else if (((num_aio_resv_start + num_aio_procs) < max_aio_procs) &&
1440 	    ((ki->kaio_active_count + num_aio_resv_start) <
1441 	    ki->kaio_maxactive_count)) {
1442 		num_aio_resv_start++;
1443 		if ((error = aio_newproc()) == 0) {
1444 			num_aio_resv_start--;
1445 			td->td_retval[0] = 0;
1446 			goto retryproc;
1447 		}
1448 		num_aio_resv_start--;
1449 	}
1450 	splx(s);
1451 done:
1452 	fdrop(fp, td);
1453 	return error;
1454 }
1455 
1456 /*
1457  * This routine queues an AIO request, checking for quotas.
1458  */
1459 static int
1460 aio_aqueue(struct thread *td, struct aiocb *job, int type)
1461 {
1462 	struct proc *p = td->td_proc;
1463 	struct kaioinfo *ki;
1464 
1465 	if (p->p_aioinfo == NULL)
1466 		aio_init_aioinfo(p);
1467 
1468 	if (num_queue_count >= max_queue_count)
1469 		return EAGAIN;
1470 
1471 	ki = p->p_aioinfo;
1472 	if (ki->kaio_queue_count >= ki->kaio_qallowed_count)
1473 		return EAGAIN;
1474 
1475 	return _aio_aqueue(td, job, NULL, type);
1476 }
1477 #endif /* VFS_AIO */
1478 
1479 /*
1480  * Support the aio_return system call, as a side-effect, kernel resources are
1481  * released.
1482  */
1483 int
1484 aio_return(struct thread *td, struct aio_return_args *uap)
1485 {
1486 #ifndef VFS_AIO
1487 	return ENOSYS;
1488 #else
1489 	struct proc *p = td->td_proc;
1490 	int s;
1491 	int jobref;
1492 	struct aiocblist *cb, *ncb;
1493 	struct aiocb *ujob;
1494 	struct kaioinfo *ki;
1495 
1496 	ki = p->p_aioinfo;
1497 	if (ki == NULL)
1498 		return EINVAL;
1499 
1500 	ujob = uap->aiocbp;
1501 
1502 	jobref = fuword(&ujob->_aiocb_private.kernelinfo);
1503 	if (jobref == -1 || jobref == 0)
1504 		return EINVAL;
1505 
1506 	s = splnet();
1507 	for (cb = TAILQ_FIRST(&ki->kaio_jobdone); cb; cb = TAILQ_NEXT(cb,
1508 	    plist)) {
1509 		if (((intptr_t) cb->uaiocb._aiocb_private.kernelinfo) ==
1510 		    jobref) {
1511 			splx(s);
1512 			if (ujob == cb->uuaiocb) {
1513 				td->td_retval[0] =
1514 				    cb->uaiocb._aiocb_private.status;
1515 			} else
1516 				td->td_retval[0] = EFAULT;
1517 			if (cb->uaiocb.aio_lio_opcode == LIO_WRITE) {
1518 				curproc->p_stats->p_ru.ru_oublock +=
1519 				    cb->outputcharge;
1520 				cb->outputcharge = 0;
1521 			} else if (cb->uaiocb.aio_lio_opcode == LIO_READ) {
1522 				curproc->p_stats->p_ru.ru_inblock +=
1523 				    cb->inputcharge;
1524 				cb->inputcharge = 0;
1525 			}
1526 			aio_free_entry(cb);
1527 			return 0;
1528 		}
1529 	}
1530 	splx(s);
1531 
1532 	s = splbio();
1533 	for (cb = TAILQ_FIRST(&ki->kaio_bufdone); cb; cb = ncb) {
1534 		ncb = TAILQ_NEXT(cb, plist);
1535 		if (((intptr_t) cb->uaiocb._aiocb_private.kernelinfo)
1536 		    == jobref) {
1537 			splx(s);
1538 			if (ujob == cb->uuaiocb) {
1539 				td->td_retval[0] =
1540 				    cb->uaiocb._aiocb_private.status;
1541 			} else
1542 				td->td_retval[0] = EFAULT;
1543 			aio_free_entry(cb);
1544 			return 0;
1545 		}
1546 	}
1547 	splx(s);
1548 
1549 	return (EINVAL);
1550 #endif /* VFS_AIO */
1551 }
1552 
1553 /*
1554  * Allow a process to wakeup when any of the I/O requests are completed.
