export __set_page_dirty

XFS currently contains a copy-and-paste of __set_page_dirty().  Export
it from buffer.c instead.

Link: http://lkml.kernel.org/r/20180313132639.17387-6-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Acked-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 4 insertions, 14 deletions

diff --git a/fs/buffer.c b/fs/buffer.c
index ec5dd39071e6..64b1e2065b6b 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -594,7 +594,7 @@ EXPORT_SYMBOL(mark_buffer_dirty_inode);
  *
  * The caller must hold lock_page_memcg().
  */
-static void __set_page_dirty(struct page *page, struct address_space *mapping,
+void __set_page_dirty(struct page *page, struct address_space *mapping,
                              int warn)
 {
         unsigned long flags;
@@ -608,6 +608,7 @@ static void __set_page_dirty(struct page *page, struct address_space *mapping,
         }
         spin_unlock_irqrestore(&mapping->tree_lock, flags);
 }
+EXPORT_SYMBOL_GPL(__set_page_dirty);
 
 /*
  * Add a page to the dirty page list.
diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index 436a1de3fcdf..0ab824f574ed 100644
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -1467,19 +1467,8 @@ xfs_vm_set_page_dirty(
         newly_dirty = !TestSetPageDirty(page);
         spin_unlock(&mapping->private_lock);
 
-        if (newly_dirty) {
-                /* sigh - __set_page_dirty() is static, so copy it here, too */
-                unsigned long flags;
-
-                spin_lock_irqsave(&mapping->tree_lock, flags);
-                if (page->mapping) {    /* Race with truncate? */
-                        WARN_ON_ONCE(!PageUptodate(page));
-                        account_page_dirtied(page, mapping);
-                        radix_tree_tag_set(&mapping->page_tree,
-                                        page_index(page), PAGECACHE_TAG_DIRTY);
-                }
-                spin_unlock_irqrestore(&mapping->tree_lock, flags);
-        }
+        if (newly_dirty)
+                __set_page_dirty(page, mapping, 1);
         unlock_page_memcg(page);
         if (newly_dirty)
                 __mark_inode_dirty(mapping->host, I_DIRTY_PAGES);