通过loop_info中字段去确认是否mount
/* Backwards compatibility version */
struct loop_info {int lo_number; /* ioctl r/o */__kernel_old_dev_t lo_device; /* ioctl r/o */unsigned long lo_inode; /* ioctl r/o */__kernel_old_dev_t lo_rdevice; /* ioctl r/o */int lo_offset;int lo_encrypt_type;int lo_encrypt_key_size; /* ioctl w/o */int lo_flags; /* ioctl r/o */char lo_name[LO_NAME_SIZE];unsigned char lo_encrypt_key[LO_KEY_SIZE]; /* ioctl w/o */unsigned long lo_init[2];char reserved[4];
};struct loop_info64 {__u64 lo_device; /* ioctl r/o */__u64 lo_inode; /* ioctl r/o */__u64 lo_rdevice; /* ioctl r/o */__u64 lo_offset;__u64 lo_sizelimit;/* bytes, 0 == max available */__u32 lo_number; /* ioctl r/o */__u32 lo_encrypt_type;__u32 lo_encrypt_key_size; /* ioctl w/o */__u32 lo_flags; /* ioctl r/o */__u8 lo_file_name[LO_NAME_SIZE];__u8 lo_crypt_name[LO_NAME_SIZE];__u8 lo_encrypt_key[LO_KEY_SIZE]; /* ioctl w/o */__u64 lo_init[2];
};#include <fcntl.h>
#include <linux/loop.h>
#include <sys/ioctl.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <strings.h>
#define errExit(msg) do { perror(msg); exit(EXIT_FAILURE); \} while (0)int main(int argc, char *argv[])
{int ret = -1;int fd = -1;int i = 0;long devnr;char loopname[4096];char test_name[]="/home/user/test.img";struct loop_info64 test = {0};for(i=0 ; i < 8; i++){sprintf(loopname, "/dev/loop%d", i);fd = open(loopname, O_RDONLY);if(fd == -1){errExit("open: loopname");}ret = ioctl(fd, LOOP_GET_STATUS64, &test);close(fd);if(ret != 0){errExit("ret");}if(strcmp(test.lo_file_name, test_name) == 0){printf("lo_file_name:%s test_name:%s\n", test.lo_file_name, test_name);exit(EXIT_SUCCESS);}}exit(EXIT_SUCCESS);
}