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bh=Dnh9Ymd0aXLnszSbYXuRCQIZeE9p62JOLrx7AW+9I7M=; b=hZuRQuWiIObrG8OZLCXIAH+V81zmN5wSmepeLjj3s8zuFYjXSue/oqE269U5tSGMmYK0zV X1spbOcOjIAoGzIm/7xCaU5kE0ZD9WXbknXenGV8cmRDHqyxabxX/4dIEGvCkhc0gitBfw V4Mf0m68ag2wRIcIg1M8SBlSkKOtmbc= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-138-tBX-uUEGPaSF-e1H0150-Q-1; Thu, 25 May 2023 11:51:08 -0400 X-MC-Unique: tBX-uUEGPaSF-e1H0150-Q-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 7E1DD8030D2; Thu, 25 May 2023 15:51:07 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.39.192.68]) by smtp.corp.redhat.com (Postfix) with ESMTP id 7180D200BA65; Thu, 25 May 2023 15:51:04 +0000 (UTC) From: David Howells To: Christoph Hellwig , David Hildenbrand Cc: David Howells , Jens Axboe , Al Viro , Matthew Wilcox , Jan Kara , Jeff Layton , Jason Gunthorpe , Logan Gunthorpe , Hillf Danton , Christian Brauner , Linus Torvalds , linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [RFC PATCH 0/3] block: Make old dio use iov_iter_extract_pages() and page pinning Date: Thu, 25 May 2023 16:50:59 +0100 Message-Id: <20230525155102.87353-1-dhowells@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.4 X-Rspam-User: X-Stat-Signature: negu9mgceyktx8ore1aedfodqgc8wts8 X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: E540F4001B X-HE-Tag: 1685029875-495479 X-HE-Meta: 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 6TmzX8/m F0sxyjzsoqf/0zheQj8ciNaBRU5ofxCFhO6LtZxRTMHX+ZbG0Pagh0bKwxrQlha5LzIRilx2XpEqwgGSxLVYwzCnSI3zH4EQ26GTBSXGVA9lUJkV1CD9RJqWvY93qRoG+B/XmEsR6pUArTKhERzFDtFs7E80d6FiDWJQ1mjTR0fs4pppvdcRkHODCLnyJuuSjfom317h1NghlLNCW+uDEaHb5alRNIn6hE+iNtO5SbpLJIOZPS8OdWKXMH+Etv0of91ZNtB1QJ6SVZopEtxXfoZM9lr/IObYHPXf05zgsJQfAlUCuwlfhMHoFrPNMVIycseWm X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Hi Christoph, David, Since Christoph asked nicely[1] ;-), here are three patches that go on top of the similar patches for bio structs now in the block tree that make the old block direct-IO code use iov_iter_extract_pages() and page pinning. There are three patches: (1) Make page pinning not add or remove a pin to/from the ZERO_PAGE, thereby allowing the dio code to insert zero pages in the middle of dealing with pinned pages. (2) Provide a function to allow an additional pin to be taken on a page we already have pinned (and do nothing for the zero page). (3) Switch direct-io.c over to using page pinning and to use iov_iter_extract_pages() so that pages from non-user-backed iterators aren't pinned. Note that I haven't managed to test this yet as SELinux is refusing to let me mount things like ext2 filesystems on account of it not having xattrs:-/ I've pushed the patches here also: https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git/log/?h=iov-old-dio David Link: https://lore.kernel.org/r/ZGxfrOLZ4aN9/MvE@infradead.org/ [1] David Howells (3): mm: Don't pin ZERO_PAGE in pin_user_pages() mm: Provide a function to get an additional pin on a page block: Use iov_iter_extract_pages() and page pinning in direct-io.c fs/direct-io.c | 68 ++++++++++++++++++++++++++++------------------ include/linux/mm.h | 1 + mm/gup.c | 54 +++++++++++++++++++++++++++++++++++- 3 files changed, 95 insertions(+), 28 deletions(-)