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[Qemu-devel] [PATCH v3 03/11] dirty-bitmap: Track size in bytes
From: |
Eric Blake |
Subject: |
[Qemu-devel] [PATCH v3 03/11] dirty-bitmap: Track size in bytes |
Date: |
Wed, 28 Jun 2017 12:55:26 -0500 |
We are still using an internal hbitmap that tracks a size in sectors,
with the granularity scaled down accordingly, because it lets us
use a shortcut for our iterators which are currently sector-based.
But there's no reason we can't track the dirty bitmap size in bytes,
since it is an internal-only variable.
Use is_power_of_2() while at it, instead of open-coding that.
Signed-off-by: Eric Blake <address@hidden>
Reviewed-by: John Snow <address@hidden>
---
v2: tweak commit message, no code change
---
block/dirty-bitmap.c | 23 +++++++++++++----------
1 file changed, 13 insertions(+), 10 deletions(-)
diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
index 13febf2..b2b9342 100644
--- a/block/dirty-bitmap.c
+++ b/block/dirty-bitmap.c
@@ -42,7 +42,7 @@ struct BdrvDirtyBitmap {
HBitmap *meta; /* Meta dirty bitmap */
BdrvDirtyBitmap *successor; /* Anonymous child; implies frozen status */
char *name; /* Optional non-empty unique ID */
- int64_t size; /* Size of the bitmap (Number of sectors) */
+ int64_t size; /* Size of the bitmap, in bytes */
bool disabled; /* Bitmap is read-only */
int active_iterators; /* How many iterators are active */
QLIST_ENTRY(BdrvDirtyBitmap) list;
@@ -103,17 +103,14 @@ BdrvDirtyBitmap
*bdrv_create_dirty_bitmap(BlockDriverState *bs,
{
int64_t bitmap_size;
BdrvDirtyBitmap *bitmap;
- uint32_t sector_granularity;
- assert((granularity & (granularity - 1)) == 0);
+ assert(is_power_of_2(granularity) && granularity >= BDRV_SECTOR_SIZE);
if (name && bdrv_find_dirty_bitmap(bs, name)) {
error_setg(errp, "Bitmap already exists: %s", name);
return NULL;
}
- sector_granularity = granularity >> BDRV_SECTOR_BITS;
- assert(sector_granularity);
- bitmap_size = bdrv_nb_sectors(bs);
+ bitmap_size = bdrv_getlength(bs);
if (bitmap_size < 0) {
error_setg_errno(errp, -bitmap_size, "could not get length of device");
errno = -bitmap_size;
@@ -121,7 +118,12 @@ BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState
*bs,
}
bitmap = g_new0(BdrvDirtyBitmap, 1);
bitmap->mutex = &bs->dirty_bitmap_mutex;
- bitmap->bitmap = hbitmap_alloc(bitmap_size, ctz32(sector_granularity));
+ /*
+ * TODO - let hbitmap track full granularity. For now, it is tracking
+ * only sector granularity, as a shortcut for our iterators.
+ */
+ bitmap->bitmap = hbitmap_alloc(bitmap_size >> BDRV_SECTOR_BITS,
+ ctz32(granularity) - BDRV_SECTOR_BITS);
bitmap->size = bitmap_size;
bitmap->name = g_strdup(name);
bitmap->disabled = false;
@@ -284,13 +286,14 @@ BdrvDirtyBitmap
*bdrv_reclaim_dirty_bitmap(BlockDriverState *bs,
void bdrv_dirty_bitmap_truncate(BlockDriverState *bs)
{
BdrvDirtyBitmap *bitmap;
- uint64_t size = bdrv_nb_sectors(bs);
+ int64_t size = bdrv_getlength(bs);
+ assert(size >= 0);
bdrv_dirty_bitmaps_lock(bs);
QLIST_FOREACH(bitmap, &bs->dirty_bitmaps, list) {
assert(!bdrv_dirty_bitmap_frozen(bitmap));
assert(!bitmap->active_iterators);
- hbitmap_truncate(bitmap->bitmap, size);
+ hbitmap_truncate(bitmap->bitmap, size >> BDRV_SECTOR_BITS);
bitmap->size = size;
}
bdrv_dirty_bitmaps_unlock(bs);
@@ -490,7 +493,7 @@ void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap,
HBitmap **out)
hbitmap_reset_all(bitmap->bitmap);
} else {
HBitmap *backup = bitmap->bitmap;
- bitmap->bitmap = hbitmap_alloc(bitmap->size,
+ bitmap->bitmap = hbitmap_alloc(bitmap->size >> BDRV_SECTOR_BITS,
hbitmap_granularity(backup));
*out = backup;
}
--
2.9.4
- [Qemu-devel] [PATCH v3 00/11] make dirty-bitmap byte-based, Eric Blake, 2017/06/28
- [Qemu-devel] [PATCH v3 01/11] dirty-bitmap: Report BlockDirtyInfo.count in bytes, as documented, Eric Blake, 2017/06/28
- [Qemu-devel] [PATCH v3 02/11] dirty-bitmap: Drop unused functions, Eric Blake, 2017/06/28
- [Qemu-devel] [PATCH v3 03/11] dirty-bitmap: Track size in bytes,
Eric Blake <=
- [Qemu-devel] [PATCH v3 05/11] dirty-bitmap: Change bdrv_dirty_iter_next() to report byte offset, Eric Blake, 2017/06/28
- [Qemu-devel] [PATCH v3 04/11] dirty-bitmap: Set iterator start by offset, not sector, Eric Blake, 2017/06/28
- [Qemu-devel] [PATCH v3 06/11] dirty-bitmap: Change bdrv_get_dirty_count() to report bytes, Eric Blake, 2017/06/28
- [Qemu-devel] [PATCH v3 07/11] dirty-bitmap: Change bdrv_get_dirty_locked() to take bytes, Eric Blake, 2017/06/28
- [Qemu-devel] [PATCH v3 08/11] dirty-bitmap: Change bdrv_[re]set_dirty_bitmap() to use bytes, Eric Blake, 2017/06/28
- [Qemu-devel] [PATCH v3 09/11] mirror: Switch mirror_dirty_init() to byte-based iteration, Eric Blake, 2017/06/28
- [Qemu-devel] [PATCH v3 10/11] dirty-bitmap: Switch bdrv_set_dirty() to bytes, Eric Blake, 2017/06/28
- [Qemu-devel] [PATCH v3 11/11] dirty-bitmap: Convert internal hbitmap size/granularity, Eric Blake, 2017/06/28
- Re: [Qemu-devel] [PATCH v3 00/11] make dirty-bitmap byte-based, Vladimir Sementsov-Ogievskiy, 2017/06/29