| From | Amir Goldstein <> | Date | Fri, 10 Sep 2021 08:35:41 +0300 | Subject | Re: [PATCH AUTOSEL 5.14 46/99] ovl: copy up sync/noatime fileattr flags |
| |
On Fri, Sep 10, 2021 at 3:17 AM Sasha Levin <sashal@kernel.org> wrote: > > From: Amir Goldstein <amir73il@gmail.com> > > [ Upstream commit 72db82115d2bdfbfba8b15a92d91872cfe1b40c6 ] > > When a lower file has sync/noatime fileattr flags, the behavior of > overlayfs post copy up is inconsistent. > > Immediately after copy up, ovl inode still has the S_SYNC/S_NOATIME > inode flags copied from lower inode, so vfs code still treats the ovl > inode as sync/noatime. After ovl inode evict or mount cycle, > the ovl inode does not have these inode flags anymore. > > To fix this inconsistency, try to copy the fileattr flags on copy up > if the upper fs supports the fileattr_set() method. > > This gives consistent behavior post copy up regardless of inode eviction > from cache. > > We cannot copy up the immutable/append-only inode flags in a similar > manner, because immutable/append-only inodes cannot be linked and because > overlayfs will not be able to set overlay.* xattr on the upper inodes. > > Those flags will be addressed by a followup patch. > > Signed-off-by: Amir Goldstein <amir73il@gmail.com> > Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> > Signed-off-by: Sasha Levin <sashal@kernel.org> > ---
Sasha,
I do not recommend applying this patch to stable. The value/risk ratio is not worth it IMO.
I don't know of anyone who ever complained about not copying the NOATIME/SYNC fileattrs specifically.
This patch is more of a complimentary patch to the IMMUTABLE/ APPEND fileattr patch, which is not appropriate for stable either.
OTOH, ovl-update-5.15 has this patch that was not included in the AUTOSEL batch, even though it has a Fixes tag, CC stable and very strong hints in the subject: 52d5a0c6bd8a ("ovl: fix BUG_ON() in may_delete() when called from ovl_cleanup()")
I suppose AUTOSEL leaves these sorts of patches to Greg's scripts?
Thanks, Amir.
|