xfs: external logs need to flush data device

[linux-2.6-microblaze.git] / fs / xfs / xfs_log.c

diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
index 96434cc..a3c4d48 100644 (file)
--- a/fs/xfs/xfs_log.c
+++ b/fs/xfs/xfs_log.c
@@ -827,13 +827,6 @@ 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)
-               blkdev_issue_flush(log->l_mp->m_ddev_targp->bt_bdev);
        return xlog_write(log, &vec, ticket, NULL, NULL, XLOG_UNMOUNT_TRANS);
 }
 
@@ -1796,10 +1789,20 @@ 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)
+                       blkdev_issue_flush(log->l_mp->m_ddev_targp->bt_bdev);
+       }
        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)) {