linux-kernel - Re: [PATCH] btrfs: avoid opencoded 64-bit div/mod operation

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Message-ID: <859ef104-2665-4de3-8d28-7652035d7fbc@oracle.com>
Date: Mon, 16 Dec 2024 14:52:35 +0530
From: Anand Jain <anand.jain@...cle.com>
To: Qu Wenruo <quwenruo.btrfs@....com>, Arnd Bergmann <arnd@...nel.org>,
        Chris Mason <clm@...com>, Josef Bacik <josef@...icpanda.com>,
        David Sterba <dsterba@...e.com>
Cc: Arnd Bergmann <arnd@...db.de>, Qu Wenruo <wqu@...e.com>,
        Johannes Thumshirn <johannes.thumshirn@....com>,
        Boris Burkov
 <boris@....io>, Naohiro Aota <naohiro.aota@....com>,
        linux-btrfs@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] btrfs: avoid opencoded 64-bit div/mod operation




>> @@ -1433,7 +1433,9 @@ static ssize_t btrfs_read_policy_store(struct 
>> kobject *kobj,
>>   #ifdef CONFIG_BTRFS_EXPERIMENTAL
>>       if (index == BTRFS_READ_POLICY_RR) {
>>           if (value != -1) {
>> -            if ((value % fs_devices->fs_info->sectorsize) != 0) {
>> +            u32 rem;
>> +            div_u64_rem(value, fs_devices->fs_info->sectorsize, &rem);
> 
> The original check is already bad, it's just a IS_ALIGNED().
> 
> So a much simpler solution is:
> 
> +            if (!IS_ALIGNED(value, fs_info->sectorsize)) {

Right, this was also in the review comment by David, and the change
is already in the local work-space. I will be sending v4 out.
Currently dealing with some rebase issues.

Thanks,   Anand