bsd/kern/kern_symfile.c

   1 /*
   2  * Copyright (c) 2000-2006 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 /* Copyright (c) 1998 Apple Computer, Inc.  All rights reserved.
  29  *
  30  *      File:   bsd/kern/kern_symfile.c
  31  *
  32  * HISTORY
  33  */
  34
  35 #include <mach/vm_param.h>
  36
  37 #include <sys/param.h>
  38 #include <sys/systm.h>
  39 #include <sys/signalvar.h>
  40 #include <sys/resourcevar.h>
  41 #include <sys/namei.h>
  42 #include <sys/vnode_internal.h>
  43 #include <sys/proc_internal.h>
  44 #include <sys/kauth.h>
  45 #include <sys/timeb.h>
  46 #include <sys/times.h>
  47 #include <sys/acct.h>
  48 #include <sys/file_internal.h>
  49 #include <sys/uio.h>
  50 #include <sys/kernel.h>
  51 #include <sys/stat.h>
  52 #include <sys/disk.h>
  53 #include <sys/conf.h>
  54 #include <sys/content_protection.h>
  55
  56 #include <mach-o/loader.h>
  57 #include <mach-o/nlist.h>
  58
  59 #include <kern/kalloc.h>
  60 #include <vm/vm_kern.h>
  61 #include <pexpert/pexpert.h>
  62 #include <IOKit/IOPolledInterface.h>
  63
  64 /* This function is called from kern_sysctl in the current process context;
  65  * it is exported with the System6.0.exports, but this appears to be a legacy
  66  * export, as there are no internal consumers.
  67  */
  68 int
  69 get_kernel_symfile(__unused proc_t p, __unused char const **symfile);
  70 int
  71 get_kernel_symfile(__unused proc_t p, __unused char const **symfile)
  72 {
  73     return KERN_FAILURE;
  74 }
  75
  76 struct kern_direct_file_io_ref_t
  77 {
  78     vfs_context_t  ctx;
  79     struct vnode * vp;
  80     dev_t          device;
  81     uint32_t       blksize;
  82     off_t          filelength;
  83     char           cf;
  84     char           pinned;
  85 };
  86
  87
  88 static int file_ioctl(void * p1, void * p2, u_long theIoctl, caddr_t result)
  89 {
  90     dev_t device = *(dev_t*) p1;
  91
  92     return ((*bdevsw[major(device)].d_ioctl)
  93                     (device, theIoctl, result, S_IFBLK, p2));
  94 }
  95
  96 static int device_ioctl(void * p1, __unused void * p2, u_long theIoctl, caddr_t result)
  97 {
  98     return (VNOP_IOCTL(p1, theIoctl, result, 0, p2));
  99 }
 100
 101 static int
 102 kern_ioctl_file_extents(struct kern_direct_file_io_ref_t * ref, u_long theIoctl, off_t offset, off_t end)
 103 {
 104     int error = 0;
 105     int (*do_ioctl)(void * p1, void * p2, u_long theIoctl, caddr_t result);
 106     void * p1;
 107     void * p2;
 108     uint64_t    fileblk;
 109     size_t      filechunk;
 110     dk_extent_t  extent;
 111     dk_unmap_t   unmap;
 112     _dk_cs_pin_t pin;
 113
 114     bzero(&extent, sizeof(dk_extent_t));
 115     bzero(&unmap, sizeof(dk_unmap_t));
 116     bzero(&pin, sizeof(pin));
 117     if (ref->vp->v_type == VREG)
 118     {
 119          p1 = &ref->device;
 120          p2 = kernproc;
 121          do_ioctl = &file_ioctl;
 122     }
 123     else
 124     {
 125         /* Partition. */
 126         p1 = ref->vp;
 127         p2 = ref->ctx;
 128         do_ioctl = &device_ioctl;
 129     }
 130
 131     if (_DKIOCCSPINEXTENT == theIoctl) {
 132             /* Tell CS the image size, so it knows whether to place the subsequent pins SSD/HDD */
 133             pin.cp_extent.length = end;
 134             pin.cp_flags = _DKIOCCSHIBERNATEIMGSIZE;
 135             (void) do_ioctl(p1, p2, _DKIOCCSPINEXTENT, (caddr_t)&pin);
 136     } else if (_DKIOCCSUNPINEXTENT == theIoctl) {
 137             /* Tell CS hibernation is done, so it can stop blocking overlapping writes */
