xnu-1504.9.26.tar.gz

[apple/xnu.git] / osfmk / vm / bsd_vm.c

/*
 * Copyright (c) 2000-2006 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 * 
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */

#include <sys/errno.h>

#include <mach/mach_types.h>
#include <mach/mach_traps.h>
#include <mach/host_priv.h>
#include <mach/kern_return.h>
#include <mach/memory_object_control.h>
#include <mach/memory_object_types.h>
#include <mach/port.h>
#include <mach/policy.h>
#include <mach/upl.h>
#include <mach/thread_act.h>

#include <kern/assert.h>
#include <kern/host.h>
#include <kern/thread.h>

#include <ipc/ipc_port.h>
#include <ipc/ipc_space.h>

#include <default_pager/default_pager_types.h>
#include <default_pager/default_pager_object_server.h>

#include <vm/vm_map.h>
#include <vm/vm_pageout.h>
#include <vm/memory_object.h>
#include <vm/vm_pageout.h>
#include <vm/vm_protos.h>
#include <vm/vm_purgeable_internal.h>


/* BSD VM COMPONENT INTERFACES */
int
get_map_nentries(
        vm_map_t);

vm_offset_t
get_map_start(
        vm_map_t);

vm_offset_t
get_map_end(
        vm_map_t);

/*
 * 
 */
int
get_map_nentries(
        vm_map_t map)
{
        return(map->hdr.nentries);
}

mach_vm_offset_t
mach_get_vm_start(vm_map_t map)
{
        return( vm_map_first_entry(map)->vme_start);
}

mach_vm_offset_t
mach_get_vm_end(vm_map_t map)
{
        return( vm_map_last_entry(map)->vme_end);
}

/*
 * Legacy routines to get the start and end for a vm_map_t.  They
 * return them in the vm_offset_t format.  So, they should only be
 * called on maps that are the same size as the kernel map for
 * accurate results.
 */
vm_offset_t
get_vm_start(
        vm_map_t map)
{
        return(CAST_DOWN(vm_offset_t, vm_map_first_entry(map)->vme_start));
}

vm_offset_t
get_vm_end(
        vm_map_t map)
{
        return(CAST_DOWN(vm_offset_t, vm_map_last_entry(map)->vme_end));
}

/* 
 * BSD VNODE PAGER 
 */

const struct memory_object_pager_ops vnode_pager_ops = {
        vnode_pager_reference,
        vnode_pager_deallocate,
        vnode_pager_init,
        vnode_pager_terminate,
        vnode_pager_data_request,
        vnode_pager_data_return,
        vnode_pager_data_initialize,
        vnode_pager_data_unlock,
        vnode_pager_synchronize,
        vnode_pager_map,
        vnode_pager_last_unmap,
        "vnode pager"
};

typedef struct vnode_pager {
        struct ipc_object_header        pager_header;   /* fake ip_kotype()             */
        memory_object_pager_ops_t pager_ops;    /* == &vnode_pager_ops       */
        unsigned int            ref_count;      /* reference count           */
        memory_object_control_t control_handle; /* mem object control handle */
        struct vnode            *vnode_handle;  /* vnode handle              */
} *vnode_pager_t;

#define pager_ikot pager_header.io_bits

ipc_port_t
trigger_name_to_port(                   /* forward */
        mach_port_t);

kern_return_t
vnode_pager_cluster_read(               /* forward */
        vnode_pager_t, 
        vm_object_offset_t,
        vm_object_offset_t,
        uint32_t,
        vm_size_t);

void
vnode_pager_cluster_write(              /* forward */
        vnode_pager_t,
        vm_object_offset_t,
        vm_size_t,
        vm_object_offset_t *,
        int *,
        int);


vnode_pager_t
vnode_object_create(                    /* forward */
        struct vnode *);

vnode_pager_t
vnode_pager_lookup(                     /* forward */
        memory_object_t);

zone_t  vnode_pager_zone;


#define VNODE_PAGER_NULL        ((vnode_pager_t) 0)

/* TODO: Should be set dynamically by vnode_pager_init() */
#define CLUSTER_SHIFT   1

/* TODO: Should be set dynamically by vnode_pager_bootstrap() */
#define MAX_VNODE               10000


#if DEBUG
int pagerdebug=0;

#define PAGER_ALL               0xffffffff
#define PAGER_INIT              0x00000001
#define PAGER_PAGEIN    0x00000002

#define PAGER_DEBUG(LEVEL, A) {if ((pagerdebug & LEVEL)==LEVEL){printf A;}}
#else
#define PAGER_DEBUG(LEVEL, A)
#endif

extern int proc_resetpcontrol(int);

