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[Qemu-block] [PATCH v7 01/20] block: Add flag bits for image locking
From: |
Fam Zheng |
Subject: |
[Qemu-block] [PATCH v7 01/20] block: Add flag bits for image locking |
Date: |
Mon, 8 Aug 2016 21:13:14 +0800 |
Later the block layer will automatically lock the images to avoid unexpected
concurrent accesses to the same image, which will easily corrupt the metadata
or user data, unless in some very special cases, like migration.
The exceptional cases like shared storage migration and testing should
set BDRV_O_SHARED_LOCK or BDRV_O_NO_LOCK to advise an appropriate
locking mode.
Signed-off-by: Fam Zheng <address@hidden>
Reviewed-by: Max Reitz <address@hidden>
---
include/block/block.h | 2 ++
1 file changed, 2 insertions(+)
diff --git a/include/block/block.h b/include/block/block.h
index 11c162d..4f8450b 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -97,6 +97,8 @@ typedef struct HDGeometry {
select an appropriate protocol driver,
ignoring the format layer */
#define BDRV_O_NO_IO 0x10000 /* don't initialize for I/O */
+#define BDRV_O_NO_LOCK 0x20000 /* don't lock image file */
+#define BDRV_O_SHARED_LOCK 0x40000 /* lock the image file in shared mode */
#define BDRV_O_CACHE_MASK (BDRV_O_NOCACHE | BDRV_O_NO_FLUSH)
--
2.7.4
- [Qemu-block] [PATCH v7 00/20] block: Image locking series for 2.8, Fam Zheng, 2016/08/08
- [Qemu-block] [PATCH v7 01/20] block: Add flag bits for image locking,
Fam Zheng <=
- [Qemu-block] [PATCH v7 02/20] qapi: Add lock-mode in blockdev-add options, Fam Zheng, 2016/08/08
- [Qemu-block] [PATCH v7 03/20] block: Add and parse "lock-mode" option for image locking, Fam Zheng, 2016/08/08
- [Qemu-block] [PATCH v7 04/20] block: Introduce image file locking, Fam Zheng, 2016/08/08
- [Qemu-block] [PATCH v7 05/20] osdep: Add qemu_lock_fd and qemu_unlock_fd, Fam Zheng, 2016/08/08
- [Qemu-block] [PATCH v7 06/20] raw-posix: Add image locking support, Fam Zheng, 2016/08/08
- [Qemu-block] [PATCH v7 07/20] qemu-io: Add "-L" option for BDRV_O_NO_LOCK, Fam Zheng, 2016/08/08
- [Qemu-block] [PATCH v7 08/20] qemu-img: Add "-L" option to sub commands, Fam Zheng, 2016/08/08
- [Qemu-block] [PATCH v7 09/20] qemu-img: Update documentation of "-L" option, Fam Zheng, 2016/08/08
- [Qemu-block] [PATCH v7 10/20] qemu-nbd: Add "--no-lock/-L" option, Fam Zheng, 2016/08/08
- [Qemu-block] [PATCH v7 11/20] block: Don't lock drive-backup target image in none mode, Fam Zheng, 2016/08/08