From 175e11526e2613b3dc031c23fec3107aa4a80307 Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Wed, 12 May 2010 16:23:26 +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 --- block/qcow2-cluster.c | 23 +++++++++++++---------- 1 file changed, 13 insertions(+), 10 deletions(-) (limited to 'block') diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index ed5c4b2..244b4a7 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -239,14 +239,6 @@ static int l2_allocate(BlockDriverState *bs, int l1_index, uint64_t **table) return l2_offset; } - /* update the L1 entry */ - - s->l1_table[l1_index] = l2_offset | QCOW_OFLAG_COPIED; - ret = write_l1_entry(bs, l1_index); - if (ret < 0) { - return ret; - } - /* allocate a new entry in the l2 cache */ min_index = l2_cache_new_entry(bs); @@ -261,7 +253,7 @@ static int l2_allocate(BlockDriverState *bs, int l1_index, uint64_t **table) ret = bdrv_pread(bs->file, old_l2_offset, l2_table, s->l2_size * sizeof(uint64_t)); if (ret < 0) { - return ret; + goto fail; } } /* write the l2 table to the file */ @@ -269,7 +261,14 @@ static int l2_allocate(BlockDriverState *bs, int l1_index, uint64_t **table) ret = bdrv_pwrite(bs->file, l2_offset, l2_table, s->l2_size * sizeof(uint64_t)); if (ret < 0) { - return ret; + goto fail; + } + + /* update the L1 entry */ + s->l1_table[l1_index] = l2_offset | QCOW_OFLAG_COPIED; + ret = write_l1_entry(bs, l1_index); + if (ret < 0) { + goto fail; } /* update the l2 cache entry */ @@ -279,6 +278,10 @@ static int l2_allocate(BlockDriverState *bs, int l1_index, uint64_t **table) *table = l2_table; return 0; + +fail: + qcow2_l2_cache_reset(bs); + return ret; } static int count_contiguous_clusters(uint64_t nb_clusters, int cluster_size, -- cgit v1.1