| Message ID | 20190606184159.979-6-jsnow@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | block/dirty-bitmap: check number and size constraints against queued bitmaps | expand |
On 6/6/19 1:41 PM, John Snow wrote: > Similarly to the previous commit, we need to also keep a ledger of the > additional directory size burden that we've not yet committed so we can > reject new additions sooner instead of later. > > Signed-off-by: John Snow <jsnow@redhat.com> > --- > block/qcow2.h | 1 + > block/qcow2-bitmap.c | 13 ++++++++++++- > 2 files changed, 13 insertions(+), 1 deletion(-) > > diff --git a/block/qcow2.h b/block/qcow2.h > index ebf60ac236..5aff97eb9c 100644 > --- a/block/qcow2.h > +++ b/block/qcow2.h > @@ -318,6 +318,7 @@ typedef struct BDRVQcow2State { > > uint32_t nb_bitmaps; > uint32_t nb_queued_bitmaps; > + uint32_t queued_directory_size; > uint64_t bitmap_directory_size; Why can we get away with uint32_t for the queue size, but uint64_t for the stored size? Something feels fishy.
On 6/6/19 10:30 PM, Eric Blake wrote: > On 6/6/19 1:41 PM, John Snow wrote: >> Similarly to the previous commit, we need to also keep a ledger of the >> additional directory size burden that we've not yet committed so we can >> reject new additions sooner instead of later. >> >> Signed-off-by: John Snow <jsnow@redhat.com> >> --- >> block/qcow2.h | 1 + >> block/qcow2-bitmap.c | 13 ++++++++++++- >> 2 files changed, 13 insertions(+), 1 deletion(-) >> >> diff --git a/block/qcow2.h b/block/qcow2.h >> index ebf60ac236..5aff97eb9c 100644 >> --- a/block/qcow2.h >> +++ b/block/qcow2.h >> @@ -318,6 +318,7 @@ typedef struct BDRVQcow2State { >> >> uint32_t nb_bitmaps; >> uint32_t nb_queued_bitmaps; >> + uint32_t queued_directory_size; >> uint64_t bitmap_directory_size; > > Why can we get away with uint32_t for the queue size, but uint64_t for > the stored size? Something feels fishy. > That would be me using the wrong type. --js
diff --git a/block/qcow2.h b/block/qcow2.h index ebf60ac236..5aff97eb9c 100644 --- a/block/qcow2.h +++ b/block/qcow2.h @@ -318,6 +318,7 @@ typedef struct BDRVQcow2State { uint32_t nb_bitmaps; uint32_t nb_queued_bitmaps; + uint32_t queued_directory_size; uint64_t bitmap_directory_size; uint64_t bitmap_directory_offset; diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c index 7193c66787..b103fab362 100644 --- a/block/qcow2-bitmap.c +++ b/block/qcow2-bitmap.c @@ -1405,16 +1405,23 @@ static Qcow2Bitmap *find_bitmap_by_name(Qcow2BitmapList *bm_list, static int qcow2_remove_queued_dirty_bitmap( BlockDriverState *bs, const char *name, Error **errp) { + uint32_t size_delta; BDRVQcow2State *s = bs->opaque; BdrvDirtyBitmap *bitmap = bdrv_find_dirty_bitmap(bs, name); + if (!bitmap) { error_setg(errp, "Node '%s' has no stored or enqueued bitmap '%s'", bdrv_get_node_name(bs), name); return -ENOENT; } + + size_delta = calc_dir_entry_size(strlen(name), 0); assert(s->nb_queued_bitmaps > 0); assert(bdrv_dirty_bitmap_get_persistence(bitmap)); + assert(s->queued_directory_size >= size_delta); + s->nb_queued_bitmaps -= 1; + s->queued_directory_size -= size_delta; return 0; } @@ -1561,6 +1568,7 @@ void qcow2_store_persistent_dirty_bitmaps(BlockDriverState *bs, Error **errp) goto fail; } s->nb_queued_bitmaps = 0; + s->queued_directory_size = 0; /* Bitmap directory was successfully updated, so, old data can be dropped. * TODO it is better to reuse these clusters */ @@ -1636,6 +1644,7 @@ int qcow2_add_persistent_dirty_bitmap(BlockDriverState *bs, const char *name = bdrv_dirty_bitmap_name(bitmap); uint32_t granularity = bdrv_dirty_bitmap_granularity(bitmap); uint32_t nb_bitmaps; + uint32_t size_delta; int ret = 0; if (s->qcow_version < 3) { @@ -1666,7 +1675,8 @@ int qcow2_add_persistent_dirty_bitmap(BlockDriverState *bs, goto fail; } - if (s->bitmap_directory_size + calc_dir_entry_size(strlen(name), 0) > + size_delta = calc_dir_entry_size(strlen(name), 0); + if (s->bitmap_directory_size + s->queued_directory_size + size_delta > QCOW2_MAX_BITMAP_DIRECTORY_SIZE) { error_setg(errp, "Not enough space in the bitmap directory"); @@ -1687,6 +1697,7 @@ int qcow2_add_persistent_dirty_bitmap(BlockDriverState *bs, } s->nb_queued_bitmaps += 1; + s->queued_directory_size += size_delta; return 0; fail:
Similarly to the previous commit, we need to also keep a ledger of the additional directory size burden that we've not yet committed so we can reject new additions sooner instead of later. Signed-off-by: John Snow <jsnow@redhat.com> --- block/qcow2.h | 1 + block/qcow2-bitmap.c | 13 ++++++++++++- 2 files changed, 13 insertions(+), 1 deletion(-)