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[Qemu-devel] [PATCH v7 16/20] qcow2: Switch qcow2_measure() to byte-base
From: |
Eric Blake |
Subject: |
[Qemu-devel] [PATCH v7 16/20] qcow2: Switch qcow2_measure() to byte-based iteration |
Date: |
Tue, 12 Sep 2017 15:31:15 -0500 |
This is new code, but it is easier to read if it makes passes over
the image using bytes rather than sectors (and will get easier in
the future when bdrv_get_block_status is converted to byte-based).
Signed-off-by: Eric Blake <address@hidden>
Reviewed-by: John Snow <address@hidden>
---
v7: tweak constant given to MIN (no semantic change, R-b kept) [Kevin]
v6: separate bug fix to earlier patch
v5: new patch
---
block/qcow2.c | 22 ++++++++++------------
1 file changed, 10 insertions(+), 12 deletions(-)
diff --git a/block/qcow2.c b/block/qcow2.c
index bae5893327..64dcd98a91 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -3647,20 +3647,19 @@ static BlockMeasureInfo *qcow2_measure(QemuOpts *opts,
BlockDriverState *in_bs,
*/
required = virtual_size;
} else {
- int cluster_sectors = cluster_size / BDRV_SECTOR_SIZE;
- int64_t sector_num;
+ int64_t offset;
int pnum = 0;
- for (sector_num = 0;
- sector_num < ssize / BDRV_SECTOR_SIZE;
- sector_num += pnum) {
- int nb_sectors = MIN(ssize / BDRV_SECTOR_SIZE - sector_num,
- BDRV_REQUEST_MAX_SECTORS);
+ for (offset = 0; offset < ssize;
+ offset += pnum * BDRV_SECTOR_SIZE) {
+ int nb_sectors = MIN(ssize - offset,
+ BDRV_REQUEST_MAX_BYTES) /
BDRV_SECTOR_SIZE;
BlockDriverState *file;
int64_t ret;
ret = bdrv_get_block_status_above(in_bs, NULL,
- sector_num, nb_sectors,
+ offset >> BDRV_SECTOR_BITS,
+ nb_sectors,
&pnum, &file);
if (ret < 0) {
error_setg_errno(&local_err, -ret,
@@ -3673,12 +3672,11 @@ static BlockMeasureInfo *qcow2_measure(QemuOpts *opts,
BlockDriverState *in_bs,
} else if ((ret & (BDRV_BLOCK_DATA | BDRV_BLOCK_ALLOCATED)) ==
(BDRV_BLOCK_DATA | BDRV_BLOCK_ALLOCATED)) {
/* Extend pnum to end of cluster for next iteration */
- pnum = ROUND_UP(sector_num + pnum, cluster_sectors) -
- sector_num;
+ pnum = (ROUND_UP(offset + pnum * BDRV_SECTOR_SIZE,
+ cluster_size) - offset) >> BDRV_SECTOR_BITS;
/* Count clusters we've seen */
- required += (sector_num % cluster_sectors + pnum) *
- BDRV_SECTOR_SIZE;
+ required += offset % cluster_size + pnum *
BDRV_SECTOR_SIZE;
}
}
}
--
2.13.5
- [Qemu-devel] [PATCH v7 11/20] dirty-bitmap: Change bdrv_dirty_iter_next() to report byte offset, (continued)
- [Qemu-devel] [PATCH v7 10/20] dirty-bitmap: Set iterator start by offset, not sector, Eric Blake, 2017/09/12
- [Qemu-devel] [PATCH v7 12/20] dirty-bitmap: Change bdrv_get_dirty_count() to report bytes, Eric Blake, 2017/09/12
- [Qemu-devel] [PATCH v7 13/20] dirty-bitmap: Change bdrv_get_dirty_locked() to take bytes, Eric Blake, 2017/09/12
- [Qemu-devel] [PATCH v7 14/20] dirty-bitmap: Change bdrv_[re]set_dirty_bitmap() to use bytes, Eric Blake, 2017/09/12
- [Qemu-devel] [PATCH v7 15/20] mirror: Switch mirror_dirty_init() to byte-based iteration, Eric Blake, 2017/09/12
- [Qemu-devel] [PATCH v7 16/20] qcow2: Switch qcow2_measure() to byte-based iteration,
Eric Blake <=
- [Qemu-devel] [PATCH v7 17/20] qcow2: Switch load_bitmap_data() to byte-based iteration, Eric Blake, 2017/09/12
- [Qemu-devel] [PATCH v7 18/20] qcow2: Switch store_bitmap_data() to byte-based iteration, Eric Blake, 2017/09/12
- [Qemu-devel] [PATCH v7 19/20] dirty-bitmap: Switch bdrv_set_dirty() to bytes, Eric Blake, 2017/09/12
- [Qemu-devel] [PATCH v7 20/20] dirty-bitmap: Convert internal hbitmap size/granularity, Eric Blake, 2017/09/12