FreeBSD/Linux Kernel Cross Reference
sys/kern/vfs_aio.c

     /*-
      * Copyright (c) 1997 John S. Dyson.  All rights reserved.
      *
      * Redistribution and use in source and binary forms, with or without
      * modification, are permitted provided that the following conditions
      * are met:
      * 1. Redistributions of source code must retain the above copyright
      *    notice, this list of conditions and the following disclaimer.
      * 2. John S. Dyson's name may not be used to endorse or promote products
     *    derived from this software without specific prior written permission.
     *
     * DISCLAIMER:  This code isn't warranted to do anything useful.  Anything
     * bad that happens because of using this software isn't the responsibility
     * of the author.  This software is distributed AS-IS.
     */
    
    /*
     * This file contains support for the POSIX 1003.1B AIO/LIO facility.
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD$");
    
    #include "opt_compat.h"
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/malloc.h>
    #include <sys/bio.h>
    #include <sys/buf.h>
    #include <sys/capsicum.h>
    #include <sys/eventhandler.h>
    #include <sys/sysproto.h>
    #include <sys/filedesc.h>
    #include <sys/kernel.h>
    #include <sys/module.h>
    #include <sys/kthread.h>
    #include <sys/fcntl.h>
    #include <sys/file.h>
    #include <sys/limits.h>
    #include <sys/lock.h>
    #include <sys/mutex.h>
    #include <sys/unistd.h>
    #include <sys/posix4.h>
    #include <sys/proc.h>
    #include <sys/resourcevar.h>
    #include <sys/signalvar.h>
    #include <sys/syscallsubr.h>
    #include <sys/protosw.h>
    #include <sys/rwlock.h>
    #include <sys/sema.h>
    #include <sys/socket.h>
    #include <sys/socketvar.h>
    #include <sys/syscall.h>
    #include <sys/sysent.h>
    #include <sys/sysctl.h>
    #include <sys/syslog.h>
    #include <sys/sx.h>
    #include <sys/taskqueue.h>
    #include <sys/vnode.h>
    #include <sys/conf.h>
    #include <sys/event.h>
    #include <sys/mount.h>
    #include <geom/geom.h>
    
    #include <machine/atomic.h>
    
    #include <vm/vm.h>
    #include <vm/vm_page.h>
    #include <vm/vm_extern.h>
    #include <vm/pmap.h>
    #include <vm/vm_map.h>
    #include <vm/vm_object.h>
    #include <vm/uma.h>
    #include <sys/aio.h>
    
    /*
     * Counter for allocating reference ids to new jobs.  Wrapped to 1 on
     * overflow. (XXX will be removed soon.)
     */
    static u_long jobrefid;
    
    /*
     * Counter for aio_fsync.
     */
    static uint64_t jobseqno;
    
    #ifndef MAX_AIO_PER_PROC
    #define MAX_AIO_PER_PROC        32
    #endif
    
    #ifndef MAX_AIO_QUEUE_PER_PROC
    #define MAX_AIO_QUEUE_PER_PROC  256
    #endif
    
    #ifndef MAX_AIO_QUEUE
    #define MAX_AIO_QUEUE           1024 /* Bigger than MAX_AIO_QUEUE_PER_PROC */
    #endif
    
   #ifndef MAX_BUF_AIO
   #define MAX_BUF_AIO             16
   #endif
   
   FEATURE(aio, "Asynchronous I/O");
   SYSCTL_DECL(_p1003_1b);
   
   static MALLOC_DEFINE(M_LIO, "lio", "listio aio control block list");
   static MALLOC_DEFINE(M_AIOS, "aios", "aio_suspend aio control block list");
   
   static SYSCTL_NODE(_vfs, OID_AUTO, aio, CTLFLAG_RW, 0,
       "Async IO management");
   
   static int enable_aio_unsafe = 0;
   SYSCTL_INT(_vfs_aio, OID_AUTO, enable_unsafe, CTLFLAG_RW, &enable_aio_unsafe, 0,
       "Permit asynchronous IO on all file types, not just known-safe types");
   
   static unsigned int unsafe_warningcnt = 1;
   SYSCTL_UINT(_vfs_aio, OID_AUTO, unsafe_warningcnt, CTLFLAG_RW,
       &unsafe_warningcnt, 0,
       "Warnings that will be triggered upon failed IO requests on unsafe files");
   
   static int max_aio_procs = MAX_AIO_PROCS;
   SYSCTL_INT(_vfs_aio, OID_AUTO, max_aio_procs, CTLFLAG_RW, &max_aio_procs, 0,
       "Maximum number of kernel processes to use for handling async IO ");
   
   static int num_aio_procs = 0;
   SYSCTL_INT(_vfs_aio, OID_AUTO, num_aio_procs, CTLFLAG_RD, &num_aio_procs, 0,
       "Number of presently active kernel processes for async IO");
   
   /*
    * The code will adjust the actual number of AIO processes towards this
    * number when it gets a chance.
    */
   static int target_aio_procs = TARGET_AIO_PROCS;
   SYSCTL_INT(_vfs_aio, OID_AUTO, target_aio_procs, CTLFLAG_RW, &target_aio_procs,
       0,
       "Preferred number of ready kernel processes for async IO");
   
   static int max_queue_count = MAX_AIO_QUEUE;
   SYSCTL_INT(_vfs_aio, OID_AUTO, max_aio_queue, CTLFLAG_RW, &max_queue_count, 0,
       "Maximum number of aio requests to queue, globally");
   
   static int num_queue_count = 0;
   SYSCTL_INT(_vfs_aio, OID_AUTO, num_queue_count, CTLFLAG_RD, &num_queue_count, 0,
       "Number of queued aio requests");
   
   static int num_buf_aio = 0;
   SYSCTL_INT(_vfs_aio, OID_AUTO, num_buf_aio, CTLFLAG_RD, &num_buf_aio, 0,
       "Number of aio requests presently handled by the buf subsystem");
   
   static int num_unmapped_aio = 0;
   SYSCTL_INT(_vfs_aio, OID_AUTO, num_unmapped_aio, CTLFLAG_RD, &num_unmapped_aio,
       0,
       "Number of aio requests presently handled by unmapped I/O buffers");
   
   /* Number of async I/O processes in the process of being started */
   /* XXX This should be local to aio_aqueue() */
   static int num_aio_resv_start = 0;
   
   static int aiod_lifetime;
   SYSCTL_INT(_vfs_aio, OID_AUTO, aiod_lifetime, CTLFLAG_RW, &aiod_lifetime, 0,
       "Maximum lifetime for idle aiod");
   
   static int max_aio_per_proc = MAX_AIO_PER_PROC;
   SYSCTL_INT(_vfs_aio, OID_AUTO, max_aio_per_proc, CTLFLAG_RW, &max_aio_per_proc,
       0,
       "Maximum active aio requests per process");
   
   static int max_aio_queue_per_proc = MAX_AIO_QUEUE_PER_PROC;
   SYSCTL_INT(_vfs_aio, OID_AUTO, max_aio_queue_per_proc, CTLFLAG_RW,
       &max_aio_queue_per_proc, 0,
       "Maximum queued aio requests per process");
   
   static int max_buf_aio = MAX_BUF_AIO;
   SYSCTL_INT(_vfs_aio, OID_AUTO, max_buf_aio, CTLFLAG_RW, &max_buf_aio, 0,
       "Maximum buf aio requests per process");
   
   /* 
    * Though redundant with vfs.aio.max_aio_queue_per_proc, POSIX requires
    * sysconf(3) to support AIO_LISTIO_MAX, and we implement that with
    * vfs.aio.aio_listio_max.
    */
   SYSCTL_INT(_p1003_1b, CTL_P1003_1B_AIO_LISTIO_MAX, aio_listio_max,
       CTLFLAG_RD | CTLFLAG_CAPRD, &max_aio_queue_per_proc,
       0, "Maximum aio requests for a single lio_listio call");
   
   #ifdef COMPAT_FREEBSD6
   typedef struct oaiocb {
           int     aio_fildes;             /* File descriptor */
           off_t   aio_offset;             /* File offset for I/O */
           volatile void *aio_buf;         /* I/O buffer in process space */
           size_t  aio_nbytes;             /* Number of bytes for I/O */
           struct  osigevent aio_sigevent; /* Signal to deliver */
           int     aio_lio_opcode;         /* LIO opcode */
           int     aio_reqprio;            /* Request priority -- ignored */
           struct  __aiocb_private _aiocb_private;
   } oaiocb_t;
   #endif
   
   /*
    * Below is a key of locks used to protect each member of struct kaiocb
    * aioliojob and kaioinfo and any backends.
    *
    * * - need not protected
    * a - locked by kaioinfo lock
    * b - locked by backend lock, the backend lock can be null in some cases,
    *     for example, BIO belongs to this type, in this case, proc lock is
    *     reused.
    * c - locked by aio_job_mtx, the lock for the generic file I/O backend.
    */
   
   /*
    * If the routine that services an AIO request blocks while running in an
    * AIO kernel process it can starve other I/O requests.  BIO requests
    * queued via aio_qbio() complete asynchronously and do not use AIO kernel
    * processes at all.  Socket I/O requests use a separate pool of
    * kprocs and also force non-blocking I/O.  Other file I/O requests
    * use the generic fo_read/fo_write operations which can block.  The
    * fsync and mlock operations can also block while executing.  Ideally
    * none of these requests would block while executing.
    *
    * Note that the service routines cannot toggle O_NONBLOCK in the file
    * structure directly while handling a request due to races with
    * userland threads.
    */
   
   /* jobflags */
   #define KAIOCB_QUEUEING         0x01
   #define KAIOCB_CANCELLED        0x02
   #define KAIOCB_CANCELLING       0x04
   #define KAIOCB_CHECKSYNC        0x08
   #define KAIOCB_CLEARED          0x10
   #define KAIOCB_FINISHED         0x20
   
   /*
    * AIO process info
    */
   #define AIOP_FREE       0x1                     /* proc on free queue */
   
   struct aioproc {
           int     aioprocflags;                   /* (c) AIO proc flags */
           TAILQ_ENTRY(aioproc) list;              /* (c) list of processes */
           struct  proc *aioproc;                  /* (*) the AIO proc */
   };
   
   /*
    * data-structure for lio signal management
    */
   struct aioliojob {
           int     lioj_flags;                     /* (a) listio flags */
           int     lioj_count;                     /* (a) listio flags */
           int     lioj_finished_count;            /* (a) listio flags */
           struct  sigevent lioj_signal;           /* (a) signal on all I/O done */
           TAILQ_ENTRY(aioliojob) lioj_list;       /* (a) lio list */
           struct  knlist klist;                   /* (a) list of knotes */
           ksiginfo_t lioj_ksi;                    /* (a) Realtime signal info */
   };
   
   #define LIOJ_SIGNAL             0x1     /* signal on all done (lio) */
   #define LIOJ_SIGNAL_POSTED      0x2     /* signal has been posted */
   #define LIOJ_KEVENT_POSTED      0x4     /* kevent triggered */
   
   /*
    * per process aio data structure
    */
   struct kaioinfo {
           struct  mtx kaio_mtx;           /* the lock to protect this struct */
           int     kaio_flags;             /* (a) per process kaio flags */
           int     kaio_active_count;      /* (c) number of currently used AIOs */
           int     kaio_count;             /* (a) size of AIO queue */
           int     kaio_buffer_count;      /* (a) number of bio buffers */
           TAILQ_HEAD(,kaiocb) kaio_all;   /* (a) all AIOs in a process */
           TAILQ_HEAD(,kaiocb) kaio_done;  /* (a) done queue for process */
           TAILQ_HEAD(,aioliojob) kaio_liojoblist; /* (a) list of lio jobs */
           TAILQ_HEAD(,kaiocb) kaio_jobqueue;      /* (a) job queue for process */
           TAILQ_HEAD(,kaiocb) kaio_syncqueue;     /* (a) queue for aio_fsync */
           TAILQ_HEAD(,kaiocb) kaio_syncready;  /* (a) second q for aio_fsync */
           struct  task kaio_task;         /* (*) task to kick aio processes */
           struct  task kaio_sync_task;    /* (*) task to schedule fsync jobs */
   };
   
   #define AIO_LOCK(ki)            mtx_lock(&(ki)->kaio_mtx)
   #define AIO_UNLOCK(ki)          mtx_unlock(&(ki)->kaio_mtx)
   #define AIO_LOCK_ASSERT(ki, f)  mtx_assert(&(ki)->kaio_mtx, (f))
   #define AIO_MTX(ki)             (&(ki)->kaio_mtx)
   
   #define KAIO_RUNDOWN    0x1     /* process is being run down */
   #define KAIO_WAKEUP     0x2     /* wakeup process when AIO completes */
   
