[RFC PATCH v2 1/3] error-injection: Introduce EI_ETYPE_FALSE for fail_function

Introduce EI_ETYPE_FALSE for functions which need false as return
value in their error-injections, like btrfs_data_csum_ok.

EI_ETYPE_NULL can return 0 too but its readability is not good
enough.

Signed-off-by: Song Chen <[email protected]>
---
 include/asm-generic/error-injection.h | 1 +
 kernel/fail_function.c                | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/include/asm-generic/error-injection.h b/include/asm-generic/error-injection.h
index b05253f68eaa..6c399121ab7a 100644
--- a/include/asm-generic/error-injection.h
+++ b/include/asm-generic/error-injection.h
@@ -8,6 +8,7 @@ enum {
 	EI_ETYPE_ERRNO,		/* Return -ERRNO if failure */
 	EI_ETYPE_ERRNO_NULL,	/* Return -ERRNO or NULL if failure */
 	EI_ETYPE_TRUE,		/* Return true if failure */
+	EI_ETYPE_FALSE,		/* Return false if failure */
 };
 
 struct error_injection_entry {
diff --git a/kernel/fail_function.c b/kernel/fail_function.c
index 2eaf55005f49..90cdad0412cd 100644
--- a/kernel/fail_function.c
+++ b/kernel/fail_function.c
@@ -48,6 +48,8 @@ static unsigned long adjust_error_retval(unsigned long addr, unsigned long retv)
 		break;
 	case EI_ETYPE_TRUE:
 		return 1;
+	case EI_ETYPE_FALSE:
+		return 0;
 	}
 
 	return retv;
-- 
2.43.0