[PATCH 1/6] hw/virtio-blk: Account discard operations

[Hanna Czenczek]

The acct_failed argument to virtio_blk_handle_rw_error() tells whether
there is accounting for this operation or not.  The only operation for
which there is none is discarding, which seems to be because at the time
of the introducing commit 37b06f8d46f ("virtio-blk: add DISCARD and
WRITE_ZEROES features"), BlockAcctType did not yet have a
BLOCK_ACCT_UNMAP variant.

It does have that now, though, so we may as well track those discard
operations with it, and can thus remove the acct_failed parameter.

Signed-off-by: Hanna Czenczek <hre...@redhat.com>
---
 hw/block/virtio-blk.c | 26 +++++++++++---------------
 1 file changed, 11 insertions(+), 15 deletions(-)

diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
index 6b92066aff4..56bfe1840c4 100644
--- a/hw/block/virtio-blk.c
+++ b/hw/block/virtio-blk.c
@@ -69,7 +69,7 @@ void virtio_blk_req_complete(VirtIOBlockReq *req, unsigned 
char status)
 }
 
 static int virtio_blk_handle_rw_error(VirtIOBlockReq *req, int error,
-    bool is_read, bool acct_failed)
+                                      bool is_read)
 {
     VirtIOBlock *s = req->dev;
     BlockErrorAction action = blk_get_error_action(s->blk, is_read, error);
@@ -85,9 +85,7 @@ static int virtio_blk_handle_rw_error(VirtIOBlockReq *req, 
int error,
         }
     } else if (action == BLOCK_ERROR_ACTION_REPORT) {
         virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR);
-        if (acct_failed) {
-            block_acct_failed(blk_get_stats(s->blk), &req->acct);
-        }
+        block_acct_failed(blk_get_stats(s->blk), &req->acct);
         g_free(req);
     }
 
@@ -124,7 +122,7 @@ static void virtio_blk_rw_complete(void *opaque, int ret)
              * the memory until the request is completed (which will
              * happen on the other side of the migration).
              */
-            if (virtio_blk_handle_rw_error(req, -ret, is_read, true)) {
+            if (virtio_blk_handle_rw_error(req, -ret, is_read)) {
                 continue;
             }
         }
@@ -140,7 +138,7 @@ static void virtio_blk_flush_complete(void *opaque, int ret)
     VirtIOBlockReq *req = opaque;
     VirtIOBlock *s = req->dev;
 
-    if (ret && virtio_blk_handle_rw_error(req, -ret, 0, true)) {
+    if (ret && virtio_blk_handle_rw_error(req, -ret, 0)) {
         return;
     }
 
@@ -153,17 +151,13 @@ static void virtio_blk_discard_write_zeroes_complete(void 
*opaque, int ret)
 {
     VirtIOBlockReq *req = opaque;
     VirtIOBlock *s = req->dev;
-    bool is_write_zeroes = (virtio_ldl_p(VIRTIO_DEVICE(s), &req->out.type) &
-                            ~VIRTIO_BLK_T_BARRIER) == 
VIRTIO_BLK_T_WRITE_ZEROES;
 
-    if (ret && virtio_blk_handle_rw_error(req, -ret, false, is_write_zeroes)) {
+    if (ret && virtio_blk_handle_rw_error(req, -ret, false)) {
         return;
     }
 
     virtio_blk_req_complete(req, VIRTIO_BLK_S_OK);
-    if (is_write_zeroes) {
-        block_acct_done(blk_get_stats(s->blk), &req->acct);
-    }
+    block_acct_done(blk_get_stats(s->blk), &req->acct);
     g_free(req);
 }
 
@@ -443,6 +437,9 @@ static uint8_t 
virtio_blk_handle_discard_write_zeroes(VirtIOBlockReq *req,
             goto err;
         }
 
+        block_acct_start(blk_get_stats(s->blk), &req->acct, bytes,
+                         BLOCK_ACCT_UNMAP);
+
         blk_aio_pdiscard(s->blk, sector << BDRV_SECTOR_BITS, bytes,
                          virtio_blk_discard_write_zeroes_complete, req);
     }
@@ -450,9 +447,8 @@ static uint8_t 
virtio_blk_handle_discard_write_zeroes(VirtIOBlockReq *req,
     return VIRTIO_BLK_S_OK;
 
 err:
-    if (is_write_zeroes) {
-        block_acct_invalid(blk_get_stats(s->blk), BLOCK_ACCT_WRITE);
-    }
+    block_acct_invalid(blk_get_stats(s->blk),
+                       is_write_zeroes ? BLOCK_ACCT_WRITE : BLOCK_ACCT_UNMAP);
     return err_status;
 }
 
-- 
2.55.0