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From: David Howells <dhowells@redhat.com>
To: linux-fsdevel@vger.kernel.org
Cc: dhowells@redhat.com, jlayton@kernel.org,
	Matthew Wilcox <willy@infradead.org>,
	Christoph Hellwig <hch@infradead.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	dchinner@redhat.com, linux-block@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Could it be made possible to offer "supplementary" data to a DIO write ?
Date: Thu, 05 Aug 2021 11:19:17 +0100	[thread overview]
Message-ID: <1017390.1628158757@warthog.procyon.org.uk> (raw)

Hi,

I'm working on network filesystem write helpers to go with the read helpers,
and I see situations where I want to write a few bytes to the cache, but have
more available that could be written also if it would allow the
filesystem/blockdev to optimise its layout.

Say, for example, I need to write a 3-byte change from a page, where that page
is part of a 256K sequence in the pagecache.  Currently, I have to round the
3-bytes out to DIO size/alignment, but I could say to the API, for example,
"here's a 256K iterator - I need bytes 225-227 written, but you can write more
if you want to"?

Would it be useful/feasible to have some sort of interface that allows the
offer to be made?

David


             reply	other threads:[~2021-08-05 10:19 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-05 10:19 David Howells [this message]
2021-08-05 12:37 ` Could it be made possible to offer "supplementary" data to a DIO write ? Matthew Wilcox
2021-08-05 13:07 ` David Howells
2021-08-05 13:35   ` Matthew Wilcox
2021-08-05 14:38   ` David Howells
2021-08-05 15:06     ` Matthew Wilcox
2021-08-05 15:38     ` David Howells
2021-08-05 16:35     ` Canvassing for network filesystem write size vs page size David Howells
2021-08-05 17:27       ` Linus Torvalds
2021-08-05 17:43         ` Trond Myklebust
2021-08-05 22:11         ` Matthew Wilcox
2021-08-06 13:42         ` David Howells
2021-08-06 14:17           ` Matthew Wilcox
2021-08-06 15:04           ` David Howells
2021-08-05 17:52       ` Adam Borowski
2021-08-05 18:50       ` Jeff Layton
2021-08-05 23:47       ` Matthew Wilcox
2021-08-06 13:44       ` David Howells
2021-08-05 17:45     ` Could it be made possible to offer "supplementary" data to a DIO write ? Adam Borowski

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