From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ryan Ding , Junxiao Bi , Al Viro , Mark Fasheh , Joel Becker , Andrew Morton , Linus Torvalds Subject: [PATCH 4.2 118/120] ocfs2: direct write will call ocfs2_rw_unlock() twice when doing aio+dio Date: Sat, 19 Sep 2015 10:29:18 -0700 Message-Id: <20150919171732.948096627@linuxfoundation.org> In-Reply-To: <20150919171712.735441938@linuxfoundation.org> References: <20150919171712.735441938@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ryan Ding commit aa1057b3dec478b20c77bad07442318ae36d893c upstream. ocfs2_file_write_iter() is usng the wrong return value ('written'). This will cause ocfs2_rw_unlock() be called both in write_iter & end_io, triggering a BUG_ON. This issue was introduced by commit 7da839c47589 ("ocfs2: use __generic_file_write_iter()"). Orabug: 21612107 Fixes: 7da839c47589 ("ocfs2: use __generic_file_write_iter()") Signed-off-by: Ryan Ding Reviewed-by: Junxiao Bi Cc: Al Viro Cc: Mark Fasheh Cc: Joel Becker Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- fs/ocfs2/file.c | 28 ++++++++++++++-------------- 1 file changed, 14 insertions(+), 14 deletions(-) --- a/fs/ocfs2/file.c +++ b/fs/ocfs2/file.c @@ -2372,6 +2372,20 @@ relock: /* buffered aio wouldn't have proper lock coverage today */ BUG_ON(written == -EIOCBQUEUED && !(iocb->ki_flags & IOCB_DIRECT)); + /* + * deep in g_f_a_w_n()->ocfs2_direct_IO we pass in a ocfs2_dio_end_io + * function pointer which is called when o_direct io completes so that + * it can unlock our rw lock. + * Unfortunately there are error cases which call end_io and others + * that don't. so we don't have to unlock the rw_lock if either an + * async dio is going to do it in the future or an end_io after an + * error has already done it. + */ + if ((written == -EIOCBQUEUED) || (!ocfs2_iocb_is_rw_locked(iocb))) { + rw_level = -1; + unaligned_dio = 0; + } + if (unlikely(written <= 0)) goto no_sync; @@ -2396,20 +2410,6 @@ relock: } no_sync: - /* - * deep in g_f_a_w_n()->ocfs2_direct_IO we pass in a ocfs2_dio_end_io - * function pointer which is called when o_direct io completes so that - * it can unlock our rw lock. - * Unfortunately there are error cases which call end_io and others - * that don't. so we don't have to unlock the rw_lock if either an - * async dio is going to do it in the future or an end_io after an - * error has already done it. - */ - if ((ret == -EIOCBQUEUED) || (!ocfs2_iocb_is_rw_locked(iocb))) { - rw_level = -1; - unaligned_dio = 0; - } - if (unaligned_dio) { ocfs2_iocb_clear_unaligned_aio(iocb); mutex_unlock(&OCFS2_I(inode)->ip_unaligned_aio);