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Diffstat (limited to 'block/qcow2-cluster.c')
-rw-r--r--block/qcow2-cluster.c182
1 files changed, 109 insertions, 73 deletions
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index 179aa2c728..974a4e8656 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -153,7 +153,7 @@ int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t min_size,
/* the L1 position has not yet been updated, so these clusters must
* indeed be completely free */
ret = qcow2_pre_write_overlap_check(bs, 0, new_l1_table_offset,
- new_l1_size2);
+ new_l1_size2, false);
if (ret < 0) {
goto fail;
}
@@ -238,7 +238,7 @@ int qcow2_write_l1_entry(BlockDriverState *bs, int l1_index)
}
ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_ACTIVE_L1,
- s->l1_table_offset + 8 * l1_start_index, sizeof(buf));
+ s->l1_table_offset + 8 * l1_start_index, sizeof(buf), false);
if (ret < 0) {
return ret;
}
@@ -380,8 +380,8 @@ fail:
* as contiguous. (This allows it, for example, to stop at the first compressed
* cluster which may require a different handling)
*/
-static int count_contiguous_clusters(int nb_clusters, int cluster_size,
- uint64_t *l2_slice, uint64_t stop_flags)
+static int count_contiguous_clusters(BlockDriverState *bs, int nb_clusters,
+ int cluster_size, uint64_t *l2_slice, uint64_t stop_flags)
{
int i;
QCow2ClusterType first_cluster_type;
@@ -389,12 +389,12 @@ static int count_contiguous_clusters(int nb_clusters, int cluster_size,
uint64_t first_entry = be64_to_cpu(l2_slice[0]);
uint64_t offset = first_entry & mask;
- if (!offset) {
+ first_cluster_type = qcow2_get_cluster_type(bs, first_entry);
+ if (first_cluster_type == QCOW2_CLUSTER_UNALLOCATED) {
return 0;
}
/* must be allocated */
- first_cluster_type = qcow2_get_cluster_type(first_entry);
assert(first_cluster_type == QCOW2_CLUSTER_NORMAL ||
first_cluster_type == QCOW2_CLUSTER_ZERO_ALLOC);
@@ -412,7 +412,8 @@ static int count_contiguous_clusters(int nb_clusters, int cluster_size,
* Checks how many consecutive unallocated clusters in a given L2
* slice have the same cluster type.
*/
-static int count_contiguous_clusters_unallocated(int nb_clusters,
+static int count_contiguous_clusters_unallocated(BlockDriverState *bs,
+ int nb_clusters,
uint64_t *l2_slice,
QCow2ClusterType wanted_type)
{
@@ -422,7 +423,7 @@ static int count_contiguous_clusters_unallocated(int nb_clusters,
wanted_type == QCOW2_CLUSTER_UNALLOCATED);
for (i = 0; i < nb_clusters; i++) {
uint64_t entry = be64_to_cpu(l2_slice[i]);
- QCow2ClusterType type = qcow2_get_cluster_type(entry);
+ QCow2ClusterType type = qcow2_get_cluster_type(bs, entry);
if (type != wanted_type) {
break;
@@ -489,6 +490,7 @@ static int coroutine_fn do_perform_cow_write(BlockDriverState *bs,
unsigned offset_in_cluster,
QEMUIOVector *qiov)
{
+ BDRVQcow2State *s = bs->opaque;
int ret;
if (qiov->size == 0) {
@@ -496,13 +498,13 @@ static int coroutine_fn do_perform_cow_write(BlockDriverState *bs,
}
ret = qcow2_pre_write_overlap_check(bs, 0,
- cluster_offset + offset_in_cluster, qiov->size);
+ cluster_offset + offset_in_cluster, qiov->size, true);
if (ret < 0) {
return ret;
}
BLKDBG_EVENT(bs->file, BLKDBG_COW_WRITE);
- ret = bdrv_co_pwritev(bs->file, cluster_offset + offset_in_cluster,
+ ret = bdrv_co_pwritev(s->data_file, cluster_offset + offset_in_cluster,
qiov->size, qiov, 0);
if (ret < 0) {
return ret;
@@ -595,7 +597,7 @@ int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
* true */
assert(nb_clusters <= INT_MAX);
- type = qcow2_get_cluster_type(*cluster_offset);
+ type = qcow2_get_cluster_type(bs, *cluster_offset);
if (s->qcow_version < 3 && (type == QCOW2_CLUSTER_ZERO_PLAIN ||
type == QCOW2_CLUSTER_ZERO_ALLOC)) {
qcow2_signal_corruption(bs, true, -1, -1, "Zero cluster entry found"
@@ -606,6 +608,14 @@ int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
}
switch (type) {
case QCOW2_CLUSTER_COMPRESSED:
+ if (has_data_file(bs)) {
+ qcow2_signal_corruption(bs, true, -1, -1, "Compressed cluster "
+ "entry found in image with external data "
+ "file (L2 offset: %#" PRIx64 ", L2 index: "
+ "%#x)", l2_offset, l2_index);
+ ret = -EIO;
+ goto fail;
+ }
/* Compressed clusters can only be processed one by one */
c = 1;
*cluster_offset &= L2E_COMPRESSED_OFFSET_SIZE_MASK;
