xref: /freebsd/sys/kern/vfs_aio.c (revision 1e413cf93298b5b97441a21d9a50fdcd0ee9945e)
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 
17 /*
18  * This file contains support for the POSIX 1003.1B AIO/LIO facility.
19  */
20 
21 #include <sys/cdefs.h>
22 __FBSDID("$FreeBSD$");
23 
24 #include <sys/param.h>
25 #include <sys/systm.h>
26 #include <sys/malloc.h>
27 #include <sys/bio.h>
28 #include <sys/buf.h>
29 #include <sys/eventhandler.h>
30 #include <sys/sysproto.h>
31 #include <sys/filedesc.h>
32 #include <sys/kernel.h>
33 #include <sys/module.h>
34 #include <sys/kthread.h>
35 #include <sys/fcntl.h>
36 #include <sys/file.h>
37 #include <sys/limits.h>
38 #include <sys/lock.h>
39 #include <sys/mutex.h>
40 #include <sys/unistd.h>
41 #include <sys/posix4.h>
42 #include <sys/proc.h>
43 #include <sys/resourcevar.h>
44 #include <sys/signalvar.h>
45 #include <sys/protosw.h>
46 #include <sys/sema.h>
47 #include <sys/socket.h>
48 #include <sys/socketvar.h>
49 #include <sys/syscall.h>
50 #include <sys/sysent.h>
51 #include <sys/sysctl.h>
52 #include <sys/sx.h>
53 #include <sys/taskqueue.h>
54 #include <sys/vnode.h>
55 #include <sys/conf.h>
56 #include <sys/event.h>
57 #include <sys/mount.h>
58 
59 #include <machine/atomic.h>
60 
61 #include <vm/vm.h>
62 #include <vm/vm_extern.h>
63 #include <vm/pmap.h>
64 #include <vm/vm_map.h>
65 #include <vm/vm_object.h>
66 #include <vm/uma.h>
67 #include <sys/aio.h>
68 
69 #include "opt_vfs_aio.h"
70 
71 /*
72  * Counter for allocating reference ids to new jobs.  Wrapped to 1 on
73  * overflow. (XXX will be removed soon.)
74  */
75 static u_long jobrefid;
76 
77 /*
78  * Counter for aio_fsync.
79  */
80 static uint64_t jobseqno;
81 
82 #define JOBST_NULL		0
83 #define JOBST_JOBQSOCK		1
84 #define JOBST_JOBQGLOBAL	2
85 #define JOBST_JOBRUNNING	3
86 #define JOBST_JOBFINISHED	4
87 #define JOBST_JOBQBUF		5
88 #define JOBST_JOBQSYNC		6
89 
90 #ifndef MAX_AIO_PER_PROC
91 #define MAX_AIO_PER_PROC	32
92 #endif
93 
94 #ifndef MAX_AIO_QUEUE_PER_PROC
95 #define MAX_AIO_QUEUE_PER_PROC	256 /* Bigger than AIO_LISTIO_MAX */
96 #endif
97 
98 #ifndef MAX_AIO_PROCS
99 #define MAX_AIO_PROCS		32
100 #endif
101 
102 #ifndef MAX_AIO_QUEUE
103 #define	MAX_AIO_QUEUE		1024 /* Bigger than AIO_LISTIO_MAX */
104 #endif
105 
106 #ifndef TARGET_AIO_PROCS
107 #define TARGET_AIO_PROCS	4
108 #endif
109 
110 #ifndef MAX_BUF_AIO
111 #define MAX_BUF_AIO		16
112 #endif
113 
114 #ifndef AIOD_TIMEOUT_DEFAULT
115 #define	AIOD_TIMEOUT_DEFAULT	(10 * hz)
116 #endif
117 
118 #ifndef AIOD_LIFETIME_DEFAULT
119 #define AIOD_LIFETIME_DEFAULT	(30 * hz)
120 #endif
121 
122 static SYSCTL_NODE(_vfs, OID_AUTO, aio, CTLFLAG_RW, 0, "Async IO management");
123 
124 static int max_aio_procs = MAX_AIO_PROCS;
125 SYSCTL_INT(_vfs_aio, OID_AUTO, max_aio_procs,
126 	CTLFLAG_RW, &max_aio_procs, 0,
127 	"Maximum number of kernel threads to use for handling async IO ");
128 
129 static int num_aio_procs = 0;
130 SYSCTL_INT(_vfs_aio, OID_AUTO, num_aio_procs,
131 	CTLFLAG_RD, &num_aio_procs, 0,
132 	"Number of presently active kernel threads for async IO");
133 
134 /*
135  * The code will adjust the actual number of AIO processes towards this
136  * number when it gets a chance.
137  */
138 static int target_aio_procs = TARGET_AIO_PROCS;
139 SYSCTL_INT(_vfs_aio, OID_AUTO, target_aio_procs, CTLFLAG_RW, &target_aio_procs,
140 	0, "Preferred number of ready kernel threads for async IO");
141 
142 static int max_queue_count = MAX_AIO_QUEUE;
143 SYSCTL_INT(_vfs_aio, OID_AUTO, max_aio_queue, CTLFLAG_RW, &max_queue_count, 0,
144     "Maximum number of aio requests to queue, globally");
145 
146 static int num_queue_count = 0;
147 SYSCTL_INT(_vfs_aio, OID_AUTO, num_queue_count, CTLFLAG_RD, &num_queue_count, 0,
148     "Number of queued aio requests");
149 
150 static int num_buf_aio = 0;
151 SYSCTL_INT(_vfs_aio, OID_AUTO, num_buf_aio, CTLFLAG_RD, &num_buf_aio, 0,
152     "Number of aio requests presently handled by the buf subsystem");
153 
154 /* Number of async I/O thread in the process of being started */
155 /* XXX This should be local to aio_aqueue() */
156 static int num_aio_resv_start = 0;
157 
158 static int aiod_timeout;
159 SYSCTL_INT(_vfs_aio, OID_AUTO, aiod_timeout, CTLFLAG_RW, &aiod_timeout, 0,
160     "Timeout value for synchronous aio operations");
161 
162 static int aiod_lifetime;
163 SYSCTL_INT(_vfs_aio, OID_AUTO, aiod_lifetime, CTLFLAG_RW, &aiod_lifetime, 0,
164     "Maximum lifetime for idle aiod");
165 
166 static int unloadable = 0;
167 SYSCTL_INT(_vfs_aio, OID_AUTO, unloadable, CTLFLAG_RW, &unloadable, 0,
168     "Allow unload of aio (not recommended)");
169 
170 
171 static int max_aio_per_proc = MAX_AIO_PER_PROC;
172 SYSCTL_INT(_vfs_aio, OID_AUTO, max_aio_per_proc, CTLFLAG_RW, &max_aio_per_proc,
173     0, "Maximum active aio requests per process (stored in the process)");
174 
175 static int max_aio_queue_per_proc = MAX_AIO_QUEUE_PER_PROC;
176 SYSCTL_INT(_vfs_aio, OID_AUTO, max_aio_queue_per_proc, CTLFLAG_RW,
177     &max_aio_queue_per_proc, 0,
178     "Maximum queued aio requests per process (stored in the process)");
179 
180 static int max_buf_aio = MAX_BUF_AIO;
181 SYSCTL_INT(_vfs_aio, OID_AUTO, max_buf_aio, CTLFLAG_RW, &max_buf_aio, 0,
182     "Maximum buf aio requests per process (stored in the process)");
183 
184 typedef struct oaiocb {
185 	int	aio_fildes;		/* File descriptor */
186 	off_t	aio_offset;		/* File offset for I/O */
187 	volatile void *aio_buf;         /* I/O buffer in process space */
188 	size_t	aio_nbytes;		/* Number of bytes for I/O */
189 	struct	osigevent aio_sigevent;	/* Signal to deliver */
190 	int	aio_lio_opcode;		/* LIO opcode */
191 	int	aio_reqprio;		/* Request priority -- ignored */
192 	struct	__aiocb_private	_aiocb_private;
193 } oaiocb_t;
194 
195 /*
196  * Below is a key of locks used to protect each member of struct aiocblist
197  * aioliojob and kaioinfo and any backends.
198  *
199  * * - need not protected
200  * a - locked by kaioinfo lock
201  * b - locked by backend lock, the backend lock can be null in some cases,
202  *     for example, BIO belongs to this type, in this case, proc lock is
203  *     reused.
204  * c - locked by aio_job_mtx, the lock for the generic file I/O backend.
205  */
206 
207 /*
208  * Current, there is only two backends: BIO and generic file I/O.
209  * socket I/O is served by generic file I/O, this is not a good idea, since
210  * disk file I/O and any other types without O_NONBLOCK flag can block daemon
211  * threads, if there is no thread to serve socket I/O, the socket I/O will be
212  * delayed too long or starved, we should create some threads dedicated to
213  * sockets to do non-blocking I/O, same for pipe and fifo, for these I/O
214  * systems we really need non-blocking interface, fiddling O_NONBLOCK in file
215  * structure is not safe because there is race between userland and aio
216  * daemons.
217  */
218 
219 struct aiocblist {
220 	TAILQ_ENTRY(aiocblist) list;	/* (b) internal list of for backend */
221 	TAILQ_ENTRY(aiocblist) plist;	/* (a) list of jobs for each backend */
222 	TAILQ_ENTRY(aiocblist) allist;  /* (a) list of all jobs in proc */
223 	int	jobflags;		/* (a) job flags */
224 	int	jobstate;		/* (b) job state */
225 	int	inputcharge;		/* (*) input blockes */
226 	int	outputcharge;		/* (*) output blockes */
227 	struct	buf *bp;		/* (*) private to BIO backend,
228 				  	 * buffer pointer
229 					 */
230 	struct	proc *userproc;		/* (*) user process */
231 	struct  ucred *cred;		/* (*) active credential when created */
232 	struct	file *fd_file;		/* (*) pointer to file structure */
233 	struct	aioliojob *lio;		/* (*) optional lio job */
234 	struct	aiocb *uuaiocb;		/* (*) pointer in userspace of aiocb */
235 	struct	knlist klist;		/* (a) list of knotes */
236 	struct	aiocb uaiocb;		/* (*) kernel I/O control block */
237 	ksiginfo_t ksi;			/* (a) realtime signal info */
238 	struct	task biotask;		/* (*) private to BIO backend */
239 	uint64_t seqno;			/* (*) job number */
240 	int	pending;		/* (a) number of pending I/O, aio_fsync only */
241 };
242 
243 /* jobflags */
244 #define AIOCBLIST_DONE		0x01
245 #define AIOCBLIST_BUFDONE	0x02
246 #define AIOCBLIST_RUNDOWN	0x04
247 #define AIOCBLIST_CHECKSYNC	0x08
248 
249 /*
250  * AIO process info
251  */
252 #define AIOP_FREE	0x1			/* proc on free queue */
253 
254 struct aiothreadlist {
255 	int aiothreadflags;			/* (c) AIO proc flags */
256 	TAILQ_ENTRY(aiothreadlist) list;	/* (c) list of processes */
257 	struct thread *aiothread;		/* (*) the AIO thread */
258 };
259 
260 /*
261  * data-structure for lio signal management
262  */
263 struct aioliojob {
264 	int	lioj_flags;			/* (a) listio flags */
265 	int	lioj_count;			/* (a) listio flags */
266 	int	lioj_finished_count;		/* (a) listio flags */
267 	struct	sigevent lioj_signal;		/* (a) signal on all I/O done */
268 	TAILQ_ENTRY(aioliojob) lioj_list;	/* (a) lio list */
269 	struct  knlist klist;			/* (a) list of knotes */
270 	ksiginfo_t lioj_ksi;			/* (a) Realtime signal info */
271 };
272 
273 #define	LIOJ_SIGNAL		0x1	/* signal on all done (lio) */
274 #define	LIOJ_SIGNAL_POSTED	0x2	/* signal has been posted */
275 #define LIOJ_KEVENT_POSTED	0x4	/* kevent triggered */
276 
277 /*
278  * per process aio data structure
279  */
280 struct kaioinfo {
281 	struct mtx	kaio_mtx;	/* the lock to protect this struct */
282 	int	kaio_flags;		/* (a) per process kaio flags */
283 	int	kaio_maxactive_count;	/* (*) maximum number of AIOs */
284 	int	kaio_active_count;	/* (c) number of currently used AIOs */
285 	int	kaio_qallowed_count;	/* (*) maxiumu size of AIO queue */
286 	int	kaio_count;		/* (a) size of AIO queue */
287 	int	kaio_ballowed_count;	/* (*) maximum number of buffers */
288 	int	kaio_buffer_count;	/* (a) number of physio buffers */
289 	TAILQ_HEAD(,aiocblist) kaio_all;	/* (a) all AIOs in the process */
290 	TAILQ_HEAD(,aiocblist) kaio_done;	/* (a) done queue for process */
291 	TAILQ_HEAD(,aioliojob) kaio_liojoblist; /* (a) list of lio jobs */
292 	TAILQ_HEAD(,aiocblist) kaio_jobqueue;	/* (a) job queue for process */
293 	TAILQ_HEAD(,aiocblist) kaio_bufqueue;	/* (a) buffer job queue for process */
294 	TAILQ_HEAD(,aiocblist) kaio_sockqueue;  /* (a) queue for aios waiting on sockets,
295 						 *  NOT USED YET.
