#include "block/qcow2.h"
#include "qemu/range.h"
#include "qemu/bswap.h"
+#include "qemu/cutils.h"
static int64_t alloc_clusters_noref(BlockDriverState *bs, uint64_t size);
static int QEMU_WARN_UNUSED_RESULT update_refcount(BlockDriverState *bs,
/*********************************************************/
/* refcount handling */
+static void update_max_refcount_table_index(BDRVQcow2State *s)
+{
+ unsigned i = s->refcount_table_size - 1;
+ while (i > 0 && (s->refcount_table[i] & REFT_OFFSET_MASK) == 0) {
+ i--;
+ }
+ /* Set s->max_refcount_table_index to the index of the last used entry */
+ s->max_refcount_table_index = i;
+}
+
int qcow2_refcount_init(BlockDriverState *bs)
{
BDRVQcow2State *s = bs->opaque;
}
for(i = 0; i < s->refcount_table_size; i++)
be64_to_cpus(&s->refcount_table[i]);
+ update_max_refcount_table_index(s);
}
return 0;
fail:
block_index = cluster_index & (s->refcount_block_size - 1);
*refcount = s->get_refcount(refcount_block, block_index);
- qcow2_cache_put(bs, s->refcount_block_cache, &refcount_block);
+ qcow2_cache_put(s->refcount_block_cache, &refcount_block);
return 0;
}
-/*
- * Rounds the refcount table size up to avoid growing the table for each single
- * refcount block that is allocated.
- */
-static unsigned int next_refcount_table_size(BDRVQcow2State *s,
- unsigned int min_size)
-{
- unsigned int min_clusters = (min_size >> (s->cluster_bits - 3)) + 1;
- unsigned int refcount_table_clusters =
- MAX(1, s->refcount_table_size >> (s->cluster_bits - 3));
-
- while (min_clusters > refcount_table_clusters) {
- refcount_table_clusters = (refcount_table_clusters * 3 + 1) / 2;
- }
-
- return refcount_table_clusters << (s->cluster_bits - 3);
-}
-
-
/* Checks if two offsets are described by the same refcount block */
static int in_same_refcount_block(BDRVQcow2State *s, uint64_t offset_a,
uint64_t offset_b)
{
BDRVQcow2State *s = bs->opaque;
unsigned int refcount_table_index;
- int ret;
+ int64_t ret;
BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC);
return new_block;
}
+ /* If we're allocating the block at offset 0 then something is wrong */
+ if (new_block == 0) {
+ qcow2_signal_corruption(bs, true, -1, -1, "Preventing invalid "
+ "allocation of refcount block at offset 0");
+ return -EIO;
+ }
+
#ifdef DEBUG_ALLOC2
fprintf(stderr, "qcow2: Allocate refcount block %d for %" PRIx64
" at %" PRIx64 "\n",
ret = qcow2_cache_get_empty(bs, s->refcount_block_cache, new_block,
refcount_block);
if (ret < 0) {
- goto fail_block;
+ goto fail;
}
memset(*refcount_block, 0, s->cluster_size);
ret = update_refcount(bs, new_block, s->cluster_size, 1, false,
QCOW2_DISCARD_NEVER);
if (ret < 0) {
- goto fail_block;
+ goto fail;
}
ret = qcow2_cache_flush(bs, s->refcount_block_cache);
if (ret < 0) {
- goto fail_block;
+ goto fail;
}
/* Initialize the new refcount block only after updating its refcount,
ret = qcow2_cache_get_empty(bs, s->refcount_block_cache, new_block,
refcount_block);
if (ret < 0) {
- goto fail_block;
+ goto fail;
}
memset(*refcount_block, 0, s->cluster_size);
/* Now the new refcount block needs to be written to disk */
BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_WRITE);
- qcow2_cache_entry_mark_dirty(bs, s->refcount_block_cache, *refcount_block);
+ qcow2_cache_entry_mark_dirty(s->refcount_block_cache, *refcount_block);
ret = qcow2_cache_flush(bs, s->refcount_block_cache);
if (ret < 0) {
- goto fail_block;
+ goto fail;
}
/* If the refcount table is big enough, just hook the block up there */
s->refcount_table_offset + refcount_table_index * sizeof(uint64_t),
&data64, sizeof(data64));
if (ret < 0) {
- goto fail_block;
+ goto fail;
}
s->refcount_table[refcount_table_index] = new_block;
+ /* If there's a hole in s->refcount_table then it can happen
+ * that refcount_table_index < s->max_refcount_table_index */
+ s->max_refcount_table_index =
+ MAX(s->max_refcount_table_index, refcount_table_index);
/* The new refcount block may be where the caller intended to put its
* data, so let it restart the search. */
return -EAGAIN;
}
- qcow2_cache_put(bs, s->refcount_block_cache, refcount_block);
+ qcow2_cache_put(s->refcount_block_cache, refcount_block);
/*
* If we come here, we need to grow the refcount table. Again, a new
(new_block >> s->cluster_bits) + 1),
s->refcount_block_size);
- if (blocks_used > QCOW_MAX_REFTABLE_SIZE / sizeof(uint64_t)) {
- return -EFBIG;
+ /* Create the new refcount table and blocks */
+ uint64_t meta_offset = (blocks_used * s->refcount_block_size) *
+ s->cluster_size;
+
+ ret = qcow2_refcount_area(bs, meta_offset, 0, false,
+ refcount_table_index, new_block);
+ if (ret < 0) {
+ return ret;
}
- /* And now we need at least one block more for the new metadata */
- uint64_t table_size = next_refcount_table_size(s, blocks_used + 1);
- uint64_t last_table_size;
- uint64_t blocks_clusters;
- do {
- uint64_t table_clusters =
- size_to_clusters(s, table_size * sizeof(uint64_t));
- blocks_clusters = 1 +
- DIV_ROUND_UP(table_clusters, s->refcount_block_size);
- uint64_t meta_clusters = table_clusters + blocks_clusters;
+ ret = load_refcount_block(bs, new_block, refcount_block);
+ if (ret < 0) {
+ return ret;
+ }
- last_table_size = table_size;
- table_size = next_refcount_table_size(s, blocks_used +
- DIV_ROUND_UP(meta_clusters, s->refcount_block_size));
+ /* If we were trying to do the initial refcount update for some cluster
+ * allocation, we might have used the same clusters to store newly
+ * allocated metadata. Make the caller search some new space. */
+ return -EAGAIN;
- } while (last_table_size != table_size);
+fail:
+ if (*refcount_block != NULL) {
+ qcow2_cache_put(s->refcount_block_cache, refcount_block);
+ }
+ return ret;
+}
-#ifdef DEBUG_ALLOC2
- fprintf(stderr, "qcow2: Grow refcount table %" PRId32 " => %" PRId64 "\n",
- s->refcount_table_size, table_size);
-#endif
+/*
+ * Starting at @start_offset, this function creates new self-covering refcount
+ * structures: A new refcount table and refcount blocks which cover all of
+ * themselves, and a number of @additional_clusters beyond their end.
