From: Sagi Grimberg sagi@grimberg.me
commit ca1ff67d0fb14f39cf0cc5102b1fbcc3b14f6fb9 upstream.
When a bio merges, we can get a request that spans multiple bios, and the overall request payload size is the sum of all bios. When we calculate how much we need to send from the existing bio (and bvec), we did not take into account the iov_iter byte count cap.
Since multipage bvecs support, bvecs can split in the middle which means that when we account for the last bvec send we should also take the iov_iter byte count cap as it might be lower than the last bvec size.
Reported-by: Hao Wang pkuwangh@gmail.com Fixes: 3f2304f8c6d6 ("nvme-tcp: add NVMe over TCP host driver") Tested-by: Hao Wang pkuwangh@gmail.com Signed-off-by: Sagi Grimberg sagi@grimberg.me Signed-off-by: Christoph Hellwig hch@lst.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/nvme/host/tcp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/nvme/host/tcp.c +++ b/drivers/nvme/host/tcp.c @@ -201,7 +201,7 @@ static inline size_t nvme_tcp_req_cur_of
static inline size_t nvme_tcp_req_cur_length(struct nvme_tcp_request *req) { - return min_t(size_t, req->iter.bvec->bv_len - req->iter.iov_offset, + return min_t(size_t, iov_iter_single_seg_count(&req->iter), req->pdu_len - req->pdu_sent); }