osdc/Objecter: invalidate crcs on preallocated rx buffers

Both simple and async messengers use c_str() when copying the data from
the socket into the receive buffer, going behind bufferlist's back.  If
the receive buffer is preallocated, we need to invalidate its crc cache
by hand to avoid possible data crc mismatches on the client side.

Fixes: https://tracker.ceph.com/issues/38416
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
(cherry picked from commit 3eeab975b604d9fc4290747f85a78d59a2452c2e)

Conflicts:
	src/test/librados/io_cxx.cc
- In master, 3730d10623650ce8569be96b28cbba599a9a0db6 renamed this file from
  src/test/librados/io.cc but that commit is not being backported to luminous.
  Manually cherry-picked the test mods into src/test/librados/io.cc.

diff --git a/src/osdc/Objecter.cc b/src/osdc/Objecter.cc
index 447f44f6256b6fbbc59b26bb7965ad63e5c050c5..ac204c7cd430d22580632746a52df8b6ba8d749e 100644 (file)
--- a/src/osdc/Objecter.cc
+++ b/src/osdc/Objecter.cc
@@ -3269,6 +3269,7 @@ void Objecter::_send_op(Op *op, MOSDOp *m)
   if (op->outbl &&
       op->ontimeout == 0 &&  // only post rx_buffer if no timeout; see #9582
       op->outbl->length()) {
+    op->outbl->invalidate_crc();  // messenger writes through c_str()
     ldout(cct, 20) << " posting rx buffer for " << op->tid << " on " << con
                   << dendl;
     op->con = con;

diff --git a/src/test/librados/io.cc b/src/test/librados/io.cc
index 5094f756987af0c29a89650802b14e3881eb57a8..ae8b0da252a9a51498d54b1210d23e3a6a889bbc 100644 (file)
--- a/src/test/librados/io.cc
+++ b/src/test/librados/io.cc
@@ -235,6 +235,21 @@ TEST_F(LibRadosIoPP, ReadOpPP) {
       ASSERT_EQ(0, memcmp(read_bl1.c_str(), buf, sizeof(buf)));
       ASSERT_EQ(0, memcmp(read_bl2.c_str(), buf, sizeof(buf)));
   }
+
+  // read into a preallocated buffer with a cached crc
+  {
+      bufferlist op_bl;
+      op_bl.append(std::string(sizeof(buf), 'x'));
+      ASSERT_NE(op_bl.crc32c(0), bl.crc32c(0));  // cache 'x' crc
+
+      ObjectReadOperation op;
+      op.read(0, sizeof(buf), NULL, NULL);
+      ASSERT_EQ(0, ioctx.operate("foo", &op, &op_bl));
+
+      ASSERT_EQ(sizeof(buf), op_bl.length());
+      ASSERT_EQ(0, memcmp(op_bl.c_str(), buf, sizeof(buf)));
+      ASSERT_EQ(op_bl.crc32c(0), bl.crc32c(0));
+  }
 }
 
 TEST_F(LibRadosIoPP, SparseReadOpPP) {
@@ -799,6 +814,21 @@ TEST_F(LibRadosIoECPP, ReadOpPP) {
       ASSERT_EQ(0, memcmp(read_bl1.c_str(), buf, sizeof(buf)));
       ASSERT_EQ(0, memcmp(read_bl2.c_str(), buf, sizeof(buf)));
   }
+
+  // read into a preallocated buffer with a cached crc
+  {
+      bufferlist op_bl;
+      op_bl.append(std::string(sizeof(buf), 'x'));
+      ASSERT_NE(op_bl.crc32c(0), bl.crc32c(0));  // cache 'x' crc
+
+      ObjectReadOperation op;
+      op.read(0, sizeof(buf), NULL, NULL);
+      ASSERT_EQ(0, ioctx.operate("foo", &op, &op_bl));
+
+      ASSERT_EQ(sizeof(buf), op_bl.length());
+      ASSERT_EQ(0, memcmp(op_bl.c_str(), buf, sizeof(buf)));
+      ASSERT_EQ(op_bl.crc32c(0), bl.crc32c(0));
+  }
 }
 
 TEST_F(LibRadosIoECPP, SparseReadOpPP) {