qcow2: Split out snapshot functions
qcow2-snapshot.c contains the code related to snapshotting. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This commit is contained in:
Kevin Wolf
Anthony Liguori
parent
45aba42fba
commit
c142442b06
1
Makefile
1
Makefile
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@ -69,6 +69,7 @@ BLOCK_OBJS=cutils.o cache-utils.o qemu-malloc.o qemu-option.o module.o
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BLOCK_OBJS+=block/cow.o block/qcow.o aes.o block/vmdk.o block/cloop.o
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BLOCK_OBJS+=block/dmg.o block/bochs.o block/vpc.o block/vvfat.o
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BLOCK_OBJS+=block/qcow2.o block/qcow2-refcount.o block/qcow2-cluster.o
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BLOCK_OBJS+=block/qcow2-snapshot.o
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BLOCK_OBJS+=block/parallels.o block/nbd.o
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BLOCK_OBJS+=nbd.o block.o aio.o
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@ -0,0 +1,405 @@
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/*
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* Block driver for the QCOW version 2 format
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*
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* Copyright (c) 2004-2006 Fabrice Bellard
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#include "qemu-common.h"
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#include "block_int.h"
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#include "block/qcow2.h"
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typedef struct __attribute__((packed)) QCowSnapshotHeader {
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/* header is 8 byte aligned */
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uint64_t l1_table_offset;
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uint32_t l1_size;
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uint16_t id_str_size;
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uint16_t name_size;
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uint32_t date_sec;
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uint32_t date_nsec;
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uint64_t vm_clock_nsec;
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uint32_t vm_state_size;
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uint32_t extra_data_size; /* for extension */
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/* extra data follows */
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/* id_str follows */
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/* name follows */
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} QCowSnapshotHeader;
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void qcow_free_snapshots(BlockDriverState *bs)
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{
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BDRVQcowState *s = bs->opaque;
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int i;
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for(i = 0; i < s->nb_snapshots; i++) {
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qemu_free(s->snapshots[i].name);
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qemu_free(s->snapshots[i].id_str);
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}
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qemu_free(s->snapshots);
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s->snapshots = NULL;
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s->nb_snapshots = 0;
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}
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int qcow_read_snapshots(BlockDriverState *bs)
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{
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BDRVQcowState *s = bs->opaque;
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QCowSnapshotHeader h;
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QCowSnapshot *sn;
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int i, id_str_size, name_size;
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int64_t offset;
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uint32_t extra_data_size;
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if (!s->nb_snapshots) {
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s->snapshots = NULL;
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s->snapshots_size = 0;
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return 0;
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}
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offset = s->snapshots_offset;
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s->snapshots = qemu_mallocz(s->nb_snapshots * sizeof(QCowSnapshot));
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for(i = 0; i < s->nb_snapshots; i++) {
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offset = align_offset(offset, 8);
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if (bdrv_pread(s->hd, offset, &h, sizeof(h)) != sizeof(h))
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goto fail;
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offset += sizeof(h);