#if DEVELOPMENT || DEBUG
extern unsigned long vm_cs_validated_resets;
#endif

/*
 *      Routine:        mach_macx_triggers
 *      Function:
 *              Syscall interface to set the call backs for low and
 *              high water marks.
 */
int
mach_macx_triggers(
        struct macx_triggers_args *args)
{
        int     hi_water = args->hi_water;
        int     low_water = args->low_water;
        int     flags = args->flags;
        mach_port_t     trigger_name = args->alert_port;
        kern_return_t kr;
        memory_object_default_t default_pager;
        ipc_port_t              trigger_port;

        default_pager = MEMORY_OBJECT_DEFAULT_NULL;
        kr = host_default_memory_manager(host_priv_self(), 
                                        &default_pager, 0);
        if(kr != KERN_SUCCESS) {
                return EINVAL;
        }

        if (((flags & SWAP_ENCRYPT_ON) && (flags & SWAP_ENCRYPT_OFF)) || 
            ((flags & SWAP_COMPACT_ENABLE) && (flags & SWAP_COMPACT_DISABLE))) {
                /* can't have it both ways */
                return EINVAL;
        }

        if (default_pager_init_flag == 0) {
               start_def_pager(NULL);
               default_pager_init_flag = 1;
        }

        if (flags & SWAP_ENCRYPT_ON) {
                /* ENCRYPTED SWAP: tell default_pager to encrypt */
                default_pager_triggers(default_pager,
                                       0, 0,
                                       SWAP_ENCRYPT_ON,
                                       IP_NULL);
        } else if (flags & SWAP_ENCRYPT_OFF) {
                /* ENCRYPTED SWAP: tell default_pager not to encrypt */
                default_pager_triggers(default_pager,
                                       0, 0,
                                       SWAP_ENCRYPT_OFF,
                                       IP_NULL);
        }

        if (flags & USE_EMERGENCY_SWAP_FILE_FIRST) {
                /*
                 * Time to switch to the emergency segment.
                 */
                return default_pager_triggers(default_pager,
                                        0, 0, 
                                        USE_EMERGENCY_SWAP_FILE_FIRST,
                                        IP_NULL);
        }

        if (flags & SWAP_FILE_CREATION_ERROR) {
                /* 
                 * For some reason, the dynamic pager failed to create a swap file.
                 */
                trigger_port = trigger_name_to_port(trigger_name);
                if(trigger_port == NULL) {
                        return EINVAL;
                }
                /* trigger_port is locked and active */
                ipc_port_make_send_locked(trigger_port); 
                /* now unlocked */
                default_pager_triggers(default_pager,
                                        0, 0, 
                                        SWAP_FILE_CREATION_ERROR,
                                        trigger_port);
        }

        if (flags & HI_WAT_ALERT) {
                trigger_port = trigger_name_to_port(trigger_name);
                if(trigger_port == NULL) {
                        return EINVAL;
                }
                /* trigger_port is locked and active */
                ipc_port_make_send_locked(trigger_port); 
                /* now unlocked */
                default_pager_triggers(default_pager, 
                                       hi_water, low_water,
                                       HI_WAT_ALERT, trigger_port);
        }

        if (flags & LO_WAT_ALERT) {
                trigger_port = trigger_name_to_port(trigger_name);
                if(trigger_port == NULL) {
                        return EINVAL;
                }
                /* trigger_port is locked and active */
                ipc_port_make_send_locked(trigger_port);
                /* and now its unlocked */
                default_pager_triggers(default_pager, 
                                       hi_water, low_water,
                                       LO_WAT_ALERT, trigger_port);
        }


        if (flags & PROC_RESUME) {

                /*
                 * For this call, hi_water is used to pass in the pid of the process we want to resume
                 * or unthrottle.  This is of course restricted to the superuser (checked inside of 
                 * proc_resetpcontrol).
                 */

                return proc_resetpcontrol(hi_water);
        }

        /*
         * Set thread scheduling priority and policy for the current thread
         * it is assumed for the time being that the thread setting the alert
         * is the same one which will be servicing it.
         *
         * XXX This does not belong in the kernel XXX
         */
        if (flags & HI_WAT_ALERT) {
                thread_precedence_policy_data_t         pre;
                thread_extended_policy_data_t           ext;

                ext.timeshare = FALSE;
                pre.importance = INT32_MAX;

                thread_policy_set(current_thread(),
                                  THREAD_EXTENDED_POLICY,
                                  (thread_policy_t)&ext,
                                  THREAD_EXTENDED_POLICY_COUNT);

                thread_policy_set(current_thread(),
                                  THREAD_PRECEDENCE_POLICY,
                                  (thread_policy_t)&pre,
                                  THREAD_PRECEDENCE_POLICY_COUNT);

                current_thread()->options |= TH_OPT_VMPRIV;
        }
 
        if (flags & (SWAP_COMPACT_DISABLE | SWAP_COMPACT_ENABLE)) {
                return macx_backing_store_compaction(flags & (SWAP_COMPACT_DISABLE | SWAP_COMPACT_ENABLE));
        }

        return 0;
}

/*
 *
 */
ipc_port_t
trigger_name_to_port(
        mach_port_t     trigger_name)
{
        ipc_port_t      trigger_port;
        ipc_space_t     space;

        if (trigger_name == 0)
                return (NULL);

        space  = current_space();
        if(ipc_port_translate_receive(space, CAST_MACH_PORT_TO_NAME(trigger_name), 
                                                &trigger_port) != KERN_SUCCESS)
                return (NULL);
        return trigger_port;
}


