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From: sms@moe.2bsd.com (Steven M. Schultz)
Subject: noaccesstime option added to mount(8) (#379)
Organization: 2BSD, Simi Valley CA USA
Message-ID: <ED1A2z.41y@moe.2bsd.com>
Date: Wed, 9 Jul 1997 04:06:35 GMT
Lines: 451
Xref: euryale.cc.adfa.oz.au comp.bugs.2bsd:816
Subject: noaccesstime option added to mount(8) (#379)
Index: sys/sys_inode,ufs_mount,ufs_fio.c,sbin/mount/mount.c 2.11BSD
Description:
The noaccesstime option is missing from mount(8). This option
allows the administrator to avoid updating the read access time
on files.
Repeat-By:
mount -u -o noaccesstime /usr
Observe the error.
Fix:
The ability to turn off the updating of read access times is not
solely for transient/short-lived files. If one is running a
find / -name '*.c' -print | xargs grep MNT_
why bother updating the read times on all the inodes of files which
are grep'd? No one really pays attention to the read access time
anyways. Turning off the read access time updating before running
finds saves the kernel from having to do a lot of I/O which in turns
saves time. The time savings are not dramatic but a few seconds here
and there adds up. Question: How does a system get slow? Answer: One
second at a time ;-)
As an example, the command "find /usr -name '*.h' -print > /dev/null"
Normal: 21.2u 134.7s 3:24 76% 3128+508io
noaccesstime: 22.6u 130.3s 3:16 77% 3104+5io
Not updating the accesstimes (and this is just on the directories, the
.h files themselves are not being read) saved 500 writes to the disk
(about 2.5 per second over the 200 second the test took).
If /tmp is a separate filesystem it is a good idea to turn on
'noaccesstime' for it so that workfiles (such as 'ld' uses) don't
get their times updated as they're read repeatedly.
The following files are updated by the patch below:
/usr/src/sys/sys/ufs_mount.c
/usr/src/sys/sys/sys_inode.c
/usr/src/sys/sys/ufs_fio.c
/usr/src/sys/h/mount.h
/usr/src/sbin/mount/mntopts.h
/usr/src/sbin/mount/mount.c
/usr/src/sbin/mount/mount.8
/VERSION
To install this update cut where indicated, saving to a file (/tmp/379).
Then:
patch -p0 < /tmp/379
cd /usr/src/sbin/mount
make
make install
make clean
It is perfectly safe to install the new 'mount' command before booting
a new kernel. Until a new kernel is installed the 'MNT_NOATIME' bit
is masked off and ignored by the old kernel.
Then a new kernel is compiled. If you have existing .o files from
a previous compile this step will go quickly otherwise it will take
about an hour:
cd /sys/YOUR_KERNEL
make
cp -p /unix /ounix
cp -p /netnix /onetnix
make install
The two 'cp' commands are optional but recommended. They save the
current kernel for recovery purposes. In the unlikely event something
is wrong with the newly compiled kernel you can boot the "/genunix"
(emergency GENERIC kernel that everyone should keep around) and rename
'ounix' and 'onetnix' back to 'unix' and 'netnix' and then reboot with
a networking kernel that works. IF you have a broken kernel by all
means let me know about it.
reboot
You're all done. Enjoy.
As always this and previous updates to 2.11BSD are available via
anonymous FTP to either FTP.IIPO.GTEGSC.COM or MOE.2BSD.COM in the
directory /pub/2.11BSD.
===============================cut here====================
*** /usr/src/sys/sys/ufs_mount.c.old Sat Jan 18 23:01:05 1997
--- /usr/src/sys/sys/ufs_mount.c Sun Jun 29 16:27:23 1997
***************
*** 3,9 ****
* All rights reserved. The Berkeley software License Agreement
* specifies the terms and conditions for redistribution.
*
! * @(#)ufs_mount.c 2.0 (2.11BSD GTE) 1997/1/18
*/
#include "param.h"
--- 3,9 ----
* All rights reserved. The Berkeley software License Agreement
* specifies the terms and conditions for redistribution.