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sn = s->snapshots + i;
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sn->l1_table_offset = be64_to_cpu(h.l1_table_offset);
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sn->l1_size = be32_to_cpu(h.l1_size);
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sn->vm_state_size = be32_to_cpu(h.vm_state_size);
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sn->date_sec = be32_to_cpu(h.date_sec);
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sn->date_nsec = be32_to_cpu(h.date_nsec);
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sn->vm_clock_nsec = be64_to_cpu(h.vm_clock_nsec);
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extra_data_size = be32_to_cpu(h.extra_data_size);
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id_str_size = be16_to_cpu(h.id_str_size);
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name_size = be16_to_cpu(h.name_size);
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offset += extra_data_size;
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sn->id_str = qemu_malloc(id_str_size + 1);
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if (bdrv_pread(s->hd, offset, sn->id_str, id_str_size) != id_str_size)
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goto fail;
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offset += id_str_size;
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sn->id_str[id_str_size] = '\0';
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sn->name = qemu_malloc(name_size + 1);
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if (bdrv_pread(s->hd, offset, sn->name, name_size) != name_size)
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goto fail;
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offset += name_size;
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sn->name[name_size] = '\0';
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}
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s->snapshots_size = offset - s->snapshots_offset;
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return 0;
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fail:
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qcow_free_snapshots(bs);
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return -1;
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}
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/* add at the end of the file a new list of snapshots */
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static int qcow_write_snapshots(BlockDriverState *bs)
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{
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BDRVQcowState *s = bs->opaque;
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QCowSnapshot *sn;
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QCowSnapshotHeader h;
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int i, name_size, id_str_size, snapshots_size;
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uint64_t data64;
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uint32_t data32;
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int64_t offset, snapshots_offset;
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/* compute the size of the snapshots */
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offset = 0;
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for(i = 0; i < s->nb_snapshots; i++) {
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sn = s->snapshots + i;
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offset = align_offset(offset, 8);
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offset += sizeof(h);
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offset += strlen(sn->id_str);
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offset += strlen(sn->name);
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}
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snapshots_size = offset;
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snapshots_offset = alloc_clusters(bs, snapshots_size);
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offset = snapshots_offset;
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for(i = 0; i < s->nb_snapshots; i++) {
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sn = s->snapshots + i;
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memset(&h, 0, sizeof(h));
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h.l1_table_offset = cpu_to_be64(sn->l1_table_offset);
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h.l1_size = cpu_to_be32(sn->l1_size);
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h.vm_state_size = cpu_to_be32(sn->vm_state_size);
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h.date_sec = cpu_to_be32(sn->date_sec);
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h.date_nsec = cpu_to_be32(sn->date_nsec);
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h.vm_clock_nsec = cpu_to_be64(sn->vm_clock_nsec);
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id_str_size = strlen(sn->id_str);
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name_size = strlen(sn->name);
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h.id_str_size = cpu_to_be16(id_str_size);
