[Qemu-block] [PATCH v2 6/9] block: Use common req handling for discard

[Fam Zheng]

Reuse the new bdrv_co_write_req_prepare/finish helpers. The variation
here is that discard requests don't affect bs->wr_highest_offset.

Signed-off-by: Fam Zheng <address@hidden>
---
 block/io.c | 21 ++++++++++++++-------
 1 file changed, 14 insertions(+), 7 deletions(-)

diff --git a/block/io.c b/block/io.c
index f06978dda0..912fcb962a 100644
--- a/block/io.c
+++ b/block/io.c
@@ -1582,7 +1582,18 @@ bdrv_co_write_req_finish(BdrvChild *child, 
BdrvTrackedRequest *req, int ret)
         bdrv_parent_cb_resize(bs);
         bdrv_dirty_bitmap_truncate(bs, end_sector << BDRV_SECTOR_BITS);
     }
-    bdrv_set_dirty(bs, req->offset, req->bytes);
+    if (req->bytes) {
+        switch (req->type) {
+        case BDRV_TRACKED_WRITE:
+            stat64_max(&bs->wr_highest_offset, req->offset + req->bytes);
+            /* fall through, to set dirty bits */
+        case BDRV_TRACKED_DISCARD:
+            bdrv_set_dirty(bs, req->offset, req->bytes);
+            break;
+        default:
+            break;
+        }
+    }
 }
 
 /*
@@ -2643,10 +2654,7 @@ int coroutine_fn bdrv_co_pdiscard(BdrvChild *child, 
int64_t offset, int bytes)
     ret = bdrv_check_byte_request(bs, offset, bytes);
     if (ret < 0) {
         return ret;
-    } else if (bs->read_only) {
-        return -EPERM;
     }
-    assert(!(bs->open_flags & BDRV_O_INACTIVE));
 
     /* Do nothing if disabled.  */
     if (!(bs->open_flags & BDRV_O_UNMAP)) {
@@ -2670,7 +2678,7 @@ int coroutine_fn bdrv_co_pdiscard(BdrvChild *child, 
int64_t offset, int bytes)
     bdrv_inc_in_flight(bs);
     tracked_request_begin(&req, bs, offset, bytes, BDRV_TRACKED_DISCARD);
 
-    ret = notifier_with_return_list_notify(&bs->before_write_notifiers, &req);
+    ret = bdrv_co_write_req_prepare(child, &req, 0);
     if (ret < 0) {
         goto out;
     }
@@ -2736,8 +2744,7 @@ int coroutine_fn bdrv_co_pdiscard(BdrvChild *child, 
int64_t offset, int bytes)
     }
     ret = 0;
 out:
-    atomic_inc(&bs->write_gen);
-    bdrv_set_dirty(bs, req.offset, req.bytes);
+    bdrv_co_write_req_finish(child, &req, ret);
     tracked_request_end(&req);
     bdrv_dec_in_flight(bs);
     return ret;
-- 
2.17.1