NAME
getfsstat —
get list of all mounted file
systems
SYNOPSIS
#include
<sys/types.h>
#include <sys/mount.h>
int
getfsstat(struct
statfs *buf, size_t
bufsize, int
flags);
DESCRIPTION
getfsstat()
returns information about all mounted file systems.
buf is a pointer to an array of
statfs(2)
structures defined as follows:
typedef struct { int32_t val[2]; } fsid_t;
#define MFSNAMELEN 16 /* length of fs type name, including nul */
#define MNAMELEN 90 /* length of buffer for returned name */
struct statfs {
u_int32_t f_flags; /* copy of mount flags */
u_int32_t f_bsize; /* file system block size */
u_int32_t f_iosize; /* optimal transfer block size */
/* unit is f_bsize */
u_int64_t f_blocks; /* total data blocks in file system */
u_int64_t f_bfree; /* free blocks in fs */
int64_t f_bavail; /* free blocks avail to non-superuser */
u_int64_t f_files; /* total file nodes in file system */
u_int64_t f_ffree; /* free file nodes in fs */
int64_t f_favail; /* free file nodes avail to non-root */
u_int64_t f_syncwrites; /* count of sync writes since mount */
u_int64_t f_syncreads; /* count of sync reads since mount */
u_int64_t f_asyncwrites; /* count of async writes since mount */
u_int64_t f_asyncreads; /* count of async reads since mount */
fsid_t f_fsid; /* file system id */
u_int32_t f_namemax; /* maximum filename length */
uid_t f_owner; /* user that mounted the file system */
u_int64_t f_ctime; /* last mount [-u] time */
char f_fstypename[MFSNAMELEN]; /* fs type name */
char f_mntonname[MNAMELEN]; /* directory on which mounted */
char f_mntfromname[MNAMELEN]; /* mounted file system */
char f_mntfromspec[MNAMELEN]; /* special for mount request */
union mount_info mount_info; /* per-filesystem mount options */
};
The buffer is filled with an array of statfs structures, one for each mounted file system up to the size specified by bufsize.
If buf is
NULL,
getfsstat()
returns just the number of mounted file systems.
Normally flags should be
specified as MNT_WAIT. If
flags is set to MNT_NOWAIT,
getfsstat()
will return the information it has available without requesting an update
from each file system. Thus, some of the information will be out of date,
but getfsstat() will not block waiting for
information from a file system that is unable to respond. If no flags are
provided, MNT_WAIT is assumed.
Note that f_fsid will be empty unless the user is the superuser.
RETURN VALUES
Upon successful completion, the number of statfs structures is returned. Otherwise, -1 is returned and the global variable errno is set to indicate the error.
ERRORS
getfsstat() fails if one or more of the
following are true:
- [
EFAULT] - buf points to an invalid address.
- [
EIO] - An I/O error occurred while reading from or writing to the file system.
SEE ALSO
HISTORY
The getfsstat() function first appeared in
4.3BSD-Reno.