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h.name_size = cpu_to_be16(name_size);
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offset = align_offset(offset, 8);
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if (bdrv_pwrite(s->hd, offset, &h, sizeof(h)) != sizeof(h))
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goto fail;
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offset += sizeof(h);
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if (bdrv_pwrite(s->hd, offset, sn->id_str, id_str_size) != id_str_size)
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goto fail;
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offset += id_str_size;
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if (bdrv_pwrite(s->hd, offset, sn->name, name_size) != name_size)
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goto fail;
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offset += name_size;
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}
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/* update the various header fields */
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data64 = cpu_to_be64(snapshots_offset);
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if (bdrv_pwrite(s->hd, offsetof(QCowHeader, snapshots_offset),
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&data64, sizeof(data64)) != sizeof(data64))
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goto fail;
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data32 = cpu_to_be32(s->nb_snapshots);
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if (bdrv_pwrite(s->hd, offsetof(QCowHeader, nb_snapshots),
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&data32, sizeof(data32)) != sizeof(data32))
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goto fail;
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/* free the old snapshot table */
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free_clusters(bs, s->snapshots_offset, s->snapshots_size);
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s->snapshots_offset = snapshots_offset;
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s->snapshots_size = snapshots_size;
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return 0;
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fail:
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return -1;
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}
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static void find_new_snapshot_id(BlockDriverState *bs,
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char *id_str, int id_str_size)
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{
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BDRVQcowState *s = bs->opaque;
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QCowSnapshot *sn;
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int i, id, id_max = 0;
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for(i = 0; i < s->nb_snapshots; i++) {
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sn = s->snapshots + i;
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id = strtoul(sn->id_str, NULL, 10);
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if (id > id_max)
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id_max = id;
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}
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snprintf(id_str, id_str_size, "%d", id_max + 1);
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}
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static int find_snapshot_by_id(BlockDriverState *bs, const char *id_str)
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{
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BDRVQcowState *s = bs->opaque;
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int i;
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for(i = 0; i < s->nb_snapshots; i++) {
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if (!strcmp(s->snapshots[i].id_str, id_str))
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return i;
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}
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return -1;
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}
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static int find_snapshot_by_id_or_name(BlockDriverState *bs, const char *name)
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{
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BDRVQcowState *s = bs->opaque;
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int i, ret;
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ret = find_snapshot_by_id(bs, name);
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if (ret >= 0)
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return ret;
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for(i = 0; i < s->nb_snapshots; i++) {
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if (!strcmp(s->snapshots[i].name, name))
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return i;
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}
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return -1;
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}
