ext2: correct max file size computing
[ Upstream commit 50b3a818991074177a56c87124c7a7bdf5fa4f67 ]
We need to calculate the max file size accurately if the total blocks
that can address by block tree exceed the upper_limit. But this check is
not correct now, it only compute the total data blocks but missing
metadata blocks are needed. So in the case of "data blocks < upper_limit
&& total blocks > upper_limit", we will get wrong result. Fortunately,
this case could not happen in reality, but it's confused and better to
correct the computing.
bits data blocks metadatablocks upper_limit
10 16843020 66051 2147483647
11 134480396 263171 1073741823
12 1074791436 1050627 536870911 (*)
13 8594130956 4198403 268435455 (*)
14 68736258060 16785411 134217727 (*)
15 549822930956 67125251 67108863 (*)
16 4398314962956 268468227 33554431 (*)
[*] Need to calculate in depth.
Fixes: 1c2d14212b15 ("ext2: Fix underflow in ext2_max_size()")
Link: https://lore.kernel.org/r/20220212050532.179055-1-yi.zhang@huawei.com
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Sasha Levin <sashal@kernel.org>
1 file changed