diff options
| -rw-r--r-- | block/qcow2-refcount.c | 24 | ||||
| -rw-r--r-- | block/qcow2.c | 1 | ||||
| -rw-r--r-- | block/qcow2.h | 1 |
3 files changed, 25 insertions, 1 deletions
diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c index cbfb3fe..3dbde18 100644 --- a/block/qcow2-refcount.c +++ b/block/qcow2-refcount.c @@ -83,6 +83,16 @@ static Qcow2SetRefcountFunc *const set_refcount_funcs[] = { /*********************************************************/ /* refcount handling */ +static void update_max_refcount_table_index(BDRVQcow2State *s) +{ + unsigned i = s->refcount_table_size - 1; + while (i > 0 && (s->refcount_table[i] & REFT_OFFSET_MASK) == 0) { + i--; + } + /* Set s->max_refcount_table_index to the index of the last used entry */ + s->max_refcount_table_index = i; +} + int qcow2_refcount_init(BlockDriverState *bs) { BDRVQcow2State *s = bs->opaque; @@ -111,6 +121,7 @@ int qcow2_refcount_init(BlockDriverState *bs) } for(i = 0; i < s->refcount_table_size; i++) be64_to_cpus(&s->refcount_table[i]); + update_max_refcount_table_index(s); } return 0; fail: @@ -439,6 +450,10 @@ static int alloc_refcount_block(BlockDriverState *bs, } s->refcount_table[refcount_table_index] = new_block; + /* If there's a hole in s->refcount_table then it can happen + * that refcount_table_index < s->max_refcount_table_index */ + s->max_refcount_table_index = + MAX(s->max_refcount_table_index, refcount_table_index); /* The new refcount block may be where the caller intended to put its * data, so let it restart the search. */ @@ -580,6 +595,7 @@ static int alloc_refcount_block(BlockDriverState *bs, s->refcount_table = new_table; s->refcount_table_size = table_size; s->refcount_table_offset = table_offset; + update_max_refcount_table_index(s); /* Free old table. */ qcow2_free_clusters(bs, old_table_offset, old_table_size * sizeof(uint64_t), @@ -2171,6 +2187,7 @@ write_refblocks: s->refcount_table = on_disk_reftable; s->refcount_table_offset = reftable_offset; s->refcount_table_size = reftable_size; + update_max_refcount_table_index(s); return 0; @@ -2383,7 +2400,11 @@ int qcow2_check_metadata_overlap(BlockDriverState *bs, int ign, int64_t offset, } if ((chk & QCOW2_OL_REFCOUNT_BLOCK) && s->refcount_table) { - for (i = 0; i < s->refcount_table_size; i++) { + unsigned last_entry = s->max_refcount_table_index; + assert(last_entry < s->refcount_table_size); + assert(last_entry + 1 == s->refcount_table_size || + (s->refcount_table[last_entry + 1] & REFT_OFFSET_MASK) == 0); + for (i = 0; i <= last_entry; i++) { if ((s->refcount_table[i] & REFT_OFFSET_MASK) && overlaps_with(s->refcount_table[i] & REFT_OFFSET_MASK, s->cluster_size)) { @@ -2871,6 +2892,7 @@ int qcow2_change_refcount_order(BlockDriverState *bs, int refcount_order, /* Now update the rest of the in-memory information */ old_reftable = s->refcount_table; s->refcount_table = new_reftable; + update_max_refcount_table_index(s); s->refcount_bits = 1 << refcount_order; s->refcount_max = UINT64_C(1) << (s->refcount_bits - 1); diff --git a/block/qcow2.c b/block/qcow2.c index 96fb8a8..3e274bd 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -2743,6 +2743,7 @@ static int make_completely_empty(BlockDriverState *bs) s->refcount_table_offset = s->cluster_size; s->refcount_table_size = s->cluster_size / sizeof(uint64_t); + s->max_refcount_table_index = 0; g_free(s->refcount_table); s->refcount_table = new_reftable; diff --git a/block/qcow2.h b/block/qcow2.h index 1823414..f8aeb08 100644 --- a/block/qcow2.h +++ b/block/qcow2.h @@ -251,6 +251,7 @@ typedef struct BDRVQcow2State { uint64_t *refcount_table; uint64_t refcount_table_offset; uint32_t refcount_table_size; + uint32_t max_refcount_table_index; /* Last used entry in refcount_table */ uint64_t free_cluster_index; uint64_t free_byte_offset; |