quotactl — manipulate disk quota
#include <sys/types.h> #include <sys/quota.h>
int
quotactl( |
int | cmd, |
| const char * | special, | |
| int | id, | |
| caddr_t | addr); |
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_QUOTAONEnable quota. The addr argument is the
pathname of the file containing the quota for the
filesystem.
Q_QUOTAOFFDisable quota.
Q_GETQUOTAGet limits and current usage of disk space. The
addr argument
is a pointer to a dqblk structure (defined in
<sys/quota.h>
Q_SETQUOTASet limits and current usage; addr is as before.
Q_SETQLIMSet limits; addr is as before.
Q_SETUSESet usage.
Q_SYNCSync disk copy of a filesystem's quota.
Q_GETSTATSGet collected stats.
On success, quotactl()
returns 0. On error, −1 is returned, and errno is set appropriately.
The quota file is not an ordinary file.
Q_QUOTAON was asked,
but quotas were enabled already.
Bad addr
value.
type is
not a known quota type. Or, special could not be
found.
Cannot read or write the quota file.
Too many open files: cannot open quota file.
special
cannot be found in the mount table.
The kernel was compiled without quota support.
special is
not a block special device.
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.
Q_GETQUOTA or
Q_SETQUOTA or
Q_SETUSE or Q_SETQLIM was asked for a file system
that didn't have quota enabled.
This page is part of release 2.79 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/.
|
Copyright (C) 1996 Andries Brouwer (aebcwi.nl) Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Since the Linux kernel and libraries are constantly changing, this manual page may be incorrect or out-of-date. The author(s) assume no responsibility for errors or omissions, or for damages resulting from the use of the information contained herein. The author(s) may not have taken the same level of care in the production of this manual, which is licensed free of charge, as they might when working professionally. Formatted or processed versions of this manual, if unaccompanied by the source, must acknowledge the copyright and authors of this work. FIXME There is much that is missing and/or out of date in this page. As things stand the page more or less documents Linux 2.2 reality: Linux 2.2 has: Q_GETQUOTA Q_GETSTATS Q_QUOTAOFF Q_QUOTAON Q_RSQUASH (not currently documented) Q_SETQLIM Q_SETQUOTA Q_SETUSE Q_SYNC Linux 2.4 has: Q_COMP_QUOTAOFF Q_COMP_QUOTAON Q_COMP_SYNC Q_GETFMT Q_GETINFO Q_GETQUOTA Q_QUOTAOFF Q_QUOTAON Q_SETINFO Q_SETQUOTA Q_SYNC Q_V1_GETQUOTA Q_V1_GETSTATS Q_V1_RSQUASH Q_V1_SETQLIM Q_V1_SETQUOTA Q_V1_SETUSE Q_V2_GETINFO Q_V2_GETQUOTA Q_V2_SETFLAGS Q_V2_SETGRACE Q_V2_SETINFO Q_V2_SETQUOTA Q_V2_SETUSE Q_XGETQSTAT Q_XGETQUOTA Q_XQUOTAOFF Q_XQUOTAON Q_XQUOTARM Q_XSETQLIM Linux 2.6.16 has: Q_GETFMT Q_GETINFO Q_GETQUOTA Q_QUOTAOFF Q_QUOTAON Q_SETINFO Q_SETQUOTA Q_SYNC Q_XGETQSTAT Q_XGETQUOTA Q_XQUOTAOFF Q_XQUOTAON Q_XQUOTARM Q_XQUOTASYNC Q_XSETQLIM |