296 						 */
297 	TAILQ_HEAD(,aiocblist) kaio_syncqueue;	/* (a) queue for aio_fsync */
298 	struct	task	kaio_task;	/* (*) task to kick aio threads */
299 };
300 
301 #define AIO_LOCK(ki)		mtx_lock(&(ki)->kaio_mtx)
302 #define AIO_UNLOCK(ki)		mtx_unlock(&(ki)->kaio_mtx)
303 #define AIO_LOCK_ASSERT(ki, f)	mtx_assert(&(ki)->kaio_mtx, (f))
304 #define AIO_MTX(ki)		(&(ki)->kaio_mtx)
305 
306 #define KAIO_RUNDOWN	0x1	/* process is being run down */
307 #define KAIO_WAKEUP	0x2	/* wakeup process when there is a significant event */
308 
309 static TAILQ_HEAD(,aiothreadlist) aio_freeproc;		/* (c) Idle daemons */
310 static struct sema aio_newproc_sem;
311 static struct mtx aio_job_mtx;
312 static struct mtx aio_sock_mtx;
313 static TAILQ_HEAD(,aiocblist) aio_jobs;			/* (c) Async job list */
314 static struct unrhdr *aiod_unr;
315 
316 void		aio_init_aioinfo(struct proc *p);
317 static void	aio_onceonly(void);
318 static int	aio_free_entry(struct aiocblist *aiocbe);
319 static void	aio_process(struct aiocblist *aiocbe);
320 static int	aio_newproc(int *);
321 int		aio_aqueue(struct thread *td, struct aiocb *job,
322 			struct aioliojob *lio, int type, int osigev);
323 static void	aio_physwakeup(struct buf *bp);
324 static void	aio_proc_rundown(void *arg, struct proc *p);
325 static void	aio_proc_rundown_exec(void *arg, struct proc *p, struct image_params *imgp);
326 static int	aio_qphysio(struct proc *p, struct aiocblist *iocb);
327 static void	biohelper(void *, int);
328 static void	aio_daemon(void *param);
329 static void	aio_swake_cb(struct socket *, struct sockbuf *);
330 static int	aio_unload(void);
331 static void	aio_bio_done_notify(struct proc *userp, struct aiocblist *aiocbe, int type);
332 #define DONE_BUF	1
333 #define DONE_QUEUE	2
334 static int	do_lio_listio(struct thread *td, struct lio_listio_args *uap, int oldsigev);
335 static int	aio_kick(struct proc *userp);
336 static void	aio_kick_nowait(struct proc *userp);
337 static void	aio_kick_helper(void *context, int pending);
338 static int	filt_aioattach(struct knote *kn);
339 static void	filt_aiodetach(struct knote *kn);
340 static int	filt_aio(struct knote *kn, long hint);
341 static int	filt_lioattach(struct knote *kn);
342 static void	filt_liodetach(struct knote *kn);
343 static int	filt_lio(struct knote *kn, long hint);
344 
345 /*
346  * Zones for:
347  * 	kaio	Per process async io info
348  *	aiop	async io thread data
349  *	aiocb	async io jobs
350  *	aiol	list io job pointer - internal to aio_suspend XXX
351  *	aiolio	list io jobs
352  */
353 static uma_zone_t kaio_zone, aiop_zone, aiocb_zone, aiol_zone, aiolio_zone;
354 
355 /* kqueue filters for aio */
356 static struct filterops aio_filtops =
357 	{ 0, filt_aioattach, filt_aiodetach, filt_aio };
358 static struct filterops lio_filtops =
359 	{ 0, filt_lioattach, filt_liodetach, filt_lio };
360 
361 static eventhandler_tag exit_tag, exec_tag;
362 
363 TASKQUEUE_DEFINE_THREAD(aiod_bio);
364 
365 /*
366  * Main operations function for use as a kernel module.
367  */
368 static int
369 aio_modload(struct module *module, int cmd, void *arg)
370 {
371 	int error = 0;
372 
373 	switch (cmd) {
374 	case MOD_LOAD:
375 		aio_onceonly();
376 		break;
377 	case MOD_UNLOAD:
378 		error = aio_unload();
379 		break;
380 	case MOD_SHUTDOWN:
381 		break;
382 	default:
383 		error = EINVAL;
384 		break;
385 	}
386 	return (error);
387 }
388 
389 static moduledata_t aio_mod = {
390 	"aio",
391 	&aio_modload,
392 	NULL
393 };
394 
395 SYSCALL_MODULE_HELPER(aio_cancel);
396 SYSCALL_MODULE_HELPER(aio_error);
397 SYSCALL_MODULE_HELPER(aio_fsync);
398 SYSCALL_MODULE_HELPER(aio_read);
399 SYSCALL_MODULE_HELPER(aio_return);
400 SYSCALL_MODULE_HELPER(aio_suspend);
401 SYSCALL_MODULE_HELPER(aio_waitcomplete);
402 SYSCALL_MODULE_HELPER(aio_write);
403 SYSCALL_MODULE_HELPER(lio_listio);
404 SYSCALL_MODULE_HELPER(oaio_read);
405 SYSCALL_MODULE_HELPER(oaio_write);
406 SYSCALL_MODULE_HELPER(olio_listio);
407 
408 DECLARE_MODULE(aio, aio_mod,
409 	SI_SUB_VFS, SI_ORDER_ANY);
410 MODULE_VERSION(aio, 1);
411 
412 /*
413  * Startup initialization
414  */
415 static void
416 aio_onceonly(void)
417 {
418 
419 	/* XXX: should probably just use so->callback */
420 	aio_swake = &aio_swake_cb;
421 	exit_tag = EVENTHANDLER_REGISTER(process_exit, aio_proc_rundown, NULL,
422 	    EVENTHANDLER_PRI_ANY);
423 	exec_tag = EVENTHANDLER_REGISTER(process_exec, aio_proc_rundown_exec, NULL,
424 	    EVENTHANDLER_PRI_ANY);
425 	kqueue_add_filteropts(EVFILT_AIO, &aio_filtops);
426 	kqueue_add_filteropts(EVFILT_LIO, &lio_filtops);
427 	TAILQ_INIT(&aio_freeproc);
428 	sema_init(&aio_newproc_sem, 0, "aio_new_proc");
429 	mtx_init(&aio_job_mtx, "aio_job", NULL, MTX_DEF);
430 	mtx_init(&aio_sock_mtx, "aio_sock", NULL, MTX_DEF);
431 	TAILQ_INIT(&aio_jobs);
432 	aiod_unr = new_unrhdr(1, INT_MAX, NULL);
433 	kaio_zone = uma_zcreate("AIO", sizeof(struct kaioinfo), NULL, NULL,
434 	    NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
435 	aiop_zone = uma_zcreate("AIOP", sizeof(struct aiothreadlist), NULL,
436 	    NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
437 	aiocb_zone = uma_zcreate("AIOCB", sizeof(struct aiocblist), NULL, NULL,
438 	    NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
439 	aiol_zone = uma_zcreate("AIOL", AIO_LISTIO_MAX*sizeof(intptr_t) , NULL,
440 	    NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
441 	aiolio_zone = uma_zcreate("AIOLIO", sizeof(struct aioliojob), NULL,
442 	    NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
443 	aiod_timeout = AIOD_TIMEOUT_DEFAULT;
444 	aiod_lifetime = AIOD_LIFETIME_DEFAULT;
445 	jobrefid = 1;
446 	async_io_version = _POSIX_VERSION;
447 	p31b_setcfg(CTL_P1003_1B_AIO_LISTIO_MAX, AIO_LISTIO_MAX);
448 	p31b_setcfg(CTL_P1003_1B_AIO_MAX, MAX_AIO_QUEUE);
449 	p31b_setcfg(CTL_P1003_1B_AIO_PRIO_DELTA_MAX, 0);
450 }
451 
452 /*
453  * Callback for unload of AIO when used as a module.
454  */
455 static int
456 aio_unload(void)
457 {
458 	int error;
459 
460 	/*
461 	 * XXX: no unloads by default, it's too dangerous.
462 	 * perhaps we could do it if locked out callers and then
463 	 * did an aio_proc_rundown() on each process.
464 	 *
465 	 * jhb: aio_proc_rundown() needs to run on curproc though,
466 	 * so I don't think that would fly.
467 	 */
468 	if (!unloadable)
469 		return (EOPNOTSUPP);
470 
471 	error = kqueue_del_filteropts(EVFILT_AIO);
472 	if (error)
473 		return error;
474 	error = kqueue_del_filteropts(EVFILT_LIO);
475 	if (error)
476 		return error;
477 	async_io_version = 0;
478 	aio_swake = NULL;
479 	taskqueue_free(taskqueue_aiod_bio);
480 	delete_unrhdr(aiod_unr);
481 	uma_zdestroy(kaio_zone);
482 	uma_zdestroy(aiop_zone);
483 	uma_zdestroy(aiocb_zone);
484 	uma_zdestroy(aiol_zone);
485 	uma_zdestroy(aiolio_zone);
486 	EVENTHANDLER_DEREGISTER(process_exit, exit_tag);
487 	EVENTHANDLER_DEREGISTER(process_exec, exec_tag);
488 	mtx_destroy(&aio_job_mtx);
489 	mtx_destroy(&aio_sock_mtx);
490 	sema_destroy(&aio_newproc_sem);
491 	p31b_setcfg(CTL_P1003_1B_AIO_LISTIO_MAX, -1);
492 	p31b_setcfg(CTL_P1003_1B_AIO_MAX, -1);
493 	p31b_setcfg(CTL_P1003_1B_AIO_PRIO_DELTA_MAX, -1);
494 	return (0);
495 }
496 
497 /*
498  * Init the per-process aioinfo structure.  The aioinfo limits are set
499  * per-process for user limit (resource) management.
500  */
501 void
502 aio_init_aioinfo(struct proc *p)
503 {
504 	struct kaioinfo *ki;
505 
506 	ki = uma_zalloc(kaio_zone, M_WAITOK);
507 	mtx_init(&ki->kaio_mtx, "aiomtx", NULL, MTX_DEF);
508 	ki->kaio_flags = 0;
509 	ki->kaio_maxactive_count = max_aio_per_proc;
510 	ki->kaio_active_count = 0;
511 	ki->kaio_qallowed_count = max_aio_queue_per_proc;
512 	ki->kaio_count = 0;
513 	ki->kaio_ballowed_count = max_buf_aio;
514 	ki->kaio_buffer_count = 0;
515 	TAILQ_INIT(&ki->kaio_all);
516 	TAILQ_INIT(&ki->kaio_done);
517 	TAILQ_INIT(&ki->kaio_jobqueue);
518 	TAILQ_INIT(&ki->kaio_bufqueue);
519 	TAILQ_INIT(&ki->kaio_liojoblist);
520 	TAILQ_INIT(&ki->kaio_sockqueue);
521 	TAILQ_INIT(&ki->kaio_syncqueue);
522 	TASK_INIT(&ki->kaio_task, 0, aio_kick_helper, p);
523 	PROC_LOCK(p);
524 	if (p->p_aioinfo == NULL) {
525 		p->p_aioinfo = ki;
526 		PROC_UNLOCK(p);
527 	} else {
528 		PROC_UNLOCK(p);
529 		mtx_destroy(&ki->kaio_mtx);
530 		uma_zfree(kaio_zone, ki);
531 	}
532 
533 	while (num_aio_procs < target_aio_procs)
534 		aio_newproc(NULL);
535 }
536 
537 static int
538 aio_sendsig(struct proc *p, struct sigevent *sigev, ksiginfo_t *ksi)
539 {
540 	int ret = 0;
541 
542 	PROC_LOCK(p);
543 	if (!KSI_ONQ(ksi)) {
544 		ksi->ksi_code = SI_ASYNCIO;
545 		ksi->ksi_flags |= KSI_EXT | KSI_INS;
546 		ret = psignal_event(p, sigev, ksi);
547 	}
548 	PROC_UNLOCK(p);
549 	return (ret);
550 }
551 
552 /*
553  * Free a job entry.  Wait for completion if it is currently active, but don't
554  * delay forever.  If we delay, we return a flag that says that we have to
555  * restart the queue scan.
