diff options
| -rw-r--r-- | block/qcow2-cluster.c | 28 | ||||
| -rw-r--r-- | block/qcow2.c | 36 | ||||
| -rw-r--r-- | block/qcow2.h | 4 |
3 files changed, 39 insertions, 29 deletions
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index dec0af673f..d23d5b3aff 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -611,12 +611,12 @@ static int write_l2_entries(BDRVQcowState *s, uint64_t *l2_table, return 0; } -int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, uint64_t cluster_offset, - QCowL2Meta *m) +int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m) { BDRVQcowState *s = bs->opaque; int i, j = 0, l2_index, ret; uint64_t *old_cluster, start_sect, l2_offset, *l2_table; + uint64_t cluster_offset = m->cluster_offset; if (m->nb_clusters == 0) return 0; @@ -677,16 +677,22 @@ err: /* * alloc_cluster_offset * - * For a given offset of the disk image, return cluster offset in - * qcow2 file. - * + * For a given offset of the disk image, return cluster offset in qcow2 file. * If the offset is not found, allocate a new cluster. * - * Return the cluster offset if successful, - * Return 0, otherwise. + * If the cluster was already allocated, m->nb_clusters is set to 0, + * m->depends_on is set to NULL and the other fields in m are meaningless. + * + * If the cluster is newly allocated, m->nb_clusters is set to the number of + * contiguous clusters that have been allocated. This may be 0 if the request + * conflict with another write request in flight; in this case, m->depends_on + * is set and the remaining fields of m are meaningless. * + * If m->nb_clusters is non-zero, the other fields of m are valid and contain + * information about the first allocated cluster. + * + * Return 0 on success and -errno in error cases */ - uint64_t qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset, int n_start, int n_end, @@ -700,7 +706,7 @@ uint64_t qcow2_alloc_cluster_offset(BlockDriverState *bs, ret = get_cluster_table(bs, offset, &l2_table, &l2_offset, &l2_index); if (ret < 0) { - return 0; + return ret; } nb_clusters = size_to_clusters(s, n_end << 9); @@ -717,6 +723,7 @@ uint64_t qcow2_alloc_cluster_offset(BlockDriverState *bs, cluster_offset &= ~QCOW_OFLAG_COPIED; m->nb_clusters = 0; + m->depends_on = NULL; goto out; } @@ -795,10 +802,11 @@ uint64_t qcow2_alloc_cluster_offset(BlockDriverState *bs, out: m->nb_available = MIN(nb_clusters << (s->cluster_bits - 9), n_end); + m->cluster_offset = cluster_offset; *num = m->nb_available - n_start; - return cluster_offset; + return 0; } static int decompress_buffer(uint8_t *out_buf, int out_buf_size, diff --git a/block/qcow2.c b/block/qcow2.c index e06f4dd3c1..773d381870 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -561,7 +561,7 @@ static void qcow_aio_write_cb(void *opaque, int ret) acb->hd_aiocb = NULL; if (ret >= 0) { - ret = qcow2_alloc_cluster_link_l2(bs, acb->cluster_offset, &acb->l2meta); + ret = qcow2_alloc_cluster_link_l2(bs, &acb->l2meta); } run_dependent_requests(&acb->l2meta); @@ -585,21 +585,23 @@ static void qcow_aio_write_cb(void *opaque, int ret) n_end > QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors) n_end = QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors; - acb->cluster_offset = qcow2_alloc_cluster_offset(bs, acb->sector_num << 9, - index_in_cluster, - n_end, &acb->n, &acb->l2meta); + ret = qcow2_alloc_cluster_offset(bs, acb->sector_num << 9, + index_in_cluster, n_end, &acb->n, &acb->l2meta); + if (ret < 0) { + goto done; + } + + acb->cluster_offset = acb->l2meta.cluster_offset; /* Need to wait for another request? If so, we are done for now. */ - if (!acb->cluster_offset && acb->l2meta.depends_on != NULL) { + if (acb->l2meta.nb_clusters == 0 && acb->l2meta.depends_on != NULL) { QLIST_INSERT_HEAD(&acb->l2meta.depends_on->dependent_requests, acb, next_depend); return; } - if (!acb->cluster_offset || (acb->cluster_offset & 511) != 0) { - ret = -EIO; - goto done; - } + assert((acb->cluster_offset & 511) == 0); + if (s->crypt_method) { if (!acb->cluster_data) { acb->cluster_data = qemu_mallocz(QCOW_MAX_CRYPT_CLUSTERS * @@ -782,27 +784,27 @@ static int get_bits_from_size(size_t size) static int preallocate(BlockDriverState *bs) { BDRVQcowState *s = bs->opaque; - uint64_t cluster_offset = 0; uint64_t nb_sectors; uint64_t offset; int num; + int ret; QCowL2Meta meta; nb_sectors = bdrv_getlength(bs) >> 9; offset = 0; QLIST_INIT(&meta.dependent_requests); + meta.cluster_offset = 0; while (nb_sectors) { num = MIN(nb_sectors, INT_MAX >> 9); - cluster_offset = qcow2_alloc_cluster_offset(bs, offset, 0, num, &num, - &meta); + ret = qcow2_alloc_cluster_offset(bs, offset, 0, num, &num, &meta); - if (cluster_offset == 0) { + if (ret < 0) { return -1; } - if (qcow2_alloc_cluster_link_l2(bs, cluster_offset, &meta) < 0) { - qcow2_free_any_clusters(bs, cluster_offset, meta.nb_clusters); + if (qcow2_alloc_cluster_link_l2(bs, &meta) < 0) { + qcow2_free_any_clusters(bs, meta.cluster_offset, meta.nb_clusters); return -1; } @@ -821,10 +823,10 @@ static int preallocate(BlockDriverState *bs) * all of the allocated clusters (otherwise we get failing reads after * EOF). Extend the image to the last allocated sector. */ - if (cluster_offset != 0) { + if (meta.cluster_offset != 0) { uint8_t buf[512]; memset(buf, 0, 512); - bdrv_write(s->hd, (cluster_offset >> 9) + num - 1, buf, 1); + bdrv_write(s->hd, (meta.cluster_offset >> 9) + num - 1, buf, 1); } return 0; diff --git a/block/qcow2.h b/block/qcow2.h index 26ab5d9523..d9ea6abc50 100644 --- a/block/qcow2.h +++ b/block/qcow2.h @@ -135,6 +135,7 @@ struct QCowAIOCB; typedef struct QCowL2Meta { uint64_t offset; + uint64_t cluster_offset; int n_start; int nb_available; int nb_clusters; @@ -199,8 +200,7 @@ uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs, uint64_t offset, int compressed_size); -int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, uint64_t cluster_offset, - QCowL2Meta *m); +int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m); /* qcow2-snapshot.c functions */ int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info); |