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/* if no id is provided, a new one is constructed */
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int qcow_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info)
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{
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BDRVQcowState *s = bs->opaque;
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QCowSnapshot *snapshots1, sn1, *sn = &sn1;
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int i, ret;
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uint64_t *l1_table = NULL;
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memset(sn, 0, sizeof(*sn));
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if (sn_info->id_str[0] == '\0') {
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/* compute a new id */
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find_new_snapshot_id(bs, sn_info->id_str, sizeof(sn_info->id_str));
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}
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/* check that the ID is unique */
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if (find_snapshot_by_id(bs, sn_info->id_str) >= 0)
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return -ENOENT;
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sn->id_str = qemu_strdup(sn_info->id_str);
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if (!sn->id_str)
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goto fail;
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sn->name = qemu_strdup(sn_info->name);
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if (!sn->name)
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goto fail;
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sn->vm_state_size = sn_info->vm_state_size;
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sn->date_sec = sn_info->date_sec;
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sn->date_nsec = sn_info->date_nsec;
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sn->vm_clock_nsec = sn_info->vm_clock_nsec;
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ret = update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, 1);
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if (ret < 0)
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goto fail;
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/* create the L1 table of the snapshot */
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sn->l1_table_offset = alloc_clusters(bs, s->l1_size * sizeof(uint64_t));
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sn->l1_size = s->l1_size;
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l1_table = qemu_malloc(s->l1_size * sizeof(uint64_t));
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for(i = 0; i < s->l1_size; i++) {
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l1_table[i] = cpu_to_be64(s->l1_table[i]);
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}
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if (bdrv_pwrite(s->hd, sn->l1_table_offset,
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l1_table, s->l1_size * sizeof(uint64_t)) !=
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(s->l1_size * sizeof(uint64_t)))
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goto fail;
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qemu_free(l1_table);
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l1_table = NULL;
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snapshots1 = qemu_malloc((s->nb_snapshots + 1) * sizeof(QCowSnapshot));
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if (s->snapshots) {
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memcpy(snapshots1, s->snapshots, s->nb_snapshots * sizeof(QCowSnapshot));
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qemu_free(s->snapshots);
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}
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s->snapshots = snapshots1;
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s->snapshots[s->nb_snapshots++] = *sn;
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if (qcow_write_snapshots(bs) < 0)
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goto fail;
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#ifdef DEBUG_ALLOC
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check_refcounts(bs);
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#endif
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return 0;
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fail:
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qemu_free(sn->name);
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qemu_free(l1_table);
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return -1;
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}
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/* copy the snapshot 'snapshot_name' into the current disk image */
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int qcow_snapshot_goto(BlockDriverState *bs, const char *snapshot_id)
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{
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BDRVQcowState *s = bs->opaque;
