From e913fc825dc685a444cb4c1d0f9d32f372f59861 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Mon, 17 May 2010 12:55:07 +0200 Subject: writeback: fix WB_SYNC_NONE writeback from umount When umount calls sync_filesystem(), we first do a WB_SYNC_NONE writeback to kick off writeback of pending dirty inodes, then follow that up with a WB_SYNC_ALL to wait for it. Since umount already holds the sb s_umount mutex, WB_SYNC_NONE ends up doing nothing and all writeback happens as WB_SYNC_ALL. This can greatly slow down umount, since WB_SYNC_ALL writeback is a data integrity operation and thus a bigger hammer than simple WB_SYNC_NONE. For barrier aware file systems it's a lot slower. Signed-off-by: Jens Axboe --- mm/page-writeback.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'mm/page-writeback.c') diff --git a/mm/page-writeback.c b/mm/page-writeback.c index d0f2b3765f8..53b2fcf2d28 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -597,7 +597,7 @@ static void balance_dirty_pages(struct address_space *mapping, (!laptop_mode && ((global_page_state(NR_FILE_DIRTY) + global_page_state(NR_UNSTABLE_NFS)) > background_thresh))) - bdi_start_writeback(bdi, NULL, 0); + bdi_start_writeback(bdi, NULL, 0, 0); } void set_page_dirty_balance(struct page *page, int page_mkwrite) @@ -705,7 +705,7 @@ void laptop_mode_timer_fn(unsigned long data) */ if (bdi_has_dirty_io(&q->backing_dev_info)) - bdi_start_writeback(&q->backing_dev_info, NULL, nr_pages); + bdi_start_writeback(&q->backing_dev_info, NULL, 0, nr_pages); } /* -- cgit v1.2.3