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-rw-r--r--block/qcow2-cluster.c519
1 files changed, 276 insertions, 243 deletions
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index 3a979bcd82..e406b0f3b9 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -195,20 +195,26 @@ int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t min_size,
/*
* l2_load
*
- * Loads a L2 table into memory. If the table is in the cache, the cache
- * is used; otherwise the L2 table is loaded from the image file.
+ * @bs: The BlockDriverState
+ * @offset: A guest offset, used to calculate what slice of the L2
+ * table to load.
+ * @l2_offset: Offset to the L2 table in the image file.
+ * @l2_slice: Location to store the pointer to the L2 slice.
*
- * Returns a pointer to the L2 table on success, or NULL if the read from
- * the image file failed.
+ * Loads a L2 slice into memory (L2 slices are the parts of L2 tables
+ * that are loaded by the qcow2 cache). If the slice is in the cache,
+ * the cache is used; otherwise the L2 slice is loaded from the image
+ * file.
*/
-
-static int l2_load(BlockDriverState *bs, uint64_t l2_offset,
- uint64_t **l2_table)
+static int l2_load(BlockDriverState *bs, uint64_t offset,
+ uint64_t l2_offset, uint64_t **l2_slice)
{
BDRVQcow2State *s = bs->opaque;
+ int start_of_slice = sizeof(uint64_t) *
+ (offset_to_l2_index(s, offset) - offset_to_l2_slice_index(s, offset));
- return qcow2_cache_get(bs, s->l2_table_cache, l2_offset,
- (void **)l2_table);
+ return qcow2_cache_get(bs, s->l2_table_cache, l2_offset + start_of_slice,
+ (void **)l2_slice);
}
/*
@@ -257,11 +263,12 @@ int qcow2_write_l1_entry(BlockDriverState *bs, int l1_index)
*
*/
-static int l2_allocate(BlockDriverState *bs, int l1_index, uint64_t **table)
+static int l2_allocate(BlockDriverState *bs, int l1_index)
{
BDRVQcow2State *s = bs->opaque;
uint64_t old_l2_offset;
- uint64_t *l2_table = NULL;
+ uint64_t *l2_slice = NULL;
+ unsigned slice, slice_size2, n_slices;
int64_t l2_offset;
int ret;
@@ -292,39 +299,47 @@ static int l2_allocate(BlockDriverState *bs, int l1_index, uint64_t **table)
/* allocate a new entry in the l2 cache */
+ slice_size2 = s->l2_slice_size * sizeof(uint64_t);
+ n_slices = s->cluster_size / slice_size2;
+
trace_qcow2_l2_allocate_get_empty(bs, l1_index);
- ret = qcow2_cache_get_empty(bs, s->l2_table_cache, l2_offset, (void**) table);
- if (ret < 0) {
- goto fail;
- }
+ for (slice = 0; slice < n_slices; slice++) {
+ ret = qcow2_cache_get_empty(bs, s->l2_table_cache,
+ l2_offset + slice * slice_size2,
+ (void **) &l2_slice);
+ if (ret < 0) {
+ goto fail;
+ }
- l2_table = *table;
+ if ((old_l2_offset & L1E_OFFSET_MASK) == 0) {
+ /* if there was no old l2 table, clear the new slice */
+ memset(l2_slice, 0, slice_size2);
+ } else {
+ uint64_t *old_slice;
+ uint64_t old_l2_slice_offset =
+ (old_l2_offset & L1E_OFFSET_MASK) + slice * slice_size2;
+
+ /* if there was an old l2 table, read a slice from the disk */
+ BLKDBG_EVENT(bs->file, BLKDBG_L2_ALLOC_COW_READ);
+ ret = qcow2_cache_get(bs, s->l2_table_cache, old_l2_slice_offset,
+ (void **) &old_slice);
+ if (ret < 0) {
+ goto fail;
+ }
- if ((old_l2_offset & L1E_OFFSET_MASK) == 0) {
- /* if there was no old l2 table, clear the new table */
- memset(l2_table, 0, s->l2_size * sizeof(uint64_t));
- } else {
- uint64_t* old_table;
+ memcpy(l2_slice, old_slice, slice_size2);
- /* if there was an old l2 table, read it from the disk */
- BLKDBG_EVENT(bs->file, BLKDBG_L2_ALLOC_COW_READ);
- ret = qcow2_cache_get(bs, s->l2_table_cache,
- old_l2_offset & L1E_OFFSET_MASK,
- (void**) &old_table);
- if (ret < 0) {
- goto fail;
+ qcow2_cache_put(s->l2_table_cache, (void **) &old_slice);
}
- memcpy(l2_table, old_table, s->cluster_size);
+ /* write the l2 slice to the file */
+ BLKDBG_EVENT(bs->file, BLKDBG_L2_ALLOC_WRITE);
- qcow2_cache_put(bs, s->l2_table_cache, (void **) &old_table);
+ trace_qcow2_l2_allocate_write_l2(bs, l1_index);
+ qcow2_cache_entry_mark_dirty(s->l2_table_cache, l2_slice);
+ qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice);
}
- /* write the l2 table to the file */
- BLKDBG_EVENT(bs->file, BLKDBG_L2_ALLOC_WRITE);
-
- trace_qcow2_l2_allocate_write_l2(bs, l1_index);
- qcow2_cache_entry_mark_dirty(bs, s->l2_table_cache, l2_table);
ret = qcow2_cache_flush(bs, s->l2_table_cache);
if (ret < 0) {
goto fail;
@@ -338,14 +353,13 @@ static int l2_allocate(BlockDriverState *bs, int l1_index, uint64_t **table)
goto fail;
}
- *table = l2_table;
trace_qcow2_l2_allocate_done(bs, l1_index, 0);
return 0;
fail:
trace_qcow2_l2_allocate_done(bs, l1_index, ret);
- if (l2_table != NULL) {
- qcow2_cache_put(bs, s->l2_table_cache, (void**) table);
+ if (l2_slice != NULL) {
+ qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice);
}
s->l1_table[l1_index] = old_l2_offset;
if (l2_offset > 0) {
@@ -356,19 +370,19 @@ fail:
}
/*