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QCowSnapshot *sn;
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int i, snapshot_index, l1_size2;
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snapshot_index = find_snapshot_by_id_or_name(bs, snapshot_id);
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if (snapshot_index < 0)
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return -ENOENT;
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sn = &s->snapshots[snapshot_index];
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if (update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, -1) < 0)
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goto fail;
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if (grow_l1_table(bs, sn->l1_size) < 0)
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goto fail;
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s->l1_size = sn->l1_size;
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l1_size2 = s->l1_size * sizeof(uint64_t);
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/* copy the snapshot l1 table to the current l1 table */
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if (bdrv_pread(s->hd, sn->l1_table_offset,
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s->l1_table, l1_size2) != l1_size2)
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goto fail;
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if (bdrv_pwrite(s->hd, s->l1_table_offset,
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s->l1_table, l1_size2) != l1_size2)
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goto fail;
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for(i = 0;i < s->l1_size; i++) {
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be64_to_cpus(&s->l1_table[i]);
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}
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if (update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, 1) < 0)
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goto fail;
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#ifdef DEBUG_ALLOC
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check_refcounts(bs);
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#endif
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return 0;
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fail:
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return -EIO;
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}
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int qcow_snapshot_delete(BlockDriverState *bs, const char *snapshot_id)
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{
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BDRVQcowState *s = bs->opaque;
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QCowSnapshot *sn;
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int snapshot_index, ret;
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snapshot_index = find_snapshot_by_id_or_name(bs, snapshot_id);
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if (snapshot_index < 0)
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return -ENOENT;
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sn = &s->snapshots[snapshot_index];
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ret = update_snapshot_refcount(bs, sn->l1_table_offset, sn->l1_size, -1);
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if (ret < 0)
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return ret;
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/* must update the copied flag on the current cluster offsets */
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ret = update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, 0);
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if (ret < 0)
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return ret;
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free_clusters(bs, sn->l1_table_offset, sn->l1_size * sizeof(uint64_t));
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qemu_free(sn->id_str);
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qemu_free(sn->name);
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memmove(sn, sn + 1, (s->nb_snapshots - snapshot_index - 1) * sizeof(*sn));
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s->nb_snapshots--;
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ret = qcow_write_snapshots(bs);
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if (ret < 0) {
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/* XXX: restore snapshot if error ? */
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return ret;
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}
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#ifdef DEBUG_ALLOC
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check_refcounts(bs);
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#endif
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return 0;
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}
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int qcow_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab)
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{
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BDRVQcowState *s = bs->opaque;
