summary refs log tree commit diff stats
path: root/nbd/common.c
diff options
context:
space:
mode:
Diffstat (limited to 'nbd/common.c')
-rw-r--r--nbd/common.c64
1 files changed, 64 insertions, 0 deletions
diff --git a/nbd/common.c b/nbd/common.c
new file mode 100644
index 0000000000..7b089b0f3b
--- /dev/null
+++ b/nbd/common.c
@@ -0,0 +1,64 @@
+/*
+ *  Copyright (C) 2005  Anthony Liguori <anthony@codemonkey.ws>
+ *
+ *  Network Block Device Common Code
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; under version 2 of the License.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "nbd-internal.h"
+
+ssize_t nbd_wr_sync(int fd, void *buffer, size_t size, bool do_read)
+{
+    size_t offset = 0;
+    int err;
+
+    if (qemu_in_coroutine()) {
+        if (do_read) {
+            return qemu_co_recv(fd, buffer, size);
+        } else {
+            return qemu_co_send(fd, buffer, size);
+        }
+    }
+
+    while (offset < size) {
+        ssize_t len;
+
+        if (do_read) {
+            len = qemu_recv(fd, buffer + offset, size - offset, 0);
+        } else {
+            len = send(fd, buffer + offset, size - offset, 0);
+        }
+
+        if (len < 0) {
+            err = socket_error();
+
+            /* recoverable error */
+            if (err == EINTR || (offset > 0 && (err == EAGAIN || err == EWOULDBLOCK))) {
+                continue;
+            }
+
+            /* unrecoverable error */
+            return -err;
+        }
+
+        /* eof */
+        if (len == 0) {
+            break;
+        }
+
+        offset += len;
+    }
+
+    return offset;
+}