- * Checks how many clusters in a given L2 table are contiguous in the image
+ * Checks how many clusters in a given L2 slice are contiguous in the image
* file. As soon as one of the flags in the bitmask stop_flags changes compared
* to the first cluster, the search is stopped and the cluster is not counted
* 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_table, uint64_t stop_flags)
+ uint64_t *l2_slice, uint64_t stop_flags)
{
int i;
QCow2ClusterType first_cluster_type;
uint64_t mask = stop_flags | L2E_OFFSET_MASK | QCOW_OFLAG_COMPRESSED;
- uint64_t first_entry = be64_to_cpu(l2_table[0]);
+ uint64_t first_entry = be64_to_cpu(l2_slice[0]);
uint64_t offset = first_entry & mask;
if (!offset) {
@@ -381,7 +395,7 @@ static int count_contiguous_clusters(int nb_clusters, int cluster_size,
first_cluster_type == QCOW2_CLUSTER_ZERO_ALLOC);
for (i = 0; i < nb_clusters; i++) {
- uint64_t l2_entry = be64_to_cpu(l2_table[i]) & mask;
+ uint64_t l2_entry = be64_to_cpu(l2_slice[i]) & mask;
if (offset + (uint64_t) i * cluster_size != l2_entry) {
break;
}
@@ -392,10 +406,10 @@ static int count_contiguous_clusters(int nb_clusters, int cluster_size,
/*
* Checks how many consecutive unallocated clusters in a given L2
- * table have the same cluster type.
+ * slice have the same cluster type.
*/
static int count_contiguous_clusters_unallocated(int nb_clusters,
- uint64_t *l2_table,
+ uint64_t *l2_slice,
QCow2ClusterType wanted_type)
{
int i;
@@ -403,7 +417,7 @@ static int count_contiguous_clusters_unallocated(int nb_clusters,
assert(wanted_type == QCOW2_CLUSTER_ZERO_PLAIN ||
wanted_type == QCOW2_CLUSTER_UNALLOCATED);
for (i = 0; i < nb_clusters; i++) {
- uint64_t entry = be64_to_cpu(l2_table[i]);
+ uint64_t entry = be64_to_cpu(l2_slice[i]);
QCow2ClusterType type = qcow2_get_cluster_type(entry);
if (type != wanted_type) {
@@ -515,8 +529,8 @@ int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
{
BDRVQcow2State *s = bs->opaque;
unsigned int l2_index;
- uint64_t l1_index, l2_offset, *l2_table;
- int l1_bits, c;
+ uint64_t l1_index, l2_offset, *l2_slice;
+ int c;
unsigned int offset_in_cluster;
uint64_t bytes_available, bytes_needed, nb_clusters;
QCow2ClusterType type;
@@ -525,12 +539,12 @@ int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
offset_in_cluster = offset_into_cluster(s, offset);
bytes_needed = (uint64_t) *bytes + offset_in_cluster;
- l1_bits = s->l2_bits + s->cluster_bits;
-
/* compute how many bytes there are between the start of the cluster
- * containing offset and the end of the l1 entry */
- bytes_available = (1ULL << l1_bits) - (offset & ((1ULL << l1_bits) - 1))
- + offset_in_cluster;
+ * containing offset and the end of the l2 slice that contains
+ * the entry pointing to it */
+ bytes_available =
+ ((uint64_t) (s->l2_slice_size - offset_to_l2_slice_index(s, offset)))
+ << s->cluster_bits;
if (bytes_needed > bytes_available) {
bytes_needed = bytes_available;
@@ -540,7 +554,7 @@ int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
/* seek to the l2 offset in the l1 table */
- l1_index = offset >> l1_bits;
+ l1_index = offset_to_l1_index(s, offset);
if (l1_index >= s->l1_size) {
type = QCOW2_CLUSTER_UNALLOCATED;
goto out;
@@ -559,17 +573,17 @@ int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
return -EIO;
}
- /* load the l2 table in memory */
+ /* load the l2 slice in memory */
- ret = l2_load(bs, l2_offset, &l2_table);
+ ret = l2_load(bs, offset, l2_offset, &l2_slice);
if (ret < 0) {
return ret;
}
/* find the cluster offset for the given disk offset */
- l2_index = offset_to_l2_index(s, offset);
- *cluster_offset = be64_to_cpu(l2_table[l2_index]);
+ l2_index = offset_to_l2_slice_index(s, offset);
+ *cluster_offset = be64_to_cpu(l2_slice[l2_index]);
nb_clusters = size_to_clusters(s, bytes_needed);
/* bytes_needed <= *bytes + offset_in_cluster, both of which are unsigned
@@ -596,14 +610,14 @@ int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
case QCOW2_CLUSTER_UNALLOCATED:
/* how many empty clusters ? */
c = count_contiguous_clusters_unallocated(nb_clusters,
- &l2_table[l2_index], type);
+ &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,
- &l2_table[l2_index], QCOW_OFLAG_ZERO);
+ &l2_slice[l2_index], QCOW_OFLAG_ZERO);
*cluster_offset &= L2E_OFFSET_MASK;
if (offset_into_cluster(s, *cluster_offset)) {
qcow2_signal_corruption(bs, true, -1, -1,
@@ -619,7 +633,7 @@ int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
abort();
}
- qcow2_cache_put(bs, s->l2_table_cache, (void**) &l2_table);
+ qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice);
bytes_available = (int64_t)c * s->cluster_size;
@@ -637,7 +651,7 @@ out:
return type;
fail:
- qcow2_cache_put(bs, s->l2_table_cache, (void **)&l2_table);
+ qcow2_cache_put(s->l2_table_cache, (void **)&l2_slice);
return ret;
}
@@ -645,26 +659,25 @@ fail:
* get_cluster_table
*
* for a given disk offset, load (and allocate if needed)
- * the l2 table.