@@ -613,14 +623,14 @@ int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
case QCOW2_CLUSTER_ZERO_PLAIN:
case QCOW2_CLUSTER_UNALLOCATED:
/* how many empty clusters ? */
- c = count_contiguous_clusters_unallocated(nb_clusters,
+ c = count_contiguous_clusters_unallocated(bs, nb_clusters,
&l2_slice[l2_index], type);
*cluster_offset = 0;
break;
case QCOW2_CLUSTER_ZERO_ALLOC:
case QCOW2_CLUSTER_NORMAL:
/* how many allocated clusters ? */
- c = count_contiguous_clusters(nb_clusters, s->cluster_size,
+ c = count_contiguous_clusters(bs, nb_clusters, s->cluster_size,
&l2_slice[l2_index], QCOW_OFLAG_ZERO);
*cluster_offset &= L2E_OFFSET_MASK;
if (offset_into_cluster(s, *cluster_offset)) {
@@ -632,6 +642,17 @@ int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
ret = -EIO;
goto fail;
}
+ if (has_data_file(bs) && *cluster_offset != offset - offset_in_cluster)
+ {
+ qcow2_signal_corruption(bs, true, -1, -1,
+ "External data file host cluster offset %#"
+ PRIx64 " does not match guest cluster "
+ "offset: %#" PRIx64
+ ", L2 index: %#x)", *cluster_offset,
+ offset - offset_in_cluster, l2_index);
+ ret = -EIO;
+ goto fail;
+ }
break;
default:
abort();
@@ -735,19 +756,16 @@ static int get_cluster_table(BlockDriverState *bs, uint64_t offset,
/*
* alloc_compressed_cluster_offset
*
- * For a given offset of the disk image, return cluster offset in
- * qcow2 file.
- *
- * If the offset is not found, allocate a new compressed cluster.
- *
- * Return the cluster offset if successful,
- * Return 0, otherwise.
+ * For a given offset on the virtual disk, allocate a new compressed cluster
+ * and put the host offset of the cluster into *host_offset. If a cluster is
+ * already allocated at the offset, return an error.
*
+ * Return 0 on success and -errno in error cases
*/
-
-uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
- uint64_t offset,
- int compressed_size)
+int qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
+ uint64_t offset,
+ int compressed_size,
+ uint64_t *host_offset)
{
BDRVQcow2State *s = bs->opaque;
int l2_index, ret;
@@ -755,9 +773,13 @@ uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
int64_t cluster_offset;
int nb_csectors;
+ if (has_data_file(bs)) {
+ return 0;
+ }
+
ret = get_cluster_table(bs, offset, &l2_slice, &l2_index);
if (ret < 0) {
- return 0;
+ return ret;
}
/* Compression can't overwrite anything. Fail if the cluster was already
@@ -765,13 +787,13 @@ uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
cluster_offset = be64_to_cpu(l2_slice[l2_index]);
if (cluster_offset & L2E_OFFSET_MASK) {
qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice);
- return 0;
+ return -EIO;
}
cluster_offset = qcow2_alloc_bytes(bs, compressed_size);
if (cluster_offset < 0) {
qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice);
- return 0;
+ return cluster_offset;
}
nb_csectors = ((cluster_offset + compressed_size - 1) >> 9) -
@@ -789,7 +811,8 @@ uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
l2_slice[l2_index] = cpu_to_be64(cluster_offset);
qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice);
- return cluster_offset;
+ *host_offset = cluster_offset & s->cluster_offset_mask;
+ return 0;
}
static int perform_cow(BlockDriverState *bs, QCowL2Meta *m)
@@ -1013,14 +1036,14 @@ void qcow2_alloc_cluster_abort(BlockDriverState *bs, QCowL2Meta *m)
* write, but require COW to be performed (this includes yet unallocated space,
* which must copy from the backing file)
*/
-static int count_cow_clusters(BDRVQcow2State *s, int nb_clusters,
+static int count_cow_clusters(BlockDriverState *bs, int nb_clusters,
uint64_t *l2_slice, int l2_index)
{
int i;
for (i = 0; i < nb_clusters; i++) {
uint64_t l2_entry = be64_to_cpu(l2_slice[l2_index + i]);
- QCow2ClusterType cluster_type = qcow2_get_cluster_type(l2_entry);
+ QCow2ClusterType cluster_type = qcow2_get_cluster_type(bs, l2_entry);
switch(cluster_type) {
case QCOW2_CLUSTER_NORMAL:
@@ -1108,9 +1131,9 @@ static int handle_dependencies(BlockDriverState *bs, uint64_t guest_offset,
/*
* Checks how many already allocated clusters that don't require a copy on
- * write there are at the given guest_offset (up to *bytes). If
- * *host_offset is not zero, only physically contiguous clusters beginning at
- * this host offset are counted.
