* THE SOFTWARE.
*/
+#include "qemu/osdep.h"
+#include "qapi/error.h"
#include "qemu-common.h"
#include "block/block_int.h"
#include "block/qcow2.h"
int qcow2_refcount_init(BlockDriverState *bs)
{
- BDRVQcowState *s = bs->opaque;
+ BDRVQcow2State *s = bs->opaque;
unsigned int refcount_table_size2, i;
int ret;
goto fail;
}
BLKDBG_EVENT(bs->file, BLKDBG_REFTABLE_LOAD);
- ret = bdrv_pread(bs->file, s->refcount_table_offset,
+ ret = bdrv_pread(bs->file->bs, s->refcount_table_offset,
s->refcount_table, refcount_table_size2);
if (ret < 0) {
goto fail;
void qcow2_refcount_close(BlockDriverState *bs)
{
- BDRVQcowState *s = bs->opaque;
+ BDRVQcow2State *s = bs->opaque;
g_free(s->refcount_table);
}
int64_t refcount_block_offset,
void **refcount_block)
{
- BDRVQcowState *s = bs->opaque;
+ BDRVQcow2State *s = bs->opaque;
int ret;
BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_LOAD);
int qcow2_get_refcount(BlockDriverState *bs, int64_t cluster_index,
uint64_t *refcount)
{
- BDRVQcowState *s = bs->opaque;
+ BDRVQcow2State *s = bs->opaque;
uint64_t refcount_table_index, block_index;
int64_t refcount_block_offset;
int ret;
* 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(BDRVQcowState *s,
+static unsigned int next_refcount_table_size(BDRVQcow2State *s,
unsigned int min_size)
{
unsigned int min_clusters = (min_size >> (s->cluster_bits - 3)) + 1;
/* Checks if two offsets are described by the same refcount block */
-static int in_same_refcount_block(BDRVQcowState *s, uint64_t offset_a,
+static int in_same_refcount_block(BDRVQcow2State *s, uint64_t offset_a,
uint64_t offset_b)
{
uint64_t block_a = offset_a >> (s->cluster_bits + s->refcount_block_bits);
static int alloc_refcount_block(BlockDriverState *bs,
int64_t cluster_index, void **refcount_block)
{
- BDRVQcowState *s = bs->opaque;
+ BDRVQcow2State *s = bs->opaque;
unsigned int refcount_table_index;
int ret;
if (refcount_table_index < s->refcount_table_size) {
uint64_t data64 = cpu_to_be64(new_block);
BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_HOOKUP);
- ret = bdrv_pwrite_sync(bs->file,
+ ret = bdrv_pwrite_sync(bs->file->bs,
s->refcount_table_offset + refcount_table_index * sizeof(uint64_t),
&data64, sizeof(data64));
if (ret < 0) {
/* Write refcount blocks to disk */
BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_WRITE_BLOCKS);
- ret = bdrv_pwrite_sync(bs->file, meta_offset, new_blocks,
+ ret = bdrv_pwrite_sync(bs->file->bs, meta_offset, new_blocks,
blocks_clusters * s->cluster_size);
g_free(new_blocks);
new_blocks = NULL;
}
BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_WRITE_TABLE);
- ret = bdrv_pwrite_sync(bs->file, table_offset, new_table,
+ ret = bdrv_pwrite_sync(bs->file->bs, table_offset, new_table,
table_size * sizeof(uint64_t));
if (ret < 0) {
goto fail_table;
}
/* Hook up the new refcount table in the qcow2 header */
- uint8_t data[12];
- cpu_to_be64w((uint64_t*)data, table_offset);
- cpu_to_be32w((uint32_t*)(data + 8), table_clusters);
+ struct QEMU_PACKED {
+ uint64_t d64;
+ uint32_t d32;
+ } data;
+ cpu_to_be64w(&data.d64, table_offset);
+ cpu_to_be32w(&data.d32, table_clusters);
BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_SWITCH_TABLE);
- ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, refcount_table_offset),
- data, sizeof(data));
+ ret = bdrv_pwrite_sync(bs->file->bs,
+ offsetof(QCowHeader, refcount_table_offset),
+ &data, sizeof(data));
if (ret < 0) {
goto fail_table;
}
void qcow2_process_discards(BlockDriverState *bs, int ret)
{
- BDRVQcowState *s = bs->opaque;