1555  */
1556 int
1557 aio_suspend(struct thread *td, struct aio_suspend_args *uap)
1558 {
1559 #ifndef VFS_AIO
1560 	return ENOSYS;
1561 #else
1562 	struct proc *p = td->td_proc;
1563 	struct timeval atv;
1564 	struct timespec ts;
1565 	struct aiocb *const *cbptr, *cbp;
1566 	struct kaioinfo *ki;
1567 	struct aiocblist *cb;
1568 	int i;
1569 	int njoblist;
1570 	int error, s, timo;
1571 	int *ijoblist;
1572 	struct aiocb **ujoblist;
1573 
1574 	if (uap->nent >= AIO_LISTIO_MAX)
1575 		return EINVAL;
1576 
1577 	timo = 0;
1578 	if (uap->timeout) {
1579 		/* Get timespec struct. */
1580 		if ((error = copyin(uap->timeout, &ts, sizeof(ts))) != 0)
1581 			return error;
1582 
1583 		if (ts.tv_nsec < 0 || ts.tv_nsec >= 1000000000)
1584 			return (EINVAL);
1585 
1586 		TIMESPEC_TO_TIMEVAL(&atv, &ts);
1587 		if (itimerfix(&atv))
1588 			return (EINVAL);
1589 		timo = tvtohz(&atv);
1590 	}
1591 
1592 	ki = p->p_aioinfo;
1593 	if (ki == NULL)
1594 		return EAGAIN;
1595 
1596 	njoblist = 0;
1597 	ijoblist = zalloc(aiol_zone);
1598 	ujoblist = zalloc(aiol_zone);
1599 	cbptr = uap->aiocbp;
1600 
1601 	for (i = 0; i < uap->nent; i++) {
1602 		cbp = (struct aiocb *)(intptr_t)fuword((caddr_t)&cbptr[i]);
1603 		if (cbp == 0)
1604 			continue;
1605 		ujoblist[njoblist] = cbp;
1606 		ijoblist[njoblist] = fuword(&cbp->_aiocb_private.kernelinfo);
1607 		njoblist++;
1608 	}
1609 
1610 	if (njoblist == 0) {
1611 		zfree(aiol_zone, ijoblist);
1612 		zfree(aiol_zone, ujoblist);
1613 		return 0;
1614 	}
1615 
1616 	error = 0;
1617 	for (;;) {
1618 		for (cb = TAILQ_FIRST(&ki->kaio_jobdone); cb; cb =
1619 		    TAILQ_NEXT(cb, plist)) {
1620 			for (i = 0; i < njoblist; i++) {
1621 				if (((intptr_t)
1622 				    cb->uaiocb._aiocb_private.kernelinfo) ==
1623 				    ijoblist[i]) {
1624 					if (ujoblist[i] != cb->uuaiocb)
1625 						error = EINVAL;
1626 					zfree(aiol_zone, ijoblist);
1627 					zfree(aiol_zone, ujoblist);
1628 					return error;
1629 				}
1630 			}
1631 		}
1632 
1633 		s = splbio();
1634 		for (cb = TAILQ_FIRST(&ki->kaio_bufdone); cb; cb =
1635 		    TAILQ_NEXT(cb, plist)) {
1636 			for (i = 0; i < njoblist; i++) {
1637 				if (((intptr_t)
1638 				    cb->uaiocb._aiocb_private.kernelinfo) ==
1639 				    ijoblist[i]) {
1640 					splx(s);
1641 					if (ujoblist[i] != cb->uuaiocb)
1642 						error = EINVAL;
1643 					zfree(aiol_zone, ijoblist);
1644 					zfree(aiol_zone, ujoblist);
1645 					return error;
1646 				}
1647 			}
1648 		}
1649 
1650 		ki->kaio_flags |= KAIO_WAKEUP;
1651 		error = tsleep(p, PRIBIO | PCATCH, "aiospn", timo);
1652 		splx(s);
1653 
1654 		if (error == ERESTART || error == EINTR) {
1655 			zfree(aiol_zone, ijoblist);
1656 			zfree(aiol_zone, ujoblist);
1657 			return EINTR;
1658 		} else if (error == EWOULDBLOCK) {
1659 			zfree(aiol_zone, ijoblist);
1660 			zfree(aiol_zone, ujoblist);
1661 			return EAGAIN;
1662 		}
1663 	}
1664 
1665 /* NOTREACHED */
1666 	return EINVAL;
1667 #endif /* VFS_AIO */
1668 }
1669 
1670 /*
1671  * aio_cancel cancels any non-physio aio operations not currently in
1672  * progress.
