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>

diff --git a/fs/ocfs2/inode.c b/fs/ocfs2/inode.c
index 12e5d1f733256a9c9810ba24da56a78287bc4b6a..14bf440ea4dff06c22d771bbd37ba47411c7e30c 100644 (file)
--- 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;
 }