+ * @start_offset must be at the end of the image file, that is, there must be
+ * only empty space beyond it.
+ * If @exact_size is false, the refcount table will have 50 % more entries than
+ * necessary so it will not need to grow again soon.
+ * If @new_refblock_offset is not zero, it contains the offset of a refcount
+ * block that should be entered into the new refcount table at index
+ * @new_refblock_index.
+ *
+ * Returns: The offset after the new refcount structures (i.e. where the
+ * @additional_clusters may be placed) on success, -errno on error.
+ */
+int64_t qcow2_refcount_area(BlockDriverState *bs, uint64_t start_offset,
+ uint64_t additional_clusters, bool exact_size,
+ int new_refblock_index,
+ uint64_t new_refblock_offset)
+{
+ BDRVQcow2State *s = bs->opaque;
+ uint64_t total_refblock_count_u64, additional_refblock_count;
+ int total_refblock_count, table_size, area_reftable_index, table_clusters;
+ int i;
+ uint64_t table_offset, block_offset, end_offset;
+ int ret;
+ uint64_t *new_table;
- /* Create the new refcount table and blocks */
- uint64_t meta_offset = (blocks_used * s->refcount_block_size) *
- s->cluster_size;
- uint64_t table_offset = meta_offset + blocks_clusters * s->cluster_size;
- uint64_t *new_table = g_try_new0(uint64_t, table_size);
- void *new_blocks = g_try_malloc0(blocks_clusters * s->cluster_size);
+ assert(!(start_offset % s->cluster_size));
- assert(table_size > 0 && blocks_clusters > 0);
- if (new_table == NULL || new_blocks == NULL) {
+ qcow2_refcount_metadata_size(start_offset / s->cluster_size +
+ additional_clusters,
+ s->cluster_size, s->refcount_order,
+ !exact_size, &total_refblock_count_u64);
+ if (total_refblock_count_u64 > QCOW_MAX_REFTABLE_SIZE) {
+ return -EFBIG;
+ }
+ total_refblock_count = total_refblock_count_u64;
+
+ /* Index in the refcount table of the first refcount block to cover the area
+ * of refcount structures we are about to create; we know that
+ * @total_refblock_count can cover @start_offset, so this will definitely
+ * fit into an int. */
+ area_reftable_index = (start_offset / s->cluster_size) /
+ s->refcount_block_size;
+
+ if (exact_size) {
+ table_size = total_refblock_count;
+ } else {
+ table_size = total_refblock_count +
+ DIV_ROUND_UP(total_refblock_count, 2);
+ }
+ /* The qcow2 file can only store the reftable size in number of clusters */
+ table_size = ROUND_UP(table_size, s->cluster_size / sizeof(uint64_t));
+ table_clusters = (table_size * sizeof(uint64_t)) / s->cluster_size;
+
+ if (table_size > QCOW_MAX_REFTABLE_SIZE) {
+ return -EFBIG;
+ }
+
+ new_table = g_try_new0(uint64_t, table_size);
+
+ assert(table_size > 0);
+ if (new_table == NULL) {
ret = -ENOMEM;
- goto fail_table;
+ goto fail;
}
/* Fill the new refcount table */
- memcpy(new_table, s->refcount_table,
- s->refcount_table_size * sizeof(uint64_t));
- new_table[refcount_table_index] = new_block;
+ if (table_size > s->max_refcount_table_index) {
+ /* We're actually growing the reftable */
+ memcpy(new_table, s->refcount_table,
+ (s->max_refcount_table_index + 1) * sizeof(uint64_t));
+ } else {
+ /* Improbable case: We're shrinking the reftable. However, the caller
+ * has assured us that there is only empty space beyond @start_offset,
+ * so we can simply drop all of the refblocks that won't fit into the
+ * new reftable. */
+ memcpy(new_table, s->refcount_table, table_size * sizeof(uint64_t));
+ }
- int i;
- for (i = 0; i < blocks_clusters; i++) {
- new_table[blocks_used + i] = meta_offset + (i * s->cluster_size);
+ if (new_refblock_offset) {
+ assert(new_refblock_index < total_refblock_count);
+ new_table[new_refblock_index] = new_refblock_offset;
+ }
+
+ /* Count how many new refblocks we have to create */
+ additional_refblock_count = 0;
+ for (i = area_reftable_index; i < total_refblock_count; i++) {
+ if (!new_table[i]) {
+ additional_refblock_count++;
+ }
}
- /* Fill the refcount blocks */
- uint64_t table_clusters = size_to_clusters(s, table_size * sizeof(uint64_t));
- int block = 0;
- for (i = 0; i < table_clusters + blocks_clusters; i++) {
- s->set_refcount(new_blocks, block++, 1);
