int qcow2_snapshot_delete(BlockDriverState *bs, const char *snapshot_id)
{
BDRVQcowState *s = bs->opaque;
QCowSnapshot *sn;
int snapshot_index, ret;
snapshot_index = find_snapshot_by_id_or_name(bs, snapshot_id);
if (snapshot_index < 0)
return -ENOENT;
sn = &s->snapshots[snapshot_index];
ret = qcow2_update_snapshot_refcount(bs, sn->l1_table_offset, sn->l1_size, -1);
if (ret < 0)
return ret;
/* must update the copied flag on the current cluster offsets */
ret = qcow2_update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, 0);
if (ret < 0)
return ret;
qcow2_free_clusters(bs, sn->l1_table_offset, sn->l1_size * sizeof(uint64_t));
g_free(sn->id_str);
g_free(sn->name);
memmove(sn, sn + 1, (s->nb_snapshots - snapshot_index - 1) * sizeof(*sn));
s->nb_snapshots--;
ret = qcow2_write_snapshots(bs);
if (ret < 0) {
/* XXX: restore snapshot if error ? */
return ret;
}
#ifdef DEBUG_ALLOC
qcow2_check_refcounts(bs);
#endif
return 0;
}
int qcow2_snapshot_delete(BlockDriverState *bs, const char *snapshot_id)
{
BDRVQcowState *s = bs->opaque;
QCowSnapshot sn;
int snapshot_index, ret;
/* Search the snapshot */
snapshot_index = find_snapshot_by_id_or_name(bs, snapshot_id);
if (snapshot_index < 0) {
return -ENOENT;
}
sn = s->snapshots[snapshot_index];
/* Remove it from the snapshot list */
memmove(s->snapshots + snapshot_index,
s->snapshots + snapshot_index + 1,
(s->nb_snapshots - snapshot_index - 1) * sizeof(sn));
s->nb_snapshots--;
ret = qcow2_write_snapshots(bs);
if (ret < 0) {
return ret;
}
/*
* The snapshot is now unused, clean up. If we fail after this point, we
* won't recover but just leak clusters.
*/
g_free(sn.id_str);
g_free(sn.name);
/*
* Now decrease the refcounts of clusters referenced by the snapshot and
* free the L1 table.
*/
ret = qcow2_update_snapshot_refcount(bs, sn.l1_table_offset,
sn.l1_size, -1);
if (ret < 0) {
return ret;
}
qcow2_free_clusters(bs, sn.l1_table_offset, sn.l1_size * sizeof(uint64_t),
QCOW2_DISCARD_SNAPSHOT);
/* must update the copied flag on the current cluster offsets */
ret = qcow2_update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, 0);
if (ret < 0) {
return ret;
}
#ifdef DEBUG_ALLOC
{
BdrvCheckResult result = {0};
qcow2_check_refcounts(bs, &result, 0);
}
#endif
return 0;
}
/* if no id is provided, a new one is constructed */
int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info)
{
BDRVQcowState *s = bs->opaque;
QCowSnapshot *new_snapshot_list = NULL;
QCowSnapshot *old_snapshot_list = NULL;
QCowSnapshot sn1, *sn = &sn1;
int i, ret;
uint64_t *l1_table = NULL;
int64_t l1_table_offset;
memset(sn, 0, sizeof(*sn));
/* Generate an ID if it wasn't passed */
if (sn_info->id_str[0] == '\0') {
find_new_snapshot_id(bs, sn_info->id_str, sizeof(sn_info->id_str));
}
/* Check that the ID is unique */
if (find_snapshot_by_id(bs, sn_info->id_str) >= 0) {
return -EEXIST;
}
/* Populate sn with passed data */
sn->id_str = g_strdup(sn_info->id_str);
sn->name = g_strdup(sn_info->name);
sn->disk_size = bs->total_sectors * BDRV_SECTOR_SIZE;
sn->vm_state_size = sn_info->vm_state_size;
sn->date_sec = sn_info->date_sec;
sn->date_nsec = sn_info->date_nsec;
sn->vm_clock_nsec = sn_info->vm_clock_nsec;
/* Allocate the L1 table of the snapshot and copy the current one there. */
l1_table_offset = qcow2_alloc_clusters(bs, s->l1_size * sizeof(uint64_t));
if (l1_table_offset < 0) {
ret = l1_table_offset;
goto fail;
}
sn->l1_table_offset = l1_table_offset;
sn->l1_size = s->l1_size;
l1_table = g_malloc(s->l1_size * sizeof(uint64_t));
for(i = 0; i < s->l1_size; i++) {
l1_table[i] = cpu_to_be64(s->l1_table[i]);
}
ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_DEFAULT,
sn->l1_table_offset, s->l1_size * sizeof(uint64_t));
if (ret < 0) {
goto fail;
}
ret = bdrv_pwrite(bs->file, sn->l1_table_offset, l1_table,
s->l1_size * sizeof(uint64_t));
if (ret < 0) {
goto fail;
}
g_free(l1_table);
l1_table = NULL;
/*
* Increase the refcounts of all clusters and make sure everything is
* stable on disk before updating the snapshot table to contain a pointer
* to the new L1 table.
