hugetlbfs: support tracepoint

Add basic tracepoints for {alloc, evict, free}_inode, setattr and
fallocate. These can help users to debug hugetlbfs more conveniently.

Signed-off-by: Hongbo Li <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Steven Rostedt (Google) <[email protected]>
Signed-off-by: Christian Brauner <[email protected]>

MAINTAINERS

@@ -10367,6 +10367,7 @@ F:	Documentation/mm/hugetlbfs_reserv.rst
 F:	Documentation/mm/vmemmap_dedup.rst
 F:	fs/hugetlbfs/
 F:	include/linux/hugetlb.h
+F:	include/trace/events/hugetlbfs.h
 F:	mm/hugetlb.c
 F:	mm/hugetlb_vmemmap.c
 F:	mm/hugetlb_vmemmap.h

include/trace/events/hugetlbfs.h

@@ -0,0 +1,156 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM hugetlbfs
+
+#if !defined(_TRACE_HUGETLBFS_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_HUGETLBFS_H
+
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(hugetlbfs_alloc_inode,
+
+	TP_PROTO(struct inode *inode, struct inode *dir, int mode),
+
+	TP_ARGS(inode, dir, mode),
+
+	TP_STRUCT__entry(
+		__field(dev_t,		dev)
+		__field(ino_t,		ino)
+		__field(ino_t,		dir)
+		__field(__u16,		mode)
+	),
+
+	TP_fast_assign(
+		__entry->dev		= inode->i_sb->s_dev;
+		__entry->ino		= inode->i_ino;
+		__entry->dir		= dir->i_ino;
+		__entry->mode		= mode;
+	),
+
+	TP_printk("dev %d,%d ino %lu dir %lu mode 0%o",
+		MAJOR(__entry->dev), MINOR(__entry->dev),
+		(unsigned long) __entry->ino,
+		(unsigned long) __entry->dir, __entry->mode)
+);
+
+DECLARE_EVENT_CLASS(hugetlbfs__inode,
+
+	TP_PROTO(struct inode *inode),
+
+	TP_ARGS(inode),
+
+	TP_STRUCT__entry(
+		__field(dev_t,		dev)
+		__field(ino_t,		ino)
+		__field(__u16,		mode)
+		__field(loff_t,		size)
+		__field(unsigned int,	nlink)
+		__field(unsigned int,	seals)
+		__field(blkcnt_t,	blocks)
+	),
+
+	TP_fast_assign(
+		__entry->dev		= inode->i_sb->s_dev;
+		__entry->ino		= inode->i_ino;
+		__entry->mode		= inode->i_mode;
+		__entry->size		= inode->i_size;
+		__entry->nlink		= inode->i_nlink;
+		__entry->seals		= HUGETLBFS_I(inode)->seals;
+		__entry->blocks		= inode->i_blocks;
+	),
+
+	TP_printk("dev %d,%d ino %lu mode 0%o size %lld nlink %u seals %u blocks %llu",
+		MAJOR(__entry->dev), MINOR(__entry->dev), (unsigned long) __entry->ino,
+		__entry->mode, __entry->size, __entry->nlink, __entry->seals,
+		(unsigned long long)__entry->blocks)
+);
+
+DEFINE_EVENT(hugetlbfs__inode, hugetlbfs_evict_inode,
+
+	TP_PROTO(struct inode *inode),
+
+	TP_ARGS(inode)
+);
+
+DEFINE_EVENT(hugetlbfs__inode, hugetlbfs_free_inode,
+
+	TP_PROTO(struct inode *inode),
+
+	TP_ARGS(inode)
+);
+
+TRACE_EVENT(hugetlbfs_setattr,
+
+	TP_PROTO(struct inode *inode, struct dentry *dentry,
+		struct iattr *attr),
+
+	TP_ARGS(inode, dentry, attr),
+
+	TP_STRUCT__entry(
+		__field(dev_t,		dev)
+		__field(ino_t,		ino)
+		__field(unsigned int,	d_len)
+		__string(d_name,	dentry->d_name.name)
+		__field(unsigned int,	ia_valid)
+		__field(unsigned int,	ia_mode)
+		__field(loff_t,		old_size)
+		__field(loff_t,		ia_size)
+	),
+
+	TP_fast_assign(
+		__entry->dev		= inode->i_sb->s_dev;
+		__entry->ino		= inode->i_ino;
+		__entry->d_len		= dentry->d_name.len;
+		__assign_str(d_name);
+		__entry->ia_valid	= attr->ia_valid;
+		__entry->ia_mode	= attr->ia_mode;
+		__entry->old_size	= inode->i_size;
+		__entry->ia_size	= attr->ia_size;
+	),
+
+	TP_printk("dev %d,%d ino %lu name %.*s valid %#x mode 0%o old_size %lld size %lld",
+		MAJOR(__entry->dev), MINOR(__entry->dev), (unsigned long)__entry->ino,
+		__entry->d_len, __get_str(d_name), __entry->ia_valid, __entry->ia_mode,
+		__entry->old_size, __entry->ia_size)
+);
+
+TRACE_EVENT(hugetlbfs_fallocate,
+
+	TP_PROTO(struct inode *inode, int mode,
+		loff_t offset, loff_t len, int ret),
+
+	TP_ARGS(inode, mode, offset, len, ret),
+
+	TP_STRUCT__entry(
+		__field(dev_t,		dev)
+		__field(ino_t,		ino)
+		__field(int,		mode)
+		__field(loff_t,		offset)
+		__field(loff_t,		len)
+		__field(loff_t,		size)
+		__field(int,		ret)
+	),
+
+	TP_fast_assign(
+		__entry->dev		= inode->i_sb->s_dev;
+		__entry->ino		= inode->i_ino;
+		__entry->mode		= mode;
+		__entry->offset		= offset;
+		__entry->len		= len;
+		__entry->size		= inode->i_size;
+		__entry->ret		= ret;
+	),
+
+	TP_printk("dev %d,%d ino %lu mode 0%o offset %lld len %lld size %lld ret %d",
+		MAJOR(__entry->dev), MINOR(__entry->dev),
+		(unsigned long)__entry->ino, __entry->mode,
+		(unsigned long long)__entry->offset,
+		(unsigned long long)__entry->len,
+		(unsigned long long)__entry->size,
+		__entry->ret)
+);
+
+#endif /* _TRACE_HUGETLBFS_H */
+
+ /* This part must be outside protection */
+#include <trace/define_trace.h>