VFS_STATFS(9) BSD Kernel Developer's Manual VFS_STATFS(9)NAME
VFS_STATFS -- return file system status
SYNOPSIS
#include <sys/param.h>
#include <sys/mount.h>
#include <sys/vnode.h>
int
VFS_STATFS(struct mount *mp, struct statfs *sbp);
DESCRIPTION
The VFS_STATFS() macro returns various pieces of information about the file system, including recommended I/O sizes, free space, free inodes,
etc.
The arguments it expects are:
mp The file system.
sbp A statfs structure, as defined by <sys/mount.h>, into which information is placed about the file system.
The fields of struct statfs related to the file system are as follows:
f_type Type of file system.
f_flags A copy of mount exported flags.
f_bsize Fragment size.
f_iosize Optimal transfer block size.
f_blocks The total number of data blocks in the file system.
f_bfree The number of free blocks in the file system.
f_bavail The number of free blocks available to non-superuser processes.
f_files The total number of file nodes in the file system.
f_ffree The number of free nodes available to non-superuser processes.
f_syncwrites The number of synchronous writes since the file system was mounted.
f_asyncwrites The number of asynchronous writes since the file system was mounted.
f_syncreads The number of synchronous reads since the file system was mounted.
f_asyncreads The number of asynchronous reads since the file system was mounted.
f_namemax The maximum file name length for this file system.
f_owner The user ID of the user that mounted the file system.
f_fsid Unique file system ID.
f_fstypename The file system type name; a string of at most MFSNAMELEN bytes.
f_mntfromname The device name the file system was mounted from; a string of at most MNAMELEN bytes.
f_mntonname The name of the directory on which the file system is mounted; a string of at most MNAMELEN bytes.
SEE ALSO VFS(9), vnode(9)AUTHORS
This manual page was written by Doug Rabson.
BSD May 23, 2009 BSD
Check Out this Related Man Page
STATFS(2) BSD System Calls Manual STATFS(2)NAME
statfs, statfs64, fstatfs, fstatfs64 -- get file system statistics
SYNOPSIS
#include <sys/param.h>
#include <sys/mount.h>
int
statfs(const char *path, struct statfs *buf);
int
fstatfs(int fd, struct statfs *buf);
TRANSITIONAL SYNOPSIS (NOW DEPRECATED)
int
statfs64(const char *path, struct statfs64 *buf);
int
fstatfs64(int fd, struct statfs64 *buf);
DESCRIPTION
The statfs() routine returns information about a mounted file system. The path argument is the path name of any file or directory within the
mounted file system. The buf argument is a pointer to a statfs structure. When the macro _DARWIN_FEATURE_64_BIT_INODE is not defined (see
stat(2) for more information on this macro), the statfs structure is defined as:
typedef struct { int32_t val[2]; } fsid_t;
#define MFSNAMELEN 15 /* length of fs type name, not inc. nul */
#define MNAMELEN 90 /* length of buffer for returned name */
struct statfs { /* when _DARWIN_FEATURE_64_BIT_INODE is NOT defined */
short f_otype; /* type of file system (reserved: zero) */
short f_oflags; /* copy of mount flags (reserved: zero) */
long f_bsize; /* fundamental file system block size */
long f_iosize; /* optimal transfer block size */
long f_blocks; /* total data blocks in file system */
long f_bfree; /* free blocks in fs */
long f_bavail; /* free blocks avail to non-superuser */
long f_files; /* total file nodes in file system */
long f_ffree; /* free file nodes in fs */
fsid_t f_fsid; /* file system id */
uid_t f_owner; /* user that mounted the file system */
short f_reserved1; /* reserved for future use */
short f_type; /* type of file system (reserved) */
long f_flags; /* copy of mount flags (reserved) */
long f_reserved2[2]; /* reserved for future use */
char f_fstypename[MFSNAMELEN]; /* fs type name */
char f_mntonname[MNAMELEN]; /* directory on which mounted */
char f_mntfromname[MNAMELEN]; /* mounted file system */
char f_reserved3; /* reserved for future use */
long f_reserved4[4]; /* reserved for future use */
};
However, when the macro _DARWIN_FEATURE_64_BIT_INODE is defined, the statfs structure is defined as:
#define MFSTYPENAMELEN 16 /* length of fs type name including null */
#define MAXPATHLEN 1024
#define MNAMELEN MAXPATHLEN
struct statfs { /* when _DARWIN_FEATURE_64_BIT_INODE is defined */
uint32_t f_bsize; /* fundamental file system block size */
int32_t f_iosize; /* optimal transfer block size */
uint64_t f_blocks; /* total data blocks in file system */
uint64_t f_bfree; /* free blocks in fs */
uint64_t f_bavail; /* free blocks avail to non-superuser */
uint64_t f_files; /* total file nodes in file system */
uint64_t f_ffree; /* free file nodes in fs */
fsid_t f_fsid; /* file system id */
uid_t f_owner; /* user that mounted the filesystem */
uint32_t f_type; /* type of filesystem */
uint32_t f_flags; /* copy of mount exported flags */
uint32_t f_fssubtype; /* fs sub-type (flavor) */
char f_fstypename[MFSTYPENAMELEN]; /* fs type name */
char f_mntonname[MAXPATHLEN]; /* directory on which mounted */
char f_mntfromname[MAXPATHLEN]; /* mounted filesystem */
uint32_t f_reserved[8]; /* For future use */
};
Note that the f_fstypename, f_mntonname, and f_mntfromname fields are also wider in this variant.
