• Mike Snitzer's avatar
    dm: don't use bio_trim() afterall · fa8db494
    Mike Snitzer authored
    bio_trim() has an early return, which makes it _not_ idempotent, if the
    offset is 0 and the bio's bi_size already matches the requested size.
    Prior to DM, all users of bio_trim() were fine with this.  But DM has
    exposed the fact that bio_trim()'s early return is incompatible with a
    cloned bio whose integrity payload must be trimmed via
    bio_integrity_trim().
    
    Fix this by reverting DM back to doing the equivalent of bio_trim() but
    in an idempotent manner (so bio_integrity_trim is always performed).
    
    Follow-on work is needed to assess what benefit bio_trim()'s early
    return is providing to its existing callers.
    Reported-by: default avatarMilan Broz <gmazyland@gmail.com>
    Fixes: 57c36519 ("dm: fix clone_bio() to trigger blk_recount_segments()")
    Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
    fa8db494
dm.c 73.8 KB