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.\"	@(#)quotactl.2	8.2 (Berkeley) 3/10/95
.\" $FreeBSD: release/9.1.0/lib/libc/sys/quotactl.2 237216 2012-06-18 04:55:07Z eadler $
.\"
.Dd March 5, 1999
.Dt QUOTACTL 2
.Os
.Sh NAME
.Nm quotactl
.Nd manipulate file system quotas
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In sys/types.h
.In ufs/ufs/quota.h
.Ft int
.Fn quotactl "const char *path" "int cmd" "int id" "void *addr"
.Sh DESCRIPTION
The
.Fn quotactl
system call enables, disables and
manipulates file system quotas.
A quota control command
given by
.Fa cmd
operates on the given filename
.Fa path
for the given user or group
.Fa id .
(NOTE: One should use the QCMD macro defined in
.In ufs/ufs/quota.h
to formulate the value for
.Fa cmd . )
The address of an optional command specific data structure,
.Fa addr ,
may be given; its interpretation
is discussed below with each command.
.Pp
For commands that use the
.Fa id
identifier, it must be either -1 or any positive value.
The value of -1 indicates that the current UID or GID should be used.
Any other negative value will return an error.
.Pp
Currently quotas are supported only for the
.Dq ufs
file system.
For
.Dq ufs ,
a command is composed of a primary command (see below)
and a command type used to interpret the
.Fa id .
Types are supported for interpretation of user identifiers (USRQUOTA)
and group identifiers (GRPQUOTA).
The
.Dq ufs
specific commands are:
.Bl -tag -width Q_GETQUOTASIZEx
.It Dv Q_QUOTAON
Enable disk quotas for the file system specified by
.Fa path .
The command type specifies the type of the quotas being enabled.
The
.Fa addr
argument specifies a file from which to take the quotas.
The quota file must exist;
it is normally created with the
.Xr quotacheck 8
program.
The
.Fa id
argument is unused.
Only the super-user may turn quotas on.
.It Dv Q_QUOTAOFF
Disable disk quotas for the file system specified by
.Fa path .
The command type specifies the type of the quotas being disabled.
The
.Fa addr
and
.Fa id
arguments are unused.
Only the super-user may turn quotas off.
.It Dv Q_GETQUOTASIZE
Get the wordsize used to represent the quotas for the user or group
(as determined by the command type).
Possible values are 32 for the old-style quota file
and 64 for the new-style quota file.
The
.Fa addr
argument is a pointer to an integer into which the size is stored.
The identifier
.Fa id
is not used.
.It Dv Q_GETQUOTA
Get disk quota limits and current usage for the user or group
(as determined by the command type) with identifier
.Fa id .
The
.Fa addr
argument
is a pointer to a
.Fa struct dqblk
structure (defined in
.In ufs/ufs/quota.h ) .
.It Dv Q_SETQUOTA
Set disk quota limits for the user or group
(as determined by the command type) with identifier
.Fa id .
The
.Fa addr
argument
is a pointer to a
.Fa struct dqblk
structure (defined in
.In ufs/ufs/quota.h ) .
The usage fields of the
.Fa dqblk
structure are ignored.
This system call is restricted to the super-user.
.It Dv Q_SETUSE
Set disk usage limits for the user or group
(as determined by the command type) with identifier
.Fa id .
The
.Fa addr
argument
is a pointer to a
.Fa struct dqblk
structure (defined in
.In ufs/ufs/quota.h ) .
Only the usage fields are used.
This system call is restricted to the super-user.
.It Dv Q_SYNC
Update the on-disk copy of quota usages.
The command type specifies which type of quotas are to be updated.
The
.Fa id
and
.Fa addr
arguments are ignored.
.El
.Sh RETURN VALUES
.Rv -std quotactl
.Sh ERRORS
The
.Fn quotactl
system call will fail if:
.Bl -tag -width Er
.It Bq Er EOPNOTSUPP
The kernel has not been compiled with the
.Dv QUOTA
option.
.It Bq Er EUSERS
The quota table cannot be expanded.
.It Bq Er EINVAL
The
.Fa cmd
argument
or the command type is invalid.
In
.Dv Q_GETQUOTASIZE ,
.Dv Q_GETQUOTA ,
.Dv Q_SETQUOTA ,
and
.Dv Q_SETUSE ,
quotas are not currently enabled for this file system.
.Pp
The
.Fa id
argument to
.Dv Q_GETQUOTA ,
.Dv Q_SETQUOTA
or
.Dv Q_SETUSE
is a negative value.
.It Bq Er EACCES
In
.Dv Q_QUOTAON ,
the quota file is not a plain file.
.It Bq Er EACCES
Search permission is denied for a component of a path prefix.
.It Bq Er ENOTDIR
A component of a path prefix was not a directory.
.It Bq Er ENAMETOOLONG
A component of either pathname exceeded 255 characters,
or the entire length of either path name exceeded 1023 characters.
.It Bq Er ENOENT
A filename does not exist.
.It Bq Er ELOOP
Too many symbolic links were encountered in translating a pathname.
.It Bq Er EROFS
In
.Dv Q_QUOTAON ,
either the file system on which quotas are to be enabled is mounted read-only
or the quota file resides on a read-only file system.
.It Bq Er EIO
An
.Tn I/O
error occurred while reading from or writing
to a file containing quotas.
.It Bq Er EFAULT
An invalid
.Fa addr
was supplied; the associated structure could not be copied in or out
of the kernel.
.It Bq Er EFAULT
The
.Fa path
argument
points outside the process's allocated address space.
.It Bq Er EPERM
The call was privileged and the caller was not the super-user.
.El
.Sh SEE ALSO
.Xr quota 1 ,
.Xr fstab 5 ,
.Xr edquota 8 ,
.Xr quotacheck 8 ,
.Xr quotaon 8 ,
.Xr repquota 8
.Sh HISTORY
The
.Fn quotactl
system call appeared in
.Bx 4.3 Reno .
.Sh BUGS
There should be some way to integrate this call with the resource
limit interface provided by
.Xr setrlimit 2
and
.Xr getrlimit 2 .