diff options
| -rw-r--r-- | block-qcow2.c | 155 |
1 files changed, 92 insertions, 63 deletions
diff --git a/block-qcow2.c b/block-qcow2.c index 98c66f192d..c9d68af93f 100644 --- a/block-qcow2.c +++ b/block-qcow2.c @@ -856,6 +856,70 @@ static uint64_t alloc_compressed_cluster_offset(BlockDriverState *bs, return cluster_offset; } +typedef struct QCowL2Meta +{ + uint64_t offset; + int n_start; + int nb_available; + int nb_clusters; +} QCowL2Meta; + +static int alloc_cluster_link_l2(BlockDriverState *bs, uint64_t cluster_offset, + QCowL2Meta *m) +{ + BDRVQcowState *s = bs->opaque; + int i, j = 0, l2_index, ret; + uint64_t *old_cluster, start_sect, l2_offset, *l2_table; + + if (m->nb_clusters == 0) + return 0; + + if (!(old_cluster = qemu_malloc(m->nb_clusters * sizeof(uint64_t)))) + return -ENOMEM; + + /* copy content of unmodified sectors */ + start_sect = (m->offset & ~(s->cluster_size - 1)) >> 9; + if (m->n_start) { + ret = copy_sectors(bs, start_sect, cluster_offset, 0, m->n_start); + if (ret < 0) + goto err; + } + + if (m->nb_available & (s->cluster_sectors - 1)) { + uint64_t end = m->nb_available & ~(uint64_t)(s->cluster_sectors - 1); + ret = copy_sectors(bs, start_sect + end, cluster_offset + (end << 9), + m->nb_available - end, s->cluster_sectors); + if (ret < 0) + goto err; + } + + ret = -EIO; + /* update L2 table */ + if (!get_cluster_table(bs, m->offset, &l2_table, &l2_offset, &l2_index)) + goto err; + + for (i = 0; i < m->nb_clusters; i++) { + if(l2_table[l2_index + i] != 0) + old_cluster[j++] = l2_table[l2_index + i]; + + l2_table[l2_index + i] = cpu_to_be64((cluster_offset + + (i << s->cluster_bits)) | QCOW_OFLAG_COPIED); + } + + if (bdrv_pwrite(s->hd, l2_offset + l2_index * sizeof(uint64_t), + l2_table + l2_index, m->nb_clusters * sizeof(uint64_t)) != + m->nb_clusters * sizeof(uint64_t)) + goto err; + + for (i = 0; i < j; i++) + free_any_clusters(bs, old_cluster[i], 1); + + ret = 0; +err: + qemu_free(old_cluster); + return ret; + } + /* * alloc_cluster_offset * @@ -872,13 +936,12 @@ static uint64_t alloc_compressed_cluster_offset(BlockDriverState *bs, static uint64_t alloc_cluster_offset(BlockDriverState *bs, uint64_t offset, int n_start, int n_end, - int *num) + int *num, QCowL2Meta *m) { BDRVQcowState *s = bs->opaque; int l2_index, ret; uint64_t l2_offset, *l2_table, cluster_offset; - int nb_available, nb_clusters, i = 0; - uint64_t start_sect; + int nb_clusters, i = 0; ret = get_cluster_table(bs, offset, &l2_table, &l2_offset, &l2_index); if (ret == 0) @@ -886,8 +949,7 @@ static uint64_t alloc_cluster_offset(BlockDriverState *bs, nb_clusters = size_to_clusters(s, n_end << 9); - if (nb_clusters > s->l2_size - l2_index) - nb_clusters = s->l2_size - l2_index; + nb_clusters = MIN(nb_clusters, s->l2_size - l2_index); cluster_offset = be64_to_cpu(l2_table[l2_index]); @@ -897,11 +959,8 @@ static uint64_t alloc_cluster_offset(BlockDriverState *bs, nb_clusters = count_contiguous_clusters(nb_clusters, s->cluster_size, &l2_table[l2_index], 0); - nb_available = nb_clusters << (s->cluster_bits - 9); - if (nb_available > n_end) - nb_available = n_end; - cluster_offset &= ~QCOW_OFLAG_COPIED; + m->nb_clusters = 0; goto out; } @@ -914,7 +973,6 @@ static uint64_t alloc_cluster_offset(BlockDriverState *bs, /* how many available clusters ? */ while (i < nb_clusters) { - int j; i += count_contiguous_free_clusters(nb_clusters - i, &l2_table[l2_index + i]); @@ -924,14 +982,9 @@ static uint64_t alloc_cluster_offset(BlockDriverState *bs, (cluster_offset & QCOW_OFLAG_COMPRESSED)) break; - j = count_contiguous_clusters(nb_clusters - i, s->cluster_size, + i += count_contiguous_clusters(nb_clusters - i, s->cluster_size, &l2_table[l2_index + i], 0); - if (j) - free_any_clusters(bs, cluster_offset, j); - - i += j; - if(be64_to_cpu(l2_table[l2_index + i])) break; } @@ -941,48 +994,15 @@ static uint64_t alloc_cluster_offset(BlockDriverState *bs, cluster_offset = alloc_clusters(bs, nb_clusters * s->cluster_size); - /* we