QUOTACTL

quotactl ? manipulate disk quotas

#include <linux/quota.h>

int quotactl(cmd, special, uid, addr)
int cmd;
char ?special;
int uid;
caddr_t addr;

The quotactl() call manipulates disk quotas. cmd indicates a command to be applied to UID id or GID id. To set the type of quota use the QCMD(cmd,type) macro. special is a pointer to a null-terminated string containing the path name of the block special device for the file system being manipulated. addr is the address of an optional, command specific, data structure which is copied in or out of the system. The interpretation of addr is given with each command below.

Q_QUOTAON

Turn on quotas for a file system. addr points to the path name of file containing the quotas for the file system. The quota file must exist; it is normally created with the quotacheck(8) program. This call is restricted to the super-user.

Q_QUOTAOFF

Turn off quotas for a file system. addr and uid are ignored. This call is restricted to the super-user.

Q_GETQUOTA

Get disk quota limits and current usage for user or group id. addr is a pointer to a dqblk structure (defined in <linux/quota.h>). Only the super-user may get the quotas of a user other than himself.

Q_SETQUOTA

Set disk quota limits and current usage for user or group id. addr is a pointer to a dqblk structure (defined in <linux/quota.h>). This call is restricted to the super-user.

Q_SETQLIM

Set disk quota limits for user or group id. addr is a pointer to a dqblk structure (defined in <linux/quota.h>). This call is restricted to the super-user.

Q_SYNC

Update the on-disk copy of quota usages for a file system. If special is null then all file systems with active quotas are sync’ed. addr and uid are ignored.

quotactl() returns:

0

on success.

?1

on failure and sets errno to indicate the error.

EFAULT

addr or special are invalid.

EINVAL

The kernel has not been compiled with the QUOTA option.

cmd is invalid.

ENOENT

The file specified by special or addr does not exist.

ENOTBLK

special is not a block device.

EPERM

The call is privileged and the caller was not the super-user.

ESRCH

No disc quota is found for the indicated user.

Quotas have not been turned on for this file system.

EUSERS

The quota table is full.

If cmd is Q_QUOTAON quotactl( may set errno to:

EACCES

The quota file pointed to by addr exists but is not a regular file.

The quota file pointed to by addr exists but is not on the file system pointed to by special.

EBUSY

Q_QUOTAON attempted while another Q_QUOTAON has already taken place.

quota(1), getrlimit(2), quotacheck(8), quotaon(8)