diff mbox series

[1/6] mm/writeback: Move __set_page_dirty() to core mm

Message ID 20210615162342.1669332-2-willy@infradead.org (mailing list archive)
State New
Headers show
Series Further set_page_dirty cleanups | expand

Commit Message

Matthew Wilcox June 15, 2021, 4:23 p.m. UTC
Nothing in __set_page_dirty() is specific to buffer_head, so
move it to mm/page-writeback.c.  That removes the only caller of
account_page_dirtied() outside of page-writeback.c, so make it static.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
 fs/buffer.c         | 24 ------------------------
 include/linux/mm.h  |  1 -
 mm/page-writeback.c | 27 ++++++++++++++++++++++++++-
 3 files changed, 26 insertions(+), 26 deletions(-)

Comments

Christoph Hellwig June 15, 2021, 4:35 p.m. UTC | #1
Looks good,

Reviewed-by: Christoph Hellwig <hch@lst.de>
Greg Kroah-Hartman June 15, 2021, 5:17 p.m. UTC | #2
On Tue, Jun 15, 2021 at 05:23:37PM +0100, Matthew Wilcox (Oracle) wrote:
> Nothing in __set_page_dirty() is specific to buffer_head, so
> move it to mm/page-writeback.c.  That removes the only caller of
> account_page_dirtied() outside of page-writeback.c, so make it static.
> 
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
> ---
>  fs/buffer.c         | 24 ------------------------
>  include/linux/mm.h  |  1 -
>  mm/page-writeback.c | 27 ++++++++++++++++++++++++++-
>  3 files changed, 26 insertions(+), 26 deletions(-)
> 

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Matthew Wilcox June 16, 2021, 4:14 p.m. UTC | #3
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.
diff mbox series

Patch

diff --git a/fs/buffer.c b/fs/buffer.c
index 8c02e44f16f2..f5384cff7e0c 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -588,30 +588,6 @@  void mark_buffer_dirty_inode(struct buffer_head *bh, struct inode *inode)
 }
 EXPORT_SYMBOL(mark_buffer_dirty_inode);
 
-/*
- * 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().
- */
-void __set_page_dirty(struct page *page, struct address_space *mapping,
-			     int warn)
-{
-	unsigned long flags;
-
-	xa_lock_irqsave(&mapping->i_pages, flags);
-	if (page->mapping) {	/* Race with truncate? */
-		WARN_ON_ONCE(warn && !PageUptodate(page));
-		account_page_dirtied(page, mapping);
-		__xa_set_mark(&mapping->i_pages, page_index(page),
-				PAGECACHE_TAG_DIRTY);
-	}
-	xa_unlock_irqrestore(&mapping->i_pages, flags);
-}
-
 /*
  * Add a page to the dirty page list.
  *
diff --git a/include/linux/mm.h b/include/linux/mm.h
index d64f8a1284d9..1086b556961a 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1858,7 +1858,6 @@  int __set_page_dirty_nobuffers(struct page *page);
 int __set_page_dirty_no_writeback(struct page *page);
 int redirty_page_for_writepage(struct writeback_control *wbc,
 				struct page *page);
-void account_page_dirtied(struct page *page, struct address_space *mapping);
 void account_page_cleaned(struct page *page, struct address_space *mapping,
 			  struct bdi_writeback *wb);
 int set_page_dirty(struct page *page);
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index f6ee085767cb..0c2c8355f97f 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -2420,7 +2420,8 @@  int __set_page_dirty_no_writeback(struct page *page)
  *
  * NOTE: This relies on being atomic wrt interrupts.
  */
-void account_page_dirtied(struct page *page, struct address_space *mapping)
+static void account_page_dirtied(struct page *page,
+		struct address_space *mapping)
 {
 	struct inode *inode = mapping->host;
 
@@ -2461,6 +2462,30 @@  void account_page_cleaned(struct page *page, struct address_space *mapping,
 	}
 }
 
+/*
+ * 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().
+ */
+void __set_page_dirty(struct page *page, struct address_space *mapping,
+			     int warn)
+{
+	unsigned long flags;
+
+	xa_lock_irqsave(&mapping->i_pages, flags);
+	if (page->mapping) {	/* Race with truncate? */
+		WARN_ON_ONCE(warn && !PageUptodate(page));
+		account_page_dirtied(page, mapping);
+		__xa_set_mark(&mapping->i_pages, page_index(page),
+				PAGECACHE_TAG_DIRTY);
+	}
+	xa_unlock_irqrestore(&mapping->i_pages, flags);
+}
+
 /*
  * For address_spaces which do not use buffers.  Just tag the page as dirty in
  * the xarray.