88 lines
1.9 KiB
C
88 lines
1.9 KiB
C
#include <stdio.h>
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#include <stdlib.h>
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#include <fcntl.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <sys/ioctl.h>
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#include <linux/fs.h>
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/* get_block - for the file associated with the given fd, returns
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* the physical block mapping to logical_block
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*/
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int get_block(int fd, int logical_block);
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/* get_nr_blocks - returns the number of logical blocks
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* consumed by the file associated with fd
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*/
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int get_nr_blocks(int fd);
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/* print_blocks - for each logical block consumed by the file
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* associated with fd, prints to standard out the tuple
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* "(logical block, physical block)"
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*/
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void print_blocks(int fd);
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int main(int argc, char *argv[]) {
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if (argc < 2) {
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fprintf(stderr, "usage: %s <file>\n", argv[0]);
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return 1;
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}
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int fd = open(argv[1], O_RDONLY);
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if (fd < 0) {
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perror("open");
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return 1;
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}
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print_blocks(fd);
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return 0;
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}
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int get_block(int fd, int logical_block) {
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int ret = ioctl(fd, FIBMAP, &logical_block);
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if (ret < 0) {
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perror("ioctl");
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return -1;
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}
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return logical_block;
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}
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int get_nr_blocks(int fd) {
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struct stat buf;
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int ret = fstat(fd, &buf);
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if (ret < 0) {
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perror("fstat");
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return -1;
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}
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return buf.st_blocks;
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}
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void print_blocks(int fd) {
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int nr_blocks = get_nr_blocks(fd);
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if (nr_blocks < 0) {
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fprintf(stderr, "get_nr_blocks failed!\n");
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return;
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}
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if (nr_blocks == 0) {
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printf("no allocated blocks\n");
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return;
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} else if (nr_blocks == 1) {
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printf("1 block\n");
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} else {
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printf("%d blocks\n\n", nr_blocks);
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}
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for (int i = 0; i < nr_blocks; i++) {
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int phys_block = get_block(fd, i);
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if (phys_block < 0) {
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fprintf(stderr, "get_block failed!\n");
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return;
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}
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if (!phys_block) continue;
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printf("(%u, %u) ", i, phys_block);
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}
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putchar('\n');
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}
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