Re: Linux Virtual SCSI HBAs and Virtual disks

[Aboo Valappil <aboo@aboo.org>]

Stefan Richter wrote:
> Aboo Valappil wrote:
>   
>> I implemented a new IOCTL to remove  this  scsi_host  if the user 
>> process really needs to.  This removal  will first  finish all the SCSI 
>> commands (With the above status results) queued on the scsi_host  (If at 
>> all) and then remove the scsi_host.  Also the module unload will delete 
>> all the scsi_hosts created after finishing all the commands queued with 
>> the above status and sense information.
>>     
>
> This is a valid approach, but probably more useful would be something like:
>   - userspace device server or "modprobe -r" or procfs/sysfs magic or
>     whatever else requests removal of a Scsi_Host (or merely of a single
>     scsi_device),
>   - vscsihba enters scsi_remove_host() or scsi_remove_device(),
>   - SCSI core and upper layers do whatever it takes to withdraw from
>     the respective I-T(-L) nexus gracefully (e.g. synchronize cache,
>     unlock drive door...),
>   
Does this happen automatically when the scsi_remove_host() is called, or 
I have to explicitly tell the upper layers to start shutting down 
gracefully?