On 14.10.2013 23:52, Wenchao Xia wrote:
> The return value is only used for error report before this patch,
> so change the function protype to return void.
>
> Signed-off-by: Wenchao Xia <xiaw...@linux.vnet.ibm.com>
> ---
> block/qcow2-snapshot.c | 27 +++++++++++++++++++++++----
> block/qcow2.h | 4 +++-
> block/rbd.c | 21 ++++++++++++---------
> block/sheepdog.c | 29 ++++++++++++++++++++---------
> block/snapshot.c | 19 +++++++++++++------
> blockdev.c | 10 ++++------
> include/block/block_int.h | 5 +++--
> include/block/snapshot.h | 5 +++--
> qemu-img.c | 10 ++++++----
> savevm.c | 12 ++++++++----
> 10 files changed, 95 insertions(+), 47 deletions(-)
>
> diff --git a/block/qcow2-snapshot.c b/block/qcow2-snapshot.c
> index 3529c68..b373f9a 100644
> --- a/block/qcow2-snapshot.c
> +++ b/block/qcow2-snapshot.c
> @@ -347,7 +347,9 @@ static int find_snapshot_by_id_or_name(BlockDriverState
> *bs,
> }
>
> /* if no id is provided, a new one is constructed */
> -int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info)
> +void qcow2_snapshot_create(BlockDriverState *bs,
> + QEMUSnapshotInfo *sn_info,
> + Error **errp)
> {
> BDRVQcowState *s = bs->opaque;
> QCowSnapshot *new_snapshot_list = NULL;
> @@ -366,7 +368,8 @@ int qcow2_snapshot_create(BlockDriverState *bs,
> QEMUSnapshotInfo *sn_info)
>
> /* Check that the ID is unique */
> if (find_snapshot_by_id_and_name(bs, sn_info->id_str, NULL) >= 0) {
> - return -EEXIST;
> + error_setg(errp, "Snapshot with id %s already exist",
> sn_info->id_str);
> + return;
> }
>
> /* Populate sn with passed data */
> @@ -383,6 +386,9 @@ int qcow2_snapshot_create(BlockDriverState *bs,
> QEMUSnapshotInfo *sn_info)
> l1_table_offset = qcow2_alloc_clusters(bs, s->l1_size *
> sizeof(uint64_t));
> if (l1_table_offset < 0) {
> ret = l1_table_offset;
> + error_setg(errp,
> + "Failed in allocation of snapshot L1 table: %d (%s)",
> + ret, strerror(-ret));
You may want to use error_setg_errno instead (here and in many other
places in this patch).
> goto fail;
> }
>
> @@ -397,12 +403,20 @@ int qcow2_snapshot_create(BlockDriverState *bs,
> QEMUSnapshotInfo *sn_info)
> ret = qcow2_pre_write_overlap_check(bs, 0, sn->l1_table_offset,
> s->l1_size * sizeof(uint64_t));
> if (ret < 0) {
> + error_setg(errp, "Failed in overlap check for snapshot L1 table at %"
> + PRIu64 " with size %" PRIu64 ": %d (%s)",
> + sn->l1_table_offset, s->l1_size * sizeof(uint64_t),
> + ret, strerror(-ret));
s->l1_size * sizeof(uint64_t) is of the same type as uint64_t (PRIu64)
only on 64 bit systems. On 32 bit systems, it probably is the same as
uint32_t (because of a different size_t width).
> goto fail;
> }
>
> ret = bdrv_pwrite(bs->file, sn->l1_table_offset, l1_table,
> s->l1_size * sizeof(uint64_t));
> if (ret < 0) {
> + error_setg(errp, "Failed in update of snapshot L1 table at %"
> + PRIu64 " with size %" PRIu64 ": %d (%s)",
> + sn->l1_table_offset, s->l1_size * sizeof(uint64_t),
> + ret, strerror(-ret));
Same here.
