| Message ID | 40ed71f2147221dc6c29b6603cb4a35db599d0fa.1593342067.git.berto@igalia.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add subcluster allocation to qcow2 | expand |
On 28.06.20 13:02, Alberto Garcia wrote: > Extended L2 entries are 128-bit wide: 64 bits for the entry itself and > 64 bits for the subcluster allocation bitmap. > > In order to support them correctly get/set_l2_entry() need to be > updated so they take the entry width into account in order to > calculate the correct offset. > > This patch also adds the get/set_l2_bitmap() functions that are > used to access the bitmaps. For convenience we allow calling > get_l2_bitmap() on images without subclusters. In this case the > returned value is always 0 and has no meaning. > > Signed-off-by: Alberto Garcia <berto@igalia.com> > Reviewed-by: Eric Blake <eblake@redhat.com> > --- > block/qcow2.h | 21 +++++++++++++++++++++ > 1 file changed, 21 insertions(+) Reviewed-by: Max Reitz <mreitz@redhat.com>
diff --git a/block/qcow2.h b/block/qcow2.h index 46b351229a..82b86f6cec 100644 --- a/block/qcow2.h +++ b/block/qcow2.h @@ -533,15 +533,36 @@ static inline size_t l2_entry_size(BDRVQcow2State *s) static inline uint64_t get_l2_entry(BDRVQcow2State *s, uint64_t *l2_slice, int idx) { + idx *= l2_entry_size(s) / sizeof(uint64_t); return be64_to_cpu(l2_slice[idx]); } +static inline uint64_t get_l2_bitmap(BDRVQcow2State *s, uint64_t *l2_slice, + int idx) +{ + if (has_subclusters(s)) { + idx *= l2_entry_size(s) / sizeof(uint64_t); + return be64_to_cpu(l2_slice[idx + 1]); + } else { + return 0; /* For convenience only; this value has no meaning. */ + } +} + static inline void set_l2_entry(BDRVQcow2State *s, uint64_t *l2_slice, int idx, uint64_t entry) { + idx *= l2_entry_size(s) / sizeof(uint64_t); l2_slice[idx] = cpu_to_be64(entry); } +static inline void set_l2_bitmap(BDRVQcow2State *s, uint64_t *l2_slice, + int idx, uint64_t bitmap) +{ + assert(has_subclusters(s)); + idx *= l2_entry_size(s) / sizeof(uint64_t); + l2_slice[idx + 1] = cpu_to_be64(bitmap); +} + static inline bool has_data_file(BlockDriverState *bs) { BDRVQcow2State *s = bs->opaque;