44 lines
1.7 KiB
Diff
44 lines
1.7 KiB
Diff
commit cdc3e7eeafa9f683214d2c15d52ef384c3de6611
|
|
Author: aszlig <aszlig@nix.build>
|
|
Date: Mon Mar 18 13:21:01 2019 +0100
|
|
|
|
9pfs: Ignore O_NOATIME open flag
|
|
|
|
Since Linux 4.19, overlayfs uses the O_NOATIME flag on its lowerdir,
|
|
which in turn causes errors when the Nix store is mounted in the guest
|
|
because the file owner of the store paths typically don't match the
|
|
owner of the QEMU process.
|
|
|
|
After submitting a patch to the overlayfs mailing list[1], it turns out
|
|
that my patch was incomplete[2] and needs a bit more rework.
|
|
|
|
So instead of using an incomplete kernel patch in nixpkgs, which affects
|
|
*all* users of overlayfs, not just NixOS VM tests, I decided that for
|
|
now it's better to patch QEMU instead.
|
|
|
|
The change here really only ignores the O_NOATIME flag so that the
|
|
behaviour is similar to what NFS does. From open(2):
|
|
|
|
This flag may not be effective on all filesystems. One example is NFS,
|
|
where the server maintains the access time.
|
|
|
|
This change is therefore only temporary until the final fix lands in the
|
|
stable kernel releases.
|
|
|
|
[1]: https://www.spinics.net/lists/linux-unionfs/msg06755.html
|
|
[2]: https://www.spinics.net/lists/linux-unionfs/msg06756.html
|
|
|
|
Signed-off-by: aszlig <aszlig@nix.build>
|
|
|
|
diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c
|
|
index 55821343e5..0b8425fe18 100644
|
|
--- a/hw/9pfs/9p.c
|
|
+++ b/hw/9pfs/9p.c
|
|
@@ -127,7 +127,6 @@ static int dotl_to_open_flags(int flags)
|
|
{ P9_DOTL_LARGEFILE, O_LARGEFILE },
|
|
{ P9_DOTL_DIRECTORY, O_DIRECTORY },
|
|
{ P9_DOTL_NOFOLLOW, O_NOFOLLOW },
|
|
- { P9_DOTL_NOATIME, O_NOATIME },
|
|
{ P9_DOTL_SYNC, O_SYNC },
|
|
};
|
|
|