Fields that are undefined for a particular file system are set to -1. The fstatfs() routine returns the same information about an open file
referenced by descriptor fd.
FLAGS
These are some of the flags that may be present in the f_flags field.
MNT_RDONLY A read-only filesystem
MNT_SYNCHRONOUS File system is written to synchronously
MNT_NOEXEC Can't exec from filesystem
MNT_NOSUID Setuid bits are not honored on this filesystem
MNT_NODEV Don't interpret special files
MNT_UNION Union with underlying filesysten
MNT_ASYNC File system written to asynchronously
MNT_EXPORTED File system is exported
MNT_LOCAL File system is stored locally
MNT_QUOTA Quotas are enabled on this file system
MNT_ROOTFS This file system is the root of the file system
MNT_DOVOLFS File system supports volfs
MNT_DONTBROWSE File system is not appropriate path to user data
MNT_UNKNOWNPERMISSIONS VFS will ignore ownership information on filesystem objects
MNT_AUTOMOUNTED File system was mounted by automounter
MNT_JOURNALED File system is journaled
MNT_DEFWRITE File system should defer writes
MNT_MULTILABEL MAC support for individual labels
MNT_CPROTECT File system supports per-file encrypted data protection
CAVEATS
In Mac OS X versions before 10.4, f_iosize is 4096. On these older systems, use MAXBSIZE instead.
RETURN VALUES
Upon successful completion, a value of 0 is returned. Otherwise, -1 is returned and the global variable errno is set to indicate the error.
ERRORS
The statfs() routine fails if one or more of the following are true:
[ENOTDIR] A component of the path prefix of Path is not a directory.
[ENAMETOOLONG] The length of a component of path exceeds {NAME_MAX} characters, or the length of path exceeds {PATH_MAX} characters.
[ENOENT] The file or directory referred to by path does not exist.
[EACCES] Search permission is denied for a component of the path prefix of path.
[ELOOP] Too many symbolic links were encountered in translating path.
[EFAULT] Buf or path points to an invalid address.
[EIO] An I/O error occurred while reading from or writing to the file system.
The fstatfs() routine fails if one or more of the following are true:
[EBADF] fd is not a valid open file descriptor.
[EFAULT] Buf points to an invalid address.
[EIO] An I/O error occurred while reading from or writing to the file system.
TRANSITIONAL DESCRIPTION (NOW DEPRECATED)
The statfs64 and fstatfs64 routines are equivalent to their corresponding non-64-suffixed routine, when 64-bit inodes are in effect. They
were added before there was support for the symbol variants, and so are now deprecated. Instead of using these, set the
_DARWIN_USE_64_BIT_INODE macro before including header files to force 64-bit inode support.
The statfs64 structure used by these deprecated routines is the same as the statfs structure when 64-bit inodes are in effect (see above).
HISTORY
The statfs() function first appeared in 4.4BSD. The statfs64() and fstatfs64() first appeared in Max OS X 10.5 (Leopard) and are now depre-
cated in favor of the corresponding symbol variants.
BSD August 14, 2008 BSD