Merge tag 'v3.10.54' into linux-linaro-lsk

[firefly-linux-kernel-4.4.55.git] / fs / ext4 / page-io.c

diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c
index 4acf1f78881b6c4c61aa10377a62ea4368106593..b12a4427aedc41f71bbbf697cbc61e17e30963cf 100644 (file)
--- a/fs/ext4/page-io.c
+++ b/fs/ext4/page-io.c
@@ -383,6 +383,17 @@ int ext4_bio_write_page(struct ext4_io_submit *io,
        set_page_writeback(page);
        ClearPageError(page);
 
+       /*
+        * Comments copied from block_write_full_page_endio:
+        *
+        * The page straddles i_size.  It must be zeroed out on each and every
+        * writepage invocation because it may be mmapped.  "A file is mapped
+        * in multiples of the page size.  For a file that is not a multiple of
+        * the page size, the remaining memory is zeroed when mapped, and
+        * writes to that region are not written out to the file."
+        */
+       if (len < PAGE_CACHE_SIZE)
+               zero_user_segment(page, len, PAGE_CACHE_SIZE);
        /*
         * In the first loop we prepare and mark buffers to submit. We have to
         * mark all buffers in the page before submitting so that
@@ -394,19 +405,6 @@ int ext4_bio_write_page(struct ext4_io_submit *io,
        do {
                block_start = bh_offset(bh);
                if (block_start >= len) {
-                       /*
-                        * Comments copied from block_write_full_page_endio:
-                        *
-                        * The page straddles i_size.  It must be zeroed out on
-                        * each and every writepage invocation because it may
-                        * be mmapped.  "A file is mapped in multiples of the
-                        * page size.  For a file that is not a multiple of
-                        * the  page size, the remaining memory is zeroed when
-                        * mapped, and writes to that region are not written
-                        * out to the file."
-                        */
-                       zero_user_segment(page, block_start,
-                                         block_start + blocksize);
                        clear_buffer_dirty(bh);
                        set_buffer_uptodate(bh);
                        continue;