{
int fd;
char *buf;
- int blocks;
+ int blocks, seek_blocks;
long len;
- struct stat st;
+ off64_t seek;
+ struct stat64 st;
int rc;
- if (argc != 3) {
- printf("Usage: %s file nr_blocks\n", argv[0]);
+ if (argc != 4) {
+ printf("Usage: %s file seek nr_blocks\n", argv[0]);
return 1;
}
- blocks = strtoul(argv[2], 0, 0);
- fd = open(argv[1], O_DIRECT | O_RDWR | O_CREAT, 0644);
+ seek_blocks = strtoul(argv[2], 0, 0);
+ blocks = strtoul(argv[3], 0, 0);
+ fd = open(argv[1], O_LARGEFILE | O_DIRECT | O_RDWR | O_CREAT, 0644);
if (fd == -1) {
printf("Cannot open %s: %s\n", argv[1], strerror(errno));
return 1;
}
- if (fstat(fd, &st) < 0) {
+ if (fstat64(fd, &st) < 0) {
printf("Cannot stat %s: %s\n", argv[1], strerror(errno));
return 1;
}
printf("directio on %s for %dx%lu blocks \n", argv[1], blocks,
st.st_blksize);
+ seek = (off64_t)seek_blocks * (off64_t)st.st_blksize;
+ if (lseek64(fd, seek, SEEK_SET) < 0) {
+ printf("lseek64 failed: %s\n", strerror(errno));
+ return 1;
+ }
+
len = blocks * st.st_blksize;
buf = mmap(0, len, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANON, 0, 0);
if (!buf) {
return 1;
}
- if (lseek(fd, 0, SEEK_SET) != 0) {
+ if (lseek64(fd, seek, SEEK_SET) < 0) {
printf("Cannot seek %s\n", strerror(errno));
return 1;
}