*
! * @(#)ufs_mount.c 2.1 (2.11BSD GTE) 1997/6/29
*/
#include "param.h"
***************
*** 96,102 ****
fs->fs_ronly = 0;
mp->m_flags &= ~MNT_RDONLY;
}
! #define _MF (MNT_NOSUID | MNT_NODEV | MNT_NOEXEC | MNT_ASYNC | MNT_SYNCHRONOUS)
mp->m_flags &= ~_MF;
mp->m_flags |= (uap->flags & _MF);
#undef _MF
--- 96,102 ----
fs->fs_ronly = 0;
mp->m_flags &= ~MNT_RDONLY;
}
! #define _MF (MNT_NOSUID | MNT_NODEV | MNT_NOEXEC | MNT_ASYNC | MNT_SYNCHRONOUS | MNT_NOATIME)
mp->m_flags &= ~_MF;
mp->m_flags |= (uap->flags & _MF);
#undef _MF
*** /usr/src/sys/sys/sys_inode.c.old Tue Feb 4 20:01:28 1997
--- /usr/src/sys/sys/sys_inode.c Thu Jul 3 19:46:01 1997
***************
*** 3,9 ****
* All rights reserved. The Berkeley software License Agreement
* specifies the terms and conditions for redistribution.
*
! * @(#)sys_inode.c 1.9 (2.11BSD GTE) 1997/1/30
*/
#include "param.h"
--- 3,9 ----
* All rights reserved. The Berkeley software License Agreement
* specifies the terms and conditions for redistribution.
*
! * @(#)sys_inode.c 1.10 (2.11BSD GTE) 1997/7/3
*/
#include "param.h"
***************
*** 126,132 ****
* non-sync directory i/o - the sync bit is forced on.
*/
if (uio->uio_rw == UIO_READ)
! ip->i_flag |= IACC;
else
{
switch (type)
--- 126,135 ----
* non-sync directory i/o - the sync bit is forced on.
*/
if (uio->uio_rw == UIO_READ)
! {
! if (!(ip->i_fs->fs_flags & MNT_NOATIME))
! ip->i_flag |= IACC;
! }
else
{
switch (type)
***************
*** 169,183 ****
if (type == IFREG || type == IFDIR && (ip->i_fs->fs_flags & MNT_ASYNC))
ioflag &= ~IO_SYNC;
! if (type == IFCHR) {
! if (uio->uio_rw == UIO_READ)
! error = (*cdevsw[major(dev)].d_read)(dev, uio, ioflag);
! else {
! ip->i_flag |= IUPD|ICHG;
! error = (*cdevsw[major(dev)].d_write)(dev, uio, ioflag);
! }
return (error);
! }
if (uio->uio_resid == 0)
return (0);
if (uio->uio_rw == UIO_WRITE && type == IFREG &&
--- 172,192 ----
if (type == IFREG || type == IFDIR && (ip->i_fs->fs_flags & MNT_ASYNC))
ioflag &= ~IO_SYNC;
! if (type == IFCHR)
! {
! if (uio->uio_rw == UIO_READ)
! {
! if (!(ip->i_fs->fs_flags & MNT_NOATIME))
! ip->i_flag |= IACC;
! error = (*cdevsw[major(dev)].d_read)(dev, uio, ioflag);
! }
! else
! {
! ip->i_flag |= IUPD|ICHG;
! error = (*cdevsw[major(dev)].d_write)(dev, uio, ioflag);
! }
return (error);
! }
if (uio->uio_resid == 0)
return (0);
if (uio->uio_rw == UIO_WRITE && type == IFREG &&
*** /usr/src/sys/sys/ufs_fio.c.old Mon Sep 16 21:09:30 1996
--- /usr/src/sys/sys/ufs_fio.c Thu Jul 3 19:47:42 1997
***************
*** 3,9 ****
* All rights reserved. The Berkeley software License Agreement
* specifies the terms and conditions for redistribution.
