statvfs(2)

NAME

statvfs, fstatvfs — get file system information

SYNOPSIS

#include <sys/types.h>

#include <sys/statvfs.h>

int statvfs (const char *path, struct statvfs *buf);

int fstatvfs (int fildes, struct statvfs *buf);

DESCRIPTION

statvfs() returns information about a mounted file system.

fstatvfs() returns similar information about an open file.

The parameters for the statvfs() and fstatvfs() functions are as follows:

path: is a pointer to a path name of any file within the mounted file system.
buf: is a pointer to a statvfs structure, which is where the file system status information is stored.
fildes: is a file descriptor for an open file, which is created with the successful completion of an open(), creat(), dup(), fcntl(), or pipe() system call (see open(2), creat(2), dup(2), fcntl(2), or pipe(2)).

The statvfs structure contains the following members:

fsblkcnt_t f_blocks;      /* total blocks of f_frsize on file system */
fsblkcnt_t f_bfree;       /* free blocks */
fsblkcnt_t f_bavail;      /* blocks available to non-superusers or
                             users without the LIMIT privilege */
fsfilcnt_t f_files;       /* total file nodes in file system */
fsfilcnt_t f_ffree;       /* free file nodes in file system */
fsfilcnt_t f_favail;      /* file nodes available to non-superusers
                             or users without the LIMIT privilege */
ulong      f_bsize;       /* preferred file system block size */
ulong      f_frsize;      /* fundamental file system block size */
ulong      f_size;        /* see note below */
ulong      f_fsid;        /* file system ID for file system */
                          /* type; see sysfs(2) */
char       f_basetype[FSTYPSZ];  /* file system type name is */
                                 /* null-terminated */
ulong      f_flag;        /* bit mask of flags */
ulong      f_namemax      /* maximum file name length */
char       f_fstr[32];    /* file system specific string */
time_t     f_time;        /* Last time file system was written */

The field f_size contains the size of file system in f_frsize units. Note that this field is not part of the standard POSIX definition of statvfs. When a 32-bit application uses statvfs64() with a large file system, f_size will top out at MAXINT, rather than return an EOVERFLOW error. Use f_blocks instead.

The field f_basetype contains a null-terminated file-system-type name.

The constant [FSTYPSZ] is defined in the header file <statvfs.h>.

The following flags can be returned in the f_flag field:

ST_LARGEFILES: File system is enabled for large files.
ST_RDONLY: File system is read-only.
ST_NOSUID: File system does not support setuid and setgid semantics.
ST_EXPORTED: File system is exported (NFS).
ST_QUOTA
ST_USRQUOTA: User quotas enabled on this file system.
ST_GRPQUOTA: Group quotas enabled on this file system.

Security Restrictions

The field f_bavail is the number of blocks available to non-superusers or users without the LIMIT privilege. The field f_favail is the number of file nodes available to non-superusers or users without the LIMIT privilege. See privileges(5) for more information about privileged access on systems that support fine-grained privileges.

RETURN VALUE

statvfs() and fstatvfs() return 0 upon successful completion; otherwise, they return -1 and set errno to indicate the error.

ERRORS

If statvfs() fails, errno is set to one of the following values:

EACCES: Search permission is denied for a component of the path prefix.
ELOOP: Too many symbolic links are encountered during path-name translation.
ENAMETOOLONG: The length of the specified path name exceeds PATH_MAX bytes, or the length of a component of the path name exceeds NAME_MAX bytes while _POSIX_NO_TRUNC is in effect.
ENOENT: The named file does not exist (for example, path is null or a component of path does not exist).
ENOTDIR: A component of the path prefix is not a directory.

If fstatvfs() fails, errno is set to the following value:

EBADF: fildes is not a valid open file descriptor.

When both statvfs() and fstatvfs() fail, errno is set to one of the following values:

EFAULT: buf points to an invalid address.
EIO: An I/O error occurred while reading from or writing to the file system.
EOVERFLOW: Result would overflow one or more fields of the statvfs struct.

statvfs(2)

Technical documentation

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