bsd/man/man2/statfs.2

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  34 .\"     @(#)statfs.2    8.3 (Berkeley) 2/11/94
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  36 .Dd August 14, 2008
  37 .Dt STATFS 2
  38 .Os
  39 .Sh NAME
  40 .Nm statfs,
  41 .Nm statfs64,
  42 .Nm fstatfs,
  43 .Nm fstatfs64
  44 .Nd get file system statistics
  45 .Sh SYNOPSIS
  46 .Fd #include <sys/param.h>
  47 .Fd #include <sys/mount.h>
  48 .Ft int
  49 .Fn statfs "const char *path" "struct statfs *buf"
  50 .Ft int
  51 .Fn fstatfs "int fd" "struct statfs *buf"
  52 .Sh TRANSITIIONAL SYNOPSIS (NOW DEPRECATED)
  53 .Ft int
  54 .br
  55 .Fn statfs64 "const char *path" "struct statfs64 *buf" ;
  56 .sp
  57 .Ft int
  58 .br
  59 .Fn fstatfs64 "int fd" "struct statfs64 *buf" ;
  60 .Sh DESCRIPTION
  61 The
  62 .Fn statfs
  63 routine returns information about a mounted file system.
  64 The
  65 .Fa path
  66 argument is the path name of any file or directory within the mounted file system.
  67 The
  68 .Fa buf
  69 argument is a pointer to a
  70 .Fa statfs
  71 structure.
  72 When the macro
  73 .Dv _DARWIN_FEATURE_64_BIT_INODE
  74 is not defined (the
  75 .Ft ino_t
  76 type is 32-bits), that structure is defined as:
  77 .Bd -literal
  78 typedef struct { int32_t val[2]; } fsid_t;
  79
  80 #define MFSNAMELEN      15 /* length of fs type name, not inc. nul */
  81 #define MNAMELEN        90 /* length of buffer for returned name */
  82
  83 struct statfs { /* when _DARWIN_FEATURE_64_BIT_INODE is NOT defined */
  84     short   f_otype;    /* type of file system (reserved: zero) */
  85     short   f_oflags;   /* copy of mount flags (reserved: zero) */
  86     long    f_bsize;    /* fundamental file system block size */
  87     long    f_iosize;   /* optimal transfer block size */
  88     long    f_blocks;   /* total data blocks in file system */
  89     long    f_bfree;    /* free blocks in fs */
  90     long    f_bavail;   /* free blocks avail to non-superuser */
  91     long    f_files;    /* total file nodes in file system */
  92     long    f_ffree;    /* free file nodes in fs */
  93     fsid_t  f_fsid;     /* file system id */
  94     uid_t   f_owner;    /* user that mounted the file system */
  95     short   f_reserved1;        /* reserved for future use */
  96     short   f_type;     /* type of file system (reserved) */
  97     long    f_flags;    /* copy of mount flags (reserved) */
  98     long    f_reserved2[2];     /* reserved for future use */
  99     char    f_fstypename[MFSNAMELEN]; /* fs type name */
 100     char    f_mntonname[MNAMELEN];    /* directory on which mounted */
 101     char    f_mntfromname[MNAMELEN];  /* mounted file system */
 102     char    f_reserved3;        /* reserved for future use */
 103     long    f_reserved4[4];     /* reserved for future use */
 104 };
 105 .Ed
 106 .Pp
 107 However, when the macro
 108 .Dv _DARWIN_FEATURE_64_BIT_INODE
 109 is defined, the
 110 .Ft ino_t
 111 type will be 64-bits (force 64-bit inode mode by defining the
 112 .Dv _DARWIN_USE_64_BIT_INODE
 113 macro before including header files).
 114 This will cause symbol variants of the
 115 .Fa statfs
 116 family, with the
 117 .Fa $INODE64
 118 suffixes, to be automatically linked in.
 119 In addition, the
 120 .Fa statfs
 121 structure will now be defined as:
 122 .Bd -literal
 123 #define MFSTYPENAMELEN  16 /* length of fs type name including null */
 124 #define MAXPATHLEN      1024
 125 #define MNAMELEN        MAXPATHLEN
 126
 127 struct statfs { /* when _DARWIN_FEATURE_64_BIT_INODE is defined */
 128     uint32_t    f_bsize;        /* fundamental file system block size */
 129     int32_t     f_iosize;       /* optimal transfer block size */
 130     uint64_t    f_blocks;       /* total data blocks in file system */
 131     uint64_t    f_bfree;        /* free blocks in fs */
 132     uint64_t    f_bavail;       /* free blocks avail to non-superuser */
 133     uint64_t    f_files;        /* total file nodes in file system */
 134     uint64_t    f_ffree;        /* free file nodes in fs */
 135     fsid_t      f_fsid;         /* file system id */
 136     uid_t       f_owner;        /* user that mounted the filesystem */
 137     uint32_t    f_type;         /* type of filesystem */
 138     uint32_t    f_flags;        /* copy of mount exported flags */
 139     uint32_t    f_fssubtype;    /* fs sub-type (flavor) */
 140     char        f_fstypename[MFSTYPENAMELEN];   /* fs type name */
 141     char        f_mntonname[MAXPATHLEN];        /* directory on which mounted */
 142     char        f_mntfromname[MAXPATHLEN];      /* mounted filesystem */
 143     uint32_t    f_reserved[8];  /* For future use */
 144 };
 145 .Ed
 146 .Pp
 147 Fields that are undefined for a particular file system are set to -1.
 148 The
 149 .Fn fstatfs
 150 routine returns the same information about an open file referenced by descriptor
 151 .Fa fd .
