Re: [PATCH 2/2] xfs: shortcut xfs_file_release for read-only file descriptors

[Brian Foster <bfoster@redhat.com>]

On Mon, Sep 16, 2019 at 02:20:41PM +0200, Christoph Hellwig wrote:
> xfs_file_release currently performs flushing of truncated blocks and
> freeing of the post-EOF speculative preallocation for all file
> descriptors as long as they are not on a read-only mount.  Switch to
> check for FMODE_WRITE instead as we should only perform these actions
> on writable file descriptors, and no such file descriptors can be
> created on a read-only mount.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  fs/xfs/xfs_file.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
> index 72680edf2ceb..06f0eb25c7cc 100644
> --- a/fs/xfs/xfs_file.c
> +++ b/fs/xfs/xfs_file.c
> @@ -1066,7 +1066,7 @@ xfs_file_release(
>  	struct xfs_inode	*ip = XFS_I(inode);
>  	struct xfs_mount	*mp = ip->i_mount;
>  
> -	if (mp->m_flags & XFS_MOUNT_RDONLY)
> +	if (!(file->f_mode & FMODE_WRITE))
>  		return 0;
>  	

Didn't Dave have a variant of this patch for dealing with a
fragmentation issue (IIRC)? Anyways, seems fine:

Reviewed-by: Brian Foster <bfoster@redhat.com>

>  	if (XFS_FORCED_SHUTDOWN(mp))
> -- 
> 2.20.1
>