+ BDRVQcow2State *s = bs->opaque;
Qcow2DiscardRegion *d, *next;
QTAILQ_FOREACH_SAFE(d, &s->discards, next, next) {
/* Discard is optional, ignore the return value */
if (ret >= 0) {
- bdrv_discard(bs->file,
+ bdrv_discard(bs->file->bs,
d->offset >> BDRV_SECTOR_BITS,
d->bytes >> BDRV_SECTOR_BITS);
}
static void update_refcount_discard(BlockDriverState *bs,
uint64_t offset, uint64_t length)
{
- BDRVQcowState *s = bs->opaque;
+ BDRVQcow2State *s = bs->opaque;
Qcow2DiscardRegion *d, *p, *next;
QTAILQ_FOREACH(d, &s->discards, next) {
bool decrease,
enum qcow2_discard_type type)
{
- BDRVQcowState *s = bs->opaque;
+ BDRVQcow2State *s = bs->opaque;
int64_t start, last, cluster_offset;
void *refcount_block = NULL;
int64_t old_table_index = -1;
uint64_t addend, bool decrease,
enum qcow2_discard_type type)
{
- BDRVQcowState *s = bs->opaque;
+ BDRVQcow2State *s = bs->opaque;
int ret;
ret = update_refcount(bs, cluster_index << s->cluster_bits, 1, addend,
/* return < 0 if error */
static int64_t alloc_clusters_noref(BlockDriverState *bs, uint64_t size)
{
- BDRVQcowState *s = bs->opaque;
+ BDRVQcow2State *s = bs->opaque;
uint64_t i, nb_clusters, refcount;
int ret;
return offset;
}
-int qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset,
- int nb_clusters)
+int64_t qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset,
+ int64_t nb_clusters)
{
- BDRVQcowState *s = bs->opaque;
+ BDRVQcow2State *s = bs->opaque;
uint64_t cluster_index, refcount;
uint64_t i;
int ret;
contiguous sectors. size must be <= cluster_size */
int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size)
{
- BDRVQcowState *s = bs->opaque;
+ BDRVQcow2State *s = bs->opaque;
int64_t offset;
size_t free_in_cluster;
int ret;
if (!offset || ROUND_UP(offset, s->cluster_size) != new_cluster) {
offset = new_cluster;
+ free_in_cluster = s->cluster_size;
+ } else {
+ free_in_cluster += s->cluster_size;
}
}
assert(offset);
ret = update_refcount(bs, offset, size, 1, false, QCOW2_DISCARD_NEVER);
+ if (ret < 0) {
+ offset = 0;
+ }
} while (ret == -EAGAIN);
if (ret < 0) {
return ret;
void qcow2_free_any_clusters(BlockDriverState *bs, uint64_t l2_entry,
int nb_clusters, enum qcow2_discard_type type)
{
- BDRVQcowState *s = bs->opaque;
+ BDRVQcow2State *s = bs->opaque;
switch (qcow2_get_cluster_type(l2_entry)) {
case QCOW2_CLUSTER_COMPRESSED:
int qcow2_update_snapshot_refcount(BlockDriverState *bs,
int64_t l1_table_offset, int l1_size, int addend)
{
- BDRVQcowState *s = bs->opaque;
+ BDRVQcow2State *s = bs->opaque;
uint64_t *l1_table, *l2_table, l2_offset, offset, l1_size2, refcount;
bool l1_allocated = false;
int64_t old_offset, old_l2_offset;
}
l1_allocated = true;
- ret = bdrv_pread(bs->file, l1_table_offset, l1_table, l1_size2);
+ ret = bdrv_pread(bs->file->bs, l1_table_offset, l1_table, l1_size2);
if (ret < 0) {
goto fail;
}
cpu_to_be64s(&l1_table[i]);
}
- ret = bdrv_pwrite_sync(bs->file, l1_table_offset, l1_table, l1_size2);
+ ret = bdrv_pwrite_sync(bs->file->bs, l1_table_offset,
+ l1_table, l1_size2);
for (i = 0; i < l1_size; i++) {
be64_to_cpus(&l1_table[i]);
/* refcount checking functions */
-static size_t refcount_array_byte_size(BDRVQcowState *s, uint64_t entries)
+static uint64_t refcount_array_byte_size(BDRVQcow2State *s, uint64_t entries)
{
/* This assertion holds because there is no way we can address more than
* 2^(64 - 9) clusters at once (with cluster size 512 = 2^9, and because
* refcount array buffer will be aligned to a cluster boundary, and the newly
* allocated area will be zeroed.
