public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Al Viro <viro@zeniv.linux.org.uk>
To: Christoph Hellwig <hch@lst.de>
Cc: Joel Stanley <joel@jms.id.au>,
	David Woodhouse <dwmw2@infradead.org>,
	Richard Weinberger <richard@nod.at>,
	Kees Cook <keescook@chromium.org>,
	"William A . Kennington III" <wak@google.com>,
	Lei YU <mine260309@gmail.com>,
	linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] jffs2: Hook up splice_write callback
Date: Tue, 30 Mar 2021 18:31:00 +0000	[thread overview]
Message-ID: <YGNuZMUkzH0tkce6@zeniv-ca.linux.org.uk> (raw)
In-Reply-To: <20210330161715.GA12783@lst.de>

On Tue, Mar 30, 2021 at 06:17:15PM +0200, Christoph Hellwig wrote:
> On Wed, Mar 31, 2021 at 12:15:37AM +1030, Joel Stanley wrote:
> > overlayfs using jffs2 as the upper filesystem would fail in some cases
> > since moving to v5.10. The test case used was to run 'touch' on a file
> > that exists in the lower fs, causing the modification time to be
> > updated. It returns EINVAL when the bug is triggered.
> > 
> > A bisection showed this was introduced in v5.9-rc1, with commit
> > 36e2c7421f02 ("fs: don't allow splice read/write without explicit ops").
> > Reverting that commit restores the expected behaviour.
> > 
> > Some digging showed that this was due to jffs2 lacking an implementation
> > of splice_write. (For unknown reasons the warn_unsupported that should
> > trigger was not displaying any output).
> > 
> > Adding this patch resolved the issue and the test now passes.
> 
> Looks good:
> 
> Reviewed-by: Christoph Hellwig <hch@lst.de>

The same goes for quite a few other filesystems, actually - at least
adfs, affs, bfs, hfs, hfsplus, hostfs, hpfs, minix, omfs, sysv, ufs 
and vboxsf are in the same boat, and I suspect that ecryptfs and ntfs
might be too.

Christoph, do you see any problems with doing the same thing for that
bunch as well?

  reply	other threads:[~2021-03-30 18:32 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-30 13:45 [PATCH] jffs2: Hook up splice_write callback Joel Stanley
2021-03-30 16:17 ` Christoph Hellwig
2021-03-30 18:31   ` Al Viro [this message]
2021-03-30 18:38     ` Al Viro
2021-03-31 14:44     ` Christoph Hellwig
2021-03-31  4:55 ` Lei YU

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=YGNuZMUkzH0tkce6@zeniv-ca.linux.org.uk \
    --to=viro@zeniv.linux.org.uk \
    --cc=dwmw2@infradead.org \
    --cc=hch@lst.de \
    --cc=joel@jms.id.au \
    --cc=keescook@chromium.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mtd@lists.infradead.org \
    --cc=mine260309@gmail.com \
    --cc=richard@nod.at \
    --cc=wak@google.com \
    /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