feat(path-filter): Filter blockdevice using custom udev rules (#670)

Signed-off-by: Abhishek Agarwal <abhishek.agarwal@mayadata.io>

Author: Abhishek Agarwal

cmd/ndm_daemonset/filter/pathfilter.go

@@ -18,6 +18,8 @@ package filter
 
 import (
 	"github.com/openebs/node-disk-manager/blockdevice"
+	libudevwrapper "github.com/openebs/node-disk-manager/pkg/udev"
+
 	"strings"
 
 	"github.com/openebs/node-disk-manager/cmd/ndm_daemonset/controller"
@@ -100,7 +102,19 @@ func (pf *pathFilter) Include(blockDevice *blockdevice.BlockDevice) bool {
 			return true
 		}
 	}
-	return util.MatchIgnoredCase(pf.includePaths, blockDevice.DevPath)
+	if util.MatchIgnoredCase(pf.includePaths, blockDevice.DevPath) {
+		return true
+	}
+	for _, link := range blockDevice.DevLinks {
+		if link.Kind == libudevwrapper.SYMLINK {
+			for _, symlink := range link.Links {
+				if util.Contains(pf.includePaths, symlink) {
+					return true
+				}
+			}
+		}
+	}
+	return false
 }
 
 // Exclude returns true if the disk path does not match any given
@@ -116,5 +130,17 @@ func (pf *pathFilter) Exclude(blockDevice *blockdevice.BlockDevice) bool {
 			return false
 		}
 	}
-	return !util.MatchIgnoredCase(pf.excludePaths, blockDevice.DevPath)
+	if util.MatchIgnoredCase(pf.excludePaths, blockDevice.DevPath) {
+		return false
+	}
+	for _, link := range blockDevice.DevLinks {
+		if link.Kind == libudevwrapper.SYMLINK {
+			for _, symlink := range link.Links {
+				if util.Contains(pf.excludePaths, symlink) {
+					return false
+				}
+			}
+		}
+	}
+	return true
 }

cmd/ndm_daemonset/probe/udevprobe.go

@@ -325,6 +325,13 @@ func (up *udevProbe) FillBlockDeviceDetails(blockDevice *blockdevice.BlockDevice
 		})
 	}
 
+	if len(udevDiskDetails.SymLinks) != 0 {
+		blockDevice.DevLinks = append(blockDevice.DevLinks, blockdevice.DevLink{
+			Kind:  libudevwrapper.SYMLINK,
+			Links: udevDiskDetails.SymLinks,
+		})
+	}
+
 	// filesystem info of the attached device. Only filesystem data will be filled in the struct,
 	// as the mountpoint related information will be filled in by the mount probe
 	blockDevice.FSInfo.FileSystem = udevDiskDetails.FileSystem

cmd/ndm_daemonset/probe/udevprobe_test.go

@@ -125,6 +125,12 @@ func TestFillDiskDetails(t *testing.T) {
 			Links: mockOsDiskDetails.ByPathDevLinks,
 		})
 	}
+	if len(mockOsDiskDetails.SymLinks) > 0 {
+		expectedDiskInfo.DevLinks = append(expectedDiskInfo.DevLinks, blockdevice.DevLink{
+			Kind:  libudevwrapper.SYMLINK,
+			Links: mockOsDiskDetails.SymLinks,
+		})
+	}
 
 	// The devlinks are compared separately as the ordering of devlinks can be different in some systems
 	// eg: ubuntu 20.04 in github actions

pkg/blkid/blkid.go

@@ -31,8 +31,8 @@ import (
 )
 
 const (
-	fsTypeIdentifier        = "TYPE"
-	labelIdentifier         = "LABEL"
+	fsTypeIdentifier             = "TYPE"
+	labelIdentifier              = "LABEL"
 	partitionTableUUIDIdentifier = "PTUUID"
 	partitionEntryUUIDIdentifier = "PARTUUID"
 )

pkg/udev/common.go

@@ -60,6 +60,8 @@ const (
 	UDEV_DEVLINKS             = "DEVLINKS"             // udev attribute contain devlinks of a disk
 	BY_ID_LINK                = "by-id"                // by-path devlink contains this string
 	BY_PATH_LINK              = "by-path"              // by-path devlink contains this string
+	BY_UUID_LINK              = "by-uuid"              // by-uuid devlink contains the string
+	BY_PARTUUID_LINK          = "by-partuuid"          // by-partuuid devlink contains the string
 	LINK_ID_INDEX             = 4                      // this is used to get link index from dev link
 	UDEV_FS_TYPE              = "ID_FS_TYPE"           // file system type the partition
 	UDEV_FS_UUID              = "ID_FS_UUID"           // UUID of the filesystem present
@@ -71,6 +73,8 @@ const (
 	UDEV_DM_UUID              = "DM_UUID"              // udev attribute to get the device mapper uuid
 	// UDEV_DM_NAME is udev attribute to get the name of the dm device. This is used to generate the device mapper path
 	UDEV_DM_NAME = "DM_NAME"
+	// SYMLINK is used to represent any manually created device symlinks
+	SYMLINK = "symlink"
 )
 