+ table_offset = start_offset + additional_refblock_count * s->cluster_size;
+ end_offset = table_offset + table_clusters * s->cluster_size;
+
+ /* Fill the refcount blocks, and create new ones, if necessary */
+ block_offset = start_offset;
+ for (i = area_reftable_index; i < total_refblock_count; i++) {
+ void *refblock_data;
+ uint64_t first_offset_covered;
+
+ /* Reuse an existing refblock if possible, create a new one otherwise */
+ if (new_table[i]) {
+ ret = qcow2_cache_get(bs, s->refcount_block_cache, new_table[i],
+ &refblock_data);
+ if (ret < 0) {
+ goto fail;
+ }
+ } else {
+ ret = qcow2_cache_get_empty(bs, s->refcount_block_cache,
+ block_offset, &refblock_data);
+ if (ret < 0) {
+ goto fail;
+ }
+ memset(refblock_data, 0, s->cluster_size);
+ qcow2_cache_entry_mark_dirty(s->refcount_block_cache,
+ refblock_data);
+
+ new_table[i] = block_offset;
+ block_offset += s->cluster_size;
+ }
+
+ /* First host offset covered by this refblock */
+ first_offset_covered = (uint64_t)i * s->refcount_block_size *
+ s->cluster_size;
+ if (first_offset_covered < end_offset) {
+ int j, end_index;
+
+ /* Set the refcount of all of the new refcount structures to 1 */
+
+ if (first_offset_covered < start_offset) {
+ assert(i == area_reftable_index);
+ j = (start_offset - first_offset_covered) / s->cluster_size;
+ assert(j < s->refcount_block_size);
+ } else {
+ j = 0;
+ }
+
+ end_index = MIN((end_offset - first_offset_covered) /
+ s->cluster_size,
+ s->refcount_block_size);
+
+ for (; j < end_index; j++) {
+ /* The caller guaranteed us this space would be empty */
+ assert(s->get_refcount(refblock_data, j) == 0);
+ s->set_refcount(refblock_data, j, 1);
+ }
+
+ qcow2_cache_entry_mark_dirty(s->refcount_block_cache,
+ refblock_data);
+ }
+
+ qcow2_cache_put(s->refcount_block_cache, &refblock_data);
}
+ assert(block_offset == table_offset);
+
/* Write refcount blocks to disk */
BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_WRITE_BLOCKS);
- ret = bdrv_pwrite_sync(bs->file, meta_offset, new_blocks,
- blocks_clusters * s->cluster_size);
- g_free(new_blocks);
- new_blocks = NULL;
+ ret = qcow2_cache_flush(bs, s->refcount_block_cache);
if (ret < 0) {
- goto fail_table;
+ goto fail;
}
/* Write refcount table to disk */
- for(i = 0; i < table_size; i++) {
+ for (i = 0; i < total_refblock_count; i++) {
cpu_to_be64s(&new_table[i]);
}
ret = bdrv_pwrite_sync(bs->file, table_offset, new_table,
table_size * sizeof(uint64_t));
if (ret < 0) {
- goto fail_table;
+ goto fail;
}
- for(i = 0; i < table_size; i++) {
+ for (i = 0; i < total_refblock_count; i++) {
be64_to_cpus(&new_table[i]);
}
offsetof(QCowHeader, refcount_table_offset),
&data, sizeof(data));
if (ret < 0) {
- goto fail_table;
+ goto fail;
}
/* And switch it in memory */
s->refcount_table = new_table;
s->refcount_table_size = table_size;
s->refcount_table_offset = table_offset;
+ update_max_refcount_table_index(s);
/* Free old table. */
qcow2_free_clusters(bs, old_table_offset, old_table_size * sizeof(uint64_t),
QCOW2_DISCARD_OTHER);
- ret = load_refcount_block(bs, new_block, refcount_block);
- if (ret < 0) {
- return ret;
- }
-
- /* If we were trying to do the initial refcount update for some cluster
- * allocation, we might have used the same clusters to store newly
- * allocated metadata. Make the caller search some new space. */
- return -EAGAIN;
+ return end_offset;
-fail_table:
- g_free(new_blocks);
+fail:
g_free(new_table);
-fail_block:
- if (*refcount_block != NULL) {
- qcow2_cache_put(bs, s->refcount_block_cache, refcount_block);
- }
return ret;
}
/* Discard is optional, ignore the return value */
if (ret >= 0) {
- bdrv_discard(bs->file->bs,
- d->offset >> BDRV_SECTOR_BITS,
- d->bytes >> BDRV_SECTOR_BITS);
+ bdrv_pdiscard(bs->file->bs, d->offset, d->bytes);
}
g_free(d);
/* Load the refcount block and allocate it if needed */
if (table_index != old_table_index) {
if (refcount_block) {
- qcow2_cache_put(bs, s->refcount_block_cache, &refcount_block);
+ qcow2_cache_put(s->refcount_block_cache, &refcount_block);
}
ret = alloc_refcount_block(bs, cluster_index, &refcount_block);
if (ret < 0) {
}
old_table_index = table_index;
