drivers/filesystems/btrfs/calcthread.c

   1 /* Copyright (c) Mark Harmstone 2016-17
   2  *
   3  * This file is part of WinBtrfs.
   4  *
   5  * WinBtrfs is free software: you can redistribute it and/or modify
   6  * it under the terms of the GNU Lesser General Public Licence as published by
   7  * the Free Software Foundation, either version 3 of the Licence, or
   8  * (at your option) any later version.
   9  *
  10  * WinBtrfs is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU Lesser General Public Licence for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General Public Licence
  16  * along with WinBtrfs.  If not, see <http://www.gnu.org/licenses/>. */
  17
  18 #include "btrfs_drv.h"
  19
  20 #define SECTOR_BLOCK 16
  21
  22 NTSTATUS add_calc_job(device_extension* Vcb, UINT8* data, UINT32 sectors, UINT32* csum, calc_job** pcj) {
  23     calc_job* cj;
  24
  25     cj = ExAllocatePoolWithTag(NonPagedPool, sizeof(calc_job), ALLOC_TAG);
  26     if (!cj) {
  27         ERR("out of memory\n");
  28         return STATUS_INSUFFICIENT_RESOURCES;
  29     }
  30
  31     cj->data = data;
  32     cj->sectors = sectors;
  33     cj->csum = csum;
  34     cj->pos = 0;
  35     cj->done = 0;
  36     cj->refcount = 1;
  37     KeInitializeEvent(&cj->event, NotificationEvent, FALSE);
  38
  39     ExAcquireResourceExclusiveLite(&Vcb->calcthreads.lock, TRUE);
  40
  41     InsertTailList(&Vcb->calcthreads.job_list, &cj->list_entry);
  42
  43     KeSetEvent(&Vcb->calcthreads.event, 0, FALSE);
  44     KeClearEvent(&Vcb->calcthreads.event);
  45
  46     ExReleaseResourceLite(&Vcb->calcthreads.lock);
  47
  48     *pcj = cj;
  49
  50     return STATUS_SUCCESS;
  51 }
  52
  53 void free_calc_job(calc_job* cj) {
  54     LONG rc = InterlockedDecrement(&cj->refcount);
  55
  56     if (rc == 0)
  57         ExFreePool(cj);
  58 }
  59
  60 static BOOL do_calc(device_extension* Vcb, calc_job* cj) {
  61     LONG pos, done;
  62     UINT32* csum;
  63     UINT8* data;
  64     ULONG blocksize, i;
  65
  66     pos = InterlockedIncrement(&cj->pos) - 1;
  67
  68     if ((UINT32)pos * SECTOR_BLOCK >= cj->sectors)
  69         return FALSE;
  70
  71     csum = &cj->csum[pos * SECTOR_BLOCK];
  72     data = cj->data + (pos * SECTOR_BLOCK * Vcb->superblock.sector_size);
  73
  74     blocksize = min(SECTOR_BLOCK, cj->sectors - (pos * SECTOR_BLOCK));
  75     for (i = 0; i < blocksize; i++) {
  76         *csum = ~calc_crc32c(0xffffffff, data, Vcb->superblock.sector_size);
  77         csum++;
  78         data += Vcb->superblock.sector_size;
  79     }
  80
  81     done = InterlockedIncrement(&cj->done);
  82
  83     if ((UINT32)done * SECTOR_BLOCK >= cj->sectors) {
  84         ExAcquireResourceExclusiveLite(&Vcb->calcthreads.lock, TRUE);
  85         RemoveEntryList(&cj->list_entry);
  86         ExReleaseResourceLite(&Vcb->calcthreads.lock);
  87
  88         KeSetEvent(&cj->event, 0, FALSE);
  89     }
  90
  91     return TRUE;
  92 }
  93
  94 _Function_class_(KSTART_ROUTINE)
  95 #ifdef __REACTOS__
  96 void NTAPI calc_thread(void* context) {
  97 #else
  98 void calc_thread(void* context) {
  99 #endif
 100     drv_calc_thread* thread = context;
 101     device_extension* Vcb = thread->DeviceObject->DeviceExtension;
 102
 103     ObReferenceObject(thread->DeviceObject);
 104
 105     while (TRUE) {
 106         KeWaitForSingleObject(&Vcb->calcthreads.event, Executive, KernelMode, FALSE, NULL);
 107
 108         while (TRUE) {
 109             calc_job* cj;
 110             BOOL b;
 111
 112             ExAcquireResourceExclusiveLite(&Vcb->calcthreads.lock, TRUE);
 113
 114             if (IsListEmpty(&Vcb->calcthreads.job_list)) {
 115                 ExReleaseResourceLite(&Vcb->calcthreads.lock);
 116                 break;
 117             }
 118
 119             cj = CONTAINING_RECORD(Vcb->calcthreads.job_list.Flink, calc_job, list_entry);
 120             cj->refcount++;
 121
 122             ExReleaseResourceLite(&Vcb->calcthreads.lock);
 123
 124             b = do_calc(Vcb, cj);
 125
 126             free_calc_job(cj);
 127
 128             if (!b)
 129                 break;
 130         }
 131
 132         if (thread->quit)
 133             break;
 134     }
 135
 136     ObDereferenceObject(thread->DeviceObject);
 137
 138     KeSetEvent(&thread->finished, 0, FALSE);
 139
 140     PsTerminateSystemThread(STATUS_SUCCESS);
 141 }