From 91196c20a37bb5990e4358ff97dbeb2bd3007154 Mon Sep 17 00:00:00 2001 From: Jinshan Xiong Date: Tue, 16 Aug 2016 16:18:44 -0400 Subject: [PATCH] staging: lustre: llite: avoid a deadlock in page write For a partial page write, it will have to issue a READ RPC firstly to get a full uptodate page. If another page is already locked by this thread it can easily cause deadlock. Signed-off-by: Jinshan Xiong Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-4873 Reviewed-on: http://review.whamcloud.com/9928 Reviewed-by: Bobi Jam Reviewed-by: Niu Yawei Reviewed-by: Oleg Drokin Signed-off-by: James Simmons Signed-off-by: Greg Kroah-Hartman --- drivers/staging/lustre/lustre/llite/rw26.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/staging/lustre/lustre/llite/rw26.c b/drivers/staging/lustre/lustre/llite/rw26.c index d98c7acc0832..c14a1b680505 100644 --- a/drivers/staging/lustre/lustre/llite/rw26.c +++ b/drivers/staging/lustre/lustre/llite/rw26.c @@ -506,8 +506,9 @@ static int ll_write_begin(struct file *file, struct address_space *mapping, env = lcc->lcc_env; io = lcc->lcc_io; - /* To avoid deadlock, try to lock page first. */ - vmpage = grab_cache_page_nowait(mapping, index); + if (likely(to == PAGE_SIZE)) /* LU-4873 */ + /* To avoid deadlock, try to lock page first. */ + vmpage = grab_cache_page_nowait(mapping, index); if (unlikely(!vmpage || PageDirty(vmpage) || PageWriteback(vmpage))) { struct vvp_io *vio = vvp_env_io(env); struct cl_page_list *plist = &vio->u.write.vui_queue; -- 2.20.1