• James Bottomley's avatar
    enclosure: fix WARN_ON removing an adapter in multi-path devices · 11e52a69
    James Bottomley authored
    We have peculiar problems with multi-path and enclosures: physically, we know
    each bay can only be occupied by a single disk device.  However in multi-path,
    it appears we have many (because each path to the device appears in Linux as a
    different kernel device).  We try to fix this by only having the last seen
    device show up in the bay.
    
    Sysfs gets very annoyed if we try to manipulate links when the kobject sysfs
    directory (kobj.sd) doesn't exist and drops a huge WARN_ON which most users
    panic and report an oops for.  This happens on a few path removal situations
    and IBM reports seeing it when one of their multi-path adapters is removed.
    
    Add a check to enclosure device removal for the existence the sysfs directory
    containing both the forward and back links so that the remnants (if any) get
    removed in either direction but no scary warnings are dumped.
    Reported-by: default avatarWen Xiong <wenxiong@linux.vnet.ibm.com>
    Tested-by: default avatarWen Xiong <wenxiong@linux.vnet.ibm.com>
    Signed-off-by: default avatarJames Bottomley <JBottomley@Parallels.com>
    11e52a69
enclosure.c 18.7 KB