.TH QUOTACTL 2
.SH NAME
quotactl \- manipulate disk quotas
.SH SYNOPSIS
.nf
.B #include <sys/quota.h>
.B #include <sys/types.h>
.B #include <xfs/xqm.h>
.LP
.B long quotactl(int cmd, char \(**special, int id, caddr_t addr)
.fi
.SH DESCRIPTION
.LP
.IX  "filesystem"  "quotactl() disk quotas"  ""  "\fLquotactl()\fP \(em disk quotas"
.IX  "quotactl() disk quotas"  ""  "\fLquotactl()\fP \(em disk quotas"
.IX  "disk quotas quotactl()"  ""  "disk quotas \(em \fLquotactl()\fP"
.LP
The
.B quotactl(\|)
call manipulates disk quotas.
.I cmd
indicates a command to be applied to 
.SM UID
.IR id
or 
.SM GID
.IR id .
To set the type of quota use the
.IR "QCMD(cmd, type)"
macro.
.I special
is a pointer to a null-terminated string containing the path
name of the block special device for the filesystem being manipulated.
.I addr
is the address of an optional, command specific, data structure
which is copied in or out of the system.  The interpretation of
.I addr
is given with each command below.
.TP 15
.SB Q_QUOTAON
Turn on quotas for a filesystem.
.I id
is the identification number of the quota format to be used. Format numbers
are defined in the header file of appropriate format. Currently there are
two supported quota formats whose numbers are defined by constants
.IR QFMT_VFS_OLD
(original quota format) and
.IR QFMT_VFS_V0
(new VFS v0 quota format).
.IR addr
points to the path name of file containing the quotas for the filesystem.
The quota file must exist; it is normally created with the
.BR quotacheck (8)
program.  This call is restricted to the super-user.
.TP
.SB Q_QUOTAOFF
Turn off quotas for a filesystem.
.I addr
and
.I id
are ignored.
This call is restricted to the super-user.
.TP
.SB Q_GETQUOTA
Get disk quota limits and current usage for user or group
.IR id .
.I addr
is a pointer to an
.B dqblk
structure (defined in
.BR <sys/quota.h> ).
The field
.I dqb_valid
defines the entries in the structure which are set correctly. On
.B Q_GETQUOTA
call all entries are valid. Only the super-user may get the quotas
of a user other than himself.
.TP
.SB Q_SETQUOTA
Set current quota information for user or group
.IR id .
.I addr
is a pointer to an
.B dqblk
structure (defined in
.BR <sys/quota.h> ).
The field
.I dqb_valid
defines which entries in the quota structure are valid and should be set. The constants for
.I dqb_valid
field are defined in the
.B <sys/quota.h>
header file. This call obsoletes calls
.B Q_SETQLIM
and
.B Q_SETUSE
in the previous quota interfaces. This call is restricted to the super-user.
.TP
.SB Q_GETINFO
Get information (like grace times) about quotafile.
.I addr
should be a pointer to an
.B dqinfo
structure (defined in
.IR <sys/quota.h> ).
The
.I dqi_valid
field in the structure defines entries in it
which are valid. On
.B Q_GETINFO
call all entries are valid.
Parameter
.I id
is ignored. 
.TP
.SB Q_SETINFO
Set information about quotafile.
.I addr
should be a pointer to
.B dqinfo
structure (defined in
.IR <sys/quota.h> ).
The field
.I dqi_valid
defines which entries in the quota info structure are valid and should be set. The constants for
.I dqi_valid
field are defined in the
.B <sys/quota.h>
header file. This call obsoletes calls
.B Q_SETGRACE
and
.B Q_SETFLAGS
in the previous quota interfaces. Parameter
.I id
is ignored. This operation is restricted to super-user.
.TP
.SB Q_GETFMT
Get quota format used on the specified filesystem.
.I addr
should be a pointer to a memory (4 bytes) where the format number will be stored.
.TP
.SB Q_SYNC
Update the on-disk copy of quota usages for a filesystem.
