Messages in this thread |  | | Date | Wed, 29 May 1996 23:54:47 -0700 | From | "Leonard N. Zubkoff" <> | Subject | Re: pre2.0.9 (was Re: CD-ROM Access Crashes) |
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Date: Thu, 30 May 1996 09:33:41 +0300 (EET DST) From: Linus Torvalds <torvalds@cs.Helsinki.FI>
Note that you might want to try out #9 of the pre-2.0 series. There were still some problems in the generic read handling when errors occurred, and I hope those are finally fixed (knock wood - the code is certainly not trivial, and I haven't been able to test). Pre-#9 also contains the SCSI fixes from Leonard, so people who have seen problems with SCSI cd's, could you please check this out and see if we have them more-or-less nailed now?
I have verified that dd'ing a CD-R no longer kills my system nor does reading a bad block. I was able to read all the good files on my test CD, with the bad ones getting I/O errors. It took 1.5 hours to read it all, but there were no resets and the system worked fine both during and after the test. However, it does look like there are repeated requests for the same block, as in this excerpt:
May 29 14:43:00 gwynedd kernel: CD-ROM I/O error: dev 0b:00, sector 981760 May 29 14:43:01 gwynedd kernel: CD-ROM I/O error: dev 0b:00, sector 981764 May 29 15:43:17 gwynedd kernel: CD-ROM I/O error: dev 0b:00, sector 981760 May 29 15:43:17 gwynedd kernel: CD-ROM I/O error: dev 0b:00, sector 981764 May 29 15:47:13 gwynedd kernel: CD-ROM I/O error: dev 0b:00, sector 547212 May 29 15:47:18 gwynedd kernel: CD-ROM I/O error: dev 0b:00, sector 547214 May 29 15:47:23 gwynedd kernel: CD-ROM I/O error: dev 0b:00, sector 547216 May 29 15:47:28 gwynedd kernel: CD-ROM I/O error: dev 0b:00, sector 547218 May 29 15:47:33 gwynedd kernel: CD-ROM I/O error: dev 0b:00, sector 547220 May 29 15:47:37 gwynedd kernel: CD-ROM I/O error: dev 0b:00, sector 547212 May 29 15:47:42 gwynedd kernel: CD-ROM I/O error: dev 0b:00, sector 547222 May 29 15:47:47 gwynedd kernel: CD-ROM I/O error: dev 0b:00, sector 547214 May 29 15:47:50 gwynedd kernel: CD-ROM I/O error: dev 0b:00, sector 547224 May 29 15:47:55 gwynedd kernel: CD-ROM I/O error: dev 0b:00, sector 547216 May 29 15:48:00 gwynedd kernel: CD-ROM I/O error: dev 0b:00, sector 547226 May 29 15:48:05 gwynedd kernel: CD-ROM I/O error: dev 0b:00, sector 547218 May 29 15:48:11 gwynedd kernel: CD-ROM I/O error: dev 0b:00, sector 547228 May 29 15:48:16 gwynedd kernel: CD-ROM I/O error: dev 0b:00, sector 547212 May 29 15:48:23 gwynedd kernel: CD-ROM I/O error: dev 0b:00, sector 547230 May 29 15:48:28 gwynedd kernel: CD-ROM I/O error: dev 0b:00, sector 547214 May 29 15:48:35 gwynedd kernel: CD-ROM I/O error: dev 0b:00, sector 547232 May 29 15:48:40 gwynedd kernel: CD-ROM I/O error: dev 0b:00, sector 547216 May 29 15:48:48 gwynedd kernel: CD-ROM I/O error: dev 0b:00, sector 547218
What's definitely not implemented as yet is for a SCSI command that fails with a MEDIUM ERROR to be processed as a partial success and a partial failure. The entire command is treated as having failed. In addition, it will still signal an I/O error when a bad sector is encountered, even if we're really at the logical end of the CD-R.
Leonard
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