556  */
557 static int
558 aio_free_entry(struct aiocblist *aiocbe)
559 {
560 	struct kaioinfo *ki;
561 	struct aioliojob *lj;
562 	struct proc *p;
563 
564 	p = aiocbe->userproc;
565 	MPASS(curproc == p);
566 	ki = p->p_aioinfo;
567 	MPASS(ki != NULL);
568 
569 	AIO_LOCK_ASSERT(ki, MA_OWNED);
570 	MPASS(aiocbe->jobstate == JOBST_JOBFINISHED);
571 
572 	atomic_subtract_int(&num_queue_count, 1);
573 
574 	ki->kaio_count--;
575 	MPASS(ki->kaio_count >= 0);
576 
577 	TAILQ_REMOVE(&ki->kaio_done, aiocbe, plist);
578 	TAILQ_REMOVE(&ki->kaio_all, aiocbe, allist);
579 
580 	lj = aiocbe->lio;
581 	if (lj) {
582 		lj->lioj_count--;
583 		lj->lioj_finished_count--;
584 
585 		if (lj->lioj_count == 0) {
586 			TAILQ_REMOVE(&ki->kaio_liojoblist, lj, lioj_list);
587 			/* lio is going away, we need to destroy any knotes */
588 			knlist_delete(&lj->klist, curthread, 1);
589 			PROC_LOCK(p);
590 			sigqueue_take(&lj->lioj_ksi);
591 			PROC_UNLOCK(p);
592 			uma_zfree(aiolio_zone, lj);
593 		}
594 	}
595 
596 	/* aiocbe is going away, we need to destroy any knotes */
597 	knlist_delete(&aiocbe->klist, curthread, 1);
598 	PROC_LOCK(p);
599 	sigqueue_take(&aiocbe->ksi);
600 	PROC_UNLOCK(p);
601 
602 	MPASS(aiocbe->bp == NULL);
603 	aiocbe->jobstate = JOBST_NULL;
604 	AIO_UNLOCK(ki);
605 
606 	/*
607 	 * The thread argument here is used to find the owning process
608 	 * and is also passed to fo_close() which may pass it to various
609 	 * places such as devsw close() routines.  Because of that, we
610 	 * need a thread pointer from the process owning the job that is
611 	 * persistent and won't disappear out from under us or move to
612 	 * another process.
613 	 *
614 	 * Currently, all the callers of this function call it to remove
615 	 * an aiocblist from the current process' job list either via a
616 	 * syscall or due to the current process calling exit() or
617 	 * execve().  Thus, we know that p == curproc.  We also know that
618 	 * curthread can't exit since we are curthread.
619 	 *
620 	 * Therefore, we use curthread as the thread to pass to
621 	 * knlist_delete().  This does mean that it is possible for the
622 	 * thread pointer at close time to differ from the thread pointer
623 	 * at open time, but this is already true of file descriptors in
624 	 * a multithreaded process.
625 	 */
626 	fdrop(aiocbe->fd_file, curthread);
627 	crfree(aiocbe->cred);
628 	uma_zfree(aiocb_zone, aiocbe);
629 	AIO_LOCK(ki);
630 
631 	return (0);
632 }
633 
634 static void
635 aio_proc_rundown_exec(void *arg, struct proc *p, struct image_params *imgp __unused)
636 {
637    	aio_proc_rundown(arg, p);
638 }
639 
640 /*
641  * Rundown the jobs for a given process.
642  */
643 static void
644 aio_proc_rundown(void *arg, struct proc *p)
645 {
646 	struct kaioinfo *ki;
647 	struct aioliojob *lj;
648 	struct aiocblist *cbe, *cbn;
649 	struct file *fp;
650 	struct socket *so;
651 	int remove;
652 
653 	KASSERT(curthread->td_proc == p,
654 	    ("%s: called on non-curproc", __func__));
655 	ki = p->p_aioinfo;
656 	if (ki == NULL)
657 		return;
658 
659 	AIO_LOCK(ki);
660 	ki->kaio_flags |= KAIO_RUNDOWN;
661 
662 restart:
663 
664 	/*
665 	 * Try to cancel all pending requests. This code simulates
666 	 * aio_cancel on all pending I/O requests.
667 	 */
668 	TAILQ_FOREACH_SAFE(cbe, &ki->kaio_jobqueue, plist, cbn) {
669 		remove = 0;
670 		mtx_lock(&aio_job_mtx);
671 		if (cbe->jobstate == JOBST_JOBQGLOBAL) {
672 			TAILQ_REMOVE(&aio_jobs, cbe, list);
673 			remove = 1;
674 		} else if (cbe->jobstate == JOBST_JOBQSOCK) {
675 			fp = cbe->fd_file;
676 			MPASS(fp->f_type == DTYPE_SOCKET);
677 			so = fp->f_data;
678 			TAILQ_REMOVE(&so->so_aiojobq, cbe, list);
679 			remove = 1;
680 		} else if (cbe->jobstate == JOBST_JOBQSYNC) {
681 			TAILQ_REMOVE(&ki->kaio_syncqueue, cbe, list);
682 			remove = 1;
683 		}
684 		mtx_unlock(&aio_job_mtx);
685 
686 		if (remove) {
687 			cbe->jobstate = JOBST_JOBFINISHED;
688 			cbe->uaiocb._aiocb_private.status = -1;
689 			cbe->uaiocb._aiocb_private.error = ECANCELED;
690 			TAILQ_REMOVE(&ki->kaio_jobqueue, cbe, plist);
691 			aio_bio_done_notify(p, cbe, DONE_QUEUE);
692 		}
693 	}
694 
695 	/* Wait for all running I/O to be finished */
696 	if (TAILQ_FIRST(&ki->kaio_bufqueue) ||
697 	    TAILQ_FIRST(&ki->kaio_jobqueue)) {
698 		ki->kaio_flags |= KAIO_WAKEUP;
699 		msleep(&p->p_aioinfo, AIO_MTX(ki), PRIBIO, "aioprn", hz);
700 		goto restart;
701 	}
702 
703 	/* Free all completed I/O requests. */
704 	while ((cbe = TAILQ_FIRST(&ki->kaio_done)) != NULL)
705 		aio_free_entry(cbe);
706 
707 	while ((lj = TAILQ_FIRST(&ki->kaio_liojoblist)) != NULL) {
708 		if (lj->lioj_count == 0) {
709 			TAILQ_REMOVE(&ki->kaio_liojoblist, lj, lioj_list);
710 			knlist_delete(&lj->klist, curthread, 1);
711 			PROC_LOCK(p);
712 			sigqueue_take(&lj->lioj_ksi);
713 			PROC_UNLOCK(p);
714 			uma_zfree(aiolio_zone, lj);
715 		} else {
716 			panic("LIO job not cleaned up: C:%d, FC:%d\n",
717 			    lj->lioj_count, lj->lioj_finished_count);
718 		}
719 	}
720 	AIO_UNLOCK(ki);
721 	taskqueue_drain(taskqueue_aiod_bio, &ki->kaio_task);
722 	mtx_destroy(&ki->kaio_mtx);
723 	uma_zfree(kaio_zone, ki);
724 	p->p_aioinfo = NULL;
725 }
726 
727 /*
728  * Select a job to run (called by an AIO daemon).
729  */
730 static struct aiocblist *
731 aio_selectjob(struct aiothreadlist *aiop)
732 {
733 	struct aiocblist *aiocbe;
734 	struct kaioinfo *ki;
735 	struct proc *userp;
736 
737 	mtx_assert(&aio_job_mtx, MA_OWNED);
738 	TAILQ_FOREACH(aiocbe, &aio_jobs, list) {
739 		userp = aiocbe->userproc;
740 		ki = userp->p_aioinfo;
741 
742 		if (ki->kaio_active_count < ki->kaio_maxactive_count) {
743 			TAILQ_REMOVE(&aio_jobs, aiocbe, list);
744 			/* Account for currently active jobs. */
745 			ki->kaio_active_count++;
746 			aiocbe->jobstate = JOBST_JOBRUNNING;
747 			break;
748 		}
749 	}
750 	return (aiocbe);
751 }
752 
753 /*
754  *  Move all data to a permanent storage device, this code
755  *  simulates fsync syscall.
756  */
757 static int
758 aio_fsync_vnode(struct thread *td, struct vnode *vp)
759 {
760 	struct mount *mp;
761 	int vfslocked;
762 	int error;
763 
764 	vfslocked = VFS_LOCK_GIANT(vp->v_mount);
765 	if ((error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0)
766 		goto drop;
767 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
768 	if (vp->v_object != NULL) {
769 		VM_OBJECT_LOCK(vp->v_object);
770 		vm_object_page_clean(vp->v_object, 0, 0, 0);
771 		VM_OBJECT_UNLOCK(vp->v_object);
772 	}
773 	error = VOP_FSYNC(vp, MNT_WAIT, td);
774 
775 	VOP_UNLOCK(vp, 0);
776 	vn_finished_write(mp);
777 drop:
778 	VFS_UNLOCK_GIANT(vfslocked);
779 	return (error);
780 }
781 
782 /*
783  * The AIO processing activity.  This is the code that does the I/O request for
784  * the non-physio version of the operations.  The normal vn operations are used,
785  * and this code should work in all instances for every type of file, including
786  * pipes, sockets, fifos, and regular files.
787  *
788  * XXX I don't think it works well for socket, pipe, and fifo.
789  */
790 static void
791 aio_process(struct aiocblist *aiocbe)
792 {
793 	struct ucred *td_savedcred;
794 	struct thread *td;
795 	struct aiocb *cb;
796 	struct file *fp;
797 	struct socket *so;
798 	struct uio auio;
799 	struct iovec aiov;
800 	int cnt;
801 	int error;
802 	int oublock_st, oublock_end;
803 	int inblock_st, inblock_end;
804 
805 	td = curthread;
806 	td_savedcred = td->td_ucred;
807 	td->td_ucred = aiocbe->cred;
808 	cb = &aiocbe->uaiocb;
809 	fp = aiocbe->fd_file;
810 
811 	if (cb->aio_lio_opcode == LIO_SYNC) {
812 		error = 0;
813 		cnt = 0;
814 		if (fp->f_vnode != NULL)
815 			error = aio_fsync_vnode(td, fp->f_vnode);
816 		cb->_aiocb_private.error = error;
817 		cb->_aiocb_private.status = 0;
818 		td->td_ucred = td_savedcred;
819 		return;
820 	}
821 
822 	aiov.iov_base = (void *)(uintptr_t)cb->aio_buf;
823 	aiov.iov_len = cb->aio_nbytes;
824 
825 	auio.uio_iov = &aiov;
826 	auio.uio_iovcnt = 1;
827 	auio.uio_offset = cb->aio_offset;
828 	auio.uio_resid = cb->aio_nbytes;
829 	cnt = cb->aio_nbytes;
830 	auio.uio_segflg = UIO_USERSPACE;
831 	auio.uio_td = td;
832 
833 	inblock_st = td->td_ru.ru_inblock;
834 	oublock_st = td->td_ru.ru_oublock;
835 	/*
836 	 * aio_aqueue() acquires a reference to the file that is
837 	 * released in aio_free_entry().
