diff options
| -rw-r--r-- | include/linux/bvec.h | 32 |
1 files changed, 21 insertions, 11 deletions
diff --git a/include/linux/bvec.h b/include/linux/bvec.h index fe7a22dd133b..843d434df4e8 100644 --- a/include/linux/bvec.h +++ b/include/linux/bvec.h @@ -72,26 +72,36 @@ struct bvec_iter { static inline bool bvec_iter_advance(const struct bio_vec *bv, struct bvec_iter *iter, unsigned bytes) { + unsigned bvec_len; + if (WARN_ONCE(bytes > iter->bi_size, "Attempted to advance past end of bvec iter\n")) { iter->bi_size = 0; return false; } - while (bytes) { - unsigned iter_len = bvec_iter_len(bv, *iter); - unsigned len = min(bytes, iter_len); + iter->bi_size -= bytes; + iter->bi_done += bytes; - bytes -= len; - iter->bi_size -= len; - iter->bi_bvec_done += len; - iter->bi_done += len; + bv += iter->bi_idx; - if (iter->bi_bvec_done == __bvec_iter_bvec(bv, *iter)->bv_len) { - iter->bi_bvec_done = 0; - iter->bi_idx++; - } + while (1) { + /* don't deref bv when bytes == 0: */ + if (!bytes) + break; + + bvec_len = bv->bv_len - iter->bi_bvec_done; + if (bytes < bvec_len) + break; + + bytes -= bvec_len; + + iter->bi_bvec_done = 0; + iter->bi_idx++; + bv++; } + + iter->bi_bvec_done += bytes; return true; } |