From: "Daniel P. Berrange" <berra...@redhat.com>
When 2c74c2cb4bedddbfa67628fbd5f9273b4e0e9903 added support for
the 'readonly' flag against 9p filesystems, it also made QEMU
add the O_NOATIME flag as a side-effect.
The O_NOATIME flag, however, may only be set by the file owner,
or a user with CAP_FOWNER capability. QEMU cannot assume that
this is the case for filesytems exported to QEMU.
eg, run QEMU as non-root, and attempt to pass the host OS
filesystem through to the guest OS with readonly enable.
The result is that the guest OS cannot open any files at
all.
If O_NOATIME is really required, it should be optionally
enabled via a separate QEMU command line flag.
* hw/9pfs/virtio-9p.c: Remove O_NOATIME
Signed-off-by: Daniel P. Berrange <berra...@redhat.com>
---
hw/9pfs/virtio-9p.c | 1 -
1 files changed, 0 insertions(+), 1 deletions(-)
diff --git a/hw/9pfs/virtio-9p.c b/hw/9pfs/virtio-9p.c
index e6ba6ba..f8e2c07 100644
--- a/hw/9pfs/virtio-9p.c
+++ b/hw/9pfs/virtio-9p.c
@@ -1391,7 +1391,6 @@ static void v9fs_open(void *opaque)
err = -EROFS;
goto out;
}
- flags |= O_NOATIME;
}
err = v9fs_co_open(pdu, fidp, flags);
if (err < 0) {
--
1.7.7.5