+ * write there are at the given guest_offset (up to *bytes). If *host_offset is
+ * not INV_OFFSET, only physically contiguous clusters beginning at this host
+ * offset are counted.
*
* Note that guest_offset may not be cluster aligned. In this case, the
* returned *host_offset points to exact byte referenced by guest_offset and
@@ -1142,8 +1165,8 @@ static int handle_copied(BlockDriverState *bs, uint64_t guest_offset,
trace_qcow2_handle_copied(qemu_coroutine_self(), guest_offset, *host_offset,
*bytes);
- assert(*host_offset == 0 || offset_into_cluster(s, guest_offset)
- == offset_into_cluster(s, *host_offset));
+ assert(*host_offset == INV_OFFSET || offset_into_cluster(s, guest_offset)
+ == offset_into_cluster(s, *host_offset));
/*
* Calculate the number of clusters to look for. We stop at L2 slice
@@ -1165,7 +1188,7 @@ static int handle_copied(BlockDriverState *bs, uint64_t guest_offset,
cluster_offset = be64_to_cpu(l2_slice[l2_index]);
/* Check how many clusters are already allocated and don't need COW */
- if (qcow2_get_cluster_type(cluster_offset) == QCOW2_CLUSTER_NORMAL
+ if (qcow2_get_cluster_type(bs, cluster_offset) == QCOW2_CLUSTER_NORMAL
&& (cluster_offset & QCOW_OFLAG_COPIED))
{
/* If a specific host_offset is required, check it */
@@ -1181,7 +1204,7 @@ static int handle_copied(BlockDriverState *bs, uint64_t guest_offset,
goto out;
}
- if (*host_offset != 0 && !offset_matches) {
+ if (*host_offset != INV_OFFSET && !offset_matches) {
*bytes = 0;
ret = 0;
goto out;
@@ -1189,7 +1212,7 @@ static int handle_copied(BlockDriverState *bs, uint64_t guest_offset,
/* We keep all QCOW_OFLAG_COPIED clusters */
keep_clusters =
- count_contiguous_clusters(nb_clusters, s->cluster_size,
+ count_contiguous_clusters(bs, nb_clusters, s->cluster_size,
&l2_slice[l2_index],
QCOW_OFLAG_COPIED | QCOW_OFLAG_ZERO);
assert(keep_clusters <= nb_clusters);
@@ -1224,10 +1247,10 @@ out:
* contain the number of clusters that have been allocated and are contiguous
* in the image file.
*
- * If *host_offset is non-zero, it specifies the offset in the image file at
- * which the new clusters must start. *nb_clusters can be 0 on return in this
- * case if the cluster at host_offset is already in use. If *host_offset is
- * zero, the clusters can be allocated anywhere in the image file.
+ * If *host_offset is not INV_OFFSET, it specifies the offset in the image file
+ * at which the new clusters must start. *nb_clusters can be 0 on return in
+ * this case if the cluster at host_offset is already in use. If *host_offset
+ * is INV_OFFSET, the clusters can be allocated anywhere in the image file.
*
* *host_offset is updated to contain the offset into the image file at which
* the first allocated cluster starts.
@@ -1244,9 +1267,16 @@ static int do_alloc_cluster_offset(BlockDriverState *bs, uint64_t guest_offset,
trace_qcow2_do_alloc_clusters_offset(qemu_coroutine_self(), guest_offset,
*host_offset, *nb_clusters);
+ if (has_data_file(bs)) {
+ assert(*host_offset == INV_OFFSET ||
+ *host_offset == start_of_cluster(s, guest_offset));
+ *host_offset = start_of_cluster(s, guest_offset);
+ return 0;
+ }
+
/* Allocate new clusters */
trace_qcow2_cluster_alloc_phys(qemu_coroutine_self());
- if (*host_offset == 0) {
+ if (*host_offset == INV_OFFSET) {
int64_t cluster_offset =
qcow2_alloc_clusters(bs, *nb_clusters * s->cluster_size);
if (cluster_offset < 0) {
@@ -1266,8 +1296,8 @@ static int do_alloc_cluster_offset(BlockDriverState *bs, uint64_t guest_offset,
/*
* Allocates new clusters for an area that either is yet unallocated or needs a
- * copy on write. If *host_offset is non-zero, clusters are only allocated if
- * the new allocation can match the specified host offset.
