theoretically a way to interact with the asmlib ABI. written with a lot of help from this awesome article: http://www.scaleabilities.co.uk/2013/02/07/diagnosing-asmlib/ i'm uploading this as a gist because it is a proof of concept and not syntactically correct. i need a testing environment, which i don't have right now. usage: ./asm_release ASMX…

gistfile1.c

//
// asm_release.c
//
// Releases disks from ASM after removing them from a disk group by utilizing the
// oracleasm ABI.
//
// Usage: ./asm_release ASMXXXXXX 
// - where ASMXXXXXX is the ASM disk name.
//
// Constructed with help from the following article:
// http://www.scaleabilities.co.uk/2013/02/07/diagnosing-asmlib/
//

#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>

struct oracleasm_abi_info
{
/*00*/  __u32       ai_magic;   /* ASM_ABI_MAGIC */
        __u16       ai_version; /* ABI version */
        __u16       ai_type;    /* Type of operation */
        __u32       ai_size;    /* Size of passed struct */
        __u32       ai_status;  /* Did it succeed */
/*10*/        
};

struct oracleasm_close_disk_v2
{
/*00*/  struct oracleasm_abi_info   cd_abi;
/*10*/  __u64                       cd_handle;
/*18*/    
};

int main(int argc, char * argv[]) {

    if (argc < 2) {
        fprintf(stderr, "Usage: %s [asm device name].\n\n e.g. %s ASMXXXXXX\n",
                argv[0], 
                argv[0]);
        return 1;
    }

    int res, fd;
    const char * path = "/dev/oracleasm/disks/" + argv[1];
    struct stat *buf = malloc(sizeof(struct stat));
    
    // Fetch the inode number for the device that we want to free.  This is the
    // handle that we end up passing to the oracleasm ABI.
    res = stat(path, buf);
    if (res == -1) {
        fprintf(stderr, "Error opening file: %s", strerror(errno));
        return 1;
    }
    ino_t inode = buf.st_ino;
    free(buf);

    struct oracleasm_abi_info oabi =  {
                                        .ai_magic   = strtoul("MSA\0"),
                                        .ai_version = "\2\0",
                                        .ai_type    = "\06\0", // ASMOP_CLOSE_DISK
                                        .ai_size    = 18, // sizeof(oracleasm_close_disk_v2)
                                        .ai_status  = 0
                                      };

    struct oracleasm_close_disk_v2 cdv2 = {
                                            .cd_abi = oabi,
                                            .cd_handle = (__u64)inode
                                          };

    // this needs to be replaced with code that determines the correct IID
    fd = open("/dev/oracleasm/iid/0000000000000009")
    if (fd == -1) {
        fprintf(stderr, "Error opening file: %s", strerror(errno));
        return 1;
    }

    // This is the way that asmlib accepts operations from user space.
    res = read(fd, (void *)cdv2, 80);
    return res;
}