removeall_noat.go

     1  // Copyright 2018 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  //go:build !unix
     6  
     7  package os
     8  
     9  import (
    10  	"io"
    11  	"runtime"
    12  	"syscall"
    13  )
    14  
    15  func removeAll(path string) error {
    16  	if path == "" {
    17  		// fail silently to retain compatibility with previous behavior
    18  		// of RemoveAll. See issue 28830.
    19  		return nil
    20  	}
    21  
    22  	// The rmdir system call permits removing "." on Plan 9,
    23  	// so we don't permit it to remain consistent with the
    24  	// "at" implementation of RemoveAll.
    25  	if endsWithDot(path) {
    26  		return &PathError{Op: "RemoveAll", Path: path, Err: syscall.EINVAL}
    27  	}
    28  
    29  	// Simple case: if Remove works, we're done.
    30  	err := Remove(path)
    31  	if err == nil || IsNotExist(err) {
    32  		return nil
    33  	}
    34  
    35  	// Otherwise, is this a directory we need to recurse into?
    36  	dir, serr := Lstat(path)
    37  	if serr != nil {
    38  		if serr, ok := serr.(*PathError); ok && (IsNotExist(serr.Err) || serr.Err == syscall.ENOTDIR) {
    39  			return nil
    40  		}
    41  		return serr
    42  	}
    43  	if !dir.IsDir() {
    44  		// Not a directory; return the error from Remove.
    45  		return err
    46  	}
    47  
    48  	// Remove contents & return first error.
    49  	err = nil
    50  	for {
    51  		fd, err := Open(path)
    52  		if err != nil {
    53  			if IsNotExist(err) {
    54  				// Already deleted by someone else.
    55  				return nil
    56  			}
    57  			return err
    58  		}
    59  
    60  		const reqSize = 1024
    61  		var names []string
    62  		var readErr error
    63  
    64  		for {
    65  			numErr := 0
    66  			names, readErr = fd.Readdirnames(reqSize)
    67  
    68  			for _, name := range names {
    69  				err1 := RemoveAll(path + string(PathSeparator) + name)
    70  				if err == nil {
    71  					err = err1
    72  				}
    73  				if err1 != nil {
    74  					numErr++
    75  				}
    76  			}
    77  
    78  			// If we can delete any entry, break to start new iteration.
    79  			// Otherwise, we discard current names, get next entries and try deleting them.
    80  			if numErr != reqSize {
    81  				break
    82  			}
    83  		}
    84  
    85  		// Removing files from the directory may have caused
    86  		// the OS to reshuffle it. Simply calling Readdirnames
    87  		// again may skip some entries. The only reliable way
    88  		// to avoid this is to close and re-open the
    89  		// directory. See issue 20841.
    90  		fd.Close()
    91  
    92  		if readErr == io.EOF {
    93  			break
    94  		}
    95  		// If Readdirnames returned an error, use it.
    96  		if err == nil {
    97  			err = readErr
    98  		}
    99  		if len(names) == 0 {
   100  			break
   101  		}
   102  
   103  		// We don't want to re-open unnecessarily, so if we
   104  		// got fewer than request names from Readdirnames, try
   105  		// simply removing the directory now. If that
   106  		// succeeds, we are done.
   107  		if len(names) < reqSize {
   108  			err1 := Remove(path)
   109  			if err1 == nil || IsNotExist(err1) {
   110  				return nil
   111  			}
   112  
   113  			if err != nil {
   114  				// We got some error removing the
   115  				// directory contents, and since we
   116  				// read fewer names than we requested
   117  				// there probably aren't more files to
   118  				// remove. Don't loop around to read
   119  				// the directory again. We'll probably
   120  				// just get the same error.
   121  				return err
   122  			}
   123  		}
   124  	}
   125  
   126  	// Remove directory.
   127  	err1 := Remove(path)
   128  	if err1 == nil || IsNotExist(err1) {
   129  		return nil
   130  	}
   131  	if runtime.GOOS == "windows" && IsPermission(err1) {
   132  		if fs, err := Stat(path); err == nil {
   133  			if err = Chmod(path, FileMode(0200|int(fs.Mode()))); err == nil {
   134  				err1 = Remove(path)
   135  			}
   136  		}
   137  	}
   138  	if err == nil {
   139  		err = err1
   140  	}
   141  	return err
   142  }
   143
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