On 04.11.2013 02:47, Wenchao Xia wrote: > δΊ 2013/11/2 20:39, Max Reitz ει: >> 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). >> > > I forgot we have error_setg_errno(), will use it. > >>> 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). > > I haven't a 32 bit system at hand to test, do you think > (int64_t)(s->l1_size * sizeof(uint64_t)) > could work for both 32 bit and 64 bit system?
Yes, that should work (although uint64_t would be more appropriate for PRIu64). > >> >>> 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") >> > > will change. > >>> + 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. >> > > The function is return void now, it seems "ret = fd" can be > removed, will do that. > >>> 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). >> > I guess change it as: > + error_setg(errp, > + "Failed to create inode for snapshot, return is %d", > + ret); > > ? No, I think you should leave the hunk as it is. Apparently we don't know whether the error value will be returned in ret or errno, so we need do display both. I was just commenting on that you should indeed leave this and the following hunk as they are and not replace them with error_setg_errno(), since they actually have to display two error values. Max > >> 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); >>> } >>> } >>> } >> >