ext4: fix potential NULL dereference while tracing

[net-next-2.6.git] / include / trace / events / ext4.h

diff --git a/include/trace/events/ext4.h b/include/trace/events/ext4.h
index f3865c7b4166e315da77d9c342b977b9d4338915..01e9e0076a92c68682fa513e1f4a862e291fb9ae 100644 (file)
--- a/include/trace/events/ext4.h
+++ b/include/trace/events/ext4.h
@@ -395,11 +395,12 @@ DEFINE_EVENT(ext4__mb_new_pa, ext4_mb_new_group_pa,
 );
 
 TRACE_EVENT(ext4_mb_release_inode_pa,
-       TP_PROTO(struct ext4_allocation_context *ac,
+       TP_PROTO(struct super_block *sb,
+                struct ext4_allocation_context *ac,
                 struct ext4_prealloc_space *pa,
                 unsigned long long block, unsigned int count),
 
-       TP_ARGS(ac, pa, block, count),
+       TP_ARGS(sb, ac, pa, block, count),
 
        TP_STRUCT__entry(
                __field(        dev_t,  dev                     )
@@ -410,8 +411,9 @@ TRACE_EVENT(ext4_mb_release_inode_pa,
        ),
 
        TP_fast_assign(
-               __entry->dev            = ac->ac_sb->s_dev;
-               __entry->ino            = ac->ac_inode->i_ino;
+               __entry->dev            = sb->s_dev;
+               __entry->ino            = (ac && ac->ac_inode) ? 
+                                               ac->ac_inode->i_ino : 0;
                __entry->block          = block;
                __entry->count          = count;
        ),
@@ -422,10 +424,11 @@ TRACE_EVENT(ext4_mb_release_inode_pa,
 );
 
 TRACE_EVENT(ext4_mb_release_group_pa,
-       TP_PROTO(struct ext4_allocation_context *ac,
+       TP_PROTO(struct super_block *sb,
+                struct ext4_allocation_context *ac,
                 struct ext4_prealloc_space *pa),
 
-       TP_ARGS(ac, pa),
+       TP_ARGS(sb, ac, pa),
 
        TP_STRUCT__entry(
                __field(        dev_t,  dev                     )
@@ -436,8 +439,9 @@ TRACE_EVENT(ext4_mb_release_group_pa,
        ),
 
        TP_fast_assign(
-               __entry->dev            = ac->ac_sb->s_dev;
-               __entry->ino            = ac->ac_inode->i_ino;
+               __entry->dev            = sb->s_dev;
+               __entry->ino            = (ac && ac->ac_inode) ?
+                                               ac->ac_inode->i_ino : 0;
                __entry->pa_pstart      = pa->pa_pstart;
                __entry->pa_len         = pa->pa_len;
        ),