block: explicit I/O accounting

Decouple the I/O accounting from bdrv_aio_readv/writev/flush and
make the hardware models call directly into the accounting helpers.

This means:
 - we do not count internal requests from image formats in addition
   to guest originating I/O
 - we do not double count I/O ops if the device model handles it
   chunk wise
 - we only account I/O once it actuall is done
 - can extent I/O accounting to synchronous or coroutine I/O easily
 - implement I/O latency tracking easily (see the next patch)

I've conveted the existing device model callers to the new model,
device models that are using synchronous I/O and weren't accounted
before haven't been updated yet.  Also scsi hasn't been converted
to the end-to-end accounting as I want to defer that after the pending
scsi layer overhaul.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

1 files changed, 29 insertions, 11 deletions

diff --git a/hw/ide/macio.c b/hw/ide/macio.c
index 44fb3fef60..fdf5d75082 100644
--- a/hw/ide/macio.c
+++ b/hw/ide/macio.c
@@ -52,8 +52,7 @@ static void pmac_ide_atapi_transfer_cb(void *opaque, int ret)
         m->aiocb = NULL;
         qemu_sglist_destroy(&s->sg);
         ide_atapi_io_error(s, ret);
-        io->dma_end(opaque);
-        return;
+        goto done;
     }
 
     if (s->io_buffer_size > 0) {
@@ -71,8 +70,7 @@ static void pmac_ide_atapi_transfer_cb(void *opaque, int ret)
         ide_atapi_cmd_ok(s);
 
     if (io->len == 0) {
-        io->dma_end(opaque);
-        return;
+        goto done;
     }
 
     /* launch next transfer */
@@ -92,9 +90,14 @@ static void pmac_ide_atapi_transfer_cb(void *opaque, int ret)
         /* Note: media not present is the most likely case */
         ide_atapi_cmd_error(s, SENSE_NOT_READY,
                             ASC_MEDIUM_NOT_PRESENT);
-        io->dma_end(opaque);
-        return;
+        goto done;
     }
+    return;
+
+done:
+    bdrv_acct_done(s->bs, &s->acct);
+    io->dma_end(opaque);
+    return;
 }
 
 static void pmac_ide_transfer_cb(void *opaque, int ret)
@@ -109,8 +112,7 @@ static void pmac_ide_transfer_cb(void *opaque, int ret)
         m->aiocb = NULL;
         qemu_sglist_destroy(&s->sg);
 	ide_dma_error(s);
-        io->dma_end(io);
-        return;
+        goto done;
     }
 
     sector_num = ide_get_sector(s);
@@ -130,10 +132,8 @@ static void pmac_ide_transfer_cb(void *opaque, int ret)
     }
 
     /* end of DMA ? */
-
     if (io->len == 0) {
-        io->dma_end(io);
-	return;
+        goto done;
     }
 
     /* launch next transfer */
@@ -163,6 +163,12 @@ static void pmac_ide_transfer_cb(void *opaque, int ret)
 
     if (!m->aiocb)
         pmac_ide_transfer_cb(io, -1);
+    return;
+done:
+    if (s->dma_cmd == IDE_DMA_READ || s->dma_cmd == IDE_DMA_WRITE) {
+        bdrv_acct_done(s->bs, &s->acct);
+    }
+    io->dma_end(io);
 }
 
 static void pmac_ide_transfer(DBDMA_io *io)
@@ -172,10 +178,22 @@ static void pmac_ide_transfer(DBDMA_io *io)
 
     s->io_buffer_size = 0;
     if (s->drive_kind == IDE_CD) {
+        bdrv_acct_start(s->bs, &s->acct, io->len, BDRV_ACCT_READ);
         pmac_ide_atapi_transfer_cb(io, 0);
         return;
     }
 
+    switch (s->dma_cmd) {
+    case IDE_DMA_READ:
+        bdrv_acct_start(s->bs, &s->acct, io->len, BDRV_ACCT_READ);
+        break;
+    case IDE_DMA_WRITE:
+        bdrv_acct_start(s->bs, &s->acct, io->len, BDRV_ACCT_WRITE);
+        break;
+    default:
+        break;
+    }
+
     pmac_ide_transfer_cb(io, 0);
 }