> goto fail;
> }
>
> @@ -416,6 +430,9 @@ int qcow2_snapshot_create(BlockDriverState *bs,
> QEMUSnapshotInfo *sn_info)
> */
> ret = qcow2_update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size,
> 1);
> if (ret < 0) {
> + error_setg(errp, "Failed in update of refcount for snapshot at %"
> + PRIu64 " with size %d: %d (%s)",
> + s->l1_table_offset, s->l1_size, ret, strerror(-ret));
> goto fail;
> }
>
> @@ -431,6 +448,8 @@ int qcow2_snapshot_create(BlockDriverState *bs,
> QEMUSnapshotInfo *sn_info)
>
> ret = qcow2_write_snapshots(bs);
> if (ret < 0) {
> + /* Following line will be replaced with more detailed error later */
> + error_setg(errp, "Failed in write of snapshot");
> g_free(s->snapshots);
> s->snapshots = old_snapshot_list;
> s->nb_snapshots--;
> @@ -452,14 +471,14 @@ int qcow2_snapshot_create(BlockDriverState *bs,
> QEMUSnapshotInfo *sn_info)
> qcow2_check_refcounts(bs, &result, 0);
> }
> #endif
> - return 0;
> + return;
>
> fail:
> g_free(sn->id_str);
> g_free(sn->name);
> g_free(l1_table);
>
> - return ret;
> + return;
> }
>
> /* copy the snapshot 'snapshot_name' into the current disk image */
> diff --git a/block/qcow2.h b/block/qcow2.h
> index 922e190..c0a3d01 100644
> --- a/block/qcow2.h
> +++ b/block/qcow2.h
> @@ -481,7 +481,9 @@ int qcow2_zero_clusters(BlockDriverState *bs, uint64_t
> offset, int nb_sectors);
> int qcow2_expand_zero_clusters(BlockDriverState *bs);
>
> /* qcow2-snapshot.c functions */
> -int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info);
> +void qcow2_snapshot_create(BlockDriverState *bs,
> + QEMUSnapshotInfo *sn_info,
> + Error **errp);
> int qcow2_snapshot_goto(BlockDriverState *bs, const char *snapshot_id);
> int qcow2_snapshot_delete(BlockDriverState *bs,
> const char *snapshot_id,
> diff --git a/block/rbd.c b/block/rbd.c
> index 4a1ea5b..6181999 100644
> --- a/block/rbd.c
> +++ b/block/rbd.c
> @@ -860,14 +860,16 @@ static int qemu_rbd_truncate(BlockDriverState *bs,
> int64_t offset)
> return 0;
> }
>
> -static int qemu_rbd_snap_create(BlockDriverState *bs,
> - QEMUSnapshotInfo *sn_info)
> +static void qemu_rbd_snap_create(BlockDriverState *bs,
> + QEMUSnapshotInfo *sn_info,
> + Error **errp)
> {
> BDRVRBDState *s = bs->opaque;
> int r;
>
> if (sn_info->name[0] == '\0') {
> - return -EINVAL; /* we need a name for rbd snapshots */
> + error_setg(errp, "rbd snapshot need a valid name");
*needs (or "requires")
> + return; /* we need a name for rbd snapshots */
> }
>
> /*
> @@ -876,20 +878,21 @@ static int qemu_rbd_snap_create(BlockDriverState *bs,
> */
> if (sn_info->id_str[0] != '\0' &&
> strcmp(sn_info->id_str, sn_info->name) != 0) {
> - return -EINVAL;
> + error_setg(errp, "rbd snapshot id should be empty or equal to name");
> + return;
> }
>
> if (strlen(sn_info->name) >= sizeof(sn_info->id_str)) {
> - return -ERANGE;
> + error_setg(errp, "rbd snapshot name is too long");
> + return;
> }
>
> r = rbd_snap_create(s->image, sn_info->name);
> if (r < 0) {
> - error_report("failed to create snap: %s", strerror(-r));
> - return r;
> + error_setg(errp,
> + "Failed to create snapshot: %d (%s)",
> + r, strerror(-r));
> }
> -
> - return 0;
> }
>
> static int qemu_rbd_snap_remove(BlockDriverState *bs,
> diff --git a/block/sheepdog.c b/block/sheepdog.c
> index 5f81c93..67aaeb7 100644
> --- a/block/sheepdog.c
> +++ b/block/sheepdog.c
> @@ -1961,7 +1961,9 @@ static int coroutine_fn
> sd_co_flush_to_disk(BlockDriverState *bs)
> return acb->ret;
> }
>
> -static int sd_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo
> *sn_info)
> +static void sd_snapshot_create(BlockDriverState *bs,
> + QEMUSnapshotInfo *sn_info,
> + Error **errp)
> {
> BDRVSheepdogState *s = bs->opaque;
> int ret, fd;
> @@ -1974,10 +1976,10 @@ static int sd_snapshot_create(BlockDriverState *bs,
> QEMUSnapshotInfo *sn_info)
> s->name, sn_info->vm_state_size, s->is_snapshot);
>
> if (s->is_snapshot) {
> - error_report("You can't create a snapshot of a snapshot VDI, "
> - "%s (%" PRIu32 ").", s->name, s->inode.vdi_id);
> + error_setg(errp, "You can't create a snapshot of a snapshot VDI, "
> + "%s (%" PRIu32 ")", s->name, s->inode.vdi_id);
>
> - return -EINVAL;
> + return;
> }
>
> DPRINTF("%s %s\n", sn_info->name, sn_info->id_str);
> @@ -1995,21 +1997,27 @@ static int sd_snapshot_create(BlockDriverState *bs,
> QEMUSnapshotInfo *sn_info)
> fd = connect_to_sdog(s);
> if (fd < 0) {
> ret = fd;
> + error_setg(errp, "Failed to connect: %d (%s)", ret, strerror(-ret));
You may remove the "ret = fd" line before the error_setg(), if you want
to; but then you'd have to replace the ret in the error_setg() by fd (it
should be an error_setg_errno() again, anyway). Do as you please.
