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[PULL,12/48] block drivers: expose requirement for write same alignment from formats

Message ID 1386347807-27359-13-git-send-email-stefanha@redhat.com
State New
Headers show

Commit Message

Stefan Hajnoczi Dec. 6, 2013, 4:36 p.m. UTC 
From: Paolo Bonzini <pbonzini@redhat.com>

This will let misaligned but large requests use zero clusters.  This
is important because the cluster size is not guest visible.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 block/qcow2.c | 1 +
 block/qed.c   | 1 +
 block/vmdk.c  | 4 ++++
 3 files changed, 6 insertions(+)
diff mbox

Patch

diff --git a/block/qcow2.c b/block/qcow2.c
index 41e454a..19e0374 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -718,6 +718,7 @@  static int qcow2_open(BlockDriverState *bs, QDict *options, int flags,
     }
 
     qemu_opts_del(opts);
+    bs->bl.write_zeroes_alignment = s->cluster_sectors;
 
     if (s->use_lazy_refcounts && s->qcow_version < 3) {
         error_setg(errp, "Lazy refcounts require a qcow2 image with at least "
diff --git a/block/qed.c b/block/qed.c
index 59516a5..450a1fa 100644
--- a/block/qed.c
+++ b/block/qed.c
@@ -495,6 +495,7 @@  static int bdrv_qed_open(BlockDriverState *bs, QDict *options, int flags,
         }
     }
 
+    bs->bl.write_zeroes_alignment = s->header.cluster_size >> BDRV_SECTOR_BITS;
     s->need_check_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
                                             qed_need_check_timer_cb, s);
 
diff --git a/block/vmdk.c b/block/vmdk.c
index eb84f46..0734bc2 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -428,6 +428,10 @@  static int vmdk_add_extent(BlockDriverState *bs,
     extent->l2_size = l2_size;
     extent->cluster_sectors = flat ? sectors : cluster_sectors;
 
+    if (!flat) {
+        bs->bl.write_zeroes_alignment =
+            MAX(bs->bl.write_zeroes_alignment, cluster_sectors);
+    }
     if (s->num_extents > 1) {
         extent->end_sector = (*(extent - 1)).end_sector + extent->sectors;
     } else {