[Bacula-bugs] [bacula 0000906]: After a bad restoration, device can stay in read mode (Reader=1)

[<bac...@li...>]

A NOTE has been added to this issue. 
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http://bugs.bacula.org/view.php?id=906 
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Reported By:                ebollengier
Assigned To:                ebollengier
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Project:                    bacula
Issue ID:                   906
Category:                   Storage Daemon
Reproducibility:            always
Severity:                   minor
Priority:                   normal
Status:                     feedback
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Date Submitted:             07-27-2007 09:53 EDT
Last Modified:              07-29-2007 08:52 EDT
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Summary:                    After a bad restoration, device can stay in read
mode (Reader=1)
Description: 
I have 2 storage deamon with 2 different media type. When i use the wrong
storage to do my job (because i'm dumb), it fail and keep my device in
read mode.

In Use Volume status:
R30072 on device "S1_L180_LTO1" (/dev/lto1)
    Reader=1 writers=0 reserved=0
R30085 on device "S1_L180_LTO2" (/dev/lto2)
    Reader=1 writers=0 reserved=0
====

Data spooling: 0 active jobs, 0 bytes; 51 total jobs, 50,032,356,656 max
bytes/job.
Attr spooling: 0 active jobs, 0 bytes; 51 total jobs, 158,664,603 max
bytes.


I have to restart the storage deamon to be able to use this device again.

The problem seems to be in src/stored/acquire.c acquire_device_for_read()

 * Acquire device for reading. 
 *  The drive should have previously been reserved by calling 
 *  reserve_device_for_read(). We read the Volume label from the block
and
 *  leave the block pointers just after the label.

reserve_device_for_read find a device, and use set_read() to "lock" it for
reading. acquire_device_for_read() see that the drive type is uncompatible
with
the media type, and try to use an other drive and leave the first device
in read mode if no other drive can be found.

I think, we have to add something like detach_dcr_from_dev(); near 
src/stored/acquire.c:158 to release the drive after the error.

   /*
    * If the MediaType requested for this volume is not the
    *  same as the current drive, we attempt to find the same
    *  device that was used to write the orginal volume.  If
    *  found, we switch to using that device.
    */
...
      } else {
         /* error */
         Jmsg1(jcr, M_FATAL, 0, _("No suitable device found to read Volume
\"%s\"\n"),
            vol->VolumeName);
         jcr->dcr = dcr_save;
         goto get_out;
      }


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---------------------------------------------------------------------- 
 kern - 07-28-07 06:18  
---------------------------------------------------------------------- 
Unfortunately, I think it is probably quite a bit more complicated than
just adding a detach_dcr_from_dev();  The problem is that this particular
code was experimental, and when I rewrote the reservations code, the use of
the dcr changed, so this code must be rewritten.  It can probably be
simplified since the new_dcr() routine now does most of the work that was
done here allowing Bacula to switch drives more easily.

 

---------------------------------------------------------------------- 
 kern - 07-29-07 08:52  
---------------------------------------------------------------------- 
Please test with the current SVN rev 5263, which hopefully will fix this
problem.  

If it doesn't fix it, we will need to make some sort of regression test
for it so that I can duplicate the problem here. 

Issue History 
Date Modified   Username       Field                    Change               
====================================================================== 
07-27-07 09:53  ebollengier    New Issue                                    
07-27-07 09:53  ebollengier    Status                   new => assigned     
07-27-07 09:53  ebollengier    Assigned To               => ebollengier     
07-27-07 09:53  ebollengier    File Added: log.sd                           
07-28-07 06:18  kern           Note Added: 0002628                          
07-28-07 06:18  kern           Status                   assigned => feedback
07-29-07 08:52  kern           Note Added: 0002630                          
======================================================================