JFS: clear PAGECACHE_TAG_DIRTY for no-write pages

When JFS decides to drop a dirty metapage, it simply clears the META_dirty
bit and leave alone the PG_dirty and PAGECACHE_TAG_DIRTY bits.

When such no-write page goes to metapage_writepage(), the `relic'
PAGECACHE_TAG_DIRTY tag should be cleared, to prevent pdflush from
repeatedly trying to sync them.  This is done through
set_page_writeback(), so call it should be called in all cases.  If
no I/O is initiated, end_page_writeback() should be called immediately.

This is how __block_write_full_page() does things.

Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
CC: Fengguang Wu <wfg@mail.ustc.edu.cn>

1 files changed, 8 insertions, 3 deletions

diff --git a/fs/jfs/jfs_metapage.c b/fs/jfs/jfs_metapage.c
index f5cd8d38af7a..b27fa117f229 100644
--- a/fs/jfs/jfs_metapage.c
+++ b/fs/jfs/jfs_metapage.c
@@ -360,6 +360,7 @@ static int metapage_writepage(struct page *page, struct writeback_control *wbc)
         struct metapage *mp;
         int redirty = 0;
         sector_t lblock;
+        int nr_underway = 0;
         sector_t pblock;
         sector_t next_block = 0;
         sector_t page_start;
@@ -371,6 +372,7 @@ static int metapage_writepage(struct page *page, struct writeback_control *wbc)
                      (PAGE_CACHE_SHIFT - inode->i_blkbits);
         BUG_ON(!PageLocked(page));
         BUG_ON(PageWriteback(page));
+        set_page_writeback(page);
 
         for (offset = 0; offset < PAGE_CACHE_SIZE; offset += PSIZE) {
                 mp = page_to_mp(page, offset);
@@ -413,11 +415,10 @@ static int metapage_writepage(struct page *page, struct writeback_control *wbc)
                         if (!bio->bi_size)
                                 goto dump_bio;
                         submit_bio(WRITE, bio);
+                        nr_underway++;
                         bio = NULL;
-                } else {
-                        set_page_writeback(page);
+                } else
                         inc_io(page);
-                }
                 xlen = (PAGE_CACHE_SIZE - offset) >> inode->i_blkbits;
                 pblock = metapage_get_blocks(inode, lblock, &xlen);
                 if (!pblock) {
@@ -449,12 +450,16 @@ static int metapage_writepage(struct page *page, struct writeback_control *wbc)
                         goto dump_bio;
 
                 submit_bio(WRITE, bio);
+                nr_underway++;
         }
         if (redirty)
                 redirty_page_for_writepage(wbc, page);
 
         unlock_page(page);
 
+        if (nr_underway == 0)
+                end_page_writeback(page);
+
         return 0;
 add_failed:
         /* We should never reach here, since we're only adding one vec */