 152 .Sh FLAGS
 153 .Bl -tag -width MNT_UNKOWNPERMISSIONS
 154 These are some of the flags that may be present in the f_flags field.
 155 .It Dv MNT_RDONLY
 156 A read-only filesystem
 157 .It Dv MNT_SYNCHRONOUS
 158 File system is written to synchronously
 159 .It Dv MNT_NOEXEC
 160 Can't exec from filesystem
 161 .It Dv MNT_NOSUID
 162 Setuid bits are not honored on this filesystem
 163 .It Dv MNT_NODEV
 164 Don't interpret special files
 165 .It Dv MNT_UNION
 166 Union with underlying filesysten
 167 .It Dv MNT_ASYNC
 168 File system written to asynchronously
 169 .It Dv MNT_EXPORTED
 170 File system is exported
 171 .It Dv MNT_LOCAL
 172 File system is stored locally
 173 .It Dv MNT_QUOTA
 174 Quotas are enabled on this file system
 175 .It Dv MNT_ROOTFS
 176 This file system is the root of the file system
 177 .It Dv MNT_DOVOLFS
 178 File system supports volfs
 179 .It Dv MNT_DONTBROWSE
 180 File system is not appropriate path to user data
 181 .It Dv MNT_UNKNOWNPERMISSIONS
 182 VFS will ignore ownership information on filesystem objects
 183 .It Dv MNT_AUTOMOUNTED
 184 File system was mounted by automounter
 185 .It Dv MNT_JOURNALED
 186 File system is journaled
 187 .It Dv MNT_DEFWRITE
 188 File system should defer writes
 189 .It Dv MNT_MULTILABEL
 190 MAC support for individual labels
 191 .El
 192 .Sh CAVEATS
 193 In Mac OS X versions before 10.4, f_iosize is 4096. On these older
 194 systems, use MAXBSIZE instead.
 195 .Sh RETURN VALUES
 196 Upon successful completion, a value of 0 is returned.
 197 Otherwise, -1 is returned and the global variable
 198 .Va errno
 199 is set to indicate the error.
 200 .Sh ERRORS
 201 The
 202 .Fn statfs
 203 routine fails if one or more of the following are true:
 204 .Bl -tag -width Er
 205 .It Bq Er ENOTDIR
 206 A component of the path prefix of
 207 .Fa Path
 208 is not a directory.
 209 .It Bq Er ENAMETOOLONG
 210 The length of a component of
 211 .Fa path
 212 exceeds
 213 .Dv {NAME_MAX}
 214 characters, or the length of
 215 .Fa path
 216 exceeds
 217 .Dv {PATH_MAX}
 218 characters.
 219 .It Bq Er ENOENT
 220 The file or directory referred to by
 221 .Fa path
 222 does not exist.
 223 .It Bq Er EACCES
 224 Search permission is denied for a component of the path prefix of
 225 .Fa path .
 226 .It Bq Er ELOOP
 227 Too many symbolic links were encountered in translating
 228 .Fa path .
 229 .It Bq Er EFAULT
 230 .Fa Buf
 231 or
 232 .Fa path
 233 points to an invalid address.
 234 .It Bq Er EIO
 235 An
 236 .Tn I/O
 237 error occurred while reading from or writing to the file system.
 238 .El
 239 .Pp
 240 The
 241 .Fn fstatfs
 242 routine fails if one or more of the following are true:
 243 .Bl -tag -width Er
 244 .It Bq Er EBADF
 245 .Fa fd
 246 is not a valid open file descriptor.
 247 .It Bq Er EFAULT
 248 .Fa Buf
 249 points to an invalid address.
 250 .It Bq Er EIO
 251 An
 252 .Tn I/O
 253 error occurred while reading from or writing to the file system.
 254 .El
 255 .Sh TRANSITIONAL DESCRIPTION (NOW DEPRECATED)
 256 The
 257 .Fa statfs64
 258 and
 259 .Fa fstatfs64
 260 routines are equivalent to their corresponding non-64-suffixed routine,
 261 when 64-bit inodes are in effect.
 262 They were added before there was support for the symbol variants, and so are
 263 now deprecated.
 264 Instead of using these, set the
 265 .Dv _DARWIN_USE_64_BIT_INODE
 266 macro before including header files to force 64-bit inode support.
 267 .Pp
 268 The
 269 .Fa statfs64
 270 structure used by these deprecated routines is the same as the
 271 .Fa statfs
 272 structure when 64-bit inodes are in effect (see above).
 273 .Sh HISTORY
 274 The
 275 .Fn statfs
 276 function first appeared in 4.4BSD. The
 277 .Fn statfs64
 278 and
 279 .Fn fstatfs64
 280 first appeared in Max OS X 10.5 (Leopard) and are now deprecated
 281 in favor of the corresponding symbol variants.