From: Joseph Qi <[email protected]> Subject: ocfs2: fix BUG in ocfs2_downconvert_thread_do_work()
BUG_ON(list_empty(&osb->blocked_lock_list)) in ocfs2_downconvert_thread_do_work can be triggered in the following case: ocfs2dc has firstly saved osb->blocked_lock_count to local varibale processed, and then processes the dentry lockres. During the dentry put, it calls iput and then deletes rw, inode and open lockres from blocked list in ocfs2_mark_lockres_freeing. And this causes the variable `processed' to not reflect the number of blocked lockres to be processed, which triggers the BUG. Signed-off-by: Joseph Qi <[email protected]> Cc: Mark Fasheh <[email protected]> Cc: Joel Becker <[email protected]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]> --- fs/ocfs2/dlmglue.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff -puN fs/ocfs2/dlmglue.c~ocfs2-fix-bug-in-ocfs2_downconvert_thread_do_work fs/ocfs2/dlmglue.c --- a/fs/ocfs2/dlmglue.c~ocfs2-fix-bug-in-ocfs2_downconvert_thread_do_work +++ a/fs/ocfs2/dlmglue.c @@ -4025,9 +4025,13 @@ static void ocfs2_downconvert_thread_do_ osb->dc_work_sequence = osb->dc_wake_sequence; processed = osb->blocked_lock_count; - while (processed) { - BUG_ON(list_empty(&osb->blocked_lock_list)); - + /* + * blocked lock processing in this loop might call iput which can + * remove items off osb->blocked_lock_list. Downconvert up to + * 'processed' number of locks, but stop short if we had some + * removed in ocfs2_mark_lockres_freeing when downconverting. + */ + while (processed && !list_empty(&osb->blocked_lock_list)) { lockres = list_entry(osb->blocked_lock_list.next, struct ocfs2_lock_res, l_blocked_list); list_del_init(&lockres->l_blocked_list); _ -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
