linux mount 文件锁

#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>

int main() {
    int fd = open("example.txt", O_RDWR);
    if (fd == -1) {
        perror("open");
        return 1;
    }

    struct flock fl;
    fl.l_type = F_WRLCK;  // 独占锁
    fl.l_whence = SEEK_SET;
    fl.l_start = 0;
    fl.l_len = 0;

    if (fcntl(fd, F_SETLKW, &fl) == -1) {
        perror("fcntl");
        close(fd);
        return 1;
    }

    // 进行文件操作
    printf("File is locked. Performing operations...\n");

    // 释放锁
    fl.l_type = F_UNLCK;
    if (fcntl(fd, F_SETLK, &fl) == -1) {
        perror("fcntl unlock");
        close(fd);
        return 1;
    }

    close(fd);
    return 0;
}