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Re: [Qemu-devel] [Qemu-block] [PATCH v1 1/1] qcow2 resize with snapshots
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From: |
zhangzhiming |
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Subject: |
Re: [Qemu-devel] [Qemu-block] [PATCH v1 1/1] qcow2 resize with snapshots |
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Date: |
Thu, 19 May 2016 16:56:45 +0800 |
hi, missed some code.
zhangzhiming
address@hidden
--
diff --git a/block.c b/block.c
index 047698a..ff83134 100644
--- a/block.c
+++ b/block.c
@@ -2641,7 +2641,7 @@ int bdrv_apply_snapshot(BlockDriverState *bs, const char
*snapshot_id, uint64_t
return ret;
}
- ret = refresh_total_sectors(bs, snapshot_size);
+ ret = refresh_total_sectors(bs, snapshot_size >> BDRV_SECTOR_BITS);
bdrv_dirty_bitmap_truncate(bs);
if (bs->blk) {
blk_dev_resize_cb(bs->blk);
diff --git a/block/qcow2-snapshot.c b/block/qcow2-snapshot.c
index 9bc987f..d872cf2 100644
--- a/block/qcow2-snapshot.c
+++ b/block/qcow2-snapshot.c
@@ -528,6 +528,14 @@ int qcow2_snapshot_goto(BlockDriverState *bs, const char
*snapshot_id)
goto fail;
}
+ /* write updated header.size */
+ uint64_t be_disk_size = cpu_to_be64(sn->disk_size);
+ ret = bdrv_pwrite_sync(bs->file->bs, offsetof(QCowHeader, size),
+ &be_disk_size, sizeof(uint64_t));
+ if (ret < 0) {
+ goto fail;
+ }
+
/*
* Decrease refcount of clusters of current L1 table.
*
--
> On May 19, 2016, at 3:46 PM, zhangzhiming <address@hidden> wrote:
>
> 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
> address@hidden
>
> --
>
> 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
> address@hidden snapshot_goto_blkdev_internal
> address@hidden 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
>
> --
>
>