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[Qemu-devel] [PATCH V7 3/6] qcow2: do not free clusters when fail in hea
From: |
Wenchao Xia |
Subject: |
[Qemu-devel] [PATCH V7 3/6] qcow2: do not free clusters when fail in header update in qcow2_write_snapshots |
Date: |
Thu, 5 Dec 2013 20:02:49 +0800 |
Signed-off-by: Wenchao Xia <address@hidden>
Reviewed-by: Max Reitz <address@hidden>
---
block/qcow2-snapshot.c | 8 ++++++++
1 files changed, 8 insertions(+), 0 deletions(-)
diff --git a/block/qcow2-snapshot.c b/block/qcow2-snapshot.c
index d7ab4ae..55746c4 100644
--- a/block/qcow2-snapshot.c
+++ b/block/qcow2-snapshot.c
@@ -299,6 +299,14 @@ static int qcow2_write_snapshots(BlockDriverState *bs,
Error **errp)
"Failed in update of image header at %d with size %d",
(int)offsetof(QCowHeader, nb_snapshots),
(int)sizeof(header_data));
+
+ /*
+ * If the snapshot data part has been updated on disk, then the
+ * clusters at snapshot_offset may be used in next snapshot operation.
+ * If we free those clusters in fail path, they may be allocated and
+ * made dirty causing damage, so skip cluster free to be safe.
+ */
+ snapshots_offset = 0;
goto fail;
}
--
1.7.1
- [Qemu-devel] [PATCH V7 0/6] qcow2: rollback the modification on fail in snapshot creation, Wenchao Xia, 2013/12/05
- [Qemu-devel] [PATCH V7 5/6] blkdebug: add debug events for snapshot, Wenchao Xia, 2013/12/05
- [Qemu-devel] [PATCH V7 6/6] qemu-iotests: add test for qcow2 snapshot, Wenchao Xia, 2013/12/05
- Re: [Qemu-devel] [PATCH V7 0/6] qcow2: rollback the modification on fail in snapshot creation, Wenchao Xia, 2013/12/08
- Re: [Qemu-devel] [PATCH V7 0/6] qcow2: rollback the modification on fail in snapshot creation, Wenchao Xia, 2013/12/12
- Re: [Qemu-devel] [PATCH V7 0/6] qcow2: rollback the modification on fail in snapshot creation, Wenchao Xia, 2013/12/17