extern int      uiomove64(addr64_t, int, void *);
#define MAX_RUN 32

int
memory_object_control_uiomove(
        memory_object_control_t control,
        memory_object_offset_t  offset,
        void            *       uio,
        int                     start_offset,
        int                     io_requested,
        int                     mark_dirty,
        int                     take_reference)
{
        vm_object_t             object;
        vm_page_t               dst_page;
        int                     xsize;
        int                     retval = 0;
        int                     cur_run;
        int                     cur_needed;
        int                     i;
        int                     orig_offset;
        vm_page_t               page_run[MAX_RUN];

        object = memory_object_control_to_vm_object(control);
        if (object == VM_OBJECT_NULL) {
                return (0);
        }
        assert(!object->internal);

        vm_object_lock(object);

        if (mark_dirty && object->copy != VM_OBJECT_NULL) {
                /*
                 * We can't modify the pages without honoring
                 * copy-on-write obligations first, so fall off
                 * this optimized path and fall back to the regular
                 * path.
                 */
                vm_object_unlock(object);
                return 0;
        }
        orig_offset = start_offset;
            
        while (io_requested && retval == 0) {

                cur_needed = (start_offset + io_requested + (PAGE_SIZE - 1)) / PAGE_SIZE;

                if (cur_needed > MAX_RUN)
                        cur_needed = MAX_RUN;

                for (cur_run = 0; cur_run < cur_needed; ) {

                        if ((dst_page = vm_page_lookup(object, offset)) == VM_PAGE_NULL)
                                break;

                        /*
                         * if we're in this routine, we are inside a filesystem's
                         * locking model, so we don't ever want to wait for pages that have
                         * list_req_pending == TRUE since it means that the
                         * page is a candidate for some type of I/O operation,
                         * but that it has not yet been gathered into a UPL...
                         * this implies that it is still outside the domain
                         * of the filesystem and that whoever is responsible for
                         * grabbing it into a UPL may be stuck behind the filesystem
                         * lock this thread owns, or trying to take a lock exclusively
                         * and waiting for the readers to drain from a rw lock...
                         * if we block in those cases, we will deadlock
                         */
                        if (dst_page->list_req_pending) {

                                if (dst_page->absent) {
                                        /*
                                         * this is the list_req_pending | absent | busy case
                                         * which originates from vm_fault_page... we want
                                         * to fall out of the fast path and go back
                                         * to the caller which will gather this page
                                         * into a UPL and issue the I/O if no one
                                         * else beats us to it
                                         */
                                        break;
                                }
                                if (dst_page->pageout || dst_page->cleaning) {
                                        /*
                                         * this is the list_req_pending | pageout | busy case
                                         * or the list_req_pending | cleaning case...
                                         * which originate from the pageout_scan and
                                         * msync worlds for the pageout case and the hibernate
                                         * pre-cleaning world for the cleaning case...
                                         * we need to reset the state of this page to indicate
                                         * it should stay in the cache marked dirty... nothing else we
                                         * can do at this point... we can't block on it, we can't busy
                                         * it and we can't clean it from this routine.
                                         */
                                        vm_page_lockspin_queues();

                                        vm_pageout_queue_steal(dst_page, TRUE); 
                                        vm_page_deactivate(dst_page);

                                        vm_page_unlock_queues();
                                }
                                /*
                                 * this is the list_req_pending | cleaning case...
                                 * we can go ahead and deal with this page since
                                 * its ok for us to mark this page busy... if a UPL
                                 * tries to gather this page, it will block until the
                                 * busy is cleared, thus allowing us safe use of the page
                                 * when we're done with it, we will clear busy and wake
                                 * up anyone waiting on it, thus allowing the UPL creation
                                 * to finish
                                 */

                        } else if (dst_page->busy || dst_page->cleaning) {
                                /*
                                 * someone else is playing with the page... if we've
                                 * already collected pages into this run, go ahead
                                 * and process now, we can't block on this
                                 * page while holding other pages in the BUSY state
                                 * otherwise we will wait
                                 */
                                if (cur_run)
                                        break;
                                PAGE_SLEEP(object, dst_page, THREAD_UNINT);
                                continue;
                        }

                        /*
                         * this routine is only called when copying
                         * to/from real files... no need to consider
                         * encrypted swap pages
                         */
                        assert(!dst_page->encrypted);

                        if (mark_dirty) {
                                dst_page->dirty = TRUE;
                                if (dst_page->cs_validated && 
                                    !dst_page->cs_tainted) {
                                        /*
                                         * CODE SIGNING:
                                         * We're modifying a code-signed
                                         * page: force revalidate
                                         */
                                        dst_page->cs_validated = FALSE;
#if DEVELOPMENT || DEBUG
                                        vm_cs_validated_resets++;
#endif
                                        pmap_disconnect(dst_page->phys_page);
                                }
                        }
                        dst_page->busy = TRUE;

                        page_run[cur_run++] = dst_page;

                        offset += PAGE_SIZE_64;
                }
                if (cur_run == 0)
                        /*
                         * we hit a 'hole' in the cache or
                         * a page we don't want to try to handle,
                         * so bail at this point
                         * we'll unlock the object below
                         */
                        break;
                vm_object_unlock(object);

                for (i = 0; i < cur_run; i++) {
                  
                        dst_page = page_run[i];

