From 258e351d128bab86c185aa4836654aebc22a82a1 Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Fri, 28 May 2010 19:12:24 +0200 Subject: qcow2: Fix error handling in l2_allocate l2_allocate has some intermediate states in which the image is inconsistent. Change the order to write to the L1 table only after the new L2 table has successfully been initialized. Also reset the L2 cache in failure case, it's very likely wrong. Signed-off-by: Kevin Wolf (cherry picked from commit 175e11526e2613b3dc031c23fec3107aa4a80307) Conflicts: block/qcow2-cluster.c Signed-off-by: Kevin Wolf --- block/qcow2-cluster.c | 21 ++++++++++++--------- 1 file changed, 12 insertions(+), 9 deletions(-) (limited to 'block') diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index 0dc4f1d8f..b7a5b35f4 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -231,13 +231,6 @@ static uint64_t *l2_allocate(BlockDriverState *bs, int l1_index) return NULL; } - /* update the L1 entry */ - - s->l1_table[l1_index] = l2_offset | QCOW_OFLAG_COPIED; - if (write_l1_entry(s, l1_index) < 0) { - return NULL; - } - /* allocate a new entry in the l2 cache */ min_index = l2_cache_new_entry(bs); @@ -251,13 +244,19 @@ static uint64_t *l2_allocate(BlockDriverState *bs, int l1_index) if (bdrv_pread(s->hd, old_l2_offset, l2_table, s->l2_size * sizeof(uint64_t)) != s->l2_size * sizeof(uint64_t)) - return NULL; + goto fail; } /* write the l2 table to the file */ if (bdrv_pwrite(s->hd, l2_offset, l2_table, s->l2_size * sizeof(uint64_t)) != s->l2_size * sizeof(uint64_t)) - return NULL; + goto fail; + + /* update the L1 entry */ + s->l1_table[l1_index] = l2_offset | QCOW_OFLAG_COPIED; + if (write_l1_entry(s, l1_index) < 0) { + goto fail; + } /* update the l2 cache entry */ @@ -265,6 +264,10 @@ static uint64_t *l2_allocate(BlockDriverState *bs, int l1_index) s->l2_cache_counts[min_index] = 1; return l2_table; + +fail: + qcow2_l2_cache_reset(bs); + return NULL; } static int count_contiguous_clusters(uint64_t nb_clusters, int cluster_size, -- cgit v1.2.3-65-gdbad