[78] in linux-scsi channel archive
Re: Buffer cache and bad blocks.
daemon@ATHENA.MIT.EDU (Linux mailinglist receiver)
Thu Feb 16 19:31:23 1995
To: paul@rasty.anu.edu.au (Paul Gortmaker)
Date: Thu, 16 Feb 1995 23:21:07 +0100 (MET)
Cc: linux-kernel@vger.rutgers.edu, linux-scsi@vger.rutgers.edu
In-Reply-To: <199502161138.AA00286@rasty.anu.edu.au> from "Paul Gortmaker" at Feb 16, 95 10:38:24 pm
Reply-To: pe1chl@wab-tis.rabobank.nl
From: linux@sys3.pe1chl.ampr.org (Linux mailinglist receiver)
According to Paul Gortmaker:
> I am not sure if this is a problem, but it appears that the
> kernel will keep reads from bad blocks in the buffer cache. Here is
> an example. After getting these read errors...
>
> scsi0 : resetting for second half of retries.
> SCSI disk error : host 0 id 0 lun 0 return code = 18000002
> Current error sd803: sense key Medium Error
> Additional sense indicates Unrecovered read error
> scsidisk I/O error: dev 0803, sector 613488
> SCSI disk error : host 0 id 0 lun 0 return code = 18000002
> Current error sd803: sense key Medium Error
> Additional sense indicates Unrecovered read error
> scsidisk I/O error: dev 0803, sector 613490
>
> and then unmounting the partition that had the errors, one gets:
>
> foobar:~# umount -v /tmp
> Weird - unlocked, clean and not uptodate buffer on list 0 803 306744
> Weird - unlocked, clean and not uptodate buffer on list 0 803 306745
> Weird - unlocked, clean and not uptodate buffer on list 0 803 306744
> Weird - unlocked, clean and not uptodate buffer on list 0 803 306745
> /dev/sda3 umounted
> foobar:~#
>
> Note that the kernel reports the same numbers ( *0.5 ) as the read errors.
> You can remount the fs, and you will get the same "Wierd - unlocked..."
> messages upon unmounting. However, if you run some bogus program that
> will eat up all the buffer cache, then you will not get this error
> message anymore (indicating that the offending buffers are now flushed
> from the system cache.)
>
> This was with 1.1.90 (I think...) with the buslogic scsi driver.
> I have since low-leveled these errors into oblivion, so I can't
> reproduce it.
This is certainly nothing new. I am using an Adaptec 1542B ome time ago
I had errors on a CD-ROM, and later on a SCSI disk. In both cases the
same thing happened.
(I reported it on the SCSI channel and asked on the news what the feeling
was what should happen on disk read errors (one time my system paniced),
but I got no response)
Rob
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| Rob Janssen rob@knoware.nl | AMPRnet: rob@pe1chl.ampr.org |
| e-mail: pe1chl@wab-tis.rabobank.nl | AX.25 BBS: PE1CHL@PI8UTR.#UTR.NLD.EU |
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