JFS: Don't set log_SYNCBARRIER when log->active == 0

If a metadata page is kept active, it is possible that the sync barrier logic
continues to trigger, even if all active transactions have been phyically
written to the journal.  This can cause a hang, since the completion of the
journal I/O is what unsets the sync barrier flag to allow new transactions
to be created.

Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/fs/jfs/jfs_logmgr.c b/fs/jfs/jfs_logmgr.c
index 79d07624bfe..22815e88e7c 100644
--- a/fs/jfs/jfs_logmgr.c
+++ b/fs/jfs/jfs_logmgr.c
@@ -1030,7 +1030,8 @@ static int lmLogSync(struct jfs_log * log, int nosyncwait)
          * starting until all current transactions are completed
          * by setting syncbarrier flag.
          */
-        if (written > LOGSYNC_BARRIER(logsize) && logsize > 32 * LOGPSIZE) {
+        if (!test_bit(log_SYNCBARRIER, &log->flag) &&
+            (written > LOGSYNC_BARRIER(logsize)) && log->active) {
                 set_bit(log_SYNCBARRIER, &log->flag);
                 jfs_info("log barrier on: lsn=0x%x syncpt=0x%x", lsn,
                          log->syncpt);