+ * the appropriate slice of its l2 table.
*
- * the l2 table offset in the qcow2 file and the cluster index
- * in the l2 table are given to the caller.
+ * the cluster index in the l2 slice is given to the caller.
*
* Returns 0 on success, -errno in failure case
*/
static int get_cluster_table(BlockDriverState *bs, uint64_t offset,
- uint64_t **new_l2_table,
+ uint64_t **new_l2_slice,
int *new_l2_index)
{
BDRVQcow2State *s = bs->opaque;
unsigned int l2_index;
uint64_t l1_index, l2_offset;
- uint64_t *l2_table = NULL;
+ uint64_t *l2_slice = NULL;
int ret;
/* seek to the l2 offset in the l1 table */
- l1_index = offset >> (s->l2_bits + s->cluster_bits);
+ l1_index = offset_to_l1_index(s, offset);
if (l1_index >= s->l1_size) {
ret = qcow2_grow_l1_table(bs, l1_index + 1, false);
if (ret < 0) {
@@ -681,17 +694,9 @@ static int get_cluster_table(BlockDriverState *bs, uint64_t offset,
return -EIO;
}
- /* seek the l2 table of the given l2 offset */
-
- if (s->l1_table[l1_index] & QCOW_OFLAG_COPIED) {
- /* load the l2 table in memory */
- ret = l2_load(bs, l2_offset, &l2_table);
- if (ret < 0) {
- return ret;
- }
- } else {
+ if (!(s->l1_table[l1_index] & QCOW_OFLAG_COPIED)) {
/* First allocate a new L2 table (and do COW if needed) */
- ret = l2_allocate(bs, l1_index, &l2_table);
+ ret = l2_allocate(bs, l1_index);
if (ret < 0) {
return ret;
}
@@ -701,13 +706,23 @@ static int get_cluster_table(BlockDriverState *bs, uint64_t offset,
qcow2_free_clusters(bs, l2_offset, s->l2_size * sizeof(uint64_t),
QCOW2_DISCARD_OTHER);
}
+
+ /* Get the offset of the newly-allocated l2 table */
+ l2_offset = s->l1_table[l1_index] & L1E_OFFSET_MASK;
+ assert(offset_into_cluster(s, l2_offset) == 0);
+ }
+
+ /* load the l2 slice in memory */
+ ret = l2_load(bs, offset, l2_offset, &l2_slice);
+ if (ret < 0) {
+ return ret;
}
/* find the cluster offset for the given disk offset */
- l2_index = offset_to_l2_index(s, offset);
+ l2_index = offset_to_l2_slice_index(s, offset);
- *new_l2_table = l2_table;
+ *new_l2_slice = l2_slice;
*new_l2_index = l2_index;
return 0;
@@ -732,26 +747,26 @@ uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
{
BDRVQcow2State *s = bs->opaque;
int l2_index, ret;
- uint64_t *l2_table;
+ uint64_t *l2_slice;
int64_t cluster_offset;
int nb_csectors;
- ret = get_cluster_table(bs, offset, &l2_table, &l2_index);
+ ret = get_cluster_table(bs, offset, &l2_slice, &l2_index);
if (ret < 0) {
return 0;
}
/* Compression can't overwrite anything. Fail if the cluster was already
* allocated. */
- cluster_offset = be64_to_cpu(l2_table[l2_index]);
+ cluster_offset = be64_to_cpu(l2_slice[l2_index]);
if (cluster_offset & L2E_OFFSET_MASK) {
- qcow2_cache_put(bs, s->l2_table_cache, (void**) &l2_table);
+ qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice);
return 0;
}
cluster_offset = qcow2_alloc_bytes(bs, compressed_size);
if (cluster_offset < 0) {
- qcow2_cache_put(bs, s->l2_table_cache, (void**) &l2_table);
+ qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice);
return 0;
}
@@ -766,9 +781,9 @@ uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
/* compressed clusters never have the copied flag */
BLKDBG_EVENT(bs->file, BLKDBG_L2_UPDATE_COMPRESSED);
- qcow2_cache_entry_mark_dirty(bs, s->l2_table_cache, l2_table);
- l2_table[l2_index] = cpu_to_be64(cluster_offset);
- qcow2_cache_put(bs, s->l2_table_cache, (void **) &l2_table);
+ qcow2_cache_entry_mark_dirty(s->l2_table_cache, l2_slice);
+ l2_slice[l2_index] = cpu_to_be64(cluster_offset);
+ qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice);
return cluster_offset;
}
@@ -907,7 +922,7 @@ int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m)
{
BDRVQcow2State *s = bs->opaque;
int i, j = 0, l2_index, ret;
- uint64_t *old_cluster, *l2_table;
+ uint64_t *old_cluster, *l2_slice;
uint64_t cluster_offset = m->alloc_offset;
trace_qcow2_cluster_link_l2(qemu_coroutine_self(), m->nb_clusters);
@@ -934,13 +949,13 @@ int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m)
s->refcount_block_cache);
}
- ret = get_cluster_table(bs, m->offset, &l2_table, &l2_index);
