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    dm raid1: set discard_zeroes_data_unsupported · 7c8d3a42
    Mikulas Patocka 提交于
    We can't guarantee that REQ_DISCARD on dm-mirror zeroes the data even if
    the underlying disks support zero on discard.  So this patch sets
    ti->discard_zeroes_data_unsupported.
    
    For example, if the mirror is in the process of resynchronizing, it may
    happen that kcopyd reads a piece of data, then discard is sent on the
    same area and then kcopyd writes the piece of data to another leg.
    Consequently, the data is not zeroed.
    
    The flag was made available by commit 983c7db3
    (dm crypt: always disable discard_zeroes_data).
    Signed-off-by: NMikulas Patocka <mpatocka@redhat.com>
    Cc: stable@kernel.org
    Signed-off-by: NAlasdair G Kergon <agk@redhat.com>
    7c8d3a42
dm-raid1.c 34.2 KB