1673  */
1674 int
1675 aio_cancel(struct thread *td, struct aio_cancel_args *uap)
1676 {
1677 #ifndef VFS_AIO
1678 	return ENOSYS;
1679 #else
1680 	struct proc *p = td->td_proc;
1681 	struct kaioinfo *ki;
1682 	struct aiocblist *cbe, *cbn;
1683 	struct file *fp;
1684 	struct filedesc *fdp;
1685 	struct socket *so;
1686 	struct proc *po;
1687 	int s,error;
1688 	int cancelled=0;
1689 	int notcancelled=0;
1690 	struct vnode *vp;
1691 
1692 	fdp = p->p_fd;
1693 
1694 	fp = fdp->fd_ofiles[uap->fd];
1695 
1696 	if (fp == NULL) {
1697 		return EBADF;
1698 	}
1699 
1700         if (fp->f_type == DTYPE_VNODE) {
1701 		vp = (struct vnode *)fp->f_data;
1702 
1703 		if (vn_isdisk(vp,&error)) {
1704 			td->td_retval[0] = AIO_NOTCANCELED;
1705         	        return 0;
1706 		}
1707 	} else if (fp->f_type == DTYPE_SOCKET) {
1708 		so = (struct socket *)fp->f_data;
1709 
1710 		s = splnet();
1711 
1712 		for (cbe = TAILQ_FIRST(&so->so_aiojobq); cbe; cbe = cbn) {
1713 			cbn = TAILQ_NEXT(cbe, list);
1714 			if ((uap->aiocbp == NULL) ||
1715 				(uap->aiocbp == cbe->uuaiocb) ) {
1716 				po = cbe->userproc;
1717 				ki = po->p_aioinfo;
1718 				TAILQ_REMOVE(&so->so_aiojobq, cbe, list);
1719 				TAILQ_REMOVE(&ki->kaio_sockqueue, cbe, plist);
1720 				TAILQ_INSERT_TAIL(&ki->kaio_jobdone, cbe, plist);
1721 				if (ki->kaio_flags & KAIO_WAKEUP) {
1722 					wakeup(po);
1723 				}
1724 				cbe->jobstate = JOBST_JOBFINISHED;
1725 				cbe->uaiocb._aiocb_private.status=-1;
1726 				cbe->uaiocb._aiocb_private.error=ECANCELED;
1727 				cancelled++;
1728 /* XXX cancelled, knote? */
1729 			        if (cbe->uaiocb.aio_sigevent.sigev_notify ==
1730 				    SIGEV_SIGNAL) {
1731 					PROC_LOCK(cbe->userproc);
1732 					psignal(cbe->userproc, cbe->uaiocb.aio_sigevent.sigev_signo);
1733 					PROC_UNLOCK(cbe->userproc);
1734 				}
1735 				if (uap->aiocbp)
1736 					break;
1737 			}
1738 		}
1739 
1740 		splx(s);
1741 
1742 		if ((cancelled) && (uap->aiocbp)) {
1743 			td->td_retval[0] = AIO_CANCELED;
1744 			return 0;
1745 		}
1746 
1747 	}
1748 
1749 	ki=p->p_aioinfo;
1750 
1751 	s = splnet();
1752 
1753 	for (cbe = TAILQ_FIRST(&ki->kaio_jobqueue); cbe; cbe = cbn) {
1754 		cbn = TAILQ_NEXT(cbe, plist);
1755 
1756 		if ((uap->fd == cbe->uaiocb.aio_fildes) &&
1757 		    ((uap->aiocbp == NULL ) ||
1758 		     (uap->aiocbp == cbe->uuaiocb))) {
1759 
1760 			if (cbe->jobstate == JOBST_JOBQGLOBAL) {
1761 				TAILQ_REMOVE(&aio_jobs, cbe, list);
1762                                 TAILQ_REMOVE(&ki->kaio_jobqueue, cbe, plist);
1763                                 TAILQ_INSERT_TAIL(&ki->kaio_jobdone, cbe,
1764                                     plist);
1765 				cancelled++;
1766 				ki->kaio_queue_finished_count++;
1767 				cbe->jobstate = JOBST_JOBFINISHED;
1768 				cbe->uaiocb._aiocb_private.status = -1;
1769 				cbe->uaiocb._aiocb_private.error = ECANCELED;
1770 /* XXX cancelled, knote? */
1771 			        if (cbe->uaiocb.aio_sigevent.sigev_notify ==
1772 				    SIGEV_SIGNAL) {
1773 					PROC_LOCK(cbe->userproc);
1774 					psignal(cbe->userproc, cbe->uaiocb.aio_sigevent.sigev_signo);
1775 					PROC_UNLOCK(cbe->userproc);
1776 				}
1777 			} else {
1778 				notcancelled++;
1779 			}
1780 		}
1781 	}
1782 
1783 	splx(s);
1784 
1785 
1786 	if (notcancelled) {
1787 		td->td_retval[0] = AIO_NOTCANCELED;
1788 		return 0;
1789 	}
1790 
1791 	if (cancelled) {
1792 		td->td_retval[0] = AIO_CANCELED;
1793 		return 0;
1794 	}
1795 
1796 	td->td_retval[0] = AIO_ALLDONE;
1797 
1798 	return 0;
1799 #endif /* VFS_AIO */
1800 }
1801 
1802 /*
1803  * aio_error is implemented in the kernel level for compatibility purposes only.
