Set disk to nil after write which needs quorum (#3795)

Ignore a disk which wasn't able to successfully perform an action to
avoid eventual perturbations when the disk comes back in the middle
of write change.

cmd/erasure-createfile.go

@@ -114,6 +114,7 @@ func appendFile(disks []StorageAPI, volume, path string, enBlocks [][]byte, hash
 	// Write encoded data to quorum disks in parallel.
 	for index, disk := range disks {
 		if disk == nil {
+			wErrs[index] = traceError(errDiskNotFound)
 			continue
 		}
 		wg.Add(1)
@@ -123,6 +124,8 @@ func appendFile(disks []StorageAPI, volume, path string, enBlocks [][]byte, hash
 			wErr := disk.AppendFile(volume, path, enBlocks[index])
 			if wErr != nil {
 				wErrs[index] = traceError(wErr)
+				// Ignore disk which returned an error.
+				disks[index] = nil
 				return
 			}
 

cmd/xl-v1-metadata.go

@@ -361,6 +361,8 @@ func writeUniqueXLMetadata(disks []StorageAPI, bucket, prefix string, xlMetas []
 			err := writeXLMetadata(disk, bucket, prefix, xlMetas[index])
 			if err != nil {
 				mErrs[index] = err
+				// Ignore disk which returned an error.
+				disks[index] = nil
 			}
 		}(index, disk)
 	}
@@ -399,6 +401,8 @@ func writeSameXLMetadata(disks []StorageAPI, bucket, prefix string, xlMeta xlMet
 			err := writeXLMetadata(disk, bucket, prefix, metadata)
 			if err != nil {
 				mErrs[index] = err
+				// Ignore disk which returned an error.
+				disks[index] = nil
 			}
 		}(index, disk, xlMeta)
 	}

cmd/xl-v1-multipart.go

@@ -254,6 +254,8 @@ func commitXLMetadata(disks []StorageAPI, srcBucket, srcPrefix, dstBucket, dstPr
 			rErr := disk.RenameFile(srcBucket, srcJSONFile, dstBucket, dstJSONFile)
 			if rErr != nil {
 				mErrs[index] = traceError(rErr)
+				// Ignore disk which returned an error.
+				disks[index] = nil
 				return
 			}
 			mErrs[index] = nil

cmd/xl-v1-object.go

@@ -395,6 +395,8 @@ func rename(disks []StorageAPI, srcBucket, srcEntry, dstBucket, dstEntry string,
 			err := disk.RenameFile(srcBucket, srcEntry, dstBucket, dstEntry)
 			if err != nil && err != errFileNotFound {
 				errs[index] = traceError(err)
+				// Ignore disk which returned an error.
+				disks[index] = nil
 			}
 		}(index, disk)
 	}