commit eed968607d656a218712df47a5e0432c21fd6994

Author: Daniel P. Berrange <berrange@redhat.com>

Date:   Mon Jan 16 18:11:40 2012 +0000

    hw/9pfs: Remove O_NOATIME flag from 9pfs open() calls in readonly mode

    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

    Acked-by: M. Mohan Kumar <mohan@in.ibm.com>

    Signed-off-by: Daniel P. Berrange <berrange@redhat.com>

    Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>

diff --git a/hw/9pfs/virtio-9p.c b/hw/9pfs/virtio-9p.c

index dfe2025..a72ffc3 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) {