The block multiwrite code pretends to be able to merge overlapping requests,
but doesn't do so in fact. This leads to I/O errors (for example on mkfs
of a large virtio disk).
Signed-off-by: Avi Kivity <avi@xxxxxxxxxx>
---
block.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/block.c b/block.c
index 48305b7..0e44e26 100644
--- a/block.c
+++ b/block.c
@@ -1956,8 +1956,8 @@ static int multiwrite_merge(BlockDriverState *bs, BlockRequest *reqs,
int64_t oldreq_last = reqs[outidx].sector + reqs[outidx].nb_sectors;
// This handles the cases that are valid for all block drivers, namely
- // exactly sequential writes and overlapping writes.
- if (reqs[i].sector <= oldreq_last) {
+ // exactly sequential writes
+ if (reqs[i].sector == oldreq_last) {
merge = 1;
}
--
1.6.6.1
--
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