   /*
    * Operations used to interact with userland aio control blocks.
    * Different ABIs provide their own operations.
    */
   struct aiocb_ops {
           int     (*copyin)(struct aiocb *ujob, struct aiocb *kjob);
           long    (*fetch_status)(struct aiocb *ujob);
           long    (*fetch_error)(struct aiocb *ujob);
           int     (*store_status)(struct aiocb *ujob, long status);
           int     (*store_error)(struct aiocb *ujob, long error);
           int     (*store_kernelinfo)(struct aiocb *ujob, long jobref);
           int     (*store_aiocb)(struct aiocb **ujobp, struct aiocb *ujob);
   };
   
   static TAILQ_HEAD(,aioproc) aio_freeproc;               /* (c) Idle daemons */
   static struct sema aio_newproc_sem;
   static struct mtx aio_job_mtx;
   static TAILQ_HEAD(,kaiocb) aio_jobs;                    /* (c) Async job list */
   static struct unrhdr *aiod_unr;
   
   void            aio_init_aioinfo(struct proc *p);
   static int      aio_onceonly(void);
   static int      aio_free_entry(struct kaiocb *job);
   static void     aio_process_rw(struct kaiocb *job);
   static void     aio_process_sync(struct kaiocb *job);
   static void     aio_process_mlock(struct kaiocb *job);
   static void     aio_schedule_fsync(void *context, int pending);
   static int      aio_newproc(int *);
   int             aio_aqueue(struct thread *td, struct aiocb *ujob,
                       struct aioliojob *lio, int type, struct aiocb_ops *ops);
   static int      aio_queue_file(struct file *fp, struct kaiocb *job);
   static void     aio_biowakeup(struct bio *bp);
   static void     aio_proc_rundown(void *arg, struct proc *p);
   static void     aio_proc_rundown_exec(void *arg, struct proc *p,
                       struct image_params *imgp);
   static int      aio_qbio(struct proc *p, struct kaiocb *job);
   static void     aio_daemon(void *param);
   static void     aio_bio_done_notify(struct proc *userp, struct kaiocb *job);
   static bool     aio_clear_cancel_function_locked(struct kaiocb *job);
   static int      aio_kick(struct proc *userp);
   static void     aio_kick_nowait(struct proc *userp);
   static void     aio_kick_helper(void *context, int pending);
   static int      filt_aioattach(struct knote *kn);
   static void     filt_aiodetach(struct knote *kn);
   static int      filt_aio(struct knote *kn, long hint);
   static int      filt_lioattach(struct knote *kn);
   static void     filt_liodetach(struct knote *kn);
   static int      filt_lio(struct knote *kn, long hint);
   
   /*
    * Zones for:
    *      kaio    Per process async io info
    *      aiop    async io process data
    *      aiocb   async io jobs
    *      aiolio  list io jobs
    */
   static uma_zone_t kaio_zone, aiop_zone, aiocb_zone, aiolio_zone;
   
   /* kqueue filters for aio */
   static struct filterops aio_filtops = {
           .f_isfd = 0,
           .f_attach = filt_aioattach,
           .f_detach = filt_aiodetach,
           .f_event = filt_aio,
   };
   static struct filterops lio_filtops = {
           .f_isfd = 0,
           .f_attach = filt_lioattach,
           .f_detach = filt_liodetach,
           .f_event = filt_lio
   };
   
   static eventhandler_tag exit_tag, exec_tag;
   
   TASKQUEUE_DEFINE_THREAD(aiod_kick);
   
   /*
    * Main operations function for use as a kernel module.
    */
   static int
   aio_modload(struct module *module, int cmd, void *arg)
   {
           int error = 0;
   
           switch (cmd) {
           case MOD_LOAD:
                   aio_onceonly();
                   break;
           case MOD_SHUTDOWN:
                   break;
           default:
                   error = EOPNOTSUPP;
                   break;
           }
           return (error);
   }
   
   static moduledata_t aio_mod = {
           "aio",
           &aio_modload,
           NULL
   };
   
   DECLARE_MODULE(aio, aio_mod, SI_SUB_VFS, SI_ORDER_ANY);
   MODULE_VERSION(aio, 1);
   
   /*
    * Startup initialization
    */
   static int
   aio_onceonly(void)
   {
   
           exit_tag = EVENTHANDLER_REGISTER(process_exit, aio_proc_rundown, NULL,
               EVENTHANDLER_PRI_ANY);
           exec_tag = EVENTHANDLER_REGISTER(process_exec, aio_proc_rundown_exec,
               NULL, EVENTHANDLER_PRI_ANY);
           kqueue_add_filteropts(EVFILT_AIO, &aio_filtops);
           kqueue_add_filteropts(EVFILT_LIO, &lio_filtops);
           TAILQ_INIT(&aio_freeproc);
           sema_init(&aio_newproc_sem, 0, "aio_new_proc");
           mtx_init(&aio_job_mtx, "aio_job", NULL, MTX_DEF);
           TAILQ_INIT(&aio_jobs);
           aiod_unr = new_unrhdr(1, INT_MAX, NULL);
           kaio_zone = uma_zcreate("AIO", sizeof(struct kaioinfo), NULL, NULL,
               NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
           aiop_zone = uma_zcreate("AIOP", sizeof(struct aioproc), NULL,
               NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
           aiocb_zone = uma_zcreate("AIOCB", sizeof(struct kaiocb), NULL, NULL,
               NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
           aiolio_zone = uma_zcreate("AIOLIO", sizeof(struct aioliojob), NULL,
               NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
           aiod_lifetime = AIOD_LIFETIME_DEFAULT;
           jobrefid = 1;
           p31b_setcfg(CTL_P1003_1B_ASYNCHRONOUS_IO, _POSIX_ASYNCHRONOUS_IO);
           p31b_setcfg(CTL_P1003_1B_AIO_MAX, MAX_AIO_QUEUE);
           p31b_setcfg(CTL_P1003_1B_AIO_PRIO_DELTA_MAX, 0);
   
           return (0);
   }
   
   /*
    * Init the per-process aioinfo structure.  The aioinfo limits are set
    * per-process for user limit (resource) management.
    */
   void
   aio_init_aioinfo(struct proc *p)
   {
           struct kaioinfo *ki;
   
           ki = uma_zalloc(kaio_zone, M_WAITOK);
           mtx_init(&ki->kaio_mtx, "aiomtx", NULL, MTX_DEF | MTX_NEW);
           ki->kaio_flags = 0;
           ki->kaio_active_count = 0;
           ki->kaio_count = 0;
           ki->kaio_buffer_count = 0;
           TAILQ_INIT(&ki->kaio_all);
           TAILQ_INIT(&ki->kaio_done);
           TAILQ_INIT(&ki->kaio_jobqueue);
           TAILQ_INIT(&ki->kaio_liojoblist);
           TAILQ_INIT(&ki->kaio_syncqueue);
           TAILQ_INIT(&ki->kaio_syncready);
           TASK_INIT(&ki->kaio_task, 0, aio_kick_helper, p);
           TASK_INIT(&ki->kaio_sync_task, 0, aio_schedule_fsync, ki);
           PROC_LOCK(p);
           if (p->p_aioinfo == NULL) {
                   p->p_aioinfo = ki;
                   PROC_UNLOCK(p);
           } else {
                   PROC_UNLOCK(p);
                   mtx_destroy(&ki->kaio_mtx);
                   uma_zfree(kaio_zone, ki);
           }
   
           while (num_aio_procs < MIN(target_aio_procs, max_aio_procs))
                   aio_newproc(NULL);
   }
   
   static int
   aio_sendsig(struct proc *p, struct sigevent *sigev, ksiginfo_t *ksi)
   {
           struct thread *td;
           int error;
   
           error = sigev_findtd(p, sigev, &td);
           if (error)
                   return (error);
           if (!KSI_ONQ(ksi)) {
                   ksiginfo_set_sigev(ksi, sigev);
                   ksi->ksi_code = SI_ASYNCIO;
                   ksi->ksi_flags |= KSI_EXT | KSI_INS;
                   tdsendsignal(p, td, ksi->ksi_signo, ksi);
           }
           PROC_UNLOCK(p);
           return (error);
   }
   
   /*
    * Free a job entry.  Wait for completion if it is currently active, but don't
    * delay forever.  If we delay, we return a flag that says that we have to
    * restart the queue scan.
    */
   static int
   aio_free_entry(struct kaiocb *job)
   {
           struct kaioinfo *ki;
           struct aioliojob *lj;
           struct proc *p;
   
           p = job->userproc;
           MPASS(curproc == p);
           ki = p->p_aioinfo;
           MPASS(ki != NULL);
   
           AIO_LOCK_ASSERT(ki, MA_OWNED);
           MPASS(job->jobflags & KAIOCB_FINISHED);
   
           atomic_subtract_int(&num_queue_count, 1);
   
           ki->kaio_count--;
           MPASS(ki->kaio_count >= 0);
   
           TAILQ_REMOVE(&ki->kaio_done, job, plist);
           TAILQ_REMOVE(&ki->kaio_all, job, allist);
   
           lj = job->lio;
           if (lj) {
                   lj->lioj_count--;
                   lj->lioj_finished_count--;
   
                   if (lj->lioj_count == 0) {
                           TAILQ_REMOVE(&ki->kaio_liojoblist, lj, lioj_list);
                           /* lio is going away, we need to destroy any knotes */
                           knlist_delete(&lj->klist, curthread, 1);
                           PROC_LOCK(p);
                           sigqueue_take(&lj->lioj_ksi);
                           PROC_UNLOCK(p);
                           uma_zfree(aiolio_zone, lj);
                   }
           }
   
           /* job is going away, we need to destroy any knotes */
           knlist_delete(&job->klist, curthread, 1);
           PROC_LOCK(p);
           sigqueue_take(&job->ksi);
           PROC_UNLOCK(p);
   
           AIO_UNLOCK(ki);
   
           /*
            * The thread argument here is used to find the owning process
            * and is also passed to fo_close() which may pass it to various
            * places such as devsw close() routines.  Because of that, we
            * need a thread pointer from the process owning the job that is
            * persistent and won't disappear out from under us or move to
            * another process.
            *
            * Currently, all the callers of this function call it to remove
            * a kaiocb from the current process' job list either via a
            * syscall or due to the current process calling exit() or
            * execve().  Thus, we know that p == curproc.  We also know that
            * curthread can't exit since we are curthread.
            *
            * Therefore, we use curthread as the thread to pass to
            * knlist_delete().  This does mean that it is possible for the
            * thread pointer at close time to differ from the thread pointer
            * at open time, but this is already true of file descriptors in
            * a multithreaded process.
            */
           if (job->fd_file)
                   fdrop(job->fd_file, curthread);
           crfree(job->cred);
           uma_zfree(aiocb_zone, job);
           AIO_LOCK(ki);
   
           return (0);
   }
   
   static void
   aio_proc_rundown_exec(void *arg, struct proc *p,
       struct image_params *imgp __unused)
   {
           aio_proc_rundown(arg, p);
   }
   
   static int
   aio_cancel_job(struct proc *p, struct kaioinfo *ki, struct kaiocb *job)
   {
           aio_cancel_fn_t *func;
           int cancelled;
   
           AIO_LOCK_ASSERT(ki, MA_OWNED);
           if (job->jobflags & (KAIOCB_CANCELLED | KAIOCB_FINISHED))
                   return (0);
           MPASS((job->jobflags & KAIOCB_CANCELLING) == 0);
           job->jobflags |= KAIOCB_CANCELLED;
   
           func = job->cancel_fn;
   
           /*
            * If there is no cancel routine, just leave the job marked as
            * cancelled.  The job should be in active use by a caller who
            * should complete it normally or when it fails to install a
            * cancel routine.
            */
           if (func == NULL)
                   return (0);
   
           /*
            * Set the CANCELLING flag so that aio_complete() will defer
            * completions of this job.  This prevents the job from being
            * freed out from under the cancel callback.  After the
            * callback any deferred completion (whether from the callback
            * or any other source) will be completed.
            */
           job->jobflags |= KAIOCB_CANCELLING;
           AIO_UNLOCK(ki);
           func(job);
           AIO_LOCK(ki);
           job->jobflags &= ~KAIOCB_CANCELLING;
           if (job->jobflags & KAIOCB_FINISHED) {
                   cancelled = job->uaiocb._aiocb_private.error == ECANCELED;
                   TAILQ_REMOVE(&ki->kaio_jobqueue, job, plist);
                   aio_bio_done_notify(p, job);
           } else {
                   /*
                    * The cancel callback might have scheduled an
                    * operation to cancel this request, but it is
                    * only counted as cancelled if the request is
                    * cancelled when the callback returns.
                    */
                   cancelled = 0;
           }
           return (cancelled);
   }
   
   /*
    * Rundown the jobs for a given process.
    */
   static void
   aio_proc_rundown(void *arg, struct proc *p)
   {
           struct kaioinfo *ki;
           struct aioliojob *lj;
           struct kaiocb *job, *jobn;
   
           KASSERT(curthread->td_proc == p,
               ("%s: called on non-curproc", __func__));
           ki = p->p_aioinfo;
           if (ki == NULL)
                   return;
   
           AIO_LOCK(ki);
           ki->kaio_flags |= KAIO_RUNDOWN;
   
   restart:
   
           /*
            * Try to cancel all pending requests. This code simulates
            * aio_cancel on all pending I/O requests.
            */
           TAILQ_FOREACH_SAFE(job, &ki->kaio_jobqueue, plist, jobn) {
                   aio_cancel_job(p, ki, job);
           }
   
           /* Wait for all running I/O to be finished */
           if (TAILQ_FIRST(&ki->kaio_jobqueue) || ki->kaio_active_count != 0) {
                   ki->kaio_flags |= KAIO_WAKEUP;
                   msleep(&p->p_aioinfo, AIO_MTX(ki), PRIBIO, "aioprn", hz);
                   goto restart;
           }
   
