• Kiran Patil's avatar
    tcm_fc: Handle DDP/SW fc_frame_payload_get failures in ft_recv_write_data · dcd998cc
    Kiran Patil authored
    Problem: HW DDP context was not invalidated in case of ABORTS, etc...
    This leads to the problem where memory pages which are used for DDP
    as user descriptor could get reused for some other purpose (such as to
    satisfy new memory allocation request either by kernel or user mode threads)
    and since HW DDP context was not invalidated, HW continue to write to
    those pages, hence causing memory corruption.
    
    Fix: Either on incoming ABORTS or due to exchange time out, allowed the
    target to cleanup HW DDP context if it was setup for respective ft_cmd.
    Added new function to perform this cleanup, furthur it can be enhanced
    for other cleanup activity.  Fix ft_recv_write_data() to properly handle
    fc_frame_payload_get to return pointer to payload if it exist. If there is
    no payload which is most common case (+ve case in case if DDP is working
    as expected, it will return NULL. Yes, scope of buf is limited to printk.
    Invalidation of HW context (which is done inside ft_invl_hw_context() is
    necessary in SUCCESS and FAILURE case of DDP. Hence invalidation is DONE
    as long as there was DDP setup (whether it worked correctly or not,
    
    NOTE: For some reason, if there is any error w.r.t DDP such as out of
    order packet reception, HW simply post the full packet in rx queue.
    Signed-off-by: default avatarKiran Patil <kiran.patil@intel.com>
    Cc: Robert W Love <robert.w.love@intel.com>
    Signed-off-by: default avatarNicholas A. Bellinger <nab@linux-iscsi.org>
    dcd998cc
tcm_fc.h 5.34 KB