@@ -404,12 +404,12 @@ static void mark_request_serialising(BdrvTrackedRequest *req, uint64_t align)
}
/**
- * Round a region to cluster boundaries
+ * Round a region to cluster boundaries (sector-based)
*/
-void bdrv_round_to_clusters(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors,
- int64_t *cluster_sector_num,
- int *cluster_nb_sectors)
+void bdrv_round_sectors_to_clusters(BlockDriverState *bs,
+ int64_t sector_num, int nb_sectors,
+ int64_t *cluster_sector_num,
+ int *cluster_nb_sectors)
{
BlockDriverInfo bdi;
@@ -424,6 +424,26 @@ void bdrv_round_to_clusters(BlockDriverState *bs,
}
}
+/**
+ * Round a region to cluster boundaries
+ */
+void bdrv_round_to_clusters(BlockDriverState *bs,
+ int64_t offset, unsigned int bytes,
+ int64_t *cluster_offset,
+ unsigned int *cluster_bytes)
+{
+ BlockDriverInfo bdi;
+
+ if (bdrv_get_info(bs, &bdi) < 0 || bdi.cluster_size == 0) {
+ *cluster_offset = offset;
+ *cluster_bytes = bytes;
+ } else {
+ int64_t c = bdi.cluster_size;
+ *cluster_offset = QEMU_ALIGN_DOWN(offset, c);
+ *cluster_bytes = QEMU_ALIGN_UP(offset - *cluster_offset + bytes, c);
+ }
+}
+
static int bdrv_get_cluster_size(BlockDriverState *bs)
{
BlockDriverInfo bdi;
@@ -861,7 +881,7 @@ emulate_flags:
}
static int coroutine_fn bdrv_co_do_copy_on_readv(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
+ int64_t offset, unsigned int bytes, QEMUIOVector *qiov)
{
/* Perform I/O through a temporary buffer so that users who scribble over
* their read buffer while the operation is in progress do not end up
@@ -873,21 +893,20 @@ static int coroutine_fn bdrv_co_do_copy_on_readv(BlockDriverState *bs,
BlockDriver *drv = bs->drv;
struct iovec iov;
QEMUIOVector bounce_qiov;
- int64_t cluster_sector_num;
- int cluster_nb_sectors;
+ int64_t cluster_offset;
+ unsigned int cluster_bytes;
size_t skip_bytes;
int ret;
/* Cover entire cluster so no additional backing file I/O is required when
* allocating cluster in the image file.
*/
- bdrv_round_to_clusters(bs, sector_num, nb_sectors,
- &cluster_sector_num, &cluster_nb_sectors);
+ bdrv_round_to_clusters(bs, offset, bytes, &cluster_offset, &cluster_bytes);
- trace_bdrv_co_do_copy_on_readv(bs, sector_num, nb_sectors,
- cluster_sector_num, cluster_nb_sectors);
+ trace_bdrv_co_do_copy_on_readv(bs, offset, bytes,
+ cluster_offset, cluster_bytes);
- iov.iov_len = cluster_nb_sectors * BDRV_SECTOR_SIZE;
+ iov.iov_len = cluster_bytes;
iov.iov_base = bounce_buffer = qemu_try_blockalign(bs, iov.iov_len);
if (bounce_buffer == NULL) {
ret = -ENOMEM;
@@ -896,8 +915,7 @@ static int coroutine_fn bdrv_co_do_copy_on_readv(BlockDriverState *bs,
qemu_iovec_init_external(&bounce_qiov, &iov, 1);
- ret = bdrv_driver_preadv(bs, cluster_sector_num * BDRV_SECTOR_SIZE,
- cluster_nb_sectors * BDRV_SECTOR_SIZE,
+ ret = bdrv_driver_preadv(bs, cluster_offset, cluster_bytes,
&bounce_qiov, 0);
if (ret < 0) {
goto err;
@@ -905,16 +923,12 @@ static int coroutine_fn bdrv_co_do_copy_on_readv(BlockDriverState *bs,
if (drv->bdrv_co_pwrite_zeroes &&
buffer_is_zero(bounce_buffer, iov.iov_len)) {
- ret = bdrv_co_do_pwrite_zeroes(bs,
- cluster_sector_num * BDRV_SECTOR_SIZE,
- cluster_nb_sectors * BDRV_SECTOR_SIZE,
- 0);
+ ret = bdrv_co_do_pwrite_zeroes(bs, cluster_offset, cluster_bytes, 0);
} else {
/* This does not change the data on the disk, it is not necessary
* to flush even in cache=writethrough mode.
