From 43b10a20372d9a1c08391f33f1c8bd86179ddc5f Mon Sep 17 00:00:00 2001 From: jiangyiwen Date: Thu, 3 Apr 2014 14:47:13 -0700 Subject: ocfs2: avoid system inode ref confusion by adding mutex lock The following case may lead to the same system inode ref in confusion. A thread B thread ocfs2_get_system_file_inode ->get_local_system_inode ->_ocfs2_get_system_file_inode because of *arr == NULL, ocfs2_get_system_file_inode ->get_local_system_inode ->_ocfs2_get_system_file_inode gets first ref thru _ocfs2_get_system_file_inode, gets second ref thru igrab and set *arr = inode at the moment, B thread also gets two refs, so lead to one more inode ref. So add mutex lock to avoid multi thread set two inode ref once at the same time. Signed-off-by: jiangyiwen Reviewed-by: Joseph Qi Cc: Joel Becker Cc: Mark Fasheh Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ocfs2/ocfs2.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'fs/ocfs2/ocfs2.h') diff --git a/fs/ocfs2/ocfs2.h b/fs/ocfs2/ocfs2.h index a780e20d4fba..8d64a97a9d5e 100644 --- a/fs/ocfs2/ocfs2.h +++ b/fs/ocfs2/ocfs2.h @@ -446,6 +446,8 @@ struct ocfs2_super /* rb tree root for refcount lock. */ struct rb_root osb_rf_lock_tree; struct ocfs2_refcount_tree *osb_ref_tree_lru; + + struct mutex system_file_mutex; }; #define OCFS2_SB(sb) ((struct ocfs2_super *)(sb)->s_fs_info) -- cgit v1.2.3