1804  * For a user mode async implementation, it would be best to do it in a userland
1805  * subroutine.
1806  */
1807 int
1808 aio_error(struct thread *td, struct aio_error_args *uap)
1809 {
1810 #ifndef VFS_AIO
1811 	return ENOSYS;
1812 #else
1813 	struct proc *p = td->td_proc;
1814 	int s;
1815 	struct aiocblist *cb;
1816 	struct kaioinfo *ki;
1817 	int jobref;
1818 
1819 	ki = p->p_aioinfo;
1820 	if (ki == NULL)
1821 		return EINVAL;
1822 
1823 	jobref = fuword(&uap->aiocbp->_aiocb_private.kernelinfo);
1824 	if ((jobref == -1) || (jobref == 0))
1825 		return EINVAL;
1826 
1827 	for (cb = TAILQ_FIRST(&ki->kaio_jobdone); cb; cb = TAILQ_NEXT(cb,
1828 	    plist)) {
1829 		if (((intptr_t)cb->uaiocb._aiocb_private.kernelinfo) ==
1830 		    jobref) {
1831 			td->td_retval[0] = cb->uaiocb._aiocb_private.error;
1832 			return 0;
1833 		}
1834 	}
1835 
1836 	s = splnet();
1837 
1838 	for (cb = TAILQ_FIRST(&ki->kaio_jobqueue); cb; cb = TAILQ_NEXT(cb,
1839 	    plist)) {
1840 		if (((intptr_t)cb->uaiocb._aiocb_private.kernelinfo) ==
1841 		    jobref) {
1842 			td->td_retval[0] = EINPROGRESS;
1843 			splx(s);
1844 			return 0;
1845 		}
1846 	}
1847 
1848 	for (cb = TAILQ_FIRST(&ki->kaio_sockqueue); cb; cb = TAILQ_NEXT(cb,
1849 	    plist)) {
1850 		if (((intptr_t)cb->uaiocb._aiocb_private.kernelinfo) ==
1851 		    jobref) {
1852 			td->td_retval[0] = EINPROGRESS;
1853 			splx(s);
1854 			return 0;
1855 		}
1856 	}
1857 	splx(s);
1858 
1859 	s = splbio();
1860 	for (cb = TAILQ_FIRST(&ki->kaio_bufdone); cb; cb = TAILQ_NEXT(cb,
1861 	    plist)) {
1862 		if (((intptr_t)cb->uaiocb._aiocb_private.kernelinfo) ==
1863 		    jobref) {
1864 			td->td_retval[0] = cb->uaiocb._aiocb_private.error;
1865 			splx(s);
1866 			return 0;
1867 		}
1868 	}
1869 
1870 	for (cb = TAILQ_FIRST(&ki->kaio_bufqueue); cb; cb = TAILQ_NEXT(cb,
1871 	    plist)) {
1872 		if (((intptr_t)cb->uaiocb._aiocb_private.kernelinfo) ==
1873 		    jobref) {
1874 			td->td_retval[0] = EINPROGRESS;
1875 			splx(s);
1876 			return 0;
1877 		}
1878 	}
1879 	splx(s);
1880 
1881 #if (0)
1882 	/*
1883 	 * Hack for lio.
