From: Hu Tao <hu...@cn.fujitsu.com>
n_start can be actually calculated from offset. The number of
sectors to be allocated(n_end - n_start) can be passed in in
num. By removing n_start and n_end, we can save two parameters.
The side effect is there is a bug in qcow2.c:preallocate() that
passes incorrect n_start to qcow2_alloc_cluster_offset() is
fixed. The bug can be triggerred by a larger cluster size than
the default value(65536), for example:
./qemu-img create -f qcow2 \
-o 'cluster_size=131072,preallocation=metadata' file.img 4G
Signed-off-by: Hu Tao <hu...@cn.fujitsu.com>
Reviewed-by: Max Reitz <mre...@redhat.com>
Reviewed-by: Benoit Canet <ben...@irqsave.net>
Signed-off-by: Kevin Wolf <kw...@redhat.com>
---
block/qcow2-cluster.c | 14 ++++++--------
block/qcow2.c | 13 +++++++------
block/qcow2.h | 2 +-
trace-events | 2 +-
4 files changed, 15 insertions(+), 16 deletions(-)
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index 8534084..c57f39d 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -1182,7 +1182,7 @@ fail:
* Return 0 on success and -errno in error cases
*/
int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset,
- int n_start, int n_end, int *num, uint64_t *host_offset, QCowL2Meta **m)
+ int *num, uint64_t *host_offset, QCowL2Meta **m)
{
BDRVQcowState *s = bs->opaque;
uint64_t start, remaining;
@@ -1190,15 +1190,13 @@ int qcow2_alloc_cluster_offset(BlockDriverState *bs,
uint64_t offset,
uint64_t cur_bytes;
int ret;
- trace_qcow2_alloc_clusters_offset(qemu_coroutine_self(), offset,
- n_start, n_end);
+ trace_qcow2_alloc_clusters_offset(qemu_coroutine_self(), offset, *num);
- assert(n_start * BDRV_SECTOR_SIZE == offset_into_cluster(s, offset));
- offset = start_of_cluster(s, offset);
+ assert((offset & ~BDRV_SECTOR_MASK) == 0);
again:
- start = offset + (n_start << BDRV_SECTOR_BITS);
- remaining = (n_end - n_start) << BDRV_SECTOR_BITS;
+ start = offset;
+ remaining = *num << BDRV_SECTOR_BITS;
cluster_offset = 0;
*host_offset = 0;
cur_bytes = 0;
@@ -1284,7 +1282,7 @@ again:
}
}
- *num = (n_end - n_start) - (remaining >> BDRV_SECTOR_BITS);
+ *num -= remaining >> BDRV_SECTOR_BITS;
assert(*num > 0);
assert(*host_offset != 0);
diff --git a/block/qcow2.c b/block/qcow2.c
index 99a1ad1..a274d5f 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -1000,7 +1000,6 @@ static coroutine_fn int qcow2_co_writev(BlockDriverState
*bs,
{
BDRVQcowState *s = bs->opaque;
int index_in_cluster;
- int n_end;
int ret;
int cur_nr_sectors; /* number of sectors in current iteration */
uint64_t cluster_offset;
@@ -1024,14 +1023,16 @@ static coroutine_fn int
qcow2_co_writev(BlockDriverState *bs,
trace_qcow2_writev_start_part(qemu_coroutine_self());
index_in_cluster = sector_num & (s->cluster_sectors - 1);
- n_end = index_in_cluster + remaining_sectors;
+ cur_nr_sectors = remaining_sectors;
if (s->crypt_method &&
- n_end > QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors) {
- n_end = QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors;
+ cur_nr_sectors >
+ QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors - index_in_cluster) {
+ cur_nr_sectors =
+ QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors -
index_in_cluster;
}
ret = qcow2_alloc_cluster_offset(bs, sector_num << 9,
- index_in_cluster, n_end, &cur_nr_sectors, &cluster_offset,
&l2meta);
+ &cur_nr_sectors, &cluster_offset, &l2meta);
if (ret < 0) {
goto fail;
}
@@ -1408,7 +1409,7 @@ static int preallocate(BlockDriverState *bs)
while (nb_sectors) {
num = MIN(nb_sectors, INT_MAX >> 9);
- ret = qcow2_alloc_cluster_offset(bs, offset, 0, num, &num,
+ ret = qcow2_alloc_cluster_offset(bs, offset, &num,
&host_offset, &meta);
if (ret < 0) {
return ret;
diff --git a/block/qcow2.h b/block/qcow2.h
index b5b7d13..0b0eac8 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -468,7 +468,7 @@ void qcow2_encrypt_sectors(BDRVQcowState *s, int64_t
sector_num,
int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
int *num, uint64_t *cluster_offset);
int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset,
- int n_start, int n_end, int *num, uint64_t *host_offset, QCowL2Meta **m);
+ int *num, uint64_t *host_offset, QCowL2Meta **m);
uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
uint64_t offset,
int compressed_size);
diff --git a/trace-events b/trace-events
index 1b668d1..ab11f97 100644
--- a/trace-events
+++ b/trace-events
@@ -495,7 +495,7 @@ qcow2_writev_done_part(void *co, int cur_nr_sectors) "co %p
cur_nr_sectors %d"
qcow2_writev_data(void *co, uint64_t offset) "co %p offset %" PRIx64
# block/qcow2-cluster.c
-qcow2_alloc_clusters_offset(void *co, uint64_t offset, int n_start, int n_end)
"co %p offet %" PRIx64 " n_start %d n_end %d"
+qcow2_alloc_clusters_offset(void *co, uint64_t offset, int num) "co %p offet
%" PRIx64 " num %d"
qcow2_handle_copied(void *co, uint64_t guest_offset, uint64_t host_offset,
uint64_t bytes) "co %p guest_offet %" PRIx64 " host_offset %" PRIx64 " bytes %"
PRIx64
qcow2_handle_alloc(void *co, uint64_t guest_offset, uint64_t host_offset,
uint64_t bytes) "co %p guest_offet %" PRIx64 " host_offset %" PRIx64 " bytes %"
PRIx64
qcow2_do_alloc_clusters_offset(void *co, uint64_t guest_offset, uint64_t
host_offset, int nb_clusters) "co %p guest_offet %" PRIx64 " host_offset %"
PRIx64 " nb_clusters %d"
--
1.8.1.4