 138             pin.cp_flags = _DKIOCCSPINDISCARDBLACKLIST;
 139             (void) do_ioctl(p1, p2, _DKIOCCSUNPINEXTENT, (caddr_t)&pin);
 140     }
 141
 142     while (offset < end)
 143     {
 144         if (ref->vp->v_type == VREG)
 145         {
 146             daddr64_t blkno;
 147             filechunk = 1*1024*1024*1024;
 148             if (filechunk > (size_t)(end - offset))
 149             filechunk = (size_t)(end - offset);
 150             error = VNOP_BLOCKMAP(ref->vp, offset, filechunk, &blkno,
 151                                                                   &filechunk, NULL, VNODE_WRITE, NULL);
 152                         if (error) break;
 153             fileblk = blkno * ref->blksize;
 154         }
 155         else if ((ref->vp->v_type == VBLK) || (ref->vp->v_type == VCHR))
 156         {
 157             fileblk = offset;
 158             filechunk = ref->filelength;
 159         }
 160
 161         if (DKIOCUNMAP == theIoctl)
 162         {
 163             extent.offset = fileblk;
 164             extent.length = filechunk;
 165             unmap.extents = &extent;
 166             unmap.extentsCount = 1;
 167             error = do_ioctl(p1, p2, theIoctl, (caddr_t)&unmap);
 168 //          printf("DKIOCUNMAP(%d) 0x%qx, 0x%qx\n", error, extent.offset, extent.length);
 169         }
 170         else if (_DKIOCCSPINEXTENT == theIoctl)
 171         {
 172             pin.cp_extent.offset = fileblk;
 173             pin.cp_extent.length = filechunk;
 174             pin.cp_flags = _DKIOCCSPINFORHIBERNATION;
 175             error = do_ioctl(p1, p2, theIoctl, (caddr_t)&pin);
 176             if (error && (ENOTTY != error))
 177             {
 178                 printf("_DKIOCCSPINEXTENT(%d) 0x%qx, 0x%qx\n", error, pin.cp_extent.offset, pin.cp_extent.length);
 179             }
 180         }
 181         else if (_DKIOCCSUNPINEXTENT == theIoctl)
 182         {
 183             pin.cp_extent.offset = fileblk;
 184             pin.cp_extent.length = filechunk;
 185             pin.cp_flags = _DKIOCCSPINFORHIBERNATION;
 186             error = do_ioctl(p1, p2, theIoctl, (caddr_t)&pin);
 187             if (error && (ENOTTY != error))
 188             {
 189                 printf("_DKIOCCSUNPINEXTENT(%d) 0x%qx, 0x%qx\n", error, pin.cp_extent.offset, pin.cp_extent.length);
 190             }
 191         }
 192         else error = EINVAL;
 193
 194         if (error) break;
 195         offset += filechunk;
 196     }
 197     return (error);
 198 }
 199
 200 extern uint32_t freespace_mb(vnode_t vp);
 201
 202 struct kern_direct_file_io_ref_t *
 203 kern_open_file_for_direct_io(const char * name,
 204                              boolean_t create_file,
 205                              kern_get_file_extents_callback_t callback,
 206                              void * callback_ref,
 207                              off_t set_file_size,
 208                              off_t fs_free_size,
 209                              off_t write_file_offset,
 210                              void * write_file_addr,
 211                              size_t write_file_len,
 212                              dev_t * partition_device_result,
 213                              dev_t * image_device_result,
 214                              uint64_t * partitionbase_result,
 215                              uint64_t * maxiocount_result,
 216                              uint32_t * oflags)
 217 {
 218     struct kern_direct_file_io_ref_t * ref;
 219