1884 	 */
1885 	status = fuword(&uap->aiocbp->_aiocb_private.status);
1886 	if (status == -1)
1887 		return fuword(&uap->aiocbp->_aiocb_private.error);
1888 #endif
1889 	return EINVAL;
1890 #endif /* VFS_AIO */
1891 }
1892 
1893 int
1894 aio_read(struct thread *td, struct aio_read_args *uap)
1895 {
1896 #ifndef VFS_AIO
1897 	return ENOSYS;
1898 #else
1899 	return aio_aqueue(td, uap->aiocbp, LIO_READ);
1900 #endif /* VFS_AIO */
1901 }
1902 
1903 int
1904 aio_write(struct thread *td, struct aio_write_args *uap)
1905 {
1906 #ifndef VFS_AIO
1907 	return ENOSYS;
1908 #else
1909 	return aio_aqueue(td, uap->aiocbp, LIO_WRITE);
1910 #endif /* VFS_AIO */
1911 }
1912 
1913 int
1914 lio_listio(struct thread *td, struct lio_listio_args *uap)
1915 {
1916 #ifndef VFS_AIO
1917 	return ENOSYS;
1918 #else
1919 	struct proc *p = td->td_proc;
1920 	int nent, nentqueued;
1921 	struct aiocb *iocb, * const *cbptr;
1922 	struct aiocblist *cb;
1923 	struct kaioinfo *ki;
1924 	struct aio_liojob *lj;
1925 	int error, runningcode;
1926 	int nerror;
1927 	int i;
1928 	int s;
1929 
1930 	if ((uap->mode != LIO_NOWAIT) && (uap->mode != LIO_WAIT))
1931 		return EINVAL;
1932 
1933 	nent = uap->nent;
1934 	if (nent > AIO_LISTIO_MAX)
1935 		return EINVAL;
1936 
1937 	if (p->p_aioinfo == NULL)
1938 		aio_init_aioinfo(p);
1939 
1940 	if ((nent + num_queue_count) > max_queue_count)
1941 		return EAGAIN;
1942 
1943 	ki = p->p_aioinfo;
1944 	if ((nent + ki->kaio_queue_count) > ki->kaio_qallowed_count)
1945 		return EAGAIN;
1946 
1947 	lj = zalloc(aiolio_zone);
1948 	if (!lj)
1949 		return EAGAIN;
1950 
1951 	lj->lioj_flags = 0;
1952 	lj->lioj_buffer_count = 0;
1953 	lj->lioj_buffer_finished_count = 0;
1954 	lj->lioj_queue_count = 0;
1955 	lj->lioj_queue_finished_count = 0;
1956 	lj->lioj_ki = ki;
1957 
1958 	/*
1959 	 * Setup signal.
1960 	 */
1961 	if (uap->sig && (uap->mode == LIO_NOWAIT)) {
1962 		error = copyin(uap->sig, &lj->lioj_signal,
1963 			       sizeof(lj->lioj_signal));
1964 		if (error) {
1965 			zfree(aiolio_zone, lj);
1966 			return error;
1967 		}
1968 		if (!_SIG_VALID(lj->lioj_signal.sigev_signo)) {
1969 			zfree(aiolio_zone, lj);
1970 			return EINVAL;
1971 		}
1972 		lj->lioj_flags |= LIOJ_SIGNAL;
1973 		lj->lioj_flags &= ~LIOJ_SIGNAL_POSTED;
1974 	} else
1975 		lj->lioj_flags &= ~LIOJ_SIGNAL;
1976 
1977 	TAILQ_INSERT_TAIL(&ki->kaio_liojoblist, lj, lioj_list);
1978 	/*
1979 	 * Get pointers to the list of I/O requests.
1980 	 */
1981 	nerror = 0;
1982 	nentqueued = 0;
1983 	cbptr = uap->acb_list;
1984 	for (i = 0; i < uap->nent; i++) {
1985 		iocb = (struct aiocb *)(intptr_t)fuword((caddr_t)&cbptr[i]);
1986 		if (((intptr_t)iocb != -1) && ((intptr_t)iocb != NULL)) {
1987 			error = _aio_aqueue(td, iocb, lj, 0);
1988 			if (error == 0)
1989 				nentqueued++;
1990 			else
1991 				nerror++;
1992 		}
1993 	}
1994 
1995 	/*
1996 	 * If we haven't queued any, then just return error.