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QEMUSnapshotInfo *sn_tab, *sn_info;
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QCowSnapshot *sn;
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int i;
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if (!s->nb_snapshots) {
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*psn_tab = NULL;
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return s->nb_snapshots;
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}
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sn_tab = qemu_mallocz(s->nb_snapshots * sizeof(QEMUSnapshotInfo));
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for(i = 0; i < s->nb_snapshots; i++) {
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sn_info = sn_tab + i;
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sn = s->snapshots + i;
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pstrcpy(sn_info->id_str, sizeof(sn_info->id_str),
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sn->id_str);
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pstrcpy(sn_info->name, sizeof(sn_info->name),
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sn->name);
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sn_info->vm_state_size = sn->vm_state_size;
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sn_info->date_sec = sn->date_sec;
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sn_info->date_nsec = sn->date_nsec;
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sn_info->vm_clock_nsec = sn->vm_clock_nsec;
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}
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*psn_tab = sn_tab;
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return s->nb_snapshots;
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}
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392
block/qcow2.c
392
block/qcow2.c
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@ -57,29 +57,6 @@ typedef struct {
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#define QCOW_EXT_MAGIC_BACKING_FORMAT 0xE2792ACA
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|
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|
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typedef struct __attribute__((packed)) QCowSnapshotHeader {
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/* header is 8 byte aligned */
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uint64_t l1_table_offset;
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|
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uint32_t l1_size;
|
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uint16_t id_str_size;
|
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uint16_t name_size;
|
||||
|
||||
uint32_t date_sec;
|
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uint32_t date_nsec;
|
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|
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uint64_t vm_clock_nsec;
|
||||
|
||||
uint32_t vm_state_size;
|
||||
uint32_t extra_data_size; /* for extension */
|
||||
/* extra data follows */
|
||||
/* id_str follows */
|
||||
/* name follows */
|
||||
} QCowSnapshotHeader;
|
||||
|
||||
|
||||
static int qcow_read_snapshots(BlockDriverState *bs);
|
||||
static void qcow_free_snapshots(BlockDriverState *bs);
|
||||
|
||||
static int qcow_probe(const uint8_t *buf, int buf_size, const char *filename)
|
||||
{
|
||||
|
|
@ -331,12 +308,6 @@ static int qcow_set_key(BlockDriverState *bs, const char *key)
|
|||
return 0;
|
||||
}
|
||||
|
||||
static int64_t align_offset(int64_t offset, int n)
|
||||
{
|
||||
offset = (offset + n - 1) & ~(n - 1);
|
||||
return offset;
|
||||
}
|
||||
|
||||
static int qcow_is_allocated(BlockDriverState *bs, int64_t sector_num,
|
||||
int nb_sectors, int *pnum)
|
||||
{
|
||||
|
|
@ -936,369 +907,6 @@ static int qcow_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
|
|||
return 0;
|
||||
}
|
||||
|
||||
/*********************************************************/
|
||||
/* snapshot support */
|
||||
|
||||
|
||||
static void qcow_free_snapshots(BlockDriverState *bs)
|
||||
{
|
||||
BDRVQcowState *s = bs->opaque;
|
||||
int i;
|
||||
|
||||
for(i = 0; i < s->nb_snapshots; i++) {
|
||||
qemu_free(s->snapshots[i].name);
|
||||
qemu_free(s->snapshots[i].id_str);
|
||||
}
|
||||
qemu_free(s->snapshots);
|
||||
s->snapshots = NULL;
|
||||
s->nb_snapshots = 0;
|
||||
}
|
||||
|
||||
static int qcow_read_snapshots(BlockDriverState *bs)
|
||||
{
|
||||
BDRVQcowState *s = bs->opaque;
|
||||
QCowSnapshotHeader h;
|
||||
QCowSnapshot *sn;
|
||||
int i, id_str_size, name_size;
|
||||
int64_t offset;
|
||||
uint32_t extra_data_size;
|
||||
|
||||
if (!s->nb_snapshots) {
|
||||
s->snapshots = NULL;
|
||||
s->snapshots_size = 0;
|
||||
return 0;
|
||||
}
|
||||
|
||||
offset = s->snapshots_offset;
|
||||
s->snapshots = qemu_mallocz(s->nb_snapshots * sizeof(QCowSnapshot));
|
||||
for(i = 0; i < s->nb_snapshots; i++) {
|
||||
offset = align_offset(offset, 8);
|
||||
if (bdrv_pread(s->hd, offset, &h, sizeof(h)) != sizeof(h))
|
||||
goto fail;
|
||||
offset += sizeof(h);
|
||||
sn = s->snapshots + i;
|
||||
sn->l1_table_offset = be64_to_cpu(h.l1_table_offset);
|
||||
sn->l1_size = be32_to_cpu(h.l1_size);
