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    SubjectRe: [PATCH] drivers: target: target_core_mod: use div64_u64_rem() instead of operator '%' for u64
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    Hi Chen,

    On Sat, 2013-12-21 at 10:08 +0800, Chen Gang wrote:
    > In kernel, need use div64_u64_rem() instead of operator '%' for u64, or
    > can not pass compiling (with allmodconfig under metag):
    >
    > MODPOST 2909 modules
    > ERROR: "__umoddi3" [drivers/target/target_core_mod.ko] undefined!
    >
    > Also need u64 type cast for u32 variable multiply u32 variable, or will
    > cause type overflow issue.
    >
    >
    > Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
    > ---
    > drivers/target/target_core_alua.c | 3 ++-
    > 1 file changed, 2 insertions(+), 1 deletion(-)
    >

    FYI, this unsigned long long division in core_alua_state_lba_dependent()
    was fixed for 32-bit in linux-next >= 12192013 code.

    Regardless, thanks for your patch.

    --nab

    > diff --git a/drivers/target/target_core_alua.c b/drivers/target/target_core_alua.c
    > index dc0d399..ff2aadc 100644
    > --- a/drivers/target/target_core_alua.c
    > +++ b/drivers/target/target_core_alua.c
    > @@ -489,7 +489,8 @@ static inline int core_alua_state_lba_dependent(
    > u64 first_lba = map->lba_map_first_lba;
    >
    > if (segment_mult) {
    > - start_lba = lba % (segment_size * segment_mult);
    > + u64 tmp = (u64)segment_size * segment_mult;
    > + div64_u64_rem(lba, tmp, &start_lba);
    > last_lba = first_lba + segment_size - 1;
    > if (start_lba >= first_lba &&
    > start_lba <= last_lba) {




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