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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2021 Google
* All Rights Reserved.
*
* checkpoint_journal.c
*
* Flush journal log and checkpoint journal for ext4 file system and
* optionally, issue discard or zeroout for the journal log blocks.
*
* Arguments:
* 1) mount point for device
* 2) flags (optional)
* set --erase=discard to enable discarding journal blocks
* set --erase=zeroout to enable zero-filling journal blocks
* set --dry-run flag to only perform input checking
*/
#include <sys/ioctl.h>
#include <fcntl.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <linux/fs.h>
#include <getopt.h>
#if !defined(EXT4_IOC_CHECKPOINT)
#define EXT4_IOC_CHECKPOINT _IOW('f', 43, __u32)
#endif
#if !defined(EXT4_IOC_CHECKPOINT_FLAG_DISCARD)
#define EXT4_IOC_CHECKPOINT_FLAG_DISCARD 1
#define EXT4_IOC_CHECKPOINT_FLAG_ZEROOUT 2
#define EXT4_IOC_CHECKPOINT_FLAG_DRY_RUN 4
#endif
int main(int argc, char** argv) {
int fd, c, ret = 0, option_index = 0;
char* rpath;
unsigned int flags = 0;
static struct option long_options[] =
{
{"dry-run", no_argument, 0, 'd'},
{"erase", required_argument, 0, 'e'},
{0, 0, 0, 0}
};
/* get optional flags */
while ((c = getopt_long(argc, argv, "de:", long_options,
&option_index)) != -1) {
switch (c) {
case 'd':
flags |= EXT4_IOC_CHECKPOINT_FLAG_DRY_RUN;
break;
case 'e':
if (strcmp(optarg, "discard") == 0) {
flags |= EXT4_IOC_CHECKPOINT_FLAG_DISCARD;
} else if (strcmp(optarg, "zeroout") == 0) {
flags |= EXT4_IOC_CHECKPOINT_FLAG_ZEROOUT;
} else {
fprintf(stderr, "Error: invalid erase option\n");
return 1;
}
break;
default:
return 1;
}
}
if (optind != argc - 1) {
fprintf(stderr, "Error: invalid number of arguments\n");
return 1;
}
/* get fd to file system */
rpath = realpath(argv[optind], NULL);
fd = open(rpath, O_RDONLY);
free(rpath);
if (fd == -1) {
fprintf(stderr, "Error: unable to open device %s: %s\n",
argv[optind], strerror(errno));
return 1;
}
ret = ioctl(fd, EXT4_IOC_CHECKPOINT, &flags);
if (ret)
fprintf(stderr, "checkpoint ioctl returned error: %s\n", strerror(errno));
close(fd);
return ret;
}
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