QUOTACTL(2) BSD System Calls Manual QUOTACTL(2)NAMEquotactl — manipulate filesystem quotas
SYNOPSIS
#include <sys/quota.h> /* for disk quotas */
int
quotactl(const char *path, int cmd, int id, char *addr);
DESCRIPTION
The quotactl() call enables, disables and manipulates filesystem quotas.
A quota control command given by cmd operates on the given filename path
for the given user id. The address of an optional command specific data
structure, addr, may be given; its interpretation is discussed below with
each command.
Currently quotas are supported only for the "ffs" and "hfs" filesystems.
A command is composed of a primary command (see below) and a command type
used to interpret the id. Types are supported for interpretation of user
identifiers and group identifiers. The specific commands are:
Q_QUOTAON Enable disk quotas for the filesystem 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 filesystem specified by path.
The command type specifies the type of the quotas being dis‐
abled. 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. Addr is a pointer to a struct dqblk structure.
Q_SETQUOTA Set disk quota limits for the user or group (as determined
by the command type) with identifier id. Addr is a pointer
to a struct dqblk structure. The usage fields of the dqblk
structure are ignored. This 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. Addr is a pointer
to a struct dqblk structure. Only the usage fields are
used. This 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 parameters are ignored.
Q_QUOTASTAT Get the enable status for the filesystem specified by path.
The command type specifies the type of the quotas whose sta‐
tus is being queried. Addr is a pointer to an integer.
Upon return, this integer will hold a zero value if quotas
for the given type are not enabled and a non-zero value if
quotas for the given type are enabled. The id parameter is
ignored.
RETURN VALUES
A successful call returns 0, otherwise the value -1 is returned and the
global variable errno indicates the reason for the failure.
ERRORS
A quotactl() call will fail if:
[EOPNOTSUPP] The kernel has not been compiled with the QUOTA
option.
[EUSERS] The quota table cannot be expanded.
[EINVAL] Cmd or the command type is invalid.
[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 a pathname exceeded {NAME_MAX} charac‐
ters, or an entire path name exceeded {PATH_MAX} char‐
acters.
[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
filesystem.
[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] Path points outside the process's allocated 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)BUGS
There should be some way to integrate this call with the resource limit
interface provided by setrlimit(2) and getrlimit(2).
HISTORY
The quotactl() function call appeared in 4.3BSD-Reno.
BSD June 4, 1993 BSD