*
! * @(#)ufs_fio.c 1.4 (2.11BSD GTE) 1996/9/13
*/
#include "param.h"
--- 3,9 ----
* All rights reserved. The Berkeley software License Agreement
* specifies the terms and conditions for redistribution.
*
! * @(#)ufs_fio.c 1.5 (2.11BSD GTE) 1997/7/3
*/
#include "param.h"
***************
*** 173,179 ****
((vap->va_vaflags & VA_UTIMES_NULL) == 0 ||
access(ip, IWRITE)))
return(u.u_error);
! if (vap->va_atime != (time_t)VNOVAL)
ip->i_flag |= IACC;
if (vap->va_mtime != (time_t)VNOVAL)
ip->i_flag |= (IUPD|ICHG);
--- 173,180 ----
((vap->va_vaflags & VA_UTIMES_NULL) == 0 ||
access(ip, IWRITE)))
return(u.u_error);
! if (vap->va_atime != (time_t)VNOVAL &&
! !(ip->i_fs->fs_flags & MNT_NOATIME))
ip->i_flag |= IACC;
if (vap->va_mtime != (time_t)VNOVAL)
ip->i_flag |= (IUPD|ICHG);
*** /usr/src/sys/h/mount.h.old Thu Apr 18 21:26:40 1996
--- /usr/src/sys/h/mount.h Sun Jun 29 14:47:54 1997
***************
*** 3,9 ****
* All rights reserved. The Berkeley software License Agreement
* specifies the terms and conditions for redistribution.
*
! * @(#)mount.h 7.2.4 (2.11BSD GTE) 1996/4/18
*/
/*
--- 3,9 ----
* All rights reserved. The Berkeley software License Agreement
* specifies the terms and conditions for redistribution.
*
! * @(#)mount.h 7.2.5 (2.11BSD GTE) 1997/6/29
*/
/*
***************
*** 78,83 ****
--- 78,84 ----
#define MNT_NODEV 0x0010 /* don't interpret special files */
#define MNT_QUOTA 0x0020 /* quotas are enabled on filesystem */
#define MNT_ASYNC 0x0040 /* file system written asynchronously */
+ #define MNT_NOATIME 0x0080 /* don't update access times */
/*
* Mask of flags that are visible to statfs().
*** /usr/src/sbin/mount/mntopts.h.old Wed Feb 7 22:58:58 1996
--- /usr/src/sbin/mount/mntopts.h Sun Jun 29 15:22:10 1997
***************
*** 30,36 ****
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
! * @(#)mntopts.h 8.3.2 (2.11BSD) 1996/2/7
*/
struct mntopt {
--- 30,36 ----
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
! * @(#)mntopts.h 8.3.3 (2.11BSD) 1997/6/29
*/
struct mntopt {
***************
*** 41,46 ****
--- 41,47 ----
/* User-visible MNT_ flags. */
#define MOPT_ASYNC { "async", 0, MNT_ASYNC }
+ #define MOPT_NOATIME { "accesstime", 1, MNT_NOATIME }
#define MOPT_NODEV { "dev", 1, MNT_NODEV }
#define MOPT_NOEXEC { "exec", 1, MNT_NOEXEC }
#define MOPT_NOSUID { "suid", 1, MNT_NOSUID }
***************
*** 58,77 ****
#define MOPT_RQ { "rq", 1, MNT_RDONLY }
/* Ignored options (used for control in fstab) */
! #define MOPT_AUTO { "auto", }
! #define MOPT_NOAUTO { "na", }
#define MOPT_FSTAB_COMPAT \
MOPT_RO, \
MOPT_RW, \
! MOPT_RQ, \
! MOPT_NOAUTO, \
! MOPT_AUTO
/* Standard options which all mounts can understand. */
#define MOPT_STDOPTS \
MOPT_FSTAB_COMPAT, \
MOPT_QUOTAS, \
MOPT_NODEV, \
MOPT_NOEXEC, \
MOPT_NOSUID, \
--- 59,78 ----
#define MOPT_RQ { "rq", 1, MNT_RDONLY }
/* Ignored options (used for control in fstab) */
! #define MOPT_NOAUTO { "na", }, \
! { "auto", }