838 	 */
839 	if (cb->aio_lio_opcode == LIO_READ) {
840 		auio.uio_rw = UIO_READ;
841 		if (auio.uio_resid == 0)
842 			error = 0;
843 		else
844 			error = fo_read(fp, &auio, fp->f_cred, FOF_OFFSET, td);
845 	} else {
846 		if (fp->f_type == DTYPE_VNODE)
847 			bwillwrite();
848 		auio.uio_rw = UIO_WRITE;
849 		error = fo_write(fp, &auio, fp->f_cred, FOF_OFFSET, td);
850 	}
851 	inblock_end = td->td_ru.ru_inblock;
852 	oublock_end = td->td_ru.ru_oublock;
853 
854 	aiocbe->inputcharge = inblock_end - inblock_st;
855 	aiocbe->outputcharge = oublock_end - oublock_st;
856 
857 	if ((error) && (auio.uio_resid != cnt)) {
858 		if (error == ERESTART || error == EINTR || error == EWOULDBLOCK)
859 			error = 0;
860 		if ((error == EPIPE) && (cb->aio_lio_opcode == LIO_WRITE)) {
861 			int sigpipe = 1;
862 			if (fp->f_type == DTYPE_SOCKET) {
863 				so = fp->f_data;
864 				if (so->so_options & SO_NOSIGPIPE)
865 					sigpipe = 0;
866 			}
867 			if (sigpipe) {
868 				PROC_LOCK(aiocbe->userproc);
869 				psignal(aiocbe->userproc, SIGPIPE);
870 				PROC_UNLOCK(aiocbe->userproc);
871 			}
872 		}
873 	}
874 
875 	cnt -= auio.uio_resid;
876 	cb->_aiocb_private.error = error;
877 	cb->_aiocb_private.status = cnt;
878 	td->td_ucred = td_savedcred;
879 }
880 
881 static void
882 aio_bio_done_notify(struct proc *userp, struct aiocblist *aiocbe, int type)
883 {
884 	struct aioliojob *lj;
885 	struct kaioinfo *ki;
886 	struct aiocblist *scb, *scbn;
887 	int lj_done;
888 
889 	ki = userp->p_aioinfo;
890 	AIO_LOCK_ASSERT(ki, MA_OWNED);
891 	lj = aiocbe->lio;
892 	lj_done = 0;
893 	if (lj) {
894 		lj->lioj_finished_count++;
895 		if (lj->lioj_count == lj->lioj_finished_count)
896 			lj_done = 1;
897 	}
898 	if (type == DONE_QUEUE) {
899 		aiocbe->jobflags |= AIOCBLIST_DONE;
900 	} else {
901 		aiocbe->jobflags |= AIOCBLIST_BUFDONE;
902 	}
903 	TAILQ_INSERT_TAIL(&ki->kaio_done, aiocbe, plist);
904 	aiocbe->jobstate = JOBST_JOBFINISHED;
905 
906 	if (ki->kaio_flags & KAIO_RUNDOWN)
907 		goto notification_done;
908 
909 	if (aiocbe->uaiocb.aio_sigevent.sigev_notify == SIGEV_SIGNAL ||
910 	    aiocbe->uaiocb.aio_sigevent.sigev_notify == SIGEV_THREAD_ID)
911 		aio_sendsig(userp, &aiocbe->uaiocb.aio_sigevent, &aiocbe->ksi);
912 
913 	KNOTE_LOCKED(&aiocbe->klist, 1);
914 
915 	if (lj_done) {
916 		if (lj->lioj_signal.sigev_notify == SIGEV_KEVENT) {
917 			lj->lioj_flags |= LIOJ_KEVENT_POSTED;
918 			KNOTE_LOCKED(&lj->klist, 1);
919 		}
920 		if ((lj->lioj_flags & (LIOJ_SIGNAL|LIOJ_SIGNAL_POSTED))
921 		    == LIOJ_SIGNAL
922 		    && (lj->lioj_signal.sigev_notify == SIGEV_SIGNAL ||
923 		        lj->lioj_signal.sigev_notify == SIGEV_THREAD_ID)) {
924 			aio_sendsig(userp, &lj->lioj_signal, &lj->lioj_ksi);
925 			lj->lioj_flags |= LIOJ_SIGNAL_POSTED;
926 		}
927 	}
928 
929 notification_done:
930 	if (aiocbe->jobflags & AIOCBLIST_CHECKSYNC) {
931 		TAILQ_FOREACH_SAFE(scb, &ki->kaio_syncqueue, list, scbn) {
932 			if (aiocbe->fd_file == scb->fd_file &&
933 			    aiocbe->seqno < scb->seqno) {
934 				if (--scb->pending == 0) {
935 					mtx_lock(&aio_job_mtx);
936 					scb->jobstate = JOBST_JOBQGLOBAL;
937 					TAILQ_REMOVE(&ki->kaio_syncqueue, scb, list);
938 					TAILQ_INSERT_TAIL(&aio_jobs, scb, list);
939 					aio_kick_nowait(userp);
940 					mtx_unlock(&aio_job_mtx);
941 				}
942 			}
943 		}
944 	}
945 	if (ki->kaio_flags & KAIO_WAKEUP) {
946 		ki->kaio_flags &= ~KAIO_WAKEUP;
947 		wakeup(&userp->p_aioinfo);
948 	}
949 }
950 
951 /*
952  * The AIO daemon, most of the actual work is done in aio_process,
953  * but the setup (and address space mgmt) is done in this routine.
954  */
955 static void
956 aio_daemon(void *_id)
957 {
958 	struct aiocblist *aiocbe;
959 	struct aiothreadlist *aiop;
960 	struct kaioinfo *ki;
961 	struct proc *curcp, *mycp, *userp;
962 	struct vmspace *myvm, *tmpvm;
963 	struct thread *td = curthread;
964 	int id = (intptr_t)_id;
965 
966 	/*
967 	 * Local copies of curproc (cp) and vmspace (myvm)
968 	 */
969 	mycp = td->td_proc;
970 	myvm = mycp->p_vmspace;
971 
972 	KASSERT(mycp->p_textvp == NULL, ("kthread has a textvp"));
973 
974 	/*
975 	 * Allocate and ready the aio control info.  There is one aiop structure
976 	 * per daemon.
977 	 */
978 	aiop = uma_zalloc(aiop_zone, M_WAITOK);
979 	aiop->aiothread = td;
980 	aiop->aiothreadflags = 0;
981 
982 	/* The daemon resides in its own pgrp. */
983 	setsid(td, NULL);
984 
985 	/*
986 	 * Wakeup parent process.  (Parent sleeps to keep from blasting away
987 	 * and creating too many daemons.)
988 	 */
989 	sema_post(&aio_newproc_sem);
990 
991 	mtx_lock(&aio_job_mtx);
992 	for (;;) {
993 		/*
994 		 * curcp is the current daemon process context.
995 		 * userp is the current user process context.
996 		 */
997 		curcp = mycp;
998 
999 		/*
1000 		 * Take daemon off of free queue
1001 		 */
1002 		if (aiop->aiothreadflags & AIOP_FREE) {
1003 			TAILQ_REMOVE(&aio_freeproc, aiop, list);
1004 			aiop->aiothreadflags &= ~AIOP_FREE;
1005 		}
1006 
1007 		/*
1008 		 * Check for jobs.
1009 		 */
1010 		while ((aiocbe = aio_selectjob(aiop)) != NULL) {
1011 			mtx_unlock(&aio_job_mtx);
1012 			userp = aiocbe->userproc;
1013 
1014 			/*
1015 			 * Connect to process address space for user program.
1016 			 */
1017 			if (userp != curcp) {
1018 				/*
1019 				 * Save the current address space that we are
1020 				 * connected to.
1021 				 */
1022 				tmpvm = mycp->p_vmspace;
1023 
1024 				/*
1025 				 * Point to the new user address space, and
1026 				 * refer to it.
1027 				 */
1028 				mycp->p_vmspace = userp->p_vmspace;
1029 				atomic_add_int(&mycp->p_vmspace->vm_refcnt, 1);
1030 
1031 				/* Activate the new mapping. */
1032 				pmap_activate(FIRST_THREAD_IN_PROC(mycp));
1033 
1034 				/*
1035 				 * If the old address space wasn't the daemons
1036 				 * own address space, then we need to remove the
1037 				 * daemon's reference from the other process
1038 				 * that it was acting on behalf of.
1039 				 */
1040 				if (tmpvm != myvm) {
1041 					vmspace_free(tmpvm);
1042 				}
1043 				curcp = userp;
1044 			}
1045 
1046 			ki = userp->p_aioinfo;
1047 
1048 			/* Do the I/O function. */
1049 			aio_process(aiocbe);
1050 
1051 			mtx_lock(&aio_job_mtx);
1052 			/* Decrement the active job count. */
1053 			ki->kaio_active_count--;
1054 			mtx_unlock(&aio_job_mtx);
1055 
1056 			AIO_LOCK(ki);
1057 			TAILQ_REMOVE(&ki->kaio_jobqueue, aiocbe, plist);
1058 			aio_bio_done_notify(userp, aiocbe, DONE_QUEUE);
1059 			AIO_UNLOCK(ki);
1060 
1061 			mtx_lock(&aio_job_mtx);
1062 		}
1063 
1064 		/*
1065 		 * Disconnect from user address space.
1066 		 */
1067 		if (curcp != mycp) {
1068 
1069 			mtx_unlock(&aio_job_mtx);
1070 
1071 			/* Get the user address space to disconnect from. */
1072 			tmpvm = mycp->p_vmspace;
1073 
1074 			/* Get original address space for daemon. */
1075 			mycp->p_vmspace = myvm;
1076 
1077 			/* Activate the daemon's address space. */
1078 			pmap_activate(FIRST_THREAD_IN_PROC(mycp));
1079 #ifdef DIAGNOSTIC
1080 			if (tmpvm == myvm) {
1081 				printf("AIOD: vmspace problem -- %d\n",
1082 				    mycp->p_pid);
1083 			}
1084 #endif
1085 			/* Remove our vmspace reference. */
1086 			vmspace_free(tmpvm);
1087 
1088 			curcp = mycp;
1089 
1090 			mtx_lock(&aio_job_mtx);
1091 			/*
1092 			 * We have to restart to avoid race, we only sleep if
1093 			 * no job can be selected, that should be
1094 			 * curcp == mycp.
1095 			 */
1096 			continue;
1097 		}
1098 
1099 		mtx_assert(&aio_job_mtx, MA_OWNED);
1100 
1101 		TAILQ_INSERT_HEAD(&aio_freeproc, aiop, list);
1102 		aiop->aiothreadflags |= AIOP_FREE;
1103 
1104 		/*
1105 		 * If daemon is inactive for a long time, allow it to exit,
1106 		 * thereby freeing resources.
1107 		 */
1108 		if (msleep(aiop->aiothread, &aio_job_mtx, PRIBIO, "aiordy",
1109 		    aiod_lifetime)) {
1110 			if (TAILQ_EMPTY(&aio_jobs)) {
1111 				if ((aiop->aiothreadflags & AIOP_FREE) &&
1112 				    (num_aio_procs > target_aio_procs)) {
1113 					TAILQ_REMOVE(&aio_freeproc, aiop, list);
1114 					num_aio_procs--;
1115 					mtx_unlock(&aio_job_mtx);
1116 					uma_zfree(aiop_zone, aiop);
1117 					free_unr(aiod_unr, id);
1118 #ifdef DIAGNOSTIC
1119 					if (mycp->p_vmspace->vm_refcnt <= 1) {
1120 						printf("AIOD: bad vm refcnt for"
1121 						    " exiting daemon: %d\n",
1122 						    mycp->p_vmspace->vm_refcnt);
1123 					}
1124 #endif
1125 					kproc_exit(0);
1126 				}
1127 			}
1128 		}
1129 	}
1130 	mtx_unlock(&aio_job_mtx);
1131 	panic("shouldn't be here\n");
1132 }
1133 
1134 /*
1135  * Create a new AIO daemon. This is mostly a kernel-thread fork routine. The
1136  * AIO daemon modifies its environment itself.
