From: Mateusz Guzik <mjguzik@gmail.com>
To: brauner@kernel.org
Cc: viro@zeniv.linux.org.uk, jack@suse.cz,
linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
Mateusz Guzik <mjguzik@gmail.com>
Subject: [PATCH v4 1/3] vfs: add initial support for CONFIG_DEBUG_VFS
Date: Sun, 9 Feb 2025 19:55:20 +0100 [thread overview]
Message-ID: <20250209185523.745956-2-mjguzik@gmail.com> (raw)
In-Reply-To: <20250209185523.745956-1-mjguzik@gmail.com>
Small collection of macros taken from mmdebug.h
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
---
fs/inode.c | 15 ++++++++++++++
include/linux/fs.h | 1 +
include/linux/vfsdebug.h | 45 ++++++++++++++++++++++++++++++++++++++++
lib/Kconfig.debug | 9 ++++++++
4 files changed, 70 insertions(+)
create mode 100644 include/linux/vfsdebug.h
diff --git a/fs/inode.c b/fs/inode.c
index 5587aabdaa5e..875e66261f06 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -2953,3 +2953,18 @@ umode_t mode_strip_sgid(struct mnt_idmap *idmap,
return mode & ~S_ISGID;
}
EXPORT_SYMBOL(mode_strip_sgid);
+
+#ifdef CONFIG_DEBUG_VFS
+/*
+ * Dump an inode.
+ *
+ * TODO: add a proper inode dumping routine, this is a stub to get debug off the
+ * ground.
+ */
+void dump_inode(struct inode *inode, const char *reason)
+{
+ pr_warn("%s encountered for inode %px", reason, inode);
+}
+
+EXPORT_SYMBOL(dump_inode);
+#endif
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 1437a3323731..034745af9702 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2,6 +2,7 @@
#ifndef _LINUX_FS_H
#define _LINUX_FS_H
+#include <linux/vfsdebug.h>
#include <linux/linkage.h>
#include <linux/wait_bit.h>
#include <linux/kdev_t.h>
diff --git a/include/linux/vfsdebug.h b/include/linux/vfsdebug.h
new file mode 100644
index 000000000000..9cf22d3eb9dd
--- /dev/null
+++ b/include/linux/vfsdebug.h
@@ -0,0 +1,45 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef LINUX_VFS_DEBUG_H
+#define LINUX_VFS_DEBUG_H 1
+
+#include <linux/bug.h>
+
+struct inode;
+
+#ifdef CONFIG_DEBUG_VFS
+void dump_inode(struct inode *inode, const char *reason);
+
+#define VFS_BUG_ON(cond) BUG_ON(cond)
+#define VFS_WARN_ON(cond) (void)WARN_ON(cond)
+#define VFS_WARN_ON_ONCE(cond) (void)WARN_ON_ONCE(cond)
+#define VFS_WARN_ONCE(cond, format...) (void)WARN_ONCE(cond, format)
+#define VFS_WARN(cond, format...) (void)WARN(cond, format)
+
+#define VFS_BUG_ON_INODE(cond, inode) ({ \
+ if (unlikely(!!(cond))) { \
+ dump_inode(inode, "VFS_BUG_ON_INODE(" #cond")");\
+ BUG_ON(1); \
+ } \
+})
+
+#define VFS_WARN_ON_INODE(cond, inode) ({ \
+ int __ret_warn = !!(cond); \
+ \
+ if (unlikely(__ret_warn)) { \
+ dump_inode(inode, "VFS_WARN_ON_INODE(" #cond")");\
+ WARN_ON(1); \
+ } \
+ unlikely(__ret_warn); \
+})
+#else
+#define VFS_BUG_ON(cond) BUILD_BUG_ON_INVALID(cond)
+#define VFS_WARN_ON(cond) BUILD_BUG_ON_INVALID(cond)
+#define VFS_WARN_ON_ONCE(cond) BUILD_BUG_ON_INVALID(cond)
+#define VFS_WARN_ONCE(cond, format...) BUILD_BUG_ON_INVALID(cond)
+#define VFS_WARN(cond, format...) BUILD_BUG_ON_INVALID(cond)
+
+#define VFS_BUG_ON_INODE(cond, inode) VFS_BUG_ON(cond)
+#define VFS_WARN_ON_INODE(cond, inode) BUILD_BUG_ON_INVALID(cond)
+#endif /* CONFIG_DEBUG_VFS */
+
+#endif
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 1af972a92d06..c08ce985c482 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -808,6 +808,15 @@ config ARCH_HAS_DEBUG_VM_PGTABLE
An architecture should select this when it can successfully
build and run DEBUG_VM_PGTABLE.
+config DEBUG_VFS
+ bool "Debug VFS"
+ depends on DEBUG_KERNEL
+ help
+ Enable this to turn on extended checks in the VFS layer that may impact
+ performance.
+
+ If unsure, say N.
+
config DEBUG_VM_IRQSOFF
def_bool DEBUG_VM && !PREEMPT_RT
--
2.43.0
next prev parent reply other threads:[~2025-02-09 18:55 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-02-09 18:55 [PATCH v4 0/3] CONFIG_DEBUG_VFS at last Mateusz Guzik
2025-02-09 18:55 ` Mateusz Guzik [this message]
2025-02-10 8:28 ` [PATCH v4 1/3] vfs: add initial support for CONFIG_DEBUG_VFS Christian Brauner
2025-02-09 18:55 ` [PATCH v4 2/3] vfs: catch invalid modes in may_open() Mateusz Guzik
2025-02-09 18:55 ` [PATCH v4 3/3] vfs: use the new debug macros in inode_set_cached_link() Mateusz Guzik
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