+ * copy on write. If *host_offset is not INV_OFFSET, clusters are only
+ * allocated if the new allocation can match the specified host offset.
*
* Note that guest_offset may not be cluster aligned. In this case, the
* returned *host_offset points to exact byte referenced by guest_offset and
@@ -1295,7 +1325,7 @@ static int handle_alloc(BlockDriverState *bs, uint64_t guest_offset,
int ret;
bool keep_old_clusters = false;
- uint64_t alloc_cluster_offset = 0;
+ uint64_t alloc_cluster_offset = INV_OFFSET;
trace_qcow2_handle_alloc(qemu_coroutine_self(), guest_offset, *host_offset,
*bytes);
@@ -1324,7 +1354,7 @@ static int handle_alloc(BlockDriverState *bs, uint64_t guest_offset,
if (entry & QCOW_OFLAG_COMPRESSED) {
nb_clusters = 1;
} else {
- nb_clusters = count_cow_clusters(s, nb_clusters, l2_slice, l2_index);
+ nb_clusters = count_cow_clusters(bs, nb_clusters, l2_slice, l2_index);
}
/* This function is only called when there were no non-COW clusters, so if
@@ -1332,9 +1362,9 @@ static int handle_alloc(BlockDriverState *bs, uint64_t guest_offset,
* wrong with our code. */
assert(nb_clusters > 0);
- if (qcow2_get_cluster_type(entry) == QCOW2_CLUSTER_ZERO_ALLOC &&
+ if (qcow2_get_cluster_type(bs, entry) == QCOW2_CLUSTER_ZERO_ALLOC &&
(entry & QCOW_OFLAG_COPIED) &&
- (!*host_offset ||
+ (*host_offset == INV_OFFSET ||
start_of_cluster(s, *host_offset) == (entry & L2E_OFFSET_MASK)))
{
int preallocated_nb_clusters;
@@ -1352,7 +1382,7 @@ static int handle_alloc(BlockDriverState *bs, uint64_t guest_offset,
* would be fine, too, but count_cow_clusters() above has limited
* nb_clusters already to a range of COW clusters */
preallocated_nb_clusters =
- count_contiguous_clusters(nb_clusters, s->cluster_size,
+ count_contiguous_clusters(bs, nb_clusters, s->cluster_size,
&l2_slice[l2_index], QCOW_OFLAG_COPIED);
assert(preallocated_nb_clusters > 0);
@@ -1366,9 +1396,10 @@ static int handle_alloc(BlockDriverState *bs, uint64_t guest_offset,
qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice);
- if (!alloc_cluster_offset) {
+ if (alloc_cluster_offset == INV_OFFSET) {
/* Allocate, if necessary at a given offset in the image file */
- alloc_cluster_offset = start_of_cluster(s, *host_offset);
+ alloc_cluster_offset = *host_offset == INV_OFFSET ? INV_OFFSET :
+ start_of_cluster(s, *host_offset);
ret = do_alloc_cluster_offset(bs, guest_offset, &alloc_cluster_offset,
&nb_clusters);
if (ret < 0) {
@@ -1381,16 +1412,7 @@ static int handle_alloc(BlockDriverState *bs, uint64_t guest_offset,
return 0;
}
- /* !*host_offset would overwrite the image header and is reserved for
- * "no host offset preferred". If 0 was a valid host offset, it'd
- * trigger the following overlap check; do that now to avoid having an
- * invalid value in *host_offset. */
- if (!alloc_cluster_offset) {
- ret = qcow2_pre_write_overlap_check(bs, 0, alloc_cluster_offset,
- nb_clusters * s->cluster_size);
- assert(ret < 0);
- goto fail;
- }
+ assert(alloc_cluster_offset != INV_OFFSET);
}
/*
@@ -1482,14 +1504,14 @@ int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset,
again:
start = offset;
remaining = *bytes;
- cluster_offset = 0;
- *host_offset = 0;
+ cluster_offset = INV_OFFSET;
+ *host_offset = INV_OFFSET;
cur_bytes = 0;
*m = NULL;
while (true) {
- if (!*host_offset) {
+ if (*host_offset == INV_OFFSET && cluster_offset != INV_OFFSET) {
*host_offset = start_of_cluster(s, cluster_offset);
}
@@ -1497,7 +1519,10 @@ again:
start += cur_bytes;
remaining -= cur_bytes;
- cluster_offset += cur_bytes;
+
+ if (cluster_offset != INV_OFFSET) {
+ cluster_offset += cur_bytes;
+ }
if (remaining == 0) {
break;
@@ -1569,7 +1594,7 @@ again:
*bytes -= remaining;
assert(*bytes > 0);
- assert(*host_offset != 0);
+ assert(*host_offset != INV_OFFSET);
return 0;
}
@@ -1616,7 +1641,7 @@ static int discard_in_l2_slice(BlockDriverState *bs, uint64_t offset,
* If full_discard is true, the sector should not read back as zeroes,
* but rather fall through to the backing file.