1137  */
1138 static int
1139 aio_newproc(int *start)
1140 {
1141 	int error;
1142 	struct proc *p;
1143 	int id;
1144 
1145 	id = alloc_unr(aiod_unr);
1146 	error = kproc_create(aio_daemon, (void *)(intptr_t)id, &p,
1147 		RFNOWAIT, 0, "aiod%d", id);
1148 	if (error == 0) {
1149 		/*
1150 		 * Wait until daemon is started.
1151 		 */
1152 		sema_wait(&aio_newproc_sem);
1153 		mtx_lock(&aio_job_mtx);
1154 		num_aio_procs++;
1155 		if (start != NULL)
1156 			(*start)--;
1157 		mtx_unlock(&aio_job_mtx);
1158 	} else {
1159 		free_unr(aiod_unr, id);
1160 	}
1161 	return (error);
1162 }
1163 
1164 /*
1165  * Try the high-performance, low-overhead physio method for eligible
1166  * VCHR devices.  This method doesn't use an aio helper thread, and
1167  * thus has very low overhead.
1168  *
1169  * Assumes that the caller, aio_aqueue(), has incremented the file
1170  * structure's reference count, preventing its deallocation for the
1171  * duration of this call.
1172  */
1173 static int
1174 aio_qphysio(struct proc *p, struct aiocblist *aiocbe)
1175 {
1176 	struct aiocb *cb;
1177 	struct file *fp;
1178 	struct buf *bp;
1179 	struct vnode *vp;
1180 	struct kaioinfo *ki;
1181 	struct aioliojob *lj;
1182 	int error;
1183 
1184 	cb = &aiocbe->uaiocb;
1185 	fp = aiocbe->fd_file;
1186 
1187 	if (fp->f_type != DTYPE_VNODE)
1188 		return (-1);
1189 
1190 	vp = fp->f_vnode;
1191 
1192 	/*
1193 	 * If its not a disk, we don't want to return a positive error.
1194 	 * It causes the aio code to not fall through to try the thread
1195 	 * way when you're talking to a regular file.
1196 	 */
1197 	if (!vn_isdisk(vp, &error)) {
1198 		if (error == ENOTBLK)
1199 			return (-1);
1200 		else
1201 			return (error);
1202 	}
1203 
1204 	if (vp->v_bufobj.bo_bsize == 0)
1205 		return (-1);
1206 
1207  	if (cb->aio_nbytes % vp->v_bufobj.bo_bsize)
1208 		return (-1);
1209 
1210 	if (cb->aio_nbytes > vp->v_rdev->si_iosize_max)
1211 		return (-1);
1212 
1213 	if (cb->aio_nbytes >
1214 	    MAXPHYS - (((vm_offset_t) cb->aio_buf) & PAGE_MASK))
1215 		return (-1);
1216 
1217 	ki = p->p_aioinfo;
1218 	if (ki->kaio_buffer_count >= ki->kaio_ballowed_count)
1219 		return (-1);
1220 
1221 	/* Create and build a buffer header for a transfer. */
1222 	bp = (struct buf *)getpbuf(NULL);
1223 	BUF_KERNPROC(bp);
1224 
1225 	AIO_LOCK(ki);
1226 	ki->kaio_count++;
1227 	ki->kaio_buffer_count++;
1228 	lj = aiocbe->lio;
1229 	if (lj)
1230 		lj->lioj_count++;
1231 	AIO_UNLOCK(ki);
1232 
1233 	/*
1234 	 * Get a copy of the kva from the physical buffer.
1235 	 */
1236 	error = 0;
1237 
1238 	bp->b_bcount = cb->aio_nbytes;
1239 	bp->b_bufsize = cb->aio_nbytes;
1240 	bp->b_iodone = aio_physwakeup;
1241 	bp->b_saveaddr = bp->b_data;
1242 	bp->b_data = (void *)(uintptr_t)cb->aio_buf;
1243 	bp->b_offset = cb->aio_offset;
1244 	bp->b_iooffset = cb->aio_offset;
1245 	bp->b_blkno = btodb(cb->aio_offset);
1246 	bp->b_iocmd = cb->aio_lio_opcode == LIO_WRITE ? BIO_WRITE : BIO_READ;
1247 
1248 	/*
1249 	 * Bring buffer into kernel space.
1250 	 */
1251 	if (vmapbuf(bp) < 0) {
1252 		error = EFAULT;
1253 		goto doerror;
1254 	}
1255 
1256 	AIO_LOCK(ki);
1257 	aiocbe->bp = bp;
1258 	bp->b_caller1 = (void *)aiocbe;
1259 	TAILQ_INSERT_TAIL(&ki->kaio_bufqueue, aiocbe, plist);
1260 	TAILQ_INSERT_TAIL(&ki->kaio_all, aiocbe, allist);
1261 	aiocbe->jobstate = JOBST_JOBQBUF;
1262 	cb->_aiocb_private.status = cb->aio_nbytes;
1263 	AIO_UNLOCK(ki);
1264 
1265 	atomic_add_int(&num_queue_count, 1);
1266 	atomic_add_int(&num_buf_aio, 1);
1267 
1268 	bp->b_error = 0;
1269 
1270 	TASK_INIT(&aiocbe->biotask, 0, biohelper, aiocbe);
1271 
1272 	/* Perform transfer. */
1273 	dev_strategy(vp->v_rdev, bp);
1274 	return (0);
1275 
1276 doerror:
1277 	AIO_LOCK(ki);
1278 	ki->kaio_count--;
1279 	ki->kaio_buffer_count--;
1280 	if (lj)
1281 		lj->lioj_count--;
1282 	aiocbe->bp = NULL;
1283 	AIO_UNLOCK(ki);
1284 	relpbuf(bp, NULL);
1285 	return (error);
1286 }
1287 
1288 /*
1289  * Wake up aio requests that may be serviceable now.
1290  */
1291 static void
1292 aio_swake_cb(struct socket *so, struct sockbuf *sb)
1293 {
1294 	struct aiocblist *cb, *cbn;
1295 	int opcode;
1296 
1297 	if (sb == &so->so_snd)
1298 		opcode = LIO_WRITE;
1299 	else
1300 		opcode = LIO_READ;
1301 
1302 	SOCKBUF_LOCK(sb);
1303 	sb->sb_flags &= ~SB_AIO;
1304 	mtx_lock(&aio_job_mtx);
1305 	TAILQ_FOREACH_SAFE(cb, &so->so_aiojobq, list, cbn) {
1306 		if (opcode == cb->uaiocb.aio_lio_opcode) {
1307 			if (cb->jobstate != JOBST_JOBQSOCK)
1308 				panic("invalid queue value");
1309 			/* XXX
1310 			 * We don't have actual sockets backend yet,
1311 			 * so we simply move the requests to the generic
1312 			 * file I/O backend.
1313 			 */
1314 			TAILQ_REMOVE(&so->so_aiojobq, cb, list);
1315 			TAILQ_INSERT_TAIL(&aio_jobs, cb, list);
1316 			aio_kick_nowait(cb->userproc);
1317 		}
1318 	}
1319 	mtx_unlock(&aio_job_mtx);
1320 	SOCKBUF_UNLOCK(sb);
1321 }
1322 
1323 /*
1324  * Queue a new AIO request.  Choosing either the threaded or direct physio VCHR
1325  * technique is done in this code.
1326  */
1327 int
1328 aio_aqueue(struct thread *td, struct aiocb *job, struct aioliojob *lj,
1329 	int type, int oldsigev)
1330 {
1331 	struct proc *p = td->td_proc;
1332 	struct file *fp;
1333 	struct socket *so;
1334 	struct aiocblist *aiocbe, *cb;
1335 	struct kaioinfo *ki;
1336 	struct kevent kev;
1337 	struct sockbuf *sb;
1338 	int opcode;
1339 	int error;
1340 	int fd, kqfd;
1341 	int jid;
1342 
1343 	if (p->p_aioinfo == NULL)
1344 		aio_init_aioinfo(p);
1345 
1346 	ki = p->p_aioinfo;
1347 
1348 	suword(&job->_aiocb_private.status, -1);
1349 	suword(&job->_aiocb_private.error, 0);
1350 	suword(&job->_aiocb_private.kernelinfo, -1);
1351 
1352 	if (num_queue_count >= max_queue_count ||
1353 	    ki->kaio_count >= ki->kaio_qallowed_count) {
1354 		suword(&job->_aiocb_private.error, EAGAIN);
1355 		return (EAGAIN);
1356 	}
1357 
1358 	aiocbe = uma_zalloc(aiocb_zone, M_WAITOK | M_ZERO);
1359 	aiocbe->inputcharge = 0;
1360 	aiocbe->outputcharge = 0;
1361 	knlist_init(&aiocbe->klist, AIO_MTX(ki), NULL, NULL, NULL);
1362 
1363 	if (oldsigev) {
1364 		bzero(&aiocbe->uaiocb, sizeof(struct aiocb));
1365 		error = copyin(job, &aiocbe->uaiocb, sizeof(struct oaiocb));
1366 		bcopy(&aiocbe->uaiocb.__spare__, &aiocbe->uaiocb.aio_sigevent,
1367 			sizeof(struct osigevent));
1368 	} else {
1369 		error = copyin(job, &aiocbe->uaiocb, sizeof(struct aiocb));
1370 	}
1371 	if (error) {
1372 		suword(&job->_aiocb_private.error, error);
1373 		uma_zfree(aiocb_zone, aiocbe);
1374 		return (error);
1375 	}
1376 
1377 	if (aiocbe->uaiocb.aio_sigevent.sigev_notify != SIGEV_KEVENT &&
1378 	    aiocbe->uaiocb.aio_sigevent.sigev_notify != SIGEV_SIGNAL &&
1379 	    aiocbe->uaiocb.aio_sigevent.sigev_notify != SIGEV_THREAD_ID &&
1380 	    aiocbe->uaiocb.aio_sigevent.sigev_notify != SIGEV_NONE) {
1381 		suword(&job->_aiocb_private.error, EINVAL);
1382 		uma_zfree(aiocb_zone, aiocbe);
1383 		return (EINVAL);
1384 	}
1385 
1386 	if ((aiocbe->uaiocb.aio_sigevent.sigev_notify == SIGEV_SIGNAL ||
1387 	     aiocbe->uaiocb.aio_sigevent.sigev_notify == SIGEV_THREAD_ID) &&
1388 		!_SIG_VALID(aiocbe->uaiocb.aio_sigevent.sigev_signo)) {
1389 		uma_zfree(aiocb_zone, aiocbe);
1390 		return (EINVAL);
1391 	}
1392 
1393 	ksiginfo_init(&aiocbe->ksi);
1394 
1395 	/* Save userspace address of the job info. */
1396 	aiocbe->uuaiocb = job;
1397 
1398 	/* Get the opcode. */
1399 	if (type != LIO_NOP)
1400 		aiocbe->uaiocb.aio_lio_opcode = type;
1401 	opcode = aiocbe->uaiocb.aio_lio_opcode;
1402 
1403 	/* Fetch the file object for the specified file descriptor. */
1404 	fd = aiocbe->uaiocb.aio_fildes;
1405 	switch (opcode) {
1406 	case LIO_WRITE:
1407 		error = fget_write(td, fd, &fp);
1408 		break;
1409 	case LIO_READ:
1410 		error = fget_read(td, fd, &fp);
1411 		break;
1412 	default:
1413 		error = fget(td, fd, &fp);
1414 	}
1415 	if (error) {
1416 		uma_zfree(aiocb_zone, aiocbe);
1417 		suword(&job->_aiocb_private.error, error);
1418 		return (error);
1419 	}
1420 
1421 	if (opcode == LIO_SYNC && fp->f_vnode == NULL) {
1422 		error = EINVAL;
1423 		goto aqueue_fail;
1424 	}
1425 
1426 	if (opcode != LIO_SYNC && aiocbe->uaiocb.aio_offset == -1LL) {
1427 		error = EINVAL;
1428 		goto aqueue_fail;
1429 	}
1430 
1431 	aiocbe->fd_file = fp;
1432 
1433 	mtx_lock(&aio_job_mtx);
1434 	jid = jobrefid++;
1435 	aiocbe->seqno = jobseqno++;
1436 	mtx_unlock(&aio_job_mtx);
1437 	error = suword(&job->_aiocb_private.kernelinfo, jid);
1438 	if (error) {
1439 		error = EINVAL;
1440 		goto aqueue_fail;
1441 	}
1442 	aiocbe->uaiocb._aiocb_private.kernelinfo = (void *)(intptr_t)jid;
1443 
1444 	if (opcode == LIO_NOP) {
1445 		fdrop(fp, td);
1446 		uma_zfree(aiocb_zone, aiocbe);
1447 		return (0);
1448 	}
1449 	if ((opcode != LIO_READ) && (opcode != LIO_WRITE) &&
1450 	    (opcode != LIO_SYNC)) {
1451 		error = EINVAL;
1452 		goto aqueue_fail;
1453 	}
1454 
1455 	if (aiocbe->uaiocb.aio_sigevent.sigev_notify != SIGEV_KEVENT)
1456 		goto no_kqueue;
1457 	kqfd = aiocbe->uaiocb.aio_sigevent.sigev_notify_kqueue;
1458 	kev.ident = (uintptr_t)aiocbe->uuaiocb;
1459 	kev.filter = EVFILT_AIO;
1460 	kev.flags = EV_ADD | EV_ENABLE | EV_FLAG1;
1461 	kev.data = (intptr_t)aiocbe;
1462 	kev.udata = aiocbe->uaiocb.aio_sigevent.sigev_value.sival_ptr;
1463 	error = kqfd_register(kqfd, &kev, td, 1);
1464 aqueue_fail:
1465 	if (error) {
1466 		fdrop(fp, td);
1467 		uma_zfree(aiocb_zone, aiocbe);
1468 		suword(&job->_aiocb_private.error, error);
1469 		goto done;
1470 	}
1471 no_kqueue:
1472 
1473 	suword(&job->_aiocb_private.error, EINPROGRESS);
1474 	aiocbe->uaiocb._aiocb_private.error = EINPROGRESS;
1475 	aiocbe->userproc = p;
1476 	aiocbe->cred = crhold(td->td_ucred);
1477 	aiocbe->jobflags = 0;
1478 	aiocbe->lio = lj;
1479 
1480 	if (opcode == LIO_SYNC)
1481 		goto queueit;
1482 
1483 	if (fp->f_type == DTYPE_SOCKET) {
1484 		/*
1485 		 * Alternate queueing for socket ops: Reach down into the
1486 		 * descriptor to get the socket data.  Then check to see if the
1487 		 * socket is ready to be read or written (based on the requested
1488 		 * operation).
