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/*
* Copyright (C) 2011 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "ext4_utils/wipe.h"
#include "ext4_utils/ext4_utils.h"
#include <android-base/file.h>
#if WIPE_IS_SUPPORTED
#if defined(__linux__)
#include <linux/fs.h>
#include <sys/ioctl.h>
#include "helpers.h"
#ifndef BLKDISCARD
#define BLKDISCARD _IO(0x12, 119)
#endif
#ifndef BLKSECDISCARD
#define BLKSECDISCARD _IO(0x12, 125)
#endif
int wipe_block_device(int fd, s64 len) {
u64 range[2];
int ret;
if (!is_block_device_fd(fd)) {
// Wiping only makes sense on a block device.
return 0;
}
range[0] = 0;
range[1] = len;
ret = ioctl(fd, BLKSECDISCARD, &range);
if (ret < 0) {
range[0] = 0;
range[1] = len;
ret = ioctl(fd, BLKDISCARD, &range);
if (ret < 0) {
warn("Discard failed\n");
return 1;
} else {
char buf[4096] = {0};
if (!android::base::WriteFully(fd, buf, 4096)) {
warn("Writing zeros failed\n");
return 1;
}
fsync(fd);
warn("Wipe via secure discard failed, used discard instead\n");
return 0;
}
}
return 0;
}
#else /* __linux__ */
#error "Missing block device wiping implementation for this platform!"
#endif
#else /* WIPE_IS_SUPPORTED */
int wipe_block_device(int fd __attribute__((unused)), s64 len __attribute__((unused))) {
/* Wiping is not supported on this platform. */
return 1;
}
#endif /* WIPE_IS_SUPPORTED */
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