|
||||
sn->vm_state_size = be32_to_cpu(h.vm_state_size);
|
||||
sn->date_sec = be32_to_cpu(h.date_sec);
|
||||
sn->date_nsec = be32_to_cpu(h.date_nsec);
|
||||
sn->vm_clock_nsec = be64_to_cpu(h.vm_clock_nsec);
|
||||
extra_data_size = be32_to_cpu(h.extra_data_size);
|
||||
|
||||
id_str_size = be16_to_cpu(h.id_str_size);
|
||||
name_size = be16_to_cpu(h.name_size);
|
||||
|
||||
offset += extra_data_size;
|
||||
|
||||
sn->id_str = qemu_malloc(id_str_size + 1);
|
||||
if (bdrv_pread(s->hd, offset, sn->id_str, id_str_size) != id_str_size)
|
||||
goto fail;
|
||||
offset += id_str_size;
|
||||
sn->id_str[id_str_size] = '\0';
|
||||
|
||||
sn->name = qemu_malloc(name_size + 1);
|
||||
if (bdrv_pread(s->hd, offset, sn->name, name_size) != name_size)
|
||||
goto fail;
|
||||
offset += name_size;
|
||||
sn->name[name_size] = '\0';
|
||||
}
|
||||
s->snapshots_size = offset - s->snapshots_offset;
|
||||
return 0;
|
||||
fail:
|
||||
qcow_free_snapshots(bs);
|
||||
return -1;
|
||||
}
|
||||
|
||||
/* add at the end of the file a new list of snapshots */
|
||||
static int qcow_write_snapshots(BlockDriverState *bs)
|
||||
{
|
||||
BDRVQcowState *s = bs->opaque;
|
||||
QCowSnapshot *sn;
|
||||
QCowSnapshotHeader h;
|
||||
int i, name_size, id_str_size, snapshots_size;
|
||||
uint64_t data64;
|
||||
uint32_t data32;
|
||||
int64_t offset, snapshots_offset;
|
||||
|
||||
/* compute the size of the snapshots */
|
||||
offset = 0;
|
||||
for(i = 0; i < s->nb_snapshots; i++) {
|
||||
sn = s->snapshots + i;
|
||||
offset = align_offset(offset, 8);
|
||||
offset += sizeof(h);
|
||||
offset += strlen(sn->id_str);
|
||||
offset += strlen(sn->name);
|
||||
}
|
||||
snapshots_size = offset;
|
||||
|
||||
snapshots_offset = alloc_clusters(bs, snapshots_size);
|
||||
offset = snapshots_offset;
|
||||
|
||||
for(i = 0; i < s->nb_snapshots; i++) {
|
||||
sn = s->snapshots + i;
|
||||
memset(&h, 0, sizeof(h));
|
||||
h.l1_table_offset = cpu_to_be64(sn->l1_table_offset);
|
||||
h.l1_size = cpu_to_be32(sn->l1_size);
|
||||
h.vm_state_size = cpu_to_be32(sn->vm_state_size);
|
||||
h.date_sec = cpu_to_be32(sn->date_sec);
|
||||
h.date_nsec = cpu_to_be32(sn->date_nsec);
|
||||
h.vm_clock_nsec = cpu_to_be64(sn->vm_clock_nsec);
|
||||
|
||||
id_str_size = strlen(sn->id_str);
|
||||
name_size = strlen(sn->name);
|
||||
h.id_str_size = cpu_to_be16(id_str_size);
|
||||
h.name_size = cpu_to_be16(name_size);
|
||||
offset = align_offset(offset, 8);
|
||||
if (bdrv_pwrite(s->hd, offset, &h, sizeof(h)) != sizeof(h))
|
||||
goto fail;
|
||||
offset += sizeof(h);
|
||||
if (bdrv_pwrite(s->hd, offset, sn->id_str, id_str_size) != id_str_size)
|
||||
goto fail;
|
||||
offset += id_str_size;
|
||||
if (bdrv_pwrite(s->hd, offset, sn->name, name_size) != name_size)
|
||||
goto fail;
|
||||
offset += name_size;
|
||||
}
|
||||
|
||||
/* update the various header fields */
|
||||
data64 = cpu_to_be64(snapshots_offset);
|
||||
if (bdrv_pwrite(s->hd, offsetof(QCowHeader, snapshots_offset),
|
||||
&data64, sizeof(data64)) != sizeof(data64))
|
||||
goto fail;
|
||||
data32 = cpu_to_be32(s->nb_snapshots);
|
||||
if (bdrv_pwrite(s->hd, offsetof(QCowHeader, nb_snapshots),
|
||||
&data32, sizeof(data32)) != sizeof(data32))
|
||||
goto fail;
|
||||
|
||||
/* free the old snapshot table */
|
||||
free_clusters(bs, s->snapshots_offset, s->snapshots_size);
|
||||
s->snapshots_offset = snapshots_offset;
|
||||
s->snapshots_size = snapshots_size;
|
||||
return 0;
|
||||
fail:
|
||||
return -1;
|
||||
}
|
||||
|
||||
static void find_new_snapshot_id(BlockDriverState *bs,
|
||||
char *id_str, int id_str_size)
|
||||
{
|
||||
BDRVQcowState *s = bs->opaque;
|
||||
QCowSnapshot *sn;
|
||||
int i, id, id_max = 0;
|
||||
|
||||
for(i = 0; i < s->nb_snapshots; i++) {
|
||||
sn = s->snapshots + i;
|
||||
id = strtoul(sn->id_str, NULL, 10);
|
||||
if (id > id_max)
|
||||
id_max = id;
|
||||
}
|
||||
snprintf(id_str, id_str_size, "%d", id_max + 1);
|
||||
}
|
||||
|
||||
static int find_snapshot_by_id(BlockDriverState *bs, const char *id_str)
|
||||
{
|
||||
BDRVQcowState *s = bs->opaque;
|
||||
int i;
|
||||
|
||||
for(i = 0; i < s->nb_snapshots; i++) {
|
||||
if (!strcmp(s->snapshots[i].id_str, id_str))
|
||||
return i;
|
||||
}
|
||||
return -1;
|
||||
}
|
||||
|
||||
static int find_snapshot_by_id_or_name(BlockDriverState *bs, const char *name)
|
||||
{
|
||||
BDRVQcowState *s = bs->opaque;
|
||||
int i, ret;
|
||||
|
||||
ret = find_snapshot_by_id(bs, name);
|
||||
if (ret >= 0)
|
||||
return ret;
|
||||
for(i = 0; i < s->nb_snapshots; i++) {
|
||||
if (!strcmp(s->snapshots[i].name, name))
|
||||
return i;
|
||||
}
|
||||
return -1;
|
||||
}
|
||||
|
||||
/* if no id is provided, a new one is constructed */
|
||||
static int qcow_snapshot_create(BlockDriverState *bs,
|
||||
QEMUSnapshotInfo *sn_info)
|
||||
{
|
||||
BDRVQcowState *s = bs->opaque;
|
||||
QCowSnapshot *snapshots1, sn1, *sn = &sn1;
|
||||
int i, ret;
|
||||
uint64_t *l1_table = NULL;
|
||||
|
||||
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 = qemu_strdup(sn_info->id_str);
|
||||
if (!sn->id_str)
|
||||
goto fail;
|
||||
sn->name = qemu_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 = update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, 1);
|
||||
if (ret < 0)
|
||||
