diff mbox series

netfs: Fix the netfs_folio tracepoint to handle NULL mapping

Message ID 20241002092343.823-1-exkc@exkc.moe (mailing list archive)
State New
Headers show
Series netfs: Fix the netfs_folio tracepoint to handle NULL mapping | expand

Commit Message

exkc Oct. 2, 2024, 9:23 a.m. UTC 
From: David Howells <dhowells@redhat.com>

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@redhat.com>
Link: https://lore.kernel.org/r/2917423.1727697556@warthog.procyon.org.uk
cc: Jeff Layton <jlayton@kernel.org>
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
---
 include/trace/events/netfs.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
diff mbox series

Patch

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);