github.com/minio/minio@v0.0.0-20240328213742-3f72439b8a27/internal/lock/lock_solaris.go (about)

     1  //go:build solaris
     2  // +build solaris
     3  
     4  // Copyright (c) 2015-2021 MinIO, Inc.
     5  //
     6  // This file is part of MinIO Object Storage stack
     7  //
     8  // This program is free software: you can redistribute it and/or modify
     9  // it under the terms of the GNU Affero General Public License as published by
    10  // the Free Software Foundation, either version 3 of the License, or
    11  // (at your option) any later version.
    12  //
    13  // This program is distributed in the hope that it will be useful
    14  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    15  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    16  // GNU Affero General Public License for more details.
    17  //
    18  // You should have received a copy of the GNU Affero General Public License
    19  // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    20  
    21  package lock
    22  
    23  import (
    24  	"os"
    25  	"syscall"
    26  )
    27  
    28  // lockedOpenFile is an internal function.
    29  func lockedOpenFile(path string, flag int, perm os.FileMode, rlockType int) (*LockedFile, error) {
    30  	var lockType int16
    31  	switch flag {
    32  	case syscall.O_RDONLY:
    33  		lockType = syscall.F_RDLCK
    34  	case syscall.O_WRONLY:
    35  		fallthrough
    36  	case syscall.O_RDWR:
    37  		fallthrough
    38  	case syscall.O_WRONLY | syscall.O_CREAT:
    39  		fallthrough
    40  	case syscall.O_RDWR | syscall.O_CREAT:
    41  		lockType = syscall.F_WRLCK
    42  	default:
    43  		return nil, &os.PathError{
    44  			Op:   "open",
    45  			Path: path,
    46  			Err:  syscall.EINVAL,
    47  		}
    48  	}
    49  
    50  	lock := syscall.Flock_t{
    51  		Start:  0,
    52  		Len:    0,
    53  		Pid:    0,
    54  		Type:   lockType,
    55  		Whence: 0,
    56  	}
    57  
    58  	f, err := os.OpenFile(path, flag, perm)
    59  	if err != nil {
    60  		return nil, err
    61  	}
    62  
    63  	if err = syscall.FcntlFlock(f.Fd(), rlockType, &lock); err != nil {
    64  		f.Close()
    65  		if err == syscall.EAGAIN {
    66  			err = ErrAlreadyLocked
    67  		}
    68  		return nil, err
    69  	}
    70  
    71  	st, err := os.Stat(path)
    72  	if err != nil {
    73  		f.Close()
    74  		return nil, err
    75  	}
    76  
    77  	if st.IsDir() {
    78  		f.Close()
    79  		return nil, &os.PathError{
    80  			Op:   "open",
    81  			Path: path,
    82  			Err:  syscall.EISDIR,
    83  		}
    84  	}
    85  
    86  	return &LockedFile{f}, nil
    87  }
    88  
    89  // TryLockedOpenFile - tries a new write lock, functionality
    90  // it is similar to LockedOpenFile with with syscall.LOCK_EX
    91  // mode but along with syscall.LOCK_NB such that the function
    92  // doesn't wait forever but instead returns if it cannot
    93  // acquire a write lock.
    94  func TryLockedOpenFile(path string, flag int, perm os.FileMode) (*LockedFile, error) {
    95  	return lockedOpenFile(path, flag, perm, syscall.F_SETLK)
    96  }
    97  
    98  // LockedOpenFile - initializes a new lock and protects
    99  // the file from concurrent access across mount points.
   100  // This implementation doesn't support all the open
   101  // flags and shouldn't be considered as replacement
   102  // for os.OpenFile().
   103  func LockedOpenFile(path string, flag int, perm os.FileMode) (*LockedFile, error) {
   104  	return lockedOpenFile(path, flag, perm, syscall.F_SETLKW)
   105  }
   106  
   107  // Open - Call os.OpenFile
   108  func Open(path string, flag int, perm os.FileMode) (*os.File, error) {
   109  	return os.OpenFile(path, flag, perm)
   110  }