quotactl - manipulate filesystem quotas
Standard C Library (libc, -lc)
#include <ufs/ufs/quota.h> /* for ufs quotas */
int
quotactl(const char *path, int cmd, int id, void *addr);
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 ``lfs'' filesystem.
For both of them, 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
``ffs'' and ``lfs'' 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 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. addr
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. addr is a pointer to a
struct dqblk structure (defined in <ufs/ufs/quota.h>). 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 (defined in <ufs/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 which type of quotas are to be updated. The id and
addr parameters are ignored.
A successful call returns 0, otherwise the value -1 is returned and the
global variable errno indicates the reason for the failure.
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, or
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} characters,
or an entire path name exceeded {PATH_MAX} 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] path points outside the process's allocated address
space, or an invalid addr was supplied; the associated
structure could not be copied in or out of the kernel.
[EPERM] The call was privileged and the caller was not the
super-user.
quota(1), fstab(5), edquota(8), quotacheck(8), quotaon(8), repquota(8)
The quotactl() function call appeared in 4.3BSD-Reno.
There should be some way to integrate this call with the resource limit
interface provided by setrlimit(2) and getrlimit(2).
BSD March 10, 1995 BSD
[ Back ] |