From ece014141cd4b49f2d763f28b19e417b84460560 Mon Sep 17 00:00:00 2001
From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Date: Mon, 3 May 2021 07:29:47 -0400
Subject: [PATCH] mm/doc: Add documentation for folio_test_uptodate
Move the PG_uptodate documentation to be documentation for
folio_test_uptodate() and expand on it a little.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
---
include/linux/page-flags.h | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index b5f14d5811135..b3d353d537e29 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -68,9 +68,6 @@
* might lose their PG_swapbacked flag when they simply can be dropped (e.g. as
* a result of MADV_FREE).
*
- * PG_uptodate tells whether the page's contents is valid. When a read
- * completes, the page becomes uptodate, unless a disk I/O error happened.
- *
* PG_referenced, PG_reclaim are used for page reclaim for anonymous and
* file-backed pagecache (see mm/vmscan.c).
*
@@ -615,6 +612,16 @@ TESTPAGEFLAG_FALSE(Ksm, ksm)
u64 stable_page_flags(struct page *page);
+/**
+ * folio_test_uptodate - Is this folio up to date?
+ * @folio: The folio.
+ *
+ * The uptodate flag is set on a folio when every byte in the folio is
+ * at least as new as the corresponding bytes on storage. Anonymous
+ * and CoW folios are always uptodate. If the folio is not uptodate,
+ * some of the bytes in it may be; see the is_partially_uptodate()
+ * address_space operation.
+ */
static inline bool folio_test_uptodate(struct folio *folio)
{
bool ret = test_bit(PG_uptodate, folio_flags(folio, 0));
--
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