Merge PR ceph#54808 into main

* refs/pull/54808/head:
	client: fix copying bufferlist to iovec structures in Client::_read
	src/test: test sync call providing nullptr as ctx to async api

Reviewed-by: Venky Shankar <[email protected]>
Reviewed-by: Milind Changire <[email protected]>
Reviewed-by: Frank S. Filz <[email protected]>

Author: vshankar

.githubmap

@@ -176,3 +176,4 @@ baergj Joshua Baergen <[email protected]>
 zmc Zack Cerza <[email protected]>
 robbat2 Robin H. Johnson <[email protected]>
 leonid-s-usov Leonid Usov <[email protected]>
+ffilz Frank S. Filz <[email protected]>

src/client/Client.cc

@@ -11269,7 +11269,7 @@ int64_t Client::_preadv_pwritev_locked(Fh *fh, const struct iovec *iov,
         }
 
         client_lock.unlock();
-        copy_bufferlist_to_iovec(iov, iovcnt, &bl, r);
+        copy_bufferlist_to_iovec(iov, iovcnt, blp ? blp : &bl, r);
         client_lock.lock();
         return r;
     }

src/test/client/nonblocking.cc

@@ -149,3 +149,62 @@ TEST_F(TestClient, LlreadvLlwritev) {
   ASSERT_EQ(0, client->ll_unlink(root, filename, myperm));
 }
 
+TEST_F(TestClient, LlreadvLlwritevNullContext) {
+  /* Test that if Client::ll_preadv_pwritev is called with nullptr context
+  then it performs a sync call. */
+
+  int mypid = getpid();
+  char filename[256];
+
+  client->unmount();
+  TearDown();
+  SetUp();
+
+  sprintf(filename, "test_llreadvllwritevnullcontextfile%u", mypid);
+
+  Inode *root, *file;
+  root = client->get_root();
+  ASSERT_NE(root, (Inode *)NULL);
+
+  Fh *fh;
+  struct ceph_statx stx;
+
+  ASSERT_EQ(0, client->ll_createx(root, filename, 0666,
+				  O_RDWR | O_CREAT | O_TRUNC,
+				  &file, &fh, &stx, 0, 0, myperm));
+
+  char out0[] = "hello ";
+  char out1[] = "world\n";  
+  struct iovec iov_out[2] = {
+	  {out0, sizeof(out0)},
+	  {out1, sizeof(out1)}
+  };
+
+  char in0[sizeof(out0)];
+  char in1[sizeof(out1)];
+  struct iovec iov_in[2] = {
+	  {in0, sizeof(in0)},
+	  {in1, sizeof(in1)}
+  };
+
+  ssize_t bytes_to_write = iov_out[0].iov_len + iov_out[1].iov_len;
+
+  int64_t rc;
+  bufferlist bl;
+  rc = client->ll_preadv_pwritev(fh, iov_out, 2, 0, true, nullptr, nullptr);
+  ASSERT_EQ(rc, bytes_to_write);
+
+  rc = client->ll_preadv_pwritev(fh, iov_in, 2, 0, false, nullptr, &bl);
+  ASSERT_EQ(rc, bytes_to_write);
+
+  copy_bufferlist_to_iovec(iov_in, 2, &bl, rc);
+  ASSERT_EQ(0, strncmp((const char*)iov_in[0].iov_base,
+                       (const char*)iov_out[0].iov_base,
+                       iov_out[0].iov_len));
+  ASSERT_EQ(0, strncmp((const char*)iov_in[1].iov_base,
+                       (const char*)iov_out[1].iov_base, 
+                       iov_out[1].iov_len));
+
+  client->ll_release(fh);
+  ASSERT_EQ(0, client->ll_unlink(root, filename, myperm));
+}