                        if ((xsize = PAGE_SIZE - start_offset) > io_requested)
                                xsize = io_requested;

                        if ( (retval = uiomove64((addr64_t)(((addr64_t)(dst_page->phys_page) << 12) + start_offset), xsize, uio)) )
                                break;

                        io_requested -= xsize;
                        start_offset = 0;
                }
                vm_object_lock(object);

                /*
                 * if we have more than 1 page to work on
                 * in the current run, or the original request
                 * started at offset 0 of the page, or we're
                 * processing multiple batches, we will move
                 * the pages to the tail of the inactive queue
                 * to implement an LRU for read/write accesses
                 *
                 * the check for orig_offset == 0 is there to 
                 * mitigate the cost of small (< page_size) requests
                 * to the same page (this way we only move it once)
                 */
                if (take_reference && (cur_run > 1 || orig_offset == 0)) {

                        vm_page_lockspin_queues();

                        for (i = 0; i < cur_run; i++)
                                vm_page_lru(page_run[i]);

                        vm_page_unlock_queues();
                }
                for (i = 0; i < cur_run; i++) {
                        dst_page = page_run[i];

                        /*
                         * someone is explicitly referencing this page...
                         * update clustered and speculative state
                         * 
                         */
                        VM_PAGE_CONSUME_CLUSTERED(dst_page);

                        PAGE_WAKEUP_DONE(dst_page);
                }
                orig_offset = 0;
        }
        vm_object_unlock(object);

        return (retval);
}


/*
 *
 */
void
vnode_pager_bootstrap(void)
{
        register vm_size_t      size;

        size = (vm_size_t) sizeof(struct vnode_pager);
        vnode_pager_zone = zinit(size, (vm_size_t) MAX_VNODE*size,
                                PAGE_SIZE, "vnode pager structures");
        zone_change(vnode_pager_zone, Z_NOENCRYPT, TRUE);

#if CONFIG_CODE_DECRYPTION
        apple_protect_pager_bootstrap();
#endif  /* CONFIG_CODE_DECRYPTION */
        swapfile_pager_bootstrap();
        return;
}

/*
 *
 */
memory_object_t
vnode_pager_setup(
        struct vnode    *vp,
        __unused memory_object_t        pager)
{
        vnode_pager_t   vnode_object;

        vnode_object = vnode_object_create(vp);
        if (vnode_object == VNODE_PAGER_NULL)
                panic("vnode_pager_setup: vnode_object_create() failed");
        return((memory_object_t)vnode_object);
}

/*
 *
 */
kern_return_t
vnode_pager_init(memory_object_t mem_obj, 
                memory_object_control_t control, 
#if !DEBUG
                 __unused
#endif
                 memory_object_cluster_size_t pg_size)
{
        vnode_pager_t   vnode_object;
        kern_return_t   kr;
        memory_object_attr_info_data_t  attributes;


        PAGER_DEBUG(PAGER_ALL, ("vnode_pager_init: %p, %p, %lx\n", mem_obj, control, (unsigned long)pg_size));

        if (control == MEMORY_OBJECT_CONTROL_NULL)
                return KERN_INVALID_ARGUMENT;

        vnode_object = vnode_pager_lookup(mem_obj);

        memory_object_control_reference(control);

        vnode_object->control_handle = control;

        attributes.copy_strategy = MEMORY_OBJECT_COPY_DELAY;
        /* attributes.cluster_size = (1 << (CLUSTER_SHIFT + PAGE_SHIFT));*/
        attributes.cluster_size = (1 << (PAGE_SHIFT));
        attributes.may_cache_object = TRUE;
        attributes.temporary = TRUE;

        kr = memory_object_change_attributes(
                                        control,
                                        MEMORY_OBJECT_ATTRIBUTE_INFO,
                                        (memory_object_info_t) &attributes,
                                        MEMORY_OBJECT_ATTR_INFO_COUNT);
        if (kr != KERN_SUCCESS)
                panic("vnode_pager_init: memory_object_change_attributes() failed");

        return(KERN_SUCCESS);
}

/*
 *
 */
kern_return_t
vnode_pager_data_return(
        memory_object_t         mem_obj,
        memory_object_offset_t  offset,
        memory_object_cluster_size_t            data_cnt,
        memory_object_offset_t  *resid_offset,
        int                     *io_error,
        __unused boolean_t              dirty,
        __unused boolean_t              kernel_copy,
        int                     upl_flags)  
{
        register vnode_pager_t  vnode_object;

        vnode_object = vnode_pager_lookup(mem_obj);

        vnode_pager_cluster_write(vnode_object, offset, data_cnt, resid_offset, io_error, upl_flags);

        return KERN_SUCCESS;
}

kern_return_t
vnode_pager_data_initialize(
        __unused memory_object_t                mem_obj,
        __unused memory_object_offset_t offset,
        __unused memory_object_cluster_size_t           data_cnt)
{
        panic("vnode_pager_data_initialize");
        return KERN_FAILURE;
}

kern_return_t
vnode_pager_data_unlock(
        __unused memory_object_t                mem_obj,
        __unused memory_object_offset_t offset,
        __unused memory_object_size_t           size,
        __unused vm_prot_t              desired_access)
{
        return KERN_FAILURE;
}

kern_return_t
vnode_pager_get_isinuse(
        memory_object_t         mem_obj,
        uint32_t                *isinuse)
{
        vnode_pager_t   vnode_object;

        if (mem_obj->mo_pager_ops != &vnode_pager_ops) {
                *isinuse = 1;
                return KERN_INVALID_ARGUMENT;
        }

        vnode_object = vnode_pager_lookup(mem_obj);

