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    block: make sure that bvec length can't be overflow · 6bedf00e
    Ming Lei 提交于
    bvec->bv_offset may be bigger than PAGE_SIZE sometimes, such as,
    when one bio is splitted in the middle of one bvec via bio_split(),
    and bi_iter.bi_bvec_done is used to build offset of the 1st bvec of
    remained bio. And the remained bio's bvec may be re-submitted to fs
    layer via ITER_IBVEC, such as loop and nvme-loop.
    
    So we have to make sure that every bvec's offset is less than
    PAGE_SIZE from bio_for_each_segment_all() because some drivers(loop,
    nvme-loop) passes the splitted bvec to fs layer via ITER_BVEC.
    
    This patch fixes this issue reported by Zhang Yi When running nvme/011.
    
    Cc: Christoph Hellwig <hch@lst.de>
    Cc: Yi Zhang <yi.zhang@redhat.com>
    Reported-by: NYi Zhang <yi.zhang@redhat.com>
    Reviewed-by: NChristoph Hellwig <hch@lst.de>
    Fixes: 6dc4f100 ("block: allow bio_for_each_segment_all() to iterate over multi-page bvec")
    Signed-off-by: NMing Lei <ming.lei@redhat.com>
    Signed-off-by: NJens Axboe <axboe@kernel.dk>
    6bedf00e
bvec.h 5.5 KB