From: Christoph Hellwig <hch@lst.de>
To: Amir Goldstein <amir73il@gmail.com>
Cc: Christian Brauner <brauner@kernel.org>,
Jeff Layton <jlayton@kernel.org>,
Josef Bacik <josef@toxicpanda.com>,
Christoph Hellwig <hch@lst.de>, Jan Kara <jack@suse.cz>,
David Howells <dhowells@redhat.com>, Jens Axboe <axboe@kernel.dk>,
Miklos Szeredi <miklos@szeredi.hu>,
Al Viro <viro@zeniv.linux.org.uk>,
linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH v2 3/3] fs: use do_splice_direct() for nfsd/ksmbd server-side-copy
Date: Mon, 4 Dec 2023 09:39:52 +0100 [thread overview]
Message-ID: <20231204083952.GD32438@lst.de> (raw)
In-Reply-To: <20231130141624.3338942-4-amir73il@gmail.com>
On Thu, Nov 30, 2023 at 04:16:24PM +0200, Amir Goldstein wrote:
> nfsd/ksmbd call vfs_copy_file_range() with flag COPY_FILE_SPLICE to
> perform kernel copy between two files on any two filesystems.
>
> Splicing input file, while holding file_start_write() on the output file
> which is on a different sb, posses a risk for fanotify related deadlocks.
>
> We only need to call splice_file_range() from within the context of
> ->copy_file_range() filesystem methods with file_start_write() held.
>
> To avoid the possible deadlocks, always use do_splice_direct() instead of
> splice_file_range() for the kernel copy fallback in vfs_copy_file_range()
> without holding file_start_write().
Looks good:
Reviewed-by: Christoph Hellwig <hch@lst.de>
(although I wish do_splice_direct had a better name like
vfs_splice_direct, espcially before growing more users)
next prev parent reply other threads:[~2023-12-04 8:39 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-11-30 14:16 [PATCH v2 0/3] Avert possible deadlock with splice() and fanotify Amir Goldstein
2023-11-30 14:16 ` [PATCH v2 1/3] fs: fork splice_file_range() from do_splice_direct() Amir Goldstein
2023-11-30 16:27 ` Jeff Layton
2023-12-04 8:37 ` Christoph Hellwig
2023-12-04 8:38 ` Christoph Hellwig
2023-12-04 13:29 ` Amir Goldstein
2023-12-04 14:07 ` Christoph Hellwig
2023-12-04 14:29 ` Amir Goldstein
2023-12-04 17:16 ` Jan Kara
2023-12-04 18:53 ` Amir Goldstein
2023-11-30 14:16 ` [PATCH v2 2/3] fs: move file_start_write() into direct_splice_actor() Amir Goldstein
2023-12-04 8:38 ` Christoph Hellwig
2023-11-30 14:16 ` [PATCH v2 3/3] fs: use do_splice_direct() for nfsd/ksmbd server-side-copy Amir Goldstein
2023-11-30 16:49 ` Jan Kara
2023-12-04 8:39 ` Christoph Hellwig [this message]
2023-12-04 13:19 ` Amir Goldstein
2023-12-04 14:02 ` Christoph Hellwig
2023-12-05 0:16 ` [PATCH] fs: read_write: make default in vfs_copy_file_range() reachable Bert Karwatzki
2023-12-05 3:45 ` Amir Goldstein
2023-12-05 5:01 ` Amir Goldstein
2023-12-05 9:50 ` Bert Karwatzki
2023-11-30 16:32 ` [PATCH v2 0/3] Avert possible deadlock with splice() and fanotify Jeff Layton
2023-12-01 10:40 ` Christian Brauner
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20231204083952.GD32438@lst.de \
--to=hch@lst.de \
--cc=amir73il@gmail.com \
--cc=axboe@kernel.dk \
--cc=brauner@kernel.org \
--cc=dhowells@redhat.com \
--cc=jack@suse.cz \
--cc=jlayton@kernel.org \
--cc=josef@toxicpanda.com \
--cc=linux-fsdevel@vger.kernel.org \
--cc=miklos@szeredi.hu \
--cc=viro@zeniv.linux.org.uk \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).