bionic (2) quotactl.2freebsd.gz

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.

     [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).