- qcow2_cache_entry_mark_dirty(bs, s->refcount_block_cache,
- refcount_block);
+ qcow2_cache_entry_mark_dirty(s->refcount_block_cache, refcount_block);
/* we can update the count and save it */
block_index = cluster_index & (s->refcount_block_size - 1);
}
s->set_refcount(refcount_block, block_index, refcount);
- if (refcount == 0 && s->discard_passthrough[type]) {
- update_refcount_discard(bs, cluster_offset, s->cluster_size);
+ if (refcount == 0) {
+ void *table;
+
+ table = qcow2_cache_is_table_offset(bs, s->refcount_block_cache,
+ offset);
+ if (table != NULL) {
+ qcow2_cache_put(s->refcount_block_cache, &refcount_block);
+ qcow2_cache_discard(s->refcount_block_cache, table);
+ }
+
+ table = qcow2_cache_is_table_offset(bs, s->l2_table_cache, offset);
+ if (table != NULL) {
+ qcow2_cache_discard(s->l2_table_cache, table);
+ }
+
+ if (s->discard_passthrough[type]) {
+ update_refcount_discard(bs, cluster_offset, s->cluster_size);
+ }
}
}
/* Write last changed block to disk */
if (refcount_block) {
- qcow2_cache_put(bs, s->refcount_block_cache, &refcount_block);
+ qcow2_cache_put(s->refcount_block_cache, &refcount_block);
}
/*
return new_cluster;
}
+ if (new_cluster == 0) {
+ qcow2_signal_corruption(bs, true, -1, -1, "Preventing invalid "
+ "allocation of compressed cluster "
+ "at offset 0");
+ return -EIO;
+ }
+
if (!offset || ROUND_UP(offset, s->cluster_size) != new_cluster) {
offset = new_cluster;
free_in_cluster = s->cluster_size;
}
break;
case QCOW2_CLUSTER_NORMAL:
- case QCOW2_CLUSTER_ZERO:
- if (l2_entry & L2E_OFFSET_MASK) {
- if (offset_into_cluster(s, l2_entry & L2E_OFFSET_MASK)) {
- qcow2_signal_corruption(bs, false, -1, -1,
- "Cannot free unaligned cluster %#llx",
- l2_entry & L2E_OFFSET_MASK);
- } else {
- qcow2_free_clusters(bs, l2_entry & L2E_OFFSET_MASK,
- nb_clusters << s->cluster_bits, type);
- }
+ case QCOW2_CLUSTER_ZERO_ALLOC:
+ if (offset_into_cluster(s, l2_entry & L2E_OFFSET_MASK)) {
+ qcow2_signal_corruption(bs, false, -1, -1,
+ "Cannot free unaligned cluster %#llx",
+ l2_entry & L2E_OFFSET_MASK);
+ } else {
+ qcow2_free_clusters(bs, l2_entry & L2E_OFFSET_MASK,
+ nb_clusters << s->cluster_bits, type);
}
break;
+ case QCOW2_CLUSTER_ZERO_PLAIN:
case QCOW2_CLUSTER_UNALLOCATED:
break;
default:
int64_t l1_table_offset, int l1_size, int addend)
{
BDRVQcow2State *s = bs->opaque;
- uint64_t *l1_table, *l2_table, l2_offset, offset, l1_size2, refcount;
+ uint64_t *l1_table, *l2_table, l2_offset, entry, l1_size2, refcount;
bool l1_allocated = false;
- int64_t old_offset, old_l2_offset;
+ int64_t old_entry, old_l2_offset;
int i, j, l1_modified = 0, nb_csectors;
int ret;
goto fail;
}
- for(i = 0;i < l1_size; i++)
+ for (i = 0; i < l1_size; i++) {
be64_to_cpus(&l1_table[i]);
+ }
} else {
assert(l1_size == s->l1_size);
l1_table = s->l1_table;
l1_allocated = false;
}
- for(i = 0; i < l1_size; i++) {
+ for (i = 0; i < l1_size; i++) {
l2_offset = l1_table[i];
if (l2_offset) {
old_l2_offset = l2_offset;
goto fail;
}
- for(j = 0; j < s->l2_size; j++) {
+ for (j = 0; j < s->l2_size; j++) {
uint64_t cluster_index;
-
- offset = be64_to_cpu(l2_table[j]);
- old_offset = offset;
- offset &= ~QCOW_OFLAG_COPIED;
-
- switch (qcow2_get_cluster_type(offset)) {
- case QCOW2_CLUSTER_COMPRESSED:
- nb_csectors = ((offset >> s->csize_shift) &
- s->csize_mask) + 1;
- if (addend != 0) {
- ret = update_refcount(bs,
- (offset & s->cluster_offset_mask) & ~511,
+ uint64_t offset;
+
+ entry = be64_to_cpu(l2_table[j]);
+ old_entry = entry;
+ entry &= ~QCOW_OFLAG_COPIED;
+ offset = entry & L2E_OFFSET_MASK;
+
+ switch (qcow2_get_cluster_type(entry)) {
+ case QCOW2_CLUSTER_COMPRESSED:
+ nb_csectors = ((entry >> s->csize_shift) &
+ s->csize_mask) + 1;
+ if (addend != 0) {
+ ret = update_refcount(bs,
+ (entry & s->cluster_offset_mask) & ~511,
nb_csectors * 512, abs(addend), addend < 0,
QCOW2_DISCARD_SNAPSHOT);
- if (ret < 0) {
- goto fail;
- }
- }
- /* compressed clusters are never modified */
- refcount = 2;
- break;
-
- case QCOW2_CLUSTER_NORMAL:
- case QCOW2_CLUSTER_ZERO:
- if (offset_into_cluster(s, offset & L2E_OFFSET_MASK)) {
- qcow2_signal_corruption(bs, true, -1, -1, "Data "
