bsd/man/man2/getfsstat.2

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  34 .\"     @(#)getfsstat.2 8.1 (Berkeley) 6/9/93
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  36 .Dd June 9, 1993
  37 .Dt GETFSSTAT 2
  38 .Os
  39 .Sh NAME
  40 .Nm getfsstat
  41 .Nd get list of all mounted file systems
  42 .Sh SYNOPSIS
  43 .Fd #include <sys/param.h>
  44 .Fd #include <sys/ucred.h>
  45 .Fd #include <sys/mount.h>
  46 .Ft int
  47 .Fn getfsstat "struct statfs *buf" "long bufsize" "int flags"
  48 .Sh DESCRIPTION
  49 .Fn Getfsstat
  50 returns information about all mounted file systems.
  51 .Fa Buf
  52 is a pointer to an array of
  53 .Xr statfs
  54 structures defined as follows:
  55 .Bd -literal
  56 typedef struct { int32_t val[2]; } fsid_t;
  57
  58 #define MFSNAMELEN   15 /* length of fs type name, not inc. nul */
  59 #define MNAMELEN     90 /* length of buffer for returned name */
  60
  61 struct statfs {
  62     short   f_otype;    /* type of file system (reserved: zero) */
  63     short   f_oflags;   /* copy of mount flags (reserved: zero) */
  64     long    f_bsize;    /* fundamental file system block size */
  65     long    f_iosize;   /* optimal transfer block size */
  66     long    f_blocks;   /* total data blocks in file system */
  67     long    f_bfree;    /* free blocks in fs */
  68     long    f_bavail;   /* free blocks avail to non-superuser */
  69     long    f_files;    /* total file nodes in file system */
  70     long    f_ffree;    /* free file nodes in fs */
  71     fsid_t  f_fsid;     /* file system id (super-user only) */
  72     uid_t   f_owner;    /* user that mounted the file system */
  73     short   f_reserved1;        /* reserved for future use */
  74     short   f_type;     /* type of file system (reserved) */
  75     long    f_flags;    /* copy of mount flags (reserved) */
  76     long    f_reserved2[2];     /* reserved for future use */
  77     char    f_fstypename[MFSNAMELEN]; /* fs type name */
  78     char    f_mntonname[MNAMELEN];    /* directory on which mounted */
  79     char    f_mntfromname[MNAMELEN];  /* mounted file system */
  80     char    f_reserved3;        /* reserved for future use */
  81     long    f_reserved4[4];     /* reserved for future use */
  82 };
  83 .Ed
  84 .Pp
  85 Fields that are undefined for a particular file system are set to -1.
  86 The buffer is filled with an array of
  87 .Fa statfs
  88 structures, one for each mounted file system
  89 up to the size specified by
  90 .Fa bufsize .
  91 .Pp
  92 If
  93 .Fa buf
  94 is given as NULL,
  95 .Fn getfsstat
  96 returns just the number of mounted file systems.
  97 .Pp
  98 Normally
  99 .Fa flags
 100 should be specified as
 101 .Dv MNT_WAIT .
 102 If
 103 .Fa flags
 104 is set to
 105 .Dv MNT_NOWAIT ,
 106 .Fn getfsstat
 107 will return the information it has available without requesting
 108 an update from each file system.
 109 Thus, some of the information will be out of date, but
 110 .Fn getfsstat
 111 will not block waiting for information from a file system that is
 112 unable to respond.
 113 .Sh RETURN VALUES
 114 Upon successful completion, the number of
 115 .Fa statfs
 116 structures is returned.
 117 Otherwise, -1 is returned and the global variable
 118 .Va errno
 119 is set to indicate the error.
 120 .Sh ERRORS
 121 .Fn Getfsstat
 122 fails if one or more of the following are true:
 123 .Bl -tag -width Er
 124 .It Bq Er EFAULT
 125 .Fa Buf
 126 points to an invalid address.
 127 .It Bq Er EIO
 128 An
 129 .Tn I/O
 130 error occurred while reading from or writing to the file system.
 131 .El
 132 .Sh SEE ALSO
 133 .Xr statfs 2 ,
 134 .Xr fstab 5 ,
 135 .Xr mount 8
 136 .Sh HISTORY
 137 The
 138 .Fn getfsstat
 139 function first appeared in 4.4BSD.