           /* Free all completed I/O requests. */
           while ((job = TAILQ_FIRST(&ki->kaio_done)) != NULL)
                   aio_free_entry(job);
   
           while ((lj = TAILQ_FIRST(&ki->kaio_liojoblist)) != NULL) {
                   if (lj->lioj_count == 0) {
                           TAILQ_REMOVE(&ki->kaio_liojoblist, lj, lioj_list);
                           knlist_delete(&lj->klist, curthread, 1);
                           PROC_LOCK(p);
                           sigqueue_take(&lj->lioj_ksi);
                           PROC_UNLOCK(p);
                           uma_zfree(aiolio_zone, lj);
                   } else {
                           panic("LIO job not cleaned up: C:%d, FC:%d\n",
                               lj->lioj_count, lj->lioj_finished_count);
                   }
           }
           AIO_UNLOCK(ki);
           taskqueue_drain(taskqueue_aiod_kick, &ki->kaio_task);
           taskqueue_drain(taskqueue_aiod_kick, &ki->kaio_sync_task);
           mtx_destroy(&ki->kaio_mtx);
           uma_zfree(kaio_zone, ki);
           p->p_aioinfo = NULL;
   }
   
   /*
    * Select a job to run (called by an AIO daemon).
    */
   static struct kaiocb *
   aio_selectjob(struct aioproc *aiop)
   {
           struct kaiocb *job;
           struct kaioinfo *ki;
           struct proc *userp;
   
           mtx_assert(&aio_job_mtx, MA_OWNED);
   restart:
           TAILQ_FOREACH(job, &aio_jobs, list) {
                   userp = job->userproc;
                   ki = userp->p_aioinfo;
   
                   if (ki->kaio_active_count < max_aio_per_proc) {
                           TAILQ_REMOVE(&aio_jobs, job, list);
                           if (!aio_clear_cancel_function(job))
                                   goto restart;
   
                           /* Account for currently active jobs. */
                           ki->kaio_active_count++;
                           break;
                   }
           }
           return (job);
   }
   
   /*
    * Move all data to a permanent storage device.  This code
    * simulates the fsync syscall.
    */
   static int
   aio_fsync_vnode(struct thread *td, struct vnode *vp)
   {
           struct mount *mp;
           int error;
   
           if ((error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0)
                   goto drop;
           vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
           if (vp->v_object != NULL) {
                   VM_OBJECT_WLOCK(vp->v_object);
                   vm_object_page_clean(vp->v_object, 0, 0, 0);
                   VM_OBJECT_WUNLOCK(vp->v_object);
           }
           error = VOP_FSYNC(vp, MNT_WAIT, td);
   
           VOP_UNLOCK(vp, 0);
           vn_finished_write(mp);
   drop:
           return (error);
   }
   
   /*
    * The AIO processing activity for LIO_READ/LIO_WRITE.  This is the code that
    * does the I/O request for the non-bio version of the operations.  The normal
    * vn operations are used, and this code should work in all instances for every
    * type of file, including pipes, sockets, fifos, and regular files.
    *
    * XXX I don't think it works well for socket, pipe, and fifo.
    */
   static void
   aio_process_rw(struct kaiocb *job)
   {
           struct ucred *td_savedcred;
           struct thread *td;
           struct aiocb *cb;
           struct file *fp;
           struct uio auio;
           struct iovec aiov;
           ssize_t cnt;
           long msgsnd_st, msgsnd_end;
           long msgrcv_st, msgrcv_end;
           long oublock_st, oublock_end;
           long inblock_st, inblock_end;
           int error;
   
           KASSERT(job->uaiocb.aio_lio_opcode == LIO_READ ||
               job->uaiocb.aio_lio_opcode == LIO_WRITE,
               ("%s: opcode %d", __func__, job->uaiocb.aio_lio_opcode));
   
           aio_switch_vmspace(job);
           td = curthread;
           td_savedcred = td->td_ucred;
           td->td_ucred = job->cred;
           cb = &job->uaiocb;
           fp = job->fd_file;
   
           aiov.iov_base = (void *)(uintptr_t)cb->aio_buf;
           aiov.iov_len = cb->aio_nbytes;
   
           auio.uio_iov = &aiov;
           auio.uio_iovcnt = 1;
           auio.uio_offset = cb->aio_offset;
           auio.uio_resid = cb->aio_nbytes;
           cnt = cb->aio_nbytes;
           auio.uio_segflg = UIO_USERSPACE;
           auio.uio_td = td;
   
           msgrcv_st = td->td_ru.ru_msgrcv;
           msgsnd_st = td->td_ru.ru_msgsnd;
           inblock_st = td->td_ru.ru_inblock;
           oublock_st = td->td_ru.ru_oublock;
   
           /*
            * aio_aqueue() acquires a reference to the file that is
            * released in aio_free_entry().
            */
           if (cb->aio_lio_opcode == LIO_READ) {
                   auio.uio_rw = UIO_READ;
                   if (auio.uio_resid == 0)
                           error = 0;
                   else
                           error = fo_read(fp, &auio, fp->f_cred, FOF_OFFSET, td);
           } else {
                   if (fp->f_type == DTYPE_VNODE)
                           bwillwrite();
                   auio.uio_rw = UIO_WRITE;
                   error = fo_write(fp, &auio, fp->f_cred, FOF_OFFSET, td);
           }
           msgrcv_end = td->td_ru.ru_msgrcv;
           msgsnd_end = td->td_ru.ru_msgsnd;
           inblock_end = td->td_ru.ru_inblock;
           oublock_end = td->td_ru.ru_oublock;
   
           job->msgrcv = msgrcv_end - msgrcv_st;
           job->msgsnd = msgsnd_end - msgsnd_st;
           job->inblock = inblock_end - inblock_st;
           job->outblock = oublock_end - oublock_st;
   
           if ((error) && (auio.uio_resid != cnt)) {
                   if (error == ERESTART || error == EINTR || error == EWOULDBLOCK)
                           error = 0;
                   if ((error == EPIPE) && (cb->aio_lio_opcode == LIO_WRITE)) {
                           PROC_LOCK(job->userproc);
                           kern_psignal(job->userproc, SIGPIPE);
                           PROC_UNLOCK(job->userproc);
                   }
           }
   
           cnt -= auio.uio_resid;
           td->td_ucred = td_savedcred;
           if (error)
                   aio_complete(job, -1, error);
           else
                   aio_complete(job, cnt, 0);
   }
   
   static void
   aio_process_sync(struct kaiocb *job)
   {
           struct thread *td = curthread;
           struct ucred *td_savedcred = td->td_ucred;
           struct file *fp = job->fd_file;
           int error = 0;
   
           KASSERT(job->uaiocb.aio_lio_opcode == LIO_SYNC,
               ("%s: opcode %d", __func__, job->uaiocb.aio_lio_opcode));
   
           td->td_ucred = job->cred;
           if (fp->f_vnode != NULL)
                   error = aio_fsync_vnode(td, fp->f_vnode);
           td->td_ucred = td_savedcred;
           if (error)
                   aio_complete(job, -1, error);
           else
                   aio_complete(job, 0, 0);
   }
   
   static void
   aio_process_mlock(struct kaiocb *job)
   {
           struct aiocb *cb = &job->uaiocb;
           int error;
   
           KASSERT(job->uaiocb.aio_lio_opcode == LIO_MLOCK,
               ("%s: opcode %d", __func__, job->uaiocb.aio_lio_opcode));
   
           aio_switch_vmspace(job);
           error = kern_mlock(job->userproc, job->cred,
               __DEVOLATILE(uintptr_t, cb->aio_buf), cb->aio_nbytes);
           aio_complete(job, error != 0 ? -1 : 0, error);
   }
   
   static void
   aio_bio_done_notify(struct proc *userp, struct kaiocb *job)
   {
           struct aioliojob *lj;
           struct kaioinfo *ki;
           struct kaiocb *sjob, *sjobn;
           int lj_done;
           bool schedule_fsync;
   
           ki = userp->p_aioinfo;
           AIO_LOCK_ASSERT(ki, MA_OWNED);
           lj = job->lio;
           lj_done = 0;
           if (lj) {
                   lj->lioj_finished_count++;
                   if (lj->lioj_count == lj->lioj_finished_count)
                           lj_done = 1;
           }
           TAILQ_INSERT_TAIL(&ki->kaio_done, job, plist);
           MPASS(job->jobflags & KAIOCB_FINISHED);
   
           if (ki->kaio_flags & KAIO_RUNDOWN)
                   goto notification_done;
   
           if (job->uaiocb.aio_sigevent.sigev_notify == SIGEV_SIGNAL ||
               job->uaiocb.aio_sigevent.sigev_notify == SIGEV_THREAD_ID)
                   aio_sendsig(userp, &job->uaiocb.aio_sigevent, &job->ksi);
   
           KNOTE_LOCKED(&job->klist, 1);
   
           if (lj_done) {
                   if (lj->lioj_signal.sigev_notify == SIGEV_KEVENT) {
                           lj->lioj_flags |= LIOJ_KEVENT_POSTED;
                           KNOTE_LOCKED(&lj->klist, 1);
                   }
                   if ((lj->lioj_flags & (LIOJ_SIGNAL|LIOJ_SIGNAL_POSTED))
                       == LIOJ_SIGNAL
                       && (lj->lioj_signal.sigev_notify == SIGEV_SIGNAL ||
                           lj->lioj_signal.sigev_notify == SIGEV_THREAD_ID)) {
                           aio_sendsig(userp, &lj->lioj_signal, &lj->lioj_ksi);
                           lj->lioj_flags |= LIOJ_SIGNAL_POSTED;
                   }
           }
   
   notification_done:
           if (job->jobflags & KAIOCB_CHECKSYNC) {
                   schedule_fsync = false;
                   TAILQ_FOREACH_SAFE(sjob, &ki->kaio_syncqueue, list, sjobn) {
                           if (job->fd_file != sjob->fd_file ||
                               job->seqno >= sjob->seqno)
                                   continue;
                           if (--sjob->pending > 0)
                                   continue;
                           TAILQ_REMOVE(&ki->kaio_syncqueue, sjob, list);
                           if (!aio_clear_cancel_function_locked(sjob))
                                   continue;
                           TAILQ_INSERT_TAIL(&ki->kaio_syncready, sjob, list);
                           schedule_fsync = true;
                   }
                   if (schedule_fsync)
                           taskqueue_enqueue(taskqueue_aiod_kick,
                               &ki->kaio_sync_task);
           }
           if (ki->kaio_flags & KAIO_WAKEUP) {
                   ki->kaio_flags &= ~KAIO_WAKEUP;
                   wakeup(&userp->p_aioinfo);
           }
   }
   
   static void
   aio_schedule_fsync(void *context, int pending)
   {
           struct kaioinfo *ki;
           struct kaiocb *job;
   
           ki = context;
           AIO_LOCK(ki);
           while (!TAILQ_EMPTY(&ki->kaio_syncready)) {
                   job = TAILQ_FIRST(&ki->kaio_syncready);
                   TAILQ_REMOVE(&ki->kaio_syncready, job, list);
                   AIO_UNLOCK(ki);
                   aio_schedule(job, aio_process_sync);
                   AIO_LOCK(ki);
           }
           AIO_UNLOCK(ki);
   }
   
   bool
   aio_cancel_cleared(struct kaiocb *job)
   {
           struct kaioinfo *ki;
   
           /*
            * The caller should hold the same queue lock held when
            * aio_clear_cancel_function() was called and set this flag
            * ensuring this check sees an up-to-date value.  However,
            * there is no way to assert that.
            */
           ki = job->userproc->p_aioinfo;
           return ((job->jobflags & KAIOCB_CLEARED) != 0);
   }
   
   static bool
   aio_clear_cancel_function_locked(struct kaiocb *job)
   {
   
           AIO_LOCK_ASSERT(job->userproc->p_aioinfo, MA_OWNED);
           MPASS(job->cancel_fn != NULL);
           if (job->jobflags & KAIOCB_CANCELLING) {
                   job->jobflags |= KAIOCB_CLEARED;
                   return (false);
           }
           job->cancel_fn = NULL;
           return (true);
   }
   
   bool
   aio_clear_cancel_function(struct kaiocb *job)
   {
           struct kaioinfo *ki;
           bool ret;
   
           ki = job->userproc->p_aioinfo;
           AIO_LOCK(ki);
           ret = aio_clear_cancel_function_locked(job);
           AIO_UNLOCK(ki);
           return (ret);
  }
  
  static bool
  aio_set_cancel_function_locked(struct kaiocb *job, aio_cancel_fn_t *func)
  {
  
          AIO_LOCK_ASSERT(job->userproc->p_aioinfo, MA_OWNED);
          if (job->jobflags & KAIOCB_CANCELLED)
                  return (false);
          job->cancel_fn = func;
          return (true);
  }
  
  bool
  aio_set_cancel_function(struct kaiocb *job, aio_cancel_fn_t *func)
  {
          struct kaioinfo *ki;
          bool ret;
  
          ki = job->userproc->p_aioinfo;
          AIO_LOCK(ki);
          ret = aio_set_cancel_function_locked(job, func);
          AIO_UNLOCK(ki);
          return (ret);
  }
  
  void
  aio_complete(struct kaiocb *job, long status, int error)
  {
          struct kaioinfo *ki;
          struct proc *userp;
  
          job->uaiocb._aiocb_private.error = error;
          job->uaiocb._aiocb_private.status = status;
  
          userp = job->userproc;
          ki = userp->p_aioinfo;
  
