diff mbox series

[v4,1/3] vfs: add initial support for CONFIG_DEBUG_VFS

Message ID 20250209185523.745956-2-mjguzik@gmail.com (mailing list archive)
State New
Headers show
Series CONFIG_DEBUG_VFS at last | expand

Commit Message

Mateusz Guzik Feb. 9, 2025, 6:55 p.m. UTC 
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

Comments

Christian Brauner Feb. 10, 2025, 8:28 a.m. UTC | #1 
On Sun, Feb 09, 2025 at 07:55:20PM +0100, Mateusz Guzik wrote:
> 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);

I had already fixed that in the local tree. But thanks for resending.
I'll take v4 then.
diff mbox series

Patch

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