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[Qemu-block] [PATCH 12/17] qcow2-dirty-bitmap: add IN_USE flag
From: |
Vladimir Sementsov-Ogievskiy |
Subject: |
[Qemu-block] [PATCH 12/17] qcow2-dirty-bitmap: add IN_USE flag |
Date: |
Wed, 17 Feb 2016 18:29:04 +0300 |
This flag is set on bitmap load and unset on store. If it is already
set when loading the bitmap, the bitmap should not be load (it is in
use by other drive or it is inconsistent (was not successfully saved))
Signed-off-by: Vladimir Sementsov-Ogievskiy <address@hidden>
---
block/qcow2-dirty-bitmap.c | 45 ++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 44 insertions(+), 1 deletion(-)
diff --git a/block/qcow2-dirty-bitmap.c b/block/qcow2-dirty-bitmap.c
index 18f271f..189b74b 100644
--- a/block/qcow2-dirty-bitmap.c
+++ b/block/qcow2-dirty-bitmap.c
@@ -40,7 +40,8 @@
#define BME_MAX_NAME_SIZE 1023
/* Bitmap directory entry flags */
-#define BME_RESERVED_FLAGS 0xffffffff
+#define BME_RESERVED_FLAGS 0xfffffffe
+#define BME_FLAG_IN_USE 1
/* bits [1, 8] U [56, 63] are reserved */
#define BME_TABLE_ENTRY_RESERVED_MASK 0xff000000000001fe
@@ -132,6 +133,29 @@ static QCow2BitmapHeader *bitmap_header(BDRVQcow2State *s,
(s->bitmap_directory + bitmap->offset);
}
+static int update_bitmap_header_sync(BlockDriverState *bs, QCow2Bitmap *bitmap)
+{
+ int ret;
+ BDRVQcow2State *s = bs->opaque;
+ QCow2BitmapHeader *h = bitmap_header(s, bitmap);
+
+ bitmap_header_to_be(h);
+ ret = bdrv_pwrite(bs->file->bs,
+ s->bitmap_directory_offset + bitmap->offset,
+ h, dir_entry_size(h));
+ bitmap_header_to_cpu(h);
+ if (ret < 0) {
+ return ret;
+ }
+
+ ret = bdrv_flush(bs);
+ if (ret < 0) {
+ return ret;
+ }
+
+ return 0;
+}
+
static int directory_read(BlockDriverState *bs, Error **errp)
{
int ret;
@@ -291,6 +315,11 @@ static BdrvDirtyBitmap *load_bitmap(BlockDriverState *bs,
QCow2Bitmap *bm,
bmh = bitmap_header(s, bm);
+ if (bmh->flags & BME_FLAG_IN_USE) {
+ error_setg(errp, "Bitmap '%s' is in use", bm->name);
+ return NULL;
+ }
+
bitmap_table = g_try_malloc(bmh->bitmap_table_size * sizeof(uint64_t));
if (bitmap_table == NULL) {
error_setg_errno(errp, -ENOMEM,
@@ -319,6 +348,13 @@ static BdrvDirtyBitmap *load_bitmap(BlockDriverState *bs,
QCow2Bitmap *bm,
goto fail;
}
+ bmh->flags |= BME_FLAG_IN_USE;
+ ret = update_bitmap_header_sync(bs, bm);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Could not set in_use in bitmap header");
+ goto fail;
+ }
+
g_free(bitmap_table);
return bitmap;
@@ -767,6 +803,13 @@ void qcow2_bitmap_store(BlockDriverState *bs,
goto finish;
}
+ bmh->flags &= ~BME_FLAG_IN_USE;
+ ret = update_bitmap_header_sync(bs, bm);
+ if (ret < 0) {
+ error_setg_errno(errp, ret, "Can't update bitmap header.");
+ goto finish;
+ }
+
finish:
g_free(bitmap_table);
}
--
1.8.3.1
- [Qemu-block] [PATCH 02/17] qcow2: Bitmaps extension: structs and consts, (continued)
- [Qemu-block] [PATCH 02/17] qcow2: Bitmaps extension: structs and consts, Vladimir Sementsov-Ogievskiy, 2016/02/17
- [Qemu-block] [PATCH 03/17] qcow2-dirty-bitmap: read dirty bitmap directory, Vladimir Sementsov-Ogievskiy, 2016/02/17
- [Qemu-block] [PATCH 04/17] qcow2-dirty-bitmap: add qcow2_bitmap_load(), Vladimir Sementsov-Ogievskiy, 2016/02/17
- [Qemu-block] [PATCH 05/17] qcow2-dirty-bitmap: add qcow2_bitmap_store(), Vladimir Sementsov-Ogievskiy, 2016/02/17
- [Qemu-block] [PATCH 09/17] block: add bdrv_load_dirty_bitmap(), Vladimir Sementsov-Ogievskiy, 2016/02/17
- [Qemu-block] [PATCH 07/17] qcow2-dirty-bitmap: add qcow2_bitmap_load_check(), Vladimir Sementsov-Ogievskiy, 2016/02/17
- [Qemu-block] [PATCH 06/17] qcow2: add dirty bitmaps extension, Vladimir Sementsov-Ogievskiy, 2016/02/17
- [Qemu-block] [PATCH 10/17] qcow2-dirty-bitmap: add autoclear bit, Vladimir Sementsov-Ogievskiy, 2016/02/17
- [Qemu-block] [PATCH 08/17] block: store persistent dirty bitmaps, Vladimir Sementsov-Ogievskiy, 2016/02/17
- [Qemu-block] [PATCH 11/17] qemu: command line option for dirty bitmaps, Vladimir Sementsov-Ogievskiy, 2016/02/17
- [Qemu-block] [PATCH 12/17] qcow2-dirty-bitmap: add IN_USE flag,
Vladimir Sementsov-Ogievskiy <=
- [Qemu-block] [PATCH 13/17] qcow2-dirty-bitmaps: disallow stroing bitmap to other bs, Vladimir Sementsov-Ogievskiy, 2016/02/17
- [Qemu-block] [PATCH 14/17] iotests: add VM.test_launcn(), Vladimir Sementsov-Ogievskiy, 2016/02/17
- [Qemu-block] [PATCH 16/17] qcow2-dirty-bitmap: add AUTO flag, Vladimir Sementsov-Ogievskiy, 2016/02/17
- [Qemu-block] [PATCH 15/17] iotests: test internal persistent dirty bitmap, Vladimir Sementsov-Ogievskiy, 2016/02/17
- [Qemu-block] [PATCH 17/17] qcow2-dirty-bitmap: add EXTRA_DATA_COMPATIBLE flag, Vladimir Sementsov-Ogievskiy, 2016/02/17
- Re: [Qemu-block] [Qemu-devel] [PATCH v4 RFC 00/17] qcow2: persistent dirty bitmaps, John Snow, 2016/02/26