          AIO_LOCK(ki);
          KASSERT(!(job->jobflags & KAIOCB_FINISHED),
              ("duplicate aio_complete"));
          job->jobflags |= KAIOCB_FINISHED;
          if ((job->jobflags & (KAIOCB_QUEUEING | KAIOCB_CANCELLING)) == 0) {
                  TAILQ_REMOVE(&ki->kaio_jobqueue, job, plist);
                  aio_bio_done_notify(userp, job);
          }
          AIO_UNLOCK(ki);
  }
  
  void
  aio_cancel(struct kaiocb *job)
  {
  
          aio_complete(job, -1, ECANCELED);
  }
  
  void
  aio_switch_vmspace(struct kaiocb *job)
  {
  
          vmspace_switch_aio(job->userproc->p_vmspace);
  }
  
  /*
   * The AIO daemon, most of the actual work is done in aio_process_*,
   * but the setup (and address space mgmt) is done in this routine.
   */
  static void
  aio_daemon(void *_id)
  {
          struct kaiocb *job;
          struct aioproc *aiop;
          struct kaioinfo *ki;
          struct proc *p;
          struct vmspace *myvm;
          struct thread *td = curthread;
          int id = (intptr_t)_id;
  
          /*
           * Grab an extra reference on the daemon's vmspace so that it
           * doesn't get freed by jobs that switch to a different
           * vmspace.
           */
          p = td->td_proc;
          myvm = vmspace_acquire_ref(p);
  
          KASSERT(p->p_textvp == NULL, ("kthread has a textvp"));
  
          /*
           * Allocate and ready the aio control info.  There is one aiop structure
           * per daemon.
           */
          aiop = uma_zalloc(aiop_zone, M_WAITOK);
          aiop->aioproc = p;
          aiop->aioprocflags = 0;
  
          /*
           * Wakeup parent process.  (Parent sleeps to keep from blasting away
           * and creating too many daemons.)
           */
          sema_post(&aio_newproc_sem);
  
          mtx_lock(&aio_job_mtx);
          for (;;) {
                  /*
                   * Take daemon off of free queue
                   */
                  if (aiop->aioprocflags & AIOP_FREE) {
                          TAILQ_REMOVE(&aio_freeproc, aiop, list);
                          aiop->aioprocflags &= ~AIOP_FREE;
                  }
  
                  /*
                   * Check for jobs.
                   */
                  while ((job = aio_selectjob(aiop)) != NULL) {
                          mtx_unlock(&aio_job_mtx);
  
                          ki = job->userproc->p_aioinfo;
                          job->handle_fn(job);
  
                          mtx_lock(&aio_job_mtx);
                          /* Decrement the active job count. */
                          ki->kaio_active_count--;
                  }
  
                  /*
                   * Disconnect from user address space.
                   */
                  if (p->p_vmspace != myvm) {
                          mtx_unlock(&aio_job_mtx);
                          vmspace_switch_aio(myvm);
                          mtx_lock(&aio_job_mtx);
                          /*
                           * We have to restart to avoid race, we only sleep if
                           * no job can be selected.
                           */
                          continue;
                  }
  
                  mtx_assert(&aio_job_mtx, MA_OWNED);
  
                  TAILQ_INSERT_HEAD(&aio_freeproc, aiop, list);
                  aiop->aioprocflags |= AIOP_FREE;
  
                  /*
                   * If daemon is inactive for a long time, allow it to exit,
                   * thereby freeing resources.
                   */
                  if (msleep(p, &aio_job_mtx, PRIBIO, "aiordy",
                      aiod_lifetime) == EWOULDBLOCK && TAILQ_EMPTY(&aio_jobs) &&
                      (aiop->aioprocflags & AIOP_FREE) &&
                      num_aio_procs > target_aio_procs)
                          break;
          }
          TAILQ_REMOVE(&aio_freeproc, aiop, list);
          num_aio_procs--;
          mtx_unlock(&aio_job_mtx);
          uma_zfree(aiop_zone, aiop);
          free_unr(aiod_unr, id);
          vmspace_free(myvm);
  
          KASSERT(p->p_vmspace == myvm,
              ("AIOD: bad vmspace for exiting daemon"));
          KASSERT(myvm->vm_refcnt > 1,
              ("AIOD: bad vm refcnt for exiting daemon: %d", myvm->vm_refcnt));
          kproc_exit(0);
  }
  
  /*
   * Create a new AIO daemon. This is mostly a kernel-thread fork routine. The
   * AIO daemon modifies its environment itself.
   */
  static int
  aio_newproc(int *start)
  {
          int error;
          struct proc *p;
          int id;
  
          id = alloc_unr(aiod_unr);
          error = kproc_create(aio_daemon, (void *)(intptr_t)id, &p,
                  RFNOWAIT, 0, "aiod%d", id);
          if (error == 0) {
                  /*
                   * Wait until daemon is started.
                   */
                  sema_wait(&aio_newproc_sem);
                  mtx_lock(&aio_job_mtx);
                  num_aio_procs++;
                  if (start != NULL)
                          (*start)--;
                  mtx_unlock(&aio_job_mtx);
          } else {
                  free_unr(aiod_unr, id);
          }
          return (error);
  }
  
  /*
   * Try the high-performance, low-overhead bio method for eligible
   * VCHR devices.  This method doesn't use an aio helper thread, and
   * thus has very low overhead.
   *
   * Assumes that the caller, aio_aqueue(), has incremented the file
   * structure's reference count, preventing its deallocation for the
   * duration of this call.
   */
  static int
  aio_qbio(struct proc *p, struct kaiocb *job)
  {
          struct aiocb *cb;
          struct file *fp;
          struct bio *bp;
          struct buf *pbuf;
          struct vnode *vp;
          struct cdevsw *csw;
          struct cdev *dev;
          struct kaioinfo *ki;
          int error, ref, poff;
          vm_prot_t prot;
  
          cb = &job->uaiocb;
          fp = job->fd_file;
  
          if (!(cb->aio_lio_opcode == LIO_WRITE ||
              cb->aio_lio_opcode == LIO_READ))
                  return (-1);
          if (fp == NULL || fp->f_type != DTYPE_VNODE)
                  return (-1);
  
          vp = fp->f_vnode;
          if (vp->v_type != VCHR)
                  return (-1);
          if (vp->v_bufobj.bo_bsize == 0)
                  return (-1);
          if (cb->aio_nbytes % vp->v_bufobj.bo_bsize)
                  return (-1);
  
          ref = 0;
          csw = devvn_refthread(vp, &dev, &ref);
          if (csw == NULL)
                  return (ENXIO);
  
          if ((csw->d_flags & D_DISK) == 0) {
                  error = -1;
                  goto unref;
          }
          if (cb->aio_nbytes > dev->si_iosize_max) {
                  error = -1;
                  goto unref;
          }
  
          ki = p->p_aioinfo;
          poff = (vm_offset_t)cb->aio_buf & PAGE_MASK;
          if ((dev->si_flags & SI_UNMAPPED) && unmapped_buf_allowed) {
                  if (cb->aio_nbytes > MAXPHYS) {
                          error = -1;
                          goto unref;
                  }
  
                  pbuf = NULL;
          } else {
                  if (cb->aio_nbytes > MAXPHYS - poff) {
                          error = -1;
                          goto unref;
                  }
                  if (ki->kaio_buffer_count >= max_buf_aio) {
                          error = EAGAIN;
                          goto unref;
                  }
  
                  job->pbuf = pbuf = (struct buf *)getpbuf(NULL);
                  BUF_KERNPROC(pbuf);
                  AIO_LOCK(ki);
                  ki->kaio_buffer_count++;
                  AIO_UNLOCK(ki);
          }
          job->bp = bp = g_alloc_bio();
  
          bp->bio_length = cb->aio_nbytes;
          bp->bio_bcount = cb->aio_nbytes;
          bp->bio_done = aio_biowakeup;
          bp->bio_offset = cb->aio_offset;
          bp->bio_cmd = cb->aio_lio_opcode == LIO_WRITE ? BIO_WRITE : BIO_READ;
          bp->bio_dev = dev;
          bp->bio_caller1 = (void *)job;
  
          prot = VM_PROT_READ;
          if (cb->aio_lio_opcode == LIO_READ)
                  prot |= VM_PROT_WRITE;  /* Less backwards than it looks */
          job->npages = vm_fault_quick_hold_pages(&curproc->p_vmspace->vm_map,
              (vm_offset_t)cb->aio_buf, bp->bio_length, prot, job->pages,
              nitems(job->pages));
          if (job->npages < 0) {
                  error = EFAULT;
                  goto doerror;
          }
          if (pbuf != NULL) {
                  pmap_qenter((vm_offset_t)pbuf->b_data,
                      job->pages, job->npages);
                  bp->bio_data = pbuf->b_data + poff;
                  atomic_add_int(&num_buf_aio, 1);
          } else {
                  bp->bio_ma = job->pages;
                  bp->bio_ma_n = job->npages;
                  bp->bio_ma_offset = poff;
                  bp->bio_data = unmapped_buf;
                  bp->bio_flags |= BIO_UNMAPPED;
                  atomic_add_int(&num_unmapped_aio, 1);
          }
  
          /* Perform transfer. */
          csw->d_strategy(bp);
          dev_relthread(dev, ref);
          return (0);
  
  doerror:
          if (pbuf != NULL) {
                  AIO_LOCK(ki);
                  ki->kaio_buffer_count--;
                  AIO_UNLOCK(ki);
                  relpbuf(pbuf, NULL);
                  job->pbuf = NULL;
          }
          g_destroy_bio(bp);
          job->bp = NULL;
  unref:
          dev_relthread(dev, ref);
          return (error);
  }
  
  #ifdef COMPAT_FREEBSD6
  static int
  convert_old_sigevent(struct osigevent *osig, struct sigevent *nsig)
  {
  
          /*
           * Only SIGEV_NONE, SIGEV_SIGNAL, and SIGEV_KEVENT are
           * supported by AIO with the old sigevent structure.
           */
          nsig->sigev_notify = osig->sigev_notify;
          switch (nsig->sigev_notify) {
          case SIGEV_NONE:
                  break;
          case SIGEV_SIGNAL:
                  nsig->sigev_signo = osig->__sigev_u.__sigev_signo;
                  break;
          case SIGEV_KEVENT:
                  nsig->sigev_notify_kqueue =
                      osig->__sigev_u.__sigev_notify_kqueue;
                  nsig->sigev_value.sival_ptr = osig->sigev_value.sival_ptr;
                  break;
          default:
                  return (EINVAL);
          }
          return (0);
  }
  
  static int
  aiocb_copyin_old_sigevent(struct aiocb *ujob, struct aiocb *kjob)
  {
          struct oaiocb *ojob;
          int error;
  
          bzero(kjob, sizeof(struct aiocb));
          error = copyin(ujob, kjob, sizeof(struct oaiocb));
          if (error)
                  return (error);
          ojob = (struct oaiocb *)kjob;
          return (convert_old_sigevent(&ojob->aio_sigevent, &kjob->aio_sigevent));
  }
  #endif
  
  static int
  aiocb_copyin(struct aiocb *ujob, struct aiocb *kjob)
  {
  
          return (copyin(ujob, kjob, sizeof(struct aiocb)));
  }
  
  static long
  aiocb_fetch_status(struct aiocb *ujob)
  {
  
          return (fuword(&ujob->_aiocb_private.status));
  }
  
  static long
  aiocb_fetch_error(struct aiocb *ujob)
  {
  
          return (fuword(&ujob->_aiocb_private.error));
  }
  
  static int
  aiocb_store_status(struct aiocb *ujob, long status)
  {
  
          return (suword(&ujob->_aiocb_private.status, status));
  }
  
  static int
  aiocb_store_error(struct aiocb *ujob, long error)
  {
  
          return (suword(&ujob->_aiocb_private.error, error));
  }
  
  static int
  aiocb_store_kernelinfo(struct aiocb *ujob, long jobref)
  {
  
          return (suword(&ujob->_aiocb_private.kernelinfo, jobref));
  }
  
  static int
  aiocb_store_aiocb(struct aiocb **ujobp, struct aiocb *ujob)
  {
  
          return (suword(ujobp, (long)ujob));
  }
  
  static struct aiocb_ops aiocb_ops = {
          .copyin = aiocb_copyin,
          .fetch_status = aiocb_fetch_status,
          .fetch_error = aiocb_fetch_error,
          .store_status = aiocb_store_status,
          .store_error = aiocb_store_error,
          .store_kernelinfo = aiocb_store_kernelinfo,
          .store_aiocb = aiocb_store_aiocb,
  };
  
