On Wed, Sep 14, 2016 at 2:43 PM, Amir Goldstein <amir73il@xxxxxxxxx> wrote: > When copying up within the same fs, try to use vfs_clone_file_range(). > This is very efficient when lower and upper are on the same fs > with file reflink support. If vfs_clone_file_range() fails because > lower and upper are not on the same fs or if fs has no reflink support, > copy up falls back to the regular data copy code. > > Tested correct behavior when lower and upper are on: > 1. same ext4 (copy) > 2. same xfs + reflink patches + mkfs.xfs (copy) > 3. same xfs + reflink patches + mkfs.xfs -m reflink=1 (reflink) > 4. different xfs + reflink patches + mkfs.xfs -m reflink=1 (copy) > > For comparison, on my laptop, xfstest overlay/001 (copy up of large > sparse files) takes less than 1 second in the xfs reflink setup vs. > 25 seconds on the rest of the setups. > > Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx> > --- > fs/overlayfs/copy_up.c | 12 +++++++++++- > 1 file changed, 11 insertions(+), 1 deletion(-) > > diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c > index 43fdc27..ba039f8 100644 > --- a/fs/overlayfs/copy_up.c > +++ b/fs/overlayfs/copy_up.c > @@ -136,6 +136,16 @@ static int ovl_copy_up_data(struct path *old, struct path *new, loff_t len) > goto out_fput; > } > > + /* Try to use clone_file_range to clone up within the same fs */ > + error = vfs_clone_file_range(old_file, 0, new_file, 0, len); > + if (!error) > + goto out; > + /* If we can clone but clone failed - abort */ > + if (error != -EXDEV && error != -EOPNOTSUPP) > + goto out; Would be safer to fall back on any error. Otherwise ACK. Thanks, Miklos -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