+ ret = get_cluster_table(bs, m->offset, &l2_slice, &l2_index);
if (ret < 0) {
goto err;
}
- qcow2_cache_entry_mark_dirty(bs, s->l2_table_cache, l2_table);
+ qcow2_cache_entry_mark_dirty(s->l2_table_cache, l2_slice);
- assert(l2_index + m->nb_clusters <= s->l2_size);
+ assert(l2_index + m->nb_clusters <= s->l2_slice_size);
for (i = 0; i < m->nb_clusters; i++) {
/* if two concurrent writes happen to the same unallocated cluster
* each write allocates separate cluster and writes data concurrently.
@@ -948,16 +963,16 @@ int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m)
* cluster the second one has to do RMW (which is done above by
* perform_cow()), update l2 table with its cluster pointer and free
* old cluster. This is what this loop does */
- if (l2_table[l2_index + i] != 0) {
- old_cluster[j++] = l2_table[l2_index + i];
+ if (l2_slice[l2_index + i] != 0) {
+ old_cluster[j++] = l2_slice[l2_index + i];
}
- l2_table[l2_index + i] = cpu_to_be64((cluster_offset +
+ l2_slice[l2_index + i] = cpu_to_be64((cluster_offset +
(i << s->cluster_bits)) | QCOW_OFLAG_COPIED);
}
- qcow2_cache_put(bs, s->l2_table_cache, (void **) &l2_table);
+ qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice);
/*
* If this was a COW, we need to decrease the refcount of the old cluster.
@@ -984,12 +999,12 @@ err:
* which must copy from the backing file)
*/
static int count_cow_clusters(BDRVQcow2State *s, int nb_clusters,
- uint64_t *l2_table, int l2_index)
+ uint64_t *l2_slice, int l2_index)
{
int i;
for (i = 0; i < nb_clusters; i++) {
- uint64_t l2_entry = be64_to_cpu(l2_table[l2_index + i]);
+ uint64_t l2_entry = be64_to_cpu(l2_slice[l2_index + i]);
QCow2ClusterType cluster_type = qcow2_get_cluster_type(l2_entry);
switch(cluster_type) {
@@ -1104,7 +1119,7 @@ static int handle_copied(BlockDriverState *bs, uint64_t guest_offset,
BDRVQcow2State *s = bs->opaque;
int l2_index;
uint64_t cluster_offset;
- uint64_t *l2_table;
+ uint64_t *l2_slice;
uint64_t nb_clusters;
unsigned int keep_clusters;
int ret;
@@ -1116,23 +1131,23 @@ static int handle_copied(BlockDriverState *bs, uint64_t guest_offset,
== offset_into_cluster(s, *host_offset));
/*
- * Calculate the number of clusters to look for. We stop at L2 table
+ * Calculate the number of clusters to look for. We stop at L2 slice
* boundaries to keep things simple.
*/
nb_clusters =
size_to_clusters(s, offset_into_cluster(s, guest_offset) + *bytes);
- l2_index = offset_to_l2_index(s, guest_offset);
- nb_clusters = MIN(nb_clusters, s->l2_size - l2_index);
+ l2_index = offset_to_l2_slice_index(s, guest_offset);
+ nb_clusters = MIN(nb_clusters, s->l2_slice_size - l2_index);
assert(nb_clusters <= INT_MAX);
/* Find L2 entry for the first involved cluster */
- ret = get_cluster_table(bs, guest_offset, &l2_table, &l2_index);
+ ret = get_cluster_table(bs, guest_offset, &l2_slice, &l2_index);
if (ret < 0) {
return ret;
}
- cluster_offset = be64_to_cpu(l2_table[l2_index]);
+ 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
@@ -1160,7 +1175,7 @@ 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,
- &l2_table[l2_index],
+ &l2_slice[l2_index],
QCOW_OFLAG_COPIED | QCOW_OFLAG_ZERO);
assert(keep_clusters <= nb_clusters);
@@ -1175,7 +1190,7 @@ static int handle_copied(BlockDriverState *bs, uint64_t guest_offset,
/* Cleanup */
out:
- qcow2_cache_put(bs, s->l2_table_cache, (void **) &l2_table);
+ qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice);
/* Only return a host offset if we actually made progress. Otherwise we
* would make requirements for handle_alloc() that it can't fulfill */
@@ -1259,7 +1274,7 @@ static int handle_alloc(BlockDriverState *bs, uint64_t guest_offset,
{
BDRVQcow2State *s = bs->opaque;
int l2_index;
- uint64_t *l2_table;
+ uint64_t *l2_slice;
uint64_t entry;
uint64_t nb_clusters;
int ret;
@@ -1272,29 +1287,29 @@ static int handle_alloc(BlockDriverState *bs, uint64_t guest_offset,
assert(*bytes > 0);
/*
- * Calculate the number of clusters to look for. We stop at L2 table
+ * Calculate the number of clusters to look for. We stop at L2 slice
* boundaries to keep things simple.
*/
nb_clusters =
size_to_clusters(s, offset_into_cluster(s, guest_offset) + *bytes);
- l2_index = offset_to_l2_index(s, guest_offset);
- nb_clusters = MIN(nb_clusters, s->l2_size - l2_index);
+ l2_index = offset_to_l2_slice_index(s, guest_offset);
+ nb_clusters = MIN(nb_clusters, s->l2_slice_size - l2_index);
assert(nb_clusters <= INT_MAX);
/* Find L2 entry for the first involved cluster */
- ret = get_cluster_table(bs, guest_offset, &l2_table, &l2_index);
+ ret = get_cluster_table(bs, guest_offset, &l2_slice, &l2_index);
if (ret < 0) {
return ret;
}
- entry = be64_to_cpu(l2_table[l2_index]);
+ entry = be64_to_cpu(l2_slice[l2_index]);
/* For the moment, overwrite compressed clusters one by one */
if (entry & QCOW_OFLAG_COMPRESSED) {
nb_clusters = 1;
} else {
- nb_clusters = count_cow_clusters(s, nb_clusters, l2_table, l2_index);
+ nb_clusters = count_cow_clusters(s, nb_clusters, l2_slice, l2_index);
}
/* This function is only called when there were no non-COW clusters, so if
@@ -1323,7 +1338,7 @@ static int handle_alloc(BlockDriverState *bs, uint64_t guest_offset,
* nb_clusters already to a range of COW clusters */
preallocated_nb_clusters =
count_contiguous_clusters(nb_clusters, s->cluster_size,
- &l2_table[l2_index], QCOW_OFLAG_COPIED);
+ &l2_slice[l2_index], QCOW_OFLAG_COPIED);
assert(preallocated_nb_clusters > 0);
nb_clusters = preallocated_nb_clusters;
@@ -1334,7 +1349,7 @@ static int handle_alloc(BlockDriverState *bs, uint64_t guest_offset,
keep_old_clusters = true;
}
- qcow2_cache_put(bs, s->l2_table_cache, (void **) &l2_table);
+ qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice);
if (!alloc_cluster_offset) {
/* Allocate, if necessary at a given offset in the image file */
@@ -1616,32 +1631,32 @@ int qcow2_decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset)
/*
* This discards as many clusters of nb_clusters as possible at once (i.e.
- * all clusters in the same L2 table) and returns the number of discarded
+ * all clusters in the same L2 slice) and returns the number of discarded
* clusters.
*/
-static int discard_single_l2(BlockDriverState *bs, uint64_t offset,
- uint64_t nb_clusters, enum qcow2_discard_type type,
- bool full_discard)
+static int discard_in_l2_slice(BlockDriverState *bs, uint64_t offset,
+ uint64_t nb_clusters,
+ enum qcow2_discard_type type, bool full_discard)
{
BDRVQcow2State *s = bs->opaque;
- uint64_t *l2_table;
+ uint64_t *l2_slice;
int l2_index;
int ret;
int i;
- ret = get_cluster_table(bs, offset, &l2_table, &l2_index);
+ ret = get_cluster_table(bs, offset, &l2_slice, &l2_index);
if (ret < 0) {
return ret;
}
- /* Limit nb_clusters to one L2 table */
- nb_clusters = MIN(nb_clusters, s->l2_size - l2_index);
+ /* Limit nb_clusters to one L2 slice */
+ nb_clusters = MIN(nb_clusters, s->l2_slice_size - l2_index);
assert(nb_clusters <= INT_MAX);
for (i = 0; i < nb_clusters; i++) {
uint64_t old_l2_entry;
- old_l2_entry = be64_to_cpu(l2_table[l2_index + i]);
+ old_l2_entry = be64_to_cpu(l2_slice[l2_index + i]);
/*
* If full_discard is false, make sure that a discarded area reads back
@@ -1679,18 +1694,18 @@ static int discard_single_l2(BlockDriverState *bs, uint64_t offset,
}
/* First remove L2 entries */
- qcow2_cache_entry_mark_dirty(bs, s->l2_table_cache, l2_table);
+ qcow2_cache_entry_mark_dirty(s->l2_table_cache, l2_slice);
if (!full_discard && s->qcow_version >= 3) {
- l2_table[l2_index + i] = cpu_to_be64(QCOW_OFLAG_ZERO);
+ l2_slice[l2_index + i] = cpu_to_be64(QCOW_OFLAG_ZERO);
} else {
- l2_table[l2_index + i] = cpu_to_be64(0);
+ l2_slice[l2_index + i] = cpu_to_be64(0);
}
/* Then decrease the refcount */
qcow2_free_any_clusters(bs, old_l2_entry, 1, type);
}
- qcow2_cache_put(bs, s->l2_table_cache, (void **) &l2_table);
+ qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice);
return nb_clusters;
}
@@ -1714,10 +1729,10 @@ int qcow2_cluster_discard(BlockDriverState *bs, uint64_t offset,
s->cache_discards = true;
- /* Each L2 table is handled by its own loop iteration */
+ /* Each L2 slice is handled by its own loop iteration */
while (nb_clusters > 0) {
- cleared = discard_single_l2(bs, offset, nb_clusters, type,
- full_discard);
+ cleared = discard_in_l2_slice(bs, offset, nb_clusters, type,
+ full_discard);
if (cleared < 0) {
ret = cleared;
goto fail;
@@ -1737,33 +1752,33 @@ fail:
/*
* This zeroes as many clusters of nb_clusters as possible at once (i.e.