1489 		 *
1490 		 * If it is not ready for io, then queue the aiocbe on the
1491 		 * socket, and set the flags so we get a call when sbnotify()
1492 		 * happens.
1493 		 *
1494 		 * Note if opcode is neither LIO_WRITE nor LIO_READ we lock
1495 		 * and unlock the snd sockbuf for no reason.
1496 		 */
1497 		so = fp->f_data;
1498 		sb = (opcode == LIO_READ) ? &so->so_rcv : &so->so_snd;
1499 		SOCKBUF_LOCK(sb);
1500 		if (((opcode == LIO_READ) && (!soreadable(so))) || ((opcode ==
1501 		    LIO_WRITE) && (!sowriteable(so)))) {
1502 			sb->sb_flags |= SB_AIO;
1503 
1504 			mtx_lock(&aio_job_mtx);
1505 			TAILQ_INSERT_TAIL(&so->so_aiojobq, aiocbe, list);
1506 			mtx_unlock(&aio_job_mtx);
1507 
1508 			AIO_LOCK(ki);
1509 			TAILQ_INSERT_TAIL(&ki->kaio_all, aiocbe, allist);
1510 			TAILQ_INSERT_TAIL(&ki->kaio_jobqueue, aiocbe, plist);
1511 			aiocbe->jobstate = JOBST_JOBQSOCK;
1512 			ki->kaio_count++;
1513 			if (lj)
1514 				lj->lioj_count++;
1515 			AIO_UNLOCK(ki);
1516 			SOCKBUF_UNLOCK(sb);
1517 			atomic_add_int(&num_queue_count, 1);
1518 			error = 0;
1519 			goto done;
1520 		}
1521 		SOCKBUF_UNLOCK(sb);
1522 	}
1523 
1524 	if ((error = aio_qphysio(p, aiocbe)) == 0)
1525 		goto done;
1526 #if 0
1527 	if (error > 0) {
1528 		aiocbe->uaiocb._aiocb_private.error = error;
1529 		suword(&job->_aiocb_private.error, error);
1530 		goto done;
1531 	}
1532 #endif
1533 queueit:
1534 	/* No buffer for daemon I/O. */
1535 	aiocbe->bp = NULL;
1536 	atomic_add_int(&num_queue_count, 1);
1537 
1538 	AIO_LOCK(ki);
1539 	ki->kaio_count++;
1540 	if (lj)
1541 		lj->lioj_count++;
1542 	TAILQ_INSERT_TAIL(&ki->kaio_jobqueue, aiocbe, plist);
1543 	TAILQ_INSERT_TAIL(&ki->kaio_all, aiocbe, allist);
1544 	if (opcode == LIO_SYNC) {
1545 		TAILQ_FOREACH(cb, &ki->kaio_jobqueue, plist) {
1546 			if (cb->fd_file == aiocbe->fd_file &&
1547 			    cb->uaiocb.aio_lio_opcode != LIO_SYNC &&
1548 			    cb->seqno < aiocbe->seqno) {
1549 				cb->jobflags |= AIOCBLIST_CHECKSYNC;
1550 				aiocbe->pending++;
1551 			}
1552 		}
1553 		TAILQ_FOREACH(cb, &ki->kaio_bufqueue, plist) {
1554 			if (cb->fd_file == aiocbe->fd_file &&
1555 			    cb->uaiocb.aio_lio_opcode != LIO_SYNC &&
1556 			    cb->seqno < aiocbe->seqno) {
1557 				cb->jobflags |= AIOCBLIST_CHECKSYNC;
1558 				aiocbe->pending++;
1559 			}
1560 		}
1561 		if (aiocbe->pending != 0) {
1562 			TAILQ_INSERT_TAIL(&ki->kaio_syncqueue, aiocbe, list);
1563 			aiocbe->jobstate = JOBST_JOBQSYNC;
1564 			AIO_UNLOCK(ki);
1565 			goto done;
1566 		}
1567 	}
1568 	mtx_lock(&aio_job_mtx);
1569 	TAILQ_INSERT_TAIL(&aio_jobs, aiocbe, list);
1570 	aiocbe->jobstate = JOBST_JOBQGLOBAL;
1571 	aio_kick_nowait(p);
1572 	mtx_unlock(&aio_job_mtx);
1573 	AIO_UNLOCK(ki);
1574 	error = 0;
1575 done:
1576 	return (error);
1577 }
1578 
1579 static void
1580 aio_kick_nowait(struct proc *userp)
1581 {
1582 	struct kaioinfo *ki = userp->p_aioinfo;
1583 	struct aiothreadlist *aiop;
1584 
1585 	mtx_assert(&aio_job_mtx, MA_OWNED);
1586 	if ((aiop = TAILQ_FIRST(&aio_freeproc)) != NULL) {
1587 		TAILQ_REMOVE(&aio_freeproc, aiop, list);
1588 		aiop->aiothreadflags &= ~AIOP_FREE;
1589 		wakeup(aiop->aiothread);
1590 	} else if (((num_aio_resv_start + num_aio_procs) < max_aio_procs) &&
1591 	    ((ki->kaio_active_count + num_aio_resv_start) <
1592 	    ki->kaio_maxactive_count)) {
1593 		taskqueue_enqueue(taskqueue_aiod_bio, &ki->kaio_task);
1594 	}
1595 }
1596 
1597 static int
1598 aio_kick(struct proc *userp)
1599 {
1600 	struct kaioinfo *ki = userp->p_aioinfo;
1601 	struct aiothreadlist *aiop;
1602 	int error, ret = 0;
1603 
1604 	mtx_assert(&aio_job_mtx, MA_OWNED);
1605 retryproc:
1606 	if ((aiop = TAILQ_FIRST(&aio_freeproc)) != NULL) {
1607 		TAILQ_REMOVE(&aio_freeproc, aiop, list);
1608 		aiop->aiothreadflags &= ~AIOP_FREE;
1609 		wakeup(aiop->aiothread);
1610 	} else if (((num_aio_resv_start + num_aio_procs) < max_aio_procs) &&
1611 	    ((ki->kaio_active_count + num_aio_resv_start) <
1612 	    ki->kaio_maxactive_count)) {
1613 		num_aio_resv_start++;
1614 		mtx_unlock(&aio_job_mtx);
1615 		error = aio_newproc(&num_aio_resv_start);
1616 		mtx_lock(&aio_job_mtx);
1617 		if (error) {
1618 			num_aio_resv_start--;
1619 			goto retryproc;
1620 		}
1621 	} else {
1622 		ret = -1;
1623 	}
1624 	return (ret);
1625 }
1626 
1627 static void
1628 aio_kick_helper(void *context, int pending)
1629 {
1630 	struct proc *userp = context;
1631 
1632 	mtx_lock(&aio_job_mtx);
1633 	while (--pending >= 0) {
1634 		if (aio_kick(userp))
1635 			break;
1636 	}
1637 	mtx_unlock(&aio_job_mtx);
1638 }
1639 
1640 /*
1641  * Support the aio_return system call, as a side-effect, kernel resources are
1642  * released.
1643  */
1644 int
1645 aio_return(struct thread *td, struct aio_return_args *uap)
1646 {
1647 	struct proc *p = td->td_proc;
1648 	struct aiocblist *cb;
1649 	struct aiocb *uaiocb;
1650 	struct kaioinfo *ki;
1651 	int status, error;
1652 
1653 	ki = p->p_aioinfo;
1654 	if (ki == NULL)
1655 		return (EINVAL);
1656 	uaiocb = uap->aiocbp;
1657 	AIO_LOCK(ki);
1658 	TAILQ_FOREACH(cb, &ki->kaio_done, plist) {
1659 		if (cb->uuaiocb == uaiocb)
1660 			break;
1661 	}
1662 	if (cb != NULL) {
1663 		MPASS(cb->jobstate == JOBST_JOBFINISHED);
1664 		status = cb->uaiocb._aiocb_private.status;
1665 		error = cb->uaiocb._aiocb_private.error;
1666 		td->td_retval[0] = status;
1667 		if (cb->uaiocb.aio_lio_opcode == LIO_WRITE) {
1668 			td->td_ru.ru_oublock += cb->outputcharge;
1669 			cb->outputcharge = 0;
1670 		} else if (cb->uaiocb.aio_lio_opcode == LIO_READ) {
1671 			td->td_ru.ru_inblock += cb->inputcharge;
1672 			cb->inputcharge = 0;
1673 		}
1674 		aio_free_entry(cb);
1675 		AIO_UNLOCK(ki);
1676 		suword(&uaiocb->_aiocb_private.error, error);
1677 		suword(&uaiocb->_aiocb_private.status, status);
1678 	} else {
1679 		error = EINVAL;
1680 		AIO_UNLOCK(ki);
1681 	}
1682 	return (error);
1683 }
1684 
1685 /*
1686  * Allow a process to wakeup when any of the I/O requests are completed.
