Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging

Block layer patches:

- Add block export infrastructure
- iotests improvements
- Document the throttle block filter
- Misc code cleanups

# gpg: Signature made Fri 02 Oct 2020 15:36:53 BST
# gpg:                using RSA key DC3DEB159A9AF95D3D7456FE7F09B272C88F2FD6
# gpg:                issuer "kwolf@redhat.com"
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>" [full]
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74  56FE 7F09 B272 C88F 2FD6

* remotes/kevin/tags/for-upstream: (37 commits)
  qcow2: Use L1E_SIZE in qcow2_write_l1_entry()
  qemu-storage-daemon: Fix help line for --export
  iotests: Test block-export-* QMP interface
  iotests: Allow supported and unsupported formats at the same time
  iotests: Introduce qemu_nbd_list_log()
  iotests: Factor out qemu_tool_pipe_and_status()
  nbd: Deprecate nbd-server-add/remove
  nbd: Merge nbd_export_new() and nbd_export_create()
  block/export: Move writable to BlockExportOptions
  block/export: Add query-block-exports
  block/export: Create BlockBackend in blk_exp_add()
  block/export: Move blk to BlockExport
  block/export: Add BLOCK_EXPORT_DELETED event
  block/export: Add block-export-del
  block/export: Move strong user reference to block_exports
  block/export: Add 'id' option to block-export-add
  block/export: Add blk_exp_close_all(_type)
  block/export: Allocate BlockExport in blk_exp_add()
  block/export: Add node-name to BlockExportOptions
  block/export: Move AioContext from NBDExport to BlockExport
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

2 files changed, 97 insertions, 14 deletions

diff --git a/include/block/export.h b/include/block/export.h
new file mode 100644
index 0000000..7feb02e
--- /dev/null
+++ b/include/block/export.h
@@ -0,0 +1,89 @@
+/*
+ * Declarations for block exports
+ *
+ * Copyright (c) 2012, 2020 Red Hat, Inc.
+ *
+ * Authors:
+ * Paolo Bonzini <pbonzini@redhat.com>
+ * Kevin Wolf <kwolf@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or
+ * later.  See the COPYING file in the top-level directory.
+ */
+
+#ifndef BLOCK_EXPORT_H
+#define BLOCK_EXPORT_H
+
+#include "qapi/qapi-types-block-export.h"
+#include "qemu/queue.h"
+
+typedef struct BlockExport BlockExport;
+
+typedef struct BlockExportDriver {
+    /* The export type that this driver services */
+    BlockExportType type;
+
+    /*
+     * The size of the driver-specific state that contains BlockExport as its
+     * first field.
+     */
+    size_t instance_size;
+
+    /* Creates and starts a new block export */
+    int (*create)(BlockExport *, BlockExportOptions *, Error **);
+
+    /*
+     * Frees a removed block export. This function is only called after all
+     * references have been dropped.
+     */
+    void (*delete)(BlockExport *);
+
+    /*
+     * Start to disconnect all clients and drop other references held
+     * internally by the export driver. When the function returns, there may
+     * still be active references while the export is in the process of
+     * shutting down.
+     */
+    void (*request_shutdown)(BlockExport *);
+} BlockExportDriver;
+
+struct BlockExport {
+    const BlockExportDriver *drv;
+
+    /* Unique identifier for the export */
+    char *id;
+
+    /*
+     * Reference count for this block export. This includes strong references
+     * both from the owner (qemu-nbd or the monitor) and clients connected to
+     * the export.
+     */
+    int refcount;
+
+    /*
+     * True if one of the references in refcount belongs to the user. After the
+     * user has dropped their reference, they may not e.g. remove the same
+     * export a second time (which would decrease the refcount without having
+     * it incremented first).
+     */
+    bool user_owned;
+
+    /* The AioContext whose lock protects this BlockExport object. */
+    AioContext *ctx;
+
+    /* The block device to export */
+    BlockBackend *blk;
+
+    /* List entry for block_exports */
+    QLIST_ENTRY(BlockExport) next;
+};
+
+BlockExport *blk_exp_add(BlockExportOptions *export, Error **errp);
+BlockExport *blk_exp_find(const char *id);
+void blk_exp_ref(BlockExport *exp);
+void blk_exp_unref(BlockExport *exp);
+void blk_exp_request_shutdown(BlockExport *exp);
+void blk_exp_close_all(void);
+void blk_exp_close_all_type(BlockExportType type);
+
+#endif
diff --git a/include/block/nbd.h b/include/block/nbd.h
index 9bc3bfa..3dd9a04 100644
--- a/include/block/nbd.h
+++ b/include/block/nbd.h
@@ -20,11 +20,13 @@
 #ifndef NBD_H
 #define NBD_H
 
-#include "qapi/qapi-types-block.h"
+#include "block/export.h"
 #include "io/channel-socket.h"
 #include "crypto/tlscreds.h"
 #include "qapi/error.h"
 
+extern const BlockExportDriver blk_exp_nbd;
+
 /* Handshake phase structs - this struct is passed on the wire */
 
 struct NBDOption {
@@ -328,21 +330,10 @@ int nbd_errno_to_system_errno(int err);
 typedef struct NBDExport NBDExport;
 typedef struct NBDClient NBDClient;
 
-NBDExport *nbd_export_new(BlockDriverState *bs, uint64_t dev_offset,
-                          uint64_t size, const char *name, const char *desc,
-                          const char *bitmap, bool readonly, bool shared,
-                          void (*close)(NBDExport *), bool writethrough,
-                          BlockBackend *on_eject_blk, Error **errp);
-void nbd_export_close(NBDExport *exp);
-void nbd_export_remove(NBDExport *exp, NbdServerRemoveMode mode, Error **errp);
-void nbd_export_get(NBDExport *exp);
-void nbd_export_put(NBDExport *exp);
-
-BlockBackend *nbd_export_get_blockdev(NBDExport *exp);
+void nbd_export_set_on_eject_blk(BlockExport *exp, BlockBackend *blk);
 
 AioContext *nbd_export_aio_context(NBDExport *exp);
 NBDExport *nbd_export_find(const char *name);
-void nbd_export_close_all(void);
 
 void nbd_client_new(QIOChannelSocket *sioc,
                     QCryptoTLSCreds *tlscreds,
@@ -351,8 +342,11 @@ void nbd_client_new(QIOChannelSocket *sioc,
 void nbd_client_get(NBDClient *client);
 void nbd_client_put(NBDClient *client);
 
+void nbd_server_is_qemu_nbd(bool value);
+bool nbd_server_is_running(void);
 void nbd_server_start(SocketAddress *addr, const char *tls_creds,
-                      const char *tls_authz, Error **errp);
+                      const char *tls_authz, uint32_t max_connections,
+                      Error **errp);
 void nbd_server_start_options(NbdServerOptions *arg, Error **errp);
 
 /* nbd_read