We are gradually moving away from sector-based interfaces, towards
byte-based. Make the change for the internals of the qcow
driver write function, by iterating over offset/bytes instead of
sector_num/nb_sectors, and with a rename of index_in_cluster and
repurposing of n to track bytes instead of sectors.
A later patch will then switch the qcow driver as a whole over
to byte-based operation.
Signed-off-by: Eric Blake <ebl...@redhat.com>
Reviewed-by: Jeff Cody <jc...@redhat.com>
---
v2: prefer 64-bit * over 23-bit <<, rename variable for legibility [Kevin]
---
block/qcow.c | 36 +++++++++++++++++-------------------
1 file changed, 17 insertions(+), 19 deletions(-)
diff --git a/block/qcow.c b/block/qcow.c
index 175f1c8f848..d2af7b8e025 100644
--- a/block/qcow.c
+++ b/block/qcow.c
@@ -724,13 +724,15 @@ static coroutine_fn int qcow_co_writev(BlockDriverState
*bs, int64_t sector_num,
int flags)
{
BDRVQcowState *s = bs->opaque;
- int index_in_cluster;
+ int offset_in_cluster;
uint64_t cluster_offset;
int ret = 0, n;
struct iovec hd_iov;
QEMUIOVector hd_qiov;
uint8_t *buf;
void *orig_buf;
+ int64_t offset = sector_num * BDRV_SECTOR_SIZE;
+ int64_t bytes = nb_sectors * BDRV_SECTOR_SIZE;
assert(!flags);
s->cluster_cache_offset = -1; /* disable compressed cache */
@@ -750,16 +752,14 @@ static coroutine_fn int qcow_co_writev(BlockDriverState
*bs, int64_t sector_num,
qemu_co_mutex_lock(&s->lock);
- while (nb_sectors != 0) {
-
- index_in_cluster = sector_num & (s->cluster_sectors - 1);
- n = s->cluster_sectors - index_in_cluster;
- if (n > nb_sectors) {
- n = nb_sectors;
+ while (bytes != 0) {
+ offset_in_cluster = offset & (s->cluster_size - 1);
+ n = s->cluster_size - offset_in_cluster;
+ if (n > bytes) {
+ n = bytes;
}
- ret = get_cluster_offset(bs, sector_num << 9, 1, 0,
- index_in_cluster << 9,
- (index_in_cluster + n) << 9, &cluster_offset);
+ ret = get_cluster_offset(bs, offset, 1, 0, offset_in_cluster,
+ offset_in_cluster + n, &cluster_offset);
if (ret < 0) {
break;
}
@@ -769,30 +769,28 @@ static coroutine_fn int qcow_co_writev(BlockDriverState
*bs, int64_t sector_num,
}
if (bs->encrypted) {
assert(s->crypto);
- if (qcrypto_block_encrypt(s->crypto, sector_num * BDRV_SECTOR_SIZE,
- buf, n * BDRV_SECTOR_SIZE, NULL) < 0) {
+ if (qcrypto_block_encrypt(s->crypto, offset, buf, n, NULL) < 0) {
ret = -EIO;
break;
}
}
hd_iov.iov_base = (void *)buf;
- hd_iov.iov_len = n * 512;
+ hd_iov.iov_len = n;
qemu_iovec_init_external(&hd_qiov, &hd_iov, 1);
qemu_co_mutex_unlock(&s->lock);
BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO);
- ret = bdrv_co_writev(bs->file,
- (cluster_offset >> 9) + index_in_cluster,
- n, &hd_qiov);
+ ret = bdrv_co_pwritev(bs->file, cluster_offset + offset_in_cluster,
+ n, &hd_qiov, 0);
qemu_co_mutex_lock(&s->lock);
if (ret < 0) {
break;
}
ret = 0;
- nb_sectors -= n;
- sector_num += n;
- buf += n * 512;
+ bytes -= n;
+ offset += n;
+ buf += n;
}
qemu_co_mutex_unlock(&s->lock);
--
2.14.4
