diff options
Diffstat (limited to 'net/9p/trans_virtio.c')
| -rw-r--r-- | net/9p/trans_virtio.c | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c index 147972bf2e79..03770addaa5c 100644 --- a/net/9p/trans_virtio.c +++ b/net/9p/trans_virtio.c @@ -377,6 +377,35 @@ static int p9_get_mapped_pages(struct virtio_chan *chan, } } +static void handle_rerror(struct p9_req_t *req, int in_hdr_len, + size_t offs, struct page **pages) +{ + unsigned size, n; + void *to = req->rc.sdata + in_hdr_len; + + // Fits entirely into the static data? Nothing to do. + if (req->rc.size < in_hdr_len) + return; + + // Really long error message? Tough, truncate the reply. Might get + // rejected (we can't be arsed to adjust the size encoded in header, + // or string size for that matter), but it wouldn't be anything valid + // anyway. + if (unlikely(req->rc.size > P9_ZC_HDR_SZ)) + req->rc.size = P9_ZC_HDR_SZ; + + // data won't span more than two pages + size = req->rc.size - in_hdr_len; + n = PAGE_SIZE - offs; + if (size > n) { + memcpy_from_page(to, *pages++, offs, n); + offs = 0; + to += n; + size -= n; + } + memcpy_from_page(to, *pages, offs, size); +} + /** * p9_virtio_zc_request - issue a zero copy request * @client: client instance issuing the request @@ -503,6 +532,11 @@ req_retry_pinned: kicked = 1; p9_debug(P9_DEBUG_TRANS, "virtio request kicked\n"); err = wait_event_killable(req->wq, req->status >= REQ_STATUS_RCVD); + // RERROR needs reply (== error string) in static data + if (req->status == REQ_STATUS_RCVD && + unlikely(req->rc.sdata[4] == P9_RERROR)) + handle_rerror(req, in_hdr_len, offs, in_pages); + /* * Non kernel buffers are pinned, unpin them */ |