hi, i wrote some code for 'qcow2 resize' with snapshot with v3 image and 'qcow2
goto’ too,
different size of snapshots are supported.
and i have tested the function and it seems work well.
there are some code copied from snapshot_delete_blkdev_internal, and
qmp_block_resize,
it feels not very good.
please review it for me. thanks.
zhangzhiming
zhangzhimin...@meituan.com
--
diff --git a/block.c b/block.c
index 18a497f..047698a 100644
--- a/block.c
+++ b/block.c
@@ -2632,6 +2632,24 @@ int bdrv_truncate(BlockDriverState *bs, int64_t offset)
}
/**
+ * goto a snapshot
+ */
+int bdrv_apply_snapshot(BlockDriverState *bs, const char *snapshot_id,
uint64_t snapshot_size)
+{
+ int ret = bdrv_snapshot_goto(bs, snapshot_id);
+ if(ret < 0){
+ return ret;
+ }
+
+ ret = refresh_total_sectors(bs, snapshot_size);
+ bdrv_dirty_bitmap_truncate(bs);
+ if (bs->blk) {
+ blk_dev_resize_cb(bs->blk);
+ }
+ return ret;
+}
+
+/**
* Length of a allocated file in bytes. Sparse files are counted by actual
* allocated space. Return < 0 if error or unknown.
*/
diff --git a/block/qcow2-snapshot.c b/block/qcow2-snapshot.c
index 5f4a17e..9bc987f 100644
--- a/block/qcow2-snapshot.c
+++ b/block/qcow2-snapshot.c
@@ -477,13 +477,6 @@ int qcow2_snapshot_goto(BlockDriverState *bs, const char
*snapshot_id)
}
sn = &s->snapshots[snapshot_index];
- if (sn->disk_size != bs->total_sectors * BDRV_SECTOR_SIZE) {
- error_report("qcow2: Loading snapshots with different disk "
- "size is not implemented");
- ret = -ENOTSUP;
- goto fail;
- }
-
/*
* Make sure that the current L1 table is big enough to contain the whole
* L1 table of the snapshot. If the snapshot L1 table is smaller, the
@@ -675,6 +668,7 @@ int qcow2_snapshot_list(BlockDriverState *bs,
QEMUSnapshotInfo **psn_tab)
sn_info->date_sec = sn->date_sec;
sn_info->date_nsec = sn->date_nsec;
sn_info->vm_clock_nsec = sn->vm_clock_nsec;
+ sn_info->disk_size = sn->disk_size;
}
*psn_tab = sn_tab;
return s->nb_snapshots;
diff --git a/block/qcow2.c b/block/qcow2.c
index 62febfc..6535f92 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -2501,15 +2501,17 @@ static int qcow2_truncate(BlockDriverState *bs, int64_t
offset)
return -EINVAL;
}
- /* cannot proceed if image has snapshots */
- if (s->nb_snapshots) {
- error_report("Can't resize an image which has snapshots");
+ bool v3_truncate = (s->qcow_version == 3);
+
+ /* cannot proceed if image has snapshots and qcow_version is not 3*/
+ if (!v3_truncate && s->nb_snapshots) {
+ error_report("Can't resize an image which has snapshots and
qcow_version is not 3");
return -ENOTSUP;
}
- /* shrinking is currently not supported */
- if (offset < bs->total_sectors * 512) {
- error_report("qcow2 doesn't support shrinking images yet");
+ /* shrinking is supported from version 3*/
+ if (!v3_truncate && offset < bs->total_sectors * 512) {
+ error_report("qcow2 doesn't support shrinking images yet while
qcow_version is not 3");
return -ENOTSUP;
}
diff --git a/block/sheepdog.c b/block/sheepdog.c
index 23fbace..bc12f7b 100644
--- a/block/sheepdog.c
+++ b/block/sheepdog.c
@@ -2693,6 +2693,7 @@ static int sd_snapshot_list(BlockDriverState *bs,
QEMUSnapshotInfo **psn_tab)
sn_tab[found].date_nsec = inode.snap_ctime & 0xffffffff;
sn_tab[found].vm_state_size = inode.vm_state_size;
sn_tab[found].vm_clock_nsec = inode.vm_clock_nsec;
+ sn_tab[found].disk_size = inode.vdi_size;
snprintf(sn_tab[found].id_str, sizeof(sn_tab[found].id_str),
"%" PRIu32, inode.snap_id);