must initialize the cluster content which won't be - written */ - - nb_available = nb_clusters << (s->cluster_bits - 9); - if (nb_available > n_end) - nb_available = n_end; - - /* copy content of unmodified sectors */ - - start_sect = (offset & ~(s->cluster_size - 1)) >> 9; - if (n_start) { - ret = copy_sectors(bs, start_sect, cluster_offset, 0, n_start); - if (ret < 0) - return 0; - } - - if (nb_available & (s->cluster_sectors - 1)) { - uint64_t end = nb_available & ~(uint64_t)(s->cluster_sectors - 1); - ret = copy_sectors(bs, start_sect + end, - cluster_offset + (end << 9), - nb_available - end, - s->cluster_sectors); - if (ret < 0) - return 0; - } - - /* update L2 table */ - - for (i = 0; i < nb_clusters; i++) - l2_table[l2_index + i] = cpu_to_be64((cluster_offset + - (i << s->cluster_bits)) | - QCOW_OFLAG_COPIED); - - if (bdrv_pwrite(s->hd, - l2_offset + l2_index * sizeof(uint64_t), - l2_table + l2_index, - nb_clusters * sizeof(uint64_t)) != - nb_clusters * sizeof(uint64_t)) - return 0; + /* save info needed for meta data update */ + m->offset = offset; + m->n_start = n_start; + m->nb_clusters = nb_clusters; out: - *num = nb_available - n_start; + m->nb_available = MIN(nb_clusters << (s->cluster_bits - 9), n_end); + + *num = m->nb_available - n_start; return cluster_offset; } @@ -1113,6 +1133,7 @@ static int qcow_write(BlockDriverState *bs, int64_t sector_num, int ret, index_in_cluster, n; uint64_t cluster_offset; int n_end; + QCowL2Meta l2meta; while (nb_sectors > 0) { index_in_cluster = sector_num & (s->cluster_sectors - 1); @@ -1122,7 +1143,7 @@ static int qcow_write(BlockDriverState *bs, int64_t sector_num, n_end = QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors; cluster_offset = alloc_cluster_offset(bs, sector_num << 9, index_in_cluster, - n_end, &n); + n_end, &n, &l2meta); if (!cluster_offset) return -1; if (s->crypt_method) { @@ -1133,8 +1154,10 @@ static int qcow_write(BlockDriverState *bs, int64_t sector_num, } else { ret = bdrv_pwrite(s->hd, cluster_offset + index_in_cluster * 512, buf, n * 512); } - if (ret != n * 512) + if (ret != n * 512 || alloc_cluster_link_l2(bs, cluster_offset, &l2meta) < 0) { + free_any_clusters(bs, cluster_offset, l2meta.nb_clusters); return -1; + } nb_sectors -= n; sector_num += n; buf += n * 512; @@ -1153,6 +1176,7 @@ typedef struct QCowAIOCB { uint8_t *cluster_data; BlockDriverAIOCB *hd_aiocb; QEMUBH *bh; + QCowL2Meta l2meta; } QCowAIOCB; static void qcow_aio_read_cb(void *opaque, int ret); @@ -1281,6 +1305,7 @@ static QCowAIOCB *qcow_aio_setup(BlockDriverState *bs, acb->nb_sectors = nb_sectors; acb->n = 0; acb->cluster_offset = 0; + acb->l2meta.nb_clusters = 0; return acb; } @@ -1304,7 +1329,6 @@ static void qcow_aio_write_cb(void *opaque, int ret) BlockDriverState *bs = acb->common.bs; BDRVQcowState *s = bs->opaque; int index_in_cluster; - uint64_t cluster_offset; const uint8_t *src_buf; int n_end; @@ -1317,6 +1341,11 @@ static void qcow_aio_write_cb(void *opaque, int ret) return; } + if (alloc_cluster_link_l2(bs, acb->cluster_offset, &acb->l2meta) < 0) { + free_any_clusters(bs, acb->cluster_offset, acb->l2meta.nb_clusters); + goto fail; + } + acb->nb_sectors -= acb->n; acb->sector_num += acb->n; acb->buf += acb->n * 512; @@ -1334,10 +1363,10 @@ 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; - cluster_offset = alloc_cluster_offset(bs, acb->sector_num << 9, + acb->cluster_offset = alloc_cluster_offset(bs, acb->sector_num << 9, index_in_cluster, - n_end, &acb->n); - if (!cluster_offset || (cluster_offset & 511) != 0) { + n_end, &acb->n, &acb->l2meta); + if (!acb->cluster_offset || (acb->cluster_offset & 511) != 0) { ret = -EIO; goto fail; } @@ -1357,7 +1386,7 @@ static void qcow_aio_write_cb(void *opaque, int ret) src_buf = acb->buf; } acb->hd_aiocb = bdrv_aio_write(s->hd, - (cluster_offset >> 9) + index_in_cluster, + (acb->cluster_offset >> 9) + index_in_cluster, src_buf, acb->n, qcow_aio_write_cb, acb); if (acb->hd_aiocb == NULL) |