*/
-static int realloc_refcount_array(BDRVQcowState *s, void **array,
+static int realloc_refcount_array(BDRVQcow2State *s, void **array,
int64_t *size, int64_t new_size)
{
- size_t old_byte_size, new_byte_size;
+ int64_t old_byte_size, new_byte_size;
void *new_ptr;
/* Round to clusters so the array can be directly written to disk */
assert(new_byte_size > 0);
+ if (new_byte_size > SIZE_MAX) {
+ return -ENOMEM;
+ }
+
new_ptr = g_try_realloc(*array, new_byte_size);
if (!new_ptr) {
return -ENOMEM;
}
if (new_byte_size > old_byte_size) {
- memset((void *)((uintptr_t)new_ptr + old_byte_size), 0,
+ memset((char *)new_ptr + old_byte_size, 0,
new_byte_size - old_byte_size);
}
/*
* Increases the refcount for a range of clusters in a given refcount table.
* This is used to construct a temporary refcount table out of L1 and L2 tables
- * which can be compared the the refcount table saved in the image.
+ * which can be compared to the refcount table saved in the image.
*
* Modifies the number of errors in res.
*/
int64_t *refcount_table_size,
int64_t offset, int64_t size)
{
- BDRVQcowState *s = bs->opaque;
+ BDRVQcow2State *s = bs->opaque;
uint64_t start, last, cluster_offset, k, refcount;
int ret;
if (refcount == s->refcount_max) {
fprintf(stderr, "ERROR: overflow cluster offset=0x%" PRIx64
"\n", cluster_offset);
+ fprintf(stderr, "Use qemu-img amend to increase the refcount entry "
+ "width or qemu-img convert to create a clean copy if the "
+ "image cannot be opened for writing\n");
res->corruptions++;
continue;
}
int64_t *refcount_table_size, int64_t l2_offset,
int flags)
{
- BDRVQcowState *s = bs->opaque;
+ BDRVQcow2State *s = bs->opaque;
uint64_t *l2_table, l2_entry;
uint64_t next_contiguous_offset = 0;
int i, l2_size, nb_csectors, ret;
l2_size = s->l2_size * sizeof(uint64_t);
l2_table = g_malloc(l2_size);
- ret = bdrv_pread(bs->file, l2_offset, l2_table, l2_size);
+ ret = bdrv_pread(bs->file->bs, l2_offset, l2_table, l2_size);
if (ret < 0) {
fprintf(stderr, "ERROR: I/O error in check_refcounts_l2\n");
res->check_errors++;
int64_t l1_table_offset, int l1_size,
int flags)
{
- BDRVQcowState *s = bs->opaque;
+ BDRVQcow2State *s = bs->opaque;
uint64_t *l1_table = NULL, l2_offset, l1_size2;
int i, ret;
res->check_errors++;
goto fail;
}
- ret = bdrv_pread(bs->file, l1_table_offset, l1_table, l1_size2);
+ ret = bdrv_pread(bs->file->bs, l1_table_offset, l1_table, l1_size2);
if (ret < 0) {
fprintf(stderr, "ERROR: I/O error in check_refcounts_l1\n");
res->check_errors++;
static int check_oflag_copied(BlockDriverState *bs, BdrvCheckResult *res,
BdrvCheckMode fix)
{
- BDRVQcowState *s = bs->opaque;
+ BDRVQcow2State *s = bs->opaque;
uint64_t *l2_table = qemu_blockalign(bs, s->cluster_size);
int ret;
uint64_t refcount;
}
}
- ret = bdrv_pread(bs->file, l2_offset, l2_table,
+ ret = bdrv_pread(bs->file->bs, l2_offset, l2_table,
s->l2_size * sizeof(uint64_t));
if (ret < 0) {
fprintf(stderr, "ERROR: Could not read L2 table: %s\n",
goto fail;
}
- ret = bdrv_pwrite(bs->file, l2_offset, l2_table, s->cluster_size);
+ ret = bdrv_pwrite(bs->file->bs, l2_offset, l2_table,
+ s->cluster_size);
if (ret < 0) {
fprintf(stderr, "ERROR: Could not write L2 table: %s\n",
strerror(-ret));
BdrvCheckMode fix, bool *rebuild,
void **refcount_table, int64_t *nb_clusters)
{
- BDRVQcowState *s = bs->opaque;
