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#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <xfs/xfs.h>
#include <sys/mman.h>
/*
* mmap a preallocated file and write to a set of offsets
* in it. We'll check to see if the underlying extents are
* converted correctly on writeback.
*/
int main(int argc, char **argv) {
unsigned long long o;
int fd, i;
struct xfs_flock64 space;
unsigned char *buf;
if(argc < 3) {
fprintf(stderr, "%s <count> <file [file...]>\n", argv[0]);
exit(1);
}
errno = 0;
o = strtoull(argv[1], NULL, 0);
if (errno) {
perror("strtoull");
exit(errno);
}
for(i = 2; i < argc; i++) {
unlink(argv[i]);
fd = open(argv[i], O_RDWR|O_CREAT|O_LARGEFILE, 0666);
if(fd < 0) {
perror("open");
exit(2);
}
if(ftruncate64(fd, o) < 0) {
perror("ftruncate64");
exit(3);
}
space.l_whence = SEEK_SET;
space.l_start = 0;
space.l_len = o;
if(ioctl(fd, XFS_IOC_RESVSP64, &space)) {
perror("ioctl()");
exit(4);
}
buf = mmap(NULL, (int)o, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
if(buf == MAP_FAILED) {
perror("mmap()");
exit(5);
} else {
buf[o-1] = 0;
buf[o/2] = 0;
buf[0] = 0;
munmap(buf, o);
}
fsync(fd);
if(close(fd) == -1) {
perror("close");
exit(6);
}
}
exit(0);
}
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