Date: Sat, 22 Dec 2001 19:54:50 -0500 From: The Anarcat <anarcat@anarcat.dyndns.org> To: Jordan Hubbard <jkh@winston.freebsd.org> Cc: arch@FreeBSD.ORG, jkh@FreeBSD.ORG Subject: Re: sysctl kern.disks shouldn't have to sort its output Message-ID: <20011223005449.GE530@shall.anarcat.dyndns.org> In-Reply-To: <33483.1009066876@winston.freebsd.org> References: <20011222230759.GD530@shall.anarcat.dyndns.org> <33483.1009066876@winston.freebsd.org>
next in thread | previous in thread | raw e-mail | index | archive | help
--7uYPyRQQ5N0D02nI
Content-Type: multipart/mixed; boundary="bGR76rFJjkSxVeRa"
Content-Disposition: inline
--bGR76rFJjkSxVeRa
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable
On Sat Dec 22, 2001 at 04:21:16PM -0800, Jordan Hubbard wrote:
> > Anyways. If the sorting belongs to the kernel, I could do it.
> >=20
> > However, I think it belongs to libdisk, so I'll start working on a patch
> > there.
>=20
> The sorting could be in libdisk, I just suggested the kernel so that
> other consumers of the kern.disks sysctl variable wouldn't have to
> sort it as well.=20
Yes, of course. But I wonder how best it would be implemented... By
controlling how entries are added to the list, or by controlling how he
prints those entries?
Because it is a list, sorting it is not very efficient. At the output
though (outside sysctl_disks and therefore outside the kernel), it's a
string, so it's easier to manipulate. I think a list-sorting algorithm
for that little thing would be a bloat in the kernel. Also, if we can
figure out where the order comes from, we might want to keep it
unsorted, as a feature. :P
Am I wrong?
> One assumes that more than libdisk might want to get
> at this data.=20
Then these consumers have to assume that the data is unsorted. Anyways,
it's much easier to do it oustide the kernel.
> In any case, for this particular case doing it in
> libdisk would be fine.
Here is a quick hack on libdisk to deal with this. It uses qsort since I
wanted to see how it works but anyone is free to implement its own
algorithm. ;)
And actually, it might be best to use mergesort since the entries are
likely to be sorted.
This patches changes a meaningless variable name, adds a auxiliary
comparaison function (since strcmp doesn't take **char pointers), and
removes extra return's to leave just one at the end.
A.
--bGR76rFJjkSxVeRa
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment; filename=patch1
Content-Transfer-Encoding: quoted-printable
Index: Makefile
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
RCS file: /home/ncvs/src/lib/libdisk/Makefile,v
retrieving revision 1.27.2.5
diff -u -r1.27.2.5 Makefile
--- Makefile 18 Sep 2001 06:47:30 -0000 1.27.2.5
+++ Makefile 22 Dec 2001 23:58:22 -0000
@@ -6,7 +6,7 @@
INCS=3D libdisk.h
=20
# Remove KERN_DISKS_BROKEN when kern.disks sysctl returns disks in sorted =
order
-CFLAGS+=3D -Wall -DKERN_DISKS_BROKEN
+CFLAGS+=3D -Wall
.if ${MACHINE} =3D=3D "pc98"
CFLAGS+=3D -DPC98
.endif
Index: disk.c
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
RCS file: /home/ncvs/src/lib/libdisk/disk.c,v
retrieving revision 1.50.2.14
diff -u -r1.50.2.14 disk.c
--- disk.c 18 Sep 2001 06:47:30 -0000 1.50.2.14
+++ disk.c 23 Dec 2001 00:43:01 -0000
@@ -483,10 +483,18 @@
static char * device_list[] =3D {"aacd", "ad", "da", "afd", "fla", "idad",=
"mlxd", "amrd", "twed", "ar", "fd", 0};
#endif
=20
+int qstrcmp(const void* a, const void* b) {
+
+ char *str1 =3D *(char**)a;
+ char *str2 =3D *(char**)b;
+ return strcmp(str1, str2);
+
+}
+
char **
Disk_Names()
{
- int i,j,k;
+ int i,j,disk_cnt;
char disk[25];
char diskname[25];
struct stat st;
@@ -506,14 +514,16 @@
error =3D sysctlbyname("kern.disks", disklist, &listsize, NULL, 0);
if (error)=20
return NULL;
- k =3D 0;
- for (dp =3D disks; ((*dp =3D strsep(&disklist, " ")) !=3D NULL) && k =
< MAX_NO_DISKS; k++, dp++);
- return disks;
- }
+ disk_cnt =3D 0;
+ for (dp =3D disks; ((*dp =3D strsep(&disklist, " ")) !=3D NULL) &&=20
+ disk_cnt < MAX_NO_DISKS; disk_cnt++, dp++);
+ } else {
warn("kern.disks sysctl not available");
#endif
- k =3D 0;
+ disk_cnt =3D 0;
for (j =3D 0; device_list[j]; j++) {
+ if(disk_cnt >=3D MAX_NO_DISKS)
+ break;
for (i =3D 0; i < MAX_NO_DISKS; i++) {
sprintf(diskname, "%s%d", device_list[j], i);
sprintf(disk, _PATH_DEV"%s", diskname);
@@ -529,12 +539,17 @@
continue;
}
close(fd);
- disks[k++] =3D strdup(diskname);
- if(k =3D=3D MAX_NO_DISKS)
- return disks;
+ disks[disk_cnt++] =3D strdup(diskname);
+ if(disk_cnt >=3D MAX_NO_DISKS)
+ break;
}
}
- return disks;
+#if !defined(PC98) && !defined(KERN_DISKS_BROKEN)
+ }
+#endif
+ qsort(disks, disk_cnt, sizeof(char*), qstrcmp);
+ =20
+ return disks;
}
=20
#ifdef PC98
--bGR76rFJjkSxVeRa--
--7uYPyRQQ5N0D02nI
Content-Type: application/pgp-signature
Content-Disposition: inline
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.0.6 (FreeBSD)
Comment: For info see http://www.gnupg.org
iEYEARECAAYFAjwlK1gACgkQttcWHAnWiGcJjACgh5WL5wD85/hyrMCIzYBl26xI
g9QAnA2E4wU1jxvU/lVCG43UbfhP24PX
=S4yR
-----END PGP SIGNATURE-----
--7uYPyRQQ5N0D02nI--
To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-arch" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20011223005449.GE530>