Graphdriver/btrfs: Avoid using single d.Get()

Liu Bo · Liu Bo · commit b2e27fee53c2 · 2016-02-04T10:25:24.000-08:00
For btrfs driver, in d.Create(), Get() of parentDir is called but not followed
by Put().

If we apply SElinux mount label, we need to mount btrfs subvolumes in d.Get(),
without a Put() would end up with a later Remove() failure on
"Device resourse is busy".

This calls the subvolume helper function directly in d.Create().

Signed-off-by: Liu Bo &lt;bo.li.liu@oracle.com&gt;
diff --git a/daemon/graphdriver/btrfs/btrfs.go b/daemon/graphdriver/btrfs/btrfs.go
@@ -256,10 +256,14 @@ func (d *Driver) Create(id, parent, mountLabel string) error {
 			return err
 		}
 	} else {
-		parentDir, err := d.Get(parent, "")
+		parentDir := d.subvolumesDirID(parent)
+		st, err := os.Stat(parentDir)
 		if err != nil {
 			return err
 		}
+		if !st.IsDir() {
+			return fmt.Errorf("%s: not a direcotory", parentDir)
+		}
 		if err := subvolSnapshot(parentDir, subvolumes, id); err != nil {
 			return err
 		}

Original file line number	Diff line number	Diff line change
`@@ -256,10 +256,14 @@ func (d *Driver) Create(id, parent, mountLabel string) error {`
`256`	`256`	`return err`
`257`	`257`	`}`
`258`	`258`	`} else {`
`259`		`- parentDir, err := d.Get(parent, "")`
	`259`	`+ parentDir := d.subvolumesDirID(parent)`
	`260`	`+ st, err := os.Stat(parentDir)`
`260`	`261`	`if err != nil {`
`261`	`262`	`return err`
`262`	`263`	`}`
	`264`	`+ if !st.IsDir() {`
	`265`	`+ return fmt.Errorf("%s: not a direcotory", parentDir)`
	`266`	`+ }`
`263`	`267`	`if err := subvolSnapshot(parentDir, subvolumes, id); err != nil {`
`264`	`268`	`return err`
`265`	`269`	`}`