From: David Howells <dhowells@xxxxxxxxxx>
Fix the netfs_folio tracepoint to handle folios that have a NULL mapping
pointer. In such a case, just substitute a zero inode number.
Fixes: c38f4e96e605 ("netfs: Provide func to copy data to pagecache for buffered write")
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
Link: https://lore.kernel.org/r/2917423.1727697556@xxxxxxxxxxxxxxxxxxxxxx
cc: Jeff Layton <jlayton@xxxxxxxxxx>
cc: netfs@xxxxxxxxxxxxxxx
cc: linux-fsdevel@xxxxxxxxxxxxxxx
Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx>
---
include/trace/events/netfs.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/include/trace/events/netfs.h b/include/trace/events/netfs.h
index 76bd42a96815..1d7c52821e55 100644
--- a/include/trace/events/netfs.h
+++ b/include/trace/events/netfs.h
@@ -448,7 +448,8 @@ TRACE_EVENT(netfs_folio,
),
TP_fast_assign(
- __entry->ino = folio->mapping->host->i_ino;
+ struct address_space *__m = READ_ONCE(folio->mapping);
+ __entry->ino = __m ? __m->host->i_ino : 0;
__entry->why = why;
__entry->index = folio_index(folio);
__entry->nr = folio_nr_pages(folio);
--
2.46.1