1997 	 */
1998 	if (nentqueued == 0)
1999 		return 0;
2000 
2001 	/*
2002 	 * Calculate the appropriate error return.
2003 	 */
2004 	runningcode = 0;
2005 	if (nerror)
2006 		runningcode = EIO;
2007 
2008 	if (uap->mode == LIO_WAIT) {
2009 		int command, found, jobref;
2010 
2011 		for (;;) {
2012 			found = 0;
2013 			for (i = 0; i < uap->nent; i++) {
2014 				/*
2015 				 * Fetch address of the control buf pointer in
2016 				 * user space.
2017 				 */
2018 				iocb = (struct aiocb *)(intptr_t)fuword((caddr_t)&cbptr[i]);
2019 				if (((intptr_t)iocb == -1) || ((intptr_t)iocb
2020 				    == 0))
2021 					continue;
2022 
2023 				/*
2024 				 * Fetch the associated command from user space.
2025 				 */
2026 				command = fuword(&iocb->aio_lio_opcode);
2027 				if (command == LIO_NOP) {
2028 					found++;
2029 					continue;
2030 				}
2031 
2032 				jobref = fuword(&iocb->_aiocb_private.kernelinfo);
2033 
2034 				TAILQ_FOREACH(cb, &ki->kaio_jobdone, plist) {
2035 					if (((intptr_t)cb->uaiocb._aiocb_private.kernelinfo)
2036 					    == jobref) {
2037 						if (cb->uaiocb.aio_lio_opcode
2038 						    == LIO_WRITE) {
2039 							curproc->p_stats->p_ru.ru_oublock
2040 							    +=
2041 							    cb->outputcharge;
2042 							cb->outputcharge = 0;
2043 						} else if (cb->uaiocb.aio_lio_opcode
2044 						    == LIO_READ) {
2045 							curproc->p_stats->p_ru.ru_inblock
2046 							    += cb->inputcharge;
2047 							cb->inputcharge = 0;
2048 						}
2049 						found++;
2050 						break;
2051 					}
2052 				}
2053 
2054 				s = splbio();
2055 				TAILQ_FOREACH(cb, &ki->kaio_bufdone, plist) {
2056 					if (((intptr_t)cb->uaiocb._aiocb_private.kernelinfo)
2057 					    == jobref) {
2058 						found++;
2059 						break;
2060 					}
2061 				}
2062 				splx(s);
2063 			}
2064 
2065 			/*
2066 			 * If all I/Os have been disposed of, then we can
2067 			 * return.
2068 			 */
2069 			if (found == nentqueued)
2070 				return runningcode;
2071 
2072 			ki->kaio_flags |= KAIO_WAKEUP;
2073 			error = tsleep(p, PRIBIO | PCATCH, "aiospn", 0);
2074 
2075 			if (error == EINTR)
2076 				return EINTR;
2077 			else if (error == EWOULDBLOCK)
2078 				return EAGAIN;
2079 		}
2080 	}
2081 
2082 	return runningcode;
2083 #endif /* VFS_AIO */
2084 }
2085 
2086 #ifdef VFS_AIO
2087 /*
2088  * This is a weird hack so that we can post a signal.  It is safe to do so from
2089  * a timeout routine, but *not* from an interrupt routine.
2090  */
2091 static void
2092 process_signal(void *aioj)
2093 {
2094 	struct aiocblist *aiocbe = aioj;
2095 	struct aio_liojob *lj = aiocbe->lio;
2096 	struct aiocb *cb = &aiocbe->uaiocb;
2097 
2098 	if ((lj) && (lj->lioj_signal.sigev_notify == SIGEV_SIGNAL) &&
2099 		(lj->lioj_queue_count == lj->lioj_queue_finished_count)) {
2100 		PROC_LOCK(lj->lioj_ki->kaio_p);
2101 		psignal(lj->lioj_ki->kaio_p, lj->lioj_signal.sigev_signo);
2102 		PROC_UNLOCK(lj->lioj_ki->kaio_p);
2103 		lj->lioj_flags |= LIOJ_SIGNAL_POSTED;
2104 	}
2105 
2106 	if (cb->aio_sigevent.sigev_notify == SIGEV_SIGNAL) {
2107 		PROC_LOCK(aiocbe->userproc);
2108 		psignal(aiocbe->userproc, cb->aio_sigevent.sigev_signo);
2109 		PROC_UNLOCK(aiocbe->userproc);
2110 	}
2111 }
2112 
2113 /*
2114  * Interrupt handler for physio, performs the necessary process wakeups, and
2115  * signals.
