• Steffen Maier's avatar
    scsi: zfcp: fix missing REC trigger trace on terminate_rport_io early return · 24558a87
    Steffen Maier authored
    commit 96d92704 upstream.
    
    get_device() and its internally used kobject_get() only return NULL if they
    get passed NULL as argument. zfcp_get_port_by_wwpn() loops over
    adapter->port_list so the iteration variable port is always non-NULL.
    Struct device is embedded in struct zfcp_port so &port->dev is always
    non-NULL. This is the argument to get_device().  However, if we get an
    fc_rport in terminate_rport_io() for which we cannot find a match within
    zfcp_get_port_by_wwpn(), the latter can return NULL.  v2.6.30 commit
    70932935 ("[SCSI] zfcp: Fix oops when port disappears") introduced an
    early return without adding a trace record for this case.  Even if we don't
    need recovery in this case, for debugging we should still see that our
    callback was invoked originally by scsi_transport_fc.
    
    Example trace record formatted with zfcpdbf from s390-tools:
    
    Timestamp      : ...
    Area           : REC
    Subarea        : 00
    Level          : 1
    Exception      : -
    CPU ID         : ..
    Caller         : 0x...
    Record ID      : 1
    Tag            : sctrpin        SCSI terminate rport I/O, no zfcp port
    LUN            : 0xffffffffffffffff                     none (invalid)
    WWPN           : 0x<wwpn>               WWPN
    D_ID           : 0x<n_port_id>          N_Port-ID
    Adapter status : 0x...
    Port status    : 0xffffffff             unknown (-1)
    LUN status     : 0x00000000                             none (invalid)
    Ready count    : 0x...
    Running count  : 0x...
    ERP want       : 0x03                   ZFCP_ERP_ACTION_REOPEN_PORT_FORCED
    ERP need       : 0xc0                   ZFCP_ERP_ACTION_NONE
    Signed-off-by: default avatarSteffen Maier <maier@linux.ibm.com>
    Fixes: 70932935 ("[SCSI] zfcp: Fix oops when port disappears")
    Cc: <stable@vger.kernel.org> #2.6.38+
    Reviewed-by: default avatarBenjamin Block <bblock@linux.ibm.com>
    Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    24558a87
zfcp_erp.c 46.7 KB