github.com/openebs/node-disk-manager@v1.9.1-0.20230225014141-4531f06ffa1e/pkg/spdk/spdk.go (about)

     1  /*
     2  Copyright 2020 The OpenEBS Authors
     3  
     4  Licensed under the Apache License, Version 2.0 (the "License");
     5  you may not use this file except in compliance with the License.
     6  You may obtain a copy of the License at
     7  
     8      http://www.apache.org/licenses/LICENSE-2.0
     9  
    10  Unless required by applicable law or agreed to in writing, software
    11  distributed under the License is distributed on an "AS IS" BASIS,
    12  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13  See the License for the specific language governing permissions and
    14  limitations under the License.
    15  */
    16  
    17  // +build linux, cgo
    18  
    19  package spdk
    20  
    21  /*
    22  #include "stdlib.h"
    23  #include "stdint.h"
    24  
    25  #define SPDK_BLOBSTORE_TYPE_LENGTH 16
    26  
    27  typedef uint64_t spdk_blob_id;
    28  
    29  typedef struct {
    30          char bstype[SPDK_BLOBSTORE_TYPE_LENGTH];
    31  }spdk_bs_type;
    32  
    33  struct spdk_bs_super_block {
    34          uint8_t         signature[8];
    35          uint32_t        version;
    36          uint32_t        length;
    37          uint32_t        clean;
    38  		spdk_blob_id    super_blob;
    39  		uint32_t        cluster_size;
    40  		uint32_t        used_page_mask_start;
    41  		uint32_t        used_page_mask_len;
    42  		uint32_t        used_cluster_mask_start;
    43  		uint32_t        used_cluster_mask_len;
    44  		uint32_t        md_start;
    45  		uint32_t        md_len;
    46  		spdk_bs_type     bstype;
    47  		uint32_t        used_blobid_mask_start;
    48  		uint32_t        used_blobid_mask_len;
    49  		uint64_t        size;
    50  		uint32_t        io_unit_size;
    51  		uint8_t         reserved[4000];
    52  		uint32_t        crc;
    53  };
    54  
    55  char *get_signature(struct spdk_bs_super_block *spdk)
    56  {
    57  	return spdk->signature;
    58  }
    59  */
    60  import "C"
    61  import (
    62  	"encoding/binary"
    63  	"fmt"
    64  	"io"
    65  	"os"
    66  	"unsafe"
    67  )
    68  
    69  const spdkSignature = "SPDKBLOB"
    70  
    71  type DeviceIdentifier struct {
    72  	DevPath string
    73  }
    74  
    75  // IsSPDKSignatureExist check is the signature matches the spdk super block signature
    76  func IsSPDKSignatureExist(signature string) bool {
    77  	// need to compare only the first 8 characters of signature
    78  	if len(signature) > 8 {
    79  		signature = signature[0:8]
    80  	}
    81  	return signature == spdkSignature
    82  }
    83  
    84  // GetSPDKSuperBlockSignature tries to read spdk super block from a disk and returns the signature
    85  func (di *DeviceIdentifier) GetSPDKSuperBlockSignature() (string, error) {
    86  	var spdk *C.struct_spdk_bs_super_block
    87  	buf := make([]byte, C.sizeof_struct_spdk_bs_super_block)
    88  	f, err := os.Open(di.DevPath)
    89  	defer f.Close()
    90  	if err != nil {
    91  		return "", err
    92  	}
    93  	_, err = f.Seek(0, io.SeekStart)
    94  	if err != nil {
    95  		return "", err
    96  	}
    97  	err = binary.Read(f, binary.BigEndian, buf)
    98  	if err != nil {
    99  		return "", fmt.Errorf("error reading from %s: %v", di.DevPath, err)
   100  	}
   101  
   102  	// converting the read bytes to spdk super block struct
   103  	spdk = (*C.struct_spdk_bs_super_block)(C.CBytes(buf))
   104  	defer C.free(unsafe.Pointer(spdk))
   105  
   106  	ptr := (*C.char)(C.get_signature(spdk))
   107  	return C.GoString(ptr), nil
   108  }