diff options
| author | Max Reitz <mreitz@redhat.com> | 2014-10-22 14:09:28 +0200 |
|---|---|---|
| committer | Kevin Wolf <kwolf@redhat.com> | 2014-10-23 15:34:01 +0200 |
| commit | 1d13d654666a7fd6d6a85a0ce9285dbf0d0444c2 (patch) | |
| tree | afc4fe0f17cb9f8c441ebebdc9597cdb7c6dc1bb | |
| parent | 9ebd84480583bb6d9a7666c079d99ff3266c423d (diff) | |
qcow2: Calculate refcount block entry count
The size of a refblock entry is (in theory) variable; calculate
therefore the number of entries per refblock and the according bit shift
(1 << x == entry count) when opening an image.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
| -rw-r--r-- | block/qcow2.c | 3 | ||||
| -rw-r--r-- | block/qcow2.h | 2 |
2 files changed, 5 insertions, 0 deletions
diff --git a/block/qcow2.c b/block/qcow2.c index 156a219993..3c8b88198b 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -698,6 +698,9 @@ static int qcow2_open(BlockDriverState *bs, QDict *options, int flags, s->l2_bits = s->cluster_bits - 3; /* L2 is always one cluster */ s->l2_size = 1 << s->l2_bits; + /* 2^(s->refcount_order - 3) is the refcount width in bytes */ + s->refcount_block_bits = s->cluster_bits - (s->refcount_order - 3); + s->refcount_block_size = 1 << s->refcount_block_bits; bs->total_sectors = header.size / 512; s->csize_shift = (62 - (s->cluster_bits - 8)); s->csize_mask = (1 << (s->cluster_bits - 8)) - 1; diff --git a/block/qcow2.h b/block/qcow2.h index 7d61e615ff..47cd4b3f76 100644 --- a/block/qcow2.h +++ b/block/qcow2.h @@ -223,6 +223,8 @@ typedef struct BDRVQcowState { int l2_size; int l1_size; int l1_vm_state_index; + int refcount_block_bits; + int refcount_block_size; int csize_shift; int csize_mask; uint64_t cluster_offset_mask; |