diff options
Diffstat (limited to 'blockdev.c')
| -rw-r--r-- | blockdev.c | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/blockdev.c b/blockdev.c index 2c132a308b..d78aa51af5 100644 --- a/blockdev.c +++ b/blockdev.c @@ -714,6 +714,137 @@ void qmp_blockdev_snapshot_sync(const char *device, const char *snapshot_file, } } + +/* New and old BlockDriverState structs for group snapshots */ +typedef struct BlkGroupSnapshotStates { + BlockDriverState *old_bs; + BlockDriverState *new_bs; + QSIMPLEQ_ENTRY(BlkGroupSnapshotStates) entry; +} BlkGroupSnapshotStates; + +/* + * 'Atomic' group snapshots. The snapshots are taken as a set, and if any fail + * then we do not pivot any of the devices in the group, and abandon the + * snapshots + */ +void qmp_blockdev_group_snapshot_sync(SnapshotDevList *dev_list, + Error **errp) +{ + int ret = 0; + SnapshotDevList *dev_entry = dev_list; + SnapshotDev *dev_info = NULL; + BlkGroupSnapshotStates *states; + BlockDriver *proto_drv; + BlockDriver *drv; + int flags; + const char *format; + const char *snapshot_file; + + QSIMPLEQ_HEAD(snap_bdrv_states, BlkGroupSnapshotStates) snap_bdrv_states; + QSIMPLEQ_INIT(&snap_bdrv_states); + + /* drain all i/o before any snapshots */ + bdrv_drain_all(); + + /* We don't do anything in this loop that commits us to the snapshot */ + while (NULL != dev_entry) { + dev_info = dev_entry->value; + dev_entry = dev_entry->next; + + states = g_malloc0(sizeof(BlkGroupSnapshotStates)); + QSIMPLEQ_INSERT_TAIL(&snap_bdrv_states, states, entry); + + states->old_bs = bdrv_find(dev_info->device); + + if (!states->old_bs) { + error_set(errp, QERR_DEVICE_NOT_FOUND, dev_info->device); + goto delete_and_fail; + } + + if (bdrv_in_use(states->old_bs)) { + error_set(errp, QERR_DEVICE_IN_USE, dev_info->device); + goto delete_and_fail; + } + + if (!bdrv_is_read_only(states->old_bs) && + bdrv_is_inserted(states->old_bs)) { + + if (bdrv_flush(states->old_bs)) { + error_set(errp, QERR_IO_ERROR); + goto delete_and_fail; + } + } + + snapshot_file = dev_info->snapshot_file; + + flags = states->old_bs->open_flags; + + if (!dev_info->has_format) { + format = "qcow2"; + } else { + format = dev_info->format; + } + + drv = bdrv_find_format(format); + if (!drv) { + error_set(errp, QERR_INVALID_BLOCK_FORMAT, format); + goto delete_and_fail; + } + + proto_drv = bdrv_find_protocol(snapshot_file); + if (!proto_drv) { + error_set(errp, QERR_INVALID_BLOCK_FORMAT, format); + goto delete_and_fail; + } + + /* create new image w/backing file */ + ret = bdrv_img_create(snapshot_file, format, + states->old_bs->filename, + drv->format_name, NULL, -1, flags); + if (ret) { + error_set(errp, QERR_OPEN_FILE_FAILED, snapshot_file); + goto delete_and_fail; + } + + /* We will manually add the backing_hd field to the bs later */ + states->new_bs = bdrv_new(""); + ret = bdrv_open(states->new_bs, snapshot_file, + flags | BDRV_O_NO_BACKING, drv); + if (ret != 0) { + error_set(errp, QERR_OPEN_FILE_FAILED, snapshot_file); + goto delete_and_fail; + } + } + + + /* Now we are going to do the actual pivot. Everything up to this point + * is reversible, but we are committed at this point */ + QSIMPLEQ_FOREACH(states, &snap_bdrv_states, entry) { + /* This removes our old bs from the bdrv_states, and adds the new bs */ + bdrv_append(states->new_bs, states->old_bs); + } + + /* success */ + goto exit; + +delete_and_fail: + /* + * failure, and it is all-or-none; abandon each new bs, and keep using + * the original bs for all images + */ + QSIMPLEQ_FOREACH(states, &snap_bdrv_states, entry) { + if (states->new_bs) { + bdrv_delete(states->new_bs); + } + } +exit: + QSIMPLEQ_FOREACH(states, &snap_bdrv_states, entry) { + g_free(states); + } + return; +} + + static void eject_device(BlockDriverState *bs, int force, Error **errp) { if (bdrv_in_use(bs)) { |