consistent treatment of EFAULT on O_DIRECT read/write
Make local filesystems treat a fault as shortened IO,
returning -EFAULT only if nothing had been transferred.
That's how everything else (NFS, FUSE, ceph, Lustre)
behaves.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/direct-io.c b/fs/direct-io.c
index 7c3ce73..fb9aa16 100644
--- a/fs/direct-io.c
+++ b/fs/direct-io.c
@@ -246,6 +246,9 @@
if ((dio->op == REQ_OP_READ) &&
((offset + transferred) > dio->i_size))
transferred = dio->i_size - offset;
+ /* ignore EFAULT if some IO has been done */
+ if (unlikely(ret == -EFAULT) && transferred)
+ ret = 0;
}
if (ret == 0)