+ BDRVQcow2State *s = bs->opaque;
int64_t i, size;
int ret;
goto resize_fail;
}
- ret = bdrv_truncate(bs->file, offset + s->cluster_size);
+ ret = bdrv_truncate(bs->file->bs, offset + s->cluster_size);
if (ret < 0) {
goto resize_fail;
}
- size = bdrv_getlength(bs->file);
+ size = bdrv_getlength(bs->file->bs);
if (size < 0) {
ret = size;
goto resize_fail;
BdrvCheckMode fix, bool *rebuild,
void **refcount_table, int64_t *nb_clusters)
{
- BDRVQcowState *s = bs->opaque;
+ BDRVQcow2State *s = bs->opaque;
int64_t i;
QCowSnapshot *sn;
int ret;
int64_t *highest_cluster,
void *refcount_table, int64_t nb_clusters)
{
- BDRVQcowState *s = bs->opaque;
+ BDRVQcow2State *s = bs->opaque;
int64_t i;
uint64_t refcount1, refcount2;
int ret;
int64_t *imrt_nb_clusters,
int64_t *first_free_cluster)
{
- BDRVQcowState *s = bs->opaque;
+ BDRVQcow2State *s = bs->opaque;
int64_t cluster = *first_free_cluster, i;
bool first_gap = true;
int contiguous_free_clusters;
void **refcount_table,
int64_t *nb_clusters)
{
- BDRVQcowState *s = bs->opaque;
+ BDRVQcow2State *s = bs->opaque;
int64_t first_free_cluster = 0, reftable_offset = -1, cluster = 0;
int64_t refblock_offset, refblock_start, refblock_index;
uint32_t reftable_size = 0;
on_disk_refblock = (void *)((char *) *refcount_table +
refblock_index * s->cluster_size);
- ret = bdrv_write(bs->file, refblock_offset / BDRV_SECTOR_SIZE,
+ ret = bdrv_write(bs->file->bs, refblock_offset / BDRV_SECTOR_SIZE,
on_disk_refblock, s->cluster_sectors);
if (ret < 0) {
fprintf(stderr, "ERROR writing refblock: %s\n", strerror(-ret));
}
assert(reftable_size < INT_MAX / sizeof(uint64_t));
- ret = bdrv_pwrite(bs->file, reftable_offset, on_disk_reftable,
+ ret = bdrv_pwrite(bs->file->bs, reftable_offset, on_disk_reftable,
reftable_size * sizeof(uint64_t));
if (ret < 0) {
fprintf(stderr, "ERROR writing reftable: %s\n", strerror(-ret));
reftable_offset);
cpu_to_be32w(&reftable_offset_and_clusters.reftable_clusters,
size_to_clusters(s, reftable_size * sizeof(uint64_t)));
- ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader,
- refcount_table_offset),
+ ret = bdrv_pwrite_sync(bs->file->bs, offsetof(QCowHeader,
+ refcount_table_offset),
&reftable_offset_and_clusters,
sizeof(reftable_offset_and_clusters));
if (ret < 0) {
int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
BdrvCheckMode fix)
{
- BDRVQcowState *s = bs->opaque;
+ BDRVQcow2State *s = bs->opaque;
BdrvCheckResult pre_compare_res;
int64_t size, highest_cluster, nb_clusters;
void *refcount_table = NULL;
bool rebuild = false;
int ret;
- size = bdrv_getlength(bs->file);
+ size = bdrv_getlength(bs->file->bs);
if (size < 0) {
res->check_errors++;
return size;
int qcow2_check_metadata_overlap(BlockDriverState *bs, int ign, int64_t offset,
int64_t size)
{
- BDRVQcowState *s = bs->opaque;
+ BDRVQcow2State *s = bs->opaque;
int chk = s->overlap_check & ~ign;
int i, j;
return -ENOMEM;
}
- ret = bdrv_pread(bs->file, l1_ofs, l1, l1_sz2);
+ ret = bdrv_pread(bs->file->bs, l1_ofs, l1, l1_sz2);
if (ret < 0) {
g_free(l1);
return ret;
return 0;
}
+
+/* A pointer to a function of this type is given to walk_over_reftable(). That
+ * function will create refblocks and pass them to a RefblockFinishOp once they
+ * are completed (@refblock). @refblock_empty is set if the refblock is
+ * completely empty.
