[PATCH 3.16 045/202] fuse: decrement NR_WRITEBACK_TEMP on the right page

[Ben Hutchings]

3.16.66-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Miklos Szeredi <mszer...@redhat.com>

commit a2ebba824106dabe79937a9f29a875f837e1b6d4 upstream.

NR_WRITEBACK_TEMP is accounted on the temporary page in the request, not
the page cache page.

Fixes: 8b284dc47291 ("fuse: writepages: handle same page rewrites")
Signed-off-by: Miklos Szeredi <mszer...@redhat.com>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <b...@decadent.org.uk>
---
 fs/fuse/file.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -1846,7 +1846,7 @@ static bool fuse_writepage_in_flight(str
                spin_unlock(&fc->lock);
 
                dec_bdi_stat(bdi, BDI_WRITEBACK);
-               dec_zone_page_state(page, NR_WRITEBACK_TEMP);
+               dec_zone_page_state(new_req->pages[0], NR_WRITEBACK_TEMP);
                bdi_writeout_inc(bdi);
                fuse_writepage_free(fc, new_req);
                fuse_request_free(new_req);