QUOTACTL(2) BSD System Calls Manual QUOTACTL(2)NAME
quotactl — manipulate file system quotas
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <sys/types.h>
#include <ufs/ufs/quota.h>
int
quotactl(const char *path, int cmd, int id, void *addr);
DESCRIPTION
The quotactl() system call enables, disables and manipulates file system
quotas. A quota control command given by cmd operates on the given file‐
name path for the given user or group id. (NOTE: One should use the QCMD
macro defined in <ufs/ufs/quota.h> to formulate the value for cmd.) The
address of an optional command specific data structure, addr, may be
given; its interpretation is discussed below with each command.
For commands that use the id identifier, it must be either -1 or any pos‐
itive value. The value of -1 indicates that the current UID or GID
should be used. Any other negative value will return an error.
Currently quotas are supported only for the “ufs” file system. For
“ufs”, a command is composed of a primary command (see below) and a com‐
mand type used to interpret the id. Types are supported for interpreta‐
tion of user identifiers (USRQUOTA) and group identifiers (GRPQUOTA).
The “ufs” specific commands are:
Q_QUOTAON Enable disk quotas for the file system specified by path.
The command type specifies the type of the quotas being
enabled. The addr argument specifies a file from which to
take the quotas. The quota file must exist; it is normally
created with the quotacheck(8) program. The id argument is
unused. Only the super-user may turn quotas on.
Q_QUOTAOFF Disable disk quotas for the file system specified by path.
The command type specifies the type of the quotas being
disabled. The addr and id arguments are unused. Only the
super-user may turn quotas off.
Q_GETQUOTA Get disk quota limits and current usage for the user or
group (as determined by the command type) with identifier
id. The addr argument is a pointer to a struct dqblk
structure (defined in <ufs/ufs/quota.h>).
Q_SETQUOTA Set disk quota limits for the user or group (as determined
by the command type) with identifier id. The addr argument
is a pointer to a struct dqblk structure (defined in
<ufs/ufs/quota.h>). The usage fields of the dqblk struc‐
ture are ignored. This system call is restricted to the
super-user.
Q_SETUSE Set disk usage limits for the user or group (as determined
by the command type) with identifier id. The addr argument
is a pointer to a struct dqblk structure (defined in
<ufs/ufs/quota.h>). Only the usage fields are used. This
system call is restricted to the super-user.
Q_SYNC Update the on-disk copy of quota usages. The command type
specifies which type of quotas are to be updated. The id
and addr arguments are ignored.
RETURN VALUES
The quotactl() function returns the value 0 if successful; otherwise the
value -1 is returned and the global variable errno is set to indicate the
error.
ERRORS
The quotactl() system call will fail if:
[EOPNOTSUPP] The kernel has not been compiled with the QUOTA
option.
[EUSERS] The quota table cannot be expanded.
[EINVAL] The cmd argument or the command type is invalid. In
Q_GETQUOTA and Q_SETQUOTA, quotas are not currently
enabled for this file system.
The id argument to Q_GETQUOTA, Q_SETQUOTA or Q_SETUSE
is a negative value.
[EACCES] In Q_QUOTAON, the quota file is not a plain file.
[EACCES] Search permission is denied for a component of a path
prefix.
[ENOTDIR] A component of a path prefix was not a directory.
[ENAMETOOLONG] A component of either pathname exceeded 255 charac‐
ters, or the entire length of either path name
exceeded 1023 characters.
[ENOENT] A filename does not exist.
[ELOOP] Too many symbolic links were encountered in translat‐
ing a pathname.
[EROFS] In Q_QUOTAON, the quota file resides on a read-only
file system.
[EIO] An I/O error occurred while reading from or writing to
a file containing quotas.
[EFAULT] An invalid addr was supplied; the associated structure
could not be copied in or out of the kernel.
[EFAULT] The path argument points outside the process's allo‐
cated address space.
[EPERM] The call was privileged and the caller was not the
super-user.
SEE ALSOquota(1), fstab(5), edquota(8), quotacheck(8), quotaon(8), repquota(8)HISTORY
The quotactl() system call appeared in 4.3BSD-Reno.
BUGS
There should be some way to integrate this call with the resource limit
interface provided by setrlimit(2) and getrlimit(2).
BSD March 5, 1999 BSD