+ *
+ * Along with the refblock, a corresponding reftable entry is passed, in the
+ * reftable @reftable (which may be reallocated) at @reftable_index.
+ *
+ * @allocated should be set to true if a new cluster has been allocated.
+ */
+typedef int (RefblockFinishOp)(BlockDriverState *bs, uint64_t **reftable,
+ uint64_t reftable_index, uint64_t *reftable_size,
+ void *refblock, bool refblock_empty,
+ bool *allocated, Error **errp);
+
+/**
+ * This "operation" for walk_over_reftable() allocates the refblock on disk (if
+ * it is not empty) and inserts its offset into the new reftable. The size of
+ * this new reftable is increased as required.
+ */
+static int alloc_refblock(BlockDriverState *bs, uint64_t **reftable,
+ uint64_t reftable_index, uint64_t *reftable_size,
+ void *refblock, bool refblock_empty, bool *allocated,
+ Error **errp)
+{
+ BDRVQcow2State *s = bs->opaque;
+ int64_t offset;
+
+ if (!refblock_empty && reftable_index >= *reftable_size) {
+ uint64_t *new_reftable;
+ uint64_t new_reftable_size;
+
+ new_reftable_size = ROUND_UP(reftable_index + 1,
+ s->cluster_size / sizeof(uint64_t));
+ if (new_reftable_size > QCOW_MAX_REFTABLE_SIZE / sizeof(uint64_t)) {
+ error_setg(errp,
+ "This operation would make the refcount table grow "
+ "beyond the maximum size supported by QEMU, aborting");
+ return -ENOTSUP;
+ }
+
+ new_reftable = g_try_realloc(*reftable, new_reftable_size *
+ sizeof(uint64_t));
+ if (!new_reftable) {
+ error_setg(errp, "Failed to increase reftable buffer size");
+ return -ENOMEM;
+ }
+
+ memset(new_reftable + *reftable_size, 0,
+ (new_reftable_size - *reftable_size) * sizeof(uint64_t));
+
+ *reftable = new_reftable;
+ *reftable_size = new_reftable_size;
+ }
+
+ if (!refblock_empty && !(*reftable)[reftable_index]) {
+ offset = qcow2_alloc_clusters(bs, s->cluster_size);
+ if (offset < 0) {
+ error_setg_errno(errp, -offset, "Failed to allocate refblock");
+ return offset;
+ }
+ (*reftable)[reftable_index] = offset;
+ *allocated = true;
+ }
+
+ return 0;
+}
+
+/**
+ * This "operation" for walk_over_reftable() writes the refblock to disk at the
+ * offset specified by the new reftable's entry. It does not modify the new
+ * reftable or change any refcounts.
+ */
+static int flush_refblock(BlockDriverState *bs, uint64_t **reftable,
+ uint64_t reftable_index, uint64_t *reftable_size,
+ void *refblock, bool refblock_empty, bool *allocated,
+ Error **errp)
+{
+ BDRVQcow2State *s = bs->opaque;
+ int64_t offset;
+ int ret;
+
+ if (reftable_index < *reftable_size && (*reftable)[reftable_index]) {
+ offset = (*reftable)[reftable_index];
+
+ ret = qcow2_pre_write_overlap_check(bs, 0, offset, s->cluster_size);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Overlap check failed");
+ return ret;
+ }
+
+ ret = bdrv_pwrite(bs->file->bs, offset, refblock, s->cluster_size);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Failed to write refblock");
+ return ret;
+ }
+ } else {
+ assert(refblock_empty);
+ }
+
+ return 0;
+}
+
+/**
+ * This function walks over the existing reftable and every referenced refblock;
+ * if @new_set_refcount is non-NULL, it is called for every refcount entry to
+ * create an equal new entry in the passed @new_refblock. Once that
+ * @new_refblock is completely filled, @operation will be called.
