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Message-ID: <9fdf92e9-ad77-4184-9418-8a209e24ec20@oracle.com>
Date: Wed, 13 Mar 2024 18:40:53 +0000
User-Agent: Mozilla Thunderbird
Subject: Re: [RFC] ext4: Add support for ext4_map_blocks_atomic()
Content-Language: en-US
To: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>,
        linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org
Cc: Jan Kara <jack@suse.cz>, Theodore Ts'o <tytso@mit.edu>,
        Ojaswin Mujoo <ojaswin@linux.ibm.com>,
        Matthew Wilcox <willy@infradead.org>,
        "Darrick J . Wong" <djwong@kernel.org>,
        Luis Chamberlain
 <mcgrof@kernel.org>, linux-kernel@vger.kernel.org,
        Dave Chinner <david@fromorbit.com>
References: <e4bd58d4-723f-4c94-bf46-826bceeb6a8d@oracle.com>
 <3a417188e5abe3048afac3d31ebbf11588b6d68d.1709927824.git.ritesh.list@gmail.com>
From: John Garry <john.g.garry@oracle.com>
Organization: Oracle Corporation
In-Reply-To: <3a417188e5abe3048afac3d31ebbf11588b6d68d.1709927824.git.ritesh.list@gmail.com>
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On 08/03/2024 20:25, Ritesh Harjani (IBM) wrote:

Hi Ritesh,

> Currently ext4 exposes [fsawu_min, fsawu_max] size as
> [blocksize, clustersize] (given the hw block device constraints are
> larger than FS atomic write units).
> 
> That means a user should be allowed to -
> 1. pwrite 0 4k /mnt/test/f1
> 2. pwrite 0 16k /mnt/test/f1
> 

Previously you have mentioned 2 or 3 methods in which ext4 could support 
atomic writes. To avoid doubt, is this patch for the "Add intelligence 
in multi-block allocator of ext4 to provide aligned allocations (this 
option won't require any formatting)" method mentioned at 
https://lore.kernel.org/linux-fsdevel/8734tb0xx7.fsf@doe.com/

and same as method 3 at 
https://lore.kernel.org/linux-fsdevel/cover.1709356594.git.ritesh.list@gmail.com/? 


Thanks,
John