bsd/man/man2/getfsstat.2

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  34 .\"     @(#)getfsstat.2 8.1 (Berkeley) 6/9/93
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  36 .Dd Oct 28, 2008
  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" "int bufsize" "int flags"
  48 .Sh TRANSITIIONAL SYNOPSIS (NOW DEPRECATED)
  49 .Ft int
  50 .br
  51 .Fn getfsstat64 "struct statfs64 *buf" "int bufsize" "int flags" ;
  52 .Sh DESCRIPTION
  53 The
  54 .Fn getfsstat
  55 function returns information about all mounted file systems.
  56 The
  57 .Fa buf
  58 argument is a pointer to an array of
  59 .Xr statfs
  60 structures.
  61 .Pp
  62 As of Mac OS X 10.6, the default size of the
  63 .Ft ino_t
  64 type is 64 bits (the macro
  65 .Dv _DARWIN_FEATURE_64_BIT_INODE
  66 will be defined).
  67 While there is no
  68 .Ft ino_t
  69 type used in the
  70 .Xr statfs
  71 structure, the changes to
  72 .Fn getfsstat
  73 are grouped together with the 64-bit inode changes.
  74 The string fields in the
  75 .Xr statfs
  76 structure are larger and the variant symbol
  77 .Li _getfsstat$INODE64
  78 will be automatically used.
  79 The
  80 .Xr statfs
  81 structure is defined as:
  82 .Bd -literal
  83 typedef struct { int32_t val[2]; } fsid_t;
  84
  85 #define MFSTYPENAMELEN  16 /* length of fs type name including null */
  86 #define MAXPATHLEN      1024
  87 #define MNAMELEN        MAXPATHLEN
  88
  89 struct statfs { /* when _DARWIN_FEATURE_64_BIT_INODE is defined */
  90     uint32_t    f_bsize;        /* fundamental file system block size */
  91     int32_t     f_iosize;       /* optimal transfer block size */
  92     uint64_t    f_blocks;       /* total data blocks in file system */
  93     uint64_t    f_bfree;        /* free blocks in fs */
  94     uint64_t    f_bavail;       /* free blocks avail to non-superuser */
  95     uint64_t    f_files;        /* total file nodes in file system */
  96     uint64_t    f_ffree;        /* free file nodes in fs */
  97     fsid_t      f_fsid;         /* file system id */
  98     uid_t       f_owner;        /* user that mounted the filesystem */
  99     uint32_t    f_type;         /* type of filesystem */
 100     uint32_t    f_flags;        /* copy of mount exported flags */
 101     uint32_t    f_fssubtype;    /* fs sub-type (flavor) */
 102     char        f_fstypename[MFSTYPENAMELEN];   /* fs type name */
 103     char        f_mntonname[MAXPATHLEN];        /* directory on which mounted */
 104     char        f_mntfromname[MAXPATHLEN];      /* mounted filesystem */
 105     uint32_t    f_reserved[8];  /* For future use */
 106 };
 107 .Ed
 108 .Pp
 109 (In 10.5, 64-bit
 110 .Ft ino_t ,
 111 larger
 112 .Xr statfs
 113 structure and variant symbol were available if the macro
 114 .Dv _DARWIN_USE_64_BIT_INODE
 115 is defined before any header files are included; this macro is optional in
 116 10.6.)
 117 .Pp
 118 If the macro
 119 .Dv _DARWIN_NO_64_BIT_INODE
 120 is defined before any header files are included, or if the deployment target
 121 is less than 10.6, the legacy
 122 .Xr statfs
 123 structure will be in effect.
 124 The
 125 .Ft ino_t
 126 type will be 32 bits (the
 127 .Dv _DARWIN_FEATURE_64_BIT_INODE
 128 macro will not be defined), the strings in the
 129 .Xr statfs
 130 structure will be their smaller legacy size (and long mount paths may no longer
 131 fit) and the undecorated symbol
 132 .Li _getfsstat
 133 will be used.
