QUOTACTL(2)

NAME
quotactl - manipulate disk quota

SYNOPSIS
#include <sys/types.h>
#include <sys/quota.h>

int quotactl(int cmd, const char *special, int id, caddr_t addr);

DESCRIPTION
The quota system defines for each user and/or group a soft limit and a hard limit bounding the amount of disk space that can be used on a given file system. The hard limit cannot be crossed. The soft limit can be crossed, but warnings will ensue. Moreover, the user cannot be above the soft limit for more than one week (by default) at a time: after this week the soft limit counts as hard limit.

The quotactl() system call manipulates these quota. Its first argument is of the form QCMD(subcmd,type) where type is either USRQUOTA or GRPQUOTA (for user quota and group quota, respectively), and subcmd is described below.

The second argument special is the block special device these quota apply to. It must be mounted.

The third argument id is the user or group ID these quota apply to (when relevant).

The fourth argument addr is the address of a data structure, depending on the command.

The subcmd is one of

Q_QUOTAON
    Enable quota. The addr argument is the pathname of the file containing the quota for the filesystem.

Q_QUOTAOFF
    Disable quota.

Q_GETQUOTA
    Get limits and current usage of disk space. The addr argument is a pointer to a dqblk structure (defined in <sys/quota.h>).

Q_SETQUOTA
    Set limits and current usage; addr is as before.

Q_SETQLIM
    Set limits; addr is as before.

Q_SETUSE
    Set usage.

Q_SYNC
    Sync disk copy of a filesystem's quota.

Q_GETSTATS
    Get collected stats.

RETURN VALUE
On success, quotactl() returns 0. On error, -1 is returned, and errno is set appropriately.

ERRORS

EACCES
    The quota file is not an ordinary file.

EBUSY
    Q_QUOTAON was asked, but quotas were enabled already.

EFAULT
    Bad addr value.

EINVAL
    type is not a known quota type. Or, special could not be found.

EIO Cannot read or write the quota file.

EMFILE
    Too many open files: cannot open quota file.

ENODEV
    special cannot be found in the mount table.

ENOPKG
    The kernel was compiled without quota support.

ENOTBLK
    special is not a block special device.

EPERM
    The process was not root (for the file system), and Q_GETQUOTA was asked for another id than that of the process itself, or anything other than Q_GETSTATS or Q_SYNC was asked.

ESRCH
    Q_GETQUOTA or Q_SETQUOTA or Q_SETUSE or Q_SETQLIM was asked for a file system that didn't have quota enabled.

CONFORMING TO
BSD

SEE ALSO
quota(1), getrlimit(2), setrlimit(2), ulimit(3), quotacheck(8), quotaon(8)

COLOPHON
This page is part of release 2.76 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.