- * all clusters in the same L2 table) and returns the number of zeroed
+ * all clusters in the same L2 slice) and returns the number of zeroed
* clusters.
*/
-static int zero_single_l2(BlockDriverState *bs, uint64_t offset,
- uint64_t nb_clusters, int flags)
+static int zero_in_l2_slice(BlockDriverState *bs, uint64_t offset,
+ uint64_t nb_clusters, int flags)
{
BDRVQcow2State *s = bs->opaque;
- uint64_t *l2_table;
+ uint64_t *l2_slice;
int l2_index;
int ret;
int i;
bool unmap = !!(flags & BDRV_REQ_MAY_UNMAP);
- ret = get_cluster_table(bs, offset, &l2_table, &l2_index);
+ ret = get_cluster_table(bs, offset, &l2_slice, &l2_index);
if (ret < 0) {
return ret;
}
- /* Limit nb_clusters to one L2 table */
- nb_clusters = MIN(nb_clusters, s->l2_size - l2_index);
+ /* Limit nb_clusters to one L2 slice */
+ nb_clusters = MIN(nb_clusters, s->l2_slice_size - l2_index);
assert(nb_clusters <= INT_MAX);
for (i = 0; i < nb_clusters; i++) {
uint64_t old_offset;
QCow2ClusterType cluster_type;
- old_offset = be64_to_cpu(l2_table[l2_index + i]);
+ old_offset = be64_to_cpu(l2_slice[l2_index + i]);
/*
* Minimize L2 changes if the cluster already reads back as
@@ -1775,16 +1790,16 @@ static int zero_single_l2(BlockDriverState *bs, uint64_t offset,
continue;
}
- qcow2_cache_entry_mark_dirty(bs, s->l2_table_cache, l2_table);
+ qcow2_cache_entry_mark_dirty(s->l2_table_cache, l2_slice);
if (cluster_type == QCOW2_CLUSTER_COMPRESSED || unmap) {
- l2_table[l2_index + i] = cpu_to_be64(QCOW_OFLAG_ZERO);
+ l2_slice[l2_index + i] = cpu_to_be64(QCOW_OFLAG_ZERO);
qcow2_free_any_clusters(bs, old_offset, 1, QCOW2_DISCARD_REQUEST);
} else {
- l2_table[l2_index + i] |= cpu_to_be64(QCOW_OFLAG_ZERO);
+ l2_slice[l2_index + i] |= cpu_to_be64(QCOW_OFLAG_ZERO);
}
}
- qcow2_cache_put(bs, s->l2_table_cache, (void **) &l2_table);
+ qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice);
return nb_clusters;
}
@@ -1808,13 +1823,13 @@ int qcow2_cluster_zeroize(BlockDriverState *bs, uint64_t offset,
return -ENOTSUP;
}
- /* Each L2 table is handled by its own loop iteration */
+ /* Each L2 slice is handled by its own loop iteration */
nb_clusters = size_to_clusters(s, bytes);
s->cache_discards = true;
while (nb_clusters > 0) {
- cleared = zero_single_l2(bs, offset, nb_clusters, flags);
+ cleared = zero_in_l2_slice(bs, offset, nb_clusters, flags);
if (cleared < 0) {
ret = cleared;
goto fail;
@@ -1848,22 +1863,25 @@ static int expand_zero_clusters_in_l1(BlockDriverState *bs, uint64_t *l1_table,
{
BDRVQcow2State *s = bs->opaque;
bool is_active_l1 = (l1_table == s->l1_table);
- uint64_t *l2_table = NULL;
+ uint64_t *l2_slice = NULL;
+ unsigned slice, slice_size2, n_slices;
int ret;
int i, j;
+ slice_size2 = s->l2_slice_size * sizeof(uint64_t);
+ n_slices = s->cluster_size / slice_size2;
+
if (!is_active_l1) {
/* inactive L2 tables require a buffer to be stored in when loading
* them from disk */
- l2_table = qemu_try_blockalign(bs->file->bs, s->cluster_size);
- if (l2_table == NULL) {
+ l2_slice = qemu_try_blockalign(bs->file->bs, slice_size2);
+ if (l2_slice == NULL) {
return -ENOMEM;
}
}
for (i = 0; i < l1_size; i++) {
uint64_t l2_offset = l1_table[i] & L1E_OFFSET_MASK;
- bool l2_dirty = false;
uint64_t l2_refcount;
if (!l2_offset) {
@@ -1883,124 +1901,131 @@ static int expand_zero_clusters_in_l1(BlockDriverState *bs, uint64_t *l1_table,
