From 51ef67270b1d10e1fcf3de7368dccad1ba0bf9d1 Mon Sep 17 00:00:00 2001 From: edison Date: Tue, 21 Sep 2010 19:58:41 -0700 Subject: Copy snapshots out of QCOW2 disk In order to backup snapshots, created from QCOW2 iamge, we want to copy snapshots out of QCOW2 disk to a seperate storage. The following patch adds a new option in "qemu-img": qemu-img convert -f qcow2 -O qcow2 -s snapshot_name src_img bck_img. Right now, it only supports to copy the full snapshot, delta snapshot is on the way. Changes from V1: all the comments from Kevin are addressed: Add read-only checking Fix coding style Change the name from bdrv_snapshot_load to bdrv_snapshot_load_tmp Signed-off-by: Disheng Su Signed-off-by: Kevin Wolf --- block/qcow2-snapshot.c | 31 +++++++++++++++++++++++++++++++ block/qcow2.c | 1 + block/qcow2.h | 1 + 3 files changed, 33 insertions(+) (limited to 'block') diff --git a/block/qcow2-snapshot.c b/block/qcow2-snapshot.c index 8dd5df0bcd..aacf357821 100644 --- a/block/qcow2-snapshot.c +++ b/block/qcow2-snapshot.c @@ -418,3 +418,34 @@ int qcow2_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab) return s->nb_snapshots; } +int qcow2_snapshot_load_tmp(BlockDriverState *bs, const char *snapshot_name) +{ + int i, snapshot_index, l1_size2; + BDRVQcowState *s = bs->opaque; + QCowSnapshot *sn; + + snapshot_index = find_snapshot_by_id_or_name(bs, snapshot_name); + if (snapshot_index < 0) { + return -ENOENT; + } + + sn = &s->snapshots[snapshot_index]; + s->l1_size = sn->l1_size; + l1_size2 = s->l1_size * sizeof(uint64_t); + if (s->l1_table != NULL) { + qemu_free(s->l1_table); + } + + s->l1_table_offset = sn->l1_table_offset; + s->l1_table = qemu_mallocz(align_offset(l1_size2, 512)); + + if (bdrv_pread(bs->file, sn->l1_table_offset, + s->l1_table, l1_size2) != l1_size2) { + return -1; + } + + for(i = 0;i < s->l1_size; i++) { + be64_to_cpus(&s->l1_table[i]); + } + return 0; +} diff --git a/block/qcow2.c b/block/qcow2.c index 45ed073dbf..b816d8733f 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -1286,6 +1286,7 @@ static BlockDriver bdrv_qcow2 = { .bdrv_snapshot_goto = qcow2_snapshot_goto, .bdrv_snapshot_delete = qcow2_snapshot_delete, .bdrv_snapshot_list = qcow2_snapshot_list, + .bdrv_snapshot_load_tmp = qcow2_snapshot_load_tmp, .bdrv_get_info = qcow_get_info, .bdrv_save_vmstate = qcow_save_vmstate, diff --git a/block/qcow2.h b/block/qcow2.h index add710ba76..2d22e5ec47 100644 --- a/block/qcow2.h +++ b/block/qcow2.h @@ -211,6 +211,7 @@ int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info); int qcow2_snapshot_goto(BlockDriverState *bs, const char *snapshot_id); int qcow2_snapshot_delete(BlockDriverState *bs, const char *snapshot_id); int qcow2_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab); +int qcow2_snapshot_load_tmp(BlockDriverState *bs, const char *snapshot_name); void qcow2_free_snapshots(BlockDriverState *bs); int qcow2_read_snapshots(BlockDriverState *bs); -- cgit v1.2.1