From 119e9db233ad0f4cbd4cfb9f9385a7bca378b37d Mon Sep 17 00:00:00 2001 From: Zeng Chi Date: Mon, 21 Sep 2026 18:24:42 +0800 Subject: KVM: Don't pre-reserve xarray entries when storing empty/NULL attributes Skip the xarray reservation loop when clearing all memory attributes, as storing NULL only erases the entry and never needs to allocate, so no reservation (and no cleanup of a failed one) is required in that case. Suggested-by: Sean Christopherson Cc: David Ballesteros Signed-off-by: Zeng Chi Link: https://patch.msgid.link/20260921102442.1232375-1-zeng_chi911@163.com [sean: split to separate patch] Signed-off-by: Sean Christopherson --- drivers/md/dm-vdo/permassert.h | 45 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) create mode 100644 drivers/md/dm-vdo/permassert.h (limited to 'drivers/md/dm-vdo/permassert.h') diff --git a/drivers/md/dm-vdo/permassert.h b/drivers/md/dm-vdo/permassert.h new file mode 100644 index 000000000..c34f2ba65 --- /dev/null +++ b/drivers/md/dm-vdo/permassert.h @@ -0,0 +1,45 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright 2023 Red Hat + */ + +#ifndef PERMASSERT_H +#define PERMASSERT_H + +#include + +#include "errors.h" + +/* Utilities for asserting that certain conditions are met */ + +#define STRINGIFY(X) #X + +/* + * A hack to apply the "warn if unused" attribute to an integral expression. + * + * Since GCC doesn't propagate the warn_unused_result attribute to conditional expressions + * incorporating calls to functions with that attribute, this function can be used to wrap such an + * expression. With optimization enabled, this function contributes no additional instructions, but + * the warn_unused_result attribute still applies to the code calling it. + */ +static inline int __must_check vdo_must_use(int value) +{ + return value; +} + +/* Assert that an expression is true and return an error if it is not. */ +#define VDO_ASSERT(expr, ...) vdo_must_use(__VDO_ASSERT(expr, __VA_ARGS__)) + +/* Log a message if the expression is not true. */ +#define VDO_ASSERT_LOG_ONLY(expr, ...) __VDO_ASSERT(expr, __VA_ARGS__) + +#define __VDO_ASSERT(expr, ...) \ + (likely(expr) ? VDO_SUCCESS \ + : vdo_assertion_failed(STRINGIFY(expr), __FILE__, __LINE__, __VA_ARGS__)) + +/* Log an assertion failure message. */ +int vdo_assertion_failed(const char *expression_string, const char *file_name, + int line_number, const char *format, ...) + __printf(4, 5); + +#endif /* PERMASSERT_H */ -- cgit v1.3.1