goto fail;
}
- if (is_active_l1) {
- /* get active L2 tables from cache */
- ret = qcow2_cache_get(bs, s->l2_table_cache, l2_offset,
- (void **)&l2_table);
- } else {
- /* load inactive L2 tables from disk */
- ret = bdrv_read(bs->file, l2_offset / BDRV_SECTOR_SIZE,
- (void *)l2_table, s->cluster_sectors);
- }
- if (ret < 0) {
- goto fail;
- }
-
ret = qcow2_get_refcount(bs, l2_offset >> s->cluster_bits,
&l2_refcount);
if (ret < 0) {
goto fail;
}
- for (j = 0; j < s->l2_size; j++) {
- uint64_t l2_entry = be64_to_cpu(l2_table[j]);
- int64_t offset = l2_entry & L2E_OFFSET_MASK;
- QCow2ClusterType cluster_type = qcow2_get_cluster_type(l2_entry);
-
- if (cluster_type != QCOW2_CLUSTER_ZERO_PLAIN &&
- cluster_type != QCOW2_CLUSTER_ZERO_ALLOC) {
- continue;
+ for (slice = 0; slice < n_slices; slice++) {
+ uint64_t slice_offset = l2_offset + slice * slice_size2;
+ bool l2_dirty = false;
+ if (is_active_l1) {
+ /* get active L2 tables from cache */
+ ret = qcow2_cache_get(bs, s->l2_table_cache, slice_offset,
+ (void **)&l2_slice);
+ } else {
+ /* load inactive L2 tables from disk */
+ ret = bdrv_pread(bs->file, slice_offset, l2_slice, slice_size2);
+ }
+ if (ret < 0) {
+ goto fail;
}
- if (cluster_type == QCOW2_CLUSTER_ZERO_PLAIN) {
- if (!bs->backing) {
- /* not backed; therefore we can simply deallocate the
- * cluster */
- l2_table[j] = 0;
- l2_dirty = true;
+ for (j = 0; j < s->l2_slice_size; j++) {
+ 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);
+
+ if (cluster_type != QCOW2_CLUSTER_ZERO_PLAIN &&
+ cluster_type != QCOW2_CLUSTER_ZERO_ALLOC) {
continue;
}
- offset = qcow2_alloc_clusters(bs, s->cluster_size);
- if (offset < 0) {
- ret = offset;
- goto fail;
- }
+ if (cluster_type == QCOW2_CLUSTER_ZERO_PLAIN) {
+ if (!bs->backing) {
+ /* not backed; therefore we can simply deallocate the
+ * cluster */
+ l2_slice[j] = 0;
+ l2_dirty = true;
+ continue;
+ }
+
+ offset = qcow2_alloc_clusters(bs, s->cluster_size);
+ if (offset < 0) {
+ ret = offset;
+ goto fail;
+ }
- if (l2_refcount > 1) {
- /* For shared L2 tables, set the refcount accordingly (it is
- * already 1 and needs to be l2_refcount) */
- ret = qcow2_update_cluster_refcount(bs,
- offset >> s->cluster_bits,
+ if (l2_refcount > 1) {
+ /* For shared L2 tables, set the refcount accordingly
+ * (it is already 1 and needs to be l2_refcount) */
+ ret = qcow2_update_cluster_refcount(
+ bs, offset >> s->cluster_bits,
refcount_diff(1, l2_refcount), false,
QCOW2_DISCARD_OTHER);
- if (ret < 0) {
- qcow2_free_clusters(bs, offset, s->cluster_size,
- QCOW2_DISCARD_OTHER);
- goto fail;
+ if (ret < 0) {
+ qcow2_free_clusters(bs, offset, s->cluster_size,
+ QCOW2_DISCARD_OTHER);
+ goto fail;
+ }
}
}
- }
- if (offset_into_cluster(s, offset)) {
- qcow2_signal_corruption(bs, true, -1, -1,
- "Cluster allocation offset "
- "%#" PRIx64 " unaligned (L2 offset: %#"
- PRIx64 ", L2 index: %#x)", offset,
- l2_offset, j);
- if (cluster_type == QCOW2_CLUSTER_ZERO_PLAIN) {
- qcow2_free_clusters(bs, offset, s->cluster_size,
- QCOW2_DISCARD_ALWAYS);
+ if (offset_into_cluster(s, offset)) {
+ int l2_index = slice * s->l2_slice_size + j;
+ qcow2_signal_corruption(
+ bs, true, -1, -1,
+ "Cluster allocation offset "
+ "%#" PRIx64 " unaligned (L2 offset: %#"
+ PRIx64 ", L2 index: %#x)", offset,
+ l2_offset, l2_index);
+ if (cluster_type == QCOW2_CLUSTER_ZERO_PLAIN) {