+ *
+ * @status_cb and @cb_opaque are used for the amend operation's status callback.
+ * @index is the index of the walk_over_reftable() calls and @total is the total
+ * number of walk_over_reftable() calls per amend operation. Both are used for
+ * calculating the parameters for the status callback.
+ *
+ * @allocated is set to true if a new cluster has been allocated.
+ */
+static int walk_over_reftable(BlockDriverState *bs, uint64_t **new_reftable,
+ uint64_t *new_reftable_index,
+ uint64_t *new_reftable_size,
+ void *new_refblock, int new_refblock_size,
+ int new_refcount_bits,
+ RefblockFinishOp *operation, bool *allocated,
+ Qcow2SetRefcountFunc *new_set_refcount,
+ BlockDriverAmendStatusCB *status_cb,
+ void *cb_opaque, int index, int total,
+ Error **errp)
+{
+ BDRVQcow2State *s = bs->opaque;
+ uint64_t reftable_index;
+ bool new_refblock_empty = true;
+ int refblock_index;
+ int new_refblock_index = 0;
+ int ret;
+
+ for (reftable_index = 0; reftable_index < s->refcount_table_size;
+ reftable_index++)
+ {
+ uint64_t refblock_offset = s->refcount_table[reftable_index]
+ & REFT_OFFSET_MASK;
+
+ status_cb(bs, (uint64_t)index * s->refcount_table_size + reftable_index,
+ (uint64_t)total * s->refcount_table_size, cb_opaque);
+
+ if (refblock_offset) {
+ void *refblock;
+
+ if (offset_into_cluster(s, refblock_offset)) {
+ qcow2_signal_corruption(bs, true, -1, -1, "Refblock offset %#"
+ PRIx64 " unaligned (reftable index: %#"
+ PRIx64 ")", refblock_offset,
+ reftable_index);
+ error_setg(errp,
+ "Image is corrupt (unaligned refblock offset)");
+ return -EIO;
+ }
+
+ ret = qcow2_cache_get(bs, s->refcount_block_cache, refblock_offset,
+ &refblock);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Failed to retrieve refblock");
+ return ret;
+ }
+
+ for (refblock_index = 0; refblock_index < s->refcount_block_size;
+ refblock_index++)
+ {
+ uint64_t refcount;
+
+ if (new_refblock_index >= new_refblock_size) {
+ /* new_refblock is now complete */
+ ret = operation(bs, new_reftable, *new_reftable_index,
+ new_reftable_size, new_refblock,
+ new_refblock_empty, allocated, errp);
+ if (ret < 0) {
+ qcow2_cache_put(bs, s->refcount_block_cache, &refblock);
+ return ret;
+ }
+
+ (*new_reftable_index)++;
+ new_refblock_index = 0;
+ new_refblock_empty = true;
+ }
+
+ refcount = s->get_refcount(refblock, refblock_index);
+ if (new_refcount_bits < 64 && refcount >> new_refcount_bits) {
+ uint64_t offset;
+
+ qcow2_cache_put(bs, s->refcount_block_cache, &refblock);
+
+ offset = ((reftable_index << s->refcount_block_bits)
+ + refblock_index) << s->cluster_bits;
+
+ error_setg(errp, "Cannot decrease refcount entry width to "
+ "%i bits: Cluster at offset %#" PRIx64 " has a "
+ "refcount of %" PRIu64, new_refcount_bits,
+ offset, refcount);
+ return -EINVAL;
+ }
+
+ if (new_set_refcount) {
+ new_set_refcount(new_refblock, new_refblock_index++,
+ refcount);
+ } else {
+ new_refblock_index++;
+ }
+ new_refblock_empty = new_refblock_empty && refcount == 0;
+ }
+
+ qcow2_cache_put(bs, s->refcount_block_cache, &refblock);
+ } else {
+ /* No refblock means every refcount is 0 */
+ for (refblock_index = 0; refblock_index < s->refcount_block_size;
+ refblock_index++)
+ {
+ if (new_refblock_index >= new_refblock_size) {
+ /* new_refblock is now complete */
+ ret = operation(bs, new_reftable, *new_reftable_index,
