1 files changed, 20 insertions, 8 deletions

diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
index e408bf5a3ff7..bcc7cfabb787 100644
--- a/fs/xfs/xfs_log.c
+++ b/fs/xfs/xfs_log.c
@@ -33,6 +33,7 @@
 #include "xfs_fsops.h"
 #include "xfs_cksum.h"
 #include "xfs_sysfs.h"
+#include "xfs_sb.h"
 
 kmem_zone_t     *xfs_log_ticket_zone;
 
@@ -1290,9 +1291,20 @@ xfs_log_worker(
         struct xfs_mount        *mp = log->l_mp;
 
         /* dgc: errors ignored - not fatal and nowhere to report them */
-        if (xfs_log_need_covered(mp))
-                xfs_fs_log_dummy(mp);
-        else
+        if (xfs_log_need_covered(mp)) {
+                /*
+                 * Dump a transaction into the log that contains no real change.
+                 * This is needed to stamp the current tail LSN into the log
+                 * during the covering operation.
+                 *
+                 * We cannot use an inode here for this - that will push dirty
+                 * state back up into the VFS and then periodic inode flushing
+                 * will prevent log covering from making progress. Hence we
+                 * synchronously log the superblock instead to ensure the
+                 * superblock is immediately unpinned and can be written back.
+                 */
+                xfs_sync_sb(mp, true);
+        } else
                 xfs_log_force(mp, 0);
 
         /* start pushing all the metadata that is currently dirty */
@@ -1395,6 +1407,8 @@ xlog_alloc_log(
         ASSERT(xfs_buf_islocked(bp));
         xfs_buf_unlock(bp);
 
+        /* use high priority wq for log I/O completion */
+        bp->b_ioend_wq = mp->m_log_workqueue;
         bp->b_iodone = xlog_iodone;
         log->l_xbuf = bp;
 
@@ -1427,6 +1441,8 @@ xlog_alloc_log(
                 ASSERT(xfs_buf_islocked(bp));
                 xfs_buf_unlock(bp);
 
+                /* use high priority wq for log I/O completion */
+                bp->b_ioend_wq = mp->m_log_workqueue;
                 bp->b_iodone = xlog_iodone;
                 iclog->ic_bp = bp;
                 iclog->ic_data = bp->b_addr;
@@ -1806,8 +1822,6 @@ xlog_sync(
         XFS_BUF_ZEROFLAGS(bp);
         XFS_BUF_ASYNC(bp);
         bp->b_flags |= XBF_SYNCIO;
-        /* use high priority completion wq */
-        bp->b_ioend_wq = log->l_mp->m_log_workqueue;
 
         if (log->l_mp->m_flags & XFS_MOUNT_BARRIER) {
                 bp->b_flags |= XBF_FUA;
@@ -1856,8 +1870,6 @@ xlog_sync(
                 bp->b_flags |= XBF_SYNCIO;
                 if (log->l_mp->m_flags & XFS_MOUNT_BARRIER)
                         bp->b_flags |= XBF_FUA;
-                /* use high priority completion wq */
-                bp->b_ioend_wq = log->l_mp->m_log_workqueue;
 
                 ASSERT(XFS_BUF_ADDR(bp) <= log->l_logBBsize-1);
                 ASSERT(XFS_BUF_ADDR(bp) + BTOBB(count) <= log->l_logBBsize);
@@ -2027,7 +2039,7 @@ xlog_print_tic_res(
                 "  total reg   = %u bytes (o/flow = %u bytes)\n"
                 "  ophdrs      = %u (ophdr space = %u bytes)\n"
                 "  ophdr + reg = %u bytes\n"
-                "  num regions = %u\n",
+                "  num regions = %u",
                 ((ticket->t_trans_type <= 0 ||
                   ticket->t_trans_type > XFS_TRANS_TYPE_MAX) ?
                   "bad-trans-type" : trans_type_str[ticket->t_trans_type-1]),