• Keith Mannthey's avatar
    block: Supress Buffer I/O errors when SCSI REQ_QUIET flag set · 08bafc03
    Keith Mannthey authored
    Allow the scsi request REQ_QUIET flag to be propagated to the buffer
    file system layer. The basic ideas is to pass the flag from the scsi
    request to the bio (block IO) and then to the buffer layer.  The buffer
    layer can then suppress needless printks.
    
    This patch declutters the kernel log by removed the 40-50 (per lun)
    buffer io error messages seen during a boot in my multipath setup . It
    is a good chance any real errors will be missed in the "noise" it the
    logs without this patch.
    
    During boot I see blocks of messages like
    "
    __ratelimit: 211 callbacks suppressed
    Buffer I/O error on device sdm, logical block 5242879
    Buffer I/O error on device sdm, logical block 5242879
    Buffer I/O error on device sdm, logical block 5242847
    Buffer I/O error on device sdm, logical block 1
    Buffer I/O error on device sdm, logical block 5242878
    Buffer I/O error on device sdm, logical block 5242879
    Buffer I/O error on device sdm, logical block 5242879
    Buffer I/O error on device sdm, logical block 5242879
    Buffer I/O error on device sdm, logical block 5242879
    Buffer I/O error on device sdm, logical block 5242872
    "
    in my logs.
    
    My disk environment is multipath fiber channel using the SCSI_DH_RDAC
    code and multipathd.  This topology includes an "active" and "ghost"
    path for each lun. IO's to the "ghost" path will never complete and the
    SCSI layer, via the scsi device handler rdac code, quick returns the IOs
    to theses paths and sets the REQ_QUIET scsi flag to suppress the scsi
    layer messages.
    
     I am wanting to extend the QUIET behavior to include the buffer file
    system layer to deal with these errors as well. I have been running this
    patch for a while now on several boxes without issue.  A few runs of
    bonnie++ show no noticeable difference in performance in my setup.
    
    Thanks for John Stultz for the quiet_error finalization.
    Submitted-by: default avatarKeith Mannthey <kmannth@us.ibm.com>
    Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
    08bafc03
blk-core.c 58 KB