[PATCH v2 001/110] vfs: introduce kino_t typedef and PRIino format macro

Introduce a kino_t typedef and PRIino format macro to enable a
bisect-clean transition of i_ino from unsigned long to u64.

kino_t is initially defined as unsigned long (matching the original
i_ino type), and PRIino is "l" (the format length modifier for
unsigned long). A later patch will change these to u64 and "ll"
respectively once all format strings have been updated to use PRIino.

The PRIino macro is a length modifier, not a complete format specifier.
It is used as: "%" PRIino "u" for decimal, "%" PRIino "x" for hex, etc.
This follows the pattern used by userspace PRIu64/PRIx64 macros.

Format strings using i_ino should be updated to use PRIino instead of
a hard-coded length modifier to ensure warning-free compilation on
both 32-bit and 64-bit architectures throughout the transition.

Signed-off-by: Jeff Layton <[email protected]>
---
 include/linux/fs.h | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 8b3dd145b25ec12b00ac1df17a952d9116b88047..e38bc5ece1f360d679a8f30b8171292f7a65c218 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -758,6 +758,9 @@ struct inode_state_flags {
 	enum inode_state_flags_enum __state;
 };
 
+typedef unsigned long	kino_t;
+#define PRIino		"l"
+
 /*
  * Keep mostly read-only and often accessed (especially for
  * the RCU path lookup and 'stat' data) fields at the beginning
@@ -783,7 +786,7 @@ struct inode {
 #endif
 
 	/* Stat data, not accessed from path walking */
-	unsigned long		i_ino;
+	kino_t			i_ino;
 	/*
 	 * Filesystems may only read i_nlink directly.  They shall use the
 	 * following functions for modification:

-- 
2.53.0