minio/cmd/xl-v1-common.go
Harshavardhana ad86454580 Make sure to handle FaultyDisks in listing ops (#6204)
Continuing from PR 157ed65c35

Our posix.go implementation did not handle  I/O errors
properly on the disks, this led to situations where
top-level callers such as ListObjects might return early
without even verifying all the available disks.

This commit tries to address this in Kubernetes, drbd/nbd based
persistent volumes which can disconnect under load and
result in the situations with disks return I/O errors.

This commit also simplifies listing operation, listing
never returns any error. We can avoid this since we pretty
much ignore most of the errors anyways. When objects are
accessed directly we return proper errors.
2018-07-27 15:32:19 -07:00

119 lines
3.8 KiB
Go

/*
* Minio Cloud Storage, (C) 2016, 2017 Minio, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package cmd
import (
"context"
"path"
"github.com/minio/minio/cmd/logger"
)
// getLoadBalancedDisks - fetches load balanced (sufficiently randomized) disk slice.
func (xl xlObjects) getLoadBalancedDisks() (disks []StorageAPI) {
// Based on the random shuffling return back randomized disks.
for _, i := range hashOrder(UTCNow().String(), len(xl.getDisks())) {
disks = append(disks, xl.getDisks()[i-1])
}
return disks
}
// This function does the following check, suppose
// object is "a/b/c/d", stat makes sure that objects ""a/b/c""
// "a/b" and "a" do not exist.
func (xl xlObjects) parentDirIsObject(ctx context.Context, bucket, parent string) bool {
var isParentDirObject func(string) bool
isParentDirObject = func(p string) bool {
if p == "." || p == "/" {
return false
}
if xl.isObject(bucket, p) {
// If there is already a file at prefix "p", return true.
return true
}
// Check if there is a file as one of the parent paths.
return isParentDirObject(path.Dir(p))
}
return isParentDirObject(parent)
}
var xlTreeWalkIgnoredErrs = append(baseIgnoredErrs, errDiskAccessDenied, errVolumeNotFound, errFileNotFound)
// isObject - returns `true` if the prefix is an object i.e if
// `xl.json` exists at the leaf, false otherwise.
func (xl xlObjects) isObject(bucket, prefix string) (ok bool) {
for _, disk := range xl.getLoadBalancedDisks() {
if disk == nil {
continue
}
// Check if 'prefix' is an object on this 'disk', else continue the check the next disk
_, err := disk.StatFile(bucket, path.Join(prefix, xlMetaJSONFile))
if err == nil {
return true
}
// Ignore for file not found, disk not found or faulty disk.
if IsErrIgnored(err, xlTreeWalkIgnoredErrs...) {
continue
}
reqInfo := &logger.ReqInfo{BucketName: bucket}
reqInfo.AppendTags("prefix", prefix)
reqInfo.AppendTags("xlMetaJSONFile", xlMetaJSONFile)
ctx := logger.SetReqInfo(context.Background(), reqInfo)
logger.LogIf(ctx, err)
} // Exhausted all disks - return false.
return false
}
// isObjectDir returns if the specified path represents an empty directory.
func (xl xlObjects) isObjectDir(bucket, prefix string) (ok bool) {
for _, disk := range xl.getLoadBalancedDisks() {
if disk == nil {
continue
}
// Check if 'prefix' is an object on this 'disk', else continue the check the next disk
ctnts, err := disk.ListDir(bucket, prefix, 1)
if err == nil {
if len(ctnts) == 0 {
return true
}
return false
}
// Ignore for file not found, disk not found or faulty disk.
if IsErrIgnored(err, xlTreeWalkIgnoredErrs...) {
continue
}
reqInfo := &logger.ReqInfo{BucketName: bucket}
reqInfo.AppendTags("prefix", prefix)
ctx := logger.SetReqInfo(context.Background(), reqInfo)
logger.LogIf(ctx, err)
} // Exhausted all disks - return false.
return false
}
// Calculate the space occupied by an object in a single disk
func (xl xlObjects) sizeOnDisk(fileSize int64, blockSize int64, dataBlocks int) int64 {
numBlocks := fileSize / blockSize
chunkSize := ceilFrac(blockSize, int64(dataBlocks))
sizeInDisk := numBlocks * chunkSize
remaining := fileSize % blockSize
if remaining > 0 {
sizeInDisk += ceilFrac(remaining, int64(dataBlocks))
}
return sizeInDisk
}