kern_symfile.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
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 * 
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 */
/* Copyright (c) 1998 Apple Computer, Inc.  All rights reserved.
 *
 *	File:	bsd/kern/kern_symfile.c
 *
 * HISTORY
 */

#include <mach/vm_param.h>

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/signalvar.h>
#include <sys/resourcevar.h>
#include <sys/namei.h>
#include <sys/vnode_internal.h>
#include <sys/proc_internal.h>
#include <sys/kauth.h>
#include <sys/timeb.h>
#include <sys/times.h>
#include <sys/acct.h>
#include <sys/file_internal.h>
#include <sys/uio.h>
#include <sys/kernel.h>
#include <sys/stat.h>
#include <sys/disk.h>
#include <sys/conf.h>
#include <sys/content_protection.h>

#include <mach-o/loader.h>
#include <mach-o/nlist.h>

#include <kern/kalloc.h>
#include <vm/vm_kern.h>
#include <pexpert/pexpert.h>
#include <IOKit/IOPolledInterface.h>

/* This function is called from kern_sysctl in the current process context;
 * it is exported with the System6.0.exports, but this appears to be a legacy
 * export, as there are no internal consumers.
 */
int
get_kernel_symfile(__unused proc_t p, __unused char const **symfile);
int
get_kernel_symfile(__unused proc_t p, __unused char const **symfile)
{
    return KERN_FAILURE;
}

struct kern_direct_file_io_ref_t
{
    vfs_context_t  ctx;
    struct vnode * vp;
    dev_t          device;
    uint32_t	   blksize;
    off_t          filelength;
    char           cf;
    char           pinned;
};


static int file_ioctl(void * p1, void * p2, u_long theIoctl, caddr_t result)
{
    dev_t device = *(dev_t*) p1;

    return ((*bdevsw[major(device)].d_ioctl)
		    (device, theIoctl, result, S_IFBLK, p2));
}

static int device_ioctl(void * p1, __unused void * p2, u_long theIoctl, caddr_t result)
{
    return (VNOP_IOCTL(p1, theIoctl, result, 0, p2));
}

static int
kern_ioctl_file_extents(struct kern_direct_file_io_ref_t * ref, u_long theIoctl, off_t offset, off_t end)
{
    int error = 0;
    int (*do_ioctl)(void * p1, void * p2, u_long theIoctl, caddr_t result);
    void * p1;
    void * p2;
    uint64_t    fileblk;
    size_t      filechunk;
    dk_extent_t  extent;
    dk_unmap_t   unmap;
    _dk_cs_pin_t pin;

    bzero(&extent, sizeof(dk_extent_t));
    bzero(&unmap, sizeof(dk_unmap_t));
    bzero(&pin, sizeof(pin));
    if (ref->vp->v_type == VREG)
    {
	 p1 = &ref->device;
	 p2 = kernproc;
	 do_ioctl = &file_ioctl;
    }
    else
    {
	/* Partition. */
	p1 = ref->vp;
	p2 = ref->ctx;
	do_ioctl = &device_ioctl;
    }

    if (_DKIOCCSPINEXTENT == theIoctl) {
	    /* Tell CS the image size, so it knows whether to place the subsequent pins SSD/HDD */
	    pin.cp_extent.length = end;
	    pin.cp_flags = _DKIOCCSHIBERNATEIMGSIZE;
	    (void) do_ioctl(p1, p2, _DKIOCCSPINEXTENT, (caddr_t)&pin);
    } else if (_DKIOCCSUNPINEXTENT == theIoctl) {
	    /* Tell CS hibernation is done, so it can stop blocking overlapping writes */
	    pin.cp_flags = _DKIOCCSPINDISCARDBLACKLIST;
	    (void) do_ioctl(p1, p2, _DKIOCCSUNPINEXTENT, (caddr_t)&pin);
    }

    for (; offset < end; offset += filechunk)
    {
        if (ref->vp->v_type == VREG)
        {
            daddr64_t blkno;
	    filechunk = 1*1024*1024*1024;
	    if (filechunk > (size_t)(end - offset))
	    filechunk = (size_t)(end - offset);
            error = VNOP_BLOCKMAP(ref->vp, offset, filechunk, &blkno,
								  &filechunk, NULL, VNODE_WRITE | VNODE_BLOCKMAP_NO_TRACK, NULL);
            if (error) break;
            if (-1LL == blkno) continue;
            fileblk = blkno * ref->blksize;
        }
        else if ((ref->vp->v_type == VBLK) || (ref->vp->v_type == VCHR))
        {
            fileblk = offset;
            filechunk = ref->filelength;
        }

