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[Qemu-devel] [PATCH v14 18/19] block: Resize bitmaps on bdrv_truncate
From: |
John Snow |
Subject: |
[Qemu-devel] [PATCH v14 18/19] block: Resize bitmaps on bdrv_truncate |
Date: |
Fri, 20 Feb 2015 18:07:24 -0500 |
Signed-off-by: John Snow <address@hidden>
---
block.c | 20 ++++++++++++++++++++
include/block/block.h | 1 +
include/qemu/hbitmap.h | 10 ++++++++++
util/hbitmap.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 78 insertions(+)
diff --git a/block.c b/block.c
index f3a6dd4..59a8ec9 100644
--- a/block.c
+++ b/block.c
@@ -3514,6 +3514,7 @@ int bdrv_truncate(BlockDriverState *bs, int64_t offset)
ret = drv->bdrv_truncate(bs, offset);
if (ret == 0) {
ret = refresh_total_sectors(bs, offset >> BDRV_SECTOR_BITS);
+ bdrv_dirty_bitmap_truncate(bs);
if (bs->blk) {
blk_dev_resize_cb(bs->blk);
}
@@ -5524,6 +5525,25 @@ BdrvDirtyBitmap
*bdrv_reclaim_dirty_bitmap(BlockDriverState *bs,
return parent;
}
+static void dirty_bitmap_truncate(BdrvDirtyBitmap *bitmap, uint64_t size)
+{
+ assert(!bdrv_dirty_bitmap_frozen(bitmap));
+ hbitmap_truncate(bitmap->bitmap, size);
+}
+
+void bdrv_dirty_bitmap_truncate(BlockDriverState *bs)
+{
+ BdrvDirtyBitmap *bitmap;
+ uint64_t size = bdrv_nb_sectors(bs);
+
+ QLIST_FOREACH(bitmap, &bs->dirty_bitmaps, list) {
+ if (bdrv_dirty_bitmap_frozen(bitmap)) {
+ continue;
+ }
+ dirty_bitmap_truncate(bitmap, size);
+ }
+}
+
void bdrv_release_dirty_bitmap(BlockDriverState *bs, BdrvDirtyBitmap *bitmap)
{
BdrvDirtyBitmap *bm, *next;
diff --git a/include/block/block.h b/include/block/block.h
index f6a50ae..aa6912d 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -442,6 +442,7 @@ BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState
*bs,
uint32_t granularity,
const char *name,
Error **errp);
+void bdrv_dirty_bitmap_truncate(BlockDriverState *bs);
int bdrv_dirty_bitmap_create_successor(BlockDriverState *bs,
BdrvDirtyBitmap *bitmap,
Error **errp);
diff --git a/include/qemu/hbitmap.h b/include/qemu/hbitmap.h
index c19c1cb..a75157e 100644
--- a/include/qemu/hbitmap.h
+++ b/include/qemu/hbitmap.h
@@ -65,6 +65,16 @@ struct HBitmapIter {
HBitmap *hbitmap_alloc(uint64_t size, int granularity);
/**
+ * hbitmap_truncate:
+ * @hb: The bitmap to change the size of.
+ * @size: The number of elements to change the bitmap to accommodate.
+ *
+ * truncate or grow an existing bitmap to accommodate a new number of elements.
+ * This may invalidate existing HBitmapIterators.
+ */
+void hbitmap_truncate(HBitmap *hb, uint64_t size);
+
+/**
* hbitmap_merge:
* @a: The bitmap to store the result in.
* @b: The bitmap to merge into @a.
diff --git a/util/hbitmap.c b/util/hbitmap.c
index 962ff29..d17b850 100644
--- a/util/hbitmap.c
+++ b/util/hbitmap.c
@@ -90,6 +90,9 @@ struct HBitmap {
* bitmap will still allocate HBITMAP_LEVELS arrays.
