DMMultipathDevices discovers DM-multipath devices by scanning sys/block/dm-* and filtering on dm/uuid prefix "mpath-". It returns a slice of DMMultipathDevice structs. If no multipath devices are found, it returns an empty (non-nil) slice and no error.
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| 55 | // It returns a slice of DMMultipathDevice structs. If no multipath devices |
| 56 | // are found, it returns an empty (non-nil) slice and no error. |
| 57 | func (fs FS) DMMultipathDevices() ([]DMMultipathDevice, error) { |
| 58 | blockDir := fs.sys.Path(sysBlockPath) |
| 59 | |
| 60 | entries, err := os.ReadDir(blockDir) |
| 61 | if err != nil { |
| 62 | return nil, err |
| 63 | } |
| 64 | |
| 65 | devices := make([]DMMultipathDevice, 0) |
| 66 | for _, entry := range entries { |
| 67 | if !strings.HasPrefix(entry.Name(), "dm-") { |
| 68 | continue |
| 69 | } |
| 70 | |
| 71 | uuid, err := parsers.SysReadFile(fs.sys.Path(sysBlockPath, entry.Name(), sysBlockDM, "uuid")) |
| 72 | if err != nil { |
| 73 | // dm/uuid missing means this is not a device-mapper device; skip it. |
| 74 | if os.IsNotExist(err) { |
| 75 | continue |
| 76 | } |
| 77 | return nil, fmt.Errorf("failed to read dm/uuid for %s: %w", entry.Name(), err) |
| 78 | } |
| 79 | if !strings.HasPrefix(uuid, "mpath-") { |
| 80 | continue |
| 81 | } |
| 82 | |
| 83 | name, err := parsers.SysReadFile(fs.sys.Path(sysBlockPath, entry.Name(), sysBlockDM, "name")) |
| 84 | if err != nil { |
| 85 | return nil, fmt.Errorf("failed to read dm/name for %s: %w", entry.Name(), err) |
| 86 | } |
| 87 | |
| 88 | suspendedVal, err := parsers.ReadUintFromFile(fs.sys.Path(sysBlockPath, entry.Name(), sysBlockDM, "suspended")) |
| 89 | if err != nil { |
| 90 | return nil, fmt.Errorf("failed to read dm/suspended for %s: %w", entry.Name(), err) |
| 91 | } |
| 92 | |
| 93 | sectors, err := parsers.ReadUintFromFile(fs.sys.Path(sysBlockPath, entry.Name(), sysBlockSize)) |
| 94 | if err != nil { |
| 95 | return nil, fmt.Errorf("failed to read size for %s: %w", entry.Name(), err) |
| 96 | } |
| 97 | |
| 98 | paths, err := fs.dmMultipathPaths(entry.Name()) |
| 99 | if err != nil { |
| 100 | return nil, err |
| 101 | } |
| 102 | |
| 103 | devices = append(devices, DMMultipathDevice{ |
| 104 | Name: name, |
| 105 | SysfsName: entry.Name(), |
| 106 | UUID: uuid, |
| 107 | Suspended: suspendedVal == 1, |
| 108 | SizeBytes: sectors * procfs.SectorSize, |
| 109 | Paths: paths, |
| 110 | }) |
| 111 | } |
| 112 | |
| 113 | return devices, nil |
| 114 | } |