wipe.c

   1 /*
   2  * Copyright (C) 2011 The Android Open Source Project
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *      http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 #include "ext4_utils.h"
  18 #include "wipe.h"
  19
  20 #if WIPE_IS_SUPPORTED
  21
  22 #if defined(__linux__)
  23
  24 #include <linux/fs.h>
  25 #include <sys/ioctl.h>
  26
  27 #ifndef BLKDISCARD
  28 #define BLKDISCARD _IO(0x12,119)
  29 #endif
  30
  31 #ifndef BLKSECDISCARD
  32 #define BLKSECDISCARD _IO(0x12,125)
  33 #endif
  34
  35 int wipe_block_device(int fd, s64 len)
  36 {
  37         u64 range[2];
  38         int ret;
  39
  40         if (!is_block_device_fd(fd)) {
  41                 // Wiping only makes sense on a block device.
  42                 return 0;
  43         }
  44
  45         range[0] = 0;
  46         range[1] = len;
  47         ret = ioctl(fd, BLKSECDISCARD, &range);
  48         if (ret < 0) {
  49                 range[0] = 0;
  50                 range[1] = len;
  51                 ret = ioctl(fd, BLKDISCARD, &range);
  52                 if (ret < 0) {
  53                         warn("Discard failed\n");
  54                         return 1;
  55                 } else {
  56                         warn("Wipe via secure discard failed, used discard instead\n");
  57                         return 0;
  58                 }
  59         }
  60
  61         return 0;
  62 }
  63
  64 #else  /* __linux__ */
  65 #error "Missing block device wiping implementation for this platform!"
  66 #endif
  67
  68 #else  /* WIPE_IS_SUPPORTED */
  69
  70 int wipe_block_device(int fd, s64 len)
  71 {
  72         /* Wiping is not supported on this platform. */
  73         return 1;
  74 }
  75
  76 #endif  /* WIPE_IS_SUPPORTED */