        *isinuse = vnode_pager_isinuse(vnode_object->vnode_handle);
        return KERN_SUCCESS;
}

kern_return_t
vnode_pager_check_hard_throttle(
        memory_object_t         mem_obj,
        uint32_t                *limit,
        uint32_t                hard_throttle)
{
        vnode_pager_t   vnode_object;

        if (mem_obj->mo_pager_ops != &vnode_pager_ops)
                return KERN_INVALID_ARGUMENT;

        vnode_object = vnode_pager_lookup(mem_obj);

        (void)vnode_pager_return_hard_throttle_limit(vnode_object->vnode_handle, limit, hard_throttle);
        return KERN_SUCCESS;
}

kern_return_t
vnode_pager_get_object_size(
        memory_object_t         mem_obj,
        memory_object_offset_t  *length)
{
        vnode_pager_t   vnode_object;

        if (mem_obj->mo_pager_ops != &vnode_pager_ops) {
                *length = 0;
                return KERN_INVALID_ARGUMENT;
        }

        vnode_object = vnode_pager_lookup(mem_obj);

        *length = vnode_pager_get_filesize(vnode_object->vnode_handle);
        return KERN_SUCCESS;
}

kern_return_t
vnode_pager_get_object_pathname(
        memory_object_t         mem_obj,
        char                    *pathname,
        vm_size_t               *length_p)
{
        vnode_pager_t   vnode_object;

        if (mem_obj->mo_pager_ops != &vnode_pager_ops) {
                return KERN_INVALID_ARGUMENT;
        }

        vnode_object = vnode_pager_lookup(mem_obj);

        return vnode_pager_get_pathname(vnode_object->vnode_handle,
                                        pathname,
                                        length_p);
}

kern_return_t
vnode_pager_get_object_filename(
        memory_object_t mem_obj,
        const char      **filename)
{
        vnode_pager_t   vnode_object;

        if (mem_obj->mo_pager_ops != &vnode_pager_ops) {
                return KERN_INVALID_ARGUMENT;
        }

        vnode_object = vnode_pager_lookup(mem_obj);

        return vnode_pager_get_filename(vnode_object->vnode_handle,
                                        filename);
}

kern_return_t
vnode_pager_get_object_cs_blobs(
        memory_object_t mem_obj,
        void            **blobs)
{
        vnode_pager_t   vnode_object;

        if (mem_obj == MEMORY_OBJECT_NULL ||
            mem_obj->mo_pager_ops != &vnode_pager_ops) {
                return KERN_INVALID_ARGUMENT;
        }

        vnode_object = vnode_pager_lookup(mem_obj);

        return vnode_pager_get_cs_blobs(vnode_object->vnode_handle,
                                        blobs);
}

/*
 *
 */
kern_return_t   
vnode_pager_data_request(
        memory_object_t         mem_obj,
        memory_object_offset_t  offset,
        __unused memory_object_cluster_size_t   length,
        __unused vm_prot_t      desired_access,
        memory_object_fault_info_t      fault_info)
{
        vnode_pager_t           vnode_object;
        memory_object_offset_t  base_offset;
        vm_size_t               size;
        uint32_t                io_streaming = 0;

        vnode_object = vnode_pager_lookup(mem_obj);

        size = MAX_UPL_TRANSFER * PAGE_SIZE;
        base_offset = offset;

        if (memory_object_cluster_size(vnode_object->control_handle, &base_offset, &size, &io_streaming, fault_info) != KERN_SUCCESS)
                size = PAGE_SIZE;

        assert(offset >= base_offset &&
               offset < base_offset + size);

        return vnode_pager_cluster_read(vnode_object, base_offset, offset, io_streaming, size);
}

/*
 *
 */
void
vnode_pager_reference(
        memory_object_t         mem_obj)
{       
        register vnode_pager_t  vnode_object;
        unsigned int            new_ref_count;

        vnode_object = vnode_pager_lookup(mem_obj);
        new_ref_count = hw_atomic_add(&vnode_object->ref_count, 1);
        assert(new_ref_count > 1);
}

/*
 *
 */
void
vnode_pager_deallocate(
        memory_object_t         mem_obj)
{
        register vnode_pager_t  vnode_object;

        PAGER_DEBUG(PAGER_ALL, ("vnode_pager_deallocate: %p\n", mem_obj));

        vnode_object = vnode_pager_lookup(mem_obj);

        if (hw_atomic_sub(&vnode_object->ref_count, 1) == 0) {
                if (vnode_object->vnode_handle != NULL) {
                        vnode_pager_vrele(vnode_object->vnode_handle);
                }
                zfree(vnode_pager_zone, vnode_object);
        }
        return;
}