If
.I special
is null then all filesystems with active quotas are sync'ed.
.I addr
and
.I id
are ignored.
.TP
.SB Q_GETSTATS
Get statistics and other generic information about quota subsystem.
.I addr
should be a pointer to
.B dqstats
structure (defined in
.BR <sys/quota.h> )
in which data should be stored.
.I special
and
.I id
are ignored.
.TP
For XFS filesystems making use of the XFS Quota Manager (XQM), the above commands are bypassed and the following commands are used:
.TP 15
.SB Q_XQUOTAON
Turn on quotas for an XFS filesystem.
XFS provides the ability to turn on/off quota limit enforcement
with quota accounting.
Therefore, XFS expects the addr to be a pointer to an unsigned int
that contains either the flags XFS_QUOTA_UDQ_ACCT and/or
XFS_QUOTA_UDQ_ENFD (for user quota), or XFS_QUOTA_GDQ_ACCT and/or
XFS_QUOTA_GDQ_ENFD (for group quota), as defined in
.BR <xfs/xqm.h> .
This call is restricted to the superuser.
.TP
.SB Q_XQUOTAOFF
Turn off quotas for an XFS filesystem.
As in Q_QUOTAON, XFS filesystems expect a pointer to an unsigned int
that specifies whether quota accounting and/or limit enforcement need
to be turned off.
This call is restricted to the superuser.
.TP
.SB Q_XGETQUOTA
Get disk quota limits and current usage for user
.IR id .
.I addr
is a pointer to a
.B fs_disk_quota
structure (defined in
.BR <xfs/xqm.h> ).
Only the superuser may get the quotas of a user other than himself.
.TP
.SB Q_XSETQLIM
Set disk quota limits for user
.IR id .
.I addr
is a pointer to a
.B fs_disk_quota
structure (defined in
.BR <xfs/xqm.h> ).
This call is restricted to the superuser.
.TP
.SB Q_XGETQSTAT
Returns a
.B fs_quota_stat
structure containing XFS filesystem specific quota information.
This is useful in finding out how much space is spent to store quota
information, and also to get quotaon/off status of a given local XFS
filesystem.
.TP
.SB Q_XQUOTARM
Free the disk space taken by disk quotas.
Quotas must have already been turned off.
.PP
There is no command equivalent to
.B Q_SYNC
for XFS since
.IR sync (1)
writes quota information to disk (in addition to the other filesystem
metadata it writes out).
.SH RETURN VALUES
.LP
.B quotactl(\|)
returns:
.TP
0
on success.
.TP
\-1
on failure and sets
.B errno
to indicate the error.
.SH ERRORS
.TP 15
.SM EFAULT
.I addr
or
.I special
are invalid.
.TP
.SM ENOSYS
The kernel has not been compiled with the
.SB QUOTA
option.
.TP
.SM EINVAL
.IP
.I cmd
or
.I type
is invalid.
.TP
.SM ENOENT
The file specified by
.I special
or
.I addr
does not exist.
.TP
.SM ENOTBLK
.I special
is not a block device.
.TP
.SM EPERM
The call is privileged and the caller was not the super-user.
.TP
.SM ESRCH
No disc quota is found for the indicated user.
.IP
Quotas have not been turned on for this filesystem.
.LP
If
.I cmd
is
.BR \s-1Q_QUOTAON\s0 ,
.B quotactl(\|)
may set errno to:
.TP 15
.SM EACCES
The quota file pointed to by
.I addr
exists but is not a regular file.
.IP
The quota file pointed to by
.I addr
exists but is not on the
filesystem pointed to by
.IR special .
.TP
.SM EINVAL
The quota file is corrupted.
.TP
.SM ESRCH
Specified quota format was not found.
.TP
.SM EBUSY
.SB Q_QUOTAON
attempted while another
.SB Q_QUOTAON
has already taken place.
.SH "SEE ALSO"
.BR quota (1),
.BR getrlimit (2),
.BR quotacheck (8),
.BR quotaon (8)