	if (DKIOCUNMAP == theIoctl)
	{
	    extent.offset = fileblk;
	    extent.length = filechunk;
	    unmap.extents = &extent;
	    unmap.extentsCount = 1;
	    error = do_ioctl(p1, p2, theIoctl, (caddr_t)&unmap);
// 	    printf("DKIOCUNMAP(%d) 0x%qx, 0x%qx\n", error, extent.offset, extent.length);
	}
	else if (_DKIOCCSPINEXTENT == theIoctl)
	{
	    pin.cp_extent.offset = fileblk;
	    pin.cp_extent.length = filechunk;
	    pin.cp_flags = _DKIOCCSPINFORHIBERNATION;
	    error = do_ioctl(p1, p2, theIoctl, (caddr_t)&pin);
	    if (error && (ENOTTY != error))
	    {
		printf("_DKIOCCSPINEXTENT(%d) 0x%qx, 0x%qx\n", error, pin.cp_extent.offset, pin.cp_extent.length);
	    }
	}
	else if (_DKIOCCSUNPINEXTENT == theIoctl)
	{
	    pin.cp_extent.offset = fileblk;
	    pin.cp_extent.length = filechunk;
	    pin.cp_flags = _DKIOCCSPINFORHIBERNATION;
	    error = do_ioctl(p1, p2, theIoctl, (caddr_t)&pin);
	    if (error && (ENOTTY != error))
	    {
		printf("_DKIOCCSUNPINEXTENT(%d) 0x%qx, 0x%qx\n", error, pin.cp_extent.offset, pin.cp_extent.length);
	    }
	}
	else error = EINVAL;

        if (error) break;
    }
    return (error);
}

extern uint32_t freespace_mb(vnode_t vp);

struct kern_direct_file_io_ref_t *
kern_open_file_for_direct_io(const char * name, 
			     boolean_t create_file,
			     kern_get_file_extents_callback_t callback, 
			     void * callback_ref,
                             off_t set_file_size,
                             off_t fs_free_size,
                             off_t write_file_offset,
                             void * write_file_addr,
                             size_t write_file_len,
			     dev_t * partition_device_result,
			     dev_t * image_device_result,
                             uint64_t * partitionbase_result,
                             uint64_t * maxiocount_result,
                             uint32_t * oflags)
{
    struct kern_direct_file_io_ref_t * ref;

    proc_t            p;
    struct vnode_attr va;
    int               error;
    off_t             f_offset;
    uint64_t          fileblk;
    size_t            filechunk;
    uint64_t          physoffset;
    dev_t             device;
    dev_t             target = 0;
    int               isssd = 0;
    uint32_t          flags = 0;
    uint32_t          blksize;
    off_t             maxiocount, count, segcount;
    boolean_t         locked = FALSE;
    int               fmode, cmode;
    struct            nameidata nd;
    u_int32_t         ndflags;
    off_t             mpFree;

    int (*do_ioctl)(void * p1, void * p2, u_long theIoctl, caddr_t result);
    void * p1 = NULL;
    void * p2 = NULL;

    error = EFAULT;

    ref = (struct kern_direct_file_io_ref_t *) kalloc(sizeof(struct kern_direct_file_io_ref_t));
    if (!ref)
    {
	error = EFAULT;
    	goto out;
    }

    bzero(ref, sizeof(*ref));
    p = kernproc;
    ref->ctx = vfs_context_kernel();

    fmode  = (create_file) ? (O_CREAT | FWRITE) : FWRITE;
    cmode =  S_IRUSR | S_IWUSR;
    ndflags = NOFOLLOW;
    NDINIT(&nd, LOOKUP, OP_OPEN, ndflags, UIO_SYSSPACE, CAST_USER_ADDR_T(name), ref->ctx);
    VATTR_INIT(&va);
    VATTR_SET(&va, va_mode, cmode);
    VATTR_SET(&va, va_dataprotect_flags, VA_DP_RAWENCRYPTED);
    VATTR_SET(&va, va_dataprotect_class, PROTECTION_CLASS_D);
    if ((error = vn_open_auth(&nd, &fmode, &va))) {
	kprintf("vn_open_auth(fmode: %d, cmode: %d) failed with error: %d\n", fmode, cmode, error);
	goto out;
    }