+ qcow2_free_clusters(bs, offset, s->cluster_size,
+ QCOW2_DISCARD_ALWAYS);
+ }
+ ret = -EIO;
+ goto fail;
}
- ret = -EIO;
- goto fail;
- }
- ret = qcow2_pre_write_overlap_check(bs, 0, offset, s->cluster_size);
- if (ret < 0) {
- if (cluster_type == QCOW2_CLUSTER_ZERO_PLAIN) {
- qcow2_free_clusters(bs, offset, s->cluster_size,
- QCOW2_DISCARD_ALWAYS);
+ ret = qcow2_pre_write_overlap_check(bs, 0, offset,
+ s->cluster_size);
+ if (ret < 0) {
+ if (cluster_type == QCOW2_CLUSTER_ZERO_PLAIN) {
+ qcow2_free_clusters(bs, offset, s->cluster_size,
+ QCOW2_DISCARD_ALWAYS);
+ }
+ goto fail;
}
- goto fail;
- }
- ret = bdrv_pwrite_zeroes(bs->file, offset, s->cluster_size, 0);
- if (ret < 0) {
- if (cluster_type == QCOW2_CLUSTER_ZERO_PLAIN) {
- qcow2_free_clusters(bs, offset, s->cluster_size,
- QCOW2_DISCARD_ALWAYS);
+ ret = bdrv_pwrite_zeroes(bs->file, offset, s->cluster_size, 0);
+ if (ret < 0) {
+ if (cluster_type == QCOW2_CLUSTER_ZERO_PLAIN) {
+ qcow2_free_clusters(bs, offset, s->cluster_size,
+ QCOW2_DISCARD_ALWAYS);
+ }
+ goto fail;
}
- goto fail;
- }
- if (l2_refcount == 1) {
- l2_table[j] = cpu_to_be64(offset | QCOW_OFLAG_COPIED);
- } else {
- l2_table[j] = cpu_to_be64(offset);
+ if (l2_refcount == 1) {
+ l2_slice[j] = cpu_to_be64(offset | QCOW_OFLAG_COPIED);
+ } else {
+ l2_slice[j] = cpu_to_be64(offset);
+ }
+ l2_dirty = true;
}
- l2_dirty = true;
- }
- if (is_active_l1) {
- if (l2_dirty) {
- qcow2_cache_entry_mark_dirty(bs, s->l2_table_cache, l2_table);
- qcow2_cache_depends_on_flush(s->l2_table_cache);
- }
- qcow2_cache_put(bs, s->l2_table_cache, (void **) &l2_table);
- } else {
- if (l2_dirty) {
- ret = qcow2_pre_write_overlap_check(bs,
- QCOW2_OL_INACTIVE_L2 | QCOW2_OL_ACTIVE_L2, l2_offset,
- s->cluster_size);
- if (ret < 0) {
- goto fail;
+ if (is_active_l1) {
+ if (l2_dirty) {
+ qcow2_cache_entry_mark_dirty(s->l2_table_cache, l2_slice);
+ qcow2_cache_depends_on_flush(s->l2_table_cache);
}
+ qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice);
+ } else {
+ if (l2_dirty) {
+ ret = qcow2_pre_write_overlap_check(
+ bs, QCOW2_OL_INACTIVE_L2 | QCOW2_OL_ACTIVE_L2,
+ slice_offset, slice_size2);
+ if (ret < 0) {
+ goto fail;
+ }
- ret = bdrv_write(bs->file, l2_offset / BDRV_SECTOR_SIZE,
- (void *)l2_table, s->cluster_sectors);
- if (ret < 0) {
- goto fail;
+ ret = bdrv_pwrite(bs->file, slice_offset,
+ l2_slice, slice_size2);
+ if (ret < 0) {
+ goto fail;
+ }
}
}
}
@@ -2014,11 +2039,11 @@ static int expand_zero_clusters_in_l1(BlockDriverState *bs, uint64_t *l1_table,
ret = 0;
fail:
- if (l2_table) {
+ if (l2_slice) {
if (!is_active_l1) {
- qemu_vfree(l2_table);
+ qemu_vfree(l2_slice);
} else {
- qcow2_cache_put(bs, s->l2_table_cache, (void **) &l2_table);
+ qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice);
}
}
return ret;
@@ -2070,7 +2095,15 @@ int qcow2_expand_zero_clusters(BlockDriverState *bs,
int l1_sectors = DIV_ROUND_UP(s->snapshots[i].l1_size *
sizeof(uint64_t), BDRV_SECTOR_SIZE);
- l1_table = g_realloc(l1_table, l1_sectors * BDRV_SECTOR_SIZE);
+ uint64_t *new_l1_table =
+ g_try_realloc(l1_table, l1_sectors * BDRV_SECTOR_SIZE);
+
+ if (!new_l1_table) {
+ ret = -ENOMEM;
+ goto fail;
+ }
+
+ l1_table = new_l1_table;
ret = bdrv_read(bs->file,
s->snapshots[i].l1_table_offset / BDRV_SECTOR_SIZE,
generated by cgit v1.2.1 (git 2.18.0) at 2024-06-08 20:35:01 +0000