ext4: fix extent_status trace points

Show pblock only if it has meaningful value.

# before
   ext4:ext4_es_lookup_extent_exit: dev 253,0 ino 12 found 1 [1/4294967294) 576460752303423487 H
   ext4:ext4_es_lookup_extent_exit: dev 253,0 ino 12 found 1 [2/4294967293) 576460752303423487 HR
# after
   ext4:ext4_es_lookup_extent_exit: dev 253,0 ino 12 found 1 [1/4294967294) 0 H
   ext4:ext4_es_lookup_extent_exit: dev 253,0 ino 12 found 1 [2/4294967293) 0 HR
Signed-off-by: Dmitry Monakhov <dmonakhov@gmail.com>
Link: https://lore.kernel.org/r/20191114200147.1073-2-dmonakhov@gmail.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

fs/ext4/extents_status.h

@@ -209,6 +209,12 @@ static inline ext4_fsblk_t ext4_es_pblock(struct extent_status *es)
 	return es->es_pblk & ~ES_MASK;
 }
 
+static inline ext4_fsblk_t ext4_es_show_pblock(struct extent_status *es)
+{
+	ext4_fsblk_t pblock = ext4_es_pblock(es);
+	return pblock == ~ES_MASK ? 0 : pblock;
+}
+
 static inline void ext4_es_store_pblock(struct extent_status *es,
 					ext4_fsblk_t pb)
 {

include/trace/events/ext4.h

@@ -2282,7 +2282,7 @@ DECLARE_EVENT_CLASS(ext4__es_extent,
 		__entry->ino	= inode->i_ino;
 		__entry->lblk	= es->es_lblk;
 		__entry->len	= es->es_len;
-		__entry->pblk	= ext4_es_pblock(es);
+		__entry->pblk	= ext4_es_show_pblock(es);
 		__entry->status	= ext4_es_status(es);
 	),
 
@@ -2371,7 +2371,7 @@ TRACE_EVENT(ext4_es_find_extent_range_exit,
 		__entry->ino	= inode->i_ino;
 		__entry->lblk	= es->es_lblk;
 		__entry->len	= es->es_len;
-		__entry->pblk	= ext4_es_pblock(es);
+		__entry->pblk	= ext4_es_show_pblock(es);
 		__entry->status	= ext4_es_status(es);
 	),
 
@@ -2425,7 +2425,7 @@ TRACE_EVENT(ext4_es_lookup_extent_exit,
 		__entry->ino	= inode->i_ino;
 		__entry->lblk	= es->es_lblk;
 		__entry->len	= es->es_len;
-		__entry->pblk	= ext4_es_pblock(es);
+		__entry->pblk	= ext4_es_show_pblock(es);
 		__entry->status	= ext4_es_status(es);
 		__entry->found	= found;
 	),
@@ -2593,7 +2593,7 @@ TRACE_EVENT(ext4_es_insert_delayed_block,
 		__entry->ino		= inode->i_ino;
 		__entry->lblk		= es->es_lblk;
 		__entry->len		= es->es_len;
-		__entry->pblk		= ext4_es_pblock(es);
+		__entry->pblk		= ext4_es_show_pblock(es);
 		__entry->status		= ext4_es_status(es);
 		__entry->allocated	= allocated;
 	),