diff options
| -rw-r--r-- | lib/iov_iter.c | 42 |
1 files changed, 28 insertions, 14 deletions
diff --git a/lib/iov_iter.c b/lib/iov_iter.c index 03c4e677b075..cd23c79acb94 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -1096,28 +1096,42 @@ static void iov_iter_bvec_advance(struct iov_iter *i, size_t size) i->iov_offset = bi.bi_bvec_done; } +static void iov_iter_iovec_advance(struct iov_iter *i, size_t size) +{ + const struct iovec *iov, *end; + + if (!i->count) + return; + i->count -= size; + + size += i->iov_offset; // from beginning of current segment + for (iov = i->iov, end = iov + i->nr_segs; iov < end; iov++) { + if (likely(size < iov->iov_len)) + break; + size -= iov->iov_len; + } + i->iov_offset = size; + i->nr_segs -= iov - i->iov; + i->iov = iov; +} + void iov_iter_advance(struct iov_iter *i, size_t size) { if (unlikely(i->count < size)) size = i->count; - if (unlikely(iov_iter_is_pipe(i))) { + if (likely(iter_is_iovec(i) || iov_iter_is_kvec(i))) { + /* iovec and kvec have identical layouts */ + iov_iter_iovec_advance(i, size); + } else if (iov_iter_is_bvec(i)) { + iov_iter_bvec_advance(i, size); + } else if (iov_iter_is_pipe(i)) { pipe_advance(i, size); - return; - } - if (unlikely(iov_iter_is_discard(i))) { - i->count -= size; - return; - } - if (unlikely(iov_iter_is_xarray(i))) { + } else if (unlikely(iov_iter_is_xarray(i))) { i->iov_offset += size; i->count -= size; - return; - } - if (iov_iter_is_bvec(i)) { - iov_iter_bvec_advance(i, size); - return; + } else if (iov_iter_is_discard(i)) { + i->count -= size; } - iterate_and_advance(i, size, v, 0, 0, 0, 0) } EXPORT_SYMBOL(iov_iter_advance); |