GETFSSTAT

Section: System Calls (2)
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BSD mandoc
 

NAME

getfsstat - get list of all mounted file systems  

SYNOPSIS

Fd #include <sys/param.h> Fd #include <sys/ucred.h> Fd #include <sys/mount.h> Ft int Fn getfsstat struct statfs *buf long bufsize int flags  

DESCRIPTION

Fn Getfsstat returns information about all mounted file systems. Fa Buf is a pointer to statfs structures defined as follows:
typedef struct { int32_t val[2]; } fsid_t;

#define MFSNAMELEN   16 /* length of fs type name, including nul */
#define MNAMELEN     32 /* length of buffer for returned name */

struct statfs {
    short   f_type;     /* type of file system (unused; zero) */
    short   f_flags;    /* copy of mount flags */
    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 */
    long    f_spare[4]; /* spare for later */
    char    f_fstypename[MFSNAMELEN]; /* fs type name */
    char    f_mntonname[MNAMELEN];    /* directory on which mounted */
    char    f_mntfromname[MNAMELEN];  /* mounted file system */
};

Fields that are undefined for a particular file system are set to -1. The buffer is filled with an array of Fa statfs structures, one for each mounted file system up to the size specified by Fa bufsize .

If Fa buf is given as NULL, Fn getfsstat returns just the number of mounted file systems.

Normally Fa flags should be specified as MNT_WAIT If Fa flags is set to MNT_NOWAIT Fn 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 Thus, some of the information will be out of date, but Fn getfsstat will not block waiting for information from a file system that is unable to respond.  

RETURN VALUES

Upon successful completion, the number of Fa statfs structures is returned. Otherwise, -1 is returned and the global variable errno is set to indicate the error.  

ERRORS

Fn Getfsstat fails if one or more of the following are true:

Bq Er EFAULT
Fa Buf points to an invalid address.
Bq Er EIO
An I/O error occurred while reading from or writing to the file system.

 

SEE ALSO

statfs(2), fstab(5), mount(8)  

HISTORY

The Fn getfsstat function first appeared in 4.4BSD.


 

Index

NAME
SYNOPSIS
DESCRIPTION
RETURN VALUES
ERRORS
SEE ALSO
HISTORY

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Time: 16:29:00 GMT, April 18, 2022