*/
ret = qcow2_update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, 1);
if (ret < 0) {
goto fail;
}
/* Append the new snapshot to the snapshot list */
new_snapshot_list = g_malloc((s->nb_snapshots + 1) * sizeof(QCowSnapshot));
if (s->snapshots) {
memcpy(new_snapshot_list, s->snapshots,
s->nb_snapshots * sizeof(QCowSnapshot));
old_snapshot_list = s->snapshots;
}
s->snapshots = new_snapshot_list;
s->snapshots[s->nb_snapshots++] = *sn;
ret = qcow2_write_snapshots(bs);
if (ret < 0) {
g_free(s->snapshots);
s->snapshots = old_snapshot_list;
goto fail;
}
g_free(old_snapshot_list);
#ifdef DEBUG_ALLOC
{
BdrvCheckResult result = {0};
qcow2_check_refcounts(bs, &result, 0);
}
#endif
return 0;
fail:
g_free(sn->id_str);
g_free(sn->name);
g_free(l1_table);
return ret;
}
/* if no id is provided, a new one is constructed */
int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info)
{
BDRVQcowState *s = bs->opaque;
QCowSnapshot *snapshots1, sn1, *sn = &sn1;
int i, ret;
uint64_t *l1_table = NULL;
int64_t l1_table_offset;
memset(sn, 0, sizeof(*sn));
if (sn_info->id_str[0] == '\0') {
/* compute a new id */
find_new_snapshot_id(bs, sn_info->id_str, sizeof(sn_info->id_str));
}
/* check that the ID is unique */
if (find_snapshot_by_id(bs, sn_info->id_str) >= 0)
return -ENOENT;
sn->id_str = g_strdup(sn_info->id_str);
if (!sn->id_str)
goto fail;
sn->name = g_strdup(sn_info->name);
if (!sn->name)
goto fail;
sn->vm_state_size = sn_info->vm_state_size;
sn->date_sec = sn_info->date_sec;
sn->date_nsec = sn_info->date_nsec;
sn->vm_clock_nsec = sn_info->vm_clock_nsec;
ret = qcow2_update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, 1);
if (ret < 0)
goto fail;
/* create the L1 table of the snapshot */
l1_table_offset = qcow2_alloc_clusters(bs, s->l1_size * sizeof(uint64_t));
if (l1_table_offset < 0) {
goto fail;
}
bdrv_flush(bs->file);
sn->l1_table_offset = l1_table_offset;
sn->l1_size = s->l1_size;
if (s->l1_size != 0) {
l1_table = g_malloc(s->l1_size * sizeof(uint64_t));
} else {
l1_table = NULL;
}
for(i = 0; i < s->l1_size; i++) {
l1_table[i] = cpu_to_be64(s->l1_table[i]);
}
if (bdrv_pwrite_sync(bs->file, sn->l1_table_offset,
l1_table, s->l1_size * sizeof(uint64_t)) < 0)
goto fail;
g_free(l1_table);
l1_table = NULL;
snapshots1 = g_malloc((s->nb_snapshots + 1) * sizeof(QCowSnapshot));
if (s->snapshots) {
memcpy(snapshots1, s->snapshots, s->nb_snapshots * sizeof(QCowSnapshot));
g_free(s->snapshots);
}
s->snapshots = snapshots1;
s->snapshots[s->nb_snapshots++] = *sn;
if (qcow2_write_snapshots(bs) < 0)
goto fail;
#ifdef DEBUG_ALLOC
qcow2_check_refcounts(bs);
#endif
return 0;
fail:
g_free(sn->name);
g_free(l1_table);
return -1;
}
/* if no id is provided, a new one is constructed */
int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info)
{