  #ifdef COMPAT_FREEBSD6
  static struct aiocb_ops aiocb_ops_osigevent = {
          .copyin = aiocb_copyin_old_sigevent,
          .fetch_status = aiocb_fetch_status,
          .fetch_error = aiocb_fetch_error,
          .store_status = aiocb_store_status,
          .store_error = aiocb_store_error,
          .store_kernelinfo = aiocb_store_kernelinfo,
          .store_aiocb = aiocb_store_aiocb,
  };
  #endif
  
  /*
   * Queue a new AIO request.  Choosing either the threaded or direct bio VCHR
   * technique is done in this code.
   */
  int
  aio_aqueue(struct thread *td, struct aiocb *ujob, struct aioliojob *lj,
      int type, struct aiocb_ops *ops)
  {
          struct proc *p = td->td_proc;
          cap_rights_t rights;
          struct file *fp;
          struct kaiocb *job;
          struct kaioinfo *ki;
          struct kevent kev;
          int opcode;
          int error;
          int fd, kqfd;
          int jid;
          u_short evflags;
  
          if (p->p_aioinfo == NULL)
                  aio_init_aioinfo(p);
  
          ki = p->p_aioinfo;
  
          ops->store_status(ujob, -1);
          ops->store_error(ujob, 0);
          ops->store_kernelinfo(ujob, -1);
  
          if (num_queue_count >= max_queue_count ||
              ki->kaio_count >= max_aio_queue_per_proc) {
                  ops->store_error(ujob, EAGAIN);
                  return (EAGAIN);
          }
  
          job = uma_zalloc(aiocb_zone, M_WAITOK | M_ZERO);
          knlist_init_mtx(&job->klist, AIO_MTX(ki));
  
          error = ops->copyin(ujob, &job->uaiocb);
          if (error) {
                  ops->store_error(ujob, error);
                  uma_zfree(aiocb_zone, job);
                  return (error);
          }
  
          if (job->uaiocb.aio_nbytes > IOSIZE_MAX) {
                  uma_zfree(aiocb_zone, job);
                  return (EINVAL);
          }
  
          if (job->uaiocb.aio_sigevent.sigev_notify != SIGEV_KEVENT &&
              job->uaiocb.aio_sigevent.sigev_notify != SIGEV_SIGNAL &&
              job->uaiocb.aio_sigevent.sigev_notify != SIGEV_THREAD_ID &&
              job->uaiocb.aio_sigevent.sigev_notify != SIGEV_NONE) {
                  ops->store_error(ujob, EINVAL);
                  uma_zfree(aiocb_zone, job);
                  return (EINVAL);
          }
  
          if ((job->uaiocb.aio_sigevent.sigev_notify == SIGEV_SIGNAL ||
               job->uaiocb.aio_sigevent.sigev_notify == SIGEV_THREAD_ID) &&
                  !_SIG_VALID(job->uaiocb.aio_sigevent.sigev_signo)) {
                  uma_zfree(aiocb_zone, job);
                  return (EINVAL);
          }
  
          ksiginfo_init(&job->ksi);
  
          /* Save userspace address of the job info. */
          job->ujob = ujob;
  
          /* Get the opcode. */
          if (type != LIO_NOP)
                  job->uaiocb.aio_lio_opcode = type;
          opcode = job->uaiocb.aio_lio_opcode;
  
          /*
           * Validate the opcode and fetch the file object for the specified
           * file descriptor.
           *
           * XXXRW: Moved the opcode validation up here so that we don't
           * retrieve a file descriptor without knowing what the capabiltity
           * should be.
           */
          fd = job->uaiocb.aio_fildes;
          switch (opcode) {
          case LIO_WRITE:
                  error = fget_write(td, fd,
                      cap_rights_init(&rights, CAP_PWRITE), &fp);
                  break;
          case LIO_READ:
                  error = fget_read(td, fd,
                      cap_rights_init(&rights, CAP_PREAD), &fp);
                  break;
          case LIO_SYNC:
                  error = fget(td, fd, cap_rights_init(&rights, CAP_FSYNC), &fp);
                  break;
          case LIO_MLOCK:
                  fp = NULL;
                  break;
          case LIO_NOP:
                  error = fget(td, fd, cap_rights_init(&rights), &fp);
                  break;
          default:
                  error = EINVAL;
          }
          if (error) {
                  uma_zfree(aiocb_zone, job);
                  ops->store_error(ujob, error);
                  return (error);
          }
  
          if (opcode == LIO_SYNC && fp->f_vnode == NULL) {
                  error = EINVAL;
                  goto aqueue_fail;
          }
  
          if ((opcode == LIO_READ || opcode == LIO_WRITE) &&
              job->uaiocb.aio_offset < 0 &&
              (fp->f_vnode == NULL || fp->f_vnode->v_type != VCHR)) {
                  error = EINVAL;
                  goto aqueue_fail;
          }
  
          job->fd_file = fp;
  
          mtx_lock(&aio_job_mtx);
          jid = jobrefid++;
          job->seqno = jobseqno++;
          mtx_unlock(&aio_job_mtx);
          error = ops->store_kernelinfo(ujob, jid);
          if (error) {
                  error = EINVAL;
                  goto aqueue_fail;
          }
          job->uaiocb._aiocb_private.kernelinfo = (void *)(intptr_t)jid;
  
          if (opcode == LIO_NOP) {
                  fdrop(fp, td);
                  uma_zfree(aiocb_zone, job);
                  return (0);
          }
  
          if (job->uaiocb.aio_sigevent.sigev_notify != SIGEV_KEVENT)
                  goto no_kqueue;
          evflags = job->uaiocb.aio_sigevent.sigev_notify_kevent_flags;
          if ((evflags & ~(EV_CLEAR | EV_DISPATCH | EV_ONESHOT)) != 0) {
                  error = EINVAL;
                  goto aqueue_fail;
          }
          kqfd = job->uaiocb.aio_sigevent.sigev_notify_kqueue;
          memset(&kev, 0, sizeof(kev));
          kev.ident = (uintptr_t)job->ujob;
          kev.filter = EVFILT_AIO;
          kev.flags = EV_ADD | EV_ENABLE | EV_FLAG1 | evflags;
          kev.data = (intptr_t)job;
          kev.udata = job->uaiocb.aio_sigevent.sigev_value.sival_ptr;
          error = kqfd_register(kqfd, &kev, td, 1);
          if (error)
                  goto aqueue_fail;
  
  no_kqueue:
  
          ops->store_error(ujob, EINPROGRESS);
          job->uaiocb._aiocb_private.error = EINPROGRESS;
          job->userproc = p;
          job->cred = crhold(td->td_ucred);
          job->jobflags = KAIOCB_QUEUEING;
          job->lio = lj;
  
          if (opcode == LIO_MLOCK) {
                  aio_schedule(job, aio_process_mlock);
                  error = 0;
          } else if (fp->f_ops->fo_aio_queue == NULL)
                  error = aio_queue_file(fp, job);
          else
                  error = fo_aio_queue(fp, job);
          if (error)
                  goto aqueue_fail;
  
          AIO_LOCK(ki);
          job->jobflags &= ~KAIOCB_QUEUEING;
          TAILQ_INSERT_TAIL(&ki->kaio_all, job, allist);
          ki->kaio_count++;
          if (lj)
                  lj->lioj_count++;
          atomic_add_int(&num_queue_count, 1);
          if (job->jobflags & KAIOCB_FINISHED) {
                  /*
                   * The queue callback completed the request synchronously.
                   * The bulk of the completion is deferred in that case
                   * until this point.
                   */
                  aio_bio_done_notify(p, job);
          } else
                  TAILQ_INSERT_TAIL(&ki->kaio_jobqueue, job, plist);
          AIO_UNLOCK(ki);
          return (0);
  
  aqueue_fail:
          knlist_delete(&job->klist, curthread, 0);
          if (fp)
                  fdrop(fp, td);
          uma_zfree(aiocb_zone, job);
          ops->store_error(ujob, error);
          return (error);
  }
  
  static void
  aio_cancel_daemon_job(struct kaiocb *job)
  {
  
          mtx_lock(&aio_job_mtx);
          if (!aio_cancel_cleared(job))
                  TAILQ_REMOVE(&aio_jobs, job, list);
          mtx_unlock(&aio_job_mtx);
          aio_cancel(job);
  }
  
  void
  aio_schedule(struct kaiocb *job, aio_handle_fn_t *func)
  {
  
          mtx_lock(&aio_job_mtx);
          if (!aio_set_cancel_function(job, aio_cancel_daemon_job)) {
                  mtx_unlock(&aio_job_mtx);
                  aio_cancel(job);
                  return;
          }
          job->handle_fn = func;
          TAILQ_INSERT_TAIL(&aio_jobs, job, list);
          aio_kick_nowait(job->userproc);
          mtx_unlock(&aio_job_mtx);
  }
  
  static void
  aio_cancel_sync(struct kaiocb *job)
  {
          struct kaioinfo *ki;
  
          ki = job->userproc->p_aioinfo;
          AIO_LOCK(ki);
          if (!aio_cancel_cleared(job))
                  TAILQ_REMOVE(&ki->kaio_syncqueue, job, list);
          AIO_UNLOCK(ki);
          aio_cancel(job);
  }
  
  int
  aio_queue_file(struct file *fp, struct kaiocb *job)
  {
          struct aioliojob *lj;
          struct kaioinfo *ki;
          struct kaiocb *job2;
          struct vnode *vp;
          struct mount *mp;
          int error;
          bool safe;
  
          lj = job->lio;
          ki = job->userproc->p_aioinfo;
          error = aio_qbio(job->userproc, job);
          if (error >= 0)
                  return (error);
          safe = false;
          if (fp->f_type == DTYPE_VNODE) {
                  vp = fp->f_vnode;
                  if (vp->v_type == VREG || vp->v_type == VDIR) {
                          mp = fp->f_vnode->v_mount;
                          if (mp == NULL || (mp->mnt_flag & MNT_LOCAL) != 0)
                                  safe = true;
                  }
          }
          if (!(safe || enable_aio_unsafe)) {
                  counted_warning(&unsafe_warningcnt,
                      "is attempting to use unsafe AIO requests");
                  return (EOPNOTSUPP);
          }
  
          switch (job->uaiocb.aio_lio_opcode) {
          case LIO_READ:
          case LIO_WRITE:
                  aio_schedule(job, aio_process_rw);
                  error = 0;
                  break;
          case LIO_SYNC:
                  AIO_LOCK(ki);
                  TAILQ_FOREACH(job2, &ki->kaio_jobqueue, plist) {
                          if (job2->fd_file == job->fd_file &&
                              job2->uaiocb.aio_lio_opcode != LIO_SYNC &&
                              job2->seqno < job->seqno) {
                                  job2->jobflags |= KAIOCB_CHECKSYNC;
                                  job->pending++;
                          }
                  }
                  if (job->pending != 0) {
                          if (!aio_set_cancel_function_locked(job,
                                  aio_cancel_sync)) {
                                  AIO_UNLOCK(ki);
                                  aio_cancel(job);
                                  return (0);
                          }
                          TAILQ_INSERT_TAIL(&ki->kaio_syncqueue, job, list);
                          AIO_UNLOCK(ki);
                          return (0);
                  }
                  AIO_UNLOCK(ki);
                  aio_schedule(job, aio_process_sync);
                  error = 0;
                  break;
          default:
                  error = EINVAL;
          }
          return (error);
  }
  
  static void
  aio_kick_nowait(struct proc *userp)
  {
          struct kaioinfo *ki = userp->p_aioinfo;
          struct aioproc *aiop;
  
          mtx_assert(&aio_job_mtx, MA_OWNED);
          if ((aiop = TAILQ_FIRST(&aio_freeproc)) != NULL) {
                  TAILQ_REMOVE(&aio_freeproc, aiop, list);
                  aiop->aioprocflags &= ~AIOP_FREE;
                  wakeup(aiop->aioproc);
          } else if (num_aio_resv_start + num_aio_procs < max_aio_procs &&
              ki->kaio_active_count + num_aio_resv_start < max_aio_per_proc) {
                  taskqueue_enqueue(taskqueue_aiod_kick, &ki->kaio_task);
          }
  }
  
  static int
  aio_kick(struct proc *userp)
  {
          struct kaioinfo *ki = userp->p_aioinfo;
          struct aioproc *aiop;
          int error, ret = 0;
  
          mtx_assert(&aio_job_mtx, MA_OWNED);
  retryproc:
          if ((aiop = TAILQ_FIRST(&aio_freeproc)) != NULL) {
                  TAILQ_REMOVE(&aio_freeproc, aiop, list);
                  aiop->aioprocflags &= ~AIOP_FREE;
                  wakeup(aiop->aioproc);
          } else if (num_aio_resv_start + num_aio_procs < max_aio_procs &&
              ki->kaio_active_count + num_aio_resv_start < max_aio_per_proc) {
                  num_aio_resv_start++;
                  mtx_unlock(&aio_job_mtx);
                  error = aio_newproc(&num_aio_resv_start);
                  mtx_lock(&aio_job_mtx);
                  if (error) {
                          num_aio_resv_start--;
                          goto retryproc;
                  }
          } else {
                  ret = -1;
          }
          return (ret);
  }
  
  static void
  aio_kick_helper(void *context, int pending)
  {
          struct proc *userp = context;
  
          mtx_lock(&aio_job_mtx);
          while (--pending >= 0) {
                  if (aio_kick(userp))
                          break;
          }
          mtx_unlock(&aio_job_mtx);
  }
  