 220     proc_t            p;
 221     struct vnode_attr va;
 222     int               error;
 223     off_t             f_offset;
 224     uint64_t          fileblk;
 225     size_t            filechunk;
 226     uint64_t          physoffset;
 227     dev_t             device;
 228     dev_t             target = 0;
 229     int               isssd = 0;
 230     uint32_t          flags = 0;
 231     uint32_t          blksize;
 232     off_t             maxiocount, count, segcount;
 233     boolean_t         locked = FALSE;
 234     int               fmode, cmode;
 235     struct            nameidata nd;
 236     u_int32_t         ndflags;
 237     off_t             mpFree;
 238
 239     int (*do_ioctl)(void * p1, void * p2, u_long theIoctl, caddr_t result);
 240     void * p1 = NULL;
 241     void * p2 = NULL;
 242
 243     error = EFAULT;
 244
 245     ref = (struct kern_direct_file_io_ref_t *) kalloc(sizeof(struct kern_direct_file_io_ref_t));
 246     if (!ref)
 247     {
 248         error = EFAULT;
 249         goto out;
 250     }
 251
 252     bzero(ref, sizeof(*ref));
 253     p = kernproc;
 254     ref->ctx = vfs_context_create(vfs_context_kernel());
 255
 256     fmode  = (create_file) ? (O_CREAT | FWRITE) : FWRITE;
 257     cmode =  S_IRUSR | S_IWUSR;
 258     ndflags = NOFOLLOW;
 259     NDINIT(&nd, LOOKUP, OP_OPEN, ndflags, UIO_SYSSPACE, CAST_USER_ADDR_T(name), ref->ctx);
 260     VATTR_INIT(&va);
 261     VATTR_SET(&va, va_mode, cmode);
 262     VATTR_SET(&va, va_dataprotect_flags, VA_DP_RAWENCRYPTED);
 263     VATTR_SET(&va, va_dataprotect_class, PROTECTION_CLASS_D);
 264     if ((error = vn_open_auth(&nd, &fmode, &va))) goto out;
 265
 266     ref->vp = nd.ni_vp;
 267     if (ref->vp->v_type == VREG)
 268     {
 269         vnode_lock_spin(ref->vp);
 270         SET(ref->vp->v_flag, VSWAP);
 271         vnode_unlock(ref->vp);
 272     }
 273
 274     if (write_file_addr && write_file_len)
 275     {
 276         if ((error = kern_write_file(ref, write_file_offset, write_file_addr, write_file_len, 0))) goto out;
 277     }
 278
 279     VATTR_INIT(&va);
 280     VATTR_WANTED(&va, va_rdev);
 281     VATTR_WANTED(&va, va_fsid);
 282     VATTR_WANTED(&va, va_data_size);
 283     VATTR_WANTED(&va, va_data_alloc);
 284     VATTR_WANTED(&va, va_nlink);
 285     error = EFAULT;
 286     if (vnode_getattr(ref->vp, &va, ref->ctx)) goto out;
 287
 288     mpFree = freespace_mb(ref->vp);
 289     mpFree <<= 20;
 290     kprintf("kern_direct_file(%s): vp size %qd, alloc %qd, mp free %qd, keep free %qd\n",
 291                 name, va.va_data_size, va.va_data_alloc, mpFree, fs_free_size);
 292
 293     if (ref->vp->v_type == VREG)
 294     {
 295         /* Don't dump files with links. */
 296         if (va.va_nlink != 1) goto out;
 297
 298         device = va.va_fsid;
 299         ref->filelength = va.va_data_size;
 300
 301         p1 = &device;
 302         p2 = p;
 303         do_ioctl = &file_ioctl;
 304
 305         if (set_file_size)
 306         {
 307             if (fs_free_size)
 308             {
 309                 mpFree += va.va_data_alloc;
 310                 if ((mpFree < set_file_size) || ((mpFree - set_file_size) < fs_free_size))
 311                 {
 312                     error = ENOSPC;
 313                     goto out;
 314                 }
 315             }
 316             error = vnode_setsize(ref->vp, set_file_size, IO_NOZEROFILL | IO_NOAUTH, ref->ctx);
 317             if (error) goto out;
 318             ref->filelength = set_file_size;
 319         }