+ new_reftable_size, new_refblock,
+ new_refblock_empty, allocated, errp);
+ if (ret < 0) {
+ return ret;
+ }
+
+ (*new_reftable_index)++;
+ new_refblock_index = 0;
+ new_refblock_empty = true;
+ }
+
+ if (new_set_refcount) {
+ new_set_refcount(new_refblock, new_refblock_index++, 0);
+ } else {
+ new_refblock_index++;
+ }
+ }
+ }
+ }
+
+ if (new_refblock_index > 0) {
+ /* Complete the potentially existing partially filled final refblock */
+ if (new_set_refcount) {
+ for (; new_refblock_index < new_refblock_size;
+ new_refblock_index++)
+ {
+ new_set_refcount(new_refblock, new_refblock_index, 0);
+ }
+ }
+
+ ret = operation(bs, new_reftable, *new_reftable_index,
+ new_reftable_size, new_refblock, new_refblock_empty,
+ allocated, errp);
+ if (ret < 0) {
+ return ret;
+ }
+
+ (*new_reftable_index)++;
+ }
+
+ status_cb(bs, (uint64_t)(index + 1) * s->refcount_table_size,
+ (uint64_t)total * s->refcount_table_size, cb_opaque);
+
+ return 0;
+}
+
+int qcow2_change_refcount_order(BlockDriverState *bs, int refcount_order,
+ BlockDriverAmendStatusCB *status_cb,
+ void *cb_opaque, Error **errp)
+{
+ BDRVQcow2State *s = bs->opaque;
+ Qcow2GetRefcountFunc *new_get_refcount;
+ Qcow2SetRefcountFunc *new_set_refcount;
+ void *new_refblock = qemu_blockalign(bs->file->bs, s->cluster_size);
+ uint64_t *new_reftable = NULL, new_reftable_size = 0;
+ uint64_t *old_reftable, old_reftable_size, old_reftable_offset;
+ uint64_t new_reftable_index = 0;
+ uint64_t i;
+ int64_t new_reftable_offset = 0, allocated_reftable_size = 0;
+ int new_refblock_size, new_refcount_bits = 1 << refcount_order;
+ int old_refcount_order;
+ int walk_index = 0;
+ int ret;
+ bool new_allocation;
+
+ assert(s->qcow_version >= 3);
+ assert(refcount_order >= 0 && refcount_order <= 6);
+
+ /* see qcow2_open() */
+ new_refblock_size = 1 << (s->cluster_bits - (refcount_order - 3));
+
+ new_get_refcount = get_refcount_funcs[refcount_order];
+ new_set_refcount = set_refcount_funcs[refcount_order];
+
+
+ do {
+ int total_walks;
+
+ new_allocation = false;
+
+ /* At least we have to do this walk and the one which writes the
+ * refblocks; also, at least we have to do this loop here at least
+ * twice (normally), first to do the allocations, and second to
+ * determine that everything is correctly allocated, this then makes
+ * three walks in total */
+ total_walks = MAX(walk_index + 2, 3);
+
+ /* First, allocate the structures so they are present in the refcount
+ * structures */
+ ret = walk_over_reftable(bs, &new_reftable, &new_reftable_index,
+ &new_reftable_size, NULL, new_refblock_size,
+ new_refcount_bits, &alloc_refblock,
+ &new_allocation, NULL, status_cb, cb_opaque,
+ walk_index++, total_walks, errp);
+ if (ret < 0) {
+ goto done;
+ }
+
+ new_reftable_index = 0;
+
+ if (new_allocation) {
+ if (new_reftable_offset) {
+ qcow2_free_clusters(bs, new_reftable_offset,
+ allocated_reftable_size * sizeof(uint64_t),
+ QCOW2_DISCARD_NEVER);
+ }
+
+ new_reftable_offset = qcow2_alloc_clusters(bs, new_reftable_size *
+ sizeof(uint64_t));
+ if (new_reftable_offset < 0) {
+ error_setg_errno(errp, -new_reftable_offset,
+ "Failed to allocate the new reftable");
+ ret = new_reftable_offset;
+ goto done;
+ }
+ allocated_reftable_size = new_reftable_size;
+ }
+ } while (new_allocation);
+
+ /* Second, write the new refblocks */
