From: David Howells <dhowells@redhat.com>
To: Christoph Hellwig <hch@infradead.org>
Cc: dhowells@redhat.com, nicolas.baranger@3xo.fr,
linux-cifs@vger.kernel.org, netfs@lists.linux.dev
Subject: Re: Losetup Direct I/O breaks BACK-FILE filesystem on CIFS share (Appears in Linux 6.10 and reproduced on mainline)
Date: Mon, 06 Jan 2025 09:13:02 +0000 [thread overview]
Message-ID: <278655.1736154782@warthog.procyon.org.uk> (raw)
In-Reply-To: <Z3uENYsAlKhUdQgY@infradead.org>
Christoph Hellwig <hch@infradead.org> wrote:
> > I think the new way CIFS is using NETFS could be one of the cause of the
> > issue, as doing :
>
> The poblem is that netfs_extract_user_iter rejects iter types other than
> ubuf and iovec, which breaks loop which is using bvec iters. It would
> also break other things like io_uring pre-registered buffers, and all
> of these are regressions compared to the old cifs code.
Okay, I can reproduce it trivially. Question is, do I need to copy the
bio_vec array (or kvec array or folio_queue list) or can I rely on that being
maintained till the end of the op? (Obviously, I can't rely on the iov_iter
struct itself being maintained). I think I have to copy the contents, just in
case.
David
next prev parent reply other threads:[~2025-01-06 9:13 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <669f22fc89e45dd4e56d75876dc8f2bf@3xo.fr>
2025-01-01 18:00 ` Losetup Direct I/O breaks BACK-FILE filesystem on CIFS share (Appears in Linux 6.10 and reproduced on mainline) nicolas.baranger
2025-01-06 7:20 ` Christoph Hellwig
2025-01-06 9:13 ` David Howells [this message]
2025-01-06 9:16 ` Christoph Hellwig
2025-01-06 11:37 ` [PATCH] netfs: Fix kernel async DIO David Howells
2025-01-06 12:07 ` nicolas.baranger
2025-01-07 8:26 ` nicolas.baranger
2025-01-07 14:49 ` David Howells
2025-01-07 18:08 ` Nicolas Baranger
2025-01-06 15:34 ` Christoph Hellwig
2025-03-20 8:46 ` [Linux 6.14 - netfs/cifs] loop on file cat + file copy Nicolas Baranger
2025-01-07 12:03 ` [PATCH] netfs: Fix kernel async DIO Paulo Alcantara
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