ceph: add F_SYNC file flag to force sync (non-O_DIRECT) io

This allows us to force IO through the sync path which you normally only
get when multiple clients are reading/writing to the same file or by
mounting with -o sync.  Among other things, this lets test programs verify
correctness with a single mount.

Reviewed-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>

1 files changed, 11 insertions, 0 deletions

diff --git a/fs/ceph/ioctl.c b/fs/ceph/ioctl.c
index ef0b5f48e13a..a757a5680578 100644
--- a/fs/ceph/ioctl.c
+++ b/fs/ceph/ioctl.c
@@ -231,6 +231,14 @@ static long ceph_ioctl_lazyio(struct file *file)
         return 0;
 }
 
+static long ceph_ioctl_syncio(struct file *file)
+{
+        struct ceph_file_info *fi = file->private_data;
+
+        fi->flags |= CEPH_F_SYNC;
+        return 0;
+}
+
 long ceph_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
         dout("ioctl file %p cmd %u arg %lu\n", file, cmd, arg);
@@ -249,6 +257,9 @@ long ceph_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 
         case CEPH_IOC_LAZYIO:
                 return ceph_ioctl_lazyio(file);
+
+        case CEPH_IOC_SYNCIO:
+                return ceph_ioctl_syncio(file);
         }
 
         return -ENOTTY;