github.com/Cloud-Foundations/Dominator@v0.3.4/lib/filesystem/write.go (about)

     1  package filesystem
     2  
     3  import (
     4  	"errors"
     5  	"os"
     6  	"syscall"
     7  	"time"
     8  
     9  	"github.com/Cloud-Foundations/Dominator/lib/fsutil"
    10  )
    11  
    12  var modePerm FileMode = syscall.S_IRWXU | syscall.S_IRWXG | syscall.S_IRWXO
    13  
    14  func forceWriteMetadata(inode GenericInode, name string) error {
    15  	err := inode.WriteMetadata(name)
    16  	if err == nil {
    17  		return nil
    18  	}
    19  	if os.IsPermission(err) {
    20  		// Blindly attempt to remove immutable attributes.
    21  		fsutil.MakeMutable(name)
    22  	}
    23  	return inode.WriteMetadata(name)
    24  }
    25  
    26  func (inode *DirectoryInode) write(name string) error {
    27  	if err := inode.make(name); err != nil {
    28  		// If existing directory, don't blow it away, just update metadata.
    29  		if os.IsExist(err) {
    30  			if fi, err := os.Lstat(name); err == nil && fi.IsDir() {
    31  				return inode.writeMetadata(name)
    32  			}
    33  		}
    34  		fsutil.ForceRemoveAll(name)
    35  		if err := inode.make(name); err != nil {
    36  			return err
    37  		}
    38  	}
    39  	return inode.writeMetadata(name)
    40  }
    41  
    42  func (inode *DirectoryInode) make(name string) error {
    43  	return syscall.Mkdir(name, uint32(inode.Mode))
    44  }
    45  
    46  func (inode *DirectoryInode) writeMetadata(name string) error {
    47  	if err := os.Lchown(name, int(inode.Uid), int(inode.Gid)); err != nil {
    48  		return err
    49  	}
    50  	return syscall.Chmod(name, uint32(inode.Mode))
    51  }
    52  
    53  func (inode *RegularInode) writeMetadata(name string) error {
    54  	if err := os.Lchown(name, int(inode.Uid), int(inode.Gid)); err != nil {
    55  		return err
    56  	}
    57  	if err := syscall.Chmod(name, uint32(inode.Mode)); err != nil {
    58  		return err
    59  	}
    60  	t := time.Unix(inode.MtimeSeconds, int64(inode.MtimeNanoSeconds))
    61  	return os.Chtimes(name, t, t)
    62  }
    63  
    64  func (inode *SymlinkInode) write(name string) error {
    65  	if inode.make(name) != nil {
    66  		fsutil.ForceRemoveAll(name)
    67  		if err := inode.make(name); err != nil {
    68  			return err
    69  		}
    70  	}
    71  	return inode.writeMetadata(name)
    72  }
    73  
    74  func (inode *SymlinkInode) make(name string) error {
    75  	return os.Symlink(inode.Symlink, name)
    76  }
    77  
    78  func (inode *SymlinkInode) writeMetadata(name string) error {
    79  	return os.Lchown(name, int(inode.Uid), int(inode.Gid))
    80  }
    81  
    82  func (inode *SpecialInode) write(name string) error {
    83  	if inode.make(name) != nil {
    84  		fsutil.ForceRemoveAll(name)
    85  		if err := inode.make(name); err != nil {
    86  			return err
    87  		}
    88  	}
    89  	return inode.writeMetadata(name)
    90  }
    91  
    92  func (inode *SpecialInode) make(name string) error {
    93  	if inode.Mode&syscall.S_IFBLK != 0 || inode.Mode&syscall.S_IFCHR != 0 {
    94  		return syscall.Mknod(name, uint32(inode.Mode), int(inode.Rdev))
    95  	} else if inode.Mode&syscall.S_IFIFO != 0 {
    96  		return syscall.Mkfifo(name, uint32(inode.Mode))
    97  	} else {
    98  		return errors.New("unsupported mode")
    99  	}
   100  }
   101  
   102  func (inode *SpecialInode) writeMetadata(name string) error {
   103  	if err := os.Lchown(name, int(inode.Uid), int(inode.Gid)); err != nil {
   104  		return err
   105  	}
   106  	if err := syscall.Chmod(name, uint32(inode.Mode)); err != nil {
   107  		return err
   108  	}
   109  	t := time.Unix(inode.MtimeSeconds, int64(inode.MtimeNanoSeconds))
   110  	return os.Chtimes(name, t, t)
   111  }