- "cluster offset %#llx "
- "unaligned (L2 offset: %#"
- PRIx64 ", L2 index: %#x)",
- offset & L2E_OFFSET_MASK,
- l2_offset, j);
- ret = -EIO;
+ if (ret < 0) {
goto fail;
}
+ }
+ /* compressed clusters are never modified */
+ refcount = 2;
+ break;
+
+ case QCOW2_CLUSTER_NORMAL:
+ case QCOW2_CLUSTER_ZERO_ALLOC:
+ 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);
+ ret = -EIO;
+ goto fail;
+ }
- cluster_index = (offset & L2E_OFFSET_MASK) >> s->cluster_bits;
- if (!cluster_index) {
- /* unallocated */
- refcount = 0;
- break;
- }
- if (addend != 0) {
- ret = qcow2_update_cluster_refcount(bs,
+ cluster_index = offset >> s->cluster_bits;
+ assert(cluster_index);
+ if (addend != 0) {
+ ret = qcow2_update_cluster_refcount(bs,
cluster_index, abs(addend), addend < 0,
QCOW2_DISCARD_SNAPSHOT);
- if (ret < 0) {
- goto fail;
- }
- }
-
- ret = qcow2_get_refcount(bs, cluster_index, &refcount);
if (ret < 0) {
goto fail;
}
- break;
+ }
+
+ ret = qcow2_get_refcount(bs, cluster_index, &refcount);
+ if (ret < 0) {
+ goto fail;
+ }
+ break;
- case QCOW2_CLUSTER_UNALLOCATED:
- refcount = 0;
- break;
+ case QCOW2_CLUSTER_ZERO_PLAIN:
+ case QCOW2_CLUSTER_UNALLOCATED:
+ refcount = 0;
+ break;
- default:
- abort();
+ default:
+ abort();
}
if (refcount == 1) {
- offset |= QCOW_OFLAG_COPIED;
+ entry |= QCOW_OFLAG_COPIED;
}
- if (offset != old_offset) {
+ if (entry != old_entry) {
if (addend > 0) {
qcow2_cache_set_dependency(bs, s->l2_table_cache,
s->refcount_block_cache);
}
- l2_table[j] = cpu_to_be64(offset);
- qcow2_cache_entry_mark_dirty(bs, s->l2_table_cache,
- l2_table);
+ l2_table[j] = cpu_to_be64(entry);
+ qcow2_cache_entry_mark_dirty(s->l2_table_cache, l2_table);
}
}
- qcow2_cache_put(bs, s->l2_table_cache, (void **) &l2_table);
+ qcow2_cache_put(s->l2_table_cache, (void **) &l2_table);
if (addend != 0) {
ret = qcow2_update_cluster_refcount(bs, l2_offset >>
ret = bdrv_flush(bs);
fail:
if (l2_table) {
- qcow2_cache_put(bs, s->l2_table_cache, (void**) &l2_table);
+ qcow2_cache_put(s->l2_table_cache, (void **) &l2_table);
}
s->cache_discards = false;
*
* Modifies the number of errors in res.
*/
-static int inc_refcounts(BlockDriverState *bs,
- BdrvCheckResult *res,
- void **refcount_table,
- int64_t *refcount_table_size,
- int64_t offset, int64_t size)
+int qcow2_inc_refcounts_imrt(BlockDriverState *bs, BdrvCheckResult *res,
+ void **refcount_table,
+ int64_t *refcount_table_size,
+ int64_t offset, int64_t size)
{
BDRVQcow2State *s = bs->opaque;
uint64_t start, last, cluster_offset, k, refcount;
static int check_refcounts_l2(BlockDriverState *bs, BdrvCheckResult *res,
void **refcount_table,
int64_t *refcount_table_size, int64_t l2_offset,
- int flags)
+ int flags, BdrvCheckMode fix)
{
BDRVQcow2State *s = bs->opaque;
uint64_t *l2_table, l2_entry;
nb_csectors = ((l2_entry >> s->csize_shift) &
s->csize_mask) + 1;
l2_entry &= s->cluster_offset_mask;
- ret = inc_refcounts(bs, res, refcount_table, refcount_table_size,
- l2_entry & ~511, nb_csectors * 512);
+ ret = qcow2_inc_refcounts_imrt(bs, res,
+ refcount_table, refcount_table_size,
+ l2_entry & ~511, nb_csectors * 512);
if (ret < 0) {
goto fail;
}
}
break;
- case QCOW2_CLUSTER_ZERO:
- if ((l2_entry & L2E_OFFSET_MASK) == 0) {
- break;
- }
- /* fall through */
-
+ case QCOW2_CLUSTER_ZERO_ALLOC:
case QCOW2_CLUSTER_NORMAL:
{
uint64_t offset = l2_entry & L2E_OFFSET_MASK;
next_contiguous_offset = offset + s->cluster_size;
}
+ /* Correct offsets are cluster aligned */
+ if (offset_into_cluster(s, offset)) {
+ if (qcow2_get_cluster_type(l2_entry) ==
+ QCOW2_CLUSTER_ZERO_ALLOC)
+ {
+ fprintf(stderr, "%s offset=%" PRIx64 ": Preallocated zero "
+ "cluster is not properly aligned; L2 entry "
+ "corrupted.\n",
+ fix & BDRV_FIX_ERRORS ? "Repairing" : "ERROR",
+ offset);
+ if (fix & BDRV_FIX_ERRORS) {
+ uint64_t l2e_offset =
+ l2_offset + (uint64_t)i * sizeof(uint64_t);
+
+ l2_entry = QCOW_OFLAG_ZERO;
+ l2_table[i] = cpu_to_be64(l2_entry);
+ ret = qcow2_pre_write_overlap_check(bs,
+ QCOW2_OL_ACTIVE_L2 | QCOW2_OL_INACTIVE_L2,
+ l2e_offset, sizeof(uint64_t));
+ if (ret < 0) {
+ fprintf(stderr, "ERROR: Overlap check failed\n");