*/
- switch (qcow2_get_cluster_type(old_l2_entry)) {
+ switch (qcow2_get_cluster_type(bs, old_l2_entry)) {
case QCOW2_CLUSTER_UNALLOCATED:
if (full_discard || !bs->backing) {
continue;
@@ -1729,7 +1754,7 @@ static int zero_in_l2_slice(BlockDriverState *bs, uint64_t offset,
* Minimize L2 changes if the cluster already reads back as
* zeroes with correct allocation.
*/
- cluster_type = qcow2_get_cluster_type(old_offset);
+ cluster_type = qcow2_get_cluster_type(bs, old_offset);
if (cluster_type == QCOW2_CLUSTER_ZERO_PLAIN ||
(cluster_type == QCOW2_CLUSTER_ZERO_ALLOC && !unmap)) {
continue;
@@ -1758,6 +1783,16 @@ int qcow2_cluster_zeroize(BlockDriverState *bs, uint64_t offset,
int64_t cleared;
int ret;
+ /* If we have to stay in sync with an external data file, zero out
+ * s->data_file first. */
+ if (data_file_is_raw(bs)) {
+ assert(has_data_file(bs));
+ ret = bdrv_co_pwrite_zeroes(s->data_file, offset, bytes, flags);
+ if (ret < 0) {
+ return ret;
+ }
+ }
+
/* Caller must pass aligned values, except at image end */
assert(QEMU_IS_ALIGNED(offset, s->cluster_size));
assert(QEMU_IS_ALIGNED(end_offset, s->cluster_size) ||
@@ -1871,7 +1906,7 @@ static int expand_zero_clusters_in_l1(BlockDriverState *bs, uint64_t *l1_table,
uint64_t l2_entry = be64_to_cpu(l2_slice[j]);
int64_t offset = l2_entry & L2E_OFFSET_MASK;
QCow2ClusterType cluster_type =
- qcow2_get_cluster_type(l2_entry);
+ qcow2_get_cluster_type(bs, l2_entry);
if (cluster_type != QCOW2_CLUSTER_ZERO_PLAIN &&
cluster_type != QCOW2_CLUSTER_ZERO_ALLOC) {
@@ -1925,7 +1960,7 @@ static int expand_zero_clusters_in_l1(BlockDriverState *bs, uint64_t *l1_table,
}
ret = qcow2_pre_write_overlap_check(bs, 0, offset,
- s->cluster_size);
+ s->cluster_size, true);
if (ret < 0) {
if (cluster_type == QCOW2_CLUSTER_ZERO_PLAIN) {
qcow2_free_clusters(bs, offset, s->cluster_size,
@@ -1934,7 +1969,8 @@ static int expand_zero_clusters_in_l1(BlockDriverState *bs, uint64_t *l1_table,
goto fail;
}
- ret = bdrv_pwrite_zeroes(bs->file, offset, s->cluster_size, 0);
+ ret = bdrv_pwrite_zeroes(s->data_file, offset,
+ s->cluster_size, 0);
if (ret < 0) {
if (cluster_type == QCOW2_CLUSTER_ZERO_PLAIN) {
qcow2_free_clusters(bs, offset, s->cluster_size,
@@ -1961,7 +1997,7 @@ static int expand_zero_clusters_in_l1(BlockDriverState *bs, uint64_t *l1_table,
if (l2_dirty) {
ret = qcow2_pre_write_overlap_check(
bs, QCOW2_OL_INACTIVE_L2 | QCOW2_OL_ACTIVE_L2,
- slice_offset, slice_size2);
+ slice_offset, slice_size2, false);
if (ret < 0) {
goto fail;
}
generated by cgit v1.2.3 (git 2.26.2) at 2025-01-19 01:12:47 +0000