/*
 *
 */
kern_return_t
vnode_pager_terminate(
#if !DEBUG
        __unused
#endif
        memory_object_t mem_obj)
{
        PAGER_DEBUG(PAGER_ALL, ("vnode_pager_terminate: %p\n", mem_obj));

        return(KERN_SUCCESS);
}

/*
 *
 */
kern_return_t
vnode_pager_synchronize(
        memory_object_t         mem_obj,
        memory_object_offset_t  offset,
        memory_object_size_t            length,
        __unused vm_sync_t              sync_flags)
{
        register vnode_pager_t  vnode_object;

        PAGER_DEBUG(PAGER_ALL, ("vnode_pager_synchronize: %p\n", mem_obj));

        vnode_object = vnode_pager_lookup(mem_obj);

        memory_object_synchronize_completed(vnode_object->control_handle, offset, length);

        return (KERN_SUCCESS);
}

/*
 *
 */
kern_return_t
vnode_pager_map(
        memory_object_t         mem_obj,
        vm_prot_t               prot)
{
        vnode_pager_t           vnode_object;
        int                     ret;
        kern_return_t           kr;

        PAGER_DEBUG(PAGER_ALL, ("vnode_pager_map: %p %x\n", mem_obj, prot));

        vnode_object = vnode_pager_lookup(mem_obj);

        ret = ubc_map(vnode_object->vnode_handle, prot);

        if (ret != 0) {
                kr = KERN_FAILURE;
        } else {
                kr = KERN_SUCCESS;
        }

        return kr;
}

kern_return_t
vnode_pager_last_unmap(
        memory_object_t         mem_obj)
{
        register vnode_pager_t  vnode_object;

        PAGER_DEBUG(PAGER_ALL, ("vnode_pager_last_unmap: %p\n", mem_obj));

        vnode_object = vnode_pager_lookup(mem_obj);

        ubc_unmap(vnode_object->vnode_handle);
        return KERN_SUCCESS;
}



/*
 *
 */
void
vnode_pager_cluster_write(
        vnode_pager_t           vnode_object,
        vm_object_offset_t      offset,
        vm_size_t               cnt,
        vm_object_offset_t   *  resid_offset,
        int                  *  io_error,
        int                     upl_flags)
{
        vm_size_t       size;
        int             errno;

        if (upl_flags & UPL_MSYNC) {

                upl_flags |= UPL_VNODE_PAGER;

                if ( (upl_flags & UPL_IOSYNC) && io_error)
                        upl_flags |= UPL_KEEPCACHED;

                while (cnt) {
                        size = (cnt < (PAGE_SIZE * MAX_UPL_TRANSFER)) ? cnt : (PAGE_SIZE * MAX_UPL_TRANSFER); /* effective max */

                        assert((upl_size_t) size == size);
                        vnode_pageout(vnode_object->vnode_handle, 
                                      NULL, (upl_offset_t)0, offset, (upl_size_t)size, upl_flags, &errno);

                        if ( (upl_flags & UPL_KEEPCACHED) ) {
                                if ( (*io_error = errno) )
                                        break;
                        }
                        cnt    -= size;
                        offset += size;
                }
                if (resid_offset)
                        *resid_offset = offset;

        } else {
                vm_object_offset_t      vnode_size;
                vm_object_offset_t      base_offset;

                /*
                 * this is the pageout path
                 */
                vnode_size = vnode_pager_get_filesize(vnode_object->vnode_handle);

                if (vnode_size > (offset + PAGE_SIZE)) {
                        /*
                         * preset the maximum size of the cluster
                         * and put us on a nice cluster boundary...
                         * and then clip the size to insure we
                         * don't request past the end of the underlying file
                         */
                        size = PAGE_SIZE * MAX_UPL_TRANSFER;
                        base_offset = offset & ~((signed)(size - 1));

                        if ((base_offset + size) > vnode_size)
                                size = round_page(((vm_size_t)(vnode_size - base_offset)));
                } else {
                        /*
                         * we've been requested to page out a page beyond the current
                         * end of the 'file'... don't try to cluster in this case...
                         * we still need to send this page through because it might
                         * be marked precious and the underlying filesystem may need
                         * to do something with it (besides page it out)...
                         */
                        base_offset = offset;
                        size = PAGE_SIZE;
                }
                assert((upl_size_t) size == size);
                vnode_pageout(vnode_object->vnode_handle,
                              NULL, (upl_offset_t)(offset - base_offset), base_offset, (upl_size_t) size, UPL_VNODE_PAGER, NULL);
        }
}