+ res->check_errors++;
+ /* Something is seriously wrong, so abort checking
+ * this L2 table */
+ goto fail;
+ }
+
+ ret = bdrv_pwrite_sync(bs->file, l2e_offset,
+ &l2_table[i], sizeof(uint64_t));
+ if (ret < 0) {
+ fprintf(stderr, "ERROR: Failed to overwrite L2 "
+ "table entry: %s\n", strerror(-ret));
+ res->check_errors++;
+ /* Do not abort, continue checking the rest of this
+ * L2 table's entries */
+ } else {
+ res->corruptions_fixed++;
+ /* Skip marking the cluster as used
+ * (it is unused now) */
+ continue;
+ }
+ } else {
+ res->corruptions++;
+ }
+ } else {
+ fprintf(stderr, "ERROR offset=%" PRIx64 ": Data cluster is "
+ "not properly aligned; L2 entry corrupted.\n", offset);
+ res->corruptions++;
+ }
+ }
+
/* Mark cluster as used */
- ret = inc_refcounts(bs, res, refcount_table, refcount_table_size,
- offset, s->cluster_size);
+ ret = qcow2_inc_refcounts_imrt(bs, res,
+ refcount_table, refcount_table_size,
+ offset, s->cluster_size);
if (ret < 0) {
goto fail;
}
-
- /* Correct offsets are cluster aligned */
- if (offset_into_cluster(s, offset)) {
- fprintf(stderr, "ERROR offset=%" PRIx64 ": Cluster is not "
- "properly aligned; L2 entry corrupted.\n", offset);
- res->corruptions++;
- }
break;
}
+ case QCOW2_CLUSTER_ZERO_PLAIN:
case QCOW2_CLUSTER_UNALLOCATED:
break;
void **refcount_table,
int64_t *refcount_table_size,
int64_t l1_table_offset, int l1_size,
- int flags)
+ int flags, BdrvCheckMode fix)
{
BDRVQcow2State *s = bs->opaque;
uint64_t *l1_table = NULL, l2_offset, l1_size2;
l1_size2 = l1_size * sizeof(uint64_t);
/* Mark L1 table as used */
- ret = inc_refcounts(bs, res, refcount_table, refcount_table_size,
- l1_table_offset, l1_size2);
+ ret = qcow2_inc_refcounts_imrt(bs, res, refcount_table, refcount_table_size,
+ l1_table_offset, l1_size2);
if (ret < 0) {
goto fail;
}
if (l2_offset) {
/* Mark L2 table as used */
l2_offset &= L1E_OFFSET_MASK;
- ret = inc_refcounts(bs, res, refcount_table, refcount_table_size,
- l2_offset, s->cluster_size);
+ ret = qcow2_inc_refcounts_imrt(bs, res,
+ refcount_table, refcount_table_size,
+ l2_offset, s->cluster_size);
if (ret < 0) {
goto fail;
}
/* Process and check L2 entries */
ret = check_refcounts_l2(bs, res, refcount_table,
- refcount_table_size, l2_offset, flags);
+ refcount_table_size, l2_offset, flags,
+ fix);
if (ret < 0) {
goto fail;
}
for (j = 0; j < s->l2_size; j++) {
uint64_t l2_entry = be64_to_cpu(l2_table[j]);
uint64_t data_offset = l2_entry & L2E_OFFSET_MASK;
- int cluster_type = qcow2_get_cluster_type(l2_entry);
+ QCow2ClusterType cluster_type = qcow2_get_cluster_type(l2_entry);
- if ((cluster_type == QCOW2_CLUSTER_NORMAL) ||
- ((cluster_type == QCOW2_CLUSTER_ZERO) && (data_offset != 0))) {
+ if (cluster_type == QCOW2_CLUSTER_NORMAL ||
+ cluster_type == QCOW2_CLUSTER_ZERO_ALLOC) {
ret = qcow2_get_refcount(bs,
data_offset >> s->cluster_bits,
&refcount);
if (fix & BDRV_FIX_ERRORS) {
int64_t new_nb_clusters;
+ Error *local_err = NULL;
if (offset > INT64_MAX - s->cluster_size) {
ret = -EINVAL;
goto resize_fail;
}
- ret = bdrv_truncate(bs->file->bs, offset + s->cluster_size);
+ ret = bdrv_truncate(bs->file, offset + s->cluster_size,
+ PREALLOC_MODE_OFF, &local_err);
if (ret < 0) {
+ error_report_err(local_err);
goto resize_fail;
}
size = bdrv_getlength(bs->file->bs);
}
res->corruptions_fixed++;
- ret = inc_refcounts(bs, res, refcount_table, nb_clusters,
- offset, s->cluster_size);
+ ret = qcow2_inc_refcounts_imrt(bs, res,
+ refcount_table, nb_clusters,
+ offset, s->cluster_size);
if (ret < 0) {
return ret;
}
/* No need to check whether the refcount is now greater than 1:
* This area was just allocated and zeroed, so it can only be
- * exactly 1 after inc_refcounts() */
+ * exactly 1 after qcow2_inc_refcounts_imrt() */
continue;
resize_fail:
}
if (offset != 0) {
- ret = inc_refcounts(bs, res, refcount_table, nb_clusters,
- offset, s->cluster_size);
+ ret = qcow2_inc_refcounts_imrt(bs, res, refcount_table, nb_clusters,
+ offset, s->cluster_size);
if (ret < 0) {
return ret;
}
}
/* header */
- ret = inc_refcounts(bs, res, refcount_table, nb_clusters,
- 0, s->cluster_size);
