fstatfs_zos.go

     1  // Copyright 2020 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 zos && s390x
     6  // +build zos,s390x
     7  
     8  package unix
     9  
    10  import (
    11  	"unsafe"
    12  )
    13  
    14  // This file simulates fstatfs on z/OS using fstatvfs and w_getmntent.
    15  
    16  func Fstatfs(fd int, stat *Statfs_t) (err error) {
    17  	var stat_v Statvfs_t
    18  	err = Fstatvfs(fd, &stat_v)
    19  	if err == nil {
    20  		// populate stat
    21  		stat.Type = 0
    22  		stat.Bsize = stat_v.Bsize
    23  		stat.Blocks = stat_v.Blocks
    24  		stat.Bfree = stat_v.Bfree
    25  		stat.Bavail = stat_v.Bavail
    26  		stat.Files = stat_v.Files
    27  		stat.Ffree = stat_v.Ffree
    28  		stat.Fsid = stat_v.Fsid
    29  		stat.Namelen = stat_v.Namemax
    30  		stat.Frsize = stat_v.Frsize
    31  		stat.Flags = stat_v.Flag
    32  		for passn := 0; passn < 5; passn++ {
    33  			switch passn {
    34  			case 0:
    35  				err = tryGetmntent64(stat)
    36  				break
    37  			case 1:
    38  				err = tryGetmntent128(stat)
    39  				break
    40  			case 2:
    41  				err = tryGetmntent256(stat)
    42  				break
    43  			case 3:
    44  				err = tryGetmntent512(stat)
    45  				break
    46  			case 4:
    47  				err = tryGetmntent1024(stat)
    48  				break
    49  			default:
    50  				break
    51  			}
    52  			//proceed to return if: err is nil (found), err is nonnil but not ERANGE (another error occurred)
    53  			if err == nil || err != nil && err != ERANGE {
    54  				break
    55  			}
    56  		}
    57  	}
    58  	return err
    59  }
    60  
    61  func tryGetmntent64(stat *Statfs_t) (err error) {
    62  	var mnt_ent_buffer struct {
    63  		header       W_Mnth
    64  		filesys_info [64]W_Mntent
    65  	}
    66  	var buffer_size int = int(unsafe.Sizeof(mnt_ent_buffer))
    67  	fs_count, err := W_Getmntent((*byte)(unsafe.Pointer(&mnt_ent_buffer)), buffer_size)
    68  	if err != nil {
    69  		return err
    70  	}
    71  	err = ERANGE //return ERANGE if no match is found in this batch
    72  	for i := 0; i < fs_count; i++ {
    73  		if stat.Fsid == uint64(mnt_ent_buffer.filesys_info[i].Dev) {
    74  			stat.Type = uint32(mnt_ent_buffer.filesys_info[i].Fstname[0])
    75  			err = nil
    76  			break
    77  		}
    78  	}
    79  	return err
    80  }
    81  
    82  func tryGetmntent128(stat *Statfs_t) (err error) {
    83  	var mnt_ent_buffer struct {
    84  		header       W_Mnth
    85  		filesys_info [128]W_Mntent
    86  	}
    87  	var buffer_size int = int(unsafe.Sizeof(mnt_ent_buffer))
    88  	fs_count, err := W_Getmntent((*byte)(unsafe.Pointer(&mnt_ent_buffer)), buffer_size)
    89  	if err != nil {
    90  		return err
    91  	}
    92  	err = ERANGE //return ERANGE if no match is found in this batch
    93  	for i := 0; i < fs_count; i++ {
    94  		if stat.Fsid == uint64(mnt_ent_buffer.filesys_info[i].Dev) {
    95  			stat.Type = uint32(mnt_ent_buffer.filesys_info[i].Fstname[0])
    96  			err = nil
    97  			break
    98  		}
    99  	}
   100  	return err
   101  }
   102  
   103  func tryGetmntent256(stat *Statfs_t) (err error) {
   104  	var mnt_ent_buffer struct {
   105  		header       W_Mnth
   106  		filesys_info [256]W_Mntent
   107  	}
   108  	var buffer_size int = int(unsafe.Sizeof(mnt_ent_buffer))
   109  	fs_count, err := W_Getmntent((*byte)(unsafe.Pointer(&mnt_ent_buffer)), buffer_size)
   110  	if err != nil {
   111  		return err
   112  	}
   113  	err = ERANGE //return ERANGE if no match is found in this batch
   114  	for i := 0; i < fs_count; i++ {
   115  		if stat.Fsid == uint64(mnt_ent_buffer.filesys_info[i].Dev) {
   116  			stat.Type = uint32(mnt_ent_buffer.filesys_info[i].Fstname[0])
   117  			err = nil
   118  			break
   119  		}
   120  	}
   121  	return err
   122  }
   123  
   124  func tryGetmntent512(stat *Statfs_t) (err error) {
   125  	var mnt_ent_buffer struct {
   126  		header       W_Mnth
   127  		filesys_info [512]W_Mntent
   128  	}
   129  	var buffer_size int = int(unsafe.Sizeof(mnt_ent_buffer))
   130  	fs_count, err := W_Getmntent((*byte)(unsafe.Pointer(&mnt_ent_buffer)), buffer_size)
   131  	if err != nil {
   132  		return err
   133  	}
   134  	err = ERANGE //return ERANGE if no match is found in this batch
   135  	for i := 0; i < fs_count; i++ {
   136  		if stat.Fsid == uint64(mnt_ent_buffer.filesys_info[i].Dev) {
   137  			stat.Type = uint32(mnt_ent_buffer.filesys_info[i].Fstname[0])
   138  			err = nil
   139  			break
   140  		}
   141  	}
   142  	return err
   143  }
   144  
   145  func tryGetmntent1024(stat *Statfs_t) (err error) {
   146  	var mnt_ent_buffer struct {
   147  		header       W_Mnth
   148  		filesys_info [1024]W_Mntent
   149  	}
   150  	var buffer_size int = int(unsafe.Sizeof(mnt_ent_buffer))
   151  	fs_count, err := W_Getmntent((*byte)(unsafe.Pointer(&mnt_ent_buffer)), buffer_size)
   152  	if err != nil {
   153  		return err
   154  	}
   155  	err = ERANGE //return ERANGE if no match is found in this batch
   156  	for i := 0; i < fs_count; i++ {
   157  		if stat.Fsid == uint64(mnt_ent_buffer.filesys_info[i].Dev) {
   158  			stat.Type = uint32(mnt_ent_buffer.filesys_info[i].Fstname[0])
   159  			err = nil
   160  			break
   161  		}
   162  	}
   163  	return err
   164  }
   165
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