quotactl(2) System Calls Manual quotactl(2)
NAME
quotactl - Manipulates disk quotas
SYNOPSIS
#include <sys/quota.h>
quotactl( char *path, int cmd, int id, char *addr );
PARAMETERS
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.
DESCRIPTION
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 struct dqblk32 structure, 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 struct dqblk32 structure, 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 com-
mand type) with identifier id. The addr parameter points to a struct dqblk32 structure, 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 and the flags are defined in the <quota.h> header file. Get disk quota limits and curent usage for the user or
group (as determined by the command type) with identifier id. The addr parameter points to a structure, dQBlk64, as 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 structure, dQBlk64, as defined in the <quota.h> header file. Set disk usage limits for the user or group (as deter-
mined by the command type) with identifier id. The addr parameter points to a structure, dQBlk64, as defined in the <quota.h> header file.
NOTES
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 DIGITAL UNIX
systems and Tru64 UNIX systems earlier than Version 5.0 can only support filesets with the smaller user and group quota limits. For exam-
ple, 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.
RETURN VALUES
Upon successful completion, 0 (zero) is returned. Otherwise, -1 is returned and errno is set to indicate the error.
ERRORS
If the quotactl() function fails, errno may be set to one of the following values: The kernel has not been compiled with the QUOTA option.
The quota table cannot be expanded. 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. Q_QUOTAON: the quota file
is not a plain file.
Search permission is denied for a component of a path prefix. A component of a path prefix is not a directory. A component of the
pathname exceeded NAME_MAX, or the entire length of the pathname exceeded PATH_MAX. A filename does not exist. Too many symbolic
links were encountered in translating a pathname. Q_QUOTAON: the quota file resides on a read-only file system. An I/O error
occurred while reading from or writing to a file containing quotas. 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 call is privileged and the caller does not have appro-
priate privilege. Q_QUOTAOFF: an attempt has been made to remove a file during this operation. 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.
RELATED INFORMATION
Commands: quota(1), edquota(8), quotacheck(8), quotaon(8), repquota(8) delim off
quotactl(2)