NAME

       quotactl — manipulate file system quotas

LIBRARY

       Standard C Library (libc, -lc)

SYNOPSIS

       #include <sys/types.h>
       #include <ufs/ufs/quota.h>

       int
       quotactl(const char *path, int cmd, int id, void *addr);

DESCRIPTION

       The quotactl() system call enables, disables and manipulates file system quotas.  A quota control command
       given  by  cmd operates on the given filename path for the given user or group id.  (NOTE: One should use
       the QCMD macro defined in <ufs/ufs/quota.h> to formulate the value for cmd.)  The address of an  optional
       command  specific  data  structure,  addr,  may be given; its interpretation is discussed below with each
       command.

       For commands that use the id identifier, it must be either -1 or any positive value.   The  value  of  -1
       indicates that the current UID or GID should be used.  Any other negative value will return an error.

       Currently  quotas  are  supported  only for the “ufs” file system.  For “ufs”, 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  (USRQUOTA)  and  group identifiers (GRPQUOTA).  The “ufs” specific
       commands are:

       Q_QUOTAON        Enable disk quotas for the file system 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 file system 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_GETQUOTASIZE   Get the wordsize used to represent the quotas for the user or group  (as  determined  by
                        the  command  type).  Possible values are 32 for the old-style quota file and 64 for the
                        new-style quota file.  The addr argument is a pointer to an integer into which the  size
                        is stored.  The identifier id is not used.

       Q_GETQUOTA       Get  disk  quota  limits  and  current usage for the user or group (as determined by the
                        command type) with identifier id.  The addr argument 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.  The addr argument is a pointer to a struct dqblk structure  (defined  in
                        <ufs/ufs/quota.h>).   The  usage fields of the dqblk structure are ignored.  This system
                        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.   The addr argument is a pointer to a struct dqblk structure (defined in
                        <ufs/ufs/quota.h>).  Only the usage fields are used.  This system 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 arguments are ignored.

RETURN VALUES

       The quotactl() function returns the value 0 if successful; otherwise the value -1  is  returned  and  the
       global variable errno is set to indicate the error.

ERRORS

       The quotactl() system call will fail if:

       [EOPNOTSUPP]       The kernel has not been compiled with the QUOTA option.

       [EUSERS]           The quota table cannot be expanded.

       [EINVAL]           The  cmd  argument  or  the  command  type is invalid.  In Q_GETQUOTASIZE, Q_GETQUOTA,
                          Q_SETQUOTA, and Q_SETUSE, quotas are not currently enabled for this file system.

                          The id argument to Q_GETQUOTA, Q_SETQUOTA or Q_SETUSE is a negative value.

       [EACCES]           In Q_QUOTAON, the quota file is not a plain file.

       [EACCES]           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 either pathname exceeded 255 characters, or the entire length of either
                          path name exceeded 1023 characters.

       [ENOENT]           A filename does not exist.

       [ELOOP]            Too many symbolic links were encountered in translating a pathname.

       [EROFS]            In Q_QUOTAON, either the file system on which quotas are  to  be  enabled  is  mounted
                          read-only or the quota file resides on a read-only file system.

       [EIO]              An I/O error occurred while reading from or writing to a file containing quotas.

       [EINTEGRITY]       Corrupted data was detected while reading from the file system.

       [EFAULT]           An  invalid  addr was supplied; the associated structure could not be copied in or out
                          of the kernel.

       [EFAULT]           The path argument points outside the process's allocated address space.

       [EPERM]            The call was privileged and the caller was not the super-user.

SEE ALSO

       quota(1), fstab(5), edquota(8), quotacheck(8), quotaon(8), repquota(8)

HISTORY

       The quotactl() system 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).

Debian                                           March 30, 2020                                      QUOTACTL(2)