int len, i, shift, ret;
QCowHeader header;
+ /* Performance is terrible right now with cache=writethrough due mainly
+ * to reference count updates. If the user does not explicitly specify
+ * a caching type, force to writeback caching.
+ */
+ if ((flags & BDRV_O_CACHE_DEF)) {
+ flags |= BDRV_O_CACHE_WB;
+ flags &= ~BDRV_O_CACHE_DEF;
+ }
ret = bdrv_file_open(&s->hd, filename, flags);
if (ret < 0)
return ret;
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
*
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)
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]);
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;
}
/* how many available clusters ? */
while (i < nb_clusters) {
- int j;
i += count_contiguous_free_clusters(nb_clusters - i,
&l2_table[l2_index + i]);
(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;
}
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;
}
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);
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) {
} 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;
uint8_t *cluster_data;
BlockDriverAIOCB *hd_aiocb;
QEMUBH *bh;
+ QCowL2Meta l2meta;
} QCowAIOCB;
static void qcow_aio_read_cb(void *opaque, int ret);
acb->nb_sectors = nb_sectors;
acb->n = 0;
acb->cluster_offset = 0;
+ acb->l2meta.nb_clusters = 0;
return acb;
}
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;
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;
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;
}
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)
projects / qemu.git / blobdiff