On Thu, Mar 14, 2019 at 02:29:00PM -0700, Darrick J. Wong wrote: > From: Darrick J. Wong <darrick.wong@xxxxxxxxxx> > > Certain workloads fragment files on XFS very badly, such as a software > package that creates a number of threads, each of which repeatedly run > the sequence: open a file, perform a synchronous write, and close the > file, which defeats the speculative preallocation mechanism. We work > around this problem by only deleting posteof blocks the /first/ time a > file is closed to preserve the behavior that unpacking a tarball lays > out files one after the other with no gaps. > > Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx> > --- > fs/xfs/xfs_inode.c | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > > diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c > index 665fb2518a66..981c34bdec25 100644 > --- a/fs/xfs/xfs_inode.c > +++ b/fs/xfs/xfs_inode.c > @@ -1262,9 +1262,7 @@ xfs_release( > return error; > } > > - /* delalloc blocks after truncation means it really is dirty */ > - if (ip->i_delayed_blks) > - xfs_iflags_set(ip, XFS_IDIRTY_RELEASE); > + xfs_iflags_set(ip, XFS_IDIRTY_RELEASE); I've been meaning to test this exact setup to see what the impact is, but haven't got to it yet. I can't really comment on it sanely until I see what it does to various workloads.... We do need more than this though. e.g we need to skip the block freeing compeltely on O_RDONLY file closes... Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx
