From mboxrd@z Thu Jan  1 00:00:00 1970
Message-ID: <66b9839fdb955f8f969063ccff722c4c@quanstro.net>
To: 9fans@9fans.net
From: erik quanstrom <quanstro@quanstro.net>
Date: Tue,  1 Jul 2008 09:25:12 -0400
In-Reply-To: <20080701120805.22ECF1E8C22@holo.morphisms.net>
MIME-Version: 1.0
Content-Type: text/plain; charset="US-ASCII"
Content-Transfer-Encoding: 7bit
Subject: Re: [9fans] 9vx
Topicbox-Message-UUID: d2bcdafa-ead3-11e9-9d60-3106f5b1d025

>> Here's the fix for the fdisk problem:
>>
>> /sys/src/cmd/disk/prep/edit.c:503,508 - edit.c:503,509
>>   	 */
>>   	for(i=0; i<edit->nctlpart; i++) {
>>   		p = edit->ctlpart[i];
>> + 		if(strncmp(p->ctlname, "data", 5) != 0)
>>   		if(p->changed)
>>   		if(fprint(ctlfd, "delpart %s\n", p->ctlname)<0) {
>>   			fprint(2, "delpart failed: %s: %r\n", p->ctlname);

on second read, with this approach, i would think that strcmp() not
strncmp should be used.

>
> That would work, but one wonders why
> the normal kernel doesn't have this problem.

this must be a quirk of the interaction between
devsd and fdisk.  by hand data does disappear:

	; lc
	9fat	ctl	data	nvram	plan9	raw
	; for(i in 9fat data nvram plan9 data)echo delpart $i>ctl
	; lc
	ctl	raw

by the way, be very careful with this before
applying this patch:

; diff -c /sys/src/9/port/devsd.c /n/dump/2008/0701/sys/src/9/port/devsd.c
/sys/src/9/port/devsd.c:147,153 - /n/dump/2008/0701/sys/src/9/port/devsd.c:147,152
  	 */
  	pp = unit->part;
  	for(i = 0; i < unit->npart; i++){
- 		if(pp->name)
  		if(strcmp(name, pp->name) == 0)
  			break;
  		pp++;

this is required because npart is set to the number
of partitions allocated.  the names never-set partitions
might be 0.  otherwise "delpart missingpart>/dev/sdXX/ctl"
will be a noisy and somewhat gratituous synonym for
"echo reboot>/dev/reboot".

- erik