+ ret = qcow2_inc_refcounts_imrt(bs, res, refcount_table, nb_clusters,
+ 0, s->cluster_size);
if (ret < 0) {
return ret;
}
/* current L1 table */
ret = check_refcounts_l1(bs, res, refcount_table, nb_clusters,
- s->l1_table_offset, s->l1_size, CHECK_FRAG_INFO);
+ s->l1_table_offset, s->l1_size, CHECK_FRAG_INFO,
+ fix);
if (ret < 0) {
return ret;
}
for (i = 0; i < s->nb_snapshots; i++) {
sn = s->snapshots + i;
ret = check_refcounts_l1(bs, res, refcount_table, nb_clusters,
- sn->l1_table_offset, sn->l1_size, 0);
+ sn->l1_table_offset, sn->l1_size, 0, fix);
if (ret < 0) {
return ret;
}
}
- ret = inc_refcounts(bs, res, refcount_table, nb_clusters,
- s->snapshots_offset, s->snapshots_size);
+ ret = qcow2_inc_refcounts_imrt(bs, res, refcount_table, nb_clusters,
+ s->snapshots_offset, s->snapshots_size);
if (ret < 0) {
return ret;
}
/* refcount data */
- ret = inc_refcounts(bs, res, refcount_table, nb_clusters,
- s->refcount_table_offset,
- s->refcount_table_size * sizeof(uint64_t));
+ ret = qcow2_inc_refcounts_imrt(bs, res, refcount_table, nb_clusters,
+ s->refcount_table_offset,
+ s->refcount_table_size * sizeof(uint64_t));
+ if (ret < 0) {
+ return ret;
+ }
+
+ /* encryption */
+ if (s->crypto_header.length) {
+ ret = qcow2_inc_refcounts_imrt(bs, res, refcount_table, nb_clusters,
+ s->crypto_header.offset,
+ s->crypto_header.length);
+ if (ret < 0) {
+ return ret;
+ }
+ }
+
+ /* bitmaps */
+ ret = qcow2_check_bitmaps_refcounts(bs, res, refcount_table, nb_clusters);
if (ret < 0) {
return ret;
}
* this will leak that range, but we can easily fix that by running
* a leak-fixing check after this rebuild operation */
reftable_offset = -1;
+ } else {
+ assert(on_disk_reftable);
}
on_disk_reftable[refblock_index] = refblock_offset;
goto write_refblocks;
}
- assert(on_disk_reftable);
-
for (refblock_index = 0; refblock_index < reftable_size; refblock_index++) {
cpu_to_be64s(&on_disk_reftable[refblock_index]);
}
s->refcount_table = on_disk_reftable;
s->refcount_table_offset = reftable_offset;
s->refcount_table_size = reftable_size;
+ update_max_refcount_table_index(s);
return 0;
}
if ((chk & QCOW2_OL_REFCOUNT_BLOCK) && s->refcount_table) {
- for (i = 0; i < s->refcount_table_size; i++) {
+ unsigned last_entry = s->max_refcount_table_index;
+ assert(last_entry < s->refcount_table_size);
+ assert(last_entry + 1 == s->refcount_table_size ||
+ (s->refcount_table[last_entry + 1] & REFT_OFFSET_MASK) == 0);
+ for (i = 0; i <= last_entry; i++) {
if ((s->refcount_table[i] & REFT_OFFSET_MASK) &&
overlaps_with(s->refcount_table[i] & REFT_OFFSET_MASK,
s->cluster_size)) {
new_reftable_size, new_refblock,
new_refblock_empty, allocated, errp);
if (ret < 0) {
- qcow2_cache_put(bs, s->refcount_block_cache, &refblock);
+ qcow2_cache_put(s->refcount_block_cache, &refblock);
return ret;
}
if (new_refcount_bits < 64 && refcount >> new_refcount_bits) {
uint64_t offset;
- qcow2_cache_put(bs, s->refcount_block_cache, &refblock);
+ qcow2_cache_put(s->refcount_block_cache, &refblock);
offset = ((reftable_index << s->refcount_block_bits)
+ refblock_index) << s->cluster_bits;
new_refblock_empty = new_refblock_empty && refcount == 0;
}
- qcow2_cache_put(bs, s->refcount_block_cache, &refblock);
+ qcow2_cache_put(s->refcount_block_cache, &refblock);
} else {
/* No refblock means every refcount is 0 */
for (refblock_index = 0; refblock_index < s->refcount_block_size;
/* Now update the rest of the in-memory information */
old_reftable = s->refcount_table;
s->refcount_table = new_reftable;
+ update_max_refcount_table_index(s);
s->refcount_bits = 1 << refcount_order;
s->refcount_max = UINT64_C(1) << (s->refcount_bits - 1);
qemu_vfree(new_refblock);
return ret;
}
+
+static int64_t get_refblock_offset(BlockDriverState *bs, uint64_t offset)
+{
+ BDRVQcow2State *s = bs->opaque;
+ uint32_t index = offset_to_reftable_index(s, offset);
+ int64_t covering_refblock_offset = 0;
+
+ if (index < s->refcount_table_size) {
+ covering_refblock_offset = s->refcount_table[index] & REFT_OFFSET_MASK;
+ }
+ if (!covering_refblock_offset) {
+ qcow2_signal_corruption(bs, true, -1, -1, "Refblock at %#" PRIx64 " is "
+ "not covered by the refcount structures",
