The
<sys/statvfs.h> header defines the structures and functions that return information about a mounted file system. The
statvfs structure is defined as follows:
typedef struct { int32_t val[2]; } fsid_t; /* file system id type */
#define VFS_NAMELEN 32 /* length of fs type name, including nul */
#define VFS_MNAMELEN 1024 /* length of buffer for returned name */
struct statvfs {
unsigned long f_flag; /* copy of mount exported flags */
unsigned long f_bsize; /* system block size */
unsigned long f_frsize; /* system fragment size */
unsigned long f_iosize; /* optimal file system block size */
fsblkcnt_t f_blocks; /* number of blocks in file system */
fsblkcnt_t f_bfree; /* free blocks avail in file system */
fsblkcnt_t f_bavail; /* free blocks avail to non-root */
fsblkcnt_t f_bresvd; /* blocks reserved for root */
fsfilcnt_t f_files; /* total file nodes in file system */
fsfilcnt_t f_ffree; /* free file nodes in file system */
fsfilcnt_t f_favail; /* free file nodes avail to non-root */
fsfilcnt_t f_fresvd; /* file nodes reserved for root */
uint64_t f_syncreads; /* count of sync reads since mount */
uint64_t f_syncwrites; /* count of sync writes since mount */
uint64_t f_asyncreads; /* count of async reads since mount */
uint64_t f_asyncwrites; /* count of async writes since mount */
unsigned long f_fsid; /* POSIX compliant file system id */
fsid_t f_fsidx; /* NetBSD compatible file system id */
unsigned long f_namemax;/* maximum filename length */
uid_t f_owner; /* user that mounted the file system */
uint32_t f_spare[4]; /* spare space */
char f_fstypename[VFS_NAMELEN]; /* fs type name */
char f_mntonname[VFS_MNAMELEN]; /* directory on which mounted */
char f_mntfromname[VFS_MNAMELEN]; /* mounted file system */
};
The
f_flag argument can have the following bits set:
ST_RDONLY
The filesystem is mounted read-only; Even the super-user may not write on it.
ST_NOEXEC
Files may not be executed from the filesystem.
ST_NOSUID
Setuid and setgid bits on files are not honored when they are executed.
ST_NODEV
Special files in the filesystem may not be opened.
ST_UNION
Union with underlying filesystem instead of obscuring it.
ST_SYNCHRONOUS
All I/O to the filesystem is done synchronously.
ST_ASYNC
No filesystem I/O is done synchronously.
ST_NOCOREDUMP
Don't write core dumps to this file system.
ST_NOATIME
Never update access times.
ST_SYMPERM
Recognize symbolic link permission.
ST_NODEVMTIME
Never update modification times for device files.
ST_LOG
Use logging (journalling).
ST_LOCAL
The filesystem resides locally.
ST_QUOTA
The filesystem has quotas enabled on it.
ST_ROOTFS
Identifies the root filesystem.
ST_EXRDONLY
The filesystem is exported read-only.
ST_EXPORTED
The filesystem is exported for both reading and writing.
ST_DEFEXPORTED
The filesystem is exported for both reading and writing to any Internet host.
ST_EXPORTANON
The filesystem maps all remote accesses to the anonymous user.
ST_EXKERB
The filesystem is exported with Kerberos uid mapping.
ST_EXNORESPORT
Don't enforce reserved ports (NFS).
ST_EXPUBLIC
Public export (WebNFS).
Fields that are undefined for a particular file system are set to -1.