From 2c21d4656e8d3c2af2b1e14809d076941ae69e96 Mon Sep 17 00:00:00 2001

Message-Id: <2c21d4656e8d3c2af2b1e14809d076941ae69e96.1468205827.git.panand@redhat.com>

From: Vitaly Kuznetsov <vkuznets@redhat.com>

Date: Fri, 17 Jun 2016 18:41:26 +0900

Subject: [PATCH] [PATCH v2] Support _count -> _refcount rename in struct page

_count member was renamed to _refcount in linux commit 0139aa7b7fa12

("mm: rename _count, field of the struct page, to _refcount") and this

broke makedumpfile. The reason for making the change was to find all users

accessing it directly and not through the recommended API. I tried

suggesting to revert the change but failed, I see no other choice than to

start supporting both _count and _refcount in makedumpfile.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>

---

 makedumpfile-1.6.0/makedumpfile.c | 26 +++++++++++++++++++++-----

 makedumpfile-1.6.0/makedumpfile.h |  3 ++-

 2 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/makedumpfile-1.6.0/makedumpfile.c b/makedumpfile-1.6.0/makedumpfile.c

index 853b99951706..fd884d3796be 100644

--- a/makedumpfile-1.6.0/makedumpfile.c

+++ b/makedumpfile-1.6.0/makedumpfile.c

@@ -1579,7 +1579,14 @@ get_structure_info(void)

 	 */

 	SIZE_INIT(page, "page");

 	OFFSET_INIT(page.flags, "page", "flags");

-	OFFSET_INIT(page._count, "page", "_count");

+	OFFSET_INIT(page._refcount, "page", "_refcount");

+	if (OFFSET(page._refcount) == NOT_FOUND_STRUCTURE) {

+		info->flag_use_count = TRUE;

+		OFFSET_INIT(page._refcount, "page", "_count");

+	} else {

+		info->flag_use_count = FALSE;

+	}

+

 	OFFSET_INIT(page.mapping, "page", "mapping");

 	OFFSET_INIT(page._mapcount, "page", "_mapcount");

 	OFFSET_INIT(page.private, "page", "private");

@@ -2044,7 +2051,7 @@ get_mem_type(void)

 	if ((SIZE(page) == NOT_FOUND_STRUCTURE)

 	    || (OFFSET(page.flags) == NOT_FOUND_STRUCTURE)

-	    || (OFFSET(page._count) == NOT_FOUND_STRUCTURE)

+	    || (OFFSET(page._refcount) == NOT_FOUND_STRUCTURE)

 	    || (OFFSET(page.mapping) == NOT_FOUND_STRUCTURE)) {

 		ret = NOT_FOUND_MEMTYPE;

 	} else if ((((SYMBOL(node_data) != NOT_FOUND_SYMBOL)

@@ -2151,7 +2158,10 @@ write_vmcoreinfo_data(void)

 	 * write the member offset of 1st kernel

 	 */

 	WRITE_MEMBER_OFFSET("page.flags", page.flags);

-	WRITE_MEMBER_OFFSET("page._count", page._count);

+	if (info->flag_use_count)

+		WRITE_MEMBER_OFFSET("page._count", page._refcount);

+	else

+		WRITE_MEMBER_OFFSET("page._refcount", page._refcount);

 	WRITE_MEMBER_OFFSET("page.mapping", page.mapping);

 	WRITE_MEMBER_OFFSET("page.lru", page.lru);

 	WRITE_MEMBER_OFFSET("page._mapcount", page._mapcount);

@@ -2491,7 +2501,13 @@ read_vmcoreinfo(void)

 	READ_MEMBER_OFFSET("page.flags", page.flags);

-	READ_MEMBER_OFFSET("page._count", page._count);

+	READ_MEMBER_OFFSET("page._refcount", page._refcount);

+	if (OFFSET(page._refcount) == NOT_FOUND_STRUCTURE) {

+		info->flag_use_count = TRUE;

+		READ_MEMBER_OFFSET("page._count", page._refcount);

+	} else {

+		info->flag_use_count = FALSE;

+	}

 	READ_MEMBER_OFFSET("page.mapping", page.mapping);

 	READ_MEMBER_OFFSET("page.lru", page.lru);

 	READ_MEMBER_OFFSET("page._mapcount", page._mapcount);

@@ -5615,7 +5631,7 @@ __exclude_unnecessary_pages(unsigned long mem_map,

 		pcache  = page_cache + (index_pg * SIZE(page));

 		flags   = ULONG(pcache + OFFSET(page.flags));

-		_count  = UINT(pcache + OFFSET(page._count));

+		_count  = UINT(pcache + OFFSET(page._refcount));

 		mapping = ULONG(pcache + OFFSET(page.mapping));

 		if (OFFSET(page.compound_order) != NOT_FOUND_STRUCTURE) {

diff --git a/makedumpfile-1.6.0/makedumpfile.h b/makedumpfile-1.6.0/makedumpfile.h

index 251d4bfac060..533e5b89f345 100644

--- a/makedumpfile-1.6.0/makedumpfile.h

+++ b/makedumpfile-1.6.0/makedumpfile.h

@@ -1100,6 +1100,7 @@ struct DumpInfo {

 	int		flag_nospace;	     /* the flag of "No space on device" error */

 	int		flag_vmemmap;        /* kernel supports vmemmap address space */

 	int		flag_excludevm;      /* -e - excluding unused vmemmap pages */

+	int		flag_use_count;      /* _refcount is named _count in struct page */

 	unsigned long	vaddr_for_vtop;      /* virtual address for debugging */

 	long		page_size;           /* size of page */

 	long		page_shift;

@@ -1483,7 +1484,7 @@ struct size_table {

 struct offset_table {

 	struct page {

 		long	flags;

-		long	_count;

+		long	_refcount;

 		long	mapping;

 		long	lru;

 		long	_mapcount;

-- 

2.5.5