nbd: add errp to read_sync, write_sync and drop_sync

[qemu.git] / nbd / client.c

diff --git a/nbd/client.c b/nbd/client.c
index 7db4301d292949e9a2cb215cd43a93377efa52df..f1023755045834c4f6b4a3a317b05fe1f692064f 100644 (file)
--- a/nbd/client.c
+++ b/nbd/client.c
@@ -86,24 +86,24 @@ static QTAILQ_HEAD(, NBDExport) exports = QTAILQ_HEAD_INITIALIZER(exports);
 
 */
 
-/* Discard length bytes from channel.  Return -errno on failure, or
- * the amount of bytes consumed. */
-static ssize_t drop_sync(QIOChannel *ioc, size_t size)
+/* Discard length bytes from channel.  Return -errno on failure and 0 on
+ * success*/
+static int drop_sync(QIOChannel *ioc, size_t size, Error **errp)
 {
-    ssize_t ret, dropped = size;
+    ssize_t ret = 0;
     char small[1024];
     char *buffer;
 
-    buffer = sizeof(small) < size ? small : g_malloc(MIN(65536, size));
+    buffer = sizeof(small) >= size ? small : g_malloc(MIN(65536, size));
     while (size > 0) {
-        ret = read_sync(ioc, buffer, MIN(65536, size));
+        ssize_t count = MIN(65536, size);
+        ret = read_sync(ioc, buffer, MIN(65536, size), errp);
+
         if (ret < 0) {
             goto cleanup;
         }
-        assert(ret <= size);
-        size -= ret;
+        size -= count;
     }
-    ret = dropped;
 
  cleanup:
     if (buffer != small) {
@@ -135,13 +135,13 @@ static int nbd_send_option_request(QIOChannel *ioc, uint32_t opt,
     stl_be_p(&req.option, opt);
     stl_be_p(&req.length, len);
 
-    if (write_sync(ioc, &req, sizeof(req)) != sizeof(req)) {
-        error_setg(errp, "Failed to send option request header");
+    if (write_sync(ioc, &req, sizeof(req), errp) < 0) {
+        error_prepend(errp, "Failed to send option request header");
         return -1;
     }
 
-    if (len && write_sync(ioc, (char *) data, len) != len) {
-        error_setg(errp, "Failed to send option request data");
+    if (len && write_sync(ioc, (char *) data, len, errp) < 0) {
+        error_prepend(errp, "Failed to send option request data");
         return -1;
     }
 
@@ -169,8 +169,8 @@ static int nbd_receive_option_reply(QIOChannel *ioc, uint32_t opt,
                                     nbd_opt_reply *reply, Error **errp)
 {
     QEMU_BUILD_BUG_ON(sizeof(*reply) != 20);
-    if (read_sync(ioc, reply, sizeof(*reply)) != sizeof(*reply)) {
-        error_setg(errp, "failed to read option reply");
+    if (read_sync(ioc, reply, sizeof(*reply), errp) < 0) {
+        error_prepend(errp, "failed to read option reply");
         nbd_send_opt_abort(ioc);
         return -1;
     }
@@ -218,8 +218,8 @@ static int nbd_handle_reply_err(QIOChannel *ioc, nbd_opt_reply *reply,
             goto cleanup;
         }
         msg = g_malloc(reply->length + 1);
-        if (read_sync(ioc, msg, reply->length) != reply->length) {
-            error_setg(errp, "failed to read option error message");
+        if (read_sync(ioc, msg, reply->length, errp) < 0) {
+            error_prepend(errp, "failed to read option error message");
             goto cleanup;
         }
         msg[reply->length] = '\0';
@@ -320,8 +320,8 @@ static int nbd_receive_list(QIOChannel *ioc, const char *want, bool *match,
         nbd_send_opt_abort(ioc);
         return -1;
     }
-    if (read_sync(ioc, &namelen, sizeof(namelen)) != sizeof(namelen)) {
-        error_setg(errp, "failed to read option name length");
+    if (read_sync(ioc, &namelen, sizeof(namelen), errp) < 0) {
+        error_prepend(errp, "failed to read option name length");
         nbd_send_opt_abort(ioc);
         return -1;
     }
@@ -333,8 +333,8 @@ static int nbd_receive_list(QIOChannel *ioc, const char *want, bool *match,
         return -1;
     }
     if (namelen != strlen(want)) {
-        if (drop_sync(ioc, len) != len) {
-            error_setg(errp, "failed to skip export name with wrong length");
+        if (drop_sync(ioc, len, errp) < 0) {
+            error_prepend(errp, "failed to skip export name with wrong length");
             nbd_send_opt_abort(ioc);
             return -1;
         }
@@ -342,15 +342,15 @@ static int nbd_receive_list(QIOChannel *ioc, const char *want, bool *match,
     }
 
     assert(namelen < sizeof(name));
-    if (read_sync(ioc, name, namelen) != namelen) {
-        error_setg(errp, "failed to read export name");
+    if (read_sync(ioc, name, namelen, errp) < 0) {
+        error_prepend(errp, "failed to read export name");
         nbd_send_opt_abort(ioc);
         return -1;
     }
     name[namelen] = '\0';
     len -= namelen;
-    if (drop_sync(ioc, len) != len) {
-        error_setg(errp, "failed to read export description");
+    if (drop_sync(ioc, len, errp) < 0) {
+        error_prepend(errp, "failed to read export description");
         nbd_send_opt_abort(ioc);
         return -1;
     }
@@ -476,8 +476,8 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint16_t *flags,
         goto fail;
     }
 
