md: remove clumsy usage of do_sync_mapping_range from bitmap code

and replace with vfs_fsync which is much neater (but wasn't exported,
or even in existence at the time the code was written).

Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NeilBrown <neilb@suse.de>

diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index 6986b00..60e2b32 100644 (file)
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -1624,10 +1624,11 @@ int bitmap_create(mddev_t *mddev)
        bitmap->offset = mddev->bitmap_offset;
        if (file) {
                get_file(file);
-               do_sync_mapping_range(file->f_mapping, 0, LLONG_MAX,
-                                     SYNC_FILE_RANGE_WAIT_BEFORE |
-                                     SYNC_FILE_RANGE_WRITE |
-                                     SYNC_FILE_RANGE_WAIT_AFTER);
+               /* As future accesses to this file will use bmap,
+                * and bypass the page cache, we must sync the file
+                * first.
+                */
+               vfs_fsync(file, file->f_dentry, 1);
        }
        /* read superblock from bitmap file (this sets bitmap->chunksize) */
        err = bitmap_read_sb(bitmap);