2116  */
2117 static void
2118 aio_physwakeup(struct buf *bp)
2119 {
2120 	struct aiocblist *aiocbe;
2121 	struct proc *p;
2122 	struct kaioinfo *ki;
2123 	struct aio_liojob *lj;
2124 
2125 	wakeup(bp);
2126 
2127 	aiocbe = (struct aiocblist *)bp->b_spc;
2128 	if (aiocbe) {
2129 		p = bp->b_caller1;
2130 
2131 		aiocbe->jobstate = JOBST_JOBBFINISHED;
2132 		aiocbe->uaiocb._aiocb_private.status -= bp->b_resid;
2133 		aiocbe->uaiocb._aiocb_private.error = 0;
2134 		aiocbe->jobflags |= AIOCBLIST_DONE;
2135 
2136 		if (bp->b_ioflags & BIO_ERROR)
2137 			aiocbe->uaiocb._aiocb_private.error = bp->b_error;
2138 
2139 		lj = aiocbe->lio;
2140 		if (lj) {
2141 			lj->lioj_buffer_finished_count++;
2142 
2143 			/*
2144 			 * wakeup/signal if all of the interrupt jobs are done.
2145 			 */
2146 			if (lj->lioj_buffer_finished_count ==
2147 			    lj->lioj_buffer_count) {
2148 				/*
2149 				 * Post a signal if it is called for.
2150 				 */
2151 				if ((lj->lioj_flags &
2152 				    (LIOJ_SIGNAL|LIOJ_SIGNAL_POSTED)) ==
2153 				    LIOJ_SIGNAL) {
2154 					lj->lioj_flags |= LIOJ_SIGNAL_POSTED;
2155 					aiocbe->timeouthandle =
2156 						timeout(process_signal,
2157 							aiocbe, 0);
2158 				}
2159 			}
2160 		}
2161 
2162 		ki = p->p_aioinfo;
2163 		if (ki) {
2164 			ki->kaio_buffer_finished_count++;
2165 			TAILQ_REMOVE(&aio_bufjobs, aiocbe, list);
2166 			TAILQ_REMOVE(&ki->kaio_bufqueue, aiocbe, plist);
2167 			TAILQ_INSERT_TAIL(&ki->kaio_bufdone, aiocbe, plist);
2168 
2169 			KNOTE(&aiocbe->klist, 0);
2170 			/* Do the wakeup. */
2171 			if (ki->kaio_flags & (KAIO_RUNDOWN|KAIO_WAKEUP)) {
2172 				ki->kaio_flags &= ~KAIO_WAKEUP;
2173 				wakeup(p);
2174 			}
2175 		}
2176 
2177 		if (aiocbe->uaiocb.aio_sigevent.sigev_notify == SIGEV_SIGNAL)
2178 			aiocbe->timeouthandle =
2179 				timeout(process_signal, aiocbe, 0);
2180 	}
2181 }
2182 #endif /* VFS_AIO */
2183 
2184 int
2185 aio_waitcomplete(struct thread *td, struct aio_waitcomplete_args *uap)
2186 {
2187 #ifndef VFS_AIO
2188 	return ENOSYS;
2189 #else
2190 	struct proc *p = td->td_proc;
2191 	struct timeval atv;
2192 	struct timespec ts;
2193 	struct aiocb **cbptr;
2194 	struct kaioinfo *ki;
2195 	struct aiocblist *cb = NULL;
2196 	int error, s, timo;
2197 
2198 	suword(uap->aiocbp, (int)NULL);
2199 
2200 	timo = 0;
2201 	if (uap->timeout) {
2202 		/* Get timespec struct. */
2203 		error = copyin(uap->timeout, &ts, sizeof(ts));
2204 		if (error)
2205 			return error;
2206 
2207 		if ((ts.tv_nsec < 0) || (ts.tv_nsec >= 1000000000))
2208 			return (EINVAL);
2209 
2210 		TIMESPEC_TO_TIMEVAL(&atv, &ts);
2211 		if (itimerfix(&atv))
2212 			return (EINVAL);
2213 		timo = tvtohz(&atv);
2214 	}
2215 
2216 	ki = p->p_aioinfo;
2217 	if (ki == NULL)
2218 		return EAGAIN;
2219 
2220 	cbptr = uap->aiocbp;
2221 
