Copyright (c) 2009 Dag-Erling Co��dan Sm��rgrav and
Marshall Kirk McKusick. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
SUCH DAMAGE.
$FreeBSD: releng/10.0/lib/libutil/quotafile.3 233648 2012-03-29 05:02:12Z eadler $
.Dd December 28, 2009 .Dt QUOTAFILE 3 .Os .Sh NAME .Nm quota_open .Nm quota_close .Nm quota_on .Nm quota_off .Nm quota_read .Nm quota_write_limits .Nm quota_write_usage .Nm quota_fsname .Nm quota_qfname .Nm quota_maxid .Nm quota_check_path .Nm quota_convert .Nd "Manipulate quotas" .Sh LIBRARY .Lb libutil .Sh SYNOPSIS n sys/param.h n sys/mount.h n ufs/ufs/quota.h n fcntl.h n fstab.h n libutil.h .Ft "struct quotafile *" .Fn quota_open "struct fstab *fs" "int quotatype" "int openflags" .Ft int .Fn quota_close "struct quotafile *qf" .Ft int .Fn quota_on "const struct quotafile *qf" .Ft int .Fn quota_off "const struct quotafile *qf" .Ft int .Fn quota_read "struct quotafile *qf" "struct dqblk *dqb" "int id" .Ft int .Fn quota_write_limits "struct quotafile *qf" "struct dqblk *dqb" "int id" .Ft int .Fn quota_write_usage "struct quotafile *qf" "struct dqblk *dqb" "int id" .Ft "const char *" .Fn quota_fsname "const struct quotafile *qf" .Ft "const char *" .Fn quota_qfname "const struct quotafile *qf" .Ft int .Fn quota_maxid "const struct quotafile *qf" .Ft int .Fn quota_check_path "const struct quotafile *qf" "const char *path" .Ft int .Fn quota_convert "struct quotafile *qf" "int wordsize" .Sh 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 .Fn quotactl system call. If quotas are not active, these functions will access them by reading and writing the quota files directly.
p The .Fn quota_open function takes a pointer to an .Vt fstab entry corresponding to the filesystem on which quotas are to be accessed. The .Va quotatype field indicates the type of quotas being sought, either .Dv USRQUOTA or .Dv GRPQUOTA . The .Va openflags are those used by the .Fn open system call, usually either .Dv O_RDONLY if the quotas are just to be read, or .Dv O_RDWR if the quotas are to be updated. The .Dv O_CREAT flag should be specified if a new quota file of the requested type should be created if it does not already exist.
p The .Fn quota_close function closes any open file descriptors and frees any storage associated with the filesystem and quota type referenced by .Va qf .
p The .Fn quota_on function enables quotas for the filesystem associated with its .Va qf argument which may have been opened with .Dv O_RDONLY or .Dv O_RDWR . The .Fn quota_on function returns 0 if successful; otherwise the value\~-1 is returned and the global variable .Va errno is set to indicate the error, see .Xr quotactl 2 for the possible errors.
p The .Fn quota_off function disables quotas for the filesystem associated with its .Va qf argument which may have been opened with .Dv O_RDONLY or .Dv O_RDWR . The .Fn quota_off function returns 0 if successful; otherwise the value\~-1 is returned and the global variable .Va errno is set to indicate the error, see .Xr quotactl 2 for the possible errors.
p The .Fn quota_read function reads the quota from the filesystem and quota type referenced by .Va qf for the user (or group) specified by .Va id into the .Vt dqblk quota structure pointed to by .Va dqb .
p The .Fn quota_write_limits function updates the limit fields (but not the usage fields) for the filesystem and quota type referenced by .Va qf for the user (or group) specified by .Va id from the .Vt dqblk quota structure pointed to by .Va dqb .
p The .Fn quota_write_usage function updates the usage fields (but not the limit fields) for the filesystem and quota type referenced by .Va qf for the user (or group) specified by .Va id from the .Vt dqblk quota structure pointed to by .Va dqb .
p The .Fn quota_fsname function returns a pointer to a buffer containing the path to the root of the file system that corresponds to its .Va qf argument, as listed in
a /etc/fstab . Note that this may be a symbolic link to the actual directory.
p The .Fn quota_qfname function returns a pointer to a buffer containing the name of the quota file that corresponds to its .Va qf argument. Note that this may be a symbolic link to the actual file.
p The .Fn quota_maxid function returns the maximum user (or group) .Va id contained in the quota file associated with its .Va qf argument.
p The .Fn quota_check_path function checks if the specified path is within the filesystem that corresponds to its .Va qf argument. If the .Va path argument refers to a symbolic link, .Fn quota_check_path will follow it.
p The .Fn quota_convert function converts the quota file associated with its .Va qf argument to the data size specified by its .Va 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 .Fn quota_convert function may only be called to operate on quota files that are not currently active. .Sh 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. .Sh RETURN VALUES If the filesystem has quotas associated with it, .Fn quota_open returns a pointer to a .Vt quotafile structure used in subsequent quota access calls. If the filesystem has no quotas, or access permission is denied .Dv NULL is returned and .Va errno is set to indicate the error.
p The .Fn 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 .Va errno to indicate the error.
p The .Fn quota_read , .Fn quota_write_limits , .Fn quota_write_usage , .Fn quota_convert , and .Fn quota_close functions return zero on success. On error they return\~-1 and set .Va errno to indicate the error. .Sh SEE ALSO .Xr quotactl 2 , .Xr quota.user 5 , .Xr quota.group 5 .Sh HISTORY The .Nm quotafile functions first appeared in .Fx 8.1 . .Sh AUTHORS .An -nosplit The .Nm quotafile functions and this manual page were written by .An Dag-Erling Sm\(/orgrav Aq des@FreeBSD.org and .An Marshall Kirk McKusick Aq mckusick@mckusick.com .