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qcow2: Employ metadata overlap checks

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The pre-write overlap check function is now called before most of the
qcow2 writes (aborting it on collision or other error).

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Max Reitz 2013-08-30 14:34:26 +02:00 • committed by Kevin Wolf
parent a40f1c2add
commit cf93980e77
4 changed files with 86 additions and 0 deletions
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21
block/qcow2-cluster.c
View file

@ -80,6 +80,14 @@ int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t min_size,
goto fail;
}
/* the L1 position has not yet been updated, so these clusters must
* indeed be completely free */
ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_DEFAULT,
new_l1_table_offset, new_l1_size2);
if (ret < 0) {
goto fail;
}
BLKDBG_EVENT(bs->file, BLKDBG_L1_GROW_WRITE_TABLE);
for(i = 0; i < s->l1_size; i++)
new_l1_table[i] = cpu_to_be64(new_l1_table[i]);
@ -149,6 +157,13 @@ static int write_l1_entry(BlockDriverState *bs, int l1_index)
buf[i] = cpu_to_be64(s->l1_table[l1_start_index + i]);
}
ret = qcow2_pre_write_overlap_check(bs,
QCOW2_OL_DEFAULT & ~QCOW2_OL_ACTIVE_L1,
s->l1_table_offset + 8 * l1_start_index, sizeof(buf));
if (ret < 0) {
return ret;
}
BLKDBG_EVENT(bs->file, BLKDBG_L1_UPDATE);
ret = bdrv_pwrite_sync(bs->file, s->l1_table_offset + 8 * l1_start_index,
buf, sizeof(buf));
@ -368,6 +383,12 @@ static int coroutine_fn copy_sectors(BlockDriverState *bs,
&s->aes_encrypt_key);
}
ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_DEFAULT,
cluster_offset + n_start * BDRV_SECTOR_SIZE, n * BDRV_SECTOR_SIZE);
if (ret < 0) {
goto out;
}
BLKDBG_EVENT(bs->file, BLKDBG_COW_WRITE);
ret = bdrv_co_writev(bs->file, (cluster_offset >> 9) + n_start, n, &qiov);
if (ret < 0) {