*/
- ret = bdrv_driver_pwritev(bs, cluster_sector_num * BDRV_SECTOR_SIZE,
- cluster_nb_sectors * BDRV_SECTOR_SIZE,
+ ret = bdrv_driver_pwritev(bs, cluster_offset, cluster_bytes,
&bounce_qiov, 0);
}
@@ -926,9 +940,8 @@ static int coroutine_fn bdrv_co_do_copy_on_readv(BlockDriverState *bs,
goto err;
}
- skip_bytes = (sector_num - cluster_sector_num) * BDRV_SECTOR_SIZE;
- qemu_iovec_from_buf(qiov, 0, bounce_buffer + skip_bytes,
- nb_sectors * BDRV_SECTOR_SIZE);
+ skip_bytes = offset - cluster_offset;
+ qemu_iovec_from_buf(qiov, 0, bounce_buffer + skip_bytes, bytes);
err:
qemu_vfree(bounce_buffer);
@@ -977,7 +990,7 @@ static int coroutine_fn bdrv_aligned_preadv(BlockDriverState *bs,
}
if (!ret || pnum != nb_sectors) {
- ret = bdrv_co_do_copy_on_readv(bs, sector_num, nb_sectors, qiov);
+ ret = bdrv_co_do_copy_on_readv(bs, offset, bytes, qiov);
goto out;
}
}
@@ -186,8 +186,9 @@ static int mirror_cow_align(MirrorBlockJob *s,
need_cow |= !test_bit((*sector_num + *nb_sectors - 1) / chunk_sectors,
s->cow_bitmap);
if (need_cow) {
- bdrv_round_to_clusters(blk_bs(s->target), *sector_num, *nb_sectors,
- &align_sector_num, &align_nb_sectors);
+ bdrv_round_sectors_to_clusters(blk_bs(s->target), *sector_num,
+ *nb_sectors, &align_sector_num,
+ &align_nb_sectors);
}
if (align_nb_sectors > max_sectors) {
@@ -386,8 +387,9 @@ static uint64_t coroutine_fn mirror_iteration(MirrorBlockJob *s)
} else if (ret >= 0 && !(ret & BDRV_BLOCK_DATA)) {
int64_t target_sector_num;
int target_nb_sectors;
- bdrv_round_to_clusters(blk_bs(s->target), sector_num, io_sectors,
- &target_sector_num, &target_nb_sectors);
+ bdrv_round_sectors_to_clusters(blk_bs(s->target), sector_num,
+ io_sectors, &target_sector_num,
+ &target_nb_sectors);
if (target_sector_num == sector_num &&
target_nb_sectors == io_sectors) {
mirror_method = ret & BDRV_BLOCK_ZERO ?
@@ -401,10 +401,14 @@ int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num,
const uint8_t *buf, int nb_sectors);
int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi);
ImageInfoSpecific *bdrv_get_specific_info(BlockDriverState *bs);
+void bdrv_round_sectors_to_clusters(BlockDriverState *bs,
+ int64_t sector_num, int nb_sectors,
+ int64_t *cluster_sector_num,
+ int *cluster_nb_sectors);
void bdrv_round_to_clusters(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors,
- int64_t *cluster_sector_num,
- int *cluster_nb_sectors);
+ int64_t offset, unsigned int bytes,
+ int64_t *cluster_offset,
+ unsigned int *cluster_bytes);
const char *bdrv_get_encrypted_filename(BlockDriverState *bs);
void bdrv_get_backing_filename(BlockDriverState *bs,
In a first step to convert the common I/O path to work on bytes rather than sectors, this converts the copy-on-read logic that is used by bdrv_aligned_preadv(). Signed-off-by: Kevin Wolf <kwolf@redhat.com> --- block/io.c | 63 +++++++++++++++++++++++++++++++-------------------- block/mirror.c | 10 ++++---- include/block/block.h | 10 +++++--- 3 files changed, 51 insertions(+), 32 deletions(-)