BDRVQcow2State *s = bs->opaque;
QCowSnapshot *new_snapshot_list = NULL;
QCowSnapshot *old_snapshot_list = NULL;
QCowSnapshot sn1, *sn = &sn1;
int i, ret;
uint64_t *l1_table = NULL;
int64_t l1_table_offset;
if (s->nb_snapshots >= QCOW_MAX_SNAPSHOTS) {
return -EFBIG;
}
memset(sn, 0, sizeof(*sn));
/* Generate an ID */
find_new_snapshot_id(bs, sn_info->id_str, sizeof(sn_info->id_str));
/* Check that the ID is unique */
if (find_snapshot_by_id_and_name(bs, sn_info->id_str, NULL) >= 0) {
return -EEXIST;
}
/* Populate sn with passed data */
sn->id_str = g_strdup(sn_info->id_str);
sn->name = g_strdup(sn_info->name);
sn->disk_size = bs->total_sectors * BDRV_SECTOR_SIZE;
sn->vm_state_size = sn_info->vm_state_size;
sn->date_sec = sn_info->date_sec;
sn->date_nsec = sn_info->date_nsec;
sn->vm_clock_nsec = sn_info->vm_clock_nsec;
/* Allocate the L1 table of the snapshot and copy the current one there. */
l1_table_offset = qcow2_alloc_clusters(bs, s->l1_size * sizeof(uint64_t));
if (l1_table_offset < 0) {
ret = l1_table_offset;
goto fail;
}
sn->l1_table_offset = l1_table_offset;
sn->l1_size = s->l1_size;
l1_table = g_try_new(uint64_t, s->l1_size);
if (s->l1_size && l1_table == NULL) {
ret = -ENOMEM;
goto fail;
}
for(i = 0; i < s->l1_size; i++) {
l1_table[i] = cpu_to_be64(s->l1_table[i]);
}
ret = qcow2_pre_write_overlap_check(bs, 0, sn->l1_table_offset,
s->l1_size * sizeof(uint64_t));
if (ret < 0) {
goto fail;
}
ret = bdrv_pwrite(bs->file->bs, sn->l1_table_offset, l1_table,
s->l1_size * sizeof(uint64_t));
if (ret < 0) {
goto fail;
}
g_free(l1_table);
l1_table = NULL;
/*
* Increase the refcounts of all clusters and make sure everything is
* stable on disk before updating the snapshot table to contain a pointer
* to the new L1 table.
*/
ret = qcow2_update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, 1);
if (ret < 0) {
goto fail;
}
/* Append the new snapshot to the snapshot list */
new_snapshot_list = g_new(QCowSnapshot, s->nb_snapshots + 1);
if (s->snapshots) {
memcpy(new_snapshot_list, s->snapshots,
s->nb_snapshots * sizeof(QCowSnapshot));
old_snapshot_list = s->snapshots;
}
s->snapshots = new_snapshot_list;
s->snapshots[s->nb_snapshots++] = *sn;
ret = qcow2_write_snapshots(bs);
if (ret < 0) {
g_free(s->snapshots);
s->snapshots = old_snapshot_list;
s->nb_snapshots--;
goto fail;
}
g_free(old_snapshot_list);
/* The VM state isn't needed any more in the active L1 table; in fact, it
* hurts by causing expensive COW for the next snapshot. */
qcow2_discard_clusters(bs, qcow2_vm_state_offset(s),
align_offset(sn->vm_state_size, s->cluster_size)
>> BDRV_SECTOR_BITS,
QCOW2_DISCARD_NEVER, false);
#ifdef DEBUG_ALLOC
{
BdrvCheckResult result = {0};
qcow2_check_refcounts(bs, &result, 0);
}
#endif
return 0;
fail:
g_free(sn->id_str);
g_free(sn->name);
g_free(l1_table);
return ret;
}
