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author | Hu Tao <hutao@cn.fujitsu.com> | 2014-01-26 11:12:39 +0800 |
---|---|---|
committer | Kevin Wolf <kwolf@redhat.com> | 2014-02-09 09:12:39 +0100 |
commit | 7c2bbf4aa66ca5a9fc2ca147e0e6cb6f407a3aa2 (patch) | |
tree | 31daaf4d5aa0dd928d6da2cea12856fe7e08b511 | |
parent | 33304ec9fa484e765c6249673e09e1b7d49c5b85 (diff) | |
download | hqemu-7c2bbf4aa66ca5a9fc2ca147e0e6cb6f407a3aa2.zip hqemu-7c2bbf4aa66ca5a9fc2ca147e0e6cb6f407a3aa2.tar.gz |
qcow2: check for NULL l2meta
In the case of a metadata preallocation with a large cluster size,
qcow2_alloc_cluster_offset() can allocate nothing and returns a
NULL l2meta. This patch checks for it and link2 l2 with only valid
l2meta.
Replace 9 and 512 with BDRV_SECTOR_BITS, BDRV_SECTOR_SIZE
respectively while at the function.
Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
-rw-r--r-- | block/qcow2.c | 31 |
1 files changed, 16 insertions, 15 deletions
diff --git a/block/qcow2.c b/block/qcow2.c index a274d5f..0b4335c 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -1404,34 +1404,34 @@ static int preallocate(BlockDriverState *bs) int ret; QCowL2Meta *meta; - nb_sectors = bdrv_getlength(bs) >> 9; + nb_sectors = bdrv_getlength(bs) >> BDRV_SECTOR_BITS; offset = 0; while (nb_sectors) { - num = MIN(nb_sectors, INT_MAX >> 9); + num = MIN(nb_sectors, INT_MAX >> BDRV_SECTOR_BITS); ret = qcow2_alloc_cluster_offset(bs, offset, &num, &host_offset, &meta); if (ret < 0) { return ret; } - ret = qcow2_alloc_cluster_link_l2(bs, meta); - if (ret < 0) { - qcow2_free_any_clusters(bs, meta->alloc_offset, meta->nb_clusters, - QCOW2_DISCARD_NEVER); - return ret; - } - - /* There are no dependent requests, but we need to remove our request - * from the list of in-flight requests */ if (meta != NULL) { + ret = qcow2_alloc_cluster_link_l2(bs, meta); + if (ret < 0) { + qcow2_free_any_clusters(bs, meta->alloc_offset, + meta->nb_clusters, QCOW2_DISCARD_NEVER); + return ret; + } + + /* There are no dependent requests, but we need to remove our + * request from the list of in-flight requests */ QLIST_REMOVE(meta, next_in_flight); } /* TODO Preallocate data if requested */ nb_sectors -= num; - offset += num << 9; + offset += num << BDRV_SECTOR_BITS; } /* @@ -1440,9 +1440,10 @@ static int preallocate(BlockDriverState *bs) * EOF). Extend the image to the last allocated sector. */ if (host_offset != 0) { - uint8_t buf[512]; - memset(buf, 0, 512); - ret = bdrv_write(bs->file, (host_offset >> 9) + num - 1, buf, 1); + uint8_t buf[BDRV_SECTOR_SIZE]; + memset(buf, 0, BDRV_SECTOR_SIZE); + ret = bdrv_write(bs->file, (host_offset >> BDRV_SECTOR_BITS) + num - 1, + buf, 1); if (ret < 0) { return ret; } |