 134 This legacy
 135 .Fa statfs
 136 structure is defined as:
 137 .Bd -literal
 138 #define MFSNAMELEN      15 /* length of fs type name, not inc. nul */
 139 #define MNAMELEN        90 /* length of buffer for returned name */
 140
 141 struct statfs { /* when _DARWIN_FEATURE_64_BIT_INODE is NOT defined */
 142     short   f_otype;    /* type of file system (reserved: zero) */
 143     short   f_oflags;   /* copy of mount flags (reserved: zero) */
 144     long    f_bsize;    /* fundamental file system block size */
 145     long    f_iosize;   /* optimal transfer block size */
 146     long    f_blocks;   /* total data blocks in file system */
 147     long    f_bfree;    /* free blocks in fs */
 148     long    f_bavail;   /* free blocks avail to non-superuser */
 149     long    f_files;    /* total file nodes in file system */
 150     long    f_ffree;    /* free file nodes in fs */
 151     fsid_t  f_fsid;     /* file system id */
 152     uid_t   f_owner;    /* user that mounted the file system */
 153     short   f_reserved1;        /* reserved for future use */
 154     short   f_type;     /* type of file system (reserved) */
 155     long    f_flags;    /* copy of mount flags (reserved) */
 156     long    f_reserved2[2];     /* reserved for future use */
 157     char    f_fstypename[MFSNAMELEN]; /* fs type name */
 158     char    f_mntonname[MNAMELEN];    /* directory on which mounted */
 159     char    f_mntfromname[MNAMELEN];  /* mounted file system */
 160     char    f_reserved3;        /* reserved for future use */
 161     long    f_reserved4[4];     /* reserved for future use */
 162 };
 163 .Ed
 164 .Pp
 165 Fields that are undefined for a particular file system are set to -1.
 166 The buffer is filled with an array of
 167 .Fa statfs
 168 structures, one for each mounted file system
 169 up to the size specified by
 170 .Fa bufsize .
 171 .Pp
 172 If
 173 .Fa buf
 174 is given as NULL,
 175 .Fn getfsstat
 176 returns just the number of mounted file systems.
 177 .Pp
 178 If
 179 .Fa flags
 180 is set to
 181 .Dv MNT_NOWAIT ,
 182 .Fn getfsstat
 183 will directly return the information retained in the kernel
 184 to avoid delays caused by waiting for updated information from
 185 a file system that is perhaps temporarily unable to respond.
 186 Some of the information returned may be out of date, however; if
 187 .Fa flags
 188 is set to
 189 .Dv MNT_WAIT
 190 or
 191 .Dv MNT_DWAIT
 192 instead,
 193 .Fn getfsstat
 194 will request updated information from each mounted filesystem before
 195 returning.
 196 .Sh RETURN VALUES
 197 Upon successful completion, the number of
 198 .Fa statfs
 199 structures is returned.
 200 Otherwise, -1 is returned and the global variable
 201 .Va errno
 202 is set to indicate the error.
 203 .Sh ERRORS
 204 .Fn Getfsstat
 205 fails if one or more of the following are true:
 206 .Bl -tag -width Er
 207 .It Bq Er EFAULT
 208 The
 209 .Fa buf
 210 argument points to an invalid address.
 211 .It Bq Er EIO
 212 An
 213 .Tn I/O
 214 error occurred while reading from or writing to the file system.
 215 .El
 216 .Sh TRANSITIONAL DESCRIPTION (NOW DEPRECATED)
 217 The
 218 .Fn getfsstat64
 219 routine is equivalent to the default
 220 .Fn getfstat
 221 (when
 222 .Dv _DARWIN_FEATURE_64_BIT_INODE
 223 is defined), so there is no longer any reason to use it (it will be removed
 224 in the future).
 225 .Sh SEE ALSO
 226 .Xr statfs 2 ,
 227 .Xr fstab 5 ,
 228 .Xr mount 8
 229 .Sh HISTORY
 230 The
 231 .Fn getfsstat
 232 function first appeared in 4.4BSD.