diff --git a/blockdev.c b/blockdev.c
index 1892b8e..36c66c1 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -2961,6 +2961,120 @@ out:
aio_context_release(aio_context);
}
+SnapshotInfo *qmp_blockdev_snapshot_goto_internal_sync(const char *device,
+ bool has_id,
+ const char *id,
+ bool has_name,
+ const char *name,
+ Error **errp)
+{
+ BlockDriverState *bs;
+ BlockBackend *blk;
+ AioContext *aio_context;
+ QEMUSnapshotInfo sn;
+ Error *local_err = NULL;
+ SnapshotInfo *info = NULL;
+ int ret;
+
+ blk = blk_by_name(device);
+ if (!blk) {
+ error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
+ "Device '%s' not found", device);
+ return NULL;
+ }
+ aio_context = blk_get_aio_context(blk);
+ aio_context_acquire(aio_context);
+
+ if(!has_id){
+ id = NULL;
+ }
+
+ if(!has_name){
+ name = NULL;
+ }
+
+ if(!id && !name){
+ error_setg(errp, "Name or id must be provided");
+ goto out_aio_context;
+ }
+
+ if(!blk_is_available(blk)){
+ error_setg(errp, "Device '%s' has no medium", device);
+ goto out_aio_context;
+ }
+
+ bs = blk_bs(blk);
+
+ if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_INTERNAL_SNAPSHOT_APPLY, errp)){
+ goto out_aio_context;
+ }
+
+ ret = bdrv_snapshot_find_by_id_and_name(bs, id, name, &sn, &local_err);
+ if(local_err){
+ error_propagate(errp, local_err);
+ goto out_aio_context;
+ }
+ if(!ret){
+ error_setg(errp,
+ "Snapshot with id '%s' and name '%s' does not exist on "
+ "device '%s'",
+ STR_OR_NULL(id), STR_OR_NULL(name), device);
+ goto out_aio_context;
+ }
+ if(!sn.disk_size){
+ error_setg(errp,
+ "Snapshot with id '%s' and name '%s' does not has a disk
size "
+ "device '%s'",
+ STR_OR_NULL(id), STR_OR_NULL(name), device);
+ goto out_aio_context;
+ }
+
+ /* complete all in-flight operations before resizing the device */
+ bdrv_drain_all();
+
+ ret = bdrv_apply_snapshot(bs, sn.id_str, sn.disk_size);
+ switch (ret) {
+ case 0:
+ break;
+ case -ENOMEDIUM:
+ error_setg(errp, QERR_DEVICE_HAS_NO_MEDIUM, device);
+ break;
+ case -ENOTSUP:
+ error_setg(errp, QERR_UNSUPPORTED);
+ break;
+ case -EACCES:
+ error_setg(errp, "Device '%s' is read only", device);
+ break;
+ case -EBUSY:
+ error_setg(errp, QERR_DEVICE_IN_USE, device);
+ break;
+ default:
+ error_setg_errno(errp, -ret, "Could not resize");
+ break;
+ }
+
+ if(ret < 0){
+ goto out_aio_context;
+ }
+
+ aio_context_release(aio_context);
+
+ info = g_new0(SnapshotInfo, 1);
+ info->id = g_strdup(sn.id_str);
+ info->name = g_strdup(sn.name);
+ info->date_nsec = sn.date_nsec;
+ info->date_sec = sn.date_sec;
+ info->vm_state_size = sn.vm_state_size;
+ info->vm_clock_nsec = sn.vm_clock_nsec % 1000000000;
+ info->vm_clock_sec = sn.vm_clock_nsec / 1000000000;
+
+ return info;
+
+out_aio_context:
+ aio_context_release(aio_context);
+ return NULL;
+}
+
static void block_job_cb(void *opaque, int ret)
{
/* Note that this function may be executed from another AioContext besides
diff --git a/hmp-commands.hx b/hmp-commands.hx
index 4f4f60a..5848a57 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -1159,6 +1159,24 @@ Delete an internal snapshot on device if it support
ETEXI
{
+ .name = "snapshot_goto_blkdev_internal",
+ .args_type = "device:B,name:s,id:s?",
+ .params = "device name [id]",
+ .help = "apply an internal snapshot of device.\n\t\t\t"
+ "If id is specified, qemu will try apply\n\t\t\t"
+ "the snapshot matching both id and name.\n\t\t\t"
+ "The format of the image used by device must\n\t\t\t"
