ext4: fix potential NULL dereference while tracing
The allocation_context pointer can be NULL.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/include/trace/events/ext4.h b/include/trace/events/ext4.h
index f3865c7..01e9e00 100644
--- a/include/trace/events/ext4.h
+++ b/include/trace/events/ext4.h
@@ -395,11 +395,12 @@
);
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 @@
),
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_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 @@
),
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;
),