radosgw: fix small sized chunked uploads with s3

The logic to compute the number of bytes to copy with a chunked file
upload was failing to take into account the amount of data that had been
consumed, but was still pending in the parse buffer.  This would cause
strange behavior ranging from "just works" to "fails".  There was also a
strange "works, one byte at a time" mode.  Using the correct stream_pos
offset eliminates the bad behavior.

This fix also adds debug statements to make the correct behavior easier to see.

Fixes: http://tracker.ceph.com/issues/21003
Signed-off-by: Marcus Watts <mwatts@redhat.com>

diff --git a/src/rgw/rgw_auth_s3.cc b/src/rgw/rgw_auth_s3.cc
index e183465b95c2ffec7b1c859a911496881b624339..ba137e3f59b509656f6d3318da4a85fc993d3ba0 100644 (file)
--- a/src/rgw/rgw_auth_s3.cc
+++ b/src/rgw/rgw_auth_s3.cc
@@ -993,8 +993,11 @@ size_t AWSv4ComplMulti::recv_body(char* const buf, const size_t buf_max)
                       std::begin(parsing_buf) + consumed);
   }
 
+  size_t stream_pos_was = stream_pos - parsing_buf.size();
+
   size_t to_extract = \
-    std::min(chunk_meta.get_data_size(stream_pos), buf_max);
+    std::min(chunk_meta.get_data_size(stream_pos_was), buf_max);
+  dout(30) << "AWSv4ComplMulti: stream_pos_was=" << stream_pos_was << ", to_extract=" << to_extract << dendl;
   
   /* It's quite probable we have a couple of real data bytes stored together
    * with meta-data in the parsing_buf. We need to extract them and move to
@@ -1003,6 +1006,7 @@ size_t AWSv4ComplMulti::recv_body(char* const buf, const size_t buf_max)
   if (to_extract > 0 && parsing_buf.size() > 0) {
     const auto data_len = std::min(to_extract, parsing_buf.size());
     const auto data_end_iter = std::begin(parsing_buf) + data_len;
+    dout(30) << "AWSv4ComplMulti: to_extract=" << to_extract << ", data_len=" << data_len << dendl;
 
     std::copy(std::begin(parsing_buf), data_end_iter, buf);
     parsing_buf.erase(std::begin(parsing_buf), data_end_iter);
@@ -1017,6 +1021,7 @@ size_t AWSv4ComplMulti::recv_body(char* const buf, const size_t buf_max)
    * buffering. */
   while (to_extract > 0) {
     const size_t received = io_base_t::recv_body(buf + buf_pos, to_extract);
+    dout(30) << "AWSv4ComplMulti: to_extract=" << to_extract << ", received=" << received << dendl;
 
     if (received == 0) {
       break;