From: Matthew Wilcox <willy@infradead.org>
To: Christoph Hellwig <hch@lst.de>,
Andrew Morton <akpm@linux-foundation.org>,
Jan Kara <jack@suse.cz>, Al Viro <viro@zeniv.linux.org.uk>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
linux-mm@kvack.org, linux-fsdevel@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/6] mm/writeback: Move __set_page_dirty() to core mm
Date: Wed, 16 Jun 2021 17:14:23 +0100 [thread overview]
Message-ID: <YMojXxiyYTRaQvJs@casper.infradead.org> (raw)
In-Reply-To: <20210615162342.1669332-2-willy@infradead.org>
On Tue, Jun 15, 2021 at 05:23:37PM +0100, Matthew Wilcox (Oracle) wrote:
> -/*
> - * Mark the page dirty, and set it dirty in the page cache, and mark the inode
> - * dirty.
> - *
> - * If warn is true, then emit a warning if the page is not uptodate and has
> - * not been truncated.
> - *
> - * The caller must hold lock_page_memcg().
> - */
Checking against my folio tree, I found a bit of extra documentation
that I had added and didn't make it into this submission. Let me know
if it's useful and if so I can submit it as a fixup patch:
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 73b937955cc1..2072787d9b44 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -2466,7 +2466,11 @@ void account_page_cleaned(struct page *page, struct addre
ss_space *mapping,
* If warn is true, then emit a warning if the page is not uptodate and has
* not been truncated.
*
- * The caller must hold lock_page_memcg().
+ * The caller must hold lock_page_memcg(). Most callers have the page
+ * locked. A few have the page blocked from truncation through other
+ * means (eg zap_page_range() has it mapped and is holding the page table
+ * lock). This can also be called from mark_buffer_dirty(), which I
+ * cannot prove is always protected against truncate.
*/
void __set_page_dirty(struct page *page, struct address_space *mapping,
int warn)
... it's a bit "notes to self", so perhaps someone can clean it up.
In particular, someone who knows the buffer code better than I do can
prove that mark_buffer_dirty() is always protected against truncate.
next prev parent reply other threads:[~2021-06-16 16:14 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-15 16:23 [PATCH 0/6] Further set_page_dirty cleanups Matthew Wilcox (Oracle)
2021-06-15 16:23 ` [PATCH 1/6] mm/writeback: Move __set_page_dirty() to core mm Matthew Wilcox (Oracle)
2021-06-15 16:35 ` Christoph Hellwig
2021-06-15 17:17 ` Greg Kroah-Hartman
2021-06-16 16:14 ` Matthew Wilcox [this message]
2021-06-15 16:23 ` [PATCH 2/6] mm/writeback: Use __set_page_dirty in __set_page_dirty_nobuffers Matthew Wilcox (Oracle)
2021-06-15 16:35 ` Christoph Hellwig
2021-06-15 17:18 ` Greg Kroah-Hartman
2021-06-15 16:23 ` [PATCH 3/6] iomap: Use __set_page_dirty_nobuffers Matthew Wilcox (Oracle)
2021-06-15 16:37 ` Christoph Hellwig
2021-06-15 17:19 ` Greg Kroah-Hartman
2021-06-15 17:32 ` Matthew Wilcox
2021-06-15 17:34 ` Christoph Hellwig
2021-06-15 18:04 ` Greg Kroah-Hartman
2021-06-15 18:13 ` Matthew Wilcox
2021-06-16 6:50 ` Greg Kroah-Hartman
2021-06-16 16:28 ` Matthew Wilcox
2021-06-16 16:35 ` Greg Kroah-Hartman
2021-06-15 16:23 ` [PATCH 4/6] fs: Remove anon_set_page_dirty() Matthew Wilcox (Oracle)
2021-06-15 16:37 ` Christoph Hellwig
2021-06-15 16:23 ` [PATCH 5/6] fs: Remove noop_set_page_dirty() Matthew Wilcox (Oracle)
2021-06-15 16:38 ` Christoph Hellwig
2021-06-16 18:10 ` kernel test robot
2021-06-16 18:12 ` Matthew Wilcox
2021-06-16 22:33 ` kernel test robot
2021-06-15 16:23 ` [PATCH 6/6] mm: Move page dirtying prototypes from mm.h Matthew Wilcox (Oracle)
2021-06-15 16:39 ` Christoph Hellwig
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