#define MOPT_FSTAB_COMPAT \
MOPT_RO, \
MOPT_RW, \
! MOPT_RQ
/* Standard options which all mounts can understand. */
#define MOPT_STDOPTS \
MOPT_FSTAB_COMPAT, \
MOPT_QUOTAS, \
+ MOPT_NOATIME, \
+ MOPT_NOAUTO, \
MOPT_NODEV, \
MOPT_NOEXEC, \
MOPT_NOSUID, \
*** /usr/src/sbin/mount/mount.c.old Sat Nov 16 20:34:31 1996
--- /usr/src/sbin/mount/mount.c Sun Jun 29 16:02:05 1997
***************
*** 36,42 ****
"@(#) Copyright (c) 1980, 1989, 1993, 1994\n\
The Regents of the University of California. All rights reserved.\n";
! static char sccsid[] = "@(#)mount.c 8.19.3 (2.11BSD) 1996/11/16";
#endif /* not lint */
#include <sys/param.h>
--- 36,42 ----
"@(#) Copyright (c) 1980, 1989, 1993, 1994\n\
The Regents of the University of California. All rights reserved.\n";
! static char sccsid[] = "@(#)mount.c 8.19.4 (2.11BSD) 1997/6/29";
#endif /* not lint */
#include <sys/param.h>
***************
*** 74,79 ****
--- 74,80 ----
char *o_name;
} optnames[] = {
{ MNT_ASYNC, "asynchronous" },
+ { MNT_NOATIME, "noaccesstime" },
{ MNT_NODEV, "nodev" },
{ MNT_NOEXEC, "noexec" },
{ MNT_NOSUID, "nosuid" },
*** /usr/src/sbin/mount/mount.8.old Sat Nov 16 20:34:12 1996
--- /usr/src/sbin/mount/mount.8 Thu Jul 3 20:15:04 1997
***************
*** 29,35 ****
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
! .\" @(#)mount.8 8.7.3 (2.11BSD) 1996/11/16
.\"
.TH MOUNT 8 "November 16, 1996"
.UC 7
--- 29,35 ----
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
! .\" @(#)mount.8 8.7.3 (2.11BSD) 1997/7/3
.\"
.TH MOUNT 8 "November 16, 1996"
.UC 7
***************
*** 100,110 ****
async
All I/O
to the file system should be done asynchronously.
! This is a
! .B dangerous
! flag to set,
! and should not be used unless you are prepared to recreate the file
! system should your system crash.
.TP 10
force
The same as
--- 100,109 ----
async
All I/O
to the file system should be done asynchronously.
!
! .B This is a dangerous flag to set,
! .B and should not be used unless you are prepared to recreate the file
! .B system should your system crash.
.TP 10
force
The same as
***************
*** 112,117 ****
--- 111,128 ----
forces the revocation of write access when trying to downgrade
a filesystem mount status from read-write to read-only. This is not
(and likely never will be) supported in 2.11BSD.
+ .TP 10
+ noaccesstime
+ File access times are not updated.
+
+ .B This is a performance optimization for filesystems used for largely
+ .B read-only, short-lived data, e.g., news.
+ .TP 10
+ noauto
+ This filesystem should be skipped when mount is run with the \fB\-a\fP flag.
+ .TP 10
+ na
+ Same as noauto.
.TP 10
nodev
Do not interpret character or block special devices on the file system.
*** /VERSION.old Sun Jul 6 20:31:24 1997
--- /VERSION Tue Jul 8 19:53:04 1997
***************
*** 1,5 ****
! Current Patch Level: 378
! Date: July 6, 1997
2.11 BSD
============
--- 1,5 ----
! Current Patch Level: 379
! Date: July 8, 1997
2.11 BSD
============