bvec/iter: disallow zero-length segment bvecs
zero-length bvec segments are allowed in general, but not handled by bio
and down the block layer so filtered out. This inconsistency may be
confusing and prevent from optimisations. As zero-length segments are
useless and places that were generating them are patched, declare them
not allowed.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/Documentation/block/biovecs.rst b/Documentation/block/biovecs.rst
index 36771a1..ddb867e0 100644
--- a/Documentation/block/biovecs.rst
+++ b/Documentation/block/biovecs.rst
@@ -40,6 +40,8 @@
There is a lower level advance function - bvec_iter_advance() - which takes
a pointer to a biovec, not a bio; this is used by the bio integrity code.
+As of 5.12 bvec segments with zero bv_len are not supported.
+
What's all this get us?
=======================
