| Message ID | 20201105155122.60943-1-eblake@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v4] block: Fix integer promotion error in bdrv_getlength() | expand |
diff --git a/block.c b/block.c index 56bacc9e9f13..2fd932154e12 100644 --- a/block.c +++ b/block.c @@ -5091,8 +5091,13 @@ int64_t bdrv_getlength(BlockDriverState *bs) { int64_t ret = bdrv_nb_sectors(bs); - ret = ret > INT64_MAX / BDRV_SECTOR_SIZE ? -EFBIG : ret; - return ret < 0 ? ret : ret * BDRV_SECTOR_SIZE; + if (ret < 0) { + return ret; + } + if (ret > INT64_MAX / BDRV_SECTOR_SIZE) { + return -EFBIG; + } + return ret * BDRV_SECTOR_SIZE; } /* return 0 as number of sectors if no device present or error */
Back in 2015, we attempted to fix error reporting for images that claimed to have more than INT64_MAX/512 sectors, but due to the type promotions caused by BDRV_SECTOR_SIZE being unsigned, this inadvertently forces all negative ret values to be slammed into -EFBIG rather than the original error. While we're at it, we can avoid the confusing ?: by spelling the logic more directly. Fixes: 4a9c9ea0d3 Reported-by: Guoyi Tu <tu.guoyi@h3c.com> Signed-off-by: Eric Blake <eblake@redhat.com> --- block.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)