> goto cleanup;
> }
>
> ret = write_object(fd, (char *)&s->inode,
> vid_to_vdi_oid(s->inode.vdi_id),
> s->inode.nr_copies, datalen, 0, false,
> s->cache_flags);
> if (ret < 0) {
> - error_report("failed to write snapshot's inode.");
> + error_setg(errp,
> + "Failed to write snapshot's inode: %d (%s)",
> + ret, strerror(-ret));
> goto cleanup;
> }
>
> ret = do_sd_create(s, s->name, s->inode.vdi_size, s->inode.vdi_id,
> &new_vid,
> 1);
> if (ret < 0) {
> - error_report("failed to create inode for snapshot. %s",
> - strerror(errno));
> + error_setg(errp,
> + "Failed to create inode for snapshot: %d (%s), "
> + "errno %d (%s)",
> + ret, strerror(-ret),
> + errno, strerror(errno));
This and the following hunk are actually places, where error_setg()
seems better than error_setg_errno() (because it's unclear whether -ret
or errno contains the true error value).
Max
> goto cleanup;
> }
>
> @@ -2019,7 +2027,10 @@ static int sd_snapshot_create(BlockDriverState *bs,
> QEMUSnapshotInfo *sn_info)
> s->inode.nr_copies, datalen, 0, s->cache_flags);
>
> if (ret < 0) {
> - error_report("failed to read new inode info. %s", strerror(errno));
> + error_setg(errp, "Failed to read new inode info: %d (%s), "
> + "errno %d (%s)",
> + ret, strerror(-ret),
> + errno, strerror(errno));
> goto cleanup;
> }
>
> @@ -2029,7 +2040,7 @@ static int sd_snapshot_create(BlockDriverState *bs,
> QEMUSnapshotInfo *sn_info)
>
> cleanup:
> closesocket(fd);
> - return ret;
> + return;
> }
>
> /*
> diff --git a/block/snapshot.c b/block/snapshot.c
> index a05c0c0..3122e3c 100644
> --- a/block/snapshot.c
> +++ b/block/snapshot.c
> @@ -138,20 +138,27 @@ int bdrv_can_snapshot(BlockDriverState *bs)
> return 1;
> }
>
> -int bdrv_snapshot_create(BlockDriverState *bs,
> - QEMUSnapshotInfo *sn_info)
> +void bdrv_snapshot_create(BlockDriverState *bs,
> + QEMUSnapshotInfo *sn_info,
> + Error **errp)
> {
> BlockDriver *drv = bs->drv;
> if (!drv) {
> - return -ENOMEDIUM;
> + error_set(errp, QERR_DEVICE_HAS_NO_MEDIUM, bdrv_get_device_name(bs));
> + return;
> }
> if (drv->bdrv_snapshot_create) {
> - return drv->bdrv_snapshot_create(bs, sn_info);
> + drv->bdrv_snapshot_create(bs, sn_info, errp);
> + return;
> }
> if (bs->file) {
> - return bdrv_snapshot_create(bs->file, sn_info);
> + bdrv_snapshot_create(bs->file, sn_info, errp);
> + return;
> }
> - return -ENOTSUP;
> +
> + error_set(errp, QERR_BLOCK_FORMAT_FEATURE_NOT_SUPPORTED,
> + drv->format_name, bdrv_get_device_name(bs),
> + "internal snapshot creation");
> }
>
> int bdrv_snapshot_goto(BlockDriverState *bs,
> diff --git a/blockdev.c b/blockdev.c
> index 4f76e28..c4e7124 100644
> --- a/blockdev.c
> +++ b/blockdev.c
> @@ -1077,7 +1077,7 @@ static void
> internal_snapshot_prepare(BlkTransactionState *common,
> qemu_timeval tv;
> BlockdevSnapshotInternal *internal;
> InternalSnapshotState *state;
> - int ret1;
> + Error *local_err = NULL;
>
> g_assert(common->action->kind ==
> TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_INTERNAL_SYNC);
> @@ -1135,11 +1135,9 @@ static void
> internal_snapshot_prepare(BlkTransactionState *common,
> sn->date_nsec = tv.tv_usec * 1000;
> sn->vm_clock_nsec = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
>
