github.com/pingcap/ticdc@v0.0.0-20220526033649-485a10ef2652/pkg/util/fileutil.go (about)

     1  // Copyright 2020 PingCAP, Inc.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // See the License for the specific language governing permissions and
    12  // limitations under the License.
    13  
    14  package util
    15  
    16  import (
    17  	"fmt"
    18  	"io/ioutil"
    19  	"os"
    20  	"path/filepath"
    21  	"syscall"
    22  
    23  	"github.com/pingcap/errors"
    24  	"github.com/pingcap/failpoint"
    25  	"github.com/pingcap/log"
    26  	"github.com/pingcap/ticdc/pkg/config"
    27  	cerror "github.com/pingcap/ticdc/pkg/errors"
    28  )
    29  
    30  const (
    31  	gb                       = 1024 * 1024 * 1024
    32  	dataDirAvailLowThreshold = 10 // percentage
    33  )
    34  
    35  // IsDirAndWritable checks a given path is directory and writable
    36  func IsDirAndWritable(path string) error {
    37  	st, err := os.Stat(path)
    38  	if err != nil {
    39  		return cerror.WrapError(cerror.ErrCheckDirWritable, err)
    40  	}
    41  	if !st.IsDir() {
    42  		return cerror.WrapError(cerror.ErrCheckDirWritable, errors.Errorf("%s is not a directory", path))
    43  	}
    44  	return IsDirWritable(path)
    45  }
    46  
    47  // IsDirWritable checks if a dir is writable, return error nil means it is writable
    48  func IsDirWritable(dir string) error {
    49  	f := filepath.Join(dir, ".writable.test")
    50  	if err := ioutil.WriteFile(f, []byte(""), 0o600); err != nil {
    51  		return cerror.WrapError(cerror.ErrCheckDirWritable, err)
    52  	}
    53  	return cerror.WrapError(cerror.ErrCheckDirWritable, os.Remove(f))
    54  }
    55  
    56  // IsDirReadWritable check if the dir is writable and readable by cdc server
    57  func IsDirReadWritable(dir string) error {
    58  	f := filepath.Join(dir, "file.test")
    59  	if err := ioutil.WriteFile(f, []byte(""), 0o600); err != nil {
    60  		return cerror.WrapError(cerror.ErrCheckDirValid, err)
    61  	}
    62  
    63  	if _, err := ioutil.ReadFile(f); err != nil {
    64  		return cerror.WrapError(cerror.ErrCheckDirValid, err)
    65  	}
    66  
    67  	return cerror.WrapError(cerror.ErrCheckDirValid, os.Remove(f))
    68  }
    69  
    70  // DiskInfo present the disk amount information, in gb
    71  type DiskInfo struct {
    72  	All             uint64
    73  	Used            uint64
    74  	Free            uint64
    75  	Avail           uint64
    76  	AvailPercentage float32
    77  }
    78  
    79  func (d *DiskInfo) String() string {
    80  	return fmt.Sprintf("{All: %+vGB; Used: %+vGB; Free: %+vGB; Available: %+vGB; Available Percentage: %+v%%}",
    81  		d.All, d.Used, d.Free, d.Avail, d.AvailPercentage)
    82  }
    83  
    84  // GetDiskInfo return the disk space information of the given directory
    85  // the caller should guarantee that dir exist
    86  func GetDiskInfo(dir string) (*DiskInfo, error) {
    87  	f := filepath.Join(dir, "file.test")
    88  	if err := ioutil.WriteFile(f, []byte(""), 0o600); err != nil {
    89  		return nil, cerror.WrapError(cerror.ErrGetDiskInfo, err)
    90  	}
    91  
    92  	fs := syscall.Statfs_t{}
    93  	if err := syscall.Statfs(dir, &fs); err != nil {
    94  		return nil, cerror.WrapError(cerror.ErrGetDiskInfo, err)
    95  	}
    96  
    97  	info := &DiskInfo{
    98  		All:   fs.Blocks * uint64(fs.Bsize) / gb,
    99  		Avail: fs.Bavail * uint64(fs.Bsize) / gb,
   100  		Free:  fs.Bfree * uint64(fs.Bsize) / gb,
   101  	}
   102  	info.Used = info.All - info.Free
   103  	info.AvailPercentage = float32(info.Avail) / float32(info.All) * 100
   104  
   105  	if err := os.Remove(f); err != nil {
   106  		if !os.IsNotExist(err) {
   107  			return info, cerror.WrapError(cerror.ErrGetDiskInfo, err)
   108  		}
   109  	}
   110  
   111  	return info, nil
   112  }
   113  
   114  // CheckDataDirSatisfied check if the data-dir meet the requirement during server running
   115  // the caller should guarantee that dir exist
   116  func CheckDataDirSatisfied() error {
   117  	conf := config.GetGlobalServerConfig()
   118  	diskInfo, err := GetDiskInfo(conf.DataDir)
   119  	if err != nil {
   120  		return cerror.WrapError(cerror.ErrCheckDataDirSatisfied, err)
   121  	}
   122  	if diskInfo.AvailPercentage < dataDirAvailLowThreshold {
   123  		failpoint.Inject("InjectCheckDataDirSatisfied", func() {
   124  			log.Info("inject check data dir satisfied error")
   125  			failpoint.Return(nil)
   126  		})
   127  		return cerror.WrapError(cerror.ErrCheckDataDirSatisfied, errors.Errorf("disk is almost full, TiCDC require that the disk mount data-dir "+
   128  			"have 10%% available space, and the total amount has at least 500GB is preferred. disk info: %+v", diskInfo))
   129  	}
   130  
   131  	return nil
   132  }