Commit 0c954c57 authored by Tetsuo Handa's avatar Tetsuo Handa Committed by Andrew Morton
Browse files

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: default avatarTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: default avatarJoseph 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: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 01bda058

fs/ocfs2/inode.c

+66 −4
Original line number Diff line number Diff line
@@ -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 @@ static int ocfs2_find_actor(struct inode *inode, void *opaque) 
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[args->fi_sysfile_type]);

				  &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[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;

}