Messages in this thread |  | | | Subject | Re: [PATCH 01/10] ovl: small optimisation for ovl_lookup | | From | Miklos Szeredi <> | | Date | Mon, 06 Sep 2010 18:57:34 +0200 |
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On Mon, 06 Sep 2010, NeilBrown wrote: > If we find a non-directory in the upper layer, there is no point > performing a lookup in the lower layer as whatever is found will just > be ignored anyway. > > Signed-off-by: NeilBrown <neilb@suse.de> > --- > fs/overlayfs/overlayfs.c | 17 ++++++++--------- > 1 files changed, 8 insertions(+), 9 deletions(-) > > diff --git a/fs/overlayfs/overlayfs.c b/fs/overlayfs/overlayfs.c > index 0fe3944..0ddfeec 100644 > --- a/fs/overlayfs/overlayfs.c > +++ b/fs/overlayfs/overlayfs.c > @@ -495,7 +495,8 @@ static struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, > dput(upperdentry); > upperdentry = NULL; > ue->opaque = true; > - } > + } else if (!S_ISDIR(upperdentry->d_inode->i_mode)) > + ue->opaque = true;
Setting opaque unconditionally, without checking whether the lower file exists or not, means on unlink we'll create a whiteout even when not necessary.
Thanks, Miklos
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