/*
 *
 */
kern_return_t
vnode_pager_cluster_read(
        vnode_pager_t           vnode_object,
        vm_object_offset_t      base_offset,
        vm_object_offset_t      offset,
        uint32_t                io_streaming,
        vm_size_t               cnt)
{
        int             local_error = 0;
        int             kret;
        int             flags = 0;

        assert(! (cnt & PAGE_MASK));

        if (io_streaming)
                flags |= UPL_IOSTREAMING;

        assert((upl_size_t) cnt == cnt);
        kret = vnode_pagein(vnode_object->vnode_handle,
                            (upl_t) NULL,
                            (upl_offset_t) (offset - base_offset),
                            base_offset,
                            (upl_size_t) cnt,
                            flags,
                            &local_error);
/*
        if(kret == PAGER_ABSENT) {
        Need to work out the defs here, 1 corresponds to PAGER_ABSENT 
        defined in bsd/vm/vm_pager.h  However, we should not be including 
        that file here it is a layering violation.
*/
        if (kret == 1) {
                int     uplflags;
                upl_t   upl = NULL;
                unsigned int    count = 0;
                kern_return_t   kr;

                uplflags = (UPL_NO_SYNC |
                            UPL_CLEAN_IN_PLACE |
                            UPL_SET_INTERNAL);
                count = 0;
                assert((upl_size_t) cnt == cnt);
                kr = memory_object_upl_request(vnode_object->control_handle,
                                               base_offset, (upl_size_t) cnt,
                                               &upl, NULL, &count, uplflags);
                if (kr == KERN_SUCCESS) {
                        upl_abort(upl, 0);
                        upl_deallocate(upl);
                } else {
                        /*
                         * We couldn't gather the page list, probably
                         * because the memory object doesn't have a link
                         * to a VM object anymore (forced unmount, for
                         * example).  Just return an error to the vm_fault()
                         * path and let it handle it.
                         */
                }

                return KERN_FAILURE;
        }

        return KERN_SUCCESS;

}


/*
 *
 */
void
vnode_pager_release_from_cache(
                int     *cnt)
{
        memory_object_free_from_cache(
                        &realhost, &vnode_pager_ops, cnt);
}

/*
 *
 */
vnode_pager_t
vnode_object_create(
        struct vnode *vp)
{
        register vnode_pager_t  vnode_object;

        vnode_object = (struct vnode_pager *) zalloc(vnode_pager_zone);
        if (vnode_object == VNODE_PAGER_NULL)
                return(VNODE_PAGER_NULL);

        /*
         * The vm_map call takes both named entry ports and raw memory
         * objects in the same parameter.  We need to make sure that
         * vm_map does not see this object as a named entry port.  So,
         * we reserve the first word in the object for a fake ip_kotype
         * setting - that will tell vm_map to use it as a memory object.
         */
        vnode_object->pager_ops = &vnode_pager_ops;
        vnode_object->pager_ikot = IKOT_MEMORY_OBJECT;
        vnode_object->ref_count = 1;
        vnode_object->control_handle = MEMORY_OBJECT_CONTROL_NULL;
        vnode_object->vnode_handle = vp;

        return(vnode_object);
}

/*
 *
 */
vnode_pager_t
vnode_pager_lookup(
        memory_object_t  name)
{
        vnode_pager_t   vnode_object;

        vnode_object = (vnode_pager_t)name;
        assert(vnode_object->pager_ops == &vnode_pager_ops);
        return (vnode_object);
}


/*********************** proc_info implementation *************/

#include <sys/bsdtask_info.h>

static int fill_vnodeinfoforaddr( vm_map_entry_t entry, uintptr_t * vnodeaddr, uint32_t * vid);


int
fill_procregioninfo(task_t task, uint64_t arg, struct proc_regioninfo_internal *pinfo, uintptr_t *vnodeaddr, uint32_t  *vid)
{

        vm_map_t map;
        vm_map_offset_t address = (vm_map_offset_t )arg;
        vm_map_entry_t          tmp_entry;
        vm_map_entry_t          entry;
        vm_map_offset_t         start;
        vm_region_extended_info_data_t extended;
        vm_region_top_info_data_t top;

            task_lock(task);
            map = task->map;
            if (map == VM_MAP_NULL) 
            {
                        task_unlock(task);
                        return(0);
            }
            vm_map_reference(map); 
            task_unlock(task);
            
            vm_map_lock_read(map);

            start = address;
            if (!vm_map_lookup_entry(map, start, &tmp_entry)) {
                if ((entry = tmp_entry->vme_next) == vm_map_to_entry(map)) {
                        vm_map_unlock_read(map);
                        vm_map_deallocate(map); 
                        return(0);
                }
            } else {
                entry = tmp_entry;
            }

            start = entry->vme_start;

            pinfo->pri_offset = entry->offset;
            pinfo->pri_protection = entry->protection;
            pinfo->pri_max_protection = entry->max_protection;
            pinfo->pri_inheritance = entry->inheritance;
            pinfo->pri_behavior = entry->behavior;
            pinfo->pri_user_wired_count = entry->user_wired_count;
            pinfo->pri_user_tag = entry->alias;

            if (entry->is_sub_map) {
                pinfo->pri_flags |= PROC_REGION_SUBMAP;
            } else {
                if (entry->is_shared)
                        pinfo->pri_flags |= PROC_REGION_SHARED;
            }


            extended.protection = entry->protection;
            extended.user_tag = entry->alias;
            extended.pages_resident = 0;
            extended.pages_swapped_out = 0;
            extended.pages_shared_now_private = 0;
            extended.pages_dirtied = 0;
            extended.external_pager = 0;
            extended.shadow_depth = 0;

            vm_map_region_walk(map, start, entry, entry->offset, entry->vme_end - start, &extended);

            if (extended.external_pager && extended.ref_count == 2 && extended.share_mode == SM_SHARED)
                    extended.share_mode = SM_PRIVATE;