  /*
   * Support the aio_return system call, as a side-effect, kernel resources are
   * released.
   */
  static int
  kern_aio_return(struct thread *td, struct aiocb *ujob, struct aiocb_ops *ops)
  {
          struct proc *p = td->td_proc;
          struct kaiocb *job;
          struct kaioinfo *ki;
          long status, error;
  
          ki = p->p_aioinfo;
          if (ki == NULL)
                  return (EINVAL);
          AIO_LOCK(ki);
          TAILQ_FOREACH(job, &ki->kaio_done, plist) {
                  if (job->ujob == ujob)
                          break;
          }
          if (job != NULL) {
                  MPASS(job->jobflags & KAIOCB_FINISHED);
                  status = job->uaiocb._aiocb_private.status;
                  error = job->uaiocb._aiocb_private.error;
                  td->td_retval[0] = status;
                  td->td_ru.ru_oublock += job->outblock;
                  td->td_ru.ru_inblock += job->inblock;
                  td->td_ru.ru_msgsnd += job->msgsnd;
                  td->td_ru.ru_msgrcv += job->msgrcv;
                  aio_free_entry(job);
                  AIO_UNLOCK(ki);
                  ops->store_error(ujob, error);
                  ops->store_status(ujob, status);
          } else {
                  error = EINVAL;
                  AIO_UNLOCK(ki);
          }
          return (error);
  }
  
  int
  sys_aio_return(struct thread *td, struct aio_return_args *uap)
  {
  
          return (kern_aio_return(td, uap->aiocbp, &aiocb_ops));
  }
  
  /*
   * Allow a process to wakeup when any of the I/O requests are completed.
   */
  static int
  kern_aio_suspend(struct thread *td, int njoblist, struct aiocb **ujoblist,
      struct timespec *ts)
  {
          struct proc *p = td->td_proc;
          struct timeval atv;
          struct kaioinfo *ki;
          struct kaiocb *firstjob, *job;
          int error, i, timo;
  
          timo = 0;
          if (ts) {
                  if (ts->tv_nsec < 0 || ts->tv_nsec >= 1000000000)
                          return (EINVAL);
  
                  TIMESPEC_TO_TIMEVAL(&atv, ts);
                  if (itimerfix(&atv))
                          return (EINVAL);
                  timo = tvtohz(&atv);
          }
  
          ki = p->p_aioinfo;
          if (ki == NULL)
                  return (EAGAIN);
  
          if (njoblist == 0)
                  return (0);
  
          AIO_LOCK(ki);
          for (;;) {
                  firstjob = NULL;
                  error = 0;
                  TAILQ_FOREACH(job, &ki->kaio_all, allist) {
                          for (i = 0; i < njoblist; i++) {
                                  if (job->ujob == ujoblist[i]) {
                                          if (firstjob == NULL)
                                                  firstjob = job;
                                          if (job->jobflags & KAIOCB_FINISHED)
                                                  goto RETURN;
                                  }
                          }
                  }
                  /* All tasks were finished. */
                  if (firstjob == NULL)
                          break;
  
                  ki->kaio_flags |= KAIO_WAKEUP;
                  error = msleep(&p->p_aioinfo, AIO_MTX(ki), PRIBIO | PCATCH,
                      "aiospn", timo);
                  if (error == ERESTART)
                          error = EINTR;
                  if (error)
                          break;
          }
  RETURN:
          AIO_UNLOCK(ki);
          return (error);
  }
  
  int
  sys_aio_suspend(struct thread *td, struct aio_suspend_args *uap)
  {
          struct timespec ts, *tsp;
          struct aiocb **ujoblist;
          int error;
  
          if (uap->nent < 0 || uap->nent > max_aio_queue_per_proc)
                  return (EINVAL);
  
          if (uap->timeout) {
                  /* Get timespec struct. */
                  if ((error = copyin(uap->timeout, &ts, sizeof(ts))) != 0)
                          return (error);
                  tsp = &ts;
          } else
                  tsp = NULL;
  
          ujoblist = malloc(uap->nent * sizeof(ujoblist[0]), M_AIOS, M_WAITOK);
          error = copyin(uap->aiocbp, ujoblist, uap->nent * sizeof(ujoblist[0]));
          if (error == 0)
                  error = kern_aio_suspend(td, uap->nent, ujoblist, tsp);
          free(ujoblist, M_AIOS);
          return (error);
  }
  
  /*
   * aio_cancel cancels any non-bio aio operations not currently in progress.
   */
  int
  sys_aio_cancel(struct thread *td, struct aio_cancel_args *uap)
  {
          struct proc *p = td->td_proc;
          struct kaioinfo *ki;
          struct kaiocb *job, *jobn;
          struct file *fp;
          cap_rights_t rights;
          int error;
          int cancelled = 0;
          int notcancelled = 0;
          struct vnode *vp;
  
          /* Lookup file object. */
          error = fget(td, uap->fd, cap_rights_init(&rights), &fp);
          if (error)
                  return (error);
  
          ki = p->p_aioinfo;
          if (ki == NULL)
                  goto done;
  
          if (fp->f_type == DTYPE_VNODE) {
                  vp = fp->f_vnode;
                  if (vn_isdisk(vp, &error)) {
                          fdrop(fp, td);
                          td->td_retval[0] = AIO_NOTCANCELED;
                          return (0);
                  }
          }
  
          AIO_LOCK(ki);
          TAILQ_FOREACH_SAFE(job, &ki->kaio_jobqueue, plist, jobn) {
                  if ((uap->fd == job->uaiocb.aio_fildes) &&
                      ((uap->aiocbp == NULL) ||
                       (uap->aiocbp == job->ujob))) {
                          if (aio_cancel_job(p, ki, job)) {
                                  cancelled++;
                          } else {
                                  notcancelled++;
                          }
                          if (uap->aiocbp != NULL)
                                  break;
                  }
          }
          AIO_UNLOCK(ki);
  
  done:
          fdrop(fp, td);
  
          if (uap->aiocbp != NULL) {
                  if (cancelled) {
                          td->td_retval[0] = AIO_CANCELED;
                          return (0);
                  }
          }
  
          if (notcancelled) {
                  td->td_retval[0] = AIO_NOTCANCELED;
                  return (0);
          }
  
          if (cancelled) {
                  td->td_retval[0] = AIO_CANCELED;
                  return (0);
          }
  
          td->td_retval[0] = AIO_ALLDONE;
  
          return (0);
  }
  
  /*
   * aio_error is implemented in the kernel level for compatibility purposes
   * only.  For a user mode async implementation, it would be best to do it in
   * a userland subroutine.
   */
  static int
  kern_aio_error(struct thread *td, struct aiocb *ujob, struct aiocb_ops *ops)
  {
          struct proc *p = td->td_proc;
          struct kaiocb *job;
          struct kaioinfo *ki;
          int status;
  
          ki = p->p_aioinfo;
          if (ki == NULL) {
                  td->td_retval[0] = EINVAL;
                  return (0);
          }
  
          AIO_LOCK(ki);
          TAILQ_FOREACH(job, &ki->kaio_all, allist) {
                  if (job->ujob == ujob) {
                          if (job->jobflags & KAIOCB_FINISHED)
                                  td->td_retval[0] =
                                          job->uaiocb._aiocb_private.error;
                          else
                                  td->td_retval[0] = EINPROGRESS;
                          AIO_UNLOCK(ki);
                          return (0);
                  }
          }
          AIO_UNLOCK(ki);
  
          /*
           * Hack for failure of aio_aqueue.
           */
          status = ops->fetch_status(ujob);
          if (status == -1) {
                  td->td_retval[0] = ops->fetch_error(ujob);
                  return (0);
          }
  
          td->td_retval[0] = EINVAL;
          return (0);
  }
  
  int
  sys_aio_error(struct thread *td, struct aio_error_args *uap)
  {
  
          return (kern_aio_error(td, uap->aiocbp, &aiocb_ops));
  }
  
  /* syscall - asynchronous read from a file (REALTIME) */
  #ifdef COMPAT_FREEBSD6
  int
  freebsd6_aio_read(struct thread *td, struct freebsd6_aio_read_args *uap)
  {
  
          return (aio_aqueue(td, (struct aiocb *)uap->aiocbp, NULL, LIO_READ,
              &aiocb_ops_osigevent));
  }
  #endif
  
  int
  sys_aio_read(struct thread *td, struct aio_read_args *uap)
  {
  
          return (aio_aqueue(td, uap->aiocbp, NULL, LIO_READ, &aiocb_ops));
  }
  
  /* syscall - asynchronous write to a file (REALTIME) */
  #ifdef COMPAT_FREEBSD6
  int
  freebsd6_aio_write(struct thread *td, struct freebsd6_aio_write_args *uap)
  {
  
          return (aio_aqueue(td, (struct aiocb *)uap->aiocbp, NULL, LIO_WRITE,
              &aiocb_ops_osigevent));
  }
  #endif
  
  int
  sys_aio_write(struct thread *td, struct aio_write_args *uap)
  {
  
          return (aio_aqueue(td, uap->aiocbp, NULL, LIO_WRITE, &aiocb_ops));
  }
  
  int
  sys_aio_mlock(struct thread *td, struct aio_mlock_args *uap)
  {
  
          return (aio_aqueue(td, uap->aiocbp, NULL, LIO_MLOCK, &aiocb_ops));
  }
  
  static int
  kern_lio_listio(struct thread *td, int mode, struct aiocb * const *uacb_list,
      struct aiocb **acb_list, int nent, struct sigevent *sig,
      struct aiocb_ops *ops)
  {
          struct proc *p = td->td_proc;
          struct aiocb *job;
          struct kaioinfo *ki;
          struct aioliojob *lj;
          struct kevent kev;
          int error;
          int nagain, nerror;
          int i;
  
          if ((mode != LIO_NOWAIT) && (mode != LIO_WAIT))
                  return (EINVAL);
  
          if (nent < 0 || nent > max_aio_queue_per_proc)
                  return (EINVAL);
  
          if (p->p_aioinfo == NULL)
                  aio_init_aioinfo(p);
  
          ki = p->p_aioinfo;
  
          lj = uma_zalloc(aiolio_zone, M_WAITOK);
          lj->lioj_flags = 0;
          lj->lioj_count = 0;
          lj->lioj_finished_count = 0;
          knlist_init_mtx(&lj->klist, AIO_MTX(ki));
          ksiginfo_init(&lj->lioj_ksi);
  
          /*
           * Setup signal.
           */
          if (sig && (mode == LIO_NOWAIT)) {
                  bcopy(sig, &lj->lioj_signal, sizeof(lj->lioj_signal));
                  if (lj->lioj_signal.sigev_notify == SIGEV_KEVENT) {
                          /* Assume only new style KEVENT */
                          memset(&kev, 0, sizeof(kev));
                          kev.filter = EVFILT_LIO;
                          kev.flags = EV_ADD | EV_ENABLE | EV_FLAG1;
                          kev.ident = (uintptr_t)uacb_list; /* something unique */
                          kev.data = (intptr_t)lj;
                          /* pass user defined sigval data */
                          kev.udata = lj->lioj_signal.sigev_value.sival_ptr;
                          error = kqfd_register(
                              lj->lioj_signal.sigev_notify_kqueue, &kev, td, 1);
                          if (error) {
                                  uma_zfree(aiolio_zone, lj);
                                  return (error);
                          }
                  } else if (lj->lioj_signal.sigev_notify == SIGEV_NONE) {
                          ;
                  } else if (lj->lioj_signal.sigev_notify == SIGEV_SIGNAL ||
                             lj->lioj_signal.sigev_notify == SIGEV_THREAD_ID) {
                                  if (!_SIG_VALID(lj->lioj_signal.sigev_signo)) {
                                          uma_zfree(aiolio_zone, lj);
                                          return EINVAL;
                                  }
                                  lj->lioj_flags |= LIOJ_SIGNAL;
                  } else {
                          uma_zfree(aiolio_zone, lj);
                          return EINVAL;
                  }
          }
  
          AIO_LOCK(ki);
          TAILQ_INSERT_TAIL(&ki->kaio_liojoblist, lj, lioj_list);
          /*
           * Add extra aiocb count to avoid the lio to be freed
           * by other threads doing aio_waitcomplete or aio_return,
           * and prevent event from being sent until we have queued
           * all tasks.
           */
          lj->lioj_count = 1;
          AIO_UNLOCK(ki);
  