1687  */
1688 int
1689 aio_suspend(struct thread *td, struct aio_suspend_args *uap)
1690 {
1691 	struct proc *p = td->td_proc;
1692 	struct timeval atv;
1693 	struct timespec ts;
1694 	struct aiocb *const *cbptr, *cbp;
1695 	struct kaioinfo *ki;
1696 	struct aiocblist *cb, *cbfirst;
1697 	struct aiocb **ujoblist;
1698 	int njoblist;
1699 	int error;
1700 	int timo;
1701 	int i;
1702 
1703 	if (uap->nent < 0 || uap->nent > AIO_LISTIO_MAX)
1704 		return (EINVAL);
1705 
1706 	timo = 0;
1707 	if (uap->timeout) {
1708 		/* Get timespec struct. */
1709 		if ((error = copyin(uap->timeout, &ts, sizeof(ts))) != 0)
1710 			return (error);
1711 
1712 		if (ts.tv_nsec < 0 || ts.tv_nsec >= 1000000000)
1713 			return (EINVAL);
1714 
1715 		TIMESPEC_TO_TIMEVAL(&atv, &ts);
1716 		if (itimerfix(&atv))
1717 			return (EINVAL);
1718 		timo = tvtohz(&atv);
1719 	}
1720 
1721 	ki = p->p_aioinfo;
1722 	if (ki == NULL)
1723 		return (EAGAIN);
1724 
1725 	njoblist = 0;
1726 	ujoblist = uma_zalloc(aiol_zone, M_WAITOK);
1727 	cbptr = uap->aiocbp;
1728 
1729 	for (i = 0; i < uap->nent; i++) {
1730 		cbp = (struct aiocb *)(intptr_t)fuword(&cbptr[i]);
1731 		if (cbp == 0)
1732 			continue;
1733 		ujoblist[njoblist] = cbp;
1734 		njoblist++;
1735 	}
1736 
1737 	if (njoblist == 0) {
1738 		uma_zfree(aiol_zone, ujoblist);
1739 		return (0);
1740 	}
1741 
1742 	AIO_LOCK(ki);
1743 	for (;;) {
1744 		cbfirst = NULL;
1745 		error = 0;
1746 		TAILQ_FOREACH(cb, &ki->kaio_all, allist) {
1747 			for (i = 0; i < njoblist; i++) {
1748 				if (cb->uuaiocb == ujoblist[i]) {
1749 					if (cbfirst == NULL)
1750 						cbfirst = cb;
1751 					if (cb->jobstate == JOBST_JOBFINISHED)
1752 						goto RETURN;
1753 				}
1754 			}
1755 		}
1756 		/* All tasks were finished. */
1757 		if (cbfirst == NULL)
1758 			break;
1759 
1760 		ki->kaio_flags |= KAIO_WAKEUP;
1761 		error = msleep(&p->p_aioinfo, AIO_MTX(ki), PRIBIO | PCATCH,
1762 		    "aiospn", timo);
1763 		if (error == ERESTART)
1764 			error = EINTR;
1765 		if (error)
1766 			break;
1767 	}
1768 RETURN:
1769 	AIO_UNLOCK(ki);
1770 	uma_zfree(aiol_zone, ujoblist);
1771 	return (error);
1772 }
1773 
1774 /*
1775  * aio_cancel cancels any non-physio aio operations not currently in
1776  * progress.
1777  */
1778 int
1779 aio_cancel(struct thread *td, struct aio_cancel_args *uap)
1780 {
1781 	struct proc *p = td->td_proc;
1782 	struct kaioinfo *ki;
1783 	struct aiocblist *cbe, *cbn;
1784 	struct file *fp;
1785 	struct socket *so;
1786 	int error;
1787 	int remove;
1788 	int cancelled = 0;
1789 	int notcancelled = 0;
1790 	struct vnode *vp;
1791 
1792 	/* Lookup file object. */
1793 	error = fget(td, uap->fd, &fp);
1794 	if (error)
1795 		return (error);
1796 
1797 	ki = p->p_aioinfo;
1798 	if (ki == NULL)
1799 		goto done;
1800 
1801 	if (fp->f_type == DTYPE_VNODE) {
1802 		vp = fp->f_vnode;
1803 		if (vn_isdisk(vp, &error)) {
1804 			fdrop(fp, td);
1805 			td->td_retval[0] = AIO_NOTCANCELED;
1806 			return (0);
1807 		}
1808 	}
1809 
1810 	AIO_LOCK(ki);
1811 	TAILQ_FOREACH_SAFE(cbe, &ki->kaio_jobqueue, plist, cbn) {
1812 		if ((uap->fd == cbe->uaiocb.aio_fildes) &&
1813 		    ((uap->aiocbp == NULL) ||
1814 		     (uap->aiocbp == cbe->uuaiocb))) {
1815 			remove = 0;
1816 
1817 			mtx_lock(&aio_job_mtx);
1818 			if (cbe->jobstate == JOBST_JOBQGLOBAL) {
1819 				TAILQ_REMOVE(&aio_jobs, cbe, list);
1820 				remove = 1;
1821 			} else if (cbe->jobstate == JOBST_JOBQSOCK) {
1822 				MPASS(fp->f_type == DTYPE_SOCKET);
1823 				so = fp->f_data;
1824 				TAILQ_REMOVE(&so->so_aiojobq, cbe, list);
1825 				remove = 1;
1826 			} else if (cbe->jobstate == JOBST_JOBQSYNC) {
1827 				TAILQ_REMOVE(&ki->kaio_syncqueue, cbe, list);
1828 				remove = 1;
1829 			}
1830 			mtx_unlock(&aio_job_mtx);
1831 
1832 			if (remove) {
1833 				TAILQ_REMOVE(&ki->kaio_jobqueue, cbe, plist);
1834 				cbe->uaiocb._aiocb_private.status = -1;
1835 				cbe->uaiocb._aiocb_private.error = ECANCELED;
1836 				aio_bio_done_notify(p, cbe, DONE_QUEUE);
1837 				cancelled++;
1838 			} else {
1839 				notcancelled++;
1840 			}
1841 			if (uap->aiocbp != NULL)
1842 				break;
1843 		}
1844 	}
1845 	AIO_UNLOCK(ki);
1846 
1847 done:
1848 	fdrop(fp, td);
1849 
1850 	if (uap->aiocbp != NULL) {
1851 		if (cancelled) {
1852 			td->td_retval[0] = AIO_CANCELED;
1853 			return (0);
1854 		}
1855 	}
1856 
1857 	if (notcancelled) {
1858 		td->td_retval[0] = AIO_NOTCANCELED;
1859 		return (0);
1860 	}
1861 
1862 	if (cancelled) {
1863 		td->td_retval[0] = AIO_CANCELED;
1864 		return (0);
1865 	}
1866 
1867 	td->td_retval[0] = AIO_ALLDONE;
1868 
1869 	return (0);
1870 }
1871 
1872 /*
1873  * aio_error is implemented in the kernel level for compatibility purposes
1874  * only.  For a user mode async implementation, it would be best to do it in
1875  * a userland subroutine.
1876  */
1877 int
1878 aio_error(struct thread *td, struct aio_error_args *uap)
1879 {
1880 	struct proc *p = td->td_proc;
1881 	struct aiocblist *cb;
1882 	struct kaioinfo *ki;
1883 	int status;
1884 
1885 	ki = p->p_aioinfo;
1886 	if (ki == NULL) {
1887 		td->td_retval[0] = EINVAL;
1888 		return (0);
1889 	}
1890 
1891 	AIO_LOCK(ki);
1892 	TAILQ_FOREACH(cb, &ki->kaio_all, allist) {
1893 		if (cb->uuaiocb == uap->aiocbp) {
1894 			if (cb->jobstate == JOBST_JOBFINISHED)
1895 				td->td_retval[0] =
1896 					cb->uaiocb._aiocb_private.error;
1897 			else
1898 				td->td_retval[0] = EINPROGRESS;
1899 			AIO_UNLOCK(ki);
1900 			return (0);
1901 		}
1902 	}
1903 	AIO_UNLOCK(ki);
1904 
1905 	/*
1906 	 * Hack for failure of aio_aqueue.
1907 	 */
1908 	status = fuword(&uap->aiocbp->_aiocb_private.status);
1909 	if (status == -1) {
1910 		td->td_retval[0] = fuword(&uap->aiocbp->_aiocb_private.error);
1911 		return (0);
1912 	}
1913 
1914 	td->td_retval[0] = EINVAL;
1915 	return (0);
1916 }
1917 
1918 /* syscall - asynchronous read from a file (REALTIME) */
1919 int
1920 oaio_read(struct thread *td, struct oaio_read_args *uap)
1921 {
1922 
1923 	return aio_aqueue(td, (struct aiocb *)uap->aiocbp, NULL, LIO_READ, 1);
1924 }
1925 
1926 int
1927 aio_read(struct thread *td, struct aio_read_args *uap)
1928 {
1929 
1930 	return aio_aqueue(td, uap->aiocbp, NULL, LIO_READ, 0);
1931 }
1932 
1933 /* syscall - asynchronous write to a file (REALTIME) */
1934 int
1935 oaio_write(struct thread *td, struct oaio_write_args *uap)
1936 {
1937 
1938 	return aio_aqueue(td, (struct aiocb *)uap->aiocbp, NULL, LIO_WRITE, 1);
1939 }
1940 
1941 int
1942 aio_write(struct thread *td, struct aio_write_args *uap)
1943 {
1944 
1945 	return aio_aqueue(td, uap->aiocbp, NULL, LIO_WRITE, 0);
1946 }
1947 
1948 /* syscall - list directed I/O (REALTIME) */
1949 int
1950 olio_listio(struct thread *td, struct olio_listio_args *uap)
1951 {
1952 	return do_lio_listio(td, (struct lio_listio_args *)uap, 1);
1953 }
1954 
1955 /* syscall - list directed I/O (REALTIME) */
1956 int
1957 lio_listio(struct thread *td, struct lio_listio_args *uap)
1958 {
1959 	return do_lio_listio(td, uap, 0);
1960 }
1961 
1962 static int
1963 do_lio_listio(struct thread *td, struct lio_listio_args *uap, int oldsigev)
1964 {
1965 	struct proc *p = td->td_proc;
1966 	struct aiocb *iocb, * const *cbptr;
1967 	struct kaioinfo *ki;
1968 	struct aioliojob *lj;
1969 	struct kevent kev;
1970 	int nent;
1971 	int error;
1972 	int nerror;
1973 	int i;
1974 
1975 	if ((uap->mode != LIO_NOWAIT) && (uap->mode != LIO_WAIT))
1976 		return (EINVAL);
1977 
1978 	nent = uap->nent;
1979 	if (nent < 0 || nent > AIO_LISTIO_MAX)
1980 		return (EINVAL);
1981 
1982 	if (p->p_aioinfo == NULL)
1983 		aio_init_aioinfo(p);
1984 
1985 	ki = p->p_aioinfo;
1986 
1987 	lj = uma_zalloc(aiolio_zone, M_WAITOK);
1988 	lj->lioj_flags = 0;
1989 	lj->lioj_count = 0;
1990 	lj->lioj_finished_count = 0;
1991 	knlist_init(&lj->klist, AIO_MTX(ki), NULL, NULL, NULL);
1992 	ksiginfo_init(&lj->lioj_ksi);
1993 
1994 	/*
1995 	 * Setup signal.
1996 	 */
1997 	if (uap->sig && (uap->mode == LIO_NOWAIT)) {
1998 		bzero(&lj->lioj_signal, sizeof(&lj->lioj_signal));
1999 		error = copyin(uap->sig, &lj->lioj_signal,
2000 				oldsigev ? sizeof(struct osigevent) :
2001 					   sizeof(struct sigevent));
2002 		if (error) {
2003 			uma_zfree(aiolio_zone, lj);
2004 			return (error);
2005 		}
2006 
2007 		if (lj->lioj_signal.sigev_notify == SIGEV_KEVENT) {
2008 			/* Assume only new style KEVENT */
2009 			kev.filter = EVFILT_LIO;
2010 			kev.flags = EV_ADD | EV_ENABLE | EV_FLAG1;
2011 			kev.ident = (uintptr_t)uap->acb_list; /* something unique */
2012 			kev.data = (intptr_t)lj;
2013 			/* pass user defined sigval data */
2014 			kev.udata = lj->lioj_signal.sigev_value.sival_ptr;
2015 			error = kqfd_register(
2016 			    lj->lioj_signal.sigev_notify_kqueue, &kev, td, 1);
2017 			if (error) {
2018 				uma_zfree(aiolio_zone, lj);
2019 				return (error);
2020 			}
2021 		} else if (lj->lioj_signal.sigev_notify == SIGEV_NONE) {
2022 			;
2023 		} else if (lj->lioj_signal.sigev_notify == SIGEV_SIGNAL ||
2024 			   lj->lioj_signal.sigev_notify == SIGEV_THREAD_ID) {
2025 				if (!_SIG_VALID(lj->lioj_signal.sigev_signo)) {
2026 					uma_zfree(aiolio_zone, lj);
2027 					return EINVAL;
2028 				}
2029 				lj->lioj_flags |= LIOJ_SIGNAL;
2030 		} else {
2031 			uma_zfree(aiolio_zone, lj);
2032 			return EINVAL;
2033 		}
2034 	}
2035 
2036 	AIO_LOCK(ki);
2037 	TAILQ_INSERT_TAIL(&ki->kaio_liojoblist, lj, lioj_list);
2038 	/*
2039 	 * Add extra aiocb count to avoid the lio to be freed
2040 	 * by other threads doing aio_waitcomplete or aio_return,
2041 	 * and prevent event from being sent until we have queued
2042 	 * all tasks.
