On Wed, Sep 4, 2024 at 6:54 PM Yuriy Belikov <yuriybelikov1@xxxxxxxxx> wrote: > > Changes since v1: > - Provide info about trusted.overlay.metacopy extended attribute. > - Minor rephrasing regarding copy-up operation with > metacopy=on > Signed-off-by: Yuriy Belikov <yuriybelikov1@xxxxxxxxx> > --- > Documentation/filesystems/overlayfs.rst | 7 +++++-- > 1 file changed, 5 insertions(+), 2 deletions(-) > > diff --git a/Documentation/filesystems/overlayfs.rst b/Documentation/filesystems/overlayfs.rst > index 165514401441..e5ad43f4f4d7 100644 > --- a/Documentation/filesystems/overlayfs.rst > +++ b/Documentation/filesystems/overlayfs.rst > @@ -367,8 +367,11 @@ Metadata only copy up > > When the "metacopy" feature is enabled, overlayfs will only copy > up metadata (as opposed to whole file), when a metadata specific operation > -like chown/chmod is performed. Full file will be copied up later when > -file is opened for WRITE operation. > +like chown/chmod is performed. An upper file in this state is marked with > +"trusted.overlayfs.metacopy" xattr which indicates that the upper file > +contains no data. Full data will be copied up later when file is opened for > +WRITE operation. After the lower file's data is copied up, > +the "trusted.overlayfs.metacopy" xattr is removed from the upper file. > > In other words, this is delayed data copy up operation and data is copied > up when there is a need to actually modify data. > -- > 2.43.5 > Pushed to overlayfs-next with minor rephrasing of commit message. (v1 is irrelevant in the context of git history) Thanks, Amir.