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[Qemu-devel] [PATCH v2 5/5] block: Always enable discard on the protocol
From: |
Kevin Wolf |
Subject: |
[Qemu-devel] [PATCH v2 5/5] block: Always enable discard on the protocol level |
Date: |
Wed, 19 Jun 2013 13:44:21 +0200 |
Turning on discard options in qcow2 doesn't help a lot when the discard
requests that it issues are thrown away by the raw-posix layer. This
patch always enables discard functionality on the protocol level so that
it's the image format's responsibility to send (or not) discard
requests. Requests sent by the guest will be allowed or ignored by the
top level BlockDriverState, which depends on the discard=... option like
before.
In particular, this means that even without specifying options, the
qcow2 default of discarding deleted snapshots actually takes effect now,
both for qemu and qemu-img.
Signed-off-by: Kevin Wolf <address@hidden>
---
block.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/block.c b/block.c
index b88ad2f..8e77d46 100644
--- a/block.c
+++ b/block.c
@@ -1045,7 +1045,7 @@ int bdrv_open(BlockDriverState *bs, const char *filename,
QDict *options,
extract_subqdict(options, &file_options, "file.");
ret = bdrv_file_open(&file, filename, file_options,
- bdrv_open_flags(bs, flags));
+ bdrv_open_flags(bs, flags | BDRV_O_UNMAP));
if (ret < 0) {
goto fail;
}
--
1.8.1.4
- [Qemu-devel] [PATCH v2 0/5] qcow2: Discard freed clusters, Kevin Wolf, 2013/06/19
- [Qemu-devel] [PATCH v2 1/5] Revert "block: Disable driver-specific options for 1.5", Kevin Wolf, 2013/06/19
- [Qemu-devel] [PATCH v2 5/5] block: Always enable discard on the protocol level,
Kevin Wolf <=
- [Qemu-devel] [PATCH v2 3/5] qcow2: Options to enable discard for freed clusters, Kevin Wolf, 2013/06/19
- [Qemu-devel] [PATCH v2 4/5] qcow2: Batch discards, Kevin Wolf, 2013/06/19
- [Qemu-devel] [PATCH v2 2/5] qcow2: Add refcount update reason to all callers, Kevin Wolf, 2013/06/19
- Re: [Qemu-devel] [PATCH v2 0/5] qcow2: Discard freed clusters, Stefan Hajnoczi, 2013/06/20