The basic version of pcache driver for easy preparation of a patch set.
Signed-off-by: Pavel Butsykin <pbutsy...@virtuozzo.com>
---
block/Makefile.objs | 1 +
block/pcache.c | 144 ++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 145 insertions(+)
create mode 100644 block/pcache.c
diff --git a/block/Makefile.objs b/block/Makefile.objs
index 7d4031d..c60f680 100644
--- a/block/Makefile.objs
+++ b/block/Makefile.objs
@@ -4,6 +4,7 @@ block-obj-y += qed.o qed-gencb.o qed-l2-cache.o qed-table.o
qed-cluster.o
block-obj-y += qed-check.o
block-obj-y += vhdx.o vhdx-endian.o vhdx-log.o
block-obj-y += quorum.o
+block-obj-y += pcache.o
block-obj-y += parallels.o blkdebug.o blkverify.o blkreplay.o
block-obj-y += block-backend.o snapshot.o qapi.o
block-obj-$(CONFIG_WIN32) += raw-win32.o win32-aio.o
diff --git a/block/pcache.c b/block/pcache.c
new file mode 100644
index 0000000..59461df
--- /dev/null
+++ b/block/pcache.c
@@ -0,0 +1,144 @@
+/*
+ * Prefetch cache driver filter
+ *
+ * Copyright (C) 2015-2016 Parallels IP Holdings GmbH. All rights reserved.
+ *
+ * Author: Pavel Butsykin <pbutsy...@virtuozzo.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.
+ */
+
+#include "qemu/osdep.h"
+#include "block/block_int.h"
+#include "qapi/error.h"
+#include "qapi/qmp/qstring.h"
+
+
+static QemuOptsList runtime_opts = {
+ .name = "pcache",
+ .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
+ .desc = {
+ {
+ .name = "x-image",
+ .type = QEMU_OPT_STRING,
+ .help = "[internal use only, will be removed]",
+ },
+ { /* end of list */ }
+ },
+};
+
+typedef struct PCacheAIOCB {
+ Coroutine *co;
+ int ret;
+} PCacheAIOCB;
+
+static void pcache_aio_cb(void *opaque, int ret)
+{
+ PCacheAIOCB *acb = opaque;
+
+ acb->ret = ret;
+ qemu_coroutine_enter(acb->co);
+}
+
+static coroutine_fn int pcache_co_preadv(BlockDriverState *bs, uint64_t offset,
+ uint64_t bytes, QEMUIOVector *qiov,
+ int flags)
+{
+ PCacheAIOCB acb = {
+ .co = qemu_coroutine_self(),
+ };
+
+ bdrv_aio_preadv(bs->file, offset, qiov, bytes, pcache_aio_cb, &acb);
+
+ qemu_coroutine_yield();
+
+ return acb.ret;
+}
+
+static coroutine_fn int pcache_co_pwritev(BlockDriverState *bs, uint64_t
offset,
+ uint64_t bytes, QEMUIOVector *qiov,
+ int flags)
+{
+ PCacheAIOCB acb = {
+ .co = qemu_coroutine_self(),
+ };
+
+ bdrv_aio_pwritev(bs->file, offset, qiov, bytes, pcache_aio_cb, &acb);
+
+ qemu_coroutine_yield();
+
+ return acb.ret;
+}
+
+static int pcache_file_open(BlockDriverState *bs, QDict *options, int flags,
+ Error **errp)
+{
+ QemuOpts *opts;
+ Error *local_err = NULL;
+ int ret = 0;
+
+ opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
+ qemu_opts_absorb_qdict(opts, options, &local_err);
+ if (local_err) {
+ error_propagate(errp, local_err);
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ assert(bs->file == NULL);
+ bs->file = bdrv_open_child(qemu_opt_get(opts, "x-image"), options,
+ "image", bs, &child_format, false, &local_err);
+ if (local_err) {
+ ret = -EINVAL;
+ error_propagate(errp, local_err);
+ }
+fail:
+ qemu_opts_del(opts);
+ return ret;
+}
+
+static void pcache_close(BlockDriverState *bs)
+{
+}
+
+static void pcache_parse_filename(const char *filename, QDict *options,
+ Error **errp)
+{
+ qdict_put(options, "x-image", qstring_from_str(filename));
+}
+
+static int64_t pcache_getlength(BlockDriverState *bs)
+{
+ return bdrv_getlength(bs->file->bs);
+}
+
+static bool pcache_recurse_is_first_non_filter(BlockDriverState *bs,
+ BlockDriverState *candidate)
+{
+ return bdrv_recurse_is_first_non_filter(bs->file->bs, candidate);
+}
+
+static BlockDriver bdrv_pcache = {
+ .format_name = "pcache",
+ .protocol_name = "pcache",
+ .instance_size = 0,
+
+ .bdrv_parse_filename = pcache_parse_filename,
+ .bdrv_file_open = pcache_file_open,
+ .bdrv_close = pcache_close,
+ .bdrv_getlength = pcache_getlength,
+
+ .bdrv_co_preadv = pcache_co_preadv,
+ .bdrv_co_pwritev = pcache_co_pwritev,
+
+ .is_filter = true,
+ .bdrv_recurse_is_first_non_filter = pcache_recurse_is_first_non_filter,
+};
+
+static void bdrv_cache_init(void)
+{
+ bdrv_register(&bdrv_pcache);
+}
+
+block_init(bdrv_cache_init);
--
2.10.1
