storj.io/minio@v0.0.0-20230509071714-0cbc90f649b1/cmd/fallocate_linux.go (about)

     1  //go:build linux
     2  // +build linux
     3  
     4  /*
     5   * MinIO Cloud Storage, (C) 2016 MinIO, Inc.
     6   *
     7   * Licensed under the Apache License, Version 2.0 (the "License");
     8   * you may not use this file except in compliance with the License.
     9   * You may obtain a copy of the License at
    10   *
    11   *     http://www.apache.org/licenses/LICENSE-2.0
    12   *
    13   * Unless required by applicable law or agreed to in writing, software
    14   * distributed under the License is distributed on an "AS IS" BASIS,
    15   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    16   * See the License for the specific language governing permissions and
    17   * limitations under the License.
    18   */
    19  
    20  package cmd
    21  
    22  import "syscall"
    23  
    24  // Fallocate uses the linux Fallocate syscall, which helps us to be
    25  // sure that subsequent writes on a file just created will not fail,
    26  // in addition, file allocation will be contigous on the disk
    27  func Fallocate(fd int, offset int64, len int64) error {
    28  	// No need to attempt fallocate for 0 length.
    29  	if len == 0 {
    30  		return nil
    31  	}
    32  	// Don't extend size of file even if offset + len is
    33  	// greater than file size from <bits/fcntl-linux.h>.
    34  	fallocFLKeepSize := uint32(1)
    35  	return syscall.Fallocate(fd, fallocFLKeepSize, offset, len)
    36  }