2222 	for (;;) {
2223 		if ((cb = TAILQ_FIRST(&ki->kaio_jobdone)) != 0) {
2224 			suword(uap->aiocbp, (int)cb->uuaiocb);
2225 			td->td_retval[0] = cb->uaiocb._aiocb_private.status;
2226 			if (cb->uaiocb.aio_lio_opcode == LIO_WRITE) {
2227 				curproc->p_stats->p_ru.ru_oublock +=
2228 				    cb->outputcharge;
2229 				cb->outputcharge = 0;
2230 			} else if (cb->uaiocb.aio_lio_opcode == LIO_READ) {
2231 				curproc->p_stats->p_ru.ru_inblock +=
2232 				    cb->inputcharge;
2233 				cb->inputcharge = 0;
2234 			}
2235 			aio_free_entry(cb);
2236 			return cb->uaiocb._aiocb_private.error;
2237 		}
2238 
2239 		s = splbio();
2240  		if ((cb = TAILQ_FIRST(&ki->kaio_bufdone)) != 0 ) {
2241 			splx(s);
2242 			suword(uap->aiocbp, (int)cb->uuaiocb);
2243 			td->td_retval[0] = cb->uaiocb._aiocb_private.status;
2244 			aio_free_entry(cb);
2245 			return cb->uaiocb._aiocb_private.error;
2246 		}
2247 
2248 		ki->kaio_flags |= KAIO_WAKEUP;
2249 		error = tsleep(p, PRIBIO | PCATCH, "aiowc", timo);
2250 		splx(s);
2251 
2252 		if (error == ERESTART)
2253 			return EINTR;
2254 		else if (error < 0)
2255 			return error;
2256 		else if (error == EINTR)
2257 			return EINTR;
2258 		else if (error == EWOULDBLOCK)
2259 			return EAGAIN;
2260 	}
2261 #endif /* VFS_AIO */
2262 }
2263 
2264 
2265 #ifndef VFS_AIO
2266 static int
2267 filt_aioattach(struct knote *kn)
2268 {
2269 
2270 	return (ENXIO);
2271 }
2272 
2273 struct filterops aio_filtops =
2274 	{ 0, filt_aioattach, NULL, NULL };
2275 
2276 #else
2277 static int
2278 filt_aioattach(struct knote *kn)
2279 {
2280 	struct aiocblist *aiocbe = (struct aiocblist *)kn->kn_id;
2281 
2282 	/*
2283 	 * The aiocbe pointer must be validated before using it, so
2284 	 * registration is restricted to the kernel; the user cannot
2285 	 * set EV_FLAG1.
2286 	 */
2287 	if ((kn->kn_flags & EV_FLAG1) == 0)
2288 		return (EPERM);
2289 	kn->kn_flags &= ~EV_FLAG1;
2290 
2291 	SLIST_INSERT_HEAD(&aiocbe->klist, kn, kn_selnext);
2292 
2293 	return (0);
2294 }
2295 
2296 static void
2297 filt_aiodetach(struct knote *kn)
2298 {
2299 	struct aiocblist *aiocbe = (struct aiocblist *)kn->kn_id;
2300 	int s = splhigh();	 /* XXX no clue, so overkill */
2301 
2302 	SLIST_REMOVE(&aiocbe->klist, kn, knote, kn_selnext);
2303 	splx(s);
2304 }
2305 
2306 /*ARGSUSED*/
2307 static int
2308 filt_aio(struct knote *kn, long hint)
2309 {
2310 	struct aiocblist *aiocbe = (struct aiocblist *)kn->kn_id;
2311 
2312 	kn->kn_data = 0;		/* XXX data returned? */
2313 	if (aiocbe->jobstate != JOBST_JOBFINISHED &&
2314 	    aiocbe->jobstate != JOBST_JOBBFINISHED)
2315 		return (0);
2316 	kn->kn_flags |= EV_EOF;
2317 	return (1);
2318 }
2319 
2320 struct filterops aio_filtops =
2321 	{ 0, filt_aioattach, filt_aiodetach, filt_aio };
2322 #endif /* VFS_AIO */
2323