[PATCH] mm/page-writeback.c: write_cache_pages(): deduplicate identical checks

From: Mauricio Faria de Oliveira
Date: Tue Feb 18 2020 - 16:26:46 EST

There used to be a 'retry' label in between the two (identical) checks
when first introduced in commit f446daaea9d4 ("mm: implement writeback
livelock avoidance using page tagging"), and later modified/updated in
commit 6e6938b6d313 ("writeback: introduce .tagged_writepages for the
WB_SYNC_NONE sync stage").

The label has been removed in commit 64081362e8ff ("mm/page-writeback.c:
fix range_cyclic writeback vs writepages deadlock"), and the (identical)
checks are now present / performed immediately one after another.

So, remove/deduplicate the latter check, moving tag_pages_for_writeback()
into the former check before the 'tag' variable assignment, so it's clear
that it's not used in this (similarly-named) function call but only later
in pagevec_lookup_range_tag().

Signed-off-by: Mauricio Faria de Oliveira <mfo@xxxxxxxxxxxxx>
mm/page-writeback.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 2caf780a42e7..86c18112b89b 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -2183,11 +2183,10 @@ int write_cache_pages(struct address_space *mapping,
range_whole = 1;
if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
+ tag_pages_for_writeback(mapping, index, end);
- if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
- tag_pages_for_writeback(mapping, index, end);
done_index = index;
while (!done && (index <= end)) {
int i;