[linux-lvm] memlock_inc increased device open count problem

[linux-lvm] memlock_inc increased device open count problem

[niko]

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Hi,everyone
I'm using mpatocka's patches for shared snapshot on RHEL6.
Problem occurred when creating shared cow storage volume.
the same problem occurred when creating snapshot
I got error message:

  Unable to deactivate open vgtest-orig--shared (253:2)
  Aborting. Couldn't deactivate snapshot COW area. Manual intervention
required.
Then,I did some digging, in lv_deactivate

@@ -1117,6 +1121,9 @@
                stack;
        memlock_inc(cmd);
+       if (!lv_info(cmd, lv, 0, &info, 1, 0))
+               goto_out;
+       log_verbose("lv_deactivate: open_count %d", info.open_count);
        r = _lv_deactivate(lv);
        memlock_dec(cmd);
        fs_unlock();
it turns out :

 lv_deactivate: open_count 1
before memlock_inc, open_count is 0

I wonder how it changes to 1 ?

-- 
niko

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