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From: "Darrick J. Wong" <djwong@kernel.org>
To: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	linux-api@vger.kernel.org
Subject: Re: [PATCH 01/18] vfs: introduce new file range exchange ioctl
Date: Thu, 1 Apr 2021 14:18:45 -0700	[thread overview]
Message-ID: <20210401211845.GE4090233@magnolia> (raw)
In-Reply-To: <YGUlavtPLH5tZFT/@zeniv-ca.linux.org.uk>

On Thu, Apr 01, 2021 at 01:44:10AM +0000, Al Viro wrote:
> On Wed, Mar 31, 2021 at 06:08:52PM -0700, Darrick J. Wong wrote:
> 
> > +	ret = vfs_xchg_file_range(file1.file, file2, &args);
> > +	if (ret)
> > +		goto fdput;
> > +
> > +	/*
> > +	 * The VFS will set RANGE_FSYNC on its own if the file or inode require
> > +	 * synchronous writes.  Don't leak this back to userspace.
> > +	 */
> > +	args.flags &= ~FILE_XCHG_RANGE_FSYNC;
> > +	args.flags |= (old_flags & FILE_XCHG_RANGE_FSYNC);
> > +
> > +	if (copy_to_user(argp, &args, sizeof(args)))
> > +		ret = -EFAULT;
> 
> Erm...  How is userland supposed to figure out whether that EFAULT
> came before or after the operation?  Which of the fields are outputs,
> anyway?

Come to think of it, none of the fields are outputs, so this whole block
can go away.  Thanks for noticing that. :)

> > +	/* Don't touch certain kinds of inodes */
> > +	if (IS_IMMUTABLE(inode1) || IS_IMMUTABLE(inode2))
> > +		return -EPERM;
> 
> Append-only should get the same treatment (and IMO if you have

Assuming you meant IS_APPEND, I thought we only checked that at open
time, as part of requiring O_APPEND?

> O_APPEND on either file, you should get a failure as well).

generic_rw_checks (which is called by do_xchg_file_range) will send back
-EBADF if the file descriptors are O_APPEND.

--D

  reply	other threads:[~2021-04-01 21:18 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-01  1:08 [PATCHSET RFC v3 00/18] xfs: atomic file updates Darrick J. Wong
2021-04-01  1:08 ` [PATCH 01/18] vfs: introduce new file range exchange ioctl Darrick J. Wong
2021-04-01  1:44   ` Al Viro
2021-04-01 21:18     ` Darrick J. Wong [this message]
2021-04-01  3:32   ` Amir Goldstein
2021-04-02  0:37     ` Darrick J. Wong
2021-04-01  1:08 ` [PATCH 02/18] xfs: support two inodes in the defer capture structure Darrick J. Wong
2021-04-02 23:20   ` Allison Henderson
2021-04-01  1:09 ` [PATCH 03/18] xfs: allow setting and clearing of log incompat feature flags Darrick J. Wong
2021-04-02 23:20   ` Allison Henderson
2021-04-01  1:09 ` [PATCH 04/18] xfs: clear log incompat feature bits when the log is idle Darrick J. Wong
2021-04-02 23:20   ` Allison Henderson
2021-04-01  1:09 ` [PATCH 05/18] xfs: create a log incompat flag for atomic extent swapping Darrick J. Wong
2021-04-02 23:21   ` Allison Henderson
2021-04-01  1:09 ` [PATCH 06/18] xfs: introduce a swap-extent log intent item Darrick J. Wong
2021-04-05 23:08   ` Allison Henderson
2021-04-01  1:09 ` [PATCH 07/18] xfs: create deferred log items for extent swapping Darrick J. Wong
2021-04-01  1:09 ` [PATCH 08/18] xfs: add a ->xchg_file_range handler Darrick J. Wong
2021-04-01  1:09 ` [PATCH 09/18] xfs: add error injection to test swapext recovery Darrick J. Wong
2021-04-01  1:09 ` [PATCH 10/18] xfs: port xfs_swap_extents_rmap to our new code Darrick J. Wong
2021-04-01  1:09 ` [PATCH 11/18] xfs: consolidate all of the xfs_swap_extent_forks code Darrick J. Wong
2021-04-01  1:09 ` [PATCH 12/18] xfs: refactor reflink flag handling in xfs_swap_extent_forks Darrick J. Wong
2021-04-01  1:09 ` [PATCH 13/18] xfs: allow xfs_swap_range to use older extent swap algorithms Darrick J. Wong
2021-04-01  1:10 ` [PATCH 14/18] xfs: remove old swap extents implementation Darrick J. Wong
2021-04-01  1:10 ` [PATCH 15/18] xfs: condense extended attributes after an atomic swap Darrick J. Wong
2021-04-01  1:10 ` [PATCH 16/18] xfs: condense directories " Darrick J. Wong
2021-04-01  1:10 ` [PATCH 17/18] xfs: make atomic extent swapping support realtime files Darrick J. Wong
2021-04-01  1:10 ` [PATCH 18/18] xfs: enable atomic swapext feature Darrick J. Wong
2021-04-01  3:56 ` [PATCHSET RFC v3 00/18] xfs: atomic file updates Amir Goldstein
2021-04-02  0:22   ` Darrick J. Wong

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