            top.private_pages_resident = 0;
            top.shared_pages_resident = 0;
            vm_map_region_top_walk(entry, &top);

        
            pinfo->pri_pages_resident = extended.pages_resident;
            pinfo->pri_pages_shared_now_private = extended.pages_shared_now_private;
            pinfo->pri_pages_swapped_out = extended.pages_swapped_out;
            pinfo->pri_pages_dirtied = extended.pages_dirtied;
            pinfo->pri_ref_count = extended.ref_count;
            pinfo->pri_shadow_depth = extended.shadow_depth;
            pinfo->pri_share_mode = extended.share_mode;

            pinfo->pri_private_pages_resident = top.private_pages_resident;
            pinfo->pri_shared_pages_resident = top.shared_pages_resident;
            pinfo->pri_obj_id = top.obj_id;
                
            pinfo->pri_address = (uint64_t)start;
            pinfo->pri_size = (uint64_t)(entry->vme_end - start);
            pinfo->pri_depth = 0;
        
            if ((vnodeaddr != 0) && (entry->is_sub_map == 0)) {
                *vnodeaddr = (uintptr_t)0;

                if (fill_vnodeinfoforaddr(entry, vnodeaddr, vid) ==0) {
                        vm_map_unlock_read(map);
                        vm_map_deallocate(map); 
                        return(1);
                }
            }

            vm_map_unlock_read(map);
            vm_map_deallocate(map); 
            return(1);
}

static int
fill_vnodeinfoforaddr(
        vm_map_entry_t                  entry,
        uintptr_t * vnodeaddr,
        uint32_t * vid)
{
        vm_object_t     top_object, object;
        memory_object_t memory_object;
        memory_object_pager_ops_t pager_ops;
        kern_return_t   kr;
        int             shadow_depth;


        if (entry->is_sub_map) {
                return(0);
        } else {
                /*
                 * The last object in the shadow chain has the
                 * relevant pager information.
                 */
                top_object = entry->object.vm_object;
                if (top_object == VM_OBJECT_NULL) {
                        object = VM_OBJECT_NULL;
                        shadow_depth = 0;
                } else {
                        vm_object_lock(top_object);
                        for (object = top_object, shadow_depth = 0;
                             object->shadow != VM_OBJECT_NULL;
                             object = object->shadow, shadow_depth++) {
                                vm_object_lock(object->shadow);
                                vm_object_unlock(object);
                        }
                }
        }

        if (object == VM_OBJECT_NULL) {
                return(0);
        } else if (object->internal) {
                vm_object_unlock(object);
                return(0);
        } else if (! object->pager_ready ||
                   object->terminating ||
                   ! object->alive) {
                vm_object_unlock(object);
                return(0);
        } else {
                memory_object = object->pager;
                pager_ops = memory_object->mo_pager_ops;
                if (pager_ops == &vnode_pager_ops) {
                        kr = vnode_pager_get_object_vnode(
                                memory_object,
                                vnodeaddr, vid);
                        if (kr != KERN_SUCCESS) {
                                vm_object_unlock(object);
                                return(0);
                        }
                } else {
                        vm_object_unlock(object);
                        return(0);
                }
        }
        vm_object_unlock(object);
        return(1);
}

kern_return_t 
vnode_pager_get_object_vnode (
        memory_object_t         mem_obj,
        uintptr_t * vnodeaddr,
        uint32_t * vid)
{
        vnode_pager_t   vnode_object;

        vnode_object = vnode_pager_lookup(mem_obj);
        if (vnode_object->vnode_handle)  {
                *vnodeaddr = (uintptr_t)vnode_object->vnode_handle;
                *vid = (uint32_t)vnode_vid((void *)vnode_object->vnode_handle); 

                return(KERN_SUCCESS);
        }
        
        return(KERN_FAILURE);
}


/*
 * Find the underlying vnode object for the given vm_map_entry.  If found, return with the
 * object locked, otherwise return NULL with nothing locked.
 */

vm_object_t
find_vnode_object(
        vm_map_entry_t  entry
)
{
        vm_object_t                     top_object, object;
        memory_object_t                 memory_object;
        memory_object_pager_ops_t       pager_ops;

        if (!entry->is_sub_map) {

                /*
                 * The last object in the shadow chain has the
                 * relevant pager information.
                 */

                top_object = entry->object.vm_object;

                if (top_object) {
                        vm_object_lock(top_object);

                        for (object = top_object; object->shadow != VM_OBJECT_NULL; object = object->shadow) {
                                vm_object_lock(object->shadow);
                                vm_object_unlock(object);
                        }

                        if (object && !object->internal && object->pager_ready && !object->terminating &&
                            object->alive) {
                                memory_object = object->pager;
                                pager_ops = memory_object->mo_pager_ops;

                                /*
                                 * If this object points to the vnode_pager_ops, then we found what we're
                                 * looking for.  Otherwise, this vm_map_entry doesn't have an underlying
                                 * vnode and so we fall through to the bottom and return NULL.
                                 */

                                if (pager_ops == &vnode_pager_ops) 
                                        return object;          /* we return with the object locked */
                        }

                        vm_object_unlock(object);
                }

        }

        return(VM_OBJECT_NULL);
}