f2fs: fix to wait dio completion

commit 96cfeb0389530ae32ade8a48ae3ae1ac3b6c009d upstream.

It should wait all existing dio write IOs before block removal,
otherwise, previous direct write IO may overwrite data in the
block which may be reused by other inode.

Cc: [email protected]
Signed-off-by: Chao Yu <[email protected]>
Signed-off-by: Jaegeuk Kim <[email protected]>
Signed-off-by: Alva Lan <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: chaseyu

fs/f2fs/file.c

@@ -1048,6 +1048,13 @@ int f2fs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 				return err;
 		}
 
+		/*
+		 * wait for inflight dio, blocks should be removed after
+		 * IO completion.
+		 */
+		if (attr->ia_size < old_size)
+			inode_dio_wait(inode);
+
 		f2fs_down_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
 		filemap_invalidate_lock(inode->i_mapping);
 
@@ -1880,6 +1887,12 @@ static long f2fs_fallocate(struct file *file, int mode,
 	if (ret)
 		goto out;
 
+	/*
+	 * wait for inflight dio, blocks should be removed after IO
+	 * completion.
+	 */
+	inode_dio_wait(inode);
+
 	if (mode & FALLOC_FL_PUNCH_HOLE) {
 		if (offset >= inode->i_size)
 			goto out;