want to create readonly block backstore from otherwise mounted block device.

[stefan j kozak]

i want to use /dev/sda1 (which is already mounted r/w elsewhere) as a r/o block backstore.   
it wont let me and I dont see why that isnt allowable...

------snip start
/backstores/block> create sda /dev/sda1 true
Cannot configure StorageObject because device /dev/sda1 is already in use
------snip stop

So..... i commented out the "raise RTSLibError("Cannot configure Storag.... "  in rtslib_fb/tcm.py  class BlockStorageObject(StorageObject): _configure  to see where that got me.
turns out it blows up again trying to fwrite(path, "1\n")  where path is   "/sys/kernel/config/target/core/iblock_2/MOOOOOO/enable" , so the kernel is complaining i guess? 
why does it need to write 1 there to enable it?  what is it enabling exactly,  LIO?

now, i'm no dummy, and I know when i'm out of my element....  so just how does targetcli-fb  go about setting up LIO to make a target anyways?  
Shouldn't making a readonly backstore be a no-risk kinda thing?   
Is there a way to bypass targetcli-fb and do this manually?

Not really seeking a feature add, but more rather understanding at what's at play here, and ill keep plugging along to see if I cant figure it out on my own, too.
(trying to make a FC target here in this instance if it matters)

stay corvid-free,  
thanks in advance,
joe.     
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