block: Extract the block accounting code

The plan is to add new accounting metrics (latency, invalid requests, failed
requests, queue depth) and block.c is overpopulated so it will be better to work
in a separate module.

Moreover the long term plan is to have statistics in each of the BDS of the graph
for metrology purpose; this means that the device model statistics must move from
the topmost BDS to the device model.

So we need to decouple the statistic code from BlockDriverState.

This is another argument for the extraction of the code in a separate module.

CC: Kevin Wolf <kwolf@redhat.com>
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Max Reitz <mreitz@redhat.com>
CC: Eric Blake <eblake@redhat.com>
CC: Benoit Canet <benoit@irqsave.net>
CC: Fam Zheng <famz@redhat.com>
CC: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
CC: Paolo Bonzini <pbonzini@redhat.com>

Signed-off-by: Benoît Canet <benoit.canet@nodalink.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

2 files changed, 58 insertions, 0 deletions

diff --git a/block/Makefile.objs b/block/Makefile.objs
index f45f9399aa..c9c8bbbcde 100644
--- a/block/Makefile.objs
+++ b/block/Makefile.objs
@@ -18,6 +18,7 @@ block-obj-$(CONFIG_RBD) += rbd.o
 block-obj-$(CONFIG_GLUSTERFS) += gluster.o
 block-obj-$(CONFIG_ARCHIPELAGO) += archipelago.o
 block-obj-$(CONFIG_LIBSSH2) += ssh.o
+block-obj-y += accounting.o
 
 common-obj-y += stream.o
 common-obj-y += commit.o
diff --git a/block/accounting.c b/block/accounting.c
new file mode 100644
index 0000000000..702542e2a6
--- /dev/null
+++ b/block/accounting.c
@@ -0,0 +1,57 @@
+/*
+ * QEMU System Emulator block accounting
+ *
+ * Copyright (c) 2011 Christoph Hellwig
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "block/accounting.h"
+#include "block/block_int.h"
+
+void
+bdrv_acct_start(BlockDriverState *bs, BlockAcctCookie *cookie, int64_t bytes,
+        enum BlockAcctType type)
+{
+    assert(type < BDRV_MAX_IOTYPE);
+
+    cookie->bytes = bytes;
+    cookie->start_time_ns = get_clock();
+    cookie->type = type;
+}
+
+void
+bdrv_acct_done(BlockDriverState *bs, BlockAcctCookie *cookie)
+{
+    assert(cookie->type < BDRV_MAX_IOTYPE);
+
+    bs->stats.nr_bytes[cookie->type] += cookie->bytes;
+    bs->stats.nr_ops[cookie->type]++;
+    bs->stats.total_time_ns[cookie->type] += get_clock() -
+                                             cookie->start_time_ns;
+}
+
+
+void bdrv_acct_highest_sector(BlockDriverState *bs, int64_t sector_num,
+                              unsigned int nb_sectors)
+{
+    if (bs->stats.wr_highest_sector < sector_num + nb_sectors - 1) {
+        bs->stats.wr_highest_sector = sector_num + nb_sectors - 1;
+    }
+}