writeback: enforce s_umount locking in writeback_inodes_sb
Make sure that not only sync_filesystem but all callers of writeback_inodes_sb
have the superblock protected against remount. As-is this disables all
functionality for these callers, but the next patch relies on this locking to
fix writeback_inodes_sb for sync_filesystem.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
diff --git a/fs/ubifs/budget.c b/fs/ubifs/budget.c
index 076ca50..c8ff0d1 100644
--- a/fs/ubifs/budget.c
+++ b/fs/ubifs/budget.c
@@ -62,7 +62,9 @@
*/
static void shrink_liability(struct ubifs_info *c, int nr_to_write)
{
+ down_read(&c->vfs_sb->s_umount);
writeback_inodes_sb(c->vfs_sb);
+ up_read(&c->vfs_sb->s_umount);
}
/**