QUOTACTL(2) NetBSD System Calls Manual QUOTACTL(2)
NAME
quotactl -- manipulate file system quotas
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <prop/proplib.h>
#include <sys/quota.h>
int
quotactl(const char *path, struct plistref *pref);
DESCRIPTION
The quotactl() call manipulates file system quotas. A quota control com-
mand described by struct plistref * operates on the given filename path.
The top-level object of the property list sent to the kernel is a dictio-
nary. It holds an integer with key "interface version", which must be 1
at this time. The key "commands" holds an array of dictionaries, each
dictionary describe a command.
A command dictionary has the following keys:
command A string describing the command to execute.
data An array of arguments to the command.
type A string describing the type of quota to address. At this time
this can be either "user" or "group".
The data array is an array of dictionaries, the dictionary structure
depends on the command. If the command takes no arguments, the array
must be present and empty. A dictionary describing a quota entry is com-
mon to many commands arguments or replies. It has the following keys:
block A dictionary describing quota values and limits for block usage.
file A dictionary describing quota values and limits for inode usage.
id either an unsigned integer, or the string "default". If this key
is an integer, the value is the user or group id this quota entry
belongs to. If this key is the string "default", this quota entry
describe the default quotas for this file system.
The block or file dictionaries have the following structures:
usage an unsigned integer which contains the current usage.
soft unsigned integer containing the soft limit. The value
defined by the macro UQUAD_MAX means there is no limit.
hard unsigned integer containing the hard limit. The value
defined by the macro UQUAD_MAX means there is no limit.
grace time integer, the grace delay in seconds which should be applied
when usage goes over the soft limit.
expire time integer, the time (in seconds since epoch) at which the
grace delay expires. This key is only valid when usage is
over the soft limit.
On return the "struct plistref *" contains an updated plist. It has the
same structure as the plist sent to the kernel. The command dictionary
gains an additional key "return", and integer holding an errno which is
the status of the command. The data array is updated with replies from
the command.
Commands are:
get version get the kernel quota version implementation for the speci-
fied file system and type. The data array in the reply has
a single dictionary, which has a single integer key "ver-
sion". At this time version can be "1" (the legacy quota
implementation, with usages and limits stored in an external
file) or "2" (the new quota implementation, where usages and
limits are integrated in the file system metadata).
get Get a quota entry for the specified id. The command argu-
ment is one or more "id" keys. The command reply is the
requested quota entries, as described above.
getall Get all quota entries (kernel quota version 2 only). This
command takes no arguments, the reply is all the existing
quota entries for this file system and type.
set create or update quota limits. Argument is one or more
quota entries holding the updated quota limits. There is no
reply.
clear clear specified quota entries (kernel quota version 2 only).
Each quota entry is either returned to the free list if both
block and file usage is 0, or limits are reverted to the
default values otherwise. The command argument is one or
more "id" keys. There is no reply.
quotaon enable the specified quota type on the specified file system
(kernel quota version 1 only). Argument is a string with
key "quotafile", which contains the path to the external
file holding usages and limits. There is no reply.
quotaoff disable the specified quota type on the specified file sys-
tem (kernel quota version 1 only). There is no arguments
and no replies.
RETURN VALUES
A successful call returns 0, otherwise the value -1 is returned and the
global variable errno indicates the reason for the failure.
FILES
Example of usage of the quotactl syscall, with construction of the pref
argument an interpretation of the reply, can be found in the following
NetBSD source files:
src/usr.bin/quota/getvfsquota.c
src/usr.sbin/repquota/repquota.c
src/usr.sbin/edquota/edquota.c
src/usr.sbin/quotaon/quotaon.c
src/sys/ufs/ufs/quota2_prop.c
ERRORS
A quotactl() call will fail if:
[EFAULT] struct plistref * points outside the process's allo-
cated address space, or an invalid addr was supplied;
the associated structure could not be copied in or out
of the kernel.
[EINVAL] The plist is invalid.
[ENOMEM] Memory could not be allocated to handle the plist.
[EOPNOTSUPP] Either the kernel has not been compiled with the QUOTA
or QUOTA2 options, or the mounted file system doesn't
support quota.
SEE ALSO
quota(1), prop_send_syscall(3), proplib(3), fstab(5), edquota(8),
quotacheck(8), quotactl(8), quotaon(8), repquota(8)
HISTORY
The quotactl() function call appeared in 4.3BSD-Reno.
BUGS
There should be some way to integrate this call with the resource limit
interface provided by setrlimit(2) and getrlimit(2).
NetBSD 5.0 February 11, 2011 NetBSD 5.0
