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[Qemu-devel] [PATCH 4/7] block: close unused image files at the end of s
From: |
Paolo Bonzini |
Subject: |
[Qemu-devel] [PATCH 4/7] block: close unused image files at the end of streaming |
Date: |
Thu, 5 Apr 2012 17:42:58 +0200 |
From: Marcelo Tosatti <address@hidden>
Close the now unused images that were part of the previous backing file
chain and adjust ->backing_hd properly.
Note that this only works with relative paths.
Given the images:
/tmp/a/base.raw
/tmp/a/snap1.qcow2
/tmp/b/snap2.qcow2
chained as:
base(bak:"") <- snap1(bak:"base.raw") <- snap2(bak:"../a/snap1.qcow2")
merging snap1 and snap2 we will obtain:
base(bak:"") <- snap2(bak:"base.raw")
However this should be maintained by the user/admin: one can also
screw up relative paths using qemu-img manually.
Signed-off-by: Marcelo Tosatti <address@hidden>
Cc: Federico Simoncelli <address@hidden>
Signed-off-by: Paolo Bonzini <address@hidden>
---
block/stream.c | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)
diff --git a/block/stream.c b/block/stream.c
index 61ff7a2..54f2b39 100644
--- a/block/stream.c
+++ b/block/stream.c
@@ -76,6 +76,28 @@ static int coroutine_fn stream_populate(BlockDriverState *bs,
return bdrv_co_copy_on_readv(bs, sector_num, nb_sectors, &qiov);
}
+static void close_unused_images(BlockDriverState *top, BlockDriverState *base,
+ const char *base_id)
+{
+ BlockDriverState *intermediate;
+ intermediate = top->backing_hd;
+
+ while (intermediate) {
+ BlockDriverState *unused;
+
+ /* reached base */
+ if (intermediate == base) {
+ break;
+ }
+
+ unused = intermediate;
+ intermediate = intermediate->backing_hd;
+ unused->backing_hd = NULL;
+ bdrv_delete(unused);
+ }
+ top->backing_hd = base;
+}
+
/*
* Given an image chain: [BASE] -> [INTER1] -> [INTER2] -> [TOP]
*
@@ -223,6 +245,7 @@ retry:
base_id = s->backing_file_id;
}
ret = bdrv_change_backing_file(bs, base_id, NULL);
+ close_unused_images(bs, base, base_id);
}
qemu_vfree(buf);
--
1.7.9.3
- [Qemu-devel] [PATCH 0/7] Miscellaneous fixes for block and snapshots, Paolo Bonzini, 2012/04/05
- [Qemu-devel] [PATCH 1/7] block: add mode argument to blockdev-snapshot-sync, Paolo Bonzini, 2012/04/05
- [Qemu-devel] [PATCH 2/7] block: fail live snapshot if disk has no medium, Paolo Bonzini, 2012/04/05
- [Qemu-devel] [PATCH 3/7] block: fix snapshot with QED format, Paolo Bonzini, 2012/04/05
- [Qemu-devel] [PATCH 4/7] block: close unused image files at the end of streaming,
Paolo Bonzini <=
- [Qemu-devel] [PATCH 5/7] block: pass new base image format to bdrv_change_backing_file, Paolo Bonzini, 2012/04/05
- [Qemu-devel] [PATCH 7/7] block: update in-memory backing file and format, Paolo Bonzini, 2012/04/05
- [Qemu-devel] [PATCH 6/7] block: push bdrv_change_backing_file error checking up from drivers, Paolo Bonzini, 2012/04/05
- Re: [Qemu-devel] [PATCH 0/7] Miscellaneous fixes for block and snapshots, Paolo Bonzini, 2012/04/12