f2fs: initialize page->private when using for our internal use

We need to guarantee it's initially zero. Otherwise, it'll hurt entire flag
operations.

Fixes: b763f3bedc2d ("f2fs: restructure f2fs page.private layout")
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 3a01a1b..d2cf48c 100644 (file)
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -3819,6 +3819,8 @@ int f2fs_migrate_page(struct address_space *mapping,
                get_page(newpage);
        }
 
+       /* guarantee to start from no stale private field */
+       set_page_private(newpage, 0);
        if (PagePrivate(page)) {
                set_page_private(newpage, page_private(page));
                SetPagePrivate(newpage);

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 65befc6..ee8eb33 100644 (file)
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1331,7 +1331,8 @@ enum {
 #define PAGE_PRIVATE_GET_FUNC(name, flagname) \
 static inline bool page_private_##name(struct page *page) \
 { \
-       return test_bit(PAGE_PRIVATE_NOT_POINTER, &page_private(page)) && \
+       return PagePrivate(page) && \
+               test_bit(PAGE_PRIVATE_NOT_POINTER, &page_private(page)) && \
                test_bit(PAGE_PRIVATE_##flagname, &page_private(page)); \
 }
 
@@ -1341,6 +1342,7 @@ static inline void set_page_private_##name(struct page *page) \
        if (!PagePrivate(page)) { \
                get_page(page); \
                SetPagePrivate(page); \
+               set_page_private(page, 0); \
        } \
        set_bit(PAGE_PRIVATE_NOT_POINTER, &page_private(page)); \
        set_bit(PAGE_PRIVATE_##flagname, &page_private(page)); \
@@ -1392,6 +1394,7 @@ static inline void set_page_private_data(struct page *page, unsigned long data)
        if (!PagePrivate(page)) {
                get_page(page);
                SetPagePrivate(page);
+               set_page_private(page, 0);
        }
        set_bit(PAGE_PRIVATE_NOT_POINTER, &page_private(page));
        page_private(page) |= data << PAGE_PRIVATE_MAX;