goto fail;
|
||||
|
||||
/* create the L1 table of the snapshot */
|
||||
sn->l1_table_offset = alloc_clusters(bs, s->l1_size * sizeof(uint64_t));
|
||||
sn->l1_size = s->l1_size;
|
||||
|
||||
l1_table = qemu_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]);
|
||||
}
|
||||
if (bdrv_pwrite(s->hd, sn->l1_table_offset,
|
||||
l1_table, s->l1_size * sizeof(uint64_t)) !=
|
||||
(s->l1_size * sizeof(uint64_t)))
|
||||
goto fail;
|
||||
qemu_free(l1_table);
|
||||
l1_table = NULL;
|
||||
|
||||
snapshots1 = qemu_malloc((s->nb_snapshots + 1) * sizeof(QCowSnapshot));
|
||||
if (s->snapshots) {
|
||||
memcpy(snapshots1, s->snapshots, s->nb_snapshots * sizeof(QCowSnapshot));
|
||||
qemu_free(s->snapshots);
|
||||
}
|
||||
s->snapshots = snapshots1;
|
||||
s->snapshots[s->nb_snapshots++] = *sn;
|
||||
|
||||
if (qcow_write_snapshots(bs) < 0)
|
||||
goto fail;
|
||||
#ifdef DEBUG_ALLOC
|
||||
check_refcounts(bs);
|
||||
#endif
|
||||
return 0;
|
||||
fail:
|
||||
qemu_free(sn->name);
|
||||
qemu_free(l1_table);
|
||||
return -1;
|
||||
}
|
||||
|
||||
/* copy the snapshot 'snapshot_name' into the current disk image */
|
||||
static int qcow_snapshot_goto(BlockDriverState *bs,
|
||||
const char *snapshot_id)
|
||||
{
|
||||
BDRVQcowState *s = bs->opaque;
|
||||
QCowSnapshot *sn;
|
||||
int i, snapshot_index, l1_size2;
|
||||
|
||||
snapshot_index = find_snapshot_by_id_or_name(bs, snapshot_id);
|
||||
if (snapshot_index < 0)
|
||||
return -ENOENT;
|
||||
sn = &s->snapshots[snapshot_index];
|
||||
|
||||
if (update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, -1) < 0)
|
||||
goto fail;
|
||||
|
||||
if (grow_l1_table(bs, sn->l1_size) < 0)
|
||||
goto fail;
|
||||
|
||||
s->l1_size = sn->l1_size;
|
||||
l1_size2 = s->l1_size * sizeof(uint64_t);
|
||||
/* copy the snapshot l1 table to the current l1 table */
|
||||
if (bdrv_pread(s->hd, sn->l1_table_offset,
|
||||
s->l1_table, l1_size2) != l1_size2)
|
||||
goto fail;
|
||||
if (bdrv_pwrite(s->hd, s->l1_table_offset,
|
||||
s->l1_table, l1_size2) != l1_size2)
|
||||
goto fail;
|
||||
for(i = 0;i < s->l1_size; i++) {
|
||||
be64_to_cpus(&s->l1_table[i]);
|
||||
}
|
||||
|
||||
if (update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, 1) < 0)
|
||||
goto fail;
|
||||
|
||||
#ifdef DEBUG_ALLOC
|
||||
check_refcounts(bs);
|
||||
#endif
|
||||
return 0;
|
||||
fail:
|
||||
return -EIO;
|
||||
}
|
||||
|
||||
static int qcow_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 = 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 = update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, 0);
|
||||
if (ret < 0)
|
||||
return ret;
|
||||
free_clusters(bs, sn->l1_table_offset, sn->l1_size * sizeof(uint64_t));
|
||||
|
||||
qemu_free(sn->id_str);
|
||||
qemu_free(sn->name);
|
||||
memmove(sn, sn + 1, (s->nb_snapshots - snapshot_index - 1) * sizeof(*sn));
|
||||
s->nb_snapshots--;
|
||||
ret = qcow_write_snapshots(bs);
|
||||
if (ret < 0) {
|
||||
/* XXX: restore snapshot if error ? */
|
||||
return ret;
|
||||
}
|
||||
#ifdef DEBUG_ALLOC
|
||||
check_refcounts(bs);
|
||||
#endif
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int qcow_snapshot_list(BlockDriverState *bs,
|
||||
QEMUSnapshotInfo **psn_tab)
|
||||
{
|
||||
BDRVQcowState *s = bs->opaque;
|
||||
QEMUSnapshotInfo *sn_tab, *sn_info;
|
||||
QCowSnapshot *sn;
|
||||
int i;
|
||||
|
||||
if (!s->nb_snapshots) {
|
||||
*psn_tab = NULL;
|
||||
return s->nb_snapshots;
|
||||
}
|
||||
|
||||
sn_tab = qemu_mallocz(s->nb_snapshots * sizeof(QEMUSnapshotInfo));
|
||||
for(i = 0; i < s->nb_snapshots; i++) {
|
||||
sn_info = sn_tab + i;
|
||||
sn = s->snapshots + i;
|
||||
pstrcpy(sn_info->id_str, sizeof(sn_info->id_str),
|
||||
sn->id_str);
|
||||
pstrcpy(sn_info->name, sizeof(sn_info->name),
|
||||
sn->name);
|
||||
sn_info->vm_state_size = sn->vm_state_size;
|
||||
sn_info->date_sec = sn->date_sec;
|
||||
sn_info->date_nsec = sn->date_nsec;
|
||||
sn_info->vm_clock_nsec = sn->vm_clock_nsec;
|
||||
}
|
||||
*psn_tab = sn_tab;
|
||||
return s->nb_snapshots;
|
||||
}
|
||||
|
||||
static int qcow_check(BlockDriverState *bs)
|
||||
{
|
||||
|
|
|
|||
|
|
@ -138,6 +138,13 @@ static inline int size_to_clusters(BDRVQcowState *s, int64_t size)
|
|||
return (size + (s->cluster_size - 1)) >> s->cluster_bits;
|
||||
}
|
||||
|
||||
static inline int64_t align_offset(int64_t offset, int n)
|
||||
{
|
||||
offset = (offset + n - 1) & ~(n - 1);
|
||||
return offset;
|
||||
}
|
||||
|
||||
|
||||
// FIXME Need qcow2_ prefix to global functions
|
||||
|
||||
/* qcow2.c functions */
|
||||
|
|
@ -184,4 +191,13 @@ uint64_t alloc_compressed_cluster_offset(BlockDriverState *bs,
|
|||
int alloc_cluster_link_l2(BlockDriverState *bs, uint64_t cluster_offset,
|
||||
QCowL2Meta *m);
|
||||
|
||||
/* qcow2-snapshot.c functions */
|
||||
int qcow_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info);
|
||||
int qcow_snapshot_goto(BlockDriverState *bs, const char *snapshot_id);
|
||||
int qcow_snapshot_delete(BlockDriverState *bs, const char *snapshot_id);
|
||||
int qcow_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab);
|
||||
|
||||
void qcow_free_snapshots(BlockDriverState *bs);
|
||||
int qcow_read_snapshots(BlockDriverState *bs);
|
||||
|
||||
#endif
|
||||
|
|
|
|||
Loading…
Reference in New Issue