fix: wipe the first/last 1MiB in addition to wiping by signatures

smira · smira · commit c95c9fd06508 · 2026-01-21T16:25:09.000+04:00
I got a failure when dual-boot image refuses to format EPHEMERAL partition where `EFI` partition used to be (VFAT). So until we have a resolution, do this workaround. Signed-off-by: Andrey Smirnov <andrey.smirnov@siderolabs.com> (cherry picked from commit 3d13016)
diff --git a/internal/pkg/partition/helpers.go b/internal/pkg/partition/helpers.go
@@ -42,10 +42,12 @@ func WipeWithSignatures(bd *block.Device, deviceName string, log func(string, ..
 				),
 			)
 		}
-
-		return nil
 	}
 
+	// [TODO]: wipe the first/last 1MiB after wiping by signatures to cover somewhat unknown edge cases
+	// What has been observed so far is that wiping VFAT signature still makes `mkfs.xfs` believe there is
+	// a VFAT filesystem on the partition, refusing to create XFS over it without `-f` flag.
+	//
 	// probe failed or no signatures found, fast wipe
 	if err = bd.FastWipe(); err != nil {
 		return fmt.Errorf("failed to wipe block device %q: %v", deviceName, err)

Original file line number	Diff line number	Diff line change
`@@ -42,10 +42,12 @@ func WipeWithSignatures(bd *block.Device, deviceName string, log func(string, ..`
`42`	`42`	`),`
`43`	`43`	`)`
`44`	`44`	`}`
`45`		`-`
`46`		`- return nil`
`47`	`45`	`}`
`48`	`46`
	`47`	`+ // [TODO]: wipe the first/last 1MiB after wiping by signatures to cover somewhat unknown edge cases`
	`48`	+ // What has been observed so far is that wiping VFAT signature still makes `mkfs.xfs` believe there is
	`49`	+ // a VFAT filesystem on the partition, refusing to create XFS over it without `-f` flag.
	`50`	`+ //`
`49`	`51`	`// probe failed or no signatures found, fast wipe`
`50`	`52`	`if err = bd.FastWipe(); err != nil {`
`51`	`53`	`return fmt.Errorf("failed to wipe block device %q: %v", deviceName, err)`