| Message ID | 1358996283-32441-5-git-send-email-xiawenc@linux.vnet.ibm.com |
|---|---|
| State | New |
| Headers | show |
Am 24.01.2013 03:57, schrieb Wenchao Xia: > This patch add function bdrv_query_snapshot_infolist(), which will > return snapshot info of an image in qmp object format. The implementation > code are mostly copied from qemu-img.c with modification to fit more > for qmp based block layer API. > To help filter out snapshot info not needed, a call back function is > added in bdrv_query_snapshot_infolist(). > bdrv_can_read_snapshot() should be called before call this function, > to avoid got *errp set unexpectedly. > > Signed-off-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com> > Reviewed-by: Eric Blake <eblake@redhat.com> > --- > block.c | 60 +++++++++++++++++++++++++++++++++++++++++++++++++ > include/block/block.h | 7 +++++ > 2 files changed, 67 insertions(+), 0 deletions(-) > > diff --git a/block.c b/block.c > index 934bb3f..7cdb6c6 100644 > --- a/block.c > +++ b/block.c > @@ -2842,6 +2842,66 @@ int coroutine_fn bdrv_co_is_allocated_above(BlockDriverState *top, > return 0; > } > > +SnapshotInfoList *bdrv_query_snapshot_infolist(BlockDriverState *bs, > + SnapshotFilterFunc filter, This filter things looks overengineered to me, and no patch in this series really uses it. Do we really need it? > + void *opaque, > + Error **errp) > +{ > + int i, sn_count; > + QEMUSnapshotInfo *sn_tab = NULL; > + SnapshotInfoList *info_list, *cur_item = NULL, *head = NULL; > + > + sn_count = bdrv_snapshot_list(bs, &sn_tab); > + if (sn_count < 0) { > + /* Now bdrv_snapshot_list() use negative value to tip error, so a check > + * of it was done here. In future errp can be set by that function > + * itself, by changing the call back functions in c files in ./block. > + */ > + const char *dev = bdrv_get_device_name(bs); > + if (sn_count == -ENOMEDIUM) { > + error_setg(errp, "Device '%s' is not inserted.", dev); > + } else if (sn_count == -ENOTSUP) { > + error_setg(errp, > + "Device '%s' does not support internal snapshot.", > + dev); > + } else { > + error_setg(errp, > + "Device '%s' got %d for bdrv_snapshot_list().", > + dev, sn_count); strerror(-sn_count) would make the error message more useful. You could also consider using switch instead of an if/else if chain. > + } > + return NULL; > + } > + > + for (i = 0; i < sn_count; i++) { > + if (filter && filter(&sn_tab[i], opaque) != 0) { > + continue; > + } > + > + info_list = g_new0(SnapshotInfoList, 1); > + > + info_list->value = g_new0(SnapshotInfo, 1); > + info_list->value->id = g_strdup(sn_tab[i].id_str); > + info_list->value->name = g_strdup(sn_tab[i].name); > + info_list->value->vm_state_size = sn_tab[i].vm_state_size; > + info_list->value->date_sec = sn_tab[i].date_sec; > + info_list->value->date_nsec = sn_tab[i].date_nsec; > + info_list->value->vm_clock_sec = sn_tab[i].vm_clock_nsec / 1000000000; > + info_list->value->vm_clock_nsec = sn_tab[i].vm_clock_nsec % 1000000000; Did I already mention somewhere that I'm a fan of compound literals? Looks so much nicer than repeating info_list->value-> in each line. ;-) Kevin
δΊ 2013-1-29 20:48, Kevin Wolf ει: > Am 24.01.2013 03:57, schrieb Wenchao Xia: >> This patch add function bdrv_query_snapshot_infolist(), which will >> return snapshot info of an image in qmp object format. The implementation >> code are mostly copied from qemu-img.c with modification to fit more >> for qmp based block layer API. >> To help filter out snapshot info not needed, a call back function is >> added in bdrv_query_snapshot_infolist(). >> bdrv_can_read_snapshot() should be called before call this function, >> to avoid got *errp set unexpectedly. >> >> Signed-off-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com> >> Reviewed-by: Eric Blake <eblake@redhat.com> >> --- >> block.c | 60 +++++++++++++++++++++++++++++++++++++++++++++++++ >> include/block/block.h | 7 +++++ >> 2 files changed, 67 insertions(+), 0 deletions(-) >> >> diff --git a/block.c b/block.c >> index 934bb3f..7cdb6c6 100644 >> --- a/block.c >> +++ b/block.c >> @@ -2842,6 +2842,66 @@ int coroutine_fn bdrv_co_is_allocated_above(BlockDriverState *top, >> return 0; >> } >> >> +SnapshotInfoList *bdrv_query_snapshot_infolist(BlockDriverState *bs, >> + SnapshotFilterFunc filter, > > This filter things looks overengineered to me, and no patch in this > series really uses it. Do we really need it? > > It is used later, which filter out the internal ones not exist in every block device. I think this provide a clearer way, than original code in savevm.c which use two "for" to get the correct snapshots. >> + void *opaque, >> + Error **errp) >> +{ >> + int