[PATCH 1/3] fault-inject: improve build for CONFIG_FAULT_INJECTION=n

[Ghimiray, Himal Prasad]

On 13-08-2024 17:42, Jani Nikula wrote:
> The fault-inject.h users across the kernel need to add a lot of #ifdef
> CONFIG_FAULT_INJECTION to cater for shortcomings in the header. Make
> fault-inject.h self-contained for CONFIG_FAULT_INJECTION=n, and add
> stubs for DECLARE_FAULT_ATTR(), setup_fault_attr(), should_fail_ex(),
> and should_fail() to allow removal of conditional compilation.

Would a "Fixes" tag be appropriate here?
Fixes: 6ff1cb355e62 ("[PATCH] fault-injection capabilities infrastructure")

> 
> Cc: Akinobu Mita <akinobu.mita at gmail.com>
> Cc: Andrew Morton <akpm at linux-foundation.org>
> Signed-off-by: Jani Nikula <jani.nikula at intel.com>
> ---
>   include/linux/fault-inject.h | 36 +++++++++++++++++++++++++++++-------
>   1 file changed, 29 insertions(+), 7 deletions(-)
> 
> diff --git a/include/linux/fault-inject.h b/include/linux/fault-inject.h
> index 354413950d34..8c829d28dcf3 100644
> --- a/include/linux/fault-inject.h
> +++ b/include/linux/fault-inject.h
> @@ -2,13 +2,17 @@
>   #ifndef _LINUX_FAULT_INJECT_H
>   #define _LINUX_FAULT_INJECT_H
>   
> +#include <linux/err.h>
> +#include <linux/types.h>
> +
> +struct dentry;
> +struct kmem_cache;
> +
>   #ifdef CONFIG_FAULT_INJECTION
>   
> -#include <linux/types.h>
> -#include <linux/debugfs.h>
> +#include <linux/atomic.h>
>   #include <linux/configfs.h>
>   #include <linux/ratelimit.h>
> -#include <linux/atomic.h>
>   
>   /*
>    * For explanation of the elements of this struct, see
> @@ -51,6 +55,28 @@ int setup_fault_attr(struct fault_attr *attr, char *str);
>   bool should_fail_ex(struct fault_attr *attr, ssize_t size, int flags);
>   bool should_fail(struct fault_attr *attr, ssize_t size);
>   
> +#else /* CONFIG_FAULT_INJECTION */
> +
> +struct fault_attr {
> +};
> +
> +#define DECLARE_FAULT_ATTR(name) struct fault_attr name = {}
> +
> +static inline int setup_fault_attr(struct fault_attr *attr, char *str)
> +{
> +	return 0; /* Note: 0 means error for __setup() handlers! */
> +}
> +static inline bool should_fail_ex(struct fault_attr *attr, ssize_t size, int flags)
> +{
> +	return false;
> +}
> +static inline bool should_fail(struct fault_attr *attr, ssize_t size)
> +{
> +	return false;
> +}
> +
> +#endif /* CONFIG_FAULT_INJECTION */
> +
>   #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
>   
>   struct dentry *fault_create_debugfs_attr(const char *name,
> @@ -87,10 +113,6 @@ static inline void fault_config_init(struct fault_config *config,
>   
>   #endif /* CONFIG_FAULT_INJECTION_CONFIGFS */
>   
> -#endif /* CONFIG_FAULT_INJECTION */
> -
> -struct kmem_cache;
> -
>   #ifdef CONFIG_FAIL_PAGE_ALLOC
>   bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order);
>   #else