+ "support it, such as qcow2.\n\t\t\t",
+ .mhandler.cmd = hmp_snapshot_goto_blkdev_internal,
+ },
+
+STEXI
+@item snapshot_goto_blkdev_internal
+@findex snapshot_goto_blkdev_internal
+Apply an internal snapshot on device if it support
+ETEXI
+
+ {
.name = "drive_mirror",
.args_type = "reuse:-n,full:-f,device:B,target:s,format:s?",
.params = "[-n] [-f] device target [format]",
diff --git a/hmp.c b/hmp.c
index d510236..3f1d146 100644
--- a/hmp.c
+++ b/hmp.c
@@ -1057,6 +1057,8 @@ void hmp_block_resize(Monitor *mon, const QDict *qdict)
hmp_handle_error(mon, &err);
}
+
+
void hmp_drive_mirror(Monitor *mon, const QDict *qdict)
{
const char *device = qdict_get_str(qdict, "device");
@@ -1163,6 +1165,17 @@ void hmp_snapshot_delete_blkdev_internal(Monitor *mon,
const QDict *qdict)
hmp_handle_error(mon, &err);
}
+void hmp_snapshot_goto_blkdev_internal(Monitor *mon, const QDict *qdict)
+{
+ const char *device = qdict_get_str(qdict, "device");
+ const char *name = qdict_get_str(qdict, "name");
+ const char *id = qdict_get_try_str(qdict, "id");
+ Error *err = NULL;
+
+ qmp_blockdev_snapshot_goto_internal_sync(device, !!id, id, true, name,
&err);
+ hmp_handle_error(mon, &err);
+}
+
void hmp_migrate_cancel(Monitor *mon, const QDict *qdict)
{
qmp_migrate_cancel(NULL);
diff --git a/hmp.h b/hmp.h
index 093d65f..b1ad2f5 100644
--- a/hmp.h
+++ b/hmp.h
@@ -59,6 +59,7 @@ void hmp_block_resize(Monitor *mon, const QDict *qdict);
void hmp_snapshot_blkdev(Monitor *mon, const QDict *qdict);
void hmp_snapshot_blkdev_internal(Monitor *mon, const QDict *qdict);
void hmp_snapshot_delete_blkdev_internal(Monitor *mon, const QDict *qdict);
+void hmp_snapshot_goto_blkdev_internal(Monitor *mon, const QDict *qdict);
void hmp_drive_mirror(Monitor *mon, const QDict *qdict);
void hmp_drive_backup(Monitor *mon, const QDict *qdict);
void hmp_migrate_cancel(Monitor *mon, const QDict *qdict);
diff --git a/include/block/block.h b/include/block/block.h
index b210832..393ca6b 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -173,6 +173,7 @@ typedef enum BlockOpType {
BLOCK_OP_TYPE_EXTERNAL_SNAPSHOT,
BLOCK_OP_TYPE_INTERNAL_SNAPSHOT,
BLOCK_OP_TYPE_INTERNAL_SNAPSHOT_DELETE,
+ BLOCK_OP_TYPE_INTERNAL_SNAPSHOT_APPLY,
BLOCK_OP_TYPE_MIRROR_SOURCE,
BLOCK_OP_TYPE_MIRROR_TARGET,
BLOCK_OP_TYPE_RESIZE,
@@ -266,6 +267,7 @@ BlockDriverState *bdrv_find_backing_image(BlockDriverState
*bs,
int bdrv_get_backing_file_depth(BlockDriverState *bs);
void bdrv_refresh_filename(BlockDriverState *bs);
int bdrv_truncate(BlockDriverState *bs, int64_t offset);
+int bdrv_apply_snapshot(BlockDriverState *bs, const char *snapshot_id,
uint64_t snapshot_size);
int64_t bdrv_nb_sectors(BlockDriverState *bs);
int64_t bdrv_getlength(BlockDriverState *bs);
int64_t bdrv_get_allocated_file_size(BlockDriverState *bs);
diff --git a/include/block/snapshot.h b/include/block/snapshot.h
index e5c0553..7279c12 100644
--- a/include/block/snapshot.h
+++ b/include/block/snapshot.h
@@ -44,6 +44,7 @@ typedef struct QEMUSnapshotInfo {
uint32_t date_sec; /* UTC date of the snapshot */
uint32_t date_nsec;
uint64_t vm_clock_nsec; /* VM clock relative to boot */
+ uint64_t disk_size;
} QEMUSnapshotInfo;
int bdrv_snapshot_find(BlockDriverState *bs, QEMUSnapshotInfo *sn_info,
diff --git a/pixman b/pixman
index 87eea99..7c6066b 160000
--- a/pixman
+++ b/pixman
@@ -1 +1 @@
-Subproject commit 87eea99e443b389c978cf37efc52788bf03a0ee0
+Subproject commit 7c6066b700c7cdd4aeb8be426b14b3a5f0de4b6c
--