+ ret = walk_over_reftable(bs, &new_reftable, &new_reftable_index,
+ &new_reftable_size, new_refblock,
+ new_refblock_size, new_refcount_bits,
+ &flush_refblock, &new_allocation, new_set_refcount,
+ status_cb, cb_opaque, walk_index, walk_index + 1,
+ errp);
+ if (ret < 0) {
+ goto done;
+ }
+ assert(!new_allocation);
+
+
+ /* Write the new reftable */
+ ret = qcow2_pre_write_overlap_check(bs, 0, new_reftable_offset,
+ new_reftable_size * sizeof(uint64_t));
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Overlap check failed");
+ goto done;
+ }
+
+ for (i = 0; i < new_reftable_size; i++) {
+ cpu_to_be64s(&new_reftable[i]);
+ }
+
+ ret = bdrv_pwrite(bs->file->bs, new_reftable_offset, new_reftable,
+ new_reftable_size * sizeof(uint64_t));
+
+ for (i = 0; i < new_reftable_size; i++) {
+ be64_to_cpus(&new_reftable[i]);
+ }
+
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Failed to write the new reftable");
+ goto done;
+ }
+
+
+ /* Empty the refcount cache */
+ ret = qcow2_cache_flush(bs, s->refcount_block_cache);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Failed to flush the refblock cache");
+ goto done;
+ }
+
+ /* Update the image header to point to the new reftable; this only updates
+ * the fields which are relevant to qcow2_update_header(); other fields
+ * such as s->refcount_table or s->refcount_bits stay stale for now
+ * (because we have to restore everything if qcow2_update_header() fails) */
+ old_refcount_order = s->refcount_order;
+ old_reftable_size = s->refcount_table_size;
+ old_reftable_offset = s->refcount_table_offset;
+
+ s->refcount_order = refcount_order;
+ s->refcount_table_size = new_reftable_size;
+ s->refcount_table_offset = new_reftable_offset;
+
+ ret = qcow2_update_header(bs);
+ if (ret < 0) {
+ s->refcount_order = old_refcount_order;
+ s->refcount_table_size = old_reftable_size;
+ s->refcount_table_offset = old_reftable_offset;
+ error_setg_errno(errp, -ret, "Failed to update the qcow2 header");
+ goto done;
+ }
+
+ /* Now update the rest of the in-memory information */
+ old_reftable = s->refcount_table;
+ s->refcount_table = new_reftable;
+
+ s->refcount_bits = 1 << refcount_order;
+ s->refcount_max = UINT64_C(1) << (s->refcount_bits - 1);
+ s->refcount_max += s->refcount_max - 1;
+
+ s->refcount_block_bits = s->cluster_bits - (refcount_order - 3);
+ s->refcount_block_size = 1 << s->refcount_block_bits;
+
+ s->get_refcount = new_get_refcount;
+ s->set_refcount = new_set_refcount;
+
+ /* For cleaning up all old refblocks and the old reftable below the "done"
+ * label */
+ new_reftable = old_reftable;
+ new_reftable_size = old_reftable_size;
+ new_reftable_offset = old_reftable_offset;
+
+done:
+ if (new_reftable) {
+ /* On success, new_reftable actually points to the old reftable (and
+ * new_reftable_size is the old reftable's size); but that is just
+ * fine */
+ for (i = 0; i < new_reftable_size; i++) {
+ uint64_t offset = new_reftable[i] & REFT_OFFSET_MASK;
+ if (offset) {
+ qcow2_free_clusters(bs, offset, s->cluster_size,
+ QCOW2_DISCARD_OTHER);
+ }
+ }
+ g_free(new_reftable);
+
+ if (new_reftable_offset > 0) {
+ qcow2_free_clusters(bs, new_reftable_offset,
+ new_reftable_size * sizeof(uint64_t),
+ QCOW2_DISCARD_OTHER);
+ }
+ }
+
+ qemu_vfree(new_refblock);
+ return ret;
+}
Code Review / kvmfornfv.git / blobdiff