From 72cacd14c67099faf179cce2eda04150289bcbd8 Mon Sep 17 00:00:00 2001
From: Damiano Cipriani <damiano.cipriani@suse.com>
Date: Mon, 16 Dec 2024 13:37:08 +0100
Subject: [PATCH] feat(lvol): add lvol detach parent API

Longhorn 9922

Signed-off-by: Damiano Cipriani <damiano.cipriani@suse.com>
---
 app/cmd/basic/bdev_lvol.go | 42 ++++++++++++++++++++++++++++++++++++++
 pkg/spdk/client/basic.go   | 18 ++++++++++++++++
 pkg/spdk/types/lvol.go     |  4 ++++
 3 files changed, 64 insertions(+)

diff --git a/app/cmd/basic/bdev_lvol.go b/app/cmd/basic/bdev_lvol.go
index 150c149..6e8217c 100644
--- a/app/cmd/basic/bdev_lvol.go
+++ b/app/cmd/basic/bdev_lvol.go
@@ -27,6 +27,7 @@ func BdevLvolCmd() cli.Command {
 			BdevLvolCloneBdevCmd(),
 			BdevLvolSetParentCmd(),
 			BdevLvolDecoupleParentCmd(),
+			BdevLvolDetachParentCmd(),
 			BdevLvolResizeCmd(),
 			BdevLvolStartShallowCopyCmd(),
 			BdevLvolCheckShallowCopyCmd(),
@@ -345,6 +346,47 @@ func bdevLvolDecoupleParent(c *cli.Context) error {
 	return util.PrintObject(decoupled)
 }
 
+func BdevLvolDetachParentCmd() cli.Command {
+	return cli.Command{
+		Name: "detach",
+		Flags: []cli.Flag{
+			cli.StringFlag{
+				Name:  "alias",
+				Usage: "The alias of a lvol is <LVSTORE NAME>/<LVOL NAME>. Specify this or uuid",
+			},
+			cli.StringFlag{
+				Name:  "uuid",
+				Usage: "Specify this or alias",
+			},
+		},
+		Usage: "detach a lvol from its parent lvol: \"detach --alias <LVSTORE NAME>/<LVOL NAME>\", or \"detach --uuid <LVOL UUID>\"",
+		Action: func(c *cli.Context) {
+			if err := bdevLvolDetachParent(c); err != nil {
+				logrus.WithError(err).Fatalf("Failed to run detach parent bdev lvol command")
+			}
+		},
+	}
+}
+
+func bdevLvolDetachParent(c *cli.Context) error {
+	spdkCli, err := client.NewClient(context.Background())
+	if err != nil {
+		return err
+	}
+
+	name := c.String("alias")
+	if name == "" {
+		name = c.String("uuid")
+	}
+
+	decoupled, err := spdkCli.BdevLvolDetachParent(name)
+	if err != nil {
+		return err
+	}
+
+	return util.PrintObject(decoupled)
+}
+
 func BdevLvolSetParentCmd() cli.Command {
 	return cli.Command{
 		Name: "set-parent",
diff --git a/pkg/spdk/client/basic.go b/pkg/spdk/client/basic.go
index bbd5bae..a87198b 100644
--- a/pkg/spdk/client/basic.go
+++ b/pkg/spdk/client/basic.go
@@ -387,6 +387,24 @@ func (c *Client) BdevLvolDecoupleParent(name string) (decoupled bool, err error)
 	return decoupled, json.Unmarshal(cmdOutput, &decoupled)
 }
 
+// BdevLvolDetachParent detach the parent of a logical volume.
+// No new clusters are allocated to the child blob, no data are copied from the parent to the child, so lvol's data are not modified.
+// The parent must be a standard snapshot, not an external snapshot. All dependencies on the parent are removed
+//
+//	"name": Required. UUID or alias of the logical volume to detach the parent of it. The alias of a lvol is <LVSTORE NAME>/<LVOL NAME>.
+func (c *Client) BdevLvolDetachParent(name string) (decoupled bool, err error) {
+	req := spdktypes.BdevLvolDetachParentRequest{
+		Name: name,
+	}
+
+	cmdOutput, err := c.jsonCli.SendCommandWithLongTimeout("bdev_lvol_detach_parent", req)
+	if err != nil {
+		return false, err
+	}
+
+	return decoupled, json.Unmarshal(cmdOutput, &decoupled)
+}
+
 // BdevLvolSetParent sets a snapshot as the parent of a lvol, making the lvol a clone/child of this snapshot.
 // The previous parent of the lvol can be another snapshot or an external snapshot, if the lvol is not a clone must be thin-provisioned.
 // Lvol and parent snapshot must have the same size and must belong to the same lvol store.
diff --git a/pkg/spdk/types/lvol.go b/pkg/spdk/types/lvol.go
index 6f36b4e..246a65b 100644
--- a/pkg/spdk/types/lvol.go
+++ b/pkg/spdk/types/lvol.go
@@ -124,6 +124,10 @@ type BdevLvolDecoupleParentRequest struct {
 	Name string `json:"name"`
 }
 
+type BdevLvolDetachParentRequest struct {
+	Name string `json:"name"`
+}
+
 type BdevLvolSetParentRequest struct {
 	LvolName   string `json:"lvol_name"`
 	ParentName string `json:"parent_name"`