2043 	 */
2044 	lj->lioj_count = 1;
2045 	AIO_UNLOCK(ki);
2046 
2047 	/*
2048 	 * Get pointers to the list of I/O requests.
2049 	 */
2050 	nerror = 0;
2051 	cbptr = uap->acb_list;
2052 	for (i = 0; i < uap->nent; i++) {
2053 		iocb = (struct aiocb *)(intptr_t)fuword(&cbptr[i]);
2054 		if (((intptr_t)iocb != -1) && ((intptr_t)iocb != 0)) {
2055 			error = aio_aqueue(td, iocb, lj, LIO_NOP, oldsigev);
2056 			if (error != 0)
2057 				nerror++;
2058 		}
2059 	}
2060 
2061 	error = 0;
2062 	AIO_LOCK(ki);
2063 	if (uap->mode == LIO_WAIT) {
2064 		while (lj->lioj_count - 1 != lj->lioj_finished_count) {
2065 			ki->kaio_flags |= KAIO_WAKEUP;
2066 			error = msleep(&p->p_aioinfo, AIO_MTX(ki),
2067 			    PRIBIO | PCATCH, "aiospn", 0);
2068 			if (error == ERESTART)
2069 				error = EINTR;
2070 			if (error)
2071 				break;
2072 		}
2073 	} else {
2074 		if (lj->lioj_count - 1 == lj->lioj_finished_count) {
2075 			if (lj->lioj_signal.sigev_notify == SIGEV_KEVENT) {
2076 				lj->lioj_flags |= LIOJ_KEVENT_POSTED;
2077 				KNOTE_LOCKED(&lj->klist, 1);
2078 			}
2079 			if ((lj->lioj_flags & (LIOJ_SIGNAL|LIOJ_SIGNAL_POSTED))
2080 			    == LIOJ_SIGNAL
2081 			    && (lj->lioj_signal.sigev_notify == SIGEV_SIGNAL ||
2082 			    lj->lioj_signal.sigev_notify == SIGEV_THREAD_ID)) {
2083 				aio_sendsig(p, &lj->lioj_signal,
2084 					    &lj->lioj_ksi);
2085 				lj->lioj_flags |= LIOJ_SIGNAL_POSTED;
2086 			}
2087 		}
2088 	}
2089 	lj->lioj_count--;
2090 	if (lj->lioj_count == 0) {
2091 		TAILQ_REMOVE(&ki->kaio_liojoblist, lj, lioj_list);
2092 		knlist_delete(&lj->klist, curthread, 1);
2093 		PROC_LOCK(p);
2094 		sigqueue_take(&lj->lioj_ksi);
2095 		PROC_UNLOCK(p);
2096 		AIO_UNLOCK(ki);
2097 		uma_zfree(aiolio_zone, lj);
2098 	} else
2099 		AIO_UNLOCK(ki);
2100 
2101 	if (nerror)
2102 		return (EIO);
2103 	return (error);
2104 }
2105 
2106 /*
2107  * Called from interrupt thread for physio, we should return as fast
2108  * as possible, so we schedule a biohelper task.
2109  */
2110 static void
2111 aio_physwakeup(struct buf *bp)
2112 {
2113 	struct aiocblist *aiocbe;
2114 
2115 	aiocbe = (struct aiocblist *)bp->b_caller1;
2116 	taskqueue_enqueue(taskqueue_aiod_bio, &aiocbe->biotask);
2117 }
2118 
2119 /*
2120  * Task routine to perform heavy tasks, process wakeup, and signals.
2121  */
2122 static void
2123 biohelper(void *context, int pending)
2124 {
2125 	struct aiocblist *aiocbe = context;
2126 	struct buf *bp;
2127 	struct proc *userp;
2128 	struct kaioinfo *ki;
2129 	int nblks;
2130 
2131 	bp = aiocbe->bp;
2132 	userp = aiocbe->userproc;
2133 	ki = userp->p_aioinfo;
2134 	AIO_LOCK(ki);
2135 	aiocbe->uaiocb._aiocb_private.status -= bp->b_resid;
2136 	aiocbe->uaiocb._aiocb_private.error = 0;
2137 	if (bp->b_ioflags & BIO_ERROR)
2138 		aiocbe->uaiocb._aiocb_private.error = bp->b_error;
2139 	nblks = btodb(aiocbe->uaiocb.aio_nbytes);
2140 	if (aiocbe->uaiocb.aio_lio_opcode == LIO_WRITE)
2141 		aiocbe->outputcharge += nblks;
2142 	else
2143 		aiocbe->inputcharge += nblks;
2144 	aiocbe->bp = NULL;
2145 	TAILQ_REMOVE(&userp->p_aioinfo->kaio_bufqueue, aiocbe, plist);
2146 	ki->kaio_buffer_count--;
2147 	aio_bio_done_notify(userp, aiocbe, DONE_BUF);
2148 	AIO_UNLOCK(ki);
2149 
2150 	/* Release mapping into kernel space. */
2151 	vunmapbuf(bp);
2152 	relpbuf(bp, NULL);
2153 	atomic_subtract_int(&num_buf_aio, 1);
2154 }
2155 
2156 /* syscall - wait for the next completion of an aio request */
2157 int
2158 aio_waitcomplete(struct thread *td, struct aio_waitcomplete_args *uap)
2159 {
2160 	struct proc *p = td->td_proc;
2161 	struct timeval atv;
2162 	struct timespec ts;
2163 	struct kaioinfo *ki;
2164 	struct aiocblist *cb;
2165 	struct aiocb *uuaiocb;
2166 	int error, status, timo;
2167 
2168 	suword(uap->aiocbp, (long)NULL);
2169 
2170 	timo = 0;
2171 	if (uap->timeout) {
2172 		/* Get timespec struct. */
2173 		error = copyin(uap->timeout, &ts, sizeof(ts));
2174 		if (error)
2175 			return (error);
2176 
2177 		if ((ts.tv_nsec < 0) || (ts.tv_nsec >= 1000000000))
2178 			return (EINVAL);
2179 
2180 		TIMESPEC_TO_TIMEVAL(&atv, &ts);
2181 		if (itimerfix(&atv))
2182 			return (EINVAL);
2183 		timo = tvtohz(&atv);
2184 	}
2185 
2186 	if (p->p_aioinfo == NULL)
2187 		aio_init_aioinfo(p);
2188 	ki = p->p_aioinfo;
2189 
2190 	error = 0;
2191 	cb = NULL;
2192 	AIO_LOCK(ki);
2193 	while ((cb = TAILQ_FIRST(&ki->kaio_done)) == NULL) {
2194 		ki->kaio_flags |= KAIO_WAKEUP;
2195 		error = msleep(&p->p_aioinfo, AIO_MTX(ki), PRIBIO | PCATCH,
2196 		    "aiowc", timo);
2197 		if (timo && error == ERESTART)
2198 			error = EINTR;
2199 		if (error)
2200 			break;
2201 	}
2202 
2203 	if (cb != NULL) {
2204 		MPASS(cb->jobstate == JOBST_JOBFINISHED);
2205 		uuaiocb = cb->uuaiocb;
2206 		status = cb->uaiocb._aiocb_private.status;
2207 		error = cb->uaiocb._aiocb_private.error;
2208 		td->td_retval[0] = status;
2209 		if (cb->uaiocb.aio_lio_opcode == LIO_WRITE) {
2210 			td->td_ru.ru_oublock += cb->outputcharge;
2211 			cb->outputcharge = 0;
2212 		} else if (cb->uaiocb.aio_lio_opcode == LIO_READ) {
2213 			td->td_ru.ru_inblock += cb->inputcharge;
2214 			cb->inputcharge = 0;
2215 		}
2216 		aio_free_entry(cb);
2217 		AIO_UNLOCK(ki);
2218 		suword(uap->aiocbp, (long)uuaiocb);
2219 		suword(&uuaiocb->_aiocb_private.error, error);
2220 		suword(&uuaiocb->_aiocb_private.status, status);
2221 	} else
2222 		AIO_UNLOCK(ki);
2223 
2224 	return (error);
2225 }
2226 
2227 int
2228 aio_fsync(struct thread *td, struct aio_fsync_args *uap)
2229 {
2230 	struct proc *p = td->td_proc;
2231 	struct kaioinfo *ki;
2232 
2233 	if (uap->op != O_SYNC) /* XXX lack of O_DSYNC */
2234 		return (EINVAL);
2235 	ki = p->p_aioinfo;
2236 	if (ki == NULL)
2237 		aio_init_aioinfo(p);
2238 	return aio_aqueue(td, uap->aiocbp, NULL, LIO_SYNC, 0);
2239 }
2240 
2241 /* kqueue attach function */
2242 static int
2243 filt_aioattach(struct knote *kn)
2244 {
2245 	struct aiocblist *aiocbe = (struct aiocblist *)kn->kn_sdata;
2246 
2247 	/*
2248 	 * The aiocbe pointer must be validated before using it, so
2249 	 * registration is restricted to the kernel; the user cannot
2250 	 * set EV_FLAG1.
2251 	 */
2252 	if ((kn->kn_flags & EV_FLAG1) == 0)
2253 		return (EPERM);
2254 	kn->kn_flags &= ~EV_FLAG1;
2255 
2256 	knlist_add(&aiocbe->klist, kn, 0);
2257 
2258 	return (0);
2259 }
2260 
2261 /* kqueue detach function */
2262 static void
2263 filt_aiodetach(struct knote *kn)
2264 {
2265 	struct aiocblist *aiocbe = (struct aiocblist *)kn->kn_sdata;
2266 
2267 	if (!knlist_empty(&aiocbe->klist))
2268 		knlist_remove(&aiocbe->klist, kn, 0);
2269 }
2270 
2271 /* kqueue filter function */
2272 /*ARGSUSED*/
2273 static int
2274 filt_aio(struct knote *kn, long hint)
2275 {
2276 	struct aiocblist *aiocbe = (struct aiocblist *)kn->kn_sdata;
2277 
2278 	kn->kn_data = aiocbe->uaiocb._aiocb_private.error;
2279 	if (aiocbe->jobstate != JOBST_JOBFINISHED)
2280 		return (0);
2281 	kn->kn_flags |= EV_EOF;
2282 	return (1);
2283 }
2284 
2285 /* kqueue attach function */
2286 static int
2287 filt_lioattach(struct knote *kn)
2288 {
2289 	struct aioliojob * lj = (struct aioliojob *)kn->kn_sdata;
2290 
2291 	/*
2292 	 * The aioliojob pointer must be validated before using it, so
2293 	 * registration is restricted to the kernel; the user cannot
2294 	 * set EV_FLAG1.
2295 	 */
2296 	if ((kn->kn_flags & EV_FLAG1) == 0)
2297 		return (EPERM);
2298 	kn->kn_flags &= ~EV_FLAG1;
2299 
2300 	knlist_add(&lj->klist, kn, 0);
2301 
2302 	return (0);
2303 }
2304 
2305 /* kqueue detach function */
2306 static void
2307 filt_liodetach(struct knote *kn)
2308 {
2309 	struct aioliojob * lj = (struct aioliojob *)kn->kn_sdata;
2310 
2311 	if (!knlist_empty(&lj->klist))
2312 		knlist_remove(&lj->klist, kn, 0);
2313 }
2314 
2315 /* kqueue filter function */
2316 /*ARGSUSED*/
2317 static int
2318 filt_lio(struct knote *kn, long hint)
2319 {
2320 	struct aioliojob * lj = (struct aioliojob *)kn->kn_sdata;
2321 
2322 	return (lj->lioj_flags & LIOJ_KEVENT_POSTED);
2323 }
2324