linux-kernel - Re: [PATCH v6 04/13] xfs: pass flags to xfs_reflink_allocate

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250317061523.GD27019@lst.de>
Date: Mon, 17 Mar 2025 07:15:23 +0100
From: Christoph Hellwig <hch@....de>
To: John Garry <john.g.garry@...cle.com>
Cc: brauner@...nel.org, djwong@...nel.org, cem@...nel.org,
	dchinner@...hat.com, hch@....de, linux-xfs@...r.kernel.org,
	linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org,
	ojaswin@...ux.ibm.com, ritesh.list@...il.com,
	martin.petersen@...cle.com, tytso@....edu,
	linux-ext4@...r.kernel.org
Subject: Re: [PATCH v6 04/13] xfs: pass flags to xfs_reflink_allocate_cow()

On Thu, Mar 13, 2025 at 05:13:01PM +0000, John Garry wrote:
> @@ -823,6 +824,9 @@ xfs_direct_write_iomap_begin(
>  	if (xfs_is_shutdown(mp))
>  		return -EIO;
>  
> +	if (flags & IOMAP_DIRECT || IS_DAX(inode))
> +		reflink_flags |= XFS_REFLINK_CONVERT_UNWRITTEN;

Given that this is where the policy is implemented now, this comment:

	/*
	 * COW fork extents are supposed to remain unwritten until we're ready
         * to initiate a disk write.  For direct I/O we are going to write the
	 * data and need the conversion, but for buffered writes we're done.
         */        

from xfs_reflink_convert_unwritten should probably move here now.

> -	return xfs_reflink_convert_unwritten(ip, imap, cmap, convert_now);
> +	return xfs_reflink_convert_unwritten(ip, imap, cmap,
> +			flags & XFS_REFLINK_CONVERT_UNWRITTEN);

I'd probably thread the flags argument all the way through
xfs_reflink_convert_unwritten as that documents the intent better.

> +/*
> + * Flags for xfs_reflink_allocate_cow() and callees
> + */

And the full sentence with a .?