From: John Garry <john.g.garry@oracle.com>
To: Vitaliy Filippov <vitalifster@gmail.com>
Cc: linux-block@vger.kernel.org, linux-nvme@lists.infradead.org,
linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH] fs: remove power of 2 and length boundary atomic write restrictions
Date: Tue, 6 Jan 2026 11:26:51 +0000 [thread overview]
Message-ID: <58a89dc4-1bc9-4b38-a8cc-d0097ee74b29@oracle.com> (raw)
In-Reply-To: <CAPqjcqo=A45mK01h+o3avOUaSSSX6g_y3FfvCFLRoO7YEwUddw@mail.gmail.com>
On 06/01/2026 10:50, Vitaliy Filippov wrote:
>> If a user follows the current rules, they will not get a write which
>> spans multiple extents and hence no -EINVAL. That is how it works for
>> ext4, anyway.
>
> What if he makes a sparse file by writing at random 64 kb aligned
> offsets and then trying to overwrite 128 KB atomically? He'll still
> get EINVAL as I understand.
For ext4, the maximum atomic write size is limited to the bigalloc
cluster size. Disk blocks are allocated to this cluster size granularity
and alignment. As such, a properly aligned atomic write <= cluster size
can never span discontiguous disk blocks.
next prev parent reply other threads:[~2026-01-06 11:27 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-12-24 11:53 [PATCH] fs: remove power of 2 and length boundary atomic write restrictions Vitaliy Filippov
2025-12-29 7:15 ` kernel test robot
2025-12-30 7:54 ` John Garry
2025-12-30 9:01 ` Vitaliy Filippov
2026-01-02 17:41 ` John Garry
2026-01-05 18:58 ` Vitaliy Filippov
2026-01-06 9:06 ` John Garry
2026-01-06 10:50 ` Vitaliy Filippov
2026-01-06 11:26 ` John Garry [this message]
2026-01-06 13:08 ` Vitaliy Filippov
2026-01-07 10:51 ` John Garry
2026-01-07 13:05 ` Vitaliy Filippov
2026-01-07 15:42 ` John Garry
2026-01-07 16:21 ` Vitaliy Filippov
2026-01-08 18:18 ` Vitaliy Filippov
2026-01-13 14:25 ` Vitaliy Filippov
2026-01-05 19:29 ` Vitaliy Filippov
2026-01-05 19:44 ` Vitaliy Filippov
2026-01-06 10:55 ` Vitaliy Filippov
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