 // UdevDiskDetails struct contain different attribute of disk.
@@ -82,6 +86,7 @@ type UdevDiskDetails struct {
 	Path           string   // Path is Path of a disk.
 	ByIdDevLinks   []string // ByIdDevLinks contains by-id devlinks
 	ByPathDevLinks []string // ByPathDevLinks contains by-path devlinks
+	SymLinks       []string // SymLinks contains device symlinks if any
 	DiskType       string   // DeviceType can be disk, partition
 	// IDType is used for uuid generation using the legacy algorithm
 	IDType     string
@@ -112,6 +117,7 @@ func (device *UdevDevice) DiskInfoFromLibudev() UdevDiskDetails {
 		Path:               device.GetPropertyValue(UDEV_DEVNAME),
 		ByIdDevLinks:       devLinks[BY_ID_LINK],
 		ByPathDevLinks:     devLinks[BY_PATH_LINK],
+		SymLinks:           devLinks[SYMLINK],
 		DiskType:           device.GetDevtype(),
 		IDType:             device.GetPropertyValue(UDEV_TYPE),
 		FileSystem:         device.GetFileSystemInfo(),
@@ -210,6 +216,7 @@ func (device *UdevDevice) GetDevLinks() map[string][]string {
 	devLinkMap := make(map[string][]string)
 	byIdLink := make([]string, 0)
 	byPathLink := make([]string, 0)
+	symLink := make([]string, 0)
 	for _, link := range strings.Split(device.GetPropertyValue(UDEV_DEVLINKS), " ") {
 		/*
 			devlink is like - /dev/disk/by-id/scsi-0Google_PersistentDisk_demo-disk
@@ -228,12 +235,14 @@ func (device *UdevDevice) GetDevLinks() map[string][]string {
 			} else {
 				byIdLink = append(byIdLink, link)
 			}
-		}
-		if util.Contains(parts, BY_PATH_LINK) {
+		} else if util.Contains(parts, BY_PATH_LINK) {
 			byPathLink = append(byPathLink, link)
 		}
+		// we can add very dev link in symlink map as there is a 1:1 mapping between the two links
+		symLink = append(symLink, link)
 	}
 	devLinkMap[BY_ID_LINK] = byIdLink
 	devLinkMap[BY_PATH_LINK] = byPathLink
+	devLinkMap[SYMLINK] = symLink
 	return devLinkMap
 }

pkg/udev/common_test.go

@@ -85,6 +85,7 @@ func TestDiskInfoFromLibudev(t *testing.T) {
 		Path:               diskDetails.DevNode,
 		ByIdDevLinks:       diskDetails.ByIdDevLinks,
 		ByPathDevLinks:     diskDetails.ByPathDevLinks,
+		SymLinks:           diskDetails.SymLinks,
 		PartitionTableType: diskDetails.PartTableType,
 		IDType:             diskDetails.IdType,
 	}
@@ -101,8 +102,10 @@ func TestDiskInfoFromLibudev(t *testing.T) {
 			// need to make this nil as devlinks already compared.
 			test.expectedDetails.ByIdDevLinks = nil
 			test.expectedDetails.ByPathDevLinks = nil
+			test.expectedDetails.SymLinks = nil
 			test.actualDetails.ByIdDevLinks = nil
 			test.actualDetails.ByPathDevLinks = nil
+			test.actualDetails.SymLinks = nil
 			assert.Equal(t, test.expectedDetails, test.actualDetails)
 		})
 	}

pkg/udev/mockdata.go

@@ -55,6 +55,7 @@ type MockOsDiskDetails struct {
 	IdType         string
 	ByIdDevLinks   []string
 	ByPathDevLinks []string
+	SymLinks       []string
 	Dependents     bd.DependentBlockDevices
 }
 
@@ -108,6 +109,7 @@ func MockDiskDetails() (MockOsDiskDetails, error) {
 	devLinks := device.GetDevLinks()
 	diskDetails.ByIdDevLinks = devLinks[BY_ID_LINK]
 	diskDetails.ByPathDevLinks = devLinks[BY_PATH_LINK]
+	diskDetails.SymLinks = devLinks[SYMLINK]
 	return diskDetails, nil
 }