Create tons of dentry cache entries

fopen.c

#include <stdio.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <errno.h>

int main(int argc, char **argv) {
        char *prefix;
        char *open_mode;
        char filename[1024];
        int i = 0;
        FILE *fd = NULL;

        if (argc < 3) {
                fprintf(stderr, "2 params expected: fopen <temp dir name> <file open mode>\n");
                return 1;
        }
        prefix = argv[1];
        open_mode = argv[2];

        sprintf(filename, "/tmp/%s", prefix);
        if (mkdir(filename, 0777)) {
                if (errno != EEXIST) {
                        fprintf(stderr, "Unable to create %s\n", filename);
                        return 2;
                }
        }
        while (1) {
                sprintf(filename, "/tmp/%s/%d", prefix, i);
                fd = fopen(filename, open_mode);
                if (fd != NULL) fclose(fd);
                ++i;
        }

        return 0;
}