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-rw-r--r--qemu-img.c22
-rwxr-xr-xtests/qemu-iotests/2517
2 files changed, 27 insertions, 2 deletions
diff --git a/qemu-img.c b/qemu-img.c
index d0b1c97..37365d0 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -1666,6 +1666,7 @@ enum ImgConvertBlockStatus {
typedef struct ImgConvertState {
BlockBackend **src;
int64_t *src_sectors;
+ int *src_alignment;
int src_num;
int64_t total_sectors;
int64_t allocated_sectors;
@@ -1732,6 +1733,7 @@ static int convert_iteration_sectors(ImgConvertState *s, int64_t sector_num)
if (s->sector_next_status <= sector_num) {
uint64_t offset = (sector_num - src_cur_offset) * BDRV_SECTOR_SIZE;
int64_t count;
+ int tail;
BlockDriverState *src_bs = blk_bs(s->src[src_cur]);
BlockDriverState *base;
@@ -1772,6 +1774,16 @@ static int convert_iteration_sectors(ImgConvertState *s, int64_t sector_num)
n = DIV_ROUND_UP(count, BDRV_SECTOR_SIZE);
+ /*
+ * Avoid that s->sector_next_status becomes unaligned to the source
+ * request alignment and/or cluster size to avoid unnecessary read
+ * cycles.
+ */
+ tail = (sector_num - src_cur_offset + n) % s->src_alignment[src_cur];
+ if (n > tail) {
+ n -= tail;
+ }
+
if (ret & BDRV_BLOCK_ZERO) {
s->status = post_backing_zero ? BLK_BACKING_FILE : BLK_ZERO;
} else if (ret & BDRV_BLOCK_DATA) {
@@ -2410,8 +2422,10 @@ static int img_convert(int argc, char **argv)
s.src = g_new0(BlockBackend *, s.src_num);
s.src_sectors = g_new(int64_t, s.src_num);
+ s.src_alignment = g_new(int, s.src_num);
for (bs_i = 0; bs_i < s.src_num; bs_i++) {
+ BlockDriverState *src_bs;
s.src[bs_i] = img_open(image_opts, argv[optind + bs_i],
fmt, src_flags, src_writethrough, s.quiet,
force_share);
@@ -2426,6 +2440,13 @@ static int img_convert(int argc, char **argv)
ret = -1;
goto out;
}
+ src_bs = blk_bs(s.src[bs_i]);
+ s.src_alignment[bs_i] = DIV_ROUND_UP(src_bs->bl.request_alignment,
+ BDRV_SECTOR_SIZE);
+ if (!bdrv_get_info(src_bs, &bdi)) {
+ s.src_alignment[bs_i] = MAX(s.src_alignment[bs_i],
+ bdi.cluster_size / BDRV_SECTOR_SIZE);
+ }
s.total_sectors += s.src_sectors[bs_i];
}
@@ -2708,6 +2729,7 @@ out:
g_free(s.src);
}
g_free(s.src_sectors);
+ g_free(s.src_alignment);
fail_getopt:
g_free(options);
diff --git a/tests/qemu-iotests/251 b/tests/qemu-iotests/251
index 7918ba3..294773b 100755
--- a/tests/qemu-iotests/251
+++ b/tests/qemu-iotests/251
@@ -46,8 +46,11 @@ if [ "$IMGOPTSSYNTAX" = "true" ]; then
# We use json:{} filenames here, so we cannot work with additional options.
_unsupported_fmt $IMGFMT
else
- # With VDI, the output is ordered differently. Just disable it.
- _unsupported_fmt vdi
+ # - With VDI, the output is ordered differently. Just disable it.
+ # - VHDX has large clusters; because qemu-img convert tries to
+ # align the requests to the cluster size, the output is ordered
+ # differently, so disable it, too.
+ _unsupported_fmt vdi vhdx
fi