2001-02-27 20:02:42

by Petr Konecny

[permalink] [raw]
Subject: Disk change messages

Hi,

I've been trying to use vold to automount CDs. The daemon tries to open
/dev/cdrom and if it succeeds it examines the media and mounts it under
/cdrom/volume_name.

The problem is that when there is no disk in the drive the following
message:
VFS: Disk change detected on device ide1(22,0)
is written to system log during each open call. Vold calls open every 5
seconds, so it's 17280 lines in log/day. I have been able to avoid these
messages by commenting out a line in drivers/ide/ide-cd.c (patch
included) and have not seen any problems yet.

I guess I have three questions:
1. can this patch break things ? I suppose it could happen only
if cdrom_saw_media_change was not called when the CD is changed.
2. is it possible to avoid the message by modifying vold ? E.g. finding
out that there is no media in the drive without calling open.
3. is there a clean way to avoid these repeated messages ?

Thanks, Petr

--- ide-cd.c 2001/02/22 22:30:02 1.1.1.11
+++ ide-cd.c 2001/02/27 19:51:58
@@ -601,7 +601,7 @@

/* Check for tray open. */
if (sense_key == NOT_READY) {
- cdrom_saw_media_change (drive);
+/* cdrom_saw_media_change (drive); */
} else if (sense_key == UNIT_ATTENTION) {
/* Check for media change. */
cdrom_saw_media_change (drive);


2001-03-01 20:30:36

by Pavel Machek

[permalink] [raw]
Subject: Re: Disk change messages

Hi!

> I've been trying to use vold to automount CDs. The daemon tries to open
> /dev/cdrom and if it succeeds it examines the media and mounts it under
> /cdrom/volume_name.
>
> The problem is that when there is no disk in the drive the following
> message:
> VFS: Disk change detected on device ide1(22,0)
> is written to system log during each open call. Vold calls open every 5
> seconds, so it's 17280 lines in log/day. I have been able to avoid these
> messages by commenting out a line in drivers/ide/ide-cd.c (patch
> included) and have not seen any problems yet.
>
> I guess I have three questions:
> 1. can this patch break things ? I suppose it could happen only

No.

> 2. is it possible to avoid the message by modifying vold ? E.g. finding
> out that there is no media in the drive without calling open.

Don't think so.

> 3. is there a clean way to avoid these repeated messages ?

Syslogdshould sumarize "last message repeated 123456 times"
.

> Thanks, Petr
>
> --- ide-cd.c 2001/02/22 22:30:02 1.1.1.11
> +++ ide-cd.c 2001/02/27 19:51:58
> @@ -601,7 +601,7 @@
>
> /* Check for tray open. */
> if (sense_key == NOT_READY) {
> - cdrom_saw_media_change (drive);
> +/* cdrom_saw_media_change (drive); */
> } else if (sense_key == UNIT_ATTENTION) {
> /* Check for media change. */
> cdrom_saw_media_change (drive);
>
> -
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--
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