Re3: idetape broke in 2.4.x-2.4.9-ac5 (write OK but not read)

Re3: idetape broke in 2.4.x-2.4.9-ac5 (write OK but not read)

[Floydsmith]

>>> - block size: The 2.4 ide-tape driver only works reliably if you
>>>   write data with the correct block size. If you don't write full
>>>   blocks the last block of data may not be readable.
>>
>>I fixed that some time ago, it's in current -ac
>>if not in Linus's tree.

>Sorry, but that's not correct. I just ran a test, and the bug is
>still there in 2.4.9-ac7. Maybe you're thinking of some other bug?

>ide-tape tells me it uses a 14*26KB buffer for my Seagate STT8000A.
>If I dd a 39KB (1.5 "buffer units") file with bs=1k to /dev/ht0 it tells
>me it wrote 39 blocks. If I then rewind and dd with bs=1k from /dev/ht0
>it only reads 26 blocks. The same happens in 2.2 + Hedrick's IDE patch.

>2.2 vanilla reads 56 blocks, of which the first 39 are identical to
>what I initially wrote. The last 13 contain junk but that's not a big
>problem since I back up with tar which writes its own EOF mark.
>./Mikael
>-

The output is:
ide-tape: ht0: I/O error, pc =  8, key =  5, asc = 2c, ascq =  0
for reads only.
As noted earlier, this problem occurs in 2.4.x (only) even with a very small 
test file (just the 5 character "test"). Upon sprinkling some "printk" 
statements arround in ide-tape.c I found that what happens with this error 
(under 2.4.x) is:
    if (tape->failed_pc != NULL && tape->pc->c[0] == 
IDETAPE_REQUEST_SENSE_CMD) {
        return idetape_issue_packet_command (drive, tape->failed_pc);
    }
invokes idetape_issue_packet_command (...) three times in idetape_do_request 
(...) which causes an abort in idetape_issue_packet_command (...) when 
pc->retries reaches 4.
I don't get ANY retries with the same test case under 2.2.x.

Is there any way I can find out what the error return value asc = 2c 
represents? For example, is there a URL to a "standard" for such values?

Floyd,

Re: Re3: idetape broke in 2.4.x-2.4.9-ac5 (write OK but not read)

[Willem Riede]

Floydsmith@aol.com wrote:
> 
> The output is:
> ide-tape: ht0: I/O error, pc =  8, key =  5, asc = 2c, ascq =  0
> 
> Is there any way I can find out what the error return value asc = 2c
> represents? For example, is there a URL to a "standard" for such values?
> 
The above error is "command sequence error" - according to the
draft SCSI-2 standard that I was once able to find on the net
(but I forget where).

Success. Willem Riede.