The patch titled
Subject: include/linux/pagemap.h: introduce attach/detach_page_private
has been added to the -mm tree. Its filename is
include-linux-pagemaph-introduce-attach-detach_page_private.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/include-linux-pagemaph-introduce-attach-detach_page_private.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/include-linux-pagemaph-introduce-attach-detach_page_private.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Guoqing Jiang <guoqing.jiang@xxxxxxxxxxxxxxx>
Subject: include/linux/pagemap.h: introduce attach/detach_page_private
Patch series "Introduce attach/detach_page_private to cleanup code".
This patch (of 10):
The logic in attach_page_buffers and __clear_page_buffers are quite
paired, but
1. they are located in different files.
2. attach_page_buffers is implemented in buffer_head.h, so it could be
used by other files. But __clear_page_buffers is static function in
buffer.c and other potential users can't call the function, md-bitmap
even copied the function.
So, introduce the new attach/detach_page_private to replace them. With
the new pair of function, we will remove the usage of attach_page_buffers
and __clear_page_buffers in next patches. Thanks for suggestions about
the function name from Alexander Viro, Andreas Grünbacher, Christoph
Hellwig and Matthew Wilcox.
Link: http://lkml.kernel.org/r/20200517214718.468-1-guoqing.jiang@xxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/20200517214718.468-2-guoqing.jiang@xxxxxxxxxxxxxxx
Signed-off-by: Guoqing Jiang <guoqing.jiang@xxxxxxxxxxxxxxx>
Suggested-by: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: "Darrick J. Wong" <darrick.wong@xxxxxxxxxx>
Cc: William Kucharski <william.kucharski@xxxxxxxxxx>
Cc: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Andreas Gruenbacher <agruenba@xxxxxxxxxx>
Cc: Yang Shi <yang.shi@xxxxxxxxxxxxxxxxx>
Cc: Yafang Shao <laoar.shao@xxxxxxxxx>
Cc: Song Liu <song@xxxxxxxxxx>
Cc: Chris Mason <clm@xxxxxx>
Cc: Josef Bacik <josef@xxxxxxxxxxxxxx>
Cc: David Sterba <dsterba@xxxxxxxx>
Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
Cc: Chao Yu <chao@xxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx>
Cc: Anton Altaparmakov <anton@xxxxxxxxxx>
Cc: Mike Marshall <hubcap@xxxxxxxxxxxx>
Cc: Martin Brandenburg <martin@xxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Cc: Roman Gushchin <guro@xxxxxx>
Cc: Andreas Dilger <adilger@xxxxxxxxx>
Cc: Chao Yu <yuchao0@xxxxxxxxxx>
Cc: Dave Chinner <david@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/pagemap.h | 37 +++++++++++++++++++++++++++++++++++++
1 file changed, 37 insertions(+)
--- a/include/linux/pagemap.h~include-linux-pagemaph-introduce-attach-detach_page_private
+++ a/include/linux/pagemap.h
@@ -208,6 +208,43 @@ static inline int page_cache_add_specula
return __page_cache_add_speculative(page, count);
}
+/**
+ * attach_page_private - Attach private data to a page.
+ * @page: Page to attach data to.
+ * @data: Data to attach to page.
+ *
+ * Attaching private data to a page increments the page's reference count.
+ * The data must be detached before the page will be freed.
+ */
+static inline void attach_page_private(struct page *page, void *data)
+{
+ get_page(page);
+ set_page_private(page, (unsigned long)data);
+ SetPagePrivate(page);
+}
+
+/**
+ * detach_page_private - Detach private data from a page.
+ * @page: Page to detach data from.
+ *
+ * Removes the data that was previously attached to the page and decrements
+ * the refcount on the page.
+ *
+ * Return: Data that was attached to the page.
+ */
+static inline void *detach_page_private(struct page *page)
+{
+ void *data = (void *)page_private(page);
+
+ if (!PagePrivate(page))
+ return NULL;
+ ClearPagePrivate(page);
+ set_page_private(page, 0);
+ put_page(page);
+
+ return data;
+}
+
#ifdef CONFIG_NUMA
extern struct page *__page_cache_alloc(gfp_t gfp);
#else
_
Patches currently in -mm which might be from guoqing.jiang@xxxxxxxxxxxxxxx are
include-linux-pagemaph-introduce-attach-detach_page_private.patch
md-remove-__clear_page_buffers-and-use-attach-detach_page_private.patch
btrfs-use-attach-detach_page_private.patch
fs-bufferc-use-attach-detach_page_private.patch
f2fs-use-attach-detach_page_private.patch
iomap-use-attach-detach_page_private.patch
ntfs-replace-attach_page_buffers-with-attach_page_private.patch
orangefs-use-attach-detach_page_private.patch
buffer_headh-remove-attach_page_buffers.patch
mm-migratec-call-detach_page_private-to-cleanup-code.patch
