NAME

quota_open, quota_close, quota_on, quota_off, quota_read, quota_write_limits, quota_write_usage, quota_fsname, quota_qfname, quota_maxid, quota_check_path, quota_convert — Manipulate quotas

LIBRARY

System Utilities Library (libutil, -lutil)

SYNOPSIS

#include <sys/param.h>
#include <sys/mount.h>
#include <ufs/ufs/quota.h>
#include <fcntl.h>
#include <fstab.h>
#include <libutil.h>

struct quotafile *
quota_open(struct fstab *fs, int quotatype, int openflags);

int
quota_close(struct quotafile *qf);

int
quota_on(const struct quotafile *qf);

int
quota_off(const struct quotafile *qf);

int
quota_read(struct quotafile *qf, struct dqblk *dqb, int id);

int
quota_write_limits(struct quotafile *qf, struct dqblk *dqb, int id);

int
quota_write_usage(struct quotafile *qf, struct dqblk *dqb, int id);

const char *
quota_fsname(const struct quotafile *qf);

const char *
quota_qfname(const struct quotafile *qf);

int
quota_maxid(const struct quotafile *qf);

int
quota_check_path(const struct quotafile *qf, const char *path);

int
quota_convert(struct quotafile *qf, int wordsize);

DESCRIPTION

These functions are designed to simplify access to filesystem quotas. If quotas are active on a filesystem, these functions will access them directly from the kernel using the quotactl() system call. If quotas are not active, these functions will access them by reading and writing the quota files directly.

The quota_open() function takes a pointer to an fstab entry corresponding to the filesystem on which quotas are to be accessed. The quotatype field indicates the type of quotas being sought, either USRQUOTA or GRPQUOTA. The openflags are those used by the open() system call, usually either O_RDONLY if the quotas are just to be read, or O_RDWR if the quotas are to be updated. The O_CREAT flag should be specified if a new quota file of the requested type should be created if it does not already exist.

The quota_close() function closes any open file descriptors and frees any storage associated with the filesystem and quota type referenced by qf.

The quota_on() function enables quotas for the filesystem associated with its qf argument which may have been opened with O_RDONLY or O_RDWR. The quota_on() function returns 0 if successful; otherwise the value -1 is returned and the global variable errno is set to indicate the error, see quotactl(2) for the possible errors.

The quota_off() function disables quotas for the filesystem associated with its qf argument which may have been opened with O_RDONLY or O_RDWR. The quota_off() function returns 0 if successful; otherwise the value -1 is returned and the global variable errno is set to indicate the error, see quotactl(2) for the possible errors.

The quota_read() function reads the quota from the filesystem and quota type referenced by qf for the user (or group) specified by id into the dqblk quota structure pointed to by dqb.

The quota_write_limits() function updates the limit fields (but not the usage fields) for the filesystem and quota type referenced by qf for the user (or group) specified by id from the dqblk quota structure pointed to by dqb.

The quota_write_usage() function updates the usage fields (but not the limit fields) for the filesystem and quota type referenced by qf for the user (or group) specified by id from the dqblk quota structure pointed to by dqb.

The quota_fsname() function returns a pointer to a buffer containing the path to the root of the file system that corresponds to its qf argument, as listed in /etc/fstab. Note that this may be a symbolic link to the actual directory.

The quota_qfname() function returns a pointer to a buffer containing the name of the quota file that corresponds to its qf argument. Note that this may be a symbolic link to the actual file.

The quota_maxid() function returns the maximum user (or group) id contained in the quota file associated with its qf argument.

The quota_check_path() function checks if the specified path is within the filesystem that corresponds to its qf argument. If the path argument refers to a symbolic link, quota_check_path() will follow it.

The quota_convert() function converts the quota file associated with its qf argument to the data size specified by its wordsize argument. The supported wordsize arguments are 32 for the old 32-bit quota file format and 64 for the new 64-bit quota file format. The quota_convert() function may only be called to operate on quota files that are not currently active.

IMPLEMENTATION NOTES

If the underlying quota file is in or converted to the old 32-bit format, limit and usage values written to the quota file will be clipped to 32 bits.

RETURN VALUES

If the filesystem has quotas associated with it, quota_open() returns a pointer to a quotafile structure used in subsequent quota access calls. If the filesystem has no quotas, or access permission is denied NULL is returned and errno is set to indicate the error.

The quota_check_path() function returns 1 for a positive result and 0 for a negative result. If an error occurs, it returns -1 and sets errno to indicate the error.

The quota_read(), quota_write_limits(), quota_write_usage(), quota_convert(), and quota_close() functions return zero on success. On error they return -1 and set errno to indicate the error.

HISTORY

The quotafile functions first appeared in FreeBSD 8.1.

AUTHORS

The quotafile functions and this manual page were written by Dag-Erling Smørgrav <des@FreeBSD.org> and Marshall Kirk McKusick <mckusick@mckusick.com>.