 320     }
 321     else if ((ref->vp->v_type == VBLK) || (ref->vp->v_type == VCHR))
 322     {
 323         /* Partition. */
 324         device = va.va_rdev;
 325
 326         p1 = ref->vp;
 327         p2 = ref->ctx;
 328         do_ioctl = &device_ioctl;
 329     }
 330     else
 331     {
 332         /* Don't dump to non-regular files. */
 333         error = EFAULT;
 334         goto out;
 335     }
 336     ref->device = device;
 337
 338     // probe for CF
 339     dk_corestorage_info_t cs_info;
 340     memset(&cs_info, 0, sizeof(dk_corestorage_info_t));
 341     error = do_ioctl(p1, p2, DKIOCCORESTORAGE, (caddr_t)&cs_info);
 342     ref->cf = (error == 0) && (cs_info.flags & DK_CORESTORAGE_ENABLE_HOTFILES);
 343
 344     // get block size
 345
 346     error = do_ioctl(p1, p2, DKIOCGETBLOCKSIZE, (caddr_t) &ref->blksize);
 347     if (error)
 348         goto out;
 349
 350     if (ref->vp->v_type != VREG)
 351     {
 352         error = do_ioctl(p1, p2, DKIOCGETBLOCKCOUNT, (caddr_t) &fileblk);
 353         if (error) goto out;
 354         ref->filelength = fileblk * ref->blksize;
 355     }
 356
 357     // pin logical extents
 358
 359     error = kern_ioctl_file_extents(ref, _DKIOCCSPINEXTENT, 0, ref->filelength);
 360     if (error && (ENOTTY != error)) goto out;
 361     ref->pinned = (error == 0);
 362
 363     // generate the block list
 364
 365     error = do_ioctl(p1, p2, DKIOCLOCKPHYSICALEXTENTS, NULL);
 366     if (error) goto out;
 367     locked = TRUE;
 368
 369     f_offset = 0;
 370     while (f_offset < ref->filelength)
 371     {
 372         if (ref->vp->v_type == VREG)
 373         {
 374             filechunk = 1*1024*1024*1024;
 375             daddr64_t blkno;
 376
 377             error = VNOP_BLOCKMAP(ref->vp, f_offset, filechunk, &blkno,
 378                                                                   &filechunk, NULL, VNODE_WRITE, NULL);
 379             if (error) goto out;
 380
 381             fileblk = blkno * ref->blksize;
 382         }
 383         else if ((ref->vp->v_type == VBLK) || (ref->vp->v_type == VCHR))
 384         {
 385             fileblk = f_offset;
 386             filechunk = f_offset ? 0 : ref->filelength;
 387         }
 388
 389         physoffset = 0;
 390         while (physoffset < filechunk)
 391         {
 392             dk_physical_extent_t getphysreq;
 393             bzero(&getphysreq, sizeof(getphysreq));
 394
 395             getphysreq.offset = fileblk + physoffset;
 396             getphysreq.length = (filechunk - physoffset);
 397             error = do_ioctl(p1, p2, DKIOCGETPHYSICALEXTENT, (caddr_t) &getphysreq);
 398             if (error) goto out;
 399             if (!target)
 400             {
 401                 target = getphysreq.dev;
 402             }
 403             else if (target != getphysreq.dev)
 404             {
 405                 error = ENOTSUP;
 406                 goto out;
 407             }
 408 #if HIBFRAGMENT
 409             uint64_t rev;
 410             for (rev = 4096; rev <= getphysreq.length; rev += 4096)
 411             {
 412                 callback(callback_ref, getphysreq.offset + getphysreq.length - rev, 4096);
 413             }
 414 #else
 415             callback(callback_ref, getphysreq.offset, getphysreq.length);
 416 #endif
 417             physoffset += getphysreq.length;
 418         }
 419         f_offset += filechunk;
 420     }
 421     callback(callback_ref, 0ULL, 0ULL);
 422
 423     if (ref->vp->v_type == VREG) p1 = &target;
 424     else
 425     {
