```
commit 886262e58af77ebc7c836ef587c08544e9a0c271
Author: Harshavardhana <******@****.***>
Date:   Wed Nov 17 15:49:12 2021 -0800

    heal legacy objects when versioning is enabled after upgrade (#13671)
```

// specified by the developer. The purpose is to simulate errors
// that are hard to simulate in practice like DiskNotFound.
// Programmed errors are stored in errors field.
type naughtyDisk struct {
	// The real disk
	disk StorageAPI
	// Programmed errors: API call number => error to return
	errors map[int]error
	// The error to return when no error value is programmed
	defaultErr error
	// The current API call number

	Sleep        = "max_sleep"
	IOCount      = "max_io"
	DriveWorkers = "drive_workers"

	EnvBitrot       = "MINIO_HEAL_BITROTSCAN"
	EnvSleep        = "MINIO_HEAL_MAX_SLEEP"
	EnvIOCount      = "MINIO_HEAL_MAX_IO"
	EnvDriveWorkers = "MINIO_HEAL_DRIVE_WORKERS"
)

var configMutex sync.RWMutex

// Config represents the heal settings.
type Config struct {
	// Bitrot will perform bitrot scan on local disk when checking objects.

	xForwardedProto  = http.CanonicalHeaderKey("X-Forwarded-Proto")
	xForwardedScheme = http.CanonicalHeaderKey("X-Forwarded-Scheme")
	xRealIP          = http.CanonicalHeaderKey("X-Real-IP")
)

var (
	// RFC7239 defines a new "Forwarded: " header designed to replace the
	// existing use of X-Forwarded-* headers.
	// e.g. Forwarded: for=192.0.2.60;proto=https;by=203.0.113.43

	"github.com/minio/sio"
)

const (
	// SealAlgorithm is the encryption/sealing algorithm used to derive & seal
	// the key-encryption-key and to en/decrypt the object data.
	SealAlgorithm = "DAREv2-HMAC-SHA256"

	// InsecureSealAlgorithm is the legacy encryption/sealing algorithm used
	// to derive & seal the key-encryption-key and to en/decrypt the object data.

whereas in MinIO erasure code you can lose as many as half of drives and still the data remains safe. Further, MinIO's erasure code is at the object level and can heal one object at a time. For RAID, healing can be done only at the volume level which translates into high downtime. As MinIO encodes each object individually, it can heal objects incrementally. Storage servers once deployed should not require drive replacement or healing for the lifetime of the server. MinIO's erasure coded backend is...

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## Context
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## Regression
<!-- Is this issue a regression? (Yes / No) -->
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// formatMetaV1 should be inherited by backend format structs. Please look at format-fs.go
// and format-xl.go for details.

// Ideally we will never have a situation where we will have to change the
// fields of this struct and deal with related migration.
type formatMetaV1 struct {
	// Version of the format config.
	Version string `json:"version"`
	// Format indicates the backend format type, supports two values 'xl' and 'fs'.

type lcEventSrc uint8

//revive:disable:var-naming Underscores is used here to indicate where common prefix ends and the enumeration name begins
const (
	lcEventSrc_None lcEventSrc = iota
	lcEventSrc_Heal
	lcEventSrc_Scanner
	lcEventSrc_Decom
	lcEventSrc_Rebal
	lcEventSrc_s3HeadObject
	lcEventSrc_s3GetObject
	lcEventSrc_s3ListObjects
	lcEventSrc_s3PutObject
	lcEventSrc_s3CopyObject

	dataUsageBloomName     = ".bloomcycle.bin"
	dataUsageBloomNamePath = bucketMetaPrefix + SlashSeparator + dataUsageBloomName

	backgroundHealInfoPath = bucketMetaPrefix + SlashSeparator + ".background-heal.json"

	dataUsageCacheName = ".usage-cache.bin"
)

// storeDataUsageInBackend will store all objects sent on the dui channel until closed.