    ref->vp = nd.ni_vp;
    if (ref->vp->v_type == VREG)
    {
        vnode_lock_spin(ref->vp);
        SET(ref->vp->v_flag, VSWAP);
        vnode_unlock(ref->vp);
    }

    if (write_file_addr && write_file_len)
    {
	if ((error = kern_write_file(ref, write_file_offset, write_file_addr, write_file_len, IO_SKIP_ENCRYPTION))) {
		kprintf("kern_write_file() failed with error: %d\n", error);
		goto out;
	}
    }

    VATTR_INIT(&va);
    VATTR_WANTED(&va, va_rdev);
    VATTR_WANTED(&va, va_fsid);
    VATTR_WANTED(&va, va_devid);
    VATTR_WANTED(&va, va_data_size);
    VATTR_WANTED(&va, va_data_alloc);
    VATTR_WANTED(&va, va_nlink);
    error = EFAULT;
    if (vnode_getattr(ref->vp, &va, ref->ctx)) goto out;

    mpFree = freespace_mb(ref->vp);
    mpFree <<= 20;
    kprintf("kern_direct_file(%s): vp size %qd, alloc %qd, mp free %qd, keep free %qd\n", 
    		name, va.va_data_size, va.va_data_alloc, mpFree, fs_free_size);

    if (ref->vp->v_type == VREG)
    {
        /* Don't dump files with links. */
        if (va.va_nlink != 1) goto out;

        device = (VATTR_IS_SUPPORTED(&va, va_devid)) ? va.va_devid : va.va_fsid;
        ref->filelength = va.va_data_size;

        p1 = &device;
        p2 = p;
        do_ioctl = &file_ioctl;

        if (set_file_size)
        {
            if (fs_free_size)
            {
		mpFree += va.va_data_alloc;
		if ((mpFree < set_file_size) || ((mpFree - set_file_size) < fs_free_size))
		{
		    error = ENOSPC;
		    goto out;
		}
	    }
	    error = vnode_setsize(ref->vp, set_file_size, IO_NOZEROFILL | IO_NOAUTH, ref->ctx);
	    if (error) goto out;
	    ref->filelength = set_file_size;
        }
    }
    else if ((ref->vp->v_type == VBLK) || (ref->vp->v_type == VCHR))
    {
	/* Partition. */
        device = va.va_rdev;

        p1 = ref->vp;
        p2 = ref->ctx;
        do_ioctl = &device_ioctl;
    }
    else
    {
	/* Don't dump to non-regular files. */
        error = EFAULT;
        goto out;
    }
    ref->device = device;

    // probe for CF
    dk_corestorage_info_t cs_info;
    memset(&cs_info, 0, sizeof(dk_corestorage_info_t));
    error = do_ioctl(p1, p2, DKIOCCORESTORAGE, (caddr_t)&cs_info);
    ref->cf = (error == 0) && (cs_info.flags & DK_CORESTORAGE_ENABLE_HOTFILES);

    // get block size

    error = do_ioctl(p1, p2, DKIOCGETBLOCKSIZE, (caddr_t) &ref->blksize);
    if (error)
        goto out;

    if (ref->vp->v_type != VREG)
    {
        error = do_ioctl(p1, p2, DKIOCGETBLOCKCOUNT, (caddr_t) &fileblk);
        if (error) goto out;
	ref->filelength = fileblk * ref->blksize;    
    }

    // pin logical extents

    error = kern_ioctl_file_extents(ref, _DKIOCCSPINEXTENT, 0, ref->filelength);
    if (error && (ENOTTY != error)) goto out;
    ref->pinned = (error == 0);