          /*
           * Get pointers to the list of I/O requests.
           */
          nagain = 0;
          nerror = 0;
          for (i = 0; i < nent; i++) {
                  job = acb_list[i];
                  if (job != NULL) {
                          error = aio_aqueue(td, job, lj, LIO_NOP, ops);
                          if (error == EAGAIN)
                                  nagain++;
                          else if (error != 0)
                                  nerror++;
                  }
          }
  
          error = 0;
          AIO_LOCK(ki);
          if (mode == LIO_WAIT) {
                  while (lj->lioj_count - 1 != lj->lioj_finished_count) {
                          ki->kaio_flags |= KAIO_WAKEUP;
                          error = msleep(&p->p_aioinfo, AIO_MTX(ki),
                              PRIBIO | PCATCH, "aiospn", 0);
                          if (error == ERESTART)
                                  error = EINTR;
                          if (error)
                                  break;
                  }
          } else {
                  if (lj->lioj_count - 1 == lj->lioj_finished_count) {
                          if (lj->lioj_signal.sigev_notify == SIGEV_KEVENT) {
                                  lj->lioj_flags |= LIOJ_KEVENT_POSTED;
                                  KNOTE_LOCKED(&lj->klist, 1);
                          }
                          if ((lj->lioj_flags & (LIOJ_SIGNAL|LIOJ_SIGNAL_POSTED))
                              == LIOJ_SIGNAL
                              && (lj->lioj_signal.sigev_notify == SIGEV_SIGNAL ||
                              lj->lioj_signal.sigev_notify == SIGEV_THREAD_ID)) {
                                  aio_sendsig(p, &lj->lioj_signal,
                                              &lj->lioj_ksi);
                                  lj->lioj_flags |= LIOJ_SIGNAL_POSTED;
                          }
                  }
          }
          lj->lioj_count--;
          if (lj->lioj_count == 0) {
                  TAILQ_REMOVE(&ki->kaio_liojoblist, lj, lioj_list);
                  knlist_delete(&lj->klist, curthread, 1);
                  PROC_LOCK(p);
                  sigqueue_take(&lj->lioj_ksi);
                  PROC_UNLOCK(p);
                  AIO_UNLOCK(ki);
                  uma_zfree(aiolio_zone, lj);
          } else
                  AIO_UNLOCK(ki);
  
          if (nerror)
                  return (EIO);
          else if (nagain)
                  return (EAGAIN);
          else
                  return (error);
  }
  
  /* syscall - list directed I/O (REALTIME) */
  #ifdef COMPAT_FREEBSD6
  int
  freebsd6_lio_listio(struct thread *td, struct freebsd6_lio_listio_args *uap)
  {
          struct aiocb **acb_list;
          struct sigevent *sigp, sig;
          struct osigevent osig;
          int error, nent;
  
          if ((uap->mode != LIO_NOWAIT) && (uap->mode != LIO_WAIT))
                  return (EINVAL);
  
          nent = uap->nent;
          if (nent < 0 || nent > max_aio_queue_per_proc)
                  return (EINVAL);
  
          if (uap->sig && (uap->mode == LIO_NOWAIT)) {
                  error = copyin(uap->sig, &osig, sizeof(osig));
                  if (error)
                          return (error);
                  error = convert_old_sigevent(&osig, &sig);
                  if (error)
                          return (error);
                  sigp = &sig;
          } else
                  sigp = NULL;
  
          acb_list = malloc(sizeof(struct aiocb *) * nent, M_LIO, M_WAITOK);
          error = copyin(uap->acb_list, acb_list, nent * sizeof(acb_list[0]));
          if (error == 0)
                  error = kern_lio_listio(td, uap->mode,
                      (struct aiocb * const *)uap->acb_list, acb_list, nent, sigp,
                      &aiocb_ops_osigevent);
          free(acb_list, M_LIO);
          return (error);
  }
  #endif
  
  /* syscall - list directed I/O (REALTIME) */
  int
  sys_lio_listio(struct thread *td, struct lio_listio_args *uap)
  {
          struct aiocb **acb_list;
          struct sigevent *sigp, sig;
          int error, nent;
  
          if ((uap->mode != LIO_NOWAIT) && (uap->mode != LIO_WAIT))
                  return (EINVAL);
  
          nent = uap->nent;
          if (nent < 0 || nent > max_aio_queue_per_proc)
                  return (EINVAL);
  
          if (uap->sig && (uap->mode == LIO_NOWAIT)) {
                  error = copyin(uap->sig, &sig, sizeof(sig));
                  if (error)
                          return (error);
                  sigp = &sig;
          } else
                  sigp = NULL;
  
          acb_list = malloc(sizeof(struct aiocb *) * nent, M_LIO, M_WAITOK);
          error = copyin(uap->acb_list, acb_list, nent * sizeof(acb_list[0]));
          if (error == 0)
                  error = kern_lio_listio(td, uap->mode, uap->acb_list, acb_list,
                      nent, sigp, &aiocb_ops);
          free(acb_list, M_LIO);
          return (error);
  }
  
  static void
  aio_biowakeup(struct bio *bp)
  {
          struct kaiocb *job = (struct kaiocb *)bp->bio_caller1;
          struct proc *userp;
          struct kaioinfo *ki;
          size_t nbytes;
          int error, nblks;
  
          /* Release mapping into kernel space. */
          userp = job->userproc;
          ki = userp->p_aioinfo;
          if (job->pbuf) {
                  pmap_qremove((vm_offset_t)job->pbuf->b_data, job->npages);
                  relpbuf(job->pbuf, NULL);
                  job->pbuf = NULL;
                  atomic_subtract_int(&num_buf_aio, 1);
                  AIO_LOCK(ki);
                  ki->kaio_buffer_count--;
                  AIO_UNLOCK(ki);
          } else
                  atomic_subtract_int(&num_unmapped_aio, 1);
          vm_page_unhold_pages(job->pages, job->npages);
  
          bp = job->bp;
          job->bp = NULL;
          nbytes = job->uaiocb.aio_nbytes - bp->bio_resid;
          error = 0;
          if (bp->bio_flags & BIO_ERROR)
                  error = bp->bio_error;
          nblks = btodb(nbytes);
          if (job->uaiocb.aio_lio_opcode == LIO_WRITE)
                  job->outblock += nblks;
          else
                  job->inblock += nblks;
  
          if (error)
                  aio_complete(job, -1, error);
          else
                  aio_complete(job, nbytes, 0);
  
          g_destroy_bio(bp);
  }
  
  /* syscall - wait for the next completion of an aio request */
  static int
  kern_aio_waitcomplete(struct thread *td, struct aiocb **ujobp,
      struct timespec *ts, struct aiocb_ops *ops)
  {
          struct proc *p = td->td_proc;
          struct timeval atv;
          struct kaioinfo *ki;
          struct kaiocb *job;
          struct aiocb *ujob;
          long error, status;
          int timo;
  
          ops->store_aiocb(ujobp, NULL);
  
          if (ts == NULL) {
                  timo = 0;
          } else if (ts->tv_sec == 0 && ts->tv_nsec == 0) {
                  timo = -1;
          } else {
                  if ((ts->tv_nsec < 0) || (ts->tv_nsec >= 1000000000))
                          return (EINVAL);
  
                  TIMESPEC_TO_TIMEVAL(&atv, ts);
                  if (itimerfix(&atv))
                          return (EINVAL);
                  timo = tvtohz(&atv);
          }
  
          if (p->p_aioinfo == NULL)
                  aio_init_aioinfo(p);
          ki = p->p_aioinfo;
  
          error = 0;
          job = NULL;
          AIO_LOCK(ki);
          while ((job = TAILQ_FIRST(&ki->kaio_done)) == NULL) {
                  if (timo == -1) {
                          error = EWOULDBLOCK;
                          break;
                  }
                  ki->kaio_flags |= KAIO_WAKEUP;
                  error = msleep(&p->p_aioinfo, AIO_MTX(ki), PRIBIO | PCATCH,
                      "aiowc", timo);
                  if (timo && error == ERESTART)
                          error = EINTR;
                  if (error)
                          break;
          }
  
          if (job != NULL) {
                  MPASS(job->jobflags & KAIOCB_FINISHED);
                  ujob = job->ujob;
                  status = job->uaiocb._aiocb_private.status;
                  error = job->uaiocb._aiocb_private.error;
                  td->td_retval[0] = status;
                  td->td_ru.ru_oublock += job->outblock;
                  td->td_ru.ru_inblock += job->inblock;
                  td->td_ru.ru_msgsnd += job->msgsnd;
                  td->td_ru.ru_msgrcv += job->msgrcv;
                  aio_free_entry(job);
                  AIO_UNLOCK(ki);
                  ops->store_aiocb(ujobp, ujob);
                  ops->store_error(ujob, error);
                  ops->store_status(ujob, status);
          } else
                  AIO_UNLOCK(ki);
  
          return (error);
  }
  
  int
  sys_aio_waitcomplete(struct thread *td, struct aio_waitcomplete_args *uap)
  {
          struct timespec ts, *tsp;
          int error;
  
          if (uap->timeout) {
                  /* Get timespec struct. */
                  error = copyin(uap->timeout, &ts, sizeof(ts));
                  if (error)
                          return (error);
                  tsp = &ts;
          } else
                  tsp = NULL;
  
          return (kern_aio_waitcomplete(td, uap->aiocbp, tsp, &aiocb_ops));
  }
  
  static int
  kern_aio_fsync(struct thread *td, int op, struct aiocb *ujob,
      struct aiocb_ops *ops)
  {
  
          if (op != O_SYNC) /* XXX lack of O_DSYNC */
                  return (EINVAL);
          return (aio_aqueue(td, ujob, NULL, LIO_SYNC, ops));
  }
  
  int
  sys_aio_fsync(struct thread *td, struct aio_fsync_args *uap)
  {
  
          return (kern_aio_fsync(td, uap->op, uap->aiocbp, &aiocb_ops));
  }
  
  /* kqueue attach function */
  static int
  filt_aioattach(struct knote *kn)
  {
          struct kaiocb *job = (struct kaiocb *)kn->kn_sdata;
  
          /*
           * The job pointer must be validated before using it, so
           * registration is restricted to the kernel; the user cannot
           * set EV_FLAG1.
           */
          if ((kn->kn_flags & EV_FLAG1) == 0)
                  return (EPERM);
          kn->kn_ptr.p_aio = job;
          kn->kn_flags &= ~EV_FLAG1;
  
          knlist_add(&job->klist, kn, 0);
  
          return (0);
  }
  
  /* kqueue detach function */
  static void
  filt_aiodetach(struct knote *kn)
  {
          struct knlist *knl;
  
          knl = &kn->kn_ptr.p_aio->klist;
          knl->kl_lock(knl->kl_lockarg);
          if (!knlist_empty(knl))
                  knlist_remove(knl, kn, 1);
          knl->kl_unlock(knl->kl_lockarg);
  }
  
  /* kqueue filter function */
  /*ARGSUSED*/
  static int
  filt_aio(struct knote *kn, long hint)
  {
          struct kaiocb *job = kn->kn_ptr.p_aio;
  
          kn->kn_data = job->uaiocb._aiocb_private.error;
          if (!(job->jobflags & KAIOCB_FINISHED))
                  return (0);
          kn->kn_flags |= EV_EOF;
          return (1);
  }
  
  /* kqueue attach function */
  static int
  filt_lioattach(struct knote *kn)
  {
          struct aioliojob * lj = (struct aioliojob *)kn->kn_sdata;
  
          /*
           * The aioliojob pointer must be validated before using it, so
           * registration is restricted to the kernel; the user cannot
           * set EV_FLAG1.
           */
          if ((kn->kn_flags & EV_FLAG1) == 0)
                  return (EPERM);
          kn->kn_ptr.p_lio = lj;
          kn->kn_flags &= ~EV_FLAG1;
  
          knlist_add(&lj->klist, kn, 0);
  
          return (0);
  }
  
  /* kqueue detach function */
  static void
  filt_liodetach(struct knote *kn)
  {
          struct knlist *knl;
  
          knl = &kn->kn_ptr.p_lio->klist;
          knl->kl_lock(knl->kl_lockarg);
          if (!knlist_empty(knl))
                  knlist_remove(knl, kn, 1);
          knl->kl_unlock(knl->kl_lockarg);
  }
  
  /* kqueue filter function */
  /*ARGSUSED*/
  static int
  filt_lio(struct knote *kn, long hint)
  {
          struct aioliojob * lj = kn->kn_ptr.p_lio;
  
          return (lj->lioj_flags & LIOJ_KEVENT_POSTED);
  }
  
  #ifdef COMPAT_FREEBSD32
  #include <sys/mount.h>
  #include <sys/socket.h>
  #include <compat/freebsd32/freebsd32.h>
  #include <compat/freebsd32/freebsd32_proto.h>
  #include <compat/freebsd32/freebsd32_signal.h>
  #include <compat/freebsd32/freebsd32_syscall.h>
  #include <compat/freebsd32/freebsd32_util.h>
  
  struct __aiocb_private32 {
          int32_t status;
          int32_t error;
          uint32_t kernelinfo;
  };
  
  #ifdef COMPAT_FREEBSD6
  typedef struct oaiocb32 {
          int     aio_fildes;             /* File descriptor */
          uint64_t aio_offset __packed;   /* File offset for I/O */
          uint32_t aio_buf;               /* I/O buffer in process space */
          uint32_t aio_nbytes;            /* Number of bytes for I/O */
          struct  osigevent32 aio_sigevent; /* Signal to deliver */
          int     aio_lio_opcode;         /* LIO opcode */
          int     aio_reqprio;            /* Request priority -- ignored */
          struct  __aiocb_private32 _aiocb_private;
  } oaiocb32_t;
  #endif
  
  typedef struct aiocb32 {
          int32_t aio_fildes;             /* File descriptor */
          uint64_t aio_offset __packed;   /* File offset for I/O */
          uint32_t aio_buf;               /* I/O buffer in process space */
          uint32_t aio_nbytes;            /* Number of bytes for I/O */
          int     __spare__[2];
          uint32_t __spare2__;
          int     aio_lio_opcode;         /* LIO opcode */
          int     aio_reqprio;            /* Request priority -- ignored */
          struct  __aiocb_private32 _aiocb_private;
          struct  sigevent32 aio_sigevent;        /* Signal to deliver */
  } aiocb32_t;
  