 426         p1 = &target;
 427         p2 = p;
 428         do_ioctl = &file_ioctl;
 429     }
 430
 431     // get partition base
 432
 433     if (partitionbase_result)
 434     {
 435         error = do_ioctl(p1, p2, DKIOCGETBASE, (caddr_t) partitionbase_result);
 436         if (error)
 437             goto out;
 438     }
 439
 440     // get block size & constraints
 441
 442     error = do_ioctl(p1, p2, DKIOCGETBLOCKSIZE, (caddr_t) &blksize);
 443     if (error)
 444         goto out;
 445
 446     maxiocount = 1*1024*1024*1024;
 447
 448     error = do_ioctl(p1, p2, DKIOCGETMAXBLOCKCOUNTREAD, (caddr_t) &count);
 449     if (error)
 450         count = 0;
 451     count *= blksize;
 452     if (count && (count < maxiocount))
 453         maxiocount = count;
 454
 455     error = do_ioctl(p1, p2, DKIOCGETMAXBLOCKCOUNTWRITE, (caddr_t) &count);
 456     if (error)
 457         count = 0;
 458     count *= blksize;
 459     if (count && (count < maxiocount))
 460         maxiocount = count;
 461
 462     error = do_ioctl(p1, p2, DKIOCGETMAXBYTECOUNTREAD, (caddr_t) &count);
 463     if (error)
 464         count = 0;
 465     if (count && (count < maxiocount))
 466         maxiocount = count;
 467
 468     error = do_ioctl(p1, p2, DKIOCGETMAXBYTECOUNTWRITE, (caddr_t) &count);
 469     if (error)
 470         count = 0;
 471     if (count && (count < maxiocount))
 472         maxiocount = count;
 473
 474     error = do_ioctl(p1, p2, DKIOCGETMAXSEGMENTBYTECOUNTREAD, (caddr_t) &count);
 475     if (!error)
 476         error = do_ioctl(p1, p2, DKIOCGETMAXSEGMENTCOUNTREAD, (caddr_t) &segcount);
 477     if (error)
 478         count = segcount = 0;
 479     count *= segcount;
 480     if (count && (count < maxiocount))
 481         maxiocount = count;
 482
 483     error = do_ioctl(p1, p2, DKIOCGETMAXSEGMENTBYTECOUNTWRITE, (caddr_t) &count);
 484     if (!error)
 485         error = do_ioctl(p1, p2, DKIOCGETMAXSEGMENTCOUNTWRITE, (caddr_t) &segcount);
 486     if (error)
 487         count = segcount = 0;
 488     count *= segcount;
 489     if (count && (count < maxiocount))
 490         maxiocount = count;
 491
 492     kprintf("max io 0x%qx bytes\n", maxiocount);
 493     if (maxiocount_result)
 494         *maxiocount_result = maxiocount;
 495
 496     error = do_ioctl(p1, p2, DKIOCISSOLIDSTATE, (caddr_t)&isssd);
 497     if (!error && isssd)
 498         flags |= kIOPolledFileSSD;
 499
 500     if (partition_device_result)
 501         *partition_device_result = device;
 502     if (image_device_result)
 503         *image_device_result = target;
 504     if (oflags)
 505         *oflags = flags;
 506
 507     if ((ref->vp->v_type == VBLK) || (ref->vp->v_type == VCHR))
 508     {
 509         vnode_close(ref->vp, FWRITE, ref->ctx);
 510         ref->vp = NULLVP;
 511         vfs_context_rele(ref->ctx);
 512         ref->ctx = NULL;
 513     }
 514
 515 out:
 516     printf("kern_open_file_for_direct_io(%d)\n", error);
 517
 518     if (error && locked)
 519     {
 520         p1 = &device;
 521         (void) do_ioctl(p1, p2, DKIOCUNLOCKPHYSICALEXTENTS, NULL);
 522     }
 523
 524     if (error && ref)
 525     {
 526         if (ref->vp)
 527         {
 528             (void) kern_ioctl_file_extents(ref, _DKIOCCSUNPINEXTENT, 0, (ref->pinned && ref->cf) ? ref->filelength : 0);
 529             vnode_close(ref->vp, FWRITE, ref->ctx);
 530             ref->vp = NULLVP;
 531         }
 532         vfs_context_rele(ref->ctx);
 533         kfree(ref, sizeof(struct kern_direct_file_io_ref_t));