    // generate the block list

    error = do_ioctl(p1, p2, DKIOCLOCKPHYSICALEXTENTS, NULL);
    if (error) goto out;
    locked = TRUE;

    f_offset = 0;
    for (; f_offset < ref->filelength; f_offset += filechunk)
    {
        if (ref->vp->v_type == VREG)
        {
            filechunk = 1*1024*1024*1024;
            daddr64_t blkno;

            error = VNOP_BLOCKMAP(ref->vp, f_offset, filechunk, &blkno,
								  &filechunk, NULL, VNODE_WRITE | VNODE_BLOCKMAP_NO_TRACK, NULL);
            if (error) goto out;
            if (-1LL == blkno) continue;
            fileblk = blkno * ref->blksize;
        }
        else if ((ref->vp->v_type == VBLK) || (ref->vp->v_type == VCHR))
        {
            fileblk = f_offset;
            filechunk = f_offset ? 0 : ref->filelength;
        }

        physoffset = 0;
        while (physoffset < filechunk)
        {
            dk_physical_extent_t getphysreq;
            bzero(&getphysreq, sizeof(getphysreq));

            getphysreq.offset = fileblk + physoffset;
            getphysreq.length = (filechunk - physoffset);
            error = do_ioctl(p1, p2, DKIOCGETPHYSICALEXTENT, (caddr_t) &getphysreq);
            if (error) goto out;
            if (!target)
            {
                target = getphysreq.dev;
            }
            else if (target != getphysreq.dev)
            {
                error = ENOTSUP;
                goto out;
            }
#if HIBFRAGMENT
	    uint64_t rev;
	    for (rev = 4096; rev <= getphysreq.length; rev += 4096)
	    {
		callback(callback_ref, getphysreq.offset + getphysreq.length - rev, 4096);
	    }
#else
            callback(callback_ref, getphysreq.offset, getphysreq.length);
#endif
            physoffset += getphysreq.length;
        }
    }
    callback(callback_ref, 0ULL, 0ULL);

    if (ref->vp->v_type == VREG) p1 = &target;
    else
    {
	p1 = &target;
	p2 = p;
	do_ioctl = &file_ioctl;
    }

    // get partition base

    if (partitionbase_result) 
    {
        error = do_ioctl(p1, p2, DKIOCGETBASE, (caddr_t) partitionbase_result);
        if (error)
            goto out;
    }

    // get block size & constraints

    error = do_ioctl(p1, p2, DKIOCGETBLOCKSIZE, (caddr_t) &blksize);
    if (error)
        goto out;

    maxiocount = 1*1024*1024*1024;

    error = do_ioctl(p1, p2, DKIOCGETMAXBLOCKCOUNTREAD, (caddr_t) &count);
    if (error)
        count = 0;
    count *= blksize;
    if (count && (count < maxiocount))
        maxiocount = count;

    error = do_ioctl(p1, p2, DKIOCGETMAXBLOCKCOUNTWRITE, (caddr_t) &count);
    if (error)
        count = 0;
    count *= blksize;
    if (count && (count < maxiocount))
        maxiocount = count;

    error = do_ioctl(p1, p2, DKIOCGETMAXBYTECOUNTREAD, (caddr_t) &count);
    if (error)
        count = 0;
    if (count && (count < maxiocount))
        maxiocount = count;

    error = do_ioctl(p1, p2, DKIOCGETMAXBYTECOUNTWRITE, (caddr_t) &count);
    if (error)
        count = 0;
    if (count && (count < maxiocount))
        maxiocount = count;

    error = do_ioctl(p1, p2, DKIOCGETMAXSEGMENTBYTECOUNTREAD, (caddr_t) &count);
    if (!error)
	error = do_ioctl(p1, p2, DKIOCGETMAXSEGMENTCOUNTREAD, (caddr_t) &segcount);
    if (error)
        count = segcount = 0;
    count *= segcount;
    if (count && (count < maxiocount))
        maxiocount = count;

    error = do_ioctl(p1, p2, DKIOCGETMAXSEGMENTBYTECOUNTWRITE, (caddr_t) &count);
    if (!error)
	error = do_ioctl(p1, p2, DKIOCGETMAXSEGMENTCOUNTWRITE, (caddr_t) &segcount);
    if (error)
        count = segcount = 0;
    count *= segcount;
    if (count && (count < maxiocount))
        maxiocount = count;

    kprintf("max io 0x%qx bytes\n", maxiocount);
    if (maxiocount_result)
        *maxiocount_result = maxiocount;

    error = do_ioctl(p1, p2, DKIOCISSOLIDSTATE, (caddr_t)&isssd);
    if (!error && isssd)
        flags |= kIOPolledFileSSD;

    if (partition_device_result)
        *partition_device_result = device;
    if (image_device_result)
        *image_device_result = target;
    if (oflags)
        *oflags = flags;

