ocfs2: embed actual values into ocfs2_sysfile_lock_key names

Since lockdep_set_class() uses stringified key name via macro, calling
lockdep_set_class() with an array causes lockdep warning messages to
report variable name than actual index number.

Change ocfs2_init_locked_inode() to pass actual index number for better
readability of lockdep reports.  This patch does not change behavior.

Before:

  Chain exists of:
    &ocfs2_sysfile_lock_key[args->fi_sysfile_type] --> jbd2_handle --> &oi->ip_xattr_sem

   Possible unsafe locking scenario:

         CPU0                    CPU1
         ----                    ----
    lock(&oi->ip_xattr_sem);
                                 lock(jbd2_handle);
                                 lock(&oi->ip_xattr_sem);
    lock(&ocfs2_sysfile_lock_key[args->fi_sysfile_type]);

   *** DEADLOCK ***

After:

  Chain exists of:
    &ocfs2_sysfile_lock_key[EXTENT_ALLOC_SYSTEM_INODE] --> jbd2_handle --> &oi->ip_xattr_sem

   Possible unsafe locking scenario:

         CPU0                    CPU1
         ----                    ----
    lock(&oi->ip_xattr_sem);
                                 lock(jbd2_handle);
                                 lock(&oi->ip_xattr_sem);
    lock(&ocfs2_sysfile_lock_key[EXTENT_ALLOC_SYSTEM_INODE]);

   *** DEADLOCK ***

Link: https://lkml.kernel.org/r/29348724-639c-443d-bbce-65c3a0a13a38@I-love.SAKURA.ne.jp
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Jun Piao <piaojun@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

1 files changed, 66 insertions, 4 deletions

diff --git a/fs/ocfs2/inode.c b/fs/ocfs2/inode.c
index 12e5d1f73325..14bf440ea4df 100644
--- a/fs/ocfs2/inode.c
+++ b/fs/ocfs2/inode.c
@@ -50,8 +50,6 @@ struct ocfs2_find_inode_args
 	unsigned int	fi_sysfile_type;
 };
 
-static struct lock_class_key ocfs2_sysfile_lock_key[NUM_SYSTEM_INODES];
-
 static int ocfs2_read_locked_inode(struct inode *inode,
 				   struct ocfs2_find_inode_args *args);
 static int ocfs2_init_locked_inode(struct inode *inode, void *opaque);
@@ -250,14 +248,77 @@ bail:
 static int ocfs2_init_locked_inode(struct inode *inode, void *opaque)
 {
 	struct ocfs2_find_inode_args *args = opaque;
+#ifdef CONFIG_LOCKDEP
+	static struct lock_class_key ocfs2_sysfile_lock_key[NUM_SYSTEM_INODES];
 	static struct lock_class_key ocfs2_quota_ip_alloc_sem_key,
 				     ocfs2_file_ip_alloc_sem_key;
+#endif
 
 	inode->i_ino = args->fi_ino;
 	OCFS2_I(inode)->ip_blkno = args->fi_blkno;
-	if (args->fi_sysfile_type != 0)
+#ifdef CONFIG_LOCKDEP
+	switch (args->fi_sysfile_type) {
+	case BAD_BLOCK_SYSTEM_INODE:
+		break;
+	case GLOBAL_INODE_ALLOC_SYSTEM_INODE:
+		lockdep_set_class(&inode->i_rwsem,
+				  &ocfs2_sysfile_lock_key[GLOBAL_INODE_ALLOC_SYSTEM_INODE]);
+		break;
+	case SLOT_MAP_SYSTEM_INODE:
+		lockdep_set_class(&inode->i_rwsem,
+				  &ocfs2_sysfile_lock_key[SLOT_MAP_SYSTEM_INODE]);
+		break;
+	case HEARTBEAT_SYSTEM_INODE:
+		lockdep_set_class(&inode->i_rwsem,
+				  &ocfs2_sysfile_lock_key[HEARTBEAT_SYSTEM_INODE]);
+		break;
+	case GLOBAL_BITMAP_SYSTEM_INODE:
+		lockdep_set_class(&inode->i_rwsem,
+				  &ocfs2_sysfile_lock_key[GLOBAL_BITMAP_SYSTEM_INODE]);
+		break;
+	case USER_QUOTA_SYSTEM_INODE:
+		lockdep_set_class(&inode->i_rwsem,
+				  &ocfs2_sysfile_lock_key[USER_QUOTA_SYSTEM_INODE]);
+		break;
+	case GROUP_QUOTA_SYSTEM_INODE:
+		lockdep_set_class(&inode->i_rwsem,
+				  &ocfs2_sysfile_lock_key[GROUP_QUOTA_SYSTEM_INODE]);
+		break;
+	case ORPHAN_DIR_SYSTEM_INODE:
+		lockdep_set_class(&inode->i_rwsem,
+				  &ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE]);
+		break;
+	case EXTENT_ALLOC_SYSTEM_INODE:
 		lockdep_set_class(&inode->i_rwsem,
-			&ocfs2_sysfile_lock_key[args->fi_sysfile_type]);
+				  &ocfs2_sysfile_lock_key[EXTENT_ALLOC_SYSTEM_INODE]);
+		break;
+	case INODE_ALLOC_SYSTEM_INODE:
+		lockdep_set_class(&inode->i_rwsem,
+				  &ocfs2_sysfile_lock_key[INODE_ALLOC_SYSTEM_INODE]);
+		break;
+	case JOURNAL_SYSTEM_INODE:
+		lockdep_set_class(&inode->i_rwsem,
+				  &ocfs2_sysfile_lock_key[JOURNAL_SYSTEM_INODE]);
+		break;
+	case LOCAL_ALLOC_SYSTEM_INODE:
+		lockdep_set_class(&inode->i_rwsem,
+				  &ocfs2_sysfile_lock_key[LOCAL_ALLOC_SYSTEM_INODE]);
+		break;
+	case TRUNCATE_LOG_SYSTEM_INODE:
+		lockdep_set_class(&inode->i_rwsem,
+				  &ocfs2_sysfile_lock_key[TRUNCATE_LOG_SYSTEM_INODE]);
+		break;
+	case LOCAL_USER_QUOTA_SYSTEM_INODE:
+		lockdep_set_class(&inode->i_rwsem,
+				  &ocfs2_sysfile_lock_key[LOCAL_USER_QUOTA_SYSTEM_INODE]);
+		break;
+	case LOCAL_GROUP_QUOTA_SYSTEM_INODE:
+		lockdep_set_class(&inode->i_rwsem,
+				  &ocfs2_sysfile_lock_key[LOCAL_GROUP_QUOTA_SYSTEM_INODE]);
+		break;
+	default:
+		WARN_ONCE(1, "Unknown sysfile type %d\n", args->fi_sysfile_type);
+	}
 	if (args->fi_sysfile_type == USER_QUOTA_SYSTEM_INODE ||
 	    args->fi_sysfile_type == GROUP_QUOTA_SYSTEM_INODE ||
 	    args->fi_sysfile_type == LOCAL_USER_QUOTA_SYSTEM_INODE ||
@@ -267,6 +328,7 @@ static int ocfs2_init_locked_inode(struct inode *inode, void *opaque)
 	else
 		lockdep_set_class(&OCFS2_I(inode)->ip_alloc_sem,
 				  &ocfs2_file_ip_alloc_sem_key);
+#endif
 
 	return 0;
 }