-    if (read_sync(ioc, buf, 8) != 8) {
-        error_setg(errp, "Failed to read data");
+    if (read_sync(ioc, buf, 8, errp) < 0) {
+        error_prepend(errp, "Failed to read data");
         goto fail;
     }
 
@@ -502,8 +502,8 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint16_t *flags,
         goto fail;
     }
 
-    if (read_sync(ioc, &magic, sizeof(magic)) != sizeof(magic)) {
-        error_setg(errp, "Failed to read magic");
+    if (read_sync(ioc, &magic, sizeof(magic), errp) < 0) {
+        error_prepend(errp, "Failed to read magic");
         goto fail;
     }
     magic = be64_to_cpu(magic);
@@ -514,9 +514,8 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint16_t *flags,
         uint16_t globalflags;
         bool fixedNewStyle = false;
 
-        if (read_sync(ioc, &globalflags, sizeof(globalflags)) !=
-            sizeof(globalflags)) {
-            error_setg(errp, "Failed to read server flags");
+        if (read_sync(ioc, &globalflags, sizeof(globalflags), errp) < 0) {
+            error_prepend(errp, "Failed to read server flags");
             goto fail;
         }
         globalflags = be16_to_cpu(globalflags);
@@ -533,9 +532,8 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint16_t *flags,
         }
         /* client requested flags */
         clientflags = cpu_to_be32(clientflags);
-        if (write_sync(ioc, &clientflags, sizeof(clientflags)) !=
-            sizeof(clientflags)) {
-            error_setg(errp, "Failed to send clientflags field");
+        if (write_sync(ioc, &clientflags, sizeof(clientflags), errp) < 0) {
+            error_prepend(errp, "Failed to send clientflags field");
             goto fail;
         }
         if (tlscreds) {
@@ -572,14 +570,14 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint16_t *flags,
         }
 
         /* Read the response */
-        if (read_sync(ioc, &s, sizeof(s)) != sizeof(s)) {
-            error_setg(errp, "Failed to read export length");
+        if (read_sync(ioc, &s, sizeof(s), errp) < 0) {
+            error_prepend(errp, "Failed to read export length");
             goto fail;
         }
         *size = be64_to_cpu(s);
 
-        if (read_sync(ioc, flags, sizeof(*flags)) != sizeof(*flags)) {
-            error_setg(errp, "Failed to read export flags");
+        if (read_sync(ioc, flags, sizeof(*flags), errp) < 0) {
+            error_prepend(errp, "Failed to read export flags");
             goto fail;
         }
         be16_to_cpus(flags);
@@ -595,15 +593,15 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint16_t *flags,
             goto fail;
         }
 
-        if (read_sync(ioc, &s, sizeof(s)) != sizeof(s)) {
-            error_setg(errp, "Failed to read export length");
+        if (read_sync(ioc, &s, sizeof(s), errp) < 0) {
+            error_prepend(errp, "Failed to read export length");
             goto fail;
         }
         *size = be64_to_cpu(s);
         TRACE("Size is %" PRIu64, *size);
 
-        if (read_sync(ioc, &oldflags, sizeof(oldflags)) != sizeof(oldflags)) {
-            error_setg(errp, "Failed to read export flags");
+        if (read_sync(ioc, &oldflags, sizeof(oldflags), errp) < 0) {
+            error_prepend(errp, "Failed to read export flags");
             goto fail;
         }
         be32_to_cpus(&oldflags);
@@ -618,8 +616,8 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint16_t *flags,
     }
 
     TRACE("Size is %" PRIu64 ", export flags %" PRIx16, *size, *flags);
-    if (zeroes && drop_sync(ioc, 124) != 124) {
-        error_setg(errp, "Failed to read reserved block");
+    if (zeroes && drop_sync(ioc, 124, errp) < 0) {
+        error_prepend(errp, "Failed to read reserved block");
         goto fail;
     }
     rc = 0;
@@ -743,7 +741,6 @@ int nbd_disconnect(int fd)
 ssize_t nbd_send_request(QIOChannel *ioc, NBDRequest *request)
 {
     uint8_t buf[NBD_REQUEST_SIZE];
-    ssize_t ret;
 
     TRACE("Sending request to server: "
           "{ .from = %" PRIu64", .len = %" PRIu32 ", .handle = %" PRIu64
@@ -758,16 +755,7 @@ ssize_t nbd_send_request(QIOChannel *ioc, NBDRequest *request)
     stq_be_p(buf + 16, request->from);
     stl_be_p(buf + 24, request->len);
 
-    ret = write_sync(ioc, buf, sizeof(buf));
-    if (ret < 0) {
-        return ret;
-    }
-
-    if (ret != sizeof(buf)) {
-        LOG("writing to socket failed");
-        return -EINVAL;
-    }
-    return 0;
+    return write_sync(ioc, buf, sizeof(buf), NULL);
 }
 
 ssize_t nbd_receive_reply(QIOChannel *ioc, NBDReply *reply)
@@ -776,8 +764,8 @@ ssize_t nbd_receive_reply(QIOChannel *ioc, NBDReply *reply)
     uint32_t magic;
     ssize_t ret;
 
-    ret = read_sync(ioc, buf, sizeof(buf));
-    if (ret < 0) {
+    ret = read_sync_eof(ioc, buf, sizeof(buf), NULL);
+    if (ret <= 0) {
         return ret;
     }
 
@@ -811,6 +799,6 @@ ssize_t nbd_receive_reply(QIOChannel *ioc, NBDReply *reply)
         LOG("invalid magic (got 0x%" PRIx32 ")", magic);
         return -EINVAL;
     }
-    return 0;
+    return sizeof(buf);
 }