    if ((ref->vp->v_type == VBLK) || (ref->vp->v_type == VCHR))
    {
        vnode_close(ref->vp, FWRITE, ref->ctx);
        ref->vp = NULLVP;
	ref->ctx = NULL;
    }

out:
    printf("kern_open_file_for_direct_io(%p, %d)\n", ref, error);


    if (error && locked)
    {
        p1 = &device;
        (void) do_ioctl(p1, p2, DKIOCUNLOCKPHYSICALEXTENTS, NULL);
    }

    if (error && ref)
    {
	if (ref->vp)
	{
	    (void) kern_ioctl_file_extents(ref, _DKIOCCSUNPINEXTENT, 0, (ref->pinned && ref->cf) ? ref->filelength : 0);
	    vnode_close(ref->vp, FWRITE, ref->ctx);
	    ref->vp = NULLVP;
	}
	ref->ctx = NULL;
	kfree(ref, sizeof(struct kern_direct_file_io_ref_t));
	ref = NULL;
    }

    return(ref);
}

int
kern_write_file(struct kern_direct_file_io_ref_t * ref, off_t offset, void * addr, size_t len, int ioflag)
{
    return (vn_rdwr(UIO_WRITE, ref->vp,
			addr, len, offset,
			UIO_SYSSPACE, ioflag|IO_SYNC|IO_NODELOCKED|IO_UNIT, 
                        vfs_context_ucred(ref->ctx), (int *) 0,
			vfs_context_proc(ref->ctx)));
}

int
kern_read_file(struct kern_direct_file_io_ref_t * ref, off_t offset, void * addr, size_t len, int ioflag)
{
    return (vn_rdwr(UIO_READ, ref->vp,
			addr, len, offset,
			UIO_SYSSPACE, ioflag|IO_SYNC|IO_NODELOCKED|IO_UNIT, 
                        vfs_context_ucred(ref->ctx), (int *) 0,
			vfs_context_proc(ref->ctx)));
}


struct mount *
kern_file_mount(struct kern_direct_file_io_ref_t * ref)
{
    return (ref->vp->v_mount);
}

void
kern_close_file_for_direct_io(struct kern_direct_file_io_ref_t * ref,
			      off_t write_offset, void * addr, size_t write_length,
			      off_t discard_offset, off_t discard_end)
{
    int error;
    printf("kern_close_file_for_direct_io(%p)\n", ref);

    if (!ref) return;

    if (ref->vp)
    {
        int (*do_ioctl)(void * p1, void * p2, u_long theIoctl, caddr_t result);
        void * p1;
        void * p2;

        if (ref->vp->v_type == VREG)
        {
            p1 = &ref->device;
            p2 = kernproc;
            do_ioctl = &file_ioctl;
        }
        else
        {
            /* Partition. */
            p1 = ref->vp;
            p2 = ref->ctx;
            do_ioctl = &device_ioctl;
        }
        (void) do_ioctl(p1, p2, DKIOCUNLOCKPHYSICALEXTENTS, NULL);

		//XXX If unmapping extents then don't also need to unpin; except ...
		//XXX if file unaligned (HFS 4k / Fusion 128k) then pin is superset and
		//XXX unmap is subset, so save extra walk over file extents (and the risk
		//XXX that CF drain starts) vs leaving partial units pinned to SSD
		//XXX (until whatever was sharing also unmaps).  Err on cleaning up fully.
		boolean_t will_unmap = (!ref->pinned || ref->cf) && (discard_end > discard_offset);
		boolean_t will_unpin = (ref->pinned && ref->cf /* && !will_unmap */);

		(void) kern_ioctl_file_extents(ref, _DKIOCCSUNPINEXTENT, 0, (will_unpin) ? ref->filelength : 0);

        if (will_unmap)
        {
            (void) kern_ioctl_file_extents(ref, DKIOCUNMAP, discard_offset, (ref->cf) ? ref->filelength : discard_end);
        }

        if (addr && write_length)
        {
            (void) kern_write_file(ref, write_offset, addr, write_length, IO_SKIP_ENCRYPTION);
        }

        error = vnode_close(ref->vp, FWRITE, ref->ctx);

        ref->vp = NULLVP;
        kprintf("vnode_close(%d)\n", error);

    }

    ref->ctx = NULL;

    kfree(ref, sizeof(struct kern_direct_file_io_ref_t));
}