• Stephen M. Cameron's avatar
    [SCSI] hpsa: fix bug in adjust_hpsa_scsi_table · 2a8ccf31
    Stephen M. Cameron authored
    
    
    fix bug in adjust_hpsa_scsi_table which caused devices which have
    changed size, etc. to do the wrong thing.
    
    The problem was as follows:
    
    The driver maintains its current idea of what devices are present
    in the h->dev[] array.  When it updates this array, it scans the
    hardware, and produces a new list of devices, call it sd[], for
    scsi devices.
    
    Then, it compares each item in h->dev[] vs. sd[], and any items which
    are not present sd it removes from h->dev[], and any items present
    in sd[], but different, it modifies in h->dev[].
    
    Then, it looks for items in sd[] which are not present in h->dev[],
    and adds those items into h->dev[].  All the while, it keeps track
    of what items were added and removed to/from h->dev[].
    
    Finally, it updates the SCSI mid-layer by removing and adding
    the same devices it removed and added to/from h->dev[]. (modified
    devices count as a remove then add.)
    
    originally, when a "changed" device was discovered, it was
    removed then added to h->dev[].  The item was added to the *end*
    of h->dev[].  And, the item was removed from sd[] as well
    (nulled out).  As it processed h->dev[], these newly added items
    at the end of the list were encountered, and sd[] was searched,
    but those items were nulled out.  So they ended up getting removed
    immediately after they were added.
    
    The solution is to have a way to replace items in the h->dev[]
    array instead of doing a remove + add.  Then the "changed" items.
    are not encountered a second time, and removed.
    Signed-off-by: default avatarStephen M. Cameron <scameron@beardog.cce.hp.com>
    Signed-off-by: default avatarJames Bottomley <James.Bottomley@suse.de>
    2a8ccf31