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>

1 files changed, 0 insertions, 392 deletions

diff --git a/block/qcow2.c b/block/qcow2.c
index 9f8b937..aeaedb7 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)
 {