 534         ref = NULL;
 535     }
 536
 537     return(ref);
 538 }
 539
 540 int
 541 kern_write_file(struct kern_direct_file_io_ref_t * ref, off_t offset, void * addr, size_t len, int ioflag)
 542 {
 543     return (vn_rdwr(UIO_WRITE, ref->vp,
 544                         addr, len, offset,
 545                         UIO_SYSSPACE, ioflag|IO_SYNC|IO_NODELOCKED|IO_UNIT,
 546                         vfs_context_ucred(ref->ctx), (int *) 0,
 547                         vfs_context_proc(ref->ctx)));
 548 }
 549
 550 int
 551 kern_read_file(struct kern_direct_file_io_ref_t * ref, off_t offset, void * addr, size_t len, int ioflag)
 552 {
 553     return (vn_rdwr(UIO_READ, ref->vp,
 554                         addr, len, offset,
 555                         UIO_SYSSPACE, ioflag|IO_SYNC|IO_NODELOCKED|IO_UNIT,
 556                         vfs_context_ucred(ref->ctx), (int *) 0,
 557                         vfs_context_proc(ref->ctx)));
 558 }
 559
 560
 561 struct mount *
 562 kern_file_mount(struct kern_direct_file_io_ref_t * ref)
 563 {
 564     return (ref->vp->v_mount);
 565 }
 566
 567 void
 568 kern_close_file_for_direct_io(struct kern_direct_file_io_ref_t * ref,
 569                               off_t write_offset, void * addr, size_t write_length,
 570                               off_t discard_offset, off_t discard_end)
 571 {
 572     int error;
 573     kprintf("kern_close_file_for_direct_io\n");
 574
 575     if (!ref) return;
 576
 577     if (ref->vp)
 578     {
 579         int (*do_ioctl)(void * p1, void * p2, u_long theIoctl, caddr_t result);
 580         void * p1;
 581         void * p2;
 582
 583         if (ref->vp->v_type == VREG)
 584         {
 585             p1 = &ref->device;
 586             p2 = kernproc;
 587             do_ioctl = &file_ioctl;
 588         }
 589         else
 590         {
 591             /* Partition. */
 592             p1 = ref->vp;
 593             p2 = ref->ctx;
 594             do_ioctl = &device_ioctl;
 595         }
 596         (void) do_ioctl(p1, p2, DKIOCUNLOCKPHYSICALEXTENTS, NULL);
 597
 598                 //XXX If unmapping extents then don't also need to unpin; except ...
 599                 //XXX if file unaligned (HFS 4k / Fusion 128k) then pin is superset and
 600                 //XXX unmap is subset, so save extra walk over file extents (and the risk
 601                 //XXX that CF drain starts) vs leaving partial units pinned to SSD
 602                 //XXX (until whatever was sharing also unmaps).  Err on cleaning up fully.
 603                 boolean_t will_unmap = (!ref->pinned || ref->cf) && (discard_end > discard_offset);
 604                 boolean_t will_unpin = (ref->pinned && ref->cf /* && !will_unmap */);
 605
 606                 (void) kern_ioctl_file_extents(ref, _DKIOCCSUNPINEXTENT, 0, (will_unpin) ? ref->filelength : 0);
 607
 608         if (will_unmap)
 609         {
 610             (void) kern_ioctl_file_extents(ref, DKIOCUNMAP, discard_offset, (ref->cf) ? ref->filelength : discard_end);
 611         }
 612
 613         if (addr && write_length)
 614         {
 615             (void) kern_write_file(ref, write_offset, addr, write_length, 0);
 616         }
 617
 618         error = vnode_close(ref->vp, FWRITE, ref->ctx);
 619
 620         ref->vp = NULLVP;
 621         kprintf("vnode_close(%d)\n", error);
 622     }
 623     if (ref->ctx)
 624     {
 625         vfs_context_rele(ref->ctx);
 626         ref->ctx = NULL;
 627     }
 628     kfree(ref, sizeof(struct kern_direct_file_io_ref_t));
 629 }