SCSI Tape driver problem

["vijay srinath" <vijaysrinath@lycos.com>]

hello all,

    I noticed a bug in the scsi tape class driver in kernel 2.2.16/2.4.x.
This is the test that i ran. 
1. I have two scsi-fc tape devices
2. I insert the hba driver, so that both the tape devices are enabled and map to st0 and st1
3. I remove the device that maps to st0 using 
   echo "scsi remove-single-device 0 0 0 0" > /proc/scsi/scsi
4. Now, if i try to do an open("/dev/st1",..), the process hangs as the open call never returns.

    The problem seems to be in the callback function st_sleep_done() where the following comparison is being made
if ((st_nbr = TAPE_NR(SCpnt->request.rq_dev)) < st_template.nr_dev) 
{
 ...
}

This comparision fails for the above test since nr_dev will be 1 and 
TAPE_NR() will also be 1 for /dev/st1. Hence the semaphore 
SCpnt->request.sem never gets released and open waits forever.


    Can somebody please let me know why this comparison is needed ?

regards
vijay



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