i, sn_count; >> + QEMUSnapshotInfo *sn_tab = NULL; >> + SnapshotInfoList *info_list, *cur_item = NULL, *head = NULL; >> + >> + sn_count = bdrv_snapshot_list(bs, &sn_tab); >> + if (sn_count < 0) { >> + /* Now bdrv_snapshot_list() use negative value to tip error, so a check >> + * of it was done here. In future errp can be set by that function >> + * itself, by changing the call back functions in c files in ./block. >> + */ >> + const char *dev = bdrv_get_device_name(bs); >> + if (sn_count == -ENOMEDIUM) { >> + error_setg(errp, "Device '%s' is not inserted.", dev); >> + } else if (sn_count == -ENOTSUP) { >> + error_setg(errp, >> + "Device '%s' does not support internal snapshot.", >> + dev); >> + } else { >> + error_setg(errp, >> + "Device '%s' got %d for bdrv_snapshot_list().", >> + dev, sn_count); > > strerror(-sn_count) would make the error message more useful. > > You could also consider using switch instead of an if/else if chain. > OK. >> + } >> + return NULL; >> + } >> + >> + for (i = 0; i < sn_count; i++) { >> + if (filter && filter(&sn_tab[i], opaque) != 0) { >> + continue; >> + } >> + >> + info_list = g_new0(SnapshotInfoList, 1); >> + >> + info_list->value = g_new0(SnapshotInfo, 1); >> + info_list->value->id = g_strdup(sn_tab[i].id_str); >> + info_list->value->name = g_strdup(sn_tab[i].name); >> + info_list->value->vm_state_size = sn_tab[i].vm_state_size; >> + info_list->value->date_sec = sn_tab[i].date_sec; >> + info_list->value->date_nsec = sn_tab[i].date_nsec; >> + info_list->value->vm_clock_sec = sn_tab[i].vm_clock_nsec / 1000000000; >> + info_list->value->vm_clock_nsec = sn_tab[i].vm_clock_nsec % 1000000000; > > Did I already mention somewhere that I'm a fan of compound literals? > Looks so much nicer than repeating info_list->value-> in each line. ;-) > Do you mean value=info_list->value and then value->***=***? > Kevin >
diff --git a/block.c b/block.c index 934bb3f..7cdb6c6 100644 --- a/block.c +++ b/block.c @@ -2842,6 +2842,66 @@ int coroutine_fn bdrv_co_is_allocated_above(BlockDriverState *top, return 0; } +SnapshotInfoList *bdrv_query_snapshot_infolist(BlockDriverState *bs, + SnapshotFilterFunc filter, + void *opaque, + Error **errp) +{ + int i, sn_count; + QEMUSnapshotInfo *sn_tab = NULL; + SnapshotInfoList *info_list, *cur_item = NULL, *head = NULL; + + sn_count = bdrv_snapshot_list(bs, &sn_tab); + if (sn_count < 0) { + /* Now bdrv_snapshot_list() use negative value to tip error, so a check + * of it was done here. In future errp can be set by that function + * itself, by changing the call back functions in c files in ./block. + */ + const char *dev = bdrv_get_device_name(bs); + if (sn_count == -ENOMEDIUM) { + error_setg(errp, "Device '%s' is not inserted.", dev); + } else if (sn_count == -ENOTSUP) { + error_setg(errp, + "Device '%s' does not support internal snapshot.", + dev); + } else { + error_setg(errp, + "Device '%s' got %d for bdrv_snapshot_list().", + dev, sn_count); + } + return NULL; + } + + for (i = 0; i < sn_count; i++) { + if (filter && filter(&sn_tab[i], opaque) != 0) { + continue; + } + + info_list = g_new0(SnapshotInfoList, 1); + + info_list->value = g_new0(SnapshotInfo, 1); + info_list->value->id = g_strdup(sn_tab[i].id_str); + info_list->value->name = g_strdup(sn_tab[i].name); + info_list->value->vm_state_size = sn_tab[i].vm_state_size; + info_list->value->date_sec = sn_tab[i].date_sec; + info_list->value->date_nsec = sn_tab[i].date_nsec; + info_list->value->vm_clock_sec = sn_tab[i].vm_clock_nsec / 1000000000; + info_list->value->vm_clock_nsec = sn_tab[i].vm_clock_nsec % 1000000000; + + /* XXX: waiting for the qapi to support qemu-queue.h types */ + if (!cur_item) { + head = cur_item = info_list; + } else { + cur_item->next = info_list; + cur_item = info_list; + } + + } + + g_free(sn_tab); + return head; +} + BlockInfo *bdrv_query_info(BlockDriverState *bs) { BlockInfo *info = g_malloc0(sizeof(*info)); diff --git a/include/block/block.h b/include/block/block.h index b4c1612..ce18d4b 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -316,6 +316,13 @@ void bdrv_get_backing_filename(BlockDriverState *bs, char *filename, int filename_size); void bdrv_get_full_backing_filename(BlockDriverState *bs, char *dest, size_t sz); + +typedef int (*SnapshotFilterFunc)(const QEMUSnapshotInfo *sn, void *opaque); +/* assume bs is already opened, use qapi_free_* to free returned value. */ +SnapshotInfoList *bdrv_query_snapshot_infolist(BlockDriverState *bs, + SnapshotFilterFunc filter, + void *opaque, + Error **errp); BlockInfo *bdrv_query_info(BlockDriverState *s); BlockStats *bdrv_query_stats(const BlockDriverState *bs); int bdrv_can_read_snapshot(BlockDriverState *bs);