QUOTACTL(2) BSD Programmer's Manual QUOTACTL(2)NAME
quotactl - manipulate filesystem quotas
SYNOPSIS
#include <ufs/ufs/quota.h>
int
quotactl(const char *path, int cmd, unsigned int id, void *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 or group id. The address of an optional command spe-
cific data structure, addr, may be specified; its interpretation is de-
scribed below with each command.
Currently quotas are supported only for the ``ufs'' filesystem. For
``ufs'', a command is built from a control command (see below) and a com-
mand type, or'ing them together using the macro QCMD defined in the
<ufs/ufs/quota.h> include file.
The two command types are:
GRPQUOTA The control command is in reference to group quotas, and the
id, if specified, is a group identifier.
USRQUOTA The control command is in reference to user quotas, and the
id, if specified, is a user identifier.
The control commands are:
Q_QUOTAON Enable disk quotas for the filesystem specified by path. The
command type specifies whether user or group quotas are being
enabled. The addr argument is a pointer to the pathname of a
file from which to take the quotas. The quota file must ex-
ist; it is normally created with the quotacheck(8) program.
The id argument is unused. Only the super-user may turn quo-
tas on.
Q_QUOTAOFF
Disable disk quotas for the filesystem specified by path. The
command type specifies whether user or group quotas are being
disabled. The addr and id arguments are unused. Only the su-
per-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 (defined in
<ufs/quota.h>).
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 (defined in <ufs/quota.h>). The usage
fields of the dqblk structure are ignored. This call is re-
stricted 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 (defined in <ufs/quota.h>). 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 whether user or group quotas are being updated. The
id and addr parameters are ignored.
EXAMPLES
To update the on-disk copy of the group quotas:
quotactl(filesystem_path, QCMD(Q_SYNC, GRPQUOTA), 0, NULL);
To set the disk usage limits for a specific user:
uid_t user_id;
struct dqblk dqbuf;
quotactl(filesystem_path,
QCMD(Q_SETUSE, USRQUOTA), (unsigned int)user_id, &dqbuf);
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.
[EINVAL] A pathname contains a character with the high-order bit
set.
[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 characters,
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 translating 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), repquo-
ta(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.
BSDI BSD/OS March 10, 1995 3