diff options
Diffstat (limited to 'block/qcow2-cluster.c')
| -rw-r--r-- | block/qcow2-cluster.c | 25 |
1 files changed, 15 insertions, 10 deletions
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index a747a88..353889d 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -759,7 +759,7 @@ out: * restarted, but the whole request should not be failed. */ static int do_alloc_cluster_offset(BlockDriverState *bs, uint64_t guest_offset, - uint64_t *host_offset, unsigned int *nb_clusters, uint64_t *l2_table) + uint64_t *host_offset, unsigned int *nb_clusters) { BDRVQcowState *s = bs->opaque; int64_t cluster_offset; @@ -853,6 +853,7 @@ int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset, n_start, n_end); /* Find L2 entry for the first involved cluster */ +again: ret = get_cluster_table(bs, offset, &l2_table, &l2_index); if (ret < 0) { return ret; @@ -862,7 +863,6 @@ int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset, * Calculate the number of clusters to look for. We stop at L2 table * boundaries to keep things simple. */ -again: nb_clusters = MIN(size_to_clusters(s, n_end << BDRV_SECTOR_BITS), s->l2_size - l2_index); @@ -896,6 +896,18 @@ again: cluster_offset &= L2E_OFFSET_MASK; + /* + * The L2 table isn't used any more after this. As long as the cache works + * synchronously, it's important to release it before calling + * do_alloc_cluster_offset, which may yield if we need to wait for another + * request to complete. If we still had the reference, we could use up the + * whole cache with sleeping requests. + */ + ret = qcow2_cache_put(bs, s->l2_table_cache, (void**) &l2_table); + if (ret < 0) { + return ret; + } + /* If there is something left to allocate, do that now */ *m = (QCowL2Meta) { .cluster_offset = cluster_offset, @@ -919,7 +931,7 @@ again: /* Allocate, if necessary at a given offset in the image file */ ret = do_alloc_cluster_offset(bs, alloc_offset, &alloc_cluster_offset, - &nb_clusters, l2_table); + &nb_clusters); if (ret == -EAGAIN) { goto again; } else if (ret < 0) { @@ -947,11 +959,6 @@ again: } /* Some cleanup work */ - ret = qcow2_cache_put(bs, s->l2_table_cache, (void**) &l2_table); - if (ret < 0) { - goto fail_put; - } - sectors = (keep_clusters + nb_clusters) << (s->cluster_bits - 9); if (sectors > n_end) { sectors = n_end; @@ -963,8 +970,6 @@ again: return 0; fail: - qcow2_cache_put(bs, s->l2_table_cache, (void**) &l2_table); -fail_put: if (m->nb_clusters > 0) { QLIST_REMOVE(m, next_in_flight); } |