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