5 files changed, 29 insertions, 11 deletions

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 1d08a1b51bdd..aeda5061a59a 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -2772,7 +2772,8 @@ extern void ext4_io_submit(struct ext4_io_submit *io);
 extern int ext4_bio_write_page(struct ext4_io_submit *io,
                                struct page *page,
                                int len,
-                               struct writeback_control *wbc);
+                               struct writeback_control *wbc,
+                               bool keep_towrite);
 
 /* mmp.c */
 extern int ext4_multi_mount_protect(struct super_block *, ext4_fsblk_t);
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 9b3c52fbe86d..04dd2de10796 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -1846,6 +1846,7 @@ static int ext4_writepage(struct page *page,
         struct buffer_head *page_bufs = NULL;
         struct inode *inode = page->mapping->host;
         struct ext4_io_submit io_submit;
+        bool keep_towrite = false;
 
         trace_ext4_writepage(page);
         size = i_size_read(inode);
@@ -1876,6 +1877,7 @@ static int ext4_writepage(struct page *page,
                         unlock_page(page);
                         return 0;
                 }
+                keep_towrite = true;
         }
 
         if (PageChecked(page) && ext4_should_journal_data(inode))
@@ -1892,7 +1894,7 @@ static int ext4_writepage(struct page *page,
                 unlock_page(page);
                 return -ENOMEM;
         }
-        ret = ext4_bio_write_page(&io_submit, page, len, wbc);
+        ret = ext4_bio_write_page(&io_submit, page, len, wbc, keep_towrite);
         ext4_io_submit(&io_submit);
         /* Drop io_end reference we got from init */
         ext4_put_io_end_defer(io_submit.io_end);
@@ -1911,7 +1913,7 @@ static int mpage_submit_page(struct mpage_da_data *mpd, struct page *page)
         else
                 len = PAGE_CACHE_SIZE;
         clear_page_dirty_for_io(page);
-        err = ext4_bio_write_page(&mpd->io_submit, page, len, mpd->wbc);
+        err = ext4_bio_write_page(&mpd->io_submit, page, len, mpd->wbc, false);
         if (!err)
                 mpd->wbc->nr_to_write--;
         mpd->first_page++;
diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c
index c18d95b50540..4cb2743cb2e3 100644
--- a/fs/ext4/page-io.c
+++ b/fs/ext4/page-io.c
@@ -401,7 +401,8 @@ submit_and_retry:
 int ext4_bio_write_page(struct ext4_io_submit *io,
                         struct page *page,
                         int len,
-                        struct writeback_control *wbc)
+                        struct writeback_control *wbc,
+                        bool keep_towrite)
 {
         struct inode *inode = page->mapping->host;
         unsigned block_start, blocksize;
@@ -414,7 +415,10 @@ int ext4_bio_write_page(struct ext4_io_submit *io,
         BUG_ON(!PageLocked(page));
         BUG_ON(PageWriteback(page));
 
-        set_page_writeback(page);
+        if (keep_towrite)
+                set_page_writeback_keepwrite(page);
+        else
+                set_page_writeback(page);
         ClearPageError(page);
 
         /*
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index d1fe1a761047..ca71a1d347a0 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -317,13 +317,23 @@ CLEARPAGEFLAG(Uptodate, uptodate)
 extern void cancel_dirty_page(struct page *page, unsigned int account_size);
 
 int test_clear_page_writeback(struct page *page);
-int test_set_page_writeback(struct page *page);
+int __test_set_page_writeback(struct page *page, bool keep_write);
+
+#define test_set_page_writeback(page)                   \
+        __test_set_page_writeback(page, false)
+#define test_set_page_writeback_keepwrite(page) \
+        __test_set_page_writeback(page, true)
 
 static inline void set_page_writeback(struct page *page)
 {
         test_set_page_writeback(page);
 }
 
+static inline void set_page_writeback_keepwrite(struct page *page)
+{
+        test_set_page_writeback_keepwrite(page);
+}
+
 #ifdef CONFIG_PAGEFLAGS_EXTENDED
 /*
  * System with lots of page flags available. This allows separate
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index ef413492a149..d8691d9de3c4 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -2398,7 +2398,7 @@ int test_clear_page_writeback(struct page *page)
         return ret;
 }
 
-int test_set_page_writeback(struct page *page)
+int __test_set_page_writeback(struct page *page, bool keep_write)
 {
         struct address_space *mapping = page_mapping(page);
         int ret;
@@ -2423,9 +2423,10 @@ int test_set_page_writeback(struct page *page)
                         radix_tree_tag_clear(&mapping->page_tree,
                                                 page_index(page),
                                                 PAGECACHE_TAG_DIRTY);
-                radix_tree_tag_clear(&mapping->page_tree,
-                                     page_index(page),
-                                     PAGECACHE_TAG_TOWRITE);
+                if (!keep_write)
+                        radix_tree_tag_clear(&mapping->page_tree,
+                                                page_index(page),
+                                                PAGECACHE_TAG_TOWRITE);
                 spin_unlock_irqrestore(&mapping->tree_lock, flags);
         } else {
                 ret = TestSetPageWriteback(page);
@@ -2436,7 +2437,7 @@ int test_set_page_writeback(struct page *page)
         return ret;
 
 }
-EXPORT_SYMBOL(test_set_page_writeback);
+EXPORT_SYMBOL(__test_set_page_writeback);
 
 /*
  * Return true if any of the pages in the mapping are marked with the