+ offset);
+ return -EIO;
+ }
+
+ return covering_refblock_offset;
+}
+
+static int qcow2_discard_refcount_block(BlockDriverState *bs,
+ uint64_t discard_block_offs)
+{
+ BDRVQcow2State *s = bs->opaque;
+ int64_t refblock_offs;
+ uint64_t cluster_index = discard_block_offs >> s->cluster_bits;
+ uint32_t block_index = cluster_index & (s->refcount_block_size - 1);
+ void *refblock;
+ int ret;
+
+ refblock_offs = get_refblock_offset(bs, discard_block_offs);
+ if (refblock_offs < 0) {
+ return refblock_offs;
+ }
+
+ assert(discard_block_offs != 0);
+
+ ret = qcow2_cache_get(bs, s->refcount_block_cache, refblock_offs,
+ &refblock);
+ if (ret < 0) {
+ return ret;
+ }
+
+ if (s->get_refcount(refblock, block_index) != 1) {
+ qcow2_signal_corruption(bs, true, -1, -1, "Invalid refcount:"
+ " refblock offset %#" PRIx64
+ ", reftable index %u"
+ ", block offset %#" PRIx64
+ ", refcount %#" PRIx64,
+ refblock_offs,
+ offset_to_reftable_index(s, discard_block_offs),
+ discard_block_offs,
+ s->get_refcount(refblock, block_index));
+ qcow2_cache_put(s->refcount_block_cache, &refblock);
+ return -EINVAL;
+ }
+ s->set_refcount(refblock, block_index, 0);
+
+ qcow2_cache_entry_mark_dirty(s->refcount_block_cache, refblock);
+
+ qcow2_cache_put(s->refcount_block_cache, &refblock);
+
+ if (cluster_index < s->free_cluster_index) {
+ s->free_cluster_index = cluster_index;
+ }
+
+ refblock = qcow2_cache_is_table_offset(bs, s->refcount_block_cache,
+ discard_block_offs);
+ if (refblock) {
+ /* discard refblock from the cache if refblock is cached */
+ qcow2_cache_discard(s->refcount_block_cache, refblock);
+ }
+ update_refcount_discard(bs, discard_block_offs, s->cluster_size);
+
+ return 0;
+}
+
+int qcow2_shrink_reftable(BlockDriverState *bs)
+{
+ BDRVQcow2State *s = bs->opaque;
+ uint64_t *reftable_tmp =
+ g_malloc(s->refcount_table_size * sizeof(uint64_t));
+ int i, ret;
+
+ for (i = 0; i < s->refcount_table_size; i++) {
+ int64_t refblock_offs = s->refcount_table[i] & REFT_OFFSET_MASK;
+ void *refblock;
+ bool unused_block;
+
+ if (refblock_offs == 0) {
+ reftable_tmp[i] = 0;
+ continue;
+ }
+ ret = qcow2_cache_get(bs, s->refcount_block_cache, refblock_offs,
+ &refblock);
+ if (ret < 0) {
+ goto out;
+ }
+
+ /* the refblock has own reference */
+ if (i == offset_to_reftable_index(s, refblock_offs)) {
+ uint64_t block_index = (refblock_offs >> s->cluster_bits) &
+ (s->refcount_block_size - 1);
+ uint64_t refcount = s->get_refcount(refblock, block_index);
+
+ s->set_refcount(refblock, block_index, 0);
+
+ unused_block = buffer_is_zero(refblock, s->cluster_size);
+
+ s->set_refcount(refblock, block_index, refcount);
+ } else {
+ unused_block = buffer_is_zero(refblock, s->cluster_size);
+ }
+ qcow2_cache_put(s->refcount_block_cache, &refblock);
+
+ reftable_tmp[i] = unused_block ? 0 : cpu_to_be64(s->refcount_table[i]);
+ }
+
+ ret = bdrv_pwrite_sync(bs->file, s->refcount_table_offset, reftable_tmp,
+ s->refcount_table_size * sizeof(uint64_t));
+ /*
+ * If the write in the reftable failed the image may contain a partially
+ * overwritten reftable. In this case it would be better to clear the
+ * reftable in memory to avoid possible image corruption.
+ */
+ for (i = 0; i < s->refcount_table_size; i++) {
+ if (s->refcount_table[i] && !reftable_tmp[i]) {
+ if (ret == 0) {
+ ret = qcow2_discard_refcount_block(bs, s->refcount_table[i] &
+ REFT_OFFSET_MASK);
+ }
+ s->refcount_table[i] = 0;
+ }
+ }
+
+ if (!s->cache_discards) {
+ qcow2_process_discards(bs, ret);
+ }
+
+out:
+ g_free(reftable_tmp);
+ return ret;
+}
+
+int64_t qcow2_get_last_cluster(BlockDriverState *bs, int64_t size)
+{
+ BDRVQcow2State *s = bs->opaque;
+ int64_t i;
+
+ for (i = size_to_clusters(s, size) - 1; i >= 0; i--) {
+ uint64_t refcount;
+ int ret = qcow2_get_refcount(bs, i, &refcount);
+ if (ret < 0) {
+ fprintf(stderr, "Can't get refcount for cluster %" PRId64 ": %s\n",
+ i, strerror(-ret));
+ return ret;
+ }
+ if (refcount > 0) {
+ return i;
+ }
+ }
+ qcow2_signal_corruption(bs, true, -1, -1,
+ "There are no references in the refcount table.");
+ return -EIO;
+}
projects / qemu.git / blobdiff