> - ret1 = bdrv_snapshot_create(bs, sn);
> - if (ret1 < 0) {
> - error_setg_errno(errp, -ret1,
> - "Failed to create snapshot '%s' on device '%s'",
> - name, device);
> + bdrv_snapshot_create(bs, sn, &local_err);
> + if (error_is_set(&local_err)) {
> + error_propagate(errp, local_err);
> return;
> }
>
> diff --git a/include/block/block_int.h b/include/block/block_int.h
> index a48731d..553d843 100644
> --- a/include/block/block_int.h
> +++ b/include/block/block_int.h
> @@ -161,8 +161,9 @@ struct BlockDriver {
> int (*bdrv_write_compressed)(BlockDriverState *bs, int64_t sector_num,
> const uint8_t *buf, int nb_sectors);
>
> - int (*bdrv_snapshot_create)(BlockDriverState *bs,
> - QEMUSnapshotInfo *sn_info);
> + void (*bdrv_snapshot_create)(BlockDriverState *bs,
> + QEMUSnapshotInfo *sn_info,
> + Error **errp);
> int (*bdrv_snapshot_goto)(BlockDriverState *bs,
> const char *snapshot_id);
> int (*bdrv_snapshot_delete)(BlockDriverState *bs,
> diff --git a/include/block/snapshot.h b/include/block/snapshot.h
> index 012bf22..a998316 100644
> --- a/include/block/snapshot.h
> +++ b/include/block/snapshot.h
> @@ -47,8 +47,9 @@ bool bdrv_snapshot_find_by_id_and_name(BlockDriverState *bs,
> QEMUSnapshotInfo *sn_info,
> Error **errp);
> int bdrv_can_snapshot(BlockDriverState *bs);
> -int bdrv_snapshot_create(BlockDriverState *bs,
> - QEMUSnapshotInfo *sn_info);
> +void bdrv_snapshot_create(BlockDriverState *bs,
> + QEMUSnapshotInfo *sn_info,
> + Error **errp);
> int bdrv_snapshot_goto(BlockDriverState *bs,
> const char *snapshot_id);
> int bdrv_snapshot_delete(BlockDriverState *bs,
> diff --git a/qemu-img.c b/qemu-img.c
> index 926f0a0..aa8b46f 100644
> --- a/qemu-img.c
> +++ b/qemu-img.c
> @@ -2080,10 +2080,12 @@ static int img_snapshot(int argc, char **argv)
> sn.date_sec = tv.tv_sec;
> sn.date_nsec = tv.tv_usec * 1000;
>
> - ret = bdrv_snapshot_create(bs, &sn);
> - if (ret) {
> - error_report("Could not create snapshot '%s': %d (%s)",
> - snapshot_name, ret, strerror(-ret));
> + bdrv_snapshot_create(bs, &sn, &err);
> + if (error_is_set(&err)) {
> + error_report("Could not create snapshot '%s': %s",
> + snapshot_name, error_get_pretty(err));
> + error_free(err);
> + ret = 1;
> }
> break;
>
> diff --git a/savevm.c b/savevm.c
> index 2f631d4..617d6eb 100644
> --- a/savevm.c
> +++ b/savevm.c
> @@ -2366,6 +2366,7 @@ void do_savevm(Monitor *mon, const QDict *qdict)
> qemu_timeval tv;
> struct tm tm;
> const char *name = qdict_get_try_str(qdict, "name");
> + Error *err = NULL;
>
> /* Verify if there is a device that doesn't support snapshots and is
> writable */
> bs = NULL;
> @@ -2439,10 +2440,13 @@ void do_savevm(Monitor *mon, const QDict *qdict)
> if (bdrv_can_snapshot(bs1)) {
> /* Write VM state size only to the image that contains the state
> */
> sn->vm_state_size = (bs == bs1 ? vm_state_size : 0);
> - ret = bdrv_snapshot_create(bs1, sn);
> - if (ret < 0) {
> - monitor_printf(mon, "Error while creating snapshot on
> '%s'\n",
> - bdrv_get_device_name(bs1));
> + bdrv_snapshot_create(bs1, sn, &err);
> + if (error_is_set(&err)) {
> + monitor_printf(mon,
> + "Error while creating snapshot on '%s': %s\n",
> + bdrv_get_device_name(bs1),
> + error_get_pretty(err));
> + error_free(err);
> }
> }
> }
