quotactl - Manipulate disk quotas
#include <sys/quota.h>
int quotactl(
char *path,
int cmd,
int id,
char *addr );
Specifies the pathname of any file within the mounted file
system. Specifies a command for interpreting the id
parameter. Specifies the user or group identifier. Specifies
the address of an optional, command-specific data
structure that is copied in or out of the system. The
interpretation of the addr parameter is given with each
command.
The quotactl() function is used to enable and disable quotas
and to manipulate disk quotas for file systems on
which quotas have been enabled.
Quotas are supported for the UNIX file system (UFS) and
the Advanced File System (AdvFS).
A command is composed of a primary command (see below) and
a command type that is used to interpret the id parameter.
Types are supported for interpretation of user identifiers
(type USRQUOTA) and group identifiers (type GRPQUOTA). The
cmd argument is composed from a type and a specific command
with the QCMD macro. For example, to get the quota
limits and usage for a group, the cmd argument would be
formed by:
cmd=QCMD(Q_GETQUOTA, GRPQUOTA);
Note that block sizes are in DEV_BSIZE (that is, 512) byte
blocks.
The specific commands are: Enable disk quotas for the file
system specified by the path parameter. The command type
specifies the type of the quotas being enabled. The addr
parameter specifies a file from which to take the quotas.
The quota file must exist; it is normally created with the
quotacheck program. The id parameter is unused. Only users
with superuser privilege can turn on quotas. Disable disk
quotas for the file system specified by the path parameter.
The command type specifies the type of the quotas
being disabled. The addr and id parameters are unused.
Only users with superuser privilege can turn off quotas.
Get disk quota limits and current usage for the user or
group (as determined by the command type) with identifier
id. The addr parameter points to a dqblk32 structure,
which is defined in the <quota.h> header file. Quotas
must be enabled on the file system for this command to
work. Set disk quota limits for the user or group (as
determined by the command type) with identifier id. The
addr parameter points to a dqblk32 structure, which is
defined in the <quota.h> header file. Quotas must be
enabled on the file system for this command to work. The
usage fields of the dqblk32 structure are ignored. This
function is restricted to processes with superuser privilege.
Set disk usage limits for the user or group (as
determined by the command type) with identifier id. The
addr parameter points to a dqblk32 structure, which is
defined in the <quota.h> header file. Only the usage
fields are used. This function is restricted to processes
with superuser privilege. 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. Returns quota information for the file system,
including flags that specify whether user quotas or group
quotas are enabled and whether large quotas are supported.
The addr parameter points to an int value, and the flags
are defined in the <quota.h> header file. Get disk quota
limits and current usage for the user or group (as determined
by the command type) with identifier id. The addr
parameter points to a dQBlk64 structure, which is defined
in the <quota.h> header file. Set disk quota limits for
the user or group (as determined by the command type) with
identifier id. The addr parameter points to a dQBlk64
structure, which is defined in the <quota.h> header file.
Set disk usage limits for the user or group (as determined
by the command type) with identifier id. The addr parameter
points to a dQBlk64 structure, which is defined in the
<quota.h> header file.
AdvFS file domains created by Tru64 UNIX Version 5.0 or
higher systems can support filesets with increased user
and group quota limits, as the on-disk structure that
holds the limits has increased from 4 bytes to 8 bytes.
However, AdvFS file domains created by Tru64 UNIX systems
earlier than Version 5.0 can only support filesets with
the smaller user and group quota limits. For example, if
you add a fileset to an AdvFS file domain that itself was
created by Digital UNIX Version 4.0, the fileset has the
smaller user and group quota limits.
The root user can exceed user and group quotas.
Upon successful completion, 0 (zero) is returned. Otherwise,
-1 is returned and errno is set to indicate the
error.
If the quotactl() function fails, errno may be set to one
of the following values: Q_QUOTAON: the quota file is not
a plain file.
Search permission is denied for a component of a
path prefix. Q_QUOTAOFF: an attempt has been made
to remove a file during this operation. Q_QUOTAON:
the quota file resides on a read-only file system.
Q_GETQUOTA: one or more of the quota limits being
returned is larger than 2 Tb.
Q_SETQUOTA64 or Q_SETUSE64: an attempt has been
made to set one or more of the quota limits larger
than 4 bytes on a fileset that does not support
larger quota limits. An invalid addr is supplied;
the associated structure could not be copied in or
out of the kernel.
The path parameter points outside the process's
allocated address space. The cmd parameter or the
command type is invalid.
A pathname contains a character with the high-order
bit set.
Q_GETQUOTA or Q_SETQUOTA: the command was attempted
on a file system that did not have quotas enabled.
An I/O error occurred while reading from or writing
to a file containing quotas. Too many symbolic
links were encountered in translating a pathname.
A component of the pathname exceeded NAME_MAX, or
the entire length of the pathname exceeded
PATH_MAX. A file name does not exist. A component
of a path prefix is not a directory. The kernel
has not been compiled with the QUOTA option. The
call is privileged and the caller does not have
appropriate privilege. The quota table cannot be
expanded.
Commands: quota(1), edquota(8), quotacheck(8), quotaon(8),
repquota(8)
quotactl(2)
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