From: Qu Wenruo <quwenruo.btrfs@gmx.com>
To: dsterba@suse.cz, Qu Wenruo <wqu@suse.com>,
linux-btrfs@vger.kernel.org,
Christian Zangl <coralllama@gmail.com>
Subject: Re: [PATCH 1/2] btrfs-progs: convert: Prevent bit overflow for cctx->total_bytes
Date: Tue, 21 Jul 2020 07:51:00 +0800 [thread overview]
Message-ID: <cf6386e1-a13b-e7cf-a365-db33a3afe2a9@gmx.com> (raw)
In-Reply-To: <20200720160945.GH3703@twin.jikos.cz>
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On 2020/7/21 上午12:09, David Sterba wrote:
> On Mon, Jul 20, 2020 at 08:51:08PM +0800, Qu Wenruo wrote:
>> --- a/convert/source-ext2.c
>> +++ b/convert/source-ext2.c
>> @@ -87,7 +87,8 @@ static int ext2_open_fs(struct btrfs_convert_context *cctx, const char *name)
>> cctx->fs_data = ext2_fs;
>> cctx->blocksize = ext2_fs->blocksize;
>> cctx->block_count = ext2_fs->super->s_blocks_count;
>> - cctx->total_bytes = ext2_fs->blocksize * ext2_fs->super->s_blocks_count;
>> + cctx->total_bytes = (u64)ext2_fs->blocksize *
>> + (u64)ext2_fs->super->s_blocks_count;
>
> Do you need to cast both? Once one of the types is wide enough for the
> result, there should be no loss.
>
I just want to be extra safe.
Feel free to reduce one.
Thanks,
Qu
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next prev parent reply other threads:[~2020-07-20 23:56 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-20 12:51 [PATCH 1/2] btrfs-progs: convert: Prevent bit overflow for cctx->total_bytes Qu Wenruo
2020-07-20 12:51 ` [PATCH 2/2] btrfs-progs: convert-tests: Add test case for multiply overflow Qu Wenruo
2020-07-20 12:53 ` [PATCH 1/2] btrfs-progs: convert: Prevent bit overflow for cctx->total_bytes Nikolay Borisov
2020-07-20 16:09 ` David Sterba
2020-07-20 23:51 ` Qu Wenruo [this message]
2020-07-21 9:58 ` David Sterba
2020-07-21 10:29 ` Qu Wenruo
2020-07-21 13:55 ` David Sterba
2020-07-21 22:58 ` Qu Wenruo
2020-07-22 11:32 ` David Sterba
2020-07-23 13:31 ` Neal Gompa
2020-07-24 0:01 ` Qu Wenruo
2020-07-28 13:14 ` Neal Gompa
2020-07-28 13:19 ` Qu Wenruo
2020-07-29 1:56 ` Neal Gompa
2020-07-29 2:30 ` Qu Wenruo
2020-07-21 13:57 ` Stefan Traby
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