[PATCH 1/2] loop: use filp_close() rather than fput()

[NeilBrown]

When a loop device is being shutdown the backing file is
closed with fput().  This is different from how close(2)
closes files - it uses filp_close().

The difference is important for filesystems which provide a ->flush
file operation such as NFS.  NFS assumes a flush will always
be called on last close, and gets confused otherwise.

Signed-off-by: NeilBrown <ne...@suse.com>
---
 drivers/block/loop.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index ebbd0c3fe0ed..9c457ca6c55e 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -682,7 +682,7 @@ static int loop_change_fd(struct loop_device *lo, struct 
block_device *bdev,
        if (error)
                goto out_putf;
 
-       fput(old_file);
+       filp_close(old_file, NULL);
        if (lo->lo_flags & LO_FLAGS_PARTSCAN)
                loop_reread_partitions(lo, bdev);
        return 0;
@@ -1071,12 +1071,12 @@ static int loop_clr_fd(struct loop_device *lo)
        loop_unprepare_queue(lo);
        mutex_unlock(&lo->lo_ctl_mutex);
        /*
-        * Need not hold lo_ctl_mutex to fput backing file.
+        * Need not hold lo_ctl_mutex to close backing file.
         * Calling fput holding lo_ctl_mutex triggers a circular
         * lock dependency possibility warning as fput can take
         * bd_mutex which is usually taken before lo_ctl_mutex.
         */
-       fput(filp);
+       filp_close(filp, NULL);
        return 0;
 }