f2fs: add some tracepoints to debug volatile and atomic writes

Signed-off-by: Jaegeuk Kim <[e-mail]>

fs/f2fs/data.c

···
 			need_inplace_update(inode))) {
 		rewrite_data_page(page, fio);
 		set_inode_flag(F2FS_I(inode), FI_UPDATE_WRITE);
+		trace_f2fs_do_write_data_page(page, IPU);
 	} else {
 		write_data_page(page, &dn, fio);
 		f2fs_update_extent_cache(&dn);
+		trace_f2fs_do_write_data_page(page, OPU);
 		set_inode_flag(F2FS_I(inode), FI_APPEND_WRITE);
 		if (page->index == 0)
 			set_inode_flag(F2FS_I(inode), FI_FIRST_BLOCK_WRITTEN);

fs/f2fs/f2fs.h

···
 	META,
 	NR_PAGE_TYPE,
 	META_FLUSH,
+	INMEM,		/* the below types are used by tracepoints only. */
+	INMEM_DROP,
+	IPU,
+	OPU,
 };
 
 struct f2fs_io_info {

fs/f2fs/segment.c

···
 	list_add_tail(&new->list, &fi->inmem_pages);
 	inc_page_count(F2FS_I_SB(inode), F2FS_INMEM_PAGES);
 	mutex_unlock(&fi->inmem_lock);
+
+	trace_f2fs_register_inmem_page(page, INMEM);
 }
 
 void commit_inmem_pages(struct inode *inode, bool abort)
···
 				f2fs_wait_on_page_writeback(cur->page, DATA);
 				if (clear_page_dirty_for_io(cur->page))
 					inode_dec_dirty_pages(inode);
+				trace_f2fs_commit_inmem_page(cur->page, INMEM);
 				do_write_data_page(cur->page, &fio);
 				submit_bio = true;
 			}
 			f2fs_put_page(cur->page, 1);
 		} else {
+			trace_f2fs_commit_inmem_page(cur->page, INMEM_DROP);
 			put_page(cur->page);
 		}
 		radix_tree_delete(&fi->inmem_root, cur->page->index);

include/trace/events/f2fs.h

···
 		{ NODE,		"NODE" },				\
 		{ DATA,		"DATA" },				\
 		{ META,		"META" },				\
-		{ META_FLUSH,	"META_FLUSH" })
+		{ META_FLUSH,	"META_FLUSH" },				\
+		{ INMEM,	"INMEM" },				\
+		{ INMEM_DROP,	"INMEM_DROP" },				\
+		{ IPU,		"IN-PLACE" },				\
+		{ OPU,		"OUT-OF-PLACE" })
 
 #define F2FS_BIO_MASK(t)	(t & (READA | WRITE_FLUSH_FUA))
 #define F2FS_BIO_EXTRA_MASK(t)	(t & (REQ_META | REQ_PRIO))
···
 	TP_ARGS(page, type)
 );
 
+DEFINE_EVENT(f2fs__page, f2fs_do_write_data_page,
+
+	TP_PROTO(struct page *page, int type),
+
+	TP_ARGS(page, type)
+);
+
 DEFINE_EVENT(f2fs__page, f2fs_readpage,
 
 	TP_PROTO(struct page *page, int type),
···
 );
 
 DEFINE_EVENT(f2fs__page, f2fs_vm_page_mkwrite,
+
+	TP_PROTO(struct page *page, int type),
+
+	TP_ARGS(page, type)
+);
+
+DEFINE_EVENT(f2fs__page, f2fs_register_inmem_page,
+
+	TP_PROTO(struct page *page, int type),
+
+	TP_ARGS(page, type)
+);
+
+DEFINE_EVENT(f2fs__page, f2fs_commit_inmem_page,
 
 	TP_PROTO(struct page *page, int type),