// errTooManyOpenFiles - too many open files.
var errTooManyOpenFiles = StorageErr("too many open files, please increase 'ulimit -n'")

// errFileNameTooLong - given file name is too long than supported length.
var errFileNameTooLong = StorageErr("file name too long")

// errVolumeExists - cannot create same volume again.
var errVolumeExists = StorageErr("volume already exists")

// errIsNotRegular - not of regular file type.

	ErrMissingCustomerKeyMD5 = Errorf("The SSE-C request is missing the customer key MD5")

	// ErrInvalidCustomerKey indicates that the SSE-C client key is not valid - e.g. not a
	// base64-encoded string or not 256 bits long.
	ErrInvalidCustomerKey = Errorf("The SSE-C client key is invalid")

	// ErrSecretKeyMismatch indicates that the provided secret key (SSE-C client key / SSE-S3 KMS key)

    write/flush after response handler has returned.
```

```
λ git cherry-pick 4f3317effea38c203c358af9cb5ce3c0e4173976
```

Requests can be "Single Payload" or "Streamed".

Use the MinIO Grid for:

* Small, frequent requests with low latency requirements.
* Long-running requests with small/medium payloads.

Do *not* use the MinIO Grid for:

* Large payloads.

Only a single connection is ever made between two servers.

	FlagPayloadIsErr

	// FlagPayloadIsZero means that payload is 0-length slice and not nil.
	FlagPayloadIsZero

	// FlagSubroute indicates that the message has subroute.
	// Subroute will be 32 bytes long and added before any CRC.
	FlagSubroute
)

// This struct cannot be changed and retain backwards compatibility.
// If changed, endpoint version must be bumped.
//
//msgp:tuple message
type message struct {

	if err := Mkdir(dirPath, perm); err != nil {
		if osIsExist(err) {
			return nil
		}
		return err
	}

	return nil
}

// The buffer must be at least a block long.
// refer https://github.com/golang/go/issues/24015
const blockSize = 8 << 10 // 8192

// By default at least 128 entries in single getdents call (1MiB buffer)
var (
	direntPool = sync.Pool{

	Service      string
	Region       string
	ResourceType string
	ResourceID   string
}

// Allows english letters, numbers, '.', '-', '_' and '/'. Starts with a
// letter or digit. At least 1 character long.
var validResourceIDRegex = regexp.MustCompile(`[A-Za-z0-9_/\.-]+$`)

// NewIAMRoleARN - returns an ARN for a role in MinIO.
func NewIAMRoleARN(resourceID, serverRegion string) (ARN, error) {

	testCases := []struct {
		objName string
		pass    bool
	}{
		{"/abcdef", true},
		{"/a/b/c/d/e/f/g", true},
		{string(bytes.Repeat([]byte("界"), 85)), true},
		// Each path component must be <= 255 bytes long.
		{string(bytes.Repeat([]byte("界"), 280)), false},
		{`/p/q/r/s/t`, true},
	}
	dir := t.TempDir()

	// Instantiate posix object to manage a disk
	fs, err := newLocalXLStorage(dir)
	if err != nil {

		return key, ErrMissingCustomerKeyMD5
	}

	clientKey, err := base64.StdEncoding.DecodeString(h.Get(xhttp.AmzServerSideEncryptionCopyCustomerKey))
	if err != nil || len(clientKey) != 32 { // The client key must be 256 bits long
		return key, ErrInvalidCustomerKey
	}
	keyMD5, err := base64.StdEncoding.DecodeString(h.Get(xhttp.AmzServerSideEncryptionCopyCustomerKeyMD5))
	if md5Sum := md5.Sum(clientKey); err != nil || !bytes.Equal(md5Sum[:], keyMD5) {

		return key, ErrMissingCustomerKeyMD5
	}

	clientKey, err := base64.StdEncoding.DecodeString(h.Get(xhttp.AmzServerSideEncryptionCustomerKey))
	if err != nil || len(clientKey) != 32 { // The client key must be 256 bits long
		return key, ErrInvalidCustomerKey
	}
	keyMD5, err := base64.StdEncoding.DecodeString(h.Get(xhttp.AmzServerSideEncryptionCustomerKeyMD5))
	if md5Sum := md5.Sum(clientKey); err != nil || !bytes.Equal(md5Sum[:], keyMD5) {