*/
unsigned long *levels[HBITMAP_LEVELS];
+
+ /* The length of each levels[] array. */
+ uint64_t sizes[HBITMAP_LEVELS];
};
/* Advance hbi to the next nonzero word and return it. hbi->pos
@@ -384,6 +387,7 @@ HBitmap *hbitmap_alloc(uint64_t size, int granularity)
hb->granularity = granularity;
for (i = HBITMAP_LEVELS; i-- > 0; ) {
size = MAX((size + BITS_PER_LONG - 1) >> BITS_PER_LEVEL, 1);
+ hb->sizes[i] = size;
hb->levels[i] = g_new0(unsigned long, size);
}
@@ -396,6 +400,49 @@ HBitmap *hbitmap_alloc(uint64_t size, int granularity)
return hb;
}
+void hbitmap_truncate(HBitmap *hb, uint64_t size)
+{
+ bool truncate;
+ unsigned i;
+ uint64_t num_elements = size;
+
+ /* Size comes in as logical elements, adjust for granularity. */
+ size = (size + (1ULL << hb->granularity) - 1) >> hb->granularity;
+ assert(size <= ((uint64_t)1 << HBITMAP_LOG_MAX_SIZE));
+ truncate = size < hb->size;
+
+ if (size == hb->size) {
+ /* A hard day's work */
+ return;
+ }
+
+ hb->size = size;
+ for (i = HBITMAP_LEVELS; i-- > 0; ) {
+ size = MAX((size + BITS_PER_LONG - 1) >> BITS_PER_LEVEL, 1);
+ if (hb->sizes[i] == size) {
+ continue;
+ }
+ hb->sizes[i] = size;
+ hb->levels[i] = g_realloc_n(hb->levels[i], size, sizeof(unsigned
long));
+ }
+ assert(size == 1);
+
+ /* Clear out any "extra space" we may have that the user didn't request:
+ * It may have garbage data in it, now. */
+ if (truncate) {
+ /* Due to granularity fuzziness, we may accidentally reset some of
+ * the last bits that are actually valid. So, record the current value,
+ * reset the "dead range," then re-set the one sector we care about. */
+ bool status = hbitmap_get(hb, num_elements - 1);
+ uint64_t fix_count = (hb->size << hb->granularity) - num_elements;
+ hbitmap_reset(hb, num_elements, fix_count);
+ if (status) {
+ hbitmap_set(hb, num_elements - 1, 1);
+ }
+ }
+}
+
+
/**
* Given HBitmaps A and B, let A := A (BITOR) B.
* Bitmap B will not be modified.
--
1.9.3
- [Qemu-devel] [PATCH v14 09/19] qmp: add block-dirty-bitmap-clear, (continued)
- [Qemu-devel] [PATCH v14 09/19] qmp: add block-dirty-bitmap-clear, John Snow, 2015/02/20
- [Qemu-devel] [PATCH v14 14/19] iotests: add invalid input incremental backup tests, John Snow, 2015/02/20
- [Qemu-devel] [PATCH v14 08/19] qmp: Add support of "dirty-bitmap" sync mode for drive-backup, John Snow, 2015/02/20
- [Qemu-devel] [PATCH v14 10/19] qapi: Add transaction support to block-dirty-bitmap operations, John Snow, 2015/02/20
- [Qemu-devel] [PATCH v14 11/19] qmp: Add dirty bitmap status fields in query-block, John Snow, 2015/02/20
- [Qemu-devel] [PATCH v14 15/19] iotests: add simple incremental backup case, John Snow, 2015/02/20
- [Qemu-devel] [PATCH v14 17/19] iotests: add incremental backup failure recovery test, John Snow, 2015/02/20
- [Qemu-devel] [PATCH v14 16/19] iotests: add transactional incremental backup test, John Snow, 2015/02/20
- [Qemu-devel] [PATCH v14 12/19] block: add BdrvDirtyBitmap documentation, John Snow, 2015/02/20
- [Qemu-devel] [PATCH v14 18/19] block: Resize bitmaps on bdrv_truncate,
John Snow <=
- [Qemu-devel] [PATCH v14 19/19] docs: incremental backup documentation, John Snow, 2015/02/20
- Re: [Qemu-devel] [PATCH v14 00/19] block: incremental backup series, Max Reitz, 2015/02/23