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[Qemu-devel] [PATCH 3/4] qcow2: Split out snapshot functions
|
From: |
Kevin Wolf |
|
Subject: |
[Qemu-devel] [PATCH 3/4] qcow2: Split out snapshot functions |
|
Date: |
Thu, 28 May 2009 16:07:06 +0200 |
qcow2-snapshot.c contains the code related to snapshotting.
Signed-off-by: Kevin Wolf <address@hidden>
---
Makefile | 1 +
block/qcow2-snapshot.c | 405 ++++++++++++++++++++++++++++++++++++++++++++++++
block/qcow2.c | 392 ----------------------------------------------
block/qcow2.h | 16 ++
4 files changed, 422 insertions(+), 392 deletions(-)
create mode 100644 block/qcow2-snapshot.c
diff --git a/Makefile b/Makefile
index 7bc37ce..32e2f68 100644
--- a/Makefile
+++ b/Makefile
@@ -69,6 +69,7 @@ BLOCK_OBJS=cutils.o cache-utils.o qemu-malloc.o qemu-option.o
module.o
BLOCK_OBJS+=block/cow.o block/qcow.o aes.o block/vmdk.o block/cloop.o
BLOCK_OBJS+=block/dmg.o block/bochs.o block/vpc.o block/vvfat.o
BLOCK_OBJS+=block/qcow2.o block/qcow2-refcount.o block/qcow2-cluster.o
+BLOCK_OBJS+=block/qcow2-snapshot.o
BLOCK_OBJS+=block/parallels.o block/nbd.o
BLOCK_OBJS+=nbd.o block.o aio.o
diff --git a/block/qcow2-snapshot.c b/block/qcow2-snapshot.c
new file mode 100644
index 0000000..2883e50
--- /dev/null
+++ b/block/qcow2-snapshot.c
@@ -0,0 +1,405 @@
+/*
+ * Block driver for the QCOW version 2 format
+ *
+ * Copyright (c) 2004-2006 Fabrice Bellard
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "qemu-common.h"
+#include "block_int.h"
+#include "block/qcow2.h"
+
+typedef struct __attribute__((packed)) QCowSnapshotHeader {
+ /* header is 8 byte aligned */
+ uint64_t l1_table_offset;
+
+ uint32_t l1_size;
+ uint16_t id_str_size;
+ uint16_t name_size;
+
+ uint32_t date_sec;
+ uint32_t date_nsec;
+
+ 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;
+
+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;
+}
+
+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 */
+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 */
+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;
+}
+
+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;
+}
+
+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;
+}
+
diff --git a/block/qcow2.c b/block/qcow2.c
index a91aaeb..febdf67 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -57,29 +57,6 @@ typedef struct {
#define QCOW_EXT_MAGIC_BACKING_FORMAT 0xE2792ACA
-typedef struct __attribute__((packed)) QCowSnapshotHeader {
- /* header is 8 byte aligned */
- uint64_t l1_table_offset;
-
- uint32_t l1_size;
- uint16_t id_str_size;
- uint16_t name_size;
-
- uint32_t date_sec;
- uint32_t date_nsec;
-
- 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)
{
diff --git a/block/qcow2.h b/block/qcow2.h
index 367d9bd..397f21d 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -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
--
1.6.0.6