[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-block] [PATCH v2 2/9] block: BLK_PERM_WRITE includes ..._UNCHANGED
From: |
Max Reitz |
Subject: |
[Qemu-block] [PATCH v2 2/9] block: BLK_PERM_WRITE includes ..._UNCHANGED |
Date: |
Sat, 21 Apr 2018 15:29:22 +0200 |
Currently we never actually check whether the WRITE_UNCHANGED
permission has been taken for unchanging writes. But the one check that
is commented out checks both WRITE and WRITE_UNCHANGED; and considering
that WRITE_UNCHANGED is already documented as being weaker than WRITE,
we should probably explicitly document WRITE to include WRITE_UNCHANGED.
Signed-off-by: Max Reitz <address@hidden>
Reviewed-by: Stefan Hajnoczi <address@hidden>
Reviewed-by: Alberto Garcia <address@hidden>
---
include/block/block.h | 3 +++
1 file changed, 3 insertions(+)
diff --git a/include/block/block.h b/include/block/block.h
index cdec3639a3..397b5e8d44 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -205,6 +205,9 @@ enum {
* This permission (which is weaker than BLK_PERM_WRITE) is both enough and
* required for writes to the block node when the caller promises that
* the visible disk content doesn't change.
+ *
+ * As the BLK_PERM_WRITE permission is strictly stronger, either is
+ * sufficient to perform an unchanging write.
*/
BLK_PERM_WRITE_UNCHANGED = 0x04,
--
2.14.3
- [Qemu-block] [PATCH v2 0/9] block: Add COR filter driver, Max Reitz, 2018/04/21
- [Qemu-block] [PATCH v2 2/9] block: BLK_PERM_WRITE includes ..._UNCHANGED,
Max Reitz <=
- [Qemu-block] [PATCH v2 3/9] block: Add BDRV_REQ_WRITE_UNCHANGED flag, Max Reitz, 2018/04/21
- Re: [Qemu-block] [Qemu-devel] [PATCH v2 3/9] block: Add BDRV_REQ_WRITE_UNCHANGED flag, Eric Blake, 2018/04/25
- Re: [Qemu-block] [Qemu-devel] [PATCH v2 3/9] block: Add BDRV_REQ_WRITE_UNCHANGED flag, Max Reitz, 2018/04/25
- Re: [Qemu-block] [Qemu-devel] [PATCH v2 3/9] block: Add BDRV_REQ_WRITE_UNCHANGED flag, Eric Blake, 2018/04/25
- Re: [Qemu-block] [Qemu-devel] [PATCH v2 3/9] block: Add BDRV_REQ_WRITE_UNCHANGED flag, Kevin Wolf, 2018/04/26
- Re: [Qemu-block] [Qemu-devel] [PATCH v2 3/9] block: Add BDRV_REQ_WRITE_UNCHANGED flag, Max Reitz, 2018/04/28
- Re: [Qemu-block] [Qemu-devel] [PATCH v2 3/9] block: Add BDRV_REQ_WRITE_UNCHANGED flag, Kevin Wolf, 2018/04/30
[Qemu-block] [PATCH v2 4/9] block: Set BDRV_REQ_WRITE_UNCHANGED for COR writes, Max Reitz, 2018/04/21
[Qemu-block] [PATCH v2 5/9] block/quorum: Support BDRV_REQ_WRITE_UNCHANGED, Max Reitz, 2018/04/21
[Qemu-block] [PATCH v2 6/9] block: Support BDRV_REQ_WRITE_UNCHANGED in filters, Max Reitz, 2018/04/21