From: Dave Chinner <dchinner@redhat.com> mainline-inclusion from mainline-v5.14-rc1 commit b5d721eaae47eaa4b4c2754699dadacc4cbca2e0 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I4KIAO CVE: NA Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... ------------------------------------------------- The recent journal flush/FUA changes replaced the flushing of the data device on every iclog write with an up-front async data device cache flush. Unfortunately, the assumption of which this was based on has been proven incorrect by the flush vs log tail update ordering issue. As the fix for that issue uses the XLOG_ICL_NEED_FLUSH flag to indicate that data device needs a cache flush, we now need to (once again) ensure that an iclog write to external logs that need a cache flush to be issued actually issue a cache flush to the data device as well as the log device. Fixes: eef983ffeae7 ("xfs: journal IO cache flush reductions") Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Guo Xuenan <guoxuenan@huawei.com> Reviewed-by: Lihong Kou <koulihong@huawei.com> Reviewed-by: Zhang Yi <yi.zhang@huawei.com> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> --- fs/xfs/xfs_log.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c index fed7a6c3d23e..47ff347418a3 100644 --- a/fs/xfs/xfs_log.c +++ b/fs/xfs/xfs_log.c @@ -800,13 +800,6 @@ xlog_write_unmount_record( /* account for space used by record data */ ticket->t_curr_res -= sizeof(ulf); - /* - * For external log devices, we need to flush the data device cache - * first to ensure all metadata writeback is on stable storage before we - * stamp the tail LSN into the unmount record. - */ - if (log->l_targ != log->l_mp->m_ddev_targp) - xfs_blkdev_issue_flush(log->l_mp->m_ddev_targp); return xlog_write(log, &vec, ticket, NULL, NULL, XLOG_UNMOUNT_TRANS); } @@ -1713,10 +1706,20 @@ xlog_write_iclog( * metadata writeback and causing priority inversions. */ iclog->ic_bio.bi_opf = REQ_OP_WRITE | REQ_META | REQ_SYNC | REQ_IDLE; - if (iclog->ic_flags & XLOG_ICL_NEED_FLUSH) + if (iclog->ic_flags & XLOG_ICL_NEED_FLUSH) { iclog->ic_bio.bi_opf |= REQ_PREFLUSH; + /* + * For external log devices, we also need to flush the data + * device cache first to ensure all metadata writeback covered + * by the LSN in this iclog is on stable storage. This is slow, + * but it *must* complete before we issue the external log IO. + */ + if (log->l_targ != log->l_mp->m_ddev_targp) + xfs_blkdev_issue_flush(log->l_mp->m_ddev_targp); + } if (iclog->ic_flags & XLOG_ICL_NEED_FUA) iclog->ic_bio.bi_opf |= REQ_FUA; + iclog->ic_flags &= ~(XLOG_ICL_NEED_FLUSH | XLOG_ICL_NEED_FUA); if (xlog_map_iclog_data(&iclog->ic_bio, iclog->ic_data, count)) { -- 2.20.1