Am 18.01.2012 15:59, schrieb Stefan Hajnoczi: > The qemu-img.c:is_not_zero() function checks if a buffer contains all > zeroes. This function will come in handy for zero-detection in the > block layer, so clean it up and move it to cutils.c. > > Note that the function now returns true if the buffer is all zeroes. > This avoids the double-negatives (i.e. !is_not_zero()) that the old > function can cause in callers. > > Signed-off-by: Stefan Hajnoczi <stefa...@linux.vnet.ibm.com> > --- > cutils.c | 34 ++++++++++++++++++++++++++++++++++ > qemu-common.h | 2 ++ > qemu-img.c | 46 +++++++--------------------------------------- > 3 files changed, 43 insertions(+), 39 deletions(-) > > diff --git a/cutils.c b/cutils.c > index a6ffd46..2ea9c3c 100644 > --- a/cutils.c > +++ b/cutils.c > @@ -303,6 +303,40 @@ void qemu_iovec_memset_skip(QEMUIOVector *qiov, int c, > size_t count, > } > } > > +/* > + * Checks if a buffer is all zeroes > + * > + * Attention! The len must be a multiple of 4 * sizeof(long) due to > + * restriction of optimizations in this function. > + */
Sounds like something to assert(), while you're touching the code. Kevin
