ceph: wait unsafe sync writes for evicting inode

Otherwise ceph_sync_write_unsafe() may access/modify freed inode.

Signed-off-by: Yan, Zheng <zyan@redhat.com>
diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index 50846e6..d5b9077 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -749,6 +749,7 @@
 extern struct inode *ceph_alloc_inode(struct super_block *sb);
 extern void ceph_destroy_inode(struct inode *inode);
 extern int ceph_drop_inode(struct inode *inode);
+extern void ceph_evict_inode(struct inode *inode);
 
 extern struct inode *ceph_get_inode(struct super_block *sb,
 				    struct ceph_vino vino);
@@ -927,6 +928,7 @@
 extern int ceph_release(struct inode *inode, struct file *filp);
 extern void ceph_fill_inline_data(struct inode *inode, struct page *locked_page,
 				  char *data, size_t len);
+extern void ceph_sync_write_wait(struct inode *inode);
 /* dir.c */
 extern const struct file_operations ceph_dir_fops;
 extern const struct file_operations ceph_snapdir_fops;