From b6d36def6d9e9fd187327182d0abafc9b7085d8f Mon Sep 17 00:00:00 2001 From: Max Reitz Date: Mon, 14 Sep 2015 16:39:47 +0200 Subject: [PATCH] qcow2: Make size_to_clusters() return uint64_t Sadly, some images may have more clusters than what can be represented using a plain int. We should be prepared for that case (in qcow2_check_refcounts() we actually were trying to catch that case, but since size_to_clusters() truncated the returned value, that check never did anything useful). Cc: qemu-stable Signed-off-by: Max Reitz Signed-off-by: Kevin Wolf --- block/qcow2-cluster.c | 28 ++++++++++++++++++---------- block/qcow2-refcount.c | 12 ++++++++---- block/qcow2.h | 6 +++--- 3 files changed, 29 insertions(+), 17 deletions(-) diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index 412ee274ff..6ede629efb 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -298,7 +298,7 @@ fail: * as contiguous. (This allows it, for example, to stop at the first compressed * cluster which may require a different handling) */ -static int count_contiguous_clusters(uint64_t nb_clusters, int cluster_size, +static int count_contiguous_clusters(int nb_clusters, int cluster_size, uint64_t *l2_table, uint64_t stop_flags) { int i; @@ -321,7 +321,7 @@ static int count_contiguous_clusters(uint64_t nb_clusters, int cluster_size, return i; } -static int count_contiguous_free_clusters(uint64_t nb_clusters, uint64_t *l2_table) +static int count_contiguous_free_clusters(int nb_clusters, uint64_t *l2_table) { int i; @@ -495,6 +495,7 @@ int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset, if (nb_needed > nb_available) { nb_needed = nb_available; } + assert(nb_needed <= INT_MAX); *cluster_offset = 0; @@ -530,6 +531,8 @@ int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset, l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1); *cluster_offset = be64_to_cpu(l2_table[l2_index]); + + /* nb_needed <= INT_MAX, thus nb_clusters <= INT_MAX, too */ nb_clusters = size_to_clusters(s, nb_needed << 9); ret = qcow2_get_cluster_type(*cluster_offset); @@ -960,7 +963,7 @@ static int handle_copied(BlockDriverState *bs, uint64_t guest_offset, int l2_index; uint64_t cluster_offset; uint64_t *l2_table; - unsigned int nb_clusters; + uint64_t nb_clusters; unsigned int keep_clusters; int ret; @@ -979,6 +982,7 @@ static int handle_copied(BlockDriverState *bs, uint64_t guest_offset, l2_index = offset_to_l2_index(s, guest_offset); nb_clusters = MIN(nb_clusters, s->l2_size - l2_index); + assert(nb_clusters <= INT_MAX); /* Find L2 entry for the first involved cluster */ ret = get_cluster_table(bs, guest_offset, &l2_table, &l2_index); @@ -1061,7 +1065,7 @@ out: * restarted, but the whole request should not be failed. */ static int do_alloc_cluster_offset(BlockDriverState *bs, uint64_t guest_offset, - uint64_t *host_offset, unsigned int *nb_clusters) + uint64_t *host_offset, uint64_t *nb_clusters) { BDRVQcow2State *s = bs->opaque; @@ -1079,7 +1083,7 @@ static int do_alloc_cluster_offset(BlockDriverState *bs, uint64_t guest_offset, *host_offset = cluster_offset; return 0; } else { - int ret = qcow2_alloc_clusters_at(bs, *host_offset, *nb_clusters); + int64_t ret = qcow2_alloc_clusters_at(bs, *host_offset, *nb_clusters); if (ret < 0) { return ret; } @@ -1115,7 +1119,7 @@ static int handle_alloc(BlockDriverState *bs, uint64_t guest_offset, int l2_index; uint64_t *l2_table; uint64_t entry; - unsigned int nb_clusters; + uint64_t nb_clusters; int ret; uint64_t alloc_cluster_offset; @@ -1133,6 +1137,7 @@ static int handle_alloc(BlockDriverState *bs, uint64_t guest_offset, l2_index = offset_to_l2_index(s, guest_offset); nb_clusters = MIN(nb_clusters, s->l2_size - l2_index); + assert(nb_clusters <= INT_MAX); /* Find L2 entry for the first involved cluster */ ret = get_cluster_table(bs, guest_offset, &l2_table, &l2_index); @@ -1426,7 +1431,8 @@ int qcow2_decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset) * clusters. */ static int discard_single_l2(BlockDriverState *bs, uint64_t offset, - unsigned int nb_clusters, enum qcow2_discard_type type, bool full_discard) + uint64_t nb_clusters, enum qcow2_discard_type type, + bool full_discard) { BDRVQcow2State *s = bs->opaque; uint64_t *l2_table; @@ -1441,6 +1447,7 @@ static int discard_single_l2(BlockDriverState *bs, uint64_t offset, /* Limit nb_clusters to one L2 table */ nb_clusters = MIN(nb_clusters, s->l2_size - l2_index); + assert(nb_clusters <= INT_MAX); for (i = 0; i < nb_clusters; i++) { uint64_t old_l2_entry; @@ -1503,7 +1510,7 @@ int qcow2_discard_clusters(BlockDriverState *bs, uint64_t offset, { BDRVQcow2State *s = bs->opaque; uint64_t end_offset; - unsigned int nb_clusters; + uint64_t nb_clusters; int ret; end_offset = offset + (nb_sectors << BDRV_SECTOR_BITS); @@ -1545,7 +1552,7 @@ fail: * clusters. */ static int zero_single_l2(BlockDriverState *bs, uint64_t offset, - unsigned int nb_clusters) + uint64_t nb_clusters) { BDRVQcow2State *s = bs->opaque; uint64_t *l2_table; @@ -1560,6 +1567,7 @@ static int zero_single_l2(BlockDriverState *bs, uint64_t offset, /* Limit nb_clusters to one L2 table */ nb_clusters = MIN(nb_clusters, s->l2_size - l2_index); + assert(nb_clusters <= INT_MAX); for (i = 0; i < nb_clusters; i++) { uint64_t old_offset; @@ -1584,7 +1592,7 @@ static int zero_single_l2(BlockDriverState *bs, uint64_t offset, int qcow2_zero_clusters(BlockDriverState *bs, uint64_t offset, int nb_sectors) { BDRVQcow2State *s = bs->opaque; - unsigned int nb_clusters; + uint64_t nb_clusters; int ret; /* The zero flag is only supported by version 3 and newer */ diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c index b780bb92c6..a49d59e71e 100644 --- a/block/qcow2-refcount.c +++ b/block/qcow2-refcount.c @@ -875,8 +875,8 @@ int64_t qcow2_alloc_clusters(BlockDriverState *bs, uint64_t size) return offset; } -int qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset, - int nb_clusters) +int64_t qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset, + int64_t nb_clusters) { BDRVQcow2State *s = bs->opaque; uint64_t cluster_index, refcount; @@ -1259,7 +1259,7 @@ static size_t refcount_array_byte_size(BDRVQcow2State *s, uint64_t entries) static int realloc_refcount_array(BDRVQcow2State *s, void **array, int64_t *size, int64_t new_size) { - size_t old_byte_size, new_byte_size; + int64_t old_byte_size, new_byte_size; void *new_ptr; /* Round to clusters so the array can be directly written to disk */ @@ -1275,13 +1275,17 @@ static int realloc_refcount_array(BDRVQcow2State *s, void **array, assert(new_byte_size > 0); + if (new_byte_size > SIZE_MAX) { + return -ENOMEM; + } + new_ptr = g_try_realloc(*array, new_byte_size); if (!new_ptr) { return -ENOMEM; } if (new_byte_size > old_byte_size) { - memset((void *)((uintptr_t)new_ptr + old_byte_size), 0, + memset((char *)new_ptr + old_byte_size, 0, new_byte_size - old_byte_size); } diff --git a/block/qcow2.h b/block/qcow2.h index 61f1b57a26..d700bf1b62 100644 --- a/block/qcow2.h +++ b/block/qcow2.h @@ -415,7 +415,7 @@ static inline int64_t offset_into_cluster(BDRVQcow2State *s, int64_t offset) return offset & (s->cluster_size - 1); } -static inline int size_to_clusters(BDRVQcow2State *s, int64_t size) +static inline uint64_t size_to_clusters(BDRVQcow2State *s, uint64_t size) { return (size + (s->cluster_size - 1)) >> s->cluster_bits; } @@ -509,8 +509,8 @@ int qcow2_update_cluster_refcount(BlockDriverState *bs, int64_t cluster_index, enum qcow2_discard_type type); int64_t qcow2_alloc_clusters(BlockDriverState *bs, uint64_t size); -int qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset, - int nb_clusters); +int64_t qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset, + int64_t nb_clusters); int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size); void qcow2_free_clusters(BlockDriverState *bs, int64_t offset, int64_t size,