  #ifdef COMPAT_FREEBSD6
  static int
  convert_old_sigevent32(struct osigevent32 *osig, struct sigevent *nsig)
  {
  
          /*
           * Only SIGEV_NONE, SIGEV_SIGNAL, and SIGEV_KEVENT are
           * supported by AIO with the old sigevent structure.
           */
          CP(*osig, *nsig, sigev_notify);
          switch (nsig->sigev_notify) {
          case SIGEV_NONE:
                  break;
          case SIGEV_SIGNAL:
                  nsig->sigev_signo = osig->__sigev_u.__sigev_signo;
                  break;
          case SIGEV_KEVENT:
                  nsig->sigev_notify_kqueue =
                      osig->__sigev_u.__sigev_notify_kqueue;
                  PTRIN_CP(*osig, *nsig, sigev_value.sival_ptr);
                  break;
          default:
                  return (EINVAL);
          }
          return (0);
  }
  
  static int
  aiocb32_copyin_old_sigevent(struct aiocb *ujob, struct aiocb *kjob)
  {
          struct oaiocb32 job32;
          int error;
  
          bzero(kjob, sizeof(struct aiocb));
          error = copyin(ujob, &job32, sizeof(job32));
          if (error)
                  return (error);
  
          CP(job32, *kjob, aio_fildes);
          CP(job32, *kjob, aio_offset);
          PTRIN_CP(job32, *kjob, aio_buf);
          CP(job32, *kjob, aio_nbytes);
          CP(job32, *kjob, aio_lio_opcode);
          CP(job32, *kjob, aio_reqprio);
          CP(job32, *kjob, _aiocb_private.status);
          CP(job32, *kjob, _aiocb_private.error);
          PTRIN_CP(job32, *kjob, _aiocb_private.kernelinfo);
          return (convert_old_sigevent32(&job32.aio_sigevent,
              &kjob->aio_sigevent));
  }
  #endif
  
  static int
  aiocb32_copyin(struct aiocb *ujob, struct aiocb *kjob)
  {
          struct aiocb32 job32;
          int error;
  
          error = copyin(ujob, &job32, sizeof(job32));
          if (error)
                  return (error);
          CP(job32, *kjob, aio_fildes);
          CP(job32, *kjob, aio_offset);
          PTRIN_CP(job32, *kjob, aio_buf);
          CP(job32, *kjob, aio_nbytes);
          CP(job32, *kjob, aio_lio_opcode);
          CP(job32, *kjob, aio_reqprio);
          CP(job32, *kjob, _aiocb_private.status);
          CP(job32, *kjob, _aiocb_private.error);
          PTRIN_CP(job32, *kjob, _aiocb_private.kernelinfo);
          return (convert_sigevent32(&job32.aio_sigevent, &kjob->aio_sigevent));
  }
  
  static long
  aiocb32_fetch_status(struct aiocb *ujob)
  {
          struct aiocb32 *ujob32;
  
          ujob32 = (struct aiocb32 *)ujob;
          return (fuword32(&ujob32->_aiocb_private.status));
  }
  
  static long
  aiocb32_fetch_error(struct aiocb *ujob)
  {
          struct aiocb32 *ujob32;
  
          ujob32 = (struct aiocb32 *)ujob;
          return (fuword32(&ujob32->_aiocb_private.error));
  }
  
  static int
  aiocb32_store_status(struct aiocb *ujob, long status)
  {
          struct aiocb32 *ujob32;
  
          ujob32 = (struct aiocb32 *)ujob;
          return (suword32(&ujob32->_aiocb_private.status, status));
  }
  
  static int
  aiocb32_store_error(struct aiocb *ujob, long error)
  {
          struct aiocb32 *ujob32;
  
          ujob32 = (struct aiocb32 *)ujob;
          return (suword32(&ujob32->_aiocb_private.error, error));
  }
  
  static int
  aiocb32_store_kernelinfo(struct aiocb *ujob, long jobref)
  {
          struct aiocb32 *ujob32;
  
          ujob32 = (struct aiocb32 *)ujob;
          return (suword32(&ujob32->_aiocb_private.kernelinfo, jobref));
  }
  
  static int
  aiocb32_store_aiocb(struct aiocb **ujobp, struct aiocb *ujob)
  {
  
          return (suword32(ujobp, (long)ujob));
  }
  
  static struct aiocb_ops aiocb32_ops = {
          .copyin = aiocb32_copyin,
          .fetch_status = aiocb32_fetch_status,
          .fetch_error = aiocb32_fetch_error,
          .store_status = aiocb32_store_status,
          .store_error = aiocb32_store_error,
          .store_kernelinfo = aiocb32_store_kernelinfo,
          .store_aiocb = aiocb32_store_aiocb,
  };
  
  #ifdef COMPAT_FREEBSD6
  static struct aiocb_ops aiocb32_ops_osigevent = {
          .copyin = aiocb32_copyin_old_sigevent,
          .fetch_status = aiocb32_fetch_status,
          .fetch_error = aiocb32_fetch_error,
          .store_status = aiocb32_store_status,
          .store_error = aiocb32_store_error,
          .store_kernelinfo = aiocb32_store_kernelinfo,
          .store_aiocb = aiocb32_store_aiocb,
  };
  #endif
  
  int
  freebsd32_aio_return(struct thread *td, struct freebsd32_aio_return_args *uap)
  {
  
          return (kern_aio_return(td, (struct aiocb *)uap->aiocbp, &aiocb32_ops));
  }
  
  int
  freebsd32_aio_suspend(struct thread *td, struct freebsd32_aio_suspend_args *uap)
  {
          struct timespec32 ts32;
          struct timespec ts, *tsp;
          struct aiocb **ujoblist;
          uint32_t *ujoblist32;
          int error, i;
  
          if (uap->nent < 0 || uap->nent > max_aio_queue_per_proc)
                  return (EINVAL);
  
          if (uap->timeout) {
                  /* Get timespec struct. */
                  if ((error = copyin(uap->timeout, &ts32, sizeof(ts32))) != 0)
                          return (error);
                  CP(ts32, ts, tv_sec);
                  CP(ts32, ts, tv_nsec);
                  tsp = &ts;
          } else
                  tsp = NULL;
  
          ujoblist = malloc(uap->nent * sizeof(ujoblist[0]), M_AIOS, M_WAITOK);
          ujoblist32 = (uint32_t *)ujoblist;
          error = copyin(uap->aiocbp, ujoblist32, uap->nent *
              sizeof(ujoblist32[0]));
          if (error == 0) {
                  for (i = uap->nent - 1; i >= 0; i--)
                          ujoblist[i] = PTRIN(ujoblist32[i]);
  
                  error = kern_aio_suspend(td, uap->nent, ujoblist, tsp);
          }
          free(ujoblist, M_AIOS);
          return (error);
  }
  
  int
  freebsd32_aio_error(struct thread *td, struct freebsd32_aio_error_args *uap)
  {
  
          return (kern_aio_error(td, (struct aiocb *)uap->aiocbp, &aiocb32_ops));
  }
  
  #ifdef COMPAT_FREEBSD6
  int
  freebsd6_freebsd32_aio_read(struct thread *td,
      struct freebsd6_freebsd32_aio_read_args *uap)
  {
  
          return (aio_aqueue(td, (struct aiocb *)uap->aiocbp, NULL, LIO_READ,
              &aiocb32_ops_osigevent));
  }
  #endif
  
  int
  freebsd32_aio_read(struct thread *td, struct freebsd32_aio_read_args *uap)
  {
  
          return (aio_aqueue(td, (struct aiocb *)uap->aiocbp, NULL, LIO_READ,
              &aiocb32_ops));
  }
  
  #ifdef COMPAT_FREEBSD6
  int
  freebsd6_freebsd32_aio_write(struct thread *td,
      struct freebsd6_freebsd32_aio_write_args *uap)
  {
  
          return (aio_aqueue(td, (struct aiocb *)uap->aiocbp, NULL, LIO_WRITE,
              &aiocb32_ops_osigevent));
  }
  #endif
  
  int
  freebsd32_aio_write(struct thread *td, struct freebsd32_aio_write_args *uap)
  {
  
          return (aio_aqueue(td, (struct aiocb *)uap->aiocbp, NULL, LIO_WRITE,
              &aiocb32_ops));
  }
  
  int
  freebsd32_aio_mlock(struct thread *td, struct freebsd32_aio_mlock_args *uap)
  {
  
          return (aio_aqueue(td, (struct aiocb *)uap->aiocbp, NULL, LIO_MLOCK,
              &aiocb32_ops));
  }
  
  int
  freebsd32_aio_waitcomplete(struct thread *td,
      struct freebsd32_aio_waitcomplete_args *uap)
  {
          struct timespec32 ts32;
          struct timespec ts, *tsp;
          int error;
  
          if (uap->timeout) {
                  /* Get timespec struct. */
                  error = copyin(uap->timeout, &ts32, sizeof(ts32));
                  if (error)
                          return (error);
                  CP(ts32, ts, tv_sec);
                  CP(ts32, ts, tv_nsec);
                  tsp = &ts;
          } else
                  tsp = NULL;
  
          return (kern_aio_waitcomplete(td, (struct aiocb **)uap->aiocbp, tsp,
              &aiocb32_ops));
  }
  
  int
  freebsd32_aio_fsync(struct thread *td, struct freebsd32_aio_fsync_args *uap)
  {
  
          return (kern_aio_fsync(td, uap->op, (struct aiocb *)uap->aiocbp,
              &aiocb32_ops));
  }
  
  #ifdef COMPAT_FREEBSD6
  int
  freebsd6_freebsd32_lio_listio(struct thread *td,
      struct freebsd6_freebsd32_lio_listio_args *uap)
  {
          struct aiocb **acb_list;
          struct sigevent *sigp, sig;
          struct osigevent32 osig;
          uint32_t *acb_list32;
          int error, i, nent;
  
          if ((uap->mode != LIO_NOWAIT) && (uap->mode != LIO_WAIT))
                  return (EINVAL);
  
          nent = uap->nent;
          if (nent < 0 || nent > max_aio_queue_per_proc)
                  return (EINVAL);
  
          if (uap->sig && (uap->mode == LIO_NOWAIT)) {
                  error = copyin(uap->sig, &osig, sizeof(osig));
                  if (error)
                          return (error);
                  error = convert_old_sigevent32(&osig, &sig);
                  if (error)
                          return (error);
                  sigp = &sig;
          } else
                  sigp = NULL;
  
          acb_list32 = malloc(sizeof(uint32_t) * nent, M_LIO, M_WAITOK);
          error = copyin(uap->acb_list, acb_list32, nent * sizeof(uint32_t));
          if (error) {
                  free(acb_list32, M_LIO);
                  return (error);
          }
          acb_list = malloc(sizeof(struct aiocb *) * nent, M_LIO, M_WAITOK);
          for (i = 0; i < nent; i++)
                  acb_list[i] = PTRIN(acb_list32[i]);
          free(acb_list32, M_LIO);
  
          error = kern_lio_listio(td, uap->mode,
              (struct aiocb * const *)uap->acb_list, acb_list, nent, sigp,
              &aiocb32_ops_osigevent);
          free(acb_list, M_LIO);
          return (error);
  }
  #endif
  
  int
  freebsd32_lio_listio(struct thread *td, struct freebsd32_lio_listio_args *uap)
  {
          struct aiocb **acb_list;
          struct sigevent *sigp, sig;
          struct sigevent32 sig32;
          uint32_t *acb_list32;
          int error, i, nent;
  
          if ((uap->mode != LIO_NOWAIT) && (uap->mode != LIO_WAIT))
                  return (EINVAL);
  
          nent = uap->nent;
          if (nent < 0 || nent > max_aio_queue_per_proc)
                  return (EINVAL);
  
          if (uap->sig && (uap->mode == LIO_NOWAIT)) {
                  error = copyin(uap->sig, &sig32, sizeof(sig32));
                  if (error)
                          return (error);
                  error = convert_sigevent32(&sig32, &sig);
                  if (error)
                          return (error);
                  sigp = &sig;
          } else
                  sigp = NULL;
  
          acb_list32 = malloc(sizeof(uint32_t) * nent, M_LIO, M_WAITOK);
          error = copyin(uap->acb_list, acb_list32, nent * sizeof(uint32_t));
          if (error) {
                  free(acb_list32, M_LIO);
                  return (error);
          }
          acb_list = malloc(sizeof(struct aiocb *) * nent, M_LIO, M_WAITOK);
          for (i = 0; i < nent; i++)
                  acb_list[i] = PTRIN(acb_list32[i]);
          free(acb_list32, M_LIO);
  
          error = kern_lio_listio(td, uap->mode,
              (struct aiocb * const *)uap->acb_list, acb_list, nent, sigp,
              &aiocb32_ops);
          free(acb_list, M_LIO);
          return (error);
  }
  
  #endif

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