md: protect against crash upon fsync on ro array

[linux-2.6-block.git] / drivers / md / md.c

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 3db3d1b271f7ef18650a227a8dd07dbc2b8fefbc..1e634a68541ee82c891fa0ad2d0a0e1c996e9839 100644 (file)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -307,6 +307,10 @@ static void md_make_request(struct request_queue *q, struct bio *bio)
                bio_io_error(bio);
                return;
        }
+       if (mddev->ro == 1 && unlikely(rw == WRITE)) {
+               bio_endio(bio, bio_sectors(bio) == 0 ? 0 : -EROFS);
+               return;
+       }
        smp_rmb(); /* Ensure implications of  'active' are visible */
        rcu_read_lock();
        if (mddev->suspended) {