From:   Jens Axboe <axboe@kernel.dk>
To:     Al Viro <viro@zeniv.linux.org.uk>,
        Christoph Hellwig <hch@infradead.org>,
        David Howells <dhowells@redhat.com>
Cc:     Matthew Wilcox <willy@infradead.org>, Jan Kara <jack@suse.cz>,
        Jeff Layton <jlayton@kernel.org>,
        David Hildenbrand <david@redhat.com>,
        Logan Gunthorpe <logang@deltatee.com>,
        Hillf Danton <hdanton@sina.com>,
        Christian Brauner <brauner@kernel.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        Jason Gunthorpe <jgg@ziepe.ca>
In-Reply-To: <20230315163549.295454-1-dhowells@redhat.com>
References: <20230315163549.295454-1-dhowells@redhat.com>
Subject: Re: [PATCH v19 00/15] splice, block: Use page pinning and kill
 ITER_PIPE
Message-Id: <167890243414.54517.7660243890362126266.b4-ty@kernel.dk>
Date:   Wed, 15 Mar 2023 11:47:14 -0600
MIME-Version: 1.0
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: 7bit
Precedence: bulk


On Wed, 15 Mar 2023 16:35:34 +0000, David Howells wrote:
> The first half of this patchset kills off ITER_PIPE to avoid a race between
> truncate, iov_iter_revert() on the pipe and an as-yet incomplete DMA to a
> bio with unpinned/unref'ed pages from an O_DIRECT splice read.  This causes
> memory corruption[2].  Instead, we use filemap_splice_read(), which invokes
> the buffered file reading code and splices from the pagecache into the
> pipe; direct_splice_read(), which bulk-allocates a buffer, reads into it
> and then pushes the filled pages into the pipe; or handle it in
> filesystem-specific code.
> 
> [...]

Applied, thanks!

[01/15] splice: Clean up direct_splice_read() a bit
        commit: d187b44bc9404581bad8d006d80937d1b3a2b0c0
[02/15] splice: Make do_splice_to() generic and export it
        commit: 6dc39c2949ee71ee9996d6190d374512ecf44982
[03/15] shmem: Implement splice-read
        commit: b81d7b89beccbeebe347c21c004665ffe07e36bb
[04/15] overlayfs: Implement splice-read
        commit: f39de7bd1b5088241f0580b5fe5d76cc5569711f
[05/15] coda: Implement splice-read
        commit: f0daac2d4dcd286168d7c70d0495328c096d4d96
[06/15] tty, proc, kernfs, random: Use direct_splice_read()
        commit: 82ab8404c910d4aba33f55257c2bbc8ea9cfad3c
[07/15] splice: Do splice read from a file without using ITER_PIPE
        commit: 3eb3c59b128509a5e8a8349dafced64b9769438e
[08/15] cifs: Use generic_file_splice_read()
        commit: fa9a848ded4984a8c64d0d20c3a5b0aab97c7754
[09/15] iov_iter: Kill ITER_PIPE
        commit: a53f5dee3448a51e6602a7f98952abaf19049641
[10/15] iomap: Don't get an reference on ZERO_PAGE for direct I/O block zeroing
        commit: 2102c4e41418fb5c2cdf26bf2b97922190e38ba2
[11/15] block: Fix bio_flagged() so that gcc can better optimise it
        commit: caf8aae59a7b1f668a32f91115ed8be3aebaaa41
[12/15] block: Replace BIO_NO_PAGE_REF with BIO_PAGE_REFFED with inverted logic
        commit: e812d15adde4363c95f1743b7dd4946f1a550c5c
[13/15] block: Add BIO_PAGE_PINNED and associated infrastructure
        commit: b5596bf292996a5cd62f1fbc00c2c35f1a3faa12
[14/15] block: Convert bio_iov_iter_get_pages to use iov_iter_extract_pages
        commit: 648627d7077d4de810e5f4c09490cb993514a53f
[15/15] block: convert bio_map_user_iov to use iov_iter_extract_pages
        commit: d187b44bc9404581bad8d006d80937d1b3a2b0c0

Best regards,
-- 
Jens Axboe