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[Qemu-devel] [PULL 09/13] block: Fix documentation for BDRV_REQ_MAY_UNMA
From: |
Kevin Wolf |
Subject: |
[Qemu-devel] [PULL 09/13] block: Fix documentation for BDRV_REQ_MAY_UNMAP |
Date: |
Mon, 30 Jul 2018 17:09:54 +0200 |
BDRV_REQ_MAY_UNMAP in a write_zeroes request does not only allow the
driver to unmap the blocks, but it actively requests that the blocks be
unmapped afterwards if at all possible.
Signed-off-by: Kevin Wolf <address@hidden>
---
include/block/block.h | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/include/block/block.h b/include/block/block.h
index f85e3a6ed3..4e0871aaf9 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -43,11 +43,12 @@ typedef struct BlockFragInfo {
typedef enum {
BDRV_REQ_COPY_ON_READ = 0x1,
BDRV_REQ_ZERO_WRITE = 0x2,
- /* The BDRV_REQ_MAY_UNMAP flag is used to indicate that the block driver
- * is allowed to optimize a write zeroes request by unmapping (discarding)
- * blocks if it is guaranteed that the result will read back as
- * zeroes. The flag is only passed to the driver if the block device is
- * opened with BDRV_O_UNMAP.
+
+ /*
+ * The BDRV_REQ_MAY_UNMAP flag is used in write_zeroes requests to indicate
+ * that the block driver should unmap (discard) blocks if it is guaranteed
+ * that the result will read back as zeroes. The flag is only passed to the
+ * driver if the block device is opened with BDRV_O_UNMAP.
*/
BDRV_REQ_MAY_UNMAP = 0x4,
--
2.13.6
- [Qemu-devel] [PULL 02/13] qcow2: A grammar fix in conflicting cache sizing error message, (continued)
- [Qemu-devel] [PULL 02/13] qcow2: A grammar fix in conflicting cache sizing error message, Kevin Wolf, 2018/07/30
- [Qemu-devel] [PULL 04/13] docs: Describe using images in writing iotests, Kevin Wolf, 2018/07/30
- [Qemu-devel] [PULL 03/13] file-posix: Handle EINTR in preallocation=full write, Kevin Wolf, 2018/07/30
- [Qemu-devel] [PULL 07/13] qemu-img: Add -C option for convert with copy offloading, Kevin Wolf, 2018/07/30
- [Qemu-devel] [PULL 12/13] block/qapi: Include anonymous BBs in query-blockstats, Kevin Wolf, 2018/07/30
- [Qemu-devel] [PULL 06/13] Revert "qemu-img: Document copy offloading implications with -S and -c", Kevin Wolf, 2018/07/30
- [Qemu-devel] [PULL 05/13] iotests: Don't lock /dev/null in 226, Kevin Wolf, 2018/07/30
- [Qemu-devel] [PULL 11/13] block/qapi: Add 'qdev' field to query-blockstats result, Kevin Wolf, 2018/07/30
- [Qemu-devel] [PULL 08/13] iotests: Add test for 'qemu-img convert -C' compatibility, Kevin Wolf, 2018/07/30
- [Qemu-devel] [PULL 10/13] file-posix: Fix write_zeroes with unmap on block devices, Kevin Wolf, 2018/07/30
- [Qemu-devel] [PULL 09/13] block: Fix documentation for BDRV_REQ_MAY_UNMAP,
Kevin Wolf <=
- [Qemu-devel] [PULL 13/13] qemu-iotests: Test query-blockstats with -drive and -blockdev, Kevin Wolf, 2018/07/30
- Re: [Qemu-devel] [PULL 00/13] Block layer patches, Peter Maydell, 2018/07/31