[PATCH v2 08/25] netfs: Reserve netfs_sreq_source 0 as unset/unknown

[David Howells <dhowells@redhat.com>]

Reserve the 0-valued netfs_sreq_source to mean unset or unknown so that it
can be seen in the trace as such rather than appearing as
download-from-server when it's going to get switched to something else.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
---
 include/linux/netfs.h        | 1 +
 include/trace/events/netfs.h | 1 +
 2 files changed, 2 insertions(+)

diff --git a/include/linux/netfs.h b/include/linux/netfs.h
index 11fa86640d91..16834751e646 100644
--- a/include/linux/netfs.h
+++ b/include/linux/netfs.h
@@ -43,6 +43,7 @@ static inline void folio_start_private_2(struct folio *folio)
 #define NETFS_BUF_PAGECACHE_MARK XA_MARK_1	/* - Page needs wb/dirty flag wrangling */
 
 enum netfs_io_source {
+	NETFS_SOURCE_UNKNOWN,
 	NETFS_FILL_WITH_ZEROES,
 	NETFS_DOWNLOAD_FROM_SERVER,
 	NETFS_READ_FROM_CACHE,
diff --git a/include/trace/events/netfs.h b/include/trace/events/netfs.h
index a4fd5dea52f4..f4105b8e5894 100644
--- a/include/trace/events/netfs.h
+++ b/include/trace/events/netfs.h
@@ -60,6 +60,7 @@
 	E_(netfs_rreq_trace_write_done,		"WR-DONE")
 
 #define netfs_sreq_sources					\
+	EM(NETFS_SOURCE_UNKNOWN,		"----")		\
 	EM(NETFS_FILL_WITH_ZEROES,		"ZERO")		\
 	EM(NETFS_DOWNLOAD_FROM_SERVER,		"DOWN")		\
 	EM(NETFS_READ_FROM_CACHE,		"READ")		\